IMPLEMENTATION OF ACOUSTIC DOPPLER CURRENT PROFILER FOR MEASUREMENT OF VELOCITY OF WATER

This paper gives design of Acoustic Doppler Current Profiler. It is used for measuring the water profile. This can be mounted on the walls of bridges, below the underwater vehicle and can be fitted at the bottom of the water column. It gives readings not just at the bottom or top surface but gives throughout the water column. Basicprinciple used in this is Doppler Effect. This design is working on the 40 KHz frequency.Newadditions can also be done for theremoval of noise etc

Review on Ultrasonic Techniques for Underwater Object Classification

ABSTRACT: Underwater object classification is an attractive approach using acoustic remote sensing techniques due to its high coverage capabilities and limited costs as compared to manual method of taking samples from the seafloor. This review paper focuses on the characterization of underwater objects in a coastal environment using different ultrasonic techniques like multibeam echosounder (MBES), a single-beam echosounder (SBES) and sidescan sonar(SSS). Out of these ultrasonic techniques, MBES and SBES are, in general, high-frequency techniques providing information about bathymetry and backscatter for the upper part of the sea bottom. MBES systems provide this information with a better resolution due to the beam opening angle of typically 1 -3 , and high coverage. An SBES provides measurements directly underneath the ship only, but is widespread. For MBES underwater object classification is achieved through the Bayesian approach, employing backscatter measurements per beam. For the SBES, echo shape parameters of the transmitted signal are determined and are combined in a principal component analysis (PCA). Underwater object classification using these ultrasonic techniques is useful for a large range of applications, such as habitat mapping, cable laying, or mine hunting. KEYWORDS: Underwater object classification, single-beam echosounder (SBES), multi-beam echosounder (MBES), backscatter measurement, sidescan sonar(SSS) I.INTRODUCTION The knowledge of oceanic environment is found to be necessary for many applications, such as coastal engineering, marine geology and marine biology [1]. Also, the environment needs to be known accurately when evaluating the acoustic propagation characteristics in shallow-water environments, e.g., for sonar performance assessment. Hence this motivates us for gathering of information about properties of the water column, under water objects that is the watersediment interface and the deeper sediment layers. The classical technique applied for gathering of information for underwater objects is based on taking samples of the sediment but these techniques are very costly, time consuming and doesn't give enough information as measurements are taken at point positions only. Hence this review paper is dedicated to methods allowed for underwater sediment classification using ultrasonic techniques such as multibeam echosounders (MBESs), e.g., [2]-[4]; single-beam echosounders (SBESs), e.g., [5]-[7]; and sidescan sonars (SSSs), e.g.

CLASSIFICATION OF UNDERWATER SEDIMENTS USING ACOUSTIC SIGNAL PROCESSING METHOD

Acoustic reflected signals are the most acceptable technology which carries the information of the underwater objects based on frequency, amplitude. The reflected echo carries information about the material characteristics based on absorption, reflection and refraction. In this paper a computer simulation program is developed to classify the underwatersedimentsbased on the acoustic reflected signals. This computer simulation program also realizes the mechanism ofacoustic signal propagating through the underwater layer media accounting for attenuation effect

Review of Recent Development in Optical Fiber Technology

ABSTRACT:Fiber optic technology is dominating the market from a long time due to its high data rate, long distance transmission capability. Fiber optic technology has been proven to be a much better technology than metal wires. Signal loss is less in fiber optic and they are unsusceptible to interference. Less latency is a main requirement in many applications such as financial algorithmic trading and cloud computing, supercomputers. Fiber optics are used as data transmission medium in most of the telecommunication networks. Following are the area that are wieldy developed in the past decade: (1) material used in fabrication of fiber is silica, but now a days materials such as chalcogenide glasses, fluoroaluminate crystalline materials, fluorozirionate materials are used that will give larger infrared wavelength along with better transmission capability. (2) Fiber optic sensor field has shown remarkable development in the past few decade. Better sensor quality assure better reception of data. (3) New developments come to light in terms of technological aspect such as free-space technology

PERFORMANCE EVALUATION OF VARIOUS IMAGE-PROCESSING TECHNIQUES FOR THE MEASUREMENT OF WATER SURFACE VELOCITY

Long-muffle estimation of water speed is a testing undertaking. Diverse endeavoursto gauge flight in a liquid from a smooth stream with physical contact sensors couldn't deliver precise results. Estimation of water speed with direct contact sensor which results mechanical torment and high upkeep cost. Theexpectationof this paper is to utensils the non-contact water stream speed estimation framework scilicet in light of a picture based strategy. This paper shows a methodology for assessing water stream speed by taking after the development of particles through a progression of pictures. The picture based water stream estimation recognizes the worktop elements and measures their positions regarding this present reality by using Particle Matching based on Centroid Tracking Method & Block Matching Algorithm (BMA)

Land cover clustering and classification of satellite images

Land cover classification refers to the process of using remote sensing data to categorize different types of land cover like vegetation, water bodies and soil. This is helpful for gaining key information about the surface of the Earth and for the future interactions between human activities and the environment. These predicted interactions lead to the development of sustainable land use practices along with the protection of natural resources. This paper deals with classifying the land cover using unsupervised and supervised methods. The unsupervised method includes land cover detection using a K-means clustering algorithm and the supervised classification is done using random forest classifier. The evaluation parameter values are calculated and compared for the input and output images

PERFORMANCE EVALUATION OF VARIOUS IMAGE PROCESSING TECHNIQUE FOR THE MEASUREMENT OF WATER SURFACE VELOCITY

Long-muffle estimation of water speed is a testing undertaking. Diverse endeavoursto gauge flight in a liquid from a smooth stream with physical contact sensors couldn't deliver precise results. Estimation of water speed with direct contact sensor which results mechanical torment and high upkeep cost. Theexpect of this paper is to utensils the non-contact water stream speed estimation framework scilicet in light of a picture based strategy. This paper shows a methodology for assessing water stream speed by taking after the development of particles through a progression of pictures. The picture based water stream estimation recognizes the worktop elements and measures their positions regarding this present reality by using Particle Matching based on Centroid Tracking Method & Block Matching Algorithm (BMA)

Factors associated with unexplained sudden deaths among adults aged 18-45 years in India – A multicentric matched case–control study

Background & objectives: In view of anecdotal reports of sudden unexplained deaths in India's apparently healthy young adults, linking to coronavirus disease 2019 (COVID-19) infection or vaccination, we determined the factors associated with such deaths in individuals aged 18-45 years through a multicentric matched case–control study. Methods: This study was conducted through participation of 47 tertiary care hospitals across India. Cases were apparently healthy individuals aged 18-45 years without any known co-morbidity, who suddenly (<24 h of hospitalization or seen apparently healthy 24 h before death) died of unexplained causes during 1st October 2021-31st March 2023. Four controls were included per case matched for age, gender and neighborhood. We interviewed/perused records to collect data on COVID-19 vaccination/infection and post-COVID-19 conditions, family history of sudden death, smoking, recreational drug use, alcohol frequency and binge drinking and vigorous-intensity physical activity two days before death/interviews. We developed regression models considering COVID-19 vaccination ≤42 days before outcome, any vaccine received anytime and vaccine doses to compute an adjusted matched odds ratio (aOR) with 95 per cent confidence interval (CI). Results: Seven hundred twenty nine cases and 2916 controls were included in the analysis. Receipt of at least one dose of COVID-19 vaccine lowered the odds [aOR (95% CI)] for unexplained sudden death [0.58 (0.37, 0.92)], whereas past COVID-19 hospitalization [3.8 (1.36, 10.61)], family history of sudden death [2.53 (1.52, 4.21)], binge drinking 48 h before death/interview [5.29 (2.57, 10.89)], use of recreational drug/substance [2.92 (1.1, 7.71)] and performing vigorous-intensity physical activity 48 h before death/interview [3.7 (1.36, 10.05)] were positively associated. Two doses lowered the odds of unexplained sudden death [0.51 (0.28, 0.91)], whereas single dose did not. Interpretation & conclusions: COVID-19 vaccination did not increase the risk of unexplained sudden death among young adults in India. Past COVID-19 hospitalization, family history of sudden death and certain lifestyle behaviors increased the likelihood of unexplained sudden death