• Korean Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.168-176
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• 1998

This paper deals with an application on the mould machining of air intake hose product by using 3-dimensional parametric modeling techniques. The detailed domain is the 3-dimensional product with similar shapes and different sizes which needs too much working time for preparation of modeling or machining due to making a trial and errors repeatedly. Decision making rules for selection of modeling order and technique, and for calculation of cutting conditions, and for determination of sequence and method concerning machining operations are required by interview of expert engineers in the field. The developed expert system of modeling and machining is programmed by using a user programming language under the CAD/CAM software of the Personal Designer. The developed system that aids a mould engineer who is working in the modeling and machining section which deal with air intake hose product provides strong and useful capabilities.

• Archives of design research
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• v.14
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• pp.87-106
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• 1996

Recent rapid development of electronic technologies and semiconductors has made it possible to perform diverse intelligent functions even in simple products. This technological sophistication, in turn, made it difficult to get required information on the usage of products by just its shape. Under these new circumstances, User-interface design became more important. However existing studies were mainly done with the emphasis of software development and focusing on the evaluation-stage after development of alternatives. This study sets the objective for developing modeling technique which can be applied to product design and the stage of concept development. At first the role of modeling was discussed to understand the nature of modeling. Then the existing techniques of modeling were reviewed for identifying advantages and limits. The review of existing modeling techniques revealed general objectives which new modeling techniques should fulfill. Based on objectives new modeling techniques were proposed. Following this new techniques, actual case of modeling a existing product were demonstrated to evaluate the validity of new technique and show the actual application. Finally findings were summarized and the limits of the study were identified.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.91-95
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• 2005

A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is developed instead of conventional lumped capacity nodes. The thermal plates are projected to the printed circuit board and can be modeled and modified easily by numerically preprocessing programs according to design changes. These modeling methods are applied to the thermal design and analysis of CTU and verified by thermal cycling and vacuum tests.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.103-111
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• 1998

This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.753-756
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• 2000

The accumulated know-how and trial-and-error procedures are known as the best ways to determine blank shape and dimensions. One of the most important steps to determine the blank shape and dimensions in deep drawing process is to calculate the surface area of the product. In general, the surface area of products is calculated by mathematical or 3-D modeling methods. A blank design system is constructed for elliptical deep drawing products to recognize the geometry of the product in the long side and short side by drafting in another two layers on AutoCAD software. This system consists of input geometry recognition module, 3-D modeling module and blank design module, respectively. Blank dimension of three types is determined by the same area, which was acquired in 3-D modeling module. The suitability of this system is verified by applying to a real deep drawing product.

• Korean Journal of Geomatics
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• v.1 no.1
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• pp.85-93
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• 2001

Geospatial database, which is the basis for Geo-Spatial Information Systems, is produced by conventional mapping methods. Recently, with increased demand for digital forms of the geospatial database, studies are carried out to automate its production. The automated mapping system is composed of the image acquisition subsystem, positioning subsystem, point referencing subsystem and the visualization subsystem. The image acquisition subsystem is the most important part of the overall production line because it is the starting point and will affect all subsequent processes. This paper presents a software analysis and design of the image acquisition subsystem. The design was carried out using the Unified Modeling Language which is a modeling method used extensively in the software engineering field.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.442-450
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• 2020

A small-signal modeling approach for a three-level boost (TLB) converter and a design methodology for a double-loop controller are proposed in this study. Conventional modeling of TLB converters involves three state variables. Moreover, TLB converters have two operation modes depending on the duty ratio. Consequently, complex mathematical calculations are required for controller design. This study proposes a simple system modeling method that uses two state variables, unlike previous methods that require three state variables. Analysis shows that the transfer functions of the two operation modes can be expressed as identical equations. This condition means that the linear feedback controller can be applied to all operational ranges, that is, for full duty ratios. The design method for a double-loop controller using a PI controller is presented in step-by-step sequences. Simulation and experimental verifications are conducted to verify the effectiveness of the small-signal analysis and control system design.

• Korean Journal of Computational Design and Engineering
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• v.6 no.3
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• pp.157-168
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• 2001

The description of enterprise activities is the basis fur process improvement and information system building. To describe such activities, it is necessary to model the enterprise activities from the abstraction level to the implementation level in a stepwise and integrated form. For this reason, several modeling approaches have been proposed. However, most of them lacked the stepwise or integration aspects although some of them covered overall levels. This study proposes the hierarchical modeling approach for integrating the enterprise activity model from the abstraction level to the implementation level systematically. It is composed of five modeling levels such as function level, process level, task level, document workflow level, and event flow level. This study discusses the definition and characteristics of each level and compare our modeling frame with other modeling methodologies in case study.

• Korean Journal of Computational Design and Engineering
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• v.7 no.4
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• pp.240-247
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• 2002

Most commercial CAD systems provide parametric modeling functions, and by using these capabilities designers can edit a CAD model in order to create design variants. It is necessary to transfer parametric information during a CAD model exchange to modify the model inside the receiving system. However, it is not possible to exchange parametric information of CAD models based on the cur-rent version of STEP. The designer intents which are contained in the parametric information can be lost during the STEP transfer of CAD models. This paper introduces a hybrid CAB model translator, which also uses the feature tree of commercial CAD systems in addition to the macro file to allow transfer of parametric information. The macro-parametric approach is to exchange CAD models by using the macro file, which contains the history of user commands. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. As a neutral fie format, a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined. The scope of the current version is limited to parts modeling and assemblies are excluded.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.49-56
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• 2006

In this study, the modeling support system was developed which can make easy and fast FE-modeling and verify the results of static and durability analysis for the lower arm, one of the important parts in automobile suspension module. It took into account of the whole complicated design processes verifying the durability coefficients evaluated by fatigue analysis, which should be used to satisfy a design criteria. To guide the FE-modeling the drive page was constructed by using HTML and XML, which was based on expert's know-hows. It is able to integrate the processes to design the lower arm in practice, so that the standardization of its FE-Modeling is achieved, consequently. The 3 dimensional CAD's geometrical data were changed automatically into pre-defined shell elements under the concept of mesh-offset technique, and then welding elements were treated to connect between target and basic surfaces constructed by the shell elements. This system has also a user interface to control boundary and load ing conditions applied in performing of the static and durability analysis, in which many load cases can be applied simply with the MPCs driven by just few mouse clicks. These were implemented on the platform of MSC.Patran and utilized ANSYS, MSC.Nastran and MSC.Fatigue as the solver of the analysis performed. The developed system brings not only significant decreasing of man-hours required in FE-modeling process, but also obtaining of satisfied qualities in analyzed results. It will be integrated in a part of virtual prototyping module of the developing e-engineering framework.