Miracle-dz/UniFAR-FTUs huggingface dataset:
Cultivating mathematical thinking with Scratch, or approaching programming via geometry?

The 21st, century learning skills constitute a necessity in our rapidly changing times. Student activation and their occupation with constructions which have a meaning for them, and which they can share out, contribute to the development of critical thinking. The exploitation of programming and the use of code, help in the understanding of mathematical concepts and the cultivation of mathematical thinking through the process of trial, in addition to the correction of errors of the code, through visualization. Distance learning, synchronous and asynchronous, combined with experiential learning, contribute to the co-construction of knowledge. This paper presents how the SCRATCH application was used in teaching of geometry in primary education in the context of blended learning.
High-Gain Wideband and Superdirective Electronically-Beam-Switchable Antenna for Smart Communication Objects

This paper proposes the design of a high-gain, wideband, directive, and compact circular array composed of 5 symmetrical radiating elements (1 fed and 4 parasitic elements). The possibility to implement an electronically beam-switching capability over the horizontal plane is studied. Thanks to the superdirectivity principle, the proposed closely spaced parasitic antenna array achieves a maximum gain of 10 dBi steered in four directions on the horizontal plane and a minimum gain of 9 dBi in the whole horizontal plane. The proposed antenna achieves a stable gain > 9dBi in the frequency band 758–803 MHz, which is interesting for sub-GHz 5G applications.
Phase Reconfiguration via SIW Structures Filled with Liquid Metal

This paper presents substrate integrated waveguide (SIW) phase shifter that can be reconfigured using liquid metal. The phase shifter is developed to be used for antenna applications. This digital phase shifter incorporates a series of holes which can be filled or emptied of liquid metal, enabling us to add or remove via connections dynamically, on-the-fly. We employ a switched line approach to achieve course phase control along with reactive loading to achieve fine steps of phase control. By employing both forms of reconfiguration in unison the proposed phase shifter is able to deliver a phase shift of up to 180° in steps of 10°. The proposed phase shifter operates at 10 GHz and exhibits a measured insertion loss of less than 2.3 dB over its entire operating band.
Ka-band Mechanically Steered Phase Shifter for Satellite User Terminals

In this paper, a mechanically steered phase shifter with planar structure is presented for Ka-band satellite user terminals. The proposed phase shifter is composed of a power divider based on ridge gap-waveguide (RGW) and a phase-shifting section based on double-layer groove gap-waveguide (GGW) with a shared rotatable plate. The simulated results show that the phase shifter could achieve 13.6% impedance bandwidth with the reflection coefficient below -15dB. Meanwhile, the insertion losses of all output ports fluctuate around 6 ± 0.5dB and the phase differences remain stably linear over the whole operational bandwidth.
Seedless Pumpkin Vegetable Production Using Gibberellic Acid (GA3) As Plant Hormone and Genetically Modified Technique

Pumpkin is one of the most important vegetables that meet the requirements of healthy nutrition. It is a tasty and valuable vegetable crop, containing a lot of biologically active substances and significant for dietary qualities. The study was carried out to investigate the seedless effect of GA3 150ppm on pumpkin by applying injection method and biochemical as well as nutritional quality. Current results showed that fruit weight was higher in the GA3 treated fruit than in control fruit. Moreover, Seed number and per seed weight were higher in the control than the GA3 treated pumpkin. However, 96.9% seedless pumpkin was found by the treatment of GA3 compared to the control. Biochemical content like glucose, inverted sugar and fructose content were found to be higher in the GA3 treated pumpkin than the control. In addition, potassium and calcium content were higher in the GA3 treated fruit than in control. Therefore present results showed that seedless pumpkin production can be possible by using GA3 150ppm.
High-Directivity Ultra-Sparse Antenna Arrays Using Multielement Metagratings

We present a rigorous analytical model utilized to design highly-sparse antenna arrays, taking advantage of the recent concept of metagratings (MGs). The proposed semian-alytical methodology, avoiding full-wave optimization, enables replacement of the generally-large number of active radiating elements with passive capacitively-loaded wires (meta-atoms), without sacrificing array directivity. Contrary to common techniques to dilute arrays, relying mostly on optimization of active element distribution and excitation, our modular solution utilizes a standard array configuration with linearly-phased elements; grating-lobe suppression is achieved by proper engineering of the passive MG, harnessing Floquet-Bloch formalism to control power partition into diffraction orders. To facilitate dramatic dilution and comply with printed-circuit-board (PCB) design requirements, we extend our previous work, enabling inclusion of multiple meta-atoms per period within a multilayered dielectric substrate. This concept, verified via full-wave simulations, is expected to facilitate the development of low-cost, planar, low-loss, and highly-directive antenna systems for future cellular and satellite communication.
Key Sharing Protocol Using Exchange by Integers over Public Noiseless Channels Between Users that Provides Security without Cryptographic Assumptions

Recently, we proposed similar key sharing protocol executed over the public noiseless channels and also without any cryptographic assumptions. Exchange by matrices was believed to have superior performance in that protocol. In the current paper, the matrix exchange was replaced by integer exchange over the same channels. It requires to apply additional subprotocols to make both legitimate and eavesdropper channels worse. A replacing matrices by integers allowed us to derive some probability relations theoretically instead of relying on the simulation results only in our previous paper. Moreover, the use of the integers in place of matrices requires less traffic over channels between legitimate correspondents. The performance evaluation of the proposed protocol in terms of the reliability and security is presented as well.
Using the Convolutional Neuron Network for Target Localization and Wall Characterization in the Through the Wall Imaging Problem

This paper investigates the Through the Wall Imaging (TWI) problem via machine learning. To solve the TWI problem in presence of the wall, a Convolution Neuron Network (CNN) is proposed. The detection of the scatterers behind the wall when there is a strong reflection from the front wall is very challenging. Several microwave imaging algorithms have been introduced to extract the unknown parameters of the wall and mitigate the wall clutter to predict the location of the target. This process is very time-consuming even though it has accurate results. In this paper, we developed a method for exploiting the complex information for the TWI problem by using a CNN that accepts complex numbers from the receiver to predict wall thickness, material, and location of the target behind the wall at the same time. We show that our proposed model can predict these parameters with an accuracy of 92.6%.
Design of an E-Band 1-Bit Reconfigurable Reflectarray Antenna Using PIN Diodes

A 1-bit reconfigurable reflectarray antenna using PIN diodes is presented for 71-76GHz millimeter-wave communication applications. Based on the method of polarization conversion, the 0°/180° element phase is accurately realized by loading 2 PINs on each element in order to overcome the unstable parameters of PIN in E-band. A square aperture reflectarray consisting of $16\times 16$ elements is then designed and analyzed. Full-wave simulation results demonstrate that the gain of the antenna is 17.1dBi, and the beam scanning angle can cover 45°.
Fast and furious dynamo action in the anisotropic dynamo

Abstract In the limit of large magnetic Reynolds numbers, it is shown that a smooth differential rotation can lead to fast dynamo action, provided that the electrical conductivity or magnetic permeability is anisotropic. If the shear is infinite, for example between two rotating solid bodies, the anisotropic dynamo becomes furious, meaning that the magnetic growth rate increases toward infinity with an increasing magnetic Reynolds number.
Enhanced Data Throughput Using 26 GHz Band Beam-Steered Antenna for 5G Systems

A high gain (20 dBi) Leaky-Wave Antenna (LWA) is presented at 26 GHz with beam steering capabilities (44°) for high data throughput in millimeter-wave (mm-wave) 5G systems. A tunable phase shifting High Impedance Surface (HIS) exhibiting low loss $(< 0.1\ \ \text{dB})$, is employed for the antenna's beam steering. A Piezo-Electric Actuator (PEA) is employed to electromechanically tune the HIS. The employed PEA exhibited fast (milliseconds) and continuous displacement variation of up to 500 µm. The LWA has been demonstrated by deploying it within a 5G testbed operating within the 26GHz band. It was observed that the channel performance can significantly be improved utilizing the beam steering capability of the antenna in the case when the line-of-sight (LOS) is blocked by an obstacle.
Multi-track recordings of choral singers: Development and validation of a method to identify activities and interaction in the choral voice, based on recordings of the individual singers

Methods to identify and explore actions of the individual choir singer are scarce and have rarely been systematically described. The aim of this study was to find, develop and evaluate a visualauditive method for collecting and analysing data from individual choir-singers. Multi-track recordings were performed and analysed. Two voice teachers and singers in a mixed high-schoolchoir with hand-held/head-mounted microphones were recorded on individual tracks. With the help of a computer software, the recordings were transferred for visual analysis. The detailedactions of the singers were possible to identify and thus also actions indicating informal leadership could be identified. This method was concluded to be a useful instrument for collecting, comparing and analysing data from individual singers. Accordingly, the method is found to be valid and productive in choir research, the results of which might provide valuable knowledge of cooperation between choral singers, thus serving as a tool in choir conductors’ everyday work.
Joint PP, PS1, and PS2 AVA Inversion of HTI Media

Sedimentary strata formed by orientational vertical fractures are approximately equivalent to transversely isotropic media with a horizontal symmetry axis (HTI). Parameter inversion for the isotropic background and fracture parameters can provide valuable information for predicting fractured reservoirs. Following Bakulin’s modeling theory, we parameterized the HTI medium with the first- and second-order Lamé parameters of the isotropic background, host rock density, fracture density, and fracture azimuth. We calculated the fracture azimuth and separated split shear waves using the Alford rotation. Based on the exact reflection coefficients, we develop a joint P-to-P reflected wave (PP), PS1, and PS2 amplitude variation with angle (AVA) inversion method in the depth domain by using the second-order Levenberg–Marquardt (LM) algorithm to invert the remaining four parameters. Numerical model tests revealed that our method was more accurate compared to the traditional LM method and works for both weak/strong contrasts and anisotropy magnitudes. We used real data from the walkaway vertical seismic profiling (VSP) as an example to propose a set of strategies, thereby improving the practicality of our inversion method. To protect the fracture information contained in the wavefields, we adopted vector-feature-preserving data processing procedures to preprocess the field VSP data and separate PP, PS1, and PS2 reflections. We utilized P-wave first breaks to successfully discriminate and match these three wave modes from the same fractured formation in the depth domain; these were subsequently transformed to AVA gathers with ray tracing. We synthetically incorporated the time delays and layer velocities to build the initial models and to constrain the inversion process.
Design of Tunable Millimetre-wave Pass-Band FSS Unit-Cell Loaded with GaAs Air-Bridged Schottky Diodes

In this paper, a tunable passband Frequency Selective Surface (FSS) loaded with GaAs air-bridged Schottky diode is presented, appropriate for beam-steering and beam-scanning applications. The proposed structure allows the simultaneous control of both phase and magnitude of the electromagnetic waves transmitted by each unit cell through the introduction of tuning, which is achieved by the Schottky diode technology. The obtained tuning bandwidth lies within 7.04-9.42 GHz, with a central frequency of 40.5 GHz, the insertion loss has an average value around 1.47dB and the phase shift of the single layer is equal to 101°. This FSS can be used as the building block for the development of higher-order tunable FSS filters or for transmitarrays able to electronically steer the direction of an incident beam and find applications in future 5G/6G and satellite communication systems. In this work, a multilayer tunable unit cell is reported which achieves a phase shift higher than 360°, with average insertion losses within 5-11dB and a 3dB bandwidth equal to 3.5GHz.
Highly Transparent Fully Metallic 1-Bit Coding Metasurfaces for Near-Field Transformation

This paper presents a low-cost coded metallic metasurface (CMM) to manipulate electromagnetic waves with a 1-bit fully metallic meta-atoms. The proposed CMM provides polarization-independent transmission for any code sequence at a low cost with a lightweight structure. The concept is validated with four different CMMs, which were characterized through full-wave numerical analysis. Each CMM can split the boresight beam into symmetric multi-beams in directions predicted through analytical formulations. This investigation reveals the significant potentialities of CMM as a building block to design multi-beam antenna systems.
Fast Array Diagnosis Based on Measured Complex Array Signals with Short Measurement Distance

Fast array diagnosis method is of great importance for ensuring reliable array performances in the fifth generation (5G) communication systems. In this paper, a fast array diagnosis method is presented for antenna arrays composed of several subarrays. The objective is to detect the failures based on the measured complex array signals in short measurement distance. A single probe is required to record the array response in the near-field of the array. All the array elements are excited simultaneously, and only phase shift states of 0° and 180° are required in the measurements. For a base station (BS) antenna array with $N$ subarrays, $N+1$ measurements are required, resulting in a fast diagnosis process. Finally, the proposed method was validated in an antenna array composed of 4 subarrays with 3 antenna elements in each subarray and successful diagnosis results (for both the whole subarray and single antenna element failure cases) can be observed.
Damped Chirp Mixture Estimation Via Nonlinear Bayesian Regression

Estimating mixtures of damped chirp sinusoids in noise is a problem that affects audio analysis, coding, and synthesis applications. Phase-based non-stationary parameter estimators assume that sinusoids can be resolved in the Fourier transform domain, whereas high-resolution methods estimate superimposed components with accuracy close to the theoretical limits, but only for sinusoids with constant frequencies. We present a new method for estimating the parameters of superimposed damped chirps that has an accuracy competitive with existing non-stationary estimators but also has a high-resolution like subspace techniques. After providing the analytical expression for a Gaussian-windowed damped chirp signal's Fourier transform, we propose an efficient variational EM algorithm for nonlinear Bayesian regression that jointly estimates the amplitudes, phases, frequencies, chirp rates, and decay rates of multiple non-stationary components that may be obfuscated under the same local maximum in the frequency spectrum. Quantitative results show that the new method not only has an estimation accuracy that is close to the Cramér-Rao bound, but also a high resolution that outperforms the state-of-the-art.
Ionic conductivity and ion transport mechanisms of solid‐state lithium‐ion battery electrolytes: A review

This review article deals with the ionic conductivity of solid‐state electrolytes for lithium batteries. It has discussed the mechanisms of ion conduction in ceramics, polymers, and ceramic‐polymer composite electrolytes. In ceramic electrolytes, ion transport is accomplished with mobile point defects in a crystal. Li+ ions migrate mainly via the vacancy mechanism, interstitial mechanism, or interstitial‐substitutional exchange mechanism. In solid polymer electrolytes, Li+ ions are transported mainly via the segment motion, ion hopping (Grotthuss mechanism), or vehicle mechanism (mass diffusion). This study has also introduced various electrolyte materials including perovskite oxides, garnet oxides, sodium superionic conductors, phosphates, sulfides, halides, cross‐linked polymers, block‐copolymers, metal‐organic frameworks, covalent organic frameworks, as well as ceramic‐polymer composites. In addition, it has highlighted some strategies to improve the ionic conductivity of solid‐state electrolytes, such as doping, defect engineering, microstructure tuning, and interface modification.
A marine probiotic treatment against the bacterial pathogen Vibrio coralliilyticus to improve the performance of Pacific (Crassostrea gigas) and Kumamoto (C. sikamea) oyster larvae

Oyster larvae reared in hatcheries on the U.S. West coast often experience severe Vibrio coralliilyticus-related mortalities early in their development. Current treatment options for these molluscs are either not available or feasible; however, for decades, probiotics have been successfully used in finfish and crustacean shellfish culture. Consequently, the objectives of this work were to 1) isolate marine bacteria from oysters and evaluate their protective activity against Vibrio coralliilyticus infection of Pacific oyster (Crassostrea gigas) larvae, and 2) to determine the long-term effects of probiotic additions on growth and metamorphosis of larval Pacific and Kumamoto oysters (C. sikamea). A combination of three probiotic strains applied once 24 hours post-fertilization was more effective in improving survival of larval C. gigas exposed to lethal concentrations of V. coralliilyticus strain RE22, compared with separate additions of individual probiotics. In addition, a single application of the probiotic combination to one-day-old larvae increased the larval metamorphosis success of C. sikamea and both the Midori and Myiagi stocks of C. gigas. These results suggest that probiotics are effective at preventing bacterial infections and can significantly improve performance of oyster larvae, using a single application early in their development. Highlights • A combination of marine bacteria improved survival of Pacific oyster larvae exposed to virulent V. coralliilyticus. • Metamorphosis was increased after adding a single dose of probiotics to one-day-old larvae. • Repetitive dosing after each water change was not superior to a single dose one day post egg-fertilization. • A single dose of the probiotic combination resulted in larger size on day 12.
Prenatal inflammation perturbs murine fetal hematopoietic development and causes persistent changes to postnatal immunity

Adult hematopoietic stem and progenitor cells (HSPCs) respond directly to inflammation and infection, resulting in both acute and persistent changes to quiescence, mobilization, and differentiation. Here we show that fetal HSPCs respond to prenatal inflammation in utero, and that the fetal response shapes postnatal hematopoiesis and immunity. Heterogenous fetal HSPCs showed divergent responses to maternal immune activation (MIA), including changes in quiescence, expansion, and lineage-biased output. Single cell transcriptomic analysis of fetal HSPCs in response to MIA revealed specific upregulation of inflammatory gene profiles in discrete, transient HSC populations, that propagated expansion of lymphoid-biased progenitors. Beyond fetal development, MIA caused the inappropriate expansion and persistence of fetal lymphoid-biased progenitors postnatally, concomitant with increased cellularity and hyperresponsiveness of fetal-derived innate-like lymphocytes. Our investigation demonstrates how inflammation in utero can direct the trajectory of output and function of fetal-derived immune cells by reshaping fetal HSC establishment.
Business Education and Employability - Are they Strange Bedfellows?

Business education is education in the basic principles and practices of industry and commerce, imparted in a business school/college/university as a part of formal education. Employability consists of a set of skills, knowledge, understanding and personal attributes that make persons more likely to choose and secure occupations in which they can be satisfied and successful. There exists a strong disconnect between business education and employability. Unfortunately, 'qualification' which is measured in terms of academic degrees and grades are not matching the 'competencies' defined and determined by the employment market. In this fast changing business world, the shelf-life of competencies (knowledge, attitudes, skills, habits and values) is always short-lived and as such the existing knowledge suddenly becomes outdated, skills obsolete, attitude untenable, values unpardonable and learning habits unsustainable. Previous research studies revealed a set of thirty-one factors determining the employability potential of graduates and post-graduates. Employability is not just confined to the process of getting the offer of employment in campus recruitment drives but extends to the workplace and also includes self-employment avenues. In this paper, an attempt is made to raise major implications and provide some directions for enhancing the employability potential of business education graduates and post-graduates. Organizations increasingly seem to ask for highly competent, talented, committed, multi-skilled and flexible employees. Proper training in various non-academic/technical skills, if systematically provided to students alongside their academic study, would eventually result in the better employability of students. It is the responsibility and commitment of all stakeholders to bring about a 'happy marriage' between business education and employability with the help of purposeful, meaningful and effective industry-academia interface. Business education and employability are just like two sides of the same coin and therefore cannot afford to behave like strange bedfellows.