• 제목/요약/키워드: Period Detection

검색결과 1,163건 처리시간 0.025초

원전 증기발생기 세관 검사를 위한 와전류 탐상 프로브의 현황 및 전망 (Present Condition and View of Eddy Current Testing Probe for Nuclear Power Plant Steam Generator Tube Examination)

  • 김지호;이향범
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2006년도 하계학술대회
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    • pp.241-245
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    • 2006
  • In the examination of Steam Generator (SG) tube in Nuclear Power Plant (NPP) Eddy Current Testing (ECT) probes play an Important role in detecting the defects. Bobbin probe and Rotating Pancake Coil (RPC) probe is usually used for the inspection of SG tube. Bobbin probe is good at high speed inspection, but ability of detection of circumferential defect is very weak. On the contrary RPC probe, which moves for inspection in the direction of axial and circumferential simultaneously, has very slow inspection speed, but it was excellent detection capability fur small cracks, which is hardly detected by bobbin probe. Many examinations of SG tube examination of NPP are achieved during short period. Therefore, solution about this must develop probe of new form for examination performance and examination time shortening of other probe. In this paper, analyzed technological present condition of Bob-bin probe and RPC probe been using in Nondestructive Testing (NDT) for SG tube defect detection and Appeared about background theory and view of developed probe newly.

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M-Mode 초음파 영상을 이용한 태동의 자동 검출 (Automatic Detection of Fetal Movement Using M-Mode Ultrasonography)

  • 권중혁;강동주;김새별;박문일;김선일
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1998년도 추계학술대회
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    • pp.179-180
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    • 1998
  • In this paper, we propose an algorithm to detect fetal movements using M-mode ultrasonography. To do this work automatically, we find the crosscorrelation between the current data vector of the depth direction of M-mode image and the previous one. In the crosscorrelation estimator, the variations of time lag $\tau$ at maximum crosscorrelation value means fetal movements. A woman in the 37th week of pregnancy was monitored and the ultrasonic image of fetus was recorded over 20-minute period to detect fetal movements using B-mode and M-mode ultrasonography simultaneously. And the presented method was compared with maternal perception and B-mode ultrasonography observed by clinician. The maternal perception method detected only 57% of all fetal movements observed by clinician. The detection of the presented method corresponds to the clinician's detection result.

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우유내 잔류물질 검사방법인 TTC-II법 및 Disk assay법의 비교시험 (Comparision of TTC-II and disk assay method for the detection of antibiotic residues in milk)

  • 이정아;이은미;이성해;도재철;박영구
    • 한국동물위생학회지
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    • 제22권1호
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    • pp.93-101
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    • 1999
  • This test process on screening method for the detection of residual antibiotics in milk is simple, economic, sensitive to residual antibiotics and was given approval international organs. Thus, this study was carried out the comparison of Disk assay method and TTC-II method for sensitivity and minimum detectable range of antibiotics in raw milk. The results of this study was summarized as follows ; 1. The number of samples requested for treatment of mastitis was 198 samples. Comparison or analytical results among the methods of TTC-II, disk assay and Delve sp was that TTC-II 37 samples(18.6% ), Disk assay 125samples(63.1%), Delve SP 130 samples(65.7% ) reacted positively. Conformity rate of Delve SP and Disk assay was 70%. 2. Detectable limits of disk assay method in some antibiotics were more sensitive than those of official method(0.05-0.0025ppm in the $\beta$-lactams, 1ppm in two aminoglycoside, 0.2 ppm in one tetracycline, similar in one macrolide) 3. For sensitivity of residual sulfonamides TTC-II was much more sensitive than disk assay. Detectable limits of sulfamethazine and sulfadimethoxine were 30 to 50ppm levels. 4. The best medium preservation period is 1-2 days. 5. Concentration of brome cresol purple related to resistance for B stearothermophilus culture was 24ppm/ml. These results show that disk assay method for screening detection of antibiotics residuces in milk is worthy of use.

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양식 넙치, Paralichthys olivaceus 질병에 대한 통계적 고찰 (A statistical study on infectious diseases of cultured olive flounder, Paralichthys olivaceus in Korea)

  • 조미영;김명석;최혜승;박경현;김진우;박미선;박명애
    • 한국어병학회지
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    • 제21권3호
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    • pp.271-278
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    • 2008
  • The epidemiological study was performed to survey the prevalence of 5 bacterial, 6 viral and 5 parasitic disease of cultured olive flounder, Paralichthys olivaceus in Pohang, Ulsan∙Gijang, Keoje and Wando area of Korea from February to December, 2007. The disease frequency of size groups were as follows; Among the 1,218 fish samples, less than 10 cm (67.6%), 11~20 cm (70.2%), 21~30 cm (73.4%), 31~40 cm (77.6%), above 41 cm (88.2%). The highest detection rates of pathogens were recorded in samples from August and Ulsan. The detection rates of parasites, bacteria or viruses were 43.2%, 38.8% and 24.4%, respectively. The distribution of specific diseases showed that detection rates of diseases occurring the most frequently during the study period were Trichodina (33.1%), viral nervous necrosis virus (16.0%), Vibrio (9.7%), Scutica (10.1%), Ichthyobodo (5.7%).

Practicalities of structural health monitoring

  • Shrive, P.L.;Brown, T.G.;Shrive, N.G.
    • Smart Structures and Systems
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    • 제5권4호
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    • pp.357-367
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    • 2009
  • Structural Health Monitoring (SHM), particularly remote monitoring, is an emerging field with great potential to help infrastructure owners obtain more and up-to-date knowledge of their structures. The methodology could provide supplemental information to guide the frequency and extent of visual inspections, and the possible need for maintenance. The instrumentation for a SHM system needs to be developed with longevity and the objectives for the system in mind. Sensors need to be selected for reliability and durability, sited where they provide the maximum information for the objectives, and where they can be accessed and replaced should the need arise over the monitoring period. With the rapid changes now occurring with sensors and software, flexibility needs to be in place to allow the system to be upgraded over time. Damage detection needs to be considered in terms of the type of damage that needs to be detected, informing maintenance requirements, and how detection can be achieved. Current vibration analysis techniques appear not yet to have achieved the necessary sensitivity for that purpose. Societal factors will influence the design of a SHM system in terms of the sophistication of the instrumentation and methodology employed.

Effect of Brown-rotted Wood on Mechanical Properties and Ultrasonic Velocity

  • Lee, Sang-Joon;Kim, Gyu-Hyeok;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • 제36권5호
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    • pp.24-32
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    • 2008
  • Artificial brown-rot decay was induced to two wood species, Pinus densiflora and Pinus radiata. A modified direct inoculation method was used and the decay indicators of mass loss and two compressive mechanical properties, maximum compressive strength (MCS) and compressive stiffness, were estimated over the period of 8 weeks of fungal exposure. Measurable mass loss occurred 2 weeks after the fungal attack, with 15% to 22% of the loss occurring 8 weeks after fungal exposure with Fornitopsis palustris and Gloeophyllurn trabeurn. Mechanical properties proved to be far more sensitive than mass loss detection: approximately five to six times by quantity. Of the two mechanical properties, MCS was more sensitive to and consistent with progressive brown-rot decay. An ultrasonic test was performed to determine the feasibility and accuracy of this method for nondestructive detection of brown-rot decay. The ultrasonic test is highly sensitive at qualitative detection of the early stages of brown-rot decay.

고장진단 기능을 갖는 선박 횡동요 감요 장치 용 제어시스템 개발 (Development of Control System for Anti-Rolling Tank of Ships with Fault Detection Capability)

  • 원문철;류상현;최광식;정윤호;류재문;지용진
    • 한국해양공학회지
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    • 제24권3호
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    • pp.64-71
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    • 2010
  • This paper summarizes the development of an ART control system panel with a touch screen and sensors to measure the roll and roll rate of ships. The control system hardware consists of two micro-processors, analog and digital I/O circuits, various relay circuits, etc. Sensor fusion and moving cross algorithms are implemented to accurately estimate the roll angle and roll period. In addition, the control system adopts a fault detection algorithm to inform users of ART system faults. A touch screen in the control panel can display the ART system states and faults. The performance of the developed system was verified on real sea trials.

고주파를 이용한 송전선로의 사고 검출 및 판별에 관한 연구 (A Study on the Fault Detection and Discrimination of Transmission Line using Fault-generated High Frequency Signals)

  • 이동준;김철환;김일동
    • 대한전기학회논문지:전력기술부문A
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    • 제48권8호
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    • pp.924-931
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    • 1999
  • Most conventional protection relays are based on processing information in the spectrum that is close to or at power frequency. It is, however, widely known that faults on transmission lines produce frequency components of a wide range. High frequency signals caused by sudden changes in system voltage that occurs in the immediate post-fault period are generally outside the bandwidth of receptibility of most protection scheme. In this respect, a specially designed stack tuner is connected to the coupling capacitor of CVT, in order to capture the high frequency signals. Digital signal processing is then applied to the captured information to determine whether the fault is inside or outside the protected zone, and to discriminate the fault type. In this paper, modal transform is not applied to fault generated signals, because signals which are converted by modal transform are not have an information of each phase any longer. Instead, using peak voltage value of data windows is able to discriminate fault type. The paper concludes by presenting fault detection and discrimination of various faults on transmission line which are based on extensive simulation studies carried out on a typical 154kV Korean transmission line, using the EMTP software.

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2001-2016년 까지 바이러스성출혈성패혈증바이러스 (viral hemorrhagic septicemia virus)의 국내 검출 동향 분석 (Study on the tendency of viral hemorrhagic septicemia virus (VHSV) detection in Korea from 2001 to 2016 based on reported cases)

  • 장민석;김종오;오명주;김위식
    • 한국어병학회지
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    • 제31권1호
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    • pp.49-55
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    • 2018
  • Tendency of viral hemorrhagic septicemia virus (VHSV) detection from 2001 to 2016 in Korea was studied based on 15 reported cases. Since the VHSV was first detected from cultured olive flounder (Paralichthys olivaceus) in Pohang in 2001, it has been continuously reported from olive flounder farms in various regions of the Korean coastal area. So far, the virus has been detected from 2 farmed fishes, 12 wild marine fishes and 2 marine bivalves. All the 67 isolates were belong to VHSV genotype IVa. The predisposing factor analysis from different olive flounder farms revealed that the VHSV were highly detected from the juveniles under 40 g in body weight, in the temperature range from 9.5 to $17^{\circ}C$ and during the period of March to June. Therefore, we recommend that farmers, need to exercise caution against VHSV infection in Spring.

Strain-specific Detection of Kimchi Starter Leuconostoc mesenteroides WiKim33 using Multiplex PCR

  • Lee, Moeun;Song, Jung Hee;Park, Ji Min;Chang, Ji Yoon
    • 한국식생활문화학회지
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    • 제34권2호
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    • pp.208-216
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    • 2019
  • Leuconostoc spp. are generally utilized as kimchi starters, because these strains are expected to have beneficial effects on kimchi fermentation, including improvement of sensory characteristics. Here, we developed a detection method for verifying the presence of the kimchi starter Leuconostoc mesenteroides WiKim33, which is used for control of kimchi fermentation. A primer set for multiplex polymerase chain reaction was designed based on the nucleotide sequence of the plasmids in strain WiKim33, and their specificity was validated against 45 different strains of Leuconostoc spp. and 30 other strains. Furthermore, the starter strain consistently tested positive, regardless of the presence of other bacterial species in starter kimchi during the fermentation period. Our findings showed that application of a strain-specific primer set for strain WiKim33 presented a rapid, sensitive, and specific method for detection of this kimchi starter strain during natural kimchi fermentation.