• Title/Summary/Keyword: detection technique

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Development of Bioluminescence Immunoassay Using Photoprotein, Aequorin and Site-directed Immobilization

  • Shim, Yu-Nee;Rhee, In-sook
    • Bulletin of the Korean Chemical Society
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    • v.24 no.1
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    • pp.70-74
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    • 2003
  • The heterogeneous bioluminescence immunoassay for digoxin was developed using photoprotein, native aequorin as a label and the site-directed immobilization technique based on avidin/biotin interaction. Aequorin is a bioluminescence protein, originally isolated from the jellyfish Aequoria Victoria and an attractive label in analytical applications because of sensitive detection due to virtually no background bioluminescent signal. Digoxin is a cardioactive drug, and its therapeutic level in serum is at low concentration with very narrow therapeutic index. The aequorin-digoxigenin conjugates were synthesized by the N-hydroxysuccinimide ester method and characterized in terms of bioluminescent residual activity. The resulting dose-response curve shows that the detection limit is $1.0\;{\times}\;10^{-10}\;M$ and a dynamic range is three orders of magnitude, which was obtained by $1.0\;{times}\;10^{-10}\;M$ conjugate and 0.9 μg/mL anti-digoxin antibody. Three structurally similar molecules to digoxin were examined for their cross-reactivity. None of these three compounds showed any crossreactivity with digoxin antibody employed in this study. Standard amounts of digoxin corresponding to the therapeutic range were spiked into the each serum solution. Study of the serum matrix effect indicated that correlation coefficient shows good agreement between luminescence light intensity between in buffer and in serum.

Jamming Detection and Suppression Algorithm for an FMCW Radar Altimeter (FMCW 전파고도계의 재밍 탐지 및 회피 알고리즘)

  • Lee, Jae-Hwan;Jang, Jong-Hun;Roh, Jin-Eep;Yoo, Kyung-Ju;Choi, Jae-Hyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.2
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    • pp.147-155
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    • 2016
  • This paper presents a jamming detection and suppression algorithm of a frequency-modulated continuous-wave(FMCW) radar altimeter. The radar altimeter measures the noise level at the noise measuring period before the transmitting and receiving period and finds the number of sampled noise data over the jamming threshold for detecting the jamming. For a jamming suppression technique, we design the time domain jamming suppression, transmit/receive power control and frequency hopping methods. To assess more realistic operation, the radar altimeter was performed a field test. Through the field test, we verified the algorithms successfully.

Video Strip Mapping (VSM) and Patch Dynamics Analysis for Revegetation Monitoring of a Pipeline Route (송유관선로의 식생복원 감시를 위한 비디오선형지도화 및 patch dynamics분석)

  • Jung-Sup Um
    • Journal of the Korean Geographical Society
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    • v.33 no.3
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    • pp.435-446
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    • 1998
  • This Paper reports that a new remote sensing techlique focused on a narrow and long strip target (e.g. 15m wide and 100km long) has been specifically developed for pipeline ROW (Right-Of-Way) recovery monitoring. With video it was possible to isolate the maior vegetation communities of the narrow pipeline ROW with acceptable spatial precision by visual or quantitative methods. It was particuarly useful when used to assess a variety of spatial patch dynamics for ROW recovery through digital change-detection techniques in a GIS environment. The main conclusion of this paper is that VSM is a realistic operational technique for a pipeline ROW application. The results also indicate that VSM could be extensively used for other examples of linear thematic mapping.

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Detection of Explosive RDX using Parallel Plate Waveguide THz-TDS (평행판 도파관 THz 분광을 이용한 폭발물 RDX 검출)

  • Yoo, Byung Hwa;Chung, Dong Chul;Kang, Seung Beom;Kwak, Min Hwan;Kang, Gwang-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.12
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    • pp.1939-1943
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    • 2012
  • In this paper we presented the detection of the explosive material RDX using a parallel plate waveguide (PPWG) THz time domain spectroscopy (TDS). Normally the explosive materials have been characterized through identification of vibrational fingerprint spectra. Until now, most of all THz spectroscopic measurements have been made using pellet samples where disorder effects contribute to line broadening such that individual resonances merge into relatively broad absorption features. In order to avoid such disadvantages we used the technique of PPWG THz-TDS to achieve sensitive characterization of explosive material RDX. The PPWG THz-TDS used in this work well established ultrafast optoelectronic techniques to generate and detect sub-picosecond THz pulses. The explosive material was analyzed as powder layers in $112{\mu}m$ gap of metal PPWG. The thin later mass was estimated to be about $700{\mu}g$. Finally, we showed spectra of explosives from 0.2 to 2.4 THz measured using PPWG THz-TDS.

Structural damage identification of plates based on modal data using 2D discrete wavelet transform

  • Bagheri, A.;Ghodrati Amiri, G.;Khorasani, M.;Bakhshi, H.
    • Structural Engineering and Mechanics
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    • v.40 no.1
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    • pp.13-28
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    • 2011
  • An effective method for detection linear flaws in plate structures via two-dimensional discrete wavelet transform is proposed in this study. The proposed method was applied to a four-fixed supported rectangular plate containing damage with arbitrary length, depth and location. Numerical results identifying the damage location are compared with the actual results to demonstrate the effectiveness of the proposed method. Also, a wavelet-based method presented for de-noising of mode shape of plate. Finally, the performance of the proposed method for de-noising and damage identification was verified using experimental data. Comparison between the location detected by the proposed method, and the plate's actual damage location revealed that the methodology can be used as an accessible and effective technique for damage identification of actual plate structures.

An Algorithm for Computing Eigen Current of Forward Model of Mammography Geometry for EIT (매모그램 구조의 전기저항 영상법에서 정방향 모델의 고유전류 계산 알고리즘)

  • Choi, Myoung Hwan
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.91-96
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    • 2007
  • Electrical impedance tomography (EIT) is a technique for determining the electrical conductivity and permittivity distribution within the interior of a body from measurements made on its surface. One recent application area of the EIT is the detection of breast cancer by imaging the conductivity and permittivity distribution inside the breast. The present standard for breast cancer detection is X-ray mammography, and it is desirable that EIT and X-ray mammography use the same geometry. A forward model of a simplified mammography geometry for EIT imaging was proposed earlier. In this paper, we propose an iterative algorithm for computing the current pattern that will be applied to the electrodes. The current pattern applied to the electrodes influences the voltages measured on the electrodes. Since the measured voltage data is going to be used in the impedance imaging computation, it is desirable to apply currents that result in the largest possible voltage signal. We compute the eigenfunctions for a homogenous medium that will be applied as current patterns to the electrodes. The algorithm for the computation of the eigenfunctions is presented. The convergence of the algorithm is shown by computing the eigencurrent of the simplified mammography geometry.

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Magnetic Flux Leakage (MFL) based Defect Characterization of Steam Generator Tubes using Artificial Neural Networks

  • Daniel, Jackson;Abudhahir, A.;Paulin, J. Janet
    • Journal of Magnetics
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    • v.22 no.1
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    • pp.34-42
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    • 2017
  • Material defects in the Steam Generator Tubes (SGT) of sodium cooled fast breeder reactor (PFBR) can lead to leakage of water into sodium. The water and sodium reaction will lead to major accidents. Therefore, the examination of steam generator tubes for the early detection of defects is an important requirement for safety and economic considerations. In this work, the Magnetic Flux Leakage (MFL) based Non Destructive Testing (NDT) technique is used to perform the defect detection process. The rectangular notch defects on the outer surface of steam generator tubes are modeled using COMSOL multiphysics 4.3a software. The obtained MFL images are de-noised to improve the integrity of flaw related information. Grey Level Co-occurrence Matrix (GLCM) features are extracted from MFL images and taken as input parameter to train the neural network. A comparative study on characterization have been carried out using feed-forward back propagation (FFBP) and cascade-forward back propagation (CFBP) algorithms. The results of both algorithms are evaluated with Mean Square Error (MSE) as a prediction performance measure. The average percentage error for length, depth and width are also computed. The result shows that the feed-forward back propagation network model performs better in characterizing the defects.

Multiple damages detection in beam based approximate waveform capacity dimension

  • Yang, Zhibo;Chen, Xuefeng;Tian, Shaohua;He, Zhengjia
    • Structural Engineering and Mechanics
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    • v.41 no.5
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    • pp.663-673
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    • 2012
  • A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

Simple and Rapid Identification of Low Level Hepatitis B Virus DNA by the Nested Polymerase Chain Reaction

  • Jang, Jeong-Su;Lee, Kong-Joo
    • Archives of Pharmacal Research
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    • v.19 no.6
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    • pp.469-474
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    • 1996
  • A rapid and sensitive method has been developed to detect hepatitis B virus DNA (HBV) by nested polymerase chain reaction (PCR) technique with primers specific for the surface and core regions in capillary thermal cycler within 80 min. The lower limit for detection by present PCR method is $10^{-5}$ pg of recombinant HBV DNA which is equivalent to that determined by one round of PCR amplification and Southern blot hybridization analysis. When boiled HBV positive serum was serially diluted 10-fold, HBV DNA was successfully determined in $1{\mu}l-10^{-3}$ of serum. HBV DNA was detected by present method in 69 clinical samples including HBsAg positives and negatives by enzyme-linked immunosorbent assay (ELISA). When serum samples were amplified by nested PCR using surface and core region primers, HBV DNAs were detected in 37 of 69 samples (53.6%) and 18 of 69 samples (26.1%), respectively. These results can inform the infectious state of HBsAg positive pateints. A simple and rapid nested PCR protocol by using boiled serum as DNA template has been described for the clinical utility to determine HBV DNA in human serum.

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Live Cell Detection of Monoclonal Antibody Light and Heavy Chain mRNAs using Molecular Beacons (분자 비컨을 이용한 살아 있는 세포에서 단일클론항체 경쇄와 중쇄 mRNA 검출에 의한 세포주 선별방법)

  • Jeong, Seunga;Rhee, Won Jong
    • KSBB Journal
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    • v.31 no.1
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    • pp.33-39
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    • 2016
  • Developing the method for the selection of animal cell line producing therapeutic monoclonal antibody (mAb) is invaluable as its market is rapidly growing. Although the quality of produced mAb is as important as quantity, however there is no method developed for the selective screening of cell lines on the basis of both quantity and quality. From recent reports, the ratio of light and heavy chain mRNAs of mAb in the cell is a key parameter for the indication of product quality. Therefore, it is obvious that developing the novel method that can detect both light and heavy chain mRNAs in single live cell will provide unprecedented opportunities in bio-industry. Here, we have constructed oligonucleotide probes, molecular beacons for the detection of light or heavy chain mRNAs, respectively, in the live cells producing mAbs. Both beacons showed increased fluorescent intensity after transient transfection of plasmid expressing mAbs analyzed by fluorometer. Flow cytometric analysis clearly demonstrated that both molecular beacons can simultaneously detect the expression of light and heavy chain mRNAs of mAb in the same cell. The technique described in the thesis provides the new direction and concept for developing the method for the smart selection of cell lines producing recombinant proteins including therapeutic mAbs.