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The demand for accurate health status assessment of bearings in rotating electrical machines is rising. However, traditional fault diagnosis methods based on deep learning are not effective in efficiently and intelligently determining the health condition of the bearings and also requires large memory, hence constraining their use in low-cost microcontrollers. In this work, combination of short time Fourier transform (STFT) with Ostu's threshold method and MobileNet-V2 with U-Net (MV2UNet) is proposed for rolling bearing fault health status. The proposed method obtains the STFT images of the raw vibration signals from the laboratory experimental setup. Then the Ostu's threshold method is used to make the labels for STFT images. Finally, the proposed method is trained with these labelled images to detect the health status of each bearing fault. The proposed model achieved the Dice coefficient is 0.9834 and the intersection over union is 0.9479. The main advantage of the proposed model has low memory requirements, which makes it well-suited for implementation in affordable hardware devices like microcontrollers. Finally, the proposed method result is compared with U-Net, DeepLabV3+ with MobileNet-V2 and DeepLabV3+ with ResNet-50. [ABSTRACT FROM AUTHOR]

Separating speech is a challenging area of research, especially when trying to separate the desired source from its combination. Deep learning has arisen as a promising solution, surpassing traditional methods. While prior research has mainly focused on the magnitude, log-magnitude, or a combination of the magnitude and phase portions, a new approach using the Short-time Fourier Transform (STFT), and a deep Convolutional Neural Network named U-NET has been proposed. This method, unlike others, considers both the real and imaginary components for decomposition. During the training stage, the mixed time-domain signal undergoes a transformation into a frequency-domain signal by using STFT, producing a mixed complex spectrogram. The spectrogram's real and imaginary parts are then divided and combined into a single matrix. The newly formed matrix is fed through U-NET to extract the source components. The same process is repeated at testing. The resulting concatenated matrix for the mixed test signal is passed through the saved model to generate two enhanced concatenated matrices for each source. These matrices are then transformed back into time-domain signals using inverse STFT by extracting the magnitude and phase. The proposed approach has been evaluated using the GRID audio visual corpuses, with results showing improved quality and intelligibility compared to the existing methods, as demonstrated by objective measurement metrics. [ABSTRACT FROM AUTHOR]

Pulsed electrical field (PEF) treatment with 1 kJ/kg and 3 kJ/kg of energies was applied to yellow- and purple-fleshed potatoes before frying (180 °C for 2 min). The effects of PEF on oil content, colour and bioactive compounds were investigated. Significant oil reductions were observed for PEF-treated potatoes, ≥ 20% for yellow- and ≥ 24% for purple-fleshed potatoes, and this was also confirmed in the Fourier transform infrared (FTIR) graph. PEF-treated potatoes had significantly higher phenolic compounds and antioxidant activity than those of untreated samples. Moreover, although the frying reduced total monomeric anthocyanin (TMA) contents of the purple-fleshed potato samples compared to raw potato samples (not PEF-treated and not fried), PEF-treated samples had significantly higher TMA than the untreated (not PEF-treated but fried) samples. Raw samples and fried samples were separated according to PC1 (principal component 1) in chemometric analysis, and fried samples with and without PEF treatment were also separated according to PC2 (principal component 2). When PLS (partial least squares) regression graphs were examined, it was revealed that there was a very good correlation between the oil content and redness (a*) values calculated and estimated by FTIR spectroscopy. Our study showed that PEF treatment could be succesfully used for different varieties of potato before frying. [ABSTRACT FROM AUTHOR]

Owing to the irregular distribution of point clouds in 3D space, effectively compressing the point cloud is still challenging. Recently, numerous compression methods have been developed with outstanding performance for the compression of geometry information of point clouds. On the contrary, limited explorations have been devoted to point cloud attribute compression (PCAC). Thus, this paper focuses on the study of point cloud attribute compression by applying geometric information as decoded prior information. In this paper, a novel cluster-based two-branch framework for PCAC is proposed. Specifically, the point cloud is first divided into adaptive un-overlapped blocks via K-means according to geometric information, which enables an efficient local representation of the point cloud. Then, we split the point cloud attributes into two components(Block-Mean component and Block-Residual component) and compressed them separately through the designed block-based dual branches. For the Block-Mean component, we design a prediction scheme to remove the inter-block attribute redundancy. The Block-Residual component is further compacted by applying a designed graph Fourier transform generated by geometric prior information. Then, the transform coefficients are encoded using an arithmetic coder. Extensive experimental results demonstrate that the proposed point cloud attribute compression scheme outperforms existing attribute compression schemes in terms of both objective quality and subjective quality. [ABSTRACT FROM AUTHOR]

In this study, an anionic dye, Reactive Black 5 (RB5), was subjected to sonophotocatalytic treatment process with the aim of establishing the effectiveness of the prepared ZnO incorporated activated red mud (ZnO/ARM) as a viable sonophotocatalyst. ZnO/ARM was prepared by impregnation method at different weight ratios (0.25:1, 0.5:1, 0.75:1 and 1:1) with the ZnO/ARM at weight ratio of 0.75:1 proving to be the best sonophotocatalyst. The prepared sonophotocatalysts were characterized by X-ray diffractometer for crystal phase studies, Brunauer–Emmett–Teller for surface area studies, Fourier transform infrared for surface functional groups studies, SEM–EDX for surface morphological and elemental studies, diffuse reflectance spectroscopy and photoluminescence for sonophotocatalyst band-gap studies while parametric and kinetic studies of the removal of RB5 from the simulated wastewater were conducted to confirm its effectiveness under simultaneous application of a transducer bath-type sonicator (35 kHz) and a UV-C (254 nm) lamp. The influence of the solution pH, concentration and catalyst dosage were manipulated throughout this study to investigate the sonophotodegradation kinetics and synergistic effects on the RB5 degradation. Experimental results confirmed that the sonophotocatalytic degradation rate of 20 ppm RB5 was most effective under acidic medium (66.7%) as compared to alkaline medium (46.1%) due to an excess of positive charge in the ZnO/ARM surface which favours a strong electrostatic interaction with SO3− groups of the dye resulting in a higher degradation rate (0.0156 min−1). Under alkaline conditions, the catalytic activity of ZnO/ARM was attenuated by the higher negative charge which promoted the repulsion of the dye from ZnO/ARM surfaces leading to a lower degradation rate of 0.01 min−1. The accelerated photo induced electron–hole transfer and separation, decreased recombination rate and band energy matching, enhancing the photocatalytic performance of ZnO/ARM composite. [ABSTRACT FROM AUTHOR]

This paper is devoted to the study of the following fourth order Schrödinger equation with mixed dispersion on M N , an N-dimensional Cartan-Hadamard manifold. Namely we consider 4NLS i ∂ t ψ = - Δ M 2 ψ + β Δ M ψ + λ | ψ | 2 σ ψ in R × M , ψ (0 , ·) = ψ 0 ∈ X , where β ≥ 0 , λ = { - 1 , 1 } , 0 < σ < 4 / (N - 4) + , Δ M is the Laplace-Beltrami operator on M and X = L 2 (M) or X = H 2 (M) . At first, we focus on the case where M is the hyperbolic space H N . Using the fact that there exists a Fourier transform on this space, we prove the existence of a global solution to (4NLS) as well as scattering for small initial data provided that N ≥ 4 and 0 < σ < 4 / N if X = L 2 (H N) or 0 < σ < 4 / (N - 4) + if X = H 2 (H N) . Next, we obtained weighted Strichartz estimates for radial solutions to (4NLS) on a large class of rotationally symmetric manifolds by adapting the method of Banica and Duyckaerts (Dyn. Partial Differ. Equ., 07). Finally, we give a blow-up result for a rotationally symmetric manifold relying on a localized virial argument. [ABSTRACT FROM AUTHOR]

A novel UV-curable rosin-based resin, named as DHTM, was synthesized through a Michael addition reaction involving a derivative of natural rosin (dehydroabietylamine, DHAA) and trimethylolpropane triacrylate (TMPTA). The reaction, conducted at a low temperature (50 °C) without solvents, achieved a high conversion rate exceeding 95%. Structural analyses via Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR), and liquid chromatography-orthogonal time-of-flight mass spectrometry (LC-OTOF-MS) confirmed the chemical composition of DHTM. Subsequently, a multifunctional UV resin was formulated by combining DHTM with the diluent 4-acryloylmorpholine (ACMO) and cured under UV light. The resulting resin exhibited excellent thermal, mechanical, and microscopic properties, including notable crosslinking density, tensile strength, and adhesion. The addition of ACMO contributed to a smoother resin surface, achieving a higher crosslinking density of 57.04 × 103 mol/m3. In conclusion, the developed UV-curable rosin-based resins exhibit significant potential for applications in UV-curable materials, such as 3D printing and coatings. [ABSTRACT FROM AUTHOR]

The concepts of multiresolution analysis (MRA) and wavelets in Sobolev space over local fields of positive characteristic ( H s (K) ) are developed by Pathak and Singh [9]. In this paper, we constructed wavelet packets in Sobolev space H s (K) and derived their orthogonality at each level. By using convolution theory, an example of wavelet packets in H s (K) is presented [ABSTRACT FROM AUTHOR]

When subjected to swift heavy ion (SHI) irradiation, a lattice acquires sufficient energy to induce desirable flaws in the material. In this study, the physiochemical properties of Sn-doped V2O5 (SVO) synthesized by a sol–gel process were thoroughly examined following irradiation with Ni+11 ions at 150 MeV energy and fluence of 2.51 × 1011 ions/cm2. The successful doping of Sn in V2O5 was confirmed by an increase in tensile strain, as revealed by the x-ray diffraction (XRD) spectrum, and the presence of characteristic peaks of constituent elements detected in the energy-dispersive x-ray (EDX) spectrum. Atomic force microscopy (AFM) and field-emission scanning microscopy (FESEM) images revealed an increase in surface roughness and transformation to an amorphous state, respectively. The Tauc plot indicated an increase in the electronic bandgap post-irradiation. Fourier transform infrared (FTIR) spectroscopy analysis revealed a peak shift in the fingerprint region indicating a change in the vibrational energy of the involved molecular bonds. These findings highlight the potential of SHI irradiation for the tuning of material properties, paving the way for a wide range of functional applications of the material. [ABSTRACT FROM AUTHOR]

This study empirically investigated the influence of freeze–thaw cycling on the dynamic splitting tensile properties of steel fiber reinforced concrete (SFRC). Brazilian disc splitting tests were conducted using four loading rates (0.002, 0.02, 0.2, and 2 mm/s) on specimens with four steel fiber contents (0%, 0.6%, 1.2%, and 1.8%) subjected to 0 and 50 freeze–thaw cycles. The dynamic splitting tensile damage characteristics were evaluated using acoustic emission (AE) parameter analysis and Fourier transform spectral analysis. The results quantified using the freeze–thaw damage factor defined in this paper indicate that the degree of damage to SFRC caused by freeze–thaw cycling was aggravated with increasing loading rate but mitigated by increasing fiber content. The percentage of low-frequency AE signals produced by the SFRC specimens during loading decreased with increasing loading rate, whereas that of high-frequency AE signals increased. Freeze–thaw action had little effect on the crack types observed during the early and middle stages of the loading process; however, the primary crack type observed during the later stage of loading changed from shear to tensile after the SFRC specimens were subjected to freeze–thaw cycling. Notably, the results of this study indicate that the freeze–thaw damage to SFRC reduces AE signal activity at low frequencies. [ABSTRACT FROM AUTHOR]

Microplastic ingestion by marine organisms presents a challenge to both ecosystem functioning and human health. We characterized microplastic abundance, shape, size, and polymer types ingested by the West African mangrove oyster, Crassostrea tulipa (Lamarck, 1819) sampled from estuaries and lagoons from the Gambia, Sierra Leone, Ghana, Benin, and Nigeria using optical microscopy and Fourier transform infrared (FTIR) techniques. A total of 780 microplastics were isolated in the whole tissues of the 250 oysters (n = 50 oysters per country). The abundance and distribution of microplastics in the oysters followed the pattern: the Gambia > Ghana > Sierra Leone > Nigeria > Benin. The Tanbi wetlands in the Gambia recorded the highest average of 10.50 ± 6.69 per oyster while the Ouidah lagoon in Benin recorded the lowest average of 1.80 ± 1.90 per oyster. Overall, microplastic numbers varied significantly (p < 0.05) among the five countries. Microfibers, particularly those within 1001–5000 μm size, dominated the total microplastic count with a few fragments and films. No spherical microplastics were isolated in the oysters. In the Sierra Leone and Benin oysters, fragments and films were absent in the samples. Microplastic between the 1001 and 5000 μm size class dominated the counts, followed by 501–1000 μm, 101–500 μm, and 51–100 μm. Five polymer groups namely polyethylene, polyester, nylon, polypropylene, and polyamide were identified across the five countries, with polyethylene occurring in oysters from all five countries and polyester occurring in all but the oysters from Nigeria. This diversity of polymers suggests varied sources of microplastics ingested by the studied oysters. The absence of microspheres across the five supports findings from other studies that they are the least ingested and highly egested by the oysters. [ABSTRACT FROM AUTHOR]

Crystalline zeolites have high acidity but limited utility due to microporosity, whereas mesoporous amorphous aluminosilicates offer better porosity but lack sufficient acidity. In this work, we investigated defect engineering to fine-tune the acidity of amorphous acidic aluminosilicates (AAS). Here we introduced oxygen vacancies in AAS to synthesize defective acidic aluminosilicates (D-AAS). 1H, 27Al, and 17O solid-state nuclear magnetic resonance (NMR) studies indicated that defects induced localized structural changes around the acidic sites, thereby modifying their acidity. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy studies substantiated that oxygen vacancies alter the chemical environment of Brønsted acidic sites of AAS. The effect of defect creation in AAS on its acidity and catalytic behavior was demonstrated using four different acid-catalyzed reactions namely, styrene oxide ring opening, vesidryl synthesis, Friedel-Crafts alkylation, and jasminaldehyde synthesis. The defects played a role in activating reactants during AAS-catalyzed reactions, enhancing the overall catalytic process. This was supported by in-situ FTIR, which provided insights into the molecular-level reaction mechanism and the role of defects in reactant activation. This study demonstrates defect engineering as a promising approach to fine-tune acidity in amorphous aluminosilicates, bridging the porosity and acidity gaps between mesoporous amorphous aluminosilicates and crystalline zeolites. Is it possible to fine-tune the acidity of amorphous aluminosilicates? Here authors use defect engineering as a method to optimize acidity, bridging the porosity and acidity gaps between amorphous aluminosilicates and crystalline zeolites. [ABSTRACT FROM AUTHOR]

The precise separation of multicomponent signals encounters numerous challenges due to the complexity of signals and widespread interference. Synchrosqueezing Transform (SST) is one of the important technologies for improving the accurate separation of multicomponent signals, but it faces challenges in terms of the difficulty and effectiveness of squeezing. This paper introduces a multicomponent signal separation method based on innovative Fractional Synchrosqueezing Transform (FrSST). FrSST rearranges along the fractional frequency axis, improving the accuracy of time–frequency ridges and, consequently, enhancing the precision of multicomponent signal separation. In the signal reconstruction process, chirp multiplication and energy rearrangement compensate for chirp bases' effects, boosting energy concentration and reconstruction potential. Utilizing improved ridges from FrSST ensures effective signal reconstruction. Simulation comparisons demonstrate that, with varying SNRs from − 5 to 15 dB, the reconstructed components based on FrSST exhibit favorable approximation to the original signal components. Furthermore, as the sample size increases, the proposed algorithm shows satisfactory computational efficiency. [ABSTRACT FROM AUTHOR]

The elliptic Fourier transform is a common method of describing the shape of objects by an unique sequence of coefficients that allow comparing the shapes by mathematical methods. However, the raw coefficients contain unnecessary data unrelated to the shape, which does not provide a correct comparison. For this reason, the coefficients are normalized. This removes some of the superfluous data, but leaves information about mirror symmetry and the order in which the contour vertices are declared, that are encoded in the signs of the coefficients. This also interferes with shape comparison. The paper describes an algorithm for harmonizing the coefficients, leveling the influence of the information mentioned. Based on the example of attachment organs of monogeneans, the advantages of using harmonized coefficients for comparing the shapes of biological structures are shown. [ABSTRACT FROM AUTHOR]

Undoped, Fe, Sn doped and Fe/Sn co-doped copper oxides are prepared by precipitation synthesis. X-ray diffraction confirmed that the all synthesized powders show a monoclinic main CuO phase. The insertion of Fe or/and Sn within the CuO matrix moderately affects the preferential growth direction. Basically Fourier Transform Infrared (FTIR) confirmed about functional group and their vibrations in the CuO samples. The reflectance of the undoped sample is higher than that of the other samples. Compared to undoped CuO, the doped and co-doped NPs exhibit red-shifted gap energy. Indeed, the Fe-doped, and Sn-doped CuO NPs, exhibit a slight decrease of gap energy (1.47, 1.45 eV respectively) compared to the undoped CuO (1.49 eV), while the Fe/Sn co-doped sample has a lower gap energy of 1.06 eV. Additionally, the antibacterial efficiencies of the all-synthesized samples are tested against Staphyloccus species. Doped and undoped CuO nanopowders show important antibacterial activity on tested bacteria with MICs values ranged between 0.039 to 1.25 mg/ml. Minimum Inhibitory Concentration value of 0.039 mg/ml was obtained with Fe-doped CuO NPs (CuO:Fe NPs) against S.aureus ATCC33591, whereas the highest MIC value of 1.25 mg/ml was obtained with CuO:Sn nanopowder against the strain S. epidermidis, which was the most resistant strain. Moreover, all CuO NPs, except CuO:Fe/Sn showed important anti-adhesive and antibacterial activities against S. epidermidis when used as pellets. This was confirmed either by cell counts using the determination of CFU/ml of bacterial suspension inside the hole, or by using fluorescence microscopy. [ABSTRACT FROM AUTHOR]

We consider the linear elasticity system for a body coated with a thin elastic layer. The effect of the thin layer on that body can be described through an impedance operator linking the displacement and the traction on the interface. This operator cannot be in general explicitly computed for an arbitrary shape. In this paper, we consider the case of a linear elastic slab with Hooke's law. We compute by the Fourier transform the exact symbol of the impedance operator and prove that it is a pseudodifferential operator of order one. Then, we give a Padé-like approximation at order three (with respect to the thickness of the layer) for the impedance operator. The pattern of this approximation will be a helpful guide for approximating the impedance operator for a body whose boundary has nonzero curvature. [ABSTRACT FROM AUTHOR]

Disproportionation of alcohols to the corresponding alkanes and aldehydes/ketones is an important reaction, especially for biomass valorisation. Previously, we reported for the first time that hydroiodic acid can be used as an efficient catalyst for the alcohol disproportionation reaction, and the interconversion between hydroiodic acid and iodine is the key step for hydrogen transfer. As a continuation of our previous work, this work mainly focused on the mechanistic study involved and studied the difference between hydroiodic acid or molecular iodine as the catalyst for the disproportionation of alcohols. Density Functional Theoretical calculation indicated the oxidation step was a synergistic reaction process through the iodine effect on oxygen-hydrogen bond, which was proved by the characteristic oxygen-iodine bond captured by in-situ Attenuated Total Reflectance Fourier Transform Infrared. A non-polar solvent was preferable for the reaction with iodine. Addition of small amount of water was shown to be beneficial for the reaction, because water promoted Brønsted acidity of hydroiodic acid and accelerated the rate-determining step. Finally, we showed that the system was also applicable to various benzyl, allyl alcohols, and some heterocyclic alcohols. [ABSTRACT FROM AUTHOR]

Purpose: When golfing, using a suitable club is crucial to swinging as desired and achieving high scores. Various studies have analyzed golf clubs and swings to select an appropriate club. However, only a few have considered how variations in the club's physical characteristics change the swing. This study applied the short-time Fourier transform (STFT) to torque data obtained during swings to elucidate how the variation in shaft mass affects the swing, and verified the role of the torque by comparing it with the variation in shaft tip velocity. Methods: First, we used a motion capture system to record a golfer's swing with varied shaft masses and created a three-dimensional rigid-body dynamic model of the arms and club. Next, we obtained torque data during the swing using inverse dynamics calculations, applied an STFT, and investigated the frequency component variations in time. Finally, we examined the variation in the spectrogram values when changing the shaft mass and searched for common patterns among participants. Results: The results confirmed that an increment of the shaft mass causes the maximum value of the spectrogram to increase for some participants and decrease for others. Moreover, we compared the trend of change of the average of the spectrogram in the low- and high-frequency regions with that of the shaft tip velocity, identifying the torque component that most contributes to the latter. Conclusion: Based on the results, we envision the possibility to suggest golfers a suitable shaft mass and movements that increase the shaft tip velocity. [ABSTRACT FROM AUTHOR]

This research study aimed to investigate the extraction of Insoluble Dietary Fiber (IDF) from under-utilized Kadam fruit (Neolamarkia cadamba) using an alkali-extraction method assisted with ultrasound and microwave treatments. The extracted samples were characterized using Fourier Transform Infrared, X-ray Diffraction and Scanning Electron Microscopy techniques. The highest yield of IDF was found in the microwave-assisted treated samples (4.36%), followed by ultrasound-assisted treated samples and untreated samples (3.83%, and 3.52% respectively). The Fourier Transform Infrared peaks confirmed that the extracted samples were IDF. X-ray Diffraction analysis suggested that the extracted samples were amorphous. The functional properties such as water holding capacity (WHC) (10.66 g/g), oil holding capacity (OHC) (1.30 g/g), swelling power (11.72%), solubility index (1.94%) and emulsion activity (31.14%) were found to be highest in the ultrasound-assisted treated samples, followed by microwave-assisted treated samples and untreated samples. Based on our findings, extracted IDF samples obtained from the Kadam fruit hold great potential to be used as a functional food ingredient. [ABSTRACT FROM AUTHOR]

Indonesia released a new regional geoid model in 2020—the Indonesian Geoid 2020 (INAGEOID2020). It covers the Indonesian region with a spatial resolution of 0.01 × 0.01 degree with the unit in meters. The model was generated through a series of data and computations. Three components of gravity data, i.e., the observed free-air anomaly, the long-wave from the global geoid model, and the short-wave from the terrain model, were employed. The computation was performed using the Remove-Compute-Restore technique with the Fast Fourier Transformation approach. The output was then fitted to the geoid at tide stations by adding a fitting plane to the geoid model. The fitting plane was constructed based on the difference between the geoid model and each tide gauge benchmark. The final geoid model was evaluated by comparing the model with the reference data. Based on quality metrics, the accuracy of INAGEOID2020 varied between 6 cm to 29 cm. Any interested user can use this gridded geoid model to convert geodetic to orthometric heights and vice versa. [ABSTRACT FROM AUTHOR]

This paper explores the Fourier decomposition method to approximate the decomposition of electrocardiogram (ECG) signals into their component waveforms, such as the QRS-complex and T-wave. We compute expansion coefficients using the ℓ 1 Fourier transform and the traditional ℓ 2 Fourier transform. Numerical examples are presented, and the analysis focuses on ECG signals as a real-world application, comparing the performance of the ℓ 1 and ℓ 2 Fourier transforms. Our results demonstrate that the ℓ 1 Fourier transform significantly enhances the separation of ECG signal components, such as the QRS-complex and T-wave. This improvement is attributed to a notable reduction in the Gibbs phenomenon introduced by the Fourier-series expansion when using the ℓ 1 Fourier transform, as opposed to the traditional ℓ 2 Fourier transform. [ABSTRACT FROM AUTHOR]

In this study, Polylactic acid (PLA)-polyvinylidene difluoride (PVDF) nanofiber-based smart composite structures were investigated for smart grippers and self-folding applications. In the first stage, the electrospinning process is used for PVDF nanofibers fabrication. In the second stage, fused filament fabrication-based 3D printing was used for manufacturing PLA composites with sandwiched PVDF nanofiber interleaves. In the next stage, mechanical, thermal, electrical, and shape memory (for self-folding abilities) performances were investigated. The optimized process parameters observed for self-folding PLA-PVDF nanofiber-based interleaves composite structures are the combination of 1 no. of PVDF nanofibers layer, 0.15 mm thickness of nanofibers layer, and zigzag infill pattern. The results of the study were supported by a scanning electron microscope, x-ray diffraction, and Fourier transform infrared analysis. Most importantly, the smart structure manufactured using a zigzag pattern showed better self-folding performance as compared to the structure manufactured using a grid pattern under the thermal stimulus. The investigation of the study suggested that PLA-PVDF nanofiber-based interleaves composite structures are potential candidates for self-folding, smart gripper, and smart actuator applications. [ABSTRACT FROM AUTHOR]

In an effort to estimate the number of true nulls in large scale multiplicity problems (the normal means problem), we generalize the current Fourier transform based oracle estimator with a Laplace transform based estimator. Our interest in this problem stems from the application of r-power which requires knowledge of the number of nulls (Dasgupta et al. in Sankhya B 78(1):96–118, 2016). We analytically show that our method is consistent and theoretically has lower mean squared error than the existing competitor (Jin in J R Stat Soc Ser B (Stat Methodol) 70(3):461–493, 2008). We follow up by a numerical example and a simulation study that ratifies our theoretical results. [ABSTRACT FROM AUTHOR]

We investigate the question: for which functions f (x 1 , ... , x n) , g (x 1 , ... , x n) the asymptotic expansion of the integral ∫ g (x 1 , ... , x n) e f (x 1 , ... , x n) + x 1 y 1 + ⋯ + x n y n ħ d x 1 ... d x n consists only of the first term. We reveal a hidden projective invariance of the problem which establishes its relation with geometry of projective hypersurfaces of the form { (1 : x 1 : ... : x n : f) } . We also construct various examples, in particular we prove that Kummer surface in P 3 gives a solution to our problem. [ABSTRACT FROM AUTHOR]

This paper presents simple numerical solutions for electromagnetic plane waves in spatially homogenous time varying medium. The solution is based on converting the resulting second order differential equation into two combined ordinary differential equations which are solved numerically by using the built-in ode113 function in Matlab. By using this method, the time domain responses of the electric and magnetic fields at fixed point in space are obtained. The proposed method is applied on two cases: linearly time varying medium and sinusoidally time varying medium. The corresponding frequency domain response is obtained by using inverse Fourier transformation of the obtained time domain response. The proposed method is compared with FDTD solution. It is found that the proposed method has the same accuracy of FDTD with much less computational time. [ABSTRACT FROM AUTHOR]

This paper proposes an Interpolated Discrete-Time Fourier Transform (LIpDTFT) estimator for complex-valued noisy sinewave frequency based on the Linearization of the DTFT module behavior around the spectrum peak. It belongs to a class of LIpDTFT estimators that compensate the poor Discrete Fourier Transform (DFT) frequency resolution by interpolating two DTFT samples located very close to an initial frequency estimate. As compared with other DTFT-based frequency estimators recently proposed in the literature, the proposed LIpDTFT estimator ensures a smaller interpolation error and a lower processing effort. Moreover, if the rectangular window is adopted, it almost attains the unbiased Cramér-Rao Lower Bound (CRLB) even if a very small number of samples is analyzed. The accuracies ensured in different operating conditions by the proposed frequency estimator and other state-of-the-art DTFT-based algorithms are compared to each other through computer simulations. [ABSTRACT FROM AUTHOR]

This paper investigates the nuanced characteristics of the spectral envelope attributes due to vocal-tract resonance structure and fine-level excitation source features within short-term Fourier transform (STFT) magnitude spectra for the assessment of dysarthria. The single-channel convolutional neural network (CNN) employing time-frequency representations such as STFT spectrogram (STFT-SPEC) and Mel-spectrogram (MEL-SPEC) does not ensure capture of the source and system information simultaneously due to the filtering operation using a fixed-size filter. Building upon this observation, this study first explores the significance of convolution filter size in the context of the CNN-based automated dysarthric assessment system. An approach is then introduced to effectively capture resonance structure and fine-level features through a multi-channel CNN. In the proposed approach, the STFT-SPEC is decomposed using a one-level discrete wavelet transform (DWT) to separate the slow-varying spectral structure and fine-level features. The resulting decomposed coefficients in four directions are taken as the inputs to multi-channel CNN to capture the source and system features by employing different sizes of convolution filters. The experimental results conducted on the UA-speech corpus validate the efficacy of the proposed approach utilizing multi-channel CNN. The proposed approach demonstrates the notable enhancement in accuracy and F1 score (60.86% and 48.52%) compared to a single-channel CNN using STFT-SPEC (46.45% and 40.97%), MEL-SPEC (48.86% and 38.20%), and MEL-SPEC appended with delta and delta-delta coefficients (52.40% and 42.84%) for assessment of dysarthria in a speaker-independent and text-independent mode. [ABSTRACT FROM AUTHOR]

Time–frequency analysis methods represent an efficacious approach to process data derived from full-waveform acoustic logging. This research proposes a coupled time–frequency analysis method that synergistically incorporates ensemble empirical mode decomposition, fractional Fourier transform, Choi–Williams (CW) distribution and adaptive filtering. This coupled method facilitates the comprehensive analysis of full-waveform acoustic logging signals within rigid geological formations. Specifically, it is designed to explore the time–frequency characteristics of shear wave (S-wave) within the context of igneous reservoirs. The coupled time–frequency analysis method significantly ameliorates the time–frequency coupling phenomenon of full-waveform acoustic logging signal. This coupled method is applied across different wells to confirm its wide-ranging applicability and study the time–frequency characteristics response of S-wave through the information of the peak time of the S-wave, the main frequency and the amplitude of the CW distribution. [ABSTRACT FROM AUTHOR]

We utilize a Fourier transformation-based representation of Maxwell's equations to develop physics-constrained neural networks for electrodynamics without gauge ambiguity, which we label the Fourier–Helmholtz–Maxwell neural operator method. In this approach, both of Gauss's laws and Faraday's law are built in as hard constraints, as well as the longitudinal component of Ampère–Maxwell in Fourier space, assuming the continuity equation. An encoder–decoder network acts as a solution operator for the transverse components of the Fourier transformed vector potential, A ^ ⊥ (k , t) , whose two degrees of freedom are used to predict the electromagnetic fields. This method was tested on two electron beam simulations. Among the models investigated, it was found that a U-Net architecture exhibited the best performance as it trained quicker, was more accurate and generalized better than the other architectures examined. We demonstrate that our approach is useful for solving Maxwell's equations for the electromagnetic fields generated by intense relativistic charged particle beams and that it generalizes well to unseen test data, while being orders of magnitude quicker than conventional simulations. We show that the model can be re-trained to make highly accurate predictions in as few as 20 epochs on a previously unseen data set. [ABSTRACT FROM AUTHOR]

Of the early Eocene amber deposits known across the world, Belgian amber has been mostly absent from the relevant literature. We reinvestigated amber held in the palaeobotanical collection of the Royal Belgian Institute of Natural Sciences, Brussels, which derived from three localities in Belgium that originated from two geographical areas (Leval-Trahegnies and Orp-le-Grand). Using Fourier transform infrared (FTIR) spectroscopy we show the close chemical relationship of Belgian amber to the early Eocene Oise amber from the Paris Basin, and highlight the potential effect of weathering on the amber chemistry. The amber derives from a very similar botanical source as the Oise amber (Combretaceae or Leguminosae-Caesalpinioideae), but from different coeval basins. The two Leval-Trahegnies localities provided amber that exhibit different stages of weathering (heavily fissured and crazed, darkened) and lacking any inclusions. The Orp-le-Grand locality provided the least weathered amber, with one amber piece containing two inclusions: a mite and a new genus and species of hemipteran (Cativolcus uebruum gen. et sp. nov.), and a second one that preserved the impression of insect wings pressed into the surface. [ABSTRACT FROM AUTHOR]

Medical images contain sensitive information and are prone to various attacks during network transmission. Therefore, it is essential to develop a robust algorithm to ensure the safety of transmitting medical images. In this paper, we propose an efficient and secure color medical image encryption system utilizing the FRFT-DRPE optical transformation and 2D-SICM hyperchaos system. The encryption process in our system considers the specific characteristics of each channel in the HSI color model. First, the image is converted from RGB space to HSI space. Subsequently, different encryption methods are applied to the hue and saturation components, including S-box replacement, scrambling, and diffusion operations. For the intensity component, scrambling and FRFT-DRPE optical encryption operations are performed. Additionally, the order of 2D-FRFT serves as an additional key to enhance the security of the encryption system. Finally, the three channels are merged to complete the overall encryption process. Simulations and performance analysis have confirmed the high-security level of our algorithm. It effectively protects the privacy of medical images during transmission. [ABSTRACT FROM AUTHOR]

Laser-based light detection and ranging (LIDAR) offers a powerful tool to real-timely map spatial information with exceptional accuracy and owns various applications ranging from industrial manufacturing, and remote sensing, to airborne and in-vehicle missions. Over the past two decades, the rapid advancements of optical frequency combs have ushered in a new era for LIDAR, promoting measurement precision to quantum noise limited level. For comb LIDAR systems, to further improve the comprehensive performances and reconcile inherent conflicts between speed, accuracy, and ambiguity range, innovative demodulation strategies become crucial. Here we report a dispersive Fourier transform (DFT) based LIDAR method utilizing phase-locked Vernier dual soliton laser combs. We demonstrate that after in-line pulse stretching, the delay of the flying pulses can be identified via the DFT-based spectral interferometry instead of temporal interferometry or pulse reconstruction. This enables absolute distance measurements with precision starting from 262 nm in single shot, to 2.8 nm after averaging 1.5 ms, in a non-ambiguity range over 1.7 km. Furthermore, our DFT-based LIDAR method distinctly demonstrates an ability to completely eliminate dead zones. Such an integration of frequency-resolved ultrafast analysis and dual-comb ranging technology may pave a way for the design of future LIDAR systems. Here the authors develop a dispersive Fourier transform (DFT) based LIDAR method utilizing phase-locked Vernier dual soliton laser combs and demonstrate improved precision in the measurements. [ABSTRACT FROM AUTHOR]

In this work, crystalline copper-zinc ferrite nanoparticles were synthesized by a simple co-precipitation method. Morphological characterization of produced samples was done using a scanning electron microscope (SEM). A transmission electron microscope (TEM) was utilised for further identification and confirmation of the particle morphology and size. Moreover, Fourier transformation infrared (FTIR) spectroscopy and X-ray diffraction (XRD) was employed to examine crystalline structure, chemical structure, and surface area respectively. Optical properties were examined by UV–Vis spectroscopy. The results indicate that the Zn0.5Cu0.5Fe2O4 nanoparticles' crystallite size was 28.5 nm. The experiments focused on the impact of various factors, such as pH levels, initial MB concentration, and nanocatalyst dosage, on the observed photocatalytic efficiency. The photocatalytic performance of Zn0.5Cu0.5Fe2O4 nanoparticles under UV light was evaluated by decolorization of Methylene Blue (MB) azo dye. Photocatalysis degradation of 10 ppm of MB adding 15 mg of Zn0.5Cu0.5Fe2O4 nanoparticles was 94% after 135 min at room temperature and pH value of 9. Further interpretation was carried out and a proposed mechanism for the MB photodegradation by Zn0.5Cu0.5Fe2O4 nanoparticles was suggested. [ABSTRACT FROM AUTHOR]

An adaptive algorithm for spectral proper orthogonal decomposition (SPOD) of mixed broadband-tonal turbulent flows is developed. Sharp peak resolution at tonal frequencies is achieved by locally minimizing bias of the spectrum. Smooth spectrum estimates of broadband regions are achieved by locally reducing variance of the spectrum. The method utilizes multitaper estimation with sine tapers. An iterative criterion based on modal convergence is introduced to enable the SPOD to adapt to spectral features. For tonal flows, the adaptivity is controlled by a single user input; for broadband flows, a constant number of sine tapers is recommended without adaptivity. The discrete version of Parseval's theorem for SPOD is stated. Proper normalization of the tapers ensures that Parseval's theorem is satisfied in expectation. Drastic savings in computational complexity and memory usage are facilitated by two aspects: (i) sine tapers, which permit post hoc windowing of a single Fourier transform; and (ii) time-domain lossless compression using a QR or eigenvalue decomposition. Sine-taper SPOD is demonstrated on time-resolved particle image velocimetry (TR-PIV) data from an open cavity flow (Zhang et al. in Exp Fluids 61(226):1–12, https://doi.org/10.1007/s00348-020-03057-8, 2020) and high-fidelity large-eddy simulation (LES) data from a round jet (Brès et al. in J. Fluid Mech. 851:83–124, https://doi.org/10.1017/jfm.2018.476, 2018), with and without adaptivity. For the tonal cavity flow, the adaptive algorithm outperforms Slepian-based multitaper SPOD in terms of variance and local bias of the spectrum, mode convergence, and memory usage. The tonal frequencies associated with the Rossiter instability are accurately identified. For both the tonal cavity and the broadband jet flows, results comparable to or better than those from standard SPOD based on Welch's overlapped segment averaging are obtained with up to 75% fewer snapshots, including similar convergence of the Rossiter modes and Kelvin-Helmholtz wavepacket structures for the cavity and jet examples, respectively. Drawing from these examples, we establish best practices. [ABSTRACT FROM AUTHOR]

This paper develops a frictional moving contact model for a functionally graded (FG) orthotropic layer pressed by a rigid cylindrical punch. The FG orthotropic layer is fully bonded to the isotropic half-plane. The punch moves to the left on the layer at a constant subsonic velocity and a shear stress arises in the contact zone according to the Coulomb friction law. General expressions of displacements and stresses are derived with the help of the Fourier transform and Galilean transformation. Using boundary conditions, the moving contact problem is reduced to a Cauchy-type singular integral equation, the unknowns of which are contact stress and contact width. Gauss–Jacobi integration formula is used to solve the obtained singular integral equation. The effect of some parameters and material properties on the contact width, contact stress and in-plane stress are given in graphical forms and detailed numerical interpretations are presented. [ABSTRACT FROM AUTHOR]

In this article, the nonclassical transient heat propagation process in a cracked strip is investigated by Guyer–Krumhansl (G–K) model, which incorporates both the time lagging behavior and the spatially nonlocal effect. The impulsive thermal loading as well as cyclic loading exerted on the top bounding surface are examined to explore the non-Fourier thermal characteristics. By means of the Laplace transform and Fourier transform, the governing partial differential equations subjected to mixed boundary conditions are converted to a group of singular integral equations. With the aid of numerical Laplace inversion, the transient temperatures are calculated to make comparisons of thermal responses determined by Fourier's law, Cattaneo–Vernotte (C–V) equation, and G–K model. The numerical results display the specific thermal behaviors of G–K model in the cracked medium and demonstrate the G–K model's capabilities in eliminating the unrealistic phenomena accompanied by C–V equation. Our research would contribute to achieving a better understanding of the transient heat conduction in small-sized systems or composites at the macroscopic scale. [ABSTRACT FROM AUTHOR]

The antiplane deformation of a two layered model consisting of a homogeneous, elastically isotropic (HEI) stratum of finite thickness lying on a HEI substratum occurring from a buried inclined strike-slip fault (ISF) situated in the stratum has been studied. The stratum is in welded contact with the substratum having different rigidity. The integral expressions for the deformation field occurring from a long strike-slip line dislocation for the antiplane strain case have been obtained using Fourier transform approach. The integrals have been solved analytically by expanding the denominator into a finite sum of exponential terms (FSET) using least square method. Further, the deformation is obtained for a long buried ISF of finite width via integrating over the width of line dislocation. The variation of the displacement has been computed graphically with respect to the epicentral distance as well as with depth. [ABSTRACT FROM AUTHOR]

In the industrial application of bacterial cellulose (BC), the yield becomes a crucial factor because it drives the selling price of BC. A Box–Behnken experimental design with three components and three levels was employed to create seventeen samples. A response surface method was then used to optimize the BC yield from the most relevant parameters, including incubation temperature, medium shaking intensity, and nitrogen supply pH. Fourier transform infrared (FTIR) analysis proved that BC was pure. By analyzing BC morphology using scanning electron microscopy (SEM), rod-like microfibrils with an average diameter of 6.5 were revealed. X-ray diffraction (XRD) tested the crystalline size and crystallinity and found 4.7 nm and 69%, respectively. Thermal transition and stability were assessed using a differential scanning calorimeter (DSC) and a thermogravimetric analyzer (TGA). For the manufacture of BC composite hydrogel, a chemical test method was used to determine the solubility of BC. This study aimed to identify the ideal circumstances for using leftover sweet lime pulp for biomedical applications to produce reasonably priced and effective BC. At 28.87 °C, 125.91 rpm shaking frequency, and 5.65 pH, a sweet lime pulp waste medium produced the highest yield of BC, three times greater than the yield in a Hestrin–Schramm medium under static circumstances. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the novel Chebyshev Polynomials Least-Squares Fourier Transformation (C-LSQ-FT) and its robust variant with the Iteratively Reweighted Least-Squares technique (C-IRLS-FT). These innovative techniques for Fourier transformation are predicated on the concept of inversion, and the C-LSQ-FT method establishes an overdetermined inverse problem within the realm of Fourier transformation. However, given the LSQ approach's vulnerability to data outliers, we note the potential for considerable errors and potentially unrepresentative model estimations. To circumvent these shortcomings, we incorporate Steiner's Most Frequent Value method into our framework, thereby providing a more reliable alternative. The fusion of the Iteratively Reweighted Least-Squares (IRLS) algorithm with Cauchy-Steiner weights enhances the robustness of our Fourier transformation process, culminating in the C-IRLS-FT method. We use Chebyshev polynomials as the basis functions in both methods, leading to the approximation of continuous Fourier spectra through a finite series of Chebyshev polynomials and their corresponding coefficients. The coefficients were obtained by solving an overdetermined non-linear inverse problem. We validated the performance of both the traditional Discrete Fourier Transform (DFT) and the newly developed C-IRLS-FT through numerical tests on synthetic datasets. The results distinctly exhibited the reduced sensitivity of the C-IRLS-FT method to outliers and dispersed noise, in comparison with the traditional DFT. We leveraged the newly proposed (C-IRLS-FT) technique in the application of low-pass filtering in the context of gravity data. The results corroborate the technique's robustness and adaptability, making it a promising method for future applications in geophysical data processing. Highlights: Inversion-based Fourier Transformation using Chebyshev Polynomials in discretization of the spectrum. Robustification by means of Cauchy-Steiner weights. Reduced outlier sensitivity of the new method compared to the traditional DFT. [ABSTRACT FROM AUTHOR]

Glass-nanocomposites (GNCs) samples of composition [(100−x) Li2B4O7–xPbTiO3] with x = 5, 10, 15 and 20 mol% were prepared by melt quenching method. The two phases of the GNCs samples, a glassy phase and PbTiO3 nanoparticles/clusters phase, can be seen in the energy dispersive X-ray spectra and scanning electron microscopic micrographs. Fourier transformation infrared spectra of the GNCs samples exhibited bands due to triangular with NBO's and tetrahedral borate groups. Additionally, the Ti4+ ions exist in both TiO4 and TiO6 structural units while the Ti3+ ions exist in TiO6 structural units. The electron spin resonance (ESR) spectra of the GNCs samples exhibit two ESR signals, broad and narrow, corresponding to the Ti3+ (3d1) ions in both tetragonal deformed octahedral and in the other structural configuration, respectively. The optical transmission spectra of the GNCs samples exhibited three transmission bands, 3Γ5 → 2Γ3, 2B2g → 2B1g and 2B2g → 2A1g transitions, in the visible region. The variation in optical band gap (Eopt) with increasing PbTiO3 content were due to the conversion between BO3 with NBOs and BO4 units as well as the reduction of Ti4+ to Ti3+ ions in the GNCs matrix. These results demonstrate that the present GNCs may be used for practical applications such as optical devices. [ABSTRACT FROM AUTHOR]

We investigate the leading twist generalized transverse momentum dependent parton distributions (GTMDs) of the unpolarized and longitudinally polarized gluons in the nucleon. We adopt a light-front gluon-triquark model for the nucleon motivated by soft-wall AdS/QCD. The gluon GTMDs are defined through the off-forward gluon-gluon generalized correlator and are expressed as the overlap of light-cone wave functions. The GTMDs can be employed to provide the generalized parton distributions (GPDs) by integrating out the transverse momentum. The Fourier transform of the GPDs encodes the parton distributions in the transverse position space, namely, the impact parameter dependent parton distributions (IPDs). We also calculate the three gluon IPDs corresponding to the GPDs H g , E g and H ~ g , and present their dependence on x and b ⊥ , respectively. [ABSTRACT FROM AUTHOR]

We introduce the continuous and discrete versions of multi-dimensional linear canonical wave packet transform with the non-separable kernel. At first, we establish a relationship between the non-separable linear canonical wave packet transform (NSLCWPT) and n-dimensional windowed Fourier transform (WFT) and then establish the fundamental results like reconstruction formula, orthogonality relation and some bounds for the NSLCWPT. Some examples were also provided for the enhancement of our proposed transform. We apply the discrete version of the NSLCWPT in the context of the almost periodic functions. At last, a simple conclusion is given, which provides the idea for future work. [ABSTRACT FROM AUTHOR]

In this study, polyvinyl alcohol (PVA)-based nanofibers were synthesized through electrospinning and infused gibberellic acid (GA3) to form microcapsules and evaluated for efficacy on seed quality enhancement. The polymer, polyvinyl alcohol (PVA at 15%), was used to synthesize nanofibers (281 nm) and, upon infusion of the analyte (GA3 at 100 ppm), resulted in the formation of microcapsules, where characterization of morphology and analyte integration was done through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. GA3-infused microcapsules were coated on fresh and accelerated-aged maize seeds, and germination potential tests were performed as per the International Seed Testing Association (ISTA) seedling group number (A 1-2–3-2). The evaluation of seed enhancement of aged seeds showed the effect of precision coating (GA3-infused microcapsules) in attaining superior seedling performance even after triggering the seed deterioration process through accelerated aging. The results revealed that the seed quality parameters like higher germination (80%), seedling length (23 cm), seedling dry weight (0.53 g), and vigor indices had been significantly enhanced due to GA3-infused microcapsules coating in aged maize seeds. [ABSTRACT FROM AUTHOR]

This study was conducted to optimize the reaction conditions based on the solubility percentage of carboxymethyl NMG by monochloroacetic acid (MCA) in the presence of sodium hydroxide (alkaline environment). The effect of various reaction parameters (pH, MCA concentration, and temperature) on the solubility of NFG was evaluated. The highest solubility (85.49% by weight) was obtained at the NaOH concentration of 0.048 mol and MCA (as an etherifying agent) concentration of 0.016 mol at 75 °C. The novel nanofibers (NFs) were developed using modified frankincense gum (MFG)/Zein-containing peppermint essential oil (PEO) by applying electrospinning at different MFG/Zein ratios. The results of the Fourier transform infrared (FT-IR) analysis demonstrated compatibility between essential oil and MFG/Zein. Furthermore, the prepared scaffold (i.e., Zein/MFG/PEO) showed antibacterial properties against Staphylococcus aureus and Escherichia coli. According to the current research, the obtained NFs can be conveniently used as a substrate for encapsulating PEO as a hydrophobic component. Also, modified gum was identified as an excellent source of natural gum with high functional and physical properties. Therefore, it can be used in the formulation of food products, packaging of activity foods, and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Given a function f ∈ L 2 (R) , we consider means and variances associated to f and its Fourier transform f ^ , and explore their relations with the Wigner transform W(f), obtaining, as particular cases, a simple new proof of Shapiro's mean-dispersion principle, as well as a stronger result due to Jaming and Powell. Uncertainty principles for orthonormal sequences in L 2 (R) involving linear partial differential operators with polynomial coefficients and the Wigner distribution, or different Cohen class representations, are obtained, and an extension to the case of Riesz bases is studied. [ABSTRACT FROM AUTHOR]

Continuous excessive irrigation and industrial activities increase the salinity in the environment which poses a threat to the current technology used in the Methyl Red degradation process. Hence it is quite essential to use a microbe which can be used in very high saline conditions. The present study focuses on the kinetic and isotherm studies on the novel bacterium Lactiplantibacillus plantarum SS-AU1 for Methyl Red bio-degradation under high salinity.he degradation was assessed based on the UV-Spectrophotometer studies. Kinetics and Isotherm studies were also performed to find the mechanism involved. The findings were also justified by Scanning Electron Microscope images and Fourier Transformed Infrared spectra.The strain can degrade up to 400 mg L−1 dye concentration. Kinetic studies revealed chemisorption involvement in the process where maximum adsorption was observed at 2500 mg g−1 and the formation of multilayer on the cell surface was confirmed. It followed the pseudo-second-order at low dye concentration while the pseudo-first-order at high dye concentration. The high degradation efficiency, having Km = 0.092 mMol−1 L and Vm = 0.761 mmol min−1, can be attributed to intra-particle diffusion predicted by the Weber-Morris and Elovich-Model. The weak bonding (E = 28 J/mol) is a key-finding behind the efficient degradation. Infrared spectroscopy study revealed the breakdown of the azo-bond. In addition, a Biodegradation mechanism has been suggested. [ABSTRACT FROM AUTHOR]

Universal style transfer (UST) infuses styles from arbitrary reference images into content images. Existing methods, while enjoying many practical successes, are unable of explaining experimental observations, including different performances of UST algorithms in preserving the spatial structure of content images. In addition, methods are limited to cumbersome global controls on stylization, so that they require additional spatial masks for desired stylization. In this work, we first provide a systematic Fourier analysis on a general framework for UST. We present an equivalent form of the framework in the frequency domain. The form implies that existing algorithms treat all frequency components and pixels of feature maps equally, except for the zero-frequency component. We connect Fourier amplitude and phase with a widely used style loss and a well-known content reconstruction loss in style transfer, respectively. Based on such equivalence and connections, we can thus interpret different structure preservation behaviors between algorithms with Fourier phase. Given the interpretations, we propose two plug-and-play manipulations upon style transfer methods for better structure preservation and desired stylization. Both qualitative and quantitative experiments demonstrate the improved performance of our manipulations upon mainstreaming methods without any additional training. Specifically, the metrics are improved by 6% in average on the content images from MS-COCO dataset and the style images from WikiArt dataset. We also conduct experiments to demonstrate (1) the abovementioned equivalence, (2) the interpretability based on Fourier amplitude and phase and (3) the controllability associated with frequency components. [ABSTRACT FROM AUTHOR]

Star-like structural compounds were synthesized from different moles % of either dodecyl acrylate or triethylenetetramine using a one-pot commercial synthesis technique. The polymers that were created had various terminations. Fourier Transform Infrared (FTIR) spectroscopy and 1HNMR were used to verify the produced polymers' chemical composition with different terminations. Furthermore, by analysis of Dynamic Light Scattering (DLS), the size and distribution of the synthesised branched polymers were evaluated. Using a Gel-permeation chromatograph, the modified hyperbranched polymer's molecular weight, synthesized with various end points, were assessed. The unorganized structured prepared compounds with various molar feed ratios dodecyl acrylate: triethylenetetramine (DDA: TETA) was designed as A, B, C, D and E. Moreover, the synthesized additives function as viscosity index improvers (VII). As the concentration of polymeric additives increases, it leads to higher VI values. Similarly, with the increase in percentage of triethylenetetramine in the prepared hyperbranched polymers, the VI also increases. Notably, the most effective VI achieved is (E) = 212. It is noteworthy that all the synthesized hyperbranched polymers exhibited Newtonian behavior in the rheological study. [ABSTRACT FROM AUTHOR]

The biology underlying proton minibeam radiation therapy (pMBRT) is not fully understood. Here we aim to elucidate the biological effects of pMBRT using Fourier Transform Infrared Microspectroscopy (FTIRM). In vitro (CTX-TNA2 astrocytes and F98 glioma rat cell lines) and in vivo (healthy and F98-bearing Fischer rats) irradiations were conducted, with conventional proton radiotherapy and pMBRT. FTIRM measurements were performed at ALBA Synchrotron, and multivariate data analysis methods were employed to assess spectral differences between irradiation configurations and doses. For astrocytes, the spectral regions related to proteins and nucleic acids were highly affected by conventional irradiations and the high-dose regions of pMBRT, suggesting important modifications on these biomolecules. For glioma, pMBRT had a great effect on the nucleic acids and carbohydrates. In animals, conventional radiotherapy had a remarkable impact on the proteins and nucleic acids of healthy rats; analysis of tumour regions in glioma-bearing rats suggested major nucleic acid modifications due to pMBRT. [ABSTRACT FROM AUTHOR]

Spectral characterization of noise environments that lead to the decoherence of qubits is critical to developing robust quantum technologies. While dynamical decoupling offers one of the most successful approaches to characterize noise spectra, it necessitates applying large sequences of π pulses that increase the complexity and cost of the method. Here, we introduce a noise spectroscopy method that utilizes only the Fourier transform of free induction decay or spin echo measurements, thus removing the need for the application many π pulses. We show that our method faithfully recovers the correct noise spectra for a variety of different environments (including 1/f-type noise) and outperforms previous dynamical decoupling schemes while significantly reducing their experimental overhead. We also discuss the experimental feasibility of our proposal and demonstrate its robustness in the presence of statistical measurement error. Our method is applicable to a wide range of quantum platforms and provides a simpler path toward a more accurate spectral characterization of quantum devices, thus offering possibilities for tailored decoherence mitigation. [ABSTRACT FROM AUTHOR]