• 한국전자거래학회지
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• 제14권1호
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• pp.35-56
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• 2009

프로세스 설계에는 Petri-net, EPC, UML Activity Diagram 등 다양한 모델 기법이 사용되고 있다. 업무 프로세스 내에 복잡한 업무 규칙이 다수 결합되어 있거나, 유비쿼터스 컴퓨팅과 같이 분산 환경에서 복합한 상호운용 규칙이 산재되어 있는 경우에는 정형적인 프로세스 모델링 기법이 비효율적이므로 규칙 기반의 분산 프로세스 설계를 사용할 수 있다. 본 연구는 유비쿼터스 환경에서의 규칙 기반 프로세스 설계 방법을 분석한다. 특히, 이벤트-조건-액션(ECA) 형태의 능동형 규칙을 이용한 프로세스 설계를 대상으로 분석하며, ECA 스키마는 웹 서비스 기술을 위해 개발된 WS-ECA 언어를 사용한다. ECA 규칙을 이용한 여러가지 프로세스 통제 흐름 표현 방법을 분석하기 위하여 워크플로우 패턴을 활용하였다. 워크플로우 패턴에 따라 ECA 규칙 기반 프로세스 표현법을 제공함으로써 규칙 기반 프로세스를 설계하기 위한 가이드라인을 제시하였다는 데 연구의 의의가 있다.

• Wind and Structures
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• 제11권6호
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• pp.479-496
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• 2008

In this paper, computer simulation of wind flow around a single cooling tower with louver support at the base in the KAZERUN power station in south part of IRAN is presented as a case study. ANSYS FLOTRAN, an unstructured finite element incompressible flow solver, is used for numerical investigation of wind induced pressure load on a single cooling tower. Since the effects of the wind ribs on external surface of the cooling tower shell which plays important role in formation of turbulent flow field, an innovative relation is introduced for modeling the effects of wind ribs on computation of wind pressure on cooling tower's shell. The introduced relation which follows the concept of equivalent sand roughness for the wall function is used in conjunction with two equations ${\kappa}-{\varepsilon}$ turbulent model. In this work, the effects of variation in the height/spacing ratio of external wind ribs are numerically investigated. Conclusions are made by comparison between computed pressure loads on external surface of cooling tower and the VGB (German guideline for cooling tower design) suggestions.

• 대한조선학회논문집
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• 제44권4호
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• pp.451-458
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• 2007

A preliminary design approach for superyachts is introduced. The state-of-the-arts of superyachts is investigated and their characteristics are indirectly examined by analyzing the data collected from built vessels. The analysis of data provides a guideline for the establishment of an preliminary hull form of a superyacht. The rules and regulations governing the design and construction of superyachts are collected and considered. A modeling approach for prompt and efficient design is also introduced. A sample hull form of a selected superyacht is constructed using commercial design packages not only to produce a hull form but to analyze the hydrostatic and hydrodynamic performances of the constructed vessel. Various visualization techniques are considered as an efficient tool for design verification.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.329-336
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• 2006

The resistance spot-welded region in most current finite element crash models is characterized as a rigid beam at the location of the welded spot. The region is modeled to fail with a failure criterion which is a function of the axial and shear load at the rigid beam. The calculation of the load acting on the rigid beam is important to evaluate the failure of the spot-weld. In this paper, numerical simulation is carried out to evaluate the calculation of the load at the rigid beam. At first, the load on the spot-welded region is calculated with the precise finite element model considering the residual stress due to the thermal history during the spot welding procedure. And then, the load is compared with the one obtained from the model used in the crash analysis with respect to the element size, the element shape and the number of imposed constraints. Analysis results demonstrate that the load acting on the spot-welded element is correctly calculated by the change of the element shape around the welded region and the location of welded constrains. The results provide a guideline for an accurate finite element modeling of the spot-welded region in the crash analysis of vehicles.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.

• 한국정밀공학회지
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• 제25권10호
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• pp.107-114
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• 2008

The aim of this study is to obtain the useful design guideline for high impulsive force device with an isolation system by the analytic approach of dynamics characteristics. In this study, the high impulsive force system was modeled and analyzed in view of multi-body dynamics, and verified the modeling and analysis result by the experiment of the high impulsive force device. Additionally, the dynamic analysis was performed for the isolation system with the selected coefficients of elastic spring and damper selected. Experimental result for the high impulsive force device with the isolation system was compared and analyzed. From the result, it was confirmed that the design guideline for the isolation system of the high impulsive force device was useful.

• Korea-Australia Rheology Journal
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• 제16권1호
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• pp.27-33
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• 2004

Application of gas assisted injection molding has been expanded during last two decades because of many advantages such as design flexibility, dimensional stability, reduction of machine tonnages, and so on. However, the surface defects including hesitation mark and gloss difference are observed for thick parts. Difficulties in lay-out of the gas channel and processing condition are another disadvantages. Liquid gas assisted injection molding(LGAIM), in which a liquid with a boiling point lower than the temperature of the polymer melt is injected into the melt stream, and travels with the melt into the mold where it vaporizes and pushes the melt downstream and against the cavity walls to create hollow channels within the part, is a good alternative of the conventional gas assisted injection molding especially in manufacturing simple and very thick parts. Though this is a new frontier of the innovation in the injection molding industry, there is no guideline for the design and processing conditions. In this paper, theoretical analysis has been made to describe the hollow formation dynamics in LGAIM. This model provides an insight into LGAIM process: explains why LGAIM has advantages over conventional gas assisted injection molding, and gives a guideline for the design and processing conditions.

• Earthquakes and Structures
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• 제8권6호
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• pp.1435-1452
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• 2015

The performance of masonry infilled frames during the past earthquakes shows that the infill panels play a major role as earthquake-resistant elements. Experimental observations regarding the influence of infill panels on increasing stiffness and strength of reinforced concrete structures reveal that such panels can be used in order to strengthen reinforced concrete frames. The present study examines the influence of infill panels on seismic behavior of RC frame structures. For this purpose, several low- and mid-rise RC frames (two-, four-, seven-, and ten story) were numerically investigated. Reinforced masonry infill panels were then placed within the frames and the models were subjected to several nonlinear incremental static and dynamic analyses. In order to determine the acceptance criteria and modeling parameters for frames as well as reinforced masonry panels, the Iranian Guideline for Seismic Rehabilitation of Existing Masonry Buildings (Issue No. 376), the Iranian Guideline for Seismic Rehabilitation of Existing Structures (Issue No. 360) and FEMA Guidelines (FEMA 273 and 356) were used. The results of analyses showed that the use of reinforced masonry infill panels in RC frame structures can have beneficial effects on structural performance. It was confirmed that the use of masonry infill panels results in an increment in strength and stiffness of the framed buildings, followed by a reduction in displacement demand for the structural systems.

• 한국정밀공학회지
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• 제21권9호
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• pp.77-84
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• 2004

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline, and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application, as the attaching force of the vehicle can be affected by its posture.

• 한국BIM학회 논문집
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• 제13권2호
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• pp.47-57
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• 2023

The purpose of this study is to propose a guideline to help the client and bidder operate the BIM project in the domestic road field. As BIM design is mandatory in the construction field, documents disclosed by the ordering agency must essentially include procedures and step-by-step requirements to support BIM. The purpose of this study is to propose the structure and components of the guidelines that practitioners need practically by utilizing the currently announced road field guidelines. The guidelines are analyzed based on the procurement documents that were pre-emptively shared overseas, and supplemented according to the domestic situation. Furthermore, the effectiveness of the revised guidelines is confirmed through expert consultation. This study aims to contribute to creating an environment in which construction practitioners who have no experience in BIM project can efficiently carry out BIM projects.