Combined detection of supernova neutrino signals

Supernova neutrino detection in neutrino and dark matter experiments is usually implemented as a real-time trigger system based on counting neutrino interactions within a moving time window. The sensitivity reach of such experiments can be improved by taking into account the time profile of the expected signal. We propose a shape analysis of the incoming experimental data based on a log likelihood ratio variable containing the assumed signal shape. This approach also allows a combination of potential supernova signals in different detectors for a further sensitivity boost. The method is tested on the NOvA detectors to study their combined sensitivity to the core-collapse supernova signal, and also on KamLAND, Borexino and SK-Gd as potential detectors of presupernova neutrinos. Using the shape analysis enhances the signal significance for supernova detection and prediction, as well as the sensitivity reach of the experiment. It also extends the supernova prediction time when applied to the presupernova neutrino signal detection. Enhancements achieved with the shape analysis persist even in the case when the actual signal doesn't match the expected signal model.

Total power deficiency estimation of isolated power system network using full-state observer method

<span>An isolated electrical network with an independent local distributed generator is very sensitive towards the contingencies between load demand and supply. Although the network system has less complexity in term of structure, its stability condition is crucial due to its stand-alone operating condition. The total power deficit in the network gives the important information related to the dynamical frequency responses which may directly affect the system’s stability level. In this paper, the approach to estimate the total power deficiency for the isolated electrical network was presented by utilized the Luenberger observer method. Although the power deficit is not the state variable in the network mathematical model, the solution of estimation problem was feasible by introducing the new variable using additional dummy system. The simulation was carried out by using MATLAB/Simulink environment and the designed estimator was verified using multifarious load demand changes. The results show that the estimated signal was successfully tracked the expected actual signal with minimum error.</span>

Low Distortion of Noise Filter Realization with 6.34 V/μs Fast Slew Rate and 120 mVp-p Output Noise Signal

In order to reduce Gaussian noise, this paper proposes a method via taking the average of the upper and lower envelopes generated by capturing the high and low peaks of the input signal. The designed fast response filter has no cut-off frequency, so the high order harmonics of the actual signal remain unchanged. Therefore, it can immediately respond to the changes of input signal and retain the integrity of the actual signal. In addition, it has only a small phase delay. The slew rate, phase delay and frequency response can be confirmed from the simulation results of Multisim 13.0. The filter outlined in this article can retain the high order harmonics of the original signal, achieving a slew rate of 6.34 V/μs and an almost zero phase difference. When using our filter to physically test the input signal with a noise level of 3 Vp-p Gaussian noise, a reduced noise signal of 120 mVp-p is obtained. The noise can be suppressed by up to 4% of the raw signal.

Logic Learning in Adaline Neural Network

In this paper, Adaline Neural Network (ADNN) has been explored to simulate the actual signal processing between input and output. One of the drawback of the conventional ADNN is the use of the non-systematic rule that defines the learning of the network. This research incorporates logic programming that consists of various prominent logical representation. These logical rules will be a symbolic rule that defines the learning mechanism of ADNN. All the mentioned logical rule are tested with different learning rate that leads to minimization of the Mean Square Error (MSE). This paper uncovered the best logical rule that could be governed in ADNN with the lowest MSE value. The thorough comparison of the performance of the ADNN was discussed based on the performance MSE. The outcome obtained from this paper will be beneficial in various field of knowledge that requires immense data processing effort such as in engineering, healthcare, marketing, and business.

Lociranje parcijalnih pražnjenja u energetskom transformatoru primenom UHF tehnike

A specially developed algorithm used in the program in MATLAB in a simplified model of a large power transformer will determine the locations of partial discharges using four UHF sensors by simulating ten real waveforms from a source of partial discharges. Subsequent interpolation of the recorded signals will be performed, in order to obtain the closest possible shapes to the actual waveforms. Actual waveforms were obtained by experimenting with a single UHF sensor in a real large power transformer. The ten signals of the actual shape are mutually different heights of the initial several peaks and different shapes, but still have similar maximum amplitude, frequency spectrum and the prevailing frequency of the most prominent partial discharges. It was important to determine where the actual signal begins, for which a unique calculation procedure was made, and later to accurately determine the differences between the occurrences of the first (reference) peaks of the actual signals at individual sensors. The most favourable threshold value was taken into account when determining the differences in signal arrival times by the method of the first acceptable peak. The deviations in the calculated positions of the sources of partial discharges obtained for 120 randomly selected points in the volume of the transformer tank model will be analysed.

Superdeterministic hidden-variables models I: non-equilibrium and signalling

This is the first of two papers that attempt to comprehensively analyse superdeterministic hidden-variables models of Bell correlations. We first give an overview of superdeterminism and discuss various criticisms of it raised in the literature. We argue that the most common criticism, the violation of ‘free-will’, is incorrect. We take up Bell’s intuitive criticism that these models are ‘conspiratorial’. To develop this further, we introduce non-equilibrium extensions of superdeterministic models. We show that the measurement statistics of these extended models depend on the physical system used to determine the measurement settings. This suggests a fine-tuning in order to eliminate this dependence from experimental observation. We also study the signalling properties of these extended models. We show that although they generally violate the formal no-signalling constraints, this violation cannot be equated to an actual signal. We therefore suggest that the so-called no-signalling constraints be more appropriately named the marginal-independence constraints. We discuss the mechanism by which marginal-independence is violated in superdeterministic models. Lastly, we consider a hypothetical scenario where two experimenters use the apparent-signalling of a superdeterministic model to communicate with each other. This scenario suggests another conspiratorial feature peculiar to superdeterminism. These suggestions are quantitatively developed in the second paper.

A GPS Spoofing Generator Using an Open Sourced Vector Tracking-Based Receiver

Spoofing can seriously threaten the use of the Global Positioning System (GPS) in critical applications such as positioning and navigation of autonomous vehicles. Research into spoofing generation will contribute to assessment of the threat of possible spoofing attacks and help in the development of anti-spoofing methods. However, the recent commercial off-the-shelf (COTS) spoofing generators are expensive and the technology implementation is complicated. To address the above problem and promote the GPS safety-critical applications, a spoofing generator using a vector tracking-based software-defined receiver is proposed in this contribution. The spoofing generator aims to modify the raw signals by cancelling the actual signal component and adding the spoofing signal component. The connections between the spreading code and carrier, and the states of the victim receiver are established through vector tracking. The actual signal can be predicted effectively, and the spoofing signal will be generated with the spoofing trajectory at the same time. The experimental test results show that the spoofing attack signal can effectively mislead the victim receiver to the designed trajectory. Neither the tracking channels nor the positioning observations have abnormal changes during this processing period. The recent anti-spoofing methods cannot detect this internal spoofing easily. The proposed spoofing generator can cover all open-sky satellites with a high quality of concealment. With the superiority of programmability and diversity, it is believed that the proposed method based on an open source software-defined receiver has a great value for anti-spoofing research of different GNSS signals.

The slingshot effect as a probe of transverse motions of galaxies

Context. There are currently no reliable methods to measure the transverse velocities of galaxies. This is an important piece of information that is lacking in galaxy catalogues, and it could allow us to probe the physics of structure formation and to test the underlying theory of gravity. The slingshot effect (a special case of the integrated Sachs–Wolfe effect) is expected to create dipole signals in the temperature fluctuations of the cosmic microwave background (CMB) radiation. This effect creates a hot spot behind and a cold spot in front of moving massive objects. The dipole signal created by the slingshot effect can be used to measure transverse velocities, but because the signal is expected to be weak, the effect has not been measured yet. Aims. Our aim is to show that the slingshot effect can be measured by stacking the signals of galaxies falling into a collapsing cluster. Furthermore, we evaluate whether the effect can probe modified gravity. Methods. We used data from a simulated galaxy catalogue (MultiDark Planck 2) to mimic observations. We identified a 1015 M⊙ cluster, and made maps of the slingshot effect for photons passing near 8438 infalling galaxies. To emulate instrument noise, we added uncorrelated Gaussian noise to each map. We assumed that the average velocity is directed towards the centre of the cluster. The maps were rotated according to the expected direction of motion. This assures that the dipole signal adds up constructively when stacking the maps. We compared the stacked maps to a dipole stencil to determine the quality of the signal. We also evaluated the probability of fitting the stencil in the absence of the slingshot signal. Results. Each galaxy gives a signal of around ΔT/T ≈ 10−9, while the current precision of CMB experiments is ΔT/T ≈ 4 × 10−6. By stacking around 10 000 galaxies and performing a stencil fit, the slingshot signal can be over the detectable threshold with today’s experiments. However, due to the difficulty of distinguishing an actual signal from false positives, future CMB experiments must be used to be certain of the strength of the observed signal.

Impulse Noise Parameter Assessment in a Batch Radio Channel

Modern radio communication means to provide safe data transmission due to adapting radio channel to the actual noise environment. It is impossible to conduct proper comparative tests on various radio stations offered by manufacturers and to compare objectively the results obtained in field without actual signal parameters and noise environment instrument inspection at the reception point. The paper considers tactical level radio communications system operation when jammed with powerful impulse noise of various nature. It suggests a device enabling to assess the main parameters of impulse noise, namely desired signal and additive noise mixture envelope effective value, impulse noise envelope effective value, impulse noise duty factor. To provide measurement independence from a specific realization of a decoder it is suggested to use the envelope of a signal received by a radio station. The developed device uses standard radio channel data batches as measuring signals and does not require changing radio channel or radio network algorithms and timing charts. A method to assess the effective value of desired signal envelope and additive noise mean-square value when the received signal involves impulse noise is suggested. The paper demonstrates that valid assessment of desired signal and additive noise mixture is possible in case of setting aside selection values affected by impulse noise. A device separating symbols affected by impulse noise from those that are not affected is suggested. Formulas that allow synthesizing the device operation algorithms are obtained. The structure chart of the measurer is developed; the algorithms used to assess measured parameters are given.