• 복식
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• 제67권4호
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• pp.116-130
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• 2017

The aim of this study is to investigate the general status, operating status, and the satisfaction level of participating textile-clothing companies involved in the Work and Learning Dual System in Daegu. The general status and operating status of the participating companies are as follows. As of March 2016, 34 of the 43 companies in Daegu participated in this survey, and they were divided into three areas of textile: weaving, dyeing & finishing, and apparel manufacturing. The breakdown is as follows: 14 dyeing & finishing companies (41.2%), 13 apparel manufacturing companies (38.2%), and 7 textile weaving companies (23.6%). The results of the survey showed that 91.2% of the companies decided to participate in the system to cultivate their employees into experts in the field. The satisfaction rate of the theoretical education and training institutions was 3.88 out of 5 points. In particular, the satisfaction rate of the textile weaving companies was as high as 4.29, and the satisfaction level of the dyeing & finishing companies was higher than the average of 3.71. The overall satisfaction rate for the work-related paradigm was 3.97 out of 5 points. The results of this survey can be used to conclude that the Work and Learning Dual System is operating as it was intended to be by the government.

• 대한기계학회논문집B
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• 제32권4호
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• pp.307-316
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• 2008

The objective of this study is to provide numerical and experimental data that can be used to investigate the performance characteristics of a flat plate fin-tube evaporator in household and commercial refrigerators under frosting conditions. Computer simulations with variations of operating conditions such as air inlet temperature, relative humidity, and geometries were performed to find out optimal design parameters of a fin-tube evaporator for household and commercial refrigerators. The tube-by-tube method was used in the simulation and the frost growth model was considered under frosting conditions. The developed analytical model predicted the decreasing rates of heat transfer capacity and air flow rate ratio within ${\pm}$10% compared to the experimental results for a refrigerator under real operating conditions. As a result, the frost thickness at $3^{\circ}C$ & 80% is increased 40% than that of $-3^{\circ}C$ & 80%, and the frost thickness at $3^{\circ}C$ & 90% is increased 30% than that of $3^{\circ}C$ & 60%. Accordingly, the operating time of the evaporator in the refrigerator was reduced with the increase of the decreasing rate of air flow rate ratio at each condition.

• Journal of Biosystems Engineering
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• 제28권6호
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• pp.525-530
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• 2003

This study was carried out to develop a vacuum nozzle seeder for the automation of large seeds sowing of fruit vegetables and rootstocks. Moreover, the seeding efficiency was examined to find the optimum operating condition considering high precision seeding. The important operating factors for high seeding rate were typically nozzle diameter and absorbing vacuum pressure. The optimum nozzle diameters were found 1.5, 1.5 and 2.0 mm for Chambak, Tuktozwa and Hukjong while the optimum vacuum pressures were 8.0㎪, 10.6㎪ and 5.3㎪, respectively. Under the optimum operating condition, the results indicated that the maximum seeding rates were 97.6％, 98.8％ and 97.6％ respectively for Chambak Tuktozwa and Hukjong. The vibrating acceleration of the hopper did not make any significant effects on the seeding rate when the vacuum pressure reached 8.0㎪ and the sowing rate became higher with lighter seed. As the seed became heavier, the larger diameter of nozzle was recommended 1.5mm of the nozzle diameter was found to be applied for the experimental seeds. The vacuum pressure was also found 8.0㎪ - 13.3㎪ at that time.

• 보건의료산업학회지
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• 제8권1호
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• pp.51-64
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• 2014

The purpose of this study was to investigate the relationship among staffing, occupancy rate, upward level change of long-term care need, and evaluation grade of facility. Data were obtained from National Health Insurance Corporation Database. Occupancy rate and evaluation grade were highest in National/public operating facilities, while they were worst in individual operating facilities. The percents of A or B grade in evaluation grade (by newly enforced law) is highest in National/public operating facilities. Multiple regression analysis showed that upward level change of care needs was very weakly associated with the number of doctors. Evaluation grade showed a weak and significant association with occupancy ratey(by old-version law)(r=.20, p<.01), upward level change of care need in group home(r=.23, p<.01) Staffing in facility did not show significantly consistent association with upward level change of care needs, evaluation grade, and occupancy rate.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.311-316
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• 2005

The experimental study for an operational characteristics and performance of the sodium heat pipe were carried out. For an experiment. the heat pipe which is 1000mm length and 25.4mm diameter of stainless steel container with 50 mesh of screen wick using sodium as a working fluid is manufactured and tested as functions of heat flow rate, inclined angle and operating temperature. The test results are as follows. During the start-up. frontal start up was observed because of the vapor density increasing as increased the hot zone. Also, the heat pipe showed uniform temperature over than $420^{\circ}C$ of the operating temperature. The average heat transfer coefficient increased as the heat flux and the vapor temperature increase, and the range of the total thermal resistance was 0.075-0.04 $^{\circ}C/W$ at the 12-53.55 $kW/m^2$ of heat flux and $500-750^{\circ}C$of operating temperature. The maximum heat flow rate was 750W at the 10 degree of top heating mode.

• 한국화재소방학회논문지
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• 제25권2호
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• pp.107-113
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• 2011

차동식 스포트형 공기 팽창식 열감지기를 인위적으로 높은 온도에서 가속열화시켜 경년변화되는 특성에 대하여 연구하였다. 이 연구는 현장에 설치된 감지기가 화재 또는 점검기기에 의한 고온의 열에 노출되었을 경우에 감지기의 동작에 미치는 영향을 분석하기 위하여 실험하였다. 실험결과 현장에서 5년 동안 사용되었던 2005년 B사 감지기는 $100^{\circ}C$의 온도에서 1시간 동안 노출되었을 경우에 감지기가 동작하지 않는 경우가 발생하였다. 이것은 감지기 감열실내의 팽창된 공기가 리크공 이외의 곳에서 리크 되었기 때문인 것으로 판단된다. 그러나 감지기의 동작표시를 나타내는 LED는 온도가 $160^{\circ}C$까지 올라갔음에도 불구하고 모두 정상적으로 동작하였다. 따라서 동작표시 LED의 회로소자는 고장은 발생하지 않았음을 알 수 있었다.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.31-38
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• 2009

Supercharging system was adopted to investigate the influence of boost pressure on operating range and exhaust emissions by using a supercharger at low temperature diesel combustion (LTC) condition in a 5-cylinder 2.7 L direct injection diesel engine. The experimental parameters such as injection quantity, injection timing, injection pressure and exhaust gas recirculation (EGR) rate were varied to find maximum operating range in LTC condition. As a result of adopting increased boost pressure in LTC, wider operating range was achieved compared with naturally aspirated condition due to increased mixing intensity. Increased boost pressure resulted in lower hydrocarbon (HC) and carbon monoxide (CO) emissions due to increased swirl rate and mixing intensity, which induced complete combustion. Moreover, increased boost pressure in LTC resulted in much lower soot emissions compared with high speed direct injection (HSDI) condition.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.179-182
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• 2004

ZnO varistor for transmission class arrester$({\Phi}65{\times}20mm)$ of 10kA(Class 3) grade was recently developed in korea and is tested for the properties by switching surge operating duty test to know the line discharge class and complex surge property in electric properties. To find out changing rate of residual voltage before and after lightning impulse residual voltage testing, the sample is cool to room temperature after finishing switching surge operating duty test, and the rate is good as 1.0~1.7%. The element had been considered as applicable ZnO varistor for electricity transmission from the test results of state conterl, switching surge operating duty, thermal stability and above test. But various test should be required for actual application because this is a part of the to be needed for application.

• 설비공학논문집
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• 제20권5호
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• pp.314-320
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the improved wall insulation. Hence, a multi~heat pump is required to cover heating and cooling simultaneously for each indoor unit. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the cooling-main operating mode were investigated experimentally. The system adopted a variable speed compressor using R410A with four indoor units and one outdoor unit. In the cooling-main mode, the heating capacity decreased due to reduction of flow rate to the indoor unit under heating mode operation. The EEV opening was adjusted to increase flow rate to the indoor unit under heating mode operation. The total capacity and COP in the cooling-main mode increased by 20.5% and 29.2%, respectively, compared with those in the cooling-only mode.

• 한국물환경학회지
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• 제23권5호
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• pp.761-765
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• 2007

The study were conducted in order to investigate the effect of operating parameters including the internal recycle (nitrification return) rates, hydraulic retention times (HRTs) and temperature when using a cilium media method. The first experiment was for evaluating the effect of HRT (12 hr, 10 hr, 8 hr, 6 hr, 4 hr). The second experiment was for analyzing effect of internal recycle rate (100%, 200%, 300%, 400%). As a result of the first experiment, BOD was removed to 97~98% for 6~8 hr HRT. Effluent water quality was not significantly influenced with HRT within that range. However the nitrogen removal was sensitive to HRT. T-P removal efficiency was invariable at various HRTs. The average BOD removal efficiency was about 97% in spite of change of internal recycle rate while T-N removal efficiency was increased at the internal recycle rate of 100~200%, but invariable at the internal recycle rate of 200~300%.