Miracle-dz/UniFAR-FTUs huggingface dataset:
The PSTD algorithm: A time-domain method combining the pseudospectral technique and perfectly matched layers

Simulations of underwater acoustic wave propagation require solutions for large‐scale multidimensional problems. The traditional finite‐difference time‐domain (FDTD) method needs a fine discretization of 8–20 cells per wavelength in order to give accurate results. On the other hand, the pseudospectral method, even though efficient, suffers from the wraparound effect due to the use of discrete Fourier transform. This effect severely limits the applications of the pseudospectral method to large‐scale problems. Hence, a popular way of simulating underwater acoustic wave propagation is to use the parabolic equation (PE) methods which neglect backscattering. In this work, Berenger’s perfectly matched layers (PML) are used in the pseudospectral method to eliminate the wraparound effect. To achieve a high accuracy, this method requires only two cells per wavelength which is dictated by the Nyquist sampling theorem. As a result, it can solve at least 64 times larger 3‐D problems than the FDTD method with the same.
ECONOMIC GROWTH AND DEVELOPMENT OF THE CONCEPT OF CONVERGENCE – THEORETICAL BASIS

The aim of the study is to outline the theoretical foundations of the concept of convergence related to economic growth, as well as to systematise the different types of convergence. The development of the concept of convergence, which is a result of many applied researches worldwide on the connection between growth and convergence, has been theoretically traced. The specifics of neoclassical and endogenous theories of economic growth are briefly presented as the basis of the concept of convergence, including its types – alpha (absolute), beta (relative), “club” and sigma convergence. The types of convergence that appeared in these studies are critically analysed – structural, based on labour productivity, regional, price, monetary, business cycle, and others. For EU countries, the interaction between nominal and real convergence has been studied. JEL: E13; F63; N10; O11
Theory of Dichroism in the Electromagnetic Response of Superconductors

A microscopic theory of dichroism in the magneto-optical properties of superconductors is presented. Four distinct mechanisms for dichroism in superconductors are identified. Two are modifications of mechanisms known from the normal state, and two are novel effects found in superconductors only. The theory is illustrated by numerical calculations for a simple model system. The interplay between relativistic symmetry breaking and superconducting coherence is found to give rise to a variety of new effects, not known from dichroism in the normal state. {copyright} {ital 1997} {ital The American Physical Society}
On-Line Learning with a Perceptron

We study on-line learning of a linearly separable rule with a simple perceptron. Training utilizes a sequence of uncorrelated, randomly drawn N-dimensional input examples. In the thermodynamic limit the generalization error after training such examples with P can be calculated exactly. For the standard perceptron algorithm it decrease like (N/P)1/3 for large P/N, in contrast to the faster (N/P)1/2-behaviour of the so-called Hebbian learning. Furthermore, we show that a specific parameter-free on-line scheme, the AdaTron algorithm, gives an asymptotic (N/P)-decay of the generalization error. This coincides (up to a constant factor) with the bound for any training process based on random examples, including off-line learning. Simulations confirm our results.
Microwave and infrared dielectric response in BaTiO3 based relaxor ferroelectrics

Microwave (MW), infrared (IR) dielectric response, and Raman spectra of BaZryTi1‐yO3 (BZT) (y = 0.25–0.40) and BaTi1‐zSnzO3 (BTS) (z = 0.15–0.30) ceramics were studied systematically. As the substitution levels increased, the evolution from normal ferroelectric to canonical relaxor was observed. BaTiO3 based relaxor ferroelectrics have high tunability, MW permittivity, and loss tangent. IR analysis confirmed that the relaxor behavior in BZT and BTS was caused by the cationic disorder with BO6 octahedron and the origin of larger diffuseness in BTS dielectric peak was attributed to a distinct split of BO6 bending. Compared with BST, the soft mode in BaTiO3 based relaxor ferroelectrics hardened slightly and became harmonic with increasing substitution levels, resulting in high tunability for BaTiO3 based relaxors. The variation in tunability of BZT with composition is larger than that of BTS, due to the larger variation in softest mode with composition for BZT. Raman scattering showed that, in comparison with cubic‐BST, the bands at ∼730 cm−1 were observed in cubic‐BZT and ‐BTS, owing to the positional disorder at B‐site cation. However, an extra band at ∼770 cm−1 in BZT appeared and red‐shifted, whose intensity increased with the substitution levels increasing. It is of particular interest that the upward shift of A1(TO2) mode of the samples with higher substitution levels indicated a tighter bonding between the cations and the anions, which led to a smaller permittivity of the samples with higher substitution levels.
Linear Polymer Chain Diffusion in Semi-flexible Polymer Network: A Dissipative Particle Dynamics Study

Linear polymer chains transport in the crowded biological environment is profoundly important to biomedical engineering and nanotechnology. Cytoskeleton, which can be modelled as a semi-flexible polymer network, acts as a barrier when the linear polymers diffuse inside the cell. The diffusion of linear polymers with length N in this polymer network is investigated by the dissipative particle dynamics (DPD) in the present study. Rouse theory is applied to analyze the conformational dynamics of the linear polymers based on the numerical results. It is found that the geometric constraint length Na is a crucial parameter to describe the role of the network of the polymer diffusion. Analyses on the Rouse modes show that, in short wavelength regime, the relaxation time obtained in numerical simulation follows the the prediction of the Rouse theory. As the increasing of the wavelength, the linear polymer exhibits a transition from reptation behavior to the spatially homogeneous behavior at critical length scale Na, which is illustrated by different scaling laws dependent on wavelength. Based the analyses on the Rouse modes and mean square displacements of the linear polymer, we present a non-dimensional conformational dynamics function dependent on time, with which a scaling law is proposed to predict the long time diffusivity of the linear polymer in semi-flexible polymer network with different mesh size. It is shown that the prediction is well consistent with our DPD simulation results.
A Critical Stylistic Analysis of Polarization in American President Joe Biden's Campaign in the Last American Elections

The opposition between two persons, parties or groups is referred to as polarization. Such disagreement is interpreted using a variety of ideological techniques due to the detrimental effects of the polarizing strategy used in political debates, which have an impact on societies generally and the political stability of the countries in particular. The purpose of the current study is to explore this strategy used by U.S. President Joe Biden in his tweets to indicate his political and ideological intentions and goals during his last election. The research employs Jeffries' approach of critical stylistic analysis (2010). In order to make up for the fuzziness of CDA, Jeffries (2010) aimed to propose a collection of devices within the critical stylistics (CS). Text techniques used in literary and non-literary speech use language structures to describe the world, using linguistic forms leading to the generalization "that all texts are ideological. Thus, "all texts producers produce hidden ideologies to influence or manipulate.
Novel mechanisms of Ɛ -poly lysine as an antimicrobial agent and its food preservative application

In the present situation, it is very important to know about the awareness of healthy eating habits and the consumers have less time for food preparation. Due to this the research is going on the production of fresh cut fruits. In common fruits will be undergoing several microbial contaminations, by reducing its shelf life period epsilon poly lysine is used as natural preservatives in food production. It is safe for human consumption and biodegradable. This epsilon poly lysine has several characteristics like water soluble, thermo stable and cationic homo-biopolymers between Ɛ - amino groups and α -carboxyl groups of 25-35-L-Lysine residues. This review article addresses the Ɛ - poly lysine as natural preservative, antimicrobial agent, and potential applications of Ɛ -poly lysine.
YOLOv4‐tiny‐based robust RGB‐D SLAM approach with point and surface feature fusion in complex indoor environments

Algorithm frameworks based on feature point matching are mature and widely used in simultaneous localization and mapping (SLAM). However, in the complex and changeable indoor environment, feature point matching‐based SLAM currently has two major problems, namely, decreased accuracy of pose estimation due to the interference caused by dynamic objects to the SLAM system and tracking loss caused by the lack of feature points in weak texture scenes. To address these problems, herein, we present a robust and real‐time RGB‐D SLAM algorithm that is based on ORBSLAM3. For interference caused by indoor moving objects, we add the improved lightweight object detection network YOLOv4‐tiny to detect dynamic regions, and the dynamic features in the dynamic area are then eliminated in the algorithm tracking stage. In the case of indoor weak texture scenes, while extracting point features the system extracts surface features at the same time. The framework fuses point and surface features to track camera pose. Experiments on the public TUM RGB‐D data sets show that compared with the ORB‐SLAM3 algorithm in highly dynamic scenes, the root mean square error (RMSE) of the absolute path error of the proposed algorithm improved by an average of 94.08%. Camera pose is tracked without loss over time. The algorithm takes an average of 34 ms to track each frame of the picture just with a CPU, which is suitably real‐time and practical. The proposed algorithm is compared with other similar algorithms, and it exhibits excellent real‐time performance and accuracy. We also used a Kinect camera to evaluate our algorithm in complex indoor environment, and also showed high robustness and real‐time. To sum up, our algorithm can not only deal with the interference caused by dynamic objects to the system but also stably run in the open indoor weak texture scene.
What makes entrepreneurial learning difficult: cognitive conflicts or cultural clashes?

ABSTRACT As more entrepreneurial experiences are integrated into engineering programs, students are faced with new challenges they need help in managing. While previous research has identified entrepreneurial activities that engineering students struggle with, the antecedents of these difficulties have not been directly investigated. Drawing on an ethnographic study in a project-based entrepreneurship course, this paper investigates difficulties as caused by both cognitive conflicts and cultural clashes. The findings suggest that difficulties with entrepreneurial activities do not necessarily stem from lack of entrepreneurial capabilities on behalf of students, they can just as well stem from legitimate conflicts of interest that students and teachers need to navigate. As such, difficulties cannot always be solved by students learning more about entrepreneurship. As shown in the study, collaborative and externally oriented learning activities – mainstays of project-based entrepreneurship courses – particularly contribute to putting competing social demands on students.
Modeling ultrasound interaction with cancellous bone: investigation on the nature of the two compressional waves

Although ultrasound might be useful to assess bone quality, the mechanisms of ultrasound propagation in trabecular bone are still poorly understood. For example the propagation of a short pulse that leads, under some conditions, to two transmitted longitudinal waves, a fast and a slow one, is not well explained yet. The objective of this work is to further investigate the nature of these two longitudinal waves in simplified bone model media. The approach is to determine if the fast wave could result from a guided propagation in the solid matrix, the slow wave being due to the propagation in the surrounding fluid (bone marrow). In this context, we studied the propagation of the coherent waves through simplified and customizable binary structures, obtained by a random addition of scatterers, with characteristic dimensions, material properties and anisotropy similar to those of bone. The benefit of such simplified structures is that ultrasound propagation in the entire medium can be theoretically studied from the properties of a single scatterer.
Relationship between frame rates and subpopulation structure of bovine sperm divided by their motility analyzed by a computer-assisted sperm analysis system.

The authors investigated the relationship between frame rates and subpopulation structure of bovine sperm divided by their motility analyzed by a computer-assisted sperm analysis (CASA). Kinematic parameters of bovine sperm incubated in Brackett & Oliphant medium with and without calcium ionophore for 0, 1, 5, 10, 15, 20, 25, and 30 min were evaluated by a CASA at 150 frames per second (fps) and analyzed structure of sperm motility subpopulation by cluster analysis. Then, we converted CASA data at 150 fps to 75, 50, and 30 fps and evaluated the structures of sperm motility subpopulation at different fps in each sperm by a discriminant analysis. As the results, the structure of sperm motility subpopulation was affected by frame rate. Sperm were divided into six clusters at 150, 75, and 50 fps; on the other hand, there were five clusters at 30 fps. Straight-line velocity was similar at all frame rates. However, as the frame rate became higher, curvilinear velocity and beat cross frequency of sperm head increased significantly, whereas lateral sperm head displacement decreased significantly. In conclusion, higher frame rate at 150 fps is recommended to capture the trajectory of sperm accurately by CASA in the present study.
The Nucleolus as a Solution of a Minimization Problem

The following problem is discussed : Is it possible to represent the nucleolus of an n-person game as a solution of a linear programming problem? An affirmative answer is given for the case that the set of payoff vectors is a polytope. An example is described, showing that the above may not be possible when the set of payoff vectors is just convex and compact.
Analysis of User Satisfaction Level of myIM3 Application Using TAM Method

User satisfaction is a critical thing in handling a business. The company must be capable to provide quality services for the products/services provided by them. MyIM3 application is an application developed by PT. Indosat Ooredoo Hutchison to check and purchase credit and data packages online, find promotions offered by Indosat Ooredoo Hutchison, etc. More than 10 million users have downloaded the myIM3 app on the PlayStore and AppStore. The number of features offered makes users often experience problems in accessing the application so it affects user satisfaction. This study aims to find a correlation between variables to determine the level of user satisfaction with myIM3 application. This study applied Technology Acceptance Model (TAM) method. The number of respondents obtained by using the calculation of Slovin's formula was 400. The technique of data collection used in this study was by distributing questionnaires to myIM3 users throughout the public with various criteria. The technique of data analysis used in this study was Structural Equation Model (SEM). From this study, the hypothesis that has the most significant influence is Attitude Toward Using to Behavioral Intention to Use, while other hypotheses which also have a significant influence are Perceived Ease of Use to Perceived Usefulness, Perceived Usefulness to attitude Toward Using, Perceived Ease of Use To attitude Toward Using, and Behavioral Intention to Use to User Satisfaction.
An Efficient View-Point Invariant Detector and Descriptor

Many computer vision applications need keypoint correspondence between images under different view conditions. Generally speaking, traditional algorithms target applications with either good performance in invariance to affine transformation or speed of computation. Nowadays, the widely usage of computer vision algorithms on handle devices such as mobile phones and embedded devices with low memory and computation capability has proposed a target of making descriptors faster to computer and more compact while remaining robust to affine transformation and noise. To best address the whole process, this paper covers keypoint detection, description and matching. Binary descriptors are computed by comparing the intensities of two sampling points in image patches and they are matched by Hamming distance using an SSE 4.2 optimized popcount. In experiment results, we will show that our algorithm is fast to compute with lower memory usage and invariant to view-point change, blur change, brightness change, and JPEG compression.
A deep optical survey of a small region in Aquarius.I : ― Stellar photometry and galactic structure

Identification et classification d'objets de B≤20,0 dans 0,31 degres 2 centres sur les coordonnees de 1950,0 α=22 h 03 m 04,5 s et δ=−18°55'03''. On determine les magnitudes B et V de 601 etoiles normales et 2 naines blanches et on utilise les donnees pour etudier la structure galactique dans cette direction
A symbolic-arithmetic for teaching double-black node removal in red-black trees

A red-black (RB) tree is a data structure with red and black nodes coloration. The red and black color of nodes make up the principal component for balancing a RB tree. A balanced tree has an equal number of black nodes on any simple path. But when a black leaf node is deleted, a double-black (DB) node is formed, thus, causing a reduction in black heights and the tree becomes unbalanced. Rebalancing a RB tree with a DB node is a fairly complex process. Teaching and learning the removal of DB nodes is also challenging. This paper introduces a simplified novel method which is a symbolic-algebraic arithmetic procedure for the removal of DB nodes and the rebalancing of black heights in RB trees. This simplified approach has enhanced student learning of the DB node removal in RB trees. Feedback from students showed the learnability, workability and acceptance of the symbolic-algebraic method in balancing RB trees after a delete operation.
A 14 cm×36 cm volume negative ion source producing multi‐ampere H− ion beams

A large volume negative ion source, which has a newly devised magnetic filter called a PG filter, was designed and tested. The PG filter produces a uniform magnetic filter field over a large extraction area of 14×36 cm2 by flowing a high current through the plasma grid itself. By optimizing the filter strength, we succeeded to produce 3.4‐A 75‐keV negative hydrogen ion beams for 50 ms from 253 apertures of 11.3 mm diam with an average current H− density of 13 mA/cm2.
Precession Mechanism of Nematic Liquid Crystal Droplets under Low Power Optical Tweezers

Optical tweezers is a magnificent tool for microscopic manipulation. Owing to few piconewton noninvasive trapping force, the tiny objects from micro sand beads down to living bacteria can be trapped under optical tweezers system. Liquid crystals (LC) are materials that enriched of optical properties providing various phemomena that can be applied for technology. In this report, we applied optical tweezers to nematic liquid crystal system for the optical manipulation study. 5CB (4-cyano-4’-pentylbiphenyl) was used with an appropriate surfactant to prepare nematic liquid crystal (NLC) droplets at room temperature. NLC droplets in radial and bipolar configurations can be formed. They react with light angular momentum and reveal dynamic and static changes through spinning and changing of internal configuration. Several recent articles reported spinning dynamics of NLC droplets under high power trapping (more than a few hundred milliwatts), however, high power caused disturbance in internal configuration of droplets. Dynamic changes of droplet under low power trapping (lower than 100 mW) conducting so far were reported unsuccessful. Here we report the first investigation on behaviour of radial NLC droplet under low power optical trap. The configuration of droplets was not disturbed under low power trapping. We investigated the dynamic behaviour of non-disturbed NLC droplet in low power optical trap.
Notched velocity profiles and the radial electric field in high ion temperature plasmas in the Tokamak Fusion Test Reactor

A large “notch,” or non-monotonic feature, appears in measured toroidal velocity profiles of the carbon impurity in the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Fusion 26, 11 (1984)], centered near the radius of strongest ion temperature gradient. This is explained as a consequence of radial momentum transport dominated by anomalous diffusion together with parallel heat friction on the impurity ions arising from the hydrogenic neoclassical parallel heat flow. The toroidal velocity profile of the hydrogenic species is predicted to be monotonic, from measurements of the impurity toroidal velocity, consistent with the anomalous radial diffusion of toroidal momentum. This supports a neoclassical calculation of the radial electric field for near-balanced beam injection. In supershot plasmas [Phys. Rev. Lett. 58, 1004 (1987)], a well structure in the radial electric field profile is found in the enhanced confinement region. An associated shear layer separates the core, where the local confine.
Generation-Recombination Current in the Emitter-Base Junction of AlGaAs/GaAs HBTs

The influence of an undoped spacer layer in the emitter-base junction on HBT characteristics was investigated experimentally and theoretically. The ideality factor n of the base current increased from 1.1 to 1.9 for an undoped spacer-layer thickness of between 25 and 150Å. This indicates that the increment of the depletion-layer thickness in GaAs base-side produces a g-r current enhancement in the EB junction. The theoretical analysis also suggests these tendencies. The calculation shows that the n value variation is caused by a one-sided distribution of carriers due to an energy barrier at the heterojunction.