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Fusion of probabilistic A* algorithm and fuzzy inference system for robotic path planning

ARTIFICIAL INTELLIGENCE REVIEW 2010年第4期33卷 307-327页

作者： Kala, Rahul Shukla, Anupam Tiwari, Ritu IIITM Gwalior ABV Gwalior 47010 MP India

Robotic Path planning is one of the most studied problems in the field of robotics. The problem has been solved using numerous statistical, soft computing and other approaches. In this paper we solve the problem of robotic path planning using a combination of A* algorithm and Fuzzy Inference. The A* algorithm does the higher level planning by working on a lower detail map. The algorithm finds the shortest path at the same time generating the result in a finite time. The A* algorithm is used on a probability based map. The lower level planning is done by the Fuzzy Inference System (FIS). The FIS works on the detailed graph where the occurrence of obstacles is precisely known. The FIS generates smoother paths catering to the non-holonomic constraints. The results of A* algorithm serve as a guide for FIS planner. The FIS system was initially generated using heuristic rules. Once this model was ready, the fuzzy parameters were optimized using a Genetic Algorithm. Three sample problems were created and the quality of solutions generated by FIS was used as the fitness function of the GA. The GA tried to optimize the distance from the closest obstacle, total path length and the sharpest turn at any time in the journey of the robot. The resulting FIS was easily able to plan the path of the robot. We tested the algorithm on various complex and simple paths. All paths generated were optimal in terms of path length and smoothness. The robot was easily able to escape a variety of obstacles and reach the goal in an optimal manner.

关键词： Path planning Robotics Fuzzy inference system A* Algorithm Genetic algorithm Heuristics Probabilistic fitness hierarchical algorithms

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PRODUCTION CONTROL OF MANUFACTURING SYSTEMS - A MULTIPLE TIME-SCALE APPROACH

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IEEE TRANSACTIONS ON AUTOMATIC CONTROL 1994年第11期39卷 2292-2297页

作者： JIANG, J LOU, SXC UNIV TORONTO FAC MANAGEMENTTORONTO M5S 1V4ONCANADA

In this note, a stochastic production model containing processes with different time scales is developed. It is shown that if the time scales of the processes are very different, some hierarchical algorithms that are much more efficient than the standard policy iteration method can be developed to find the optimal production control. Moreover, if the time scales fall far apart, the optimal control of a deterministic limiting problem depending only on the mean characteristics of the processes can be used to approximate the optimal control of the original problem. The Limiting problem has much lower dimension than its original counterpart and thus is much easier to solve. A numerical example is used to illustrate the potential of the proposed approach.

关键词： dynamic programming optimal control production control deterministic limiting problem hierarchical algorithms manufacturing systems mean characteristics multiple time scale approach stochastic production model time scal production control dynamic programming Optimal control time scales Manufacturing systems

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Quantum-dot Cellular Automata Placement and Routing with hierarchical Algorithm

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NANO COMMUNICATION NETWORKS 2024年 39卷

作者： Zhang, Bing Peng, Fei Li, Gaisheng Li, Yangshuai Xie, Guangjun HeFei Univ Technol Sch Microelect Hefei Peoples R China Hebei Finance Univ Sch Comp & Informat Engn Baoding Hebei Peoples R China

To meet the needs of the market launch, placement and routing(P&R) algorithms for conventional circuits have started to adopt a hierarchical design, divide and conquer philosophy for the layout of VLSI circuits. Quantumdot cellular automata (QCA) circuits are considered a solution to overcome the limitations of Moore's Law. However, the current automated design of QCA circuits is still in its preliminary stages. This paper uses a hierarchical structure, which borrows from traditional circuits that should be laid out in large-scale circuits, to hierarchically process QCA circuits, laying them out layer by layer while using the A* algorithm for wiring to find feasible solutions. The algorithm is implemented using the C++ programming language, and simulation results verify the correctness of the algorithm.

关键词： Quantum -dot cellular automata Placement and routing hierarchical algorithms

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Characterization of the accuracy of the fast multipole method in particle simulations

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2009年第13期79卷 1577-1604页

作者： Cruz, Felipe A. Barba, L. A. Univ Bristol Dept Math Bristol BS8 1TW Avon England

The fast multipole method (FMM) is a fast summation algorithm capable of accelerating pairwise interaction calculations, known as N-body problems, from an algorithmic complexity of O(N-2) to O(N) for N particles. The algorithm has brought a dramatic increase in the capability of particle simulations in many application areas, such as electrostatics, particle formulations of fluid mechanics, and others. Although the literature on the subject provides theoretical error bounds for the FMM approximation, there are not many reports on the measured errors in a suite of computational experiments that characterize the accuracy of the method in relation with the different parameters available to the user. We have performed such an experimental investigation, and summarized the results of about 1500 calculations using the FMM algorithm, applied to the 2D vortex particle method. In addition to the more standard diagnostic of the maximum error, we supply illustrations of the spatial distribution of the errors, offering visual evidence of all the contributing factors to the overall approximation accuracy: multipole expansion, local expansion, hierarchical spatial decomposition (interaction lists, local domain, far domain). This presentation is a contribution to any researcher wishing to incorporate the FMM acceleration to their application code, as it aids in understanding where accuracy is gained or compromised. Copyright (C) 2009 John Wiley & Sons, Ltd.

关键词： fast multipole method order-N algorithms particle methods vortex method hierarchical algorithms

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PetFMM-A dynamically load-balancing parallel fast multipole library

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2011年第4期85卷 403-428页

作者： Cruz, Felipe A. Knepley, Matthew G. Barba, L. A. Boston Univ Dept Mech Engn Boston MA 02215 USA Univ Bristol Dept Math Bristol BS8 1TW Avon England Univ Chicago Computat Inst Chicago IL 60637 USA

Fast algorithms for the computation of N-body problems can be broadly classified into mesh-based interpolation methods, and hierarchical or multiresolution methods. To this latter class belongs the well-known fast multipole method (FMM), which offers O(N) complexity. The FMM is a complex algorithm, and the programming difficulty associated with it has arguably diminished its impact, being a barrier for adoption. This paper presents an extensible parallel library for N-body interactions utilizing the FMM algorithm. A prominent feature of this library is that it is designed to be extensible, with a view to unifying efforts involving many algorithms based on the same principles as the FMM and enabling easy development of scientific application codes. The paper also details an exhaustive model for the computation of tree-based N-body algorithms in parallel, including both work estimates and communications estimates. With this model, we are able to implement a method to provide automatic, a priori load balancing of the parallel execution, achieving optimal distribution of the computational work among processors and minimal inter-processor communications. Using a client application that performs the calculation of velocity induced by N vortex particles in two dimensions, ample verification and testing of the library was performed. Strong scaling results are presented with 10 million particles on up to 256 processors, including both speedup and parallel efficiency. The largest problem size that has been run with the PetFMM library at this point was 64 million particles in 64 processors. The library is currently able to achieve over 85% parallel efficiency for 64 processes. The performance study, computational model, and application demonstrations presented in this paper are limited to 2D. However, the software architecture was designed to make an extension of this work to 3D straightforward, as the framework is templated over the dimension. The software library is open sou

关键词： fast multipole method order-N algorithms particle methods vortex method hierarchical algorithms parallel computing dynamic load balancing

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Frozen-State hierarchical Annealing

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2013年第4期22卷 1484-1495页

作者： Campaigne, Wesley R. Fieguth, Paul W. Univ Waterloo Dept Syst Design Engn Waterloo ON N2L 3G1 Canada

There is significant interest in the synthesis of discrete-state random fields, particularly those possessing structure over a wide range of scales. However, given a model on some finest, pixellated scale, it is computationally very difficult to synthesize both large- and small-scale structures, motivating research into hierarchical methods. In this paper, we propose a frozen-state approach to hierarchical modeling, in which simulated annealing is performed on each scale, constrained by the state estimates at the parent scale. This approach leads to significant advantages in both modeling flexibility and computational complexity. In particular, a complex structure can be realized with very simple, local, scale-dependent models, and by constraining the domain to be annealed at finer scales to only the uncertain portions of coarser scales;the approach leads to huge improvements in computational complexity. Results are shown for a synthesis problem in porous media.

关键词： hierarchical algorithms image synthesis random sampling simulated annealing

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A Mathematical Theory for Clustering in Metric Spaces

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IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING 2016年第1期3卷 2-16页

作者： Chang, Cheng-Shang Liao, Wanjiun Chen, Yu-Sheng Liou, Li-Heng Natl Tsing Hua Univ Inst Commun Engn Hsinchu 300 Taiwan Natl Taiwan Univ Dept Elect Engn Taipei Taiwan

Clustering is one of the most fundamental problems in data analysis and it has been studied extensively in the literature. Though many clustering algorithms have been proposed, clustering theories that justify the use of these clustering algorithms are still unsatisfactory. In particular, one of the fundamental challenges is to address the following question: What is a cluster in a set of data points? In this paper, we make an attempt to address such a question by considering a set of data points associated with a distance measure (metric). We first propose a new cohesion measure in terms of the distance measure. Using the cohesion measure, we define a cluster as a set of points that are cohesive to themselves. For such a definition, we show there are various equivalent statements that have intuitive explanations. We then consider the second question: How do we find clusters and good partitions of clusters under such a definition? For such a question, we propose a hierarchical agglomerative algorithm and a partitional algorithm. Unlike standard hierarchical agglomerative algorithms, our hierarchical agglomerative algorithm has a specific stopping criterion and it stops with a partition of clusters. Our partitional algorithm, called the K-sets algorithm in the paper, appears to be a new iterative algorithm. Unlike the Lloyd iteration that needs two-step minimization, our K-sets algorithm only takes one-step minimization. One of the most interesting findings of our paper is the duality result between a distance measure and a cohesion measure. Such a duality result leads to a dual K-sets algorithm for clustering a set of data points with a cohesion measure. The dual K-sets algorithm converges in the same way as a sequential version of the classical kernel K-means algorithm. The key difference is that a cohesion measure does not need to be positive semi-definite.

关键词： Clustering hierarchical algorithms partitional algorithms convergence K-sets duality

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DISTRIBUTED COMPUTING FOR VISION - ARCHITECTURE AND A BENCHMARK TEST

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IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1985年第5期7卷 623-626页

作者： SELFRIDGE, PG MAHAKIAN, S VIEW ENGN SIMI VALLEYCA 93063

Computer vision algorithms are notorious for their computational expense. Distributed vision, the use of more than one processor, can decrease computation costs and speed up algorithms. There are various ways to do this, ranging from parallelism at the sensor level to true multiprocessor systems. This correspondence first describes a system of the latter type: a system of microprocessors on a high-speed bus. A canonical vision task, locating a number of objects and measuring certain two-dimensional features of those objects, serves as a benchmark test for the system. An algorithm for this task is presented. Performance measures are compared from implementations on the distributed system, a Vax 11/750, and a Vax 11/780. Results indicate that three microprocessors outperform a Vax 11/780 at this task. Finally, other more interesting distributed algorithms are briefly discussed.

关键词： Distributed computing Computer architecture Benchmark testing Computer vision Microprocessors Computational efficiency Parallel processing Sensor systems Multiprocessing systems System testing Author Keywords multiprocessor systems Computer vision distributed systems distributed vision hierarchical algorithms

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Revisiting the Combining Synchronization Technique 12

Revisiting the Combining Synchronization Technique

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17th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming

作者： Fatourou, Panagiota Kallimanis, Nikolas D. Univ Crete Dept Comp Sci Iraklion Greece Univ Ioannina Dept Comp Sci GR-45110 Ioannina Greece

ISBN: (纸本)9781450311601

Fine-grain thread synchronization has been proved, in several cases, to be outperformed by efficient implementations of the combining technique where a single thread, called the combiner, holding a coarse-grain lock, serves, in addition to its own synchronization request, active requests announced by other threads while they are waiting by performing some form of spinning. Efficient implementations of this technique significantly reduce the cost of synchronization, so in many cases they exhibit much better performance than the most efficient finely synchronized algorithms. In this paper, we revisit the combining technique with the goal to discover where its real performance power resides and whether or how ensuring some desired properties (e.g., fairness in serving requests) would impact performance. We do so by presenting two new implementations of this technique;the first (CC-Synch) addresses systems that support coherent caches, where as the second (DSM-Synch) works better in cacheless NUMA machines. In comparison to previous such implementations, the new implementations (1) provide bounds on the number of remote memory references (RMRs) that they perform, (2) support a stronger notion of fairness, and (3) use simpler and less basic primitives than previous approaches. In all our experiments, the new implementations out perform by far all previous state-of-the-art combining-based and fine-grain synchronization algorithms. Our experimental analysis sheds light to the questions we aimed to answer. Several modern multi-core systems organize the cores into clusters and provide fast communication within the same cluster and much slower communication across clusters. We present an hierarchical version of CC-Synch, called H-Synch which exploits the hierarchical communication nature of such systems to achieve better performance. Experiments show that H-Synch significantly outpperforms previous state-of-the-art hierarchical approaches. We provide new implementations of co

关键词： algorithms Experimentation Theory Performance Synchronization techniques combining hierarchical algorithms blocking algorithms concurrent data structures

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Dynamic Probabilistic Forwarding in Wireless Ad Hoc Networks Based on Game Theory 79

Dynamic Probabilistic Forwarding in Wireless Ad Hoc Networks...

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IEEE 79th Vehicular Technology Conference (VTC-Spring)

作者： Naserian, Mohammad Tepe, Kemal Hyundai Kia Amer Tech Ctr Superior Charter Townshi MI 48198 USA Univ Windsor Dept Elect & Comp Engn Windsor ON N9B 3P4 Canada

ISBN: (纸本)9781479944828

This paper proposes a Forwarding Game Routing Protocol (FGRP), which can be applied to any routing protocol in mobile ad hoc network (MANET) such as Ad Hoc On Demand Distance Vector (AODV) [1] and Dynamic Source Routing (DSR) [2] routing protocols. A node enters the forwarding game upon receiving a flooding packet. In this game, nodes select one of the following mixed strategies: (1) forwarding and (2) not-forwarding. The strategy changes based on player's utility, which is a function of its availability, selected strategy and forwarding probability of other nodes. Each node tries to maximize its utility by selecting the appropriate strategy. Parameters such as residual energy level, channel congestion, number of packets in the node's transmission queue, and the distance from the source of the flooding packet are included in the availability. Since the forwarding decision is made locally by every node, unlike clustering or hierarchical algorithms, there is no extra overhead involved. This paper presents the performance improvement results of FGRP integrated with AODV in network simulator NS-2. Simulation results show that integrating FGRP with AODV improves network performance metrics such as end-to-end delay per packet, and packet delivery ratio.

关键词： game theory mobile ad hoc networks packet radio networks routing protocols AODV FGRP MANET NS-2 network simulator ad hoc on demand distance vector channel congestion dynamic probabilistic forwarding dynamic source routing flooding packet forwarding game routing protocol hierarchical algorithms mobile ad hoc network residual energy level wireless ad hoc networks Availability Games Mobile ad hoc networks Routing Routing protocols Silicon Mobile ad hoc networks Game theory Routing protocols glass fibre reinforced plastics Packet radio networks AODV Network routing Packet

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