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Number of results: 7
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Abstract

The wavelet transform has been successfully used in the area of power quality analysis. There are many published papers with methods for power quality disturbance classification or harmonics measurement, which use wavelet transform. However, the properties of the wavelet transform can drastically vary from the choice of the wavelet. In this paper we analyze the influence of the choice of the wavelet to the accuracy of the power quality classification method and to high frequency harmonics measurements. Additionally to the well known wavelet filters we introduce near perfect reconstruction filter banks. The simulation results indicate that these filter banks are a good choice for classification of power quality disturbances, especially in the presence of noise and for high frequency harmonics measurements

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Authors and Affiliations

Dimitar Taskovski
Ljubica Koleva
Aleksandar Milchevski
Vladimir Dimcev
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Abstract

An attempt is made in the current research to obtain the fundamental buckling torque and the associated buckled shape of an annular plate. The plate is subjected to a torque on its outer edge. An isotropic homogeneous plate is considered. The governing equations of the plate in polar coordinates are established with the aid of the Mindlin plate theory. Deformations and stresses of the plate prior to buckling are determined using the axisymmetric flatness conditions. Small perturbations are then applied to construct the linearised stability equations which govern the onset of buckling. To solve the highly coupled equations in terms of displacements and rotations, periodic auxiliary functions and the generalised differential quadrature method are applied. The coupled linear algebraic equations are a set of homogeneous equations dealing with the buckling state of the plate subjected to a unique torque. Benchmark results are given in tabular presentations for combinations of free, simply-supported, and clamped types of boundary conditions. It is shown that the critical buckling torque and its associated shape highly depend upon the combination of boundary conditions, radius ratio, and the thickness ratio.

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Bibliography

[1] W.R. Dean. The elastic stability of an annular plate. Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 106(737):268–284, 1924. doi: 10.1098/rspa.1924.0068.
[2] J. Tani and T. Nakamura. Dynamic stability of annular plates under pulsating torsion. Journal of Applied Mechanics, 47(3):595–600, 1980. doi: 10.1115/1.3153739.
[3] J. Tani. Dynamic stability of orthotropic annular plates under pulsating torsion. The Journal of the Acoustical Society of America, 69(6):1688–1694, 1981. doi: 10.1121/1.385948.
[4] D. Durban and Y. Stavsky. Elastic buckling of polar-orthotropic annular plates in shear. International Journal of Solids and Structures, 18(1):51–58, 1982. doi: 10.1016/0020-7683(82)90015-4.
[5] T. Irie, G. Yamada, and M. Tsujino. Vibration and stability of a variable thickness annular plate subjected to a torque. Journal of Sound and Vibration, 85(2):277–285, 1982. doi: 10.1016/0022-460X(82)90522-3.
[6] T. Irie, G. Yamada, and M. Tsujino. Buckling loads of annular plates subjected to a torque. Journal of Sound and Vibration, 86(1):145–146, 1983. doi: 10.1016/0022-460X(83)90951-3.
[7] J. Zajączkowski. Stability of transverse vibration of a circular plate subjected to a periodically varying torque. Journal of Sound and Vibration, 89(2):273–286, 1983. doi: 10.1016/0022-460X(83)90394-2.
[8] H. Doki and J. Tani. Buckling of polar orthotropic annular plates under internal radial load and torsion. International Journal of Mechanical Sciences, 27:429–437, 1985. doi: 10.1016/0020-7403(85)90033-5.
[9] M. Hamada and T. Harima. In-plane torsional buckling of an annular plate. Bulletin of JSME, 29(250):1089–1095, 1986. doi: 10.1299/jsme1958.29.1089.
[10] E. Ore and D. Durban. Elastoplastic buckling of annular plates in pure shear. Journal of Applied Mechanics, 56(3):644–651, 1989. doi: 10.1115/1.3176141.
[11] Chang-Jun Cheng and Xiao-an Lui. Buckling and post-buckling of annular plates in shearing, Part I: Buckling. Computer Methods in Applied Mechanics and Engineering, 92(2):157–172, 1991. doi: 10.1016/0045-7825(91)90237-Z.
[12] Chang-Jun Cheng and Xiao-an Lui. Buckling and post-buckling of annular plates in shearing, Part II: Post-buckling. Computer Methods in Applied Mechanics and Engineering, 92(2):173–191, 1991. doi: 10.1016/0045-7825(91)90238-2.
[13] P. Singhatanadgid and V. Ungbhakorn. Scaling laws for buckling of polar orthotropic annular plates subjected to compressive and torsional loading. Thin-Walled Structures, 43(7):1115–1129, 2005. doi: 10.1016/j.tws.2004.11.004.
[14] T.X. Wu. Analytical study on torsional vibration of circular and annular plate. Journal of Mechanical Engineering Science, 220(4):393–401, 2006. doi: 10.1243/09544062JMES167.
[15] R. Maretic, V. Glavardanov, and D. Radomirovic. Asymmetric vibrations and stability of a rotating annular plate loaded by a torque. Meccanica, 42(6):537–546, 2007. doi: 10.1007/s11012-007-9080-8.
[16] S.E. Ghiasian, Y. Kiani, M. Sadighi, and M.R. Eslami. Thermal buckling of shear deformable temperature dependent circular annular FGM plates. International Journal of Mechanical Sciences, 81:137–148, 2014. doi: 10.1016/j.ijmecsci.2014.02.007.
[17] H. Bagheri, Y. Kiani, and M.R. Eslami. Asymmetric thermal buckling of temperature dependent annular FGM plates on a partial elastic foundation. Computers & Mathematics with Applications, 75(5):1566–1581, 2018. doi: 10.1016/j.camwa.2017.11.021.
[18] H. Bagheri, Y. Kiani, and M.R. Eslami. Asymmetric compressive stability of rotating annular plates. European Journal of Computational Mechanics, 2019. doi: 10.1080/17797179.2018.1560989.
[19] J.N. Reddy. Mechanics of Laminated Composite Plates and Shells, Theory and Application. CRC Press, 2nd Edition, 2003.
[20] H. Bagheri, Y. Kiani, and M.R. Eslami. Asymmetric thermal buckling of annular plates on a partial elastic foundation. Journal of Thermal Stresses, 40(8):1015–1029, 2017. doi: 10.1080/01495739.2016.1265474.
[21] H. Bagheri, Y. Kiani, and M.R. Eslami. Asymmetric thermo-inertial buckling of annular plates. Acta Mechanica, 228(4):1493–1509, 2017. doi: 10.1007/s00707-016-1772-5.
[22] D.O. Brush and B.O. Almroth. Buckling of Bars, Plates, and Shells. McGraw-Hill, New York, 1975.
[23] M.R. Eslami. Thermo-Mechanical Buckling of Composite Plates and Shells. Amirkabir University Press, Tehran, 2010.
[24] Y. Kiani Y and M.R. Eslami. An exact solution for thermal buckling of annular FGM plates on an elastic medium. Composites Part B: Engineering, 45(1):101–110, 2013. doi: 10.1016/j.compositesb.2012.09.034.
[25] F. Tornabene, N. Fantuzzi F. Ubertini, and E. Viola. Strong formulation finite element method based on differential quadrature: a survey. Applied Mechanics Reviews, 67(2):020801-020801-55, 2015. doi: 10.1115/1.4028859.
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Authors and Affiliations

Hamed Bagheri
1
Yaser Kiani
2
Mohammad Reza Eslami
1

  1. Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
  2. Faculty of Engineering, Shahrekord University, Shahrekord, Iran.
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Abstract

The performance of the multi-input multi-output (MIMO) systems can be improved by spatial modulation. By using spatial modulation, the transmitter can select the best transmit antenna based on the channel variations using channel state information (CSI). Also, the modulation helps the transmitter to select the best modulation level such that the system has the best performance in all situations. Hence, in this paper, two issues are considered including spatial modulation and information modulation selection. For the spatial modulation, an optimal solution for obtaining the probability of selecting antenna is calculated and then Huffman coding is used such that the transmitter can select the best transmit antenna to maximize the channel capacity. For the information modulation, a multi quadrature amplitude modulation (MQAM) strategy is used. In this modulation, the modulation size is changed based on the channel state variations; therefore, the best modu- lation index is used for transmitting data in all channel situations. In simulation results, the optimal method is compared with Huffman mapping. In addition, the effect of modulation on channel capacity and a bit error rate (BER) is shown.

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Authors and Affiliations

Bahar Ghaderi
Naser Parhizgar
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Abstract

An application specific integrated design using Quadrature Linear Discriminant Analysis is proposed for automatic detection of normal and epilepsy seizure signals from EEG recordings in epilepsy patients. Five statistical parameters are extracted to form the feature vector for training of the classifier. The statistical parameters are Standardised Moment, Co-efficient of Variance, Range, Root Mean Square Value and Energy. The Intellectual Property Core performs the process of filtering, segmentation, extraction of statistical features and classification of epilepsy seizure and normal signals. The design is implemented in Zynq 7000 Zc706 SoC with average accuracy of 99%, Specificity of 100%, F1 score of 0.99, Sensitivity of 98% and Precision of 100 % with error rate of 0.0013/hr., which is approximately zero false detection.

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Authors and Affiliations

S. Syed Rafiammal
D. Najumnissa
G. Anuradha
S. Kaja Mohideen
P.K. Jawahar
Syed Abdul Mutalib
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Abstract

In this paper, the designing and simulation of 400 Gbps polarisation division multiplexing-quadrature amplitude modulation-orthogonal frequency division multiplexing (PDM-4QAM-OFDM)-based inter-satellite optical wireless communication (IsOWC)/mechatronic telecommunication system for improving the link information carrying capacity was carried out. With quadrature amplitude modulation (QAM) encoding, the performance of the executed system has been addressed using metrics such as signal to noise ratio (SNR) and total received power (RP). The performance with suggested system has been examined in relation to the effects of various factors such as operating wavelength, transmission power, and receiving pointing error angle. Moreover, a better identification method for improving connection reach between mechatronic devices/satellites has been revealed in this study. A performance comparison of the proposed system with other implemented approaches has been made in the final step
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Authors and Affiliations

Shivmanmeet Singh
1 2
Narwant Singh Grewal
2
Baljeet Kaur
2

  1. I. K. Gujral Punjab Technical University, Jalandhar – Kapurthala Highway, Kapurthala, 144603, Punjab, India
  2. Department of Electronics and Communication Engineering, Guru Nanak Dev Engineering College, Ludhiana, 141006, Punjab, India

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