Time-Frequency Warped Waveforms

The forthcoming communication systems are advancing towards improved flexibility in various aspects. Improved flexibility is crucial to cater diverse service requirements. This letter proposes a novel waveform design scheme that exploits axis warping to enable peaceful coexistence of different pulse shapes. A warping transform manipulates the lattice samples non-uniformly and provides flexibility to handle the time-frequency occupancy of a signal. The proposed approach enables the utilization of flexible pulse shapes in a quasi-orthogonal manner and increases the spectral efficiency. In addition, the rectangular resource block structure, which assists an efficient resource allocation, is preserved with the warped waveform design as well.Comment: 4 pages, 5 figures; accepted version (The URL for the final version: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8540914&isnumber=8605392

Résistance à la torsion de poutres-caissons en béton armé avec des barres d'armature longitudinale et d'armature tranversale constituée de cadres ou de spirales en PRFV

Les poutres-caissons en béton armé sont utilisées dans de nombreuses applications de génie civil incluant des ponts suspendus, des ponts piétonniers, des ponts courbes et des structures surélevées modernes pour le transport léger sur rail. L'utilisation de poutres-caissons en béton armé présente des avantages économiques et structurels, tels qu'un faible poids propre et une rigidité à la torsion plus élevée. Cependant de telles structures en béton armé sont généralement exposées à des environnements agressifs et/ou marins, entraînant la corrosion de l'armature en acier. Les barres d'armature en polymère renforcé de fibres (PRF) peuvent être utilisées comme alternative à l'armature d’acier pour éliminer ce problème de corrosion, ce qui permet de réduire les coûts de maintenance et rallonge la durée de vie des ouvrages. À ce jour, le comportement à la torsion de poutres-caissons en béton armé d’armature longitudinale et d’armature transversale en polymère renforcé de fibre de verre (PRFV) n’a pas été traité. Dans la cadre de cette thèse de doctorat, un programme expérimental a été conçu pour étudier le comportement à la torsion de poutres-caissons en béton armé avec des barres d’armature longitudinale et d’armature transversale constituée de cadres ou de spirales en PRFV. Dix-neuf poutres-caissons en béton armé de grandeur nature ayant une largeur de 380 mm, une profondeur de 380 mm, une longueur totale de 4 000 mm et une épaisseur de paroi de 100 mm ont été fabriquées et testées sous un moment de torsion jusqu'à la rupture. Les paramètres d'essai comprenaient la résistance en compression du béton, le taux d’armature longitudinale et le type d’armature (PRFV et acier), ainsi que le taux d’armature transversale et le type d’armature transversale (PRFV et acier sous forme de cadres et spirales). Les résultats des essais ont été analysés en termes de réseau de fissuration, de mode de rupture, de réponse moment-torsion, de déformations de l’armature, de contraintes du béton, et de résistance à la torsion. Un modèle analytique dit «softened membrane model» a été développé pour prédire le comportement en torsion (avant et après la fissuration) des poutres-caissons en béton armé avec des barres d’armature longitudinale et d’armature transversale constituée de cadres ou de spirales en PRFV. L'applicabilité de ce modèle analytique a été vérifiée à l’aide des résultats expérimentaux obtenus dans cette étude. De plus, un modèle Rahal non itératif a été modifié pour prédire la résistance à la torsion de poutres en béton armé, y compris les poutres à section pleine et les poutres-caissons.Abstract: Reinforced concrete (RC) box girders can be found in many civil-engineering applications. The most notable are cable-supported bridges, pedestrian bridges, curved bridges, and modern elevated structures for light rail transport. There are economic and structural benefits of using concrete box girders such as low self-weight of structures and higher torsional stiffness. Such structures are usually exposed to aggressive and/or harsh marine environments, leading to corrosion of the steel reinforcement. This type of corrosion in concrete structures is a prime cause of structural deterioration, particularly in North America, resulting in costly repairs, rehabilitation, and a considerable reduction in service life span. Fiber-reinforced polymer (FRP) reinforcing bars, on the other hand, can be used as an alternative to steel reinforcement to combat corrosion, thereby lowering maintenance costs and extending service life. In recent years, the torsional behavior of RC solid rectangular members reinforced with FRP bars has been the focus of many studies. Accordingly, all available FRP code standards and design guidelines that include torsional provisions were developed based on experimental work on solid rectangular members reinforced with FRP bars and tie stirrups. So far, the torsional behavior and strength of the concrete box girders reinforced with glass-FRP (GFRP) bars, ties, and spirals have not been discussed. In this research study, an experimental program was designed to investigate the torsional behavior of concrete box girders reinforced with GFRP bars, ties, and spiral. Nineteen full-scale RC box girders with a width of 380 mm, a depth of 380 mm, a total length of 4000 mm, and a wall thickness of 100 mm were designed, cast, and examined under pure torsional moment until failure. The torsion span was maintained constant at 2000 mm to ensure that each specimen developed at least one complete helical crack. The test parameters included the concrete strength, the longitudinal reinforcement ratio, and type (GFRP and steel), and the web reinforcement ratio, type (GFRP and steel), and configuration (ties and spirals). The test results were carefully analyzed in terms of cracking patterns, failure modes, torque-twist response, reinforcement strains, concrete strains, torsional strength, and twist capacity. The test results indicated that the stirrup's capacity strongly influenced the torsional strength of the GFRP and steel RC box girders, however, the stirrup stiffness did not affect the ultimate torque. The web reinforcement ratio and configuration had a significant effect on the torsional strength, post-cracking stiffness, and the distribution of diagonal cracks. Compared with normal-strength concrete (NSC), high-strength concrete (HSC) substantially improved the overall torsional performance of the tested specimens. An analytical softened membrane model was developed for predicting the entire torsional behavior (pre-and-post cracking) of concrete box girders reinforced with GFRP bars, ties, and spirals. The applicability of using this model was verified with the experimental results. In addition, a noniterative Rahal model was modified to predict the ultimate torsional strength of FRP-RC members, including solid and hollow members. Moreover, an analytical model was presented to estimate the post-cracking torsional stiffness of GFRP-RC members. Finally, the experimental test results were compared against the current FRP torsional design equations in the design guidelines, codes, and literature

Compliance of corporate businesses to health and environment standards. The case of cell phone towers in Egypt

This study explores the compliance of corporate businesses to the health and environment standards especially, the construction of cell phone towers, in Egypt. Also, it examines to what extent the mobile companies in Egypt adhere to the health and environment standards, namely in the residential areas (informal and poor areas). It demonstrates how the standards set in Egypt are not applied restrictively enough to ban the violations. Besides, there are negative impacts that might be found as a result of not complying with the health standards. In this study, the qualitative research methods were used in the form of in-depth interviews with the three mobile companies (Vodophone, Mobinil, Etisalat) and the Egypt governmental body (NTRA). The research findings showed that mobile companies in Egypt do not comply with the health and environment standards in many cases. In terms of health and environment standards, the study, based on the interviews in addition to the literature review, showed that setting up cell phone tower stations on the buildings\u27 roofs has negative impact in case of not complying with standards. Therefore, it could be considered as a source of danger, especially, to those who live close to towers. Also, the NTRA’s standards are not strong enough to ban the violations compared to other countries (Turkey, Tunisia, and South Africa). Moreover, the study reveals some reasons behind the violations such as: delivering good coverage, people’s attitude, building violations, and the most important reason is the weak role of the governmental body represented by the NTR

A study of official media outlets of Muslim Brotherhood group and Freedom and Justice Party in Egypt

Before the 25th of January revolution in Egypt, the types of Islamic media, such as Internet websites and television satellite channels, were focusing only on the education and interpretation of Islam. Furthermore, these Islamic media were not used as a tool to propagate for the political ideologies of Islamic movements. On the other hand, after the revolution, the Islamic media, specifically, television satellite channels start to act as a forum for the politics of the Islamists groups in Egypt. The main focus of this study aims at studying and examining the official media outlets of Muslim Brotherhood group and Freedom and Justice Party. In addition, this study aims to analyze how the Muslim Brotherhood group and Freedom and Justice Party use their official mass media to represent their visions and ideologies to the Egyptian public. The theoretical framework of this research is the Agenda Setting Theory with the focus of media Priming. This study examined how the official media outlets of Muslim Brotherhood group and Freedom and Justice Party apply the agenda setting through highlighting specific issues and ignoring other issues. This study is a content analysis of three official media outlets of Muslim Brotherhood group and Freedom and Justice Party which are: Misr 25 television satellite channel, Ikhwanonline Internet website, and Freedom and Justice Newspaper. The sample is non-probability sampling which is a Purposive Sample, and the sampling period is one composite week. This study consists of analyzing 7 issues of Freedom and Justice Newspaper, 7 days of Ikhwanonline Internet website, and a total of 63 hours of 18 television programs and talk shows of Misr 25 television channel. The findings of the study concluded that the Muslim Brotherhood group and Freedom and Justice Party use their official media outlets which are Misr 25 television channel, Ikhwanonline Internet website and Freedom and Justice Newspaper to convey their Islamic ideologies in different fields such as political issues, economic issues, social issues and religious issues to the masses in Egypt. Additionally, the findings of this research are in agreement with the theory of agenda setting theory because the official media outlets of Muslim Brotherhood group and Freedom and Justice Party highlight specific issues through repeating these issues; on the other hand, they have little coverage of other important issues. Regarding the media priming, the official media outlets of Muslim Brotherhood group and Freedom and Justice Party have some news that are salient than others. Furthermore, a lot of issues in the mass media of Muslim Brotherhood group and Freedom and Justice Party are obtrusive issues which mean that the audiences have a direct experience with these issues; therefore, the agenda setting effect may be low

Modular and reciprocity approaches to a family of diophantine equations

In this thesis we study the Diophantine equation xp - Dy2p = z2; gcd(x; z) = 1; p prime: We combine two approaches: - The modular approach using in Wiles's proof of Fermat's Last Theorem. - Elementary quadratic reciprocity. We show how using this combination of approaches and computer calculations we can get congruence conditions for the exponent p

Generic Tubelet Proposals for Action Localization

We develop a novel framework for action localization in videos. We propose the Tube Proposal Network (TPN), which can generate generic, class-independent, video-level tubelet proposals in videos. The generated tubelet proposals can be utilized in various video analysis tasks, including recognizing and localizing actions in videos. In particular, we integrate these generic tubelet proposals into a unified temporal deep network for action classification. Compared with other methods, our generic tubelet proposal method is accurate, general, and is fully differentiable under a smoothL1 loss function. We demonstrate the performance of our algorithm on the standard UCF-Sports, J-HMDB21, and UCF-101 datasets. Our class-independent TPN outperforms other tubelet generation methods, and our unified temporal deep network achieves state-of-the-art localization results on all three datasets

Digital Storytelling or Traditional Storytelling to develop EFL Students’ Oral Communication?

The present study investigated the effect of storytelling versus digital storytelling on developing fifth year EFL primary school pupils’ oral communication performance. The study adopted the quasi-experimental design. Sixty pupils of Dr. Ahmed Zewail primary School were distributed into two experimental groups. One group served as the first experimental group (n=30) who was taught in digital storytelling, whereas the second experimental group (n=30) was taught in traditional storytelling. The experiment lasted for six weeks. The instruments of the study included an oral communication skills test, an oral communication checklist, a semi-structured interview and a reflective log. They were approved by a panel of jury. Results indicated that there was a statistically significant difference between the mean scores of the first experimental group and that of the second one on the post-administration of the oral communication test for the first experimental group. Moreover, results revealed that there was a statistically significant difference between the responses of the first experimental group and that of the second one on the post-administration of the semi-structured interview favoring the first experimental group. As such, it was concluded that storytelling versus digital storytelling had a positive effect on developing fifth year EFL primary pupils’ oral communication performance

The Role of Writing Center Tutorials of ESL Students: Exploring Tutors, Tutees, and Instructors’ Perceptions

The purpose of this study was to investigate the role of the writing center tutorials. Based on the assumptions of the constructivist theory, this research tried to present a cognitive framework for better tutoring at the writing center and suggested better accommodations for ESL tutees. this exploratory study investigated the role of the writing center tutorials offered to ESL students through the perceptions of tutors, ESL tutees, and university instructors. Methods. Eighty nine international /ESL students and 23 tutors were selected. They were given a survey to respond to. Afterwards ten out of the 89 students and ten out of the 23 tutors were interviewed. Volunteering ESL students, tutors, and ten university faculty were interviewed to explore their perceptions toward the writing center tutorials. Moreover, the researcher observed the two writing centers in which the study was conducted. Data analysis. This Mixed Methods Research study combined a quantitative design using surveys and a qualitative part utilizing interviews, and non-participatory observation. Therefore, the result of the survey administered were statistically analyzed using independent samples T-tests. After the interviews, coding an analysis began to investigate similarities and dissimilarities among the participants’ responses. Tables of frequency were designed to examine the range between outliers and calculate percentages of each respondent in comparison to the other group members. Each theme had a representative code, a formulated meaning, frequency of the respondent, and a significant statement asserting such theme. The themes were collected across all cases to show frequency. Findings. The findings of this study revealed that the writing center is effective in improving ESL tutees’ writing skills that may also be transferable to their future careers. Additionally, this study asserted that the non-directive tutoring approach, the commonly used in the U.S. writing centers, is not the only effective tutoring mode for all ESL tutees. Most tutors, according to this study, may not apply this prescriptive non-directive tutoring. Consequently, the study concluded that a reasonable balance between the tutoring dichotomies can make a difference with ESL students. Furthermore, the study emphasized that tutors need specialized ESL training to better assist and accommodate ESL tutees