• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1261
  • 687
  • 2
  • Tagged with
  • 1952
  • 1948
  • 1946
  • 203
  • 200
  • 188
  • 174
  • 156
  • 141
  • 139
  • 122
  • 111
  • 94
  • 93
  • 83
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
601

Model-based User Interface Design

Trætteberg, Hallvard January 2002 (has links)
This work is about supporting user interface design by means of explicit design representations, in particular models. We take as a starting point two different development traditions: the formal, analytic, topdown engineering approach and the informal, synthetic, bottom-up designer approach. Both are based on specific design representations tailored to the respective approaches, and are found to have strengths and weaknesses. We conclude that different representations should be used during user interface design, based on their specific qualities and the needs of the design process. To better understand the use of design representations a framework for classifying them is developed. A design representation may be classified along three dimensions: the perspective (problem- or solution-oriented) of the representation, the granularity of the objects described and the degree of formality of the representation and its language. Any design approach must provide representation languages that cover the whole classification space to be considered complete. In addition, the transitions between different representations within the representation space must be supported, like moving between task-based and interaction- oriented representations or up and down a hierarchic model. Movements between representations with different degrees of formality are particularly important when combining user-centered design with a model-based approach. The design representation classification framework has guided the development of diagrambased modelling languages for the three main perspectives of user interface design, tasks, abstract dialogue and concrete interaction. The framework has also been used for evaluating the languges. A set-based conceptual modelling language is used for domain modelling within all these perspectives. The task modelling language is designed as a hybrid of floworiented process languages and traditional hierarchical sequence-oriented task languages. Key features are tight integration with the domain modelling language, expressive and flexible notation and support for classification of task structures. The language for modelling abstract dialogue is based on the interactor abstraction for expressing composition and information flow, and the Statecharts language for activation and sequencing. Parameterized interactors are supported, to provide means of expressing generic and reusable dialogue structures. Modelling of concrete interaction is supported by a combination of the dialogue and domain modelling languages, where the former captures the functionality and behavior and the latter covers concepts that are specific for the chosen interaction style. The use of the languages in design is demonstrated in a case study, where models for tasks, dialogue and concrete interaction are developed. The case study shows that the languages support movements along the perspective, granularity and formality dimensions.
602

Feasibility study: Implementation of a gigabit Ethernet controller using an FPGA

Fält, Richard January 2003 (has links)
<p>Background: Many systems that Enea Epact AB develops for theirs customers communicates with computers. In order to meet the customers demands on cost effective solutions, Enea Epact wants to know if it is possible to implement a gigabit Ethernet controller in an FPGA. The controller shall be designed with the intent to meet the requirements of IEEE 802.3. </p><p>Aim: Find out if it is feasible to implement a gigabit Ethernet controller using an FPGA. In the meaning of feasible, certain constraints for size, speed and device must be met. </p><p>Method: Get an insight of the standard IEEE 802.3 and make a rough design of a gigabit Ethernet controller in order to identify parts in the standard that might cause problem when implemented in an FPGA. Implement the selected parts and evaluate the results. </p><p>Conclusion: It is possible to implement a gigabit Ethernet controller using an FPGA and the FPGA does not have to be a state-of-the-art device.</p>
603

Mixed RTL and gate-level power estimation with low power design iteration / Lågeffektsestimering på kombinerad RTL- och grind-nivå med lågeffekts design iteration

Nilsson, Jesper January 2003 (has links)
<p>In the last three decades we have witnessed a remarkable development in the area of integrated circuits. From small logic devices containing some hundred transistors to modern processors containing several tens of million transistors. However, power consumption has become a real problem and may very well be the limiting factor of future development. Designing for low power is therefore increasingly important. To accomplice an efficient low power design, accurate power estimation at early design stage is essential. The aim of this thesis was to set up a power estimation flow to estimate the power consumption at early design stage. The developed flow spans over both RTL- and gate-level incorporating Mentor Graphics Modelsim (RTL-level simulator), Cadence PKS (gate- level synthesizer) and own developed power estimation tools. The power consumption is calculated based on gate-level physical information and RTL- level toggle information. To achieve high estimation accuracy, real node annotations is used together with an own developed on-chip wire model to estimate node voltage swing. </p><p>Since the power estimation may be very time consuming, the flow also includes support for low power design iteration. This gives efficient power estimation speedup when concentrating on smaller sub- parts of the design.</p>
604

Interactive Visualization of Statistical Data using Multidimensional Scaling Techniques

Jansson, Mattias, Johansson, Jimmy January 2003 (has links)
<p>This study has been carried out in cooperation with Unilever and partly with the EC founded project, Smartdoc IST-2000-28137. </p><p>In areas of statistics and image processing, both the amount of data and the dimensions are increasing rapidly and an interactive visualization tool that lets the user perform real-time analysis can save valuable time. Real-time cropping and drill-down considerably facilitate the analysis process and yield more accurate decisions. </p><p>In the Smartdoc project, there has been a request for a component used for smart filtering in multidimensional data sets. As the Smartdoc project aims to develop smart, interactive components to be used on low-end systems, the implementation of the self-organizing map algorithm proposes which dimensions to visualize. </p><p>Together with Dr. Robert Treloar at Unilever, the SOM Visualizer - an application for interactive visualization and analysis of multidimensional data - has been developed. The analytical part of the application is based on Kohonen’s self-organizing map algorithm. In cooperation with the Smartdoc project, a component has been developed that is used for smart filtering in multidimensional data sets. Microsoft Visual Basic and components from the graphics library AVS OpenViz are used as development tools.</p>
605

Social Agent: Facial Expression Driver for an e-Nose

Widmark, Jörgen January 2003 (has links)
<p>This thesis describes that it is possible to drive synthetic emotions of an interface agent with an electronic nose system developed at AASS. The e-Nose can be used for quality control, and the detected distortion from a known smell sensation prototype is interpreted to a 3D-representation of emotional states, which in turn points to a set of pre-defined muscle contractions. This extension of a rule based motivation system, which we call Facial Expression Driver, is incorporated to a model for sensor fusion with active perception, to provide a general design for a more complex system with additional senses. To be consistent with the biologically inspired sensor fusion model a muscle based animated facial model was chosen as a test bed for the expression of current emotion. The social agent’s facial expressions demonstrate its tolerance to the detected distortion in order to manipulate the user to restore the system to functional balance. Only a few of the known projects use chemically based sensing to drive a face in real-time, whether they are virtual characters or animatronics. This work may inspire a future android implementation of a head with electro active polymers as synthetic facial muscles.</p>
606

Free Software For Web Development / Fri mjukvara för webbutveckling

Linder, Anders, Olsson, Johan January 2003 (has links)
<p>This thesis will look into what kind of solutions a company or a private person can use if they want to create a dynamic website using only free software. To do this we divided our work in two parts. In the first part, we developed a dynamic website for a Swedish company. On the server side we used exclusively free software with open source code. There are different meanings in how the term “free” should be used when referring to software, which we will explain in the thesis. We have also chosen to work with the XMLtechnology to see if it lives up to its expectations and to see if we could benefit from the technology. Alongside with the development of our site, another company developed a site for the same company as us, by using non-free software. We have described both implementations and compared them to see if it is possible to do the same thing with both free and non-free software. </p><p>The investigating part of our work consisted of getting information about what other people think about the free software phenomenon. To do so we created an online questionnaire where we randomly picked 100 Swedish web agencies and asked them to answer 8 questions about what kind of software they used in their company, and what they thought about free software. To get some more opinions we also interviewed two persons involved in these kinds of topics. Jan Sandred, who is a well known expert advisor in topics concerning the Information Technology area and Richard Stallman, the founder of GNU and the Free Software Movement. </p><p>The reason for dividing the thesis in two parts was to get an overall picture on the subject. We did not only want to base our results on other people’s thoughts. We wanted to make our own conclusions based on the implementation we did. This approach showed out to be very good. We got to try working with free software ourselves to see its pros and cons and build our own opinions about it. We could then proceed to compare our impressions to other people’s impressions about free software.</p>
607

Embedded Computer for Space Applications suitable for Linux / Linuxanpassad inbyggnadsdator för rymdbruk

Dahlberg, Johan January 2003 (has links)
<p>This report briefly describes the special requirements for a computer board for use in space. In particular, component selection and ways of mitigating the soft and hard errors are discussed. Furthermore, one implementation for a low-cost, relatively high performance computer that will work in the harsh space environment is presented. The report is primarily intended for those familiar with digital design, who need an introduction to construction of space or other high-reliability hardware. </p><p>As the quality (resolution) of imagers, spectrometers and other data sources in scientific satellite payloads is increasing, there is also an increasing demand for more processing power in order to compress or in other way process the data before transmitting it on the limited bandwidth microwave downlink to Earth. Scientific instruments are usually mission specific and have rather low budget, so there is a need for a powerful computer board that can be used for a number of missions in order to keep the engineering costs down.</p>
608

Matting of Natural Image Sequences using Bayesian Statistics

Karlsson, Fredrik January 2004 (has links)
<p>The problem of separating a non-rectangular foreground image from a background image is a classical problem in image processing and analysis, known as matting or keying. A common example is a film frame where an actor is extracted from the background to later be placed on a different background. Compositing of these objects against a new background is one of the most common operations in the creation of visual effects. When the original background is of non-constant color the matting becomes an under determined problem, for which a unique solution cannot be found. </p><p>This thesis describes a framework for computing mattes from images with backgrounds of non-constant color, using Bayesian statistics. Foreground and background color distributions are modeled as oriented Gaussians and optimal color and opacity values are determined using a maximum a posteriori approach. Together with information from optical flow algorithms, the framework produces mattes for image sequences without needing user input for each frame. </p><p>The approach used in this thesis differs from previous research in a few areas. The optimal order of processing is determined in a different way and sampling of color values is changed to work more efficiently on high-resolution images. Finally a gradient-guided local smoothness constraint can optionally be used to improve results for cases where the normal technique produces poor results.</p>
609

Colour proof quality verification

Sundell, Johanna January 2004 (has links)
<p>BACKGROUND </p><p>When a customer delivers a colour proof to a printer, they expect the final print to look similar to that proof. Today it is impossible to control if a match between proof and print is technically possible to reach at all. This is mainly due to the fact that no information regarding the production circumstances of the proof is provided, for instance the printer does not know which proofer, RIP or ICC-profile that was used. Situations where similarity between proof and print cannot be reached and the press has to be stopped are both costly and time consuming and are therefore wished to be avoided.</p><p>PURPOSE </p><p>The purpose of this thesis was to investigate the possibility to form a method with the ability control if a proof is of such good quality that it is likely to produce a print that is similar to it.</p><p>METHOD </p><p>The basic assumption was that the quality of a proof could be decided by spectrally measuring known colour patches and compare those values to reference values representing the same patches printed at optimal press conditions. To decide which and how many patches that are required, literature and reports were studied, then a test printing and a comparison between proofing systems were performed. To be able to analyse the measurement data in an effective way a tool that analyses the difference between reference and measurement data was developed using MATLAB. </p><p>RESULT </p><p>The result was a suggestion for a colour proof quality verification method that consists two parts that are supposed to complement each other.The first one was called Colour proofing system evaluation and is supposed to evaluate entire proofing systems. It consists of a test page containing colour patches, grey balance fields, gradations and photographs. The second part is called Colour proof control and consists of a smaller set of colour patches that is supposed to be attached to each proof. </p><p>CONCLUSIONS </p><p>The method is not complete since more research regarding the difference between measurement results and visual impression is needed. To be able to obtain realistic tolerance levels for differences between measurement- and reference data, the method must be tested in every-day production. If this is done the method is thought to provide a good way of controlling the quality of colour proofs.</p>
610

Navigation, Visualisation and Editing of Very Large 2D Graphics Scenes

Kempe, Marcus, Åbjörnsson, Carl January 2004 (has links)
<p>The project has been carried out at, and in association with, Micronic Laser Systems AB in Täby, Sweden. Micronic Laser Systems, manufacture laser pattern generators for the semiconductor and display markets. Laser pattern generators are used to create photomasks, which are a key component in the microlithographic process of manufacturing microchips and displays. </p><p>An essential problem to all modern semiconductor manufacturing is the constantly decreasing sizes of features and increasing use of resolution enhancement techniques (RET), leading to ever growing sizes of datasets describing the semiconductors. When sizes of datasets reach magnitudes of hundreds of gigabytes, visualisation, navigation and editing of any such dataset becomes extremely difficult. As of today this problem has no satisfying solution. </p><p>The project aims at the proposal of a geometry engine that effectively can deal with the evergrowing sizes of modern semiconductor lithography. This involves a new approach to handling data, a new format for spatial description of the datasets, hardware accelerated rendering and support for multiprocessor and distributed systems. The project has been executed without implying changes to existing data formats and the resulting application is executable on Micronics currently existing hardware platforms. </p><p>The performance of the new viewer system surpasses any old implementation by a varying factor. If rendering speed is the comparative factor, the new system is about 10-20 times faster than its old counterparts. In some cases, when hard disk access speed is the limiting factor, the new implementation is only slightly faster or as fast. And finally, spatial indexing allow some operations that previously lasted several hours, to complete in a few seconds, by eliminating all unnecessary disk-reading operations.</p>

Page generated in 0.0426 seconds