• Title/Summary/Keyword: Leg Assembly

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A FLOW AND PRESSURE DISTRIBUTION OF APR+ REACTOR UNDER THE 4-PUMP RUNNING CONDITIONS WITH A BALANCED FLOW RATE

  • Euh, D.J.;Kim, K.H.;Youn, Y.J.;Bae, J.H.;Chu, I.C.;Kim, J.T.;Kang, H.S.;Choi, H.S.;Lee, S.T.;Kwon, T.S.
    • Nuclear Engineering and Technology
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    • v.44 no.7
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    • pp.735-744
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    • 2012
  • In order to quantify the flow distribution characteristics of APR+ reactor, a test was performed on a test facility, ACOP ($\underline{A}$PR+ $\underline{C}$ore Flow & $\underline{P}$ressure Test Facility), having a length scale of 1/5 referring to the prototype plant. The major parameters are core inlet flow and outlet pressure distribution and sectional pressure drops along the major flow path inside reactor vessel. To preserve the flow characteristics of prototype plant, the test facility was designed based on a preservation of major flow path geometry. An Euler number is considered as primary dimensionless parameter, which is conserved with a 1/40.9 of Reynolds number scaling ratio. ACOP simplifies each fuel assembly into a hydraulic simulator having the same axial flow resistance and lateral cross flow characteristics. In order to supply boundary condition to estimate thermal margins of the reactor, the distribution of inlet core flow and core exit pressure were measured in each of 257 fuel assembly simulators. In total, 584 points of static pressure and differential pressures were measured with a limited number of differential pressure transmitters by developing a sequential operation system of valves. In the current study, reactor flow characteristics under the balanced four-cold leg flow conditions at each of the cold legs were quantified, which is a part of the test matrix composing the APR+ flow distribution test program. The final identification of the reactor flow distribution was obtained by ensemble averaging 15 independent test data. The details of the design of the test facility, experiment, and data analysis are included in the current paper.

The Liability and Limitation of Liability Regime in the Rotterdam Rules (로테르담 규칙상의 운송인의 책임)

  • Lee, Shie-Hwan
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.42
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    • pp.189-210
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    • 2009
  • The United Nations General Assembly adopted the United Nations Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea(hereinafter referred to as "The Rotterdam Rules") on 11 December 2008. Rotterdam Rules aims to create a contemporary and uniform law providing for modern door-to-door container transport including an international sea leg. but not limited to port-to port carriage of goods. The structure of the liability regime in Rotterdam Rules are globally close to that of the Hague-Visby Rule even though it differs from that of the Hague-Visby Rules in some significant aspects. The Rotterdam Rules are very long. Therefore the Rotterdam Rules will be difficult to understand for even the skilled ship operator or owner or charterer or shipper or consignee or receiver because they are so complicated. This paper only seeks to highlight the salient features of the liability and limitation of liability regime under the Rotterdam Rules. It is expected that the harmonization and modernization of the international legal regime. coupled with the bold attempt to balance the carrier and cargo interests should lead to an overall reduction in transaction costs. increased predictability and greater commercial confidence for international business transactions.

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The Effects of Customized Insoles on the Post-Work Discomfort and Pain (맞춤형 인솔이 산업체 근로자의 작업 후 신체불편지수와 통증에 미치는 영향)

  • Kim, Duck-Hwa;Jung, Do-Young;Kwon, Oh-Yun
    • Physical Therapy Korea
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    • v.14 no.2
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    • pp.85-90
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    • 2007
  • In many manufacturing occupations, industrial workers reported foot or lower leg problems such as discomfort, pain or orthopedic deformities. This study investigated the effects of two different working conditions upon assembly worker's perception of discomfort and foot pain associated with various body parts. Twenty-three male volunteers performed work in the factory. Ergonomic intervention has been to modify the flooring in an attempt to alleviate the problems associated with constrained standing and walking work. The worker's standing conditions consisted of standing on a hard floor while wearing shoe insoles. Questions were asked regarding body discomfort and foot pain. Significant differences in body discomfort and foot pain were found when comparing the overall effects of wearing shoe insoles on a hard floor (p<.05). This investigation indicated that shoe insoles reduced body discomfort and foot pain (p<.05).

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The usage of convergency technology for ROGA algorithm application on step walking of biped robot (이족 로봇의 계단 보행에서 Real-Coded Genetic Algorithm 의 융합 기술의 사용)

  • Lee, Jeong-Ick
    • Journal of the Korea Convergence Society
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    • v.11 no.5
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    • pp.175-182
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    • 2020
  • The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.