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Computer-aided design, engineering, and manufacturing (CAx) have improved product design and development. The associativity of revised design in native files for downstream applications, assembly design, finite element analysis, and... more
Computer-aided design, engineering, and manufacturing (CAx) have improved product design and development. The associativity of revised design in native files for downstream applications, assembly design, finite element analysis, and numerical control (NC) manufacturing has been supported by homogeneous CAx systems. However, heterogeneous CAx environments have issues when neutral models are revised and re-imported because the required identification information is missing. This results in a problem of the associativity of neutral models. In this study, different computer-aided design (CAD) applications have been analyzed with respect to their capabilities for import and export of neutral models with identification information. A tool has been selected to demonstrate the key findings. Moreover, future directions have been discussed to solve associativity issues in design re-import based on neutral models.
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In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for... more
In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for ready-made parts, existing e-Catalog systems cannot support the above trade pattern. To solve this problem, an ETO (engineering-to-order) method is proposed here, enabling the trade of order-made parts in an e-Catalog system by utilizing the design and manufacturing knowledge of the part suppliers. After addressing technological challenges and solutions, we briefly describe application of the ETO method to two types of mold parts - ejector pins and mold bases.
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This paper presents the KAIST interactive bicycle racing simulator system, which consists of a pair of bicycle simulators. The rider on the racing simulator experiences realistic sensations of motion, while being able to see the other... more
This paper presents the KAIST interactive bicycle racing simulator system, which consists of a pair of bicycle simulators. The rider on the racing simulator experiences realistic sensations of motion, while being able to see the other bicycle simulator and having the audio-visual experience of riding in a velodrome or on the KAIST campus. The 2nd bicycle of the racing simulator
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The digital parts libraries or electronic parts catalogs have opened up a vast potential for new electronic forms of product components procurement. However, their seamless integration is impeded by the mismatches of their ontologies. The... more
The digital parts libraries or electronic parts catalogs have opened up a vast potential for new electronic forms of product components procurement. However, their seamless integration is impeded by the mismatches of their ontologies. The origin of the ontology mismatches is the differences in the way the given domain is interpreted (conceptualized). In this paper, we discuss content-oriented knowledge modeling
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In this paper, we propose a framework for authoring and controlling motion effects of 4D theaters. Regular and newly released movies are presented with some special effects such as motion, vibration, wind, fog, and scent at some theaters... more
In this paper, we propose a framework for authoring and controlling motion effects of 4D theaters. Regular and newly released movies are presented with some special effects such as motion, vibration, wind, fog, and scent at some theaters in South Korea. We define a neutral motion data with human-centered motion parameters based on human's sensory physiology and motion psychophysics. As a result, we can be sure that all theaters can be interoperable with different kinds of motion platforms.
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In order to simulate and visualize natural phenomena, especially fluid behavior such as smoke and fire, many novel studies have recently been conducted. Usually these methods use CFD (computational fluid dynamics), which calculate... more
In order to simulate and visualize natural phenomena, especially fluid behavior such as smoke and fire, many novel studies have recently been conducted. Usually these methods use CFD (computational fluid dynamics), which calculate Navier-Stokes equations in real-time to generate realistic fluid motion and interactions, as well as high-performance GPU technologies. We proposed a new approach to the visual simulation of
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Many researches about the data exchange between CAD systems have been going on since 1980s. Macro-parametrics is a methodology for the exchange of the CAD data using a macro file which is a record of commands in the CAD system and the... more
Many researches about the data exchange between CAD systems have been going on since 1980s. Macro-parametrics is a methodology for the exchange of the CAD data using a macro file which is a record of commands in the CAD system and the best way to translate design intend. Two kinds of naming method are used in these macro files, one is the geometry-based naming method and the other is the topology-based naming method. A new naming method defined by icad laboratory in the neutral macro file is used for the exchange between these two naming methods, but there are some problems in the name of entities used in this neutral file. The point-based naming method is suggested to solve this problem. The name of the point is defined by the name of sketch which is defined by topological information and local coordinate value which is geometrical information. And names of the face and the edge are also defined using this point name.
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Virtual digital mock-up (v-DMU) refers to all of the activities in the design, analysis, and visualization of the product in a 3D virtual environment that lead to a lower cost and a higher quality. In the early days, designers exchanged... more
Virtual digital mock-up (v-DMU) refers to all of the activities in the design, analysis, and visualization of the product in a 3D virtual environment that lead to a lower cost and a higher quality. In the early days, designers exchanged CAD files directly in collaborations. ...
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In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for... more
In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for ready-made parts, existing e-Catalog systems cannot support this trade pattern. To solve this problem, an engineered-to-order (ETO) approach is proposed here, enabling the trade of order-made parts in an e-Catalog system by utilizing the design and manufacturing knowledge of part suppliers. After addressing technological challenges and their solutions, we describe application results of the ETO approach to two types of mold parts — ejector pins and mold bases.
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It is difficult to access and share design data among heterogeneous CAD systems. Usually different CAD systems exchange design data using a neutral format such as IGES or STEP. A prototype STEP database has been implemented. The prototype... more
It is difficult to access and share design data among heterogeneous CAD systems. Usually different CAD systems exchange design data using a neutral format such as IGES or STEP. A prototype STEP database has been implemented. The prototype system uses the OpenCascade geometric kernel and the commercial object-oriented database ObjectStore. STEP provides the database schema. The STEP database has been accessed and manipulated from commercial CAD systems of SolidWorks and Unigraphics. The data access module of the commercial CAD system has been developed by using the CAD system’s native API, ObjectStore API, and ActiveX.
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ABSTRACT Procedural models have the advantage of being easy to edit simply by changing the values of the parameters of their constructional operations. Such models are said to embody design intent, in the sense that modifications to them... more
ABSTRACT Procedural models have the advantage of being easy to edit simply by changing the values of the parameters of their constructional operations. Such models are said to embody design intent, in the sense that modifications to them conform to the method of creation used by their original creator. They also comply with any constraints implied by the particular constructional operations used. This paper introduces the development and standardization process of the ISO 10303-112 specification and describes the concept of procedural 2D modeling, a method of representing procedural 2D CAD models in STEP in harmony with other STEP resources. The feasibility of procedural 2D modeling commands for the exchange of procedurally represented 2D CAD model data is demonstrated through an experiment where procedural 2D CAD model data in neutral form generated with an in-house 2D modeling system are translated to and modified in a commercial 3D mechanical CAD system.
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ABSTRACT In the concept development phase, a designer wants to rapidly create a product’s overall shape and user interfaces by making simple sketches, known as ‘thumbnail sketches’, to evaluate ideas and possibilities. Free-hand 2D sketch... more
ABSTRACT In the concept development phase, a designer wants to rapidly create a product’s overall shape and user interfaces by making simple sketches, known as ‘thumbnail sketches’, to evaluate ideas and possibilities. Free-hand 2D sketch systems are regarded as a computerized tool for making thumbnail sketches. After the concept development phase, subsequent editing of the 3D data reconstructed from a free-hand 2D sketch with a 3D mechanical CAD system in the detail design phase is indispensable because inaccurate dimensions are inherent in a free-hand 2D sketch. For this reason, we present a new method to translate 3D data reconstructed from a free-hand 2D sketch into an editable form that reflects design intent so that the translated data can be directly used in 3D mechanical CAD systems. The feasibility of the proposed method has been demonstrated through experiments with prototype systems.
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This paper describes a method of geo-registering a sequence of panoramic images to a digital map by matching pixel information from the images with information on the building footprint contained in a digital map. Recently, images... more
This paper describes a method of geo-registering a sequence of panoramic images to a digital map by matching pixel information from the images with information on the building footprint contained in a digital map. Recently, images captured at the ground level using a Mobile Mapping System (MMS), such as the panoramic images displayed by Google Street View, have been considered as a valuable resource for three-dimensional (3D) building modeling. However, the wide intervals between these panoramic images, as well as locational and directional error from the related sensors, make it difficult to analyze the image data. This paper demonstrates a formulation method for connecting pixels in panoramic images with information on footprint vertices and building lines contained in a digital map. To allow both pixel and footprint information consistent in 3D space, each panoramic image is tilt-corrected in pre-processing to upright the image using the estimated pitch and roll of a vehicle and removing the pitch and roll effects from the panoramic image pixels. Through the proposed formulation, a single panoramic image can be easily geo-registered with simple user-provided constraints, and adjacent sequential images can then be automatically geo-registered using point feature matching. Experimental results showed a significant reduction in the locational and directional error of sequential panoramic images, and the proposed vanishing point (VP) based validation process was found to successfully detect failure cases.
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A flight simulator has different points to be considered compared to a driving simulator, because the operator can be located at any position of the virtual world. Especially, a helicopter moves more freely than a plane. We need more... more
A flight simulator has different points to be considered compared to a driving simulator, because the operator can be located at any position of the virtual world. Especially, a helicopter moves more freely than a plane. We need more considerations and it is more difficult to visualize the terrain and scene of the virtual world for a helicopter VR simulator. This paper introduces a method for constructing real-time terrain models for the VR simulator of a light helicopter, and introduces the problems and research issues that are found in this process.
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We present a technique to manage the silhouette of objects protruding from the surface without polygonal modeling of the object shape. The technique can represent the correct silhouette and the parallax of protruding shapes by solving the... more
We present a technique to manage the silhouette of objects protruding from the surface without polygonal modeling of the object shape. The technique can represent the correct silhouette and the parallax of protruding shapes by solving the overflow problem that frequently occurs in image-based displacement mapping approaches.
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Research Interests: Engineering, Computer Science, Computer Aided Design, Agricultural Biotechnology, Numerical Simulation, and 10 moreDesign process, Shipbuilding, Implementation, Data Exchange, Maritime Engineering, Marine Science and Technology, Electronic Data Interchange, Electronic Commerce, Hybrid Method, and Design Model
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Interoperability among heterogeneous Computed-Aided Design (CAD) systems is an important issue. With the advent of global outsourcing, collaborative design has expanded from inside the enterprise to parts suppliers. This paper introduces... more
Interoperability among heterogeneous Computed-Aided Design (CAD) systems is an important issue. With the advent of global outsourcing, collaborative design has expanded from inside the enterprise to parts suppliers. This paper introduces a method for design data exchange between shipyards and equipment suppliers. These parties usually use different CAD systems, because they want to select the most suitable one for their
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... Fig. 3 shows the architecture of the macro-parametric translator. The translation system has a macro input module, a macro output module, a graphical user interface, and a macro data translation module. ... Fig. 3. Architecture of the... more
... Fig. 3 shows the architecture of the macro-parametric translator. The translation system has a macro input module, a macro output module, a graphical user interface, and a macro data translation module. ... Fig. 3. Architecture of the macro-parametric translator. Fig. ...
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The engineering design process is a creative process, and the designers must repeatedly apply Undo/Redo operations to modify CAD models to explore new solutions. Undo/Redo has become one of most important functions in interactive graphics... more
The engineering design process is a creative process, and the designers must repeatedly apply Undo/Redo operations to modify CAD models to explore new solutions. Undo/Redo has become one of most important functions in interactive graphics and CAD systems. Undo/Redo in a collaborative CAD system is also very helpful for collaborative awareness among a group of cooperative designers to eliminate misunderstanding and to recover from design error. However, Undo/Redo in a collaborative CAD system is much more complicated. This is because a single erroneous operation is propagated to other remote sites, and operations are interleaved at different sites. This paper presents a multi-user selective Undo/Redo approach in full distributed collaborative CAD systems. We use site ID and State Vectors to locate the Undo/Redo target at each site. By analyzing the composition of the complex CAD model, a tree-like structure called Feature Combination Hierarchy is presented to describe the decompositi...
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In history based parametric CAD modeling systems, persistent identification of the topological entities after design modification is mandatory to keep the design intent by recording model creation history and modification history.... more
In history based parametric CAD modeling systems, persistent identification of the topological entities after design modification is mandatory to keep the design intent by recording model creation history and modification history. Persistent identification of geometric and topological entities is necessary in the product design phase as well as in the re-evaluation stage. For the identification, entities should be named first according to the methodology which will be applicable for all the entities unconditionally. After successive feature operations on a part body, topology based persistent identification mechanism generates ambiguity problem that usually stems from topology splitting and topology merging. Solving the ambiguity problem needs a complex method which is a combination of topology and geometry. Topology is used to assign the basic name to the entities. And geometry is used for the ambiguity solving between the entities. In the macro parametrics approach of iCAD lab of ...
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Interactive simulators that simulate mechanical systems are being developed for the purpose of performance evaluation of product design, replacement of physical training, and entertainment game. Use of flight simulator is increasing to... more
Interactive simulators that simulate mechanical systems are being developed for the purpose of performance evaluation of product design, replacement of physical training, and entertainment game. Use of flight simulator is increasing to reduce risk and cost of physical training, and we need virtual environment which covers large area terrain. We need a method that can reduce development cost and construction time of virtual environment that simulate the real environment. There have been attempts to link GIS or remote sensing field with virtual reality. This paper examines a method that helps to construct virtual environment, and attempts to link geographic information with virtual reality. A construction method of virtual environment based on digital map and satellite image has been studied.
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For large tokamak devices it is of interest to achieve a low external voltage startup scenarios since the maximum electric field which can be applied for ionization and plasma current ramp-up is limited. Therefore an additional heating... more
For large tokamak devices it is of interest to achieve a low external voltage startup scenarios since the maximum electric field which can be applied for ionization and plasma current ramp-up is limited. Therefore an additional heating such as ECRH may be necessary to give a reliable start-up condition. ECRH can ensure prompt breakdown in a wide range of pressure