• 한국의류학회지
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• 제24권3호
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• pp.335-344
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• 2000

The purpose of this study was to set up sizing system for knit trainning wears. Sample size was 198 females and their age range was from 15 to 24 years old. The body types for sizing system for knit trainning wears were divided by height and drop values. The results were as follows. 1. The height could be divided into three groups and they covered 97.5%. The Short(152cm) covered 27.8%, the Regular(160cm) 51.0% and the Tall(168cm) 18.7%. 2. The Medium hip(drop value 6) and the Large hip(drop value 12)had the high coverage rate of 45.5% and 46%, and the Small hip(drop value 0) had the low coverage rate of 8.6%. 3. For sizing system for knit trainning wears, the intervals of bust girth and hip girth were 5cm and 4cm. In the same size of bust girth, the intervals of hip high girth and waist girth were 1cm, the intervals of back waist length and sleeve length were 2cm and the interval of slacks length was 4∼5cm according to three height groups.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2615-2620
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• 2007

This paper describes on pressure drop in a circular pipe of refuse collecting system. The flow characteristics inside the circular pipe are analyzed by three-dimensional Navier-Stokes analysis. In numerical analysis, an organic waste is modeled using the data obtained by site survey. Pressure drop obtained by numerical simulation is compared to the value obtained by experimental measurements for the two kinds of pipe; straight and bended type. The pressure drop obtained by numerical simulation has a good agreement with that of experiments. It is noted that the accurate prediction of pressure drop in the waste pipe is very important to determine the performance of turbo blower used in making a suction pressure in the waste pipe. Especially, the pressure drop for an organic waste is analyzed according to the mass flow rate of waste.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.400-402
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• 1994

The voltage drop in distribution path of battery-reserved DC power system can affect the total of battery, cable and electricity costs. To determine an optimum voltage drop in distribution path for minimizing the total cost, battery, cable and electricity costs are represented as a function of the voltage drop, respectively, and are summed up to the total cost. An optimum voltage drop is selected as the value giving the minimum total cost. In this paper, a design technique of optimum voltage drop in distribution path of DC power system is proposed to minimize the total of battery, cable and electricity costs. The design procedure is described and design curve for selecting optimum voltage drop is also presented as a function of distribution distance.

• 대한기계학회논문집B
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• 제23권5호
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• pp.678-686
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• 1999

The purpose of this work is to Investigate the pressure drop and the heat transfer characteristics in the channel of plate heat exchanger with crossed-discrete ribs. The flow is assumed to be three-dimensional, laminar and periodically fully developed. Computations have been carried out for angles of attack from $0^{\circ}$ to $90^{\circ}$ and ratios of rib height from 0.15 to 0.46 for various values of Reynolds and Prandtl numbers. The heat transfer was improved by inclined ribs generating helical vortices and secondary flows. The results show that the pressure drop has a maximum value at $70^{\circ}$ and the heat transfer has a maximum value at $45^{\circ}$. As the rib height increases, the pressure drop and the heat transfer increase quadratically, and the increasing rate of pressure drop is higher than that of the heat transfer. As Reynolds number increases, the pressure drop increases in proportion to the square of Reynolds number and the heat transfer increases linearly.

• 설비공학논문집
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• 제15권2호
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• pp.109-115
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• 2003

The performance of two vertical-blade eliminators (V1, V2) and two horizontal-blade ones (H1, H2) for absorption chillers were tested in terms of pressure drop and refrigerant entrainment. The test was carried out using a wind tunnel with a cross section of 300 mm$\times$300 mm. The pressure drop of four eliminators tested was found to be in the rage of 1.0~2.7mm $H_2O$ at the face velocity of 2m/s. In the refrigerant entrainment test the vertical-blade eliminators showed much better performance than the horizontal-blade ones. The horizontal-blade eliminators showed satisfactory results at the air velocity of 2m/s but exceeded the limit value at 3 m/s. Since the cooling capacity of a machine is lowered by about 2.5% at the pressure drop of 1 m $H_2O$, more researches are required to reduce the pressure drop in the eliminator.

• Journal of Mechanical Science and Technology
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• 제19권12호
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• pp.2289-2295
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• 2005

Two-Phase flow pattern and pressure drop data were obtained for pure refrigerants R134a and R123 and their mixtures as test fluids in a horizontal tube. The flow pattern is observed through tubular sight glasses located at inlet and outlet of the test section. The flow map of Baker developed for air-water two-phase flow at atmospheric pressure failed to predict the observed flow patterns at the higher value of the mass velocity used in the present study. The map of Kattan et al. predicted the data well over the entire region of mass velocity selected in the present study. The measured pressure drop increased with an increase in vapor quality and mass velocity. A new two-phase multiplier was developed from a dimensional analysis of the frictional pressure drop data measured in the present experiment. This new multiplier was found successfully to correlate the frictional pressure drop.

• 한국유체기계학회 논문집
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• 제10권4호
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• pp.55-60
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• 2007

This paper describes an evaluation method of pressure drop in a circular pipe of waste collection piping system. Accurate pressure drop in a piping system is very important to determine the capacity of turbo blower, which is one of the main elements in the system. Three-dimensional Navier-Stokes analysis is introduced to analyze the pressure drop in the piping system. Organic waste is selected and modeled using the result of site survey performed in an apartment area. Evaluation method of pressure drop used In the present numerical simulation is performed in the shortened pipe line prior to the calculation of the real system. Throughout the numerical simulation, pressure drop in a waste pipe is obtained and compared to the value determined by analytical method. The pressure drop obtained by numerical simulation has a good agreement with that of the analytic method. It is noted that present evaluation method is effective to determine a pressure drop in the piping system. Detailed flow characteristics inside the pipe line are also analyzed and discussed.

• 복식문화연구
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• 제20권6호
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• pp.923-936
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• 2012

Apparel companies define their target customers to integrate consumers' needs into their product development processes. The sizing standards play a significant role in ready-to-wear garment business. Consumers' body build and sizes are different according to gender, age, and body type. The consumers' morphological feature of the one geographical area has changed with immigration, aging, and lifestyle change. In this study the way of defining body types in the standard garment sizing systems published in USA., UK, Germany, Japan, and Korea were compared. The results of this study show that most of the systems classified the body types by the index value. The chest-waist drop value was used for men's body type classification. Women's body types were defined by hip proportion. The hip-bust drop value was used for it. German and European garment sizing systems provide a wide range of men's body types. US men's garment sizes are developed for very conservative body type. US women's garment sizing system has had clearly defined women's body types. The Misses body types projected in the US garment sizing system had changed as women's waist girth got bigger compared to the past. In 2011 the US Misses sizes were divided into Curvy Misses size and Straight Misses size by the hip-waist drop value. The Curvy Misses sizes have smaller waist girth and larger hip girth than the Straight Misses sizes.

• 한국생산제조학회지
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• 제22권5호
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• pp.767-773
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• 2013

A high-pressure, high-pressure drop control valve, which transforms the power transfer of a system by reducing the inlet pressure of 345bartothe outlet pressure of 112bar, is a fundamental component in an offshore plant process. With the increasingly growing market share of the maritime industry, this valve has been expected to be a high-value-added product. This study not only analyzes the relation between pressure drop and fluid velocity in a trim by using fluid analysis, but also examines the possibility of cavitation in a valve in addition to the plot for the extension of lifespan. Based on the analysis results, the design and production method of the valve are established, and accordingly, performance evaluation is carried out. It is demonstrated that the pressure drop from 345bar to 112bar is more feasible in the presence of the trim, which can induce a continuous and diminutive pressure drop in order to prevent cavitation in a high-pressure drop control valve. Furthermore, despite the fluid velocity near a seatring being found to be over 30m/s, the lifespan of the valve is determined to be adequate considering the operation condition of a prototype valve of 80%.

• 한국소음진동공학회논문집
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• 제23권4호
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• pp.372-378
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• 2013

An acoustical shape optimization problem is formulated for optimal design of a perforated reactive muffler with offset inlet/outlet. The mean transmission loss value in a target frequency range is maximized for an allowed pressure drop value between an inlet and an outlet. Partitions in the chamber are divided into several sub-partitions, whose lengths are selected as design variables. Each sub-partition has the same number of holes, whose sizes are equal. A finite element model is employed for acoustical and flow analyses. A gradient-based optimization algorithm is used to obtain an optimal muffler. The acoustical and fluidic characteristics of the optimal muffler are compared with those of a reference muffler. Validation experiment is carried out to support the effectiveness of our suggested method.