<p>Shading is a technique that is used in computer graphics to make faceted objects appear smooth and more realistic. In the research presented in this thesis we have investigated how shading can be generated as efficiently as possible without sacrificing quality.</p><p>In the classical approach to high quality shading proposed by Phong, the illumination equation is computed per pixel using an interpolated normal. The normals at the vertices are bi-linearly interpolated over the polygon to obtain a normal per pixel. Correct shading requires normalization of these normals, which is computationally demanding involving a square root. In our research we have shown how this normalization can be eliminated through the use of spherical interpolation and the Chebyshev recurrence formula, reducing the calculation to a few single arithmetic operations per pixel.</p><p>Still a substantial setup operation is needed for each scanline. We have studied how also this can be made more efficient, with some limited progress so far. An alternative approach is to do the most of the setup on polygon level and incrementally compute the setup needed per scanline. In particular, we have studied quadratic shading approaches, i.e. fitting second degree surfaces to the polygons. The most successful approach has been through what we have called X-shading, where the setup is calculated by using an efficient approximation for the mid-edge normals. This setup is about four times faster than previously known methods.</p><p>In the process of studying shading methods we have also made some contributions to improving bump-mapping and simulation of different kinds of light sources.</p><p>The developed methods will be of interest in future generations of computer graphics software and hardware systems, ranging from high end systems to generate realistic movies and 3D games, to handheld devices such as mobile phones with graphics displays.</p>

Shading is a technique that is used in computer graphics to make faceted objects appear smooth and more realistic. In the research presented in this thesis we have investigated how shading can be generated as efficiently as possible without sacrificing quality. In the classical approach to high quality shading proposed by Phong, the illumination equation is computed per pixel using an interpolated normal. The normals at the vertices are bi-linearly interpolated over the polygon to obtain a normal per pixel. Correct shading requires normalization of these normals, which is computationally demanding involving a square root. In our research we have shown how this normalization can be eliminated through the use of spherical interpolation and the Chebyshev recurrence formula, reducing the calculation to a few single arithmetic operations per pixel. Still a substantial setup operation is needed for each scanline. We have studied how also this can be made more efficient, with some limited progress so far. An alternative approach is to do the most of the setup on polygon level and incrementally compute the setup needed per scanline. In particular, we have studied quadratic shading approaches, i.e. fitting second degree surfaces to the polygons. The most successful approach has been through what we have called X-shading, where the setup is calculated by using an efficient approximation for the mid-edge normals. This setup is about four times faster than previously known methods. In the process of studying shading methods we have also made some contributions to improving bump-mapping and simulation of different kinds of light sources. The developed methods will be of interest in future generations of computer graphics software and hardware systems, ranging from high end systems to generate realistic movies and 3D games, to handheld devices such as mobile phones with graphics displays.

This dissertation provides constructive proof, through the implementation of a middleware, that distribution transparency is practical, generic, and extensible. Fault tolerant distributed services can be developed by using the failure detection abilities of the middleware. By generic we mean that the middleware can be used for many different programming languages and paradigms. Distribution for each kind of language entity is done in terms of consistency protocols, which guarantee that the semantics of the entities are preserved in a distributed setting. The middleware allows new consistency protocols to be added easily. The efficiency of the middleware and the ease of integration are shown by coupling the middleware to a programming system, which encompasses the object oriented, the functional, and the concurrent-declarative programming paradigms. Our measurements show that the distribution middleware is competitive with the most popular distributed programming systems (JavaRMI, .NET, IBM CORBA). / QC 20101029

Nature is rich in examples of how vision can be successfully used for sensing and perceiving the world and how the gathered information can be utilized to perform a variety of different objectives. The key to successful vision is the internal representations of the visual agent, which enable the agent to successfully perceive properties about the world. Humans perceive a multitude of properties of the world through our visual sense, such as motion, shape, texture, and color. In addition we also perceive the world to be structured into objects which are clustered into different classes - categories. For such a rich perception of the world many different internal representations that can be combined in different ways are necessary. So far much work in computer vision has been focused on finding new and, out of some perspective, better descriptors and not much work has been done on how to combine different representations. In this thesis a purposive approach in the context of a visual agent to object recognition is taken. When considering object recognition from this view point the situatedness in form of the context and task of the agent becomes central. Further a multiple feature representation of objects is proposed, since a single feature might not be pertinent to the task at hand nor be robust in a given context. The first contribution of this thesis is an evaluation of single feature object representations that have previously been used in computer vision for object recognition. In the evaluation different interest operators combined with different photometric descriptors are tested together with a shape representation and a statistical representation of the whole appearance. Further a color representation, inspired from human color perception, is presented and used in combination with the shape descriptor to increase the robustness of object recognition in cluttered scenes. In the last part, which contains the second contribution, of this thesis a vision system for object recognition based on multiple feature object representation is presented together with an architecture of the agent that utilizes the proposed representation. By taking a system perspective to object recognition we will consider the representations performance under a given context and task. The scenario considered here is derived from a fetch scenario performed by a service robot. / QC 20101129

Strong mobility enables migration of entire computations combining code, data, and execution state (such as stack and program counter) between sites of computation. This is in contrast to weak mobility were migration is confined to just code and data. Strong mobility is essential for many applications where reconstruction of execution states is either difficult or even impossible. Typical application areas are load balancing, reduction of network latency and traffic, and resource-related migration, just to name a few. This thesis presents a model, programming abstractions, an implementation, and an evaluation of thread-based strong mobility. The model extends a distributed programming model based on automatic synchronization via dataflow variables. The programming abstractions capture various migration scenarios. These scenarios differ in how migration source and destination relate to the site initiating migration. The implementation is based on replication of concurrent lightweight threads between sites controlled by migration managers. The model is implemented in the Mozart programming system. The first version is complete and a work concerning resource rebinding is still in progress. / QC 20101130

När du som designer får i uppdrag att designa ett system där det finns ett flertal olika målgrupper av användare uppstår en komplex situation som måste hanteras. I denna rapport härleds en sådan situation från start till mål där jag som designer med hjälp av metoden mock upskapar ett system åt Fagersta Golfklubb, där man som läsare får följa med och läsa hur användarna reflekterat över designen och se steg för steg hur jag som designer har tolkat användarnas reflektioner för att uppnå en passande design. En empirisk studiehar även gjortsdär målgrupperna som används under designprocessendefinieras. Efter att ha gjort flertalet tester på personer som kantänkas använda systemet kan jag konstatera att designen inte alls ser ut som den design jag själv tänkte ut från början. Det låg en stor utmaning i att de vitt skilda målgrupperna har haft olika synsätt på hur designen ska se ut och fungera, och att jag som designer måsteanpassa designen utifrån allas behov. När den som designar arbetar mot flera målgrupper är det flera olika upplevelser som designern måste ta i beräkningen, för attdesignen ska bli välgenomarbetat och anpassad utifrån många olika vinklar. Om jag jämför användarsidanmot den administrativa sidan var den administrativa sidan betydligt enklare att designa då det var endast en målgrupp den berörde. Slutligen avslutas rapporten med de resultat jag fått under mitt arbete som jag hoppas kan vara till hjälp för någon som ska bygga ett system som riktar sig till flera olika slag av målgrupper. / When you as a designer is commissioned to design a system where there are several different groups of users a complex situation emerge that the designer must handle. In this report,such a situationis derivedfrom start to finish where I as a designer,with the help of the method mock up,createsa system to Fagersta Golfclub, where the reader can follow along and learn how people thought about the design and see step by step how I as a designer has interpreted the users' reflections to achieve a suitable design. Also, an empirical study has been carriedout,where the target groups which are used during the design processare defined. After doing several tests on people who may use the system, I can conclude that the design does not at all look like the design I myself thought out from the beginning. It was challenging that the different target groups had such different views on how the design will look and work, and that I as a designer had to customize the design according to everyone's needs. When thedesignerwork with respect to several target groups, there are severalexperiences that the designer must take into accountin order to make the design well-made and appropriatefrom many different angles. If I compare the user side to the administrative side, the administrative side was considerably easier to design,since it was only one much more uniform target group concerned. Finally, the report ends with the results I got frommy work,which I hope may be helpful forsomeone who will build a system where there are several target groups involved.

<p>The purpose of the research is to analyze collaboration and communication in distributed teams working together through ICT (Information and Communication Technology), to provide an overview and a broader understanding of important areas that require consideration. The analysis is from an organizational, psychosocial and managerial perspective, with the aim to support the development of strategies and the creation of more efficient and pleasant distributed work environments. Research questions concern the psychosocial work environment; differences, problems and opportunities for distributed teams, with deeper analysis of areas that was demonstrated particularly difficult. The analysis is concretized into advice to guide distributed teams; common problem areas are pointed out and an attempt on a theoretical model of distributed project work is made. A solid ground for continued research in the area as well as possibilities to support distributed teams is provided.</p><p>The research was mainly conducted in globally distributed project courses at a university level, where students communicated and collaborated through ICT. The results apply on distributed projects, but can also be relevant for other areas in the new ICT facilitated work environment. The research has been conducted by investigating how team members behave in and perceive distributed work environments; analyzing how i.e. variations in organization, work, social activities and behavior affect how well the collaboration and communication work</p><p>Teams working in distributed projects go through the same stages and encounter the same problems as any other team. Some problems become harder to overcome, there are new obstacles, at the same time as other problems become less noticeable and new opportunities arise. The base for collaboration and communication changes when team members don't see each other regularly. Teams are entailed to use ICT for basically all communication and various media demands alterations in behavior, as well as it alters the relation between senses and how people perceive things. Distributed team members don't have the same awareness of each other and get fewer cues to interpret situations and handle teambuilding, motivational problems and conflicts. Several of the regular ways to start socializing, build trust and get a common base for understanding and collaboration are not present in a distributed environment. There is no physical team space to meet in and team members don't "see" each other on a regular basis.</p><p>It is possible to successfully work in distributed teams without regular face-to-face meetings even if it is more intricate. It will always be different, and the big danger is believing that it won't. Working in distributed teams is not necessarily worse, but there are no effortless solutions for replacing face-to-face encounters. Distributed projects require effort, but conducted right it can be a rewarding experience that brings an extra dimension to the project work. To make distributed projects work well it is necessary to consider technological issues as well as their effects on individuals. It is essential to understand the new issues people encounter when moving to a distributed work environment and the interrelations between different areas and variables.</p>

<p>The purpose of this work is to providing a general set of base classes for building simulators, for example a robot system. Instead of every time building a new simulator from the beginning, you get the already completed components from a library. The library should in that way act as a springboard for development.</p><p>To do this work, there’s a lot of knowledge required in how a general robot system could look like. Therefore it was necessary to gather some information about robotics. </p><p>On the basis of what the information gave, two different user cases were built. From these user cases, the components were fetched, which was supposed to be included in the library. </p><p>The result of this work leads to a number of classes, which describes the components. A simple test program is also done, which handles the components. To get the classes more useful, the com-ponents must be broken down in much smaller parts. The operations on the classes should also be more realistic than what has been achieved in this work.</p>

<p>During the work at Gateway Security AB in Motala I began examining available antenna models to get a wider perspective, this have given knowledge of their structure, and an understanding of their function. All my necessary fact is based on my observations and notes of these measurings. </p><p>New antenna models, and available models were examined where measurements at different heights and different distances on the antenna were performed with the help of an oscilloscope and a measure probe, peak – to - peak was brought on the signal. The measurements are presented in a line diagram. </p><p>Further development of simulating tool for antenna designs have been made. Calculations of electromagnetic fields from the antenna take place in the simulation programme Wire-MoM, where the antenna is fed in as a thread structure. I used the data from this programme to present the appearance graphical in 2-dimension in Matlab. Further development represents an improvement of the result presentation management of the simulating tool. </p><p>The results are presented graphical and show the fields at a height of for example 1 meter. Conclusions where taken on the basis of comparison of my results from all the measurements and the graphical image.</p>

<p>This report is a degree project performed at Freudenberg Household Products AB, (FHP). </p><p>The degree project comprises measurement and analysis of the power net at FHP Basproduction. The content is divided between one theory-part, one document- part with measurements and also conclusions and a list of measures to be taken. </p><p>During the project the purpose and restriction change from a quality investigation to only concentrate on harmonics and finding the reason why they exist, and also to find a solution to the problem with harmonics. </p><p>The measurements shows that the power net contains harmonics of different order and intensity. High harmonic rate is found under the transformer T-7. </p><p>The problem with harmonics was not known earlier and therefore it can be assumed that there are more built-in frequency converters without filter in pumps, compressors and machines in the whole net. After a number of measurements one can suppose that some parts of the FHP power net is unstable. In an unstable weak power net frequency converters produce a large number of harmonics. In all the cases where large numbers of harmonics have been detected the trace has ended in a power central where a pump, compressor or heating element is. </p><p>Worth to be noticed is that under the same transformer there are strip lights, converters and control electronics. </p><p>The conclusion is that measures against harmonics are possible and necessary to do in most cases. The measures should be made local, as close to the disturbing object as possible, to stop the disturbance to get out in the net. The aim is that the current should stay sinus. </p><p>The purpose with the project could not be fulfilled because the report do not tell about how serious the high number of current harmonics are for running the factory. The opinion is that the harmonics should be reduced to a lower level.</p>