• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.5
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• pp.658-668
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• 1999

The objective of the present study is to investigate the effect of experimental parameters on the hydrodynamic characteristics in a horizontal tee-type evaporator using R-22. The experimental apparatus consisted of an unheated tee-type test section, a liquid-vapor separator, a preheated, mass flow meters, a plate heat exchanger, pump, and other measurement devices. The experimental parameters were mass flux(500 and 600kg/$m^2$s), inlet quality(0.1~0.3) and separation ratio(0.3~0.7). Absolute pressure at the inlet of the test section was 0.652 MPa. The branch-to-inlet inner diameter ratio was 0.61. Pressure gradient at the branch section was larger than that at the run section at the same separation ratio. Pressure drop per unit length increased at the run section and decreased at the branch section as the separation ratio increased. Pressure drop predicted by the separated flow model agreed with experimental data within -35 to +16%. Generally, predicted values showed similar trend with the data. Mass flow ratio of vapor refrigerant was affected by the inlet quality more than the mass flux.

• Journal of East-West Nursing Research
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• v.16 no.1
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• pp.11-18
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• 2010

Purpose: The aim of this study was to examine the characteristics of hypertension-related nursing intervention programs and their effects on systolic and diastolic blood pressure. Methods: Fifteen studies were selected from four databases (Korean studies, Riss4U, RICHIS, and JKAN) published as of 2009. They were analyzed by meta-analysis method. The selected studies contained a control group with pre-test and post-test design, measured blood pressure as a dependent variable, and used a reported statistical value for blood pressure to measure the size of effects. Results: The hypertension-related nursing intervention programs were relatively effective in lowering both systolic and diastolic blood pressure, although they were more efficient to decrease diastolic pressure. Among the hypertension-related intervention programs, complementary and alternative therapies were more effective in lowering blood pressure compared to lifestyle change intervention. Conclusions: To acquire substantial data of intervention effects, and complementary and alternative therapy, subjects in pre-hypertensive stage, and elderly people, better industrial and scholastic research methods need to be developed for future research. Further studies are needed to establish complementary and alternative therapies. Studies with different group of participants and studies using effective research design are in need as well.

• Geomechanics and Engineering
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• v.32 no.2
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• pp.179-191
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• 2023

To study the influences of tunneling on the earth pressure and ground settlement when the tunnel passes through the adjacent underground retaining structure, 30 two-dimensional model tests were carried out taking into account the ratios of tunnel excavation depth (H) to lateral width (w), excavation width (B), and excavation distance using a custom-made test device and an analogical soil. Tunnel crossing adjacent existing retaining structure (TCE) and tunnel crossing adjacent newly-built retaining structure (TCN) were simulated and the earth pressure variations and ground settlement distribution during excavation were analyzed. For TCE condition, the earth pressure increments, maximum ground settlement and the curvature of the ground settlement curve are negatively related to H/B, but positively related to H/s and H/w. For TCN condition, most trends are consistent with TCE except that the earth pressure increments and the curvature of ground settlement curve are negatively related to H/w. The maximum ground settlement is larger than that observed in tunnel crossing the existing underground structure. This study provides an assessment basis for the design and construction under confined space conditions.

• Journal of the Korean Home Economics Association
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• v.35 no.4
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• pp.159-172
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• 1997

The purpose of this study was to investigate the slacks pattern making on the movement -fitness of the hip region. The experimental items were divided into the 5 lower limb movements(M1-M5) and the 12 revision pattern constructions of slacks. This study was done by clothing pressure test sensory evaluation test and the difference shape-transformation of wearing-slacks. The summarized finding resulted from experiments and investigation are suggested as follows: First by the clothing pressure tested by lower limb movements the clothing pressure score of the rabbit leap movement(M3) was the highest of all lower limb movements and the order of it in the another movement was the sit on knee(M4) the sit on chair(M2) the noble sitting(M5) from the highest to the lowest. And in comparision of clothing pressure tested by revision pattern to cover the extend of crotch-length 20。 inclined back-line construction method (CA4) showed the lowest. And in comparision of clothing pressure tested by revision pattern to cover the extend of crotch-length 20。 inclined back-line construction method (CA4) showed the lowest. And also for a role to cover hip circumference extendign CC4(1/5 hip.1cm longrightarrow linked back -line) method showed the lowest. Second by the sensory evaluation test based on the movement and revision patterns it was found that the functional factor score of the rabbit leap movement was the lowest in all movement however the score of revision patterns were higher than basic pattern. Third by the test to show difference in the shape-transformation of wearing-slacks on chair(M2) also need to be analyzed. The ration of the shape-transformation of the knee region showed the least value in the increased patterns of inclined angle of back-line(CA) and the differential methods of back-line inclined pattern making. But that of the hem-line did not show remarkable difference.

• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.146-153
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• 2006

A performance test of the stainless steel based sintered metal filter was conducted on the low and intermediate level radioactive waste (LILW) vitrification process. The applicability of the metal filter was based on the test results as well. The baseline pressure drop of the metal filter was evaluated similar to the ceramic filter. During the test, when the flow rate of off-gas was $110Nm^{3}/h$, the total baseline pressure drop was shown as $92mmH_{2}O$. The total pressure drop was attributed to the filter media and the residual dust layer and the value of each was $25mmH_{2}O\;and\;67mmH_{2}O$ respectively. The SEM-EDS spectrum and micrograph of the metal filter specimen showed, no corrosion and no physical damage both at the skin membrane and at the support layer. And most of the baseline pressure drop was caused by the deposition of dust on the surface of the membrane. In conclusion, even though the filter exposure time was short at the test, the performance of the stainless steel based metal filter was acceptable for the treatment of LILW vitrification process.

• Journal of Korean Society of Disaster and Security
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• v.6 no.2
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• pp.49-56
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• 2013

In this paper, used by the boundary layer wind tunnel test, have conducted a series of wind tunnel experiments, i.e. test the mean velocity profile regarding the surface roughness, turbulence intensity and power spectrum measured by augmentation device. After that, to provide data relevant for the preliminary design step of tall building hazard fluctuating wind loads may be obtained fluctuating pressure coefficients, fluctuating pressure spectrum, autocorrelation coefficients by the boundary layer wind tunnel test. From the results of experiments, this study can be obtained conclusions as follows. 1. We know the fact that the mean velocity profile and the turbulence intensity are well fitted natural wind flow in the boundary layer wind tunnel. 2. The satisfactory agreement of velocity spectrum can be obtained from the compare of fluctuating power spectrum and Von Karman spectrum. 3. We know the fact that the fluctuating pressure spectrums distributed peak at 0.01 Hz-0.1 Hz in the windward surfaces and at 0.1 Hz in the leeward surfaces. 4. We know the fact that the autocorrelation coefficients distributed stationary random processes with application time of hazard fluctuating wind loads.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.2
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• pp.143-155
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• 2007

The earth pressure acting on a circular shaft wall is smaller than that acting on the wall in plane strain condition due to the three dimensional axi-symmetric arching effect. Accurate estimation of the earth pressure is required for the design of the shaft wall. In this study, the stress model considering the decrease of earth pressure due to the horizontal and vertical arching effect and the influence of shape ratio (shaft height/radius) is proposed. In addition, model test on the sandy soil is conducted and a comparison is made between the stress model and the test results. The comparison shows that the proposed stress model is in agreement with test results; decrease of shape ratio (increase of radius) leads to stress state equal to the plane strain condition and approximate stress distribution is found between stress model and model test results.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.65-76
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• 1996

A screw propeller is usually accepted as a propulsor of many kinds of ships. However, for high speed vessels, screw propeller has large cavitation area on the blades so propeller efficiency is decreased and erosion can be happened. To avoid this problem, supercavitating propeller and waterjet are generally used for high speed vessels. In this paper, we introduced the self-propulsion test procedure which has been developed for high speed vessels in Hyundai Maritime Research Institute. The model ship used in experiment represents catamaran about 5.3 m in length. To minimize the experimental errors, two impellers were driven by a single motor. Thrust was calculated by converting the measured pressure to flow rates at the nozzle exit. The test procedure is composed of resistance test, self propulsion test and analysis. In order to measure the pressure, pressure tabs were installed around the nozzle exit and connected to the pressure sensor by vinyl tube.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.43-55
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• 1996

The purpose of this study was to investigate the slacks pattern making on the movement-fitness of the knee region. The experimental items were divided into the lower limb movement (M1~M5) and slacks pattern designs (4 : basic pattern, in-pleats, side-pleats, seam-line increase). This study was done by clothing pressure test, sensory evaluation test and the difference shape-transformation of wearing-slacks. The summarized finding resulted from experiments and investigation are suggested as follows ; First, the clothing pressure test showed that the order of clothing pressure in the movement was the rabbit leap movement (M3), the sit on knees (M4), the nobleman sitting (M5), the sit on chair (M2) from the highest to the lowest. In the comparison of clothing pressure tested by blocks of lower-limb, center front knee region shows the highest of 300g/cm2. In it by constructional methods, the clothing pressure of in-pleats, side-pleats methods shows lower than basic pattern, hem-line increase methods. Also in comparison of the two methods, in-pleats method shows lower than side-pleats method. Second, by the sensory evaluation test based on the lower-limb movements and constructional methods of slacks, it was found that the functional factor score of the rabbit leap movement was also the waist, hip, knee region was the lowest in all blocks. And in the comparison of constructional methods, in-pleats method was the highest in all methods. Third, in consideration of the difference in the shape-transformation of wearing-slacks on the movement-fitness, pleats pattern design methods showed that the ratio of shape-transformation was lower than basic on seam-line increase methods. But the difference of the side-pleats and in-pleats methods was litle. According to these investigation, the slacks pattern making caused by movement-fitness on the knee region, in-pleats design method was the functional slacks pattern.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.12-17
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• 2017

In this paper, causes of wear on high pressure seals for suspension are analyzed, and the result of reproduction test and verification on improved design are described. First, by performing the observation of worn surfaces and its failure analysis, the primary cause of wear on the seals are analyzed. The result of analysis shows that the main failure mechanism of wear is a fatigue wear, and test criteria for failure reproduction are set up with consideration for frequency condition, surface roughness and pressure. Durability comparison test on the condition of low amplitude and high frequency is carried out. And, it is found that the durability of wear on seals by increasing hardness of cylinder and managing for surface roughness is enhanced.