• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1107-1112
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• 2016

This study is the Smart Office features that take advantage of KEPCO eIoT(: energy Internet of Thing) platform, and it's Network configuration is composed of sensing device, gateway, platform, and the service server. The key features are parts for processing protocol data between the gateway and the device using LoRa(: Long Range) technology, Intelligent applications and public safety data connected to the PS-LTE(: Public Safety-Long-Term Evolution) system. And the resource tree provided Smart Office for the service, which commonly used in the application server and the device.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.195-200
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• 2008

The accuracy of classifying pixels in HIRIS images is usually degraded by noisy bands since noisy bands may deform the typical shape of spectral reflectance. Proposed in this paper is a statistical method for noisy band removal which mainly makes use of the correlation coefficients between bands. Considering each band as a random variable, the correlation coefficient measures the strength and direction of a linear relationship between two random variables. While the correlation between two signal bands is high, existence of a noisy band will produce a low correlation due to ill-correlativeness and undirectedness. The application of the correlation coefficient as a measure for detecting noisy bands is under a two-pass screening scheme. This method is independent of the prior knowledge of the sensor or the cause resulted in the noise. The classification in this experiment uses the unsupervised k-nearest neighbor algorithm in accordance with the well-accepted Euclidean distance measure and the spectral angle mapper measure. This paper also proposes a hierarchical combination of these measures for spectral matching. Finally, a separability assessment based on the between-class and within-class scatter matrices is followed to evaluate the performance.

• Journal of Magnetics
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• v.19 no.2
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• pp.151-154
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• 2014

Recent years have seen an increasing range of planar Hall resistive (PHR) sensor applications in the field of magnetic sensing. This study describes a new application of the PHR sensor to monitor a current. Initially, thermal drift experiments of the PHR sensor are performed, to determine the accuracy of the PHR signal output. The results of the thermal drift experiments show that there is no considerable drift in the signals attained from 0.1, 0.5, 1 and 2 mA current. Consequently, the PHR sensor provides adequate accuracy of the signal output, to perform the current monitoring experiments. The performances of the PHR sensor with bilayer and trilayer structures are then tested. The minimum detectable currents of the PHR sensor using bilayer and trilayer structures are $0.51{\mu}A$ and 54 nA, respectively. Therefore, the PHR sensor having trilayer structure is the better choice to detect ultra low current of few tens nanoampere.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.845-846
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• 2006

In this paper, we describe a capacitive position sensing and motion control scheme of a MEMS scanner used for laser display application. The laser displays can be made by scanning laser beams much the same way a CRT scans electron beams. So the accuracy of the scanner motion determines the quality of the displayed image. The MEMS scanner under consideration is composed of electrostatic comb electrodes with initial gap and requires large driving voltage. Due to the under-damping and nonlinear driving characteristics, the scanner motion is subject to be an unwanted oscillation. For the linear scanner motion, we devise a differential charge amplifier and phase compensator. The experimental results show that the implemented feedback control system provides sufficient electrical damping and improves the dynamic performance of the scanner.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.287-292
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• 2003

The ability of robot is being various and complex. The robot is utilizing distance, image data and voice data for sensing its circumstance. This paper suggests the 2-layer fuzzy control as the algorithm that control robot with various sensor information. In a obstacle avoidance, it utilizes many range finders and classifies them into 3parts(front, left, right). In 3 sub-controllers, the controller executes fuzzy conference. And then it executes combined control with a combination of outputs of 3 sub-controllers in the second step. The text compares the 2-layer fuzzy controller with the hierarchical fuzzy controller that has analogous structure. And the performance of the 2-layer fuzzy controller is confirmed by application this controller to robot following, simulation to each other and real experiment.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.103-108
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• 2012

Radiofrequency(RF) signal is a key medium to the most of the present wireless communication devices including RF identification devices(RFID) and smart sensors. However, the most critical barrier to overcome in RFID application is in the failure rate in detection. The most notable improvement in the detection was from the introduction of EPC Class1 Gen2 protocol, but the fundamental problems in the physical properties of the RF signal drew less attention. In this work, we focused on the physical properties of the RF signal in order to understand the failure rate by noting the existence of the ground planes and noise sources in the real environment. By using the mathematical computation software, Maple, we simulated the distribution of the electromagnetic field from a dipole antenna when ground planes exist. Calculations showed that the dark area can be formed by interference. We also constructed a test system to measure the failure rate in the detection of a RFID transponder. The test system was composed of a fixed RFID reader and an EPC Class1 Gen2 transponder which was attached to a scanner to sweep in the x-y plane. Labview software was used to control the x-y scanner and to acquire data. Tests in the laboratory environment showed that the dark area can be as much as 43 %. One who wants to use RFID and smart sensors should carefully consider the extent of the dark area.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.347-351
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• 2002

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Terra and Aqua satellites, launched in 1999 and 2002, is directly received by Korea Aerospace Research Institute (KARI) ground station facility. BURI engineers develop a system to receive direct broadcast downlink from MODIS to provide near-realtime, remotely-sensed, spaceborne data to the user community in Korea. MODIS scans a swath width of 2330 km that is sufficiently wide to cover Korean peninsular, Yellow and East Sea at once. The MODIS has 36 spectral bands between 0.415 fm and 14.235 $\mu$m, i.e. through the visible into the thermal infrared. MODIS has been observed active fires, floods, smoke transport, dust storms, severe storms since February of 2000. The KARI is preparing for distribution of direct broadcasted MODIS data to users in Korea. The MODIS database system will be designed and developed by KARI engineer for data service from year of 2003. MODIS data user group will be organized from $\.{O}$ctober to December 2002.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.759-762
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• 2005

Recently, Intelligent Transportation System(ITS) has been applied to satisfy increasing traffic demand every year and to solve many traffic problems. Especially, Advanced Traveller Information System(ATIS) is a transportation system to optimize the trip of each other vehicle. It is important to provide the driver with quick and comfortable path from source to destination. However, it is difficult to provide a shortest path in a road network with dynamic cost. Because the existing research has a static cost. Therefore, in this paper we propose an operator for searching traffic dependent shortest path. The proposed operator finds the shortest path from source to destination using a current time cost and a difference cost of past time cost. Such a method can be applied to the road status with time. Also, we can expect a predicted arrival time as well as the shortest path from source to destination. It can be applied to efficiently application service as ITS and have the advantages of using the road efficiently, reducing the distribution cost, preparing an emergency quickly, reducing the trip time, and reducing an environmental pollution owing to the saving the fuel.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.247-248
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• 2006

Carbon nitride films were evaluated that they had many advantages for miniature micro-humidity-sensors using the standard CMOS technology humidity sensing properties and CV characteristics of the carbon nitride films have been investigated for fabricating one chip HUSFET(Humidity Sensitive Field Effect Transistor) humidity sensors Carbon nitride films were deposited on silicon substrate with meshed electrodes by reactive RF magnetron sputtering system. The capacitor-type humidity sensor revealed good humidity-impedance characteristics with a wide range of relative humidity changes, decreasing $254k{\Omega}$ to $16k{\Omega}$ according to increase of relative humidity between 5% ~ 95% and the films were very stable on the Si wafer. These results reveal that $CN_x$ thin films can be used for Si based or HUSFET structure one chip micro-humidity sensors.

• Proceedings of the KSRS Conference
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• v.1
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• pp.204-207
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• 2006

COMS will receive two different meteorological signals in S-Band from IDACS (Image Data Acquisition and Control System) in ground station before transmitting them in L-Band to user station. MODCS (Meteorological Ocean Data Communication Subsystem) in satellite released the value of required PFD (Power Flux Density) to receive two signals. Thus, DATS (Data Acquisition and Transmission Subsystem) needs to send two signals to satellite with a satisfied EIRP. The value of minimum HPA (High Power Amplifier) output power was estimated by subtracting antenna directional gain and path loss between antenna and HPA from the needed EIRP in this paper. Besides the minimum output power of HPA, the maximum output power was also calculated with considering IMD (Inter-Modulation Distortion) characteristics. IMD is always occurred in the output of HPA when LRIT and HRIT are amplified by using single HPA as COMS application. In this paper, the setting of maximum output power was determined when the IMD of modelled HPA was corresponded to the requirement of MODCS.