• 대한기계학회논문집
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• 제10권5호
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• pp.758-769
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• 1986

본 연구에서는 직교이방성 복합재료 원통셀의 진동 방정식을 Sanders, Love 및 Donnell의 셸이론에 기초하여 유도하고 이를 통일된 형태로 표현하였으며 등방성 원통셸에 대한 Chung의 해석법을 채용하여 임의의 경계조건을 갖는 직교이벙성 복합 재료 원통셸에 대해서 간편히 이용할 수 있는 유용한 해석방법을 제시하였다.

• 생명과학회지
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• 제10권4호
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• pp.368-373
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• 2000

Enteroviruses in the environment pose a public health risk because they can be transmitted via the fecal-oral route through contaminated water, and low numbers are able to initiate an infection in humans. Because the levels of viruses typically found in environmental water and drinking water are low, they must be concentrated from hundreds to thousands of liters of water. Therefore, the main goal of this study was the development of a rapid, simple and efficient procedure to concentrate, isolate and detect enteroviruses from environmental water samples. Viruses were first concentrated by adsorption to 1 MDS cartridge filter and then eluted with approximately 0.5 liter of 1.5% beef extract/0.05M glycin(pH 9.4). In this study, several procedures to concentrate and purify intact viruses from beef extract obtained from the adsorbent filters were tested. Among them, organic floccuration was the best reliable method for reconcentration. sample volume could be reduced to 200∼400 folds and the efficiency of virus recovery through the procedure was over 72%. Finally, the samples were filtered through a membrane disk filter and then analyzed by either the plaque assay or combined cell culture-polymerase chain reaction.

• Journal of Chest Surgery
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• 제25권1호
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• pp.23-31
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• 1992

The ideal approach in the staged management of patients with pulmonary atresia has been a challenging problem and the result has not been always satisfactory. We reviewed our early result of initial palliative surgeries in fifteen cases of pulmonary atresia with interventricular communication Included are eight cases of simple pulmonary atresia with ventricular septal defect and seven cases of pulmonary atresia associated with other complex cardiac anomalies. The ages of the patients were less than one year except one. The morphology of pulmonary vasculature was highly variable and showed unfavorable conditions in most cases. Pulmonary artery was nonconfluent in two. Two-thirds of all cases showed significant problems such as juxtaductal stenosis or diffuse hypoplasia. The ductus arteriosus usually narrowed at its pulmonic end. Initial palliation was done by modified Blalock-Taussig shunt in six, central shunt with or without pulmonary angioplasty in five, right ventricular outflow tract [RVOT] reconstruction in three and direct connection of nonconfluent pulmonary arteries with bilateral cav-opulmonary shunt in one patient. There were 3 hospital deaths. Two of them underwent simultaneous repair of the associated anomaly of TAPVR. Among the six patients who received modified Blalock-Taussig shunt, three needed early second palliative procedure by central shunt, RVOT patch reconstruction and pulmonary angioplasty in each case, All patients who received central shunt showed marked clinical improvement. Among the twelve patients who survived the palliative procedures, two patients underwent total correction 13 months and 18 months after initial palliation respectively. We think that the choice of palliative procedure must be individualized according to the morphology of the pulmonary arteries. More experience and long term follow-up data are necessary to meet this challenging problem.

• 미생물학회지
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• 제40권4호
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• pp.359-363
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• 2004

자연계에 존재하는 미생물의 대부분이 배양이 불가능하다는 것이 밝혀진 이후, 자연계의 시료로부터 직접 유전자를 클로닝하여 유용유전자를 발굴하는 메타제놈(metagenome) 이용 방법이 주목을 받게 되었다. 그러나 실제로 오염이 심한 환경시료로부터 DNA를 추출하여 유용한 메타제놈 라이브러리(metagenomic library)를 제작하기란 쉽지 않은 일이다. 따라서 본 연구에서는 실제 메타제놈 라이브러리를 제작할 때 만나는 기술적 문제점에 대한 해결 방법을 탐구하였다. 메타제놈 라이브러리 제작에는 fosmid vector가 가장 편리하였으며, 성공적인 라이브러리제작에는 fosmid vector에 클로닝이 가능한 40 kbp 크기의 DNA 조각을 얻는 과정이 중요함을 알았다. 여러 실험 조건을 종합적으로 검사한 후 메타제놈 라이브러리 제작에 대한 최적 방법을 제사하였다.

• 미생물학회지
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• 제12권3호
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• pp.131-137
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• 1974

It is a well-known fact that an isolation of non-sporeforming anaerobes, considered normal flora in man ordinarily but causes serious infections sometimes, is a dificult procedure because of their great oxygen sensitivity. Among the many techniques employed in clinical laboratories, despite of its high expenses, the GasPak method has been most widely used because of its relative simplicity. On the other hand, the steel wool method has gained a good reputation recently. This technique makes it possible to treat individual plate so that any single specimen can be promptly cultured anaerobically. The procedure is quite simple and the expenses are negligible. In the present study it is to compare these two methods as to their efficiency of anaerobic cultivation using 13 VPI strains of non-sporeforming amaerobic bacteria. Among the 13 species the following 11, Bacteroides fragilis ss. fragilis, B. fragilis ss. thetaiotaomicron, propionibacterium acnes, Eubacterium limosum, E. lentum, peptococcus asaccharolyticus, Pc. prevotii, Pc. magnus, peptostreptococcus anaerobius, Ps. intermedius nad Veillonella parvula, grew well with the steel wool method whose colony numbers reaching 57 to 119% of those with GasPak method. The remaining two species, Fusobacterium nucleatum and F.necrophorum, did not grow well with the steel wool method showing the colony numbers were only 0.4% of those with GasPak method in the case of Fusobacterium nucleatum. In the case of Fusobacterium necrophorum, very few colonies developed even with a heavy inoculation. As to the size of colonies, there were no significant difference between these two methods.

• 자원ㆍ환경경제연구
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• 제15권3호
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• pp.451-477
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• 2006

기술확산 단계에서 이루어지는 기술대안에 대한 평가는 단순한 과정이 아니고, 기술적 특성뿐만 아니라 경제적 효과 등 여러 가지 요소들이 고려되어야 하는 복합적인 평가과정을 가지게 된다. 이는 오늘날 산업계 각 분야에서 바람직한 기술대안의 평가, 선정 및 적용이 기업경쟁우위에 지대한 영향을 미치며 나아가 기업의 생존 및 성장을 좌우하기 때문이다. 본 연구에서는 열공급시스템의 기술적 대안 선정을 위한 방법론으로서 MAUT 방법을 고찰하고, 이 방법의 실무적 적용 가능성을 검토하기 위해 에너지기술분야의 폐열 활용시스템 대안들에 대한 평가에 적용한 결과를 제시하였다.

• 로봇학회논문지
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• 제12권4호
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• pp.411-418
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• 2017

During the intramedullary nailing procedure, surgeons feel difficulty in manipulation of the X-ray device to align it to axes of nailing holes and suffer from the large radiation exposure from the X-ray device. These problems are caused by the fact the surgeon cannot see the hole's location directly and should use the X-ray device to find the hole's location and direction. In this paper, we proposed the robotic guidance of the distal screwing using an optical tracking system. To track the location of the hole for the distal screwing, the reference marker is attached to the proximal end of an intramedullary nail. To guide the drill's direction robustly, the 6-degree-of-freedom robotic arm is used. The robotic arm is controlled so as to align the drill guiding tool attached the robotic arm with the obtained the hole's location. For the safety, the robot's linear and angular velocities are restricted to the predefined values. The experimental results using the artificial bones showed that the position error and the orientation error were 0.91 mm and $1.64^{\circ}$, respectively. The proposed method is simple and easy to implement, thus it is expected to be adopted easily while reducing the radiation exposure significantly.

• 한국자동차공학회논문집
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• 제6권4호
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• pp.76-85
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• 1998

Recently, Genetic Algorithm(GA) is widely adopted into a search procedure for structural optimization, which is a stochastic direct search strategy that mimics the process of genetic evolution. This methods consist of three genetics operations maned selection, crossover and mutation. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GA, being zero-order method, is very simple. So, they can be easily applicable to wide area of design optimization problems. Also, owing to multi-point search procedure, they have higher probability of converge to global optimum compared to traditional techniques which take one-point search method. In this study, a method of finding the optimum values of suspension parameters is proposed by using the GA. And vehicle is modelled as planar vehicle having 5 degree-of-freedom. The generalized coordinates are vertical motion of passenger seat, sprung mass and front and rear unsprung mass and rotate(pitch) motion of sprung mass. For rapid converge and precluding local optimum, share function which distribute chromosomes over design bound is introduced. Elitist survival model, remainder stochastic sampling without replacement method, multi-point crossover method are adopted. In the sight of the improvement of ride comfort, good result can be obtained in 5-D.O.F. vehicle model by using GA.

• 대한후두음성언어의학회지
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• 제25권2호
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• pp.96-98
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• 2014

Injection laryngoplasty is simple and useful procedure in patient with vocal cord paralysis even under local anesthesia. For approaching vocal cord level, flexibility of neck mobility is required to operate injection laryngoplasty but it is relatively difficult to approach vocal cord in patient who has cervical fixations. Laryngeal mask airway (LMA) can be helpful:We use a LMA (I-gel$^{TM}$) during intubation without neck extension on flat supine position under general anesthesia and have a good operation filed. LMA with swivel connector give surgeons better surgical vision and make insertion of fibroscope easily during operation. Hyaluronic acid injection was done use needle (25 G, 5 cm) via percutaneous cricothyroid space : This procedure can be useful method for patients who suffer from not only weak voice but also dysphagia and aspiration high vagal palsy patient after spine surgery or uncooperative with awake injection laryngoplasty.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.800-812
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• 2014

The paper provides some results of a new procedure to analyze the hydrodynamic aspects of the interactions between maritime emerged breakwaters and waves by integrating CAD and CFD. The structure is modeled in the numerical domain by overlapping individual three-dimensional elements (Tetrapods), very much like the real world or physical laboratory testing. Flow of the fluid within the interstices among concrete blocks is evaluated by integrating the RANS equations. The aim is to investigate the reliability of this approach as a design tool. Therefore, for the results' validation, the numerical run-up and reflection effects on virtual breakwater were compared with some empirical formulae and some similar laboratory tests. Here are presented the results of a first simple validation procedure. The validation shows that, at present, this innovative approach can be used in the breakwater design phase for comparison between several design solutions with a significant minor cost.