Polarimetric decompostion based on partcle swarm optimization and its data analysis

This paper deals with a polarimetric decomposition considering azimuth rotation based on evolutionary algorithm. Polarimetric data in urban and mountain areas are affected by azimuth rotation. Thus, the decomposition results derived by same target with different azimuth rotation angle are changed. Some researchers examined to compensate this rotation by mathematical inverse rotation. In this report, the differences of covariance matrix before and after the compensation are used to estimate the contributions of three decomposition components. An evolutional algorithm to determine the contributions is a particle swarm optimization (PSO) which is one of the evolutional algorithms. We apply the proposed method to ALOS/PALSAR data and compare the results between four component decomposition method and proposed method

Microwave imaging from total electric field data

A novel gradient-based inverse scattering method for imaging inhomogeneous objects from time-domain data of only total electric field is presented. Unlike most inverse scattering methods, the proposed method does not require the explicit information of the incident field illuminating a region of interest. Numerical simulations demonstrate the effectiveness of the method.2014 IEEE Antennas and Propagation Society International Symposium, APSURSI 2014; Memphis Convention CenterMemphis; United States; 6 July 2014 through 11 July 201

Application of time reversal to imaging electrical properties of inhomogeneous cylindrical objects

A time-domain inverse scattering approach using time-reversed fields for reconstructing electrical parameters of cylindrical objects has been proposed in a previous work. The approach does not require the explicit knowledge of incident fields illuminating the object. The cost functional represented in terms of the time-reversed fields was minimized by a genetic algorithm (GA). In this paper, we propose a gradient-based minimization for reconstruction of an inhomogeneous object for which GA can not be applied due to computational complexity. The time-reversed fields are calculated by time-reversing the equivalent current sources determined by the total fields recorded on a measurement line. Numerical simulations are carried out to show the effectiveness of the proposed method.8th European Conference on Antennas and Propagation, EuCAP 2014; The Hague; Netherlands; 6 April 2014 through 11 April 201

Image reconstruction of objects with time reversal and equivalent fields

Most inversion schemes for reconstructing electrical parameter distributions of unknown objects assume the explicit knowledge of incident fields illuminating them. We have proposed an inversion approach based on the field equivalence principle without requiring the knowledge of incident fields. The approach, however, requires measurement of both electric and magnetic tangential components of total field on the observation surface. In this paper, a new inversion scheme for the reconstruction from measured data of only electric tangential components is presented using time reversal and equivalent fields. Numerical reconstruction examples show the validity of the proposed scheme.2013 15th International Conference on Electromagnetics in Advanced Applications, ICEAA 2013; Turin; Italy; 9 September 2013 through 13 September 201

Pulse Splitting for Harmonic Beamforming in Time-Modulated Linear Arrays

A novel strategy for harmonic beamforming in time-modulated linear arrays is proposed. The pulse splitting technique is exploited to simultaneously generate two harmonic patterns, one at the central frequency and another at a preselected harmonic of arbitrary order, while controlling the maximum level of the remaining sideband radiations. An optimization strategy based on the particle swarm optimizer is developed in order to determine the optimal parameters describing the pulse sequence used to modulate the excitation weights of the array elements. Representative numerical results are reported and discussed to point out potentialities and limitations of the proposed approach

Iterative multiscaling strategy incorporated into time domain inverse scattering method for cross-borehole imaging

We consider cross-borehole imaging of buried objects embedded in a large search area by using a time domain inverse analysis. For simplicity, a two-dimensional model is examined. In order to avoid trap into false solution and enhance the achievable spatial resolution, the iterative multiscaling strategy combined with the forward-backward time-stepping method is proposed. Preliminary results show the effectiveness of proposed method.IGARSS 2011 - 2011 IEEE International Geoscience and Remote Sensing Symposium : Vancouver, BC, Canada, 2011.07.24-2011.07.2

Generaattorin saarekekäyttö ja suojausten testaus

Työn aiheena oli sähkövoimatekniikan laboratorion oppimisympäristön generaattorin saarekekäyttö ja sen suojausten testaus. Opinnäytetyön tavoitteena oli testata ja käyttää generaattoria saarekekäytössä ja tehdä sille kytkentäohjelma, jonka avulla voidaan myöhemmin käyttää generaattoria saarekekäytön opetuk-sessa. Tavoitteena oli tehdä myös generaattorin relesuojauksille toiminnalliset testit. Opinnäytetyön teoriaosuudessa käsiteltiin generaattoreita ja niiden relesuojauksia. Generaattoreissa keskityttiin enemmän tahtigeneraattoreihin, koska opinnäytetyössä käytettiin sellaista. Työssä esiteltiin myös laiteympäristö, johon tätä opinnäytetyötä tehtiin. Opinnäytetyössä käytiin läpi myös ohjelmistot, joita tässä ympäristössä on mahdollista käyttää. Lähdemateriaaleina käytettiin alan kirjallisuutta sekä laitevalmistajien manuaaleja sekä nettisivuja. Työssä asetetut tavoitteet täyttyivät ja tulokseksi saatiin kytkentäohjelma gene-raattorin saarekekäyttöön ja tieto siitä, kuinka sitä kuormitettiin. Myös generaat-torin suojauksien toiminnallisille testeille tehtiin ohjeistus, jonka avulla voidaan tulevaisuudessa tehdä toiminnallisia testejä. Myös REG630- releelle tehtiin ohjeistuksia, joiden avulla sitä voidaan myöhemmin käyttää.The subject of the thesis was electric power engineering laboratory learning environment for testing a generator in island operation and testing its protec-tion. The aim of the thesis was to test and use the generator in island operation and to make a switch program, which can later be used in education of using the generator in island operation. The other aim was to test a generator´s relay protection. The theoretical part of the thesis was concerned with generator´s and their relay protection. The focus was more on a synchronous generators were more focused, because synchronous generator was used in this thesis. The presentation of the thesis section presents a platform, where this thesis was made. Softwares, that are possible to use in this platform, were also presented in this thesis. The source materials were based on the field of the literature, as well as in the manufacturer`s Internet websites and manuals. The aim of the thesis was met and the results were that the switch program for using the generator in island operation was made and how it was loaded. Generator´s protections were also tested and the instructions were made, which helps in doing these tests in the future. Instructions were also made for the REG630 relay. These instructions help to use it

Two-dimensional Forward-Backward Time-Stepping approach for tumor detection in dispersive breast tissues

The Forward-Backward Time-Stepping (FBTS) technique is applied to determine the presence and location of malignant tumor in the heterogeneous breast model. A new strategy is integrated in the FBTS algorithm to accurately estimate the dielectric properties of tissues. We demonstrate 2-D FBTS technique utilizing the numerical dispersive breast model in a free space. This new strategy manipulating Debye dispersion equation is proposed to treat dispersive case. Numerical simulation results show the FBTS algorithm has the potential to provide useful quantitative information of the breast\u27s internal composition.2009 Mediterranean Microwave Symposium (MMS) : Tangiers, Morocco, 2009.11.15-2009.11.1

Microwave breast imaging by the filtered forward-backward time-stepping method

In this paper, an inverse scattering technique referred to as the filtered forward-backward time-stepping method is applied to microwave imaging for breast cancer detection. A two-dimensional numerical breast phantom (derived from MR images) with high contrast between fat and fibroglandular tissues, and low contrast between fibroglandular and tumor tissues are used to assess the efficacy of the proposed method.2010 URSI International Symposium on Electromagnetic Theory (EMTS 2010) : Berlin, Germany, 2010.08.16-2010.08.1