• 대한인간공학회지
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• 제30권6호
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• pp.749-755
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• 2011

Objective: The purpose of this study is to assess the reducing effect of workload on developed electro-motion scissors. Methods: To achieve this, we measured the pressure distribution, Joint angle of fingers and JSI(Job Strain Index) for electro-motion scissors and hand-operated scissor in objective assessment and surveyed the uncomfortable degree in subjective assessment. Results: As a result, The peak of pressure in the electro-motion scissors was generally lower than the hand-operated scissors. JSI and overall joint angle of fingers for the electro-motion scissors were remarkably lower than the hand-operated scissors. Also, the subjective uncomfortable degree showed that the uncomfortable point of electro-motion scissors were generally lower than the hand operated scissors. Conclusion: The impact of reducing the work load as well as distributing the pressure around the hand by using electro-motion scissors during grapes pinching was confirmed.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.186-191
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• 2017

An integrated pressure-sensor system was developed using the sensor-conditioning processes, which resulted in the optimum sensitivity of the pressure-sensor through the signal amplification, noise reduction, and level shift. Due to the specified characteristics among the components, such as operation range, the sensor output was generally limited compared to the full scale of the reading when coupled with other parts. Devices fabricated exhibited comparable characteristics with higher pressure sensitivity to that of the pressure sensor without sensor-conditioning process. In this work, the sensor resolution was at least enhanced at least by 25% using the sensor-conditioning processes.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.37-43
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• 2003

The objective of this work is to investigate the effect of swirl, injection pressure and pilot injection on D.I. diesel combustion by using a transparent engine system. The test engine is equipped with common rail injection system to obtain high pressure and to control injection timing and duration. In this study, the combustion analysis and steady flow test were conducted to estimate the heat release rate from in-cylinder pressure. Soot distribution in diffusion flame according to swirl ratio, injection pressure and pilot injection was investigated by using LII technique. As the results, high injection pressure was found to shorten ignition delay as well as enhance peak pressure and heat release rate was greatly affected by injection timing and pilot injection. In addition, the results showed that the period of soot formation corresponded to the diffusion flame.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.217-218
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• 2009

기존에 개발되었던 자기충전 콘크리트의 거푸집 예측 모델에 대해 실험을 통한 검증이 이루어졌다. 실험실에서 거푸집 압력을 모사할 수 있는 실험 장비를 제작하였으며, 자기충전 콘크리트에 대해 실험을 수행하였다. 실험결과로부터 각각의 재료에 대해 모델 교정(Calibration)을 수행하였고, 일반적인 타설 조건을 고려한 거푸집 압력 측정 실험과 교정된 모델로 부터 얻은 해석결과를 비교해 보았다. 모델을 구성하는 파라미터는 재하시간에 따라 특정한 경향을 나타내었으며, 해석 값이 측정된 거푸집 압력의 시간에 따른 변화를 정확히 모사하였다.

• Journal of Mechanical Science and Technology
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• 제17권9호
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• pp.1371-1379
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• 2003

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 22 MPa to 112 MPa using a high pressure injection system (ECD-U2). Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

• Journal of Mechanical Science and Technology
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• 제14권5호
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• pp.562-568
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• 2000

The pressure in a water-entry induced cavity, is analyzed up to the closed cavity (bubble). Water-entry is a highly transient phenomenon, and the evolution of the water-entry cavity must be explained by considering the entry speed, shape of the solid body, atmosphere pressure, and cavity pressure as the primary variables. This work is an extension of the cavity dynamics model recently reported by Lee (l997a). To extend the model for a wide range of entry speeds the cavity pressure is calculated from a one-dimensional quasi-steady flow model. The estimation of the cavity pressure allows us to explain the experimentally observed surface closure phenomena at low entry speeds. Predictions for the time of surface closure are compared with the published experimental data.

• 설비공학논문집
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• 제12권2호
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• pp.181-189
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• 2000

The scroll compressor used for heat pump has a wide range of operation condition. To cover both heating and cooling modes, the operating Pressure ratio ranges from 1.5 to 6.8. Since the scroll compressor, however, is a type of compressor whose pressure ratio is fixed, some loss in the compression work is caused by the operation at the pressure ratio different from the built-in pressure ratio. A way of avoiding this problem is to introduce by-Pass holes in compression chambers, so that the compressed gas of pressure higher than the discharge pressure, yet not reached to the discharge port can be released earlier through the by-Pass holes. In this paper, an optimum Positioning of the by-Pass hole and the effect of the by-pass valve on the compressor performance are studied.

• Current Applied Physics
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• 제18권11호
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• pp.1375-1380
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• 2018

Atmospheric-pressure plasma has a great potential in many applications due to its simplicity rather than low pressure plasmas. In material processing, biomedical applications, and many other applications, the input power, gas flow rate, and the geometry of electrode have been mainly considered and studied as important external parameters of atmospheric-pressure plasma control. Besides, since the atmospheric-pressure plasmas are typically generated in an open air, the relative humidity is difficult to control and can change day by day. Therefore, the relative humidity cannot be ignored for plasmas. Thus, in this work, the atmospheric-pressure plasma jet was characterized by changing relative humidity, and it was found that the increase in electron density and OH radicals are due to Penning ionization between helium metastable and water vapors at higher humidity condition.

• 한국의류학회지
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• 제37권2호
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• pp.235-245
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• 2013

Physiological responses and subjective sensations were evaluated for wearing protective welding clothing in consideration of the work environment for the shipbuilding industry. Experimental clothing was made of oxidant carbon nonwoven fabric (SW2) and oxidant carbon/p-aramid blended fabric (SW4). The values of all items in physiological responses were higher upon wearing oxidant carbon experimental clothing versus wearing oxidant carbon/p-aramid experimental clothing (p<.001). The results of the wearing evaluation in the welding work on-site showed that existing leather protective clothing had a very low satisfaction of permeability, weight sensation and wearing sensation. For the wearing sensation of experimental clothing with SW2, permeability and durability were poor and the pressure and weight sensation satisfaction was very high. In case of SW4, the satisfaction was very high in functional movement, pressure, weight sensation and management aspects; subsequently, the overall wearing satisfaction was very good.

• 한국의류학회지
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• 제40권2호
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• pp.342-352
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• 2016

This study examined the fashion culture of 20-30s working women through clothing norm relationships in the workplace. A literature research was conducted along with qualitative research, in-depth interviews in order to understand the domestic working environment and fashion culture such as lifestyle and consumer culture characteristics of 20-30s working women. The results were: First, it showed that the increased number of members having various inclinations caused subcultures through an increase of women's economic activities and transition to a knowledge-information society in domestic work places that changed into a business casual that recognized employees' autonomy and diversity. Second, in the working place, clothing norms coexist as stipulated by statutes, company rules, and official documents as well as others implied by experiences of sanction against members. Workplace closing norms are classified into norms of exposure that draw attention to clothes and casual clothes. Third, it showed that factors pressuring clothing norms are classified as external pressures and by spontaneous self-censorship that cause conflict and confusion with working women's fashion according to the degree of pressure. Two kinds of pressure by others (or types of departments and members) were observed.