Detection and resolution of conflicting change operations in version management of process models

Version management of process models requires that different versions of process models are integrated by applying change operations. Conflict detection between individually applied change operations and conflict resolution support are integral parts of version management. For conflict detection it is utterly important to compute a precise set of conflicts, since the minimization of the number of detected conflicts also reduces the overhead for merging different process model versions. As not every syntactic conflict leads to a conflict when taking into account model semantics, a computation of conflicts solely on the syntax leads to an unnecessary high number of conflicts. Moreover, even the set of precisely computed conflicts can be extensive and their resolution means a significant workload for a user. As a consequence, adequate support is required that guides a user through the resolution process and suggests possible resolution strategies for individual conflicts. In this paper, we introduce the notion of syntactic and semantic conflicts for change operations of process models. We provide a method how to efficiently compute conflicts precisely, using a term formalization of process models and consider the subsequent resolution of the detected conflicts based on different strategies. Using this approach, we can significantly reduce the number of overall conflicts and reduce the amount of work for the user when resolving conflicts.     

航空器轨迹预测技术研究综述

航空器轨迹预测是流量管理、冲突检测和解脱、航空器进场排序以及异常行为监测等空中交通管理技术的基础。关于航空器轨迹预测的研究产生了许多经典的方法和应用领域。对研究航迹预测问题的背景和意义进行概述,并从数据库、基础流程和预测关键技术三个方面介绍了有关航迹预测的基础知识。其中数据库包括航空器性能数据库、航空器监视数据库和气象数据库,基础流程包括准备、预测、更新和输出四个模块,预测关键技术总结并列举了状态估计模型、动力学模型和机器学习模型三类方法的典型模型。对航迹预测系统模型进行具体分析时,进一步列举三类方法的主要研究成果并归纳各类方法的特点。对航迹预测在空中交通管理中的具体应用进行分析,包括冲突检测、到达管理和流量管理等。总结并指出了目前航迹预测问题所面临的挑战和未来的发展方向。     

Distributed conflict resolution among cooperating expert systems

Abstract: Cooperating experts approach attempts to integrate and coordinate the activities of multiple specialised problem solvers that come together to solve complex tasks such as design, medical diagnosis, business management and so on. Due to the different goals, knowledge and viewpoints of agents, conflicts may arise at any phase of the problem-solving process. Managing diverse expertise requires well-organised models of conflict resolution. In this paper, a model for cooperating experts is described which openly supports multi-agent conflict detection and resolution. The model is based on the idea that each agent has its own conflict knowledge which is separated from its domain level knowledge, and each agent has its own conflict resolution knowledge which is not accessible and known by others. Furthermore, there are no globally known conflict resolution strategies. Each agent involved in a conflict chooses a resolution scheme according to its self interest. The model is described by using an example in the domain of office design and it is compared with other systems.     

Edge enhancement by local deconvolution

In this paper a new approach for blurred image restoration is presented. Our algorithm is based on human vision which zooms back and forth in the image in order to identify global structures or details. Deconvolution parameters are estimated by an edge detection and correspond to the ones of a chosen edge detection model. The segmentation is obtained by merging multiscale information provided by multiscale edge detection. The edge detection is achieved by using a derivative approach following a generalization of Canny-Deriche filtering. This multiscale analysis performs an efficient edge detection in noisy blurred images. The merging leads to the best local representation of edge information across scales. The algorithm deals with a mixed (coarse-to-fine/fine-to-coarse) approach and searches for candidate edge points through the scales. Edge characteristics are estimated by the merging algorithm for the chosen model. Scale, direction and amplitude informations allow a local deconvolution of the original image. The noise problem is not considered in this work since it does not disturb the process. Results show that this method allows non-uniformly blurred image restoration. An implementation of the whole algorithm in an intelligent camera (DSP) has been performed.     

Software merge: Models and methods for combining changes to programs

We outline a model for programs and data and present a formal definition of an ideal change merging operation. This model is used to develop a new semantically based method for combining changes to programs. We also evaluate the appropriateness of the change merging operation and examine some circumstances where the specifications of a program as well as the implementations can be used to guide the change merging process in cases where the implementations conflict but the specifications do not. This work was performed for the Office of Naval Research and funded by the Naval Postgraduate School.     

基于Delaunay三角网的模型拼合算法研究

模型拼合在地理建模、铁(公)路路线三维设计等领域应用十分广泛，研究如何快速高效地获得拼合模型的算法很有必要。基于Delaunay三角网模型的拼合算法，提出了一种快速获取模型拼合交线的方法和快速搜索交线范围内三角形的算法，采取拼合交线入网及初始D-三角网的裁剪2个关键步骤来实现D-三角网模型拼合。对模型拼合的整个过程进行了详细的阐述，采用VC^ 6．O语言实现了算法，并利用实验数据对算法进行测试，验证了算法的正确性与可行性。     

协同工作中冲突消解机制的研究

协同工作就是利用网络技术众多设计者共同合作完成任务,及时更新信息,保证网络信息的一致性与快速响应性。但是在协同工作过程设计成员自身条件差异,不可避免在协同设计中会产生冲突,所以准确及时对冲突检测与消解是协同工作的关键。因此提出一种新的集成化冲突消解模型,给出模型算法,利用模式匹配技术在这个模型中进行冲突检测与消解,采用克莫普匹配法进行冲突消解。通过实验证明,集成化模型和模式匹配技术很有效,对冲突检测准确,对冲突消解效率高,尤其处理大批量冲突时速度很快。效果非常显著,算法复杂度也很低。     

基于数据挖掘的建筑能耗异常检测研究

建筑能耗异常检测对于建筑管理和运行至关重要,论文提出了一种基于D-S证据理论的不平衡数据多划分(Multi-partition,MP)聚类算法,并构建MP算法能耗异常检测模型对建筑能耗中的异常值进行准确检测。首先通过改进的信任c均值算法将能耗数据集多划分；利用基于K-NN的均值漂移算法确定数据集的真实类别个数；然后根据密度合并规则对能耗数据进行合并；最后对未合并的能耗数据再次划分得到最终的能耗异常检测结果。UCI数据集验证结果表明,MP算法对于不平衡数据聚类效果良好,能够有效避免样本“均匀效应”,降低错误率；通过对某大型商场建筑空调和照明用电能耗异常值检测,验证了MP算法能耗异常检测模型的有效性。     

Fast detection of exact clones in business process model repositories

As organizations reach higher levels of business process management maturity, they often find themselves maintaining very large process model repositories, representing valuable knowledge about their operations. A common practice within these repositories is to create new process models, or extend existing ones, by copying and merging fragments from other models. We contend that if these duplicate fragments, a.k.a. exact clones, can be identified and factored out as shared subprocesses, the repository's maintainability can be greatly improved. With this purpose in mind, we propose an indexing structure to support fast detection of clones in process model repositories. Moreover, we show how this index can be used to efficiently query a process model repository for fragments. This index, called RPSDAG, is based on a novel combination of a method for process model decomposition (namely the Refined Process Structure Tree), with established graph canonization and string matching techniques. We evaluated the RPSDAG with large process model repositories from industrial practice. The experiments show that a significant number of non-trivial clones can be efficiently found in such repositories, and that fragment queries can be handled efficiently.     

基于混合人工免疫算法的流程挖掘事件日志融合方法

流程挖掘是流程管理和数据挖掘交叉领域中的一个研究热点.在实际业务环境中,流程执行的数据往往分散记录到不同的事件日志中,需要将这些事件日志融合成为单一事件日志文件,才能应用当前基于单一事件日志的流程挖掘技术.然而,由于流程日志间存在着执行实例的多对多匹配关系、融合所需信息可能缺失等问题,导致事件日志融合问题具有较高挑战性.本文对事件日志融合问题进行了形式化定义,指出该问题是一个搜索优化问题,并提出了一种基于混合人工免疫算法的事件日志融合方法：以启发式方法生成初始种群,人工免疫系统的克隆选择理论基础,通过免疫进化获得“最佳”的融合解,从而支持包含多对多的实例匹配关系的日志融合;考虑两个实例级别的因素：流程执行路径出现的频次和流程实例间的时间匹配关系,分别从“量”匹配和“时间”匹配两个维度来评价进化中的个体;通过设置免疫记忆库、引入模拟退火机制,保证新一代种群的多样性,减少进化早熟几率.实验结果表明,本文的方法能够实现多对多的实例匹配关系的事件日志融合的目标,相比随机方法生成初始种群,启发式方法能加快免疫进化的速度.文中还针对利用分布式技术提高事件日志融合性能,探讨了大规模事件日志的分布式融合中的数据划问题.     

业务过程建模中冲突消解的研究

业务过程建模是整个工作流管理的基础,在工作流执行之前,需要对业务过程模型进行分析和检测,对含有冲突的模型进行冲突消解,以协助建模人员修改业务过程模型。介绍了冲突的体系结构,对近年来在冲突消解方面的研究进行论述,并提出了含有二级检测机制的冲突消解工具结构,为业务过程模型的分析提供依据。     

一种实化视图的合并算法

对于拥有大量实化视图的实际数据库应用系统,提出了视图合并的方法以减少整个视图 的数量,缩减实化视图的搜索空间;还提出了归并树和基于归并树的快速有效的合并算法。实验表 明,实化视图的合并是快速寻找可能响应查询的实化视图的一种有效途径,可以显著改进查询处理的 性能。     

A fundamental approach to model versioning based on graph modifications: from theory to implementation

In model-driven engineering, models are primary artifacts that can evolve heavily during their life cycle. Therefore, versioning of models is a key technique to be offered by integrated development environments for model-driven engineering. In contrast to text-based versioning systems, we present an approach that takes model structures and their changes over time into account. Considering model structures as graphs, we define a fundamental approach where model revisions are considered as graph modifications consisting of delete and insert actions. Two different kinds of conflict detection are presented: (1) the check for operation-based conflicts between different graph modifications, and (2) the check for state-based conflicts on merged graph modifications. For the merging of graph modifications, a two-phase approach is proposed: First, operational conflicts are temporarily resolved by always giving insertion priority over deletion to keep as much information as possible. Thereafter, this tentative merge result is the basis for manual conflict resolution as well as for the application of repair actions that resolve state-based conflicts. If preferred by the user, giving deletion priority over insertion might be one solution. The fundamental concepts are illustrated by versioning scenarios for simplified statecharts. Furthermore, we show an implementation of this fundamental approach to model versioning based on the Eclipse Modeling Framework as technical space.     

基于Kinect的深度数据融合方法

与传统三维激光扫描仪相比, Kinect作为一种新型深度相机, 具有价格低廉、深度数据获取能力强、RGB影像与深度影像同步获取等优势, 然而面对较大室内场景精细建模却存在数据量大、建模范围有限、对硬件环境依赖性强等问题。因此, 在现有单一模型建模基础上, 提出了基于Kinect深度影像的多模型数据融合方法, 实现模型间的自动拼接。最后通过两组实验对提出的数据融合方法进行了验证, 并取得了较好的模型拼接效果。     

一类模糊模型的结构优化问题研究

提出了将模糊模型统计信息准则（FSIC）、基于奇异值分解（SVD）的模糊模型结构分析、模糊规则删除与合并、参数估计等方法集成的模糊模型结构迭代优化。研究表明,将SVD引入到模糊模型结构分析、结合FSIC指导模糊规则删除和合并,可从模型结构精简化、模型拟合和泛化性能等方面综合地确定最优模型结构;文中提出了实用可行的基于聚类加权组合和多重模糊聚类的规则合并算法。该迭代优化方法已成功地应用于非线性函数逼近和航空煤油干点估计器的模糊模型构造。仿真结果表明文中提出的方法简单实用,优化的模型结构比文献中给出的模型结构更加精简。     

Automated merging of software prototypes

As software becomes more complex, more sophisticated development and maintenance methods are needed to ensure software quality. Computer-aided prototyping achieves this via quickly built and iteratively updated prototypes of the intended system. This process requires automated support for keeping track of many independent changes and for exploring different combinations of alternative changes and refinements. This article formalizes the update and change merging process, extends the idea to multiple changes to the same base prototype, and introduces a new method of slicing prototypes. Applications of this technology include automatic updating of different versions of existing software with changes made to the baseline version of the system, integrating changes made by different design teams during development, and checking consistency after integration of seemingly disjoint changes to the same software system.     

A high‐performance sorting algorithm for multicore single‐instruction multiple‐data processors

Many sorting algorithms have been studied in the past, but there are only a few algorithms that can effectively exploit both single‐instruction multiple‐data (SIMD) instructions and thread‐level parallelism. In this paper, we propose a new high‐performance sorting algorithm, called aligned‐access sort (AA‐sort), that exploits both the SIMD instructions and thread‐level parallelism available on today's multicore processors. Our algorithm consists of two phases, an in‐core sorting phase and an out‐of‐core merging phase. The in‐core sorting phase uses our new sorting algorithm that extends combsort to exploit SIMD instructions. The out‐of‐core algorithm is based on mergesort with our novel vectorized merging algorithm. Both phases can take advantage of SIMD instructions. The key to high performance is eliminating unaligned memory accesses that would reduce the effectiveness of SIMD instructions in both phases. We implemented and evaluated the AA‐sort on PowerPC 970MP and Cell Broadband Engine platforms. In summary, a sequential version of the AA‐sort using SIMD instructions outperformed IBM's optimized sequential sorting library by 1.8 times and bitonic mergesort using SIMD instructions by 3.3 times on PowerPC 970MP when sorting 32 million random 32‐bit integers. Also, a parallel version of AA‐sort demonstrated better scalability with increasing numbers of cores than a parallel version of bitonic mergesort on both platforms. Copyright © 2011 John Wiley & Sons, Ltd.     

改进的多传感器数据统一算法

为了避免多传感器获得的数据在物体相同部分存在重叠的问题,提出了一种基于2维网格处理的多传感器数据统一算法。该算法通过对等值面点数据依次进行改进的2维Delaunay三角剖分、顶点删除法网格简化、三角片取重心、数据整合及采样等操作,实现了多传感器数据的统一。对实验室激光3维人体扫描系统获得的人体数据进行的实际处理结果表明,该算法具有处理速度快、操作简便、能有效删除噪声等优点。     

一种面向软件产品概念设计的CSCW模型

随着计算机和网络技术的发展,各种CSCW模型和技术先后被提出,来满足各行业产品和概念设计的复杂工作需求。软件产品的概念设计作为一项复杂的工作和业务流程,对CSCW系统的需求也越来越高。文中针对软件产品概念设计的特殊性质,提出一种新的CSCW软件产品概念设计模型,并且对其中包含的冲突检测和协调机制进行了详细的设计和优化。使用基于Java平台的相关技术对模型主要功能架构和冲突协调过程进行了仿真。实验表明,文中提出的模型具有更加简洁和高效的复杂冲突解决能力和用户交互能力。     

部件化构建的三维服装快速编辑方法

直接设计一个三维服装模型不仅耗时而且需要专业服装设计知识。为简化这一复杂 的建模过程,提出基于部件化构建的三维服装快速编辑方法,其关键在于通过分割和融合的网格 编辑技术从已有的服装模型中快速构建新的三维服装模型。首先按照服装分类分割出不同类型的 服装部件。其次基于分割出的三维服装部件以及已有的服装模型,建立部件间以及部件与模型间 的几何约束关系,把二维均值坐标插值方法应用到三维服装网格融合中,把方程数值求解问题转 化为线性插值问题,避免求解线性方程组。最后根据柔性服装的特征,构造适于柔性服装光滑保 形变换的方法。实验结果表明,该算法在不影响融合效果的前提下可以提高融合的效率,能够有 效地实现三维服装的快速编辑。