Miracle-dz/UniFAR-FTUs huggingface dataset:
N‐Words and Negative Concord

5 The possibility of having an existential polarity item under negation 5.1 Negative concord versus existential dependencies: locality 5.1. 1 N-words in islands 5.1. 2 N-words in embedded clauses 5.1. 3 Preceding negation 5.2 Existential polarity items and the semantics of n-words 5.2. 1 Almost/absolutely modification 5.2. 2 ke’and’ modification 5.2. 3 Donkey anaphora 5.2. 4 Use in predicate nominals 5. 3 Summary
A new tunable laser using a single electroabsorption tuning super structure grating for subnanosecond switching applications

A new tunable laser structure using a single electroabsorption (EA) tuning super structure grating (SSG) section for fast wavelength switching operation is reported. Instead of index change by carrier density or by thermal variation, the tuning mechanism of this absorption change (AC) distributed Bragg reflector (DBR) InGaAsP strained QW laser is based on a localized absorption variation induced in a Franz-Keldysh EA SSG section used as Bragg reflector. According to a simulation which takes into account the absorption and refractive index variations of the SSG section versus voltage and wavelength, an optimized device theoretically allows a wide tuning range of up to 11 nm with nine regularly spaced wavelength channels. Over this whole tuning range, the variation of the AC-DBR laser threshold gain is lower than 2 cm/sup -1/. Compared to a standard DBR laser exhibiting an 8-cm/sup -1/ threshold gain variation for the same wavelength shift, this AC-DBR laser would present extremely low threshold current and emitted power variations under tuning. Owing to its tuning mechanism, the switching time of the AC-DBR laser is independent of the wavelength shift, and only limited by the parasitic capacitance of the SSG ridge section. A test structure, easier to realize, with only a theoretical tuning range of 3 nm over four regularly spaced channels has been fabricated. These devices exhibiting a tuning range of 2.5 nm with three modes, present threshold current and output power variations under tuning of less than 8 mA and 1.2 dB, respectively. A switching time between two successive wavelength channels shorter than 250 ps has been observed, in agreement with typical capacitances of 0.8 pF/100 /spl mu/m measured on the SSG section.
Production cross sections and the particle stability of proton-rich nuclei from Ni-58 fragmentation

Using a primary beam of [sup 58]Ni at 650 MeV/nucleon impinging on a beryllium target, production cross sections of proton-rich fragments from projectile fragmentation have been measured at the projectile-fragment separator FRS at Gesellschaft fuer Schwerionenforschung Darmstadt m.b. H. The experimental data ranging from nickel to scandium for isotopes close to stability as well as for fragments at the proton drip line are compared to predictions of the microscopic ISApace code, to calculations with a revised abrasion-ablation model and with the statistical abrasion model, and to the results of the empirical parametrization EPAX. Besides these systematic measurements, evidence for the particle stability of [sup 50]Ni has been found for the first time, whereas the nuclei [sup 49]Co and [sup 54]Cu are shown to be unbound. These observations are compared to mass predictions.
Feedforward-plus-sliding mode controller design with experimental application of coupled tank system

In this paper, a feedforward-plus-sliding mode controller is proposed. The combination uses a feedforward controller to achieve predefined process output and the sliding mode controller is combined to assure the robustness despite uncertainty, nonlinear dynamics, and external disturbances. The effectiveness of proposed method is shown by simulations on nonlinear models of a coupled tanks system and then validated by performing a real-time experiment on the system. The studies show the improved setpoint tracking of the proposed controller compared with the classical PI controller.
A ROSAT PSPC catalogue of X-ray sources in the LMC region

We analyzed more than 200 ROSAT PSPC observations in a 10 by 10 degree field centered on the Large Magellanic Cloud (LMC) and performed between 1990 and 1994 to derive a catalogue of X-ray sources. The list contains 758 sources with their X-ray properties. From cross-correlations of the PSPC catalogue with the SIMBAD data base and literature searches we give likely identifications for 144 X-ray sources based on positional coincidence, but taking into account X-ray properties like hardness ratios and source extent. 46 known sources are associated with supernova remnants (SNRs) and candidates in the LMC, most of them already detected by previous X-ray missions. Including the new candidates from Haberl & Pietsch (1999) based on variability studies of the sources in our PSPC catalogue, the number of X-ray binaries in the LMC increased to 17 and that of the supersoft sources (SSSs) to 9. The remaining ~50% of the identified sources comprise mainly foreground stars (up to 57) and background extragalactic objects (up to 15). The often distinguished X-ray properties of the different source types were used for a first classification of new, unknown X-ray sources. Eight new PSPC sources are classified as SNRs from their hardness ratios and one promising new SNR candidate with extended X-ray emission is found further north than all known SNRs. Three soft X-ray sources have hardness ratios compatible to those of the known SSSs. A selection on hardness ratios and X-ray to optical flux ratio further suggests 27 foreground stars and 3 AGN.
An Infrared Photometric Study of Galaxies with Extragalactic H2O Maser Sources

All galaxies with extragalactic H2O maser sources observed so far are collected. With the 2MASS and the IRAS photometric data an infrared study is performed on those galaxies. By a comparison between the H2O maser detected sources and non-detected sources in the infrared it is indicated that infrared properties in the IRAS 12–25 μm and 60–100 μm are important for producing H2O masers in galaxies. It is also found that the H2O maser galaxies with different nuclear activity types have rather different infrared properties mainly in the IRAS 12–60 μm region.
Elastic surface waves

Devices that exploit the properties of elastic surface waves can perform very complex signal‐processing functions, identical to those carried out by conventional electromagnetic devices. The great advantage to using surface waves instead of electromagnetic waves is the tremendous reduction in size of surface‐wave devices compared to their electromagnetic counterparts. This great reduction in size is the result of the great difference between the elastic and electromagnetic velocities. Surface waves propagate at velocities approximately 105 times slower than electromagnetic velocities; thus, at the same frequency, the elastic wavelength is 105 times shorter than the electromagnetic wavelength. A further advantage is that the energy in the elastic surface wave can readily be sensed anywhere along its path.
Long-term photometry of blazars at Abastumani Observatory

Abstract We give a brief summary of the ongoing Abastumani Active Galactic Nuclei Monitoring Program started in the May 1997. More than 110000 frames are obtained during more than 1300 nights of observations for about 50 target objects, among them gamma-ray, X-ray and optical blazars. All observations were done in the BVRI bands using ST-6 CCD based photometer attached to the Newtonian focus of 70-cm meniscus telescope.
Application of spectral collocation method to a class of nonlinear PDEs

In this paper approximate solutions to a class of nonlinear partial differential equations by means of the Chebyshev spectral collocation method is considered. First, properties of the Chebyshev spectral collocation method required for our subsequent development are given and utilized to reduce the computation of Fisher's, generalized Burger's-Fisher, generalized Huxley, and generalized Burger's-Huxley equations to some system of ordinary differential equations. Then, we use fourth-order Runge-Kutta formula for the numerical solution of the system of ordinary differential equations. The method is applied to a few test examples to illustrate the accuracy and the implementation of the method.
Laser diodes with integrated spot-size transformer as low-cost optical transmitter elements for telecommunications

We have realized laser diodes with integrated spot-size transformer to achieve a high-coupling efficiency to a standard single-mode fiber (SMF) without microoptical elements. A coupling loss of about 1 dB has been achieved with tolerances of 12 /spl mu/m in both vertical and horizontal direction. We have fabricated both distributed-feedback (DFB) and Fabry-Perot (FP)-type lasers. In the case of the FP lasers the longitudinal single-mode emission was stabilized by means of an external fiber Bragg-grating which was directly butt-coupled to the laser. We have experimentally and theoretically investigated the optical and electrical properties of the devices using a transmission line model.
Electro-optic response of chromophores in a viscoelastic polymer matrix to a combined dc and ac poling field

We present a generalized model for the electro-optic response of chromophores in a viscoelastic polymer matrix to a combined dc and ac applied poling field. The model includes a local molecular field of random orientation at each chromophore site to take into account the influence of the polymer matrix on the chromophore reorientation. Hence the model relies on a physically intuitive picture of chromophore dynamics in a viscoelastic polymer matrix. The dynamics is described by the rotational diffusion equation, where the local molecular field is inferred and a solution is presented with a variational approach. We obtain an analytical expression for the electro-optic response both at the modulating frequency and at two times the modulating frequency, having explicit frequency and molecular-field dependence. The model is successfully compared with frequency-resolved ellipsometric measurements in an azo-dye containing polymer guest–host system that is poled in a combined dc and ac electric field. The experimental setup is a modified Teng–Man ellipsometer in a balanced detection scheme, and, as a model system for investigating the electro-optic response, we use the chromophore Disperse Red 1 in a polymer matrix of poly(methyl methacrylate). Finally, the model is compared with independent experiments on a 2,5-dimethyl-4-(p-nitrophenylazo)-anisole containing photorefractive polymer composite, and good qualitative agreement is found.
Perturbation Methods in Derivatives Pricing under Stochastic Volatility

This work employs perturbation techniques to price and hedge financial derivatives in a stochastic volatility framework. Fouque et al. [44] model volatility as a function of two processes operating on different time-scales. One process is responsible for the fast-fluctuating feature of volatility and corresponds to the slow time-scale and the second is for slowfluctuations or fast time-scale. The former is an Ergodic Markov process and the latter is a strong solution to a Lipschitz stochastic differential equation. This work mainly involves modelling, analysis and estimation techniques, exploiting the concept of mean reversion of volatility. The approach used is robust in the sense that it does not assume a specific volatility model. Using singular and regular perturbation techniques on the resulting PDE a first-order price correction to Black-Scholes option pricing model is derived. Vital groupings of market parameters are identified and their estimation from market data is extremely efficient and stable. The implied volatility is expressed as a linear (affine) function of log-moneyness-tomaturity ratio, and can be easily calibrated by estimating the grouped market parameters from the observed implied volatility surface. Importantly, the same grouped parameters can be used to price other complex derivatives beyond the European and American options, which include Barrier, Asian, Basket and Forward options. However, this semi-analytic perturbative approach is effective for longer maturities and unstable when pricing is done close to maturity. As a result a more accurate technique, the decomposition pricing approach that gives explicit analytic firstand second-order pricing and implied volatility formulae is discussed as one of the current alternatives. Here, the method is only employed for European options but an extension to other options could be an idea for further research. The only requirements for this method are integrability and regularity of the stochastic volatility process. Corrections to [3] remarkable work are discussed here. ii Stellenbosch University http://scholar.sun.ac.za
Distribution fast decoupled state estimation by measurement pairing

A three-phase fast decoupled state estimation method is presented for distribution systems. The weighted least square (WLS) approach is used. A current-based formulation is discussed first and then the decoupled version. The proposed method produces a constant symmetric gain matrix which can be decoupled into two identical sub-gain matrices. The method offers good performance in handling the distribution system and is many times faster than other formulations, especially for large systems. An observability test is discussed.
Numerical computation of the back-focal plane interference pattern by a spherical scatterer under a focused Gaussian beam

Three-dimensional position of optically trapped dielectric particles can be detected by measuring the back-focal plane interference pattern of incident and scattered fields. Time-domain surface current based near zone to far zone transformation was implemented to compute the interference pattern by a spherical scatterer under a focused Gaussian beam. Computed results are compared with experimental data for validations.
Nuclear-Spin Induced Electron Spin Decoherence In Semiconductor Quantum dots

In this thesis we consider fundamental problems in relation to the development of a quantum computer. Early on, it was postulated by researchers like Feynman and Deutsch that only a computer obeying quantum mechanical laws of physics would be efficient enough to simulate any physical system. Since then much effort has been made to build devices that would allow to coherently control a quantum two-level system or qubit (quantum bit), which is the quantum counterpart of a classical bit. Although remarkable achievements have been made towards the ultimate goal of having a functional quantum computer, there are still several obstacles that must be overcome. One of these is decoherence induced via the interaction of the quantum two-level system with its environment. Here, we focus on spin-based quantum computing. It was proposed to confine electrons in electrically defined quantum dots and use their spin, a natural quantum two-level system, to encode information. One of the major problems with this approach is that if the quantum dot is made out of III-V semiconductor materials, like GaAs (as it is often the case in experimental implementations), then the spin of the electron interacts with the host nuclear spins via hyperfine interactions. This undesirable interaction leads to fast loss of coherence of the spin system turning it into a mere classical system. However, the situation is not as hopeless as it appears, since it is possible to increase coherence times by manipulating nuclear spins. In chapter 2, we study a nuclear-state preparation scheme that increases the coherence time of a two-spin qubit in a double quantum dot. The twoelectron system is tuned repeatedly across a singlet-triplet level-anticrossing
The Geospace Modeling Program Grand Challenge

The first Geospace Modeling Program (GEM) campaign, the boundary layer campaign, focused on the cusp, the dayside magnetopause, and dayside magnetospheric boundary layers. One of the projects pursued during this campaign was a construction of synoptic maps of convective flows and particle regions within the polar ionosphere for different orientations of the interplanetary magnetic field. In 1996, the GEM steering committee recommended that these synoptic maps be used for data-model comparisons to provide tests of model convection patterns, convection strengths, separatrix locations, boundary layers, and currents. The papers that follow this introductory paper describe results of the data-model comparisons. This paper summarizes the data analysis approach and the results that were obtained that are important for the comparisons.
NUMERICAL METHOD FOR THE PREDICTION OF INCOMPRESSIBLE FLOW AND HEAT TRANSFER IN DOMAINS WITH SPECIFIED PRESSURE BOUNDARY CONDITIONS

A variety of engineering applications involve incompressible flows in devices for which boundary pressures are known. The purpose of this article is to present a mathematical formulation and a computational method for the prediction of incompressible flow in domains with specified pressure boundaries. The computational treatment of specified pressure boundaries in complex geometries is presented within the framework of a nonstaggered technique based on curvilinear boundary-fitted grids. The construction of the discretization equations for unknown velocities on specified pressure boundaries and the solution of the discretization equations using the SIMPLE algorithm are discussed. The proposed method is applied for predicting incompressible forced flows in branched ducts and in buoyancy-driven flows. These examples illustrate the utility of the proposed method in predicting incompressible flows with specified boundary pressures encountered in practical applications.
Investigating the allegations of Indian nuclear test preparations in the Rajasthan Desert

This paper describes how commercial satellite imagery was used along with news reports and published scientific articles to investigate the December 1995 allegations of Indian nuclear test preparations in the Rajasthan Desert. Taking the allegations against India as an example of a future CTB compliance dispute, the investigation was conducted to test the utility of commercial satellite imagery for CTB verification. The technical inquiry produced a series of findings on India`s nuclear testing history and on the recent nuclear test allegations. These findings included the exact location of the subsidence crater created by the May 18, 1974 nuclear test, the discovery of an adjacent military range near Khetolai village, and the observation of recent large-scale, unusual activity at this military range in the immediate vicinity of the 1974 test site. The image-derived information was used to sift fact from fiction in the conflicting media reports. It was then integrated into the collection of credible evidence and analyzed to determine whether the observed activity at the Khetolai military range was conventional, missile testing, nuclear, or innocuous. 95 refs., 1 tab.
Simulated annealing band selection approach for hyperspectral imagery

In hyperspectral imagery, greedy modular eigenspace (GME) was developed by clustering highly correlated bands into a smaller subset based on the greedy algorithm. Unfortunately, GME is hard to find the optimal set by greedy scheme except by exhaustive iteration. The long execution time has been the major drawback in practice. Accordingly, finding the optimal (or near-optimal) solution is very expensive. Instead of adopting the band-subset-selection paradigm underlying this approach, we introduce a simulated annealing band selection (SABS) approach, which takes sets of non-correlated bands for high-dimensional remote sensing images based on a heuristic optimization algorithm, to overcome this disadvantage. It utilizes the inherent separability of different classes embedded in high-dimensional data sets to reduce dimensionality and formulate the optimal or near-optimal GME feature. Our proposed SABS scheme has a number of merits. Unlike traditional principal component analysis, it avoids the bias problems that arise from transforming the information into linear combinations of bands. SABS can not only speed up the procedure to simultaneously select the most significant features according to the simulated annealing optimization scheme to find GME sets, but also further extend the convergence abilities in the solution space based on simulated annealing method to reach the global optimal or near-optimal solution and escape from local minima. The effectiveness of the proposed SABS is evaluated by NASA MODIS/ASTER (MASTER) airborne simulator data sets and airborne synthetic aperture radar images for land cover classification during the Pacrim II campaign. The performance of our proposed SABS is validated by supervised k-nearest neighbor classifier. The experimental results show that SABS is an effective technique of band subset selection and can be used as an alternative to the existing dimensionality reduction method.
Turbulent resistivity in wavy two-dimensional magnetohydrodynamic turbulence

The theory of turbulent resistivity in ‘wavy’ magnetohydrodynamic turbulence in two dimensions is presented. The goal is to explore the theory of quenching of turbulent resistivity in a regime for which the mean field theory can be rigorously constructed at large magnetic Reynolds number Rm. This is achieved by extending the simple two-dimensional problem to include body forces, such as buoyancy or the Coriolis force, which convert large-scale eddies into weakly interacting dispersive waves. The turbulence-driven spatial flux of magnetic potential is calculated to fourth order in wave slope – the same order to which one usually works in wave kinetics. However, spatial transport, rather than spectral transfer, is the object here. Remarkably, adding an additional restoring force to the already tightly constrained system of high Rm magnetohydrodynamic turbulence in two dimensions can actually increase the turbulent resistivity, by admitting a spatial flux of magnetic potential which is not quenched at large Rm, although it is restricted by the conditions of applicability of weak turbulence theory. The absence of Rm-dependent quenching in this wave-interaction-driven flux is a consequence of the presence of irreversibility due to resonant nonlinear three-wave interactions, which are independent of collisional resistivity. The broader implications of this result for the theory of mean field electrodynamics are discussed.
Femtosecond LIBS studies of nitropyrazoles

We present our initial experimental results from the LIBS studies of pyrazole, 1-nitropyrazole, 3-nitropyrazole, 3,4- dinitropyrazole and 1-methyl- 3,4,5 trinitro pyrazole recorded with femtosecond pulses and performed in argon atmosphere. CN molecular bands in three different spectral regions of 357 nm-360 nm, 384 nm-389 nm and 414 nm -423 nm, C2 swan bands near 460 nm-475 nm, 510 nm– 520 nm and 550 nm-565 nm were observed. The C peak at 247.82 nm, H peak at 656.2 nm have also been observed along with several peaks of O and N. CN/C2, CN/C, C2/C and C2/N ratios were measured from the average of 25 spectra obtained in argon. The effect of number of nitro groups on the atomic and molecular emission has been evaluated. A gate delay of 100 ns and a gate width of 800 ns were used for collecting the spectra.
Quadratic Matrix Equations

Necessary and sufficient conditions for the matrix equation XAX = B and for the n system of matrix equations XAX = B, 2 CijXD;j = K,, i=l,2, . ,m, to be solvable are proven in this paper. If solvable, all solutions of the equation or system are determined. These results are used to obtain particular solutions of the general quadratic matrix equation XAX+BX + XC = D.