• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.814-818
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• 2004

최근 기상이변이 빈번하여 자연재해에 대한 방재대책의 중요함이 절실히 요청되는 시점에서 수공구조물들의 설계빈도를 상향조정하는 등의 대책이 마련되고 있는 실정을 고려할 때 유역의 수문학적 안정성을 확보하기 위한 최적방안을 마련하는데 필요한 강우의 임계지속시간 결정에 대한 연구를 수행하였다. 홍수제어를 위한 수공구조물은 그 특성상 계획홍수량 결정에 최대치 개념이 도입되어야 하므로, 설계강우의 지속기간을 결정할 경우 강우로 인한 최대유출과 홍수총량이 최대가 되는 임계지속기간을 이용하여 검토하는 것이 필요하다. 본 연구에서는 합성단위도(Clark방법, Nakayasu방법, SCS방법)등 각 수문요소에 따른 임계지속기간의 변동양상을 파악한 길과 24시간 강우지속시간시 총유출량 보다 임계지속시간개념으로 산정한 유출량이 크게 산출되었으며, 시간분포모형(Huff의 4분위법, IDF곡선 분포법, Mononobe방법)별 적합성을 평가함으로써 수문설계시 활용 할 수 있는 자료를 제시하고자 하였다.

• Science of Emotion and Sensibility
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• v.1 no.1
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• pp.123-133
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• 1998

시계열 예측은 효과적인 기업 경영에 반드시 필요한 활동이지만, 이와 관련 인간의 인지처리 과정에 대한 연구는 아직까지 미비하다. 본 연구는 인간 감성이 시계열 예측에 미치는 영향을 탐색하였다. 본 실혐에서는 반복을 통한 2(감성) x 2(횟수) 팩토리얼 설계를 채택하였다. 감성은 청각, 시각, 후각자극을 통해 환경을 조성하고 준비된 시나리오를 연상케하여 유발시켰다. 12명의 대학, 대학원생이 실험에 참여하였으며, 감성의 영향을 탐색하기 위해 뇌파(EEG)와 피부저항(GSR)이 후두엽(Oz)과 전두엽(Fz)에서 측정되었다. 그 결과 인간의 감성은 예측에 유의적인 영향을 보였다. 즉, 피험자가 부정적인 감성을 갖을 때 긍정적인 감성에 비해 예측의 정확성이 높은 경향이 있었다. 그 이유는 부정적 감성일 경우 전두엽에서 베타가 많이 출현하였고, 이는 시계열 예측의 정확도를 향상시키는 역할을 하였다.

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.395-400
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• 1994

In order to improve anthocyanin production, effects of fungal elicitation in hairy root culture were investigated. fungal elicitor prepared from Fusarium moniliforme was the best in enhancement of anthocyanin production among the eight fungal elicitors tested. The optimum treat-ment time and concentration of treated elicitor for anthocyanin production were 12 hours and 3.28 mg carbohydrates per liter medium. Also, fungal elicitor was treated to hairy root culture in flat-bottomed fluidized-bed bioreactor. The anthocyanin production of elicited culture was enhanced 227% than non-treated.

• Applied Microscopy
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• v.1 no.1
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• pp.43-48
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• 1969

X-ray diffraction intensity of barium ferrite sintered at $1280^{\circ}C$ as first sintering, varing mole ratio of barium carbonate and iron (III) oxide was checked. The results corresponed to of that magnetic coercivity in previous peport. The microstructure and sintering condition were observed-by means of two step replica method without etching by electron microscope.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.55-58
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• 2003

IPMSM (Interior Permanent Magnet Synchronous Motor) is widely used in many applications such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives. In order to maximize the efficiency in such applications, this paper is proposed the optimal control method of the armature current. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM The proposed control algorithm is applied to IPMSM drive system, the operating characteristics controlled by efficiency optimization control are examined in detail by simulation.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3218-3222
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• 2013

The aminolyses, anilinolysis and pyridinolysis, of bis(2-oxo-3-oxazolidinyl) phosphinic chloride (1) have been kinetically investigated in acetonitrile at 55.0 and $35.0^{\circ}C$, respectively. For the reactions of 1 with substituted anilines and deuterated anilines, a concerted SN2 mechanism is proposed based on the selectivity parameters and activation parameters. The deuterium kinetic isotope effects ($k_H/k_D$) invariably increase from secondary inverse to primary normal as the aniline becomes more basic, rationalized by the transition state variation from a backside to a frontside attack. For the pyridinolysis of 1, the authors propose a stepwise mechanism with a rate-limiting step change from bond breaking for more basic pyridines to bond formation for less basic pyridines based on the selectivity parameters and activation parameters. Biphasic concave upward free energy relationship with X is ascribed to a change in the attacking direction of the nucleophile from a frontside attack with more basic pyridines to a backside attack with less basic pyridines.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3372-3376
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• 2013

The kinetic studies on the reactions of ethyl methyl (2) and ethyl propyl (4) chlorothiophosphates with X-pyridines have been carried out in acetonitrile at $35.0^{\circ}C$. The free energy correlations with X show biphasic concave upwards with a break point at X = H (2) and 3-Ph (4), respectively. A stepwise mechanism with a rate-limiting leaving group expulsion from the intermediate is proposed based on the magnitudes of selectivity parameters for both substrates. The considerably large values of ${\beta}_X$ = 1.50(2) and 1.44(4) with strongly basic pyridines and relatively small values of ${\beta}_X$ = 0.43(2) and 0.36(4) with weakly basic pyridines are interpreted as a change of the attacking direction of the X-pyridines from a frontside to a backside attack toward the chloride leaving group.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.981-988
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• 2018

In order to acquire an accurate TOF, this paper proposes a method that produces TOF by using a mathematical model for the envelope of the received signal obtained from a system dynamic model of ultrasonic transducer. The proposed method estimates the arrival time of the received signal retrospectively by comparing its wave form obtained after triggering point with its mathematical envelope model. Experimental result shows that the error due to variation of triggering point can be dramatically decreased by implementing the proposed method.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.557-560
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• 2007

The metabolic discrimination of safflowers from various geographical origins was performed using 1H nuclear magnetic resonance (NMR) spectroscopy followed by principal components analysis. With a combination of these techniques, safflower samples from different origins could be discriminated using the first two principal components (PC) of the 1H NMR spectra of the 50% methanol fractions. PC1 and PC2 accounted cumulatively for 91.3% of the variation in all variables. The major peaks in the 1H NMR spectra that contributed to the discrimination were assigned to fatty acid (terminal CH3), lactic acid, acetic acid, choline derivatives, glycine, and safflower yellow derivatives. In this study, we suggest that various types of safflower can be discriminated using PCA and 1H NMR spectra.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.74-77
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• 2009

Demands for high quality and productivity of precision mechanical parts are increasing greatly nowadays due to the rapid growth of information technologies and convergence industries. Therefore, core technologies for fabrication of precision mechanical parts are the fundamental issues, which are the precision machining, micro powder injection molding technologies, MR polishing, micro polymer processes, micro actuation modules and so on. These technologies are directly related to the mass production of high functional devices and machineries. Therefore, this study investigates the fabrication technologies of micro precision molds for advanced devices for possible commercialization in a near future.