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        검색결과 8

        1.
        2001.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Epoxidized soy bean oil (ESBO) is a plasticizes of PVC which is being widely used as a gaskets for the lid of glass jars including baby food. Using reverse mutation assay, chromosome aberration test and micronucleus test, ESBO were evaluated the mutagenicity. In the reverse mutation test, ESBO did not induced mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA102 with and without metabolic activation. In the chromosome aberration test using CHL cells, the results showed no increased structural and numerical aberrations in the concentration of sample producing cytotoxicity with and without metabolic activation. The in vivo induction of micronuclei was measured in polychromatic erythrocytes of bone marrow of young (3 weeks old) and adult (6 weeks old) ddY mice of both sex. At 24 hours after treatment with ESBO 20, 10, 5, 2.5 g/B.W. kg/corn oil 10 ml by oral route animals were sacrificed and bone marrow cells were prepared for smear slides. The results showed no increased micronucleated polychromatic erythrocytes regardless of sex and age. It was concluded that water soluble ESBO did not show certain genotoxicity within our studies conducted.
        4,000원
        4.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        Security robot has gradually developed and deployed in order to protect civilian’s lives as well as fortune and subjugate the shortcomings of CCTV which lacks of mobility. We have developed a security robot for outdoor environment and the main purpose of the driving mechanism is to overcome the bumps or projections with high speed. The robot platform consists of 4 omnidirectional wheel-based driving mechanisms and suspension for each driving mechanism. In this paper, principal suspension parameters of outdoor security robot for overcoming obstacles with stability are studied and approximately optimized using Response Surface Methodology (RSM) since it is difficult to find the exact relationship between suspension parameters and the shock, which is significantly associated with stability of the robot, at the robot platform. Simulation using ADAMS is conducted for assessing the feasibility of optimized design parameters.
        5.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        In this paper, a hybrid semi-3D path planning algorithm combining Virtual Tangential Vector(VTV) and fuzzy control is proposed. 3D dynamic environmental factors are reflected to the 2D path planning model, VTV. As a result, the robot can control direction from 2D path planning algorithm VTV and speed as well depending on the fuzzy inputs such as the distance between the robot and obstacle, roughness and slope. Performances and feasibilities of the suggested method are demonstrated by using Matlab simulations. Simulation results show that fuzzy rules and obstacle avoidance methods are working properly toward virtual 3D environments. The proposed hybrid semi-3D path planning is expected to be well applicable to a real life environment, considering its simplicity and realistic nature of the dynamic factors included.
        6.
        2009.05 KCI 등재 서비스 종료(열람 제한)
        In this paper, a new driving mechanism of security robots which should overcome obstacles with stability even though moving in high speed is introduced. The driving mechanism has spring-based suspension and two wheels positively necessary to overcome obstacles. From the driving mechanism, it is mainly discussed how we can decrease overshoot and impulse occurred when the robot is in the process of overcoming obstacles. Finally, design parameters of the driving mechanism which guarantees stable motion while overcoming obstacles is deduced based on simulation results. Experiments are also followed to demonstrate how well the manufactured system works in its early stage of the practical use.
        7.
        2009.05 KCI 등재 서비스 종료(열람 제한)
        In this paper, we provide experimental results and verification for obstacle avoidance algorithm 'ELA(Emergency Level Around)', which is applicable to rescue robots. ELA is a low level intelligence-based obstacle avoidance algorithm, so can be used in fast mobile robots requiring high speed in operation with little computational load. Constructed system for experiments consist of laptop, sensors, peripheral devices and mobile robot platform VSTR(Variable Single-tracked Robot) to realize predetermined scenarios. Finally, experiment was conducted in indoor surroundings including miscellaneous things as well as dark environment to show fitness and robustness of ELA for rescue, and it is shown that VSTR navigates endowed area well with real-time obstacle avoidance based on ELA. Therefore, it is concluded that ELA can be a candidate algorithm to increase mobility of rescue robots in real situation.
        8.
        2008.08 KCI 등재 서비스 종료(열람 제한)
        We propose a novel real-time obstacle avoidance method for rescue robots. This method, named the ELA(Emergency Level Around), permits the detection of unknown obstacles and avoids collisions while simultaneously steering the mobile robot toward safe position. In the ELA, we consider two sensor modules, PSD(Position Sensitive Detector) infrared sensors taking charge of obstacle detection in short distance and LMS(Laser Measurement System) in long distance respectively. Hence if a robot recognizes an obstacle ahead by PSD infrared sensors first, and judges impossibility to overcome the obstacle based on driving mode decision process, the order of priority is transferred to LMS which collects data of radial distance centered on the robot to avoid the confronted obstacle. After gathering radial information, the ELA algorithm estimates emergency level around a robot and generates a polar histogram based on the emergency level to judge where the optimal free space is. Finally, steering angle is determined to guarantee rotation to randomly direction as well as robot width for safe avoidance. Simulation results from wandering in closed local area which includes various obstacles and different conditions demonstrate the power of the ELA.