• 한국정보과학회논문지:정보통신
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• 제35권5호
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• pp.384-394
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• 2008

무선 공유기란 NAT(Network Address Translation) 기능을 사용하여 여러 무선 사용자가 인터넷회선 하나를 공유할 수 있게 해주는 장치이다. 여러 개의 무선 공유기를 여러 사용자가 공유하여 사용하는 학교 또는 소규모 사무실 환경에서 사용자들은 무선 공유기들을 임의대로 선택하여 사용할 수 있어서 특정 무선 공유기에 사용자들이 몰리는 현상이 발생할 수 있다. 이러한 경우 무선공유기와 사용자들 사이에 부하 불균형의 문제가 발생한다. 그로 인하여 생기는 문제점 중 하나는 사용자가 몰리는 무선 공유기에 속하는 사용자들의 경우 서비스가 원활하지 않다는 점이다. 또 다른 문제점은 무선 공유기 전체 자원 이용률이 낮다는 점이다. 이 문제들을 해결하는 방법으로 본 논문에서는 Multiple SSID를 이용하여 무선 공유기의 대역폭 이용률을 극대화하는 부하 공유 기법을 제안한다. 제안된 기법에서는 주기적으로 각 무선 공유기들의 사용 가능한 대역폭 정보를 Multiple SSR를 이용하여 사용자에게 보여준다. 새로운 사용자는 최대 사용가능 한 대역폭을 가진 무선 공유기를 선택한다. 이 방법은 사용자와 라우터들사이에서 대역폭 활용관점에서 좋은 부하 분산을 가능하게 해준다. 제안한 방법을 ASUS WL 500G 무선 공유기를 이용하여 구현하였으며 실험을 수행하였다. 실험을 통해 제안된 방법이 기존 방법에 비해 대역폭 이용률이 향상되었음을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.718-723
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• 2005

In this paper, we propose the collaborative design system with which we can simultaneously modify the actual 3D CAD model by the remote control and have interaction on it. It enables instantaneous decision making among the multiple disciplines in distributed locations using the function of simultaneous access and video conference. It also provides the method of managing the consistency between design entities. This system consists of Collaborative Management Server, File Server, Solid Modeler Client, Remote Control Module and Client Module.

• 한국CDE학회논문집
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• 제5권1호
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• pp.12-22
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• 2000

Network and Internet technology opens up another domain for building future CAD/CAM environment. The environment will be global, network-centric, and spatially distributed. In this paper, we present an approach for network-centric feature-based modeling in a distributed design environment. The presented approach combines the current feature-based modeling technique with distributed computing and communication technology for supporting product modeling and collaborative design activities over the network. The approach is implemented in a client/server architecture, in which Web-enabled feature modeling clients, neutral feature model server, and other applications communicate with one another via a standard communication protocol. The paper discusses how the neutral feature model supports multiple views and maintains naming consistency between geometric entities of the server and clients. Moreover, it explains how to minimize the network delay between the server and client according to incremental feature modeling operations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1237-1252
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• 2010

This paper proposes an intelligent technique for data sharing and event transition among personal devices including smart phones, laptops, and desktops. We implemented the PES (Personal Event Service) system that proactively executes appropriate tasks across multiple devices without explicit user requests by sharing the data used by the user and recognizing user intention based on the observed actions of the user for specific devices. The client module of PES installed on each device monitors the user actions and recognizes the intention of the user. The server provides data sharing and maintenance for clients. The connection between client and server is established by Java RMI (Remote Method Invocation). A series of experiments were performed to evaluate user satisfaction and system accuracy, and the results showed that the PES system can proactively provide appropriate, personalized services with a high degree of satisfaction to the user in an effective and efficient manner.

• 로봇학회논문지
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• 제1권2호
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• pp.158-162
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• 2006

This paper presents a speaker recognition system intended for use in human-robot interaction. The proposed speaker recognition system can achieve significantly high performance in the Ubiquitous Robot Companion (URC) environment. The URC concept is a scenario in which a robot is connected to a server through a broadband connection allowing functions to be performed on the server side, thereby minimizing the stand-alone function significantly and reducing the robot client cost. Instead of giving a robot (client) on-board cognitive capabilities, the sensing and processing work are outsourced to a central computer (server) connected to the high-speed Internet, with only the moving capability provided by the robot. Our aim is to enhance human-robot interaction by increasing the performance of speaker recognition with multiple microphones on the robot side in adverse distant-talking environments. Our speaker recognizer provides the URC project with a basic interface for human-robot interaction.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.83-90
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• 2012

본 논문은 안드로이드 기반 스마트폰을 이용한 소규모 실시간 라디오 방송 시스템 설계 및 구현에 관한 연구이다. 서버-클라이언트 구조로 설계하였으며, 시스템을 간단히 하기 위하여 데이터 전송 방식으로 HTTP에 의한 점진적 다운로드 기법을 사용하였다. 실시간 방송을 실현하기 위하여 원음을 짧은 시간 간격으로 잘라서 캡쳐하여 압축/저장하였고, 이들을 순차적으로 클라이언트에서 재생하는 방법을 사용하였다. 이 방법은 서버에서 캡쳐 시 원음을 잃음과 클라이언트에서 재생 시 파일과 파일 사이 재생의 끊어지는 두 가지 문제를 발생 시킨다. 서버에서는 캡쳐 스레드와 압축/저장 스레드로 분리하고, 이중 버퍼링을 사용하여 해결하였으며, 클라이언트에서는 안드로이드에서 제공하는 미디어플레이어를 사용하고, 하나의 파일 큐에 다수의 음원 파일을 저장하여 해결하였다.

• 정보처리학회논문지B
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• 제12B권4호
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• pp.459-464
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• 2005

온라인 게임 시스템은 크게 서버와 클라이언트 두 부분으로 나누어 볼 수 있다. 클라이언트는 게임 서버와의 접속 그리고 서버로부터 전송되는 패킷 분석 등의 역할을 하며, 게임 서버는 사용자 정보와 데이터베이스 둥의 관리를 수행한다. 특히 게임 서버는 새로운 클라이언트가 게임을 수행하기 위해 서버로의 접속을 허용할 경우 기존에 연결된 사용자와의 온라인 연결을 유지하면서 새로운 클라이언트의 접속 요청을 받아들여 야 한다. 본 논문에서는 서버의 다중 작업 처리를 위한 방법 중 프로세스(Process) 방법과 쓰레드(Thread) 방법의 처리 형태를 비교한 후, 현재 대부분의 게임 서버에 적용되어 있는 비대칭 분산형 구조에 적합한 비대칭 분산형 다중 서버 구조를 제안하였다. 제안한 비대칭 분산형 다중 서버 구조는 서버의 기능을 로그인 서버, 게임 서버, 통신 서버, 데이터베이스 서버 형태로 세부적으로 분리하여 각각의 기능을 독립적으로 수행한다. 따라서 다른 구조들과 비교하였을 경우 경제적, 기능적으로 더 나은 성능을 보이며 특히 서버의 안정성과 확장성이 향상되었다.

• 수완나부미
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• 제3권1호
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• pp.25-46
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• 2011

The state-sangha relations in the countries of Theravada Buddhism has often been described as a mutually dependent patron-client relation in which the state and the sangha support each other by performing their due roles. Yet this theory involves a normative dimension that prescribes such a relation as the ideal in the Buddhist world. The explanatory power of this theory hence is hampered in a country where the ideal is not fully realized. In the wake of tumultuous political upheaval where political rivals vie for the state the ideal as well as the theory are put into a trial. The tragic history of modern Cambodia is a history of ceaseless conflict in which multiple contenders for the state had to define their relations with the sangha. The relations defined turned out less mutual than supposed. The state-sangha relations were rather unilaterally dependent. More often than not the sangha was subject to state control with no power to confront the state or coopted only to become a tool for political propaganda and manipulation. The sangha always played the role of client, waiting for the state to define the relation and to be benevolent. Even when the monks were forced to disrobe and when the sangha itself was annihilated, all they did was to wait for another patron state that would put the sangha back in place. The state-sangha relations the Cambodian history reveals were not close to one in which the two parties benefit each other on an equal basis. It was a patron-client relationship in which the client sangha had to be heavily dependent on the patron state. Such a unilaterally dependent relationship is the one that has prevailed in Cambodia.

• KEPCO Journal on Electric Power and Energy
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• 제7권2호
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• pp.277-283
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• 2021

Power plant simulators have been used for operator training, control verification and engineering verification. In general, simulators can be used in the place where they are installed by only single user group at a time. Considering high cost of simulator development, a lot of available scenarios, the diversity of user level and accessibility based on users' work location, development of simulator system that can be used by multiple user groups regardless of location is required in order to enhance utilization of simulators. In this paper, the simulator system that can be used by multiple user group simultaneously without location limitation is proposed. The simulator system is composed of simulator servers, database servers, HMI servers, a web server, web clients. Simulator server consists of control model, process model that are developed for Circulating Fluidized Bed power plant located overseas. A web server manages user accounts, operation procedures, multiple server access between web client group and simulator server group. In other words, a web server makes a user group select a simulator server at a time. The developed simulator system is integrated after implementing process model, control model, HMI, and web server. Web client systems are installed on local site where power plant is located, while simulator servers, HMI servers, database servers, and a web server are located in KEPCO RI. The developed simulator system is verified by steady-state test, malfunction test and so on via remote access.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.214-220
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• 2009

Recent advanced technologies enable multiple users to share the virtual environment and work together as they are collocated. Additional sensory information such as haptic could improve the cooperation. In this paper, we propose a server-client architecture with multi-rate haptic control to support a tangible cooperation. Using our approach, the system is able to maintain a consistent simulation state across multiple users as well as to provide a highfidelity stable haptic interaction. To verify our approach, we have developed an experimental application and tested the cooperation among multiple users. The results confirm that our system is able to provide coherency among clients as well as haptic transparency.