Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609654
Trevor Savage, Bogdan Dit, Malcom Gethers, D. Poshyvanyk
Acquiring general understanding of large software systems and components from which they are built can be a time consuming task, but having such an understanding is an important prerequisite to adding features or fixing bugs. In this paper we propose the tool, namely TopicXP, to support developers during such software maintenance tasks by extracting and analyzing unstructured information in source code identifier names and comments using Latent Dirichlet Allocation. TopicXP enables developers to gain an overview of a software system under analysis by extracting and visualizing natural language topics, which generally correspond to concepts or features implemented in software classes. TopicXP is implemented as an open-source Eclipse plug-in, which proposes interactive visualization of topics along with structural dependencies between underlying classes implementing these topics. The paper also presents the results of a preliminary user study aimed at evaluating TopicXP.
{"title":"TopicXP: Exploring topics in source code using Latent Dirichlet Allocation","authors":"Trevor Savage, Bogdan Dit, Malcom Gethers, D. Poshyvanyk","doi":"10.1109/ICSM.2010.5609654","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609654","url":null,"abstract":"Acquiring general understanding of large software systems and components from which they are built can be a time consuming task, but having such an understanding is an important prerequisite to adding features or fixing bugs. In this paper we propose the tool, namely TopicXP, to support developers during such software maintenance tasks by extracting and analyzing unstructured information in source code identifier names and comments using Latent Dirichlet Allocation. TopicXP enables developers to gain an overview of a software system under analysis by extracting and visualizing natural language topics, which generally correspond to concepts or features implemented in software classes. TopicXP is implemented as an open-source Eclipse plug-in, which proposes interactive visualization of topics along with structural dependencies between underlying classes implementing these topics. The paper also presents the results of a preliminary user study aimed at evaluating TopicXP.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133848829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609537
Dominic Letarte
Large scale software model checking is a difficult problem in part because of the complexity created by inter-procedural function calling. Fastest current solution for this problem claim a polynomial time for only a partial resolution. Static analysis suffers of the same complexity but some work has observed linear time and space complexity for some specific problems. Our research describes how we can adapt these specific inter-procedural static analysis to model-checking and prove the linear complexity of the analysis. Construction of the graph automaton for model checking is described using graph rewriting rules applied on the control flow graph and its application to a medium scale real application.
{"title":"Conversion of fast inter-procedural static analysis to model checking","authors":"Dominic Letarte","doi":"10.1109/ICSM.2010.5609537","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609537","url":null,"abstract":"Large scale software model checking is a difficult problem in part because of the complexity created by inter-procedural function calling. Fastest current solution for this problem claim a polynomial time for only a partial resolution. Static analysis suffers of the same complexity but some work has observed linear time and space complexity for some specific problems. Our research describes how we can adapt these specific inter-procedural static analysis to model-checking and prove the linear complexity of the analysis. Construction of the graph automaton for model checking is described using graph rewriting rules applied on the control flow graph and its application to a medium scale real application.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"21 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113970557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609731
J. Brant, Don Roberts, B. Plendl, Jeff Prince
Sometimes projects need to switch implementation languages. Rather than stopping software development and rewriting the project from scratch, transformation rules can map from the original language to the new language. These rules can be developed in parallel to standard software development, allowing the project to be cut over without any loss of development time, once the rules are complete. This paper presents a migration project that used transformation rules to successfully convert 1.5 MLOC of Delphi to C# in 18 months while allowing existing Delphi development to continue.
{"title":"Extreme maintenance: Transforming Delphi into C#","authors":"J. Brant, Don Roberts, B. Plendl, Jeff Prince","doi":"10.1109/ICSM.2010.5609731","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609731","url":null,"abstract":"Sometimes projects need to switch implementation languages. Rather than stopping software development and rewriting the project from scratch, transformation rules can map from the original language to the new language. These rules can be developed in parallel to standard software development, allowing the project to be cut over without any loss of development time, once the rules are complete. This paper presents a migration project that used transformation rules to successfully convert 1.5 MLOC of Delphi to C# in 18 months while allowing existing Delphi development to continue.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123813328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609538
Jingyue Li, T. Stålhane, Jan M. W. Kristiansen, R. Conradi
To estimate the corrective software maintenance effort, we must know the factors that have the strongest influence on corrective maintenance activities. In this study, we have analyzed activities and effort of correcting 810 software defects in one Norwegian software company and 577 software defects in another. We compared the defect profiles according to the defect correction effort. We also analyzed defect descriptions and recorded discussions between developers in the course of correcting defects in order to understand what led to the high cost of correcting some types of defects. The study shows that size and complexity of the software to be maintained, maintainers?' experience, and tool and process support are the most influential cost drivers of corrective maintenance in one company, while domain knowledge is one of the main cost drivers of corrective maintenance in the other company. This illustrates that models for estimating software corrective maintenance effort have to be customized based on the defect profiles and cost drivers of each company and project to be useful.
{"title":"Cost drivers of software corrective maintenance: An empirical study in two companies","authors":"Jingyue Li, T. Stålhane, Jan M. W. Kristiansen, R. Conradi","doi":"10.1109/ICSM.2010.5609538","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609538","url":null,"abstract":"To estimate the corrective software maintenance effort, we must know the factors that have the strongest influence on corrective maintenance activities. In this study, we have analyzed activities and effort of correcting 810 software defects in one Norwegian software company and 577 software defects in another. We compared the defect profiles according to the defect correction effort. We also analyzed defect descriptions and recorded discussions between developers in the course of correcting defects in order to understand what led to the high cost of correcting some types of defects. The study shows that size and complexity of the software to be maintained, maintainers?' experience, and tool and process support are the most influential cost drivers of corrective maintenance in one company, while domain knowledge is one of the main cost drivers of corrective maintenance in the other company. This illustrates that models for estimating software corrective maintenance effort have to be customized based on the defect profiles and cost drivers of each company and project to be useful.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116019641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609582
Bonita Sharif, Jonathan I. Maletic
The effect of layout in the comprehension of design pattern roles in UML class diagrams is assessed. This work replicates and extends a previous study using questionnaires but uses an eye tracker to gather additional data. The purpose of the replication is to gather more insight into the eye gaze behavior not evident from questionnaire-based methods. Similarities and differences between the studies are presented. Four design patterns are examined in two layout schemes in the context of three open source systems. Fifteen participants answered a series of eight design pattern role detection questions. Results show a significant improvement in role detection accuracy and visual effort with a certain layout for the Strategy and Observer patterns and a significant improvement in role detection time for all four patterns. Eye gaze data indicates classes participating in a design pattern act like visual beacons when they are in close physical proximity and follow the canonical layout, even though they violate some general graph aesthetics.
{"title":"An eye tracking study on the effects of layout in understanding the role of design patterns","authors":"Bonita Sharif, Jonathan I. Maletic","doi":"10.1109/ICSM.2010.5609582","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609582","url":null,"abstract":"The effect of layout in the comprehension of design pattern roles in UML class diagrams is assessed. This work replicates and extends a previous study using questionnaires but uses an eye tracker to gather additional data. The purpose of the replication is to gather more insight into the eye gaze behavior not evident from questionnaire-based methods. Similarities and differences between the studies are presented. Four design patterns are examined in two layout schemes in the context of three open source systems. Fifteen participants answered a series of eight design pattern role detection questions. Results show a significant improvement in role detection accuracy and visual effort with a certain layout for the Strategy and Observer patterns and a significant improvement in role detection time for all four patterns. Eye gaze data indicates classes participating in a design pattern act like visual beacons when they are in close physical proximity and follow the canonical layout, even though they violate some general graph aesthetics.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115632437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609541
Bixin Li, Dong Qiu, Shunhui Ji, Di Wang
Services are highly reusable, flexible and loosely coupled, which makes the evolution and the maintenance of composite services more complex. Evolution of BPEL composite service covers changes of processes, bindings and interfaces. In this paper, an approach is proposed to select and generate test cases during the evolution of BPEL composite service. The approach identifies the changes by using control-flow analysis technique and comparing the paths in new composite service version and the old one using extensible BPEL flow graph (or XBFG). Message flow is appended to the control flow so that XBFG can describe the behavior of composite service integrally. The binding and predicate constraint information added in XBFG elements can be used in path selection and test case generation. Theory analysis and case study both show that the approach is effective, and test cases coverage rate is high for the changes of processes, bindings and interfaces.
{"title":"Automatic test case selection and generation for regression testing of composite service based on extensible BPEL flow graph","authors":"Bixin Li, Dong Qiu, Shunhui Ji, Di Wang","doi":"10.1109/ICSM.2010.5609541","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609541","url":null,"abstract":"Services are highly reusable, flexible and loosely coupled, which makes the evolution and the maintenance of composite services more complex. Evolution of BPEL composite service covers changes of processes, bindings and interfaces. In this paper, an approach is proposed to select and generate test cases during the evolution of BPEL composite service. The approach identifies the changes by using control-flow analysis technique and comparing the paths in new composite service version and the old one using extensible BPEL flow graph (or XBFG). Message flow is appended to the control flow so that XBFG can describe the behavior of composite service integrally. The binding and predicate constraint information added in XBFG elements can be used in path selection and test case generation. Theory analysis and case study both show that the approach is effective, and test cases coverage rate is high for the changes of processes, bindings and interfaces.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130193509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609696
Marios Fokaefs, Diego Serrano, B. Tansey, Eleni Stroulia
Several types of 3D software visualizations have been developed to communicate information about the products of a software project and, sometimes, the development process itself. These visualizations have been limited in the degree of interactivity they enabled (primarily panning and zooming) and in their accessibility (since in most cases they assumed a particular client platform). In this paper we discuss our 3D visualization of the data collected and extracted in our collaborative software-development platform WikiDev2.0, developed in the Open Wonderland virtual world. The visualization adopts a city metaphor, similar to earlier work, but advances the state of the art by providing a web-accessible distributed 3D environment where multiple users can explore the same project. In this paper we discuss this visualization, which we call WikiDev3D, and we report on our preliminary findings about its effectiveness against the more traditional visualization of the original WikiDev2.0 tool.
{"title":"2D and 3D visualizations in WikiDev2.0","authors":"Marios Fokaefs, Diego Serrano, B. Tansey, Eleni Stroulia","doi":"10.1109/ICSM.2010.5609696","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609696","url":null,"abstract":"Several types of 3D software visualizations have been developed to communicate information about the products of a software project and, sometimes, the development process itself. These visualizations have been limited in the degree of interactivity they enabled (primarily panning and zooming) and in their accessibility (since in most cases they assumed a particular client platform). In this paper we discuss our 3D visualization of the data collected and extracted in our collaborative software-development platform WikiDev2.0, developed in the Open Wonderland virtual world. The visualization adopts a city metaphor, similar to earlier work, but advances the state of the art by providing a web-accessible distributed 3D environment where multiple users can explore the same project. In this paper we discuss this visualization, which we call WikiDev3D, and we report on our preliminary findings about its effectiveness against the more traditional visualization of the original WikiDev2.0 tool.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130304178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609572
F. Perin, Tudor Gîrba, Oscar Nierstrasz
Java Enterprise Applications (JEAs) are large systems that integrate multiple technologies and programming languages. Transactions in JEAs simplify the development of code that deals with failure recovery and multi-user coordination by guaranteeing atomicity of sets of operations. The heterogeneous nature of JEAs, however, can obfuscate conceptual errors in the application code, and in particular can hide incorrect declarations of transaction scope. In this paper we present a technique to expose and analyze the application transaction scope in JEAs by merging and analyzing information from multiple sources. We also present several novel visualizations that aid in the analysis of transaction scope by highlighting anomalies in the specification of transactions and violations of architectural constraints. We have validated our approach on two versions of a large commercial case study.
{"title":"Recovery and analysis of transaction scope from scattered information in Java Enterprise Applications","authors":"F. Perin, Tudor Gîrba, Oscar Nierstrasz","doi":"10.1109/ICSM.2010.5609572","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609572","url":null,"abstract":"Java Enterprise Applications (JEAs) are large systems that integrate multiple technologies and programming languages. Transactions in JEAs simplify the development of code that deals with failure recovery and multi-user coordination by guaranteeing atomicity of sets of operations. The heterogeneous nature of JEAs, however, can obfuscate conceptual errors in the application code, and in particular can hide incorrect declarations of transaction scope. In this paper we present a technique to expose and analyze the application transaction scope in JEAs by merging and analyzing information from multiple sources. We also present several novel visualizations that aid in the analysis of transaction scope by highlighting anomalies in the specification of transactions and violations of architectural constraints. We have validated our approach on two versions of a large commercial case study.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130407925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609723
Shauvik Roy Choudhary, Husayn Versee, A. Orso
Cross-browser (and cross-platform) issues are prevalent in modern web based applications and range from minor cosmetic bugs to critical functional failures. In spite of the relevance of these issues, cross-browser testing of web applications is still a fairly immature field. Existing tools and techniques require a considerable manual effort to identify such issues and provide limited support to developers for fixing the underlying cause of the issues. To address these limitations, we propose a technique for automatically detecting cross-browser issues and assisting their diagnosis. Our approach is dynamic and is based on differential testing. It compares the behavior of a web application in different web browsers, identifies differences in behavior as potential issues, and reports them to the developers. Given a page to be analyzed, the comparison is performed by combining a structural analysis of the information in the page's DOM and a visual analysis of the page's appearance, obtained through screen captures. To evaluate the usefulness of our approach, we implemented our technique in a tool, called WEBDIFF, and used WEBDIFF to identify cross-browser issues in nine real web applications. The results of our evaluation are promising, in that WEBDIFF was able to automatically identify 121 issues in the applications, while generating only 21 false positives. Moreover, many of these false positives are due to limitations in the current implementation of WEBDIFF and could be eliminated with suitable engineering.
{"title":"WEBDIFF: Automated identification of cross-browser issues in web applications","authors":"Shauvik Roy Choudhary, Husayn Versee, A. Orso","doi":"10.1109/ICSM.2010.5609723","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609723","url":null,"abstract":"Cross-browser (and cross-platform) issues are prevalent in modern web based applications and range from minor cosmetic bugs to critical functional failures. In spite of the relevance of these issues, cross-browser testing of web applications is still a fairly immature field. Existing tools and techniques require a considerable manual effort to identify such issues and provide limited support to developers for fixing the underlying cause of the issues. To address these limitations, we propose a technique for automatically detecting cross-browser issues and assisting their diagnosis. Our approach is dynamic and is based on differential testing. It compares the behavior of a web application in different web browsers, identifies differences in behavior as potential issues, and reports them to the developers. Given a page to be analyzed, the comparison is performed by combining a structural analysis of the information in the page's DOM and a visual analysis of the page's appearance, obtained through screen captures. To evaluate the usefulness of our approach, we implemented our technique in a tool, called WEBDIFF, and used WEBDIFF to identify cross-browser issues in nine real web applications. The results of our evaluation are promising, in that WEBDIFF was able to automatically identify 121 issues in the applications, while generating only 21 false positives. Moreover, many of these false positives are due to limitations in the current implementation of WEBDIFF and could be eliminated with suitable engineering.","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128461081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-12DOI: 10.1109/ICSM.2010.5609545
M. Mäntylä
Low software evolvability may increase costs of software development for over 30%. In practice, human evaluations and discoveries of software evolvability dictate the actions taken to improve the software evolvability, but the human side has often been ignored in prior research. This dissertation synopsis proposes a new group of code smells called the solution approach, which is based on a study of 563 evolvability issues found in industrial and student code reviews. Solution approach issues require re-thinking of the existing implementation rather than just reorganizing the code through refactoring. This work also contributes to the body of knowledge about software quality assurance practices by confirming that 75% of defects found in code reviews affect software evolvability rather than functionality. We also found evidence indicating that context-specific demographics, i.e., role in organization and code ownership, affect evolvability evaluations, but general demographics, i.e., work experience and education, do not
{"title":"Empirical software evolvability - code smells and human evaluations","authors":"M. Mäntylä","doi":"10.1109/ICSM.2010.5609545","DOIUrl":"https://doi.org/10.1109/ICSM.2010.5609545","url":null,"abstract":"Low software evolvability may increase costs of software development for over 30%. In practice, human evaluations and discoveries of software evolvability dictate the actions taken to improve the software evolvability, but the human side has often been ignored in prior research. This dissertation synopsis proposes a new group of code smells called the solution approach, which is based on a study of 563 evolvability issues found in industrial and student code reviews. Solution approach issues require re-thinking of the existing implementation rather than just reorganizing the code through refactoring. This work also contributes to the body of knowledge about software quality assurance practices by confirming that 75% of defects found in code reviews affect software evolvability rather than functionality. We also found evidence indicating that context-specific demographics, i.e., role in organization and code ownership, affect evolvability evaluations, but general demographics, i.e., work experience and education, do not","PeriodicalId":101801,"journal":{"name":"2010 IEEE International Conference on Software Maintenance","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123934817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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