• Proceedings of the KSR Conference
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• 2008.06a
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• pp.913-918
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• 2008

When developing railway vehicle system, investigation of the dynamical stability is essential as a virtual prototyping process. Not only the verification using the commercial analysis tools, systematic analysis using customized tools is also necessary, because these can give other points of view in stability, which is sometimes unable to evaluate in the former one. As a solver platform for customization, it is important to derive basic theory about flexible bodies and build flexible structure, which enables easy module insertion of user-created functions. In the paper, a flexible dynamic analysis system is developed, using absolute cartesian coordinate, modal coordinate and absolute nodal coordinate. Each coordinate system is verified by respective examples for every system. This solver system will play an important role for building the basic platform for analysis system, keeping pace with the concurrent development of the modules, such as wheel-contact force, constraints and user-defined force modules. Using the information from the analysis, the evaluation of the dynamic behavior of the train and its stability analysis will be available.

• Korean Journal of Computational Design and Engineering
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• v.8 no.3
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• pp.157-166
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• 2003

In this paper, we explain the DMU (digital mockup) system based on the PDM system. Most manufacturing companies are trying to develop a competitive product by increasing the quality, shortening time to market (TIM) and reducing the cost of a product. Some technologies such as SE (System Engineering), CE (Concurrent Engineering), QFD (Quality Function Development), CI (Cost Innovation) and some systems such as CAD (Computer-Aided Design), CAE (Computer-Aided Engineering), CAM (Computer-Aided Manufacturing), PDM (Product Data Management) and visualization system are adopted for these purposes. Specially, DMU system utilizes a visualization system that shows the 3D shape of a product on the computer and it gives a quick intuition to a person whether he/she is an engineer or not. It also can induce the effects of CE and QFD. SO, 0 company is developing a DMU system integrating CAD, visualization and PDM system. The main feature of the developed DMU system is that it is entirely integrated with PDM system, which means that the 3D shape of any part or assembly can be retrieved through PDM system. The DMU system will change the development process, which will increase the competitiveness of a developed product.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.9
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• pp.297-306
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• 2015

Cloud computing has been increasingly used in various fields due to its flexibility, scalability, cost effectiveness, etc. Recently, many scientific communities have been attempting to use cloud computing as a way to deal with difficulties in constructing and operating a research infrastructure. Especially, since they need various collaborations based on networking, such as sharing experimental data, redistributing experimental results, and so forth, cloud computing environment that supports high performance networking is required for scientific communities. To address these issues, we propose RealLab, a high performance cloud platform for collaborative research that provides virtual experimental research environment and data sharing infrastructure over KREONET/GLORIAD. Additionally, we describe some RealLab use cases for showing the swift creation of experimental environment and explain how massive experimental data can be transferred and shared among the community members.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.231-236
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• 2008

This paper proposes a cost-efficient and flexible FPGA-based logic circuit emulation platform. By improving the performance and adding more features, this new platform is an enhanced version of our LAPG. It consists of an FPGA-based hardware engine and software element to drive the emulation and monitor the results. It also provides an interactive verification environment which uses an efficient communication protocol through a bi-directional serial link between the host and the FPGA board. The experimental results show that this new approach saves $55%{\sim}99%$ of communication overhead compared with other methods. According to the test results, the new LAPG is more area efficient in complex circuits with many I/O ports.

• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.90-93
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• 2015

The fibula free flap has now become the most reliable and frequently used option for mandible reconstruction. Recently, three dimensional images and printing technologies are applied to mandibular reconstruction. We introduce our recent experience of mandibular reconstruction using three dimensionally planned fibula free flap in a patient with gunshot injury. The defect was virtually reconstructed with three-dimensional image. Because bone fragments are dislocated from original position, relocation was necessary. Fragments are virtually relocated to original position using mirror image of unaffected right side of the mandible. A medical rapid prototyping (MRP) model and cutting guide was made with 3D printer. Titanium reconstruction plate was adapted to the MRP model manually. 7 cm-sized fibula bone flap was designed on left lower leg. After dissection, proximal and distal margin of fibula flap was osteotomized by using three dimensional cutting guide. Segmentation was also done as planned. The fibula bone flap was attached to the inner side of the prebent reconstruction plate and fixed with screws. Postoperative evaluation was done by comparison between preoperative planning and surgical outcome. Although dislocated condyle is still not in ideal position, we can see that reconstruction was done as planned.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.5
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• pp.542-546
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• 2008

Recently dual-port SDRAM (DPSDRAM) architecture tailored for dual-processor based mobile embedded systems has been announced where a single memory chip plays the role of the local memories and the shared memory for both processors. In order to maintain memory consistency from simultaneous accesses of both ports, every access to the shared memory should be protected by a synchronization mechanism, which can result in substantial access latency. We propose two optimization techniques by exploiting the communication patterns of target applications: lock-priority scheme and static-copy scheme. Further, by dividing the shared bank into multiple blocks, we allow simultaneous accesses to different blocks thus achieve considerable performance gain. Experiments on a virtual prototyping system show a promising result - we could achieve about 20-50% performance gain compared to the base DPSDRAM architecture.

• Korean Journal of Computational Design and Engineering
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• v.10 no.6
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• pp.444-454
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• 2005

Recently, the requirements of multi-resolution models of a solid model, which represent an object at multiple levels of feature detail, are increasing for engineering tasks such as analysis, network-based collaborative design, and virtual prototyping and manufacturing. The research on this area has focused on several topics: topological frameworks for representing multi-resolution solid models, criteria for the level of detail (LOD), and generation of valid models after rearrangement of features. As a solution to the feature rearrangement problem, the new concept of the effective zone of a feature is introduced in the former part of the paper. In this paper, we propose a feature-based non-manifold modeling system to provide multi-resolution models of a feature-based solid or non-manifold model on the basis of the effective feature zones. To facilitate the implementation, we introduce the class of the multi-resolution feature whose attributes contain all necessary information to build a multi-resolution solid model and extract LOD models from it. In addition, two methods are introduced to accelerate the extraction of LOD models from the multi-resolution modeling database: the one is using an NMT model, known as a merged set, to represent multi-resolution models, and the other is storing differences between adjacent LOD models to accelerate the transition to the other LOD. We also suggest the volume of the feature, regardless of feature type, as a criterion for the LOD. This criterion can be used in a wide range of applications, since there is no distinction between additive and subtractive features unlike the previous method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.744-751
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• 2008

Ubiquitous computing is a new paradigm of telecommunication technology and is embedded with advanced computing technology to process a large amount of data in a normal environment. Generally, ail equipment is embedded with sensors and operating devices to interaction with communication functions. That is why ubiquitous computing must be able to access any devices anywhere at anytime in order to perform appropriate functions. Unfortunately, however, it is difficult to make an optimized design for applications which can effectively interaction with various functions in distributed environment like ubiquitous computing. Therefore, this paper is aimed at deploying interface with server nodules and virtual prototyping by utilizing LabVIEW and embedded application software with additional network function. In addition, given information about sensors collected from context-awareness and location-awareness, it will suggest the ideal ubiquitous application based on context-awareness and apply the advanced application to device control and monitoring through context awareness of lab.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.149-159
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• 2008

In this paper, we propose a blind watermarking algorithm of 3d mesh model using spherical parameterization. Spherical parameterization is a useful method which is applicable to 3D data processing. Especially, orthogonal coordinate can not analyse the feature of the vertex coordination of the 3D mesh model, but this is possible to analyse and process. In this paper, the centroid center of the 3D model was set to the origin of the spherical coordinate, the orthogonal coordinate system was transformed to the spherical coordinate system, and then the spherical parameterization was applied. The watermark was embedded via addition/modification of the vertex after the feature analysis of the geometrical information and topological information. This algorithm is robust against to the typical geometrical attacks such as translation, scaling and rotation. It is also robust to the mesh reordering, file format change, mesh simplification, and smoothing. In this case, the this algorithm can extract the watermark information about $90{\sim}98%$ from the attacked model. This means it can be applicable to the game, virtual reality and rapid prototyping fields.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.297-302
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• 2008

In case of display a lot of information from mobile devices, those systems are being developed that display the information from mobile devices on remote devices such as TV using the mobile devices as remote controllers because it is difficult to display a lot of information on mobile devices due to their limited bandwidth and small screen sizes. A lot of cost is required to design and develop interfaces for these systems corresponding to each of remote display devices. In this paper, a mobile environment based remote display system for displays at real times is proposed for continuous monitoring of status data for unique 'Mote IDs'. Also, remote data are collected and monitored through sensor network devices such as ZigbeX by applying status perception based remote displays at real times through processing ubiquitous computing environment data, and remote display applications at real times are implemented through PDA wireless mobiles. The system proposed in this paper consists of a PDA for remote display and control, mote embedded applications programming for data collections and radio frequency, server modules to analyze and process collected data and virtual prototyping for monitoring and controls by virtual machines. The result of the implementations indicates that this system not only provides a good mobility from a human oriented viewpoint and a good usability of accesses to information but also transmits data efficiently.