• Title/Summary/Keyword: Direct Detection

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Initial Timing Acquisition for Binary Phase-Shift Keying Direct Sequence Ultra-wideband Transmission

  • Kang, Kyu-Min;Choi, Sang-Sung
    • ETRI Journal
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    • v.30 no.4
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    • pp.495-505
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    • 2008
  • This paper presents a parallel processing searcher structure for the initial synchronization of a direct sequence ultra-wideband (DS-UWB) system, which is suitable for the digital implementation of baseband functionalities with a 1.32 Gsample/s chip rate analog-to-digital converter. An initial timing acquisition algorithm and a data demodulation method are also studied. The proposed searcher effectively acquires initial symbol and frame timing during the preamble transmission period. A hardware efficient receiver structure using 24 parallel digital correlators for binary phase-shift keying DS-UWB transmission is presented. The proposed correlator structure operating at 55 MHz is shared for correlation operations in a searcher, a channel estimator, and the demodulator of a RAKE receiver. We also present a pseudo-random noise sequence generated with a primitive polynomial, $1+x^2+x^5$, for packet detection, automatic gain control, and initial timing acquisition. Simulation results show that the performance of the proposed parallel processing searcher employing the presented pseudo-random noise sequence outperforms that employing a preamble sequence in the IEEE 802.15.3a DS-UWB proposal.

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DARK MATTER IN THE UNIVERSE : BRIEF REVIEW

  • Oh, Kap-Soo
    • Publications of The Korean Astronomical Society
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    • v.7 no.1
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    • pp.31-37
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    • 1992
  • Dark matter in various size of scales is reviewed briefly. The evidence of dark matter in dwarf spheroidal galaxies is still uncertain. However there is no doubt about the existence of dark matter in larger scales. Many proposed candidates for dark matter are still speculative. Several possibilities of direct detection of dark matter are proposed.

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AdaBoost-based Real-Time Face Detection & Tracking System (AdaBoost 기반의 실시간 고속 얼굴검출 및 추적시스템의 개발)

  • Kim, Jeong-Hyun;Kim, Jin-Young;Hong, Young-Jin;Kwon, Jang-Woo;Kang, Dong-Joong;Lho, Tae-Jung
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.11
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    • pp.1074-1081
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    • 2007
  • This paper presents a method for real-time face detection and tracking which combined Adaboost and Camshift algorithm. Adaboost algorithm is a method which selects an important feature called weak classifier among many possible image features by tuning weight of each feature from learning candidates. Even though excellent performance extracting the object, computing time of the algorithm is very high with window size of multi-scale to search image region. So direct application of the method is not easy for real-time tasks such as multi-task OS, robot, and mobile environment. But CAMshift method is an improvement of Mean-shift algorithm for the video streaming environment and track the interesting object at high speed based on hue value of the target region. The detection efficiency of the method is not good for environment of dynamic illumination. We propose a combined method of Adaboost and CAMshift to improve the computing speed with good face detection performance. The method was proved for real image sequences including single and more faces.

TaqMan Probe Real-Time PCR for Quantitative Detection of Mycoplasma during Manufacture of Biologics (생물의약품 제조공정에서 마이코플라스마 정량 검출을 위한 TaqMan Probe Real-Time PCR)

  • Lee, Jae Il;Kim, In Seop
    • KSBB Journal
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    • v.29 no.5
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    • pp.361-371
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    • 2014
  • Mycoplasma is well recognized as one of the most prevalent and serious microbial contaminants of biologic manufacturing processes. Conventional methods for mycoplasma testing, direct culture method and indirect indicator cell culture method, are lengthy, costly and less sensitive to noncultivable species. In this report, we describe a new TaqMan probe-based real-time PCR method for rapid and quantitative detection of mycoplasma contamination during manufacture of biologics. Universal mycoplasma primers were used for mycoplasma PCR and mycoplasma DNA was quantified by use of a specific TaqMan probe. Specificity, sensitivity, and robustness of the real-time PCR method was validated according to the European Pharmacopoeia. The validation results met required criteria to justify its use as a replacement for the culture method. The established real-time PCR assay was successfully applied to the detection of mycoplasma from human keratinocyte and mesenchymal stem cell as well as Vero cell lines artificially infected with mycoplasma. The overall results indicated that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of mycoplasma contamination during manufacture of biologics.

$F(ab)_2$-ELISA for the Detection of Nuclear Polyhedrosis Virus of Silk-worm, Bombyx mori L.

  • Sivaprasad, V.;Nataraju, B.;Baig, M.;Samson, M.V.;Datta, R.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.2
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    • pp.179-181
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    • 2003
  • $F(ab`)_2$-ELISA and direct antigen coating-ELISA (DAC-ELISA) were evaluated in the detection of purified Bombyx mori nuclear polyhedrosis virus (BmNPV) and nuclear polyhedrosis virus infection in silkworm larvae inoculated with BmNPV polyhedra. Although nanogram levels of BmNPV was detected in both DAC- and $F(ab`)_2$-ELISA, similar concentrations of antigen was detected in case of F(ab’)$_2$-ELISA even at higher dilution of antibody (up to 1 : 20 K). One hundred percent nuclear polyhedrosis infection was detected 6 hrs after inoculation in BmNPV infected silkworm larvae by $F(ab`)_2$-ELISA. On the other hand, detection of 100% infection was observed only three days after inoculation in DAC-ELISA. In this study, it was observed $F(ab`)_2$-ELISA was more sensitive than DAC-ELISA in the detection of purified BmNPV as well as nuclear polyhedrosis infection in silkworm larvae.

Two-stage ML-based Group Detection for Direct-sequence CDMA Systems

  • Buzzi, Stefano;Lops, Marco
    • Journal of Communications and Networks
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    • v.5 no.1
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    • pp.33-42
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    • 2003
  • In this paper a two-stage maximum-likelihood (ML) detection structure for group detection in DS/CDMA systems is presented. The first stage of the receiver is a linear filter, aimed at suppressing the effect of the unwanted (i.e., out-of-grout) users' signals, while the second stage is a non-linear block, implementing a ML detection rule on the set of desired users signals. As to the linear stage, we consider both the decorrelating and the minimum mean square error approaches. Interestingly, the proposed detection structure turns out to be a generalization of Varanasi's group detector, to which it reduces when the system is synchronous, the signatures are linerly independent and the first stage of the receiver is a decorrelator. The issue of blind adaptive receiver implementation is also considered, and implementations of the proposed receiver based on the LMS algorithm, the RLS algorithm and subspace-tracking algorithms are presented. These adaptive receivers do not rely on any knowledge on the out-of group users' signals, and are thus particularly suited for rejection of out-of-cell interference in the base station. Simulation results confirm that the proposed structure achieves very satisfactory performance in comparison with previously derived receivers, as well as that the proposed blind adaptive algorithms achieve satisfactory performance.

Application of Engineered Zinc Finger Proteins Immobilized on Paramagnetic Beads for Multiplexed Detection of Pathogenic DNA

  • Shim, Jiyoung;Williams, Langley;Kim, Dohyun;Ko, Kisung;Kim, Moon-Soo
    • Journal of Microbiology and Biotechnology
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    • v.31 no.9
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    • pp.1323-1329
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    • 2021
  • Micro-scale magnetic beads are widely used for isolation of proteins, DNA, and cells, leading to the development of in vitro diagnostics. Efficient isolation of target biomolecules is one of the keys to developing a simple and rapid point-of-care diagnostic. A zinc finger protein (ZFP) is a double-stranded (ds) DNA-binding domain, providing a useful scaffold for direct reading of the sequence information. Here, we utilized two engineered ZFPs (Stx2-268 and SEB-435) to detect the Shiga toxin (stx2) gene and the staphylococcal enterotoxin B (seb) gene present in foodborne pathogens, Escherichia coli O157 and Staphylococcus aureus, respectively. Engineered ZFPs are immobilized on a paramagnetic bead as a detection platform to efficiently isolate the target dsDNA-ZFP bound complex. The small paramagnetic beads provide a high surface area to volume ratio, allowing more ZFPs to be immobilized on the beads, which leads to increased target DNA detection. The fluorescence signal was measured upon ZFP binding to fluorophore-labeled target dsDNA. In this study, our system provided a detection limit of ≤ 60 fmol and demonstrated high specificity with multiplexing capability, suggesting a potential for development into a simple and reliable diagnostic for detecting multiple pathogens without target amplification.

Development of an Adaptive Feedback based Actuator Fault Detection and Tolerant Control Algorithms for Longitudinal Autonomous Driving (적응형 되먹임 기반 종방향 자율주행 구동기 고장 탐지 및 허용 제어 알고리즘 개발)

  • Oh, Kwangseok;Lee, Jongmin;Song, Taejun;Oh, Sechan;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.4
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    • pp.13-22
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    • 2020
  • This paper presents an adaptive feedback based actuator fault detection and tolerant control algorithms for longitudinal functional safety of autonomous driving. In order to ensure the functional safety of autonomous vehicles, fault detection and tolerant control algorithms are needed for sensors and actuators used for autonomous driving. In this study, adaptive feedback control algorithm to compute the longitudinal acceleration for autonomous driving has been developed based on relationship function using states. The relationship function has been designed using feedback gains and error states for adaptation rule design. The coefficients in the relationship function have been estimated using recursive least square with multiple forgetting factors. The MIT rule has been adopted to design the adaptation rule for feedback gains online. The stability analysis has been conducted based on Lyapunov direct method. The longitudinal acceleration computed by adaptive control algorithm has been compared to the actual acceleration for fault detection of actuators used for longitudinal autonomous driving.

Protein Microarrays and Their Applications

  • Lee, Bum-Hwan;Teruyuki Nagamune
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.2
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    • pp.69-75
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    • 2004
  • In recent years, the importance of proteomic works, such as protein expression, detection and identification, has grown in the fields of proteomic and diagnostic research. This is because complete genome sequences of humans, and other organisms, progress as cellular processing and controlling are performed by proteins as well as DNA or RNA. However, conventional I protein analyses are time-consuming; therefore, high throughput protein analysis methods, which allow fast, direct and quantitative detection, are needed. These are so-called protein microarrays or protein chips, which have been developed to fulfill the need for high-throughput protein analyses. Although protein arrays are still in their infancy, technical development in immobilizing proteins in their native conformation on arrays, and the development of more sensitive detection methods, will facilitate the rapid deployment of protein arrays as high-throughput protein assay tools in proteomics and diagnostics. This review summarizes the basic technologies that are needed in the fabrication of protein arrays and their recent applications.

Gravitational-wave detection - for the new age of astronomy (중력파 검출 - 새로운 천문학의 시대를 위하여)

  • Oh, John J.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.58.1-58.1
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    • 2015
  • Gravitational-wave has been predicted by Einstein's general relativity in 1916, but its direct detection has failed to date despite of the persistent efforts in the last fifty years in the ground-based gravitational wave detectors. In the centennial year of the birth of general relativity, 'advanced LIGO', one of the most promising Earth-based gravitational wave detectors, plans to start commissioning for the successful discovery of gravitational waves. In addition, a pathfinder satellite of eLISA project, a space-based GW antenna by European Space Agency (ESA), will be launched in the mid of this year. In this talk, we review the current status of gravitational waves detection experiments and discuss its scientific impacts and the possibility of opening the new age of astronomy.

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