Miracle-dz/UniFAR-FTUs huggingface dataset:
Efficient Supply Modulator for Wide-Band Envelope Elimination and Restoration Power Amplifiers

A fast transient response supply modulator has been realized and verified in envelope elimination and restoration (EER) power amplifier. The analysis and detailed design of the proposed architecture is presented. Simulation results, in 130-nm CMOS technology, show that the proposed supply modulator achieves better linearity and efficiency compared to the conventional hybrid mode supply modulators or hybrid EER when signal frequency increases. Adjacent channel leakage ratio requirements are met for an LTE signal with 5 MHz, 10 MHz, and 20 MHz BW with error vector magnitude less than 3% and efficiency of 79%, 73%, and 67%, respectively at an output power of 0.45 W. Post-layout simulations are performed across different process corners and the effects of real off-chip components and routes are taken into consideration to verify the robustness of the proposed solution.
Remarks on existence and uniqueness of solutions of elliptic problems with right-hand side measures

We consider the homogeneous Dirichlet problem −∂xi(aij∂xju) = f in Ω u = 0 on ∂Ω with f ∈ M(Ω), the space of Radon measures and Ω open bounded set of RN . For f 6∈ H−1(Ω), some weak solutions have been introduced : we show that the one of Boccardo-Gallouet and the one of Stampacchia are the same. Then we show, with a counter-example of Serrin that the weak formulation of the first one does not ensure uniqueness.
Measurement of Drilling Fluid Rheology and Modeling of Thixotropic Behavior

Abstract Drilling fluids perform a number of important functions during a drilling operation, including that of lifting drilled cuttings to the surface and balancing formation pressures. Drilling fluids are usually designed to be structured fluids exhibiting shear thinning and yield stress behavior, and most drilling fluids also exhibit thixotropy. Accurate modeling of drilling fluid rheology is necessary for predicting friction pressure losses in the wellbore while circulating, the pump pressure needed to resume circulation after a static period, and how the fluid rheology evolves with time while in static or near-static conditions. Although modeling the flow of thixotropic fluids in realistic geometries is still a formidable future challenge to be solved, considerable insights can still be gained by studying the viscometric flows of such fluids. We report a detailed rheological characterization of a water-based drilling fluid and an invert emulsion oilbased drilling fluid. The micro structure responsible for thixotropy is different in these fluids which results in different thixotropic responses. Measurements are primarily focused at transient responses to step changes in shear rate, but cover also steady state flow curves and stress overshoots during start-up of flow. We analyze the shear rate step change measurements using a structural kinetics thixotropy model.
Hidden conformal symmetry of a massive scalar field in AdS2

We show that a massive scalar field on a two-dimensional anti-de Sitter space (AdS2) can be mapped by means of a time-dependent canonical transformation into a massless free field theory when the mass square of the field is equal to minus the curvature of the background metric. We also provide the (hidden) conformal symmetry of the massive scalar field.
Model Predictive Control for a Six-Phase PMSM With High Robustness Against Weighting Factor Variation

This paper presents a novel model predictive torque control with discrete duty ratio optimization for a six-phase PMSM machine with high robustness against weighting factor variation. First, a two-step lookup table is developed to initially select the optimal voltage vector, which is to regulate the torque and flux in the energy conversion related subspace, as well as suppress the harmonic currents in the x–y subspace. Then, a null vector is inserted along with the selected optimal voltage vector to adjust the duty ratio with a set of value to avoid the complicated derivation. Subsequently, the optimal duty ratio is determined by a cost function to minimize the torque and flux error. So by using the proposed method, the torque ripple is reduced and even applying an improper weighting factor will not deteriorate the machine performance severely. Finally, experimentations are carried out to verify the validity of the proposed method.
Inductance Testing for IPM Synchronous Machines According to the New IEEE Std 1812 and Typical Laboratory Practices

Equivalent circuit parameters serve as the basis for performance estimation and implementation of power electronic drives controls and therefore their accurate evaluation is very important. Specified in the newly approved IEEE Std 1812, a short-circuit test can be employed, in combination with an open-circuit measurement, in order to determine the back emf and the synchronous inductance. In the case of interior permanent magnet (IPM) machines, this approach can be used only to determine the d-axis inductance and additional and separate measurements are required for the q-axis inductance. In this respect, various methods, inclusive of dc step response tests, on-load tests, and a widely used test in industry, which involves locked-rotor measurements at variable voltage and constant frequency supply, are studied in detail, based on two-dimensional finite element analysis. Locked-rotor methods based on dc current supply and static torque versus rotor position measurements are introduced for determining the q-axis inductance in combination with the standardized open-circuit and short-circuit tests. A critical study of the inductances determined from different tests is conducted, and experimental results on an IPM motor design with non-sinusoidal back emf, relatively high torque ripple, and low leakage are presented.
The supernova 1987A in the Large Magellanic Cloud

Two years after the discovery of supernova 1987A in the Large Magellanic Cloud the huge amount of new and exciting information is still being analysed by astronomers and astrophysicists all over the world. The authors try to summarise the present situation concerning both the observational facts and their theoretical interpretation. In particular, they focus their attention on the information contained in the light curve and the spectra, and in the detection of neutrinos. It is shown that many previously open questions have now been answered, but also that many new problems await a solution. These include the unexpected blue appearance of the progenitor star, its presupernova evolution, the explosion mechanism, apparent deviations from spherical symmetry and their origin, properties of matter at high densities and temperatures, etc. All these questions are far from being fully understood. Nevertheless, an attempt is made to give at least some hints on how solutions may be obtained.
Novel radio-frequency-based gas sensor with integrated heater

Abstract. Up to now, sensor applications have rarely used materials whose dielectric properties are a function of the gas concentration. A sensor principle, by which this material effect can be utilized, is based planar radio-frequency sensors. For the first time, such a sensor was equipped with an integrated heater and successfully operated at temperatures up to 700 ∘C. This makes it possible to apply materials that show gas-dependent changes in the dielectric properties only at higher temperatures. By coating the planar resonance structure with a zeolite, ammonia could be detected. The amount of ammonia stored in the sensitive layer can thereby be determined, since the resonant frequency of the sensor shifts with its ammonia loading. Desorption measurements showed a dependence of the storage behavior of the ammonia in the gas-sensitive layer on the operating temperature of the sensor. Thus, it was possible that by operating the sensor at 300 ∘C, it only shows a gas-concentration-dependent signal. At lower operating temperatures, on the other hand, the sensor could possibly be used for dosimetric determination of very low ammonia concentrations.
Physical properties of geometric singularities

We study a class of singularities of prescribed behaviour and investigate physical properties such as their strength, and the validity of energy conditions in a neighbourhood of these singularities. As applications of our theory, we show that shell (crossing) singularities are at variance with a new (but plausible) energy condition. We also show that for perfect fluid shell singularities, the energy density always exists as a spacetime average. In another application we prove that smooth, signature-type changing spacetimes are non-singular at the surface of signature change if the dominant energy condition holds.
Detection and Classification of Overlapping Cell Nuclei in Cytology Effusion Images Using a Double-Strategy Random Forest

Due to the close resemblance between overlapping and cancerous nuclei, the misinterpretation of overlapping nuclei can affect the final decision of cancer cell detection. Thus, it is essential to detect overlapping nuclei and distinguish them from single ones for subsequent quantitative analyses. This paper presents a method for the automated detection and classification of overlapping nuclei from single nuclei appearing in cytology pleural effusion (CPE) images. The proposed system is comprised of three steps: nuclei candidate extraction, dominant feature extraction, and classification of single and overlapping nuclei. A maximum entropy thresholding method complemented by image enhancement and post-processing was employed for nuclei candidate extraction. For feature extraction, a new combination of 16 geometrical and 10 textural features was extracted from each nucleus region. A double-strategy random forest was performed as an ensemble feature selector to select the most relevant features, and an ensemble classifier to differentiate between overlapping nuclei and single ones using selected features. The proposed method was evaluated on 4000 nuclei from CPE images using various performance metrics. The results were 96.6% sensitivity, 98.7% specificity, 92.7% precision, 94.6% F1 score, 98.4% accuracy, 97.6% G-mean, and 99% area under curve. The computation time required to run the entire algorithm was just 5.17 s. The experiment results demonstrate that the proposed algorithm yields a superior performance to previous studies and other classifiers. The proposed algorithm can serve as a new supportive tool in the automated diagnosis of cancer cells from cytology images.
Scrum - A Pocket Guide

This pocket guide is the one book to read for everyone who wants to learn about Scrum. The book covers all roles, rules and the main principles underpinning Scrum, and is based on the Scrum Guide Edition 2013. A broader context to this fundamental description of Scrum is given by describing the past and the future of Scrum. The author, Gunther Verheyen, has created a concise, yet complete and passionate reference about Scrum. The book demonstrates his core view that Scrum is about a journey, a journey of discovery and fun. He designed the book to be a helpful guide on that journey. This Pocket Guide is also an essential study aid for training for Scrum certifications: Certified Scrum Master (ScrumAlliance) Certified Scrum Product Owner (ScrumAlliance) Professional Scrum Foundations (PSF, Scrum.org) Professional Scrum Master (PSM, Scrum.org) Ken Schwaber, Scrum co-creator says that this book currently is the best available description of Scrum around. The book combines some rare characteristics: It describes Scrum in its entirety, yet places it in a broader context (of past and future). The author focuses on the subject, Scrum, in a way that it truly supports the reader. The book has a language and style in line with the philosophy of Scrum. The book shows the playfulness of Scrum. David Starr and Ralph Jocham, Professional Scrum trainers and early agile adopters, say that this is the ultimate book to be advised as follow-up book to the students they teach Scrum to and to teams and managers of organizations that they coach Scrum to.
Applied Gauge/Gravity Duality from Supergravity to Superconductivity

The sequence of chapters can be divided into three blocks. - The first block contains the introductory chapters. In chapter 1 we illustrate the problem of the high-Tc superconductors making a parallelism between the Fermi Liquid theory, the BCS theory of superconductivity and the theory which is currently supposed to describe electron doped high-Tc superconductors at weak coupling. In chapter 2 we describe the aspects of the AdS/CFT correspondence that will be relevant throughout the reading of the thesis. - The second block coincides with chapter 3. In this chapter we define the concept of holographic superconductivity and we study phenomenological models of holographic superconductors. These are bottom-up models in the sense that they do not come from any particular string theory. This chapter has several important results, among them we mention, the classification of the holographic phase transitions and the characterization of the optical conductivity. - The third block contains the chapters from 4 to 7. The mainstream is the study of top-down models of holographic superconductors that naturally arise as smaller sectors of consistent truncations of type IIB supergravity. In chapter 4 we consider N = 8 supergravity and we describe the building blocks of N = 2 supergravity looking for such holographic superconductors. In this setup, the AdS/CFT dictionary is very well understood and we identify the analog of a Cooper pair state. In chapter 5, we discuss holographic superconductivity in the type IIB theory on AdS5 x S5 whereas in chapter 6, we consider the more general setting of type IIB theory compactified on Sasaki-Einstein manifolds. Among several examples, we will consider the interesting case of AdS5 x T1;1. In chapter 7, we study a four dimensional N = 2 supergravity which is related to M-theory, we find a novel family of holographic superconductor and we describe in detail the properties of gravitational background providing its interpretation in the dual field theory. We close the discussion about phenomenological models of holographic superconductivity and supergravity with conclusions and outlook. Finally, the thesis is equipped with two appendices in which we set up the the notation that will be adopted in the various chapters. Both these appendices are also thought as a quick and practical reminder of known results in the literature about field theory and supergravity.
First-passage problem for the Rouse polymer chain: An exact solution

We solve the first-passage problem of a non-Markovian process arising in the reaction diffusion theory of polymer chains. By considering the Rouse chain, a free-draining dynamic model of a polymer where the chain monomers are represented by beads and the chain connectivity by harmonic springs, we develop an exact analytical method for describing the kinetics of end-chain reactions. Our analytical results illuminate the approximations used previously and are in perfect agreement with numerical stochastic simulations.
Very extended E8 and A8 at low levels, gravity and supergravity

We define a level for a large class of Lorentzian Kac–Moody algebras. Using this we find the representation content of very extended AD−3 and E8 (i.e., E11) at low levels in terms of AD−1 and A10 representations, respectively. The results are consistent with the conjectured very extended A8 and E11 symmetries of gravity and maximal supergravity theories given respectively in preprints hep-th/0104081 and hep-th/0107209. We explain how these results provided further evidence for these conjectures.
A globally well-behaved simultaneity connection for stationary frames in the weak field limit

Local simultaneity conventions are mathematically represented by connections on the bundle of timelike curves that defines the frame. Those simultaneity conventions having an holonomy proportional to the Riemann tensor have a special interest since they exhibit good global behaviour in the weak field limit. By requiring that the simultaneity convention depends on the acceleration, vorticity vector and the angle between them we are able to restrict considerably the allowed simultaneity conventions. In particular, we focus our study on the simplest among the allowed conventions. It should be preferred over Einstein's in flat spacetime and in general if the tidal force between neighbouring particles is weaker than the centrifugal force. It reduces to the Einstein convention if the vectorial product between the acceleration and the vorticity vector vanishes. We finally show how to use this convention in practice.
An Efficient Multiple Fault Detection Technique in Digital Microfluidic Biochips

ABSTRACT The involvement of Digital Microfluidic Biochips (DMFBs) in the field of disease detection, automated drug discovery, on-chip DNA (Deoxyribonucleic acid) analysis has become well-accepted during last decades. Though trustworthiness of Digital Microfluidic Biochip system plays a vital role in point-of-care diagnosis, defective electrodes are the main reasons for various misleading assay performances. It also affects overall assay completion time; even it leads to discard a chip in the worst scenario. Hence, fault detection is a crucial need. In this paper, an efficient fault detection mechanism is formulated to identify multiple numbers of defective/faulty electrodes on an m × n biochip array, where m and n can be of any positive number. Test droplets are strategically routed throughout an arbitrary sized electrode array and capacitive sensing circuit is deployed to take decision about existence of faults. The basic idea of the proposed technique is to identify actual positions of faulty electrodes through boundary test, row test, and diagonal test. In some complicated cases, instead of finding exact faulty location(s), through an extended testing our proposed technique identifies faulty zone(s) (it is a bounded region where one or more defective electrodes reside) to ensure safe assay performance on a chip. A detailed study evaluates the proposed approach considering different faulty environments.
Comparisons of peak SAR levels in concentric sphere head models of children and adults for irradiation by a dipole at 900 MHz

The aim of this study is to examine the scale and significance of differences in peak specific energy absorption rate (SAR) in the brains of children and adults exposed to radiofrequency emissions from mobile phones. Estimates were obtained by method of multipole analysis of a three layered (scalp/cranium/brain) spherical head exposed to a nearby 0. 4λ dipole at 900 MHz. A literature review of head parameters that influence SAR induction revealed strong indirect evidence based on total body water content that there are no substantive age-related changes in tissue conductivity after the first year of life. However, it was also found that the thickness of the ear, scalp and cranium do decrease on average with decreasing age, though individual variability within any age group is very high. The model analyses revealed that compared to an average adult, the peak brain 10 g averaged SAR in mean 4, 8, 12 and 16 year olds (yo) is increased by a factor of 1.31, 1.23, 1.15 and 1.07, respectively. However, contrary to the expectations of a recent prominent expert review, the UK Stewart Report, the relatively small scale of these increases does not warrant any special precautionary measures for child mobile phone users since: (a) SAR testing protocols as contained in the CENELEC (2001) standard provide an additional safety margin which ensures that allowable localized SAR limits are not exceeded in the brain; (b) the maximum worst case brain temperature rise (∼0.13 to 0.14 °C for an average 4 yo) in child users of mobile phones is well within safe levels and normal physiological parameters; and (c) the range of age average increases in children is less than the expected range of variation seen within the adult population.
Trois nouvelles méthodes de classification automatique de données symboliques de type intervalle

Trois methodes de classification automatique basees sur l'algorithme des Nuees Dynamiques sont presentees et comparees. Elles generent une partition d'un ensemble de donnees de type intervalle et utilisent des prototypes, des distances et des criteres d'homogeneite differents. Une evaluation de ces trois approches sera faite a partir de deux jeux de donnees.
Achieving Robustness by Anomaly Detection using Multiple Sensors

최근 자동차 사이버 물리 시스템이 많은 차량 내 센서를 탑재함에 따라, 이에 대한 공격이슈가 대두되고 있다. 다양한 센서들을 통해 운전자에게 다양한 정보를 전달함으로써 편리성을 도모하는 반면, 이를 악용할 수 있는 여지와 공격 기술들이 보고되고 있다. 이러한 공격은 액추에이터의 물리적 파괴를 야기한다. 따라서, 지능형 교통 시스템에서의 안전성 증진을 위한 강인한 시스템이 요구되었다. 본 논문에서는 이상 탐지 매커니즘을 제안하여, 공격 상황에서 이상 센서를 분별하여 핵심적인 기능을 최대한으로 유지할 수 있도록 한다. 첫 번째로, 재귀 최소 자승법을 통해 이상 상태를 감지한다. 서로 유사한 기능을 하는 적응형 필터링 알고리즘들을 비교하여 재귀 최소 자승법이 리얼타임 운용에 최적임을 밝혀내었다. 또한 이 알고리즘을 통해 다수의 센서가 비정상 상태에 있더라도 그 가운데 문턱값을 초과하는 이상 데이터를 감지할 수 있었다. 두 번째로, 반복 필터링 알고리즘을 통해 정상적인 센서 값들을 이용한 신뢰성 있는 평균 센서 값을 결정하였다. 이 값은 컨트롤러가 크루즈 컨트롤 수행을 위해 참조값과 비교하기 위해 필요한 값이며, 하나의 값으로 제공되어야 한다. 다양한 평균 값 도출 알고리즘 가운데 IF 알고리즘의 신뢰성을 평가하였다. 실험 결과, 공격 신호가 주어질 때, 제안하는 매커니즘이 적용되지 않은 경우에 크루즈 컨트롤 시스템이 실패하여 시뮬레이터 내의 자동차 모델이 사고를 당하는 것을 보았다. 반면, 제안하는 매커니즘이 적용된 크루즈 컨트롤 시스템은 공격 신호가 들어와도 정상적으로 동작함을 확인하였다. 결론적으로, 이상 감지와 신뢰성 있는 평균 센서 값도출을 위해서 재귀 최소 자승법과 반복 필터링 알고리즘을 함께 사용함으로써 공격에 강인한 크루즈 컨트롤 시스템을 구현할 수 있었다. ⓒ 2016 DGIST
True Random Number Generator through Beat Frequency Oscillators in FPGA

True random number generator finds applications in cryptography, communications, industrial testing, computer games, random padding and Monte Carlo simulations. Software based random number generators suffers from higher delay due to serial execution of codes, low quality due to correlated data, low throughput and large processing time. FPGA based random number generators are efficient due to parallelism and bit wise operation. In this paper, an attempt has been made to evaluate the performance of the true random number generator based on beat frequency oscillators using FPGA. Asynchronous modulo ‘D’ counters are explored as beat frequency oscillators. Varying the value of D for both the asynchronous clock divider units along with maintaining higher frequency at oscillator X, adds to the randomness of the generated bit streams. Clock frequency divider ‘D’ can be selected from the set of values stored in memory. One of the most important advantages of the beat frequency based true random number generator is its tunability through controlling parameter, partial reconfiguration, placement and routing. The technique does not depend on the type and manufacturer of the FPGA, placement and routing in the process of implementation and requires low hardware footprint. Mathematical model, VHDL simulation and experimental results of the true random number generator are discussed. The proposed architecture for TRNG was simulated using VHDL through Xilinx ISE 14.1 software platform and implemented on Virtex 5 XC5VLX20T FPGA device. The random bit stream passes the entire NIST statistical test suite.