• 한국압력기기공학회 논문집
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• 제11권2호
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• pp.68-74
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• 2015

Time domain response analysis for vibro-impact nonlinear behavior of multi-span tube with loose supports was performed using commercial FEA code and user subroutine. Support geometry of multi-span tube with a finite gap is realistically modeled by analytical rigid surface. Model of hydrodynamic force is based on the Qusai-steady model which accounts for the inclined angle of relative flow velocity and time delay between flow force and resulting tube motion. During tube vibration from flow loading, impact and friction at the support location is simulated using commercial FEA code with master slave contact algorithm. Analysis results has reasonable agreement with those of references and test experience. Plan of further refinement of analysis model and future test verification is briefly introduced.

• 한국생산제조학회지
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• 제25권5호
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• pp.313-320
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• 2016

The need for high-strength, multi-axis, and multi-functional machine tools has recently increased because of part complexity and workpiece strength. However, most of the machine tool manufacturers rely on experience for a detailed design because of the shortcomings in the existing design technology. This study uses a topology optimization method to more effectively design a large multi-functional machine tool considering static stiffness. The ram, saddle, and column parts are important structures in a machine tool. Hence, they are selected for the finite element method analysis. Based on this analysis, the optimized internal rib structure for those parts is designed for desirable rigidity and weight. This structure could possibly provide the required design technology for machine tool manufacturers.

• 한국산학기술학회논문지
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• 제14권6호
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• pp.2566-2574
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• 2013

본 연구는 쌀가루를 활용한 조리 경험과 오븐을 사용해 본 경험이 있는 14명의 외식 및 식품 관련 종사자와 전업주부를 대상으로 포커스 그룹 인터뷰를 시행하여 쌀가루 조리가 편리한 가정 외식용 복합오븐 개발에 필요한 자료를 수집하였다. 조사 결과, 대체로 쌀가루의 홍보부족과 다양하지 못한 메뉴, 그리고 상품화된 오븐의 사용법이 복잡하여 자주 사용하지 못하고 있는 것으로 나타났다. 본 연구에서는 분석된 자료를 바탕으로 가정 및 외식업체에서 사용하기 간편한 소형 복합오븐의 외형 디자인, 사용자 경험, 기능적 특성, 색상에 관한 개발안을 제시하였다. 이를 토대로 디자인 출원(30-2012-0016256) 및 최종제품을 실제로 상품화하여 연구의 성과지표를 높였다는데 연구의 의의가 있다.

• 가족자원경영과 정책
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• 제17권2호
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• pp.195-218
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• 2013

The purpose of this study is to offer suggestions to help immigrated youths of multicultural families become successful members of Korean society while preparing to enter schools or becoming involved in social activities. The study examined the following three issues using grounded theory: (1) the characteristics of cultural adaptation for immigrated youths of multi-cultural families; (2) their acculturation processes; and (3) their different patterns of acculturation experience. The process of acculturation involves (1) feeling timid, (2) feeling regretful and angry, (3) looking around and making an attempt, (4) feeling difficulty and feeling left out, (5) accepting reality and seeing Korea in a positive light. The core of acculturation among the immigrated youths of multicultural families is a limited living in an unfamiliar culture. Five acculturation patterns were found in the current study: (1) Someone who is actively striving for future dreams; (2) someone who adjusts himself/herself to circumstances without plans; (3) someone who passively makes an effort; (4) someone who accepts reality to continue education; and (5) someone who temporarily stays for financial reasons.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2177-2193
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• 2018

This paper studies resource allocation schemes for the relay-aided cooperative system consisting of multiple source-destination pairs and decode-forward (DF) relays. Specially, relaying selection, multisubcarrier pairing and assignment, and power allocation are investigated jointly. We consider a combinatorial optimization problem on quality of experience (QoE) and energy consumption based on relay-aided cooperative system. For providing better QoE and lower energy consumption we formulate a multi-objective optimization problem to maximize the total mean opinion score (MOS) value and minimize the total power consumption. To this end, we employ the nondominated sorting genetic algorithm version II (NSGA-II) and obtain sets of Pareto optimal solutions. Specially, two formulas are devised for the optimal solutions of the multi-objective optimization problems with and without a service priority constraint. Moreover, simulation results show that the proposed schemes are superior to the existing ones.

• Journal of Korean Neurosurgical Society
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• 제45권6호
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• pp.378-380
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• 2009

Osteoporotic patients who undergo percutaneous vertebroplasty (PVP) have the risk of a repeated collapse of their adjacent vertebral body due to alteration of load transfer into the adjacent vertebral body. The authors have experienced a rare case of repeated osteoporotic vertebral compression fractures (VCF) resulting in extreme multi-level PVP. A 74-year-old female developed severe back pain after slipping down one month ago. Her X-ray and MR images indicated a T11 VCF. She underwent successful PVP with polymethylmethacrylate (PMMA). Two weeks later, she returned to our hospital due to a similar back pain. Repeated X-ray and MR images showed an adjacent VCF on T12. A retrial of PVP was performed on T12, which provided immediate pain relief. Since then, repeated collapses of the vertebral body occurred 12 times in 13 levels within a 24-month period. Each time the woman was admitted to our hospital, she was diagnosed of newly developed VCFs and underwent repeated PVPs with PMMA, which finally eased back pain. Based on our experience with this patient, repeated multiple PVP is not dangerous because its few and minor complications. Therefore, repeated PVP can serve as an effective treatment modality for extreme-multi level VCFs.

• 한국엔터테인먼트산업학회논문지
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• 제5권2호
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• pp.87-95
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• 2011

최근 다양한 인터랙티브 인터페이스 개발로 인해 체감형 게임 환경에 관심이 모아지고 있다. 따라서 본 논문에서는 증강현실 기술의 하나인 마커인식 인터페이스와 멀티 터치 인터랙션 인터페이스를 이용한 멀티 카드 터치 기반의 인터랙티브 아케이드 시스템을 제안한다. 이를 위해 DI 기반의 인식 알고리즘을 적용하여 카드의 위치, 방향 정보를 인식한다. 또한 사용자의 손 제스처 정보를 트래킹하여 다양한 인터랙션 메타포를 제공한다. 본 시스템은 사용자에게 좀 더 높은 몰입감을 제공하며 새로운 경험을 제공한다. 따라서 제안하는 시스템은 체감형 아케이드 게임기기에 활용될 것이다.

• 한국사회복지학
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• 제67권1호
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• pp.263-288
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• 2015

본 연구는 성인의 대인외상경험과 외상 후 성장의 관계에서 낙관성과 관계의 질의 다중매개효과를 검증하기위해 실시되었다. 이를 위해 30세 이상 60세미만의 성인을 대상으로 임의표집방법에 의해 조사를 실시하였다. 주요 분석방법으로는 구조방정식모델(SEM) 분석을 AMOS프로그램을 사용해 실시하였다. 매개효과 검증을 위해서 Bootstrap 방법을 사용 하였고, 다중매개효과의 간접효과 검증을 위해서는 팬텀변수(Phantom Variable)를 사용해 모형을 변형한 후 분석하였다. 연구결과, 대인외상경험 수준이 높을수록 외상 후 성장도 높게 나타났다. 둘째, 대인외상경험과 외상후 성장 사이에서 낙관성과 관계의 질이 각각 부분매개하는 것으로 나타났다. 셋째, 대인외상경험과 외상 후 성장 사이에서 낙관성과 관계의 질이 이중매개하는 것으로 나타났다. 연구결과를 토대로 실천현장에서의 실천적 전략과 사회복지에의 함의를 제시하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.148-152
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• 2007

In recent days, on account of the cultural development and the improvement of citizen's consciousness level, it is the real situation that the construction of small-scaled Multi-Purpose Hall where various cultural events could be performed, is on increasing. However, since the most of Multi-Purpose Hall had been designed and built up without any consideration on Acoustic Factor, many problems are on occurring thereat. Since those small-scaled Multi-Purpose Hall have been mostly used with the finishing material which contains a high degree of Acoustic Absorption indiscreetly, both diffusion and reflection of sound are not establishing properly, and because thereverberation of sound is very low, in case of musical performance by musical instrument, its sound hears too arid and stiff, there occurs some acoustic defect such as it becomes difficult for music appreciation with sufficient timbre, so that the capability improvement on the matter is urgently requiring situation. Therefore, this Study has tried to seize the satisfaction level about the small-scaled Multi-Purpose Hall after betterment of the acoustic performance by appraise the acoustic condition of the Hall, using Auralization Technique that can experience Virtual Acoustic Field regarding to the small-scaled Multi-Purpose Hall as its object. It is deemed that such research result could be practically used as the useful material which enables to bring a reduction effect of construction cost as well asenhancement of the acoustic performance through its presupposition?control on the acoustic problem when construction or renovation of other similar small-scaled Multi-Purpose Hall in the future.

• 한국정밀공학회지
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• 제20권4호
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• pp.29-38
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• 2003

This paper deals with an automated computer-aided process planning and die design system with which designer can determine operation sequences even after only a little experience in process planning and die design of multi former-bolt products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge fur the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. It can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution and the level of the required forming loads by controlling the forming ratios. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The standardization of die parts for multi former-bolt products requiring a cold forging process is described. The system developed makes it possible to design and manufacture multi former-bolt products more efficiently.