• Journal of Chest Surgery
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• v.38 no.9 s.254
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• pp.609-615
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• 2005

Background: Some controversy still exists concerning the operative indications of coronary fistulas. Nevertheless, a short-term and long-term outcomes are excellent with surgical interventions. In this study, we assessed our surgical results on this disease entity during the last 20 years. Anatomic diversity was described as well. Material and Method: From April 1986 to March 2005, 20 patients with coronary fistulas underwent surgical correction in Seoul National University Children's Hospital. Their medical records were reviewed retrospectively. Result: Twelve patients ($60\%$) were asymptomatic prior to surgery. All had electrocardiogram and echocardiogram and all but 3 had coro-nary angiogram preoperatively. Anatomically, none of them had two or more coronary fistulas. The sites of origin were left coronary system in 11 patients and right in 9. The draining sites were right ventricle in 11, right atrium in 3, left ventricle in 3, main pulmonary artery in 2, and superior vena cavae in 1. All of the involved, the coro-nary arteries were dilated or aneurismal. In 1 case, there was atherosclerotic change but no ischemic evidence in preoperative electrocardiogram. Operative techniques included external obliteration (13), internal obliteration (5), and both (2). External obliteration was done by ligation of the fistulous tract only in T patients, by fstula ligation plus plication in 3 and by plication or patch closure via fistulotomy in 3. There was no operative mortality. All of postoperative morbidities including transient sinus arrhythmia (2), complete atrioventricular block (1), decreased left ventricular function (2), ventricular tachycardia (1), pericarditis (1), and seizure (1) improved on discharge. The mean follow-up was 55.1$\pm$50.2 months (4.0 months${\~}$18.0 years) and there were no recurrences of fistula. There was 1 second operation for aortic root aneurysm, which developed after external patch closure of right coronary fistula. Conclusion: We demonstrated here that coronary fistulas can be cured with excellent clinical outcome and low operative risk under precise diagnosis. Understanding the anatomic diversity will help to construct surgical plans.

• International Journal of Ocean System Engineering
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• v.2 no.3
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• pp.185-194
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• 2012

A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.

• Journal of the Korean Society of Costume
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• v.26
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• pp.175-206
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• 1995

The costume culture of China is as old and varied as her long history. As China is a multiracial nation and consists of fifty-six min-ority races including Han race, there are not only fifty-six different costumes in China but each races' costume habit is very different. Therefore, Chinese penninsula can be considered an enor-mous exhibition center of the costumes. This study undertook on the assumption that the costumes' mainstream of Korea and east-northern Asia as well as that of China could be examined by investigating the minority races' costumes in the east-and west-northern areas of China. The process of evolution of the costume of a particular people, country or area is subject not only to constraints related to geography such as climate, topography or local products but is also affected by numorous environmental influences including cultural, economic, social and even pol-itical ones in terms of the selection of material, styling, color and standard of tailoring. In other words, things like philosophy of life, religious be-lief, aesthetic outlook, moral code, class system, degree of affluence, and cultural exchange will all be reflected directly or indirectly by features of a people's or country's style costume. Of course, there are several factors affecting to the style of costume of the minority people in China. However, the only three factors-geo-graphical and environmental, production method, and religious belef-will be touched in this study. First of all, the geograghical and eenviron-mental factor would be the decisive one because the costume should be designed to overcome the constraints of climate and geographical environ-ments. Accordingly, each race has an unique style of costume. The costume of the minority races in the northern parts are loose and wide, and made of warm furs. For instance, Mongolian robe has the quality of anti-wind, anti-cold and warmness, and the width of a sleeve is narrow and long. Secondly, the costume style can be said to be limited by the production pattern, when the geo-graphical environment was affected to decide the costume style, the production pattern was together affected to it . In case of Mongolian robe, they should satisfy the dual condition as the practical function. One is the condition that they should be fitted to the climate, and the other is the condition that they should be suit-able to the nomadic life. Mongolian robes are suitable to the nomadic peoples because they are designed for not only overcoming the cold wind and weather but being used as the bedquit at night. The costumes of Hoche people was made of the skin of the fish and wild animals because of their main means of living being fishing and hunting. Accordingly, their costumes are dur-able, warm and water-proof. Finally, the style of the costume is affected by the religious belief. In other words, the pattern in fashion is closely related with the religious be-lief or ancestor worship and nature worship. Ac-cordingly, the symbols of these worship are often emerged in the decoration of the costume. The design of costume of the people in the northern areas of China is very simple. It is related with their monotheism. On the other hand, the costumes of twen쇼 minority races in the east-northern parts of China can be devided into three racial groups such as the long robes of Man people and Mongols, Tunics of the peoples in the west-northern areas, and the pants and jackets of Hoche people. The minorority races all has not only the unique costume habit but their costumes are also related with their living style and production means.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.23-28
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• 2005

Ross procedure is ideal aortic valve replacement method with several merits of hemodynamic superiority and durability without the need of anticoagulation. Based upon this presumption, we studied its procedure performed in our hospital and tried to get the mid-term results Material and Method: From Jan 1999 to Oct 2001, 22 patients underwent the Ross procedure. The mean age of experimented (including 17 men and 5 women) was $30.9{\pm}8.1(17\~44)$. The diagnosis before the surgery had shown 20 as accompanied with AR and the rest 2 as with ASR. The follow-up period ranged from 0.6 to 40.6 months, mean of $38.9{\pm}1.6\;months,\;and\;follow-up\;rate\;was\;100{\%}$. Result. There was no operative death and two late deaths, one of whom was cardiac originated and the other, non-cardiac relate The survival rate was $94.1{\pm}5.7{\%}$(40.6 months). Postoperatively there were 2 exploration for bleeding, 3 low cardiac output patients. The pulmonary autograft technique was root replacement in 14 and inclusion technique in 8. Pulmonary homografts were used at the pulmonary position in all cases. There was no patient with significant aortic regurgitation. Conclusion: These showed that the mortality and morbidity of the Ross procedure were acceptable and postoperative AR was not significant. However, further long-term follow-up will be necessary for the improvement of the function of pulmonary autograft and homograft.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.739-744
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• 1999

Background: This study was designed to evaluate the effectiveness of T3 sympathicotomy in treatment of palmar hyperhidrosis. Material and Method: During the period of June to December 1998, 50 patients (24 females and 26 males) suffering from palmar hyperhidrosis either in isolation (n=37) or in combination with axillary hyperhidrosis (n=13) were operated. The mean age of the patients was 20 years. The bilateral sympathetic trunks were severed on the 3rd rib (2nd and 3rd ganglia) for the isolated palmar hyperhidrosis and on the 3rd and 4th ribs for the combined type using electrocoagulation scissors. A linear analogue scale was used to assess the degree of sweating on the palms, face, trunk, and feet (ranged 0 to 10:0 = anhidrosis: 10 = excessive sweating) as well as the patient's satisfaction with the surgery (ranged 0 to 10:0 = regret; 10 = completely satisfied). Result: All of the patients were relieved from palmar hyperhidrosis. A mean palmar sweat production score after T3 sympathicotomy was $1.5\pm$0.8. Some degree of compensatory sweating had occurred in 39 patients (78%) with a mean score of 3.4$\pm$1.6. Gustatory sweating occurred in 2 patients (4%). The mean score of the patient's satisfaction after the surgery was 8.5$\pm$1.2. Conclusion: Palmar hyperhidrosis can be successfully relieved by the T3 sympathicotomy. When considering the advantages of T3 sympathicotomy with respects to a better preservation of facial sympathetic function, less occurrence of severe compensatory sweating, and lower incidence of gustatory sweating. We recommend T3 sympathicotomy as a treatment of choice for palmar hyperhidrosis.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.482-491
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• 2004

Background: The xenogenic or allogenic valves after in Vitro repopulation with autologous cells or in vivo repo-pulation after acellularization treatment to remove the antigenicity could used as an alternative to synthetic polymer scaffold. In the present study, we evaluated the process of repopulation by recipient cell to the acellu-larized xenograft treated with NaCl-SDS solution and grafted in the right ventricular outflow tract. Material and Method: Porcine pulmonary valved conduit were treated with. NaCl-SDS solution to make the grafts acellularized and implanted in the right ventricular outflow tract of the goats under cardiopulmonary bypass. After evaluating the functions of pulmonary valves by echocardiography, goats were sacrificed at 1 week, 1 month, 3 months, 6 months, and 12 months after implantation, respectively. After retrieving the implanted valved conduits, histopathologic examination with Hematoxylin-Eosin, Masson' trichrome staining and immunohistochemical staining was performed. Result: Among the six goats, which had been implanted with acellularized pulmonary valved conduits, five survived the expected time period. Echocardiographic examinations for pulmonary valves revealed good function except mild regurgitation and stenosis. Microscopic analysis of the leaflets showed progressive cellular in-growth, composed of fibroblasts, myofibroblasts, and endothelial cells, into the acellularized leaflets over time. Severe inflammatory respon-se was detected in early phase, though it gradually decreased afterwards. The extracellular matrices were regenerated by repopulated cells on the recellularized portion of the acellularized leaflet. Conclusion: The acellularized xenogenic pulmonary valved conuits were repopulated with fibroblasts, myofibroblasts, and endothelial cells of the recipient and extracellullar matrices were regenerated by repopulted cells 12 months after the implantation. The functional integrity of pulmonary valves was well preserved. This study showed that the acellularized porcine xenogenic valved conduits could be used as an ideal valve prosthesis with long term durability.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.175-183
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• 2009

Background: Mitral valve abnormalities in the pediatric population are rare. Mitral valve replacement or pediatric mitral lesions can cause problems such as a lack of growth potential. There re only limited experiences with mitral valve repair at any institution, so the purpose of his study is to evaluate the outcomes of mitral valve repair n pediatric patients. Material and Method: Sixty-four consecutive children (28 males and 36 females) with a mean age of $5.5{\pm}4.7$ years underwent mitral valve repair for treating their congenital mitral valve disease between January 1996 and December 2005. The patients were divided into two groups: group 1 (34 patients (53.1%)) had isolated disease (mitral anomaly with or without trial septal defect or patent ductus arteriosus) and group 2 (30 patients (46.9%)) had complex disease (mitral anomaly with concurrent intracardiac disease, except atrioventricular septal defect). Result: The overall in-hospital mortality was 6.3%; group 1 had 5.9% mortality and group 2 had 10.0% mortality. The postoperative morbidity was 18.8%; group 1 and 2 had 14.7% and 23.3% postoperative morbidity, respectively, and there as no significant difference among the groups. The median follow-up was 4.6 years range: $0.5{\sim}12.2$ years). The 10-year survival rate was 95.3%. The 10-year freedom from re-operation rate was 76.1% with 10 re-operations. The majority of the functional classifications were annular dilatation and leaflet prolapse. A mean of $2.1{\pm}1.1$ procedures per patient were performed. The echocardiography that was done at the immediate postoperative period showed a significant improvement in the mitral valve function. The follow-up echocardiographic results were significantly improved. However, mitral stenosis newly developed over time, and there ere significant differences according to the repair strategies. Conclusion: The patients who underwent mitral valve repair for congenital mitral anomalies showed good results. The follow-up echocardiography revealed satisfactory short-term and long-term results. Close follow-up is necessary to detect the development of postoperative mitral stenosis or regurgitation.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.214-219
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• 2009

Background: Primary focal hyperhidrosis is characterized by overactivity of the sympathetic nervous function, and this has been effectively treated with endoscopic thoracic sympathetic denervation (ESD). The imbalance of sympathetic and parasympathetic nervous system that's created by ESD may affect the heart, lung and other thoracic organs. We analyzed the heart rate and ECG changes after performing ESD at our hospital, and this is the first such study that has been conducted on this. Material and Method: Of the 263 patients who underwent ESD between October 1996 and October 2006, 130 had ECG before and after ESD, and they were classified into 3 groups according to the level of ESD: Group I (n=40) patients underwent ESD at the 2nd rib (T2ESD), Group II (n=80) at the 3rd rib (T3ESD) and Group III (n=10) at the 4th rib (T4ESD). Result: There was no mortality or major morbidity. Heart rate (HR) was significantly decreased from $71.6{\pm}10.6/min\;to\;66.8{\pm}10.2/min$ after ESD (p<0.01); however, the PR (from $148.6{\pm}21.2$ msec to $152.8{\pm}20.5$ msec) and QTc (from $399.2{\pm}15.4$ msec to $404.0{\pm}15.1$ msec) intervals were significantly increased after ESD in the patients who suffered with primary hyperhidrosis (p<0.01). According to the level of ESD, there were significant changes in the HR and QTc interval in group I (T2ESD), the HR and PR interval in group II and the QTc interval in Group III. Conclusion: There were significant changes in the heart rate and ECG findings after ESD. The thoracic sympathetic denervation of T2, T3 and T4 affected the electrical activity of the heart at the resting state.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.9-13
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• 2009

Background: Hypoplastic left heart syndrome is uniformly fatal if this condition is not properly treated. We reviewed the surgical results of treating hypoplastic left heart syndrome, and we evaluated the hemodynamics and functional status of these patients after they underwent a Fontan operation. Material and Method: To assess the surgical results, we retrospectively reviewed the medical records of 6 (M/F=4/2) patients who underwent a staged operation, including a Norwood procedure, a bidirectional Glenn procedure and a Fontan procedure between October 1997 to May 2005. The mean age of the patients was $17.3{\pm}10.8$ days (range: 9~36 days) at the $1^{st}$ staged operation, $8.9{\pm}7.1$ months (4.6~23.3 months) at the $2^{nd}$ staged operation (the Bidirectional Glenn procedure) and $32.4{\pm}9.8$ months at the final staged operation (the Fontan procedure). During the $2^{nd}$ staged operation, one of the patients received tricuspid valve repair due to regurgitation. All the patients underwent an extracardiac Fontan procedure using Gore-Tex conduit (20 mm: 2 patients, 18 mm: 4 patients) and one of them required fenestration. Result: 21 patients underwented a Norwood procedure. There were 7 early deaths and 4 interstage deaths. Bidirectional cavopulmonary shunt was performed in 10 patients and the Fontan procedure was done in 6 (mortality: 1 patient, Flow up loss: 1 patient, Awaiting a Fontan procedure: 2 patients). After the Fontan procedure, there was no complication except for one case of post operative bleedings. All the patients had good ventricular function and 2 had grade I tricuspid regurgitation, as noted on their echocardiography. The average follow up period after the Fontan procedure was $19.6{\pm}14.9$ months (range: 1.5~39.1 month). All the patients had normal sinus rhythm and they were put on aspirin and cardiac medication. During follow up period, all the patients had a good functional status (NYHA functional class I). Conclusion: All the patients who suffered with hypoplastic left heart syndrome and who underwent a Fontan procedure achieved a good hemodynamic and functional status, even though there was a relatively high operative mortality rate after stage I Norwood palliation. Therefore, thise staged operation should be strongly recommended as an important surgical strategy for treating hypoplastic left heart syndrome.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.33-42
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• 2018

The tropical peatlands have been deforested and converted to agricultural and plantation areas in Indonesia. To manage water levels and increase the overall productivity of crops, canals have been constructed in tropical peatlands. The canals destructed the structure of the tropical peatlands, and increased the subsidence and fire hazard risks in the region. The Indonesian government enacted regulations and a moratorium on tropical peatlands, in order to reduce degradation. A practical method under the regulations of rewetting tropical peatlands was to permit a canal blocking. In this study, four canal blocking projects were investigated regarding their planning, construction priority, design, building material, construction, monitoring, time and costs associated with the canal blockings. In the protected areas, regulations restricted the development of the tropical peatlands areas that were noted as deeper than 3 m, and the administration stopped issuing new concessions for future work projects for this noted criteria of land use. A noted purpose of canal blockings in these areas was to effectuate the restoration of the lands in the region. The main considerations of the restoration efforts were to maintain a durability of the blockings, and to encourage the participation of the area stakeholders. In the case of a concession area, regulations were set into place to restrict clear-cutting and shifting cultivation, and to maintain groundwater level in the tropical peatland. The most significant priorities identified in the canal blocking project were the efficiency and cost-effectiveness of the project. Nevertheless, the drainage of tropical peatlands has been continued. On the basis of a literature review on regulations and rewetting methods in tropical peatlands of Indonesia, we discussed the improvements of the regulations, and adequate canal blockings to serve the function to rewet the tropical peatlands in Indonesia. Our results would help establishing an adequate direction and recommended guideline on viable rewetting methods for the restoration of drained tropical peatlands in Southeast Asia.