• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.2
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• pp.82-90
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• 2003

The work presented here is a design and an implementation of PID control system to regulate a supply duct outlet air temperature in PEM (Personal Environment Module). In PEM, the air is heated to the required temperature while it flows through the supply duct without any mixing chamber. This makes the control of air temperature in PEM difficult. A simulation is done first to understand the relationship between a temperature distribution in working area, flow rate and the outlet air temperature of PEM. Then a linear dynamic model of heating process in PEM is derived. P, PD and PID type control systems, to provide the rapid response without overshoot and saturation in heater command voltage, are designed using a linear model obtained. Experimentally obtained data shows that the control system satisfies the design criteria and works properly in controlling the supply duct outlet air temperature.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.26-30
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• 2014

Listeria monocytogenes continues to be a important food safety concern. The aims of the present study were to investigate the prevalence and antimicrobial susceptibility of L. monocytogenes. A total of 1,042 samples was collected from 2010 to 2011 in Seoul and twelve L. monocytogenes were isolated. Isolation rate was Gimbap (0.8%), Beef (yukhoe) (2.6%), Pork (cooked) (5.9%), Fish(cooked) (6.3%), and Salmon (11.1%), respectively. In this study, most of the isolates were susceptible to antibiotics. The most common resistance was cefotetan on 11 isolates, followed by cefotaxime on 7 isolates, cepefime on 6 isolates and tetracyclin on 3 isolates.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.03a
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• pp.263-272
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• 2004

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.548-551
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• 1997

Performance of force tracking impedance control of robot manipulators is degraded by the uncertainties in the robot and environment dynamic model. The purpose of this paper is to improve the controller robustness by applying neural network. Neural networks are designed to learn the uncertainties in robot and environment model for compensating the uncertainties. The proposed scheme is verified through the simulation of 20DOF robot manipulator.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.3
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• pp.311-321
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• 2007

Nowadays, concerns have much more growing regarding indoor air quality (IAQ) on the public transportation including railway vehicles. Last year Korea Ministry of Environment (ME) set new guideline for public transportation. In this study several factors were analyzed which may affect comfortableness of railway passenger cabin, and we monitored IAQ parameters (PM10, CO, $CO_2$, VOCs, temperature and humidity) to investigate the present pollution in passenger cabin. In general, the railway air quality was satisfactory. The PM10 and $CO_2$ level on all passenger cabin were below the new guideline level 1 for PM10 $(200{\mu}g/m^3)\;and\;CO_2(2,000ppm)$. Clustering method was carried out to classify the air polluting pattern of the cabin. As a result, the pollutants could be classified to 4 clusters and the origin of pollution is soil, diesel exhaust gas, abrasion of rail and plume.

• Journal of the Korean housing association
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• v.14 no.3
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• pp.1-8
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• 2003

It is not sufficient to control the indoor thermal environment using only one or two parameters by itself as human response for the control of indoor thermal environment. So a proper environmental thermal index is required for the control of indoor thermal environment effectively. In this study, the physical environment was measured and analysed and the skin temperature of the subjects and their response were investigated to evaluate the optimum thermal comfort range for cooling season in an apartment house. As a result, the optimal temperature was 26.1$^{\circ}C$ and the temperature ranges which more than 80% responded as satisfactory were 24.1~28.$0^{\circ}C$, respectively. As the OT had most significant interrelation with the PMV, it is desirable to use the OT in evaluating the thermal environment during cooling. Also, the comfort range was concluded between OT 25.5~27.3$^{\circ}C$ by appointing the PMV of -0.5~0.5 as the optimum comfort condition. In addition, the Human responses were compared with calculated PMV, OT and MRT and the relationships are suggested in order to utilize to control indoor thermal environment.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.786-795
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• 2000

In this paper, a new impedance force control method for deburring and polishing process is proposed. The proposed method is robust to deal with unknown environment stiffness as unknown well as environment location. An adaptive technique is used to minimize the force error occurred due to unknown environment surface profile. A robust position control algorithm based on time-delayed information is used to cancel out uncertainties in robot dynamics. A three link robot manipulator is used to demonstrate performances of the proposed control on deburring and polishing tasks. Stability analysis for the adaptive control is presented and its results are confirmed by simulations.

• Journal of Forest and Environmental Science
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• v.12 no.1
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• pp.13-25
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• 1996

In recent erosion control works, securing not only the disaster prevention space but the environmental space, harmonized with surrounding environment and abundant with biological resources, are emphasized. Inspired of by the fact that efforts to secure such spaces have been being briskly promoted in Japan since the beginning of 1990s', we compile and analyze the Japanese sources about the "environmentally-sound erosion control works" to contribute to the erosion control works of our country. Specifically, in this report, we deal with the subjects of "establishment of the comfortable river environment" and "environmentally-sound erosion control works" which includes "erosion control dam", "water channel works and revetments", "fish routes" and "water quality conservation works".

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.7
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• pp.366-374
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• 2005

The purpose of this study is to find out main factors affecting public enterprise's environment , which improves the performance of public enterprise. In detail, under the premises of keeping publicity in Korea Electricity Industry, the main target of this study is to seek after factors enhancing entrepreneurship and deals with publicity which is related with entrepreneurship. Questionnaires are distributed to the employee of public enterprise, public servants, and civil corps. A total of 553 copies are collected. The main contents of questionnaires are related with the effect of publicity and entrepreneurship by government control, competitive environment and shareholding structure in Korea Electricity Power Corporation(KEPCO). The results of this survey are as follows : First government control is negatively related to the entrepreneurship while it is positively related to the Publicity. Second, this suey shows that competitive environment has a Positive influence on promoting both publicity and entrepreneurship. Third this survey in connection with shareholding structure indicates that present structure in KEPCO has a positive effect on publicity but negative effect on entrepreneurship. According to this empirical results, it is verified that the main issues on the performance of KEPCO ue related with the level of government control and competitive environment in its industry.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.181-190
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• 2019

In high school classrooms, it is reported that ventilation is often insufficient, increasing health risks among students. Therefore, indoor air quality in school classrooms is very important in terms of students' health and learning abilities. In this study, the effect of window opening, which is a control mechanism for air control in summer high school classrooms, on the change in air and indoor environment of the classroom was analyzed and physical conditions of indoor and air environment were observed during the classroom course, and satisfaction of the students and teachers was assessed with questionnaires. It was found that change rate of $CO_2$ concentration in classroom was effectively reduced by carrying out activity of opening the window by active environment control activity of occupants at break time, intermission time and cleaning time. And optimal window opening by students was presented to prevent unpleasantness and degradation of indoor air quality and the effects were analyzed.