Miracle-dz/UniFAR-FTUs huggingface dataset:
Recent star formation in interacting galaxies - II. Super starbursts in merging galaxies.

Contrairement au cas des Seyfert, les proprietes radio, IR et optiques des objets resultant du fusionnement ne revelent pas de source centrale compacte non thermique, et peuvent etre interpretees grâce a un sursaut de formation stellaire d'intensite et d'etendue spatiale extraordinaires: ce sont les «super sursauts stellaires». On suggere qu'ils se produisent au cours de la plupart des fusionnements
A Study of Work-Time Distributions on Unpaced Tasks

Abstract Recent investigations into the work-time distributions of light assembly tasks indicate that some reserve must be used when applying the generalized relationships which are traditionally believed to hold. Video recordings were made of industrial operations and, in subsequent analysis, any process controlled or nonproductive elements were excluded. The elements studied were all analyzed using MTM-1 so that the nature of the element and the method used to perform it could be defined closely. The work time distributions obtained show the general pattern expected in regard to positive skewness and gross measures of dispersion. However, measures of skewness and the coefficient of variation show wide differences throughout the overall sample. Analysis of the nature of the individual work elements and their statistical characteristics failed to reveal any clear explanation for the differences encountered. The need for further research in this area is, therefore, underlined where the prediction of the na.
Autoregressive model selection based on a prediction perspective

The autoregressive (AR) model is a popular method for fitting and prediction in analyzing time-dependent data, where selecting an accurate model among considered orders is a crucial issue. Two commonly used selection criteria are the Akaike information criterion and the Bayesian information criterion. However, the two criteria are known to suffer potential problems regarding overfit and underfit, respectively. Therefore, using them would perform well in some situations, but poorly in others. In this paper, we propose a new criterion in terms of the prediction perspective based on the concept of generalized degrees of freedom for AR model selection. We derive an approximately unbiased estimator of mean-squared prediction errors based on a data perturbation technique for selecting the order parameter, where the estimation uncertainty involved in a modeling procedure is considered. Some numerical experiments are performed to illustrate the superiority of the proposed method over some commonly used order selection criteria. Finally, the methodology is applied to a real data example to predict the weekly rate of return on the stock price of Taiwan Semiconductor Manufacturing Company and the results indicate that the proposed method is satisfactory.
Mechanics of the Metal Cutting Process. I. Orthogonal Cutting and a Type 2 Chip

An analysis of the chip geometry and the force system found in the case of orthogonal cutting accompanied by a type 2 chip has yielded a collection of useful equations which make possible the study of actual machining operations in terms of basic mechanical quantities. The shearing strain undergone by the metal during chip formation, and the velocities of shear and of chip flow are among the geometrical quantities which can be quantitatively determined. The force relationships permit calculation of such quantities as the various significant force components, stresses, the coefficient of friction between chip and cutting tool, and the work done in shearing the metal and in overcoming friction on the tool face. The experimental methods by which such analyses can be readily made are described. Observed and calculated values from typical tests are presented.
Harmonic quintessence and the derivation of the charge and mass of the electron and the proton and quark masses

Both the charge and mass of the electron are empirically known to a great degree of accuracy. Similarly the constants such as the mass of the proton and the neutron are known to a good degree of accuracy. However, currently none of these constants can be derived from first principles, and their inter-relationship remains obscure. In this paper, harmonic quintessence is used to derive the charge and mass of the electron. Importantly, from here it is also possible to further derive the mass of the proton, neutron and quarks from first principles, using harmonic quintessence.
Properties of H II region populations in galaxies. II. The H II region luminosity function

H-alpha emission-line fluxes have been measured for all of the detected H II regions in 30 nearby spiral and irregular galaxies, and these data are used to study the behavior of the H II region luminosity functions (LFs). In most galaxies, the LF is well represented by a power law function. Both the normalization and the shape of the LF change systematically with Hubble type. Early-type spirals possess fewer H II regions of all luminosities, a steeper LF, and in many cases an upper cutoff or turnover in the LF. Taken together, these effects account for the virtual absence of 'supergiant' H II regions such as 30 Doradus in Sa-Sb galaxies. Most of the massive stars in late-type spiral and irregular galaxies form in large H II/OB complexes, while in early-type spirals the bulk of the massive star formation occurs in small regions ionized by no more than a few OB stars. 59 references.
A Perturbation Expansion for Diffusion in a Random Velocity Field

We present a formal perturbation expansion for the large scale effective drift velocity and diffusion matrix of a medium with stationary random velocity, $V(x)$, and constant nonrandom diffusion matrix, a, on a small scale. If $\mu $ denotes the mean of $V(x)$, and we express $V(x)$ as $\mu + \varepsilon U(x)$, then the expansion is in powers of $\varepsilon $ with $\mu $, U and a fixed. We obtain explicit expressions up to second order in $\varepsilon $ which generalize the standard formulae to the case $a \ne 0$.
Numerical Simulation on Retrieval of Meso-γ Scale Precipitable Water Vapor Distribution with the Quasi-Zenith Satellite System (QZSS)

A simulation study was conducted to investigate the retrieval of meso-γ scale precipitable water vapor (PWV) distribution with the Quasi-Zenith Satellite System (QZSS) using output from a non-hydrostatic model (JMA NHM). The evaluation was performed on PWV values obtained by simulating three different methods: using all GPS satellites above an elevation angle higher than 10° (PWVG) (conventional Global Navigation Satellite System (GNSS) meteorology method), using only the QZSS satellite at the highest elevation (PWVQ), and using only the GPS satellite at the highest elevation (PWVHG). The three methods were compared by assuming the vertically integrated water vapor amounts of the model as true PWV. As a result, the root mean square errors of PWVG, PWVQ, and PWVHG were 2.78, 0.13, and 0.59 mm, respectively, 5 min before the rainfall. The time series of PWVHG had a large discontinuity (~ 2 mm) when the GPS satellite with the highest elevation changed, while that of PWVQ was small because the elevation at which the highest QZSS satellites change was much higher. The standard deviation of PWVQ was smaller than those of PWVG and PWVHG, which vary significantly depending on GPS satellite geometry. When the spatial distributions of PWVG and PWVQ were compared to the meso-γ scale distribution of the reference PWV, PWVG smoothed out the PWV fluctuations, whereas PWVQ captured them well, due to the higher spatial resolution achievable using only high-elevation slant paths. These results suggest that meso-γ scale water vapor fluc tuations associated with a thunderstorm can be retrieved using a dense GNSS receiver network and analyzing PWV from a single high-elevation GNSS satellite. In this study, we focus on QZSS, since this constellation would be especially promising in this context, and it would provide nearly continuous PWV observations as its highest satellite changes, contrary to using the highest satellites from multiple GNSS constellations.
Individual solutions to shared problems create a modern tragedy of the commons

Introducing individual solutions to shared problems can lead to costly coordination failure and a “modern tragedy of the commons. ” Alone and together, climatic changes, population growth, and economic scarcity create shared problems that can be tackled effectively through cooperation and coordination. Perhaps because cooperation is fragile and easily breaks down, societies also provide individual solutions to shared problems, such as privatized healthcare or retirement planning. But how does the availability of individual solutions affect free-riding and the efficient creation of public goods? We confronted groups of individuals with a shared problem that could be solved either individually or collectively. Across different cost-benefit ratios of individually versus collectively solving the shared problem, individuals display a remarkable tendency toward group-independent, individual solutions. This “individualism” leads to inefficient resource allocations and coordination failure. Introducing peer punishment further results in wasteful punishment feuds between “individualists” and “collectivists. ” In the presence of individual solutions to shared problems, groups struggle to balance self-reliance and collective efficiency, leading to a “modern tragedy of the commons. ”
Threshold segmentation using cultural algorithms for image analysis

The image segmentation is often an important step in the analysis of images. In this paper, an image segmentation method based on cultural algorithms is presented. The method performs the image segmentation by selecting the optimal threshold values. The multi-threshold values are used. First of all, an entropy function corresponding to an image is defined. The optimal threshold values are obtained by making the entropy function reach the maximal value. Secondly, an algorithm based on the principle of cultural algorithms is presented for the computation of the optimal thresholds. The algorithm consists of three major components: a population space, a belief space, and a communication protocol that describes how knowledge is exchanged between the first two components. The designs and implementations of the three components are given in detail. The experimental results show that the segmentation method proposed in this paper can obtain the near optimal threshold for image segmentation.
Changes of solar luminosity and radius following secular perturbations in the convective envelope

The effect on solar models of several types of slow, spherically symmetric perturbations, acting at various depths within the convective envelope, are calculated. Results are presented on perturbations of the efficiency of convective energy transport (alpha perturbations) and on changes in the nongas component of pressure (beta perturbations). The effects of magnetic fields concentrated near the interface between the radiative core and the convective envelope are explored. It is found that the response and relaxation diagnostics depend both on the type of perturbation and on the depth at which the perturbation is applied. In addition to the general depth dependence, model behavior is sensitive to the presence of major ionization zones near the perturbed layer. The time dependence of the solar model behavior is characterized by an initial hydrostatic reaction followed by a thermal readjustment on a time scale of about 100 years, and finally relaxation to a new thermal equilibrium on a Kelvin time scale.
HOPF BIFURCATION OF TIME-DELAY LIENARD EQUATIONS

The linearized stability and Hopf bifurcation of the delay Lienard equations are studied. The linearized asymptotic stability for the null solution of the equations with two parameters is analyzed. The Hopf bifurcation and the stability of periodic solutions are investigated by constructing the center manifold and using the normal form method. Several examples for typical nonlinear delay Lienard equations are given to show the coincidence between the theoretical analysis and the numerical results.
Black holes in binary stellar systems and galactic nuclei

In the last , following pioneering papers by Ya B Zeldovich and E E Salpeter, in which a powerful energy release from nonspherical accretion of matter onto a black hole (BH) was predicted, many observational studies of black holes in the Universe have been carried out. To date, the masses of several dozen stellar-mass black holes in X-ray binary systems and of several hundred supermassive black holes in galactic nuclei have been measured. The estimated radii of these massive and compact objects do not exceed several gravitational radii. For about ten stellar-mass black holes and several dozen supermassive black holes, the values of the dimensionless angular momentum have been estimated, which, in agreement with theoretical predictions, do not exceed the limiting value of . A new field of astrophysics, so-called black hole demography, which studies the birth and growth of black holes and their evolutionary connection to other objects in the Universe, namely stars, galaxies, etc., is rapidly developing. In addition to supermassive black holes, massive stellar clusters are observed in galactic nuclei, and their evolution is distinct from that of supermassive black holes. The evolutionary relations between supermassive black holes in galactic centers and spheroidal stellar components (bulges) of galaxies, as well as dark-matter galactic haloes are brought out. The launch into Earth's orbit of the space radio interferometer RadioAstron opened up the real possibility of finally proving that numerous discovered massive and highly compact objects with properties very similar to those of black holes make up real black holes in the sense of Albert Einstein's General Relativity. Similar proofs of the existence of black holes in the Universe can be obtained by intercontinental radio interferometry at short wavelengths (the international program, Event Horizon Telescope).
Design of efficient organic tandem cells: On the interplay between molecular absorption and layer sequence

We have carried out detailed optical simulations of tandem solar cells based on the following organic semiconductors: poly(3-hexylthiophene) (P3HT), poly[2,6-(4,4-bis-(2-ethylhexyl)-4H- cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT), 1-(3- methoxycarbonyl) propyl-1-phenyl[6,6] C61 (PC60BM), and 1-(3-methoxycarbonyl) propyl-1- phenyl[6,6] C71 (PC70BM). We demonstrate that out of the many possible combinations of the component materials, one specific combination emerges as the best to reduce the spectral overlap of the two bulk heterojunction blends and thereby to ensure an optimized short-circuit current density (Jsc). Furthermore, the calculations allow us to predict the maximum Jsc achievable in tandem cells based on P3HT and PCPDTBT. Finally, we show that the efficient tandem cell realized and described recently by Kim et al. [Science 317, 222 (2007)] ensures balanced absorption in the top and bottoms cells.
Optimal placement of piezoelectric actuators on plate structures for active vibration control using genetic algorithm

The present work considers the optimal placement of piezoelectric actuators on a thin plate using integer coded genetic algorithm. The fitness function reflects on the controllability index which is the singular values decomposition of a control matrix. The index measures the input energy required to achieve the desired structural control using piezoelectric actuators. The LQR (Linear Quadratic Regulator) optimal control scheme has been applied to study the control effectiveness. It is observed that the frequency responses of cantilever obtained from finite element code hold good in agreement with the experimental results. Numerical simulations revealed that optimal locations obtained by integer coded GA based on controllability index with LQR controller offers effective control as compared non-optimal locations.
Low resistance, high dynamic range reconfigurable phase change switch for radio frequency applications

A GeTe reconfigurable phase change switch for radio frequency applications is presented. Low ON state resistance (180 Ω) and large dynamic range (7×103 X) were achieved through low resistance electrode design and high current. A partial crystallization and partial reamorphization model is proposed to explain the differences between the measured and calculated device ON (set) and OFF (reset) state resistances, respectively. The dependency between ON state resistance and reset current was estimated using a first order thermal design in steady state which suggests lower reset current by choosing materials of lower melting temperature and structures with better thermal isolation.
Direct evidence for prolonged magnetic reconnection at a continuous x‐line within the heliospheric current sheet

Observations by 5 spacecraft of an exceptionally broad (1.85 × 106 km) Petschek‐type reconnection exhaust within the heliospheric current sheet, HCS, in the solar wind at 1 AU on 31 August and 1 September 2001 provide convincing direct evidence for prolonged (at least 5 hours) magnetic reconnection at a continuous X‐line in the solar wind. At least 1.2 × 1024 ergs of magnetic energy were extracted from the HCS in this event and converted to kinetic and thermal energy of the exhaust plasma. The reconnection produced field lines disconnected from the Sun and may have originated inside the point where the solar wind became super‐Alfvénic, thereby slightly reducing the amount of open magnetic flux present in the heliosphere.
Arrangement of cells in vegetable tissues

The authors study the arrangement of cells in undifferentiated vegetable tissues of five different species. The distribution of the number of sides, the average area (an), perimeter (pn) and side length (ln) of n-sided cells are determined as well as the correlation between the number of sides of a cell and of its neighbours. The results show that vegetable cellular nets obey Aboav-Weaire's law. They also discuss Lewis' law and a possible relation between (pn) and n. The analysis of these structures provides a different example of random cellular structures and helps to show general aspects of the ideal one.
Unified Theory on Power Laws for Flow Resistance

Two general power formulas, one for hydraulically smooth flows and the other for fully rough flows, are derived in a rational way from the widely accepted logarithmic formulas for the velocity profile and the Darcy-Weisbach friction factor. A regression analysis based on the method of least squares is used to determine the valid range of the local velocity (or normal distance from the wall) in the power formula. Some older empirical formulas, such as Lacey’s, Manning’s, Blasius’, and Hazen-Williams’, and their valid ranges, are actually explained analytically by the results. Incomplete self-similarity of the power law, in which the exponent and the associated coefficient vary with the similarity parameters, such as the Reynolds number and the relative roughness, is elucidated through the parametric representations of the power formulas and their counterparts based on the logarithmic law. This paper examines the concept and rationale behind the power formulation of uniform turbulent shear flows, thereby addressing some critical issues in the modeling of flow resistance based on the power law.
Photobleaching of photodarkening in ytterbium doped aluminosilicate fibers with 633 nm irradiation

In the present study, we examined photodarkening loss reduction in Yb3+ doped aluminosilicate fibers by utilizing 633 nm light irradiation. It is demonstrated that the final photobleaching value is intensity dependent, but the percentage of photodarkening reduction does not depend on dopant concentrations for settled bleaching intensity. Further examination was committed to explore the photobleaching starting from different photodarkening loss levels while keeping the same dopant concentration and subsequently the other way around. This approach related photobleaching with the number of photodarkening induced color centers and also showed that photobleaching was dopant concentration dependent. In all experiments an unbleachable residual loss for the bleaching powers up to ~100 W/mm2 was found. To the best of our knowledge this is the most extensive investigation of photobleaching effect.
Data Mining and Knowledge Discovery Via Statistical Mechanics in Nonlinear Stochastic Systems

A modern calculus of multivariate nonlinear multiplicative Gaussian-Markovian systems provides models of many complex systems faithful to their nature, e.g., by not prematurely applying quasi-linear approximations for the sole purpose of easing analysis. To handle these complex algebraic constructs, sophisticated numerical tools have been developed, e.g., methods of adaptive simulated annealing (ASA) global optimization and of path integration (PATHINT). In-depth application to three quite different complex systems have yielded some insights into the benefits to be obtained by application of these algorithms and tools, in statistical mechanical descriptions of neocortex (short-term memory and electroencephalography), financial markets (interest-rate and trading models), and combat analysis (baselining simulations to exercise data).
Kinetic effects of magnetic turbulence in tokamaks

The electron kinetic theory of tokamak plasmas in the presence of magnetic turbulence is investigated. The evolution of the electron distribution function under the effect of turbulent magnetic fields, a DC electric field and Couloumb collisions is governed by a 3-D kinetic equation (2-D in velocity space and 1-D in ordinary space). The turbulence is described by a radial diffusion operator, coupled to slowing down in energy due to ambipolar fields. The resulting kinetic equation is solved numerically by means of a new fully 3-D Fokker-Planck code. It is shown that in a turbulent plasma the central equilibrium electron distribution function is nearly Maxwellian, but in the temperature gradient region an anisotropic superthermal tail develops owing to radial diffusion of hot electrons. This affects the local electrical conductivity and the global plasma resistance. An analytical expression of this turbulent electrical conductivity is derived
An Error-Bound Theorem for Approximate Markov Chains

Recently an error-bound theorem was reported to conclude analytic error bounds for approximate Markov chains. The theorem required a uniform bound for marginal expectations of the approximate model. This note will relax this bound to steady state rather than marginal expectations as of practical interest (i) to simplify verification and/or (ii) to obtain a more accurate error bound. A communication model is studied in detail to support the results.
On local tomography

In this paper we explain how the local tomography approach to tomographic problems can be extended to a wide range of situations including limited data problems, attenuated transforms, and generalized radon transforms. Numerical examples illustrate the use of local tomography applied to complete and limited data problems. Our analytic results are obtained through the use of microlocal analysis.
The B factor in multilayer thermionic refrigeration

The figure of merit for multilayer thermionic refrigeration is discussed in terms of an effective B factor, which has a similar definition as the B factor in thermoelectrics. We show that high efficiencies for cooling or power generation are only obtained with very high values of this B factor. Such high values can only be attained because of the low thermal conductivity of multilayers. The B factor for thermionics is usually less than the one for thermoelectrics.