• Journal of Trauma and Injury
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• v.18 no.1
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• pp.17-25
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• 2005

Background: Traumatic rupture of the aorta is a life-threatening injury that must be diagnosed as rapidly as possible and treated immediately. The chest X-ray is a valuable tool for screening traumatic rupture of the aorta in blunt chest trauma. And various chest radiologic parameters are being used as diagnostic tools for aortic injury. The purpose of this study is to identify chest radiographic parameters that may assist in the detection of traumatic rupture of the aorta and to compare these findings with those of other reports. Methods: This study involved 30 adult patients with traumatic rupture of the aorta seen at the emergency department of the Asan Medical Center from 1997 to 2004. The control subjects were 30 healthy patients with neither lung nor cardiovascular disease. We retrospectively assessed over 14 parameters on chest X-rays. Results: In 11 of the 14 parameters, there were significant differences between the study group and the control group. There was no significant difference in the M/C ratio (mediastinumto-chest width ratio) between the two groups, and neither the left nor the right paraspinal interface was statistically significant (p value>0.05). Our study indicates that new criteria for the MC ratio and for the paraspinal interfaces are needed for screening traumatic aorta injury. The other radiographic parameters for traumatic rupture of the aorta need to be further assessed through a prospective study.

• Clean Technology
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• v.12 no.4
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• pp.211-216
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• 2006

In this study, we investigated the potential changes in the cross sectional area of the rectangular microchannel with various zeta potentials and hydraulic diameters. We changed height/width ratio as 1, 1/2, and 1/3 and investigated its effect on the potential change. For this research, FEMLAB(Comsol, verson 3.0) was used to investigate the theoretical potential distribution. The potential changes in the cross section shows that right and left surfaces affect to some ranges. For the same area and shape, the potential value is directly proportional to the zeta potential change. With the decrease in the H/W ratio, the electrical double layer is condensed to the side surfaces.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.120-125
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• 2014

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.648-654
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• 1989

A clinical study was performed on 363 cases of pulmonary tuberculosis treated surgically resection during the period of 3 years from January, 1986 to December, 1988 in the National Kong-Ju Hospital. The results obtained are follows: 1. The ratio of male to female was 1.6:1 in male predominance, age from 20 to 40 occurred 82.6% of the total cases. 2. The moderately advanced cases was the highest incidence with 53.2 % for extent of disease, duration of illness which 1 to 5 years before operation was 40.8 % of the total cases. 3. Preoperative sputum examination for AFB was 53.2 % in negative but in spite of chemotherapy, persistent positive sputum was 46.7%. 4. Indication for surgery were: total destroyed lung was 35.5 %, destroyed lobe or segment with or without cavity was 30.6%, empyema with or without bronchopleural fistula was 8.5%, according to type and site of surgical procedure, pleuropneumonectomy and pneumonectomy was the highest incidence with 53.4 %, left site was slightly more than right with 55.9 % of the total cases. 5. The incidence of postoperative complication was 10.2 % and then the highest incidence was empyema with or without bronchopleural fistula with 4%, according to type of surgical procedure, postpleuropneumonectomy and postpneumonectomy was 6.1 % of the total cases. 6. Postoperative mortality was 1.4 % of the total cases, according to cause of deaths, hypovolemic shock due to bleeding were 2 cases, respiratory failure were 2 cases and hepatic coma due to hepatic failure was 1 case.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.552-556
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• 2016

Obstacle detection is a key feature in the safe driving control of electric wheelchairs. The suggested obstacle detection algorithm was designed to provide obstacle avoidance direction and detect the existence of cliffs. By means of this information, the wheelchair can determine where to steer and whether to stop or go. A 3D depth camera (Microsoft KINECT) is used to scan the 3D point data of the scene, extract information on obstacles, and produce a steering direction for obstacle avoidance. To be specific, ground detection is applied to extract the obstacle candidates from the scanned data and the candidates are projected onto a 2D map. The 2D map provides discretized information of the extracted obstacles to decide on the avoidance direction (left or right) of the wheelchair. As an additional function, cliff detection is developed. By defining the "cliffband," the ratio of the predefined band area and the detected area within the band area, the cliff detection algorithm can decide if a cliff is in front of the wheelchair. Vehicle tests were carried out by applying the algorithm to the electric wheelchair. Additionally, detailed functions of obstacle detection, such as providing avoidance direction and detecting the existence of cliffs, were demonstrated.

• Journal of Chest Surgery
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• v.15 no.4
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• pp.432-439
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• 1982

Congenital posterolateral diaphragmatic hernia [Bochdalek hernia] is the result of a congenital diaphragmatic defect in the posterior costal part of the diaphragm in the region of the tenth and eleventh ribs. There is usually free communication between the thoracic and abdominal cavities. The defect is most commonly found on the left [90%], but may occurs on the right, where the liver often prevents detection. The male to female ratio is 2:1. Owing to the negative intrathoracic pressure, herniation of abdominal contents through the defects occurs, with resultant collapse of the lung. Shifting of mediastinum to the opposite side and compression of the opposite lung occurs. Most often these hernias are manifestated by acute respiratory distress in the newborn. A second, but less well recognized, group of patient with Bochdalek hernia survive beyond the neonatal period, usually present at a later time with "failure of thrive, intermittent vomiting, or progressive respiratory difficulty. " The diagnosis can often be made on clinical ground from the presence of respiratory distress, absence of breath sounds on the chest presence of bowel sounds over the chest . Roentgenogram of the chest confirm the diagnosis. Obstruction and strangulation have been reported but are rare. Treatment consists of early reliable identification of these congenital diaphragmatic hernia with high risk and surgical repairment. and postoperative pharmacological management with extracorporeal membranous oxygenation [=ECMO] support in the period of intensive care. On the surgical approach, for defects on left side, an abdominal incision is preferred, because of the high incidence of malrotation and obstructing duodenal bands. In the neonate, the operative mortality may be appreciable, but, later repair almost always is successful. During the period from 1972 to 1982, 4 cases of congenital Bochdalek hernia were experienced at the Kyung-Hee University Hospital.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.3
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• pp.120-126
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• 2013

Objectives: This study sought to elucidate the effect of autogenous tooth bone material by experimenting on minipig's maxillary sinus and performing histological and histomorphometric analyses. Materials and Methods: Five 18-24 month-old male minipigs were selected, and right maxillary sinuses were grafted with bone graft material made of their respective autogenous teeth extracted eight weeks earlier. The left sides were grafted with synthetic hydroxyapatite as control groups. All minipigs were sacrificed at 12 weeks after bone graft, which was known to be 1 sigma (${\sigma}$) period for pigs. Specimens were evaluated histologically under a light microscope after haematoxylin-eosin staining followed by semi-quantitative study via histomorphometric analysis. The ratio of new bone to total area was evaluated using digital software for calculation of area. Results: All specimens were available, except one on the right side (experimental group), which was missing during specimen preparation. This study demonstrated new bone at the periphery of the existing bone in both groups, showing evidence of bone remodeling, however, encroachment of new bone on the central part of the graft at the 1 ${\sigma}$ period was observed only in the autogenous tooth bone group (experimental group). Histomorphometric analysis showed more new bone formation in the experimental group compared to the control group. Although the difference was not statistically significant (P>0.05), the mean percentage area for new bone for the experimental and control groups were $57.19%{\pm}11.16%$ and $34.07%{\pm}13.09%$, respectively. Conclusion: The novel bone graft material using autogenous tooth is a good alternative to autogenous bone, comparable to autogenous bone, and outperforming synthetic hydroxyapatite bone graft materials in terms of bone regeneration capacity. Augmentation with autogenous tooth bone materials will reduce donor site morbidity without hampering the safety of the autogenous bone graft.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.103-113
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• 1998

Until now, the study of eye refractive error examination for high school students are a few report that in Korea. In particular, there is few report about the visual power for same group during several years. We compared the study of refractive error done this year with that reported three years ago at the same high school. From the these data, the distribution of ammetropia was investigated. The study of refractive error for high school students was also compared with those reported before for the Adults and the middle school student. When the visual power is refered to spherical equivalent, the 36% of the whole students examined above had emmetropia and the other part of them fumed out to be ammetropia which is classify to 60.6% belonged to myopia and 4.4% belonged to hyperpia. The ratio of myopia for this year students is increased in comparision with the students in 1995. The ratio of emmetropia for this year students is 7.4% higher, and the ratio of myopia for this year students is 4% higher, but the ratio of hyperopia is very lower than that for the adults in 1997. In the kind of refractive error, it is classified that a simple myopia is shown to highest ratio as a 28.6% of 1212 eyes examined, a compound myopic astigmatism to the next high ratio as a 22.4%, a simple myopic astigmatism as 14.4%, a simple hyperopic astigmatism as 3.1%, a mixed astigmatism as a 1.7%, a simple astigmatism as 1.2%, a compound hyperopic astigmatism as 1.2%, respectively. The percentage of an astigmatism is a 76.7% of total eyes examined if Cyl-0.25 Dptr is included to an astigmatism. On the other hand, The percentage of an astigmatism is a 45.6% of total eyes examined if Cyl-0.25 Dptr is excluded to an astigmatism. In the kind of astigmatism, the number of students had an astigmatism with the rule is about 4.5 times than that of astigmatism against the rule. From the result of comparision the right eye with the left eye, the right eye of the students had more a myopic refractive error than the left eye, which is same as adults' case, there is no difference in a refractive error between the boy students and the girl students.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.511-516
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• 2002

Background: This study was undertaken in infant patients with isolated ventricular septal defect(VSD) to determine the effect of surgical closure on ventricular systolic time interval, as a parameter for ventricular performance, by echocardiography. Material and Method: Thirty patients were enrolled. Mean age of patients at operation was 6.5$\pm$3.2 months and all patients had non-restrictive VSD. We checked the left atrium/aorta(LA/Ao) ratio, left ventricle ejection fraction(EF), left ventricular systolic time interval(LVSTI), and right ventricular systolic time interval(RVSTI). Echocardiographic studies were done before surgical correction and postoperative periods(postopl: within 2 weeks, postop2: between 4 and 6 months, postop3: between 1 and 2 years). Result: LA/Ao ratio decreased significantly at immediate postoperative period compared to preoperative period and sustained during further follow-up period(from 1.74$\pm$0.37 to 1.36$\pm$0.24＊, 1.32$\pm$0.22＊, and 1.27$\pm$0.19＊, p<0.01). LV EF had not changed during follow-up periods(from 65.1$\pm$7.0 to 62.3$\pm$9.5, 62.8$\pm$5.7, and 64.1$\pm$6.9). LVSTI decreased significantly at postop2 and sustained during further follow-up period (from 0.46$\pm$0.13 to 0.46$\pm$0.11, 0.37$\pm$0.08＊, and 0.34$\pm$0.07＊, p<0.01). RVSTI decreased significantly at postop3(0.33$\pm$0.08 to 0.32$\pm$0.08, 0.31$\pm$0.07, and 0.27$\pm$0.05＊, p<0.01). Conclusion: We found that right and left ventricular systolic time intervals had decreased over the period of 1 year after surgical correction of VSD. Therefore, it is necessary to observe the change of ventricular function during that period.

• Journal of Korean Society of Rural Planning
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• v.6 no.2 s.12
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• pp.82-93
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• 2000

The concept of sustainable development in rural area, which is focused on both preservation of nature and human's amenity, has been common paradigm. The purpose of this study is to suggest the development directions for the environmentally friendly rural house. The planning items for developing sustainable rural house were selected through literature survey, case study, and their adaptation evaluation. The establishment of principles and the evaluation of planning items were analyzed by a survey to experts. The results are as follows : 1) It is showed that sustainability evaluation of rural village is rated as above the moderate degree, but rural house is rated as 3.4(average score). Especially, there were lowly evaluated the utility, material, structure and inner environment in rural house. 2) It is revealed that 76.7% of planning items are located in both the upper left and upper right hand quadrant of the action grid, which is drawn by the importance-performance analysis(IPA). And any item is not found in the lower right hand quadrant(Possible Overkill). 3) Two basic principles and eight optional principles we identified by analysis of factor and regression. The rural zone is identified as major effective element for applying planning items into the rural house development. So it is desirable to apply the items differently by the rural zone type. 4) In view of sustainable development, it is desirable for rural village to have about 50 houses, and for rural house to have $155{\sim}180$ pyung(坪) as lot size, 30% as ratio of building, and 60% as building volume.