• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1421-1423
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• 2003

Ultra Wideband is a new technology from commercial or civilian application viewpoint. It uses already allocated radio spectrum without causing significant interference to other users. It uses very low power, which is below the thermal noise of the receiver and is inherently difficult to detect by un-intentional users. Since, FCC approved the regulation for the commercial use of UWB in February 2002, the development of UWB technology is drastically gaining momentum. However, the technology itself is not new. It has already been used in military applications. UWB has three basic areas of applications, which are communication, positioning and imaging (UWB Microwave). The main commercial application will be for communication since it has very high data transfer rate for short distance. It can also be used for both indoor and outdoor 3-D positioning. Another important application is imaging like microwave remote sensing. An UWB sensor can pass through doors and walls and hence detect the objects inside the room. In this paper, we will introduce about UWB technology along with it’s various possible applications. We will also present some models to generate UWB signal and it’s analysis using signal-processing tools.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.429-431
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• 2003

CCTV network has been implemented to transmit the image information of platform, ticket gate and transfer section to local headquarters in the KNR(Korean National Railroad). But, communication system for transferring image information around accident field or wayside has not been established ret. thus, at Present implementation of communication equipment is necessary for dynamic image of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installation of optical cable in connection with the implemental plan for high-speed network from now on. And, the capacity of communication channel will be guaranteed much more than now between station and station. station and central headquarters when optical cable is completed. This study analyzes the image equipment of field for transmission and estimated matters to transmit image information of accident field to headquarters with using communication infrastructure. And, the study considers implemental method of communication network for long-distance image transmission from dozens to hundreds kilometers.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.1
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• pp.51-57
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• 2020

The fighter pilot uses radar mounted on the fighter to obtain high-resolution SAR (Synthetic Aperture Radar) images for a specific area of distance, and then the pilot visually classifies targets within the image. However, the target configuration captured in the SAR image is relatively small in size, and distortion of that type occurs depending on the depression angle, making it difficult for pilot to classify the type of target. Also, being present with various types of clutters, there should be errors in target classification and pilots should be even worse if tasks such as navigation and situational awareness are carried out simultaneously. In this paper, the concept of operation and functional structure of radar system for fighter jets were presented to transfer the SAR image target classification task of fighter pilots to radar system, and the method of target classification with high accuracy was studied using the CNN ensemble model to archive higher classification accuracy than single CNN model.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.88-91
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• 2015

Wireless power transmission (WPT) is a technology using free space as a conductor for transmitting electric power, which aims to transfer not just the transmission signal but also the electrical energy itself. This paper takes issue with the microwave wireless transmission technology utilizing in long-distance transmission. To construct the WPT system, several components are needed, such as RF Oscillator which converts AC power to RF through DC status, high gain antenna and RF rectifier that converts RF back to DC. The array topology is good a candidate for wide use. The objective of this research is to study the efect of the WPT systmem on electric power system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.409-416
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• 2007

In cellular orthogonal frequency division multiplexing (OFDM) networks, co-channel interference (CCI) leads to severe degradation in the BER performance. To solve this problem, maximum-likelihood estimation (MLE) CCI cancellation scheme has been proposed in the literature. MLE CCI cancellation scheme generates weighted replicas of the transmitted signals where weights represent the estimated channel transfer functions. The replica with the smallest Euclidean distance from the received signal is selected and data are detected. When the received power of the desired and interference signals are nearly the same, the BER performance is degraded. In this paper, we propose a closed-loop power control (PC) scheme capable of detecting the equal received power situation at the mobile station (MS) receiver by using the newly introduced parameter power ratio (PR). When this situation is detected, the MS sends a feedback to the desired base station (BS) which boosts the transmission power in the next frame. At cell edge where signal to interferer ratio (SIR) is considered to have average value between -5 dB and 10 dB, computer simulations show that the proposed CCI cancellation scheme has a gain of 7 dB at 28 Km/h.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.243-245
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• 2006

In this paper, the master system of Wide Area Monitoring System in order to prevent reaching a fault influence toward power system is proposed. This system has three real time algorithms and a on-line one using i-piu transfer data and provides operators with various understandable monitoring viewers in HMI based on raw data and algorithm results.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3261-3266
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• 2011

The interaction of bilobalide (BB) and ginkgolides B (GB) with bovine serum albumin (BSA) was investigated by fluorescent technique and UV/vis absorption spectroscopy. The results showed that BB and GB could intensively quench the fluorescence of BSA through a static quenching procedure. The binding constants (Ka) and the average binding distance between the donor (BSA) and the acceptor (ginkgolides) were obtained ($r_{BB}$ = 5.33 nm and $r_{GB}$ = 4.20 nm) by the theory of non-radiation energy transfer, and then the thermodynamic parameters such as ${\Delta}S^0$ (0.17-0.32 kJ/mol), ${\Delta}G^0$ (-20.76 ~ -17.79 kJ/mol) and ${\Delta}H^0$ (32.47-76.52 kJ/mol) could be calculated, respectively. All these results revealed that the interaction of BB and GB with BSA were driven mainly by hydrophobie force. The synchronous fluorescence spectroscopy was applied to examine the effect of two ginkgolides on the configuration of BSA. The configuration alteration of BSA could be induced by the hydrophobicitv environment of tyrosine with the increase of the drug concentration.

• Journal of architectural history
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• v.19 no.1
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• pp.71-90
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• 2010

This research has set up the fire protection and early suppression plan for Asan Oeam folk village which is composed of traditional wooden building instinct or complex. The results of this study are as follows. 1. The traditional wooden buildings require attentive considerations about the fire property of the Waga and the straw roofed house. Especially, as the straw roofed house has property that the transfer and development of the fire is fast. Therefore we studied on the transferring possibilities of the fire dangerous instinct through measuring the distance from of the eaves edge and trees in neighboring house. 2. This research proposes the tools for the priority protective building through consideration of fire risk and cultural priority because the fire prevention for all is impossible at the same time. 3. The most important thing is preserve the cultural identities of traditional folk village in establishing the fire hydrant and fire prevention facilities. Traditional folk village landscape should be considered.

• ETRI Journal
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• v.21 no.4
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• pp.23-28
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• 1999

In this paper, we analyze the performance benefits of broadband ATM networks when the call control and management flows are separated from user data flows. The virtual path tunneling concept for control and management flows are applied to the same physical ATM networks. The behaviors of channel throughput and transfer delay are analyzed. It results that the proposed virtual short-cut paths can maintain the network being stable with acceptable bandwidth. They are very useful to provide the stable control and management capabilities for Internet and mobile applications in the broadband ATM networks. In our numerical results, the effective throughputs of the proposed virtual shout-ut channel are about three times than those of end-to-end user data channels with hop distances of 10, and about two times than those with hop distance of 5 when the link blocking probability increases to 0.1. It concludes that the effective channel bandwidth are greatly reduced down while physical links are not stable and user traffic flows are occasionally overflowed.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.83.1-83.1
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• 2012

We have developed an self-consistent PDR model to synthesize warm CO lines of Herschel/PACS observations more accurately. The PDR model solves the FUV continuum radiative transfer, gas energetics, and chemistry simultaneously. A local FUV radiation flux is calculated by using a Monte Carlo method taking anisotropic scattering into account. A new (r, ${\delta}$) coordinate system was used, where the r is the distance from the origin and the ${\delta}$ is z/$R^2$ in the cylindrical coordinate of (R,z). This is an adequate coordinate system to represent a power-law density of an envelope and a high spatial resolution near the outflow wall. The gas enegetics and chemistry are solved locally and considered $10^4K$ blackbody radiation field instead of the interstellar radiation filed. This newly developed model can be used to analyze quantitatively the effect of UV-heated outflow walls on the warm molecular lines in the embedded proto-stellar objects.