115 research outputs found
A novel Bezier curve control point search algorithm for autonomous navigation using N-order polynomial search with boundary conditions
The study on path planning at intersections such as roundabouts has become a crucial aspect for autonomous vehicle development. This is due to the nature of the intersections, which can vary depending on the level of complexity. Path generation for an autonomous vehicle in a roundabout cornering is done using different curve fitting methods such as clothoid curves, Bezier curves, etc. However, the Bezier curve is the most widely used in the curve fitting algorithm for vehicle path planning as it can generate a possible number of path maneuvers. However, the main challenge when using the Bezier curve fitting algorithm is finding its control points. The control points are a crucial part of Bezier curve generation as it determines the curvature and shape of the curve. Therefore, a new technique for finding the control points of a Bezier curve is presented in this paper. The process starts with random points selection along the path. Specific random points will be selected through which the curve should pass through. The algorithm then expands the generalized Bezier curve equations to solve the mathematical problem and eventually, the simultaneous equation will be formed for the control point generation. The generated control points will be able to generate a proper Bezier curve that passes through all the selected points along the path. The generated equations are further validated in a test case study to show the effectiveness of the proposed method. This method is able to generate the desired Bezier curve through the selected points. This will open possibilities to generate a smoother predictive motion output using the Bezier curve fitting technique
MULTIPLE OIL PAD DETECTION USING DEEP LEARNING
Deep learning (DL) algorithms are widely used in object detection such as roads, vehicles, buildings, etc., in aerial images. However, the object detection task is still considered challenging for detecting complex structures, oil pads are one such example: due to its shape, orientation, and background reflection. A recent study used Faster Region-based Convolutional Neural Network (FR-CNN) to detect a single oil pad from the center of the image of size 256 × 256. However, for real-time applications, it is necessary to detect multiple oil pads from aerial images irrespective of their orientation. In this study, FR-CNN was trained to detect multiple oil pads. We cropped images from high spatial resolution images to train the model containing multiple oil pads. The network was trained for 100 epochs using 164 training images and tested with 50 images under 3 different categories. with images containing: single oil pad, multiple oil pad and no oil pad. The model performance was evaluated using standard metrics: precision, recall, F1-score. The final model trained for multiple oil pad detection achieved a weighted average for 50 images precision of 0.67, recall of 0.80, and f1 score of 0.73. The 0.80 recall score indicates that 80% of the oil pads were able to identify from the given test set. The presence of instances in test images like cleared areas, rock structures, and sand patterns having high visual similarity with the target resulted in a low precision score
INFLUENCE OF ADDITIONAL SPECTRAL BANDS FOR EPIPHYTE SEGMENTATION ON DRU-NET
Dense Residual U-Net (DRU-Net) is a neural network used for image segmentation. It is based on the U-Net architecture and isa combination of modified ResNet as the encoder and modified DenseNet as the decoder blocks. DRU-Net captures both the local and contextual information. Previous studies on DRU-Net have not tested the influence of the spectral resolution of the images. In an earlier study, the DRU-Net was trained with grayscale images for epiphyte segmentation. The network trained and tested with grayscale images underperformed while varying the illumination and occupancy of the target in the frame. In this study, the same network was trained and tested with RGB images for assessing the increase in overall learning. The performance of the network in segmenting epiphytes under conditions such as good/poor illumination and high/low target occupancy was analyzed. Dice and Jaccard scores were used as evaluation metrics. The DRU-Net model trained with RGB images had an improvement of 20% over the grayscale model in both average Dice and average Jaccard scores of the target class. Based on the higher Dice and Jaccard scores, adding additional spectral information improves DRU-Net learning. The increased computation time required for training DRU-Net with RGB images will result in better output. This model could be further used for identifying multiple epiphytes in images with poor illumination and different occupancy conditions
Frozen Section Evaluation in Head and Neck Oncosurgery: An Initial Experience in a Tertiary Cancer Center
Objective: Frozen section evaluation is routinely used by oncosurgeons across specialties for rapid assessment of the presence of tumor in any tissue and its most common use is in surgical margins. Today, the use of intraoperative frozen-section evaluation of surgical margins is an accepted and frequent practice in head and neck oncology. This study aims to determine the efficacy and accuracy of frozen sections in head and neck cancer patients and compare the results with the respective paraffin sections and also to analyze the reasons for any disparity between them.
Material and Method: A retrospective study was conducted to evaluate efficacy and accuracy of frozen section in head and neck cancer of 265 patients, treated at a tertiary cancer centre hospital between January 2013 to December 2014.
Results: Out of 265 cases, it was found that 12.6% of these sections showed true positivity, 6.3% false positivity, 2.9% false negativity and 78.2% true negativity. The study also shows a sensitivity of 82.05% and specificity of 96.46%.
Conclusion: Our study shows that intraoperative frozen section reports are specific and highly sensitive. We recommend a minimum of 3-4 sections, optimum cryostat temperature, good section thickness and quality staining for a good concordance rate
Suzuki-Miyaura coupling under microwave enhanced conditions: Synthesis of 2-(hetero)aryl benzimidazoles
An expedient, palladium-mediated cross-coupling approach to functionalize the benzimidazole-based core under microwave-assisted conditions has been developed and is described. This protocol, which incorporates appendage diversity on this potential scaffold, is found to be compatible with a wide range of electronicallyand sterically-divergent (hetero)aryl boronic acids. The use of the PdCl2/(SPhos) catalytic system allows the formation of a stable and highly active LPd(0) species which was found to be critical for the successful synthesis of these novel, pharmacologically-relevant molecules. © AUTHOR(S).Russian Foundation for Basic Research, RFBR: 170300641AThe authors are thankful to SAIF, Indian Institute of Technology, Madras, for providing all the analytical data and spectra. Vasiliy A. Bakulev is thankful to Russian Foundation for Basic Research (Grant # 170300641A)
Assessment of growth responses of Wistar rats fed with a diet containing composite flour premix
Composite flour technology involves the process of mixing cereals and legumes to facilitate the usage of locally available raw materials to produce high-quality food products economically. The present investigation evaluated the growth responses of a composite flour blend formulated using selected cereals, pulses and oil seed (a total of nine grains) were evaluated in two-month-old growing Wistar rats. The feeding trial was conducted for four weeks after an acclimatization period of five days. Daily feed intake and weekly body weight were recorded and parameters such as weight gain, feed conversion efficiency and digestibility of protein were estimated. A significantly higher average final live weight, weekly weight gain and better feed conversion efficiency (p<0.05) were observed in the treatment group. The observed values of digestibility of protein were 84.74 ± 0.85 % and 65.16 ± 0.89 % respectively for the treatment and control diets. Data were analyzed statistically using Analysis of Variance in SPSS 24 software. The investigation revealed that the formulated composite flour premix promotes growth with good protein digestibility in rats and could be used for nutraceutical fortifications to support human life and good health
A rare presentation of Pulmonary Lymphangitic Carcinomatosis in cancer of lip: case report
Squamous cell carcinoma of lip is a common malignancy in Indian subcontinent. Metastatic spread is infrequent. Although advanced tumours spread to lymph nodes in the neck, it does not typically present with lung metastasis or with lymphangitic carcinomatosis. We describe a patient who developed cough and increasing dyspnoea while on treatment for carcinoma of lip. Chest x-ray and computed tomography were consistent with lymphangitic carcinomatosis. Lymphangitic carcinomatosis occurs with many different primary tumours and can rarely occur in oral cancers. This is the first report from carcinoma of lip
Measuring the stability of fundamental constants with a network of clocks
The detection of variations of fundamental constants of the Standard Model would provide us with compelling evidence of new physics, and could lift the veil on the nature of dark matter and dark energy. In this work, we discuss how a network of atomic and molecular clocks can be used to look for such variations with unprecedented sensitivity over a wide range of time scales. This is precisely the goal of the recently launched QSNET project: A network of clocks for measuring the stability of fundamental constants. QSNET will include state-of-the-art atomic clocks, but will also develop next-generation molecular and highly charged ion clocks with enhanced sensitivity to variations of fundamental constants. We describe the technological and scientific aims of QSNET and evaluate its expected performance. We show that in the range of parameters probed by QSNET, either we will discover new physics, or we will impose new constraints on violations of fundamental symmetries and a range of theories beyond the Standard Model, including dark matter and dark energy models
Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences
observed through gravitational waves so far, the astrophysical origin of these
binaries remains uncertain. Orbital eccentricity is one of the clearest tracers
of binary formation channels. Identifying binary eccentricity, however, remains
challenging due to the limited availability of gravitational waveforms that
include effects of eccentricity. Here, we present observational results for a
waveform-independent search sensitive to eccentric black hole coalescences,
covering the third observing run (O3) of the LIGO and Virgo detectors. We
identified no new high-significance candidates beyond those that were already
identified with searches focusing on quasi-circular binaries. We determine the
sensitivity of our search to high-mass (total mass ) binaries
covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to
compare model predictions to search results. Assuming all detections are indeed
quasi-circular, for our fiducial population model, we place an upper limit for
the merger rate density of high-mass binaries with eccentricities at Gpc yr at 90\% confidence level.Comment: 24 pages, 5 figure
One-step generation of conditional and reversible gene knockouts
Loss-of-function studies are key for investigating gene function, and CRISPR technology has made genome editing widely accessible in model organisms and cells. However, conditional gene inactivation in diploid cells is still difficult to achieve. Here, we present CRISPR-FLIP, a strategy that provides an efficient, rapid and scalable method for biallelic conditional gene knockouts in diploid or aneuploid cells, such as pluripotent stem cells, 3D organoids and cell lines, by co-delivery of CRISPR-Cas9 and a universal conditional intronic cassette.A.A.-R. and K.T. are supported by the Medical Research Council, A.M. is supported by Wntsapp, Marie Curie ITN. J.F. and J.C.R.S. are supported by the Wellcome Trust. W.C.S. received core grant support from the Wellcome Trust to the Wellcome Trust Sanger Institute. B.-K.K. and R.C.M. are supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society (101241/Z/13/Z) and receive a core support grant from the Wellcome Trust and MRC to the WT–MRC Cambridge Stem Cell Institute
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