• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.5
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• pp.629-643
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• 2018

For a sailing ship, the frictional resistance exerted on the hull of ship is due to viscous effect of the fluid flow, which is proportional to the wetted area of the hull and moving speed of ship. This resistance can be reduced through air bubble lubrication to the hull. The traditional way of introducing air to the wetted hull consumes extra energy to retain stability of air layer or bubbles. It leads to lower reduction rate of the net frictional resistance. In the present paper, a novel air bubble lubrication technique proposed by Kumagai et al. (2014), the Winged Air Induction Pipe (WAIP) device with opening hole on the upper surface of the hydrofoil is numerically investigated. This device is able to naturally introduce air to be sandwiched between the wetted hull and water. Propulsion system efficiency can be therefore increased by employing the WAIP device to reduce frictional drag. In order to maximize the device performance and explore the underlying physics, parametric study is carried out numerically. Effects of submerged depth of the hydrofoil and properties of the opening holes on the upper surface of the hydrofoil are investigated. The results show that more holes are favourable to reduce frictional drag. 62.85% can be achieved by applying 4 number of holes.

• Journal of Korean Dental Science
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• v.12 no.2
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• pp.66-72
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• 2019

Osteochondroma is a bone tumor with cartilaginous growth potential that generally appears near the growth plate of long bones in areas such as hip, knee, and shoulder joints, related to the nature of endochondral ossification and it is known a common benign bone tumor. However, it has been very rare in craniofacial region possibly because craniofacial bone is largely formed by intramembranous ossification. Moreover, reports on the solitary type of osteochondroma in mandibular condyle has been extremely rare. Osteochondroma in mandibular condylar may show various symptoms similar to general temporomandibular joint disorders (TMDs), such as pain in the condylar area during mouth opening, internal derangement, facial asymmetry or posterior open bite. Therefore, it can be disregarded for a long time period without any adequate treatment. Surgical excision has been the treatment option for the solitary osteochondroma with very low recurrence rate reportedly. In this case report, a rare case of solitary osteochondroma developed in unilateral mandibular condyle is presented with emphasis on differential diagnosis with general TMDs.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.1
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• pp.45-50
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• 1997

It is not clearly known how surface defects or inclusions of a medium carbon steel affect a fatigue strength. In this study, we used SM35C specimens with spheroidized cementite structure to eliminate dependence of micro structure of fatigue crack. The investigation was carried out by behavior of crack closure at non-propagation crack and effect of the fatigue limit according to the artificial defects size. Experimental findings are obtained as follows : (1) Fatigue crack initiation point of medium carbon steel with spheroidized cementite structure is at the surface defects. (2) Non-propagating crack length of smooth specimen is equal to the critical size of defect. (3) Considering the opening and closure behavior of fatigue crack, the defect shape results in various crack opening displacement, while it does not affects the fatigue limit level of medium carbon steel with spheroidized cementite structure. (4) The critical length of the non-propagation crack of smooth specimen is the same as critical size of defect in transient area which determines threshold condition in steel with spheroidized cementite structure.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.4
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• pp.53-60
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• 2013

We propose a method for improving detection speed of small target detection system using SAD algorithm. First, the proposed method deletes clutters using a median filter. Next, it does closing and opening operation using various size of structure elements, and extracts candidate pixels for a target with subtraction operation between the results of closing and opening operation. It finally detects a small target using a gaussian distance function from the candidate pixels. To improve detection speed, it detects a target performing SAD algorithm only for the predicted target areas for next every 7 frames. The proposed method not only enables a real time process because it considers only predicted area but also shows detecting rate of 97%.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.3
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• pp.45-54
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• 2011

The purpose of this study is to help understanding of east-west culture fusion in fashion since 2000 years, to play a guideline's role in the development on fashion designs study. The methods of this study are academic literatures as well as practical study through case studies about actual works. Tendency of east-west culture fusion in fashion since 2000 years is shape and performance, pattern, accessary. Shape and performance are reinterpreted through east folk fashion transforming on west fashion, pattern shows traditional pattern of each nations, but letters of typical of each nations appears for new pattern which expresses nation identification. Accessary is in the harmony with east -west fashion culture like that without transform. Aesthetic value of east-west culture fusion in fashion since 2000 years is summerised opening, co-ownership, and amusement. First, opening is positiveness of acception and acknowledgment for other. Second, co-ownership turns towards humanism, and proves participating in globalism and really global village. Third, amusement is to express freedom, and to reveal privately emotion concealing in public area.

• Journal of architectural history
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• v.21 no.2
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• pp.53-74
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• 2012

This study aims to overview and review the infiltration of Japanese Buddhism and it's influences on the construction and architectural characteristics of Japanese Buddhist temple from the opening of ports to Independence Day of Korea. Infiltration of Japanese Buddhism had been sustained during 70 years from the foundation of Higashi Hongan-ji Temple(東本願寺) in Pusan, by Shinshu Otani School(眞宗 大谷派) which was one of Japanese Buddhism, to Independence Day of Korea. This study is to be promoted on the following subjects ; 1) the circumstance around the infiltration of Japanese Buddhism 2) Buddhism policy of Japanese Governor and infiltration on Korean Buddhism 3) increasing trend, distribution and construction of Japanese Buddhist temples near downtown areas 4) for the conclusion, case research on Bondang, Gori, and open space and analysis on the architecture style of Japanese Buddhist temples. Accordingly, Korean Buddhism had been subordinated to Japanese Buddhism, and the management system and memorial service of Korean Buddhism had to be affected by Japanese Buddhism. This study is considered meaningful for the elementary research to examine the aspects of Japanese style on Korean Buddhist architecture at that time.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.1061-1071
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• 2001

The present study investigated design parameters of shunt valves and anti-siphon device used to treat patients with hydrocephalus. The shunt valve controls drainage of cerebrospinal fluid (CSF) through passive deflection of a thin and small diaphragm. The anti-siphon device(ASD) is optionally connected to the valve to prevent overdrainage when the patients are in the standing position. The major design parameters influencing pressure-flow characteristics of the shunt valve were analyzed using ANSYS structural program. Experiments were performed on the commercially available valves and showed good agreements with the computer simulation. The results of the study indicated that predeflection of the shunt valve diaphragm is an important design parameter to determine the opening pressure of the valve. The predeflection was found to depend on the diaphragm tip height and could be adjusted by the diaphragm thickness and its elastic modulus. The major design parameters of the ASD were found to be the clearance (gap height) between the thin diaphragm and the flow orifice. Besides the gap height, the opening pressure of the ASD could be adjusted by the diaphragm thickness, its elastic modulus, area ratio of the diaphragm to the flow orifice. Based on the numerical simulation which considered the increased subcutaneous pressure introduced by the tissue capsule pressure on the implanted shunt valve system, optimum design parameters were proposed for the ASD.

• Explosives and Blasting
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• v.26 no.1
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• pp.1-5
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• 2008

In this study, the structural behavior accorded by pre-weakening before demolishing a cylindrical structure was investigated to ensure structural stability using 3 dimensional applied element method (3D AEM). An opening angle of crushed area for the pre-weakening was changed to examine the displacement behavior of the cylindrical structure. This study shows that the crushing range for pre-weakness must be below 40% to void the collapse of the cylindrical silo structure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.3
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• pp.176-181
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• 2009

Synovial chondromatosis is a rare, benign, monoarticular arthropathy that is characterized by the development of highly cellular, metaplastic cartilaginous nodules in the synovial membrane. It commonly affects larger joints such as the knee, elbow, wrist, shoulder, and hip. Synovial chondromatosis of the temporomandibular joint(TMJ) is rare. Moreover, the temporal involvement of synovial chondromatosis without connection with joint is greatly rare. A 44-year-old women had experienced pain of the right TMJ area and limitation of mouth opening. MRI and CT revealed multiple calcified loose bodies and widening in right upper joint space of TMJ and osteolytic lesion in right temporal bone. Treatment consisted of removal of multiple loose bodies, resection of the osteolytic lesion through the preauricular approach. She was diagnosed with primary transitional synovial chondromatosis of TMJ with involvement of temporal bone. In spite of remaining of the loose bodies, pain and mouth opening improved and there have been no recurrence of signs and symptoms for 5 years follow up.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.8
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• pp.562-570
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• 2011

In this research, an experimental study is performed to investigate the effects of system operating variables on the cooling and heating characteristics of heat pump system using geothermal heat source and carbon dioxide as a refrigerant. System variables analyzed include compressor frequency, electronic expansion valve opening, refrigerant charge, secondary fluid temperature and flow rate. Results show that optimum refrigerant charge and electronic expansion valve opening position exist at the maximum point of COP curve, and both cooling and heating capacity increase but COPs decrease with the increase of compressor frequency. The change of a secondary fluid temperature leads to variation of overheat area and enthalpy difference in the evaporator and gas cooler. which again results in considerable variations of cooling and heating capacity and COP. In the case of effects of secondary water fluid flow rate, both cooling capacity and COP increase with the increase of secondary flow in evaporator or gas cooler, whereas heating capacity and COP decrease with the increase of flow rate in gas cooler.