Applications of group technology in distributed manufacturing

This paper discusses the systematic use of group technology (GT) to support important activities of distributed manufacturing including design indexing and retrieval, variant design, variant process planning, and design critiquing. We introduce an Object-Oriented Group Technology (OOGT) scheme, which captures design data critical to the product's manufacture. Our approach uses a STEP-based product information model to generate the OOGT data automatically. The latter are then used to conduct an efficient search for similar products manufactured by selected companies and to retrieve and use information about the manufacturing processes and performance of these similar products.     

图像数据的结构化协同标注与检索

通过分析图像数据对语义信息的检索需求,提出一种表达图像信息的结构化方法,并定义一种根据图像中隐含语义信息来判定相似度的算法。该方法在一定程度上克服了基于内容的图像检索和基于文本的元数据图像检索这2种常用图像检索方法缺乏语义信息匹配上的不足。原型系统根据结构化协同标注中语义信息的丰富程度与图像检索的精确程度,证明了该方法的有效性。     

Knowledge conceptualization tool

Knowledge acquisition is one of the most important and problematic aspects of developing knowledge-based systems. Many automated tools have been introduced in the past, however, manual techniques are still heavily used. Interviewing is one of the most commonly used manual techniques for a knowledge acquisition process, and few automated support tools exist to help knowledge engineers enhance their performance. The paper presents a knowledge conceptualization tool (KCT) in which the knowledge engineer can effectively retrieve, structure, and formalize knowledge components, so that the resulting knowledge base is accurate and complete. The KCT uses information retrieval technique to facilitate conceptualization, which is one of the human intensive activities of knowledge acquisition. Two information retrieval techniques employing best-match strategies are used: vector space model and probabilistic ranking principle model. A prototype of the KCT was implemented to demonstrate the concept. The results from KCT are compared with the outputs from a manual knowledge acquisition process in terms of amount of information retrieved and the process time spent. An analysis of the results shows that the process time to retrieve knowledge components (e.g., facts, rules, protocols, and uncertainty) of KCT is about half that of the manual process, and the number of knowledge components retrieved from knowledge acquisition activities is four times more than that retrieved through a manual process     

Indexing and retrieval in machining process planning using case-based reasoning

To reduce the manufacturing time of a product, one effective way to develop a machining process plan for a new part is to retrieve a relevant case of process planning similar to a new desired part and then adapt the retrieved case to meet the new requirements. This paper proposes a mechanism for retrieval of process planning cases. The core of the retrieval mechanism contains: (1) a feature-based representation of a part and cutting processes; (2) indexing of a part; (3) a feature hierarchical structure based on cutting processes; and (4) a similarity metric used to measure the similarity between a new desired part and any old part in the case base. The application domain here is for axisymmetric part machining. A prototype based on the retrieval mechanism is implemented on a Sun workstation using the ACIS 3D-Toolkit from Spatial Technology Inc.     

基于多Agent的中文智能检索模型

Internet已经成为全球信息系统，如何智能地在这个系统中对信息进行检索一直是热点问题。分布式人工智能的发展和Agent在各个领域的广泛应用，为这个问题的解决提供了技犬上的支持。提出了一种基于多Agent的搜索模型，此模型可以根据不同需求进行信息的智能检索。     

分布式集成信息系统中知识检索方法

支持产品设计的分布式集成信息系统中知识库是系统的核心,如何准确检索到所需知识对系统运行性能有重要影响.文章通过将人工神经网络、模糊理论和规则推理相结合提出了快速、有效的知识检索方法,并探讨了知识分层问题,以支撑件知识检索为对象开发了知识检索原型系统.文章旨在探讨一种合理、有效、快速的知识检索方法,为分布式集成信息系统的成功运行提供性能保障.     

电力企业的非结构化数据检索研究

电网公司多年来建设了很多业务系统,各业务系统相互孤立应用.随着企业信息化建设的深入,业务系统中数据特别是非结构化数据的数据量急剧增长,人员查找数据信息极为不便.建设面向整个电网公司的分布式非结构化数据检索平台,该平台在Linux计算机集群上部署Hadoop开发框架以及Solr分布式全文检索系统,将各业务系统中的非结构化数据进行集中式的存储、管理,并且提供统一的搜索服务,使得企业相关人员能够高效、便捷地检索出所需的数据.实现知识服务无处不在,为员工工作提供帮助,为企业提供决策支持.     

Designing a new model of distributed quality control for sub-assemble products based on the intelligent web information system

The quality control of sub-assemble products (SAP) in a distributed manufacturing shop (DMS) becomes crucial and complicated when the production of SAPs involves a variety of production technology. In this case, traditional statistical process control methods are not sufficient to control such manufacturing system. Here, we design an intelligent web information system, where quality data are collected from DMS and stored in the central database. The processes of manufacturing SAPs in DMS are then controlled by clustering homogenous SAPs using the quality control of SAP in DMS (QCSD) and process smoothness factor based SAP predefined clustering (PSFSPC) algorithms, respectively. A prototype system called an intelligent web information system quality control (IWIS-QC) has been developed to trace the quality profiles of SAPs. Finally, a case study has been presented to illustrate and validate the proposed approach.     

远程分布式数据库动态图像信息检索系统设计

在社会日益多元化的今天,对于数据库的动态图像信息检索的性能要求也越来越严格。传统的图像信息检索系统存在检验图像完好率与检索图像准确率方面较差、检索的速度较慢等问题,已经不能满足当下人们对图像信息检索的需求,为此,提出了一种远程分布式数据库动态图像信息检索系统设计。首先根据远程分布式数据库的特点,设计出了动态图像的检索硬件系统框图;然后基于动态图像特征检索算法对软件进行了设计;最后进行了对比的实验。实验结果证明,该系统设计具有分布性广、通信良好以及稳健性较强的优点,检验图像完好率与检索图像准确率较高,速度较快,适应分布式的管理模式对机构进行控制,在经济上的性能也比较优越,可靠性与可用性较强,扩展性能极好,有益于多图像的共同检索。     

Combining heterogeneous sources in an interactive multimedia content retrieval model

Interactive multimodal information retrieval systems (IMIR) increase the capabilities of traditional search systems, by adding the ability to retrieve information of different types (modes) and from different sources. This article describes a formal model for interactive multimodal information retrieval. This model includes formal and widespread definitions of each component of an IMIR system. A use case that focuses on information retrieval regarding sports validates the model, by developing a prototype that implements a subset of the features of the model. Adaptive techniques applied to the retrieval functionality of IMIR systems have been defined by analysing past interactions using decision trees, neural networks, and clustering techniques. This model includes a strategy for selecting sources and combining the results obtained from every source. After modifying the strategy of the prototype for selecting sources, the system is re-evaluated using classification techniques. This evaluation compares the normalised discounted cumulative gain (NDCG) measure obtained using two different approaches: the multimodal system using a baseline strategy based on predefined rules as a source selection strategy, and the same multimodal system with the functionality adapted by past user interactions. In the adapted system, a final value of 81,54% was obtained for the NDCG.     

An architecture for an intelligent support system for design validation and manufacturing of aerospace components

This paper presents the architecture of a multi‐agent system that aims to support the design and manufacturing processes of composite material components for the aerospace, automobile, ship and other industries. The major goals are to accelerate the design process while minimising cost; support users in selecting the optimum material in terms of its properties, cost and environmental impact; and enhance the efficiency of the component manufacturing phase by extending the decision support capabilities of the existing real‐time monitoring software. An important requirement for achieving these objectives is to enable the more efficient utilisation of existing distributed information on composite materials. To this end, state‐of‐the‐art advances in metadata concepts were adopted and extended. By implementing metadata structures for each data category available, the searching and retrieval mechanisms are improved both in terms of speed and usage. In addition, large amounts of knowledge about the design and manufacturing processes themselves are incorporated into a multi‐agent environment in order to enhance the ability to support the user groups involved in the various stages of component design and manufacturing. In order to present the system architecture here, an example from the aerospace industry has been used.     

面向海量水利数据的索引方法研究

水利数据的存储形式多样、数据量庞大以及水利实体种类丰富,针对每一类水利实体对象,不仅存在基础描述信息,也存在一系列测量业务信息,这2类数据存储和更新频率不相同。水利业务检索不仅要求能实现对象基础信息的快速检索,还要求根据基础描述信息和业务信息之间的依赖进行组合查询,而目前云环境中,尚缺能满足此类兼顾多类型数据之间依赖关系的高效索引方法。此外,水利数据量的急剧增长,给系统检索性能带来了巨大的挑战。为此,本文提出基于Hadoop的分布式双层索引结构HRB,针对不同的数据类型建立不同的索引。经实验验证,HRB索引与常规分布式索引相比,索引创建效率更优,且在数据量达到千万级别时,HRB检索速度更快,表明HRB具有一定的使用价值。     

数据库技术在模糊聚类预测中的应用研究

将数据库技术应用于模糊聚类预测中，用ＦＯＸＰＲＯ开发了模糊聚类预测软件，通过对上海水泥厂提供的实测数据的实旆计算，取得了令人满意的结果，文中提供的方法具有普遍的意义和广阔的应用前景，作为数据库技术原应用开辟了新领域。     

Query relaxation by structure and semantics for retrieval oflogical Web documents

Since the Web encourages hypertext and hypermedia document authoring (e.g., HTML or XML), Web authors tend to create documents that are composed of multiple pages connected with hyperlinks. A Web document may be authored in multiple ways, such as: (1) all information in one physical page, or (2) a main page and the related information in separate linked pages. Existing Web search engines, however, return only physical pages containing keywords. We introduce the concept of information unit, which can be viewed as a logical Web document consisting of multiple physical pages as one atomic retrieval unit. We present an algorithm to efficiently retrieve information units. Our algorithm can perform progressive query processing. These functionalities are essential for information retrieval on the Web and large XML databases. We also present experimental results on synthetic graphs and real Web data     

基于分布RDF(S)模型的信息查询与集成

在Web应用环境中,可以通过RDF(S)形式描述企业领域内分布信息资源的语义,以提高信息查询的准确性.提出了描述分布异构RDF(S)的分布RDF(S)模型,并基于这一模型给出了实现分布RDF(S)查询的方法,此查询方法既能实现实例层次的查询,也能实现概念层次的查询.基于这一方法,用户能够以统一的形式来查询,获取相关的信息资源,同时还可以实现分布RDF(S)的集成.     

分布式海量遥感影像编目检索机制

为了高效地组织、检索分布式海量遥感数据,研究FGDC制定的遥感元数据标准草案,提出一种具有良好可扩展性的遥感编目数据模型。基于该编目数据模型,提出一种基于编目数据的分布式影像检索算法,设计并实现一个遥感数据编目检索系统,实验结果表明,该系统是有效的。     

Application of group technology for design data management

Group Technology (GT) as a manufacturing philosophy plays a major role in design standardization, manufacturing cell layouts, process planning, purchasing, and manufacturing technology systems design. One of the most effective ways to use GT is to facilitate significant reductions in design time and effort. A design engineer faced with the task of developing a new part design must either start from scratch or obtain an existing drawing from the files and make the necessary changes to conform to the requirements of the new part. The problem of finding a similar design is quite difficult and time consuming for large engineering departments. The objectives of this research are to develop a classification and coding system for rapid design retrieval of all design data pertaining to the manufacturing of machine tools. This paper proposes and details five steps in the development of group technology databases: 1) data collection, 2) data classification, 3) data analysis, 4) data coding, and 5) data querying. This paper also develops a software prototype written in C language called Interactive Design Retrieval System (IDRS) which assists in an efficient design retrieval process. The proposed prototype also facilitates efficient design data management. In conclusion, an assessment and extension of the results are provided.     

基于实例的产品设计知识获取方法及实现

现代产品设计是面向市场、功能驱动以及基于新知识的设计，而知识获取是关键步骤。采用设计实例的形式对已有设计进行封装和组织，通过产品设计实例面向对象表达模型，将设计需求（包括性能需求、环境约束和成本约束）、设计任务、设计过程和设计方案封装在一个设计实例中，体现了功能驱动、面向市场的现代设计特征。在此基础上，利用Sybase公司的PowerDesigner8.0建模工具，进一步提出产品设计实例的获取模型，并对实例获取的关键技术进行了讨论。以滑动轴承设计为工程应用背景，选择应用于涡轮机的四油叶径向滑动轴承为设计实例，详细描述了集成于SolidWorks2000的滑动轴承设计实例获取模块的应用过程，验证了上述模型的正确性和可行性。通过对设计实例进行表达、获取和存储，为后续的基于实例推理的产品设计方法打下基础，同时以对外提供功能的形式对并行设计环境下的功能检索提供支持，推动现代产品概念设计自动化进程。