Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/gcce59613.2023.10315312

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Variable names represent a significant source of information regarding the source code, and a successful naming of variables is key to producing readable code. Programmers often use a compound variable name by concatenating two or more words to make it more informative and enhance the code readability. While each compound variable name is descriptive, a collection of them sometimes produces “confusing” variable pairs if their names are highly similar, e.g., “shippingHeight,” vs. “shippingWeight.” A confusing variable pair would adversely affect the code readability because it can cause a misreading or mix-up of variables during the programming or code review activities. Toward automated support for enhancing code readability, this paper conducts a large-scale investigation of compound variable names in Java and Python programs. The investigation collects 116,921,127 pairs of compound-named variables from 1,876 open-source Java projects and 106,943,523 pairs of such variables from 2,427 open-source Python projects. Then, this study analyzes those variable pairs from two perspectives of name similarity: string similarity and semantic similarity. Through an evaluation study with 30 human participants, the data analyses show that both string and semantic similarity can help detect confusing variable pairs in Java and Python programs. In order to distill confusing variable pairs automatically, support tools for detecting confusing variable pairs are also developed in this study.

DOI： 10.1007/s10664-023-10339-2

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Other Link： https://link.springer.com/article/10.1007/s10664-023-10339-2/fulltext.html

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.cviu.2023.103654

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electronics, Information and Communications Engineers (IEICE)  

DOI： 10.1587/transinf.2022mpl0002

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Publishing type：Research paper (international conference proceedings)  

DOI： 10.1145/3631991.3631996

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Other Link： https://dblp.uni-trier.de/db/conf/wsse/wsse2023.html#IrieAAYK23

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/GCCE59613.2023.10315312

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Other Link： https://dblp.uni-trier.de/db/conf/gcce/gcce2023.html#TanakaYAAA23

Publishing type：Research paper (scientific journal)  

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Other Link： https://dblp.uni-trier.de/db/journals/wipiec/wipiec9.html#AmasakiYA23

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SEAA60479.2023.00054

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2023.html#FushiharaAAYK23

Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1145/3551349.3560505

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SEAA56994.2022.00040

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SEAA56994.2022.00027

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10664-021-10103-4

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Other Link： https://link.springer.com/article/10.1007/s10664-021-10103-4/fulltext.html

Publishing type：Research paper (international conference proceedings)   Publisher：Springer  

DOI： 10.1007/978-3-031-21388-5_30

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Other Link： https://dblp.uni-trier.de/db/conf/profes/profes2022.html#AmasakiAY22

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/IIAIAAI55812.2022.00142

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Other Link： https://dblp.uni-trier.de/db/conf/iiaiaai/iiaiaai2022.html#ToyotaYAAA22

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/asew52652.2021.00036

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/SEAA53835.2021.00042

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2021.html#AmasakiAY21

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

DOI： 10.1007/978-3-030-85347-1_35

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/sera51205.2021.9509042

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Publisher：Cold Spring Harbor Laboratory  

<title>Abstract</title>We developed a novel scotoma detection system using time required for fixation to the random targets, or the” eye-guided scotoma detection method “. In order to verify the” eye-guided scotoma detection method “, we measured 78 eyes of 40 subjects, and examined the measurement results in comparison with the results of measurement by Humphrey perimetry. The results were as follows: (1) Mariotte scotomas were detected in 100% of the eyes tested; (2) The false-negative rate (the percentage of cases where a scotoma was evaluated as a non-scotoma) was less than 10%; (3) The positive point distribution in the low-sensitivity eyes was well matched. These findings suggested that the novel scotoma detection method in the current study will pave the way for the realization of mass screening to detect pathological scotoma earlier.

<sec><title>Author summary</title>Conventional perimeters, such as the Goldmann perimeter and Humphrey perimeter, require experienced examiners and space occupying. With either perimeter, subjects’ eye movements need to be strictly fixed to the fixation target of the device. Other perimeters can monitor fixation and automatically measure the visual field. With the eye-guided scotoma detection method proposed in the current study, subjects feel less burdened since they do not have to fixate on the fixation target of the device and can move their eyes freely. Subjects simply respond to visual targets on the display; then, scotomas can be automatically detected. The novel method yields highly accurate scotoma detection through an algorithm that separates scotomas from non-scotomas.

</sec>

DOI： 10.1101/2021.06.03.21258101

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Authorship：Corresponding author   Language：English   Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

DOI： 10.1007/978-3-030-79474-3_9

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Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

DOI： 10.1007/978-3-030-91452-3_12

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Institute of Applied Informatics  

DOI： 10.52731/iee.v6.i2.529

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/APSEC51365.2020.00029

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Other Link： https://dblp.uni-trier.de/db/conf/apsec/apsec2020.html#AsatoAAYK20

Authorship：Corresponding author   Language：Japanese   Publishing type：Part of collection (book)   Publisher：近代科学社  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：日本ソフトウェア科学会  

DOI： 10.11309/jssst.37.4_38

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ACM  

DOI： 10.1145/3416508.3417118

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Software Science and Technology  

Source code changes are essential for software evolution. However, a source code change also has a risk of introducing a new bug into the software. To predict such a bug by using features of the code change, researchers have studied various bug prediction models in the past. One of the most noteworthy methods is the personalized bug prediction, which builds a prediction model customized for each developer. Although the personalized bug prediction model is a promising one, it also has a challenge that we cannot make appropriate models for less experienced developers due to the lack of code change (commit) data. Toward a resolution of the challenge, this paper proposes a method for combining two or more personalized bug prediction models. The usefulness of the proposed method is proved by an empirical study with the data from five open-source software development projects.

DOI： 10.11309/jssst.37.4_50

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/GCCE50665.2020.9291945

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Other Link： https://dblp.uni-trier.de/db/conf/gcce/gcce2020.html#NaitoYIAAA20

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/SEAA51224.2020.00059

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2020.html#AmasakiAY20

Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/SEAA51224.2020.00023

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2020.html#AmanAYK20

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/smr.2220

Web of Science

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Springer  

DOI： 10.1007/978-3-030-24405-7_5

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Other Link： https://dblp.uni-trier.de/db/conf/bcd/bcd2019s.html#AmanAYK19

Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Part of collection (book)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11309/jssst.36.4_32

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1145/3345629.3345638

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Other Link： https://dblp.uni-trier.de/db/conf/promise/promise2019.html#AmasakiYA19

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/SEAA.2019.00045

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2019.html#AmasakiAY19

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/IIAI-AAI.2019.00100

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Other Link： https://dblp.uni-trier.de/db/conf/iiaiaai/iiaiaai2019.html#MatsumotoYAAA19

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/BCD.2019.8885337

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ACM  

DOI： 10.1145/3319008.3319712

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Other Link： https://dblp.uni-trier.de/db/conf/ease/ease2019.html#AmasakiYA19

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/APSEC.2018.00082

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Other Link： https://dblp.uni-trier.de/db/conf/apsec/apsec2018.html#AmanAYK18

Authorship：Corresponding author   Language：Japanese   Publishing type：Part of collection (book)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Software Science and Technology  

<p>Toward improving readability of source code, this paper proposes a model for judging the compatibility between Java method's name and its implementation, and conducts empirical studies and a survey to examine its usefulness. The proposed method constructs decision trees with many method's data from various source programs, and judges the compatibility between method's name and its implementation. As the results, a validity of model is confirmed and the judging accuracy (F-measure) is about 80%. It is also confirmed that the judgment by the model approximately dovetails with developers' sense.</p>

DOI： 10.11309/jssst.35.115

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1587/transinf.2018EDL8094

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SEAA.2018.00033

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Other Link： https://dblp.uni-trier.de/db/conf/euromicro/euromicro2018.html#TashimaAAYK18

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/COMPSAC.2018.00145

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2991/ijndc.2018.6.3.1

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/BCD2018.2018.00010

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Other Link： https://dblp.uni-trier.de/db/conf/bcd/bcd2018.html#YamauchiAAYK18

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

Machine learning techniques have been actively studied and achieved significant performance improvements in various kinds of tasks. While we benefit from such techniques in many ways, they can be a serious security threat to the Internet if malicious attackers become able to utilize them to discover unknown software vulnerabilities. This paper introduces a new concept of self-evolving botnets, where computing resources of infected hosts are exploited to discover unknown vulnerabilities in non-infected hosts and the botnets evolve autonomously. We provide a stochastic epidemic model for the self-evolving botnets, and show its behaviors through numerical and simulation experiments.

DOI： 10.1016/j.comcom.2018.04.010

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ICSTW.2018.00079

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Authorship：Lead author   Language：English   Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

DOI： 10.1007/978-3-319-69926-4_7

Scopus

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/issrew.2017.37

Web of Science

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

This paper focuses on comments written in source programs. While comments can work for improving the readability of code, i.e., the quality of programs, there have also been concerns thatcomments can be added for complicated source code in order to compensate for a lack of readability. That is to say, well-written comments might be associated with problematic parts to be refactored. This paper collected Java methods (programs) from six popular open source products, and performs analyses on words which appear in their comments. Then, the paper shows that a method having a longer comments (more words)tends to be more change-prone and would be required more fixes after their releases.

DOI： 10.1109/SEAA.2017.23

Scopus

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

Many empirical studies have reported notable theories or methods for evaluating or predicting code quality through analyses of code repositories. This paper has yet another point of view: it focuses on 'commits' rather than source code. That is to say, this paper proposes to evaluate commits themselves. When an aim of a commit is to fix a bug, there can be another preceding commit which made a reason of the bug fixing. Those commits are linked by a bug fixing-based causal relationship. Then, commits can be modeled as a directed graph model of causal relationships. This paper applies Google's PageRank algorithm to the graph modelin order to evaluate commits' influences on the others. Through an empirical study with Git repositories of six open source projects, the following factors are showed to be noteworthy:(1) the number of added files at the commit,(2) the length of commit message,(3) the experience of committing author, and (4) the number of developers who have been involved in the modified files at the commit.

DOI： 10.1109/SEAA.2017.24

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ACIT-CSII-BCD.2017.20

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ACIT-CSII-BCD.2017.44

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ACIT-CSII-BCD.2017.73

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Other Link： https://dblp.uni-trier.de/db/conf/csii/csii2017.html#MiyakeAYA17

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

This paper focuses on differences in comment densities among individual programmers, and proposes to adjust the conventional code complexity metric (the cyclomatic complexity) by using the abnormality of the comment density. An empirical study with nine popular open source Java products (including 103,246 methods) shows that the proposed metric performs better than the conventional one in predicting change-prone methods; the proposed metric improves the area under the ROC curve (AUC) by about 3.4% on average.

DOI： 10.1587/transinf.2016EDL8224

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Open source software (OSS) products have been broadly utilized for the IT business as well as the personal use in recent years. Software companies can receive much benefit from OSS products in terms of cost to develop and maintain their products. However, there are also risks that products of interest might become no longer being successfully maintained by the OSS developers because a successful maintenance is not obligation of developers. In order to evaluate a project's health from a perspective of a macroscopic trend analysis, this paper focuses on the distribution of the developer's contribution to an OSS project, and analyzes the relationships of distribution features with the quality of products. The empirical analysis with 32 popular OSS projects shows that the length of tail in the Pareto chart can be a health index of an OSS project in terms of the balance between bug fix and feature upgrade.

DOI： 10.1109/IWESEP.2017.14

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPRINGER INTERNATIONAL PUBLISHING AG  

Context: Recent studies empirically revealed a relationship between source code comments and code quality. Some studies showed well-written source code comments could be a sign of problematic methods. Other studies also show that source code files with comments confessing a technical debt (called self-admitted technical debt, SATD) could be fixed more times. The former studies only considered the amount of comments, and their findings might be due to a specific type of comments, namely, SATD comments used in the latter studies. Objective: To clarify the relationship between comments other than SATD comments and code quality. Method: Replicate a part of the latter studies with such comments of methods on four OSS projects. Results: At both the file-level and the method-level, the presence of comments could be related to more code fixings even if the comments were not SATD comments. However, SATD comments were more effective to spot fix-prone files and methods than the non-SATD comments. Conclusions: Source code comments other than SATD comments could still be a sign of problematic code. This study demonstrates a need for further analysis on the contents of comments and its relation to code quality.

DOI： 10.1007/978-3-319-51472-7_2

Web of Science

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Atlantis Press  

DOI： 10.2991/ijndc.2017.5.4.3

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

This paper focuses on the content of test cases, and categorizes test cases into clusters using the similarity between test cases; their degree of similarity is obtained through a morphological analysis. If there are two similar test cases, they would test the same or similar functionalities in similar but different conditions. Thus, when one of them is run for a regression testing, the remaining one should be run as well, in order to reduce a risk of overlooking regressions. Once a test engineer decides to run a set of test cases, the method proposed in this paper can recommend adding similar test cases to their candidate set. The proposed method also considers the priorities of recommended test cases by using the Mahalanobis-Taguchi method. This paper reports on an empirical study with an industrial software product. The results show that the proposed method is useful to prevent overlooking regressions.

DOI： 10.1109/ICSTW.2017.9

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Code review is an essential activity to ensure the quality of code being developed, and there have been static code checkers for aiding an effective code review. However, such tools have not been actively utilized in the world of programmers due to a lot of coding violations (warning) produced by tools and their false-positiveness. In order to analyze the automatically pointed violations and the actual attentions which programmers paid to those violations, this paper proposes a novel metric-the Index of Programmers' Attention (IPA)-and conducts an empirical study focusing on the change patterns of violations over the releases of popular seven open source software products, under two research questions (RQs): (RQ1) What kind of coding violations are related to the parts that many programmers tend to improve? and what kind of coding violations are likely to be disregarded?; (RQ2) How can we reduce the meaningless violations for programmers by omitting disregarded coding violations?
The empirical results showed the following findings: (1) important violations (having high IPA values) may vary from project to project; (2) there are some unimportant violations common to different projects, but they are a minority of automatically detected violations (about 12%). Therefore, while many violations may be made by a code checker, most of them are likely to be worthy in improving the code quality, and it is ineffective to reduce the violations by eliminating such unimportant violations.

DOI： 10.1109/APSEC.2016.29

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：CEUR-WS.org  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

The railway signaling system plays an important role to achieve the safety and the reliability. The income of the railway company is assumed to decrease by the low birthrate and aging. So the railway company is required a reduction of life cycle cost of equipment. In this paper, we propose a new life cycle cost model that considered “the economic loss cost of the passengers who have encountered with the equipment fault” in a life cycle cost model. And we performed various case studies that considered economic loss cost, and confirmed that reduction of the life cycle cost was possible.

DOI： 10.14923/transinfj.2015JDP7085

CiNii Research

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Machine learning techniques have been achieving significant performance improvements in various kinds of tasks, and they are getting applied in many research fields. While we benefit from such techniques in many ways, they can be a serious security threat to the Internet if malicious attackers become able to utilize them to detect software vulnerabilities. This paper introduces a new concept of self-evolving botnets, where computing resources of infected hosts are exploited to discover unknown vulnerabilities in non-infected hosts. We propose a stochastic epidemic model that incorporates such a feature of botnets, and show its behaviors through numerical experiments and simulations.

DOI： 10.1109/CITS.2016.7546428

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE COMPUTER SOC  

To enhance the cost effectiveness of regression testing, this paper proposes a method for prioritizing test cases. In general, a test case can be evaluated from various different points of view, therefore whether it is worth it to re-run should be discussed using multi criteria. This paper shows that the Mahalanobis-Taguchi (MT) method is a useful way to successfully integrate different evaluations of a test case. Moreover, this paper proposes to use the 0-1 programming method together with the MT method in order to take into account not only the priority of a test case but also its cost to run. The empirical study with 300 test cases for an industrial software system shows that the combination of the MT method and the 0-1 programming method is more cost-effective than other conventional methods.

DOI： 10.1109/SEAA.2016.29

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

This paper focuses on the power of comments to predict fault-prone programs. In general, comments along with executable statements enhance the understandability of programs. However, comments may also be used to mask the lack of readability in the program, therefore well-written comments are referred to as "deodorant to mask code smells" in the field of code refactoring. This paper conducts an empirical analysis to examine whether Lines of Comments (LCM) written inside a method's body is a noteworthy metric for analyzing fault-proneness in Java methods. The empirical results show the following two findings: (1) more-commented methods (the methods having more comments than the amount estimated by size and complexity of the methods) are about 1.6 - 2.8 times more likely to be faulty than the others, and (2) LCM can be a useful factor in fault-prone method prediction models along with the method size and the method complexity.

DOI： 10.1587/transinf.2015EDP7107

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Computer Society  

This paper focuses on the local variable names and comments that are major artifacts reflecting the programmer's preference. It conducts an empirical analysis on the usefulness of those artifacts in assessing the software quality from the perspective of change-proneness in Java methods developed in six popular open source software products. The empirical results show: (1) a method having a longer named local variable is more change-prone, and (2) the presence of comments inside the method body strengthens the suspicions to be modified after the release. The above artifacts are worthy to find methods which can survive unscathed after the release.

DOI： 10.1109/ESEM.2015.7321197

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Software Science and Technology  

It is ideal to test whether there is a regression in a software system or not by running all available test cases, whenever the system is modified. However, practitioners may not be able to run all test cases due to a lack of time or manpower, and then they usually prioritize the test cases and run some of them in decreasing order of priority. In order to make such regression testings more cost-effective, an application of 0&ndash;1 programming method to plan the regression testing has been studied in the past. While an empirical superiority of the 0&ndash;1 programming method-based testing over the conventional one has been reported, there is an issue of the testing completeness such that only a few functionalities might be tested. Thus, this paper utilizes a clustering technique for a more effective test case selection and proposes to formulate the regression testing as a 0&ndash;1 programming problem having constraints to cover all clusters of the test cases. The empirical work shows that the proposed method can detect regressions with about one-third (1/3) effort of the conventional method.

DOI： 10.11309/jssst.32.3_111

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：情報処理学会  

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Information Processing Society of Japan (IPSJ)  

This paper proposes a bug triaging method to reduce the time to fix bugs in large-scale open source software development. Our method considers the upper limit of tasks which can be fixed by a developer in a certain period. In this paper, we conduct a case study of applying our method to Mozilla Firefox and Eclipse Platform projects and show the following findings: (1) using our method mitigates the situation where the majority of bug-fixing tasks are assigned to particular developers, (2) our method can reduce up to 50%-83% of time to fix bugs compared with the manual bug triaging method and up to 34%-38% compared with the existing method, and (3) the two factors, Preference (adequate for fixing a bug) and Limit (limits of developers' working hours), used in our method have an dispersion effect on the task assignment.

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

This paper focuses on the local variable names and comments that are major artifacts reflecting the programmer's preference. It conducts an empirical analysis on the usefulness of those artifacts in assessing the software quality from the perspective of change-proneness in Java methods developed in six popular open source software products. The empirical results show: (1) a method having a longer named local variable is more change-prone, and (2) the presence of comments inside the method body strengthens the suspicions to be modified after the release. The above artifacts are worthy to find methods which can survive unscathed after the release.

DOI： 10.1109/ESEM.2015.7321197

Web of Science

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

J-GLOBAL

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11348/reajshinrai.36.8_501

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Reliability Engineering Association of Japan (REAJ)  

With shrinking of LSIs, the diversification of defective mode becomes a critical issue. N-detection tests have been known as an effective way for achieving high defect coverage, however the large number of test pattern counts is the problem. In this paper, we propose metrics(defect detection probability) based on the fault excitation functions to evaluate test patterns for transition faults. We also formulate the method for selecting the test patterns from the N-detection test set based on the defect detection probability as a 0-1 integer linear program. From the experimental results, we show that the set of selected test patterns can detect the larger number of fault models than the given test set with the same number of test patterns.

DOI： 10.11348/reajshinrai.36.8_501

CiNii Books

J-GLOBAL

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Publisher：IEEE  

DOI： 10.1109/APSEC.2014.93

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Publisher：ACM  

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Other Link： http://dblp.uni-trier.de/db/conf/esem/esem2014.html#conf/esem/AmanSAK14

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

In recent years, many open source software (OSS) products have become popular and widely used in the information technology (IT) business. To successfully run IT business, it is important to properly understand the OSS development status. Having a proper understanding of development status is necessary to evaluate and predict the product quality. However, the OSS development status is not easy to understand, because it is often concurrently developed by many distributed contributors, and its developmental structure is complicated. To aid the understanding of the development status, there is an approach that models the trend of source code change events (evolution) with a growth curve. Although an application of growth curves seems to be a promising approach, there has been a big issue that a single growth curve is often unsuitable for modeling the whole evolution because of its complex evolutionary behavior. This paper proposes a multistage model that divides the whole development period into some stages, and applies a different growth curve to a different stage. The empirical investigation in this paper shows that the switching points of stages have meaningful associations with the release dates.

DOI： 10.1109/SEAA.2014.47

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

This paper reports an application of the 0-1 programming model to the regression testing plan for an industrial software. The key idea is to formulate a testing plan as a 0-1 programming problem (Knapsack problem). The empirical study shows that the 0-1 programming method can produce a cost-effective testing plan in which all potential regressions are found at only 22% of the cost of running all test cases.

DOI： 10.1109/COMPSAC.2013.116

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE COMPUTER SOC  

Code review is a powerful activity for software quality improvement, and is ideal to review all source files being developed. However, such an exhaustive review would be difficult because the available time and effort are in reality limited. Thus, practitioners prioritize the source files in terms of bug-proneness by using related data such as bug fix history, and review them in decreasing order of priority-such strategy in this paper is called the "conventional method." While the conventional method is straightforward, it focuses only on the bug-proneness and cannot consider the review cost properly, so the method does not produce a cost-effective review plan. To take into account both the bug-proneness and the review cost, this paper proposes a 0-1 programming model-based method for planning code review. The proposed method formulates a review plan as a 0-1 programming problem, and the solution is the recommendation list of source files to be reviewed. Moreover, the proposed method considers the type of file-if the file is newly-developed or not. Such difference in file type may affect on how to evaluate the bug-proneness and the review strategy: newly-developed files are notable but not appeared in the bug fix history. This paper conducts a case study using popular open source software, shows that the proposed method is up to 42% more effective than the conventional method in recommending buggy files as the review targets.

DOI： 10.1109/APSEC.2013.109

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Code clones are duplicated or similar code fragments, and they have been known as major entities affecting the software maintain-ability. Sometimes there are "co-changes" in pair of code clones: when a code fragment is changed, the clone of the fragment is also changed. Such a co-change is one of key event to discuss the successful management of code clone. This paper analyzes the trends of co-changed code clones by using the length and the content of code clones. The empirical results show that: (1) there would be a specific length of clone to be mostly co-changed (around 60 - 100 tokens), and (2) code clones without any "control flow keywords" have a higher possibility to be co-changed than the others.

DOI： 10.1587/transfun.E95.A.1498

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Language：Japanese  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11309/jssst.29.3_115

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE COMPUTER SOC  

Code size metrics are commonly useful in predicting fault-prone modules, and the larger module tends to be more faulty. In other words, small-size modules are considered to have lower risks of fault. However, since the majority of modules in a software are often small-size, many "small but faulty" modules have been found in the real world. Hence, another fault-prone module prediction method, intended for small-size module, is also required. Such a new method for small-size module should use metrics other than code size since all modules are small size. This paper focuses on "comments" written in the source code from a novel perspective of size-independent metrics; comments have not been drawn much attention in the field of fault-prone module prediction. The empirical study collects 11, 512 small-size modules, whose LOC are less than the median, from three major open source software, and analyzes the relationship between the lines of comments and the fault-proneness in the set of small-size modules. The empirical results show the followings: 1) A module in which some comments are written is more likely to be faulty than non-commented ones; the fault rate of commented modules is about 1.8 - 3.5 times higher than that of non-commented ones. 2) Writing one to four lines of comments would be thresholds of the above tendency.

DOI： 10.1109/APSEC.2012.108

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Language：English   Publishing type：Research paper (international conference proceedings)  

Comment statements are useful to enhance the readability and/or understandability of software modules. However, some comments may adjust the readability/understandability of code fragments that are too complicated and hard to understand - a kind of code smell. Consequently, some well-written comments may be signs of poor-quality modules. This paper focuses on the lines of comments written in modules, and performs an empirical analysis with three major open source software and their fault data. The empirical results show that the risk of being faulty in well-commented modules is about 2 to 8 times greater than non-commented modules. © 2012 IEEE.

DOI： 10.1109/IWESEP.2012.12

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electronics, Information and Communication, Engineers, IEICE  

Code clones are duplicated or similar code fragments, and they have been known as major entities affecting the software maintainability. Sometimes there are "co-changes" in pair of code clones: when a code fragment is changed, the clone of the fragment is also changed. Such a co-change is one of key event to discuss the successful management of code clone. This paper analyzes the trends of co-changed code clones by using the length and the content of code clones. The empirical results show that: (1) there would be a specific length of clone to be mostly co-changed (around 60-100 tokens), and (2) code clones without any "control flow keywords" have a higher possibility to be co-changed than the others. Copyright © 2012 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transfun.E95.A.1498

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Software Science and Technology  

Utilization of software metrics is essential to successful software quality management. However, software metrics are sometimes misused, abandoned or unconsidered in practice. To avoid these unwanted consequences, we need to answer the simple but difficult problem about "what to measure and how to utilize." This article discusses fundamental topics which include classification of metrics, measurement theory, statistical models and their pitfalls. The article also provide some useful information about tools which help us make use of software metrics.

DOI： 10.11309/jssst.28.3_12

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Other Link： https://jlc.jst.go.jp/DN/JALC/00377977134?from=CiNii

Language：English   Publishing type：Research paper (international conference proceedings)  

This paper proposes a novel method for predicting the amount of source code changes (changed lines of code: changed-LOC) in the open source development (OSD). While the software evolution can be observed through the public code repository in OSD, it is not easy to understand and predict the state of the whole development because of the huge amount of less-organized information. The method proposed in the paper predicts the code changes by using only data freely available from the code repository-the code-change time stamp and the changed-LOC. The method consists of two steps: 1) to predict the number of occurrences of code changes by using a nonhomogeneous Poisson process (NHPP)-based model, and 2) to predict the amount of code changes by using the outcome of the step-1 and the previously changed-LOC. The empirical work shows that the proposed method has an ability to predict the changed-LOC in the next 12 months with less than 10% error. © 2011 IEEE.

DOI： 10.1109/IWSM-MENSURA.2011.16

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11309/jssst.27.4_240

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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J-GLOBAL

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I O S PRESS  

Comment statements written in a source code are important information to understand and to maintain the source code. This paper performs an empirical study of impacts of comment statements on source code stability in an open source development. The study collected 4, 521 source code and their version-upgrade data from a major open source software project, Eclipse. The empirical results show the following findings: (1) a source code with a high comment-density (about more than 40%) has a tendency to be stable through the upgrdes, but (2) a source code with frequently-written comments has the opposite tendency. This work thus concludes that describing many comments is recommend for developing a stable code, but frequently describing comments is discouraged.

DOI： 10.3233/978-1-58603-900-4-415

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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CiNii Research

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

In software development, comprehensive software reviews and testings are important activities to preserve high quality and to control maintenance cost. However it would be actually difficult to perform comprehensive software reviews and testings because of a lot of components, a lack of manpower and other realistic restrictions. To improve performances of reviews and testings in object-oriented software, this paper proposes a novel model for detecting cost-prone classes; the model is based on Mahalanobis-Taguchi method-an extended statistical discriminant method merging with a pattern recognition approach. Experimental results using a lot of Java software are provided to statistically demonstrate that the proposed model has a high ability for detecting cost-prone classes.

DOI： 10.1093/ietisy/e89-d.4.1347

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

In software development, comprehensive software reviews and testings are important activities to preserve high quality and to control maintenance cost. However it would be actually difficult to perform comprehensive software reviews and testings because of a lot of components, a lack of manpower and other realistic restrictions. To improve performances of reviews and testings in object-oriented software, this paper proposes a novel model for detecting cost-prone classes; the model is based on Mahalanobis-Taguchi method-an extended statistical discriminant method merging with a pattern recognition approach. Experimental results using a lot of Java software are provided to statistically demonstrate that the proposed model has a high ability for detecting cost-prone classes.

DOI： 10.1093/ietisy/e89-d.4.1347

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I O S PRESS  

This paper focuses on the density of comment statements in a source code, and statistically analyzes an impact of the comment statement density (CSD) on the source code change rate (SCR) through a corrective maintenance. More thorough writing of comments encourages the developers to review their source code more carefully, then that leads to quality improvements of those code. An empirical study is performed with 1, 820 version-upgrade cases in In open-source software, Eclipse. The empirical results show that SCR tends to increase when CSD is less than 59.5%.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

SAS-2 is an alternative of a one-time password authentication protocol SAS, and is developed in order to reduce overhead due to the use of hash functions. The idea of both algorithms is sharing a similar secret number called the verifier that allows a client to be authenticated and that is changed for each new session. However, some of the combinations proposed in [1] to transmit the verifier may contain a security flaw, and the insecure combination results in vulnerability to impersonation attacks.

DOI： 10.1093/ietcom/e88-b.10.4081

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Larger object classes often become more costly classes in the maintenance phase of object-oriented software. Consequently class would have to be constructed in a medium or small size. In order to discuss such desirable size, this paper proposes a simple method for predictively discriminating costly classes in version-upgrades, using a class size metric, Stmts. Concretely, a threshold value of class size (in Struts) is provided through empirical studies using many Java classes. The threshold value succeeded as a predictive discriminator for about 73% of the sample Java classes.

DOI： 10.1093/ietisy/e88-d.6.1284

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Cohesion is an important software attribute, and it is one of significant criteria for assessing object-oriented software quality. Although several metrics for measuring cohesion have been proposed, there is an aspect which has not been supported by those existing metrics, that is "cohesive-part size." This paper proposes a new metric focusing on "cohesive-part size," and evaluates it in both of qualitative and quantitative ways, with a mathematical framework and an experiment measuring some Java classes, respectively. Through those evaluations, the proposed metric is showed to be a reasonable metric, and not redundant one. It can collaborate with other existing metrics in measuring class cohesion, and will contribute to more accurate measurement.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I O S PRESS  

Larger classes often become more costly classes in the maintenance phase. So class would have to be construct in a medium or small size. In order to discuss such desirable size, this paper proposes a method for predictively discriminating costly classes in version-upgrades, using a class size metric, Stmts. Concretely, a threshold value of class size (in Struts) is provided through empirical studies using many Java classes. The threshold value succeeded as a predictive discriminator for ca.73% of the sample Java classes.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Fuzzy Theory and Intelligent Informatics  

In object-oriented software development, class design is one of the most significant factors. In order to provide assessments or predictions of class designs, software metrics have been studied in software engineering discipline. When a software metric does not give a reasonable evaluation to a class, we could modify the class structure, and our modification could lead to simplify the class design quality. In order to support such modifications in terms of class structural complexity, an analysis-method with fuzzy graph has been proposed in the past. This is a method for detecting a class member -a method or an attribute- such that it may have a significant impact on the class structural complexity. However, the method effectiveness has never been discussed. The contribution of this paper is to present an empirical study on the effectiveness of that method. In the empirical study, many object-oriented programs (Java classes) are made pseudo modifications, and impacts of those modifications are evaluated by a software metric. The empirical results show that the class members corresponding to the strengthen points in terms of unilaterally connected graph or strongly connected graph could have significant impacts on the class structural complexity. Thus, the above method is useful for class structural analysis.

DOI： 10.3156/jsoft.15.243

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Properly representation of the complexity of class structure will be useful in object oriented software developments. Although some class complexity metrics have been proposed, they have ignored directions of coupling relationships among methods and attributes. such as whether a method writes data onto an attribute or reads data from the attribute. In this paper, we use a directed graph model to represent such coupling relationships Based on the directed graph model, we proposed a metric of class structural complexity. The proposed metric satisfies necessary conditions of complexity metric suggusted by Briand and others, The following fact is showed by experimental data of Java classes. While the proposed metric follows a conventional metric, the proposed metric can capture an aspect of class structural complexity which is lost by the conventional one.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Properly representation of the complexity of class structure will be useful in object oriented software developments. Although some class complexity metrics have been proposed, they have ignored directions of coupling relationships among methods and attributes, such as whether a method writes data onto an attribute or reads data from the attribute. In this paper, we use a directed graph model to represent such coupling relationships. Based on the directed graph model, we propose a metric of class structural complexity. The proposed metric satisfies necessary conditions of complexity metric suggested by Briand and others. The following fact is showed by experimental data of Java classes. While the proposed metric follows a conventional metric, the proposed metric can capture an aspect of class structural complexity which is lost by the conventional one.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I O S PRESS  

Cohesion is one of traditional and important software attributes. This could be used to assess object-oriented class design. Several metrics have been proposed in order to capture class cohesion in terms of connections among methods within a class. These metrics are based on (1) the number of sets of connected methods, or (2) the density of method connections within the class, but they do not consider sizes of sets of connected methods. In this paper, two new metrics for class cohesion have been proposed, which are focusing on sizes of sets of connected methods, with considering strength of method connection. These proposed metrics are analytically verified using a mathematical framework.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Biomedical Fuzzy Systems Association  

The satisfiability problem(SAT)of the propositional calculus is one of the most basic and important problems in the computer science. On the other hand the SAT is a famous NP-complete problem. It requires a lot of time to solve in general as the problem size becomes large. We proposed a recurrent analog neural network called LPPH for the SAT. The basic dynamics of the LPPH have the following properties: 1)every equilibrium point of the dynamics is a solution of the analog version of the SAT, called CONSAT, and vice versa, and 2)almost all equilibrium points have some kind of asymptotical stability. Experimental results show that the LPPH can solve the SAT effectively even if it is executed by numerical simulations on conventional computers. In this paper we introduce coefficients called "coefficients of attention" to the dynamics the LPPH and show that the performance of the LPPH for solving the SAT is improved.

DOI： 10.24466/ijbschs.5.2_65

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I O S PRESS  

We represent a class structure as a directed graph which is called class structure graph, and quantify the dependent relationships among class members using the class structure graph. Then we propose a measurement of a class structural complexity attribute so as to be more flexible and more suitable for OO software rather than we previously proposed measurement.

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3156/jfuzzy.11.3_163

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

As a simplified analogy of the function that the real neurons and synapses do by chemical particles, a new type of neuron model is proposed including its simulated synaptic function where the symbolized particles are generated, emitted, stored and transmitted toward the neurons of the next layer. The several kinds of chemical particles have been discovered on the recent scientific knowledge. The simulated system of the model was applied to the analysis of voice signals, and obtained useful results such that even with a single neuron including the unit simulated synapse, the examined voices demonstrated a high degree of recognition. The reaction mechanism in simulated synaptic region would be shown by some strategy.

Scopus

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

In this paper, we represent a class structure using directed graph in which each node corresponds to each member of the class. To quantify the dependence relationship among members. we define weighted closure. Using this quantified relationship and effort equation proposed by M.H.Halstead, we propose a metric for class structural complexity.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：Biomedical Fuzzy Systems Association  

In decision making problem, it is natural to decide the problem including person's nature besides basic method such as AHP (Analytic Hierarchy Process ). The person's nature is expressed by a vector defined on n - dimensional space. The vector is classified into several categories related with the selection of the best alternative. The categories are mapped onto two - dimensional plane by a pair of the vectors defined on n - dimensional space. Thus we can visually analyze the character of categories, i.e. the person's nature, by the computer simulation.

DOI： 10.24466/pacbfsa.8.0_33

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Language：Japanese   Book type：Textbook, survey, introduction

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：Japan Society for Software Science and Technology  

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Language：Japanese  

CiNii Books

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CiNii Books

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CiNii Books

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CiNii Books

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CiNii Books

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Language：Japanese   Publisher：Japan Society for Software Science and Technology  

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Language：Japanese   Publisher：一般社団法人情報処理学会  

本稿は静的解析ツールで検出可能なコーディング規約違反に着目し，実際のオープンソース開発においてどういった規約違反が多く検出され，その中でどういった規約違反は結果的に解消されていくのか，あるいは逆に解消されずにそのまま残っていくのかを調査している．調査としては，Java 言語で開発されている 2 種類のオープンソースソフトウェアに対して，それらのリポジトリへのコミットごとに静的解析ツール Checkstyle を適用し，Sun Java コーディング規約に対する違反情報を収集している．分析の結果，二つのソフトウェアにおいて六つの違反項目が共通して多く検出されることが分かり，それらの変化 （改善） の傾向から開発の過程でプログラマがどういった点に注意を払っていたかを考察している．

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Recently, there has been research on planning cost-effective code reviews, based on software metrics and mathematical programming models. Those methods select software modules, which should be reviewed carefully, from many modules under development. In the real world, however, there are many less fault-prone modules that are very simple and/or very small sized. Then, there is a question about whether such less fault-prone modules should be included in the candidate set of modules to be carefully reviewed. This paper focuses on this question, and proposes a filtering method that filters less fault-prone modules out from the candidate set, based on software metrics. The paper performs empirical study using three major open source software, and discusses the usefulness of proposed filtering method.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

While comments are useful in enhancing the program readability, some comments would be used for covering up complicated code fragments. Thus, code fragments with comments would be suspected to have potential faults. This paper focuses on small-sized programs, which do not need many comments because of their smallness, and surveyed 20 major open source software to analyze the relationship between the lines of comments and the fault-proneness. The survey results shows that small-sized programs, which have comments in their methods, tend to have about two times higher risk of potential faults than non-commented ones.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Comment statements are useful elements for enhancing the readability of program. However, sometimes comments are used to adjust lacks of readability of complicated code fragments, so many comments are not always recommended. Actually, there have been some reports saying that the program having more comments are more fault-prone. This paper focuses on the change in the amount of comments thorough version upgrades, and performs an empirical analysis of fault-proneness in the source files whose comments are growing, using four major open source software. The empirical results showed that the source files whose comments are strongly growing are about double fault-prone than the others.

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Language：Japanese   Publisher：一般社団法人情報処理学会  

ソフトウェア開発における不具合埋め込み件数は、規模だけでなく、開発プロジェクト毎の特徴により影響があると考えられる。本論文では、V字型モデルのソフトウェア開発プロセスにおける下流工程(ソフトウェア詳細設計、コード作成を対象)での工程別の欠陥埋め込み件数の予測を行う手法を提案する。

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Generally, software evolutions including quality improvements and feature developments are undergone through the source code changes. Code changes are categorized into two types, primary changes and secondary changes: a primary change is a code change directly caused by bug fix and/or feature change; a secondary change is a code change caused by other changes including a primary change or another secondary change. Controlling secondary changes can be effective in order to control amount of code changes, i.e. patch sizes. This paper investigates the incidence rate and the change behaviour during upgrades in actual open source software. Moreover, this paper focuses on code relationships based on dependencies or code clones as the major factors of secondary changes. For each factor, the incidence trends are analyzed using the survival analysis. The empirical results show the followings: (1) the incidence rate of secondary change is about 38% in all changes; (2) the incidence rate of secondary change caused by dependency relation is about 17.3%, and the rate by code clone relation is about 25.6%; (3) some of the secondary changes caused by dependency relation would occur later (within 150 days; 5.1%). On the other hands, most of the secondary changes by code clone relation occur simultaneously.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper considers a source code change in the open source development to be a stochastic event, and proposes to model the occurrence of code change events based on the non-homogeneous Poisson process(NHPP). Then the paper develops a novel method for predicting the number of code change events and the amount of code changes (changed LOC) using NHPP. The empirical study using an actual open source development shows that the proposed method has an ability to predict the code change of the next 12 months with less than about 10% error in the latter period of development.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In consecutive upgrades of a source code, some upgrade spots (code fragments) are overlapped : that is, "chain of code changes." Such chain would have a potential to make the development unstable. This paper investigates chain of code changes in an actual open source software. The empirical results show the followings : (1) chain's occarrence rate is about 10% in average ; the rate becomes higher within a few days after a upgrade or around 40 days after a upgrade. (2) "code-addition" s would occur more change chains in their following versions.

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Comments written in a source code would be useful for understanding the code. However, some comments mask problematic code which is complex and/or hard-to-understand. In the study of refactoring, such problematic code is called "bad smell" and the associated comments serve as "air freshener." To investigate such impact of comments, this paper collects a lot of source code from one of famous open source software, Eclipse, and performs a quantitative analysis on the code. The empirical results show the followings: (1) A code having more comments would be more fault-prone; (2) A code including a comment-out would be more fault-prone; (3) Neither above trends (1) nor (2) would be observed in a smaller code (less than 60 LOG).

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In an open source software development, a source code is a basic product reflecting the software developmental status. Modeling and predicting the code churn would play a key role in the quantitative quality-management activities for the open source software. This paper introduces a growth curve model for predicting code churn, and performs a trial empirical work to predict code churn in 15 packages included in two open source software, jEdit and PMD. The empirical results shows that the trial model would have a high-ability for predicting code churn in the next three months with less than almost 10% and in the next 12 months with less than almost 25%.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Detecting fault-prone modules have been widely studied in the field of software metrics. While all fault-prone modules should be carefully reviewed, it would be hard to perform the complete review because of a limited budget. This paper proposes an integer programming approach for performing an effective review based on software metrics. A case study with 9,510 modules shows that the proposed approach could be more effective in selecting modules to be carefully reviewed.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Source code is a basic product reflecting a status of an open source development. A quantitative understanding of source code churn trends will be important to make an assessment and/or a prediction about the software quality and the development project. Toward the achievement of the quantitative understanding, this paper studies some mathematical models in which a code change is considered to be a probability event-the mathematical models are the exponential growth model, the delayed S-shaped growth model and the inflection S-shaped growth model, that are based on the non-homogeneous Poisson process. The empirical study using Eclipse source code shows that the inflection S-shaped growth model has been well fitted to actual code churn trends, but some important future work have been found out as well.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper focuses on the distribution of code-addition and code-modification in open source software, and performs an empirical study on a relationship between the distribution and the code maintainability. Especially it focuses on Pareto principle such that most of code changes are occurred in some source files. The empirical analysis is performed on three medium-scale open source software that are developed and/or maintained over six years. The empirical results show that the degree of obeying Pareto principle in a project is empirically related to the maintainability of the project's products.

CiNii Books

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Language：Japanese  

CiNii Books

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Other Link： http://id.nii.ac.jp/1001/00062217/

Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper focuses on a growth curve model-based method for estimating the total number of bugs in open source development. It is better to construct a precious model with bug data at an earlier stage, i.e., shorter period of collecting bug data. However it has not been known how long the period is required for constructing a precious estimating model. In order to determine an appropriate period, this paper proposes an application of the control chart, one of major statistical quality control methods, to construction of the estimating model. The empirical study performs the data collections and model constructions for two large-scale open source development projects that have been maintained over eight years. The empirical results show a precious model would be constructed with bug data collected for the period in which there are less than or equal to 10% outliers-bug reports beyonding the control limits.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper focuses on bug reports in open source developments, and discusses about abilities for modeling and predicting amount of bug reports, using growth curve models. The empirical study performs a data collection of 2,997 bug reports from three versions of Apache Tomcat (Tomcat 3, 4 and 5), and shows that Weibull curve model, a flexible growth curve model, could be used for modeling changes in cumulative bug reports. Moreover the paper focuses on differences in severities of bugs and differences in the software versions as well. Through the data analyzes, the results give the following findings: (1) differences in severities have no impact on the forms of growth curves; (2) differences in the software versions have some impacts on the growth curves-the initial version has an exponential curve but the later versions have S-shaped curves.

CiNii Books

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

CiNii Books

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Other Link： http://id.nii.ac.jp/1001/00021040/

Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper explores date and size of source code upgrades in open source software development, and considers mathematical models for predicting source code stability using a lot of statistical data on the above code upgrades. The preliminary empirical study in this paper collects 5959 version-upgrade data from three large-scale open source software, and constructs the mathematical models using Gompertz curve for representing (1) amount of code changes, (2) lines of code (LOC), and (3) method counts. The empirical results show that each model for (1), (2) and (3) could fit their real values within 10% errors, and those models would be useful in data predictions when those models are constructed using code upgrade data accumulated for 500〜1700 days.

CiNii Books

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

CiNii Books

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Other Link： http://id.nii.ac.jp/1001/00060959/

Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

J-GLOBAL

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper studies distributions of source code changes in open source development, based on the Pareto principle. The empirical study sets up a hypothesis "the majority of changes to source code are made in a small number of source files," and attempts to verify the hypothesis using 9,103 upgrade data that from two large-scale open source software. The empirical results show that 80% and 90% of code changes are made in about 10〜14% of their source files. Moreover, this paper discusses a steady-state analysis for the development projects by observing the ratios of source files according to the above 80%/90% of code changes.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Requirements acquisition process is the first stage in a software development process that has significant impacts on the following stages. While this process is very important, software developers have inadequate thchnical supports. This paper focuses on a requests list presented by customers. We consider about a requests model, which is constructed from a requests lists, for supporting requirements acquisition. Then, we propose a method for extracting important requests from the model.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In some cases, the same numerical/string literals have several appearances in a source file. Those literals are called "magic numbers" in the field of software refactoring, and such the same literals should be replaced by a single constant, that is called "symbolic constant." Indeed some utilities and/or plug-ins are developed for refactoring magic numbers into symbolic constants. However the refactoring is restricted within a source file-if some magic numbers appeared in two or more source files, the corresponding symbolic constants are independently created in each of the files. This paper develops a new support tool "CONSTRec" for maintaining symbolic constants declared in different files. The empirical study examines CONSTRec using three major open source software.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper focuses on a stability of source code in open source software developments, and performs a fundamental data collection and analysis. In the empirical study, 2,593 version-upgrade data of 723 Java source files are collected from the repository of Apache Tomcat 5.0.0〜 5.0.30, then intervals of upgrade, changes in source code line and changes in design specification are discussed. The empirical results show a potential for which a change in design specification would have a large impact on the code stability.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In source code maintenance actiities, some code fragments have been changed continuously for some version upgrades. Such continuous changes form a "chain" of change. This paper focuses on an impact of change-chain onto a source code stability, and performs an empirical study with an open source development project, Eclipse. The empirical results show the followings: (1) a termination of change-chain in a source code enhances the code stability; (2) a short change-chain makes a code more stable; (3) about 18% of change chains would be continued to the next version upgrade.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Requirements acquisition process is the first stage in a software development process that has significant impacts on the following stage. While this process is very important, software developers have inadequate thchnical support. This paper focuses on a requirements list presented by the customer. We propose about a method for supporting requirements acquisition by extracting important requirements and creating requirements model from requirements list.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Comment statements are important in understanding a source code. A thorough writing of comments in a source code leads the developers to more carefully review of the code by themselves, which would aid to detect software faults, and those careful review could preserve high quality of the code. A previous study has shown that a source code including more comments would have more maintainability. While the study has focused on only a comment density, a comment frequency would be important measure as well. As a further study, this paper performs a statistical analysis with 4,521 version-upgrade cases in one open-source software "Eclipse". The empirical results show that more comments are related to more maintainability, in middle or large scale code (LOC≧67). However the higher frequency of comment description is corresponded to the lower maintainability.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In recent years, the orthogonal array has been a key topic to enhance software testing. The orthogonal array can be used for generating necessary combinations of experimental factors efficiently. Such a combination-generation ability could be applied into software testing methodologies. This paper develops a support tool for the software unit testing, OTGforJUnit. It can automatically generate necessary combinations of method-invocations for an efficient testing, based on the concept of orthogonal array. The tool is designed to support the well-known unit testing framework for Java programs, JUnit. The empirical study shows that OTGforJUnit would contribute to efficient testings and fault detections.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：Ehime University  

In software development, comprehensive software reviews and testings are important activities to preserve high quality and to control maintenance cost. However it would be actually difficult to perform comprehensive software reviews and testings because of a lot of components, a lack of manpower and other realistic restrictions. To improve performances of reviews and testings in object-oriented software, this paper proposes a novel model for detecting cost-prone classes; the model is based on Mahalanobis-Taguchi method. an extended statistical discriminant method merging with a pattern recognition approach. Experimental results using a lot of Java software are provided to statistically demonstrate that the proposed model has a high ability for detecting cost-prone classes.

CiNii Books

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Other Link： http://iyokan.lib.ehime-u.ac.jp/dspace/handle/iyokan/1485

Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

This paper focuses on the stability of source code in open source development, and categorizes source code into four levels of stability. An empirical study is performed using a practical open source software, Eclipse, for collecting empirical data and analyzing them on source code stability. The empirical results show the following two tendencies: (1) a long-time maintenance (more than 400 days in this case) would produce a low-stability code; (2) a code that was stable during the first 100 days after the initial release, would keep its high-stability even if the external specification was changed.

CiNii Books

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Other Link： http://id.nii.ac.jp/1001/00021181/

Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper is a report on the seventh Joint conference on Knowledge-Based Software Engineering (JCKBSE2006). JCKBSE 2006 held in Tallinn, the capital of Estonia, from August 28th to 31st. JCKBSE has been held in Russian Federation or Eastern European countries biyearly. For JCKBSE 2006, 50 papers were submitted and 37 papers were selected. In the conference, 46 researchers on knowledge-based software engineering participated from 13 countries including Japan, Estonia, Australia and Greece, and they made useful presentations and had meaningful discussions.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

To aid software maintenance, there have been some studies to identify the potential impacts of code modification on other code. While dependency analysis is a useful method for analyzing those potential impacts, that method may find too many candidates to check their modifications for the consistent code updates in a large scale software. This paper defines a detailed category for dependent relationships, and performs an empirical study using a large scale software, Eclipse. The empirical results show that class design changes, such as changes in inheritance or interface, have high potentials to cause other code modifications.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Requirements acquisition process is the first stage in a software development process, that has significant impacts on the following stage. While this process is important, software developer provide inadequate technical support. A business process is one of the techniques of requirements acquisition. If the business process is specified, software developer understand what I should just do. Therefore, I propose the idea of supporting for making business process models.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In object-oriented software development, many software developers use existed classes to build their products efficiently. Such develpment style is a software reuse, and that is an effective method to develop quality software having high maintainability. This paper focuses on relationships between the above reuse level (ratio of method invocations and field accesses to other classes) and code maintainability in classes, and performs a statistical analysis concerning impacts of class-reuse on source code changes through their version-upgrades. The empirical results show that class reuse is a useful approach but more reuse (grater than 26% code reuse) would decrease the maintainability.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Cohesion is an important quality attribute of software module. It means a strength of functional relationships among module components. In general, the more cohesive module would be easier for maintaining the module. The quality attribute can be discussed in object-oriented software as well; an object class corresponds to a software module, and the class members (attributes and methods) are the module components. That is called "class cohesion," and some metrics for measuring class cohesion have been proposed in the literature. This paper discusses some impacts of class cohesion metrics on a maintainability of class, especially source code change rate through version-upgrades in corrective maintenance. The empirical study shows some metrics have statistically significant relationships with Java source code change rate.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper focuses on "change chains" in version-upgrades of source code, that are the chains of modifications for the common code fragments. Such chains indicate fails in the code maintenance, and cause more maintenance cost. An empirical study is performed in this paper to investigate and analyze characteristics of change chains in a large scale software, Eclipse. The empirical results show that (1) the smaller code have the higher potential to make change chains in their version-upgrades; (2) even small modifications would cause long change chains.

CiNii Books

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Language：Japanese   Publisher：Forum on Information Technology  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Software maintenance activities perform many changes in their source codes. It is important to analyze impacts of those changes for a successful software maintenance. A major goal of impact analysis is to identify the software products affected by changes proposed during a maintenance activity, and the identification would be performed through an analysis of dependencies among products. On such dependency analysis, this paper focuses on the "activated time" of a product (an object-class) in a software repository, and proposes a model of synchronized-upgrade based on class change histories in a repository and dependencies among classes. The model is built for predicting a synchronized-upgrade in a class pair. An empirical work using an open source software "Eclipse" shows that the proposed model is useful in predicting a class pair upgraded synchronously during the software maintenance activity.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Cohesion is an important quality attribute of software module. It means a strength of functional relationships among module components. In general, the more cohesive module would be easier for maintaining the module. The quality attribute can be discussed in object-oriented software as well; an object class corresponds to a software module, and the class members (attributes and methods) are the module components. That is called "class cohesion, " and some metrics for measuring class cohesion have been proposed in the literature. This paper discusses some impacts of class cohesion metrics on a maintainability of class, especially source code changing rate through version-upgrades. The empirical study shows some metrics have statistically significant relationships with Java source code changing rate.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Recently the open source software development has been a major development approach. While the open source development approach is a beneficial in improving software quality, it would be difficult to perform quality control and to estimate maintenance cost since we could not collect the most of management data such as development time/effort went into the products; narrow available data are the products (source code) and their failure reports. This paper studies the relationships between failure reports and modification cost in version-upgrade. An empirical work on a practical open source software "Eclipse" is presented, and the empirical results found a strong correlation between failure reports and modification cost.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Software development and maintenance activities trend toward higher cost because of increasing software size and complexity with sophisticated computer equipments. To control development/maintenance cost and to improve quality, a software reuse is an effective approach. In object-oriented software development, class-reuse is frequently practiced as well. This paper focuses on relationships between class-reuse and maintainability, and performs statistical analysis concerning impacts of class-reuse on source code changing in version-upgrades of Java software.

CiNii Books

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Language：Japanese   Publisher：Ehime University  

When some different software metrics measure a software attribute, they have to capture different aspects of the software attribute independently. In other words, if there are n metrics, they have to provide n-dimensioual information about the software attribute. Otherwise, some of them would be redundant. The contribution of this paper is to provide a new method for verifying metrics using the principal component analysis and the correlation analysis. This method can verify metrics in terms of the following two points : (1) How many aspects could be measured by those metrics, and (2) Whether some metrics would be redundant or not.

CiNii Books

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Other Link： http://iyokan.lib.ehime-u.ac.jp/dspace/handle/iyokan/1413

Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Cohesion is one of software attributes representing the degree to which the components are functionally connected within a software module. In a procedural program, procedures and functions can be regarded as a set of modules, and can be evaluated using the concept of module cohesion. Object class can also be evaluated in a similar way : Since a class instance consists of some methods and attributes, the class cohesion can be considered using the functional connections among the class components. This paper focuses on method associations through attribute accesses, then proposes new metrics measuring class cohesion by quantifying extents of method associations. These metrics will capture some aspects of class cohesion, which could not be represented by traditional metrics. Furthermore, these metrics are satisfying the mathematical propeties of cohesion metrics which have been proposed by Briand and others.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In order to support requirements acquisition activities, this paper propose some approaches for improving communicativity of requirements information. These approaches consist of to extract keywords from requirement documents and to construct model diagrams such as use case diagram, activity diagram and so on. To extract keywords, this paper focuses on a thinking support method which is based on interrogatives such as "What", "How", and so on. These approaches are applied to a practical example, then evaluated on their usefulness.

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

Cohesion is a useful attribute to assess object-oriented class designs. In order to provide assessments of class cohesion in terms of splitting the set of methods within the class, several metrics have been proposed. While these are based on the number of split sets, they have never considered sizes of those sets. They also have never considered degrees of functional relationships among methods. In this paper, two new metrics for class cohesion have been proposed, which are focusing on sizes of split sets of methods, and on extents to which methods are strongly related. These proposed metrics are analytically validated using a mathematical framework.

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In decision making for personnel stationing problem,We introduce a vector depending on each object(alternative)of decision making into inner product vector space(X_1,V^n_1). All vectors in V^n_1 are mapped onto two dimensional plane(obserbation plane(X_0,V^2_0))by any pair of the vectors(pair of subjctive observation vectors)depending on stations. We can widely observe the character of alternatives through some observation planes V^2.

CiNii Books

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Event date： 2015.12

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Event date： 2008.9

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Event date： 2008.3

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Event date： 2007.3

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