Multiproject strategy, design transfer, and project performance: asurvey of automobile development projects in the US and Japan

Large manufacturers usually need to manage multiple projects in order to leverage their financial and engineering resource investments on new technologies and designs. The purpose of this paper is to explore the relationship between different multiproject strategies and project performance measured by lead time and engineering hours. The multiproject strategy in this study focuses on different ways of transferring core technologies and designs from one project to another within the firm. First, this paper proposes a typology of different multiproject strategies, which categorizes new product development projects into four types: new design, rapid design transfer, sequential design transfer, and design modification. Second, using survey results on 103 different new product projects at 10 automobile firms in Japan and the US, this study concludes that projects using the rapid design transfer strategy are the most efficient in terms of engineering hours. Only through rapid design transfer can a preceding design be transferred from a base project to a new project with effective task sharing among engineers and mutual adjustments between the two projects. This paper also discusses organizational requirements for managing rapid design transfer projects. Neither a pure project-team approach nor a functional approach seem appropriate for the management of concurrent multiple projects     

Managing multiple engineering projects in a manufacturing supportenvironment

Business trends require front-line managers to integrate multiproject concepts with those of traditional single-project management since very rarely can one find major organizations managing just one project. A typical situation entails a limited pool of resources which is applied to the management of several projects, with people moving back and forth among different assignments in different projects. Yet, few studies on project management have started to explore the issue of how to manage an organization with multiple inter- or intradepartmental projects. Using a case study method, our exploratory research investigates the specific problems associated with the management of multiple engineering projects in a manufacturing support environment, with the intent to identify common factors of success. Knowing the factors of success is but the first step toward improving multi-project management. Our findings provide insight into how the most important multiple-project success factors in this environment differ from factors of success in traditional single-project management, and are consistent with other emerging research in product development environments. The differences center on resource allocation and flexibility. Some factors, such as ownership, staff experience, and communication, take on additional dimensions when considered in a multiple-versus a single-project environment. Division and assignment of resources, prioritization, and customized management style, which have little relevance in relation to single projects, are shown to play a major role in the success of multiproject management     

电子产品可靠性评价与物理模型应用探讨

该文以电子产品的故障为出发点,从集成电路-封装、集成电路-芯片、电路板(或线路板)、电子元件、系统和多系统的角度论述了不同任务环境下电子器件的故障机理特点。系统论述了故障模式、影响及危害性分析(FMECA)和故障模式、机理与影响分析(FMMEA)两种故障机理分析方法,同时结合低周疲劳、高周疲劳、裂纹萌生、反应论模型、芯片失效等失效机理对故障物理元模型进行分类讨论,对电子产品可靠性评价与物理模型应用进行了系统的探讨,为电子产品可靠性评价及失效物理评估模型的选取提供了依据。     

DFC++ Processing Framework Concept

Development of modern Software Defined Radio (SDR) based communication systems can be accelerated significantly by the use of processing frameworks. The evolution of SDR and the involved departure from digital representations of classical radio architecture towards more abstract software systems raises new requirements of increased flexibility and versatility. The proposed Data Flow Control for C++ (DFC++) processing framework concept addresses those requirements by employing modern programming techniques and flow control mechanisms to allow for variable data rates, dynamic paths, and flexible component designs. Another important trend is the integration of various embedded platforms in the software radio domain. The rapidly increasing performance and efficiency of embedded processors enables the deployment of SDR systems in more space and power constrained environments. Therefore covering a heterogeneous hardware selection becomes increasingly important for processing frameworks. By relying exclusively on C++ and minimizing external dependencies, DFC++ is specifically aiming for excellent portability and adaptability to support a wide range of current and future software radio projects while maintaining high performance and ease of use. This paper introduces the key aspects of the DFC++ concept and implementation with focus on the reference pointer based data transport mechanisms responsible for the propagation of user data between different processing components.     

Planning agents in JAMES

Testing is an obligatory step in developing multiagent systems. For testing multiagent systems in virtual, dynamic environments, simulation systems are required that support a modular, declarative construction of experimental frames, that facilitate the embedding of a variety of agent architectures and that allow an efficient parallel, distributed execution. We introduce the system JAMES (a Java based agent modeling environment for simulation). In JAMES, agents and their dynamic environment are modeled as reflective, time-triggered state automata. Its possibilities to compose experimental frames based on predefined components, to express temporal interdependencies, to capture the phenomenon of proactiveness and reflectivity of agents are illuminated by experiments with planning agents. The underlying planning system is a general-purpose system, about which no empirical results exist besides traditional static benchmark tests. We analyze the interplay between heuristics for selecting goals, viewing range, commitment strategies, explorativeness, and trust in the persistence of the world and uncover properties of the the agent, the planning engine, and the chosen test scenario: TILEWORLD     

虚拟机监控器的安全威胁及规避措施

云计算通过使用虚拟化技术,将大规模数据中心的设备分成独立的小型资源按需租用给用户。这种多租户环境建立的前提是虚拟化平台是安全可靠的,以确保位于同一台物理主机上的不同用户之间的独立性不被破坏。然而现有虚拟机控制器都拥有一个规模较大的可信计算基,使得其管理的虚拟机存在较大安全风险。文中提出一种方法,将传统的控制虚拟机分解为各个组件组成,每个组件执行单一的功能。这样可以带来一些好处：客户共享的服务组件是可配置和可审计的;限制每个组件以所需的最小权限接入Hypervisor,这使得风险明确化;通过配置组件的微重置的频率,可减小单个组件的时间攻击面。     

Middleware for Protocol-Based Coordination in Mobile Applications

In distributed mobile applications, component interaction is complicated by dynamics in the environment. ObjectPlaces middleware supports the development of interaction protocols in dynamic, mobile environments to facilitate component coordination.     

军用电子元器件的新发展

电子元器件在未来商业和军事运用中都将起到十分重要的作用。文中介绍了对未来武器装备发展影响较大的几项军用电子元器件科技发展情况,提出新概念理论是未来设计发展方向,介绍了集成电路以及碳化硅、高温超导、光纤等新材料在军事上的发展前景。     

Taming heterogeneity - the Ptolemy approach

Modern embedded computing systems tend to be heterogeneous in the sense of being composed of subsystems with very different characteristics, which communicate and interact in a variety of ways-synchronous or asynchronous, buffered or unbuffered, etc. Obviously, when designing such systems, a modeling language needs to reflect this heterogeneity. Today's modeling environments usually offer a variant of what we call amorphous heterogeneity to address this problem. This paper argues that modeling systems in this manner leads to unexpected and hard-to-analyze interactions between the communication mechanisms and proposes a more structured approach to heterogeneity, called hierarchical heterogeneity, to solve this problem. It proposes a model structure and semantic framework that support this form of heterogeneity, and discusses the issues arising from heterogeneous component interaction and the desire for component reuse. It introduces the notion of domain polymorphism as a way to address these issues.     

Role-based collaboration and its kernel mechanisms

Computer-supported cooperative work (CSCW) systems are computer-based tools that support the collaborative activities of human users. They should not only support virtual face-to-face collaborative environments but also improve face-to-face collaboration by providing more mechanisms to overcome the drawbacks of usual face-to-face collaboration. Introducing roles into CSCW systems is important in achieving this. This paper's contributions include establishing the requirements for a role-based collaboration, presenting the concept, requirements, and principles of role-based collaboration, proposing a model E-CARGO for role-based collaboration, and describing the kernel mechanisms and their implementation to facilitate the development of role-based collaborative systems for industrial applications.     

Design and analysis of a low-noise saw-less receiver front-end resistant to strong out-of-band blocker

Regulatory changes to spectrum management frameworks in the U.S. and worldwide are promoting the use of dynamic spectrum access (DSA) and spectrum sharing mechanisms. Wireless service environments that use these mechanisms will rely heavily on radio interference control and management techniques to coordinate the boundaries of spectrum use for devices owned/managed by different entities. To communicate the characteristics and limits of spectrum use of an RF transmitter, receiver, system or collection of systems, a common data structure to represent this information must be in place. Spectrum consumption models (SCMs) attempt to capture this information and support a set of computations that allow for the determination of the compatibility of the use of spectrum between devices and/or systems that communicate the characteristics of their use of spectrum with these models. SCMs are currently being standardized within the IEEE DySPAN-SC 1900.5.2 workgroup. This paper presents our results and ongoing efforts in developing an open source tool for the construction and analysis of SCMs as a means to promote their use and showcase their potential for enhancing spectrum sharing and DSA interactions.     

Improving product launch times and product design through a service assembly environment

Surely it must be possible to bring products to market faster and do it cheaper? These two requirements have for many years challenged the entire telecommunications industry. Complexity is a characteristic of today’s communications environments. Making this complexity manageable is the key to enabling these requirements to be met, but how? Within the intelligent network’s area it has been possible to break down the needs of the customer into a series of blocks that can be designed and deployed in flexible arrangements. To design and run these blocks two environments are used, the service assembly environment (SAE) and the service execution environment. This paper will look at the former to examine what steps need to be taken to apply these principles to the full range of communications products that a large telecommunications company like BT offer. This paper defines the SAE as including both the design phase of a product as well as its deployment into the portfolio and systems.     

Factors influencing success in integrated product development (IPD)projects

Given the fact that there are thousands of components involved in the development process of an automobile or other similar complex products, coupled with many groups of people with different backgrounds, it is important to explore factors that can help the integration of the different groups and the tasks leading to project success. The authors conducted five in-depth case studies in one European automobile company and three first-tier suppliers also based in Europe. They focus not only on internal management, but also on the external management of integrated development projects (IPDs). Their data showed that there are five key areas-brand or vision deployment, understanding of customer needs or specifications, supplier involvement in the development process, project management and purchasing-that can contribute to the success of integrated development projects. They identify a number of critical issues in the aforementioned key areas that could help to improve the management and, thus, enhance the success potential of IPD projects. This paper explores the issues relating to success in IPD projects in companies that outsource the component/systems development     

Multiproject staff scheduling with variable resource constraints

An analytical approach and a PC software based solution are presented to a project management problem, in which multiple resources must be allocated to perform both routine tasks and a set of projects with varying levels of priority. The performance of a priority-based decision rule was tested on this project management problem. The model was able to provide division-level management with an effective tool for staff workload planning and program management. A sequential, iterative approach is developed and used to test and evaluate alternative PC commercial software on a set of projects and evolving criteria. A PC commercial software package, with associated heuristics, is demonstrated to provide useful results to multiproject staff scheduling problems in an actual organization     

Capacity limits of spectrum‐sharing systems over hyper‐fading channels

Cognitive radio (CR) with spectrum‐sharing feature is a promising technique to address the spectrum under‐utilization problem in dynamically changing environments. In this paper, the achievable capacity gain of spectrum‐sharing systems over dynamic fading environments is studied. To perform a general analysis, a theoretical fading model called hyper‐fading model that is suitable to the dynamic nature of CR channel is proposed. Closed‐form expressions of probability density function (PDF) and cumulative density function (CDF) of the signal‐to‐noise ratio (SNR) for secondary users (SUs) in spectrum‐sharing systems are derived. In addition, the capacity gains achievable with spectrum‐sharing systems in high and low power regions are obtained. The effects of different fading figures, average fading powers, interference temperatures, peak powers of secondary transmitters, and numbers of SUs on the achievable capacity are investigated. The analytical and simulation results show that the fading figure of the channel between SUs and primary base‐station (PBS), which describes the diversity of the channel, does not contribute significantly to the system performance gain. Copyright © 2011 John Wiley & Sons, Ltd.     

Adaptive robust impulse noise filtering

It is well known that when data is contaminated by non-Gaussian noise, conventional linear systems may perform poorly. The paper presents an adaptive robust filter (adaptive preprocessor) for canceling impulsive components when the nominal process (or background noise) is a correlated, possibly nonstationary, Gaussian process. The proposed preprocessor does not require iterative and/or batch processing or prior knowledge about the nominal Gaussian process; consequently, it can be implemented in real time and adapt to changes in the environment. Based on simulation results, the proposed adaptive preprocessor shows superior performances over presently available techniques for cleaning impulse noise. Using the proposed adaptive preprocessor to clean the impulsive components in received data samples, conventional linear systems based on the Gaussian assumption can work in an impulsive environment with little if any modification. The technique is applicable to a wide range of problems, such as detection, power spectral estimation, and jamming or clutter suppression in impulsive environments     

多构件库统一刻面检索机制

不同构件库之间实现互通可以有效提高复用者获取构件的效率.现有相关工作如UDM/BIDM、DCH、U-ranus、UDDI等存在对多构件库检索技术研究的不足.分类是检索的基础,刻面分类是构件库常用分类方法之一,本文在刻面分类的基础上研究了多构件库检索的基本原理,并由此提出一种统一的刻面检索机制,为不同构件库之间互通的实现奠定了基础.     

Multimedia and hip-hop for experiential education

This paper describes recent work on two student-centered learning environment projects that take experiential approaches to education through the creative and exploratory use of digital media in structured learning environments. The paper examines the use of media creation tools, the development of hybrid physical/digital learning environments, innovative curriculum design, and hybrid strategies for assessment. The research methods employed focus on the role of digital media in facilitating human-to-human interaction between teachers and groups of students while utilizing a variety of instructional methods     

移动自组织网络下一种基于可用性感知的服务选择方法

Service composition is considered to be an effective way for resource sharing and node collaboration in Mobile Ad hoc NETworks (MANETs) environment. In order to improve the reliability and shorten the response time of composite services, this paper first analyzes the node environments and network environments that affect the component services’ availability, and then proposes an Environment-aware Quantitative Evaluation Model for Service Availability (EQEM-SA). In addition, based on EQEM-SA, a service field concept is proposed as well as the availability attenuation equation, where the availability value is considered as the field strength. Then the service selection approach based on service field model is presented. The effectiveness of the proposed approach is illustrated and compared with related references, and the results of experimental evaluations indicate that our approach significantly reduces the failure rate and shortens the service delay.     

Some reliability measures of a system of components sharing a common environment

A multivariate distribution for describing the lifespan of the components of a system which operates in an environment whose intensity is in constant overtime but different from that of the test bench (laboratory) environment. The properties of the reliability function of a system of components sharing a common environment are studied in this paper. Comparison would also give a sense of the robustness of independent assumptions in system reliability calculations. It is to be noted that the reliability function of parallel redundant systems whose components share a common unknown environment cannot be characterized by any of the well-known classes of distribution studied in the mathematical theory of reliability. The above conclusions suggest the need for defining and studying the properties of a new class of failure distribution in reliability theory. We have derived the mean time before failure, maintainability M(t), and mean time to failure of the system.