• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.2
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• pp.154-160
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• 2009

A control system composed of two fuzzy controllers is proposed to balance the pole as well as to move the cart to the center of the track of the cartpole system. The two fuzzy controllers are designed with 2 input variables respectively and their control characters are studied in order to devise a control scheme that alternates the two fuzzy controllers. It is found that the control system using the scheme works well even though there is some residual oscillations of the pole and the cart.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.270-278
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• 2007

In this study, we investigated the effects of grouping with respect to the level of students' agreeableness on 6th graders' science achievement, self-efficacy, and science learning motivation in cooperative learning. Three classes (72 students) from an elementary school were randomly assigned to a control group and treatment groups. An agreeableness test, self-efficacy test, and science learning motivation test were administered as pretests. The students of the treatment groups were grouped either homogeneously or heterogeneously on the basis of their agreeableness levels and were taught with a cooperative learning strategy, whereas the students of the control group were randomly grouped and were taught with a traditional method. The cooperative learning intervention lasted for 5 weeks (16 class periods). After the instructions, tests regarding achievement, self-efficacy, and science learning motivation were administered as posttests. The results indicated that the students of the homogeneous and/or the heterogeneous groups significantly outperformed those of the control group in the achievement test. However, students' achievement was not influenced by the grouping method on the basis of students' agreeableness. No significantly differences among the groups were found in the self-efficacy and science learning motivation.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.751-755
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• 1998

Among 2,373 slaughtered pigs examined for one year(March 1995 to February 1996), 1,899 pigs had visible pulmonary lesions. Prevalence rate of pulmonary lesion was examined by pathological techniques according to rearing and health managements of pig farms. The results were as follows : 1. Prevalence rate of pulmonary lesion in all-in/all-out flow farms(71.9%) was lower than that in continous flow farms(85.2%). 2. Prevalence rate of pulmonary lesion in non-infected farms with Aujeszky's disease virus and/or porcine reproductive and respiratory syndrome virus(74.4%) was lower than that in infected farms(85.5%). 3. During winter, prevalence rate of pulmonary lesion in farms with cold-control facilities(83.2%) was lower than that in farms with poor cold-control facilities.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.194-211
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• 2001

This study was conducted to investigate the effects of cooperative learning applying Jigsaw II on learner's self-regulated learning ability, achievements, self-esteem & cooperation. 12 graders were assigned to experimental group(applying Jigsaw II treatment) & control group(applying traditional instructional treatment). Experimental group was trained to ask comprehension & thought-provoking questions on the material when in tutor role & to explain material to group members when acting as tutee. Tutorial sessions followed over 8-week treatment. As a results, Experimental group outperformed control group on ability to construct learner's self-regulated learning ability, achievements, self-esteem & cooperation both during their tutorial interaction & on written measures.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.149.1-149
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• 2001

In multi robot environment, the action selection strategy is important for the cooperation and coordination of multi agents. However the overlap of actions selected individually by each robot makes the acquisition of cooperation behaviors less efficient. In addition to that, a complex and dynamic environment makes cooperation even more difficult. So in this paper, we propose a control algorithm which enables each robot to determine the action for the effective cooperation in multi-robot system. Here, we propose cooperative algorithm with reinforcement learning to determine the action selection In this paper, when the environment changes, each robot selects an appropriate behavior strategy intelligently. We employ ...

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.102-109
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• 1998

In this paper, we propose a method of cooperative control based on immune system in distributed autonomous robotic system(DARS). Immune system is living body's self-protection and self-maintenance system. Thus these features can be applied to decision making of optimal swarm behavior in dynamically changing environment.For the purpose of applying immune system to DARS, a robot is regarded as a B lymphocyte(B cell), each environmental condition as an antigen, and a behavior strategy as an antibody respectively. The executing process of proposed method is as follows. When the environmental codintion changes, a robot select an appropriate beharior stategy. And its behavior stategy is stimulated and suppressed by other robot using communiation. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and idotopic network hypothesis. And it is used for decision making of optimal swarm stragegy.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.273-283
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• 2008

This article describes a cooperative localization technique of multiple robots sharing position information of each robot. In case of conventional methods such as EKF, they need to linearization process. Consequently, they are not able to guarantee that their result is range containing true value. In this paper, we propose a method to merge the data of redundant sensors based on constraints propagation techniques on intervals. The proposed method has a merit guaranteeing true value. Especially, we apply the constraints propagation technique fusing wheel encoders, a gyro, and an inexpensive GPS receiver. In addition, we utilize the correlation between GPS data in common workspace to improve localization performance for multiple robots. Simulation results show that proposed method improve considerably localization performance of multiple robots.

• Journal of information and communication convergence engineering
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• v.4 no.1
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• pp.28-35
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• 2006

In this paper, we propose to synchronization method for mutual cooperative control method that have unstable limit cycles in a chaos trajectory surface in the chaotic UAVs. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. We also show computer simulation results of Arnold equation, Chua's equation trajectories with one or more Van der Pol as a obstacles. We proposed and verified the results of the method to make the embedding chaotic UAV to synchronization with the chaotic trajectory in any plane.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.357-358
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• 2019

본 논문에서는 조도센서와 마이크로웨이브센서 기반의 협력제어를 통하여 기존대비 35%P 전력절감이 가능한 에너지 절감형 스마트 LED 조명시스템에 대하여 기술하였다. 제안된 시스템은 센서모듈과 LED조명, 무선전송 모듈이 분리된 형태로 인지기반 조명 제어를 통하여 ESCO 사업에 적합한 에너지 절감형 융합 조명 시스템에 다양하게 활용될 수 있다.

• ETRI Journal
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• v.43 no.4
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• pp.758-768
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• 2021

In this work, the secrecy of a typical wireless cooperative dual-hop non-orthogonal multiple access (NOMA)-enabled decode-and-forward (DF) relay network is investigated with the impact of collaborative and non-collaborative eavesdropping. The system model consists of a source that broadcasts the multiplexed signal to two NOMA users via a DF relay, and information security against the eavesdropper nodes is provided by a helpful jammer. The performance metric is secrecy rate and ergodic secrecy capacity is approximated analytically. In addition, a differential evolution algorithm-based power allocation scheme is proposed to find the optimal power allocation factors for relay, jammer, and NOMA users by employing different jamming schemes. Furthermore, the secrecy rate analysis is validated at the NOMA users by adopting different jamming schemes such as without jamming (WJ) or conventional relaying, jamming (J), and with control jamming (CJ). Simulation results demonstrate the superiority of CJ over the J and WJ schemes. Finally, the proposed power allocation outperforms the fixed power allocation under all conditions considered in this work.