• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.2
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• pp.20-34
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• 2003

The good sea-keeping capability of the SWATH(Small Waterplane Area Twin Hull) ship has been attractive for research or surveillance vessels. Especially, for the naval ships accomplishing the underwater acoustic missions, it is necessary to access and minimize the underwater radiated noise level generated by the ships. Therefore, acoustic signature management and control are very important topics for these vessels. Underwater radiation pattern in the low frequency range is dominated by the tonals from the vibration of onboard machinery. In this work, the radiated noise level generated by the propulsion machine in the submerged hull is predicted using the transfer function technique and the hull transfer function for the submerged hull is determined by analyzing the longitudinal/circumferential stiffened infinitely long cylindrical shell and considering the empirical database of the previous vessels. It is confirmed that the transfer function technique can give useful information for identifying the noise source and estimating its contribution to the total radiatied noise level.

• Journal of Haehwa Medicine
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• v.10 no.1
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• pp.67-78
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• 2001

From the study of acupuncture and external diseases on mammary diseases, the following conclusions are obtained. 1. Point Shanzhong, Shaoze and Rugen are often used for galactostasis in acupuncture. 2. Often used vessels for galactostasis in acupuncture are Stomach Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Liver Meridian and Large Intestine Meridian in order. 3. The direct stimulations are used in external treatment for galactostasis, often accompanied by internal medical treatment, to promote the circulation of Qi and Blood. 4. Point Zuimup, Guangming of Gall bladder Meridian and Zusanli of Stomach Meridian is used for lactation pain in acupuncture. 5. Point Jianjing, Zusanli and Shanzhong are most often used for acuremastitis and breast cancer in acupuncture. 6. Often used vessels for acuremastitis and breast cancer in acupuncture are Stomach Meridian, Gall bladder Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Pericardium Meridian in order. 7. The external treatment used for acuremastitis and breast cancer can be classed into its pathological period. When lactation is interrupted, Kumhwang Powder, Okro Powder, Robongbang, Allii Radix, Pinelliae Rhizoma, garlic moxibustion and Arusaenatus Rgizoma powder are used. When pus is piled up, Chunghwa Extracts, Dioscoreae Rhizoma, Leonuri Herba, Typa Latifolia, Taraxacum platycarpum, Phaseolus angularis, Manchong, Crvi Cornus latex, and Aucklandiae Radix are used. When pus flows down, Salviae Miltiorrhizae Radix Extract, nine-one pellet, Yongboo extract, eight-dampness extract, Tissue-regeneration Powder, Toad-net treatment, Kitten-hair, Hongseung pellet are used. 8. Stomach Meridian, Conception Vessel, Small Intestine Meridian, Gall Bladder Meridian, Bladder Meridian are most often used vessels for mammary diseases. From the conclusions above, It appears that the medical effect could be maximized by further studying and developing of the acupuncture and external treatment for mammary diseases according to the its nature, while accompanying internal medicine appropriately at the same time.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.73-82
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• 2022

Marine fisheries resources face major anthropogenic threat from unregulated fishing activities; thus require precise detection for protection through marine surveillance. Korea developed an efficient land-based small fishing vessel monitoring system using real-time V-Pass data. However, those data directly do not provide information on fishing activities, thus further efforts are necessary to differentiate their activity status. In Korea, especially in Busan, longlining is practiced by many small fishing vessels to catch several types of fishes that need to be identified for proper monitoring. Therefore, in this study we have improved the existing fishing status classification method by applying Hidden Markov Model (HMM) on V-Pass data in order to further classify their fishing status into three groups, viz. non-fishing, longlining and other types of fishing. Data from 206 fishing vessels at Busan on 05 February, 2021 were used for this purpose. Two tiered HMM was applied that first differentiates non-fishing status from the fishing status, and finally classifies that fishing status into longlining and other types of fishing. Data from 193 and 13 ships were used as training and test datasets, respectively. Using this model 90.45% accuracy in classifying into fishing and non-fishing status and 88.23% overall accuracy in classifying all into three types of fishing statuses were achieved. Thus, this method is recommended for monitoring the activities of small fishing vessels equipped with V-Pass, especially for detecting longlining.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.1
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• pp.58-65
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• 2018

The purpose of this study is to develop a Half Nozzle Repair(HNR) process to prevent the leakage from welds on small bore piping in Reactor Coolant System. The Codes & Standards of tempered bead and design requirements of J-Groove welds are reviewed. Automatic machine GTAW welding and machining equipments are developed to perform HNR process. Single pass welding and overlay welding equipments are conducted in order to obtain the optimal temper bead welding process parameters with Alloy 52M filler wire. Coarse grain heat affected zone(CGHAZ) is formed by rapid cooling rate in heat affected zone after welding. Accordingly, a proper temper bead technique is required to reduce CGHAZ in 1-Layer of welds by 2- and 3-Layers. Mock-up tests show that the developed HNR process is possible to meet ASME Code & Standard requirements without any defect.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.3
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• pp.175-185
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• 2023

Many small vessels such as fishing boats operate in the world's oceans; accordingly, interest in these small vessels' exhaust-gas problem is increasing. Research on the application of electric-propulsion technology has been steadily conducted; however, the subject is limited to research ships or leisure boats, while research on application efficiency remains insufficient. This study attempts to apply lithium-battery electric-propulsion technology to small ships. A gross tonnage of 9.77, a representative fishing boat, is to be redesigned as a fully electrified ship. Without changing the main cabin's dimensions and fuel tanks, the ship's propulsion system is redesigned based on a lithium-battery electric-propulsion system. In addition, the redesigned system is compared with the original sample ship's diesel-propulsion system for application-effect analysis. The results indicate that under controlled sailing conditions, the weight and volume of the electric-propulsion system are 9.5 and 10.5 times those of the diesel-propulsion system, respectively. These values indicate that the system cannot meet fishing boats' high endurance requirements. Therefore, under the existing technical conditions, applying the full lithium-battery electric-propulsion system to solve the problem of high emissions from fishing boats shows limited feasibility.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.18 no.2
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• pp.69-76
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• 2022

In order to prepare for a future nuclear market, research for developing floating small modular reactor has been initiated with the aim of differentiating it from large nuclear power plants such as distributed power, heat supply to remote communities and sea water desalination. Depending on the characteristics of the small modular reactor, it is necessary to design a plate and shell heat exchanger that can be manufactured smaller than the U-tube recirculation method. In this study, 12 cases are selected by changing the diameter of the heat plate, the thickness of the device body and the size of the stiffener. Finite element analysis is performed by setting the stress classification lines for the point at which deformation is expected under external pressure conditions for these analysis cases. For the basic design of the plate and shell heat exchanger, the optimal conditions are derived by analyzing the tendency of stress change in the device body and stiffener.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.321-325
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• 2004

Retinopathy of Prematurity (ROP) is a common retinal neovascular disorder of premature infants. It can be characterized by inappropriate and disorganized vessel. This paper present a method for blood vessel detection on infant retinal images. The algorithm is designed to detect the retinal vessels. The proposed method applies a Lapalacian of Gaussian as a step-edge detector based on the second-order directional derivative to identify locations of the edge of vessels with zero crossings. The procedure allows parameters computation in a fixed number of operations independent of kernel size. This method is composed of four steps : grayscale conversion, edge detection based on LOG, noise removal by adaptive Wiener filter & median filter, and Otsu's global thresholding. The algorithm has been tested on twenty infant retinal images. In cooperation with the Digital Imaging Research Centre, Kingston University, London and Department of Opthalmology, Imperial College London who supplied all the images used in this project. The algorithm has done well to detect small thin vessels, which are of interest in clinical practice.

• Journal of Biomedical Engineering Research
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• v.12 no.2
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• pp.99-106
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• 1991

For the automatic detection of pulmonary blood vessels, a new algorithm is proposed using the fact that human recognizes a pattern orderly according to their size. This method simulates the human recognition process by the pyramid images. For the detection of vessels using multilevel image, large and wtde ones are detected from the most compressed level, followed by the detection of small and narrow ones from the less compressed images with FCM(fuzzy c means) clustering algorithm which classifies similar data into a group. As the proposed algorithm detects blood vessels orderly according to their size, there is no need to consider the variation of parameters and the branch points which should be considered in other detection algirithms. In the detection of patterns whose size changes successively like pulmonary blood vessels, this proposed algorithm can be properly applied

• Journal of Ocean Engineering and Technology
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• v.38 no.3
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• pp.124-136
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• 2024

As the number of offshore wind-power installations increases, collision accidents with vessels occur more frequently. This study investigates the risk of collision damage with operating vessels that may occur during the operation of an offshore wind turbine. The floater used in the collision study is a 15 MW UMaine VolturnUS-S (semi-submersible type), and the colliding ships are selected as multi-purpose vessels, service operation vessels, or anchor-handling tug ships based on their operational purpose. Collision analysis is performed using ABAQUS and substantiation is performed via a drop impact test. The collision analyses are conducted by varying the ship velocity, displacement, collision angle, and ship shape. By applying this numerical model, the extent of damage and deformation of the collision area is confirmed. The analysis results show that a vessel with a bulbous bow can cause flooding, depending on the collision conditions. For damage caused by collision, various collision angles must be considered based on the internal stiffener arrangement. Additionally, the floater can be flooded with relatively small collision energy when the colliding vessel has a bulbous bow.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.91-95
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• 1984

This paper describes to analyze regression relation between the ratio mean draft to freeboard and KM/dm, KB/dm and GM/B, respectively with the 43 Korean fishing vessels (7 Danish seiners; 1l Stowers; 14 Poler and liners; 6 Trawlers; 5 Purse seiners) and the 1 Cargo boat in order to obtain the stability factors of the Korean fishing vessels conveniently. The obtained results are as follows; 1. The stability factors by fishing vessels have a tendency to the larger f/dm, the larger KM/dm and KG/dm, and KB/dm and GM/B are constant. 2. It is found out that M and G differ from the kinds of the fishing vessels because KM/dm is the largest in poler and liners and KG/dm in Danish seiner, respectively. 3. It is confirmed that the stability factors of the fishing vessels which the inclining experiment carry out the wholly in the light and the full loaded condition are the same as the inclining experiment uniformly.