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Abstract

Agricultural drainage has become a priority in agriculture and the economic development of the state. Algeria has launched several agro-economic projects pertaining to natural resources and human potential for development in agricultur-al areas. Our aim is to model the morphological evolution of open drainage channels, under the influence of sedimentary transport processes. The application of the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) software is to examine two-phase mathematical models. In our case it is the flow and the sedimentary charge along a trapezoidal earth channel of a wetland north east of Algeria. The results of these models were validated by actual data obtained during the observation period from 2017 to 2018, for various rainy events. The solid transport and sedimentation velocity equa-tions of Engelund and Hansen and Van Rijn respectively used by this model, give Nash performance criteria equal to 0.95 and determination coefficient R2 equal to 0.91. On the other hand, the laying of a coarse gravel layer of median diameter of the grains d50% = 60 mm on the bottom of the channels reduces the rate of sedimentation by about 32% over an 11-year pe-riod. This satisfying objective study of the modelling allows to obtain an approach to the renovation and a plan for new design of drainage systems, that participates to the sustainable development in the agricultural field.

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Authors and Affiliations

Foued Sennaoui
Tamara Benabdesselam
Abdallah Saihia
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Abstract

Identification of coefficients determining flow resistance, in particular Manning’s roughness coefficients, is one of the possible inverse problems of mathematical modeling of flow distribution in looped river networks. The paper presents the solution of this problem for the lower Oder River network consisting of 78 branches connected by 62 nodes. Using results of six sets of flow measurements at particular network branches it was demonstrated that the application of iterative algorithm for roughness coefficients identification on the basis of the sensitivity-equation method leads to the explicit solution for all network branches, independent from initial values of identified coefficients.

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Authors and Affiliations

Jacek Kurnatowski
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Abstract

This paper presents the results of an experimental study and
mathematical modeling of the effect of dynamic instabilities on the condensation phase transformation of the refrigerants homogeneous R134a and its replacement in the form of isomers R1234yf and R1234ze and R404A or R507 and R448A in pipe mini-channels. In the case of homogeneous chlorofluorocarbons (CFCs), it is the 1234 isomers that are envisioned as substitutes for the withdrawn ones with high ozone depletion potential and global warming potential. For zeotropic and azeotropic mixtures, for example, these are R507 or R448A. The paper presents a dimensional analysis procedure based on the Buckingham Π theorem to develop a regression velocity model of pressure dynamic instabilities. The experimental part of the work was carried out with the use of tubular mini-channels with internal diameter 1.40–3.3 mm.
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Authors and Affiliations

Waldemar Kuczyński
1

  1. Koszalin University of Technology, Faculty of Mechanical Engineering, Department of Power Engineering, Racławicka 15-17, 75-625 Koszalin, Poland
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Abstract

Due to the multifold growth in demands of multimedia services and mobile data, the request for increased channel capacity in mobile and wireless communication has been quickly increasing. Developing a wireless system with more spectral efficiency under varying channel condition is a key challenge to provide more bit rates with limited spectrum. Multiple Input Multiple Output (MIMO) system with Orthogonal Frequency Division Multiplexing (OFDM) gives higher gain by using the direct and the reflected signals, thus facilitating the transmission at high data rate. An integration of Spatial Modulation (SM) with OFDM (SM OFDM) is a newly evolved transmission technique and has been suggested as a replacement for MIMO -OFDM transmission. In practical scenarios, channel estimation is significant for detecting transmitted data coherently. This paper proposes pilot based, Minimum Mean Square Error (MMSE) channel estimation for the SM OFDM communication system. We have focused on analyzing Symbol Error Rate (SER) and Mean Square error (MSE) under Rayleigh channel employing International Telecommunication Union (ITU) specified Vehicular model of Pilot based MMSE channel estimator using windowed Discrete Fourier Transform (DFT) and MMSE weighting function. Simulation output shows that proposed estimator’s SER performance lies close to that of the MMSE optimal estimator in minimizing aliasing error and suppressing channel noise by using frequency domain data windowing and time domain weighting function. Usage of the Hanning window eliminates error floor and has a compact side lobe level compared to Hamming window and Rectangular window. Hanning window has a larger MSE at low Signal to Noise Ratio (SNR) values and decreases with high SNR values. It is concluded that data windowing technique can minimize the side lobe level and accordingly minimize channel estimation error when interpolation is done. MMSE weighting suppresses channel noise and improves estimation performance. Since Inverse Discrete Fourier Transform (IDFT)/DFT transforms can be implemented with fast algorithms Inverse Fast Fourier Transform( IFFT)/Fast Fourier Transform (FFT) computational complexity can be remarkably reduced.
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Bibliography

[1] A. Mohammadi, F.M. Ghannouchi, “Single RF front-end MIMO transceivers,” in RF transceiver design for MIMO wireless communications, Springer, Berlin, Heidelberg, pp. 265-288, 2012.
[2] R. Mesleh, H. Haas, C.W. Ahn, S. Yun, “Spatial modulation-a new low complexity spectral efficiency enhancing technique,” in 2006 First International Conference on Communications and Networking in China IEEE, pp. 1-5, Oct 25, 2006.
[3] M. Wen, B. Zheng, K.J. Kim, M. Di Renzo, T.A. Tsiftsis, K.C. Chen, N. Al-Dhahir, “A survey on spatial modulation in emerging wireless systems: Research progresses and applications,” IEEE Journal on Selected Areas in Communications, 37(9): 1949-72, Jul 17, 2019.
[4] H. Doğan, E. Panayırcı, H.V. Poor, “Low-complexity joint data detection and channel equalisation for highly mobile orthogonal frequency division multiplexing systems,” IET communications, 4(8): 1000-11, May 21, 2010.
[5] H. Haas, S. Sinanovic, C.W. Ahn, S. Yun, “Spatial modulation,” IEEE Trans. Veh. Technol, 57(4): 2228-41, Jul 2008.
[6] M. Biguesh, A.B. Gershman, “Training-based MIMO channel estimation: a study of estimator tradeoffs and optimal training signals,” IEEE transactions on signal processing, 54(3):884-93, Feb 21, 2006.
[7] M. Yalcin, A. Akan, H. Doğan, “Low-complexity channel estimation for OFDM systems in high-mobility fading channels,” Turkish Journal of Electrical Engineering & Computer Sciences, 25;20(4): 583-92, Apr. 2012.
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[13] Y. Acar, H. Doğan, E. Panayirci, “Pilot symbol aided channel estimation for spatial modulation-OFDM systems and its performance analysis with different types of interpolations,” Wireless Personal Communications, 94(3): 1387-404, Jun 2017.
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[26] M. Patzold, “Mobile fading channels,” Hoboken: Wiley, 2003
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Authors and Affiliations

Anetha Mary Soman
1
R. Nakkeeran
1
Mathew John Shinu
2

  1. Department of Electronics Engineering, School of Engineering and Technology, Pondicherry Central University, Pondicherry, India
  2. Department of Computer Science, St.ThomasCollege of Engineering & Technology, Kannur, Kerala, India
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Abstract

The current paper is a review of the results attained in the past and current anatomical studies, aimed at understanding the variability and function of the diploic venous system of the human skull. The diploic veins can serve as transit for infections from the scalp to the structures contained within the cranial cavity via the emissary veins, due to their interconnections with the pericranial veins, meningeal veins and dural sinuses. Thereby this clinical aspect has also been discussed.
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Authors and Affiliations

Janusz Skrzat
1
Michał Zarzecki
1

  1. Department of Anatomy, Jagiellonian University Medical College, Kraków, Poland
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Abstract

The article is the result of a project aimed at developing and implementing a design of composite accessories for support in excavations located in underground hard coal mines. The research team verified the possibility of using elements made of prefabricated composite structural profile as an alternative to steel and reinforced concrete lining elements used to improve support’s stability and protect against rockfall.
This paper includes a research experiment on the possibilities of using a composite C-profile element as lining made in the pultrusion technology with a longitudinal position of the roving. The prefabricated structural profiles were adapted to the function by designing seatings for fitting the flanges for arch support’s V-profiles. Prototypes of these elements were subjected to bench tests in compliance with the guidelines for testing mesh linings. In addition, computer simulations using the finite element method were carried out.
The values obtained during the tests were compared with the requirements for lightweight mesh and included the Polish standard PN-G-15050 and reinforced A-type concrete lining defined in the standard ­PN-G-06021. The team determined the areas where material strength exceeded and the structure was damaged. Despite the limited quantity of laboratory tests and lack of field tests in actual mining conditions, it was possible to address the argument of the research and determine whether it is possible to use C-profile made in the pultrusion technology as a lining element.
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Bibliography

[1] PN-G-15050:2018-01 Obudowa wyrobisk górniczych. Siatki okładzinowe zgrzewane.
[2] PN-G-06021:1997 Obudowa górniczych wyrobisk korytarzowych. Okładziny żelbetowe.
[3] M. Rotkegel. Wpływ sposobu montażu siatek okładzinowych na ich pracę. Przegląd Górniczy 70 (3), 79-85 (2014).
[4] J. Olszewski, Leksykon górniczy: praca zbiorowa. Katowice: Wydawnictwo Śląsk (1989).
[5] L . Nickels, The future of pultrusion. Reinf. Plast. 63 (3), 132-135 (2019). DOI: https://doi.org/10.1016/j.repl.2019.01.003
[6] G .G. Litwinskij, G.I. Gajko, N.I. Kyldyrkajew, Stalnyje ramnyje kriepi gornych wyrabotok. Kijew: Technika (1999).
[7] M. Grodzicki, M. Rotkegel, The concept of modification and analysis of the strength of steel roadway supports for coal mines in the Soma Basin in Turkey. Studia Geotechnica et Mechanica 40 (1), 38-45 (2018). DOI: https://doi.org/10.2478/sgem-2018-0006
[8] G .I. Gayko, M. Rotkegel, Issliedowanija niesuszcziej sposobnosti arocznoj kriepi pri razlicznych wariantach nagrużienia. Ugoł Ukrainy 2, 45-47 (2003).
[9] P. Horyl, R. Snuparek, P. Marsalek, K. Pacześniowski, Simulation of laboratory tests of steel arch support. Arch. Min. Sci. 62 (1), 63-176 (2017). DOI: http://doi.org/10.1515/amsc-2017-0012455
[10] H. Filcek, J. Walaszczyk, A. Tajduś, 1994. Metody komputerowe w geomechanice górniczej. Śląskie Wydawnictwo Techniczne (1994).
[11] R .D. Cook, D.S. Malkus, M.E. Plesha, R.J. Witt, Finite Element Modeling for Stress Analysis. John Wiley & Sons, Inc. (2002).
[12] CO SMOS/M User’s Guide, Los Angeles, Structural Research & Analysis Corp. (1999).
[13] E. Rusiński, Metoda elementów skończonych. System COSMOS/M. Wydawnictwo Komunikacji i Łączności (1994).
[14] A. Pytlik. Tests of steel arch and rock bolt support resistance to static and dynamic loading induced by suspended monorail transportation. Studia Geotechnica et Mechanica 41 (2), 81-92 (2019). DOI: https://doi.org/10.2478/sgem-2019-0009
[15] A. Pytlik. Comparative bench testing of steel arch support systems with and without rock bolt reinforcements. Arch. Min. Sci. 64 (4), 747-764 (2019). DOI: http://doi.org/10.24425/ams.2019.131064
[16] PN-G-15022:2018-11 Odrzwia podatne z kształtowników korytkowych – Wymagania wytrzymałościowe i badania.
[17] PN-G-15024:2017-10 Obudowa wyrobisk górniczych – Rozpory stalowe dwustronnego działania.
[18] PN-G-15026:2017-04 Obudowa wyrobisk górniczych – Strzemiona oraz złącza odrzwi z kształtowników korytkowych – Badania wytrzymałościowe.
[19] PN-G-14050:1998 Betonity fundamentowe do obudowy odrzwiami z łuków korytkowych wyrobisk górniczych poziomych i mało nachylonych – Wymagania i badania.
[20] PN-G-15092:1999 Kotwie górnicze – Badania.
[21] PN-G-15533:1997 Górnicza obudowa indywidualna – Stojaki cierne – Wymagania i badania.
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Authors and Affiliations

Marek Rotkegel
1
ORCID: ORCID
Jerzy Korol
1
ORCID: ORCID
Dagmara Sobczak
1
ORCID: ORCID

  1. Central Mining Institute, Plac Gwarków 1, 40-166, Katowice, Poland
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Abstract

In November 1994 a first inventory of Tanaidacea from the Beagle Channel and at some stations of the Atlantic continental shelfwas obtained using epibenthic sledge samples. In total, 2175 specimens from 27 species of eight families of Tanaidomorpha and two families of Apseudomorpha were collected. Two species, Allotanais hirstutus (Beddard, 1886) and Apseudes heroae Sieg, 1986, strongly dominated this area. Generally low diversity and abundances were recorded for the western area of the Beagle Channel, while substantially higher values were reported at the eastern entrance on the Atlantic side of the Beagle Channel. Abundances slightly varied with depths, but not significantly.

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Authors and Affiliations

Anja Schmidt
Angelika Brandt
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Abstract

104 specimens of notothenioid fishes of five species (Patagonotothen longipes, P. tessellata, Champsocephalus esox, Cottoperca trigloides and Patagonotothen brevicauda) caught at two sites in the Beagle Channel (Magellanic sub-region, sub-Antarctica) were examined for the presence of thorny-headed worms (Acanthocephala). Representatives of three fish species, Patagonotothen longipes, P. tessellata, and Champsocephalus esox, were infected. Fishes caught at the eastern mouth of the channel were infected with 180 echinorhynchids representing three species, Aspersentis johni (the most numerous species), Heterosentis heteracanthus, and Hypoechinorhynchus magellanicus, and only 12 cystacanths of four polymorphids, Andracantha baylisi, Corynosoma sp., Corynosoma beaglense, and Corynosoma evae. Patagonotothen longipes was the most highly infected in the eastern mouth of the channel (prevalence 85%, maximum intensity 26). Aspersentis johni was the dominant parasite species in this host (prevalence 85%, mean abundance 4.00, maximum intensity 18) and H. heteracanthus was the sub-dominant one (prevalence 50%, mean abundance 2.60, maximum intensity 25). The infections of C. esox were the most diverse (six parasite species - three echinorhynchids and three polymorphids). Fish caught near the city of Ushuaia were infected only with six cystacanths of C. evae (intensity one). Taking into account the whole sample, C. evae was the most abundant polymorphid, represented by 10 of 18 specimens found. Three species, H. heteracanthus, A. baylisi and C. evae, have been previously reported from the low western Antarctic (H. heteracanthus also from the Kerguelen sub-region of sub-Antarctic), remaining four species seem to be endemics of the Magellanic sub-region of sub-Antarctic.

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Authors and Affiliations

Zdzisław Laskowski
Krzysztof Zdzitowiecki
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Abstract

In this paper, we present the methods to detect the channel delay profile and the Doppler spectrum of shallow underwater acoustic channels (SUAC). In our channel sounding methods, a short impulse in form of a sinusoid function is successively sent out from the transmitter to estimated the channel impulse response (CIR). A bandpass filter is applied to eliminate the interference from out-of-band (OOB). A threshould is utilized to obtain the maximum time delay of the CIR. Multipath components of the SUAC are specified by correlating the received signals with the transmitted sounding pulse with its shifted phases from 0 to 2π. We show the measured channel parameters, which have been carried out in some lakes in Hanoi. The measured results illustrate that the channel is frequency selective for a narrow band transmission. The Doppler spectrum can be obtained by taking the Fourier transform of the time correlation of the measured channel transfer function. We have shown that, the theoretical maximum Doppler frequency fits well to that one obtained from measurement results.

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Authors and Affiliations

Van Duc Nguyen
Tien Hoa Nguyen
Hoa Xuan Thi Ho
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Abstract

One of the main causes of damage to weirs regulating the flow of water in canals is local erosion of the bottom and banks. This is mainly due to the excessive kinetic energy of the stream flow and the uneven volumetric distribution of the water flow rate at the end of the strengthening. Due to this, 35–40% of hydraulic structures fail prematurely. The aim of the research was to determine the parameters of the spatial hydraulic jump arising behind the hydrotechnical structure and the rapid expansion of the cross-section. The research showed that the hydraulic jump with a curved cylinder in the plan is a spatial form and not only dissipates the energy of the stream, but also acts as a diffuser. With the stream expansion angle values in the range of 7–10°, a highly turbulent flow remains, which still has high kinetic energy at a distance from the end of the structure. At an angle of 25–27°, the flow is smooth, the velocity distribution is uniform across the width of the channel. In some cases, the forced expansion of the cross-section at the outflow of the weir favours the energy dissipation and uniform flow velocity distribution.
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Authors and Affiliations

Zhuzbay Kassymbekov
1
Abai Shinibaev
1
Galimzhan Kassymbekov
1

  1. Satbayev University, Satpayev Str., 22, Almaty, 050013, Kazakhstan
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Abstract

A flood occurs for many reasons, such as excessive rainfall, runoff coefficient, or an insufficient river channel capacity. The discharge flowing through the floodway depends on the maximum main river dimension that can be normalized. LU/LC changes are affected by runoff discharge, and runoff discharge is affected by the floodway design. The study dis-cusses the effect of land use (LU) or land cover (LC) changes and the design of floodway channel dimensions in the Kali Kemuning watershed, East Java Province, Indonesia. The Nakayasu synthetic unit hydrograph has been used to analyse the runoff discharge, and the Hydrologic Engineering Center’s River Analysis System software analysed the hydraulic proper-ties of river and floodway channels. Results show that the floodway channel design is determined by LU/LC conditions, and the river channel is normalized toward its maximum dimensions. Normalized channel depths and widths vary from 4 to 7 m and 16 to 46 m, respectively. The floodway channel is rectangular, with a bottom width of 10 m and depth of 4.5 m. With the runoff coefficient equal to 0.75, these normalized channel and floodway dimensions are suitable for the flood up to the 100-year return period runoff discharge.
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Authors and Affiliations

Agus Suharyanto
1
ORCID: ORCID
Yatnanta P. Devia
1
ORCID: ORCID
Indradi Wijatmiko
1
ORCID: ORCID

  1. Universitas Brawijaya, Faculty of Engineering, Civil Engineering Department, Jl. MT Haryono 167, Malang 65145, Jawa Timur, Indonesia
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Abstract

The ergodic channel capacity of wireless optical multiple-input multiple-output (MIMO) system with pulse position modulation (PPM) is investigated. The combined effects of atmospheric turbulence, atmospheric attenuation, pointing error and channel spatial correlation are taken into consideration. The expression of ergodic channel capacity is derived, and is further performed by Wilkinson approximation method for simplicity. The simulation results indicated that the strong spatial correlation has the greatest influence on the ergodic channel capacity, followed by pointing errors and atmospheric turbulence. Moreover, the ergodic channel capacity growth brought by space diversity only performs well under independent and weakly correlated channels. Properly increasing the size and spacing of the receiving apertures is an effective means of effectively increasing the ergodic channel capacity.
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Bibliography

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[2] J. Anshul, and M. R. Bhatnagar, “Free-space optical communication: a diversity-multiplexing trade-off perspective,” IEEE Transactions on Information Theory, vol. 65, no. 2, pp. 1113-1125, 2019. DOI: 10.1109/TIT.2018.2856116.
[3] P. Kaur, V. K. Jain, and S. Kar, “Performance analysis of free space optical links using multi-input multi-output and aperture averaging in presence of turbulence and various weather conditions,” Communications Iet, vol. 9, no. 8, pp. 1104-1109, May. 2015. DOI: 10.1049/iet-com.2014.0926
[4] Y. Zhang, H. Yu, J. Zhang, and Y. Zhu, “Space codes for MIMO optical wireless communications: Error performance criterion and code construction,” IEEE Transcation on Wireless Communication, vol. 16, no. 5, pp. 3072-3085, 2017. DOI: 10.1109/TWC.2017.2675398
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[10] H. S. Khallaf, J. M. Garrido-Balsells, H. M. H. Shalaby, and Seiichi Sampei, “SER analysis of MPPM-Coded MIMO-FSO system over uncorrelated and correlated Gamma-Gamma atmospheric turbulence channels,” Optics Communications, vol. 356, pp. 530-535, Aug. 2015. DOI: 10.1016/j.optcom.2015.08.060 [11] M. Petkovic, J. Anastasov, G.T. Djordjevic, and P. Ivanis, “Impact of correlation on outage performance of FSO system with switch-and-stay diversity receiver,” 2015 IEEE International Conference on Communications (ICC), London, 2015, pp. 2756–2761, DOI: 10.1109/ICC.2015.7248743. [12] T. Ozbilgin, and M. Koca, “Inter-aperture correlation in MIMO free space optical systems,” Optics Communications, vol. 353, pp. 139–146, May. 2015. DOI: 10.1016/j.optcom.2015.05.025. [13] A. Garacia-Zambrana, B. Castillo-Vazquez, and C. Castillo-Vazquez, “Asymptotic error-rate analysis of FSO links using transmit laser selection over gamma-gamma atmospheric turbulence channels with pointing errors,” Optics Express, vol. 20, no. 3, pp. 2096-2109, Jan. 2012. DOI: 10.1364/OE.20.002096 [14] M. R. Bhatnagar, and Z. Ghssemlooy, “Performance analysis of Gamma–Gamma fading FSO MIMO links with pointing errors,” Journal of Lightwave Technology, vol. 34, no. 9, pp. 2158-2169, May 2016. DOI: 10.1109/JLT.2016.2526053 [15] I. E. Lee, Z. Ghassemlooy, W. P. Ng, M. A. Khalighi, and S. K. Liaw, “Effects of aperture averaging and beam width on a partially coherent Gaussian beam over free-space optical links with turbulence and pointing errors,” Applied Optics, vol. 55, no. 1, pp. 1-9, Feb. 2016. DOI: 10.1364/AO.55.000001 [16] H. Zhang, H. Li, D. Xiao, and S. Ning, “Performance analysis of spatial-diversity reception over combined effects of atmospheric turbulence,” Chinese Journal of Lasers, vol. 43, no. 4, pp. 0405002, Apr. 2016. DOI: 10.3788/CJL201643.0405002 [17] C. Martin and B. Ottersten, “Asymptotic eigenvalue distributions and capacity for MIMO channels under correlated fading,” IEEE Transcations on Wireless Communications, vol. 3, no. 4, pp. 1350-1359, Aug. 2004. DOI: 10.1109/TWC.2004.830856 [18] H. Moradi, M. Falahpour, H.Refai, and P. Lopresti, “BER analysis of optical wireless signals through lognormal fading channels with perfect CSI,” IEEE 17th International Conference on Telecommunications (ICT ‘10), Doha, pp. 493-497, 2010. DOI: 10.1109/ICTEL.2010.5478870 [19] S. L. Loyka, “Channel capacity of MIMO architecture using the exponential correlation matrix,” IEEE Communications Letters, vol. 5, no. 9, pp. 369-371, Oct. 2001. DOI: 10.1109/4234.951380
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Authors and Affiliations

Minghua Cao
1
Yue Zhang
1
Zhongjiang Kang
1
Huiqin Wang
1

  1. School of Computer and Communication, Lanzhou University of Technology, Lanzhou, China
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Abstract

Potentially hazardous side-channels of complex geometry need to be investigated using detailed hydraulic physical models. This study aims to analyse the cross-waves pattern and pulsating flow using a side-channel spillway physical model. This study compares the cross-waves pattern were measured using an experimental installation set to generate cross-waves on the surface (original series) with another structure that did not produce cross-waves (modified series). The results showed that the geometry of the left wall caused instability in flow patterns and secondary flows. The starting point of Q 2 discharge was detected by minor turbulence on the water surface near the left wall at a water depth of 3.3 m at the starting point of the wall, but with no overtopping. Cross-waves formed downstream at the right wall crosswise, lower than at the left wall. The height of the cross-wave increased substantially from Q 100 to Q 1000 discharges leading to overtoppings near the left wall at a water depths of 4.2 and 5.0 m at the starting point of the wall, and near the right wall at a water depths of 3.8 and 4.0 m at the upstream point of the wall. The modifications provided optimal hydraulic conditions, i.e. elimination of cross-waves and non-uniform flows. The Vedernikov and Montouri numbers showed that both original and modified series did not enter the area where the pulsating flow occurred. This indicated that both series were free from the pulsating flow.
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Authors and Affiliations

Azmeri Azmeri
1
ORCID: ORCID
Chairatun Ummah
1
ORCID: ORCID
Faris Zahran Jemi
2
ORCID: ORCID
Imam Faudli
1
ORCID: ORCID
Qurratul 'Aini Benti Nasaiy
1

  1. Universitas Syiah Kuala, Engineering Faculty, Civil Engineering Department, Jl. Tgk. Syech Abdur-Rauf No. 7, Darussalam, 23111, Banda Aceh, Indonesia
  2. Universitas Syiah Kuala, Engineering Faculty, Electrical Engineering Department, Darussalam, Banda Aceh, Indonesia
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Abstract

Flood inundation processes in urban areas are primarily affected by artificial factors such as drainage facilities, local al-terations of topography and land uses. The objective of this study is to examine the capability of hydrological model SI-MODAS to estimate runoff and investigating the utilization of storage well in controlling runoff in a residential area. The result of the estimated runoff from the hydrological model was compared with the existing capacity of the drainage channel to identify which channel experienced the problem of inundation. The location of inundation was used to determine the location and number of storage well. The results showed that SIMODAS model could be applied in runoff analyses with 8.09% of relative error compared with runoff depth from field measurement. The existing capacity of the channel could not accommodate runoff Q10yr where the inundation discharge was approximately 0.24 m3·s–1 (at outlet point 1) and 0.12 m3·s–1 (at outlet point 2). The inundation problem was overcome by using a combination system between channel normalization (reduce 35% of total inundation discharge) and storage well system (reduce 65% of total inundation discharge). The storage well was designed at 20 locations (at outlet point 1) and 16 locations (at outlet point 2) which each well had a discharge of 0.0058 m3·s–1. The storage well combined with channel normalization could be used as an alternative way to solve inunda-tion problems in a residential area considering the constraint of land space limitation in the urban area.

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Authors and Affiliations

Donny Harisuseno
ORCID: ORCID
Mohammad Bisri
Tunggul S. Haji
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Abstract

To reduce the sediment transport capacity, shear stress needs to be reduced as well. The article describes work that has been done to find a way to make these reductions possible. The theoretical study and the approach proposed allowed us to obtain a general equation that determines conditions and calculates the most important parameters which support the reduction of shear stress. This describes the mechanism that erodes soils by free surface water flow.
In a similar vein, we have shown that adding a short non-prismatic channel to the entrance of a prismatic channel, which has the same geometric shape, is a very powerful way to reduce shear stress. With the idea of reducing shear stress, we have shown that the water-surface profile type plays a key role and must therefore be included in future reflections on reducing the importance of shear stress.
Additionally, the notion of efficiency was introduced that allows to evaluate the expected gain after the reduction of shear stress and adding a short non-prismatic channel.
The laws of similarity applied to free surface flows allowed us to obtain an equation with several equivalence scales and compare different geometric shapes in terms of their efficiency in the reduction of shear stress.
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Bibliography

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Authors and Affiliations

Samir Haddad
1 2
ORCID: ORCID

  1. Houari Boumediène University of Sciences and Technology, Faculty of Civil Engineering. LEGHYD Laboratory, BP 32 Bab Ezzouar, 16111 Algiers, Algeria
  2. Akli Mohand Oulhadj University of Bouira, Rue Frères Boussendalah, 10000 Bouira, Algeria
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Abstract

The mean flow characteristics in a curved channel are really different from those in a straight channel. The main cause is the existence of secondary flow within the flow in the curved channel. This paper will discuss the differences in mean flow characteristics due to changes in the bed topography in the curved channel. Acoustic Doppler Velocimetry (ADV) measurements have helped to analyse characteristics of the mean flow on flat and eroded beds in a 180° curved channel. Sand (mean diameter d 50 = 0.001 m and specific gravity Gs = 2.65) was selected as the bed material. The condition of flow in the approach section was steady and uniform with 0.159 m depth. One of the mean flow characteristics in the curved channel is the free surface superelevation due to the presence of centrifugal force. The second is the circular motion toward the inner-bank region at the lower layer and toward the upper layer outer-bank region. The cause of the circulation is the difference in centrifugal forces between the two layers. The magnitude of velocity near the bed surface is more significant than the flow near the water surface. This causes erosion in the outer bank region and deposition in the inner bank region. In general, tangential velocity vθ in flat bed is greater than its tangential velocity in eroded bed. The maximum velocity path in a flat and eroded bed of the curved channel resembles a sinusoidal curve, where the minimum value is located at 90° and 120° of the curve.
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Authors and Affiliations

Sumiadi Sumiadi
1
ORCID: ORCID
Moh Abduh
2
ORCID: ORCID

  1. University of Brawijaya, Jl. Veteran, Ketawanggede, Malang 65145, Indonesia
  2. Universitas Muhammadiyah Malang, Malang, Indonesia
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Abstract

Wireless Local Area Networks present several vulnerabilities that are exploited, and as a result, numerous attacks have been developed and used against them. Although countermeasures to detect and eliminate such threats have been created throughout the years, few methods exist to prevent the attacks. IEEE 802.11 covert channels could be considered a candidate to prevent Wi-Fi attacks since they allow secret communication between the client station and the access point without establishing an association. They can be implemented in frames that attackers do not target. This paper presents a new covert channel that prevents Wi-Fi attacks. We also describe metrics, and discuss the performance results of the proposed solution. We show that the new protocol is able to achieve high efficiency of operation.
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Authors and Affiliations

Geovani Teca
1
Marek Natkaniec
1

  1. Faculty of Computer Science, Electronics and Telecommunications, Institute of Telecommunications, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

This research proposed a model of Enhanced Distributed Channel Access (EDCA) scheme which is one of the techniques used in reducing collision and usually prioritized due to its contention window to determine the impact of distance change on the IEEE 802.11 ah standard. The proposed model was analyzed using the Markov Chain approach to determine the effect of distance change on collisions levels while the numerical were simulated using MATLAB. Moreover, the Markov chain solution was used to evaluate parameters such as throughput, energy consumption, and delay. The results showed the increment in RAW slot duration and the distance change for each station can reduce the performance on the standard and the scenario when the RAW slot duration was changed by 50 ms performed better than 100 ms and 250 ms.
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Authors and Affiliations

Doan Perdana
1
Amirah Amaliah Sakhrul
1
Bayu Erfianto
1
Abdul Aziz Marwan
1

  1. Telkom University, Indonesia
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Abstract

The article examines the trends in social communication in Poland in 1980–1981. Having analyzed multiple sources and research studies, the author comes to the conclusion that in this watershed period in Polish postwar history was characterized not only by stricter control of the official information channels but also a grassroot pushback manifested in the rise of uncensored bulletins, leaflets and propaganda posters.
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Authors and Affiliations

Tomasz Mielczarek
1
ORCID: ORCID

  1. Instytut Mediów, Dziennikarstwa i Komunikacji Społecznej, Uniwersytet Jana Kochanowskiego w Kielcach, ul. Uniwersytecka 17 PL 25-406 Kielce
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Abstract

The relationships between the conditions that describe the shape of the flow and power consumption characteristics and the pump design and performance parameters are described. These relations concern: - flow characteristics (throttling curves) described with a fourth-order polynomial, - non-overloading power consumption characteristics of the pump. The pumps that have to exhibit such characteristics are these designed to operate in an arbitrary installation. These pumps must also be characterised by cavitation-free operation in the whole range of discharge variability. In the relations presented, the condition of cavitation-free operation is considered as well.
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Authors and Affiliations

Andrzej Blaszczyk
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Abstract

Non-Orthogonal Multiple Access (NOMA) in the fifth generation (5G) system is one of the optimistic technologies for wireless radio access networks. Compared to orthogonal multiple accesses (OMA) reduce the spectral efficiency; NOMA provides the best solution by increasing the data rates. This study evaluates NOMA with a downlink in the automatic deployment of multiusers. The outage performance and ergotic sum-rate gain give the NOMA better performance can be concluded at the final results. NOMA provides the Quality of Service (QoS) to the multi-users by considering the power allocation and data rate factors. Here is considered the outage probability will be 1 when it identifies the different user and allocates the data rate and power.
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Authors and Affiliations

Suprith P. G
1
Mohammed Riyaz Ahmed
2

  1. REVA University, Bangalore, and Karnataka, India
  2. School of Multidisciplinary, REVA University, Bangalore, and Karnataka, India
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Abstract

Nowadays, there is a trend to employ adaptive solutions in mobile communication. The adaptive transmission systems seem to answer the need for highly reliable communication that serves high data rates. For efficient adaptive transmission, the future Channel State Information (CSI) has to be known. The various prediction methods can be applied to estimate the future CSI. However, each method has its bottlenecks. The task is even more challenging while considering the future 5G/6G communication where the employment of sub-6 GHz and millimetre waves (mmWaves) in narrow-band, wide-band and ultra-wide-band transmission is considered. Thus, author describes the differences between sub-6 GHz/mmWave and narrow-band/wide-band/ultrawide- band channel prediction, provide a comprehensive overview of available prediction methods, discuss its performance and analyse the opportunity to use them in sub-6 GHz and mmWave systems. We select Long Short-Term Memory Recurrent Neural Network (RNN) as the most promising technique for future CSI prediction and propose optimising two of its parameters - the number of input features, which was not yet considered as an opportunity to improve the performance of CSI prediction, and the number of hidden layers.
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Authors and Affiliations

Maciej Soszka
1

  1. Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland
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Abstract

Filter bank multicarrier waveform is investigated as a potential waveform for visible light communication broadcasting systems. Imaginary inter-carrier and/or inter-symbol interference are causing substantial performance degradation in the filter bank multicarrier system. Direct current-biased optical filter bank multicarrier modulation overcomes all the problems of direct current-biased optical-orthogonal frequency division multiplexing modulation approaches in terms of speed and bandwidth. However, it also wastes a lot of energy while transforming a true bipolar signal into a positive unipolar signal by adding direct current-bias. In this paper, a flip-filter bank multicarrier-based visible light communication system was introduced to overcome this problem. In this system, a bipolar signal is converted to a unipolar signal by isolating the positive and negative parts, turning them to positive and then delivering the signal. Also, a new channel estimation scheme for a flip-filter bank multicarrier system is proposed which improves the channel estimation performance compared to that of each of the conventional schemes. The proposed system performance is measured in terms of bit error rate, normalized mean squared error, and constellation diagram. The superiority of the proposed scheme over other conventional structures has been successfully verified by MATLAB 2020b simulation experiments results. These results are evaluated under indoor visible light communication standard.
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Authors and Affiliations

Mohamed Y. El-Ganiny
1
Ashraf A. M. Khalaf
2
ORCID: ORCID
Aziza I. Hussein
3
ORCID: ORCID
Hesham F. A. Hamed
4

  1. Department of Electrical Engineering, Higher Technological Institute, 10th of Ramadan City, Sharqia, Egypt
  2. Department of Electrical Engineering, Faculty of Engineering, Minia University, Minia, Egypt
  3. Electrical and Computer Engineering Department, Effat University, Jeddah, Kingdom of Saudi Arabia
  4. Department of Telecommunications Engineering, Egyptian Russian University, Badr City, Egypt
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Abstract

The article discusses the monitoring of horizontal displacements of the channel of Dniester, the second largest river in Ukraine, based on topographic maps, satellite images, as well as geological, soil and quaternary sediment maps. Data pro-cessing has been carried out using the geographic information system ArcGIS. The monitoring over a 140-year period (1874–2015) has been performed at the river’s transition from a mountainous to plain terrain on the 67 km section of the river. During this period, maximum displacements in the study area were 590–620 m. The research examines water protection zones needed for channel displacements. The article describes the monitoring methodology and analyses changes over a pe-riod of 18 years (2000–2018). The analysis includes the anthropogenic influence on the channel in the monitoring area. Results of the research may be useful for construction and cadastral works related to the channel in the area concerned, as well as for water management.
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Authors and Affiliations

Volodymyr Shevchuk
1
ORCID: ORCID
Khrystyna Burshtynska
1
ORCID: ORCID
Iryna Korolik
1
ORCID: ORCID
Maksym Halochkin
1
ORCID: ORCID

  1. Lviv Polytechnic National University, Institute of Geodesy, Department of Photogrammetry and Geoinformatics, Stepana Bandery St, 12, Lviv, Lviv Oblast, 79000, Ukraine

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