• 한국통신학회논문지
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• 제38C권9호
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• pp.775-780
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• 2013

Localization, or positioning, is gaining the increasing attention of researchers around the world. The location information, especially the indoor location, is important for navigation systems, heating and air conditioning systems, illumination adjustment, humidity control, robot service, and so on. In this paper, we propose a three-dimensional indoor localization technique using visible light. The main goal of our proposed scheme is to improve the accuracy of VLC-based indoor localization by utilizing multiple VLC transmitters. The simulation results validate the performance of our proposed scheme.

• 설비공학논문집
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• 제8권1호
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• pp.76-87
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• 1996

Energy analysis for the hot water heating control system of apartment house complex is accomplished by computer simulation. Mathematical model of a boiler, pipe network and a unit-house is developed. The effects of heating control methods on the heating performance and energy consumption of the system are investigated. The heating control methods considered in this study are a continuous heating control, and on-off heating control and an intermittent heating control methods. For each control method, the effects of an outdoor temperature, indoor temperature sensing position and the capacities of the boilers and circulating pumps on the heating performance and energy consumption are obtained and "the best" control method is recommended.commended.

• 설비공학논문집
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• 제13권10호
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• pp.947-959
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• 2001

We propose a control scheme to control the indoor zone temperature via variable air volume (VAV) unit. To control the room temperature, state space model of the conditioned zone which is partitioned into nine artificial sectional regions is derived. The nonlinearity of the damper motion and actuator are considered for the practical use in the state space system description. The temperature control of the room temperature is performed by manipulating the degree of openness of the damper in relation to the local room temperature and the supplied air flow rate. In general, since a local temperature in the conditioned zone is measured, it is required to estimate the temperature values in each regions for the precise temperature control. We thus design a state observer to estimate the regional temperature, and use these values in the controller. The overall control system consists of the state observer based state feedback with the integral control. We compared the control results of the proposed scheme with those of cascade proportional and integral (PI) control, and showed that the scheme achieved precise control of the conditioned system.

• 한국환경보건학회지
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• 제33권2호
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• pp.92-97
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• 2007

A series of source tests were conducted to characterize emissions of nitrogen oxide(NOx, NO, $NO_2$), carbon mon oxide(CO), carbon dioxide$(CO_2)$ and total VOCs from portable combustion devices in steady-state using well-mixed chamber. Since use of portable gas range is widespread in houses and restaurants in Korea, it is important to characterize the emission of air pollutants and suggest optimum ventilation rate. Ranges of emission rates of air pollutants from portable gas ranges were $NO \;0.551\sim0.939mg/hr,\;NO_2\;0.354\sim1.080mg/hr,\;NO_x\;1.207\sim1.631mg/hr,\;CO\;1.389\sim4.21mg/hr,\;CO_2\;2426.823\sim2973.495mg/hr$, and VOCs $0\sim0.119mg/h$. Mean of personal exposure and indoor environment level of $NO_2$ by combustion of portable gas range were 74.7 ppb and 65.4 ppb, respectively, suggesting persons using portable gas range in houses and restaurants might be highly exposed. Required ventilation rate to control the air pollutants emitted from portable gas range was maximumly $3.131m^3/hr$ on the basis of $NO_2$ indoor air quality standard.

• 한국철도학회논문집
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• 제11권4호
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• pp.378-383
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• 2008

환경부는 2006년 12월에 "대중교통수단 실내공기질 관리 가이드라인"을 제정하였다. 관리항목으로 이산화탄소($CO_2$)와 미세먼지(PM10)에 대해 각각 Level 1(평상시)과 Level 2(혼잡시)로 가이드라인을 제시하였다. 이에 열차와 전동차에 대해 실내공기질 관리가 필요하게 되었다. 본 연구는 2007년 9월과 11월에 4호선(당고개-오이도), 1호선 급행(동인천-용산) 전동차 운행구간을 대상으로 실내공기질을 측정하였다. 또한 전동차 설계검토 사양과 일반적인 공기인자 등의 물성값을 적용하여 $CO_2$ 농도를 예측하였다. 그리고 전동차 실내공기질 실측치와 비교분석 하였다. 측정결과 PM10 농도는 환경부 가이드라인에 각각 44, 57, 45% 수준, $CO_2$농도는 각각 39, 36, 44% 수준으로 양호하였다. 또한 $CO_2$ 농도 예측치와 실측치를 비교한 결과 예측치는 실측치에 유사한 결과로 나타났다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.731-736
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• 2008

There was in a building and with the technical advance for a energy saving the secret efficiency of the building improved together and continuously was come. The indoor air environment brought about the deterioration which is remarkable because of it. But time of most the indoor air environmental matter is one in the element which healthily affects biggest in the moderns who lives from the interior space. Today the plan for the air environmental maintenance which dwelling space is appropriate is demanded, is the actual condition where the method of the ventilation control which is energy saving and efficient is necessary. From the research which it sees, number of ventilation 0.7 time of the aeration which is a domestic legal baseline is excessive is judged from the research which sees, The sleep hour assumes it stays most long the hour when, number of ventilation 0 time 0.1 times 0.4 times $CO_2$ consistency measurements and analyzes number of ventilation conclusive escape. And $CO_2$ peak point control leads it decides a data, effective and it talks an energy saving circulation control method and it does to sleep.

• 설비공학논문집
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• 제27권10호
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• pp.537-543
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• 2015

Air-source heat pumps are widely used in winter as heating units due to their higher efficiency compared to electronic heaters or gas fired equipment. However, the air-source heat pump can cause discomfort during periodic defrosting operations. In this study, a PCM unit for continuous heating was adopted to solve this problem. The PCM unit consisted of a PCM, a heat exchanger, and control valves. It was installed between the outdoor and indoor units. The performance of the proposed system was measured during both defrosting and heating operations. The indoor unit showed an average leaving temperature of $26^{\circ}C$ after adopting the PCM unit for continuous heating during the defrosting operation.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.364-369
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• 2007

A system heat pump provides the benefits of comfort, energy conservation and easy maintenance. Recently, the system heat pump has been employed in small and medium-sized buildings. However, the performance data and control algorithm for system heat pump are limited in literature due to complicated system parameters and operating conditions. In the present study, the performance of a system heat pump with two indoor unit is measured by varying indoor loads, EEV opening, and compressor speed. In addition, the integral optimum regulator which includes MIMO control algorithm is proposed. The capacity modulation and optimum capacity for each indoor unit can be adjusted by utilizing the EEVs opening and compressor speed. The proposed scheme shows appropriate control performance at test conditions.

• 설비공학논문집
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• 제20권3호
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• pp.175-180
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• 2008

Flow quantity to supply to a coil in floor heating system is important to achieve comfortable indoor air condition in the winter season. The hot water header is used to distribute the water into the coil. Experimental study has been performed using the water header that have 5 branches consisted of flow control valves and automatic shut-off valves. Each branch line connected it with X-L pipe. Experimental tests accomplished it to investigate the flow distribution characteristics of the hot water header. Experimental results show that the selection of the pump head and differential pressure are very important to save running energy of the system, and high differential pressure needs more friction loss in the case of suitable differential pressure for balancing of the header.

• 설비공학논문집
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• 제25권12호
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• pp.685-692
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• 2013

In this study, the control characteristics and effects of heating control methods on the heating performance and energy consumption of a hot-water heating control system of a residential apartment were researched by simulation and experiment. The purpose of this study is to evaluate operational strategies for improving an indoor thermal environment and reducing f energy consumption in the radiant floor heating system of a residential apartment.