• 설비공학논문집
• /
• 제11권6호
• /
• pp.709-715
• /
• 1999

To optimize a heating and cooling system, we need an exact solution lot radiant heat transfer in any form of room or building. This paper describes the solution method of view factor by the area weighted average and graphical method to calculate the radiant heat exchange or daylighting level in any form of room or building. This study shows that the area weighted average and graphical methods have many points of merits(calculation speed, correctness and calculation capability in an arbitrary form of room shapes etc.) compared with existing methods

• 대한설비공학회지:설비저널
• /
• 제17권1호
• /
• pp.28-43
• /
• 1988

The purpose of this research is to produce bin weather data for Seoul from Standard Weather Data. The intended use of these data is for input to recently developed models for simplified energy calculations and for generating variable-base degree-day information. The data produced under this study include $3^{\circ}C$ bin data covering the full range of dry-bulb temperatures with mean coincident wet-bulb and daytime coincident solar radiation, wet-bulb bins down to freezing temperature, wind speed bins with prevailing directions, and heating and cooling degree hours to nine different temperature bases. All of these data are tabulated in six separate time periods and total daily categories for monthly and annual periods.

• Applied Science and Convergence Technology
• /
• 제23권2호
• /
• pp.83-89
• /
• 2014

Adsorption of residual gas molecules damped the emission current of a W (310) field electron emission (FE) emitter. The damping speed was linearly proportional to the pressure gauge readings at pressure ranging from ${\sim}10^{-8}Pa$ to ${\sim}10^{-9}Pa$, and the proportionality constant was employed to measure pressure in the $10^{-10}Pa$ range. A time plot of FE current revealed the existence of an "initial stable region" after the flash heating of W(310) FE, during which the FE current damps very slowly. The presence of non-hydrogen gas removed this region from the plot, supplying a means of qualitatively analysing the gas species.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2010년도 추계학술대회
• /
• pp.345-346
• /
• 2010

The HVAC(Heating Ventilation and Air Conditioning) system is only controlled by turn on/turn off operations against to AC 380V input. Therefore, the efficiency of the system is reduced and noise occurs. Also, the blower is shut down at the AC power failure. In this paper, the inverter system with UPS function for the A/C(Air Conditioning) blower is proposed. Proposed inverter system which is powered from the AC and DC voltage can control speed, operation mode, and soft-start time using CAN communication. In case of the CAN communication failure, RS-232 communication could be used to control the hardware directly by the engineer that can solve existing problems. To verify the validity of proposed inverter system, simulations and experiments are carried out.

• 설비공학논문집
• /
• 제18권4호
• /
• pp.359-369
• /
• 2006

This study aims deriving analysis the flow characteristic of kitchen hood system with using 3-D numerical analysis method and improving the system to expel pollutes more efficiently. This system is applied with $k-{\varepsilon}$ turbulent model and using incompressibility viscosity flow range and boundary condition which are related to Bossinesq approximation following density variation in control volume. To understand the flow characteristics of four models, this study only focuses on velocity field, temperature field, and concentration field varying with followings whether separation plate is set or not and the shapes of separation plates. The quantity of air, speed of exhaust fan and temperature and concentration of heating source are concerned as constant values.

• 디지털콘텐츠학회 논문지
• /
• 제19권6호
• /
• pp.1213-1218
• /
• 2018

최근 비전분야에 소개된 Mask R-CNN은 객체 인스턴스 세분화를위한 개념적으로 간단하고 유연하며 일반적인 프레임 워크를 제시한다. 이 논문에서는 열적외선 카메라로부터 획득한 열감지영상에서 발열체인 인스턴스에 대해 발열부위의 세그멘테이션 마스크를 생성하는 동시에 이미지 내의 오브젝트 발열부분을 효율적으로 탐색하는 알고리즘을 제안한다. Mask R-CNN 기법은 바운딩 박스 인식을 위해 기존 브랜치와 병렬로 객체 마스크를 예측하기 위한 브랜치를 추가함으로써 Faster R-CNN을 확장한 알고리즘이다. Mask R-CNN은 훈련이 간단하고 빠르게 실행하는 고속 R-CNN에 추가된다. 더욱이, Mask R-CNN은 다른 작업으로 일반화하기 용이하다. 본 연구에서는 이 R-CNN기반 적외선 영상 검출알고리즘을 제안하여 RGB영상에서 구별할 수 없는 발열체를 탐지하였다. 실험결과 Mask R-CNN에서 변별하지 못하는 발열객체를 성공적으로 검출하였다.

• 한국결정성장학회지
• /
• 제11권5호
• /
• pp.197-202
• /
• 2001

여러 조건에서 제조된 poly(ethylene terephthalate) 필름 시편들로부터 열처리 및 냉연신 조건이 시편의 물성에 미치는 영향을 조사하였다. 상온에서 만능시험기을 사용하여 미열처리 및 열처리된 시편들을 0.5에서 500 mm/min의 cross-head 속도로 단계적 연신을 행한 결과, 약 50, 72 및 $129^{\circ}C$에서 열처리된 시편들의 응력-변형 곡선에서는 응력 진동이 발생되지만, 약 $83^{\circ}C$에서 30분 동안 열처리된 시편의 응력-변형 곡선에서는 응력 진동이 발생되지 않음을 알 수 있었다. 시차 주사 열량기를 사용하여 $10^{\circ}C$/min의 승온 속도에서 열분석을 행하였고, 시편들의 유리전이온도, 결정화 피크, 용융 잠열, 결정화도를 측정하였다. 1 Hz의 주파수대에서 $1.5^{\circ}C$/min의 승온 속도로 multiple-function internal friction pendulum으로 시편들의 동적 기계분석도 수행하였으며, 미열처리, 열처리 및 연신 시편들의 순서대로 탄성계수 값이 증가함을 알 수 있었다.

• 한국의류학회지
• /
• 제19권1호
• /
• pp.36-50
• /
• 1995

The purpose of this study was 1) to estimate the improvement of thermal storage/release and moisture transport properties of PEG-treated acrylic athletic socks and suggest the optimum add-on for PEG treatment, 2) to investigate wear performance of untreated cocks and two kinds of socks treated with PEG of minimum and optimum add-on respectively, and 3) to consider the effect of thermal storage/release and moisture transport properties of PEG- treated socks on the wear performance and the subjective comfort zone. Thermal activities of specimens treated by PDC were evaluated on a DSC by measuring the heat of fusion on heating and the heat of crystallization on cooling. Moisture regain, absorption speed, wickability, water retenti on value, and water-vapor permeability were measured. In the wear trials that the subjects performed a subsequent exercise protocol wearing three differently treated socks in a conditioned environment ($14\pm2^{\circ}C$, 65$\pm$2% R.H.), microclimate temperature and humidity, and subjective wear sensations including thermal sensation, wettedness, softness, fit, and overall comfort were obtained. PEC-treated specimens with more than 20% add-on showed thermal storage on heating and thermal release on cooling by a DSC and the heat contents of treated ones were generally proportional to the add-ons. Moisture transport properties were highly improved after PEG treatment and increased rapidly with increasing add-on. The tendencies were, however, relaxed above 50% add-on and the treated knits were much stiffer above that add-on. In the wear trials of untreated, PEG add-on 20%, and 50% acrylic socks, the changes of microclimate temperature of 50% socks were significantly less than that of 20% socks. PEG add-on 50% socks showed significantly less changes of microclimate humidity than other two kinds of socks. Three kinds of socks showed significant differences in overall comfort and add-on 50% socks were accepted more comfortable than other two kinds of socks. Comfort zone of foot was extended after PEG treatment on socks and it implied that the subjects wearing PEG- treated socks felt comfortable in wider ranges of microclimate temperature and humidity.

• 대한기계학회논문집B
• /
• 제39권8호
• /
• pp.703-711
• /
• 2015

작업의 효율을 높이기 위해서 대형 공장에서 개구부는 주로 개방 되어 있다. 그러나 동절기에 공장에서 난방을 하는 경우 개방되어 있는 개구부는 난방부하를 상승시키는 큰 요인이다. 때문에 공장에서는 개구부 상단에 에어커튼을 설치하여 외부의 침기를 막아 난방부하를 낮춘다. 일반적인 에어커튼의 설계 변수로는 토출 각도와, 속도, 온도 등이 존재하며 이에 대한 연구는 이미 많이 진행되었다. 하지만, 공장이라는 공간적 특수성을 고려하였을 때, 기존에 연구되지 않은 개구부로부터의 이격 거리와 토출구 폭에 대한 부분도 차단 성능에 영향을 미친다. 그 결과 에어커튼은 이격 거리가 가깝고, 토출구 폭은 넓을수록 차단 성능이 좋았다. 이격 거리가 존재하더라도 토출구 폭을 증가시키면 차단 성능이 향상되었으며, 토출구 폭을 증가시킴으로써 약 13.7%의 차단 성능의 향상을 기대할 수 있다.

• 한국수산과학회지
• /
• 제49권1호
• /
• pp.20-25
• /
• 2016

This study elucidated the effects of physicochemical factors on the production of cooked rice analogs using calcium alginate gels. Cooked rice analogs were prepared using various sodium alginate concentrations, agitation speeds, dropping distances, coating times, curing times and heating times. The diameter ratio and rupture strength of authentic cooked rice were 0.38 and 268.4 kPa, respectively. The diameter ratio of the analogs prepared with 0.7% (w/v) sodium alginate was 0.39, which was the closest to that of authentic cooked rice. When sodium alginate solution (0.7%, w/v) was dropped into calcium chloride solution (2%, w/v) via a nozzle, the diameter ratio of the analogs at an agitation speed of 520 rpm was 0.39. The optimal dropping distance was 8 cm and the optimal coating and curing times were each 20 min. The analogs were coated with β-cyclodextrin to improve their physical properties. The diameter ratio of the coated analogs was little changed; however, the rupture strength decreased slightly after heating for 60 min at 95°C.