Analysis of Galileo E5 and E5ab code tracking

The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations. However, such developments bring various challenges to the receivers' designers. For example, acquisition and tracking stages turn into more complex processes while handling the increasing bandwidth requires additional processing power. In this context, we study the code tracking of Galileo E5ab in a full band or of only one of its components, i.e., either E5a or E5b. More specifically, an architecture for tracking the E5 pilot channel as an AltBOC(15,10) or BPSK(10) modulation is introduced, and the performance of well-known discriminator types is analyzed using analytical derivations and simulations of linearity and stability regions, thermal noise tracking errors, multipath error envelopes and tracking thresholds. Different parameters, such as the front-end filter bandwidth, the early/late chip spacing, un-normalized and normalized discriminators, are taken into consideration. The results obtained are used to illustrate the main advantages and drawbacks of tracking the E5 signal as well as to help defining the main tracking loop parameters for an enhanced performanc

Etude de l'impact sur pale d'hélicoptère

Le présent article propose une étude de l’endommagement de structures similaires à des tronçons de pales d’hélicoptère soumises à un impact. Il s’agit de structures composites complexes, fabriquées au laboratoire, et impactées par un projectile de 125 g à des vitesses d’impact de 130 m/s. Les essais sont analysés grâce à une acquisition des déformations au cours de l’essai et à une expertise post-mortem de l’éprouvette. Cela a permis de mettre en évidence les différents mécanismes d'endommagement de l'éprouvette. Un travail de modélisation est aussi présenté. Différentes stratégies de modélisation sous éléments finis, à l’échelle macroscopique, permettent ainsi de modéliser ces phénomènes avec des densités de maillage qui ne sont pas pénalisantes lors d'un calcul sur une structure réelle

Analysis, design and implementation of front-end reconfigurable antenna systems (FERAS)

The increase in demand on reconfigurable systems and especially for wireless communications applications has stressed the need for smart and agile RF devices that sense and respond to the RF changes in the environment. Many different applications require frequency agility with software control ability such as in a cognitive radio environment where antenna systems have to be designed to fulfill the extendable and reconfigurable multi-service and multi-band requirements. Such applications increase spectrum efficiency as well as the power utilization in modern wireless systems. The emphasis of this dissertation revolves around the following question: Is it possible to come up with new techniques to achieve reconfigurable antenna systems with better performance?\u27 Two main branches constitute the outline of this work. The first one is based on the design of reconfigurable antennas by incorporating photoconductive switching elements in order to change the antenna electrical properties. The second branch relies on the change in the physical structure of the antenna via a rotational motion. In this work a new photoconductive switch is designed with a new light delivery technique. This switch is incorporated into new optically pumped reconfigurable antenna systems (OPRAS). The implementation of these antenna systems in applications such as cognitive radio is demonstrated and discussed. A new radio frequency (RF) technique for measuring the semiconductor carrier lifetime using optically reconfigurable transmission lines is proposed. A switching time investigation for the OPRAS is also accomplished to better cater for the cognitive radio requirements. Moreover, different reconfiguration mechanisms are addressed such as physical alteration of antenna parts via a rotational motion. This technique is supported by software to achieve a complete controlled rotatable reconfigurable cognitive radio antenna system. The inter-correlation between neural networks and cellular automata is also addressed for the design of reconfigurable and multi-band antenna systems for various applications.\u2

Defining environmental and cultural landmarks in Lebanese villages through an integrated public participation GIS method -

Thesis. M.S.E.S. American University of Beirut. Interfaculty Graduate Environmental Sciences Program (Ecosystem Management), 2014. ST:6027Advisor : Dr. Salma Talhouk, Professor, Landscape Design and Ecosystem Management ; Members of Committee: Dr. Mahmoud Al Hindi, Assistant Professor, Mechanical Engineering ; Dr. Mounir Mabsout, Professor, Civil and Environmental Engineering ; Dr. Gabriella Trovato, Assistant Professor, Landscape Design and Ecosystem Management.Includes bibliographical references (leaves 54-56)The complexity and changeability of both the landscape concept and the human valuation process make people’s designation of various landscapes values not well understood. Previous landscape research has tended to concentrate on one physical landscape component, such as water, built areas or flora; and on one value such as landscape aesthetics. To date, no study has empirically surveyed and studied, at a regional or national scale, the relationship between the diverse landscape components with the perceived landscape values of people (Brown, 2006). We spatially overlapped aerial photographs and valued landscape components (represented by the icons and stories selected by the people) through a nationwide public participation GIS (PPGIS) process and by using the Open Green Map (OGM) system’s set of international icons. We discuss the benefits and limitations of the method for stock taking of baseline information for landscape planning. We used matrix grading evaluations to identify significant sustainable management systems of communal lands and their spatial associations in relation to the mapped landscape components. This study validates the effectiveness of public participatory GIS (PPGIS) in relation to efficiency of data basing in a data poor context, community involvement in an ethnically diverse nation, and the related planning outcomes at the level of local municipalities and national ministries

Reading Karl Barth\u27s Trinitarian Theology of Freedom in the Sociopolitical Context of Chin Christianity

This thesis argues that the act of reading Barth’s Trinitarian theology of freedom in the Chin context helps the Chin to acquire a new understanding of the Trinity, which reminds them of how the triune God stands in solidarity with them in their hard situation and how the triune God gives them freedom, which empowers them to engage their sociopolitical environment in a positive way. The sense of this Trinitarian logic requests the Chin evangelical and ecumenical Christians to appropriate the implications of Barth’s Trinitarian theology for reshaping their Trinitarian misperceptions underlined by the tendency to perceive the Trinity in a detached and individualistic way. Their interaction with Barth’s view leads them to notice that the Father, the Son, and the Holy Spirit always work in the shared divine mission of recreating, redeeming, and transforming humanity in its existential world. The picture of how the triune God embraces humanity and gives the gift of freedom to the latter basically reflects the indivisible, harmonious, and interdependent work of the triune God. This Trinitarian imagination will stand as a constructive inspiration for Chin theologians and pastors to improve their “pastoral” engagement with the suffering Chin, and also to reclaim the “political” role of Chin Christianity in response to the realities of their sociopolitical context. The function of this Trinitarian principle primarily deals with how the belief of God’s solidarity with humanity inspires the life of the dehumanized Chin and how their encounter with God in this setting transforms and shapes them to live freely for God and for the good of others

The Relationship between Substance Abuse and Suicide among Adolescents

Suicide, prominent in adolescents, presents a major public health problem. This study examined the relationship between substance abuse and suicide among adolescents after adjusting for socio-demographic, interpersonal violence, and mental health variables. Data were drawn from the Youth Risk Behavior Survey. Suicidal measures included ideation, plan, attempts, and severe attempts. Substance abuse, depression, purging, and forced sex were the major predictors. Our findings may be of value to educators, providers, and policymakers in helping to target teens contemplating suicide. To curb incidence of suicidal thoughts and behavior among teens, routine screenings for substance abuse in schools is recommended

The Relationship of Sexual Health Education and Sexual Health Risk Behavioral Outcomes among Florida Teens

We examined the relationship between sexual health education and sexual health risk behavioral outcomes among adolescents in Florida using Youth Risk Behavior Survey data from 2001 to 2013. Sexual health risk behavioral outcomes (reported condom use and alcohol and/or drug use during last intercourse) were first examined as a function of sexual health education. Multiple logistic regression analysis was then used to adjust for individual characteristics and behavioral risk factors when associating sexual health education with sexual health risk behavioral outcomes. Reported condom use was strongly associated with sexual education. However, the impact of sexual education was attenuated after adjusting for individual characteristics and behavioral risk factors. Alcohol and/or drug use during last intercourse was strongly associated with behavioral risk factors: forced sex and being sad/hopeless. Those receiving sexual education were 44% less likely to use alcohol and/or drugs. The results may be of value to policy makers in helping to profile and target teens at risk for sexually transmitted infections. These findings have important sexual health education implications and shed light on the role that individual health behaviors play in the health outcomes of adolescents

School Bullying and Health Risk Behavior Outcomes among Adolescents in Florida

Background: School bullying is a major social and public health threat as it presents a variety of developmental and psychological adolescent hazards that stretch into adulthood problems. Bullying victimization has been linked with a plethora of adverse health risk behavior outcomes. Purpose: To examine the association between bullying (in-person and electronic) and health risk behaviors related to school violence, mental and sexual health risks, substance abuse, and weight control practices. Methods: Data were drawn from the Florida Youth Risk Behavior Survey (YRBS). A 4-level variable was generated using the in-person and electronic bullying questions resulting in four mutually exclusive bullying categories. Logistic regression analyses, stratified by sex, examined the relationship between bullying and health risk behaviors related to violence, mental health, substance abuse, and weight-related factors after adjusting for race and grade. Results: Rates of victimization among students varied; 6.4% of students reported being bullied both in-person and electronically, 7.6% reported in-person bullying only, 4.4% reported being electronically bullied only, and 81.6% were uninvolved. Bullying was associated with almost all the health risk behavior outcomes studied with a few exceptions. Experiencing both kinds of bullying was most strongly associated with forced sexual intercourse for female adolescents as compared to suicide attempts for male adolescents. Discussion: Schools should provide safe and supportive environments and implement policies to prevent the long-term harmful effects of bullying

A 3D printed monolithic soft gripper with adjustable stiffness

Soft robotics has recently gained a significant momentum as a newly emerging field in robotics that focuses on biomimicry, compliancy and conformability with safety in near-human environments. Beside conventional fabrication methods, additive manufacturing is a primary technique to employ to fabricate soft robotic devices. We developed a monolithic soft gripper, with variable stiffness fingers, that was fabricated as a one-piece device. Negative pressure was used for the actuation of the gripper while positive pressure was used to vary the stiffness of the fingers of the gripper. Finger bending and gripping capabilities of the monolithic soft gripper were experimentally tested. Finite element simulation and experimental results demonstrate that the proposed monolithic soft gripper is fully compliant, low cost and requires an actuation pressure below -100 kPa