• 수산해양기술연구
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• 제39권1호
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• pp.77-83
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• 2003

Autonomous mobile robots based on the Web have been already used in public places such as museums. There are many kinds of problems to be solved because of the limitation of Web and the dynamically changing environment. We present a methodology for intelligent mobile robot that demonstrates a certain degree of autonomy in navigation applications. In this paper, we focus on a mobile robot navigator equipped with neuro-fuzzy controller which perceives the environment, make decisions, and take actions. The neuro-fuzzy controller equipped with collision avoidance behavior and target trace behavior enables the mobile robot to navigate in dynamic environment from the start location to goal location. Most telerobotics system workable on the Web have used standard Internet techniques such as HTTP, CGI and Scripting languages. However, for mobile robot navigations, these tools have significant limitations. In our study, C# and ASP.NET are used for both the client and the server side programs because of their interactivity and quick responsibility. Two kinds of simulations are performed to verify our proposed method. Our approach is verified through computer simulations of collision avoidance and target trace.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.295-299
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• 2005

본 연구는 개선된 거리변환 알고리즘을 사용하여 로봇이 이동해야 할 경로를 생성하고, 퍼지 시스템을 사용하여 경로추적 행위기와 장애물 회피 행위기를 구현해서 로봇이 그 경로를 안전하고 효율적으로 추적하는 것을 목적으로 하였다. 개선된 거리변환 알고리즘을 이용하여 로봇의 유연한 주행을 가능하게 했으며, 또한 주행거리와 주행시간도 단축되는 것을 확인할 수 있었다. 경로생성 후 경로를 추적할 때는 퍼지 시스템을 이용한 경로추적 행위기와 장애물 회피 행위기를 선택적으로 사용해서 경로추적 중에 예상치 못한 장애물이 발견되었을 경우에도 장애물을 회피한 후에 계속해서 경로를 추적하는 것을 확인함으로써 경로생성 후의 외부환경변화에도 강인함을 볼 수 있었다.

• 아동학회지
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• 제27권6호
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• pp.149-165
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• 2006

This study examined the relationships of parental behavior control recognized by children and its effect on children's emotional intelligence and conflict resolution strategies in their peer friendships. Subjects were 521 $5^{th}$, $6^{th}$ grade elementary school Children in seoul. Data were analyzed by Pearson's correlation, multiple regression and path analysis. Result showed that parents' control of children's behavior affected children's conflict resolution strategies in peer friendships and affected their emotional intelligence. Path analysis showed that control by parents, demand for maturity and clarity of communication directly affected compromising-integrating strategies. Parental control was affected directly by dominating strategies. Controlling behavior by demand of maturity, clarity of communication and nurture influenced compromising-integrating, avoidance and concession strategies of children's emotional intelligence.

• Journal of Korean Biological Nursing Science
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• 제21권3호
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• pp.217-223
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• 2019

Purpose: Caffeine is the most widely consumed psychostimulant of the methylxanthine class. Among adolescents, high-dose of caffeine consumption has increased rapidly over the last few decades due to the introduction of energy drinks. However, little is known about the time-dependent effect of high doses of caffeine consumption in adolescents. The present study aims to examine the short- and long-term influence of high-dose caffeine on behavior of adolescence. Methods: The animals were divided into three groups: a "vehicle" group, which was injected with 1 ml of phosphate-buffered saline for 14 days; a "Day 1" group, which was injected with caffeine (30 mg/kg), 2 h before the behavioral tests; and a "Day 14" group, which was infused with caffeine for 14 days. An open-field test, a Y-maze test, and a passive avoidance test were conducted to assess the rats'activity levels, anxiety, and cognitive function. Results: High-dose caffeine had similar effects in short-and long-term treatment groups. It increased the level of locomotor activity and anxiety-like behavior, as evidenced by the increase in the number of movements and incidences of rearing and grooming in the caffeine-treated groups. No significant differences were observed between the groups in the Y-maze test. However, in the passive avoidance test, the escape latency in the caffeine-treated group was decreased significantly, indicating impaired memory acquisition. Conclusion: These results indicate that high-dose caffeine in adolescents may increase locomotor activity and anxiety-like behavior and impair learning and memory, irrespective of the duration of administration. The findings will be valuable for both evidence-based education and clinical practice.

• 대한불안의학회지
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• 제19권2호
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• pp.77-82
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• 2023

본 연구는 COVID-19 대유행 이전부터 병원을 이용한 환자들의 관점에서 병원 회피와 연관 요인을 조사했다는 점에서 의미가 있다. 감염병 위기 기간 동안 병원 회피에 대응하기 위해서는 병원내 감염 관리 대책의 준비와 환자들과의 적극적인 소통이 필요하다. 이 연구는 향후 전염병 위기 기간 동안의 병원 회피에 대한 의료 정책을 포함한 대응책의 준비에 기여할 수 있을 것이다.

• 한국멀티미디어학회논문지
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• 제17권9호
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• pp.1104-1114
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• 2014

In large-scale crowd simulations, it is very important for the decision-making system of manipulating interactive behaviors to minimize the computational cost for controlling realistic behaviors such as collision avoidance. In this paper, we propose a large-scale realtime crowd simulation method using the affordance and navigation potential fields such as attractive and repulsive forces of electromagnetic fields. In particular, the model that we propose locally handles the realistic interactions between agents, and thus radically reduces the cost of expensive computation on interactions which has been the most problematic in crowd simulation. Our method is widely applicable to the expression and analysis of various crowd behaviors that are needed in behavior control in computer games, crowd scenes in movies, emergent behaviors of evacuation, etc.

• 대한본초학회지
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• 제22권2호
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• pp.137-146
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• 2007

Objectives : Investigation of the anitstress effects of Lycii Radicis Cortex. Methods : Behavior was measured in PAT and FST after applying stress to rats. Also, TH expression-degree in the regions of VTA and LC was measured, respectively. Results : The memory was improved in the LH 50mg/kg treated group in the passive avoidance test(P<0.01). The duration of immobility in the forced swimming test was significantly decreased in the LR 50mg/kg and 400mg/kg treated groups(P<0.0l). Stress-induced TH increases were meaningfully suppressed in the LR 100mg/kg and 400mg/kg treated group(P<0.001). Conclusion : Lycii Radicis Cortes has the effect of memory improving and antidepressant.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.319-322
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• 1995

This paper addresses that through the use of Fuzzy Logic Control, a reactiv behavior (e.g. avoiding obstacles on the way) are smoothly blended into one sequence of control action. In this classical problem, the aim is to guide a mobile robot along its path to avoid any static obstacles in front of it. This controller presented here uses three sub-controllers. This fuzzy controller was apply to a miniature mobile robot. This robot follows a left wall, maintining a minimum distance.

• International Journal of Aeronautical and Space Sciences
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• 제12권1호
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• pp.16-23
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• 2011

In this paper, nonlinear model predictive control (NMPC) is addressed to develop formation guidance for multiple unmanned aerial vehicles. An NMPC algorithm predicts the behavior of a system over a receding time horizon, and the NMPC generates the optimal control commands for the horizon. The first input command is, then, applied to the system and this procedure repeats at each time step. The input constraint and state constraint for formation flight and inter-collision avoidance are considered in the proposed NMPC framework. The performance of NMPC for formation guidance critically degrades when there exists a communication failure. In order to address this problem, the modified optimal guidance law using only line-of-sight, relative distance, and own motion information is presented. If this information can be measured or estimated, the proposed formation guidance is sustainable with the communication failure. The performance of this approach is validated by numerical simulations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.164.1-164
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• 2001

Q-learning is a recent reinforcement learning algorithm that does not need a modeling of environment and it is a suitable approach to learn behaviors for autonomous agents. But when it is applied to multi-agent learning with many I/O states, it is usually too complex and slow. To overcome this problem in the multi-agent learning system, we propose the successive Q-learning algorithm. Successive Q-learning algorithm divides state-action pairs, which agents can have, into several Q-functions, so it can reduce complexity and calculation amounts. This algorithm is suitable for multi-agent learning in a dynamically changing environment. The proposed successive Q-learning algorithm is applied to the prey-predator problem with the one-prey and two-predators, and its effectiveness is verified from the efficient avoidance ability of the prey agent.