• Journal of Ocean Engineering and Technology
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• v.26 no.2
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• pp.79-84
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• 2012

This study aimed to analyze the nonlinear buckling of ring-stiffened circular cylinders under uniform external pressure, e.g. hydrostatic pressure, considering material nonlinearity and initial imperfection. In the present study, we analyzed the collapse pressure of pressure vessels using ANSYS Workbench, which is a framework of finite element methods. First, linear buckling analysis is performed to find collapse modes of the model. Second, scaling the first mode shape with small factor, geometric model is pre-deformed. And then, by analyzing the nonlinear buckling of the pre-deformed shape, the collapse pressure is estimated. To verify the validity of the analyses, we compared the results with Ross' experimental results. Finally, we applied it to ring-stiffened circular cylindrical shell of the pressure hull of a small submarine.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.366-372
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• 2019

This study performed a numerical analysis of a 3D unsteady viscous flow in order to investigate ship motion responses running through regular waves of the platform supply vessel. The feasibility of numerical analysis was tested under the three regular wave conditions of the KRISO container ship (KCS) suggested at the 2010 Gothenburg CFD Workshop. The resulting resistance coefficient, heave motion, and pitch angle were compared with the model test of the harmonic analysis. Also, the ship motion response characteristics of the platform supply vessel were performed using the proven method of the KRISO container ship (KCS). The ship motions including the resistance coefficient, heave motion, and pitch angle according to the time series were investigated via harmonic analysis under regular waves condition of ${\lambda}/LPP=1.87$ and $H_S=0.078m$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.341-346
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• 2023

This study aimed to suggest an alternative income generation (AIG) for local artisanal fisheries communities in the southern coastal area of Bangladesh, which is vulnerable to climate change. To analyze the problems of local artisanal fisheries caused by climate change, field surveys and in-depth interviews with fishermen and government officials were conducted. Livelihood risk factor (LRF) in the marine fishing sector included reduction of fishing days and fish production and damage to fishing vessels and fishing gear due to cyclone and sea-level rise. LRF in the aquaculture sector included cultured fish escape, reduction of aquaculture production, and water pollution due to Monsoon flood. A common challenge for two sectors was high interest rate on commercial loans. Small-scale tank aquaculture is recommended as AIG for securing income of artisanal fisheries communities. In the early stages of dissemination of small-scale tank aquaculture technology, it is necessary to prevent fishermen from struggling to repay high-interest rate loans through technology transfer and facility support by official development assistance. The aquaculture training center, along with the technical education, will also contribute toward expansion of local distribution network and marketing support to establish a value chain for local artisanal fisheries communities.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.114-115
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• 2023

Research on eco-friendly ships is being actively conducted due to the strengthening of environmental regulations in the shipping sector by the International Maritime Organization (IMO). However, most studies are on large ships, and research on small ships is insufficient. Since most fishermen operate small boats, research on eco-friendly fuel vessels is necessary. This study performed resistance performance analysis, model tests, and POW tests to develop a hybrid electric propulsion ship, and compared and verified the CFD and model test results.

• The Korean Journal of Nuclear Medicine
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• v.20 no.2
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• pp.61-71
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• 1986

An iodized oil such as Ethiodol or Lipiodol was selectively retained in the tumor vessels of the large hepatomas as well as in the small daughter hepatomas for long periods following the intra-arterial hepatic injection of such contrast material. The specific aim of the study is to deliver a high internal radiation dose to hepatocellular carcinoma (HCC) in an attempt to control the disease. We were able to replace a small fraction of the stable iodine (I-127) of the 37% iodine in Lipiodol by the $I^{-131}$ with 100% exchange efficiency. $I^{-131}$ labeled Lipiodol was injected through the super-selected tumor feeding artery under superselection or into the proper hepatic arterial level of patients who have malignant hepatomas confirmed by aspiration cytology serum AFP and various imaging modalities. Clinical traial was performed on 43 cases during recent 6 months and follow-up observation was carried out. No severe complications or other adverse reactions were encountered until nowdays. $I^{-131}-Lipiodol$ was stable in vivo and no significant activity was noted in the thyroid, stomach, blood and urine after the injection. Only small fraction of radioisotope activity was noticed in the both side of lungs. Tumor to normal liver radio was very high. Therefore, $I^{-131}-Lipiodol$ (or P-32-Lipiodol) will be effective delivering high internal radiation dose to the tumor while delivering small radiation doses to normal tissues. Labeling, tumor dose calculation and preliminary findings will be presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.210-211
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• 2023

To reduce maritime accidents and improve safety for domestic ships, the government has developed and is operating the Korean e-Navigation Service. The ship collision and grounding monitoring service and the route planning service were developed based on the experience of captains and navigators who navigated large ships. However, in Korea, small ships account for a large portion of the users of these services, so there are various difficulties and additional requirements for applying services based on large ships to small ships. To improve this, a data science-based algorithm model using maritime digital traffic information is being developed for small ships, and it is important to evaluate the performance of the developed model and compare its accuracy with existing services. In this study, we propose a performance evaluation method for the developed algorithm model and study how to compare and evaluate its accuracy with existing e-navigation services.

• Journal of Korean Foot and Ankle Society
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• v.28 no.1
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• pp.27-30
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• 2024

Several types of soft tissue masses occur in the lower extremities. A mass associated with blood vessels is often difficult to diagnose. A 15-year-old male patient visited the author's hospital with discomfort and edema in his right calf that had persisted for six months. A physical examination showed no palpable mass other than mild edema. Three masses were found during the ultrasound scan along the small saphenous vein. The masses had a cyst-like appearance and were filled with thrombus. In duplex ultrasound, vascular reflux was represented inside the masses. During surgery, it was suspected that vascular deformation occurred in the small saphenous vein, and simple ligation and resection treatments were performed. The patient was finally diagnosed with venous aneurysms accompanied by thrombosis based on the histology tests. The symptoms disappeared after surgery, and there were no recurrences or unusual findings at the follow-up one year later. Venous aneurysms occurring in the superficial veins of the lower extremities are rarely reported, but treatment and diagnosis are important. This paper reports a case of an aneurysm on the small saphenous vein.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.182-188
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• 2012

The hull form design technique for high speed power boat based on the parametric design method is presented in this paper. While the design methods of conventional vessels that are currently in use have been well developed in various aspects from existing database. However, an easy and simple design program for high speed power boats needs to be provided for the relatively small boat builders who are in lack of experience and skilled manpower. This paper presents a parametric design technique which is aimed to provide an easier creation of a new model by inputting several parameters, such as angles and lengths, which correlate with hydrodynamics characteristic for high speed boats. The paper also introduces the prototype program developed to design power boat with parametric design technique.

• Journal of the Korean Society for Nondestructive Testing
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• v.5 no.2
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• pp.22-33
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• 1986

The application and development of on-line monitoring technology of AE to surveillance of crack propagation will contribute to the structural integrity of reactor pressure vessel and piping system. This research has been performed in order to obtain the evaluation technology for source location of AE and the analysis for the AE signal of the welded specimen. AE is detected by 4-channels AE system during pressurization in small pressure vessels. The cracking of artificial defects can be accurately located and categorized in real time. The welded specimens have more events rate and higher amplitude than the weldless less specimens, and the events rate have a peak around the yield point and just before the failure under tensile test.

• Journal of Plant Biology
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• v.13 no.4
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• pp.13-22
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• 1970

The rice variety, Kwanok, was reared in the water, land and salt seed beds and transplanted to the reclaimed soil area having an average of 0.48% salt content (0.67% at the end of April). The plant height of land bel seedlings at transplanting stage was short but the dry-weight/plant-height ratio was large and the rooting ability was vigorous remarkably after transplantation in the salty area. The central cylinder, vessels, sclerenchyma, endodermis and other mechanical tissues of the root of land bed seedlings were well developed while the size of cortical cell layers were small. The cytoplasm of the cortical parenchyma at the root tips seemed to be most abundant in the land bed seedlings. The formation of the aerial cavity in the cortex of primary root was rapid and it seemed that the developmental mechanism of the aerial cavity in the rice plant roots was related to the development of the lateral roots.