The influence of parallelism on the performance of competitive adaptive differential evolution is studied. Two serial competitive differential evolution variants described in literature and sixteen novel parallel variants were experimentally compared. All the parallel differential evolution variants in this study are based on a migration model with the star topology. The algorithms were compared on six benchmark functions with two levels of dimension (D = 10 and D = 30). The number of the function evaluations and the reliability rate of the search were used as basic characteristics of algorithm's performance. The experimental results show that the parallelism applied to competitive differential evolution together with a proper setting of the parameters controlling the parallel model can improve the performance of the algorithm and decrease the computational costs significantly at least in some problems.
{"title":"Parallel Migration Models Applied to Competitive Differential Evolution","authors":"P. Bujok, J. Tvrdík","doi":"10.1109/SYNASC.2011.45","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.45","url":null,"abstract":"The influence of parallelism on the performance of competitive adaptive differential evolution is studied. Two serial competitive differential evolution variants described in literature and sixteen novel parallel variants were experimentally compared. All the parallel differential evolution variants in this study are based on a migration model with the star topology. The algorithms were compared on six benchmark functions with two levels of dimension (D = 10 and D = 30). The number of the function evaluations and the reliability rate of the search were used as basic characteristics of algorithm's performance. The experimental results show that the parallelism applied to competitive differential evolution together with a proper setting of the parameters controlling the parallel model can improve the performance of the algorithm and decrease the computational costs significantly at least in some problems.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"283 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121052347","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}
This paper describes a cellular genetic algorithm with communicating grids for solving a delivery problem. Specific operators for mutation and crossover are described. The GA is hybridized using a heuristic that is acting as a hyper-mutation operator. It is inspired from a very efficient dynamic programming algorithm. A similarity vector is associated to each solution. A Kohonen self-organizing map is used to place the initial population on the grid and specific placement techniques are applied during the whole activity. These techniques favor the groups based on similarity. The position of groups on the grid and their contents are dynamic. A similarity based communication protocol is used to change a given percent of the best individuals of the clusters and a given threshold is used to tune the communication scheme. The performance of the algorithm is experimentally analyzed: the capacity of the cellular algorithm to find known optimal solutions, its stability in terms of the unitized risk values, the way to obtain good values of the parameters is described, different similarity function are compared between them and the threshold values for optimal clustering and communication protocol are obtained. Also, the effect of communication period and the percent of changed individuals on the quality of the found solution are analyzed. The results show that the cellular algorithm dominates the canonical counterpart hybrid genetic algorithms.
{"title":"Cellular Genetic Algorithm with Communicating Grids for a Delivery Problem","authors":"O. Brudaru, A. Vilcu, D. Popovici","doi":"10.1109/SYNASC.2011.58","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.58","url":null,"abstract":"This paper describes a cellular genetic algorithm with communicating grids for solving a delivery problem. Specific operators for mutation and crossover are described. The GA is hybridized using a heuristic that is acting as a hyper-mutation operator. It is inspired from a very efficient dynamic programming algorithm. A similarity vector is associated to each solution. A Kohonen self-organizing map is used to place the initial population on the grid and specific placement techniques are applied during the whole activity. These techniques favor the groups based on similarity. The position of groups on the grid and their contents are dynamic. A similarity based communication protocol is used to change a given percent of the best individuals of the clusters and a given threshold is used to tune the communication scheme. The performance of the algorithm is experimentally analyzed: the capacity of the cellular algorithm to find known optimal solutions, its stability in terms of the unitized risk values, the way to obtain good values of the parameters is described, different similarity function are compared between them and the threshold values for optimal clustering and communication protocol are obtained. Also, the effect of communication period and the percent of changed individuals on the quality of the found solution are analyzed. The results show that the cellular algorithm dominates the canonical counterpart hybrid genetic algorithms.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125734415","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}
Distributed computing systems provide a highly dynamic behavior which originates from heterogeneous computing and storage resources, heterogeneous users and the variety of submitted applications and finally from the heterogeneous communication that takes part among the systems entities. As such applying global optima oriented allocation algorithms usually produces poor results and heuristics are used instead. We concentrated our experiments around the Sufferage heuristic and its adaptive cluster-aware version XSufferage. Both Sufferage and XSufferage use a centralized design and produce good results for low levels of dynamism and deterministic environments. In real life distributed environments, both heuristics produce poor results. We expose the Sufferage heuristic through a distributed architecture based on a cooperative set of entities, which form a Multi-Agent System, such that the results could be improved. We implemented a new algorithm, based on this architecture, called Distributed XSufferage. In order to test the new algorithm, a series of experiments were developed by simulating two real life Grid environments. A complex set of performance metrics were collected -- flow time, make span, throughput -- both resource and cluster level, utilization -- both resource and cluster level and resources and clusters mean loads. Algorithms produce their allocation solution based on estimates and modeling of system's resources and as such are sensitive to estimation errors. Throughout our experiments DX Sufferage was more robust to such errors compared to the original Sufferage and, respectively, XSufferage heuristics.
{"title":"Multi-agent Resource Allocation Algorithm Based on the XSufferage Heuristic for Distributed Systems","authors":"Alexandru Gherega, Valentin Pupezescu","doi":"10.1109/SYNASC.2011.37","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.37","url":null,"abstract":"Distributed computing systems provide a highly dynamic behavior which originates from heterogeneous computing and storage resources, heterogeneous users and the variety of submitted applications and finally from the heterogeneous communication that takes part among the systems entities. As such applying global optima oriented allocation algorithms usually produces poor results and heuristics are used instead. We concentrated our experiments around the Sufferage heuristic and its adaptive cluster-aware version XSufferage. Both Sufferage and XSufferage use a centralized design and produce good results for low levels of dynamism and deterministic environments. In real life distributed environments, both heuristics produce poor results. We expose the Sufferage heuristic through a distributed architecture based on a cooperative set of entities, which form a Multi-Agent System, such that the results could be improved. We implemented a new algorithm, based on this architecture, called Distributed XSufferage. In order to test the new algorithm, a series of experiments were developed by simulating two real life Grid environments. A complex set of performance metrics were collected -- flow time, make span, throughput -- both resource and cluster level, utilization -- both resource and cluster level and resources and clusters mean loads. Algorithms produce their allocation solution based on estimates and modeling of system's resources and as such are sensitive to estimation errors. Throughout our experiments DX Sufferage was more robust to such errors compared to the original Sufferage and, respectively, XSufferage heuristics.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126362153","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 investigate computational resources used by alternating Turing machines (ATMs) to accept Szilard languages (SZLs) of context-free matrix grammars (MGs). The main goal is to relate these languages to parallel complexity classes such as NC1 and NC2. We prove that unrestricted and leftmost-1 SZLs of context-free MGs, without appearance checking, can be accepted by ATMs in logarithmic time and space. Hence, these classes of languages belong to NC1 (under ALOGTIME reduction). Unrestricted SZLs of context-free MGs with appearance checking can be accepted by ATMs in logarithmic space and square logarithmic time. Consequently, this class is contained in NC2. We conclude with some results on SZLs of MGs with phrase-structure rules.
{"title":"On the Complexity of Szilard Languages of Matrix Grammars","authors":"Liliana Cojocaru, E. Mäkinen","doi":"10.1109/SYNASC.2011.34","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.34","url":null,"abstract":"We investigate computational resources used by alternating Turing machines (ATMs) to accept Szilard languages (SZLs) of context-free matrix grammars (MGs). The main goal is to relate these languages to parallel complexity classes such as NC1 and NC2. We prove that unrestricted and leftmost-1 SZLs of context-free MGs, without appearance checking, can be accepted by ATMs in logarithmic time and space. Hence, these classes of languages belong to NC1 (under ALOGTIME reduction). Unrestricted SZLs of context-free MGs with appearance checking can be accepted by ATMs in logarithmic space and square logarithmic time. Consequently, this class is contained in NC2. We conclude with some results on SZLs of MGs with phrase-structure rules.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123569288","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}
This article introduces Range Lab, a simple tool to validate the accuracy of floating-point or fixed-point computations. Given intervals for the inputs, Range Lab computes the range of the outputs of simple functions with conditionals and loops as well as a range for the round off errors arising during the computation. Hence the user not only obtains the range of the result of the computation in the computer arithmetic but also a bound on the difference between the computer result and the result in infinite precision. Range Lab is based on static analysis by abstract interpretation and, in this article, we describe the techniques implemented in the tool. In particular, Range Lab uses a hybrid numerical-formal evaluation technique used to limit the wrapping effect in interval computations.
{"title":"RangeLab: A Static-Analyzer to Bound the Accuracy of Finite-Precision Computations","authors":"M. Martel","doi":"10.1109/SYNASC.2011.52","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.52","url":null,"abstract":"This article introduces Range Lab, a simple tool to validate the accuracy of floating-point or fixed-point computations. Given intervals for the inputs, Range Lab computes the range of the outputs of simple functions with conditionals and loops as well as a range for the round off errors arising during the computation. Hence the user not only obtains the range of the result of the computation in the computer arithmetic but also a bound on the difference between the computer result and the result in infinite precision. Range Lab is based on static analysis by abstract interpretation and, in this article, we describe the techniques implemented in the tool. In particular, Range Lab uses a hybrid numerical-formal evaluation technique used to limit the wrapping effect in interval computations.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134306348","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}
V. Jevtic, D. Dobrilović, Jelena Stojanov, Ž. Stojanov
This paper presents project duration assessment model based on modification of shortest path algorithms and superposition. One of the shortest path algorithms, Dijkstra algorithm, is modified in order to find the longest path. This is used for critical path calculation, i.e. for resolving project duration assessment problem. Another modification of algorithm calculates sub critical path as the second longest one. These paths are used for superposition, because of stochastic nature of many research and development projects which can cause that at some point in time sub critical becomes critical path. Thus, sub critical path influence on project duration should be taken into account, and, in this case, superposition is used for that. Superposition used in the model is based on analytical method -- Clark's formulas. Presented model can be used for business process improvement and project management support.
{"title":"Project Duration Assessment Model Based on Modified Shortest Path Algorithm and Superposition","authors":"V. Jevtic, D. Dobrilović, Jelena Stojanov, Ž. Stojanov","doi":"10.1109/SYNASC.2011.29","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.29","url":null,"abstract":"This paper presents project duration assessment model based on modification of shortest path algorithms and superposition. One of the shortest path algorithms, Dijkstra algorithm, is modified in order to find the longest path. This is used for critical path calculation, i.e. for resolving project duration assessment problem. Another modification of algorithm calculates sub critical path as the second longest one. These paths are used for superposition, because of stochastic nature of many research and development projects which can cause that at some point in time sub critical becomes critical path. Thus, sub critical path influence on project duration should be taken into account, and, in this case, superposition is used for that. Superposition used in the model is based on analytical method -- Clark's formulas. Presented model can be used for business process improvement and project management support.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"7 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114116379","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}
Outlier detection is widely applied in several fields such as data mining, pattern recognition and bioinformatics. The algorithms used for outlier detection are based mainly on statistics and artificial intelligence. Our long-term goal is to study and apply the principles of human vision for solving outlier detection problems. Here we present an algorithm suitable for outlier detection based on the principles of Gestalt psychology. We demonstrate the algorithm's main properties on an example taken from human perception, the recognition of continuous curves formed of Gabor patches embedded into a noisy background. We show that the algorithm is tolerant with respect to added noise and is orientation independent. As a potential application we present the problem of filtering proteomics mass spectrometry data. The true peaks within a measured mass spectrum can be represented as a graph in which nodes are fragment peaks while edges represent equivalents of proximity, similarity and continuity defined in terms of chemical rules. The applicability of the principle to further problems is discussed.
{"title":"Psychologically Inspired, Rule-Based Outlier Detection in Noisy Data","authors":"Beáta Reiz, S. Pongor","doi":"10.1109/SYNASC.2011.57","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.57","url":null,"abstract":"Outlier detection is widely applied in several fields such as data mining, pattern recognition and bioinformatics. The algorithms used for outlier detection are based mainly on statistics and artificial intelligence. Our long-term goal is to study and apply the principles of human vision for solving outlier detection problems. Here we present an algorithm suitable for outlier detection based on the principles of Gestalt psychology. We demonstrate the algorithm's main properties on an example taken from human perception, the recognition of continuous curves formed of Gabor patches embedded into a noisy background. We show that the algorithm is tolerant with respect to added noise and is orientation independent. As a potential application we present the problem of filtering proteomics mass spectrometry data. The true peaks within a measured mass spectrum can be represented as a graph in which nodes are fragment peaks while edges represent equivalents of proximity, similarity and continuity defined in terms of chemical rules. The applicability of the principle to further problems is discussed.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129479674","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}
This paper proposes a probabilistic model for automated reasoning for identifying the lane on which the vehicle is driving on. The solution is based on the visual information from an on-board stereo-vision camera and a priori information from an extended digital map. The visual perception system provides information about on-the-spot detected lateral landmarks, as well as about other important traffic elements such as other vehicles. The proposed extended digital map provides lane level detail information about the road infrastructure. An Object-Oriented Bayesian Network is modeled to reason about the lane on which the ego-vehicle is driving on using the information from these two input systems. The probabilistic approach is suitable because of the uncertain and inaccurate nature of the sensorial information. Due to the need of lateral painted landmarks, the method is dedicated to the segment of roads linked to an intersection.
{"title":"Probabilistic Approach for Automated Reasoning for Lane Identification in Intelligent Vehicles","authors":"V. Popescu, Mihai Bâce, S. Nedevschi","doi":"10.1109/SYNASC.2011.10","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.10","url":null,"abstract":"This paper proposes a probabilistic model for automated reasoning for identifying the lane on which the vehicle is driving on. The solution is based on the visual information from an on-board stereo-vision camera and a priori information from an extended digital map. The visual perception system provides information about on-the-spot detected lateral landmarks, as well as about other important traffic elements such as other vehicles. The proposed extended digital map provides lane level detail information about the road infrastructure. An Object-Oriented Bayesian Network is modeled to reason about the lane on which the ego-vehicle is driving on using the information from these two input systems. The probabilistic approach is suitable because of the uncertain and inaccurate nature of the sensorial information. Due to the need of lateral painted landmarks, the method is dedicated to the segment of roads linked to an intersection.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116078046","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 aim of this paper is to provide a basic software tool involved in the design and the computation of nonlinear digital control schemes. The complete software SimNLSys will include different modules associated with each control scheme, aimed with respective objectives such as stabilization, damping, output matching or optimality, to quote a few. The software module presented here also encompasses the goal of computing solutions to nonlinear ODE's describing input-affine dynamics. The underlying methodologies propose challenging nonlinear sampled-data control strategies described in terms of Lie series expansions and computable through formal series calculus. The goal is to reach a friendly graphical user interface, to promote the practical efficiency of such strategies. For this, SymNLSys is built using the symbolic Matlab toolbox and the resulting mathematical control law expressions can be implemented directly on experimental plants. The paper describes the used differential geometric methods and discusses the implementation and limitations of the symbolic and numerical algorithms. Also some results obtained via this software are provided.
{"title":"A Computer Aided Software for Nonlinear Digital Control","authors":"V. Tanasa, D. Normand-Cyrot","doi":"10.1109/SYNASC.2011.42","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.42","url":null,"abstract":"The aim of this paper is to provide a basic software tool involved in the design and the computation of nonlinear digital control schemes. The complete software SimNLSys will include different modules associated with each control scheme, aimed with respective objectives such as stabilization, damping, output matching or optimality, to quote a few. The software module presented here also encompasses the goal of computing solutions to nonlinear ODE's describing input-affine dynamics. The underlying methodologies propose challenging nonlinear sampled-data control strategies described in terms of Lie series expansions and computable through formal series calculus. The goal is to reach a friendly graphical user interface, to promote the practical efficiency of such strategies. For this, SymNLSys is built using the symbolic Matlab toolbox and the resulting mathematical control law expressions can be implemented directly on experimental plants. The paper describes the used differential geometric methods and discusses the implementation and limitations of the symbolic and numerical algorithms. Also some results obtained via this software are provided.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123930634","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}
This paper introduces a multi-agent framework for distributed multiplayer game development and simulations. The framework allows the incorporation and experimentation with different strategies of the Players, possibly including intelligent behaviors. The framework consists of a set of generic agent types that must be specialized and configured for a specific game. The framework uses a generic agent that enforces the rules of the game, as well as generic bot-agents that represent the game Players. To support our claims of flexibility and generality we present three simple games implemented on top of our framework: football, battle and labyrinth. Game configuration details are presented as rules imposed on agent actions. We also present simple agents and their strategies to demonstrate how to use the framework in a practical setting.
{"title":"Software Framework for Agent-Based Games and Simulations","authors":"George Sacerdotianu, S. Ilie, C. Bǎdicǎ","doi":"10.1109/SYNASC.2011.32","DOIUrl":"https://doi.org/10.1109/SYNASC.2011.32","url":null,"abstract":"This paper introduces a multi-agent framework for distributed multiplayer game development and simulations. The framework allows the incorporation and experimentation with different strategies of the Players, possibly including intelligent behaviors. The framework consists of a set of generic agent types that must be specialized and configured for a specific game. The framework uses a generic agent that enforces the rules of the game, as well as generic bot-agents that represent the game Players. To support our claims of flexibility and generality we present three simple games implemented on top of our framework: football, battle and labyrinth. Game configuration details are presented as rules imposed on agent actions. We also present simple agents and their strategies to demonstrate how to use the framework in a practical setting.","PeriodicalId":184344,"journal":{"name":"2011 13th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124293857","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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