貿易關係法의 새로운 定立方向

李廛三,文哲漢,吳元奭,朴南圭 청주대학교 기업경영학연구소 1986 經營學論集 Vol.8 No.-

Maximum Ratio Transmission 기법의 MIMO 다중경로 페이딩 채널로의 확장

이경규,이원철,신요안 崇實大學校 生産技術硏究所 2001 論文集 Vol.31 No.-

To effectively improve capacity on fading channels in the third generation and beyond mobile communication systems that require high quality and capacity, spatial diversity schemes utilizing MIMO (Multi-Input Multi-Output) concepts have been identified as an efficient way of improving the capacity without expanding the bandwidth. Among various MIMO spatial diversity schemes, MRT (Maximum Ratio Transmission) which maximizes signal-to-noise ratio at the reception has been recently proposed. In this paper, we extend the conventional MRT scheme which is restricted to flat fading channels to MIMO multipath fading channels, and analyze the bit error rate performance.

MIMO 시스템에서의 APP 디코딩의 성능

이경규,김산해,김홍철,이원철,신요안 崇實大學校 生産技術硏究所 2002 論文集 Vol.32 No.-

MIMO (multi-input multi-output) systems can achieve high data capacity and high data rate in the third generation (3G) or beyond-3G mobile communication systems. To effectively improve the performance of MIMO systems, new detection schemes which can mitigate mutual interferences from multiple transmit antennas, are highly required. In this paper, we consider a posteriori probability (APP) type detection schemes for the MIMO systems, and compare with other sub-optimal detection schemes based on zero forcing (ZF) and minimum mean square error (MMSE) - ordered successive interference cancellation (OSIC). Simulation results show that the APP outperforms ZF-OSIC and MMSE-OSIC, while the performance discrepancy becomes smaller as the number of receive antennas increases.

單純보의 移動支點에 摩擦係數를 考慮한 처짐, 처짐角 및 굽힘 모멘트의 影響에 對한 考察

李圭遠 大田工業高等專門學校 1968 論文集 Vol.3 No.-

We usually design in disregard of a frictional force in Roller Support of simple beam. But there arises the horizontal friction force, owing to the infiltration of water and dusts, with the lapse of time. I am going to induce this thesis, with a consideration for the formula of the elastic curve and the coeficient of friction on the deflection, the deflection angle and the bending Moment, by making use of the general idea that the physical laws, that is, Normal reaction is in proportion to the horizontal force. In the general formula, induced like this, 1 got chart2 and chart3, by obtaining the maximum deflection, the maximum deflection angle and the maximum bending Moment. As these charts show, we should design with a dynamic reckoning that the coefficient of friction have to be considered, by means of choosing the safety and suitable data.

안성시 간이급수시설에 대한 연구

이웅,이상수,이상훈,유원석,박규홍 중앙대학교 건설환경연구소 2001 環境科學硏究 Vol.12 No.1

The condition of operation and maintenance for selected small water systems in An Sung was surveyed. Eight small water systems were selected among one hundred ninety systems in An Sung. The environment, especially contaminant source around the systems was reevaluated. Questionnaire was also conducted to find out the recognition of inhabitants and/or managers for the operational difficulty and management problems of the systems. Twenty percent of the respondents was not satisfied with the flow rates of the supplied water and 16% with the water quality. Eighty percent of the respondents wanted to enhance the existing treatment facilities by installing additional filtration and/or disinfection process. Only 13% of the managers of the small systems were regularly paid. The limit of their role and responsibility seemed unclear and the development of practical and responsible management program for small water systems is expected.

오염토양 정화를 위한 계면활성제 선정기법에 관한 연구

박규홍,이재원 中央大學校 建設環境硏究所 1997 環境科學硏究 Vol.8 No.-

The screening test was performed to select the proper surfactant and various operation conditions in applying surfactant flushing to in-situ remediation. Contaminants to be removed were B.T.E.X(Benzene, Toluene, Ethylbenzene. p-Xylene, m-Xylene, o-Xylene) and anionic SDS(Sodium Dodecyl Sulfate), nonionic NEODOLⓡ 25-3, and nonionic SOFTANOLⓡ -90 were used as surfactants. Various experiments including CMC(Critical Micelle Concentration) test MSR(Molar Solubilization Ratio) test, solubility test, sorption test of B.T.E.X, sorption test of surfactant, and permeability test were conducted to optimize treatment condition which are applicable to in-situ remediation salinity control or electrolyte control using ethyl alcohol, hydrotrope, and electrolyte solution was also manipulated. Several properties of aqueous solutions of the surfactants and additives were used in evaluating their suitability. As a result, the main factors for the improvement of the removal efficiency were the retention time and permeability between organic contaminants and flushing solution.

인공망막칩과 형상기억합금을 이용한 평활 안구운동시스템 구현

김원철,김현수,박종호,박대식,이민호,신장규 한국뇌학회 2001 한국뇌학회지 Vol.1 No.2

본 논문에서는 인간의 평활 추적안구운동을 모방하는 능동시각시스템(active vision system)을 구현하였다. 평활 추적 안구운동을 모방하는 능동시각시스템을 구현하기 위해 인간의 안구운동 중에 관찰되는 신경생리학적인 특징들을 이해하고, 다양한 안구운동 중에서 평활 추적안구운동 중에 관찰되는 중측관자(medial temporal) 세포의 역할을 자기조직화 형상지도(self-organizing feature map)와 승자독점(winner take all)을 이용하여 구현하였다. 회전속도계 궤환 모델(tachometer feedback model)로 중상측관자(medial superior temporal) 세포의 역할을 모델하였다. 그리고 인공망막칩으로 인공 안구를 구성하고 형상기억합금 구동기(actuator)를 이용하여 인공 안근육을 구성하여, 빛의 밝기 변화인 윤곽(edge) 정보에 반응하는 인공 안구모형을 제작하였으며, 실험을 통하여 시스템의 동작성능을 보였다. In this paper, we proposed a model of smooth pursuit eye movement, and developed a human-like active vision system using a retina chip and a shape memory alloy actuator. The model of smooth pursuit eye movement is to imitate the role of MT and MST area of human brain in smooth pursuit eye movements. We fabricated the 8×8 retina chip for the edge detection. The developed retina chip is an image sensor to extract edge information and the shape memory alloy actuator is a driver to imitate the role of eye muscles to follow a moving object.

차아염소산나트륨 처리와 멸균법이 근관 치료용 파일의 부식에 미치는 영향에 관한 연구

양원경,라윤식,이영규,손호현,김미리 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.2

근관 치료시 많이 사용되고 있는 K-flex S-S 파일 (Maillefer, USA)과 Profile Ni-Ti 파일 (Maillefer, USA), K-3 Ni-Ti파일 (SybronEndo, USA)의 부식 정도를 보기 위하여 총 360개의 20번 file을 1) 멸균소독 방법 (고압가열멸균소독, E-O gas 소독) ,2) 근관세척 액 (5.25% 차아염소산나트륨, 생리식염수) ,3) 멸균소독 횟수 (1, 5, 10회 ) 에 따라 36개 실험군으로 나누었다. 각각의 파일을 각 군별로 처리한 뒤, 세 명의 검사자가 광학 현미경 하에서 25배의 배율로 검사하여 0; 부식 없음, 1; 경도의 부식, 2; 중등도의 부식, 3; 심한 부식으로 점수화 하였다. 심한 부식을 보이는 파일의 표면은 SEM으로 관찰하였고 Kruskal-Wallis test (p < 0.05)를 이용하여 통계 분석 처리하여 차아염소산나트륨 접촉 여부와 멸균소독 방법의 차이에 의한 부식 정도를 평가하였다. 그 결과 고압가열멸균소독을 10회 시행한 파일은 통계적으로 유의한 차이를 보여 부식 정도가 심하였고, 1회나 5회 고압가열멸균소독을 시행한 파일과 E-O 가스로 소독한 파일들은 부식의 정도가 경미하여 통계적으로 유의하지 않았다. 차아염소산나트륨 접촉 여부와 제조사 혹은 파일 재료에 따른 유의성 있는 차이는 없었다 A variety files made of stainless steel (S-S) or nickel-titanium (Ni-Ti) are used during endodontic treatment. The purpose of tt)is study was to evaluate the corrosion susceptibility of S-S and Ni-Ti endodontic files. Three brands of files were used for this study: K-flex S-S files (Maillefer, USA), Profile Ni-Ti files (Maillefer, USA), K-3 Ni-Ti files (SybronEndo. USA). 120 files of each brands (21mm, ISO size #20) were divided into 12 groups according to 1) sterilization methods using Autoclave or Ethylene Oxide (E-O) gas, 2) Irrigation solutions using 5.25% NaOCl or Saline, 3) the number of sterilization (1, 5, 10 times), After above procedures, each of the files was inspected by three examiners with a light microscope and camera at X25. Each file was judged and ranked according to the following criteria: 0;, no corrosion, 1; mild corrosion, 2; moderate corrosion, and 3; severe corrosion. The files of high score were examined under the Scanning Electron Microscope. Data were statistically analyzed with the Kruskal-Wallis test (p < 0.05). Most of the ten time-autoclaved files had showed mild to moderate corrosion. But, one or five time-autoclaved files did not show corrosive surface. NaOCl treatment and E-O gas sterilization did not influence on corrosion. There was a significant difference in corrosion susceptibility between sterilization methods and the number of autoclaving. However, there was no significant difference between brands and file materials.

Pyrantel Pamoate (Combantrin)에 依한 蛔蟲 및 鉤蟲感染의 集團治療

徐丙卨,朴定圭,趙昇烈,姜信榮,魚光本,康世喆,李源宰,李正雨,黃邱一 中央醫學社 1972 中央醫學 Vol.23 No.6

The mass treatment trial of pyrantel pamoate on Ascaris lumbricoides and Ancylostoma duodenale infections was carried out to school-children and inhabitants in rural areas in the central part of Korea. Pyrantel pamoate ("Combantrin") tablet (123 mg base) was administered as a single dose of 10. 0 mg per kg. body weight to a total of 4,198 Ascaris infected cases selected out of 4,436 (41. 6%) positives, who were screened from the total 10,660 collected stool specimens. Of these, only 3,169. cases were followed up after treatment to provide an analysis in this study. Incidentally 161 cases with concomittently infected hookworm were also subjected to assess the efficacy of pyrantel pamoate against A. duodenale. The egg negative conversion rate on A. lumbricoides was 95.3%, and on A. duodenale, 97.5% four weeks following treatment. In failed cases, the egg reduction rates on both of the infections were 97.6% and 97.3% respectively. No side effects and no problem in drug administration were demonstrated. It is concluded that this study confirms the high efficacy of pyrantel pamoate in the treatment of Ascaris lumbricoides and Ancylostoma duodenale infections and also proves the acceptability and safety of this drug in the mass treatment of ascariasis in a population with relatively high worm burden.

IMT-2000 위성통신 시스템에서 폐쇄루프 전송 다이버시티 기법의 성능 분석

오관명,김학성,김산해,이경규,이원철,신요안 崇實大學校 2000 論文集 Vol.30 No.1

In this paper, we apply a close loop transmit diversity scheme to IMT-2000 satellite systems, and investigate the performance of the scheme in both ideal and more realistic situations. We verify that the performance of the closed loop transmit diversity scheme is quite sensitive to errors in feedback information. However, we also show that the number of quantization bits for feedback information does not significantly affect the system performance when considering the feedback of phase information only. In addition, 2-bit quantized system achieves the better performance than 4-bit quantized system in terms of slot error rate.