• Radiation Oncology Journal
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• 제35권2호
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• pp.137-143
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• 2017

Purpose: To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Materials and Methods: Data was analyzed on men diagnosed with localized prostate cancer between 2004-2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. Results: There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was $725cGy{\times}5fractions$ (49.6%) followed by $700cGy{\times}5fractions$ (21.3%). Conclusions: Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently $700-725cGy{\times}5fractions$ appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase.

• 한국환경보건학회지
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• 제42권2호
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• pp.92-101
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• 2016

Objectives: Outdoor workers are exposed to thermally stressful work environments. In this study, heat stress indices for harbor workers in summer were calculated to evaluate thermal comfort based on a human heat balance model. These indices are Physiological Subjective Temperature (PST), Dehydration Risk (DhR), and Overheating Risk (OhR) according to respective stage of cargo work in a harbor. In addition, we constructed a forecast system to provide heat stress information. Methods: Thermophysiological indices in this study were calculated using the MENEX model (i.e. the human heat balance model), which used as inputs the meteorological parameters, clothing insulation, and metabolic rate for each stage of cargo work in the harbor of Masan over the course of seven days, including a four-day heat wave. The forecast heat stress information constructed for Masan harbor was based on meteorological data supported by the Dong-Nae Forecast from the KMA (Korea Metrological Administration) and other input parameters. Results: According to higher metabolic rate, thermophysiological indices showed a critical level. In particular, PST was evaluated as reaching the 'Very hot' or 'Hot' level during all seven days, despite the heat occurring over only four. It is important in a regard to consider the work environment conditions (i.e. labor intensity and clothing in harbor). On a webpage, the forecast thermophysiological indices show as infographics to be easily understand. This webpage is comprised of indices for both current conditions and the forecast, with brief guidance. Conclusion: Thermophysiological indices show the risk level to health during a heat wave period. Heat stress information could help to protect the health of harbor workers. Further, this study could extend the applicability of these indices to a variety of outdoor workers in consideration of work environments.

• 한국항만경제학회지
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• 제37권3호
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• pp.105-116
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• 2021

항만부잔교는 조석 간만의 차가 심한 곳에서 조위에 관계없이 선박이 접안할 수 있도록 부유식 함체를 1개 혹은 여러 개 연결하여 부두 기능을 갖도록 한 구조물이다. 국내 항만부잔교는 233개가 설치되어 있고, 30년 이상 경과된 부잔교는 27.5%에 달한다. 30년 이상 경과된 항만부잔교는 잠재적으로 사고의 위험성이 높지만 노후화된 항만부잔교에 대한 명확한 폐기, 매각 등의 처리기준이 없고, 유지점검 및 보수시기 등에 관한 관리규정이 모호한 실정이다. 본 연구에서는 항만별 담당자 인터뷰와 기존 문헌연구를 통해 항만부잔교시설 운영의 문제점과 개선 요인을 분류하여 AHP 모형 설계하였다. AHP 분석결과 상위계층 평가요인의 상대적 중요도는 법제도 개선, 운영관리 개선, 기술적 개선의 순으로 나타났다. 본 연구는 국내 항만부잔교시설 운영 개선을 위한 기초자료로 활용이 가능하다.

• 대한조선학회논문집
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• 제49권1호
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• pp.1-5
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• 2012

Recently, with increasing container ships' volume continuously, the conceptual design "Smart Harbor" of newly logistics processing system has been suggested. It is necessary to estimate resistance and horsepower for the selection of an appropriate propulsor at the initial design stage of Smart Harbor. In this study, CFD and the circulating water channel of the University of Ulsan are employed for estimating the resistance of the Smart Harbor Crane Ship with 1/100 scaled model. Two turbulent models are used. One is realizable k-${\varepsilon}$and the other is Reynolds stress turbulence model. In addition, the effects of the change in y+ and the number of meshes are considered during analysing.

• 한국항해항만학회지
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• 제31권7호
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• pp.579-587
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• 2007

Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

• 한국항해항만학회지
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• 제30권2호
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• pp.125-130
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• 2006

Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.53-58
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• 2006

Today, harbor oscillation problems are the most significant factor to consider when designing harbors serving very large ships. In coastal harbors, large vessels moored in the elastic hawsers are often displaced due to the resonance between long period waves and mooring systems. As a result, cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes extreme. The most significant harbor confronted with harbor oscillation problem in Korea is Pohang New port. Many cases of problems are being reported by the pilot association and the local office of MOMAF (Ministry of Maritime Affairs and Fisheries). However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, the Korean government has already started a new port plan at the mouth of Yeongil Bay without addressing the problems that have occurred in Pohang New port. This study deals with the variation of harbor oscillation due to the construction of a 4.1 km breakwater at the bay mouth including the arrangement of the new berths. Numerical methods used are in fairly standard form from the extended mile slope equation. The obtained numerical results were compared with field measurement from the previous and this will bring a certain level of discussion and consideration of variation to the future port development.

• 한국전산구조공학회논문집
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• 제25권1호
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• pp.27-36
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• 2012

모바일하버는 선박의 대형화로 인하여 항만에 접안 및 정박이 불가능하거나 선박의 접안 대기시간이 길어지는 경우 등 항만의 문제점들을 해결하기 위해 제시된 새로운 개념의 시스템이다. 이 새로운 시스템은 해상에 있는 선박에 다가간 후, 모바일하버에 설치된 크레인을 이용하여 선박에 컨테이너를 직접 상, 하역작업을 하도록 고안되었다. 모바일하버용 크레인은 컨테이너를 이송하는 장치로써 그 중요성이 매우 크다. 본 연구에서는 모바일하버용 크레인의 형태들을 제시하고 각 형태에 따른 구조최적설계를 실시하였다. 불안정한 해상으로부터 발생되는 횡동요 및 종동요와 바람에 의한 풍하중을 최적설계의 하중조건으로 하였다. 또 한국선급 및 각각의 규정들을 최적설계의 제한조건으로 하여 규정을 만족하면서 경량화된 크레인 구조를 최적화하였다.

• Ocean Systems Engineering
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• 제2권3호
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• pp.217-228
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• 2012

As the size of container ships continues to increase, not many existing harbors can host the super-container ship due to its increased draft and the corresponding dredging requires huge budget. In addition, the minimization of waiting and loading/offloading time is the most important factor in harbor competitiveness. In this regard, mobile-harbor concept has been developed in Korea to achieve much improved harbor capacity and efficiency. In developing the concept, one of the most important elements is the operability of crane between two or more floating bodies in side-by-side arrangement. The container ship is to be stationed through a hawser connection to an outside-harbor fixed-pile station with the depth allowing its large draft. The mobile harbors with smart cranes are berthed to the sides of its hull for loading/offloading containers and transportation. For successful operation, the relative motions between the two or more floating bodies with hawser/fender connections have to be within allowable range. Therefore, the reliable prediction of the relative motions of the multiple floating bodies with realistic mooring system is essential to find the best hull particulars, hawser/mooring/fender arrangement, and crane/docking-station design. Time-domain multi-hull-mooring coupled dynamic analysis program is used to assess the hydrodynamic interactions among the multiple floating bodies and the global performance of the system. Both collinear and non-collinear wind-wave-current environments are applied to the system. It is found that the non-collinear case can equally be functional in dynamics view compared to the collinear case but undesirable phenomena associated with vessel responses and hawser tensions can also happen at certain conditions, so more care needs to be taken.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.574-578
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• 2006

Tidal amplification by construction of the sea-dike and sea-walls had been detected not only near Mokpo Harbor but also at Chungkye Bay which is connected with Mokpo Harbor by a narrow channel. This brings about increase of tidal flat area and in particular increase of surge-wave combined runup during storms. The purpose of this study is to examine an efficient operational model that can be used by civil defense agencies for real-time prediction and fast warnings on wind waves and storm surges. Instead of using commercialized wave models such as WAM, SWAN, the wind waves are simulated by using a new concept of wavelength modulation to enhance broader application of the hyperbolic wave model of the mild-slope equation type. Furthermore, The predicting system is composed of easy and economical tools for inputting depth data of complex bathymetry and enormous tidal flats such as Mokpo coastal zone. The method is applied to Chungkye Bay, and possible inundation features at Mokpo Harbor are analyzed.