Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of Different Rewinding Configurations of Five-phase Synchronous Reluctance Machines

In the recent literature, a rewinding approach was proposed to construct a rewound five-phase machine with either star-connected or combined star-pentagon configuration using the existing three-phase stators. For the same rated power of the machine, the power per phase decreases by a factor 3/5 in the five-phase machine, compared to the three-phase machine. This means either the rated current or the rated voltage must be rescaled. The constant current - reduced voltage option enables using only one DC-link capacitor compared to two capacitors in constant voltage - reduced current which enhances system reliability. The two options are investigated in this paper. Moreover, the rewinding method suggested that the number of turns is equally divided between the star and the pentagon coil. To give a detailed proof for this condition, various configurations are compared in term of the magnitude and the harmonics of the magneto-motive force. Finally, simulation and experimental results is introduced.
THE METALLICITY SPREAD AND THE AGE–METALLICITY RELATION OF ω CENTAURI

ω Centauri is a peculiar globular cluster formed by a complex stellar population. To investigate it, we studied 172 stars belonging to the five SGBs that we can identify in our photometry, in order to measure their [Fe/H] content as well as estimate their age dispersion and the age–metallicity relation. The first important result is that all of these SGBs have a distribution in metallicity with a spread that exceeds the observational errors and typically displays several peaks that indicate the presence of several subpopulations. We were able to identify at least six of them based on their mean [Fe/H] content. These metallicity-based subpopulations are seen to varying extents in each of the five SGBs. Taking advantage of the age sensitivity of the SGB, we showed that, first of all, at least half of the subpopulations have an age spread of at least 2 Gyr. Then, we obtained an age–metallicity relation that is the most complete to date for this cluster. Interpretation of the age–metallicity relation is not straightforward, but it is possible that the cluster (or what we can call its progenitor) was initially composed of two populations with different metallicities. Because of their age, it is very unlikely that the most metal-rich derives from the most metal-poor by some kind of chemical evolution process, so they can be assumed to be two independent primordial objects, or perhaps two separate parts of a single larger object, that merged in the past to form the present-day cluster.
Investigation of the Influence of Harmonics on Iron Loss of Soft Magnetic Composites

Increase of power density and efficiency improvement in electric motors are required due to expanding electrification of automotive applications. We have developed soft magnetic composites (SMCs) with high magnetic flux density and low iron loss. To improve efficiency of electric motors, it is necessary to suppress increase of iron loss due to harmonics associated with inverters. It is expected that SMCs with low iron loss at high frequency can reduce the increase of iron loss by harmonics. In this study, the iron losses of SMC and laminated steel sheet (LSS) were measured under PWM and excitations and compared. SMC shows less increase. Moreover, hysteresis loop of SMC under DC superimposition is less distorted compared to LSS. From these results, it is presumed that the SMC’s feature of small iron loss increase under DC superimposition also contributes to suppress the increase of iron loss by harmonics.
Recurrent Neural Network based Prediction of Transition to Mild Cognitive Impairment Using Unobtrusive Sensor Data

Alzheimer’s disease (AD) is the most common neurodegenerative disease among older adults. Mild Cognitive Impairment (MCI) is a transitional stage where older adults begin to exhibit symptoms that could be precursors to AD progression. Detecting the MCI stage early can help prevent or delay the onset of an advanced stage in AD and thus enhance the quality of life among older adults. This neurodegeneration process resonates with the inherent temporal nature of this disease progression. Patterns/trends in daily activities/routine measured over time are better indicators of the disease progression and help detect the transitional stage, MCI. This paper aims to leverage the activity patterns derived through unobtrusive sensors at historical time points and investigate the effect of these activity trends in predicting the progression at a future time point. This study proposes a prediction model leveraging Long short-term memory recurrent neural networks (RNN). From the daily activity/routine standpoint, walk and sleep-related measures are used as input features to the model along with the diagnostic label derived from neuropsychological assessment data, and the transition to MCI is predicted at a future time point. The initial experiment and results show that the study approach proposed in this paper can predict the progression yielding an 82 percent overall prediction accuracy and 90 percent accuracy in predicting degenerating cases. These results encourage future experiments with other extended activity features and further fine-tuned RNN model.
Universe out of a breathing bubble

We consider the model of a false-vacuum bubble with a thin wall where the surface energy density is composed of two different components, 'domain-wall' type and 'dust' type, with opposite signs. We find stably oscillating solutions, which we call 'breathing bubbles'. By decay to a lower mass state, such a breathing bubble could become either (i) a child universe or ii) a bubble that 'eats up' the original universe, depending on the sign of the surface energy of the domain-wall component. We also discuss the effect of the finite-thickness corrections to the thin-wall approximation and possible origins of the energy contents of our model.
Joint Localization and Calibration in Partly and Fully Uncalibrated Array Sensor Networks

The performance of high-resolution direction finding methods can significantly degrade if mismatches between the actual array response and the modeled array response are not compensated. Using sources of opportunity, self-calibration techniques jointly estimate any unknown perturbations and source parameters. In this work, we propose a self-calibration method for sensor networks that fully exploits the source position by combining the well-known bearings-only localization method and existing eigenstructure based self-calibration techniques. Using numerical experiments we demonstrate that the proposed method can uniquely estimate the gain and phase perturbations of multiple sensors as well as the positions of a moving source. We outline the Cramer-Rao lower bound and´ show that the method is efficient. Finally, the self-calibration method is applied to measurement data collected in field trials.
HIGH ANGULAR RESOLUTION OBSERVATIONS OF FOUR CANDIDATE BLAST HIGH-MASS STARLESS CORES

We discuss high angular resolution observations of ammonia toward four candidate high-mass starless cores (HMSCs). The cores were identified by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) during its 2005 survey of the Vulpecula region where 60 compact sources were detected simultaneously at 250, 350, and 500 μm. Four of these cores, with no IRAS–PSC or MSX counterparts, were mapped with the NRAO Very Large Array and observed with the Effelsberg 100 m telescope in the NH3(1,1) and (2,2) spectral lines. Our observations indicate that the four cores are cold (Tk < 16 K) and show a filamentary and/or clumpy structure. They also show a significant velocity substructure within ∼1 km s−1. The four BLAST cores appear to be colder and more quiescent than other previously observed HMSC candidates, suggesting an earlier stage of evolution.
On the Correlation Between Near-Field Scan Immunity and Radiated Immunity at Printed Circuit Board Level – Part II

The work presented in this two-part paper focuses on a prediction method of the radiated susceptibility of integrated circuit and printed circuit board from near-field scan injection, in order to anticipate risks of noncompliance due to design weakness. In Part I, a worst-case estimator of the far-field induced voltage on a PCB trace was proposed. Based on it, an estimator of the radiated susceptibility of a printed circuit board based on near-field scan results is derived and validated through two validation case studies.
Evaluating the Operational Feasibility of Using Subsets of Items to Recommend Minimal Competency Cut Scores

Establishing cut scores using the Angoff method requires panelists to evaluate every item on a test and make a probability judgment. This can be time-consuming when there are large numbers of items on the test. Previous research using resampling studies suggest that it is possible to recommend stable Angoff-based cut score estimates using a content-stratified subset of ˜45 items. Recommendations from earlier work were directly applied in this study in two operational standard-setting meetings. Angoff cut scores from two panels of raters were collected at each study, wherein one panel established the cut score based on the entire test, and another comparable panel first used a proportionally stratified subset of 45 items, and subsequently used the entire test in recommending the cut scores. The cut scores recommended for the subset of items were compared to the cut scores recommended based on the entire test for the same panel, and a comparable independent panel. Results from both studies suggest that cut scores recommended using a subset of items are comparable (i.e., within one standard error) to the cut score estimates from the full test.
Modeling shoulder ligament contributions and their effects on muscle force predictions

Shoulder injuries are a common occurrence in both the workplace and everyday life. Mathematical musculoskeletal modeling and simulation provide a means for proactive injury prevention. To be effective, these models must physiologically replicate shoulder function. Although several muscle force prediction (MFP) shoulder models exist, few have attempted to integrate the force contributions of ligaments. In particular, no existing shoulder models have reported inclusion of the contributions of the glenohumeral ligaments. The purpose of the current study was to integrate seven shoulder ligaments into an existing computational shoulder model, and analyze both individual ligament characteristics and the influence that their inclusion has on the model outputs. Using data from the literature, seven shoulder ligaments were integrated into a computational shoulder model: the costoclavicular, conoid, trapezoid, coracohumeral, superior glenohumeral, middle glenohumeral, and inferior glenohumeral, Ten subjects performed isometric exertions in 56 posture-force combinations. Upper body posture and hand force from these trials were used as inputs for three different model versions of increasing complexity; NoLigaments (NL) included, Glenohumeral-Ligaments (GH) included, and AllLigaments (AL) included. Electromyographic (EMG) signals from 11 muscle sites were recorded and used for comparison with model MFPs. The primary analysis focused on the differences between the GH and NL versions. Normalized EMG amplitudes were plotted against normalized MFPs from both
Stator Faults Diagnostics, under Unbalanced Supply Voltage Conditions, in Symmetrical Six-phase Induction Motors Fed by a Three-phase System

This paper addresses the diagnostics of inter-turn short-circuits in the stator windings of symmetrical six-phase induction motors supplied by an unbalanced voltage three-phase system. A new approach based on the analysis of the power zero-sequence component is proposed. Both simulation and experimental results are presented, that show the effectiveness of the proposed approach for discriminating between healthy and faulty motor operation, independently of the balanced/unbalanced nature of the supply voltage system.
Aspects of general higher-order gravities

We study several aspects of higher-order gravities constructed from general contractions of the Riemann tensor and the metric in arbitrary dimensions. First, we use the fast-linearization procedure presented in [P. Bueno and P. A. Cano, arXiv:1607.06463] to obtain the equations satisfied by the metric perturbation modes on a maximally symmetric background in the presence of matter and to classify L(Riemann) theories according to their spectrum. Then, we linearize all theories up to quartic order in curvature and use this result to construct quartic versions of Einsteinian cubic gravity. In addition, we show that the most general cubic gravity constructed in a dimension-independent way and which does not propagate the ghostlike spin-2 mode (but can propagate the scalar) is a linear combination of f(Lovelock) invariants, plus the Einsteinian cubic gravity term, plus a new ghost-free gravity term. Next, we construct the generalized Newton potential and the post-Newtonian parameter γ for general L(Riemann) gravities in arbitrary dimensions, unveiling some interesting differences with respect to the four-dimensional case. We also study the emission and propagation of gravitational radiation from sources for these theories in four dimensions, providing a generalized formula for the power emitted. Finally, we review Wald’s formalism for general L(Riemann) theories and construct new explicit expressions for the relevant quantities involved. Many examples illustrate our calculations.
Using Math Vocabulary Building to Increase Problem Solving Abilities in a 5th Grade Classroom

In this action research study of my 5 grade mathematics class, I investigated how students’ understanding of math vocabulary impacts their understanding of the curriculum. I discovered math vocabulary plays an important role in a student’s ability to understand daily lessons, complete homework, discuss ideas in groups, take tests and be successful on achievement tests. A student’s ability to understand the words around him (or her) in math class seem very related to his or her ability to solve word problems. Word problems are what our national assessments are all about. I also discovered that direct instruction and support of math vocabulary increased test scores and confidence in students as test takers. As a result of this research, I plan to continue to find ways to emphasize the vocabulary used in our current math curriculum. This process will start at the beginning of the year. I will continue to look for strategies that promote math vocabulary retention in my students. And finally, I will share my findings with my colleagues, so my research can be used as part of our School Improvement Goals. Julane Amen Math in the Middle Institute Partnership Heaton/Action Research Project June 5, 2006
Investigation of Material Combinations for Axially-Laminated Synchronous Machine

High-speed electric machines are special types of electric machines which aim for compact, direct-driven high-speed applications and highly efficient operation, especially, when gearbox can be avoided. Design of these types of machines is highly iterative combining multiphysics optimization and leads to custom types of machines which fulfill the application-specific requirements. Synchronous Reluctance Machines (Syn-RMs) might have an axially-laminated solid rotor structure, which combines magnetic and non-magnetic layers rigidly bonded to each other by vacuum brazing, hot isostatic pressing, soldering, explosion welding or even by additive manufacturing. In the study five non-magnetic materials and nine magnetic materials are cross compared and the results show clear differences in performance, efficiency and physical properties of the rotor when made of different material combinations, and thereby can suggest the best pairs when application-specific performance criteria are known. The study is carried out on a 12 kW machine with a maximum speed of 24000 rpm.
On the Mitigation of Leakage Flux in Spoke Type Permanent Magnet Synchronous Machines

The use of rare-earth elements in permanent magnets rises economic, environmental and supply-chain related concerns. Instead, ferrite magnets have been researched as an alternative. The magnetic flux concentration capacity of the Spoke Type Permanent Magnet Synchronous Motor (PMSM) and the low magnetic remanence of the ferrite magnet make them complementary strategies towards the desirable performance. However, if restricted to conventional manufacturing processes and materials, the mechanical design is a challenging step of the development of these machines. This paper explores how mechanical constraints impact electromagnetic performance. To access the interdependency of the performance and the mechanical constraints, finite element analyses are done both in the mechanical and electromagnetic domain. The results show that the mechanical constraints have an impact on the performance, although it is possible to reduce it by adapting the design to the electromagnetic and mechanical properties of the electrical steel.
Differential Expression of α-Enolase in Clinical Gastric Tissues and Cultured Normal/Cancer Cells in Response to Helicobacter pylori Infection and cagA Transfection

Background and Objectives: The role of α-enolase (ENO1) in Helicobacter pylori-related gastric lesions might be a critical factor in the pathogenesis, but remains undefined. Materials and Methods: This study investigated the differential expression of α-enolase in clinical gastric specimens and cultured normal/cancer cells in response to H. pylori (cagA+) infection and cagA transfection using qPCR, Western blots and histochemical methods. Results: A total of 172 gastric specimens were collected from 142 patients, the former comprising chronic superficial gastritis (CSG), precancerous diseases (PCDs, including atrophic gastritis, intestinal metaplasia and dysplasia) and gastric cancer (GC) cases. Among the CSG and PCD cases, the H. pylori-infected group had significantly elevated ENO1 mRNA levels compared with the uninfected group. In the GC cases, differential ENO1 expressions were detected between the cancer tissues and the paracancerous tissues. Notably, significant difference was first detected between the GC cell (AGS) and the normal cell (GES-1) as a response of ENO1 to H. pylori infection and cagA transfection. Conclusions: This report reveals that ENO1 expression is associated with H. pylori infection, cagA transfection, co-culture duration, multiplicity of infection, gastric normal/cancerous cell lines and cellular differentiation. The findings may be crucial bases for further ascertaining H. pylori pathogenic mechanism and formulating novel therapeutic and diagnostic strategies.
The Π-Theorem as a Guide to Quantity Symmetries and the Argument Against Absolutism *

In this paper a symmetry argument against quantity absolutism is amended. Rather than arguing against the fundamentality of intrinsic quantities on the basis of transformations of basic quantities, e.g. mass doubling, a class of symmetries defined by the Π-theorem are used. This theorem is a fundamental result of dimensional analysis and shows that all unit-invariant equations which adequately represent physical systems can be put into the form of a function of dimensionless quantities. Quantity transformations that leave those dimensionless quantities invariant are empirical and dynamical symmetries. The proposed symmetries of the original argument fail to be both dynamical and empirical symmetries and are open to counterexamples. The amendment of the original argument requires consideration of the relationships between quantity dimensions, particularly the constraint of dimensional homogeneity on our physical equations. The discussion raises a pertinent issue: what is the modal status of the constants of nature which figure in the laws? Two positions, constant necessitism and constant contingentism, are introduced and their relationships to absolutism and comparativism undergo preliminary investigation. It is argued that the absolutist can only reject the amended symmetry argument by accepting constant necessitism, which has a costly outcome: unit transformations are no longer symmetries.
Defending against Cross-Technology Jamming in Heterogeneous IoT Systems

The wide deployment of IoT devices has resulted in a critical shortage of spectrum resources. Many IoT devices coexist on the same spectrum band, where the network performance is always degraded. As a promising solution, the Cross-Technology Communication (CTC) enables the direct communication among heterogeneous IoT devices. Unfortunately, the emerging cross-technology attacks have demonstrated their high success rates in terms of spoofing the end IoT devices or jamming the communication channels. In this paper, we investigate a novel cross-technology jamming issue for a distributed heterogeneous IoT system. Compared with traditional jamming methods, the cross-technology jammer has a much higher jamming power, wider jamming bandwidth, and stronger stealthiness, all of which deserve a complete re-thinking of defensive mechanisms. Therefore, we propose a hybrid anti-jamming scheme that jointly considers frequency hopping and power control techniques. Specifically, we model the anti-jamming process as a Markov Decision Process (MDP) and adopt Deep Q-Network (DQN) to find the optimal strategy. Extensive real-world experiments show that the goodput (payload data) of our anti-jamming scheme can achieve up to 2X and 1.39X than the passive and random anti-jamming approaches, respectively. In particular, our anti-jamming scheme provides 78% of goodput with the presence of a cross-technology jammer, outperforming existing passive and random anti-jamming scheme designs at 37.6% and 54.1%.
More Tales of Hoffman: Bounds for the Vector Chromatic Number of a Graph

Abstract Let χ(G) denote the chromatic number of a graph and χv(G) denote the vector chromatic number. For all graphs χv(G) ≤ χ(G) and for some graphs χv(G) ≪ χ(G). Galtman proved that Hoffman’s well-known lower bound for χ(G) is in fact a lower bound for χv(G). We prove that two more spectral lower bounds for χ(G) are also lower bounds for χv(G). We then use one of these bounds to derive a new characterization of χv(G).
More than meets the eye: magnetars in disguise

It has recently been proposed that radio emission from magnetars can be evaluated using a ‘fundamental plane’ in parameter space between pulsar voltage gap and ratio of X-ray luminosity L_x to rotational energy loss rate Edot. In particular, radio emission from magnetars will occur if L_x/Edot 1. Here we clarify several issues regarding this fundamental plane, including demonstrating that the fundamental plane is not uniquely defined. We also show that, if magnetars and all other pulsars are different manifestations of a unified picture of neutron stars, then pulsar radio activity (inactivity) appears to be determined by the ratio L_x/Edot ~ 1), although observational bias and uncertainty in the ratio for some sources may still invalidate this conclusion. Finally, we comment on the use of other pulsar parameters that are constructed from the three observables: spin period, P, period derivative, Pdot, and L_x.