International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper discusses the design and development of the EUVE Virtual Environment (EVE) system. The EVE system is being developed as an interactive virtual reality (VR) viewing tool for NASA's Extreme Ultraviolet Explorer (EUVE) satellite. EVE will serve as a predictive tool for forecasting spacecraft constraint violations and will provide a capability for spacecraft problem analysis and resolution in realtime through visualization of the problem components in the spacecraft. EVE will animate, in three-dimensional realtime, the spacecraft dynamics and thermal characteristics of the EUVE spacecraft. EVE will also display the field of view for the science instrument detectors, star trackers, sun sensors, and both the omni and high-gain antennas for NASA's Tracking and Data Relay Satellite System (TDRSS) and for possible ground station contact. EVE will display other vital spacecraft information to support the routine operations of the EUVE spacecraft. The EVE system will provide three quick-look visualization functions: (1) to model in-orbit data for realtime spacecraft problem analysis and resolution, (2) to playback data for post-pass data analysis, and training exercises, and (3) to simulate data in the science planning process for optimum attitude determination and to predict spacecraft and thermal constraint violations. We present our preliminary design for a telemetry server, providing both realtime and post pass data, that uses standard Unix utilities. We also present possibilities for future integration of the EVE system with other software to automate the science planning and command generation functions of the satellite operations.

<p>Today we are very much dependent on different kinds of real time systems. Usually,a real time system is a system which is interacting with a physical environmentwith sensors or activators. There are many advantages by replacing mechanicalcomponents with electrical ones. For instance, it is usually cheaper and possibleto add new functions to the device without replacing the electronic part, whichwould have been necessary with a mechanical one.The possibility of simulating a distributed system is used throughout the vehi-cle industry. With the simulation of connected sub systems, using modeled busesand real time kernels, one could increase the correctness of the behavior of the sys-tem and consequently decrease the amount of time spent later in the developingprocess.In this master thesis we used modeled CAN-buses and real time models tosimulate the connection and execution time of the systems. The simulation resultsare used to validate the functionality of the distributed system. Additionally, aworst-case response time analysis is made to set timing constraints on the systemto fulfill given deadlines.During the work, different settings of the network are tested to analyze thesystem frequency needed to sustain deadlines and correctness on the network.</p>

In recent years, multiresolution models have progressed substantially. At the beginning, discrete models were employed in graphics applications, due mainly to the low degree of complexity involved in implementing them, which is the reason why nowadays they are still used in applications without high graphics requirements. Nevertheless, the increase in realism in graphics applications makes it necessary to use multiresolution models which are more exact in their approximations, which do not call for high storage costs and which are faster in visualization. This has given way to continuous models, where two consecutive levels of detail only differ by a few polygons and where, additionally, the duplication of information is avoided to a considerable extent, thus improving on the spatial cost offered by most discrete models.Advances have been made in the use of new graphics primitives which minimize the data transfer between the CPU and the GPU, apart from trying to make use of the connectivity information given by a polygonal mesh. For this purpose, graphics primitives with implicit connectivity, such as triangle strips and triangle fans, have been developed. Many continuous models based on this type of primitives have been recently developed. In these last few years, graphics hardware performance has evolved outstandingly, giving rise to new techniques which allow the continuous models to accelerate even more. In this work, we have improved the interactive render of polygonal meshes. To tackle the problem, we firstly studied fundamental techniques to efficiently render polygonal meshes and we later made use of geometry simplification and level of detail techniques. Thus, we defined a multiresolution model that represents a polygonal mesh at any given resolution. This approach is able to manage continuous level-of-detail by smoothly adapting mesh resolution to the application requirements. Moreover, the model was modified to take the maximum advantage of the recent GPU features. We also created a modified version of the model for being used in deforming meshes. Finally, we developed an independent library to integrate our model in real-time applications.

The main goal in this thesis is to select and test Forward Error Correction (FEC) schemes suitable for network video transmission over RTP/UDP. There is a general concern in communication networks which is to achieve a tradeoff between reliable transmission and the delay that it takes. Our purpose is to look for techniques that improve the reliability while the realtime delay constraints are fulfilled. In order to achieve it, the FEC techniques focus on recovering the packet losses that come up along any transmission. The FEC schemes that we have selected are Parity Check algorithm, ReedSolomon (RS) codes and a Convolutional code. Simulations are performed to test the different schemes. The results obtained show that the RS codes are the more powerful schemes in terms of recovery capabilities. However they can not be deployed for every configuration since they go beyond the delay threshold. On the other hand, despite of the Parity Check codes being the less efficient in terms of error recovery, they show a reasonable low delay. Therefore, depending on the packet loss probability that we are working with, we may chose one or other of the different schemes. To summarize, this thesis includes a theoretical background, a thorough analysis of the FEC schemes chosen, simulation results, conclusions and proposed future work.

The aim of this study was to access the efficacy of an enhanced in situ bioremediation technology at a 1,2-dichloroethane (1,2-DCA) polluted site in southern Taiwan. A water-soluble substrate was injected into the groundwater to provide carbon sources for microbial growth. After substrate injection, increased total organic carbon (TOC) concentrations and microbial populations including Dehalococcoides spp. and Desulfitobacterium spp. were observed in the groundwater. Microbial diversity was analyzed using denaturing gradient gel electrophoresis (DGGE) and 16S rDNA sequencing to identify the bacterial strains. The results showed that after 4.5 months of substrate injection, the reduction-oxidation potential (ORP) changed from aerobic to anaerobic conditions. The less oxygen-tolerable 1,2-DCA degrading bacteria Dehalococcoides spp. started to accumulate in groundwater. However, the more oxygen-tolerable Desulfitobacterium spp. didn¡¦t show a prominent change, although the ORP was suitable for Desulfitobacterium spp. to carry out reductive dechlorination. The DGGE results indicate that with the injected carbon sources and mineral nutrients, both the groundwater microbial diversity and the amount of dominant bacteria were increased. The 16S rDNA sequencing demonstrated that the amount and diversity of 1,2-DCA degradation-related bacteria also increased with the injection of substrate. Six groups of 1,2-DCA degradation related reactions were found: dechlorination, chlorinated-compound degradation, denitrification, iron-reduction, sulfate-reduction and methane-utilizing. Four species that can directly degrade 1,2-DCA were found: Dehalobacter sp., Dehalococcoides sp., Nitrosospira sp. and Pseudomonas sp. Moreover, 11 methane-utilizing bacterial species were also discovered. The presence of these methane-utilizing bacteria not only might assist the process of denitrification and sulfate-reduction, but also could diminish the emission of the greenhouse gas. The results of this study confirmed that the addition of substrates could affect the groundwater oxidation-reduction state and enhance the bioremediation at the 1,2-DCA-contaminated site. Thus, enhanced in situ bioremediation is a feasible technology for site remediation.

<p>Event-triggered real-time systems are desirable to use in environments where the arrival of events are hard to predict. The semantics of an event-triggered system is well mapped to the behaviour of an active database management system (ADBMS), specified using event-condition-action (ECA) rules. The benefits of using an active database, such as persistent data storage, concurrency control, timely response to event occurrences etc. highlights the need for a development method for event-triggered real-time systems using active databases.</p><p>However, there are problems left to be solved before an ADBMS can be used with confidence in real-time environments. The behaviour of a real-time system must be predictable, which implies a thorough analysed specification with e.g. specified worst case execution times. The predictability requirement is an obstacle for specifying real-time systems as ECA rules, since the rules may affect each other in many intricate ways which makes them hard to analyse. The interaction between the rules implies that it is not enough to verify the correctness of single rules; an analysis must consider the behaviour of the entire rule set.</p><p>In this dissertation, an approach for developing active applications is presented. A method is examined which starts with an analysed high-level timed automaton specification and transforms the specified behaviour into an implicitly analysed rule set. For this method to be useful, the transformation from timed automata to rules must preserve the exact behaviour of the high level specification. Hence, the aim of this dissertation is to verify transformations between timed automaton specifications and ECA rules.</p><p>The contribution of this project is a structured set of general transformations between timed automata specifications and ECA rules. The transformations include both transformations of small timed automata constructs for deterministic environments and formally verified timed automata patterns specifying the behaviour of composite events in recent and chronicle context.</p>

<p>The main goal in this thesis is to select and test Forward Error Correction (FEC) schemes suitable for network video transmission over RTP/UDP. There is a general concern in communication networks which is to achieve a tradeoff between reliable transmission and the delay that it takes. Our purpose is to look for techniques that improve the reliability while the realtime delay constraints are fulfilled. In order to achieve it, the FEC techniques focus on recovering the packet losses that come up along any transmission. The FEC schemes that we have selected are Parity Check algorithm, ReedSolomon (RS) codes and a Convolutional code. Simulations are performed to test the different schemes.</p><p>The results obtained show that the RS codes are the more powerful schemes in terms of recovery capabilities. However they can not be deployed for every configuration since they go beyond the delay threshold. On the other hand, despite of the Parity Check codes being the less efficient in terms of error recovery, they show a reasonable low delay. Therefore, depending on the packet loss probability that we are working with, we may chose one or other of the different schemes. To summarize, this thesis includes a theoretical background, a thorough analysis of the FEC schemes chosen, simulation results, conclusions and proposed future work.</p>

The nature of visual properties used for object perception in mid- and high-level vision areas of the brain is poorly understood. Past studies have employed simplistic stimuli probing models limited in descriptive power and mathematical under-pinnings. Unfortunately, pursuit of more complex stimuli and properties requires searching through a wide, unknown space of models and of images. The difficulty of this pursuit is exacerbated in brain research by the limited number of stimulus responses that can be collected for a given human subject over the course of an experiment. To more quickly identify complex visual features underlying cortical object perception, I develop, test, and use a novel method in which stimuli for use in the ongoing study are selected in realtime based on fMRI-measured cortical responses to recently-selected and displayed stimuli. A variation of the simplex method controls this ongoing selection as part of a search in visual space for images producing maximal activity — measured in realtime — in a pre-determined 1 cm3 brain region. I probe cortical selectivities during this search using photographs of real-world objects and synthetic “Fribble” objects. Real-world objects are used to understand perception of naturally-occurring visual properties. These objects are characterized based on feature descriptors computed from the scale invariant feature transform (SIFT), a popular computer vision method that is well established in its utility for aiding in computer object recognition and that I recently found to account for intermediate-level representations in the visual object processing pathway in the brain. Fribble objects are used to study object perception in an arena in which visual properties are well defined a priori. They are constructed from multiple well-defined shapes, and variation of each of these component shapes produces a clear space of visual stimuli. I study the behavior of my novel realtime fMRI search method, to assess its value in the investigation of cortical visual perception, and I study the complex visual properties my method identifies as highly-activating selected brain regions in the visual object processing pathway. While there remain further technical and biological challenges to overcome, my method uncovers reliable and interesting cortical properties for most subjects — though only for selected searches performed for each subject. I identify brain regions selective for holistic and component object shapes and for varying surface properties, providing examples of more precise selectivities within classes of visual properties previously associated with cortical object representation. I also find examples of “surround suppression,” in which cortical activity is inhibited upon viewing stimuli slightly deviation from the visual properties preferred by a brain region, expanding on similar observations at lower levels of vision.

Hår är en av de första märkbara aspekterna av vårt utseende och förmedlar indirekt många första intryck. Att ta hand om, klippa och dekorera hår är något som har varit med människor sedan historia började dokumenteras. Det är ett unikt drag hos människan och kan symbolisera religion, yrke, social status, identitet eller till och med hälsotillstånd. Hårfärger är uppfattade med en viss personlighet och över hela världen finns det flera olika genetiska egenskaper för hårets egenskaper och struktur. När man arbetar med berättande är håret en väldigt viktig del av designen och om den är välgjord kan den få liv och en egen identitet. I datorgrafikens värld finns det många sätt för en konstnär att skapa de delar som behövs för ett realistiskt hår. Det som ser trovärdigt ut kan dock vara väldigt individuellt för betraktaren, varje attribut uppfattas lite annorlunda från person till person. I slutändan är det upp till konstnären att bemästra en egen metod för att skapa en frisyr som går ihop med den konstnärliga visionen. / Hair is one of the first noticeable aspects of our appearances and will convey many indirect first impressions. Grooming and decorating hair is something that have been with humans since documented history. It is a unique human trait that can symbolize religion, occupation, social status, identity or even health itself. Hair colors are conceived with a certain personality to them and throughout the world there exists several different genetic attributes to hairs structure and texture. When working with storytelling, the hair is thus a very important part of the design, and if done well can live beyond the character in the story. In the world of computer graphics there are many ways in which an artist can create the parts necessary for an approach to realistic looking hair. What looks realistic can be very individual to the viewer, each visual trait looking somewhat different to each pair of eyes, and each method will also probably produce a different result. In the end, it is up to the artist to learn how to control the methods available and to create a hairstyle in line with the artistic vision.

Multi-Processor System on Chip (MPSoC) consisting of multiple processing cores connected via a Network on Chip (NoC) has gained prominence over the last decade. Most common way of mapping applications to MPSoCs is by dividing the application into small tasks and representing them in the form of a task graph where the edges connecting the tasks represent the inter task communication. Task scheduling involves mapping task to processor cores so as to meet a specified deadline for the application/task graph. With increase in system complexity and application parallelism, task communication times are tending towards task execution times. Hence the NoC which forms the communication backbone for the cores plays a critical role in meeting the deadlines. In this thesis we present an approach to synthesize a minimal network connecting a set of cores in a MPSoC in the presence of deadlines. Given a task graph and a corresponding task to processor schedule, we have developed a partitioning methodology to generate an efficient interconnection network for the cores. We adopt a 2-phase design flow where we synthesize the network in first phase and in second phase we perform statistical analysis of the network thus generated. We compare our model with a simulated annealing based scheme, a static graph based greedy scheme and the standard mesh topology. The proposed solution offers significant area and performance benefits over the alternate solutions compared in this work.