• International Journal of Human Ecology
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• v.13 no.1
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• pp.117-128
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• 2012

This study compares the net effect of wearing different shoulder/arm armor systems on garment impediment perception and wearer acceptability. Two independent variables in this study were armor systems and shoulder/ arm movements. There were four armor systems of control garment and arm armor systems A, B, and C as well as five types of arm/shoulder movements, (shoulder flexion, should extension, shoulder abduction, shoulder horizontal flexion, and shoulder horizontal extension). Ten male volunteers wearing size medium battle dress uniform (BDU) with recent relevant military experience participated in this study. The volunteers performed shoulder/arm movements (while wearing each armor treatments) and completed the garment impediment perception as well as wearer acceptability scales. The body areas of neck side, shoulder top, and armscye front showed the highest frequency of reported impediments. Resistance to movement and localized pressure were the most frequently mentioned types of impediment. The armor system B had the most areas of impediment, and was rated as more restrictive than the control garment and armor system A for each movement. For wearer acceptability, no significant differences were found between the control garment and armor system A for all eight items; this indicated that subjects did not perceive a difference between wearing the control garment and armor system A. There was a trend for wearer acceptability to decrease from wearing the control garment to armor systems A to C to B.

• The Journal of the Acoustical Society of Korea
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• v.14 no.6
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• pp.13-20
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• 1995

In this paper, the thermoacoustic refrigerating system was implemented and its operation was experimentally verified. The system is composed of several parts ,4 inch midrange speaker, speaker housing, chamber, stack housing, stack of plates, heat exchangers, thin pipe and cavity. The system is filled with He gas at 10 bar and contains T-type thermocouples and condenser microphone for measuring the temperature and pressure inside, respectively. In addition, cooling water is used for protecting speaker from thermal destruction and cooling down the hot heat exchanger. For the experimental verification of the implemented refigerating system, electrical impedance and resonance characteristics were measured. The results showed that it was most efficient to drive the system at 340 Hz. When operated at 340 Hz, $30^\circ{C}$ environments and 50 electical watts, the temperature of the cold region decreased by $16^\circ{C}$. The dissatisfaction mainly comes from the incomplete thermal insulation of the cold region. We also pointed out some guidelines to improve the performance for later study.

• Journal of the Korean Geotechnical Society
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• v.33 no.9
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• pp.61-69
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• 2017

This study presents the experimental results of $CaCO_3$ formation in sand by the Enzyme Induced Carbonate Precipitation (EICP) method. Concentration of $CaCO_3$ with elapsed reaction time is calibrated by standardized procedure by measuring $CO_2$ pressure, and it increases with time towards asymptotic value. Jumunjin sand saturated with EICP solution shows that both shear wave velocity and electrical conductivity sharply increase as the reaction starts to approach to the constant values after 50 hours of reaction time. Urease concentration of 0.5 g/L exhibits 224% higher final shear wave velocity than that of 0.1 g/L. The nucleation models hint that carbonate tends to precipitate not only at grain contacts but also at grain surfaces. Regardless of urease concentration, electrical conductivity and shear wave velocity follow the unique path. The scanning electron microscopic images and X-ray computed tomographic images validate the spatial configuration of produced $CaCO_3$ in soils.

• Journal of the Korea Institute of Building Construction
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• v.21 no.4
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• pp.333-345
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• 2021

Due to the improved living standards and the expectation on higher-quality housing of tenements, complaints on the defects in the buildings are increasing every year. Also, the types of flaws are changing. We surveyed one hundred buildings(9,748 households) in 12 complexes across the country to investigate the shifted types. The number of defects received increased by about 1.6 times compared to 10 years ago, while the categories did not change. The report on the malfunctioning mechanical equipment has increased 1.4 times than ten years ago, and the types of the problem changed. The proportion of general parts(water supplement, drainage, water pressure) has decreased about 25% compared to 10 years ago. This is because the items related to the indoor environment become standardized in apartment housing. Therefore the problems related to those have been increased. As the specialized items applied to the tenement building are showing gradual expansion, the defect reports concerning those will also grow.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.593-604
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• 2021

In this study, a comparative test was conducted on a specially developed elastic waterproof paint and general water-based paint for the purpose of responding to cracks occurring on the outer wall of concrete structures and improving watertightness. Through the comparative experiment, it was confirmed that the watertightness could be improved by securing the crack shielding property, and it was also confirmed that about 10 times more crack responsiveness was secured compared to general water-based paint. In addition, it was confirmed that the adhesion performance of at least 1.3MPa and resistance to a water permeation pressure of 0.1MPa were possible, confirming that stability was secured from a waterproofing perspective.

• Land and Housing Review
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• v.7 no.3
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• pp.131-136
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• 2016

The aim of this study was to improve the performance of hybrid energy harvesting block merge the vibrations and the pressure developed in the previous study. The power generation performance of the energy block improved in this manner was measured and compared with the energy performance of the products previously developed. In previous models, the center has placed a piezoelectric, the two sides had arranged a vibration applying electromagnetic inducing type. Improved model was disposed three in a row of three unit modules for one block. We change the design in the following way. That is, a unit module has been placed the upper piezoelectric body, the lower portion were arranged three electron donation. In laboratory conditions, the power generation performance evaluation results of the improved energy block is as follows. Once when the vibration, power generation was determined to 1.066W. When compared with previous studies, and power generation performance is improved up to 235%. When the vibration in a row 5, power generation was determined to 1.830W. When compared with previous studies, the performance is improved to 177%. The purpose of developing a hybrid energy block is intended to produce electricity by the pressure and vibration when a vehicle passes through the energy block installed in the car park the mouth portion. Electricity produced will try to take advantage of for the purpose of operating a guiding beacon and LED signage in the parking lot entrance. Therefore, it is determined that there is a need in the experiment to compare the performance of the power generation in the field.

• Journal of Korean Home Economics Education Association
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• v.19 no.2
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• pp.103-114
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• 2007

The purpose of this study is to satisfy students in adolescent trends of school uniforms and to provide them with useful material with matching current fashions by analyzing the attitude of students toward uniform transformation in female highschool students and investigating factors influencing on behaviors of uniform transformation. The subjects of this study are 30 students in Daegu with the basic ways of investigating such as depth interview and survey. The results are as follows; First, students agree to wearing school uniforms. As the main reason for wearing school uniforms, students put emphasis on peer pressure. It is also analyzed that the figure of students' body have some influence on the attitude of students toward wearing uniform while students' appearance have no influence on the attitude of students toward wearing uniform. Second, students showed high satisfaction in school uniforms. While students are satisfied with design and color of school uniform, they are not satisfied with practicality, economic efficiency and the quality of textile. Third, the study shows most students have experience of uniform transformation as a result of depth interview about actual condition of uniform transformation. Whereas students usually wear the jacket with its width and length shortened, they tend to lengthen skirt and unstitch pleat of skirt. Fourth, there are many reasons for uniform transformation as a result of depth interview with students. Transformation for satisfying aesthetic desire tops the list, followed by transformation for matching, transformation for peer pressure. As shown by the results above, every school needs to make various efforts to satisfy students, teachers and parents by considering and using students' opinion in order to choose the better school uniforms. In addition, the study related to school uniform transformation need to have more various investigating ways to acquire more authentic results such as expanding the subjects to not only students but also teachers and parents and in-depth comparison between subjects.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.95-101
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• 2014

In this study, an ISM (immersed solid method) was used for investigating the mass flow rate and efficiency of an involute-gear pump featuring very high rotational speed. For considering circulation flow at the gear pump and housing, fluid flow was assumed as turbulent, and the rotational speed of the gear pump increased under the condition of constant pressure at both the inlet and outlet. The efficiency and mass flow rate of the gear pump were studied by varying its rotational speed and the clearance between the gear tip and the housing. In the simulation results, as the rotational speed were increased, the average mass flow rate and efficiency increased. Furthermore, as the clearance between the gear tip and the housing was increased, the average mass flow rate and efficiency decreased. The efficiency was 85.11, 90.94, and 93.62 at rotational speeds of 6,000 rpm, 8,000 rpm, and 10,000 rpm, respectively, under the condition that there was no clearance. In addition, the efficiency was 93.62, 93.29, and 92.74 at clearances of 0 m, 0.00001 m, and 0.00003 m respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1307-1313
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• 2011

The mechanical limited slip differential (LSD) in vehicles is being replaced by the electromagnetic LSD because of its fast response and better active control characteristics. The coil housing made of STS 304 is one of the most important parts in the solenoid assembly of the electromagnetic LSD. High geometrical accuracy is a prerequisite for the manufacture of such coil housings, but precision machining is difficult because of the use of STS 304 thin plate and the variance in machining variables. The aim of this study is to optimize the mean and variance of the shape accuracy in the coil housing by finding a robust solution for the machining process conditions. The mean and standard deviation of the jaw contact pressure, cutting speed, and feed rate are considered to be the major parameters for minimizing the geometrical mean and variance. The response surface model based on the second-order Taylor series is combined together to minimize the mean and variance of the shape accuracy of the coil housing.

• Land and Housing Review
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• v.5 no.4
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• pp.325-332
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• 2014

The purpose of this study was to measure the airtightness and Air-Flow Performance for 7th house of small apartment houses adopted window frame-type natural ventilation. All window and living room door is provide with window frame-type natural ventilation, and there is provide with manual controller. As the object of measurement, the 6th type small apartment houses with area of $33m^2$ to $51m^2$ was selected. airtightness performance was measured at the front door using Blower door system. We measured ventilation rate per hour on 50Pa pressure different between inside and outside by the 1st to 6th cases. As a result, when the natural ventilation frame was closed, average amounts are shown as the ventilation rate per hour were 2.27ACH (CASE1). and the result is similar to general apartment house (1.65~4.28ACH). When the natural ventilation frame was open, average amounts are shown as the ventilation rate per hour were 5.87ACH (CASE6). In addition, that's a 3.6ACH increased more than CASE1.