• 대한전자공학회논문지SP
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• 제42권3호
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• pp.129-136
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• 2005

잡음이 중첩된 음성으로부터 잡음을 제거하기 위해서는, 잡음의 크기에 따라서 음성처리 시스템의 매개변수를 변경하는 것이 양호한 음질의 음성을 재생하는데 바람직하다. 본 논문은 백색잡음 및 자동차의 주행잡음에 의해 저하된 3단계의 음성을 학습할 수 있는 3층 구조의 신경회로망을 사용하여, 음성 중의 잡음량의 크기를 추정하는 방식을 제안한다. 실험결과, 제안한 방법은 신경회로망에 의해서 잡음량이 추정될 수 있는 것을 알 수 있었으며, 화자와 음성 데이터가 학습데이터와 다르더라도 백색잡음에 대해서 평균 $95\%$ 이상의 높은 잡음 추정율을 구할 수 있었다.

• 대한기계학회논문집A
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• 제25권3호
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• pp.353-361
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• 2001

Recently the boundary element method has been developed swiftly. The boundary element method is an efficient and accurate means for analysis of two dimensional elastic crack problems. This paper is concerned with the evaluation and the prediction of the stress intensity factor(SIF) for the crack emanating from the circular hole using boundary element method-neural network. The SIF of the crack emanating from the hole was calculated by using boundary element method. Neural network is used to evaluate and to predict SIF from the results of boundary element method. The organized neural network system (structure of four processing element) was learned with the accuracy 99%. The learned neural network system could be evaluated and predicted with the accuracy of 83.3% and 71.4% (in cases of SIF and virtual SIF). Thus the proposed boundary element method-neural network is very useful to estimate the SIF.

• 한국측량학회지
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• 제29권4호
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• pp.429-438
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• 2011

LiDAR technology is a combination of laser ranging, satellite positioning technology and digital image technology for study and determination with high accuracy of the true earth surface features in 3 D. Laser scanning data is typically a points cloud on the ground, including coordinates, altitude and intensity of laser from the object on the ground to the sensor (Wehr & Lohr, 1999). Data from laser scanning can produce products such as digital elevation model (DEM), digital surface model (DSM) and the intensity data. In Vietnam, the LiDAR technology has been applied since 2005. However, the application of LiDAR in Vietnam is mostly for topological mapping and DEM establishment using point cloud 3D coordinate. In this study, another application of LiDAR data are present. The study use the intensity image combine with some other data sets (elevation data, Panchromatic image, RGB image) in Bacgiang City to perform land cover classification using neural network method. The results show that it is possible to obtain land cover classes from LiDAR data. However, the highest accurate classification can be obtained using LiDAR data with other data set and the neural network classification is more appropriate approach to conventional method such as maximum likelyhood classification.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.723-726
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• 2012

A current intensity convertible CLD chip was fabricated using small and large FET cell configuration. Pinch-off current of 8.82 mA and 11.56 mA were obtained for small and large cell in the CLD chip, respectively. Constant current was fairly maintained until the breakdown voltage of 60 V. Measured knee voltage, $V_k$ were 3.8 V and 4.5 V for small and large cell, respectively. We configured current amplifying chip with parallel connection of each cells, by connecting 8 individual large cells in parallel network, 92.0 mA of current was obtained. The pinch-off constant current of CLD chip was varied very linearly with respect to the number of parallel connected cell.

• 디지털융복합연구
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• 제6권4호
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• pp.137-145
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• 2008

Embedded industry has emerged as one of the important industry for u-IT based application service. Technology development related to embedded hardware and software provides the base for the development of U-IT convergence industry. This study intends to suggest a research model to investigate the influence of industry, organization, technology factors on technology performance in the embedded companies. This study adopted research variables such as global network, local network, industry intensity, and technology capability as independent variables, with technology performance as a dependent variable from the existing literatures. The purpose of this study is to analyze the influence of industrial and organizational factors on technology performance of embedded companies SCM systems, including the moderating effect of government support. 94 companies data were collected by survey. The result of this empirical study is summarized as follows. First, local network and technology capability are the important determinants to influence technology performance of embedded companies in direct effect model. Second, global network and industry intensity has more positive influence on technology performance of embedded companies through a moderating variable of government support.

• 경영과정보연구
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• 제38권1호
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• pp.1-21
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• 2019

본 연구는 최고경영자와 이사회의 네트워크밀도와 R&D투자 간의 관계와 이들 관계에 영향을 미칠 수 있는 기업분할의 유형과 제도의 영향을 분석하는데 주된 목적을 두고 실행되었다. 연구목적의 달성을 위해 외환위기가 발생하고 기업분할 관련법(상법 530조)이 제정된 직후인 1999년부터 가장 최근의 자료수집이 가능한 2016년까지 총 18년의 연구기간 동안 기업분할을 실행한 국내기업들을 대상으로 다중회귀분석을 실행하였다, 분석결과는 국내기업 최고경영자와 이사회의 네트워크밀도와 R&D투자 간에 유의한 정(+)의 관계가 있음을 보여주고 있다. 또한 기업분할 유형과 관련하여 최고경영자와 이사회의 네트워크밀도와 R&D투자 간의 정의 관계는 비관련분할에서 보다 관련분할을 실행한 기업에서 강화되었음을 보여주고 있으며, 기업분할 제도와 관련해서는 물적분할보다 인적분할을 실행한 기업들에서 이들 관계가 강화되었음을 보여주고 있다. 신속한 의사결정이 요구되는 사안임에도 불구하고 장기적인 관점에서 높은 수준의 불확실성과 위험을 수반하게 되는 R&D투자결정에 있어 최고경영자와 이사회 간의 네트워크밀도가 긍정적인 영향을 미칠 수 있음을 보여주는 본 연구의 분석결과는 최고경영진들 간의 신뢰의 중요성을 강조해 온 네트워크이론의 주장과 일치한다. 또한 혁신역량 강화를 위한 R&D투자결정에 있어 개인수준의 요인들뿐만 아니라 조직수준의 요인이 함께 고려되어야 함을 시사하고 있다. 본 연구는 향후 기업분할의 활용을 통한 보다 전략적인 국내기업 지배구조의 개선방안에 대한 연구를 강화하는 동기를 제공해 줄 수 있을 것으로 기대된다.

• Communications for Statistical Applications and Methods
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• 제30권1호
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• pp.95-107
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• 2023

Purpose: The statistical analysis of point processes on linear networks is a recent area of research that studies processes of events happening randomly in space (or space-time) but with locations limited to reside on a linear network. For example, traffic accidents happen at random places that are limited to lying on a network of streets. This paper applies techniques developed for point processes on linear networks and the tools available in the R-package spatstat to estimate the intensity of traffic accidents in Leon County, Florida. Methods: The intensity of accidents on the linear network of streets is estimated using log-linear Poisson models which incorporate cubic basis spline (B-spline) terms which are functions of the x and y coordinates. The splines used equally-spaced knots. Ten different models are fit to the data using a variety of covariates. The models are compared with each other using an analysis of deviance for nested models. Results: We found all covariates contributed significantly to the model. AIC and BIC were used to select 9 as the number of knots. Additionally, covariates have different effects such as increasing the speed limit would decrease traffic accident intensity by 0.9794 but increasing the number of lanes would result in an increase in the intensity of traffic accidents by 1.086. Conclusion: Our analysis shows that if other conditions are held fixed, the number of accidents actually decreases on roads with higher speed limits. The software we currently use allows our models to contain only spatial covariates and does not permit the use of temporal or space-time covariates. We would like to extend our models to include such covariates which would allow us to include weather conditions or the presence of special events (football games or concerts) as covariates.

• Wind and Structures
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• 제15권1호
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• pp.43-64
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• 2012

Many potential small wind turbine locations are near obstacles such as buildings and shelterbelts, which can have a significant, detrimental effect on the local wind climate. A neural network-based model has been developed which predicts mean wind speed and turbulence intensity at points in an obstacle's region of influence, relative to unsheltered conditions. The neural network was trained using measurements collected in the wakes of 18 scale building models exposed to a simulated rural atmospheric boundary layer in a wind tunnel. The model obstacles covered a range of heights, widths, depths, and roof pitches typical of rural buildings. A field experiment was conducted using three unique full scale obstacles to validate model predictions and wind tunnel measurements. The accuracy of the neural network model varies with the quantity predicted and position in the obstacle wake. In general, predictions of mean velocity deficit in the far wake region are most accurate. The overall estimated mean uncertainties associated with model predictions of normalized mean wind speed and turbulence intensity are 4.9% and 12.8%, respectively.

• 지식경영연구
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• 제19권3호
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• pp.189-223
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• 2018

This paper examined the effect of innovation networks comprising research and development (R&D) collaboration on innovation performance of Korean pharmaceutical firms. As co-assigned patents and co-affiliated publications are common technical outcomes of successful R&D collaboration in the pharmaceutical industry, social network analysis technique was applied for analyzing innovation networks through patent and publication data. Results of Social network analysis indicated that a small set of highly innovative firms in the Korean pharmaceutical industry were actively involved in patenting and publishing. And the analysis of structural equation model found the followings: (1) R&D intensity significantly affected patenting, publication and new drug development, (2) the activity of patenting and publishing was positively related with the innovation performance measured by new drug development, and (3) R&D collaboration in terms of degree centrality of co-patent network played significant moderating roles on the relationships among R&D intensity, patenting, and new drug development. These findings are expected to be helpful to researchers as well as policy-makers to devise innovation-promoting policies in the Korean pharmaceutical industry. Discussions and limitations of the study are provided in the last part.

• 대한전자공학회논문지SD
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• 제49권5호
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• pp.22-29
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• 2012

본 논문은 symmetric balance incomplete block design(BIBD) code와 arrayed-waveguide grating(AWG) router의 주기적인 특성을 이용하여 optical CDMA network을 위한 coder-decoder(codec)을 구성하였다. 기존의 M-sequence code를 이용한 경우보다 다양한 구성을 할 수 있고 이 시스템의 잡음인 phase-induced intensity noise(PIIN)와 thermal noise를 분석하여 BER을 계산한 결과 향상된 성능을 보임을 알 수 있었다.