• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2018년도 추계학술대회
• /
• pp.248-255
• /
• 2018

Deep-sea fishing vessel No. 501 Oryong was fully flooded through the openings and was sunk down to the bottom of sea due to the very rough sea weather on the way of evasion after fishing operation in the Bearing Sea with many crews dead and/or missed. In this study, calculation of ship stability was carried out using KST-SHIP(ship calculation system of KST), considering the effect of flow fluid and fish catch arrangement according to the progress of its sinking accident, and damage stability was analyzed. For this study, intact stability calculation of its accident ship under the full load departure condition and its calculation result were verified by comparing with each other, and intact stability according to displacement from the departure of accident ship just before the accident was calculated and analyzed. Damage stability was calculated according to the progress during sinking accident and also analyzed.

• 한국항해학회지
• /
• 제21권3호
• /
• pp.83-90
• /
• 1997

Damage stability is generally very important as a part of rescue technique of damaged ship and also in connection with the requirements of MARPOL73/78[2]. Damage stability calculation program has been developed and suggest, which can be used on an onboard computer for any operating drafts. The program is based on lost buoyancy method for calculation of final drafts, and also based on added mass method for calculation of residual righting arm. The numerical method suggested by Hamamoto-Kim[6] is adopted for calculation of intact righting arm(GZ). The model experiments on damage stability are also carried out in a small tank with tanker model 2.385 meters long. The experimental results are compared with the calculations by the suggested method.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제8권5호
• /
• pp.487-495
• /
• 2016

In the offshore project such as semi-submersible FPU and FPSO, the free fall type life boat called TEMPSC (Totally Enclosed Motor Propelled Survival Craft) has been installed for the use of an emergency evacuation of POB (People on Board) from the topside platform. For the design of life boat arrangement for semi-submersible FPU in the initial design stage, the drop height and launch angle are required fulfill with the limitation of classification society rule and Company requirement, including type of approval as applicable when intact and damage condition of the platform. In this paper, we have been performed the numerical studies to find proper arrangement for the life boats consider drop height in various environmental conditions such as wave, wind and current. In the calculations, the contributions from static and low frequency (LF) motions are considered from the hydrodynamic and mooring analysis as well as damage angle from the intact and damage stability analysis. Also, Air-gap calculation at the life boat positions has been carried out to check the effect on the life boat arrangement. The air-gap assessment is based on the extreme air-gap method includes the effect of 1st order wave frequency (WF) motions, 2nd order low frequency roll/pitch motion, static trim/heel and set down.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.148-151
• /
• 2009

In these days it is important to secure the life and stability of the structure such as aircrafts, automobiles and building. So the structural health monitoring is needed. In conventional lamb wave techniques, damage is identified by comparing the measured data (baseline signals) and the current data. But this method can lead to high false signal in the intact condition of the structure due to environmental conditions of the structure. As a solution to resolve it, the structural health monitoring method which doesn't use baseline signals is necessary. Damaged structure has unusual elastic wave. This paper proposed a PC(pitch-catch) method which doesn't use baseline signal. New baseline signals can get from detection signal. Damage signals based on new baseline signals. This paper made an image includes damage information by applying damage-signals to beamformming.

• 대한조선학회논문집
• /
• 제49권1호
• /
• pp.52-59
• /
• 2012

Among many factors to be considered for higher safety level requirements, the hull stability in intact and damaged conditions in seaways is of utmost importance. Since the assessment of a damaged ship is complicated due to the highly non-linear behavior, it is widely acknowledged that computational fluid dynamics (CFD) methods are one of the most feasible approaches. Although many research activities are being reported on the damaged ship stability recently, most of them are not designed for validation of CFD studies. In this study, well-designed model tests were performed to build a CFD validation database, which is essential in developing better CFD methods for the damage stability assessment. The geometry of the damaged compartment and test conditions were determined based on preliminary CFD simulations. Free roll decay tests in calm water with both intact and damaged ships were performed and the roll motion characteristics were compared. The damaged ship showed a larger roll damping coefficient and more rapid decrease of roll amplitude than the intact ship. The primary reason of these efforts can be explained by the movement of the flooded water.

• 해양환경안전학회지
• /
• 제27권6호
• /
• pp.856-866
• /
• 2021

대기오염물질 감축에 대한 국제적인 인식이 높아짐에 따라 친환경 선박에 대한 수요가 증가하고 있어 각국에서 전기추진선박 개발을 활발하게 수행하고 있다. 현재 전기추진선박에 대해서는 주로 전기추진시스템 및 전동기 연구를 주로 수행하고 있으며, 선박 관점에서 전기추진시스템 및 배터리의 탑재를 고려한 국내 연안 차도선 개념설계 연구는 수행된 바가 없다. 본 연구에서는 배터리 차량 기반의 이동식 전원공급시스템을 주전원으로 하는 순수전기추진차도선의 개념설계 과정에서의 주요 고려사항에 대하여 검토하였다. 100척 이상의 국내 연안차도선의 제원을 분석하여, 요구사항 만족을 위한 선박의 주요제원 선정과 이동식 배터리 차량 탑재를 고려한 비손상, 손상 복원성능 검토를 수행하였고, 개념설계 과정에서 발생하는 문제의 원인분석을 통해 해결방안을 모색하였다.

• Journal of Veterinary Science
• /
• 제25권1호
• /
• pp.2.1-2.14
• /
• 2024

Background: Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery. Objective: To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy. Methods: Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3-C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/polymethylmethacrylate after testing in Group A). Results: All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3-C7 compared with intact spines (p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4-C6, but only group B showed significance (p = 0.005, and 0.027). Conclusion: Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability.

• 대한조선학회논문집
• /
• 제37권1호
• /
• pp.50-59
• /
• 2000

본 연구는 손상된 선박의 최종 평형 상태에서의 동적 안정성에 관한 내용을 담고 있다. 먼저 1자유도 횡동요 운동방정식에 침입수의 영향과 횡풍 횡파의 영향을 적절히 고려하여 손상선박의 횡동요 응답을 구하였으며, 신뢰성공학적 수법을 이용하여 손상선박의 전복확률의 계산법을 정립하였다. 연구결과 해상상태, 운항상태 그리고 손상상태에 따른 동적 안정성을 확률론적으로 평가할 수 있었다.

• 해양환경안전학회지
• /
• 제25권4호
• /
• pp.413-422
• /
• 2019

해양사고는 항상 인적/물적 피해를 동반한다. 이러한 해양사고가 발생하였을 때 선박의 관리급 해기사가 정확한 지식을 바탕으로 비상 상황에 적절히 대응 한다면 이러한 인적/물적 피해는 최소화 할 수 있을 것이다. 본 연구에서는 해양사고 사례분석을 바탕으로 해양사고 발생 시 부족했던 해기능력 식별, 국제협약에서 요구하는 비상대응 능력을 비교, 선사가 보유하고 있는 다양한 비상대응 매뉴얼 분석 및 설문을 통해 해기사의 비상대응능력 향상을 위한 개선 사항을 제안하였다. 주요 해양사고사례를 통해서 많은 관리급 항해사가 손상복원력, 비손상복원력에 대한 지식의 부재를 식별하였고, 국제협약에서 요구하는 비상대응 해기능력의 경우 일부 축소해서 제공되고 있다는 것을 확인할 수 있었다. 더불어 선사의 비상대응 매뉴얼은 대체로 잘 갖추어져 있으나 실제 비상시 활용 측면에서는 한계가 있다는 것을 식별하였다. 이러한 분석을 바탕으로 선원 및 선사 관계자를 대상으로 설문을 시행하여 국제협약에서 요구하는 비상대응 해기교육의 확대, 시뮬레이터를 활용한 비상상황에 대한 간접경험 기회제공 확대 및 비상 시 효과적이고 효율적인 대응을 위한 지침 또는 매뉴얼의 개발 등을 제안하였다.

• Archives of Reconstructive Microsurgery
• /
• 제7권2호
• /
• pp.88-94
• /
• 1998

Free vascularized fibular transplantation is one of the most useful living bone reconstructive procedure in microsurgical field. Concerning about donor site morbidity, the donor has minor problems of ankle stability and muscle power weakness and transient peroneal nerve symptoms. That problems can be minimized with longitudinal splitted osteotomy on the donor fibula if the bone defect in recipient site is not so large. Half splitted fibula with peroneal arterial pedicle which contains nutrient artery and periosteal vessels, grafted bone can survive with those vascular supplies. Authors underwent five cases of half splitted free vascularized fibular transplantation from 1985. There were no evidence of devascularization in all cases, we can minimized donor morbidity with leaving half fibula intact on donor site. The problem of that technique is technically demanding in longitudinal splitting of bone without damage to peroneal nutrient vessels and periosteal soft tissues which attached to the bone. Authors can propose longitudinal half fibular transplantation is one of modification in free vascularized bone transplantation that minimize donor defect.