• 제목/요약/키워드: central heating

검색결과 205건 처리시간 0.024초

Fuzzy-Neuro Controller for Control of Air-Conditioning System

  • Lee, Sang-Bae
    • 한국지능시스템학회논문지
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    • 제5권1호
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    • pp.33-42
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    • 1995
  • A practical application of a fuzzy-neuro controller is described for an air-conditioning system. Air-handing units are being widely used for improving the performance of central air-conditioning systems. The fuzzy-neuro control system has two controlled variables, temperature and humidity and three control elements, cooling, heating, and humidification. In order to achieve high efficiency and economical contorl, especially in large offices and industrial buildings, two controllable parameters, temperature and humidity, must be adequately controlled by the three final controlling elements. In this paper a fuzzy-neuro control system is described for controlling air-conditioning systems efficiently and economically. Simulation results confirmed that the fuzzy neuro control system is effective for this multivariable system.

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에어콘의 효과적인 퍼지 제어 시스템의 설계 (The Design of Efficient Fuzzy Logic Control System for Air-Conditioner)

  • 김일;이상배;이철영
    • 한국항해학회지
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    • 제18권4호
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    • pp.147-154
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    • 1994
  • A practical application of a fuzzy control system is described for an air-conditioning system. Air-hadling units are being widely used for improving the performance of central air-conditioning systems. The fuzzy control system has two controlled variables, temperature and humidity, and three control elements, cooling, heating, and humidification. In order to achieve high efficiency and economical control, especially in large offices and industrial buildings, two controllable parameters, temperature and humidity, must be adequately controlled by the three final controlling elements. In this paper a fuzzy control system was described for controlling air-conditioning systems efficiently and economically.

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퍼지 LMS 알고리즘을 이용한 공조덕트에서의 능동소음제어 (Active Control of Noise in HVAC Ducts Using Fuzzy LMS Algorithms)

  • 남현도;안동준;박용식
    • 소음진동
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    • 제9권2호
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    • pp.265-272
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    • 1999
  • A LMS algorithms has been widely used for an adaptive filter algorithm in active noise control systems. But this algorithm has poor convergence and it is very difficult to select optimal convergence parameters in this algorithm. In this paper, a fuzzy LMS algorithm where the convergence parameters are computed using a fuzzy logic controller was proposed. A proposed algorithm was applied to active noise control system in HVAC(central Heating Ventilation and Air Conditioning) ducts. The experimental ducts and experimental apparatus were designed and manufactured for experiments, and the modelling of the experimental ducts was also performed for computer simulations. Computer simulations and experiments were performed to show the effectiveness of a proposed algorithm.

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모델 시스템을 이용한 제조 조건이 단무지의 색도 및 경도에 미치는 영향 (Effects of Process Conditions on the Color and Firmness of Salted Radish Root (Danmooji) at Model System)

  • 구경형;박완수;이경아
    • 한국식품영양과학회지
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    • 제34권9호
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    • pp.1477-1484
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    • 2005
  • 단무지 조미액 성분이 단무지 품질에 미치는 영향 조사와 단무지 조미액의 pH($X_1$), 열처리 조건($X_2$)의 영향 및 저장온도와 기간별 단무지의 색도 및 조직감 변화를 조사하였다. 개별 단무지 조미액 성분이 단무지의 색도 및 경도 변화에 미치는 영향의 경우, 증류수 침지군을 기준으로 AD9(acetic acid) 침지군을 제외하고 AD3(polyphosphate), AD5(citric acid), AD2(malic acid)은 색도 변화와 단무지 연화를 지연시켰다. 반면에, AD1(potasium sorbate), AD7(succinic acid), AD8(MSG), AD6(saccharin) 처리구는 색도 변화와 경도 감소를 가속화시켰다. 또 단무지 조미액과 열처 리 조건의 영향은 중심 합성 계획 (central composite design)과 반응표면 분석법(response surface analysis)을 이용하여 분석하였다. 그 결과 독립 변수와 종속 변수의 상관 정도를 나타내는 $R^2$값이 종속변수 경도 값을 제외하고 0.8이상이었으며, 특히황색도를 나타내는 b값은 0.899을 나타내었다. 각 개별 독립변수와 교차 분석 결과 독립 변수인 $X_1$(pH)과 $X_2$(가열시간)모두 단무지의 색도와 조직감 변화에 영향을 끼쳤다. 또 저장 온도의 경우, $40^{\circ}C$에서 저장한 단무지의 색도가 다른 온도에 저장한 시료에 비하여 저장기간이 증가함에 따라 급속한 색도 변화와 연화가 진행되었다.

8 MHz 라디오파를 이용한 자입식 온열치료 -조직등가물질을 통한 온도분포 및 개 뇌실질의 조직병리 변화에 관한 연구- (Interstitial Hyperthermia by Radiofrequency Needle Electrode System : Phantom and Canine Brain Studies)

  • 이형식;추성실;성진실;서창옥;김귀언;노준규;김영수;김선호;정상섭;한은경;김태승
    • Radiation Oncology Journal
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    • 제9권1호
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    • pp.27-35
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    • 1991
  • 8MHz 라디오파를 이용한 자입식 온열치료를 위한 기초실험의 일환으로 조직등가물을 이용하여 다양한 needle electrode의 배열을 통한 적정 온도분포를 규명하고자 하였고, 직접 개의 뇌실질에 자입 온열요법을 시도하여 이에 따른 조직 병리학적 소견을 관찰하고자 하였다. 조직등가물 실침에서 저자들은 needle electrode 1 cm 간격의 정방형 배치에서 횡단면상 $90\%$ relative SAR 분포가 약 1.25 cm 반경의 균일한 원형으로 관찰됨을 알 수 있었고 종단면상 needle electrode의 길이에 따라 균일한 온도분포가 이루어짐을 관찰할 수 있었다. 정상 개의 뇌실질에 자입하여 직접 정방형의 중심을 $43^{\circ}C$로 유지하며 50분간 온열요법을 시행한 후 관찰한 조직 병리학적 소견은 liquefactive necrosis, pyknosis of neuronal element 및 Polymorphonuclear leukocytes들이 회백질에서 급성기에 관찰 되었고 liquefactive necrosis 주위에 lipid-laden macrophage들이 관찰됨이 공통적인 특징 이었으며 후기 변화로 괴사조직 주위로 신경교세포의 증식이 관찰되었다.

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난방도일 기반 대한민국 행정구역별 기후존 구분 기준 정립에 관한 연구 (A Study on the Classification Criteria of Climatic Zones in Korean Building Code Based on Heating Degree-Days)

  • 노병일;최재완;서동현
    • 설비공학논문집
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    • 제27권11호
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    • pp.574-580
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    • 2015
  • Climatic zone in building code is an administrative district classification reflecting regional climatic characteristics. Use of Degree-Days is a fundamental method that can be used in various building design codes, analysis of building energy performance, and establishment of minimum thermal transmittance of building envelopes. Many foreign countries, such as the USA, the EU, Australia, Italy, India, China, etc., have already adapted climatic zone classification with degree-days, precipitation or amount of water vapor based on the characteristics of their own country's climate. In Korea, however, the minimum requirements for regional thermal transmittance are classified separately for the Jungbu area, Nambu area and Jeju Island with no definite criterion. In this study, degree-days of 255 Korean cities were used for climatic zone classification. Outdoor dry-bulb temperature data from the Korea Meteorological Administration for 1981~2010 was used to calculate degree-days. ArcGIS and the calculated degree-days were utilized to analyze and visualize climatic zone classification. As a result, depending on the distribution and distinctive differences in degree-days, four climatic zones were derived : 1) Central area, 2) Mountain area of Gyeonggi and Gangwon provinces, 3) Southern area, and 4) Jeju Island. The climatic zones were suggested per administrative district for easy public understanding and utilization.

고유 변형도법과 리메슁 기술을 접목한 블록의 역세팅 형상 예측기술 (Prediction Technology of Reverse Setting Block Shape with Inherent Strain Method and Re-meshing Technology)

  • 현충민;최한석;박창우;김성훈
    • 한국해양공학회지
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    • 제31권6호
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    • pp.425-430
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    • 2017
  • In order to reduce the cost of corrections and time needed for the block assembly process, the reverse setting method is applied for a back-heated block to neutralize deck deformation. The proper reverse setting shape for a back-heated block to correct deformation improved the deck flatness, but an excessive amount of reverse setting could inversely affect the flatness of the block. A prediction method was developed for the proper reverse setting shape using a back-heated block, considering the complex geometry of blocks, thickness of the deck plate, and thermal loading conditions such as welding and back-heating. The prediction method was developed by combining the re-meshing technique and inherent strain-based deformation analysis using the finite element method. Because the flatness deviation was decreased until the lower critical point and thereafter it tended to increase again, the optimum value for which the flatness was the best case was selected by repeatedly calculating the predefined reverse setting values. Based on this analysis and the study of the back-heating deformation of large assembly blocks, including the reverse setting shape, the mechanism for selecting the optimum reverse setting value was identified. The developed method was applied to the actual blocks of a ship, and it was confirmed that the flatness of the block was improved. It is concluded that the developed prediction method can be used to predict the optimum reverse setting shape value of a ship's block, which will reduce the cost of corrections in the construction stage.

Optimization of the Processing Conditions for Heated Garlic Juice by Response Surface Methodology

  • Lee, Youn-Ri;Lee, Yun-Kyoung;Hwang, In-Guk;Lee, Yoon-Jeong;Woo, Koan-Sik;Han, Chung-Su;Kim, Eui-Su;Jeong, Heon-Sang
    • Preventive Nutrition and Food Science
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    • 제13권4호
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    • pp.334-339
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    • 2008
  • This study was designed to determine the optimum conditions of heating temperature, heating time and dilution rates for producing heated garlic juice by using central composite design of response surface methodology. Garlic 3Department of Biosystems Engineering, Chungbuk National University, Cheongju 361-763, Korea was heated using a high temperature and pressure treatment apparatus. Total soluble solid contents ranged from 4.4 at $130^{\circ}C$ 3 hr and 6 fold dilution to 5.89 at $115^{\circ}C$ for 2 hr and 8 fold dilution. The highest total acidity was 0.55% at $120^{\circ}C$ for 3 hr and 2 fold dilution. The pH ranged from 4.01 at $130^{\circ}C$, 3 hr and 6 fold dilution to 5.85 at $120^{\circ}C$, 1 hr and 6 fold dilution. From the results of statistical analysis on the sensory evaluation the predicted optimum processing conditions for best color, taste, flavor and overall acceptance were $119.41^{\circ}C$, 3.11 hr, 5.85 fold dilution, $118.23^{\circ}C$, 3.57 hr, 3.15 fold dilution, $120.54^{\circ}C$, 3.47 hr, 5.01 fold dilution and $119.54^{\circ}C$, 3.18 hr, 5.66 fold dilution, respectively. The application of response surface methodology for preparing heated garlic juice processing showed a good correlation with high significance.

파라핀을 채운 수직원관 내에서의 열전달 특성 (Heat Transfer Characteristics for Inward Melting in a Paraffin-Filled Vertical Cylinder)

  • 염성배;홍창식
    • 태양에너지
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    • 제12권3호
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    • pp.60-69
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    • 1992
  • 본 연구에서는 고-액 상변화 시의 잠열을 이용한 축열방법 중에서 고상파라핀을 충전한 수직원관의 관벽을 가열하여 축열하는 경우에 대하여 관 내에서 일어나는 열전달 특성과 축열속도를 이론적으로 해석하였다. 액상에서는 자연대류를 고려하였고 고상에서는 순수 열전도 모델을 사용하였다. 고상파라핀의 초기온도와 관벽의 가열온도 그리고 관의 형상비가 축열속도에 미치는 영향을 알아보았으며, 전체 열전달과정을 순수열전도 모델로 해석하여 자연대류가 축열에 미치는 영향을 고찰하였다. 용융초기에는 관벽과 고액경계면의 영향으로 자연대류에 의한 유동은 장애를 받으나, 40% 정도의 용융이 진행된 후 부터는 내부 액상에서의 자연대류가 활발히 일어나고, 용융중기로 갈수록 관의 상부에 뜨거운 액상층이 축적되므로 자연대류는 소멸하게 된다. 전체적인 융용속도는 순수열전도에 의한 용융속도보다 빨라지게 된다. 관벽의 가열온도와 형상비가 증가할수록 관 내에서의 자연대류가 활발하게 일어나므로 용융속도는 빨라지며, 형상비가 클수록 상하부 간에 불균등한 용융이 일어난다. 고상의 초기온도는 초기의 용융속도에 큰 영향을 미치고 용융이 진행될수록 그 효과는 줄어든다.

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중국연변지역 조선족과 한족 농촌주택의 변화에 관한 비교연구 (A Contrastive Study on the Change of Rural Houses of the Han Chinese and Korean-Chinese in Yanbian Area of China)

  • 허성걸;조원석
    • 한국농촌건축학회논문집
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    • 제18권2호
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    • pp.29-37
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    • 2016
  • This study is aimed to suggesting a hypothesis about the process of improvement of houses of the Korean-Chinese, comparing how Han Chinese and Korean-Chinese houses changed in Yanbian Area of China. This draws the conclusion by analyzing the field survey about residence of the Han Chinese and the Korean-Chinese in Yanbian Area of China. First of all, the characteristic of residence style change and the plan of rural houses of the Han Chinese are in the following. The plan of houses has been changed from allocating rooms from side to side with the kitchen as the center to linking each functional spaces through the aisle. And the main bedroom of houses becomes the central space for family members instead of Kang (partial Ondol) by expanding the floor heating system under the whole floor in houses. Next, the feature of residence style changes of the Han Chinese and the Korean-Chinese is as follows. In 1970s barns disappeared from houses of the Korean Chinese, but houses of the Han Chinese were not much changed. From 1980s to 1990s, spaces linking each rooms with aisles had appeared for comfortableness of residence and respecting each individual's privacy. On the other hand, The houses of the Korean-Chinese make a whole big space by getting rid of walls between the rooms. And after 2 thousand years later, Han Chinese houses have a bedroom with floor heating system. Both houses of the Korean-Chinese and the Han Chinese are changed to have a residence style which taking sedentary style and standing style.