문맥압항진증 유도 돼지 모델에서 경경정맥 간내 문맥정맥 단락(TIPS) 내외 조직학적 변화에 관한 연구

류정규 경희대학교 대학원 2001 국내석사

Purpose To induce chronic portal hypertension in swine models using n-butyl-2-cyanoacrylate(NBCA) and to evaluate the changes of histopathologic findings with the degree of stenosis in TIPS tract created in pigs at different follow-up periods between 2 -6 weeks. Materials and Methods NBCA was used to induce chronic portal hypertension in two domestic swines via percutaneous transhepatic approach. TIPS tracts were applied in these two pigs after two weeks. Another 7 swine models were used for the evaluation of serial( 2, 4, 6 weeks, two pigs each) histopathologic changes in TIPS tract, after inducing portal hypertension with NBCA via tranjugular approach. Portal angiogram with portal pressure measurement were also done and the degree of luminal narrowing was compared with one another. The site of narrowing or stenosis in shunt tract and the histologic composition of pseudointimal hyperplasia(its difference between intimal hyperplasia) were evaluated. Results The mean portal venous pressure in two swines of preliminary study showed 16cmH2O, 28.5cmH2O, and 31cmH2O for pre-embolization, post-embolization and 2 weeks follow-up, respectively. After creating TIPS tracts, the mean portal venous pressure decreased to the level of 18cmH2O. In other 7 pigs of main study models at different follow-up periods of 2, 4, 6 weeks, the mean portal vein pressure for pre-embolization, post-embolization and post-TIPS insertion were 13.15 3.41cmH2O, 26.78 5.80cmH2O and 15.5 3.35cmH2O(p<0.01), respectively. Near complete occlusion of all TIPS tracts(mean 76.00% 5.29% of shunt lumen) were observed, except one model at 2 weeks follow-up. The stenotic or narrowing site located mainly at parenchymal shunt tract rather than either portal vein or hepatic vein site. The fundamental cause of these obstruction and stenosis of TIPS tract in swines was turned out to be the pseudointimal hyperplasia composed of granulation tissue of collagen, mesenchymal cells and some inflammatory cells. Conclusion We could create portal hypertension of 2-weeks duration in two swine models using NBCA, a new embolic material. Also, we induced portal hypertension using NBCA in 7 pigs, created TIPS tract. In five models, complete obstruction by the pseudointimal hyperplasia of the parenchymal portion of the TIPS tract was observed from 2-weeks and severe stenosis in one. In this study, we could suggest another new embolic material for inducing portal hypertension in swine models and we think that this experiment would be an another basic method for various future studies for successful maintenance of TIPS tract.

(The) Effects of Voluntary Running on the Expression of Vascular Endothelial Growth Factor Receptors in the Mouse Hippocampus

류정규 경희대학교 대학원 2005 국내박사

홍수경보시스템을 위한 위성링크 해석의 연구

류정규 한밭大學校 情報通信專門大學院 2009 국내석사

In the 21st century, natural disasters like earthquake, flood, drought, heavy snow and tornado occur frequently around the world even in parallel with artificial disasters like fire, collapse and explosion. That is why there are increasing academic and commercial interests in disaster prevention communication that uses information and telecommunication (IT) network as social infrastructure to reduce economic loss and casualties from disasters. Based on IT technologies, the disaster prevention communication allows disaster management field authorities to take timely and proper measures by quick data collection and analysis and to reduce potential damages from disasters. This study aimed to analyze the design of satellite link by allowing for characteristics of Korean environment, Satellite Mugunghwa and VSAT system for flood warning network using satellite. Satellite telecommunication network has advantages such as easy circuit setting, very high data throughput (to send and receive even mass volume of information), relatively low risk of disaster-induced damages to facility, and nationwide coverage (available almost all over the nation). That is why it is widely used as a major network of disaster prevention communications. VSAT system generally consists of a Star Network including a hub station, Satellite Mugunghwa and a multitude of remote stations. It can provide a wide variety of data services, and has advantages such as low station cost, small size and simple installation, so that various forms of satellite network can be built to meet desired purpose and applications. In this study, VSAT system was designed for digital data communication using TDMA (inbound) and TDM (outbound) as transfer mode, and both hub and remote station were designed as a sort of satellite telecommunication station on the scale of 3.7 m and 1.2 m respectively. And the links of VSAT network were designed so that hub and remote station can transfer data efficiently according to given transfer specifications within the limit of output power and bandwidth of satellite transponders allocated across a VSAT network. Here, link margin was designed to reach 1.36 dB (inbound)/1.62 dB (outbound) respectively when hour rainfall rate amounts to 0.043 % (3.767 hours), and satellite transponder used 4.4 % of total bandwidth and 4.5 % of total electricity. So this study suggested that 36 MHz satellite transponders could comprise total 22 flood warning systems. 21세기에 접어들면서 지진, 홍수, 한발, 폭설, 강풍 등 자연재해와 화재, 붕괴, 폭발 등 인위적 재난이 전 세계적으로 빈발하면서 경제적 손실과 인명피해를 줄이기 위해 사회기반으로 정보통신망을 활용한 방재통신이 부각되고 있다. 따라서 재해관리분야에서 정보통신의 기술을 활용한 방재통신은 신속한 정보수집과 분석을 통한 적절한 초기대응으로 재해로 인한 피해를 줄일 수 있다. 본 논문은 위성을 이용한 홍수경보망을 위한 한국의 환경특성, 무궁화위성의 특성 그리고 VSAT(Very Small Aperture Terminal) 시스템의 특성을 고려하여 위성링크 설계를 해석 하였다. 위성통신망은 회선설정이 용이하고 대용량의 정보를 송수신할 수 있다는 장점을 가지며 재해 시 설비피해의 영향이 적고, 전국 대부분의 지역에서 이용 가능하다는 이점을 갖고 있어 방재통신의 주된 망으로 활용된다. VSAT 시스템은 중심지구국(Hub Station), 무궁화위성 그리고 다수의 단말지구국(Remote Station)을 포함하는 성형망(Star Network)으로 구성되고, 광범위한 데이터서비스를 제공할 수 있으며 지구국 가격이 낮고, 크기가 작고, 설치가 간단하여 사용자의 사용목적과 용도에 따라서 여러 가지 형태의 위성전송망 구성이 가능하다. VSAT 시스템은 디지털 데이터 전송용으로 인바운드(Inbound)는 TDMA (Time Division Multiple Access), 아웃바운드(Outbound)는 TDM(Time Division Multiplexing) 전송방식을 이용하며 중심국과 단말국의 크기는 각각 3.7 m, 1.2 m로 설계된 위성 통신 지구국이다. VSAT 망에서 링크설계는 VSAT 망에 할당된 위성 중계기(Satellite Transponder)의 출력전력 및 대역폭 범위 내에서 중심지구국과 단말지구국이 주어진 전송규격에 따라 정보를 효율적으로 전송할 수 있도록 설계하였다. 설계된 링크마진은 강우시간율이 0.043 % (3.767시간)일때 인바운드/아웃바운드 각각 1.36 dB/1.62 dB로 설계되어 위성중계기의 사용된 대역폭은 4.4 %이고 사용된 전력은 4.5 %이기 때문에 36 MHz 위성중계기의 경우 22개의 홍수경보시스템을 구성할 수 있음을 제시하였다.

農民的 分割地所有에 關한 理論的 硏究

유정규 (劉正奎) 建國大學校 大學院 1987 국내석사

不動産 仲介 制度 改善方案에 關한 考察

유정규 漢城大學校 不動産大學院 2009 국내석사

부동산중개업은 국민의 부동산경제활동에 있어서 가장 밀접한 연관이 있다. 따라서 부동산중개제도가 부동산업 현상에 미치는 영향은 매우 크다고 할 수 있다. 전 세계적으로 급격하게 변화하고 있는 경제환경 속에서 우리나라도 경제규모의 확대와 변화, 도시의 팽창으로 인한 도시개발사업 확대와 부동산 자본의 증대, 국민생활수준의 질적 향상. 첨단IT기술의 발달 등 국민경제의 성장이 지속되면서 부동산업의 역할과 중요성은 날로 증대되고 있는 실정이다. 이러한 추세에 따라 정부는 부동산 시장의 질적?양적 발전을 위하여 외국자본의 국내유입을 도모하고자 그동안 폐쇄적으로 운영되었던 국내 부동산서비스시장에 대한 전면 개방을 추진하였다. 또한 대내적으로는 국내부동산시장에 부동산의 증권화 및 유동화가 도입되고 부동산 투자와 개발, 관리 및 마케팅 등과 같은 새로운 투자전략이 형성되고 있다. 공인중개사는 부동산 유통시장에서 원활한 부동산 거래가 이루어지도록 서비스를 수행하는 것을 목적으로 거래부동산의 단순 알선중개 업무부터 부동산의 관리대행, 부동산의 이용, 개발, 경매, 공매 부동산의 권리분석과 취득 알선에 이르기까지 폭 넓은 업무를 행하고 있다. 이제 우리나라의 부동산 경제시장의 확대로 인해 수준 높은 부동산서비스에 대한 필요성과 외국부동산업체의 진출로인한 시장개방 등으로 부동산중개업도 높은 신뢰성 확보, 서비스수준의 향상, 전문성제고 등의 사안을 경쟁력 강화차원에서 검토하여야 하고 또한 제도적으로도 갖추어져야 할 것이다. 따라서 우리나라 부동산중개업의 현황을 분석하고 부동산중개제도의 특성을 살펴보고 개선방안을 강구하여 대안 도출을 목적으로 한다. As Korea is advancing, necessity of a quality service on realty, which takes a huge part of individual's wealth, and a state of financial turmoil caused by restructuring in realty industry, opening markets to foreign companies, moving to an information-oriented and financial centered society have demanded an improvement in real estate brokerage services. However, Korea's realty industry has not satisfied the demand. The purpose of the study is to suggest systematically practical alternatives, which are resulted from the following; The study finds problems of real estate brokerage services by analyzing the current brokerage services in Korea and their characteristics, and then looks for possible solutions for the problems. The study reviews the solutions in terms of strengthening competitiveness, which can be defined by having trustworthy real estate brokerage services, improved service quality and a high speciality. The research methods of the paper begin with understanding the concept of brokerage services, comparing and analyzing brokerage services abroad and in Korea, and examining current status of real estate brokerage service industry and environmental changes. To find problems and suggest solutions, it is widely consulted that books from inside and outside of Korea, journals, research reports, statistics, dissertations, government announcements and internet materials. This thesis consists of 5 chapters, which are the following. Chapter 1. Introduction - describing the purpose of the study, the methods and range of the study and previous study. Chapter 2. Consideration on real estate brokerage services - looking at the concept, characteristics and types of real estate brokerage services; comparing to foreign real estate brokerage services followed by analyzing. Chapter 3. Analysis of environmental changes in real estate brokerage services caused by restructuring in realty industry, opening markets to foreign companies, moving to an information-oriented and financial-centered society, and of current status in real estate brokerage service industry. Chapter 4. The problems and solutions of profession in real estate brokerage services - Identifying problems by analyzing necessity of improving the licensing system of licensed real estate agents, excessive workload, escrow system, lack of practical field education for licensed real estate agents and customer satisfaction; suggesting improvements on licensing system for licensed real estate agents, limiting the workload, having responsibility for damages, launching an integrated real estate service, training experts as solutions. Chapter 5. Conclusion - reviewing the institutional frame needed to be improved in the current real estate brokerage services; summarizing the problems and solutions; and describing researcher's the suggestions and hopes.