Miracle-dz/UniFAR-FTUs huggingface dataset:
GAFD Special issue on “ Physics and Algorithms of the Pencil Code ” Non-Fourier description of heat flux evolution in 3 D MHD simulations of the solar corona

The hot loop structures in the solar corona can be well modeled by three dimensional magnetohydrodynamic simulations, where the corona is heated by field line braiding driven at the photosphere. To be able to reproduced the emission comparable to observations, one has to use realistic values for the Spitzer heat conductivity, which puts a large constrain on the time step of these simulations and therefore make them computationally expensive. Here, we present a non-Fourier description of the heat flux evolution, which allow us to speed up the simulations significantly. Together with the semi-relativistic Boris correction, we are able to limit the time step constrain of the Alfvén speed and speed up the simulations even further. We discuss the implementation of these two methods to the Pencil Code and present their implications on the time step, and the temperature structures, the ohmic heating rate and the emission in simulations of the solar corona. We find that with the use of the non-Fourier description of the heat flux evolution and the Boris correction, we can increase the time step of the simulation significantly without moving far away from the reference solution. However, for too low values of the Alfvén speed limit, the simulation moves away from the reference solution und produces much higher temperatures and stronger emission structures.
Theoretical models for quasi-two-dimensional mesomorphic monolayers and membrane bilayers

Simple models are developed for the first-order (main) gel–fluid phase transition in lipid mono-and bilayers. The lipid chains are assumed to lie on a triangular lattice in both phases and to interact via anisotropic van der Waals forces. The article begins with a review of previous experimental and theoretical work. Next a two-state Ising-like model is developed and shown to give a good qualitative description of the main phase transition of both mono- and bilayers and of statistical fluctuations about this transition. The article continues with a description of a more quantitative 10-state model for the main bilayer phase transition due to Pink. The polar head interactions are now explicitly taken into account. It is shown that this model is able to account for a variety of experimental results, e.g., Raman scattering data for pure lipid bilayers, phase separations for mixed lipid systems, and ionic permeability data for bilayers. The 10-state model is then extended to include the presence of intrinsic .
Slip-stick step-scanner for scanning probe microscopy

A slip-stick positioning system is shown to work as a step-by-step scanning device. Scanning confocal optical images with sizes up to 100μm by 100μm were taken in reflectivity using a 635nm wavelength laser and an objective of numerical aperture=0.8. The images were taken under ambient and cryogenic conditions on samples with periodic patterns as well as with nanomechanical systems. They show exceptional low distortion and high linearity. The use of the slip-stick step motion for image scanning simplifies the scanning confocal microscope since the long-range positioning unit and the scanning unit merge into only one unit that can do both.
An observer for flexible joint robots

The problem of state observation of robots that have elastic joints is discussed. Outputs are assumed to be the global link coordinates and their time derivatives, and a nonlinear observer is proposed which asymptotically reconstructs all the robot state variables. The dynamic behaviour of the observation algorithm is illustrated by simulation tests referred to a manipulator with three revolute elastic joints. To verify the observer robustness, the previous simulation tests were repeated by using the same observer, designed for a nominal payload of 5 kg, and actual robot payloads of 0 and 10 kg. The differences with respect to the nominal case are not appreciable. However, the steady-state joint errors, which were about 10/sup -6/ rad in the nominal case, became about 10/sup -4/ rad. >
Ion-acoustic solitons in an inhomogeneous multicomponent plasma with negative ions

Ion-acoustic solitary waves are studied in an inhomogeneous multicomponent plasma by the augmentation of a K-dV equation wherein a simple form of ionization has been taken to show its interaction in changing the salient features of the soliton, as compared to those observed in a homogeneous plasma. As expected, the negative ions in the plasma bring a drastic alteration on the ion-acoustic solitons, thereby establishing a new era by showing the solitary waves to be studied by a modified K-dV equation. The emphasis has been on determining how the ionization and density gradient in the inhomogeneous plasma affect the solitons. >
Multiple backscattering and depolarization from water clouds for a pulsed lidar system

Abstract A computational approach for the multiple backscattering from spherical cloud droplets for a collimated pulsed radar system has been developed, based on the geometry of the system. The radiative transfer relationships include a complete set of Stokes' parameters. The depolarization ratio of the multiple backscattering from a volume of spherically symmetrical and uniformly distributed water drops is obtained. Calculations are performed for secondary backscattering from water clouds in terms of wavelength, cloud height, beam width and particle number density. It is found that the depolarization does not have a significant dependence on the wavelength in the visible and near visible, or on the distance between the target and receiver. However, the receiver beam width and particle number density significantly affect the depolarization as well as the returned power. A small receiver beam width, on the order of 10−4 rad, is recommended for measurement of the depolarization due to ice crystals in clouds.
Generalized method of moments for three-dimensional penetrable scatterers

We outline a generalized form of the method-of-moments technique. Integral equation formulations are developed for a diverse class of arbitrarily shaped three-dimensional scatterers. The scatterers may be totally or partially penetrable. Specific cases examined are scatterers with surfaces that are perfectly conducting, dielectric, resistive, or magnetically conducting or that satisfy the Leontovich (impedance) boundary condition. All the integral equation formulations are transformed into matrix equations expressed in terms of five general Galerkin (matrix) operators. This allows a unified numerical solution procedure to be implemented for the foregoing hierarchy of scatterers. The operators are general and apply to any arbitrarily shaped three-dimensional body. The operator calculus of the generalized approach is independent of geometry and basis or testing functions used in the method-of-moments approach. Representative numerical results for a number of scattering geometries modeled by triangularly faceted surfaces are given to illustrate the efficacy and the versatility of the present approach.
Shapes and Correlations as Observational Discriminants for the Origin of Diffuse Bands

Observations are made of the diffuse interstellar bands in heavily reddened early-type stars in three associations (Cas OB6, Be 87, and Cyg OB2) where the extinction is attributed mostly to material at intermediate densities between molecular clouds and the diffuse medium. The degree of correlation with E(B-V) separates the lines into at least two groups. Detailed analysis of line profiles reveals diversity in the outline of wings ranging from a nearly symmetric Lorentzian shape for 6284 A to an extended long-wavelength wing in 6269 A. It is suggested that the origin of the lines can be explained by the vibronic transitions in large molecules. 58 references.
A chromatic adaptation transform and a colour inconstancy index

A description is given of the Chromatic Adaptation Transform, CMCCAT97, used in the recently adopted colour appearance model, CIECAM97s, and the transform is used to derive a colour inconstancy Index, CMCCON97, for changes caused by the use of illuminants of different chromaticities. A worked example is included. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 154–158, 1998
Use of Real-Time Multisensor Data to Assess the Relationship of Normalized Corn Yield with Monthly Rainfall and Heat Stress across the Central United States

Abstract This study evaluated the suitability of rain estimates based on the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network to estimate yield response to rainfall on a county scale and to provide real-time information related to crop stress resulting from deficient or excessive precipitation throughout the summer. The relationship between normalized corn yield and rainfall was examined for nine states in the central United States for 1997–99 and 2001–02. Monthly rainfall estimates were computed employing multisensor precipitation estimate (MPE) data from the National Centers for Environmental Prediction and quality-controlled (QC_Coop) and real-time (RT_Coop) NWS cooperative gauge data. In-season MPE rain estimates were found to be of comparable quality to the postseason QC_Coop estimates for predicting county corn yields. Both MPE and QC_Coop estimates were better related to corn yield than were RT_Coop estimates, presumably because of the lower density of RT_Coo.
Newton's Law and Integrability of Nonholonomic Systems

In this paper we consider nonholonomic control systems on Riemannian manifolds. Such systems evolve on subbundles of tangent bundles, defined by the nonholonomic constraints. This paper promotes the view of such systems as the restriction to the nonholonomic subbundle of "Newton law"-type problems on the entire tangent bundle, defined by, in general, non-Riemannian connections. These connections should be related to specific geometric properties of the nonholonomic system. We introduce a particular class of connections and demonstrate the richness of the class through four examples---the rolling ball, the constrained particle, the rolling penny, and the generalized rolling ball. This class of connections is strongly related to questions of integrability of the original nonholonomic system. This, in turn, provides additional insight into the relation between nonholonomic control systems formulated as kinematic equations and those that are formulated as the full dynamic equations.
DIRECT LIQUID COOLING OF ELECTRONIC CHIPS BY SINGLE-PHASE FORCED CONVECTION OF FC-72

Experimental studies of single-phase heat transfer with the working fluid FC-72 from a single chip and a four-in-line chip module mounted on one wall of a vertical rectangular channel are carried out. Both flush-mounted and protruding chip configurations are investigated with the channel height being equal to the ship length. The Reynolds number based on chip length ranged from 2.2 × 103 to 6.3 × 104 (3.0 × 103 < ReD < 8.4 × 104) for an inlet temperature of 25°C. Results for a single flush-mounted chip are in good agreement with those obtained for the most upstream chip of the multichip module. Heat transfer data of a single heated protruding chip located downstream agree well with the results from the single flush-mounted chip. Heat transfer coefficients from flush-mounted chips are less than those from protruding chips.
The Effect of Asset Growth, Sales Growth and Capital Structure on Financial Distress and Value of the Firm in Sub-Sector Food and Beverage with Good Corporate Governance as Moderation

Purpose: The value of the firm is an important factor to determine the success of an enterprise. This study has eight problem formulations. Design/methodology/approach: The variables used in this study are asset growth, sales growth, capital structure, financial distress, the value of the firm, and good corporate governance as moderation. The population used in the study was 26 sub-sectors of food and beverage. As a sample, the researchers used many as 13 sub-sector of food and beverage. The research period was three years (2019-2021) during the pandemic Covid-19. Findings: The results of the study showed that asset growth had no effect or was not significant to the value of the firm, sales growth had no effect or insignificant effect on the value of the firm, and capital structure had an effect, in another word it was significant to the value of the firm, asset growth had no effect or was not significant to financial distress, sales growth had an effect or were significant to financial distress, the capital structure was influential and significant to financial distress, financial distress had no effect or insignificant effect on the value of the firm and financial distress with the value of the firm moderated by good corporate governance produces insignificant. Research limitations/implications: Based on the conceptual framework, researchers used Partial Least Square data processing and obtained three significant results, namely capital structure has a significant effect on the value of the firm, asset growth has a significant effect on financial distress and good corporate governance has a significant effect on the value of the firm. While the five influences are not significant. Paper type: Research paper
Beamforming with collocated microphone arrays

A collocated microphone array, including three gradient microphones with different orientations and one omnidirectional microphone, was used to acquire data in a sound‐treated room and in an outdoor environment. This arrangement of gradient microphones represents an acoustic vector sensor used in air. Beamforming techniques traditionally associated with much larger uniformly spaced arrays of omnidirectional sensors are extended to this compact array (1 cm3) with encouraging results. A frequency–domain minimum‐variance beamformer was developed to work with this array. After a calibration of the array, the recovery of sources from any direction is achieved with high fidelity, even in the presence of multiple interferers. SNR gains of 5–12 dB with up to four speech sources were obtained with both indoor and outdoor recordings. This algorithm has been developed for new MEMS‐type microphones that further reduce the size of the sensor array.
Gas-phase CO2, C2H2, and HCN toward Orion-KL

The infrared spectra toward Orion-IRc2, Peak 1 and Peak 2 in the 13.5-15.5m wavelength range are presented, obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory. The spectra show absorption and emission features of the vibration-rotation bands of gas-phase CO2 ,H CN, and C 2H2, respectively. Toward the deeply embedded massive young stellar object IRc2 all three bands appear in absorption, while toward the shocked region Peak 2 CO2 ,H CN, and C2H2 are seen in emission. Toward Peak 1 only CO2 has been detected in emission. Analysis of these bands shows that the absorption features toward IRc2 are characterized by excitation temperatures of175-275 K, which can be explained by an origin in the shocked plateau gas. HCN and C2H2 are only seen in absorption in the direction of IRc2, whereas the CO2 absorption is probably more widespread. The CO2 emission toward Peak 1 and 2 is best explained with excitation by infrared radiation from dust mixed with the gas in the warm component of the shock. The similarity of the CO2 emission and absorption line shapes toward IRc2, Peak 1 and Peak 2 suggests that the CO2 is located in the warm component of the shock (T 200 K) toward all three positions. The CO2 abundances of10 8 for Peak 1 and 2, and of a few times 10 7 toward IRc2 can be explained by grain mantle evaporation and/or reformation in the gas-phase after destruction by the shock. The HCN and C2H2 emission detected toward Peak 2 is narrower (T 50-150 K) and originates either in the warm component of the shock or in the extended ridge. In the case of an origin in the warm component of the shock, the low HCN and C2H2 abundances of10 9 suggest that they are destroyed by the shock or have only been in the warm gas for a short time (t< 10 4 yr). In the case of an origin in the extended ridge, the inferred abundances are much higher and do not agree with predictions from current chemical models at low temperatures.
A 230 GHz heterodyne receiver array for the IRAM 30 m telescope

We describe the technical concept, properties, and performance of HERA (HEterodyne Receiver Array) at the IRAM 30 m telescope. HERA is a multibeam, waveguide SIS receiver that greatly improves mapping speed in various ob- serving modes and also provides possibilities for new high-sensitivity observing of small sources. Future extensions with a second polarization module will permit spectro-polarimetry. We present some examples of astronomical maps with HERA.
Computational stereoscopic zoom

Optical zoom lenses mounted on a stereo color camera magnify each left and right two-dimensional (2-D) image increasing focal length. However, without adjusting the baseline distance, the optical zoom distorts three-dimensional (3-D) perception because the optical zoom magnifies projected 2-D images not an original 3-D object. We propose a computational approach to stereoscopic zoom that magnifies stereo images without 3-D distortion. We computationally manipulate the baseline distance and convergence angle between left and right images by synthesizing novel view stereo images based on the depth information. We suggest a volume-predicted bidirectional occlusion inpainting method for novel view synthesis. Original color image is warped to the novel view determined by the adjusted baseline and convergence angle. Rear volume of each foreground object is predicted, and the foreground portion of each occlusion region is identified. Then we apply our inpainting method to fill in the foreground and background respectively. Experimental results show that the proposed inpainting method removes the cardboard effect that significantly decreases the perceptual quality of synthesized novel view image but has never been addressed in the literature. Finally, 3-D object presented by stereo images is magnified by the proposed stereoscopic zoom method without 3-D distortion.
ROLE OF THE MENTAL REPRESENTATION IN ENHANCING MOTOR LEARNING AND PERFORMING GYMNASTIC ELEMENT

The aim of the present study was to analyze the effect of three intervention modalities ((a) external visual imagery modality, (b) verbal feedback modality and (c) visualization modality) on the Roll backward to handstand. 42 females’ students (age 20.6 ± 1.3 years) voluntarily took part in this study. Subjects were assigned into three groups according to three learning modalities: mental imagery modality, verbal feedback modality and visualization modality. During the two testing sessions (before and after training sessions), the participant was marked according to the FIG Code of Points. The results thus reveal a significant effect on the training, therefore on the learning of the backward roll followed by a handstand by the method of mental imagery. Thus, the mental imagery seems to be a tool for transmission of knowing and training by excellence making it possible to the students to progress while getting rid of the lack of motivation, organization, implication and work. Moreover, the results gathered following the gymnastic practice also show an improvement of the performance of the first group that had to undergo training by verbal feedback. This supports the idea that the training by the method of verbal feedback improves the technical performance of a gymnastic element. However, the method of training by visualization of a model appears to be the less developed by the participants in comparison with the mental imagery and the verbal Feedback.
Attitude Estimation for Sounding Rockets Using Microelectromechanical System Gyros

An attitude determination and in-flight calibration extended Kalman filter and the corresponding smoother have been developed to estimate three-axis attitude of spinning sounding rockets. The attitude determination system uses low-accuracy commercial microelectromechanical system rate gyros, coupled with a three-axis magnetometer and a one-axis sun sensor. Because only postflight analysis is necessary, the improved performance of a smoother is used in the attitude reconstruction because postflight computation allows the use of a noncausal algorithm. Gyro misalignment and scale-factor errors are proportional to the angular rate, and spin-stabilized rockets without a despin unit usually have a large angular velocity in the range of 4-6 cycles per second about the spin axis. Therefore, gyro misalignment and scale-factor errors can have a significant effect on the attitude propagation, which is based on the gyro measurements. In this work, in-flight calibration is carried out, estimating sensor relative misalignments in addition to bias and scale-factor errors. To ensure filter convergence, an initialization algorithm suitable for producing an initial attitude estimate from a vector measurement and a scalar measurement has been developed. The initialization algorithm uses an attitude representation based on the minimum quaternion combined with a search method. The filter and smoother have been tested using a truth-model simulation, and the accuracy is shown to be dependent on the rocket motion. A rich motion time history makes the parameters more observable and thereby the estimates more accurate. Simulation results indicate that an attitude accuracy on the order of 0.5-1 degrees (3 sigma) can be achieved with a low-cost suite of sensors.
Different approaches of conducting ergonomic assessment utilizing digital
 human models and motion capture in industrial site assembly

The further development of Industry 4.0 to 5.0 focuses even more on human-centred and sustainable production. The ergonomic factor plays a major role, as it is crucial for the well-being and productivity of workers and should already be considered in production planning. One of the most common ergonomic analysis methods is the “Ergonomic As-sessment Worksheet (EAWS)”, which is based on a paper & paper method for assessing human working posture. Currently, there are various approaches to automate this evalua-tion process with the help of digital human models or motion capture systems. All of these methods have their pros and cons; however, companies are faced with the problem of finding the best suited method for their processes. This paper compares three different methods to conduct an EAWS study for industrial site assembly in terms of methodology, effort, and efficiency. For this purpose, an evaluation of the physical movement with the original manual paper and pencil method was created and a generic movement with a digital human model was implemented and automatically evaluated. Furthermore, using motion capture, the automatic recording of physical movement data was carried out, which was computer-assisted evaluated using digital human models. To exclude software-specific inconsistencies, we used two different process simulation tools. As a final result, this paper shows a comparison of different implementation possibilities of the EAWS anal-yses and indicates the effort and efficiency for their use in industry. Furthermore, this initial analysis provides an opportunity for further research on digital human models and motion capture.