• 한국자동차공학회논문집
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• 제3권5호
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• pp.82-89
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• 1995

The three-dimensional fluid motion through the intake port and cylinder of a single DOHC SI engine was investigated with a commercial computational fluid dynamics simulation program, STAR-CD. This domain includes the intake port, intake valves and combustion chamber. Steady induction port flows for various valve lifts have been simulated for an actual engine configuration. The geometry was obtained by direct interface with a three-dimensional CAD software for complicated port and valve shape. The computational grid was generated using the commercial preprocessor ICEM CFD/CAE. Detailed procedures were presented on the generation of the geometry and the block-structured mesh. A standard k-${\varepsilon}$ turbulent model was applied to consider the complexity of the geometry and the fluid motion. The global flow patterns and the distributions of various quantities, such as pressure, velocity magnitude around the valve seat etc., were examined. The computational results, such as mass flow rate, discharge coefficient etc., for various valve lifts were compard with the experimental results and the computational results were found in good agreement with the experiment.

• 조명전기설비학회논문지
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• 제28권1호
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• pp.57-68
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• 2014

This paper propose a development of squirrel-cage induction motor(IM) for 5-phase 1.5kW, 220V, 60Hz in order to study a polyphase ac machinery that keep hold of advantages more than traditional three-phase a IM, such as reducing a amplitude of torque pulsation, decreasing electric noises, and increasing the reliability. Designed methods of the motor use a development tools with Maxwell 2D and Simplorer program. There are designed drawing of manufactured frames of the IM. amplitude and waveform of the generated electromotive force, FFT analysis of harmonics within output voltages and current, and reviewing a experiment results are shown by variable output. We are presenting a design and manufacture methods for the 5-phase squirrel-cage IM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.923-928
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• 1993

Genetic algorithms are powerful optimization methods based on the mechanism of natural genetics and natural selection. Genetic algorithms reduce chance of searching local optima unlike most conventional search algorithms and especially show good performances in complex nonlinear optimization problems because they do not require any information except objective function value. This paper presents a new model based on sexual reproduction in nature. In the proposed Sexual Reproduction model(SR model), individuals consist of the diploid of chromosomes, which are artificially coded as binary string in computer program. The meiosis is modeled to produce the sexual cell(gamete). In the artificial meiosis, crossover between homologous chromosomes plays an essential role for exchanging genetic informations. We apply proposed SR model to optimization of the design parameters of Single-sided Linear Induction Motor(SLIM). Sequential Unconstrained Minimization Technique(SUMT) is used to transform the nonlinear optimization problem with many constraints of SLIM to a simple unconstrained problem, We perform optimal design of SLIM available to FA conveyer systems and discuss its results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1059-1060
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• 2007

In this paper analysis of the characteristics in the three phase induction motor for the electric forklift truck is researched. There are two kinds of the Finite element analysis method. First thing is time domain analysis by the time transient method. Second thing is frequency domain analysis by method which assumes applied voltage and current sinusoidal. Especially in case of the characteristic studies, electromagnetic analysis is performed about each prototype motors. The obtained results are compared and the result of the test is examined. We could know characteristics of each prototypes and verify the design program of the motor through FEM. Finally this paper shows the factors of discord results of the analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.598-601
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• 2003

Most of all, DTC drive is very simple in its implementation because it needs only two hysteresis comparator and switching vector table for both flux and torque control. The switching strategy of a conventional direct torque control scheme which is based on hysteresis comparator results in a variable switching frequency which depends on the speed, flux, stator voltage and the hysteresis of the comparator. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple and inverter switching frequency. In this paper the influence of the amplitudes of flux and torque hysteresis bands and sampling time of control program on the torque and flux ripples are investigated. Simulation results confirm the superiority of the DTC under the proposed method over the conventional DTC.

• 생명과학회지
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• 제22권6호
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• pp.815-822
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• 2012

Resveratrol 유도체의 일종으로 stilbene계열 물질인 piceatannol은 암세포의 증식을 억제하고 apoptosis를 유발하는 것으로 알려져 있다. 본 연구에서는 A549 인체 폐암세포를 대상으로 piceatannol에 의한 암세포 증식억제와 연관된 부가적인 기전연구를 실시하였다. 본 연구의 결과에서 piceatannol이 A549 세포에서 extrinsic 및 intrinsic pathway의 동시 활성을 통하여 apoptosis를 유발하였음을 Fas/FasL의 발현 증가와 caspase-8 및 -9의 활성증가로 확인하였다. 또한 piceatannol은 caspase-3의 활성을 증가시켰으며, caspase-3의 다양한 표적 단백질들의 발현 감소가 동반되었다. 아울러 piceatannol에 의한 apoptosis 유발 과정은 iNOS의 발현 감소에 의한 NO의 생성 억제와도 연관성이 있었다.

• 동의생리병리학회지
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• 제21권1호
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• pp.158-164
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• 2007

Uterine leiomyoma is the most common tumor in the female genital tract. Although the tumor is benign, it is a matter of paramount importance since it often causes profuse menstrual bleeding, pressure symptoms and infertility. Nevertheless, the etiology and pathophysiology of this abnormality remain poorly understood. The traditional definitive treatment for uterine leiomyomas is hysterectomy and, even today, symptomatic leiomyomas are the leading cause of hysterectomy in Korea. Clearly, the development of a safe, effective, and nonsurgical method of treatment for leiomyoma would be of great benefit to many women. This study demonstrated growth inhibition of uterine leiomyoma cells using Haeohyultang (HT). When human leiomyoma cells were treated with Haeohyultang, cells showed dose-dependent growth inhibitory effect. Cell growth was inhibited by over 40% as determined by both cell counts and MTS assay. Reduction of cellular viability as a consequence of exposure to Haeohyultang resulted from induction of apoptosis, as assessed by DNA fragmentation, PARP cleavage, caspase 9 and caspase 3 assay. Flow cytometry analysis with uterine leiomyoma cells demonstrated sub G1 cell cycle arrest after treatment with drug Haeohyultang. But, the expression levels of p27 and p21 were not changed in Haeohyultang treated cells compared with control. However, the expression levels of clAP1 were reduced by Haeohyultang compared with control. This reduction of clAP1 data means activation of the caspase family, and then induction of PARP cleavage and apoptosis. These results suggest that Haeohyultang may be potential therapeutic approach in the clinical management of uterine leiomyoma.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.129-136
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• 2016

This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, $8mg/50{\mu}l$) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord.

• 대한간호학회지
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• 제28권1호
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• pp.132-142
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• 1998

This study was conducted to investigate whether exercise therapy applied in an efficacy expectation promoting program based on the self-efficacy theory of Bandura(1977) would increase self-efficacy and metabolism in NIDDM patients. The study design was a nonequivalent control group pre-test post-test quasi-experimental desist The exercise therapy applied in the efficacy expectation promoting program was composed of a staged exercise program, a small booklet relating personal experience with diabetes mellitus and a telephone coaching program on performance accomplishment. vicarious experience and verbal persuasion, which are all induction modes of efficacy expectation. The subjects of the study were twenty eight NIDDM patients who received follow-up care regularly through the out-patient department of endocrine medicine in one general hospital which had a diabetic clinic. Fourteen were assigned to the experimental group and fourteen to the control group. The experimental group participated in the exercise therapy applied in the efficacy expectation promoting program from three to five times per week for four weeks and the control group did not have the program. The collected data were analyzed using the X²-test, t-test, paired t-test, and Cronbach's Alpha using SPSS /PC/sup +/. The results are summarized as follows 1. Experimental group had higher efficacy score than control group(t=5.98, p=.00). And. There was a significant different in the efficacy score before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(t=-6.42, p=.00). 2. Experimental group did not have lower level of glucose metabolism than control group(FBS : t=.32, p=.75, HbAlC : t=.60, p=.55, pc 2hrs. glucose : t=-.29, p=.78). But, There was a significant different in the aunt of glucose metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(FBS : t=3.63, p=.003, HbAlC t=4.20, p=.00, pc 2hrs. glucose : t=1.93, p=.001). 3. Levels of lipid metabolism were partly a significant different between Experimental group and control group(triglyceride t=-1.87, p=.07, HDL cholesterol : t=-.29, p=.77. body weight : t=1.78, p=.09, Total cholesterol : t=-2.17, p=.04). And, There was partly a significant different in the amount of lipid metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(triglyceride : t=2.50, p=.03, HDL cholesterol : t=-.43, p=.67, body weight : t=5.34. p=.00, Total cholesterol : t=2.26, p=.04). In conclusion, it was found that exercise therapy applied in an efficacy expectation promoting program was an effective nursing intervention for increasing self-efficacy and metabolism.

• Molecules and Cells
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• 제38권1호
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• pp.40-50
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• 2015

In the interaction between plants and pathogens, carbon (C) resources provide energy and C skeletons to maintain, among many functions, the plant immune system. However, variations in C availability on pathogen associated molecular pattern (PAMP) triggered immunity (PTI) have not been systematically examined. Here, three types of starch mutants with enhanced susceptibility to Pseudomonas syringae pv. tomato DC3000 hrcC were examined for PTI. In a dark period-dependent manner, the mutants showed compromised induction of a PTI marker, and callose accumulation in response to the bacterial PAMP flagellin, flg22. In combination with weakened PTI responses in wild type by inhibition of the TCA cycle, the experiments determined the necessity of C-derived energy in establishing PTI. Global gene expression analyses identified flg22 responsive genes displaying C supply-dependent patterns. Nutrient recycling-related genes were regulated similarly by C-limitation and flg22, indicating re-arrangements of expression programs to redirect resources that establish or strengthen PTI. Ethylene and NAC transcription factors appear to play roles in these processes. Under C-limitation, PTI appears compromised based on suppression of genes required for continued biosynthetic capacity and defenses through flg22. Our results provide a foundation for the intuitive perception of the interplay between plant nutrition status and pathogen defense.