• Title/Summary/Keyword: temperature characteristic

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Characteristics Analysis of Capacitor Discharge Impulse Magnetizing Circuit using SPICE (SPICE를 이용한 커패시터 방전 임펄스 착자 회로의 특성 해석)

  • 백수현;김필수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.2
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    • pp.206-215
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    • 1994
  • A method for simulating general characteristics and temperature characteristics of discharging SCR of the capacitor discharge impulse magnetizer-magnetizing fixture system using SPICE is presented. This method has been developed which can aid the design, understanding and inexpensive, time-saving of magnetizing circuit. As the detailed characteristic of magnetizing circuit can be obtained, the efficient design of the magntizing circuit which produce desired magnet will be possible using our SPICE modeling. Especially, computation of the temperature rise of discharging SCR is very important since it gives some indication of thermal characteristic of discharging circuit. It is implemented on a 486 personal computer, and the modeling results are checked against experimental measures. The experimental results have been achived using 305[V] and 607[V] charging voltage, low-energy capacitor discharge impulse magnetizer-magnetizing fixture of air cleaner DC motor.

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A Partition Function for Liquid Metals (液體金屬의 常態和)

  • Kim, Wan-Kyue
    • Journal of the Korean Chemical Society
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    • v.6 no.1
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    • pp.36-46
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    • 1962
  • The author assumes that pure liquid metal is composed of molecular oscillators whose energy states are classified into two subgroups, i.e., A and B states, each being accesible to either one of the two sorts of lattice sites. The partition function involves constants characteristic of substance, which are obtainable from the Debye characteristic temperature assigned to its solid state. Calculation has been made for the various thermodynamic properties such as the vapor pressure, the entropy, and the heat capacity of liquid metals of GroupⅠelements over the temperature range from the melting points to the boiling points. The theoretical values thus obtained are in good accordances with those observed, within experimental error, although a slight derivation is observed in the atomic heat capacity.

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Diagnosis of power supply using time-series of infrared camera (열화상 카메라의 시계열 데이터를 이용한 수·변전설비의 진단)

  • Hwang, Suk-Seung;Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.6
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    • pp.1443-1447
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    • 2012
  • In this paper, the characteristic of temperature variation was reviewed according to pattern variation. In order to degrade of diagnosis of power supply by using time series data for temperature measured by infrared camera it was transformed into 2 dimension phase plane using Takens embedding method. As a simulation results we cannot completely confirm the characteristic behaviors of nonlinear dynamics in phase plane. However these results has a certain patterns, it requires verification method through additional research in the future.

Nonlinear Canonical Correlation Analysis of the Korea Precipitaiton with Sea Surface Temperature near East Asia

  • Kim, Gwang-Seob;Mingdong, Sun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.1620-1624
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    • 2010
  • The NLCCA has been applied to analyze the East Asia sea surface temperature (SST) and Korea monthly precipitation, where the eight leading PCs of the SST and the eight PCs of the precipitation during 1973-2007 were inputs to an NLCCA model. The first NLCCA mode is plotted in the PC spaces of the Korea precipitation and the world SST present a curve linking the nonlinear relationship between the first three leading PCs of Korea precipitation and world SST forthright. The correlation coefficient between canonical variate time series u and v is 0.8538 for the first NLCCA mode. And there are some areas' climate variability have higher relationship with Korea precipitation, especially focus on the north of East Sea' climate variability have represented the higher canonical correlation with Korea precipitation, with the correlation coefficient is 0.871 and 0.838. Likewise in Korea, most stations display similarly uniform distributing characteristic and less difference, in particular the inshore stations have display identical distributing characteristic. In correlation variables' scores, the fluctuation and variation trend are also seasonal oscillation with high frequency.

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Conceptual design of current lead for large scale high temperature superconducting rotating machine

  • Le, T.D.;Kim, J.H.;Park, S.I.;Kim, H.M.
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.2
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    • pp.54-58
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    • 2014
  • High-temperature superconducting (HTS) rotating machines always require an electric current of from several hundreds to several thousand amperes to be led from outside into cold region of the field coil. Heat losses through the current leads then assume tremendous importance. Consequently, it is necessary to acquire optimal design for the leads which would achieve minimum heat loss during operation of machines for a given electrical current. In this paper, conduction cooled current lead type of 10 MW-Class HTS rotating machine will be chosen, a conceptual design will be discussed and performed relied on the least heat lost estimation between conventional metal lead and partially HTS lead. In addition, steady-state thermal characteristic of each one also is considered and illustrated.

A study on the electrical characteristic of Schottky diode fabricated using various metals based on SiC thin film deposited by PECVD (PECVD로 증착된 SiC을 박막의 다양한 금속으로 제작된 SiC Schottky diode 전기적 특성에 따른 연구)

  • Song, J.H.;Kim, J.W.;Kim, J.G.;Lee, H.Y.
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.92-94
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    • 2004
  • In this investigation, 3C-SiC film deposited $1000{\AA}$ on the p-type silicon wafer which is resistance $0{\sim}30[{\Omega}{\cdot}cm]$ by PECVD (Plasma-enhanced Chemical Vapor Deposition). We deposited Cr, Ta, Pt in front of wafer to utilize DC-sputter for $500{\AA}$, the SiC Schottky diode made from Al ohmic contact about $4000{\AA}$, and to each different temperature which annealing in Ar atmosphere, we had forward characteristic analysis along to annealing temperature.

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A Characteristic on Difference of Water Content with Temperature and Compaction of Gypsum to Utilize Fill Material (석고의 축조재료 활용을 위한 온도조건에 따른 함수비 변화와 다짐 특성)

  • Seo, Dong-Uk;Yu, Bong-Seon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.3
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    • pp.47-54
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    • 2012
  • As a large construction such as highway, dam, reclaimed land etc. increase in number more and more, large amount of fill materials are required. It is needed to utilize a gypsum which is a by-product yielded from chemical plants, as fill materials. Though some studies have been conducted to know a engineering characteristic of gypsum, it is not certain that water contents were checked at $45^{\circ}C$ dry oven. This study proposed that water contents must be measured at $45^{\circ}C$ dry condition because gypsum is changed to other types as a dry temperature. As the results obtained by compaction tests, it is found that moisture of gypsum in compaction must be within -5.0~2.5 % O.M.C (optimal moisture content).

Annealing Characteristic of Phosphorus Implanted Silicon Films using an Ion Mass Doping Method (Ion Mass Doping 법을 이용한 Phosphorus 주입된 실리콘 박막의 Annealing 특성)

  • 강창용;최덕균;주승기
    • Journal of the Korean institute of surface engineering
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    • v.27 no.4
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    • pp.234-240
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    • 1994
  • A large area impurity doping method for poly-Si TFT LCD has been developed. The advantage of this method is the doping of impurities into Si over a large area without mass separation and beam scanning. Phosphorus diluted in hydrogen was discharged by RF(13.56MHz) power and ions from discharged gas were accelerated by DC acceleration voltage and were implanted into deposited Si films. The annealing characteristic of this method was similar to that of the ion implantation method in the low doping concentration. Three mechanisms were evolved in the annealing characteristics of phosphorus doped Si films. Point defects annihilation and the retrogradation of dopant atoms at grain boundaries as a result of grain growth played a major role at low and high annealing temperature, respectively. However, due to the dopant segregation, the reverse annealing range existed at intermediate annealing temperature.

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Pathological observations of rabbit hemorrhagic disease (토끼 출혈병의 병리학적 관찰)

  • 문운경;하준일;인민권;김순복;곽수동
    • Korean Journal of Veterinary Service
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    • v.23 no.4
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    • pp.309-312
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    • 2000
  • Pathological findings of natural cases of rabbit hemorrhagic disease was investigated. Clinically inappentence, increase in body temperature, depression, bloody foam from nostrils, and sudden death were recognized. Characteristic anatomical findings were hemorrhages in the lungs, liver, kidneys, and heart. Intestinal catarrh and retention of turbid urine in urinary bladder were also often observed. Severe .necrosis of hepatic cells, massive hemorrhages in many organs and membranous glomerulonephritis with hyaline droplet formation were characteristic changes under the microscopy. Perivascular cuffing of brain and catarrhal enteritis were also seen in many cases.

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The simulation of electrons swarm parameter in He gas is used by Boltzman equation (볼츠만 방정식을 이용한 Helium 가스의 전자군 파라미터 시뮬레이션)

  • 송병두;하성철;김대연
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.155-158
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    • 1998
  • This paper is calculated at electron swarm simulation by Back Prolongation of Boltzmann equation for range of E/N values from 0.1~200[Td], pressure P= 1.0[Torr], temperature T=300[ 。K], the electron swarm parameter(drift velocity, longitudinal . transverse diffusion coefficients, characteristic energy, etc) in He gas is used by electron collision cross section, particularly explicate the simulation technique, and consider electrical conduction characteristic of He gas.

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