• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.792-797
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• 2002

In the following paper two algorithms, suitable for the analysis of panchromatic data as provided by KOMPSAT-1 will be presented. One is a texture analysis which will be used to create a settlement mask based on the variations of gray values. The other is a fusion algorithm which allows the combination of high resolution panchromatic data with medium resolution multispectral data. The procedure developed for this purpose uses the spatial information present in the high resolution image to spatially enhance the low resolution image, while keeping the distortion of the multispectral information to a minimum. This makes it possible to use the fusion results for standard multispecatral classification routines. The procedures presented here can be automated to large extent, making them suitable for a standard processing routine of satellite data.

• 한국항공운항학회지
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• 제30권4호
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• pp.132-144
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• 2022

In response to the recent surge in aviation demand, major airport and aviation authorities continue to make efforts to formulate arrival procedures that take into account efficient aircraft separation, noise and environmental issues related to carbon (CO₂) emissions. In order to ensure efficient traffic control and environmental issues, as a result, a new concept Trombone, Point Merge, etc. have been introduced and widely used. However, these new concept incisions are becoming a factor that hinders operational efficiency and stability due to the restricted domestic airspace such as military airspace and excessive constraints of altitude, speed, etc. which do not reflect the concept of continuous descent operation and eventually needs to be modified to make continuous descent operation as feasible as possible. We herewith analyze and propose the way of improving flight safety and efficiency in the arrival operation procedure by supplementary modification which consequently contribute to the aviation industry international competitiveness.

• 대한종양외과학회지
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• 제14권2호
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• pp.95-101
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• 2018

Purpose: The standard treatment of esophageal cancer is the Ivor-Lewis operation, which consists of an abdominal phase involving gastric tube formation, and a chest phase involving esophagectomy and anastomosis. We aimed to report our experience of performing thoracic esophagectomy with the laparoscopic gastric pull up (LGPU) technique and its surgical outcomes. Methods: Clinicopathologic data and short-term surgical outcomes of 14 patients who underwent LGPU for thoracic esophageal cancer from August 2008 to May 2016 were retrospectively reviewed. Results: Mean age of the patients was 62.3 years and mean body mass index was $21.7kg/m^2$. Eleven patients had medical comorbidities. Patients' mean American Society of Anesthesiologists score was 2. Mean operation time was 428.5 minutes, with the mean abdominal operation time being 138.9 minutes. There was no open conversion case. Three patients had pneumonia, three patients had surgical site infection, and one patient had subcutaneous emphysema within 30 days after surgery. One patient had minor anastomosis site leakage. There was one 30-day mortality case. One patient with postoperative aspiration pneumonia developed acute respiratory distress disease, and died due to sepsis. Mean postoperative intensive care unit stay was 3.5 days, and mean postoperative hospital stay was 20.6 days. Nasogastric tubes were removed on average at 3.4 days, and mean oral intake time was 3.4 days. Conclusion: If the gastrointestinal surgeon has extensive experience in laparoscopic procedures, LGPU will be a safe and feasible technique for thoracic esophagectomy in patients with intrathoracic esophageal cancer.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.97-106
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• 2020

본 연구의 목적은 소프트웨어 공인시험기관에 국제 표준 ISO/IEC 17025 요구사항을 기준으로 ISO/IEC/IEEE 29119 소프트웨어 시험 절차와 ISO/IEC 25023 소프트웨어 시험 평가 항목을 적용하는 방법에 대한 연구이다. 연구의 방법으로 시험기관에 적용하는 전체 요구사항은 ISO/IEC 17025를 기준으로 ISO/IEC/IEEE 29119와 ISO/IEC 25023을 매핑하여 분석되었다. 해당 매핑 분석에 따라 시험기관 운영을 위한 품질 매뉴얼과 절차서, 지침서는 총 29 종류의 문서를 작성하였다. 연구의 결과 시험기관 관리 시스템은 분석된 전체 요구사항 결과를 적용하여 Confluence 6.15 소프트웨어를 이용하여 구현하였고 시험절차서, 문서, 기록은 시험관리 시스템에 저장하여 운영하도록 하였다. 시험기관운영 적합성 검증은 서울 소재 LG전자 SW공인시험소에서 KOLAS 평가사에 의하여 문서 심사 및 현장 심사로 진행이 되었다. 결론적으로 시험기관 관리 시스템과 시험기관의 운영은 KOLAS의 심사 평가를 통하여 적합하다는 것을 확인할 수 있었고 이전 연구 사례와 비교하여 효과적으로 시험기관 운영과 전체 일정을 단축할 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.195.2-195.2
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• 2011

The borehole heat exchanger of Geothermal Heat Pump (GHP) system should be sustainable and cost effective for long term operation. To guaranty the performance of the system thermal Response Tests (TRTs) with simple recommended procedures have been applied in many countries. Korea government developed a standard TRT procedure in order to control the quality on GHP projects. In the TRT procedure interpretation method has a rule that data set has to be interpreted by the line source model(LSM). The LSM employes some assumptions that surrounding medium is homogeneous and the line source is infinite and constant heat flux, however real ground condition is unisotropic and heterogeneous, and showing regional or local ground water flows in many cases. We need to develope improved evaluation models to estimate accurate ground thermal conductivity with respect to geological and influence of ground water because current TRT standard test procedure has limitations to be applied for every locations and system. This study surveyed the uncertainty of the thermal parameters from the interpretation method considering different evaluation period. The interpretation of 208 TRT data sets represents limitations of LSM application that some obtained ground thermal conductivities are statistically unstable and convergence time of ground thermal conductivity over test period shows trends responding the length of test period. This evaluation study will be helpful to provide some effective procedure for the thermal parameter estimation and to complement current TRT standard procedure.

• 한국진공학회지
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• 제20권6호
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• pp.387-394
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• 2011

진공펌프의 운전성능을 나타내는 가장 중요한 지표 중의 하나인 배기속도 측정에 관해서는 많은 연구를 통해 정립된 이론에 따라 표준장치와 측정절차에 대한 규격이 만들어지고 널리 활용되고 있다. 그러나 실제 펌프 배기속도 측정 시 이상적인 조건에 비해 변형이 불가피할 때가 있고 그 영향을 간과하면 큰 측정오차를 유발할 수 있다. 본 논문에서는 배기속도를 측정하기 위한 이상적인 또는 실용적인 다양한 방안들이 가지는 물리적 특징과 구조적 오차에 대해 분석하고 보정 식들을 제시했다.

• 한국철도학회논문집
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• 제10권2호
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• pp.231-242
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• 2007

As railroad industry faces the new Renaissance era, effective and efficient maintenance methods for rolling stock operation are required with advanced railroad technology. All kinds of railroad systems such as high-speed long-distance train, metropolitan mass transit and light rail require systematic maintenance technology in order to maintain the safe railroad operation. Simulation models for regular operations of the example maintenance center are developed. In this study, standard maintenance procedures, layout, equipments, and number of workers of Siheung Metropolitan Railroad Maintenance Rolling Stock Depot are considered. The proposed simulation models are developed using simulation package ARENA. After simulation, four types of observations are analyzed. First, the bottleneck operation is identified. Second, the relationship between maintenance center size, number of workers and cycle time is analyzed. Third, the scheduling performances between PERT/CPM and Critical Chain Project Management(CCPM) are compared. Lastly, the simulation results according to worker's working coverage shows expanding the worker's coverage decreases the cycle time and increases throughput per train. However, workers are to be fully trained to do multiple skill work.

• Advances in pediatric surgery
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• 제13권1호
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• pp.1-12
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• 2007

Biliary atresia (BA) is the result of fibrosing destructive inflammatory process affecting intrahepatic and extrahepatic bile ducts, which lead to cirrhosis and portal hypertension. Kasai portoenterostomy has been the standard operative procedure in biliary atresia. Recently, there has been remarkable increase in the survival rate in cases of BA. However, long-term survivors are not clearly evaluated in Korea. To define long-term prognosis factors of patients who underwent surgery for BA, a retrospective study was undertaken of 10 (37 %) patients surviving more than 10 years among 27 patients who underwent one of Kasai procedures between 1981 and 1995. Hepatomegaly was present in 4 and splenomegaly in 7 patients. Serum bilirubin was normalized at 1 year after operation. Aspartate aminotransferase (AST, GOT), Alanine aminotransferase(ALT, GPT) were normalized at 12 years and alkaline phosphatase(ALP) was normalized at 13.5 years. Cholangitis developed mainly within 5 years after operation so close follow up is needed. Life long follow-up is needed because of progressive deterioration of liver function even after 10 years.

• 대한기관식도과학회지
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• 제4권2호
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• pp.219-224
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• 1998

Bilateral vocal cord paralysis can result in severe airway compromise. Over the years a variety of arytenoidectomy procedures have bee described, and one or more of these have been the gold standard for many years. A widely accepted treatment is endoscopic laser total arytenoidectomy. However, vocal results are usually poor. Objective : To evaluate the effect of treatment of endoscopic laser medial partial arytenoidectorny for bilateral vocal cord paralysis Material and Methods : We performed endoscopic medial partial arytenoidceomy with $CO_2$laser for 3 patients with bilateral vocal cord paralysis. The $CO_2$laser is operated with a continuous 7-watt beam in superpulse mode. We compared degree of dyspnea and glottic area of pre-operation with those of post-operation for 3 patients. We analysed aerodynamic study pre-operatively and post-operatively for 1 patient. Results The symptom of dyspnea was improved markedly and the glottic area was widened from 34% to 50% compared with that of pre-operation. The voice quality was slightly decreased. Tracheotomy was not necessary for not-tracheotomized patient and decanulation was possible for tracheotomized patient post-operatively. Cunclusion： The endoscopic laser medial partial arytenoidectomy is a convient and effective method for opening the posterior glottic airway.

• 환경영향평가
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• 제25권6호
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• pp.532-541
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• 2016

국가환경시료은행(NESB)에서는 환경오염물질의 생태계 영향을 모니터링하기 위한 시료로서 8종의 생물시료를 정기적으로 채취하여 초저온(<$-130^{\circ}C$) 저장을 해 오고 있다. 이 중 2 종의 활엽수(느티나무 및 신갈나무 잎)가 중금속 및 잔류성유기오염물질(POPs)과 같은 대기오염물질 모니터링을 위한 환경시료로서 활용되기 위해 채취되고 있다. 한 지역을 대표하기 위해 군락 내 여러 개체에서 시료를 채취하는 과정에서 개체별 차이 및 오염분포 특성에 따른 이질성이 구성 시료의 대표성에 영향을 미치게 되고 따라서 분석을 통한 측정값을 활용한 연구의 신뢰도에 문제를 초래할 수 있다. 따라서 이러한 시료종은 엄격한 표준운영절차(SOP)에 따라 채취됨으로써 대표성을 확보할 수 있고 이를 근거로 오염물질의 지역간, 연도별 비교가 가능하게 된다. 본 연구에서는 표준운영절차(SOP)에 따라 5 지역의 고정구에서 채취된 신갈나무, 느티나무 잎 시료를 대상으로 지역 간 오염물질의 농도차이를 비교하기 위해 주요원소 및 중금속, 그리고 다환방향족탄화수소(Polycyclic aromatic hydrocarbons, PAHs)에 대한 분석을 실시하였다. 그 결과인 측정값을 활용하기에 앞서 이에 대한 신뢰도 수준을 평가하기 위한 방편으로 시료채취단계에서 중복 시료를, 시료분석단계에서 중복분석을 수행하여 분산분석(ANOVA)을 수행하였다. 이로써 시료채취 및 분석의 단계별 불확도를 분리하여 산출한 후 측정불확도로 통합한 결과 측정값의 지역 간 연도별 농도비교에 통계적 신뢰도 수준으로 활용할 수 있었다. 아울러 잎표면 대기침적물질 중 강우에 영향을 받는 중금속 및 PAHs 종류를 파악하기 위해 누적강우량과 오염물질의 축적도간 관계를 분석하였다.