• 설비공학논문집
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• 제25권11호
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• pp.612-616
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• 2013

A circular CAV damper has been developed, based on the investigation of the pressure loss, and the flow-resisting moment by the damper blade. When a torsional spring is attached to the damper axle, and the setting angle is adjusted to around $82^{\circ}$, the volume rate across the damper is almost independent of the static pressure. Such a CAV characteristic appears at an opening angle between $40^{\circ}$ and $60^{\circ}$, where the normalized moment decreases linearly with the angle. In addition, by adjusting the setting angle, the volume rate can be controlled to within 10% error, regardless of the pressure loss.

• Journal of Korean Society for Atmospheric Environment
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• 제20권E2호
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• pp.61-68
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• 2004

Aerosol losses in a 100L Tedlar$^{(R)}$ bag were investigated for the aerosols with number median diameter of 0.05 ${\mu}{\textrm}{m}$ and number concentration of 6.4 ${\times}$ 10$^4$ cm$^{-3}$ . Over a 1 hr period, loss of particles in the bag is apparent, and the volume decrease with time is significant. The number concentration, surface area, and volume concentration of the aerosols decreased to 34, 50, and 52% of the initial value in 30 min, respectively. This indicates that deposition to the walls was the main loss process for aerosols in the Tedlar$^{(R)}$ bag. Theoretical calculations showed that coagulations and deposition by diffusion and gravitational sedimentation would not change aerosol characteristics significantly, and the electrical force was the dominant loss process for particles in the Tedlar$^{(R)}$ bag over a 1 hr period.eriod.

• 대한토목학회논문집
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• 제37권2호
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• pp.485-495
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• 2017

지하공간 개발은 인구증가로 인한 도심지의 지상공간 대형화로 발생되는 다양한 문제를 해결하기 위한 유용한 해결책이며, 그 중 터널은 지하공간 개발의 방법 중 가장 많이 사용되고 있는 방법이다. 터널 굴착에 따른 말뚝과 지반의 거동에 대한 연구는 많은 연구자들에 의해 수행되어 왔다. 하지만, 말뚝의 축력 분포에 대한 연구는 아직까지 많이 이루어지지 않은 실정이다. 따라서 본 연구는 느슨한 사질토 지반에서의 군말뚝 기초하부에 터널굴착으로 인한 지반의 거동 뿐만 아니라 각각의 말뚝의 축력분포를 실내모형시험을 통해 관찰하였다. 터널굴착을 모사하기 위해 체적손실율 개념을 적용하였으며, 말뚝과 지반의 파괴 메커니즘을 확인하기 위하여 일반적으로 사용하는 체적손실율(1~2%) 보다 큰 10%까지 단계별로 적용하였다. 실내모형시험 결과 체적손실율 1.5% 적용에 의해 급격한 축력감소가 발생하였으며, 말뚝의 침하량이 인접 지반의 침하량보다 1.2~4.7배 가량 더 큰 것으로 나타났다. 실내모형시험 중 근거리 사진계측 기법을 사용하여 체적손실율 1.5%일 때의 지중 거동을 정량적으로 분석하였으며, 실내모형시험 결과를 수치해석결과와 비교하였다.

• 한국조리학회지
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• 제23권4호
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• pp.125-134
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• 2017

This study aimed to examine quality properties of muffin by the amount of addition of Korean whole wheat flour (0%, 25%, 50%, 75%, 100%) as there is increasingly higher interest in the healthy food. The effect of Korean whole wheat flour were evaluated in terms of height, volume, weight, specific volume, baking loss rate, colorimeter, and sensory evaluation. Texture and moisture contents of muffins when storage (1, 3, 5 days) was measured. As the ratio of Korean whole wheat flour increased, the baking loss rate and weight increased, whereas the volume and specific volume was not significant. During storage, moisture content of muffins decreased significantly. The addition of Korean whole wheat flour increased lightness (L value) of crust and crumb decreased, whereas redness (a value) and yellowness (b value) increased. The control group (CON) showed the highest springiness lowest hardness. The muffin with 25% of Korean whole wheat flour (WHF25) in test group showed the high springiness low hardness. According to the sensory evaluation, the control group showed the highest score in terms of taste, however WHF25 showed the highest score in appearance, color, flavor, texture and overall acceptance, WHF25 showed the best result and the optimum addition of Korean whole wheat flour. Furthermore, this study proposes the possibility of development of various confectionery with using Korean whole wheat flour.

• 동아시아식생활학회지
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• 제24권6호
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• pp.802-810
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• 2014

This study investigated the quality characteristics of muffins prepared with tagatose. The effect of tagatose were evaluated in terms of height, volume, weight, specific volume, baking loss rate, moisture contents, colorimeter, sensory evaluation, and texture of muffins during storage (1, 3, 5 days) and texture was measured using a texture analyzer. As the ratio of tagatose increased, the volume, specific volume, baking loss rate, and height decreased, whereas moisture content increased. During storage, control without tagatose showed the highest springiness lowest hardness by TPA, whereas hardness of muffins increased and springiness decreased as the contents of tagatose increased. Lightness of crust and crumb decreased significantly as contents of tagatose increased. According to the sensory evaluation, the control group showed the highest score in terms of texture but was not significant with 2% tagatose (T2). For appearance, color, flavor, taste, and overall acceptance, T2 showed the best result.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권1호
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• pp.20-23
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• 2004

BLDCMs are widely used in many industries. In certain specialized areas, they need to have high efficiency, high power rate and produce a low volume of noise, etc. In this study, a new type of slotless BLDCM is proposed that has no cogging torque, low iron loss and low volume as compared to commonly used BLDCMs. With a high performance magnet and coreless compact winding structure similar to those employed in linear synchronous motors, motor volume is reduced. The proposed motor has been put been through various experiments arid has demonstrated acceptable results for industry applications.

• 한국태양에너지학회 논문집
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• 제39권6호
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• pp.27-40
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• 2019

Kitchen hoods are limited in discharging all contaminants produced during cooking. Contaminants that have not been discharged can rise to the upper part of the kitchen and become stacked. To solve this problem, there is a way to increase the air volume of the kitchen hood, but there are limits, so a new system is required. This study proposes the Duct System (IADK : Inducing Airflow Duct system for Kitchen hood )through 3D printers and experiments. To do this, the pressure is measured to verify the three levels of air volume provided by the kitchen hood. To check the degree of loss of flow in the existing kitchen hood system, install flexible ducts alone to measure the pressure. Change the internal diameter and type of connection of the IADK and measure the pressure. The air pressure, static pressure difference, and loss factor are calculated and analyzed using the pressure measured through the experiment.

• 전력전자학회논문지
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• 제25권1호
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• pp.21-28
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• 2020

Integrated bidirectional OBC/LDC was developed to reduce the volume for elements, avoid space restriction, and increase efficiency in EV vehicles. In this study, a DC-DC converter in integrated OBC/LDC circuits was composed of an SRC circuit with a stable output voltage relative to an LLC circuit using a theoretical method and simulation. The resonant network of the selected circuit was optimized to minimize the power loss and element volume under constraints for the buck converter and the battery charging range. Moreover, the validity of the optimal model was verified through an analysis using a theoretical method and a numerical analysis based on power loss at the optimized resonant frequency.

• 설비공학논문집
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• 제13권2호
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• pp.96-105
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• 2001

R410a which is one of HFC refrigerants is being considered to be a promising replacement for R22 widely used in domestic air conditioners. The rolling piston type rotary compressors for R410a have lower energy efficiency than those for R22 because of the high pressure difference between a suction chamber and a discharge chamber in the compression mechanism. in addition, the re-expansion gas loss of the rotary compressor for R410a which occurs a ta clearance volume in a discharge port becomes larger than that for R22 due to high density of R410a refrigerant. Therefore, Pressure-Volume analyses for various design parameters of a discharge system were carried out to improve efficiency of a R410a rotary compressor. The results such as performance dta, over-compression loss, and re-expansion loss were acquired by P-V analyses and analyzed quantitatively. As a conclusion, the optimal specifications of several design parameters of a discharge system were obtained by analyzing P-V diagrams.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권1호
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• pp.65-68
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• 1999

Multiple facial trauma patient should be carefully treated because of severe bleeding on extraoral and intraoral wound, possibilty of airway obstruction and hypovolemic shock. Hypovolemic shock may be divided to hemorrhagic shock and non-hemorrhagic shock. Also hemorrhagic shock is divided to mild, moderate and severe shock according to the degree of blood volume depletion. Mild shock occurs in blood loss of less than 20% of blood volume and moderate shock does in blood loss of 20-40% of blood volume. And Severe shock occurs in blood loss of more than 40% of blood volume. The goal of emergency care of trauma patient is that respiration and perfusion should be recovered to satisfactory level and that normal vital sign is maintained. We reported the case of multiple facial trauma patient with severe bleeding and hopovolemic shock and metabolic acidosis who was treated with adequate supply of fluid transfusion, intubation, tracheostomy and emergency operation.