• 한국소음진동공학회논문집
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• 제17권3호
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• pp.226-234
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• 2007

This study aims to evaluate noise emission from water supply and drain installations in apartment bathroom. These noise were one of the most annoying noise sources in apartment houses. Especially, drain plumbing system have used bellow bathroom ceiling, it was very discomfort to hear the noise in bellow apartment. Noise of closets and faucets were measured which were main noise source, then these noise were evaluate and analyzed the emitting characteristics varying the supplying water pressure. As increasing the water pressure, also total noise level of the water supplying stool noise and faucet noise were increased. Especially the water closet showed remarkably the increasing noise level in middle and high frequency bandwidth, while the noise level of faucets increased in $50\;Hz{\sim}250\;Hz$ of low frequency bandwidth. Vortex closet were favorable to syphon closet, and lever faucet were favorable to conventional lavatory faucet on reducing the noise. Above these results could be used in basic data establishing KS (Korean Standard) for evaluation and rating procedure and measures reducing these noise.

• 한국농공학회논문집
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• 제51권5호
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• pp.101-106
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• 2009

The previous study developed the Filter-Disinfection-Adsorption (FDA) system to provide clean irrigation water for greenhouse cultivation as well as convenience water to farmers. In this study, the field examination was undertaken to assess performance of the FDA system. The field application was made in the suburb of Daegu, one of the large city in Korea. The study area located near by down-stream of Gum-Ho river is suffering low irrigation water quality problems with no water supply service facilities. Four water quality parameters including Suspended Solid (SS), Biological Oxygen Demand (BOD), coliform, and turbidity were selected to test the purification performance of FDA system. Also in order to improve the system, this study investigated the defects of using the FDA system through field monitoring. As results, it was found that this system can be used to supply good quality of irrigation water for greenhouse cultivation and also provide convenience water to farmers in the field areas of no water supply services.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.468-468
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• 1991

The variable-frequency type water supply equipment, which adopts the variable-voltage and variable-frequency converter(VVVF converter) to govern automatically the rotating speed of a pump, can save 15-20% of power, as compared with a throttle-controlled pump device or an airpressurized water supply equipment, and is finding a wide application. However, it still has some disadvantages : greater pressure fluctuations during switching over the pump and prolonged low-effeciency running of the pump in the case of small consumption of water. Therefore, it is difficult to apply the equipment to the fire water supply system where the water should not be put into use unless a fire takes place, and the water pressure in pipelines should permanently remain constant. This paper introduces the automatic regulation principle of the variable-frequency type air-pressurized water supply equipment (hereafter referred to as simply BFQS equipment) for dual purposes of daily life and fire control, which combined both technologies of speed governing by a converter and air-pressurized water supplying, then discusses some problems related to automatic control, and finally gives the experimental results of an embodiment-BPQS-100-50 water supply equipment.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 춘계학술대회
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• pp.5-8
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• 2004

Domestic city gas is supplying in an about 10 million household on present 34 city gas companies because is begun to supply regularly after two 1980 years middle. But, result that focus on city gas supply spread and stable supply for supply area and neglects about safety problem, hundreds casualties such as Ahyun explosion accident and Deagu city gas explosion accident were reached in situation that occurred large size calamity occurs it is dizzliness. In the case of advanced nation, can see that accomplish system and progress that in technology after experience major accident. Therefore, grasp problem investigating safety actual conditions for city gas institution and study about solvable plan is required this. Also, must guide reform and level elevation of a domestic company safety technology through induction and development of safety technology that is suitable in supply, domestic real condition etc. Must help in power positivity that is full text executing high-quality safety education about step High firing mechanism safety technology than present safety education.

• 상하수도학회지
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• 제38권2호
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• pp.69-81
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• 2024

In this study, an evaluation system that can be used to evaluate the feasibility of developing and supplying hydrothermal energy for the operation of large-scale complex facilities was developed. To this end, this study derived factors to be considered when selecting a location for the use of hydrothermal energy using raw water from multi-purpose dams and regional water supply systems through literature survey and expert interviews. The evaluation indicators derived from this study are divided into four sectors: hydrothermal energy utilization factors, location factors, planning factors, and disaster safety factors, and are composed of 10 mid-level indicators and 34 detailed planning indicators. The relative importance of all factors was derived using the Analytic Hierarchy Process (AHP) technique, and the developed evaluation indicators and relative importance were applied to four multi-purpose dam regions in the country. As a result, it was found that in the development and use of hydrothermal energy utilizing regional raw water supply line the urban planning conditions of the supply site can have a greater impact on the location selection results than the hydrothermal energy development itself. Due to the characteristics of the evaluation indicators developed in this study and their nature as comprehensive indicators, it is believed that the results should be applied to determine the overall adequacy of site selection in the early stages of hydrothermal energy development. In the future, it is believed that it will be necessary to analyze the problems in supplying and operating hydrothermal energy using raw water from multi-purpose dams and regional water resources. Based on the analysis the evaluation system developed in this study is expected to be improved and supplemented.

• 대한건축학회논문집:계획계
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• 제35권7호
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• pp.45-52
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• 2019

In recent years, there has been a demand for a residential supply model that can actively and flexibly cope with various housing demands in the changing paradigm of public rental housing. This study focuses on the two-step supply system that has been studied in Japan. It was used to examine and analyze cases to recommend a supply plan that can be used for domestic public rental housing. In more detail, the literature review of the two-step supply system discloses that four types by supply methods (A-1, A-2, B-2, and C-2) and four types of relationship (construction and management combine entities type, management entity type, construction entity type, a separated entity type) can be categorized. In addition, from the actual case study, it revealed that the way of linking and supplying activities among the entity can have a great influence on "ease of supply (supply)", "diversity of housing demand (diversity)," and "quality of construction (construction)". "Ease of supply (supply)" refers to whether the construction entity is separated, and the owner is a manager. "Diversity" refers to whether the management subject is separated, and if the owner is also the constructor or the manager. "Construction" is whether the management entity is connected and managed by the management entity and can be evaluated in "Good", "Middle", and "Bad" level. As a summary, even if the existing public rental housing in Korea can be separated into a skeleton and infill system, the result suggested that it has a limitation on response to residential demand. In addition, the paper was able to propose an improved plan to make the infill as a secondary operator.

• Journal of Biosystems Engineering
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• 제33권2호
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• pp.130-135
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• 2008

The purpose of this study was to develop a preprocessor for real-time portable quality evaluation system of milk. The preprocessor consisted of two flow pump to supply milk sample and reaction reagent at given volume, a fan to mix milk with reaction reagent, a thermoelectric device to maintain sample temperatures of $40^{\circ}C$, and I/O interface to control signals. The tests conducted with different level of flow rate of pump, fan speed, ambient temperature, and intial temperature of mixtures. To evaluate performance of the preprocessor, the supplied volumes, color changes, and temperatures were measured and analyzed. The results showed that the preprocessor could control supplying volumes, mixing, temperatures of samples automatically. The preprocessor showed good performance to be used for portable quality evaluation system of milk.

• 한국유체기계학회 논문집
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• 제9권3호
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• pp.36-43
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• 2006

Recently, micro hydropower and it's useful utilization are taking a growing interest as a countermeasure of global worming by carbon dioxide and exhaustion of fossil fuel. The purpose of this study is to investigate the possibility of extracting micro hydropower wasted by a valve in water supply system using micro cross-flow hydraulic turbine. In order to fulfill the functions of controlling flow rate and pressure in substitute for the valve, air and water are supplied into an air suction hole which is installed on the side wall of micro cross-flow hydraulic turbine. The results show that in case of supplying a lot of air into the air suction hole, about 50% of flow rate and relatively high value of loss coefficient are controlled by the turbine. Moreover, including high possibility of applying the micro cross-flow turbine to water supply system, extended application of the turbine to the water discharge system of drainage and irrigation canal.

• 생물환경조절학회지
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• 제9권1호
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• pp.11-19
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• 2000

본 연구는 다구역 양액재배에 적용할 수 있는 연속식 양액 자동조제공급 시스템 개발을 위한 목적으로 수행되었다. 기존의 정량펌프에 비해 정밀성 및 반복 구동회수에 대한 내구성이 우수하고 구동시간에 따라 토출량을 정밀 제어할 수 있는 원소별 농후액 공급조절장치를 개발하였으며, 개발된 원소별 농후액 공급조절장치의 시간당 토출량 실험 결과 결정계수는$R^2$＝0.9999이었고 3초~5초 구동시간동안의 회귀식에 의한 토출량과 실제 토출량 편차를 비교한 결과 최대 -1.23%로 나타나 회귀식에 의한 구동시간에 따른 토출량 제어가 가능함이 확인 되었다. 원소별 농후액 공급조절장치의 원소별 토출량 증감을 통하여 조성이 다른 양액을 조제할 수 있었으며, 생육단계에 따른 원소별 농도의 증감 조절에 사용할 수 있을 것으로 판단된다. 원수유입량 편차 실험 결과 목표 원수유입량과 실제 원수유입량간의 편차는 2.73% 이내로 나타났다. 세척 과정을 통해 EC가 1.4~l.6mS/cm인 경우에는 0.5~0.6mS/cm, 2.4~2.5mS/cm인 경우에는 0.9~l.0mS/cm 정도로 낮추어 급액 후 잔류 양액의 영향을 줄일 수 있었다. 개발된 다구역 재배용 양액 자동조제공급 시스템의 성능을 평가하기 위하여 오이용 야마자키액 조성의 배양액 180$\ell$를 조제, 공급하였을 때 양액에 포함된 N $O_3$$^{-}$, 와 P $O_4$$^{3-}$ 이온에 대하여 실험실에서 조제한 양액의 이온 농포와의 비교 실험을 3회에 걸쳐 실시한 결과, 개발된 시스템으로 조제한 양액중에 포함된 N $O_3$$^{-}$ 이온과 P $O_4$$^{3-}$ 이온은 실험실에서 조제된 양액에 비하여 각각 2.36%, 5.15% 낮게 나타났다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.104-107
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contact-less power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.