1,304 research outputs found

    A Graphical Approach to GPS Software-Defined Receiver Implementation

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    Global positioning system (GPS) software-defined receivers (SDRs) offer many advantages over their hardwarebased counterparts, such as flexibility, modularity, and upgradability. A typical GPS receiver is readily expressible as a block diagram, making a graphical approach a natural choice for implementing GPS SDRs. This paper presents a real-time, graphical implementation of a GPS SDR, consisting of two modes: acquisition and tracking. The acquisition mode performs a twodimensional fast Fourier transform (FFT)-based search over code offsets and Doppler frequencies. The carrier-aided code tracking mode consists of the following main building blocks: correlators, code and carrier phase detectors, code and carrier phase filters, a code generator, and a numerically-controlled oscillator. The presented GPS SDR provides an abstraction level that enables future research endeavors.Aerospace Engineering and Engineering Mechanic

    Extracting 3D Coordinates of Objects in Building Collapses from Drone Imagery

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    When out on a search and rescue mission, it is important to have tools that can easily keep track of the situation that is being handled. Autonomous drones have the ability to quickly collect a batch of images of the scene and its surroundings in order to provide emergency responders with an overview of what they are dealing with. These images are also used to identify hazardous anomalies such as tiny cracks on collapsed buildings. In many cases, however, identifying the exact location of these anomalies may be too difficult, especially when the anomaly is relatively minuscule in size when compared to the structure that it inhabits. The conducted research focuses on developing a system which search and rescue teams may utilize in order to extract the exact coordinates of any point found on an image taken by a drone. In order to do so, a series of images containing the scene of the area of interest is taken from a high altitude. Once that is completed, the images are loaded onto an application called Agisoft Metashape, where the images are combined in order to create a 3-Dimensional model of the location. Finally, the Image Coordinate Point Extraction algorithm, which was created using Metashape’s Python API, is run. The algorithm takes in an image as an input, presents it to the user, and asks the user to click a point on the image to extract its exact coordinate. In the case of this study, the entire process was tested on data from the Surfside Condominium building collapse that occurred in the summer of 2021

    QoS in Today's Internet

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    To be able to guarantee service quality end-to-end Quality of Service has to be deployed. This thesis addresses the problems with applying QoS end-to-end over today’s Internet. A rather pessimistic conclusion states that QoS over Internet is hard (impossible?) to realize without introducing virtual circuits or similar. The concept of flows and label switching is introduced. Some QoS techniques are presented

    Pulmonary and Cardiorenal Cyclooxygenase-1 (COX-1), -2 (COX-2), and Microsomal Prostaglandin E Synthase-1 (mPGES-1) and -2 (mPGES-2) Expression in a Hypertension Model

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    Hypertensive mice that express the human renin and angiotensinogen genes are used as a model for human hypertension because they develop hypertension secondary to increased renin-angiotensin system activity. Our study investigated the cellular localization and distribution of COX-1, COX-2, mPGES-1, and mPGES-2 in organ tissues from a mouse model of human hypertension. Male (n = 15) and female (n = 15) double transgenic mice (h-Ang 204/1 h-Ren 9) were used in the study. Lung, kidney, and heart tissues were obtained from mice at necropsy and fixed in 10% neutral buffered formalin followed by embedding in paraffin wax. Cut sections were stained immunohistochemically with antibodies to COX-1, COX-2, mPGES-1, and mPGES-2 and analyzed by light microscopy. Renal expression of COX-1 was the highest in the distal convoluted tubules, cortical collecting ducts, and medullary collecting ducts; while proximal convoluted tubules lacked COX-1 expression. Bronchial and bronchiolar epithelial cells, alveolar macrophages, and cardiac vascular endothelial cells also had strong COX-1 expression, with other renal, pulmonary, or cardiac microanatomic locations having mild-to-moderate expression. mPGES-2 expression was strong in the bronchial and bronchiolar epithelial cells, mild to moderate in various renal microanatomic locations, and absent in cardiac tissues. COX-2 expression was strong in the proximal and distal convoluted tubules, alveolar macrophages, and bronchial and bronchiolar epithelial cells. Marked mPGES-1 was present only in bronchial and bronchiolar epithelial cells; while mild-to-moderate expression was present in other pulmonary, renal, or cardiac microanatomic locations. Expression of these molecules was similar between males and females. Our work suggests that in hypertensive mice, there are (a) significant microanatomic variations in the pulmonary, renal, and cardiac distribution and cellular localization of COX-1, COX-2, mPGES-1, and mPGES-2, and (b) no differences in expression between genders

    Venous Thromboembolism in Cancer Patients

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    Moderating the Influence of Current Intention to Improve Suicide Risk Prediction

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    When assessors evaluate a person's risk of completing suicide, the person's expressed current intention is one of the most influential factors. However, if people say they have no intention, this may not be true for a number of reasons. This paper explores the reliability of negative intention in data provided by mental-health services using the GRiST decision support system in England. It identifies features within a risk assessment record that can classify a negative statement regarding current intention of suicide as being reliable or unreliable. The algorithm is tested on previously conducted assessments, where outcomes found in later assessments do or do not match the initially stated intention. Test results show significant separation between the two classes. It means suicide predictions could be made more accurate by modifying the assessment process and associated risk judgement in accordance with a better understanding of the person's true intention

    Managing paediatric eosinophilic gastroenteropathies: a community experience

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    Awareness and diagnoses of eosinophilic gastroenteropathies have increased over the past decade. We report 3 cases of eosinophilic gastroenteropathies in children who were diagnosed by endoscopy, allergy tested by skin prick and patch testing, and managed with the use of avoidance/elemental diets

    Revival of basic health services in Syria

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