• Title/Summary/Keyword: regularized

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A Near Optimal Linear Preceding for Multiuser MIMO Throughput Maximization (다중 안테나 다중 사용자 환경에서 최대 전송율에 근접하는 선형 precoding 기법)

  • Jang, Seung-Hun;Yang, Jang-Hoon;Jang, Kyu-Hwan;Kim, Dong-Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.4C
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    • pp.414-423
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    • 2009
  • This paper considers a linear precoding scheme that achieves near optimal sum rate. While the minimum mean square error (MMSE) precoding provides the better MSE performance at all signal-to-noise ratio (SNR) than the zero forcing (ZF) precoding, its sum rate shows superior performance to ZF precoding at low SNR but inferior performance to ZF precoding at high SNR, From this observation, we first propose a near optimal linear precoding scheme in terms of sum rate. The resulting precoding scheme regularizes ZF precoding to maximize the sum rate, resulting in better sum rate performance than both ZF precoding and MMSE precoding at all SNR ranges. To find regularization parameters, we propose a simple algorithm such that locally maximal sum rate is achieved. As a low complexity alternative, we also propose a simple power re-allocation scheme in the conventional regularized channel inversion scheme. Finally, the proposed scheme is tested under the presence of channel estimation error. By simulation, we show that the proposed scheme can maintain the performance gain in the presence of channel estimation error and is robust to the channel estimation error.

Taebaek Mountainous Region as a Natural Unit (자연 지역으로서의 태백 산지)

  • Kee, Keun-Doh
    • Journal of the Korean association of regional geographers
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    • v.8 no.4
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    • pp.468-479
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    • 2002
  • This study attempts to characterize Taebaek mountainous region as a natural unit, relating to morphoclimatic milieu and landform development patterns of the mountains of each lithologic type. In the case of granitic mountains of Nothern parts of this region, the slopes presents more or less steep or irregular profile because of abundant microforms of exposed bedrocks and blocks. The development of such landscape is essentially due to differential weathering, associated with difference of joint density. In the case of gneissic mountains, the slopes are well regularized straight steep ones, due not only to generalized superficial weathering but also to massmovement of weathered materials. In the Middle parts of this region, especially in Taegwallyong area, with frequent alternations both of freezing-thawing and of snow accumulation-melting, the roles played by cryo-nival processes proved to be important in weathering of granite as well as in morpho-pedogenesis. In this area, weathered mantle, developed by cryogenic activity under humid condition of nival environment, covered almost all over the slopes. Although Southern parts of this region consist of limestone, on the mountainous volume, distribution of Karst forms are limited while predominate none karst forms such as cockpit type peaks, V-shaped type valleys dissecting steep slopes covered with thin deposits in thickness containing rock debris.

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Simplification of Boundary Representation Models Based on Stepwise Volume Decomposition (단계적 볼륨분해에 기반한 경계표현 모델의 단순화)

  • Kim, Byung Chul;Mun, Duhwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.10
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    • pp.1305-1313
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    • 2013
  • In this study, a method to apply feature-based simplification to boundary representation models is proposed. For feature-based simplification, a volume decomposition tree is created from a boundary representation model. The volume decomposition tree is represented by regularized Boolean operations of additive volumes, subtractive volumes, and fillet/round/chamfer volumes, and it is generated by stepwise volume decomposition, which consists of fillet/round/chamfer decomposition, wrap-around decomposition, volume split decomposition, and cell-based decomposition. After the volume decomposition tree is transformed to an infix expression, the CAD model can be simplified by reordering the volumes. To verify the proposed method, a prototype system was implemented, and experiments on test cases were conducted. From the results of the experiments, it is verified that the proposed method is useful for simplifying CAD models based on boundary representation.

Geometric Regualrization of Irregular Building Polygons: A Comparative Study

  • Sohn, Gun-Ho;Jwa, Yoon-Seok;Tao, Vincent;Cho, Woo-Sug
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.6_1
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    • pp.545-555
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    • 2007
  • 3D buildings are the most prominent feature comprising urban scene. A few of mega-cities in the globe are virtually reconstructed in photo-realistic 3D models, which becomes accessible by the public through the state-of-the-art online mapping services. A lot of research efforts have been made to develop automatic reconstruction technique of large-scale 3D building models from remotely sensed data. However, existing methods still produce irregular building polygons due to errors induced partly by uncalibrated sensor system, scene complexity and partly inappropriate sensor resolution to observed object scales. Thus, a geometric regularization technique is urgently required to rectify such irregular building polygons that are quickly captured from low sensory data. This paper aims to develop a new method for regularizing noise building outlines extracted from airborne LiDAR data, and to evaluate its performance in comparison with existing methods. These include Douglas-Peucker's polyline simplication, total least-squared adjustment, model hypothesis-verification, and rule-based rectification. Based on Minimum Description Length (MDL) principal, a new objective function, Geometric Minimum Description Length (GMDL), to regularize geometric noises is introduced to enhance the repetition of identical line directionality, regular angle transition and to minimize the number of vertices used. After generating hypothetical regularized models, a global optimum of the geometric regularity is achieved by verifying the entire solution space. A comparative evaluation of the proposed geometric regulator is conducted using both simulated and real building vectors with various levels of noise. The results show that the GMDL outperforms the selected existing algorithms at the most of noise levels.

A Strategy of Information Management System for Construction Company (건설산업의 효율적 정보관리체계 구축전략)

  • Lee Tai Sik;Kim Yong Chan
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.458-461
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    • 2001
  • The whole of industry sectors are getting achieved BPR(Business process Reencountering) which innovate the inefficient product organization through examined the value chain. Besides, they try to integrate ERP, CRM, and SCM which is based on value chain. Construction Industry, however, not only is not regularized it but is not inadequacy about information mind. Nowadays Korean government lead the construction CALS, only some large company Innovate and restructure the organization and product structure. It Is necessary to efficient manage the project information and historical data and develop CIC/PMIS to transfer from the function based information-flow to the project based information-flow. The purpose of the Information management system's success In Korea, therefore, this paper analyzes the information-intensive problems and proves the device to achieve the Information Management System through the Standardization, Synchronization, Centralization for Construction Company.

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A Study on the Convergence Relativity of the Combining Curved Forms of Tall Buildings (초고층빌딩의 비정형 곡면형태 조합 및 복합관계에 관한 연구)

  • Park, Sang-Jun
    • The Journal of the Korea Contents Association
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    • v.20 no.3
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    • pp.190-199
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    • 2020
  • Globally, more super-tall buildings tend to be constructed competitively in the social and economic foundations. In the circumstance, this study is aimed at establishing a paradigm of super-tall buildings in terms of their various forms. Symbolizing a city or state, super-tall buildings not only are used as resources of tourism, but play an important role as a characteristic landmark. Therefore, it is necessary to find a curved form for a futuristic perspective. The purpose of this study is to infer the convergence relativity of curved forms among complex and diverse unstructured construction forms. This study used as subjects 50 super-tall buildings among the ranking data selected Council on Tall Buildings and Urban Habitat (CTBUH) in order for the basis of constructability related to actual design, rather than the way of recognizing a formative type, in the classification of curved forms into regularized surfaces, developable surfaces, and double-curved surfaces. The results of this study are presented as follows. This classification can be used as a fundamental material which is reasonably involved in the design process pursuing diverse curved surfaces in terms of design of tall buildings.

DOA Estimation of Multiple Signal and Adaptive Beam-forming for Mobile Communication Environments (이동통신 환경에서 다중신호의 DOA 추정과 적응 빔성형)

  • Yang, Doo-Yeong;Lee, Min-Soo
    • The Journal of the Korea Contents Association
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    • v.10 no.12
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    • pp.34-42
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    • 2010
  • The DOA(direction of arrival), which is based on parametric and nonparametric estimation algorithm, and adaptive beamforming algorithm for mobile communication environments are researched and analyzed. In parametric estimation algorithm, eigenvalues of the signal component and the noise component are obtained from correlation matrix of received signal by array antenna and power spectrum of the received signal is discriminated from them. Otherwise, in nonparametric estimation algorithm, we minimize a regularized objective function for finding a estimate of the signal energy as a function of angle, using nonquadratic norm which leads to supper resolution and noise suppression. And then, DOA is estimated by the signal and noise spatial steering vector, and adaptive beam-forming pattern is improved by weight vectors obtained from the spatial vector. Therefore, the improved directional estimation algorithm with regularizing sparsity constraints offers super-resolution and noise suppression compared to other algorithms.

Effective Cooperative FFT based pilot Sensing Scheme for Detecting DTV Signals in Cognitive Radio (인지무선 시스템에서 DTV 신호 검출을 위한 FFT 기반의 협력 파일럿 센싱)

  • Lee, So-Young;Kim, Eun-Cheol;Kim, Jin-Young
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.1
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    • pp.27-33
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    • 2010
  • Cognitive radio (CR), which is proposed as a technology that utilizes the frequency resources effectively, has been studied to relive scarcity of the frequency resources. Also, FCC revises the regulation to reuse the TV white spaces for applying CR system and allows to use the TV white spaces by CR devices and use of CR device may be regularized after conversion by DTV in 2009. In order to reuse the TV bands without harmful interference to primary user, correct spectrum sensing should be needed to detect DTV signals that is the primary user in TV bands. In this paper, we detect the DTV signal using FFT-based pilot sensing and cooperative sensing scheme is applied for the reliability of the sensing performance and the accuracy of the detection probability. Also, in order to make the reliable decision, the majority rule is proposed.

Ratio Estimation of Indirect Cost Sector about Defense Companies by Statistic Technique (통계 기법에 의한 방산업체의 간접원가부문 비율 추정)

  • Lim, Hyeoncheol;Kim, Suhwan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.4
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    • pp.246-252
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    • 2017
  • In the defense acquisition, a company's goal is to maximize profits, and the government's goal is to allocate budgets efficiently. Each year, the government estimates the ratio of indirect cost sector to defense companies, and estimates the ratio to be applied when calculating cost of the defense articles next year. The defense industry environment is changing rapidly, due to the increasing trend of defense acquisition budgets, the advancement of weapon systems, the effects of the 4th industrial revolution, and so on. As a result, the cost structure of defense companies is being diversifying. The purpose of this study is to find an alternative that can enhance the rationality of the current methodology for estimating the ratio of indirect cost sector of defense companies. To do this, we conducted data analysis using the R language on the cost data of defense companies over the past six years in the Defense Integrated Cost System. First, cluster analysis was conducted on the cost characteristics of defense companies. Then, we conducted a regression analysis of the relationship between direct and indirect costs for each cluster to see how much it reflects the cost structure of defense companies in direct labor cost-based indirect cost rate estimates. Lastly a new ratio prediction model based on regularized regression analysis was developed, applied to each cluster, and analyzed to compare performance with existing prediction models. According to the results of the study, it is necessary to estimate the indirect cost ratio based on the cost character group of defense companies, and the direct labor cost based indirect cost ratio estimation partially reflects the cost structure of defense companies. In addition, the current indirect cost ratio prediction method has a larger error than the new model.

Gait-based Human Identification System using Eigenfeature Regularization and Extraction (고유특징 정규화 및 추출 기법을 이용한 걸음걸이 바이오 정보 기반 사용자 인식 시스템)

  • Lee, Byung-Yun;Hong, Sung-Jun;Lee, Hee-Sung;Kim, Eun-Tai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.1
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    • pp.6-11
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    • 2011
  • In this paper, we propose a gait-based human identification system using eigenfeature regularization and extraction (ERE). First, a gait feature for human identification which is called gait energy image (GEI) is generated from walking sequences acquired from a camera sensor. In training phase, regularized transformation matrix is obtained by applying ERE to the gallery GEI dataset, and the gallery GEI dataset is projected onto the eigenspace to obtain galley features. In testing phase, the probe GEI dataset is projected onto the eigenspace created in training phase and determine the identity by using a nearest neighbor classifier. Experiments are carried out on the CASIA gait dataset A to evaluate the performance of the proposed system. Experimental results show that the proposed system is better than previous works in terms of correct classification rate.