bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deterministic submanifolds for the backward‐evolving quantum state concerning a monitored qubit
Authors: Miao Zibo , Zhang Zigui , Li Kai , Pan Yu , Sarlette Alain 
Published: October 2022

AbstractThe evolution of a quantum system subject to continuous weak measurement is described by a stochastic differential equation (SDE). It has been shown that the conventional density matrix characterized by such SDE, under experimentally relevant settings, remains within a deterministically evolving manifold of low dimension, whose associated equations can be computed explicitly. In this paper, as a complement, it is demonstrated that the effect matrix , associated to a quantum system at the time t to express its measurement during the interval , also remains confined to a deterministically evolving manifold. In particular, by using the Bloch sphere representation together with the properties of Pauli matrices (as the quantum representation of quaternions), deterministic submanifolds for the effect matrix concerning a monitored qubit are given explicitly. The qubit stays on a deterministically evolving curve in the homodyne amplitude detection scenario, and on a deterministically moving surface under heterodyne amplitude detection. This deterministic characterization should be of interest for parameter estimation and towards obtaining computationally efficient quantum filters for real‐time quantum control.
False‐alarm suppression with random forest by exploiting ambiguity features of targets
Authors: Wang Zhifei , Yu Junpeng , Yang Yuhao 
Published: October 2022

AbstractSuppressing false alarms without impacting detection rate is an essential issue for search radars. Traditional threshold detection methods identify true targets by simply comparing the energy of target candidates with a threshold. In this work, a new data‐driven false‐alarm suppression approach is proposed based on a random forest model. It discriminates true targets and false alarms in the developed multi‐dimensional ambiguity feature spaces, instead of the time‐frequency features used in previous works, to fulfill short dwell‐time requirement of search radars. Evaluations through field experiments demonstrate that the proposed method can achieve as high as 98% validation accuracy and a significant improvement of detection performance compared to the conventional threshold detection.
Fast intra partition and mode prediction for equirectangular projection 360‐degree video coding
Authors: Zheng‐Jie Shu , Zong‐Ju Peng , Gang‐Yi Jiang , Fen Chen , Bo‐Sen Yuan 
Published: October 2022

Abstract360‐degree videos have drawn great attention from both the academia and the industry. For transmission and storage of 360‐degree video, the joint video exploration team proposed the Versatile Video Coding (VVC) standard. VVC can significantly reduce the bitrate while maintaining the same subjective visual quality compared to the preceding high efficiency video coding. However, the computational complexity of VVC is extremely high which hinders the interactive applications. This paper proposes a fast intra partition method and mode prediction algorithm for equirectangular projection 360‐degree video coding. First, a latitude‐based preprocessing is introduced to early terminate the Coding Unit (CU) partition in the polar region. Second, the support vector machine is used to predict the CU partition type. Third, the fast intra mode search method accelerates the intra mode prediction. Experimental results show that the proposed algorithm can significantly obtain an average time reduction rate of 60.40% and a Bjontegaard delta rate increase of 1.96%.
Real‐time resilient microgrid power management based on multi‐agent systems with price forecast
Authors: Cruz Victorio Marcos Eduardo , Kazemtabrizi Behzad , Shahbazi Mahmoud 
Published: October 2022

AbstractMicrogrids have emerged to diversify conventional electric generation using small‐scale distributed generation. Large efforts have been put into designing control strategies to optimise the power schedules of microgrids, however, verification that such control systems also are reliable in terms of stability during normal operation and fault conditions is needed. This study presents a hierarchical distributed control system that fulfils these conditions for an AC microgrid. The stability maintained by proposed controller, considering the large signal model, is analysed with the use of Lyapunov's direct method. Resilient control distribution is achieved by the implementation of suitable forecast models and fault‐tolerance mechanisms to avoid single points of failure. The resilience of the control system is verified with the use of graph theory. The stable and resilient operation of the proposed control system is tested by a real‐time microgrid model implemented with an OPAL‐RT real‐time simulator, combined with a communication network built with Raspberry Pis, testing the control system presented under normal and faulty conditions. Simulation results show a stable operation in terms of voltage and frequency in both conditions, resilient operation is shown for the faulty condition case. Additionally, cost minimisation performance is included to validate optimal power management capabilities.
Comparison of wind speed forecasting models for power reserve scheduling in the congested transmission network
Authors: Zheng Yingying , Sang Yuanrui , Liu Chang , Zhu Jie , Cao Jinye , Zhao Yongning , Yang Dechang 
Published: October 2022

AbstractDue to its stochastic nature, wind energy imposes unprecedented challenges on the power grid, and a properly scheduled reserve is essential to accommodate wind power's intermittency and volatility. Many power reserve scheduling studies have considered the uncertainties of the renewable energy integration but few address how different wind speed forecast techniques influence the scheduling of reserves in the congested transmission networks. Here, three forecasting techniques: Artificial neural network, autoregressive integrated moving average, and probability distribution function‐based model are adopted to forecast one day of wind speed at Taylor, Texas in 2012. To evaluate the impacts of the forecast techniques on power reserve scheduling, a stochastic reserve optimization model was developed to ensure the delivery of reserve in the event of transmission congestion and ramping constraints. A modified RTS‐96 test system was employed and the results claim that different forecast models significantly affect the amount of scheduled up and down reserves in a stochastic reserve optimization problem. The level of operating reserve that is induced by wind is not constant during all hours of the day. Dynamic up and down reserves will be needed with a large scale of wind farm integration.
Environmental drivers of above-ground biomass in semi-arid rangelands
Authors: Kaveh Neda , Ebrahimi Ataollah , Asadi Esmaeil 
Published: October 2022

Above-ground biomass (AGB), as a key biophysical and functional parameter of rangeland ecosystems, plays an important role in ecosystem carbon (C) stocks. The aim of this study was to explore the important environmental drivers of AGB in an arid rangeland by using structural equation modelling (SEM). Vegetation and soil (physical and chemical properties) were sampled using randomised-systematic methods within sampling plots. The topographic (elevation, slope, aspect, hillshade (i.e. a technique for showing the topographical shape of hills and mountains to indicate relative slopes and mountain ridges)) and climatic (mean temperature (MT), mean precipitation (MP), actual evapo-transpiration (AET) and land-surface temperature (LST)) properties were extrapolated using a raster-based digital elevation-model (DEM) map, and their values extracted at each sampling plot. SEM was then applied to assess the direct and indirect impacts of environmental factors on AGB. The AGB was directly affected by soil (41%, P < 0.05) and climatic properties (34%, P < 0.05). The effect of topographical factors on AGB was non-significant (P > 0.05). However, climatic properties were directly affected by topographical properties, with a path coefficient of 34%. Among soil properties, nitrogen, phosphorus and potassium concentrations, silt content and soil pH were the key factors affecting AGB. Climatic variables (MT, MP) were equally effective in explaining the climate latent variable (with loading factors of −0.97 and 0.99 respectively) and AGB changes. This study highlighted the importance of soil and climatic properties in AGB variation. SEM simplified and revealed the complex relationships among ecosystem components affecting AGB, which could assist proper management of rangelands.
Ratiometric thermometry using single Er3+-doped CaWO4 phosphors
Authors: Kolesnikov Ilya E , Mamonova Daria V , Kurochkin Mikhail A , Medvedev Vassily A , Bai Gongxun , Kolesnikov Evgenii Yu 
Published: October 2022

Abstract
Single doped CaWO4:Er3+ phosphors were synthesized and studied for application of optical thermal sensing within a wide range of 98–773 K. Ratiometric strategy utilizing two luminescence intensity ratios, one between host and Er3+ band (LIR1) and second between different Er3+ transitions (LIR2), results in self-referencing temperature readouts. The presence of two temperature-dependent parameters could improve thermometric characteristics and broaden the working temperature range compared to a usual single-parameter thermometer. Thermometric performances of prepared samples were evaluated in terms of thermal sensitivities, temperature resolution and repeatability. The highest sensitivity of 2.09% K−1@300 K was found for LIR1, whereas LIR2 provided more accurate thermal sensing with a temperature resolution of 0.06–0.1 K. Effect of Er3+ doping concentration on sensing properties were studied. The presented findings indicate that CaWO4:Er3+ phosphors are perspective in dual-mode thermal sensing with high sensitivity and sub-degree resolution.
Surface ionization waves propagating over non-planar substrates: wavy surfaces, cut-pores and droplets
Authors: Konina Kseniia , Kruszelnicki Juliusz , Meyer Mackenzie E , Kushner Mark J 
Published: October 2022

Abstract
Atmospheric pressure plasmas intersecting with dielectric surfaces will often transition into surface ionization waves (SIWs). Several applications of these discharges are purposely configured to be SIWs. During propagation of an SIW over a dielectric surface, the plasma charges the surface while responding to changes in geometrical and electrical material properties. This is particularly important for non-planar surfaces where polarization of the dielectric results in local electric field enhancement. In this paper, we discuss results from computational investigations of negative and positive SIWs propagating over nonplanar dielectrics in three configurations—wavy surfaces, cuts through porous materials and water droplets on flat surfaces. We found that negative SIWs are particularly sensitive to the electric field enhancement that occurs at the crests of non-planar surfaces. The local increase in ionization rates by the electric field enhancement can result in the SIW detaching from the surface, which produces non-uniform plasma exposure of the surface. Positive SIWs tend to adhere to the surface to a greater degree. These trends indicate that treatment of pathogen containing droplets on surfaces may be best performed by positive SIWs. The same principles apply to the surfaces cut through pores. Buried pores with small openings to the SIW may be filled by plasma by either flow of plasma into the pore (large opening) or initiated by photoionization (small opening), depending on the size of the opening compared to the Debye length.
Improved breakdown characteristic of AlGaN/GaN HEMTs with a width gradient recessed dual-gate structure
Authors: Zhang Sheng , Wei Ke , Zhang Yi-chuan , Chen Xiao-juan , Liu Xin-Yu , Niu Jie-bin 
Published: October 2022

Abstract
A dual-gate (DG) structure utilizing an integrated width gradient DC gate to balance the high-voltage and output current drop was performed for the fabrication of AlGaN/GaN high-electron-mobility transistor (HEMT). In comparison to the traditional single-gate devices, the DG HEMTs combine significantly allowable breakdown voltage behaviour with low gate leakage current and a positive shift threshold voltage, delivering one order of magnitude reduction in leakage current and a 36% improvement in maximum drain bias. The evaluated S parameters substantially exhibit a high power gain potential for DG devices due to the presence of DC gate.
Thermally-induced qubit coherence in quantum electromechanics
Authors: Abari N Etehadi , Rakhubovsky A A , Filip R 
Published: October 2022

Abstract
Quantum coherence, the ability of a quantum system to be in a superposition of orthogonal quantum states, is a distinct feature of the quantum mechanics, thus marking a deviation from classical physics. Coherence finds its applications in quantum sensing and metrology, quantum thermodynamics and computation. A particularly interesting is the possibility to observe coherence arising in counter-intuitive way from thermal energy that is without implementation of intricate protocols involving coherent driving sequences. In this manuscript, we investigate quantum coherence emerging in a hybrid system composed of a two-level system (qubit) and a thermal quantum harmonic oscillator (a material mechanical oscillator), inspired by recent experimental progress in fabrication of such systems. We show that quantum coherence is created in such a composite system solely from the interaction of the parts and persists under relevant damping. Implementation of such scheme will demonstrate previously unobserved mechanisms of coherence generation and can be beneficial for hybrid quantum technologies with mechanical oscillators and qubits.
Special exceptional point acting as Dirac point in one dimensional

PT

-symmetric photonic crystal
Authors: Wang Tiecheng 
Published: October 2022

Abstract
We reveal that a special exceptional point (EP) can act as a Dirac point in a one-dimensional

P
T

-symmetric photonic crystal and prove it in detail using our extended first-principle theory. This theory was developed by applying biorthogonal bases of the non-Hermitian Hamiltonian to the

k

→

⋅

p

→

method to study the dispersion relations of non-Hermitian systems. By using this theory, we demonstrate that two linear dispersions can cross at a critical touching point, which is a special EP, and the corresponding effective Hamiltonian can be cast into a massless Dirac Hamiltonian under the biorthogonal bases of the non-Hermitian Hamiltonian; therefore, this point can be called the Dirac point, and the linear slope can also be predicted. In contrast to the Dirac point in a Hermitian system, which is induced by the degeneracy of two different eigenstates, the Dirac point here is induced by the degeneracy of parallel eigenstates in a non-Hermitian system. In addition, after increasing the non-Hermiticity, the Dirac point evolves into a pair of EPs, and their positions in the band structure can be predicted well by our theory. Our findings and theory are important for further understanding the physics of the Dirac point in non-Hermitian wave systems.
Observational constraints on anisotropies for bouncing alternatives to inflation
Authors: Agullo Ivan , Olmedo Javier , Wilson-Ewing Edward 
Published: October 2022

Abstract
We calculate how primordial anisotropies in the background space-time affect the evolution of cosmological perturbations for bouncing alternatives to inflation, like ekpyrosis and the matter bounce scenario. We find that the leading order effect of anisotropies in the contracting phase of the universe is to induce anisotropies in the cosmic microwave background with a very concrete form: a scale-invariant quadrupolar angular distribution. Sub-leading effects are the generation of higher-order moments in the angular distribution, as well as cross-correlations between scalar and tensor modes. We also find that observational constraints from the cosmic microwave background on the quadrupole moment provide strong bounds on allowed anisotropies for bouncing alternatives to inflation that are significantly more constraining than the bounds previously obtained using scaling arguments based on the conjectured Belinski-Khalatnikov-Lifshitz instability.
Analysis of the interaction between the ϕ meson and nucleus
*
Authors: Wang 王 Xiao-Yun 晓云 , Dong 董 Chen 晨 , Wang 王 Quanjin 全进 
Published: October 2022

Abstract
In this study, we systematically investigate the ϕ meson and nucleus interaction by analyzing and fitting the cross sections of
\begin{document}$ \gamma N $\end{document}

\begin{document}$ \rightarrow \phi $\end{document}

N reactions near the threshold, where N represents the nucleus. Using the vector meson dominant model, the distribution of the ϕ-N scattering length is presented as a function of energy, and the results show that there is a slight increase in scattering length with increasing energy. Based on this, the average scattering length of a ϕ-proton is obtained as
\begin{document}$ 0.10\pm0.01 $\end{document}
fm by combining experimental data and theoretical models. Moreover, the average scattering length of the ϕ-deuteron interaction is derived to be
\begin{document}$ 0.014\pm0.002 $\end{document}
fm for the first time. Furthermore, the effect of the momentum transfer
\begin{document}$|t_{{\rm min}}|$\end{document}
on the ϕ-N scattering length at the threshold is discussed. The obtained results not only provide important theoretical information for a more comprehensive and accurate study of the ϕ-N scattering length, but also a basis for future experimental measurements of ϕ meson production.
An Analytical quasi 2D steady-state Francis turbine model using first principles
Authors: Storli P-T , Trivedi C 
Published: October 2022

Abstract
Accurate models are required for obtaining accurate simulation results. High fidelity numerical models exist, but for the simulations of large hydropower conduit systems one-dimensional (1D) models are still required. For the operation and characteristics of hydraulic machinery the state variables in 1D pipe computation are not necessarily providing sufficient level of detail on what happens inside the machine to accurately predict component and system behaviour. This work is looking into the physics of the spatial distribution of the flow at the outlet of a Francis turbine runner in order to include 2D effects into a 1D analysis. The key finding is a differential equation describing the distribution of the relative velocity W between the flow and the runner outlet, which enables numerical integrating for finding the distribution of W itself, and subsequently the circumferential and meridional components needed to execute the integrals turning the 2D results into functions of the 1D state variables. The presented work is reflecting condition at the best efficiency point, but ongoing work is expanding this to map the entire region of a turbine runner. The approach should be very relevant for future implementations into digitalization schemes such as digital twins
An experimental investigation on the effects of cylindrical rods in a draft tube at part load operation in down-scale turbine
Authors: Shiraghaee S , Sundström J , Raisee M , Cervantes M J 
Published: October 2022

Abstract
The present work examines the effects of the radial protrusion of four cylindrical rods at different lengths within the flow field of a down-scaled turbine draft tube under part-load operating conditions. Four rods were placed on the same plane 90 degrees apart. The protrusion length was varied from zero to approximately 90 % of the draft tube radius. Time-resolved pressure measurements were performed to quantify the effect of the rod protrusion, using two pressure sensors at the same vertical level 180 degrees apart. Such sensor configuration enabled the decomposition of the signals into rotating and plunging components of the rotating vortex rope (RVR). The results show that different levels of mitigation are achieved for the rotating and plunging components depending on the protrusion length. The effects on the plunging component differ from the ones on the rotating component. The RVR plunging pressure pulsations slightly increase with the initial rod protrusion and then significantly drop after a certain length. On the contrary, the rotating component of the pressure pulsation amplitudes immediately decreases with the onset of rod protrusion. However, an optimum length is obtained in both cases where the highest mitigation occurs before reaching the maximum protrusion. This observation falls in line with the previous investigations conducted for oscillatory rod protrusions, further approving the point that a closed-loop controller should accompany the mitigation technique to achieve optimum mitigation.
Characterization of no-load conditions for a high head Francis turbine based on the swirl level
Authors: Fortin M , Nennemann B , Houde S 
Published: October 2022

Abstract
This paper compares the average flow topology in the draft tube cone of a high head Francis turbine operated at full-gate opening no-load (runaway) and speed-no-load (SNL). The comparison is based on the swirl level in the turbine quantified with the angular momentum parameter (RCu11) and the Swirl number. This study shows that RCu11 only depends on the flow angle at the guide vane outlet, the distributor height and the runner outlet diameter. The Swirl number has strong limitations in characterizing the flow at runaway and SNL and is unsuitable for no-load conditions.
Development of a test rig for investigating the performance of a model Francis turbine
Authors: Lama R , Gautam S , Lama L , Neopane H P , Chitrakar S 
Published: October 2022

Abstract
Sediments flowing with water in the Himalayan Rivers of Nepal erodes the components of the turbine heavily. The design of hydraulic turbines prioritizes the hydraulic performance of the turbine, neglecting erosion challenges. The necessity of turbine design and its model testing has been felt in the past two decades in Nepal. An attempt is made to fill such conditions by developing a test rig for testing the 92 kW model Francis turbine at Turbine Testing Lab, Kathmandu University, Nepal. The model turbine is a scaled-down model of a 4.1 MW Francis turbine of a Jhimruk Hydropower Plant in Nepal severely affected by sediment erosion. The design of the prototype turbine was carried out considering the hydraulic performance as well as erosion resistivity. The prototype turbine was scaled-down utilising model similarity conditions to meet the lab’s specifications. Each component of the rig has been optimized using CFD to match the lab’s specifications. Comparing the results from CFD and experiment on velocity, pressure, torque, and RPM measurements were comparable.