• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.62-67
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• 2007

The research team for the virtual construction development was established with the support of Korea Ministry of Construction and Transportation, and KICTEP (Korea Institute of Construction and Transportation Technology Evaluation and Planning). Its aims are to develop system that is to improve productivity & quality, to create a higher value-added business, and to cultivate international competitiveness in the construction industry. The virtual construction system is a design, engineering, and construction management information system that allows the project participants to effectively share the information throughout the construction life cycle with the support of 3D and design information. To achieve this, the research team focuses on developing several systems. First, the team focuses on developing for the pre-planning, the structural engineering, MEP, and the 3D based estimation system. Second, they focus on developing a simulation system for the construction process planning and feasibility study with help of the virtual reality technologies. Third, they focus on developing the CPLM (Construction Project Life-cycle Management) system for managing construction project data, and the decision support system that makes the collaboration among the project participants based on 3D technologies and information. We also focus on developing the SDAI (Standard Data Access Interface), the localized guideline for 3D design, and a training program. In addition, we focus on developing the undeveloped area of the commercial system and building an environment that can support the communication and collaboration in the construction life-cycle rather than developing the existing and commercialized system.

• 산업공학
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• 제15권4호
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• pp.356-363
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• 2002

Virtual Manufacturing is a technology to facilitate effective product development and agile production by computer models representing the physical and logical schema and the behavior of real manufacturing systems including manufacturing resources, environments and products. For the successful application of this technology, a virtual factory as a well-designed and integrated environment is essential. In this research, we constructed a sophisticated virtual factory model of an automotive company's paint shop, and performed precise simulations of unit cells, lines and whole plant operations for collision check and off-line programming. It is expected that this virtual paint shop is useful for achieving time and cost savings in many manufacturing preparation and planning activities of new car development processes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.74-89
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• 2021

For higher-level requirements of urban planning and management and the recent development of "digital earth" and "digital city", it is urgent to establish protocols for the construction of three-dimensional digital city models. However, some problems still exist in the digital technology of the three-dimensional city model, such as insufficient precision of the three-dimensional model, not optimizing the scene and not considering the constraints of building codes. In view of those points, a method to interactively simulate a virtual city scene based on building codes is proposed in this paper. Firstly, some constraint functions are set up to restrict the models to adhere to the building codes, and an improved directional bounding box technique is utilized to solve the problem that geometric objects may intersect in a virtual city scene. The three-dimensional model invocation strategy is designed to convert two-dimensional layouts to a three-dimensional urban scene. A Leap Motion hardware device is used to interactively place the 3D models in a virtual scene. Finally, the design and construction of the three-dimensional scene are completed by using Unity3D. The experiment shows that this method can simulate urban virtual scenes that strictly adhere to building codes in a virtual scene of the city environment, but also provide information and decision-making functions for urban planning and management.

• 한국정밀공학회지
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• 제25권8호
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• pp.37-44
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• 2008

Nowadays, the increasing global competition forces manufacturer to reduce the cost and time for implementation of manufacturing system. The AR(augmented reality) technology as a new human-machine interface introduces a noteworthy perspective for a new manufacturing system design. Using AR technology, a physically existing production environment can be superimposed with virtual planning objects. Therefore, the planning tasks can be validated without modeling the surrounding environment of the production domain during short process planning time. In this paper, we introduce the construction of AR browser and determine the optimal environment parameters for field application of AR system through lots of tests. And, many methods such as multi-marker coordinate system, division of virtual objects and so on, are proposed in order to solve the problems suggested from initial field test. Based on these tests and results, the test-bed of C/Pad assembly system is configured and robot program for C/Pad assembly is generated based on AR system.

• 대한조선학회논문집
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• 제45권5호
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• pp.547-553
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• 2008

Multi Progress Planning System problem in a multi-stage manufacturing system have a complexity and peculiarity different from other kinds of production system. World leading company has invested much cost and effort into a Real-Time Planning System and intelligent manufacturing field to obtain their own competitiveness. Especially Real-Time Planning System for ship production process as a part of intelligence for a shipyard. Real-Time Planning System, simulation based system, or virtual manufacturing system is an approach to achieve a such goal. It is expected that the Real-Time Planning System will contribute to the improvement of the productivity in working process at a shipyard. Also, This Real-Time Planning System will optimize the entire shipbuilding process in a multi progress planning environment for the delivery.

• 지능정보연구
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• 제7권1호
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• pp.1-15
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• 2001

최근 인터넷의 급속한 확산에 따른 전자상거래의 활성화는 조직과 규모 면에서 열세인 중소기업들의 판로 확장 및 홍보를 위한 새로운 대안으로 인식되고 있다. 그러나, 전자상거래 환경은 비약적으로 성장하고 있지만, 여전히 국내 중소기업들은 인력 및 자금의 상대적인 열세로 이러한 환경변화에 효과적으로 대응치 못하고 있다. 본 논문은 이러한 문제를 해결하기 위한 노력의 일환으로, 인터넷 상의 판매 에이전트를 지원할 수 있는 가상생산 에이전트(Virtual Manufacturing Agent)의 개발에 관한 내용을 담고 있다. 제품의 흥보, 주문의 선택 및 수락 여부에 대한 결정은 생산라인의 상태와 매우 밀접한 관계에 있다. 주문의 수락과 주문 조건에 대한 협상을 위해서는 제조가능성 여부, 생산 부하 및 생산일정 등에 대한 정보가 필요하다. 본 논문에서는 중소제조업체의 판매활동을 인터넷상에서 가능하게 하는 판매에이전트가 요구하는 생산정보를 적시에 제공할 수 있는 가상생산 에이전트를 설계, 구현하였고, 이를 통하여 구현된 시스템을 사출금형제조업체의 생산과정과 주문처리과정을 통하여 검증하였다.

• 대한치과교정학회지
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• 제53권1호
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• pp.26-34
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• 2023

Objective: The purpose of the present study was to compare the root positions in virtual tooth setups using only crowns in a simulated treatment with those achieved in the actual treatment. Methods: Pre- and post-treatment intraoral and corresponding cone beam computed tomography (CBCT) scans were obtained from 15 patients who underwent orthodontic treatment with premolar extraction. A conventional virtual tooth setup was used for the treatment simulation. Pre- and post-treatment three-dimensional digital tooth models were fabricated by integrating the patients' intraoral and CBCT scans. The simulated root positions in the virtual setup were obtained by merging the crown in the virtual setup and root in the pre-treatment tooth model. The root positions of the simulated and actual post-treatment tooth models were compared. Results: Differences in root positions between the simulated and actual models were > 1 mm in all teeth, and statistically significant differences were observed (p < 0.05), except for the maxillary lateral incisors. The differences in the inter-root angulation were > 1° in all teeth, and statistically significant differences were observed in the maxillary and mandibular canines. Conclusions: The virtual tooth setup using only crown data showed errors over the clinical limits. The clinical application of a virtual setup using crowns and roots is necessary for accurate and precise treatment simulation, particularly in extraction treatment.

• 한국CDE학회논문집
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• 제14권1호
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• pp.42-49
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• 2009

Virtual manufacturing technology has been applied in actual production sites with the development of virtual reality technology. However, the current virtual manufacturing technology requires experts for application of the system. Furthermore, the sense of reality is diminished as the entire simulation is driven by virtual objects. In contrast, mixed reality can visualize virtual objects and an actual work place simultaneously, and thus the sense of reality of the virtual manufacturing simulation can be improved. This paper introduces a method that applies mixed reality in the manufacturing process, and proposes a method to adapt general safety sign post in the factory instead of a black square marker for visual fiducial recognition.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권5호
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• pp.231-232
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• 2019

• 대한산업공학회지
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• 제29권1호
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• pp.49-64
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• 2003

Although assembly sequence planning is an essential task in assembly process planning, it is known as one of the most difficult and time consuming jobs because its complexity is increased geometrically when the number of parts in an assembly is increased. The purpose of this study is to develop a more efficient algorithm for generating assembly sequences automatically. By considering subassemblies, a new heuristic method generates a preferred parallel assembly sequence that can be used in robotic assembly systems. A parallel assembly sequence concept provides a new representation scheme for an assembly in which the assembly sequence precedence information is not required. After an user inputs both the directional mating relation information and the mating condition information, an assembly product is divided into subgroups if the product has cut-vertices. Then, a virtual disassembly process is executed to generate alternate parallel assembly sequences with intermediate assembly stability. Through searching parts relations in the virtual disassembly process, stable subassemblies are extracted from translation-free parts along disassembling directions and this extraction continues until no more subassemblies are existed. Also, the arithmetic mean parallelism formula as a preference criterion is adapted to select the best parallel assembly sequence among others. Finally a preferred parallel assembly sequence is converted to an assembly BOM structure. The results from this study can be utilized for developing CAAPP(Computer-Aided Assembly Process Planning) systems as an efficient assembly sequence planning algorithm.