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Abstract

Non-orthogonal multiple access (NOMA) has received tremendous attention for the development of 5G and beyond wireless networks. Power-domain NOMA works on the concept of assigning varying power levels to users within the same frequency and time block. In this paper we propose a novel power allocation approach that uses the Zipf distribution law that satisfies the basic condition of a NOMA system. The Zipf PA is characterized by the simplicity and ease of implementation that allows to extend the capacity of the system to support a large number of users. The numerical results show that the system achieves high throughput and energy efficiency without any parameter optimization constraints as well as improved capacity by increasing the number of users compared to the NOMA system with existing power allocation techniques.
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Authors and Affiliations

Hanane Himeur
1
Sidi Mohammed Meriah
1
Fouad Derraz
1

  1. Faculty of Technology, University of Abou Bekr Belkaid, Tlemcen, Algeria
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Abstract

The paper introduces the distributed framework for determining the shortest path of robots in the logistic applications, i.e. the warehouse with a swarm of robots cooperating in the Real- Time mode. The proposed solution uses the optimization routine to avoid the downtime and collisions between robots. The presented approach uses the reference model based on Dijkstra, Floyd- Warshall and Bellman-Ford algorithms, which search the path in the weighted undirected graph. Their application in the onboard robot’s computer requires the analysis of the time efficiency. Results of comparative simulations for the implemented algorithms are presented. For their evaluation the data sets reflecting actual processes were used. Outcomes of experiments have shown that the tested algorithms are applicable for the logistic purposes, however their ability to operate in the Real-Time requires the detailed analysis.
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Bibliography

[1] Mobile Robot Platforms, Shuttle Automated Storage and Retrieval Systems, Industrial Robotic Manipulators, and Gantry Robots: Global Market Analysis and Forecasts, Informa PLC, https://www.tractica.com/research/warehousing-and-logistics-robots/
[2] J. Miklinska, “Trends in the logistic market and warehouses for logistics service providers-experiences from Poland,” Economic and Social Development: Book of Proceedings, 2020, 193-202.
[3] M. Khamphroo, N. Kwankeo, K. Kaemarungsi, K. Fukawa, “MicroPython-based educational mobile robot for computer coding learning,” 2017 8th International Conference of Information and Communication Technology for Embedded Systems (IC-ICTES), Chonburi, 2017.
[4] K. Dokic, B. Radisic, M. Cobović, “MicroPython or Arduino C for ESP32 - Efficiency for Neural Network Edge Devices,” Springier, 2020, pp.33-34, https://doi.org/10.1007/978-3-030-43364-2_4.
[5] N. Deo, “Graph theory with applications to engineering and computer science,” Englewood Cliffs, NJ: Prentice-Hall, 1974.
[6] G. Laporte, ”The traveling salesman problem: An overview of exact and approximate algorithms,” EJOR, 1992, Vol.59, pp. 231-247.
[7] Lu Feng, “Shortest path algorithm: Taxonomy and Advance in Research”, Acta Geodaetica et Cartographica Sinica, vol. 30, no. 3, pp. 269-275, 2001.
[8] D. Dobrilovic, V. Jevtic, I. Beker, Z. Stojanov, “Shortest-path based Model for Warehouse Inner Transportation Optimization” in 7th IEEE International Symposium on Applied Computational Intelligence and Informatics (SACI)
[9] Y. Liu, T. M. Vitolo, “Graph Data Warehouse: Steps to Integrating Graph Databases Into the Traditional Conceptual Structure of a Data Warehouse,” 2013 IEEE International Congress on Big Data, 2013, pp. 433-434, https://doi.org/10.1109/BigData.Congress.2013.72
[10] H.Y. Jang, J.U. Sun, “A Graph Optimization Algorithm for Warehouses with Middle Cross Aisles,” Applied Mechanics and Materials, 2011, 145. 354-358, https://doi.org/10.4028/www.scientific.net/AMM.145.354.
[11] B.D. Acharya, M.K. Gill, “On the Index of Gracefulness of a Graph and the Gracefulness of Two-Dimensional Square Lattice Graphs, ” Indian J. Math., 1981, 23, 81-94.
[12] T.H. Cormen, C.E. Leiserson, and R.L. Rivest, “Introduction to algorithms,” MIT Press, 1994.
[13] Warehouse material flows and flow charts, https://www.mecalux.co.uk/warehouse-manual/warehouse-design/warehouse-material-flowchart
[14] A. Niemczyk et al., “Organizacja i monitorowanie procesów magazynowych,” Instytut Logistyki i Magazynowania, 2014.
[15] A. Szymonik, D. Chudzik, “Logistyka nowoczesnej gospodarki magazynowej,” Difin, 2018.
[16] B. Mbakop A. Kevine, “The Effectiveness of ABC Cross Analysis on Products Allocation in the Warehouse,” 2018, January – February, Vol. 5, Issue 1, pp: 11-30.
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Authors and Affiliations

Tomasz Markowski
1
Piotr Bilski
2
ORCID: ORCID

  1. Lukasiewicz – Institute of Logistics and Warehousing, Poland
  2. Warsaw University of Technology, Poland
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Abstract

This paper presents experimental observation of nonlinear vibrations in the response of a flexible cantilever beam to transverse harmonic base excitations around its flexural mode frequencies. In the experimental setup, instead of manual control of the signal excitation frequency and amplitude, a closed-loop vibration system is used to keep the excitation amplitude constant during the frequency sweep and to increase confidence in the experimental results. The experimental results show the presence of the third mode in the response when varying the excitation frequency around the fourth mode. The frequency-response curves, response spectrum and Poincaré plots were used for characterization of nonlinear dynamic behaviour of the beam.
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Authors and Affiliations

Everaldo De Barros
Carlos D’andrade Souto
Mauro Hugo Mathias

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