No description available.

Three novel approaches that are based on a recent communication technique called time compression overlap-add (TC-OLA), are introduced into pulse compression (PC) radar systems to improve the radar waveform shaping and enhance radar performance. The first approach lays down a powerful framework for combining the TC-OLA technique into traditional PC radar system. The new TC-OLA-based radar obtained is compared with other radars, namely traditional linear frequency modulation (LFM), and wideband LFM which has the same processing gain under different background situations. The results show the superiority of the proposed radar over the others. The second approach combines a random phase noise signal with a selected radar signal to build a new radar system, SSLFM radar, that enjoys the low-probability of intercept property, and, therefore, has higher immunity against noise jamming techniques compared with other radar systems. The properly recovery of the transmitted signal, however, requires a synchronization system at the receiver side. In this dissertation, we propose three synchronization systems each having different pros and cons. The last approach takes the radar waveform design methodology in a different direction and proposes a novel framework to combine any number of radar signal and transmit them simultaneously. Instead of trying to achieve universality through waveform shaping optimization, we do so via pluralism. As a proof of concept, all the proposed radars have been implemented and tested on software-defined radar (SDR). The theoretical and the experimental results showed the superiority of all proposed radar systems. Since TC-OLA is fundamental to this work, we add a chapter to propose a new technique called downsample upsample shift add (DUSA) to address the limitations of the existing implementation of TC-OLA. / Graduate

There is a significant gap in the body of knowledge concerning time-compressed multimedia instruction. Although research indicates that there is no loss in learning through well-designed multimedia instruction compressed at 25%, research is lacking that analyzes the effects of time-compression with learner-control included in the multimedia instruction. The aim of the study was to address this gap in the research by integrating learner-control into the interface of a time-compressed multimedia instructional lesson using similar methodologies from previous research. Effects were analyzed of time-compressed learner-controlled multimedia instruction on learning and perceived cognitive load. Additionally, the researcher employed a participant population from a corporate environment to increase the generalizability of the results. The researcher investigated two hypotheses concerning the differences in effects between a treatment group that used multimedia instruction featuring learner-control over two pre-determined compression speeds (0% and 25%) and a control group with no time-compression. The primary results of the study were that there was no significant difference in either learning or perceived cognitive load between the treatment and control group. Also, another noteworthy result was that only one-fifth of the participants in the treatment group (n=7) altered the compression speed during the presentation. One implication of these results is that learners might want more compression speed options during a presentation. Another implication is that learners might choose to use time-compression during a multimedia presentation if there was more information provided to the learner concerning what time-compression is and how it affects learning. Recommendations for future research include investigating the implications of this study and expanding the types of populations that are sampled for time-compressed multimedia research. Overall, both industry and academia must commit to aiding in the research of time-compression technology if its benefits and hindrances are ever to be fully explored.

[pt] Nesta dissertação são investigadas situações em que se faz necessária a sobreposição de informações digitais ao ambiente físico em que o usuário está, uma condição proporcionada pela utilização do recurso da Realidade Aumentada (RA). São consideradas, na pesquisa, aplicações da tecnologia que empregam a técnica de Video See-Through (VST) para utilização em celulares. São apresentadas diferentes definições de RA, delimitando-se conceitos tangentes à tecnologia, tais como Realidade Virtual e Computação Ubíqua, para promover uma discussão acerca das definições levantadas. Em seguida, se apresentam algumas soluções, mais encontradas no mercado, de aplicativos de RA para celular, analisando-se os impactos da utilização de ferramentas específicas no seu processo de criação e desenvolvimento. Considerando-se ainda aspectos sociais e filosóficos inerentes à tecnologia, busca-se uma melhor compreensão dos conceitos-base de espaço, tempo e realidade a que a RA recorre para operar, a fim de subsidiar a discussão acerca da tecnologia e criar o embasamento teórico para as análises subsequentes. / [en] This dissertation investigates situations that require the overlay of digital information to the user environment, a condition provided by the use of Augmented Reality (AR) technology. In the research, there are considered applications of the technology that uses the Video See-Through (VST) technique on mobile phones. The dissertation presents different definitions of AR, delimiting tangent concepts such as Virtual Reality and Ubiquitous Computing, to arouse a discussion about the definitions. Then, it presents some of the mobile applications most used in the market, analyzing the impact on using some specific tools in its creation and development process. Considering further social and philosophical aspects inherent to the technology, it seeks to better understand the basic concepts of space, time and reality that the AR uses to operate, in order to support the discussion about the technology and to create the theoretical basis for subsequent analysis.

Ericsson has recently experienced difficulties to meet the customer demand, which has led to lost market shares. This is mainly due to the long and unpredictable lead times within their supply chains. Therefore, Ericsson seeks to increase their ability to meet the customer demand by reducing the customer order lead time. A shorter lead time would imply a greater responsiveness and improved service level towards the customers. A directive from the company was to base the study on the supply chain for the customer Algeria Telecom Mobile. The purpose of the study is to give recommendations for improvements that reduce the total lead time in a supply chain perspective in order to improve the customer service level.  To be able to fulfill the purpose, four objectives were distinguished and supported with existing frameworks for analyzing supply chains. The first step was to create a current state map, which was achieved by conducting 24 interviews with people working within the supply chain. The second step was to identify potentials for lead time reduction. This was done by categorizing the supply chain parts and the problems that were gathered during the current state mapping into meaningful groups, and thereafter prioritize the categories with the greatest potential. The third step was to generate alternative solutions by conducting a second literature review based on the potentials that was identified during the prior step. The general solutions were later modified in order to fit the current supply chain. It resulted in eight Ericsson specific solutions. The fourth step was to evaluate these solutions in combination, which led to a recommended combination of solutions that provided the greatest lead time reduction. Also the requirements for implementing these solutions were presented in this step.  The recommendation for Ericsson is to rearrange their current supply chain for the studied customer and use two different supply chains; the Regional supply chain and the Alternative supply chain. The two arrangements will both be based on the implementation of a supply hub, which implies a movement of the customer order decoupling point closer to the customer. The Regional supply chain will cover the main flow and be used when the customer orders products from a product portfolio that has been agreed within the region. The Alternative supply chain will act as a complement and cover the flow of products outside the regional product portfolio.   The estimated customer order lead time for the Regional supply chain is 17 days, which is a reduction of 80 % in the normal case for the studied supply chain. The lead time for the Alternative supply chain is more difficult to estimate precisely, but it will be reduced in comparison with the current situation. Moreover, the service level towards the customer will be increased for both the Regional and the Alternative supply chain. To summarize the recommendations that are forwarded to Ericsson, they are listed below:  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Implement a regional supply hub  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Agree on a regional product portfolio  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Implement time slots for inbound flows  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Use BPO as a payment method instead of Letter of Credit  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Use a CIP, DAP or DAT Incoterm  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Implement a product configurator and let the customer place orders on commercial descriptions or a solution id.  <li data-listid="34" data-aria-posinset="15" data-aria-level="1">Integrate processes and activities throughout the supply chain and establish a greater information exchange.