International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Transmit diversity schemes such as the Alamouti space-time code have been shown to be viable candidates to enable robust dual-antenna transmission from maneuvering air vehicles. However, due to the complicated structure of shaped offset quadrature phase shift keying (SOQPSK) modulation, the Alamouti approach has not been applicable to SOQPSK systems. This paper develops a precoding and detection algorithm which allows implementation of dual-antenna Alamouti signaling for SOQPSK modulation. Performance simulations demonstrate the performance of the scheme for a realistic flight scenario.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The use of two antennas on an aeronautical telemetry transmitter is a common practice for overcoming signal obstruction that can occur during air vehicle maneuvering. However, this practice also leads to interference nulls that can cause dramatic degradation in the average signal integrity. This paper discusses the application of a transmit diversity scheme capable of overcoming this interference problem. The development leads to symbol error probability expressions that can be applied to assess the performance of the scheme relative to that of traditional schemes. Representative computational examples demonstrate the potential of the method.

International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, Nevada / A major factor in the performance of a Telemetry System over the sea is the effect of multipath. The reflected signal from the surface of the sea may, in general, add to or subtract from the direct signal, and may therefore lead to severe fading and possible loss of useful signal. The multipath is a function of the sea state and the polarization of the signal. In order to reduce the effect of multipath on performance, a dual polarization diversity system is being built for the Airborne Telemetry Relay System for the Gulf Range. An analysis of the performance of the dual polarization diversity system in the presence of multipath for different sea states, different reflection angles, and different initial polarization angles is presented. For comparison, a similar analysis is presented for a circular polarization receiving antenna system.

Den tyska lärlingsutbildningen är ett dualt utbildningssystem där praktiska och teoretiska kunskaper lärs ut, både i skolan och på en arbetsplats. Utbildningsformen har en lång tradition och är väl etablerad i det tyska samhället. Diskussioner kring utbildningens utformning präglas av de föreställningar som finns kring praktisk och teoretisk kunskap. Detta gäller generellt för utbildningssystem i olika länder. Redan i antiken lade Platon och Aristoteles grunderna till den kunskapssyn som lever kvar i vårt samhälle än i dag. Praktisk kunskap värderas ofta lägre än teoretisk kunskap. Det finns även en föreställning om att det är den teoretiska kunskapen som ska eftersträvas i högsta möjliga mån. I den här kvalitativa studien undersöktes hur tyska lärlingselever ser på praktisk och teoretisk kunskap, hur de upplever att praktisk och teoretisk kunskap hänger samman samt hur de ser på status i samband med praktisk och teoretisk kunskap. I undersökningen användes fokusgruppintervjuer som undersökningsmetod. Lärlingselever med olika utbildningsinriktningar intervjuades och därefter analyserades elevernas utsagor. Resultaten visade att lärlingseleverna definierar praktisk och teoretisk kunskap utifrån de föreställningar som länge har funnits kring de olika kunskapsformerna. De upplevde att praktisk och teoretisk kunskap bildar en enhet och att båda kunskapsformerna behövs. Lärlingseleverna framhävde att de lär sig bäst när de själva får utföra en handling samt att fel och feedback främjar lärprocessen. När det gäller status upplevde lärlingseleverna att deras utbildning har en låg status samt att deras arbete inte uppskattas i samhället. Resultaten analyserades utifrån tidigare forskning på området samt John Deweys teorier om praktisk och teoretisk kunskap: intelligent action, learning by doing samt status i förhållande till praktisk och teoretisk kunskap.

This is a longitudinal study that examines children's perspectives on the development of biliteracy. The theories of children as they learn through two languages reflect a crucial source of knowledge that has received little attention in the research. This study is concerned with the ways in which children learn to read and write in two languages for academic and social purposes as they encounter discourse laden with ideological contradictions.Using a case study design, the study draws on theoretical frameworks from the fields of language socialization, biliteracy, dual language education, and middle school literacy. By showing that children hold sophisticated notions of biliteracy, transforming the ways that language, oral and written become defined and perceived, the research presented here demonstrates that biliteracy is a complex phenomenon that includes meaning-making in two languages and cultures.The study triangulates ethnographic data from interviews with students, families and teachers, participant observation in classrooms, literacy instruction, other school domains, and document and archival analysis. These data indicate that there are multiple paths to biliteracy and that home and school literacy practices can mediate the effects of low income status on literacy development. Additional findings indicate that curriculum and instruction that consistently support minority language literacy promote the development of additive biliteracy in both language majority and language minority students.

No description available.

This dissertation presents new circuit architectures and techniques for improving the performance of several key BiCMOS RFIC building blocks used in radar and wireless communication systems operating up to millimeter-wave frequencies, and the development of an advanced, low-cost and miniature millimeter-wave concurrent dual-band transmitter for short-range, high-resolution radar and high-rate communication systems. A new type of low-power active balun consisting of a common emitter amplifier with degenerative inductor and a common collector amplifier is proposed. The parasitic neutralization and compensation techniques are used to keep the balun well balanced at very high frequencies and across an ultra-wide bandwidth. A novel RF switch architecture with ultra-high isolation and possible gain is proposed, analyzed and demonstrated. The new RF switch architecture achieves an ultra-high isolation through implementation of a new RF leaking cancellation technique. A new class of concurrent dual-band impedance matching networks and technique for synthesizing them are presented together with a 25.5/37-GHz concurrent dual-band PA. These matching networks enable simultaneous matching of two arbitrary loads to two arbitrary sources at two different frequencies, utilizing the impedance-equivalence properties of LC networks that any LC network can be equivalent to an inductor, capacitor, open or short at different frequencies. K- and Ka-band ultra-low-leakage RF-pulse formers capable of producing very narrow RF pulses in the order of 200 ps with small rising and falling time for short-range high-resolution radar and high-data-rate communication systems are also developed. The complete transmitter exhibiting unique characteristics obtained from capabilities of producing very narrow and tunable RF pulses with extremely RF leakage and working concurrently in dual bands at 24.5 and 35 GHz was designed. Capability of generating narrow and tunable RF pulses allows the radar system to flexibly work at high and multiple range resolutions. The extremely low RF leakage allows the transmitter to share one antenna system with receiver, turn on the PA at all time, comply the transmitting spectrum requirements, increase the system dynamic range, avoid harming to other systems; hence improving system size, cost and performance. High data-rate in communication systems is achieved as the consequence of transmitting very narrow RF pulses at high rates. In addition, the dissertation demonstrates a design approach for low chip-area, cost and power consumption systems in which a single dual-band component (power amplifier) is designed to operate with two RF signals simultaneously.

The purpose of the study is to better understand the extent to which dual credit contributes to increased access and participation in college. As an initiative to facilitate the transition from high school to college for many students, dual credit has grown in scale and popularity in Ontario in recent years. By giving participating students credit towards both secondary school and college, dual credit is seen as a particularly effective mechanism in assisting disengaged students and groups under-represented in postsecondary education achieve success in high school and college. Still at an early stage of implementation in Ontario, little formal research has been conducted to explore the elements contributing to the program’s success and the benefits and outcomes for participants. Through the use of mixed methods of research, the study explores from a case study perspective the experience of dual credit at a single Ontario college in collaboration with its local partner school boards. Research methods include examination of student grades, policy and program documentation; student and parent surveys; and interviews with staff involved in planning and delivery. The analysis is informed by conceptual frameworks of student change allowing for consideration of a broad range of variables. Results of the study revealed that dual credit was deemed to be a success by students, parents and staff involved with the programs. Dual credit was viewed as particularly effective in terms of academic benefits and creating a greater awareness of college, contributing to student confidence and leading to increased likelihood of college participation. Dual credit participants were found to be primarily middle achievers academically, tended to perform better in dual credit courses than in high school, and obtained slightly higher grades than college peers in the same courses. Given the program delivery models studied, it was concluded that middle achievers were likely to benefit most. The study also concluded that student characteristics including pre-existing confidence and motivation should be considered an important element of success along with program elements and institutional factors. As an innovative program demonstrating positive results, more research should be done to assist in developing dual credit further.

Extreme poverty is a reality facing over a billion people, and a striking contradiction is that huge disparities coexist with a relatively rapid economic growth. This thesis investigates whether economic growth reduces poverty. Through an empirical cross-sectional regression, it analyses what impact economic growth has on poverty, and what structures that possibly preserve these phenomena. The theories of Dual Economy and Human Capital are used to explain such structures that cause poverty to coexist with growth. Brazil is an example of a dual economy whose recent history is characterised by successful economic and public policies that have managed to reduce the level of extreme poverty. Structures of dualistic labour markets contribute to the preservation of the extreme poverty, thus they do have some explanatory power of the coexistence of poverty and growth. The main conclusion from the empirical results is that economic growth does indeed reduce poverty. Also the level of poverty is strongly related to decrease of poverty, in such a way that a high level of poverty is associated to a slow decrease of poverty. However, economic growth does not appear to be sufficient a tool when the level of extreme poverty is high, suggesting that well-designed policies and investments in education are needed to obtain an inclusive, pro-poor growth and thus reduce the level of extreme poverty.

The research presented in this Thesis aims at defining the strengths and weaknesses of an Improved 1D/1D model when compared with a more accurate 1D/2D model. Although both coupled-models (sewer/surface) solve the St.\ Venant equations in both layers, the latter uses a higher approximation (2D two-dimensional) on the surface layer. Consequently, the 1D/1D model is computationally more efficient when compared to the 1D/2D model, however there is some compromise with the overall accuracy. The hypothesis is that "The inundation extent of urban flooding can be reproduced by 1D/1D models in good agreement with the 1D/2D models if the results are kept within certain limits of resolution and under certain conditions". The Thesis starts by investigating ways of improving an existing 1D/1D model to rival the more accurate 1D/2D model. Parts of the 1D/1D model code are changed and new algorithms and routines implemented. An innovative GIS tool translates the 1D output-results into 2D flood-inundation-maps enabling a thorough comparison between the two models. The methodology assures the set-up of two equivalent models, which includes a novel algorithm for calibrating the 1D/1D model vs.\ the 1D/2D model results. Developments are tested in two distinctly different case studies of areas prone to flooding. The conclusion is that the 1D/1D model is able to simulate flooding in good agreement with the 1D/2D model; however, it is found that features such as topography, density of the urbanised areas and rainfall distribution may affect the agreement between both models. The work presented herein is a step forward in understanding the modelling capabilities of the analysed coupled-models, and to some extent may be extrapolated to other models. Research is growing in urban flooding and this work may well prove to be a strong foundation basis for future research.