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1
Content available Effects of Multipath and Conventional NMES on Maximum Comfortable Stimulus and Torque Production
100%
Bremner C. B. , Holcomb W. R.
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nr 1
23-33
EN
A novel multipath NMES (m-NMES) device has shown improved outcomes relative to conventional NMES (c-NMES) during recent basic and training studies. However, the mechanisms by which m-NMES outperformed c-NMES remain unclear. This study aimed to better understand these mechanisms by comparing the effects of m-NMES and c-NMES on maximum comfortable stimulus intensity and the subsequent NMES-induced torque, as these variables ultimately impact NMES training intensity; which is considered to be the primary determinant of NMES effectiveness. We measured maximum comfortable stimulus intensity and the subsequent NMES-induced torque while participants performed NMES-induced contractions under two conditions (m-NMES and c-NMES). Maximum comfortable stimulus intensity was significantly greater under the m-NMES condition, but the subsequent NMES-induced torque was not significantly different across conditions. m-NMES does not appear to influence the outcomes in a clinically meaningful manner, since it performed similarly to c-NMES with respect to peak NMES-induced torque.
2
Content available remote Edge decompositions of multigraphs into multi-2-paths
88%
Kratochvil J. , Lonc Z. , Meszka M. , Skupień Z.
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2004
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tom Vol. 24, no. 1
97-102
EN
We establish the computational time complexity of the existence problem of a decomposition of an instance multigraph into isomorphic 3-vertex paths with multiple edges. If the two edge multiplicities are distinct, the problem is NPC; if mutually equal then polynomial.
3
Wielodrogowość a niezawodność linii radiowej zakresu 6 GHz
75%
Bogucki J. , Wielowieyska E.
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2010
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tom Vol. 51, nr 4
117-119
PL
W artykule opisano wpływ zjawiska wielodrogowości na pracę linii radiowych zakresu 6 GHz. Przedstawiono wyniki pomiarów takich linii.
EN
This article describes the multipath phenomenon that determines the performance of a radio-relay path. Empirical fading in radio communication at 6 GHz band are showed too.
4
Content available remote Analiza precyzji i dokładności pomiarów GPS w warunkach leśnych
75%
Bakuła M. , Oszczak S. , Pelc-Mieczkowska R. , Suchocki M. , Chrostowska M. , Rudziński M.
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2006
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tom T. 4, z. 3
23-32
EN
The paper presents results of GPS measurements executed in forest conditions. The GPS measurements were made with the use of dual-frequency Ashtech Z-Xtreme receivers. The test measurements were performed in the forest at the University of Warmia and Masury in Olsztyn. Two different analyses were conducted: Real Time Positioning (RTK) and post-processing data elaboration. Postprocessing GPS data were elaborated with the use of Ashtech Office Suite (AOS) software. After very careful study of static elaborations centimeter accuracy was achieved, though large errors (a few meters) could occur. Gross errors were caused by heavy obstructions due to tree canopy. It caused frequent losses of contact with satellites as well as multipath errors. Similarly in the case of RTK measurements thanks to multiple initialization of ambiguity resolution centimeter accuracy was also obtained. However, GPS/RTK measurements demand large experience in GPS elaboration as well as very thorough knowledge of GPS positioning. Very important issue is careful planning of GPS sessions as well as applying appropriate GPS receiver sets. Future combination of GPS and GLONASS with GALILEO systems will bring considerable improvement in getting reasonable results in forest conditions, especially RTK positioning seems very costeffective in forest conditions.
5
Czasy trwania zaników w liniach radiowych zakresu 6 GHz
75%
Bogucki J. , Wielowieyska E.
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2012
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tom Vol. 53, nr 7
120-124
PL
Omówiono zjawisko propagacji wielodrogowej mające wpływ na niezawodność propagacyjną horyzontowych linii radiowych. Przedstawiono dane pomiarowe ilustrujące skutki występowania tego zjawiska, a mianowicie czasy trwania zaników.
EN
The article describes propagation multipath phenomenon influence on the propagation reliability of terrestrial line-of-sight radio links. Experimental data - duration time of fadings - illustrating that phenomenon have been shown.
6
Content available LC phase bias investigation of ASG-EUPOS stations
75%
Araszkiewicz A. , Szafranek K.
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nr 2
7
Content available Multipath detection with the combination of SNR measurements – Example from urban environment
63%
Špánik P. , Hefty J.
Geodesy and Cartography
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2017
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tom Vol. 66, no. 2
305--315
EN
Multipath is one of the most severe station-dependent error sources in both static and kinematic positioning. Relatively new and simple detection technique using the Signal-to-Noise (SNR) measurements on three frequencies will be presented based on idea of Strode and Groves. Exploitation of SNR measurements is benefi cial especially for their unambiguous character. Method is based on the fact that SNR values are closely linked with estimation of pseudo-ranges and phase measurements during signal correlation processing. Due to this connection, combination of SNR values can be used to detect anomalous behavior in received signal, however some kind of calibration in low multipath environment has to be done previously. In case of multipath, phase measurements on different frequencies will not be affected in the same manner. Specular multipath, e.g. from building wall introduces additional path delay which is interpreted differently on each of the used carrier, due to different wavelengths. Experimental results of multipath detection in urban environment will be presented. Originally proposed method is designed to work with three different frequencies in each epoch, thus only utilization of GPS Block II-F and Galileo satellites is possible. Simplification of detection statistics to use only two frequencies is made and results using GPS and GLONASS systems are presented along with results obtained using original formula.
8
Content available remote Performance of massive MIMO systems under the effect of fading channel
63%
Alzamil A. A.
Przegląd Elektrotechniczny
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2021
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tom R. 97, nr 1
53--55
EN
This paper evaluates the performance of an uplink OFDM-based communication system considering multipath propagation environment where a Massive MIMO approach is exploited. In this context, Zero Forcing detector is used and assessed. Numerical analysis of the mathematical model was conducted on MATLAB. The results presented in this paper include Bit Error rate (BER) and the channel capacity of QPSK/OFDM transmission through a fading channel. Performance results verify the positive effect of Massive MIMO even when reduced complexity detection technique is used.
PL
Analizowano właściwości systemu komunikacyjnego bazującego na OFDM. Uwzględniono wielostrumieniowy rozsył z eksploatacja dużego MIMO. Opracowano model matematyczny I przeprowadzono symulację określającą BER I pojemność kanału dla przesyłu QPSK/OFDM.
9
Content available Review of Applications of the Laboratory for Electromagnetic Compatibility Infrastructure
51%
Staniec K. , Jóskiewicz Z. , Janukiewicz J. , Więckowski T.
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tom Vol. 66, No. 1
107--123
EN
This article provides a thorough description of a range of non-standard application cases in which EMC laboratories can be used other than those traditionally associated with this kind of facilities. The areas covered here include investigations of: wireless and radio systems (such as IoT and broadband radio systems) also that require ultra-high operational dynamic range, emulation of interference-free and/or heavilymultipath propagation environment, shielding effectiveness of cabinets and materials (i.e. thin, light and flexible as textiles as well as heavy and thick such as building construction elements).
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