• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.73-81
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• 2005

We propose an automatic modulation recognition scheme which extracts pre-defined key features from the received signal and then applies equal gain combining method to determine the used modulation. Moreover, we compare and analyze the performance of the proposed algorithm with that of decision-theoretic algorithm. Our scheme extracts five pre-defined key features from each data segment, a data unit for the key feature extraction, which are then averaged over all the segments to recognize the modulation according to the decision procedure. We check the performance of the proposed algorithm through computer simulations for analog modulations such as AM, FM, SSB and for digital modulations such as FSK2, FSK4, PSK2, and PSK4, by measuring recognition success rate varying SNR and data collection time. The result shows that the performance of the proposed scheme is comparable to that of the decision-theoretic algorithm with less complexity.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.129-138
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• 1996

Localization of concrete is a phenomenon such that the deformation of concrete is localized in finite region with softening behavior and it governs ultimate load of concrete. In this Paper, concrete under strain localization was modeled with localization region and non-localization region and lc~calization behavior was formulated based on averaging concept of heterogeneous material. By using the formulation, the localization phenomena of concrete under uniaxial loadings were well predicted. The analytical results show that size of localization region of concrete under uniaxial compression is three times of maximum aggregate size and the size effect of concrete is well predicted. The use of tension-softening curve obtained from direct tension test is suitable for well prediction of localization of concrete under uniaxial tension.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7B
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• pp.628-637
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• 2003

This paper describes a novel multiplexing scheme for delay-sensitive multiple VBR-coded bit streams in live multimedia service offered to high-speed networks. The primary goal of multiplexing in this paper is to keep delay limits of each bit streams and to enhance network resource utilization when they no multiplexed and transmitted over network. For this aim, this paper presents a dynamical control scheme which does not cause violation of any delay constraints to each bit steam. The scheme is based on the assumption that recent behavior of the each bit scream has high correlation with near-term future behavior. Such property is used to make as flat as possible by both temporal averaging on a stream-by-stream and spatial averaging is introduced when multiple VBR-coded bit streams are multiplexed. The effectiveness of the scheme is evaluated by several simulation using an MPEG-coded video trace of Star_wars and it is shown that the proposed scheme can effectively reduce the feat rate md coefficient of variation of the multiplexed transmission rate.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.34-43
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• 2008

The state-space average model is extended to buck-boost, and buck-boost topology switching mode DC/DC converters and modified to have higher precision without increment of computation. The modified model is used in continuous conduction mode(CCM) switching DC/DC converters and some significant conclusions are derived. This paper discusses the discontinuous conduction mode(DCM) modeling of DC/DC converter and critical characteristic using average model of switch. Average model of switch approach is expended to the modeling of boundary conduction mode DC/DC converters that operate at the boundary between continuous conduction mode(CCM) and discontinuous conduction mode(DCM). Frequency responses predicted by the average model of switch are verified by simulation and experiment. A prototype featuring 15[V] input voltage, 24[V] output voltage, and 24[W] output power using MOSFET.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.879-879
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• 2012

강우현상의 공간적 변동성에 대한 해석은 수자원 계획 및 관리를 위해 중요한 관심사가 되고 있다. 일반적으로 우리가 얻을 수 있는 강우자료는 한 지점에 설치되어 있는 우량계에 의한 관측된 지점강우량자료이다. 기존의 집중형 수문모형이 유출과정의 공간적인 분포 및 변화를 유역단위로 평균화해서 취급하는 개념기반의 모형임에 반해서 분포형 수문모형은 유역을 수문학적으로 균일한 매개변수를 갖는 소유역 또는 격자망으로 구분하여 적용하는 것으로, 도시화 등 토지이용의 변화나 기타 유역내의 물리적인 특성의 변화가 수문과정에 미치는 영향을 잘 모의할 수 있다. 따라서 본 연구에서는 Vflo$^{TM}$ 분포형 강우-유출 모형과 IDW, Ordinary Kriging, Thiessen 등의 강우 분포 기법을 이용하여 낙동강 제 1지류인 금호강의 동촌 수위관측소 유역($1,544km^2$)을 출구로 하여 강우-유출모의를 하였다. 이를 위하여 강우-유출에 영향을 주는 매개변수를 선정하고 동촌 수위관측소의 실측 유량자료를 바탕으로 하여 IDW, Kriging, Thiessen 등의 면적강우량 산정방법별로 모형의 보정(2007, 2009) 및 검증(2010)을 실시하였다. 모의 된 유출량과 실측유량의 상관성은 결정계수 $R^2$에서 IDW 과 Kriging의 경우 0.95 ~ 0.99의 상관성을 나타냈으며 Thiessen 의 경우 0.94 ~ 0.99의 값을 나타냈다. Nash-Sutcliffe 모형효율은 IDW의 경우 0.95 ~ 0.98, Kriging의 경우 0.94 ~ 0.99를 나타냈으며 Thiessen의 경우는 0.90 ~ 0.98의 모형효율을 나타내었다. 이때 포화투수계수와 조도계수가 전체 유량과 첨두시간에 영향을 주었다. 호우사상을 선정하여 검보정을 실시 한 결과, 유역의 유출 모의를 수행하였을 때 선행강우량에 따라서 토양의 침투능에 영향을 많이 주고 있기 때문에, 선행 토양함수조건(Antecedent Moisture Condition: AMC)으로 분류한 뒤에 AMC 조건에 따라서 유출-모의를 수행하는 것이 타당하다고 판단된다.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.67-77
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• 2004

A treatment of outlier has been discussed. Outliers disrupt the reliability of information systems and they should be eliminated prior to the information and/or data fusion. A time series-based elimination algorithm were proposed and prediction interval, as a criterion of acceptable value width, was obtained with the model. Ten actual link values were used and the best model was identified as IMA(1,1). Although the actual verification was difficult in a sense that the matching process between the eliminated data and model data was not readily available, the proposed model can be successfully used in practice with some calibration efforts.

• Resources Recycling
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• v.21 no.2
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• pp.17-33
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• 2012

In order to review the recent technological progress and issues on the urban mine resources recycling in Japan and Korea, recycling process of the ELV(End of Life Vehicles) and E-waste(WEEE) were studied. Although technological level for processing of the ELV and E-waste is almost similar in both countries, the treatment of hazadous materials of ELV such as freon, air bag and ASR is unsufficient in Korea. In the E-waste recycling, the technological level is deeply different according to the enterprise size in Korea. Finally, the big R&D project on recycling of urban mine resources sponsored by government in both countries were discussed.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.4
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• pp.169-177
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• 2006

In this paper, we present an efficient image reconstruction method which is suited to remove various noise generated from measurement using X-ray attenuation. To be specific, we present a wavelet method to efficiently remove ring artifacts, which are caused by inevitable mechanical error in X-ray emitters and detectors. and streak artifacts, which are caused by general observation errors and Fourier transform-based reconstruction process. To remove ring artifacts related noise from projections, we suggest to estimate the noise intensity by using the fact that the noise related to ring artifacts has a strong correlation in the angle direction, and remove them by using wavelet shrinkage. We also suggest to use wavelet-vaguelette decomposition for general-purpose noise removal and image reconstruction. Through simulation studies. we show that the proposed method provides a better result in ring artifact removal and image reconstruction over the traditional Fourier transform-based methods.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.388-393
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• 2010

Cultural Content Technology(CT, Culture Technology) for the development of cultural industry and the commercialization of technology, cultural contents, media, mount, pass the value chain process and increase the added value of cultural products that are good for all forms of intangible technology. In the field of Culture Technology, Music by analyzing the characteristics of the development of a variety of applications has been studied. Associated with EEG measures and the results of their research in response to musical stimuli are used to detect and study is getting attention. In this paper, the musical stimuli in EEG signals by amplifying the corresponding reaction to the averaging method, ERP (Event-Related Potentials) experiments based on the process of extracting sound methods for removing noise from the ICA algorithm to extract the tone and noise removal according to the results are applied to analyze the characteristics of EEG.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.840-845
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• 2007

In a wireless sensor network, a middleware used to support efficient processing and fast delivering of sensing data should handle the data loss problem at an intermediate sensor node caused by unexpected sudden data burst. In his paper, it proposes a Delta-Average method for enhancing the efficiency of data aggregation and correctness where the sensed data should be delivered only with the limited computing power and energy resource. With the proposed method, unnecessary data transfer of the duplicate data is eliminated and data correctness is enhanced by using the proposed averaging and data differentiating scheme when an instantaneous data burst is occurred. Finally, with the TOSSTM simulation results on TinyDB, we verify that the correctness of the transferred data is enhanced.