V5接口的测试方法

本文道德简要介绍了Ｖ５接口的基本发展情况，以及各种测试方法和测试类型。然后详细论述了Ｖ５接口协议的一致性测试，并以检测ＨＶ５ＰＣ系统为例，深入讨论这种测试方法的原理。     

玩具中激光器和发光二极管辐射测试方法

玩具中激光器和发光二极管发出的过量辐射会导致人眼和皮肤的严重损伤,尤其容易对儿童造成伤害。本文论述了激光器和发光二极管辐射关键参数的测试方法和测试步骤,并对样品进行了具体测试。     

Optimal safety stock levels of subassemblies and manufacturing components

In order to control the time to market and manufacturing costs, companies produce and purchase many parts and components before receiving customer orders. Consequently, demand forecasting is a critical decision process. Using modular product design and super bills of materials are two effective strategies for developing a reliable demand forecasting process. They reduce the probability of stockouts in diversified production contexts. Furthermore, managing and controlling safety stocks for pre-assembled modules provide an effective solution to the problem of minimizing the effects of forecast errors. This paper develops, evaluates, and applies innovative cost-based analytical models so that the optimal safety stock of modular subassemblies and components in assembly to order and manufacturing to order systems, respectively, can be rapidly quantified. The implementation of the proposed models in two industrial case applications demonstrates that they significantly reduce the safety stock inventory levels and the global logistical cost.     

The business case of a network that serves both public safety and commercial subscribers

Deploying a single nationwide broadband wireless network to serve all public safety users would have great advantages over the existing fragmented public safety systems. A nationwide system could be created to serve both public safety and commercial subscribers, which would allow a provider to exploit important economies but force it to meet the more costly requirements of public safety. This paper analyzes the viability of a public-private partnership that serves public safety and commercial subscribers from a for-profit provider's perspective. A model is presented that estimates the net present value (NPV) of a wireless network by calculating costs based on the number of cell sites required and revenue based on the projected number of subscribers acquired. The model is applied to both a network that serves only commercial subscribers on 10 MHz of 700 MHz spectrum and a public-private partnership that serves commercial subscribers and public safety personnel on 20 MHz of 700 MHz spectrum. It is found that NPV is greater for the public-private partnership than for the commercial-only network for any population density, which shows that the value of 10 MHz of spectrum exceeds the cost of meeting public safety requirements. Furthermore, the paper demonstrates that NPV/cell increases with population density, so urban areas are profitable and rural areas are unprofitable. The paper demonstrates that a partnership covering 94% of the US population breaks even because the most urban 56% of population subsidizes coverage for the next 38%. If initial deployment is subsidized, a financially sustainable public-private partnership can serve much more than 94%. Additionally, it is shown that allowing urban municipalities to opt-out of the partnership can significantly increase the subsidies required.     

Net Neutrality in Europe: Desperately seeking a market failure

Net Neutrality has become the focus of attention in the regulatory debate on the Internet. This article attempts to strip down the debate to its bare essential. It identifies two main types of Net Neutrality obligations that have been put forward and assesses what type of potential concerns they may be designed to address. It concludes that while some of these concerns may be important it remains doubtful (at least in Europe) that an ex ante per se rule, such as those proposed under the Net Neutrality term, is the best way to address them.     

Multihoming, content delivery networks, and the market for Internet connectivity

Peering points between different Internet service providers (ISPs) are among the bottlenecks of the Internet. Multihoming (MH) and content delivery networks (CDNs) are two technical solutions to bypass peering points and to improve the quality of data delivery. So far, however, there is no research that analyzes the economic effects of MH and CDNs on the market for Internet connectivity. This paper develops a static market model with locked-in end users and paid content. It shows that MH and CDNs create the possibility for terminating ISPs to engage in monopolistic pricing towards content providers, leading to a shift of rents from end users and content providers to ISPs. Implications for future innovations are discussed.     

安全活动对物流企业绩效作用的实证分析

本文以物流企业为调查对象进行问卷调查,通过Bootstrapping和结构方程模型的路径分析,分析了物流安全活动对成本控制,运输效率和企业绩效之间的影响关系.同时,以路径分析结果为基础,提出了推广物流安全实践活动和提高物流企业绩效的意义.结果表明,安全运输实践及安全运输预防管理对成本控制和运输效率都有着显著的积极影响,运输手段安全管理对成本控制有着显著的积极影响,而运输手段安全管理对运输效率产生的影响力在5％的显著性水平下不显著,成本控制对运输效率也产生了显著的积极影响关系,成本控制和运输效率对企业绩效也都有着显著的积极影响.     

城市安全:生命的呼唤

近年来,城市事故接二连三地发生,反映出城市安全问题的严重性.本文分析了出现问题的主要原因,发出理性的呼吁:城市安全问题必须给予高度重视.城市规模不是越来越大越好;城市建筑不是越来越高越好;城市汽车不是越来越多越好;城市标准不是越来越豪华越好.     

Optimizing service-level and relevant cost for a stochastic multi-item cyclic production system

A multi-item make-to-order production system in a stochastic environment is analyzed. Assuming a common cycle production approach, the impact of safety stock, cycle time, demand, processing time and setup time on service-level and total relevant cost (holding, setup and backorder cost) is determined. To illustrate this relationship a trajectory for the service-level with respect to the relevant cost (holding and setup) is presented. Furthermore algorithms to calculate the cycle time which leads to maximum service-level at constant safety stock and to calculate the pair cycle time and safety stock which minimize total relevant cost are introduced.     

中国银行业的市场结构与银行绩效关系研究——基于33家商业银行面板数据的实证检验

以33家商业银行1997—2004年的数据为研究对象,以赫芬达尔指数作为衡量市场结构指标,本文对中国银行业市场结构与银行绩效关系进行了研究。研究结果表明,市场集中度降低对四大国有商业银行盈利能力没有产生显著性影响,但削弱了其他股份制商业银行和城市商业银行的盈利能力。市场集中度与所有银行净利息边际存在显著的负相关关系,不能跨地域经营的城市商业银行净利息边际显著低于其他商业银行。因此应该适度放开城市商业银行经营的地城限制。并防止过度竞争。