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A MAPREDUCE algorithm FOR MINIMUM VERTEX COVER PROBLEMS AND ITS RANDOMIZATION

COMPUTING AND INFORMATICS 2020年第5期39卷 952-972页

作者： Nakamura, Morikazu Kinjo, Daiki Yoshida, Takeo Univ Ryukyus Fac Engn Nishihara Okinawa 9030213 Japan

MapReduce is a programming paradigm for large-scale distributed information processing. This paper proposes a MapReduce algorithm for the minimum vertex cover problem, which is known to be NP-hard. The MapReduce algorithm can efficiently obtain a minimal vertex cover in a small number of rounds. We show the effectiveness of the algorithm through experimental evaluation and comparison with exact and approximate algorithms which demonstrates a high quality in a small number of MapReduce rounds. We also confirm from experimentation that the algorithm has good scalability allowing high-quality solutions under restricted computation times due to increased graph size. Moreover, we extend our algorithm to randomized one to obtain a good expected approximate ratio.

关键词： MapReduce minimum vertex cover Hadoop optimization algorithm design randomized algorithm

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Prufer Coding: A Vectorization Method for Undirected Labeled Graph

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IEEE ACCESS 2020年 8卷 175360-175369页

作者： Yang, Lin Wang, Yongjie Natl Univ Def Technol Coll Elect Engn Hefei 230037 Peoples R China Anhui Key Lab Cyberspace Secur Situat Awareness & Hefei 230037 Peoples R China

Prufer algorithm is a powerful method for topology vectorization, but the traditional prufer algorithm method can only encode a rootless labeled tree, and no prior work has studied the method of applying it to the graph vectorization. This paper proposes a vectorization method for undirected labeled graphs based on the prufer algorithm, including graph encoding and decoding algorithms. A particular case was discovered by preliminary experiments, which will reduce the accuracy of the coding algorithm (when the node size reaches more than 150, the accuracy can only reach about 60%), so a connectivity check mechanism that based on the Warshall algorithm is proposed and added to the coding algorithm. A large number of experimental verifications show that the accuracy of the coding algorithm can reach 100% after introducing this mechanism. Then the length of the vector generated by the coding algorithm is analyzed, and the results show that graph vectorization can improve the efficiency of partial topology calculation. Finally, the defects of the algorithm are discussed. The most significant defect is that the length of the vector generated by the encoding algorithm is uncertain, which will prevent it from being applied to more topological calculations.

关键词： Encoding Decoding Topology Network topology Licenses Skeleton Sorting Graph vectorization topology calculation prufer algorithm Warshall algorithm algorithm design

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Methane detection system based on a new type of dense optical multi-pass cell

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OPTIK 2022年 268卷

作者： Yang, Hongtao Peng, Jingjing Anhui Univ Sci & Technol Huainan 232001 Peoples R China Anhui Univ Sci & Technol Inst Environm friendly Mat & Occupat Hlth Wuhu 241003 Peoples R China

Objective: To increase the optical path of gas absorption in a multi-pass cell (MPC), a dense spot pattern has been obtained on MPC to improve the accuracy of trace gas detection. In this study, an algorithm was proposed to calculate the spot patterns of a new type of dense optical MPC. Method: In this novel algorithm, the reflected ray equation and spherical equation were combined to obtain the position coordinates of light spots on a mirror surface. The calculation was repeated by changing the reflected optical path parameters until a new dense light spot pattern was obtained. To verify the accuracy of the proposed algorithm, a series of spot numerical simulations and methane (CH4) concentration detection experiments were conducted. Results: Results showed that in an MPC with a double spherical mirror, a series of dense spot patterns located on the mirror surface was obtained by calculating off-axis incident rays using the new algorithm, effectively increasing optical path length, and obtaining an MPC with a long optical path of 12.92 m. CH4 concentration was detected by combining the long optical path MPC with a tunable diode laser absorption spectroscopy. A good linear relationship was established between the calibrated CH4 concentration and the peak of the second harmonic signal detected by the system. The minimum detection limit of the system for CH4 was 2.33 ppb at an integration time of 20 s obtained via Allan deviation analysis. The long optical path MPC system achieved high detection sensitivity. Hence, a new method for calculating the dense spot pattern of an MPC is provided in this work.

关键词： Long optical path Optical MPC algorithm design Dense spot pattern Trace gas detection Minimum detection limit

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Some upgrading problems on networks related to eccentricity concept

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OPTIMIZATION METHODS & SOFTWARE 2024年

作者： Sepasian, Ali Reza Nguyen, Kien Trung Fasa Univ Fac Basic Sci Dept Math Fasa *** Iran Can Tho Univ Teacher Coll Dept Math Can Tho Vietnam Can Tho Univ Teacher Coll Fac Math & Informat Can Tho Vietnam

This paper addresses optimization problems related to the concept of eccentricity in a network, specifically focussing on minimizing radius, diameter, and average eccentricity within a given budget. We refer to these problems as the upgrading radius problem, upgrading diameter problem, and upgrading average eccentricity problem, respectively. We prove that all of these problems are $ \mathcal {NP} $ NP-hard in general networks. Additionally, we propose an $ \mathcal {O}(n<^>3) $ O(n3) algorithm to solve the upgrading average eccentricity problem when the underlying graph is a tree. Furthermore, we demonstrate that the upgrading radius and upgrading diameter problems can also be solved in polynomial time for trees. Keywords: Eccentric vertex - Average eccentricity-Complexity-Trees-radius-diameter.

关键词： Upgrading problem complexity eccentric vertex algorithm design

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Lossless data compression method based on the characteristics of logging data

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Xi'an Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of Xi'an Shiyou University, Natural Sciences Edition 2006年第1期21卷 61-63+70页

作者： Han, Ze-Xi Guo, Feng Qin, Li-Ke College of Electronic Engineering Xi'an Shiyou University Xi'an 710065 China College of Geologic Measurement Chang'an University Xi'an 710061 China

The transmission efficiencies of combination logging data and imaging logging data are restricted under finite bandwidth. A lossless data compression method based on the characteristics of logging data is put forward, it can transfer the logging data to surface after they are compressed, and therefore the transmission efficiency of logging data is effectively improved. The compression plan, compression processing and algorithm are described. Different types of data are compressed using different compression methods, and the compression ratios of them are compared. It is shown that, the compression ratio of frame-related compression method is the greatest, and the compression ratios of other compression methods are smaller;the compression ratio of the first kind of data is greater, that of combination logging data is secondary, and that of imaging logging data is the least;the compression ratio slightly increases with the increase of the quantity of the data.

关键词： algorithm design Data transmission Logging data Lossless compression of data

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Free Angular-Positioning Wireless Power Transfer Using a Spherical Joint

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ENERGIES 2018年第12期11卷 3488-3488页

作者： Abou Houran, Mohamad Yang, Xu Chen, Wenjie Xi An Jiao Tong Univ Sch Elect Engn Xian 710049 Shaanxi Peoples R China

Many studies have investigated resonator structures and winding methods. The aims of this paper are as follows. First, the paper proposes an optimized winding model for a bio-inspired joint for a wireless power transfer (WPT) system. The joint consists of a small spherical structure, which rotates inside a hemispherical structure. The transmitter coil (Tx) is wound on the hemisphere structure, and the receiver coil (Rx) is wound on the small sphere. The power is transferred while rotating Rx over a wide range of angular misalignment. In addition, the algorithm design of the proposed winding method is given to get an optimized model. Moreover, the circuit analysis of the WPT system is discussed. Second, the magnetic field density is investigated considering a safety issue, which is linked to human exposure to electromagnetic fields (EMFs). Moreover, EMF mitigation methods are proposed and discussed in detail. Finally, the simulation results are validated by experiments, which have confirmed that the proposed winding method allows the system to rotate up to 85 degrees and achieve an efficiency above 86%. The proposed winding method for the WPT system can be a good technique for some robotic applications or a future replacement of the human joint.

关键词： algorithm design electromagnetic fields (EMFs) EMF shielding spherical structure wireless power transfer

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Revenue-maximizing virtualized network function chain placement in dynamic environment

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Future Generation Computer Systems 2020年 108卷 650-661页

作者： Yanghao Xie Sheng Wang Yueyue Dai School of Information and Communication Engineering University of Electronic Science and Technology of China Chengdu PR China

Network Function Virtualization (NFV) is a promising paradigm which can increase network flexibility by deploying newly network services into networks. Because of the flexibility, NFV is also considered as one of the building blocks for 5G and edge computing. However, the intrinsic dynamic features of NFV and the rigorous requirements proposed by 5G and edge computing, such as delay, pose significant challenges to make the optimal Virtual Network Function (VNF) chain placement. To address this problem, we first formulate the VNF chain placement problem as an integer linear programming problem with taking the dynamic characteristics in to consideration. Then we propose an efficient dynamic algorithm, called DynAmic vnF placemenT (DAFT), which provides a good solution for VNF chain placement. DAFT is based on primal–dual technique and combines with an efficient subroutine which is solved by reducing to the shortest path problem. The theoretic analysis shows DAFT is ( 1 − 1 ∕ e ) -competitive to offline optimal solution. We also propose a modified algorithm concerning algorithm implementation issues, which is called Feasible DAFT (FDAFT). Finally, we evaluate the proposed algorithms through extensive numerical simulations. The experiment results show that DAFT and FDAFT achieve average competitive ratios up to 98.42% and 96.74%, respectively and outperform the compared algorithms around 50%.

关键词： Network Function Virtualization Next generation networks Resource allocation algorithm design

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Enhanced Strapdown Attitude Computation

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2020年第6期43卷 1220-1224页

作者： Ignagni, Mario ASTER Labs Inc St Paul MN 55126 USA

A study is conducted to assess the implicit error associated with the use of the Goodman–Robinson rotation-vector equation in the presence of such angular motions, and to evaluate the potential of a simple algorithmic enhancement of this equation to improve attitude accuracy. The simplified Goodman–Robinson rotation-vector equation approximates the second term on the right-hand side of the first equation using the integral of the angular-rate vector instead of the rotation vector, with the third term being eliminated altogether. To determine the accuracy associated with the Goodman–Robinson rotation-vector equation, two angular-rate profiles are considered, such as a generalized angular rate and a coning angular rate.

关键词： Angular Motion Numerical Integration algorithm design Quaternions Vibration Isolation Strapdown Navigation Military Aviation Diminishing Returns Airborne Computers Aircraft Maneuvers

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Distorted Sparse Signal Estimation from Distributed Sign Measurements

Distorted Sparse Signal Estimation from Distributed Sign Mea...

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International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Cai, Xiao Zhang, Zhaoyang Zhong, Caijun Zhejiang Univ Inst Informat & Commun Engn Hangzhou 310027 Zhejiang Peoples R China

ISBN: (纸本)9781479903085

A novel algorithm called Cooperative Binary Iterative Hard Thresholding (CB-IHT) based on distributed 1-bit compressive sensing is proposed in this paper. Taking advantage of the correlated nature of distributed signal processing, the proposed algorithm is aimed to fight against the error floor in the estimation of distorted sparse signal, with an array of agents recovering the target signal cooperatively. The principles of convex optimization, consistent reconstruction and greedy pursuit algorithm are combined in the algorithm design. With two joint sparsity models representing distortion of equivalent parallel AWGN channels and parallel fading channels separately, the algorithm is performed through extensive simulations, which show that with severe distortion and large bit-budget, estimation accuracy can be improved by simply increasing the array scale.

关键词： Signal estimation error floor algorithm design AWGN channels Distribute distortion Pursuit algorithms fight abnormal shapes Bigeminy

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Optimal Rate Schedules with Data Sharing in Energy Harvesting Communication Systems

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SENSORS 2017年第12期17卷 2958-2958页

作者： Wu, Weiwei Li, Huafan Shan, Feng Zhao, Yingchao Southeast Univ Sch Comp Sci & Engn Nanjing 210018 Jiangsu Peoples R China Caritas Inst Higher Educ Sch Comp & Informat Sci Hong Kong 999077 Hong Kong Peoples R China

Despite the abundant research on energy-efficient rate scheduling polices in energy harvesting communication systems, few works have exploited data sharing among multiple applications to further enhance the energy utilization efficiency, considering that the harvested energy from environments is limited and unstable. In this paper, to overcome the energy shortage of wireless devices at transmitting data to a platform running multiple applications/requesters, we design rate scheduling policies to respond to data requests as soon as possible by encouraging data sharing among data requests and reducing the redundancy. We formulate the problem as a transmission completion time minimization problem under constraints of dynamical data requests and energy arrivals. We develop offline and online algorithms to solve this problem. For the offline setting, we discover the relationship between two problems: the completion time minimization problem and the energy consumption minimization problem with a given completion time. We first derive the optimal algorithm for the min-energy problem and then adopt it as a building block to compute the optimal solution for the min-completion-time problem. For the online setting without future information, we develop an event-driven online algorithm to complete the transmission as soon as possible. Simulation results validate the efficiency of the proposed algorithm.

关键词： wireless data transmission rate schedule data sharing energy-efficiency energy harvesting algorithm design

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