Practical localized waves generation

Since the early works on localized waves (LW), extensive results were published on this important subject, from both the theoretical and the experimental points of view. Nevertheless, those experimental techniques of LW generation suffer from several shortcomings. A major one is that only pulse peaks were accredited. Either the full profile of the generated pulse was not reported, or it was not closely matching the theoretical profile. Additionally, low resolutions of the generated LWs were reported in the acoustic X-Waves. The conductors of the experiment attributed this effect to the limited bandwidth of the excitation elements. The interest in the unique features of LWs and their high potential in different applications were the main motivation for conducting this study. Because of the complex nature of LWs, it is challenging to design a system that can launch LWs with high accuracy and power efficiency as well as the flexibility in choosing the LWs design parameters. Due to practical limitations, the results of this research could not yet be experimentally verified; however, this research aims to provide a practically feasible method for LWs generation that avoids the shortcomings of previous techniques. In the study, the transverse electric (TE) version of the MPS pulse is derived. Expansion in terms of the waveguide\u27s orthogonal modes is presented and followed by the method to determine the excitation currents for the loop antennas inside a circular waveguide. The feasibility and flexibility of the method is demonstrated via numerical examples

General Metasurface Synthesis Based on Susceptibility Tensors

A general method, based on susceptibility tensors, is proposed for the synthesis of metasurfaces transforming arbitrary incident waves into arbitrary reflected and transmitted waves. The proposed method exhibits two advantages: 1)it is inherently vectorial, and therefore better suited for full vectorial (beyond paraxial) electromagnetic problems, 2) it provides closed-form solutions, and is therefore extremely fast. Incidentally, the method reveals that a metasurface is fundamentally capable to transform up to four independent wave triplets (incident, reflected and refracted waves). In addition, the paper provides the closed-form expressions relating the synthesized susceptibilities and the scattering parameters simulated within periodic boundary conditions, which allows one to design the scattering particles realizing the desired susceptibilities. The versatility of the method is illustrated by examples of metasurfaces achieving the following transformations: generalized refraction, reciprocal and non-reciprocal polarization rotation, Bessel vortex beam generation, and orbital angular momentum multiplexing

Adversarial inference and manipulation of machine learning models

Machine learning (ML) has established itself as a core component for various critical applications. However, with this increasing adoption rate of ML models, multiple attacks have emerged targeting different stages of the ML pipeline. Abstractly, the ML pipeline is divided into three phases, including training, updating, and inference. In this thesis, we evaluate the privacy, security, and accountability risks of the three stages of the ML pipeline. Firstly, we explore the inference phase, where the adversary can only access the target model after deployment. In this setting, we explore one of the most severe attacks against ML models, namely the membership inference attack (MIA). We relax all the MIA's key assumptions, thereby showing that such attacks are broadly applicable at low cost and thereby pose a more severe risk than previously thought. Secondly, we study the updating phase. To that end, we propose a new attack surface against ML models, i.e., the change in the output of an ML model before and after being updated. We then introduce four attacks, including data reconstruction ones, against this setting. Thirdly, we explore the training phase, where the adversary interferes with the target model's training. In this setting, we propose the model hijacking attack, in which the adversary can hijack the target model to provide their own illegal task. Finally, we propose different defense mechanisms to mitigate such identified risks.Maschinelles Lernen (ML) hat sich als Kernkomponente für verschiedene kritische Anwendungen etabliert. Mit der zunehmenden Verbreitung von ML-Modellen sind jedoch auch zahlreiche Angriffe auf verschiedene Phasen der ML-Pipeline aufgetreten. Abstrakt betrachtet ist die ML-Pipeline in drei Phasen unterteilt, darunter Training, Update und Inferenz. In dieser Arbeit werden die Datenschutz-, Sicherheits- und Verantwortlichkeitsrisiken der drei Phasen der ML-Pipeline bewertet. Zunächst untersuchen wir die Inferenzphase. Insbesondere untersuchen wir einen der schwerwiegendsten Angriffe auf ML-Modelle, nämlich den Membership Inference Attack (MIA). Wir lockern alle Hauptannahmen des MIA und zeigen, dass solche Angriffe mit geringen Kosten breit anwendbar sind und somit ein größeres Risiko darstellen als bisher angenommen. Zweitens untersuchen wir die Updatephase. Zu diesem Zweck führen wir eine neue Angriffsmethode gegen ML-Modelle ein, nämlich die Änderung der Ausgabe eines ML-Modells vor und nach dem Update. Anschließend stellen wir vier Angriffe vor, einschließlich auch Angriffe zur Datenrekonstruktion, die sich gegen dieses Szenario richten. Drittens untersuchen wir die Trainingsphase. In diesem Zusammenhang schlagen wir den Angriff “Model Hijacking” vor, bei dem der Angreifer das Zielmodell für seine eigenen illegalen Zwecke übernehmen kann. Schließlich schlagen wir verschiedene Verteidigungsmechanismen vor, um solche Risiken zu entschärfen

The role of HvBWMK1 in barley tolerance to abiotic stress

Barley (Hordeum vulgare L.) is an important crop grown throughout the world. Quality and quantity of barley is compromised by abiotic stresses, salinity in particular which is already widespread in many regions. Mitogen Activated Protein Kinase (MAPK) cascades are signal transduction pathways involved in biotic and abiotic plant defence mechanisms. Here, the function of the barley gene HvBWMK1 has been investigated. Transgenic barley plants that overexpress HvBWMK1, or in which HvBWMK1 has been down-regulated by antisens, were generated, as well as empty vector control plants. The transformation efficiency using Agrobacterium was 10.4% independent transgenic plant per embryo. Northern blot analysis of HvBWMK1 primary overexpression lines showed up-regulation of mRNA level, conversely the antisense lines of HvBWMK1 showed clear down-regulation. Real-time PCR analysis in the T1 generation revealed that two over-expresser lines showed higher expression as compared with wild type (by 79% and 35%) while the HvBWMK1 antisense construct reduced endogenous gene expression partially (by 14%, 23% and 39% compared with wild type). Barley seedlings were subjected to two weeks of salt stress (150 mM NaCl) then biochemical and physiological parameters were measured. The overexpression lines showed an increase in tolerance to salinity stress compared to antisense lines and controls. Tolerance was accompanied with increasing endogenous proline and chlorophyll levels and a reduction in hydrogen peroxide content after salinity exposure. Overall these results suggest that the barley MAPK HvBWMK1 acts as a positive regulator in barley tolerance to salinity stress.Libyan Government Ministry of Higher Education and Scientific Researc

Women exclusive Ḥassānī love poetry: ət-təbṛā

La literatura popular hassaní trata todos los temas tradicionales de la poesía árabe clásica, pero añade además el género original de poesía amorosa compuesto por mujeres anónimas para expresar su amor hacia una figura masculina también anónima. Este género llamado ət-təbṛāˁ se compone de un sólo verso: təbṛīˁa.Ḥassānī popular literature encompasses all possible traditional topics of classical Arabic poetry, but it adds one more original genre: love poetry composed by anonymous women expressing their love towards an equally anonymous male figure. This genre called təbṛāˁ consists in just one verse: təbṛīˁa

Service Quality in the Context of the Egyptian Islamic Banking Industry

This study re-conceptualises service quality in an Islamic context. The conceptual framework underpinning this re-conceptualization sees service quality as a process which emanates from the management of an organization and how the philosophy of this organization is operationalized in the delivery of its services. As such, frontline employees are key elements in service delivery, and contributors to the quality of the service. In the Islamic context, in areas such as service quality, banks' management should understand that the perspective of Islam requires other distinctive services to be provided in addition to functional banking services. These are not limited to the narrow view, namely providing the traditional services and being in compliance with the legal side of Islamic law. The wider meaning includes other services such as social responsibility, contribution to the development of society and the distribution of Islamic financial knowledge. With regard to employees, especially frontline employees in the area of service quality, the Islamic philosophy should mean that considering Itqan (quality is the synonym for this term) should be understood as both a functional and religious duty. Employees' dealings with customers should extend beyond the functional aspects to an approach where customers are considered as `friends'. To investigate this framework, the current research was applied to Egyptian Islamic banks. It used mixed method- interviews with frontline employees and questionnaires distributed to customers, as well as support from field notes and examination of banks' websites. Egyptian Islamic banks, including their employees failed to understand, embody or practice the Islamic perspective on service quality. In the case of management, the failure was evident in issues such as an imbalance between providing functional and distinctive Islamic services. Customers' views were positive about the functional aspects of services and the legal side of financial transactions, but their views on the distinctive Islamic services were negative. Although employees confirmed that quality has Islamic roots represented in the term of Itqan (quality is the synonym for this term) as an inherent duty, the practice of this concept was not apparent to customers. To re-conceptualise service quality in the Islamic context, Islamic banks, including their employees should understand that customer praxis, the process by which the Islamic perspective on service quality is translated into action, was the most important dimension from the customer perspective. The instrument suggested to measure service quality generally and apart from the Islamic context, should be a customized scale that is context, country, industry and religion specific at a particular time

Elaboración de materiales de autoaprendizaje del Árabe Estándar Moderno (AEM) para el nivel A2 del Marco Común de Referencia y ponerlo a la disposición de los alumnos y los docentes en el Campus Virtual.

Depto. de Lingüística, Estudios Árabes, Hebreos y de Asia OrientalFac. de FilologíaFALSEsubmitte

Introducción a la paremiología árabe

A pesar del interés creciente y el desarrollo de los estudios paremiológicos en las diferentes lenguas del mundo, éstos son escasos en cuanto a la lengua árabe. Sin embargo, los inicios de los estudios gramaticales de la lengua árabe se caracterizaron por un gran interés por los proverbios y una intensa labor llevada a cabo por los filólogos, la cual permitió la recopilación de unas importantes colecciones en toda Arabia y en otras partes del Imperio Arabo-islámico. Esta labor fue proseguida durante varios siglos en Oriente y en al-Magreb. La Nahda, o «Renacimiento» que vivió el mundo árabe desde finales del s. XIX supuso una revitalización de la lengua árabe clásica que no podía prescindir del legado paremiológico de esta lengua. Por otra parte, los dialectólogos europeos se encargaron de recoger los refranes formulados en los diferentes dialectos del mundo árabe. Esta introducción ofrece el panorama de la paremiología árabe desde sus inicios hasta la actualidad