유한요소법을 이용한 PT의 전계분포해석

정의남,심상흥 三陟大學校 産業科學技術硏究所 1996 産業科學技術硏究論文集 Vol.1 No.-

In this study, the design program for optimal wire batch around service line is made to improve the dielectric strength at the primary winding using Finite Element Method. The automatic convergence algorithm for finding of limit object value using loop circulation method is developed to make the optimal design simulator. The modulation method is suggested to make division time faster which is very important for full program efficiency. As a result, the program execution time is reduced about 32% and the optimal wire batch design is obtained.

(Sr·Ca)TiO₃계 세라믹의 절연파괴 특성

심상흥 三陟大學校 2000 論文集 Vol.33 No.1

The (Sr0.85·Ca0.15)TiO₃+0.006Nb₂O5 ceramics were fabricated to form semiconducting ceramics by sintering at about 1350[℃] in a reducing atmosphere. After being fired in a reducing atmosphere, metal oxides(CuO) was painted on the both surface of the specimens to diffuse to the grain boundary. XRD analysis results showed that the specimens used in this study have the cubic perovskite structure. The Voltage-current characteristics of specimens used in this study appears that it is due to space charge condensed to interface between grain and grain boundary. The conduction mechanism of the specimens observed in the temperature range of 20~125[℃], and is divided into three regions having different mechanism as the current increased: the region I shows the ohmic conduction. The region II can be explained by the Poole-Frenkel emission theory, and the region III is dominated by the tunneling effect.

다결정 CdTe 박막의 특성분석

송우창,정의남,심상흥 三陟大學校 1996 論文集 Vol.29 No.1

CdTe Thin Films are prepared by vacuum evaporation. They fabricated variable substrate temperature are annealed at a range of 100[℃] to 400[℃] and their properties are studied. As a result of this paper, CdTe Thin Films evaporated on 100[℃] substrate obtain good structure. Increasing substrate and annealing temperature makes tranmittance at absorption edge, bandgap and resistivity increased. Resistivities of this paper are a range of 10??[Ωcm]∼10??[Ωcm].

방향성 결합형 광 소자의 최적화 해석

심상흥,이상교,박종국,박하용 三陟大學校 産業科學技術硏究所 2003 産業科學技術硏究論文集 Vol.8 No.1

Optimum conditions for the optical coupling phenomenon were studied through the BPM simulation technique for the design of directional optical divice which consists of the directional coupler. The parameters used in the simulation mere 1.5[㎛] wavelengths for light source, 3[㎛] of waveguide width. 2.25 of waveguide refractive index. 2.2 of substrate refracvive index, 3[㎛] of gap between wareguides and 18[V] of applied voltage respectively. Therfore. the optical paramaters will become efficient and easy using the electrode process to the optical device(modulator) fabrication.

산성비에 의한 에폭시 절연재료의 내트래킹성과 표면열화에 관한 연구

심상흥 三陟大學校 産業科學技術硏究所 1998 産業科學技術硏究論文集 Vol.3 No.-

We attempted to investigate the effect of acid rain on the change of surface conditions, and resistance to tracking and erosion of epoxy resins: First, we measured the contact angle, and weight reduction to investigate the change of surface conditions. And, from the results of a series of experiment, we concluded that the acid rain attacked epoxy resins, which lead to the increase of surface roughness and the decrease of contact angle. And second, we adopted IEC publ. 587 method to measure the resistance to tracking and erosion of epoxy resins, and as highly affected the deposited specimen in the tracking resistance as in the erosion resistance.

소결온도에 따른 0.6BZT-0.4BCN 세라믹스의 구조 및 마이크로파 유전 특성

심상흥,강기성,윤상옥 한국전기전자재료학회 2003 전기전자재료학회논문지 Vol.16 No.6

α-ZnAl₂S₄단결정의 Energy Gap의 온도 의존성에 대한 열역학적 함수 추정

심상흥,심낙순,박종국,오재한,박광호 三陟大學校 1999 論文集 Vol.32 No.1

In this work ? single crystals were grown by the chemical transporting reaction(CTR) method using high purity(6N) elements. The structure of grown ZnAl2S4 single crystals were cubic structure. The optical energy band gap was indirect band gap and the temperature dependence of optical energy gap was fitted well to Varshni equation. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gap.

Microwave dielectric properties of ceramic/glass composites with bismuth-zinc borosilicate glass

김관수,심상흥,김신,윤상옥 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.1

The microwave dielectric properties of ceramic/bismuth zinc borosilicate (BZBS) glass composites were investigated. The crystalline phases of ZnAl2O4 with a spinel structure in the Al2O3/BZBS glass composite and Bi2Ti2O7 with a cubic pyrochlore structure in the TiO2/BZBS glass composite were observed, indicating that BZBS glass was a reactive glass in these systems. A one-stage sintering occurred in the Al2O3/BZBS glass composite whereas a two-stage one might occur in the TiO2/BZBS glass composite. The dielectric constant (εr) of the Al2O3/BZBS glass composite exhibited almost the same value of about 10 within the sintering temperature range between 600-950 oC, implying that the application of the Al2O3/BZBS glass composite to substrates may therefore be shown to be appropriate. For the TiO2/BZBS glass composite, however, an improvement of the temperature coefficient of the resonant frequency (τf = +119 ppm/K) is necessary for the application as LTCC materials although the dielectric constant of this system had a proper value (~56) for an application to filters.

Nonstationary DOA 추정을 위한 VFF-PASTd

편용국,심상흥,윤상옥,임준석,강기성 대한전자공학회 2004 電子工學會論文誌 IE (Industry electronics) Vol.41 No.02

In this paper we propose a new subspace tracking algorithm based on the PASTd(Projection Approximation Subspace Tracking with deflation). The algorithm is obtained via introducing the variable forgetting factor which adapts itself to the time varying subspace environments. The tracking capability of the proposed algorithm is demonstrated by simulations in an abruptly changing DOA(Direct of Arrival) scenario. The estimation results of the variable forgetting factor PASTd outperform those of the PASTd in the nonstationary case as well as in the stationary case. 본 논문에서는 PASTd에 기반 한 부공간 추정 알고리즘을 제안한다. 제안된 알고리즘은 시변 부공간 환경에서 스스로 적응하는 가변망각인자를 도입하였고, 알고리즘의 추정 성능은 제안된 알고리즘과 DOA 목표를 가진 시나리오에서 비교하였다. 정재 비정재 상황에서 VFF-PASTd의 성능 결과를 보이고자한다.

RF 스퍼터링법에 의한 SCT박막의 전기적 특성

김원종,정의남,심상흥,박하용 三陟大學校 2001 論文集 Vol.34 No.1

In this study, The (Sr1-xCax)TiO3(SCT) thin films are deposited on Pt-coated electrode (Pt/TiN/SiO2/Si) using RF magnetron sputtering method with substitutional contents of Ca at various substrate temperature. The structural properties of SCT thin films are analyzed using SEM, XRD, and EDS, and the electrical properties are studied by measuring the dielectric properties and the electrical properties are studied by measuring the dielectric properties and electrical conduction. The experimental results of electrical properties are summarized as follow. The dielectric constant is increased with increasing the substitutional contents of Ca, while it is decreased if the substitutional contents Ca exceeded over 15[mol%]. The maximum dielectric constant of thin film is obtained by annealing at 600[℃]. The dielectric constant changes almost linearly in temperature ranges of -80~+90[℃]. The temperature properties of the dielectric loss have a stable value within 0.1 independent of the substitutional contents of Ca. The capacitance characteristics had a stable value within ±5[℃]. The drastic decrease of dielectric constant and increase of dielectric loss in SCT thin films is observed above 200[㎑]. All SCT thin films used in this study show the phenomena of dielectric relaxation with the increase of the increase of frequency. Ⅴ-Ⅰ characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature.