Miracle-dz/UniFAR-FTUs huggingface dataset:
Another Look at the Influence of Absorbing Aerosols in Drops on Cloud Absorption: Large Aerosols

Abstract Since as early as 1969, solar absorbing aerosols inside of cloud drops have been suggested to influence cloud radiative properties. The absorbing aerosols were invoked to help explain two “anomalies”: 1) the maximum visible albedo of thick stratocumulus clouds is observed to be only 0.7–0.8, rather than close to 1.0 as would be expected from pure water clouds, and 2) the total solar cloud forcing ratio is observed to be near 1.5 for a wide range of clouds, rather than near 1.0 as would be expected from pure water clouds. While subsequent studies refuting absorbing aerosols have been limited to certain aerosol and cloud drop size ranges, in this study the authors explore the potential radiative effects of supermicron dust and soot aerosols in cloud drops, which can have especially high absorption cross sections. Because of the lack of measurements and limited microphysical simulations of such supermicron absorbing aerosols, it is not suggested that the calculations will entirely resolve the two an.
Mathematics for the Captured Student.

S. K. Stein, Professor of Mathematics at the University of California at Davis, is a Governor of the MAA. His primary research interests are algebra, combinatorics, and convex bodies. At the two-year college level, he has written texts on algebra, geometry, and most recently calculus and analytic geometry. Twice a week he teaches fractions to fourth graders, "to find where and how the confusion originates. "
Evaluation of Forecast Performance of Asian Summer Monsoon Low-Level Winds Using the TIGGE Dataset

AbstractThe forecast performances of the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM) by six THORPEX Interactive Grand Global Ensemble (TIGGE) centers during the summers of 2008–13 were evaluated to reflect the current predictability of state-of-the-art numerical weather prediction. The results show that the EASM is overestimated by all TIGGE centers except the Canadian Meteorological Centre (CMC). The SASM is overestimated by the European Centre for Medium-Range Weather Forecasts (ECMWF), the China Meteorological Administration (CMA), and the CMC, but is underpredicted by the Japan Meteorological Agency (JMA). Additionally, the SASM is overestimated for early lead times and underestimated for longer lead times by the National Centers for Environmental Prediction (NCEP) and the Met Office (UKMO). Further analysis suggests that such biases are likely associated with land–sea thermal contrasts. The EASM surge is overestimated by the NCEP and CMA and mainly underestimated by the oth.
The Gemini Planet Imager: integration and status

The Gemini Planet Imager is a next-generation instrument for the direct detection and characterization of young warm exoplanets, designed to be an order of magnitude more sensitive than existing facilities. It combines a 1700-actuator adaptive optics system, an apodized-pupil Lyot coronagraph, a precision interferometric infrared wavefront sensor, and a integral field spectrograph. All hardware and software subsystems are now complete and undergoing integration and test at UC Santa Cruz. We will present test results on each subsystem and the results of end-to-end testing. In laboratory testing, GPI has achieved a raw contrast (without post-processing) of 10-6 5σ at 0.4”, and with multiwavelength speckle suppression, 2x10-7 at the same separation.
The total cross section for electron scattering by atomic hydrogen

The authors attempt to construct an accurate total cross section for e--H(1s) scattering in the intermediate energy range from 1.0 to 3.7 Ryd by adding together the best cross sections for elastic scattering, bound-state excitation and ionization that are presently available. For elastic scattering and n=2 excitation they have used the theoretical cross sections arising from intermediate energy R-matrix (IERM) calculations, for n=3 excitation experimental results have been implemented, while for excitation to n=4 and above an extrapolation procedure has been employed. For the ionization component the experimental cross section has been adopted. The constructed total cross section is found to be in very good agreement with the IERM theoretical total cross section obtained by applying the optical theorem to their elastic scattering amplitude. In addition, the authors have examined the accuracy with which the ionization cross section might be extracted from the total cross sections given the available knowledge about bound-state excitation cross sections.
Linear Precoding for Channel Orthogonalization with Reduced Restriction about Antenna Assignment in Multiuser MIMO-OFDM

In downlink multiuser multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems, a base station (BS) communicates with multiple user terminals (UTs) simultaneously using MIMO transmission. Since UTs each receive signals intended for other UTs in addition to those intended for themselves, they suffer from multiuser interference (MUI). To eliminate MUI, the use of block diagonalization (BD) has been proposed. BD is a scheme of channel inversion that divides a multiuser MIMO channel into multiple single-user MIMO channels by transmitter-side linear precoding. However, BD has two restrictions about the antenna assignment to be able to calculate the precoding weight matrix. In this paper, we propose another linear precoding scheme for MUI elimination. Our proposed scheme is released from one of two restrictions in calculating the precoding weight matrix for MUI elimination. Simulation results show that the proposed scheme and BD achieve the same bit error rate (BER) performance under the same antenna assignment. Furthermore, we can show that the proposed precoding scheme eliminates MUI even under antenna assignments which are impracticable with BD and that the principle of the proposed scheme is applied to uplink multiuser MIMO–OFDM systems.
Bundled aluminum hollow-core fibers for delivery of ultraviolet laser beams

A bundle of aluminum hollow-core fibers is used to deliver ArF-excimer-laser light. The hollow cores are purged by a simple gas injection system to prevent the generation of ozone gas. For a 1-m-long bundle that is composed of 40 fibers each with an inner diameter of 0.7 mm, the straight loss is about 1.2 dB. The bundle also offers advantages of easy beam coupling and a high damage threshold.
Electron-Optical Systems with Helical Axis

As the chromatic error of focus has the same sign in all electron lenses with straight axis, achromatic combinations do not exist. It is shown, however, that systems with curved axes can be designed which are equivalent to centred systems in the gaussian approximation, but have chromatic error of opposite sign, and thus may be useful as correcting elements. Systems with a helical axis, with a helical electrostatic field so shaped as to eliminate first-order astigmatism, have particular advantages In such systems images of unit magnification are produced at equal intervals along the helical axis. Under certain conditions the transverse chromatic shift can be made zero in every second, or third,. image, while the longitudinal error of focus can be given any negative value by suitable choice of the pitch. Such systems may find application in secondary emission and dark-field electron microscopes, and particularly in diffraction microscopy. At a certain pitch the chromatic error becomes infinite. This system is particularly easily realized by means of two coaxial cylindrical electrodes. It is useless as a chromatic corrector, but may find applications as a velocity spectrograph.
Terminal sliding mode control of second‐order nonlinear uncertain systems

In this paper, a terminal sliding mode control scheme is proposed for second-order nonlinear uncertain systems. By using a function augmented sliding hyperplane, it is guaranteed that the output tracking error converges to zero in finite time which can be set arbitrarily. In addition, the proposed scheme eliminates the reaching phase problem so that the closed-loop system always shows the invariance property to parameter uncertainties. Copyright © 1999 John Wiley & Sons, Ltd.
Experimental and numerical study of supersonic film cooling

An experimental study has been performed at ONERA to simulate film cooling in a rocket engine. Two injector heights and cold and ambient temperature films, as well as matched and under- and overexpanded films, have heen investigated. The mixing process has been documented by measuring the Mach number and temperature profiles. In addition, wall pressure and temperature, as well as heat transfer coefficients, have been measured. A boundary-layer code has been used to compute this flow. To achieve a fair prediction of the flow, several turbulence models, including compressibility corrections, have been tested. The prediction of the mixing-layer expansion is crucial for the quality of the computational results
A Finite Volume Extension of the Lax-Friedrichs and Nessyahu-Tadmor Schemes for Conservation Laws on Unstructured Grids

The non-oscillatory central difference scheme of Nessyahu and Tadmor, in which the resolution or Riemann problems at the cell interfaces is by-passed thanks to the use of the staggered Lax-Friedrichs scheme, is extended here to a two-step, two-dimensional non-oscillatory centered scheme in finite volume formulation. The construction of the scheme rests on a finite volume extension of the Lax-Friedrichs scheme, in which the finite volume cells are the barycentric cells constructed around the nodes of an FEM triangulation, for odd time steps, and some quadrilateral cells associated with this triangulation, for even time steps. Piecewise linear cell interpolants using least-squares gradients combined with a van Leer-type slope limiting allow for an oscillation-free second-order resolution. Some preliminary numerical experiments suggest that two-dimensional problems can be handled very efficiently by the method presented here.
Two-Timescale-Integration Method for Inverse Simulation

The integrationmethodis extensivelyappliedin the inverse simulationofaircraftmotionwhere control inputsare determined once a maneuver or  ight task is assigned. In many circumstances the presence of multiple timescales and right half-plane transmission zeros in aircraft dynamics introduces problems of accuracy and stability in the numerical algorithm. This paper presents a formulation for inverse simulation problems where the concept of timescale separation ismerged into an integration technique and a constrained optimizationmethod. Two subscale problems are solved separately for the slow and fast timescales and a numerical algorithm is devised that presents signi cant advantages in terms of numerical ef ciency and robustness. The technique accounts for the issue of control saturation and lends itself to applications where the aircraft trajectory is given as a function of time. The results of the study show the improved performances of the technique in comparison with an integration method that is based on the local optimization concept.
Effect of Interaural Correlation on the Precision of Centering a Noise

Subjects were asked to center a noise presented via earphones, by adjusting a delay line controlling interaural time differences. Various noise correlations were employed ranging from 1.00 to 0.10. Even in the latter case, which represents a signal to noise difference of −9.5 dB the subjects were able to perform well above a chance level.
Experimental Study and Genetic-Algorithm-Based Correlation on Shell-Side Heat Transfer and Flow Performance of Three Different Types of Shell-and-Tube Heat Exchangers

The heat transfer and pressure drop of three types of shell-and-tube heat exchangers, one with conventional segmental baffles and the other two with continuous helical baffles, were experimentally measured with water flowing in the tube side and oil flowing in the shell side. The genetic algorithm has been used to determine the coefficients of correlations. It is shown that under the identical mass flow, a heat exchanger with continuous helical baffles offers higher heat transfer coefficients and pressure drop than that of a heat exchanger with segmental baffles, while the shell structure of the side-in-side-out model offers better performance than that of the middle-in-middle-out model. The predicted heat transfer rates and friction factors by means of the genetic algorithm provide a closer fit to experimental data than those determined by regression analysis. The predicted corrections of heat transfer and flow performance in the shell sides may be used in engineering applications and comprehensive study. It is recommended that the genetic algorithm can be used to handle more complicated problems and to obtain the optimal correlations.
A Flexible Simple Thermostat for Small Objects and the Range of 100 to 400 K

A flexible, inexpensive thermostat for the temperature range 100 to 400 K is described. Liquid nitrogen is the coolant and a gas serves as transfer medium. The temperature can be set to better than 1 K and is held there within ½ K by an electronic control system. The relatively small working volume of the order of 10 cm3 allows quick changes of temperature, a desirable feature in typical semiconductor experiments.
Silicon nanophotonic integrated devices enabling multiplexed on-chip optical interconnects

Advanced multiplexing technologies including wavelength-division-multiplexing (WDM), polarization-division multiplexing (PDM), and mode-division multiplexing (MDM) have been utilized as a cost-effective solution to enhance the capacity of an optical-interconnect link. The on-chip (de)multiplexers, including WDM filters, PDM devices, and MDM devices, are the most important key components in a multi-channel multiplexed optical interconnect system. Hybrid (de)multiplexer to enable various multiplexing technologies simultaneously are becoming more and more important to achieve many channels. In this paper we give a review for our recent work on silicon photonic integrated devices for realizing multi-channel multiplexed on-chip optical interconnects.
Subdwarf ultraviolet excesses and metal abundances

The relation between stellar ultraviolet excesses and abundances is reexamined with the aid of new data, and an investigation is made of the accuracy of previous abundance analyses. A high-resolution echellogram of the subdwarf HD 201891 is analyzed to illustrate some of the problems. Generally, the earliest and latest analytical techniques yield consistent results for dwarfs. New UBV data yield normalized ultraviolet excesses, delta (U-B)/sub 0.6/, which are compared to abundances to produce a graphical relation that may be used to estimate (Fe/H) to +- 0.2 dex, given UBV colors accurate to +- 0.01 mag. The relation suggests a possible discontinuity between the halo and old-disk stars.
Optimum performance analysis of an irreversible quantum cryogenic refrigeration cycle working with an ideal Bose or Fermi gas

An irreversible model of the Carnot cryogenic refrigeration cycle working with an ideal Bose or Fermi gas is established, which is composed of two irreversible adiabatic and two isothermal processes. The effects of the quantum degeneracy of the working substance, the irreversibility of the finite-rate heat transfer between the working fluid and the heat reservoirs, and the internal irreversibility in two adiabatic processes on the optimum performance characteristics of the quantum refrigeration cycle are analyzed. The performance characteristics of the cycle in strong and weak gas degeneracy cases are discussed. Expressions for several important performance parameters such as the coefficient of performance, cooling rate and power input are derived. By using numerical solutions, the cooling rate of the cycle is optimized for a given power input. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal regions of the coefficient of performance and power input are determined. Some optimum criteria are given.
A perturbation finite element method for modeling moving conductive and magnetic regions without remeshing

Purpose – To develop a sub‐domain perturbation technique for efficiently modeling moving systems in magnetodynamics with a magnetic field h‐conform finite element (FE) formulation.Design/methodology/approach – A reference problem is first solved in a global mesh excluding some moving regions and thus avoiding the inclusion of their meshes. Its solution gives the sources for a sequence of perturbation problems with the supplementary moving magnetic and conductive regions. Each of these sub‐problems requires an appropriate proper volume mesh of the associated moving region and its surrounding region, with no need of interconnection. The solutions are transferred from one problem to the other through projections of source fields between meshes.Findings – The consideration of sub‐problems and associated sources, in a sequence of perturbation problems, leads to a significant speed‐up of the repetitive solutions in analyses of moving systems. A free movement in any direction can be considered with no need of re.
Dim target detection based on nonlinear multifeature fusion by Karhunen-Loeve transform

Dim target detection and tracking is a key technique for imaging tracking systems and is a challenging and leading-edge subject. A new strategy for dim target detection is presented. Various nonlinear features that are representative of dim targets are extracted from image sequences. Then, an information fusion algorithm by Karhunen-Loeve (K-L) transform is used to obtain an integrated feature. As a correlation degree, using an integrated feature calculates a target's position coordinates. Experimental results demonstrate the proposed method is feasible and effective. (C) 2004 Society of Photo-Optical Instrumentation Engineers.
Analysis of structural and chemical features of CdHgSe nanocrystals via resonance Raman spectroscopy

We investigate quantum dots (QDs) of ternary compounds CdXHg1-XSe with 0<X<1 using a Raman scattering technique at room temperature. We obtained the correlation between QDs chemical composition and the frequencies of CdSe-like LO and the HgSe-like TO and LO modes. It is shown that the crystalline structure of original CdSe QDs used for Cd/Hg substitution, either zinc blende or wurtzite affects strongly on structural properties of resultant CdXHg1-XSequantum dots.
SIL-based confocal fluorescence microscope for investigating individual nanostructures

We developed a fluorescence confocal microscope equipped with a hemispherical solid immersion lens (SIL) and apply it to study the optical properties of light-harvesting complexes. We demonstrate that the collection efficiency of the SIL-equipped microscope is significantly improved, as is the spatial resolution, which reaches 600 nm. This experimental setup is suitable for detailed studies of physical phenomena in hybrid nanostructures. In particular, we compare the results of fluorescence intensity measurements for a light-harvesting peridinin-chlorophyll-protein (PCP) complex with and without the SIL.
The kinetic energy spectrum in the free atmosphere—1 second to 5 years

An energy spectrum of wind speed at altitudes from 3 to 20 km is constructed from rawinsonde and aircraft data originating in the U.S.A. and the U.S.S.R. Most of the observations are concentrated near 40° N and cover periods from 1 sec to 5 year. The spectrum is subdivided into three major regions separated by gaps: a sharp annual maximum, a synoptic (or macroscale) maximum at periods from 1–2 months to 3–4 days, and a microscale maximum with periods of 1–3 min. It is shown that the micro-scale maximum is not a permanent feature of the spectrum. Usually high frequency turbulence is supressed by stable stratification in the free atmosphere and its energy is negligibly small. Spectra in the free atmosphere and near the ground are compared. An attempt is made to relate frequency and wave number spectra at synoptic scales. DOI: 10.1111/j.2153-3490.1970. tb01517.x
Nonparametric and Semiparametric Methods in Econometrics and Statistics

This collection of papers delivered at the Fifth International Symposium in Economic Theory and Econometrics in 1988 is devoted to the estimation and testing of models that impose relatively weak restrictions on the stochastic behaviour of data. Particularly in highly non-linear models, empirical results are very sensitive to the choice of the parametric form of the distribution of the observable variables, and often nonparametric and semiparametric models are a preferable alternative. Methods and applications that do not require string parametric assumptions for their validity, that are based on kernels and on series expansions, and methods for independent and dependent observations are investigated and developed in these essays by renowned econometricians.
Pressure measurements on a pitching airfoil in a water channel

Measurements of unsteady pressures over a symmetric NACA 0015 airfoil performing pitching maneuvers are reported. The tests were performed in an open-surface water channel specially constructed for this purpose. The design of the apparatus allowed the pressure measurements to be made to a very high degree of spatial and temperal resolution. Reynolds numbers in the range of 5.2×10 4 to 2.2×10 5 were studied. Although the results qualitatively agreed with earlier studies performed at similar Reynolds numbers, the magnitudes of pressure and aerodynamic forces measured were observed to be much larger than those measured in earlier pitchup studies
Error rates of unmixed hyperspectral imagery

When analyzing a hyperspectral image using the linear mixture model, one makes a variety of assumptions relating to the distribution of error and the underlying mixture model. In order to test the validity of these assumptions, a simple model of hyperspectral data is examined. Generally, simple linear unmixing is performed assuming that sensor error rates are the same for each band. This assumption is violated quite easily when unmixing reflectance data. Assuming a perfect sensor, image data that perfectly obeys the linear mixture model, and perfectly known end-member spectra, the error rate for least squares linear unmixing is determinable using a simple formula. When data is transformed into reflectance, the error rates for the unmixed image increases by a significant factor due to the poor statistical normalization of the resulting data. As a means of mitigating error in unmixed imagery, two alternative unmixing methods are examined: non-negative least squares, and total least squares. Non-negative least squares can be shown to significantly outperform simple least squares, while total least squares behaves pathologically. Unmixing hyperspectral images inherently transfers error from the original hyperspectral image to the unmixed fraction plane image. Care should be taken when unmixing, so that this error is known and minimized.
Kinetic Theory of Shock Tube Problems for Binary Mixtures

The flow of binary gas mixture in a shock tube is treated according to the kinetic theory as an initial value problem. The model equations of Gross‐Krook and Morse are used. The numerical procedure is extended from the method proposed by Chu in his work on shock tube problems for a single‐component gas. The formation of shock waves, diffusion of the contact layers and dispersion of expansion waves for both species are clearly indicated in the solutions. The stationary shock structures have been obtained in a relaxation process from initial discontinuity by superposing a shock wave speed. Argon and neon are chosen as the binary mixture. Shock Mach numbers 1.369, 1.5, and 2.07 with equal mole fractions of the mixture are calculated.