정전압 제어를 위한 벅컨버터 모델링 및 설계

이창화 조선대학교 2011 국내석사

본 논문에서는 KA555 Timer을 이용하여 설계한 아날로그방식의 게이트 드라이브 회로와 Buck DC-DC converter를 설계하고, 이를 Pspice를 이용한 시뮬레이션과 실제 Buck DC-DC converter를 제작함으로써 이론적 해석과 실험을 통한 특성을 비교 분석하고자 한다. In this paper, analog method PWM circuit and the DC-DC buck converter had been a design. Using the Pspice simulation tool made a DC-DC buck converter design, theoretical analysis experiments have been to make the actual converter design and the actual converter and simulation is compare the characteristics.

만성신부전 환자에서 관상동맥질환의 임상상

이창화 한양대학교 대학원 2002 국내석사

Cardiovascular disease is a most important cause of death in patients with chronic renal failure. The prevalence of coronary artery disease has not been studied in Korean chronic renal failure patients. We investigated the relationship between the presence of significant coronary artery disease and the results of noninvasive diagnostic methods or typical symptoms of coronary artery disease. During the period from January of 1997 to December of 2001, 15 chronic renal failure patients received coronary angiography at Hanyang University Hospital for evaluating coronary artery disease. Clinical data and angiographic records of these patients were analyzed. In these patients, significant coronary disease was detected in 7 patients, minimal coronary artery disease in 5 and normal coronary artery in 3. Transient elevation of creatinine level after coronary angiography occurred in one patient. No significant coronary angiographic complication, such as perforation, distal coronary spasm, abrupt closure, or slow/no-reflow, occurred. Typical symptoms of coronary artery disease had 100% of sensitivity, 38% of specificity, and 58% of positive predictive value. EKG showed 86% of sensitivity, 38% of specificity, and 55% of positive predictive value. Cardiac enzyme study showed 57% of sensitivity, 75% of specificity, and 67% of positive predictive value. In patients who had abnormal EKG findings or typical symptoms of coronary artery disease but normal cardiac enzyme level, significant coronary artery disease was found in 33% by coronary angiography. TG levels was higher and CO2 content was lower in the significant coronary disease patients than in normal coronary patients. Blood pressure level was higher in patients with significant coronary disease than in patients with no significant coronary artery disease. But the duration of renal replacement therapy, levels of hemoglobin, calcium, phosphorus, albumin, and uric acid did not show any significant difference between two groups. In this study of chronic renal failure patients, who had positive findings in typical symptoms or noninvasive diagnostic methods for coronary artery disease only 47% of them had significant coronary angiographic results. Higher triglyceride and lower CO2 content were present in this patients group. Coronary angiography had minimal complication and high diagnostic accuracy in patients with chronic renal failure. 1. 목적 만성 신부전 환자에서 관상동맥질환은 가장 중요한 사망원인이며 많은 환자에서 관상동맥질환이 있다고 알려져 있다. 외국에서 만성 신부전 환자의 73%가 관상동맥 조영술에서 관상동맥 질환이 양성으로 나왔다고 보고하고 있으나, 국내에서 만성 신부전 환자를 대상으로 한 이와 같은 연구는 없었다. 이에 저자는 한양대학병원에서 임상적으로 관상동맥 질환이 의심되어 관상동맥 조영술 시행한 환자에서 실제로 관상동맥질환이 확인되었던 빈도를 조사하였다. 또한 환자의 관상동맥질환에 특이적인 임상증상이나 비침습적 검사 방법들의 결과와 실제 관상동맥 조영술 결과를 비교하여 임상증상이나 비침습적인 검사가 만성신부전 환자에서의 관상동맥질환의 진단에 어떤 역할을 할 수 있는지 조사하였다. 마지막으로 관상동맥질환이 확인된 군과 경미하거나 정상인 관상동맥 조영술 결과를 보인 군으로 나누어 만성신부전과 관련된 임상상이나 통상적인 검사결과들에서 어떤 차이점이 있는지 비교하였다. 2. 대상 및 방법 1997년 3월 일부터 2001년 12월31일까지 한양대학병원에 입원하여 임상적으로 관상동맥질환이 의심되어 관상동맥 조영술을 시행한 15명의 만성 신부전 환자를 대상으로 하였다. 관상동맥 조영술에서 내경의 50%이상 협착이 있었던 경우를 의미있는 관상동맥질환 양성군으로 정의하였고, 심전도에서 ST절 하강이나 상승 및 T파의 역위를 양성으로, 심초음파에서 심벽의 운동이 감소한 경우를 양성으로, CK-MB 가 8㎍/L이상 상승 또는 troponin I 0.5 ㎍/L이상 상승을 양성으로 하였다. 신대체 요법의 기간, body mass index, 고혈압, 콜레스테롤, 저밀도지단백, 고밀도지단백, 중성지방, 혈색소, 알부민, 칼슘, 인, 칼슘X 인 , alkaline phosphatase, 정맥내 이산화탄소 함유량을 관상동맥 조영술 결과에 따라 비교 분석하였다. 3. 결과 만성 신부전 환자에서 관상동맥질환이 의심되어 시행한 관상 동맥조영술 결과 전체 15예 중 7예(47%)에서 의미있는 관상동맥질환이 있었다. 관상동맥조영술과 관련되어 일시적으로 혈청 크레아티닌 수치가 상승한 경우가 1예 있었으나 호전되었고, 그 외 심한 출혈, 사망 등의 중한 합병증은 없었다. 비침습적 검사 결과를 관상동맥 조영술 결과와 비교하였을 때, 협심증의 특이적인 증상으로 관상동맥질환을 추측하였을 때, 민감도는 100%이었으나 특이도가 38%로 나와 양성 예측도는 58%이었고, 심전도결과는 민감도 86%, 특이도 38%, 양성 예측도 55%이었으며 심근효소 검사시 민감도 57%, 특이도 75%, 양성예측도 67%이었다. 심초음파 검사는 민감도 57%, 특이도 63%, 양성예측도 57%이었다. 심근효소와 심초음파 검사에서 정상이었으나 협심증의 증상이나 또는 심전도 이상소견이 있었던 환자들 중에서 단지 30%만이 관상동맥조영술에서 관상동맥질환이 관찰되었다. 관상동맥질환 양성군에서 수축기 평균혈압은 167±20.5 mmHg 이었고 이완기 평균혈압은 102±11.2 mmHg이어서, 비관상동맥질환군(135±16.1 mmHg 및 86±9.8 mmHg)에 비하여 유의하게 높았다(p=0.014). 중성지방은 관상동맥질환 양성군에서 168±72.4 mg/dL 이었으며 이는 비관상동맥질환군(80±33.2 mg/dL)에 비하여 높았으며( p = 0.008), 정맥내 이산화탄소 함유량은 관상동맥질환 양성군에서 18.9±3.9 mEq/L으로 비관상동맥질환군의 24.1±3.5 mEq/L 에 비하여 낮았다(p = 0.017). 신대체요법의 기간, body mass index, 콜레스테롤, 저밀도지단백, 고밀도지단백, 혈색소, 알부민, 칼슘, 인, 칼슘X 인, alkaline phosphatase 의 결과는 두 군간에 통계적으로 유의한 차이가 없었다. 4. 결론 한양대학병원에서 관상동맥질환이 의심되어 관상동맥조영술을 시행한 환자에서 실제로 관상동맥질환이 관찰된 경우는 47%이었다. 이 결과는 외국의 보고에 비하여 낮았다. 관상동맥질환의 진단에 협심증의 증상이나 심전도는 민감도에 비해 특이도가 너무 낮아 결과적으로 협심증이나 심전도 소견만으로는 관상동맥질환을 정확하게 예측하기에는 부적절하였다. 심근효소 검사나 심초음파 검사도 단독으로는 관상동맥질환의 진단 시에는 만족할 만한 정확도를 갖지 못하였다. 만성신부전 환자에서 관상동맥조영술은 시술자의 숙련도에 따라 차이는 있을 수 있으나 본 연구 대상자들에게는 큰 위험이 없이 진행된 비교적 안전한 검사이었다. 관상동맥질환이 만성 신부전 환자에게 가장 많은 사망의 원인임을 고려한다면, 만성 신부전 환자에서 관상동맥질환은 임상적인 소견이나 일반적인 비침습적검사 결과만으로 예측하는 것이 부적절하며, 정확한 진단과 적절한 치료를 위해서 적극적인 관상동맥 조영술이 필요하리라 생각된다.

고온초전도 케이블 단말 절연설계를 위한 기초 절연특성 연구

이창화 경상대학교 대학원 2005 국내석사

A research on several characteristics such as volume breakdown and surface discharge of insulators for a termination of power transmission class HTS cable was performed. In this paper, we investigated the surface discharge of glass fibre reinforced plastic under air, cryogenic nitrogen gas, and nitrogen gas media. And the breakdown characteristics of these media were also studied. Experimental results revealed that flashover voltage greatly depends on pressure, temperature, the kinds of insulating media and voltages, but it is slightly affected by shape and material of electrode. The breakdown voltage of liquid nitrogen, cryogenic nitrogen gas, and nitrogen gas deeply depends on the shape and dimension of electrode, kinds of voltages, and pressure. Moreover, the breakdown voltage of cryogenic nitrogen gas and flashover voltage of glass fibre reinforced plastic in the cryogenic nitrogen gas is also influenced by temperature and vapour-mist density of the gas.

Coproporphyrin簡易 定量法의 改善에 關한 硏究

이창화 고려대학교 대학원 1983 국내박사

평화번영정책과 초등학교 통일교육에 관한 조사 연구 : 통일교육의 평화교육적 접근 모색

이창화 제주대학교 교육대학원 2004 국내석사

��\戈� The terror on Sep. 11th 2001 in U.S.A. restores the concern about the peace. Without peace, as we have seen North Korea's nuclear conflict, the reunification between two koreas may be very difficult. The reunification policy of the new South Korean Government stresses more on peace than on reunification. Under the circumstance, this paper is to study the method of reunification education. I think that the peace education approach should be used in today's reunification education. To prove this point of view, I study some practical problems in the policy of peace and prosperity, and examine the present situation of reunification education in the 7th Curriculum in elementary school. In addition, having respect to the curriculum and the level of development of elementary school and case studies, I suggest some practical ideas of education as an approach of peace education. That is to say, basic direction (aims and contents), teaching and learning method in peace education as reunification education. Peace education in elementary school have to stress recognitive approach as well as affective approach to develop the will to practice. Teaching and learning method of peace education should integrate texts, specific activities, students' their own discretionary activities, practices and experiences. In conclusion, Reunification education in elementary school in the future depends on multiple approaches including development of more active programs.

都市管理政策의 改善에 관한 硏究 : 開發制限嘔逆 制度의 合理的 改善을 中心으로

이창화 東國大學校 經營大學院 1998 국내석사

City is very important as intellectual one of National economy activity because it has the character of Organic Complexity which imported periodic life and culture such it named as the gate to live with each other as it stands in many people as well as it has big difference as it caused to politics and societies which gives developmental basis as democratic city communications. As city issue is the biggest one among the biggest social issuing place of our social difference so it should be the one who has complexive holding one and independence of new frame for '2000 which followed by big changes of development of city society. Followings are the purpose of this research according to the problematic recognition basis in the above realities. At first, I returned to our city politics which given basic to new age and I defied purpose of political issue and new way of city politics and I studied out of good political way of its. At second, I restudied about our Development Restricted Zones at the view of city political research and taken out of its problems and calculated out of the social expense of regulation with analysis of numerous regulation effect about issue and real expense of regulation according to regional activity of regulations. At third, I want to concise to regional developmental improvement plan which acts the value of its origin as out land's natural products to be developed for very many way to study out of the point of comparatives with overseas institution for the activities in the course of original purpose of reviewing and defying of the improvement plan of DRZ institution as the lowest structure in the frame of further political way of its movement. So that basis of city politics which ready for '2000 will have to balances, set-moment, identification, internationalism, effect-moment and propose to defy and execute following items as political purpose. At first, it should be induced of lateral developmentation between cities to have balances of city growing and have to super insurance for the use of city land take out publicity in the city developmentation. At second, to improve set-moment of city environment improve natural movement and city life and delete traffic jam of city transportation and go highest way of city function and city developmentation. At third, for the completion of independence of city waving way it should be exhorted out communicative improvement of life culture and remind the independence way of city landscape. Furthermore, study holding for the plan which could improve international function of big cities. At forth, for the improvementation of effect-moment of city maintenance, should be acted more side city maintenance through science way and information way. To be effect enhancement of city politics, it needed good institution to have strength practical way, especially improvementation of the structure and political needed and city plan are the speedy way for the above mentioned way of. Among them as one of executive method of developmentation plan with the city, institution improvementation of multiple and institution at the law are the important to giving. D.R.Z has been operations as a one of three political accompaniments of land politics and city politics with city redevelopment politics and new city building politics as it imported by the purpose of protection of surrounding natural environment of city and security and limitation regulative of non empowered circling of city and the phenomenon of numbering. So that it has supportive nature whole by society and it evaluated as a politics of supreme in the world. But, to keep use for it as the method of city maintenance politics, to have strength the basis of strong institution and to expand affirmative function we propose as following ones to remake medium and long term politics. At first, remake D.R.Z growing to be effective political method for lateral developmentation of the region and held and executed city politics for having good way of building of new city and city re-developmental politics. At second, through restudy of national way improve institution rationally based upon the real echoing and it should be complished out lawful rationalism through independence institution and practical institution. Furthermore, the method of classification of activity as importing calculation regional institution which completed out the regional character to be studied out for many way. At third, new operational politics defying is needed. That is to say that focusing onto the politics of protection of fresh life environment and natural environment of city and take out active politics idea to re-accomplish the structure of life and regional structure. At forth, D.R.Z to be Induced in life and discuss it and evaluate being one of political effects as structurally and publicity it so that exhorting to the social public good. Searching of restrictive basis and maintenance operational method to be rationalized one to constitute conference institution for the preparation of long term politics as of maintenance commitee association of developmental limited region. For the issuing of developmental limited region it should be studied and remade essential solution as going to the narrowing way at the side of city politics to revival the effect of regional defying rather than of partial way on.

철강산업에서의 협업적 수요계획 시스템 모델링

이창화 仁川大學校 大學院 2003 국내석사

기존의 설비집약적 산업에서는 고객의 수요에 대한 정보를 얻으려는 노력보다는 생산중심의 "부분"적인 목표를 앞세워 생산계획을 수립함으로써 과잉생산, 기회손실에 의한 Loss를 당연한 것으로 생각하였다. 하지만 Business 형태의 Web으로 전환으로 인해 시간이 흐를수록 정보 공급망은 점점 더 복잡해져가고 신속함을 요구하고 있으며, 고객의 요구는 점점 더 개별화됨에 따라 기업으로 하여금 시장 수요에 맞춰 생산량을 조절하는 문제에 더욱 많은 노력과 비용의 투자를 요구하고 있다. 더불어 공급망의 구성하는 생산 부문과 유통 부물, 공급 부문은 상호 협력을 통해 유용 가능한 자원과 현재의 유동 수량을 정확히 산출해내기 위해 노력하여만 한다. 공급망 관리에서 협업을 통한 수요계획은 예측의 정확도를 높임으로써 그로인한 재고의 감소와 고객 서비스의 향상을 가져다 줄 수 있어야한다. 특히 철강산업에서는 능력할당을 고려한 수요계획이 수행되어야 하며 고객별, 지역별, 공급거점별 Level에 따른 적절한 계획이 필수적이라 할 수 있다. 본 논문에서는 공급망 관리에서의 협업적 수요계획의 중요성과 필요성에 대해 기술하고, 기존의 수요계획 프로세스의 한계와 철강산업에 적합한 협업적 수요계획 프로세스를 제시하고 대상업체에 적용을 통해 구체적인 모델을 제시하였다 또한 프로토타입의 설계를 통해 문제점에 대한 구체적인 해결방만을 제시하였다. The Company was focusing on Production which was Partial Mission rather than acquiring the Information of Customer in intensive Process Industry. The Company accepted Loss which is from Over-Production, Losing of Opportunity. After Changing to Web Environment, Supply Chain is more complicated and Need of Customer is more various. As a result the Company hard Works on Controlling Production rates, Production Quantities in Production Area and gathering exact Information which is about available Resource and available Quantities. Cooperated Demand Planning have to get decreasing of Inventory, Improving of Customer Service in Supply Chain Management. Specially Demand Planning that considers Allocation of Capacity is executed in Iron-Industry Demand Planning must be classified by Customer, Region and Supply Position Level

U형 천골 골절 환자에서의 경피적 천장골 나사못 고정술의 수술적 치료 결과

이창화 경북대학교 대학원 2013 국내석사

We evaluated the surgical outcome of percutaneous iliosacral screw fixation in the patients with U-shaped sacral fracture, retrospectively; neurologic improvement, correction of sacral kyphosis, complication. Eleven patients who had percutaneous iliosacral screw fixation surgery with sacral U-shaped fracture from April 2004 to March 2011 were analyzed. Mean follow-up period was 32 months(range, 12 ~ 74 months). Mean age was 35.8 years(range, 21 - 67 years). Male were 6 and female were 5. All patients were classified according to Roy-Camille classification, grade I were 7, grade II were 4. Neurologic injuries were classified by Gibbons classification. Sacral kyphotic deformity was corrected from 21.6° to 21.0° (p>0.05), and there was no progressive sacral kyphosis in all patients. Seven patients had neurological impairment at initial injury. In three cases, Gibbons score had improved. No more deterioration of neurologic symptom had shown after surgery. Screw loosening, reduction loss and deep infection didn't show on one year follow up after surgery. All patients started wheel chair ambulation within two weeks after surgery. Percutaneous iliosacral screwing could provide efficient fixation force to maintain fracture alignment and neurologic improvement on patients with minimally displaced and noncomminuted U-shaped sacral fractures, especially in polytraumatized patients.

Cooperation in IT industry in Northeast Asia

이창화 고려대학교 국제대학원 2006 국내석사

ABSTRACT This thesis aims to identify the strategies for the IT cooperation in Northeast Asia examining the current status of each nation and to recognize the important role of government in fostering domestic IT industry as well as accelerating the IT cooperation with China and Japan. This study analyzes the characteristics of three nations’ IT industry with SWOT analysis. Furthermore, the degree of current cooperation will be figured out by investigating trade and investment structure among China, Japan and Korea. This thesis emphasizes mainly the economic potential effects and seeks out strategies for the IT cooperation. It comes to the conclusion by looking at the role of Korean government for the successful IT cooperation. Major process of this thesis is five-fold: 1) SWOT analysis of three nations’ IT industry 2) current status of IT cooperation in the field of trade and investment 3) Economic effects of bilateral as well as trilateral IT cooperation 4) three nations’ strategies for the IT cooperation at both private and government sector 5) tasks of Korean government for the successful IT cooperation.

실직자의 근로의욕 고취를 위한 만다라 미술치료 사례 연구

이창화 원광대학교 2002 국내석사

우리 나라는 1997년 외환경제 위기 이후 많은 기업이 도산되고 그에 따라 수많은 직장인들이 실직을 하게 됨으로 인해 국가 및 개인의 경제적 손실뿐만 아니라 사회 구성원들에게 심리적 위축을 가져오는 결과를 초래하였다. 따라서 실직자의 문제해결을 위한 치료방법 중 본 연구에서는 만다라 미술치료를 통한 실직자의 근로의욕 고취 효과를 알아보고자 했다. 실직자의 근로의욕 고취를 위해 다음과 같은 구체적 목적을 설정하였다. 첫째, 만다라 미술치료를 통해 장기적 실업자들이 정서적 안정을 찾고, 긍정적인 사고를 회복 할 수 있도록 한다. 둘째, 만다라 체험을 통한 내면 탐색으로 개인의 긍정적인 에너지를 발견하고, 근로의욕을 고취 할 수 있도록 한다. 셋째, 전통문양을 이용한 만다라 미술치료를 통해 의식의 명료화를 거쳐 자아의 정체성을 확립한다. 이러한 연구 목적을 가지고 본 연구의 참가자는 원주 자활후견기관의 추천을 받은 남성 3명, 여성 2명으로 구성하였다. 미술치료 프로그램은 2002년 8월16일부터 2002년 11월 8일까지 총 12주로 사전모임 1회, 미술치료 10회로 매 회기마다 60분간, 작품 전시회 1회를 실시하였다. 또한 12회기 프로그램 종결 후 참가자들과의 인터뷰를 실시하여 참가자들의 심리적, 행동적 변화에 대해서 알아보고자 했다. 프로그램 실시는 본 연구자가 계획한 프로그램 안에 대하여 본인 혼자서 진행하였다. 이에 따른 주요 연구결과는 다음과 같다. 첫째, 참가자들은 초기의 심리적 불안과 우울을 극복하고 안정을 찾으면서, 위축되고 소극적인 행동도 적극적인 행동으로 변화됨을 볼 수 있었다. 이는 근로의욕을 고취할 수 있는 동기부여에 영향을 주었다고 생각한다. 둘째, 참가자들은 만다라 체험을 통한 자신의 이미지를 탐색하면서 긍정적인 삶의 태도 변화를 갖는 새로운 에너지를 찾을 수 있었다. 이는 새로운 현실의 발견과 적응하는데 긍정적 태도 변화의 기대 효과를 갖게 한다고 생각한다. 셋째, 참가자들은 우리의 전통문양을 이용함으로서 실직으로 인해 자신의 혼란된 정체성을 민족 집단무의식 속에서 자유롭게 탐구해 볼 수 있었다. 이는 자아 정체성 확립을 통한 실직을 극복하는데 있어서 현실을 직면하고 문제해결 능력 향상에 영향을 주었다고 생각한다. 이와 같은 결과를 기초로 하는데 있어 본 연구의 한계점 및 제언은 다음과 같다. 실직자의 대상이 한정적이고, 소 인원을 대상으로 한 미술치료 적용으로 근로의욕 고취효과를 객관화하는데 한계점를 둔다. 또한 기관의 사정으로 많은 회기의 프로그램 적용을 실시하지 못한 한계점도 밝힌다. 다음 연구에서는 많은 실직 대상자와 충분한 프로그램이 실시로 연구가 이루어져야 할 것이다. 또한 실직의 예방적 측면과 근로자들의 정신건강을 위해 많은 산업체 및 단체에서 정기적인 미술치료 프로그램이 실시되어야 한다고 제언한다. Since the 1997 financial crisis of Korea, a number of bankruptcies and a high degree of unemployment have brought a vital damage to national and individual economies as well as have caused psychological shrinkage of social members. Thus, among solutions for the unemployed, this study examines an effect of Mandala art therapy on the promotion of the unemployed's will to work. In order to increase the unemployed's will to work, the study sets the following specific objectives. First, it is to recover positive thinking and psychological comfort of the long-term unemployed through Mandala art therapy. Second, it is to help them find positive energy in each individual mind and promote their will to work through an inner meditation of Mandala experiences. Third, it is to set self-identity by clarifying consciousness through Mandala art therapy which uses traditional designs. With those aims, the study made a team consisting of 3 males and 2 females who are recommended by a Wonju guardian institution for self-support. This art therapy program has been held for 12 weeks from August 16 to November 8, 2002, which contains one preparatory meeting, 10 times of art therapies for each 60 minutes and one exhibition. In addition, I took interviews with all participants after 12 meetings of this program in order to analyze their changes in psychology and attitude. The program has been executed by myself in the boundary of my own plan. The main results of it are like followings. First, as participants have began to overcome the early psychological uncertainty and dolefulness and to be calm, it showed their changes from shrunken and passive attitude to positive behavior. This can be regarded as an impact on motivations for promoting their will to work. Second, participants could find out new energy for positive life by examining their images through Mandala experiences. It shows that Mandala therapy affects the adaptation of new reality in front of them and the positive change of their lives. Third, participants could freely investigate their confused identities, caused by unemployment, in national collective unconsciousness with using Korea's traditional patterns. This brought an improvement of resolving problems and confronting reality to overcome unemployment through setting their self-identities. Based on the above results, this study shows the following limits and suggestions. Since the participants, among the unemployed, in the program are restricted in small numbers, it has a limit to objectify the effects of promoting the unemployed's will to work. It should be mentioned here that some meetings of the program could not be held due to the institution's situation. Any next study on it needs to deal with sufficient participants and programs. Furthermore, I suggest that long-term picture therapy programs should be held in many companies and institutions in order to prevent unemployment and to protect psychological health of the employed.