位置互连Petri网的分散与协调控制

本文引入位置互连Petri网,对能用位置互连Petri网描述的离散事件系统提出了一种分散与协调控制框架,在这个框架下,我们讨论了一类常见的禁止状态控制问题,给出了综合其量小约束协调控制的一种有效算法。     

Verbal satiation and the role of concurrent activity.

2 studies, including 16 Ss in each, were performed to investigate the effect of concurrent activity on the maintenance of word meanings (verbal satiation). It was found, in both studies, that words repeated with activity maintained their meanings significantly longer than words repeated without activity. Word meaning maintenance was also found to relate to the kind of concurrent activity: words were more facilitated by actions customarily paired with them (e.g., push with pushing activity) than by actions not customarily paired with them. In addition, results indicated that a word could be maintained longer when the concurrent activity included (Experiment II) the added sensory input of vision. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approaching lean product development using system dynamics:investigating front-load effects

Competing with successful products has become perplexing with several uncertainties and transmutes from time to time as customers’ expectations are
dynamic. That is why manufacturing firms exhaustively strive to look for a better competitive frontier using wellestablished and innovative product development (PD) processes. In this paper, we would like to answer three research questions: (i) What would be the effects of frontloading
in PD? (ii) Can we improve our PD process endlessly? (iii) When is the critical time that the firm should take remedial action for improvements? As a contribution to the vast numbers of improvement methods in new product development (NPD), this paper investigates the effects of front-loading using set-based concurrent engineering (SBCE) on cost and lead time. Models are developed and treated using a system dynamics (SD) approach. We assign a hypothetical upfront investment for SBCE and compare its effects on  total cost and lead time of the development process. From the research, it is found that the total cost of PD is reduced almost by half-although the front loading is higher in order to encompass multiple design alternatives. The total product lead time is reduced by almost 20 %. The model reveals the critical time for improvement of the PD process. We use SD tool (e.g., STELLA) for simulation and visualization of the complex PD model, using SBCE as one of several strategies to frontload activities in the NPD process.     

基于同时生效签名的PayWord协议公平性改进

PayWord协议出于对效率和成本的考虑,对于支付公平性方面缺乏支持。基于PayWord协议提出了一个新型的公平支付方案,通过在PayWord协议中引入同时生效签名对消费者的支付承诺提供保护,并且设计了模糊商品服务承诺对商家提供保护,从而提高了PayWord协议的公平性。由于方案避免使用公开密钥算法,因而在保证支付的公平性的基础上还兼顾了支付效率。     

并行工程在企业产品开发过程中的应用

沈阳机床股份有限公司与美国ＥＤＳ公司共同合作对产品开发过程进行了管理咨询，经评诂、展望、设计、试点和铺开等阶段弛产品开发过程。根据在企业试点、铺开过程中取得的经验，并结合我国机械制造业的产品开发现状，对产品开发过程中应用并行工程主要方法和将要出现的问题及解决办法进行描述和分析。     

双向数字电视网络建设与IPQAM的布局

数字电视整转后，采用IPQAM进行双向互动的规划和建设时，需要了解IPQAM的基本原理以及并发流与IPQAM的覆盖用户数计算，在双向数字电视网络合理布局IPQAM。     

Triggered Concurrent Batch Arrivals and Batch Departures in Queueing Networks

We consider a queueing network with concurrent batch arrivals and batch services. In addition to the batch movement assumptions made in the regular queueing literature, in this paper we assume that the batch movement can also be triggered by arrivals and/or departures. Specifically, an arriving or departing batch may induce another event to occur before they are routed. This triggered event may either be the addition of a batch of customers to the network, or the removal of a batch of customers from the network. This special feature makes it useful in the study of discrete event dynamic systems with concurrent or simultaneous sequential activities. By assuming that there is an additional arrival process to the network, we show that its stationary distribution has a product form, which depends on a set of non-standard nonlinear traffic equations. Furthermore, this simple product form solution is a stochastic upper bound for the network without the additionally introduced arrivals. Besides, we show that the network satisfies a class of non-standard local balance equations.     

A multichannel relay MAC protocol for IEEE 802.11 wireless LANs

One of the challenging issues in wireless LANs (WLANs) is improving the network throughput. One of the possible solutions for the issue is maximizing the number of concurrent transmissions. Although some protocols have been proposed to exploit transmission concurrency in WLANs, their performance depends on the degree of the interference among links. Also, it is hard to obtain interference information because of their dynamics. In this paper, we propose an enhanced medium access control (MAC) protocol for WLANs, named multichannel relay MAC (MRMAC), which is able to transmit multiple frames simultaneously without considering interference. To enable concurrent transmissions, MRMAC adopts the concept of frame relaying. Furthermore, MRMAC utilizes several nonoverlapping channels to eliminate interferences. Through extensive simulations, we found that MRMAC shows better performance than existing well‐known MAC protocols. Copyright © 2013 John Wiley & Sons, Ltd.     

基于变迁系统的反应型控制系统建模与分析

文中通过对基本变迁系统进行相应的扩充，分别给并发、实时及混成等3个不同轴象层次反应型控制系统的计算模型，并分析它们各自不同的特点。     

MetaMorph II: an agent-based architecture for distributed intelligent design and manufacturing

Agent technology derived from Distributed Artificial Intelligence is increasingly being considered for next generation computer-integrated manufacturing systems, to satisfy new requirements for increased integrability, configurability, adaptability, extendibility, agility, and reliability. This paper reviews our previous research on the application of the agent-based technology to intelligent design and manufacturing and describes the current research project MetaMorph II (an agent-based architecture for distributed intelligent design and manufacturing).