• 디지털콘텐츠학회 논문지
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• 제9권4호
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• pp.607-616
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• 2008

컴퓨터 및 네트워크 기술의 발전에 힘입어 이전에는 불가능하던 컴퓨팅 패러다임이 현실화되고 있다. 이른바, 네트워크 컴퓨터로 지칭되는 컴퓨팅 방식에서 컴퓨터 시스템 및 리소스는 이전의 그것과는 비교할 수 없을 정도로 확장 가능하다. 네트워크에 접속되어 있는 여러 컴퓨터 시스템들의 무리는 하나의 거대한 가상 컴퓨터에 해당하며, 사용자는 네트워크 상에 분산된 방대한 리소스를 효율적으로 활용할 수 있다. 네트워크 상의 시스템에서 필요한 작업을 수행하고 리소스를 활용할 수 있기에 클라이언트를 경량화하는 것이 가능하다. 이러한 클라이언트는 씬-클라이언트로서 불리고 있는데 네트워크 상의 시스템과 리소스를 활용함으로써 필요한 작업을 수행한다는 점에서 네트워크 컴퓨터와도 일맥상통한다고 할 수 있다. 네트워크 컴퓨터 패러다임에서 네트워크는 애플리케이션 전달을 위한 기반 플랫폼으로서 작동하며 클라이언트 상에서 원격의 서버 시스템에 대한 접근 및 애플리케이션 실행하는 것을 가능하게 한다. 이를 구현하는 기술에는 여러 가지가 있지만 본 논문에서는 웹, X 윈도우, Pyjamas 기술을 활용할 것이다. 이를 통하여 사용자는 마치 로컬에서와 같이 서버 시스템의 애플리케이션을 활용할 수 있으며 보안 및 유지관리에 있어 효율을 극대화할 수 있다. 본 논문에서는 이러한 네트워크 컴퓨터 구현을 위한 기반 환경으로 웹 브라우저를 지정하였으며, 클라이언트에서 웹 브라우저를 통하여 서버 상의 애플리케이션을 효율적으로 활용할 수 있는 아키텍쳐를 설계하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.957-958
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• 2006

PC users could experience some inconvenience when they use their PC that was physically connected to network printers shared by other people in the network due to the overload. This paper shows how to resolve this kind of overload problem and established the embedded printer system based on embedded Linux system which performs the printer server in order for any users in the office to do printing work more smoothly via current network. It's own capabilities and functions were verified throughout the various tests in practical environment.

• 제어로봇시스템학회논문지
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• 제9권1호
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• pp.57-62
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• 2003

It is difficult to determine the feeding rate of coagulant in the water treatment plant, due to nonlinearity, multivariables and slow response characteristics etc. To deal with this difficulty, the genetic-fuzzy system genetic-equation system and the neural network system were used in determining the feeding rate of the coagulant. Fuzzy system and neural network system are excellently robust in multivariables and nonlinear problems. but fuzzy system is difficult to construct the fuzzy parameter such as the rule table and the membership function. Therefore we made the genetic-fuzzy system by the fusion of genetic algorithms and fuzzy system, and also made the feeding rate equation by genetic algorithms. To train fuzzy system, equation parameter and neural network system, the actual operation data of the water treatment plant was used. We determined optimized feeding rates of coagulant by the fuzzy system, the equation and the neural network and also compared them with the feeding rates of the actual operation data.

• 한국정보통신학회논문지
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• 제3권4호
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• pp.755-764
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• 1999

In this study, the system level network simulation is considered with adaptive array antenna in CDMA mobile communication system. A network simulation framework is implemented based on IS-95A/B system to consider dynamic handoff, system level network behavior, and deploying strategy into the overall CDMA mobile communication network under adaptive array algorithm. Its simulation model, such as vector channel model, adaptive beam forming antenna model, handoff model, and power control model, are described in detail with simulation block. In order to maximize SINR of received signal at antenna, maximin algorithm is particularly considered, and it is computed at each simulation snap shot with SINR based power control and handoff algorithm. Graphic user interface in this system level network simulator is also implemented to define the simulation environments and to represent simulation results on real mapping system. This paper also shows some features of simulation framework and simulation results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.897-900
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• 1998

Through fuzzy logic controller is very useful to many areas, it is difficult to build up the rule-base by experience and trial-error. So, effective self-tuning fuzzy controller for the position control of ball and beam is designed. In this paper, we developed the neural network control system with fuzzy-neuron which conducts the adjustment process for the parameters to satisfy have nonlinear property of the ball and beam system. The proposed algorithm is based on a fuzzy logic control system using a neural network learinign algorithm which is a back-propagation algorithm. This system learn membership functions with input variables. The purpose of the design is to control the position of the ball along the track by manipulating the angualr position of the serve. As a result, it is concluded that the neural network control system with fuzzy-neuron is more effective than the conventional fuzzy system.

• 한국시뮬레이션학회논문지
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• 제8권4호
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• pp.33-51
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• 1999

In this study, the system level network simulation is considered with adaptive array antenna in CDMA mobile communication system. A network simulation framework is implemented based on IS-95A/B system to consider dynamic handoff, system level network behavior, and deploying strategy into the overall CDMA mobile communication network under adaptive array algorithm. Its simulation model, such as vector channel model, adaptive beam forming antenna model, handoff model, and power control model, are described in detail with simulation block. In order to maximize SINR of received signal at antenna, Maximin algorithm is particularly considered, and it is computed at each simulation snap shot with SINR based power control and handoff algorithm. Graphic user interface in this system level network simulator is also implemented to define the simulation environments and to represent simulation results on real mapping system. This paper also shows some features of simulation framework and simulation results.

• 전기학회논문지
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• 제61권11호
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• pp.1676-1681
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• 2012

In network-based control system, measurement and control information is delivered by the network messages. Therefore, the performance of control system is directly affected by the performance of network system. System engineers need to evaluate the performance of network system to maintain the entire system in stable condition. BACnet is an international standard data communication protocol especially designed for building automation and control systems. In this study, experimental performance evaluation methodologies of BACnet MS/TP protocol and their practical evaluation results are presented.

• 한국산업융합학회 논문집
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• 제14권3호
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• pp.121-125
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• 2011

EMTP-RV is the very powerful program to analyze the dynamic operation of the power system. To use this package in the large complex power system, it is very important to simplify the power system to simple equivalent network. In our study the 100 MVA STATCOM is placed at 345kV "MIGUM" which is the one of the 345kV substations of the Korean Electric Power System that is consist of more than 1000-bus. MIGUM substation is connected with 7 separated transmission lines to main Korean Electric power system. We developed a new method to simplify the network except the substation that we want to analysis. The power system outside the 345kV substation is modeled into the equivalent network. The loop network outside the substation can be modeled to simplified Thevenin equivalent network. The proposed method is applied to IEEE-14 Reliability Test System and the results shows the effectiveness of the method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1594-1597
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• 2005

A rapid development and a wide use of the Internet have expanded a network environment. Further, the network environment has become more complex due to a simple and convenient network connection and various services of the Internet. However, the Internet has been constantly exposed to the danger of various network attacks such as a virus, a hacking, a system intrusion, a system manager authority acquisition, an intrusion cover-up and the like. As a result, a network security technology such as a virus vaccine, a firewall, an integrated security management, an intrusion detection system, and the like are required in order to handle the security problems of Internet. Accordingly, a router, which is a key component of the Internet, controls a data packet flow in a network and determines an optimal path thereof so as to reach an appropriate destination. An error of the router or an attack against the router can damage an entire network. This paper relates to a method for RSMS (router security management system) for secure networking based on a security policy. Security router provides functions of a packet filtering, an authentication, an access control, an intrusion analysis and an audit trail in a kernel region. Security policy has the definition of security function against a network intrusion.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.1018-1023
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• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.