• 한국융합학회논문지
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• 제9권4호
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• pp.143-150
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• 2018

본 연구는 기체연료레벨 값에 대한 정밀도를 측정하기 위하여 초음파의 음향매칭에 관한 실험적인 분석을 수행한 것이다. 연구 모델은 송신과 수신에너지를 결정시키는 세라믹 어세이 (Ceramic Assay)의 구성요소에 의하여 설계되었다. 실험 장치로는 12V-DC 전원공급장치, Control T1 Board, 오실로스코프 (DSO1072B), 초음파 프로브 그리고 패턴테이블 (Pattern T)able이 사용되었다. 불감지영역에 대한 분석결과 최대피크지점인 2.9V의 시작점을 기준으로 D (0.180m) < E (0.184m) < B (0.204m) < A (0.234m) < F (0.244m) < C (0.247m) 모델 순으로 점차적으로 불감지폭이 증가되는 특성을 확인할 수 있었다. 실험결과로부터 매칭레이어 (Matching Layer)의 치수가 Ø21*3+2t로 설계된 모델에서 가장 우수한 지향성 에너지를 생성할 수 있었다.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.81-85
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• 2003

PU block polymers are constituted by sequences of constitutional units CU which are : a diisocyanate T, a polyol or a polyamine V, an extensor E .Due to the CU different solubility parameters ,hard and soft micro domains are formed;they can aggregate into different phases. A linear PU can be described by two parameters R=T/N and $R_{E}$=(R-1)V/E.A stoichiometric model is proposed which gives the general formula of all the possible PU: X((TV)$_{k}$(TE)$_{n}$)$_{m}$X , where k and m can be calculated from the experimental molecular weights respectively of pre polymer and polymer and n= R-1.Physical properties depend on PU composition and on nature of CU. I.R. analysis is useful for discovering the hydrogen bonds location : DSC gives informations on the presence of the different phases .PALS analysis shows that nano cavities become tighter on increasing n. A series of particular Pus ,obtained from :TDI, a low molecular weight polyol, a cyclic extensor, at different R and RE was prepared and analysed. These PU are amorphous, monophasic and appear to be good candidates for membranes.nes.nes.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권3호
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• pp.187-194
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• 2005

An analysis of the 1/f or flicker noise in FD n-channel Double Gate SOI MOSFET is proposed. In this paper, the variation of power spectral density (PSD) of the equivalent noise voltage and noise current with respect to frequency, channel length and gate-to-source voltage at various temperatures and exponent $C(i.e\;1/f^c$ is reported. The temperature is varied 125 K from to room temperature. The variation of PSD with respect to channel length down to $0.1{\mu}m$ technology is considered. It is analyzed that l/f noise in FD n-channel Double Gate SOI MOSFET is due to both carrierdensity fluctuations and mobility-fluctuations. But controversy still exits to its origin.

• 전기화학회지
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• 제2권1호
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• pp.23-26
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• 1999

백금$(Pt)/0.1M\;H_2SO_4$, 전해질 계면에서 교류임피던스 측정과 위상이동 방법을 사용하여 Langmuir 흡착등온식을 정성적으로 해석하였다. 위상이동$(\phi)$은 음전위(E<0)와 주파수(f)에 따르며, Pt 일전극(음극)에 흡착된 수소원자$(H_{ads})$의 표면피복율$(\theta)$에 반비례한다. 중간주파수대$(1\~100 Hz)$에서 위상이동 변화$(\phi\;vs.\;E)$는 Langmuir 흡착등온식$(\theta\;vs.\;E)$의 계산과 해석에 사용할 수 있는 실험적인 방법이다. $Pt/0.1M\;H_2SO_4$ 전해질 계면에서 흡착평형상수(K)와 표준자유에너지$({\Delta}G_{ads})$는 각각 $3\times10^{_4}$와 20.1kJ/mol이다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.325-328
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• 2004

This paper deals with void crushing behavior by ingot forging process which consists of sequential operations of upset forging and bloom forging. The predicted results of void crushing behavior by the simplified global-local method using F.E. analysis showed that the inherent void at the top region of the ingots remains incompletely crushed even after several forging operations. From the results of the hot upset forging test using the billets with drilled voids, it was found that the bonding efficiency of the void after forging process increases with an increase in deformation, and a decrease of initial diameter of voids.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.250-252
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• 2000

A simple analysis method for inverter-fed induction motor using F.E.M and equivalent circuit is proposed. And an optimum shape of rotor slot for 2Hp inverter-fed induction motor is determined by combining the proposed analysis method and an optimization algorithm. Conjugate gradient method is used for the optimization algorithm. The optimization is performed for higher efficiency and reduction of harmonic loss in the inverter-fed induction motor. The optimization results are verified by comparing with those of the time-step F.E.A and the experiment.

• Journal of Nutrition and Health
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• 제9권2호
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• pp.24-39
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• 1976

The present study was undertaken to investigate the metabolic problems of high carbohydrate and cellulose diets of Korean. Forty males and same number of females of Albino rats, aged $45{\pm}5$days were divided into 95% high carbohydrate (H. CHO)group, 83.8% medium carbohydrate (M. CHO)group, 50% low carbohydrate (L. CHO) group and standard (Stand). group containing 72.2% sugar. Each group was divided into two again-1.55% cellulose group and non-cellulose group, 10 rats each of eight groups in both sexes. Cellulose was added to each of non-cellulose diets in the forms of spinach powder and rice bran. After 14 weeks the rats were sacrificed for chemical analysis and the results were elucidated as follows. (1) H. CHO+Cell. group showed the lowest value in body weight gained and shrinkage of almost all organs, in contrast with this group the L.CHO group showed higher body weight gained than Stand. group. M. CHO+Cell, group showed much the same body weight gained curve as Stand. group. (2) It was observed that cellulose group showed lower F.E.R and P.E.R value than non-cellulose group comparatively. (3) Total nitrogen retention and retention rate were decreaced in H. CHP groups compared with M. CHO or L. CHO groups. (4) The amount of feces was increased due to addition of cellulose to experimental diets and in accordance with the increasing total fecal excretion of nitrogen and glucose was also increased, especially noticeable in fecal glucose excretion. (5) It was noteworthy that serum cholesterol level was decreased due to addition of cellulose in H. CHO group and L. CHO group. (6) M. CHO+Cell. group was designed to reflect the average survey data of Korean diets and there was no significant differences on body weight gained, F.E.R, P.E.R, total nitrogen retention and hematology between M. CHO+Cell. and Stand. group. Total glucose excretion was increased due to dietary cellulose in M. CHO+Cell. group, but it seemed to be no metabolic problems in this group.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2111-2116
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• 2004

This paper shows how to improve the efficiency and output and to reduce NOx emission of Seoinchon GE 7F gas turbine, Korea Western Power Co. by replacing the existing 7F gas turbine with new 7FA+e gas turbine because the performance of 7F gas turbine was degraded due to long term operation. In this paper, we will study gas turbine development trend and O&M technology. Finally, we will review for uprate of Seoinchon 7F gas turbine to help someone to improve their units in the future.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1133-1134
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• 2013

• 대한전기학회:학술대회논문집
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• 대한전기학회 1983년도 하계학술회의강연.논문초록집
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• pp.59-60
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• 1983