• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.27.1-27.1
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• 2011

This study is about the ionospheric variation on the Korean Peninsula using GPS TEC data from Daejeon IGS GPS site. It has accumulated the 11 years GPS data from 2000. In this work, the hourly and daily averaged TEC data are used. Data period covers a full solar cycle from 2000 to 2010 (11 years) which the total observed days are 98%. The mean TEC data shows the annual/semiannual variation, solar cycle and 27 days. GPS TEC has a good correlation with solar F10.7 index. We also compare with planetary Kp and AE indices. The maximum of the daily mean GPS TEC is around 50 TECU at 2000 and that value of 2009 is near 10 TECU. we confirms that the GPS TEC is a good indicator for ionospheric variation for the mid-latitudinal region to understand the ionospheric climatology over Korea Peninsula.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.338-341
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• 2008

Galvannealed Sheet Steel, which is being widely used in the automotive industry, is made by reheat after dip zinc galvanizing process. By this, A Fe-Zn alloy is created which enhance anticorrosive property and weldability. This paper describes basic design for 2000kW induction heating inverter system for galvannealling process and test result of 250kW inverter module which is used in parallel to form 2000kW inverter system.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.572-575
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• 2003

There is two System for IMT-2000 Service. one is FDD(Frequency Division Duplex), the other is TDD(Time Division Duplex) system. At the 1920MHz, they have common boundary in IMT-2000 frequency allocation of Korea. In this paper, The amount of Interference From TDD MS(Mobile Station) and BS(Base Station) to FDD BS is Analyzed for Investigation on capacity variation of FDD service by frequency separation. the result and methodology in this paper will be used basically for calculating the guard-band between FDD and TDD service in the future

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.852-862
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• 2017

In this work a Discrete Cosine Transform (DCT)-based feature dimensionality reduced approach for fingerprint matching is proposed. The DCT is applied on a small region around the core point of fingerprint image. The performance of our proposed method is evaluated on a small database of Bologna University and two large databases of FVC2000. A dimensionally reduced feature vector is formed using only approximately 19%, 7%, and 6% DCT coefficients for the three databases from Bologna University and FVC2000, respectively. We compared the results of our proposed method with the discrete wavelet transform (DWT) method, the rotated wavelet filters (RWFs) method, and a combination of DWT+RWF and DWT+(HL+LH) subbands of RWF. The proposed method reduces the false acceptance rate from approximately 18% to 4% on DB1 (Database of Bologna University), approximately 29% to 16% on DB2 (FVC2000), and approximately 26% to 17% on DB3 (FVC2000) over the DWT based feature extraction method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.54
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• pp.97-110
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• 2000

As more and more companies pursue ISO 9000 certification, one of the most misconceptions about ISO 9000 is that registration is necessary only for business. ISO 9000 is being driven by commercial requirements, not legal fiat. This registration can be used as evidence of compliance to the ISO 9000 to satisfy specific customer requirements. The primary objective of this research is to provide the efficient implementation process of ISO 9000 certification on the basis of total quality management concerning with ISO/CDl 9001:2000, ISO/CDl 9004:2000 and ISO/CD2 9001:2000. Based on the result of first paper in May 1999, this study has been conducted using the data collected from 312 manufacturing companies which registered ISO 9000 certification. This analysis can be applied to Korean small and medium industrial companies in establishing and maintaining the development of qualify systems. The companies should be able to benefit if they make continuous effort to improve the quality activities based on the factors suggested in this paper.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.41-52
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• 2009

In Motion JPEG2000 encoding, huge bandwidth requirement of data memory access is the bottleneck in required system performance. For the alleviation of this bandwidth requirement, a new embedded compression(EC) algorithm with a little bit of image quality drop is devised. For both random accessibility and low latency, very simple and efficient entropy coding algorithm is proposed. We achieved significant memory bandwidth reductions (about 53${\sim}$81%) and reduced code-block memory to about half size through proposed multi-mode algorithms, without requiring any modification in JPEG2000 standard algorithm.

• Journal of IKEEE
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• v.3 no.2 s.5
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• pp.196-203
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• 1999

In this paper, the DS(direct sequence)-CDMA and MC(multi-carrier)-CDMA, which are being researched recently as a synchronous IMT-2000 scheme for next-generation mobile multimedia communications, are studied in terms of BER(bit error rate) performance. The BER performance of MC-CDMA with EGB, MRC, and improved MMSEC detection scheme are analyzed and compared to that of conventional DS-CDMA adopting RAKE receiver through the computer simulations under the environments of synchronous IMT-2000 transmission channel. Not only single user case but also multiuser case is considered in the given system. As a result, it is shown that MC-CDMA with MMSEC detection outperforms all other schemes improved the $E_b/N_o$ by about 5 [dB] and 6 [dB] when the BER is $2{\times}10^{-3}$, for the indoor/outdoor fading channel and synchronous IMT-2000 transmission channel, respectively. Also in the multiuser case, MC-CDMA with MMSEC detection scheme exhibits better performance than all the other schemes.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.9-15
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• 2007

In this paper, we propose an efficient method for Processing DWT (Discrete Wavelet Transform) on GPU (Graphics Processing Unit). Since the DWT and EBCOT (embedded block coding with optimized truncation) are the most complicated submodules in JPEG2000, we design a high-performance processing framework for performing DWT using the fragment shader of GPU based on the render-to-texture (RTT) architecture. Experimental results show that the performance increases significantly, in which DWT running on modern GPU is more than 10 times faster than on modern CPU. Furthermore, by replacing the DWT part of Jasper which is the JPEG2000 reference software, the overall processing is 2$\sim$16 times faster than the original JasPer. The GPU-driven render-to-texture architecture proposed in this paper can be used in the general image and computer vision processing for high-speed processing.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.59-65
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• 2008

In security layer in the CDMA2000 1x EV-DO, a standard - C.S0024-a v2.0 is being accomplished under the project of 3GPP2(3rd Generation Partnership Project2). Therefore, a security device is needed to implement the security layer which is defined on the standard document for data transfer security between AT(Access Terminal) and AN(Access Network) on CDMA2000 1x EV-DO environment. This paper realizes the security layer system that can make safe and fast transfer of data between AT and AN. It could be applied to various platform environments by designing and implementing the Security Layer in the CDMA2000 1x EV-DO Security Layer to which applies C.S0024-A v2.0 of 3GPP2.

• Journal of the Korean Society of Costume
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• v.60 no.2
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• pp.1-19
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• 2010

The purpose of this research is to examine the rise of hip-hop culture and its characteristics which have been established as a part of popular culture amid other subcultures and to examine the overall concept of hip-hop fashion which has been developing since its rise in the 1970s and particularly to examine the hip-hop after the turn of the new century when it has gone through several iterations and changes while simultaneously accommodating different trends and reflecting a highly diverse larger culture. The research methodology is a literature-based research that uses classification and analysis based on the preceding research including related books and dissertations and, considering that this research focuses on the characteristics of hip-hop from the 2000s to the present, mainstream news media such as newspapers and magazines around New York images of famous hip-hop culture & stores websites were used in this research. The most characteristic hip-hop fashions since the 2000s examined by this research comprise prep-hop, slim formal suits, skurban, hip-hop Goth, and hip-hop Tatto. First, prep-hop is a mixed match of a preppy look with latest hip-hop sentiments and hip-hop styles. Second, there are slim formal suits that reflect a change of trends that strongly show changes of hip-hop fashion consumers who have been following sports stars' fashions. Third, skurban is a hip-hop fashion combined with the look of skaters. Fourth, hip-hop Goth is what emphasizes strong Goth images such as grunge, skull, and devil in hip-hop fashions based on vintage fashion. Fifth, hip-hop Tatto style designs have appeared in diverse items such as trendy clothes and accessories that were most popular since the 2000s. Hip-hop fashion since the 2000s up to the present is beginning to be integrated with diverse other cultures and its most prominent characteristics is a change into slimmer silhouette.