• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.645-652
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• 2010

The performance of the payload Electro-Optical System (EOS) in satellite system is affected by various factors, such as optics design, camera electronics design, and the characteristics of the CCD (Charge Coupled Device) used, etc. Of these factors, the camera electronics design is somewhat unique in that its operational parameters can be adjusted even after the satellite launch. In this paper, the effect of video gain on the non-uniformity correction performance is addressed. And a new optimal non-uniformity correction scheme is proposed and analyzed using the data from real camera electronics unit based on a TDI (Time Delayed Integration) type of CCD. The test results show that the performance of the conventional non-uniformity correction scheme is affected significantly when the video gain is added. On the other hand, in our proposed scheme, the performance is not dependent on the video gain. The insensitivity of the non-uniformity performance on the video-gain is mainly due to the fact that the correction is performed after the dark signal is subtracted from system response.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.507-510
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• 2014

The initial process configuration of biometric information system is performed by the same sequences statically and consistently without changing after the system is running. However, this static process configuration appears an inefficient performance to the applications of the mobile biometric information system in the mobile computing environment. This work proposes the dynamic process design and execution method as a way to overcome these inefficient processes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1619-1625
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• 2018

Portable electronic devices secondary batteries can cause fire and explosion due to micro-current change in addition to the situation of short-circuit inrush current, safety can not be secured with a general operation limited current fuse. Therefore, in secondary battery, it is necessary for the protector to satisfy both the limit current type operation in the open-short-circuit inrush current and the current detection operation characteristic in the micro current change situation and for this operation, a fuse for the current detection type secondary battery protection circuit can be applied. The purpose of this study is to design a protection device that operates stably in the hazardous situation of small capacity secondary battery for portable electronic devices through the design of low melting fuse elements alloy of sensing type fuse and secures stability in abnormal current state. As a result of the experiment, I-T and V-T operation characteristics are satisfied in a the design of the alloy of the current sensing type self-contained low melting point fuse and the resistance of the heating resistor. It is confirmed that it can prevent accidents of short circuit over-current and micro current change of secondary battery.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.132-139
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• 2005

Wireless bio-signal sensing system, which is based on the principle of Doppler radar, can measure a respiration and heart rates with a periodic movement of skin and muscle near the heart. Though the sensing monostatic system using a circulator has been studied, this bistatic system can be improved by using a circular polarized antenna which has a high isolation between transmitter and receiver. In this paper, we measured the bio-signal without the direct contact with the person. The design of each system and experimental results are discussed.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.451-459
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• 2016

The damages on the crops by the wild animals such as wild boars and water deer are serious in rural areas these days. In this paper, a low-cost and adaptive system based on open source for sensing and repelling farm pest animals is proposed. The system contains the server which is Arduino Due connected with the wireless communication modules such as RF, Zigbee, and WiFi module, speaker, and so on. It also has the sensing modules and LED blinkers which communicates with the server by wireless modules. Once a detecting signal is transmitted to the server. The server is waked up from sleep mode and the repelling subsystems such as loud speaker and LED blinker(s) are activated to scare the unwanted animal away. The total system is managed by Android smartphone easily.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.704-712
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• 2010

Recently, the lack of the frequency have been emerged due to the use of various wireless terminals. To find solutions for obtaining new frequency resources and for avoiding an interference, a cognitive radio technology have focused on as the new technology that can use the whitespace in TV broadcasting band. In this paper, the Cognitive Radio terminal system for whitespace in TV band is first introduced. The purpose of the CR terminal platform is to evaluate the feasibility of the unlicensed wireless service in the TV band. Then, we design and develop the software for Sensing MAC applied the cognitive radio terminal system. The developed Sensing MAC software based on IEEE 802.22 specification can be aware of using the whitespace in TV band that operates on cognitive radio terminal system. Finally, we have tested for evaluating the sensing MAC module.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1147-1167
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• 2015

Wireless smart sensors, which have become popular for monitoring applications, are an attractive option for implementing structural control systems, due to their onboard sensing, processing, and communication capabilities. However, wireless smart sensors pose inherent challenges for control, including delays from communication, acquisition hardware, and processing time. Previous research in wireless control, which focused on semi-active systems, has found that sampling rate along with time delays can significantly impact control performance. However, because semi-active systems are guaranteed stable, these issues are typically neglected in the control design. This work achieves active control with smart sensors in an experimental setting. Because active systems are not inherently stable, all the elements of the control loop must be addressed, including data acquisition hardware, processing performance, and control design at slow sampling rates. The sensing hardware is shown to have a significant impact on the control design and performance. Ultimately, the smart sensor active control system achieves comparable performance to the traditional tethered system.

• Current Optics and Photonics
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• v.7 no.5
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• pp.511-517
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• 2023

Pipelines play an important role in urban water supply and drainage, oil and gas transmission, etc. This paper presents a technique for pattern recognition of fiber optic vibration signals collected by a distributed vibration sensing (DVS) system using a deep learning residual network (ResNet). The optical fiber is laid on the pipeline, and the signal is collected by the DVS system and converted into a 64 × 64 single-channel grayscale image. The grayscale image is input into the ResNet to extract features, and finally the K-nearest-neighbors (KNN) algorithm is used to achieve the classification and recognition of pipeline damage.

• Korean Journal of Remote Sensing
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• v.2 no.1
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• pp.49-54
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• 1986

This study has been intended to design an optimum meteorological information system appropriate for Korea as a part of 5 year development plan. The 5 year plan was that to set up new direction in order to modernize meteorological data acquisition, processing and information distribution. The detailed research has been led to presentation of optimum meteorological information system of Korea eventually, selecting the computerization of communication as the primary object of modernization. In the study, research concerning effective equipment configuration, data communications internal as wall as external, and the related implementations has been carried out with the approach of system component consideration under system application design. As tile results of the study, integrated network of meterorological data communication was presented including earth quakes, radar, aerologic, marine weather observations and so on.

• Journal of Power Electronics
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• v.6 no.1
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• pp.18-28
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• 2006

The Electric Power Subsystem (EPS) is one of the most critical systems on any satellite because nearly every subsystem requires power. This makes the choice of power systems the most important task facing satellite designers. The main purpose of the Satellite EPS is to provide continuous, regulated and conditioned power to all the satellite subsystems. It has to withstand radiation, thermal cycling and vacuums in hostile space environments, as well as subsystem degradation over time. The EPS power characteristics are determined by both the parameters of the system itself and by the satellite orbit. After satellite separation from the launch vehicle (LV) to its orbit, in almost all situations, the satellite subsystems (attitude determination and control, communication and onboard computer and data handling (OBC&DH)), take their needed power from a storage battery (SB) and solar arrays (SA) besides the consumed power in the EPS management device. At this point (separation point, detumbling mode), the satellite's angular motion is high and the orientation of the solar arrays, with respect to the Sun, will change in a non-uniform way, so the amount of power generated by the solar arrays will be affected. The objective of this research is to select satellite EPS component types, to estimate solar array illumination parameters and to determine the efficiency of solar arrays during both detumbling and normal operation modes.