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frequency</title> <meta name="description" content="Search results for: natural frequency"> <meta name="keywords" content="natural frequency"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none 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action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="natural frequency"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 9445</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: natural frequency</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9265</span> Machine Learning Automatic Detection on Twitter Cyberbullying</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Raghad%20A.%20Altowairgi">Raghad A. Altowairgi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> With the wide spread of social media platforms, young people tend to use them extensively as the first means of communication due to their ease and modernity. But these platforms often create a fertile ground for bullies to practice their aggressive behavior against their victims. Platform usage cannot be reduced, but intelligent mechanisms can be implemented to reduce the abuse. This is where machine learning comes in. Understanding and classifying text can be helpful in order to minimize the act of cyberbullying. Artificial intelligence techniques have expanded to formulate an applied tool to address the phenomenon of cyberbullying. In this research, machine learning models are built to classify text into two classes; cyberbullying and non-cyberbullying. After preprocessing the data in 4 stages; removing characters that do not provide meaningful information to the models, tokenization, removing stop words, and lowering text. BoW and TF-IDF are used as the main features for the five classifiers, which are; logistic regression, Naïve Bayes, Random Forest, XGboost, and Catboost classifiers. Each of them scores 92%, 90%, 92%, 91%, 86% respectively. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cyberbullying" title="cyberbullying">cyberbullying</a>, <a href="https://publications.waset.org/abstracts/search?q=machine%20learning" title=" machine learning"> machine learning</a>, <a href="https://publications.waset.org/abstracts/search?q=Bag-of-Words" title=" Bag-of-Words"> Bag-of-Words</a>, <a href="https://publications.waset.org/abstracts/search?q=term%20frequency-inverse%20document%20frequency" title=" term frequency-inverse document frequency"> term frequency-inverse document frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20language%20processing" title=" natural language processing"> natural language processing</a>, <a href="https://publications.waset.org/abstracts/search?q=Catboost" title=" Catboost"> Catboost</a> </p> <a href="https://publications.waset.org/abstracts/153027/machine-learning-automatic-detection-on-twitter-cyberbullying" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/153027.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">130</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9264</span> Assessment of Korea's Natural Gas Portfolio Considering Panama Canal Expansion</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Juhan%20Kim">Juhan Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Jinsoo%20Kim"> Jinsoo Kim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> South Korea cannot import natural gas in any form other than LNG because of the division of South and North Korea. Further, the high proportion of natural gas in the national energy mix makes this resource crucial for energy security in Korea. Expansion of Panama Canal will allow for reducing the cost of shipping between the Far East and U.S East. Panama Canal expansion can have significant impacts on South Korea. Due to this situation, we review the natural gas optimal portfolio by considering the uniqueness of the Korean Natural gas market and expansion of Panama Canal. In order to assess Korea’s natural gas optimal portfolio, we developed natural gas portfolio model. The model comprises two steps. First, to obtain the optimal long-term spot contract ratio, the study examines the price level and the correlation between spot and long-term contracts by using the Markowitz, portfolio model. The optimal long-term spot contract ratio follows the efficient frontier of the cost/risk level related to this price level and degree of correlation. Second, by applying the obtained long-term contract purchase ratio as the constraint in the linear programming portfolio model, we determined the natural gas optimal import portfolio that minimizes total intangible and tangible costs. Using this model, we derived the optimal natural gas portfolio considering the expansion of Panama Canal. Based on these results, we assess the portfolio for natural gas import to Korea from the perspective of energy security and present some relevant policy proposals. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=natural%20gas" title="natural gas">natural gas</a>, <a href="https://publications.waset.org/abstracts/search?q=Panama%20Canal" title=" Panama Canal"> Panama Canal</a>, <a href="https://publications.waset.org/abstracts/search?q=portfolio%20analysis" title=" portfolio analysis"> portfolio analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=South%20Korea" title=" South Korea"> South Korea</a> </p> <a href="https://publications.waset.org/abstracts/67569/assessment-of-koreas-natural-gas-portfolio-considering-panama-canal-expansion" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/67569.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">291</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9263</span> Thermal and Geometric Effects on Nonlinear Response of Incompressible Hyperelastic Cylindrical Shells</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Morteza%20Shayan%20Arani">Morteza Shayan Arani</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammadamin%20Esmailzadehazimi"> Mohammadamin Esmailzadehazimi</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammadreza%20Moeini"> Mohammadreza Moeini</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Toorani"> Mohammad Toorani</a>, <a href="https://publications.waset.org/abstracts/search?q=Aouni%20A.%20Lakis"> Aouni A. Lakis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper investigates the nonlinear response of thin, incompressible, hyperelastic cylindrical shells in the presence of a time-varying temperature field while considering initial geometric imperfections. The governing equations of motion are derived using an improved Donnell's shallow shell theory. The hyperelastic material is modeled using the Mooney-Rivlin model with two parameters, incorporating temperature-dependent terms. The Lagrangian method is applied to obtain the equation of motion. The resulting governing equation is addressed through the Lindstedt-Poincaré and Multiple Scale methods. The linear and nonlinear models presented in this study are verified against existing open literature, demonstrating the accuracy and reliability of the presented model. The study focuses on understanding the influence of temperature variations and geometrical imperfections on the natural frequency and amplitude-frequency response of the systems. Notably, the investigation reveals the coexistence of hardening and softening peaks in the amplitude-frequency response, which vary in magnitude depending on these parameters. Additionally, resonance peaks exhibit changes as a result of temperature and geometric imperfections. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hyperelastic%20material" title="hyperelastic material">hyperelastic material</a>, <a href="https://publications.waset.org/abstracts/search?q=cylindrical%20shell" title=" cylindrical shell"> cylindrical shell</a>, <a href="https://publications.waset.org/abstracts/search?q=geometrical%20nonlinearity" title=" geometrical nonlinearity"> geometrical nonlinearity</a>, <a href="https://publications.waset.org/abstracts/search?q=material%20naolinearity" title=" material naolinearity"> material naolinearity</a>, <a href="https://publications.waset.org/abstracts/search?q=initial%20geometric%20imperfection" title=" initial geometric imperfection"> initial geometric imperfection</a>, <a href="https://publications.waset.org/abstracts/search?q=temperature%20gradient" title=" temperature gradient"> temperature gradient</a>, <a href="https://publications.waset.org/abstracts/search?q=hardening%20and%20softening" title=" hardening and softening"> hardening and softening</a> </p> <a href="https://publications.waset.org/abstracts/176415/thermal-and-geometric-effects-on-nonlinear-response-of-incompressible-hyperelastic-cylindrical-shells" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/176415.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">72</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9262</span> Review of Dielectric Permittivity Measurement Techniques</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ahmad%20H.%20Abdelgwad">Ahmad H. Abdelgwad</a>, <a href="https://publications.waset.org/abstracts/search?q=Galal%20E.%20Nadim"> Galal E. Nadim</a>, <a href="https://publications.waset.org/abstracts/search?q=Tarek%20M.%20Said"> Tarek M. Said</a>, <a href="https://publications.waset.org/abstracts/search?q=Amr%20M.%20Gody"> Amr M. Gody</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The prime objective of this manuscript is to provide intensive review of the techniques used for permittivity measurements. The measurement techniques, relevant for any desired application, rely on the nature of the measured dielectric material, both electrically and physically, the degree of accuracy required, and the frequency of interest. Regardless of the way that distinctive sorts of instruments can be utilized, measuring devices that provide reliable determinations of the required electrical properties including the obscure material in the frequency range of interest can be considered. The challenge in making precise dielectric property or permittivity measurements is in designing of the material specimen holder for those measurements (RF and MW frequency ranges) and adequately modeling the circuit for reliable computation of the permittivity from the electrical measurements. If the RF circuit parameters such as the impedance or admittance are estimated appropriately at a certain frequency, the material’s permittivity at this frequency can be estimated by the equations which relate the way in which the dielectric properties of the material affect on the parameters of the circuit. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dielectric%20permittivity" title="dielectric permittivity">dielectric permittivity</a>, <a href="https://publications.waset.org/abstracts/search?q=free%20space%20measurement" title=" free space measurement"> free space measurement</a>, <a href="https://publications.waset.org/abstracts/search?q=waveguide%20techniques" title=" waveguide techniques"> waveguide techniques</a>, <a href="https://publications.waset.org/abstracts/search?q=coaxial%20probe" title=" coaxial probe"> coaxial probe</a>, <a href="https://publications.waset.org/abstracts/search?q=cavity%20resonator" title=" cavity resonator"> cavity resonator</a> </p> <a href="https://publications.waset.org/abstracts/76451/review-of-dielectric-permittivity-measurement-techniques" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76451.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">369</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9261</span> Public Health Infrastructure Resilience in the Face of Natural Disasters in Rwanda</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jessy%20Rugeyo">Jessy Rugeyo</a>, <a href="https://publications.waset.org/abstracts/search?q=William%20Donner"> William Donner</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This research delves into the resilience of Rwanda's public health infrastructure amidst natural disasters, a critical issue given that the Northern Province alone has witnessed no fewer than 1500 cases of disaster ranging from floods and landslides in the last five years, with more than 200 people killed and thousands of homes destroyed, according to MINEMA. In an era where climate change escalates the frequency and intensity of such disasters, fortifying the resilience of public health systems is paramount. This study offers a comprehensive analysis of the existing state of Rwanda's public health infrastructure and its ability to manage such crises. Employing a mix of literature review, case studies, and policy analysis, the study discerns key vulnerabilities and brings to light the intricacies of disaster management in Rwanda. Case studies centered around past natural disasters in Rwanda provide critical insights into the strengths and weaknesses of the existing disaster response mechanisms. A thorough critique of related disaster management and public health infrastructure policies reveals areas of commendable practice, along with gaps calling for policy enhancements. Findings guide the proposition of targeted strategies to bolster the resilience of Rwanda's public health infrastructure. This research serves as a significant contribution to the domains of disaster studies and public health, offering valuable insights for policymakers, public health and disaster management professionals in Rwanda and similar contexts. It presents actionable recommendations for improvement, underscoring the potential for enhancing Rwanda's disaster management capacity. By advocating for the strengthening of public health infrastructure resilience, the research highlights the potential for improved public health outcomes following natural disasters, thereby showcasing significant implications for public health and disaster management in the country, particularly in the face of a changing climate. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=public%20health%20infrastructure" title="public health infrastructure">public health infrastructure</a>, <a href="https://publications.waset.org/abstracts/search?q=disaster%20resilience" title=" disaster resilience"> disaster resilience</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20disaster" title=" natural disaster"> natural disaster</a>, <a href="https://publications.waset.org/abstracts/search?q=disaster%20management" title=" disaster management"> disaster management</a>, <a href="https://publications.waset.org/abstracts/search?q=emergency%20preparedness" title=" emergency preparedness"> emergency preparedness</a>, <a href="https://publications.waset.org/abstracts/search?q=health%20policy" title=" health policy"> health policy</a> </p> <a href="https://publications.waset.org/abstracts/168064/public-health-infrastructure-resilience-in-the-face-of-natural-disasters-in-rwanda" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/168064.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">92</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9260</span> Screening Post-Menopausal Women for Osteoporosis by Complex Impedance Measurements of the Dominant Arm</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yekta%20%C3%9Clgen">Yekta Ülgen</a>, <a href="https://publications.waset.org/abstracts/search?q=F%C4%B1rat%20Matur"> Fırat Matur</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Cole-Cole parameters of 40 post-menopausal women are compared with their DEXA bone mineral density measurements. Impedance characteristics of four extremities are compared; left and right extremities are statistically same, but lower extremities are statistically different than upper ones due to their different fat content. The correlation of Cole-Cole impedance parameters to bone mineral density (BMD) is observed to be higher for a dominant arm. With the post menopausal population, ANOVA tests of the dominant arm characteristic frequency, as a predictor for DEXA classified osteopenic and osteoporotic population around the lumbar spine, is statistically very significant. When used for total lumbar spine osteoporosis diagnosis, the area under the Receiver Operating Curve of the characteristic frequency is 0.875, suggesting that the Cole-Cole plot characteristic frequency could be a useful diagnostic parameter when integrated into standard screening methods for osteoporosis. Moreover, the characteristic frequency can be directly measured by monitoring frequency driven the angular behavior of the dominant arm without performing any complex calculation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bioimpedance%20spectroscopy" title="bioimpedance spectroscopy">bioimpedance spectroscopy</a>, <a href="https://publications.waset.org/abstracts/search?q=bone%20mineral%20density" title=" bone mineral density"> bone mineral density</a>, <a href="https://publications.waset.org/abstracts/search?q=osteoporosis" title=" osteoporosis"> osteoporosis</a>, <a href="https://publications.waset.org/abstracts/search?q=characteristic%20frequency" title=" characteristic frequency"> characteristic frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=receiver%20operating%20curve" title=" receiver operating curve"> receiver operating curve</a> </p> <a href="https://publications.waset.org/abstracts/30804/screening-post-menopausal-women-for-osteoporosis-by-complex-impedance-measurements-of-the-dominant-arm" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/30804.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">522</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9259</span> Design of Wireless Readout System for Resonant Gas Sensors</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Mohamed%20Rabeek">S. Mohamed Rabeek</a>, <a href="https://publications.waset.org/abstracts/search?q=Mi%20Kyoung%20Park"> Mi Kyoung Park</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Annamalai%20Arasu"> M. Annamalai Arasu </a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents a design of a wireless read out system for tracking the frequency shift of the polymer coated piezoelectric micro electromechanical resonator due to gas absorption. The measure of this frequency shift indicates the percentage of a particular gas the sensor is exposed to. It is measured using an oscillator and an FPGA based frequency counter by employing the resonator as a frequency determining element in the oscillator. This system consists of a Gas Sensing Wireless Readout (GSWR) and an USB Wireless Transceiver (UWT). GSWR consists of an oscillator based on a trans-impedance sustaining amplifier, an FPGA based frequency readout, a sub 1GHz wireless transceiver and a micro controller. UWT can be plugged into the computer via USB port and function as a wireless module to transfer gas sensor data from GSWR to the computer through its USB port. GUI program running on the computer periodically polls for sensor data through UWT - GSWR wireless link, the response from GSWR is logged in a file for post processing as well as displayed on screen. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=gas%20sensor" title="gas sensor">gas sensor</a>, <a href="https://publications.waset.org/abstracts/search?q=GSWR" title=" GSWR"> GSWR</a>, <a href="https://publications.waset.org/abstracts/search?q=micromechanical%20system" title=" micromechanical system"> micromechanical system</a>, <a href="https://publications.waset.org/abstracts/search?q=UWT" title=" UWT"> UWT</a>, <a href="https://publications.waset.org/abstracts/search?q=volatile%20emissions" title=" volatile emissions"> volatile emissions</a> </p> <a href="https://publications.waset.org/abstracts/35201/design-of-wireless-readout-system-for-resonant-gas-sensors" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35201.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">483</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9258</span> Finite Element Model to Investigate the Dynamic Behavior of Ring-Stiffened Conical Shell Fully and Partially Filled with Fluid</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohammadamin%20Esmaeilzadehazimi">Mohammadamin Esmaeilzadehazimi</a>, <a href="https://publications.waset.org/abstracts/search?q=Morteza%20Shayan%20Arani"> Morteza Shayan Arani</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Toorani"> Mohammad Toorani</a>, <a href="https://publications.waset.org/abstracts/search?q=Aouni%20Lakis"> Aouni Lakis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study uses a hybrid finite element method to predict the dynamic behavior of both fully and partially-filled truncated conical shells stiffened with ring stiffeners. The method combines classical shell theory and the finite element method, and employs displacement functions derived from exact solutions of Sanders' shell equilibrium equations for conical shells. The shell-fluid interface is analyzed by utilizing the velocity potential, Bernoulli's equation, and impermeability conditions to determine an explicit expression for fluid pressure. The equations of motion presented in this study apply to both conical and cylindrical shells. This study presents the first comparison of the method applied to ring-stiffened shells with other numerical and experimental findings. Vibration frequencies for conical shells with various boundary conditions and geometries in a vacuum and filled with water are compared with experimental and numerical investigations, achieving good agreement. The study thoroughly investigates the influence of geometric parameters, stiffener quantity, semi-vertex cone angle, level of water filled in the cone, and applied boundary conditions on the natural frequency of fluid-loaded ring-stiffened conical shells, and draws some useful conclusions. The primary advantage of the current method is its use of a minimal number of finite elements while achieving highly accurate results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20method" title="finite element method">finite element method</a>, <a href="https://publications.waset.org/abstracts/search?q=fluid%E2%80%93structure%20interaction" title=" fluid–structure interaction"> fluid–structure interaction</a>, <a href="https://publications.waset.org/abstracts/search?q=conical%20shell" title=" conical shell"> conical shell</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency" title=" natural frequency"> natural frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=ring-stiffener" title=" ring-stiffener"> ring-stiffener</a> </p> <a href="https://publications.waset.org/abstracts/177559/finite-element-model-to-investigate-the-dynamic-behavior-of-ring-stiffened-conical-shell-fully-and-partially-filled-with-fluid" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/177559.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">78</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9257</span> Free Vibration of Axially Functionally Graded Simply Supported Beams Using Differential Transformation Method </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A.%20Selmi">A. Selmi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Free vibration analysis of homogenous and axially functionally graded simply supported beams within the context of Euler-Bernoulli beam theory is presented in this paper. The material properties of the beams are assumed to obey the linear law distribution. The effective elastic modulus of the composite was predicted by using the rule of mixture. Here, the complexities which appear in solving differential equation of transverse vibration of composite beams which limit the analytical solution to some special cases are overcome using a relatively new approach called the Differential Transformation Method. This technique is applied for solving differential equation of transverse vibration of axially functionally graded beams. Natural frequencies and corresponding normalized mode shapes are calculated for different Young’s modulus ratios. MATLAB code is designed to solve the transformed differential equation of the beam. Comparison of the present results with the exact solutions proves the effectiveness, the accuracy, the simplicity, and computational stability of the differential transformation method. The effect of the Young’s modulus ratio on the normalized natural frequencies and mode shapes is found to be very important. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=differential%20transformation%20method" title="differential transformation method">differential transformation method</a>, <a href="https://publications.waset.org/abstracts/search?q=functionally%20graded%20material" title=" functionally graded material"> functionally graded material</a>, <a href="https://publications.waset.org/abstracts/search?q=mode%20shape" title=" mode shape"> mode shape</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency" title=" natural frequency"> natural frequency</a> </p> <a href="https://publications.waset.org/abstracts/95420/free-vibration-of-axially-functionally-graded-simply-supported-beams-using-differential-transformation-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/95420.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">309</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9256</span> Using the GIS Technology for Erosion Risk Mapping of BEN EL WIDAN Dam Watershed in Beni Mallal, Marroco</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Azzouzi%20Fadoua">Azzouzi Fadoua</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study focuses on the diagnosis of the dynamics of natural resources in a semi-arid mountainous weakened by natural vulnerability and anthropogenic action. This is evident in the forms of hydraulic erosion and degradation of agricultural land. The rate of this damaged land is 53%, with a strong presence of concentrated erosion; this shows that balanced and semi-balanced environments are less apparent to the Watershed, representing 47%. The results revealed the crucial role of the slopes and the density of the hydraulic networks to facilitate the transport of fine elements, at the level of the slopes with low vegetation intensity, to the lake of the dam. Something that endangers the siltation of the latter. After the study of natural and anthropogenic elements, it turned out that natural vulnerability is an integral part of the current dynamic, especially when it coincides with the overexploitation of natural resources, in this case, the exploitation of steep slopes for the cultivation of cereals and overgrazing. This causes the soil to pile up and increase the rate of runoff. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=watershed" title="watershed">watershed</a>, <a href="https://publications.waset.org/abstracts/search?q=erosion" title=" erosion"> erosion</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20vulnerability" title=" natural vulnerability"> natural vulnerability</a>, <a href="https://publications.waset.org/abstracts/search?q=anthropogenic" title=" anthropogenic"> anthropogenic</a> </p> <a href="https://publications.waset.org/abstracts/156316/using-the-gis-technology-for-erosion-risk-mapping-of-ben-el-widan-dam-watershed-in-beni-mallal-marroco" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/156316.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">151</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9255</span> Role of Natural Language Processing in Information Retrieval; Challenges and Opportunities </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khaled%20M.%20Alhawiti">Khaled M. Alhawiti</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper aims to analyze the role of natural language processing (NLP). The paper will discuss the role in the context of automated data retrieval, automated question answer, and text structuring. NLP techniques are gaining wider acceptance in real life applications and industrial concerns. There are various complexities involved in processing the text of natural language that could satisfy the need of decision makers. This paper begins with the description of the qualities of NLP practices. The paper then focuses on the challenges in natural language processing. The paper also discusses major techniques of NLP. The last section describes opportunities and challenges for future research. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=data%20retrieval" title="data retrieval">data retrieval</a>, <a href="https://publications.waset.org/abstracts/search?q=information%20retrieval" title=" information retrieval"> information retrieval</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20language%20processing" title=" natural language processing"> natural language processing</a>, <a href="https://publications.waset.org/abstracts/search?q=text%20structuring" title=" text structuring"> text structuring</a> </p> <a href="https://publications.waset.org/abstracts/21284/role-of-natural-language-processing-in-information-retrieval-challenges-and-opportunities" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21284.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">340</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9254</span> Low Complexity Deblocking Algorithm</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jagroop%20Singh%20Sidhu">Jagroop Singh Sidhu</a>, <a href="https://publications.waset.org/abstracts/search?q=Buta%20Singh"> Buta Singh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A low computational deblocking filter including three frequency related modes (smooth mode, intermediate mode, and non-smooth mode for low-frequency, mid-frequency, and high frequency regions, respectively) is proposed. The suggested approach requires zero additions, zero subtractions, zero multiplications (for intermediate region), no divisions (for non-smooth region) and no comparison. The suggested method thus keeps the computation lower and thus suitable for image coding systems based on blocks. Comparison of average number of operations for smooth, non-smooth, intermediate (per pixel vector for each block) using filter suggested by Chen and the proposed method filter suggests that the proposed filter keeps the computation lower and is thus suitable for fast processing algorithms. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=blocking%20artifacts" title="blocking artifacts">blocking artifacts</a>, <a href="https://publications.waset.org/abstracts/search?q=computational%20complexity" title=" computational complexity"> computational complexity</a>, <a href="https://publications.waset.org/abstracts/search?q=non-smooth" title=" non-smooth"> non-smooth</a>, <a href="https://publications.waset.org/abstracts/search?q=intermediate" title=" intermediate"> intermediate</a>, <a href="https://publications.waset.org/abstracts/search?q=smooth" title=" smooth"> smooth</a> </p> <a href="https://publications.waset.org/abstracts/47157/low-complexity-deblocking-algorithm" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/47157.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">462</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9253</span> Study on Roll Marks of Stainless Steel in Rolling Mill</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Cai-Wan%20Chang-Jian">Cai-Wan Chang-Jian</a>, <a href="https://publications.waset.org/abstracts/search?q=Han-Ting%20Tsai"> Han-Ting Tsai</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the processing industry of metal forming, rolling is the most used method of processing. In a cold rolling factory of stainless steel, there occurs a product defect on temper rolling process within cold rolling. It is called 'roll marks', which is a phenomenon of undesirable flatness problem. In this research, we performed a series of experimental measurements on the roll marks, and we used optical sensors to measure it and compared the vibration frequency of roll marks with the vibration frequency of key components in the skin pass mill. We found there is less correlation between the above mentioned data. Finally, we took measurement on the motor driver in rolling mill. We found that the undulation frequency of motor could match with the frequency of roll marks, and then we have confirmed that the motor’s undulation caused roll marks. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=roll%20mark" title="roll mark">roll mark</a>, <a href="https://publications.waset.org/abstracts/search?q=plane%20strain" title=" plane strain"> plane strain</a>, <a href="https://publications.waset.org/abstracts/search?q=rolling%20mill" title=" rolling mill"> rolling mill</a>, <a href="https://publications.waset.org/abstracts/search?q=stainless%20steel" title=" stainless steel"> stainless steel</a> </p> <a href="https://publications.waset.org/abstracts/7174/study-on-roll-marks-of-stainless-steel-in-rolling-mill" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7174.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">454</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9252</span> A Micro-Scale of Electromechanical System Micro-Sensor Resonator Based on UNO-Microcontroller for Low Magnetic Field Detection</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Waddah%20Abdelbagi%20Talha">Waddah Abdelbagi Talha</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammed%20Abdullah%20Elmaleeh"> Mohammed Abdullah Elmaleeh</a>, <a href="https://publications.waset.org/abstracts/search?q=John%20Ojur%20Dennis"> John Ojur Dennis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper focuses on the simulation and implementation of a resonator micro-sensor for low magnetic field sensing based on a U-shaped cantilever and piezoresistive configuration, which works based on Lorentz force physical phenomena. The resonance frequency is an important parameter that depends upon the highest response and sensitivity through the frequency domain (frequency response) of any vibrated micro-scale of an electromechanical system (MEMS) device. And it is important to determine the direction of the detected magnetic field. The deflection of the cantilever is considered for vibrated mode with different frequencies in the range of (0 Hz to 7000 Hz); for the purpose of observing the frequency response. A simple electronic circuit-based polysilicon piezoresistors in Wheatstone's bridge configuration are used to transduce the response of the cantilever to electrical measurements at various voltages. Microcontroller-based Arduino program and PROTEUS electronic software are used to analyze the output signals from the sensor. The highest output voltage amplitude of about 4.7 mV is spotted at about 3 kHz of the frequency domain, indicating the highest sensitivity, which can be called resonant sensitivity. Based on the resonant frequency value, the mode of vibration is determined (up-down vibration), and based on that, the vector of the magnetic field is also determined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=resonant%20frequency" title="resonant frequency">resonant frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=sensitivity" title=" sensitivity"> sensitivity</a>, <a href="https://publications.waset.org/abstracts/search?q=Wheatstone%20bridge" title=" Wheatstone bridge"> Wheatstone bridge</a>, <a href="https://publications.waset.org/abstracts/search?q=UNO-microcontroller" title=" UNO-microcontroller"> UNO-microcontroller</a> </p> <a href="https://publications.waset.org/abstracts/152891/a-micro-scale-of-electromechanical-system-micro-sensor-resonator-based-on-uno-microcontroller-for-low-magnetic-field-detection" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/152891.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">127</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9251</span> Comparative Study of Free Vibrational Analysis and Modes Shapes of FSAE Car Frame Using Different FEM Modules</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rajat%20Jain">Rajat Jain</a>, <a href="https://publications.waset.org/abstracts/search?q=Himanshu%20Pandey"> Himanshu Pandey</a>, <a href="https://publications.waset.org/abstracts/search?q=Somesh%20Mehta"> Somesh Mehta</a>, <a href="https://publications.waset.org/abstracts/search?q=Pravin%20P.%20Patil"> Pravin P. Patil</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Formula SAE cars are the student designed and fabricated formula prototype cars, designed according to SAE INTERNATIONAL design rules which compete in the various national and international events. This paper shows a FEM based comparative study of free vibration analysis of different mode shapes of a formula prototype car chassis frame. Tubing sections of different diameters as per the design rules are designed in such a manner that the desired strength can be achieved. Natural frequency of first five mode was determined using finite element analysis method. SOLIDWORKS is used for designing the frame structure and SOLIDWORKS SIMULATION and ANSYS WORKBENCH 16.2 are used for the modal analysis. Mode shape results of ANSYS and SOLIDWORKS were compared. Fixed –fixed boundary conditions are used for fixing the A-arm wishbones. The simulation results were compared for the validation of the study. First five modes were compared and results were found within the permissible limits. The AISI4130 (CROMOLY- chromium molybdenum steel) material is used and the chassis frame is discretized with fine quality QUAD mesh followed by Fixed-fixed boundary conditions. The natural frequency of the chassis frame is 53.92-125.5 Hz as per the results of ANSYS which is found within the permissible limits. The study is concluded with the light weight and compact chassis frame without compensation with strength. This design allows to fabricate an extremely safe driver ergonomics, compact, dynamically stable, simple and light weight tubular chassis frame with higher strength. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=FEM" title="FEM">FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=formula%20SAE%20cars" title=" formula SAE cars"> formula SAE cars</a>, <a href="https://publications.waset.org/abstracts/search?q=chassis%20frame" title=" chassis frame"> chassis frame</a>, <a href="https://publications.waset.org/abstracts/search?q=Ansys" title=" Ansys"> Ansys</a> </p> <a href="https://publications.waset.org/abstracts/51672/comparative-study-of-free-vibrational-analysis-and-modes-shapes-of-fsae-car-frame-using-different-fem-modules" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/51672.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">347</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9250</span> Hanna Arendt and Al-Farabi’s Non-Naturalistic Political Philosophy</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Hossein%20Badamchi">Mohammad Hossein Badamchi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> As Leo Strauss demonstrates in his works, Political Philosophy in the western tradition is an epistemic-naturalistic tradition insofar Hanna Arendt mentioning the deep conflict between philosophy and politics, opposed to be named “political philosopher” prefer the title “political thinker” for herself. In fact, the Western political philosophy’s tendency to derive politics from natural law and epistemic argumentations makes a paradox between the actual “the political” and the theoretical “natural politics” in the western tradition. In this paper, we want to show that Hanna Arendt, in her exploration to find a new realm of the non-naturalistic way of thinking about the political is walking on a completely different tradition of political philosophy which was first established by Al-Farabi, the founder of Islamic political philosophy around thousand years after Greek Philosophy. Despite Aristotelian Polis which is a Natural community based on true natural rationality to reach the natural purposes of mankind, Al-Farabi’s Madine (his reconstructed concept of Aristotelian Polis) is completely constructed against natural cities, which are formulated by necessity logic of natural arguments and natural deception of humanity. In fact, Farabi considers the natural understanding of politics as Ignorant ideologies used by governments to suppress people. Madine in Farabi’s work is not a natural institution but is a collaborative constitution founded by citizens. So despite Aristotelian thinking, here we don’t have just A Polis that is the one true polis, but we have various multiple Madines among one, is virtuous not by definition but by real action of citizens and civil relations. Al-Farabi’s political philosophy is not a Naturalistic-epistemic Political Philosophy but is a Phronetic Political Philosophy which Hanna Arendt wants to establish outside of western contemplative anti-active political philosophy tradition. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=al-farabi" title="al-farabi">al-farabi</a>, <a href="https://publications.waset.org/abstracts/search?q=hanna%20arendt" title=" hanna arendt"> hanna arendt</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20politics" title=" natural politics"> natural politics</a>, <a href="https://publications.waset.org/abstracts/search?q=the%20political" title=" the political"> the political</a>, <a href="https://publications.waset.org/abstracts/search?q=political%20philosophy" title=" political philosophy"> political philosophy</a> </p> <a href="https://publications.waset.org/abstracts/141173/hanna-arendt-and-al-farabis-non-naturalistic-political-philosophy" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/141173.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">295</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9249</span> A High Time Resolution Digital Pulse Width Modulator Based on Field Programmable Gate Array’s Phase Locked Loop Megafunction</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jun%20Wang">Jun Wang</a>, <a href="https://publications.waset.org/abstracts/search?q=Tingcun%20Wei"> Tingcun Wei</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The digital pulse width modulator (DPWM) is the crucial building block for digitally-controlled DC-DC switching converter, which converts the digital duty ratio signal into its analog counterpart to control the power MOSFET transistors on or off. With the increase of switching frequency of digitally-controlled DC-DC converter, the DPWM with higher time resolution is required. In this paper, a 15-bits DPWM with three-level hybrid structure is presented; the first level is composed of a7-bits counter and a comparator, the second one is a 5-bits delay line, and the third one is a 3-bits digital dither. The presented DPWM is designed and implemented using the PLL megafunction of FPGA (Field Programmable Gate Arrays), and the required frequency of clock signal is 128 times of switching frequency. The simulation results show that, for the switching frequency of 2 MHz, a DPWM which has the time resolution of 15 ps is achieved using a maximum clock frequency of 256MHz. The designed DPWM in this paper is especially useful for high-frequency digitally-controlled DC-DC switching converters. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DPWM" title="DPWM">DPWM</a>, <a href="https://publications.waset.org/abstracts/search?q=digitally-controlled%20DC-DC%20switching%20converter" title=" digitally-controlled DC-DC switching converter"> digitally-controlled DC-DC switching converter</a>, <a href="https://publications.waset.org/abstracts/search?q=FPGA" title=" FPGA"> FPGA</a>, <a href="https://publications.waset.org/abstracts/search?q=PLL%20megafunction" title=" PLL megafunction"> PLL megafunction</a>, <a href="https://publications.waset.org/abstracts/search?q=time%20resolution" title=" time resolution"> time resolution</a> </p> <a href="https://publications.waset.org/abstracts/50826/a-high-time-resolution-digital-pulse-width-modulator-based-on-field-programmable-gate-arrays-phase-locked-loop-megafunction" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/50826.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">480</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9248</span> Historic Fire Occurrence in Hemi-Boreal Forests: Exploring Natural and Cultural Scots Pine Multi-Cohort Fire Regimes in Lithuania</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Charles%20Ruffner">Charles Ruffner</a>, <a href="https://publications.waset.org/abstracts/search?q=Michael%20Manton"> Michael Manton</a>, <a href="https://publications.waset.org/abstracts/search?q=Gintautas%20Kibirkstis"> Gintautas Kibirkstis</a>, <a href="https://publications.waset.org/abstracts/search?q=Gediminas%20Brazaitas"> Gediminas Brazaitas</a>, <a href="https://publications.waset.org/abstracts/search?q=Vitas%20Marozas"> Vitas Marozas</a>, <a href="https://publications.waset.org/abstracts/search?q=Ekaterine%20Makrickiene"> Ekaterine Makrickiene</a>, <a href="https://publications.waset.org/abstracts/search?q=Rutile%20Pukiene"> Rutile Pukiene</a>, <a href="https://publications.waset.org/abstracts/search?q=Per%20Angelstam"> Per Angelstam</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In dynamic boreal forests, fire is an important natural disturbance, which drives regeneration and mortality of living and dead trees, and thus successional trajectories. However, current forest management practices focusing on wood production only have effectively eliminated fire as a stand-level disturbance. While this is generally well studied across much of Europe, in Lithuania, little is known about the historic fire regime and the role fire plays as a management tool towards the sustainable management of future landscapes. Focusing on Scots pine forests, we explore; i) the relevance of fire disturbance regimes on forestlands of Lithuania; ii) fire occurrence in the Dzukija landscape for dry upland and peatland forest sites, and iii) correlate tree-ring data with climate variables to ascertain climatic influences on growth and fire occurrence. We sampled and cross-dated 132 Scots pine samples with fire scars from 4 dry pine forest stands and 4 peatland forest stands, respectively. The fire history of each sample was analyzed using standard dendrochronological methods and presented in FHAES format. Analyses of soil moisture and nutrient conditions revealed a strong probability of finding forests that have a high fire frequency in Scots pine forests (59%), which cover 34.5% of Lithuania’s current forestland. The fire history analysis revealed 455 fire scars and 213 fire events during the period 1742-2019. Within the Dzukija landscape, the mean fire interval was 4.3 years for the dry Scots pine forest and 8.7 years for the peatland Scots pine forest. However, our comparison of fire frequency before and after 1950 shows a marked decrease in mean fire interval. Our data suggest that hemi-boreal forest landscapes of Lithuania provide strong evidence that fire, both human and lightning-ignited fires, has been and should be a natural phenomenon and that the examination of biological archives can be used to guide sustainable forest management into the future. Currently, fire use is prohibited by law as a tool for forest management in Lithuania. We recommend introducing trials that use low-intensity prescribed burning of Scots pine stands as a regeneration tool towards mimicking natural forest disturbance regimes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=biodiversity%20conservation" title="biodiversity conservation">biodiversity conservation</a>, <a href="https://publications.waset.org/abstracts/search?q=cultural%20burning" title=" cultural burning"> cultural burning</a>, <a href="https://publications.waset.org/abstracts/search?q=dendrochronology" title=" dendrochronology"> dendrochronology</a>, <a href="https://publications.waset.org/abstracts/search?q=forest%20dynamics" title=" forest dynamics"> forest dynamics</a>, <a href="https://publications.waset.org/abstracts/search?q=forest%20management" title=" forest management"> forest management</a>, <a href="https://publications.waset.org/abstracts/search?q=succession" title=" succession"> succession</a> </p> <a href="https://publications.waset.org/abstracts/138982/historic-fire-occurrence-in-hemi-boreal-forests-exploring-natural-and-cultural-scots-pine-multi-cohort-fire-regimes-in-lithuania" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/138982.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">200</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9247</span> Positive Effects of Natural Gas Usage on Air Pollution</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ismail%20Becenen">Ismail Becenen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Air pollution, a consequence of urbanization brought about by modern life, is as global as it is local and regional. Because of the adverse effects of air pollution on human health, air quality is given importance all over the world. According to the decision of the World Health Organization, clean air is the basic necessity for human health and well-being. It poses a very high risk especially for heart diseases and stroke cases. In this study, the positive effects of natural gas usage on air pollution in cities are explained by using literature scans and air pollution measurement values. Natural gas is cleaner than other types of fuel. It contains less sulfur and organic sulfur compounds. When natural gas burns, it does not leave ashes, it does not cause problems in the rubbish mountains. It's a clean fuel, it easily burns and shines. It is a burning gas that is easy and efficient. In addition, there is not a toxic effect for people in case of inhalation. As a result, the use of natural gas needs to be widespread to reduce air pollution around the world in order to provide a healthier life for people and the environment. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=natural%20gas" title="natural gas">natural gas</a>, <a href="https://publications.waset.org/abstracts/search?q=air%20pollution" title=" air pollution"> air pollution</a>, <a href="https://publications.waset.org/abstracts/search?q=sulfur%20dioxide" title=" sulfur dioxide"> sulfur dioxide</a>, <a href="https://publications.waset.org/abstracts/search?q=particulate%20matter" title=" particulate matter"> particulate matter</a>, <a href="https://publications.waset.org/abstracts/search?q=energy" title=" energy"> energy</a> </p> <a href="https://publications.waset.org/abstracts/83426/positive-effects-of-natural-gas-usage-on-air-pollution" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/83426.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">196</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9246</span> Frequency Modulation in Vibro-Acoustic Modulation Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=D.%20Liu">D. Liu</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20M.%20Donskoy"> D. M. Donskoy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The vibroacoustic modulation method is based on the modulation effect of high-frequency ultrasonic wave (carrier) by low-frequency vibration in the presence of various defects, primarily contact-type such as cracks, delamination, etc. The presence and severity of the defect are measured by the ratio of the spectral sidebands and the carrier in the spectrum of the modulated signal. This approach, however, does not differentiate between amplitude and frequency modulations, AM and FM, respectfully. It was experimentally shown that both modulations could be present in the spectrum, yet each modulation may be associated with different physical mechanisms. AM mechanisms are quite well understood and widely covered in the literature. This paper is a first attempt to explain the generation mechanisms of FM and its correlation with the flaw properties. Here we proposed two possible mechanisms leading to FM modulation based on nonlinear local defect resonance and dynamic acousto-elastic models. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=non-destructive%20testing" title="non-destructive testing">non-destructive testing</a>, <a href="https://publications.waset.org/abstracts/search?q=nonlinear%20acoustics" title=" nonlinear acoustics"> nonlinear acoustics</a>, <a href="https://publications.waset.org/abstracts/search?q=structural%20health%20monitoring" title=" structural health monitoring"> structural health monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=acousto-elasticity" title=" acousto-elasticity"> acousto-elasticity</a>, <a href="https://publications.waset.org/abstracts/search?q=local%20defect%20resonance" title=" local defect resonance"> local defect resonance</a> </p> <a href="https://publications.waset.org/abstracts/149507/frequency-modulation-in-vibro-acoustic-modulation-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/149507.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">152</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9245</span> Variations in the Frequency-Magnitude Distribution with Depth in Kalabsha Area, Aswan, South Egypt</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ezzat%20Mohamed%20El-Amin">Ezzat Mohamed El-Amin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Mapping the earthquake-size distribution in various tectonic regimes on a local to regional scale reveals statistically significant variations in the range of at least 0.4 to 2.0 for the b-value in the frequency-magnitude distribution. We map the earthquake frequency–magnitude distribution (b value) as a function of depth in the Reservoir Triggered Seismicity (RTS) region in Kalabsha region, in south Egypt. About 1680 well-located events recorded during 1981–2014 in the Kalabsha region are selected for the analysis. The earthquake data sets are separated in 5 km zones from 0 to 25 km depth. The result shows a systematic decrease in b value up to 12 km followed by an increase. The increase in b value is interpreted to be caused by the presence of ﬂuids. We also investigate the spatial distribution of b value with depth. Signiﬁcant variations in the b value are detected, with b ranging from b 0.7 to 1.19. Low b value areas at 5 km depth indicate localized high stresses which are favorable for future rupture. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=seismicity" title="seismicity">seismicity</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency-magnitude" title=" frequency-magnitude"> frequency-magnitude</a>, <a href="https://publications.waset.org/abstracts/search?q=b-value" title=" b-value"> b-value</a>, <a href="https://publications.waset.org/abstracts/search?q=earthquake" title=" earthquake"> earthquake</a> </p> <a href="https://publications.waset.org/abstracts/35965/variations-in-the-frequency-magnitude-distribution-with-depth-in-kalabsha-area-aswan-south-egypt" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35965.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">556</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9244</span> Absorption of Ultrashort Electromagnetic Pulses on Gold Nanospheres in Various Dielectric Media</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sergey%20Svita">Sergey Svita</a>, <a href="https://publications.waset.org/abstracts/search?q=Valeriy%20Astapenko"> Valeriy Astapenko</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The study is devoted to theoretical analysis of ultrashort electromagnetic pulses (USP) absorption on gold nanospheres. Dependencies of USP energy absorption on nanospheres placed in various matrix are compared. The results of calculation of absorbed energy on gold nanospheres as a function of ultrashort electromagnetic pulse carrier frequency and number of pulse cycles of carrier frequency show strong non-linear dependence of absorbed energy on number of cycles of carrier frequency, but for relatively large number of cycles on USP carrier frequency it goes to linear dependence. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ultrashort%20electromagnetic%20pulses" title="ultrashort electromagnetic pulses">ultrashort electromagnetic pulses</a>, <a href="https://publications.waset.org/abstracts/search?q=absorption" title=" absorption"> absorption</a>, <a href="https://publications.waset.org/abstracts/search?q=nanospheres" title=" nanospheres"> nanospheres</a>, <a href="https://publications.waset.org/abstracts/search?q=theoretical%20research" title=" theoretical research"> theoretical research</a> </p> <a href="https://publications.waset.org/abstracts/53141/absorption-of-ultrashort-electromagnetic-pulses-on-gold-nanospheres-in-various-dielectric-media" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/53141.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">256</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9243</span> Bit Error Rate Analysis of Multiband OFCDM UWB System in UWB Fading Channel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sanjay%20M.%20Gulhane">Sanjay M. Gulhane</a>, <a href="https://publications.waset.org/abstracts/search?q=Athar%20Ravish%20Khan"> Athar Ravish Khan</a>, <a href="https://publications.waset.org/abstracts/search?q=Umesh%20W.%20Kaware"> Umesh W. Kaware</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Orthogonal frequency and code division multiplexing (OFCDM) has received large attention as a modulation scheme to realize high data rate transmission. Multiband (MB) Orthogonal frequency division multiplexing (OFDM) Ultra Wide Band (UWB) system become promising technique for high data rate due to its large number of advantage over Singleband (UWB) system, but it suffer from coherent frequency diversity problem. In this paper we have proposed MB-OFCDM UWB system, in which two-dimensional (2D) spreading (time and frequency domain spreading), has been introduced, combining OFDM with 2D spreading, proposed system can provide frequency diversity. This paper presents the basic structure and main functions of the MB-OFCDM system, and evaluates the bit error rate BER performance of MB-OFDM and MB-OFCDM system under UWB indoor multi-path channel model. It is observe that BER curve of MB-OFCDM UWB improve its performance by 2dB as compare to MB-OFDM UWB system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=MB-OFDM%20UWB%20system" title="MB-OFDM UWB system">MB-OFDM UWB system</a>, <a href="https://publications.waset.org/abstracts/search?q=MB-OFCDM%20UWB%20system" title=" MB-OFCDM UWB system"> MB-OFCDM UWB system</a>, <a href="https://publications.waset.org/abstracts/search?q=UWB%20IEEE%20channel%20model" title=" UWB IEEE channel model"> UWB IEEE channel model</a>, <a href="https://publications.waset.org/abstracts/search?q=BER" title=" BER"> BER</a> </p> <a href="https://publications.waset.org/abstracts/3112/bit-error-rate-analysis-of-multiband-ofcdm-uwb-system-in-uwb-fading-channel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/3112.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">549</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9242</span> When Change Is the Only Constant: The Impact of Change Frequency and Diversity on Change Appraisal</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Danika%20Pieters">Danika Pieters</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Due to changing societal and economic demands, organizational change has become increasingly prevalent in work life. While a long time change research has focused on the effects of single discrete change events on different employee outcomes such as job satisfaction and organizational commitment, a nascent research stream has begun to look into the potential cumulative effects of change in the context of continuous intense reforms. This case study of a large Belgian public organization aims to add to this growing literature by examining how the frequency and diversity of past changes impact employees’ appraisals of a newly introduced change. Twelve hundred survey results were analyzed using standard ordinary least squares regression. Results showed a correlation between high past change frequency and diversity and a negative appraisal of the new change. Implications for practitioners and future research are discussed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=change%20frequency" title="change frequency">change frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=change%20diversity" title=" change diversity"> change diversity</a>, <a href="https://publications.waset.org/abstracts/search?q=organizational%20changes" title=" organizational changes"> organizational changes</a>, <a href="https://publications.waset.org/abstracts/search?q=change%20appraisal" title=" change appraisal"> change appraisal</a>, <a href="https://publications.waset.org/abstracts/search?q=change%20evaluation" title=" change evaluation"> change evaluation</a> </p> <a href="https://publications.waset.org/abstracts/147976/when-change-is-the-only-constant-the-impact-of-change-frequency-and-diversity-on-change-appraisal" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/147976.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">135</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9241</span> Frequency Offset Estimation Schemes Based on ML for OFDM Systems in Non-Gaussian Noise Environments</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Keunhong%20Chae">Keunhong Chae</a>, <a href="https://publications.waset.org/abstracts/search?q=Seokho%20Yoon"> Seokho Yoon</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, frequency offset (FO) estimation schemes robust to the non-Gaussian noise environments are proposed for orthogonal frequency division multiplexing (OFDM) systems. First, a maximum-likelihood (ML) estimation scheme in non-Gaussian noise environments is proposed, and then, the complexity of the ML estimation scheme is reduced by employing a reduced set of candidate values. In numerical results, it is demonstrated that the proposed schemes provide a significant performance improvement over the conventional estimation scheme in non-Gaussian noise environments while maintaining the performance similar to the estimation performance in Gaussian noise environments. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=frequency%20offset%20estimation" title="frequency offset estimation">frequency offset estimation</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum-likelihood" title=" maximum-likelihood"> maximum-likelihood</a>, <a href="https://publications.waset.org/abstracts/search?q=non-Gaussian%20noise%0D%0Aenvironment" title=" non-Gaussian noise environment"> non-Gaussian noise environment</a>, <a href="https://publications.waset.org/abstracts/search?q=OFDM" title=" OFDM"> OFDM</a>, <a href="https://publications.waset.org/abstracts/search?q=training%20symbol" title=" training symbol"> training symbol</a> </p> <a href="https://publications.waset.org/abstracts/9430/frequency-offset-estimation-schemes-based-on-ml-for-ofdm-systems-in-non-gaussian-noise-environments" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/9430.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">353</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9240</span> Synthesis of Iso-Amyl, Benzyl and Cinnamyl Esters over Active, Selective, Reusable and Eco-Friendly Natural Silica Catalyst</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abd%20El-Aziz%20Said">Abd El-Aziz Said</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, natural silica was used as an active, selective, reusable and eco-friendly catalyst for the liquid phase synthesis of iso-amyl, benzyl and cinnamyl esters. The original and calcined natural silica were characterized by TG-DTA, XRF, XRD, FTIR, SEM, and N2-sorption analysis. The surface acidity of the catalysts was determined using isopropanol dehydration and the strength of available acid sites was measured using chemisorption of pyridine (PY) and dimethyl pyridine (DMPY). The results of acidity specified that the acidic sites are of Brönsted type, while PY-TPD demonstrated that almost of the acidic sites over the surface of natural silica are of weak and intermediate strength. The catalytic activity of natural silica towards esterification of acetic acid with alcohols was extensively studied. The results revealed that natural silica had high catalytic activity with 100% selectivity to all targeted esters. In addition, the yields obtained in batch methods were 83, 81, and 80%, respectively, whereas these yields after simple distillation were improved 97, 99.5, and 90%, respectively. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=liquid-phase%20esterification" title="liquid-phase esterification">liquid-phase esterification</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20silica" title=" natural silica"> natural silica</a>, <a href="https://publications.waset.org/abstracts/search?q=acidity%20esters" title=" acidity esters"> acidity esters</a>, <a href="https://publications.waset.org/abstracts/search?q=characterization" title=" characterization"> characterization</a> </p> <a href="https://publications.waset.org/abstracts/120099/synthesis-of-iso-amyl-benzyl-and-cinnamyl-esters-over-active-selective-reusable-and-eco-friendly-natural-silica-catalyst" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/120099.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">133</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9239</span> Investigation on the Fire Resistance of Ultra-High Performance Concrete with Natural Fibers</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dong%20Zhang">Dong Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Kang%20Hai%20Tan"> Kang Hai Tan</a>, <a href="https://publications.waset.org/abstracts/search?q=Aravind%20Dasari"> Aravind Dasari</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Increasing concern on environmental sustainability and waste management has driven the construction and building sector towards renewable materials. In this work, we have explored the usage of natural fibers as an alternative to synthetic fibers like polypropylene (PP) in ultra-high performance concrete (UHPC). PP fibers are incorporated into concrete to resist explosive thermal spalling of UHPC during a fire exposure scenario. Experimental studies on the effect of natural fiber on the mechanical properties and spalling resistance of UHCP were conducted. The residual mechanical properties of UHPC with natural fibers were tested after heating to different temperatures. Spalling behavior of UHPC with natural fibers is also assessed by heating the samples according to ISO 834 fire curve. A range of analytical, physical and microscopic characterization techniques was also used on the concrete samples before and after being subjected to elevated temperature to investigate the phase and microstructural change of the sample. The findings show that natural fibers are able to improve fire resistance of UHPC. Adding natural fibers can prevent UHPC from spalling at high temperature. This study provides an alternative, which is at low cost and environmentally friendly, to prevent spalling of UHPC. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=high%20temperature" title="high temperature">high temperature</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20fiber" title=" natural fiber"> natural fiber</a>, <a href="https://publications.waset.org/abstracts/search?q=spalling" title=" spalling"> spalling</a>, <a href="https://publications.waset.org/abstracts/search?q=ultra-high%20performance%20concrete" title=" ultra-high performance concrete"> ultra-high performance concrete</a> </p> <a href="https://publications.waset.org/abstracts/108461/investigation-on-the-fire-resistance-of-ultra-high-performance-concrete-with-natural-fibers" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/108461.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">177</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9238</span> Estimation of the Dynamic Fragility of Padre Jacinto Zamora Bridge Due to Traffic Loads</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kimuel%20Suyat">Kimuel Suyat</a>, <a href="https://publications.waset.org/abstracts/search?q=Francis%20Aldrine%20Uy"> Francis Aldrine Uy</a>, <a href="https://publications.waset.org/abstracts/search?q=John%20Paul%20%20Carreon"> John Paul Carreon</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Philippines, composed of many islands, is connected with approximately 8030 bridges. Continuous evaluation of the structural condition of these bridges is needed to safeguard the safety of the general public. With most bridges reaching its design life, retrofitting and replacement may be needed. Concerned government agencies allocate huge costs for periodic monitoring and maintenance of these structures. The rising volume of traffic and aging of these infrastructures is challenging structural engineers to give rise for structural health monitoring techniques. Numerous techniques are already proposed and some are now being employed in other countries. Vibration Analysis is one way. The natural frequency and vibration of a bridge are design criteria in ensuring the stability, safety and economy of the structure. Its natural frequency must not be so high so as not to cause discomfort and not so low that the structure is so stiff causing it to be both costly and heavy. It is well known that the stiffer the member is, the more load it attracts. The frequency must not also match the vibration caused by the traffic loads. If this happens, a resonance occurs. Vibration that matches a systems frequency will generate excitation and when this exceeds the member’s limit, a structural failure will happen. This study presents a method for calculating dynamic fragility through the use of vibration-based monitoring system. Dynamic fragility is the probability that a structural system exceeds a limit state when subjected to dynamic loads. The bridge is modeled in SAP2000 based from the available construction drawings provided by the Department of Public Works and Highways. It was verified and adjusted based from the actual condition of the bridge. The bridge design specifications are also checked using nondestructive tests. The approach used in this method properly accounts the uncertainty of observed values and code-based structural assumptions. The vibration response of the structure due to actual loads is monitored using installed sensors on the bridge. From the determinacy of these dynamic characteristic of a system, threshold criteria can be established and fragility curves can be estimated. This study conducted in relation with the research project between Department of Science and Technology, Mapúa Institute of Technology, and the Department of Public Works and Highways also known as Mapúa-DOST Smart Bridge Project deploys Structural Health Monitoring Sensors at Zamora Bridge. The bridge is selected in coordination with the Department of Public Works and Highways. The structural plans for the bridge are also readily available. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=structural%20health%20monitoring" title="structural health monitoring">structural health monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20characteristic" title=" dynamic characteristic"> dynamic characteristic</a>, <a href="https://publications.waset.org/abstracts/search?q=threshold%20criteria" title=" threshold criteria"> threshold criteria</a>, <a href="https://publications.waset.org/abstracts/search?q=traffic%20loads" title=" traffic loads"> traffic loads</a> </p> <a href="https://publications.waset.org/abstracts/75210/estimation-of-the-dynamic-fragility-of-padre-jacinto-zamora-bridge-due-to-traffic-loads" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/75210.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">270</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9237</span> Enhancing Power System Resilience: An Adaptive Under-Frequency Load Shedding Scheme Incorporating PV Generation and Fast Charging Stations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sami%20M.%20Alshareef">Sami M. Alshareef</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the rapidly evolving energy landscape, the integration of renewable energy sources and the electrification of transportation are essential steps toward achieving sustainability goals. However, these advancements introduce new challenges, particularly in maintaining frequency stability due to variable photovoltaic (PV) generation and the growing demand for fast charging stations. The variability of photovoltaic (PV) generation due to weather conditions can disrupt the balance between generation and load, resulting in frequency deviations. To ensure the stability of power systems, it is imperative to develop effective under frequency load-shedding schemes. This research proposal presents an adaptive under-frequency load shedding scheme based on the power swing equation, designed explicitly for the IEEE-9 Bus Test System, that includes PV generation and fast charging stations. This research aims to address these challenges by developing an advanced scheme that dynamically disconnects fast charging stations based on power imbalances. The scheme prioritizes the disconnection of stations near affected areas to expedite system frequency stabilization. To achieve these goals, the research project will leverage the power swing equation, a widely recognized model for analyzing system dynamics during under-frequency events. By utilizing this equation, the proposed scheme will adaptively adjust the load-shedding process in real-time to maintain frequency stability and prevent power blackouts. The research findings will support the transition towards sustainable energy systems by ensuring a reliable and uninterrupted electricity supply while enhancing the resilience and stability of power systems during under-frequency events. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=load%20shedding" title="load shedding">load shedding</a>, <a href="https://publications.waset.org/abstracts/search?q=fast%20charging%20stations" title=" fast charging stations"> fast charging stations</a>, <a href="https://publications.waset.org/abstracts/search?q=pv%20generation" title=" pv generation"> pv generation</a>, <a href="https://publications.waset.org/abstracts/search?q=power%20system%20resilience" title=" power system resilience"> power system resilience</a> </p> <a href="https://publications.waset.org/abstracts/169723/enhancing-power-system-resilience-an-adaptive-under-frequency-load-shedding-scheme-incorporating-pv-generation-and-fast-charging-stations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/169723.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">81</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9236</span> Removal of Vanadium from Industrial Effluents by Natural Ion Exchanger</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Shashikant%20R.%20Kuchekar">Shashikant R. Kuchekar</a>, <a href="https://publications.waset.org/abstracts/search?q=Haribhau%20R.%20Aher"> Haribhau R. Aher</a>, <a href="https://publications.waset.org/abstracts/search?q=Priti%20M.%20Dhage"> Priti M. Dhage</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The removal vanadium from aqueous solution using natural exchanger was investigated. The effects of pH, contact time and exchanger dose were studied at ambient temperature (25 <sup>0</sup>C ± 2 <sup>0</sup>C). The equilibrium process was described by the Langmuir isotherm model with adsorption capacity for vanadium. The natural exchanger i.e. tamarindus seeds powder was treated with formaldehyde and sulpuric acid to increase the adsorptivity of metals. The maximum exchange level was attained as 80.1% at pH 3 with exchanger dose 5 g and contact time 60 min. Method is applied for removal of vanadium from industrial effluents. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=industrial%20effluent" title="industrial effluent">industrial effluent</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20ion%20exchange" title=" natural ion exchange"> natural ion exchange</a>, <a href="https://publications.waset.org/abstracts/search?q=Tamarindous%20indica" title=" Tamarindous indica"> Tamarindous indica</a>, <a href="https://publications.waset.org/abstracts/search?q=vanadium" title=" vanadium"> vanadium</a> </p> <a href="https://publications.waset.org/abstracts/68740/removal-of-vanadium-from-industrial-effluents-by-natural-ion-exchanger" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68740.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads 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