• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.53-56
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• 2009

본 연구는 차세대 네트워크 환경에서 동적인 상황에 관련된 지식서비스를 제공하기 위해 서술논리와 SWRL 기반의 온톨로지 모델 프레임워크를 제공하여 추론과 상황 결정에 있어 온톨로지 기반의 지식베이스가 유용함을 제시한다. 기존 대부분의 온톨로지 모델은 단일 온톨로지나 정적인 온톨로지를 중심으로 모델링되었으나 본 연구에서 제시하는 온톨로지 모델은 서비스를 중심으로 동적인 상황에 능동적으로 대처할 수 있는 온톨로지 구조와 사용자를 중심으로 다양하게 변화하는 지식을 동적으로 처리할 수 있는 지식표현 패턴을 제안하여 공간과 시간에 따른 동적인 상황서비스가 적합함을 보여주었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1527-1530
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• 2009

유비쿼터스 환경의 확산에 따른 다양한 보안문제의 발생은 센서의 정보를 이용한 상황인식 보안 서비스의 필요성을 증대시키고 있다. 본 논문에서는 FCM (Fuzzy C-Means) 클러스터링과 다변량 퍼지 결정트리 (Multivariate Fuzzy Decision Tree)를 이용하여 센서의 정보를 분류함으로써 사용자의 상황을 인식하고, 사용자가 처한 상황에 따라 다양한 수준의 보안기술을 유연하게 적용할 수 있는 상황인식 보안 서비스를 제안한다. 제안 모델은 기존에 많이 연구되어 오던 고정된 규칙을 기반으로 하는 RBAC(Role-Based Access Control)계열의 모델보다 더욱 유연하고 적합한 결과를 보여주고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.131-134
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• 2011

상황인식은 사용자의 상황을 분석하고 이에 적합한 서비스를 자동으로 제공하는 컴퓨팅 기술이다. 상황인식에 관한 대부분의 기존 연구들은 개발자가 만든 서비스를 사용자에게 공급하는 전통적인 개발 모델을 따르고 있다. 이런 일방적인 모델은 원하는 서비스가 서로 다른 다양한 사용자들의 요구를 만족시키기 어려울 뿐만 아니라 상황인식서비스가 설치되는 각 지능공간의 특징을 반영하기도 어렵다. 사용자와 대상 컴퓨팅 환경을 고려하지 않고 서비스를 개발하고 배포하는 것은 어려운 일이다. 본 논문에서는 사용자가 자신의 지능공간을 구성하는 기기들의 기능을 활용해 직접 원하는 서비스를 개발 할 수 있도록 하는 새로운 상황인식서비스 개발 모델을 제안한다. 기존에도 이와 유사한 방법을 제안한 연구들이 몇몇 있었으나 기기의 일부 기능 간 연동만을 지원해 확장성이 낮았다. 본 연구는 독립된 다수 기기의 모든 기능을 사용자가 자유롭게 연동할 수 있게 한다는 점에서 이런 연구들 문제를 개선하였다. 본 논문에서는 지능공간을 위한 사용자주도형 상황인식서비스 개발을 지원하는 도비(Dobby) 시스템을 소개하고 이를 구현한 결과를 설명한다.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.738-742
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• 2008

The user model is an indispensable factor for providing users with personalized. services in the ubiquitous computing environment. In general user models, services which users prefer should be described in advance so that the system can recognize and interpret them automatically. Also, user's preferences as to the change of situation are not reflected in general user models due to their ignoring the situation. In this paper, we propose the self-growing user model which learns user experience and the system which automatically provides personalized community services through extracting user preferring services by situation.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.229-237
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• 2014

Today, the development and performance of a variety of smart phones is increasing with the number of smart phone users were. Advances in mobile networks and devices are spread smart phones. Smart home was increasing the interest. But until now, the study of user-centric services that the service was not implemented. Therefore, in this paper, the situation of the user, the user-centric service model that provides a smart home provisioning system OWL modeling is proposed.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.642-649
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• 2006

In order to recognize a situation from a environment which provides an intelligent service, we propose state-transition based situation modeling which is suitable for a low computing power and restricted resources like embedded systems, and we designed its application to a situation-action converter(SAC)which is consist of two parts; situation detector recognized wanted situations and action generator generated various control actions. Then, we implemented a situation manager for smart scheduler service by using a SAC which is installed to a ARM processor based embedded Linux evaluation board.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.2
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• pp.95-99
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• 2023

As our whole society has become increasingly aware of safety and emphasizes the importance of preventing safety accidents, the airline cabin service sector is also facing a strong demand to improve practical system for aviation safety education. In this regard, the development of appropriate safety education programs and the getting of human resources who can develop and operate such programs are becoming key issues. This study aims to provide academic and practical implications for safety education and training in airline cabins by reconfirming the importance and direction of safety education in the context of airline cabin services, and by specifying and establishing qualification requirements for personnel who develop and operate such safety programs. To this end, we review the content that should be included in safety training programs, the qualifications required of developers, managers, instructors, and examiners who develop or operate such programs, and how safety training programs can be continually improved as relevant conditions change in the future. In addition, we have also suggested ways to train appropriate managers, instructors, and examiners, including improving the compensation system for them, and how to effectively manage trainees. In order to secure a higher level of aviation safety in the future, it will be necessary to continue research on the development of more diverse and high-quality aviation safety education programs and the training of related personnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.125-132
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• 2017

Vehicular safety service reduces traffic accidents and traffic congestion by informing drivers in advance of threats that may occur while driving using vehicle-to-vehicle (V2V) communications in a wireless environment. For vehicle safety services, every vehicle must broadcasts a Basic Safety Message(BSM) periodically. In congested traffic areas, however, network congestion can easily happen, reduce the message delivery ratio, increase end-to-end delay and destabilize vehicular safety service system. In this paper, to solve the network congestion problem in vehicle safety communications, we approximate the relationship between channel busy ratio and the number of vehicles and use it to estimate the total network congestion. We propose a new context-aware transmit power control algorithm which controls the transmission power based on total network congestion. The performance of the proposed algorithm is evaluated using Qualnet, a network simulator. As a result, the estimation of total network congestion is accurately approximated except in specific scenarios, and the packet error rate in vehicle safety communication is reduced through transmit power control.

• Journal of The Korean Association For Science Education
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• v.19 no.2
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• pp.340-352
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• 1999

Constructivist theory and teaching science in the social context are a main stream in science education. This study was purposed to introduce the STS in-service program implementing in Chonnam National University. and to analyze the results of the program in terms of changes of teachers' and students' perceptions and attitudes. The major features of the STS in-service program were as follows: teacher-centered. teaching in the social context. emphasis on constructivist approach. development of STS module and implementations. A total of 20 secondary science teachers participated in the in-service program. and filled out two questionnaires. Science Education Reform Inventory and Constructivist Teachings Survey. Three of the 20 teachers were selected to gain information from their implementations of a STS module into their respective classrooms. The students completed two instruments. Constructivist Learning Environment Survey. and Scientific Attitude Survey. The responses from teachers and students are as follows: 1. The participating teachers were very aware of the necessity of reform in science education. and the degree of the perception of the necessity increased after the STS in-service program. 2. The STS program significantly improved constructivist teaching techniques. 3. The perceptions of the students about constructivist learning environments improved significantly after the STS in-service program. 4. Students' scientific attitudes improved significantly through STS approach. The STS in-service program with the above mentioned features was found to be effective in our current school system. and could be implemented successfully if teachers were willing to learn and participate in the reforms of science education.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.43-61
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• 2011

In this research, we propose a dynamic decision making using social context based on ontology. Dynamic adaptation is adopted for the high qualified decision making, which is defined as creation of proper information using contexts depending on decision maker's state of affairs in ubiquitous computing environment. Thereby, the context for the dynamic adaptation is classified as a static, dynamic and social context. Static context contains personal explicit information like demographic data. Dynamic context like weather or traffic information is provided by external information service provider. Finally, social context implies much more implicit knowledge such as social relationship than the other two-type context, but it is not easy to extract any implied tacit knowledge as well as generalized rules from the information. So, it was not easy for the social context to apply into dynamic adaptation. In this light, we tried the social context into the dynamic adaptation to generate context-appropriate personalized information. It is necessary to build modeling methodology to adopt dynamic adaptation using the context. The proposed context modeling used ontology and cases which are best to represent tacit and unstructured knowledge such as social context. Case-based reasoning and constraint satisfaction problem is applied into the dynamic decision making system for the dynamic adaption. Case-based reasoning is used case to represent the context including social, dynamic and static and to extract personalized knowledge from the personalized case-base. Constraint satisfaction problem is used when the selected case through the case-based reasoning needs dynamic adaptation, since it is usual to adapt the selected case because context can be changed timely according to environment status. The case-base reasoning adopts problem context for effective representation of static, dynamic and social context, which use a case structure with index and solution and problem ontology of decision maker. The case is stored in case-base as a repository of a decision maker's personal experience and knowledge. The constraint satisfaction problem use solution ontology which is extracted from collective intelligence which is generalized from solutions of decision makers. The solution ontology is retrieved to find proper solution depending on the decision maker's context when it is necessary. At the same time, dynamic adaptation is applied to adapt the selected case using solution ontology. The decision making process is comprised of following steps. First, whenever the system aware new context, the system converses the context into problem context ontology with case structure. Any context is defined by a case with a formal knowledge representation structure. Thereby, social context as implicit knowledge is also represented a formal form like a case. In addition, for the context modeling, ontology is also adopted. Second, we select a proper case as a decision making solution from decision maker's personal case-base. We convince that the selected case should be the best case depending on context related to decision maker's current status as well as decision maker's requirements. However, it is possible to change the environment and context around the decision maker and it is necessary to adapt the selected case. Third, if the selected case is not available or the decision maker doesn't satisfy according to the newly arrived context, then constraint satisfaction problem and solution ontology is applied to derive new solution for the decision maker. The constraint satisfaction problem uses to the previously selected case to adopt and solution ontology. The verification of the proposed methodology is processed by searching a meeting place according to the decision maker's requirements and context, the extracted solution shows the satisfaction depending on meeting purpose.