Directory of Open Access Journals (Sweden)
Raja Roy Choudhury
2013-01-01
Full Text Available A faster and accurate semianalytical formulation with a robust optimization solution for estimating the splice loss of graded-index fibers has been proposed. The semianalytical optimization of modal parameters has been carried out by Nelder-Mead method of nonlinear unconstrained minimization suitable for functions which are uncertain, noisy, or even discontinuous. Instead of normally used Gaussian function, as the trial field for the fundamental mode of graded-index optical fiber a novel sinc function with exponentially and R-3/2 (R is the normalized radius of the optical fiber decaying trailing edge has been used. Due to inclusion of three parameters in the optimization of fundamental modal solution and application of an efficient optimization technique with simple analytical expressions for various modal parameters, the results are found to be accurate and computationally easier to find than the standard numerical method solution.
Fundamental stellar parameters
Wittkowski, M
2004-01-01
I present a discussion of fundamental stellar parameters and their observational determination in the context of interferometric measurements with current and future optical/infrared interferometric facilities. Stellar parameters and the importance of their determination for stellar physics are discussed. One of the primary uses of interferometry in the field of stellar physics is the measurement of the intensity profile across the stellar disk, both as a function of position angle and of wavelength. High-precision fundamental stellar parameters are also derived by characterizations of binary and multiple system using interferometric observations. This topic is discussed in detail elsewhere in these proceedings. Comparison of observed spectrally dispersed center-to-limb intensity variations with models of stellar atmospheres and stellar evolution may result in an improved understanding of key phenomena in stellar astrophysics such as the precise evolutionary effects on the main sequence, the evolution of meta...
An Analytic Method for Measuring Accurate Fundamental Frequency Components
Energy Technology Data Exchange (ETDEWEB)
Nam, Soon Ryul; Park Jong Keun [Seoul National University, Seoul(Korea); Kang, Sang Hee [Myongji University, Seoul (Korea)
2002-04-01
This paper proposes an analytic method for measuring the accurate fundamental frequency component of a fault current signal distorted with a DC-offset, a characteristic frequency component, and harmonics. The proposed algorithm is composed of four stages: sine filer, linear filter, Prony's method, and measurement. The sine filter and the linear filter eliminate harmonics and the fundamental frequency component, respectively. Then Prony's method is used to estimate the parameters of the DC-offset and the characteristic frequency component. Finally, the fundamental frequency component is measured by compensating the sine-filtered signal with the estimated parameters. The performance evaluation of the proposed method is presented for a-phase to ground faults on a 345 kV 200 km overhead transmission line. The EMTP is used to generate fault current signals under different fault locations and fault inception angles. It is shown that the analytic method accurately measures the fundamental frequency component regardless of the characteristic frequency component as well as the DC-offset.(author). 19 refs., 4 figs., 4 tabs.
Fundamental Parameters of 4 Massive Eclipsing Binaries in Westerlund 1
Bonanos, Alceste Z.; Koumpia, E.
2011-05-01
We present fundamental parameters of 4 massive eclipsing binaries in the young massive cluster Westerlund 1. The goal is to measure accurate masses and radii of their component stars, which provide much needed constraints for evolutionary models of massive stars. Accurate parameters can further be used to determine a dynamical lower limit for the magnetar progenitor and to obtain an independent distance to the cluster. Our results confirm and extend the evidence for a high mass for the progenitor of the magnetar. The authors acknowledge research and travel support from the European Commission Framework Program Seven under the Marie Curie International Reintegration Grant PIRG04-GA-2008-239335.
Orbital Solution & Fundamental Parameters of sigma Scorpii
North, J R; Tuthill, P G; Tango, W J; Robertson, J G
2007-01-01
The first orbital solution for the spectroscopic pair in the multiple star system sigma Scorpii, determined from measurements with the Sydney University Stellar Interferometer (SUSI), is presented. The primary component is of beta Cephei variable type and has been one of the most intensively studied examples of its class. The orbital solution, when combined with radial velocity results found in the literature, yields a distance of 174(+23,-18) pc, which is consistent with, but more accurate than the Hipparcos value. For the primary component we determine 18.4+/-5.4 M_sun, -4.12+/-0.34 mag and 12.7+/-1.8 R_sun for the mass, absolute visual magnitude and radius respectively. A B1 dwarf spectral type and luminosity class for the secondary is proposed from the mass determination of 11.9+/-3.1 M_sun and the estimated system age of 10 Myr.
Fundamental Parameters and Chemical Composition of Arcturus
Ramirez, I
2011-01-01
We derive a self-consistent set of atmospheric parameters and abundances of 17 elements for the red giant star Arcturus: Teff = 4286+/-30 K, logg = 1.66+/-0.05, and [Fe/H] = -0.52+/-0.04. The effective temperature was determined using model atmosphere fits to the observed spectral energy distribution from the blue to the mid-infrared (0.44 to 10 um). The surface gravity was calculated using the trigonometric parallax of the star and stellar evolution models. A differential abundance analysis relative to the solar spectrum allowed us to derive iron abundances from equivalent width measurements of 37 FeI and 9 FeII lines, unblended in the spectra of both Arcturus and the Sun; the [Fe/H] value adopted is derived from FeI lines. We also determine the mass, radius, and age of Arcturus: M = 1.08+/-0.06 Msun, R = 25.4+/-0.2 Rsun, and t = 7.1(+1.5/-1.2) Gyr. Finally, abundances of the following elements are measured from an equivalent width analysis of atomic features: C, O, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, ...
Fundamental Parameters of Kepler Eclipsing Binaries. I. KIC 5738698
Matson, Rachel A; Guo, Zhao; Orosz, Jerome A
2016-01-01
Eclipsing binaries serve as a valuable source of stellar masses and radii that inform stellar evolutionary models and provide insight into additional astrophysical processes. The exquisite light curves generated by space-based missions such as Kepler offer the most stringent tests to date. We use the Kepler light curve of the 4.8-day eclipsing binary KIC 5739896 with ground based optical spectra to derive fundamental parameters for the system. We reconstruct the component spectra to determine the individual atmospheric parameters, and model the Kepler photometry with the binary synthesis code ELC to obtain accurate masses and radii. The two components of KIC 5738698 are F-type stars with M1 = 1.39+/-0.04M, M2 = 1.34+/-0.06M, and R1 = 1.84+/-0.03R, R2 = 1.72+/-0.03R. We also report a small eccentricity (e < 0.0017) and unusual albedo values that are required to match the detailed shape of the Kepler light curve. Comparisons with evolutionary models indicate an approximate age of 2.3 Gyr for the system.
Accurate Estimation of Low Fundamental Frequencies from Real-Valued Measurements
DEFF Research Database (Denmark)
Christensen, Mads Græsbøll
2013-01-01
In this paper, the difficult problem of estimating low fundamental frequencies from real-valued measurements is addressed. The methods commonly employed do not take the phenomena encountered in this scenario into account and thus fail to deliver accurate estimates. The reason for this is that the......In this paper, the difficult problem of estimating low fundamental frequencies from real-valued measurements is addressed. The methods commonly employed do not take the phenomena encountered in this scenario into account and thus fail to deliver accurate estimates. The reason...... for this is that they employ asymptotic approximations that are violated when the harmonics are not well-separated in frequency, something that happens when the observed signal is real-valued and the fundamental frequency is low. To mitigate this, we analyze the problem and present some exact fundamental frequency estimators...
Fundamental parameters of four massive eclipsing binaries in Westerlund 1
Koumpia, E.; Bonanos, A. Z.
2012-01-01
Context. Only a small number of high mass stars (> 30 M-circle dot) have fundamental parameters (i.e. masses and radii) measured with high enough accuracy from eclipsing binaries to constrain formation and evolutionary models of massive stars. Aims. This work aims to increase this limited sample, by
Fundamental parameters of four massive eclipsing binaries in Westerlund 1
Koumpia, E.; Bonanos, A. Z.
2012-01-01
Context. Only a small number of high mass stars (>30 M⊙) have fundamental parameters (i.e. masses and radii) measured with high enough accuracy from eclipsing binaries to constrain formation and evolutionary models of massive stars. Aims: This work aims to increase this limited sample, by studying t
Accurate parameter estimation for unbalanced three-phase system.
Chen, Yuan; So, Hing Cheung
2014-01-01
Smart grid is an intelligent power generation and control console in modern electricity networks, where the unbalanced three-phase power system is the commonly used model. Here, parameter estimation for this system is addressed. After converting the three-phase waveforms into a pair of orthogonal signals via the α β-transformation, the nonlinear least squares (NLS) estimator is developed for accurately finding the frequency, phase, and voltage parameters. The estimator is realized by the Newton-Raphson scheme, whose global convergence is studied in this paper. Computer simulations show that the mean square error performance of NLS method can attain the Cramér-Rao lower bound. Moreover, our proposal provides more accurate frequency estimation when compared with the complex least mean square (CLMS) and augmented CLMS.
Multi-Layered Neural Networks Infer Fundamental Stellar Parameters
Verma, Kuldeep; Bhattacharya, Jishnu; Antia, H M; Krishnamurthy, Ganapathy
2016-01-01
The advent of space-based observatories such as CoRoT and Kepler has enabled the testing of our understanding of stellar evolution on thousands of stars. Evolutionary models typically require five input parameters, the mass, initial Helium abundance, initial metallicity, mixing-length (assumed to be constant over time) and the age to which the star must be evolved. These parameters are also very useful in characterizing the associated planets and in studying galactic archaeology. How to obtain the parameters from observations rapidly and accurately, specifically in the context of surveys of thousands of stars, is an outstanding question, one that has eluded straightforward resolution. For a given star, we typically measure the effective temperature and surface metallicity spectroscopically and low-degree oscillation frequencies through space observatories. Here we demonstrate that statistical learning, using multi-layered neural networks, is successful in determining the evolutionary parameters based on spect...
Clusters as benchmarks for measuring fundamental stellar parameters
Bell, Cameron P M
2016-01-01
In this contribution I will discuss fundamental stellar parameters as determined from young star clusters; specifically those with ages less than or approximately equal to that of the Pleiades. I will focus primarily on the use of stellar evolutionary models to determine the ages and masses of stars, as well as discuss the limitations of such models using a combination of both young clusters and eclipsing binary systems. In addition, I will also highlight a few interesting recent results from large on-going spectroscopic surveys (specifically Gaia-ESO and APOGEE/IN-SYNC) which are continuing to challenge our understanding of the formation and early evolutionary stages of young clusters.
Semi-analytical Formulas for the Fundamental Parameters of Galactic Early B Supergiants
Directory of Open Access Journals (Sweden)
Zaninetti, L.
2009-12-01
Full Text Available The publication of new tables of calibration of some fundamental parameters of Galactic B0-B5 supergiants in the two classes $I_mathrm{a}$ and $I_mathrm{b} $ allows to particularize the eight parameters conjecture that model five fundamental parameters. The numerical expressions for visual magnitude, radius, mass, luminosity and surface gravity are derived for supergiants in the range of temperature between 29700 K and 15200 K. The availability of accurate tables of calibration allows us to estimate the efficiency of the derived formulas in reproducing the observed values. The average efficiency of the new formulas, expressed in percent, is 94 for the visual magnitude, 81 for the mass, 96 for the radius, 99 for the logarithm of the luminosity and 97 for the logarithm of the surface gravity.
Fundamental Parameters of Some New Discovered Open star Clusters
El-Bendary, R
2010-01-01
We present here the fundamental properties of some newly discovered open star clusters (Teutsch 144, Alessi 53, Riddle 4 and Juchrt 12) using the JHK Near-IR photometry (2MASS survey) of Cutri et al. (2003). These clusters have been selected from Kronberger et al. (2006) who presented some new discovered stellar groups on the basis of 2MASS photometry and the DSS visual images. The astrometry and photometric parameters are determined using the stellar density distributions and color-magnitude diagrams fittings. Center, radius, membership, distances, reddening, age, luminosity function, mass function, total mass, and the dynamical relaxation time have been estimated for the first time. This paper is a part of Reda's PhD project.
Fundamental radiation effects parameters in metals and ceramics
Energy Technology Data Exchange (ETDEWEB)
Zinkle, S.J. [Oak Ridge National Lab., TN (United States)
1998-03-01
Useful information on defect production and migration can be obtained from examination of the fluence-dependent defect densities in irradiated materials, particularly when a transition from linear to sublinear accumulation is observed. Further work is needed on several intriguing reported radiation effects in metals. The supralinear defect cluster accumulation regime in thin foil irradiated metals needs further experimental confirmation, and the physical mechanisms responsible for its presence need to be established. Radiation hardening and the associated reduction in strain hardening capacity in FCC metals is a serious concern for structural materials. In general, the loss of strain hardening capacity is associated with dislocation channeling, which occurs when a high density of small defect clusters are produced (stainless steel irradiated near room temperature is a notable exception). Detailed investigations of the effect of defect cluster density and other physical parameters such as stacking fault energy on dislocation channeling are needed. Although it is clearly established that radiation hardening depends on the grain size (radiation-modified Hall-Petch effect), further work is needed to identify the physical mechanisms. In addition, there is a need for improved hardening superposition models when a range of different obstacle strengths are present. Due to a lack of information on point defect diffusivities and the increased complexity of radiation effects in ceramics compared to metals, many fundamental radiation effects parameters in ceramics have yet to be determined. Optical spectroscopy data suggest that the oxygen monovacancy and freely migrating interstitial fraction in fission neutron irradiated MgO and Al{sub 2}O{sub 3} are {approximately}10% of the NRT displacement value. Ionization induced diffusion can strongly influence microstructural evolution in ceramics. Therefore, fundamental data on ceramics obtained from highly ionizing radiation sources
Fundamental Parameters of Main-Sequence Stars in an Instant with Machine Learning
Bellinger, Earl P; Hekker, Saskia; Basu, Sarbani; Ball, Warrick; Guggenberger, Elisabeth
2016-01-01
Owing to the remarkable photometric precision of space observatories like Kepler, stellar and planetary systems beyond our own are now being characterized en masse for the first time. These characterizations are pivotal for endeavors such as searching for Earth-like planets and solar twins, understanding the mechanisms that govern stellar evolution, and tracing the dynamics of our Galaxy. The volume of data that is becoming available, however, brings with it the need to process this information accurately and rapidly. While existing methods can constrain fundamental stellar parameters such as ages, masses, and radii from these observations, they require substantial computational efforts to do so. We develop a method based on machine learning for rapidly estimating fundamental parameters of main-sequence solar-like stars from classical and asteroseismic observations. We first demonstrate this method on a hare-and-hound exercise and then apply it to the Sun, 16 Cyg A & B, and 34 planet-hosting candidates th...
Fundamental Parameters of the Open Cluster Kronberger 1
Sujatha, S.; Krishna Kumar, K.; Komala, S.
2016-09-01
In this paper, we present the fundamental physical parameters and the present-day mass function of the open cluster Kronberger 1. The cluster radius is estimated to be 3' and the interstellar extinction E(B-V) in the line-of-sight of the cluster is found to be 0.45±0.05 mag. This cluster is located in the direction of Auriga constellation at a distance of 2.5±0.2 kpc. From the appropriate theoretical isochrones, the log(age) of the cluster is found to be 7.65. The mass function slope for Kronberger 1 is derived for the first time and it is estimated to be α = 2.72±0.2 which is in agreement with the slope of α = 2.35 given by Salpeter. Similar results are obtained from a near infrared study performed using data from the Two Micron All Sky Survey thus substantiating the results obtained from the optical analysis. These results indicate that Kronberger 1 is a suitable object for mapping the spiral arm structure of our Galaxy and for understanding the behavior of mass function in the Galactic disk.
Determination of fundamental asteroseismic parameters using the Hilbert transform
Kiefer, René; Herzberg, Wiebke; Roth, Markus
2015-01-01
Context. Solar-like oscillations exhibit a regular pattern of frequencies. This pattern is dominated by the small and large frequency separations between modes. The accurate determination of these parameters is of great interest, because they give information about e.g. the evolutionary state and the mass of a star. Aims. We want to develop a robust method to determine the large and small frequency separations for time series with low signal-tonoise ratio. For this purpose, we analyse a time series of the Sun from the GOLF instrument aboard SOHO and a time series of the star KIC 5184732 from the NASA Kepler satellite by employing a combination of Fourier and Hilbert transform. Methods. We use the analytic signal of filtered stellar oscillation time series to compute the signal envelope. Spectral analysis of the signal envelope then reveals frequency differences of dominant modes in the periodogram of the stellar time series. Results. With the described method the large frequency separation $\\Delta\
Accurate absolute parameters of the binary system V4089 Sgr
Veramendi, M E
2014-01-01
We carried out a spectroscopic-photometric analysis of the binary V4089 Sgr with the aim to obtain absolute masses and radii of the components and to contrast these parameters with stellar evolution theoretical models. We took high-resolution spectra and measured radial velocity using standard cross-correlations and a technique of spectral disentangling. Absolute parameters of the components were determined through the simultaneous fitting of measured radial velocities and Geneva photometric data available in the literature. In this way we obtained Ma=2.584+-0.008 Msun, Mb=1.607+-0.007 Msun, Ra=3.959+-0.013 Rsun, and Rb=1.605+-0.016 Rsun. The comparison of these parameters with two grids of theoretical models led to estimate narrow ranges of possible values for system metallicity and age. According circularization theory it is not expected that the binary had been achieved a circular orbit as a result of tidal friction, so the null eccentricity found is an interesting fact. On the other hand, we measured proj...
Accurate Critical Parameters for the Modified Lennard-Jones Model
Okamoto, Kazuma; Fuchizaki, Kazuhiro
2017-03-01
The critical parameters of the modified Lennard-Jones system were examined. The isothermal-isochoric ensemble was generated by conducting a molecular dynamics simulation for the system consisting of 6912, 8788, 10976, and 13500 particles. The equilibrium between the liquid and vapor phases was judged from the chemical potential of both phases upon establishing the coexistence envelope, from which the critical temperature and density were obtained invoking the renormalization group theory. The finite-size scaling enabled us to finally determine the critical temperature, pressure, and density as Tc = 1.0762(2), pc = 0.09394(17), and ρc = 0.331(3), respectively.
Fundamental Parameters of Main-Sequence Stars in an Instant with Machine Learning
Bellinger, Earl P.; Angelou, George C.; Hekker, Saskia; Basu, Sarbani; Ball, Warrick H.; Guggenberger, Elisabeth
2016-10-01
Owing to the remarkable photometric precision of space observatories like Kepler, stellar and planetary systems beyond our own are now being characterized en masse for the first time. These characterizations are pivotal for endeavors such as searching for Earth-like planets and solar twins, understanding the mechanisms that govern stellar evolution, and tracing the dynamics of our Galaxy. The volume of data that is becoming available, however, brings with it the need to process this information accurately and rapidly. While existing methods can constrain fundamental stellar parameters such as ages, masses, and radii from these observations, they require substantial computational effort to do so. We develop a method based on machine learning for rapidly estimating fundamental parameters of main-sequence solar-like stars from classical and asteroseismic observations. We first demonstrate this method on a hare-and-hound exercise and then apply it to the Sun, 16 Cyg A and B, and 34 planet-hosting candidates that have been observed by the Kepler spacecraft. We find that our estimates and their associated uncertainties are comparable to the results of other methods, but with the additional benefit of being able to explore many more stellar parameters while using much less computation time. We furthermore use this method to present evidence for an empirical diffusion-mass relation. Our method is open source and freely available for the community to use.6
Is Gy’s formula for the Fundamental Sampling Error accurate? Experimental evidence
Geelhoed, B.
2011-01-01
Pierre Gy’s theory for the sampling of particulate materials is widely applied and taught. A crucial part of Gy’s theory deals with the estimation, prediction and minimization of the variance of the Fundamental Sampling Error using a formula that is known as “Gy’s formula”. Experimental evidence, ho
Recent variations of fundamental parameters and their implications for gravitation
Dent, Thomas
2010-01-01
We compare the sensitivity of a recent bound on time variation of the fine structure constant from optical clocks with bounds on time varying fundamental constants from atomic clocks sensitive to the electron-to-proton mass ratio, from radioactive decay rates in meteorites, and from the Oklo natural reactor. Tests of the Weak Equivalence Principle also lead to comparable bounds on present time variations of constants, as well as putting the strongest limits on variations tracking the gravitational potential. For recent time variations, the "winner in sensitivity" depends on possible relations between the variations of different couplings in the standard model of particle physics. WEP tests are currently the most sensitive within scenarios with unification of gauge interactions. A detection of time variation in atomic clocks would favour dynamical dark energy and put strong constraints on the dynamics of a cosmological scalar field.
Foster, Michael E; 10.1021/ct300420f
2012-01-01
Using a non-empirically tuned range-separated DFT approach, we study both the quasiparticle properties (HOMO-LUMO fundamental gaps) and excitation energies of DNA and RNA nucleobases (adenine, thymine, cytosine, guanine, and uracil). Our calculations demonstrate that a physically-motivated, first-principles tuned DFT approach accurately reproduces results from both experimental benchmarks and more computationally intensive techniques such as many-body GW theory. Furthermore, in the same set of nucleobases, we show that the non-empirical range-separated procedure also leads to significantly improved results for excitation energies compared to conventional DFT methods. The present results emphasize the importance of a non-empirically tuned range-separation approach for accurately predicting both fundamental and excitation gaps in DNA and RNA nucleobases.
A Novel Tool for the Spectroscopic Inference of Fundamental Stellar Parameters
Czekala, Ian; Andrews, Sean M.; Latham, David W.; Torres, Guillermo
2014-06-01
We present a novel approach for making accurate and unbiased inferences of fundamental stellar parameters (e.g., effective temperature, surface gravity, metallicity) from spectroscopic observations, with reference to a library of synthetic spectra. The forward-modeling formalism we have developed is generic (easily adaptable to data from any instrument or covering any wavelength range) and modular, in that it can incorporate external prior knowledge or additional data (e.g., broadband photometry) and account for instrumental and non-stellar effects on the spectrum (e.g., parametric treatments of extinction, spots, etc.). An approach that employs adaptive correlated noise is used to account for systematic discrepancies between the observations and the synthetic spectral library, ensuring that issues like uncertainties in atomic or molecular constants do not strongly bias the parameter inferences. In addition to extracting a set of unbiased inferences of the (posterior) probability distributions for basic stellar parameters, our modeling approach also "maps" out problematic spectral regions in the synthetic libraries that could be used as a basis for improving the models. As a demonstration, we present some preliminary results from modeling optical spectra of well-characterized exoplanet host stars and nearby pre-main sequence stars. A basic set of adaptable software that performs this modeling approach will be released publicly.
DEFF Research Database (Denmark)
Christensen, Leif Højslet; Pind, Niels
1982-01-01
secondary target a number of relative calibration constants are calculated on the basis of knowledge of the irradiation geometry, the detector specifications, and tabulated fundamental physical parameters. The absolute calibration of the spectrometer is performed by measuring one pure element standard per......A matrix-independent fundamental parameter-based calibration model for an energy-dispersive X-ray fluorescence spectrometer has been developed. This model, which is part of a fundamental parameter approach quantification method, accounts for both the excitation and detection probability. For each...
Estimating stellar fundamental parameters using PCA: application to early type stars of GES data
Farah, W; Paletou, F; Blomme, R
2015-01-01
This work addresses a procedure to estimate fundamental stellar parameters such as T eff , logg, [Fe/H], and v sin i using a dimensionality reduction technique called Principal Component Analysis (PCA), applied to a large database of synthetic spectra. This technique shows promising results for inverting stellar parameters of observed targets from Gaia ESO Survey.
Directory of Open Access Journals (Sweden)
Duncan K Ralph
2016-01-01
Full Text Available VDJ rearrangement and somatic hypermutation work together to produce antibody-coding B cell receptor (BCR sequences for a remarkable diversity of antigens. It is now possible to sequence these BCRs in high throughput; analysis of these sequences is bringing new insight into how antibodies develop, in particular for broadly-neutralizing antibodies against HIV and influenza. A fundamental step in such sequence analysis is to annotate each base as coming from a specific one of the V, D, or J genes, or from an N-addition (a.k.a. non-templated insertion. Previous work has used simple parametric distributions to model transitions from state to state in a hidden Markov model (HMM of VDJ recombination, and assumed that mutations occur via the same process across sites. However, codon frame and other effects have been observed to violate these parametric assumptions for such coding sequences, suggesting that a non-parametric approach to modeling the recombination process could be useful. In our paper, we find that indeed large modern data sets suggest a model using parameter-rich per-allele categorical distributions for HMM transition probabilities and per-allele-per-position mutation probabilities, and that using such a model for inference leads to significantly improved results. We present an accurate and efficient BCR sequence annotation software package using a novel HMM "factorization" strategy. This package, called partis (https://github.com/psathyrella/partis/, is built on a new general-purpose HMM compiler that can perform efficient inference given a simple text description of an HMM.
Measuring Accurate Body Parameters of Dressed Humans with Large-Scale Motion Using a Kinect Sensor
Directory of Open Access Journals (Sweden)
Sidan Du
2013-08-01
Full Text Available Non-contact human body measurement plays an important role in surveillance, physical healthcare, on-line business and virtual fitting. Current methods for measuring the human body without physical contact usually cannot handle humans wearing clothes, which limits their applicability in public environments. In this paper, we propose an effective solution that can measure accurate parameters of the human body with large-scale motion from a Kinect sensor, assuming that the people are wearing clothes. Because motion can drive clothes attached to the human body loosely or tightly, we adopt a space-time analysis to mine the information across the posture variations. Using this information, we recover the human body, regardless of the effect of clothes, and measure the human body parameters accurately. Experimental results show that our system can perform more accurate parameter estimation on the human body than state-of-the-art methods.
In-situ measurements of material thermal parameters for accurate LED lamp thermal modelling
Vellvehi, M.; Perpina, X.; Jorda, X.; Werkhoven, R.J.; Kunen, J.M.G.; Jakovenko, J.; Bancken, P.; Bolt, P.J.
2013-01-01
This work deals with the extraction of key thermal parameters for accurate thermal modelling of LED lamps: air exchange coefficient around the lamp, emissivity and thermal conductivity of all lamp parts. As a case study, an 8W retrofit lamp is presented. To assess simulation results, temperature is
Fundamental parameters of FR II radio galaxies and their impact on groups and clusters' environments
Kapinska, Anna D
2012-01-01
Radio galaxies are among the largest and most powerful single objects known and are found at variety of redshifts, hence they are believed to have had a significant impact on the evolving Universe. Their relativistic jets inject considerable amounts of energy into the environments in which the sources reside; thus the knowledge of the fundamental properties (such as kinetic luminosities, lifetimes and ambient gas densities) of these sources is crucial for understanding AGN feedback in galaxy clusters. In this work, we explore the intrinsic and extrinsic fundamental properties of Fanaroff-Riley II (FR II) objects through the construction of multidimensional Monte Carlo simulations which use complete, flux limited radio catalogues and semi-analytical models of FR IIs' time evolution to create artificial samples of radio galaxies. This method allows us to set better limits on the confidence intervals of the intrinsic and extrinsic fundamental parameters and to investigate the total energy produced and injected t...
Reinbolt, Jeffrey A; Haftka, Raphael T; Chmielewski, Terese L; Fregly, Benjamin J
2007-05-01
Variations in joint parameter (JP) values (axis positions and orientations in body segments) and inertial parameter (IP) values (segment masses, mass centers, and moments of inertia) as well as kinematic noise alter the results of inverse dynamics analyses of gait. Three-dimensional linkage models with joint constraints have been proposed as one way to minimize the effects of noisy kinematic data. Such models can also be used to perform gait optimizations to predict post-treatment function given pre-treatment gait data. This study evaluates whether accurate patient-specific JP and IP values are needed in three-dimensional linkage models to produce accurate inverse dynamics results for gait. The study was performed in two stages. First, we used optimization analyses to evaluate whether patient-specific JP and IP values can be calibrated accurately from noisy kinematic data, and second, we used Monte Carlo analyses to evaluate how errors in JP and IP values affect inverse dynamics calculations. Both stages were performed using a dynamic, 27 degrees-of-freedom, full-body linkage model and synthetic (i.e., computer generated) gait data corresponding to a nominal experimental gait motion. In general, JP but not IP values could be found accurately from noisy kinematic data. Root-mean-square (RMS) errors were 3 degrees and 4 mm for JP values and 1 kg, 22 mm, and 74 500 kg * mm2 for IP values. Furthermore, errors in JP but not IP values had a significant effect on calculated lower-extremity inverse dynamics joint torques. The worst RMS torque error averaged 4% bodyweight * height (BW * H) due to JP variations but less than 0.25% (BW * H) due to IP variations. These results suggest that inverse dynamics analyses of gait utilizing linkage models with joint constraints should calibrate the model's JP values to obtain accurate joint torques.
Fundamental Parameter Method Applied to X-Ray Line Profile Analysis
Florica Matei; Nicolae Aldea; Marius Rada; Ioana Pop
2016-01-01
Crystallite size strain effect the mechanical, electric, magnetic and optical properties of many kind of the nanomaterials. The effects of the finite crystallite size and lattice strain can be very well observed as the deformation in the shape of the X-ray line profile (XRLP). In this contribution we have used the fundamental parameter (FP) [1,2] method to evaluate the nanostructure materials assuming a theoretical model of experimental XRLP. In this contribution we have used various distrib...
Constraining fundamental stellar parameters using seismology. Application to Alpha Centauri AB
Montalban, J
2005-01-01
We apply the Levenberg-Marquardt minimization algorithm to seismic and classical observables of the Alpha Cen binary system in order to derive the fundamental parameters of Alpha Cen A+B and to analyze the dependence of these parameters on the chosen observables, on their uncertainty and on the physics used in stellar modelling. The seismological data are those by Bouchy & Carrier (2002) for Alpha Cen A, and those by Carrier & Bourban (2003) for Alpha Cen B. We show that while the fundamental stellar parameters do not depend on the treatment of convection adopted (Mixing Length Theory -- MLT -- or ``Full Spectrum of Turbulence'' -- FST), the age of the system depends on the inclusion of gravitational settling, and is deeply biased by the small frequency separation of component B. We try to answer the question of the universality of the mixing length parameter, and we find a statistically reliable dependence of the alpha--parameter on the HR diagram location (with a trend similar to the one predicted b...
Institute of Scientific and Technical Information of China (English)
Xu Long; Fei Ge; Lei Wang; Youshi Hong
2009-01-01
This paper investigates the effects of structure parameters on dynamic responses of submerged floating tunnel (SFT) under hydrodynamic loads. The structure parameters includes buoyancy-weight ratio (BWR), stiffness coefficients of the cable systems, tunnel net buoyancy and tunnel length. First, the importance of structural damp in relation to the dynamic responses of SFT is demonstrated and the mechanism of structural damp effect is discussed. Thereafter, the fundamental structure parameters are investi-gated through the analysis of SFT dynamic responses under hydrodynamic loads. The results indicate that the BWR of SFT is a key structure parameter. When BWR is 1.2, there is a remarkable trend change in the vertical dynamic response of SFT under hydrodynamic loads. The results also indicate that the ratio of the tunnel net buoyancy to the cable stiffness coefficient is not a characteristic factor affecting the dynamic responses of SFT under hydrodynamic loads.
Passegger, Vera Maria; Reiners, Ansgar
2016-01-01
M-dwarf stars are the most numerous stars in the Universe; they span a wide range in mass and are in the focus of ongoing and planned exoplanet surveys. To investigate and understand their physical nature, detailed spectral information and accurate stellar models are needed. We use a new synthetic atmosphere model generation and compare model spectra to observations. To test the model accuracy, we compared the models to four benchmark stars with atmospheric parameters for which independent information from interferometric radius measurements is available. We used $\\chi^2$ -based methods to determine parameters from high-resolution spectroscopic observations. Our synthetic spectra are based on the new PHOENIX grid that uses the ACES description for the equation of state. This is a model generation expected to be especially suitable for the low-temperature atmospheres. We identified suitable spectral tracers of atmospheric parameters and determined the uncertainties in $T_{\\rm eff}$, $\\log{g}$, and [Fe/H] resul...
Shaltout, Abdallah A.; Moharram, Mohammed A.; Mostafa, Nasser Y.
2012-01-01
This work is the first attempt to quantify trace elements in the Catha edulis plant (Khat) with a fundamental parameter approach. C. edulis is a famous drug plant in east Africa and Arabian Peninsula. We have previously confirmed that hydroxyapatite represents one of the main inorganic compounds in the leaves and stalks of C. edulis. Comparable plant leaves from basil, mint and green tea were included in the present investigation as well as trifolium leaves were included as a non-related plant. The elemental analyses of the plants were done by Wavelength Dispersive X-Ray Fluorescence (WDXRF) spectroscopy. Standard-less quantitative WDXRF analysis was carried out based on the fundamental parameter approaches. According to the standard-less analysis algorithms, there is an essential need for an accurate determination of the amount of organic material in the sample. A new approach, based on the differential thermal analysis, was successfully used for the organic material determination. The obtained results based on this approach were in a good agreement with the commonly used methods. Depending on the developed method, quantitative analysis results of eighteen elements including; Al, Br, Ca, Cl, Cu, Fe, K, Na, Ni, Mg, Mn, P, Rb, S, Si, Sr, Ti and Zn were obtained for each plant. The results of the certified reference materials of green tea (NCSZC73014, China National Analysis Center for Iron and Steel, Beijing, China) confirmed the validity of the proposed method.
Accurate Structure Parameters for Tunneling Ionization Rates of Gas-Phase Linear Molecules
Zhao, Song-Feng; Li, Jian-Ke; Wang, Guo-Li; Li, Peng-Cheng; Zhou, Xiao-Xin
2017-03-01
In the molecular Ammosov–Delone–Krainov (MO-ADK) model of Tong et al. [Phys. Rev. A 66 (2002) 033402], the ionization rate depends on the structure parameters of the molecular orbital from which the electron is removed. We determine systematically and tabulate accurate structure parameters of the highest occupied molecular orbital (HOMO) for 123 gas-phase linear molecules by solving time-independent Schrödinger equation with B-spline functions and molecular potentials which are constructed numerically using the modified Leeuwen–Baerends (LBα) model. Supported by National Natural Science Foundation of China under Grant Nos. 11664035, 11674268, 11465016, 11364038, 11364039, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20116203120001 and the Basic Scientific Research Foundation for Institution of Higher Learning of Gansu Province
Verma, Kuldeep; Hanasoge, Shravan; Bhattacharya, Jishnu; Antia, H. M.; Krishnamurthi, Ganapathy
2016-10-01
The advent of space-based observatories such as Convection, Rotation and planetary Transits (CoRoT) and Kepler has enabled the testing of our understanding of stellar evolution on thousands of stars. Evolutionary models typically require five input parameters, the mass, initial helium abundance, initial metallicity, mixing length (assumed to be constant over time), and the age to which the star must be evolved. Some of these parameters are also very useful in characterizing the associated planets and in studying Galactic archaeology. How to obtain these parameters from observations rapidly and accurately, specifically in the context of surveys of thousands of stars, is an outstanding question, one that has eluded straightforward resolution. For a given star, we typically measure the effective temperature and surface metallicity spectroscopically and low-degree oscillation frequencies through space observatories. Here we demonstrate that statistical learning, using artificial neural networks, is successful in determining the evolutionary parameters based on spectroscopic and seismic measurements. Our trained networks show robustness over a broad range of parameter space, and critically, are entirely computationally inexpensive and fully automated. We analyse the observations of a few stars using this method and the results compare well to inferences obtained using other techniques. This method is both computationally cheap and inferentially accurate, paving the way for analysing the vast quantities of stellar observations from past, current, and future missions.
A Machine Learning Method to Infer Fundamental Stellar Parameters from Photometric Light Curves
Miller, A A; Richards, J W; Lee, Y S; Starr, D L; Butler, N R; Tokarz, S; Smith, N; Eisner, J A
2014-01-01
A fundamental challenge for wide-field imaging surveys is obtaining follow-up spectroscopic observations: there are > $10^9$ photometrically cataloged sources, yet modern spectroscopic surveys are limited to ~few x $10^6$ targets. As we approach the Large Synoptic Survey Telescope (LSST) era, new algorithmic solutions are required to cope with the data deluge. Here we report the development of a machine-learning framework capable of inferring fundamental stellar parameters (Teff, log g, and [Fe/H]) using photometric-brightness variations and color alone. A training set is constructed from a systematic spectroscopic survey of variables with Hectospec/MMT. In sum, the training set includes ~9000 spectra, for which stellar parameters are measured using the SEGUE Stellar Parameters Pipeline (SSPP). We employed the random forest algorithm to perform a non-parametric regression that predicts Teff, log g, and [Fe/H] from photometric time-domain observations. Our final, optimized model produces a cross-validated root...
Vieira, Vasco M. N. C. S.; Engelen, Aschwin H.; Huanel, Oscar R.; Guillemin, Marie-Laure
2016-01-01
Survival is a fundamental demographic component and the importance of its accurate estimation goes beyond the traditional estimation of life expectancy. The evolutionary stability of isomorphic biphasic life-cycles and the occurrence of its different ploidy phases at uneven abundances are hypothesized to be driven by differences in survival rates between haploids and diploids. We monitored Gracilaria chilensis, a commercially exploited red alga with an isomorphic biphasic life-cycle, having found density-dependent survival with competition and Allee effects. While estimating the linear-in-the-parameters survival function, all model I regression methods (i.e, vertical least squares) provided biased line-fits rendering them inappropriate for studies about ecology, evolution or population management. Hence, we developed an iterative two-step non-linear model II regression (i.e, oblique least squares), which provided improved line-fits and estimates of survival function parameters, while robust to the data aspects that usually turn the regression methods numerically unstable. PMID:27936048
VizieR Online Data Catalog: Fundamental parameters of Kepler stars (Silva Aguirre+, 2015)
Silva Aguirre, V.; Davies, G. R.; Basu, S.; Christensen-Dalsgaard, J.; Creevey, O.; Metcalfe, T. S.; Bedding, T. R.; Casagrande, L.; Handberg, R.; Lund, M. N.; Nissen, P. E.; Chaplin, W. J.; Huber, D.; Serenelli, A. M.; Stello, D.; van Eylen, V.; Campante, T. L.; Elsworth, Y.; Gilliland, R. L.; Hekker, S.; Karoff, C.; Kawaler, S. D.; Kjeldsen, H.; Lundkvist, M. S.
2016-02-01
Our sample has been extracted from the 77 exoplanet host stars presented in Huber et al. (2013, Cat. J/ApJ/767/127). We have made use of the full time-base of observations from the Kepler satellite to uniformly determine precise fundamental stellar parameters, including ages, for a sample of exoplanet host stars where high-quality asteroseismic data were available. We devised a Bayesian procedure flexible in its input and applied it to different grids of models to study systematics from input physics and extract statistically robust properties for all stars. (4 data files).
Fundamental Parameter Method Applied to X-Ray Line Profile Analysis
Directory of Open Access Journals (Sweden)
Florica Matei
2016-11-01
Full Text Available Crystallite size strain effect the mechanical, electric, magnetic and optical properties of many kind of the nanomaterials. The effects of the finite crystallite size and lattice strain can be very well observed as the deformation in the shape of the X-ray line profile (XRLP. In this contribution we have used the fundamental parameter (FP [1,2] method to evaluate the nanostructure materials assuming a theoretical model of experimental XRLP. In this contribution we have used various distribution functions such as normal, lognormal, Gumbel, Maxwell and Student. The best values of the crystallite size of nanostructued materials are chosen by analysis of root mean squares of residuals and by correlation matrix of the fit parameters. The entire procedure was implemented in the GnuPlot script.
The Pan-Pacific Planet Search V. Fundamental Parameters for 164 Evolved Stars
Wittenmyer, Robert A; Wang, Liang; Casagrande, Luca; Johnson, John Asher; Tinney, C G
2016-01-01
We present spectroscopic stellar parameters for the complete target list of 164 evolved stars from the Pan-Pacific Planet Search, a five-year radial velocity campaign using the 3.9m Anglo-Australian Telescope. For 87 of these bright giants, our work represents the first determination of their fundamental parameters. Our results carry typical uncertainties of 100 K, 0.15 dex, and 0.1 dex in $T_{\\rm eff}$, $\\log g$, and [Fe/H] and are consistent with literature values where available. The derived stellar masses have a mean of $1.31^{+0.28}_{-0.25}$ Msun, with a tail extending to $\\sim$2 Msun, consistent with the interpretation of these targets as "retired" A-F type stars.
A MACHINE-LEARNING METHOD TO INFER FUNDAMENTAL STELLAR PARAMETERS FROM PHOTOMETRIC LIGHT CURVES
Energy Technology Data Exchange (ETDEWEB)
Miller, A. A. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States); Bloom, J. S.; Richards, J. W.; Starr, D. L. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Lee, Y. S. [Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Butler, N. R. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85281 (United States); Tokarz, S. [Smithsonian Astrophysical Observatory, Cambridge, MA 02138 (United States); Smith, N.; Eisner, J. A., E-mail: amiller@astro.caltech.edu [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)
2015-01-10
A fundamental challenge for wide-field imaging surveys is obtaining follow-up spectroscopic observations: there are >10{sup 9} photometrically cataloged sources, yet modern spectroscopic surveys are limited to ∼few× 10{sup 6} targets. As we approach the Large Synoptic Survey Telescope era, new algorithmic solutions are required to cope with the data deluge. Here we report the development of a machine-learning framework capable of inferring fundamental stellar parameters (T {sub eff}, log g, and [Fe/H]) using photometric-brightness variations and color alone. A training set is constructed from a systematic spectroscopic survey of variables with Hectospec/Multi-Mirror Telescope. In sum, the training set includes ∼9000 spectra, for which stellar parameters are measured using the SEGUE Stellar Parameters Pipeline (SSPP). We employed the random forest algorithm to perform a non-parametric regression that predicts T {sub eff}, log g, and [Fe/H] from photometric time-domain observations. Our final optimized model produces a cross-validated rms error (RMSE) of 165 K, 0.39 dex, and 0.33 dex for T {sub eff}, log g, and [Fe/H], respectively. Examining the subset of sources for which the SSPP measurements are most reliable, the RMSE reduces to 125 K, 0.37 dex, and 0.27 dex, respectively, comparable to what is achievable via low-resolution spectroscopy. For variable stars this represents a ≈12%-20% improvement in RMSE relative to models trained with single-epoch photometric colors. As an application of our method, we estimate stellar parameters for ∼54,000 known variables. We argue that this method may convert photometric time-domain surveys into pseudo-spectrographic engines, enabling the construction of extremely detailed maps of the Milky Way, its structure, and history.
Fundamental parameter based quantification algorithm for confocal nano-X-ray fluorescence analysis
Energy Technology Data Exchange (ETDEWEB)
Schoonjans, Tom, E-mail: Tom.Schoonjans@UGent.be [X-ray Microspectroscopy and Imaging Research Group (XMI), Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000 Ghent (Belgium); Silversmit, Geert; Vekemans, Bart [X-ray Microspectroscopy and Imaging Research Group (XMI), Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000 Ghent (Belgium); Schmitz, Sylvia [Geosciences Institute/Mineralogy, Goethe University Frankfurt, Altenhoeferallee 1, D-60438 Frankfurt (Germany); Burghammer, Manfred; Riekel, Christian [ESRF, 6 rue Jules Horowitz, BP220, F-38043 Grenoble Cedex (France); Brenker, Frank E. [Geosciences Institute/Mineralogy, Goethe University Frankfurt, Altenhoeferallee 1, D-60438 Frankfurt (Germany); Vincze, Laszlo, E-mail: Laszlo.Vincze@UGent.be [X-ray Microspectroscopy and Imaging Research Group (XMI), Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000 Ghent (Belgium)
2012-01-15
A new method for the quantification of X-ray fluorescence (XRF) was derived based on the fundamental parameter method (FPM). The FPM equations were adapted to accommodate the special case of confocal nano-XRF, i.e. X-ray nano-beam excitation coupled with confocal detection, taking into account the special characteristics of the detector channel polycapillary. A thorough error estimation algorithm based on the Monte Carlo method was applied, producing a detailed analysis of the uncertainties of the quantification results. The new FPM algorithm was applied on confocal nano-XRF data obtained from cometary dust returned by NASA's Stardust mission, recorded at beamline ID13 of the European Synchrotron Radiation Facility. - Highlights: Black-Right-Pointing-Pointer A new method for the quantification of confocal XRF is presented. Black-Right-Pointing-Pointer The quantification is based on the fundamental parameter method (FPM). Black-Right-Pointing-Pointer The new FPM algorithm was applied for the analysis of unique cometary dust particles. Black-Right-Pointing-Pointer The cometary particles were returned by NASA's Stardust mission in 2006. Black-Right-Pointing-Pointer Error estimation is based on the Monte Carlo method.
VLTI/AMBER observations of cold giant stars: atmospheric structures and fundamental parameters
Arroyo-Torres, B; Marcaide, J M; Wittkowski, M; Guirado, J C; Hauschildt, P H; Quirrenbach, A; Fabregat, J
2014-01-01
The main goal of this research is to determine the angular size and the atmospheric structures of cool giant stars and to compare them with hydrostatic stellar model atmospheres, to estimate the fundamental parameters, and to obtain a better understanding of the circumstellar environment. We conducted spectro-interferometric observations of epsilon Oct, beta Peg, NU Pav, and psi Peg in the near-infrared K band (2.13-2.47 microm), and gamma Hya (1.9-2.47 microm) with the VLTI/AMBER instrument at medium spectral resolution. To obtain the fundamental parameters, we compared our data with hydrostatic atmosphere models (PHOENIX). We estimated the Rosseland angular diameters of epsilon Oct, beta Peg, NU Pav, psi Peg, and gamma Hya. Together with distances and bolometric fluxes, we estimated radii, effective temperatures, and luminosities of our targets. In the beta Peg visibility, we observed a molecular layer of CO with a size similar to that modeled with PHOENIX. However, there is an additional slope in absorptio...
Energy Technology Data Exchange (ETDEWEB)
Shaltout, Abdallah A., E-mail: shaltout_a@hotmail.com [Spectroscopy Department, Physics Division, National Research Center, El Behooth Str., 12622 Dokki, Cairo (Egypt); Faculty of science, Taif University, 21974 Taif, P.O. Box 888 (Saudi Arabia); Moharram, Mohammed A. [Spectroscopy Department, Physics Division, National Research Center, El Behooth Str., 12622 Dokki, Cairo (Egypt); Mostafa, Nasser Y. [Faculty of science, Taif University, 21974 Taif, P.O. Box 888 (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, Ismailia (Egypt)
2012-01-15
This work is the first attempt to quantify trace elements in the Catha edulis plant (Khat) with a fundamental parameter approach. C. edulis is a famous drug plant in east Africa and Arabian Peninsula. We have previously confirmed that hydroxyapatite represents one of the main inorganic compounds in the leaves and stalks of C. edulis. Comparable plant leaves from basil, mint and green tea were included in the present investigation as well as trifolium leaves were included as a non-related plant. The elemental analyses of the plants were done by Wavelength Dispersive X-Ray Fluorescence (WDXRF) spectroscopy. Standard-less quantitative WDXRF analysis was carried out based on the fundamental parameter approaches. According to the standard-less analysis algorithms, there is an essential need for an accurate determination of the amount of organic material in the sample. A new approach, based on the differential thermal analysis, was successfully used for the organic material determination. The obtained results based on this approach were in a good agreement with the commonly used methods. Depending on the developed method, quantitative analysis results of eighteen elements including; Al, Br, Ca, Cl, Cu, Fe, K, Na, Ni, Mg, Mn, P, Rb, S, Si, Sr, Ti and Zn were obtained for each plant. The results of the certified reference materials of green tea (NCSZC73014, China National Analysis Center for Iron and Steel, Beijing, China) confirmed the validity of the proposed method. - Highlights: Black-Right-Pointing-Pointer Quantitative analysis of Catha edulis was carried out using standardless WDXRF. Black-Right-Pointing-Pointer Differential thermal analysis was used for determination of the loss of ignition. Black-Right-Pointing-Pointer The existence of hydroxyapatite in Catha edulis plant has been confirmed. Black-Right-Pointing-Pointer The CRM results confirmed the validity of the developed method.
Aidelman, Y.; Cidale, L. S.; Zorec, J.; Panei, J. A.
2015-05-01
Context. The knowledge of accurate values of effective temperature, surface gravity, and luminosity of stars in open clusters is very important not only to derive cluster distances and ages but also to discuss the stellar structure and evolution. Unfortunately, stellar parameters are still very scarce. Aims: Our goal is to study five open clusters to derive stellar parameters of the B and Be star population and discuss the cluster properties. In a near future, we intend to gather a statistically relevant samples of Be stars to discuss their origin and evolution. Methods: We use the Barbier-Chalonge-Divan spectrophotometric system, based on the study of low-resolution spectra around the Balmer discontinuity, since it is independent of the interstellar and circumstellar extinction and provides accurate Hertzsprung-Russell diagrams and stellar parameters. Results: We determine stellar fundamental parameters, such as effective temperatures, surface gravities, spectral types, luminosity classes, absolute and bolometric magnitudes and colour gradient excesses of the stars in the field of Collinder 223, Hogg 16, NGC 2645, NGC 3114, and NGC 6025. Additional information, mainly masses and ages of cluster stellar populations, is obtained using stellar evolution models. In most cases, stellar fundamental parameters have been derived for the first time. We also discuss the derived cluster properties of reddening, age and distance. Conclusions: Collinder 223 cluster parameters are overline{E(B-V) = 0.25 ± 0.03} mag and overline{(mv - M_v)0 = 11.21 ± 0.25} mag. In Hogg 16, we clearly distinguish two groups of stars (Hogg 16a and Hogg 16b) with very different mean true distance moduli (8.91 ± 0.26 mag and 12.51 ± 0.38 mag), mean colour excesses (0.26 ± 0.03 mag and 0.63 ± 0.08 mag), and spectral types (B early-type and B late-/A-type stars, respectively). The farthest group could be merged with Collinder 272. NGC 2645 is a young cluster (<14 Myr) with overline{E(B-V) = 0
Automated estimation of stellar fundamental parameters from low resolution spectra: the PLS method
Institute of Scientific and Technical Information of China (English)
Jian-Nan Zhang; A-Li Luo; Yong-Heng Zhao
2009-01-01
PLS (Partial Least Squares regression) is introduced into an automatic esti-mation of fundamental stellar spectral parameters. It extracts the most correlative spec-tral component to the parameters (Teff, log g and [Fe/H]), and sets up a linear regres-sion function from spectra to the corresponding parameters. Considering the properties of stellar spectra and the PLS algorithm, we present a piecewise PLS regression method for estimation of stellar parameters, which is composed of one PLS model for Teff, and seven PLS models for log g and [Fe/H] estimation. Its performance is investigated by large experiments on flux calibrated spectra and continuum normalized spectra at dif-ferent signal-to-noise ratios (SNRs) and resolutions. The results show that the piecewise PLS method is robust for spectra at the medium resolution of 0.23 nm. For low resolu-tion 0.5 nm and 1 nm spectra, it achieves competitive results at higher SNR. Experiments using ELODIE spectra of 0.23 nm resolution illustrate that our piecewise PLS models trained with MILES spectra are efficient for O ～ G stars: for flux calibrated spectra, the systematic offsets are 3.8%, 0.14dex, and -0.09 dex for Teff, log g and [Fe/H], with error scatters of 5.2%, 0.44 dex and 0.38 dex, respectively; for continuum normalized spectra, the systematic offsets are 3.8%, 0.12dex, and -0.13 dex for Teff, log g and [Fe/H], with error scatters of 5.2%, 0.49 dex and 0.41 dex, respectively. The PLS method is rapid, easy to use and does not rely as strongly on the tightness of a parameter grid of templates to reach high precision as Artificial Neural Networks or minimum distance methods do.
The radius and other fundamental parameters of the F9 V star beta Virginis
North, J R; Robertson, J G; Bedding, T R; Bruntt, H; Ireland, M J; Jacob, A P; Lacour, S; O'Byrne, J W; Owens, S M; Stello, D; Tango, W J; Tuthill, P G
2008-01-01
We have used the Sydney University Stellar Interferometer (SUSI) to measure the angular diameter of the F9 V star beta Virginis. After correcting for limb darkening and combining with the revised Hipparcos parallax, we derive a radius of 1.703 +/- 0.022 R_sun (1.3%). We have also calculated the bolometric flux from published measurements which, combined with the angular diameter, implies an effective temperature of 6059 +/- 49 K (0.8%). We also derived the luminosity of beta Vir to be L = 3.51 +/- 0.08 L_sun (2.1%). Solar-like oscillations were measured in this star by Carrier et al. (2005) and using their value for the large frequency separation yields the mean stellar density with an uncertainty of about 2%. Our constraints on the fundamental parameters of beta Vir will be important to test theoretical models of this star and its oscillations.
Neilson, Hilding R; Norris, Ryan; Kloppenborg, Brian; Lester, John B
2016-01-01
One of the great challenges in understanding stars is measuring their masses. The best methods for measuring stellar masses include binary interaction, asteroseismology and stellar evolution models, but these methods are not ideal for red giant and supergiant stars. In this work, we propose a novel method for inferring stellar masses of evolved red giant and supergiant stars using interferometric and spectrophotometric observations combined with spherical model stellar atmospheres to measure what we call the stellar mass index, defined as the ratio between the stellar radius and mass. The method is based on the correlation between different measurements of angular diameter, used as a proxy for atmospheric extension, and fundamental stellar parameters. For a given star, spectrophotometry measures the Rosseland angular diameter while interferometric observations generally probe a larger limb-darkened angular diameter. The ratio of these two angular diameters is proportional to the relative extension of the stel...
Energy Technology Data Exchange (ETDEWEB)
Jeong, Hyunjo, E-mail: hjjeong@wku.ac.kr [Division of Mechanical and Automotive Engineering, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Zhang, Shuzeng; Li, Xiongbing [School of Traffic and Transportation Engineering, Central South University, Changsha, Hunan 410075 (China); Barnard, Dan [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50010 (United States)
2015-09-15
The accurate measurement of acoustic nonlinearity parameter β for fluids or solids generally requires making corrections for diffraction effects due to finite size geometry of transmitter and receiver. These effects are well known in linear acoustics, while those for second harmonic waves have not been well addressed and therefore not properly considered in previous studies. In this work, we explicitly define the attenuation and diffraction corrections using the multi-Gaussian beam (MGB) equations which were developed from the quasilinear solutions of the KZK equation. The effects of making these corrections are examined through the simulation of β determination in water. Diffraction corrections are found to have more significant effects than attenuation corrections, and the β values of water can be estimated experimentally with less than 5% errors when the exact second harmonic diffraction corrections are used together with the negligible attenuation correction effects on the basis of linear frequency dependence between attenuation coefficients, α{sub 2} ≃ 2α{sub 1}.
Accurate Frequency Estimation Based On Three-Parameter Sine-Fitting With Three FFT Samples
Directory of Open Access Journals (Sweden)
Liu Xin
2015-09-01
Full Text Available This paper presents a simple DFT-based golden section searching algorithm (DGSSA for the single tone frequency estimation. Because of truncation and discreteness in signal samples, Fast Fourier Transform (FFT and Discrete Fourier Transform (DFT are inevitable to cause the spectrum leakage and fence effect which lead to a low estimation accuracy. This method can improve the estimation accuracy under conditions of a low signal-to-noise ratio (SNR and a low resolution. This method firstly uses three FFT samples to determine the frequency searching scope, then – besides the frequency – the estimated values of amplitude, phase and dc component are obtained by minimizing the least square (LS fitting error of three-parameter sine fitting. By setting reasonable stop conditions or the number of iterations, the accurate frequency estimation can be realized. The accuracy of this method, when applied to observed single-tone sinusoid samples corrupted by white Gaussian noise, is investigated by different methods with respect to the unbiased Cramer-Rao Low Bound (CRLB. The simulation results show that the root mean square error (RMSE of the frequency estimation curve is consistent with the tendency of CRLB as SNR increases, even in the case of a small number of samples. The average RMSE of the frequency estimation is less than 1.5 times the CRLB with SNR = 20 dB and N = 512.
Accurate parameters for HD 209458 and its planet from HST spectrophotometry
del Burgo, C.; Allende Prieto, C.
2016-12-01
We present updated parameters for the star HD 209458 and its transiting giant planet. The stellar angular diameter θ = 0.2254 ± 0.0017 mas is obtained from the average ratio between the absolute flux observed with the Hubble Space Telescope and that of the best-fitting Kurucz model atmosphere. This angular diameter represents an improvement in precision of more than four times compared to available interferometric determinations. The stellar radius R⋆ = 1.20 ± 0.05 R⊙ is ascertained by combining the angular diameter with the Hipparcos trigonometric parallax, which is the main contributor to its uncertainty, and therefore the radius accuracy should be significantly improved with Gaia's measurements. The radius of the exoplanet Rp = 1.41 ± 0.06 RJ is derived from the corresponding transit depth in the light curve and our stellar radius. From the model fitting, we accurately determine the effective temperature, Teff = 6071 ± 20 K, which is in perfect agreement with the value of 6070 ± 24 K calculated from the angular diameter and the integrated spectral energy distribution. We also find precise values from recent Padova isochrones, such as R⋆ = 1.20 ± 0.06 R⊙ and Teff = 6099 ± 41 K. We arrive at a consistent picture from these methods and compare the results with those from the literature.
Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Poggialini, F.; Palleschi, V.
2016-10-01
In this paper, we present a discussion on three different methods recently proposed for the analysis of Laser-Induced Breakdown Spectroscopy (LIBS) spectra, namely the One-Point-Calibration, the Calibration-Free Inverse method, and the Csigma graphs approach. The common characteristics of these methods is the fact of being based on the main equations governing the emission of near-LTE plasmas, i.e. the same theoretical framework that is at the basis of the Calibration-Free LIBS analysis. However, with the purpose to guarantee a higher trueness in the analysis, these methods rely on the information obtained by the analysis of a single reference material, of known composition, for calculating the values of some experimental parameters that would be otherwise difficult to determine. In analogy with a similar approach used in the analysis of X-ray Fluorescence spectra, we place these techniques in the general framework of the so-called Fundamental Parameters Analysis. The three methods were tested and compared on LIBS spectra acquired on modern bronze samples. The advantages and drawbacks of the different approaches are discussed in detail.
DEFF Research Database (Denmark)
Kallinger, Thomas; Mosser, Benoit; Hekker, Saskia;
2010-01-01
Context. Clear power excess in a frequency range typical for solar-type oscillations in red giants has been detected in more than 1000 stars, which have been observed during the first 138 days of the science operation of the NASA Kepler satellite. This sample includes stars in a wide mass...... to the observed power density spectra, which allows us to accurately estimate the granulation background signal and the global oscillation parameters, such as the frequency of maximum oscillation power. We find regular patterns of radial and non-radial oscillation modes and use a new technique to automatically...... population. We find a mass and metallicity gradient in the red clump and clear evidence of a secondary-clump population....
Schönrich, Ralph; Bergemann, Maria
2014-09-01
We present a unified framework to derive fundamental stellar parameters by combining all available observational and theoretical information for a star. The algorithm relies on the method of Bayesian inference, which for the first time directly integrates the spectroscopic analysis pipeline based on the global spectrum synthesis and allows for comprehensive and objective error calculations given the priors. Arbitrary input data sets can be included into our analysis and other stellar quantities, in addition to stellar age, effective temperature, surface gravity, and metallicity, can be computed on demand. We lay out the mathematical framework of the method and apply it to several observational data sets, including high- and low-resolution spectra (UVES, NARVAL, HARPS, SDSS/SEGUE). We find that simpler approximations for the spectroscopic probability distribution function, which are inherent to past Bayesian approaches, lead to deviations of several standard deviations and unreliable errors on the same data. By its flexibility and the simultaneous analysis of multiple independent measurements for a star, it will be ideal to analyse and cross-calibrate the large ongoing and forthcoming surveys, like Gaia-European Southern Observatory (ESO), SDSS, Gaia and LSST.
\\gamma^2 Velorum: Orbital Solution and Fundamental Parameter Determination with SUSI
North, J R; Tango, W J; Davis, J
2007-01-01
The first complete orbital solution for the double-lined spectroscopic binary system \\gamma^2 Velorum, obtained from measurements with the Sydney University Stellar Interferometer (SUSI), is presented. This system contains the closest example of a Wolf-Rayet star and the promise of full characterisation of the basic properties of this exotic high-mass system has subjected it to intense study as an archetype for its class. In combination with the latest radial-velocity results, our orbital solution produces a distance of 336^{+8}_{-7} pc, significantly more distant than the Hipparcos estimation (Schaerer et al. 1997; van der Hucht 1997). The ability to fully specify the orbital parameters has enabled us to significantly reduce uncertainties and our result is consistent with the VLTI observational point (Millour et al. 2006), but not with their derived distance. Our new distance, which is an order of magnitude more precise than prior work, demands critical reassessment of all distance-dependent fundamental para...
The Fundamental Stellar Parameters of FGK Stars in the SEEDS Survey
Rich, Evan; Wisniewski, John P.; SEEDS Team
2017-01-01
Large exoplanet surveys have successfully detected thousands of exoplanets to-date. Utilizing these detections and non-detections to constrain our understanding of the formation and evolution of planetary systems also requires a detailed understanding of the basic properties of their host stars. We have determined the basic stellar properties of F, K, and G stars in the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey from echelle spectra taken at the Apache Point Observatory's 3.5m telescope. Using ROBOSPECT to extract line fluxes and TGVIT to calculate the fundamental parameters, we have computed Teff, log(g), vt, [Fe/H], chromospheric activity, lithium abundance, and the age for our sample. Our methodology was calibrated against previously published results for a portion of our sample. The future meta-analysis of the results of the SEEDS survey will utilize our results to constrain the occurrence of detected co-moving companions with the properties of their host stars.
Fundamental approaches for analysis thermal hydraulic parameter for Puspati Research Reactor
Energy Technology Data Exchange (ETDEWEB)
Hashim, Zaredah, E-mail: zaredah@nm.gov.my; Lanyau, Tonny Anak, E-mail: tonny@nm.gov.my; Farid, Mohamad Fairus Abdul; Kassim, Mohammad Suhaimi [Reactor Technology Centre, Technical Support Division, Malaysia Nuclear Agency, Ministry of Science, Technology and Innovation, Bangi, 43000, Kajang, Selangor Darul Ehsan (Malaysia); Azhar, Noraishah Syahirah [Universiti Teknologi Malaysia, 80350, Johor Bahru, Johor Darul Takzim (Malaysia)
2016-01-22
The 1-MW PUSPATI Research Reactor (RTP) is the one and only nuclear pool type research reactor developed by General Atomic (GA) in Malaysia. It was installed at Malaysian Nuclear Agency and has reached the first criticality on 8 June 1982. Based on the initial core which comprised of 80 standard TRIGA fuel elements, the very fundamental thermal hydraulic model was investigated during steady state operation using the PARET-code. The main objective of this paper is to determine the variation of temperature profiles and Departure of Nucleate Boiling Ratio (DNBR) of RTP at full power operation. The second objective is to confirm that the values obtained from PARET-code are in agreement with Safety Analysis Report (SAR) for RTP. The code was employed for the hot and average channels in the core in order to calculate of fuel’s center and surface, cladding, coolant temperatures as well as DNBR’s values. In this study, it was found that the results obtained from the PARET-code showed that the thermal hydraulic parameters related to safety for initial core which was cooled by natural convection was in agreement with the designed values and safety limit in SAR.
Effective Temperatures of Selected Main-sequence Stars with Most Accurate Parameters
Soydugan, F; Soydugan, E; Bilir, S; Gökçe, E Yaz; Steer, I; Tüysüz, M; Şenyüz, T; Demircan, O
2014-01-01
In this study, the distributions of the double-lined detached binaries (DBs) on the planes of mass-luminosity, mass radius and mass-effective temperature have been studied. We improved the classical mass-luminosity relation based on the database of DBs by Eker et al. (2004a). With accurate observational data available to us, a method for improving effective temperatures for eclipsing binaries with accurate masses and radii were suggested.
Effective Temperatures of Selected Main-Sequence Stars with the Most Accurate Parameters
Soydugan, F.; Eker, Z.; Soydugan, E.; Bilir, S.; Gökçe, E. Y.; Steer, I.; Tüysüz, M.; Šenyüz, T.; Demircan, O.
2015-07-01
In this study we investigate the distributions of the properties of detached double-lined binaries (DBs) in the mass-luminosity, mass-radius, and mass-effective temperature diagrams. We have improved the classical mass-luminosity relation based on the database of DBs by Eker et al. (2014a). Based on the accurate observational data available to us we propose a method for improving the effective temperatures of eclipsing binaries with accurate mass and radius determinations.
Thygesen, A O; Andrievsky, S; Korotin, S; Yong, D; Zaggia, S; Ludwig, H -G; Collet, R; Asplund, M; D'Antona, F; Meléndez, J; D'Ercole, A
2014-01-01
Context: The study of chemical abundance patterns in globular clusters is of key importance to constrain the different candidates for intra-cluster pollution of light elements. Aims: We aim at deriving accurate abundances for a large range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Methods: Using tailored 1D LTE atmospheric models together with a combination of equivalent width measurements, LTE, and NLTE synthesis we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. Results: We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al and Ba. We find a mean [Fe/H] = $-0.78\\pm0.07$ and $[\\alpha/{\\rm Fe}]=0.34\\pm0.03$ in...
Dahms, Rainer N
2015-05-01
The fidelity of Gradient Theory simulations depends on the accuracy of saturation properties and influence parameters, and require equations of state (EoS) which exhibit a fundamentally consistent behavior in the two-phase regime. Widely applied multi-parameter EoS, however, are generally invalid inside this region. Hence, they may not be fully suitable for application in concert with Gradient Theory despite their ability to accurately predict saturation properties. The commonly assumed temperature-dependence of pure component influence parameters usually restricts their validity to subcritical temperature regimes. This may distort predictions for general multi-component interfaces where temperatures often exceed the critical temperature of vapor phase components. Then, the calculation of influence parameters is not well defined. In this paper, one of the first studies is presented in which Gradient Theory is combined with a next-generation Helmholtz energy EoS which facilitates fundamentally consistent calculations over the entire two-phase regime. Illustrated on pentafluoroethane as an example, reference simulations using this method are performed. They demonstrate the significance of such high-accuracy and fundamentally consistent calculations for the computation of interfacial properties. These reference simulations are compared to corresponding results from cubic PR EoS, widely-applied in combination with Gradient Theory, and mBWR EoS. The analysis reveals that neither of those two methods succeeds to consistently capture the qualitative distribution of obtained key thermodynamic properties in Gradient Theory. Furthermore, a generalized expression of the pure component influence parameter is presented. This development is informed by its fundamental definition based on the direct correlation function of the homogeneous fluid and by presented high-fidelity simulations of interfacial density profiles. The new model preserves the accuracy of previous temperature
Energy Technology Data Exchange (ETDEWEB)
Ghezzi, Luan; Da Costa, Luiz N.; Maia, Marcio A. G.; Ogando, Ricardo L. C. [Observatório Nacional, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); Dutra-Ferreira, Letícia; Lorenzo-Oliveira, Diego; Porto de Mello, Gustavo F.; Santiago, Basílio X. [Laboratório Interinstitucional de e-Astronomia - LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); De Lee, Nathan [Department of Physics and Geology, Northern Kentucky University, Highland Heights, KY 41099 (United States); Lee, Brian L.; Ge, Jian [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Wisniewski, John P. [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks St Norman, OK 73019 (United States); González Hernández, Jonay I. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Stassun, Keivan G.; Cargile, Phillip; Pepper, Joshua [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Fleming, Scott W. [Space Telescope Science Institute - STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Schneider, Donald P.; Mahadevan, Suvrath [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Wang, Ji, E-mail: luan@linea.gov.br [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); and others
2014-12-01
Studies of Galactic chemical, and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (effective temperature T {sub eff}, metallicity [Fe/H], and surface gravity log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. Therefore, most surveys employ spectral synthesis, which is a powerful technique, but relies heavily on the completeness and accuracy of atomic line databases and can yield possibly correlated atmospheric parameters. In this work, we use an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R ∼ 12,000). To avoid a time-consuming manual analysis, we have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices, and, through a comparison of those with values calculated with predetermined calibrations, estimate the atmospheric parameters of the stars. The calibrations were derived using a sample of 309 stars with precise stellar parameters obtained from the analysis of high-resolution FEROS spectra, permitting the low-resolution equivalent widths to be directly related to the stellar parameters. A validation test of the method was conducted with a sample of 30 MARVELS targets that also have reliable atmospheric parameters derived from the high-resolution spectra and spectroscopic analysis based on the excitation and ionization equilibria method. Our approach was able to recover the parameters within 80 K for T {sub eff}, 0.05 dex for [Fe/H], and 0.15 dex for log g, values that are lower than or equal to the typical external uncertainties found between different high-resolution analyses. An
Ghezzi, Luan; Lorenzo-Oliveira, Diego; de Mello, Gustavo F Porto; Santiago, Basílio X; De Lee, Nathan; Lee, Brian L; da Costa, Luiz N; Maia, Marcio A G; Ogando, Ricardo L C; Wisniewski, John P; Hernández, Jonay I González; Stassun, Keivan G; Fleming, Scott W; Schneider, Donald P; Mahadevan, Suvrath; Cargile, Phillip; Ge, Jian; Pepper, Joshua; Wang, Ji
2014-01-01
Studies of Galactic chemical and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. While most surveys use spectral synthesis, in this work we employ an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R~12,000). We have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices and, through the comparison of those with values calculated with pre-determined calibrations, derive the atmospheric parameters of the stars. The calibrations were built using a sample of 309 stars with p...
Energy Technology Data Exchange (ETDEWEB)
Schwob, C
2006-12-15
This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm{sup -1}). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10{sup -9} began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is {alpha}{sub -1} = 137.03599884 (91) with a relative uncertainty of 6.7*10{sup -9}. The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)
Goudar, Chetan T
2011-10-01
We have identified an error in the published integral form of the modified Michaelis-Menten equation that accounts for endogenous substrate production. The correct solution is presented and the error in both the substrate concentration, S, and the kinetic parameters Vm , Km , and R resulting from the incorrect solution was characterized. The incorrect integral form resulted in substrate concentration errors as high as 50% resulting in 7-50% error in kinetic parameter estimates. To better reflect experimental scenarios, noise containing substrate depletion data were analyzed by both the incorrect and correct integral equations. While both equations resulted in identical fits to substrate depletion data, the final estimates of Vm , Km , and R were different and Km and R estimates from the incorrect integral equation deviated substantially from the actual values. Another observation was that at R = 0, the incorrect integral equation reduced to the correct form of the Michaelis-Menten equation. We believe this combination of excellent fits to experimental data, albeit with incorrect kinetic parameter estimates, and the reduction to the Michaelis-Menten equation at R = 0 is primarily responsible for the incorrectness to go unnoticed. However, the resulting error in kinetic parameter estimates will lead to incorrect biological interpretation and we urge the use of the correct integral form presented in this study.
Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited
Energy Technology Data Exchange (ETDEWEB)
Fogtmann-Schulz, Alexandra; Hinrup, Brian; Van Eylen, Vincent; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Silva Aguirre, Víctor; Tingley, Brandon, E-mail: alfosc@phys.au.dk [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
2014-02-01
Since the discovery of Kepler-10, the system has received considerable interest because it contains a small, rocky planet which orbits the star in less than a day. The system's parameters, announced by the Kepler team and subsequently used in further research, were based on only five months of data. We have reanalyzed this system using the full span of 29 months of Kepler photometric data, and obtained improved information about its star and the planets. A detailed asteroseismic analysis of the extended time series provides a significant improvement on the stellar parameters: not only can we state that Kepler-10 is the oldest known rocky-planet-harboring system at 10.41 ± 1.36 Gyr, but these parameters combined with improved planetary parameters from new transit fits gives us the radius of Kepler-10b to within just 125 km. A new analysis of the full planetary phase curve leads to new estimates on the planetary temperature and albedo, which remain degenerate in the Kepler band. Our modeling suggests that the flux level during the occultation is slightly lower than at the transit wings, which would imply that the nightside of this planet has a non-negligible temperature.
Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited
Fogtmann-Schulz, Alexandra; Van Eylen, Vincent; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Aguirre, Víctor Silva; Tingley, Brandon
2013-01-01
Since the discovery of Kepler-10, the system has received considerable interest because it contains a small, rocky planet which orbits the star in less than a day. The system's parameters, announced by the Kepler team and subsequently used in further research, were based on only 5 months of data. We have reanalyzed this system using the full span of 29 months of Kepler photometric data, and obtained improved information about its star and the planets. A detailed asteroseismic analysis of the extended time series provides a significant improvement on the stellar parameters: Not only can we state that Kepler-10 is the oldest known rocky-planet-harboring system at 10.41 +/- 1.36 Gyr, but these parameters combined with improved planetary parameters from new transit fits gives us the radius of Kepler-10b to within just 125 km. A new analysis of the full planetary phase curve leads to new estimates on the planetary temperature and albedo, which remain degenerate in the Kepler band. Our modeling suggests that the fl...
Institute of Scientific and Technical Information of China (English)
TANG Yi; FANG Yong-li; YANG Luo; SUN Yu-xin; YU Zheng-hua
2012-01-01
A new accurate calculation method of electric power harmonic parameters was presented.Based on the delay time theorem of Fourier transform,the frequency of the electric power was calculated,and then,suing interpolation in the frequency domain of the windows,the parameters (amplitude and phase) of each harmonic frequency signals were calculated accurately.In the paper,the effect of the delay time and the windows on the electric power harmonic calculation accuracy was analysed.The digital simulation and the physical measurement tests show that the proposed method is effective and has more advantages than other methods which are based on multipoint interpolation especially in calculation time cost; therefore,it is very suitable to be used in the single chip DSP micro-processor.
Accurate nuclear masses from a three parameter Kohn-Sham DFT approach (BCPM)
Baldo, M; Schuck, P; Viñas, X
2012-01-01
Given the promising features of the recently proposed Barcelona-Catania-Paris (BCP) functional \\cite{Baldo.08}, it is the purpose of this paper to still improve on it. It is, for instance, shown that the number of open parameters can be reduced from 4-5 to 2-3, i.e. by practically a factor of two. One parameter is tightly fixed by a fine-tuning of the bulk, a second by the surface energy. The third is the strength of the spin-orbit potential on which the final result does not depend within the scatter of the values used in Skyrme and Gogny like functionals. An energy rms value of 1.58 MeV is obtained from a fit of these three parameters to the 579 measured masses reported in the Audi and Waspra 2003 compilation. This rms value compares favorably with the one obtained using other successful mean field theories. Charge radii are also well reproduced when compared with experiment. The energies of some excited states, mostly the isoscalar giant monopole resonances, are studied within this model as well.
2016-01-01
The right to education, despite being present in the Brazilian legislation, still suffers on being applied. This article deals with the dimensions of the education quality, which are at the same time understandable to the population and judicially enforceable. It analyzes the relevant legislation, and based on different authors, discusses the fundamental right to education and the pattern of the quality in Student Cost Initial Quality (CAQi) in Portuguese acronym). It also discusses the righ...
Accurate parameter estimation for star formation history in galaxies using SDSS spectra
Richards, Joseph W; Lee, Ann B; Schafer, Chad M
2009-01-01
To further our knowledge of the complex physical process of galaxy formation, it is essential that we characterize the formation and evolution of large databases of galaxies. The spectral synthesis STARLIGHT code of Cid Fernandes et al. (2004) was designed for this purpose. Results of STARLIGHT are highly dependent on the choice of input basis of simple stellar population (SSP) spectra. Speed of the code, which uses random walks through the parameter space, scales as the square of the number of basis spectra, making it computationally necessary to choose a small number of SSPs that are coarsely sampled in age and metallicity. In this paper, we develop methods based on diffusion map (Lafon & Lee, 2006) that, for the first time, choose appropriate bases of prototype SSP spectra from a large set of SSP spectra designed to approximate the continuous grid of age and metallicity of SSPs of which galaxies are truly composed. We show that our techniques achieve better accuracy of physical parameter estimation for...
An Accurate and Generic Testing Approach to Vehicle Stability Parameters Based on GPS and INS
Directory of Open Access Journals (Sweden)
Zhibin Miao
2015-12-01
Full Text Available With the development of the vehicle industry, controlling stability has become more and more important. Techniques of evaluating vehicle stability are in high demand. As a common method, usually GPS sensors and INS sensors are applied to measure vehicle stability parameters by fusing data from the two system sensors. Although prior model parameters should be recognized in a Kalman filter, it is usually used to fuse data from multi-sensors. In this paper, a robust, intelligent and precise method to the measurement of vehicle stability is proposed. First, a fuzzy interpolation method is proposed, along with a four-wheel vehicle dynamic model. Second, a two-stage Kalman filter, which fuses the data from GPS and INS, is established. Next, this approach is applied to a case study vehicle to measure yaw rate and sideslip angle. The results show the advantages of the approach. Finally, a simulation and real experiment is made to verify the advantages of this approach. The experimental results showed the merits of this method for measuring vehicle stability, and the approach can meet the design requirements of a vehicle stability controller.
Hansen, D Flemming; Westler, William M; Kunze, Micha B A; Markley, John L; Weinhold, Frank; Led, Jens J
2012-03-14
A natural bond orbital (NBO) analysis of unpaired electron spin density in metalloproteins is presented, which allows a fast and robust calculation of paramagnetic NMR parameters. Approximately 90% of the unpaired electron spin density occupies metal-ligand NBOs, allowing the majority of the density to be modeled by only a few NBOs that reflect the chemical bonding environment. We show that the paramagnetic relaxation rate of protons can be calculated accurately using only the metal-ligand NBOs and that these rates are in good agreement with corresponding rates measured experimentally. This holds, in particular, for protons of ligand residues where the point-dipole approximation breaks down. To describe the paramagnetic relaxation of heavy nuclei, also the electron spin density in the local orbitals must be taken into account. Geometric distance restraints for (15)N can be derived from the paramagnetic relaxation enhancement and the Fermi contact shift when local NBOs are included in the analysis. Thus, the NBO approach allows us to include experimental paramagnetic NMR parameters of (15)N nuclei as restraints in a structure optimization protocol. We performed a molecular dynamics simulation and structure determination of oxidized rubredoxin using the experimentally obtained paramagnetic NMR parameters of (15)N. The corresponding structures obtained are in good agreement with the crystal structure of rubredoxin. Thus, the NBO approach allows an accurate description of the geometric structure and the dynamics of metalloproteins, when NMR parameters are available of nuclei in the immediate vicinity of the metal-site.
Variation of fundamental parameters and dark energy. A principal component approach
Amendola, L; Martins, C J A P; Nunes, N J; Pedrosa, P O J; Seganti, A
2011-01-01
We discuss methods based on Principal Component Analysis for reconstructing the dark energy equation of state and constraining its evolution, using a combination of Type Ia supernovae at low redshift and spectroscopic measurements of varying fundamental couplings at higher redshifts. We discuss the performance of this method when future better-quality datasets are available, focusing on two forthcoming ESO spectrographs -- ESPRESSO for the VLT and CODEX for the E-ELT -- which include these measurements as a key part of their science cases. These can realize the prospect of a detailed characterization of dark energy properties all the way up to redshift 4.
A revision of the fundamental parameters of the open cluster Hogg 15 and the projected star WR 47
Piatti, A. E.; Bica, E.; Santos, J. F. C., Jr.; Clariá, J. J.
2002-05-01
We revise the fundamental parameters of the faint open cluster Hogg 15, for which two recent colour-magnitude diagram (CMD) studies have obtained significantly different ages. In the present study, we combine a series of methods trying to constrain age, together with other fundamental parameters. We employ spatial extractions to construct the CMDs, and the cluster integrated spectrum to compare it with those of templates of known age. We derive fundamental parameters, in particular, distance, of the closely projected Wolf-Rayet star HDE 311884 (WR 47) - often proposed to be physically related to Hogg 15. Based on the WR 47 spectrum and available photometry, we conclude that the short distance implied by the Hipparcos parallax (216 pc) is affected by binary motion. From the WR 47 spectrum we estimate a reddening E(B-V) and a distance of 1.10 +/- 0.05 and 5.2 +/- 0.9 kpc, respectively. For Hogg 15 we derive an age of 20 +/- 10 Myr, a reddening of 1.10 +/- 0.05, and a distance of 3.1 +/- 0.5 kpc. We conclude that Hogg 15 is not related to WR 47 from the point of view of origin, since the cluster and the star do not belong to the same formation event.
Bonatto, Charles; Lima, Eliade F
2011-01-01
We present an approach that improves the search for reliable astrophysical parameters (e.g. age, mass, and distance) of differentially-reddened, pre-main sequence-rich star clusters. It involves simulating conditions related to the early-cluster phases, in particular the differential and foreground reddenings, and internal age spread. Given the loose constraints imposed by these factors, the derivation of parameters based only on photometry may be uncertain, especially for the poorly-populated clusters. We consider a wide range of cluster {\\em (i)} mass and {\\em (ii)} age, and different values of {\\em (iii)} distance modulus, {\\em (iv)} differential and {\\em (v)} foreground reddenings. Photometric errors and their relation with magnitude are also taken into account. We also investigate how the presence of unresolved binaries affect the derived parameters. For each set of {\\em (i)} - {\\em (v)} we build the corresponding model Hess diagram, and compute the root mean squared residual with respect to the observed...
Fundamental stellar and accretion disc parameters of the eclipsing binary DQ Velorum
Barría, D; Schmidtobreick, L; Djurasević, G; Kołaczkowski, Z; Michalska, G; Vucković, M; Niemczura, E; 10.1051/0004-6361/201220230
2013-01-01
To add to the growing collection of well-studied double periodic variables (DPVs) we have carried out the first spectroscopic and photometric analysis of the eclipsing binary DQ Velorum to obtain its main physical stellar and orbital parameters. Combining spectroscopic and photometric observations that cover several orbital cycles allows us to estimate the stellar properties of the binary components and the orbital parameters. We also searched for circumstellar material around the more massive star. We separated DQ Velorum composite spectra and measured radial velocities with an iterative method for double spectroscopic binaries. We obtained the radial velocity curves and calculated the spectroscopic mass ratio. We compared our single-lined spectra with a grid of synthetic spectra and estimated the temperature of the stars. We modeled the V-band light curve with a fitting method based on the simplex algorithm, which includes an accretion disc. To constrain the main stellar parameters we fixed the mass ratio a...
Gargiulo, A; Merluzzi, P; Smith, R J; La Barbera, F; Busarello, G; Lucey, J R; Mercurio, A; Capaccioli, M
2009-01-01
We present a fundamental plane (FP) analysis of 141 early-type galaxies in the Shapley supercluster at z=0.049 based on spectroscopy from the AAOmega spectrograph at the AAT and photometry from the WFI on the ESO/MPI 2.2m telescope. The key feature of the survey is its coverage of low-mass galaxies down to sigma_0~50km/s. We obtain a best-fitting FP relation log r_e=1.06 log sigma_0 - 0.82 log _e + cst in the R band. The shallow exponent of sigma_0 is a result of the extension of our sample to low velocity dispersions. We investigate the origin of the intrinsic FP scatter, using estimates of age, metallicity and alpha/Fe. We find that the FP residuals anti-correlate (>3sigma) with the mean stellar age in agreement with previous work. However, a stronger (>4sigma) correlation with alpha/Fe is also found. These correlations indicate that galaxies with effective radii smaller than those predicted by the FP have stellar populations systematically older and with alpha over-abundances larger than average, for their...
Reconstructing the evolution of dark energy with variations of fundamental parameters
Nunes, N J; Martins, C J A P; Robbers, G
2009-01-01
Under the assumption that the variations of parameters of nature and the current acceleration of the universe are related and governed by the evolution of a single scalar field, we show how information can be obtained on the nature of dark energy from observational detection of (or constraints on) cosmological variations of the fine structure constant and the proton-to-electron mass ratio. We also comment on the current observational status, and on the prospects for improvements with future spectrographs such as ESPRESSO and CODEX.
The fundamental parameters of the roAp star alpha Circini
Bruntt, H; Cunha, M; Brandao, I M; Elkin, V G; Kurtz, D W; Davis, J; Bedding, T R; Jacob, A P; Owens, S M; Robertson, J G; Tango, W J; Gameiro, J F; Ireland, M J; Tuthill, P G
2008-01-01
We have used the Sydney University Stellar Interferometer (SUSI) to measure the angular diameter of alpha Cir. This is the first detailed interferometric study of a rapidly oscillating A (roAp) star, alpha Cir being the brightest member of its class. We used the new and more accurate Hipparcos parallax to determine the radius to be 1.967+-0.066 Rs. We have constrained the bolometric flux from calibrated spectra to determine an effective temperature of 7420+-170 K. This is the first direct determination of the temperature of an roAp star. Our temperature is at the low end of previous estimates, which span over 1000 K and were based on either photometric indices or spectroscopic methods. In addition, we have analysed two high-quality spectra of alpha Cir, obtained at different rotational phases and we find evidence for the presence of spots. In both spectra we find nearly solar abundances of C, O, Si, Ca and Fe, high abundance of Cr and Mn, while Co, Y, Nd and Eu are overabundant by about 1 dex. The results rep...
The Solar Twin Planet Search. I. Fundamental parameters of the stellar sample
Ramirez, I; Bean, J; Asplund, M; Bedell, M; Monroe, T; Casagrande, L; Schirbel, L; Dreizler, S; Teske, J; Maia, M Tucci; Alves-Brito, A; Baumann, P
2014-01-01
We are carrying out a search for planets around a sample of solar twin stars using the HARPS spectrograph. The goal of this project is to exploit the advantage offered by solar twins to obtain chemical abundances of unmatched precision. This survey will enable new studies of the stellar composition -- planet connection. Here we used the MIKE spectrograph on the Magellan Clay Telescope to acquire high resolution, high signal-to-noise ratio spectra of our sample stars. We measured the equivalent widths of iron lines and used strict differential excitation/ionization balance analysis to determine atmospheric parameters of unprecedented internal precision (DTeff=7K, Dlogg=0.019, D[Fe/H]=0.006dex, Dvt=0.016km/s). Reliable relative ages and highly precise masses were then estimated using theoretical isochrones. The spectroscopic parameters we derived are in good agreement with those measured using other independent techniques. The root-mean-square scatter of the differences seen is fully compatible with the observa...
Experimental and Theoretical He-BROADENED Line Parameters of Carbon Monoxide in the Fundamental Band
Predoi-Cross, Adriana; Rosario, Hoimonti; Esteki, Koorosh; Latif, Shamria; Naseri, Hossein; Thibault, Franck; Devi, V. Malathy; Smith, Mary Ann H.; Mantz, Arlan
2016-06-01
We report experimental measurements and theoretical calculations for He-broadened Lorentz half-width coefficients and He- pressure-shift coefficients of 45 carbon monoxide transitions in the 1-0 band. The high-resolution spectra analyzed in this study were recorded over a range of sample temperatures between 296 and 80 K. The He-broadened line parameters and their temperature dependences were retrieved using a multispectrum nonlinear least squares analysis program. A previous analysis of these spectra used only the Voigt line shape. In the present study four line shape models were compared including Voigt, speed dependent Voigt, Rautian (to take into account confinement narrowing) and Rautian with speed dependence. The line mixing coefficients have been calculated using the Exponential Power Gap scaling law. We were unable to retrieve the temperature dependence of the line mixing coefficients. The current measurements and theoretical results are compared with other published results, where appropriate. A. W. Mantz et al., J. Molec. Structure 742 (2005) 99-110
Fundamental stellar parameters of $\\zeta$ Pup and $\\gamma^2$ Vel from HIPPARCOS data
Schärer, D; Grenon, Michel; Schaerer, Daniel; Schmutz, Werner; Grenon, Michel
1997-01-01
We report parallax measurements by the HIPPARCOS satellite of zeta Puppis and gamma^2 Velorum. The distance of zeta Pup is d=429 (+120/ -77) pc, in agreement with the commonly adopted value to Vela OB2. However, a significantly smaller distance is found for the gamma^2 Vel system: d=258 (+41/-31) pc. The total mass of gamma^2 Vel derived from its parallax, the angular size of the semi-major axis as measured with intensity interferometry, and the period is M(WR+O)=29.5 (+/-15.9) Msun. This result favors the orbital solution of Pike et al. (1983) over that of Moffat et al. (1986). The stellar parameters for the O star companion derived from line blanketed non-LTE atmosphere models are: Teff=34000 (+/-1500) K, log L/Lsun=5.3 (+/-0.15) from which an evolutionary mass of M=29 (+/-4) Msun and an age of 4.0 (+0.8/-0.5) Myr is obtained from single star evolutionary models. With non-LTE model calculations including He and C we derive a luminosity log L/Lsun~4.7 (+/-0.2) for the WR star. The mass-luminosity relation of...
Iorio, Lorenzo
2016-01-01
By using the most recently published Doppler tomography measurements and accurate theoretical modeling of the oblateness-driven orbital precessions, we tightly constrain some of the physical and orbital parameters of the planetary system hosted by the fast rotating star WASP-33. In particular, the measurements of the orbital inclination $i_{\\rm p}$ to the plane of the sky and of the sky-projected spin-orbit misalignment $\\lambda$ at two epochs six years apart allowed for the determination of the longitude of the ascending node $\\Omega$ and of the orbital inclination $I$ to the apparent equatorial plane at the same epochs. As a consequence, average rates of change $\\dot\\Omega_{\\rm exp},~\\dot I_{\\rm exp}$ of this two orbital elements, accurate to a $\\approx 10^{-2}~\\textrm{deg}~\\textrm{yr}^{-1}$ level, were calculated as well. By comparing them to general theoretical expressions $\\dot\\Omega_{J_2},~\\dot I_{J_2}$ for their precessions induced by an arbitrarily oriented quadrupole mass moment, we were able to dete...
Institute of Scientific and Technical Information of China (English)
COHN William S.; LU Guo Zhen
2002-01-01
We derive the explicit fundamental solutions for a class of degenerate (or singular) oneparameter subelliptic differential operators on groups of Heisenberg (H) type. This extends the result of Kaplan for the sub-Laplacian on H-type groups, which in turn generalizes Folland's result on the Heisenberg group. As an application, we obtain a one-parameter representation formula for Sobolev functions of compact support on H-type groups. By choosing the parameter equal to the homogeneous dimension Q and using the Moser-Trudinger inequality for the convolutional type operator on stratified groups obtained in [18], we get the following theorem which gives the best constant for the MoserTrudinger inequality for Sobolev functions on H-type groups.Let G be any group of Heisenberg type whose Lie algebra is generated by m left invariant vectorfields and with a q-dimensional center. Let Q = m + 2q, Q′= Q/Q-1 andAQ= [(1/4)q-1/2πq+m/2Γ(Q+m/4)/ QΓ(m/2)Γ(Q/2)] 1/Q-1Then,F∈sup C∞U(Ω) { 1/|Ω|∫Ωexp (AQ(F(u)/‖ GF‖Q)Q′)du}＜∞,with AQ as the sharp constant, where G denotes the subelliptic gradient on G.This continues the research originated in our earlier study of the best constants in Moser-Teudinger inequalities and fundamental solutions for one-parameter subelliptic operators on the Heisenberg group[18].
Qiao, Yao-Bin; Qi, Hong; Zhao, Fang-Zhou; Ruan, Li-Ming
2016-12-01
Reconstructing the distribution of optical parameters in the participating medium based on the frequency-domain radiative transfer equation (FD-RTE) to probe the internal structure of the medium is investigated in the present work. The forward model of FD-RTE is solved via the finite volume method (FVM). The regularization term formatted by the generalized Gaussian Markov random field model is used in the objective function to overcome the ill-posed nature of the inverse problem. The multi-start conjugate gradient (MCG) method is employed to search the minimum of the objective function and increase the efficiency of convergence. A modified adjoint differentiation technique using the collimated radiative intensity is developed to calculate the gradient of the objective function with respect to the optical parameters. All simulation results show that the proposed reconstruction algorithm based on FD-RTE can obtain the accurate distributions of absorption and scattering coefficients. The reconstructed images of the scattering coefficient have less errors than those of the absorption coefficient, which indicates the former are more suitable to probing the inner structure. Project supported by the National Natural Science Foundation of China (Grant No. 51476043), the Major National Scientific Instruments and Equipment Development Special Foundation of China (Grant No. 51327803), and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51121004).
Perraut, K.; Brandão, I.; Cunha, M.; Shulyak, D.; Mourard, D.; Nardetto, N.; ten Brummelaar, T. A.
2016-05-01
Context. There is still a debate about the nature of the mechanism that causes the pulsation excitation of the rapidly oscillating Ap stars that oscillate above the highest theoretically acoustic frequency. HD 24712 is a good test case for such a study because it is bright, its parallax accurately determined, and its frequency spectrum is well known. Aims: Visible long-baseline interferometry is a unique technique for measuring accurate angular diameters of targets as small as the brightest roAp stars, and thus estimating accurate radii by a method as independent as possible of atmosphere models. Methods: We used the visible spectrograph VEGA at the CHARA long-baseline optical array to observe HD 24712, and we derived its limb-darkened diameter. We also estimated its bolometric flux from spectroscopic data in the literature and determined its radius, luminosity, and effective temperature. Results: We determined a limb-darkened angular diameter of 0.335 ± 0.009 mas for HD 24712 and derived a radius of R = 1.772 ± 0.057 R⊙, a luminosity of L = 7.2 ± 1.8 L⊙, and an effective temperature of Teff = 7235 ± 280 K, which is in very close agreement with the values provided by the self-consistent stratified model developed for this star. We used these fundamental parameters to set HD 24712 in the Hertzsprung-Russell diagram. Its position is marginally consistent with the region where high radial order modes are predicted to be excited by the κ-mechanism. Conclusions: We conclude that oscillations in this star are most likely not driven by the κ-mechanism. Based on observations made with the VEGA/CHARA spectro-interferometer.
Indian Academy of Sciences (India)
Lalita Gupta; S Rath; S C Abbi; F C Jain
2003-10-01
Thin ﬁlms of ternary ZnCd1-Se were deposited on GaAs (100) substrate using metal-organic-chemical-vapour-deposition (MOCVD) technique. Temperature dependence of the near-band-edge emission from these Cd-rich Zn Cd1-Se (for = 0.025, 0.045) ﬁlms has been studied using photoluminescence spectroscopy. Relevant parameters that describe temperature variation of the energy and broadening of the fundamental band gap have been evaluated using various models including the two-oscillator model, the Bose–Einstein model and the Varshni model. While all these models sufﬁce to explain spectra at higher temperatures, the two-oscillator model not only explains low temperature spectra adequately but also provides additional information concerning phonon dispersion in these materials.
Monteiro, H.; Dias, W. S.; Hickel, G. R.; Caetano, T. C.
2017-02-01
In the second paper of the series we continue the investigation of open cluster fundamental parameters using a robust global optimization method to fit model isochrones to photometric data. We present optical UBVRI CCD photometry (Johnsons-Cousins system) observations for 24 neglected open clusters, of which 14 have high quality data in the visible obtained for the first time, as a part of our ongoing survey being carried out in the 0.6 m telescope of the Pico dos Dias Observatory in Brazil. All objects were then analyzed with a global optimization tool developed by our group which estimates the membership likelihood of the observed stars and fits an isochrone from which a distance, age, reddening, total to selective extinction ratio RV (included in this work as a new free parameter) and metallicity are estimated. Based on those estimates and their associated errors we analyzed the status of each object as real clusters or not, finding that two are likely to be asterisms. We also identify important discrepancies between our results and previous ones obtained in the literature which were determined using 2MASS photometry.
Monteiro, Hektor; Hickel, Gabriel R; Caetano, Thiago C
2016-01-01
In the second paper of the series we continue the investigation of open cluster fundamental parameters using a robust global optimization method to fit model isochrones to photometric data. We present optical UBVRI CCD photometry (Johnsons-Cousins system) observations for 24 neglected open clusters, of which 14 have high quality data in the visible obtained for the first time, as a part of our ongoing survey being carried out in the 0.6m telescope of the Pico dos Dias Observatory in Brazil. All objects were then analyzed with a global optimization tool developed by our group which estimates the membership likelihood of the observed stars and fits an isochrone from which a distance, age, reddening, total to selective extinction ratio $R_{V}$ (included in this work as a new free parameter) and metallicity are estimated. Based on those estimates and their associated errors we analyzed the status of each object as real clusters or not, finding that two are likely to be asterisms. We also identify important discre...
Harb, Moussab
2016-03-08
The author retracts this article due to similarities with a previously published article by Le Bahers, T.; Rerat, M.; Sautet, ́ P. Semiconductors Used in Photovoltaic and Photocatalytic Devices: Assessing Fundamental Properties from DFT. J. Phys. Chem. C 2014, 118 (12), 5997−6008 (DOI: 10.1021/jp409724c).
Fundamental stellar properties from asteroseismology
DEFF Research Database (Denmark)
Silva Aguirre, V.; Casagrande, L.; Miglio, A.
2013-01-01
Accurate characterization of stellar populations is of prime importance to correctly understand the formation and evolution process of our Galaxy. The field of asteroseismology has been particularly successful in such an endeavor providing fundamental parameters for large samples of stars in diff...
Dieterich, Sergio; Henry, Todd J.; Benedict, George Fritz; Jao, Wei-Chun; White, Russel; RECONS Team
2017-01-01
Mass is the most fundamental stellar parameter, and yet model independent dynamical masses can only be obtained for a small subset of closely separated binaries. The high angular resolution needed to characterize individual components of those systems means that little is known about the details of their atmospheric properties. We discuss the results of HST/STIS observations yielding spatially resolved optical spectra for six closely separated M dwarf systems, all of which have HST/FGS precision dynamical masses for the individual components ranging from 0.4 to 0.076 MSol. We assume coevality and equal metallicity for the components of each system and use those constraints to perform stringent tests of the leading atmospheric and evolutionary model families throughout the M dwarf mass range. We find the latest models to be in good agreement with observations. We discuss specific spectral diagnostic features such as the well-known gravity sensitive Na and K lines and address ways to break the temperature-metallicity-gravity degeneracy that often hinders the interpretation of these features. We single out a comparison between the systems GJ 469 AB and G 250-29 AB, which have nearly identical mass configurations but different metallicities, thus causing marked differences in atmospheric properties and overall luminosities.This work is funded by NASA grant HST-GO-12938. and By the NSF Astronomy and Astrophysics Postdoctoral Fellowship program through NSF grant AST-1400680.
Cruzalèbes, P; Rabbia, Y; Sacuto, S; Chiavassa, A; Pasquato, E; Plez, B; Eriksson, K; Spang, A; Chesneau, O
2013-01-01
Thanks to their large angular dimension and brightness, red giants and supergiants are privileged targets for optical long-baseline interferometers. Sixteen red giants and supergiants have been observed with the VLTI/AMBER facility over a two-years period, at medium spectral resolution (R=1500) in the K band. The limb-darkened angular diameters are derived from fits of stellar atmospheric models on the visibility and the triple product data. The angular diameters do not show any significant temporal variation, except for one target: TX Psc, which shows a variation of 4% using visibility data. For the eight targets previously measured by Long-Baseline Interferometry (LBI) in the same spectral range, the difference between our diameters and the literature values is less than 5%, except for TX Psc, which shows a difference of 11%. For the 8 other targets, the present angular diameters are the first measured from LBI. Angular diameters are then used to determine several fundamental stellar parameters, and to loca...
Yu, Xiaolin; Zhang, Shaoqing; Lin, Xiaopei; Li, Mingkui
2017-03-01
The uncertainties in values of coupled model parameters are an important source of model bias that causes model climate drift. The values can be calibrated by a parameter estimation procedure that projects observational information onto model parameters. The signal-to-noise ratio of error covariance between the model state and the parameter being estimated directly determines whether the parameter estimation succeeds or not. With a conceptual climate model that couples the stochastic atmosphere and slow-varying ocean, this study examines the sensitivity of state-parameter covariance on the accuracy of estimated model states in different model components of a coupled system. Due to the interaction of multiple timescales, the fast-varying atmosphere with a chaotic nature is the major source of the inaccuracy of estimated state-parameter covariance. Thus, enhancing the estimation accuracy of atmospheric states is very important for the success of coupled model parameter estimation, especially for the parameters in the air-sea interaction processes. The impact of chaotic-to-periodic ratio in state variability on parameter estimation is also discussed. This simple model study provides a guideline when real observations are used to optimize model parameters in a coupled general circulation model for improving climate analysis and predictions.
Lubbers, Daniel D.; Willems, Tineke P.; van der Vleuten, Pieter A.; Overbosch, Jelle; Goette, Marco J. W.; van Veldhuisen, Dirk J.; Oudkerk, Matthijs
2008-01-01
The purpose of this study was to assess whether accurate global left-ventricular (LV) functional parameters can be obtained by analyzing every second short-axis magnetic resonance imaging cine series instead of consecutive slices, in order to reduce post-processing time. Forty patients, were scanned
Institute of Scientific and Technical Information of China (English)
LIU Yongqiang; HE Qing; ZHANG Hongsheng; Ali MAMTIMIN
2012-01-01
Improving and validating land surface models based on integrated observations in deserts is one of the challenges in land modeling.Particularly,key parameters and parameterization schemes in desert regions need to be evaluated in-situ to improve the models. In this study,we calibrated the land-surface key parameters and evaluated several formulations or schemes for thermal roughness length (z0h) in the common land model (CoLM).Our parameter calibration and scheme evaluation were based on the observed data during a torrid summer (29 July to 11 September 2009) over the Taklimakan Desert hinterland.First,the importance of the key parameters in the experiment was evaluated based on their physics principles and the significance of these key parameters were further validated using sensitivity test.Second,difference schemes (or physics-based formulas) of z0h were adopted to simulate the variations of energy-related variables (e.g.,sensible heat flux and surface skin temperature) and the simulated variations were then compared with the observed data.Third,the z0h scheme that performed best (i.e.,Y07) was then selected to replace the defaulted one (i.e.,Z98); the revised scheme and the superiority of Y07 over Z98 was further demonstrated by comparing the simulated results with the observed data.Admittedly,the revised model did a relatively poor job of simulating the diurnal variations of surface soil heat flux,and nighttime soil temperature was also underestimated,calling for further improvement of the model for desert regions.
Chevelkov, Veniamin; Fink, Uwe; Reif, Bernd
2009-10-01
A reliable site-specific estimate of the individual N-H bond lengths in the protein backbone is the fundamental basis of any relaxation experiment in solution and in the solid-state NMR. The N-H bond length can in principle be influenced by hydrogen bonding, which would result in an increased N-H distance. At the same time, dynamics in the backbone induces a reduction of the experimental dipolar coupling due to motional averaging. We present a 3D dipolar recoupling experiment in which the (1)H,(15)N dipolar coupling is reintroduced in the indirect dimension using phase-inverted CP to eliminate effects from rf inhomogeneity. We find no variation of the N-H dipolar coupling as a function of hydrogen bonding. Instead, variations in the (1)H,(15)N dipolar coupling seem to be due to dynamics of the protein backbone. This is supported by the observed correlation between the H(N)-N dipolar coupling and the amide proton chemical shift. The experiment is demonstrated for a perdeuterated sample of the alpha-spectrin SH3 domain. Perdeuteration is a prerequisite to achieve high accuracy. The average error in the analysis of the H-N dipolar couplings is on the order of +/-370 Hz (+/-0.012 A) and can be as small as 150 Hz, corresponding to a variation of the bond length of +/-0.005 A.
Wang, Bi-Yao; Li, Ze-Rong; Tan, Ning-Xin; Yao, Qian; Li, Xiang-Yuan
2013-04-25
We present a further interpretation of reaction class transition state theory (RC-TST) proposed by Truong et al. for the accurate calculation of rate coefficients for reactions in a class. It is found that the RC-TST can be interpreted through the isodesmic reaction method, which is usually used to calculate reaction enthalpy or enthalpy of formation for a species, and the theory can also be used for the calculation of the reaction barriers and reaction enthalpies for reactions in a class. A correction scheme based on this theory is proposed for the calculation of the reaction barriers and reaction enthalpies for reactions in a class. To validate the scheme, 16 combinations of various ab initio levels with various basis sets are used as the approximate methods and CCSD(T)/CBS method is used as the benchmarking method in this study to calculate the reaction energies and energy barriers for a representative set of five reactions from the reaction class: R(c)CH(R(b))CR(a)CH2 + OH(•) → R(c)C(•)(R(b))CR(a)CH2 + H2O (R(a), R(b), and R(c) in the reaction formula represent the alkyl or hydrogen). Then the results of the approximate methods are corrected by the theory. The maximum values of the average deviations of the energy barrier and the reaction enthalpy are 99.97 kJ/mol and 70.35 kJ/mol, respectively, before correction and are reduced to 4.02 kJ/mol and 8.19 kJ/mol, respectively, after correction, indicating that after correction the results are not sensitive to the level of the ab initio method and the size of the basis set, as they are in the case before correction. Therefore, reaction energies and energy barriers for reactions in a class can be calculated accurately at a relatively low level of ab initio method using our scheme. It is also shown that the rate coefficients for the five representative reactions calculated at the BHandHLYP/6-31G(d,p) level of theory via our scheme are very close to the values calculated at CCSD(T)/CBS level. Finally, reaction
Directory of Open Access Journals (Sweden)
Francisco-Javier Mesas-Carrascosa
2015-09-01
Full Text Available This article describes the technical specifications and configuration of a multirotor unmanned aerial vehicle (UAV to acquire remote images using a six-band multispectral sensor. Several flight missions were programmed as follows: three flight altitudes (60, 80 and 100 m, two flight modes (stop and cruising modes and two ground control point (GCP settings were considered to analyze the influence of these parameters on the spatial resolution and spectral discrimination of multispectral orthomosaicked images obtained using Pix4Dmapper. Moreover, it is also necessary to consider the area to be covered or the flight duration according to any flight mission programmed. The effect of the combination of all these parameters on the spatial resolution and spectral discrimination of the orthomosaicks is presented. Spectral discrimination has been evaluated for a specific agronomical purpose: to use the UAV remote images for the detection of bare soil and vegetation (crop and weeds for in-season site-specific weed management. These results show that a balance between spatial resolution and spectral discrimination is needed to optimize the mission planning and image processing to achieve every agronomic objective. In this way, users do not have to sacrifice flying at low altitudes to cover the whole area of interest completely.
Accurate extraction of WSe2 FETs parameters by using pulsed I-V method at various temperatures
Lee, Sung Tae; Cho, In Tak; Kang, Won Mook; Park, Byung Gook; Lee, Jong-Ho
2016-11-01
This work investigates the intrinsic characteristics of multilayer WSe2 field effect transistors (FETs) by analysing Pulsed I- V (PIV) and DC characteristics measured at various temperatures. In DC measurement, unwanted charge trapping due to the gate bias stress results in I- V curves different from the intrinsic characteristic. However, PIV reduces the effect of gate bias stress so that intrinsic characteristic of WSe2 FETs is obtained. The parameters such as hysteresis, field effect mobility (μeff), subthreshold slope ( SS), and threshold voltage ( V th) measured by PIV are significantly different from those obtained by DC measurement. In PIV results, the hysteresis is considerably reduced compared with DC measurement, because the charge trapping effect is significantly reduced. With increasing temperature, the field effect mobility (μeff) and subthreshold swing ( SS) are deteriorated, and threshold voltage ( V th) decreases.
Fundamental ecology is fundamental.
Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E
2015-01-01
The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences.
Energy Technology Data Exchange (ETDEWEB)
Sun, Ying [University of Texas at Austin; Gu, Lianhong [ORNL
2013-01-01
Worldwide measurements of nearly 130 C3 species covering all major plant functional types are analyzed in conjunction with model simulations to determine the effects of mesophyll conductance (gm) on photosynthetic parameters and their relationships estimated from A/Ci curves. We find that an assumption of infinite gm results in up to 75% underestimation for maximum carboxylation rate Vcmax, 60% for maximum electron transport rate Jmax, and 40% for triose phosphate utilization rate Tu. Vcmax is most sensitive, Jmax is less sensitive, and Tu has the least sensitivity to the variation of gm. Due to this asymmetrical effect of gm, the ratios of Jmax to Vcmax, Tu to Vcmax, and Tu to Jmax are all overestimated. An infinite gm assumption also limits the freedom of variation of estimated parameters and artificially constrains parameter relationships to stronger shapes. These findings suggest the importance of quantifying gm for understanding in-situ photosynthetic machinery functioning. We show that a nonzero resistance to CO2 movement in chloroplasts has small effects on estimated parameters. A nonlinear function with gm as input is developed to convert the parameters estimated under an assumption of infinite gm to proper values. This function will facilitate gm representation in global carbon cycle models.
Baker, Christopher M; Lopes, Pedro E M; Zhu, Xiao; Roux, Benoît; Mackerell, Alexander D
2010-03-01
Lennard-Jones (LJ) parameters for a variety of model compounds have previously been optimized within the CHARMM Drude polarizable force field to reproduce accurately pure liquid phase thermodynamic properties as well as additional target data. While the polarizable force field resulting from this optimization procedure has been shown to satisfactorily reproduce a wide range of experimental reference data across numerous series of small molecules, a slight but systematic overestimate of the hydration free energies has also been noted. Here, the reproduction of experimental hydration free energies is greatly improved by the introduction of pair-specific LJ parameters between solute heavy atoms and water oxygen atoms that override the standard LJ parameters obtained from combining rules. The changes are small and a systematic protocol is developed for the optimization of pair-specific LJ parameters and applied to the development of pair-specific LJ parameters for alkanes, alcohols and ethers. The resulting parameters not only yield hydration free energies in good agreement with experimental values, but also provide a framework upon which other pair-specific LJ parameters can be added as new compounds are parametrized within the CHARMM Drude polarizable force field. Detailed analysis of the contributions to the hydration free energies reveals that the dispersion interaction is the main source of the systematic errors in the hydration free energies. This information suggests that the systematic error may result from problems with the LJ combining rules and is combined with analysis of the pair-specific LJ parameters obtained in this work to identify a preliminary improved combining rule.
Kharchenko, N V; Schilbach, E; Röser, S; Scholz, R -D
2012-01-01
Aims: On the basis of the PPMXL star catalogue we performed a survey of star clusters in the second quadrant of the Milky Way. Methods: From the PPMXL catalogue of positions and proper motions we took the subset of stars with near-infrared photometry from 2MASS and added the remaining 2MASS stars without proper motions (called 2MAst, i.e. 2MASS with astrometry). We developed a data-processing pipeline including interactive human control of a standardised set of multi-dimensional diagrams to determine kinematic and photometric membership probabilities for stars in a cluster region. The pipeline simultaneously produced the astrophysical parameters of a cluster. From literature we compiled a target list of presently known open and globular clusters, cluster candidates, associations, and moving groups. From established member stars we derived spatial parameters (coordinates of centres and radii of the main morphological parts of clusters) and cluster kinematics (average proper motions and sometimes radial velocit...
Predoi-Cross, A.; Esteki, K.; Rozario, H.; Naseri, H.; Latif, S.; Thibault, F.; Malathy Devi, V.; Smith, M. A. H.; Mantz, A. W.
2016-11-01
We report revisited experimentally retrieved and theoretically calculated He-broadened Lorentz half-width coefficients and He- pressure-shift coefficients of 45 carbon monoxide transitions in the 1←0 band. The spectra analyzed in this study were recorded over a range of temperatures between 79 and 296 K. The He-broadened line parameters and their temperature dependences were retrieved using a multispectrum nonlinear least squares analysis program. The line shape models used in this study include Voigt, speed dependent Voigt, Rautian (to take into account confinement narrowing) and Rautian with speed dependence, all with an asymmetric component added to account for weak line mixing effects. We were unable to retrieve the temperature dependence of line mixing coefficients. A classical method was used to determine the He-narrowing parameters while quantum dynamical calculations were performed to determine He-broadening and He-pressure shifts coefficients at different temperatures. The line mixing coefficients were also derived from the exponential power gap law and the energy corrected sudden approximation. The current measurements and theoretical results are compared with other published results, where appropriate.
Fundamentally updating fundamentals.
Armstrong, Gail; Barton, Amy
2013-01-01
Recent educational research indicates that the six competencies of the Quality and Safety Education for Nurses initiative are best introduced in early prelicensure clinical courses. Content specific to quality and safety has traditionally been covered in senior level courses. This article illustrates an effective approach to using quality and safety as an organizing framework for any prelicensure fundamentals of nursing course. Providing prelicensure students a strong foundation in quality and safety in an introductory clinical course facilitates early adoption of quality and safety competencies as core practice values.
Takeda, Y; Sato, B; Liu, Y -J; Chen, Y -Q; Zhao, G
2016-01-01
Spectroscopic parameters (effective temperature, metallicity, etc) were determined for a large sample of ~100 red giants in the Kepler field, for which mass, radius, and evolutionary status had already been asteroseismologically established. These two kinds of spectroscopic and seismic information suffice to define the position on the "luminosity versus effective temperature" diagram and to assign an appropriate theoretical evolutionary track to each star. Making use of this advantage, we examined whether the stellar location on this diagram really matches the assigned track, which would make an interesting consistency check between theory and observation. It turned out that satisfactory agreement was confirmed in most cases (~90%, though appreciable discrepancies were seen for some stars such as higher-mass red-clump giants), suggesting that recent stellar evolution calculations are practically reliable. Since the relevant stellar age could also be obtained by this comparison, we derived the age-metallicity ...
Ogawa, Emiyu; Ito, Arisa; Arai, Tsunenori
2012-03-01
We studied necrotic cell death effect on myocardial cells with photosensitizer existed outside the cells varying photosensitization reaction parameters widely in vitro. We have developed non-thermal ablator with the application of photosensitization reaction for atrial fibrillation. Since laser irradiation is applied shortly after photosensitizer injection, the photosensitization reaction is induced outside the cells. The interaction for the myocardial cells by the photosensitization reaction is not well understood yet on various photosensitization reaction parameters. Rat myocardial cells were cultured in 96 well plates for 7 days. The photosensitization reaction was applied with talaporfin sodium (NPe6) and the semiconductor laser of 663nm wavelength. The average drug light interval was set 8 mins. The photosensitizer concentration and radiant exposure were varied from 5 to 40 μg/ml and 1.2 to 60 J/cm2, respectively. The well bottom was irradiated by the red laser with irradiance of 293 mW/cm2. The photosensitizer fluorescence was monitored during the photosensitization reaction. Alive cell rate was measured by WST assay after 2 hours from the irradiation. In the case of the photosensitizer concentration of 10 μg/ml, the myocardial cells were almost alive even thought 60 J/cm2 in the radiant exposure was applied. In the 15 μg/ml case, the alive cell rate was almost linear relation to the photosensitizer concentration and radiant exposure. We obtained that the threshold for myocardial cell necrosis on the photosensitizer concentration was around 15 μg/ml with 20 J/cm2 in the radiant exposure. This threshold on the photosensitizer concentration was similar to the reported threshold for cancer therapy.
Atanasov, Atanas Todorov
2016-12-01
Here is developed the hypothesis that the cell parameters of unicellular organisms (Prokaryotes and Eukaryotes) are determined by the gravitational constant (G, N.m2 /kg2), Planck constant (h, J.s) and growth rate of cells. By scaling analyses it was shown that the growth rate vgr(m/s) of unicellular bacteria and protozoa is relatively constant parameter, ranging in a narrow window of 10-12 - 10-10 m/s, in comparison to the diapason of cell mass, ranging 10 orders of magnitudes from 10-17 kg in bacteria to 10-7 kg in amoebas. By dimensional analyses it was shown that the combination between the growth rate of cells, gravitational constant and Planck constant gives equations with dimension of mass M(vgr)=(h.vgr/G)½ in kg, length L(v gr)=(hṡG/vgr3)1/2 in meter, time T(vgr)=(hṡG/vgr5)1/2 in seconds, and density ρ ((vgr)=vgr.3.5/hG2 in kg/m3 . For growth rate vgr in diapason of 1×10-11 m/s - 1×10-9.5 m/s the calculated numerical values for mass (3×10-18 -1×10-16 kg), length (5×10-8 -1×10-5 m), time (1×102 -1×106 s) and density (1×10-1 - 1×104 kg/m3) overlaps with diapason of experimentally measured values for cell mass (3×10-18 -1×10-15 kg), volume to surface ratio (1×10-7 -1×10-4 m), doubling time (1×103 -1×107 s), and density (1050 - 1300 kg/m3) in bacteria and protozoa. These equations show that appearance of the first living cells could be mutually connected to the physical constants.
Jerzykiewicz, M; Niemczura, E; Molenda-Żakowicz, J; Dymitrov, W; Fagas, M; Guenther, D B; Hartmann, M; Hrudková, M; Kamiński, K; Moffat, A F J; Kuschnig, R; Leto, G; Matthews, J M; Rowe, J F; Ruciński, S M; Sasselov, D; Weiss, W W
2013-01-01
MOST time-series photometry of mu Eri, an SB1 eclipsing binary with a rapidly-rotating SPB primary, is reported and analyzed. The analysis yields a number of sinusoidal terms, mainly due to the intrinsic variation of the primary, and the eclipse light-curve. New radial-velocity observations are presented and used to compute parameters of a spectroscopic orbit. Frequency analysis of the radial-velocity residuals from the spectroscopic orbital solution fails to uncover periodic variations with amplitudes greater than 2 km/s. A Rossiter-McLaughlin anomaly is detected from observations covering ingress. From archival photometric indices and the revised Hipparcos parallax we derive the primary's effective temperature, surface gravity, bolometric correction, and the luminosity. An analysis of a high signal-to-noise spectrogram yields the effective temperature and surface gravity in good agreement with the photometric values. From the same spectrogram, we determine the abundance of He, C, N, O, Ne, Mg, Al, Si, P, S,...
Markov, Yu. G.; Mikhailov, M. V.; Pochukaev, V. N.
2012-07-01
An analysis of perturbing factors influencing the motion of a navigation satellite (NS) is carried out, and the degree of influence of each factor on the GLONASS orbit is estimated. It is found that fundamental components of the Earth's rotation parameters (ERP) are one substantial factor commensurable with maximum perturbations. Algorithms for the calculation of orbital perturbations caused by these parameters are given; these algorithms can be implemented in a consumer's equipment. The daily prediction of NS coordinates is performed on the basis of real GLONASS satellite ephemerides transmitted to a consumer, using the developed prediction algorithms taking the ERP into account. The obtained accuracy of the daily prediction of GLONASS ephemerides exceeds by tens of times the accuracy of the daily prediction performed using algorithms recommended in interface control documents.
De la Sen, M
2008-01-01
This paper deals with a unifying approach to the problems of computing the admissible sets of parametrical multi perturbations in appropriate bounded sets such that some fundamental properties of parameter-varying linear dynamic systems are maintained provided that the so-called (i.e. perturbation-free) nominal system possesses such properties. The sets of parametrical multi perturbations include any combinations of parametrical multi perturbations in the matrix of dynamics as well as in the control, output and input-output interconnection matrices which belong to some prescribed bounded domain in the complex space. The various properties which are investigated are controllability, observability, output controllability and existence of minimal state-space realizations together with the associate existence or not of associate decoupling, transmission and invariant zeros. All the matrices of parameters including the nominal and the disturbed ones which parameterize the dynamic system may be real or complex. The...
Kervella, P.; Mérand, A.; Ledoux, C.; Demory, B.-O.; Le Bouquin, J.-B.
2016-10-01
The nearby red dwarf binary GJ65 AB (UV+BL Ceti, M5.5Ve+M6Ve) is a cornerstone system to probe the physics of very low-mass stars. The radii of the two stars are currently known only from indirect photometric estimates, however, and this prevents us from using GJ65 AB as calibrators for the mass-radius (M-R) relation. We present new interferometric measurements of the angular diameters of the two components of GJ65 with the VLTI/PIONIER instrument in the near-infrared H band: θUD(A) = 0.558 ± 0.008 ± 0.020 mas and θUD(B) = 0.539 ± 0.009 ± 0.020 mas. They translate into limb-darkened angular diameters of θLD(A) = 0.573 ± 0.021 mas and θLD(B) = 0.554 ± 0.022 mas. Based on the known parallax, the linear radii are R(A) = 0.165 ± 0.006 R⊙ and R(B) = 0.159 ± 0.006 R⊙ (σ(R) /R = 4%). We searched for the signature of flares and faint companions in the interferometric visibilities and closure phases, but we did not identify any significant signal. We also observed GJ65 with the VLT/NACO adaptive optics and refined the orbital parameters and infrared magnitudes of the system. We derived masses for the two components of m(A) = 0.1225 ± 0.0043 M⊙ and m(B) = 0.1195 ± 0.0043 M⊙ (σ(m) /m = 4%). To derive the radial and rotational velocities of the two stars as well as their relative metallicity with respect to Proxima, we also present new individual UVES high-resolution spectra of the two components. Placing GJ65 A and B in the mass-radius diagram shows that their radii exceed expectations from recent models by 14 ± 4% and 12 ± 4%, respectively. Following previous theories, we propose that this discrepancy is caused by the inhibition of convective energy transport by a strong internal magnetic field generated by dynamo effect in these two fast-rotating stars. A comparison with the almost identical twin Proxima, which is rotating slowly, strengthens this hypothesis because the radius of Proxima does not appear to be inflated compared to models. Based on
Energy Technology Data Exchange (ETDEWEB)
Cazzoli, Gabriele; Lattanzi, Valerio; Puzzarini, Cristina [Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Alonso, José Luis [Grupo de Espectroscopía Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Universidad de Valladolid, E-47005 Valladolid (Spain); Gauss, Jürgen, E-mail: cristina.puzzarini@unibo.it [Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz (Germany)
2015-06-10
The rotational spectrum of the mono-deuterated isotopologue of water, HD{sup 16}O, has been investigated in the millimeter- and submillimeter-wave frequency regions, up to 1.6 THz. The Lamb-dip technique has been exploited to obtain sub-Doppler resolution and to resolve the hyperfine (hf) structure due to the deuterium and hydrogen nuclei, thus enabling the accurate determination of the corresponding hf parameters. Their experimental determination has been supported by high-level quantum-chemical calculations. The Lamb-dip measurements have been supplemented by Doppler-limited measurements (weak high-J and high-frequency transitions) in order to extend the predictive capability of the available spectroscopic constants. The possibility of resolving hf splittings in astronomical spectra has been discussed.
Higton, Sam; Walsh, Rory
2015-04-01
X-Ray Fluorescence (XRF) is an important technique for measuring the concentrations of geochemical elements and inorganic contaminants adsorbed to sediments as an input to sediment tracing methods used to evaluate sediment transport dynamics in river catchments. In addition to traditional laboratory-based XRF instruments, the advent of increasingly advanced portable handheld XRF devices now mean that samples of fluvial sediment can be analysed in the field or in the laboratory following appropriate sample preparation procedures. There are limitations and sources of error associated with XRF sample preparation and analysis, however. It is therefore important to understand how fundamental parameters involved in sample preparation and analysis, such as sample compression and measurement exposure duration, affect observed variability in measurement results. Such considerations become important if the resulting measurement variability is high relative to the natural variability in element concentrations at a sample site. This paper deployed a simple experimental design to assess the impacts of varying a number of sample preparation and XRF analysis parameters on recorded measurements of elemental concentrations of the fine fraction (weight and sample quantity was sufficient to satisfy the assumption of 'infinite thickness' of sample. Standard plastic sample cups were used for both the Rigaku laboratory machine and the Niton portable XRF machine. A computer-controlled desktop laboratory stand was used in conjunction with the Niton handheld XRF analyser to ensure consistent repeated measurements. Parameters investigated related to sample preparation included consistent mechanical compression of samples within the sample cup and film thickness. Parameters investigated related to XRF analysis included the XRF machine selected and measurement exposure duration. As XRF is a non-destructive technique, wherever possible the same sample material was used to test different
Manara, C F; Da Rio, N; De Marchi, G; Natta, A; Ricci, L; Robberto, M; Testi, L
2013-01-01
Current planet formation models are largely based on the observational constraint that protoplanetary disks have lifetime 3Myr. Recent studies, however, report the existence of PMS stars with signatures of accretion (strictly connected with the presence of circumstellar disks)and photometrically determined ages of 30 Myr, or more. Here we present a spectroscopic study of two major age outliers in the ONC. We use broad band, intermediate resolution VLT/X-Shooter spectra combined with an accurate method to determine the stellar parameters and the related age of the targets to confirm their peculiar age estimates and the presence of ongoing accretion.The analysis is based on a multi-component fitting technique, which derives simultaneously SpT, extinction, and accretion properties of the objects. With this method we confirm and quantify the ongoing accretion. From the photospheric parameters of the stars we derive their position on the HRD, and the age given by evolutionary models. Together with other age indica...
Park, Youngsu; Kim, Jong-Wook; Kim, Johwan; Kim, Sang Woo
Erratum: New Encoding Method of Parameter for Dynamic Encoding Algorithm for Searches (DEAS) [IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E94.A (2011) , No. 9 pp.1804-1816
Whitlock, C. H., III
1977-01-01
Constituents with linear radiance gradients with concentration may be quantified from signals which contain nonlinear atmospheric and surface reflection effects for both homogeneous and non-homogeneous water bodies provided accurate data can be obtained and nonlinearities are constant with wavelength. Statistical parameters must be used which give an indication of bias as well as total squared error to insure that an equation with an optimum combination of bands is selected. It is concluded that the effect of error in upwelled radiance measurements is to reduce the accuracy of the least square fitting process and to increase the number of points required to obtain a satisfactory fit. The problem of obtaining a multiple regression equation that is extremely sensitive to error is discussed.
Luz, Anthony L; Rooney, John P; Kubik, Laura L; Gonzalez, Claudia P; Song, Dong Hoon; Meyer, Joel N
2015-01-01
Mitochondrial dysfunction has been linked to myriad human diseases and toxicant exposures, highlighting the need for assays capable of rapidly assessing mitochondrial health in vivo. Here, using the Seahorse XFe24 Analyzer and the pharmacological inhibitors dicyclohexylcarbodiimide and oligomycin (ATP-synthase inhibitors), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (mitochondrial uncoupler) and sodium azide (cytochrome c oxidase inhibitor), we measured the fundamental parameters of mitochondrial respiratory chain function: basal oxygen consumption, ATP-linked respiration, maximal respiratory capacity, spare respiratory capacity and proton leak in the model organism Caenhorhabditis elegans. Since mutations in mitochondrial homeostasis genes cause mitochondrial dysfunction and have been linked to human disease, we measured mitochondrial respiratory function in mitochondrial fission (drp-1)-, fusion (fzo-1)-, mitophagy (pdr-1, pink-1)-, and electron transport chain complex III (isp-1)-deficient C. elegans. All showed altered function, but the nature of the alterations varied between the tested strains. We report increased basal oxygen consumption in drp-1; reduced maximal respiration in drp-1, fzo-1, and isp-1; reduced spare respiratory capacity in drp-1 and fzo-1; reduced proton leak in fzo-1 and isp-1; and increased proton leak in pink-1 nematodes. As mitochondrial morphology can play a role in mitochondrial energetics, we also quantified the mitochondrial aspect ratio for each mutant strain using a novel method, and for the first time report increased aspect ratios in pdr-1- and pink-1-deficient nematodes.
Mahy, L; De Becker, M; Eenens, P; Flores, C A
2015-01-01
Aims. Having established the binary status of nineteen O-type stars located in four Cygnus OB associations, we now determine their fundamental parameters to constrain their properties and their evolutionary status. We also investigate their surface nitrogen abundances, which we compare with other results from the literature obtained for galactic O-type stars. Methods. Using optical spectra collected for each object in our sample and some UV data from the archives, we apply the CMFGEN atmosphere code to determine their main properties. For the binary systems, we have disentangled the components to obtain their individual spectra and investigate them as if they were single stars. Results. We find that the distances of several presumably single O-type stars seem poorly constrained because their luminosities are not in agreement with the "standard" luminosities of stars with similar spectral types. The ages of these O-type stars are all less than 7 Myrs. Therefore, the ages of these stars agree with those, quoted...
Directory of Open Access Journals (Sweden)
Yu Xie
2015-08-01
Full Text Available This paper is an attempt to elucidate the effects of the important spray characteristics on the surface morphology and light absorbance of spray-on P3HT:PCBM thin-films, used as an active layer in polymer solar cells (PSCs. Spray coating or deposition is a viable scalable technique for the large-scale, fast, and low-cost fabrication of solution-processed solar cells, and has been widely used for device fabrication, although the fundamental understanding of the underlying and controlling parameters, such as spray characteristics, droplet dynamics, and surface wettability, is still limited, making the results on device fabrication not reproducible and unreliable. In this paper, following the conventional PSC architecture, a PEDOT:PSS layer is first spin-coated on glass substrates, followed by the deposition of P3HT:PCBM using an automatic ultrasonic spray coating system, with a movable nozzle tip, to mimic an industrial manufacturing process. To gain insight, the effects of the spray carrier air pressure, the number of spray passes, the precursor flow rate, and precursor concentration are studied on the surface topography and light absorbance spectra of the spray-on films. Among the results, it is found that despite the high roughness of spray-on films, the light absorbance of the film is satisfactory. It is also found that the absorbance of spray-on films is a linear function of the number of spray passes or deposition layers, based on which an effective film thickness is defined for rough spray-on films. The effective thickness of a rough spray-on P3HT:PCBM film was found to be one-quarter of that of a flat film predicted by a simple mass balance.
Institute of Scientific and Technical Information of China (English)
曹洪林; 孔江平; 王英利
2013-01-01
为研究发音人基频参数与生理参数之间的关系,该文通过对70位男性发音人所讲汉语普通话的篇章语料进行分析,提取基频,计算每位发音人基频的均值、中位数、众数和标准差,分析其与发音人的身高、体重、全头高、头长、头宽、颈前弧长、肩宽、头围、颈围、胸围等12种生理参数之间的相关性.实验结果表明:基频的均值、众数和中位数与发音人生理参数之间没有显著相关；而基频的标准差与发音人的身高、体重、肩宽、颈围和胸围5种参数之间都存在显著负相关.由此可知,基频的标准差可以用来预测男性发音人的体形大小.%The purpose of this investigation is to determine the relationship between the fundamental frequency (F0) and the speakers' physiological parameters.Recordings of 70 males speaking a Mandarin passage are analyzed based on F0.The mean,median,mode and standard deviation (SD) of each speaker's long-term F0 are calculated.Pearson correlations are calculated to estimate the relationship between all four types of F0 and 12 kinds of physiological variables,such as height,weight,total head height,head length,head breadth,anterior neck length,shoulder breadth,head circumference,neck circumference and chest circumference.The results show no significant correlations between the mean,median,mode value of F0 and the physiological parameters.However,significant negative relationships are found between SD of F0 and the speakers' height,weight,shoulder breadth,neck circumference and chest circumference.Therefore,SD of F0 can be used to predict male body sizes.
Singh, Harjit
2011-01-01
""Radiology Fundamentals"" is a concise introduction to the dynamic field of radiology for medical students, non-radiology house staff, physician assistants, nurse practitioners, radiology assistants, and other allied health professionals. The goal of the book is to provide readers with general examples and brief discussions of basic radiographic principles and to serve as a curriculum guide, supplementing a radiology education and providing a solid foundation for further learning. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imag
Ghazy, Riyad; Hendawy, Nabil; Said, S.; Nafie, Hassan; El-Mekawey, Farouk
In this article the obtained results of refractive index, by laser interferometer method, of Carbon Dioxide, CO2, molecule were used to determine the physical parameters of this pollutant gas. Because the existence of this gas in the atmosphere under the effect of the atmospheric changes like as pressure, temperature and sun light. These atmospheric changes change the behavior of this pollutant gas according to the change of its physical parameters which tends to more destructive effects on the biological cells. Optical permittivity ɛ, dielectric susceptibility ke, specific refractivity Asp, and molar refractivity Π were determined. The effect of temperature T[K], within the available technical range 308K-358K, on these physical parameters was studied which was known as thermal behavior. The rate of change of these parameters with respect to temperature at constant gas pressure p and incident laser wavelength λ such as (dɛ/dT)p,λ; (dke/dT)p,λ; (dAsp/dT)p,λ; and (dΠ/dT)p,λ were studied showing negative slope values which mean an inverse dependence of ɛ, ke, Asp, and Π respectively. Also, the rate of change of those parameters with respect pressure range 80×103-120×103Pa at constant temperature and laser wavelength, (dɛ/dp)T,λ; (dke/dp)T,λ; (dAsp/dp)T,λ; and (dΠ/dp)T,λ were investigated showing direct proportionality between these parameters and pressure. In addition, the dispersion of these physical parameters, rate of their change with respect to λ, four different selected wavelength, at constant T and p of CO2-gas to be (dɛ/dλ)T,p; (dke/dλ)T,p; (dAsp/dλ)T,p; and (dΠ/dλ)T,p were studied representing inverse dependence of these parameters on λ. The behavior investigations of these physical parameters consider as an index for environmental air pollution investigations.
Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan
2007-01-01
Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.
Testing Our Fundamental Assumptions
Kohler, Susanna
2016-06-01
fundamental assumptions.A recent focus set in the Astrophysical Journal Letters, titled Focus on Exploring Fundamental Physics with Extragalactic Transients, consists of multiple published studies doing just that.Testing General RelativitySeveral of the articles focus on the 4th point above. By assuming that the delay in photon arrival times is only due to the gravitational potential of the Milky Way, these studies set constraints on the deviation of our galaxys gravitational potential from what GR would predict. The study by He Gao et al. uses the different photon arrival times from gamma-ray bursts to set constraints at eVGeV energies, and the study by Jun-Jie Wei et al. complements this by setting constraints at keV-TeV energies using photons from high-energy blazar emission.Photons or neutrinos from different extragalactic transients each set different upper limits on delta gamma, the post-Newtonian parameter, vs. particle energy or frequency. This is a test of Einsteins equivalence principle: if the principle is correct, delta gamma would be exactly zero, meaning that photons of different energies move at the same velocity through a vacuum. [Tingay Kaplan 2016]S.J. Tingay D.L. Kaplan make the case that measuring the time delay of photons from fast radio bursts (FRBs; transient radio pulses that last only a few milliseconds) will provide even tighter constraints if we are able to accurately determine distances to these FRBs.And Adi Musser argues that the large-scale structure of the universe plays an even greater role than the Milky Way gravitational potential, allowing for even stricter testing of Einsteins equivalence principle.The ever-narrower constraints from these studies all support GR as a correct set of rules through which to interpret our universe.Other Tests of Fundamental PhysicsIn addition to the above tests, Xue-Feng Wu et al. show that FRBs can be used to provide severe constraints on the rest mass of the photon, and S. Croft et al. even touches on what we
Redmond, W H
2001-01-01
This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined.
Energy Technology Data Exchange (ETDEWEB)
Tamandl, Dietmar; Fueger, Barbara; Kinsperger, Patrick; Haug, Alexander; Ba-Ssalamah, Ahmed [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Gore, Richard M. [University of Chicago Pritzker School of Medicine, Department of Radiology, Chicago, IL (United States); Hejna, Michael [Medical University of Vienna, Department of Internal Medicine, Division of Medical Oncology, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Paireder, Matthias; Schoppmann, Sebastian F. [Medical University of Vienna, Department of Surgery, Upper-GI-Service, Comprehensive Cancer Center GET-Unit, Vienna (Austria)
2016-02-15
To assess the prognostic value of volumetric parameters measured with CT and PET/CT in patients with neoadjuvant chemotherapy (NACT) and resection for oesophageal cancer (EC). Patients with locally advanced EC, who were treated with NACT and resection, were retrospectively analysed. Data from CT volumetry and {sup 18} F-FDG PET/CT (maximum standardized uptake [SUVmax], metabolic tumour volume [MTV], and total lesion glycolysis [TLG]) were recorded before and after NACT. The impact of volumetric parameter changes induced by NACT (MTV{sub RATIO}, TLG{sub RATIO}, etc.) on overall survival (OS) was assessed using a Cox proportional hazards model. Eighty-four patients were assessed using CT volumetry; of those, 50 also had PET/CT before and after NACT. Low post-treatment CT volume and thickness, MTV, TLG, and SUVmax were all associated with longer OS (p < 0.05), as were CTthickness{sub RATIO}, MTV{sub RATIO}, TLG{sub RATIO}, and SUVmax{sub RATIO} (p < 0.05). In the multivariate analysis, only MTV{sub RATIO} (Hazard ratio, HR 2.52 [95 % Confidence interval, CI 1.33-4.78], p = 0.005), TLG{sub RATIO} (HR 3.89 [95%CI 1.46-10.34], p = 0.006), and surgical margin status (p < 0.05), were independent predictors of OS. MTV{sub RATIO} and TLG{sub RATIO} are independent prognostic factors for survival in patients after NACT and resection for EC. (orig.)
Fogel, R; Limson, J L
2011-07-10
The method of immobilization of a protein has a great influence on the overall conformation, and hence, functioning of the protein. Thus, a greater understanding of the events undergone by the protein during immobilization is key to manipulating the immobilization method to produce a strategy that influences the advantages of immobilization while minimizing their disadvantages in biosensor design. In this, the second paper of a two-part series, we have assessed the kinetic parameters of thin-film laccase monolayers, covalently attached to SAMs differing in spacer-arm length and lateral density of spacer arms. This was achieved using chronoamperometry and an electroactive product (p-benzoquinone), which was modeled in a non-linear regressional fashion to extract the relevant parameters. Finally, comparisons between the kinetic parameters presented in this paper and the rheological parameters of laccase monolayers immobilized in the same manner (Part I of this two paper series) were performed. Improvements in the maximal enzyme-catalysed current, i(max), the apparent Michaelis-Menten constant, K(m) and the apparent biosensor sensitivity were noted for most of the surfaces with increasing linker length. Decreasing the lateral density of the spacer-arms brought about a general improvement in these parameters, which is attributed to the decrease in multiple points of immobilization undergone by functional proteins. Finally, comparisons between rheological data and kinetics data showed that the degree of viscosity exhibited by protein films has a negative influence on attached protein layers, while enhanced protein hydration levels (assessed piezoelectrically from data obtained in Paper 1) has a positive effect on those surfaces comprising rigidly bound protein layers.
Institute of Scientific and Technical Information of China (English)
徐玉茹; 徐付霞
2016-01-01
证明了几何分布参数的充分统计量服从负二项分布，由此将负二项分布转化为生存贝塔分布，构造出了参数的精确置信区间，并且在不同的置信度组合中选出最佳组合，得到精确最短置信区间。讨论了大样本下几何分布的近似区间估计，通过数值模拟，直观展示区间估计的精度变化，说明了精确最短区间估计的优良性。%This paper proved that the sufficient statistic of a geometric distribution parameter is subjected to the negative binomial distribution .Therefore, constructed the exact confi-dence interval of the parameter by converting the negative binomial distribution into the sur -vival beta distribution, and select the best combination in different levels of the confidence to get the accurate shortest confidence interval of its parameter .The approximate interval esti-mate under the large sample of a geometric distribution was discussed in this paper .Through numerical simulation, the change of the accuracy of an interval estimation was intuitively demonstrated, and then the superiority of the accurate shortest confidence interval was illus -trated.
Vogt, N P; Giovanelli, R; Herter, T; Vogt, Nicole P.; Haynes, Martha P.; Giovanelli, Riccardo; Herter, Terry
2004-01-01
We have conducted a study of optical and HI properties of spiral galaxies (size, luminosity, H-alpha flux distribution, circular velocity, HI gas mass) to investigate causes (e.g., nature versus nurture) for variation within the cluster environment. We find HI deficient cluster galaxies to be offset in Fundamental Plane space, with disk scale lengths decreased by a factor of 25%. This may be a relic of early galaxy formation, caused by the disk coalescing out of a smaller, denser halo (e.g., higher concentration index) or by truncation of the hot gas envelope due to the enhanced local density of neighbors, though we cannot completely rule out the effect of the gas stripping process. The spatial extent of H-alpha flux and the B-band radius also decreases, but only in early type spirals, suggesting that gas removal is less efficient within steeper potential wells (or that stripped late type spirals are quickly rendered unrecognizable). We find no significant trend in stellar mass-to-light ratios or circular vel...
Vogt, Nicole P.; Haynes, Martha P.; Giovanelli, Riccardo; Herter, Terry
2004-06-01
We have conducted a study of optical and H I properties of spiral galaxies (size, luminosity, Hα flux distribution, circular velocity, H I gas mass) to investigate causes (e.g., nature vs. nurture) for variation within the cluster environment. We find H I-deficient cluster galaxies to be offset in fundamental plane space, with disk scale lengths decreased by a factor of 25%. This may be a relic of early galaxy formation, caused by the disk coalescing out of a smaller, denser halo (e.g., higher concentration index) or by truncation of the hot gas envelope due to the enhanced local density of neighbors, although we cannot completely rule out the effect of the gas stripping process. The spatial extent of Hα flux and the B-band radius also decreases, but only in early-type spirals, suggesting that gas removal is less efficient within steeper potential wells (or that stripped late-type spirals are quickly rendered unrecognizable). We find no significant trend in stellar mass-to-light ratios or circular velocities with H I gas content, morphological type, or clustercentric radius, for star-forming spiral galaxies throughout the clusters. These data support the findings of a companion paper that gas stripping promotes a rapid truncation of star formation across the disk and could be interpreted as weak support for dark matter domination over baryons in the inner regions of spiral galaxies.
Wang, Yong; Goh, Wang Ling; Chai, Kevin T-C; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu
2016-04-01
The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators.
The Application of Fundamental Parameters Method in EDXRF Based on SDD%FP法在SDD-EDXRF无标样分析技术中的应用研究
Institute of Scientific and Technical Information of China (English)
刘敏; 庹先国; 李哲; 石睿
2012-01-01
It created the FP mathematical analysis model in order to use EDXRF technique to analyze element contents without sample and gained the key parameters of the model such as mass - absorption coefficients and excitation factors. In experiment, two kinds of pseudobinary system containing Fe - Cu and Fe - Ti were analyzed with an energy dispersive X - ray analyzer based on a SDD and each element's content of the samples were calculated via the FP calculation procedure, the deviation of the accuracy is no more than 0.8% and the lowest relative error between calculated value and actual value is 2% . The result shows the FP method can overcome the absorption and enhancement effects between elements and apply to SDD - EDXRF analysis process well with no sample .%为实现能量色散X荧光(EDXRF)技术对元素含量的无标样分析,建立了基本参数法(FP法)数理分析模型,并计算得到了模型中质量吸收系数(μ)、激发因子(E)等关键参数.实验中,利用基于硅漂移探测器(SDD)的EDXRF测量系统(SDD-EDXRF),对Fe-Cu、Fe-Ti两种伪二元体系样品进行能谱测量,并采用自行开发的FP法计算程序,分析得到了混合样品中各元素含量,含量的计算值与实际值的最低相对误差小于2％,精密度相对标准偏差低于0.8％.结果表明,所建立的FP法分析模型,能较好克服元素间的吸收增强效应,可应用于SDD-EDXRF的无标样分析过程.
Energy Technology Data Exchange (ETDEWEB)
Rackwitz, Vanessa
2012-05-30
For a decade X-ray sources have been commercially available for the microfocus X-ray fluorescence analysis ({mu}-XRF) and offer the possibility of extending the analytics at a scanning electron microscope (SEM) with an attached energy dispersive X-ray spectrometer (EDS). By using the {mu}-XRF it is possible to determine the content of chemical elements in a microscopic sample volume in a quantitative, reference-free and non-destructive way. For the reference-free quantification with the XRF the Sherman equation is referred to. This equation deduces the intensity of the detected X-ray intensity of a fluorescence peak to the content of the element in the sample by means of fundamental parameters. The instrumental fundamental parameters of the {mu}-XRF at a SEM/EDS system are the excitation spectrum consisting of X-ray tube spectrum and the transmission of the X-ray optics, the geometry and the spectrometer efficiency. Based on a calibrated instrumentation the objectives of this work are the development of procedures for the characterization of all instrumental fundamental parameters as well as the evaluation and reduction of their measurement uncertainties: The algorithms known from the literature for the calculation of X-ray tube spectrum are evaluated with regard to their deviations in the spectral distribution. Within this work a novel semi-empirical model is improved with respect to its uncertainties and enhanced in the low energy range as well as extended for another three anodes. The emitted X-ray tube spectrum is calculated from the detected one, which is measured at an especially developed setup for the direct measurement of X-ray tube spectra. This emitted X-ray tube spectrum is compared to the one calculated on base of the model of this work. A procedure for the determination of the most important parameters of an X-ray semi-lens in parallelizing mode is developed. The temporal stability of the transmission of X-ray full lenses, which have been in regular
Institute of Scientific and Technical Information of China (English)
罗立强; 甘露; 吴晓军; 吉昂; 梁国立
2001-01-01
提出了神经网络基本参数-NNFP 算法。将 NNFP 算法应用于X射线荧光定量分析中，与理论α系数相比，NNFP 算法提高了非线性基体效应校正能力和预测准确度。%An algorithm of combining neural networks with the fundamental parameters(NNFP) was proposed and compared with the theoretical alpha coefficient based on classical matrix correction models. The results show that NNFP has more powerful ability of correcting the nonlinear matrix effects than the theoretical alpha coefficient and partial least-square regression(PLS) in X-ray fluorescence analysis.
Directory of Open Access Journals (Sweden)
Sérgio Afonso Henneman
2012-09-01
Full Text Available Este trabalho propõe um parâmetro anatômico, a incidência pélvica, como fator chave para a compreensão do alinhamento da coluna vertebral. Existe estreita relação, tanto para indivíduos normais como para indivíduos com deformidades da coluna, entre o parâmetro anatômico de incidência pélvica e a inclinação sacral, determinantes da lordose lombar. O ângulo de Cobb e a rotação vertebral apical servem de instrumento para o entendimento do aspecto tridimensional da coluna vertebral e das relações entre a pelve e a coluna. Uma equação preditiva para lordose é apresentada. A incidência pélvica parece ser o fator determinante do equilíbrio sagital da coluna. Ela determina as curvas da coluna vertebral, variando conforme outros parâmetros.En este trabajo se propone un parámetro anatómico, la incidencia de la pelvis, como el factor clave para entender la alineación de la columna vertebral. Hay estrecha relación, tanto para el normal y para las personas con deformidades de la columna entre el parámetro anatómico de la incidencia de la pelvis y la inclinación del sacro, determinantes de la lordosis lumbar. El ángulo de Cobb y la rotación vertebral apical sirven como una herramienta para entender el aspecto tridimensional de la columna vertebral y de su relación con la pelvis. Se presenta una ecuación de predicción para la lordosis. La incidencia pélvica parece ser el factor determinante del equilibrio sagital de la columna. Dicha ecuación determina las curvas de la columna y varía según otros parámetros.This paper proposes an anatomical parameter, the pelvic incidence, as the key factor for managing the spinal balance. There is a close relationship for both normal individuals and those with spinal deformities between the anatomical parameter of pelvic incidence and the sacral slope, which determine lumbar lordosis. The Cobb angle and the apical vertebral rotation serve as a tool for understanding the three
Cardone, V F; Diaferio, A; Tortora, C; Molinaro, R
2010-01-01
Modified Newtonian Dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully - Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early - type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion $\\sigma_0$ of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sersic n parameter and the stellar M/L ratio, MOND predicts a fundamental plane for ETGs : a log - linear relation among the effective radius $R_{eff}$, $\\sigma_0$ and the mean effective intensity $\\langle I_e \\rangle$. However, we predict a tilt between the observed and the MOND fundamental planes.
Fundamentals of Structural Engineering
Connor, Jerome J
2013-01-01
Fundamentals of Structural Engineering provides a balanced, seamless treatment of both classic, analytic methods and contemporary, computer-based techniques for conceptualizing and designing a structure. The book’s principle goal is to foster an intuitive understanding of structural behavior based on problem solving experience for students of civil engineering and architecture who have been exposed to the basic concepts of engineering mechanics and mechanics of materials. Making it distinct from many other undergraduate textbooks, the authors of this text recognize the notion that engineers reason about behavior using simple models and intuition they acquire through problem solving. The approach adopted in this text develops this type of intuition by presenting extensive, realistic problems and case studies together with computer simulation, which allows rapid exploration of how a structure responds to changes in geometry and physical parameters. This book also: Emphasizes problem-based understanding of...
Digital Fourier analysis fundamentals
Kido, Ken'iti
2015-01-01
This textbook is a thorough, accessible introduction to digital Fourier analysis for undergraduate students in the sciences. Beginning with the principles of sine/cosine decomposition, the reader walks through the principles of discrete Fourier analysis before reaching the cornerstone of signal processing: the Fast Fourier Transform. Saturated with clear, coherent illustrations, "Digital Fourier Analysis - Fundamentals" includes practice problems and thorough Appendices for the advanced reader. As a special feature, the book includes interactive applets (available online) that mirror the illustrations. These user-friendly applets animate concepts interactively, allowing the user to experiment with the underlying mathematics. For example, a real sine signal can be treated as a sum of clockwise and counter-clockwise rotating vectors. The applet illustration included with the book animates the rotating vectors and the resulting sine signal. By changing parameters such as amplitude and frequency, the reader ca...
Energy Technology Data Exchange (ETDEWEB)
Hareter, M.; Weiss, W. [Department of Astronomy, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); Fossati, L. [Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes MK6 7AA (United Kingdom); Suarez, J. C. [Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia S/N, 18008, Granada (Spain); Uytterhoeven, K. [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstr. 6, D-79104 Freiburg (Germany); Rainer, M.; Poretti, E., E-mail: hareter@astro.univie.ac.at [INAF-Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807, Merate (Saint Lucia) (Italy)
2011-12-20
{delta} Sct-{gamma} Dor hybrids pulsate simultaneously in p- and g-modes, which carry information on the structure of the envelope as well as to the core. Hence, they are key objects for investigating A and F type stars with asteroseismic techniques. An important requirement for seismic modeling is small errors in temperature, gravity, and chemical composition. Furthermore, we want to investigate the existence of an abundance indicator typical for hybrids, something that is well established for the roAp stars. Previous to the present investigation, the abundance pattern of only one hybrid and another hybrid candidate has been published. We obtained high-resolution spectra of HD 114839 and BD +18 4914 using the SOPHIE spectrograph of the Observatoire de Haute-Provence and the HARPS spectrograph at ESO La Silla. For each star we determined fundamental parameters and photospheric abundances of 16 chemical elements by comparing synthetic spectra with the observations. We compare our results to that of seven {delta} Sct and nine {gamma} Dor stars. For the evolved BD +18 4914 we found an abundance pattern typical for an Am star, but could not confirm this peculiarity for the less evolved star HD 114839, which is classified in the literature as uncertain Am star. Our result supports the concept of evolved Am stars being unstable. With our investigation we nearly doubled the number of spectroscopically analyzed {delta} Sct-{gamma} Dor hybrid stars, but did not yet succeed in identifying a spectroscopic signature for this group of pulsating stars. A statistically significant spectroscopic investigation of {delta} Sct- {gamma} Dor hybrid stars is still missing, but would be rewarding considering the asteroseismological potential of this group.
Exchange Rates and Fundamentals.
Engel, Charles; West, Kenneth D.
2005-01-01
We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…
Babu, V
2014-01-01
Fundamentals of Gas Dynamics, Second Edition isa comprehensively updated new edition and now includes a chapter on the gas dynamics of steam. It covers the fundamental concepts and governing equations of different flows, and includes end of chapter exercises based on the practical applications. A number of useful tables on the thermodynamic properties of steam are also included.Fundamentals of Gas Dynamics, Second Edition begins with an introduction to compressible and incompressible flows before covering the fundamentals of one dimensional flows and normal shock wav
Nucleosynthesis and the variation of fundamental couplings
2004-01-01
We determine the influence of a variation of the fundamental ``constants'' on the predicted helium abundance in Big Bang Nucleosynthesis. The analytic estimate is performed in two parts: the first step determines the dependence of the helium abundance on the nuclear physics parameters, while the second step relates those parameters to the fundamental couplings of particle physics. This procedure can incorporate in a flexible way the time variation of several couplings within a grand unified t...
Halliday, David; Resnick, Robert; Walker, Jearl
2003-01-01
No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.
Schubert, Thomas F
2015-01-01
This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to
Fundamental Aspects of Biosensors
Directory of Open Access Journals (Sweden)
K.Sowjanya
2016-06-01
Full Text Available A biosensor is an analytical device which converts a biological response into an electrical signal. The term 'biosensor' is often used to cover sensor devices used in order to determine the concentration of substances and other parameters of biological interest even where they do not utilize a biological system directly. This very broad definition is used by some scientific journals (e.g. Biosensors, Elsevier Applied Science but will not be applied to the coverage here. The emphasis of this Chapter concerns enzymes as the biologically responsive material, but it should be recognized that other biological systems may be utilized by biosensors, for example, whole cell metabolism, ligand binding and the antibody-antigen reaction. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry (e.g. 6% of the western world are diabetic and would benefit from the availability of a rapid, accurate and simple biosensor for glucose but with some pressure from other areas, such as food quality appraisal and environmental monitoring. The estimated world analytical market is about 12,000,000,000 year- 1 of which 30% is in the health care area. There is clearly a vast market expansion potential as less than 0.1% of this market is currently using biosensors. Research and development in this field is wide and multidisciplinary, spanning biochemistry, bioreactor science, physical chemistry, electrochemistry, electronics and software engineering. Most of this current endeavour concerns potentiometric and amperometric biosensors and colorimetric paper enzyme strips. However, all the main transducer types are likely to be thoroughly examined, for use in biosensors, over the next few years.
Fundamentals of electrochemical science
Oldham, Keith
1993-01-01
Key Features* Deals comprehensively with the basic science of electrochemistry* Treats electrochemistry as a discipline in its own right and not as a branch of physical or analytical chemistry* Provides a thorough and quantitative description of electrochemical fundamentals
Fundamentals of crystallography
2011-01-01
Crystallography is a basic tool for scientists in many diverse disciplines. This text offers a clear description of fundamentals and of modern applications. It supports curricula in crystallography at undergraduate level.
Information security fundamentals
Peltier, Thomas R
2013-01-01
Developing an information security program that adheres to the principle of security as a business enabler must be the first step in an enterprise's effort to build an effective security program. Following in the footsteps of its bestselling predecessor, Information Security Fundamentals, Second Edition provides information security professionals with a clear understanding of the fundamentals of security required to address the range of issues they will experience in the field.The book examines the elements of computer security, employee roles and r
Fundamentals of structural dynamics
Craig, Roy R
2006-01-01
From theory and fundamentals to the latest advances in computational and experimental modal analysis, this is the definitive, updated reference on structural dynamics.This edition updates Professor Craig's classic introduction to structural dynamics, which has been an invaluable resource for practicing engineers and a textbook for undergraduate and graduate courses in vibrations and/or structural dynamics. Along with comprehensive coverage of structural dynamics fundamentals, finite-element-based computational methods, and dynamic testing methods, this Second Edition includes new and e
Masses of Fundamental Particles
Terazawa, Hidezumi
2011-01-01
Not only the masses of fundamental particles including the weak bosons, Higgs scalar, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite model of quarks and leptons successfully. In addition, both of the two anomalies recently found by the CDF Collaboration are suggested to be taken as evidences for the substructure of the fundamental particles.
Speaking Fluently And Accurately
Institute of Scientific and Technical Information of China (English)
JosephDeVeto
2004-01-01
Even after many years of study,students make frequent mistakes in English. In addition, many students still need a long time to think of what they want to say. For some reason, in spite of all the studying, students are still not quite fluent.When I teach, I use one technique that helps students not only speak more accurately, but also more fluently. That technique is dictations.
Accurate Control of Josephson Phase Qubits
2016-04-14
61 ~1986!. 23 K. Kraus, States, Effects, and Operations: Fundamental Notions of Quantum Theory, Lecture Notes in Physics , Vol. 190 ~Springer-Verlag... PHYSICAL REVIEW B 68, 224518 ~2003!Accurate control of Josephson phase qubits Matthias Steffen,1,2,* John M. Martinis,3 and Isaac L. Chuang1 1Center...for Bits and Atoms and Department of Physics , MIT, Cambridge, Massachusetts 02139, USA 2Solid State and Photonics Laboratory, Stanford University
Atmospheric parameters of 82 red giants in the Kepler field
DEFF Research Database (Denmark)
Overaa Thygesen, Anders; Frandsen, Søren; Bruntt, Hans;
2012-01-01
Context. Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims. We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. Methods...... elements were measured using equivalent widths of the spectral lines. Results. We identify discrepancies in log g and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue (larger than 2.0 dex for log g and [Fe/H] for individual stars). The Teff found from...... spectroscopy and photometry shows good agreement within the uncertainties. We find good agreement between the spectroscopic log g and the log g derived from asteroseismology. Also, we see indications of a potential metallicity effect on the stellar oscillations. Conclusions. We have determined the fundamental...
Energy Technology Data Exchange (ETDEWEB)
Moussa, D., E-mail: djamelmoussa@gmail.com [Université des Sciences et Technologie H. Boumediene (USTHB), Laboratoire SNIRM, Faculté de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria); Damache, S. [Division de Physique, CRNA, 02 Bd. Frantz Fanon, B.P. 399 Alger-gare, Algiers (Algeria); Ouichaoui, S., E-mail: souichaoui@gmail.com [Université des Sciences et Technologie H. Boumediene (USTHB), Laboratoire SNIRM, Faculté de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria)
2015-01-15
The stopping powers of thin Al foils for H{sup +} and {sup 4}He{sup +} ions have been measured over the energy range E=(206.03–2680.05) keV/amu with an overall relative uncertainty better than 1% using the transmission method. The derived S(E) experimental data are compared to previous ones from the literature, to values derived by the SRIM-2008 code or compiled in the ICRU-49 report, and to the predictions of Sigmund–Schinner binary collision stopping theory. Besides, the S(E) data for H{sup +} ions together with those for He{sup 2+} ions reported by Andersen et al. (1977) have been analyzed over the energy interval E>1.0 MeV using the modified Bethe–Bloch stopping theory. The following sets of values have been inferred for the mean excitation potential, I, and the Barkas–Andersen parameter, b, for H{sup +} and He{sup +} projectiles, respectively: {(I=164±3)) eV, (b=1.40} and {(I=163±2.5)) eV, (b=1.38}. As expected, the I parameter is found to be independent of the projectile electronic structure presumably indicating that the contribution of charge exchange effects becomes negligible as the projectile velocity increases. Therefore, the I parameter must be determined from precise stopping power measurements performed at high projectile energies where the Bethe stopping theory is fully valid.
Variation of Fundamental Constants
Flambaum, V. V.
2006-11-01
Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.
Efficient and accurate fragmentation methods.
Pruitt, Spencer R; Bertoni, Colleen; Brorsen, Kurt R; Gordon, Mark S
2014-09-16
Conspectus Three novel fragmentation methods that are available in the electronic structure program GAMESS (general atomic and molecular electronic structure system) are discussed in this Account. The fragment molecular orbital (FMO) method can be combined with any electronic structure method to perform accurate calculations on large molecular species with no reliance on capping atoms or empirical parameters. The FMO method is highly scalable and can take advantage of massively parallel computer systems. For example, the method has been shown to scale nearly linearly on up to 131 000 processor cores for calculations on large water clusters. There have been many applications of the FMO method to large molecular clusters, to biomolecules (e.g., proteins), and to materials that are used as heterogeneous catalysts. The effective fragment potential (EFP) method is a model potential approach that is fully derived from first principles and has no empirically fitted parameters. Consequently, an EFP can be generated for any molecule by a simple preparatory GAMESS calculation. The EFP method provides accurate descriptions of all types of intermolecular interactions, including Coulombic interactions, polarization/induction, exchange repulsion, dispersion, and charge transfer. The EFP method has been applied successfully to the study of liquid water, π-stacking in substituted benzenes and in DNA base pairs, solvent effects on positive and negative ions, electronic spectra and dynamics, non-adiabatic phenomena in electronic excited states, and nonlinear excited state properties. The effective fragment molecular orbital (EFMO) method is a merger of the FMO and EFP methods, in which interfragment interactions are described by the EFP potential, rather than the less accurate electrostatic potential. The use of EFP in this manner facilitates the use of a smaller value for the distance cut-off (Rcut). Rcut determines the distance at which EFP interactions replace fully quantum
Dick, Erik
2015-01-01
This book explores the working principles of all kinds of turbomachines. The same theoretical framework is used to analyse the different machine types. Fundamentals are first presented and theoretical concepts are then elaborated for particular machine types, starting with the simplest ones.For each machine type, the author strikes a balance between building basic understanding and exploring knowledge of practical aspects. Readers are invited through challenging exercises to consider how the theory applies to particular cases and how it can be generalised. The book is primarily meant as a course book. It teaches fundamentals and explores applications. It will appeal to senior undergraduate and graduate students in mechanical engineering and to professional engineers seeking to understand the operation of turbomachines. Readers will gain a fundamental understanding of turbomachines. They will also be able to make a reasoned choice of turbomachine for a particular application and to understand its operation...
Pragmatic electrical engineering fundamentals
Eccles, William
2011-01-01
Pragmatic Electrical Engineering: Fundamentals introduces the fundamentals of the energy-delivery part of electrical systems. It begins with a study of basic electrical circuits and then focuses on electrical power. Three-phase power systems, transformers, induction motors, and magnetics are the major topics.All of the material in the text is illustrated with completely-worked examples to guide the student to a better understanding of the topics. This short lecture book will be of use at any level of engineering, not just electrical. Its goal is to provide the practicing engineer with a practi
Fundamentals of continuum mechanics
Rudnicki, John W
2014-01-01
A concise introductory course text on continuum mechanics Fundamentals of Continuum Mechanics focuses on the fundamentals of the subject and provides the background for formulation of numerical methods for large deformations and a wide range of material behaviours. It aims to provide the foundations for further study, not just of these subjects, but also the formulations for much more complex material behaviour and their implementation computationally. This book is divided into 5 parts, covering mathematical preliminaries, stress, motion and deformation, balance of mass, momentum and energ
Reis, Mario
2013-01-01
The Fundamentals of Magnetism is a truly unique reference text, that explores the study of magnetism and magnetic behavior with a depth that no other book can provide. It covers the most detailed descriptions of the fundamentals of magnetism providing an emphasis on statistical mechanics which is absolutely critical for understanding magnetic behavior. The books covers the classical areas of basic magnetism, including Landau Theory and magnetic interactions, but features a more concise and easy-to-read style. Perfect for upper-level graduate students and industry researchers, The Fu
Homeschooling and religious fundamentalism
Directory of Open Access Journals (Sweden)
Robert KUNZMAN
2010-10-01
Full Text Available This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to contemporary culture; suspicion of institutional authority and professional expertise; parental control and centrality of the family; and interweaving of faith and academics. It is important to recognize, however, that fundamentalism exists on a continuum; conservative religious homeschoolers resist liberal democratic values to varying degrees, and efforts to foster dialogue and accommodation with religious homeschoolers can ultimately helpstrengthen the broader civic fabric.
Fundamentals of nonlinear optics
Powers, Peter E
2011-01-01
Peter Powers's rigorous but simple description of a difficult field keeps the reader's attention throughout. … All chapters contain a list of references and large numbers of practice examples to be worked through. … By carefully working through the proposed problems, students will develop a sound understanding of the fundamental principles and applications. … the book serves perfectly for an introductory-level course for second- and third-order nonlinear optical phenomena. The author's writing style is refreshing and original. I expect that Fundamentals of Nonlinear Optics will fast become pop
Infosec management fundamentals
Dalziel, Henry
2015-01-01
Infosec Management Fundamentals is a concise overview of the Information Security management concepts and techniques, providing a foundational template for both experienced professionals and those new to the industry. This brief volume will also appeal to business executives and managers outside of infosec who want to understand the fundamental concepts of Information Security and how it impacts their business decisions and daily activities. Teaches ISO/IEC 27000 best practices on information security management Discusses risks and controls within the context of an overall information securi
Fundamentals of fluid lubrication
Hamrock, Bernard J.
1991-01-01
The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.
Antennas fundamentals, design, measurement
Long, Maurice
2009-01-01
This comprehensive revision (3rd Edition) is a senior undergraduate or first-year graduate level textbook on antenna fundamentals, design, performance analysis, and measurements. In addition to its use as a formal course textbook, the book's pragmatic style and emphasis on the fundamentals make it especially useful to engineering professionals who need to grasp the essence of the subject quickly but without being mired in unnecessary detail. This new edition was prepared for a first year graduate course at Southern Polytechnic State University in Georgia. It provides broad coverage of antenna
Smith, Peter
2013-01-01
Written for the piping engineer and designer in the field, this two-part series helps to fill a void in piping literature,since the Rip Weaver books of the '90s were taken out of print at the advent of the Computer Aid Design(CAD) era. Technology may have changed, however the fundamentals of piping rules still apply in the digitalrepresentation of process piping systems. The Fundamentals of Piping Design is an introduction to the designof piping systems, various processes and the layout of pipe work connecting the major items of equipment forthe new hire, the engineering student and the vetera
Variation of fundamental constants: theory
Flambaum, Victor
2008-05-01
Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.
This study guide provides comments and references for professional soil scientists who are studying for the soil science fundamentals exam needed as the first step for certification. The performance objectives were determined by the Soil Science Society of America's Council of Soil Science Examiners...
Homeschooling and Religious Fundamentalism
Kunzman, Robert
2010-01-01
This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to…
Fundamentals and Optimal Institutions
DEFF Research Database (Denmark)
Gonzalez-Eiras, Martin; Harmon, Nikolaj Arpe; Rossi, Martín
2016-01-01
of regulatory institutions such as revenue sharing, salary caps or luxury taxes. We show, theoretically and empirically, that these large differences in adopted institutions can be rationalized as optimal responses to differences in the fundamental characteristics of the sports being played. This provides...
Fundamental Metallurgy of Solidification
DEFF Research Database (Denmark)
Tiedje, Niels
2004-01-01
The text takes the reader through some fundamental aspects of solidification, with focus on understanding the basic physics that govern solidification in casting and welding. It is described how the first solid is formed and which factors affect nucleation. It is described how crystals grow from ...
Fundamentals of convolutional coding
Johannesson, Rolf
2015-01-01
Fundamentals of Convolutional Coding, Second Edition, regarded as a bible of convolutional coding brings you a clear and comprehensive discussion of the basic principles of this field * Two new chapters on low-density parity-check (LDPC) convolutional codes and iterative coding * Viterbi, BCJR, BEAST, list, and sequential decoding of convolutional codes * Distance properties of convolutional codes * Includes a downloadable solutions manual
Fundamental Physics Microgravity Sensitivity
Israelsson, Ulf
1998-01-01
An introduction followed by a brief discussion about the sensitivity to microgravity environment disturbances for some recent and planned experiments in microgravity fundamental physics will be presented. In particular, correlation between gravity disturbances and the quality of science data sets measured by the Confined Helium Experiment (CHEX) during ground testing and during the November 1997 USMP-4 flight will be described.
Fundamental partial compositeness
DEFF Research Database (Denmark)
Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea
2016-01-01
We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Unde...
Fundamentals of Business Economics
2013-01-01
Powerpoint presentations of the 9 theoretical units of the subject: Fundamentals of Business Economics. Business Administration Degree. Faculty of Economics. University of Alicante En el marco de ayudas a preparación de materiales docentes en lengua inglesa, por parte del Servei de Política Llingüística de la Universidad de Alicante
Wakker, K.F.
2015-01-01
This book deals with the motion of the center of mass of a spacecraft; this discipline is generally called astrodynamics. The book focuses on an analytical treatment of the motion of spacecraft and provides insight into the fundamentals of spacecraft orbit dynamics. A large number of topics are trea
Fundamentals of plasma physics
Bittencourt, J A
1986-01-01
A general introduction designed to present a comprehensive, logical and unified treatment of the fundamentals of plasma physics based on statistical kinetic theory. Its clarity and completeness make it suitable for self-learning and self-paced courses. Problems are included.
Energy Technology Data Exchange (ETDEWEB)
Laumer, Bernhard [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Schuster, Fabian; Stutzmann, Martin [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); Bergmaier, Andreas; Dollinger, Guenther [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Eickhoff, Martin [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)
2013-06-21
Zn{sub 1-x}Mg{sub x}O epitaxial films with Mg concentrations 0{<=}x{<=}0.3 were grown by plasma-assisted molecular beam epitaxy on a-plane sapphire substrates. Precise determination of the Mg concentration x was performed by elastic recoil detection analysis. The bandgap energy was extracted from absorption measurements with high accuracy taking electron-hole interaction and exciton-phonon complexes into account. From these results a linear relationship between bandgap energy and Mg concentration is established for x{<=}0.3. Due to alloy disorder, the increase of the photoluminescence emission energy with Mg concentration is less pronounced. An analysis of the lattice parameters reveals that the epitaxial films grow biaxially strained on a-plane sapphire.
Fundamentals of differential beamforming
Benesty, Jacob; Pan, Chao
2016-01-01
This book provides a systematic study of the fundamental theory and methods of beamforming with differential microphone arrays (DMAs), or differential beamforming in short. It begins with a brief overview of differential beamforming and some popularly used DMA beampatterns such as the dipole, cardioid, hypercardioid, and supercardioid, before providing essential background knowledge on orthogonal functions and orthogonal polynomials, which form the basis of differential beamforming. From a physical perspective, a DMA of a given order is defined as an array that measures the differential acoustic pressure field of that order; such an array has a beampattern in the form of a polynomial whose degree is equal to the DMA order. Therefore, the fundamental and core problem of differential beamforming boils down to the design of beampatterns with orthogonal polynomials. But certain constraints also have to be considered so that the resulting beamformer does not seriously amplify the sensors’ self noise and the mism...
Fundamentals of nuclear physics
Takigawa, Noboru
2017-01-01
This book introduces the current understanding of the fundamentals of nuclear physics by referring to key experimental data and by providing a theoretical understanding of principal nuclear properties. It primarily covers the structure of nuclei at low excitation in detail. It also examines nuclear forces and decay properties. In addition to fundamentals, the book treats several new research areas such as non-relativistic as well as relativistic Hartree–Fock calculations, the synthesis of super-heavy elements, the quantum chromodynamics phase diagram, and nucleosynthesis in stars, to convey to readers the flavor of current research frontiers in nuclear physics. The authors explain semi-classical arguments and derivation of its formulae. In these ways an intuitive understanding of complex nuclear phenomena is provided. The book is aimed at graduate school students as well as junior and senior undergraduate students and postdoctoral fellows. It is also useful for researchers to update their knowledge of diver...
Variation of fundamental constants
Flambaum, V V
2006-01-01
We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.
2004-01-01
Discussing what is fundamental in a variety of fields, biologist Richard Dawkins, physicist Gerardus 't Hooft, and mathematician Alain Connes spoke to a packed Main Auditorium at CERN 15 October. Dawkins, Professor of the Public Understanding of Science at Oxford University, explained simply the logic behind Darwinian natural selection, and how it would seem to apply anywhere in the universe that had the right conditions. 't Hooft, winner of the 1999 Physics Nobel Prize, outlined some of the main problems in physics today, and said he thinks physics is so fundamental that even alien scientists from another planet would likely come up with the same basic principles, such as relativity and quantum mechanics. Connes, winner of the 1982 Fields Medal (often called the Nobel Prize of Mathematics), explained how physics is different from mathematics, which he described as a "factory for concepts," unfettered by connection to the physical world. On 16 October, anthropologist Sharon Traweek shared anecdotes from her ...
Radar Fundamentals, Presentation
Jenn, David
2008-01-01
Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.
Greg Hall, D
2011-01-01
Session 1 of the 2010 STP/IFSTP Joint Symposium on Toxicologic Neuropathology, titled "Fundamentals of Neurobiology," was organized to provide a foundation for subsequent sessions by presenting essential elements of neuroanatomy and nervous system function. A brief introduction to the session titled "Introduction to Correlative Neurobiology" was provided by Dr. Greg Hall (Eli Lilly and Company, Indianapolis, IN). Correlative neurobiology refers to considerations of the relationships between the highly organized and compartmentalized structure of nervous tissues and the functioning within this system.
Fundamentals of linear algebra
Dash, Rajani Ballav
2008-01-01
FUNDAMENTALS OF LINEAR ALGEBRA is a comprehensive Text Book, which can be used by students and teachers of All Indian Universities. The Text has easy, understandable form and covers all topics of UGC Curriculum. There are lots of worked out examples which helps the students in solving the problems without anybody's help. The Problem sets have been designed keeping in view of the questions asked in different examinations.
Fundamentals of Stochastic Networks
Ibe, Oliver C
2011-01-01
An interdisciplinary approach to understanding queueing and graphical networks In today's era of interdisciplinary studies and research activities, network models are becoming increasingly important in various areas where they have not regularly been used. Combining techniques from stochastic processes and graph theory to analyze the behavior of networks, Fundamentals of Stochastic Networks provides an interdisciplinary approach by including practical applications of these stochastic networks in various fields of study, from engineering and operations management to communications and the physi
Duane Knudson
2007-01-01
DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follow...
Energy Technology Data Exchange (ETDEWEB)
Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-06-16
This is a powerpoint presentation which serves as lecture material for the Parallel Computing summer school. It goes over the fundamentals of the Monte Carlo calculation method. The material is presented according to the following outline: Introduction (background, a simple example: estimating π), Why does this even work? (The Law of Large Numbers, The Central Limit Theorem), How to sample (inverse transform sampling, rejection), and An example from particle transport.
Biomedical engineering fundamentals
Bronzino, Joseph D
2014-01-01
Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering.Biomedical Engineering Fundamentals, the first volume of the handbook, presents material from respected scientists with diverse backgrounds in physiological systems, biomechanics, biomaterials, bioelectric phenomena, and neuroengineering. More than three dozen specific topics are examined, including cardia
High voltage engineering fundamentals
Kuffel, E; Hammond, P
1984-01-01
Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over
Skripak, Stephen J.
2016-01-01
Fundamentals of Business (2016) is an openly licensed (CC BY NC SA 3.0) textbook designed for use in Virginia Tech’s Pamplin College of Business introductory level business course, MGT1104 Foundations of Business. This work is a project of University Libraries and the Pamplin College of Business, Virginia Tech.Lead Author: Stephen J. SkripakContributors: Richard Parsons, Anastasia Cortes, Anita WalzLayout: Anastasia Cortes Selected graphics: Brian Craig http://bcraigdesign.comCover design:...
Fundamentals of queueing theory
Gross, Donald; Thompson, James M; Harris, Carl M
2013-01-01
Praise for the Third Edition ""This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented.""-IIE Transactions on Operations Engineering Thoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than pre
Neutrons and Fundamental Symmetries
Energy Technology Data Exchange (ETDEWEB)
Plaster, Bradley [Univ. of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy
2016-01-11
The research supported by this project addressed fundamental open physics questions via experiments with subatomic particles. In particular, neutrons constitute an especially ideal “laboratory” for fundamental physics tests, as their sensitivities to the four known forces of nature permit a broad range of tests of the so-called “Standard Model”, our current best physics model for the interactions of subatomic particles. Although the Standard Model has been a triumphant success for physics, it does not provide satisfactory answers to some of the most fundamental open questions in physics, such as: are there additional forces of nature beyond the gravitational, electromagnetic, weak nuclear, and strong nuclear forces?, or why does our universe consist of more matter than anti-matter? This project also contributed significantly to the training of the next generation of scientists, of considerable value to the public. Young scientists, ranging from undergraduate students to graduate students to post-doctoral researchers, made significant contributions to the work carried out under this project.
Burov, Alexey
Fundamental science is a hard, long-term human adventure that has required high devotion and social support, especially significant in our epoch of Mega-science. The measure of this devotion and this support expresses the real value of the fundamental science in public opinion. Why does fundamental science have value? What determines its strength and what endangers it? The dominant answer is that the value of science arises out of curiosity and is supported by the technological progress. Is this really a good, astute answer? When trying to attract public support, we talk about the ``mystery of the universe''. Why do these words sound so attractive? What is implied by and what is incompatible with them? More than two centuries ago, Immanuel Kant asserted an inseparable entanglement between ethics and metaphysics. Thus, we may ask: which metaphysics supports the value of scientific cognition, and which does not? Should we continue to neglect the dependence of value of pure science on metaphysics? If not, how can this issue be addressed in the public outreach? Is the public alienated by one or another message coming from the face of science? What does it mean to be politically correct in this sort of discussion?
Institute of Scientific and Technical Information of China (English)
何睿; 焦艳华; 梁媛嫒; 陈灿玉
2011-01-01
理论计算有助于复杂的有机和生物系统光谱的鉴定.对于核磁共振光谱,固体结晶中的化学位移和四极耦合常数(QCC)受到邻近的分子和晶格的氢键和范德华作用较大的影响,从而显示出与气态单体分子不同的NMR参数.因此,在固体晶体NMR参数的理论计算中有必要将氢键和范德华作用这两个因素考虑进来.基于周期性方法,本文采用L-Ala-Gly二肽和硝基苯晶体作为模型体系来考察该方法计算NMR参数的精度.研究结果显示周期结构模型能够将分子间的氢键和范德华作用考虑进来,得到的化学位移和QCC值明显优于传统的单分子模型和超分子模型得到的结果,采用该方法计算的结果能够重现NMR实验结果.%Theoretical predictions are helpful for the spectroscopic identification of complicated organic and biological systems.For nuclear magnetic resonance (NMR) parameters,however,the chemical shift and quadrupole coupling constant (QCC) of the solid crystals are considerably affected by hydrogen bonding and van der Waals interactions from neighboring molecules and the crystal lattice leading to significant spectroscopic differences compared to isolated monomer molecules.Therefore,it is necessary to take these two factors into account for the precise predictions of chemical shifts and QCCs of solid crystals.L-alanylglycine dipeptide and nitrobenzene were selected as model crystals to demonstrate these effects.Here,the chemical shielding (CS) and QCC data were calculated based on the periodic structure model.The incorporation of intermolecular hydrogen bonding and crystal lattice effects by periodic models was found to be crucial in obtaining reliable predictions of CS and QCC values and rendering more explicit spectroscopic assignments for solid organic and biological systems.
Energy Technology Data Exchange (ETDEWEB)
Nope Gomez, F. I.; Santiago, C. de
2014-07-01
Shallow geothermal energy application in buildings and civil engineering works (tunnels, diaphragm walls, bridge decks, roads, and train/metro stations) are spreading rapidly all around the world. the dual role of these energy geostructures makes their design challenging and more complex with respect to conventional projects. Besides the geotechnical parameters, thermal behavior parameters are needed in the design and dimensioning to warrantee the thermo-mechanical stability of the geothermal structural element. As for obtaining any soil thermal parameter, both in situ and laboratory methods can be used. The present study focuses on a lab test known the need ke method to measure the thermal conductivity of soils (λ). Through this research work, different variables inherent to the test procedure, as well as external factors that may have an impact on thermal conductivity measurements were studied. Samples extracted from the cores obtained from a geothermal drilling conducted on the campus of the Polytechnic University of Valencia, showing different mineralogical and nature composition (granular and clayey) were studied different (moisture and density) compacting conditions. 550 thermal conductivity measurements were performed, from which the influence of factors such as the degree of saturation-moisture, dry density and type of material was verified. Finally, a stratigraphic profile with thermal conductivities ranges of each geologic level was drawn, considering the degree of saturation ranges evaluated in lab tests, in order to be compared and related to thermal response test, currently in progress. Finally, a test protocol is set and proposed, for both remolded and undisturbed samples, under different saturation conditions. Together with this test protocol, a set of recommendations regarding the configuration of the measuring equipment, treatment of samples and other variables, are posed in order to reduce errors in the final results. (Author)
Microwave engineering concepts and fundamentals
Khan, Ahmad Shahid
2014-01-01
Detailing the active and passive aspects of microwaves, Microwave Engineering: Concepts and Fundamentals covers everything from wave propagation to reflection and refraction, guided waves, and transmission lines, providing a comprehensive understanding of the underlying principles at the core of microwave engineering. This encyclopedic text not only encompasses nearly all facets of microwave engineering, but also gives all topics—including microwave generation, measurement, and processing—equal emphasis. Packed with illustrations to aid in comprehension, the book: •Describes the mathematical theory of waveguides and ferrite devices, devoting an entire chapter to the Smith chart and its applications •Discusses different types of microwave components, antennas, tubes, transistors, diodes, and parametric devices •Examines various attributes of cavity resonators, semiconductor and RF/microwave devices, and microwave integrated circuits •Addresses scattering parameters and their properties, as well a...
Directory of Open Access Journals (Sweden)
Duane Knudson
2007-09-01
Full Text Available DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follows: Part 1 Introduction: 1.Introduction to biomechanics of human movement; 2.Fundamentals of biomechanics and qualitative analysis; Part 2 Biological/Structural Bases: 3.Anatomical description and its limitations; 4.Mechanics of the musculoskeletal system; Part 3 Mechanical Bases: 5.Linear and angular kinematics; 6.Linear kinetics; 7.Angular kinetics; 8.Fluid mechanics; Part 4 Application of Biomechanics in Qualitative Analysis :9.Applying biomechanics in physical education; 10.Applying biomechanics in coaching; 11.Applying biomechanics in strength and conditioning; 12.Applying biomechanics in sports medicine and rehabilitation. AUDIENCE This is an important reading for both student and educators in the medicine, sport and exercise-related fields. For the researcher and lecturer it would be a helpful guide to plan and prepare more detailed experimental designs or lecture and/or laboratory classes in exercise and sport biomechanics. ASSESSMENT The text provides a constructive fundamental resource for biomechanics, exercise and sport-related students, teachers and researchers as well as anyone interested in understanding motion. It is also very useful since being clearly written and presenting several ways of examples of the application of biomechanics to help teach and apply biomechanical variables and concepts, including sport-related ones
Fundamental of biomedical engineering
Sawhney, GS
2007-01-01
About the Book: A well set out textbook explains the fundamentals of biomedical engineering in the areas of biomechanics, biofluid flow, biomaterials, bioinstrumentation and use of computing in biomedical engineering. All these subjects form a basic part of an engineer''s education. The text is admirably suited to meet the needs of the students of mechanical engineering, opting for the elective of Biomedical Engineering. Coverage of bioinstrumentation, biomaterials and computing for biomedical engineers can meet the needs of the students of Electronic & Communication, Electronic & Instrumenta
Fundamentals of Project Management
Heagney, Joseph
2011-01-01
With sales of more than 160,000 copies, Fundamentals of Project Management has helped generations of project managers navigate the ins and outs of every aspect of this complex discipline. Using a simple step-by-step approach, the book is the perfect introduction to project management tools, techniques, and concepts. Readers will learn how to: ò Develop a mission statement, vision, goals, and objectives ò Plan the project ò Create the work breakdown structure ò Produce a workable schedule ò Understand earned value analysis ò Manage a project team ò Control and evaluate progress at every stage.
Mathematical analysis fundamentals
Bashirov, Agamirza
2014-01-01
The author's goal is a rigorous presentation of the fundamentals of analysis, starting from elementary level and moving to the advanced coursework. The curriculum of all mathematics (pure or applied) and physics programs include a compulsory course in mathematical analysis. This book will serve as can serve a main textbook of such (one semester) courses. The book can also serve as additional reading for such courses as real analysis, functional analysis, harmonic analysis etc. For non-math major students requiring math beyond calculus, this is a more friendly approach than many math-centric o
Fundamental concepts of mathematics
Goodstein, R L
Fundamental Concepts of Mathematics, 2nd Edition provides an account of some basic concepts in modern mathematics. The book is primarily intended for mathematics teachers and lay people who wants to improve their skills in mathematics. Among the concepts and problems presented in the book include the determination of which integral polynomials have integral solutions; sentence logic and informal set theory; and why four colors is enough to color a map. Unlike in the first edition, the second edition provides detailed solutions to exercises contained in the text. Mathematics teachers and people
Fundamentals of microwave photonics
Urick, V J; McKinney , Jason D
2015-01-01
A comprehensive resource to designing andconstructing analog photonic links capable of high RFperformanceFundamentals of Microwave Photonics provides acomprehensive description of analog optical links from basicprinciples to applications. The book is organized into fourparts. The first begins with a historical perspective of microwavephotonics, listing the advantages of fiber optic links anddelineating analog vs. digital links. The second section coversbasic principles associated with microwave photonics in both the RFand optical domains. The third focuses on analog modulationformats-starti
Fundamentals of attosecond optics
Chang, Zenghu
2011-01-01
Attosecond optical pulse generation, along with the related process of high-order harmonic generation, is redefining ultrafast physics and chemistry. A practical understanding of attosecond optics requires significant background information and foundational theory to make full use of these cutting-edge lasers and advance the technology toward the next generation of ultrafast lasers. Fundamentals of Attosecond Optics provides the first focused introduction to the field. The author presents the underlying concepts and techniques required to enter the field, as well as recent research advances th
Morris, Carla C
2015-01-01
Fundamentals of Calculus encourages students to use power, quotient, and product rules for solutions as well as stresses the importance of modeling skills. In addition to core integral and differential calculus coverage, the book features finite calculus, which lends itself to modeling and spreadsheets. Specifically, finite calculus is applied to marginal economic analysis, finance, growth, and decay. Includes: Linear Equations and FunctionsThe DerivativeUsing the Derivative Exponential and Logarithmic Functions Techniques of DifferentiationIntegral CalculusIntegration TechniquesFunctions
Nanomachines fundamentals and applications
Wang, Joseph
2013-01-01
This first-hand account by one of the pioneers of nanobiotechnology brings together a wealth of valuable material in a single source. It allows fascinating insights into motion at the nanoscale, showing how the proven principles of biological nanomotors are being transferred to artificial nanodevices.As such, the author provides engineers and scientists with the fundamental knowledge surrounding the design and operation of biological and synthetic nanomotors and the latest advances in nanomachines. He addresses such topics as nanoscale propulsions, natural biomotors, molecular-scale machin
Information security fundamentals
Blackley, John A; Peltier, Justin
2004-01-01
Effective security rules and procedures do not exist for their own sake-they are put in place to protect critical assets, thereby supporting overall business objectives. Recognizing security as a business enabler is the first step in building a successful program.Information Security Fundamentals allows future security professionals to gain a solid understanding of the foundations of the field and the entire range of issues that practitioners must address. This book enables students to understand the key elements that comprise a successful information security program and eventually apply thes
Fundamentals of engineering electromagnetism
Energy Technology Data Exchange (ETDEWEB)
Kim, Nam; Yoon, Youngro; Jun, Sukhee; Jun, Hoin
2004-08-15
It indicates fundamentals of engineering electromagnetism. It mentions electromagnetic field model of introduction and International system of units and universal constant, Vector analysis with summary and orthogonal coordinate systems, electrostatic field on Coulomb's law and Gauss's law, electrostatic energy and strength, steady state current with Ohm's law and Joule's law and calculation of resistance, crystallite field with Vector's electrostatic potential, Biot-Savart law and application and Magnetic Dipole, time-Savart and Maxwell equation with potential function and Faraday law of electromagnetic induction, plane electromagnetic wave, transmission line, a wave guide and cavity resonator and antenna arrangement.
Franc, Jean-Pierre
2005-01-01
The present book is aimed at providing a comprehensive presentation of cavitation phenomena in liquid flows. It is further backed up by the experience, both experimental and theoretical, of the authors whose expertise has been internationally recognized. A special effort is made to place the various methods of investigation in strong relation with the fundamental physics of cavitation, enabling the reader to treat specific problems independently. Furthermore, it is hoped that a better knowledge of the cavitation phenomenon will allow engineers to create systems using it positively. Examples in the literature show the feasibility of this approach.
Directory of Open Access Journals (Sweden)
Carlos A. Robles Corbalá
2015-12-01
Full Text Available En este artículo se aborda un problema clásico para poder detectar si dos espacios topológicos son homeomorfos o no. Para lo cual a cada espacio topológico se le asocia un grupo algebraico, de tal suerte que si los espacios son homeomorfos, entonces los grupos asociados serán isomorfos. Se presenta una construcción del grupo fundamental de un espacio topológico y se enfoca en demostrar que efectivamente es un grupo.
Electronic circuits fundamentals & applications
Tooley, Mike
2015-01-01
Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The
Jin, Guoyong; Su, Zhu
2015-01-01
This book develops a uniform accurate method which is capable of dealing with vibrations of laminated beams, plates and shells with arbitrary boundary conditions including classical boundaries, elastic supports and their combinations. It also provides numerous solutions for various configurations including various boundary conditions, laminated schemes, geometry and material parameters, which fill certain gaps in this area of reach and may serve as benchmark solutions for the readers. For each case, corresponding fundamental equations in the framework of classical and shear deformation theory are developed. Following the fundamental equations, numerous free vibration results are presented for various configurations including different boundary conditions, laminated sequences and geometry and material properties. The proposed method and corresponding formulations can be readily extended to static analysis.
Pisacane, Vincent L.
2005-06-01
Fundamentals of Space Systems was developed to satisfy two objectives: the first is to provide a text suitable for use in an advanced undergraduate or beginning graduate course in both space systems engineering and space system design. The second is to be a primer and reference book for space professionals wishing to broaden their capabilities to develop, manage the development, or operate space systems. The authors of the individual chapters are practicing engineers that have had extensive experience in developing sophisticated experimental and operational spacecraft systems in addition to having experience teaching the subject material. The text presents the fundamentals of all the subsystems of a spacecraft missions and includes illustrative examples drawn from actual experience to enhance the learning experience. It included a chapter on each of the relevant major disciplines and subsystems including space systems engineering, space environment, astrodynamics, propulsion and flight mechanics, attitude determination and control, power systems, thermal control, configuration management and structures, communications, command and telemetry, data processing, embedded flight software, survuvability and reliability, integration and test, mission operations, and the initial conceptual design of a typical small spacecraft mission.
Fundamental measure theory for hard-sphere mixtures: a review.
Roth, Roland
2010-02-17
Hard-sphere systems are one of the fundamental model systems of statistical physics and represent an important reference system for molecular or colloidal systems with soft repulsive or attractive interactions in addition to hard-core repulsion at short distances. Density functional theory for classical systems, as one of the core theoretical approaches of statistical physics of fluids and solids, has to be able to treat such an important system successfully and accurately. Fundamental measure theory is up to date the most successful and most accurate density functional theory for hard-sphere mixtures. Since its introduction fundamental measure theory has been applied to many problems, tested against computer simulations, and further developed in many respects. The literature on fundamental measure theory is already large and is growing fast. This review aims to provide a starting point for readers new to fundamental measure theory and an overview of important developments.
Diode Laser Spectrum of the ν 1 Fundamental Band of PNO
Liu, Yuyan; Hamilton, P. A.; Davies, P. B.
2002-01-01
The diode laser spectrum of the ν1 fundamental band of the short-lived molecule PNO has been detected with 59 R- and P-branch lines accurately measured. The lines were unambiguously assigned using the rotational and distortion constants for the ground and (100) vibrational levels found previously by microwave spectroscopy. The band origin was determined to be 860.301 228(31) cm-1 from a one parameter fit. The gas phase band origin is red-shifted by approximately 4 cm-1 from the matrix value.
Fundamental dynamics: Past, present and the future — like CP violation and EDMs
Bigi, Ikaros I.
2015-04-01
Working with Kolya Uraltsev was a real 'marvel' for me in general, but in particular about CP and T violation, QCD and its impact on transitions in heavy flavor hadrons and EDMs. The goal was — and still is — to define fundamental parameters for dynamics, how to measure them and compare SM forces with New Dynamics using the best tools including our brains. The correlations of them with accurate data were crucial for Kolya. Here is a review of CP asymmetries in B, D and τ decays, the impact of perturbative and non-perturbative QCD, about EDMs till 2013 — and for the future.
Williams, J G; Patel, Y
2016-06-06
The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transition, first to plastic bending and then to plastic shear for small thicknesses and smooth chips are formed. The governing parameters are tool geometry, which is principally the wedge angle, and the material properties of elastic modulus, yield stress and fracture toughness. Friction can also be important. It is demonstrated that the cutting process may be quantified via these parameters, which could be useful in the study of cutting in biology.
An efficient and accurate method for calculating nonlinear diffraction beam fields
Energy Technology Data Exchange (ETDEWEB)
Jeong, Hyun Jo; Cho, Sung Jong; Nam, Ki Woong; Lee, Jang Hyun [Division of Mechanical and Automotive Engineering, Wonkwang University, Iksan (Korea, Republic of)
2016-04-15
This study develops an efficient and accurate method for calculating nonlinear diffraction beam fields propagating in fluids or solids. The Westervelt equation and quasilinear theory, from which the integral solutions for the fundamental and second harmonics can be obtained, are first considered. A computationally efficient method is then developed using a multi-Gaussian beam (MGB) model that easily separates the diffraction effects from the plane wave solution. The MGB models provide accurate beam fields when compared with the integral solutions for a number of transmitter-receiver geometries. These models can also serve as fast, powerful modeling tools for many nonlinear acoustics applications, especially in making diffraction corrections for the nonlinearity parameter determination, because of their computational efficiency and accuracy.
Yen, William M; Yamamoto, Hajime
2006-01-01
Drawing from the second edition of the best-selling Handbook of Phosphors, Fundamentals of Phosphors covers the principles and mechanisms of luminescence in detail and surveys the primary phosphor materials as well as their optical properties. The book addresses cutting-edge developments in phosphor science and technology including oxynitride phosphors and the impact of lanthanide level location on phosphor performance.Beginning with an explanation of the physics underlying luminescence mechanisms in solids, the book goes on to interpret various luminescence phenomena in inorganic and organic materials. This includes the interpretation of the luminescence of recently developed low-dimensional systems, such as quantum wells and dots. The book also discusses the excitation mechanisms by cathode-ray and ionizing radiation and by electric fields to produce electroluminescence. The book classifies phosphor materials according to the type of luminescence centers employed or the class of host materials used and inte...
Automotive electronics design fundamentals
Zaman, Najamuz
2015-01-01
This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs. A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.
Fundamentals of quantum mechanics
House, J E
2017-01-01
Fundamentals of Quantum Mechanics, Third Edition is a clear and detailed introduction to quantum mechanics and its applications in chemistry and physics. All required math is clearly explained, including intermediate steps in derivations, and concise review of the math is included in the text at appropriate points. Most of the elementary quantum mechanical models-including particles in boxes, rigid rotor, harmonic oscillator, barrier penetration, hydrogen atom-are clearly and completely presented. Applications of these models to selected “real world” topics are also included. This new edition includes many new topics such as band theory and heat capacity of solids, spectroscopy of molecules and complexes (including applications to ligand field theory), and small molecules of astrophysical interest.
Lasers Fundamentals and Applications
Thyagarajan, K
2010-01-01
Lasers: Fundamentals and Applications, serves as a vital textbook to accompany undergraduate and graduate courses on lasers and their applications. Ever since their invention in 1960, lasers have assumed tremendous importance in the fields of science, engineering and technology because of their diverse uses in basic research and countless technological applications. This book provides a coherent presentation of the basic physics behind the way lasers work, and presents some of their most important applications in vivid detail. After reading this book, students will understand how to apply the concepts found within to practical, tangible situations. This textbook includes worked-out examples and exercises to enhance understanding, and the preface shows lecturers how to most beneficially match the textbook with their course curricula. The book includes several recent Nobel Lectures, which will further expose students to the emerging applications and excitement of working with lasers. Students who study lasers, ...
Superconductivity fundamentals and applications
Buckel, Werner
2004-01-01
This is the second English edition of what has become one of the definitive works on superconductivity in German -- currently in its sixth edition. Comprehensive and easy to understand, this introductory text is written especially with the non-specialist in mind. The authors, both long-term experts in this field, present the fundamental considerations without the need for extensive mathematics, describing the various phenomena connected with the superconducting state, with liberal insertion of experimental facts and examples for modern applications. While all fields of superconducting phenomena are dealt with in detail, this new edition pays particular attention to the groundbreaking discovery of magnesium diboride and the current developments in this field. In addition, a new chapter provides an overview of the elements, alloys and compounds where superconductivity has been observed in experiments, together with their major characteristics. The chapter on technical applications has been considerably expanded...
Fundamental partial compositeness
Sannino, Francesco
2016-01-01
We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Successful models exist because gauge quantum numbers of Standard Model fermions admit a minimal enough 'square root'. Furthermore, right-handed SM fermions have an SU(2)$_R$-like structure, yielding a custodially-protected composite Higgs. Baryon and lepton numbers arise accidentally. Standard Model fermions acquire mass at tree level, while the Higgs potential and flavor violations are generated by quantum corrections. We further discuss accidental symmetries and other dynamical features stemming from the new strongly interacting scalars. If the same phenomenology can be obtained from models without our elementary scalars, they would reappear as composite states.
Fundamentals of sustainable neighbourhoods
Friedman, Avi
2015-01-01
This book introduces architects, engineers, builders, and urban planners to a range of design principles of sustainable communities and illustrates them with outstanding case studies. Drawing on the author’s experience as well as local and international case studies, Fundamentals of Sustainable Neighbourhoods presents planning concepts that minimize developments' carbon footprint through compact communities, adaptable and expandable dwellings, adaptable landscapes, and smaller-sized yet quality-designed housing. This book also: Examines in-depth global strategies for minimizing the residential carbon footprint, including district heating, passive solar gain, net-zero residences, as well as preserving the communities' natural assets Reconsiders conceptual approaches in building design and urban planning to promote a better connection between communities and nature Demonstrates practical applications of green architecture Focuses on innovative living spaces in urban environments
Fundamentals of Fire Phenomena
DEFF Research Database (Denmark)
Quintiere, James
discipline. It covers thermo chemistry including mixtures and chemical reactions; Introduces combustion to the fire protection student; Discusses premixed flames and spontaneous ignition; Presents conservation laws for control volumes, including the effects of fire; Describes the theoretical bases...... analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...... for empirical aspects of the subject of fire; Analyses ignition of liquids and the importance of evaporation including heat and mass transfer; Features the stages of fire in compartments, and the role of scale modelling in fire. The book is written by Prof. James G. Quintiere from University of Maryland...
Developing Accurate Spatial Maps of Cotton Fiber Quality Parameters
Awareness of the importance of cotton fiber quality (Gossypium, L. sps.) has increased as advances in spinning technology require better quality cotton fiber. Recent advances in geospatial information sciences allow an improved ability to study the extent and causes of spatial variability in fiber p...
Fundamental Physics with the Laser Astrometric Test Of Relativity
Turyshev, S G; Lämmerzahl, C; Theil, S; Ertmer, W; Rasel, E; Foerstner, R; Johann, U; Klioner, S A; Soffel, M H; Dachwald, B; Seboldt, W; Perlick, V; Sandford, M C W; Bingham, R; Kent, B; Sumner, T J; Bertolami, O; Páramos, J; Christophe, B; Foulon, B; Touboul, P; Bouyer, P; Damour, T; Salomon, C; Reynaud, S; Brillet, A; Bondu, F; Mangin, J F; Samain, E; Bertotti, B; Iess, L; Erd, C; Grenouilleau, J C; Izzo, D; Rathke, A; Asmar, S W; Colavita, M; Gursel, Y; Hemmati, H; Shao, M; Williams, J G; Nordtvedt, K L; Shapiro, I; Reasenberg, R; Drever, R W P; Degnan, J; Plowman, J E; Hellings, R; Murphy, T W; Rovisco Pais, A; Copernic, A N; Favata, F; Turyshev, Slava G.; Dittus, Hansjoerg
2005-01-01
The Laser Astrometric Test Of Relativity (LATOR) is a European-U.S. Michelson-Morley-type experiment designed to test the pure tensor metric nature of gravitation - the fundamental postulate of Einstein's theory of general relativity. By using a combination of independent time-series of highly accurate gravitational deflection of light in the immediate proximity to the Sun along with measurements of the Shapiro time delay on the interplanetary scales (to a precision respectively better than 0.1 picoradians and 1 cm), LATOR will significantly improve our knowledge of relativistic gravity. The primary mission objective is to i) measure the key post-Newtonian Eddington parameter \\gamma with accuracy of a part in 10^9. (1-\\gamma) is a direct measure for presence of a new interaction in gravitational theory, and, in its search, LATOR goes a factor 30,000 beyond the present best result, Cassini's 2003 test. The mission will also provide: ii) first measurement of gravity's non-linear effects on light to ~0.01% accur...
Fundamental Aspects of Biosensors
K.Sowjanya; Aruna Kumari Yadla
2016-01-01
A biosensor is an analytical device which converts a biological response into an electrical signal. The term 'biosensor' is often used to cover sensor devices used in order to determine the concentration of substances and other parameters of biological interest even where they do not utilize a biological system directly. This very broad definition is used by some scientific journals (e.g. Biosensors, Elsevier Applied Science) but will not be applied to the coverage here. The empha...
Fundamentals of ergonomic exoskeleton robots
Schiele, A.
2008-01-01
This thesis is the first to provide the fundamentals of ergonomic exoskeleton design. The fundamental theory as well as technology necessary to analyze and develop ergonomic wearable robots interacting with humans is established and validated by experiments and prototypes. The fundamentals are (1) a
Revisiting energy efficiency fundamentals
Energy Technology Data Exchange (ETDEWEB)
Perez-Lombard, L.; Velazquez, D. [Grupo de Termotecnia, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Ortiz, J. [Building Research Establishment (BRE), Garston, Watford, WD25 9XX (United Kingdom)
2013-05-15
Energy efficiency is a central target for energy policy and a keystone to mitigate climate change and to achieve a sustainable development. Although great efforts have been carried out during the last four decades to investigate the issue, focusing into measuring energy efficiency, understanding its trends and impacts on energy consumption and to design effective energy efficiency policies, many energy efficiency-related concepts, some methodological problems for the construction of energy efficiency indicators (EEI) and even some of the energy efficiency potential gains are often ignored or misunderstood, causing no little confusion and controversy not only for laymen but even for specialists. This paper aims to revisit, analyse and discuss some efficiency fundamental topics that could improve understanding and critical judgement of efficiency stakeholders and that could help in avoiding unfounded judgements and misleading statements. Firstly, we address the problem of measuring energy efficiency both in qualitative and quantitative terms. Secondly, main methodological problems standing in the way of the construction of EEI are discussed, and a sequence of actions is proposed to tackle them in an ordered fashion. Finally, two key topics are discussed in detail: the links between energy efficiency and energy savings, and the border between energy efficiency improvement and renewable sources promotion.
Fundamental Limits of Cooperation
Lozano, Angel; Andrews, Jeffrey G
2012-01-01
Cooperation is viewed as a key ingredient for interference management in wireless systems. This paper shows that cooperation has fundamental limitations. The main result is that even full cooperation between transmitters cannot in general change an interference-limited network to a noise-limited network. The key idea is that there exists a spectral efficiency upper bound that is independent of the transmit power. First, a spectral efficiency upper bound is established for systems that rely on pilot-assisted channel estimation; in this framework, cooperation is shown to be possible only within clusters of limited size, which are subject to out-of-cluster interference whose power scales with that of the in-cluster signals. Second, an upper bound is also shown to exist when cooperation is through noncoherent communication; thus, the spectral efficiency limitation is not a by-product of the reliance on pilot-assisted channel estimation. Consequently, existing literature that routinely assumes the high-power spect...
Petitjean, Patrick; Wang, F. Y.; Wu, X. F.; Wei, J. J.
2016-12-01
Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So, they are unique tools to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal evolution of the Universe. First, they can be used to constrain the history of cosmic acceleration and the evolution of dark energy in a redshift range hardly achievable by other cosmological probes. Second, long GRBs are believed to be formed by collapse of massive stars. So they can be used to derive the high-redshift star formation rate, which can not be probed by current observations. Moreover, the use of GRBs as cosmological tools could unveil the reionization history and metal evolution of the Universe, the intergalactic medium (IGM) properties and the nature of first stars in the early universe. But beyond that, the GRB high-energy photons can be applied to constrain Lorentz invariance violation (LIV) and to test Einstein's Equivalence Principle (EEP). In this paper, we review the progress on the GRB cosmology and fundamental physics probed by GRBs.
Fundamentals of klystron testing
Energy Technology Data Exchange (ETDEWEB)
Caldwell, J.W. Jr.
1978-08-01
Fundamentals of klystron testing is a text primarily intended for the indoctrination of new klystron group test stand operators. It should significantly reduce the familiarization time of a new operator, making him an asset to the group sooner than has been experienced in the past. The new employee must appreciate the mission of SLAC before he can rightfully be expected to make a meaningful contribution to the group's effort. Thus, the introductory section acquaints the reader with basic concepts of accelerators in general, then briefly describes major physical aspects of the Stanford Linear Accelerator. Only then is his attention directed to the klystron, with its auxiliary systems, and the rudiments of klystron tube performance checks. It is presumed that the reader is acquainted with basic principles of electronics and scientific notation. However, to preserve the integrity of an indoctrination guide, tedious technical discussions and mathematical analysis have been studiously avoided. It is hoped that the new operator will continue to use the text for reference long after his indoctrination period is completed. Even the more experienced operator should find that particular sections will refresh his understanding of basic principles of klystron testing.
Realization of Quadrature Signal Generator Using Accurate Magnitude Integrator
DEFF Research Database (Denmark)
Xin, Zhen; Yoon, Changwoo; Zhao, Rende
2016-01-01
-signal parameters, espically when a fast resonse is required for usages such as grid synchronization. As a result, the parameters design of the SOGI-QSG becomes complicated. Theoretical analysis shows that it is caused by the inaccurate magnitude-integration characteristic of the SOGI-QSG. To solve this problem......, an Accurate-Magnitude-Integrator based QSG (AMI-QSG) is proposed. The AMI has an accurate magnitude-integration characteristic for the sinusoidal signal, which makes the AMI-QSG possess an accurate First-Order-System (FOS) characteristic in terms of magnitude than the SOGI-QSG. The parameter design process...
Fundamental solutions of linear partial differential operators theory and practice
Ortner, Norbert
2015-01-01
This monograph provides the theoretical foundations needed for the construction of fundamental solutions and fundamental matrices of (systems of) linear partial differential equations. Many illustrative examples also show techniques for finding such solutions in terms of integrals. Particular attention is given to developing the fundamentals of distribution theory, accompanied by calculations of fundamental solutions. The main part of the book deals with existence theorems and uniqueness criteria, the method of parameter integration, the investigation of quasihyperbolic systems by means of Fourier and Laplace transforms, and the representation of fundamental solutions of homogeneous elliptic operators with the help of Abelian integrals. In addition to rigorous distributional derivations and verifications of fundamental solutions, the book also shows how to construct fundamental solutions (matrices) of many physically relevant operators (systems), in elasticity, thermoelasticity, hexagonal/cubic elastodynamics...
Fundamentals of Space Medicine
Clément, Gilles
2005-03-01
A total of more than 240 human space flights have been completed to date, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This readable text presents the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardio-vascular, bone, and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated, and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination of both the
Directory of Open Access Journals (Sweden)
F. TopsÃƒÂ¸e
2001-09-01
Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over
FUNDPAR: A program for Deriving Fundamental Parameters from Equivalent Widths
Directory of Open Access Journals (Sweden)
C. Saffe
2011-01-01
Full Text Available Implementamos un programa en Fortran que determina parámetros fundamentales de estrellas de tipo solar, a partir de anchos equivalentes del Fe. La solución debe verificar tres condiciones en el método estándar: equilibrio de ionización, equilibrio de excitación e independencia entre abundancias y anchos equivalentes. Calculamos modelos de atmósfera de Kurucz con opacidades NEWODF. Detalles como el parámetro de longitud de mezcla, el sobre impulso convectivo, etc. se calculan con un programa independiente. FUNDPAR calcula las incertezas por dos métodos: el criterio de Gonzalez & Vanture (1998 y utilizando la función X² . Los resultados derivados con FUNDPAR están de acuerdo con determinaciones previas en la literatura. En particular obtuvimos parámetros fundamentales de 58 estrellas con exoplanetas. El programa está disponible en la red1.
The Angular Diameter and Fundamental Parameters of Sirius A
Davis, J; North, J R; Robertson, J G; Tango, W J; Tuthill, P G
2010-01-01
The Sydney University Stellar Interferometer (SUSI) has been used to make a new determination of the angular diameter of Sirius A. The observations were made at an effective wavelength of 694.1 nm and the new value for the limb-darkened angular diameter is 6.048 +/- 0.040mas (+/-0.66%). This new result is compared with previous measurements and is found to be in excellent agreement with a conventionally calibrated measurement made with the European Southern Observatory's Very Large Telescope Interferometer (VLTI) at 2.176 microns (but not with a second globally calibrated VLTI measurement). A weighted mean of the SUSI and first VLTI results gives the limb-darkened angular diameter of Sirius A as 6.041 +/- 0.017mas (+/-0.28%). Combination with the Hipparcos parallax gives the radius equal to 1.713 +/- 0.009R_sun. The bolometric flux has been determined from published photometry and spectrophotometry and, combined with the angular diameter, yields the emergent flux at the stellar surface equal to (5.32+/- 0.14)...
Using fundamental equations to describe basic phenomena
DEFF Research Database (Denmark)
Jakobsen, Arne; Rasmussen, Bjarne D.
1999-01-01
constraining the total charge of refrigerant in the system, which is missing.In traditional mathematical modelling of a refrigeration cycle/system, the influence from the total charge of refrigerant on the system behaviour is normally not modelled explicitly. Instead, parameters such as superheat......When the fundamental thermodynamic balance equations (mass, energy, and momentum) are used to describe the processes in a simple refrigeration system, then one finds that the resulting equation system will have a degree of freedom equal to one. Further investigations reveal that it is the equation...... and the before mentioned parameters. In doing so, a systematic use of control volumes for modelling a refrigeration system is outlined....
Communication technology update and fundamentals
Grant, August E
2010-01-01
New communication technologies are being introduced at an astonishing rate. Making sense of these technologies is increasingly difficult. Communication Technology Update and Fundamentals is the single best source for the latest developments, trends, and issues in communication technology. Featuring the fundamental framework along with the history and background of communication technologies, Communication Technology Update and Fundamentals, 12th edition helps you stay ahead of these ever-changing and emerging technologies.As always, every chapter ha
Fundamental properties of nearby single early B-type stars
Nieva, María-Fernanda; Przybilla, Norbert
2014-06-01
Aims: Fundamental parameters of a sample of 26 apparently slowly-rotating single early B-type stars in OB associations and in the field within a distance of ≲400 pc from the Sun are presented and compared to high-precision data from detached eclipsing binaries (DEBs). Together with surface abundances for light elements the data are used to discuss the evolutionary status of the stars in context of the most recent Geneva grid of models for core hydrogen-burning stars in the mass-range ~6 to 18 M⊙ at metallicity Z = 0.014. Methods: The fundamental parameters are derived on the basis of accurate and precise atmospheric parameters determined earlier by us from non-LTE analyses of high-quality spectra of the sample stars, utilising the new Geneva stellar evolution models. Results: Evolutionary masses plus radii and luminosities are determined to better than typically 5%, 10%, and 20% uncertainty, respectively, facilitating the mass-radius and mass-luminosity relationships to be recovered for single core hydrogen-burning objects with a similar precision as derived from DEBs. Good agreement between evolutionary and spectroscopic masses is found. Absolute visual and bolometric magnitudes are derived to typically ~0.15-0.20 mag uncertainty. Metallicities are constrained to better than 15-20% uncertainty and tight constraints on evolutionary ages of the stars are provided. Overall, the spectroscopic distances and ages of individual sample stars agree with independently derived values for the host OB associations. Signatures of mixing with CN-cycled material are found in 1/3 of the sample stars. Typically, these are consistent with the amount predicted by the new Geneva models with rotation. The presence of magnetic fields appears to augment the mixing efficiency. In addition, a few objects are possibly the product of binary evolution. In particular, the unusual characteristics of τ Sco point to a blue straggler nature, due to a binary merger. Conclusions: The accuracy
Fundamentals and Techniques of Nonimaging
Energy Technology Data Exchange (ETDEWEB)
O' Gallagher, J. J.; Winston, R.
2003-07-10
other system parameter permits the construction of whole new classes of devices with greatly expanded capabilities compared to conventional approaches. These ''tailored edge-ray'' designs have dramatically broadened the range of geometries in which nonimaging optics can provide a significant performance improvement. Considerable progress continues to be made in furthering the incorporation of nonimaging secondaries into practical high concentration and ultra-high concentration solar collector systems. In parallel with the continuing development of nonimaging geometrical optics, our group has been working to develop an understanding of certain fundamental physical optics concepts in the same context. In particular, our study of the behavior of classical radiance in nonimaging systems, has revealed some fundamentally important new understandings that we have pursued both theoretically and experimentally. The field is still relatively new and is rapidly gaining widespread recognition because it fuels many industrial applications. Because of this, during the final years of the project, our group at Chicago has been working more closely with a team of industrial scientists from Science Applications International Corporation (SAIC) at first informally, and later more formally, beginning in 1998, under a formal program initiated by the Department of Energy and incrementally funded through this existing grant. This collaboration has been very fruitful and has led to new conceptual breakthroughs which have provided the foundation for further exciting growth. Many of these concepts are described in some detail in the report.
Fundamental mechanisms of micromachine reliability
Energy Technology Data Exchange (ETDEWEB)
DE BOER,MAARTEN P.; SNIEGOWSKI,JEFFRY J.; KNAPP,JAMES A.; REDMOND,JAMES M.; MICHALSKE,TERRY A.; MAYER,THOMAS K.
2000-01-01
Due to extreme surface to volume ratios, adhesion and friction are critical properties for reliability of Microelectromechanical Systems (MEMS), but are not well understood. In this LDRD the authors established test structures, metrology and numerical modeling to conduct studies on adhesion and friction in MEMS. They then concentrated on measuring the effect of environment on MEMS adhesion. Polycrystalline silicon (polysilicon) is the primary material of interest in MEMS because of its integrated circuit process compatibility, low stress, high strength and conformal deposition nature. A plethora of useful micromachined device concepts have been demonstrated using Sandia National Laboratories' sophisticated in-house capabilities. One drawback to polysilicon is that in air the surface oxidizes, is high energy and is hydrophilic (i.e., it wets easily). This can lead to catastrophic failure because surface forces can cause MEMS parts that are brought into contact to adhere rather than perform their intended function. A fundamental concern is how environmental constituents such as water will affect adhesion energies in MEMS. The authors first demonstrated an accurate method to measure adhesion as reported in Chapter 1. In Chapter 2 through 5, they then studied the effect of water on adhesion depending on the surface condition (hydrophilic or hydrophobic). As described in Chapter 2, they find that adhesion energy of hydrophilic MEMS surfaces is high and increases exponentially with relative humidity (RH). Surface roughness is the controlling mechanism for this relationship. Adhesion can be reduced by several orders of magnitude by silane coupling agents applied via solution processing. They decrease the surface energy and render the surface hydrophobic (i.e. does not wet easily). However, only a molecular monolayer coats the surface. In Chapters 3-5 the authors map out the extent to which the monolayer reduces adhesion versus RH. They find that adhesion is
Laser-fundamentals and applications
Energy Technology Data Exchange (ETDEWEB)
Schinagl, W.
1982-09-01
The survey article gives an introduction to laser technology. Fundamentals and physical aspects are discussed at large. After a brief historical review and a discussion of the physical fundamentals, important types of laser, characteristics of laser radiation and its applications in medicine are discussed.
Fundamental properties of short-lived subatomic particles
Ceci, S; Osmanović, H; Percan, A; Zauner, B
2016-01-01
Two distinct sets of properties are used to describe short-lived particles: the pole and the Breit-Wigner parameters. There is an ongoing decades-old debate on which of them is fundamental. All resonances, from excited hydrogen nuclei hit by ultra-high energy gamma rays in deep space, to new particles produced in Large Hadron Collider, should be described by the same fundamental physical quantities. In this study of nucleon resonances we discover an intricate interplay of the parameters from the both sets, and realize that neither set is fundamental on its own.
The Fundamental Scale of Descriptions
Febres, Gerardo
2014-01-01
The complexity of a system description is a function of the entropy of its symbolic description. Prior to computing the entropy of the system description, an observation scale has to be assumed. In natural language texts, typical scales are binary, characters, and words. However, considering languages as structures built around certain preconceived set of symbols, like words or characters, is only a presumption. This study depicts the notion of the Description Fundamental Scale as a set of symbols which serves to analyze the essence a language structure. The concept of Fundamental Scale is tested using English and MIDI music texts by means of an algorithm developed to search for a set of symbols, which minimizes the system observed entropy, and therefore best expresses the fundamental scale of the language employed. Test results show that it is possible to find the Fundamental Scale of some languages. The concept of Fundamental Scale, and the method for its determination, emerges as an interesting tool to fac...
Fundamental Plane of Sunyaev-Zeldovich clusters
Afshordi, Niayesh
2007-01-01
Sunyaev-Zel'dovich (SZ) cluster surveys are considered among the most promising methods for probing dark energy up to large redshifts. However, their premise is hinged upon an accurate mass-observable relationship, which could be affected by the (rather poorly understood) physics of the intracluster gas. In this letter, using a semi-analytic model of the intracluster gas that accommodates various theoretical uncertainties, I develop a Fundamental Plane relationship between the observed size, thermal energy, and mass of galaxy clusters. In particular, I find that M ~ (Y_{SZ}/R_{SZ,2})^{3/4}, where M is the mass, Y_{SZ} is the total SZ flux or thermal energy, and R_{SZ,2} is the SZ half-light radius of the cluster. I show that, within this model, using the Fundamental Plane relationship reduces the (systematic+random) errors in mass estimates to 14%, from 22% for a simple mass-flux relationship. Since measurement of the cluster sizes is an inevitable part of observing the SZ clusters, the Fundamental Plane rela...
Fundamental and composite scalars from extra dimensions
Energy Technology Data Exchange (ETDEWEB)
Aranda, Alfredo [Dual C-P Institute of High Energy Physics, Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico)], E-mail: fefo@ucol.mx; Diaz-Cruz, J.L. [Dual C-P Institute of High Energy Physics, Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico); Dual C-P Institute of High Energy Physics, Facultad de Ciencias Fisico-Matematicas, BUAP, Apdo. Postal 1364, C.P. 72000 Puebla, Pue (Mexico)], E-mail: lorenzo.diaz@fcfm.buap.mx; Hernandez-Sanchez, J. [Dual C-P Institute of High Energy Physics, Centro de Investigacion en Matematicas, Universidad Autonoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo km. 4.5, C.P. 42184, Pachuca, Hidalgo (Mexico)], E-mail: jaimeh@uaeh.edu.mx; Noriega-Papaqui, R. [Dual C-P Institute of High Energy Physics, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 Mexico D.F. (Mexico)], E-mail: rnoriega@fisica.unam.mx
2007-12-13
We discuss a scenario consisting of an effective 4D theory containing fundamental and composite fields. The strong dynamics sector responsible for the compositeness is assumed to be of extra dimensional origin. In the 4D effective theory the SM fermion and gauge fields are taken as fundamental fields. The scalar sector of the theory resembles a bosonic topcolor in the sense there are two scalar Higgs fields, a composite scalar field and a fundamental gauge-Higgs unification scalar. A detailed analysis of the scalar spectrum is presented in order to explore the parameter space consistent with experiment. It is found that, under the model assumptions, the acceptable parameter space is quite constrained. As a part of our phenomenological study of the model, we evaluate the branching ratio of the lightest Higgs boson and find that our model predicts a large FCNC mode h{yields}tc, which can be as large as O(10{sup -3}). Similarly, a large BR for the top FCNC decay is obtained, namely BR(t{yields}c+H){approx_equal}10{sup -4}.
Accurate pose estimation for forensic identification
Merckx, Gert; Hermans, Jeroen; Vandermeulen, Dirk
2010-04-01
In forensic authentication, one aims to identify the perpetrator among a series of suspects or distractors. A fundamental problem in any recognition system that aims for identification of subjects in a natural scene is the lack of constrains on viewing and imaging conditions. In forensic applications, identification proves even more challenging, since most surveillance footage is of abysmal quality. In this context, robust methods for pose estimation are paramount. In this paper we will therefore present a new pose estimation strategy for very low quality footage. Our approach uses 3D-2D registration of a textured 3D face model with the surveillance image to obtain accurate far field pose alignment. Starting from an inaccurate initial estimate, the technique uses novel similarity measures based on the monogenic signal to guide a pose optimization process. We will illustrate the descriptive strength of the introduced similarity measures by using them directly as a recognition metric. Through validation, using both real and synthetic surveillance footage, our pose estimation method is shown to be accurate, and robust to lighting changes and image degradation.
Fundamental principles of heat transfer
Whitaker, Stephen
1977-01-01
Fundamental Principles of Heat Transfer introduces the fundamental concepts of heat transfer: conduction, convection, and radiation. It presents theoretical developments and example and design problems and illustrates the practical applications of fundamental principles. The chapters in this book cover various topics such as one-dimensional and transient heat conduction, energy and turbulent transport, forced convection, thermal radiation, and radiant energy exchange. There are example problems and solutions at the end of every chapter dealing with design problems. This book is a valuable int
Fundamentals of technology project management
Garton, Colleen
2012-01-01
Designed to provide software engineers, students, and IT professionals with an understanding of the fundamentals of project management in the technology/IT field, this book serves as a practical introduction to the subject. Updated with information on how Fundamentals of Project Management integrates with and complements Project Management Institute''s Project Management Body of Knowledge, this collection explains fundamental methodologies and techniques while also discussing new technology, tools, and virtual work environments. Examples and case studies are based on technology projects, and t
Energy Technology Data Exchange (ETDEWEB)
Puzzarini, Cristina [Dipartimento di Chimica " Giacomo Ciamician," Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Biczysko, Malgorzata; Bloino, Julien; Barone, Vincenzo, E-mail: cristina.puzzarini@unibo.it [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)
2014-04-20
In an effort to provide an accurate spectroscopic characterization of oxirane, state-of-the-art computational methods and approaches have been employed to determine highly accurate fundamental vibrational frequencies and rotational parameters. Available experimental data were used to assess the reliability of our computations, and an accuracy on average of 10 cm{sup –1} for fundamental transitions as well as overtones and combination bands has been pointed out. Moving to rotational spectroscopy, relative discrepancies of 0.1%, 2%-3%, and 3%-4% were observed for rotational, quartic, and sextic centrifugal-distortion constants, respectively. We are therefore confident that the highly accurate spectroscopic data provided herein can be useful for identification of oxirane in Titan's atmosphere and the assignment of unidentified infrared bands. Since oxirane was already observed in the interstellar medium and some astronomical objects are characterized by very high D/H ratios, we also considered the accurate determination of the spectroscopic parameters for the mono-deuterated species, oxirane-d1. For the latter, an empirical scaling procedure allowed us to improve our computed data and to provide predictions for rotational transitions with a relative accuracy of about 0.02% (i.e., an uncertainty of about 40 MHz for a transition lying at 200 GHz).
Fundamental approach to discrete mathematics
Acharjya, DP
2005-01-01
Salient Features Mathematical logic, fundamental concepts, proofs and mathematical induction (Chapter 1) Set theory, fundamental concepts, theorems, proofs, Venn diagrams, product of sets, application of set theory and fundamental products (Chapter 2) An introduction to binary relations and concepts, graphs, arrow diagrams, relation matrix, composition of relations, types of relation, partial order relations, total order relation, closure of relations, poset, equivalence classes and partitions. (Chapter 3) An introduction to functions and basic concepts, graphs, composition of functions, floor and ceiling function, characteristic function, remainder function, signum function and introduction to hash function. (Chapter 4) The algebraic structure includes group theory and ring theory. Group theory includes group, subgroups, cyclic group, cosets, homomorphism, introduction to codes and group codes and error correction for block code. The ring theory includes general definition, fundamental concepts, integra...
Quantum mechanics I the fundamentals
Rajasekar, S
2015-01-01
Quantum Mechanics I: The Fundamentals provides a graduate-level account of the behavior of matter and energy at the molecular, atomic, nuclear, and sub-nuclear levels. It covers basic concepts, mathematical formalism, and applications to physically important systems.
Fast, Accurate and Detailed NoC Simulations
Wolkotte, P.T.; Hölzenspies, P.K.F.; Smit, G.J.M.; Kellenberger, P.
2007-01-01
Network-on-Chip (NoC) architectures have a wide variety of parameters that can be adapted to the designer's requirements. Fast exploration of this parameter space is only possible at a high-level and several methods have been proposed. Cycle and bit accurate simulation is necessary when the actual r
Expected Devaluation and Economic Fundamentals
Alun H. Thomas
1993-01-01
Recent incidents of exchange rate collapse have provoked interest in the extent to which such events are determined by economic fundamentals. This paper considers whether interest rate differentials are appropriate measures of the risk of devaluation and whether this measure of devaluation risk reflects the movements of variables which capture internal and external balance. The paper finds that interest rate differentials reflect devaluation risk but that movements in fundamental variables ha...
Conjugated polyelectrolytes fundamentals and applications
Liu, Bin
2013-01-01
This is the first monograph to specifically focus on fundamentals and applications of polyelectrolytes, a class of molecules that gained substantial interest due to their unique combination of properties. Combining both features of organic semiconductors and polyelectrolytes, they offer a broad field for fundamental research as well as applications to analytical chemistry, optical imaging, and opto-electronic devices. The initial chapters introduce readers to the synthesis, optical and electrical properties of various conjugated polyelectrolytes. This is followed by chapters on the applica
Energy Technology Data Exchange (ETDEWEB)
Puzzarini, Cristina [Dipartimento di Chimica " Giacomo Ciamician," Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Ali, Ashraf [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Biczysko, Malgorzata; Barone, Vincenzo, E-mail: cristina.puzzarini@unibo.it [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)
2014-09-10
An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10 cm{sup –1} for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.
Fundamental physics in particle traps
Vogel, Manuel
2014-01-01
This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.
Fundamental units: physics and metrology
Okun, Lev Borisovich
2003-01-01
The problem of fundamental units is discussed in the context of achievements of both theoretical physics and modern metrology. On one hand, due to fascinating accuracy of atomic clocks, the traditional macroscopic standards of metrology (second, metre, kilogram) are giving way to standards based on fundamental units of nature: velocity of light $c$ and quantum of action $h$. On the other hand, the poor precision of gravitational constant $G$, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use $G$ as a fundamental dimensional constant in metrology. The electromagnetic units in SI are actually based on concepts of prerelativistic classical electrodynamics such as ether, electric permitivity and magnetic permeability of vacuum. Concluding remarks are devoted to terminological confusion which accompanies the progress in basic physics and metrology.
RFID design fundamentals and applications
Lozano-Nieto, Albert
2010-01-01
RFID is an increasingly pervasive tool that is now used in a wide range of fields. It is employed to substantiate adherence to food preservation and safety standards, combat the circulation of counterfeit pharmaceuticals, and verify authenticity and history of critical parts used in aircraft and other machinery-and these are just a few of its uses. Goes beyond deployment, focusing on exactly how RFID actually worksRFID Design Fundamentals and Applications systematically explores the fundamental principles involved in the design and characterization of RFID technologies. The RFID market is expl
Fundamental approach to discrete mathematics
Acharjya, DP
2009-01-01
About the Book: The book `Fundamental Approach to Discrete Mathematics` is a required part of pursuing a computer science degree at most universities. It provides in-depth knowledge to the subject for beginners and stimulates further interest in the topic. The salient features of this book include: Strong coverage of key topics involving recurrence relation, combinatorics, Boolean algebra, graph theory and fuzzy set theory. Algorithms and examples integrated throughout the book to bring clarity to the fundamental concepts. Each concept and definition is followed by thoughtful examples.
Fundamental Research and Developing Countries
Narison, Stéphan
2002-01-01
In the first part of this report, I discuss the sociological role of fundamental research in Developing Countries (DC) and how to realize this program. In the second part, I give a brief and elementary introduction to the field of high-energy physics (HEP), accessible to a large audience not necessary physicists. The aim of this report is to make politicians and financial backers aware on the long-term usefulness of fundamental research in DC and on the possible globalisation of HEP and, in general, of science.
Astrophysical probes of fundamental physics
Energy Technology Data Exchange (ETDEWEB)
Martins, C.J.A.P. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2009-10-15
I review the motivation for varying fundamental couplings and discuss how these measurements can be used to constrain fundamental physics scenarios that would otherwise be inaccessible to experiment. I highlight the current controversial evidence for varying couplings and present some new results. Finally I focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements might be used to probe the nature of dark energy, with some advantages over standard methods. In particular I discuss what can be achieved with future spectrographs such as ESPRESSO and CODEX.
The fundamentals of mathematical analysis
Fikhtengol'ts, G M
1965-01-01
The Fundamentals of Mathematical Analysis, Volume 1 is a textbook that provides a systematic and rigorous treatment of the fundamentals of mathematical analysis. Emphasis is placed on the concept of limit which plays a principal role in mathematical analysis. Examples of the application of mathematical analysis to geometry, mechanics, physics, and engineering are given. This volume is comprised of 14 chapters and begins with a discussion on real numbers, their properties and applications, and arithmetical operations over real numbers. The reader is then introduced to the concept of function, i
Fundamental Composite (Goldstone) Higgs Dynamics
DEFF Research Database (Denmark)
Cacciapaglia, G.; Sannino, Francesco
2014-01-01
We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation...... transforming according to the fundamental representation of the gauge group. This minimal choice enables us to use recent first principle lattice results to make the first predictions for the massive spectrum for models of composite (Goldstone) Higgs dynamics. These results are of the upmost relevance to guide...
Accurate determination of antenna directivity
DEFF Research Database (Denmark)
Dich, Mikael
1997-01-01
The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...
Composing Europe's Fundamental Rights Area
DEFF Research Database (Denmark)
Storgaard, Louise Halleskov
2015-01-01
The article offers a perspective on how the objective of a strong and coherent European protection standard pursued by the fundamental rights amendments of the Lisbon Treaty can be achieved, as it proposes a discursive pluralistic framework to understand and guide the relationship between the EU ...
Status of Fundamental Physics Program
Lee, Mark C.
2003-01-01
Update of the Fundamental Physics Program. JEM/EF Slip. 2 years delay. Reduced budget. Community support and advocacy led by Professor Nick Bigelow. Reprogramming led by Fred O Callaghan/JPL team. LTMPF M1 mission (DYNAMX and SUMO). PARCS. Carrier re baselined on JEM/EF.
Different Variants of Fundamental Portfolio
Directory of Open Access Journals (Sweden)
Tarczyński Waldemar
2014-06-01
Full Text Available The paper proposes the fundamental portfolio of securities. This portfolio is an alternative for the classic Markowitz model, which combines fundamental analysis with portfolio analysis. The method’s main idea is based on the use of the TMAI1 synthetic measure and, in limiting conditions, the use of risk and the portfolio’s rate of return in the objective function. Different variants of fundamental portfolio have been considered under an empirical study. The effectiveness of the proposed solutions has been related to the classic portfolio constructed with the help of the Markowitz model and the WIG20 market index’s rate of return. All portfolios were constructed with data on rates of return for 2005. Their effectiveness in 2006- 2013 was then evaluated. The studied period comprises the end of the bull market, the 2007-2009 crisis, the 2010 bull market and the 2011 crisis. This allows for the evaluation of the solutions’ flexibility in various extreme situations. For the construction of the fundamental portfolio’s objective function and the TMAI, the study made use of financial and economic data on selected indicators retrieved from Notoria Serwis for 2005.
Biological Computing Fundamentals and Futures
Akula, Balaji; Cusick, James
2009-01-01
The fields of computing and biology have begun to cross paths in new ways. In this paper a review of the current research in biological computing is presented. Fundamental concepts are introduced and these foundational elements are explored to discuss the possibilities of a new computing paradigm. We assume the reader to possess a basic knowledge of Biology and Computer Science
van Doesum, A.; van Kesteren, H.W.M.; van Norden, G.J.
2016-01-01
Fundamentals of EU VAT Law aims at providing a deep insight into the systematics, the functioning and the principles of the European Value Added Tax (VAT) system. VAT is responsible for generating approximately EUR 903 billion per year in tax revenues across the European Union – revenues that play a
Brake Fundamentals. Automotive Articulation Project.
Cunningham, Larry; And Others
Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…
Calorimetry fundamentals, instrumentation and applications
Sarge, Stefan M; Hemminger, Wolfgang
2014-01-01
Clearly divided into three parts, this practical book begins by dealing with all fundamental aspects of calorimetry. The second part looks at the equipment used and new developments. The third and final section provides measurement guidelines in order to obtain the best results. The result is optimized knowledge for users of this technique, supplemented with practical tips and tricks.
Fundamentals of Microelectronics Processing (VLSI).
Takoudis, Christos G.
1987-01-01
Describes a 15-week course in the fundamentals of microelectronics processing in chemical engineering, which emphasizes the use of very large scale integration (VLSI). Provides a listing of the topics covered in the course outline, along with a sample of some of the final projects done by students. (TW)
Fundamentals of Welding. Teacher Edition.
Fortney, Clarence; And Others
These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…
Fundamentals: IVC and computer science
Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Geert; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.
2013-01-01
The working group on “Fundamentals: IVC and Computer Science” discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly
Analytical Study on Fundamental Frequency Contours of Thai Expressive Speech Using Fujisaki's Model
Directory of Open Access Journals (Sweden)
Suphattharachai Chomphan
2010-01-01
Full Text Available Problem statement: In spontaneous speech communication, prosody is an important factor that must be taken into account, since the prosody effects on not only the naturalness but also the intelligibility of speech. Focusing on synthesis of Thai expressive speech, a number of systems has been developed for years. However, the expressive speech with various speaking styles has not been accomplished. To achieve the generation of expressive speech, we need to model the fundamental frequency (F0 contours accurately to preserve the speech prosody. Approach: Therefore this study proposes an analysis of model parameters for Thai speech prosody with three speaking styles and two genders which is a preliminary work for speech synthesis. Fujisaki's modeling; a powerful tool to model the F0 contour has been adopted, while the speaking styles of happiness, sadness and reading have been considered. Seven derived parameters from the Fujisaki's model are as follows. The first parameter is baseline frequency which is the lowest level of F0 contour. The second and third parameters are the numbers of phrase commands and tone commands which reflect the frequencies of surges of the utterance in global and local levels, respectively. The fourth and fifth parameters are phrase command and tone command durations which reflect the speed of speaking and the length of a syllable, respectively. The sixth and seventh parameters are amplitudes of phrase command and tone command which reflect the energy of the global speech and the energy of local syllable. Results: In the experiments, each speaking style includes 200 samples of one sentence with male and female speech. Therefore our speech database contains 1200 utterances in total. The results show that most of the proposed parameters can distinguish three kinds of speaking styles explicitly. Conclusion: From the finding, it is a strong evidence to further apply the successful parameters in the speech synthesis systems or
Accurate lineshape spectroscopy and the Boltzmann constant.
Truong, G-W; Anstie, J D; May, E F; Stace, T M; Luiten, A N
2015-10-14
Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here, we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a very accurate measurement of the excited-state (6P1/2) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity dispersion of the Cs vapour with an uncertainty of 35 p.p.m. within an hour. This allows us to determine a value for Boltzmann's constant with a precision of 6 p.p.m., and an uncertainty of 71 p.p.m.
Accurate thermoplasmonic simulation of metallic nanoparticles
Yu, Da-Miao; Liu, Yan-Nan; Tian, Fa-Lin; Pan, Xiao-Min; Sheng, Xin-Qing
2017-01-01
Thermoplasmonics leads to enhanced heat generation due to the localized surface plasmon resonances. The measurement of heat generation is fundamentally a complicated task, which necessitates the development of theoretical simulation techniques. In this paper, an efficient and accurate numerical scheme is proposed for applications with complex metallic nanostructures. Light absorption and temperature increase are, respectively, obtained by solving the volume integral equation (VIE) and the steady-state heat diffusion equation through the method of moments (MoM). Previously, methods based on surface integral equations (SIEs) were utilized to obtain light absorption. However, computing light absorption from the equivalent current is as expensive as O(NsNv), where Ns and Nv, respectively, denote the number of surface and volumetric unknowns. Our approach reduces the cost to O(Nv) by using VIE. The accuracy, efficiency and capability of the proposed scheme are validated by multiple simulations. The simulations show that our proposed method is more efficient than the approach based on SIEs under comparable accuracy, especially for the case where many incidents are of interest. The simulations also indicate that the temperature profile can be tuned by several factors, such as the geometry configuration of array, beam direction, and light wavelength.
Reassessing The Fundamentals: New Constraints on the Evolution, Ages and Masses of Neutron Stars
Kiziltan, Bulent
2011-01-01
The ages and masses of neutron stars (NSs) are two fundamental threads that make pulsars accessible to other sub-disciplines of astronomy and physics. A realistic and accurate determination of these two derived parameters play an important role in understanding of advanced stages of stellar evolution and the physics that govern relevant processes. Here I summarize new constraints on the ages and masses of NSs with an evolutionary perspective. I show that the observed P-Pdot demographics is more diverse than what is theoretically predicted for the standard evolutionary channel. In particular, standard recycling followed by dipole spin-down fails to reproduce the population of millisecond pulsars with higher magnetic fields (B > 4 x 10^{8} G) at rates deduced from observations. A proper inclusion of constraints arising from binary evolution and mass accretion offers a more realistic insight into the age distribution. By analytically implementing these constraints, I propose a "modified" spin-down age for millis...
Wang, Liqiang; Liu, Zhen; Zhang, Zhonghua
2014-11-01
Stereo vision is the key in the visual measurement, robot vision, and autonomous navigation. Before performing the system of stereo vision, it needs to calibrate the intrinsic parameters for each camera and the external parameters of the system. In engineering, the intrinsic parameters remain unchanged after calibrating cameras, and the positional relationship between the cameras could be changed because of vibration, knocks and pressures in the vicinity of the railway or motor workshops. Especially for large baselines, even minute changes in translation or rotation can affect the epipolar geometry and scene triangulation to such a degree that visual system becomes disabled. A technology including both real-time examination and on-line recalibration for the external parameters of stereo system becomes particularly important. This paper presents an on-line method for checking and recalibrating the positional relationship between stereo cameras. In epipolar geometry, the external parameters of cameras can be obtained by factorization of the fundamental matrix. Thus, it offers a method to calculate the external camera parameters without any special targets. If the intrinsic camera parameters are known, the external parameters of system can be calculated via a number of random matched points. The process is: (i) estimating the fundamental matrix via the feature point correspondences; (ii) computing the essential matrix from the fundamental matrix; (iii) obtaining the external parameters by decomposition of the essential matrix. In the step of computing the fundamental matrix, the traditional methods are sensitive to noise and cannot ensure the estimation accuracy. We consider the feature distribution situation in the actual scene images and introduce a regional weighted normalization algorithm to improve accuracy of the fundamental matrix estimation. In contrast to traditional algorithms, experiments on simulated data prove that the method improves estimation
Constraining the fundamental interactions and couplings with Eoetvoes experiments
Energy Technology Data Exchange (ETDEWEB)
Kraiselburd, Lucila, E-mail: lkrai@fcaglp.fcaglp.unlp.edu.ar [Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900) La Plata (Argentina); Vucetich, Hector, E-mail: vucetich@fcaglp.unlp.edu.ar [Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900) La Plata (Argentina)
2012-11-15
Upper bounds for the violation of the Weak Equivalence Principle (WEP) by the fundamental interactions have been given before. We now recompute the limits on the parameters measuring the strength of the violation with the whole set of high accuracy Eoetvoes experiments. Besides, limits on spatial variation of the fundamental constants {alpha}, sin{sup 2}{theta}{sub W} and v, the vacuum expectation value of the Higgs field, are found in a model independent way. Limits on other parameters in the gauge sector are also found from the structure of the Standard Model.
Toward Accurate and Quantitative Comparative Metagenomics
Nayfach, Stephen; Pollard, Katherine S.
2016-01-01
Shotgun metagenomics and computational analysis are used to compare the taxonomic and functional profiles of microbial communities. Leveraging this approach to understand roles of microbes in human biology and other environments requires quantitative data summaries whose values are comparable across samples and studies. Comparability is currently hampered by the use of abundance statistics that do not estimate a meaningful parameter of the microbial community and biases introduced by experimental protocols and data-cleaning approaches. Addressing these challenges, along with improving study design, data access, metadata standardization, and analysis tools, will enable accurate comparative metagenomics. We envision a future in which microbiome studies are replicable and new metagenomes are easily and rapidly integrated with existing data. Only then can the potential of metagenomics for predictive ecological modeling, well-powered association studies, and effective microbiome medicine be fully realized. PMID:27565341
How Accurately can we Calculate Thermal Systems?
Energy Technology Data Exchange (ETDEWEB)
Cullen, D; Blomquist, R N; Dean, C; Heinrichs, D; Kalugin, M A; Lee, M; Lee, Y; MacFarlan, R; Nagaya, Y; Trkov, A
2004-04-20
I would like to determine how accurately a variety of neutron transport code packages (code and cross section libraries) can calculate simple integral parameters, such as K{sub eff}, for systems that are sensitive to thermal neutron scattering. Since we will only consider theoretical systems, we cannot really determine absolute accuracy compared to any real system. Therefore rather than accuracy, it would be more precise to say that I would like to determine the spread in answers that we obtain from a variety of code packages. This spread should serve as an excellent indicator of how accurately we can really model and calculate such systems today. Hopefully, eventually this will lead to improvements in both our codes and the thermal scattering models that they use in the future. In order to accomplish this I propose a number of extremely simple systems that involve thermal neutron scattering that can be easily modeled and calculated by a variety of neutron transport codes. These are theoretical systems designed to emphasize the effects of thermal scattering, since that is what we are interested in studying. I have attempted to keep these systems very simple, and yet at the same time they include most, if not all, of the important thermal scattering effects encountered in a large, water-moderated, uranium fueled thermal system, i.e., our typical thermal reactors.
Accurate Modeling of Advanced Reflectarrays
DEFF Research Database (Denmark)
Zhou, Min
Analysis and optimization methods for the design of advanced printed re ectarrays have been investigated, and the study is focused on developing an accurate and efficient simulation tool. For the analysis, a good compromise between accuracy and efficiency can be obtained using the spectral domain...... to the POT. The GDOT can optimize for the size as well as the orientation and position of arbitrarily shaped array elements. Both co- and cross-polar radiation can be optimized for multiple frequencies, dual polarization, and several feed illuminations. Several contoured beam reflectarrays have been designed...... using the GDOT to demonstrate its capabilities. To verify the accuracy of the GDOT, two offset contoured beam reflectarrays that radiate a high-gain beam on a European coverage have been designed and manufactured, and subsequently measured at the DTU-ESA Spherical Near-Field Antenna Test Facility...
The Accurate Particle Tracer Code
Wang, Yulei; Qin, Hong; Yu, Zhi
2016-01-01
The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and non-linear problems. Under the well-designed integrated and modularized framework, APT serves as a universal platform for researchers from different fields, such as plasma physics, accelerator physics, space science, fusion energy research, computational mathematics, software engineering, and high-performance computation. The APT code consists of seven main modules, including the I/O module, the initialization module, the particle pusher module, the parallelization module, the field configuration module, the external force-field module, and the extendible module. The I/O module, supported by Lua and Hdf5 projects, provides a user-friendly interface for both numerical simulation and data analysis. A series of new geometric numerical methods...
Accurate ab initio spin densities
Boguslawski, Katharina; Legeza, Örs; Reiher, Markus
2012-01-01
We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys. 2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CA...
Accurate thickness measurement of graphene.
Shearer, Cameron J; Slattery, Ashley D; Stapleton, Andrew J; Shapter, Joseph G; Gibson, Christopher T
2016-03-29
Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.
Accurate thickness measurement of graphene
Shearer, Cameron J.; Slattery, Ashley D.; Stapleton, Andrew J.; Shapter, Joseph G.; Gibson, Christopher T.
2016-03-01
Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.
Supersymmetry Parameter Analysis
Kalinowski, Jan
2002-01-01
Supersymmetric particles can be produced copiously at future colliders. From the high-precision data taken at e+e- linear colliders, TESLA in particular, and combined with results from LHC, and CLIC later, the low-energy parameters of the supersymmetric model can be determined. Evolving the parameters from the low-energy scale to the high-scale by means of renormalization group techniques the fundamental supersymmetry parameters at the high scale, GUT or Planck, can be reconstructed to reveal the origin of supersymmetry breaking.
Constraints on Cosmological Parameters: Combining Planck With Other Measurements
Freedman, Wendy
2015-08-01
The recent measurements from Planck have set a new high bar for accuracy in the measurement of cosmological parameters. In parallel, new and increasingly accurate measurements of Baryon Acoustic Oscillations, Type Ia supernovae, and the Hubble Constant offer independent probes of various cosmological parameters. The increased accuracy in cosmic microwave background fluctuation measurements make direct comparisons with other methods even more critical, given the intrinsic physical degeneracies amongst different cosmological parameters in the acoustic oscillation spectrum. There has been fundamental progress over the last couple of decades in measuring extragalactic distances. I will discuss the current limits, and the prospects for reaching 1% uncertainty in measurement of the Hubble constant, which, combined with measurements from Planck, will be critical for providing independent constraints on dark energy, the geometry, and matter density of the universe.
Fundamentals of estuarine physical oceanography
Bruner de Miranda, Luiz; Kjerfve, Björn; Castro Filho, Belmiro Mendes de
2017-01-01
This book provides an introduction to the complex system functions, variability and human interference in ecosystem between the continent and the ocean. It focuses on circulation, transport and mixing of estuarine and coastal water masses, which is ultimately related to an understanding of the hydrographic and hydrodynamic characteristics (salinity, temperature, density and circulation), mixing processes (advection and diffusion), transport timescales such as the residence time and the exposure time. In the area of physical oceanography, experiments using these water bodies as a natural laboratory and interpreting their circulation and mixing processes using theoretical and semi-theoretical knowledge are of fundamental importance. Small-scale physical models may also be used together with analytical and numerical models. The book highlights the fact that research and theory are interactive, and the results provide the fundamentals for the development of the estuarine research.
Fundamental investigations of catalyst nanoparticles
DEFF Research Database (Denmark)
Elkjær, Christian Fink
area Cu=ZnO=Al2O3 structure that is difficult to study by TEM. We therefore created size-selected CuZn alloy nanoparticles that were transformed by oxidation and reduction into Cu nanoparticles decorated with ZnO. This represents a simplified model system for the high surface area catalyst...... been unknown. We used nanoreactor technology which allows for simultaneous TEM imaging and activity measurement, also referred to as an Operando experiment. With this we revealed that the shape of the Pt nanoparticles changed in phase with changes in global reaction rate. By the use of reactor modeling...... fundamental understanding of catalytic processes and our ability to make use of that understanding. This thesis presents fundamental studies of catalyst nanoparticles with particular focus on dynamic processes. Such studies often require atomic-scale characterization, because the catalytic conversion takes...
Unified Theory of Fundamental Interactions
Institute of Scientific and Technical Information of China (English)
WU Ning
2003-01-01
Based on local gauge invariance, four different kinds of fundamental interactions in nature are unified in a theory which has SU(3)C( )SU SU(2)L( )U(1)( )s Gravitational Gauge Group gauge symmetry. In this approach,gravitational field, like electromagnetic field, intermediate gauge field, and gluon field, is represented by gauge potential.Four kinds of fundamental interactions are formulated in the similar manner, and therefore can be unified in a direct or semi-direct product group. The model discussed in this paper is a renormalizable quantum model and can be regarded as an extension of the standard model to gravitational interactions, so it can be used to study quantum effects of gravitational interactions.
Astrophysical Probes of Fundamental Physics
Martins, C J A P
2006-01-01
I review the theoretical motivation for varying fundamental couplings and discuss how these measurements can be used to constrain a number of fundamental physics scenarios that would otherwise be inacessible to experiment. As a case study I will focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements can be used to probe the nature of dark energy, with important advantages over the standard methods. Assuming that the current observational evidence for varying $\\alpha$ and $\\mu$ is correct, a several-sigma detection of dynamical dark energy is feasible within a few years, using currently operational ground-based facilities. With forthcoming instruments like CODEX, a high-accuracy reconstruction of the equation of state may be possible all the way up to redshift $z\\sim4$.
Fundamentals of condensed matter physics
Cohen, Marvin L
2016-01-01
Based on an established course and covering the fundamentals, central areas, and contemporary topics of this diverse field, Fundamentals of Condensed Matter Physics is a much-needed textbook for graduate students. The book begins with an introduction to the modern conceptual models of a solid from the points of view of interacting atoms and elementary excitations. It then provides students with a thorough grounding in electronic structure as a starting point to understand many properties of condensed matter systems - electronic, structural, vibrational, thermal, optical, transport, magnetic and superconductivity - and methods to calculate them. Taking readers through the concepts and techniques, the text gives both theoretically and experimentally inclined students the knowledge needed for research and teaching careers in this field. It features 200 illustrations, 40 worked examples and 150 homework problems for students to test their understanding. Solutions to the problems for instructors are available at w...
Fundamental neutron physics at LANSCE
Energy Technology Data Exchange (ETDEWEB)
Greene, G.
1995-10-01
Modern neutron sources and science share a common origin in mid-20th-century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for studying condensed matter with modern neutron sources being primarily used (and justified) as tools for neutron scattering and materials science research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities performed at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high-flux neutron facilities. Future sources, particularly high-power spallation sources, offer exciting possibilities for continuing this research.
THE FUNDAMENTS OF EXPLANATORY CAUSES
Directory of Open Access Journals (Sweden)
Lavinia Mihaela VLĂDILĂ
2015-07-01
Full Text Available The new Criminal Code in the specter of the legal life the division of causes removing the criminal feature of the offence in explanatory causes and non-attributable causes. This dichotomy is not without legal and factual fundaments and has been subjected to doctrinaire debates even since the period when the Criminal Code of 1969 was still in force. From our perspective, one of the possible legal fundaments of the explanatory causes results from that the offence committed is based on the protection of a right at least equal with the one prejudiced by the action of aggression, salvation, by the legal obligation imposed or by the victim’s consent.
Modern measurements fundamentals and applications
Petri, D; Carbone, P; Catelani, M
2015-01-01
This book explores the modern role of measurement science for both the technically most advanced applications and in everyday and will help readers gain the necessary skills to specialize their knowledge for a specific field in measurement. Modern Measurements is divided into two parts. Part I (Fundamentals) presents a model of the modern measurement activity and the already recalled fundamental bricks. It starts with a general description that introduces these bricks and the uncertainty concept. The next chapters provide an overview of these bricks and ﬁnishes (Chapter 7) with a more general and complex model that encompasses both traditional (hard) measurements and (soft) measurements, aimed at quantifying non-physical concepts, such as quality, satisfaction, comfort, etc. Part II (Applications) is aimed at showing how the concepts presented in Part I can be usefully applied to design and implement measurements in some very impor ant and broad ﬁelds. The editors cover System Identiﬁcation (Chapter 8...
Fundamental Scaling Laws in Nanophotonics
Ke Liu; Shuai Sun; Arka Majumdar; Volker J. Sorger
2016-01-01
The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of “smaller-is-better” has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoe...
Fundamentals of plastic optical fibers
Koike, Yasuhiro
2014-01-01
Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,
Violation of fundamental symmetries and variation of fundamental constants in atomic phenomena
Flambaum, V. V.
2007-06-01
We present a review of recent works on variation of fundamental constants and violation of parity in atoms and nuclei. Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We describe recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses (Higgs vacuum). There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transitions between very close atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on UV transition in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Measurements of violation of fundamental symmetries, parity (P) and time reversal (T), in atoms allows one to test unification theories in atomic experiments. We have developed an accurate method of many-body calculations - all-orders summation of dominating diagrams in residual e-e interaction. To calculate QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atoms and molecules we derived the ``radiative potential'' and the low-energy theorem. This method is simple and can be easily incorporated into any many-body theory approach. Using the radiative correction and many-body calculations we obtained the PNC amplitude EPNC = -0.898(1 +/- 0.5%) × 10-11ieaB(-QW/N). From the measurements of the PNC amplitude we extracted the Cs weak charge QW = -72.66(29)exp(36)theor. The
Online Dynamic Parameter Estimation of Synchronous Machines
West, Michael R.
Traditionally, synchronous machine parameters are determined through an offline characterization procedure. The IEEE 115 standard suggests a variety of mechanical and electrical tests to capture the fundamental characteristics and behaviors of a given machine. These characteristics and behaviors can be used to develop and understand machine models that accurately reflect the machine's performance. To perform such tests, the machine is required to be removed from service. Characterizing a machine offline can result in economic losses due to down time, labor expenses, etc. Such losses may be mitigated by implementing online characterization procedures. Historically, different approaches have been taken to develop methods of calculating a machine's electrical characteristics, without removing the machine from service. Using a machine's input and response data combined with a numerical algorithm, a machine's characteristics can be determined. This thesis explores such characterization methods and strives to compare the IEEE 115 standard for offline characterization with the least squares approximation iterative approach implemented on a 20 h.p. synchronous machine. This least squares estimation method of online parameter estimation shows encouraging results for steady-state parameters, in comparison with steady-state parameters obtained through the IEEE 115 standard.
Directory of Open Access Journals (Sweden)
Elaine Gomes Fiore
2012-12-01
Full Text Available A Segurança Alimentar e Nutricional (SAN deve ser assegurada a todos. A escola é ambiente propício à formação de hábitos saudáveis e à construção de cidadania. Os Parâmetros Curriculares Nacionais (PCNs orientam a promoção de concepções de saúde de modo transversal no currículo escolar. Este estudo teve como objetivo identificar e analisar a abordagem dos temas alimentação e nutrição no material didático do ensino fundamental e sua interface com o conceito de SAN e com os PCNs. Foi realizada pesquisa documental mediante o material didático de 5ª a 8ª séries do ensino fundamental da rede pública do Estado de São Paulo. A presença difusa do tema alimentação e nutrição na maioria das disciplinas, por todos os bimestres, nas quatro séries, traz à tona a interdisciplinaridade em saúde. Verificou-se que os PCNs estão relacionados ao conceito de SAN nos seus diversos aspectos e que a maioria das disciplinas contém temas que abordam esta relação. Na interface entre os temas, destaca-se a promoção da saúde e a produção dos alimentos. A metodologia utilizada no material didático apresenta o tema, mas não o conteúdo correlato, o que impossibilitou a análise de sua adequação. Conclui-se que existe a abordagem dos temas relacionados à alimentação e nutrição no material didático, alguns de forma inconsistente, e cabe aos educadores a seleção do conteúdo e da estratégia adequada, além de sua constante atualização, o que está sendo proposto pelo Estado, mas não está ao alcance de todos os profissionais e, portanto, ainda depende da iniciativa de cada docente.Food and Nutrition Security (FNS must be ensured to everybody. The school environment is favorable to the formation of healthy habits and citizenship. The National Curriculum Parameters (PCNs guide the promotion of health concepts in a transversal way in the school curriculum. This study aimed to identify and analyze the approach used for
Accurate computation of Mathieu functions
Bibby, Malcolm M
2013-01-01
This lecture presents a modern approach for the computation of Mathieu functions. These functions find application in boundary value analysis such as electromagnetic scattering from elliptic cylinders and flat strips, as well as the analogous acoustic and optical problems, and many other applications in science and engineering. The authors review the traditional approach used for these functions, show its limitations, and provide an alternative ""tuned"" approach enabling improved accuracy and convergence. The performance of this approach is investigated for a wide range of parameters and mach
A More Accurate Fourier Transform
Courtney, Elya
2015-01-01
Fourier transform methods are used to analyze functions and data sets to provide frequencies, amplitudes, and phases of underlying oscillatory components. Fast Fourier transform (FFT) methods offer speed advantages over evaluation of explicit integrals (EI) that define Fourier transforms. This paper compares frequency, amplitude, and phase accuracy of the two methods for well resolved peaks over a wide array of data sets including cosine series with and without random noise and a variety of physical data sets, including atmospheric $\\mathrm{CO_2}$ concentrations, tides, temperatures, sound waveforms, and atomic spectra. The FFT uses MIT's FFTW3 library. The EI method uses the rectangle method to compute the areas under the curve via complex math. Results support the hypothesis that EI methods are more accurate than FFT methods. Errors range from 5 to 10 times higher when determining peak frequency by FFT, 1.4 to 60 times higher for peak amplitude, and 6 to 10 times higher for phase under a peak. The ability t...
Optimization of sample preparation for accurate results in quantitative NMR spectroscopy
Yamazaki, Taichi; Nakamura, Satoe; Saito, Takeshi
2017-04-01
Quantitative nuclear magnetic resonance (qNMR) spectroscopy has received high marks as an excellent measurement tool that does not require the same reference standard as the analyte. Measurement parameters have been discussed in detail and high-resolution balances have been used for sample preparation. However, the high-resolution balances, such as an ultra-microbalance, are not general-purpose analytical tools and many analysts may find those balances difficult to use, thereby hindering accurate sample preparation for qNMR measurement. In this study, we examined the relationship between the resolution of the balance and the amount of sample weighed during sample preparation. We were able to confirm the accuracy of the assay results for samples weighed on a high-resolution balance, such as the ultra-microbalance. Furthermore, when an appropriate tare and amount of sample was weighed on a given balance, accurate assay results were obtained with another high-resolution balance. Although this is a fundamental result, it offers important evidence that would enhance the versatility of the qNMR method.
Optimal strategies for throwing accurately
Venkadesan, Madhusudhan
2010-01-01
Accuracy of throwing in games and sports is governed by how errors at projectile release are propagated by flight dynamics. To address the question of what governs the choice of throwing strategy, we use a simple model of throwing with an arm modelled as a hinged bar of fixed length that can release a projectile at any angle and angular velocity. We show that the amplification of deviations in launch parameters from a one parameter family of solution curves is quantified by the largest singular value of an appropriate Jacobian. This allows us to predict a preferred throwing style in terms of this singular value, which itself depends on target location and the target shape. Our analysis also allows us to characterize the trade-off between speed and accuracy despite not including any effects of signal-dependent noise. Using nonlinear calculations for propagating finite input-noise, we find that an underarm throw to a target leads to an undershoot, but an overarm throw does not. Finally, we consider the limit of...
Numerical simulation of fundamental trapped sausage modes
Cécere, M; Reula, O
2011-01-01
Context: We integrate the 2D MHD ideal equations of a straight slab to simulate observational results associated with fundamental sausage trapped modes. Aims: Starting from a non-equilibrium state with a dense chromospheric layer, we analyse the evolution of the internal plasma dynamics of magnetic loops, subject to line-tying boundary conditions, and with the coronal parameters described in Asai et al. (2001) and Melnikov et al. (2002) to investigate the onset and damping of sausage modes. Methods: To integrate the equations we used a high resolution shock-capturing (HRSC) method specially designed to deal appropriately with flow discontinuities. Results: Due to non-linearities and inhomogeneities, pure modes are difficult to sustain and always occur coupled among them so as to satisfy, e.g., the line-tying constraint. We found that, in one case, the resonant coupling of the sausage fundamental mode with a slow one results in a non-dissipative damping of the former. Conclusions: In scenarios of thick and den...
Estimating Cosmological Parameter Covariance
Taylor, Andy
2014-01-01
We investigate the bias and error in estimates of the cosmological parameter covariance matrix, due to sampling or modelling the data covariance matrix, for likelihood width and peak scatter estimators. We show that these estimators do not coincide unless the data covariance is exactly known. For sampled data covariances, with Gaussian distributed data and parameters, the parameter covariance matrix estimated from the width of the likelihood has a Wishart distribution, from which we derive the mean and covariance. This mean is biased and we propose an unbiased estimator of the parameter covariance matrix. Comparing our analytic results to a numerical Wishart sampler of the data covariance matrix we find excellent agreement. An accurate ansatz for the mean parameter covariance for the peak scatter estimator is found, and we fit its covariance to our numerical analysis. The mean is again biased and we propose an unbiased estimator for the peak parameter covariance. For sampled data covariances the width estimat...
Structures in the fundamental plane of early-type galaxies
Fraix-Burnet, Didier; Chattopadhyay, Tanuka; Chattopadhyay, Asis Kumar; Davoust, Emmanuel
2010-01-01
The fundamental plane of early-type galaxies is a rather tight three-parameter correlation discovered more than twenty years ago. It has resisted a both global and precise physical interpretation despite a consequent number of works, observational, theoretical or using numerical simulations. It appears that its precise properties depend on the population of galaxies in study. Instead of selecting a priori these populations, we propose to objectively construct homologous populations from multivariate analyses. We have undertaken multivariate cluster and cladistic analyses of a sample of 56 low-redshift galaxy clusters containing 699 early-type galaxies, using four parameters: effective radius, velocity dispersion, surface brightness averaged over effective radius, and Mg2 index. All our analyses are consistent with seven groups that define separate regions on the global fundamental plane, not across its thickness. In fact, each group shows its own fundamental plane, which is more loosely defined for less diver...
Fundamental plane: dark matter and dissipation contributions
Ribeiro, Andre L B
2010-01-01
Stellar and galactic systems are objects in dynamical equilibrium that are composed of ordinary baryonic matter hypothetically embedded in extended dominant dark matter halos. Our aim is to investigate the scaling relations and dissipational features of these objects over a wide range of their properties, taking the dynamical influence of the dark matter component into account. We study the physical properties of these self-gravitating systems using the two-component virial theorem in conjunction with data that embrace a wide range of astrophysical systems. We find that the scaling relations defined by the properties of these objects admit a dark-to-luminous density ratio parameter as a natural requirement in this framework. We also probe dissipational effects on the fundamental surface defined by the two-component virial theorem and discuss their relations with respect to the region devoid of objects in the data distribution. Our results indicate complementary contributions of dissipation and dark matter to ...
Fundamentals of aircraft and rocket propulsion
El-Sayed, Ahmed F
2016-01-01
This book provides a comprehensive basics-to-advanced course in an aero-thermal science vital to the design of engines for either type of craft. The text classifies engines powering aircraft and single/multi-stage rockets, and derives performance parameters for both from basic aerodynamics and thermodynamics laws. Each type of engine is analyzed for optimum performance goals, and mission-appropriate engines selection is explained. Fundamentals of Aircraft and Rocket Propulsion provides information about and analyses of: thermodynamic cycles of shaft engines (piston, turboprop, turboshaft and propfan); jet engines (pulsejet, pulse detonation engine, ramjet, scramjet, turbojet and turbofan); chemical and non-chemical rocket engines; conceptual design of modular rocket engines (combustor, nozzle and turbopumps); and conceptual design of different modules of aero-engines in their design and off-design state. Aimed at graduate and final-year undergraduate students, this textbook provides a thorough grounding in th...
Fundamentals of semiconductors physics and materials properties
Yu, Peter Y
1996-01-01
Fundamentals of Semiconductors attempts to fill the gap between a general solid-state physics textbook and research articles by providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors The approach is physical and intuitive rather than formal and pedantic Theories are presented to explain experimental results This textbook has been written with both students and researchers in mind Its emphasis is on understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors The explanations are based on physical insights Each chapter is enriched by an extensive collection of tables of material parameters, figures and problems Many of these problems 'lead the student by the hand' to arrive at the results
Fundamentals of semiconductors physics and materials properties
Yu, Peter Y
2010-01-01
This fourth edition of the well-established Fundamentals of Semiconductors serves to fill the gap between a general solid-state physics textbook and research articles by providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. The approach is physical and intuitive rather than formal and pedantic. Theories are presented to explain experimental results. This textbook has been written with both students and researchers in mind. Its emphasis is on understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors. The explanations are based on physical insights. Each chapter is enriched by an extensive collection of tables of material parameters, figures, and problems. Many of these problems "lead the student by the hand" to arrive at the results. The major changes made in the fourth edition include: an extensive appendix about the important and by now well-established deep center known as the DX center, additional problems...
Fundamental Limits to Cellular Sensing
ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew
2016-03-01
In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade
Fundamental cycles and graph embeddings
Institute of Scientific and Technical Information of China (English)
2009-01-01
In this paper, we investigate fundamental cycles in a graph G and their relations with graph embeddings. We show that a graph G may be embedded in an orientable surface with genus at least g if and only if for any spanning tree T , there exists a sequence of fundamental cycles C1, C2, . . . , C2g with C2i-1 ∩ C2i≠ф for 1≤ i ≤g. In particular, among β(G) fundamental cycles of any spanning tree T of a graph G, there are exactly 2γM (G) cycles C1, C2, . . . , C2γM (G) such that C2i-1 ∩ C2i≠ф for 1 ≤i≤γM (G), where β(G) and γM (G) are the Betti number and the maximum genus of G, respectively. This implies that it is possible to construct an orientable embedding with large genus of a graph G from an arbitrary spanning tree T (which may have very large number of odd components in G\\E(T )). This is different from the earlier work of Xuong and Liu, where spanning trees with small odd components are needed. In fact, this makes a common generalization of Xuong, Liu and Fu et al. Furthermore, we show that (1) this result is useful for locating the maximum genus of a graph having a specific edge-cut. Some known results for embedded graphs are also concluded; (2) the maximum genus problem may be reduced to the maximum matching problem. Based on this result and the algorithm of Micali-Vazirani, we present a new efficient algorithm to determine the maximum genus of a graph in O((β(G)) 25 ) steps. Our method is straight and quite different from the algorithm of Furst, Gross and McGeoch which depends on a result of Giles where matroid parity method is needed.
Accurate and Simple Calibration of DLP Projector Systems
DEFF Research Database (Denmark)
Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus
2014-01-01
Much work has been devoted to the calibration of optical cameras, and accurate and simple methods are now available which require only a small number of calibration targets. The problem of obtaining these parameters for light projectors has not been studied as extensively and most current methods...
Fundamentals of gas particle flow
Rudinger, G
1980-01-01
Fundamentals of Gas-Particle Flow is an edited, updated, and expanded version of a number of lectures presented on the "Gas-Solid Suspensions course organized by the von Karman Institute for Fluid Dynamics. Materials presented in this book are mostly analytical in nature, but some experimental techniques are included. The book focuses on relaxation processes, including the viscous drag of single particles, drag in gas-particles flow, gas-particle heat transfer, equilibrium, and frozen flow. It also discusses the dynamics of single particles, such as particles in an arbitrary flow, in a r
Fundamentals of magnetism and electricity
Arya, SN
2009-01-01
Fundamentals of Magnetism and Electricity is a textbook on the physics of electricity, magnetism, and electromagnetic fields and waves. It is written mainly with the physics student in mind, although it will also be of use to students of electrical and electronic engineering. The approach is concise but clear, and the author has assumed that the reader will be familiar with the basic phenomena. The theory, however, is set out in a completely self-contained and coherent way and developed to the point where the reader can appreciate the beauty and coherence of the Maxwell equations.
Electronic imaging fundamentals: basic theory.
Vizy, K N
1983-01-01
Introduction of the computer into the field of medical imaging, as typified by the extensive use of digital subtraction angiography (DSA), created an important need for a basic understanding of the principles of digital imaging. This paper reviews these fundamental principles, starting with the definition of images and the interaction of these images with television display systems, then continuing with a detailed description of the way in which imaging systems are specified. This work defines the basic terms and concepts that will be used throughout the contents of this issue.
Quantum Uncertainty and Fundamental Interactions
Directory of Open Access Journals (Sweden)
Tosto S.
2013-04-01
Full Text Available The paper proposes a simplified theoretical approach to infer some essential concepts on the fundamental interactions between charged particles and their relative strengths at comparable energies by exploiting the quantum uncertainty only. The worth of the present approach relies on the way of obtaining the results, rather than on the results themselves: concepts today acknowledged as fingerprints of the electroweak and strong interactions appear indeed rooted in the same theoretical frame including also the basic principles of special and general relativity along with the gravity force.
Fundamental Laser Welding Process Investigations
DEFF Research Database (Denmark)
Bagger, Claus; Olsen, Flemming Ove
1998-01-01
In a number of systematic laboratory investigations the fundamental behavior of the laser welding process was analyzed by the use of normal video (30 Hz), high speed video (100 and 400 Hz) and photo diodes. Sensors were positioned to monitor the welding process from both the top side and the rear...... side of the specimen.Special attention has been given to the dynamic nature of the laser welding process, especially during unstable welding conditions. In one series of experiments, the stability of the process has been varied by changing the gap distance in lap welding. In another series...
Communication technology update and fundamentals
Grant, August E
2014-01-01
A classic now in its 14th edition, Communication Technology Update and Fundamentals is the single best resource for students and professionals looking to brush up on how these technologies have developed, grown, and converged, as well as what's in store for the future. It begins by developing the communication technology framework-the history, ecosystem, and structure-then delves into each type of technology, including everything from mass media, to computers and consumer electronics, to networking technologies. Each chapter is written by faculty and industry experts who p
Foam engineering fundamentals and applications
2012-01-01
Containing contributions from leading academic and industrial researchers, this book provides a much needed update of foam science research. The first section of the book presents an accessible summary of the theory and fundamentals of foams. This includes chapters on morphology, drainage, Ostwald ripening, coalescence, rheology, and pneumatic foams. The second section demonstrates how this theory is used in a wide range of industrial applications, including foam fractionation, froth flotation and foam mitigation. It includes chapters on suprafroths, flotation of oil sands, foams in enhancing petroleum recovery, Gas-liquid Mass Transfer in foam, foams in glass manufacturing, fire-fighting foam technology and consumer product foams.
Computing fundamentals digital literacy edition
Wempen, Faithe
2014-01-01
Computing Fundamentals has been tailor made to help you get up to speed on your Computing Basics and help you get proficient in entry level computing skills. Covering all the key topics, it starts at the beginning and takes you through basic set-up so that you'll be competent on a computer in no time.You'll cover: Computer Basics & HardwareSoftwareIntroduction to Windows 7Microsoft OfficeWord processing with Microsoft Word 2010Creating Spreadsheets with Microsoft ExcelCreating Presentation Graphics with PowerPointConnectivity and CommunicationWeb BasicsNetwork and Internet Privacy and Securit
Fundamentals of spread spectrum modulation
Ziemer, Rodger E
2007-01-01
This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spect
Fundamentals of soft matter science
Hirst, Linda S
2012-01-01
""The publication is written at a very fundamental level, which will make it easily readable for undergraduate students. It will certainly also be a valuable text for students and postgraduates in interdisciplinary programmes, as not only physical aspects, but also the chemistry and applications are presented and discussed. … The book is well illustrated, and I really do like the examples and pictures provided for simple demonstration experiments, which can be done during the lectures. Also, the experimental techniques chapter at the end of the book may be helpful. The question sections are he
Computing fundamentals introduction to computers
Wempen, Faithe
2014-01-01
The absolute beginner's guide to learning basic computer skills Computing Fundamentals, Introduction to Computers gets you up to speed on basic computing skills, showing you everything you need to know to conquer entry-level computing courses. Written by a Microsoft Office Master Instructor, this useful guide walks you step-by-step through the most important concepts and skills you need to be proficient on the computer, using nontechnical, easy-to-understand language. You'll start at the very beginning, getting acquainted with the actual, physical machine, then progress through the most common
Fundamentals of ultrasonic phased arrays
Schmerr, Lester W
2014-01-01
This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and
Solid Lubrication Fundamentals and Applications
Miyoshi, Kazuhisa
2001-01-01
Solid Lubrication Fundamentals and Applications description of the adhesion, friction, abrasion, and wear behavior of solid film lubricants and related tribological materials, including diamond and diamond-like solid films. The book details the properties of solid surfaces, clean surfaces, and contaminated surfaces as well as discussing the structures and mechanical properties of natural and synthetic diamonds; chemical-vapor-deposited diamond film; surface design and engineering toward wear-resistant, self-lubricating diamond films and coatings. The author provides selection and design criteria as well as applications for synthetic and natural coatings in the commercial, industrial and aerospace industries..
Photovoltaics fundamentals, technology and practice
Mertens, Konrad
2013-01-01
Concise introduction to the basic principles of solar energy, photovoltaic systems, photovoltaic cells, photovoltaic measurement techniques, and grid connected systems, overviewing the potential of photovoltaic electricity for students and engineers new to the topic After a brief introduction to the topic of photovoltaics' history and the most important facts, Chapter 1 presents the subject of radiation, covering properties of solar radiation, radiation offer, and world energy consumption. Chapter 2 looks at the fundamentals of semiconductor physics. It discusses the build-up of semiconducto
Fundamental Limits of Ultrathin Metasurfaces
Arbabi, Amir
2014-01-01
We present universal theoretical limits on the operation and performance of non-magnetic passive ultrathin metasurfaces. In particular, we prove that their local transmission, reflection, and polarization conversion coefficients are confined to limited regions of the complex plane. As a result, full control over the phase of the light transmitted through such metasurfaces cannot be achieved if the polarization of the light is not to be affected at the same time. We also establish fundamental limits on the maximum polarization conversion efficiency of these metasurfaces, and show that they cannot achieve more than 25% polarization conversion efficiency in transmission.
Fundamentals of liquid crystal devices
Yang, Deng-Ke
2014-01-01
Revised throughout to cover the latest developments in the fast moving area of display technology, this 2nd edition of Fundamentals of Liquid Crystal Devices, will continue to be a valuable resource for those wishing to understand the operation of liquid crystal displays. Significant updates include new material on display components, 3D LCDs and blue-phase displays which is one of the most promising new technologies within the field of displays and it is expected that this new LC-technology will reduce the response time and the number of optical components of LC-modules. Prof. Yang is a pion
Autodesk Combustion 4 fundamentals courseware
Autodesk,
2005-01-01
Whether this is your first experience with Combustion software or you're upgrading to take advantage of the many new features and tools, this guide will serve as your ultimate resource to this all-in-one professional compositing application. Much more than a point-and-click manual, this guide explains the principles behind the software, serving as an overview of the package and associated techniques. Written by certified Autodesk training specialists for motion graphic designers, animators, and visual effects artists, Combustion 4 Fundamentals Courseware provides expert advice for all skill le
Elementary results for the fundamental representation of SU(3)
Curtright, Thomas L
2015-01-01
A general group element for the fundamental representation of SU(3) is expressed as a second order polynomial in the hermitian generating matrix H, with coefficients consisting of elementary trigonometric functions dependent on the sole invariant det(H), in addition to the group parameter $theta$.
Accurate Parallel Algorithm for Adini Nonconforming Finite Element
Institute of Scientific and Technical Information of China (English)
罗平; 周爱辉
2003-01-01
Multi-parameter asymptotic expansions are interesting since they justify the use of multi-parameter extrapolation which can be implemented in parallel and are well studied in many papers for the conforming finite element methods. For the nonconforming finite element methods, however, the work of the multi-parameter asymptotic expansions and extrapolation have seldom been found in the literature. This paper considers the solution of the biharmonic equation using Adini nonconforming finite elements and reports new results for the multi-parameter asymptotic expansions and extrapolation. The Adini nonconforming finite element solution of the biharmonic equation is shown to have a multi-parameter asymptotic error expansion and extrapolation. This expansion and a multi-parameter extrapolation technique were used to develop an accurate approximation parallel algorithm for the biharmonic equation. Finally, numerical results have verified the extrapolation theory.
The Fundamental Manifold of Spheroids
Zaritsky, D; Zabludoff, A I; Zaritsky, Dennis; Gonzalez, Anthony H.; Zabludoff, Ann I.
2006-01-01
We present a unifying empirical description of the structural and kinematic properties of all spheroids embedded in dark matter halos. We find that the stellar spheroidal components of galaxy clusters, which we call cluster spheroids (CSphs) and which are typically one hundred times the size of normal elliptical galaxies, lie on a "fundamental plane" as tight as that defined by ellipticals (rms in effective radius of ~0.07), but that has a different slope. The slope, as measured by the coefficient of the log(sigma) term, declines significantly and systematically between the fundamental planes of ellipticals, brightest cluster galaxies (BCGs), and CSphs.We attribute this decline primarily to a continuous change in M_e/L_e, the mass-to-light ratio within the effective radius r_e, with spheroid scale. The magnitude of the slope change requires that it arises principally from differences in the relative distributions of luminous and dark matter, rather than from stellar population differences such as in age and m...
Field Theory of Fundamental Interactions
Wang, Shouhong; Ma, Tian
2017-01-01
First, we present two basic principles, the principle of interaction dynamics (PID) and the principle of representation invariance (PRI). Intuitively, PID takes the variation of the action under energy-momentum conservation constraint. We show that the PID is the requirement of the presence of dark matter and dark energy, the Higgs field and the quark confinement. PRI requires that the SU(N) gauge theory be independent of representations of SU(N). It is clear that PRI is the logic requirement of any gauge theory. With PRI, we demonstrate that the coupling constants for the strong and the weak interactions are the main sources of these two interactions, reminiscent of the electric charge. Second, we emphasize that symmetry principles-the principle of general relativity and the principle of Lorentz invariance and gauge invariance-together with the simplicity of laws of nature, dictate the actions for the four fundamental interactions. Finally, we show that the PID and the PRI, together with the symmetry principles give rise to a unified field model for the fundamental interactions, which is consistent with current experimental observations and offers some new physical predictions. The research is supported in part by the National Science Foundation (NSF) grant DMS-1515024, and by the Office of Naval Research (ONR) grant N00014-15-1-2662.
O que é Psicopatologia Fundamental
Directory of Open Access Journals (Sweden)
Manoel Tosta Berlinck
Full Text Available Se para os romanos, posição significava lugar onde uma pessoa ou coisa estaria colocada, para os gregos, a noção de posição é de natureza muito mais relacional. Da posição determinada pela postura do corpo, diferenciavam pelo menos duas outras: a do historiador, que não inventa, apenas ouviu falar por aí, e a do teatro, que mostrava o corpo humano em um estado natural de pathos (sofrimento. Ao se pensar o psiquismo e o aparelho psíquico como prolongamentos do sistema imunológico e já que, segundo o autor, pathos é sempre somático, a psique é, seguindo a tradição socrática, estritamente corporal. É próprio, pois, à Psicopatologia Fundamental, reconhecer a existência de múltiplas posições corporais-discursivas e reconhecer que aqueles que ocupam outras posições reconheçam a especificidade de sua posição. A partir do conceito de posição, e seus desdobramentos em pathos e logos, o autor desenvolve sua concepção de Psicopatologia Fundamental.
Towards an accurate bioimpedance identification
Sanchez, B.; Louarroudi, E.; Bragos, R.; Pintelon, R.
2013-04-01
This paper describes the local polynomial method (LPM) for estimating the time-invariant bioimpedance frequency response function (FRF) considering both the output-error (OE) and the errors-in-variables (EIV) identification framework and compare it with the traditional cross— and autocorrelation spectral analysis techniques. The bioimpedance FRF is measured with the multisine electrical impedance spectroscopy (EIS) technique. To show the overwhelming accuracy of the LPM approach, both the LPM and the classical cross— and autocorrelation spectral analysis technique are evaluated through the same experimental data coming from a nonsteady-state measurement of time-varying in vivo myocardial tissue. The estimated error sources at the measurement frequencies due to noise, σnZ, and the stochastic nonlinear distortions, σZNL, have been converted to Ω and plotted over the bioimpedance spectrum for each framework. Ultimately, the impedance spectra have been fitted to a Cole impedance model using both an unweighted and a weighted complex nonlinear least square (CNLS) algorithm. A table is provided with the relative standard errors on the estimated parameters to reveal the importance of which system identification frameworks should be used.
Materials Fundamentals of Gate Dielectrics
Demkov, Alexander A
2006-01-01
This book presents materials fundamentals of novel gate dielectrics that are being introduced into semiconductor manufacturing to ensure the continuous scalling of the CMOS devices. This is a very fast evolving field of research so we choose to focus on the basic understanding of the structure, thermodunamics, and electronic properties of these materials that determine their performance in device applications. Most of these materials are transition metal oxides. Ironically, the d-orbitals responsible for the high dielectric constant cause sever integration difficulties thus intrinsically limiting high-k dielectrics. Though new in the electronics industry many of these materials are wel known in the field of ceramics, and we describe this unique connection. The complexity of the structure-property relations in TM oxides makes the use of the state of the art first-principles calculations necessary. Several chapters give a detailed description of the modern theory of polarization, and heterojunction band discont...
Polyhedral Scattering of Fundamental Monopoles
Battye, R; Rychenkova, P; Sutcliffe, P; Battye, Richard; Gibbons, Gary; Rychenkova, Paulina; Sutcliffe, Paul
2003-01-01
The dynamics of n slowly moving fundamental monopoles in the SU(n+1) BPS Yang-Mills-Higgs theory can be approximated by geodesic motion on the 4n-dimensional hyperkahler Lee-Weinberg-Yi manifold. In this paper we apply a variational method to construct some scaling geodesics on this manifold. These geodesics describe the scattering of n monopoles which lie on the vertices of a bouncing polyhedron; the polyhedron contracts from infinity to a point, representing the spherically symmetric n-monopole, and then expands back out to infinity. For different monopole masses the solutions generalize to form bouncing nested polyhedra. The relevance of these results to the dynamics of well separated SU(2) monopoles is also discussed.
Silicon photonics fundamentals and devices
Deen, M Jamal
2012-01-01
The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...
Fundamentals of Condensed Matter Physics
Cohen, Marvin L.; Louie, Steven G.
2016-05-01
Part I. Basic Concepts: Electrons and Phonons: 1. Concept of a solid: qualitative introduction and overview; 2. Electrons in crystals; 3. Electronic energy bands; 4. Lattice vibrations and phonons; Part II. Electron Intercations, Dynamics and Responses: 5. Electron dynamics in crystals; 6. Many-electron interactions: the interacting electron gas and beyond; 7. Density functional theory; 8. The dielectric function for solids; Part III. Optical and Transport Phenomena: 9. Electronic transitions and optical properties of solids; 10. Electron-phonon interactions; 11. Dynamics of crystal electrons in a magnetic field; 12. Fundamentals of transport phenomena in solids; Part IV. Superconductivity, Magnetism, and Lower Dimensional Systems: 13. Using many-body techniques; 14. Superconductivity; 15. Magnetism; 16. Reduced-dimensional systems and nanostructures; Index.
Queueing networks a fundamental approach
Dijk, Nico
2011-01-01
This handbook aims to highlight fundamental, methodological and computational aspects of networks of queues to provide insights and to unify results that can be applied in a more general manner. The handbook is organized into five parts: Part 1 considers exact analytical results such as of product form type. Topics include characterization of product forms by physical balance concepts and simple traffic flow equations, classes of service and queue disciplines that allow a product form, a unified description of product forms for discrete time queueing networks, insights for insensitivity, and aggregation and decomposition results that allow subnetworks to be aggregated into single nodes to reduce computational burden. Part 2 looks at monotonicity and comparison results such as for computational simplification by either of two approaches: stochastic monotonicity and ordering results based on the ordering of the proces generators, and comparison results and explicit error bounds based on an underlying Markov r...
Fundamental triangulation networks in Denmark
Directory of Open Access Journals (Sweden)
Borre Kai
2014-04-01
Full Text Available The first triangulation activity on Danish ground was carried out by the astronomer Tycho Brahe who resided on the island Hven. He wanted to determine the longitude difference of his observatory Uraniborg to Copenhagen. A by-product was a map of his island made in 1579. In 1761 the Royal Danish Academy of Sciences and Letters initiated a mapping project which should be based on the principle of triangulation. Eventually 24 maps were printed in varying scales, predominantly in 1:120 000. The last map was engraved in 1842. The Danish GradeMeasurement initiated remeasurements and redesign of the fundamental triangulation network. This network served scientific as well as cartographic purposes in more than a century. Only in the 1960s all triangulation sides were measured electronically. A combined least-squares adjustment followed in the 1970s
Overview: Main Fundamentals for Steganography
AL-Ani, Zaidoon Kh; Zaidan, B B; Alanazi, Hamdan O
2010-01-01
The rapid development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information .Besides that, digital documents are also easy to copy and distribute, therefore it will be faced by many threats. It is a big security and privacy issue, it become necessary to find appropriate protection because of the significance, accuracy and sensitivity of the information. Steganography considers one of the techniques which used to protect the important information. The main goals for this paper, to recognize the researchers for the main fundamentals of steganography. In this paper provides a general overview of the following subject areas: Steganography types, General Steganography system, Characterization of Steganography Systems and Classification of Steganography Techniques.
Astronomical reach of fundamental physics.
Burrows, Adam S; Ostriker, Jeremiah P
2014-02-18
Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.
Phononic crystals fundamentals and applications
Adibi, Ali
2016-01-01
This book provides an in-depth analysis as well as an overview of phononic crystals. This book discusses numerous techniques for the analysis of phononic crystals and covers, among other material, sonic and ultrasonic structures, hypersonic planar structures and their characterization, and novel applications of phononic crystals. This is an ideal book for those working with micro and nanotechnology, MEMS (microelectromechanical systems), and acoustic devices. This book also: Presents an introduction to the fundamentals and properties of phononic crystals Covers simulation techniques for the analysis of phononic crystals Discusses sonic and ultrasonic, hypersonic and planar, and three-dimensional phononic crystal structures Illustrates how phononic crystal structures are being deployed in communication systems and sensing systems.
Fundamentals of Protein NMR Spectroscopy
Rule, Gordon S
2006-01-01
NMR spectroscopy has proven to be a powerful technique to study the structure and dynamics of biological macromolecules. Fundamentals of Protein NMR Spectroscopy is a comprehensive textbook that guides the reader from a basic understanding of the phenomenological properties of magnetic resonance to the application and interpretation of modern multi-dimensional NMR experiments on 15N/13C-labeled proteins. Beginning with elementary quantum mechanics, a set of practical rules is presented and used to describe many commonly employed multi-dimensional, multi-nuclear NMR pulse sequences. A modular analysis of NMR pulse sequence building blocks also provides a basis for understanding and developing novel pulse programs. This text not only covers topics from chemical shift assignment to protein structure refinement, as well as the analysis of protein dynamics and chemical kinetics, but also provides a practical guide to many aspects of modern spectrometer hardware, sample preparation, experimental set-up, and data pr...
Optical Metamaterials Fundamentals and Applications
Cai, Wenshan
2010-01-01
Metamaterials—artificially structured materials with engineered electromagnetic properties—have enabled unprecedented flexibility in manipulating electromagnetic waves and producing new functionalities. In just a few years, the field of optical metamaterials has emerged as one of the most exciting topics in the science of light, with stunning and unexpected outcomes that have fascinated scientists and the general public alike. This volume details recent advances in the study of optical metamaterials, ranging from fundamental aspects to up-to-date implementations, in one unified treatment. Important recent developments and applications such as superlenses and cloaking devices are also treated in detail and made understandable. Optical Metamaterials will serve as a very timely book for both newcomers and advanced researchers in this rapidly evolving field. Early praise for Optical Metamaterials: "...this book is timely bringing to students and other new entrants to the field the most up to date concepts. Th...
Fundamentals of reversible flowchart languages
DEFF Research Database (Denmark)
Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert
2016-01-01
. Although reversible flowcharts are superficially similar to classical flowcharts, there are crucial differences: atomic steps are limited to locally invertible operations, and join points require an explicit orthogonalizing conditional expression. Despite these constraints, we show that reversible......Abstract This paper presents the fundamentals of reversible flowcharts. They are intended to naturally represent the structure and control flow of reversible (imperative) programming languages in a simple computation model, in the same way classical flowcharts do for conventional languages......, structured reversible flowcharts are as expressive as unstructured ones, as shown by a reversible version of the classic Structured Program Theorem. We illustrate how reversible flowcharts can be concretized with two example programming languages, complete with syntax and semantics: a low-level unstructured...
Molecular imaging. Fundamentals and applications
Energy Technology Data Exchange (ETDEWEB)
Tian, Jie (ed.) [Chinese Academy of Sciences, Beijing (China). Intelligent Medical Research Center
2013-07-01
Covers a wide range of new theory, new techniques and new applications. Contributed by many experts in China. The editor has obtained the National Science and Technology Progress Award twice. ''Molecular Imaging: Fundamentals and Applications'' is a comprehensive monograph which describes not only the theory of the underlying algorithms and key technologies but also introduces a prototype system and its applications, bringing together theory, technology and applications. By explaining the basic concepts and principles of molecular imaging, imaging techniques, as well as research and applications in detail, the book provides both detailed theoretical background information and technical methods for researchers working in medical imaging and the life sciences. Clinical doctors and graduate students will also benefit from this book.
Astronomical reach of fundamental physics
Burrows, Adam S.; Ostriker, Jeremiah P.
2014-02-01
Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.
Fluid mechanics fundamentals and applications
Cengel, Yunus
2013-01-01
Cengel and Cimbala's Fluid Mechanics Fundamentals and Applications, communicates directly with tomorrow's engineers in a simple yet precise manner. The text covers the basic principles and equations of fluid mechanics in the context of numerous and diverse real-world engineering examples. The text helps students develop an intuitive understanding of fluid mechanics by emphasizing the physics, using figures, numerous photographs and visual aids to reinforce the physics. The highly visual approach enhances the learning of Fluid mechanics by students. This text distinguishes itself from others by the way the material is presented - in a progressive order from simple to more difficult, building each chapter upon foundations laid down in previous chapters. In this way, even the traditionally challenging aspects of fluid mechanics can be learned effectively. McGraw-Hill is also proud to offer ConnectPlus powered by Maple with the third edition of Cengel/Cimbabla, Fluid Mechanics. This innovative and powerful new sy...
Fundamentals of modern unsteady aerodynamics
Gülçat, Ülgen
2016-01-01
In this book, the author introduces the concept of unsteady aerodynamics and its underlying principles. He provides the readers with a comprehensive review of the fundamental physics of free and forced unsteadiness, the terminology and basic equations of aerodynamics ranging from incompressible flow to hypersonics. The book also covers modern topics related to the developments made in recent years, especially in relation to wing flapping for propulsion. The book is written for graduate and senior year undergraduate students in aerodynamics and also serves as a reference for experienced researchers. Each chapter includes ample examples, questions, problems and relevant references. The treatment of these modern topics has been completely revised end expanded for the new edition. It now includes new numerical examples, a section on the ground effect, and state-space representation.
Green Manufacturing Fundamentals and Applications
2013-01-01
Green Manufacturing: Fundamentals and Applications introduces the basic definitions and issues surrounding green manufacturing at the process, machine and system (including supply chain) levels. It also shows, by way of several examples from different industry sectors, the potential for substantial improvement and the paths to achieve the improvement. Additionally, this book discusses regulatory and government motivations for green manufacturing and outlines the path for making manufacturing more green as well as making production more sustainable. This book also: • Discusses new engineering approaches for manufacturing and provides a path from traditional manufacturing to green manufacturing • Addresses regulatory and economic issues surrounding green manufacturing • Details new supply chains that need to be in place before going green • Includes state-of-the-art case studies in the areas of automotive, semiconductor and medical areas as well as in the supply chain and packaging areas Green Manufactu...
Accurate speed and slip measurement of induction motors
Energy Technology Data Exchange (ETDEWEB)
Ho, S.Y.S.; Langman, R. [Tasmania Univ., Hobart, TAS (Australia)
1996-03-01
Two alternative hardware circuits, for the accurate measurement of low slip in cage induction motors, are discussed. Both circuits compare the periods of the fundamental of the supply frequency and pulses from a shaft-connected toothed-wheel. The better of the two achieves accuracy to 0.5 percent of slip over the range 0.1 to 0.005, or better than 0.001 percent of speed over the range. This method is considered useful for slip measurement of motors supplied by either constant frequency mains of variable speed controllers with PMW waveforms. It is demonstrated that accurate slip measurement supports the conclusions of work previously done on the detection of broken rotor bars. (author). 1 tab., 6 figs., 13 refs.
Fundamental enabling issues in nanotechnology :
Energy Technology Data Exchange (ETDEWEB)
Floro, Jerrold Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foiles, Stephen Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hearne, Sean Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoyt, Jeffrey John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seel, Steven Craig [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Webb III, Edmund Blackburn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Morales, Alfredo Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zimmerman, Jonathan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2007-10-01
To effectively integrate nanotechnology into functional devices, fundamental aspects of material behavior at the nanometer scale must be understood. Stresses generated during thin film growth strongly influence component lifetime and performance; stress has also been proposed as a mechanism for stabilizing supported nanoscale structures. Yet the intrinsic connections between the evolving morphology of supported nanostructures and stress generation are still a matter of debate. This report presents results from a combined experiment and modeling approach to study stress evolution during thin film growth. Fully atomistic simulations are presented predicting stress generation mechanisms and magnitudes during all growth stages, from island nucleation to coalescence and film thickening. Simulations are validated by electrodeposition growth experiments, which establish the dependence of microstructure and growth stresses on process conditions and deposition geometry. Sandia is one of the few facilities with the resources to combine experiments and modeling/theory in this close a fashion. Experiments predicted an ongoing coalescence process that generates signficant tensile stress. Data from deposition experiments also supports the existence of a kinetically limited compressive stress generation mechanism. Atomistic simulations explored island coalescence and deposition onto surfaces intersected by grain boundary structures to permit investigation of stress evolution during later growth stages, e.g. continual island coalescence and adatom incorporation into grain boundaries. The predictive capabilities of simulation permit direct determination of fundamental processes active in stress generation at the nanometer scale while connecting those processes, via new theory, to continuum models for much larger island and film structures. Our combined experiment and simulation results reveal the necessary materials science to tailor stress, and therefore performance, in
38 CFR 4.46 - Accurate measurement.
2010-07-01
... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...
Planck intermediate results XXIV. Constraints on variations in fundamental constants
DEFF Research Database (Denmark)
Ade, P. A. R.; Aghanim, N.; Arnaud, M.;
2015-01-01
Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data...... of the electron, me, and in the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other...
High precision fundamental constants at the TeV scale
Moch, S; Alekhin, S; Blumlein, J; de la Cruz, L; Dittmaier, S; Dowling, M; Erler, J; Espinosa, J R; Fuster, J; Tormo, X Garcia i; Hoang, A H; Huss, A; Kluth, S; Mulders, M; Papanastasiou, A S; Piclum, J; Rabbertz, K; Schwinn, C; Schulze, M; Shintani, E; Uwer, P; Zerf, N
2014-01-01
This report summarizes the proceedings of the 2014 Mainz Institute for Theoretical Physics (MITP) scientific program on "High precision fundamental constants at the TeV scale". The two outstanding parameters in the Standard Model dealt with during the MITP scientific program are the strong coupling constant $\\alpha_s$ and the top-quark mass $m_t$. Lacking knowledge on the value of those fundamental constants is often the limiting factor in the accuracy of theoretical predictions. The current status on $\\alpha_s$ and $m_t$ has been reviewed and directions for future research have been identified.
2014-10-08
models to compute accurately the molecular interactions between a mobile or stationary phase and a target substrate or analyte , which are fundamental...mobile or stationary phase and a target substrate or analyte , which are fundamental to diverse technologies, e.g., sensor or separation design. With...D. G., New Orleans, LA, April 9, 2013. 223rd Electrochemical Society Meeting, Continuum Solvation Models for Computational Electrochemistry
Propagation channel characterization, parameter estimation, and modeling for wireless communications
Yin, Xuefeng
2016-01-01
Thoroughly covering channel characteristics and parameters, this book provides the knowledge needed to design various wireless systems, such as cellular communication systems, RFID and ad hoc wireless communication systems. It gives a detailed introduction to aspects of channels before presenting the novel estimation and modelling techniques which can be used to achieve accurate models. To systematically guide readers through the topic, the book is organised in three distinct parts. The first part covers the fundamentals of the characterization of propagation channels, including the conventional single-input single-output (SISO) propagation channel characterization as well as its extension to multiple-input multiple-output (MIMO) cases. Part two focuses on channel measurements and channel data post-processing. Wideband channel measurements are introduced, including the equipment, technology and advantages and disadvantages of different data acquisition schemes. The channel parameter estimation methods are ...
How Do Fundamental Christians Deal with Depression?
Spinney, Douglas Harvey
1991-01-01
Provides explanation of developmental dynamics in experience of fundamental Christians that provoke reactive depression. Describes depressant retardant defenses against depression that have been observed in Christian fundamental subculture. Suggests four counseling strategies for helping fundamentalists. (Author/ABL)
Fundamentals of statistical signal processing
Kay, Steven M
1993-01-01
A unified presentation of parameter estimation for those involved in the design and implementation of statistical signal processing algorithms. Covers important approaches to obtaining an optimal estimator and analyzing its performance; and includes numerous examples as well as applications to real- world problems. MARKETS: For practicing engineers and scientists who design and analyze signal processing systems, i.e., to extract information from noisy signals — radar engineer, sonar engineer, geophysicist, oceanographer, biomedical engineer, communications engineer, economist, statistician, physicist, etc.
Virtual and composite fundamentals in the ERM
Knot, KHW; Sturm, JE
1999-01-01
A latent-variable approach is applied to identify the appropriate driving process for fundamental exchange rates in the ERM. From the time-series characteristics of so-called "virtual fundamentals" and "composite fundamentals", a significant degree of mean reversion can be asserted. The relative deg
Information physics fundamentals of nanophotonics.
Naruse, Makoto; Tate, Naoya; Aono, Masashi; Ohtsu, Motoichi
2013-05-01
Nanophotonics has been extensively studied with the aim of unveiling and exploiting light-matter interactions that occur at a scale below the diffraction limit of light, and recent progress made in experimental technologies--both in nanomaterial fabrication and characterization--is driving further advancements in the field. From the viewpoint of information, on the other hand, novel architectures, design and analysis principles, and even novel computing paradigms should be considered so that we can fully benefit from the potential of nanophotonics. This paper examines the information physics aspects of nanophotonics. More specifically, we present some fundamental and emergent information properties that stem from optical excitation transfer mediated by optical near-field interactions and the hierarchical properties inherent in optical near-fields. We theoretically and experimentally investigate aspects such as unidirectional signal transfer, energy efficiency and networking effects, among others, and we present their basic theoretical formalisms and describe demonstrations of practical applications. A stochastic analysis of light-assisted material formation is also presented, where an information-based approach provides a deeper understanding of the phenomena involved, such as self-organization. Furthermore, the spatio-temporal dynamics of optical excitation transfer and its inherent stochastic attributes are utilized for solution searching, paving the way to a novel computing paradigm that exploits coherent and dissipative processes in nanophotonics.
Fundamental Scaling Laws in Nanophotonics.
Liu, Ke; Sun, Shuai; Majumdar, Arka; Sorger, Volker J
2016-11-21
The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of "smaller-is-better" has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoelectronic device performance scales non-monotonically with device length due to the various device tradeoffs, and analyze how both optical and electrical constrains influence device power consumption and operating speed. Specifically, we investigate the direct influence of scaling on the performance of four classes of photonic devices, namely laser sources, electro-optic modulators, photodetectors, and all-optical switches based on three types of optical resonators; microring, Fabry-Perot cavity, and plasmonic metal nanoparticle. Results show that while microrings and Fabry-Perot cavities can outperform plasmonic cavities at larger length-scales, they stop working when the device length drops below 100 nanometers, due to insufficient functionality such as feedback (laser), index-modulation (modulator), absorption (detector) or field density (optical switch). Our results provide a detailed understanding of the limits of nanophotonics, towards establishing an opto-electronics roadmap, akin to the International Technology Roadmap for Semiconductors.
Levitated Optomechanics for Fundamental Physics
Rashid, Muddassar; Bateman, James; Vovrosh, Jamie; Hempston, David; Ulbricht, Hendrik
2015-05-01
Optomechanics with levitated nano- and microparticles is believed to form a platform for testing fundamental principles of quantum physics, as well as find applications in sensing. We will report on a new scheme to trap nanoparticles, which is based on a parabolic mirror with a numerical aperture of 1. Combined with achromatic focussing, the setup is a cheap and readily straightforward solution to trapping nanoparticles for further study. Here, we report on the latest progress made in experimentation with levitated nanoparticles; these include the trapping of 100 nm nanodiamonds (with NV-centres) down to 1 mbar as well as the trapping of 50 nm Silica spheres down to 10?4 mbar without any form of feedback cooling. We will also report on the progress to implement feedback stabilisation of the centre of mass motion of the trapped particle using digital electronics. Finally, we argue that such a stabilised particle trap can be the particle source for a nanoparticle matterwave interferometer. We will present our Talbot interferometer scheme, which holds promise to test the quantum superposition principle in the new mass range of 106 amu. EPSRC, John Templeton Foundation.
Fundamental Scaling Laws in Nanophotonics
Liu, Ke; Sun, Shuai; Majumdar, Arka; Sorger, Volker J.
2016-11-01
The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of “smaller-is-better” has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoelectronic device performance scales non-monotonically with device length due to the various device tradeoffs, and analyze how both optical and electrical constrains influence device power consumption and operating speed. Specifically, we investigate the direct influence of scaling on the performance of four classes of photonic devices, namely laser sources, electro-optic modulators, photodetectors, and all-optical switches based on three types of optical resonators; microring, Fabry-Perot cavity, and plasmonic metal nanoparticle. Results show that while microrings and Fabry-Perot cavities can outperform plasmonic cavities at larger length-scales, they stop working when the device length drops below 100 nanometers, due to insufficient functionality such as feedback (laser), index-modulation (modulator), absorption (detector) or field density (optical switch). Our results provide a detailed understanding of the limits of nanophotonics, towards establishing an opto-electronics roadmap, akin to the International Technology Roadmap for Semiconductors.
Fundamental studies of fusion plasmas
Energy Technology Data Exchange (ETDEWEB)
Aamodt, R.E.; Catto, P.J.; D' Ippolito, D.A.; Myra, J.R.; Russell, D.A.
1992-05-26
The major portion of this program is devoted to critical ICH phenomena. The topics include edge physics, fast wave propagation, ICH induced high frequency instabilities, and a preliminary antenna design for Ignitor. This research was strongly coordinated with the world's experimental and design teams at JET, Culham, ORNL, and Ignitor. The results have been widely publicized at both general scientific meetings and topical workshops including the speciality workshop on ICRF design and physics sponsored by Lodestar in April 1992. The combination of theory, empirical modeling, and engineering design in this program makes this research particularly important for the design of future devices and for the understanding and performance projections of present tokamak devices. Additionally, the development of a diagnostic of runaway electrons on TEXT has proven particularly useful for the fundamental understanding of energetic electron confinement. This work has led to a better quantitative basis for quasilinear theory and the role of magnetic vs. electrostatic field fluctuations on electron transport. An APS invited talk was given on this subject and collaboration with PPPL personnel was also initiated. Ongoing research on these topics will continue for the remainder fo the contract period and the strong collaborations are expected to continue, enhancing both the relevance of the work and its immediate impact on areas needing critical understanding.
IDDT: Fundamentals and Test Generation
Institute of Scientific and Technical Information of China (English)
KUANG JiShun(邝继顺); YOU ZhiQiang(尤志强); ZHU QiJian(朱启建); MIN YingHua(闵应骅)
2003-01-01
It is the time to explore the fundamentals of IDDT testing when extensive workhas been done for IDDT testing since it was proposed. This paper precisely defines the concept ofaverage transient current (IDDT) of CMOS digital ICs, and experimentally analyzes the feasibilityof IDDT test generation at gate level. Based on the SPICE simulation results, the paper suggests aformula to calculateIDDT by means of counting only logical up-transitions, which enablesIDDT testgeneration at logic level. The Bayesian optimization algorithm is utilized for IDDT test generation.Experimental results show that about 25% stuck-open faults are withIDDT testability larger than2.5, and likely to beIDDT testable. It is also found that most IDDT testable faults are located nearthe primary inputs of a circuit under test. IDDT test generation does not require fault sensitizationprocedure compared with stuck-at fault test generation. Furthermore, some redundant stuck-atfaults can be detected by using IDDT testing.
Fluorescence lifetimes: fundamentals and interpretations.
Noomnarm, Ulai; Clegg, Robert M
2009-01-01
Fluorescence measurements have been an established mainstay of photosynthesis experiments for many decades. Because in the photosynthesis literature the basics of excited states and their fates are not usually described, we have presented here an easily understandable text for biology students in the style of a chapter in a text book. In this review we give an educational overview of fundamental physical principles of fluorescence, with emphasis on the temporal response of emission. Escape from the excited state of a molecule is a dynamic event, and the fluorescence emission is in direct kinetic competition with several other pathways of de-excitation. It is essentially through a kinetic competition between all the pathways of de-excitation that we gain information about the fluorescent sample on the molecular scale. A simple probability allegory is presented that illustrates the basic ideas that are important for understanding and interpreting most fluorescence experiments. We also briefly point out challenges that confront the experimenter when interpreting time-resolved fluorescence responses.
The weak fundamental NH-stretching transition in amines
Schrøder, Sidsel D.; Hansen, Anne S.; Wallberg, Jens H.; Nielsen, Anne R.; Du, Lin; Kjaergaard, Henrik G.
2017-02-01
Absolute intensities of NH-stretching fundamental and overtone transitions of gas phase aniline, methylamine, ethylamine, cyclopropylamine, methylethylamine, diethylamine and pyrrolidine have been measured with long path length conventional absorption spectroscopy. To support the assignments of NH-stretching transitions, transition frequencies and intensities were calculated with the local mode model using ab initio calculated local mode parameters and dipole moment functions obtained at the CCSD(T)-F12a/VDZ-F12 level of theory. For aniline, the absolute intensities of the NH-stretching transitions show the typical decrease of approximately an order of magnitude for each successive vibrational excitation. For methylamine, ethylamine, cyclopropylamine, methylethylamine, diethylamine and pyrrolidine, the observed absolute intensities of the fundamental NH-stretching transition is weak and of similar strength or even weaker than the corresponding first overtone transition. Characteristic for the amines with a normal fundamental intensity is a conjugated double bond next to the amine group.
Fundamental Frequency and Model Order Estimation Using Spatial Filtering
DEFF Research Database (Denmark)
Karimian-Azari, Sam; Jensen, Jesper Rindom; Christensen, Mads Græsbøll
2014-01-01
extend this procedure to account for inharmonicity using unconstrained model order estimation. The simulations show that beamforming improves the performance of the joint estimates of fundamental frequency and the number of harmonics in low signal to interference (SIR) levels, and an experiment......In signal processing applications of harmonic-structured signals, estimates of the fundamental frequency and number of harmonics are often necessary. In real scenarios, a desired signal is contaminated by different levels of noise and interferers, which complicate the estimation of the signal...... parameters. In this paper, we present an estimation procedure for harmonic-structured signals in situations with strong interference using spatial filtering, or beamforming. We jointly estimate the fundamental frequency and the constrained model order through the output of the beamformers. Besides that, we...
Fundamental structures of dynamic social networks.
Sekara, Vedran; Stopczynski, Arkadiusz; Lehmann, Sune
2016-09-06
Social systems are in a constant state of flux, with dynamics spanning from minute-by-minute changes to patterns present on the timescale of years. Accurate models of social dynamics are important for understanding the spreading of influence or diseases, formation of friendships, and the productivity of teams. Although there has been much progress on understanding complex networks over the past decade, little is known about the regularities governing the microdynamics of social networks. Here, we explore the dynamic social network of a densely-connected population of ∼1,000 individuals and their interactions in the network of real-world person-to-person proximity measured via Bluetooth, as well as their telecommunication networks, online social media contacts, geolocation, and demographic data. These high-resolution data allow us to observe social groups directly, rendering community detection unnecessary. Starting from 5-min time slices, we uncover dynamic social structures expressed on multiple timescales. On the hourly timescale, we find that gatherings are fluid, with members coming and going, but organized via a stable core of individuals. Each core represents a social context. Cores exhibit a pattern of recurring meetings across weeks and months, each with varying degrees of regularity. Taken together, these findings provide a powerful simplification of the social network, where cores represent fundamental structures expressed with strong temporal and spatial regularity. Using this framework, we explore the complex interplay between social and geospatial behavior, documenting how the formation of cores is preceded by coordination behavior in the communication networks and demonstrating that social behavior can be predicted with high precision.
Estimation of physical parameters in induction motors
DEFF Research Database (Denmark)
Børsting, H.; Knudsen, Morten; Rasmussen, Henrik
1994-01-01
Parameter estimation in induction motors is a field of great interest, because accurate models are needed for robust dynamic control of induction motors......Parameter estimation in induction motors is a field of great interest, because accurate models are needed for robust dynamic control of induction motors...
On accurate boundary conditions for a shape sensitivity equation method
Duvigneau, R.; Pelletier, D.
2006-01-01
This paper studies the application of the continuous sensitivity equation method (CSEM) for the Navier-Stokes equations in the particular case of shape parameters. Boundary conditions for shape parameters involve flow derivatives at the boundary. Thus, accurate flow gradients are critical to the success of the CSEM. A new approach is presented to extract accurate flow derivatives at the boundary. High order Taylor series expansions are used on layered patches in conjunction with a constrained least-squares procedure to evaluate accurate first and second derivatives of the flow variables at the boundary, required for Dirichlet and Neumann sensitivity boundary conditions. The flow and sensitivity fields are solved using an adaptive finite-element method. The proposed methodology is first verified on a problem with a closed form solution obtained by the Method of Manufactured Solutions. The ability of the proposed method to provide accurate sensitivity fields for realistic problems is then demonstrated. The flow and sensitivity fields for a NACA 0012 airfoil are used for fast evaluation of the nearby flow over an airfoil of different thickness (NACA 0015).
Accurate and Simple Calibration of DLP Projector Systems
Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus
2014-01-01
Much work has been devoted to the calibration of optical cameras, and accurate and simple methods are now available which require only a small number of calibration targets. The problem of obtaining these parameters for light projectors has not been studied as extensively and most current methods require a camera and involve feature extraction from a known projected pattern. In this work we present a novel calibration technique for DLP Projector systems based on phase shifting profilometry pr...
Optimizing cell arrays for accurate functional genomics
Directory of Open Access Journals (Sweden)
Fengler Sven
2012-07-01
Full Text Available Abstract Background Cellular responses emerge from a complex network of dynamic biochemical reactions. In order to investigate them is necessary to develop methods that allow perturbing a high number of gene products in a flexible and fast way. Cell arrays (CA enable such experiments on microscope slides via reverse transfection of cellular colonies growing on spotted genetic material. In contrast to multi-well plates, CA are susceptible to contamination among neighboring spots hindering accurate quantification in cell-based screening projects. Here we have developed a quality control protocol for quantifying and minimizing contamination in CA. Results We imaged checkered CA that express two distinct fluorescent proteins and segmented images into single cells to quantify the transfection efficiency and interspot contamination. Compared with standard procedures, we measured a 3-fold reduction of contaminants when arrays containing HeLa cells were washed shortly after cell seeding. We proved that nucleic acid uptake during cell seeding rather than migration among neighboring spots was the major source of contamination. Arrays of MCF7 cells developed without the washing step showed 7-fold lower percentage of contaminant cells, demonstrating that contamination is dependent on specific cell properties. Conclusions Previously published methodological works have focused on achieving high transfection rate in densely packed CA. Here, we focused in an equally important parameter: The interspot contamination. The presented quality control is essential for estimating the rate of contamination, a major source of false positives and negatives in current microscopy based functional genomics screenings. We have demonstrated that a washing step after seeding enhances CA quality for HeLA but is not necessary for MCF7. The described method provides a way to find optimal seeding protocols for cell lines intended to be used for the first time in CA.
Astronomia Motivadora no Ensino Fundamental
Melo, J.; Voelzke, M. R.
2008-09-01
O objetivo principal deste trabalho é procurar desenvolver o interesse dos alunos pelas ciências através da Astronomia. Uma pesquisa com perguntas sobre Astronomia foi realizada junto a 161 alunos do Ensino Fundamental, com o intuito de descobrir conhecimentos prévios dos alunos sobre o assunto. Constatou-se, por exemplo, que 29,3% da 6Âª série responderam corretamente o que é eclipse, 30,0% da 8Âª série acertaram o que a Astronomia estuda, enquanto 42,3% dos alunos da 5Âª série souberam definir o Sol. Pretende-se ampliar as turmas participantes e trabalhar, principalmente de forma prática com: dimensões e escalas no Sistema Solar, construção de luneta, questões como dia e noite, estações do ano e eclipses. Busca-se abordar, também, outros conteúdos de Física tais como a óptica na construção da luneta, e a mecânica no trabalho com escalas e medidas, e ao utilizar uma luminária para representar o Sol na questão do eclipse, e de outras disciplinas como a Matemática na transformação de unidades, regras de três; Artes na modelagem ou desenho dos planetas; a própria História com relação à busca pela origem do universo, e a Informática que possibilita a busca mais rápida por informações, além de permitir simulações e visualizações de imagens importantes. Acredita-se que a Astronomia é importante no processo ensino aprendizagem, pois permite a discussão de temas curiosos como, por exemplo, a origem do universo, viagens espaciais a existência ou não de vida em outros planetas, além de temas atuais como as novas tecnologias.
Cold Atom Clocks, Precision Oscillators and Fundamental Tests
Bize, S; Abgrall, M; Cacciapuoti, L; Clairon, A; Gruenert, J; Laurent, P; Lemonde, P; Maksimovic, I; Mandache, C; Marion, H; Dos Santos, F P; Rosenbusch, P; Santarelli, G; Sortais, Y; Vian, C; Zhang, S; Salomon, C; Luiten, A N; Tobar, M E; Laurent, Ph.
2003-01-01
We describe two experimental tests of the Equivalence Principle that are based on frequency measurements between precision oscillators and/or highly accurate atomic frequency standards. Based on comparisons between the hyperfine frequencies of 87Rb and 133Cs in atomic fountains, the first experiment constrains the stability of fundamental constants. The second experiment is based on a comparison between a cryogenic sapphire oscillator and a hydrogen maser. It tests Local Lorentz Invariance. In both cases, we report recent results which improve significantly over previous experiments.
Coupled variations of fundamental couplings and primordial nucleosynthesis
Energy Technology Data Exchange (ETDEWEB)
Coc, Alain [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, IN2P3/CNRS/UPS, Bat. 104, 91405 0rsay Campus (France); Nunes, Nelson J.; Olive, Keith A. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN 55455 (United States); Uzan, Jean-Philippe; Vangioni, Elisabeth [Institut d' Astrophysique de Paris, UMR-7095 du CNRS, Universite Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France)
2006-10-15
The effect of variations of the fundamental nuclear parameters on big-bang nucleosynthesis are modeled and discussed in detail taking into account the interrelations between the fundamental parameters arising in unified theories. Considering only {sup 4}He, strong constraints on the variation of the neutron lifetime, neutron-proton mass difference are set. These constraints are then translated into constraints on the time variation of the Yukawa couplings and the fine structure constant. Furthermore, we show that a variation of the deuterium binding energy is able to reconcile the {sup 7}Li abundance deduced from the WMAP analysis with its spectroscopically determined value while maintaining concordance with D and {sup 4}He. (authors)
Forward and inverse problems in fundamental and applied magnetohydrodynamics
2012-01-01
This Minireview summarizes the recent efforts to solve forward and inverse problems as they occur in different branches of fundamental and applied magnetohydrodynamics. As for the forward problem, the main focus is on the numerical treatment of induction processes, including self-excitation of magnetic fields in non-spherical domains and/or under the influence of non-homogeneous material parameters. As an important application of the developed numerical schemes, the functioning of the von-K\\'...
Accurate genome relative abundance estimation based on shotgun metagenomic reads.
Directory of Open Access Journals (Sweden)
Li C Xia
Full Text Available Accurate estimation of microbial community composition based on metagenomic sequencing data is fundamental for subsequent metagenomics analysis. Prevalent estimation methods are mainly based on directly summarizing alignment results or its variants; often result in biased and/or unstable estimates. We have developed a unified probabilistic framework (named GRAMMy by explicitly modeling read assignment ambiguities, genome size biases and read distributions along the genomes. Maximum likelihood method is employed to compute Genome Relative Abundance of microbial communities using the Mixture Model theory (GRAMMy. GRAMMy has been demonstrated to give estimates that are accurate and robust across both simulated and real read benchmark datasets. We applied GRAMMy to a collection of 34 metagenomic read sets from four metagenomics projects and identified 99 frequent species (minimally 0.5% abundant in at least 50% of the data-sets in the human gut samples. Our results show substantial improvements over previous studies, such as adjusting the over-estimated abundance for Bacteroides species for human gut samples, by providing a new reference-based strategy for metagenomic sample comparisons. GRAMMy can be used flexibly with many read assignment tools (mapping, alignment or composition-based even with low-sensitivity mapping results from huge short-read datasets. It will be increasingly useful as an accurate and robust tool for abundance estimation with the growing size of read sets and the expanding database of reference genomes.
Astronomers Gain Clues About Fundamental Physics
2005-12-01
superstring theory and extra dimensions in spacetime calling for the "constants" to change over time, he said. The astronomers used the GBT to detect and study radio emissions at four specific frequencies between 1612 MHz and 1720 MHz coming from hydroxyl (OH) molecules in a galaxy more than 6 billion light-years from Earth, seen as it was at roughly half the Universe's current age. Each of the four frequencies represents a specific change in the energy level of the molecule. The exact frequency emitted or absorbed when the molecule undergoes a transition from one energy level to another depends on the values of the fundamental physical constants. However, each of the four frequencies studied in the OH molecule will react differently to a change in the constants. That difference is what the astronomers sought to detect using the GBT, which, Kanekar explained, is the ideal telescope for this work because of its technical capabilities and its location in the National Radio Quiet Zone, where radio interference is at a minimum. "We can place very tight limits on changes in the physical constants by studying the behavior of these OH molecules at a time when the Universe was only about half its current age, and comparing this result to how the molecules behave today in the laboratory," said Karl Menten of the Max-Planck Institute for Radioastronomy in Germany. Wetterich, a theorist, welcomes the new capability, saying the observational method "seems very promising to obtain perhaps the most accurate values for such possible time changes of the constants." He pointed out that, while some theoretical models call for the constants to change only in the early moments after the Big Bang, models of the recently-discovered, mysterious "dark energy" that seems to be accelerating the Universe's expansion call for changes "even in the last couple of billion years." "Only observations can tell," he said. This research ties together the theoretical and observational work of Wetterich and
Towards a fundamentally new understanding of the marine atmospheric boundary layer
DEFF Research Database (Denmark)
Smedman, Ann-Sofi; Högström, U.; Larsén, Xiaoli Guo;
2004-01-01
Accurate parameterization of the turbulent exchange of momentum, sensible and latent heat at the surface of the ocean is of fundamental importance for numerical climate prediction and weather forecasting. Based on data from ships and near-shore platforms schemes have been developed for parameteri......Accurate parameterization of the turbulent exchange of momentum, sensible and latent heat at the surface of the ocean is of fundamental importance for numerical climate prediction and weather forecasting. Based on data from ships and near-shore platforms schemes have been developed...
Geometrical constraints of the synthetic method of estimating fundamental matrix and its analysing
Institute of Scientific and Technical Information of China (English)
沈沛意; 王伟; 吴成柯
1999-01-01
The new geometrical constraints, based on the geometrical analysing of synthetic method, are developed to estimate fundamental matrix (F matrix). Applying the new constraints, the four parameters of fundamental matrix could be estimated firstly, and these four parameters are the coordinates of the two epipoles. The other four parameters of the fundamental matrix could be solved by solving the linear equations with the other new constraint secondly, and these parameters represent the homography between the two pencils of epipolar lines. The synthetic data and the real data are used to test the new method. And the method is of the advantages of obvious geometrical meaning, and high stability of the epipoles of the fundamental matrix.
Design of Broadband Single Fundamental Mode Hollow Core Bragg Fibre
Institute of Scientific and Technical Information of China (English)
LIN Chen-Xi; ZHANG Wei; HUANG Yi-Dong; PENG Jiang-De
2008-01-01
The condition of the single fundamental mode(HE11)transmission in hollow core Bragg fibres is investigated theoretically by the transfer matrix method.The influences of core size and cladding parameters on the single HE11 mode bandwidth are analysed,showing that the maximal bandwidth is more sensirive to the core size than the cladding.The numerical results show that sufficiently broad bandwidth of single HE11 mode transmission can be achieved by proper fibre design.A simple and fast method based on improved hollow metal waveguide model js proposed to optimize fibre structure parameters for the maximal single HE11 mode bandwidth.
DEFF Research Database (Denmark)
Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian;
2011-01-01
of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set...
Ladefoged, Peter
1980-01-01
Summarizes the 16 parameters hypothesized to be necessary and sufficient for linguistic phonetic specifications. Suggests seven parameters affecting tongue shapes, three determining the positions of the lips, one controlling the position of the velum, four varying laryngeal actions, and one controlling respiratory activity. (RL)
Accurate and fast methods to estimate the population mutation rate from error prone sequences
Directory of Open Access Journals (Sweden)
Miyamoto Michael M
2009-08-01
Full Text Available Abstract Background The population mutation rate (θ remains one of the most fundamental parameters in genetics, ecology, and evolutionary biology. However, its accurate estimation can be seriously compromised when working with error prone data such as expressed sequence tags, low coverage draft sequences, and other such unfinished products. This study is premised on the simple idea that a random sequence error due to a chance accident during data collection or recording will be distributed within a population dataset as a singleton (i.e., as a polymorphic site where one sampled sequence exhibits a unique base relative to the common nucleotide of the others. Thus, one can avoid these random errors by ignoring the singletons within a dataset. Results This strategy is implemented under an infinite sites model that focuses on only the internal branches of the sample genealogy where a shared polymorphism can arise (i.e., a variable site where each alternative base is represented by at least two sequences. This approach is first used to derive independently the same new Watterson and Tajima estimators of θ, as recently reported by Achaz 1 for error prone sequences. It is then used to modify the recent, full, maximum-likelihood model of Knudsen and Miyamoto 2, which incorporates various factors for experimental error and design with those for coalescence and mutation. These new methods are all accurate and fast according to evolutionary simulations and analyses of a real complex population dataset for the California seahare. Conclusion In light of these results, we recommend the use of these three new methods for the determination of θ from error prone sequences. In particular, we advocate the new maximum likelihood model as a starting point for the further development of more complex coalescent/mutation models that also account for experimental error and design.
Measuring the chargino parameters
Indian Academy of Sciences (India)
J Kalinowski
2000-07-01
After the supersymmetric particles have been discovered, the priority will be to determine independently the fundamental parameters to reveal the structure of the underlying supersymmetric theory. In my talk I discuss how the chargino sector can be reconstructed completely by measuring the cross-sections with polarized beams at e+e- collider experiments: $\\tilde{X}^{+}_{i}\\tilde{X}^{-}_{j}[i,j=1,2]$. The closure of the two-chargino system can be investigated by analysing sum rules for the production cross-sections.
Fundamental impedance identification method for grid-connected voltage source inverters
DEFF Research Database (Denmark)
Sun, Xiaofeng; Chen, J.; Guerrero, Josep M.
2014-01-01
Considering the importance of line fundamental impedance from the inverter to the point of common coupling (PCC) in microgrids, this study analyses the influence of fundamental impedance on system stability. Line fundamental impedance values not only apply to decoupled droop control, which can...... realise accurate control between active and reactive power, but also regulate the droop coefficient to eliminate system circulation, realise power sharing and improve system stability when a multi-distributed generation system operates in parallel. Moreover, the PCC can sense grid fault on the basis...
Peach, Megan L; Cachau, Raul E; Nicklaus, Marc C
2017-02-24
In this review, we address a fundamental question: What is the range of conformational energies seen in ligands in protein-ligand crystal structures? This value is important biophysically, for better understanding the protein-ligand binding process; and practically, for providing a parameter to be used in many computational drug design methods such as docking and pharmacophore searches. We synthesize a selection of previously reported conflicting results from computational studies of this issue and conclude that high ligand conformational energies really are present in some crystal structures. The main source of disagreement between different analyses appears to be due to divergent treatments of electrostatics and solvation. At the same time, however, for many ligands, a high conformational energy is in error, due to either crystal structure inaccuracies or incorrect determination of the reference state. Aside from simple chemistry mistakes, we argue that crystal structure error may mainly be because of the heuristic weighting of ligand stereochemical restraints relative to the fit of the structure to the electron density. This problem cannot be fixed with improvements to electron density fitting or with simple ligand geometry checks, though better metrics are needed for evaluating ligand and binding site chemistry in addition to geometry during structure refinement. The ultimate solution for accurately determining ligand conformational energies lies in ultrahigh-resolution crystal structures that can be refined without restraints.
Fundamentals of freeze-drying.
Nail, Steven L; Jiang, Shan; Chongprasert, Suchart; Knopp, Shawn A
2002-01-01
--the dominant mechanism of heat transfer in freeze-drying--is inefficient at the pressures used in freeze-drying. Steps should be taken to improve the thermal contact between the product and the shelf of the freeze dryer, such as eliminating metal trays from the drying process. Quantitation of the heat transfer coefficient for the geometry used is a useful way of assessing the impact of changes in the system such as elimination of product trays and changes in the vial. Because heat transfer by conduction through the vapor increases with increasing pressure, the commonly held point of view that "the lower the pressure, the better" is not true with respect to process efficiency. The optimum pressure for a given product is a function of the temperature at which freeze-drying is carried out, and lower pressures are needed at low product temperatures. The controlling resistance to mass transfer is almost always the resistance of the partially dried solids above the submination interface. This resistance can be minimized by avoiding fill volumes of more than about half the volume of the container. The development scientist should also recognize that very high concentrations of solute may not be appropriate for optimum freeze-drying, particularly if the resistance of the dried product layer increases sharply with concentration. Although the last 10 years has seen the publication of a significant body of literature of great value in allowing development scientists and engineers to "work smarter," there is still much work needed in both the science and the technology of freeze-drying. Scientific development is needed for improving analytical methodology for characterization of frozen systems and freeze-dried solids. A better understanding of the relationship between molecular mobility and reactivity is needed to allow accurate prediction of product stability at the intended storage temperature based on accelerated stability at higher temperatures. This requires that the temperature
Fundamental Perspectives on Supply Chain Management
Omta, S.W.F.; Hoenen, S.J.
2012-01-01
The aim of the present literature study is to find the fundamental perspectives/models in the realm of supply chain management and to investigate whether they can be extended based on recent literature findings. The fundamental perspectives were found using a two-tier snowball collection method, inc
Fundamentals of Physics, Student's Solutions Manual
Halliday, David; Resnick, Robert; Walker, Jearl
2000-07-01
No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.
Fundamentals of Physics, 7th Edition
Halliday, David; Resnick, Robert; Walker, Jearl
2004-05-01
No other book on the market today can match the 30-year success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving. This book offers a unique combination of authoritative content and stimulating applications.
Fundamentals of Physics, Problem Supplement No. 1
Halliday, David; Resnick, Robert; Walker, Jearl
2000-05-01
No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.
Individual differences in fundamental social motives.
Neel, Rebecca; Kenrick, Douglas T; White, Andrew Edward; Neuberg, Steven L
2016-06-01
Motivation has long been recognized as an important component of how people both differ from, and are similar to, each other. The current research applies the biologically grounded fundamental social motives framework, which assumes that human motivational systems are functionally shaped to manage the major costs and benefits of social life, to understand individual differences in social motives. Using the Fundamental Social Motives Inventory, we explore the relations among the different fundamental social motives of Self-Protection, Disease Avoidance, Affiliation, Status, Mate Seeking, Mate Retention, and Kin Care; the relationships of the fundamental social motives to other individual difference and personality measures including the Big Five personality traits; the extent to which fundamental social motives are linked to recent life experiences; and the extent to which life history variables (e.g., age, sex, childhood environment) predict individual differences in the fundamental social motives. Results suggest that the fundamental social motives are a powerful lens through which to examine individual differences: They are grounded in theory, have explanatory value beyond that of the Big Five personality traits, and vary meaningfully with a number of life history variables. A fundamental social motives approach provides a generative framework for considering the meaning and implications of individual differences in social motivation. (PsycINFO Database Record
Laboratory Building for Accurate Determination of Plutonium
Institute of Scientific and Technical Information of China (English)
2008-01-01
<正>The accurate determination of plutonium is one of the most important assay techniques of nuclear fuel, also the key of the chemical measurement transfer and the base of the nuclear material balance. An
DNA barcode data accurately assign higher spider taxa
Directory of Open Access Journals (Sweden)
Jonathan A. Coddington
2016-07-01
Full Text Available The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios “barcodes” (whether single or multiple, organelle or nuclear, loci clearly are an increasingly fast and inexpensive method of identification, especially as compared to manual identification of unknowns by increasingly rare expert taxonomists. Because most species on Earth are undescribed, a complete reference database at the species level is impractical in the near term. The question therefore arises whether unidentified species can, using DNA barcodes, be accurately assigned to more inclusive groups such as genera and families—taxonomic ranks of putatively monophyletic groups for which the global inventory is more complete and stable. We used a carefully chosen test library of CO1 sequences from 49 families, 313 genera, and 816 species of spiders to assess the accuracy of genus and family-level assignment. We used BLAST queries of each sequence against the entire library and got the top ten hits. The percent sequence identity was reported from these hits (PIdent, range 75–100%. Accurate assignment of higher taxa (PIdent above which errors totaled less than 5% occurred for genera at PIdent values >95 and families at PIdent values ≥ 91, suggesting these as heuristic thresholds for accurate generic and familial identifications in spiders. Accuracy of identification increases with numbers of species/genus and genera/family in the library; above five genera per family and fifteen species per genus all higher taxon assignments were correct. We propose that using percent sequence identity between conventional barcode sequences may be a feasible and reasonably accurate method to identify animals to family/genus. However
Understanding the Code: keeping accurate records.
Griffith, Richard
2015-10-01
In his continuing series looking at the legal and professional implications of the Nursing and Midwifery Council's revised Code of Conduct, Richard Griffith discusses the elements of accurate record keeping under Standard 10 of the Code. This article considers the importance of accurate record keeping for the safety of patients and protection of district nurses. The legal implications of records are explained along with how district nurses should write records to ensure these legal requirements are met.
Accurate and simple calibration of DLP projector systems
Wilm, Jakob; Olesen, Oline V.; Larsen, Rasmus
2014-03-01
Much work has been devoted to the calibration of optical cameras, and accurate and simple methods are now available which require only a small number of calibration targets. The problem of obtaining these parameters for light projectors has not been studied as extensively and most current methods require a camera and involve feature extraction from a known projected pattern. In this work we present a novel calibration technique for DLP Projector systems based on phase shifting profilometry projection onto a printed calibration target. In contrast to most current methods, the one presented here does not rely on an initial camera calibration, and so does not carry over the error into projector calibration. A radial interpolation scheme is used to convert features coordinates into projector space, thereby allowing for a very accurate procedure. This allows for highly accurate determination of parameters including lens distortion. Our implementation acquires printed planar calibration scenes in less than 1s. This makes our method both fast and convenient. We evaluate our method in terms of reprojection errors and structured light image reconstruction quality.
An accurate metric for the spacetime around neutron stars
Pappas, George
2016-01-01
The problem of having an accurate description of the spacetime around neutron stars is of great astrophysical interest. For astrophysical applications, one needs to have a metric that captures all the properties of the spacetime around a neutron star. Furthermore, an accurate appropriately parameterised metric, i.e., a metric that is given in terms of parameters that are directly related to the physical structure of the neutron star, could be used to solve the inverse problem, which is to infer the properties of the structure of a neutron star from astrophysical observations. In this work we present such an approximate stationary and axisymmetric metric for the exterior of neutron stars, which is constructed using the Ernst formalism and is parameterised by the relativistic multipole moments of the central object. This metric is given in terms of an expansion on the Weyl-Papapetrou coordinates with the multipole moments as free parameters and is shown to be extremely accurate in capturing the physical propert...
Fundamental formulae for wave-energy conversion.
Falnes, Johannes; Kurniawan, Adi
2015-03-01
The time-average wave power that is absorbed from an incident wave by means of a wave-energy conversion (WEC) unit, or by an array of WEC units-i.e. oscillating immersed bodies and/or oscillating water columns (OWCs)-may be mathematically expressed in terms of the WEC units' complex oscillation amplitudes, or in terms of the generated outgoing (diffracted plus radiated) waves, or alternatively, in terms of the radiated waves alone. Following recent controversy, the corresponding three optional expressions are derived, compared and discussed in this paper. They all provide the correct time-average absorbed power. However, only the first-mentioned expression is applicable to quantify the instantaneous absorbed wave power and the associated reactive power. In this connection, new formulae are derived that relate the 'added-mass' matrix, as well as a couple of additional reactive radiation-parameter matrices, to the difference between kinetic energy and potential energy in the water surrounding the immersed oscillating WEC array. Further, a complex collective oscillation amplitude is introduced, which makes it possible to derive, by a very simple algebraic method, various simple expressions for the maximum time-average wave power that may be absorbed by the WEC array. The real-valued time-average absorbed power is illustrated as an axisymmetric paraboloid defined on the complex collective-amplitude plane. This is a simple illustration of the so-called 'fundamental theorem for wave power'. Finally, the paper also presents a new derivation that extends a recently published result on the direction-average maximum absorbed wave power to cases where the WEC array's radiation damping matrix may be singular and where the WEC array may contain OWCs in addition to oscillating bodies.
Machine Learning of Accurate Energy-Conserving Molecular Force Fields
Chmiela, Stefan; Sauceda, Huziel E; Poltavsky, Igor; Schütt, Kristof; Müller, Klaus-Robert
2016-01-01
Using conservation of energy -- a fundamental property of closed classical and quantum mechanical systems -- we develop an efficient gradient-domain machine learning (GDML) approach to construct accurate molecular force fields using a restricted number of samples from ab initio molecular dynamics (AIMD) trajectories. The GDML implementation is able to reproduce global potential-energy surfaces of intermediate-size molecules with an accuracy of 0.3 kcal/mol for energies and 1 kcal/mol/{\\AA} for atomic forces using only 1000 conformational geometries for training. We demonstrate this accuracy for AIMD trajectories of molecules, including benzene, toluene, naphthalene, ethanol, uracil, and aspirin. The challenge of constructing conservative force fields is accomplished in our work by learning in a Hilbert space of vector-valued functions that obey the law of energy conservation. The GDML approach enables quantitative molecular dynamics simulations for molecules at a fraction of cost of explicit AIMD calculations...
Design of Corrugated Plates for Optimal Fundamental Frequency
Directory of Open Access Journals (Sweden)
Nabeel Alshabatat
2016-01-01
Full Text Available This paper investigates shifting the fundamental frequency of plate structures by corrugation. Creating corrugations significantly improves the flexural rigidities of plate and hence increases its natural frequencies. Two types of corrugations are investigated: sinusoidal and trapezoidal corrugations. The finite element method (FEM is used to model the corrugated plates and extract the natural frequencies and mode shapes. The effects of corrugation geometrical parameters on simply supported plate fundamental frequency are studied. To reduce the computation time, the corrugated plates are modeled as orthotropic flat plates with equivalent rigidities. To demonstrate the validity of modeling the corrugated plates as orthotropic flat plates in studying the free vibration characteristics, a comparison between the results of finite element model and equivalent orthotropic models is made. A correspondence between the results of orthotropic models and the FE models is observed. The optimal designs of sinusoidal and trapezoidal corrugated plates are obtained based on a genetic algorithm. The optimization results show that plate corrugations can efficiently maximize plate fundamental frequency. It is found that the trapezoidal corrugation can more efficiently enhance the fundamental frequency of simply supported plate than the sinusoidal corrugation.
Innovation of Methods for Measurement and Modelling of Twisted Pair Parameters
Directory of Open Access Journals (Sweden)
Lukas Cepa
2011-01-01
Full Text Available The goal of this paper is to optimize a measurement methodology for the most accurate broadband modelling of characteristic impedance and other parameters for twisted pairs. Measured values and theirs comparison is presented in this article. Automated measurement facility was implemented at the Department of telecommunication of Faculty of electrical engineering of Czech technical university in Prague. Measurement facility contains RF switches allowing measurements up to 300 MHz or 1GHz. Measured twisted pair’s parameters can be obtained by measurement but for purposes of fundamental characteristics modelling is useful to define functions that model the properties of the twisted pair. Its primary and secondary parameters depend mostly on the frequency. For twisted pair deployment, we are interested in a frequency band range from 1 MHz to 100 MHz.
Constraining the Nordtvedt parameter with the BepiColombo Radioscience experiment
De Marchi, Fabrizio; Milani, Andrea; Schettino, Giulia
2016-01-01
BepiColombo is a joint ESA/JAXA mission to Mercury with challenging objectives regarding geophysics, geodesy and fundamental physics. The Mercury Orbiter Radioscience Experiment (MORE) is one of the on-board experiments, including three different but linked experiments: gravimetry, rotation and relativity. The aim of the relativity experiment is the measurement of the post-Newtonian parameters. Thanks to accurate tracking between Earth and spacecraft, the results are expected to be very precise. However, the outcomes of the experiment strictly depends on our "knowledge" about solar system: ephemerides, number of bodies (planets, satellites and asteroids) and their masses. In this paper we describe a semi-analytic model used to perform a covariance analysis to quantify the effects, on the relativity experiment, due to the uncertainties of solar system bodies parameters. In particular, our attention is focused on the Nordtvedt parameter $\\eta$ used to parametrize the strong equivalence principle violation. Afte...
More-Accurate Model of Flows in Rocket Injectors
Hosangadi, Ashvin; Chenoweth, James; Brinckman, Kevin; Dash, Sanford
2011-01-01
An improved computational model for simulating flows in liquid-propellant injectors in rocket engines has been developed. Models like this one are needed for predicting fluxes of heat in, and performances of, the engines. An important part of predicting performance is predicting fluctuations of temperature, fluctuations of concentrations of chemical species, and effects of turbulence on diffusion of heat and chemical species. Customarily, diffusion effects are represented by parameters known in the art as the Prandtl and Schmidt numbers. Prior formulations include ad hoc assumptions of constant values of these parameters, but these assumptions and, hence, the formulations, are inaccurate for complex flows. In the improved model, these parameters are neither constant nor specified in advance: instead, they are variables obtained as part of the solution. Consequently, this model represents the effects of turbulence on diffusion of heat and chemical species more accurately than prior formulations do, and may enable more-accurate prediction of mixing and flows of heat in rocket-engine combustion chambers. The model has been implemented within CRUNCH CFD, a proprietary computational fluid dynamics (CFD) computer program, and has been tested within that program. The model could also be implemented within other CFD programs.
An Approximate Bayesian Fundamental Frequency Estimator
DEFF Research Database (Denmark)
Nielsen, Jesper Kjær; Christensen, Mads Græsbøll; Jensen, Søren Holdt
2012-01-01
Joint fundamental frequency and model order estimation is an important problem in several applications such as speech and music processing. In this paper, we develop an approximate estimation algorithm of these quantities using Bayesian inference. The inference about the fundamental frequency...... and the model order is based on a probability model which corresponds to a minimum of prior information. From this probability model, we give the exact posterior distributions on the fundamental frequency and the model order, and we also present analytical approximations of these distributions which lower...
Ion beam analysis fundamentals and applications
Nastasi, Michael; Wang, Yongqiang
2015-01-01
Ion Beam Analysis: Fundamentals and Applications explains the basic characteristics of ion beams as applied to the analysis of materials, as well as ion beam analysis (IBA) of art/archaeological objects. It focuses on the fundamentals and applications of ion beam methods of materials characterization.The book explains how ions interact with solids and describes what information can be gained. It starts by covering the fundamentals of ion beam analysis, including kinematics, ion stopping, Rutherford backscattering, channeling, elastic recoil detection, particle induced x-ray emission, and nucle
Manipulating Multistage Interconnection Networks Using Fundamental Arrangements
Directory of Open Access Journals (Sweden)
E. Gur
2010-12-01
Full Text Available Optimizing interconnection networks is a prime object in switching schemes. In this work the authors present a novel approach for obtaining a required channel arrangement in a multi-stage interconnectionnetwork, using a new concept – a fundamental arrangement. The fundamental arrangement is an initial N-1 stage switch arrangement that allows obtaining any required output channel arrangement given an input arrangement, using N/2 binary switches at each stage. The paper demonstrates how a fundamental arrangement can be achieved and how, once this is done, any required arrangement may be obtained within 2(N-1 steps.
The Geometric Nature of the Fundamental Lemma
Nadler, David
2010-01-01
The Fundamental Lemma is a somewhat obscure combinatorial identity introduced by Robert P. Langlands as an ingredient in the theory of automorphic representations. After many years of deep contributions by mathematicians working in representation theory, number theory, algebraic geometry, and algebraic topology, a proof of the Fundamental Lemma was recently completed by Ngo Bau Chau, for which he was awarded a Fields Medal. Our aim here is to touch on some of the beautiful ideas contributing to the Fundamental Lemma and its proof. We highlight the geometric nature of the problem which allows one to attack a question in p-adic analysis with the tools of algebraic geometry.
Modeling of fundamental phenomena in welds
Energy Technology Data Exchange (ETDEWEB)
Zacharia, T.; Vitek, J.M. [Oak Ridge National Lab., TN (United States); Goldak, J.A. [Carleton Univ., Ottawa, Ontario (Canada); DebRoy, T.A. [Pennsylvania State Univ., University Park, PA (United States); Rappaz, M. [Ecole Polytechnique Federale de Lausanne (Switzerland); Bhadeshia, H.K.D.H. [Cambridge Univ. (United Kingdom)
1993-12-31
Recent advances in the mathematical modeling of fundamental phenomena in welds are summarized. State-of-the-art mathematical models, advances in computational techniques, emerging high-performance computers, and experimental validation techniques have provided significant insight into the fundamental factors that control the development of the weldment. The current status and scientific issues in the areas of heat and fluid flow in welds, heat source metal interaction, solidification microstructure, and phase transformations are assessed. Future research areas of major importance for understanding the fundamental phenomena in weld behavior are identified.
Accounting Fundamentals for Non-Accountants
The purpose of this module is to provide an introduction and overview of accounting fundamentals for non-accountants. The module also covers important topics such as communication, internal controls, documentation and recordkeeping.
Fast and Statistically Efficient Fundamental Frequency Estimation
DEFF Research Database (Denmark)
Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom;
2016-01-01
Fundamental frequency estimation is a very important task in many applications involving periodic signals. For computational reasons, fast autocorrelation-based estimation methods are often used despite parametric estimation methods having superior estimation accuracy. However, these parametric m...
Fundamentals of nanoscaled field effect transistors
Chaudhry, Amit
2013-01-01
Fundamentals of Nanoscaled Field Effect Transistors gives comprehensive coverage of the fundamental physical principles and theory behind nanoscale transistors. The specific issues that arise for nanoscale MOSFETs, such as quantum mechanical tunneling and inversion layer quantization, are fully explored. The solutions to these issues, such as high-κ technology, strained-Si technology, alternate devices structures and graphene technology are also given. Some case studies regarding the above issues and solution are also given in the book. In summary, this book: Covers the fundamental principles behind nanoelectronics/microelectronics Includes chapters devoted to solutions tackling the quantum mechanical effects occurring at nanoscale Provides some case studies to understand the issue mathematically Fundamentals of Nanoscaled Field Effect Transistors is an ideal book for researchers and undergraduate and graduate students in the field of microelectronics, nanoelectronics, and electronics.
Language Policy and Planning: Fundamental Issues.
Kaplan, Robert B.
1994-01-01
Fundamental issues in language policy and planning are discussed: language death, language survival, language change, language revival, language shift and expansion, language contact and pidginization or creolization, and literacy development. (Contains 21 references.) (LB)
PRINCIPLES, BASES, AND LAWS OF FUNDAMENTAL INFORMATICS
Directory of Open Access Journals (Sweden)
Gennady N. Zverev
2013-01-01
Full Text Available This paper defines the goals and problems of fundamental informatics, formulates principal laws of information universe and constructive bases of information objects and processes. The classification of semantics types of knowledge and skills is presented.
Accurate tracking control in LOM application
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
The fabrication of accurate prototype from CAD model directly in short time depends on the accurate tracking control and reference trajectory planning in (Laminated Object Manufacture) LOM application. An improvement on contour accuracy is acquired by the introduction of a tracking controller and a trajectory generation policy. A model of the X-Y positioning system of LOM machine is developed as the design basis of tracking controller. The ZPETC (Zero Phase Error Tracking Controller) is used to eliminate single axis following error, thus reduce the contour error. The simulation is developed on a Maltab model based on a retrofitted LOM machine and the satisfied result is acquired.
Accurate studies on dissociation energies of diatomic molecules
Institute of Scientific and Technical Information of China (English)
SUN; WeiGuo; FAN; QunChao
2007-01-01
The molecular dissociation energies of some electronic states of hydride and N2 molecules were studied using a parameter-free analytical formula suggested in this study and the algebraic method (AM) proposed recently. The results show that the accurate AM dissociation energies DeAM agree excellently with experimental dissociation energies Deexpt, and that the dissociation energy of an electronic state such as the 23△g state of 7Li2 whose experimental value is not available can be predicted using the new formula.
Fourth order accurate compact scheme with group velocity control (GVC)
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
For solving complex flow field with multi-scale structure higher order accurate schemes are preferred. Among high order schemes the compact schemes have higher resolving efficiency. When the compact and upwind compact schemes are used to solve aerodynamic problems there are numerical oscillations near the shocks. The reason of oscillation production is because of non-uniform group velocity of wave packets in numerical solutions. For improvement of resolution of the shock a parameter function is introduced in compact scheme to control the group velocity. The newly developed method is simple. It has higher accuracy and less stencil of grid points.
Lasers and optoelectronics fundamentals, devices and applications
Maini, Anil K
2013-01-01
With emphasis on the physical and engineering principles, this book provides a comprehensive and highly accessible treatment of modern lasers and optoelectronics. Divided into four parts, it explains laser fundamentals, types of lasers, laser electronics & optoelectronics, and laser applications, covering each of the topics in their entirety, from basic fundamentals to advanced concepts. Key features include: exploration of technological and application-related aspects of lasers and optoelectronics, detailing both existing and emerging applications in industry, medical diag
Photonic crystal fibers: fundamentals to emerging applications
DEFF Research Database (Denmark)
Bjarklev, Anders Overgaard
2005-01-01
A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers.......A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers....
Institute of Scientific and Technical Information of China (English)
邓足斌; 张振洲
2001-01-01
The SK- i strain gauge parameters testing apparatus presented in this paper is based on the rigid frame bean principle. It is different from those commonly used internationally based on simply spported beams of pure bending moments or cantilever beams of equal strength. According to the two newly proposed concepts, i. e., the shape error of the cylindric surface of the calibration beam and the measurement error of the calibration beam deflection, this paper carries out the error analysis and accuracy evaluation of the apparatus to illustriate the justification of its choice of scheme, and design of structure. It is proven that the SK -1 apparatus is a high accuracy standard apparatus for the implementation of interna- tional Recommendation No. 62 of OIML“The Performance aracteristics of Metallic Resistance Strain Gauges”, and Chi- nese National Standards of Resistance Strain Gauges, GB/T 13992 - 92. Its relative expanded uncertainty has been achieved Ur = 0.11%.%文中提出的SK-1刚架梁式应变计参数测定装置，同目前国际上一般采用简支纯弯矩梁和等强度悬臂梁原理制成的这类装置不一样，沈阳仪器仪表工艺研究所是采用刚架梁原理研制而成的，并按新提出的标定梁园柱面形状误差和标定梁挠度误差两概念[3]，对其进行误差分析和不确定度评定。从而说明该装置的方案，设计思路和精度检定的合理性。为我国电阻应变计(GB/T 13992-92)国家标准和国际电阻应变计行业贯彻实施[OIML]国际建议62号“金属电阻应变计工作特性”提供一种高精度应变计参数的标准装置。它的相对展伸不确定度已达0.1％。
Accurate Switched-Voltage voltage averaging circuit
金光, 一幸; 松本, 寛樹
2006-01-01
Abstract ###This paper proposes an accurate Switched-Voltage (SV) voltage averaging circuit. It is presented ###to compensated for NMOS missmatch error at MOS differential type voltage averaging circuit. ###The proposed circuit consists of a voltage averaging and a SV sample/hold (S/H) circuit. It can ###operate using nonoverlapping three phase clocks. Performance of this circuit is verified by PSpice ###simulations.
Accurate overlaying for mobile augmented reality
Pasman, W; van der Schaaf, A; Lagendijk, RL; Jansen, F.W.
1999-01-01
Mobile augmented reality requires accurate alignment of virtual information with objects visible in the real world. We describe a system for mobile communications to be developed to meet these strict alignment criteria using a combination of computer vision. inertial tracking and low-latency renderi
Fast and spectrally accurate summation of 2-periodic Stokes potentials
Lindbo, Dag
2011-01-01
We derive a Ewald decomposition for the Stokeslet in planar periodicity and a novel PME-type O(N log N) method for the fast evaluation of the resulting sums. The decomposition is the natural 2P counterpart to the classical 3P decomposition by Hasimoto, and is given in an explicit form not found in the literature. Truncation error estimates are provided to aid in selecting parameters. The fast, PME-type, method appears to be the first fast method for computing Stokeslet Ewald sums in planar periodicity, and has three attractive properties: it is spectrally accurate; it uses the minimal amount of memory that a gridded Ewald method can use; and provides clarity regarding numerical errors and how to choose parameters. Analytical and numerical results are give to support this. We explore the practicalities of the proposed method, and survey the computational issues involved in applying it to 2-periodic boundary integral Stokes problems.
Berengut, J C; Kava, E M
2011-01-01
Atomic microwave clocks based on hyperfine transitions, such as the caesium standard, tick with a frequency that is proportional to the magnetic moment of the nucleus. This magnetic moment varies strongly between isotopes of the same atom, while all atomic electron parameters remain the same. Therefore the comparison of two microwave clocks based on different isotopes of the same atom can be used to constrain variation of fundamental constants. In this paper we calculate the neutron and proton contributions to the nuclear magnetic moments, as well as their sensitivity to any potential quark mass variation, in a number of isotopes of experimental interest including 201,199Hg and 87,85Rb, where experiments are underway. We also include a brief treatment of the dependence of the hyperfine transitions to variation in nuclear radius, which in turn is proportional to any change in quark mass. Our calculations of expectation-values of proton and neutron spin in nuclei are also needed to interpret measurements of vio...
Comparison of ultracold neutron sources for fundamental physics measurements
Bison, G; Kirch, K; Lauss, B; Ries, D; Schmidt-Wellenburg, P; Zsigmond, G; Brenner, T; Geltenbort, P; Jenke, T; Zimmer, O; Beck, M; Heil, W; Kahlenberg, J; Karch, J; Ross, K; Eberhardt, K; Geppert, C; Karpuk, S; Reich, T; Siemensen, C; Sobolev, Y; Trautmann, N
2016-01-01
Ultracold neutrons (UCNs) are key for precision studies of fundamental parameters of the neutron and in searches for new CP violating processes or exotic interactions beyond the Standard Model of particle physics. The most prominent example is the search for a permanent electric dipole moment of the neutron (nEDM). We have performed an experimental comparison of the leading UCN sources currently operating. We have used a 'standard' UCN storage bottle with a volume of 32 liters, comparable in size to nEDM experiments, which allows us to compare the UCN density available at a given beam port.
Fundamental U-Theory of Time. Part 1
Directory of Open Access Journals (Sweden)
Yuvraj J. Gopaul
2016-02-01
Full Text Available The Fundamental U-Theory of Time (Part 1 is an original theory that aims to unravel the mystery of what exactly is ‘time’. To date very few explanations, from the branches of physics or cosmology, have succeeded to provide an accurate and comprehensive depiction of time. Most explanations have only managed to provide partial understanding or at best, glimpses of its true nature. The U-Theory uses ‘Thought Experiments’ to uncover the determining characteristics of time. In part 1 of this theory, the focus is not on the mathematics as it is on the accuracy of the depiction of time. Moreover, it challenges current views on theoretical physics, particularly on the idea of ‘time travel’. Notably, it is a theory seeking to present a fresh approach for reviewing Einstein’s Theory of Relativity, while unlocking new pathways for upcoming research in the field of physics and cosmology.
Hydrogen molecular ions for improved determination of fundamental constants
Karr, J -Ph; Koelemeij, Jeroen; Korobov, Vladimir
2016-01-01
The possible use of high-resolution rovibrational spectroscopy of the hydrogen molecular ions H + 2 and HD + for an independent determination of several fundamental constants is analyzed. While these molecules had been proposed for metrology of nuclear-to-electron mass ratios, we show that they are also sensitive to the radii of the proton and deuteron and to the Rydberg constant at the level of the current discrepancies colloquially known as the proton size puzzle. The required level of accuracy, in the 10 --12 range, can be reached both by experiments, using Doppler-free two-photon spectroscopy schemes, and by theoretical predictions. It is shown how the measurement of several well-chosen rovibrational transitions may shed new light on the proton-radius puzzle, provide an alternative accurate determination of the Rydberg constant, and yield new values of the proton-to-electron and deuteron-to-proton mass ratios with one order of magnitude higher precision.
Fundamental Limits of Wideband Localization - Part I: A General Framework
Shen, Yuan
2010-01-01
The availability of positional information is of great importance in many commercial, public safety, and military applications. The coming years will see the emergence of location-aware networks with sub-meter accuracy, relying on accurate range measurements provided by wide bandwidth transmissions. In this two-part paper, we determine the fundamental limits of localization accuracy of wideband wireless networks in harsh multipath environments. We first develop a general framework to characterize the localization accuracy of a given node here and then extend our analysis to cooperative location-aware networks in Part II. In this paper, we characterize localization accuracy in terms of a performance measure called the squared position error bound (SPEB), and introduce the notion of equivalent Fisher information to derive the SPEB in a succinct expression. This methodology provides insights into the essence of the localization problem by unifying localization information from individual anchors and information ...
Accurate measurement of streamwise vortices using dual-plane PIV
Waldman, Rye M.; Breuer, Kenneth S.
2012-11-01
Low Reynolds number aerodynamic experiments with flapping animals (such as bats and small birds) are of particular interest due to their application to micro air vehicles which operate in a similar parameter space. Previous PIV wake measurements described the structures left by bats and birds and provided insight into the time history of their aerodynamic force generation; however, these studies have faced difficulty drawing quantitative conclusions based on said measurements. The highly three-dimensional and unsteady nature of the flows associated with flapping flight are major challenges for accurate measurements. The challenge of animal flight measurements is finding small flow features in a large field of view at high speed with limited laser energy and camera resolution. Cross-stream measurement is further complicated by the predominately out-of-plane flow that requires thick laser sheets and short inter-frame times, which increase noise and measurement uncertainty. Choosing appropriate experimental parameters requires compromise between the spatial and temporal resolution and the dynamic range of the measurement. To explore these challenges, we do a case study on the wake of a fixed wing. The fixed model simplifies the experiment and allows direct measurements of the aerodynamic forces via load cell. We present a detailed analysis of the wake measurements, discuss the criteria for making accurate measurements, and present a solution for making quantitative aerodynamic load measurements behind free-flyers.
Accurate colorimetric feedback for RGB LED clusters
Man, Kwong; Ashdown, Ian
2006-08-01
We present an empirical model of LED emission spectra that is applicable to both InGaN and AlInGaP high-flux LEDs, and which accurately predicts their relative spectral power distributions over a wide range of LED junction temperatures. We further demonstrate with laboratory measurements that changes in LED spectral power distribution with temperature can be accurately predicted with first- or second-order equations. This provides the basis for a real-time colorimetric feedback system for RGB LED clusters that can maintain the chromaticity of white light at constant intensity to within +/-0.003 Δuv over a range of 45 degrees Celsius, and to within 0.01 Δuv when dimmed over an intensity range of 10:1.
Accurate guitar tuning by cochlear implant musicians.
Directory of Open Access Journals (Sweden)
Thomas Lu
Full Text Available Modern cochlear implant (CI users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼ 30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.
Efficient Accurate Context-Sensitive Anomaly Detection
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model,called combined pushdown automaton (CPDA) model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.
On accurate determination of contact angle
Concus, P.; Finn, R.
1992-01-01
Methods are proposed that exploit a microgravity environment to obtain highly accurate measurement of contact angle. These methods, which are based on our earlier mathematical results, do not require detailed measurement of a liquid free-surface, as they incorporate discontinuous or nearly-discontinuous behavior of the liquid bulk in certain container geometries. Physical testing is planned in the forthcoming IML-2 space flight and in related preparatory ground-based experiments.
Accurate guitar tuning by cochlear implant musicians.
Lu, Thomas; Huang, Juan; Zeng, Fan-Gang
2014-01-01
Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.
Synthesizing Accurate Floating-Point Formulas
Ioualalen, Arnault; Martel, Matthieu
2013-01-01
International audience; Many critical embedded systems perform floating-point computations yet their accuracy is difficult to assert and strongly depends on how formulas are written in programs. In this article, we focus on the synthesis of accurate formulas mathematically equal to the original formulas occurring in source codes. In general, an expression may be rewritten in many ways. To avoid any combinatorial explosion, we use an intermediate representation, called APEG, enabling us to rep...
Fundamental Tradeoffs on Green Wireless Networks
Chen, Yan; Xu, Shugong; Li, Geoffrey Ye
2011-01-01
Traditional design of mobile wireless networks mainly focuses on ubiquitous access and large capacity. However, as energy saving and environmental protection become a global demand and inevitable trend, wireless researchers and engineers need to shift their focus to energy-efficiency oriented design, that is, green radio. In this paper, we propose a framework for green radio research and integrate the fundamental issues that are currently scattered. The skeleton of the framework consists of four fundamental tradeoffs: deployment efficiency - energy efficiency tradeoff, spectrum efficiency - energy efficiency tradeoff, bandwidth - power tradeoff, and delay - power tradeoff. With the help of the four fundamental tradeoffs, we demonstrate that key network performance/cost indicators are all stringed together.
Fundamental Concepts in Biophysics Volume 1
Jue, Thomas
2009-01-01
HANDBOOK OF MODERN BIOPHYSICS Series Editor Thomas Jue, PhD Handbook of Modern Biophysics brings current biophysics topics into focus, so that biology, medical, engineering, mathematics, and physical-science students or researchers can learn fundamental concepts and the application of new techniques in addressing biomedical challenges. Chapters explicate the conceptual framework of the physics formalism and illustrate the biomedical applications. With the addition of problem sets, guides to further study, and references, the interested reader can continue to explore independently the ideas presented. Volume I: Fundamental Concepts in Biophysics Editor Thomas Jue, PhD In Fundamental Concepts in Biophysics, prominent professors have established a foundation for the study of biophysics related to the following topics: Mathematical Methods in Biophysics Quantum Mechanics Basic to Biophysical Methods Computational Modeling of Receptor–Ligand Binding and Cellular Signaling Processes Fluorescence Spectroscopy Elec...
Improtance of fundamental study in hydrometallurgy
Majima, Hiroshi
1995-02-01
Recent developments in modeling and optimization studies using computer technology have had a remarkable effect on all areas of extractive metallurgy. However, a lack of fundamental data regarding, for instance, activities, diffusion coefficients, limiting current densities, etc. obstructs the reliable use of this method. In studying hydrometallurgy, I recognized the importance of fundamental analysis and continued such works throughout my university life. For example, activities of water and solutes of the solution systems H2SO4-Mx(SO4)y-H2O and HCl-MClx-H2O were determined, and the results were employed to analyze the dissolution mechanism of metal oxides as well as metal sulfides in those solutions. In this article, fundamental studies mainly made in my laboratory to understand hydrometallurgical phenomena will be discussed.
Accurate structural correlations from maximum likelihood superpositions.
Directory of Open Access Journals (Sweden)
Douglas L Theobald
2008-02-01
Full Text Available The cores of globular proteins are densely packed, resulting in complicated networks of structural interactions. These interactions in turn give rise to dynamic structural correlations over a wide range of time scales. Accurate analysis of these complex correlations is crucial for understanding biomolecular mechanisms and for relating structure to function. Here we report a highly accurate technique for inferring the major modes of structural correlation in macromolecules using likelihood-based statistical analysis of sets of structures. This method is generally applicable to any ensemble of related molecules, including families of nuclear magnetic resonance (NMR models, different crystal forms of a protein, and structural alignments of homologous proteins, as well as molecular dynamics trajectories. Dominant modes of structural correlation are determined using principal components analysis (PCA of the maximum likelihood estimate of the correlation matrix. The correlations we identify are inherently independent of the statistical uncertainty and dynamic heterogeneity associated with the structural coordinates. We additionally present an easily interpretable method ("PCA plots" for displaying these positional correlations by color-coding them onto a macromolecular structure. Maximum likelihood PCA of structural superpositions, and the structural PCA plots that illustrate the results, will facilitate the accurate determination of dynamic structural correlations analyzed in diverse fields of structural biology.
Fundamental studies on the Cs dynamics under ion source conditions
Energy Technology Data Exchange (ETDEWEB)
Friedl, R., E-mail: roland.friedl@physik.uni-augsburg.de; Fantz, U. [AG Experimentelle Plasmaphysik (EPP), Institute of Physics, University of Augsburg, 86135 Augsburg (Germany); Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstraße 2, 85748 Garching (Germany)
2014-02-15
The performance of surface conversion based negative hydrogen ion sources is mainly determined by the caesium dynamics. Therefore, fundamental investigations in vacuum and plasma are performed at a flexible laboratory setup with ion source parameters. Studies on the influence of Cs on the plasma parameters of H{sub 2} and D{sub 2} plasmas showed that n{sub e} and T{sub e} in the bulk plasma are not affected by relevant amounts of Cs and no isotopic differences could be observed. The coating of the vessel surfaces with Cs, however, leads to a considerable gettering of hydrogen atoms from the plasma volume and to the decrease of n{sub e} close to a sample surface due to the formation of negative ions.
Fundamental Vocabulary Selection Based on Word Familiarity
Sato, Hiroshi; Kasahara, Kaname; Kanasugi, Tomoko; Amano, Shigeaki
This paper proposes a new method for selecting fundamental vocabulary. We are presently constructing the Fundamental Vocabulary Knowledge-base of Japanese that contains integrated information on syntax, semantics and pragmatics, for the purposes of advanced natural language processing. This database mainly consists of a lexicon and a treebank: Lexeed (a Japanese Semantic Lexicon) and the Hinoki Treebank. Fundamental vocabulary selection is the first step in the construction of Lexeed. The vocabulary should include sufficient words to describe general concepts for self-expandability, and should not be prohibitively large to construct and maintain. There are two conventional methods for selecting fundamental vocabulary. The first is intuition-based selection by experts. This is the traditional method for making dictionaries. A weak point of this method is that the selection strongly depends on personal intuition. The second is corpus-based selection. This method is superior in objectivity to intuition-based selection, however, it is difficult to compile a sufficiently balanced corpora. We propose a psychologically-motivated selection method that adopts word familiarity as the selection criterion. Word familiarity is a rating that represents the familiarity of a word as a real number ranging from 1 (least familiar) to 7 (most familiar). We determined the word familiarity ratings statistically based on psychological experiments over 32 subjects. We selected about 30,000 words as the fundamental vocabulary, based on a minimum word familiarity threshold of 5. We also evaluated the vocabulary by comparing its word coverage with conventional intuition-based and corpus-based selection over dictionary definition sentences and novels, and demonstrated the superior coverage of our lexicon. Based on this, we conclude that the proposed method is superior to conventional methods for fundamental vocabulary selection.
Fundamental Frequency Tuning and Its Influence on LHC 200MHz ACN Cavity
Linnecar, Trevor Paul R; Tückmantel, Joachim; CERN. Geneva. SPS and LHC Division
2001-01-01
To study the influence of the tuner on the fundamental mode frequency, the Q factor as well as the shunt impedance of the LHC 200MHz ACN cavities, 3D simulations have been done in the frequency domain using MAFIA. Curves giving the variation of RF frequency and other RF parameters with tuner position relative to the inner surface of the cavity have been obtained for the fundamental mode. This paper details the simulation results.
Udayashankar, Paniveni
2016-07-01
I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.
Spaces of fundamental and generalized functions
Gel'Fand, I M
2013-01-01
Spaces of Fundamental and Generalized Functions, Volume 2, analyzes the general theory of linear topological spaces. The basis of the theory of generalized functions is the theory of the so-called countably normed spaces (with compatible norms), their unions (inductive limits), and also of the spaces conjugate to the countably normed ones or their unions. This set of spaces is sufficiently broad on the one hand, and sufficiently convenient for the analyst on the other. The book opens with a chapter that discusses the theory of these spaces. This is followed by separate chapters on fundamental
DOE Fundamentals Handbook: Electrical Science, Volume 3
Energy Technology Data Exchange (ETDEWEB)
1992-06-01
The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.
DOE Fundamentals Handbook: Electrical Science, Volume 2
Energy Technology Data Exchange (ETDEWEB)
1992-06-01
The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.
DOE Fundamentals Handbook: Electrical Science, Volume 4
Energy Technology Data Exchange (ETDEWEB)
1992-06-01
The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive transformers; and electrical test components; batteries; AC and DC voltage regulators; instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.
DOE Fundamentals Handbook: Electrical Science, Volume 1
Energy Technology Data Exchange (ETDEWEB)
1992-06-01
The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.
Fundamentals of Numerical Modelling of Casting Processes
DEFF Research Database (Denmark)
Pryds, Nini; Thorborg, Jesper; Lipinski, Marek;
Fundamentals of Numerical Modelling of Casting Processes comprises a thorough presentation of the basic phenomena that need to be addressed in numerical simulation of casting processes. The main philosophy of the book is to present the topics in view of their physical meaning, whenever possible......, rather than relying strictly on mathematical formalism. The book, aimed both at the researcher and the practicing engineer, as well as the student, is naturally divided into four parts. Part I (Chapters 1-3) introduces the fundamentals of modelling in a 1-dimensional framework. Part II (Chapter 4...
DOE Fundamentals Handbook: Mathematics, Volume 2
Energy Technology Data Exchange (ETDEWEB)
1992-06-01
The Mathematics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mathematics and its application to facility operation. The handbook includes a review of introductory mathematics and the concepts and functional use of algebra, geometry, trigonometry, and calculus. Word problems, equations, calculations, and practical exercises that require the use of each of the mathematical concepts are also presented. This information will provide personnel with a foundation for understanding and performing basic mathematical calculations that are associated with various DOE nuclear facility operations.
Intrinsic Awareness, the Fundamental State of Consciousness
Luo, Weili
2011-01-01
In an effort to simplify the complexity in the studies of consciousness, the author suggests to divide the conscious experiences into a fundamental state, the intrinsic awareness (IA), and functions of this fundamental state. IA does not depend on external environment, our sense organs, and our cognitions. This ground state of consciousness is timeless and irreducible to sub-constituents; therefore reductionism can apply neither to the analysis nor to the new theory of IA. The methodology for investigating IA is proposed and the relation between IA and the hard problem in consciousness proposed by Chalmers is discussed.
Fundamentals and applications of ultrasonic waves
Cheeke, J David N
2002-01-01
Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtually nonexistent.Fundamentals and Applications of Ultrasonic Waves fills that void. Designed specifically for senior undergraduates, beginning graduate students, and those just entering the field, it begins with the fundamentals, but goes well beyond th
Wintucky, Edwin G.; Simons, Rainee N.
2014-01-01
This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler fabricated from two dissimilar waveguides is capable of isolating the power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT). In addition to accurate power measurements at harmonic frequencies, a potential application of the MDC is in the design of a beacon source for atmospheric propagation studies at millimeter-wave frequencies.
Technological Basis and Scientific Returns for Absolutely Accurate Measurements
Dykema, J. A.; Anderson, J.
2011-12-01
The 2006 NRC Decadal Survey fostered a new appreciation for societal objectives as a driving motivation for Earth science. Many high-priority societal objectives are dependent on predictions of weather and climate. These predictions are based on numerical models, which derive from approximate representations of well-founded physics and chemistry on space and timescales appropriate to global and regional prediction. These laws of chemistry and physics in turn have a well-defined quantitative relationship with physical measurement units, provided these measurement units are linked to international measurement standards that are the foundation of contemporary measurement science and standards for engineering and commerce. Without this linkage, measurements have an ambiguous relationship to scientific principles that introduces avoidable uncertainty in analyses, predictions, and improved understanding of the Earth system. Since the improvement of climate and weather prediction is fundamentally dependent on the improvement of the representation of physical processes, measurement systems that reduce the ambiguity between physical truth and observations represent an essential component of a national strategy for understanding and living with the Earth system. This paper examines the technological basis and potential science returns of sensors that make measurements that are quantitatively tied on-orbit to international measurement standards, and thus testable to systematic errors. This measurement strategy provides several distinct benefits. First, because of the quantitative relationship between these international measurement standards and fundamental physical constants, measurements of this type accurately capture the true physical and chemical behavior of the climate system and are not subject to adjustment due to excluded measurement physics or instrumental artifacts. In addition, such measurements can be reproduced by scientists anywhere in the world, at any time
Course Objectives: Electronic Fundamentals, EL16.
Wilson, David H.
The general objective, recommended text, and specific objectives of a course titled "Electronic Fundamentals," as offered at St. Lawrence College of Applied Arts and Technology, are provided. The general objective of the course is "to acquire an understanding of diodes, transistors, and tubes, and so be able to analyze the operation…
Mathematical Fundamentals of Modern Linear Optics
Directory of Open Access Journals (Sweden)
Andrey V. Gitin
2012-01-01
Full Text Available All known quantum-mechanical approaches to wave and statistical optics are united into a single theory, using Feynman's path integral as a fundamental principle. In short-wave approximations, this principle, the Fourier transformations, and concepts of the theory reproduce Fermat's principle, the Legendre transformations, and concepts of Hamilton's optics and radiometry in a one-to-one fashion.
Fundamental Concepts Bridging Education and the Brain
Masson, Steve; Foisy, Lorie-Marlène Brault
2014-01-01
Although a number of papers have already discussed the relevance of brain research for education, the fundamental concepts and discoveries connecting education and the brain have not been systematically reviewed yet. In this paper, four of these concepts are presented and evidence concerning each one is reviewed. First, the concept of…
Workshop on Fundamental Science using Pulsed Power
Energy Technology Data Exchange (ETDEWEB)
Wootton, Alan [Univ. of Texas, Austin, TX (United States)
2016-02-20
The project objective was to fund travel to a workshop organized by the Institute for High Energy Density Science (IHEDS) at the University of Texas at Austin. In so doing the intent was to a) Grow the national academic High Energy Density Science (HEDS) community, b) Expand high impact, discovery driven fundamental HEDS, and c) Facilitate user-oriented research
Fundamental Movement Skills and Autism Spectrum Disorders
Staples, Kerri L.; Reid, Greg
2010-01-01
Delays and deficits may both contribute to atypical development of movement skills by children with ASD. Fundamental movement skills of 25 children with autism spectrum disorders (ASD) (ages 9-12 years) were compared to three typically developing groups using the "Test of Gross Motor Development" ("TGMD-2"). The group matched on chronological age…
The Fundamental Theorems of Interval Analysis
van Emden, M. H.; Moa, B.
2007-01-01
Expressions are not functions. Confusing the two concepts or failing to define the function that is computed by an expression weakens the rigour of interval arithmetic. We give such a definition and continue with the required re-statements and proofs of the fundamental theorems of interval arithmetic and interval analysis. Revision Feb. 10, 2009: added reference to and acknowledgement of P. Taylor.
Uncovering Racial Bias in Nursing Fundamentals Textbooks.
Byrne, Michelle M.
2001-01-01
The portrayal of African Americans in nursing fundamentals textbooks was analyzed, resulting in 11 themes in the areas of history, culture, and physical assessment. Few African American leaders were included, and racial bias and stereotyping were apparent. Differences were often discussed using Eurocentric norms, and language tended to minimize…
Fundamental problems in fault detection and identification
DEFF Research Database (Denmark)
Saberi, Ali; Stoorvogel, Anton A.; Sannuti, Peddapullaiah;
1999-01-01
For certain fundamental problems in fault detection and identification, the necessary and sufficient conditions for their solvability are derived. These conditions are weaker than the ones found in the literature, since we do not assume any particular structure for the residual generator...
Solar Energy: Solar System Design Fundamentals.
Knapp, Henry H., III
This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…
The Fundamental Equation in Tourism Finance
M.J. McAleer (Michael)
2015-01-01
textabstractThe purpose of the paper is to present the fundamental equation in tourism finance that connects tourism research to empirical finance and financial econometrics. The energy industry, which includes, oil, gas and bio-energy fuels, together with the tourism industry, are two of the most i
Euler and the Fundamental Theorem of Algebra.
Duham, William
1991-01-01
The complexity of the proof of the Fundamental Theorem of Algebra makes it inaccessible to lower level students. Described are more understandable attempts of proving the theorem and a historical account of Euler's efforts that relates the progression of the mathematical process used and indicates some of the pitfalls encountered. (MDH)
Why quarks cannot be fundamental particles
Kalman, C S
2005-01-01
Many reasons why quarks should be considered composite particles are found in the book Preons by D'Souza and Kalman. One reason not found in the book is that all the quarks except for the u quark decay. The electron and the electron neutrino do not decay. A model of fundamental particles based upon the weak charge is presented.
Fundamental and Gradient Differences in Language Development
Herschensohn, Julia
2009-01-01
This article reexamines Bley-Vroman's original (1990) and evolved fundamental difference hypothesis that argues that differences in path and endstate of first language acquisition and adult foreign language learning result from differences in the acquisition procedure (i.e., language faculty and cognitive strategies, respectively). The evolved…
Fundamental Composite Higgs Dynamics on the Lattice
DEFF Research Database (Denmark)
Hietanen, Ari; Lewis, Randy; Pica, Claudio;
2014-01-01
In reference [1] a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics was proposed. In the unified framework the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson o...
Fundamentals of space business and economics
Gurtuna, Ozgur
2013-01-01
This book provides an overview of key topics related to space business and management. Case studies and an integrative section are included to illustrate the fundamental concepts and to build intuition. Key topics in the field, such as risk management and cost management, are covered in detail.
Photovoltaic Solar Energy - From Fundamentals to Applications
Reinders, A.H.M.E.; Verlinden, P.J.; Sark, W.G.J.H.M.; Freundlich, A.
2017-01-01
Solar PV is now the third most important renewable energy source, after hydro and wind power, in terms of global installed capacity. Bringing together the expertise of international PV specialists Photovoltaic Solar Energy: From Fundamentals to Applications provides a comprehensive and up-to-date ac
Singular boundary method using time-dependent fundamental solution for scalar wave equations
Chen, Wen; Li, Junpu; Fu, Zhuojia
2016-11-01
This study makes the first attempt to extend the meshless boundary-discretization singular boundary method (SBM) with time-dependent fundamental solution to two-dimensional and three-dimensional scalar wave equation upon Dirichlet boundary condition. The two empirical formulas are also proposed to determine the source intensity factors. In 2D problems, the fundamental solution integrating along with time is applied. In 3D problems, a time-successive evaluation approach without complicated mathematical transform is proposed. Numerical investigations show that the present SBM methodology produces the accurate results for 2D and 3D time-dependent wave problems with varied velocities c and wave numbers k.
Accurate measurement of unsteady state fluid temperature
Jaremkiewicz, Magdalena
2017-03-01
In this paper, two accurate methods for determining the transient fluid temperature were presented. Measurements were conducted for boiling water since its temperature is known. At the beginning the thermometers are at the ambient temperature and next they are immediately immersed into saturated water. The measurements were carried out with two thermometers of different construction but with the same housing outer diameter equal to 15 mm. One of them is a K-type industrial thermometer widely available commercially. The temperature indicated by the thermometer was corrected considering the thermometers as the first or second order inertia devices. The new design of a thermometer was proposed and also used to measure the temperature of boiling water. Its characteristic feature is a cylinder-shaped housing with the sheath thermocouple located in its center. The temperature of the fluid was determined based on measurements taken in the axis of the solid cylindrical element (housing) using the inverse space marching method. Measurements of the transient temperature of the air flowing through the wind tunnel using the same thermometers were also carried out. The proposed measurement technique provides more accurate results compared with measurements using industrial thermometers in conjunction with simple temperature correction using the inertial thermometer model of the first or second order. By comparing the results, it was demonstrated that the new thermometer allows obtaining the fluid temperature much faster and with higher accuracy in comparison to the industrial thermometer. Accurate measurements of the fast changing fluid temperature are possible due to the low inertia thermometer and fast space marching method applied for solving the inverse heat conduction problem.
DEFF Research Database (Denmark)
Chon, K H; Cohen, R J; Holstein-Rathlou, N H
1997-01-01
A linear and nonlinear autoregressive moving average (ARMA) identification algorithm is developed for modeling time series data. The algorithm uses Laguerre expansion of kernals (LEK) to estimate Volterra-Wiener kernals. However, instead of estimating linear and nonlinear system dynamics via moving...... average models, as is the case for the Volterra-Wiener analysis, we propose an ARMA model-based approach. The proposed algorithm is essentially the same as LEK, but this algorithm is extended to include past values of the output as well. Thus, all of the advantages associated with using the Laguerre...... function remain with our algorithm; but, by extending the algorithm to the linear and nonlinear ARMA model, a significant reduction in the number of Laguerre functions can be made, compared with the Volterra-Wiener approach. This translates into a more compact system representation and makes...
Are accurate equation of state parameters important in Richtmyer-Meshkov instabilities?
Energy Technology Data Exchange (ETDEWEB)
Cloutman, L D
1999-08-01
The Richtmyer-Meshkov instability is a classical fluid dynamical instability that has been extensively studied to help understand turbulent mixing. A recent numerical simulation of a shock tube experiment with an air-SF6 interface and a weak shock (Mach 1.2) used the ideal gas equation of state for air and an artificially low temperature as a surrogate for the correct SF6 gas physics. We have run a similar problem with both the correct gas physics and three versions of the air surrogate to understand the errors thereby introduced. We find that for the weakly driven single-mode case considered here, the instability amplitude is not affected, the interface location is affected only slightly, but the thermodynamic states are quite different. This result is not surprising because the flow far from the shock waves is essentially incompressible.
Are accurate equation of state parameters important in Richtmyer-Meshkov instabilities
Energy Technology Data Exchange (ETDEWEB)
Cloutman, L D
1999-08-01
The Richtmyer-Meshkov instability is a classical fluid dynamical instability that has been extensively studied to help understand turbulent mixing. A recent numerical simulation of a shock tube experiment with an air-SF6 interface and a weak shock (Mach 1.2) used the ideal gas equation of state for air and an artificially low temperature as a surrogate for the correct SF6 gas physics. We have run a similar problem with both the correct gas physics and three versions of the air surrogate to understand the errors thereby introduced. We find that for the weakly driven single-mode case considered here, the instability amplitude is not affected, the interface location is affected only slightly, but the thermodynamic states are quite different. This result is not surprising because the flow far from the shock waves is essentially incompressible.
Niche Genetic Algorithm with Accurate Optimization Performance
Institute of Scientific and Technical Information of China (English)
LIU Jian-hua; YAN De-kun
2005-01-01
Based on crowding mechanism, a novel niche genetic algorithm was proposed which can record evolutionary direction dynamically during evolution. After evolution, the solutions's precision can be greatly improved by means of the local searching along the recorded direction. Simulation shows that this algorithm can not only keep population diversity but also find accurate solutions. Although using this method has to take more time compared with the standard GA, it is really worth applying to some cases that have to meet a demand for high solution precision.
Accurate estimation of indoor travel times
DEFF Research Database (Denmark)
Prentow, Thor Siiger; Blunck, Henrik; Stisen, Allan
2014-01-01
the InTraTime method for accurately estimating indoor travel times via mining of historical and real-time indoor position traces. The method learns during operation both travel routes, travel times and their respective likelihood---both for routes traveled as well as for sub-routes thereof. In...... are collected within the building complex. Results indicate that InTraTime is superior with respect to metrics such as deployment cost, maintenance cost and estimation accuracy, yielding an average deviation from actual travel times of 11.7 %. This accuracy was achieved despite using a minimal-effort setup...
Accurate diagnosis is essential for amebiasis
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
@@ Amebiasis is one of the three most common causes of death from parasitic disease, and Entamoeba histolytica is the most widely distributed parasites in the world. Particularly, Entamoeba histolytica infection in the developing countries is a significant health problem in amebiasis-endemic areas with a significant impact on infant mortality[1]. In recent years a world wide increase in the number of patients with amebiasis has refocused attention on this important infection. On the other hand, improving the quality of parasitological methods and widespread use of accurate tecniques have improved our knowledge about the disease.
The first accurate description of an aurora
Schröder, Wilfried
2006-12-01
As technology has advanced, the scientific study of auroral phenomena has increased by leaps and bounds. A look back at the earliest descriptions of aurorae offers an interesting look into how medieval scholars viewed the subjects that we study.Although there are earlier fragmentary references in the literature, the first accurate description of the aurora borealis appears to be that published by the German Catholic scholar Konrad von Megenberg (1309-1374) in his book Das Buch der Natur (The Book of Nature). The book was written between 1349 and 1350.