• Wind and Structures
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• 제19권2호
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• pp.169-184
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• 2014

This paper presents a method of estimation of extreme wind. Assuming the extreme wind follows the Gumbel distribution, it is modeled through fitting an exponential function to the numbers of storms over different thresholds. The comparison between the estimated results with the Improved Method of Independent Storms (IMIS) shows that the proposed method gives reliable estimation of extreme wind. The proposed method also shows its advantage on the insensitiveness of estimated results to the precision of the data. The volume of extreme storms used in the estimation leads to more than 5% differences in the estimated wind speed with 50-year return period. The annual rate of independent storms is not a significant factor to the estimation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2297-2302
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• 2010

The status and effectiveness of Bi-modal Tram is analyzed through the comparison of the transport effectiveness and operation cost between the public transportation systems (bus, light rail transit) considering the vehicle and operation characteristic of new transit system Bi-modal Tram. The standard operation schedule is established in consideration of the vehicle specification and operation characteristic of main public transportation modes, and then the annual average operation cost is estimated depending on the volume, speed, analysis length for respective public transportation mode. Through analyzing the operation cost and distribution characteristic of public transportation modes depending on the transport volume and travel speed, the operational efficiency suitable for the city is derived. It is concluded that the operational efficiency of Bi-modal Tram is superior to that of the bus and light rail transit on the aspect of travel volume and operation speed.

• 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.

• 한국산림과학회지
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• 제96권2호
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.

• 한국산림과학회지
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• 제90권3호
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• pp.331-337
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• 2001

본 연구에서는 PC기반의 Windows운영체제에서 운용될 수 있는 수간석해 프로그램(Stemwin1.0)을 개발하였다. Stemwin1.0에서는 연륜측정기에서 1/100mm 단위로 측정된 l년 단위의 연륜폭 자료를 입력받아 흉고직경 및 단면적, 수고, 재적 등 각종 생장량을 다양한 방법으로 계산할 수 있다. 즉, 수령별 평균 흉고직경 및 단면적은 산술 및 단면적 평균법을 적용해 계산할 수 있으며, 수고생장은 평행선법, 직선연장법, 수고곡선법 등에 의해 다양하게 추정할 수 있다. 재적은 Huber식, Smalian식, Spline식 등을 선택적으로 적용해 추정할 수 있다. 선택된 계산방법에 따라 상가 각 생장인자의 총, 평균 및 연년 생장량 뿐만 아니라 이용재적 및 수고, 형수, 생장률 이용률 등의 생장 관련 정보가 1년 단위로 자동 계산된다. 또한, 1년 단위의 정밀한 간곡선도를 다양한 축척으로 출력할 수 있으며 간곡선식 유도를 위한 통계분석용 자료(단판 높이별 직경)도 제시된다. Stemwin1.0에서는 계산결과를 MS-Excel로 전환할 수 있도록 하여 사용자가 손쉽게 활용할 수 있도록 하였다.

• 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.

• Industrial Engineering and Management Systems
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• 제13권4호
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• pp.432-441
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• 2014

As the business model is receiving considerable attention these days, the ability to collect business model related information has become essential requirement for a company. The annual report is one of the most important external documents which contain crucial information about the company's business model. By investigating business descriptions and their future strategies within the annual report, we can easily analyze a company's business model. However, given the sheer volume of the data, which is usually over a hundred pages, it is not practical to depend only on manual extraction. The purpose of this study is to complement the manual extraction process by using text mining techniques. In this study, the text mining technique is applied in business model concept extraction and business model evolution analysis. By concept, we mean the overview of a company's business model within a specific year, and, by evolution, we mean temporal changes in the business model concept over time. The efficiency and effectiveness of our methodology is illustrated by a case example of three companies in the US video rental industry.

• 한국대기환경학회지
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• 제3권2호
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• pp.11-17
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• 1987

Atmospheric particulate matter (A.P.M.) was collected on quartz fiber filters from March 1985 to February 1986 at Chung-Ang University according to particle size using Andersen high-volume air smapler, and benzo (a) pyrene concentration in these particulates were analyzed by high performance liquid chromatography. The annual arithmetic mean concentration of A.P.M. was 115.50$\mug/m^3$. The annual arithmetic mean concentrations of coarse particles and fine particles in A.P.M. were 52.54$\mum/m^3$ and 62.96$\mum/m^3$ respectively. THe annual arithmetic mean concentration of benzo(a)pyrene in A.P.M. was 1.44$ng/m^3$. THe annual arithmetic mean concentrations of benzo(a)pyrene in coarse particles and fine particles were 0.05 $ng/m^3$ and 1.39 $ng/m^3$ respectively. Thus, the concentration of benzo(a)pyrene showed maldistribution of 96.53% in fine particle. A.P.M. showed wide fluctuation according to the season. The concentration of A.P.M. was lowest in summer and high in spring and winter. Coarse and fine particle concentrations in A.P.M. were highest in spring and winter, respectively. The concentrations of benzo(a)pyrene was highest in winter and lowest in summer. The concentrations of benzo(a)pyrene in fine and coarse particles were highest in winter and spring, respectively.

• 기술사
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• 제42권4호
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• pp.45-50
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• 2009

The modal split structure of the Korea's transportation system has been dominated by road-oriented structure. The shortage of the inftrastructure to accommodate the rapidly increasing travel demand has brought about socio-economic losses such as severe traffic congestion and high logistic costs, and thereby weakened the competitiveness of the country. Highway transportation sector is more vulnerable to energy consumption comparing with railway sector since the highway sector is dependent mostly on fossil fuels for its energy source. In 2006 annual road cogestion costs in Korea reached 24.6 trillion won, with an average annual growth rate of 5.4%. The annual road congestion cost of intercity highways were 9.2 trillion won. As the new cities that recently developed are located far from Seoul area, the boundary of commuting in Seoul metropolitan area is extended. It makes passengers have longer trips with longer travel time, and the congestion problem to be more serious. In this regards, Gyeonggi Provincial Government proposed a deeper underground metropolitan express train system for the greater Metropolitan area. which is named as GTX. Gyeonggi Province suggested 3 key underground lines, based on the outcome of the feasibility study conducted by the Korea Society of Transportation, and submitted to the Ministry of Land Transportation and Maritime Affairs for its review. If the project is approved for construction and completed in 2016, the daily volume of surface traffic bound for Seoul will be reduced substantially and therefore the users will be benefitted for time savings by an annual amount of 2 trilion won every year.

• 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.