Lobe Size Research Articles

Lacrimal gland activity in lacrimal drainage obstruction: exploring the potential cross-talk between the tear secretion and outflow

PurposeTo investigate the effects of lacrimal drainage obstructions on the lacrimal gland activity and if there exists a potential link between the two.MethodsDirect assessment of the lacrimal gland activity from...

Effects of the Parker spiral angle of the interplanetary magnetic field on the dawn-dusk asymmetry of the Martian magnetotail

Context. The draping of the interplanetary magnetic field (IMF) around unmagnetized planets induces a magnetotail with a two-lobe plasma structure. On Mars, due to the impact of the IMF Parker spiral angle, the structure of its induced magnetotail is dawn-dusk asymmetric. Observational and numerical studies have shown the dawn-dusk asymmetric size of magnetic lobes and the shift of the polarity reversal layer and the inverse polarity reversal layer under different Parker spiral angles. Variation in the tail-region induced magnetic field with the Parker spiral angle is important in the evolution of the magnetotail. Further studies should investigate the influence of the magnetic pressure and field direction on the magnetic lobe structure and plasma boundary locations, as well as the relationship between the polarity reverse of the IMF and the Parker spiral angle. Aims. This study aims to investigate the dawn-dusk asymmetric structure of the Martian magnetotail under different Parker-spiral IMF orientations. In this study, we used a multispecies magnetohydro-dynamic (MHD) model, which has been shown to self-consistently calculate the Mars-solar wind interaction, to investigate the effects of the Parker spiral angle on the structure of the Martian magnetotail. By comparing the magnetic field, large-scale configurations, and plasma boundary locations across various cases, we aim to clarify how variations in the IMF Parker spiral angle affect the magnetic pressure and field direction in the magnetotail and the locations and shapes of the magnetic lobes, polarity reversal layer, and inverse polarity reversal layer. Methods. A three-dimensional and parallelized multispecies MHD model was constructed to simulate the global solar wind interaction with Mars. Four ion species, H+, O2+, O+, and CO2+, as well as the chemical reactions between them, such as photoionization, charge exchange, and recombination, were considered in the model to accurately calculate the ion distributions in the magnetosphere and ionosphere of Mars. Three cases with Parker spiral angles of 90, 56, and 30 degrees were examined, representing the perpendicular, standard, and quasi-parallel IMF relative to the solar wind flow, respectively. Results. A symmetric magnetotail was reproduced in the case with a Parker spiral angle of 90° degrees. When the Parker spiral angle decreases, the magnetic pressure in the magnetic lobes reduces, and the flaring angle of the magnetic field becomes larger on the dawn side than on the dusk side. These two factors result in the shrinkage and extension of the magnetic lobes. Furthermore, the variation in magnetic pressure results in a polarity reversal layer bent toward the dawn side. Finally, we found that the inverse polarity reversal layer shrinks toward Mars with a decrease in the Parker spiral angle.

Petrocodonwui (Gesneriaceae), a new species from Guizhou, China.

Petrocodonwui F.Wen & R.B.Zhang (Gesneriaceae), a typically lithophyte occurring in the Danxia areas of north-western Guizhou, China, is described and illustrated as new to science. The new species shows overall similarity with P.chishuiensis Z.B.Xin, F.Wen & S.B.Zhou, which is also its sister species, based on molecular evidence. The new species can be distinguished from P.chishuiensis by the elongated rhizome, the relatively long indumentum on the peduncle, the shape, size and indumentum of calyx lobes, the location of the stamens in the corolla tube and the shape, size and indumentum of the stigma. We provide a diagnosis, detailed description, photographic images and a table with taxonomic notes to distinguish several other morphologically similar Petrocodon species.

356 Upregulated Genes in Age-Related Lobular Involution Stagnation Represent Potential Biomarkers That Link To Increased Breast Cancer Risk

OBJECTIVES/GOALS: Age-related lobular involution (LI) is a physiological process of breast epithelial regression that occurs primarily during perimenopause (ages 45-55); women in this age range for which the process of LI is delayed, defined as LI stagnation, show significantly increased risk of breast cancer as compared to LI progression patients. METHODS/STUDY POPULATION: The Mayo Clinic Benign Breast Disease (BBD) cohort includes ~1000 women who had multiple sequential benign biopsies. 103 patients were found to have sequential biopsies during the perimenopausal period, of which 10 eventually progressed to breast cancer. These patients were assessed for LI stagnation vs LI progression by quantifying 10 lobules per slide and comparing median acini number and median lobule size between initial and subsequent biopsies from the same patients. RNA was derived from whole tissue sections from the initial biopsies, and profiled using NanoString IO360 and BC360, which were normalized using RUVg methods. Differentially expressed genes associated with LI stagnation were defined as having two-tailed, unpaired p-values less than 0.05. RESULTS/ANTICIPATED RESULTS: Analysis showed subsetting patient sets by time between biopsies improves classification of stagnant vs. progression. Differential gene analysis identified 37 genes associated with LI stagnation and LI progression, and 20 of these genes were found to overlap a set of 128 gnese that were differentially expressed between women who subsequently developed breast cancer vs remained cancer-free. These genes represent potential biomarkers of processes that link LI stagnation and increased breast cancer risk. DISCUSSION/SIGNIFICANCE: In future studies, we intend to study these genes that were shown to be upregulated in LI stagnation for their association with subsequent development of breast cancer in independent cohorts of women with BBD. We will use this knowledge to improve individualized risk assessment, which will help focus surveillance and prevention strategies.

Novel metrics to characterize temporal lobe of very preterm infants on term-equivalent brain MRI.

Preterm birth adversely impacts brain development and contributes to neurodevelopmental impairment; the temporal lobe may be particularly vulnerable to the impact of very preterm (VP) birth. Yet, no prior magnetic resonance imaging (MRI) scoring system incorporated a method to quantify temporal lobe size in VP infants. We developed and applied three metrics (temporal lobe length, extra-axial space, and temporal horn width) to quantify temporal lobe structure on term-equivalent brain MRIs obtained from 74 VP and 16 term infants. We compared metrics between VP and term infants and explored associations of each metric with perinatal risk factors. All metrics had excellent reliability (intra-class correlation coefficient 0.62-0.98). VP infants had lower mean temporal lobe length (76.8 mm versus 79.2 mm, p = 0.02); however, the difference attenuated after correction for postmenstrual age. VP infants had larger temporal horn widths compared with term infants (2.6 mm versus 1.8 mm, p < 0.001). Temporal lobe length was positively associated with gestational age, birth weight, and male sex, and negatively associated with the duration of parenteral nutrition. The proposed metrics are reliable and sensitive in distinguishing differences in temporal lobe development between VP and full-term infants. We developed a novel method for quantifying temporal lobe size among very preterm infants at term equivalent using simple metrics performed on brain MRI. Temporal lobe metrics were reliable, correlated with brain volume from volumetric analysis, and were sensitive in identifying differences in temporal lobe development among preterm compared with term infants, specifically larger temporal horn size in preterm infants. This temporal lobe metric system will enable future work to delineate the perinatal and postnatal factors that impact temporal lobe growth, and better understand the relationship between temporal lobe disturbance and neurodevelopment in very preterm infants.

Evaluation of right liver lobe size to serum albumin concentration ratio in predicting the presence of esophageal varices in cirrhotic patients taking endoscopy as gold standard

Background: Cirrhosis with its complication is a major health concern in Pakistan. Endoscopy is an invasive and expensive modality for screening for esophageal varices which is one of the most common complication of liver cirrhosis. Research is being conducted to explore non-invasive markers that can replace this invasive technique. We aimed to evaluate the predictive value of the ratio of the size of the right lobe of liver to serum albumin concentration in prediction of the presence of esophageal varices.&#x0D; Methods: It was a cross-sectional study conducted at the Medicine Department, Ghurki Trust Teaching Hospital, Lahore from January 4 till July 31. The study included 297 patients of all the genders, aged 20-70 years, diagnosed cases of liver cirrhosis for at least 6 months and having suspected esophageal varices on right liver lobe size to serum albumin ratio &gt;4.1. All the patients were subjected to upper GI endoscopy to confirm predicted varices. Data was analyzed using SPSS 23.0. PPV of the ratio was calculated. Post-stratification chi square was used to find association (p value &lt;0.05 as significant).&#x0D; Results: The patients had a mean age of 51.5 ± 9.2 years with 180 (60.6%) male and 117 (39.4%) female patients. Diagnosis of esophageal varices was confirmed in 225 (75.8%) patients on endoscopy. There were 225 true positive and 72 false positive cases. Positive predictive value was 75.8%.&#x0D; Conclusion: The positive predictive value of the ratio of the size of the right liver lobe to serum albumin was statistically significant in predicting the presence of esophageal varices on upper GI endoscopy. These findings were not dependent on the patient's age, BMI, gender, duration of disease or serum bilirubin level.&#x0D; &#x0D; Cirrhosis, Esophageal Varices, Right Liver Lobe Diameter to Serum Albumin Ratio

Lóbulo hepático derecho fetal: nomograma por percentiles

Objective: To design a nomogram by percentiles of the fetal right liver lobe measurement in pregnant between 16 and 40 weeks of gestation who attend the Maternidad Concepción Palacios in the period between March and August 2020. Methods: A prospective, descriptive and cross-sectional study was conducted that included 350 patients with informed consent, were measured fetal right liver lobe, related to gestational age, based on the date of the last menstruation or ultrasound of the first trimester, and associated with weight, size and maternal body mass index. Results: An average fetal right liver lobe measurement of 37.42 ± 12.03 mm (Min 13 and max 62 mm) was obtained. The regression analysis yielded a correlation coefficient between fetal right liver lobe size and gestational age of 0.950. The determination coefficient obtained was 0.903. Depending on the result of the variance analysis, there is an association between the two variables (p-0.000). A fetal right liver lobe increase measurement of + 1,585 per week (95% CI - 1,531 - 1,640) (p-0.000) was obtained. The percentile nomogram was constructed. There was no relationship between the measurement and maternal weight and height, but there was with the body mass index. Conclusion: The fetal right liver lobe, as an expression of the liver measure, grows relative to the increase in gestational age and this allowed to design a nomogram per percentiles.

Updated imaging and phylogenetic comparative methods reassess relative temporal lobe size in anthropoids and modern humans.

Two decades ago, Rilling and Seligman, hereafter abbreviated to RAS Study, suggested modern humans had relatively larger temporal lobes for brain size compared to other anthropoids. Despite many subsequent studies drawing conclusions about the evolutionary implications for the emergence of unique cerebral specializations in Homo sapiens, no re-assessment has occurred using updated methodologies. We reassessed the association between right temporal lobe volume (TLV) and right hemisphere volume (HV) in the anthropoid brain. In a sample compiled de novo by us, T1-weighted in vivo Magnetic Resonance Imaging (MRI) scans of 11 extant anthropoid species were calculated by-voxel from the MRI and the raw data from RAS Study directly compared to our sample. Phylogenetic Generalized Least-Squares (PGLS) regression and trait-mapping using Blomberg's K (kappa) tested the correlation between HV and TLV accounting for anthropoid phylogeny, while bootstrapped PGLS regressions tested difference in slopes and intercepts between monkey and ape subsamples. PGLS regressions indicated statistically significant correlations (r2 < 0.99; p ≤ 0.0001) between TLV and HV with moderate influence from phylogeny (K ≤ 0.42). Bootstrapped PGLS regression did not show statistically significant differences in slopes between monkeys and apes but did for intercepts. In our sample, human TLV was not larger than expected for anthropoids. Updated imaging, increased sample size and advanced statistical analyses did not find statistically significant results that modern humans possessed a disproportionately large temporal lobe volume compared to the general anthropoid trend. This has important implications for human and non-human primate brain evolution.

Lateral Buckling of an Elastic Pipe on a Frictional Seabed

Abstract Pipelines tend to buckle laterally under thermal expansion. In existing analytical solutions by Kerr and Hobbs, it is assumed that the seabed resistance q0 to lateral pipe movements is constant in magnitude and opposite in direction to the total displacement. Here, it is opposite to the velocity instead, i.e., the seabed is taken to be frictional rather than nonlinear elastic with a V-shaped potential function. A three-lobe (“mode 3f”) analytical solution is provided for the frictional case, using the same approximate end-of-buckle condition v = v′ = v″ = 0 used by Hobbs in his “mode 3” solution for the nonlinear elastic case. For both modes 3 and 3f solutions, the shape of the buckle does not change as it grows with increasing thermal expansion, though the scaling factors in the axial and lateral directions are different, i.e., the solutions are self-similar. A single finite element solution for the frictional case with an initial imperfection imposed by a bumper can be scaled to cover all such cases. It shows that the shape of the buckle depends on the amplitude of the initial triggering imperfection and is close to the mode 3f solution for very small initial imperfections. The difference between modes 3 and 3f is significant in regard to buckle shape and the relative size of the buckle lobes, but small in regard to the maximum bending moment for a given amount of thermal expansion accommodated by the buckle.

Three Zone Scanning Protocol For Lung Ultrasound: An Anatomical Basis.

Lung ultrasound is rapidly gaining popularity based on point of care ease of use, diagnostic fidelity and lack of ionizing radiation. This was particularly notable at the beginning of the COVID-19 pandemic, where concerns of contamination of the x-ray department led to a reluctance to order frequent chest x-rays. Early COVID-19 lung involvement is of a bronchopneumonia, and patches of consolidation adjacent to the chest wall were easily detectable by ultrasound. A large number of proposed scanning protocols were advocated and are often complex and largely based on traditional stethoscope examination or access points on the chest wall rather than the underlying lung anatomy. A surgical understanding of lung anatomy and related surface anatomy has led us to develop a simplified three zone scanning protocol in 2013. The anterior zone corresponds to the upper lobe, and the posterior zone is divided between upper lobe and lower lobe. The relationship between lung lobes and the surface of the chest wall provides the anatomical basis for a simple three scanning zone lung ultrasound protocol.

New insights on Polianthes montana (Asparagaceae, Agavoideae) and the description of P. aarodriguezii a new species, both from Sierra Madre Occidental, Mexico

Botanical explorations in Sierra Madre Occidental, Mexico resulted in the location of new populations of Polianthes montana in the south of Durango state. This species is little known and there are conflicts on its identification and geographic distribution range, for these reasons here are provided discussions and an extended morphological description. Also, additional individuals from a Polianthes population were collected almost on the border of the states of Durango and Sinaloa, and after a rigorous analysis of the specimens, it was concluded that they do not belong to any of the known taxa in the genus and it is proposed here as a new species that morphologically resembles P. alboaustralis and P. montana but differs from the former in having (1–)3–4 ensiform leaves (vs. 2–6 linear), raceme inflorescence (vs. spike), perigone without a nectary (vs. nectary present in the floral tube), and filaments 6.5–9.7 mm long (vs. 2–10 mm long). From P. montana, it differs in the perigone size (5–5.5 × 0.4–0.7 cm vs. 2–2.8 × 0.3–0.5 cm), the orientation and size of perigone lobes (diffuse to divergent, 5.6–6.8 × 3.4–5 mm vs. adpressed to assurgent, 2.4–3 mm × 1.9–2.3 mm), longer filaments (6.5–9.7 mm vs. 5–5.4 cm), and styles (4.2–4.8 cm vs. 1.7–2 cm). Photographs, notes on phenology, geographic distribution, conservation status, and habitat are included, along with a map and an identification key to Polianthes subgenus Polianthes.

Self-Assembly in an Experimentally Realistic Model of Lobed Patchy Colloids.

Colloids with lobed architectures have been shown to self-assemble into promising porous structures with potential biomedical applications. The synthesis of these colloids via experiments can be tuned to vary the number and the position of the lobes. However, the polydispersity involving the numbers, sizes, and the dispositions of lobes, that is often observed in particle designs, can significantly affect their self-assembled structures. In this work, we go beyond the uniform lobe size conditions commonly considered in molecular simulations, and probe the effect of polydispersity due to non-uniform lobe sizes by studying self-assembly in three experimentally observable designs of lobed particles (dumbbell, two lobes; trigonal planar, three lobes; and tetrahedral, four lobes), using coarse-grained Langevin dynamics simulations in the NVT ensemble. With increasing polydispersity, we observed the formation of a crystalline structure from a disordered state for the dumbbell system, and a loss of order in the crystalline structures for the trigonal planar system. The tetrahedral system retained a crystalline structure with only a minor loss in compactness. We observed that the effect of polydispersity on the self-assembled morphology of a given system can be minimized by increasing the number of lobes. The polydispersity in the lobe size may also be useful in tuning self-assemblies toward desired structures.

Goiter size changes as an indicator of response to treatment following selenium intake, and its correlation with goiter type

Introduction: Goiter is a common problem in the world; however, it is more prevalent in countries with iodine deficiency. Goiter has different etiologies while one of them is Hashimoto’s thyroiditis. Selenium is a trace element that has different important effects in the body. It has also some effects in the thyroid. Objectives: This study aimed to evaluate the effect of selenium intake on goiter size and the correlation with goiter type. Patients and Methods: In prospective observational study, 20 patients with Hashimoto’s goiter and 40 patients with non-Hashimoto’s goiter were evaluated for thyroid sizes. The nodule sizes were else evaluated. After the first evaluation, daily selenium supplement (200 mg) was prescribed for all patients for six months. After this time, the sizes of goiter and nodules were measured again. Results: Results showed that the size of both goiter lobes in both Hashimoto’s and non-Hashimoto’s groups was significantly reduced before and after selenium intake (P&lt;0.001). The reduction rate in left lobe size in patients with Hashimoto’s goiter was 50.73% and in nonHashimoto’s goiter patients was 20.89% (P&lt;0.001). The reduction rate in right lobe size in patients with Hashimoto’s goiter was 53.37% and in non-Hashimoto’s goiter was 20.46 (P&lt;0.001). Conclusion: We conclude that administration of selenium is effective in reducing the size of the goiter.

Optimisation of data acquisition towards continuous cardiac Magnetic Resonance Fingerprinting applications

PurposeAssess and optimise acquisition parameters for continuous cardiac Magnetic Resonance Fingerprinting (MRF). MethodsDifferent acquisition schemes (flip angle amplitude, lobe size, T2-preparation pulses) for cardiac MRF were assessed in simulations and phantom and demonstrated in one healthy volunteer. Three different experimental designs were evaluated using central composite and fractional factorial designs. Relative errors for T1 and T2 were calculated for a wide range of realistic T1 and T2 value combinations. The effect of different designs on the accuracy of T1 and T2 was assessed using response surface modelling and Cohen’s f calculations. ResultsLarger flip angle amplitudes lead to an improvement of T2 accuracy and precision for simulations and phantom experiments. Similar effects could also be shown qualitatively in in-vivo scans. Accuracy and precision of T1 were robust to different design parameters with improved values for faster flip angle variation. Cohen’s f showed that T2-preparation pulses influence the accuracy of T2. The number of pulses used is the most important parameter. Without T2-preparation pulses, RMSE were 3.0 ± 8.09 % for T1 and 16.24 ± 14.47 % for T2. Using those pulses reduced the RMSE to 2.3 ± 8.4 % for T1 and 14.11 ± 13.46 % for T2. Nonetheless, even if the improvement is significant, RMSE are still too high for reliable quantification. ConclusionIn contrast to previous study using triggered MRF sequences using < 30° flip angles, large flip angle amplitudes led to better results for continuous cardiac MRF sequences. T2-preparation pulse can improve the accuracy of T2 estimation but lead to longer scan times.

Modeling of High-Pressure and High-Temperature Microemulsion Experiments using HLD-NAC-Based Equation of State

Summary Surfactant flooding is a promising technique that can reduce interfacial tension (IFT) between oil and water to ultralow values, mobilizing previously trapped oil. For reservoirs at moderate to high pressures, understanding and modeling how pressure affects the phase behavior of a surfactant-brine-oil system is important to the design and implementation of an efficient/cost-effective surfactant flooding project. Typically, however, phase behavior experiments and models of that phase behavior are made only at low pressures. The main objective of this paper is to show how to model experimental data in a unified way for a large range of pressure, temperature, and other parameters, using hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC)-based equation-of-state (EOS). Pressure and temperature scans show that pressure has a significant effect on the surfactant microemulsion phase behavior, shifting it from an optimal three-phase system at low pressure to a nonoptimal two-phase system at high pressure. Further, multiple scans at different water/oil ratios (WORs) show a shift in the optimum indicating that phase behavior partitioning of the various components is changing with oil saturation. We obtained good fits of all experimental data including all two- and three-phase regions using a single tuned HLD-NAC EOS for a wide range of simultaneous variations in pressure, temperature, salinity, and overall composition. Such a simultaneous match and prediction by a single set of model parameters has never been done before. We also demonstrate the type of data needed for an accurate EOS. When input into a numerical simulator, the tuned EOS improves the predictions of the resulting phase behavior (size and shape of the two-phase lobes and three-phase regions) and IFTs with changing pressure, temperature, salinity, WORs, and surfactant/alcohol concentrations.

Superoscillation focusing with suppressed sidebands by destructive interference.

Optical superoscillation, a phenomenon that the local optical field can oscillate much faster than that allowed by its highest harmonic, can significantly overcome the Abbe diffraction limit. However, as the spot size is compressed below the superoscillation criteria of 0.38λ/NA, huge sidebands will inevitably appear around the central lobe with intensity hundreds of times higher than that of the central lobe. Here, we propose an approach to realize superoscillation by using destructive interference. The central lobe size can be compressed beyond the superoscillation criteria without formation of strong sidebands by destructive interference between focused fields. Such a super-resolution metalens can find its application in label-free far-field super-resolution microscopy.

Morphological markers of ear print in Iraqi population

The outer ear is an emerging biometric that has drawn the attention of the research community for more than a decade. Empirical studies confirm, that the shape of the outer ear is unique, and it is also assumed to be stable throughout a human life time. An ear print is a two-dimensional depiction of the external ear pieces that have got into contact with a surface. In 1965, the first criminal ear print identification was made in Switzerland. The variation in shape and size of ear features makes it richer biometric tool than face. Material and method: The study performed a qualitative discrimination of the external ear shape of 143 individuals, including lobe size, lobe attachment, helix rolling, ear protrusion, and antihelix folding, by using ear photographs. Results: Six landmarks were evaluated for auricle morphometry in both sexes. There was variation in the morphological features of the external ear of the sampled subjects. The external ear features vary in both sexes. All variables were statistically significant (p ≤ 0.05). The triangle-shaped ear was prevalent in females and males had an oval shape. ear print

Evolution of the Heliotail Lobes over a Solar Cycle as Measured by IBEX

Energetic neutral atom (ENA) measurements by IBEX reveal that the heliotail comprises an energy-dependent multilobe structure. We examine the heliotail evolution over 11 yr of IBEX observations covering a full solar cycle (SC). We find the following: (1) The heliotail structure persists over the entire SC, comprising three ENA-enhanced and two ENA-suppressed lobes. (2) Lobe sizes and locations are generally stable but exhibit variations in ENA fluxes driven by the SC. (3) Lobe centers follow a cyclic behavior over multiple SC phases, indicating direct signatures of slow and fast solar wind (SW) interactions in the inner heliosheath (IHS). (4) The tilted plane passing through the port–starboard lobes’ centers oscillates in latitude but maintains its tilt from the ecliptic plane, likely a consequence of the interstellar magnetic field draping around the heliosphere. (5) The transition of the central heliotail from a single lobe at ∼1.1 keV to two lobes above ∼2 keV is SC-dependent and directly reflects the IHS plasma properties, i.e., when ENA fluxes from fast SW from the polar coronal holes change over time. (6) The central lobe exhibits a substructure that is enhanced and offset from the downwind direction, possibly indicating an asymmetric ENA emission or an asymmetry in the parent plasma distribution. These results reveal the general stability of the heliotail structure over time and distinct variations in individual lobes’ properties in relation to the SC phases. Furthermore, results show the effects of multiple SC phases in the tail, reflecting different ENA travel times and source histories.

Implementation of a System for Assessing the Quality of Spoken English Pronunciation Based on Cognitive Heuristic Computing.

This paper analyzes and investigates the quality assessment of spoken English pronunciation using a cognitive heuristic computing approach and designs a corresponding spoken pronunciation quality assessment system for practical training. Using the general Goodness of Pronunciation assessment algorithm as a benchmark, the shortcomings of the traditional Goodness of Pronunciation method are explored through statistical experiments, and the validity of the overall posterior probability output from the speech model for pronunciation quality assessment is verified. For the analysis of rhythm, there is no common algorithm framework, but in this paper, the F0 similarity algorithm based on dynamic time regularization and the stop similarity algorithm based on forced alignment is proposed for the two main factors of rhythm, intonation, and pause, respectively. After framing, the Hamming window processing is used to make the signal smoother, reduce the side lobe size after fast Fourier transform processing, and solve the problem of spectrum leakage. Compared with the ordinary rectangular window function, the Hamming window can obtain a higher quality spectrum. And combined with CTC for speech recognition modeling, the recognition rates are comparable in the case of using BLSTM and bidirectional threshold cyclic unit BGRU as the hidden layer unit, respectively, and the training time is 23% less than BLSTM using BGRU; in addition, the BGRU-CTC model is improved by using a 2-BGRU-CTC model with 256 hidden layer nodes, so that the error rate of phoneme recognition is reduced to 33%. The effectiveness of the algorithm framework is also verified through experiments, which further proves the effectiveness of our proposed phoneme segment feature and rhyme similarity algorithm.

Research on Coded Excitation Using Kasami Sequence in the Long Rail Detection Based on UGW

For a broken rail detection system based on ultrasonic guided waves (UGW), the multimodal and dispersion characteristics of UGW degrade signal-to-noise ratio (SNR) and range resolution. To improve the SNR of the received signals and range resolution, the coded excitation based on Kasami sequences is presented in this work. Utilizing a PSpice model of piezoelectric ultrasonic transducers, as well as conducting field tests based on the pitch–catch mechanism, it is shown that encoded UGW signals can increase the SNRG (the gain of SNR) by 6.29 dB. The main lobe width of the coded excitation is mainly determined by the number of carrier cycles and the carrier waveform, and the size of the side lobes is mainly determined by the number of coding bits. To quickly identify the corresponding transmissions at the receivers, a peak detection algorithm is shown. It is based on bandpass filter, triangle filter and Hilbert transform. Its accuracy and effectiveness are validated by using some field tests under different distances. It can be concluded that the shown adaptive peak algorithm has strong robustness and immunity to noise.