• Nuclear Engineering and Technology
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• 제25권3호
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• pp.403-412
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• 1993

마이크로 프로세서 기술의 도입으로 계측시스템은 점차 지능화 되어가고 있다. 이 연구에서는 원자력 공학에서의 온도 계측에 적용하기 위한 지능형 송출기의 설계가 수행되었다. 지능형 송출기 기법의 원자력에의 응용을 위해 디지탈 시간 지연 보상 함수와 수위 측정 알고리듬이 고안, 적용되었다. 시간 보상 함수는 계측된 신호의 시간 지연을 효과적으로 보상하여 주지만, 그 응용에 따라 보상 특성이 고려되어야 한다는 점이 발견되었다. 또한, 수위 계측 함수는 잡음이 많이 섞이고 그 시상수가 250초 이상인 신호를 처리하여 수위 계측 시간을 약 7초로 단축시켜 준다는 사실도 발견하였다.

• 대한의생명과학회지
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• 제25권4호
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• pp.331-338
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• 2019

Human Aichivirus A1 (HuAiV-A1) is a waterborne human pathogenic virus classified as Picornaviridae and Kobuvirus. In this study, we developed a method that can detect about 35 minutes faster with the same detection sensitivity level than the previously reported HuAiV-A1 diagnostic RT-PCR primer. The RT-PCR primer sets developed in this study are capable of detecting HuAiV-A1 at a level of about 100 ag and formed 563 bp amplification product. In addition, the RT-nested PCR method was able to amplify 410 bp using the RT-PCR product as a template. The detection sensitivity of our method was 10 times higher than the method with the highest detection sensitivity to date. Therefore, the detection method of HuAiV-A1 developed in this study is expected to be used in the water environment in which a small amount of virus exists. Also, this detection method is expected to be used as HuAiV-A1 diagnostic technology in both clinical and non-clinical field.

• Nuclear Engineering and Technology
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• 제33권5호
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• pp.483-497
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• 2001

In this work, a neuro-fuzzy inference system combined with the wavelet denoising, PCA (principal component analysis) and SPRT (sequential probability ratio test) methods is developed to detect the relevant sensor failure using other sensor signals. The wavelet denoising technique is applied to remove noise components in input signals into the neuro-fuzzy system The PCA is used to reduce the dimension of an input space without losing a significant amount of information. The PCA makes easy the selection of the input signals into the neuro-fuzzy system. Also, a lower dimensional input space usually reduces the time necessary to train a neuro-fuzzy system. The parameters of the neuro-fuzzy inference system which estimates the relevant sensor signal are optimized by a genetic algorithm and a least-squares algorithm. The residuals between the estimated signals and the measured signals are used to detect whether the sensors are failed or not. The SPRT is used in this failure detection algorithm. The proposed sensor-monitoring algorithm was verified through applications to the pressurizer water level and the hot-leg flowrate sensors in pressurized water reactors.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.262-265
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• 2007

Preliminary results are reported on ship detection using coherence images computed from cross-correlating images of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships are correlated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, cross-correlation of multi-look images yields the different degrees of coherence between the images and water. The polarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation between HH and HV. In the next step, we examine the technique when the dual-polarization data are split into two multi-look Images.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 춘계학술대회 논문집
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• pp.180-184
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• 2008

Preliminary results are reported on ship detection using coherence images computed from crosscorrelating images of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships are correlated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, crosscorrelation of multi-look images yields the different degrees of coherence between the images and water. The polarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation between HH and HV. In the next step, we examine the technique when the dual-polarization data are split into two multi-look images.

• Environmental Analysis Health and Toxicology
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• 제11권1_2호
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• pp.11-17
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• 1996

The purpose of this experiment is to estabilish the sensitive and specific ELISA (enzyme linked immunosorbent assay) system for the detection of fish metallothionein (MT). Silver carp were injected with CA of 1-8mg/kg body wt. 4 times during 10 days. Silver carp was very tolerant species to CA. Cd induced MT in liver was seperated and purified by gel filtration chromatography and ion exchange chromatography and identified by spectrophotometry, native gel electrophoresis and western blot analysis. The rabbit antiserum was produced by immunizing rabbit with lyophilized MT, and the competitive ELISA system was estabilished for the detection of fish MT. In the present ELISA system, the detection limit was about 33 ng/ml. When this ELISA system was employed to determine the MT level in the supernatant sample of fish liver homogenate, the reaction curve showed a good parallel corelationship with the calibration curve over a certain dilution range. The results indicate that the competitive ELISA can be a useful tool for the detection of fish MT in the toxicological study and the evaluation of water pollution.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.12-15
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• 2011

The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

• 상하수도학회지
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• 제35권1호
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• pp.15-25
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• 2021

In this study, a method of leakage detection was proposed to locate leak position for a reservoir pipeline valve system using wavelet coherence analysis for an injected pressure wave. An unsteady flow analyzer handled nonlinear valve maneuver and corresponding experimental result were compared. Time series of pressure head were analyzed through wavelet coherence analysis both for no leak and leak conditions. The leak information can be obtained through either time domain reflectometry or the difference in wavelet coherence level, which provide predictions in terms of leak location. The reconstructed pressure signal facilitates the identification of leak presence comparing with existing wavelet coherence analysis.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.569-573
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• 2010

A quantitative detection method for Salmonella in seafood was developed using a SYBR Green-based real-time PCR assay. The assay was developed using pure Salmonella DNA at different dilution levels [i.e., 1,000 to 2 genome equivalents (GE)]. The sensitivity of the real-time assay for Salmonella in seeded seafood samples was determined, and the minimum detection level was 20 CFU/g, whereas a detection level of 2 CFU/ml was obtained for pure culture in water with an efficiency of ${\geq}85%$. The real-time assay was evaluated in repeated experiments with seeded seafood samples and the regression coefficient ($R^2$) values were calculated. The performance of the real-time assay was further assessed with naturally contaminated seafood samples, where 4 out of 9 seafood samples tested positive for Salmonella and harbored cells <100 GE/g, which were not detected by direct plating on Salmonella Chromagar media. Thus, the method developed here will be useful for the rapid quantification of Salmonella in seafood, as the assay can be completed within 2-3 h. In addition, with the ability to detect a low number of Salmonella cells in seafood, this proposed method can be used to generate quantitative data on Salmonella in seafood, facilitating the implementation of control measures for Salmonella contamination in seafood at harvest and post-harvest levels.

• 한국수자원학회논문집
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• 제34권4호
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• pp.357-364
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• 2001

실험 또는 계측에 의해 관측된 관측치들은 종종 어떤 기준치 이하의 작은 값들이 기록되는데, 이들 기준치 이하의 값들이 크기는 미소할지라도 평균이나 분산 추정시 왜곡된 결과를 줄 수 있다. 그러나 우리 나라에서는 관측오차로 간주하여 N.D.(Not Detected)로 처리하는 것을 관례로 하고 있어 미소치들이 기록되지 않고 있다. EK라서 본 연구에서는 부여 취수장의 암모니아성 질소(NH$_3$-N)자료가 크기에 따라 분표형이 다름을 조사하고 그 분포를 구별할 수 있는 기준치와 기준치 이하의 자료들에 대한 평균과 분산 추정시 가장 적절한 기법을 찾고자 하였다. 즉, 기준치 이하의 값들과 이상의 값들을 구분하여 평균과 분산을 위한 적절한 기법을 선정하여 추정하였다. 분석 결과 부여취사장의 자료는 편기 수정된 최우도(Bias Corrected ML)법이 가장 적합한 것으로 결정되었으며, 시행착오법에 의하여 기준치를 설정하였다.