Pub Date : 2003-10-06DOI: 10.1109/ASE.2003.1240319
Christopher J. Turner, T. Graham, Christopher Wolfe, Julian Ball, David Holman, Hugh D. Stewart, A. Ryman
This paper presents visual constraint diagrams (VCD), an extension to UML (Unified Modeling Language) object diagrams for expressing constraints over object models. VCD allows designers to express well-formedness constraints that cannot be expressed using class diagrams alone; an example of such a constraint is that a linked list data structure cannot have any loops. VCD offers two advances over existing techniques: (1) they allow constraints to be expressed within the visual notation of UML, without resorting to complex textual notations such as OCL; and (2) VCD can be checked at runtime, increasing the value of design documents to developers. An editor and a checker for VCD have been implemented as part of the Rosetta software design tool.
{"title":"Visual constraint diagrams: runtime conformance checking of UML object models versus implementations","authors":"Christopher J. Turner, T. Graham, Christopher Wolfe, Julian Ball, David Holman, Hugh D. Stewart, A. Ryman","doi":"10.1109/ASE.2003.1240319","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240319","url":null,"abstract":"This paper presents visual constraint diagrams (VCD), an extension to UML (Unified Modeling Language) object diagrams for expressing constraints over object models. VCD allows designers to express well-formedness constraints that cannot be expressed using class diagrams alone; an example of such a constraint is that a linked list data structure cannot have any loops. VCD offers two advances over existing techniques: (1) they allow constraints to be expressed within the visual notation of UML, without resorting to complex textual notations such as OCL; and (2) VCD can be checked at runtime, increasing the value of design documents to developers. An editor and a checker for VCD have been implemented as part of the Rosetta software design tool.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114696541","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240310
M. Robillard, G. Murphy
When performing a program evolution task, developers typically spend a significant amount of effort investigating and reinvestigating source code. To reduce this effort, we propose a technique to automatically infer the essence of program investigation activities as a set of concern descriptions. The concern descriptions produced by our technique list methods and fields of importance in the context of the investigation of an object-oriented system. A developer can rely on this information to perform the change task at hand, or at a later stage for a change that involves the same concerns. The technique involves applying an algorithm to a transcript of a program investigation session. The transcript lists which pieces of source code were accessed by a developer when investigating a program and how the different pieces of code were accessed. We applied the technique to data obtained from program investigation activities for five subjects involved in two different program evolution tasks. The results show that relevant concerns can be identified with a manageable level of noise.
{"title":"Automatically inferring concern code from program investigation activities","authors":"M. Robillard, G. Murphy","doi":"10.1109/ASE.2003.1240310","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240310","url":null,"abstract":"When performing a program evolution task, developers typically spend a significant amount of effort investigating and reinvestigating source code. To reduce this effort, we propose a technique to automatically infer the essence of program investigation activities as a set of concern descriptions. The concern descriptions produced by our technique list methods and fields of importance in the context of the investigation of an object-oriented system. A developer can rely on this information to perform the change task at hand, or at a later stage for a change that involves the same concerns. The technique involves applying an algorithm to a transcript of a program investigation session. The transcript lists which pieces of source code were accessed by a developer when investigating a program and how the different pieces of code were accessed. We applied the technique to data obtained from program investigation activities for five subjects involved in two different program evolution tasks. The results show that relevant concerns can be identified with a manageable level of noise.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122271458","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240296
C. Consel, Laurent Réveillère
The client-server model has been successfully used to support a wide variety of families of services in the context of distributed systems. However, its server-centric nature makes it insensitive to fast changing client characteristics like terminal capabilities, network features, user preferences and evolving needs. To overcome these key limitations, we present an approach to enabling a server to adapt to different clients by making it programmable. A service-description language is used to program server adaptations. This language is designed as a domain-specific language to offer expressiveness and conciseness without compromising safety and security. We show that requiring the deployment of new protocols or server implementations. We illustrate our approach with the Internet Message Access Protocol (IMAP). An IMAP server is made programmable and a language, named Pems, is introduced to program robust variations of e-mail services. Our approach is uniformly used to develop a platform for multimedia communication services. This platform is composed of programmable servers for telephony service, e-mail processing, remote-document processing and stream adapters.
{"title":"A programmable client-server model: robust extensibility via DSLs","authors":"C. Consel, Laurent Réveillère","doi":"10.1109/ASE.2003.1240296","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240296","url":null,"abstract":"The client-server model has been successfully used to support a wide variety of families of services in the context of distributed systems. However, its server-centric nature makes it insensitive to fast changing client characteristics like terminal capabilities, network features, user preferences and evolving needs. To overcome these key limitations, we present an approach to enabling a server to adapt to different clients by making it programmable. A service-description language is used to program server adaptations. This language is designed as a domain-specific language to offer expressiveness and conciseness without compromising safety and security. We show that requiring the deployment of new protocols or server implementations. We illustrate our approach with the Internet Message Access Protocol (IMAP). An IMAP server is made programmable and a language, named Pems, is introduced to program robust variations of e-mail services. Our approach is uniformly used to develop a platform for multimedia communication services. This platform is composed of programmable servers for telephony service, e-mail processing, remote-document processing and stream adapters.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129911624","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240303
H. Foster, Sebastián Uchitel, J. Magee, J. Kramer
In this paper, we discuss a model-based approach to verifying Web service compositions for Web service implementations. The approach supports verification against specification models and assigns semantics to the behavior of implementation model so as to confirm expected results for both the designer and implementer. Specifications of the design are modeled in UML (Unified Modeling Language), in the form of message sequence charts (MSC), and mechanically compiled into the finite state process notation (FSP) to concisely describe and reason about the concurrent programs. Implementations are mechanically translated to FSP to allow a trace equivalence verification process to be performed. By providing early design verification, the implementation, testing, and deployment of Web service compositions can be eased through the understanding of the differences, limitations and undesirable traces allowed by the composition. The approach is supported by a suite of cooperating tools for specification, formal modeling and trace animation of the composition workflow.
{"title":"Model-based verification of Web service compositions","authors":"H. Foster, Sebastián Uchitel, J. Magee, J. Kramer","doi":"10.1109/ASE.2003.1240303","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240303","url":null,"abstract":"In this paper, we discuss a model-based approach to verifying Web service compositions for Web service implementations. The approach supports verification against specification models and assigns semantics to the behavior of implementation model so as to confirm expected results for both the designer and implementer. Specifications of the design are modeled in UML (Unified Modeling Language), in the form of message sequence charts (MSC), and mechanically compiled into the finite state process notation (FSP) to concisely describe and reason about the concurrent programs. Implementations are mechanically translated to FSP to allow a trace equivalence verification process to be performed. By providing early design verification, the implementation, testing, and deployment of Web service compositions can be eased through the understanding of the differences, limitations and undesirable traces allowed by the composition. The approach is supported by a suite of cooperating tools for specification, formal modeling and trace animation of the composition workflow.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133204272","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240301
E. Tilevich, Stephan Urbanski, Y. Smaragdakis, M. Fleury
We discuss how a collection of domain-specific and domain-independent tools can be combined to "aspectize" the distributed character of server-side applications, to a much greater extent than with prior efforts. Specifically, we present a framework that can be used with a large class of unaware applications to turn their objects into distributed objects with minimal programming effort. Our framework is developed on top of three main components: AspectJ (a high-level aspect language), XDoclet (a low-level aspect language), and NRMI (a middleware facility that makes remote calls behave more like local calls). We discuss why each of the three components offers unique advantages and is necessary for an elegant solution, why our approach is general, and how it constitutes a significant improvement over past efforts to isolate distribution concerns.
{"title":"Aspectizing server-side distribution","authors":"E. Tilevich, Stephan Urbanski, Y. Smaragdakis, M. Fleury","doi":"10.1109/ASE.2003.1240301","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240301","url":null,"abstract":"We discuss how a collection of domain-specific and domain-independent tools can be combined to \"aspectize\" the distributed character of server-side applications, to a much greater extent than with prior efforts. Specifically, we present a framework that can be used with a large class of unaware applications to turn their objects into distributed objects with minimal programming effort. Our framework is developed on top of three main components: AspectJ (a high-level aspect language), XDoclet (a low-level aspect language), and NRMI (a middleware facility that makes remote calls behave more like local calls). We discuss why each of the three components offers unique advantages and is necessary for an elegant solution, why our approach is general, and how it constitutes a significant improvement over past efforts to isolate distribution concerns.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124922081","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240304
A. Memon, Ishan Banerjee, Adithya Nagarajan
Test designers widely believe that the overall effectiveness and cost of software testing depends largely on the type and number of test cases executed on the software. In this paper we show that the test oracle used during testing also contributes significantly to test effectiveness and cost. A test oracle is a mechanism that determines whether software executed correctly for a test case. We define a test oracle to contain two essential parts: oracle information that represents expected output; and an oracle procedure that compares the oracle information with the actual output. By varying the level of detail of oracle information and changing the oracle procedure, a test designer can create different types of test oracles. We design 11 types of test oracles and empirically compare them on four software systems. We seed faults in software to create 100 faulty versions, execute 600 test cases on each version, for all 11 types of oracles. In all, we report results of 660,000 test runs on software. We show (1) the time and space requirements of the oracles, (2) that faults are detected early in the testing process when using detailed oracle information and complex oracle procedures, although at a higher cost per test case, and (3) that employing expensive oracles results in detecting a large number of faults using relatively smaller number of test cases.
{"title":"What test oracle should I use for effective GUI testing?","authors":"A. Memon, Ishan Banerjee, Adithya Nagarajan","doi":"10.1109/ASE.2003.1240304","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240304","url":null,"abstract":"Test designers widely believe that the overall effectiveness and cost of software testing depends largely on the type and number of test cases executed on the software. In this paper we show that the test oracle used during testing also contributes significantly to test effectiveness and cost. A test oracle is a mechanism that determines whether software executed correctly for a test case. We define a test oracle to contain two essential parts: oracle information that represents expected output; and an oracle procedure that compares the oracle information with the actual output. By varying the level of detail of oracle information and changing the oracle procedure, a test designer can create different types of test oracles. We design 11 types of test oracles and empirically compare them on four software systems. We seed faults in software to create 100 faulty versions, execute 600 test cases on each version, for all 11 types of oracles. In all, we report results of 660,000 test runs on software. We show (1) the time and space requirements of the oracles, (2) that faults are detected early in the testing process when using detailed oracle information and complex oracle procedures, although at a higher cost per test case, and (3) that employing expensive oracles results in detecting a large number of faults using relatively smaller number of test cases.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129692581","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240290
M. Sabetzadeh, S. Easterbrook
Eliciting the requirements for a proposed system typically involves different stakeholders with different expertise, responsibilities, and perspectives. Viewpoints-based approaches have been proposed as a way to manage incomplete and inconsistent models gathered from multiple sources. In this paper, we propose a category-theoretical framework for the analysis of fuzzy viewpoints. Informally, a fuzzy viewpoint is graph in which the elements of a lattice are used to specify the amount of knowledge available about the details of nodes and edges. By defining an appropriate notion of morphism between fuzzy viewpoints, we construct categories of fuzzy viewpoints and prove that these categories are (finitely) complete. We then show how colimits can be employed to merge the viewpoints and detect the inconsistencies that arise independent of any particular choice of viewpoint semantics. We illustrate an application of the framework through a case-study showing how fuzzy viewpoints can serve as a requirements elicitation tool in reactive systems.
{"title":"Analysis of inconsistency in graph-based viewpoints: a category-theoretical approach","authors":"M. Sabetzadeh, S. Easterbrook","doi":"10.1109/ASE.2003.1240290","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240290","url":null,"abstract":"Eliciting the requirements for a proposed system typically involves different stakeholders with different expertise, responsibilities, and perspectives. Viewpoints-based approaches have been proposed as a way to manage incomplete and inconsistent models gathered from multiple sources. In this paper, we propose a category-theoretical framework for the analysis of fuzzy viewpoints. Informally, a fuzzy viewpoint is graph in which the elements of a lattice are used to specify the amount of knowledge available about the details of nodes and edges. By defining an appropriate notion of morphism between fuzzy viewpoints, we construct categories of fuzzy viewpoints and prove that these categories are (finitely) complete. We then show how colimits can be employed to merge the viewpoints and detect the inconsistencies that arise independent of any particular choice of viewpoint semantics. We illustrate an application of the framework through a case-study showing how fuzzy viewpoints can serve as a requirements elicitation tool in reactive systems.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128321161","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240321
Daniel R. Licata, C. D. Harris, S. Krishnamurthi
As programs evolve, their code increasingly becomes tangled by programmers and requirements. This mosaic quality complicated program comprehension and maintenance. Many of these activities can benefit from viewing the program as a collection of features. We introduce an inexpensive and easily comprehensible summary of program changes called the feature signature and investigate its properties. We find a remarkable similarity in the nature of feature signatures across multiple nontrivial programs, developers and magnitude changes. This indicates that feature signatures are a meaningful notion worth studying. We then show numerous applications of feature signatures to software evolution, establishing their utility.
{"title":"The feature signatures of evolving programs","authors":"Daniel R. Licata, C. D. Harris, S. Krishnamurthi","doi":"10.1109/ASE.2003.1240321","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240321","url":null,"abstract":"As programs evolve, their code increasingly becomes tangled by programmers and requirements. This mosaic quality complicated program comprehension and maintenance. Many of these activities can benefit from viewing the program as a collection of features. We introduce an inexpensive and easily comprehensible summary of program changes called the feature signature and investigate its properties. We find a remarkable similarity in the nature of feature signatures across multiple nontrivial programs, developers and magnitude changes. This indicates that feature signatures are a meaningful notion worth studying. We then show numerous applications of feature signatures to software evolution, establishing their utility.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130679381","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240317
C. Nebut, S. Pickin, Yves Le Traon, J. Jézéquel
Software product families (PF) are becoming one of the key challenges of software engineering. Despite recent interest in this area, the extent to which the close relationship between PF and requirements engineering is exploited to guide the V&V tasks is still limited. In particular, PF processes generally lack support for generating test cases from requirements. In this paper, we propose a requirements-based approach to functional testing of product lines, based on a formal test generation tool. Here, we outline how product-specific test cases can be automatically generated from PF functional requirements expressed in UML (Unified Modeling Language). We study the efficiency of the generated test cases on a case study.
{"title":"Automated requirements-based generation of test cases for product families","authors":"C. Nebut, S. Pickin, Yves Le Traon, J. Jézéquel","doi":"10.1109/ASE.2003.1240317","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240317","url":null,"abstract":"Software product families (PF) are becoming one of the key challenges of software engineering. Despite recent interest in this area, the extent to which the close relationship between PF and requirements engineering is exploited to guide the V&V tasks is still limited. In particular, PF processes generally lack support for generating test cases from requirements. In this paper, we propose a requirements-based approach to functional testing of product lines, based on a formal test generation tool. Here, we outline how product-specific test cases can be automatically generated from PF functional requirements expressed in UML (Unified Modeling Language). We study the efficiency of the generated test cases on a case study.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131910591","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 : 2003-10-06DOI: 10.1109/ASE.2003.1240328
Yunja Choi, M. Heimdahl
As an automated verification and validation tool, model checking can be quite effective in practice. Nevertheless, model checking has been quite inefficient when dealing with systems with data variables over a large (or infinite) domain, which is a serious limiting factor for its applicability in practice. To address this issue, we have investigated a static abstraction technique, domain reduction abstraction, based on data equivalence and trajectory reduction, and implemented it as a prototype extension of the symbolic model checker NuSMV. Unlike on-the-fly dynamic abstraction techniques, domain reduction abstraction statically analyzes specifications and automatically produces an abstract model which can be reused over time; a feature suitable for regression verification.
{"title":"Model checking software requirement specifications using domain reduction abstraction","authors":"Yunja Choi, M. Heimdahl","doi":"10.1109/ASE.2003.1240328","DOIUrl":"https://doi.org/10.1109/ASE.2003.1240328","url":null,"abstract":"As an automated verification and validation tool, model checking can be quite effective in practice. Nevertheless, model checking has been quite inefficient when dealing with systems with data variables over a large (or infinite) domain, which is a serious limiting factor for its applicability in practice. To address this issue, we have investigated a static abstraction technique, domain reduction abstraction, based on data equivalence and trajectory reduction, and implemented it as a prototype extension of the symbolic model checker NuSMV. Unlike on-the-fly dynamic abstraction techniques, domain reduction abstraction statically analyzes specifications and automatically produces an abstract model which can be reused over time; a feature suitable for regression verification.","PeriodicalId":114604,"journal":{"name":"18th IEEE International Conference on Automated Software Engineering, 2003. Proceedings.","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131414629","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：