Pub Date : 2009-12-31DOI: 10.1109/ICSM.2009.5306384
P. Knab, B. Fluri, H. Gall, M. Pinzger
Issue tracking repositories contain a wealth of information for reasoning about various aspects of software development processes. In this paper, we focus on bug triaging and provide visual means to explore the effort estimation quality and the bug life-cycle of reported problems. Our approach follows the Micro/Macro reading technique and uses a combination of graphical views to investigate details of individual problem reports while maintaining the context provided by the surrounding data population. This enables the detection and detailed analysis of hidden patterns and facilitates the analysis of problem report outliers. In an industrial study, we use our approach in various problem report analysis scenarios and answer questions related to effort estimation and resource planning.
{"title":"Interactive views for analyzing problem reports","authors":"P. Knab, B. Fluri, H. Gall, M. Pinzger","doi":"10.1109/ICSM.2009.5306384","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306384","url":null,"abstract":"Issue tracking repositories contain a wealth of information for reasoning about various aspects of software development processes. In this paper, we focus on bug triaging and provide visual means to explore the effort estimation quality and the bug life-cycle of reported problems. Our approach follows the Micro/Macro reading technique and uses a combination of graphical views to investigate details of individual problem reports while maintaining the context provided by the surrounding data population. This enables the detection and detailed analysis of hidden patterns and facilitates the analysis of problem report outliers. In an industrial study, we use our approach in various problem report analysis scenarios and answer questions related to effort estimation and resource planning.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115167811","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306307
Zude Li, Mechelle Gittens, Syed Shariyar Murtaza, N. Madhavji, A. Miranskyy, David Godwin, Enzo Cialini
Certain software defects require corrective changes repeatedly in a few components of the system. One type of such defects spans multiple components of the system, and we call such defects pervasive multiple-component defects (PMCDs). In this paper, we describe an empirical study of six releases of a large legacy software system (of approx. size 20 million physical lines of code) to analyze PMCDs with respect to: (1) the complexity of fixing such defects and (2) the persistence of defect-prone components across phases and releases. The overall hypothesis in this study is that PMCDs inflict a greater negative impact than do other defects on defect-correction efficacy. Our findings show that the average number of changes required for fixing PMCDs is 20–30 times as much as the average for all defects. Also, over 80% of PMCD-contained defect-prone components still remain defect-prone in successive phases or releases. These findings support the overall hypothesis strongly. We compare our results, where possible, to those of other researchers and discuss the implications on maintenance processes and tools.
{"title":"Analysis of pervasive multiple-component defects in a large software system","authors":"Zude Li, Mechelle Gittens, Syed Shariyar Murtaza, N. Madhavji, A. Miranskyy, David Godwin, Enzo Cialini","doi":"10.1109/ICSM.2009.5306307","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306307","url":null,"abstract":"Certain software defects require corrective changes repeatedly in a few components of the system. One type of such defects spans multiple components of the system, and we call such defects pervasive multiple-component defects (PMCDs). In this paper, we describe an empirical study of six releases of a large legacy software system (of approx. size 20 million physical lines of code) to analyze PMCDs with respect to: (1) the complexity of fixing such defects and (2) the persistence of defect-prone components across phases and releases. The overall hypothesis in this study is that PMCDs inflict a greater negative impact than do other defects on defect-correction efficacy. Our findings show that the average number of changes required for fixing PMCDs is 20–30 times as much as the average for all defects. Also, over 80% of PMCD-contained defect-prone components still remain defect-prone in successive phases or releases. These findings support the overall hypothesis strongly. We compare our results, where possible, to those of other researchers and discuss the implications on maintenance processes and tools.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127168614","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306306
Mark Shtern, Vassilios Tzerpos
The evaluation of the effectiveness of software clustering algorithms is a challenging research question. Several approaches that compare clustering results to an authoritative decomposition have been presented in the literature. Existing evaluation methods typically compress the evaluation results into a single number. They also often disagree with each other for reasons that are not well understood. In this paper, we introduce a novel set of indicators that evaluate structural discrepancies between software decompositions. They also allow researchers to investigate the differences between existing evaluation approaches in a reduced search space. Several experiments with real software systems showcase the usefulness of the introduced indicators.
{"title":"Refining clustering evaluation using structure indicators","authors":"Mark Shtern, Vassilios Tzerpos","doi":"10.1109/ICSM.2009.5306306","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306306","url":null,"abstract":"The evaluation of the effectiveness of software clustering algorithms is a challenging research question. Several approaches that compare clustering results to an authoritative decomposition have been presented in the literature. Existing evaluation methods typically compress the evaluation results into a single number. They also often disagree with each other for reasons that are not well understood. In this paper, we introduce a novel set of indicators that evaluate structural discrepancies between software decompositions. They also allow researchers to investigate the differences between existing evaluation approaches in a reduced search space. Several experiments with real software systems showcase the usefulness of the introduced indicators.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126179873","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306280
Anas Jadallah, M. Galster, M. Moussavi, G. Ruhe
Planning the next release in software release planning addresses the problem of assigning features to the next release such that technical, resource, risk, and budget constraints are met. This paper studies the planning for the next release of an evolving system from a bi-criteria perspective. We introduce a method called NRP-trade-off to adjust baseline release plans for more modifiability by replacing lower value features with features having a higher modifiability. For that purpose, we include a new approach for feature modeling and assessing modifiability by applying object-oriented design metrics to the feature domain. We also briefly introduce a case study.
{"title":"Balancing value and modifiability when planning for the next release","authors":"Anas Jadallah, M. Galster, M. Moussavi, G. Ruhe","doi":"10.1109/ICSM.2009.5306280","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306280","url":null,"abstract":"Planning the next release in software release planning addresses the problem of assigning features to the next release such that technical, resource, risk, and budget constraints are met. This paper studies the planning for the next release of an evolving system from a bi-criteria perspective. We introduce a method called NRP-trade-off to adjust baseline release plans for more modifiability by replacing lower value features with features having a higher modifiability. For that purpose, we include a new approach for feature modeling and assessing modifiability by applying object-oriented design metrics to the feature domain. We also briefly introduce a case study.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122214971","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306312
J. Geet, S. Demeyer
Over the last decade, numerous techniques have been proposed in the literature to reverse engineer large legacy systems, several of them even claiming success on industrial scale. Consequently, when faced with a reverse engineering request from a large banking company, we decided to reuse an existing technique (namely, feature location using formal concept analysis on execution profiles) and see whether we could replicate their results. This paper reports our experience with such a replication experiment: we list those things that worked well (and fortunately, there were quite a few) and those things that did not work so well (and try to identify root causes and solutions for the problems we encountered).
{"title":"Feature location in COBOL mainframe systems: An experience report","authors":"J. Geet, S. Demeyer","doi":"10.1109/ICSM.2009.5306312","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306312","url":null,"abstract":"Over the last decade, numerous techniques have been proposed in the literature to reverse engineer large legacy systems, several of them even claiming success on industrial scale. Consequently, when faced with a reverse engineering request from a large banking company, we decided to reuse an existing technique (namely, feature location using formal concept analysis on execution profiles) and see whether we could replicate their results. This paper reports our experience with such a replication experiment: we list those things that worked well (and fortunately, there were quite a few) and those things that did not work so well (and try to identify root causes and solutions for the problems we encountered).","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116846487","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306282
N. Yoo
In this paper, the performance impact analysis of e-government systems with key performance parameters is being considered. Meaningful impact analysis in sustained government systems is required for considering non-functional requirements and functional requirements. Performance requirements are a critical component of non-functional areas. For example, if a new system change is set to the system, the impact in terms of the response time must be implemented in each sub-system. In this paper, an XML-based framework can be used to analyze performance impacts on sub-systems and can provide a scheme to enhance impact analysis by performance monitoring using application response measurement. Through a health system example as a case study, a performance requirement model to describe extended trees and adapting analysis result of performance monitoring using application response measurement and XML tree representation are addressed. This paper also proposes a scheme for prioritized processing and an algorithm for effectively enhancing impact analysis in a timely fashion.
{"title":"Performance impact analysis with KPP using application response measurement in E-government systems","authors":"N. Yoo","doi":"10.1109/ICSM.2009.5306282","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306282","url":null,"abstract":"In this paper, the performance impact analysis of e-government systems with key performance parameters is being considered. Meaningful impact analysis in sustained government systems is required for considering non-functional requirements and functional requirements. Performance requirements are a critical component of non-functional areas. For example, if a new system change is set to the system, the impact in terms of the response time must be implemented in each sub-system. In this paper, an XML-based framework can be used to analyze performance impacts on sub-systems and can provide a scheme to enhance impact analysis by performance monitoring using application response measurement. Through a health system example as a case study, a performance requirement model to describe extended trees and adapting analysis result of performance monitoring using application response measurement and XML tree representation are addressed. This paper also proposes a scheme for prioritized processing and an algorithm for effectively enhancing impact analysis in a timely fashion.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129792881","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306346
José Pedro Correia, Y. Kanellopoulos, Joost Visser
The ISO/IEC 9126 international standard for software product quality is a widely accepted reference for terminology regarding the multi-faceted concept of software product quality. Based on this standard, the Software Improvement Group has developed a pragmatic approach for measuring technical quality of software products. This quality model introduces another level below the hierarchy defined by ISO/IEC 9126, which consists of system properties such as volume, duplication, unit complexity and others. A mapping between system properties and ISO/IEC 9126 characteristics is defined in a binary fashion: a property either influences a characteristic or not. This mapping embodies consensus among three experts based, in an informal way, on their experience in software quality assessment. We have conducted a survey-based experiment to study the mapping between system properties and quality characteristics. We used the Analytic Hierarchy Process as a formally structured method to elicit the relative importance of system properties and quality characteristics from a group of 22 software quality experts. We analyzed the results of the experiment with two objectives: (i) to validate the original binary mapping and (ii) to refine the mapping using the elicited relative weights.
{"title":"A survey-based study of the mapping of system properties to ISO/IEC 9126 maintainability characteristics","authors":"José Pedro Correia, Y. Kanellopoulos, Joost Visser","doi":"10.1109/ICSM.2009.5306346","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306346","url":null,"abstract":"The ISO/IEC 9126 international standard for software product quality is a widely accepted reference for terminology regarding the multi-faceted concept of software product quality. Based on this standard, the Software Improvement Group has developed a pragmatic approach for measuring technical quality of software products. This quality model introduces another level below the hierarchy defined by ISO/IEC 9126, which consists of system properties such as volume, duplication, unit complexity and others. A mapping between system properties and ISO/IEC 9126 characteristics is defined in a binary fashion: a property either influences a characteristic or not. This mapping embodies consensus among three experts based, in an informal way, on their experience in software quality assessment. We have conducted a survey-based experiment to study the mapping between system properties and quality characteristics. We used the Analytic Hierarchy Process as a formally structured method to elicit the relative importance of system properties and quality characteristics from a group of 22 software quality experts. We analyzed the results of the experiment with two objectives: (i) to validate the original binary mapping and (ii) to refine the mapping using the elicited relative weights.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"31 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123654303","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306290
Yi Wang
Refactoring is an increasingly practiced method in industry software development. However, existing research mostly focus on the technical aspect of refactoring, we still know little about the human behavior domain on this issue. Software developer's motivation has been recognized as a key human factor for the software development and maintenance tasks, therefore, identifying what motivates software developer refactor their (or others) source code will bring both theoretical and practical implications. In this paper, we report our case studies in four software development organizations. Through interviews with 10 professional software developers, we identified the major factors that motivate their refactoring activities. An empirical model on refactoring motivation is also presented based on the data collected.
{"title":"What motivate software engineers to refactor source code? evidences from professional developers","authors":"Yi Wang","doi":"10.1109/ICSM.2009.5306290","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306290","url":null,"abstract":"Refactoring is an increasingly practiced method in industry software development. However, existing research mostly focus on the technical aspect of refactoring, we still know little about the human behavior domain on this issue. Software developer's motivation has been recognized as a key human factor for the software development and maintenance tasks, therefore, identifying what motivates software developer refactor their (or others) source code will bring both theoretical and practical implications. In this paper, we report our case studies in four software development organizations. Through interviews with 10 professional software developers, we identified the major factors that motivate their refactoring activities. An empirical model on refactoring motivation is also presented based on the data collected.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124166555","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306305
Penelope A. Brooks, A. Memon
Most of today's event driven software (EDS) systems are tested using test cases that are carefully constructed as sequences of events; they test the execution of an event in the context of its preceding events. Because sizes of these test suites can be extremely large, researchers have developed techniques, such as reduction and minimization, to obtain test suites that are “similar” to the original test suite, but smaller. Existing similarity metrics mostly use code coverage; they do not consider the contextual relationships between events. Consequently, reduction based on such metrics may eliminate desirable test cases. In this paper, we present a new parameterized metric, CONTeSSi(n) which uses the context of n preceding events in test cases to develop a new context-aware notion of test suite similarity for EDS. This metric is defined and evaluated by comparing four test suites for each of four open source applications. Our results show that CONT eSSi(n) is a better indicator of the similarity of EDS test suites than existing metrics.
{"title":"Introducing a test suite similarity metric for event sequence-based test cases","authors":"Penelope A. Brooks, A. Memon","doi":"10.1109/ICSM.2009.5306305","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306305","url":null,"abstract":"Most of today's event driven software (EDS) systems are tested using test cases that are carefully constructed as sequences of events; they test the execution of an event in the context of its preceding events. Because sizes of these test suites can be extremely large, researchers have developed techniques, such as reduction and minimization, to obtain test suites that are “similar” to the original test suite, but smaller. Existing similarity metrics mostly use code coverage; they do not consider the contextual relationships between events. Consequently, reduction based on such metrics may eliminate desirable test cases. In this paper, we present a new parameterized metric, CONTeSSi(n) which uses the context of n preceding events in test cases to develop a new context-aware notion of test suite similarity for EDS. This metric is defined and evaluated by comparing four test suites for each of four open source applications. Our results show that CONT eSSi(n) is a better indicator of the similarity of EDS test suites than existing metrics.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127604025","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 : 2009-10-30DOI: 10.1109/ICSM.2009.5306313
Omar Alam, Bram Adams, A. Hassan
Tracking the progress of a project is often done through imprecise manually gathered information, like progress reports, or through automatic metrics such as Lines Of Code (LOC). Such metrics are too coarse-grained and too imprecise to capture all facets of a project. In this paper, we mine the code changes in the source code repository and study the concept of time dependence of code changes. Using this concept, we can track the progress of a software project as the progress of a building. We can examine how changes build on each other over time and determine the impact of these changes on the quality of a project. In particular, we study whether new changes are built just-in-time or if they build on older, stable code. Through a case study on two large open source projects (PostgreSQL and FreeBSD), we show that time dependence varies across projects and throughout the lifetime of each project. We also show that there is a high linear correlation between building on new code and the occurrence of bugs.
跟踪项目的进度通常是通过不精确的人工收集的信息来完成的，比如进度报告，或者通过自动度量，比如代码行(Lines of Code, LOC)。这样的量度过于粗粒度和不精确，无法捕获项目的所有方面。本文对源代码库中的代码变更进行了挖掘，并研究了代码变更的时间依赖性概念。使用这个概念，我们可以像跟踪建筑的进度一样跟踪软件项目的进度。我们可以检查变更是如何随着时间的推移相互建立的，并确定这些变更对项目质量的影响。特别是，我们研究新的变更是否及时构建，或者是否构建在较旧的、稳定的代码上。通过对两个大型开源项目(PostgreSQL和FreeBSD)的案例研究，我们展示了时间依赖性在不同的项目和每个项目的整个生命周期中是不同的。我们还展示了在新代码上构建和bug发生之间存在高度的线性相关性。
{"title":"Measuring the progress of projects using the time dependence of code changes","authors":"Omar Alam, Bram Adams, A. Hassan","doi":"10.1109/ICSM.2009.5306313","DOIUrl":"https://doi.org/10.1109/ICSM.2009.5306313","url":null,"abstract":"Tracking the progress of a project is often done through imprecise manually gathered information, like progress reports, or through automatic metrics such as Lines Of Code (LOC). Such metrics are too coarse-grained and too imprecise to capture all facets of a project. In this paper, we mine the code changes in the source code repository and study the concept of time dependence of code changes. Using this concept, we can track the progress of a software project as the progress of a building. We can examine how changes build on each other over time and determine the impact of these changes on the quality of a project. In particular, we study whether new changes are built just-in-time or if they build on older, stable code. Through a case study on two large open source projects (PostgreSQL and FreeBSD), we show that time dependence varies across projects and throughout the lifetime of each project. We also show that there is a high linear correlation between building on new code and the occurrence of bugs.","PeriodicalId":247441,"journal":{"name":"2009 IEEE International Conference on Software Maintenance","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132640482","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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