• Title/Summary/Keyword: method detection limit

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MOTION VECTOR DETECTION ALGORITHM USING THE STEEPEST DESCENT METHOD EFFECTIVE FOR AVOIDING LOCAL SOLUTIONS

  • Konno, Yoshinori;Kasezawa, Tadashi
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.460-465
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    • 2009
  • This paper presents a new algorithm that includes a mechanism to avoid local solutions in a motion vector detection method that uses the steepest descent method. Two different implementations of the algorithm are demonstrated using two major search methods for tree structures, depth first search and breadth first search. Furthermore, it is shown that by avoiding local solutions, both of these implementations are able to obtain smaller prediction errors compared to conventional motion vector detection methods using the steepest descent method, and are able to perform motion vector detection within an arbitrary upper limit on the number of computations. The effects that differences in the search order have on the effectiveness of avoiding local solutions are also presented.

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Microbial detection on pill types of herbal medicine in South Korea (국내 유통 중인 환약의 미생물 검출수준)

  • Ko, Gwang-Pyo;Shin, Heon-Tae
    • Journal of Society of Preventive Korean Medicine
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    • v.15 no.3
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    • pp.153-162
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    • 2011
  • Objectives : This study has aimed to monitor microbial detection on pill types of herbal medicine which are circulating in markets including Oriental Medical Clinics(O.M.C.s) and Pharmacy in Korea. Methods : 10 different samples of O.M.Cs and 10 different samples of Pharmacy were investigated by culture method and non-culture method based on the 9th edition of microbial examination released by Korea Food & Drug Administration. Results : The total microbial count among each 10 samples were detected within the limit suggested by WHO. 2 samples of O.M.C.s and 1 samples of Pharmacy exceeded WHO's limit in fungi count. No samples exceeded WHO's limit in bacteria count. Most bacteria founded in samples were the phylum of Firmicutes and Proteobacteria which are common in soil by non-culture method. Conclusion : Further study should be followed to set up proper microbial limit of herbal materials including pill types.

Development of a One-Step Duplex RT-PCR Method for the Simultaneous Detection of VP3/VP1 and VP1/P2B Regions of the Hepatitis A Virus

  • Kim, Mi-Ju;Lee, Shin-Young;Kim, Hyun-Joong;Lee, Jeong Su;Joo, In Sun;Kwak, Hyo Sun;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • v.26 no.8
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    • pp.1398-1403
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    • 2016
  • The simultaneous detection and accurate identification of hepatitis A virus (HAV) is critical in food safety and epidemiological studies to prevent the spread of HAV outbreaks. Towards this goal, a one-step duplex reverse-transcription (RT)-PCR method was developed targeting the VP1/P2B and VP3/VP1 regions of the HAV genome for the qualitative detection of HAV. An HAV RT-qPCR standard curve was produced for the quantification of HAV RNA. The detection limit of the duplex RT-PCR method was 2.8 × 101 copies of HAV. The PCR products enabled HAV genotyping analysis through DNA sequencing, which can be applied for epidemiological investigations. The ability of this duplex RT-PCR method to detect HAV was evaluated with HAV-spiked samples of fresh lettuce, frozen strawberries, and oysters. The limit of detection of the one-step duplex RT-PCR for each food model was 9.4 × 102 copies/20 g fresh lettuce, 9.7 × 103 copies/20 g frozen strawberries, and 4.1 × 103 copies/1.5 g oysters. Use of a one-step duplex RT-PCR method has advantages such as shorter time, decreased cost, and decreased labor owing to the single amplification reaction instead of four amplifications necessary for nested RT-PCR.

Simultaneous Analysis of Semi-Volatile Organic Acid Priority Pollutants in Soil (토양 중의 비휘발성 산성 유기 Priority Pollutants 동시분석에 관한 연구)

  • Lee, Seung Seok;Park, Gyo Beom;Lee, Seong Geun
    • Journal of the Korean Chemical Society
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    • v.38 no.3
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    • pp.246-253
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    • 1994
  • The simultaneous analysis of 11 semi-volatile organic acid compound which are listed as priority pollutants by EPA, were performed by GC/MS-SIM(selected ion monitoring). Two extraction procedures, sonication extraction and Soxhlet extraction, were studied as an extraction and concentration method for priority pollutants in soil. Accurecy and precision of the methods were measured by the calculation of mean recovery, mean relative standard deviation, and method detection limit. Finally, limitations and prospects were discussed.

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Electrochemical Behavior of Norfloxacin and Its Determination at Poly(methyl red) Film Coated Glassy Carbon Electrode

  • Huang, Ke-Jing;Xu, Chun-Xuan;Xie, Wan-Zhen
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.988-992
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    • 2008
  • A poly(methyl red) film-modified glassy carbon electrode (PMRE) was fabricated for determination of norfloxacin (NFX). The electrochemical behavior of NFX was investigated and a well-defined oxidation peak with high sensitivity was observed at the film electrode. PMRE greatly enhanced the oxidation peak current of NFX owing to the extraordinary properties of poly(methyl red) film. Based on this, a sensitive and simple voltammetric method was developed for measurement of NFX. A sensitive linear voltammetric response for NFX was obtained in the concentration range of $1\;{\times}\;10^{-6}\;-\;1\;{\times}\;10^{-4}$ mol/L and the detection limit was $1\;{\times}\;10^{-7}$ mol/L using linear sweep voltammetry (LSV). The proposed method possessed advantages such as low detection limit, fast response, low cost and simplicity. The practical application of this new analytical method was demonstrated with NFX pharmaceuticals.

Development of a lateral flow dipstick test for the detection of 4 strains of Salmonella spp. in animal products and animal production environmental samples based on loop-mediated isothermal amplification

  • Wirawan Nuchchanart;Prapasiri Pikoolkhao;Chalermkiat Saengthongpinit
    • Animal Bioscience
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    • v.36 no.4
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    • pp.654-670
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    • 2023
  • Objective: This study aimed to develop loop-mediated isothermal amplification (LAMP) combined with lateral flow dipstick (LFD) and compare it with LAMP-AGE, polymerase chain reaction (PCR), and standard Salmonella culture as reference methods for detecting Salmonella contamination in animal products and animal production environmental samples. Methods: The SalInvA01 primer, derived from the InvA gene and designed as a new probe for LFD detection, was used in developing this study. Adjusting for optimal conditions by temperature, time, and reagent concentration includes evaluating the specificity and limit of detection. The sampling of 120 animal product samples and 350 animal production environmental samples was determined by LAMP-LFD, comparing LAMP-AGE, PCR, and the culture method. Results: Salmonella was amplified using optimal conditions for the LAMP reaction and a DNA probe for LFD at 63℃ for 60 minutes. The specificity test revealed no cross-reactivity with other microorganisms. The limit of detection of LAMP-LFD in pure culture was 3×102 CFU/mL (6 CFU/reaction) and 9.01 pg/μL in genomic DNA. The limit of detection of the LAMP-LFD using artificially inoculated in minced chicken samples with 5 hours of pre-enrichment was 3.4×104 CFU/mL (680 CFU/reaction). For 120 animal product samples, Salmonella was detected by the culture method, LAMP-LFD, LAMP-AGE, and PCR in 10/120 (8.3%). In three hundred fifty animal production environmental samples, Salmonella was detected in 91/350 (26%) by the culture method, equivalent to the detection rates of LAMP-LFD and LAMP-AGE, while PCR achieved 86/350 (24.6%). When comparing sensitivity, specificity, positive predictive value, and accuracy, LAMP-LFD showed the best results at 100%, 95.7%, 86.3%, and 96.6%, respectively. For Kappa index of LAMP-LFD, indicated nearly perfect agreement with culture method. Conclusion: The LAMP-LFD Salmonella detection, which used InvA gene, was highly specific, sensitive, and convenient for identifying Salmonella. Furthermore, this method could be used for Salmonella monitoring and primary screening in animal products and animal production environmental samples.

Obstacle Position Detection on an Inclined Plane Using Randomized Hough Transform and Corner Detection (랜덤하프변환과 코너추출을 이용한 경사면의 장애물 위치 탐색)

  • Hwang, Sun-Min;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.5
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    • pp.419-428
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    • 2011
  • This paper suggests a judgement method for an inclined plane before entrance of it and the detection of obstacle position. Main idea is started from the assumption that obstacle is always on the bottom plane, and corner appears at this position. The process to detect the obstacle consists of three steps. First the 3D data using stereo matching is acquired to detect an obstacle. Second a bottom plane is extracted by using limit condition. Last the obstacle position is found by using Harris corner detection. Obstacle position detection on an inclined plane was verified by outdoor and indoor experiment. In error analysis, it is confirmed that an average error of obstacle detection in outdoor was larger than the error in indoor but the error are within about 0.030 m. This method will be applied to unmanned vehicles to navigate under various environment.

Fundamental Study on the Limit of Thermographic Survey Applied to Detection of Void in Concrete (적외선법을 이용한 콘크리트 공동의 적용한계에 관한 기초적 연구)

  • ;Tanigawa Yasuo
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.799-806
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    • 1999
  • This study describes the results of experiment and numerical analysis for heating image by thermographic method when the size of void in concrete are changed. By comparing analytical solution by finite element method with measured image by thermography, the relationships between the surface temperature which can be confirmed by this method, the size of void and optimum time for detection of void and the difference of temperature are cleared.

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Automatic crack detection of dam concrete structures based on deep learning

  • Zongjie Lv;Jinzhang Tian;Yantao Zhu;Yangtao Li
    • Computers and Concrete
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    • v.32 no.6
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    • pp.615-623
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    • 2023
  • Crack detection is an essential method to ensure the safety of dam concrete structures. Low-quality crack images of dam concrete structures limit the application of neural network methods in crack detection. This research proposes a modified attentional mechanism model to reduce the disturbance caused by uneven light, shadow, and water spots in crack images. Also, the focal loss function solves the small ratio of crack information. The dataset collects from the network, laboratory and actual inspection dataset of dam concrete structures. This research proposes a novel method for crack detection of dam concrete structures based on the U-Net neural network, namely AF-UNet. A mutual comparison of OTSU, Canny, region growing, DeepLab V3+, SegFormer, U-Net, and AF-UNet (proposed) verified the detection accuracy. A binocular camera detects cracks in the experimental scene. The smallest measurement width of the system is 0.27 mm. The potential goal is to achieve real-time detection and localization of cracks in dam concrete structures.

Determination of amitraz by high-performance Liquid chromatography with photodiode array detection and method validation (HPLC-PDA를 이용한 Amitraz의 분석법 확립 및 검증)

  • Yun, Hyeong-Jun;Yun, So-Mi;Lee, Myoung-Heon;Son, Seong-Wan
    • Korean Journal of Veterinary Research
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    • v.48 no.1
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    • pp.33-38
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    • 2008
  • In veterinary medicine amitraz has been used as an insecticide to eliminates mites, lice, and ticks in dogs, cats, goats, swine and cattle. The objective of present study was to developed an analytical method using one-step extraction and determination of the amitraz in veterinary drugs by liquid chromatography (LC). The amitraz was analyzed by LC equipped with Waters XTerra RP18 ($4.8{\times}250mm;\;5{\mu}m;\;Waters,\;USA$) analytical column, using 75% acetonitrile (acetonitrile/D.W; 75/25) at 1.0 ml/ min. The UV-VIS detection of amitraz was made at 290 nm. Calibration graphs were linear with very good correlation coefficients ($r^2>0.9999$) from $80{\sim}120{\mu}g/ml$. The limit of detection was $0.09{\mu}g/ml $ and limit of quantification was $0.27{\mu}g/ml $. The method showed good intra-day precision (CV 0.05~0.09%) and inter-day precision (CV 0.06~0.18%).