A 37Ch Visible Adaptive Optics System for Wavefront Compensation

이준호,Byung Tae Choi,Eung Cheol Kang,Hae Seog Kho,Ho Jung Cheon,Jae Il Lee,Joon Won Kim,Kyung Muk Lee,Sung Jin Kim,Young Cheol Lee,Young Il Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.1

A visible adaptive system was developed to compensate for phase distortions of a visible (He-Ne) laser. The visible adaptive optics (AO) system consists of 5 subsystems: a Shack-Hartmann wavefront sensor, a deformable membrane mirror of 15 mm with 37 actuators, a high-speed tip/tilt mirror of 20 mm, a position sensor and a control & display unit. The lab-developed Shack-Hartmann sensor was experimentally shown to have a measurement accuracy of better than RMS /50 at 0.6328 μm over the maximum phase distortion that the deformable mirror could generate, i.e., approximately /4. The adaptive optics system operated the deformable mirror at 10 Hz and the tip/tilt mirror at 30 Hz, which were, respectively, closed by the Shack-Hartmann sensor and the position sensor. The closed adaptive optics system was demonstrated to compensate for time-varying wavefront aberrations of PV (Peak-to-Valley) 1.2 μm with a time frequency of 1.4 Hz. The residual RMS wavefront error was shown to be smaller than 0.014 μm, i.e., /45 at 0.6328 μm.

정맥용 면역글로불린 투여 후 발생한 무균성 수막염 3례

이준호,송은경,이진아,김남희,김동호,박기원,최은화,이환종,Lee, Joon Ho,Song, Eun Kyoung,Lee, Jin A,Kim, Nam Hee,Kim, Dong Ho,Park, Ki Won,Choi, Eun Hwa,Lee, Hoan Jong 대한소아감염학회 2005 Pediatric Infection and Vaccine Vol.12 No.2

IVIG 투여에 의해 무균성 수막염은 그 기전이 밝혀지지 않았으나 IVIG 투여와 관련된 신경학적 부작용 중 가장 중한 합병증의 하나이다. 저자들은 서울대학교 어린이병원에서 2003년부터 2004년까지 3명의 환아에서 확인된 IVIG 투여와 관련된 무균성 수막염 4례를 경험하여 보고하였다. 3명의 환아는 ITP, 가와사키병, 중증 근무력증으로 기저질환은 각각 상이하였으나 기저질환에 대한 치료를 위해 모두 고용량의 IVIG를 투여받았으며, IVIG를 투여받은 후 1~2일 이내에 심한 두통과 뇌막자극 징후를 보였다. 척수액 소견상 백혈구 수는 $100/{\mu}L$ 미만에서부터 $1,000/{\mu}L$ 이상까지 다양하였으나 주로 다핵구로 구성된 척수액 백혈구 분포를 보였고(66~98%), 세균 배양검사와 장바이러스 배양과 PCR 검사에서 음성 결과를 보였다. 3명의 환아 모두 수막염 발생 2일 후까지는 증상이 호전되었으며, 후유증 및 장애가 없었다. Intravenous immune globulin(IVIG) is widely used for immune thrombocytopenic purpura (ITP), Kawasaki disease and other autoimmune neuromuscular disease. Aseptic meningitis was one of the most serious neurologic complications reported following the use of IVIG. We experienced 4 episodes of aseptic meningitis associated with IVIG usage in 3 patients from 2003 to 2004. Underlying disease of each patients was ITP, Kawasaki disease and myathenia gravis and all of them received high dose IVIG treatment for their underlying disease. Within a days, they started to complain severe headache and diagnosed meningitis by cerebrospinal fluid analysis. Cerebrospinal fluid leukocyte counts varied from 92 to over a thound per microliter with dominance of polymorphonuclear leukocytes. Microbiologic studies revealed no organisms. All of them were free from headache within 2 days and did not suffer any neurological sequelae.

2001년 경상북도에서 발생한 콜레라 유행에 관한 역학조사

이준호,이관,김준철,이상원,고운영,양병국,이종구,김문식,임현술,Lee, Jun-Ho,Lee, Kwan,Kim, Jun-Chul,Lee, Sang-Won,Go, Un-Yeong,Yang, Byung-Kuk,Lee, Jong-Koo,Kim, Moon-Sik,Lim, Hyun-Sul 대한예방의학회 2002 예방의학회지 Vol.35 No.4

Objectives : This study was carried out to investigate the cause, magnitude and transmission route of the cholera outbreak in 2001 Methods : The study population were those persons who ingested foods at the restaurant, were confirmed as cholera patients, had symptoms of diarrhea and sewed as workers at the restaurant. A questionnaire survey and microbiological examinations on the microbes isolated from rectal swabs were conducted. Of the cases, 316 food histories were surveyed by an analysis of the restaurant menu. Results : There were 139 confirmed cases of cholera reported in Korea in 2001. Of these, 104 were related to the restaurant. By region, Gyeongsangbuk-do had the highest incidence with 91 cases. Of these 91 cases, 74 had ingested foods at the restaurant, 2 were employees and 3 were secondary infection cases within the families. The results of the odds ratio analysis of the 316 persons having ingested foods at the restaurant were as follows: sandwiches 5.07 (95% CI, 1.85-14.59), soybean curd 2.45 (95% CI, 1.09-5.56), noodles 2.34 (95% CI, 1.24-4.42), steamed squid 2.01 (95% CI, 1.17-3.47) and vinegared rice 1.82 (95%, CI, 1.08-3.09). It was certain the restaurant in question was the cause of the 2001 outbreak. Conclusions : We suspected that more than one restaurant employee contaminated foods served at the restaurant. In addition, eating raw fishes purchased at the Pohang Fisheries infected the employees of the restaurant. There is a possibility that these raw fishes were themselves contaminated by cholera bacilli in the sea.

Experimental Evaluation of Q-Parameterization Control for the Imbalance Compensation of Magnetic Bearing Syatem

이준호,김현기,이정석,이기서,Lee, Jun-Ho,Kim, Hyeon-Gi,Lee, Jeong-Seok,Lee, Gi-Seo 대한전기학회 1999 전기학회논문지A Vol.48 No.3

This paper utilizes the method of Q-parameterization control to design a controller which solves the problem of imbalance in magnetic bearing systems. There are two methods to solve this problem using feedback controal. The first method is to compensate for the imbalance forces by generating opposing forces on the bearing surface (imbalance compensation). The second method is to make the rotor rotate around its axis of inertia (automatic balancing);in this case no imbalance forces will be generated. In this paper we deal with only imbalance compensation. The free parameter of the Q-parameterization controller is chosen such that these goals are achieved. After the introduction of a model of the magnetic bearing system, we explain the Q-parameterization controller design of the magnetic bearing system with emphasis on the rejection of sinusoidal disturbance for imbalance compensation design. The design objectives are formulated as a linear equations in the controller free paramete Q. Finally, simulation and experimental results are presented and showed the robustness and effectiveness of the proposed controllers.

하천복원을 위한 하천평가기법의 적용성 연구

이준호,강태호,성영두,윤세의,Lee. Joon-Ho,Kang. Tae-Ho,Sung. Young-Du,Yoon. Sei-Eei 한국방재학회 2003 한국방재학회논문집 Vol.3 No.4

본 연구의 목적은 하천 관리자들에게 하천의 자연성 증진의 중요성을 이해시키고, 하천을 자연스러운 상태로 되돌리는 과정에서 하천이 처한 상황에 대한 진단과 처방을 위한 하천자연도 평가 방법을 개발하는 것이다. 본 연구에서는 하천의 자연도평가와 그 적용성의 확인을 위해 수로의 발달, 종방향, 횡방향, 하상구조, 저수로변 구조, 하천주변, 수질 등 7가지 자연도 평가기법의 항목을 제안하였다. 자연도평가를 위해 복하천을 대상하천으로 선정하였다. 복하천에서 자연도지수는 <TEX>$2.2{\sim}3.8$</TEX>정도였고, 평균지수는 3.1로 대부분이 3등급을 나타내었다. 7개 지수 중에서 횡단면이 가장 높은 등급이었고, 수로의 발달이 가장 낮은 등급이었다. 본 연구에서는 하천의 자연도 등급을 통해 하천의 자연성을 파악할 수 있었으며, 복원해야 할 하천의 선택과 훼손된 하천의 복원구간 및 방법을 결정할 수 있었다. The purpose of this study was to develop a new method for evaluation of stream naturalness in order to promote stream managers` understanding on importance of improving stream naturalness, and in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. In order to analyze the evaluation method of stream naturalness and its applicability to streams, stream naturalness index(SNI) which has seven factors such as channel development, longitudinal profile, lateral section, stream bed structure, low flow channel structure, stream surroundings and water quality was suggested in this paper. For case studies, Bokha stream was selected for the evaluation of stream naturalness. At the Bokha stream, the scores of SNI factors were in range of <TEX>$2.2{\sim}3.8$</TEX>, and the average of SNI was 3.1, and the most frequent grade of SNI factors was grade 3. Among the 7 factors, the best was lateral section, and the worst was channel development. In this study, SNI grade can represent the characteristics of stream naturalness well and select the streams which will be restored, and can also decide the segment and the method of restoration for deteriorated streams.

Vibrio vulnificus에 의한 감염성 근염의 자기공명영상소견: 증례 보고

이준호,나재범,Lee, Jun-Ho,Na, Jae-Beom 대한영상의학회 2003 대한영상의학회지 Vol.48 No.3

비브리오 패혈증은 간질환의 병력이 있는 해안가 주민에서 해산물을 섭취한 후 발생하며, 대부분 피부, 피하지방과 근막으로 염증이 생기며 하지로부터 몸통과 상지 쪽으로 퍼져나가며 패혈증으로 사망하게 된다.비브리오 패혈증의 감염성 근염은 매우 드물고, 자기공명영상 소견은 보고된 적이 없다. 저자들은 Vibrio vulnificus에 의한 양측하지의 감염성 근염 증례를 1예 경험하였기에 자기공명영상 소견과 함께 보고하고자 한다. Vibrio vulnificus infection is a fatal disease occurring after the consumption of seafood in patients with underlying liver disease. Inflammation of the skin, subcutanous fat and fascia disseminates from the lower extremity to the trunk and upper extremity Infectious myositis caused by vibrio vulnificus is rare, and its MR imaging findings have not been reported. We report these in a case of infectious myositis caused by vibrio vulnificus involving both lower extremities.

수막 혈관주위세포종의 임상상, 치료 및 장기 추적 결과

이준호,황승균,곽호신,백선하,김동규,김현집,정희원,Lee, June-Ho,Hwang, Sung-Kyun,Gwak, Ho-Shin,Paek, Sun Ha,Kim, Dong Gyu,Kim, Hyun Jib,Jung, Hee-Won 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.7

Objectives : Meningeal hemangiopericytoma is a rare tumor. Clinical and radiological features are similar to those of an ordinary meningioma. But its biological behavior is quite different from those of a meningioma as it brings profuse bleeding in the operation field, frequent recurrence and metastasis to other systemic organs even in the case of gross total resection. In order to find out the prognostic factors and to compare longterm outcome after various treatment modalities, the authors reviewed consecutive 20 operated cases of meningeal hemangiopericytoma to characterize their clinical features, surgical outcomes and effectiveness of the radiation therapy. Methods : Twenty patients with a hemangiopericytoma were treated between 1982 and 1999 in our department. They are composed of 13 patients of hemangiopericytoma and 7 patients who were initially diagnosed as angioblastic type meningioma and then confirmed as a hemangiopericytoma after review of their previous histopathology slides. The mean follow-up period was 99 months(1-256 months). The long-term outcomes after various treatment modalities were evaluated according to recurrence-free survival and image follow-up. Recurrence-free survival curves are compared between the patient groups according to the extent of removal and radiation therapy. Results : There were 10 cases of recurrence and 4 cases of distant metastases ; lung, liver and femur(2 cases) respectively. The 5-year recurrence rate was 37%, while the 10-year recurrence rose to 77%. There was also statistically significant difference of median recurrence-free survival between the completely-resected group(Simpson grade 1 or 2) and partially-resected group(Simpson grade 3 or 4 or 5) ; 137 months compared to 47 months, respectively(p=0.009). The median recurrence-free period after subtotal resection of tumor and postoperative radiotherapy was 47 months compared to 117 months of the patients who underwent gross total resection of tumor and did not receive radiotherapy. But radiation therapy alone did not show significant difference in recurrence-free survival. Marked tumor volume reduction and easy removal of tumors without bleeding were found in 2 recurred cases. Conclusion : The extent of tumor resection and presence of metastasis are the most important factors related to long-term outcome of the patients with hemangiopericytoma. Radiation therapy after the first operation did not have a role in extending the recurrence-free survival, but it affected favorably to decrease the size of residual mass and intraoperative bleeding during the second operation.

확대 영상의 몽롱화 현상을 제거하기 위한 보간 알고리즘 연구

이준호,Lee, Jun-Ho 한국생산제조학회 2010 한국생산제조학회지 Vol.25 No.6

This paper analyzes the problems that occurred in the magnification process for a fine input image and investigates a method to improve the blurring of magnified image. This paper applies a curve interpolation algorithm in CAD/CAM for the same test images with the existing image algorithm in order to improve the blurring of magnified image. As a result, the nearest neighbor interpolation, which is the most frequently applied algorithm for the existing image interpolation algorithm, shows that the identification of a magnified image is not possible. Therefore, this study examines an interpolation of gray-level data by applying a low-pass spatial filter and verifies that a bilinear interpolation presents a lack of property that accentuates the boundary of the image where the image is largely changed. The periodic B-spline interpolation algorithm used for curve interpolation in CAD/CAM can remove the blurring but shows a problem of obscuration, and the Ferguson' curve interpolation algorithm shows a more sharpened image than that of the periodic B-spline algorithm. For the future study, hereafter, this study will develop an interpolation algorithm that has an excellent improvement for the boundary of the image and continuous and flexible property by using the NURBS, Ferguson' complex surface, and Bezier surface used in CAD/CAM engineering based on the results of this study.

광학 설계 및 해석 프로그램인 ZEMAX에 대한 소개

이준호,Lee, Jun-Ho 한국광학회 2006 광학과 기술 Vol.10 No.4

복합 슬릿-마찰 감쇠장치가 적용된 철근 콘크리트 특수 모멘트 저항골조의 내진성능 평가

이준호,김기철,김진구,Lee, Joon-Ho,Kim, Gee-Cheol,Kim, Jin-Koo 한국공간구조학회 2017 한국공간구조학회지 Vol.17 No.4

This study develops a new hybrid passive energy dissipation device for seismic rehabilitation of an existing structure. The device is composed of a friction damper combined with a steel plate with vertical slits as a hysteretic damper. Analytical model is developed for the device, and the capacity of the hybrid device to satisfy a given target performance is determined based on the ASCE/SEI 7-10 process. The effect of the device is verified by nonlinear dynamic analyses using seven earthquake records. The analysis results show that the dissipated inelastic energy is concentrated on the hybrid damper and the maximum interstory drift of the SMRF with damping system satisfies the requirement of the current code.