• Journal of Chest Surgery
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• 제49권sup1호
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• pp.20-27
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• 2016

Background: This study analyzed the association between the volume of heart surgeries and treatment outcomes for hospitals in the last five years. Methods: Hospitals that perform heart surgeries were chosen throughout Korea as subjects using from the Health Insurance Review and Assessment Service. The treatment outcome of the heart surgeries was defined as the mortality within 30 postoperative days, while the annual volume of the surgeries was categorized. Logistic regression was used as the statistical analysis method, and the impacts of the variables on the heart surgery treatment outcomes were then analyzed. Results: The chance of death of patients who received surgery in a hospital that performed 50 or more surgeries annually was noticeably lower than patients receiving operations from hospitals that performed fewer than 50 surgeries annually, indicating that the chance of death decreases as the annual volume of heart surgeries in the hospital increases. In particular, the mortality rate in hospitals that performed more than 200 surgeries annually was less than half of that in hospitals that performed 49 or fewer surgeries annually. Conclusion: These results indicate that accumulation of a certain level of heart surgery experience is critical in improving or maintaining the quality of heart surgeries. In order to improve the treatment outcomes of small hospitals, a support policy must be implemented that allows for cooperation with experienced professionals.

• Tuberculosis and Respiratory Diseases
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• 제71권5호
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• pp.341-348
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• 2011

Background: The aim of this study was to investigate annual changes in pulmonary function in workers who were exposed to inorganic dust. Methods: The subjects were 2,922 male patients who had been diagnosed with pneumoconiosis more than twice during 6 years from 2005 to 2010. Results: Of the 2,922 cases, forced vital capacity (FVC) decreased by 54 mL in 1 year. In contrast, the annual change of forced expiratory volume in one second ($FEV_1$) decreased by 56 mL. Conclusion: This is the first study that has investigated the annual change in pulmonary function in workers exposed to inorganic dust. The results will help estimate the pulmonary condition of patients who are unable to perform a pulmonary function test due to age or a disorder.

• Journal of Preventive Medicine and Public Health
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• 제56권2호
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• pp.145-153
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• 2023

Objectives: Although it is difficult to define the quality of stroke care, acute ischemic stroke (AIS) patients with moderate-to-severe neurological deficits may benefit from thrombectomy-capable hospitals (TCHs) that have a stroke unit, stroke specialists, and a substantial endovascular thrombectomy (EVT) case volume. Methods: From national audit data collected between 2013 and 2016, potential EVT candidates arriving within 24 hours with a baseline National Institutes of Health Stroke Scale score ≥6 were identified. Hospitals were classified as TCHs (≥15 EVT case/y, stroke unit, and stroke specialists), primary stroke hospitals (PSHs) without EVT (PSHs-without-EVT, 0 case/y), and PSHs-with-EVT. Thirty-day and 1-year case-fatality rates (CFRs) were analyzed using random intercept multilevel logistic regression. Results: Out of 35 004 AIS patients, 7954 (22.7%) EVT candidates were included in this study. The average 30-day CFR was 16.3% in PSHs-without-EVT, 14.8% in PSHs-with-EVT, and 11.0% in TCHs. The average 1-year CFR was 37.5% in PSHs-without-EVT, 31.3% in PSHs-with-EVT, and 26.2% in TCHs. In TCHs, a significant reduction was not found in the 30-day CFR (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.76 to 1.12), but was found in the 1-year CFR (OR, 0.84; 95% CI, 0.73 to 0.96). Conclusions: The 1-year CFR was significantly reduced when EVT candidates were treated at TCHs. TCHs are not defined based solely on the number of EVTs, but also based on the presence of a stroke unit and stroke specialists. This supports the need for TCH certification in Korea and suggests that annual EVT case volume could be used to qualify TCHs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1913-1926
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• 2007

Number of highway lanes and level of service are based on the 30th, 60th or 100th highest hour volume of the target year. On the other hand, railroad design volume is generally expressed in average annual daily traffic (AADT). This procedure ignores attributes of railroad demand's concentration on peak days and hours. Actual data analysis represents railroad's peaking characteristics very similar to those of highways. Therefore it is necessary to set a procedure in selecting design volume for railroad planning. This study presents a concept and the calculating procedure for railroad design hourly volume to analyze effect of railroad investment.

• 한국항만학회지
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• 제5권2호
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• pp.19-37
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• 1991

This work aims to : establish a model of the container physical distribution system of Pusan port comprising 4 sub-systems of a navigational system, on-dock cargo handling/transfer/storage system, off-dock CY system and an in-land transport system : examine the system regarding the cargo handling capability of the port and analyse the cost of the physical distribution system. The overall findings are as follows : Firstly in the navigational system, average tonnage of the ships visiting the Busan container terminal was 33,055 GRT in 1990. The distribution of the arrival intervals of the ships' arriving at BCTOC was exponential distribution of $Y=e^{-x/5.52}$ with 95% confidence, whereas that of the ships service time was Erlangian distribution(K=4) with 95% confidence, Ships' arrival and service pattern at the terminal, therefore, was Poisson Input Erlangian Service, and ships' average waiting times was 28.55 hours In this case 8berths were required for the arriving ships to wait less than one hour. Secondly an annual container through put that can be handled by the 9cranes at the terminal was found to be 683,000 TEU in case ships waiting time is one hour and 806,000 TEU in case ships waiting is 2 hours in-port transfer capability was 913,000 TEU when berth occupancy rate(9) was 0.5. This means that there was heavy congestion in the port when considering the fact that a total amount of 1,300,000 TEU was handled in the terminal in 1990. Thirdly when the cost of port congestion was not considered optimum cargo volume to be handled by a ship at a time was 235.7 VAN. When the ships' waiting time was set at 1 hour, optimum annual cargo handling capacity at the terminal was calculated to be 386,070 VAN(609,990 TEU), whereas when the ships' waiting time was set at 2 hours, it was calculated to be 467,738 VAN(739,027 TEU). Fourthly, when the cost of port congestion was considered optimum cargo volume to be handled by a ship at a time was 314.5 VAN. When the ships' waiting time was set at I hour optimum annual cargo handling capacity at the terminal was calculated to be 388.416(613.697 TEU), whereas when the ships' waiting time was set 2 hours, it was calculated to be 462,381 VAN(730,562 TEU).

• 한국산림과학회지
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• 제110권4호
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• pp.648-657
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• 2021

본 연구는 국가산림자원조사를 활용하여 임상별 및 주요 수종별 재적생장량을 추정하고, 연평균생장량(MAI)과 연년생장량(CAI) 등을 도출하여 벌기령을 제시하고자 수행하였다. 재적생장 추정을 위하여 Chapman-Richards 모델을 적용하였다. 도출된 임상별 재적추정식에서는 침엽수림이 가장 높은 생장을 하는 것으로 나타났다. 주요 수종별 추정식은 침엽수종(3종) 중에서는 일본잎갈나무가, 그리고 활엽수종(3종)에서는 굴참나무가 가장 높은 생장이 예측되었다. 그리고 이들 추정식은 적합도지수가 일본잎갈나무 0.32, 굴참나무가 0.21 등으로 대체적으로 낮게 나타났다. 그러나 재적 추정식의 적용 가능성을 알 수 있는 잔차도 분석에 있어서는, 일부 30년 이상의 임령에서 추정식의 추정치가 과소 추정되는 경향을 보였으나, 대부분 0을 중심으로 잔차가 고르게 분포하고 있었다. 따라서 이들 식이 우리나라 현실림의 수종들에 대한 재적을 추정할 수 있을 것으로 판단된다. 추정된 재적을 이용하여 연평균생장량을 계산한 결과, 침엽수림 중 중부지방 소나무 34년, 일본잎갈나무 35년, 리기다소나무 31년일 때 MAI가 최대시기에 도달하는 것으로 나타났다. 그리고 활엽수림에 있어서는 굴참나무 32년, 상수리나무 30년, 신갈나무 29년일 때가 최대시기임을 알 수 있었다. 또한 MAI와 CAI를 계산하여, 이들이 만나는 지점을 재적수확 최대 벌기령으로 결정하였다. 그 결과는 현재 산림청이 제시한 기준 벌기령과 큰 차이를 보이지 않아 정책자료로 활용이 가능할 것으로 판단된다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2004년도 추계학술대회 논문집
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• pp.367-371
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• 2004

The purpose of this research is furnishing of basic material for acoustic planning hereafter, after understanding the acoustic merits and demerits through measuring and analyzing on room acoustic of small performance hall. As the result of the measurement, those physical evaluation indexes such as SPL, RT, EDT, $D_{50}$, $C_{80}$, RASTI have being kept the satisfiable acoustic condition for the service of performance hall. Therefore, as small performance hall is regarded as equipped with sufficient volume of sound, reverberatory feeling and diffusive feeling, it judges as an excellent performance place, also it is considered that it could be utilized as a useful material when design so similar performance hall, hereafter.

• 한국항공운항학회지
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• 제27권1호
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• pp.20-25
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• 2019

To prepare for the ever-increasing demand for air transport, airport operators should be well aware of the timing of the saturation of the facility and increase the capacity of the airport through extension or extension. The capacity of an airport is determined by the smallest value of the facilities that make up the airport, but it is generally customary to determine the capacity of the costly and time-consuming runway as a whole for the airport. For analyzing the capacity of the runway capacity, the study used the most accurate microscopic air traffic simulation, Simmod-PRO, to analyze the saturation time of three runways currently in Incheon International Airport's operation, and calculate the appropriate time for operation of the 4th runway. The study also calculate the relocation of Airport's high-speed exit taxiway for analyzing the increasing of capacity.

• 디지털콘텐츠학회 논문지
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• 제18권2호
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• pp.257-266
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• 2017

최근에, 분야별로 다양한 도서가 출판되면서 인터넷이나 오프라인 서점에서 구매 선택폭이 넓어진 상황이다. 그러나 오프라인 서점의 경우 책의 손상을 방지하기 위한 비닐포장 현상이 나타나고 있다. 그 결과 책 내용 확인이 어려워 구매결정에 영향을 주게 되는 요인이 되고 있다. 이러한 요인은 연평균 독서량 감소 현상으로 연결된다. 따라서 본 논문에서는 온라인 및 오프라인 서점의 문제점으로 인한 책 판매 감소 현상을 개선하는 마커(Marker)기술 및 AR을 이용한 도서 정보 알림 서비스 "아이 뷰" 어플리케이션을 제안하고자 한다.

• 한국항해항만학회지
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• 제42권6호
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• pp.529-538
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• 2018

항만산업은 수출입 중심인 우리나라의 경제구조에서 중요한 국가기간산업이라 할 수 있다. 특히 국내 컨테이너 물동량의 75%를 처리하는 부산항은 지속적으로 글로벌 선사 물동량 유치를 위해 정기선 항로 서비스를 확대하는 노력 등 컨테이너 정기선 항로에 대한 중요도가 높아질 것으로 예상된다. 본 연구는 사회연결망 분석을 활용하여 2012년부터 2016년까지 부산항을 기항하는 컨테이너 정기선 항로 패턴 분석을 통해 세계 주요항만과의 중심성을 파악하여 부산항과 연결되어 있는 항만 네트워크의 구조적인 특성을 파악하였다. 부산항 컨테이너 정기선 항로 네트워크상에 연결정도 중심성, 근접중심성, 매개중심성이 높은 항만은 싱가포르항으로 분석되었으며, 실제 연도별 부산항 주요 국가 항만별 처리물동량 순위와 부산항 컨테이너 정기선 항로 네트워크 중심성 분석 결과 간 순위 비교는 서로 상이한 것으로 나타났다. 이를 통해 부산항 처리 물동량의 높은 비율을 차지하고 있는 중국 동부항만이 부산항 컨테이너 정기선 네트워크상에서 보았을 때 부산항의 허브항으로 보기 어렵다는 점을 확인하였다. 또한 부산항 컨테이너 정기선 서비스 항로 수는 증가하더라도 해당 항로에 투입되는 선박이 중소형으로 한정되어 있거나 네트워크상 부산항이 싱가포르항 기항을 위한 피더항(Feeder Port)의 성격을 띄고 있는 것으로 추정된다.