Berlin, Freie Universiẗat, Diss., 2003. / Dateiformat: zip, Dateien im PDF-Format.

The impact of instant message interruptions via computer on immediate lecture retention for college students was examined. While watching a 24–minute video of a classroom lecture, students received various numbers of related–to–lecture (“Is consistent use of the eye contact method necessary for success?”) versus not–related–to lecture (“Have you ever missed class because you couldn't find parking?”) instant messages in addition to note taking vs. no note taking. Student self–rating for multitasking ability, typical and maximum instant messaging activity, and classroom computer use were also measured. Contrary to cognitive models of information processing that suggest instant messages will disrupt student retention of lecture information, no effects were found for number of interruptions, presence or absence of notes, or relatedness of interruption on lecture retention. Students’ multitasking self–rating was negatively related to lecture retention. The implications of these results for classroom practice and future research are explored. / text

In this thesis, we propose a new bandwidth-enhancement method of using a parasitic open slot to achieve a wide lower band for the internal laptop computer antenna with a small size to cover the GSM850/900 operation and a wide upper band to cover the GSM1800/1900/UMTS operation as well. The occupied antenna volume is only 48 ¡Ñ 10 ¡Ñ 3.5 mm^3 above the top edge of the display ground. For practical application, we analyze the effects of the antenna position, nearby metal plate, shielding metal plate, keyboard ground, FR4 substrate, and the size of display ground on the performance of the WWAN antenna. In addition, effects of the user¡¦s whole-body on the proposed antenna are also analyzed. Owing to the user¡¦s whole-body being mainly lossy materials, a decrease in the antenna¡¦s radiation efficiency is observed when the user¡¦s whole-body is in close proximity to the WWAN laptop computer antenna.

For applications of wireless communication of the fourth generation (4G LTE), the technique of using a printed parallel-resonant spiral strip for bandwidth enhancement of a small-size planar laptop computer (especially the thin Ultrabook) antenna for the LTE operation is first presented. The antenna is printed on a thin FR4 substrate of small size 45 x 9 mm2 with a simple uniplanar structure which is promising for Ultrabook application. Based on the proposed antenna structure, its application for MIMO operation to achieve enhanced isolation is also analyzed in this thesis. Different from the works for the relatively much smaller ground plane conditions such as in the mobile phones, the effect of different size of the supporting conductive plate of the upper corner of the Ultrabook is discussed for the isolation issue of the MIMO antennas. Finally, the technique of isolation improvement in the LTE700 band for the MIMO operation in the Ultrabook is presented.

Two novel internal WWAN antennas having multi-band operation capability and suitable to be embedded in the laptop computers are proposed. The first antenna is a penta-band printed monopole slot antenna, which can cover GSM850/900/1800/1900/UMTS operation. The second antenna is a penta-band printed dual-loop antenna. The antenna can cover GSM850/900/1800/1900/UMTS operation and occupies a small size. The effects of the environment and the user¡¦s hand on the internal laptop computer antenna are also studied. Take the first antenna as an example; the obtained results show that the effects of the internal environment of the laptop computer are mostly on the antenna¡¦s impedance matching, which however can be improved by adjusting the parameters of the antenna. On the other hand, since the user¡¦s hands are lossy materials, a decrease in the antenna¡¦s radiation efficiency is observed when the user¡¦s hand is in the vicinity of the internal antenna.

This report summarizes a Bachelor Degree Project in Product Design Engineering, carried out during the spring semester in 2007 by one student on the Product Design Engineering programme at University of Skövde. The project was performed as an assignment for Comfort Cooling AB, a company in Skövde that manufactures cooling clothes and products for medical use. The purpose of the project is to design a suitcase for laptops that is used also as a workstation. It has a cooler system, provided by Comfort Cooling that works with no external energy. It has a base made of foam sheet, to adapt it to the legs of the user. And it has as well all the normal features characteristically of a suitcase for laptops, such as pockets, handles and security features. The first step in the project was to perform market research in order to gather customer needs. It was found that the primary features of a laptop suitcase are that it is waterproof, that it is possible to carry the suitcase on ones back, that there are trays on both sides of the suitcase, and that the suitcase will be available in a range of patterns and colours. After that, the design of the possible solutions for each requirement started to be developed. Once all the requirements of the project were satisfied with different solutions, each one of them were evaluated in order to identify the solutions that in the best way met the stated product requirements. Finally a mock-up was produced for communicating the final design proposal and for enabling basic user trials to be carried out, as well as the final result, i.e. the design and the mock-up of the laptop suitcase. The report portrays the product design process and methods utilized in the project, as well as the final result (the mock up) of the laptop computer bag with integrated cooling effect and workstation.

<p>This report summarizes a Bachelor Degree Project in Product Design Engineering,</p><p>carried out during the spring semester in 2007 by one student on the Product Design</p><p>Engineering programme at University of Skövde. The project was performed as an</p><p>assignment for Comfort Cooling AB, a company in Skövde that manufactures cooling</p><p>clothes and products for medical use.</p><p>The purpose of the project is to design a suitcase for laptops that is used also as a</p><p>workstation. It has a cooler system, provided by Comfort Cooling that works with no</p><p>external energy. It has a base made of foam sheet, to adapt it to the legs of the user. And it</p><p>has as well all the normal features characteristically of a suitcase for laptops, such as</p><p>pockets, handles and security features.</p><p>The first step in the project was to perform market research in order to gather</p><p>customer needs. It was found that the primary features of a laptop suitcase are that it is</p><p>waterproof, that it is possible to carry the suitcase on ones back, that there are trays on both</p><p>sides of the suitcase, and that the suitcase will be available in a range of patterns and</p><p>colours. After that, the design of the possible solutions for each requirement started to be</p><p>developed. Once all the requirements of the project were satisfied with different solutions,</p><p>each one of them were evaluated in order to identify the solutions that in the best way met</p><p>the stated product requirements. Finally a mock-up was produced for communicating the</p><p>final design proposal and for enabling basic user trials to be carried out, as well as the final</p><p>result, i.e. the design and the mock-up of the laptop suitcase.</p><p>The report portrays the product design process and methods utilized in the project,</p><p>as well as the final result (the mock up) of the laptop computer bag with integrated cooling</p><p>effect and workstation.</p>

In this thesis, the studies mainly focus on recent trends in novel MIMO antennas for indoor wireless communication system. Firstly, we propose a novel MIMO antenna for access-point application. This proposed antenna can reduce the lateral length of the conventional access-point antenna for MIMO application. Then, we present MIMO antenna designs for mobile devices such as PDA phones and laptop computers. Although these two devices are of different configurations, the PIFAs are applicable in these two devices, and their design rules are basically the same. Thus, for this study, the design consideration of the MIMO antenna will focus on S-parameter analysis. Detailed antenna designs and experimental results are presented and discussed in this thesis.