VLAN技术浅析

对VLAN技术进行了剖析,阐述了VLAN技术在组建局域网中的作用、划分方式及VLAN中配置的常用技术.     

可堆叠VLAN技术在城域网中的应用研究

本文阐述了可堆叠VLAN技术,针对城域网中的VLAN资源不足、保护用户VLAN ID和用户端口汇聚进行了较深的研究和有效的解决,描述了支持可堆叠VLAN技术的硬件设计方案,并以汇聚型用户介绍了以太网交换机数据处理流程,最后,简要讨论了可堆叠VLAN技术的应用前景。     

VLAN技术在三层交换机中的应用

主要分析了以太网中使用VLAN技术进行网段划分所带来的优势,以及VLAN子网之间通信的问题.详细介绍了VLAN技术,第三层交换技术和三层交换机的种类.最后,给出了VLAN技术在三层交换机中的应用.     

VLAN技术在校园网中的应用

虚拟局域网（VLAN）技术是目前网络技术中的一项重要技术。文章主要介绍了VLAN技术原理、优点及其划分,阐述了VLAN技术在管理维护校园网系统中所起的作用以及在校园网中用交换机配置VLAN的步骤,解决了校园网中存在的广播风暴和安全性问题。     

基于VLAN技术在高校校园网建设中的应用

随着校园网规模的不断扩大,网络信息需求的不断增加,VLAN技术被运用到校园网的建设中。VLAN是在物理网络的基础上通过技术手段按照管理功能建立的逻辑网络;VLAN技术的应用有效避免了广播风暴;增强了局域网的安全性。本文描述了VLAN的基本概念和原理,VLAN的种类划分及其特点,并结合实际分析了VLAN技术在校园网建设中的应用。     

采用VLAN增加企业内部网安全性

本文介绍了VLAN技术,并通过VLAN在企业中的应用实例,探讨了采用VLAN增强企业内部网络的安全性的方法和VLAN配置过程.     

虚拟局域网技术浅谈

当今世界是一个高度信息化的社会,网络时时刻刻地在影响着我们的生活和工作。给我们的工作生活带来了极大的变革,各种组网技术和手段层出不穷。VLAN作为新兴的技术,在组网过程中得到了广泛的应用。本文从虚拟局域网（VLAN）的基本概念和主要功能,VLAN的划分方式,建立VLAN的交换技术,VLAN的配置方式,VLAN成员信息的传递方式,VLAN之间路由与通信方式等方面,分析与概述了虚拟局域网技术。深入浅出地阐述了虚拟局域网技术的基本原理和工作过程,以及在实践中的指导作用。     

采用VLAN增加企业内部网安全性

本文介绍了VLAN技术,并通过VLAN在企业中的应用实例,探讨了采用VLAN增强企业内部网络的安全性的方法和VLAN配置过程。     

动态VLAN和Guest VLAN技术在校园网中的应用

介绍了VLAN技术及其在校园网用户认证中的应用.VLAN技术为解决网络配置和管理提供了良好的方法,随着网络的不断发展,VLAN技术将得到更加广泛的应用.     

基于局域网中VLAN技术应用的研究

虚拟局域网(VLAN)技术是目前局域网中经常使用的一种技术;VLAN技术是在不改变局域网上节点物理位置的基础上,按照功能、部门、应用等因素划分为若干"逻辑工作组";VLAN技术有效避免了局域网中的广播风暴,增强了局域网的安全性。本文介绍了VLAN的概念、原理、优点以及其分类,并实现了VLAN在某高校局域网上的配置和验证方法。     

Integration | Innovation | Inclusion: Values,Variables and the Design of Human Environments

Complexity, complication, contradiction, consumption, confusion, delusion, depression. Opportunity, inspiration, ingenuity, compassion, wisdom. Our world is perplexing, our times are fast moving, and our choices are many. To find an appropriate path is a daunting yet vital challenge that confronts us as individuals, as communities, and as a civilization. How sustainable is our world? How reasonable are our behaviors? The present article is a collection of thoughts on a series of intertwined issues related to the contemporary world, its environmental dimensions, and their present-day problems. The goal is to survey the landscape through a lens of Environmental Design, to provide some perspectives, to raise some questions, and to explore systems, beliefs, and values informing and influencing actions. It is important to consider how people's belief systems influence, inform, and shape actions. This holds true in realms political, spiritual, and cultural. It also proves relevant in the ways in which we imagine, design, develop, and construct our buildings, cities, spaces, and places.

Appropriate solutions to some of our most daunting problems will arise through the concerted efforts, open dialogue, and collective wisdom of the wide array of stakeholders, professionals, politicians, decision makers, and citizens (both engaged and disenfranchised) who have the will and wherewithal to make a difference and to make the world safer, healthier, and better. It seems vital for us to critically examine, and question, our belief systems and their connections to the ways we define, refine, and realize progress. Architecture and Environmental Design, in both a philosophical and a practical sense, reflect as well as form greater aspirations, directions, and events of our times.     

Database management standards: status and applicability

This article presents the current status of existing and emerging ISO, ANSI, and FIPS standards for database management, specifically Database Languages NDL and SQL and Remote Database Access (RDA). It describes the general content of each standard and discusses its applicability, availability, completeness, maturity, stability, existing usage, and known limitations. Where appropriate, it also addresses the availability of conformance test suites and future plans for enhancements and follow-on standardization efforts.     

计算机科学与技术中的系统论与辩证法

本文探讨了计算机科学与技术中的系统论及辩证法,包括物质和意识、联系与发展、时间和空间、理论和实践等范畴以及对立统一、质量互变、否定之否定等基本规律。应用上述理论阐述计算机软硬件系统、操作系统、程序设计语言与算法、计算机网络、计算机软硬件发展等方面存在的基本哲学问题,并将其应用于计算机教学,取得了较好的效果。     

基于RGB-D信息的移动机器人SLAM和路径规划方法研究与实现

移动机器人在各种辅助任务中需具备自主定位、建图、路径规划与运动控制的能力。本文利用RGB-D信息和ORB-SLAM算法进行自主定位,结合点云数据和GMapping算法建立环境栅格地图,基于二次规划方法进行平滑可解析的路径规划,并设计非线性控制器,实现了由一个运动底盘、一个RGB-D传感器和一个运算平台组成的自主移动机器人系统。经实验验证,这一系统实现了复杂室内环境下的实时定位与建图、自主移动和障碍物规避。由此,为移动机器人的推广应用提供了一个硬件结构简单、性能良好、易扩展、经济性好、开发维护方便的解决方案。     

面向大尺寸货物运送的吊车控制方法综述

随着现代化工业和基础设施建设的飞速发展,面向大尺寸货物运送的吊车系统以其高负载能力、低成本的显著优势广泛应用于集装箱搬运、风机安装、飞机机翼机身移动、水轮发电机转子安装、海上钻井平台搭建等诸多重要领域。然而,相对于传统的点质量单摆吊车系统,面向大尺寸货物运送的吊车系统具有更高的欠驱动程度、更强的状态耦合性和更加复杂的非线性,给大尺寸货物高效、安全的运送控制带来严峻挑战。本文首先简单阐述了面向大尺寸货物运送吊车系统不同吊装形式的建模、优势和缺点;然后,详细介绍了点质量双摆吊车系统、分布式质量双摆吊车系统和多吊车协同运送系统控制的研究现状;最后,对面向大尺寸货物运送吊车系统控制的研究现状进行概括,并对可能存在的关键问题和未来的研究方向进行了讨论和展望。     

The national coal-resources data system of the U.S. geological survey

The National Coal Resources Data System (NCRDS) was designed by the U.S. Geological Survey (USGS) to meet the increasing demands for rapid retrieval of information on coal location, quantity, quality, and accessibility. An interactive conversational query system devised by the USGS retrieves information from the data bank through a standard computer terminal. The system is being developed in two phases.Phase I, which currently is available on a limited basis, contains published areal resource and chemical data. The primary objective of this phase is to retrieve, calculate, and tabulate coal-resource data by area on a local, regional, or national scale. Factors available for retrieval include: state, county, quadrangle, township, coal field, coal bed, formation, geologic age, source and reliability of data, and coal-bed rank, thickness, overburden, and tonnage, or any combinations of variables. In addition, the chemical data items include individual values for proximate and ultimate analyses, BTU value, and several other physical and chemical tests. Information will be validated and deleted or updated as needed.Phase II is being developed to store, retrieve, and manipulate basic point source coal data (e.g., field observations, drill-hole logs), including geodetic location; bed thickness; depth of burial; moisture; ash; sulfur; major-, minor-, and trace-element content; heat value; and characteristics of overburden, roof rocks, and floor rocks. The computer system may be used to generate interactively structure-contour or isoline maps of the physical and chemical characteristics of a coal bed or to calculate coal resources.     

基于ISM模型的在线技术支持APP设计与实现

企业在产品更新迭代及创新的过程中，对相关领域技术的需求非常巨大，企业从业者也有众多问题得不到解决，而高校与研究机构在相关领域有众多专家，希望将技术推广并解决从业者的问题。通过搭建一个平台，促成企业、企业从业者和专家三者之间的交流与合作。平台采用ISM模型，基于Android平台，采用分布式架构，依赖Django服务器、MySQL数据库。系统功能包括发布需求、智能推荐、提供线索、专家约谈等功能，为企业从业者、专家、企业提供线上支持及服务。     

Remote sensing of soil salinity: potentials and constraints

Soil salinity caused by natural or human-induced processes is a major environmental hazard. The global extent of primary salt-affected soils is about 955 M ha, while secondary salinization affects some 77 M ha, with 58% of these in irrigated areas. Nearly 20% of all irrigated land is salt-affected, and this proportion tends to increase in spite of considerable efforts dedicated to land reclamation. This requires careful monitoring of the soil salinity status and variation to curb degradation trends, and secure sustainable land use and management. Multitemporal optical and microwave remote sensing can significantly contribute to detecting temporal changes of salt-related surface features. Airborne geophysics and ground-based electromagnetic induction meters, combined with ground data, have shown potential for mapping depth of salinity occurrence. This paper reviews various sensors (e.g. aerial photographs, satellite- and airborne multispectral sensors, microwave sensors, video imagery, airborne geophysics, hyperspectral sensors, and electromagnetic induction meters) and approaches used for remote identification and mapping of salt-affected areas. Constraints on the use of remote sensing data for mapping salt-affected areas are shown related to the spectral behaviour of salt types, spatial distribution of salts on the terrain surface, temporal changes on salinity, interference of vegetation, and spectral confusions with other terrain surfaces.As raw remote sensing data need substantial transformation for proper feature recognition and mapping, techniques such as spectral unmixing, maximum likelihood classification, fuzzy classification, band ratioing, principal components analysis, and correlation equations are discussed. Lastly, the paper presents modelling of temporal and spatial changes of salinity using combined approaches that incorporate different data fusion and data integration techniques.     

An LMI approach to robust reduced-order H ∞ filter design for polytopic uncertain systems

This paper proposes a method for robust reduced-order H _∞ filter design for polytopic uncertain systems, using linear matrix inequalities (LMIs). Sufficient LMI conditions for both robust full- and reduced-order H _∞ filter design are derived. Convex optimization problems are formulated and solved to obtain optimal H _∞ filters by using the resulting LMI conditions. The resulting conditions do not involve any non-convex rank constraints, and thus the proposed method for H _∞ filter design guarantees global optimum solutions. Numerical examples are presented to show the effectiveness of the proposed method. Recommended by Editorial Board member Huanshui Zhang under the direction of Editor Young Il Lee. This work was supported by the Brain Korea 21 Project and the Basic Research Program of the Korea Science and Engineering Foundation under grant R01-2006-000-11373-0. Hyoun-Chul Choi received the B.S., M.S., and Ph.D. degrees in Control and Instrumentation Engineering from Ajou University, Suwon, Korea, in 1995, 1997, and 2006, respectively. He was a Visiting Researcher at Griffith University, Brisbane, Australia, from 2001 to 2002, and a Postdoctoral researcher at Ajou University, Suwon, Korea, from 2006 to 2007. Since 2008, he has been with ASRI, School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Korea, where he is currently a Postdoctoral Researcher. His research interests include LMI-based control, optimal and robust control, network-based control, and mechatronics. Dongkyoung Chwa received the B.S. and M.S. degrees from the Department of Control and Instrumentation Engineering in 1995 and 1997, respectively, and the Ph.D. degree from the School of Electrical and Computer Engineering in 2001, all from Seoul National University, Seoul, Korea. From 2001 to 2003, he was a Postdoctoral Researcher with Seoul National University. In 2003, he was a Visiting Research Fellow at The University of New South Wales, Australian Defence Force Academy, and was the Honorary Visiting Academic at the University of Melbourne, Melbourne, Australia. In 2004, he was a BK21 Assistant Professor with Seoul National University. Since 2005, he has been an Assistant Professor with the Department of Electrical and Computer Engineering, Ajou University, Suwon, Korea. His research interests are nonlinear, robust, and adaptive control theories and their applications to the robotics, underactuated systems including wheeled mobile robots, underactuated ships, cranes, and guidance and control of flight systems. Suk-Kyo Hong received the B.S., M.S., and Ph.D. degrees in Electrical Engineering from Seoul National University, Seoul, Korea, in 1971, 1973, and 1981, respectively. His major graduate research works were centered on speed control of induction motors. He was an Exchange Professor at Rensselaer Polytechnic Institute, Troy, NY, from 1982 to 1983, and at the Institut National de Recherche en Informatique et en Automatique, France, from 1988 to 1989. He has been with the faculty of the Department of Electrical and Computer Engineering, Ajou University, Suwon, Korea, since 1976, and was a Visiting Professor at Griffith University, Australia, in 2001 and 2002. His current research interests include robust robot control, microprocessor applications, factory automation, and computer integrated manufacturing.