Sample Length Research Articles

Determination of Optimal Sample Length for Passive Intermodulation Measurements in Microstrip Lines with Non-Contact Connections

Determination of Optimal Sample Length for Passive Intermodulation Measurements in Microstrip Lines with Non-Contact Connections

High-resolution 2D-DoA sequential algorithm of azimuth and elevation estimation in automotive distributed system of coherent MIMO radars

Objectives. One of the main tasks of radiolocation involves the problem of increasing spatial resolution of the targets in the case of limited aperture of the radar antenna array and short length of time samples (snapshots). Algorithms must be developed to provide high angular resolution and low computational complexity. In order to conform with the existing Advanced Driver Assistance Systems requirements, modern cars are equipped with more than one radar having a common signal processing scheme to improve performance during target detection, positioning, and recognition as compared to a single radar. The present study aims to develop a two-dimensional Direction-of-Arrival algorithm with low computation complexity as part of distributed coherent automotive radar system for cases involving short time samples (snapshots).Methods. A virtual antenna array formation algorithm is formulated according to the two-dimensional Capon method. A proposed modification of two-dimensional Capon algorithm is based on sequentially estimating the directions of arrival for the distributed radar system. The Monte Carlo method is used to compare the effectiveness of the considered algorithms.Results. The 2D-DoA sequential algorithm of azimuth and elevation estimation is proposed. The comparative analysis results for the developed algorithm and classical 2D Capon method based on numerical simulation using Monte Carlo method are presented. The proposed scheme of DoA estimation for coherent signal processing of distributed radars is shown to lead to an improvement of the main considered metrics representing the probability of correctly estimating the number of targets, mean square error, and square error compared to a single radar system. The proposed low-computational algorithm shows the gain in complexity compared to full 2D Capon algorithm.Conclusions. The proposed two-stage algorithm for estimating the directions of arrival of signals in azimuth and elevation planes can be applied to the distributed system of coherent radars with several receiving and transmitting antennas representing multiple input multiple output (MIMO) radars. The algorithm is based on sequentially estimating the directions of arrival, implying estimation in the azimuthal plane at the first stage and estimation in the vertical plane at the second stage. The performance of a coherent radar system with limited antenna array configuration of separate radar is close in characteristics to a high-performance 4D-radar with a large antenna array system.

Microstructure Characteristic and Mechanical Properties of Copper Influenced Grey Cast Iron

Grey cast iron (GCI) is characterized by brittleness, making it unsuitable for use in applications requiring high impact loading. Hence, efforts were made in this study to produce GCI with improved mechanical properties by addition of copper. Four samples were produced, the first sample was not alloyed (control), and the second, third and fourth were alloyed with 1.4wt.%Cu, 1.8wt.%Cu and 2.2wt.%Cu respectively. The samples were characterized using scanning electron microscope with EDS, and tested in tensile, hardness and impact. From the results, silicon contents of the alloyed samples are high relative to the control sample. The control and 2.2wt.%Cu alloyed samples are hypereutectic with carbon equivalent values (CEVs) of 4.391% and 4.200% respectively, while the 1.4wt.%Cu and 1.8wt.%Cu alloyed samples are hypoeutectic with CEVs of 3.940% and 3.600% respectively. The control sample is characterized by long graphite flakes, which are uniformly distributed within ferritic - pearlitic matrix. Graphite flakes of the 1.4 wt.% Cu and 1.8 wt.% Cu alloyed samples are uniformly distributed within pearlitic - ferritic matrix, while graphite flakes of the 2.2wt.%Cu alloyed sample are uniformly distributed within ferritic-pearlitic. Average graphite flake length of the control sample is high as compared to the copper alloyed samples, while graphite flake count of the control sample is low relative to the copper alloyed samples. Tensile strength characteristics of the copper alloyed samples are superior to the control sample. Optimum tensile strength characteristics (165.9 Nm2) was obtained at 1.4wt.%Cu. Ductile characteristic of the of control the sample is superior to ductile characteristics of the copper alloyed samples. Optimum ductility characteristic (3.82%) was obtained at 2.2 wt. %Cu. Hardness characteristics of the copper alloyed samples are superior to hardness characteristic of the control sample. Optimum hardness characteristics (61 HRB) was obtained at 1.4wt.%Cu. Impact strength characteristic of the control sample is low relative to impact strength characteristics of the copper alloyed samples. Optimum impact strength characteristics (78.93 KJ/m2) was obtained at 2.2wt.%Cu.

Impact of breath sample collection method and length of storage of breath samples in Tedlar bags on the level of selected volatiles assessed using gas chromatography-ion mobility spectrometry (GC-IMS)

The analysis of volatile organic compounds (VOCs) in exhaled air has attracted the interest of the scientific community because it provides the possibility of monitoring physiological and metabolic processes and non-invasive diagnostics of various diseases. However, this method remains underused in clinical practice as well as in research because of the lack of standardized procedures for the collection, storage and transport of breath samples, which would guarantee good reproducibility and comparability of results. The method of sampling, as well as the storage time of the breath samples in the polymer bags used for sample storage and transport, affect the composition and concentration of VOCs present in the breath samples. The aim of our study was to compare breath samples obtained using two methods with fully disposable equipment: a Haldane sampling tube intended for direct breath collection and breath samples exhaled into a transparent Tedlar bag. The second task was to monitor the stability of selected compounds of real breath samples stored in a Tedlar bag for 6 h. Gas chromatography coupled with ion mobility spectrometry (GC-IMS) implemented in the BreathSpec® device was used to analyse exhaled breath. Our results showed a significant difference in the signal intensity of some volatiles when taking a breath sample with a Haldane tube and a Tedlar bag. Due to its endogenous origin, acetone levels were significantly higher when the Haldane tube sampler was used while elevated levels of 2-propanol and unidentified VOC (designated as VOC 3) in the Tedlar bag samples likely originated from contamination of the Tedlar bags. The VOC stability study revealed compound-specific signal intensity changes of the selected VOCs with storage time in the Tedlar bags, with some volatiles showing increasing signal intensity during storage in Tedlar bags. This limits the use of Tedlar bags only for very limited time and carefully selected purpose. Our results highlight the importance of careful design and implementation of experiments and clinical protocols to obtain relevant and reliable results.

Effects of Sampling Length and Overlap Ratio on EEG Mental Arithmetic Task Performance: A Comparative Study

Cognitive tasks have become quite popular in recent years. Understanding this sort of neurological research, its real-world applications, and how it may be improved in future studies are crucial. For this purpose, our study compares the classification accuracies for various segment lengths and overlap ratios for EEG recordings collected from 36 healthy volunteers during mental arithmetic tasks. EEG features are extracted from brain signals using the wavelet spectrum and the sample length and the overlap ratio of the sliding Windows are used as parameters. Feature selection was conducted using Correlation-Based and ReliefF feature selections. Subsequently, for classification results, Support Vector Machine, Random Forest, C4.5 Algorithm and k-Nearest Neighbor algorithms were employed, with the outcomes supported by the F1-score and Matthew's correlation coefficient. Therefore, the reliability of the obtained results has been ensured. In the comparisons obtained, the best average results for Accuracy, F1-score, and Matthew's correlation coefficient were found to be 0.990, 0.987, and 0.975 respectively, when applying the ReliefF feature selection method with the Support Vector Machine classifier.

An intelligent assessment method of criminal psychological attribution based on unbalance data

Criminal cases often exhibit imbalance and cannot be extended by data augmentation when classified into attribution types. To solve the problem of unbalance data in offenders’ attribution classification, this paper proposes a criminal psychological attribution assessment model by an improved Balanced TF-Distinguishing IDF method (B-TF-dIDF) and constructed a hybrid network with attention method to fuse numerical and text features for improving the accuracy. First, as a statistical method, B-TF-dIDF is presented to reduce the impact of class-imbalance for extraction of numerical features, in which a balanced element is added to reduce the effects of incorrect type keywords on classification, and a distinguishing element is added to discriminate the types of keywords. Then, an improved hybrid network model composed of Long Short-Term Memory (LSTM) and Convolutional Neural Network (CNN) is constructed to balance the influence of different lengths of text samples for extracting the semantic features of criminal texts. For evaluating different feature weights by their importance, Spatial Attention is used to improve CNN in the feature maps. Moreover, the self-attention is also performed to re-evaluate the mixed features. Finally, the softmax classifier provides a scientific basis for developing a hierarchical treatment mechanism further. Additionally, we build a criminal data set with labels from real cases for testing. The experiment proved that the proposed model is better than other related methods in various evaluation indicators, including the micro and macro scopes. Moreover, the F1 of minority samples has increased by 6%–8%, indicating that the proposed method can reduce the impact of class-imbalance.

Impact of iodinated oil in proton therapy on relative stopping power of liver post-cTACE

Objective. Conventional transarterial chemoembolization (cTACE) is a common treatment for hepatocellular carcinoma (HCC), often with unsatisfactory local controls. Combining cTACE with radiotherapy shows a promise for unresectable large HCC, with proton therapy preserving healthy liver tissue. However, the proton therapy benefits are subject to the accuracy of tissue relative stopping power (RSP) prediction. The RSP values are typically derived from computed tomography (CT) images using stoichiometric calibration. Lipiodol deposition significantly increases CT numbers in liver regions of post-cTACE. Hence, it is necessary to evaluate the accuracy of RSP in liver regions of post-cTACE. Approach. Liver, water, and iodinated oil samples were prepared. Some liver samples contained iodinated oil. The water equivalent path length (WEPL) of sample was measured through the pullbacks of spread-out Bragg peak (SOBP) depth-dose profiles scanned in a water tank with and without sample in the beam path. Measured RSP values were compared to estimated RSP values derived from the CT number based on the stoichiometric calibration method. Main results. The measured RSP of water was 0.991, confirming measurement system calibration. After removing the RSP contribution from container walls, the pure iodinated oil and liver samples had RSP values of 1.12 and 1.06, while the liver samples mixed with varying oil volumes (5 ml, 10 ml, 15 ml) showed RSP values of 1.05, 1.05 and 1.06. Using the stoichiometric calibration method, pure iodinated oil and liver samples had RSP values of 2.79 and 1.06. Liver samples mixed with iodinated oil (5 ml, 10 ml, 15 ml) had calculated RSP values of 1.21, 1.34, and 1.46. The RSP discrepancy reached 149.1% for pure iodinated oil. Significance. Iodinated oil notably raises CT numbers in liver tissue. However, there is almost no effect on its RSP value. Proton treatment of post-cTACE HCC patients can therefore be overshooting if no proper measures are taken against this specific effect.

Bayesian uncertainty quantification of modal parameters and RRF identification of transmission towers with limited measured vibration data

The resonant response factor (RRF) sensitive to modal parameters, including the damping ratio and frequency, is a critical parameter for wind-resistant design of extra high voltage (EHV) transmission towers, because it directly affects the calculation of the wind vibration coefficient. However, the research on operational modal analysis (OMA) of in-service EHV transmission towers is limited due to the high risk of field monitoring. Therefore, it is critical to determine the size of sufficient data samples or minimum monitoring duration for the OMA of a transmission tower. In this study, an investigation of uncertainty quantification in Bayesian OMA of EHV transmission towers with small data samples from the ambient dynamic test is carried out. The uncertainty of the resonant component factor for wind-resistance design is proposed and quantified, which could provide engineering designers with a reference for confidence levels. Firstly, a field test system is installed on a multipurpose EHV transmission tower with a closed-loop cat head and a pair of cross-arms, to gather the acceleration responses. Then, the OMA for the transmission tower is carried out by the fast Bayesian FFT (FBFFT) method to determine the modal parameters as well as the associated posterior uncertainty. The small sample analysis of OMA for the transmission tower is further performed to obtain sufficient data samples and minimum monitoring duration. Finally, the distribution of the RRF is presented with the different confidential levels. It is found that a sampling length of 600 s could fulfill the basic needs of accuracy in Bayesian OMA and the determination of RRF. The outcomes of this study may provide a reference for the wind-resistance design parameter selection of the similar type of transmission towers.

Laboratory Earthquake Ruptures Contained by Velocity Strengthening Fault Patches

AbstractMany natural faults are believed to consist of velocity weakening (VW) patches surrounded by velocity strengthening (VS) sections. Numerical studies routinely employ this framework to study earthquake sequences including repeating earthquakes. In this laboratory study, we made a VW asperity, of length L, from a bare Poly(methyl methacrylate) PMMA frictional interface and coated the surrounding interface with Teflon to make VS fault sections. Behavior of this isolated asperity was studied as a function of L (ranging from 100 to 400 mm) and the critical nucleation length, , which is inversely proportional to the applied normal stress (2–16 MPa). Consistent with recent numerical simulations, we observed aseismic slip for < 2, periodic slip for 2 < < 6, and non‐periodic slip for 10 < . Furthermore, we compared the experiments where L was contained by VS material to standard stick‐slip events where L was bounded by free surfaces (i.e., L = the total sample length). The free surface case produced ∼10 times larger slip during stick‐slip events compared to the contained fault ruptures, even with identical . This disparity highlights how standard, complete‐rupture stick‐slip events differ from contained events expected in nature, due to both the free surface conditions and the heterogeneous normal stress along the fault near the free ends, as confirmed by Digital Image Correlation analysis. This study not only introduces the Teflon coating experimental technique for containing laboratory earthquake ruptures, but also highlights the utility of as a predictive parameter for earthquake behavior.

Infeksi Ektoparasit dan Korelasinya dengan Panjang, Berat, dan Faktor Kondisi Benih Ikan Mas Merah Najawa (Cyprinus carpio Linneaus)

One of the problems in commona carp farming activities is ectoparasite infection which is thought to correlate with length, weight and condition of the fish. The aims of the research were to determine the species, prevalence, intensity and dominance of ectoparasites and to determine the correlation between the number of ectoparasites and the length, weight and condition factors of Najawa red carp (Cyprinus carpio Linneaus) fingerling at BPTPB Cangkringan. The research used laboratory observation method on randomly selected fish samples. Sampling was carried out for 3 weeks and a total of 27 individuals were examined. Ectoparasite observations were carried out on mucus samples from the body surface and gill sheets microscopically. The length and weight of each fish sample were measured and the results were used to calculate the condition factor. The correlation relationship was calculated between the number of ectoparasites and the length, weight and condition factors of the fish. The research results showed that five ectoparasites were found to infect fish samples with varying prevalence and intensity values, namely Trichodina sp., Dactylogyrus sp., Gyrodactylus sp., Glochidium sp. and Vorticella sp. Trichodina sp. has the highest prevalence, intensity and dominance compared to other parasites. The number of ectoparasites has a positive correlation with the length and weight of fish in the low category. In addition, a low negative correlation was found between the number of ectoparasites and fish condition factor. The results of this study indicate that ectoparasites are a factor that can influence the productivity of Najawa red carp cultivation.

Ternary Precursor Centrifuge Rolling Bearing Fault Diagnosis Based on Adaptive Sample Length Adjustment of 1DCNN-SeNet

To address the issues of uneven sample lengths in the centrifuge machine bearings of the ternary precursor, inaccurate fault feature extraction, and insensitivity of important feature channels in rolling bearings, a rolling bearing fault diagnosis method based on adaptive sample length adjustment of one-dimensional convolutional neural network (1DCNN) and squeeze-and-excitation network (SeNet) is proposed. Firstly, by controlling the cumulative variance contribution rate in the principal component analysis algorithm, adaptive adjustment of sample length is achieved, reducing data with uneven sample lengths to the same dimensionality for various classes. Then, the 1DCNN extracts local features from bearing signals through one-dimensional convolution-pooling operations, while the SeNet network introduces a channel attention mechanism which can adaptively adjust the importance between different channels. Finally, the 1DCNN-SeNet model is compared with four classic models through experimental analysis on the CWRU bearing dataset. The experimental results indicate that the proposed method exhibits high diagnostic accuracy in rolling bearings, demonstrating good adaptability and generalization capabilities.

What can we learn from long hydrological time-series? The case of rainfall data at Collegio Romano, Rome, Italy

In this work, we explore the statistical behavior of one of the longest rainfall time-series in Italy and in the world, covering the period 1782–2017. Some standard and innovative statistical tools are applied to test the variability and change of the process across all values (in average, but also in terms of extremes) and scales (from days to years). An oscillation pattern occurs across all the time scales, from years to decades, limited by the sample length. It implies that there are no particular periods of variability, apart from seasonality, and no statistically significant trends, such that the process can be fully characterized in terms of the Hurst coefficient. Despite its exceptional length, the dataset is still insufficient to adequately capture the complex behavior of rainfall over the time scales, especially with regards to extremes, and to separate anthropogenically induced change from natural variability based on the data alone. Our findings suggest that samples of limited length do not allow robust statistical predictions, raising concerns about statistical analyses based on a limited dataset, even a relatively large one.

Corrosion sample streamlining to enhance the performance of the rotating cage testing setup

Computations of the flow inside the rotating cage, a widely used testing methodology for flow-accelerated corrosion studies, are presented in this study. The main objectives here are to elucidate the flow behaviour inside the cage geometry that is recommended by the American Society for Testing and Materials (ASTM) and to investigate the effects of streamlining the shape of the cuboid sample recommended by ASTM. The streamlined sample profile considered here comprises a semi-circular leading edge, a triangular trailing edge and a flat mid-section with uniform thickness. It is found that the low value of the ratio of radius of rotation to sample length in the standard geometry makes it difficult to completely eliminate flow separation. Nonetheless, the flow is attached to the streamlined samples at locations of interest to corrosion measurements which inflicts more shear on the samples’ surfaces compared to the flow around the conventional blunt cuboid samples normally used. Moreover, we discuss the unsteadiness of the samples’ wakes and how the flow recirculation behaves differently, depending on both the sample shape and the flow Reynolds number.

Tensile Properties of Isotropic and Anisotropic Magnetorheological Elastomer With and Without Magnetic Field Application

In this study, two variations of magnetorheological elastomer (MRE) tensile specimens were fabricated, differing in their isotropic and anisotropic configurations. The isotropic MRE exhibited randomly dispersed carbonyl iron particle (CIP), whereas the anisotropic featured longitudinally aligned CIP particles along the gauge length of the tensile sample. The formation of the anisotropic MRE involved utilizing an electromagnetic curing chamber, which facilitated the alignment of CIP particles during the elastomer curing process. A mold was specifically designed to produce samples conforming to the dimensions outlined in ASTMD412-F. Subsequently, a Finite Element Method Magnetics (FEMM) analysis was conducted to examine the magnetic flux within the curing device for the anisotropic MRE. Uniaxial tensile tests were conducted on both MRE types, both in the absence and presence of a 30 mT magnetic field applied transversely to the direction of CIP alignment. Results indicated that without a magnetic field, the anisotropic sample exhibited a slightly higher tensile strength, lower elongation, and higher modulus at 100% strain. However, when a magnetic field was introduced, the isotropic sample demonstrated a more pronounced increase in tensile strength, showing an 18.4% improvement compared to the 5.6% increase observed in the anisotropic sample. Similar trends were observed in the reduction of elongation, with a 14% decrease for isotropic and a 7% decrease for anisotropic samples. Additionally, the data on modulus at a 100% strain revealed a 22.3% increase in stiffness for the isotropic sample, while the anisotropic sample showed a 10.6% increase.

Cognitive function and skeletal size and mineral density at age 6–7 years: Findings from the Southampton Women's Survey

IntroductionPoor cognitive function and osteoporosis commonly co-exist in later life. In women, this is often attributed to post-menopausal estrogen loss. However, a common early life origin for these conditions and the associations between cognitive function and bone mineral density (BMD) in childhood have not previously been explored. We examined these relationships at age 6–7 years in the Southampton Women's Survey (SWS) mother-offspring cohort. MethodsChild occipitofrontal circumference (OFC), a proxy for brain volume, intelligence quotient (IQ) [Wechsler Abbreviated Scale of Intelligence] and visual recognition and working memory [CANTAB® Delayed Matching to Sample (DMS) and Spatial Span Length (SSP), respectively] were assessed. Whole-body-less-head (WBLH) and lumbar spine dual-energy X-ray absorptiometry [Hologic Discovery] (DXA) were performed to measure bone area (BA), bone mineral content (BMC), BMD and bone mineral apparent density (BMAD). Linear regression was used to examine associations between age and sex standardized variables (β represent standard deviation (SD) difference per SD of cognitive function). ResultsDXA was performed in 1331 children (mean (SD) age 6.8 (0.33) years, 51.5 % male), with OFC, IQ, DMS and SSP assessed in 1250, 551, 490 and 460, respectively. OFC (β = 0.25 SD/SD, 95%CI 0.20,0.30), IQ (β = 0.11 SD/SD, 95%CI 0.02,0.19), and DMS (β = 0.11, SD/SD, 95%CI 0.01,0.20) were positively associated with WBLH BA, with similar associations for lumbar spine BA. OFC and DMS were also positively associated with WBLH BMC, but only OFC was associated with BMD (WBLH: β = 0.38 SD/SD, 95%CI 0.33,0.43; LS: β = 0.19 SD/SD, 95%CI 0.13,0.24). ConclusionChildhood brain volume was positively associated with measures of skeletal size and BMD, whereas IQ and memory were associated only with skeletal size. These findings suggest that common early life determinants for skeletal growth and BMD and cognitive function should be explored to identify potential early-life approaches to preventing osteoporosis and cognitive decline.

Mean Length of Utterance in Czech Toddlers: Validity Estimates and Comparison of Words, Morphemes, and Syllables.

We examined the properties of mean length of utterance (MLU) in Czech, a morphologically complex Slavic language. We compared the scores of MLU calculated in different units and based on different sample lengths and assessed its validity against another transcript and test-based measures. One hundred nine children were recorded during free-play at 2;6 and 3;11 (years;months). We compared MLU in syllables, morphemes, and words (MLUw) in transcripts of different lengths (50, 75, 100, and all available utterances). For evaluating the validity of MLU, we also calculated Index of Productive Syntax (IPSyn) and number of different words (NDW) and used results of receptive vocabulary and grammar comprehension tests. The different MLU measures based on different sample lengths correlated closely with MLU in transcripts of all utterances (all rs > .87). We found mostly strong correlations between MLU, IPSyn, and NDW at both time points and weak or moderate correlations between MLU and grammar and vocabulary. Regression models showed the significant unique effect of MLUw at 2;6 for MLUw (β = .29) and grammar (β = .33) at 3;11 and vocabulary (β = .27) at 3;7. MLUw based on all utterances was confirmed as a valid measure of early language skills in Czech, as it is stable in time and shows concurrent and predictive relations with other transcript-based and test-based measures. https://doi.org/10.23641/asha.25215203.

Effect of sample length on MLU in Mandarin-speaking hard-of-hearing children.

This study investigated the impact of language sample length on mean length of utterance (MLU) and aimed to determine the minimum number of utterances required for a reliable MLU. Conversations were collected from Mandarin-speaking, hard-of-hearing and typical-hearing children aged 16-81months. The MLUs were calculated using sample sizes ranging from 25 to 200 utterances. The results showed that for an MLU between 1.0 and 2.5, 25 and 50 utterances were sufficient for reliable MLU calculations for hard-of-hearing and typical-hearing children, respectively. For an MLU between 2.5 and 3.75, 125 utterances were required for both groups. For an MLU greater than 3.75, 150 and 125 utterances were required for hard-of-hearing and typical-hearing children, respectively. These findings suggest that a greater number of utterances are required for a reliable MLU as language complexity increases. Professionals working with hard-of-hearing children should consider collecting different numbers of utterances based on the children's language complexity levels.

The effect of Tween 80 on monochlorobenzene migration in bentonite

Several studies conducted at industrial sites have documented the infiltration of dense non-aqueous phase liquids (DNAPLs) into clay layers, a phenomenon potentially influenced by the coexistence of chemicals like surfactants in some common pollutants. Bentonite (Ben), monochlorobenzene (MCB), and Tween 80 (T80) were selected as reference components to investigate the influences of nonionic surfactants on DNAPLs migration in clays. Results showed that T80 promotes MCB dissolution and encourages MCB adsorption on Ben. This process reduces the hydrophilicity of Ben, resulting in water loss and shrinkage, which creates cracks and facilitates the migration of MCB within the clay. Tw80 notably enhances MCB solubility, as indicated by a molar solubilization ratio of 7.80. The MCB adsorption on Ben (QMCB) displays a linear increase with raising the T80 adsorption on Ben (QT80), especially when QT80 are below the thresholds, e.g., 408.4 mg/g at pH 3 and 339.3 mg/g at pH 7; however, QMCB is decreased with increasing adsorbed T80 further. The average fracture ratio, crack length, and crack width of cracked samples in the cracking experiments were 0.794%, 11.29 mm, and 0.209 mm, respectively. The findings here contribute to understanding the role of surfactants in VOC transport in contaminated sites.

Exploring the performance of automatic speaker recognition using twin speech and deep learning-based artificial neural networks.

This study assessed the influence of speaker similarity and sample length on the performance of an automatic speaker recognition (ASR) system utilizing the SpeechBrain toolkit. The dataset comprised recordings from 20 male identical twin speakers engaged in spontaneous dialogues and interviews. Performance evaluations involved comparing identical twins, all speakers in the dataset (including twin pairs), and all speakers excluding twin pairs. Speech samples, ranging from 5 to 30 s, underwent assessment based on equal error rates (EER) and Log cost-likelihood ratios (Cllr). Results highlight the substantial challenge posed by identical twins to the ASR system, leading to a decrease in overall speaker recognition accuracy. Furthermore, analyses based on longer speech samples outperformed those using shorter samples. As sample size increased, standard deviation values for both intra and inter-speaker similarity scores decreased, indicating reduced variability in estimating speaker similarity/dissimilarity levels in longer speech stretches compared to shorter ones. The study also uncovered varying degrees of likeness among identical twins, with certain pairs presenting a greater challenge for ASR systems. These outcomes align with prior research and are discussed within the context of relevant literature.

Magneto-optical characterization of TCO films using standard and enhanced configurations

Thin film samples like transparent conducting oxides (TCO) are typically investigated using measurements like Hall Effect and 4-point probe measurements. We use a sensitive AC Faraday rotation (FR) setup to study thin film samples for which a magneto-optic response is challenging to characterize. The experimental setup employs a stabilized He-Ne laser (633 nm) along with an AC magnetic field that enables lock-in detection. We investigate a series of TCO samples that are deposited on a glass substrate. The TCO samples include the more widely used Indium Tin Oxide (ITO) and the relatively newer Fluorine doped Tin Oxide films, usually referred to as FTO. These films have a magneto-optic response due to the presence of free carrier concentration and therefore measurement of this response (Verdet constant) could allow one to determine the carrier concentration of these films. Given that magneto optic responses like FR depend on the length of the sample length traveled by light, these sub-micron films pose considerable challenges in trying to extract the FR response of the film from that of the much thicker glass substrate. Furthermore, we present details of the design and FR characterization of samples using a Michelson interferometer-based measurement setup which enhances the Faraday rotation and affords a new means of studying harmonic peaks of the recorded optical signal in response to a sinusoidally-varying applied magnetic field. We compare some early results from this setup to the typical “single-pass” setup to highlight the difference in the recorded signals from the two setups. To showcase the advantages of the proposed measurements, we also include some early results from a very different type of sample, namely superparamagnetic nanoparticles (SNPs).