• Title/Summary/Keyword: 2 order system

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Influence upon Machining Accuracy of Micro-Pattern Roll Mold Processed by Temperature Variation (미세 패턴 롤 금형 가공시스템의 온도변화가 가공정밀도에 미치는 영향 연구)

  • Je, T.J.;Park, S.C.;Lee, K.W.;Noh, J.S.;Choi, D.S.;Whang, K.H.
    • Transactions of Materials Processing
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    • v.18 no.2
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    • pp.107-111
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    • 2009
  • Temperature variation happens in micro prism roll mold processing system during machining the prism pattern roll mold using manufacturing optical films of LCD (liquid crystal display). This temperature variation induces pitch errors of the prism patterns. The temperature variation displaces the positions of the diamond cutting tool on the roll which was coated by the copper. In order to prevent the pitch errors, the stabilizing the temperature of machining environment is needed. Therefore, the researching on the temperature variation of the ultra-precision roll mold processing system on the machining of micro prism rot 1 mold is needed. In this paper, the temperature variation of micro prism roll mold processing system is researched, the influence is analyzed, and the study for reducing the pitch errors carried out.

Synthesis of Thin Film Type Cu/ZnO Nanostructure Catalysts for Development of Methanol Micro Reforming System (마이크로 개질기 개발을 위한 박막형 Cu/ZnO 나노구조 촉매 합성)

  • Yeo, Chan Hyuk;Kim, Yeon Su;Im, Yeon Ho
    • Journal of Hydrogen and New Energy
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    • v.24 no.3
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    • pp.193-199
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    • 2013
  • In this work, thin film type Cu/ZnO nanostructure catalysts were fabricated by several synthetic routes in order to maximize the performance of the micro reforming system. For this work, various Cu/ZnO nanostructure catalysts could be synthesized by means of four approaches which are chemical vapor method, wet solution method and their hybrid method. The reforming performance of these as-synthetic catalysts was evaluated as compared to the conventional catalysts. Among the as-synthetic nanostructures, sphere type catalysts with specific surface of $18.6m^2/g$ showed the best performance of hydrogen production rate of 30ml/min at the feed rate of 0.2ml/min. This work will give the first insight on thin film type Cu/ZnO nanostructure catalyst for micro reforming system for hydrogen production of portable electronic systems.

A Study on the Horizontal Ground Source Beat Pump Greenhouse Heating System with Thermal Storage Tank (축열조를 채용한 수평형 지열원 히트펌프 온실 난방 시스템에 관한 연구)

  • Park, Yong-Jung;Kim, Kyoung-Hoon
    • Journal of Energy Engineering
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    • v.15 no.3 s.47
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    • pp.194-201
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    • 2006
  • Greenhouses should be heated during nights and cold days in order to fit growth conditions in greenhouses. Ground source heat pump (GSHP) systems are recognized to be outstanding heating and cooling systems. A horizontal GSHP system with thermal storage tank was installed in greenhouse and investigated the performance characteristics. The reasons for using thermal storage tank were discussed in detail. Thermal storage tank can provide heat for heating load that is larger than GSHP system heating capacity. The results of study showed that the heating coefficient of performance of the heat pump system was 2.69.

The Degumming and Sericin Recovery of the Silk fabric Using the Electrolytic Water(II) (전해수를 이용한 견섬유 정련 및 세리신 회수(II)-분리막에 의한 세리신 농축을 중심으로-)

  • 배기서;이태상;노덕길;홍영기
    • Textile Coloration and Finishing
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    • v.16 no.4
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    • pp.10-18
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    • 2004
  • In this work, Aqueous sericin solution was prepared by degumming process with electrolytic reduction water. Then, the microfiltration and ultrafiltration systems were applied to the concentration of aqueous sericin solution. The objective of this study was to select the optimum operating condition among the different pressure. The permeate flux and rejection ratio were observed with time, pressure, flow rate and concentration. and, the wastewater and permeated water quality values such as pH, BOD, COD, and NH levels were measured. In order to see the influence of electrolytic reduction water, the flux of pure water and electrolytic reduction water by PVDF22(MF) and PS100(UF) membrane was measured. In microfiltration system, the relative flux reduction decreased rapidly to 0.02 in the 30min, as the concentration polarization and gel layer formation were increased. and then the sericin concentration rejection ratio was 40%. In ultrafiltration system, the permeate flux decreased with time and concentration, and increased with the operating pressure and flow rate. Optimal condition in PS100 membrane system for sericin concentration was operating pressure 1.464kgf/$cm^24, operating flow rate $7\ell/min at\; 40^{\circ}C$. At that time, sericin concentration rejection ratio was 83% respectably. The sericin solution was concentrated from 0.1wt% solution to 0.2 wt % solution during about 2 hrs by the UF filteration membrane system.

An Analysis of Service Classification Systems Provided by Major Korean Search Portals (주요 포털들의 서비스 분류체계 비교 분석)

  • Park, So-Yeon
    • Journal of the Korean Society for Library and Information Science
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    • v.44 no.2
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    • pp.241-262
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    • 2010
  • This study aims to perform an evaluation of classification systems provided by major Korean search portals, Naver, Nate, Daum, and Yahoo-Korea. These classification systems are evaluated in terms of the consistency of classification system, logicality of classification system, ease of interface, clarity of category names, order of category and site listing, and hierarchical structure. The results of this study show that each search portal provides separate classification systems for their services. These results imply that it is crucial for search portals to implement a common classification system and a common interface for their services. This study could contribute to the development and improvement of portals' classification systems.

EPC Sensor Network-based Product and Process Traceability System in the Food Supply Chain

  • Chun, Jung-Woo;Oh, Ji-Sung;Rho, Jae-Jueng;Lee, Jung-Wook
    • 한국경영정보학회:학술대회논문집
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    • 2007.06a
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    • pp.184-189
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    • 2007
  • Concerns about food safety continue to rise and under this situation, governments of some countries have reinforced their regulations more strictly for food safety. In order to prevent food safety incidents or, at least to minimize the impact, the preparedness is very important. As a consequence of this, traceability system has become an essential tool for food safety. Recently, it requires more prevention-based food safety control system. One of the most generally used systems for food safety control is Hazard Analysis and Critical Control Point (HACCP). Both traceability and HACCP systems can be integrated through Electronic Product Code (EPC) Sensor Network technologies which have four value propositions. In this paper, we will introduce the concept of product and process traceability system (P2TS) through the integration of three systems to improve food safety management. The final aim is to find out the added values of the P2TS.

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Performance of Local Exhaust Ventilation Systems of Degreasing and Plating Workplaces (일부 탈지세척 및 도금공정 국소배기장치의 성능점검과 개선방안)

  • Han, Don-Hee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.8 no.2
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    • pp.178-185
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    • 1998
  • In order to evaluate and improve the performance of local exhaust ventilation systems for two TCE degreasing (A, B) and two electroplating (C, E) and one acid dipping & plating (D) operations located in Kimhae, the performance test was conducted with trace gases and a thermal anemometer (Kanomax 24-6111, Japan). For the inadequately designed systems, the improvement and redesigns in compliance with recommendation by ACGIH was suggested. The results of performance test for each system are as follows; 1. System of Workplace A was generally well-designed. Actual exhaust air flow rate was in excess of 68% above the recommended standard exhaust air flow rate. 2. System of Workplace B was very well-designed and completely enclosed. 3. All systems of Workplace C including hoods were poorly-designed and actual exhaust air flow rates were insufficient for open tanks. All systems should be upgraded according to ACGIH recommendations. 4. Supply and exhaust air flow rate of push-pull exhaust systems in Workplace D should be greatly increased. The width of flange of dipping tank hood should be increased with the value suggested. 5. System of Workplace E was well-designed. Actual exhaust air flow rate was in excess of 54% above the required.

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The Role of Social Work in Mental Health in a Variable Multicultural Environment

  • SEENIVASAN, R.
    • Journal of Wellbeing Management and Applied Psychology
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    • v.3 no.2
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    • pp.21-26
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    • 2020
  • The purpose of this article is to capture this situation within the changes that take place due to it, inside the Greek society where there is a great need for professional social workers who are able to work targeted and effectively with foreigners, both children and adults, who have or develop mental health problems for the very first time. Over the recent decades the increasing number of migration flows has exerted and continues to exert great pressure on the health system and on the welfare structures of Greece. The bases for the development of a rudimentary reception and integration system that still is in progress have been delayed, while there has been no happy medium, between the enormous pressure that foreigner users of this system put on, and the humanitarian obligation of a well-governed state towards all residents of the country. Straight through everyday clinical practice in the field of intercultural work, social work has the knowledge and techniques for a total management of emerging problems and at the same time provides a value system with an ethical background which approaches refugees and migrants in order to provide quality services, mostly to users of mental health services.

A Driver Space Design of Passenger Vehicle using Forward Kinematics Model (Forward Kinematics 모델을 이용한 자동차 운전공간의 설계)

  • Jeong, Seong-Jae;Park, Min-Yong
    • Journal of the Ergonomics Society of Korea
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    • v.21 no.2
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    • pp.47-58
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    • 2002
  • This research suggested the mathematical model (forward kinematics method) to provide the reference points of driver space more easily and accurately in designing the package layout of vehicle interiors. For this purpose, the lengths of body segments of drivers and various joint angles occurred while were used. The length data between joints for the mathematical model were extracted from $SAFEWORK^{\circed{R}}$ as well as 95th percentile male and 5th percentile female body dimensions were utilized. In addition, the angles of body segments were applied on its diverse values within proper ranges in order to compare them each other. the mathematical model in this study was based on the concept of converting polar coordinate system to Cartesian coordinate system so that reference points of driver space were acquired in Cartesian coordinate system after using the segment lengths of drivers and the joint angles of driving postures as an input of polar coordinate system. It is expected that reference points of driver space obtained from this research are helpful to the study on package layout that is appropriate for physical characteristics of drivers.

Chaos on the Rocking Vibration of Rigid Block Under Two Dimensional Sinusodial Excitation (In the Case of No Sliding Occurrence) (2차원 정현파 가진을 받는 강체블록의 록킹진동에 있어서의 카오스 (미끄럼이 없는 경우에 대하여))

  • 정만용;김정호;김지훈;양광영;양인영
    • Journal of the Korean Society of Safety
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    • v.14 no.2
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    • pp.42-51
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    • 1999
  • This research deals with the non-linearities associated with impact and sliding for the rocking behavior of rigid block subjected to two dimensional excitation of horizontal and vertical direction. The non-linearities examined of impact between block and base: The transition of two governing rocking equations, the abrupt reduction in kinetic energy associated with impact. In this study, the rocking vibration system of two types are considered for several friction condition. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation at impact. The response analysis by non-dimensional rocking equation is carried out for the change of excitation amplitude. The chaos responses were discovered in the wide response region, particularly, in the case of high vertical excitation and their chaos characteristics are examined by Poincare map, power spectra and Lyapunov Exponent. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. Therefore, Poincare map will be a significant material in order to understand chaos of rocking system.

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