Miracle-dz/UniFAR-FTUs huggingface dataset:
Resonant Switching Cell Model for High-Frequency Single-Ended Resonant Converters

This paper proposes a resonant switching cell model to analyze and design the single-ended resonant dc–dc converters. The single-ended zero-voltage switching (ZVS) converters such as the Class E converter are efficient for megahertz switching because they feature low turn-on and turn-off switching losses. Also, they use only a ground-referenced switch, allowing a simple gate drive circuit. In this paper, we investigate the single-ended resonant converter with the small input inductance, whereas the conventional Class E converter has a large input inductance. The main contribution of this paper is to propose the resonant switching cell as an analytic model that simplifies the analysis and the design of the resonant dc–dc converters. Furthermore, this paper presents the design method of the resonant switching cell model for minimizing the resonant current magnitude and conduction loss while the converter maintains ZVS property. The experimental results from a 10-MHz GaN-based prototype demonstrate the feasibility and effectiveness of the analysis and design based on the proposed resonant switching cell model.
Precision measurements, dark matter direct detection and LHC Higgs searches in a constrained NMSSM

We reexamine the constrained version of the Next-to-Minimal Supersymmetric Standard Model with semi universal parameters at the GUT scale (CNMSSM). We include constraints from collider searches for Higgs and susy particles, upper bound on the relic density of dark matter, measurements of the muon anomalous magnetic moment and of B-physics observables as well as direct searches for dark matter. We then study the prospects for direct detection of dark matter in large scale detectors and comment on the prospects for discovery of heavy Higgs states at the LHC.
Non‐isolated high step‐up three‐port converter with single magnetic element for photovoltaic systems

A new non-isolated high-voltage gain three-port converter for standalone photovoltaic systems is proposed. The magnetic element of this converter is only one coupled inductor. The primary winding of the coupled inductor is shared between battery charger circuit and main converter. Leakage inductance energy of the coupled inductor is either transferred to battery or is regenerated via the passive-clamp circuit. Using switched capacitor and voltage lift techniques, the voltage gain is significantly increased for both low-voltage ports. Single magnetic element, high-voltage gain with reasonable duty cycle, low-voltage stress on the switches, low winding turn ratio of coupled inductor and high efficiency are the merits of this converter. The operation principles and the steady-state analysis are described for the three modes of: single-input single-output, single-input dual-output and dual-input single-output. To verify the theoretical analysis, a laboratory prototype with 28 V input, 48 V battery voltage and 380 V output voltage is implemented and tested.
A miniaturized ultrawideband Archimedean spiral antenna for low‐power sensor applications in energy harvesting

This work presents the design, manufacturing, and measurement of a miniaturized circularly polarized ultrawideband Archimedean spiral antenna that operates from 0.3 GHz to 16 GHz. It acts as a radiofrequency harvester, capturing the energy spectrum in the bands of interest (FM, DTT, LTE‐800, GSM‐900, GSM‐1800, LTE‐2100, WiFi, LTE‐2600 and WiMAX). A prototype of the Archimedean spiral has been manufactured and characterized in the laboratory, and a comparison of the harvested power with respect to other also manufactured baseline 2.4 GHz patch antennas has been carried out in two different locations: inside and outside the laboratory. These results prove that hundreds of microwatts can be acquired in a normal situation, without the spiral pointing directly at a prefixed source.
Spatio-Temporal Hedonic Price Model to Investigate the Dynamics of Housing Prices in Contexts of Urban Form and Transportation Services in Toronto

A spatio-temporal hedonic price model is developed for the Greater Toronto area to examine the effects of urban configurations and proximity to transit services on housing price. A spatial Durbin panel model is utilized to account for both spatial and temporal autocorrelation. This model is shown to have advantages through its ability to reduce the number of explanatory variables required to obtain a strong fit with empirical data. Analysis is completed for the period of 1996 to 2017 and distinctions are made in housing stock between single-family houses, townhouses, and condominiums. It is shown that heterogeneities exist between the hedonic representations of each dwelling type and that separate models should be employed for each. In all cases, the average income of the community, its distance to the central business district (CBD), and population and employment density are found to be significant factors in the determination of price.
Late time cosmic acceleration from vacuum Brans–Dicke theory in 5D

We show that the scalar-vacuum Brans–Dicke equations in 5D are equivalent to Brans–Dicke theory in 4D with a self-interacting potential and an effective matter field. The cosmological implication, in the context of FRW models, is that the observed accelerated expansion of the universe comes naturally from the condition that the scalar field is not a ghost, i.e. ω > −3/2. We find an effective matter-dominated 4D universe which shows accelerated expansion if −3/2 < ω < −1. We study the question of whether accelerated expansion can be made compatible with large values of ω, within the framework of a 5D scalar-vacuum Brans–Dicke theory with variable, instead of constant, parameter ω. In this framework, and based on a general class of solutions of the field equations, we demonstrate that accelerated expansion is incompatible with large values of ω.
A 60 Joule, 600 kV, 500 ps risetime, 60 ns pulse width Marx generator

The experimental and computer modelling of the performance of a 24-stage coaxial line Marx generator are presented. Internal inductance, stray capacitance, coupling capacitance between the stages and switch characteristic are considered. The detailed geometry of each stage and of the total system is included in the computer simulation. The UV pre-ionized spark gaps forming the switches in the system are characterized by the spark overvoltage. The transmission line effects are also observed. The output characteristics are given at different overvoltages.
Study of structure, transport, paramagnetic and ferromagnetic properties of La0.8Sr0.2Mn1−xZnxO3 perovskite manganite

La0.8Sr0. 2Mn1−xZnxO3 perovskite manganite with x = 0, 0.01, 0.03, 0.05, 0.1, 0.15, 0.3, 0.5 and 0.75 has been prepared by the solid state reaction and investigated by structural, transport and magnetic measurements. The structural characterization of the samples has been done by x-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The x-ray powder diffraction results indicate a single phase for 0 < x < 0.5, confirming that zinc is incorporated on the Mn site. The lattice parameters (a, b, c) of this orthorhombic system increase with increasing zinc concentration in the system. According to the SEM images, the grain size of the materials with x > 0.1 decreases with increasing zinc doping levels. The transport measurements show that the insulator-to-metal transition temperature, Tc, decreases with increasing zinc substitution on the Mn site, and the resistivity increases. The Tc variations agree with the magnetic measurement data for x < 0.3. The compound changes from ferromagnetic to paramagnetic for x > 0.3. The possible mechanism behind the effects of zinc doping into the La0.8Sr0. 2Mn1−xZnxO3 system involves degradation of the double exchange between Mn3+–O–Mn4+ in this compound.
Modelling coupled physical-biogeochemical processes in ice-covered oceans

The last decades have seen a large effort of the scientific community to study and understand the physics of sea ice. We currently have a wide - even though still not exhaustive - knowledge of the sea ice dynamics and thermodynamics and of their temporal and spatial variability. Sea ice biogeochemistry is instead largely unknown. Sea ice algae production may account for up to 25% of overall primary production in ice-covered waters of the Southern Ocean. However, the influence of physical factors, such as the location of ice formation, the role of snow cover and light availability on sea ice primary production is poorly understood. There are only sparse localized observations and little knowledge of the functioning of sea ice biogeochemistry at larger scales. Modelling becomes then an auxiliary tool to help qualifying and quantifying the role of sea ice biogeochemistry in the ocean dynamics. In this thesis, a novel approach is used for the modelling and coupling of sea ice biogeochemistry - and in particular its primary production - to sea ice physics. Previous attempts were based on the coupling of rather complex sea ice physical models to empirical or relatively simple biological or biogeochemical models. The focus is moved here to a more biologically-oriented point of view. A simple, however comprehensive, physical model of the sea ice thermodynamics (ESIM) was developed and coupled to a novel sea ice implementation (BFM-SI) of the Biogeochemical Flux Model (BFM). The BFM is a comprehensive model, largely used and validated in the open ocean environment and in regional seas. The physical model has been developed having in mind the biogeochemical properties of sea ice and the physical inputs required to model sea ice biogeochemistry. The central concept of the coupling is the modelling of the Biologically-Active-Layer (BAL), which is the time-varying fraction of sea ice that is continuously connected to the ocean via brines pockets and channels and it acts as rich habitat for many microorganisms. The physical model provides the key physical properties of the BAL (e.g., brines volume, temperature and salinity), and the BFM-SI simulates the physiological and ecological response of the biological community to the physical enviroment. The new biogeochemical model is also coupled to the pelagic BFM through the exchange of organic and inorganic matter at the boundaries between the two systems . This is done by computing the entrapment of matter and gases when sea ice grows and release to the ocean when sea ice melts to ensure mass conservation. The model was tested in different ice-covered regions of the world ocean to test the generality of the parameterizations. The focus was particularly on the regions of landfast ice, where primary production is generally large. The implementation of the BFM in sea ice and the coupling structure in General Circulation Models will add a new component to the latters (and in general to Earth System Models), which will be able to provide adequate estimate of the role and importance of sea ice biogeochemistry in the global carbon cycle.
High-transparency infrared materials.

The period 1970-1975 has been one of unusual activity in the field of infrared materials. Driven primarily by the need for highly transparent lens and window elements in high power laser optics, significant advances have been made in the quality, physical strength and size of a variety of materials and in particular the alkali halides, alkaline earth fluorides, zinc selenide, and for use in fiber optics, fused silica. The state-of-the-art of these materials is outlined, the basic physical processes that determine their optical and mechanical limits are reviewed, and suggestions are made for future work in electro-optic and magneto-optic materials research.
B-mode detection with an extended planck mission

The Planck satellite has a nominal mission lifetime of 14 months allowing two complete surveys of the sky. Here we investigate the potential of an extended Planck mission of four sky surveys to constrain primordial B-mode anisotropies in the presence of dominant Galactic polarized foreground emission. An extended Planck mission is capable of powerful constraints on primordial B-modes at low multipoles, which cannot be probed by ground based or sub-orbital experiments. A tensor-scalar ratio of r = 0.05 can be detected at a high significance level by an extended Planck mission and it should be possible to set a 95% upper limit of r ≲ 0.03 if the tensor-scalar ratio is vanishingly small. Furthermore, extending the Planck mission to four sky surveys offers better control of polarized Galactic dust emission, since the 217 GHz frequency band can be used as an effective dust template in addition to the 353 GHz channel.
Facilitation of air traffic control via optical character recognition‐based aircraft registration number extraction

To identify any aircraft in the world, it is sufficient to read its registration number. This number is a unique identifier, and offers valuable information, in the same way a car registration number does. In this work, the authors present the results of their feasibility study towards a simple, yet very efficient and effective system to identify aircrafts using video-optical character recognition acquired by off-the-shelf cameras. They used several videos under realistic conditions at the Heraklion airport during high season and they achieved very promising results. They claim that there is much room for the development of a low-cost airport surface monitoring system based on standard cameras, which can complement high-cost radars.
Braneworld instantons

We derive the general equations of motion for a braneworld containing a (localized) domain wall. Euclideanization gives the geometry for braneworld false vacuum decay. We explicitly derive these instantons and compute the amplitude for false vacuum decay. We also show how to construct a toy ekpyrotic instanton. Finally, we comment on braneworlds with a compact spatial direction and the anti-de Sitter soliton.
THE METHOD OF CENTRED SYSTEMS IN THE THEORY OF TOPOLOGICAL SPACES

CONTENTS Introduction § 1. The space of maximal centred systems § 2. θ-continuous mappings. Definition of the absolute § 3. Hausdorff extensions of spaces § 4. The Aleksandrov-Uryson compactness criterion § 5. Perfect mappings and the absolute § 6. The absolute and extensions of spaces References
CLASSIFICATION MODEL AND ANALYSIS ON STUDENTS’ PERFORMANCE

The purpose of this paper is to propose a classification model for classifying students’ performance in SijilPelajaran Malaysia in order to help teachers plan suitable teaching activities for their students based on the students’ performance. Five classifier algorithms have been used during the process which are Naive Bayes, Random Tree, Multi Class Classifier, Conjunctive Rule and Nearest Neighbour. Data was collected from MaktabRendahSains MARA Kuala Berang, Terengganu, Malaysia starting May 2011 until December 2014. The students’ performance was evaluated based on the category of students according to their SPM Results. Parameters that contribute to students’ performance such as stream, state, gender and hometown are also investigated along with the examination data.This research shows that first semester results can be used to identify students’ performance. Keywords : educational data mining; classification model; feature selection
Design and implementation of a high frequency electrical impedance tomography system

Electrical impedance tomography is an imaging modality being investigated for use in detection of breast cancer. Use of higher frequencies than have typically been employed may benefit the detection processes. In this current work we discuss the design and initial implementation of a system having a bandwidth of 10 MHz. Previous investigations into high frequency designs have proven more difficult than anticipated and shown that careful selection of systems architecture is critical to achieving broadband performance above 1 MHz. The design for this new system is based on a digital signal processor (DSP) which is used for control, signal generation and signal processing. Signal generation and detection, software design and preliminary system specifications are discussed.
A left-handed simplicial action for Euclidean general relativity

An action for simplicial Euclidean general relativity involving only left-handed fields is presented. The simplicial theory is shown to converge to continuum general relativity in the Plebanski formulation as the simplicial complex is refined. This contrasts with the Regge model for which Miller and Brewin have shown that the full field equations are much more restrictive than Einstein's in the continuum limit. The action and field equations of the proposed model are also significantly simpler than those of the Regge model when written directly in terms of their fundamental variables. An entirely analogous hypercubic lattice theory, which approximates Plebanski's form of general relativity, is also presented.
MULTI3D: A Domain-Decomposed 3D Radiative Transfer Code

We present MULTI3D, a 3D radiative transfer code currently under development. It is optimized for computing NLTE problems based on (radiation-)MHD models of stellar atmospheres. MULTI3D is based on MULTI and includes most of the physics present in that code. MULTI3D was first written as a serial code by Botnen (1997) and has recently been upgraded to an MPI-parallelized, domain-decomposed version. The code has so far successfully been run on up to 64 processors, solving the NLTE radiative transfer for a sixlevel Ca II atom with 400 frequency points in an atmosphere of 256 x 128 x 108 grid points.
Investigation of Tritron as a high power microwave oscillator

In order to improve the conversion efficiency of the dual cavity oscillator named Bitron, a new type of triple cavity oscillator named Tritron is proposed and investigated in this paper. An intermediate cavity is introduced into the device to enhance the beam modulation depth and the conversion efficiency. The theoretical study shows that the fundamental harmonic current modulation coefficient could exceed 1.16 when the modulated electron beam enters the intermediate cavity at an optimized phase. Accordingly, the maximum theoretical efficiency could exceed the efficiency of the Bitron of 58%. Moreover, an S-band Tritron is designed and verified by the particle-in-cell simulation. An output power of 2.6 GW with a frequency of 2.42 GHz is obtained in the simulation. Compared with the efficiency of 22.2% obtained in the Bitron, the efficiency of the Tritron increases to 41.3%. In order to improve the conversion efficiency of the dual cavity oscillator named Bitron, a new type of triple cavity oscillator named Tritron is proposed and investigated in this paper. An intermediate cavity is introduced into the device to enhance the beam modulation depth and the conversion efficiency. The theoretical study shows that the fundamental harmonic current modulation coefficient could exceed 1.16 when the modulated electron beam enters the intermediate cavity at an optimized phase. Accordingly, the maximum theoretical efficiency could exceed the efficiency of the Bitron of 58%. Moreover, an S-band Tritron is designed and verified by the particle-in-cell simulation. An output power of 2.6 GW with a frequency of 2.42 GHz is obtained in the simulation. Compared with the efficiency of 22.2% obtained in the Bitron, the efficiency of the Tritron increases to 41.3%.
Deterministic and Bayesian Sparse Signal Processing Algorithms for Coherent Multipath Directions-of-Arrival (DOAs) Estimation

In this paper, we propose novel deterministic and Bayesian methods to identify the directions-of-arrival (DOAs) of coherent multipath signals assuming that a very few number of multipath signals are present and multiple snapshots are available. For both types of methods, we exploit both sparsity and the underlying structure of coherent signal propagation. For the deterministic case, we formulate the problem of estimating the DOAs of coherent multipath signals as a biconvex optimization problem and then solve it by an alternating convex search approach. This is in contrast to the widely used $\ell _1$ sparse signal recovery convex optimization problem, which only exploits sparsity of the signal under consideration. For the Bayesian case, we propose two novel algorithms based on the mean field variational Bayesian expectation maximization approach. The first algorithm assumes that the true scenario DOAs of the multipath signals are exactly aligned with the angular grids. We next extend the on-grid model to deal with the off-grid problem, which is the second proposed Bayesian algorithm of this paper. These two Bayesian algorithms are in contrast to the widely used sparse Bayesian learning relevance vector machine algorithm, which only exploits sparsity in spatial domain. A simulation study is carried out in terms of root-mean-squared error in the DOA estimates to compare the performances of different algorithms. Finally, we demonstrate the application of the proposed off-grid Bayesian algorithm by analyzing data from the shallow water HF$\mathbf {97}$ ocean acoustic experiment.
Coupling of tip leakage flow and blade vibration in transonic compressors : mechanism and countermeasures

This dissertation describes the aeroelastic results of a modern 1.5-stage research compressor with blisk rotor. The heavily instrumented compressor is investigated with different tip clearances and advanced casing treatment. In particular, flutter and a self-excited rotating instability are studied. For both phenomena the aeroelastic link establishes at blade tip where a backward traveling aerodynamic wave couples with a forward traveling blade vibration. The crucial role of the blade tip clearance and the flow leaking across blade tip is clearly exhibited. Both gain additional relevance from the observation that a 10% variation in local tip clearance may cause individual blade vibration amplitudes to vary by a factor of two. The non-synchronous vibrations occur for transonic rotor relative inflow as well as in the subsonic part speed region. Circumferential wave speed and wave Mach number of the backward waves are identified as common link between the blade vibration events at different compressor speeds with seemingly arbitrary active nodal diameter. It is further shown that the vibration wave Mach number correlates with the circumferential Mach number of a rotating stall cell at identical speed with nominal VIGV setting. Finally, this dissertation proves that the aeroelastic coupling can be prevented by either a reduction in average tip clearance or by aerodynamic mistuning through advanced casing treatment. The negation of this final conclusion implies that an increase in tip clearance due to transient operation, rub-in or component wear may lead to the onset of blade vibrations not encountered with nominal clearance. The dissertation thus clearly points out that blade vibration analyses have to be robust enough to cover the compressor's entire life cycle.
Smart Building Lighting System

In a building, lighting contributes 20-60% of the total consumption of electrical energy usage. To turn on and off the lamp with the switch manually sometimes people forget to turn it off when leaving the room. This resulted in the inefficiency of energy and cost, where the lamps work not based on need. To overcome this problem designed a lighting control system using internet of things concept so that the lights can be controlled and monitored remotely. This control system is designed using Arduino Mega 2560 as a microcontroller, relays as connectors and electric breakers voltage lamp and motion sensor as a switch that turns off the lights when there is no person in the room and indicator of the activity in the room. In addition, outdoor lights are lit in accordance with a predetermined schedule for more efficient power usage. With lighting control system is expected to reduce consumption of electrical energy usage so more efficient.