• Title/Summary/Keyword: working uniform

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A Study on the revised preliminary draft convention on[Int'l] contracts concluded or evidenced by data message (2차 전자계약예비협약초안에 관한 연구)

  • Oh, Se-Chang
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.20
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    • pp.387-421
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    • 2003
  • On the above, a comparison between preliminary draft conventions and comments by the Int'l Chamber of Commerce, contents of preliminary draft convention, problems and alternative are discussed. The conclusions are as follows thereof : The laws of MLEC and MLES made preparation for electronic era of CISG. But electronic circumstances are more changed than the time of regulation of them. Therefore the business world needs a stand-alone convention dealing broadly with the issues of contract formation in electronic commerce. At last, preliminary draft convention delivered a second round. But the base of the instrument was also MLEC and MLES. The revised preliminary draft convention is much amended beyond preliminary draft convention. At its forty-one sessions, the working group reviewed articles 1-11 of the revised preliminary draft convention presented by the secretariat. The remainder was pending until the time of its forty-two sessions. Therefore, on the base of deliberations and decisions of that sessions and them of thirty-six sessions of UNCITRAL, which will be held on comming november, the draft convention which will be prepared by the secretariate, be re-revised preliminary draft convention. According to review of working group on them, preliminary draft convention will officially be draft convention or revise by secretariate. Under these situations, my points of view on draft convention are as follows : As though e-UCP is used carring out side by side with UCP, after e-CISG making in order to adjust CISG to "on" transaction, it is very easy and prompt for business worked to use CISG with e-CISG. This will facilitate ratification of the CISG. For this case, I already presented contents of e-CISG. It is very important for the preliminary draft convention to deal specially with issues related to electronic contracting or to electronic transaction, because according to which way, its contents and scope of application will be different. But the revised draft convention is regretably compromising both them. Consequently, its contents are very confusing and we could not expect its success. If e-CISG will regulate, it is desirable that, if possible, working group has to make the general rule, and the making of useful, practical, affordable rule for electronic commerce, for example Uniform Customs and Practices for Electronic Commerce(e-UEC) in order to solve the specific practical problems, if any, which business currently faces regarding electronic contracting, has to entrust ICC. If working group want to make e-CISG, it is important not to hesitate and take a significant amount of time.

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A Study of Heat Transfer during Freezing Process of Water in a Vertical Cylinder - Comparison of thermal storage performance on the working fluid direction - (수직원통형 축열조내 물의 응고과정시 열전달에 관한 실험적연구 - 작동유체의 유동방향에 따른 열저장성능 비교 -)

  • Heo, K.;Kim, Y.K.;Kim, Y.J.;Kim, J.K.;Yim, C.S.
    • Solar Energy
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    • v.15 no.2
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    • pp.77-90
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    • 1995
  • An effective heat transfer during freezing process was proposed in the vertical cylinder to improve the effectiveness of the heat storage. Vertical cylinder was filled with pure water in order to investigate ice-shape, temperature distribution of the liquid, temperature distribution of the cylinder tube wall, total heat storage per unit mass in the test section under the two experimental conditions; inlet temperature of working fluid is constant($-10^{\circ}C$) and inlet direction of working fluid is either upward flow or downward. Both the mean temperature of the liquid and temperature difference of cylinder tube wall in the upward were lower than those in the downward. In case that the initial temperature of water was $7^{\circ}C$ and $4^{\circ}C$, the shape of ice layer in the upward was more uniform than that in the downward. In case of $1^{\circ}C$, the shape of ice layer is formed by inlet direction of working fluid. Finally, time-varying total heat energy stored in the water in the upward was higher than that in the downward.

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Fabrication of C2H2 Gas Sensors Based on Ag-Doped Hierarchical ZnO Nanostructures and Their Characteristics (Ag가 도핑된 계층적 ZnO 나노구조 기반 C2H2 가스센서의 제작과 그 특성)

  • Lee, Kwan-Woo;Chung, Gwiy-Sang
    • Journal of Sensor Science and Technology
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    • v.23 no.6
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    • pp.397-401
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    • 2014
  • This paper describes the fabrication and characteristics of $C_2H_2$ gas sensor based on Ag-doped hierarchical ZnO nanostructures. In this work, a pure hierarchical ZnO structure was prepared using a simple hydrothermal method, and Ag nanoparticles doped the hierarchical ZnO structure were uniformly synthesized through photochemical route. The synthesized samples were characterized by SEM, TEM, EDS, XRD and PL spectra. Average size of prepared ZnO structures was around $2{\sim}3{\mu}m$ and showed highly uniform. The average size of Ag nanoparticles was 70 nm. The gas sensing properties of as-prepared products were investigated using resistivity-type gas sensors. 5 at% Ag-doped ZnO based sensors exhibited good performances for $C_2H_2$ gas in comparison with the un-doped one. The sensor based on Ag-doped hierarchical ZnO structures had linear response property from 5~1000 ppm of $C_2H_2$ concentration at working temperature of $200^{\circ}C$. The response values with 100 ppm $C_2H_2$ at $200^{\circ}C$ were 10% and 75% for pure and 5 at% Ag-doped hierarchical ZnO nanostructures, respectively. Moreover, the device showed excellent selectivity towards to $C_2H_2$ gas at optimal working temperature of $200^{\circ}C$.

A Comparative Study of the Shielding Performance of Uniforms using Electromagnetic Wave Shielding Materials Currently on the Market for Workers at Korea Railroad Corporation (전자파 고노출 직업군의 근무환경 조사 및 시판 전자기파 차폐소재를 이용한 철도 근무복의 차폐성능 연구)

  • Jung, Hee-Jung;Choi, Hei-Sun;Kim, Eun-Kyong
    • Journal of the Korean Society of Costume
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    • v.60 no.6
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    • pp.23-36
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    • 2010
  • This study set out to develop clothes made of electromagnetic wave shielding materials. Among the various worker groups exposed to electromagnetic waves for long hours, railroad workers were chosen for the study. After selecting the locations they worked, the investigator measured electromagnetic wave on the field. To examine the effects of electromagnetic wave shielding materials, I applied a lining made of electromagnetic wave shielding materials to the existing work clothes. The first experimental clothes had the silver fabric for the lining in the current working clothes, the second experimental clothes had the copper- and nickel-plate polyester placed between the outer and the lining to prevent the corrosive material from contacting the skin, and the third experimental clothes had the silver fabric for the lining and the copper- and nickel-plate polyester between the outer and the lining. The results indicate that even if a fabric is evaluated to shield electromagnetic waves after tests, it cannot completely shield electromagnetic waves emitting from everyday appliances of 60Hz. Therefore, there should be ongoing development and research efforts on fabrics that can shield electromagnetic waves to a certain degree in order to develop working clothes to alleviate fatigue for those who are constantly exposed to electromagnetic waves, relieve their anxiety, offer them psychological stability and thus help them increase job efficiency.

Fabrication of C2H2 Gas Sensors Based on Ag/ZnO-rGO Hybrid Nanostructures and Their Characteristics (Ag/ZnO-rGO 하이브리드 나노구조 기반 C2H2 가스센서의 제작과 그 특성)

  • Lee, Kwan-Woo;Chung, Gwiy-Sang
    • Journal of Sensor Science and Technology
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    • v.24 no.1
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    • pp.41-46
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    • 2015
  • In this work, pure hierarchical ZnO structure was prepared using a simple hydrothermal method, and Ag nanoparticles doped hierarchical ZnO structure was synthesized uniformly through photochemical route. The reduced graphene oxide (rGO) has been synthesized by typical Hummer's method and reduced by hydrazine. Prepared Ag/ZnO nanostructures are uniformly dispersed on the surface of rGO sheets using ultrasonication process. The synthesized samples were characterized by SEM, TEM, EDS, XRD and PL spectra. The average size of prepared ZnO microspheres was around $2{\sim}3{\mu}m$ and showed highly uniform. The average size of doped-Ag nanoparticles was 50 nm and decorated into ZnO/rGO network. The $C_2H_2$ gas sensing properties of as-prepared products were investigated using resistivity-type gas sensor. Ag/ZnO-rGO based sensors exhibited good performances for $C_2H_2$ gas in comparison with the Ag/ZnO. The $C_2H_2$ sensor based on Ag/ZnO-rGO had linear response property from 3~1000 ppm of $C_2H_2$ concentration at working temperature of $200^{\circ}C$. The response values with 100 ppm $C_2H_2$ at $200^{\circ}C$ were 22% and 78% for Ag/ZnO and Ag/ZnO-rGO, respectively. In additions, the sensor still shows high sensitivity and quick response/recovery to $C_2H_2$ under high relative humidity conditions. Moreover, the device shows excellent selectivity towards to $C_2H_2$ gas at optimal working temperature of $200^{\circ}C$.

A Study on the Improvement of Cold Protective Clothing for Mailman (우편배달원 방안복 개선을 위한 연구)

  • Kwon, Myoung-Sook;Seok, Hye-Jung
    • Journal of the Korean Society of Costume
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    • v.57 no.8
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    • pp.14-23
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    • 2007
  • The purpose of this study was to investigate the present condition of cold protective clothing for mailman, to improve its design in movement, fitness, and other functions, and supply basic data for its performance evaluation. The results are as follows : The 46.60% of those questioned did not satisfy current clod protective clothing fer mailman. Especially, they considered dissatisfactory in properties such as waterproof, comfort, activity, and sweat absorption. The newly developed cold protective clothing is two-piece style composed of jacket and pants. Both jacket and pants are composed of inner and outer clothing individually. In both jacket and pants, their outer clothing's material was waterproof, windproof, and breathable shell fabric on which PTFE film laminated and their inner clothing's material was 100% polyester Polar polis to have better insulation property. The jacket has attachable cap which can be used as rain gear and set-in sleeve with stand collar. It also had big outside patch pockets and side seam pockets to ensure enough storage space. The pants have knee pads to give free movement to knees and slant side pockets. Inner clothing of both jacket and pants can be worn during working inside without out clothing. Insulation of the newly developed cold protective clothing was not better than current one except right hand, left hand and left foo. It is considered that is because thickness of material is the most important factor to influence insulation.

Study on the Surface Electric Resistance for Inner COnductive Film in CRT Funnel (브라운관 Funnel Glass 내면의 흑연피막의 표면전기저항에 관한 연구)

  • 김상문;김태옥;신학기
    • Journal of the Korean Ceramic Society
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    • v.35 no.11
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    • pp.1155-1161
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    • 1998
  • We have studyed the surface electric resistiance for inner conductive film consisted of graphite and iron oxide by coating the conductive paint on inner face of 28" wide CRT funnel and have evaluated the working properties of 28" wide CRT according to the surface electric resistiance. We found that the viscosity of paint and the thickness of conductive film became the higher but the surface electric resistiance of con-ductive films was the lower than before in accordance with the increase of solid contents in conductive paint and that the surface condition and the surface electric resistiance of conductive films changed highly ac-cording to the drying conditions also. From these results we could get the uniform thickness and the un-iform film resistance and the optimum working property of selectric propertise in CRT when we used the conductive paint with solid contents 28% and viscosity about 13cps.

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A case study on asymmetric deformation mechanism of the reserved roadway under mining influences and its control techniques

  • Li, Chen;Wu, Zheng;Zhang, Wenlong;Sun, Yanhua;Zhu, Chun;Zhang, Xiaohu
    • Geomechanics and Engineering
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    • v.22 no.5
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    • pp.449-460
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    • 2020
  • The double-lane arrangement model is frequently used in underground coal mines because it is beneficial to improve the mining efficiency of the working face. When the double-lane arrangement is used, the service time of the reserved roadway increases by twice, which causes several difficulties for the maintenance of the roadway. Given the severe non-uniform deformation of the reserved roadway in the Buertai Coal Mine, the stress distribution law in the mining area, the failure characteristics of roadway and the control effect of support resistance (SR) were systematically studied through on-site monitoring, FLAC 3D numerical simulation, mechanical model analysis. The research shows that the deformation and failure of the reserved roadway mainly manifested as asymmetrical roof sag and floor heave in the region behind the working face, and the roof dripping phenomenon occurred in the severe roof sag area. After the coal is mined out, the stress adjustment around goaf will happen to some extent. For example, the magnitude, direction, and confining pressure ratio of the principal stress at different positions will change. Under the influence of high-stress rotation, the plastic zone of the weak surrounding rock is expanded asymmetrically, which finally leads to the asymmetric failure of roadway. The existing roadway support has a limited effect on the control of the stress field and plastic zone, i.e., the anchor cable reinforcement cannot fully control the roadway deformation under given conditions. Based on obtained results, using roadway grouting and advanced hydraulic support during the secondary mining of the panel 22205 is proposed to ensure roadway safety. This study provides a reference for the stability control of roadway with similar geological conditions.

Ingot-Breakdown Design of Tower Flange Material for Offshore Wind Turbine (해상풍력발전용 타워플랜지 소재의 잉고트 파쇄공정설계)

  • Yoo, G.Y.;Kang, N.H.;Kim, J.H.;Hong, J.K.;Lee, C.S.;Lee, J.M.;Kim, N.Y.;Yeom, J.T.
    • Transactions of Materials Processing
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    • v.21 no.7
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    • pp.412-419
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    • 2012
  • The ingot-breakdown scheme of a tower flange material (low-alloy steel) for offshore wind turbine was investigated using finite element (FE) simulations and experimental analyses. Based on compression test results of the low-alloy steel, a deformation processing map was generated using the superposition approach between the dynamic materials model (DMM) and Ziegler's instability criterion. The deformation processing map allowed determination of the optimum process conditions for the tower flange material. Within the FE simulations of the ingot breakdown process, the Cockcroft-Latham criterion, which considers ductile fracture, was used to predict the possibility of forming defects during the hot working process. In general, the critical value for the ductile fracture of steel is 0.74. During the ingot-breakdown under optimum process conditions, the actual tower flange forgings exhibited a relatively uniform shape without any forming defects.

Uniformity Improvement of Micromirror Array for Reliable Working Performance as an Optical Modulator in the Maskless Photolithography System

  • Lee, Kook-Nyung;Kim, Yong-Kweon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.2
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    • pp.132-139
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    • 2001
  • We considered the uniformity of fabricated micromirror arrays by characterizing the fabrication process and calculating the appropriate driving voltages of micromirrors used as virtual photomask in maskless photolithography. The uniformity of the micromirror array in terms of driving voltage and optical characteristics is adversely affected by factors, such as the air gap between the bottom electrode and the mirror plate, the spring shape and the deformation of the mirror plate or torsion spring. The thickness deviation of the photoresist sacrificial layer, the misalignment between mirror plate and bottom electrode, the aluminum deposition condition used to produce the spring and the mirror plate, and initial mirror deflection were identified as key factors. Their importance lies in the fact that they are related to air gap deviations under the mirror plate, asymmetric driving voltages in left and right mirror directions, and the deformation of the Al sring or mirror plate after removal of the sacrificial layer. The plasma ashing conditions used for removing the sacrificial layer also contributed to the deformation of the mirror plate and spring. Driving voltages were calculated for the pixel operation of the micromirror array, and the non-uniform characteristics of fabricated micromirrors were taken into consideration to improve driving performance reliability.

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