• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.176-181
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• 1979

Mercury and cadmium concentrations were analyzed for 112 brown rice samples collected from various production areas of Korea in 1976 and the results obtained were as follows: 1) Mercury concentrations were found in the range of non-detectable to 0.310 ppm, with an average of 0.053 ppm for the whole samples. Two samples from Kimpo area showed $5{\sim}6$ times higher concentrations than the average value. 2) Cadmium concentrations were found in range of trace to 0.029 ppm, with an average of 0.021 ppm for the whole samples. No specific site was found to be seriously contaminated by cadmium as far as the present survey was concerned.

• Journal of Sensor Science and Technology
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• v.7 no.4
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• pp.225-233
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• 1998

The principle, design, and application of a gear-tooth sensor for the rough environmental conditions such as high temperatures of up to $150^{\circ}C$ are studied. The rotation of a tooth wheel is detected by a couple of Hall elements manufactured on the SIMOX wafer by a methode of differential detection using bipolar silicon technology. The product sensitivity of the Hall element is about 510 V/AT over a wide temperature range of $-40^{\circ}C{\sim}150^{\circ}C$. The differential Hall sensor makes the maximum possible distance between sensor and tooth wheel wider than that when single Hall element is used over a wide temperature range, and the maximum detectable distance is 4.5mm at driving current of 4mA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.703-705
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• 2016

In this paper, we developed a wideband PIMD system to measure passive intermodulation distortion signals of mobile communication RF passive module. To represent wideband characteristic, we designed a receiver that meets low-noise and wideband characteristics in RF receiver. It allows high dynamic range in the RF receiver front end. In designed passive intermodulation distortion measurement system, we programed to display a PIMD signal with FPGA/DSP at PC. Implemented PIMD system was variable from 650 MHz to 2700 MHz and show up to -138 dB minimum detectable $3^{rd}$ passive inetrmodulation distortion signal.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1257-1267
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• 2023

Although rational genetic engineering is nowadays the favored method for microbial strain improvement, building up mutant libraries based on directed evolution for improvement is still in many cases the better option. In this regard, the demand for precise and efficient screening methods for mutants with high performance has stimulated the development of biosensor-based high-throughput screening strategies. Genetically encoded biosensors provide powerful tools to couple the desired phenotype to a detectable signal, such as fluorescence and growth rate. Herein, we review recent advances in engineering several classes of biosensors and their applications in directed evolution. Furthermore, we compare and discuss the screening advantages and limitations of two-component biosensors, transcription-factor-based biosensors, and RNA-based biosensors. Engineering these biosensors has focused mainly on modifying the expression level or structure of the biosensor components to optimize the dynamic range, specificity, and detection range. Finally, the applications of biosensors in the evolution of proteins, metabolic pathways, and genome-scale metabolic networks are described. This review provides potential guidance in the design of biosensors and their applications in improving the bioproduction of microbial cell factories through directed evolution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.256-260
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• 1999

Minimun-detectable levels to 28 antibacterial agents used for the prevention and the treatment of fish diseases were determined to establish optimal detective method of bioassay in fish by the EEC 4-plate method, the modified method of EEC 4-plate and the standard method of analysis in food safety regulation. The test organisms used in the methods of bioassay were as follows: Bacillus subtilis BGA (B. subtilis) and Micrococcus luteus ATCC 9341 (M. luteus) in the EEC 4-plate method, B. subtilis, M. luteus and Bacillus cereus var. mycoides ATCC 11778 (B. cereus) in the modified of EEC 4-plate, and B. subtilis, M. luteus, B. cereus and Bacillus stearothermophilis var. calidolactis C-953 (B. stearothermophilis) in the standard method. The standard method showed predominant sensitivity in the detection of penicillins (PCs), and was also highly sensitive to aminoglycosides (AGs). The sensitivity of standard method in the detection of tetracyclines (TCs), marrolides (MLs), nitrofuran derivatives(NFs) and quinolones (QNs) was very low, and against sulfonamides (SAs), however, was extremely low. The modified method of EEC 4-plate showed very high sensitivity to TCs. Both the EEC 4-plate and the modified method of EEC 4-plate showed competitively high sensitivity in the detection of PCs, MLs, NFs, QNs and SAs. All the methods studied in the experiment showed very low sensitivity against chloramphenicol (CMs). Consequently, the modified method of EEC 4-Plate was the best bioassay method with a wide range of sensitivity for the optimal detection of the residual antibacterial agents in fish.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.154-157
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• 2003

In order for testing faults of combinatorial logic circuit, the authors have developed a new diagnosis method: "Neural Network (NN) fault diagnosis", based on fm error back propagation functions. This method has proved the capability to test gate faults of wider range including so called SSA (single stuck-at) faults, without assuming neither any set of test data nor diagnosis dictionaries. In this paper, it is further shown that what kind of fault models can be detected in the NN fault diagnosis, and the simply modified one can extend to test delay faults, e.g. logic hazard as long as the delays are confined to those due to gates, not to signal lines.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.47-52
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• 2012

The use of a $Ti:LiNbO_3$ symmetric Mach-Zehnder interferometric intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of $46{\times}7{\times}1mm$ and operates at a wavelength of $1.3{\mu}m$. The output characteristic of the interferometer shows the modulation depth of 100% and 75%, and $V_{\pi}$ voltage of 6.6 V, and 6.6 V at the 200 Hz and 1 KHz, respectively. The minimum detectable electric field is ~1.84 V/m, ~3.28 V/m, and ~11.6 V/m, corresponding to a dynamic range of about ~22 dB, ~17 dB, and ~6 dB at frequencies of 500 KHz, 1 MHz and 5 MHz, respectively.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.45-47
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• 1957

A paper chromatographical method is studied to detect As and Sb from a mixed sample applying the principle of Gutzeit's. After spoting the mixed $AsH_3$ sample on the $AgNO_3$ band of paper strip (6 mm $\times$ 300 mm of Whatman No.52 or Toyo No.2 filter paper), the strip is developed by ascending method using N-HCl solution as a developing soluvent. The color spot detection of As and Sb is done by exposing the dried chromatogram to $H_2S$ stream. According to the experiments, the detectable minimum range of As is 3 micrograms and that of Sb is 15 micrograms. The yellow phosphorous interfers to the color spot detection of As and Sb, so that, previously the most of yellow phosphorous from the sample should be removed out.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.368-373
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• 2010

A new indoor mobile robot localization method is presented. Robot recognizes well designed single color landmarks on the ceiling by vision system, as reference to compute its precise position. The proposed likelihood prediction based method enables the robot to estimate its position based only on the orientation of landmark.The use of single color landmarks helps to reduce the complexity of the landmark structure and makes it easily detectable. Edge based optical flow is further used to compensate for some landmark recognition error. This technique is applicable for navigation in an unlimited sized indoor space. Prediction scheme and localization algorithm are proposed, and edge based optical flow and data fusing are presented. Experimental results show that the proposed method provides accurate estimation of the robot position with a localization error within a range of 5 cm and directional error less than 4 degrees.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.261-266
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• 1998

A method for the determination of noboviocin in milk was presented by high performance liquid chromatography(HPLC). The novobiocin in the spiked sample was extracted with methanol and evaporated under vacuum. After evaporating, the residue was mixed with distilled water for 2$m\ell$, filtrates with 0.45$\mu\textrm{m}$ acrodisc was injected into HPLC. The results obtained were as follows ; 1. The calibration curve of novobiocin was showed constantly linear(r 0.999) in the range of 100~500ng/$m\ell$. 2. The mean recovery rate of novobiocin from the spiked milk sample were 88~98%. 3. The coefficients of variation were 2.6~5.8% 4. The lowest detectable limit of novobiocin was 25ppb.