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Effective loading algorithm associated with explicit dynamic relaxation method for simulating static problems

Journal of Central South University 2009年第1期16卷 125-130页

作者：赵崇斌彭省临刘亮明 HOBBS B E ORD A Computational Geosciences Research Centre Central South University CSIRO Division of Exploration and Mining P. O. Box 1130

Based on the fact that a static problem has an equivalent wave speed of infinity and a dynamic problem has a wave speed of finite value, an effective loading algorithm associated with the explicit dynamic relaxation method was presented to produce meaningful numerical solutions for static problems. The central part of the explicit dynamic relaxation method is to turn a time-independent static problem into an artificial time-dependent dynamic problem. The related numerical testing results demonstrate that: (1) the proposed effective loading algorithm is capable of enabling an applied load in a static problem to be propagated throughout the whole system within a given loading increment, so that the time-independent solution of the static problem can be obtained; (2) the proposed effective loading algorithm can be straightforwardly applied to the particle simulation method for solving a wide range of static problems.

关键词： numerical simulation static systems dynamic relaxation loading algorithm

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Performance Enhancement of OFDM System in indoor Wireless Channels using loading algorithm

Performance Enhancement of OFDM System in indoor Wireless Ch...

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2nd International Conference on Developments in eSystems Engineering

作者： Jameel, Ahmed J. Adnan, Hadeel Hussain, Abir J. Bi Guangguo Ahlia Univ Coll Engn Dept Telecommun Engn Manama Bahrain Southeast Univ Dept Radio Engn Natl Mobile Commun Res lab Nanjing 210096 Peoples R China

In this paper, we consider a simple loading algorithm for Orthogonal Frequency Division Multiplexing systems in WLAN for signal spectrum optimization. The algorithm is based on the margin adaptive loading criterion an... 详细信息

ISBN: (纸本)9781424454013

关键词： loading algorithm OFDM WLAN

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A Minimum BER loading algorithm for OFDM in Access Power Line Communications

A Minimum BER Loading Algorithm for OFDM in Access Power Lin...

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5th Annual International ICST Conference on Access Networks (AccessNets 2010)

作者： Wang, Linyu Deconinck, Geert Van Lil, Emmanuel Katholieke Univ Leuven Dept Elect Engn Div ESAT Telem Kasteel Arenbergpk 10Bus 2444 B-3001 Heverlee Belgium Katholieke Univ Leuven Dept Elect Engn Div ESAT ELECTA B-3001 Heverlee Belgium

ISBN: (纸本)9783642209307

In this paper, we investigate the resource allocation problem for access broadband power line communications (PLC) according to the OPERA specification for power grids monitoring and control. The proposed loading algorithm attempts to minimize the BER while guaranteeing a certain throughput for Amplitude Differential Phase Shift Keying (ADPSK) modulation, when the attenuation varies significantly in function of the frequency. A performance comparison between the proposed algorithm and the Fischer-Huber algorithm is also discussed. Numerical simulations show that the proposed method can improve the average BER performance.

关键词： Broadband Power line communications high attenuation variance loading algorithm

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loading algorithms for subband coded image transmission using multicarrier modulation

Loading algorithms for subband coded image transmission usin...

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Meeting on Visual Communications and Image Processing

作者： Zheng, H Liu, KJR Univ Maryland Syst Res Inst College Pk MD 20742 USA

ISBN: (纸本)0819431249

We present a new parallel framework for multimedia data transmission over spectrally shaped channels using multicarrier modulation. Source images are first decomposed into a set of layers with different perceptual importance. Unlike the traditional approaches, the layers are transmitted simultaneously, each occupying a number of subchannels. We develop parallel loading algorithms which distribute the transmitted power and data rate among the subchannels efficiently, to provide unequal error protection. A power optimized serial transmission system is also developed. Simulation results show that the parallel transmission system achieve significant performance improvement compared to the optimized serial transmission and the existing loading algorithms developed far data transmission. Performance comparison under different parameters are also presented. The proposed algorithms are well suited for both Additive Gaussian White Noise(AGWN) channels and spectrally shaped channels which are typical in ADSL systems. Numerical comparison for different parameters are also given.

关键词： subband coding multicarrier modulation spectrally shaped channel loading algorithm

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Pickup capacitated vehicle routing problem with three-dimensional loading constraints: Model and algorithms

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TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW 2023年第1期176卷

作者： Chi, Jushang He, Shiwei Beijing Jiaotong Univ Key Lab Transport Ind Big Data Applicat Technol Co Beijing Peoples R China

This study addresses the pickup capacitated vehicle routing problem with three-dimensional loading constraints (3L-PCVRP), which combined the container loading problem (CLP) and the capacitated vehicle routing problem (CVRP). A mixed-integer linear programming model for 3LPCVRP is designed with the objective of minimizing the total transportation cost. The basic constraints of CLP and CVRP as well as the practical constraints imposed by the pickup operations are incorporated in 3L-PCVRP. An improved branch-and-price-based (B & P) algorithm is proposed to solve 3L-PCVRP. The 3L-PCVRP model is decomposed into the restricted master problem (RMP) for selecting routes and the subproblem (SP) for generating routes that satisfy the loading and routing constraints. A label-correcting-based algorithm (LCA) is presented to solve the SP, which employs a two-stage method and two enhanced loading algorithms to ensure the loading feasibility of the routes. The two loading algorithms (tree search and greedy heuristic algorithms) are improved by a new evaluation function and an improved space-merging method. The twostage method is designed to call the two loading algorithms at different frequencies to investigate the route feasibility accurately and efficiently. Numerical experiments are designed to test the performance of the proposed algorithms. The efficiency and effectiveness of the improved loading algorithms are demonstrated in hundreds randomly generated instances. For small-scale 3L-PCVRP instances, the B & P algorithm can generate solutions that are not worse than those of the solver within 0.14% of the solver's running time. The efficiency and effectiveness of the improved B & P algorithm are also validated in large-scale benchmark instances.

关键词： Three-dimensional loading Routing Pickup operation loading algorithm Branch-and-price algorithm

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Computationally efficient optimal-power allocation algorithms for multicarrier communication systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 2000年第1期48卷 23-27页

作者： Krongold, BS Ramchandran, K Jones, DL Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA Univ Illinois Coordinated Sci Lab Urbana IL 61801 USA

In this paper, we present an optimal, computationally efficient, integer-bit power allocation algorithm for discrete multitone modulation. Using efficient lookup table searches and a Lagrange-multiplier bisection search, our algorithm converges faster to the optimal solution than existing techniques and can replace the use of suboptimal methods because of its low computational complexity. Fast algorithms are developed for the data rate and performance margin maximization problems.

关键词： discrete multitone modulation loading algorithm multicarrier communication systems power allocation

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Rate-maximized adaptive MIMO systems with channel state information feedback delays

Rate-maximized adaptive MIMO systems with channel state info...

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International Symposium on Communications and Information Technologies (ISCIT2005)

作者： Song, Y Yang, DC Beijing Univ Posts & Telecommun Sch Telecommun Engn Beijing 100088 Peoples R China

ISBN: (纸本)0780395387

This paper discusses rate-maximized adaptive modulation for multiple-input multiple-output (MIMO) systems and its receiver detection procedure when channel state information (CSI) feedback is of feedback period and delay. A set of equivalent parallel fading subchannels is obtained by singular value decomposition (SVD). The fading factors and independence of the subchannels in the ideal case when the precise CSI is available at the transmitter are altered due to the time-varying characteristics of wireless MIMO channels. However, the correlation remains within a very short period of time. Zero forcing (ZF) and interference cancellation (IC) are adopted at the receiver to improve the performance.

关键词： MIMO adaptive modulation feedback loading algorithm

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Optimization of Aviation Baggage Online Stacking Planning algorithm based on Hierarchical Tree A2C Reinforcement Learning

Optimization of Aviation Baggage Online Stacking Planning Al...

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2023智能制造与机械动力学学术大会

作者： TIAN Jintao ZHANG Pan ZHANG Wei College of Aeronautical Engineering CAUC Key Laboratory of Smart Airport Theory and System CAAC Aviation Special Ground Equipment Research Base CAAC

In order to solve the critical loading algorithm problem in aviation baggage automated loading,this paper proposes a hierarchical tree A2C reinforcement learning framework for online stacking planning of aviation *** hierarchical tree search module utilizes the hierarchical tree search strategy to represent the required external environment information in a node-based manner and outputs it as the input of the deep reinforcement learning *** deep reinforcement learning A2C framework includes the baggage-trolley model,airport baggage constraints,improved reward function,action space,and state *** loading strategy of the hierarchical tree search is improved by fully considering the information of all baggage to adjust the selection probability of leaf *** on the characteristics of aviation baggage loading,constraints such as direction,volume,non-overlap,and stability are established to maximize the utilization of the baggage cart body *** improved reward function comprehensively considers the volume of the current stacking baggage,stacking position,wasted space,and collision interference during the arm stacking *** adopts the Family Unity concept and classifies aviation baggage according to size range,effectively guiding the convergence direction and improving space utilization while ensuring loading *** validate the effectiveness of the algorithm,the proposed algorithm is compared with BR,LSAH,discretization deep reinforcement learning algorithm,OnlineBPH,and other algorithms based on the established aviation baggage *** experimental results show that the average stacking filling rate of the proposed method is 71.2%,which is 8.5% higher than that of selected similar algorithms and has a faster computation *** experimental platform was built,and the experimental results verified the effectiveness of the proposed *** conclusion,the proposed hierarchical tree A2C reinforcement learning framework provides a

关键词： Hierarchical tree search Reinforcement learning Stacking planning Aviation baggage loading algorithm Space utilization

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