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Recursive estimation of frequencies and frequency rates of multiple cisoids in noise

SIGNAL PROCESSING 1997年第2期58卷 117-129页

作者： Tichavsky, P Handel, P Institute of Information Theory and Automation Academy of Sciences of the Czech Republic P.O. Box 18 182 08 Prague Czech Republic Signal Processing Laboratory Tampere University of Technology P. O. Box 553 FIN-33101 Tampere Finland

A recursive algorithm for simultaneous estimation and tracking of instantaneous frequencies and instantaneous frequency rates-of-change for signals that consist of multiple narrow-band components in noise is proposed and studied. The algorithm recursively separates the signal to individual components and uses estimated phase differences for updating the instantaneous frequency and frequency rate of each component. The main advantages of the proposed algorithm over frequencies-only tracking algorithms known in literature include the zero asymptotic bias (zero tracking delay) in estimating of the instantaneous frequencies of linear FM (chirp) signals and more accurate tracking of frequencies that cross each other. Performance of the algorithm is studied by means of a linear filter approximation technique and derived results are compared with the appropriate (posterior) Cramer-Rao bound. Superior performance of the algorithm is illustrated by computer simulations. (C) 1997 Elsevier Science B.V.

关键词： sinusoidal frequency estimation tracking algorithm frequency rate linear FM signal chirp posterior Cramer-Rao bound

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A Dynamic WPT System With High Efficiency and High Power Factor for Electric Vehicles

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2020年第7期35卷 6732-6740页

作者： Zakerian, Ali Vaez-Zadeh, Sadegh Babaki, Amir Univ Tehran Sch Elect & Comp Engn Coll Engn Tehran *** Iran Univ Tehran Adv Mot Syst Res Lab Tehran *** Iran Univ Tehran Ctr Excellence Appl Electromagnet Syst Sch Elect & Comp Engn Coll Engn Tehran *** Iran

Dynamic wireless power transfer (WPT) for charging electric vehicles (EVs) overcomes some of the problems associated with EVs battery size and weight as well as distance range limitation and long charging duration. High efficiency and fixed output voltage of WPT systems are of great importance for reducing operating cost and facilitating battery charging, respectively. On the other hand, utilizing the maximum power transfer capability of a WPT system leads to a capital cost saving of the system. In this article, the product of transferred power efficiency and input power factor (eta center dot PF) is regarded as a criterion to make near full usage of the system power transfer capacity as well as reduce the capital and operating cost of the system. An optimal frequency-tracking method is proposed to maximize eta center dot PF of the system taking into account possible abrupt changes in the coupling coefficient of the WPT system due to deviations of EV from alignment with the track along the road. In addition, the output voltage of the system is regulated simultaneously by an on-line adjustment of the primary inverter duty ratio. The optimal frequency-tracking method and voltage regulation are validated by extensive simulation and experimental results.

关键词： Dynamic charging efficiency electric vehicles (EVs) power factor tracking algorithm wireless power transfer (WPT)

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DESIGN OF POWER-SYSTEM STABILIZERS USING REDUCED-ORDER MODELS

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ELECTRIC POWER SYSTEMS RESEARCH 1995年第3期33卷 219-226页

作者： SALEH, FA MAHMOUD, MS Computer Center Kuwait University PO Box 5969 Safat 13060 Kuwait Department of Electrical and Computer Engineering Kuwait University PO Box 5969 Safat 13060 Kuwait

This paper provides design methods of power system stabilizers using full- and reduced-order models. The methods are based on linear quadratic optimal tracking as well as observer based feedback control. Application to a model representing a single-machine infinite-bus power system has been undertaken and the results obtained show the effectiveness of the design methods.

关键词： POWER SYSTEM STABILIZERS CONTROL STRATEGIES OPTIMAL CONTROLLERS REDUCED-ORDER MODELS tracking algorithm

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Vitreous deformation during eye movement

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NMR IN BIOMEDICINE 2012年第1期25卷 59-66页

作者： Piccirelli, Marco Bergamin, Oliver Landau, Klara Boesiger, Peter Luechinger, Roger Univ Spital Zurich SNS Lab Dept Ophthalmol CH-8091 Zurich Switzerland Univ Zurich Branco Weiss Lab Social & Neural Syst Res Zurich Switzerland Univ Zurich Inst Biomed Engn Zurich Switzerland Swiss Fed Inst Technol Zurich Switzerland

Retinal detachment results in visual loss and requires surgical treatment. The risk of retinal detachment depends, among other factors, on the vitreous rheology, which varies with age. To date, the viscoelasticity of the vitreous body has only been measured in cadaver eyes. However, the ex vivo and in vivo viscoelasticity may differ as a result of the effect of intravitreal membranes. Therefore, an MRI method and appropriate postprocessing tools were developed to determine the vitreous deformation and viscoelastic properties in the eyes of living humans. Nineteen subjects (eight women and 11 men;mean age, 33years;age range, 14-62years) gazed at a horizontal sinusoidal moving target during the segmented acquisition of complementary spatial modulation of magnetization images. The center of the lens and the scleral insertion of the optic nerve defined the imaging plane. The vitreous deformation was tracked with a dedicated algorithm and fitted with the commonly used viscoelastic model to determine the model parameters: the modified Womersley number a and the phase angle b. The vitreous deformation was successfully quantified in all 17 volunteers having a monophasic vitreous. The mean and standard deviation of the model parameters were determined to be 5.5 +/- 1.3 for a and -2.3 +/- 0.2 for b. The correlation coefficient (-0.76) between a and b was significant. At the eye movement frequency used, the mean storage and loss moduli of the vitreous were around 3 +/- 1hPa. For two subjects, the vitreous deformation was clearly polyphasic: some compartments of the vitreous were gel-like and others were liquefied. The borders of these compartments corresponded to reported intravitreal membrane patterns. Thus, the deformation of the vitreous can now be determined in situ, leaving the structure of the intravitreal membranes intact. Their effect on vitreous dynamics challenges actual vitreous viscoelastic models. The determination of the vitreous deformation will aid in the quant

关键词： tagging tracking algorithm vitreous viscosity elasticity retinal detachment

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Automatic Lighting System Using Multiple Robotic Lamps

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IEEE-ASME TRANSACTIONS ON MECHATRONICS 2014年第3期19卷 963-974页

作者： Yoon, Dae-Keun Seo, Jong-Tae Jung, Eui-Jung Yi, Byung-Ju Hanyang Univ Dept Elect Syst Engn Ansan 426791 South Korea

An automatic lighting system using 3-DOF robotic lamps and a laser scanner is proposed in this paper. The 3-DOF robotic lamp, which is designed with a spherical parallel mechanism with a unique forward kinematic solution, has a tilting motion to track a person and zoom-in and zoom-out motions to control the light intensity. In order to minimize the dynamic load, three actuators are installed at the base frame, and a counterbalancing design is considered. The positions of people are detected by a laser scanner, and the Kalman filter and a data association algorithm are applied in order to track the positions of people accurately. Therefore, multiple robotic lamps can track and illuminate each person continuously. We demonstrate experimentally that three robotic lamps mounted on the ceiling illuminate three people independently and control the intensity of the light according to the distance between a person and the robotic lamp.

关键词： Mechanism design robotic lamp spherical parallel mechanism tracking algorithm

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Characteristic Changes in the Strengthening Western Disturbances over Karakoram in Recent Decades

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ASIA-PACIFIC JOURNAL OF ATMOSPHERIC SCIENCES 2024年第3期60卷 255-270页

作者： Javed, Aaquib Kumar, Pankaj Indian Inst Sci Educ & Res Bhopal Dept Earth & Environm Sci Bhopal Bypass Rd Bhopal 462066 India

Western disturbances (WDs) are upper-tropospheric mid-latitude synoptic systems propagating eastward along the subtropical westerly jet stream. They are capable of causing extreme precipitation events and have strengthened their impact over the Karakoram part of the Himalayas in recent decades. They play a crucial role in the sustenance of the "Karakoram Anomaly," which refers to the anomalous stability/surge of a few Karakoram glaciers in contrast to the other glaciers of the Himalayas. Using the existing WD-catalog derived from ERA5 and MERRA2 reanalysis datasets, we observed that the core genesis zone for Karakoram WDs had undergone a statistically significant shift of similar to 9.7 degrees E, migrating towards more favourable conditions for cyclogenesis. The study proposes a new parameter to identify regions of potential extratropical cyclogenesis. The shift can be attributed to an enhanced genesis potential, convergence, and higher moisture availability along the WD path. Composite analysis suggests that moisture availability has risen significantly over the shifted zone. Moreover, the propagation speeds of these systems have significantly declined, which explains the recent intensification of precipitation events related to WDs over the Karakoram and hints toward a crucial synoptic influence on the anomalous regional mass-balance phenomenon.

关键词： Western disturbances Karakoram anomaly Climate change tracking algorithm

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Image-based measurement of alveoli volume expansion in an animal model of a diseased lung

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INTERNATIONAL JOURNAL OF COMPUTER APPLICATIONS IN TECHNOLOGY 2010年第1-3期39卷 58-65页

作者： Hann, Christopher E. Hewett, Darren Chase, J. Geoffrey Rabczuk, Timon Sundaresan, Ashwath Chen, XiaoQi Wang, Wenhui Univ Canterbury Dept Mech Engn Christchurch New Zealand

This research aims to improve ventilation protocols in critical care by using appropriate computer models that take into account the essential lung mechanics. This paper automatically tracks the boundary of individual or groups of alveoli, and converts this into a pressure volume curve for three different types of alveoli. Schiller et al. investigate the inflation and deflation of alveoli in a surfactant deactivation model of lung injury in pigs. Three different types of alveoli were tracked using dynamic ventilation data from Schiller et al. The boundaries of all the tracked alveoli compared well visually to the movies. Pressure versus area curves were derived for both inflation and deflation, they captured the expected physiological behaviour, and were qualitatively similar to the quasi-static pressure area curves derived by Schiller et al. Quantitative differences are due to the dynamic effects of ventilation which were not investigated by Schiller et al.

关键词： mechanical ventilation critical care computer models alveoli tracking algorithm

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A new track fitting algorithm dedicated for handling non-Gaussian detector effects using flexible and parameterized models

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2020年 978卷 164446-164446页

作者： Chou, Hsin-Yi Chang, Yuan-Hann Li, Han-Sheng Yang, Yi Natl Cent Univ Phys Dept Taoyuan 32054 Taiwan Natl Cent Univ Ctr High Energy & High Field Taoyuan 32054 Taiwan Acad Sinica Inst Phys Taipei 11529 Taiwan Natl Cheng Kung Univ Dept Phys Tainan 70101 Taiwan

We present a new track fitting algorithm for high energy physics experiments dedicated for handling the non-Gaussian detector effects. It uses a comprehensive propagation model to predict the particle trajectory, as well as flexible and parameterized models (FPM method) to describe the contributions from multiple scattering, to estimate of the positions of hits, and to calculate the energy losses. The track fitting algorithm with the FPM method then minimizes a global non-linear chi-square function to obtain the full information of a track.

关键词： tracking algorithm Non-Gaussian detector effect Flexible model Parameterized model Multiple scattering Energy loss

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The decline in western disturbance activity over Northern India in recent decades

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CLIMATIC CHANGE 2023年第7期176卷 1-22页

作者： Javed, Aaquib Anshuman, Katyan Kumar, Pankaj Sachan, Disha Indian Inst Sci Educ & Res Bhopal Dept Earth & Environm Sci Bhopal By Pass Rd Bhopal 462066 India

Western disturbances (WDs) are upper-tropospheric synoptic-scale cyclonic storms that travel eastwards embedded in the subtropical westerly jet stream. They are of veritable significance to the sustenance of the population in the north and northwest regions of the Indian subcontinent and are often harbingers of extreme precipitation events during the boreal winter. This study utilizes a tracking algorithm with the upper-level vorticity field of the ERA5 reanalysis product to catalog events over the northern part of the Indian subcontinent for 39 WD seasons (Nov-Mar;1980-2019), including information about their trajectory and precipitation. The contribution of WDs to the region's total precipitation has been quantified comprehensively, enabling the proposition of a "core WD zone" and an intensity categorization of WDs affecting India. The core zone exhibits a decreasing trend for annual WD-associated precipitation despite the frequency of storms depicting no evident trend. The combined mean frequency of strong and extreme WDs declined by as much as similar to 43%, contrary to the mean occurrences of feeble and moderate WDs, which rose by similar to 11%. However, the mean seasonal precipitation volume decreased for all the categories, irrespective of the changes in their frequencies. The sharpest decline (similar to 49%) was observed for the most intense WDs (strong and extreme), primarily explaining the decreasing WD precipitation intensity across the core WD zone. The spatial distribution and evolution of various dynamical parameters reveal an inhibitive dynamic state of the atmosphere restricting the moisture advection capacity of WDs and the resultant decline in the associated precipitation over the core WD zone in recent decades.

关键词： Western disturbances Climate change tracking algorithm

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Critical Review on PV MPPT Techniques: Classical, Intelligent and Optimisation

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IET RENEWABLE POWER GENERATION 2020年第9期14卷 1433-1452页

作者： Bollipo, Ratnakar Babu Mikkili, Suresh Bonthagorla, Praveen Kumar Natl Inst Technol Goa Elect & Elect Engn Farmagudi Goa India

Maximum power extraction from the photovoltaic (PV) system plays a critical role in increasing efficiency during partial shading conditions (PSC's). The higher cost and low conversion efficiency of the PV panel necessitate the extraction of the maximum power point (MPP). So, a suitable maximum power point tracking (MPPT) technique to track the MPP is of high need, even under PSC's. This study gives an extensive review of 23 MPPT techniques present in literature along with recent publications on various hardware design methodologies. MPPT classification is done into three categories, i.e. Classical, Intelligent and Optimisation depending on the tracking algorithm utilised. During uniform insolation, classical methods are highly preferred as there is only one peak in theP-Vcurve. However, under PSC's, theP-Vcurve exhibits multiple peaks, one global MPP (GMPP) and the remaining are local MPPs. Hence, Intelligent and Optimisation techniques came into limelight to differentiate the GMPP out of all LMPPs. Every MPPT technique has its advantages and limits, but a streamlined MPPT is drafted in numerous parameters like sensors required, hardware implementation, tracking in PSC's, cost, tracking speed and tracking efficiency. This present study aimed to address the advancement in this area for further research.

关键词： photovoltaic power systems maximum power point trackers solar cell arrays optimisation PV MPPT techniques intelligent optimisation maximum power extraction photovoltaic system solar power generation partial shading conditions conversion efficiency solar PV panel PV system maximum power point tracking technique hardware design methodologies tracking algorithm PSC global MPP tracking efficiency GMPP P-V curve cost viability

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