Implementation of brute force algorithm for topology optimisation of wireless networks

The paper discusses the topology optimisation of wireless networks using a brute force algorithm. In order to reduce the computational complexity of the algorithm the multi-thread application has been implemented to conduct the optimisation procedure. The efficiency of the algorithm was verified using an example task where topology of a wireless network has been optimised under various criteria

Housing estate energy storage feasibility for a 2050 scenario

The further penetration of renewable sources in the grid requires the implementation of energy storages in order to smooth out the variability and intermittent nature of renewables. This paper looks at the possibilities for a storage solution to meet an unprecedented situation of having no power input from renewables or an outage from grid sources for five consecutive days in the highest demand period of the year. The study uses as test case a 1000 house estate in the year 2050 with each property using electrical heating and electrical vehicle charging. The magnitude of power and energy estimated, together with the practicalities is then used to assess current storage solutions suitability and the likely possibilities of new innovations in the storage environment

A simulation model for the control of electric vehicles charging networks

This paper presents the details of software development and implementation of a simulation model to be used for performance analysis of the control applied for management of a plug-in electric vehicles charging network. The model is designed to provide an evaluation of the tested control algorithms in terms of efficiency and stability operation. Apart from the control algorithm evaluation the model can be used for assessment of required control modification. The model has been built using Java language under paradigms of object-oriented programming and test driven development

Design and Analysis of Compact Antenna for 5G Communication Devices

A novel slotted rectangular patch antenna for E and W band, which resonates at the frequency of 67 GHz and has impedance bandwidth of 13.2 GHz, is used for resolving the issues of compactness, gain and efficiency of antenna designs for future generation 5G devices such as watches, and dongles. The single element antenna, having a dimension of 5.5 × 4.7 × 0.381 mm3, with a realized gain of 8.9 dBi was achieved. A rectangular slot was placed in the ground plane, just under the feed line of a microstrip patch antenna (MSPA), and this works as a defected ground structure (DGS): this improved the gain by up to 2 dB in the proposed design. The partial ground is used for tuning the impedance bandwidth. The rationale for the DGS, the partial ground, and the effect of the slot technique are discussed and implemented in this paper

Broken bar fault diagnosis for induction machines under load variation condition using discrete Wavelet transform

The paper presents a new approach for detection of broken rotor bar fault in squirrel cage induction motors operating under varying load conditions. A mathematical model used in the presented method was developed using winding function approach to provide indication references for induction motor parameters under load variation. The model shows a strong relationship between broken rotor bar fault and stator current. The method is based on analysis of stator current using discrete wavelet transform. To verify the proposed method a squirrel cage induction motor with 1, 2 and 3 broken bars at no-load, half- and full-load conditions was investigated. Obtained experimental results confirmed the validity of the proposed approach

Ultra wideband antenna for future 5G

An ultra-wideband miniature antenna based on circular patch with circular slots has been presented for future generation mm-wave indoor wireless applications. The proposed miniature antenna is fed by probe feed and, the maximum realized gain and the total efficiency throughout the three bands are 7.7 dBi in an upper higher band and 97% in the lower band, respectively. This proposed antenna covers the seven bands (five bands are in the existing allocation to mobile, and the other two bands are to be considered for allocation) for 5G higher bands and lower band covers uplink Ku-band (14GHz - 14.5GHz) for satellite communication. The proposed antenna in ultra-wideband has the impedance bandwidth of 31.8 GHz and the fractional bandwidth of 60.61%

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM