Software Process Workshop (SPW 2005) was held in Beijing on May 25-27, 2005. This paper introduces the motivation of organizing such a workshop, as well as its theme and paper gathering and review; and summarizes the ...Software Process Workshop (SPW 2005) was held in Beijing on May 25-27, 2005. This paper introduces the motivation of organizing such a workshop, as well as its theme and paper gathering and review; and summarizes the main content and insights of 11 keynote speeches, 30 regular papers in five sessions of “Process Content”, “Process Tools and Metrics”, “Process Management”, “Process Representation and Analysis”, and “Experience Reports”, 8 software development support tools demonstration, and the ending panel “Where Are We Now? Where Should We Go Next?”.展开更多
Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfa...Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfaces and introduce a curvature representation of details, and then present surfaces editing applications based on their curvature representation. We apply our method to surfaces with complex boundaries and rich details. Results show the validity and robustness of our method and dem- onstrate curvature map can be a helpful surfaces detail representation.展开更多
Fluid and solid simulation is to generate a realistic simulation of fluids and solids,in particular for the fluids such as water and smoke,with computation of Euler equations or Navier-Stokes equations conducted to go...Fluid and solid simulation is to generate a realistic simulation of fluids and solids,in particular for the fluids such as water and smoke,with computation of Euler equations or Navier-Stokes equations conducted to govern the real fluid physics.Fluid simulation is an important field by its wide applications in many fields and industries,such as film and game simulation,weather forecasting,natural disaster simulation and protection,simulation in maritime and aviation.There are basically two main categories of methods for fluid simulation,data-driven methods and physically-based methods.The data-driven models establish a direct mapping between variables and extract their relationship from historically measured data by the algorithms developed in the fields of statistics,computational intelligence,machine learning,and data mining.展开更多
The imperfect material effect is one of the most important themes to obtain photo-realistic results in rendering.Textile material rendering has always been a key area in the field of computer graphics.So far,a great d...The imperfect material effect is one of the most important themes to obtain photo-realistic results in rendering.Textile material rendering has always been a key area in the field of computer graphics.So far,a great deal of effort has been invested in its unique appearance and physics-based simulation.The appearance of the dyeing effect commonly found in textiles has received little attention.This paper introduces techniques for simulation of staining effects on textiles.Pulling,wearing,squeezing,tearing,and breaking effects are more common imperfect effects of fabrics,these external forces will cause changes in the fabric structure,thus affecting the diffusion effect of stains.Based on the microstructure of yarn,we handle the effect of the stain on the imperfect textile surface.Our simulation results can achieve a photo-realistic effect.展开更多
Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction r...Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction results.Additionally,as trajectories play a much more important role in crossing-based target selection compared to the other interactive techniques,an ideal model for trajectories can help computer designers make predictions about interaction results during the process of target selection rather than at the end of the whole process.Methods In this paper,a trajectory prediction model for crossing based target selection tasks is proposed by taking the reference of a dynamic model theory.Results Simulation results demonstrate that our model performed well with regard to the prediction of trajectories,endpoints and hitting time for target-selection motion,and the average error of trajectories,endpoints and hitting time values were found to be 17.28%,2.73mm and 11.50%,respectively.展开更多
This paper presents the formal specification and model-checklng of Carrier Sense Multiple Access with Collision Avoidance（ CSMA/CA） protocol using the model checker we developed for real-time systems, which are spec...This paper presents the formal specification and model-checklng of Carrier Sense Multiple Access with Collision Avoidance（ CSMA/CA） protocol using the model checker we developed for real-time systems, which are specified as networks of finite precision timed automata. The CSMA/CA protocol proposed in the IEEE 802.11 standard is designed to reduce the probability of collision during a transmission in wireless random access environments. However, it does not eliminate completely the possibility of a collision between two or more frames transmitted simultaneously. We investigate what will give rise to a collision between frames and use our automatic verification tool for model-checking.展开更多
Container-based virtualization isbecoming increasingly popular in cloud computing due to its efficiency and flexibility.Resource isolation is a fundamental property of containers.Existing works have indicated weak res...Container-based virtualization isbecoming increasingly popular in cloud computing due to its efficiency and flexibility.Resource isolation is a fundamental property of containers.Existing works have indicated weak resource isolation could cause significant performance degradation for containerized applications and enhanced resource isolation.However,current studies have almost not discussed the isolation problems of page cache which is a key resource for containers.Containers leverage memory cgroup to control page cache usage.Unfortunately,existing policy introduces two major problems in a container-based environment.First,containers can utilize more memory than limited by their cgroup,effectively breaking memory isolation.Second,the Os kernel has to evict page cache to make space for newly-arrived memory requests,slowing down containerized applications.This paper performs an empirical study of these problems and demonstrates the performance impacts on containerized applications.Then we propose pCache(precise control of page cache)to address the problems by dividing page cache into private and shared and controlling both kinds of page cache separately and precisely.To do so,pCache leverages two new technologies:fair account(f-account)and evict on demand(EoD).F-account splits the shared page cache charging based on per-container share to prevent containers from using memory for free,enhancing memory isolation.And EoD reduces unnecessary page cache evictions to avoid the performance impacts.The evaluation results demonstrate that our system can effectively enhance memory isolation for containers and achieve substantial performance improvement over the original page cache management policy.展开更多
Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications...Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis （PCA） are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000＋ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.展开更多
Although many graph processing systems have been proposed, graphs in the real-world are often dynamic. It is important to keep the results of graph computation up-todate. Incremental computation is demonstrated to be ...Although many graph processing systems have been proposed, graphs in the real-world are often dynamic. It is important to keep the results of graph computation up-todate. Incremental computation is demonstrated to be an efficient solution to update calculated results. Recently, many incremental graph processing systems have been proposed to handle dynamic graphs in an asynchronous way and are able to achieve better performance than those processed in a synchronous way. However, these solutions still suffer from sub-optimal convergence speed due to their slow propagation of important vertex state (important to convergence speed) and poor locality. In order to solve these problems, we propose a novel graph processing framework. It introduces a dynamic partition method to gather the important vertices for high locality, and then uses a priority-based scheduling algorithm to assign them with a higher priority for an effective processing order. By such means, it is able to reduce the number of updates and increase the locality, thereby reducing the convergence time. Experimental results show that our method reduces the number of updates by 30%, and reduces the total execution time by 35%, compared with state-of-the-art systems.展开更多
To satisfy the rapid growth of cloud technologies, a large number of web applications have been developed and deployed, and these applications are being run in clouds. Due to the scalability provided by clouds, a sing...To satisfy the rapid growth of cloud technologies, a large number of web applications have been developed and deployed, and these applications are being run in clouds. Due to the scalability provided by clouds, a single web application may be concurrently visited by several millions or billions of users. Thus, the testing and performance evaluations of these applications are increasingly important. User model based evaluations can significantly reduce the manual work required, and can enable us to determine the performance of applications under real runtime environments. Hence, it has become one of the most popular evaluation methods in both industry and academia. Significant efforts have focused on building different kinds of models using mining web access logs, such as Markov models and Customer Behavior Model Graph （CBMG）. This paper proposes a new kind of model, named the User Representation Model Graph （URMG）, which is built based on CBMG. It uses an algorithm to refine CBMG and optimizes the evaluations execution process. Based on this model, an automatic testing and evaluation system for web applications is designed, implemented, and deployed in our test cloud, which is able to execute all of the analysis and testing operations using only web access logs. In our system, the error rate caused by random access to applications in the execution phase is also reduced, and the results show that the error rate of the evaluation that depends on URMG is 50% less than that which depends on CBMG.展开更多
This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these ch...This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these changes, we simulate the lighting transportation process at run time, which is normally impractical for interactive use due to its huge computational burden. We greatly alleviate this burden by a hierarchical structure named a transportation tree that clusters similar emitting samples together within a perceptually acceptable error bound. Furthermore, by exploiting the coherence in time as well as in space, we incrementally adjust the clusters rather than computing them from scratch in each frame. With a pre-computed visibility map, we are able to efficiently estimate the indirect illumination in parallel on graphics hardware, by simply summing up the radiance shoots from cluster representatives, plus a small number of operations of merging and splitting on clusters. With relighting based on the time-varying clusters, interactive update of global illumination effects with multi-bounced indirect lighting is demonstrated in applications to material animation and scene decoration.展开更多
Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper pr...Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.展开更多
With the ever-growing data and the need for developing powerful machine learning models,data owners increasingly depend on various untrusted platforms(e.g.,public clouds,edges,and machine learning service providers)fo...With the ever-growing data and the need for developing powerful machine learning models,data owners increasingly depend on various untrusted platforms(e.g.,public clouds,edges,and machine learning service providers)for scalable processing or collaborative learning.Thus,sensitive data and models are in danger of unauthorized access,misuse,and privacy compromises.A relatively new body of research confidentially trains machine learning models on protected data to address these concerns.In this survey,we summarize notable studies in this emerging area of research.With a unified framework,we highlight the critical challenges and innovations in outsourcing machine learning confidentially.We focus on the cryptographic approaches for confidential machine learning(CML),primarily on model training,while also covering other directions such as perturbation-based approaches and CML in the hardware-assisted computing environment.The discussion will take a holistic way to consider a rich context of the related threat models,security assumptions,design principles,and associated trade-offs amongst data utility,cost,and confidentiality.展开更多
文摘Software Process Workshop (SPW 2005) was held in Beijing on May 25-27, 2005. This paper introduces the motivation of organizing such a workshop, as well as its theme and paper gathering and review; and summarizes the main content and insights of 11 keynote speeches, 30 regular papers in five sessions of “Process Content”, “Process Tools and Metrics”, “Process Management”, “Process Representation and Analysis”, and “Experience Reports”, 8 software development support tools demonstration, and the ending panel “Where Are We Now? Where Should We Go Next?”.
基金Project supported by the National Basic Research Program (973) of China (No. 2002CB312102), and the Research Grant of University of Macao, China
文摘Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfaces and introduce a curvature representation of details, and then present surfaces editing applications based on their curvature representation. We apply our method to surfaces with complex boundaries and rich details. Results show the validity and robustness of our method and dem- onstrate curvature map can be a helpful surfaces detail representation.
文摘Fluid and solid simulation is to generate a realistic simulation of fluids and solids,in particular for the fluids such as water and smoke,with computation of Euler equations or Navier-Stokes equations conducted to govern the real fluid physics.Fluid simulation is an important field by its wide applications in many fields and industries,such as film and game simulation,weather forecasting,natural disaster simulation and protection,simulation in maritime and aviation.There are basically two main categories of methods for fluid simulation,data-driven methods and physically-based methods.The data-driven models establish a direct mapping between variables and extract their relationship from historically measured data by the algorithms developed in the fields of statistics,computational intelligence,machine learning,and data mining.
文摘The imperfect material effect is one of the most important themes to obtain photo-realistic results in rendering.Textile material rendering has always been a key area in the field of computer graphics.So far,a great deal of effort has been invested in its unique appearance and physics-based simulation.The appearance of the dyeing effect commonly found in textiles has received little attention.This paper introduces techniques for simulation of staining effects on textiles.Pulling,wearing,squeezing,tearing,and breaking effects are more common imperfect effects of fabrics,these external forces will cause changes in the fabric structure,thus affecting the diffusion effect of stains.Based on the microstructure of yarn,we handle the effect of the stain on the imperfect textile surface.Our simulation results can achieve a photo-realistic effect.
基金National Key R&D Program of China(2016YFB1001405)the National Natural Science Foundation of China(61802379)Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-JSC041).
文摘Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction results.Additionally,as trajectories play a much more important role in crossing-based target selection compared to the other interactive techniques,an ideal model for trajectories can help computer designers make predictions about interaction results during the process of target selection rather than at the end of the whole process.Methods In this paper,a trajectory prediction model for crossing based target selection tasks is proposed by taking the reference of a dynamic model theory.Results Simulation results demonstrate that our model performed well with regard to the prediction of trajectories,endpoints and hitting time for target-selection motion,and the average error of trajectories,endpoints and hitting time values were found to be 17.28%,2.73mm and 11.50%,respectively.
基金The workreportedinthis paperissupported bythe National Grand Fundamental Research973 Programof China (2002cb312200) ,andthe National Nat-ural Science Foundation of China(60242002 ,60273025)
文摘This paper presents the formal specification and model-checklng of Carrier Sense Multiple Access with Collision Avoidance（ CSMA/CA） protocol using the model checker we developed for real-time systems, which are specified as networks of finite precision timed automata. The CSMA/CA protocol proposed in the IEEE 802.11 standard is designed to reduce the probability of collision during a transmission in wireless random access environments. However, it does not eliminate completely the possibility of a collision between two or more frames transmitted simultaneously. We investigate what will give rise to a collision between frames and use our automatic verification tool for model-checking.
基金supported by the National Key Research and Development Program (2022YFB4500704)the National Natural Science Foundation of China (Grant Nos.62032008,62232012 and 62232011).
文摘Container-based virtualization isbecoming increasingly popular in cloud computing due to its efficiency and flexibility.Resource isolation is a fundamental property of containers.Existing works have indicated weak resource isolation could cause significant performance degradation for containerized applications and enhanced resource isolation.However,current studies have almost not discussed the isolation problems of page cache which is a key resource for containers.Containers leverage memory cgroup to control page cache usage.Unfortunately,existing policy introduces two major problems in a container-based environment.First,containers can utilize more memory than limited by their cgroup,effectively breaking memory isolation.Second,the Os kernel has to evict page cache to make space for newly-arrived memory requests,slowing down containerized applications.This paper performs an empirical study of these problems and demonstrates the performance impacts on containerized applications.Then we propose pCache(precise control of page cache)to address the problems by dividing page cache into private and shared and controlling both kinds of page cache separately and precisely.To do so,pCache leverages two new technologies:fair account(f-account)and evict on demand(EoD).F-account splits the shared page cache charging based on per-container share to prevent containers from using memory for free,enhancing memory isolation.And EoD reduces unnecessary page cache evictions to avoid the performance impacts.The evaluation results demonstrate that our system can effectively enhance memory isolation for containers and achieve substantial performance improvement over the original page cache management policy.
基金The IOS authors are partially supported by the National High Technology Development 863 Program of China under Grant No.2006AA01Z306the National Grand Fundamental Research 973 Program of China under Grant No.2002CB312102.
文摘Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis （PCA） are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000＋ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.
基金the National Natural Science Foundation of China (Grant No. 61702202)China Postdoctoral Science Foundation Funded Project (2017M610477 and 2017T100555).
文摘Although many graph processing systems have been proposed, graphs in the real-world are often dynamic. It is important to keep the results of graph computation up-todate. Incremental computation is demonstrated to be an efficient solution to update calculated results. Recently, many incremental graph processing systems have been proposed to handle dynamic graphs in an asynchronous way and are able to achieve better performance than those processed in a synchronous way. However, these solutions still suffer from sub-optimal convergence speed due to their slow propagation of important vertex state (important to convergence speed) and poor locality. In order to solve these problems, we propose a novel graph processing framework. It introduces a dynamic partition method to gather the important vertices for high locality, and then uses a priority-based scheduling algorithm to assign them with a higher priority for an effective processing order. By such means, it is able to reduce the number of updates and increase the locality, thereby reducing the convergence time. Experimental results show that our method reduces the number of updates by 30%, and reduces the total execution time by 35%, compared with state-of-the-art systems.
基金supported by the National Natural Science Foundation of China(No.61232008)the National High-Tech Research and Development(863)Program of China(Nos.2013AA01A213 and 2013AA01A208)+1 种基金Chinese Universities Scientific Fund(No.2013TS094)Guangzhou Science and Technology Program(No.2012Y2-00040)
文摘To satisfy the rapid growth of cloud technologies, a large number of web applications have been developed and deployed, and these applications are being run in clouds. Due to the scalability provided by clouds, a single web application may be concurrently visited by several millions or billions of users. Thus, the testing and performance evaluations of these applications are increasingly important. User model based evaluations can significantly reduce the manual work required, and can enable us to determine the performance of applications under real runtime environments. Hence, it has become one of the most popular evaluation methods in both industry and academia. Significant efforts have focused on building different kinds of models using mining web access logs, such as Markov models and Customer Behavior Model Graph （CBMG）. This paper proposes a new kind of model, named the User Representation Model Graph （URMG）, which is built based on CBMG. It uses an algorithm to refine CBMG and optimizes the evaluations execution process. Based on this model, an automatic testing and evaluation system for web applications is designed, implemented, and deployed in our test cloud, which is able to execute all of the analysis and testing operations using only web access logs. In our system, the error rate caused by random access to applications in the execution phase is also reduced, and the results show that the error rate of the evaluation that depends on URMG is 50% less than that which depends on CBMG.
基金Supported by the National Basic Research Program of China (Grant No. 2009CB320802)the National Natural Science Foundation of China(Grant No. 60833007)+1 种基金the National High-Tech Research & Development Progran of China (Grant No. 2008AA01Z301)the ResearchGrant of the University of Macao
文摘This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these changes, we simulate the lighting transportation process at run time, which is normally impractical for interactive use due to its huge computational burden. We greatly alleviate this burden by a hierarchical structure named a transportation tree that clusters similar emitting samples together within a perceptually acceptable error bound. Furthermore, by exploiting the coherence in time as well as in space, we incrementally adjust the clusters rather than computing them from scratch in each frame. With a pre-computed visibility map, we are able to efficiently estimate the indirect illumination in parallel on graphics hardware, by simply summing up the radiance shoots from cluster representatives, plus a small number of operations of merging and splitting on clusters. With relighting based on the time-varying clusters, interactive update of global illumination effects with multi-bounced indirect lighting is demonstrated in applications to material animation and scene decoration.
基金A preliminary version of this paper appeared in Proc. Pacific Graphics 2005, Macao. The work is supported by the National Basic Research 973 Program of China （Grant No. 2002CB312102）, the National Natural Science Foundation of China （Grant Nos. 60373051, 60473105） and the Research Grant of the University of Macao.
文摘Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.
基金the National Science Foundation under grant no.1245847the National Institute of Health under grant no.1R43AI136357-01A1.
文摘With the ever-growing data and the need for developing powerful machine learning models,data owners increasingly depend on various untrusted platforms(e.g.,public clouds,edges,and machine learning service providers)for scalable processing or collaborative learning.Thus,sensitive data and models are in danger of unauthorized access,misuse,and privacy compromises.A relatively new body of research confidentially trains machine learning models on protected data to address these concerns.In this survey,we summarize notable studies in this emerging area of research.With a unified framework,we highlight the critical challenges and innovations in outsourcing machine learning confidentially.We focus on the cryptographic approaches for confidential machine learning(CML),primarily on model training,while also covering other directions such as perturbation-based approaches and CML in the hardware-assisted computing environment.The discussion will take a holistic way to consider a rich context of the related threat models,security assumptions,design principles,and associated trade-offs amongst data utility,cost,and confidentiality.
