• Title/Summary/Keyword: D2D systems

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Introducing and Surveying 4D Models in AEC Industry (4D 공정관리시스템의 개발현황 조사연구)

  • Kang Leen-Seok
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.137-142
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    • 2001
  • The traditional schedule management system provides project manager with analysis reports, such as progress control, earned value management and resource management, including schedule chart. However, the reports and functions in the traditional system are still limited in 2D concept. Recently, the scheduling method is using 4D concept that time of construction schedule is linked to space of drawings. This study presents the limitation of those systems and an improved method for developing 4D system through the comparative analysis of representative 4D systems that are developed up to date.

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Genotoxicity of the Herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D): Higher Plants as Monitoring Systems

  • Enan, Mohamed R.
    • Journal of Forest and Environmental Science
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    • v.25 no.3
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    • pp.147-155
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    • 2009
  • Higher plants provide valuable genetic assay systems for screening and monitoring environmental pollutants. They are now recognized as excellent indicators of mutagenic effects of environmental chemicals and are applicable for the detection of environmental mutagens both indoor and outdoor. 2,4-dichlorophenoxyacetic acid (2,4-D) is a herbicide commonly used in agriculture. The residues of 2,4-D are present in air, water, soil and edible plants. It constitutes a real hazard to the public health because it's wide spread use in agriculture. Genotoxic effects of 2,4-D on plant cells and potential of higher plants as a biomonitoring system for detecting chemical mutagens are evaluated. It is recommended that higher plant systems have been accepted by regulatory authorities as an alternative biomonitoring system for the detection of possible genetic damage resulting from pollution and the use of environmental chemicals.

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Feedback Control for Multidimensional Linear Systems and Interpolation Problems for Multivariable Holomorphic Functions

  • Malakorn, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1847-1852
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    • 2004
  • This article provides the connection between feedback stabilization and interpolation conditions for n-D linear systems (n > 1). In addition to internal stability, if one demands performance as a design goal, then there results an n-D matrix Nevanlinna-Pick interpolation problem. Application of recent work on Nevanlinna-Pick interpolation on the polydisk yields a solution of the problem for the 2-D case. The same analysis applies in the n-D case (n > 2), but leads to solutions which are contractive in a norm (the "Schur-Agler norm") somewhat stronger than the $H^{\infty}$ norm. This is an analogous version of the connection between the standard $H^{\infty}$ control problem and an interpolation problem of Nevanlinna-Pick type in the classical 1-D linear time-invariant systems.

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Distributed Fusion Moving Average Prediction for Linear Stochastic Systems

  • Song, Il Young;Song, Jin Mo;Jeong, Woong Ji;Gong, Myoung Sool
    • Journal of Sensor Science and Technology
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    • v.28 no.2
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    • pp.88-93
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    • 2019
  • This paper is concerned with distributed fusion moving average prediction for continuous-time linear stochastic systems with multiple sensors. A distributed fusion with the weighted sum structure is applied to the optimal local moving average predictors. The distributed fusion prediction algorithm represents the optimal linear fusion by weighting matrices under the minimum mean square criterion. The derivation of equations for error cross-covariances between the local predictors is the key of this paper. Example demonstrates effectiveness of the distributed fusion moving average predictor.

Current Status of the 3-D Spatial Information Systems for Local Government and Their Revitalization Plan (지자체 3차원 공간정보시스템의 현황 및 활성화 방향에 관한 연구)

  • Yun, Jeong-Mi;Kim, Tae-Woo;Suh, Yong-Cheol
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.4
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    • pp.22-32
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    • 2011
  • The 3-D spatial information systems are effective for systematical urban management and civil administration. They have more visibility than the 2-D spatial information systems with height information. However, the 3-D spatial information systems for local government were developed by central government's master plan of national spatial informatization. It means that the systems are biased toward the 3-D viewing as the visibility like a 3-D display and simulation, without reflected distinct characteristics of the local society. In order to utilize municipalities'3-D spatial information systems efficiently, above all, we have to understand the current status of municipalities'3-D spatial information systems and then have to search the ways applying actively. Therefore, we reviewed the current 3-D spatial information systems and discussed the development directions with central government's national spatial informatization master plans in order to perform properly on the 3-D spatial information system's excellent functions. We analyzed each system characteristics based on the applicability to civil administration which has the potential usage of spatial information. Additionally we suggested the development directions of 3-D spatial information systems for municipalities'through reviewing which civil administrative tasks 3-D spatial information can be applied. The consideration was based on the user demand research of the 3-D spatial information system in Chungcheongnam-do.

A Low-Complexity 2-D MMSE Channel Estimation for OFDM Systems (OFDM 시스템을 위한 낮은 복잡도를 갖는 2-D MMSE 채널 추정 기법)

  • Kim, Jung-In;Jang, Jun-Hee;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5C
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    • pp.317-325
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    • 2011
  • For OFDM (Orthogonal Frequency Division Multiplexing) systems, 2-D MMSE (2-Dimensional Minimum Mean Square Error) channel estimation provides optimal performance in frequency/time selective fading channel environment. However, the 2-D MMSE channel estimation has high computational complexity due to the large matrix size, because the 2-D MMSE channel estimation considers time as well as frequency axis for channel estimation. To reduce the computational complexity, we propose a modified 2-D MMSE channel estimator which is based on 1-D MMSE channel estimation with weighted sum. Furthermore, we consider RMS delay spread and Doppler frequency estimation for 2-D MMSE channel estimation. We show that the proposed method can significantly reduce computational complexity as well as that it can perform close to 2-D MMSE channel estimation.

A Study on 3D Training Material for Efficient Production of Electrical Systems in the Shipbuilding (선박건조 과정에서 효율적인 전장시스템 설치를 위한 3D 훈련자료에 관한 연구)

  • Lee, Jong-Min;Moon, Chae-rin;Heo, Sungphil;Kim, Jong-Seong
    • Journal of Korea Society of Industrial Information Systems
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    • v.25 no.4
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    • pp.1-8
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    • 2020
  • In this study, we have investigated potential application of 3D model-based learning material in training of new workers for production of electrical systems in the ship-building. Most of new trainees such as new employees or workers on job-transition have lots of difficulty when given the first task due to their poor ability to understand related engineering drawings. This is mainly caused by the fact that drawings are loaded with too many ambiguous symbols to precisely describe the characteristics of components required for installation of electrical equipments and cables. As one way to improve the ability of new employees to read drawings, we have suggested a new training method based on 3D models of major components required for production of the electrical systems in the ship.

Two-Dimensional Pilot Symbol Aided Channel Estimation for OFDM Systems over Frequency Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서 2-D PSA OFDM 시스템의 채널 추정)

  • 이병로
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1050-1055
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    • 2001
  • In this paper we analyze the performance of 2-D PSAM for wireless OFDM systems. We apply the analysis of single-carrier PSAM to the 2-D time-frequency lattice of OFDM. To estimate channel fading, we use interpolation filter which minimizes the average power of error as compensation method and analyze the affects on the system performance of the pilot symbol pattern on the 2-D time-frequency lattice. Finally according to the CP and the Doppler frequency, we analyze the performance of 2-D PSA-16QAM for OFDM systems over frequency selective Rayleigh fading channel model.

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Two-Dimensional Pilot Symbol Assisted Channel Estimation for OFDM Systems over Frequency Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서 OFDM 시스템을 위한 2-D PSA에 의한 채널 추정)

  • 이병로
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.336-340
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    • 2001
  • In this paper we analyze the performance of 2-D PSAM for wireless OFDM systems. We apply the analysis of single-carrier PSAM to the 2-D time-frequency lattice of OFDM. To estimate channel fading, we use interpolation filter which minimizes the average power of error as compensation method and analyze the affects on the system performance of the pilot symbol pattern on the 2-D tine-frequency lattice. Finally according to the CP and the Doppler frequency, we analyze the performance of 2-D PSA-16QAM for OFDM systems over frequency selective Rayleigh fading channel model.

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Positive Real Control for Uncertain 2-D Singular Roesser Models

  • Xu Huiling;Xie Lihua;Xu Shenyuan;Zou Yun
    • International Journal of Control, Automation, and Systems
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    • v.3 no.2
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    • pp.195-201
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    • 2005
  • This paper discusses the problem of positive real control for uncertain 2-D linear discrete time singular Roesser models (2-D SRM) with time-invariant norm-bounded parameter uncertainty. The purpose of this study is to design a state feedback controller such that the resulting closed-loop system is acceptable, jump modes free and stable, and achieves the extended strictly positive realness for all admissible uncertainties. A version of positive real lemma for the 2-D SRM is given in terms of linear matrix inequalities (LMIs). Based on the lemma, a sufficient condition for the solvability of the positive real control problem is derived in terms of bilinear matrix inequalities (BMIs) and an iterative procedure for solving the BMIs is proposed.