ソフトウェアの不具合予測は，ソフトウェアに潜む不具合を予測することで効率的なレビューやテストを可能にしようとするソフトウェア品質保証活動の 1 つである.従来の多くのソフトウェアの不具合予測では，ソースコード分析による不具合予測を行なっているが，粒度が荒くまた不具合予測の結果のフィードバックが遅い.この問題を解決するために，ソフトウェアの変更がコミットされた時に，その変更によって不具合が起きるかどうかを予測する手法が提案され，近年注目を集めている.ソフトウェア の変更コミットの不具合予測に関する既存研究では，その変更に対するメトリクス(例えば，修正されたファイル数，追加されたコード行数など)を計算した後に機械学習や深層学習を適用している.それに対して，本研究では，変更のソースコード片のみに対して深層学習を適用することで不具合を予測する手法
(W-CNN)を提案する.我々は，評価実験によって，変更ソースコード片に対する深層学習を用いた不具合予測が可能であること，更に，提案手法 W-CNN は先行研究に比べて，学習の時間はかかるものの，不具合予測の精度が優れていることを示す.

関連論文

• 近藤 将成, 森 啓太, 水野 修, 崔 銀惠, "深層学習によるソースコードコミットからの不具合混入予測," 情報処理学会論文誌, 59(4), pp. 1250-1261, 2018年4月.
• 近藤 将成, 森 啓太, 水野 修, 崔 銀惠, "深層学習による不具合混入コミットの予測と評価," ソフトウェアエンジニアリングシンポジウム2017論文集 (SES2017) , pp. 35-44, 2017年8月. (東京都)
• 森 啓太, "深層学習による不具合混入コミットの予測モデルの提案とその評価," 修士学位論文, 京都工芸繊維大学 大学院工芸科学研究科, 2017年.
• 近藤 将成, 森 啓太, 水野 修, 崔 銀惠, "最優秀論文賞: 深層学習による不具合混入コミットの予測と評価," ソフトウェアエンジニアリングシンポジウム2017 (SES2017), 2017年8月.

Detecting anomalies of a cyber physical system (CPS), which is a complex system consisting of both physical and software parts, is important because a CPS often operates autonomously in an unpredictable environment.
However, because of the ever-changing nature and lack of a precise model for a CPS, detecting anomalies is still a challenging task.
To address this problem, we propose applying an outlier detection method to a CPS log.
By using a log obtained from an actual aquarium management system, we evaluated the effectiveness of our proposed method by analyzing outliers that it detected.
By investigating the outliers with the developer of the system, we confirmed that some outliers indicate actual faults in the system.
For example, our method detected failures of mutual exclusion in the control system that were unknown to the developer.
Our method also detected transient losses of functionalities and unexpected reboots.
On the other hand, our method did not detect anomalies that were too many and similar.
In addition, our method reported rare but unproblematic concurrent combinations of operations as anomalies.
Thus, our approach is effective at finding anomalies, but there is still room for improvement.

Open Data

A log of CPS system, Aqua-tan, recorded from the beginning of system operation.
The log files contain id, timestamp, label, numeric value, and text value.
The “label” column denotes commands and events of Aqua-tan system.

This data is analyzed in our paper in IWESEP2017[1].

• Data: log.csv

References

• Y. Harada, Y. Yamagata, O. Mizuno, and E. Choi, "Log-Based Anomaly Detection of CPS Using a Statistical Method," In Proc. of the 8th IEEE International Workshop on Empirical Software Engineering in Practice (IWESEP2017), pp. 1-6, March 2017.
• Y. Harada, Y. Yamagata, O. Mizuno, and E. Choi, "Best Paper Award: a Log-Based Anomaly Detection of Cps Using a Statistical Method," In the 8th IEEE International Workshop on Empirical Software Engineering in Practice (IWESEP2017), March 2017.

ソフトウェアのバグが報告されると，開発者はバグ修正のためにバグに関連するソースコードファイルを特定する必要がある．この過程は，不具合ファイル特定と呼ばれ，不具合ファイル特定の自動化は開発者の生産性向上のために重要である．本研究では，単語分散表現作成のための自然言語処理ツールword2vecによって学習されるベクトル空間モデルsemantic-VSMを用いて，与えられたバグ報告に対する不具合ファイル特定を効果的に行う手法を提案する．また，不具合ファイル特定の正答率を向上させるために，semantic-VSMとともに既存の不具合ファイル特定手法BugLocator及びBugspotsを組み合わせて用いる手法CombBLを紹介する．我々の実験結果は，提案手法の正答率が既存の高水準の不具合ファイル特定手法と比べて大幅には劣らない結果を達成していることを示す．また我々は，提案手法が既存手法に比べてスケーラビリティ及び高速さにおいては優れている点について考察した．

研究発表

• Y. Uneno, O. Mizuno, and E. Choi, "Using a Distributed Representation of Words in Localizing Relevant Files for Bug Reports," In Proc. of the 2016 IEEE International Conference on Software Quality, Reliability & Security (QRS2016), pp. 183-190, August 2016.
• 釆野, 水野, 崔, "Word2Vecを用いたバグ報告からの不具合ファイル特定," 電子情報通信学会技術研究報告, 115(SS2015-85), pp. 55-60, 2016年3月.
• 釆野, "単語分散表現を用いたバグ報告からの不具合ファイル特定," 修士学位論文, 京都工芸繊維大学大学院工芸科学研究科, 2016年.
• 釆野, 水野, "Word2Vecを利用したバグ報告に対する修正対象推薦手法," ソフトウェア信頼性研究会FORCE2015予稿集, 2015年11月.
• Y. Uneno and O. Mizuno, "Identifying Bug Injected Files from Bug Description Using Word2vec," In Poster presentation of 6th International Workshop on Empirical Software Engineering in Practice (IWESEP2014), November 2014.

可視化

概要

組み合わせテスト手法は，少ないテストケースで効率的なテストを実施するための手法です．
本研究室では，組み合わせテストにおける優先度付けに対するデータマイニング的アプローチや組み合わせテストにおけるコードカバレッジの調査などを行っています．

研究成果

• 西浦, 水野, 崔, "Javaテストコードの再利用による自動生成に向けた移植可能なテストメソッドの調査," 情報処理学会論文誌, 62(4), pp. 1019-1028, 2021年4月.
• M. Jiang, T. Y. Chen, F. Kuo, Z. Ding, E. Choi, and O. Mizuno, "A Revisit of the Integration of Metamorphic Testing and Test Suite Based Automated Program Repair," In Proc. of 2017 IEEE/ACM 2nd International Workshop on Metamorphic Testing (MET2017) (In conjunction with ICSE2017), pp. 14-20, May 2017. (Buenos Aires, Argentina) (Acceptance rate: 83.3%)
• E. Choi, T. Fujiwara, and O. Mizuno, "Weighting for Combinatorial Testing by Bayesian Inference," In Proc. of 10th IEEE International Conference on Software Testing Verification and Validation Workshop (ICST2017), Posters track, pp. 189-191, March 2017. (Tokyo, Japan)
• 藤原, "ベイズ推定による優先度付き組み合わせテストの改良と不具合発見傾向の評価," 修士学位論文, 京都工芸繊維大学 大学院工芸科学研究科, 2017年.
• E. Choi and O. Mizuno, "Towards Quality Improvement and Analysis of Combinatorial Testing," In ウィンターワークショップ2017・イン・飛騨高山, pp. 13-14, January 2017.
• E. Choi, O. Mizuno, and Y. Hu, "Code Coverage Analysis of Combinatorial Testing," In Proc. of 4th International Workshop on Quantitative Approaches to Software Quality (QuASoQ 2016), pp. 34-40, December 2016. (Hamilton, New Zealand)
• 西浦, 崔, 水野, "ロジスティック回帰分析を用いた組合せテストの不具合特定法の提案," FOSEソフトウェア工学の基礎研究会(FOSE2016), pp. 243-244, 2016年12月.
• E. Choi, C. Artho, T. Kitamura, O. Mizuno, and A. Yamada, "Distance-Integrated Combinatorial Testing," In Proc. of 27th International Symposium on Software Reliability Engineering (ISSRE2016), pp. 93-104, October 2016. (Ottawa, Canada) (Acceptance rate: 35%, 45/130)
• E. Choi, S. Kawabata, O. Mizuno, C. Artho, and T. Kitamura, "Test Effectiveness Evaluation of Prioritized Combinatorial Testing: a Case Study," In Proc. of the 2016 IEEE International Conference on Software Quality, Reliability & Security (QRS2016), pp. 61-68, August 2016. (Vienna, Austria) (Acceptance rate: 43%, 48/111)
• 河端, 崔, 水野, "ベイズ推定を用いた組み合わせテスト最適化手法の提案," 電子情報通信学会技術研究報告, 115(SS2015-95), pp. 115-120, 2016年3月. (宮古島市, 沖縄県)
• 水野, "「みんなのラズパイコンテスト」グランプリ作品: 移動して給餌する水槽管理ロボット〜目的の位置で撮影してツイート〜 (Raspberry Piで楽しいモノ作り) ," 日経Linux, 17(4), pp. 77-83, 2015年4月.
• E. Choi, H. Nishihara, T. Ando, N. V. Tang, M. Aoki, K. Yoshisaka, O. Mizuno, and H. Osaki, "Formal Specification Based Automatic Test Generation for Embedded Network Systems," Journal of Applied Mathematics, 2014(Article ID 909762), 21pages, May 2014. (JCR: 0.834 )
• T. Ando, S. Kawasaki, E. Choi, H. Nishihara, M. Aoki, K. Yoshioka, K. Shimatani, M. Furuichi, and O. Mizuno, "Development of Formal Model Based Test -- Toward Automatic Testing Framework for Embedded Systems --," In Proc. of 22nd International Symposium on Software Reliability Engineering (ISSRE2011), Supplemental proceedings, 4-4, November 2011. (Hiroshima, Japan)
• T. Sumi, O. Mizuno, T. Kikuno, and M. Hirayama, "An Effective Testing Method for Hardware Related Fault in Embedded Software," IEICE Trans. on Information and Systems, E88-D(6), pp. 1142-1149, June 2005. (JCR: 0.242 (2005))
• M. Hirayama, O. Mizuno, and T. Kikuno, "Analysis of Software Test Item Generation --- Comparison between High Skilled and Low Skilled Engineers ---," Journal of Computer Science and Technology, 20(2), pp. 250-257, March 2005. (JCR: 0.353 (2005))
• M. Hirayama, O. Mizuno, and T. Kikuno, "Test Item Prioritizing Metrics for Selective Software Testing," IEICE Trans. on Information and Systems, E87-D(12), pp. 2733-2743, December 2004. (JCR: 0.274 (2004))
• M. Hirayama, T. Yamamoto, O. Mizuno, and T. Kikuno, "Analysis of Software Test Item Generation --- Comparison between High Skilled and Low Skilled Engineers ---," In Proc. of 12th Asian Test Symposium (ATS03), pp. 210-215, November 2003. (Xian, China)
• O. Mizuno, E. Shigematsu, Y. Takagi, and T. Kikuno, "On Estimating Testing Effort Needed to Assure Field Quality in Software Development," In Proc. of 13th International Symposium on Software Reliability Engineering (ISSRE2002), pp. 139-146, November 2002. (Annapolis, MD, USA.) (Acceptance rate: 45%, 33/73)
• S. Amasaki, T. Yoshitomi, O. Mizuno, T. Kikuno, and Y. Takagi, "Statistical Analysis of Time Series Data on the Number of Faults Detected by Software Testing," In Proc. of 11th Asian Test Symposium (ATS02), pp. 272-277, November 2002. (Guam, USA.)
• M. Hirayama, T. Yamamoto, J. Okayasu, O. Mizuno, and T. Kikuno, "Elimination of Crucial Faults by a New Selective Testing Method," In Proc. of 1st Internationl Symposium on Empirical Software Engineering (ISESE2002), pp. 183-191, October 2002. (Nara, Japan.) (Acceptance rate: 60%, 20/33)
• M. Hirayama, T. Yamamoto, J. Okayasu, O. Mizuno, and T. Kikuno, "Elimination of Crucial Faults for Embedded Software Using Functional Priority Testing," In Proc. of 6th International Conference on Probabilistic Safety Assessment and Management (PSAM6), pp. 715-721, June 2002. (Puerto Lico, USA.)
• 重松, 水野, 菊野, 高木, "フィールド不具合数を許容値以下に抑えるためのソフトウェアテスト工数の推定モデルの提案," 電子情報通信学会技術研究報告, 101(629, SS2001-35), pp. 9-15, 2002年1月.
• M. Hirayama, T. Yamamoto, J. Okayasu, O. Mizuno, and T. Kikuno, "A Selective Software Testing Method Based on Priorities Assigned to Functional Modules," In Proc. of 2nd Asia-Pacific Conference on Quality Software (APAQS2001), pp. 259-267, December 2001. (HongKong, China.) (Acceptance rate: 34%, 34/100)
• 平山, 山本, 岡安, 水野, 菊野, "機能モジュールに対する優先度に基づいた選択的ソフトウェアテスト手法の提案," 電子情報通信学会技術研究報告, 101(97-98, SS2001-6), pp. 1--8, 2001年5月.
• M. Hirayama, J. Okayasu, T. Yamamoto, O. Mizuno, and T. Kikuno, "Generating Test Items for Checking Illegal Behaviors in Software Testing," In Proc. of 9th Asian Test Symposium (ATS2000), pp. 235-240, December 2000. (Taipei, Taiwan.)
• M. Hirayama, T. Yamamoto, T. Kishimoto, O. Mizuno, and T. Kikuno, "Systematic Generation of Software Test Items Based on System Behavior from User's Viewpoint," In Proc. of International Conference on Probabilistic Safety Assessment and Management (PSAM5), pp. 2377-2382, November 2000. (Osaka, Japan.)
• 平山, 岸本, 水野, 菊野, "UseCaseを利用したソフトウェアフォールトに対するSS-FTAの提案," 電子情報通信学会技術研究報告, 99(547-548, SS99-53), pp. 25-32, 2000年1月.

We intend to assess the improvements of Gerrit. The central
concern is “Does Rietveld evolve into Gerrit as the developers intended?” To answer
this question, we first compare qualitative features of two code review tools. We
then conducted an interview with a developer of Gerrit and obtained the developer’s
original intention of improvements in Gerrit. By analyzing mined data from code
review logs, we try to explain the effects of improvements quantitatively. The result
of analysis showed us that the improvements of Gerrit that the developer is expected
are not observed explicitly.

References:

• O. Mizuno and J. Liang, "Analysis of a Code Review Tool Evolution-- a Case Study of Rietveld to Gerrit --," ACIS International Journal of Software Innovation, 3(1), pp. 16-35, January 2015.
• O. Mizuno and J. Liang, "Does a Code Review Tool Evolve as the Developer Intended?," In Proc. of 12th International Conference on Software Engineering Research, Management and Applications (SERA2014), Studies in Computational Intelligence, 578, pp. 59-74, August 2014.
• J. Liang, "A Comparison and Analysis of Modern Code Review in Open Source Software Projects," Master thesis, Graduate School of Science and Technology, Kyoto Institute of Technology, 2013.
• J. Liang and O. Mizuno, "Analyzing Involvements of Reviewers Through Mining a Code Review Repository," In Proc. of the Joint Conference of the 21th International Workshop on Software Measurement and the 6th International Conference on Software Process and Product Measurement (IWSM/MENSURA2011), pp. 126-132, November 2011.
• J. Liang, O. Mizuno, "オープンソースソフトウェアのコードレビューにおけるレビュアーの活動の分析," 平成23年度情報処理学会関西支部大会講演論文集, B-01, September 2011.

The fault-prone module detection in source code is of importance for assurance of software quality. Most of previous fault-prone detection approaches are based on software metrics. Such approaches, however, have difficulties in collecting the metrics and constructing mathematical models based on the metrics.

In order to mitigate such difficulties, we propose a novel approach for detecting fault-prone modules using a spam filtering technique, named Fault-Prone Filtering. Because of the increase of needs for spam e-mail detection, the spam filtering technique has been progressed as a convenient and effective technique for text mining. In our approach, fault-prone modules are detected in a way that the source code modules are considered as text files and are applied to the spam filter directly.

In order to show the usefulness of our approach, we conducted an experiment using a large source code repository of Java based open source project. The result of experiment shows that our approach can classify about 85% of software modules correctly. The result also indicates that fault-prone modules can be detected relatively low cost at an early stage.

Related paper:

• 西浦, 門田, "Fault-proneモジュール予測における第三者データに基づいた外れ値除去," コンピュータソフトウェア, 40(4), pp. 22-28, 2023年.
• 瀬戸, 西浦, 門田, "相関ルールとランダムフォレストを組合わせたfault-proneモジュール予測の追実験," 情報処理学会論文誌, 63(8), pp. 1352-1360, 2022年8月.
• A. Yamada and O. Mizuno, "Classification of Bug Injected and Fixed Changes Using a Text Discriminator," ACIS International Journal of Software Innovation, 3(1), pp. 50-62, January 2015.
• O. Mizuno, N. Kawashima, and K. Kawamoto, "Fault-Prone Module Prediction Approaches Using Identifiers in Source Code," ACIS International Journal of Software Innovation, 3(1), pp. 36-49, January 2015.
• O. Mizuno and H. Hata, "A Metric to Detect Fault-Prone Software Modules Using Text Classifier," International Journal of Reliability and Safety, 7(1), pp. 17-31, February 2013.
• 畑, 水野, 菊野, "開発履歴メトリクスを用いた細粒度な Fault-prone モジュール予測," 情報処理学会論文誌, 53(6), pp. 1635-1643, 2012年6月.
• O. Mizuno and M. Nakai, "Can Faulty Modules Be Predicted by Warning Messages of Static Code Analyzer?," Advances in Software Engineering, 2012(924923), 8 pages, May 2012.
• 水野, 畑, "スパムフィルタを用いたFault-proneモジュール検出法の予測精度に関する従来法との比較評価," 電子情報通信学会論文誌D, J94-D(1), pp. 409-412, 2011年1月.
• O. Mizuno and H. Hata, "A Hybrid Fault-Proneness Detection Approach Using Text Filtering and Static Code Analysis," International Journal of Advancements in Computing Technology, 2(5), pp. 1-12, December 2010.
• H. Hata, O. Mizuno, and T. Kikuno, "Fault-Prone Module Detection Using Large-Scale Text Features Based on Spam Filtering," Empirical Software Engineering, 15(2), pp. 147-165, April 2010. (JCR: 1.612 (2009))
• O. Mizuno and H. Hata, "Prediction of Fault-Prone Modules Using a Text Filtering Based Metric," International Journal of Software Engineering and Its Application, 4(1), pp. 43-52, January 2010.
• O. Mizuno and T. Kikuno, "Prediction of Fault-Prone Software Modules Using a Generic Text Discriminator," IEICE Trans. on Information and Systems, E91-D(4), pp. 888-896, April 2008. (JCR: 0.369 (2008))
• 水野, 菊野, "Fault-Prone フィルタリング： 不具合を含むモジュールのスパムフィルタを利用した予測手法," SEC journal, 4(1), pp. 6-15, 2008年2月.
• T. Fujiwara, O. Mizuno, and P. Leelaprute, "Fault-Prone Byte-Code Detection Using Text Classifier," In Proc. of 16th International Conference on Product-Focused Software Process Improvement (PROFES2015), 1st International Workshop on Processes, Methods, and Tools for Engineering Embedded Systems, LNCS(9459), pp. 415-430, December 2015. (Bozen-Bolzano, Italy)
• K. Mori and O. Mizuno, "An Implementation of Just-In-Time Fault-Prone Prediction Technique Using Text Classifier," In Proc. of the 39th IEEE Computers, Software, and Applications Conference (COMPSAC 2015), pp. 609-612, July 2015. (Taichung, Taiwan)
• O. Mizuno and Y. Hirata, "A Cross-Project Evaluation of Text-Based Fault-Prone Module Prediction," In Proc. of 6th International Workshop on Empirical Software Engineering in Practice (IWESEP2014), pp. 43-48, November 2014. (Osaka, Japan) (Acceptance rate: 56%, 10/18)
• A. Yamada and O. Mizuno, "A Text Filtering Based Approach to Classify Bug Injected and Fixed Changes," In Proc. of 12th International Conference on Software Engineering Research, Management and Applications (SERA2014), pp. 680-686, August 2014. (Kitakyushu, Japan) (Acceptance rate: 59%, 19/32)
• N. Kawashima and O. Mizuno, "Predicting Fault-Prone Modules by Word Occurrence in Identifiers," In Proc. of 12th International Conference on Software Engineering Research, Management and Applications (SERA2014), Studies in Computational Intelligence , 578, pp. 87-98, August 2014. (Kitakyushu, Japan) (Acceptance rate: 59%, 19/32)
• O. Mizuno, "On Effects of Tokens in Source Code to Accuracy of Fault-Prone Module Prediction," In Proc. of the 17th International Computer Science and Engineering Conference (ICSEC2013), 103 - 108, September 2013. (Bangkok, Thailand) (Acceptance rate: 57%, 73/128)
• K. Kawamoto and O. Mizuno, "Predicting Fault-Prone Modules Using the Length of Identifiers," In Proc. of 4th International Workshop on Empirical Software Engineering in Practice (IWESEP 2012), pp. 30-34, October 2012. (Osaka, Japan) (Acceptance rate: 8/14, 57%)
• Y. Hirata and O. Mizuno, "Investigating Effects of Tokens on Detecting Fault-Prone Modules by Text Filtering," In Proc. of 22nd International Symposium on Software Reliability Engineering (ISSRE2011), Supplemental proceedings, 3-2, November 2011. (Hiroshima, Japan)
• M. Nakai and O. Mizuno, "Fault-Prone Module Prediction by Filtering Warning Messages of Static Code Analyzer," In Proc. of the Joint Conference of the 21th International Workshop on Software Measurement and the 6th International Conference on Software Process and Product Measurement (IWSM/MENSURA2011), Fast abstracts, pp. 18-21, November 2011. (Nara, Japan)
• Y. Hirata and O. Mizuno, "Do Comments Explain Codes Adequately? -- Investigation by Text Filtering --," In Proc. of 8th Working Conference on Mining Software Repositories (MSR2011), pp. 242-245, May 2011. (Honolulu, HI, USA)
• O. Mizuno and Y. Hirata, "Fault-Prone Module Prediction Using Contents of Comment Lines," In Proc. of International Workshop on Empirical Software Engineering in Practice 2010 (IWESEP2010), pp. 39-44, December 2010. (NAIST, Nara, Japan) (Acceptance rate: 66%)
• O. Mizuno and H. Hata, "An Empirical Comparison of Fault-Prone Module Detection Approaches: Complexity Metrics and Text Feature Metrics," In Proc. of 34th Annual IEEE Computer Software and Applications Conference (COMPSAC2010), pp. 248-249, July 2010. (Seoul, Korea)
• O. Mizuno and H. Hata, "An Integrated Approach to Detect Fault-Prone Modules Using Complexity and Text Feature Metrics," In Proc. of 2010 International Conference on Advanced Science and Technology (AST2010), LNCS 6059, pp. 457-468, June 2010. (Miyazaki, Japan)
• O. Mizuno and H. Hata, "Yet Another Metric for Predicting Fault-Prone Modules," In Proc. of 2009 International Conference on Advanced Software Engineering & Its Applications (ASEA2009), CCIS 59, pp. 296-304, December 2009. (Cheju, Korea)
• H. Hata, O. Mizuno, and T. Kikuno, "Comparative Study of Fault-Proneness Filtering with PMD," In Proc. of 19th International Symposium on Software Reliability Engineering (ISSRE2008), pp. 317-318, November 2008. (Seattle/Redmond, WA, USA) (Acceptance rate: 37%, 11/30)
• H. Hata, O. Mizuno, and T. Kikuno, "An Extension of Fault-Prone Filtering Using Precise Training and a Dynamic Threshold," In Proc. of 5th Working Conference on Mining Software Repositories (MSR2008), pp. 89-97, May 2008. (Leipzig, Germany) (Acceptance rate: 19%)
• T. Kondou, O. Mizuno, and T. Kikuno, "Investigating Factors Affecting Accuracy of Fault-Prone Filtering," In Proc. of 18th International Symposium on Software Reliability Engineering (ISSRE2007), Supplemental proceedings, CD-ROM, November 2007. (Trollhattan, Sweden)
• T. Yagi, O. Mizuno, and T. Kikuno, "Analysing Effect of Pre-Training in Fault-Prone Prediction Using Spam Filter," In Proc. of 18th International Symposium on Software Reliability Engineering (ISSRE2007), Supplemental proceedings, CD-ROM, November 2007. (Trollhattan, Sweden)
• O. Mizuno, S. Ikami, S. Nakaichi, and T. Kikuno, "Fault-Prone Filtering: Detection of Fault-Prone Modules Using Spam Filtering Technique," In Proc. 1st International Symposium on Empirical Software Engineering and Measurement (ESEM2007), pp. 374-383, September 2007. (Madrid, Spain) (Acceptance rate: 41%, 44/107)
• O. Mizuno and T. Kikuno, "Training on Errors Experiment to Detect Fault-Prone Software Modules by Spam Filter," In The 6th joint meeting of the European Software Engineering Conference and the ACM SIGSOFT Symposium on the Foundations of Software Engineering (ESEC/FSE2007), pp. 405-414, September 2007. (Dubrovnik, Croatia) (Acceptance rate: 17%, 43/251)
• M. Kimoto, O. Mizuno, and T. Kikuno, "Extraction of Fault-Prone Modules Based on Fault Tracking Data from Open Source Software Repository," In 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN2007), Supplemental Proceedings, pp. 366-367, June 2007. (Edinburgh, UK)
• O. Mizuno, S. Ikami, S. Nakaichi, and T. Kikuno, "Spam Filter Based Approach for Finding Fault-Prone Software Modules," In Proc. of Fourth International Workshop on Mining Software Repositories (MSR07), p. 4, May 2007. (Minneapolis, MN, USA) (Acceptance rate: 51%)
• 西浦, 門田, "Fault-proneモジュール予測における第三者データに基づいた外れ値除去," 第29回ソフトウェア工学の基礎ワークショップ (FOSE2022)論文集, pp. 153-158, 2022年11月.
• 森, 水野, "スパムフィルタに基づく即時バグ予測ツールの試作," ソフトウェア・シンポジウム2015, pp. 37-46, 2015年6月.
• 藤原, 水野, "バイトコードを用いたテキスト分類による不具合予測," ソフトウェア・シンポジウム2015, pp. 80-88, 2015年6月.
• 川島, 水野, "識別子中の単語情報を用いた Fault-prone モジュール予測," ソフトウェアシンポジウム2014論文集, pp. 72-80, 2014年6月. (秋田市)
• 畑, 水野, 菊野, "開発履歴メトリクスに基づくfault-proneモジュール予測の細粒度モジュールへの適用," ソフトウェアエンジニアリングシンポジウム2011(SES2011), 4, 2011年9月.
• 中井, 水野, "ソースコード静的解析結果を利用した不具合混入モジュールの予測手法の提案," ソフトウェア・シンポジウム2011, 09_研究論文 (Online only), 2011年6月. (長崎市)
• 畑, 水野, 菊野, "負例を用いない機械学習によるfault-proneモジュール検出," ソフトウェアエンジニアリングシンポジウム2009 (SES2009), pp. 133-138, 2009年9月. (東京)
• 水野, "Fault-proneness Filtering： スパムフィルタに基づく不具合混入ソフトウェアモジュールの予測手法," 生産と技術, 61(1), pp. 38-43, 2009年1月.
• 水野, 黒田, 石原, 山下, "テキスト分類による不具合予測システムの実装と企業環境での評価," 電子情報通信学会技術報告, SS2020-17, 電子情報通信学会, 2021年1月.
• 平田, 水野, "テキスト分類に基づくFault-proneモジュール検出法におけるコメント行の影響の分析," 情報処理学会研究報告 ソフトウェア工学(SE), 2010-SE-170(10), pp. 1-8, 2010年11月. (大阪大学)
• 劉, 水野, 菊野, "フォールトプローンモジュール検出手法間の精度比較 〜Fault-proneness filteringとロジスティック回帰〜," 電子情報通信学会技術報告, 108(384, KBSE2008-47), pp. 61-66, 2009年1月. (東京)
• 森井, 水野, 菊野, "ソースコード中に含まれる不具合トークンをテキスト分類に基づいて推定するツールの試作と評価," 電子情報通信学会技術研究報告, 108(64, SS2008-4), pp. 19-24, 2008年5月. (宮崎市)
• 八木, 水野, 菊野, "SPAMフィルタを用いたFault-Proneモジュールの予測 -- 異なるプロジェクトの学習結果を利用した精度評価," ソフトウェア信頼性研究会第4回ワークショップ論文集, pp. 35-43, 2007年6月. (松山市)
• 井神, 中市, 水野, 菊野, "汎用テキストフィルタを利用した不具合を含むソースコードの予測," 電子情報通信学会技術研究報告, 106(522, SS2006-75), pp. 25-30, 2007年2月. (愛知県立大学, 名古屋市)
• 川島, "識別子中の単語情報を用いたFault-proneモジュール予測手法の提案," 卒業研究報告書, 京都工芸繊維大学, 2014年2月.

Identifiers such as variable names and function names in source code are important information to understand code. The way of naming for identifiers and the length of identifiers affects on code understandability, and thus, it is guessed that they affects on software quality. In this study, we investigate the relationship between the length of identifiers and software faults in a software module. The results show that there is a certain relationship between the length of identifier and existence of software faults.

References

• O. Mizuno, N. Kawashima, and K. Kawamoto, "Fault-Prone Module Prediction Approaches Using Identifiers in Source Code," ACIS International Journal of Software Innovation, 3(1), pp. 36-49, January 2015.
• N. Kawashima and O. Mizuno, "Predicting Fault-Prone Modules by Word Occurrence in Identifiers," In Proc. of 12th International Conference on Software Engineering Research, Management and Applications (SERA2014), Studies in Computational Intelligence , 578, pp. 87-98, August 2014.
• 川島, 水野, "識別子中の単語情報を用いた Fault-prone モジュール予測," ソフトウェアシンポジウム2014論文集, pp. 72-80, 2014年6月.
• 川島, "識別子中の単語情報を用いたFault-proneモジュール予測手法の提案," 卒業研究報告書, 京都工芸繊維大学, 2014年2月.
• 椋代, "ソフトウェア開発者に着目したバグ混入コミットのトピック分析," 修士学位論文, 京都工芸繊維大学大学院工芸科学研究科, 2014年.

We are analyzing the relationship between developers in software projects. The graph shown above represents hops between developers in 8500 projects in GitHub.

A tool for calculating developer hops is found at:

• Developer Hops