• Analytical Science and Technology
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• v.6 no.4
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• pp.411-415
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• 1993

A method for UV labeling of fatty acids with 2-bromoacetyltriphenylene using 18-crown-6-ether as a catalyst is described. The procedure is rapid, simple, quantitative and applicable to the HPLC analysis of fatty acids with UV detector. They have high molar absorptivity and their detection limit was about 1ng level. Nine derivatives of saturated fatty acid($C_{12}-C_{22}$) were separated on reverse-phase column(${\mu}$-Bondapak C-18) using acetonitrile-water gradient.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.3
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• pp.37-41
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• 2018

This paper presents the integrated fluorescent oxygen sensor probe module based on planner lightwave circuits using UV imprint lithography. The oxygen sensor system is consisted of the optical source part, optical detector part and optical sensing probe part to be composed of the planner lightwave circuit and oxygen sensitive thin film layer. Firstly, we optimally designed the planner lightwave circuit with asymmetric $1{\times}2$ beam splitter using beam propagation method. Then, we fabricated the planner lightwave circuits using UV imprint lithography process. This planner lightwave circuits transmitted the optical power with 76% efficiency and the fluorescence signal with 70% efficiency. The oxygen sensitive thin film layer is coated on the end face of planner lightwave circuit. The oxygen sensor system using this sensor probe module with planner lightwave circuit could measure the concentration with 0.3% resolution from 0% to 20% gas range. This optical oxygen sensor probe module make it possible to compact, simple and cheap measurement system.

• Proceedings of the Optical Society of Korea Conference
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• 1990.07a
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• pp.78-86
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• 1990

• Analytical Science and Technology
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• v.11 no.2
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• pp.96-104
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• 1998

A photodiode array multichannel detector system for capillary electrophoresis was developed. The photodiode array detector for capillary electrophoresis (CE-PDA) has 1024 photodetectors and can analyze sample by measuring UV/VIS absorption spectrum in 275~675 nm wavelength range. The CE-PDA instrument can get a spectrum in 30 ms during sample separation and can be programmed by a PC to control various experimental conditions required for sample analysis. The performance of the multichannel CE-PDA instrument was tested using L-ascorbic acid and alizarin yellow GG mixture. The reproducibility test of the CE-PDA system showed 5.6% RSD.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.542-550
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• 2019

To detect Escherichia coli from agri-food and production environments, a device based on IoT (internet of things) technology that can check test results in real time on a mobile phone has been developed. The efficiency of the developed device, which combines an incubator equipped with a UV lamp, a high-resolution camera and software to detect E. coli in the field, was evaluated by measuring the device's temperature, detection limit, and detection time. The device showed a difference between its programmed temperature setting and actual temperature of about 1.0℃. In a detection limit test performed with a single-colony inoculation, a color change to yellow and a florescent signal were detected after 12 and 15 h incubations, respectively. The incubation time also decreased along with increasing bacteria levels. When applying the developed method and device to various samples, including utensils, gloves, irrigation water, seeds, and vegetables, detection rates of E. coli using the device were higher than those of the Korean Food Code method. These results show that the developed protocol and device can efficiently detect E. coli from agri-food production environments and vegetables.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.503-510
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• 2006

Readout circuit is to convert signal occurred in a defector into suitable signal for image signal processing. In general, it has to possess functions of impedance matching with perception element, amplification, noise reduction and cell selection. It also should satisfies conditions of low-power, low-noise, linearity, uniformity, dynamic range, excellent frequency-response characteristic, and so on. The technical issues in developing image processing equipment for focal plane way (FPA) can be categorized as follow: First, ultraviolet (UV) my detector material and fine processing technology. Second, ReadOut IC (ROIC) design technology to process electric signal from detector. Last, package technology for hybrid bonding between detector and ROIC. ROIC enables intelligence and multi-function of image equipment. It is a core component for high value added commercialization ultimately. Especially, in development of high-resolution image equipment ROIC, it is necessary that high-integrated and low-power circuit design technology satisfied with design specifications such as detector characteristic, signal dynamic range, readout rate, noise characteristic, ceil pitch, power consumption and so on. In this paper, we implemented a $8\times8$ FPA prototype ROIC for reduction of period and cost. We tested unit block and overall functions of designed $8\times8$ FPA ROIC. Also, we manufactured ROIC control and image boards, and then were able to verify operation of ROIC by confirming detected image from PC's monitor through UART(Universal Asynchronous Receiver Transmitter) communication.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.12
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• pp.806-811
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• 2017

An all-transparent ultraviolet (UV) photodetector was fabricated by structuring $p-NiO/n-SnO_2/ITO$ on a glass substrate. $SnO_2$ is an important semiconductor material because of its large bandgap, high electron mobility, high transmittance (as high as 80% in the visible range), and high stability under UV light. For these reasons, $SnO_2$ is suitable for a range of applications that involve UV light. In order to form a highly transparent p-n junction for UV detection, $SnO_2$ was deposited onto a device containing NiO as a high-transparent metal conductive oxide for UV detection. We demonstrated that all-transparent UV photodetectors based on $SnO_2$ could provide a definitive photocurrent density of $4nA\;cm^{-2}$ at 0 V under UV light (365 nm) and a low saturation current density of $2.02nA{\times}cm^{-2}$. The device under UV light displayed fast photoresponse with times of 31.69 ms (rise-time) and 35.12 ms (fall-time) and a remarkable photoresponse ratio of 69.37. We analyzed the optical and electrical properties of the $NiO/SnO_2$ device. We demonstrated that the excellent properties of $SnO_2$ are valuable in transparent photoelectric device applications, which can suggest various routes for improving the performance of such devices.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.667-670
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• 2020

최근에는 증강현실, 로봇공학 등의 분야에서 객체의 위치 검출 이외에도, 객체의 자세에 대한 추정이 요구되고 있다. 객체의 자세 정보가 포함된 데이터셋은 위치 정보만 포함된 데이터셋에 비하여 상대적으로 매우 적기 때문에 인공 신경망 구조를 활용하기 어려운 측면이 있으나, 최근에 들어서는 기계학습 기반의 자세 추정 알고리즘들이 여럿 등장하고 있다. 본 논문에서는 이 가운데 Dense 6d Pose Object detector (DPOD) [11]의 구조를 기반으로 하여 가구의 조립 설명서에 그려진 가구 부품들의 자세를 추정하고자 한다. DPOD [11]는 입력으로 RGB 영상을 받으며, 해당 영상에서 자세를 추정하고자 하는 객체의 영역에 해당하는 픽셀들을 추정하고, 객체의 영역에 해당되는 각 픽셀에서 해당 객체의 3D 모델의 UV map 값을 추정한다. 이렇게 픽셀 개수만큼의 2D - 3D 대응이 생성된 이후에는, RANSAC과 PnP 알고리즘을 통해 RGB 영상에서의 객체와 객체의 3D 모델 간의 변환 관계 행렬이 구해지게 된다. 본 논문에서는 사전에 정해진 24개의 자세 후보들을 기반으로 가구 부품의 3D 모델을 2D에 투영한 RGB 영상들로 인공 신경망을 학습하였으며, 평가 시에는 실제 조립 설명서에서의 가구 부품의 자세를 추정하였다. 실험 결과 IKEA의 Stefan 의자 조립 설명서에 대하여 100%의 ADD score를 얻었으며, 추정 자세가 자세 후보군 중 정답 자세에 가장 근접한 경우를 정답으로 평가했을 때 100%의 정답률을 얻었다. 제안하는 신경망을 사용하였을 때, 가구 조립 설명서에서 가구 부품의 위치를 찾는 객체 검출기(object detection network)와, 각 개체의 종류를 구분하는 객체 리트리벌 네트워크(retrieval network)를 함께 사용하여 최종적으로 가구 부품의 자세를 추정할 수 있다.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.442-450
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• 2014

Concern has grown over a presence of micropollutants in natural water since sulfonamide antibiotic substances such as sulfamethazine, sulfamethoxazole, sulfathiazole have been frequently detected in Nakdong River, Korea. The current work investigates the degradation of the three sulfonamide substances by using quantum chemistry calculations of density functional theory (DFT) and experimental measurement techniques of Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometer (UV-VIS). DFT calculations demonstrate that the lowest energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbitals (LUMO) lies in sulfanilamide functional group of sulfonamide, implying that the sulfanilamide functional group would be the most active site for ozone oxidation. Also, UV-VIS spectra and FT-IR analysis reveal that 260 nm band originated from sulfanilamide group was absent after ozone oxidation, indicating that a functional group of amine (N-H) was removed from sulfanilamide. Both theoretical and experimental observations agree well with each other, demonstrating the DFT calculation tool can be an alternative tool for the prediction of chemical reactions in purification treatment processes.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.817-820
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• 2001

본 논문에서는 섬광탄 (flare)과 같은 공중 표적(target)의 대응 능력 (CM; countermeasure) 에 효과적으로 대처할 수 있는 2-color 탐색기의 반대응 (CCM; counter-countermeasure) 알고리듬을 제안하고자 한다. 자외선 (UV) 및 적외선 (IR) 대역을 동시에 이용하는 2-color 탐색기는 표적과 섬광탄의 방사에너지 특성을 적외선 및 자외선 대역에서 비교, 분석하여 대역별 특성을 결정한다. 이러한 특성을 이용하여 두 대역의 입력 신호로부터 효과적으로 표적 신호만을 검출, 추적함을 보인다. 또한 제안된 2-color 방식을 로젯 주사 탐색기(rosette scan seeker)의 반대응 능력으 펄 이용하여 동적 시뮬레이션을 수행한다.