• Title/Summary/Keyword: Inter-phase distribution

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Uniform Current Distribution among Conductor Layers in HTS Cables Using Inter-Phase Transformers (Inter-Phase Transformers를 이용한 고온 초전도 케이블의 층간 전류 등분배 방안)

  • 최용선;황시돌;현옥배;임성우;박인규
    • Progress in Superconductivity
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    • v.5 no.2
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    • pp.144-148
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    • 2004
  • Uniform current distribution among conductor layers in HTS cables using IPTs (inter-phase transformers) was investigated. Conventional methods for current distribution, in which resistors are inserted to conductor layers, causes additional loss. In contrast, IPTs, which use magnetic coupling, make it possible that the current in parallel circuits is distributed uniformly with any load, and minimize the loss. In this study, IPTs were designed and fabricated for examination of uniform current distribution in the conductor layers of HTS cables. The ITP was designed through calculation of its impedance that can cancel the inductance of the conduction layers. The experimental setup consisted of four IPTs and four inductors that simulate the conductor layer inductance. Each layer was designed to feed 10 A. We examined the behavior of current distribution with IPTs for various layer inductances.

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A method for uniform current distribution of HTS cable using Inter-Phase Transformers (Inter-Phase Transformers를 이용한 고온초전도 케이블의 층간 전류 등분배 방안)

  • Choi, Yong-Sun;Yim, Seong-Woo;Sim, Jung-Wook;Hwang, Si-Dole;Park, In-Gyu
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.973-975
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    • 2003
  • Uniform current distribution among conductor layers in HTS cables using IPTS (inter-phase transformers) was proposed. Conventional methods for current distribution, in which resistors are inserted to conductor layers, causes additional loss. In contrast, IPTS, which use magnetic coupling, make it possible that the current in parallel circuits is distributed uniformly with any load, and minimize the loss. In this study, IPTS were designed and fabricated for examination of uniform current distribution in the conductor layers of HTS cables. The ITP was designed through calculation of its impedance that can cancel the inductance of the conduction layers.

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Development of Inter Turn Short Fault Model of IPM Motor (IPM모터의 턴쇼트 고장모델에 관한 연구)

  • Gu, Bon-Gwan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.4
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    • pp.305-312
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    • 2015
  • In this study, inter-turn short fault models of interior permanent magnet synchronous motors (IPMSM) are developed by adding saliency modeling to surface-mounted permanent magnet motor models. The saliency model is obtained using the deformed flux models based on both fault-winding flux information and inductance variations caused by cross-flux linkages that depend on the distribution of the same phase windings. By assuming the balanced three-phase current injection, we obtain the positive and negative sequence voltages and the fault current in the positive and the negative synchronous reference frames. The output torque model is developed by adding the magnet and the reluctance torque, which are derived from the developed models. To verify the proposed IPMSM model with an inter-turn short fault, finite element method-based simulation and experimental measurement results are presented.

Clinical Pharmacogenomics of Drug Metabolizing Enzymes and its Clinical Application (약물대사효소의 유전적 다형성 및 임상적 응용)

  • Kim, Kyung-Im;Kim, Seung-Hee;Park, Ji-Eun;Chae, Han-Jung;Choi, Ji-Sun;Shin, Wan-Gyun;Son, In-Ja;Oh, Jung-Mi
    • Korean Journal of Clinical Pharmacy
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    • v.16 no.2
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    • pp.155-164
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    • 2006
  • Great inter-variability in drug response and adverse drug reactions is related to inter-variability of drug bioavailability, drug interaction and patient's disease and physyological state that cause change in absorption, distribution, metabolism and excretion of drugs. However, these alone do not sufficiently predict and explain inter-variability in drug response. In recent studies, it is reported that inter-variability in drug response and adverse drug reactions may largely resulted from genetically determined differences in drug absoption, distribution, metabolism and drug target proteins. Especially, the major human drug-metabolizing enzymes such as CYP450, N-acetyl tranferase, thiopurine S-methyl transferase, glutathione S-transferase are identified as the major gene variants that cause inter-individual variability in drug's response and adverse drug reactions. These variations may have most significant implications for those drugs that have narrow therapeutic index and serious adverse drug reactions. Therefore, the genetic variation such as polymorphisms in drug metabolizing enzymes can affect the response of individuals to drugs that are used in the treatment of depression, psychosis, cancer, cardiovascular disorders, ulcer and gastrointestinal disorders, pain and epilepsy, among others. This review describes the pharmacogenomics of the drug metabolizing enzymes associated with the drug response and its clinical applications.

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In situ measurement-based partitioning behavior of perfluoroalkyl acids in the atmosphere

  • Kim, Seung-Kyu;Li, Donghao;Kannan, Kurunthachalam
    • Environmental Engineering Research
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    • v.25 no.3
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    • pp.281-289
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    • 2020
  • Environmental fate of ionizable organic pollutants such as perfluoroalkyl acids (PFAAs) are of increasing interest but has not been well understood because of uncertain values for parameters related with atmospheric interphase partitioning behavior. In the present study, not only the values for air-water partition coefficient (KAW) and dissociation constant (pKa) of PFAAs were induced by adjusting to in situ measurements of air-water distribution coefficient between vapor phase and rainwater but also gas-particle partition coefficients were also estimated using three-phase partitioning model of ionizable organic pollutants, in situ measurements of PFAAs in aerosol and air vapor phase, and obtained parameter values. The pKa values of PFAAs we obtained were close to the minimum values suggested in literature except for perfluorooctane sulfonic acids, and COSMOtherm-modeled KAW values were assessed to more appropriate among suggested values. When applying parameter values we obtained, it was predicted that air particle-associated fate and transport of PFAAs could be negligible and PFAAs could distribute ubiquitously along the transection from urban to rural region by pH-dependent phase transfer in air. Our study is expected to have some implications in prediction of the environmental redistribution of other ionizable organic compounds.

A Study on Optimal Release Time for Software Systems based on Generalized Gamma Distribution (일반화 감마분포에 근거한 소프트웨어 최적방출시기에 관한 비교 연구)

  • Kim, Jae-Wook;Kim, Hee-Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.6 no.1
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    • pp.55-67
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    • 2010
  • Decision problem called an optimal release policies, after testing a software system in development phase and transfer it to the user, is studied. The applied model of release time exploited infinite non-homogeneous Poisson process. This infinite non-homogeneous Poisson process is a model which reflects the possibility of introducing new faults when correcting or modifying the software. The failure life-cycle distribution used generalized gamma type distribution which has the efficient various property because of various shape and scale parameter. Thus, software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement becomes an optimal release policies. In a numerical example, after trend test applied and estimated the parameters using maximum likelihood estimation of inter-failure time data, estimated software optimal release time.

Inter-scale Observation and Process Optimization for Guanosine Fermentation

  • Chu, Ju;Zhang, Si-Liang;Zhuang, Ying-Ping
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2005.06a
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    • pp.233-244
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    • 2005
  • Guanosine fermentation process can be well predicted and analyzed by the proposed state equations describing the dynamic change of a bioreactor. Pyruvate and alanine were found to be characteristically accumulated along with the decline of the guanosine formation rate during the mid-late phase of the process. The enzymological study of the main pathways in glucose catabolism and the quantitative stoichiometric calculation of metabolic flux distribution revealed that it was entirely attributed to the shift of metabolic flux from hexose monophosphate (HMP) pathway to glycolysis pathway. The process optimization by focusing on the restore of the shift of metabolic flux was conducted and the overcoming the decrease of oxygen uptake rate (OUR) was taken as the relevant factor of the trans-scale operation. As a result, the production of guanosinewas increased from 17 g/L to over 34 g/I.

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An Analysis of stress concentration and crack in injection mold by cavity pressure (사출금형에서 내압에 의한 응력집중 및 크랙 분석)

  • Choi, Sung-Hyun;Hang, Su-Jin;Choi, Sung-Ju;Lyu, Min-Young
    • 한국금형공학회:학술대회논문집
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    • 2008.06a
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    • pp.159-162
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    • 2008
  • High pressure is involved during injection molding operation specially packing phase. Cracks in the mold are often occurred by high cavity pressure. In this study, structural analysis of mold has been performed using commercial softwares, Abaqus and Ansys, to investigate cause of crack in the injection mold. Structural analysis contains four cases: stress distribution according to the cavity pressure, stress concentration according to the boundary conditions, stress concentration for inter-locking design of mold, and stress concentration for distributed cavity pressure. Through this study it was observed that the locations of stress concentrations were coincident with locations of crack. Robust mold design is being required to withstand high cavity pressure.

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