The increasing adoption of smartphones and tablets has provided tens of millions of users with substantial resources for computation, communication and sensing. The availability of these resources has a huge potential to positively transform our society and empower individuals. Unfortunately, although the number of users has increased dramatically, the number of developers is still limited by the high barrier that existing programming environments impose. To understand possible directions for helping end users to program, we present Pong Designer, an environment for developing 2D physics games through direct manipulation of object behaviors. Pong Designer is built using Scala and runs on Android tablets with the multi-touch screen as the main input. We show that Pong Designer can create simple games in a few steps. This includes (multi-player and multi-screen) Pong, Brick Breaker, Pacman, Tilting maze. We make available Pong Designer as well as several editable games that we created using it. This paper describes the main principles behind Pong Designer, and illustrates the process of developing and customizing behavior in this approach
{"title":"Game programming by demonstration","authors":"M. Mayer, Viktor Kunčak","doi":"10.1145/2509578.2509583","DOIUrl":"https://doi.org/10.1145/2509578.2509583","url":null,"abstract":"The increasing adoption of smartphones and tablets has provided tens of millions of users with substantial resources for computation, communication and sensing. The availability of these resources has a huge potential to positively transform our society and empower individuals. Unfortunately, although the number of users has increased dramatically, the number of developers is still limited by the high barrier that existing programming environments impose.\u0000 To understand possible directions for helping end users to program, we present Pong Designer, an environment for developing 2D physics games through direct manipulation of object behaviors. Pong Designer is built using Scala and runs on Android tablets with the multi-touch screen as the main input. We show that Pong Designer can create simple games in a few steps. This includes (multi-player and multi-screen) Pong, Brick Breaker, Pacman, Tilting maze. We make available Pong Designer as well as several editable games that we created using it. This paper describes the main principles behind Pong Designer, and illustrates the process of developing and customizing behavior in this approach","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129174995","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}
The theory and semantics of programming languages are typically formulated using abstract mathematical models that have no obvious connection to any physical theory. While this approach has a number of advantages, it does not generalize to complex nondiscrete systems, and it obscures the underlying mathematical connections between computational and physical theory. Moreover, it can lead to inaccurate models of more complex phenomena such as concurrency. In this paper, we describe the current directions and initial results of our efforts to build connections between programming language theory and semantics and physical theory. The first and most mature of these efforts aims to develop a denotational semantic model that expands upon the mathematical formulation of quantum systems to provide a denotational foundation for concurrent languages. The second effort aims to generalize the notion of type systems to a probability inference system based on Bayesian probability. The third and final effort aims to develop an understanding of the dynamics of concurrent processes, with the goal of reasoning about the real behavior of processes in greater detail. In each of these efforts, we aim to draw connections between computing and other scientific disciplines.
{"title":"Building connections between theories of computing and physical systems","authors":"Eric L. McCorkle","doi":"10.1145/2509578.2509587","DOIUrl":"https://doi.org/10.1145/2509578.2509587","url":null,"abstract":"The theory and semantics of programming languages are typically formulated using abstract mathematical models that have no obvious connection to any physical theory. While this approach has a number of advantages, it does not generalize to complex nondiscrete systems, and it obscures the underlying mathematical connections between computational and physical theory. Moreover, it can lead to inaccurate models of more complex phenomena such as concurrency. In this paper, we describe the current directions and initial results of our efforts to build connections between programming language theory and semantics and physical theory. The first and most mature of these efforts aims to develop a denotational semantic model that expands upon the mathematical formulation of quantum systems to provide a denotational foundation for concurrent languages. The second effort aims to generalize the notion of type systems to a probability inference system based on Bayesian probability. The third and final effort aims to develop an understanding of the dynamics of concurrent processes, with the goal of reasoning about the real behavior of processes in greater detail. In each of these efforts, we aim to draw connections between computing and other scientific disciplines.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122524210","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}
In object-oriented programs, the relationship of an object to many objects is usually implemented using a collection. This is in contrast to a relationship to one object, which is usually realized as a direct value. However, using collections for relationships to many objects does not only mean that accessing the related objects always requires accessing the collection first, it also presents a lurking maintenance problem that manifests itself when a relationship needs to be changed from to-one to to-many or vice versa. To address these issues, we suggest the extension of object-oriented programming with multiplicities, that is, with expressions that evaluate to an arbitrary number of objects not wrapped in a container.
{"title":"Content over container: object-oriented programming with multiplicities","authors":"F. Steimann","doi":"10.1145/2509578.2509582","DOIUrl":"https://doi.org/10.1145/2509578.2509582","url":null,"abstract":"In object-oriented programs, the relationship of an object to many objects is usually implemented using a collection. This is in contrast to a relationship to one object, which is usually realized as a direct value. However, using collections for relationships to many objects does not only mean that accessing the related objects always requires accessing the collection first, it also presents a lurking maintenance problem that manifests itself when a relationship needs to be changed from to-one to to-many or vice versa. To address these issues, we suggest the extension of object-oriented programming with multiplicities, that is, with expressions that evaluate to an arbitrary number of objects not wrapped in a container.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132530254","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}
Our powerful computers help very little in debugging the program we have so we can change it into the program we want. We introduce Conversational Programming as a way to harness our computing power to inspect program meaning through a combination of partial program execution and semantic program annotation. A programmer in our approach interactively selects highly autonomous "agents" in a program world as conversation topics and then changes the world to explore the potential behaviors of a selected agent in different scenarios. In this way, the programmer proactively knows how their code affects program execution as they explore various contexts. This paper describes conversational programming through design principles and use cases.
{"title":"Conversational programming: exploring interactive program analysis","authors":"A. Repenning","doi":"10.1145/2509578.2509591","DOIUrl":"https://doi.org/10.1145/2509578.2509591","url":null,"abstract":"Our powerful computers help very little in debugging the program we have so we can change it into the program we want. We introduce Conversational Programming as a way to harness our computing power to inspect program meaning through a combination of partial program execution and semantic program annotation. A programmer in our approach interactively selects highly autonomous \"agents\" in a program world as conversation topics and then changes the world to explore the potential behaviors of a selected agent in different scenarios. In this way, the programmer proactively knows how their code affects program execution as they explore various contexts. This paper describes conversational programming through design principles and use cases.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"296 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132691531","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}
Programming today involves code editing mixed with bouts of debugging to get feedback on code execution. For programming to be more fluid, editing and debugging should occur concurrently as live programming. This paper describes how live execution feedback can be woven into the editor by making places in program execution, not just code, navigable so that evaluation results can be probed directly within the code editor. A pane aside the editor also traces execution with entries that are similarly navigable, enabling quick problem diagnosis. Both probes and traces are refreshed continuously during editing, and are easily configured based on debugging needs. We demonstrate the usefulness of this live programming experience with a prototype.
{"title":"Usable live programming","authors":"Sean McDirmid","doi":"10.1145/2509578.2509585","DOIUrl":"https://doi.org/10.1145/2509578.2509585","url":null,"abstract":"Programming today involves code editing mixed with bouts of debugging to get feedback on code execution. For programming to be more fluid, editing and debugging should occur concurrently as live programming. This paper describes how live execution feedback can be woven into the editor by making places in program execution, not just code, navigable so that evaluation results can be probed directly within the code editor. A pane aside the editor also traces execution with entries that are similarly navigable, enabling quick problem diagnosis. Both probes and traces are refreshed continuously during editing, and are easily configured based on debugging needs. We demonstrate the usefulness of this live programming experience with a prototype.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"287 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114349797","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}
We report on a language called KScript and a GUI framework called KSWorld. The goal of KScript and KSWorld is to try to reduce the accidental complexity in GUI framework code and application building. We aim for an understandable, concise way to specify an application's behavior and appearance, minimizing extra details that arise only because of the medium being used. KScript is a dynamic language based on the declarative and time-aware dataflow-style execution model of Functional Reactive Programming (FRP), extended with support for loose coupling among program elements and a high degree of program reconfigurability. KSWorld is built using KScript. The fields, or slots, of graphical widgets in KSWorld are reactive variables. Definitions of such variables can be added or modified in a localized manner, allowing on-the-fly customization of the visual and behavioral aspects of widgets and entire applications. Thus the KSWorld environment supports exploratory application building: a user constructs the appearance interactively with direct manipulation, then attaches and refines reactive variable definitions to achieve the desired overall behavior. We illustrate our use of KSWorld to build an editor for general graphical documents, including dynamic documents that serve as active essays. The graphical building blocks for documents are the same as those used for building the editor itself, enabling a bootstrapping process in which the earliest working version of the editor can be used to create further components for its own interface. As one way of measuring progress on our complexity goal, we provide an overview of the number of lines of code in KSWorld. The total for the KScript compiler, the FRP evaluator, the framework, document model and document editor is currently around 10,000 lines.
{"title":"KScript and KSWorld: a time-aware and mostly declarative language and interactive GUI framework","authors":"Y. Ohshima, A. Lunzer, B. Freudenberg, T. Kaehler","doi":"10.1145/2509578.2509590","DOIUrl":"https://doi.org/10.1145/2509578.2509590","url":null,"abstract":"We report on a language called KScript and a GUI framework called KSWorld. The goal of KScript and KSWorld is to try to reduce the accidental complexity in GUI framework code and application building. We aim for an understandable, concise way to specify an application's behavior and appearance, minimizing extra details that arise only because of the medium being used.\u0000 KScript is a dynamic language based on the declarative and time-aware dataflow-style execution model of Functional Reactive Programming (FRP), extended with support for loose coupling among program elements and a high degree of program reconfigurability.\u0000 KSWorld is built using KScript. The fields, or slots, of graphical widgets in KSWorld are reactive variables. Definitions of such variables can be added or modified in a localized manner, allowing on-the-fly customization of the visual and behavioral aspects of widgets and entire applications. Thus the KSWorld environment supports exploratory application building: a user constructs the appearance interactively with direct manipulation, then attaches and refines reactive variable definitions to achieve the desired overall behavior.\u0000 We illustrate our use of KSWorld to build an editor for general graphical documents, including dynamic documents that serve as active essays. The graphical building blocks for documents are the same as those used for building the editor itself, enabling a bootstrapping process in which the earliest working version of the editor can be used to create further components for its own interface.\u0000 As one way of measuring progress on our complexity goal, we provide an overview of the number of lines of code in KSWorld. The total for the KScript compiler, the FRP evaluator, the framework, document model and document editor is currently around 10,000 lines.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"70 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131462414","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}
Three years ago in this venue, Cook argued that in their essence, objects are what Reynolds called procedural data structures. His observation raises a natural question: if procedural data structures are the essence of objects, has this contributed to the empirical success of objects, and if so, how? This essay attempts to answer that question. After reviewing Cook's definition, I propose the term service abstractions to capture the essential nature of objects. This terminology emphasizes, following Kay, that objects are not primarily about representing and manipulating data, but are more about providing services in support of higher-level goals. Using examples taken from object-oriented frameworks, I illustrate the unique design leverage that service abstractions provide: the ability to define abstractions that can be extended, and whose extensions are interoperable in a first-class way. The essay argues that the form of interoperable extension supported by service abstractions is essential to modern software: many modern frameworks and ecosystems could not have been built without service abstractions. In this sense, the success of objects was not a coincidence: it was an inevitable consequence of their service abstraction nature.
{"title":"The power of interoperability: why objects are inevitable","authors":"Jonathan Aldrich","doi":"10.1145/2509578.2514738","DOIUrl":"https://doi.org/10.1145/2509578.2514738","url":null,"abstract":"Three years ago in this venue, Cook argued that in their essence, objects are what Reynolds called procedural data structures. His observation raises a natural question: if procedural data structures are the essence of objects, has this contributed to the empirical success of objects, and if so, how?\u0000 This essay attempts to answer that question. After reviewing Cook's definition, I propose the term service abstractions to capture the essential nature of objects. This terminology emphasizes, following Kay, that objects are not primarily about representing and manipulating data, but are more about providing services in support of higher-level goals. Using examples taken from object-oriented frameworks, I illustrate the unique design leverage that service abstractions provide: the ability to define abstractions that can be extended, and whose extensions are interoperable in a first-class way. The essay argues that the form of interoperable extension supported by service abstractions is essential to modern software: many modern frameworks and ecosystems could not have been built without service abstractions. In this sense, the success of objects was not a coincidence: it was an inevitable consequence of their service abstraction nature.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128198651","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}
Thomas Würthinger, Christian Wimmer, Andreas Wöß, Lukas Stadler, Gilles Duboscq, Christian Humer, G. Richards, Doug Simon, M. Wolczko
Building high-performance virtual machines is a complex and expensive undertaking; many popular languages still have low-performance implementations. We describe a new approach to virtual machine (VM) construction that amortizes much of the effort in initial construction by allowing new languages to be implemented with modest additional effort. The approach relies on abstract syntax tree (AST) interpretation where a node can rewrite itself to a more specialized or more general node, together with an optimizing compiler that exploits the structure of the interpreter. The compiler uses speculative assumptions and deoptimization in order to produce efficient machine code. Our initial experience suggests that high performance is attainable while preserving a modular and layered architecture, and that new high-performance language implementations can be obtained by writing little more than a stylized interpreter.
{"title":"One VM to rule them all","authors":"Thomas Würthinger, Christian Wimmer, Andreas Wöß, Lukas Stadler, Gilles Duboscq, Christian Humer, G. Richards, Doug Simon, M. Wolczko","doi":"10.1145/2509578.2509581","DOIUrl":"https://doi.org/10.1145/2509578.2509581","url":null,"abstract":"Building high-performance virtual machines is a complex and expensive undertaking; many popular languages still have low-performance implementations. We describe a new approach to virtual machine (VM) construction that amortizes much of the effort in initial construction by allowing new languages to be implemented with modest additional effort. The approach relies on abstract syntax tree (AST) interpretation where a node can rewrite itself to a more specialized or more general node, together with an optimizing compiler that exploits the structure of the interpreter. The compiler uses speculative assumptions and deoptimization in order to produce efficient machine code. Our initial experience suggests that high performance is attainable while preserving a modular and layered architecture, and that new high-performance language implementations can be obtained by writing little more than a stylized interpreter.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131512477","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}
Hannah Quay-de la Vallee, James M. Walsh, William Zimrin, Kathi Fisler, S. Krishnamurthi
The privacy policies of many websites, especially those designed for sharing data, are a product of many inputs. They are defined by the program underlying the website, by user configurations (such as privacy settings), and by the interactions that interfaces enable with the site. A website's security thus depends partly on users' ability to effectively use security mechanisms provided through the interface. Questions about the effectiveness of an interface are typically left to manual evaluation by user-experience experts. However, interfaces are generated by programs and user input is received and processed by programs. This suggests that aspects of usable security could also be approached as a program-analysis problem. This paper establishes a foundation on which to build formal analyses for usable security. We define a formal model for data-sharing websites. We adapt a set of design principles for usable security to modern websites and formalize them with respect to our model. In the formalization, we decompose each principle into two parts: one amenable to formal analysis, and another that requires manual evaluation by a designer. We demonstrate the potential of this approach through a preliminary analysis of models of actual sites.
{"title":"Usable security as a static-analysis problem: modeling and reasoning about user permissions in social-sharing systems","authors":"Hannah Quay-de la Vallee, James M. Walsh, William Zimrin, Kathi Fisler, S. Krishnamurthi","doi":"10.1145/2509578.2509589","DOIUrl":"https://doi.org/10.1145/2509578.2509589","url":null,"abstract":"The privacy policies of many websites, especially those designed for sharing data, are a product of many inputs. They are defined by the program underlying the website, by user configurations (such as privacy settings), and by the interactions that interfaces enable with the site. A website's security thus depends partly on users' ability to effectively use security mechanisms provided through the interface.\u0000 Questions about the effectiveness of an interface are typically left to manual evaluation by user-experience experts. However, interfaces are generated by programs and user input is received and processed by programs. This suggests that aspects of usable security could also be approached as a program-analysis problem.\u0000 This paper establishes a foundation on which to build formal analyses for usable security. We define a formal model for data-sharing websites. We adapt a set of design principles for usable security to modern websites and formalize them with respect to our model. In the formalization, we decompose each principle into two parts: one amenable to formal analysis, and another that requires manual evaluation by a designer. We demonstrate the potential of this approach through a preliminary analysis of models of actual sites.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"4 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124291511","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}
Aleksandar Milicevic, D. Jackson, Miloš Gligorić, D. Marinov
Applications are increasingly distributed and event-driven. Advances in web frameworks have made it easier to program standalone servers and their clients, but these applications remain hard to write. A model-based programming paradigm is proposed that allows a programmer to represent a distributed application as if it were a simple sequential program, with atomic actions updating a single, shared global state. A runtime environment executes the program on a collection of clients and servers, automatically handling (and hiding from the programmer) complications such as network communication (including server push), serialization, concurrency and races, persistent storage of data, and queuing and coordination of events.
{"title":"Model-based, event-driven programming paradigm for interactive web applications","authors":"Aleksandar Milicevic, D. Jackson, Miloš Gligorić, D. Marinov","doi":"10.1145/2509578.2509588","DOIUrl":"https://doi.org/10.1145/2509578.2509588","url":null,"abstract":"Applications are increasingly distributed and event-driven. Advances in web frameworks have made it easier to program standalone servers and their clients, but these applications remain hard to write. A model-based programming paradigm is proposed that allows a programmer to represent a distributed application as if it were a simple sequential program, with atomic actions updating a single, shared global state. A runtime environment executes the program on a collection of clients and servers, automatically handling (and hiding from the programmer) complications such as network communication (including server push), serialization, concurrency and races, persistent storage of data, and queuing and coordination of events.","PeriodicalId":168332,"journal":{"name":"SIGPLAN symposium on New ideas, new paradigms, and reflections on programming and software","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131899846","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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