• Journal of the Korean Electrochemical Society
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• v.23 no.3
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• pp.66-72
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• 2020

In this study, the development of biosensors capable of bi-enzyme reactions by including Horseradish peroxidase and glucose oxidase was carried out for detection of glucose. The sensors were manufactured using electro deposition method to reduce production time, and screen printed electrodes (SPE) were used to produce economical sensors. To check the bienzyme effect, the sensor was compared and analyzed with single enzyme biosensor. The characteristics of the sensor were evaluated using scanning electron microscopy(SEM), cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS), chronoamperometry(CA), and flow injection analysis(FIA). Analysis results from SEM, CV and EIS confirmed that the enzymes are well fixed to the electrode surface. In addition, it was confirmed that bi-enzyme biosensors manufactured from the CA method improved signal performance by 200% compared to single enzyme biosensors. From this results, we were able to explain that HRP and GOD react catalyzed to each other. And the results of FIA showed that the intensity of each current signal was constant when the same concentration of glucose was injected four times. In addition, by analyzing the intensity of current signals for glucose concentrations, the biosensors manufactured in this study showed excellent trends in signal sensitivity, reproducibility and stability.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.238-247
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• 2014

The milking robot system is very important to detect correctly the teats position in the moving condition of cow. Also, the robot manipulator must control tracking the teat cup to the detected teat position. The presented milking robot is designed using the one point laser sensor for teat position detection. The teats of cow are detected by the laser scanning unit and the manipulator has the function of 3 axes moving control unit. The presented teat detection method and the electrical driving manipulator have the advantages of a simple, low cost and very quiet. The designed manipulator is realized by the totally electrical motor and servo poison control algorithm with velocity PID compensation. The presented robot is realized using the teat detection unit, 4 teat cups, 3 axes robot arm, 6 servo motors and automatic milking control line. The designed robot is experimented in the cow farm and is satisfied with the designed performance specification for milking robot manipulator.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.409-414
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• 1998

To examine the detectability of the aerosol and/or Yellow dust from China crossing over the Yellow sea, three works carried out as follows , Firstly, a comparison was made of the visible(VIS), water vapor(WV), and Infrared(IR) images of the GMS-5 and NOAA/AVHRR on the cases of yellow sand event over Korea. Secondly, the spectral radiance and reflectance(%) was observed during the yellow sand phenomena on April, 1998 in Seoul using the GER-2600 spectroradiometer, which observed the reflected radiance from 350 to 2500 nm in the atmosphere. We selected the optimum wavelength for detecting of the yellow sand from this observation, considering the effects of atmospheric absorption. Finally, the atmospheric radiance emerging from the LOWTRAN-7 radiative transfer model was simulated with and without yellow sand, where we used the estimated aerosol column optical depth ($\tau$ 673 nm) in the Meteorological Research Institute and the d'Almeida's statistical atmospheric aerosol radiative characteristics. The image analysis showed that it was very difficult to detect the yellow sand region only by the image processing because the albedo characteristics of the sand vary irregularly according to the density, size, components and depth of the yellow sand clouds. We found that the 670-680 nm band was useful to simulate aerosol characteristics considering the absorption band from the radiance observation. We are now processing the simulation of atmospheric radiance distribution in the range of 400-900 nm. The purpose of this study is to present the preliminary results of the aerosol and/or Yellow dust detectability using the Ocean Scanning Multispectral Imager(OSMI), which will be mounted on KOMPSAT-1 as the ocean color monitoring sensor with the range of 400-900 nm wavelength.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.43-48
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• 1998

Prior to launch, simulated radiances of the Ocean Scanning Multispectral Imager (OSMI) will be very useful to guess the real imagery of OSMI and to check the data processing system for OSMI. The data processing system for OSMI which is one sensor of Korea Mult i - Purpose Satellite (KOMPSAT) scheduled for launch in 1999 is being developed based on the SeaWiFS Data Analysis System (SeaDAS). Such a simulation should include the spectral bands, orbital and scanning characteristics of the OSMI and KOMPSAT spacecraft. The simulation is also very helpful for finding and preparing for problem areas before launch. This paper describes a method to create simulated radiances of the OSMI over the oceans. Our method for constructing a simulated OSMI imagery is to propagate a KOMPSAT orbit over a field of Coastal Zone Color Scanner (CZCS) pigment values and to use the values and atmospheric components to calculate total radiances. A modified Brouwer - Lyddane model with drag was used for the realistic orbit prediction, the CZCS pigment data were used to compute water - leaving radiances, and a variety of radiative transfer models were used to calculate atmospheric contributions to total radiances detected by OSMI. Imagery of the simulated OSMI total radiances for 6 nominal bands was obtained. As expected, water - leaving radiances were only a small fraction of total radiances and sun glint contaminations were observed near the solar declination. Therefore, atmospheric correction is very important in the calculation of pigment concentration from total radiances. Because the imagery near the sun's glitter pattern is virtually useless and must be discarded, more advanced mission planning will be required.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.82-89
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• 2011

Ruthenium(Ru)-doped $TiO_2$ nanofibers were prepared using electrospun Ru-$TiO_2$/poly(vinyl acetate) (PVAc) fibers and subsequent annealing for 1 h at temperatures in the range of $500^{\circ}C$ to $1000^{\circ}C$ in air. The properties of the Ru-$TiO_2$ fibers were characterized as a function of the Ru content and calcination temperature using X-ray diffraction, thermal gravimetry with differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and viscometer, pycnometer and dynamic tensiometer measurements. Although the diameter of the fiber decreased slightly with increasing calcination temperature, no dramatic changes were observed with respect to the ruthenium content. The XRD and FT-IR results revealed that anatase phase and ruthenium metal began to be formed after calcination at temperatures above $500^{\circ}C$. Anatase and rutile phases and ruthenium metal coexisted in the fibers calcined above $600^{\circ}C$. No anatase phase was detected in the fibers containing ruthenium when they were calcined at $1000^{\circ}C$. The morphology of the fibers changed from smooth and uniform to porous with increasing temperature. The experimental results suggest that the calcination temperature and Ru content were influential in determining the morphology and structure of the fibers.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.175-180
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• 2009

In this article, we fabricated polytetrafluoroethylene(PTFE) nozzle treated by ion beam, in order to fabricate polymer based electrospray micro thruster with super hydrophobic nozzle. To obtain the super hydrophobic surface, PTFE surface is treated by argon and oxygen plasma treatment process. The optimal condition is investigated argon and oxygen flow rate as well as the paalied energy level for the treatment process. Fabricated nozzle was evaluated by measuring contact angle, and the surface morphology was examined by using scanning electron microscope(SEM) and atomic force microscope(AFM). We observe that jetting becomes more stable and repeatable on the treated nozzle. And to evaluate performance of fabricated nozzle, we measure micro scale thrust using a cantilever and a nozzle treated by ion beam laser displacement sensor.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.693-703
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• 2019

Long-term coastal topographical data is critical for analyzing temporal and spatial changes in shorelines. Especially understanding the change trends is essential for future coastal management. For this research, in the data preparation, we obtained digital aerial images, terrestrial laser scanning data and UAV images in the year of 2009. 2018 and 2019 respectively. Also tidal observation data obtained by the Korea Hydrographic and Oceanographic Agency were used for Bangamoeri beach located in Ansan, Gyeonggi-do. In the process of it, we applied the photogrammetric technique to extract the coastline of 4.40 m from the stereo images of 2009 by stereoscopic viewing. In 2018, digital elevation model was generated by using the raw data obtained from the laser scanner and the corresponding shoreline was semi-automatically extracted. In 2019, a digital elevation model was generated from the drone images to extract the coastline. Finally the change rate of shorelines was calculated using Digital Shoreline Analysis System. Also qualitative analysis was presented.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.332-332
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• 2022

적설은 지구 기후시스템과 수문순환 과정에서 중요한 역할을 하고 있으며, 겨울철의 적설은 봄철에 녹으면서 식생과 수자원 제공에 큰 영향을 주는 인자로 알려져 있다. 동아시아가 위치한 북반구는 적설량의 90%가 관찰되고 토지의 약 42%가 긴 시간동안 눈으로 덮여 있어 지표 에너지와 물 균형에 영향을 주고, 특히 수자원 관리를 위한 유출이나 토양수분과 같은 수문 인자에 큰 영향을 미친다. 따라서 적설을 정확하게 예측하는 것은 수자원 관리에 있어 매우 중요한 일이다. 한편, 이러한 수문 순환을 정확히 예측하기 위해 수문 분야에서는 지면모형(Land Surface Model, LSM)을 많이 사용하고 있다. 지면모형은 지표면과 대기 사이의 상호작용을 모의하기 위해 개발되었고, 에너지, 수증기, 이산화탄소 등의 다양한 인자들의 교환에 대하여 해석하며, 토양수분, 유출량 등의 수자원 분야의 주요 인자들을 산출하여 수자원 관리에 적극적으로 활용되고 있다. 이에 본 연구에서는 National Center for Atmospheric Research(NCAR)에서 개발한 Community Land Model(CLM)을 사용하여 2001년부터 2016년까지 25km의 공간해상도로 동아시아 지역의 적설 모의를 평가하였다. CLM의 적설 모의 평가 인자는 Snow depth, Snow water equivalent의 2가지 인자를 대상으로 수행하였고, 모의 성능 평가를 위한 관측 자료로 NASA Aqua와 JAXA GCOM-W1 위성에 탑재된 Advanced Microwave Scanning Radiometer(AMSR) 센서에서 제공하는 위성 관측 자료와 Defense Meteorological Satellite Program(DMSP) 위성의 Special Sensor Microwave/Imager(SSM/I) 센서와 Nimbus-7 위성의 Scanning Multichannel Microwave Radiometer(SMMR) 센서에서 제공하는 위성 관측 자료를 기반으로 지상 기상 관측소 자료와 조합하여 재생성한 European Space Agency Global Snow Monitoring for Climate Research (ESA GlobSnow)의 자료를 사용하였다. 그 결과 CLM의 적설 모의는 과대 추정하는 것을 알 수 있었으며, 본 연구의 결과는 동아시아 적설 모의 개선을 위해 자료 동화를 사용하는 후속 연구의 기초자료로 사용할 수 있다.

• Korean Journal of Remote Sensing
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• v.12 no.1
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• pp.1-16
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• 1996

Korea Aerospace Research Institute(KARI) is developing a Korea Multi-Purpose Satellite I(KOMPSAT-I) which accommodates Electro-Optical Camera(EOC), Ocean Color Imager(OCI), Space Physics Sensor(SPS) for cartography, ocean color monitoring, and space environment monitoring respectively. The satellite has the weight of about 500 kg and is operated on the sun synchronized orbit with the altitude of 685km, the orbit period of 98 minutes, and the orbit revisit time of 28days. The satellite will be launched in the third quarter of 1999 and its lifetime is more than 3 years. EOC has cartography mission to provide images for the production of scale maps, including digital elevation models, of Korea from a remote earth view in the KOMPSAT orbit. EOC collects panchromatic imagery with the ground sample distance(GSD) of 6.6m and the swath width of 15km at nadir through the visible spectral band of 510-730 nm. EOC scans the ground track of 800km per orbit by push-broom and body pointed method. OCI mission is worldwide ocean color monitoring for the study of biological oceanography. OCI is a multispectral imager generating 6 color ocean images with and <1km GSD by whisk-broom scanning method. OCI is designed to provide on-orbit spectral band selectability in the spectral range from 400nm to 900nm. The color images are collected through 6 primary spectral bands centered at 443, 490, 510, 555, 670, 865nm or 6 spectral bands selected in the spectral range via ground commands after launch. SPS consists of High Energy Particle Detector(HEPD) and Ionosphere Measurement Sensor(IMS). HEPD has mission to characterize the low altitude high energy particle environment and to study the effects of radiation environment on microelectronics. IMS measures densities and temperature of electrons in the ionosphere and monitors the ionospheric irregularities in KOMPSAT orbit.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.3-12
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• 2016

Bluetooth Low Energy (BLE) protocol has attracted attention as a promising technology for low data throughput and low energy wireless sensor networks. Fast device discovery is very important in a BLE based wireless network. It is necessary to configure the network to work with minimized energy consumption because the BLE network nodes are expected to operate a long time typically on a coin cell battery. However, since it is difficult to obtain low energy and low latency at the same time, the BLE standard introduces wide range setting of parameters related to device discovery process and let the network operators to set up parameter values for the application. Therefore, it is necessary to analyze the performance of device discovery according to the related parameter values prior to BLE network operation. In this paper we analyze the expected value and the cumulative distribution function of the number of advertisements for device discovery in the BLE network. In addition, we propose a scheme for controlling the interval between advertising events that can improve the performance of device discovery without increasing energy consumption.