面向内容的三维模型数据库设计及其检索系统的实现

目前,对基于内容的三维模型检索的研究主要集中在检索过程所涉及到的算法方面,而对三维模型库的设计研究较少.为此,详细分析了面向内容的三维模型库的建立过程,重点论述三维模型库的组织结构和分类表的设计,提出一种三维模型分类的手工构造方法,开发了三维模型库的管理软件,并研制了三维模型检索的原型系统.其意义在于为三维模型检索研究提供一个结构合理、数据充分的三维模型库,从而为检索算法的研究奠定坚实的基础.     

基于数据集分割的云工作流模型库并行检索方法

在由多个行业云服务平台组成的集成服务平台中,随着行业云服务平台加盟数及各平台下租户数量的不断增多,其底层的云工作流模型库的规模也必将不断增大.当云工作流模型库的规模超大时,需要一种效率更高的并行检索方法去满足云工作流模型库高效检索的需求.鉴于此,文章将采用均匀划分法或自动聚类法对大规模云工作流模型库进行合理的子集划分,并结合前期工作中已改进的基于图结构的流程检索算法,提出基于数据集分割的大规模云工作流模型库并行检索方法.该方法主要包括4种流程并行检索算法：基于均匀划分模型集的静态并行检索算法、基于均匀划分模型集的动态并行检索算法、基于自动聚类模型集的静态并行检索算法及基于自动聚类模型集的动态并行检索算法.最后,在模拟生成的大规模流程集及真实的云工作流模型库中对这4种并行检索算法的检索效率进行实验评估.     

三维CAD模型局部结构检索属性图算法

由用户交互式地选择欲检索的模型局部结构,并自动生成该局部结构的属性图;然后取出三维CAD模型库中每个待检索模型,根据模型的B-rep表示过滤出其中与欲检索局部结构组成面相似的面,通过删除不相关面,有效地将可能相似的局部结构从待检索模型中分离出来;最后利用图论中二分图最优匹配算法计算出模型中分离出的结构和欲检索局部结构的相似系数,并将该相似系数作为实现模型局部相似性检索的依据.实验表明,该算法能够实现CAD模型局部结构检索,并与人视觉上的相似性判断基本一致.     

三维网格模型增量式聚类检索

针对大规模三维网格模型库中的形状检索问题,提出了基于增量式聚类的三维形状描述和检索方法。首先根据三维模型的曲率分布直方图提取特征点得到特征向量;然后根据特征向量描述建立模型库的关键词词典;在特征 匹配阶段基于增量聚类方法判断目标模型的特征向量是否属于某一个关键词,并根据增量聚类的结果更新检索关键词词典;最后匹配特征向量检索模型库中与目标模型形状相同和相近的三维网格模型。相关实验结果证明了该方法快速有效,具有较高的准确性。     

支持动态编译的GIS模型库系统中模型表示方式——图形图元表达、正则表达式及模型运算树

提出模型库系统中模型的三种表达方式——图形图元表达、正则表达式及模型运算树。它们可作为动态生成高效率模型体的有力手段,是模型库系统即时编译生成模型组件的基础。这为解决模型库系统实现过程中模型内容表达这一难题,提供理论基础及解答。最后,在此概念及原理基础上,给出了采用这三种表达方式展现原型系统中范例模型的具体过程。     

基于PyQt5的铸造过程数据管理软件开发

针对铸造行业材质成分数据缺少可靠管理、铸件结构模型难以保存，以及复用、铸件缺陷检测依赖人力三个问题，开发了基于PyQt5的铸造过程数据管理软件。系统由材料成分与性能库、铸件结构与模型库、铸件缺陷识别三部分组成。该管理软件使用Pyinstaller打包成桌面式应用，可在Windows10系统运行，可移植性高。     

遥感图像三维目标多视点建模识别方法

研究利用遥感灰度图像识别三维目标时的问题，提出一种基于多视点模型的匹配识别方法。使用3D广义锥模型投影得到二维视面模型，用于描述不同视点下的目标视面，并用几何结构特征来检索模型库。匹配过程层次地使用全局的与局部的、统计的与结构的目标识别特征，分为检索和精确匹配两个步骤完成。通过实验验证了该方法的有效性。     

基于极限投影变换的3D模型检索

基于认知理论和投影理论,提出极限投影面积方法对三维模型进行坐标标准化:将模型不断绕过模型重心的基向量旋转,采集每次坐标面投影面积,在多次迭代后得到最大面积投影,用同样办法获得另一坐标面上的最小面积投影,建立模型的坐标系.实验结果表明:该方法标准化的坐标系处理对象范围宽,适用于网格模型、点云模型和各类曲面模型,针对模型噪声、简化、攻击等有很强的鲁棒性.经该方法标准化的三维模型在3个坐标面的投影作为模型的特征描述子,并在实验中为实验模型库建立了对应的特征描述子库,使得对模型检索转化为特征描述子间的比较检索.检索实验表明:该方法针对增加了特征描述子的模型库具有较快的检索速度;同时具有较强的鲁棒性,但检索的精度稍差.     

基于检索结果融合机制的对话生成模型

对话生成模型是对话系统中十分重要的组件。传统的对话生成模型仅利用用户的输入信息生成回复,这导致在生成过程中常会出现无意义的万能回复。最近有工作尝试将检索的方法融入生成模型从而提高模型的生成质量,但这些方法往往将重点放在如何编辑检索结果上,没有考虑检索结果与用户查询之间的语义空间差别。为解决这一问题,该文提出了基于检索结果融合的对话生成模型。模型首先利用双向长短时记忆网络对检索结果进行编码,并提出了具有融合机制的长短时记忆网络(fusion-LSTM)。该机制将检索结果在模型内部与对话文本相结合,以更好地将检索到的信息融入到生成模型中。实验结果表明,该方法在自动评价指标和人工评价指标中都明显优于基线方法。     

基于GIS的环境影响评价专题图信息系统

该系统采用了组件式GIS开发方式，运用MapX组件，在VB语言平台下设计开发而成。系统将GIS与环境评价模型库、专题地图进行综合集成，具有信息的图形化生成、显示功能，实现专题地图的动态修改、保存、检索及打印，可广泛应用于环境影响评价工作中。     

Literature review of reuse in business process modeling

Business process models play an important role in the analysis and improvement of the performance of an enterprise. Evidently, the quality of a business process model has a direct effect on the business performance. This evidence has motivated both the academic and industrial communities to look for suitable methods for creating good quality business process models. In particular, there is a wide agreement that reuse can accelerate the design process and produce high quality solutions by adopting best practices and agreed-up-on solutions. However, faced with various types of reusable artifacts, business process designers need a set of criteria to determine which type would suit best their needs and design context. To assist designers in their choice, we first present a set of criteria influencing the design phase in terms of effort required and the quality of the resulting model. Secondly, we use this set of criteria to present a state of the art on the most significant reusable design artifacts.     

The generic model query language GMQL – Conceptual specification,implementation, and runtime evaluation

The generic model query language GMQL is designed to query collections of conceptual models created in arbitrary graph-based modelling languages. Querying conceptual models means searching for particular model subgraphs that comply with a predefined pattern query. Such a query specifies the structural and semantic properties of the model fragment to be returned. In this paper, we derive requirements for a generic model query language from the literature and formally specify the language’s syntax and semantics. We conduct an analysis of GMQL׳s theoretical and practical runtime performance concluding that it returns query results within satisfactory time. Given its generic nature, GMQL contributes to a broad range of different model analysis scenarios ranging from business process compliance management to model translation and business process weakness detection. As GMQL returns results with acceptable runtime performance, it can be used to query large collections of hundreds or thousands of conceptual models containing not only process models, but also data models or organizational charts. In this paper, we furthermore evaluate GMQL against the backdrop of existing query approaches thereby carving out its advantages and limitations as well as pointing toward future research.     

Querying business process model repositories

Business process management technology is becoming increasingly popular, resulting in more and more business process models being created. Hence, there is a need for these business process models to be managed effectively. For effective business process model management, being able to efficiently query large amount of business process models is essential. For example, it is preferable to find a similar or related model to customize, rather than building a new one from scratch. This would not only save time, but would also be less error-prone and more coherent with the existing models of the enterprise. Querying large amounts of business process models efficiently is also vital during company amalgamation, in which business process models from multiple companies need to be examined and integrated. This paper provides: an overview of the field of querying business process models; a summary of its literature; and a list of challenges (and some potential solutions) that have yet to be addressed. In particular, we aim to compare the differences between querying business process models and general graph querying. We also discuss literature work from graph querying research that can be used when querying business process models.     

Business process design: Process comparison and integration

This paper proposes a framework for business process design, which is based on process comparison and integration. This framework supports process stakeholders to model business processes collaboratively, which can greatly enhance the efficiency and effectiveness of business process design. By applying this framework, each process stakeholder can create his or her own model of the business process. The different models of the same business process can be automatically compared to find the conflicts between them. Based on the conflicts, process stakeholders can collaborate to improve the models. Then the models can be integrated to form a more complete model.     

一种适合于电子政务中业务处理的过程模型

目前，电子政务系统一般通过业务过程模型支持电子政务业务处理，而当前已有的业务过程模型在灵活性和安全性方面尚存在不足。为此，提出了一种适合于电子政务中业务处理的过程模型，它将多变的业务规则从过程流中分离出来，通过耦合机制实现业务规则与过程流的结合。该模型简化了过程流的定义，使过程流的变更相对容易，而且可以在不改变过程流的情况下独立、便捷地维护业务规则，确保业务处理的安全性。最后给出了一个使用该模型的电子政务业务处理应用实例。     

面向重构的企业应用系统业务模型

在分析面向重构的设计原则的基础上,提出一种基于业务规则的业务模型,并给出八类规则的表达形式。通过对业务元素的持续分解,将模型中频繁发生变化的部分分离出来并使用规则表达,提高了业务模型的动态性和灵活性。最后研究了基于该业务模型的建模过程。     

Optimal business process deployment cost in cloud resources

Cloud computing is the fastest emerging technology that proposes several resources under various pricing strategies that are specified based on temporal constraints. The main aim of cloud computing is to enhance the performance level and minimize operating costs. Thus, organizations looking towards optimizing their spending on IT infrastructure find such pricing strategies very attractive, especially, to deploy their business process models. However, discovering the optimal deployment cost of a business process in cloud resources proposed under various pricing strategies becomes a highly challenging problem. So, the objective of the present paper is to present an approach that assists business process designers in finding an optimal assignment or scheduling based on the variety of pricing strategies. We use linear programming models with an objective function under a set of constraints. Besides, we propose an extension of the famous cloud simulator provided in the market, CloudSim, to simulate the cloud resources consumed to deploy a business process model. The experimental results show the feasibility, effectiveness, and performance of our approach.

     

基于图形展开及图形归约的过程模型验证方法

工作流过程模型是业务过程的形式化定义，在业务过程的分析、运行和重组方面起着关键性的作用．为了实现预期的业务目标，需要正确地定义工作流过程模型，它的正确性直接影响业务目标的实现，WfMS开始调度执行之前必须对其进行分析．针对大规模复杂应用的特点和业务过程执行的实际需要，对复杂工作流过程模型的正确性验证进行了研究；基于有向有环图(DCG图)详细讨论工作流过程模型的局部错误以及过程逻辑错误；给出了过程建模中避免错误的相关约束规则；另外了提出了一种新型的图形归约和图形展开相结合的验证方法及过程模型验证算法．     

基于Hadoop的业务过程模型管理方法研究

目前现有业务过程模型研究的共同特点便是基于单机环境来构建业务过程库,并基于传统关系数据库来管理业务过程模型,完成相关的检索、存储等操作。为提高大规模业务过程模型检索与存储的效率,本文提出一种新的业务过程模型管理方法。该方法采用基于Hadoop大数据处理平台对业务过程模型进行管理,并采用Map/Reduce编程框架和HDFS文件系统分别对业务过程模型进行检索和存储,提高了业务过程模型存储效率,减少了模型检索匹配的时间。通过原型系统进行试验验证评估,证明了所提方法在存储和检索效率方面高于单机环境。