• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.60-63
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• 2018

This paper presents the FEM analysis results on the strength safety of a gas valve for a LPG cylinder. Based on the FEM analysis, the maximum von Mises stress on the boundary zone between a safety valve and the upper area of the thread is 99.2 MPa for the supplied gas pressure of 3.5 MPa in which the gas valve is fully opened. The maximum von Mises stress of 99.2 MPa is considered as safety value, because that value is lower than the yield stress of a brass material. In this case, the maximum deformation at the upper right part of the pressure regulator is 0.002mm. The maximum deformation zone is not a meaning part of the sealing part such as an O-ring or a diaphragm of a gas valve and a pressure regulator. The proposed hybrid gas valve model in which is integrated with a conventional cut-off valve and a pressure regulator is recommended as a gas leakage free mechanism and minimized compact size for a LPG cylinder.

• Journal of The Korean Association of Information Education
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• v.2 no.2
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• pp.201-208
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• 1998

Recently software complexity will continue to increase dramatically in the coming decades because of the dynamic and distributed nature of both data and applications. Not only must software systems assist in coordinating tasks among humans, they must also help mannage cooperation among distributed programs. Software agent may properly respond to these requirements. This paper investigates the adaptive characteristics found in adaptive tutoring agents. To funcion effectively throughout the range of situations presented by such a dynamic and extremely-distributed information entities, an agent must be highly adaptive. Adaptivity exists in several key aspects of agent's behavior to its dynamic situation. My goal is to show the various aspects of internal adaptivity that could be applied to build comprehensive agents that function effectively in tutoring agent system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.269-272
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• 2006

홈 엔터테인먼트 서비스는 홈 네트워크 서비스의 하나로서 홈 네트워크를 통해 제공되는 TV, 영화, 게임과 같은 다양한 디지털 콘텐츠를 TV라는 매체를 통해 PC와 같은 TV와는 다른 디바이스에 존재하는 다양한 콘텐츠를 손쉽게 즐길 수 있는 콘텐츠 서비스의 형태라고 할 수 있다. 이러한 다양한 기기에 존재하는 콘텐츠를 손쉽게 이용할 수 있는 허브 장치로서 STB(Set-top Box)가 대두되고 있다. STB가 허브 장치로서의 기능을 하기 위해서는 서로 다른 기기들과의 연계시 발생하는 여러 문제점들(예 : 조작의 불편)을 해결하고 이를 통합 조정할 수 있는 어플리케이션이 필요하다. 본 논문에서는 STB와 멀티미디어 기기 중의 하나인 HTPC(Home Theater PC)를 예를 들어 두 기기간의 연동 환경에서 STB 리모컨을 통해 HTPC를 제어할 수 있는 어플리케이션에 대해 연구한다. 이를 위해 이종 단말기 간의 연동을 위해 RMI(Remote Method Invocation)의 클라이언트/서버 통신 메커니즘을 응용하였다. 이를 통해 HTPC 뿐만이 아닌 다양한 디바이스를 STB에 연결하여 활용할 수 있는 좋은 예가 될 수 있을 것이다.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.500-506
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• 2006

An optical fiber displacement sensor has the advantages of relatively simplicity, cheap, small probe size and immunity against environmental perturbation. The working principle of the sensor is based on the intensity modulation that is detection light intensity reflecting from the surface being measured. This paper presents the mathematical model of displacement measurement mechanism of this sensor type. The theoretical and experimental data are compared to verify the model in describing the realistic approach to sensor design. Finally, the analysis results show that displacement response characteristics such as sensitivity, measuring range are easily modified by principal design parameters such as magnitude of optical Power, diameter of optical fiber core and distance between transmitting fiber and receiving fiber.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.275-283
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• 2006

Writers enroll their outcome to Program Deliberation & Mediation Committee and get the copyright preserved for the protection of IPR. The program registration is conducted through off-line and on-line methods, and especially on-line registration provides program registrants convenience along with the safety of property from external copyright invaders. However, it is a shortcoming that the integrity and confidentiality of the enrolled program cannot be guaranteed in case of internal factors such as system errors, administrator's illegal access and revision. This paper proposes the reliable system, ensuring programs and offering convenience of Digital signature management from the system errors and intruding factors by internal administrator, using the security of confidentiality, integrity and Multi-Signature Scheme for program.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.155-158
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• 2001

QoS(Quality of Service)측면에서 멀티미디어 응용 서비스를 제공하기 위해서 멀티미디어 통신은 여러 가지 요구사항을 지원하여야 한다. 연속적으로 생성된 미디어의 시간적인 관계를 유지하면서 재생시킬 수 있는 동기화 메커니즘은 무엇보다도 중요한 문제이다. 전달되는 매체를 공동으로 사용하기 때문에 트래픽의 폭주시, 지역적으로 멀리 떨어져 있는 경우에는 지연의 현상이 발생하게된다. 본 논문에서는 지연에 의해 발생되는 지연지터에 대하여 완충역할을 할 수 있는 최소 버퍼크기를 제시하였다. 주문형멀티미디어서버(MOS)의 경우 각 미디어 별로 서버에 저장하여 서비스하는 연구가 현재 활발히 진행되고 있으며 이것은 네트워크의 부하를 줄일 수 있다는 장점을 가지고 있다. 또한 이러한 데이터의 경우 클라이언트에서 어느 정도의 지터를 예상하여 버퍼의 크기를 갖고 있어야 하는 문제는 아직도 큰 문제점으로 나타나고 있다. 본 논문은 버퍼의 크기 및 재생에 관한 동기화 시점을 조정함으로서 버퍼의 오버플로우나 언더플로우의 현상을 방지하고자 한다. 제안한 기법은 기존의 기법보다 향상된 동기화 기법임을 시뮬레이션을 통해 검증하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.339-346
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• 2021

In this paper, we implemented an interface that provides a better food ordering mechanism and enables real-time selection of recipe ingredient ratios for customized food orders from global customers. Providing appropriate food to global customers by arranging a selection of menu on the order system screen that shows the basic ratio of each recipe ingredient and provides a customized recipe ingredient composition ratio by configuring a recipe graph without a system for simply selecting and ordering food menus. By enabling interaction, it allows users to provide customized services through the ratio adjustment of various recipe ingredients in the food menu ordering device

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.13-18
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• 2019

This paper proposes efficient and secure two-way authentication protocol for binding update messages between mobile devices and home agents / correspondent nodes in IoT and Mobile IPv6 (MIPv6) environments with limited computing power and resources. Based on the MIPv6 message exchange, the proposed protocol satisfies both the authentication and the public key exchange optimized for both sides of the communication with minimum modification. In the future, we will carry out a performance analysis study by implementing the proposed protocol in detail.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.619-622
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• 2009

P2P networks are undergoing rapid progress and inspiring numerous developments by gossip-based protocol. Gossip-based protocols for group communication have attractive scalability and reliability properties. We propose a self-organizing algorithm in the sense that the size of neighbor list achieved without any node knowing the group size. We also propose an efficient mechanism to reduce the redundancy of the system by backing up the nodes in the neighbor list. We present the design, theoretical analysis, and a detailed evaluation of the proposed algorithm and its refinements.

• Journal of Intelligence and Information Systems
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• v.8 no.1
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• pp.103-117
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• 2002

Recently, many researchers have developed applications for automated contract and negotiation using agent technologies on electronic commerce. Especially, they have tried to study negotiation mechanism applying agent instead of buyers and sellers. Traditional researches, however, often had limitations. In the researches of automated negotiation, the agents had to negotiate with the other agents for a simple negotiation issue because the mechanisms were naive. In the researches of negotiation by user interaction, the agents did not have supported the procedures and methodologies for making the automated negotiation but only supported the users by providing communication environment during the negotiation process by users. In this paper, we propose efficient negotiation model using the modified negotiation model of the game theory. In the proposed model, the agents negotiate automatically with the partner agent and make good benefits by the strategic method during the negotiation process. Each agent makes negotiation issues with user's requirements and exchanges its suggestion alternatively in each step of the negotiation process. The agent evaluates degree of satisfaction for the opposite's suggestion and uses it in the next step of suggestion. To find out the negotiation strategies of opposite side, the agent uses teaming by weights of issues. As a result, the agent improves each own benefits for the contract and reduces the unbalance of its benefits through the proposed negotiation mechanism. We implement the negotiating agents according to the proposed mechanism and prove the efficiency of the proposed model by various experimentation.