利用球谐方法分散计算场景的全局光照

作为一种特殊的光照模型,辐射度在图形学中有着重要的应用.然而,由于其计算的复杂性,辐射度方法一直得不到广泛的应用,特别是在动态场景中.提出一种基于辐射度算法的全局光照实时加速算法,在原有基于点采样进行场景的全局光照近似的基础上,提出了不同的点采样计算方法,以提高辐射度方法对动画场景的适应性.算法对场景中的物体建立六面体包围盒,并在包围盒各顶点设置采样点,这样就可以在环境变化对其光照影响不大的情况下采用原有的计算结果,实现辐射度算法在动态场景中的计算加速.同时,对场景中的每个物体的光照,利用立方体映射计算直接光照;而对物体间的能量交换采用点采样方法进行近似计算并利用附近采样点的光照插值作为物体的光照.实验结果表明,该算法可以减少大量的间接光照计算,提高了辐射度算法的效率.     

Transformation of Function Block Diagrams to UPPAAL timed automata for the verification of safety applications

Verification of IEC 61131-3 based safety applications is a challenge in the industrial automation domain. In this paper, the transformation of FBD diagrams to UPPAAL formal models was adopted to address this challenge. A set of transformation rules are defined for the automatic transformation of IEC 61131-3 Function Block based safety applications to UPPAAL timed automata models. These models are next used for the verification of the safety application. Both the source and the target domain models have been formally defined and these definitions are used for the definition of the transformation rules. Based on this a prototype model transformer was developed using Java. The transformer was used with various safety applications to check the efficiency of the transformation process. A laboratory system is presented as a case study to highlight the proposed approach.     

一种物联网智能数据采集系统的研究与实现

设计并实现了基于CANBus的智能数据采集系统.系统主要由主站与从站2个部分组成.主站以S3C6410为核心处理器,运行WindowsCE;从站以STM32为核心处理器.S3C6410、STM32与CANBus的搭配及以此为基础的应用层协议赋予了此系统智能性.运用马尔可夫决策模型对系统的状态进行了描述,同时对系统协议的正确率进行了估算.该系统是物联网底层数据采集技术的一种实现方案.     

基于聚类的动态社交网络隐私保护方法

由于社交网络图结构的动态变化特性,需要采用有效的动态隐私保护方法。针对现有动态数据发布隐私保护方法中存在的攻击者背景知识单一、对图结构动态变化适应性较低等问题,提出基于聚类的动态图发布隐私保护方法。分析表明,该方法能抵御多种背景知识攻击,同时对社交网络图结构动态变化具有较好的适应性。     

A systematic review on regression test selection techniques

Regression testing is verifying that previously functioning software remains after a change. With the goal of finding a basis for further research in a joint industry-academia research project, we conducted a systematic review of empirical evaluations of regression test selection techniques. We identified 27 papers reporting 36 empirical studies, 21 experiments and 15 case studies. In total 28 techniques for regression test selection are evaluated. We present a qualitative analysis of the findings, an overview of techniques for regression test selection and related empirical evidence. No technique was found clearly superior since the results depend on many varying factors. We identified a need for empirical studies where concepts are evaluated rather than small variations in technical implementations.     

凝血系统中蛋白C抑制模型的时间周期解(英文)

蛋白C的抑制作用对凝血系统是非常重要的.讨论一类含非齐次项的凝血系统,利用Galerkin方法和Leray-Schauder不动点定理得到了时间周期解的存在性.     

The simulation model partitioning problem: An adaptive solution based on self-Clustering

This paper is about partitioning in parallel and distributed simulation. That means decomposing the simulation model into a number of components and to properly allocate them on the execution units. An adaptive solution based on self-clustering, that considers both communication reduction and computational load-balancing, is proposed. The implementation of the proposed mechanism is tested using a simulation model that is challenging both in terms of structure and dynamicity. Various configurations of the simulation model and the execution environment have been considered. The obtained performance results are analyzed using a reference cost model. The results demonstrate that the proposed approach is promising and that it can reduce the simulation execution time in both parallel and distributed architectures.     

Novel Ω-protocols for NP

Ω-protocols, introduced by Garay, Mackenzie and Yang, is a variant of S-protocols with online extractor which is a useful tool to overcome the nest effect in concurrent scenario. In this work, we construct an Ω-protocol for Hamiltonian cycle problem, and therefore, it allows us to present Ω-protocol for any NP relation. For most general NP relations, our construction of Ω-protocols is much more efficient than the informal one described by Garay et ah and we believe that the method for our construction may be of independent interest.     

40 Gbit/s全光异或门性能仿真

为了提高基于SOA-MZI结构的全光异或门的输出消光比,优化系统性能,将SOA和HNLF相结合,在光通信系统设计软件OptiSystem7.0仿真平台上搭建了基于SOA-MZI的全光异或仿真实验模型,对两路40 Gbit/s的RZ码数据信号进行了全光异或仿真实验。利用HNLF的非线性效应设计了一种优化结构对基于SOA-MZI的全光异或输出信号进行优化,并对优化前后的信号时域波形图和系统眼图进行了比较分析,通过多次反复实验得到一组最佳的系统参数,使得基于SOA-MZI的全光异或门的输出消光比从10 dB提高到约28 dB。实验结果表明:常规的基于SOA-MZI的全光异或门由于相消干涉不彻底造成输出消光比较低,而经过优化,很好地解决了这种问题,提高了异或输出消光比,优化了系统性能。