• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.337-342
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• 2009

This paper concerns delay-range-dependent robust stability and stabilization for time-delay nonliner system via T-S fuzzy model approach. The time delay is assumed to be a time-varying continuous function belonging to a given range. On the basis of a novel Lyapunov-Krasovskii functional, which includes the information of the range, delay-range-dependent stability criteria are established in terms of linear matrix inequality. It is shown that the new criteria can provide less conservative results than some existing ones. Moreover, the stability criteria are also used to design the stabilizing state-feedback controllers. Numerical examples are given to demonstrate the applicability of the proposed approach.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3185-3199
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• 2018

Middle- and old-aged driver's capability in recognition for driving scene elements was compared. Central and ambient stimuli were selected from natural driving scene and sensitivity, bias and reaction time were measured as dependent measures. The results are as follows. First, in general, older drivers showed lower sensitivity than middle-aged drivers. In particular, the older drivers' sensitivity was significantly lower for the ambient stimuli than central stimuli, whereas the middle-aged drivers showed no significant difference between the two types of stimuli. Second, the older drivers tended to show more lenient responses whereas the middle-aged drivers responded more conservatively. Third, the older drivers showed longer reaction time than the middle-aged drivers, in particular, in the responses of miss and correct rejection. This results suggested that the older drivers' retention for driving scene elements in their working memory may not be stable, which can be resulted in difficulties in rapid and accurate responses in a real life driving.

• Cross-Cultural Studies
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• v.46
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• pp.465-495
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• 2017

The purpose of this study is to verify whether the concept of time conveys meanings similar to nonverbal communicative elements in foreign language education. This study surveys cultural traits of time from the French cultural education perspective. Anthropologist Edward T. Hall points out that each cultural community has developed a different perception of time and experience, and that time conveys the meaningful message nonverbally similar to the nonverbal elements such as space, gesture, eye movement, and facial expression. I investigated the time experiences of a drinking party in France and in Korea, from a cultural relativistic point of view. The subject of a drinking party was chosen on the ground that a drinking party is highly related to most people's daily lives and it also indicates how they have a relationship with others. I sought a new direction in foreign language cultural education by analyzing how cultural differences between the two communities, especially the relationships between individuals and organisations, ways to separate leisure and labor, and the nonverbal elements, are presented in the two drinking parties.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.113-115
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• 1998

다중프로세서 환경에서 타스크들을 할당해주는 중앙 프로세서를 두고 Laxity를 기반으로 긴급타스크를 선택하여 스케쥴링을 수행한다. 중앙프로세서는 프로세서들의 슬랙시간과 각 프로세서의 Local큐에 대기하고 있는 비주기적 타스크의 총 수행시간 등의 상태정보를 수집 분석하여, 타스크의 실행시간에 가장 적합한 프로세서를 선xor하여 할당한다. 또한 타스크 특성에 따라 주기적 타스크와 비주기적 타스크로 나누고 주지적 타스크는 마감시간을 지키는 범위 내에서 최대한 수행시간을 연기 시켰다. 시뮬레이션 결과 Overload(마감시간을 지키지 못하는 타스크)수의 감소와 빠른 응답시간을 제공함을 알 수 있었다.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.831-834
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• 2000

본 논문은 주파수 전이신호와 시간 전이 신호에 대해서 고조파 잡음 여기 방법과 시간 분리 여기 방법을 적용한 2.4kbps 음성부호화 방법을 제안한다. 혼합 여기 부호화 방법은 주기 신호와 비 주기 신호를 효과적으로 표현하기 위해 하모닉 잡음 모델을 사용한다. 혼합신호에 대한 잡음 성분은 캡스트럴 분석 방법을 사용함으로써 추출되고, AR(Autoregressive Model) 모델에 의해 표현된다. 시간 전이구간 신호에서의 모호한 음성을 효과적으로 제거하기 위한 또 다른 방법이 제안된다. 제안된 시간 분리 방법은 시간 에너지 변화정도를 관찰함으로써 전이 시점을 감지하고 다른 시간 길이를 가지는 두 블록으로 분리하여 분석한다. 시간 분리 방법은 분석을 위한 비대칭 윈도우와 합성에서의 위상 합성 방법을 포함한다. 제안된 방법을 사용한 2.4kbps 음성부호화 방법은 주관적 음질 평가에서 전이구간에서의 지각적 음질의 향상을 보여주었으며, 원본 음성 스펙트럼과의 고조파 비 매칭에 의한 윙윙거리는 기계적인 잡음을 감소시킨다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.610-612
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• 2001

시간 제약 조건을 가진 타임드 페트리넷으로부터 최적화된 비동기식 제어회로를 생성하기 위해서는 시간 분석을 통하여 도달 가능한 상태만으로 구성된 축소 상태 그래프를 생성하는 작업이 매우 중요하다. 본 논문에서는 기존의 방법들이 적용 가능한 타임드 페트리넷의 범주에 제약을 가하거나 혹은 회로의 합성과는 직접적인 상관없이 시간 분석을 위하여 대규모의 시간 상태 그래프를 부가적으로 생성하는 문제를 해결하기 위하여 타임드 페트리넷으로부터 축소된 시간 상태 그래프를 직접적으로 생성하는 방법을 제안 한다 실험 결과는 제안된 방법이 모든 범주의 타임드 페트리넷으로부터 빠른 시간 내에 합성에 충분한 축소된 상태그래프를 생성함을 보여준다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.551-558
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• 2015

As more people use Wi-Fi and hotspot, unauthorized APs become one of big security problems in modern society. From the beginning of 2010, researchers study about unauthorized AP continually and contributed a lot of methods of detecting unauthorized AP that use wireless resources. Many researches about unauthorized AP detection use time-delay measurement (e.g., average or standard deviation) which is caused by additional wireless connection. In the most previous researches, however, the unauthorized APs consist of laptop and pulg-in Wi-Fi adaptor, and researchers did not concern about time-delay caused by software network sharing. In this paper, we show that existing unauthorized AP detection scheme that can not efficiently classify the high performance unauthorized AP.

• Food Science and Preservation
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• v.13 no.2
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• pp.252-258
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• 2006

To find the optimum extraction condition of dried omija, central composite experimental design having three independent variable (extraction temperature, extraction time and water ratio) with five levels was conducted for response surface analysis. The maximum of soluble solid was predicted to the extraction conditions of over 25 fold water ratio, $7{\sim}8hr$ and $75^{\circ}C$. Total acid, total phenol, reducing sugar and vitamin C were predicted to respectively 30 fold water ratio, 6 hr, $70^{\circ}C$, 30 fold water ratio, $6{\sim}7\;hrs,\;80^{\circ}C$ and 30 fold water ratio, $6{\sim}8\;hr,\;80^{\circ}C$, 25 fold water ratio, $5{\sim}6hr,\;80^{\circ}C$ extraction condition. Turbidity of extraction condition. Turbidity of extraction condition was 7 over 25 ford water ratio and over $60^{\circ}C$. From the superimposing results of response variables, the optimum extraction condition was predicted 25 folds water ratio, 6 hr and $65{\sim}70^{\circ}C$.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.2
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• pp.144-150
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• 2002

In this paper a design of neuro-fuzzy-based predictive controller for nonlinear systems with time-delay is proposed. The proposed control system contains two neuro-fuzzy systems called ANFIS(Adaptive Neuro-Fuzzy Inference System). One is run as a series-parallel mode and the other is run as a parallel mode. An ANFIS running in series-parallel mode emulates the response of the nonlinear system with time-delay. Another ANFIS running in parallel mode generates the predicted output of the nonlinear system to compensate for the time-delays. Therefore, the proposed control system can be thought of as an extension of Smith-predictor scheme to the nonlinear systems with time-delay. A detailed design Procedure is presented and finally computer simulations are executed for the effectiveness of the proposed control scheme.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.5
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• pp.87-97
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• 2013

This study tried to explore the quantitative travel heterogeneity between elderly and non elderly people, focusing on urban and rural areas in south Chungcheong province. For the analysis, a PLS(Partial least square) model is applied with economic and traffic environment characteristics of the urban and rural areas. The characteristics of elderly and non elderly people in the urban and rural areas are derived from the 2011 person trip survey. As a result, the study found out that the key factors affect on elderly people in the urban and rural areas are bus operation interval, number of bus operation routes, number of household member, and a monthly average income of household. In case of non elderly people, areas economic factors such as GRDP, the rate of economic activity, and employment status as well as those of elderly people. Meanwhile, female elderly people in rural area have more sensitivity compared to male elderly people and the gender heterogeneity is not revealed in non elderly people.