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  • 1
    Online-Ressource
    Online-Ressource
    Institute of Advanced Engineering and Science ; 2023
    In:  Bulletin of Electrical Engineering and Informatics Vol. 12, No. 6 ( 2023-12-01)
    In: Bulletin of Electrical Engineering and Informatics, Institute of Advanced Engineering and Science, Vol. 12, No. 6 ( 2023-12-01)
    Kurzfassung: In millimeter wave communication systems, the construction of a path loss model that is close to empirical one plays an important role in planning coverage, system capacity, and link budgets. In this paper, we propose a novel approach applied unsupervised machine learning for propagation pathloss estimation in millimeter wave communication systems based on the iterative procedure of cooperative and iterative evaluation exchange (Co-IEE) algorithm. The propagation path loss models of the time city–an urban area in the center of Hanoi, Vietnam in both line-of-sight (LOS) and non line-of-sight (NLOS) are estimated and calculated using the proposed approach and then they are compared to the minimum mean square error (MMSE). The estimated results of the proposed model show the approximation with the optimum one returned by MMSE method. Moreover, the proposed model of estimating path loss can solve the problem of sensitivity with outliers existing in MMSE and give more choices for path loss exponents.
    Materialart: Online-Ressource
    ISSN: 2302-9285 , 2089-3191
    URL: Issue
    Sprache: Unbekannt
    Verlag: Institute of Advanced Engineering and Science
    Publikationsdatum: 2023
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    Online-Ressource
    Online-Ressource
    European Alliance for Innovation n.o. ; 2023
    In:  EAI Endorsed Transactions on Industrial Networks and Intelligent Systems Vol. 10, No. 3 ( 2023-09-06), p. e2-
    In: EAI Endorsed Transactions on Industrial Networks and Intelligent Systems, European Alliance for Innovation n.o., Vol. 10, No. 3 ( 2023-09-06), p. e2-
    Kurzfassung: Exploring the ocean has always been one of the foremost challenges for humankind, and fish classification is one of the crucial tasks in this endeavor. Manual fish classification methods, although accurate, consume significant time, money, and effort, while computer-based methods such as image processing and traditional machine learning often fall short of achieving high accuracy. Recently, deep convolutional neural networks have demonstrated their capability to ensure both time efficiency and accuracy in this task. However, deep convolutional networks typically have a large number of parameters, requiring substantial training time, and the convolutional operations lack attentional mechanisms. Therefore, in this paper, we propose the AttentionConvMixer neural network with Priority Channel Attention (PCA) and Priority Spatial Attention (PSA). The proposed approach exhibits good performance across all three fish classification datasets without introducing any additional parameters, thus demonstrating the effectiveness of our proposed method.
    Materialart: Online-Ressource
    ISSN: 2410-0218
    Sprache: Unbekannt
    Verlag: European Alliance for Innovation n.o.
    Publikationsdatum: 2023
    ZDB Id: 3003127-8
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    Online-Ressource
    Online-Ressource
    European Alliance for Innovation n.o. ; 2023
    In:  EAI Endorsed Transactions on Industrial Networks and Intelligent Systems Vol. 10, No. 1 ( 2023-04-20), p. e4-
    In: EAI Endorsed Transactions on Industrial Networks and Intelligent Systems, European Alliance for Innovation n.o., Vol. 10, No. 1 ( 2023-04-20), p. e4-
    Kurzfassung: Accurate measurements and statistics of fish data are important for sustainable development of aqua-enviroment and marine fisheries. For data measurements and statistics, automatic segmentation of fish is one of key tasks. The fish segmentation however is a challenging task due to arterfacts in underwater images. In this study, we introduce a deep-learning approach, namely FCN-WRN-WASP for automatic fish segmentation from the underwater images. In particular, we introduce a computational-efficient variation called Waterfall Atrous Spatial Pooling (WASP) module into a Fully convolutional network with Wide ResNet baseline. We also proposed a loss function inspired from active contour approach that can exploit the local intensity information from the input image. The approach has been validated on the DeepFish data and the SIUM data set. The results are promissing for fish segmentation, with higher Intersection over Union (IoU) scores compared to state of the arts. The evaluation results showed that the incorporation of the image based active contour loss helps increase the segmentation performance. In addition, the use of the WASP in the architecture is effective especially for forground fish segmentation.
    Materialart: Online-Ressource
    ISSN: 2410-0218
    Sprache: Unbekannt
    Verlag: European Alliance for Innovation n.o.
    Publikationsdatum: 2023
    ZDB Id: 3003127-8
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    Online-Ressource
    Online-Ressource
    Hindawi Limited ; 2012
    In:  Abstract and Applied Analysis Vol. 2012 ( 2012), p. 1-15
    In: Abstract and Applied Analysis, Hindawi Limited, Vol. 2012 ( 2012), p. 1-15
    Kurzfassung: We present and investigate a method of chaotic pulse-time modulation (PTM) named chaotic pulse-width-position modulation (CPWPM) which is the combination of pulse-position-modulation (PPM) and pulse-width modulation (PWM) with the inclusion of chaos technique for digital communications. CPWPM signal is in the pulse train format, in which binary information is modulated onto chaotically-varied intervals of position and width of pulses, and therefore two bits are encoded on a single pulse. The operation of the method is described and the theoretical evaluation of bit-error rate (BER) performance in the presence of additive white Gaussian noise (AWGN) is provided. In addition, the chaotic behavior with tent map and its effect on average parameters of the system are investigated. Theoretical estimation and numerical simulation of a CPWPM system with specific parameters are carried out in order to verify the performance of the proposed method.
    Materialart: Online-Ressource
    ISSN: 1085-3375 , 1687-0409
    Sprache: Englisch
    Verlag: Hindawi Limited
    Publikationsdatum: 2012
    ZDB Id: 2064801-7
    SSG: 17,1
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Online-Ressource
    Online-Ressource
    Emerald ; 2013
    In:  COMPEL - The international journal for computation and mathematics in electrical and electronic engineering Vol. 32, No. 3 ( 2013-05-03), p. 776-793
    In: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Emerald, Vol. 32, No. 3 ( 2013-05-03), p. 776-793
    Kurzfassung: This paper presents and investigates a method named M×N‐ary chaotic pulse‐width‐position modulation (CPWPM) which is based on the combination of M‐ary chaotic pulse‐position modulation (CPPM) and N‐ary chaotic pulse‐width modulation (CPWM) in order to provide a better performance in noise‐affected environments as well as improve significantly bit rate. Design/methodology/approach Analysis of schemes for modulator and demodulator are presented in detail through describing the schemes of the individual methods and their combination. Theoretical evaluation of bit‐error rate (BER) performance in presence of additive white Gaussian noise (AWGN) is provided. Chaotic behavior with tent map in variation of modulation parameters is also investigated. In order to verify the theoretical analyses, numerical simulations are carried out and their results are reported. Findings Both evaluation and simulation results show that when the number of symbols increases, the bit rate is improved significantly but the BER performance is just slightly worse. This makes M×N‐ary CPWPM become an effective method for chaos‐based digital communication. Originality/value Although CPPM, CPWM and M‐ary modulation methods have been described in the literature separately, their combination is presented and investigated for the first time in this paper.
    Materialart: Online-Ressource
    ISSN: 0332-1649
    Sprache: Englisch
    Verlag: Emerald
    Publikationsdatum: 2013
    ZDB Id: 1501321-2
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    Online-Ressource
    Online-Ressource
    Cambridge University Press (CUP) ; 2019
    In:  International Journal of Microwave and Wireless Technologies Vol. 11, No. 08 ( 2019-10), p. 851-862
    In: International Journal of Microwave and Wireless Technologies, Cambridge University Press (CUP), Vol. 11, No. 08 ( 2019-10), p. 851-862
    Kurzfassung: In this paper, a multiple input multiple output antenna which operates at 5.8 GHz for wireless local area network applications is proposed. The proposed antenna is composed of two sets of four elements antenna array (2 × 2) on the top and a novel metamaterial structure on the ground plane. Here, the ground plane, which includes a lattice of 2 × 5 unit cells of metamaterial structure, is utilized in order to improve parameters of the antenna. Thanks to the proposed metamaterial structure, not only gain and bandwidth of antenna are enhanced, but also mutual coupling is reduced. The final design, with an overall size of 137 × 77 × 3.048 mm 3 , resulted in a | S 11| & lt;−10 dB bandwidth of 1.78 GHz and a peak gain of 9.2 dBi. In addition, the isolation is higher than 18 dB although the close separation from edge to edge of the two antennas is only 2 mm and radiation efficiency of 73% at the operating frequency band. All is simulated based on CST Studio software and the simulated S-parameter results of the antenna are in good agreement with measurement results.
    Materialart: Online-Ressource
    ISSN: 1759-0787 , 1759-0795
    Sprache: Englisch
    Verlag: Cambridge University Press (CUP)
    Publikationsdatum: 2019
    ZDB Id: 2497484-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    Online-Ressource
    Online-Ressource
    Vietnam National University Journal of Science ; 2017
    In:  VNU Journal of Science: Computer Science and Communication Engineering ( 2017-10-02)
    In: VNU Journal of Science: Computer Science and Communication Engineering, Vietnam National University Journal of Science, ( 2017-10-02)
    Kurzfassung: In this paper, we present a method for determining complex permittivity of materials using two different thicknesses of the sample placed in free space. The proposed method is based on the use of transmission having the same geometry with different thicknesses with the aim to determine the complex propagation constant (γ). The reflection and transmission coefficients (S11 and S21) of material samples are determined using a free-space measurement system. The system consists of transmit and receive horn antennas operating at X-band. The complex permittivity of materials is calculated from the values of γ, in turns received from S11 and S21. The proposed method is tested with different material samples in the frequency range of 8.0 – 12.0 GHz. The results show that the dielectric loss tangent of low-loss material samples, the more accuracy of complex permittivity. However, the complex permittivity is slightly effected by the dielectric loss tangent of high-loss of material samples.
    Materialart: Online-Ressource
    ISSN: 2588-1086
    Sprache: Unbekannt
    Verlag: Vietnam National University Journal of Science
    Publikationsdatum: 2017
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    Online-Ressource
    Online-Ressource
    Hindawi Limited ; 2013
    In:  Abstract and Applied Analysis Vol. 2013 ( 2013), p. 1-11
    In: Abstract and Applied Analysis, Hindawi Limited, Vol. 2013 ( 2013), p. 1-11
    Kurzfassung: This paper proposes a chaos-based secure direct-sequence/spread-spectrum (DS/SS) communication system which is based on a novel combination of the conventional DS/SS and chaos techniques. In the proposed system, bit duration is varied according to a chaotic behavior but is always equal to a multiple of the fixed chip duration in the communication process. Data bits with variable duration are spectrum-spread by multiplying directly with a pseudonoise (PN) sequence and then modulated onto a sinusoidal carrier by means of binary phase-shift keying (BPSK). To recover exactly the data bits, the receiver needs an identical regeneration of not only the PN sequence but also the chaotic behavior, and hence data security is improved significantly. Structure and operation of the proposed system are analyzed in detail. Theoretical evaluation of bit-error rate (BER) performance in presence of additive white Gaussian noise (AWGN) is provided. Parameter choice for different cases of simulation is also considered. Simulation and theoretical results are shown to verify the reliability and feasibility of the proposed system. Security of the proposed system is also discussed.
    Materialart: Online-Ressource
    ISSN: 1085-3375 , 1687-0409
    Sprache: Englisch
    Verlag: Hindawi Limited
    Publikationsdatum: 2013
    ZDB Id: 2064801-7
    SSG: 17,1
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 9
    Online-Ressource
    Online-Ressource
    Springer Science and Business Media LLC ; 2018
    In:  Mobile Networks and Applications Vol. 23, No. 6 ( 2018-12), p. 1563-1571
    In: Mobile Networks and Applications, Springer Science and Business Media LLC, Vol. 23, No. 6 ( 2018-12), p. 1563-1571
    Materialart: Online-Ressource
    ISSN: 1383-469X , 1572-8153
    Sprache: Englisch
    Verlag: Springer Science and Business Media LLC
    Publikationsdatum: 2018
    ZDB Id: 1342049-5
    ZDB Id: 2000637-8
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 10
    Online-Ressource
    Online-Ressource
    Wiley ; 2008
    In:  Microwave and Optical Technology Letters Vol. 50, No. 10 ( 2008-10), p. 2604-2608
    In: Microwave and Optical Technology Letters, Wiley, Vol. 50, No. 10 ( 2008-10), p. 2604-2608
    Materialart: Online-Ressource
    ISSN: 0895-2477 , 1098-2760
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2008
    ZDB Id: 2000574-X
    Standort Signatur Einschränkungen Verfügbarkeit
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