A concurrent engineering-oriented design database representation model

A concurrent engineering-oriented design database representation model (CE-DDRM) is introduced in this research for supporting various life-cycle aspects in concurrent design. In this model, concepts and behaviors of different design database modeling components, including entities, properties, relationships, tasks, and specifications, are defined at meta-class level. Design database is modeled at two different levels, class level and instance level, representing generic design libraries and special design cases, respectively. A Web-based system architecture is proposed to model distributed design database and allow team-members for different product development life-cycle aspects at different locations to access the design database. This newly introduced approach provides the foundation for developing the next generation CAD systems with concurrent engineering functions.     

Optimal concurrent design based upon distributed product development life-cycle modeling

This research introduces an optimal concurrent design approach based upon a previously developed distributed product development life-cycle modeling method. In this approach, the product realization process alternatives and relevant activities are modeled at different locations that are connected through the Internet. Relations among these alternative activities are described by an AND/OR graph. The optimal product realization process alternative and its parameter values are identified using a multi-level optimization method. Genetic programming (GP) and particle swarm optimization (PSO) are employed for identifying the optimal product realization process alternative and the optimal parameter values of the feasible alternatives, respectively.     

Multi-purpose,multi-level feature modeling of large-scale industrial software systems

Feature models are frequently used to capture the knowledge about configurable software systems and product lines. However, feature modeling of large-scale systems is challenging as models are needed for diverse purposes. For instance, feature models can be used to reflect the perspectives of product management, technical solution architecture, or product configuration. Furthermore, models are required at different levels of granularity. Although numerous approaches and tools are available, it remains hard to define the purpose, scope, and granularity of feature models. This paper first reports results and experiences of an exploratory case study on developing feature models for two large-scale industrial automation software systems. We report results on the characteristics and modularity of the feature models, including metrics about model dependencies. Based on the findings from the study, we developed FORCE, a modeling language, and tool environment that extends an existing feature modeling approach to support models for different purposes and at multiple levels, including mappings to the code base. We demonstrate the expressiveness and extensibility of our approach by applying it to the well-known Pick and Place Unit example and an injection molding subsystem of an industrial product line. We further show how our approach supports consistency between different feature models. Our results and experiences show that considering the purpose and level of features is useful for modeling large-scale systems and that modeling dependencies between feature models is essential for developing a system-wide perspective.     

A PDES/STEP-based model and system for concurrent integrated design and assembly planning

Product data exchange and interfacing between different CAD/CAM systems are of great importance to the development of concurrent integrated design environments and computer integrated manufacturing systems. This paper presents a STEP-based method and system for concurrent integrated design and assembly planning. An integrated object model for mechanical systems and assemblies is first defined by a hierarchy of structure, geometry and feature. The structure is represented as a component-connector or joint multi-level graph with both hierarchical functional and assembly relations. These hierarchical relation models are then used for uniformly describing their causal relations both for assembly level and feature based single part level. The generic product assembly model is organized according to STEP, using mostly the entities of integrated resources and partly self-defined entities, which are necessary for design and assembly planning. Based on the generic product assembly model, STEP-based strategies and agent concepts are used for agent-based concurrent integration of design and assembly planning. A prototype system, consisting of a CAD system, a product modeling system, an assembly planning system, and an assembly evaluation system is developed, in which product data can be exchanged between these subsystems. Details about the implementation of the system are addressed. The integrated design and assembly planning system can support the introduction of a new product. The results of assembly planning are feedback to the stage of assembly design to improve on the design. A case study is carried out for assembly-oriented design of a gearbox, to illustrate the proposed approach and to validate the developed system.     

分布式计算环境下的并行设计系统

在并行设计过程中,如何把各个部门的设计信息有效的集成是需要解决的重要问题。该文中的并行设计系统利用面向对象技术描述各个部门建模的特征信息,建立起各个部门的类库。而各个部门的建模系统通过基于CORBA的分布式系统的支持可以方便的获取远端或异构建模系统的特征信息,也可以调用异构建模系统的应用程序,从而实现并行设计。     

以网络为中心的协同特征造型

在网络化同步协同设计环境中,如何实现CAD系统之间的实时数据交换和模型同步,成为协同几何造型的关键问题。文中提出了一种新的复制式协同特征造型方法,该方法将现有的特征造型技术与分布计算、网络通信技术相结合,通过简单的造型消息交换来实现增量式协同造型,可以较好地满足几何模型实时同步的需要,而且也部分地解决了异构CAD软件之间的数据交换问题;并详细地介绍了协同造型通信协议、对象引用机制、以及分布式协同造型系统。     

产品数据管理中的电子图样文件管理平台

产品数据管理(PDM)是目前制造业信息化的核心技术，而电子图样文件管理在PDM系统中起着非常重要的作用。文中在整体功能分析的基础上，提出了一种B／S和C/S结构并存的、高强度安全性的、支持协同设计工作的、面向分步的产品数据信息全生命周期管理的电子图样文件管理平台。并对于平台核心层的实现进行了详细的分析和设计。     

基于结构树的产品制造质量信息建模

为了给面向制造质量的设计提供全面支持,需要对制造质量信息进行有效管理。制造质量信息的组织在其管理中具有重要作用,考虑到结构树作为产品生命周期信息载体的特点,提出了制造质量信息的结构树建模方法。分析了产品构成以及通用信息树的结构,构建了制造质量信息的结构树模型。分析了制造质量信息树的结构、节点、节点及其属性操作,给出了制造质量信息树的构建方法与步骤。以某重型汽车的变速箱为实例,建立了变速箱制造质量信息的结构树模型。     

Product form design using customer perception evaluation by a combined superellipse fitting and ANN approach

Product aesthetics plays an important role in new product design and development. Product form can deliver product images and affect customer’s impression to a product. However, it is usually difficult to apply conventional approaches to represent the product form precisely and effectively for modeling the relationship between product image and customer perception. The objective of this work is to develop a computational technique for product aesthetics design so that customer perception can be taken into product form design in a more systematic and intelligent manner. To achieve this aim, a novel parametric approach is proposed to introduce design parameters such as line, size, and ratio into product design model and the technique of generalized superellipse fitting is adopted to describe the outline pattern of a product. Since customer perception on a product is highly non-linear and very difficult to be described by any traditional mathematical approaches, an artificial neural network (ANN) model is therefore established to relate the design parameters and the perceptual values for the design of a new product. A case study of mobile phone design, in which twelve numerical parameters are defined for the conceptual model, has been conducted to explain the implementation of the proposed approach. A three-layered perceptron ANN model is developed to predict the perceptual values of stylishness based on a survey using 32 mobile phone samples. The results of the case study illustrate that the proposed approach can successfully generate an optimum design of a mobile phone by applying a genetic algorithm (GA) on the trained ANN model.     

不规则文本中商品名称识别的特征选择

传统的命名实体识别任务多见于人名、地名、机构名这些普通的命名实体,且大多采用规则文本进行研究。随着电子商务和互联网广告的不断发展,如何从用户的各种不规则的上下文信息中自动识别出商品名称这一特殊的命名实体成为了一个需要解决的问题。为了解决这一问题,建立了一个最大熵模型用于识别论坛发帖这种不规则文本中的商品名称,并探讨了多种特征对于识别效果的影响。这些特征不仅包括传统命名实体识别方法中所使用的局部特征和布朗聚类特征,还包括词的分布式表示这种比较新颖的特征。这些特征按照各种不同的方式进行组合作为模型的输入。在CPROD01评测数据集上的实验结果表明,布朗聚类特征能够有效地提高商品名称识别系统的准确性。     

Product information visualization and augmentation in collaborative design

In this paper, a collaborative system for product information visualization and augmentation is presented. The developed system allows the users, who can be remotely distributed, to view a product model, which is a geometric representation of the product, from different perspectives. They can choose to view design and product history, such as previous modification processes and feature information of the product independently. The product models displayed to the users are immediately updated after any design modifications have been made to the CAD model. Product features being discussed can be highlighted to draw the users’ attention. In addition, modifications can be displayed dynamically for the users to evaluate the design effect. The product history document module in the system provides a user-friendly interface for retrieving design records. After a specific record has been chosen, the related product model is displayed, and it can be aligned with the current product model for the ease of comparison and evaluation. The feature information of the product is displayed using virtual “floating” annotations linked to the related features. A user interface to enter annotations is provided, and the annotations entered by different users can be shared in real time. A cluster-based greedy algorithm is implemented to avoid overlapping annotations in the field of view.     

Multiple-view feature modelling for integral product development

To allow a designer to focus on the information that is relevant for a particular product development phase, is an important aspect of integral product development. Unlike current modelling systems, multiple-view feature modelling can adequately support this, by providing an own view on a product for each phase. Each view contains a feature model of the product specific for the corresponding phase. An approach to multiple-view feature modelling is presented that supports conceptual design, assembly design, part detail design and part manufacturing planning. It does not only provide views with form features to model single parts, as previous approaches to multiple-view feature modelling did, but also a view with conceptual features, to model the product configuration with functional components and interfaces between these components, and a view with assembly features, to model the connections between components. The general concept of this multiple-view feature modelling approach, the functionality of the four views, and the way the views are kept consistent, are described.     

基于KBE的电梯智能设计系统

开发了一个基于知识工程(KBE)技术的面向客户定制的电梯智能设计系统,通过对电梯产品所蕴涵的知识进行归类建库,实现知识的模块化管理;并综合参数化设计、特征建模和软件集成等技术,将产品的特征和产品中凝聚的知识、经验和规则一体封装,建立内容丰富的实例库,以支持并实现智能设计．使用该系统企业可避免大部分重复开发工作,实现大量既有知识的重用,显著提高企业快速响应市场的能力和新产品开发的效率．     

ASE: A comprehensive pattern-driven security methodology for distributed systems

Incorporating security features is one of the most important and challenging tasks in designing distributed systems. Over the last decade, researchers and practitioners have come to recognize that the incorporation of security features should proceed by means of a structured, systematic approach, combining principles from both software and security engineering. Such systematic approaches, particularly those implying some sort of process aligned with the development life-cycle, are termed security methodologies. There are a number of security methodologies in the literature, of which the most flexible and, according to a recent survey, most satisfactory from an industry-adoption viewpoint are methodologies that encapsulate their security solutions in some fashion, especially via the use of security patterns. While the literature does present several mature pattern-driven security methodologies with either a general or a highly specific system applicability, there are currently no (pattern-driven) security methodologies specifically designed for general distributed systems. Going further, there are also currently no methodologies with mixed specific applicability, e.g. for both general and peer-to-peer distributed systems. In this paper we aim to fill these gaps by presenting a comprehensive pattern-driven security methodology – arrived at by applying a previously devised approach to engineering security methodologies – specifically designed for general distributed systems, which is also capable of taking into account the specifics of peer-to-peer systems as needed. Our methodology takes the principle of encapsulation several steps further, by employing patterns not only for the incorporation of security features (via security solution frames), but also for the modeling of threats, and even as part of its process. We illustrate and evaluate the presented methodology in detail via a realistic example – the development of a distributed system for file sharing and collaborative editing. In both the presentation of the methodology and example our focus is on the early life-cycle phases (analysis and design).     

Traceability and management of dispersed product knowledge during design and manufacturing

Product development processes comprise highly creative and knowledge-intensive tasks that involve extensive information exchange and communication among geographically distributed teams. Due to the geographical and institutional separation between the different systems involved in the product lifecycle, product knowledge sharing is becoming a key issue in the information systems of extended enterprises. This paper addresses the issue and challenges of product knowledge traceability during the product development. The aim of this research effort is to enhance the sharing and use of product knowledge acquired during the development process using traceability information.A standardized approach is proposed to trace and share product knowledge and key constructs to support traceability during the product development process are identified and formalized. This research effort is based on the premise that an important step towards achieving product knowledge sharing is providing traceability across various product knowledge elements that are used in product development phases, i.e. design and manufacturing. Two disjointed but complementary case studies illustrating the benefit of traceability are presented. The potential role of traceability is described, first to support the decision making process during engineering change management (ECM), and second to support product-oriented modelling for knowledge sharing and exchanging to meet the quality requirements. The proposed approach has been implemented using the MEGA Suite tool and applied to each of the case studies and could be integrated to PLM systems currently in use.     

Optimal adaptable design for creating the changeable product based on changeable requirements considering the whole product life-cycle

Compared with the traditional design to create multiple products for satisfying different requirements in different life-cycle time periods, adaptable design aims at creating a single product to satisfy these different requirements through adaptation of this product in its different life-cycle time periods. In this research, a method to identify the optimal adaptable product based on changeable requirements is introduced. The changeable requirements are described as functions of the life-cycle time parameter. The adaptable product, modeled by its configurations and parameters, is changed in different life-cycle time periods to satisfy the changeable requirements. An adaptable product is evaluated considering different time periods in its whole life-cycle. Among all possible design candidates, the optimal design is identified through optimization. A case study is conducted to show the effectiveness of the introduced method.     

A framework for context-aware self-adaptive mobile applications SPL

Mobile Applications are rapidly emerging as a convenient medium for using a variety of services. Over time and with the high penetration of smartphones in society, self-adaptation has become an essential capability required by mobile application users. In an ideal scenario, an application is required to adjust its behavior according to the current context of its use. This raises the challenge in mobile computing towards the design and development of applications that sense and react to contextual changes to provide a value-added user experience. In its general sense, context information can relate to the environment, the user, or the device status. In this paper, we propose a novel framework for building context aware and adaptive mobile applications. Based on feature modeling and Software Product Lines (SPL) concepts, this framework guides the modeling of adaptability at design time and supports context awareness and adaptability at runtime. In the core of the approach, is a feature meta-model that incorporates, in addition to SPL concepts, application feature priorities to drive the adaptability. A tool, based on that feature model, is presented to model the mobile application features and to derive the SPL members. A mobile framework, built on top of OSGI framework to dynamically adapt the application at runtime is also described.     

Induction of multiclass multifeature split decision trees from distributed data

The decision tree-based classification is a popular approach for pattern recognition and data mining. Most decision tree induction methods assume training data being present at one central location. Given the growth in distributed databases at geographically dispersed locations, the methods for decision tree induction in distributed settings are gaining importance. This paper describes one such method that generates compact trees using multifeature splits in place of single feature split decision trees generated by most existing methods for distributed data. Our method is based on Fisher's linear discriminant function, and is capable of dealing with multiple classes in the data. For homogeneously distributed data, the decision trees produced by our method are identical to decision trees generated using Fisher's linear discriminant function with centrally stored data. For heterogeneously distributed data, a certain approximation is involved with a small change in performance with respect to the tree generated with centrally stored data. Experimental results for several well-known datasets are presented and compared with decision trees generated using Fisher's linear discriminant function with centrally stored data.