Effective lightning protection schemes for distribution line

The causes of lightning outage are subdivided into direct lightning strokes and induced lightning strokes, which are identified by the characteristics of the lightning overvoltage. In the past, lightning protection devices were directed mainly toward the latter, and attention has been focused on the installation of lightning protection devices, ground wires, and reinforcement of insulators. However, lightning outages continue to occur. Thus it is extremely important to clarify the fault characteristics of lightning surges and to study the effectiveness of various lightning protection devices by considering both direct lightning stroke and induced lightning stroke in order to prevent lightning outage in the future. In this research, the electromagnetic transients program (EMTP) has been applied to the direct lightning stroke, and the induced lightning outage analysis program for multiple conductor systems has been applied to the induced lightning stroke to study the effectiveness of lightning protection devices provided by combination of various lightning protection devices. The most effective lightning protection schemes are analyzed and evaluated based on verification tests on the full scale models as well as economic considerations.     

CIMS装配和拆卸生产线的可靠性分析

本文对ＣＩＭＳ装配线和拆卸线的可靠性问题进行研究。文中分析了它们的运行状况，求出了两种生产线的稳态可用度，并用一个例子加以说明。     

可压缩体的滑移线场理论

从理论上建立了可压缩体的滑移线场理论，并给出了解析实例。研究表明：在平面应变条件下，可压缩体内的两族滑移线不仅不正交，而且随着平均正应力的不同而变化；可压缩体的平面应变问题可以直接采用现有的致密体的滑移线场来求出。     

A bidding decision index for construction contractors

Results from applying the model on a sample of contractors, the majority of whom were international and operating in Egypt, reinforces the credibility of the developed methodology, claim the authors.     

非串行生产线的建模,分析及设计

本文利用等效工作站理论和工件流平衡原理，推导出非串行离散事件生产线可以等价于串联系统，并归结为装配和拆卸两条定理，解决了系统的建模、分析与设计问题。     

一种考虑不同期合闸的行波合闸保护新方法

当线路末端故障时，行波在线路末端的反射情况比较复杂，反向电流行波的极性有可能与正向电流行波的极性相反，而此时测距结果又与线路无故障时相同。因此，会造成行波测距式与行波极性比较式合闸保护的不正确动作。根据行波的折、反射理论，分析出当线路无故障时正向电流行波仅在线路末端发生反射，且电流行波的反射系数为-1，而当线路存在故障时，正向电流行波将在故障点发生反射，无论故障是否在线路末端，电流行波的反射系数都不会是-1。根据这一特征，提出了一种新的行波合闸保护方法。从原理上保证了在各种情况下保护都可以正确动作，大量的电磁暂态仿真结果也证明了这一点。     

200 万t链箅机-回转窑球团生产线快速达产实践

介绍了邯钢200万t链箅机-回转窑酸性氧化球团生产线的工艺特点和主要设备,以及建成投产后试生产的有关情况。通过周密的部署和安排,该生产线实现了40天快速达产的目标。     

Directional features in online handwriting recognition

The selection of valuable features is crucial in pattern recognition. In this paper we deal with the issue that part of features originate from directional instead of common linear data. Both for directional and linear data a theory for a statistical modeling exists. However, none of these theories gives an integrated solution to problems, where linear and directional variables are to be combined in a single, multivariate probability density function. We describe a general approach for a unified statistical modeling, given the constraint that variances of the circular variables are small. The method is practically evaluated in the context of our online handwriting recognition system frog on hand and the so-called tangent slope angle feature. Recognition results are compared with two alternative modeling approaches. The proposed solution gives significant improvements in recognition accuracy, computational speed and memory requirements.     

Gorillas (Gorilla gorilla) and Orangutans (Pongo pygmaeus) Encode Relevant Problem Features in a Tool-Using Task.

Two important elements in problem solving are the abilities to encode relevant task features and to combine multiple actions to achieve the goal. The authors investigated these 2 elements in a task in which gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus) had to use a tool to retrieve an out-of-reach reward. Subjects were able to select tools of an appropriate length to reach the reward even when the position of the reward and tools were not simultaneously visible. When presented with tools that were too short to retrieve the reward, subjects were more likely to refuse to use them than when tools were the appropriate length. Subjects were proficient at using tools in sequence to retrieve the reward. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

唐山建龙900mm冷轧机组的工艺与设备

较系统地介绍了我国第1条国产化的中宽带钢冷连轧生产线，即唐山建龙钢铁控股有限公司900mm冷连轧生产线的工艺流程、主要设备组成及技术特点。重点介绍了900mm 4机架六辊轧机的技术参数、性能特点及自动控制系统。该生产线投产以来，取得了较好效果。