Fakulta elektrotechniky a informatiky / Faculty of Electrical Engineering and Computer Science (FEI)http://hdl.handle.net/10084/8912018-06-20T11:42:12Z2018-06-20T11:42:12ZHybrid full-duplex/half-duplex relay selection scheme with optimal power under individual power constraints and energy harvestingNguyen, Hoang-SyNguyen, Thanh-SangVo, Viet-TriVozňák, Miroslavhttp://hdl.handle.net/10084/1273182018-06-19T05:29:25Z2018-01-01T00:00:00ZHybrid full-duplex/half-duplex relay selection scheme with optimal power under individual power constraints and energy harvesting
Nguyen, Hoang-Sy; Nguyen, Thanh-Sang; Vo, Viet-Tri; Vozňák, Miroslav
In practice, full-duplex (FD) transmission achieves better system outage performance than that of half-duplex (HD) transmission but suffers from strong self-interference (SI). In this paper, we provide performance analysis of relay selection (RS) schemes in multi-relay wireless networks, where we obtain the exact and approximate closed-form expressions for outage probability (OP) in the high signal-to-noise ratio (SNR) regime over independent and identically distributed (i.i.d.) Rayleigh fading channels in three proposed optimal RS schemes, i.e., HD deploying maximal ratio combine (HDMRC) and FD deploying joint decoding (FDJD) and hybrid FD/HD relaying transmission scheme (HTS). Most importantly, these schemes operate in two proposed optimal power supply policies so-called optimal power under the individual power constraints (OPIPC) and optimal power with energy harvesting ability (OPEHA). Additionally, asymptotic expressions in high SNR regime are given to help gain better insights on the system performance. It is also shown that the proposed HTS scheme outperforms HDMRC and FDJD schemes in terms of outage performance, where OPEHA is better than OPIPC under the impact of SI. Besides that, HTS RS scheme significantly decreases the power consumption which helps enhance energy efficiency. The validity of the proposed analyses is proven by simulations.
2018-01-01T00:00:00ZExperimental grounding of the efficiency of the use of elastic operating elements in the devices for pre-sowing seed treatmentsSukhanova, M. V.Zabrodin, V. P.Sukhanov, A. V.Stýskala, VítězslavZegzulka, JiříJezerská, LucieRozbroj, Jiříhttp://hdl.handle.net/10084/1273062018-06-18T11:10:57Z2017-01-01T00:00:00ZExperimental grounding of the efficiency of the use of elastic operating elements in the devices for pre-sowing seed treatments
Sukhanova, M. V.; Zabrodin, V. P.; Sukhanov, A. V.; Stýskala, Vítězslav; Zegzulka, Jiří; Jezerská, Lucie; Rozbroj, Jiří
The article is devoted to the experimental studies of the effect of elastic operating elements of a mixer-dresser on seeds. Conducted experimental studies have shown the effectiveness of using the elastic operating elements for pre-sowing seed treatments. The proposed device is intended for the intensification of the process of mixing and dressing, excluding the traumatizing of seeds, and the harmful effect of protectant preparations on maintenance workers, while simplifying and reducing the cost of construction without additional power inputs. Experimental studies have confirmed the hypothesis, that the use ofshells, made of elastic materials,in the function of mixing devices, significantly reduces the time of preparation of homogeneous mixtures, due to the ability to accumulate the potential energy and to transfer it to the granular material,in the form of kinetic energy of mixed particles motion. Based on the performed researches, 3D model of the device for pre-sowing seed treatments has been developed. Hybrid elastic mixer-dressers can be used in agricultural enterprises, dealing with the issues of obtaining multicomponent granular mixtures and seed dressing.
2017-01-01T00:00:00ZComparative effectiveness of ICA and PCA in extraction of fetal ECG from abdominal signals: Toward non-invasive fetal monitoringMartinek, RadekKahánková, RadanaJeżewski, JanuszJaroš, RenéMohylová, JitkaFajkus, MarcelNedoma, JanJanků, PetrNazeran, Homerhttp://hdl.handle.net/10084/1272982018-06-15T12:10:01Z2018-01-01T00:00:00ZComparative effectiveness of ICA and PCA in extraction of fetal ECG from abdominal signals: Toward non-invasive fetal monitoring
Martinek, Radek; Kahánková, Radana; Jeżewski, Janusz; Jaroš, René; Mohylová, Jitka; Fajkus, Marcel; Nedoma, Jan; Janků, Petr; Nazeran, Homer
Non-adaptive signal processing methods have been successfully applied to extract fetal electrocardiograms (fECGs) from maternal abdominal electrocardiograms (aECGs); and initial tests to evaluate the efficacy of these methods have been carried out by using synthetic data. Nevertheless, performance evaluation of such methods using real data is a much more challenging task and has neither been fully undertaken nor reported in the literature. Therefore, in this investigation, we aimed to compare the effectiveness of two popular non-adaptive methods (the ICA and PCA) to explore the non-invasive (NI) extraction (separation) of fECGs, also known as NI-fECGs from aECGs. The performance of these well-known methods was enhanced by an adaptive algorithm, compensating amplitude difference and time shift between the estimated components. We used real signals compiled in 12 recordings (real01-real12). Five of the recordings were from the publicly available database (PhysioNet-Abdominal and Direct Fetal Electrocardiogram Database), which included data recorded by multiple abdominal electrodes. Seven more recordings were acquired by measurements performed at the Institute of Medical Technology and Equipment, Zabrze, Poland. Therefore, in total we used 60 min of data (i.e., around 88,000 R waves) for our experiments. This dataset covers different gestational ages, fetal positions, fetal positions, maternal body mass indices (BMI), etc. Such a unique heterogeneous dataset of sufficient length combining continuous Fetal Scalp Electrode (FSE) acquired and abdominal ECG recordings allows for robust testing of the applied ICA and PCA methods. The performance of these signal separation methods was then comprehensively evaluated by comparing the fetal Heart Rate (fHR) values determined from the extracted fECGs with those calculated from the fECG signals recorded directly by means of a reference FSE. Additionally, we tested the possibility of non-invasive ST analysis (NI-STAN) by determining the T/QRS ratio. Our results demonstrated that even though these advanced signal processing methods are suitable for the non-invasive estimation and monitoring of the fHR information from maternal aECG signals, their utility for further morphological analysis of the extracted fECG signals remains questionable and warrants further work.
2018-01-01T00:00:00ZEquivalent formulations of the Riemann hypothesis based on lines of constant phaseSchleich, Wolfgang P.Bezděková, IvaKim, Moochan B.Abbott, Paul C.Maier, HelmutMontgomery, Hugh L.Neuberger, John W.http://hdl.handle.net/10084/1272952018-06-11T11:35:17Z2018-01-01T00:00:00ZEquivalent formulations of the Riemann hypothesis based on lines of constant phase
Schleich, Wolfgang P.; Bezděková, Iva; Kim, Moochan B.; Abbott, Paul C.; Maier, Helmut; Montgomery, Hugh L.; Neuberger, John W.
We prove the equivalence of three formulations of the Riemann hypothesis for functions f defined by the four assumptions: (a1) f satisfies the functional equation f (1 - s) = f (s) for the complex argument s = sigma + i tau, (a2) f is free of any pole, (a3) for large positive values of s the phase. of f increases in a monotonic way without a bound as tau increases, and (a4) the zeros of f as well as of the first derivative f ' of f are simple zeros. The three equivalent formulations are: (R1) All zeros of f are located on the critical line sigma = 1/2, (R2) All lines of constant phase theta of f corresponding to +/-pi, +/- 2 pi, +/- 3 pi, ... merge with the critical line, and (R3) All points where f' vanishes are located on the critical line, and the phases of f at two consecutive zeros of f' differ by pi. Our proof relies on the topology of the lines of constant phase of f dictated by complex analysis and the assumptions (a1)-(a4). Moreover, we show that (R2) implies (R1) even in the absence of (a4). In this case (a4) is a consequence of (R2).
2018-01-01T00:00:00Z