• Transactions of the Korean hydrogen and new energy society
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• v.32 no.4
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• pp.271-276
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• 2021

Although the development of electric vehicles or electric commercial vehicles is underway in Korea, most companies are seeking to enter the global market because it is difficult to expand their business only in the domestic market. In addition, it is recognized that the country has difficulties in responding to regulations or related procedures when entering overseas markets, and due to such difficulties, it is not possible to gain opportunities to enter the market and gain the technical advantage. Therefore, it is necessary to support individual companies to overcome the difficulties of promoting and exporting products by establishing a pre-cycle support environment for technology development so that development parts can be installed in small electric commercial vehicles. Therefore, this study tried to understand the necessity and factors of small electric commercial vehicles for major ASEAN countries, and as a result, most of them raised the urgency and necessity of joint research.In addition, human resource development, government support, and technical support were suggested as the necessary factors for the study.

• Animal Bioscience
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• v.36 no.2
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• pp.248-255
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• 2023

Objective: Stress factors such as high temperatures, overcrowding, and diurnal temperature range exert profound negative effects on weight gain and productivity of broiler chickens. The potential of gamma aminobutyric acid (GABA) as an excitatory neurotransmitter was evaluated under various stress conditions in this study. Methods: The experiment was conducted under four different environmental conditions: normal, high temperature, overcrowded, and in an overcrowded-diurnal temperature range. The experimental groups were divided into (-) control group without stress, (+) control group with stress, and G50 group (GABA 50 mg/kg) with stress. Weight gain, feed intake, and feed conversion ratio were measured, and stress reduction was evaluated through hematologic analysis. Results: The effects of GABA on broilers in four experimental treatments were evaluated. GABA treated responded to environmental stress and improved productivity in all the experimental treatments. The magnitude of stress observed was highest at high temperature, followed by the overcrowded environment, and was least for the overcrowded-diurnal temperature range. Conclusion: Various stress factors in livestock rearing environment can reduce productivity and increase disease incidence and mortality rate. To address these challenges, GABA, an inhibitory neurotransmitter, was shown to reduce stress caused due to various environmental conditions and improve productivity.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.241-246
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• 2004

This paper proposed trajectory tracking control of mobile robot. Trajectory tracking control scheme are real coding genetic-algorithm and back-propergation algorithm. Control scheme ability experience proposed simulation. Stable tracking control problem of mobile robots have been studied in recent years. These studios have guaranteed stability of controller, but the performance of transient state has not been guaranteed. In some situations, constant gain controller shows overshoots and oscillations. So we introduce better control scheme using Real coding Genetic Algorithm(RCGA) and neural network. Using RCGA, we can find proper gains in several situations and these gains are generalized by neural network. The generalization power of neural network will give proper gain in untrained situation. Performance of proposed controller will verify numerical simulations and the results show better performance than constant gain controller.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.3-6
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• 1999

The study was performed to evaluate the sense of equilibrium by means of rotary chair system in middle school girls with dance learning. Control of equilibrium, which is the most important function in dancing, is maintained by vestibular, visual, and proprioceptive inputs. Experimental groups were divided into trained group with dance (experimental group, 13~14 ys, n=15) and untrained group (control group, 13~14 ys, n=15). experimental group was trained by programmed dancing for 12 weeks, 45 min/day and 5 day/week. Gain of eye movement was measured for vestibulocular reflex (VOR), visual vestibular stimulation (VVOR), optokinetic stimulation(OKN), and visual fixation (VFX). The gain of eye movement at higher than 0.08 hz was significant decrease in experimental group, and VVOR showed the similar fashion to VOR. The gain in OKN and VFX was not significant difference between experimental and control groups. These results suggest that programmed training of dancing improves control of balance by adaptation of the vestibular function, and rotary chair system would be useful to evaluate the sense of equilibrium ability.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.90-95
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• 2015

This paper proposes the new adaptive gain control monitoring sensor for the marine IT system. The marine IT system sensors make it possible to conduct search missions, record climate changes, provide pollution control, study marine life, conduct survey missions, tactical surveillance, and predict natural disturbances in the ocean. In this paper, the adaptive gain control circuit which changes its parameters according to the ambient noise situation for obtaining the precise location information of marine IT system sensor is developed and analyzed. The performance characteristics for ensuring the precise location information of marine system sensor is presented and analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring of the marine system.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.449-451
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• 2008

This paper studies the instability between homopolar generator and constant power load with negative impedance characteristics, provides the design method of homopolar generator system which overcomes the instability. In case of magnitude and phase of impedance of source and load mismatch, control instability of source can occur. For the safety of phase of load impedance, the gain of P, I controller with sufficient phase margin is applied through analysis on the simulation model of generator system, and the gain limit of load impedance is ensured by limitation of the gain margin of generator system. The stability of power system can be increased by considering and analyzing the impedance of source and load.

• KDI Journal of Economic Policy
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• v.37 no.3
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• pp.31-53
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• 2015

According to the macroeconomic allocation efficiency measure, particularly based on the methodology of Hsieh and Klenow (2009), Korea's allocation efficiency in the manufacturing industry deteriorated in the 2000s compared to that in the 1990s. This study compares the potential TFP gain when resource allocation is removed, an indicator of allocation inefficiency according to Hsieh and Klenow (2009), and the productivity dispersion in the Korean manufacturing industry. It finds that the TFP gain may be better explained by TFP dispersions rather than proxies related to factors of distortion. The findings imply that we should investigate the sources of TFP dispersion rather than the sources of distortion to explain increases in the TFP gain (or TFP loss), which is considered as allocation inefficiency in the literature.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.917-922
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• 2004

As the tasks of robots become more diverse, some complicated tasks have come to require force and position hybrid control. A compliant device can be used to control force and position simultaneously by separating the twist of the robot's end effector from the twist of compliance and freedom by using stiffness mapping of the compliant device. The development of a fuzzy gain scheduling scheme of control for a robot with a compliant device is described in this paper. Fuzzy rules and reasoning are performed on-line to determine the gain of twists based on wrench error and twist error and twist of compliance and twist of freedom ratio. Simulation results demonstrate that better control performance can be achieved in comparison with constant gain control.

• Journal of Korean Medicine for Obesity Research
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• v.1 no.1
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• pp.63-75
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• 2001

Objectives : Many women associate one or more of their pregnancies with the development of adult obesity. This study was designed to determine influencing factors on postpartum weight retention and whether the breast-feeding was available to weight loss in puerperium. Methods : Articles from the literature on 'postpartum weight retention' were examined. Results : These articles show that different factors were related with postpartum weight retention. This study suggests that moderate weight gain during pregnancy is important to prevent postpartum maternal obesity. Especially weight gain from 20 weeks to 36 weeks of pregnancy is important. Falling in depression and anxiety during postpartum period should be avoided and social support is also needed. Delivery at the financially secure status is also recommended. Sufficient physical activity and exercise are needed to prevent from postpartum weight retention. Weight loss with dieting and exercise during lactation don't have a bad influence on the growth of infants.

• Design & Manufacturing
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• v.17 no.3
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• pp.41-47
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• 2023

This paper presents the development of a controller that can control the temperature of an heating system based on a thermoelectric module. Temperature controller using Peltier has various external factors such as external temperature, characteristics of an aluminum plate, installation location of temperature sensors, and combination method between the aluminum plate and heating element. Therefore, it is difficult to apply the simulation and simulation results of heating system using Peltier at control algorithm. In general, almost temperature controller is using PID algorithm that finds control gain value heuristically. In this paper, it is proposed mathematical model that explain correlate between the temperature of the heating system and input voltage. And then, optimal parameter of estimated thermal model of the aluminum plate are searched by using genetic algorithm. In addition, based on this estimated model, the optimal PID control gain are inferred using a genetic algorithm. All of the sequence are simulated and verified with proposed real system.