• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.390-397
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• 2012

According to sailing condition, an exciting force for luminairie of naval vessels was measured and analyzed. A naval combat service support boat and P${\bigcirc}{\bigcirc}$(patrol killer guided missile) were selected as a target naval vessel. Due to their small size and fast speed, they received excessive vibration than other bigger naval vessels like destroyer. The vibration of luminairie was measured on their cruising and maximum speed. This could analyze exciting force for luminairie of naval vessels. Using this analyzed data, the validity of military standard for naval vessel was verified.

• Archives of Craniofacial Surgery
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• v.24 no.3
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• pp.129-132
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• 2023

Scalp defects necessitate diverse approaches for successful reconstruction, taking into account factors such as defect size, surrounding tissue, and recipient vessel quality. This case report presents a challenging scenario involving a temporal scalp defect where ipsilateral recipient vessels were unavailable. The defect was effectively reconstructed utilizing a transposition flap and a latissimus dorsi free flap, which was anastomosed to the contralateral recipient vessels. Our report underscores the successful reconstruction of a scalp defect in the absence of ipsilateral recipient vessels, emphasizing the importance of employing appropriate surgical interventions without necessitating vessel grafts.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1524-1536
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• 2017

During the fabrication process of reactor vessel head penetration (RVHP), the grain size of the tube material can be changed by hot or cold work and the inner side of the tube can also be shrunk due to welding outside of the tube. Several nonregular time-of-flight diffraction (TOFD) signals were found because of deformed grains. In this paper, an investigation of nonregular TOFD indications acquired from RVHP tubes using experiments and computer simulation was performed in order to identify and distinguish TOFD signals by coarse grains from those by Primary Water Stress Corrosion Crack (PWSCC). For proper understanding of the nonregular TOFD indications, microstructural analysis of the RVHP tubes and prediction of signals scattered from the grains using Finite Element Method (FEM) simulation were performed. Prediction of ultrasonic signals from the various sizes of side drilled holes to find equivalent flaws, determination of the size of the nonregular TOFD indications from the coarse grains, and experimental investigation of TOFD signals from coarse grain and shrinkage geometry to identify PWSCC signals were performed. From the computer simulation and experimental investigation results, it was possible to obtain the nonregular TOFD indications from the coarse grains in the alloy 690 penetration tube of RVHP; these nonregular indications may be classified as PWSCC. By comparing the computer simulation and experimental results, we were able to confirm a clear difference between the coarse grain signal and the PWSCC signal.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.79-86
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• 2002

Anatomical characteristics of Mulpurenamu (Korean ash, Praxmus rhynchopbylla), Deulmaenamu (Manshurican ash, Fraxinus mandsburica) and Sheamulpure (Sieboldiana ash, Fraxinus sieboldiana) grown in Korea were examined by an optical microscopy and an image analysis. Some characteristics such as boundary of annual rings, shape and size of vessel elements, arrangement of axial parenchyma cells in cross section, and cell volumetric composition showed significant differences between the sample species. In radial variation of elements, fiber length and vessel size increased from the pith for about 10 to 15 years and then reached a more or less constant. The results of this study can be used for identification of wood and indices of wood quality in Fraxinus spp.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.38-44
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• 2006

The majority of both small and large-scale experiments on gas explosion have been carried out in the explosion instruments with cylindrical tubes of a high length/diameter ratio and vessels of a high height/length ratio, focusing on investigating the interaction between propagating flame and obstacles inside the tubes or vessels. The results revealed that there is a strong interaction between the propagating flame and turbulence formed after the flame passes the obstacle. However this paper focuses on analyzing the pressure impact or profile outside the vent in vented gas explosion in a partially confined chamber by performing gas explosion experiments in a reduced-scale experimental assembly properly constructed. This study has considered eight different cases in gas explosion based on variation of three kinds of parameters such as height of vessel, shape of the vent and vent size, and reveals that the large vessel with big size circle vent is more danger to the target than others because the overpressure is spread out faraway horizontally and vertically.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2071-2078
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• 2024

The precipitation of solutes is a major cause of irradiation hardening and embrittlement limiting the service life of reactor pressure vessel (RPV) steels. Impurities play a significant role in the formation of precipitation in RPV materials. In this study, the effects of carbon on cluster formation and irradiation hardening were investigated in an RPV alloy Fe-1.35Mn-0.75Ni using C and Fe ions irradiation at 290 ℃. Nanoindentation results showed that C ion irradiation led to less hardening below 1.0 dpa, with hardening continuing to increase gradually at higher doses, while it was saturated under Fe ion irradiation. Atom probe tomography revealed a broad size distribution of Ni-Mn clusters under Fe ion irradiation, contrasting a narrower size distribution of small Ni-Mn clusters under C ion irradiation. Further analysis indicated the influence of carbon on the cluster formation, with solute-precipitated defects dominating under C ion irradiation but interstitial clusters dominating under Fe ion irradiation. Simulations suggested that carbon significantly affected solute nucleation, with defect clusters displaying smaller size and higher density as carbon concentration increased. The higher hardening at doses above 1.0 dpa was attributed to a substantial increase in the number density of defect clusters when carbon was present in the matrix.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.832-838
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• 2021

Recently, reports of marine accidents of small fishing vessels less than 10 tons have been increasing. In this study, the characteristics of the motion response in regular waves were analyzed using computations for these ships. Small vessels less than 10 tons are classified by size and used for marine accident investigations. Therefore, the motion response analysis was performed on three small fishing vessels of different sizes. In the case of the head sea, it was confirmed that as the speed of the vessel increased in the long wavelength region, the motion responses of heave and pitch became large. The motion response of the smallest 3-ton fishing vessel was greater than that of the other sizes of fishing vessels. The maximum value of the roll motion shifted to the long wavelength region as the speed gradually increased in the bow sea, regardless of the size of the ship. In all the three small fishing vessels, it was found that the roll motion was the greatest at 15 knots, the highest speed in both bow and beam seas. When sailing in the head sea and bow sea conditions, lowering the speed is one of the effective approaches to reduce the effects of the vertical and lateral plane motions. The roll motion caused by the beam wave showed a tendency to increase rapidly only at a specific wavelength regardless of the speed and the size of the vessel. It was confirmed that the roll motion was significantly reduced with forward speed in the stern wave compared to the bow wave. As there is a specific region where the maximum value of the hull motion response appears depending on the size and speed of the ship, an operation method that can minimize the effect of this motion should be considered and implemented.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.421-429
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• 2005

Traditionally, determination of the optimal containership size is the most important factor for competitiveness of shipping companies in the shipping market. Under this environment, many shipping companies and researchers have studied about it. The objective of this research is to determine the optimal containership size using a total shipping cost in the main trunk lines. Total shipping cost is calculated at the ground of capital costs, vessel operation costs, voyage costs, port charges and miscellaneous costs for 'Europe-Far East', 'Far East-North America' and 'Europe-Far East-North America' services. Analysis results showed that the 6,500TEU containership is an optimal size on the 'Europe-Far East' and 'Europe-Far East-North America' services. And the 8,200TEU containership is an optimal size on the 'Far East-North America' service. Moreover, if the larger containerships over 8,200TEU class start operation afterward, it would be less competitive in the analyzed 3services.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.137-142
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• 2010

Purpose: Tumor ablation and traumatic intractable ulceration of the plantar surface of the foot results in skin and soft tissue defects of the weight-bearing sole. Simple skin grafting is not sufficient for reconstruction of the weight-bearing areas. Instead, the island medial plantar flap (instep flap) and distally-based island medial plantar flap was used for proper reconstruction of the weight bearing area. However, there are some disadvantages. In particular, an island medial plantar flap has a short pedicle limiting the mobility of the flap and the distally-based island medial plantar flap is based on a very small vessel. We investigated whether good results could be obtained using a reverse island medial plantar flap based on the lateral plantar vessel as a solution to the above limitations. Methods: Three patients with malignant melanoma were cared for in our tertiary hospital. The tumors involved the lateral forefoot, the postero-lateral heel, and the medial forefoot area. We designed and harvested the flap from the medial plantar area, dissected the lateral and medial plantar artery and vena comitans, and clamped and cut the vessel 1 cm proximal to the branch from the posterior tibial artery and vena comitans. The medial plantar nerve fascicles of these flaps anastomosed to the sural nerve, the 5th interdigital nerve, and the 1st interdigital nerve of each lesion. The donor sites were covered with skin grafting. Results: The mean age of the 3 subjects was 64.7 years (range, 57 - 70 years). Histologically, all cases were lentiginous malignant melanomas. The average size of the lesion was $5.3\;cm^2$. The average size of the flap was $33.1\;cm^2$. The flap color and circulation were intact during the early postoperative period. There was no evidence of flap necrosis, hematomas or infection. All patients had a normal gait after the surgery. Sensory return progressively improved. Conclusion: Use of an island medial plantar flap based on the lateral plantar vessel to the variable weight-bearing sole is a simple but useful procedure for the reconstruction of any difficult lesion of the weight-bearing sole.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.810-819
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• 2020

Recently, the demand for liquefied gas has been increasing for various reasons, including environmental problems, and as a result, transportation of liquefied gas through a ship is increasing, and several terminals are also being constructed to accommodate it. The size of the terminal to be constructed shall follow the result if the target ship is clearly determined. Otherwise, the size of the vessel that the terminal intends to accept shall be determined, and then, the dimensions of the vessel given in the regulations or standards shall be used. In this regard, it was found that the main dimensions of the proposed vessels are substantially different from those actually operating and the standard for large-sized vessels has not been established in the process of determining the size of the target vessel by using the "Port and Fishing Port Design Standards" and commentary(2017), which recently is most commonly used as port design criteria in order to construct the liquefied gas terminal. Because of these problems, a revision of the standard for the major dimensions of liquefied gas carriers was proposed through an analysis of the current status of ships in service, as there could be many differences between interested parties in determining the size of the target ships and terminals and evaluating the safety of terminals. It is expected that the proposed revision will be used as a more appropriate and realistic criterion for determining the size of ships and terminals in the future and will prevent unnecessary terminal construction costs.