역위매복된 상악 중절치의 외과적 노출과 교정력을 이용한 증례보고

최형준,최병재,김재윤,이제호 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.3

Inverted maxillary incisor is a state in which the maxillary incisor rotates to the upward position. The present report provides two examples of correction of inverted maxillary incisors with surgical intervention & orthodontic appliance. Through surgical exposure & direct bonding of lingual button, the central incisor were brought into proper eruption path with elastic traction. The case 1 & 2 were both treated successfully. The results showed the good position of treated teeth and satisfactory esthetics and adequate width of keratinized gingiva were achieved. Careful differential diagnosis procedure is needed in order to avoid dissatisfactory rusults and the treatment approaches taken in this case report provided an esthetic and functional results.

돼지 신장세포(PK15)의 이종이식 거부반응에 대한 재조합 IL-18의 영향

최연실,김은미,김영관,박상연,심정현,윤도영,강형식,명평근 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.1

Various cytokines including IL-1β, IL-2, IL-4, IL-10, IL-12p40, IFN-γ, and TNF-α have been recently reported to play important roles in both host and donor cell activations during xenotransplantation. Interleukin (IL)-18, a proinflammatory cytokine, can induce IL-4 and IL-13 production in T cells, NK cells, B cells, mast cells, and basophils. IL-18 has the capacity to stimulate innate immunity and both Th1-and Th2- mediated responses, but little is known to involve in the xenograft rejection. In order to investigate the role of IL-18 in xenograft rejection, we transplanted the pig kidney (PK15) cells to C57BL/6 mouse with or without intraperitoneal injection of mouse recombinatant IL-18. It was analyzed the population of T cell, B cell and NK cell in the mice transplanted with PK 15 cells and recombinant IL-18 by flow cytometry. We found that splenic CD3+ T cells were increased in mice injected PK15 cells with recombinant IL-18. These results suggest that recombinant IL-18 is critical in the xenograft rejection by increasing T cell population of the recipients.

LDPC부호화를 적용한 영상통신시스템설계

최태식,공형윤,최원호 울산대학교 2001 공학연구논문집 Vol.32 No.1

다양한 멀티미디어 통신이 발달함에 따라 채널부호화를 사용하여 오류를 정정하는 기술이 발달되어 왔다. 본 논문에서는 압축영상의 전송에서 LDPC 부호화를 이용하여 영상통신채널에서의 오류를 복원하고, 영상을 재구성할 수 있는 영상통신시스템을 제안한다. 제안된 영상통신시스템은 패리티검사행렬을 사용하여 가장 많은 오류를 발생하는 열과 가장적은 오류를 발생하는 열을 교환하는 방식을 사용하였고, 가우시안 노이즈를 가지는 통신채널의 신호 대 잡음비는 0dB에서 4dB의 범위로 설정하였다. 패리티 검사 행렬이 작은 경우 제시한 교환 방식을 사용하였을 때 사용하지 않은 경우보다 BER 성능이 우수함을 확인하였으며, 영상을 재구성한 경우에도 PSNR 성능이 우수함을 확인할 수 있었다. As a various multimedia communication has been developed, the error correction technique using the coding method was improved. In this paper, an image communication system using the LDPC decoding method for restoring the error and reconstructing the image in the image compression transmission is proposed. The proposed system has a parity check matrix that can alternate the least occurring error column with the most occurring error column. The signal to noise ratio of a communication channel with the gaussian noise was determined the range between 0dB 4dB. When a parity check matrix was a small size, the system's BER efficiency with the parity check alternating method was better than the parity check without it. Also in reconstructing image, the proposed system's PSNR efficiency was superior to system without alternating method.

PC U형의 단면을 사용한 포스트텐션된 넓은 보-기둥 내부접합부의 비탄성 거동

최윤철,임재형,문정호,이리형,권기혁 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

Post-tensioned precast concrete system(PPS) consists of U-shaped precast wide beams and concrete columns. The continuity of beam-column joint is provided with the topping concrete on the PC shell beam and post-tensioning. The purpose of this paper is to evaluate the response of PPS interior beam-column joint subjected to cyclic lateral loading. To this end, the experimental investigation was performed with three half-scale specimens of interior connection. The design parameter is the ratio of beam width to column width. Test results showed that cracks were distributed well and plastic hinges spread toward midspan without any significant degradation of strength and ductility. And the specimens sufficiently resisted up to the limiting drift ratio of 0.035 given by ACI of acceptance criteria for concrete special moment frames.

측면충돌시 차체의 내장 패딩재가 승객손상에 미치는 영향

崔亨然,申宰浩 弘益大學校 科學技術硏究所 1995 科學技術硏究論文集 Vol.6 No.-

NHTSA asks all passenger cars which would be on sale in US to pass the FMVSS 214 side impact test from 1996. According to the test regulations, moving deformable barrier strikes the stationary vehicle at 33.5mph with 27 degree inclined angles, which represents the perpendicular impact of 30mph on the side part of the moving vehicle with 15mph speed. During the test, two dummies are loaded on the front and back seats of the impact side to measure the acceleration histories of thoracic and pelvic regions. From the injury criterion of the regulation, peak acceleration thresholds are set at 85g and 130g for the thorax and pelvis prespectively. In comparison with the front impact accident, in which large amount of energy is absorbed by collapse of the structural parts such as engine room, side impact accident has much more chances in injury because of the limited space between the occupants and the doors. In order to protect the occupants more effectively, reducing the impact velocity with stiffened structures or introducing the energy absorbing paddings between occupants and the doors have been proposed. In this study, the effects of padding on the occupant injury level due to the side impact has been analyzed using finite element method. The density, thickness, and size of the paddings are chosen as the design parameters. Finite element analysis was performed using the PAM-CRASH? program and the model includes vehicle structures, side impact dummy, and the moving deformable barrier.

한의진단명과 진단요건의 표준화 연구 III : 3차년도 연구결과 보고

최선미,양기상,최승훈,박경모,박종현,심범상,김성우,노석선,이인선,정진홍,이진용,김달래,임형호,김윤범,박성식,송태원,김종우,이승기,최윤정,신순식 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

The diagnostic requirements were suggested and explained regarding the systems of differentiation of symptoms and signs in the third year study of standardization and unification of the terms and conditions used for diagnosis in oriental medicine. The systems were as follows : - analyzing and differentiating of epidemic febrile disease - analyzing and differentiating in accordance with the Sasang constitution medicine based on four-type recognition - differentiation of disease according to pathological changes of Chong and Ren channels - standards for diagnosis of women's disease - standards for diagnosis of children's disease - standards for diagnosis of motor and sensor disturbance (-muscle. born, joint, etc.) - standards for diagnosis of neuropsychiatric disease - standards for diagnosis of five sense organ disease - standards for diagnosis of external disease The indivisual diagnosis pattern was arranged by the diagnostic requirements in the following order : another name, notion of diagnosis pattern, index of differentiation of symptoms and signs, the main point of diagnosis, analysis of diagnosis pattern, discrimination of diagnosis pattern, prognosis, a way of curing a disease, prescription, herbs in common use, disease appearing the diagnosis pattern, documents. The standards for diagnosis of each disease was arranged by the diagnostic requirements in the following order : another name, notion of disease, the main point of diagnosis, analyzing and differentiating of disease, analysis of disease, discrimination of disease, prognosis, a way of curing and prescription of disease, disease in western medicine appearing the disease in oriental medicine, documents.

무시멘트형 인공고관절 대치술후 대퇴골에 발생하는 응력방패현상에 관한 유한요소해석

최형연 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

Clinically, proximal bone resorption in the femur is frequently seen postoperatively on the follow up X-rays after total hip replacement (THR). The stress shielding on the medial proximal region of femoral bone is known as a main cause of the resorption phenomina. In order to understand the mechanism of stress shielding and bone resorption, stress analysis is performed by finite element method. We developed two and three dimensional finite element model of cementless THR. The two dimensional model is proposed with side plate element, whereby the three dimensional structural integrity of the bone can be accounted for. Thereby, the complex geometry of femoral bone and artificial stem can be simplified. The three dimensional analysis is also performed for more universal validity. The subject of this article is the development and application of this two an three dimensional finite element models to study the stress shielding phenomina on femur after THR. The results of this study indicates that stress distributions from finite element analysis of two and three dimensional models well explain the stress shielding phenomina.

3-차원 블록인터리버기법의 터보코드를 이용한 영상통신시스템설계

최태식,공형윤,최원호 울산대학교 2001 공학연구논문집 Vol.32 No.1

본 논문에서는 3-차원 블록인터리버기법의 터보코드를 사용하여 무선 통신 환경 하에서 효과적으로 전송할 수 있는 영상 통신 시스템을 제안한다. 웨이브릿 변환과 벡터양자화를 영상의 압축알고리즘에 사용하였으며, 무선통신시스템의 코딩방식 중 하나인 터보코드를 사용하여 압축영상데이터의 통신에 사용하였다. 터보코드의 성능은 데이터율, 부호기의 구속장의 길이, 복호 방식, 순환복호의 횟수, 인터리버의 종류 및 블록크기에 의존되어 진다. 같은 비트 크기에서의 2차원 블록인터리버보다 비트간의 거리를 크게 하는 3차원 인터리빙알고리즘을 적용한 시스템이 영상통신에서 높은 성능을 얻었다. 컴퓨터 시뮬레이션을 이용하여 3차원 블록인터리버의 성능을 압축된 영상과 가우시안 잡음 채널 환경 하에서 비교분석 하였다. In this paper, an image communication system that can effectively work in wireless communication environment is proposed. The wavelet transform and the vector quantization are used to the compress images. The turbo code that is one of the coding methods in wireless communication is used for the compressed image data communication. The efficiency of turbo code depends on the data rate, the constraint length, the decoding algorithm, the number of decoding iteration, the type of interleavers and the block size. The system with 3-D interleaving algorithm whose bit distance is longer than the 2-D block interleaver in the same size had the higher performance in image transmission. To verify the performance of the proposed method, computer simulation was performed in Gaussian noise model.

인체 경추부의 유한요소 모델링

최형연,엄홍원 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.1

The cervical is located between the human head and torso and serves two important anatomical functions. It allows for mobility between the head and the lower body parts while protecting spinal code. The cervical spine is quite vulnerable to external impact during automobile collision. For example, a sudden forward/rearward bending motion of passenger head may cause severe nerve damage. Although such cervical spine damage caused by non-contact-type forces during automobile accident usually does not involve bony fracture, the resulting injury often entails long-term pain and discomfort. In general, finding causes for the cervical spine injury through clinical investigation is very difficult undertaking. There have been numerous experimental as well as analytical studies to date for elucidating relevant factors. In particular, various simulation methods such as finite element method have been utilized to look into injury mechanisms involved. The main advantage of the simulation techniques is that a wide variety of loads and injury causing conditions can be designed and applied as opposed to clinical tests in which inherent limits on test conditions exist. A finite element model of human cervical spine based on anatomical geometry and material properties of the important elements such as vertebrae, discs, ligaments, and muscles is developed. This model can be used for understanding and predicting potential cervical injury mechanisms as well as for designing protective devices.

순수 Titanium주조체의 기계적 성질에 미치는 소둔온도와 유지시간의 영향

윤일,김형일,최석규 大韓齒科器材學會 1993 대한치과재료학회지 Vol.20 No.2

The effect of annealing temperature and holding time on the mechanical properties of pure titanium castings was investigated by means of microhardness test, compression test, microscopic observation, and EDS. Casting process was carried out under argon gas and the heat treatment was carried out under air. The results were as follows : 1. The mechanical properties of the specimens heat-treated at 500, 750℃ were slightly increased, but those of specimen heat-treated at 1,000℃ were remarkably increased by prolonged holding time. 2. The microstructures of specimens heat-treated at 500, 750℃ were bluntly serrated α structure, but that of specimen heat-treated at 1000℃ showed the mixture of acicular α and platelike α structures with a great number of fine precipitates. 4. The surface reaction layer was gradually thinned away by prolonged holding time at 1,000℃, Al and Si elements of the surface reaction layer were homogeneously diffused to the inside of the specimen.