Visualization of 3D, unsteady flow (4D) is very difficult due to both perceptual challenges and the large size of 4D vector field data. One approach to this challenge is to use integral surfaces to visualize the 4D properties of the field. However the construction of streak surfaces has remained elusive due to problems stemming from expensive computation and complex meshing schemes. We present a novel streak surface construction algorithm that generates the surface using a quadrangular mesh. In contrast to previous approaches the algorithm offers a combination of speed for exploration of 3D unsteady flow, high precision, and places less restriction on data or mesh size due to its CPU-based implementation compared to a GPU-based method. The algorithm can be applied to large data sets because it is based on local operations performed on the quad primitives. We demonstrate the technique on a variety of 3D, unsteady simulation data sets to show its speed and robustness. We also present both a detailed implementation and a performance evaluation. We show that a technique based on quad meshes handles large data sets and can achieve interactive frame rates.
{"title":"Constructing streak surfaces for 3D unsteady vector fields","authors":"Tony McLoughlin, R. Laramee, E. Zhang","doi":"10.1145/1925059.1925066","DOIUrl":"https://doi.org/10.1145/1925059.1925066","url":null,"abstract":"Visualization of 3D, unsteady flow (4D) is very difficult due to both perceptual challenges and the large size of 4D vector field data. One approach to this challenge is to use integral surfaces to visualize the 4D properties of the field. However the construction of streak surfaces has remained elusive due to problems stemming from expensive computation and complex meshing schemes. We present a novel streak surface construction algorithm that generates the surface using a quadrangular mesh. In contrast to previous approaches the algorithm offers a combination of speed for exploration of 3D unsteady flow, high precision, and places less restriction on data or mesh size due to its CPU-based implementation compared to a GPU-based method. The algorithm can be applied to large data sets because it is based on local operations performed on the quad primitives. We demonstrate the technique on a variety of 3D, unsteady simulation data sets to show its speed and robustness. We also present both a detailed implementation and a performance evaluation. We show that a technique based on quad meshes handles large data sets and can achieve interactive frame rates.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121500877","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 present the extendable volume rendering engine VRE which provides an open and flexible environment for both experimental and production level implementation of a wide range of volume visualisation algorithms, including various CPU and GPU based ones. We identify parts of renderer functionality suitable for isolation in logical units and propose various types of plugins. As the support for various volume data file formats, internal data representation and rendering algorithms is realised by the plugins, the engine can be easily extended by new functionality. We define a general application interface which enables to develop arbitrary visualisation applications, being it command line, batch ones or applications with a graphical user interface. The proposed architecture provides for multiple concurrent renderings which can be with advantage utilised in the client/server version of the engine. In this setup the server side component of the engine allows access of multiple peers to a single instance of the engine, which makes sharing of the visualised data by multiple clients possible. The VRE software is released under the GPL licence, opening the potential of the environment to all interested parties.
{"title":"The VRE volume rendering engine","authors":"M. Hucko, M. Vaněk, M. Srámek","doi":"10.1145/1925059.1925072","DOIUrl":"https://doi.org/10.1145/1925059.1925072","url":null,"abstract":"We present the extendable volume rendering engine VRE which provides an open and flexible environment for both experimental and production level implementation of a wide range of volume visualisation algorithms, including various CPU and GPU based ones. We identify parts of renderer functionality suitable for isolation in logical units and propose various types of plugins. As the support for various volume data file formats, internal data representation and rendering algorithms is realised by the plugins, the engine can be easily extended by new functionality. We define a general application interface which enables to develop arbitrary visualisation applications, being it command line, batch ones or applications with a graphical user interface. The proposed architecture provides for multiple concurrent renderings which can be with advantage utilised in the client/server version of the engine. In this setup the server side component of the engine allows access of multiple peers to a single instance of the engine, which makes sharing of the visualised data by multiple clients possible. The VRE software is released under the GPL licence, opening the potential of the environment to all interested parties.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115019794","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}
Surface area heuristics is currently the most popular method for view independent construction of spatial hierarchies for ray tracing. We present a method which modifies the surface area heuristics by taking into account the actual distribution of rays in the scene. This is achieved by subsampling the rays to be cast and using these rays in order to estimate the probabilities of rays traversing through nodes of the constructed hierarchy. The main aim of our paper is to analyze the potential of taking the ray distribution into account. The results indicate that we can achieve a minor speedup of ray traversal compared to standard SAH. For large densely occluded scene we can also save the construction time and memory consumption of the hierarchy by not subdividing parts of the scene where no rays are traced.
{"title":"RDH: ray distribution heuristics for construction of spatial data structures","authors":"Jiří Bittner, V. Havran","doi":"10.1145/1980462.1980475","DOIUrl":"https://doi.org/10.1145/1980462.1980475","url":null,"abstract":"Surface area heuristics is currently the most popular method for view independent construction of spatial hierarchies for ray tracing. We present a method which modifies the surface area heuristics by taking into account the actual distribution of rays in the scene. This is achieved by subsampling the rays to be cast and using these rays in order to estimate the probabilities of rays traversing through nodes of the constructed hierarchy. The main aim of our paper is to analyze the potential of taking the ray distribution into account. The results indicate that we can achieve a minor speedup of ray traversal compared to standard SAH. For large densely occluded scene we can also save the construction time and memory consumption of the hierarchy by not subdividing parts of the scene where no rays are traced.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125112509","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 Call 4 of the ICT program of EU's seventh framework program there is a shift of focus compared to the first three calls. 3D challenges are address under the objective "ICT-2009.1.5: Networked Media and 3D Internet" where one of the target outcomes are titled "3D Media Internet". 3D is at last on the agenda of EU's ICT-program, with a potential of becoming a central component of the future internet. The speaker has participated in the preparation of project applications for Call 4 closing/closed on April 1. 2009. He wants to share his experiences and thoughts from this work and discuss what to do in future calls when 3D is once more on the agenda.
{"title":"3D internet and experiences from proposal writing for call 4 in the FP7 ICT-program","authors":"T. Dokken","doi":"10.1145/1980462.1980467","DOIUrl":"https://doi.org/10.1145/1980462.1980467","url":null,"abstract":"In Call 4 of the ICT program of EU's seventh framework program there is a shift of focus compared to the first three calls. 3D challenges are address under the objective \"ICT-2009.1.5: Networked Media and 3D Internet\" where one of the target outcomes are titled \"3D Media Internet\". 3D is at last on the agenda of EU's ICT-program, with a potential of becoming a central component of the future internet. The speaker has participated in the preparation of project applications for Call 4 closing/closed on April 1. 2009. He wants to share his experiences and thoughts from this work and discuss what to do in future calls when 3D is once more on the agenda.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123764987","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}
Dynamic simulations can benefit a lot from an appropriate damping approach. For example, the stability is improved and a larger time step can be chosen. Furthermore, badly shaped meshes, e. g. containing sharp angles or slivers, can be handled if a proper damping approach is used. However, it must be ensured that the damping forces do not change the global movement of the object, i. e. they have to preserve linear and angular momentum. In this paper, we present a novel damping approach that is based on iterative spring damping to further improve the stability. We show that the resulting forces can be computed directly without actually performing the iterations. The approach does not require any connectivity information about the object and therefore, it can be used for arbitrary object representations. Further, it is independent of the integration scheme and the deformation model. The approach provides a simple parameter setting and guarantees that the damping forces do not overshoot. Finally, we illustrate that our approach allows for larger time steps compared to existing damping methods.
{"title":"Optimized damping for dynamic simulations","authors":"Ruediger Schmedding, M. Gissler, M. Teschner","doi":"10.1145/1980462.1980499","DOIUrl":"https://doi.org/10.1145/1980462.1980499","url":null,"abstract":"Dynamic simulations can benefit a lot from an appropriate damping approach. For example, the stability is improved and a larger time step can be chosen. Furthermore, badly shaped meshes, e. g. containing sharp angles or slivers, can be handled if a proper damping approach is used. However, it must be ensured that the damping forces do not change the global movement of the object, i. e. they have to preserve linear and angular momentum. In this paper, we present a novel damping approach that is based on iterative spring damping to further improve the stability. We show that the resulting forces can be computed directly without actually performing the iterations. The approach does not require any connectivity information about the object and therefore, it can be used for arbitrary object representations. Further, it is independent of the integration scheme and the deformation model. The approach provides a simple parameter setting and guarantees that the damping forces do not overshoot. Finally, we illustrate that our approach allows for larger time steps compared to existing damping methods.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"09 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133219274","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 present a framework for generating procedural geometry described by a context-free, parametric L-system completely on the GPU in real-time. These formal grammars allow us to easily describe various types of complex objects, such as vegetation or buildings, in a great diversity. We can create large and complex parts of the scene on-the-fly, which enables us to create a potentially infinite world of such objects. To make modeling easier, we show how the grammar description can be transformed automatically to a shader code that evaluates the L-system on the GPU. Additionally, to allow interaction with the procedural geometry, we propose an algorithm to efficiently perform discrete collision detection with the procedural scene for a large number of objects.
{"title":"Real-time generation of L-system scene models for rendering and interaction","authors":"M. Magdics","doi":"10.1145/1980462.1980478","DOIUrl":"https://doi.org/10.1145/1980462.1980478","url":null,"abstract":"We present a framework for generating procedural geometry described by a context-free, parametric L-system completely on the GPU in real-time. These formal grammars allow us to easily describe various types of complex objects, such as vegetation or buildings, in a great diversity. We can create large and complex parts of the scene on-the-fly, which enables us to create a potentially infinite world of such objects. To make modeling easier, we show how the grammar description can be transformed automatically to a shader code that evaluates the L-system on the GPU. Additionally, to allow interaction with the procedural geometry, we propose an algorithm to efficiently perform discrete collision detection with the procedural scene for a large number of objects.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129562128","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}
Real-time rendering is a quickly developing field in computer graphics. Recent advances in graphics hardware make it possible to tackle completely new challenges, and to rethink old ones. While previously, the main focus of real-time rendering lay on classical problems like visibility and level-of-detail rendering, nowadays we see new challenges in the form of interactive procedural content generation, handling of massive amounts of data, and interactive simulation of extremely complex objects like trees. In this talk, I will try to broaden the definition of realtime rendering and give some insights how to address new research challenges. Starting with a few classical problems like rendering accurate shadows, achieving smooth transitions between different levels of detail, and global visibility computations, I will then show a few examples of recent advances in real-time rendering. One challenge is the ever-increasing size of models due to automatic acquisition methods like range scanners. In a new system we have developed, we are able to visualize and interact with datasets of over 1 Billion raw points. Another source of large models is procedural modeling, and we have developed a method to aid designers in creating these models interactively. Finally, vegetation plays an important role in interactive scenes. I will show a system to simulate both illumination and animation in such complex vegetation very realistically.
{"title":"Advances in real-time rendering","authors":"M. Wimmer","doi":"10.1145/1980462.1980468","DOIUrl":"https://doi.org/10.1145/1980462.1980468","url":null,"abstract":"Real-time rendering is a quickly developing field in computer graphics. Recent advances in graphics hardware make it possible to tackle completely new challenges, and to rethink old ones. While previously, the main focus of real-time rendering lay on classical problems like visibility and level-of-detail rendering, nowadays we see new challenges in the form of interactive procedural content generation, handling of massive amounts of data, and interactive simulation of extremely complex objects like trees.\u0000 In this talk, I will try to broaden the definition of realtime rendering and give some insights how to address new research challenges. Starting with a few classical problems like rendering accurate shadows, achieving smooth transitions between different levels of detail, and global visibility computations, I will then show a few examples of recent advances in real-time rendering.\u0000 One challenge is the ever-increasing size of models due to automatic acquisition methods like range scanners. In a new system we have developed, we are able to visualize and interact with datasets of over 1 Billion raw points. Another source of large models is procedural modeling, and we have developed a method to aid designers in creating these models interactively. Finally, vegetation plays an important role in interactive scenes. I will show a system to simulate both illumination and animation in such complex vegetation very realistically.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131470391","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 this paper, we present a multi-level programming model for recent GPU-based high performance computing systems. Involving cooperative stream threads and symmetric multiprocessing threads our model gives a computational framework that scales through multi-GPU environments to GPU-cluster systems. Instead of hiding the execution environment from the programmer using compiler extensions or metaprogramming techniques we aim a solution that both enables optimizations and provides abstract problem space mapping with code reusability and virtualization of hardware resources in order to decrease the programming effort. We evaluate an implementation of our model based on CUDA, OpenMP, and MPI2 technologies on a complex practical application scenario and discuss its performance scaling behavior.
{"title":"A programming model for GPU-based parallel computing with scalability and abstraction","authors":"B. Domonkos, G. Jakab","doi":"10.1145/1980462.1980484","DOIUrl":"https://doi.org/10.1145/1980462.1980484","url":null,"abstract":"In this paper, we present a multi-level programming model for recent GPU-based high performance computing systems. Involving cooperative stream threads and symmetric multiprocessing threads our model gives a computational framework that scales through multi-GPU environments to GPU-cluster systems. Instead of hiding the execution environment from the programmer using compiler extensions or metaprogramming techniques we aim a solution that both enables optimizations and provides abstract problem space mapping with code reusability and virtualization of hardware resources in order to decrease the programming effort. We evaluate an implementation of our model based on CUDA, OpenMP, and MPI2 technologies on a complex practical application scenario and discuss its performance scaling behavior.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123341085","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}
Martin Brunnhuber, Gerd Hesina, R. Tobler, S. Mantler
The behavior of a large number of persons in big buildings is pretty difficult to predict. Long time observations have to be made and many things have to be tested in the real environment, for example how to route people around locked escalators, how to place vending or ticket machines, or how to place various kinds of advertisements. A lot of experience is needed to make the right decisions and mistakes and omissions can easily happen. Models of buildings and simulations can improve the analysis of such environments where many people move about. A good visualization of human behavior in these models can be a great help in planning and improve the quality of necessary changes. It is also possible to analyze the focus of persons who are wandering around in the building, before performing actual changes and thus judge the impact of various alternatives. A major problem is that for most buildings no adequate 3D models to perform such visualizations exist. Current building models need modeling experts for manipulation, and current simulation software needs simulation experts for analyzing movement of people within a building. Ideally, simulated movement of people should be presented in a recognizable 3D model in such a way that it can be easily identified and interpreted without further explanation. It should also be possible to manipulate the building and automatically trigger the changed simulation in the background, without being an expert. This should make it possible to explore alternative planning scenarios and improve the applicability of an envisioned planning tool. This paper presents a way to create an indoor person behavior visualization shown in its application to railway stations. The models are based on a combination of image based reconstruction and existing models of public buildings. The possibility to easily change the environment on the fly creates many possibilities to analyze alternative places for advertisement, vending and ticket machines. Therefore experiments on the real environment can be avoided to save a lot of time and money and increase customer satisfaction.
{"title":"Interactive person path analysis in reconstructed public buildings","authors":"Martin Brunnhuber, Gerd Hesina, R. Tobler, S. Mantler","doi":"10.1145/1980462.1980491","DOIUrl":"https://doi.org/10.1145/1980462.1980491","url":null,"abstract":"The behavior of a large number of persons in big buildings is pretty difficult to predict. Long time observations have to be made and many things have to be tested in the real environment, for example how to route people around locked escalators, how to place vending or ticket machines, or how to place various kinds of advertisements. A lot of experience is needed to make the right decisions and mistakes and omissions can easily happen.\u0000 Models of buildings and simulations can improve the analysis of such environments where many people move about. A good visualization of human behavior in these models can be a great help in planning and improve the quality of necessary changes. It is also possible to analyze the focus of persons who are wandering around in the building, before performing actual changes and thus judge the impact of various alternatives.\u0000 A major problem is that for most buildings no adequate 3D models to perform such visualizations exist. Current building models need modeling experts for manipulation, and current simulation software needs simulation experts for analyzing movement of people within a building.\u0000 Ideally, simulated movement of people should be presented in a recognizable 3D model in such a way that it can be easily identified and interpreted without further explanation. It should also be possible to manipulate the building and automatically trigger the changed simulation in the background, without being an expert. This should make it possible to explore alternative planning scenarios and improve the applicability of an envisioned planning tool.\u0000 This paper presents a way to create an indoor person behavior visualization shown in its application to railway stations. The models are based on a combination of image based reconstruction and existing models of public buildings. The possibility to easily change the environment on the fly creates many possibilities to analyze alternative places for advertisement, vending and ticket machines. Therefore experiments on the real environment can be avoided to save a lot of time and money and increase customer satisfaction.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129626455","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 this paper, we propose a randomized algorithm that allows to delete a point in three--dimensional regular or Delaunay triangulation by a sequence of flips. All the previous algorithms check regularity of each new tetrahedron globally, i.e. with respect to all vertices of tetrahedra incident to the point, which is being deleted. In contrast, the proposed hybrid algorithm uses a combination of local and global regularity tests. First, the proposed algorithm tries to delete a point by a randomized sequence of flips of faces satisfying a certain local condition. This simple approach will always delete the point successfully, but theoretically in an unbounded time in the worst case. Therefore we combine it with the global regularity tests -- if the point is not deleted after a certain number of flips, the proposed algorithm replaces the local regularity test by the global regularity test. In practice, the local regularity tests are sufficient in most cases and the global regularity tests are used only rarely. In consequence, the proposed algorithm needs less tests of regularity in average than the previous algorithms.
{"title":"Hybrid algorithm for deletion of a point in regular and Delaunay triangulation","authors":"Michal Zemek, I. Kolingerová","doi":"10.1145/1980462.1980490","DOIUrl":"https://doi.org/10.1145/1980462.1980490","url":null,"abstract":"In this paper, we propose a randomized algorithm that allows to delete a point in three--dimensional regular or Delaunay triangulation by a sequence of flips. All the previous algorithms check regularity of each new tetrahedron globally, i.e. with respect to all vertices of tetrahedra incident to the point, which is being deleted. In contrast, the proposed hybrid algorithm uses a combination of local and global regularity tests. First, the proposed algorithm tries to delete a point by a randomized sequence of flips of faces satisfying a certain local condition. This simple approach will always delete the point successfully, but theoretically in an unbounded time in the worst case. Therefore we combine it with the global regularity tests -- if the point is not deleted after a certain number of flips, the proposed algorithm replaces the local regularity test by the global regularity test. In practice, the local regularity tests are sufficient in most cases and the global regularity tests are used only rarely. In consequence, the proposed algorithm needs less tests of regularity in average than the previous algorithms.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116323394","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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