• Title/Summary/Keyword: Search Band

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Development of 2.4GHz ISM Band Wireless Communication Platform based on Embedded Linux (임베디드 리눅스 기반의 2.4GHz ISM 밴드 무선 통신 플랫폼 개발)

  • Ohm, Woo-Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.175-181
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    • 2015
  • In this paper, we develop a 2.4GHz ISM band wireless communication platform prototype based on embedded linux which support can be u-Hospital service. The developed system is available connecting between ARM920T processor board and FPGA board and linking IEEE 802.11b PHY board, AD/DA(10Bit) and RF(2.4GHz) board for wireless access. It is also can be utilized for the embedded system design with IEEE 802.11b/g Access Point(Option: IEEE 802.11a/b/g) test due to the Embedded Linux. Also, the developed system is possible to test and verify the radio access technology, Modem(OFDM etc) and IP(Intellectual Property) circuit. And make the most use of the system, we search for a expansion to that home and mobile healthcare, wellness service application.

Improvement Mechanism of Security Monitoring and Control Model Using Multiple Search Engines (다중 검색엔진을 활용한 보안관제 모델 개선방안)

  • Lee, Je-Kook;Jo, In-June
    • The Journal of the Korea Contents Association
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    • v.21 no.1
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    • pp.284-291
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    • 2021
  • As the current security monitoring system is operated as a passive system only for response after an attacker's attack, it is common to respond to intrusion incidents after an attack occurs. In particular, when new assets are added and actual services are performed, there is a limit to vulnerability testing and pre-defense from the point of view of an actual hacker. In this paper, a new security monitoring model has been proposed that uses multiple hacking-related search engines to add proactive vulnerability response functions of protected assets. In other words, using multiple search engines with general purpose or special purpose, special vulnerabilities of the assets to be protected are checked in advance, and the vulnerabilities of the assets that have appeared as a result of the check are removed in advance. In addition, the function of pre-checking the objective attack vulnerabilities of the protected assets recognized from the point of view of the actual hacker, and the function of discovering and removing a wide range of system-related vulnerabilities located in the IP band in advance were additionally presented.

Speaker Verification System with Hybrid Model Improved by Adapted Continuous Wavelet Transform

  • Kim, Hyoungsoo;Yang, Sung-il;Younghun Kwon;Kyungjoon Cha
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.3E
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    • pp.30-36
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    • 1999
  • In this paper, we develop a hybrid speaker recognition system [1] enhanced by pre-recognizer and post-recognizer. The pre-recognizer consists of general speech recognition systems and the post-recognizer is a pitch detection system using adapted continuous wavelet transform (ACWT) to improve the performance of the hybrid speaker recognition system. Two schemes to design ACWT is considered. One is the scheme to search basis library covering the whole band of speech fundamental frequency (speech pitch). The other is the scheme to determine which one is the best basis. Information cost functional is used for the criterion for the latter. ACWT is robust enough to classify the pitch of speech very well, even though the speech signal is badly damaged by environmental noises.

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Identification of MgII Absorbers in the Quasar Lines of Sight

  • Shim, Hyunjin
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.75.3-75.3
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    • 2015
  • Large area infrared surveys are often accompanied with follow-up optical spectroscopic surveys that has a significant legacy value even for other areas of research. Using these spectral database, we have performed a search for MgII absorption lines in the optical spectrum of background quasar. Over the ~4deg2 of AKARI North Ecliptic Pole survey field and Spitzer First Look Survey field, 18 and 16 MgII absorber systems are identified respectively. The redshift range for the background quasars was 1.0<$z_{qso}$<3.4, while the redshift range for the absorber was 0.6<$z_{abs}$<1.6. Galaxies responsible for MgII absorptions are identified in the deep optical images (CFHT r-band), yet the identification still remains ambiguous for 60% of the systems due to the limited image depth and the source crowdedness. The impact parameter ranges 20-60kpc, and the rest-frame equivalent width of MgII absorption ranges $0.7-4{\AA}$. The most critical part in the identification of MgII absorber galaxies is the existence of deep optical images in addition to the high S/N quasar spectrum with R>3000.

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A Comparative Analysis on the Current Housing Unit Plans of Korea and China (${\cdot}$중 현대 집합주거 단위평면 비교연구)

  • Jung Byung-Moon;Kim Hyeon-Ji;Lee Sang-Hong
    • Journal of the Korean housing association
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    • v.16 no.6
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    • pp.65-72
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    • 2005
  • The purpose of this study is to get preeminent data from comparative analysis of multi-family housing unit plans between Korea and China nowadays. Even though Korea and China belong to common cultured band in Asia, there are many different Housing aspects and unit plans. Through this study we want to grasp the characteristics of both nation's apartment unit plans and to contribute for advance into the China apartment market. Analysis target is constructing and lotting out apartment at South Korea and China in 2004, and the space syntax model is used as an analysis tool. First, analyze kind, number and special quality of each room by use area, and second, analyze area and scale of the rooms. Through the integration analysis we know the grade of rank and centrality of each rooms, and search difference of South Korean and Chinese apartment.

The Globular Cluster NGC 6273: Another Candidate for the Milky Way Building Blocks

  • Lim, Dongwook;Han, Sang-Il;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.40.2-40.2
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    • 2015
  • In our recent investigation (Lim et al. 2015), we have shown that the combination of narrow-band Ca photometry and low-resolution spectroscopy can effectively search for globular clusters (GCs) with supernovae (SNe) enrichments. We apply this technique to the metal-poor bulge GC NGC 6273 and find two distinct subpopulations having different light and heavy element abundances. Our result suggests that NGC 6273 was massive enough to retain SNe ejecta, which would place this cluster in the growing group of GCs with Galactic building block characteristics, such as ${\omega}$ Centauri and M22.

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A Design of RS Decoder for MB-OFDM UWB (MB-OFDM UWB 를 위한 RS 복호기 설계)

  • Choi, Sung-Woo;Shin, Cheol-Ho;Choi, Sang-Sung
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.131-136
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    • 2005
  • UWB is the most spotlighted wireless technology that transmits data at very high rates using low power over a wide spectrum of frequency band. UWB technology makes it possible to transmit data at rate over 100Mbps within 10 meters. To preserve important header information, MB-OFDM UWB adopts Reed-Solomon(23,17) code. In receiver, RS decoder needs high speed and low latency using efficient hardware. In this paper, we suggest the architecture of RS decoder for MB-OFDM UWB. We adopts Modified-Euclidean algorithm for key equation solver block which is most complex in area. We suggest pipelined processing cell for this block and show the detailed architecture of syndrome, Chien search and Forney algorithm block. At last, we show the hardware implementation results of RS decoder for ASIC implementation.

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Architecture of RS decoder for MB-OFDM UWB

  • Choi, Sung-Woo;Choi, Sang-Sung;Lee, Han-Ho
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.195-198
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    • 2005
  • UWB is the most spotlighted wireless technology that transmits data at very high rates using low power over a wide spectrum of frequency band. UWB technology makes it possible to transmit data at rate over 100Mbps within 10 meters. To preserve important header information, MBOFDM UWB adopts Reed-Solomon(23,17) code. In receiver, RS decoder needs high speed and low latency using efficient hardware. In this paper, we suggest the architecture of RS decoder for MBOFDM UWB. We adopts Modified-Euclidean algorithm for key equation solver block which is most complex in area. We suggest pipelined processing cell for this block and show the detailed architecture of syndrome, Chien search and Forney algorithm block. At last, we show the hardware implementation results of RS decoder for ASIC implementation.

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A Study on the Concept of Topological Space shown Folding in Architecture (접힘 건축에 나타난 위상기하학적 공간 개념에 관한 연구)

  • 황태주
    • Korean Institute of Interior Design Journal
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    • v.13 no.3
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    • pp.69-75
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    • 2004
  • Since 1990s, several rising western architects have been moving their theoretical background from the modern paradigm to new science and philosophy. Architectural spaces are based on the philosophy and science of their own age and the architectural theories made by them. And specially, it seems that topological spaces are different to theoretical backgrounds from idealized spaces of modern architecture. From these backgrounds, this study was performed to search for the spacial relationship and characteristics shown in the recently folding architecture and the results of this study that starts this purpose are as follows. First, the architecture that introduced by the theory of topology has appeared as the circulation forms like as Mobius band or Klein bottle, and was made the space fused with structure pursuing liquid properties of matter. As follows, second, the concept of topological space made the division of traditional concept of floor, wall, ceiling disappeared and had built up the space by continual transformation. Third, about the relationship between two spaces in topological space, the two spaces were happened by transformation of these and they have always continuity and the same quality.

Search for new red phosphors under NUV/blue excitation - the stimulating future for solid state lighting

  • Vaidyanathan, Sivakumar;Jeon, Duk-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1350-1352
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    • 2008
  • Research on down conversion phosphor materials is the key for the development of solid state lighting (SSL). Especially finding alternative red phosphor for white LEDs based on blue or NUV LEDs are important research task. Under this view, we have synthesized a series of $Eu^{3+}$ substituted $La_2W_{2-x}Mo_xO_9$ (x = 0 ~ 2, insteps of 0.1) red phosphor and characterized by X-ray diffraction (XRD) and photoluminescence. XRD results reveal a phase transition from triclinic to cubic structure for $x\;{\geq}\;0$. All the compositions show broad charge transfer band due to charge transfer from oxygen to tungsten/molybdenum and red emission due to $Eu^{3+}$ ions. Select compositions show high red emission intensity compared to the commercial red phosphor under NUV/blue ray excitation. Hence, this candidate can be possible red emitting phosphors for white LEDs.

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