• Journal of Fashion Business
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• v.5 no.2
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• pp.49-65
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• 2001

This thesis aims to reveal the unsatisfactory unfitting factors in the tight collars of adult males' dress shirts for the purpose of improving neck-collar fitness. For this study, nine adult males were chosen as the subjects. When the subjects erected their necks upright, the researcher conducted an experiment, using the direct anthropometrical measuring method and the gypsum method by turns, in order to understand neck shapes by way of right-neck lateral flection, left-neck lateral flection, neck flection, neck extension, right neck rotation, and left neck rotation. And then, the propriety of allowances from body surface alteration was verified by analyses through the measurement of wearing comfortableness and clothing pressure in two sorts of ready-made dress shirts, which had different allowances. The consequences of this study are as follows: 1. In length alteration to movement, a decrease was found in the opposite (and an increase in the identical) directions of right-neck lateral flection, left-neck lateral flection, and neck flection movements. Also, when the subjects shook their heads, an increase was seen by 0.42$\sim$0.63cm in neck girth, 0.31$\sim$1.12cm in 3cm-above-the-neck base girth, and 1.16cm in neck extension of 3cm-above-the-neck base girth. 2. As a result of the drafts of surface measurement, the alteration ratios of dimensions and vertical length dropped in the identical directions of the movement, but grew in the opposite directions. A reverse change was shown in horizontal length. The rough widening gaps for making drafts were 0.7cm in front left and right, and 0.2cm in back left and right of 3cm-above-the-neck base girth. On the whole, the space was about 1.8cm, while there was no significant variation between the upright stationary test and the movement test. 3. There were important differences between the two kinds of ready-made dress shirts (Type A: 1cm allowance in neck girth; Type B: 2cm allowance) in clothing pressure and wearing comfortableness. That is, Type A had higher pressure and more uncomfortable sense of wearing. In other words, as clothing pressure and wearing comfortableness are negatively related to each other, Type A's greater clothing pressure led to worse wearing comfortableness.

• Journal of Welding and Joining
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• v.4 no.3
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• pp.32-42
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• 1986

In this study, the influence of carbon equivalents on friction welds of dissimilar steels was investigated. Four types of carbon steels with 10mm diameter were welded to a high-speed tool steel SKH 9. Main experimental results could be summarized as follows (1) Under constant friction pressure, the friction time increased almost linearly with the increasing burn-off length, while the forge length decreased almost linearly. (2) The maximum hardness in carbon steels increased almost linearly with the increasing carbon equivalent, but was much lower than that in the high speed steel. (3) After quenching and tempering of dissimilar steel friction welds, the hardness in carbon steel weldments became similar as that in the base metal, while the hardness in SKH 9 weld was still higher that of the base metal. (4) Relative movement in the friction phae occurred not at the interface of the weldments, but in the high speed steed steel near the interface. (5) For considered material combinations and welding parameters, most of fractures in tension and twisting tests occurred in the base metal. And welds with so high strength could produced in a wide range of welding parameters.

• Journal of the Korean Professional Engineers Association
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• v.34 no.2
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• pp.37-41
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• 2001

In recent days, welding technology developed in various field of industry, a ship, a building, a structure, a high pressure vessel ect. A welding structure should be base on a safety Welding engineers and welding technicians have a problem in acquiring welding technology, because young people avoid state of the art, beginning their careers In this field. The optimum welding state depends upon the most welding condition, mechanical properties of the base metal, welding processes and arc stability. Base on these fact, the suitable parameters of welding condition can be found through various welding experiments. Therefore, it Is very Important for welding professional engineers to take an active role In advancing new welding technology

• Journal of the Korean Society of Safety
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• v.22 no.2 s.80
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• pp.22-27
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• 2007

To assess a creep life of elevated temperature plant components, inspections and analysis are usually focused on the critical locations. In this study, stress analysis of a weld region in branch part of Y-piece was conducted by using a three-dimensional finite element analysis. The stresses at the inner and outer surface in the weld part were estimated by using elastic and elastic-creep analysis. For the elastic-creep analysis two kinds of elastic-creep analysis was conducted. The one was assumed that base and weld material properties were same and the other was that material properties were different between base and weld metal. The material properties of base and weld metal were used from reference data. The results showed the stress relaxation level and its location. The result stresses are also compared with elastic stresses.

• Wind and Structures
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• v.7 no.3
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• pp.203-214
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• 2004

This paper describes a method for developing a multi-degree-of freedom aero-elasto-plastic model of a base-isolated mid-rise building. The horizontal stiffness of isolators is modeled by several tension springs and the vertical support is performed by air pressure from a compressor. A lead damper and a steel damper are modeled by a U-shaped lead line and an aluminum line. With this model, the frequency ratio of torsional vibration to sway vibration, and plastic displacements of isolation materials can be changed easily when needed. The results of isolation material tests and free vibration tests show that this model provides the object performance. The peak displacement factors are about 4.5 regardless of wind speed in wind tunnel tests, but their gust response factor decreases with increment of wind speed.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.333-334
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• 1989

Electrically active part of the piezoelectric sound element is a ceramic thin circular disk cemented to a metal base plate (using a type of thermosetting epoxy). The active part is a thin lead zirconate titanate disk (PZT). The piezoelectric sound element is so dimensioned that its basic resonance frequency is approximately if the center of the audible frequency band: This frequency is mainly determined by the geometry and the sort of the metal base plate materials. In this study, four kinds of PZT ceramic and two classes of thin metal base plate were prepared. It is observed that dielectric and pizoelectric properties relate to acoustical properties (particularly sound pressure level).

• Journal of Welding and Joining
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• v.15 no.4
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• pp.90-98
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• 1997

A copper-tungsten sintered alloy(Cu-W) has been friction welded to a tough pitch copper in order to investigate the effect of friction pressure on bonding strength and a charicteristic of fracture. The tensile strength of the friction welded joint was increased up to 90% of the Cu base metal under the condition of friction time 1.2 sec, friction pressure 4.5kgf/$\textrm{mm}^2$ and upset pressure 10kgf/$\textrm{mm}^2$. From the results of fracture surface analysis, the increase of friction pressure could remarkably decrease the force and the time to be normally acted on weld interface. The W particles which were included in the plastic zone of Cu side could induce fracture adjacent to the weld interface because their existance in Cu induces a decrease in available section area and an increase in notch effect. Therefore, the tensile strength was decreased at high friction pressure (6kgf/$\textrm{mm}^2$) because the destruction of W was increased by an increase in mechanical force and crack was formed at weld interface.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.15-22
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• 2011

The chemistry factor and RTPTS margin for domestic reactor pressure vessel materials were analyzed by using the surveillance data which have been obtained from 8 nuclear power plants in Korea. The surveillance data have been used to assess the integrity of the pressure vessel under the pressurized thermal shock (PTS) event. The chemistry factor, which is determined by the Cu and Ni contents of vessel materials, is considered a proper tool to assess the $RT_{PTS}$. The chemistry factors, which were obtained from the surveillance data of domestic reactor pressure vessels, were investigated and compared with those of Regulatory Guide 1.99 in this study. Regressions for ${\Delta}RT_{NDT}$ were performed to expect the chemistry factor as a function of Cu and Ni, and to estimate $RT_{PTS}$ margin. The margin analysis was performed by comparing the regression graphs and standard deviations with those of Regulatory Guide 1.99. The standard deviations calculated by using the domestic surveillance data for base metal and welds are almost same as the standard deviations which are suggested on Regulatory Guide 1.99, Rev.2.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.3
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• pp.127-133
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• 2017

Performance analysis has been carried out on a high side scroll compressor that had a fixed scroll equipped with a circular oil groove on its thrust surface. Oil was supplied to the oil groove through an intermittent opening from a high pressure oil reservoir formed inside the orbiting scroll hub. Oil in the groove was then delivered to both suction and back pressure chambers by pressure differentials and viscous pumping action of the orbiting scroll base plate. Mathematical modeling of this oil groove system was incorporated into a main compressor performance simulation program for an optimum oil groove design. The study findings were as follows. Pressure in the oil groove can be controlled by changing its configuration and the oil passage area. With an enlarged oil passage, the pressure in the oil groove heightens due to an increased flow rate, but the pressure elevation in the back pressure chamber is small, resulting in reduced friction loss at the thrust surface between the two scrolls. On the other hand, by increasing the oil passage area, the oil content in the refrigerant flow increases. Considering all these factors, the energy efficiency ratio could be improved by about 3.6% under the ARI condition by an optimal oil groove design.

• Journal of Biomedical Engineering Research
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• v.40 no.4
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• pp.132-136
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• 2019

This study proposes an auto-titrating algorithm for auto-titrating positive airway pressure (APAP). The process of the proposed algorithm is as follows. First, sleep apnea-hypopnea and snoring events were detected using nasal pressure. Second, APAP base pressure and SDB events were used for automatic titration of optimal pressure. And, auto-titrating algorithm is built into M3 (MEK-ICS CO. Ltd., Republic of Korea) for evaluation. The detection results of SDB showed mean sensitivity (Sen.) and positive predictive value (PPV.) of 85.7% and 87.8%, respectively. The mean pressure and apnea-hypopnea index (AHI) of auto-titrating algorithm showed $13.0{\pm}5.2cmH_2O$ and $3.0{\pm}2.4$ events/h, respectively. And, paired t-test was conducted to verify whether the performance of our algorithm has no significant difference with AutoSet S9 (p>0.05). These results represent better or comparable outcomes compared to those of previous APAP devices.