• Title/Summary/Keyword: selective detection

Search Result 574, Processing Time 0.034 seconds

Determination of Mercury Ion in Contaminated Soil by Rhodamine B Hydrazide (형광화학센서를 이용한 용출기반 토양 수은 오염조사)

  • Kim, Kyungtae;Park, Junboum
    • Journal of Soil and Groundwater Environment
    • /
    • v.21 no.3
    • /
    • pp.1-5
    • /
    • 2016
  • Rhodamine B Hydrazide as a novel fluorescent and colorimetric probe exhibiting remarkably selective fluorescence enhancement toward Hg2+ ion over other 16 metal ions is herein introduced. The probe reacts with Hg2+ ion followed by its spirolactam ring-opening to give a remarkable enhancement of absorption maximum at 550 nm as well as an enhanced fluorescence intensity at 580 nm in aqueous media. Upon titration with Hg2+ ion in various concentration of 10~200 uM, we found that the probe shows a marked color change from colorless to pink, enabling naked-eye detection toward mercury ion. In addition, in the presence of Hg2+ ion, the probe gave rise to change from non-florescence to strong orange fluorescence (Off-On) with a good linearity of R2=0.97. This preliminary results demonstrate that the fluorescent chemosensor we herein introduced can open a new strategy for marked selective and sensitive detection of mercury ions in contaminated soil containing various metal ions.

Fast Cooperative Sensing with Low Overhead in Cognitive Radios

  • Dai, Zeyang;Liu, Jian;Li, Yunji;Long, Keping
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.8 no.1
    • /
    • pp.58-73
    • /
    • 2014
  • As is well known, cooperative sensing can significantly improve the sensing accuracy as compared to local sensing in cognitive radio networks (CRNs). However, a large number of cooperative secondary users (SUs) reporting their local detection results to the fusion center (FC) would cause much overhead, such as sensing delay and energy consumption. In this paper, we propose a fast cooperative sensing scheme, called double threshold fusion (DTF), to reduce the sensing overhead while satisfying a given sensing accuracy requirement. In DTF, FC respectively compares the number of successfully received local decisions and that of failed receptions with two different thresholds to make a final decision in each reporting sub-slot during a sensing process, where cooperative SUs sequentially report their local decisions in a selective fashion to reduce the reporting overhead. By jointly considering sequential detection and selective reporting techniques in DTF, the overhead of cooperative sensing can be significantly reduced. Besides, we study the performance optimization problems with different objectives for DTF and develop three optimum fusion rules accordingly. Simulation results reveal that DTF shows evident performance gains over an existing scheme.

Comparison of Culture, Conventional and Real-time PCR Methods for Listeria monocytogenes in Foods

  • Kim, Dong-Hyeon;Chon, Jung-Whan;Kim, Hyunsook;Kim, Hong-Seok;Choi, Dasom;Kim, Young-Ji;Yim, Jin-Hyeok;Moon, Jin-San;Seo, Kun-Ho
    • Food Science of Animal Resources
    • /
    • v.34 no.5
    • /
    • pp.665-673
    • /
    • 2014
  • We compared standard culture methods as well as conventional PCR and real-time PCR for the detection of Listeria monocytogenes (L. monocytogenes) in milk, cheese, fresh-cut vegetables, and raw beef that have different levels of background microflora. No statistical differences were observed in sensitivity between the two selective media in all foods. In total, real-time PCR assay exhibited statistically excellent detection sensitivity (p<0.05) and was less time consuming and laborious as compared with standard culture methods. Conventional culture methods showed poor performance in detecting L. monocytogenes in food with high levels of background microflora, generating numerous false negative results. While the detection of L. monocytogenes in fresh cut vegetable by culture methods was hindered only by L. innocua, various background microflora, such as L. innocua, L. welshimeri, L. grayi, and Enterococcus faecalis appeared on the two selective media as presumptive positive colonies in raw beef indicating the necessity of improvement of current selective media. It appears that real-time PCR is an effective and sensitive presumptive screening tool for L. monocytogenes in various types of foods, especially foods samples with high levels of background microflora, thus complementing standard culture methodologies.

Performance Analysis of DMF Acquisition System in Frequency-Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서의 DMF 초기동기 장치의 성능분석)

  • 김성철;이연우;조춘근;박형근;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.24 no.7B
    • /
    • pp.1351-1360
    • /
    • 1999
  • In frequency selective channels, conventional PN code acquisition schemes are not ideal candidates. This is because they are primarily designed for the AWGN channel. In this paper, a direct-sequence spread-spectrum(DSSS) PN code acquisition system based on digital matched filtering (DMF) with automatic threshold control(ATC) algorithm is presented and analyzed with regards to probability of detection and probability of false alarm. These two important probabilities, the probability of detection ($P_D$) and the probability of false alarm ($P_{FA}$) are derived and analyzed in considering Doppler shift, sampling rate, mean acquisition time, and PN chip rate in frequency selective Rayleigh fading channel when using serial-search method as detection technique. From computer simulation results of a DMF acquisition system model, it is shown that the performance of the acquisition system using ATC algorithm is better than that of constant threshold system.

  • PDF

Implementation of Preceding Vehicle Break-Lamp Detection System using Selective Attention Model and YOLO (선택적 주의집중 모델과 YOLO를 이용한 선행 차량 정지등 검출 시스템 구현)

  • Lee, Woo-Beom
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.22 no.2
    • /
    • pp.85-90
    • /
    • 2021
  • A ADAS(Advanced Driver Assistance System) for the safe driving is an important area in autonumous car. Specially, a ADAS software using an image sensors attached in previous car is low in building cost, and utilizes for various purpose. A algorithm for detecting the break-lamp from the tail-lamp of preceding vehicle is proposed in this paper. This method can perceive the driving condition of preceding vehicle. Proposed method uses the YOLO techinicque that has a excellent performance in object tracing from real scene, and extracts the intensity variable region of break-lamp from HSV image of detected vehicle ROI(Region Of Interest). After detecting the candidate region of break-lamp, each isolated region is labeled. The break-lamp region is detected finally by using the proposed selective-attention model that percieves the shape-similarity of labeled candidate region. In order to evaluate the performance of the preceding vehicle break-lamp detection system implemented in this paper, we applied our system to the various driving images. As a results, implemented system showed successful results.

Trends in Rapid Detection Methods for Food-borne pathogenic Microorganisms by Using New Technologies (신기술 이용 식중독균 신속검출법 개발 동향 분석)

  • Kim, Hyun-Joo;Kim, Yong-Soo;Chung, Myung-Sub;Oh, Deog-Hwan;Chun, Hyang-Sook;Ha, Sang-Do
    • Journal of Food Hygiene and Safety
    • /
    • v.25 no.4
    • /
    • pp.376-387
    • /
    • 2010
  • Recently, speedy, convenient and easy detection technologies have been developed rapidly and on the contrary, studies on development of traditional detectors applying biochemical characteristics has gradually been decreased. This review examined trend in current studies on detection of food-borne pathogenic microorganisms in the fields of selective media, immuno-assay, Polymerase Chain Reaction (PCR), microarray, terahertz spectroscopy & imagination and so on. Most traditional methods to detect the organisms from food matrix rely on selective media and such a method have disadvantages like long time requirement and distinguishing one species only from each selective medium although they are highly economical. Various new convenient methods such as Enzyme Linked Immuno-sorbent Assay (ELISA), paper-strip kit, fluoroimmunoassay etc. have been developed. The most ideal method for detecting food-borne pathogenic microorganisms in foods should be accurate, convenient, rapid and economical. Additionally, it is needed that capabilities of quantitative analysis and automation to be applied to industries.

Future Perspectives on New Approaches in Pathogen Detection

  • Li, Peng;Ho, Bow;Ding, Jeak Ling
    • Biomedical Science Letters
    • /
    • v.21 no.4
    • /
    • pp.165-171
    • /
    • 2015
  • Microbial pathogens are responsible for most of the rapidly-spreading deadly infectious diseases against humans. Thus, there is an urgent need for efficient and rapid detection methods for infectious microorganisms. The detection methods should not only be targeted and specific, but they have to be encompassing of potential changes of the pathogen as it evolves and mutates quickly during an epidemic or pandemic. The existing diagnostics such as the antibody-based ELISA immunoassay and PCR methods are too selective and narrowly focused; they are insufficient to capture newly evolved mutant strains of the pathogen. Here, we introduce a fresh perspective on some new technologies, including aptamers and next generation sequencing for pathogen detection. These technologies are not in their infancy; they are reasonably mature and ready, and they hold great promise for unparalleled applications in pathogen detection.

Highly Copper(II)-selective PVC Membrane Based on a Schiff Base Complex of N,N'-Bis-pyridin-2-ylmethylene-naphthalene-1,8-diamine as an Ionophore

  • Jeong, Dae-Cheol;Lee, Hyo-Kyoung;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.27 no.10
    • /
    • pp.1593-1596
    • /
    • 2006
  • The polymeric membrane electrodes based on N,N'-bis-pyridin-2-ylmethylene-naphthalene-1,8-diamine as an ion carrier were prepared and tested for the copper-ion selective electrode. The membrane has a linear dynamic range between $10^{-6}$ and $10^{-2}$ M with a Nernstian slope of 29.6 mV per decade, and its detection limit was $10^{-5.62}$M. The potentiometric response is independent of the pH range of 3-5. The proposed electrode showed good selectivity and response for $Cu^{2+}$ over a wide variety of other metal ions in pH 4.0 buffer solutions.

A New Selective Membrane Electrode for Oxalate Based on N,N'-Bis(salicylidene)-2,2-dimethylpropane-1,3-diamine Ni(II)

  • Ardakani, M.Mazloum;Iranpoor, F.;Karimi, M.A.;Salavati-Niasari, M.
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.2
    • /
    • pp.398-404
    • /
    • 2008
  • A new solvent polymeric membrane electrode, based on N,N'-bis(salicylidene)-2,2-dimethylpropane-1,3-diamine Ni(II) as the ionophore, was designed. The oxalate-selective electrode has the dynamic range between 1.0 10-6 M and 1.0 10-1 M with a Nernstian slope of -28.7 1.0 mV per decade. The detection limit was 6.3 10-7 M. The proposed electrode revealed good selectivities for oxalate over a variety of other anions and could be used in a pH range of 2.0-7.8. The electrode can be used for at least two months without any considerable divergence in potential. The designed electrode was applied as an indicator electrode in the potentiometric determination of oxalate in real samples.

Polymeric Iodide-ion Selective Electrodes Based on Urea Derivative as an Ionophore

  • Jeong, Dae-Cheol;Lee, Hyo-Kyoung;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.27 no.12
    • /
    • pp.1985-1988
    • /
    • 2006
  • The polymeric membrane electrodes based on urea derivative as an ionophore were prepared and studied for the iodide-ion selective electrode. This membrane exhibits a linear stable response over a wide concentration range ($1.0\;{\times}\;10^{-5}\sim1.0\;{\times}\;10^{-2}$) with a slope of -57.7 mV/decade, a detection limit of log[$I^-$] = -5.63, and a selectivity coefficient for iodide against perchlorate anion (log$K^{pot}_{I^-,j}$ = -1.42). The selectivity series of the membrane gives the follow as $I^-$ > $SCN^-$, $Sal^-$ > $ClO_4^-$ > $NO_3^-$ > $Br^-$ > $NO_2^-$ > $Cl^-$ > $F^-$. The proposed electrode showed good selectivity and response for iodide anion over a wide variety of other anions in pH 5.0 buffer solutions.