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      • PWM AC-DC 컨버터의 입력전류 직접추종제어

        우정인,최선영,정영일,서정기,허태원 東亞大學校 大學院 1999 大學院論文集 Vol.24 No.-

        본 논문에서는 PWM AC-DC 컨버터의 정상상태 제어오차를 제거하고, 과도 특성을 향상시키기 위한 새로운 전류제어계를 제안한다. 먼저, 일반적인 PWM 컨버터에 대한 상태공간 모델로 표현된 수학적 모델이 제시된다. 컨버터의 상태공간 모델은 제안하는 전류제어계를 포함한 PWM 컨버터의 시뮬레이션에 사용된다. 본문에서 제안하는 정현추종 제어계는 교류성분의 전류를 직접추정 제어 하기때문에 좌표변환 알고리즘을 필요로하지 않는다. 입력전류 제어계의 전달함수롤부터 정상상태 오차가 영이되는 것을 입증한다. 그리고, 시뮬레이션과 실험을 통하열 본 제어방식의 타당성을 입증하고자 한다.

      • 악성 섬유성 조직구종 1예

        정미정,정우권,박영립,황규왕,김영근 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.1

        Malignant fibrous histiocytoma is the most common soft tissue sarcoma in adult life and shows a mixed proliferation of both fibroblastic and histiocytic cells. Because of its highly variable morphologic pattern, this tumor has often been confused with other sarcomas such as pleomorphic rhabdomyosarcoma and liposarcoma. We report a case of malignant fibrous histiocytoma occurring in a 22-year-old male who presented with a adult's fist-sized mass with several brown colored nodules on the right buttock of 3 years' duration. Histologic findings shows spindle cells arranged in a storiform pattern characteristic of the typical pleomorphic malignant fibrous histiocytoma.

      • SCISCIESCOPUSKCI등재

        Mechanical Characterization of Nano-Structured Materials Using Nanoindentation

        ( Ju Young Kim ),( Sung Hoon Kim ),( Jung Suk Lee ),( Kyung Woo Lee ),( Dong Il Kwon ) 대한금속재료학회 ( 구 대한금속학회 ) 2006 METALS AND MATERIALS International Vol.12 No.3

        The principal strengths of the nanoindentation technique, which is used extensively to measure the mechanical properties of nano/micro materials, are easy sample preparation and simple experimental method. Hardness and Young`s modulus are essential properties measured by nanoindentation; hardness corresponds to resistance to plastic deformation whereas Young`s modulus is related to elastic deformation. Two key difficulties arise in association with nanoindentation on small volumes: measurement accuracy and material response. Here we discuss the indentation size effect (ISE) considering tip bluntness and variation in hardness of nano-multilayers with a bilayer period, representative research on measurement improvement, and material response at nanoscales.

      • 데스크탑 밀링머신의 고속 스핀들 설계 해석

        장성현,황현영,정우영,홍정표,최영휴 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

        During a decade, there are many researches on microfactory which is the miniature, flexible, and efficient manufacturing system for the micro/meso scale machining device. Moreover many micro machine tool has developed in Japan, U.S., Europe, and Korea. Already we are developing a desktop milling machine with 380×450×450 ㎣ machine size for microfactory or BT (Bio technology) factory. In this study, we carried out the design analysis of a high speed spindle system for our desktop milling machine by using ADROS, which is our own developed S/W for dynamic design analysis of rotor systems. As the result, we obtained some analyzed dynamic characteristics of a spindle system, such as natural frequency, whirl frequency, critical speed, and harmonic response.

      • 실험적 진폐증에서 투여약제에 따른 면역학적 병리학적 조직변화

        윤임중,임현우,노영만,오상용,정장영,임영,김경아 가톨릭 대학 산업의학 쎈타 산업의학연구소 1993 韓國의 産業醫學 Vol.32 No.2

        To access the effects of some drugs such as piperazine phosphare, azathioprine and allopurinol in the experimental pneumoconiosis, 263 rats weighted 240-320 gm was divided into the control and eight experimental groups. To each group, the turbid solution mixed free silica, talc and natural coal dust of 50 mg in 0.8 ml saline were instilled intratracheally. At the begining and 5th week of experiment, piperazine phosphate(8mg/week orally), aspirin(1.5mg/day intramuscularly), azathioprine(25mg/day orally) and allopurinol(1.5mg/day orally) were administered simultaneously, while the dust turbid solution was only given to the control group. For each group the change of body weight. dry right lung weight, cellularity including total cell, macrophage, lymphocyte and neurtrophil in bronchoalveolar lavage fluid, superoxide ion, hydroxyproline, leukotriene B₄, tumor necrotsis factor, prostaglandin E₂were examined, and observed the pathological chages in lung tissue. The results were as follow : 1. The larger amount of their instilled dust and the longer observation period, the severer pathological findings were found in the lung tissue of each experimental group. 2. The body and dry right lung wight was not significantly changed in the experimental groups compared with the control group. 3. The number of total cell in bronchoalveolar lavage fluid was markedly less in the experimental group than the control one, while no significant difference was found in the percent alveolar macrophages and lymphocytes in both groups. However, the percent of neutrophiles was usually lower than in the control group. 4. The amount of superoxide ion was frequently less in the experimental group compared with the control one. 5. The amount of hydroxyproline was significantly lower in the experimental group than in the control one. 6. The amount of leukotriene B₄was usually less in the drug administered group than in the control one. 7. The amount of tumor necrotic factor was also frequently lower in each experimental group than in the control one. 8. The amount of prostaglandin E₂was usually higher in each experimental group than in the control one.

      • 노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

        백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

        연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

      • 한국인에서 혈소판 당단백 Ⅱb/Ⅲa 유전자 다형성과 관동맥 성형술 후 재 협착과의 관계

        이민수,이정우,김보영,임대승,강정아,김정희,김윤철,성보영,최성준,성인환,전은석 충남대학교 의과대학 지역사회의학연구소 2000 충남의대잡지 Vol.27 No.2

        Platelet aggregation is the final pathway of acute coronary syndrome such as acute myocardial infarction and unstable angina. Platelet glycoprotein IIb/IIIa is a membrane receptor for fibrinogen and yon Willebrand factor and it plays an important role in platelet aggregation and in the pathogenesis of acute coronary syndrome. It is known that polymorphism of the gene that encoding platelet glycoprotein IIb/IIIa(PI^A1/A2) is strongly related to acute coronary syndrome in Caucasian, but not in Koreans. We investigated relationship between platelet glycoprotein llb/Illa gene polymorphism and restenosis of coronary artery after angioplasty in Koreans. Total 371 patients(M=251. F=120) were enrolled. Angioplasty group comprised 143 patients who underwent coronary angioplasty, and in the angioplasty group, restenosis group comprised with the 65 patients who had restenotic lesion over 50% of luminal diameter in follow-up coronary angiography. Normal group comprised 153 patients who had no significant angiographic lesion and variant angina group comprised 75 patients who were positive in ergonovine test. Genomic DNA was extracted from peripheral arterial blood. To determine the frequency of P1^A1/A2 genotype, polymerase chain reaction(PCR) was done and the product was restricted with Mspl. 3%. agarrose gel electrophoresis showed restriction fragment length polymorphism. Clinical profile and risk factor were also reviewed. Among all 371 patients of study group, genotype of only one patients in restenosis group if is proven to be PI^A1/A2 heterozygote. All patients of normal study group, no restenosis group, and the other patients in restenosis group have an PI^A1 homozygote genotype. In our study, platelet glycoprotein IIb/Illa polymorphism has no relationship with restenosis of the coronary artery after angioplasty in Koreans. But the genotypic frequency of platelet glycoprotein IIb/IIIa gene polymorphism in Koreans is concordant with that of previous studies.

      • KCI등재

        고령자 남녀와 20대 남녀에 있어서 다양한 등속수축중 최대 모멘트의 비교

        金智源(Ji-Won Kim),金相佑(Sang-Woo Kim),文基旭(Ki-Wook Moon),嚴光文(Gwang-Moon Eom),李泳揆(Young-Gyu Lee),南貞淑(Jung-Sook Nam),朴寬龍(Kwan-Yong Park),金耀翰(Yo-Han Kim),洪廷和(Jeong-Hwa Hong),朴炳奎(Bung-Kyu Park) 대한전기학회 2008 전기학회논문지 Vol.57 No.10

        In this paper, we investigated the maximum ankle joint plantarflexion moment (MPM) of young and elderly subjects during various modes of isokinetic contractions with special interest in the elderly females who were reported to have higher fall rate than the elderly males. Subjects include the young subjects (14 males: 22.7±2.5yrs, 13 females: 20.5±1.3yrs) and the elderly subjects (17 males: 65.8±10.5yrs, 26 females: 71.4±5.2yrs). The MPM was normalized by each subject's body weight. The MPM of elderly females was the weakest among the groups, particularly, at the eccentric contractions. The male-to-female ratio of MPM was greater in the elderly than in the young and the young-to-elderly ratio of MPM was greater in female than in male, both during the eccentric contractions. The result suggests that the decreased muscle force per body weight, especially at the eccentric contraction, may be one reason for the more frequent fall of the elderly female than the elderly male.

      • KCI등재

        정신분열병에 대한 리스페리돈의 효과 및 안정성

        이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

        연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

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