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A Novel Concept for Guidance and Control of Spacecraft Orbital Maneuvers

INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING 2016年第Pt.2期2016卷 7695257.1-7695257.1页

作者： Dentis, Matteo Capello, Elisa Guglieri, Giorgio Politecn Torino Dept Mech & Aerosp Engn Corso Duca Abruzzi 24 I-10129 Turin Italy Politecn Torino Dept Mech & Aerosp Engn CNR IEIIT Corso Duca Abruzzi 24 I-10129 Turin Italy

The purpose of this paper is the design of guidance and control algorithms for orbital space maneuvers. A 6-dof orbital simulator, based on Clohessy-Wiltshire-Hill equations, is developed in C language, considering cold gas reaction thrusters and reaction wheels as actuation system. The computational limitations of on-board computers are also included. A combination of guidance and control algorithms for an orbital maneuver is proposed: (i) a suitably designed Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) algorithm is adopted for the guidance and (ii) a linear quadratic regulator (LQR) is used for the attitude control. The proposed approach is verified for different cases, including external environment disturbances and errors on the actuation system.

关键词： Activation reaction wheels orbital maneuvers Space simulators computer algorithms Guidance C language spacecraft control linear quadratic regulators

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Efficient binary search space-structured VQ encoder applied to a line spectral frequency quantisation in G.729 standard

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IET COMMUNICATIONS 2016年第10期10卷 1183-1188页

作者： Lin, Tzu-Hung Yeh, Cheng-Yu Hwang, Shaw-Hwa Chang, Shun-Chieh Natl Taipei Univ Technol Dept Elect Engn 1Sec 3Chung Hsiao E Rd Taipei 10608 Taiwan Natl Chin Yi Univ Technol Dept Elect Engn 57Sec 2Zhongshan Rd Taichung 41170 Taiwan

This study presents a simple but high performance vector quantisation (VQ) codebook search algorithm for line spectral frequency quantisation in ITU-T G.729 speech codec, designated as the binary search space-structured VQ (BSS-VQ) algorithm. This is done through a combined use of a fast locating technique and lookup tables, such that an input vector, ahead of VQ encoding, is assigned efficiently to a subspace where merely a small number of codeword searches are required to be performed. As a consequence, the computational load is reduced remarkably. A trade-off can be made easy to meet a user's requirement when performing VQ encoding. It is experimentally validated that a search accuracy is well maintained at 99% approximately for a threshold of quantisation accuracy of 0.99. More importantly, with a full search algorithm as a benchmark for search load comparison, this proposal provides a 85% search load reduction, a figure far beyond 43% in multiple triangular inequality elimination approach, 47% in TIE with dynamic and intersection rules and 59% in quasi-binary search VQ algorithm.

关键词： computer algorithms Encoding Subspaces (Mathematics) Topological spaces Electrical engineering

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Decision Diagram Based Symbolic Algorithm for Evaluating the Reliability of a Multistate Flow Network

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MATHEMATICAL PROBLEMS IN ENGINEERING 2016年第1期2016卷 1-13页

作者： Dong, Rongsheng Zhu, Yangyang Xu, Zhoubo Li, Fengying Guilin Univ Elect Technol Sch Comp Sci & Engn Guangxi Key Lab Trusted Software Guilin 541004 Peoples R China

Evaluating the reliability of Multistate Flow Network (MFN) is an NP-hard problem. Ordered binary decision diagram (OBDD) or variants thereof, such as multivalued decision diagram (MDD), are compact and efficient data structures suitable for dealing with large-scale problems. Two symbolic algorithms for evaluating the reliability of MFN, MFN OBDD and MFN MDD, are proposed in this paper. In the algorithms, several operating functions are defined to prune the generated decision diagrams. Thereby the state space of capacity combinations is further compressed and the operational complexity of the decision diagrams is further reduced. Meanwhile, the related theoretical proofs and complexity analysis are carried out. Experimental results show the following: (1) compared to the existing decomposition algorithm, the proposed algorithms take less memory space and fewer loops. (2) The number of nodes and the number of variables of MDD generated in MFN MDD algorithm are much smaller than those of OBDD built in the MFN OBDD algorithm. (3) In two cases with the same number of arcs, the proposed algorithms are more suitable for calculating the reliability of sparse networks.

关键词： computer algorithms DATA structures (computer science) DECOMPOSITION (Mathematics) DECISION making SYMBOLISM

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Comparison of Dose Distributions With TG-43 and Collapsed Cone Convolution algorithms Applied to Accelerated Partial Breast Irradiation Patient Plans

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INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 2016年第5期95卷 1520-1526页

作者： Thrower, Sara L. Shaitelman, Simona F. Bloom, Elizabeth Salehpour, Mohammad Gifford, Kent Univ Texas MD Anderson Canc Ctr Univ Texas Grad Sch Biomed Sci Houston Houston TX 77030 USA Univ Texas MD Anderson Canc Ctr Dept Radiat Oncol Houston TX 77030 USA Univ Texas MD Anderson Canc Ctr Dept Radiat Phys Univ Texas Grad Sch Biomed Sci Houston Houston TX 77030 USA

Purpose: To compare the treatment plans for accelerated partial breast irradiation calculated by the new commercially available collapsed cone convolution (CCC) and current standard TG-43-based algorithms for 50 patients treated at our institution with either a Strut-Adjusted Volume Implant (SAVI) or Contura device. Methods and Materials: We recalculated target coverage, volume of highly dosed normal tissue, and dose to organs at risk (ribs, skin, and lung) with each algorithm. For 1 case an artificial air pocket was added to simulate 10% nonconformance. We performed a Wilcoxon signed rank test to determine the median differences in the clinical indices V90, V95, V100, V150, V200, and highest-dosed 0.1 cm(3) and 1.0 cm(3) of rib, skin, and lung between the two algorithms. Results: The CCC algorithm calculated lower values on average for all dose-volume histogram parameters. Across the entire patient cohort, the median difference in the clinical indices calculated by the 2 algorithms was < 10% for dose to organs at risk, < 5% for target volume coverage (V90, V95, and V100), and < 4 cm(3) for dose to normal breast tissue (V150 and V200). No discernable difference was seen in the nonconformance case. Conclusions: We found that on average over our patient population CCC calculated (<10%) lower doses than TG-43. These results should inform clinicians as they prepare for the transition to heterogeneous dose calculation algorithms and determine whether clinical tolerance limits warrant modification. (C) 2016 Elsevier Inc. All rights reserved.

关键词： RADIOTHERAPY treatment planning RADIATION doses BREAST cancer treatment computer algorithms WILCOXON signed-rank test COHORT analysis

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Modeling Multioperator Multi-UAV Operator Attention Allocation Problem Based on Maximizing the Global Reward

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MATHEMATICAL PROBLEMS IN ENGINEERING 2016年第1期2016卷 1-8页

作者： Wu, Yuhang Huang, Zhonghua Li, Yinlin Wang, Zhiqi Beijing Inst Technol Sch Mechatron Engn Beijing 100081 Peoples R China

This paper focuses on the attention allocation problem (AAP) in modeling multioperator multi-UAV (MOMU), with the operator model and task properties taken into consideration. Themodel ofMOMUoperator AAP based onmaximizing the global reward is established and used to allocate tasks to all operators as well as set work time and rest time to each task simultaneously for operators. The proposed model is validated in Matlab simulation environment, using the immune algorithm and dynamic programming algorithm to evaluate the performance of the model in terms of the reward value with regard to the work time, rest time, and task allocation. The result shows that the total reward of the proposed model is larger than the one obtained from previously published methods using local maximization and the total reward of our method has an exponent-like relation with the task arrival rate. The proposed model can improve the operators' task processing efficiency in the MOMU command and control scenarios.

关键词： DRONE aircraft ASSIGNMENT problems (Programming) computer algorithms DYNAMIC programming

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Nuclear Power Plant Construction Scheduling Problem with Time Restrictions: A Particle Swarm Optimization Approach

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SCIENCE AND TECHNOLOGY OF NUCLEAR INSTALLATIONS 2016年第4-11期2016卷 1-9页

作者： Chen, Shang-Kuan Ti, Yen-Wu Tsai, Kuo-Yu Yuanpei Univ Med Technol Dept Comp Sci & Informat Engn Hsinchu 23568 Taiwan Hwa Hsia Univ Technol Dept Comp Sci & Informat Engn 111 Gong Jhuan Rd Taipei 23568 Taiwan Chinese Culture Univ Dept Appl Math 55 Hwa Kang Rd Taipei 11114 Taiwan

In nuclear power plant construction scheduling, a project is generally defined by its dependent preparation time, the time required for construction, and its reactor installation time. The issues of multiple construction teams and multiple reactor installation teams are considered. In this paper, a hierarchical particle swarm optimization algorithm is proposed to solve the nuclear power plant construction scheduling problem and minimize the occurrence of projects failing to achieve deliverables within applicable due times and deadlines.

关键词： NUCLEAR power plants -- Design & construction computer scheduling PARTICLE swarm optimization NUCLEAR reactors computer algorithms

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Twelve Years of QBF Evaluations: QSAT Is PSPACE-Hard and It Shows

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FUNDAMENTA INFORMATICAE 2016年第1-2期149卷 133-158页

作者： Marin, Paolo Narizzano, Massimo Pulina, Luca Tacchella, Armando Giunchiglia, Enrico Lehrstuhl Rechnerarchitektur Georges Kohler Allee 051 D-79110 Freiburg Germany Univ Genoa DIBRIS Via Opera Pia 13 I-16145 Genoa Italy Univ Sassari POLCOMING Viale Mancini 5 I-07100 Sassari Italy

Twelve years have elapsed since the first Quantified Boolean Formulas (QBFs) evaluation was held as an event linked to SAT conferences. During this period, researchers have striven to propose new algorithms and tools to solve challenging formulas, with evaluations periodically trying to assess the current state of the art. In this paper, we present an experimental account of solvers and formulas with the aim to understand the progress in the QBF arena across these years. Unlike typical evaluations, the analysis is not confined to the snapshot of submitted solvers and formulas, but rather we consider several tools that were proposed over the last decade, and we run them on different formulas from previous QBF evaluations. The main contributions of our analysis, which are also the messages we would like to pass along to the research community, are: (i) many formulas that turned out to be difficult to solve in past evaluations, remain still challenging after twelve years, (ii) there is no single solver which can significantly outperform all the others, unless specific categories of formulas are considered, and (iii) effectiveness of preprocessing depends both on the coupled solver and the structure of the formula.

关键词： computer algorithms COMPUTATIONAL complexity PROBLEM solving MATHEMATICAL formulas MACHINE theory

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A fast and robust method of calculating RFM parameters for satellite imagery

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REMOTE SENSING LETTERS 2016年第12期7卷 1112-1120页

作者： Wu, Yingdan Ming, Yang Hubei Univ Technol Sch Sci Wuhan Peoples R China Hubei Univ Technol Hubei Collaborat Innovat Ctr High Efficient Utili Wuhan Peoples R China CCCC Second Highway Consultants Co Ltd Wuhan Peoples R China

Since the normal matrix is often ill-conditioned when solving Rational Function Model (RFM) for the satellite remote sensing imagery, combining with matrix orthogonal decomposition, Levenberg-Marquardt algorithm and Compute Unified Device Architecture high-performance computing technique, a fast and robust method directly based on the error equation coefficient matrix is proposed. The method is analysed by different parameters of control point grid and compared with the common methods, namely L-curve based ridge estimation and Iteration by Correcting Characteristic Value. The experimental results show that RFM parameters derived by ourmethod have higher fitting accuracy.

关键词： REMOTE-sensing images ORTHOGONAL functions DECOMPOSITION method (Mathematics) computer algorithms CUDA (computer architecture)

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FastSLAM Using Compressed Occupancy Grids

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JOURNAL OF SENSORS 2016年第7-5期2016卷 1-23页

作者： Cain, Christopher Leonessa, Alexander SEW EURODRIVE Lyman SC 29365 USA Virginia Tech Dept Mech Engn Ctr Dynam Syst Modeling & Control Blacksburg VA 24061 USA

Robotic vehicles working in unknown environments require the ability to determine their location while learning about obstacles located around them. In this paper a method of solving the SLAM problem that makes use of compressed occupancy grids is presented. The presented approach is an extension of the FastSLAM algorithm which stores a compressed form of the occupancy grid to reduce the amount of memory required to store the set of occupancy grids maintained by the particle filter. The performance of the algorithm is presented using experimental results obtained using a small inexpensive ground vehicle equipped with LiDAR, compass, and downward facing camera that provides the vehicle with visual odometry measurements. The presented results demonstrate that although with our approach the occupancy grid maintained by each particle uses only 40% of the data needed to store the uncompressed occupancy grid, we can still achieve almost identical results to the approach where each particle filter stores the full occupancy grid.

关键词： computer algorithms SLAM (Robotics) LIDAR (Optics) Laser based sensors Autonomous vehicles

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Xilmass: A New Approach toward the Identification of Cross-Linked Peptides

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ANALYTICAL CHEMISTRY 2016年第20期88卷 9949-9957页

作者： Yilmaz, Sule Drepper, Friedel Hulstaert, Niels Cernic, Masa Gevaert, Kris Economou, Anastassios Warscheid, Bettina Martens, Lennart Vandermarliere, Elien VIB Med Biotechnol Ctr B-9000 Ghent Belgium Univ Ghent Dept Biochem B-9000 Ghent Belgium Univ Ghent Bioinformat Inst Ghent B-9000 Ghent Belgium Univ Freiburg Fac Biol Inst Biol 2 Dept Biochem & Funct Prote D-79104 Freiburg Germany Univ Freiburg BIOSS Ctr Biol Signaling Studies D-79104 Freiburg Germany Ctr Excellence Integrated Approaches Chem & Biol Jamova Cesta 39 Ljubljana 1000 Slovenia Univ Ljubljana Fac Med Ljubljana 1000 Slovenia KU Leuven Univ Leuven Dept Microbiol & Immunol Rega Inst Med Res Lab Mol Bacteriol B-3000 Leuven Belgium Univ Crete Inst Mol Biol & Biotechnol FoRTH Iraklion 71100 Crete Greece Univ Crete Dept Biol Iraklion 71100 Crete Greece

Chemical cross-linking coupled with mass spectrometry plays an important role in unravelling protein interactions, especially weak and transient ones. Moreover, crosS-linking complements several structural determination approaches such as cryo:EM. Although several computational approaches are available for the annotation of spectra obtained from cross-linked peptides, there remains room for improvement. Here, we present Xilmass, a novel algorithm to identify cross-linked peptides that introduces two new concepts: (i) the cross-linked peptides are represented in the search database such that the cross-linking sites are explicitly encoded, and (ii) the scoring function derived from the Andromeda algorithm was adapted to score against a theoretical tandem mass spectrometry (MS/MS) spectrum that contains the peaks from all possible fragment ions of a cross-linked peptide pair. The performance of Xilmass was evaluated against the recently published Kojak and the popular pLink algorithms on a calmodulin-plectin complex data set, as well as three additional, published: data sets. The results show that Xilmass typically had cross-linked sites and also the highest number of predicted cross-linked sites.

关键词： PEPTIDES RESEARCH CROSSLINKING (Polymerization) MASS spectrometry PROTEIN-protein interactions computer algorithms DAUGHTER ions

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