• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.55-63
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• 1991

This paper deals with development of a Computer Aided Process Planning System based on knowledge base in addition to database for injection mold as a part of Computer Integrated Manufacturing System for injection mold manufacture. The prposed system consists of four modules such as manufacturing feature code generation module machine tool selection and sequencing module, operation and cutting tool selection mudule and standard time estimation module. The system is programmed by using Turbo Pascal on the IBM-PC/AT. The performance of the system is evaluated by using real problems and the test results indicate that the proposed system is a practical and efficient system.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.74-79
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• 2000

Integrating a 3D solid modeler with a general purpose FEM code, an automatic nonlinear analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated by the bucketing method, and ten-noded quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. The complete finite element(FE) model generated, and a stress analysis is performed. In this system, burden to analysts fur introducing 3D cracks to the FE model as well as fur estimating their fracture mechanics parameters can be dramatically reduced. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.55-62
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• 2005

In this paper, a CAB/CAE integrated optimal design system is developed, in which design and analysis process is automated using CAD/CAE softwares, for a complicated model for which parametric modeling provided by CAD software is not possible. CAD modeling process is automated by using UG/OPEN API function and UG/Knowledge Fusion provided by Unigraphics. The generated model is transferred to the analysis code ANSYS in parasolid format. Visual DOC software is used for optimization. The system is developed for PLS(Plasma Lighting System), which is a next generation illumination system that is used to illuminate stadium or outdoor advertizing panel. The PLS system consists of more then 20 components, which requires a lot of human efforts in modeling and analysis. The analysis for PLS includes static load, wind load and impact load analysis. As a result of analysis, it is found that the most critical component is a tilt assembly, which links lower & upper body assembly. For more reliable analysis, experiment is conducted using MTS and compared with the Finite element analysis result. The objective in the optimization is to minimize the material volume under allowable stresses. The design variables are three parameters in the tilt assembly that are chosen to be the most sensitive in stress values of twelve parameters. Gradient based method and RSM(Response Surface Method) are used for the algorithm and the results are compared. As a result of optimization, the maximum stress is reduced by 57%.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.704-716
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• 2005

Assembling new software systems from Prepared components is an attractive alternative to traditional software development method to reduce development cost and schedule dramatically. However, if separately developed components are tested, integrated and verified with unreasonable effort and high cost, it would not be an effective way to software development. Components are not distributed in the shape of white-box source code so that should be hard to validate and test in new application environment. For solving this problem, built-in tester components are suggested to check the contract-compliance of their server components. If components have various and complex function, built-in tester should be heavy and unflexible to test in composition of components. This paper suggests enhancing automated wrapper technique which substitutes with built-in tester components and shows the usability of the wrapper by design and implementation. Component testing in this way reduces the cost and effort associated with preparation of component testing and makes the various test experiments in components assembly.

• Journal of Digital Convergence
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• v.10 no.1
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• pp.349-355
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• 2012

Today, the computing environments is very complex, so researches that endow a system with the self-healing's ability that recognizes problem arising in a target system are being an important issues. However, the existing methodology, the goal for the new requirements for self-healing system developers to model and analyze the constraints that must be greater efforts. Therefore, in this paper are aware of problems detected by the system to solve the problem is the analysis of goal-based scenarios. In addition, there is a pre and post applying a strategy to be dynamically reconfigured to show you how to self-healing. These proposed new requirements for methodology, self-healing reduces the load on the developer's analysis.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.445-450
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• 2004

This paper describes an optimal design system for multi-disciplinary structural design. An automatic finite element (FE) mesh generation technique, which is based on the fuzzy knowledge processing and computational geometry technique, is incorporated into the system, together with a commercial FE analysis code and a commercial solid modelers. An optimum design solution or satisfactory solutions are then automatically searched using the genetic algorithms modified for real search space, together with the automated FE analysis system. With an aid of genetic algorithms, the present design system allows us to effectively obtain a multi-dimensional solutions. The developed system is successfully applied to the shape design of a micro accelerometer based on a tunnel current concept.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.91-98
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• 2009

The "3+3 Process" for safety critical software for nuclear power plants' I&C (Instrumentation and Control system) has been developed in this work. The main idea of the "3+3 Process" is both to simplify the software development and safety analysis in three steps to fulfill the requirements of a software safety plan [1]. The "3-Step" software development process consists of formal modeling and simulation, automated code generation and coverage analysis between the model and the generated source codes. The "3-Step" safety analysis consists of HAZOP (hazard and operability analysis), FTA (fault tree analysis), and DV (design validation). Put together, these steps are called the "3+3 Process". This scheme of development and safety analysis minimizes the V&V work while increasing the safety and reliability of the software product. For assessment of this process, validation has been done through prototyping of the SDS (safety shut-down system) #1 for PHWR (Pressurized Heavy Water Reactor).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.652-660
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• 2008

Applications running under embedded systems require various device drivers designed for different types and versions of the OS to manage resources effectively. In this paper, an automated device driver generator system which can generate the device drivers to be used in newer versions the target OS is proposed. In the proposed system, the structures of device drivers of specific OS are designed in the templates and stored in a library, and the target device drivers are generated by adding codes to the stored templates. Once device drivers are generated, they are registered into the kernel. The experimental results show that data transfer time has been slightly increased when compared against manually created drivers for TFT-LCD driver, USB interface keyboard/mouse driver, and AC'97 controller drivers. The code size for the generated drivers after compilation has also been increased slightly when compared with manually designed device drivers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.63-73
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• 2008

RFID(Radio Frequency IDentification) system is an automated identification system that basically consists of tags and readers and Back-End-Databases. Tags and Readers communicate with each other by RF signal. As a reader can identify many tags in contactless manner using RF signal, RFID system is expected to do a new technology to replace a bar-code system in supply-chain management and payment system and access control and medical record and so on. However, RFID system creates new threats to the security of systems and privacy of individuals, Because tags and readers communicate with each other in insecure channel using RF signal. So many people are trying to study various manners to solve these problems against attacks, But they are difficult to apply to RFID system based on EPCglobal UHF Class-1 Generation-2 tags. Recently, Chien and Chen proposed a mutual Authentication protocol for RFID conforming to EPCglobal UHF Class-1 Generation-2 tags. we discover vulnerabilities of security and inefficiency about their protocol. Therefore, We analyze vulnerabilities of their protocol and propose an efficient mutual authentication protocol that improves security and efficiency.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.18-27
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• 2005

Airfoils with improved longitudinal static stability were designed for a WIG craft through aerodynamic design optimization. The response surface method is coupled with NURBS-based shape functions and Navier-Stokes flow analysis. The procedure runs in the network-distributed design framework of commercial-code based automated design capability to enhance computational efficiency and robustness.Lift maximization design maintaining similar static margin to a DHMTU airfoil successfully produced a new airfoil shape characterized by pronounced front-loading and the well-known reflexed aft-camber line. Another airfoil design of lower variation in pitching moment during take-off showed weakened front-loaded characteristics and hence decreased lift slightly. Investigations using the present design methodology on an existing optimization result based on potential flow analysis and NACA-type geometry generation demonstrated significance of carrying various geometry generations and more realistic flow analysis with optimization.