• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.423-428
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• 2013

This paper investigates a boundary tracking problem using multiple quadrotor UAVs to detect and track the boundary of physical events. We set the boundary estimation problem as a classification problem of the region in which the physical events occur, and employ SVL (Support Vector Learning). We also demonstrate a velocity vector field which is globally attractive to a desired closed path with circulation at the desired speed and a virtual phase for stabilizing the collective configuration of the multiple quadrotors. Experimental results with multiple quadrotors show that this study provides good performance of the collective boundary tracking.

• Journal of the Korean Society of Costume
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• v.50 no.7
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• pp.5-14
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• 2000

Fashion leadership of middle- and high-school male student was measured. The subjects were divided into five subgroups including, fashion dual leaders(13.3%), innovators(10.3%), opinion leaders(7.6%), followers(52.3%), and laggards(16.3%), according to their innovativeness and opinion leadership. The findings were as follows : fashion dual leaders were very confident and fashion-conscious while other subgroups were very price-conscious and quality-aware. Among the fashion information sources included in the study' my own experience and opinion' was the most Important to all 5 subgroups. Generally the higher the fashion leadership was, the more actively utilized fashion information sources. The fashion magazine and commercials as information sources was not as important to the subjects as it was to college women. Apparel shopping behavior was also significantly different among subgroups. As a whole, the general characteristics, such as. the use of fashion information and the apparel shopping behavior, of opinion leaders and innovators were similar, but those of followers and laggards were very dissimilar.

• Journal of the Korean Home Economics Association
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• v.35 no.1
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• pp.291-306
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• 1997

The purposes of this study were 1) to identify the gender differences in the perception of sexuality in jeans fashion advertising 2) to identify the differences between fashion opinion leaders and followers in the preferences of advertisements and followers in the preferences of advertisements and intentions to buy the advertised jeans in highly and low sexual advertising. The data were collected via a questionnaire from 441 collesge students(female=225, male=216) living in Seoul. Korea, and analyzed by t-test. The results of this study were as follows: First there were significant differences between male and female in the perception of sexuality in jeans fashion advertising. Second to significant differences between fashion opinion leaders and followers in intentions to buy the advertised jeans of highly sexy advertisements were found in the data collected from male. But there were not significant differences between fashion opinion leaders and followers in preferences and intentions to buy the advertised jeans of highly sexy advertisements in female's data. Third there were significant differences between fashion opinion leaders and followers in the preference of low sexy advertisements in female's data. But there were not significant differences between fashion opinion leaders and followers in preferences and intentions to buy the advertised jeans of low sexy advertisements in male's data.

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.2
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• pp.55-67
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• 2006

20세기에 탄생한 동력비행기는 인간의 이동능력을 비약적으로 향상시켰다. 인류의 미개척지였던 항공분야의 발전은 지속적인 기술개발을 통해 더 빨리, 더 멀리, 더 높이 향하기 위해서 계속 나아가고 있다. 이러한와중에 최근에 괄목할 만한 성장을 이룬 컴퓨터와 소프트웨어 산업의 발전은 비행임무에 따라 위험성이 높거나, 사람이 하기 힘든 반복적이고 지루한 비행을 대신하기위한 로봇 비행체 즉, 무인항공기의 개발을 가능하게 하였다. 무인항공기의 탄생 초기에는 조종사의 희생을 줄이기 위해 군사 분야에서 주로 사용되었으나, 산림감시나 해안정찰, 기상관측, 재난관측, 조난자 수색 등 민수분야의 임무로 점차 활동영역이 넓혀지고 있다. 현재 무인항공기에 탑재된 인공지능의 수준은 안정된 비행이 가능하도록 하는 자동조종(autopilot)과 주어진 비행경로를 추종하기위한 항법유도(Navigation & Guidance)정도이며, 비행 중 발생하는 비상상황에 대처하기 위한 의사판단은 지상의 조종자에 의해 결정된다. 앞으로는 계획되지 않은 상황을 맞이했을 때 무인기 스스로 판단하여 경로를 변경하고, 동시에 여러 무인기들과 협력하여 임무를 수행함으로써 임무효율을 높이는 방향으로 인공지능의 수준이 향상될 것이다. 본 논문에서는 최근의 무인항공기 개발추세와 이들 무인기에 고려되고 있는 제어기에 대해 살펴보고, 향후 무인항공기에 적용될 자율비행 알고리듬과 제어기 시스템의 개발동향에 대해 고찰하였다.

• Journal of Sensor Science and Technology
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• v.20 no.3
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• pp.178-186
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• 2011

Line tracking is a well defined method of mobile robot navigation. It is simple in concept, technically easy to implement, and already employed in many industrial sites. Among several different line tracking methods, magnetic sensing is widely used in practice. In comparison, vision-based tracking is less popular due mainly to its sensitivity to surrounding conditions such as brightness and floor characteristics although vision is the most powerful robotic sensing capability. In this paper, a vision-based robust path line detection technique is proposed for the navigation of a mobile robot assuming uncontrollable surrounding conditions. The technique proposed has four processing steps; color space transformation, pixel-level line sensing, block-level line sensing, and robot navigation control. This technique effectively uses hue and saturation color values in the line sensing so to be insensitive to the brightness variation. Line finding in block-level makes not only the technique immune from the error of line pixel detection but also the robot control easy. The proposed technique was tested with a real mobile robot and proved its effectiveness.

• Journal of the Korean Home Economics Association
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• v.35 no.3
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• pp.63-75
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• 1997

The purposes of this study was to identify the differences between fashion opinion leaders and followers in the characteristics oriented New Young Generation and the types of fashion advertising involvement. The data were collected via a questionnaire from 431 college students(female=218 male=213) living in Seoul, Korea and analyzed by factor analysis and t-test. The results of this study were as follows: First, eight factors of the characteristics oriented New Young Generation were identified: Fashion, individuality, preference of caffe with affective mood, expression of emotion, indivisualism, preference of tastes oriented Western Europe, activity of pan club and chatting by personal computer. The significant differences between fashion opinion leaders and followers in fashion, individuality, preferences of the caffe with affetive mood, and expression of emotion were found in the data collected from female. There were significant differences between fashion opinion leaders and followers in fashion, individuality in the data collected from male. Second, three factors of fashion involvement advertising were identified: The hedonic involvement, social involvement, utilitarian involvement. The significant differences between fashion opinion leaders and followers in the hedonic involvement, social involvement, utilitarian involvement and the levels of involvement were found in the case of female's data. There were significant differences between fashion opinion leaders and followers in the hedonic involvement, social involvement and levels of involvement except for utilitarian involvement in the case of male's data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1628-1635
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• 2008

In this paper, the motion coordination algorithm of mobile agents in active sensor network is proposed to track the dynamic boundary for environmental monitoring. While most of dynamic boundary tracking algorithms in the literature were studied under the assumption that the boundary and/or its evolving rate is known a priori, the proposed algorithm is assumed that the individual active agent can measure the state of environment locally without any information of the boundary. When the boundary is evolving dynamically, the formation of active agents is designed to achieve two objectives. One is to track boundary layer based on the measured information and a small deviation. The other is to maintain a uniform distance between adjacent agents. The algorithm structure based on a state diagram is proposed to achieve these two objectives. Finally, it will be shown in the simulations that all given agents converge to a desired boundary layer and maintain a formation along the boundary. (e.g., a circle, an ellipse, a triangle and a rectangle)

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.157-162
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• 2008

The ship's maneuverability is the important factor to avoid ship's collisions. The ship's maneuverability is usually measured in a deep water, and the turning ability is decreased and the course stability is improved in a shallow water. The variation of the turning ability could cause the risk of collision. In this paper, we proposes application technique of Variable Safe-Guard Ring to consider the shallow water effect and to be simple to estimate the grade of collision risk simultaneously. Through the mathematical simulation, the availability of new method was varified. Therefore this method is expected enough to support a maneuver for collision avoidance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.501-507
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• 1999

At the mobile unit for adaptation the propagation environment, it is necessity to adapt very fast the weight coefficient vector of adaptive array antenna In this paper, for the BPSK and BFSK signals with S/I=2, S/N=10 subband adaptive array signal processing method to the linear array antenna using the LMS & the Kalman filter algorithm is proposed. For the 4 elements equidistance linear array antenna systems LMS and Kalman algorithms with subband adaptive instruction principles using the subband signal processing method are adopted and the computer simulation results to the constant amplitude envelope signals such as BPSK or BFSK can be seen that the convergence characteristics of directional patterns and the signal following characteristics are more fast and stable.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.359-366
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• 2022

In this study, the load fluctuation of the main engine is considered to be a disturbance for the jacket coolant temperature control system of the low-speed two-stroke main diesel engine on the ships. A nonlinear PID temperature control system with satisfactory disturbance rejection performance was designed by rapidly transmitting the load change value to the controller for following the reference set value. The feed-forwarded load fluctuation is considered the set points of the dual loop control system to be changed. Real-coded genetic algorithms were used as an optimization tool to tune the gains for the nonlinear PID controller. ITAE was used as an evaluation function for optimization. For the evaluation function, the engine jacket coolant outlet temperature was considered. As a result of simulating the proposed cascade nonlinear PID control system, it was confirmed that the disturbance caused by the load fluctuation was eliminated with satisfactory performance and that the changed set value was followed.