• Title/Summary/Keyword: reference energy

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A Numerical Study on the Flow Uniformity according to Chamber Shapes Used for Test of the Semi-Conductor Chip (반도체 칩 테스트용 챔버 형상에 따른 유동 균일성에 대한 수치적 연구)

  • LEE, DAEGYU;MA, SANG-BUM;KIM, SUNG;KIM, JEONG-YEOL;KANG, CHAEDONG;KIM, JIN-HYUK
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.5
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    • pp.480-488
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    • 2020
  • This study was conducted to improve the flow uniformity inside the chip tester through changing the flow path formation according to the inlet and outlet position of chamber. The internal flow and velocity distributions of the modified chamber models (Cases 1-3) were compared with the reference chamber model through three-dimensional Reynolds-averaged Navier-Stokes equations with k-ε turbulence model. The modified chamber models showed the superior flow uniformity characteristics compared to the reference chamber model. To investigate the flow uniformity in the chip tester, the standard deviation of the velocity was defined and compared. Through the internal flow analysis and assesment of the standard deviation, Case 2 among the test cases including the reference model showed the best flow uniformity generally.

Compensation for Photovoltaic Generation Fluctuation by Use of Pump System with Consideration for Water Demand

  • Imanaka, Masaki;Sasamoto, Hideki;Baba, Jumpei;Higa, Naoto;Shimabuku, Masanori;Kamizato, Ryota
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1304-1310
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    • 2015
  • In remote islands, due to expense of existing generation systems, installation of photovoltaic cells (PVs) and wind turbines has a chance of reducing generation costs. However, in island power systems, even short-term power fluctuations change the frequency of grids because of their small inertia constant. In order to compensate power fluctuations, the authors proposed the power consumption control of pumps which send water to tanks. The power control doesn’t affect water users’ convenience as long as tanks hold water. Based on experimental characteristics of a pump system, this paper shows methods to determine reference power consumption of the system with compensation for short-term PV fluctuations while satisfying water demand. One method uses a PI controller and the other method calculates reference power consumption from water flow reference. Simulations with a PV and a pump system are carried out to find optimum parameters and to compare the methods. Results show that both PI control method and water flow calculation method are useful for satisfying the water demand constraint. The water demand constraint has a little impact to suppression of the short-term power fluctuation in this condition.

Energy-Efficient Reference Walking Trajectory Generation Using Allowable ZMP (Zero Moment Point) Region for Biped Robots (2족 보행 로봇을 위한 허용 ZMP (Zero Moment Point) 영역의 활용을 통한 에너지 효율적인 기준 보행 궤적 생성)

  • Shin, Hyeok-Ki;Kim, Byung-Kook
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.10
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    • pp.1029-1036
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    • 2011
  • An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

Setting of Adiponectin Reference Range and Clinical Significance of investigation (Adiponectin Reference Range설정과 임상적 의의 고찰)

  • Kim, Yong-Ha;Oh, Choon-Soon;Lee, Ann-Na
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.1
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    • pp.82-87
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    • 2008
  • Purpose: The Bio-energy metabolism control hormone by Adipocytokine is composed with Leptin, Adiponectin, resistin, TNF-a, IL-6. Adiponectin become known to participating in Insulin sensitivity exasperation, Fat metabolism accomodation and inducing metabolic disease such as diabetes mellitus, arteriosclerosis, hyperlipemia. When we accomplished the test with purpose of Research, we observed significance with a result of test related to diabetes mellitus with reference setting by way of suggestion. Methods: Result of normal group (n=100) which is committed in the SCL from September 2006 to December 2006 and result of control group (n=50) relationship examination item that is decided diabetes measures themselves against each other. Also, we measured the normal group against the control group for the reference range of adiponectin. Results: Result in normal group (n=100) appeared by Glucose (reference 70~120 mg/dl) Mean and the SD 96.99 (${\pm}24.35$), HbA1c (reference 4.0~6.0%) Mean and the SD 5.64 (${\pm}0.90$), Insulin (reference 2.0~25.0 uIU/ml) Mean and the SD 7.80 (${\pm}4.42$), the Adiponectin the Mean and the SD 9,861.23 (${\pm}4,977.0$). Result in control group(n=50) appeared by Glucose (reference 70-120 mg/dl) Mean and the SD 224.95 (5.30), the HbA1c (reference 4.0~6.0%) Mean and the SD 8.22 (1.63), Insulin (reference 2.0~25.0 uIU/ml) Mean and the SD 17.02 (3.01), C-peptide (reference 0.48~3.30 ng/ml) Mean and the SD 7.92 (${\pm}7.40$), the Adiponectin Mean and the SD 18,110.03 (${\pm}12,843.29$). Conclusions: Therefore, it seems that test results are significant and we consider that it can be apply to useful diagnosis of diabetes mellitus, arteriosclerosis, hyperlipemia patients throughout the reference range setting of Adiponectin, Leptin is one of the Bio-energy metabolism control hormone.

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Calculation of Potential Energy Curves of Excited States of Molecular Hydrogen by Multi-Reference Configuration-interaction Method

  • Lee, Chun-Woo;Gim, Yeongrok;Choi, Tae Hoon
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1771-1778
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    • 2013
  • For the excited states of a hydrogen molecule up to n = 3 active spaces, potential energy curves (PECs) are obtained for values of the internuclear distance R in the interval [0.5, 10] a.u. within an accuracy of $1{\times}10^{-4}$ a.u. (Hartree) compared to the accurate PECs of Kolos, Wolniewicz, and their collaborators by using the multi-reference configuration-interaction method and Kaufmann's Rydberg basis functions. It is found that the accuracy of the PECs can be further improved beyond $1{\times}10^{-4}$ a.u. for that R interval by including the Rydberg basis functions with angular momentum quantum numbers higher than l = 4.

Korean Reference Disposal System for High-level Radioactive Wastes

  • Choi Heui-Joo;Choi Jongwon;Lee Jong Youl
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.11b
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    • pp.225-235
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    • 2005
  • This paper outlined the status of the development of Korean Reference Disposal (KRS­1) system for high-level radioactive wastes. The repository concept was based on the engineering barrier system which KAERI has developed through a long-term research and development program. The design requirements were prepared for the conceptual design of the repository. The amount of PWR and CANDU spent fuels were projected with the current nuclear power plan. The disposal rates of PWR and CANDU spent fuels were analyzed. The reference geologic characteristics including classification of fracture zones were set for the KRS. The disposal concepts and the layout of the repository were described.

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Intercomparison of KAERI Reference Photon Radiation Fields

  • S.Y.Chang;J.C.MacDonald;M.K.Murphy;Kim, B.H.;Lee, K.C.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05d
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    • pp.34-39
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    • 1996
  • A series of measurements was peformed between KAERI and PNNL, U.S.A at KAERI secondary calibration laboratory to intercompare and verify the KAERI reference photon radiation fields by using air equivalent plastic walled ionization chambers, Different ionization chambers of two laboratories were used to determine the air kerma rate, free-in-air, at reference positions in the KAERI photon radiation fields, As the results, the agreement in the cross measurements between two laboratories was found to be within less than ${\pm}$ 3 %. This degree of consistency was considered to be encouraging, because each laboratory maintains independently its calibration traceablity with its national primary standard

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Process Reference Model for modeling BIM/GIS-based Energy Information (BIM/GIS 기반 에너지 정보 모델링을 위한 프로세스 참조 모델)

  • Kang, Tae-Wook;Ryu, Han-Soo;Ko, Jeong-Lim;Choi, Hyun-Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2791-2798
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    • 2015
  • The purpose of this study is to suggest Process Reference Model(PRM) for BIM/GIS-based Energy Information Modeling(BG-EIM) efficiently. Through the study, the detail process and consideration were derived to design EIM for the purpose of energy analysis depending on specific use-cases. To do this, we survey related studies and analyze the detailed EIM process. By using the results, BIM/GIS-based energy analysis consideration is defined and BG-EIM PRM is proposed.