• Journal of Chest Surgery
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• 제47권2호
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• pp.129-132
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• 2014

Various surgical techniques have been developed for the repair of an interrupted aortic arch. However, tension and Gothic arch formation at the anastomotic site have remained major problems for these techniques: Excessive tension causes arch stenosis and left main bronchus compression, and Gothic arch configuration is related to cardiovascular complications. To resolve these problems, we adopted a modified surgical technique of distal aortic arch augmentation using an autologous main pulmonary artery patch. The descending aorta was then anastomosed to the augmented aortic arch in an end-to-side manner. Here, we report two cases of interrupted aortic arch that were repaired using this technique.

• Journal of Advanced Marine Engineering and Technology
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• 제20권4호
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• pp.101-107
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• 1996

This test was performed on the hydraulic automatic gauge control(AGC) system of adaptive mass flow method. Fundamental purpose of this study are performance evaluation of this AGC system under the actual rolling condition. It was concluded that the response of AGC system depends on the dynamic characteristics of a reel motor or roll position. The test results are as follows : 1) The control method of reel motor current is better than than of the roll position as AGC system. 2) The more steel strip thickness of delivery side is thick, the larger the gauge deviation is large, and the more it is thin, the larger the gauge deviation rate is large. 3) Because the gauge deviation is large at acceleration and deceleration speed than steady speed, so AGC system is better to adopt over 50m/min. By applying this AGC system, not only the accurary in strip thickness were improved but also productivity was improved dramatically.

• 대한토목학회논문집
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• 제32권5A호
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• pp.255-266
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• 2012

현수교 주케이블은 완성시 교량의 구조적 건전성을 나타내는 중요한 지표이다. 주케이블은 가설완료시 자유 매달림(free hanging) 상태의 형상이 되며 교량완성시 행어, 보강형 등의 고정하중을 지지하여 가설완료시 형상과는 차이가 발생한다. 따라서, 주케이블의 가설완료시 형상이 교량완성시 형상에 직접적인 영향을 미치므로 가설중 형상관리가 매우 중요하다. 주케이블의 가설중 형상관리는 중앙 및 측경간은 새그조정으로, 정착경간은 장력조정으로 수행된다. 새그조정은 새그조절량에 대한 스트랜드 길이 조절량을 나타내는 산정값인 새그민감도가 필요하며 장력조정은 온도변화에 대한 장력변화량을 나타내는 장력민감도가 필요하다. 이에 본 연구에서는 케이블 형상가정에 따라 유도된 기본식과 이로부터 도출된 미분 관계식으로부터 새그 및 장력민감도를 산정하는 방법을 제안하였다. 그리고, 다양한 새그변화 요인에 대해 현수선 기본식을 사용한 비선형 수치해석 새그민감도 계산 흐름도를 제안하여 미분관계식을 적용한 새그민감도 결과와 비교하였다. 또한, 각 새그변화 요인이 복합적으로 발생함으로 이를 고려하여 케이블의 최종 새그변화량을 산정하는 방법을 제안하였다. PPWS 공법으로 시공중인 실교량을 대상으로 PPWS의 길이변화 및 온도변화, 경간장변화 등의 다양한 시공여건의 변화에 따른 새그 및 장력민감도를 산정하였다. 본 연구내용이 주케이블 가설중 형상관리 방법에 대한 체계적인 지침이 되기를 바라며, 향후 실교 현장적용 및 실증에 의해 완성도를 높일 것이다.

• 대한치과교정학회지
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• 제20권2호
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• pp.319-331
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• 1990

The purpose of this study was to help examining force system, optimal treatment, and prevention of relapse. Orthodontic force was generated by electromagnets, therefore duration could be freely controlled, and applied for 4 days in dogs. Force magnitude was 200gm and 50gm. duration was contious and intermittent. Intermittent duration was divided into 2 kinds of types in on/off, 1 mininute/1 minute, 10 seconds/1 minute. The results were as follows: 1. In the intermittent group to which force was applied for 10 seconds and ceased for 1 minute, osteoclast was not observed. 2. In the intermittent group to which 200gm of force was applied for 1 minute and ceased for 1 minute, there was blood circulation in periodontal space on pressure side, but mild hyalinized zone was observed. 3. More number of total osteoclast was counted in the pressure side of continous group to which 200gm of force was applied than in any other groups. 4. More number of frontal osteoclast was counted in the pressure side of intermittent group to which 200gm was applied for 1 minute and ceased for 1 minute than in any other groups. 5. On tension side, less periodontal space widening, more new bone and secondary cementum formation were observed in the intermittent group to which force was applied for 1 minute and ceased for 1 minute than in the continous group.

• 한국기계가공학회지
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• 제11권6호
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• pp.82-87
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• 2012

The purpose of this study is to produce a side impact beam with high tensile steel using a roll forming process. The door side impact beam plays an important roll in a car because it protects passengers from external crash. The roll forming process is a continuous bending process wherein a long metal sheet is bended as it continuously passes several rolls. The characteristic of this study is that an impact beam is produced by a continuous process using a ultra high strength steel without a hardening heat treatment. A model was determined by analysing plasticity of a cross section shape considering high strength. Design parameters of the impact beam was determined by crash-analysing the model. Workpiece products were manufactured by designing dies for roll forming and setting them up in a following process line. Results of a bending test and a FEM analysis was considered and reviewed.

• 대한치과교정학회지
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• 제14권1호
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• pp.65-81
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• 1984

In order to observe the responses of the periodontal tissue on the tension side following the experimental tooth movement, 35 Guinea pigs were divided into the control group (5 animals) and 6 experimental groups (3 movement groups and 3 retention groups) consisting of each 5 animals. The experimental tooth movement of Guinea pig's upper incisors installing open helical loop were carried out by rendering continuous force : 5g (1st groups) 35g (2nd groups), 100g (3rd groups), respectively for 7 days. 3 movement groups (15 animals) were sacrificed soon after the continuous force, and 3 retention groups (15 animals) were sacrificed after the retention period of another 7 days. The following results were obtained from the observation of the surrounding tissues of teeth on the tension side through light microscopy any transmission electron microscopy. 1. The vessel walls in the experimental groups were thinner than those of the control group, the number of blood vessel had the tendency to increase. The greater the strong force applied to each group, the more the destruction of cells and fibers was found and the more the number of the red blood cell of vessel outside appeared. 2. New collagen fibers were produced from fibroblasts in the 1st groups (light force), but were produced rather less in the 2nd groups (medium force) and the 3rd groups (heavy force). 3. In the forming patterns of the new alveolar bone of the 3rd groups (heavy force), the bone trabeculae were formed towards the direction of the force to be applied, but the new alveolar bone in the 1st groups (light force) was produced evenly throughout the all surfaces of the alveolar bone rather than the patterns of bone trabeculae ; therefore, the patterns of new alveolar bone were observed differently according to the magnitude of the force applied. 4. In the retention group, it was observed that the collagen fibers were produced from the osteoblasts in the marginal areas of the periodontal ligaments being widely opened and were deposited on the alveolar bone surface but the production of collagen fibers from the osteoblasts in the other area of the periodontal ligaments was almost ceased, and a rest line on the new alveolar bone surface was found.

• Journal of Chest Surgery
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• 제10권2호
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• pp.205-213
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• 1977

In order to evaluate the therapeutic effect of thoracostomy on the patients with pathological changes in pleural cavity which were caused by various etiological factors, a clinical study was carried out during a period of 5 and half years from May 1972 to September 1977 in the department of thoracic surgery, Hanyang University Hospital, and the following results were obtained. Of a total of 264 patients, 205 cases were male, and 59 female, exhibiting the ratio of male to female being 3.5 to 1. The pathological changes in pleural cavity could occur at any age from 4 months after birth to 76 years old, the peak incidence being in the third decade in either male or female. The incidence decreased in the second, fifth and fourth decade in order. The type of pathological changes observed and their frequencies of occurrences were 93 cases [35.2%] in pneumothorax, 62 cases [23.5%] in hemothorax, 48 cases [18.2%] in pyothorax, 46 cases [17. 4%] in hemopneumothorax, 13 cases [4.9%] in hydropneumothorax, and one case each in hydrothorax and chylothorax. The incidence of the primary diseases which predisposed the pathological changes in pleural cavity were, 119 cases [45-1%] in trauma, 64 cases [24.2%]in lung tuberculosis, 38 cases [14.4%] in pneumonia or empyema, 14 cases [5.3%] in lung emphysema and blebs, 13 cases [4.9%] in process after thoracotomy, 3 cases [1.1%] each in lung malignant tumor and lung paragonimiasis, one case in mechanical ventilator and 9 cases [3.4%] in unknown origin. The pathological changes in pleural cavity were located in the right side of the cavity in 124 cases, in the left side in 133 cases and in both sides in 7 cases, indicating that the difference between the incidence of the left and rightside occurences was insignificant. Of 93 cases of pneumothorax studied, 63 cases were found to have been tension pneumothorax and 30 cases non-tension pneumothorax, showing greater prevalence of tension type over non-tension type. Of 119 cases of trauma observed, 82 cases were accompanied with rib fractures and 37 cases were without any fracture [non-bone fracture]. Patients with the rib fractures were characterized by multiple rib fractures and multiple double fractures of ribs, accompanying with or without fracture of bones other than ribs, and patients with non-bone fracture were characterized by penetrating stab wound and blunt trauma. Of 264 cases who received thoracostomy, 207 cases [78.4%] demonstrated that their pathological changes in pleural cavity were removed and subsided by a simple measure of thoracostomy. In 43 cases [16.3%], various surgical measures including radical operation and thoracotomy were required for complete healing, since their pathological changes were not abolished by thoracostomy alone. The rest 14 cases [5.3%] were expired following thoracostomy.

• Geomechanics and Engineering
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• 제22권6호
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• pp.541-552
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• 2020

With the increasing tension of current coal resources and the increasing depth of coal mining, the gob-side entry retaining technology has become a preferred coal mining method in underground coal mines. Among them, the technology of the gob-side entry retaining with the high-water filling material can not only improve the recovery rate of coal resources, but also reduce the amount of roadway excavation. In this paper, based on the characteristics of the high-water filling material, the technological process of gob-side entry retaining with the high-water filling material is introduced. The early and late stress states of the filling body formed by the high-water filling materials are analyzed and studied. Taking the 8th floor No.3 working face of Xin'an coal mine as engineering background, the stress and displacement of surrounding rock of roadway with different filling body width are analyzed through the FLAC^3D numerical simulation software. As the filling body width increases, the supporting ability of the filling body increases and the deformation of the surrounding rock decreases. According to the theoretical calculation and numerical simulation of the filling body width, the filling body width is finally determined to be 3.5m. Through the field observation, the deformation of the surrounding rock of the roadway is within the reasonable range. It is concluded that the gob-side entry retaining with the high-water filling material can control the deformation of the surrounding rock, which provides a reference for gob-side entry retaining technology with similar geological conditions.

• 대한치과교정학회지
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• 제27권5호
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• pp.825-837
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• 1997

실험적 치아이동 후 보정기간 동안 고정방법이 치주인대 섬유의 재배열에 미치는 영향을 알아보기 위하여, 체중 20kg 내외의 성견에서 상악 제 3절치와 견치 사이에 견인 스프링을 이용하여 120 gm의 교정력을 3주간 가한 후 좌측에는 유연성 고정장치로 0.0215 인치 multistrand wire를, 우측에는 견고성 고정장치로 폴리 에틸렌 리본을 레진 접착제로 각각 장착한 다음 4주, 8주, 또는 12주 후 희생시켜 치주조직의 변화를 방사선 사진, 광학 현미경 관찰을 통하여 분석한 바 다음과 같은 결과를 얻었다. 1. 치아이동 후 압박측에서는 치주인대 공간의 압축과 함께 치주인대섬유가 굵어진 소견을 보였으며 인장측의 치주인대섬유는 신장되어 보였다. 2. 보정 4주 후 유연성 고정군에서는 치주인대섬유의 재배열이 관찰되었으나 견고성 고정군에서는 관찰되지 않았다. 3. 보정 8주 후부터는 두 군 모두에서 치주인대섬유의 재배열 소견이 관찰되었으며, 두 군간 치주인대섬유의 재배열 차이는 보이지 않았다. 4. 보정기간 동안 치주인대섬유의 재배열은 압박측 보다 인장측에서 빠른 소견을 보였다. 이상의 결과는 치아이동 후 견고하게 고정한 보정방법에서도 치주인대섬유의 재배열이 일어남을 보여주었고, 치아 보정시 폴리에틸렌 리본으로 고정한 보정장치도 유용하게 사용될 수 있음을 시사하였다.

• 대한치과교정학회지
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• 제30권4호
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• pp.423-431
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• 2000

교정적 치아이동 중 골개조는 수종의 매개물질에 의하여 조절된다. 특히 IL-$1\beta$는 실험동물의 교정적 치아이동 중 압박측과 긴장측 모두의 치근막과 치조골에서 골흡수를 촉진하고 골형성을 억제하는 효과를 보이는 것으로 알려져 왔다. 이 연구는 인체에서의 교정적 치아이동 중 압박측과 긴장측 치은열구액에서 IL-$1\beta$의 발현을 찾고 발현양의 시간적 변화를 관찰하였다. 전신질환인 없고 임상적으로 건강한 치주조직을 가진 평균 19.2$\pm$4.2세, 12명의 남녀환자에서 편측 견치를 원심으로 견인하였다. 실험군(원심 견인측)의 근심과 원심, 대조군(동일환자의 반대편 견치)의 근심 치은열구액을 견치 후방 이동 직전, 1시간 후, 24시간 후, 168시간 후의 4개의 시간대 별로 수집하여 총단백질 농도(BCA법)와 IL-$1\beta$(ELISA법) 의 농도를 비교, 관찰하여 다음과 같은 결과를 얻었다. 1. 실험군에서의 IL-$1\beta$ 농도는 교정력을 가한 후 증가하여 24시간 전후에 최대값에 도달하였다. 2. 대조군에서의 IL-$1\beta$ 농도는 시간에 따라 유의한 차이를 보이지 않았다. 3. 교정력을 가한 24시간 후에서 IL-$1\beta$의 농도는 압박측에서 가장 높고, 이어 긴장측과 대조군의 순이었다.