• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.74-84
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• 2008

To support advanced collaboration among knowledge workers distributed geographically, there have been extensive researches under the scope of ubiquitous computing environments. Especially, to cope with several known problems in traditional room-based collaboration environments such as uncomfortable sharing of visuals and documents and difficult operation of collaboration tools, several conceptual frameworks are designed and prototyped. Focusing on practical and interactive collaboration with remote nodes, in this paper, we conceptually design an agent-based service composition model for multi-party collaboration environments. The proposed model is designed to automatically discover and combine services to achieve given tasks in a collaboration environment by using high-level user commands (without the knowledge of internal architecture). Based on the service composition model, we develop a multi-agent-based management toolkit for multi-party collaboration environments. It provides easy-to-use GUI to operate various services in an environment and perform service composition algorithm to discover appropriate services and combine them. To explore the possibility of the toolkit we implement collaboration services to support video conference by using the toolkit.

• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.258-268
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• 2005

The efficient provision of multicast service to moving hosts in mobile computing environments is not so easy task. Bi-directional tunneling scheme causes overhead about encapsulation and triangular routing. On the other hand, remote subscription scheme need freDuent tree reconstruction, which is inefficient for rapid moving hosts. In this paper we propose Mobility Based Mobile Multicast(MBMOM) scheme which is based on host's mobility information. Ultimately MBMOM try to find the strong points of remote subscription scheme and hi-directional tunneling scheme. If host's mobility speed is considered to be high, multicast packets are forwarded using hi-directional tunneling scheme from home agent continuously. If host's mobility speed is considered to be slow, remote subscription scheme is applied for foreign agent and it try to join multicast tree. We developed analytical models to analyze the performance of proposed scheme and simulated our scheme compared with MOM(Mobile Multicast), RBMOM(Range Based MOM), and TBMOM(Timer Based MOM) schemes. Simulation results show that our scheme has shorter transmission delay than above 3 schemes in the aspect of host's mobility speed and multicast group size.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1575-1582
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• 1998

In this paper. we design and evaluate a cooperating model that increase problem solving ability by selecting proper cooperating partners under changing situation. In this model, to decide cooperation direction and extent, we have used a payoff function and then divided the group into two parts, cooperation part and non-cooperation part. To control these reconfigured groups at group level, group intention is used as a control media instead of existing data and goal. Group intention is abstractive and comprehensive and represents collection of strategies. Group intention is changed based on resources, information, and cooperation situation on group intention hierarchy. Two layered control is possible : first constraint with group intentions(group level) and then select a strategy under the constraint. These approaches are tested and evaluated on pursuit game testbed.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.18-23
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• 2001

멀티미디어 통신 등 서비스 광대역화를 위하여 PSTN, PCN 및 B-lSDN 등과 같은 기존의 망과 연동되게 될 IMT-2000 통신망은 기존의 통신망들이 서로 다른 하드웨어와 운영체제 등 상이한 플랫폼 환경 하에서 개발되어 있는 관계로 망관리 시스템을 구축하는 과정에서 통합 및 유지보수 상의 여러 문제점이 대두되게 된다. 이와 같은 문제점을 해결하기 위하여 본 논문에서는 I-Farmer 모델(Intelligent-Farmer Model)에 기반한 ITS(ISM-Node to SIB) 알고리즘을 제안한다. ITS 알고리즘은 I-Farmer 모델로 설계한 에이전트 시스템 중 Entity Node 및 ILB / OLB 컴포넌트를 AIN의 GFP(Global Functional Plane)내의 SIB 및 시스템 응용프로그램 생성 컴포넌트인 지능망 ASIB로 변형(transformation)해주는 알고리즘이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.111-122
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• 2008

Web service is defined to support interoperable machine to machine interaction over a network and defined as distributed technologies. Recently in web service environment, security has become one of the most critical issues. An attacker may expose user privacy and service information without authentication. Furthermore, the users of web services must temporarily delegate some or all of their behalf. This results in the exposure of user privacy information by agents. We propose a delegation model for providing safety of web service and user privacy in ubiquitous computing environments. In order to provide safety of web service and user privacy, XML-based encryption and a digital signature mechanism need to be efficiently integrated. In this paper, we propose web service management server based on XACML, in order to manage services and policies of web service providers. For this purpose, we extend SAML to declare delegation assertions transferred to web service providers by delegation among agents.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.171-173
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• 2005

커뮤니티 컴퓨팅은 유비쿼터스 컴퓨팅 환경을 기반으로 다양한 요구와 이를 수용하기 위한 서비스 혹은 개체를 나열하는 것 에서부터 이들 간 일시적으로 협력하고 주어진 상황을 효과적으로 인지할 뿐만 아니라 다수의 장치가 협력 관계를 추구하는 컴퓨팅 모델이다. 본 논문은 커뮤니티 모델과 미들웨어의 아키텍처를 확립하기 위한 요구사항과 구조에 대하여 논한다.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.1-17
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• 2007

A virtual enterprise (VE) can be mapped into a multi-agent system (MAS) that consists of various agents with specific role(s), communicating with each other to accomplish common goal(s). However, a MAS for enacting VE requires more advanced mechanism such as context that can guarantee autonomy and dynamism of VE members considering heterogeneity and complex structure of them. This paper is to suggest a context-based MAS as a platform for constructing and managing virtual enterprises. In the Context-based MAS a VE is a collection of Actor, Interaction (among Actors), Actor Context, and Interaction Context. It can raise the speed and correctness of decision-making and operation of VE enactment using context, i.e., information about the situation (e.g., goal, role, task, time, location, media) of Actors and Interactions, as well as simple data of their properties. The Context-based MAS for VE we proposed('VECoM') may consists of Context Ontology, Context Model, Context Analyzer, and Context Reasoner. The suggested approach and system is validated through an example where a VE tries to find a partner that could join co-development of new technology.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.9
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• pp.407-418
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• 2023

The Multi-Object Goal Visual Navigation(MultiOn) is a visual navigation task in which an agent must visit to multiple object goals in an unknown indoor environment in a given order. Existing models for the MultiOn task suffer from the limitation that they cannot utilize an integrated view of multimodal context because use only a unimodal context map. To overcome this limitation, in this paper, we propose a novel deep neural network-based agent model for MultiOn task. The proposed model, MCFMO, uses a multimodal context map, containing visual appearance features, semantic features of environmental objects, and goal object features. Moreover, the proposed model effectively fuses these three heterogeneous features into a global multimodal context map by using a point-wise convolutional neural network module. Lastly, the proposed model adopts an auxiliary task learning module to predict the observation status, goal direction and the goal distance, which can guide to learn the navigational policy efficiently. Conducting various quantitative and qualitative experiments using the Habitat-Matterport3D simulation environment and scene dataset, we demonstrate the superiority of the proposed model.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.118-120
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• 2006

커뮤니티 컴퓨팅 시스템은 3단계 모델(CCM, CIM-PI, CIM-PS)로 이루어져 있다. 모델은 이 전의 모델을 기반으로 툴의 지원을 받아 코드를 상세화하면서 실제 구현단계에 이르게 된다. 3가지 모델 중 가장 먼저 기술해야 하는 CCM(Community Computing Model)은 커뮤니티 컴퓨팅 시스템에 대한 가장 놓은 수준의 추상화 모델로서, 시스템의 환경과 요구사항을 기술하는 부분이다. 기술된 CCM을 기반으로 생성되는 CIM-PI(Platform Independent Community Implementation Model)에서는 시스템의 구현을 고려하여 컴퓨팅 요소들과 또 이들 간에 생길 수 있는 협업관계를 자세히 기술한다. 이렇게 기술된 CIM-PI를 멀티에이전트 플랫폼 위에서 작동할 수 있도록 CDTK를 이용해 변환해 농은 것이 CIM-PS(Platform Specific Community Implementation Model)이다. 본 논문에서는 커뮤니티 컴퓨팅 시스템 개발을 더욱 쉽고 체계적으로 개발하기 위해 만든 CDTK와 이 개발 툴을 통해 얻을 수 있을 수 있었던 여러 장점들에 대해 소개한다. CDTK를 이용한 적용사례로 유비쿼터스 환경내에서 발생할 수 있는 가상시나리오에 적용하여 CDTK의 실현성과 효율성을 검증해 보았다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1039-1042
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• 2003

최근 인터넷의 급속한 성장과 초고속 통신망의 구축으로 인하여 다양한 멀티미디언 서비스들이 제공되고 있다. 그러나 현재 대부분의 멀티미디어 서비스들은 클라이언트/서버 모델을 기반으로 구축되어 있기 때문에, 중앙 서버로의 과도한 부하가 집중되는 문제점을 가지고 있다. 본 논문에서는 수수 P2P 환경으로 구축된 멀티미디어 서비스 환경에서의 자원 검색 기법을 제안한다. 제안 기법은 고정 에이전트를 기반으로 자원 검색을 수행하여 기존의 순수 P2P 환경에서의 검색 기법으로 인한 문제점을 해결한다. 또한, 시나리오를 통하여 본 논문에서 제안하는 알고리즘의 구체적인 동작과정을 제시한다.