论IT系统的性能瓶颈及解决方案

桌面和服务器环境的一个重要的不同点, 就是服务器环境会对网络性能造成巨大的、意想不到的影响.所以服务器性能是现在广泛注意的一个问题.文章分析了一些可能影响服务器性能的原因,并且针对性地提出了若干解决方案.     

基于网络编码的网络QoS性能分析

网络编码的核心思想是允许网络节点对传输信息进行编码处理,运用网络编码能够提升网络吞吐量、均衡网络负载和提高网络带宽利用率等.介绍了网络编码的几种主要算法和机制,并对这些算法在提高网络QoS性能方面进行了仿真和比较研究.     

梅钢大中型网络IP地址的管理

IP地址是网络资源的一部分,也是网络管理最基本的要素之一。介绍了梅钢IP地址的管理经验,大中型网络IP地址的管理思路,以及通过IP地址管理在提高网络安全,追踪网络病毒中发挥的一定作用。     

几种先进热作模具钢的性能分析

本文介绍了当今国内外几种先进的热作模具钢及相关技术性能，通过性能数据的对比分析了解新材料的运用特点。     

多媒体视听教学网络系统

多媒体视听教学网络系统是多媒体技术与网络技术发展的产物,它涵盖了电脑教室、语音教室及电教室的大部分功能,目前在国内外正得到广泛应用．本文主要介绍几种目前流行的多媒体教学网络的功能特点及应用情况,向读者展示一种全新的现代化教学手段．     

多媒体视听教学网络系统

多媒体视听教学网络系统是多媒体技术与网络技术发展的产物,它涵盖了电脑教室,语音教室及电教室的大部分功能,目前在国内外正得到广泛应用,本文主要介绍几种目前流行的多媒体教学网络的功能特点及应用情况,向读者展示一种全新的现代化教学手段。     

企业网络隔离方案探讨

分析威胁网络安全的主要因素及网络隔离对网络风险的防范作用。根据几种网络隔离技术的特点和企业网的应用需求，提出企业网中3个典型网络边界上的网络隔离方案，展望网闸隔离技术在企业网中的应用前景。     

仿真中性网络对于电机故障检测的应用和设计

仿真中性网络显现技术已成功地应用在许多领域，如故障检测，控制、信号处理和其它方面。本文给出用前馈仿真中性网络执行电动机检测的一般设计考察。文章首先讨论几种非损伤性故障检测技术，包括参数估值法，专家估值法等，然后讨论仿真中性网络法。随后，对前馈网络和反向传播训练及其伪码进行简要评述。后面几节解释了一些中性网络的设计考察，如网络性能、网络的实现，训练数据组的规模、训练参数值的分配以及停止准则。最后叙述     

金属粉末气体雾化制备技术的研究现状与进展

气体雾化技术是生产金属及合金粉末的主要方法。本文依据气体雾化中喷嘴的结构特征，分析了国外几种具有工业实用意义的雾化技术的原理、性能与发展状况，评述了其优缺点和应用情况。     

三种优化网络性能的方法

八十年代中期,信息系统安装EthenrnetLAN,以太网提供10Mbps带宽似乎接近于无穷大。当时能力很低的台式计算机不可能持续占用哪怕是几分之一的这个带宽。网络的信息流主要是程序产生的细小数据流。网络活动只限于工作组范围内,尚不成熟的网络应用软件     

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)     

Impact of Federal Environmental Requirements on Proposed Highway or Bridge Project

Prior to construction of a bridge or highway, the National Environmental Protection Act (NEPA) requires an evaluation of the effect of the project on the human environment. The purpose of NEPA is to require the head of the federal agency that is committing funds to the project to consider its actions before deciding to proceed with the project. This paper will analyze the general provisions of NEPA to remove some of the mystery related to the environmental concerns raised by bridge or highway projects and to emphasize to transportation planners that these concerns must be addressed prior to beginning a major bridge or highway project. The intent of this paper is to provide some guidance to transportation planners in light of these statutes as they begin the planning stages for highway and bridge projects.     

Damage Detection through Analysis of Modes in a Partially Constrained Plate

The need for aircraft, both military and civilian, to serve longer and cost less to operate is ever present. The ability to potentially extend service life and reduce operating and maintenance costs are key factors in the many choices with aircraft programs. The field of structural health monitoring attempts to reduce labor and cost by allowing technicians to monitor selected properties of an aircraft’s structure to detect impending failure. This research examines methods to detect damage to a thermal protection system tile using representative aluminum plates. Plates are subjected to modal analysis in single and joined conditions in an attempt to provide the capability of sensing damage to a tile on the surface of a vehicle whereas the sensors remain on the substructure of the airframe. Jointly, the development of a means to model the system using finite-element techniques is explored. It is found that the finite-element modeling technique produces correlating modal frequencies within a 7.19% worst case average when compared to the physical tests. This leads to the ability to compare mode shapes and frequencies to detect damage in such a system.     

固定式精炼炉的改进

江西铜业集团公司贵溪冶炼厂(简称贵冶)固定式精炼炉,因其在设计上存在缺陷及生产工艺的改变,不能满足生产的需要。在生产实践中积累经验后,将其进行技术改造。将改造前后的不同状况列出进行比较,从而阐述改造后取得的效果,最后列举出贵冶固定式精炼炉目前还存在的不合理因素,并设计出解决的方案,做到工作持续推进。     

Rapid Bridge Replacement under Emergency Situation: Case Study

The terrorist attack on September 11, 2001, and subsequent potential threats to the United States transportation systems have presented an urgent need to elevate the security of the transportation infrastructure and to develop emergency response plans to quickly react to the possible consequences of an extreme event. Highway bridges, as critical components of the nation’s transportation network, have been brought to closer attention by government agencies. A research project was conducted to identify strategies and technologies to restore the use of a damaged bridge quickly. One of the tasks associated with the research was to perform several case studies of previous bridge replacements following extreme events. These events include explosion and fire caused by vehicle impact, vessel collision with a bridge, and damage caused by flood and earthquake. By studying the cases, the research team seeks to identify and expand on lessons learned and address which actions did and did not work well given the circumstances of the incident. These lessons have great value to the people who need to develop and implement an emergency response plan.     

Probability of Project Completion Using Stochastic Project Scheduling Simulation

This paper introduces a software, Stochastic Project Scheduling Simulation (SPSS), developed to measure the probability to complete a project in a certain time specified by the user. To deliver a project by a completion date committed to in a contract, a number of activities need to be carried out. The time that an entire project takes to complete and the activities that determine total project duration are always questionable because of the randomness and stochastic nature of the activities’ durations. Predicting a project completion probability is valuable, particularly at the time of bidding. The SPSS finds the longest path in a network and runs the network a number of times specified by the user and calculates the stochastic probability to complete the project in the specified time. The SPSS can be used by a contractor: (1) to predict the probability to deliver the project in a given time frame and (2) to assess its capabilities to meet the contractual requirement before bidding. The SPSS can also be used by a construction owner to quantify and analyze the risks involved in the schedule. The benefits of the tool to researchers are: (1) to solve program evaluation and review technique problems; (2) to complement Monte Carlo simulation by applying the concept of project network modeling and scheduling with probabilistic and stochastic activities via a web based Java Simulation which is operateable over the Internet, and (3) to open a way to compare a project network having different distribution functions.     

Retrofit Storm Water Retention Volume for Low Impact Development

The concept of low impact development (LID) applies decentralized on-site runoff source control to storm water management. LID is an integration of bioretention and vegetated landscapes to maintain a catchment’s hydrologic and ecological functions. In current practice, the LID implementation is quantified for the specified watershed development. During the dynamic development process, the existing LID facilities have to be improved according to the incremental changes in the watershed. This technical note presents an on-site hydrologic approach to relate the required incremental storm water retention volume to the alteration of surface imperviousness in the tributary area. This approach allows the storm water retention volume to be tailored according to the stage of the watershed development. Cumulatively, the total storage volume can be achieved though multiple stages of the watershed development. The incremental retention volume is found to be related to the local average event rainfall depth. Design charts were produced and normalized by the local average rainfall event depth for generalized applicability.     

Modeling Residual Displacements of Concrete Bridge Columns under Earthquake Loads Using Fiber Elements

Nonlinear dynamic analysis with fiber-element models is now widely used to assess the seismic response of bridge structures. The ability of such models to accurately simulate response parameters for characterizing the postearthquake condition of bridges, namely residual displacements, is assessed by comparison of analyses of dynamically loaded reinforced concrete bridge columns to experimental data. The models are unable to capture residual displacements, and the cause of the inability to capture residual displacements is investigated through dynamic analysis of fiber-element and single-degree-of-freedom (SDOF) models. A certain type of pinching present in the numerical hysteretic response shape is found to lead to poor residual displacement simulation both in the SDOF models and in fiber-element models. When eliminating this pinching, improvements to residual displacement simulation are found. A modified concrete constitutive model representing damage accumulation from cyclic loading is implemented for the fiber-element analysis that incorporates changes to reloading behavior when moving from high tensile strain back to compression. Analysis using the modified concrete constitutive model leads to improvements in the ability of the fiber-element model to capture residual displacements.     

Review of Repairing your marriage after his affair: A woman’s guide to hope and healing.

Reviews the book, Repairing your marriage after his affair: A woman's guide to hope and healing by Marcella Bakur Weiner and Armand DiMele (1998). This book addresses the difficult task of reestablishing trust in the marriage after an affair and offers specific guidelines for discussions that aid the healing process. The authors recommend exercises that help the couple break down the barriers to intimacy and cultivate greater happiness in the marriage. They also include a chapter for handling children during this critical period and suggest ways to minimize the trauma to them. Their advice is sound and their suggestions for recovery quite practical and valuable to any woman struggling to come to terms with her partner's affair. The authors provide some helpful information to the woman contending with this problem and hoping to continue in the marriage. It is likely to appeal most to the woman reluctant to enter individual or couple therapy with her husband, yet needing some help in coping with the intense emotions at this confusing time; it can help her in deciding whether to leave or stay in the marriage. The book can also be used as an adjunct to therapy for women already in treatment who might want supplemental reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Particle Swarm Optimization for Preemptive Scheduling under Break and Resource-Constraints

This paper introduces a particle swarm optimization (PSO)-based methodology to implement preemptive scheduling under break and resource-constraints (PSBRC) for construction projects. The PSBRC under study allows the preemptive activities to be interrupted in off-working time and not to resume immediately in the next working period because all the limited resources are to be reallocated during a break. The potential solution to the PSBRC, i.e., a set of priorities deciding the order to start the activities or restart the interrupted activities, is represented by the multidimensional particle position. Hence PSO is applied to search for the optimal schedule for the PSBRC, in which a parallel scheme is adopted to transform the particle-represented priorities to a schedule. Computational analyses are presented to verify the effectiveness of the proposed methodology. This paper provides an attempt to make use of preemption and break for the resource-constrained construction project with the objective of minimizing project duration.