• Tribology and Lubricants
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• 제30권2호
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• pp.116-123
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• 2014

The objective of this study is to model and simulate the nonlinear lubrication performance of the sliding part between the piston and cylinder wall in a hydrostatic swash-plate-type axial piston pump. A numerical algorithm is developed that facilitates simultaneous calculation of the rotating body motion and fluid film pressure to observe the fluid film geometry and power loss. It is assumed that solid asperity contact, so-called mixed lubrication in this study, invariably occurs in the swash-plate-type axial piston pump, which produces a higher lateral moment on the pistons than other types of hydrostatic machines. Two comparative mixed lubrication models, rigid and elastic, are used to determine the reaction force and sliding friction. The rigid model does not allow any elastic deformation in the partial lubrication area. The patch shapes, reactive forces, and virtual local elastic deformation in the partial lubrication area are obtained in the elastic contact model using a simple Hertz contact theory. The calculation results show that a higher reaction force and friction loss are obtained in the rigid model, indicating that solid deformation is a significant factor on the lubrication characteristics of the reciprocating piston part.

• 한국콘텐츠학회논문지
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• 제11권5호
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• pp.25-31
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• 2011

본 논문은 건축자재들을 컴포넌트로 구성하고 컴포넌트들을 패턴으로 조립하여 패턴 단위로 건축설계가 효율적으로 이루어질 수 있도록 하는 가상건축 구축방안을 제안한다. 조립방식으로 만들어진 건축물을 변경시키고자 할 때 변경될 부분을 선택하면 이에 따른 패턴이 지원되며 여기에 필요한 자재 관련 컴포넌트 및 패턴의 정보 분석을 통하여 설계자에게 재건축에 필요한 정보를 제공해 주도록 한다. 스틸하우스 공법을 이용하여 조립기능은 벽체, 방, 창문, 출입문, 지붕 등으로 구성하였고, 이에 따른 스틸하우스 공법을 활용한 자재자동추출 방법을 기술하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권5호
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• pp.353-357
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• 2020

Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.

• 한국주거학회논문집
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• 제22권3호
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• pp.93-100
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• 2011

The objective of this study is to provide basic objective data which can be utilized as an adjustment criterion for the alleviation of the limit on the number of floors of buildings by quantitatively evaluates the effect of the alleviation of the limit on the number of floors of buildings in apartment complexes on thermal environment of apartment complexes using data obtained from apartments in a class 2 general residential area. In this study, we carried out a thermal environment analysis utilizing the simulation of a virtual object area. The result is summarized as follows: The result of analyzing the entire surface temperature showed an equal decrease of surface temperature due to shadow in all scenarios and high floors showed a tendency of low surface temperature during daytime as the rate of shadow the high floors increase. This influences not only the surface temperature but also HIP and is judged to greatly contribute to the alleviation of the heat island effect. Also, the reason why HIP at high floors shows high values before sunrise and after sunset is thought to be because the concrete wall of the building maintains a high temperature during nighttime by absorbing and storing sunlight during daytime instead of reflecting it since it has low reflectance.

• 제어로봇시스템학회논문지
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• 제17권5호
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• pp.471-478
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• 2011

This UGV (Unmanned Ground Vehicle) is not only widely used in various practical applications but is also currently being researched in many disciplines. In particular, obstacle avoidance is considered one of the most important technologies in the navigation of an unmanned vehicle. In this paper, we introduce a simple algorithm for path planning in order to reach a destination while avoiding a polygonal-shaped static obstacle. To effectively avoid such an obstacle, a path planned near the obstacle is much shorter than a path planned far from the obstacle, on the condition that both paths guarantee that the robot will not collide with the obstacle. So, to generate a path near the obstacle, we have developed an algorithm that combines an edge detection method and a limit-cycle navigation method. The edge detection method, based on Hough Transform and IR sensors, finds an obstacle's edge, and the limit-cycle navigation method generates a path that is smooth enough to reach a detected obstacle's edge. And we proposed novel algorithm to solve local minima using the virtual wall in the local vision. Finally, we verify performances of the proposed algorithm through simulations and experiments.

• 대한영상의학회지
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• 제82권6호
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• pp.1441-1476
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• 2021

기관-기관지분지는 폐와 전신에 산소 공급을 위한 공기의 통로이며, 다양한 병적 상태들이 이러한 해부학적 부위를 침범할 수 있다. 다중 검출 전산화단층촬영은 다양한 기도 질환들의 진단을 위한 발견 및 특성화에 있어 중요한 역할을 한다. 가상 기관지경 검사나 자동 폐분석과 같은 후처리를 통해 영상 영상검사의 활용이 더욱 높아질 수 있다. 본 임상 화보에서는 벽비후와 기관 내 결절의 형태로 나타나는 다양한 기관지 병변들의 다중 검출 전산화단층촬영에서의 소견 및 고차원적 영상 시각화와 분석 영상을 제공하고자 한다.

• 한국컴퓨터정보학회논문지
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• 제18권10호
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• pp.97-107
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• 2013

최근의 프로그래밍 패러다임은 객체지향프로그래밍과 이를 기반으로 하는 비주얼프로그래밍이 주류를 이루고 있다. 그러나 객체지향프로그래밍은 기존의 구조적프로그래밍기법에 비하여 개념이 어렵고 복잡하여 IT 관련학과 학생들을 교육하기에 어려움이 많았다. 본 연구에서는 학생들이 다양한 입출력 장치를 부착하고 로봇제어가 가능한 트레이닝 키트를 사용하여 객체지향 프로그래밍 학습 의욕 고취와 동기를 유발할 수 있도록 Java 가상머신을 내장한 Java 로봇 트레이닝 키트를 설계하고 구현하였다. 개발된 Java 로봇 트레이닝 키트는 USB 인터페이스로 컴퓨터와 통신 가능하며, 다양한 입출력 장치와 DC 모터 및 서보모터를 구동할 수 있는 범용 입출력 포트를 내장하여 교육용 로봇제작과 응용프로그래밍 실습이 가능하다. 따라서 IT 융합시대를 맞이하여 학문과 전공간의 벽이 낮아지고 창의 공학적 객체지향 프로그래밍언어 교육의 도입이 필요한 시점에서 본 연구에서 개발한 Java 로봇 트레이닝 키트가 많은 기여를 할 것으로 기대된다.

• 한국BIM학회 논문집
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• 제2권1호
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• pp.1-6
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• 2012

With the increased awareness of energy consumption as well as the environmental impact of building operations, architects, designers and planners are required to place more consideration on sustainability and energy performance of the building. To ensure most of those considerations are reflected in the building performance, critical design decisions should be made by key stakeholders early during the design development stage. The application of BIM during building energy simulations has profoundly improved the energy analysis process and thus this approach has gained momentum. However, despite rapid advances in BIM-based processes, the question still remains how ordinary building stakeholders can perform energy performance analysis, which has previously been conducted predominantly by professionals, to maximize energy efficient building performance. To address this issue, we identified two leading building performance analysis software programs, Energy Plus and IES (IES ), and compared their effectiveness and suitability as BIM-based energy simulation tools. To facilitate this study, we examined a case study on Building Performance Model (BPM) of a single story building with one door, multiple windows on each wall, a slab and a roof. We focused particularly on building energy performance by differing building orientation and window sizes and compared how effectively these two software programs analyzed the performance. We also looked at typical decision-making processes implementing building energy simulation program during the early design stages in the U.S. Finally, conclusions were drawn as to how to conduct BIM-based building energy performance evaluations more efficiently. Suggestions for further avenues of research are also made.

• 한국컴퓨터정보학회논문지
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• 제25권1호
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• pp.101-107
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• 2020

사용자가 건물 안과 같은 실내 환경에서 외부에 존재하는 목적 공간의 상황들을 확인하고 해당 공간의 정보들을 확인하고 이동한다. 하지만 사용자가 있는 공간과 목적지의 공간을 확인 하면서 길을 찾기가 어렵다는 단점이 있다. 본 논문에서는 사용자가 상호작용하는 원격 공간 정보를 실시간 스트리밍을 통해 사용자가 현재 있는 공간과 적절하게 정합 되어 원격 공간을 보이는 혼합현실 기반의 실감 투시 가시화 기법을 제안한다. 제안된 방법을 사용하여 사용자는 자신이 현재 있는 방의 공간 어느 방향에서도 원격에 존재하는 공간과 자연스러운 연결을 하고 해당 공간으로 몰입하여 들어가서 원격 공간에 있는 사람들 및 객체들과 상호작용을 할 수 있다. 본 논문에서 제안한 방법을 사용한 경우 실내의 위치를 찾을 때 기존 방법에 비해서 30% 더 빠르게 찾을 수 있었다.

• 한국실내디자인학회논문집
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• 제25권5호
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• pp.111-120
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• 2016

Unlike the past, brick-and-mortar is no longer on the priority list for the shopping activity. Instead, it is replaced by various non-store shopping alternatives, such as Internet, TV, catalog, mobile, etc. As consumers engage digitally, they made fewer trips to stores. Especially, as mobile shopping made the price comparison possible while shopping in the store, new shopping trend of 'showrooming' came to the fore as the serious issue. In order to cope with the this crisis, many brick-and-mortar retailers utilize omni-channel strategy for their countermeasure. This research paper is to suggest the omni-channel strategy that is applicable for the brick-and-mortar retailers. The results are as follows. First, in order to set up the connected-channel shopping environment, consumers have to be exposed to the environment that can deliver the continuous brand experience under the same price policy, brand and store management, etc, as integrating the various purchasing channels into one. Especially, in-store environment needs to change for the place where consumer experience is stressed for the most as using virtual reality devices with augmented reality technology. Also, the online digital kiosk, and tablet that consumer can order the products through the online channel while shopping in-store Second, the barrier-free in-store environment should be offered in order to increase the consumer convenience. This change will allow consumer communicate with the store environment more effectively. Lastly, brick-and-mortar should extend the physical territory as utilizing the offline's advantage and disadvantage through setting up the digital interactive wall or pop-up store for increasing the opportunity of customer interaction with the store. Moreover, visiting service for the elderly, housewife with the baby, or disabled person will be one of the effective substitute.