• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1755-1762
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• 2013

A graphene-Zn/Al layered double hydroxide composite film was simultaneously prepared by electrochemical deposition on the surface of a glassy carbon electrode (G-LDH/GCE) from the mixture solution containing GO and nitrate salts of $Zn^{2+}$ and $Al^{3+}$. The modified electrode showed good electrochemical performances toward the simultaneous electrochemical detection of hydroquinone (HQ), catechol (CA) and resorcinol (RE) due to the unique properties of graphene (G) and LDH such as large active surface area, facile electronic transport and high electrocatalytic activity. The redox characteristics of G-LDH/GCE were investigated with cyclic voltammetry and differential pulse voltammetry. The well-separated oxidation peak potentials, corresponding to the oxidation of HQ, CA and RE, were observed at 0.126 V, 0.228 V and 0.620 V respectively. The amperometric response of the modified electrode exhibited that HQ can be detected without interference of CA and RE. Under the optimized conditions, the oxidation peak current of HQ is linear with the concentration of HQ from 6.0 ${\mu}M$ to 325.0 ${\mu}M$ with the detection limit of 0.077 ${\mu}M$ (S/N=3). The modified electrode was successfully applied to the direct determination of HQ in a local tap water, showing reliable recovery data.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권5호
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• pp.18-25
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• 2014

Traditional investigation procedures of soil and groundwater contamination are followed by soil gas sampling, soil sampling, groundwater sampling, establishment of monitoring wells, and groundwater monitoring. It often takes several weeks to obtain the analysis reports, and sometimes, it needs supplemental sampling and analysis to delineate the polluted area. Laser induced fluorescence (LIF) system is designed for the detection of free-phase petroleum pollutants, and it is suitable for on-site real-time site investigation when coupling with a direct push testing tool. Petroleum products always contain polycyclic aromatic hydrocarbon (PAH) compounds possessing fluorescence characteristics that make them detectable through LIF detection. In this study, LIF spectroscopy of 5 major fuel products was conducted to establish the databank of LIF fluorescence characteristic spectra, including gasoline, diesel, jet fuel, marine fuel and low-sulfur fuel. Multivariate statistical tools were also applied to distinguish LIF fluorescence characteristic spectra among the mixtures of selected fuel products. This study successfully demonstrated the feasibility of identifying fuel species based on LIF characteristic fluorescence spectra, also LIF seemed to be uncovered its powerful ability of tracing underground petroleum leakages.

• 대한전자공학회논문지SP
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• 제41권6호
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• pp.147-154
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• 2004

본 논문에서는 반전 좌표계 영상 공간 (inverted-coordinate image space: ICIS)을 이용하여 유한 및 무한 소실점을 그 위치의 제약이나 카메라 보정 (calibration) 없이 효과적으로 검출하는 방법을 제안하였다. 제안한 방법에서는 소실점 검출을 위한 무한(unbounded) 누적 공간을 한정된 부공간 (bounded subspace)들로 분할 매핑하기 때문에 기존의 영상 공간 기반법과 달리 모든 영상에 대해 소량의 고정 메모리 요구량으로도 유, 무한 소실점을 모두 검출할 수 있다. 영상 공간을 누적 공간으로 이용하기 때문에 기존의 가우시안 구 (Gaussian sphere) 기반법이나 허프 공간 (Hough) 기반법과도 달리 카메라 보정이나 원 영상에 대한 정보손실 없이 각 소실점들을 정확하게 추출할 수 있다. 제안한 방법을 다양한 건축 구조물 영상 (architectural images)에 적용시켜 유한 및 무한 소실점들을 효과적이고 정확하게 검출할 수 있음을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1021-1024
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• 2001

Out of all metal-cutting processes, the hole-making process is the most widely used. It is estimated to be more than 30% of the total metal-cutting process. It is therefore desirable to monitor and detect drill wear during the hole-drilling process. In this paper, the vision system of the sensing methods of drill flank wear on the basis of image processing is used to detect the wear pattern by non-contact and direct method and get the reliable wear information about drill. In image processing of acquired image, median filter is applied for noise removal. The vision flank wear area of the drill was measured. Backpropagation neural networks (BPns) were used for no-line detection of drill wear. The neural network consisted of three layers: input, hidden and output. The input vectors comprised of spindle rotational speed, feed rates, vision flank wear, thrust and torque signals. The output was the drill wear state which was either usable or failure. Drilling experiments with various spindle rotational speed and feed rates were carried out. The learning process was peformed effectively by utilizing backpropagation. The detection of the abnormal states using BPNs achieved 96.4% reliability even when the spindle rotational speed and feedrate were changed.

• The Plant Pathology Journal
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• 제16권5호
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• pp.252-256
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• 2000

The 16S-23S rRNA intergenic spacer regions (ISRs) were sequenced and analyzed to design specific primer for identification of Pectobacterium chrysanthemi. Two types ISRs, large and small ISRs, were identified from three strains (ATCC 11663, KACC 10163 and KACC 10165) of P. chrysanthemi and Pectobacterium carotovorum subsp. carotovorum ATCC 15713.Large ISRs contained transfer RNA-Ile(tRNA$^{Ile}$)and tRNA$^{Ala}$, and small ISRs contained tRNA$^{Glu}$. Size of the small ISRs of P. chrysanthemi ranged on 354-356 bp, while it was 451 bp in small ISR of P. carotovorum subsp. carotovorum ATCC 15713. From hypervariable region of small ISRs, species-specific primer for P. chrysanthemi with 20 bp length (CHPG) was designed from hypervariable region of small ISRs, which was used as forward promer to detect P. chrysanthemi strains with R23-1R produced PCR product of about 260bp size (CHSF) only from P. chrysanthemi strains, not from other Pectobacterium spp. and Erwinia spp. Direct PCR from bacterial cell without extracting DNA successfully amplified a specific fragment, CHSF, from P. chrysanthemi ATCC 11663. The limit of PCR detection was 1${\pm}10^2$ cfu/ml.

• Journal of Communications and Networks
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• 제5권3호
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• pp.187-196
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• 2003

We consider the use of error control coding in direct sequence-code-division multiple access (OS-COMA) systems that employ multiuser detection (MUO) and space diversity. The relative performance gain between Reed-Solomon (RS) code and convolutional code (CC) is well known in [1] for the single user, additive white Gaussian noise (AWGN) channel. In this case, RS codes outperform CC's at high signal-to-noise ratios. We find that this is not the case for the multiuser interference channel mentioned above. For useful error rates, we find that soft-decision CC's to be uniformly better than RS codes when used with DS-COMA modulation in multiuser space-time channels. In our development, we use the Gaussian approximation on the interference to determine performance error bounds for systems with low number of users. Then, we check their accuracy in error rate estimation via system's simulation. These performance bounds will in turn allow us to consider a large number of users where we can estimate the gain in user-capacity due to channel coding. Lastly, the use of turbo codes is considered where it is shown that they offer a coding gain of 2.5 dB relative to soft-decision CC.

• 대한수의학회지
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• 제36권3호
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• pp.607-614
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• 1996

Several methods for rapid and accurate detection of VTe-producing E coli were established. These methods contain beta-glucuronidase-secretion test, beta-haemolysis-production test in blood agar, verocytotoxicity test, and PCR. All of the VTe-producing strains made beta-haemolysis on 5% sheep blood agar. VTe-producing strains secreted beta-glucuronidase whereas 0157:H7 strains producing VTI or VTII did not secrete that enzyme. Verocytotoxicity test was established for rapid diagnosis. VTe detection was rapider in Vero cell suspension than Vero cell monolayer. In PCR, there was a positive result only in VTe-producing E coli, not in VTI or VTII-producing E coli. In this experiment, 165 strains of E coli were islated from feces or intestinal contents of post-weaning piglets showing nervous sign or diarrhea. And 20 strains of E coli that produced VTe were selected by verocytotoxicity test and PCR. According to these experiments, there was a direct correlation between verocytotoxicity test and PCR. And verocytotoxicity test is recommended as a routine diagnostic method and PCR does as a accurate diagnostic method to detect VTe-producing E coli.

• 약학회지
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• 제41권1호
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• pp.74-80
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• 1997

A polygonal antibody against recombinant hirudin was raised for the development of a ELISA in biological fluids. Recombinant hirudin was conjugated to maleimide activated carrie r protein, KLH and injected to a rabbit. The third booster collection of antiserum was used as primary antibody for the ELISA. The titer for the detection antibody was determined. The direct ELISA could determine the concentration of hirudin in the range of ~10ng/ml. Affinity pulified IgG was obtained and conjugated to horseradish peroxidase. Purified IgG and IgG-HRP could be used as capture and detection antibody, respectively. Although sandwich ELISA would not give the satisfactory results. it could apply for the detection of hirudin level in the range of ~20 ${\mu}$g/ml.

• 전기학회논문지
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• 제67권8호
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• pp.1106-1112
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• 2018

In this paper, measurement techniques are presented to test the performance of insulation without interruption if it is difficult to measure insulation resistance. Especially, non-contact voltage phase detection techniques have been developed that can be applied in environments where it is difficult to find voltage measurement locations such as component receptors. The performance verification of the non-interrupting insulation resistance measuring devices has been tested against existing products using standard calibration equipment and test jigs. The validation confirmed performance within 2 % for direct contact type and within 10 % for non-contact type. In addition, the procedure to make continuous insulation test using the equipment was proposed.

• 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.