A QFD-based method to support SMEs in benchmarking co-design tools

Efficient collaborative product design is crucial for extended enterprises willing to develop complex products pursuing a short time to market. However, successful collaborative product design depends on the ability to effectively manage and share engineering knowledge and data throughout the entire product development process. Co-design software platforms aim to facilitate cooperation in distributed teams. In the context of Small and Medium Enterprises (SMEs) the advanced co-design software implementation to support the supply chain is not a trivial task. SMEs have peculiar characteristics such as flexibility, ICT skills and financial resources, which are difficult to be integrated within a structured design network. This paper presents a method to define and evaluate a co-design platform dedicated to SMEs in the mechanical product field. System architecture is defined by applying suitable metrics based on collaborative process characteristics in order to assess functionality performance of the available tools. Benchmarking is based on different levels of collaboration recognized in the typical product development process in SMEs. Correlation between process metrics, software functionalities and specific collaboration requirements is managed by adopting Quality Function Deployment (QFD) techniques. A practical case study allows the robustness of the proposed method to be verified and the main advantages and future developments to be discussed.     

搜索引擎流量模型分析与测试

介绍搜索引擎的查询服务工作原理．通过网络拓扑分析、路由分析等方法,研究查询服务对网络流量的影响．由此搭建网络流量估算模型,做到对网络性能瓶颈的准确预测,在对该模型进行有针对性的测试后．提出可以更有效地解决网络性能方面问题的搜索引擎数据中心网络部署方案．保证网络设备能满足搜索引擎性能需求。     

无线传感器网络的节点智能部署方法研究

为满足应用系统对无线传感器网络性能,如覆盖连通质量等方面提出的特定需求,研究了概率感知和通信模型下,保障连通覆盖性能的节点部署问题,提出了基于带精英策略的非支配排序遗传算法的节点智能部署方法。仿真结果显示,在满足应用需求的前提下,提出的部署方法与随机部署和网格部署相比,其需要部署的节点数目明显较少;并且,该方法能得到一组反映目标间制约关系的非支配解,可供用户直观地在多个目标之间进行权衡,并折衷选择部署方案。     

云计算在中小企业中的应用价值研究

本文系统介绍云计算的概念和特征,分析云计算层次架构与服务模式,剖析云计算为中小企业发展带来的机遇和挑战,得出中小企业应用云计算技术可行的结论,提出了中小企业云计算实施方案。     

装备技术需求多方案优选方法研究

针对单一优选准则带来的装备技术需求多方案优选结果的片面性,建立了由需求满足度、技术先进程度、技术重要度和技术成熟度等构成的指标体系,实现了装备技术需求的多视角综合优选,克服了单一准则下优选方案的偏差。最后通过示例验证了方法的可行性。     

Dynamics of satellite with deployable rigid solar arrays

This research is concerned with the dynamic modeling of satellite with deployable solar arrays equipped with strain energy hinges (SEH). The SEH is a new deployment device consisting of a strip tape measure, which utilizes the buckling behavior of a thin curved shell to produce nonlinear dynamic characteristics during deployment of solar arrays. For dynamic simulation, the SEH is assumed to be a massless-nonlinear elastic member and the solar panels are assumed to be rigid bodies which are connected by the SEHs. The planar deployment is of interest in this study since the deployment of solar arrays mainly occurs in a two-dimensional plane. In deriving the equations of motion, we developed a new systematic approach suitable for the simulation of solar array deployment in space. The simulation results were compared to the ground experimental results obtained at the laboratory of Korea Aerospace Research Institute. In the ground experiments, the hub of the solar arrays was attached to the frictionless rotational bearing, and the solar arrays were hanged by bungee cables. Even though the dynamic model was derived for the space deployment of the solar arrays, the simulation result corresponding to the solar array deployment was similar to the ground experimental results thus validating the simulation model developed in this paper.     

网络化制造资源预配置模型及其实现方法研究

在网络化制造资源配置中,资源的预配置是优化配置的前提,针对制造资源预配置问题,建立了涵盖LMU-PMU映射和PMU评价、筛选两个子过程的制造资源预配置过程模型;针对两个子过程,分别给出了LMU-PMU映射流程,建立了PMU评价体系,并研究了基于层次分析法的PMU评价、筛选方法.最后,针对某候选PMU集合的评价,以具体实例验证了评价方法的实用性.     

一种虚拟化深度包检测部署机制

网络功能虚拟化转变了网络架构和网络业务的部署。在网络功能虚拟化架构中,实现虚拟化深度包检测只需在传输路径上进行一次扫描,但高效部署深度包检测功能引擎成为难题。将深度包检测功能部署问题形式化为线性规划问题以满足约束条件,并提出一种基于代价最小的贪婪算法和优化的贪婪算法来解决深度包检测功能部署问题。该算法对部署代价和网络资源代价进行折衷,实现了最小化的部署代价。实验结果表明,所提算法能够实现深度包检测功能部署并取得近似最优解。     

Performance model for IEEE 802.11s wireless mesh network deployment design

This paper presents a performance model developed for the deployment design of IEEE 802.11s Wireless Mesh Networks (WMN). The model contains seven metrics to analyze the state of WMN, and novel mechanisms to use multiple evaluation criteria in WMN performance optimization. The model can be used with various optimization algorithms. In this work, two example algorithms for channel assignment and minimizing the number of mesh Access Points (APs) have been developed. A prototype has been implemented with Java, evaluated by optimizing a network topology with different criteria and verified with NS-2 simulations. According to the results, multirate operation, interference aware routing, and the use of multiple evaluation criteria are crucial in WMN deployment design. By channel assignment and removing useless APs, the capacity increase in the presented simulations was between 230% and 470% compared to a single channel configuration. At the same time, the coverage was kept high and the traffic distribution fair among the APs.     

Adoption barriers of network layer protocols: The case of host identity protocol

With increasing societal dependence on the Internet and new application areas emerging, the need for securing communications and identifying communication partners is expected to increase. However, the original Internet architecture is lacking these functionalities, and most of the protocols proposed to fix these issues have not been widely deployed. Often one of the reasons for such failure is that protocol designers have insufficient understanding of the potential adopters’ economic incentives so one may end up designing protocols based on false or inaccurate assumptions. In this paper, we analyze the Host Identity Protocol (HIP) from this viewpoint. Based on 19 expert interviews, we identify six main reasons why HIP has not been widely deployed yet. Most importantly, (1) the demand for the functionalities of HIP has been low. Where demand would have existed, substitute solutions have been favored because (2) they were earlier on the market, (3) they have relative advantage due to some design choices of HIP, (4) HIP lacks early adopter benefits necessitating costly coordination among multiple stakeholders in public deployment scenarios, and (5) people have misconceptions about the deployability of HIP. Additionally, (6) the research-mindedness of HIP developers has lead to strategic mistakes and non-optimal design choices from the perspective of deployment. We also suggest strategies that HIP developers could take to foster the adoption of HIP. Besides providing value to HIP developers, the results propose some new adoption barriers and deployment strategies that could be taken into account when designing new protocols. Finally, the article also provides a template that could be followed when studying the feasibility of other protocols.