浅析交换机自动维护技术

当今社会,信息技术迅猛发展,网络也渗入到我们生活的一点一滴,人们对于网络的依赖也越来越多。网络以其自身独到的优势在社会中扮演着极其重要的角色。网络中的信息量很庞大,而且所涉及的范围广泛,其传播速度也及其之快。所以网络在人们的日常生活中扮演着不可或缺的角色。交换机是网络的重要组成部分,所以它在网络中发挥着极大的作用。因此,交换机的维护、管理、维修就显得越发重要。而本文将从交换机的维护技术做出叙述。     

网络交换机与路由器的比较与选择

计算机网络化是计算机发展的一个重要方向。在构建局域网中如何根据需要与可能,选择网络交换机与路由器是关系到网络性价比的一个关键因素。文章对二层交换机、三层交换机和路由器这三种技术的工作原理和机制进行了比较分析,并根据建网目标和建设条件,从性价比的角度给出了适宜的技术选择。     

浅析程控交换机管理与维护

程控交换机是地震通信网的核心部分，为了延长程控交换机的使用年限，减少故障，必须定期对程控交换机的维护，掌握常见故障的维护方法。     

惠普交换机悄然进中国

快速的增长主要取决于四年前的两项决定:发展以太网技术和专注于企业网市场。     

3COM交换机技术及应用

本文介绍了3COM Superstack ⅡSwitch 3300 的主要特性及其在局域网中的实际应用，评述了冗余网络的构造等问题。     

交换机常见的故障及维护

对交换机的工作原理及常见的软、硬件故障做了简介。     

网络交换机的安全威胁与防范

网络交换机是一种网络扩大设备,它可以帮助在原有有限网络接口的基础上增加众多的连接端口,增加局域网终端的连接数量.因此,无论在政府机关、企事业单位、高校还是在各个科研单位中,随着网络规模的不断扩大,这种网络扩大设备的使用也变得越来越多.但是,政府、科研单位、企业等都属于具有一定保密性质的单位,他们的内部数据不能被泄露,否则将可能给他们带来不可预计的损失,因此网络交换机的安全变的非常重要,要充分做好网络交换机的防范工作.本文的重点就是讲述网络交换机的安全威胁以及防范措施.     

浅析网络交换机的网络应用

网络交换机的概念和原理 交换(switching)是按照通信两端传输信息的需要,用人工或设备自动完成的方法.把要传输的信息送到符合要求的相应路由上的技术统称.广义的交换机(switch)就是一种在通信系统中完成信息交换功能的设备.     

NETGEAR桌面型千兆交换机问世

NETGEAR公司率先将大型企业网络技术引入到小型办公室和SOHO网络中来,推出了业界第一款8端口低价位高性价比的千兆位交换机——GS108。NETGEAR公司的GS108交换机是一款可以提供8个全线速交换的10/100/1000Mbps自适应的非网管型铜缆千兆交换机。全线速,16Gpbs无阻塞背板的交换保证了即使在网络业务量最大的情况下也能实现没有     

浅谈金融业信息系统等级保护工作的常态化简

近年来,信息系统信息安全等级保护制度已成为我国一项基本国策,如何持续地做好将信息系统等级保护工作,提高自身信息系统安全防御能力,已成为金融机构必须关注的问题。本文主要结合人民银行实际的信息安全管理工作,对单位开展信息安全等级保护工作的情况进行了分析,并就如何实现信息系统等级保护工作常态化提出了几点想法。     

Macroergonomics: analysis and design of work systems

Attending to the larger system components such as organizational design and management is not novel for ergonomists. In Europe, there has been a strong tradition to investigate ergonomic problems within a holistic, systems context. "Macroergonomics" builds upon this tradition by providing specific methods and tools that yield large-scale results. It is believed that meaningful and large-scale results are needed in today's competitive and turbulent work environments. Macroergonomics is defined, its history is uncovered and focus is given to a key methodology, macroergonomic analysis and design. Case studies are used to validate the method and illustrate that performance results in the 60-90% range can be expected.     

浅谈某教育城域网安全等级保护实施

互联网的高度发展给人们的生活与工作带来了很多的便捷,也给教育带了全新的变革,但是网络安全的问题也突显现,教育城域网也不在一片净多,黑客攻击、病毒传播、信息泄漏、主页篡改等信息安全事故时有发生,防止网络信息安全事故发生,对信息系统进行安全等级保护,达到规范标准已经迫在眉睫.     

A case study on the relationship between neuro-sensory work and work load

A series of experiments were carried out to obtain data on the psycho-physiological reactions of train conductors/operators while at work. From the results, it can be said that: (1) There exists a strong and positive correlation between heart rate variations and those of CFF, (2) heart rate and CFF variations at work became lower as working hours increased, (3) the driver's deterioration of the level of psycho-physiological reactions' drivers showed on going is higher than that of returning, (4) Driving at midnight or in the early morning seems to cause a significantly larger reduction of brain related arousal level.     

E-mail characteristics,work performance and distress

The purpose of the study is to examine how e-mail affects work performance. E-mail communication studies have aroused both praise and query regarding the suitability, appropriateness and effectiveness of electronic messages in information management. Less is known about the effects of e-mail on work performance. We consider (1) which e-mail features affect work performance; (2) whether these features are differentially associated with positive (work effectiveness) or negative (stress and distress) side-effects; and (3) whether individual- and organizational-level characteristics are associated with positive and/or negative work performance. Using a secondary level analysis based on the Pew and American Life sample we show that extent, content, and increased volume of e-mail are (a) more frequently reported by managers than by non-managers (b) age, gender, marital status and education can become a critical issue (c) the amount of e-mail received and sent is positively related to work performance. These findings suggest that assessing the costs and benefits of electronic communication should cover individual features as well as e-mail-related features to assess their impact on work performance.     

The activation of mechanisms linking judgements of work design and management with musculoskeletal pain

The report of work-related musculoskeletal pain may be related to worker evaluations of the design and management of work through two mechanisms: one biomechanical and the other stress-related. This study of engineering workers (n = 204) explored the validity of these mechanisms using sequential logistic regression. Analyses suggested that workers' ratings of the adequacy of the design and management of their work were related to their report of work-related musculoskeletal pain. However, the mechanisms appeared to be activated in certain conditions. The reporting of pain in the upper body was both biomechanically- and stress-related, whereas that in the lower body was only biomechanically-related. It is argued that the mechanism activated appeared to be determined by the anatomical location of the pain, and probably the variance shared between the different aspects of work design and management, on the one hand, and the mechanical load of the job, on the other.     

Test-retest reliability and concurrent validity of a web-based questionnaire measuring workstation and individual correlates of work postures during computer work

INTRODUCTION: "Ergonomic" questionnaires are widely used in epidemiological field studies to study the association between workstation characteristics, work posture and musculoskeletal disorders among office workers. Findings have been inconsistent regarding the putative adverse effect of work postures. Underestimation of the true association might be present in studies due to misclassification of subjects to risk (i.e. exposed to non-neutral working postures) and no-risk categories (i.e. not exposed to non-neutral working postures) based on questionnaire responses. The objective of this study was to estimate the amount of misclassification resulting from the use of questionnaires. METHODS: Test-retest reliability and concurrent validity of a newly developed questionnaire was assessed. This questionnaire collects data on workstation characteristics and on individual characteristics during computer work (i.e. work postures, movements and habits). Pictures were added where possible to provide visual guidance. The study population consisted of 84 office workers of a research department. They filled out the questionnaire on the Internet twice, with an in-between period of 2 weeks. For a subgroup of workers (n=38), additional on-site observations and multiple manual goniometer measurements were performed. RESULTS: Percentage agreement ranged between 71% and 100% for the test-retest analysis, between 31% and 100% for the comparison between questionnaire and on-site observation, and between 26% and 71% for the comparison between questionnaire and manual goniometer measurements. For 9 out of 12 tested items, the percentage agreement between questionnaire and manual goniometer measurements was below 50%. CONCLUSIONS: The questionnaire collects reliable data on workstation characteristics and some individual characteristics during computer work (i.e. work movements and habits), but does not seem to be useful to collect data on work postures during computer work in epidemiological field studies among office workers.     

A method for evaluation of manual work using synchronised video recordings and physiological measurements

Industrial interventions that focus on increased productivity may impair the ergonomics, on a workstation or individual level. This paper presents a method that characterises work time consumption and physical work load of manual work, using video recordings synchronised with physiological measurements of, e.g. muscular activity, and postures. The underlying idea was that it is possible to amalgamate technical and human aspects resulting in a synergetic evaluation. The method was developed through two case studies within the Swedish automotive industry, where manual materials handling was studied. A methodological result was that the synchronising procedure was sufficiently precise to allow work activities to be assigned significantly different levels of physical work load. These different levels may be used to predict physical work load in the design and change of production systems. It was concluded that the method is accurate enough to be a useful tool in industrial interventions.     

A systemic framework for work accident analysis in judicial procedures

This article intends to demonstrate the need for changing analytical methods used in work accidents for judiciary purposes. It proposes to replace the commonly used simplistic model of unsafe act performed by workers, which has been used to invoke admission of guilt on the part of the victim of an accident, without attacking its root cause or preventing future events. The systemic framework for work accident analysis aims to shift the focus of the investigation, analyzing in a broad sense and carefully investigating circumstances by using a sociotechnical approach, especially when it comes to evaluating human performance in real work circumstances, as opposed to the evaluation based on prescribed tasks. Ergonomic modeling techniques are used for a better understanding of real work situations. We use a real accident to demonstrate how an accident analysis report performed by a legal expert witness, using a systemic framework, was able to prevail in the labor court. © 2011 Wiley Periodicals, Inc.     

Fatigue and human reliability revisited in the light of ergonomics and work psychopathology

In the process control human-beings are actually information processors, solving many problems, especially covariance-problems which involve various interconnected and interactive factors.

The purpose of this experiment was to investigate the types of cognitive strategy and information-processing procedure used in solving covariance-problems, and to evaluate and determine the best strategy.

Fifty-five subjects participated in the experiment to solve two-factor covariance-problems. Verbal protocols and structural analysis were used to record and analyse the cognitive processes of covariance-problem solving. Verbal protocols were coded and analysed to differentiate the basic operators and thence explore the various strategies.

The results indicated that under two-factor covariant conditions, there were nine kinds of cognitive strategy. The 'biconvex-lens’ strategy was the most effective. All nine strategies can be classified into three categories, trial-and-error, analytic and intuitive.

This experiment research was the first study on cognitive strategies in solving covariance-problems. New topics for further study are put forward.