• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1569-1584
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• 2013

Ubiquitous interaction in a pervasive environment is the main attribute of smart spaces. Pervasive systems are weaving themselves in our daily life, making it possible to collect user information invisibly, in an unobtrusive manner by known and even unknown parties. Huge number of interactions between users and pervasive devices necessitate a comprehensive trust model which unifies different trust factors like context, recommendation, and history to calculate the trust level of each party precisely. Trusted computing enables effective solutions to verify the trustworthiness of computing platforms. In this paper, we elaborate Unified Trust Model (UTM) which calculates entity's trustworthiness based on history, recommendation, context and platform integrity measurement, and formally use these factors in trustworthiness calculation. We evaluate UTM behaviour by simulating in different scenario experiments using a Trust and Reputation Models Simulator for Wireless Sensor Networks. We show that UTM offers responsive behaviour and can be used effectively in the low interaction environments.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.251-257
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• 2010

This paper reports a noble instrument that helps physically disabled people to access computers. There have been numerous attempts to develop such a methodology, but most of them require an additional space for workstation often including access program installation. The additional space also needs to be carefully designed to consider each specific disabled area. This study aims to develop a system that removes the spacial limitation by putting the integrated computer interface using the wheelchair controller. The implementation of the computer workstation is performed by utilizing an USB interface. The developed equipment will take an important role to support various social lives for the users and eventually to improve their quality of life.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.71.1-75
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• 1998

NOD 데이터는 VOD 데이터에 비해서 life cycle이 짧다. 그리고 사용자의 접근성이 높으며, 접근패턴도 시간에 따라 달라질 수 있다. VOD 데이터와 같이 NOD 뉴스기사의 경우 특정 기사들에 집중적으로 접근된다. 그리고 이러한 인기 있는 기사들은 시간대에 따라 변할 수 있다. 본 논문에서는 이러한 인기도의 변화를 예측하기 위해서 시계열분석방법중의 하나인 지수평활법(exponenital smoothing method)을 사용한다. 시간대별 타임윈도우로 나누고 이전의 윈도우들의 접근패턴을 분석하여 다음 접근을 예측한다. 그리고 이 예측값을 이용해서 캐시정책을 새운다. 즉 예측값이 높은 기사순으로 캐시에 배치하는 것이다. 실시간 멀티미디어데이터의 경우 데이터의 방대함으로 연산의 오버헤드가 크다. 따라서 정적인 캐싱전략을 사용하는데, 하나의 윈도우동안 재배치하는 한번으로 한다는 것이다. 전통적인 block 단위 캐싱은 멀티미디어데이터에 적합하지 않다. 따라서 기사단위의 캐시구조를 제안한다. 사용자는 기사단위로 요청을 하기 때문에 재사용을 위해서는 기사단위로 캐시되야 한다.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.1002-1020
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• 2018

Virtual reality (VR) technologies, which have been improved of late, offer experiences closer to reality than before. While VR technologies are expected to be an effective medium if used in learning content that cannot be offered in real life, distraction factors in VR technologies may prevent the users' presence and flow, making these technologies ineffective. Therefore, this study, through experiment and observation, analyzed the effect of distraction factors on the user's experience perception and learning effect when using HMD-based immersive VR. Experimental results revealed that the distraction factors were shown to have a negative, albeit not generally significant (except for tactile interactivity), effect on vividness, tactile interactivity, locomotive interactivity, presence, and flow. Ultimately, they were shown to have a negative effect on learning.

• Journal of Korean Society of Rural Planning
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• v.3 no.1
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• pp.86-95
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• 1997

The purpose of this study is to develop the data structure for querying database of a rural house design. It is necessary, for developing the data structure, to define items of rural houses and to study about the processing of the data. The classifications of rural houses can be differed in the subjective opinion for computerization. In this study, items of classified rural houses can be expressed numerically, like size and number of room. The user who has insufficient knowledge about house is hard to input items fit personal taste. The querying algorithm was developed using the relationship of items and functions of house. Functions of house mean family life-style and how they use space.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.268-271
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• 2004

Today, the vehicle is used the mean of transportation as well as the mobile office with the third digital life space. So telematics is an emerging industry that has tremendous future potential. It is necessary the essential contents for telematics services : navigation map for navigation, POI, real-time traffic information etc. In this paper, we proposed the telematics contents server to manage the telematics contents with efficient performance in distributed environment. The telematics contents server transforms and stores the essential contents and provide it to user through standard interface. The telematics contents server is middleware to offer a rapid essential telematics contents management, client connectivity, and communications. It is useful for the telematics service provider to build telematics system under distributed environment.

• Korean Security Journal
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• no.7
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• pp.155-189
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• 2004

The mission of the police as described by law is to guard the life, body and property of all citizens. Such duties should be accurately performed based on legal and democratic procedures because the works of the police are directively influencing the overall lives of the citizens by restricting their freedom. We are frequently watching the traffic police on the street or road. Traffic policing aims to reduce crime and the opportunities for criminal activity in relation to the use of roads, that is to improve road user behavior in order to reduce accidents. The characteristics of traffic accident change is not similar in each traffic condition. The purpose of this study is to analysis a type characteristics of traffic accident change, such as number of deaths and wounded persons by the time, the vehicle, the type the road, the age group. Based on the characteristics of traffic accident change, traffic accident countermeasures are proposed, in which some variable of traffic policies such as traffic facilities, traffic regulation, and traffic safety education.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.335-339
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• 2001

City gas is one of the most important necessities of daily city life and social infrastructures. City gas is delivered to every user through a pipeline network. The gas pressure in the pipeline is regulated by gas regulator. In the pressure control system, characteristics of gas pipeline is as important as characteristics of regulator. There are many reports about the transfer function model of the fluid pipeline. But suitable model about the gas transmission pipeline is not known. In this paper, as the transfer function model of the gas pipeline, new model considering the heat transfer between pipe wall and gas and temperature change of gas is proposed. To evaluate this model, frequency response tests are used. As the result, the proposed model shows a better agreement when compared with the experimental result than conventional models. The results show the effectiveness of the model.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1169-1172
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• 2005

For elderly people, an advanced training machine that uses actuator and can adjust load according to muscle activity is proposed. The proposed machine allows users to have a safe and effective training through exercise close to ordinal motion appears in daily life such as stretching or stooping motion. A muscle activity sensor real-timely monitors the activation level of user's muscle during the exercise and the training load is adjusted based on the measured data. The training load is exerted and continuously controlled by electric/pneumatic actuator.

• The Journal of Information Systems
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• v.14 no.2
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• pp.133-154
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• 2005

The objective of this study is to find the factors influencing the use of mobile service. We extracted critical study variables according to literature reviews about adoption of information systems, those under the internet environment and mobile internet adoption for theoretical foundation. TAM suggested by Davis(1985) has explained the acceptance mechanism with the following constructs: perceived usefulness, perceived ease of use, attitude toward use, behavioral intention and actual usage. After studying prior literature reviews, this study investigated the group of people using mobile services. The result of study claims that it has same results with previous TAM, especially between personal innovativeness and attitude toward use have strong statistical relations. On the other hand, there haven't been any statistical relations between perceived ease of use and perceived usefulness and between perceived usefulness and behavioral intention, either. In conclusion, use of mobile service can be promoted by developing various kinds of mobile service, designing device and interface to use mobile service more convenience and familiar, stimulating user's innovative characters and recognizing mobile service more useful in real life.