• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.157-158
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• 1995

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.22-25
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• 2001

A thyristor switch circuit for capacitor discharge application, of which the equivalent circuit includes a resistor between cathode and gate of a reverse-conducting thyristor and an avalanche diode anti-parallel between its anode and gate to set thyristor tum-on voltage, is monolithically integrated by planar process with AVE double-implantation method. To ensure a lower breakdown voltage of the avalanche diode for thyristor tum-on than the break-over voltage of the thyristor, $p^+$ wells on thyristor p base layer are made by boron implantation/drive-in for a steeper doping profile with higher concentrations while rest p layers of thyristor and free-wheeling diode parts are formed with Al implantation/drive-in for a doping profile of lower steepness. The free-wheeling diode part is isolated from the thyristor part by formation of separated p-well emitter for suppressing commutation between them, which is achieved during the formation of thyristor p-base layer.

• 지역사회간호학회지
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• 제31권3호
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• pp.395-404
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• 2020

Purpose: This study was conducted to develop a predictive model for happiness of students in general high schools. The study was based on the theory of happiness integration and the literature review. Methods: Data were collected using a convenience sample of 231 first and second grade students in five general high schools in D city and K Province. The exogenous variables were optimism as personality factors, parenting attitude, academic stress and friend's support as happiness. The endogenous variables were self-esteem and resilience as mediating variables, and happiness of students in general high schools. Data collection was done from March 14 to March 28, 2019. The AMOS 22.0 and SPSS programs were used to verify the validity of confirmatory factor analysis and hypothesis models. Results: The factors that have the greatest influence on happiness of high school students are self-esteem and resilience. The explanatory power of happiness by these variables was 98.1%. The individual mediating effect and double mediation effect of these variables were found to be significant. Conclusion: As student's optimistic personality, parent's positive parenting attitude, and friend's support improve student's self-esteem and resilience, ultimately positively affecting high school students' happiness, so it is necessary to consider these factors and try to develop a happiness improvement program.

• 전기전자학회논문지
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• 제1권1호
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• pp.1-10
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• 1997

It is well-known that rectangular bulk-Si sensors prepared by etch or epi etch-stop micromachining technology are already in practical use today, but the conventional bulk-Si sensor shows some drawbacks such as large chip size and limited applications as silicon sensor device is to be miniaturized. We consider a circular-shape SOI(Silicon-On-Insulator) micro-cavity technology to facilitate multiple sensors on very small chip, to make device easier to package than conventional sensor like pressure sensor and to provide very high over-pressure capability. This paper demonstrates the cross-functional results for stress analyses(targeting $5{\mu}m$ deflection and 100MPa stress as maximum at various applicable pressure ranges), for finding permissible diaphragm dimension by output sensitivity, and piezoresistive sensor theory from two-type SOI structures where the double SOI structure shows the most feasible deflection and small stress at various ambient pressures. Those results can be compared with the ones of circular-shape bulk-Si based sensor$^{[17]}. The SOI micro-cavity formed the sensors is promising to integrate with calibration, gain stage and controller unit plus high current/high voltage CMOS drivers onto monolithic chip.

• Composites Research
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• 제17권4호
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• pp.25-31
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• 2004

본 연구에서는 다중세포로 구성된 타원형 단면 복합재료 블레이드의 정밀 1차원 보 해석모델을 개발하였다. 보의 정식화를 위하여 Reissner의 반보족에너지 함수를 이용하였으며, 고전적인 강성도 및 유연도법을 결합한 혼합보 이론 체계를 구축하였다. 타원단면의 특성계수들을 구하기 위해 단면의 외곽선을 유한개의 선분으로 분할하고 여기에 Gauss 적분을 수행하였다. 또한, 단면을 구성하는 각 세포에 대해 4개의 연속방정식이 충족되도록 구성하였다. 개발된 보 이론을 단일 및 이중세포로 구성된 타원형 복합재료 블레이드에 적용하였으며, 다차원 정밀 유한요소 해석 결과와 비교하여 그 타당성을 확보하였다.

• 한국강구조학회 논문집
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• 제9권3호통권32호
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• pp.333-340
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• 1997

본 연구에서는 복합재료로 구성된 복합적층판 및 쉘에 대하여 3차 전단 변형이론을 이용한 변위를 가정하여 단순지지 경계조건을 만족하는 변위형상함수를 퓨리예급수로 전개하고 동적 평형 방정식을 유도하여 뉴마크의 수치적분법을 사용하여 단면특성계수, 재료의 특성, 층의 배열에 따른 복합적층판 및 쉘의 비감쇄 동적응답특성을 연구하였다.

• Journal of Ship and Ocean Technology
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• 제5권3호
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• pp.36-44
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• 2001

The collision energy absorbing characteristics of side structure of the LNG carriers which have the cargo containment systems of the spherical and the membrane types are compared. A failure mechanism of the double hull side structures of 130, 000 $m^3$ class LNG carriers under sideways collision event has been simulated by using the detailed finite element calculations. In ship collision analysis, the finite element method based on explicit time integration has been use[1 with much success. Finite element modeling techniques for detail description of structural members antral ship motion regarding the dynamic behavior allowed to investigate the effect of bow shape and the initial contact position on side shell of collided ship. In the numerical simulations of the ship-to-ship sideways collision, the effect of the colliding bow shapes and the change of the colliding ship draft are investigated. The critical collision energy which is absorbed by a side structure of a collided ship until the fore-end of colliding ship arrives at the boundary of the cargo tank is calculated. The critical speed of specified colliding ships which can not penetrate the boundary of the LNG cargo tank of the collided ship under collision accident if evaluated.

• 한국전자파학회논문지
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• 제13권8호
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• pp.797-803
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• 2002

본 논문에서는 라이시안(Rician) 감쇄가 존재하는 채널 환경에서 협대역 잡음이 더하여진 경우에 대역 여파기를 통과한 수신신호의 위상오류에 대한 확률 밀도 함수를 유도하고 0차 모먼트가 1이 됨을 보임으로써 확률밀도 함수로서의 타당성을 검증한다. 일반적으로 감쇄 환경에서 시스템의 오류 확률은 먼저 가산성 백색 가우시안 잡음(AWGN : Additive White Gaussian Noise)만이 존재할 때의 오류 확률을 구한 후, 그 결과 식을 해당 감쇄에 대한 확률 밀도 함수로 평균을 취하여 구한다. 하지만 본 논문에서는 감쇄 환경에서의 수신 신호에 대한 위상 오류식을 구한 다음, 그 식을 한번의 이중 적분을 취함으로써 오류 확률을 구하게 된다.

• 정보저장시스템학회논문집
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• 제3권4호
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• pp.160-166
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• 2007

In this paper, the measured electrical resistance method is proposed to analyze the ramp-tab contact during the load/unload (L/UL) process. Since this method supplies the voltage change due to the resistance change, we can easily and conveniently identify the ramp-tab contact from the acoustic emission (AE) signal. At first, we carefully deposit the conductive material on the surface of the conventional ramp by sputtering method. The ratio frequency (RF) magnetron co-sputtering system is applied to accomplish the deposited double-layers on the ramp surface. One layer is the stainless steel for the conductive layer and the other is the titanium layer for the cohesive function between the ramp surface and the stainless steel layer. In order to guarantee the stiffness and damping properties of the original ramp, the deposited conductive layer is intended to have very thin thickness. After integration the proposed ramp device into the L/UL system and networking the electrical resistance circuit, the L/UL performance is experimentally evaluated by comparing the measured electrical resistance signal and AE signal.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.48-56
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• 2018

A potassium copper hexacyanoferrate (KCuHCF) embedded magnetic hydrogel bead (HCF-Mbead) was synthesized via a facile double crosslinking methods of $Fe^{3+}$ ionic binding and freeze-thaw for effective $Cs^+$ removal. The HCF-Mbead had a hierarchical porous structure facilitating fast access of $Cs^+$ ions to embedded active sites. The adsorbent showed enhanced $Cs^+$ removal properties in terms of capacity (69.2 mg/g), selectivity ($K_d=4{\times}10^4mL/g$, 1 ppm $Cs^+$ in seawater) and stability (>99.5% removal in pH 3~11) with rapid magnetic separation. This study further opens the possibility to develop an efficient material that links the integration of adsorption and recovery.