• Title/Summary/Keyword: cold environment

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Prevention of the Musculoskeletal Disorders at Upper or Lower Extremities (상지, 하지에서 발생하는 근골격계질환의 예방)

  • Park, Hee-Sok;Lee, Yun-Keun;Yim, Sang-Hyuk
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.4
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    • pp.455-463
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    • 2010
  • Work-related musculoskeletal disorders (WMSDs) are recognized as leading causes of significant human suffering, loss of productivity, and economic burdens on our society. WMSDs are associated with work patterns that include fixed or constrained body positions, continual repetition of movements, force concentrated on small parts of the body, cold environment and vibration. Main effort to protect workers from WMSDs should focus on avoiding repetitive patterns of work through engineering controls which may include mechanization, ergonomic design of tools and equipment, and workplace layout. Where elimination of the risk factors is not practical, administrative controls involving job rotation, job enlargement and enrichment, teamwork should be considered.

The Effect of Supply Angle on Cooling and Heating Performances of Office Space (급기각도가 사무실 공간의 냉방 및 난방 성능에 미치는 영향)

  • Kim, Myo-Sun;Kim, Young-Il;Chung, Kwang-Seop
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.497-501
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    • 2009
  • Effect of angle of supply air on cooling and heating performances of office space is studied by numerical simulation. For a constant air volume(CAV) air-conditioning system, air is supplied vertically($90^{\circ}$) and horizontally($10^{\circ}$). Due to buoyancy, the supply angle affects the performance of cooling and heating. In cooling, since the cold supply air tends to move downward due to its high density, horizontal supply angle is better for uniform temperature distribution. In heating, however, vertical supply angle is preferred for better mean and uniform temperature distribution.

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A Study on the Residential Energy Management of Apartment in the District Heating Area (지역난방 아파트의 난방 관리 실태에 관한 연구)

  • 최남숙
    • Journal of Families and Better Life
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    • v.7 no.1
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    • pp.79-95
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    • 1989
  • Household energy consumption had influenced on the ecological system's environment. Household's exceeding energy consumption requires the development of resources and the risk. Thus this study attempted to find the household heating management, The purpose of this study was to investigate the household's heating management in the area of district heating. The major finding were; 1) The district heating was accepted positively and the benefit of this system was utilized very well in the household. 2) Variances in heating energy consumption was explained by the family size at October, residential period at October and November and the temperature of living room at October, November and December. 3) Compaired to central heating apartment, the low heating expenditure was characterize in the household of 4-5 persons, nuclear family at October, moderated heating control, using extra heating facilities at November. An in the December, that household was that husband has graduated college, temperature of the living room was some cold, and house wives was the full-time homemaker.

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A Study on the Microscopic Precision of Machined Surface according to Variation of Machining Environments in High Speed Endmilling (고속 엔드밀가공에서 가공환경 변화에 따른 가공면의 미시적 정밀도에 관한 연구)

  • Kwon, Dong-Hee;Lee, Jong-Hwan;Hwang, In-Ok;Kang, Myung-Chang;Kim, Jeong-Suk
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.6
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    • pp.50-57
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    • 2006
  • The investigation of microscopic precision in high speed endmilling is necessary for machinability evaluation, and the environmentally conscious machining technology have more important position in recent machining process. The microscopic precision of workpiece is influenced by machining environments variation as cutting fluid type and lubricant method. In this study, the cutting forces according to variation of cooling and lubrication are investigated by specially designed tool dynamometer. And the surface roughness, micro hardness and residual stress are evaluated according to machining environment. The characteristics of damaged layer in environmentally conscious machining and conventional machining using cutting fluid are compared experimentally.

Numerical Simulation of Cold Storage and Preservation of Hanfu Apple

  • Gong, Yuan Juan;Zhang, Yan;Ning, Xiao Feng
    • Journal of Biosystems Engineering
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    • v.41 no.3
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    • pp.184-192
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    • 2016
  • Purpose: To solve the decay phenomenon of Hanfu apples that occurs during storage and obtain the best environmental parameters for preserving Hanfu apples using Fluent. Methods: Preservation storage was designed by analyzing the characteristics of Hanfu-apple storage and the natural environment in northeast China. The boundary conditions and simulation of a preservation model were established. Results: Compared with the initial values, the hardness decreased by $1.95kg/cm^2$, the sugar-acid ratio decreased by 20.43, and weight-loss rate was 3.98%. Conclusion: The results for the temperature field and velocity field of the empty storage were analyzed using Fluent. Hanfu apples can maintain good quality during the period of storage, according to our analysis of the Hanfu-apple hardness, weight loss, and change in the sugar-acid ratio during the 90-day preservation period.

ACSA : An Adaptive Content System Architecture

  • Lee, Jae-Dong;Kim, Jin-Sung
    • Journal of Korea Society of Industrial Information Systems
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    • v.16 no.2
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    • pp.39-47
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    • 2011
  • Adapting content services to the needs of the users requires content adaptation for context and sensibility. Adapting to context may necessitate distinguishing between video delivery to a PC versus a smart phone, while adapting to sensibility may necessitate between video delivery outside, in a quiet environment, or at home, or offering different movie choices on a sunny summer day, a cold winter day or a holiday season. One key area to address in providing adaptive content services is the design of the delivery system architecture of the adaptive content server. This paper describes several alternatives for this architecture, and outlines some additional concerns that must be considered when the chosen architecture is implemented.

LCD Backlight Inverter Drive IC (액정디스플레이 후광 인버터 구동 IC)

  • Jeong, Dong-Youl;Jang, Cheon-Seob;Lee, Seung-Zoo
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2568-2571
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    • 2002
  • A LCD backlight inverter control IC based on the piezoelectric transformer (PZT) for Cold Cathode Fluorescent Lamp (CCFL) lighting is proposed. It is indeed a variable frequency, variable duty (VFVD) controller having dual feedback control loops for achieving both the regulation of lamp current and the maximum efficiency. The PWM controller regulates the lamp current, while the PLL controller tunes the operating frequency to the frequency that the efficiency of the combined LC-PZT resonator becomes maximum. The mixed PLL/PWM control technique lets the backlight inverter operate at the maximum efficiency in spite of the variation of component and environment. The controller features include a protection for an open or broken lamps, and an open lamp regulation.

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High Strength Low Alloy Steel for Sour Service

  • Jung, Hwan Gyo;Kim, Sang Hyun;Yang, Boo Young;Kang, Ki Bong
    • Corrosion Science and Technology
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    • v.7 no.5
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    • pp.288-295
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    • 2008
  • The increase use of natural gas as an energy source has been continuous demand for ever-increasing strength in gas transmission pipeline materials in order to achieve safe and economic transportation of natural gas. In particular, linepipe material for sour gas service primarily needs to have crack resistant property. However, applications of sour linepipes are expanding toward deep water or cold region, which require higher toughness and/or heavier wall thickness as well as higher strength. To improve the crack resistance of linepipe steel in sour environment, low alloy steel are produced by controlled rolling subsequently followed by the accelerated cooling process. This paper summarizes the design concepts for controlling crack resistant property low alloy linepipe steels for sour gas service.

Cold Storage monitoring of Pharmaceutical Products using Near Field Communication, ZigBee and Sensor Cloud (무선 센서 네트워크를 사용하여 물 수준 모니터링)

  • Abel, Avitesh Chandra;Kim, Beom Mu;Jeon, Seong Min;Rajeev, Kumar Piyare;Shiu, Kumar;;;Lee, Sang Il;Oh, Il Hwan;Lee, Sung Ro
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.435-437
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    • 2013
  • This paper proposes a system composed of wireless sensor network and cloud to monitor storage environment of pharmaceutical products. Integration of sensor networks to cloud is an emerging architecture offering the benefits of internet for monitoring to be done easily and remotely from anywhere and anytime and at the same time freeing the sensor network from processing, analysis, computational and storage of sensor data.

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Sex Ratio and Approximate Date of Fertilization of the Subsocial Spider Amaurobius ferox Walckenaer (Araneae: Amaurobiidae)

  • Kim, Kil-Won;Choe, Jae-Chun
    • Journal of Ecology and Environment
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    • v.30 no.3
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    • pp.277-280
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    • 2007
  • Social spiders consistently show highly female-biased sex ratios. However, the sex ratio of subsocial spiders, which have been suggested as an intermediate stage of the evolutionary pathway towards permanent sociality, is generally unknown. We investigated the sex ratio and approximate date of fertilization of the subsocial spider, Amaurobius ferox Walckenaer (Araneae: Amaurobiidae). Investigation over 2 years revealed that sex ratio of A. ferox was consistent across years and averaged 0.49. By early May $(1^{st}{\sim}10^{th})$, 66.6% of female A. ferox observed in the field had already been inseminated, and by late May $(21^{st}{\sim}31^{th})$, 95.4% of females had been inseminated. This result suggests that A. ferox need a long time or cold temperatures to prepare them for reproduction after the developmental attainment of the adult stage.