A Hybrid Approach Based on PSO and Hadamard Difference Sets for the Synthesis of Square Thinned Arrays

A hybrid approach for the synthesis of planar thinned antenna arrays is presented. The proposed solution exploits and combines the most attractive features of a particle swarm algorithm and those of a combinatorial method based on the noncyclic difference sets of Hadamard type. Numerical experiments validate the proposed solution, showing improvements with respect to previous results. (c) 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

Detection, Location and Imaging of Multiple Scatterers by means of the Iterative Multiscaling Method

In this paper, a new version of the iterative multiscaling method (IMM) is proposed for reconstructing multiple scatterers in two-dimensional microwave imaging problems. The manuscript describes the new procedure evaluating the effectiveness of the IMM previously assessed for single object detection. Starting from inverse scattering integral equations, the problem is recast in a minimization one by defining iteratively (at each level of the scaling procedure) a suitable cost function allowing firstly a detection of the unknown objects, successively a location of the scatterers and finally a quantitative reconstruction of the scenario under test. Thanks to its properties, the approach allows an effective use of the information achievable from inverse scattering data. Morover, the adopted kind of expansion is able to deal with all possible multiresolution combinations in an easy and computationally inexpensive way. Selected numerical examples concerning dielectric as well as dissipative objects in noisy enviroments or starting from experimantally-acquired data are reported in order to confirm the usefulness of the introduced tool and of the effectiveness of the proposed procedure

Microwave Imaging from Limited-Angle Scattered Data using the Iterative Multi-Scaling Approach

In this paper, with reference to limited-angle data configurations, the performance of the nonlinear multi-scaling inversion approach (IMSA) is analyzed. Such an assessment is carried out by considering synthetically-generated as well as laboratory-controlled experimental data ('Marseille data') concerning two-dimensional dielectric scatterers. The obtained results demonstrate a satisfactory robustness and the reliability of the approach

An Iterative Procedure for Combining the Advantages of a Multi-Frequency and Multi-Resolution Inversion Algorithm

Starting from the iterative multi�]scaling approach previously studied for monochromatic illuminations, two multi�]resolution strategies for dealing with multi�]frequency inverse scattering experiments have been developed. The first procedure is based on the integration of the iterative multi�]scaling algorithm into a frequency�]hopping reconstruction scheme, while in the second one the multi�]frequency data are simultaneously processed exploiting a multi�]resolution expansion of the problem unknowns. The numerical and the experimental analysis presented in this contribution concern with a preliminary assessment of the reconstruction effectiveness of the proposed approaches in comparison with a monochromatic multi�]step process. This is the author's version of the final version available at IEEE

A Planar Electronically Reconfigurable Wi-Fi Band Antenna Based on a Parasitic Microstrip Structure

This report presents the result of the synthesis of an horizontally polarized reconfigurable microstrip antenna

Effects of a trapped vortex cell on thick wing profile

Experimental investigation on the effects originated from a trapped vortex cell on the NACA0024 airfoi

Syrian Refugees in Turkey: A Security Perspective

This study investigates the nexus between the mass movement of people and security and foreign policy behaviors. The assertion is that refugee flows intensify security issues among decision makers and members of society; consequently, new fears and wider perceptions of threats have several implications for foreign policy agenda. The article focuses on the theoretical analysis of the securitization of migration and its impact on foreign policy and security policy. It also analyzes, from a security perspective, the effect on Turkey of the refugees who arrived en masse from Syria during the past six years. The article concludes with an analysis of the social, economic, security, and foreign policy effects the refugees have had on Turkey

Historical Reflection on Neo-Ottoman Weltanschauung: between Identity-making and Foreign Policy

The text is a diachronic presentation of the development of neo-Ottoman ideology in Turkey. After six decades of secular Kemalism that assimilated minorities under a single Turkish identity, Turgot 6zal\u2019s government progressively reintroduced elements of Islam in Turkish public life and revived the 19th-century concept of Ottomanism involving a multi-cultural, multi-lingual and multi-religious state. Islamic spiritual movements contributed to the start of formation of a new Turkish identity with a strong Ottoman Islamic character This process has been continued under the rule of the AKP, a party rooted in Islamic tradition but active in foreign policy. According to the party theoretician Ahmed Davuto\u11flu, the Middle East turmoil results from the destruction of Ottoman cosmopolitanism by the European model of secularism and political nationalism and Turkey can be a pivotal state in the region. The AKP perceives Islam as a key for a new identity that will unify the various domestic ethnic groups and a way to calm regional instability while its current foreign policy carries strong pan-Ottoman undertones

A SVM-Based Multi-Resolution Procedure for the Estimation of the DOAS of Interfering Signals in a Communication System

In this work, the use of a planar antenna system for the estimation of the directions of arrivals (DOAs) of multiple signals impinging on the receiver has been considered. Towards this end, an efficient multi-resolution method based on a SVM-classifier is proposed for determining a probabilitic map of the DOAs of the unknown interfering signals. Numerical results dealing with multiple interferers scenarios in noisy environments are provided in order to assess the feasibility as well as the capability of the proposed approach