• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.402-407
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• 2010

Introduction: The planning of implant surgery is an important factor for the implant prosthesis. Stereolithographic (SLA) surgical stents based on a computer simulation are quite helpful for clinicians to perform the surgery as planned. Although many clinical and technical trials have been performed for computed tomography (CT)-guided implant stents to improve the surgical procedures and prosthetic treatment, there are still many problems to solve. We developed a system of a surgical guide based on 3 dimensional (3D) CT for implant therapy and achieved satisfactory results in the terms of planning and operation. Materials and Methods: Fifteen patients were selected and 30 implant fixtures were installed. The preoperative CT data for surgical planning were prepared after obtaining informed consent. Surgical planning was performed using the simulation program, Ondemend3D In2Guide. The stents were fabricated based on the simulation data containing information of the residual bone, the location of the nerve, and the expected design of the prostheses. After surgery with these customized stents, the accuracy and reproducibility of implant surgery were evaluated based on the computer simulation. The data of postoperative CT were used to confirm this system using the image fusion technique and compare the implant fixtures between the planned and implanted. Results: The mean error was 1.18 (${\pm}0.73$) mm at the occlusal center, 1.23 (${\pm}0.67$) mm at the apical center, and the axis error between the two fixtures was $3.25^{\circ}C$ (${\pm}3.00$). These stents showed superior accuracy in maxilla cases. The lateral side error at the apical center was significantly different from the error at the occlusal center but there were no significant differences between the premolars, 1st molars and 2nd molars. Conclusion: SLA surgical stents based on a computer simulation have the satisfactory accuracy and are expected to be useful for accurate planning and surgery if some errors can be improved.

• KIEAE Journal
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• 제10권2호
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• pp.63-69
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• 2010

Diverse problems in wind environment has occurred through rapid urbanization and growth of high-rise building numbers, This study aims to propose the CFD (Computational Fluid Dynamics) simulation method and evaluation standard of wind environment in site planning of high rise apartment housing. The CFD simulation method proposed in this study is not existing detail simulation, but it is the method that a designer can correct and develop the design through immediate evaluation of design options in concept design phase. Therefore, the proposed CFD simulation method of wind environment in this study uses the BIM based CFD tool in which the 3D model in concept design phase can be used as for the CFD simulation. In this paper, the study examines existing evaluation standards of comfortableness level in wind environment for pedestrian near buildings, and selects new evaluation method which is possible to apply to the proposed CFD simulation method. In addition, it is to examine calculation time-spending and appropriate mesh division method for finding CFD result which is useful to find the best design options in aspect of wind environment in concept design phase. Furthermore, it proposes the wind environment evaluation method through BIM based CFD simulation.

• 한국통신학회논문지
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• 제23권9A호
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• pp.2221-2229
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• 1998

핸드오프는 CDMA 망에서 시스템의 성능과 용량 등 망설계에 영향을 미치는 매우 중요한 변수인데 본 논문에서는 1.9GHz대의 주파수대역에서 전자파전파모델, IS-95A에서 권고한 소프트 핸드오프 알고리즘, 그리고 무선망설계 변수에 대한 연구를 통하여 소프트핸드오프가 CDMA 무선망설계에 미치는 영향을 분석하기 위한 시뮬레이션틀을 개발하였다. 이를 이용하여 소프트핸드오프 이득, 소프트핸드오프가 CDMA 시스템 성능과 용량에 미치는 영향등을 종합적으로 분석하였다. 본 셀설계 틀과 분석자료는 PCS와 차세대이동통신과 같은 1.9GHz대역에서의 CDMA 디지털 이동통신환경에서의 무선망설계시에 기지국선정과 시스템 파라미터 최적화 등과 같은 효율적인 무선망설계에 활용될 수 있을 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.916-919
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• 2004

In this paper, we proposed a new method of pre-operative planning for tibial deformity correction using double hexapod external fixator in pseudoacondroplasia. The 3-D computer graphic model of deformed tibia was reconstructed from 3 mm sliced CT data, and CAD model of double hexapod external fixator was developed. The fixator was composed of 170 mm diameter of three rings and 90 mm of twelve struts. The bone deformities and the osteotomy lines for double osteotomy were measured using X-rays, and the necessary joint values to correct the given deformities were obtained by inverse kinematics analysis. The computer graphic simulation was performed to visualize the deformity correction process and evaluate the analysis result. By examining the pre-op and post-op X-rays, the simulation result was in good agreement with the clinical outcomes.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.91-91
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• 2001

This paper is on 3D virtual reality simulator for terminal in connection with terminal operation system in real terminal in order to reflex complicated terminal operation and environment. This simulator has been developed based on knowledge of terminal planning and operation analysis and advanced software technologies that TSB has accumulated over 10 years. In this study, the simulator generates terminal layout and component of terminal in the same environments as the real terminal in Ohi, Japan and uses real operation system using real planning data in the past in order to describe 3D VR simulation that integrates container handling equipment and real time communication of job ordering. In addition, it is suggested various statistics and analysis report can be used to derive decision supporting factors that optimize design of terminal and improve operation, which will eventually increase terminal productivity.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.71-82
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• 2009

This paper describes the use of a highly interactive and inter-operative application for complex simulation environments, or Synthetic Environments (SE), as deployed for construction as Construction Synthetic Environments (CSE). Based on the High Level Architecture (HLA), this research focuses on implementing simulation technology in a software environment, COSYE, that will be the foundation for building CSE applications. This framework is discussed in the context of tunneling and industrial construction applications, including steel fabrication and pipe-spool manufacture. The framework is demonstrated using the NEST sanitary tunnel project in Edmonton, Canada, in which COSYE was used for scenario-based analysis and planning.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1194-1201
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• 2022

The existing literature has witnessed the importance of productivity assessment and deducing factors affecting it. However, yet many models have shown limitations in practical applications in actual construction sites for process planning due to uncertainty and lack of data. This research presents a productivity assessment and database generation framework using simulation and compares the results with RSMeans to derive appropriate equipment combinations alternatives for earthwork operations. Data of 15 different conditions was collected from 5 different construction sites. Prediction accuracy above 90% were achieved for the simulation models with average error rate of 7.4%. The construction productivity assessment framework presented in this study is expected to be highly applicable to operation planning for earthwork operations.

• 소성∙가공
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• 제14권8호통권80호
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• pp.675-680
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• 2005

This study was aimed at the design of the dies for the automobile part for the engine oil leakage prevention using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation,'eesy-2-form' of 2D FEM simulation package and 'eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the simulation of 'eesy-2-form', we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of 'eesy-DieOpt', we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for cold forging has been developed.

• 대한조선학회논문집
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• 제44권6호
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• pp.647-656
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• 2007

Simulation model of outdoor block movement of shipyard is implemented in this paper. The load of the outdoor workshops in a shipyard influences a mid-term planning and scheduling of the shipyard. Since the load analysis is expected in advance before confirming the planning and scheduling, a discrete event simulation (DES) may be a good solution. The accuracy of DES is up to the accurate modeling of Products, Processes, and Resources (PPR) included in a system. PPR in the outdoor system are clearly defined and the simulation model for the outdoor logistics is implemented by modeling the selective PPR with the help of a DES tool which is programmable by users. The simulation model is verified by comparing the results with the real shipyard data. The outputs through the simulation are discussed.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.639-640
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• 2015

Traditional construction planning based on historical data and heuristic adjustment can no longer incorporate all the operational details and guarantee the expected performance. The variation between the expected and the actual production leads to cost overruns or delay. Although predicting reliable productivity on construction site is getting more important, the difficulty of this increases. In this regard, this paper suggested to develop BIM-integrated simulation framework. This framework could predict productivity dynamics by considering factors affecting on construction productivity at operational phase. We developed the following processes; 1) enabling a BIM model to produce input data for simulation; 2) developing the construction operation simulation; 3) running simulation using BIM data and obtaining productivity results. The BIM-integrated simulation framework was tested with structural steel erection model because steel erection work is one of the most critical process influencing on the whole construction budget and duration. We could improve to predict more dynamic productivity from this framework, and this reliable productivity helps construction managers to optimize resource allocation, increase schedule reliability, save storage cost, and reduce material loss.