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The heated flow within the silencers of heavy transport vehicles can easily reach temperatures of hundreds of degrees Celsius. The thermal loads can cause problems for certain components on a silencer. In this case it has been seen in previous testing that screw joints attaching suspension brackets onto the silencer tend to lose pretension when heat is applied. The goal with this project is to investigate possible causes of the pretension losses and gain a deeper understanding of the joint’sbehavior. The project starts with a pre study with the purpose of obtaining knowledge of what is usually taken into consideration when designing joints for heated applications thatcould cause pretension losses. This was followed by an experimental part. Two main tests are made, firstly a friction test to ensure that the friction properties ofthe studs used in previous clamping force measurements were up to specification. Comparisons to a second batch of studs is also conducted. The second test is an oven test were test specimens of the joint is heat cycled in different temperatures for different assembly torques. This, in order to gain a deeper understanding of the joints´plastic behavior. The test pieces are cycled a total of five cycles and clamping force measurements are made after the first and fifth cycle. Measurements of clamping force are conducted through both ultrasonic and micrometer measurements of screw elongation. The results of the oven test are compared to the results of a finite element simulation. The finite element model is a model of the same test piece as in the tests, it captures the clamping force losses due to plastic deformation of components at heat up. However, the finite element model has its´ limitations, especially in the way the threads are modelled. This is to be taken into consideration and possibly utilized when interpreting the results. The takeaways from the pre study are that creep and stress relaxation, as well asembedding is highly unlikely primary causes for the pretension losses. More instant effects like plasticity due to the applied load is deemed more likely. The friction tests concluded that both of the batches´ friction properties are up to specification, but onethe batches thread friction is on the lower side.The results from oven test shows a temperature dependency in the losses and clea rsigns pointing towards a plastic collapse. All of the clamping force seems to be lost at initial heat up, no further signs of losses after 5 cycles. In comparison with the finite element model the plastic tendencies shows yet again, but most of the losses is not captured in the simulation. By taking into account the known weaknesses of the model, the two threaded components, weld nut and flange nut, are considered to be possible subjects of plastic deformation causing the pretension losses. The two measurement techniques show big deviations between them. It is therefore hard to interpret the absolute results of the pretension losses. In order to that a furtherstudy of how to value the two techniques should be conducted.

Heterogeneous wireless networking technologies such as satellite, UMTS, WiMax and WLAN are being used to provide network access for both voice and data services. In big cities, the densely populated areas like town centres, shopping centres and train stations may have coverage of multiple wireless networks. Traditional Radio Access Technology (RAT) selection algorithms are mainly based on the ¿Always Best Connected¿ paradigm whereby the mobile nodes are always directed towards the available network which has the strongest and fastest link. Hence a large number of mobile users may be connected to the more common UMTS while the other networks like WiMax and WLAN would be underutilised, thereby creating an unbalanced load across these different wireless networks. This high variation among the load across different co-located networks may cause congestion on overloaded network leading to high call blocking and call dropping probabilities. This can be alleviated by moving mobile users from heavily loaded networks to least loaded networks. This thesis presents a novel framework for load balancing in heterogeneous wireless networks incorporating the IEEE 802.21 Media Independent Handover (MIH). The framework comprises of novel load-aware RAT selection techniques and novel network load balancing mechanism. Three new different load balancing algorithms i.e. baseline, fuzzy and neural-fuzzy algorithms have also been presented in this thesis that are used by the framework for efficient load balancing across the different co-located wireless networks. A simulation model developed in NS2 validates the performance of the proposed load balancing framework. Different attributes like load distribution in all wireless networks, handover latencies, packet drops, throughput at mobile nodes and network utilization have been observed to evaluate the effects of load balancing using different scenarios. The simulation results indicate that with load balancing the performance efficiency improves as the overloaded situation is avoided by load balancing.

Part B of two parts. Part A found at: http://hdl.handle.net/11375/18745 / <p> This report studies the xenon transient behaviour in a CANDU reactor as a function of time after shutdown, start-up and power setbacks. In addition, load cycling transients were obtained for typical daily load requirements. </p> / Thesis / Master of Engineering (MEngr)

<p> A Matrix Stiffness-Modification Technique has been proposed for the inelastic analysis of ·reinforced concrete frames subjected to short term or sustained loads. To check the applicability of the analytical method, two large scale concrete frames were tested under short-term loads and sustained-loads respectively. In addition, data for twenty-two frame tests from other sources has also been compared with the non-linear analysis. Close agreement has. been observed for all the frames considered. It was further concluded that a conventional elastic matrix method using stiffnesses based on a cracked transformed section of concrete does net yield accurate results, especially in the case of sustained loading conditions. From the method developed, comments can therefore be made on present column design practice. </p> / Thesis / Master of Engineering (MEngr)

<p> A research program is presented for assessing the plastic collapse load and incremental collapse load of reinforced concrete frames. This investigation attempts to establish a range of validity of simple plastic theory when applied to the under reinforced concrete frames and to determine the sensitivity of such structures to variable repeated loading. </p> <p> An experimental program was conducted on 4 reinforced concrete frames and two reinforced concrete columns. Deflections and strains of these models of nearly prototype size were measured and compared with predicted values at critical cross-sections. </p> <p> Resulting conclusions and recommendations for further research are made. </p> / Thesis / Master of Engineering (MEngr)

One common software program developed for analyzing single laterally loaded piles is called LPILE. Soil properties are required as input into LPILE. For sands, the soil properties required are effective soil unit weight, γ’; subgrade modulus, k; and the internal friction angle, ϕ’. There are two commonly used methods to obtain ϕ’ and subsequently k: the API method and Bolton method. Fourteen different pile test sites were used in the analysis of the API and Bolton methods to obtain soil strength properties in sands for laterally loaded single pile tests. Between the fourteen pile test sites, a total of 26 piles were tested in the field and analyzed in LPILE using the API method and Bolton method to calculate the soil strength properties of the sands. After each pile test was analyzed in LPILE and compared to the field measured results, the two methods were compared graphically and percent errors were calculated between each method and the measured results to determine the optimal method in single laterally loaded pile design. Using the Bolton method to determine the soil strength properties gives more accurate load-deflection values with respect to measured values from field tests. The Bolton method accounts for dilation and the type of sand as well as the relative density and the mean effective stress of the soil. This leads to soil strength properties more characteristic of the soil at the site.

This thesis aims to explore the use of a predictive scaling algorithm to scale a microservices-based system according to a predicted system load. A scalable system along with a predictive scaling algorithm is developed and tested by applying a periodic load to the system. The developed scaling algorithm is a combination of a reactive and a predictive algorithm, where the reactive algorithm is used to scale the system when no significant load changes are predicted. The results show that the periodical load is predicted by the algorithm, that the system can be scaled preemptively, and that the algorithm has room for improvement in terms of accuracy. / Detta examensarbete siktar på att utforska möjligheten att använda förutsägande skalningsalgoritmer för att skala ett microservices-baserat system enligt en förutspådd belastning på systemet. Ett skalbart system utvecklas tillsammans med en förutsägande skalningsalgoritm, och testas genom att applicera en periodisk belastning på systemet. Den utvecklade skalningsalgoritmen är en kombination av en reaktiv och förutsägande algoritm, där den reaktiva algoritmen används för att skala systemet då inga signifikanta belastningar förutspås. Resultaten visar att systemets belastning kan förutspås och att systemet kan skalas med hjälp av den förutspådda belastningen, samt att algoritmen har utrymme för förbättringar.

Information systems provide users with valuable information that is relevant to users’ tasks, as well as irrelevant information that is not helpful to the user. Irrelevant information become a distraction and distract the users from their current task, there by impairing performance. Guided by distraction-conflict theory, processing efficiency theory, attentional control theory, cognitive load theory and memory for goals theory, this study investigated the distraction effect by exploring the research question, “How do task-irrelevant distractions interrupt the users of information systems and influence their performance?”. To investigate how distractions from technology influence users’ performance, this experimental research examined the relationship between the variables of distraction, cognitive load, anxiety and task performance. Data were gathered through lab experiment using imotion eye tracking system. The major findings revealed that task-irrelevant distraction negatively influenced the users by increase anxiety and cognitive load as well as increase the time devoted to primary task. We also found that the cognitive load partially mediates the relationship between distraction and time spending on task.

The parallelization of complex, irregular scientific applications with various computational requirements often results in severe load imbalance. Load balancing increases the efficient utilization of available resources in parallel and distributed applications, thereby reducing the overall processor completion times. Loops are a rich source of parallelism in data parallel applications. In recent years, several loop scheduling schemes that balance processor workloads have been proposed and have been successfully implemented in data parallel applications. If the workload on processors is balanced, then the overall efficiency of a computation increases, and that, in turn reduces the computation run-time. Therefore, loop scheduling routines are incorporated into applications to insure that the workload is balanced for all the available processors. Significant research effort has been made towards embedding the most competitive loop scheduling algorithms into specific scientific applications. The application developer has to rewrite the algorithm to be incor-porated into a different application, each time a new one is developed. Certain compilers take advantage of loops present in the application and perform automatic parallelization on them. However, the automatic parallelization doesn?t address all sources of algorithmic and systemic variances in heterogeneous environments. These limitations raise a compelling need for building an application programmable interface (API) for adaptive loop scheduling algorithms that can be incorporated into any scientific application. This thesis presents an API for various adaptive loop scheduling strategies for data parallel applications in a shared address space architecture, which allows for parallelization as well as adaptive load balancing of a scientific application. This API has been incorporated into a few scientific applications in order to evaluate the performance of each application using the adaptive loop scheduling routines on shared address space parallel machines against the automatic loop scheduling offered by present parallelizing compiler technology.