• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1377-1380
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• 2008

An irradiation test of a nuclear fuel rod having external and internal tube structure was planned for a performance. To establish fabrication process satisfying the requirements of irradiation test, micro-TIG welding system for fuel rods was developed, and preliminary welding experiments for optimizing process conditions of fuel rod was performed. Fuel rods with 15.9mm diameter and 0.57mm wall thickness of cladding tubes and end caps have been used and optimum conditions of endcap welding have been selected. In this experiment, the qualification test was performed by tensile tests, helium leak inspections, and metallography examinations to qualify the endcap welding procedure. The soundness of the welds quality of a dual cooled fuel rods has been confirmed by mechanical tests and microstructural examinations.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.543-547
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• 2005

Implementing a hardware cryptographic system is strongly required to assure high Qualify contents security. Not only because the many of the prevalent cryptographic algorithms require much computation time but also software implementations of cryptographic systems do not guarantee high performance, we need to design a hardware cryptographic system with a dedicated crypto-chip. This paper describes a case study of implementing a PCI cryptographic card which supports cryptographic algorithms such as 3DES, AES, SEED.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.965-972
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• 2005

We propose a new resource management scheme, Distributed Channel Allocation Protocol (DCAP), for multimedia Ad Hoc Wireless LANs (AWLANS). This scheme implements a Qualify-of-Service (QoS) providing distributed resource management on the Orthogonal Frequency Division Multiplexing-Code Division Multiple Access (OFDM-CDMA) channel architecture. According to the performance evaluation results for MPEG traffic sources, DCAP can be a good choice of resource management scheme for AWLANs supporting multimedia services on the Broadband Wireless Access(BWA)-type physical layer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.279-284
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• 2001

According to information communication business faces with competitions in a various spheres with the development of multimedia and information communication, the time when we have to make an effort to improve a qualify comes from an era when we devote ourselves to quantitative expansion. we will try to perform quality assessments of real-time interactive multimedia service, and so on - in this research and present criteria of new subjective quality assessments which is fit on Korea by analyzing examples of ITU-T and foreign countries and Korea.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.749-753
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• 2003

This paper presents an output voltage regulation system using PWM Buck-Boost AC-AC converter for power qualify improvement of custom power. This paper proposes dynamic modeling of the system for control object and in addition, a controller design example. Therefore, system state equation is derived whereby the transfer function could be obtained. The paper shows a regulation controller for tracking the output voltage to the reference under specific operating point. Finally, this paper shows validity and practical applicability of the proposed modelling and system design by experimental results.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.965-978
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• 2005

There are many defects that cause the schedule and qualify problems during software development. This paper designs the opportunity tree framer work that removes and manages the schedule and quality problems as well. For the similar projects, we can estimate defects and prepare to solve them by using domain expert knowledge and the opportunity tree framework which can greatly improve the software process. This research provides solution of schedule defect problem and detection of defect and its causes that happen on software development.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.506-509
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• 2005

This paper presents the improved burn-in method for the reliability of SRAM in Multi Chip Package (MCP). Semiconductor reliability is commonly improved by the burn-in process. Reliability Problem is very significant in the MCP which includes over two chips in a package because the failure of one SRAM chip has a large influence on the yield and quality of the other chips such as Flash Memory, DRAM, etc. Therefore the quality of SRAM must be guaranteed. To improve the qualify of SRAM, we applied the improved wafer level burn-in process using multi cell selection method in addition to the previously used methods and it is found to be effective in detecting particular failures. Finally, with the composition of some kinds of methods, we achieved the high quality of SRAM in MCP.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.202-205
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• 2002

This paper presents the reliability evaluation methods considering the momentary voltage quality in power distribution systems. The voltage qualify phenomena deal with this paper are sustained and momentary interruptions and voltage sags. Conventional evaluation indices and methods are summarized for the sustained interruptions, and the assessment methodologies of momentary interruptions and voltage sags are proposed. The evaluation methods are divided into the analytical method and Time Sequential Monte Carlo simulation. The proposed methods are tested using the modified RBTS (Roy Billinton Test System) form and historical reliability data of KEPCO system.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.345-354
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• 2002

In this paper, we introduce a new scanning method for MPEG-4 AVC based Fine Granular Scalable video coding that can significantly improve the subjective picture quality of a decoded scalable video. The proposed scanning method can guarantee the subjectively improved picture qualify of the decoded scalable video by encoding, transmitting and decoding the visually important region most-preferentially. From the simulation results, it has been found that the proposed scanning method can lead the FGS method to achieve significantly improved picture quality, especially on the region of interests.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.109-122
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• 1998

A Process Quality Information System (PQIS) for the CIM environment is presented. The system includes three subsystems which are qualify control, statistical analysis, and information management. As part of CIM, the PQIS was designed by using the ICAM Definition(IDEF) methodology. The Oracle-CDE was utilized as a graphic development tool which made the system more user friendly. PQIS operates on IBM or compatible PCs under MS-Windows and Oracle DBMS. The methodology developed in this research provides a foundation for the application of CIM subsystems.