• 한국해양공학회지
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• 제14권4호
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• pp.9-16
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• 2000

This paper deals with the numerical and experimental study on the characteristics of the flow around a sunken vessel. Numerical simulation of the two dimensional steady flow on the midship section are carried out by the CFD code which is developed by using finite volume method and which includes the standard $textsc{k}$-$\varepsilon$ model with standard wall function. A experimental study is also carried out for the 1/100 scale model in circulating water channel. A velocity fields around the ship are measuremed by using particle image velocimetry technique. And the fluid forces acting on the ship hull by uniform current are measured by two axis load cell. The computed and measured velocity fields on the midship section are compared with each other in the view point of velocity dstribution and reattachement length, which shows good agreement in quality. The drag force on the vessel also showed the same tendency in both computational and experimental results. However, the quantitative disagreements are shown due to the three dimensional effect of the experiment. The result are used to determine the functional efficiency and stability of the vessel as a artificial reef.

• 대한기계학회논문집B
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• 제33권1호
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• pp.17-27
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• 2009

Water jet impingement cooling is used to remove heat from high-temperature surfaces such as hot steel plates in the steel manufacturing process (thermo-mechanical cooling process; TMCP). In those processes, uniform cooling is the most critical factor to ensure high strength steel and good quality. In this study, experiments are performed to measure the heat transfer coefficient together with the inverse heat conduction problem (IHCP) analysis for a plate cooled by planar water jet. In the inverse heat transfer analysis, spatial and temporal variations of heat transfer coefficient, with no information regarding its functional form, are determined by employing the conjugate gradient method with an adjoint problem. To estimate the two dimensional distribution of heat transfer coefficient and heat flux for planar waterjet cooling, eight thermo-couple are installed inside the plate. The results show that heat transfer coefficient is approximately uniform in the span-wise direction in the early stage of cooling. In the later stage where the forced-convection effect is important, the heat transfer coefficient becomes larger in the edge region. The surface temperature vs. heat flux characteristics are also investigated for the entire boiling regimes. In addition, the heat transfer rate for the two different plate geometries are compared at the same Reynolds number.

• 동아시아식생활학회지
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• 제19권6호
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• pp.1032-1038
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• 2009

This study describes the production of functional Ssukgaen Dduk though the addition of yam and mugwort to Goami 2, a healthy diet and diabetes. In this study, the rice is soaked for many hours and the particle size distribution of the rice was determined as a function of the water-soaking time. The produce Ssukgaen Dduk was repeated after the addition of varying concentration of yam. Non-glutinous rice was soaked for 4, 8, 12 hours and the Goami 2 rice was soaked for 4, 8, 12, 16, 20 hours and ground to a powder and passed through a 18~30 mesh sieve to determine the particle size distribution of the rice as a function of water-soaking time. Using this approach, optimal soaking time for Dduk was found to be 4 hours for non-glutinous rice(pass rate of 30 mesh: 58.29%) and 12 hours for Goami 2(pass rate of 30 mesh: 87.88%). When Ssukgaen Dduk made with Goami 2 rice powder only and those made with varying amounts of yam(10%, 20%, 30%, and 40%) were subjected to the sensory test, the control group(non-glutinous rice Ssukgaen Dduk) had the highest preference in general(3.73). Out of Ssukgaen Dduk containing yam, the S4 group, which contained 30% yam, had the highest preference(2.87) In addition the S4 group also had the highest extent of soft, and delicacy of texture general preference of S5, 40% the lowest(2.37), S1 only Goami 2 the hardness(112.59), as 91.46 lower (83.85) yam increased, the less hard the texture Ssukgaen Dduk. In conclusion Ssukgaen Dduk though the addition of mugwort and yam to the Goami 2 rice, it would be better to add 30% yam to 70% Goami 2 rice powder mixed with mugwort.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.531-554
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• 2006

Oral implants must fulfill certain criteria arising from special demands of function, which include biocompatibility, adequate mechanical strength, optimum soft and hard tissue integration, and transmission of functional forces to bone within physiological limits. And one of the critical elements influencing the long-term uncompromise functioning of oral implants is load distribution at the implant- bone interface, Factors that affect the load transfer at the bone-implant interface include the type of loading, material properties of the implant and prosthesis, implant geometry, surface structure, quality and quantity of the surrounding bone, and nature of the bone-implant interface. To understand the biomechanical behavior of dental implants, validation of stress and strain measurements is required. The finite element analysis (FEA) has been applied to the dental implant field to predict stress distribution patterns in the implant-bone interface by comparison of various implant designs. This method offers the advantage of solving complex structural problems by dividing them into smaller and simpler interrelated sections by using mathematical techniques. The purpose of this study was to evaluate the stresses induced around the implants in bone using FEA, A 3D FEA computer software (SOLIDWORKS 2004, DASSO SYSTEM, France) was used for the analysis of clinical simulations. Two types (external and internal) of implants of 4.1 mm diameter, 12.0 mm length were buried in 4 types of bone modeled. Vertical and oblique forces of lOON were applied on the center of the abutment, and the values of von Mises equivalent stress at the implant-bone interface were computed. The results showed that von Mises stresses at the marginal. bone were higher under oblique load than under vertical load, and the stresses were higher at the lingual marginal bone than at the buccal marginal bone under oblique load. Under vertical and oblique load, the stress in type I, II, III bone was found to be the highest at the marginal bone and the lowest at the bone around apical portions of implant. Higher stresses occurred at the top of the crestal region and lower stresses occurred near the tip of the implant with greater thickness of the cortical shell while high stresses surrounded the fixture apex for type N. The stresses in the crestal region were higher in Model 2 than in Model 1, the stresses near the tip of the implant were higher in Model 1 than Model 2, and Model 2 showed more effective stress distribution than Model.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제23권3호
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• pp.171-176
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• 2017

최근, 효율적인 위성자료처리시스템의 개발을 위해 고성능 컴퓨팅, 클라우스 서비스, 데브옵스 방법론 등의 정보기술(information technology; IT)을 활용하는 연구가 활발히 진행되고 있다. 해양의 장단기 변화를 관측하여 해양재해 재난 예측 및 어장환경 관리를 지원하기 위해 정지궤도해양관측위성-II(Geostationary Ocean Color Imager II; GOCI-II)이 2019년 3월 발사될 예정이며, 자료 수신/처리/저장/배포를 위한 지상시스템(GOCI-II Ground Segment; G2GS)이 해양위성센터에서 설계되고 있다. G2GS는 자료수신(data acquisition subsystem; DAS), 자료보정(data correction subsystem; DCS), 정밀보정(precision correction subsystem; PCS), 자료처리(ocean data processing subsystem; ODPS), 자료관리(data management subsystem; DMS), 운영및품질관리(operation & quality management subsystem ; OQMS) 등 6개의 서브시스템으로 구성되어 있다. G2GS를 이용하여 GOCI-II로부터 생산된 해양 분석 자료를 유관기관 및 일반 사용자에게 실시간으로 제공할 수 있을 것이라 기대하고 있다.

• 한국생활과학회지
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• 제23권3호
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• pp.545-556
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• 2014

The most rapidly growing manufacturing could be cosmetics industries due to this phenomenon. In this study, the cosmetic distribution structure not to mention Korea, Asia's largest market, China and Japan are based on references. Purpose of study is to provide a basis for marketing strategy through the research process and results. Korea cosmetics market has been exerting a tremendous power of LG Household & Health and Amore Pacific as a major company. Cosmetics industry is rapidly booming around the mid-priced brand through internet shopping, TV shopping, and road shops. Cosmetics preferences were analyzed targeted at tourists by distributing questionnaire to 1500 in road shop and Myeong-dong from September 14 to October 13, 2013. The answers for the questions of the most awareness cosmetic brands in Korea are appeared in order of Laneige, Innisfree, The Face Shop. The satisfaction of the use of Korea cosmetic are 61.85% and the reasons are that in a variety of color cosmetics are 32.58%, the reaction of around that you look prettier are 29.34%. Therefore purchasing products are 49.14% of the color cosmetics and 24.93% of the functional products. Within the result of the survey, although the quality versus the price for the Korean cosmetic brands has been competitive advantage over yet from the advertising of Korea wave stars, the foreign purchasers have been willing to buy the color cosmetics and high-end performance products being the research and development of the continuously higher quality of the performance if the preceding even if being more expensive purchase price.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.453-458
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• 2016

머신비전은 고속화된 자동화 생산 시스템의 품질 검사 방법으로 널리 활용되어 왔다. 본 연구에서는 멀티카메라를 사용하여 PC와 PLC 간 제어를 통해 용접부위의 치수를 실시간으로 측정하여 검사하는 머신비전 시스템을 개발하였다. 제안한 검사시스템은 맞대기 용접부위의 길이와 폭을 측정하여 용접부의 치수 균일성을 검사하도록 설계하였다. 광학계 및 물류는 병렬제어를 위해 PC와 PLC 간 TCP/IP 멀티쓰레딩 통신기법을 적용하였다. 금속재료의 반사 특성을 고려하여 용접비드의 형태나 용접시 발생하는 그을음에도 균일하게 검사부위의 영상획득이 가능한 동축조명계를 적용하였고, 검사 알고리즘은 OpenCV 라이브러리를 사용하여 용접치수검사에 맞게 개발하였다. 제작한 시스템을 실제 전자부품의 용접 자동화 라인에 설치하여 시스템의 작동오류 및 검사 성능을 검증한 결과, 요구되는 기능 및 검사 성능을 모두 성공적으로 수행하였다.

• 품질경영학회지
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• 제49권3호
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• pp.299-312
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• 2021

Purpose: We provide a condition-based maintenance policy where a surrogate variable is used for monitoring system performance. We constructed a risk function by taking into account the risk and losses accompanied with erroneous decisions. Methods: Assuming a unique degradation process for the performance variable and its specific relationship with the surrogate variable, the maintenance policy is determined. A risk function is developed on the basis of producer's and consumer's risks accompanied with each decision. With a strategic safety factor considered, the optimal threshold value for the surrogate variable is determined based on the risk function. Results: The condition-based maintenance is analyzed from the point of risk. With an assumed safety consideration, the optimal threshold value of the surrogate variable is provided for taking a maintenance action. The optimal solution cannot be obtained in a closed form. An illustrative numerical example and solution is provided with a source code of R program. Conclusion: The study can be applied to situation where a sensor signal is issued if the system performance begins to degrade gradually and reaches eventually its functional failure. The study can be extended to the case where two or more performance variables are connected to a same surrogate variable. Also estimation of the distribution parameters and risk coefficients should be further studied.

• Archives of Reconstructive Microsurgery
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• 제5권1호
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• pp.35-45
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• 1996

After transplantation of groin free flap was sucessed by the Daniel and Taylor in 1973, the reconstruction of plastic surgery was extensive and universal due to rapidly developement of anatomic study of the donor site and technique of microvascular surgery. The free tissue transfers is possible to be early activity and rehabilitation by one stage operation. It currently available allow transfer of specific tissue quality as bone, muscle, nerve to achieve a functional and cosmetic result as well as the most favorable secondary defect. But free flaps require critical, skillful technique and lengthy operating time. Also it has disadvantage of donor site morbity at the large tissue transfer. Authors were transferred with 107 cases in 103 patients from May 1987 to June 1996, and then we analysed free tissue transfer to acquire more increased sucess rate, satisfactory functional and cosmetic results. The sexual distribution was male prominent in 79 cases(76.7%), female in 24(23.3%) and age was variable distribution from 3 to 76 years old. The cause of defects was most prevalent in trauma of traffic and industrial accident in 51 cases(49%). The common recipient site were lower extremities in 47 cases(43.9%), upper extremities in 28 cases(26.5%), head and neck in 25 cases(23.4%), and trunk in 7 cases(6.5%). The type of transfer were free skin flaps in 46 cases(43%), free muscle or musculocutaneous flaps in 31 cases(29%), free vasculized or osteocutaneous flaps in 10 cases(9.3%), and specilized free flaps in 20 cases(18.7%). The anastomosis of artery was end to end anastomosis in 94 cases(87.9%), end to side anastomosis in 13 cases(12.1%) and all vein was end to end anastomosis. The number of anastomosed vessels were one artery one vein in 62 cases(57.9%), one artery two vein in 45 cases(42.1%) and vein graft was performed only one case. The postoperative mornitoring were used with temperature, color of flap, capillary refilling time, ultrasonogram, bone scan, doppler, and endoscopy. The reexploration was performed in 9 cases(8.4%), and then flap was loss in 3 cases(2.8%). Accordingly overall success rate was 97.2%. The postoperative complication was early vascular occlusion, hematoma, partial necrosis and late bulkiness, scarring, color dismatch etc. Therefore, free tissue transfer is the preferred method of treatment, even through conventional local and distant flaps are available.

• 한국식품저장유통학회지
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• 제21권5호
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• pp.636-645
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• 2014

마 분말 0.5, 1.0과 2.0%를 첨가한 프랑크푸르터 소시지를 제조하여 진공포장한 후 $10^{\circ}C$에서 6주간 저장하며 품질 특성의 변화를 조사하였다. 일반성분은 마 첨가량이 높아질수록 수분, 조단백질 함량은 감소하였고, 조지방과 회분의 함량은 증가하는 경향을 보였으나 마 첨가량 자체가 낮았던 관계로 그 차이는 미미한 편이었다. 마 첨가량 차이에 의한 수분활성도 값은 저장 3주 후 부터는 유의적 차이가 없었다. pH는 저장 후기로 갈수록 감소하는 경향을 보였다. TBA 값은 저장기간이 길어짐에 따라 증가 하였는데 마분말의 첨가량이 많을수록 천천히 증가하였다. VBN 값은 저장기간이 연장될수록 모든 처리구에서 증가하는 경향이 나타났는데, 마 분말의 첨가량이 많을수록 더 크게 증가하였다. 마 첨가 수준이 높아짐에 따라 $L^*$ 값과 $a^*$ 값은 감소하고, $b^*$ 값은 증가되는 경향을 보였다. 기계적 경도 측정치는 마 첨가량이 높아질수록 유의적으로 감소하였다. 관능학적 품질 평가에 따르면 T3는 3주, 그리고 C, T1, T2는 4주까지 상품성이 유지되는 것으로 판단되었다. 결론적으로 마 분말은 1.0%까지 프랑크푸르터 소시지에 첨가하여도 물리화학적 품질 및 저장성에 큰 영향을 주지 않는 것으로 판단되었다.