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Considering the communication systems with cyclic prefix (CP), such as orthogonal frequency-division multiplexing (OFDM) modulation and single-carrier cyclic prefixed (SCCP) modulation, when the length of CP is longer than the channel length, the use of cyclic prefix (CP) does not only eliminate the inter-block interference, but also convert linear convolution of the transmitted signal with the channel into circular convolution. Unfortunately, the use of CP significantly decreases the bandwidth utilization. Therefore, to reduce the length of CP is a critical issue. The thesis investigates that how to design a channel-shortening equalizer (CSE) at receiver which forces the length of the effective channel response as short as the CP length. The thesis describes the signal model as a matrix form. The effect channel response after CSE is investigated and then the coefficient of channel shortening filter is obtained using singular value decomposition method under various criterions. We further propose a novel CSE maximizing the shortening signal-to-interference ratio. In addition, it is demonstrated that the proposed CSE has the same performance as the conventional scheme but a lower computation complexity.

This thesis presents a study in which an attempt to verify a new protocol for evaluating team performance in terms of control was made, and this on teams performing navigation in high speed in real life, natural contexts. A second objective was to identify key factors for achieving control during high-speed navigation. The study was built upon the theories of Cognitive Systems Engineering and Naturalistic Decision Making (NDM). The study also made a first attempt to expand the protocol with the theories of NDM. A pilot test in the form of a field study was conducted upon military crews driving and navigating the Combat Boat 90H off the coast of Gothenburg, Sweden. The results of the study indicated both teams being in, at lowest, the tactical control mode, and one team occasionally making the transition to the strategic control mode. There were some methodological issues with using the protocol in real life, natural contexts and these were examined. In general, the protocol was found to be applicable in this field. Key factors for achieving control during high-speed navigation could not be properly identified because of contextual problems, but one possible factor was that the use of Hollnagel’s TETO principle appeared to increase control. / I denna rapport presenteras en studie vari ett försök har gjorts att verifiera ett nytt protokoll som utvärderar gruppers prestationsförmåga i termer av kontroll. Protokollet testades på grupper som utförde navigation i hög fart under verkliga och naturliga kontexter med ett andra syfte att identifiera nyckelfaktorer för att uppnå kontroll under navigering i hög fart. Studien byggde på teorier om Cognitive Systems Engineering och Naturalistic Decision Making (NDM). Denna studie var också ett första försök i att expandera protokollet med teorier om NDM. En pilotstudie med protokollet i formen av en fältstudie utfördes på militärbesättningar som körde och navigerade Stridsbåt 90H utanför Göteborgs kust. Studiens resultat indikerade att båda grupperna befann sig som lägst i den taktiska kontrollnivån varav en grupp vid enstaka några tillfällen uppnådde den strategiska kontrollnivån. Det uppstod en del metodologiska problem med att använda protokollet i en verklig och naturlig miljö vilket utvärderades i rapporten. Generellt så gick protokollet att använda på grupper som utförde navigering i hög fart. Nyckelfaktorer för att uppnå kontroll i under navigering i hög fart kunde inte väl identifieras på grund av kontextuella problem, men en möjlig nyckelfaktor ar användandet av Hollnagels TETO-princip, vilket verkade leda till en ökad kontrollnivå.

The aim of this research was to make recommendations on how to facilitate a healthy sense of Computer Self-Efficacy (CSE) in teachers of a primary school in South Africa. A literature study was conducted to determine a theoretical framework for the study. Thereafter a mixed method design was used to conduct an empirical investigation. This was done by means of focus group interviews, questionnaires and an observational narrative. The most important finding was that the teachers who participated in the research were professional and enlightened about the value of technology. They agreed that although daunted by the idea of technology it is essential for them to become proficient in the use of computers. The researcher came to the conclusion that the main obstacle that stands between the participants and technological proficiency was a weak sense of CSE. Recommendations were made on how one could use extrinsic motivation to introduce new technology in such a way as to enhance self-efficacy and as result computer self-efficacy. / Curriculum and Instructional Studies / M. Ed. (Adult Education)

The aim of this research was to make recommendations on how to facilitate a healthy sense of Computer Self-Efficacy (CSE) in teachers of a primary school in South Africa. A literature study was conducted to determine a theoretical framework for the study. Thereafter a mixed method design was used to conduct an empirical investigation. This was done by means of focus group interviews, questionnaires and an observational narrative. The most important finding was that the teachers who participated in the research were professional and enlightened about the value of technology. They agreed that although daunted by the idea of technology it is essential for them to become proficient in the use of computers. The researcher came to the conclusion that the main obstacle that stands between the participants and technological proficiency was a weak sense of CSE. Recommendations were made on how one could use extrinsic motivation to introduce new technology in such a way as to enhance self-efficacy and as result computer self-efficacy. / Curriculum and Instructional Studies / M. Ed. (Adult Education)

The multiple constant multiplication (MCM) operation is a fundamental operation in digital signal processing (DSP) and digital image processing (DIP). Examples of the MCM are in finite impulse response (FIR) and infinite impulse response (IIR) filters, matrix multiplication, and transforms. The aim of this work is minimizing the complexity of the MCM operation using common subexpression elimination (CSE) technique and redundant number representations. The CSE technique searches and eliminates common digit patterns (subexpressions) among MCM coefficients. More common subexpressions can be found by representing the MCM coefficients using redundant number representations. A CSE algorithm is proposed that works on a type of redundant numbers called the zero-dominant set (ZDS). The ZDS is an extension over the representations of minimum number of non-zero digits called minimum Hamming weight (MHW). Using the ZDS improves CSE algorithms' performance as compared with using the MHW representations. The disadvantage of using the ZDS is it increases the possibility of overlapping patterns (digit collisions). In this case, one or more digits are shared between a number of patterns. Eliminating a pattern results in losing other patterns because of eliminating the common digits. A pattern preservation algorithm (PPA) is developed to resolve the overlapping patterns in the representations. A tree and graph encoders are proposed to generate a larger space of number representations. The algorithms generate redundant representations of a value for a given digit set, radix, and wordlength. The tree encoder is modified to search for common subexpressions simultaneously with generating of the representation tree. A complexity measure is proposed to compare between the subexpressions at each node. The algorithm terminates generating the rest of the representation tree when it finds subexpressions with maximum sharing. This reduces the search space while minimizes the hardware complexity. A combinatoric model of the MCM problem is proposed in this work. The model is obtained by enumerating all the possible solutions of the MCM that resemble a graph called the demand graph. Arc routing on this graph gives the solutions of the MCM problem. A similar arc routing is found in the capacitated arc routing such as the winter salting problem. Ant colony optimization (ACO) meta-heuristics is proposed to traverse the demand graph. The ACO is simulated on a PC using Python programming language. This is to verify the model correctness and the work of the ACO. A parallel simulation of the ACO is carried out on a multi-core super computer using C++ boost graph library.