CINXE.COM

<!DOCTYPE html> <html lang="en" dir="ltr"> <head>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-P63WKM1TM1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-P63WKM1TM1'); </script>  <script type="text/javascript" > (function(m,e,t,r,i,k,a){m[i]=m[i]||function(){(m[i].a=m[i].a||[]).push(arguments)}; m[i].l=1*new Date(); for (var j = 0; j < document.scripts.length; j++) {if (document.scripts[j].src === r) { return; }} k=e.createElement(t),a=e.getElementsByTagName(t)[0],k.async=1,k.src=r,a.parentNode.insertBefore(k,a)}) (window, document, "script", "https://mc.yandex.ru/metrika/tag.js", "ym"); ym(55165297, "init", { clickmap:false, trackLinks:true, accurateTrackBounce:true, webvisor:false }); </script> <noscript><div><img src="https://mc.yandex.ru/watch/55165297" style="position:absolute; left:-9999px;" alt="" /></div></noscript>    <title>Search results for: very low frequency</title> <meta name="description" content="Search results for: very low frequency"> <meta name="keywords" content="very low 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 navbar-toggler ml-auto" type="button" data-toggle="collapse" data-target="#navbarMenu" aria-controls="navbarMenu" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="w-100"> <div class="d-none d-lg-flex flex-row-reverse"> <form method="get" action="https://waset.org/search" class="form-inline my-2 my-lg-0"> <input class="form-control mr-sm-2" type="search" placeholder="Search Conferences" value="very low frequency" name="q" aria-label="Search"> <button class="btn btn-light my-2 my-sm-0" type="submit"><i class="fas fa-search"></i></button> </form> </div> <div class="collapse navbar-collapse mt-1" id="navbarMenu"> <ul class="navbar-nav ml-auto align-items-center" id="mainNavMenu"> <li class="nav-item"> <a class="nav-link" href="https://waset.org/conferences" title="Conferences in 2024/2025/2026">Conferences</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/disciplines" title="Disciplines">Disciplines</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/committees" rel="nofollow">Committees</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownPublications" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Publications </a> <div class="dropdown-menu" aria-labelledby="navbarDropdownPublications"> <a class="dropdown-item" href="https://publications.waset.org/abstracts">Abstracts</a> <a class="dropdown-item" href="https://publications.waset.org">Periodicals</a> <a class="dropdown-item" href="https://publications.waset.org/archive">Archive</a> </div> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/page/support" title="Support">Support</a> </li> </ul> </div> </div> </nav> </div> </header> <main> <div class="container mt-4"> <div class="row"> <div class="col-md-9 mx-auto"> <form method="get" 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="very low 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> 4005</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: very low frequency</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">4005</span> Comparison of Frequency-Domain Contention Schemes in Wireless LANs </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Li%20Feng">Li Feng</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In IEEE 802.11 networks, it is well known that the traditional time-domain contention often leads to low channel utilization. The first frequency-domain contention scheme, the time to frequency (T2F), has recently been proposed to improve the channel utilization and has attracted a great deal of attention. In this paper, we survey the latest research progress on the weighed frequency-domain contention. We present the basic ideas, work principles of these related schemes and point out their differences. This paper is very useful for further study on frequency-domain contention. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=802.11" title="802.11">802.11</a>, <a href="https://publications.waset.org/abstracts/search?q=wireless%20LANs" title=" wireless LANs"> wireless LANs</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency-domain%20contention" title=" frequency-domain contention"> frequency-domain contention</a>, <a href="https://publications.waset.org/abstracts/search?q=T2F" title=" T2F"> T2F</a> </p> <a href="https://publications.waset.org/abstracts/42959/comparison-of-frequency-domain-contention-schemes-in-wireless-lans" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/42959.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">459</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">4004</span> Experimental Investigation on the Optimal Operating Frequency of a Thermoacoustic Refrigerator</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kriengkrai%20Assawamartbunlue">Kriengkrai Assawamartbunlue</a>, <a href="https://publications.waset.org/abstracts/search?q=Channarong%20Wantha"> Channarong Wantha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the effects of the mean operating pressure on the optimal operating frequency based on temperature differences across stack ends in a thermoacoustic refrigerator. In addition to the length of the resonance tube, components of the thermoacoustic refrigerator have an influence on the operating frequency due to their acoustic properties, i.e. absorptivity, reflectivity and transmissivity. The interference of waves incurs and distorts the original frequency generated by the driver so that the optimal operating frequency differs from the designs. These acoustic properties are not parameters in the designs and it is very complicated to infer their responses. A prototype thermoacoustic refrigerator is constructed and used to investigate its optimal operating frequency compared to the design at various operating pressures. Helium and air are used as working fluids during the experiments. The results indicate that the optimal operating frequency of the prototype thermoacoustic refrigerator using helium is at 6 bar and 490Hz or approximately 20% away from the design frequency. The optimal operating frequency at other mean pressures differs from the design in an unpredictable manner, however, the optimal operating frequency and pressure can be identified by testing. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20properties" title="acoustic properties">acoustic properties</a>, <a href="https://publications.waset.org/abstracts/search?q=Carnot%E2%80%99s%20efficiency" title=" Carnot’s efficiency"> Carnot’s efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=interference%20of%20waves" title=" interference of waves"> interference of waves</a>, <a href="https://publications.waset.org/abstracts/search?q=operating%20pressure" title=" operating pressure"> operating pressure</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20operating%20frequency" title=" optimal operating frequency"> optimal operating frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=stack%20performance" title=" stack performance"> stack performance</a>, <a href="https://publications.waset.org/abstracts/search?q=standing%20wave" title=" standing wave"> standing wave</a>, <a href="https://publications.waset.org/abstracts/search?q=thermoacoustic%20refrigerator" title=" thermoacoustic refrigerator"> thermoacoustic refrigerator</a> </p> <a href="https://publications.waset.org/abstracts/23908/experimental-investigation-on-the-optimal-operating-frequency-of-a-thermoacoustic-refrigerator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/23908.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">486</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">4003</span> Investigation of the Effects of Sampling Frequency on the THD of 3-Phase Inverters Using Space Vector Modulation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khattab%20Al%20Qaisi">Khattab Al Qaisi</a>, <a href="https://publications.waset.org/abstracts/search?q=Nicholas%20Bowring"> Nicholas Bowring</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the simulation results of the effects of sampling frequency on the total harmonic distortion (THD) of three-phase inverters using the space vector pulse width modulation (SVPWM) and space vector control (SVC) algorithms. The relationship between the variables was studied using curve fitting techniques, and it has been shown that, for 50 Hz inverters, there is an exponential relation between the sampling frequency and THD up to around 8500 Hz, beyond which the performance of the model becomes irregular, and there is an negative exponential relation between the sampling frequency and the marginal improvement to the THD. It has also been found that the performance of SVPWM is better than that of SVC with the same sampling frequency in most frequency range, including the range where the performance of the former is irregular. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DSI" title="DSI">DSI</a>, <a href="https://publications.waset.org/abstracts/search?q=SVPWM" title=" SVPWM"> SVPWM</a>, <a href="https://publications.waset.org/abstracts/search?q=THD" title=" THD"> THD</a>, <a href="https://publications.waset.org/abstracts/search?q=DC-AC%20converter" title=" DC-AC converter"> DC-AC converter</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20frequency" title=" sampling frequency"> sampling frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=performance" title=" performance"> performance</a> </p> <a href="https://publications.waset.org/abstracts/17856/investigation-of-the-effects-of-sampling-frequency-on-the-thd-of-3-phase-inverters-using-space-vector-modulation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17856.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">485</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">4002</span> Determining Efficiency of Frequency Control System of Karkheh Power Plant in Main Network</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ferydon%20Salehifar">Ferydon Salehifar</a>, <a href="https://publications.waset.org/abstracts/search?q=Hassan%20Safarikia"> Hassan Safarikia</a>, <a href="https://publications.waset.org/abstracts/search?q=Hossein%20Boromandfar"> Hossein Boromandfar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Karkheh plant in Iran's Khuzestan province and is located in the city Andimeshk. The plant has a production capacity of 400 MW units with water and three hours. One of the important parameters of each country's power grid stability is the stability of the power grid is affected by the voltage and frequency In plants, the amount of active power frequency control is done so that when the unit is placed in the frequency control their productivity is a function of frequency and output power varies with frequency. Produced by hydroelectric power plants with the water level behind the dam has a direct relationship And to decrease and increase the water level behind the dam in order to reduce the power output increases But these changes have a different interval is due to some mechanical problems such as turbine cavitation and vibration are limited. In this study, the range of the frequency control can be Karkheh manufacturing plants have been identified and their effectiveness has been determined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Karkheh%20power" title="Karkheh power">Karkheh power</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20control%20system" title=" frequency control system"> frequency control system</a>, <a href="https://publications.waset.org/abstracts/search?q=active%20power" title=" active power"> active power</a>, <a href="https://publications.waset.org/abstracts/search?q=efficiency" title=" efficiency"> efficiency</a> </p> <a href="https://publications.waset.org/abstracts/25787/determining-efficiency-of-frequency-control-system-of-karkheh-power-plant-in-main-network" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/25787.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">620</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">4001</span> Optimal ECG Sampling Frequency for Multiscale Entropy-Based HRV</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Manjit%20Singh">Manjit Singh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Multiscale entropy (MSE) is an extensively used index to provide a general understanding of multiple complexity of physiologic mechanism of heart rate variability (HRV) that operates on a wide range of time scales. Accurate selection of electrocardiogram (ECG) sampling frequency is an essential concern for clinically significant HRV quantification; high ECG sampling rate increase memory requirements and processing time, whereas low sampling rate degrade signal quality and results in clinically misinterpreted HRV. In this work, the impact of ECG sampling frequency on MSE based HRV have been quantified. MSE measures are found to be sensitive to ECG sampling frequency and effect of sampling frequency will be a function of time scale. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ECG%20%28electrocardiogram%29" title="ECG (electrocardiogram)">ECG (electrocardiogram)</a>, <a href="https://publications.waset.org/abstracts/search?q=heart%20rate%20variability%20%28HRV%29" title=" heart rate variability (HRV)"> heart rate variability (HRV)</a>, <a href="https://publications.waset.org/abstracts/search?q=multiscale%20entropy" title=" multiscale entropy"> multiscale entropy</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20frequency" title=" sampling frequency"> sampling frequency</a> </p> <a href="https://publications.waset.org/abstracts/78603/optimal-ecg-sampling-frequency-for-multiscale-entropy-based-hrv" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78603.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">271</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">4000</span> Dynamic Response of Structure-Raft-Pile-Soil with Respect to System Frequency</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=B.%20Razmi">B. Razmi</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20Rafiee"> F. Rafiee</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Baziar"> M. Baziar</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Saeedi%20Azizkandi"> A. Saeedi Azizkandi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the present research, a series of 3-D finite element numerical modeling was performed to study the effect of system frequency and excitation specifications on the internal forces of the piled raft (PR) system in a dry sand layer. The results of numerical simulations were first compared with those associated with centrifuge tests. The natural frequency of superstructure, modeled on the piled raft foundation, was smaller than the natural frequency of the fixed-base super-structure. This difference was greater for super-structures with higher frequencies. In PR systems, the excitation with a frequency close to the system frequency produced the largest responses. Furthermore, based on the results of presented numerical analyses, ignoring the interactions and characteristics of all components of a pile-raft-structure, may lead to highly uneconomical design. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=centrifuge%20test" title="centrifuge test">centrifuge test</a>, <a href="https://publications.waset.org/abstracts/search?q=excitation%20frequency" title=" excitation frequency"> excitation frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency%20of%20super-structure" title=" natural frequency of super-structure"> natural frequency of super-structure</a>, <a href="https://publications.waset.org/abstracts/search?q=piled%20raft%20foundation" title=" piled raft foundation"> piled raft foundation</a>, <a href="https://publications.waset.org/abstracts/search?q=3-D%20finite%20element%20model" title=" 3-D finite element model"> 3-D finite element model</a> </p> <a href="https://publications.waset.org/abstracts/150187/dynamic-response-of-structure-raft-pile-soil-with-respect-to-system-frequency" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/150187.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">117</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">3999</span> Frequency Transformation with Pascal Matrix Equations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Phuoc%20Si%20Nguyen">Phuoc Si Nguyen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Frequency transformation with Pascal matrix equations is a method for transforming an electronic filter (analogue or digital) into another filter. The technique is based on frequency transformation in the s-domain, bilinear z-transform with pre-warping frequency, inverse bilinear transformation and a very useful application of the Pascal’s triangle that simplifies computing and enables calculation by hand when transforming from one filter to another. This paper will introduce two methods to transform a filter into a digital filter: frequency transformation from the s-domain into the z-domain; and frequency transformation in the z-domain. Further, two Pascal matrix equations are derived: an analogue to digital filter Pascal matrix equation and a digital to digital filter Pascal matrix equation. These are used to design a desired digital filter from a given filter. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=frequency%20transformation" title="frequency transformation">frequency transformation</a>, <a href="https://publications.waset.org/abstracts/search?q=bilinear%20z-transformation" title=" bilinear z-transformation"> bilinear z-transformation</a>, <a href="https://publications.waset.org/abstracts/search?q=pre-warping%20frequency" title=" pre-warping frequency"> pre-warping frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=digital%20filters" title=" digital filters"> digital filters</a>, <a href="https://publications.waset.org/abstracts/search?q=analog%20filters" title=" analog filters"> analog filters</a>, <a href="https://publications.waset.org/abstracts/search?q=pascal%E2%80%99s%20triangle" title=" pascal’s triangle"> pascal’s triangle</a> </p> <a href="https://publications.waset.org/abstracts/34866/frequency-transformation-with-pascal-matrix-equations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/34866.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">3998</span> Dielectric Properties of Ni-Al Nano Ferrites Synthesized by Citrate Gel Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=D.%20Ravinder">D. Ravinder</a>, <a href="https://publications.waset.org/abstracts/search?q=K.%20S.%20Nagaraju"> K. S. Nagaraju </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ni–Al ferrite with composition of NiAlxFe2-xO4 (x=0.2, 0.4 0.6, and 0.8, ) were prepared by citrate gel method. The dielectric properties for all the samples were investigated at room temperature as a function of frequency. The dielectric constant shows dispersion in the lower frequency region and remains almost constant at higher frequencies. The frequency dependence of dielectric loss tangent (tanδ) is found to be abnormal, giving a peak at certain frequency for mixed Ni-Al ferrites. A qualitative explanation is given for the composition and frequency dependence of the dielectric loss tangent. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ferrites" title="ferrites">ferrites</a>, <a href="https://publications.waset.org/abstracts/search?q=citrate%20method" title=" citrate method"> citrate method</a>, <a href="https://publications.waset.org/abstracts/search?q=lattice%20parameter" title=" lattice parameter"> lattice parameter</a>, <a href="https://publications.waset.org/abstracts/search?q=dielectric%20constant" title=" dielectric constant"> dielectric constant</a> </p> <a href="https://publications.waset.org/abstracts/57941/dielectric-properties-of-ni-al-nano-ferrites-synthesized-by-citrate-gel-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/57941.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">303</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">3997</span> Revised Tower Earthing Design in High-Voltage Transmission Network for High-Frequency Lightning Condition</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Azwadi%20Mohamad">Azwadi Mohamad</a>, <a href="https://publications.waset.org/abstracts/search?q=Pauzi%20Yahaya"> Pauzi Yahaya</a>, <a href="https://publications.waset.org/abstracts/search?q=Nadiah%20Hudi"> Nadiah Hudi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Earthing system for high-voltage transmission tower is designed to protect the working personnel and equipments, and to maintain the quality of supply during fault. The existing earthing system for transmission towers in TNB’s system is purposely designed for normal power frequency (low-frequency) fault conditions that take into account the step and touch voltages. This earthing design is found to be inapt for lightning (transient) condition to a certain extent, which involves a high-frequency domain. The current earthing practice of laying the electrodes radially in straight 60 m horizontal lines under the ground, in order to achieve the specified impedance value of less than 10 Ω, was deemed ineffective in reducing the high-frequency impedance. This paper introduces a new earthing design that produces low impedance value at the high-frequency domain, without compromising the performance of low-frequency impedance. The performances of this new earthing design, as well as the existing design, are simulated for various soil resistivity values at varying frequency. The proposed concentrated earthing design is found to possess low TFR value at both low and high-frequency. A good earthing design should have a fine balance between compact and radial electrodes under the ground. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=earthing%20design" title="earthing design">earthing design</a>, <a href="https://publications.waset.org/abstracts/search?q=high-frequency" title=" high-frequency"> high-frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=lightning" title=" lightning"> lightning</a>, <a href="https://publications.waset.org/abstracts/search?q=tower%20footing%20impedance" title=" tower footing impedance"> tower footing impedance</a> </p> <a href="https://publications.waset.org/abstracts/129491/revised-tower-earthing-design-in-high-voltage-transmission-network-for-high-frequency-lightning-condition" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/129491.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">161</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">3996</span> Signal On-Off Ratio and Output Frequency Analysis of Semiconductor Electron-Interference Device</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tomotaka%20Aoki">Tomotaka Aoki</a>, <a href="https://publications.waset.org/abstracts/search?q=Isao%20Tomita"> Isao Tomita</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We examined the on-off ratio and frequency components of output signals from an electron-interference device made of GaAs/AlₓGa₁₋ₓAs by solving the time-dependent Schrödinger's equation on conducting electrons in the channel waveguide of the device. For electron-wave modulation, a periodic voltage of frequency f was applied to the channel. Furthermore, we examined the voltage-amplitude dependence of the signals in time and frequency domains and found that large applied voltage deformed the output-signal waveform and created additional side modes (frequencies) near the modulation frequency f and that there was a trade-off between on-off ratio and side-mode creation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=electrical%20conduction" title="electrical conduction">electrical conduction</a>, <a href="https://publications.waset.org/abstracts/search?q=electron%20interference" title=" electron interference"> electron interference</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20spectrum" title=" frequency spectrum"> frequency spectrum</a>, <a href="https://publications.waset.org/abstracts/search?q=on-off%20ratio" title=" on-off ratio"> on-off ratio</a> </p> <a href="https://publications.waset.org/abstracts/145444/signal-on-off-ratio-and-output-frequency-analysis-of-semiconductor-electron-interference-device" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/145444.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">121</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">3995</span> Slugging Frequency Correlation for High Viscosity Oil-Gas Flow in Horizontal Pipeline </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=B.%20Y.%20Danjuma">B. Y. Danjuma</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Archibong-Eso"> A. Archibong-Eso</a>, <a href="https://publications.waset.org/abstracts/search?q=Aliyu%20M.%20Aliyu"> Aliyu M. Aliyu</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Yeung"> H. Yeung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this experimental investigation, a new data for slugging frequency for high viscosity oil-gas flow are reported. Scale experiments were carried out using a mixture of air and mineral oil as the liquid phase in a 17 m long horizontal pipe with 0.0762 ID. The data set was acquired using two high-speed Gamma Densitometers at a data acquisition frequency of 250 Hz over a time interval of 30 seconds. For the range of flow conditions investigated, increase in liquid oil viscosity was observed to strongly influence the slug frequency. A comparison of the present data with prediction models available in the literature revealed huge discrepancies. A new correlation incorporating the effect of viscosity on slug frequency has been proposed for the horizontal flow, which represents the main contribution of this work. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=gamma%20densitometer" title="gamma densitometer">gamma densitometer</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20pattern" title=" flow pattern"> flow pattern</a>, <a href="https://publications.waset.org/abstracts/search?q=pressure%20gradient" title=" pressure gradient"> pressure gradient</a>, <a href="https://publications.waset.org/abstracts/search?q=slug%20frequency" title=" slug frequency"> slug frequency</a> </p> <a href="https://publications.waset.org/abstracts/36688/slugging-frequency-correlation-for-high-viscosity-oil-gas-flow-in-horizontal-pipeline" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/36688.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">412</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">3994</span> Dielectric Properties in Frequency Domain of Main Insulation System of Printed Circuit Board</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Xize%20Dai">Xize Dai</a>, <a href="https://publications.waset.org/abstracts/search?q=Jian%20Hao"> Jian Hao</a>, <a href="https://publications.waset.org/abstracts/search?q=Claus%20Leth%20Bak"> Claus Leth Bak</a>, <a href="https://publications.waset.org/abstracts/search?q=Gian%20Carlo%20Montanari"> Gian Carlo Montanari</a>, <a href="https://publications.waset.org/abstracts/search?q=Huai%20Wang"> Huai Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Printed Circuit Board (PCB) is a critical component applicable to power electronics systems, especially for high-voltage applications involving several high-voltage and high-frequency SiC/GaN devices. The insulation system of PCB is facing more challenges from high-voltage and high-frequency stress that can alter the dielectric properties. Dielectric properties of the PCB insulation system also determine the electrical field distribution that correlates with intrinsic and extrinsic aging mechanisms. Hence, investigating the dielectric properties in the frequency domain of the PCB insulation system is a must. The paper presents the frequency-dependent, temperature-dependent, and voltage-dependent dielectric properties, permittivity, conductivity, and dielectric loss tangents of PCB insulation systems. The dielectric properties mechanisms associated with frequency, temperature, and voltage are revealed from the design perspective. It can be concluded that the dielectric properties of PCB in the frequency domain show a strong dependence on voltage, frequency, and temperature. The voltage-, frequency-, and temperature-dependent dielectric properties are associated with intrinsic conduction behavior and polarization patterns from the perspective of dielectric theory. The results may provide some reference for the PCB insulation system design in high voltage, high frequency, and high-temperature power electronics applications. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=electrical%20insulation%20system" title="electrical insulation system">electrical insulation system</a>, <a href="https://publications.waset.org/abstracts/search?q=dielectric%20properties" title=" dielectric properties"> dielectric properties</a>, <a href="https://publications.waset.org/abstracts/search?q=high%20voltage%20and%20frequency" title=" high voltage and frequency"> high voltage and frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=printed%20circuit%20board" title=" printed circuit board"> printed circuit board</a> </p> <a href="https://publications.waset.org/abstracts/168071/dielectric-properties-in-frequency-domain-of-main-insulation-system-of-printed-circuit-board" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/168071.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">94</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">3993</span> Parabolic Impact Law of High Frequency Exchanges on Price Formation in Commodities Market</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=L.%20Maiza">L. Maiza</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Cantagrel"> A. Cantagrel</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Forestier"> M. Forestier</a>, <a href="https://publications.waset.org/abstracts/search?q=G.%20Laucoin"> G. Laucoin</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20Regali"> T. Regali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Evaluation of High Frequency Trading (HFT) impact on financial markets is very important for traders who use market analysis to detect winning transaction opportunity. Analysis of HFT data on tobacco commodity market is discussed here and interesting linear relationship has been shown between trading frequency and difference between averaged trading prices above and below considered trading frequency. This may open new perspectives on markets data understanding and could provide possible interpretation of Adam Smith invisible hand. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=financial%20market" title="financial market">financial market</a>, <a href="https://publications.waset.org/abstracts/search?q=high%20frequency%20trading" title=" high frequency trading"> high frequency trading</a>, <a href="https://publications.waset.org/abstracts/search?q=analysis" title=" analysis"> analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=impacts" title=" impacts"> impacts</a>, <a href="https://publications.waset.org/abstracts/search?q=Adam%20Smith%20invisible%20hand" title=" Adam Smith invisible hand"> Adam Smith invisible hand</a> </p> <a href="https://publications.waset.org/abstracts/35722/parabolic-impact-law-of-high-frequency-exchanges-on-price-formation-in-commodities-market" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35722.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">359</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">3992</span> Frequency-Dependent and Full Range Tunable Phase Shifter</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yufu%20Yin">Yufu Yin</a>, <a href="https://publications.waset.org/abstracts/search?q=Tao%20Lin"> Tao Lin</a>, <a href="https://publications.waset.org/abstracts/search?q=Shanghong%20Zhao"> Shanghong Zhao</a>, <a href="https://publications.waset.org/abstracts/search?q=Zihang%20Zhu"> Zihang Zhu</a>, <a href="https://publications.waset.org/abstracts/search?q=Xuan%20Li"> Xuan Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Wei%20Jiang"> Wei Jiang</a>, <a href="https://publications.waset.org/abstracts/search?q=Qiurong%20Zheng"> Qiurong Zheng</a>, <a href="https://publications.waset.org/abstracts/search?q=Hui%20Wang"> Hui Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a frequency-dependent and tunable phase shifter is proposed and numerically analyzed. The key devices are the dual-polarization binary phase shift keying modulator (DP-BPSK) and the fiber Bragg grating (FBG). The phase-frequency response of the FBG is employed to determine the frequency-dependent phase shift. The simulation results show that a linear phase shift of the recovered output microwave signal which depends on the frequency of the input RF signal is achieved. In addition, by adjusting the power of the RF signal, the full range phase shift from 0° to 360° can be realized. This structure shows the spurious free dynamic range (SFDR) of 70.90 dB·Hz<sup>2/3</sup> and 72.11 dB·Hz<sup>2/3</sup> under different RF powers. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microwave%20photonics" title="microwave photonics">microwave photonics</a>, <a href="https://publications.waset.org/abstracts/search?q=phase%20shifter" title=" phase shifter"> phase shifter</a>, <a href="https://publications.waset.org/abstracts/search?q=spurious%20free%20dynamic%20range" title=" spurious free dynamic range"> spurious free dynamic range</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency-dependent" title=" frequency-dependent"> frequency-dependent</a> </p> <a href="https://publications.waset.org/abstracts/95223/frequency-dependent-and-full-range-tunable-phase-shifter" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/95223.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">296</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">3991</span> Monitoring of Spectrum Usage and Signal Identification Using Cognitive Radio</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=O.%20S.%20Omorogiuwa">O. S. Omorogiuwa</a>, <a href="https://publications.waset.org/abstracts/search?q=E.%20J.%20Omozusi"> E. J. Omozusi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The monitoring of spectrum usage and signal identification, using cognitive radio, is done to identify frequencies that are vacant for reuse. It has been established that ‘internet of things’ device uses secondary frequency which is free, thereby facing the challenge of interference from other users, where some primary frequencies are not being utilised. The design was done by analysing a specific frequency spectrum, checking if all the frequency stations that range from 87.5-108 MHz are presently being used in Benin City, Edo State, Nigeria. From the results, it was noticed that by using Software Defined Radio/Simulink, we were able to identify vacant frequencies in the range of frequency under consideration. Also, we were able to use the significance of energy detection threshold to reuse this vacant frequency spectrum, when the cognitive radio displays a zero output (that is decision H0), meaning that the channel is unoccupied. Hence, the analysis was able to find the spectrum hole and identify how it can be reused. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=spectrum" title="spectrum">spectrum</a>, <a href="https://publications.waset.org/abstracts/search?q=interference" title=" interference"> interference</a>, <a href="https://publications.waset.org/abstracts/search?q=telecommunication" title=" telecommunication"> telecommunication</a>, <a href="https://publications.waset.org/abstracts/search?q=cognitive%20radio" title=" cognitive radio"> cognitive radio</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency" title=" frequency"> frequency</a> </p> <a href="https://publications.waset.org/abstracts/93900/monitoring-of-spectrum-usage-and-signal-identification-using-cognitive-radio" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/93900.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">224</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">3990</span> Optimal Voltage and Frequency Control of a Microgrid Using the Harmony Search Algorithm</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hossein%20Abbasi">Hossein Abbasi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The stability is an important topic to plan and manage the energy in the microgrids as the same as the conventional power systems. The voltage and frequency stability is one of the most important issues recently studied in microgrids. The objectives of this paper are the modelling and designing of the components and optimal controllers for the voltage and frequency control of the AC/DC hybrid microgrid under the different disturbances. Since the PI controllers have the advantages of simple structure and easy implementation, so they are designed and modeled in this paper. The harmony search (HS) algorithm is used to optimize the controllers’ parameters. According to the achieved results, the PI controllers have a good performance in voltage and frequency control of the microgrid. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=frequency%20control" title="frequency control">frequency control</a>, <a href="https://publications.waset.org/abstracts/search?q=HS%20algorithm" title=" HS algorithm"> HS algorithm</a>, <a href="https://publications.waset.org/abstracts/search?q=microgrid" title=" microgrid"> microgrid</a>, <a href="https://publications.waset.org/abstracts/search?q=PI%20controller" title=" PI controller"> PI controller</a>, <a href="https://publications.waset.org/abstracts/search?q=voltage%20control" title=" voltage control"> voltage control</a> </p> <a href="https://publications.waset.org/abstracts/42762/optimal-voltage-and-frequency-control-of-a-microgrid-using-the-harmony-search-algorithm" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/42762.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">391</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">3989</span> Frequency Controller Design for Distributed Generation by Load Shedding: Multi-Agent Systems Approach</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20R.%20Vaezi">M. R. Vaezi</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20Ghasemi"> R. Ghasemi</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Akramizadeh"> A. Akramizadeh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Frequency stability of microgrids under islanded operation attracts particular attention recently. A new cooperative frequency control strategy based on centralized multi-agent system (CMAS) is proposed in this study. On this strategy, agents sent data and furthermore each component has its own to center operating decisions (MGCC). After deciding on the information, they are returned. Frequency control strategies include primary and secondary frequency control and disposal of multi-stage load in which this study will also provide a method and algorithm for load shedding. This could also be a big problem for the performance of micro-grid in times of disaster. The simulation results show the promising performance of the proposed structure of the controller based on multi agent systems. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=frequency%20control" title="frequency control">frequency control</a>, <a href="https://publications.waset.org/abstracts/search?q=islanded%20microgrid" title=" islanded microgrid"> islanded microgrid</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-agent%20system" title=" multi-agent system"> multi-agent system</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20shedding" title=" load shedding "> load shedding </a> </p> <a href="https://publications.waset.org/abstracts/15787/frequency-controller-design-for-distributed-generation-by-load-shedding-multi-agent-systems-approach" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/15787.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">463</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">3988</span> Vibration Absorption Strategy for Multi-Frequency Excitation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Der%20Chyan%20Lin">Der Chyan Lin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Since the early introduction by Ormondroyd and Den Hartog, vibration absorber (VA) has become one of the most commonly used vibration mitigation strategies. The strategy is most effective for a primary plant subjected to a single frequency excitation. For continuous systems, notable advances in vibration absorption in the multi-frequency system were made. However, the efficacy of the VA strategy for systems under multi-frequency excitation is not well understood. For example, for an N degrees-of-freedom (DOF) primary-absorber system, there are N 'peak' frequencies of large amplitude vibration per every new excitation frequency. In general, the usable range for vibration absorption can be greatly reduced as a result. Frequency modulated harmonic excitation is a commonly seen multi-frequency excitation example: f(t) = cos(ϖ(t)t) where ϖ(t)=ω(1+α sin⁡(δt)). It is known that f(t) has a series expansion given by the Bessel function of the first kind, which implies an infinity of forcing frequencies in the frequency modulated harmonic excitation. For an SDOF system of natural frequency ωₙ subjected to f(t), it can be shown that amplitude peaks emerge at ω₍ₚ,ₖ₎=(ωₙ ± 2kδ)/(α ∓ 1),k∈Z; i.e., there is an infinity of resonant frequencies ω₍ₚ,ₖ₎, k∈Z, making the use of VA strategy ineffective. In this work, we propose an absorber frequency placement strategy for SDOF vibration systems subjected to frequency-modulated excitation. An SDOF linear mass-spring system coupled to lateral absorber systems is used to demonstrate the ideas. Although the mechanical components are linear, the governing equations for the coupled system are nonlinear. We show using N identical absorbers, for N ≫ 1, that (a) there is a cluster of N+1 natural frequencies around every natural absorber frequency, and (b) the absorber frequencies can be moved away from the plant's resonance frequency (ω₀) as N increases. Moreover, we also show the bandwidth of the VA performance increases with N. The derivations of the clustering and bandwidth widening effect will be given, and the superiority of the proposed strategy will be demonstrated via numerical experiments. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bessel%20function" title="Bessel function">Bessel function</a>, <a href="https://publications.waset.org/abstracts/search?q=bandwidth" title=" bandwidth"> bandwidth</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20modulated%20excitation" title=" frequency modulated excitation"> frequency modulated excitation</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration%20absorber" title=" vibration absorber"> vibration absorber</a> </p> <a href="https://publications.waset.org/abstracts/132303/vibration-absorption-strategy-for-multi-frequency-excitation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/132303.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">157</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">3987</span> Mixed Frequency Excitation of an Electrostatically Actuated Resonator </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abdallah%20H.%20Ramini">Abdallah H. Ramini</a>, <a href="https://publications.waset.org/abstracts/search?q=Alwathiqbellah%20I.%20Ibrahim"> Alwathiqbellah I. Ibrahim</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20I.%20Younis"> Mohammad I. Younis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We investigate experimentally and theoretically the dynamics of a capacitive resonator under mixed frequency excitation of two AC harmonic signals. The resonator is composed of a proof mass suspended by two cantilever beams. Experimental measurements are conducted using a laser Doppler Vibrometer to reveal the interesting dynamics of the system when subjected to two-source excitation. A nonlinear single-degree-of-freedom model is used for the theoretical investigation. The results reveal combination resonances of additive and subtractive type, which are shown to be promising to increase the bandwidth of the resonator near primary resonance frequency. Our results also demonstrate the ability to shift the combination resonances to much lower or much higher frequency ranges. We also demonstrate the dynamic pull-in instability under mixed frequency excitation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=electrostatically%20actuated%20resonator" title="electrostatically actuated resonator">electrostatically actuated resonator</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-frequency%20excitation" title=" multi-frequency excitation"> multi-frequency excitation</a>, <a href="https://publications.waset.org/abstracts/search?q=nonlinear%20dynamics" title=" nonlinear dynamics"> nonlinear dynamics</a>, <a href="https://publications.waset.org/abstracts/search?q=AC%20harmonic%20signals" title=" AC harmonic signals"> AC harmonic signals</a> </p> <a href="https://publications.waset.org/abstracts/22118/mixed-frequency-excitation-of-an-electrostatically-actuated-resonator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22118.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">622</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">3986</span> A Robust Frequency Offset Estimator for Orthogonal Frequency Division Multiplexing</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> We address the integer frequency offset (IFO) estimation under the influence of the timing offset (TO) in orthogonal frequency division multiplexing (OFDM) systems. Incorporating the IFO and TO into the symbol set used to represent the received OFDM symbol, we investigate the influence of the TO on the IFO, and then, propose a combining method between two consecutive OFDM correlations, reducing the influence. The proposed scheme has almost the same complexity as that of the conventional schemes, whereas it does not need the TO knowledge contrary to the conventional schemes. From numerical results it is confirmed that the proposed scheme is insensitive to the TO, consequently, yielding an improvement of the IFO estimation performance over the conventional schemes when the TO exists. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=estimation" title="estimation">estimation</a>, <a href="https://publications.waset.org/abstracts/search?q=integer%20frequency%20offset" title=" integer frequency offset"> integer frequency offset</a>, <a href="https://publications.waset.org/abstracts/search?q=OFDM" title=" OFDM"> OFDM</a>, <a href="https://publications.waset.org/abstracts/search?q=timing%20offset" title=" timing offset"> timing offset</a> </p> <a href="https://publications.waset.org/abstracts/23340/a-robust-frequency-offset-estimator-for-orthogonal-frequency-division-multiplexing" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/23340.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">474</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">3985</span> Investigation of the Unbiased Characteristic of Doppler Frequency to Different Antenna Array Geometries</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Somayeh%20Komeylian">Somayeh Komeylian</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Array signal processing techniques have been recently developing in a variety application of the performance enhancement of receivers by refraining the power of jamming and interference signals. In this scenario, biases induced to the antenna array receiver degrade significantly the accurate estimation of the carrier phase. Owing to the integration of frequency becomes the carrier phase, we have obtained the unbiased doppler frequency for the high precision estimation of carrier phase. The unbiased characteristic of Doppler frequency to the power jamming and the other interference signals allows achieving the highly accurate estimation of phase carrier. In this study, we have rigorously investigated the unbiased characteristic of Doppler frequency to the variation of the antenna array geometries. The simulation results have efficiently verified that the Doppler frequency remains also unbiased and accurate to the variation of antenna array geometries. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=array%20signal%20processing" title="array signal processing">array signal processing</a>, <a href="https://publications.waset.org/abstracts/search?q=unbiased%20doppler%20frequency" title=" unbiased doppler frequency"> unbiased doppler frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=GNSS" title=" GNSS"> GNSS</a>, <a href="https://publications.waset.org/abstracts/search?q=carrier%20phase" title=" carrier phase"> carrier phase</a>, <a href="https://publications.waset.org/abstracts/search?q=and%20slowly%20fluctuating%20point%20target" title=" and slowly fluctuating point target"> and slowly fluctuating point target</a> </p> <a href="https://publications.waset.org/abstracts/129148/investigation-of-the-unbiased-characteristic-of-doppler-frequency-to-different-antenna-array-geometries" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/129148.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">159</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">3984</span> Multi-Band Frequency Conversion Scheme with Multi-Phase Shift Based on Optical Frequency Comb</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tao%20Lin">Tao Lin</a>, <a href="https://publications.waset.org/abstracts/search?q=Shanghong%20Zhao"> Shanghong Zhao</a>, <a href="https://publications.waset.org/abstracts/search?q=Yufu%20Yin"> Yufu Yin</a>, <a href="https://publications.waset.org/abstracts/search?q=Zihang%20Zhu"> Zihang Zhu</a>, <a href="https://publications.waset.org/abstracts/search?q=Wei%20Jiang"> Wei Jiang</a>, <a href="https://publications.waset.org/abstracts/search?q=Xuan%20Li"> Xuan Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Qiurong%20Zheng"> Qiurong Zheng</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A simple operated, stable and compact multi-band frequency conversion and multi-phase shift is proposed to satisfy the demands of multi-band communication and radar phase array system. The dual polarization quadrature phase shift keying (DP-QPSK) modulator is employed to support the LO sideband and the optical frequency comb simultaneously. Meanwhile, the fiber is also used to introduce different phase shifts to different sidebands. The simulation result shows that by controlling the DC bias voltages and a C band microwave signal with frequency of 4.5 GHz can be simultaneously converted into other signals that cover from C band to K band with multiple phases. It also verifies that the multi-band and multi-phase frequency conversion system can be stably performed based on current manufacturing art and can well cope with the DC drifting. It should be noted that the phase shift of the converted signal also partly depends of the length of the optical fiber. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microwave%20photonics" title="microwave photonics">microwave photonics</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-band%20frequency%20conversion" title=" multi-band frequency conversion"> multi-band frequency conversion</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-phase%20shift" title=" multi-phase shift"> multi-phase shift</a>, <a href="https://publications.waset.org/abstracts/search?q=conversion%20efficiency" title=" conversion efficiency"> conversion efficiency</a> </p> <a href="https://publications.waset.org/abstracts/96199/multi-band-frequency-conversion-scheme-with-multi-phase-shift-based-on-optical-frequency-comb" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/96199.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">254</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">3983</span> Design of a Phemt Buffer Amplifier in Mm-Wave Band around 60 GHz</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Maryam%20Abata">Maryam Abata</a>, <a href="https://publications.waset.org/abstracts/search?q=Moulhime%20El%20Bekkali"> Moulhime El Bekkali</a>, <a href="https://publications.waset.org/abstracts/search?q=Said%20Mazer"> Said Mazer</a>, <a href="https://publications.waset.org/abstracts/search?q=Catherine%20Algani"> Catherine Algani</a>, <a href="https://publications.waset.org/abstracts/search?q=Mahmoud%20Mehdi"> Mahmoud Mehdi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> One major problem of most electronic systems operating in the millimeter wave band is the signal generation with a high purity and a stable carrier frequency. This problem is overcome by using the combination of a signal with a low frequency local oscillator (LO) and several stages of frequency multipliers. The use of these frequency multipliers to create millimeter-wave signals is an attractive alternative to direct generation signal. Therefore, the isolation problem of the local oscillator from the other stages is always present, which leads to have various mechanisms that can disturb the oscillator performance, thus a buffer amplifier is often included in oscillator outputs. In this paper, we present the study and design of a buffer amplifier in the mm-wave band using a 0.15μm pHEMT from UMS foundry. This amplifier will be used as a part of a frequency quadrupler at 60 GHz. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mm-wave%20band" title="Mm-wave band">Mm-wave band</a>, <a href="https://publications.waset.org/abstracts/search?q=local%20oscillator" title=" local oscillator"> local oscillator</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20quadrupler" title=" frequency quadrupler"> frequency quadrupler</a>, <a href="https://publications.waset.org/abstracts/search?q=buffer%20amplifier" title=" buffer amplifier"> buffer amplifier</a> </p> <a href="https://publications.waset.org/abstracts/26079/design-of-a-phemt-buffer-amplifier-in-mm-wave-band-around-60-ghz" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/26079.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">545</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">3982</span> A New IFO Estimation Scheme for Orthogonal Frequency Division Multiplexing Systems</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> We address a new integer frequency offset (IFO) estimation scheme with an aid of a pilot for orthogonal frequency division multiplexing systems. After correlating each continual pilot with a predetermined scattered pilot, the correlation value is again correlated to alleviate the influence of the timing offset. From numerical results, it is demonstrated that the influence of the timing offset on the IFO estimation is significantly decreased. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=estimation" title="estimation">estimation</a>, <a href="https://publications.waset.org/abstracts/search?q=integer%20frequency%20offset" title=" integer frequency offset"> integer frequency offset</a>, <a href="https://publications.waset.org/abstracts/search?q=OFDM" title=" OFDM"> OFDM</a>, <a href="https://publications.waset.org/abstracts/search?q=timing%20offset" title=" timing offset"> timing offset</a> </p> <a href="https://publications.waset.org/abstracts/22778/a-new-ifo-estimation-scheme-for-orthogonal-frequency-division-multiplexing-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22778.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">568</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">3981</span> Experimental Investigation of Natural Frequency and Forced Vibration of Euler-Bernoulli Beam under Displacement of Concentrated Mass and Load</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Aref%20Aasi">Aref Aasi</a>, <a href="https://publications.waset.org/abstracts/search?q=Sadegh%20Mehdi%20Aghaei"> Sadegh Mehdi Aghaei</a>, <a href="https://publications.waset.org/abstracts/search?q=Balaji%20Panchapakesan"> Balaji Panchapakesan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This work aims to evaluate the free and forced vibration of a beam with two end joints subjected to a concentrated moving mass and a load using the Euler-Bernoulli method. The natural frequency is calculated for different locations of the concentrated mass and load on the beam. The analytical results are verified by the experimental data. The variations of natural frequency as a function of the location of the mass, the effect of the forced frequency on the vibrational amplitude, and the displacement amplitude versus time are investigated. It is discovered that as the concentrated mass moves toward the center of the beam, the natural frequency of the beam and the relative error between experimental and analytical data decreases. There is a close resemblance between analytical data and experimental observations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Euler-Bernoulli%20beam" title="Euler-Bernoulli beam">Euler-Bernoulli beam</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=forced%20vibration" title=" forced vibration"> forced vibration</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental%20setup" title=" experimental setup"> experimental setup</a> </p> <a href="https://publications.waset.org/abstracts/144338/experimental-investigation-of-natural-frequency-and-forced-vibration-of-euler-bernoulli-beam-under-displacement-of-concentrated-mass-and-load" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/144338.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">274</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">3980</span> Analysis of Pollution Caused by the Animal Feed Industry and the Fertilizer Industry Using Rock Magnetic Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kharina%20Budiman">Kharina Budiman</a>, <a href="https://publications.waset.org/abstracts/search?q=Adinda%20Syifa%20Azhari"> Adinda Syifa Azhari</a>, <a href="https://publications.waset.org/abstracts/search?q=Eleonora%20Agustine"> Eleonora Agustine</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Industrial activities get increase in this globalization era, one of the major impacts of industrial activities is a problem to the environment. This can happen because at the industrial production term will bring out pollutant in the shape of solid, liquid or gas. Normally this pollutant came from some dangerous materials for environment. However not every industry produces the same amount of pollutant, every industry produces different kind of pollution. To compare the pollution impact of industrial activities, soil sample has been taken around the animal feed industry and the fertilizer industry. This study applied the rock magnetic method and used Bartington MS2B to measured magnetic susceptibility (χ) as the physical parameter. This study tested soil samples using the value of susceptibility low frequency (χ lf) and Frequency Dependent (χ FD). Samples only taken in the soil surface with 0-5 cm depth and sampling interval was 20 cm. The animal feed factory has susceptibility low frequency (χ lf) = 111,9 – 325,7 and Frequency Dependent (χ FD) = 0,8 – 3,57 %. And the fertilizer factory has susceptibility low frequency (χ lf) = 187,1 – 494,8 and Frequency Dependent (χ FD) = 1,37 – 2,46 %. Based on the results, the highest value of susceptibility low frequency (χ lf) is the fertilizer factory, but the highest value of Frequency Dependent (FD) is the animal feed factory. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=industrial" title="industrial">industrial</a>, <a href="https://publications.waset.org/abstracts/search?q=pollution" title=" pollution"> pollution</a>, <a href="https://publications.waset.org/abstracts/search?q=magnetic%20susceptibility" title=" magnetic susceptibility"> magnetic susceptibility</a>, <a href="https://publications.waset.org/abstracts/search?q=%CF%87lf" title=" χlf"> χlf</a>, <a href="https://publications.waset.org/abstracts/search?q=%CF%87fd" title=" χfd"> χfd</a>, <a href="https://publications.waset.org/abstracts/search?q=animal%20feed%20industry%20and%20fertilizer%20industry" title=" animal feed industry and fertilizer industry"> animal feed industry and fertilizer industry</a> </p> <a href="https://publications.waset.org/abstracts/65665/analysis-of-pollution-caused-by-the-animal-feed-industry-and-the-fertilizer-industry-using-rock-magnetic-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/65665.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">403</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">3979</span> Field Experience with Sweep Frequency Response Analysis for Power Transformer Diagnosis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ambuj%20Kumar">Ambuj Kumar</a>, <a href="https://publications.waset.org/abstracts/search?q=Sunil%20Kumar%20Singh"> Sunil Kumar Singh</a>, <a href="https://publications.waset.org/abstracts/search?q=Shrikant%20Singh"> Shrikant Singh</a>, <a href="https://publications.waset.org/abstracts/search?q=Zakir%20Husain"> Zakir Husain</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20K.%20Jarial"> R. K. Jarial</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Sweep frequency response analysis has been turning out a powerful tool for investigation of mechanical as well as electrical integration of transformers. In this paper various aspect of practical application of SFRA has been studied. Open circuit and short circuit measurement were done on different phases of high voltage and low voltage winding. A case study was presented for the transformer of rating 31.5 MVA for various frequency ranges. A clear picture was presented for sub- frequency ranges for HV as well as LV winding. The main motive of work is to investigate high voltage short circuit response. The theoretical concept about SFRA responses is validated with expert system software results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=transformer%20winding" title="transformer winding">transformer winding</a>, <a href="https://publications.waset.org/abstracts/search?q=SFRA" title=" SFRA"> SFRA</a>, <a href="https://publications.waset.org/abstracts/search?q=OCT%20%26%20SCT" title=" OCT & SCT"> OCT & SCT</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20deviation" title=" frequency deviation"> frequency deviation</a> </p> <a href="https://publications.waset.org/abstracts/27973/field-experience-with-sweep-frequency-response-analysis-for-power-transformer-diagnosis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/27973.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">957</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">3978</span> Long-Baseline Single-epoch RTK Positioning Method Based on BDS-3 and Galileo Penta-Frequency Ionosphere-Reduced Combinations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Liwei%20Liu">Liwei Liu</a>, <a href="https://publications.waset.org/abstracts/search?q=Shuguo%20Pan"> Shuguo Pan</a>, <a href="https://publications.waset.org/abstracts/search?q=Wang%20Gao"> Wang Gao</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to take full advantages of the BDS-3 penta-frequency signals in the long-baseline RTK positioning, a long-baseline RTK positioning method based on the BDS-3 penta-frequency ionospheric-reduced (IR) combinations is proposed. First, the low noise and weak ionospheric delay characteristics of the multi-frequency combined observations of BDS-3is analyzed. Second, the multi-frequency extra-wide-lane (EWL)/ wide-lane (WL) combinations with long-wavelengths are constructed. Third, the fixed IR EWL combinations are used to constrain the IR WL, then constrain narrow-lane (NL)ambiguityies and start multi-epoch filtering. There is no need to consider the influence of ionospheric parameters in the third step. Compared with the estimated ionospheric model, the proposed method reduces the number of parameters by half, so it is suitable for the use of multi-frequency and multi-system real-time RTK. The results using real data show that the stepwise fixed model of the IR EWL/WL/NL combinations can realize long-baseline instantaneous cimeter-level positioning. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=penta-frequency" title="penta-frequency">penta-frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=ionospheric-reduced%20%28IR%29" title=" ionospheric-reduced (IR)"> ionospheric-reduced (IR)</a>, <a href="https://publications.waset.org/abstracts/search?q=RTK%20positioning" title=" RTK positioning"> RTK positioning</a>, <a href="https://publications.waset.org/abstracts/search?q=long-baseline" title=" long-baseline"> long-baseline</a> </p> <a href="https://publications.waset.org/abstracts/145983/long-baseline-single-epoch-rtk-positioning-method-based-on-bds-3-and-galileo-penta-frequency-ionosphere-reduced-combinations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/145983.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">169</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">3977</span> Frequency Identification of Wiener-Hammerstein Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Brouri%20Adil">Brouri Adil</a>, <a href="https://publications.waset.org/abstracts/search?q=Giri%20Fouad"> Giri Fouad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The problem of identifying Wiener-Hammerstein systems is addressed in the presence of two linear subsystems of structure totally unknown. Presently, the nonlinear element is allowed to be noninvertible. The system identification problem is dealt by developing a two-stage frequency identification method such a set of points of the nonlinearity are estimated first. Then, the frequency gains of the two linear subsystems are determined at a number of frequencies. The method involves Fourier series decomposition and only requires periodic excitation signals. All involved estimators are shown to be consistent. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Wiener-Hammerstein%20systems" title="Wiener-Hammerstein systems">Wiener-Hammerstein systems</a>, <a href="https://publications.waset.org/abstracts/search?q=Fourier%20series%20expansions" title=" Fourier series expansions"> Fourier series expansions</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20identification" title=" frequency identification"> frequency identification</a>, <a href="https://publications.waset.org/abstracts/search?q=automation%20science" title=" automation science"> automation science</a> </p> <a href="https://publications.waset.org/abstracts/7941/frequency-identification-of-wiener-hammerstein-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7941.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">536</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">3976</span> Static Priority Approach to Under-Frequency Based Load Shedding Scheme in Islanded Industrial Networks: Using the Case Study of Fatima Fertilizer Company Ltd - FFL</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20H.%20Kazmi">S. H. Kazmi</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20Ahmed"> T. Ahmed</a>, <a href="https://publications.waset.org/abstracts/search?q=K.%20Javed"> K. Javed</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Ghani"> A. Ghani </a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper static scheme of under-frequency based load shedding is considered for chemical and petrochemical industries with islanded distribution networks relying heavily on the primary commodity to ensure minimum production loss, plant downtime or critical equipment shutdown. A simplistic methodology is proposed for in-house implementation of this scheme using underfrequency relays and a step by step guide is provided including the techniques to calculate maximum percentage overloads, frequency decay rates, time based frequency response and frequency based time response of the system. Case study of FFL electrical system is utilized, presenting the actual system parameters and employed load shedding settings following the similar series of steps. The arbitrary settings are then verified for worst overload conditions (loss of a generation source in this case) and comprehensive system response is then investigated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=islanding" title="islanding">islanding</a>, <a href="https://publications.waset.org/abstracts/search?q=under-frequency%20load%20shedding" title=" under-frequency load shedding"> under-frequency load shedding</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20rate%20of%20change" title=" frequency rate of change"> frequency rate of change</a>, <a href="https://publications.waset.org/abstracts/search?q=static%20UFLS" title=" static UFLS"> static UFLS</a> </p> <a href="https://publications.waset.org/abstracts/25160/static-priority-approach-to-under-frequency-based-load-shedding-scheme-in-islanded-industrial-networks-using-the-case-study-of-fatima-fertilizer-company-ltd-ffl" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/25160.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">486</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=4">4</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=5">5</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=6">6</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=7">7</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=8">8</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=9">9</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=10">10</a></li> <li class="page-item disabled"><span class="page-link">...</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=133">133</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=134">134</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=very%20low%20frequency&page=2" rel="next">&rsaquo;</a></li> </ul> </div> </main> <footer> <div id="infolinks" class="pt-3 pb-2"> <div class="container"> <div style="background-color:#f5f5f5;" class="p-3"> <div class="row"> <div class="col-md-2"> <ul class="list-unstyled"> About <li><a href="https://waset.org/page/support">About Us</a></li> <li><a href="https://waset.org/page/support#legal-information">Legal</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/WASET-16th-foundational-anniversary.pdf">WASET celebrates its 16th foundational anniversary</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Account <li><a href="https://waset.org/profile">My Account</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Explore <li><a href="https://waset.org/disciplines">Disciplines</a></li> <li><a href="https://waset.org/conferences">Conferences</a></li> <li><a href="https://waset.org/conference-programs">Conference Program</a></li> <li><a href="https://waset.org/committees">Committees</a></li> <li><a href="https://publications.waset.org">Publications</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Research <li><a href="https://publications.waset.org/abstracts">Abstracts</a></li> <li><a href="https://publications.waset.org">Periodicals</a></li> <li><a href="https://publications.waset.org/archive">Archive</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Open Science <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Philosophy.pdf">Open Science Philosophy</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Award.pdf">Open Science Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Society-Open-Science-and-Open-Innovation.pdf">Open Innovation</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Postdoctoral-Fellowship-Award.pdf">Postdoctoral Fellowship Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Scholarly-Research-Review.pdf">Scholarly Research Review</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Support <li><a href="https://waset.org/page/support">Support</a></li> <li><a href="https://waset.org/profile/messages/create">Contact Us</a></li> <li><a href="https://waset.org/profile/messages/create">Report Abuse</a></li> </ul> </div> </div> </div> </div> </div> <div class="container text-center"> <hr style="margin-top:0;margin-bottom:.3rem;"> <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" class="text-muted small">Creative Commons Attribution 4.0 International License</a> <div id="copy" class="mt-2">© 2024 World Academy of Science, Engineering and Technology</div> </div> </footer> <a href="javascript:" id="return-to-top"><i class="fas fa-arrow-up"></i></a> <div class="modal" id="modal-template"> <div class="modal-dialog"> <div class="modal-content"> <div class="row m-0 mt-1"> <div class="col-md-12"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> </div> </div> <div class="modal-body"></div> </div> </div> </div> <script src="https://cdn.waset.org/static/plugins/jquery-3.3.1.min.js"></script> <script src="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/js/bootstrap.bundle.min.js"></script> <script src="https://cdn.waset.org/static/js/site.js?v=150220211556"></script> <script> jQuery(document).ready(function() { /*jQuery.get("https://publications.waset.org/xhr/user-menu", function (response) { jQuery('#mainNavMenu').append(response); });*/ jQuery.get({ url: "https://publications.waset.org/xhr/user-menu", cache: false }).then(function(response){ jQuery('#mainNavMenu').append(response); }); }); </script> </body> </html>