• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.3
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• pp.54-61
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• 2003

$SnO_2$ gas sensor for the detection DMMP, simulant of nerve gas was fabricated and its characteristics were examined. Sensing materials were $SnO_2$ added by TEX>$\alpha$-$Al_{2}O_{3}$ with 0∼20wt.% and $In_{2}O_{3}$ with 0∼3wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Its dimension was 7$\times$10$\times$0.6$\textrm{mm}^2$. Crystallite size 8t phase identification, specific surface area and morphology of fabricated $SnO_2$ powders were analyzed by X-ray diffraction(XRD), surface area analyzer(BET) and by a scanning electron microscope(SEM), respectively. Sensor was measured as flow type and sensor resistance change was monitored as real time using LabVIEW program. The best sensitivities were 75% at adding 4wt.% TEX>$\alpha$-$Al_{2}O_{3}$, operating temperature $300^{\circ}C$ and 87% at adding 2wt.% $In_{2}O_{3}$, operating temperature $350^{\circ}C$ to DMMP 0.5ppm. Response and recovery times were about 1 and 3 min., respectively. Repetition measurement was very good with $\pm$3% in full scale. As a result, operating temperature was lower TEX>$\alpha$-$Al_{2}O_{3}$ than $In_{2}O_{3}$, but sensitivity was higher $In_{2}O_{3}$ than $\alpha$-$Al_{2}O_{3}$.

• Journal of the Korean Society of Tobacco Science
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• v.35 no.1
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• pp.20-27
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• 2013

An Electronic Nose(E-Nose) and Gas Chromatography/Mass Spectroscopy (GC/MS) are meanwhile conventional technique to analyze volatile materials in many industries (e.g., food, medicine, environment) and have broad acceptance in the analysis of tobacco products. In this study, an experiment where tin oxide gas sensor array responses and GC/MS profiles are used to characterize the volatile compounds of different cigarettes at the same time is performed and the measurements of two instruments are compared for cigarette samples with a known chemical information. E-Nose and GC/MS were employed to differentiate and match flavored cigarettes with commercial tobacco flavoring agents (lavender, vanilla, peppermint, orange, star anise). For verifying reliability of two systems, the analyses were conducted in terms of amount of flavors in each cigarettes using partial least squares (PLS) and with the principal components analysis (PCA). Various chemical sensors and GC/MS data was reduced into two principal factors (PC1, PC2) for being distinguished with visualized regions. Both systems provided adequate results for odor characteristics of cigarettes in this study with each instrument having its own advantages and disadvantages.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.184-188
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• 2016

Highly ordered $SnO_2$ and NiO nanocolumns have been successfully achieved by glancing-angle deposition (GLAD) using an electron beam evaporator. Nanocolumnar $SnO_2$ and NiO sensors exhibited high performance owing to the porous nanostructural effect with the formation of a double Schottky junction and high surface-to-volume ratios. When all gas sensors were exposed to various gases such as $C_2H_5OH$, $C_6H_6$, and $CH_3COCH_3$, the response of the highly ordered $SnO_2$ nanocolumn were over 50 times higher than that of the $SnO_2$ thin film. This work will bring broad interest and create a strong impact in many different fields owing to its particularly simple and reliable fabrication process.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.40-48
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• 2010

Reflected-Ultraviolet photography is applied to the evidence of crime, Archaeology, and Dermatology. In the past, Ultraviolet photography was done with standard black-and-white film. Because emulsion of film is more sensitive to near UV light than CCD(Charge Coupled Device) or CMOS(Complementary Metal-Oxide-Semiconductor)of digital camera. In this research, we purpose to improve qulity of ultraviolet photographs and to find out the best alternative digital camera by utilizing a cunsumer digital camera. To achieve theses, we removed IR cutoff filter from digital camera. And by using modified UV pass filter, we verified the increase of image resolution of digital ultraviolet photographs. Also, we analyze reproducibility of digital ultraviolet photographs according to type, size, pixel of image sensor. Furthermore, this research resulted in the development of an practical digital camera system by utilizing a cunsumer digital camera. Eventually, it will contribute to practical use in the various field of digital ultraviolet photographs

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.262-266
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• 2011

A simulation study of a current-mode direct current (DC)-DC boost converter is presented in this paper. This converter, with a fully-integrated power module, is implemented by using bipolar complementary metal-oxide semiconductor (BiCMOS) technology. The current-sensing circuit has an op-amp to achieve high accuracy. With the sense metal-oxide semiconductor field-effect transistor (MOSFET) in the current sensor, the sensed inductor current with the internal ramp signal can be used for feedback control. In addition, BiCMOS technology is applied to the converter, for accurate current sensing and low power consumption. The DC-DC converter is designed with a standard 0.35 ${\mu}m$ BiCMOS process. The off-chip inductor-capacitor (LC) filter is operated with an inductance of 1 mH and a capacitance of 12.5 nF. Simulation results show the high performance of the current-sensing circuit and the validity of the BiCMOS converter. The output voltage is found to be 4.1 V with a ripple ratio of 1.5% at the duty ratio of 0.3. The sensing current is measured to be within 1 mA and follows to fit the order of the aspect ratio, between sensing and power FET.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.541-546
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• 1998

Volatile flavor components in leaf and petiole of fresh Pleurospermum kamtschaticum H$\_$OFFM/ were extracted by SDE (simultaneous steam distillation and extraction) method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Identification of volatile flavor components was based on the Rl of GC and mass spectrum of GC-MS. A total of 31 components, including 15 hydrocarbons, 4 aldehydes, 1 ketone, 5 alcohols, 2 esters, 3 acids and 1 oxide were identified in the essential oils. (Z)-${\beta}$-Farnesene, (Z, E)-${\alpha}$-farnesene and farnesene were the major volatile flavor components in fresh Pleurospermum kamtschaticum. Volatile flavor patterns of Pleurospermum kamtschaticum were analyzed using electronic nose. Sensor T30/1 and PA2 that were sensitive to alcohols had the highest resistance for fresh Pleurospermum kamtschaticum. Resistance of six metal oxide sensors was decreased in dried sample compared with fresh one.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1178-1184
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• 2015

In conventional robotics, charge-coupled device (CCD) and complementary metal-oxide-semiconductor (CMOS) cameras have been utilized for acquiring vision information. These devices have problems, such as narrow optic angles and inefficiencies in visual information processing. Recently, biomimetic vision sensors for robotic applications have been receiving much attention. These sensors are more efficient than conventional vision sensors in terms of the optic angle, power consumption, dynamic range, and redundancy suppression. This paper presents recent research trends on biomimetic vision sensors and discusses future directions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.77-85
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• 2009

In this paper, we propose data format for smell, taste, touch with speech and vision which can be transmitted and implement a floral scent detection and recognition system. We provide representation method of data of smell, taste, and touch. Also, proposed floral scent recognition system consists of three module such as floral scent acquisition module using Metal Oxide Semiconductor (MOS) sensor array, entropy-based floral scent detection module, and floral scent recognition module using correlation coefficients. The proposed system calculates correlation coefficients of the individual sensor between feature vector(16 sensors) from floral scent input point until the stable region and 12 types of reference models. Then, this system selects the floral scent with the maximum similarity to the calculated average of individual correlation coefficients. To evaluate the floral scent recognition system using correlation coefficients, we implemented an individual floral scent recognition system using K-NN with PCA and LDA that are generally used in conventional electronic noses. In the experimental results, the proposed system performs approximately 95.7% average recognition rate.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.51-58
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• 2010

This paper proposes an edge adaptive color interpolation for an ultra-small HD-grade complementary metal-oxide semiconductor (CMOS) video sensor in camera phones that can process 720-p/30-fps videos. Recently, proposed methods with great image quality perceptually reconstruct the green component and then estimate the red/blue component using the reconstructed green and neighbor red and blue pixels. However, these methods require the bulky memory line buffers in order to temporally store the reconstructed green components. The edge adaptive color interpolation method uses seven or nine patterns to calculate the six edge directions. At the same time, the threshold values are adaptively adjusted by the sum of the color values of the selected pixels. This method selects the suitable one among the patterns using two flowcharts proposed in this paper, and then interpolates the missing color values. For verification, we calculated the peak-signal-to-noise-ratio (PSNR) in the test images, which were processed by the proposed algorithm, and compared the calculated PSNR of the existing methods. The proposed color interpolation is also fabricated with the 0.18-${\mu}m$ CMOS flash memory process.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3076-3083
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• 2024

In this work, single photon avalanche diodes (SPADs) were fabricated using the standard 180 nm complementary metal-oxide semiconductor process. Their small size of 15-16 µ m and low operating voltage made it possible to easily integrate them with readout circuits for compact on-chip sensors, particularly those used in the radiation sensor network of a nuclear plant. Four architectures were proposed for the SPADs, with a shallow trench isolation (STI) guard ring and different depletion regions designed to demonstrate the main performance parameters in each experimental configuration. The wide absorption region structure with PSD and a deep N-well could achieve a uniform electric field, resulting in a stable dark count rate (DCR). Additionally, the STI guard ring was implanted to mitigate the premature edge breakdown. A breakdown voltage was achieved for a low operating voltage of 10.75 V. The DCR results showed 286.3 Hz per ㎛² at an excess voltage of 0.04 V. A photon detection probability of 21.48% was obtained at 405 nm.