• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.73-75
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• 2001

본 논문에서는 다중 스레드 Java 프로그램의 실행 중 처리되지 않는 예외상황을 실행 전에 미리 예측하는 분석 방법을 제안한다. Java에서는 안전성 문제 때문에 다중 스레드 사이에서 예외 상황을 발생시키지 않도록 제한하고 있는데 반해, 본 연구에서는 프로그래머가 자유롭게 다중 스레드 사이에 예외상황을 발생시킬 수 있도록 언어를 확장한 후에 그 프로그램에서 처리되지 않는 예외상황을 예측해낸다. 이 분석 방법은 다중 스레드 Java 프로그램의 각 스레드에서 동시에 수행될 수 있는 부분들을 미리 예측해내고, 이 분석 정보를 이용하여 다중 스레드 사이에서 예외상황을 발생시킬 때 처리되지 않는 예외상황을 예측한다.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.1-8
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• 2006

In ubiquitous environments, recommendation service based on multiple contexts is required. The total amount of information is larger due to the greater number of contexts in multiple context environments. This paper proposes a new effective recommendation method adaptive to multiple contexts in ubiquitous environments. A new method of recommendations in multiple context environments is suggested that uses user's preferences and behavior as a weighting factor. This paper describes the recommendation method, scenario and the experimental results. The results verify that the proposed method's recommendation performance is better than other existing method.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.101-107
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• 2009

Modern society encounters various accidents due to industrialization and numbers of studies are going on to minimize damage from accidents. For prevention of accidents, it is necessary to design a system that helps making accurate judgment in emergency cases and is able to instantly manage each contingency. Various studies are currently going on contingency information system under ubiquitous environment. However, there have not been sufficient studies on the system that is able to monitor and process multiple contingencies and thus we still have difficulties in coping with multiple contingencies promptly. This study designs a RFID/USN middleware system for multiple contingencies control that receives data from various kinds of sensors and saves data after time marking thus is able to provide conjectured context when requested.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.91-93
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• 2012

최근 모바일 컴퓨팅 환경 지원을 실현하기 위한 연구가 전 세계적으로 활발히 진행되고 있으며, 나아가 그 중요성은 점점 더 증가하고 있다. 모바일 컴퓨팅 환경에서 지능형 서비스를 제공하기 위해서는 상황 데이터를 수집하고 적절한 가공을 통해 상황정보로 변환시켜 해석, 추론 및 학습 과정을 거쳐 사용자의 상황에 맞는 적절한 서비스를 제공할 수 있어야 한다. 본 논문은 모바일 환경에서 단일 상황추론의 한계를 개선하는 다중 상황추론과 완전히 형성되지 않은 상황정보를 기반으로 한 상황추론으로 불확실성을 지원하는 다중추론지원 분산형 상황인식 시스템을 제안한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.581-587
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• 2011

A wireless sensor network needs to consist of multi-sensors in order to infer a high level of information on circumstances. Data fusion, in turn, is required to utilize the data collected from multi-sensors for the inference of information on circumstances. The current paper, based on Dempster-Shafter's evidence theory, proposes data fusion in a wireless sensor network with different weights assigned to different sensors. The frequency of events per sensor is the crucial element in calculating different weights of the data of circumstances that each sensor collects. Data fusion utilizing these different weights turns out to show remarkable difference in reliability, which makes it much easier to infer information on circumstances.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.3
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• pp.397-402
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• 2013

Time variation is the essential component of the context awareness. It is a beneficial way not only including time lapse but also clustering time interval for the context inference using the information from sensor mote. In this study, we proposed a novel way of clustering based multi-sensor data fusion for the context inference. In the time interval, we fused the sensed signal of each time slot, and fused again with the results of th first fusion. We could reach the enhanced context inference with assessing the segmented signal according to the time interval at the Dempster-Shafer evidence theory based multi-sensor data fusion.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.172-177
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• 2024

This paper presents a method to overcome the problem of increasing elevation estimation error when estimating elevation in a multipath situation with radar. A multipath situation means that radar reception signals reflected from the same target come from multiple paths. In non-multipath, the monopulse method is accurate. For the opposite case, the least square error method is accurate. In multipath situation and when the elevation angle is very low, a singular occurs where the least square error estimate diverges. This singular was identified based on the propagation factor, and monopulse and least square error estimation methods were selectively used. As a result, we succeeded in increasing the accuracy of elevation estimation. MATLAB simulations were performed to verify the method proposed in this paper.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.168-171
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• 2012

본 논문에서는 모바일 컴퓨팅 환경과 불확실성을 지원하는 다중추론지원 분산형 상황인식 시스템의 지식 베이스(KB: Knowledge Base)를 위한 모델로써 상황정보(OWL), 온톨로지 추론정보(OWL DL), 규칙 추론정보(SWRL), 베이지안 추론정보(PR-OWL)를 통합적으로 표현하는 UniOWL 통합상황모델을 제안한다. 제안한 통합상황모델은 상황정보와 다중 추론정보를 단일 구문, 즉 OWL 구문으로 표현하여 지식베이스 설계를 수월하게 하고 표현을 단순화하는 장점이 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.173-182
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• 2001

In this paper, we discuss how ontology Plays roles in building a distributed and heterogeneous knowledge-base system. First, we discuss relationship between ontology and agent in the Knowledgeable Community which is a framework of knowledge sharing and reuse based on a multi-agent architecture. Ontology is a minimum requirement for each agent to join the Knowledgeable Community. Second we explain mediation by ontology to show how ontology is used in the Knowledgeable Community. A special agent called mediation analyzes undirected messages and infer candidates of recipient agents by consulting ontology and relationship between ontology and agents. Third we model ontology as combination of aspects each of which can represent a way of conceptualization. Aspects are combined either as combination aspect which means integration of aspects or category aspect which means choice of aspects. Since ontology by aspect allows heterogeneous and multiple descriptions for phenomenon in the world, it is appropriate for heterogeneous knowledge-base systems. We also show translation of messages as a wave of interpreting multiple aspects. A translation agent can translate a message with some aspect to one with another aspect by analyzing dependency of aspects. Mediation and translation of messages are important to build agents easily and naturally because less knowledge on other agents is requested for each agent.

• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.19-24
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• 2012

In this paper, we propose the battery life time extension method in the multi-interface terminal by using the state information in an optical wireless integrated network architecture. When the bottlenecks occurs in the network, the terminal receives data packets via multipath. However, the battery life time is rapidly reduced because the power consumption of the terminal is bigger than single interface. For reducing the power consumption in the multi-interface terminal, the Optical Line Terminal (OLT) confirms whether the bottleneck phenomenon is occurred or not. And the network state information is transmitted to the terminal. The terminal turns one of the interfaces off to reduce the power consumption. In order to estimate the performance, we compare the power consumption between single and dual interfaces.