• Journal of Chest Surgery
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• v.31 no.12
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• pp.1172-1182
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• 1998

Background: Primary goal of anticoagulation treatment in patients with mechanical heart valve is the effective prevention of thromboembolism and safe avoidance of bleeding as well. Material and Method: Two-hundred and nine patients with the St. Jude Medical prosthesis operated on between 1984 and 1995, for mitral(MVR 122), aortic(AVR 39) and double mitral and aortic valve replacement(DVR 48) respectively, were studied on the practically achieved levels of anticoagulation and the clinical outcomes. Patients were on Coumadin and followed up by monthly visit to outpatient clinic for examination and prothrombin time measurement to adjust the International Normalized Ratios(INRs) within the low-intensity target range between 1.5 and 2.5. Result: A total anticoagulation follow-up period was 1082.0 patient- years(mean 62.1 months) and INRs of 10,205 measurements were available for evaluation. The accomplished INRs among the replacement groups were not significantly different and only 65% of INRs were within the target range. And, in individual patients, only 37% of patients had INRs included within the target range in more than 70% of tests during follow-up period. The levels of INRs in patients with atrial fibrillation, which was found in 57% of patients, were definitely higher than the ones measured in patients with regular rhythm(p<0.001). Thromboembolisms were experienced by 15 patients with the incidence of 1.265%/patient- year(MVR 1.412%, AVR 0.462% and DVR 1.531%/patient-year) and major bleeding by 4 patients with the incidence of 0.337%/patient-year(MVR 0.424%, AVR none and DVR 0.383%/patient-year). Frequent as well as prolonged missing of prothrombin time tests was the main risk factor strongly associated with the thromboembolic complications(odds ratio 1.99). The proportion of INRs within target range of less than 60% in individual patient was the highly significant risk factor of both thromboembolic and overall embolic and bleeding complications(p<0.004 and p<0.002 respectively). Conclusion: In conclusion, the low-intensity therapeutic target range of INRs was adequate in patients with AVR and in sinus rhythm. However, the patients with replacement of the mitral valve were more likely to require higher target range of INRs, especially in the presence of atrial fibrillation, to achieve the practical levels of anticoagulation enough to prevent thromboembolic complications effectively. For the higher therapeutic target range of INRs between 2.0∼3.0, further accumulation of clinical evidences are required. It is highly desirable to improve the patients' compliance under continuous instructions in visiting outpatient clinic and in taking daily Coumadin without omission and to keep INRs consistently within optimal range with tight control for minimization of chances and of periods of exposure to the risk of complications. And, particularly, patients with high risk of complications and with wide fluctuation of INRs should be better managed with frequent monitoring anticoagulation levels.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.585-590
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• 2004

Bronchogenic cyst is a rare and benign disease. Because of its complication or associated disease, Bronchogenic cyst requires surgical treatment. Recently, with the development of diagnostic methods, its incidence has increased. So we reviewed our results from the past 30 years. Material and Method: We reviewed 27 cases surgically treated from March 1971 to March 2003. This investigation is designed to illustrate the peak age incidence, sex ratio, symptoms, anatomic location, radiologic imagings, associated diseases, operative methods, postoperative pathologic findings and postoperative complications. Result: The peak age incidence laid in the 1st to 3rd decade and the ratio of male and female was 1 : 1.5. The most common complaints were cough and dyspnea, but some had hemoptysis. There were 22 cases (81%) of Intrapulmonary bronchogenic cysts and 5 cases(19%) of mediastinal bronchogenic cysts. Thirteen cases (48.1%) showed cystic lesion in simple chest X-ray. Ten cases showed cystic lesion among 13 cases that had taken computed tomography. We found associated disease in 15cases (56%). The inflammatory diseases from infection were many in intrapulmonary bronchogenic cysts and especially, one case showed carcinosarcoma. Mitral regurgitation and Bronchial obstruction could be seen in mediastinal bronchogenic cysts. The 13 cases (48%) were managed by lobectomy, and cystectomy, pneumonectomy, and segemental resection were done in 7 cases (26%), 4 cases (15%), 3 cases (11%) respectively. Cystic contents were mucus in 9 cases, pus in 9 cases, blood in 2 cases, and carcinosarcoma in 1 case. Bronchotracheal communications were in 13 cases (48%). Five cases showed Postoperative complications, which were pneumothorax, empyema, bleeding. Postoperative death could not be found. Conclusion: Almost all patients had clinical symptoms. Severe complications could be associated with bronchogenic cysts. Recently, With the development of diagnostic methods, preoperatively accurate diagnosis is possible; therefore, invasive study has decreased. Bronchogenic cyst is a benign disease. However, because of its clinical symptoms, complications, and possibility of malignant change, immediate surgical treatment is needed.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.364-374
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• 2010

Background: We assessed the early and mid-term results of the modified Norwood procedure for first-stage palliation of hypoplastic left heart syndrome (HLHS) and its variants to identify the risk factors for hospital mortality. Material and Method: Between March, 2003, and December, 2009, 23 patients (18 males and 5 females) with HLHS or variants underwent the modified Norwood procedure. The age at operation ranged from 3 to 60 days (mean, $11.7{\pm}13.2days$) and weight at operation ranged from 2.2 to 4.8 kg (mean, $3.17{\pm}0.52kg$). We used a modified technique that spared the anterior wall of the main pulmonary artery in 20 patients. The sources of pulmonary blood flow were RV-PA conduit in 15 patients (group I) and RMBTS in 8 (group II). Follow-up was completed in 19 patients (19/20, 95%) in our hospital (mean $26.0{\pm}22.8months$). Result: Early death occurred in 3 patients (3/23, 13%), of whom 2 had TAPVC. Fourteen patients underwent subsequent bidirectional cavopulmonary connection (BCPC, stage 2) and seven underwent the Fontan operation (stage 3). Three patients died between stages, 2 before stage 2 and one before stage 3. The estimated 1-year and 5-year survival rates were 78% and 69%, respectively. On multivariate regression analysis, aberrant right subclavian artery (RSCA) and associated total anomalous pulmonary venous connection (TAPVC) were risk factors for hospital mortality after stage 1 Norwood procedure. Conclusion: HLHS and its variants can be palliated by the modified Norwood procedure with low operative mortality. Total anomalous pulmonary venous connection adversely affects the survival after a stage 1 Norwood procedure, and interstage mortality rates need to be improved.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.456-463
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• 2009

Background: Although the reports on re-operative coronary revascularization (redo-CABG) have increased, there are only limited reports on redo-CABG using arterial grafts. The aim of this study was to analyze the safety and feasibility of using various arterial grafts for redo-CABG. Material and Method: A consecutive series of patients who underwent 33 redo-CABGs from March 2001 to July 2008 were retrospectively reviewed. We performed conventional CABG in 17 patients, on-pump beating CABG in 7, off-pump CABG in 7 and minimally invasive direct coronary artery bypass in 2. The grafted that were used included 34 internal thoracic arteries (ITA), 14 radial arteries, 14 right gastroepiploic arteries and others. Arterial composite grafts were constructed in 26 patients. Of these, a previously patent in-situ left ITA was re-used as the in-flow of a composite graft in 10 patients. Result: No hospital deaths or major wound problems occurred. The post-operative complications included 2 myocardial infarctions (6%), 1 intra-aortic balloon pump insertion (3%), 5 cases of atrial fibrillation (15.1 %) and 3 neurologic complications (9.1%). The meanfollow-up duration was 31.1$\pm$22.7 months and the 3 year survival rate was 86.4%. There were 4 late deaths (2 cardiac deaths) and no recurrent angina during the follow-up period. Conclusion: Redo-CABG with using various arterial grafts is currently a safe, feasible procedure, but further investigation and long term follow-up are needed.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.83-107
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• 2009

The purpose in this study was to provide a basic resource for enhancing teachers' professional competence by examining how the Home Economics(HE) teachers had formed, developed, and introspected the pedagogical content knowledge in the HE classes of secondary schools. Data were collected through in-depth interviews with six HE teachers working at secondary schools. NVivo program, a kind of CAQDAS was used to analyze the data inductively. This study revealed that the HE teachers reflectively introspected the pedagogical content knowledge in Home Economics Education(H-PCK) as follows: First, as for knowledge of perspective on Home Economics Education(HEE), the research participants encouraged students to solve practical problems regarding the objective of HEE. They tried to foster the students' critical thinking ability related to the daily life. They made eager efforts to achieve the mission of HEE as a practical science. Second, as for knowledge of HE curriculum, the research participants mentioned that there was lack of systematic approach concerned with curriculum development. While reorganizing, they always paid attention to its relation to the students' daily lives, to the relationship between the curriculum contents and the social context. Third, as for knowledge of teaching strategies on practical problem-based instruction, the research participants developed the practical problem-based instruction skills. They mentioned students' difficulties in relating the practical problem-based instruction, too. Fourth, regarding knowledge of context, as teachers mostly prepared for progressed instruction alone without communicating with colleagues in the same school, they yearned for and also formed networks with other HE teachers in order to overcome their limitations.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.925-934
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• 2016

For students, astronomy is not only interesting but also difficult to learn. However, there is a limit in learning astronomy in a school science setting since astronomy is vast subject. Fortunately, science museums can be helpful in overcoming this limitation. Experiences in science museum provide something that any descriptions or illustrations cannot give. Therefore, to maximize the educational effect, it is necessary to look at astronomical exhibits regarding the educational aspects and complement them. For these reasons, the purpose of this study is to investigate characteristics of exhibitions related to astronomy and how much the exhibitions reflect the contents of their science curricula. We selected famous science museums in Korea, America, and Japan and analyzed characteristics of their astronomy exhibition. We analyze these characteristics in the aspects of exhibition technology & media, presentation method and activity types. Also, this study figures out how content of exhibitions are connected to school science curriculum. The results are summarized as follows: First, Science Museums of America and Japan utilize interactive exhibits to raise participation. It implies that Science Museum of Korea needs Interactive Exhibits that provide a realistic experience of the universe. Second, the astronomy exhibits reflect some of the learning elements of their science curricula concerned with astronomy. However, these astronomical contents are included selectively and not according to their required curriculum. It means that many students lack the opportunity to study Astronomy in their schools. Therefore, the astronomy museum must reflect learning elements of science curricula concerned with astronomy in the exhibits.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.177-214
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• 2016

During more than 20 years of practice, Civil Aviation Law has experienced three times of amendments since it was enacted in 1995. But these revisions are limited to the technical level. The problems and limitations have become increasingly prominent in its implementation. Firstly, the civil aviation law is the result of interests game among several departments and some legal issues was left behind and the regulation was very vague as a result. Secondly, the process of aviation legislation is the process that the country has undergone profound changes and social transformation. The 20 years is long enough for the society to undergo tremendous changes and 1995 version of civil aviation law does not keep pace of development of economy. There was a serious lag between reality and the law. In order to actively promote the development of the aviation industry and overcome implementation issues of the Civil Aviation Law, Civil Aviation Administration of China (CAAC) initiated modification procedure the law and published new draft of Civil Aviation Law in August 2016. The spirit of this modification is to learn and absorb new achievements of domestic and foreign legislation and the International Convention on civil aviation. Furthermore, the purpose of the revision is to provide favorable policy for the development of civil aviation industry and improve aviation safety and supervision, strengthen and protection of consumer rights and interests, to enhance the safety of civil aviation activities, and promote the development of general aviation. This revision concerned to the 78 articles which are revised or deleted and 24 articles added. The highlights of the draft include but not limited to the enhancement of security management, clarification of the main responsibility for production safety. And also it added the provisions related to the construction of effective tracking capability of public air transport enterprises and license system on the transport of dangerous goods. Compared with the existing civil aviation law, the draft has made a great improvements. But there are several deficiencies and limitations in the drafts. These problems need to be supplemented and perfected through further amendments in near future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1439-1446
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• 2014

The purposes of this study were to analyze recognition and preference of native local foods in elementary school students in Gyeongsang-do and Jeolla-do, as well as compare regional differences in recognition and preference of native local foods between students in Gyeongsang-do and Jeolla-do. A survey was conducted on 300 elementary school students located in Gyeongsang-do and Jeolla-do. The results of this study were as follows. First, there was no significant difference in terms of recognition score of overall native local food between students in Gyeongsang (9.43 out of 20 dishes for 254 students) and students in Jeolla (9.13 out of 20 dishes for 261 students). The recognition levels (4.88 out of 10 dishes) of native local foods in students in Gyeongsang-do were significantly higher than those (4.40 out of 10 dishes) in Jeolla-do (P<0.001). Second, the preference level (2.91 points) for native local food in students in Gyeongsang-do was significantly higher than that (2.72 points) in students Jeolla-do (P<0.001) based on a 5-point Likert scale. The preference level (3.03 points) of students in Gyeongsang-do for native local food was significantly higher than that (2.80 points) of students in Jeolla-do (P<0.001) based on a 5-point Likert scale. In conclusion, students in Jeolla-do perceived native local foods in Jeolla-do and Gyeongsang-do impartially, whereas students in Gyeongsang-do perceived native local foods better. The overall sample of elementary school students preferred native local food in Gyeongsang-do to native local food in Jeolla-do. Thus, there were regional differences in terms of recognition and preference of native local foods in elementary school students. To enhance the recognition and preference of native local foods in Jeolla-do, food culture and dietary education should be carried out.

• Journal of Korean Elementary Science Education
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• v.24 no.3
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• pp.259-267
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• 2005

This study was to investigate the elementary students' preconception on the brightness of electric bulb and degree of consistency on their preconceptions. Participants were 160 students of fifth graders in Seoul area. They had already teamed about the brightness of series circuit and parallel circuit of batteries. After they solved six problems in the same context, we provided them a pair of circuit which was an anomalous situation. And then they conducted CCLT (Cognitive Conflict Level Test). Elementary school students showed various preconceptions when they explained the light of bulb of two Simple electric Circuits. Many Students Consistently Showed the Scientific misconceptions like 'the light of bulb of two simple electric circuits was that the more batteries and the fewer bulbs were brighter.' The level of consistency that students presented scientific misconceptions was grouped all of four, such as 'high, middle, low, and nothing.' Therefore the higher scientific achievement they have, the higher consistency they have. As the students had high consistency level, they revealed high cognitive conflict level significantly. This high consistency will help them to change their preconception on the brightness of electric bulb and their cognitive conflict.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.1-15
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• 2015

In order to outline the kinematics and movement history of a new Quaternary fault, Jingwan Fault in Dangjin, West Korea, we analyzed the geometry of the fault zone composed of a few gouge zones, and made ESR dating for fault gouge materials. The $N55^{\circ}E$ striking Jingwan Fault is a normal fault and exhibits a gradual change in dip (gentle in the lower part, steep in the upper part), indicating a listric fault. As for the fault gouge zone, its thickness varies and reaches 2~3 cm in the lower part or between basement rocks, and 20~30 cm in the middle-upper part or between the basement and Quaternary deposit. It is observed in the latter case that more than three gouge zones develop with different colors, and branch out and re-merge, or they are partly superimposed, indicating different movement episodes. The cumulative displacement is estimated to be about 10 m using the geological cross-sections, from which it is inferred that the total length of fault may be about 2.5 km on the basis of the empirical relation between cumulative displacement and fault length. Therefore, a more study would be needed to verify the entire fault length. The results of ESR dating for three gouge samples at different spots along the fault yields ages of $651{\pm}47$, $649{\pm}96$, and $436{\pm}66ka$, indicating at least two movement episodes. Slickenlines observed on the fault planes indicate a pure dip slip (normal faulting), which suggests that the ENE-WSW trending Jingwan Fault was presumably moved under a NNW-SSE extensional environment.