• 전력전자학회논문지
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• 제8권1호
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• pp.70-79
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• 2003

본 연구에서는 압전 변압기를 이용한 T5 28급 전자식 안정기를 제작하여 그에 관한 특성을 조사하였다. 제작된 전자식 안정기는 크게 정류부와 능동형 역률 개선 회로부, 마이크로 컨트롤러를 이용한 주파수 발진부와 피드백 제어 회로부, 그리고 하프-브리지 인버터 회로 및 압전 변압기포 구성하였다. 사용된 원칩 마이크로 컨트롤러(AT90S4433)는 주파수를 발진하는 발진 회로부와 형광램프에 인가된 전류값을 측정하여 램프의 구동여부를 판단하는 피드백 제어 회로부로 구성하였으며, 내부 프로그램에 의해 일정 주파수에서 주파수를 감소시킴으로서 램프 방전을 유도하고 방전을 확인 후 정상상태 구동을 하는 주파수 대포의 이동을 통해 형광램프에 일정한 출력을 유지하였다. 결과적으로 개발된 전자식 안정기는 기존의 자기식 안정기가 무겁고 부피가 크며 많은 손실과 깜박거림(Flicker)현상을 지니는 반면에, 75[kHz]대의 고주파수로 동작하면서 99.5[%]이상의 높은 역률과 12[%]이하의 낮은 총 고조파 왜곡률(THD), 그리고 1.5이하의 CF(Crest Factor)를 나타낸다. 따라서 본 연구에서 제작된 압전형 안정기근 기존의 안정기를 대체할 수 있으며, 소형 경량화 되고 높은 효율을 지니게 되므로 경제적 측면에서의 장점도 기대된다.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.694-702
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• 1995

Using the Korean red ginseng saponin, which is known to world-wide and thd effects of it have been investigated by many reserachers for years. Ginseng saponin, one of the major components of Korea ginseng root, has many various biologic effects, such as cytotoxic effect, tumorcidal activity, protein biosynthesis and membrane modifying effect. The purpose of this study was to evaluate effects of ginseng saponin on the alkaline phosphatase activity of ROS cells in culture. After ROS cells were seeded into a 96-well plate, 96-well plate cultured until confluence was obtained. To evaluate cytotoxic effect of total saponin in cultured ROS cells, the plates were added to each total saponin concentration (0-1mg/ml). After 48hr., cells were counted by stain with 0.2% trypan blue at randomly selected field microscopically. Also, to evaluate alkaline phosphatase(ALP) activity of total saponin in cultured ROS cell, the plate was added to each total saponin concentration (0-1mg/ml) and ALP activity was assayed. To evaluate time-course of ALP activity, $31.25{\mu}g/ml$ of saponin added to 96-well plate. After culture of 6, 12, 24 and 48hr., ALP activity test was performed. To evaluate effect of cycloheximide in ALP activity, 96-well plate was added to saponin and cycloheximide. In control group, the plate was added saponin only. The results were as follows. 1. After the various concentration of total saponin was added in the medium, 500 and $1000{\mu}g/ml$ of total saponin showed cytotoxic effect of ROS(P<0.005). 2. In contrast to control group, 7.6, 15.6, 31.25, 62.5 and $250{\mu}g/ml$ of total saponin increased ALP activity significantly. 3. Otherwise, 500 and $1000{\mu}g/ml$ of total saponin decreased ALP activity significantly(P<0.005). 4. As the time span increases, $31.25{\mu}g/ml$ of total saponin increased ALP activity. 5. Cycloheximide decreased saponin-indueced ALP actitity in ROS(P<0.005). These results suggest that Ginseng total saponin stimulates the ALP activity of rat osteoblastic cells.

• Journal of Power Electronics
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• 제11권4호
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• pp.408-417
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• 2011

The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

• Applied Biological Chemistry
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• 제24권1호
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• pp.7-14
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• 1981

몇개의 담자균류(擔子菌類)중 볏짚배지(培地)에서 효소생산(酵素生産)이 양호(良好)하고 균사생육(菌絲生育)이 빠른 균주(菌株)로 P. ostreatus 301과 L. edodes 3-1을 선정(選定)하여 이들 균주(菌株)의 효소생산(酵素生産)에 대한 최적배양조건(最適培養條件) 및 배지(培地)에 부원료(副原料)와 무기염류(無機鹽類)를 첨가(添加)했을때 효소생산(酵素生産)에 미치는 영향(影響)을 검토(檢討)하여 다음과 같은 결과(結果)를 얻었다. 1) Cellulase와 xylanase의 생산(生産)은 L. edodes 3-1이 protease는 P. ostreatus 301이 우수하였다. 2) 효소생산(酵素生産)의 최적조건(最適條件)은 배양온도(培養溫度)가 cellulase는 $30^{\circ}C$, xylanase와 protease는 $25^{\circ}C$, 수분함량(水分含量)은 75%, $pH\;5.0{\sim}6.0$이었다. 3) 배양기간(培養期間)은 P. ostreatus 301이 30일(30日) L. edodes 3-1은 35일(35日) 배양(培養)했을때가 효소생산(酵素生産)이 양호(良好)하였다. 4) 부원료(副原料)중에서는 대두박(大豆粕), 유채박(油菜粕), 참깻묵을 첨가(添加)했을때가 효소생산(酵素生産)은 양호(良好)하였으나 균사생육(菌絲生育)은 오히려 불량(不良)하였으며 미강첨가량(米糠添加量)은 30%첨가(添加)에서 좋았다. 5) 무기염류(無機鹽類)의 첨가(添加)는 대체적으로 효소생산(酵素生産)에 효과적(效果的)이었으며 $CaCO_3$는 5%, $CaSO_4$는 2% 첨가구(添加區)에서 좋았다.

• 한국응용곤충학회지
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• 제7권
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• pp.39-51
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• 1969

The study involved determination of resistance levels of spider mites ta argano-phosphates using topical application and slide dip techniques; laboratory serening tests of alternative acaricides using an O/P resistant strain and a field trial of the screened materials. 1. Strains of Tetranychus were from Timaru(TR), Havelock Narth (HNR), Lincaln (LN). Germany (GR, GN). Comparisons of the resistant strains and normal strains at the LD50 and LC50 levels were as follows : (a) Using the topical application tochnique; with Parathian. resistant levels of the GR. TR and HNR strains of T. urticae were respeativuly, 1035. 484 and 452 times as resistant' as the LN strain. (b) Using the slide dip technique; with Phosdrin, resistant of GR, TR and HNR strains of T. urticae were 635, 274 and 266 times greater respeativuly, than the GN strain. 2. The laboratory sereaning tests were carried out far their contact plus stomach and residual effect to assess the toxicities of eleven alternative materials which would be used far control of O/P resistant strain of T. urticae. The acaricide groups represented were 3 organo-chlorines (Spidex, Kelthane and C 8514), 2 nitrophenyls (UC 19786 and Morocide), 2 cyclic carbonates(Eradex and Morestan). I carbamate (UC2004 7A), 1 mixture of carbamate and orano-chlorine and 2 other chemicals (C 8677 and M2527). From all acaricide tested. Kelthane and Morocide were the most effective, folowed by Spidex and M2527. Morestan, C8514. C8677 and RS 143 were intermediate, but Eradex, UC 19786 and UC 20046A were poor. 3, The number of sapmles required for estimation of the population in the field evaluation of acaricidal effects was one giving the highest practical precision. It was decided, after preliminary sampling trials. to use samples of 30 leaves per replicate which gave a $5.7\%$ standard error. 4. In the field trials, Morocide applied at the $0.05\%\;and\; 0.04\%$ a. i. conc. to black currant trees gave excellent control of O/P resistant population of T. urticae for about 12 days, but Morocide 0.025 and Kel thane $0.02\%$ a. i. cone. gave efficient control for about 6 days. In other words. first applications of Kel thane ane Moroeide gave very high degrees of control of O/P resistant population of the two-spotted spider mite. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage of black Currants and strawberries by either acaricides at the concentrations used. Acknowledgment ... The authors are grateful to: Dr. R. P. pottinger, Senior Lecturer in Agricultural Zoology. Lincoln college. New Zealand. for his helpful assistance in aiding with the organization of thd field work. Department of agriculture officers for mite colonies. Mr. D. A. Slade, Technical Advisor. Fruitgrowers' Federation (now at Massey University) for his assistance and provision of mites for testing. Mr T. McRae of Timaru for permission to use his crops for field tests. The following chemical companies and I or their New Zealand agents for so readily supplying samples of acarides; Ivan Watkins-Dow Limited. Fruitgrowers Chemical Company Limited. Henry H. York & company (New Zealand). Shell Oil (New Zealand) Limited.

• 해양환경안전학회지
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• 제22권7호
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• pp.900-905
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• 2016

해양구조물에 전기 안전사고가 급증하면서 전력시스템 고조파 분야가 최근 많은 관심 받고 있다. 이것은 주로 비선형 (또는 고조파 생성) 부하가 일반적인 산업플랜트 전력시스템에서 계속 증가되고 있기 때문이다. 해양플랜트에서는 전력시스템의 안전설계로 인하여 고조파 문제의 발생률은 낮지만, 고조파 문제에 대한 인식은 전력시스템 설계의 신뢰성을 향상시키는데 여전히 도움이 될 수 있다. 전력시스템에 고조파 문제가 드물게 발생되는 경우, 이는 생성된 고조파의 크기 혹은 전력시스템의 공진 때문이다. 이 고조파 비교분석에 관한 연구는 전력부하를 고려한 부유식 액화천연가스 생산 저장 하역 (FLNG) 설비의 하역 운전 시나리오에 대한 전기적인 구성으로 비교분석하였다. 전기적인 네트워크 구성은 전기적인 네트워크 부하 흐름에서 볼 수 있다. 본 연구는 해양플랜트 전력시스템의 안전을 보장하기 위해 전기 모터 시스템의 고조파 효율에 초점을 맞추어 전력시스템 성능을 시뮬레이션을 통해 검증하였다. 또한, 본 연구의 설계분야에서도 운전 및 유지 보수의 향상시키기 위해 FLNG 설비의 전력시스템을 분석하였다.

• 사상체질의학회지
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• 제7권1호
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• pp.281-293
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• 1995

In order to investigate the effects of the $So{\breve{u}}m$-In $Sipj{\breve{o}}ndaebot^{\prime}ang$ and the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ on Yang-insufficient syndrome(陽虛)induced by hydrocortisone acetate and cold condition in experiemental animals(Rats), the author experimented with Body temperature, Body weight, Exercise time, cyclic-AMP and Hair conditions. The results were obtained as follows ; 1. In Changes of body Temperature, the soum-In $Sipj{\breve{o}}ndaebot^{\prime}ang$ group rose with statistical significance in comparison to the controlled group, and the Soum-In $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group rose with statistical singificance in comparison to the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group. 2. In changes of Body weight, the Soum-In Sipjondaebot'ang treated group and the Gukbang Sipjondabot'ang treatd group had increased with statistical significance in comparison to the controlled group, and the $So{\breve{u}}m$-In $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group showed an increasing tendency in comparison to the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$treated group. 3. In changes of Exercise time, the $So{\breve{u}}m$-In $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group and the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group had increased with statistical significance in comparison to the controlled group and the $So{\breve{u}}m$ $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group showed an increasing tendency in comparison to the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group. 4. In changes of plasma cyclic-AMP concentration, the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group and the $So{\breve{u}}m$ $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group showed an increased tendency in comparison to the controlled group. 5. In changes hair condition, the $So{\breve{u}}m$ $Sipj{\breve{o}}ndaebot^{\prime}ang$ terated group and the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ treated group showed a betterment tendency in comparison to the controlled group. From the above findings, thd $So{\breve{u}}m$ $Sipj{\breve{o}}ndaebot^{\prime}ang$ and the Gukbang $Sipj{\breve{o}}ndaebot^{\prime}ang$ groups also had an effect of Yang-insuffient syndrome, moreover, on Body thmperature, Body weight and Exercise time, both showed a singnificant effect.

• 대한한방내과학회지
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• 제22권2호
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• pp.161-174
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• 2001

Objectives : The purpose of this investigation is to evaluate the effect of Chungpesagan-Tang Extracts on reversible forebrain ischemia in Sprague-Dawley rats. Methods : the volume of cerebral infarction and edema, the pathohistological change of neurons, the number of survived neurons, neurotransmitters through immunohistochemical methods, proteins connected with neurotransmitters through immunohistochemical methods and the pathohistological change of neurons through electro-microscopy were investigated. From these reseach data, the protection of neurons and the activity of brain cells were examined. Results : 1. The infaction volume of the control group was 23.9%, and that of the sample group was 16%. 2. The brain edema volume of the control group increased by 17% compared to the normal group and that of the sample group increased by 10%. 3. The light microscopy revealed that the neurons in the ischemia-induced area and CA1 area of hippocampus were most heavily damaged and that the sample group was less damaged compared with the control group. Most pyramidal neurons died in 7 days when brain ischemia was induced. 4. The number of survived pyramidal neurons in the CA1 area of the hippocampus were studied. The normal group had 93 neurons/mm, survived the control group(after 3 days) had 21/mm, the control group(after 7 days) had 3/mm and the sample group 33/mm. 5. The immunohistochemical methods revealed that: (1) In the control group, the sensitivity of GABA, NOS, DBH were increased, and those of Synapsin, eEF-$1{\alpha}$ decreased. NOS and DBH had positive reactions in the control group, but negative in the normal group. (2) In thd sample group, the sensitivity of GABA, NOS, DBH were attenuated, and those of NPY, Synapsin, CaMKII, eEF-$1{\alpha}$ increased when compared to the control group. 6. The electro-microscopy revealed that most neurons died by necrosis and some neurons died by apoptosis. Several imflammation cells appeared in the injured area of neurons. The number of neurons in the sample group that died by ischemia decreased. But, the number that died by apoptosis did not significantly change. Conclusions : The data shows that the effect of Chungpesagan-Tang Extracts on reversible forebrain ischemia in Sprague-Dawley rats is significant.

• 한국해양학회지
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• 제22권2호
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• pp.105-118
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• 1987

금강 하구의 에스추어리 환경에서 6차에 걸친 야외조사 및 정선관측이 행해졌 다. 각 조사시기는 모두 다른 조차와 하천배수량의 조건을 보여 주는 기간이었다. 이 연구의 결과로서 금강하구에서의 세립질 퇴적물 퇴적작용에 최대 혼탁수의 형성 과 그 변화가 미치는 영향이 지대함이 나타났다. 금강 에스추어리의 최대혼탁수는 일차적으로 입구에서의 조차가 클 때는 나타나는 현상이며, 바닥 퇴적물의 재부유 에 의해 형성되어 진다. 이 환경에서는 최대 혼탁수가 지속적으로 유지되어 지지 않고, 반일, 반월 및 계절주기의 변화를 나타낸다. 반일 조석주기 동안에는 조류 유 속의 변화로 말미암 아세립질 퇴적물의 퇴적과 재부유가 반복되어 진다. 한편, 최대 혼탁수의 중심은 창조류와 낙조류가 반복되는 것에 상응하여 상-하류 이동을 반복 한다. 채대 혼탁수는 대조기-소조기의 변화에 따른 15주기의 변화를 나타낸다. 이렇 게 하여, 최대 혼탁수는 소조기 동안에 쇠퇴하고 대조기 동안에 확장된다. 하천 배 수량의 계절변화도 또한 최대 혼탁수의 생성과 소멸에 중요한 영향을 미친다. 우기 에 하천배수량이 증가하게 되면 조류가 낙조류 우세를 나타내고, 부유퇴적물들은 쉽게 외해로 유출되어 에스추어리 내에서의 체류시간이 감소되어 진다. 따라서, 이 와 같은 많은 하천배수량의 시기에는, 최대 혼탁수의 발단은 오직 대조기 동안으로 만 국한되어 지며, 조차가 감소함에 따라 최대 혼탁수는 소멸한다.

• 대한간호
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• 제33권1호
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• pp.65-79
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• 1994

The purpose of this study was to describe the job retainment factors and the level of job satisfaction, and to identify the relationship between job retainment and the level of job satisfaction among the registered nurses working in hospitals. Four hundred eight registered nurses currently employed at 8 hospitals in Seoul were surveyed for the study. The 39 item, 5 point likert scale questionnare was developed by the researcher. The internal consistency of job satisfaction was. 86 and that of job retainment was. 90 in Cronbach's alpha test. The data sas collected from July 15 to July 30, 1993. The SPSS/PC+statistical program was used for data analysis. The descriptive analysis of the characteristics of the subjects, the level of job satisfaction and the job retainment factors was done. The relationship between the job satisfaction level and the job retainment factors was tested with. the Pearson Correlation Coefficient analysis, and thd differences of job retainment scores among the sample was tested with t-test and ANDVA. The results of the study were summarized. 1. The mean age of the subjects was 29.7 years, 41.7% of them were married. 71.1% of them were 3 years course graduates, 71.8% of them were staff nurses, and the mean duration of experience was 6 years. 2. The factors related to professionalism(3.43), society(3.31), and interpersonal relationship(3.29) were significant in job retainment. The maximum score was 5.0 Two other factors, personal(3.05) and organization(2.83) factors, also showed relatively high scores. 3. The factors to the job satisfaction showed similar pattern as job retainment: professionalism (3.47), society (3.33), finance(3.31), interpersonal relationship(3.02), and organization(2.72). 4. Society related factors(r=.7420, p<.00l) and professionalism(r=.7249, p<.00l) had high correlation with job retainment. Personal(r=.6372, p<.001) and organizational(r=.3597, p<.001) factors had moderate relationship to job retainment. Finance(r=.3597, p<.00l) had significant but weak relationship to job retainment. 5. Age, marital status, job position, departmental involvement, experience, and continuity of employment of the sample showed significant differences in job retainment. However, the period of job retainment, number of children, educational level, type of hospital, previous employment experience were not significant. 6. lndiviuals older than 40 years of age, who were married, who held the position of charge or head nurse position, who worked in central supply or nursing administration showed significantly high job retainment score. This research indicates that the professionalism is the most significant factor in job retainment. In order to retain more experienced nurses, it is important to improve the profesionalism among nurses.