EVALUATION OF PARAGLIDING THEORY TEST ITEMS FOR PILOT LICENSE APPLICANTS Objectives: The aim of this work is to evaluate and optimize a set of paragliding the theoretical items appropriate for testing pilot license applicants of LAA ČR. Methods: This aim is realized by means of the theory of testing. Basic methods of testing form the background research of this work. The items were de- signed as multiple-choice, to select one correct answer. These items were assigned to the applicants for pilot licenses and were evaluated by the apparatus of testing. Microsoft Excel 2003 was used for collecting data and results evaluation. The computation according to the formulas in the theoretical part was performed in Matlab 2007b. Based on this analysis, the results were presented and optimization of these items was proposed. Results: Three hypotheses were examined in this work. The first dealt with a rela- tion between evaluated difficulty of test items and their points value, which was assigned by the LAA ČR. The second hypothesis concerned the number of used distractors. The third hypothesis was focused on the sensitivity of the items. The evaluated difficulty of test items matched items point value in 26 % of the number of items. 92 % of the alterna- tives were used and sufficient sensitivity had 78 % of...

In wireless networks, the exponentially increasing demands for wireless services are encountered by the scarcity of the available radio resources. More bandwidth is required for not only accommodating the increasing number of users, but also to meet the requirements of the new services such as TV on demand, wireless gaming, and mobile Internet. Non-orthogonal multiple access (NOMA) has attracted a great attention recently due to its superior spectral efficiency (SE) over orthogonal multiple access and could play a vital role in improving the capacity of future networks. In particular, power based NOMA multiplexes the users in power domain via superposition coding (SC) and allows them to access the whole spectrum simultaneously while using successive interference cancellation (SIC) at the receiver side for signal detection. Since NOMA exploits the power domain for multiple access, power allocation is vital to achieve superior SE with NOMA. Resource allocation and its optimization are general methods used to further improve the NOMA based networks performance. In this thesis, the resource allocation in the downlink NOMA system is considered and optimized for different objective functions such as the sum rate and the energy efficiency (EE). In addition, the combination of NOMA and multiple antenna is considered using linear and non-linear precoders. In all the considered cases, suboptimal power allocation schemes are proposed and compared to the numerically obtained optimal one. Results confirm that NOMA outperforms OFDMA. It also support the effectiveness of the proposed schemes as compared to the existing ones and to the optimal one. The results also reveal that using multiple antennas with NOMA can significantly enhance the overall performance. Furthermore, a NOMA-multicell scenario is considered to test the proposed schemes under the effect of intercell interference (ICI). The results prove that the proposed methods effective as compared to the optimal one at a much lower complexity.

Cheng Suk Hang. / "February 2005." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 142-160) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Ng Heung-ling, Margaret. / "April 2003." / Thesis (M.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 216-237). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

This thesis covers the investigation and application of continuous spatial models for multiple antenna signal processing. The use of antenna arrays for advanced sensing and communications systems has been facilitated by the rapid increase in the capabilities of digital signal processing systems. The wireless communications channel will vary across space as different signal paths from the same source combine and interfere. This creates a level of spatial diversity that can be exploited to improve the robustness and overall capacity of the wireless channel. Conventional approaches to using spatial diversity have centered on smart, adaptive antennas and spatial beam forming. Recently, the more general theory of multiple input, multiple output (MIMO) systems has been developed to utilise the independent spatial communication modes offered in a scattering environment.¶ Underlying any multiple antenna system is the basic physics of electromagnetic wave propagation. Whilst a MIMO system may present a set of discrete inputs and outputs, each antenna element must interact with the underlying continuous spatial field. Since an electromagnetic disturbance will propagate through space, the field at different positions in the space will be interrelated. In this way, each position in the field cannot assume an arbitrary independent value and the nature of wave propagation places a constraint on the allowable complexity of a wave-field over space. To take advantage of this underlying physical constraint, it is necessary to have a model that incorporates the continuous nature of the spatial wave-field. ¶This thesis investigates continuous spatial models for the wave-field. The wave equation constraint is introduced by considering a natural basis expansion for the space of physically valid wave-fields. This approach demonstrates that a wave-field over a finite spatial region has an effective finite dimensionality. The optimal basis for representing such a field is dependent on the shape of the region of interest and the angular power distribution of the incident field. By applying the continuous spatial model to the problem of direction of arrival estimation, it is shown that the spatial region occupied by the receiver places a fundamental limit on the number and accuracy with which sources can be resolved. Continuous spatial models also provide a parsimonious representation for modelling the spatial communications channel independent of specific antenna array configurations. The continuous spatial model is also applied to consider limits to the problem of wireless source direction and range localisation.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009.

This qualitative study explored the psychosocial experiences of children and adolescents with early-onset multiple sclerosis. In particular, an emphasis was placed on examing peer relationships and social behaviours in relation to these experiences. MS is a chronic neurological disease primarily affecting young adults. However, a proportion of MS patients have onset during childhood and adolescence. Very little is know about the psychosocial impact of MS on these children and adolescents. In particular, youth with MS may be at risk for negative peer experiences due to their chronic illness. Previous research suggested that negative peer experiences increase the risk of poor psychosocial development. In addition, research suggested that the social behaviours of these youth also impact the nature of their experiences with peers. Ultimately, this research aimed to provide insight into the psychoscial experiences of youth with MS and the role of their peer relationships. Six linked parent-youth pairs, from the MS Clinic in Calgary, AB, participated in semi-structured interviews to identify the issues that are pertinent to the participants' own experiences. Constant comparison analysis was then used to summarize the rante of psychosocial experiences in the adolescent participants. Data analysis was derived from grounded theory, which provided a framework for examining and categorizing interview data into themes. The categories were then constructed logically and systematically into a theoretical model which represented the data. Through this innovative grounded theory, a theoretical paradigm for understanding the psychosocial experiences of adolescents with MS was developed. The theory was comprised of two core categories: "the grief experience" and "dynamic relationships', each with several sub-categories. There were two primary conclusions drawn from the theory. The first reflected the significance of grief in understanding psychosocial experiences in adolescents with MS. The second identified that peer relationships play a variety of roles in this grief process. The second identified that peer relationships play a variety of roles in this grief process. The results of this study have many implications for the role of counsellors in the treatments of adolescents with MS. This model can act as a foundation for guiding therapeutic treatment of adolescents with MS. This model can act as a foundation for guiding therapeutic treatment and promoting future research in the area of psychosocial development in children and adolescents with early-onset MS. / xiv, 181 leaves ; 28 cm.

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