The emergence of the system configurator

As companies move from custom built software to commercial packages, the skills and mindsets required to make applications work have changed. In their emerging role, system configurators reverse the traditional process steps of high-level project management. For example, with a commercial software package, these steps often start with installation, rather than end with it. In this environment, system configurators must have both a strong knowledge of the software package and a keen understanding of the business needs. Having strong players in this pivotal role can mean the difference between successful and unsuccessful system deployments.     

2DCMA: An Effective Maintenance Algorithm of Materialized Views in Peer Data Management Systems

Update management is very important for data integration systems. So update management in peer data management systems （PDMSs） is a hot research area. This paper researches on view maintenance in PDMSs. First, the definition of view is extended and the peer view, local view and global view are proposed according to the requirements of applications. There are two main factors to influence materialized views in PDMSs. One is that schema mappings between peers are changed, and the other is that peers update their data. Based on the requirements, this paper proposes an algorithm called 2DCMA, which includes two sub-algorithms： data and definition consistency maintenance algorithm% to effectively maintain views. For data consistency maintenance, Mork＇s rules are extended for governing the use of updategrams and boosters. The new rule system can be used to optimize the execution plan. And are extended for the data consistency maintenance algorithm is based on the new rule system. Furthermore, an ECA rule is adopted for definition consistency maintenance. Finally, extensive simulation experiments are conducted in SPDMS. The simulation results show that the 2DCMA algorithm has better performance than that of Mork＇s when maintaining data consistency. And the 2DCMA algorithm has better performance than that of centralized view maintenance algorithm when maintaining definition consistency.     

Determination of scale elasticity in the existence of non-discretionary factors in performance analysis

Discretionary models of data envelopment analysis (DEA) assume that all inputs and outputs can be varied at the discretion of management or other users. In any realistic situation, however, there may exist “exogenously fixed” or non-discretionary factors that are beyond the control of a DMU’s management, which also need to be considered. In this paper, Banker’s definition of scale elasticity and returns to scale is modified so that it includes the non-discretionary factors, as well. Then, an efficient algorithm which is capable of determining scale elasticity in the existence of non-discretionary factors is provided.     

Product performance as a unifying theme in concurrent design—II. Software

Engineering design involves the satisfaction of customer needs, These needs, whether explicitly stated or only implicitly defined, must be translated into a set of specifications for a product. The subsequent stages of design, fabrication, and maintenance are dedicated to the fulfillment of these specifications. The task of concurrent design is to ensure that the product performs as specified, with fidelity and consistency. Ensuring product performance is the objective of quality assurance. Software packages can be developed to assist in this effort, ranging from the initial phase of requirements definition to production control and maintenance.     

IPSec和IP Filter在路由器中部署策略的研究

IPSec和IP Filter是IPv6路由器中的重要安全部件．IPSec的安全关联查找引擎具有类似于IP Filter的功能,也需要对IP包进行过滤和匹配,路由器中流动的IP包可能需要经过这两个部件的重复过滤,因此,这两个部件之间的部署策略将会直接影响到IP包的处理效率．从路由器整体安全的角度分析了两个安全部件之间的相互关系,提出了一个新的部署策略．与国际上著名的开放源码IPv6协议栈KAME相比较,该部署策略可以提高IPSec的处理效率,减轻IP Filter对IPSec的负面影响,同时,也减少了IP包在路由器中的重复过滤,提高了IP包的处理效率．     

Selecting and Implementing Project Management Software

As the importance of project management software increases in industry, commerce, and government, so does the choice of project management software packages. However, many organizations select such packages according to how many features they advertise rather than how well they serve their organization's business function. This article presents a model for selecting and implementing a project management software package.     

Paradigm shift: unified and associative feature-based concurrent and collaborative engineering

With widely used concurrent and collaborative engineering technologies, the validity and consistency of product information become important. In order to establish the state of the art, this paper reviews emerging concurrent and collaborative engineering approaches and emphasizes on the integration of different application systems across product life cycle management (PLM) stages. It is revealed that checking product information validity is difficult for the current computer-aided systems because engineering intent is at best partially represented in product models. It is also not easy to maintain the consistency among related product models because information associations are not established. The purpose of this review is to identify and analyze research issues with respect to information integration and sharing for future concurrent and collaborative engineering. A new paradigm of research from the angle of feature unification and association for product modeling and manufacturing is subsequently proposed.     

Package Coupling Measurement in Object-Oriented Software

The grouping of correlated classes into a package helps in better organization of modern object-oriented software. The quality of such packages needs to be measured so as to estimate their utilization. In this paper, new package coupling metrics are proposed, which also take into consideration the hierarchical structure of packages and direction of connections among package elements. The proposed measures have been validated theoretically as well as empirically using 18 packages taken from two open source software systems. The results obtained from this study show strong correlation between package coupling and understandability of the package which suggests that proposed metrics could be further used to represent other external software quality factors.     

Digital twin-based assembly data management and process traceability for complex products

Complex products such as satellites, missiles, and aircraft typically have demanding requirements for dynamic data management and process traceability. The assembly process for these complex products involves high complexity, strong dynamics, many uncertainties, and frequent rework and repair, especially in the model development stage. Achieving assembly data management and process traceability for complex products has always been a challenge. A recently proposed solution involves one-to-one mapping of the corresponding physical entity, also known as the digital twin method. This paper proposes a digital twin-based assembly data management and process traceability approach for complex products. First, the dynamic evolutionary process of complex product assembly data was analyzed from three dimensions: granularity, period and version. Then, a framework of digital twin-based assembly data management and process traceability for complex products was constructed. Some core techniques are: 1) workflow-based product assembly data organization and version management; 2) synchronous modeling of the product assembly process based on digital twin; and 3) hierarchical management and traceability of product assembly data based on digital twin. On this basis, an algorithm flowchart for generating a product assembly data package was created, which includes product assembly data management, assembly process traceability, and generation of a product assembly data package. Furthermore, the Digital Twin-based Assembly Process Management and Control System (DT-APMCS) was designed to verify the efficiency of the proposed approach. Some aerospace-related assembly enterprises are currently using DT-APMCS and achieving satisfactory results. Finally, a summary of our work is given, and the future research work is also discussed.     

一种基于Internet的JAR包使用信息收集方法

随着软件复用技术的发展,Internet上出现了大量可以被利用的软件资源,如Web Services, JAR包等。但是,这些软件资源常常缺乏必要的描述信息和使用说明。为此,提出了一种基于Internet的JAR包使用信息收集方法,以帮助用户检索并整理Internet上已经存在的JAR包描述信息和用户使用评论,辅助软件复用的成功进行。基于该方法,设计并实现了北京大学软件资源库JAR包使用信息收集子系统。该系统目前已经为6000余个JAR包资源收集、整理了相关的描述和评论信息。     

Package downsizing: is it ethical?

Package downsizing is a practice where the package content is reduced without changing the package or the price of the product. In a market that is defined by ‘hyper-competition,’ package downsizing is often practiced by marketers to effect an invisible price increase for their products. Although marketers may maintain that providing, the legally required, quantity indication on the package is adequate for customers to make logical and informed choices, research indicates that consumers often do not consult quantity indications on packages but use alternative methods (e.g., visual impressions of the package size, total package price, or previous purchase experience) to judge product quantity and to calculate product value. As a subtle means, package downsizing therefore has the potential to mislead customers in the buying process due to an unfavorable balance of information within the dyad. This could give rise to serious moral and ethical consideration. In this paper, we examined various issues related to package downsizing, such as why sellers resort to this type of practice, consumer vulnerability to package downsizing, as well as the extent of protection offered to consumers by the existing laws and regulations with respect to product packaging. Finally, we examined the ethics of package downsizing using the existing legal, moral, and professional ethical standards as well as the principle of equivalence. Our analysis indicates that package downsizing, as it is practiced by the marketers and sellers today, is unethical as far as the consumers are concerned.     

基于CATIA的加油车数字样机建模及应用研究

应用数字样机取代物理样机可有效解决传统装备设计依靠物理样机、需要反复试制物理样机,以致设计周期长、成本高的问题。以加油车的研制为例,对装备数字样机建立的一般方法和基本流程进行研究,应用CATIA建立了加油车数字样机模型,进行了相关检测,验证了基于CATIA创建的数字样机代替物理样机解决和交流设计过程中的问题的可行性,使高质、高效、低成本的装备设计和制造成为可能。     

The application of microcomputer data-base management packages in medical research

The role of microcomputer data-base management (DBMS) packages in the management of medical research studies has been reviewed. The features of commercial DBMS packages which are of particular advantage have been identified.A bench-mark test, resembling stages in the conduct of a research project, was constructed and four commercial packages compared in their performance of it. The packages varied in facilities offered, and it was found that the more sophisticated ones took longer to set up to perform the task. In use the less sophisticated packages were faster, but could become tedious to use with regular tasks and more error prone with complex tasks.The selection of a DBMS package depends on the potential application. This will involve a detailed assessment of the task to be performed: as a general rule a sophisticated package will only be warranted if the study is both complex and large. In practice research departments may benefit from more than one package.     

多数据库系统中的一致性维护

在多数据库环境中存在着全局事务和局部事务,它们必须相互协作,从而为应用程序提供一致性的数据。为了维护多数据库系统（MDBS）的一致性,提出一种事务管理机制。该机制基于扩展事务的原理,对全局子事务和局部事务进行扩展,并为各个局部数据库引进一些控制表。局部数据库管理系统（LDBMS）和局部数据库和控制表之上执行扩展务,这些扩展事务负一局可串行性及事务的恢复。由于它不依赖于LDBMS的各种特征,因此该方法易于实现,是实用的。     

The Package Blueprint: Visually analyzing and quantifying packages dependencies

Large object-oriented applications are structured over many packages. Packages are important but complex structural entities that are difficult to understand since they act as containers of classes, which can have many dependencies with other classes spread over multiple packages. However to be able to take decisions (e.g. refactoring and/or assessment decisions), maintainers face the challenges of managing (sorting, grouping) the massive amount of dependencies between classes spread over multiple packages. To help maintainers, there is a need for at the same time understanding, and quantifying, dependencies between classes as well as understanding how packages as containers of such classes depend on each other.In this paper, we present a visualization, named Package Blueprint, that reveals in detail package internal structure, as well as the dependencies between an observed package and its neighbors, at both package and class levels. Package blueprint aims at assisting maintainers in understanding package structure and dependencies, in particular when they focus on few packages and want to take refactoring decisions and/or to assess the structure of those packages. A package blueprint is a space filling matrix-based visualization, using two placement strategies that are enclosure and adjacency. Package blueprint is structured around the notion of surfaces that group classes and their dependencies by their packages (i.e., enclosure placement); whilst surfaces are placed next to their parent node which is the package under-analysis (i.e., adjacency placement). We present two views: one stressing how an observed package depends upon the rest of the system and another stressing how the system depends upon that package.To evaluate the contribution of package blueprint for understanding packages we performed an exploratory user study comparing package blueprint with an advanced IDE. The results show that users of package blueprint are faster in analyzing and assessing package structure. The results are proved statically significant and they show that package blueprint considerably improves the experience of standard browser users.     

Globally consistent reconstruction of ripped-up documents

One of the most crucial steps for automatically reconstructing ripped-up documents is to find a globally consistent solution from the ambiguous candidate matches. However, little work has been done so far to solve this problem in a general computational framework without using application-specific features. In this paper, we propose a global approach for reconstructing ripped-up documents by first finding candidate matches from document fragments using curve matching and then disambiguating these candidates through a relaxation process to reconstruct the original document. The candidate disambiguation problem is formulated in a relaxation scheme, in which the definition of compatibility between neighboring matches is proposed and global consistency is defined as the global criterion. Initially, global match confidences are assigned to each of the candidate matches. After that, the overall local relationships among neighboring matches are evaluated by computing their global consistency. Then these confidences are iteratively updated using the gradient projection method to maximize the criterion. This leads to a globally consistent solution and thus provides a sound document reconstruction. The overall performance of our approach in several practical experiments is illustrated. The results indicate that the reconstruction of ripped-up documents up to fifty pieces is possibly accomplished automatically.     

Scoping the global market: size is just part of the story

The IT market is changing so quickly that it's hard to keep pace. This concern is what motivated a recent study conducted by the International Data Corp. (IDC) and published by the World Information and Technology and Services Alliance. WITSA-a consortium of 35 IT trade associations worldwide-wanted more than market estimates. Its members wanted hard data on size and impact of the IT industry-details like the number of computers being used, the total IT investment companies made both inside and outside their walls, and the effect of that investment on individual countries worldwide. The resulting publication, Digital Planet-The Global Information Economy, provides measurements from 1992 to 1997 for the global IT industry with details for the 50 largest countries. Collectively, they represent 98 percent of the world's spending on IT and 97 percent of the world's gross domestic product (GDP). The Digital Planet study is unique in several respects. It is the first to look at IT's influence from a global perspective, to measure internal spending on IT, and to examine IT's social and economic effects. It is also the first to use hard data and consistent definitions on such a large scale     

Computer aided engineering of automated guided vehicle systems

Automated Guided Vehicle Systems (AGVS) are becoming more and more the main material handling devices in flexible manufacturing systems. The design of an AGVS network is a complex, iterative process. It requires a sequence of geometrical layout drawings and an analytical and computational evaluations. The ability to analyze the AGVS design directly and interactively from the layout drawing would substantially increase the productivity of the design engineer.

A Computer Aided Engineering (CAE) design tool must provide the following three capabilities. First, it must allow the easy, interactive and graphical definition of the system by providing standard drawing symbols and the required operations on those symbols. Second, it must support direct, interactive analysis of the design from within the drafting package. Third, it must provide for the necessary output to interface with off line simulation, analysis and verification programs.

The possibility of extending the prominent CAD packages CADAM and AutoCad to perform CAE of AGVS is examined. A prototype of such a CAE tool has been developed based upon the Autocad package and implemented on a microcomputer. Design and implementation issues, as well as future research areas, will be reported on.     

Dynamic data sharing and security in a collaborative product definition management system

Product definition management (PDM) is a system that supports management of both engineering data and the product development process during the total product life cycle. The formation of a virtual enterprise is becoming a growing trend, and vendors of PDM systems have recently developed a new generation of PDM systems called collaborative product definition management (cPDM). This paper presents the concept of a virtual engineering community (VEC) to support concurrent product development within geographically distributed partners. A previous case study has shown that collaborative engineering design may be modelled from a parameter perspective [1]. Effective implementation of the parameter approach raises the following problems: how to support data sharing and secure that span the partner borders. This paper describes the system architecture, deployed security mechanisms, the prototype developed within cPDM, and the system demonstration using a real test. The implementation of this architecture extends a common commercial PDM system (Axalan™) and utilizes standard software to create a security framework for the involved resources. Collaboration infrastructure, shared team spaces and shared resources are essential to enable virtual teams to work together. Various organizational and technical challenges are implied. The outlined architecture features a federated data approach. These issues are discussed and potential perspectives in the area of collaboration engineering are identified.     

Hierarchical structures of optimization packages

Conclusions The expanding operational potential of application packages (interactive and multiprocessing disciplines, application in systems with complex environment, processing of large volumes of data) necessitated a transition from the one-level to a hierarchical package model, in line with the increasing complexity of the package structure.Not all the levels are necessarily present in the design of specific packages. For example, packages executing in the batch mode without multiprocessing and user-initiated dialog do not need the process synchronization level, whereas the top level-the process level-is realized by a single process (in the operating system sense) with the structure described in [1–3]. Packages whose programs always fit into the main memory do not need the data management level, i.e., the cluster is realized by an abstract application module. The application program level is missing in those packages where the application programs are prepared in advance, rather than being generated in run time.The proposed structure is not restricted to optimization packages: it may be used to typify other classes of method-oriented packages. Structure-driven package design ensures that the package has the required properties, makes it possible to implement the software-engineering approach to the design process, avoids gross design errors, and simplifies package adaptation to different environments. Moreover, the hierarchical package structure allows a more technological approach to the development process, as it leads to more effective application of the methods of hierarchical, modular, and structured programming.Translated from Kibernetika, No. 2, pp. 35–39, March–April, 1982.