Master thesis work at ITN (Department of Science and Technology) in the areas of A/D-construction and RF-circuit design. Major goal of project were to research suitable possibilities for implementations of direct conversion in transceivers operating in the 160MHz band, theoretic study followed by development of components in the construction environment Cadence. Suitable A/D- converter and other important parts were selected at the end of the theoretic study. Subsampling technique was applied to make A/D sample requirements more realistic to achieve. Besides lowering requirements on A/D-converter it allows a more simple construction, which saves more components than subsampling adds.

The availability of digital models of real 3D objects is becoming more and more important in many different applications (e-commerce, virtual visits etc). Very often the objects to be represented cannot be modeled by means of the classical 3D modeling tools because of the geometrical complexity or color texture. In these cases, devices for the automatic acquisition of the shape and the color of the objects (3D scanners or range scanners) have to be used. The scanner presented in this work, a Shape from silhouette scanner, is very cheap (it is based on the use of a simple digital camera and a turntable) and easy to use. While maintaining the camera on a tripod and the object on the turntable, the user acquires images with different rotation angles of the table.

People are usually directed towards each other in conversations, to make it easier to hear what is being said. Algorithms for voice and speech recognition works in a similar way, regarding the microphone direction towards the sound source. In this thesis in electronics has therefore a servo control with binaural sound localization been implemented on a microcontroller connected to two microphones.When people perceive sound, the brain can estimate the sound source direction by comparing the time taken by the sound reaching one ear to the other [1]. The difference in time is called the interaural time difference, and can be calculated using various techniques. An exploratory comparison between the techniques cross-correlation and cross-spectrum analysis was carried out before implementation.

The development in electronics increases the demand for good design methods and design tools in the field of electrical engeneering. To improve their design methods Ericsson Microwave Systems AB is interested in using computer tools to create a link between the specification and the implementation of a digital system in a FPGA. Xilinx System Generator for DSP is a tool for implementing a model of a digital signalprocessing algorithm in a Xilinx FPGA. To evaluate Xilinx System Generator two testcases has been designed. The testcases are selected to represent the FPGA designs made at Ericsson Microwave Systems.

These studies are done in behalf of Saab AB AVITRONICS in Järfälla in the form of a thesis atthe Royal Institute of Technology in Stockholm.The task was to examine the parameters that plays a role in the construction of modern radomesoperating in broadband applications.This was interesting for Saab to get an indication of which way they should go at the newdevelopment of radomes for the next generation of equipment for electronic warfare.After a thorough analysis of the influencing parameters, a optimization application was made toget a automated way to get a radome design by specifying data on the radome size, airloads,materials, etc.This is to minimise the time of the laborious work that radome development.inply.This was solved by letting ANSYS calculate the strength of the radome structure and MATLABcalculate electromagnetic data and cost models of different sizes and materials.All these parameters woven together with the optimization tool modeFrontier picks data from therespective program and perform an optimization algorithm and then iterate a step and sends thisdata to calculation programs for the new input data. In the end, we have received a convergedpoint with our optimal solution.For the presumptions and limitations for which applied for this thesis, the result was prettyintuitive. That is to say that the smaller radome - the less materal is needed and lowermanufacturing costs results in the cheapest solution possible. The reality is not so simple. Whereyou have to take more of the electrical details such as the effect on the transmitter as a majorfactor..

The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.

This master?s thesis examines the possibility to heuristically optimise instruction cache performance in a Just-In-Time (JIT) compiler. Programs that do not fit inside the cache all at once may suffer from cache misses as a result of frequently executed code segments competing for the same cache lines. A new heuristic algorithm LHCPA was created to place frequently executed code segments to avoid cache conflicts between them, reducing the overall cache misses and reducing the performance bottlenecks. Set-associative caches are taken into consideration and not only direct mapped caches.

Automatic query expansion has long been studied in information retrieval research as a technique that deals with the fundamental issue of word mismatch between query and document. The purpose of this thesis is to compare the retrieval effectiveness of different strategies for automatic query expansion. The strategies are based on local analysis of the corpus and use statistical information from the local document set to extract terms that suppose to adapt themselves to each individual search and therefore appear to be searchonyms to the index terms. The strategies compared are: association clusters, metric cluster and scalar cluster. Baseline queries of 24 topics are expanded using terms from the different clusters and searches are made.

In modern industrial robots the components in the transmission contain nonlinearities. These nonlinearities need to be to estimated either for better control or to use the parameters for diagnosis of the system. There is a lot of work done within system identification and mainly within the field of iterative parameter estimation.This thesis considers recursive grey-box identification for a nonlinear model of the transmission in an industrial robot. The nonlinearities that are identified are friction, spring stiffnes, hysteresis and backlash. These nonlinearities are a part of the models that are presented in this thesis.

This essay set out to propose a problematic interpretation of the socio-cultural perspective on learning. Its purpose is to show how the socio-cultural perspective on learning defines the concept of knowledge in an incomplete way. The aim becomes then that of giving a more comprehensive description of this concept, and, to this end, to construct a new, broader pedagogic discourse. The investigation starts with a deconstructive analysis of Roger Säljö?s socio-cultural text in order to point out the incompleteness of the concept of knowledge.

The relational database model was defined in the 1970?s and is the dominating database type today.  The main difference between data from a relational database and a hierarchical data structure is that the relational database stores records in tables. The records have no particular order, but can include links in terms of relationships with other records. A hierarchical structure organizes data in the form of a tree structure  and  can for an example be found in organizational structures in which different levels involves different responsibilities. If the data stored in a relational database is to be presented in a hierarchically, a conversion of the data structure is required. The intention of this paper is to describe how such a conversion can be performed.  To investigate the conversion methods, case studies has been conducted on the basis of a specific organization?s hierarchical structure.

Facial expressions are a part of our body language that helps us to clarify the verbal communication between humans. We use our facial expressions every day, both consciously and unconsciously, to express emotions and attitudes depending on the situation. The hypothesis of the study is: Given a facial expression, how well can Microsoft Kinect, as an input method, determine a person?s feelings with the two algorithms Naive Bayes and Sequential Minimal Optimization? The feelings are limited to happy, sad, surprised and disgusted. With the help of Kinect, a person?s facial data, both coordinates of the face and parameterized data, were saved and used for machine learning.

This report evaluates whether an interpreted high-level garbage collected language has enough information about its memory behaviour to make better cache decisions than modern general CPU hardware.With a generational garbage collector, depending on promotion algorithm and generation size, around 90% of all objects never leave the first generation. This report is based on the hypothesis that, because of the low promotion rate, accesses to higher generations are sufficiently rare not to benefit from caching.To test this hypothesis, we built an operating system with a Scheme interpreter in kernel mode, where the interpreter controls the cache. Generic x86 PC hardware was used, since it allows fine-grained control of cache decisions.Measurements of execution time in this interpreter show that disabling the cache for generations higher than the first does not give any performance gain, but rather a performance loss of up to 50%.We conclude that this interpreter design is not an improvement, but cannot conclude that the hypothesis is false in general. We suggest building a better CPU simulator to gather more data from which to make better caching decisions, moving internal interpreter data structures into the garbage collected heap and modifying the hardware to allow control in the currently rigid dimension of where data is cached---for example separate control of instruction and data caches and separate data caches for different areas of memory..

This report is about how HDR (HighDynamicRange) can be created and used in combination with Tone mapping. This work has been carried out together with Kapsch TrafficCom AB in Jönköping.The objective of this project is to:Evaluate and investigate the effects given to pictures by HDR and tone mapping.Evaluate if the technology may lead to improvements in Kapsch?s systems.To construct a program which is able to handle some form of tone mapping or HDR-algorithm.These questions will be answered in this report:What kind of effects has HDR and tone mapping-algorithms on pictures?Can the HDR-technology give better data in Kapsch?s systems?The research method used in this report is called action research. This means the authors has investigated the technology by reading different documentations and by testing different algorithms to see what kind of result they give. The report describes some of the tests made to see if the technology is appropriate in Kapsch?s system.There is two smaller reports made by the authors which documenting some of the work.The first report describes the work with different settings for a camera to create pictures with HDR-quality.

The purpose of this MSc thesis is to examine the retrieval effectiveness of two Web search engines with queries from the academic discipline of Classical Studies. The two search engines are chosen to represent two different types Google as a broad general search engine and Argos as a specialised search engine for the subject of Classical Studies. The search engines are compared for precision among the first twenty results returned for thirty queries. In order to avoid bias in the study, the queries are based on real users' information needs. Due to the subjective character of the concept of relevance, the study is performed with five different experiments with five different definitions of relevance.