• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.777-783
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• 2004

하천 세내지 주변은 급속한 시가지 조성과 인구밀집으로 유역의 불투수층이 증가하여 홍수도달시간이 짧아지고 홍수유출량이 증가하고 있다. 또한 엘리뇨${\cdot}$라니냐 등의 이상기후로 홍수사상의 발생 빈도와 규모가 증가하면서 홍수피해도 대형화되어 가고 있다. 그러나 치수사업은 다른 공공사업에 비해 경제성이 저평가 되어 투자우선순위가 밀려 사업시행이 지연되고 예방적 차원의 대책도 미흡하여 피해가 증가하는 악순환이 계속되고 있다. 따라서 본 인구에서는 우리나라의 치수경제성 분석에 있어 계량화하지 못하고 있는 자산이용고도화 효과를 치수안전도와 더불어 분석하고자 한다. 자산이용고도화는 치수사업 시행으로 해당지역의 치수안전도 향상에 따른 자산가치의 상승을 말하는데, 특정지역의 자산가치를 가장 객관적으로 표현할 수 있는 공시지가를 근거로 분석을 수행하였다. 치수사업 시행으로 인한 편익과 하천 특성에 따른 지가변동률의 차이가 통계적으로 유의성이 있는지를 분산분석을 통해 검증하였으면, 자산가치의 상승을 순수 연평균지가변동률로 나타내었다. 치수안전도는 홍수피해 잠재성과 홍수방어능력으로 구분하였는데 홍수피해 잠재성은 도시화율에 따라 구분하였고, 홍수방어능력은 홍수량의 빈도해석과 불확실성을 고려하여 조건부 비초과확률로 나타내었다. 본 연구에서는 소도시 지역(경안천, 복하천, 청미천)을 대상으로 200년 빈도의 홍수사상에 내해 10년, 50년 설계빈도로 건설된 제방의 조건부 비초과확률을 산정하여 지가변동률의 추이를 비교 분석하였다. 분석 결과, 소도시 지역에서는 조건부 비초과확률이 $10\%$ 상승했을 때 순수 연평균지가변동률이 5배정도 상승함을 알 수 있었다.다시 입력자료로 사용하는 업데이트 방식을 사용하기 때문에 예측결과의 오차가 완전하게 보정되지 않으면 다음 결과에 역시 오차를 주게 되어 오차보정이 상당히 중요하다는 것을 알 수 있었다. 오차를 보다 효과적으로 보정하기 위해서는 퍼지제어에 사용되는 퍼지규칙의 수를 늘리고, 유입량에 직접적인 영향을 주는 강우량과 연계한 2변수의 Fuzzy-Grey 모형을 이용한다면 보다 정확한 유입량 예측이 가능할 것으로 사료된다.이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.81-88
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• 2018

The present study evaluated the effective arrangement approach of transverse reinforcement in the jacket section for seismic strengthening of reinforced concrete columns. To simulate the full-scale columns, the section dimensions were determined as $450{\times}450mm$ for non-seismic existing columns and $750{\times}750mm$ for section enlargement strengthening columns. Over-lapped channel-shape bars and prefabricated bar units were proposed for closed-hoops in the jacket section, and conventional cross-ties anchored into existing columns and V-ties were considered for the supplementary ties. Test results showed that the axial capacity of the existing column and section enlargement columns with over-lapped channel-shape hoops was similar to the nominal strength calculated using ACI 318-14 procedure whereas the section enlargement column with prefabricated bar units possessed 1.25 times higher axial capacity than the nominal prediction. Furthermore, the axial ductility ratio of the section enlargement column with prefabricated bar unit was 139% higher than that of the existing column despite the potential size effect on ductility of concrete. Thus, it can be concluded that the developed prefabricated bar unit technique is practically useful for preventing the premature buckling of longitudinal reinforcement and confining core concrete in the section enlargement strengthening columns.

• 한국해양학회지
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• v.29 no.2
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• pp.107-118
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• 1994

An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

• International Area Studies Review
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• v.20 no.1
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• pp.277-295
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• 2016

It is undoubtedly true that national security in Korean peninsula is on the road to destabilization. The main factors are known to be North Korea's development and experiment on nuclear arms, especially the forth nuclear experiment on January 6th, ICBM launch February 7th, and encroachment upon the territory the NLL on the 8th along with the shutdown on Gaeseong Industrial Complex. Also, China's trouble with other nations over sovereignty over islands in the South China Sea and the fact that Japan's government is veering to the right side and having territorial dispute are making the case worse. Nations in Northeast Asia are striving to obtain the interest for the sake of their own country. In order to do so, they're walking the path to achieve national security. Until then, they are not so willing to participate foreign matters or economical race. Even in our perspective, these issues are many of the main problems which our country is currently facing. However, it is important for them to avoid making policies which may take away the citizen's happiness. The number one priority for the nation or any form of a group is to act in the best interest for the national security and the citizen's happiness. They are the main factors why a nation could exist. They are the symbols of a nation's sovereign authority. Countries outside are proving it by increasing their national defense budget even in this unprecedented economical crisis. If we are willing to stay the same as ever, the disparity in the military force will not be the same in the future. In conclusion, the study examines the problem which changes in Northeast Asia's defense environment could bring and the appropriate amount of national defense budget in order to support the nation's integration of its abilities to move toward South and North Korea's unification.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.271-276
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• 2005

We analysed differences in operative methods and postoperative outcome according to the severity of preoperative cyanosis in adult ToF (Tetralogy of Fallot) patients. Material and Method: From August 1989 to June 2001, thirty three adult patients, 18 females and 15 males, underwent total correction for ToF. Their age ranged from 15 years to 54 years (median: 34). Patients were divided into 2 groups by preoperative $SaO_2$ (arterial oxygen saturation): group I$(n=cyanotic,\;SaO_2\;\geq94\%)$ and group II $(acyanotic,\; SaO_2\geq95%)$. Preoperative median hemoglobin level was higher in group I compared to group II (17.5 g/dl vs 15 g/dl). Postoperative follow-up duration ranged from 1 to 94 months (670 patient-month, median: 14 months), and 63 two-dimensional echocardiographic examinations were done during this period. Result: There were no early or late mortality. With regard to RVOT (right ventricular outflow tract) reconstruction, trans-annular patch and RV-PA extracardiac conduit were used in 7 and 3 patients respectively, and all of them belonged to group I. In group I, cardiopulmonary bypass time, aortic cross-clamping time, ICU day, hospital day were significantly longer than in group II, and postoperative inotropic support was significantly greater than in group II. There was no ventricular arrhythmia in both groups, and one patient in group I suffered from atrial arrhythmia, which was resolved spontaneously after tricuspid and pulmonary valve replacement. During follow-up periods, functional class, residual RVOT stenosis and pulmonary regurgitation, tricuspid regurgitation, occurrence of ventricular and atrial arrhythmias were comparable between two groups. Conclusion: In adult ToF patients with severe preoperative cyanosis, more aggressive RVOT reconstruction and careful postoperative care are mandatory. However intermediate-term outcome of this group of patients is comparable to the patients with minimal or no preoperative cyanosis.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.339-345
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• 2002

Purpose : The purpose of this study was to evaluate the clinical usefulness of chest high-resolution computed tomography(HRCT) in patients with chronic coughs or persistent wheezing with normal chest X-ray finding. Methods : We reviewed the charts, chest X-rays, and HRCT findings of patients with chronic coughs or persistent wheezing of less than 2 years of age. The records were sourced from the Department of Pediatrics, Inha University Hospital covering the period from July, 1999 to June, 2000. Chronic cough was defined as a cough which was prolonged for more than 3 weeks. Results : The sample consisted of 24 patients(male 15 and female 9, mean age $4.7{\pm}3.8$ months old). Among them, 16 patients showed normal findings(66.7%) and 8 patients showed abnormal (33.3%) in simple chest X-rays. Among 16 patients who had the normal chest X-rays, 13 patients showed abnormal chest HRCT findings(81.3%) such as air space consolidation of the dependent portion(62.5%), bronchiolitis obliterans(12.5%), and bronchopulmonary dysplasia(6.3%). Conclusion : We suggest that the chest HRCT is a useful diagnostic tool in the evaluation of patients with chronic cough or persistent wheezing with normal chest X-ray, especially below 2 years of age.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.337-341
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• 2006

Objectives : Endobronchial anthracofibrotic pigmentation, which presents as dark black or brown pigmentation mucosal changes of multiple bronchi combined with bronchial fibrosis and obstruction, is not a rare finding when performing diagnostic bronchoscopy for Koreans. This study was performed to define the clinical characteristics and to determine the association of these finding with the Korean life style and such other diseases as coal workers, pneumoconiosis or tuberculosis in the patients with anthracofibrotic pigmentation. Methods : This retrospective analysis was conducted on 70 (5.2%) patients with endobronchial anthracofibrotic pigmentation, among a total of 1340 patients who underwent bronchoscopy. The distinctive clinical features, the personal life style, the past medical history, the histology and microbiology, the radiologic finding and the natures of the bronchoscopic lesions were analyzed. Results : This mean age of the patients with anthracofibrotic pigmentation was $60.6{\pm}9.2$ year old and the male to female ratio was 1:1.7. The common respiratory symptoms of these patients were coughing and sputum (81%, 57/70), and this was followed in order by dyspnea and hemoptysisir. The symptoms were not related with smoking and an occupational history such as being a coal worker and so on. Pneumonia was most common finding on the radiologic studies. On bronchoscopy, the right middle lobe bronchus was most commonly involved. The most common associated disease was tuberculosis, and 40 cases (57.1%) were diagnosed by AFB staining, TB PCR, bronchoscopic guided tissue biopsy and a past history of tuberculosis. Other diseases related with anthracotic pigmentation were hypertension, diabetes, COPD, lung cancer, pneumoconiosis and asthma. Conclusion : These results suggest that endobronchial anthracofibrotic pigmentation was mostly related with pulmonary tuberculosis rather than with coal- related disease. Endobronchial anthracofibrotic pigmentation was more prevalent in older age females in Korea.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.321-329
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• 2006

Background : To evaluate the clinical characteristics of lung cancer patients in Korea, where there is a higher number of smokers than in Western countries. Methods : A retrospective study was performed on 1655 lung cancer patients, who were diagnosed at a university hospital between September 1996 and August 2005. Age, gender, cell types and clinical stage were analysed. Of 941 patients, who responded to a questionnaire at the time of diagnosis, the smoking habits, occupational history, family history of lung cancer in the first-degree relatives, coexisting diseases (diabetes mellitus and cardiovascular disease), body weight loss, ECOG performance status and presenting symptoms, were examined prospectively. In addition, coexisting diseases including chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and active pulmonary tuberculosis were evaluated. Results : Of the 1655 patients, the male to females ratio was 3.6. Squamous cell carcinoma was the most common cancer whereas adenocarcinoma was more common in lifetime nonsmokers or women. 19.9% of the patients were non smokers and 80.1% ever smokers. Since 2000, there was an increase in the incidence of adenocarcinoma with a corresponding decrease in the incidence of squamous cell carcinoma. 6.2% of patients were asymptomatic. A coincident diagnosis of chronic obstructive pulmonary disease, cardiovascular disease, diabetes mellitus, active pulmonary tuberculosis, and idiopathic pulmonary fibrosis was made in: 44.1%, 22.2%, 10.7%, 3.9%, and 1.6% of patients, respectively. A positive family history of lung cancer in the first-degree relatives was identified in 4.4% of patients. An occupational history relevant to lung cancer was identified in 12.2% of patients. Conclusion : There is a high proportion of cigarette smokers in Korean lung cancer patients. The most common cell type was squamous cell carcinoma. However, a more detailed, prospective study of the clinical characteristics will be needed to better characterize lung cancer in Korea.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.1
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• pp.28-35
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• 2007

Purpose: The aim of this study was to evaluate the clinical usefulness of ultrasound examination of children performed by a pediatrician. Methods: One thousand children who presented with symptoms of a gastrointestinal disorder and underwent abdominal ultrasound evaluation in the Department of Pediatrics, between January 2003 and June 2006, were included in this study. We analyzed the patient's medical records and ultrasound results retrospectively. Results: Among the 1,000 patients, 58.4% were male and 41.6% were female. The mean age of the patients was $4.7{\pm}4.0$ years. The main reasons for ultrasound were abdominal pain (43.9%), vomiting (17.3%), elevated liver enzymes (11.8%), and jaundice (9.8%). Abnormal ultrasound findings were present in 57.9% of cases. The major abnormal findings were mesenteric lymphadenitis (29.2%), fatty liver (12.1%), hepatitis (6.4%), hepatosplenomegaly (6.2%), and acute appendicitis (4.8%). The time interval between the initial medical evaluation and the ultrasound evaluation was within 24 hours in most cases (78.5%). The main findings in children with abdominal pain were mesenteric lymphadenitis (32.6%), fatty liver (5.9%), intussusception (2.7%), and acute appendicitis (2.7%). The main findings in children with vomiting were mesenteric lymphadenitis (12.7%), hypertrophic pyloric stenosis (10.4%), and acute appendicitis (3.5%). The major ultrasound findings in children with urinary tract diseases were hydronephrosis (45.4%), urolithiasis (21.5%) and cystic renal disease (18.1%). Conclusion: Ultrasound examination played an important role as a non-invasive and prompt screening examination for detection of abdominal diseases. Ultrasound was an important tool for pediatricians to determine timely information for patient management.

• Journal of Chest Surgery
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• v.40 no.10
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• pp.659-666
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• 2007

Background: Preserving the subvalvular apparatus after mitral valve replacement (MVR) results in better ventricular function and a better outcome. In conjunction, mitral valve repair (MVr) is associated with a better outcome, yet little is known about the hemodynamics and outcomes between patients undergoing MVr and MVR with chordal preservation. We prospectively evaluated the hemodynamic changes and outcomes of patients undergoing MVr and MVR with chordal preservation. Material and Method: Fifty-four patients with mitral regurgitation (MR) who under-went MVR with chordal preservation (n=21) or MVr (n=33) were studied. The patients' characteristics, the intra-and postoperative hemodynamics and the use of cardiac medications, the postoperative outcome and the complications were recorded during the hospital stay. All the patients were followed up for at least 6 months post-operatively for determining their morbidity and mortality. Result: The patients' characteristics were similar between the groups, except for the presence of atrial fibrillation and congestive heart failure which was more frequent in the MVR group. Also, the preoperative left ventricular ejection fraction was lower in the MVR group than in the MVr group ($64{\pm}9%$ versus $69{\pm}5%$, respectively, p=0.043). There were no significant differences of the hemodynamics between the groups. The use of inotropic drugs and pacemakers during the 12hrs postoperatively was more common in the MVR group than in the MVr group (48% versus 24%, p=0.025 and 52% versus 24%, p=0.035, respectively). The other postoperative outcomes were similar in both groups for at least the 6 months follow-up period. Conclusion: MVR with chordal preservation was comparable with regard to the hemodynamics and clinical outcomes, supporting the beneficial effect of preserving the subvalvular apparatus after MVR.