• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.202-211
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• 2014

The bulk current injection (BCI) and direct power injection (DPI) method have been established as the standards for the electromagnetic susceptibility (EMS) test. Because the BCI test uses a probe to inject magnetically coupled electromagnetic (EM) noise, there is a significant difference between the power supplied by the radio frequency (RF) generator and that transferred to the integrated circuit (IC). Thus, the immunity estimated by the forward power cannot show the susceptibility of the IC itself. This paper derives the real injected power at the failure point of the IC using the power transfer efficiency of the BCI method. We propose and mathematically derive the power transfer efficiency based on equivalent circuit models representing the BCI test setup. The BCI test is performed on I/O buffers with and without decoupling capacitors, and their immunities are evaluated based on the traditional forward power and the real injected power proposed in this work. The real injected power shows the actual noise power level that the IC can tolerate. Using the real injected power as an indicator for the EMS test, we show that the on-chip decoupling capacitor enhances the EM noise immunity.

• 동력기계공학회지
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• 제5권4호
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• pp.82-89
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• 2001

To design a structural or a mechanical system with the best performance, the main procedure of a typical design usually consists of repeated modifications of design parameters and the investigation of the system response for each set of these parameters. But this procedure requires much time, effort and experience. Sensitivity analysis can provide systematic information for improving performance of a system. The author has studied on the development of the structural analysis algorithm and suggested recently the transfer stiffness coefficient method(TSCM). This method is very suitable algorithm to a personal computer because the concept of the TSCM is based on the transfer of the nodal stiffness coefficients which are related to force and displacement vectors at each node. In this paper, a new sensitivity analysis algorithm using the concept of the TSCM is formulated for the computation of state variable sensitivity in static problems. The trust of the proposed algorithm is confirmed through the comparison with the computation results using existent sensitivity analysis algorithm and reanalysis for computation models.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.104-107
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• 2000

Evaporative heat transfer characteristics of carbon dioxide has been investigated. Experiment has been carried out for seamless stainless steel tube with outer diameter of 9.55 mm and inner diameter of 7.75 mm. Direct heating method is used for supplying heat to the refrigerant was uniformly heated by electric current which was applied to the tube wall. The saturation temperature of refrigerant is calculated from the measured saturation pressure by using an equation of state. Inner wall temperature was calculated from measured outer wall temperature, accounting for heat generation in the tube and heat conduction through the tube wall. Mass Quality of refrigerant was calculated by considering energy balance in the preheater and the test section. Heat fluxes were set at 12, 16, 20, 23, and $27kW/m^2$, mass fluxes were controlled at 212, 318, 424, and $530 kg/m^2s$, and saturation temperature of refrigerant were adjusted at 0, 3.4, 6.7 and $10.5^{\circ}C$. From this study, heat transfer coefficients of carbon dioxide have been provided with respect to quality for several mass fluxes, heat fluxes. Finally, the experimental results in this study are compared with the correaltion by Gungor and Winterton(1987).

• 한국항공우주학회지
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• 제33권3호
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• pp.39-46
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• 2005

본 논문에서는 광범위한 함수 근사성질을 갖고 있는 신경회로망을 이용하여, 시스템의 입출력 조화성분의 선형관계를 표현하기 위해 추정된 전달행렬의 적용범위를 확장할 수 있는 적응 고차조화제어(Higher Harmonic Control, HHC) 기법을 제안하고 있다. 신경회로망의 학습신호는 추정된 전달행렬을 기반으로 계산된 최적제어 이득 값 행렬을 이용하여 구성된다. 내부 안정성을 보장하기 위하여 신경회로망의 가중치 학습방법은 Lyapunov 직접 방법을 이용하여 유도하였다. 6개의 입력과 2개의 출력을 갖는 비선형 시스템에 대한 시뮬레이션 결과를 통해 적응 고차조화제어 기법이 불확실한 전달행렬에 적용 가능함을 보였다.

• Bulletin of the Korean Chemical Society
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• 제5권3호
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• pp.121-126
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• 1984

The charge transfer complex formations between indole derivatives and methylviologen were investigated spectroscopically. In aqueous solutions near room temperature, the order of complex stability was tryptamine < tryptophan < indole < indole acetate, which is the reverse order of the magnitude of molar absorptivities. This was interpreted as involvement of contact charge transfer. The decrease of enthalpy of complex formation (-${\Delta}$H) was highest in tryptamine, and lowest in indole acetate. ${\Delta}$H and entropy of complex formation (${Delta}$S) varied nearly in a linear fashion with isokinetic temperature $242^{\circ}$K. These results were attributed to the hydration-dehydration properties of the side chains in indole derivatives. Except indole acetate, the complex formations were greatly enhanced by the addition of sodium dodecyl sulfate(SDS). However, the direct relationship between the enhanced complex formation and SDS micelle formation was not found. The enhanced charge transfer interaction inSDS solutions was attributed to the increased ${\Delta}$S by interaction between methylviologen and SDS in premicellar level. The order of complex stability in SDS solutions was indole acetate < tryptophan < trypamine < indole, which reflects the hydrophobicity of indole derivatives as well as electrostatic interaction between indole derivatives and methylviologen associated with SDS.

• Bulletin of the Korean Chemical Society
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• 제17권11호
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• pp.1061-1065
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• 1996

The charge transfer compounds of tetrathiafulvalene (TTF) with the general formula of (TTF)mMCln, (M=Au, Pt, Ir, Os) were prepared by the direct reaction using excess HAuCl4·3H2O, H2PtCl6·xH2O, H2IrCl6·xH2O and H2OsCl6 respectively. The powdered electrical conductivities (σrt) at room temperature are given as follows; (TTF)3AuCl2, 4.53×10-3; (TTF)3.5AuCl2, 6.37×10-3; (TTF)3PtCl4, 5.51×10-4; (TTF)2IrCl4, 2.40×10-5; (TTF)OsCl4·1/2C2H5OH, 4.46×10-7 Scm-1. Magnetic susceptibility, electronic (UV-Vis.), vibrational (IR) and EPR spectroscopic evidences indicate that there is incomplete charge transfer from the TTF donor to gold, platinum, and iridium respectively, and that there is essentially complete charge transfer to osmium, thereby resulting a relatively low electrical conductivity in osmium compound. The EPR and magnetic susceptibility data reflect that the metals are in diamagnetic Au(Ⅰ), Pt(Ⅱ), Ir(Ⅲ), and Os(Ⅱ) oxidation states, and the odd electrons are extensively delocalized over the TTF lattices in each compound.

• Journal of Power Electronics
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• 제19권1호
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• pp.254-264
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• 2019

This paper proposes an indirect current control technique based on a proportional resonant (PR) approach for the seamless mode transfer of utility interactive inverters. Direct-current and voltage hybrid control methods have been used for inverter control under grid-connected and islanded modes. A large bandwidth can be selected due to the structure of single-loop control. However, this results in poor dynamic transients due to sudden changes of the controller during mode changes. Therefore, inverter control based on indirect current is proposed to improve the dynamic transients by consistently controlling the output voltage under all of the operation modes. A PR-based indirect current control topology is used in this study to maintain the load voltage quality under all of the modes. The design processes of the PR-based triple loop are analyzed in detail while considering the system stability and dynamic transients. The mode transfer techniques are described in detail for both sudden unintentional islanding and islanded mode voltage quality improvements. In addition, they are described using the proposed indirect control structure. The proposed method is verified by the PSiM simulations and laboratory-scale VDER-HILS experiments.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.277-278
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• 2018

Improvement of insulation performance of buildings is a major part. Adiabatic method The adiabatic method minimizes the heat loss of the building. External insulation uses insulation to prevent fire. Ambient air hazards are less prone to fire. When a fire occurs, a phenolic pattern is formed and bond strength with the wall increases. EPS insulation and phenol foam were used to compare external heat transfer and external heat transfer. The heat transfer properties of phenolic foam and styrofoam were evaluated as follows. In the mortar and styrofoam structure, the problem of styrofoam reaching the burning point occurred before the collapse of the mortar, and the phenol foam had a problem in that when the direct fire was continued on the phenol foam. The characteristics of continuous infiltration appeared. In the case of mortar and phenol foam + styrofoam, the heat penetrated into the interior due to the shrinkage due to the shrinkage of the carbon screen on the phenol foam. However, when reinforced with glass mesh on the outer surface, And to reduce infiltration.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.184-190
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• 2015

NVH engineering has become a hot issue due to radical technology changes and development in automotive industry since customers' expectations and needs for their vehicle is taken to a higher level. However, the source identification and quantification of the road noise within a vehicle is still not at the level where it needs to be to meet their expectations due to its' complex transfer path and difficulties in path optimization. The primary focus of this research is on direct force obtaining method at suspension hard points using suspension test rig. Directly obtained forces at suspension to body mounting points are critical and crucial for determining the effects of design changes of the suspension has on road noise performance. Direct force obtaining method has its limitation in sensor installation within an actual vehicle therefore, many has been indirectly calculating forces using full matrix inversion method or dynamic stiffness method. In this study, to circumvent this limitation, a suspension rig is used. Then, the suspension rig is verified through a comparative analysis of its dynamic behavior between the actual vehicle by cleat test on chassis dynamometer.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.73-73
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• 2001

This study was to examine whether the vitrified, one-step diluted and direct transferred Hanwoo IVM/IVF/IVC blastocysts can be successfully survived in vivo and they were succeeded into the live birth. For vitrification, blastocysts were serially exposed in glycerol (G) or/and ethylene glycol (EG) mixtures [10% (v/v) G for 5 min, 10% G plus 20% EG (v/v) for 5 min, and 25% G plus 25% EG (v/v) for 30 sect] which is diluted in 10% FBS added D-PBS. Thawing of straw was carried out in air for 10 sec and then in water bath of $25^{\circ}C$ for 20 sec. One-step dilution within the straw was done in water bath of $25^{\circ}C$ for 1 min. Vitrified and one-step diluted embryos were directly transferred into 36 (natural or hormone induced synchronized) recipient cows in 6 areas of Kyungsang Buk-Do. Pregnancies were confirmed at first when recipient cows did not return to the subsequent estrus cycle, and later by manual palpation per rectum on day 45, 90 and then living calves were derived into parturition. Overall pregnancy was 33.3%(12/36), However, higher pregnancy was obtained when the recipients exhibited estrus one day earlier than the age of transferred embryos (53.3 vs 25.0-27.3%), irrespective of synchronization methods. Also, parous recipients became pregnant higher than nulliparous heifers, And, there were not different in pregnancy rates by the aspect of corpus luteum (CL) quality of recipients (good, 29.4; fair, 37.5; poor, 33.3%). One hundred eight of frozen-thawed Hanwoo blastocysts were directly transferred into 36 recipient cows. In 12 of pregnant cows, 3 cows were aborted and 9 cows were calved [single, 66.7% (6/9): twin, 33.3% (3/9)]. Total embryo implantation rate was 11.1% (12/108). However, 9 Hanwoo calves were lived. Therefore, these results demonstrate that direct transfer technique of vitrified and one-step diluted bovine blastocysts can be applied easily and effectively with the higher pregnancy rate on field trial without the equipment and embryological skills.