478 research outputs found

    Simulation of Cylindrical Resonator with Spiral Neck and Straight Neck to Attenuate the Low Frequency Noise of Muffler

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    This paper is concentrated for improving the transmission loss and reduces the low frequency noise level by development of Helmholtz Resonator within a limited space. The modified Helmholtz resonator, i.e. cylindrical resonator with spiral neck is used to occupy the small space. Introduction of spiral neck instead of straight neck with cylindrical cavity reduces the space of resonator. For first cut-off frequency (resonance frequency) the volume of resonator is fixed, so with the help of spiral neck its length increases, volume increases and its curvature effect is also helpful in the reduction of noise. The finite element analysis tool Comsol multiphysics is used to validate the result. The results shows interesting factor that resonator not only attenuate a particular low frequency noise as well it increases transmission loss with spiral neck. Helmholtz resonator with a spiral neck can achieve high sound reduction within a small space at low frequency

    A Partition Based Novel Approach in AFIS for Forensics & Security

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    AbstractMany automatic fingerprint identification approaches have been suggested. Amongst those various methods, the minutiae-based fingerprint demonstration and recognition is widely used. Minutiae based representation has some disadvantages in comparison to other fingerprint approached in terms of sample size. This paper describes a novel concept of partition based approach for fingerprint identification which aims to improve error rates as well as processing time in matching fingerprints. We aim to split the identity image into well separated partitions in order to simplify the identification task. Our system will use the gray-scale information of the fingerprints. The system will select the primary fingerprint, perform feature extraction & feature matching to identify the image in the database by comparing the featured values of both the fingerprints. Our implementation mainly incorporates image pre-processing, image partitioning, image binarization, feature extraction and feature matching. It finally generates a score which tells whether two fingerprints match or not

    Hyperparameter Optimization Techniques for Enhanced Diabetes Prediction Using XGBOOST

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    Data mining is crucial in healthcare since there is a mountain of data involved in disease diagnosis and analysis. Data analysis becomes exponentially more difficult under these circumstances, although they are not insurmountable. Health datasets are complicated and fraught with uncertainty; furthermore, they are arduous to manage and manipulate. One of the most significant healthcare issues impacting millions of people across the globe is diabetes. Diabetic early detection and prediction is crucial for initiating treatment in the early stages of the disease. Recent years have seen an exploration of machine learning in healthcare with the goal of assisting providers in making more accurate diagnoses and predictions about patient outcomes. In order to better anticipate cases of diabetes, this study investigates hyperparameter tuning with the Whale Optimisation Algorithm (WOA) in conjunction with the XGBoost machine learning method. The proposed approach utilizes 768 patient records from the Pima Indian Diabetes dataset in an effort to improve the efficiency and accuracy of disease prediction. Among the methodical processes included in the research are data preparation, hyperparameter identification, and WOA optimization. The optimized model shows encouraging accuracy and predictive performance outcomes when evaluated on a different dataset. Improving healthcare outcomes through the use of advanced machine learning and optimization techniques is the central focus of the research, as summarized in the abstract

    Role of regular yoga practice in improvement of various pulmonary parameters in first year medical students

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    Background: tress at any stage of life virtually produces several respiratory limitations and reduces tolerance to physical efforts, sometimes leading to pulmonary diseases in individuals. Various yoga and Pranayama like Kapalbhati and Nadi-sodhan involves powerful strokes of exhalation, which trains the subject to make full use of diaphragm and abdominal muscles.Methods: This study is performed on 1st yr. medical students whose stress level is in higher side due to academic burden. 55 medical students were selected as participants through counseling and were divided into Yoga group (n= 27) and control group (n=28). Pulmonary functions of subjects were tested using Pony FX advanced desktop spirometer manufactured by Cosmed. Yoga is performed 1 hr/day for 6 days /week for 12 weeks by yoga group.Results: Pulmonary functions tested in Yoga and control group were FVC, FEV1, PEF and FVC/FEV1. There were significant improvements in pulmonary functions in yoga group. In Yoga group (FVC- 5.8% increases, FEV1- 5.2% increase, PEF- 34% increase and FVC/FEV1- 3.15% increase). In control group also, all parameters increased but P value was not significant.Conclusions: This study concludes that practicing Yoga has shown a significant improvement on pulmonary functions in 1st year medical students

    Effect of traffic air pollution on spirometeric parameters in Eastern Uttar Pradesh population, India

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    Background: In the present era of the 21st century there are lots of discussion on environmental population and its impact on life and various clinical studies done to find out the effect of air pollution on respiratory physiology, particularly pulmonary functions. Pulmonary function tests give valuable information about lung physiology in health and disease. In the present study to assess the pulmonary function test between the population groups exposed to traffic related air pollution. Methods: A cross sectional retrospective cohort study was conducted in B R D Medical College. It was done on 73 males, out of which 35 were traffic policeman (15 smokers, 20 non- smokers) and remaining 38 belonged to non- exposed control group (15 smokers, 23 non-smokers). Pulmonary function tests (PFTs) were performed with computerized spirometer. The respiratory parameter was recorded and analyzed. To check statistical of data student t-test was performed.Results: Comparison of ratio FEV₁/FVC among two populations, revealed lower values for Traffic policeman group. This difference was significant among the non-smoker (P=0.0061), while not significant among the smoker (P=0.3419).Conclusions: The respiratory parameters were changed due to traffic related air pollution. So traffic related air pollution can be a risk factor in the development of respiratory obstruction

    Design and Analysis of Composite Rotor Blades for Active/Passive Vibration Reduction.

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    The problem of vibration has limited the use of helicopters in both civil and military applications. In this research, further analysis has been performed for the various on-blade approaches available for vibration reduction using a unique optimization framework. For passive optimization, an aeroelastic environment with several well-established analysis codes from different sources was developed that can be used to analyze and design composite rotor blades for minimum vibration or maximum performance. This design environment enables conceptual/early preliminary multidisciplinary rotor blade design with realistic structural properties for modern composite rotor blades. For the design of a rotor blade with active twist, a new design strategy was introduced where the amplitude of dynamic twist is maximized. The optimization framework included the aeroelastic design environment described earlier along with surrogate based optimization technique. The surrogate based optimization is performed in combination with Efficient Global Optimization algorithm. Results showed that the amplitude of dynamic twist is a true indicator of control authority of active twist rotor for vibration reduction. Furthermore, the optimization framework was extended to include discrete design variables in the optimization and the solution for mixed-variable design problem was obtained using three different techniques. After modifying the aeroelastic analysis to account for the presence of active flaps, a Mach-scaled composite rotor blade was designed using the same mixed design variable optimization framework to enhance the vibration reduction capabilities of the active flap. In this case also, the amplitude of dynamic twist was used as the objective function and the analysis was carried out at three different spanwise flap locations. This thesis also includes work related to the design and fabrication of a composite rotor blade with dual flaps which can be tested in a Mach-scaled spin test stand. Finally, the use of camber actuation with quadratic and cubic camber deformation shapes for vibration reduction and performance enhancement in dynamic stall region was studied. The aeroelastic analysis was augmented with a modified version of the ONERA dynamic stall model that accounts for morphing airfoil section.PHDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98006/1/deveshk_1.pd

    New Optimization Strategy for Design of Active Twist Rotor

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140683/1/1.j053195.pd
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