• 제어로봇시스템학회논문지
• /
• 제17권8호
• /
• pp.843-850
• /
• 2011

In this paper, an effective path generation algorithm for obstacle avoidance producing small amount of steering action as possible is proposed. The proposed path generation algorithm can reduce unnecessary steering because of the small lateral changes in generated waypoints when UGV (Unmanned Ground Vehicle) encounters obstacles during its waypoint navigation. To verify this, the proposed algorithm and $A^*$ algorithm are analyzed through the simulation. The proposed algorithm shows good performance in terms of lateral changes in the generated waypoint, steering changes of the vehicle while driving and execution speed of the algorithm. Especially, due to the fast execution speed of the algorithm, the obstacles that encounter suddenly in front of the vehicle within short range can be avoided. This algorithm consider the waypoint navigation only. Therefore, in certain situations, the algorithm may generate the wrong path. In this case, a general path generation algorithm like $A^*$ is used instead. However, these special cases happen very rare during the vehicle waypoint navigation, so the proposed algorithm can be applied to most of the waypoint navigation for the unmanned ground vehicle.

• BMB Reports
• /
• 제50권1호
• /
• pp.31-36
• /
• 2017

High-dose caffeine uptake is a developmental stressor and causes food-avoidance behavior (aversion phenotype) in C. elegans, but its mode of action is largely unknown. In this study, we investigated the molecular basis of the caffeine-induced aversion behavior in C. elegans. We found that aversion phenotype induced by 30 mM caffeine was mediated by JNK/MAPK pathway, serotonergic and dopaminergic neuroendocrine signals. In this process, the dopaminergic signaling appears to be the major pathway because the reduced aversion behavior in cat-2 mutants and mutants of JNK/MAPK pathway genes was significantly recovered by pretreatment with dopamine. RNAi depletion of hsp-16.2, a cytosolic chaperone, and cyp-35A family reduced the aversion phenotype, which was further reduced in cat-2 mutants, suggesting that dopaminergic signal is indeed dominantly required for the caffeine-induced food aversion. Our findings suggest that aversion behavior is a defense mechanism for worms to survive under the high-dose caffeine conditions.

• Journal of Ginseng Research
• /
• 제18권3호
• /
• pp.165-174
• /
• 1994

To investigate the significant indicators Improving the undisturbed memory in animal behavior, we employed several behavioral methods (learning, relearning in radial maze, and active avoidance) with ginseng components. Results showed that the repeated intranasal administration of $Rb_1$ and total saponins from Korean red ginseng induced direct effects on the brain mechanisms in rats, and improved the spatial memory during the learning, relearning and retention in the 12-arm radial maze test. The intranasal treatment of the total saponins also effectively improved the disturbed memory (amnesia) by pentylentetrazole, and simultaneously protected the brain by decreasing the severity of motor epileptic seizures. The intraperitonial administration of polysaccharide fraction of Korean red ginseng could improve avoidance behavior (amount of the total ecapes) in the active-avoidance test. In addition, local changes of the temperature and resistance of skin observed after Rb, administration were suggested to reflect some action of sympathetic nerve Key words Memory, intranasal administration, pentylenetetrazole, Korea red ginseng.

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

• Natural Product Sciences
• /
• 제11권4호
• /
• pp.189-192
• /
• 2005

Anti-amnestic activities of Korean red ginseng (Ginseng Radix Rubra) and Crude drug-combined preparations (RGCDP-1, RGCDP-2, and RGCDP-3) were evaluated by the animal experiment. RGCDP-1 and RGCDP-2 were prepared based on Korean folk prescriptions, 'Chongmyongtang' and 'Guibitang', respectively, while RGCDP-3, by a combination of both. Among the three preparations, RGCDP-3 was found to show the most potent anti-amnestic activity as evaluated by the passive avoidance test with mice, indicating synergistic action by combined effect of RGCDP-1 and RGCDP-2.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.94-99
• /
• 1993

In this paper, the method for navigation and obstacle avoidance of an autonomous mobile robot is proposed. It is based on the fuzzy inference system which enables to deal with imprecise and uncertain information, and on the neural network which enables to learn input and output pattern data obtained from ultrasonic sensors. For autonomous navigation, the wall-following navigation utilizing input and output data by an expert's control action is constructed. An approach by the neural network is developed for the obstacle avoidance because of the redundant input data. For an autonomous navigation, the fuzzy control and the control of the neural network are integrated and its feasibility is demonstrated by means of experiment.

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

• 대한전기학회논문지:시스템및제어부문D
• /
• 제52권8호
• /
• pp.471-481
• /
• 2003

The acts of biological immune system are similar to the navigation for autonomous mobile robots under dynamically changing environments. In recent years, many researchers have studied navigation algorithms using artificial immune networks. Conventional artificial immune algorithms consist of an obstacle-avoidance behavior and a goal-reaching behavior. To select a proper action, the navigation algorithm should combine the obstacle-avoidance behavior with the goal-reaching behavior. In this paper, the neural network is employed to combine the behaviors. The neural network is trained with the surrounding information. the outputs of the neural network are proper combinational weights of the behaviors in real-time. Also, a velocity control algorithm is constructed with the artificial immune network. Through a simulation study and experimental results for a autonomous mobile robot, we have shown the validity of the proposed navigation algorithm.

• 한국심리학회지 : 문화 및 사회문제
• /
• 제24권1호
• /
• pp.49-62
• /
• 2018

본 연구는 일반 성인을 대상으로 고통 감내력이 주관적 안녕감에 미치는 영향을 검증하고, 고통 감내력과 주관적 안녕감의 관계에서 경험회피의 매개효과를 알아보고자 하였다. 이를 위해 2015년 10월 21일부터 24일까지 전국의 일반 성인 285명을 대상으로 온라인 설문조사를 실시하였다. 고통 감내력 부족 척도, 주관적 안녕감 척도, 수용 행동 질문지로 설문지를 구성하였고, 온라인 조사 전문업체에 의뢰하여 설문지를 배포 및 회수하였다. 수집한 자료는 구조방정식 모형을 통하여 분석하였다. 분석결과, 고통 감내력은 주관적 안녕감과 정적 상관을 보였고, 경험회피와는 부적 상관을 보였으며, 주관적 안녕감과 경험회피는 부적 상관을 나타냈다. 또한 고통 감내력과 주관적 안녕감의 관계에서 경험회피의 매개효과를 검증한 결과, 경험회피는 유의한 수준에서 고통 감내력과 주관적 안녕감의 관계를 부분 매개하는 것으로 나타났다. 마지막으로 간접효과의 검증을 위하여 편향수정 Bootstrapping을 실시한 결과, 고통 감내력이 경험회피를 거쳐 주관적 안녕감으로 가는 매개효과가 통계적으로 유의한 것으로 나타났다. 즉, 일반인의 고통 감내력이 주관적 안녕감에 직접적인 영향을 미치면서 동시에 경험회피를 통해 간접적으로도 영향을 미치는 것을 알 수 있다. 마지막으로 본 연구의 의의, 제한점 및 추후 연구를 위한 고려사항에 대해 논하였다.

• 한국유기농업학회지
• /
• 제5권2호
• /
• pp.13-36
• /
• 1997

This study aims to point out the basic strategy of agrotechnical and -political approaches toward successful settling for the environmental agriculture system in Korea. Although environmental agriculture & forestry strategy toward the 21st century and it's action program were released in 1996, some scientist from environmental agriculture and organic agriculture still argue on the errors of it's strategy and action program in terms of environmental sound functions. Especially it's strategy and action program of government did not focus the reduction of fertilizer and pesticide as the matters of weight and importance to reduction of fertilizer and pesticide as the matters of weight and importance to realize an environmental sound agriculture system. And korean organic agriculture gets a point in dispute, because 1) they do not practice of Basic Standard of IFOAM and FAO/WHO Codex draft, and 2) organic farming is defined quite differently from internationally recognized core aspects of organic agriculture. Organic farming, in Korea, is taken to mean the replacement of chemical fertilizer by organic manure and avoidance of agricultural chemicals. In the paper it is discussed the necessity, purpose, effect and consequence of basic standard for korean organic agriculture. The reformation of the certification system and t he direct payment system in environmental agriculture & forestry strategy toward the 21st century and it's action program by government, and on the need of the teaching program and curriculum in high education institution, the breeding program of resistant cultivars, the soil testing for optimum fertilization strategy, the nutrient management program, the declaration for 2020 environemntal agriculture are also discussed.