In this thesis, opti-acoustic stereo imaging, which is the deployment of two-dimensional (2D) high frequency imaging sonar with the electro-optical camera in calibrated stereo configuration, is studied. Optical cameras give detailed images in clear waters. However, in dark or turbid waters, information coming from electro-optical sensor is insufficient for accurate scene perception. Imaging sonars, also known as acoustic cameras, can provide enhanced target details under these scenarios. To illustrate these visibility conditions, a 2D high frequency imaging sonar simulator as well as an underwater optical image simulator is developed. A computationally efficient algorithm is also proposed for the post-processing of the returned sonar signals. Where optical visibility allows, integration of the sonar and optical images effectively provides binocular stereo vision capability and enables the recovery of three-dimensional (3D) structural information. This requires solving the feature correspondence problem for these completely different sensing modalities. Geometrical interpretation of this problem is examined on the simulated optical and sonar images. Matching the features manually, 3D reconstruction performance of opti-acoustic system is also investigated. In addition, motion estimation from opti-acoustic image sequences is studied. Finally, a method is proposed to improve the degraded optical images with the help of sonar images. First, a nonlinear mapping is found to match local the features in opti-acoustical images. Next, features in the sonar image is mapped to the optical image using the transformation. Performance of the mapping is evaluated for different scene geometries.

The purpose of this study is to explain how the value of sawn wood changes when sawn wood are cut in 30 respective 60 cm lengths. The raw material into the saw mill will mainly be bucked in 30 cm and 60 cm modules. There will also be two alternatives where the timber will be bucked special lengths, 370, 490 and 550 cm but also in 490 and 550 cm. The method used for the study is to simulate both cutting and sawing the woods. For cutting the simulator Timan is used and for sawing the simulator Timberopt is used. When data is generated from the simulators, calculations of some key figures is done and also how much the revenue need to be increased for the sawn wood in order to cover for the increased costs of changing sawn wood from 30 cm to 60 cm modules The conclusion is that the single biggest reason, impacting the value of the sawn wood is the cutting at the saw mill. When going from 30 to 60 cm modules, the impact will be that the customers to the saw mill must pay more to increase the revenue by at least 10% for the sawn wood in order to justifice the change in production. It is also possible to increase the value of the products further by bucking the timber in three lengths, 370, 490 and 550 cm, in order to get 12 % increase of the share of longer sawn wood (>= 480 cm). / Syftet med studien är att förklara hur värdet på sågad vara förändras när den avkapas i 30 respektive 60 cm moduler. Råvaran in till sågverket kommer huvudsakligen att apteras i 30 cm respektive 60 cm moduler. Det kommer också att finnas två alternativ där timret apteras i speciallängderna 370, 490 och 550 cm, samt 490 och 550 cm. Metoden som användes i studien är att simulera såväl aptering som avkapning. För aptering i skogen användes simulatorn Timan. För sönderdelning och avkap på sågverket användes simulatorn Timberopt. När data genererats från simulatorerna har också beräkning av vissa nyckeltal gjorts, samt beräkningar på hur mycket intäkterna för den sågade varan behöver öka för att täcka värdeminskningen av en omläggning av sågad vara från 30 cm till 60 cm moduler. Slutsatsen är att den största, enskilda posten till minskat värde uppstår vid avkapet i justerverket. Vid en övergång från 30 cm till 60 cm moduler, blir konsekvensen att kunderna till sågverket måste vara beredda att betala minst 10% mer för att täcka värdeminskningen vid omläggning till 60 cm moduler. Det är också möjligt att öka värdet på produkten ytterligare genom att aptera timret i två långa och en kort längd, dvs 370, 490 och 550 cm. Då fås en ökning med ca 12% av sågad vara som överstiger 480 cm i längd.

Due to their promise for supporting applications society cares about and their unique blend of distributed systems and networking issues, wireless sensor networks (SN) have become an active research area. Most current SN use an arrangement of nodes with limited capabilities. Given SN device technology trends, we believe future SN nodes will have the computational capability of today's handhelds, and communication capabilities well beyond today's 'motes'. Applications will demand these increased capabilities in SN for performing computations in-network on higher bit-rate streaming data. We focus on interesting fusion applications such as automated surveillance. These applications combine one or more input streams via synthesis, or fusion, operations in a hierarchical fashion to produce high-level inference output streams. For SN to successfully support fusion applications, they will need to be constructed to achieve application throughput and latency requirements while minimizing energy usage to increase application lifetime. This thesis investigates novel middleware mechanisms for improving application lifetime while achieving required latency and throughput, in the context of a variety of SN topologies and scales, models of potential fusion applications, and device radio and CPU capabilities. We present a novel architecture, DFuse, for supporting data fusion applications in SN. Using a DFuse implementation and a novel simulator, MSSN, of the DFuse middleware, we investigate several middleware mechanisms for managing energy in SN. We demonstrate reasonable overhead for our prototype DFuse implementation on a small iPAQ SN. We propose and evaluate extensively an elegant distributed, local role-assignment heuristic that dynamically adapts the mapping of a fusion application to the SN, guided by a cost function. Using several studies with DFuse and MSSN, we show that this heuristic scales well and enables significant lifetime extension. We propose and evaluate with MSSN a predictive CPU scaling mechanism for dynamically optimizing energy usage by processors performing fusion. The scaling heuristic seeks to make the ratio of processing time to communication time for each synthesis operation conform to an input parameter. We show how tuning this parameter trades latency degradation for improved lifetime. These investigations demonstrate MSSN's utility for exposing tradeoffs fundamental to successful SN construction.

<p>The purpose of this study is to explain how the value of sawn wood changes when sawn wood are cut in 30 respective 60 cm lengths. The raw material into the saw mill will mainly be bucked in 30</p><p>cm and 60 cm modules. There will also be two alternatives where the timber will be bucked special lengths, 370, 490 and 550 cm but also in 490 and 550 cm.</p><p>The method used for the study is to simulate both cutting and sawing the woods. For cutting the simulator Timan is used and for sawing the simulator Timberopt is used. When data is generated</p><p>from the simulators, calculations of some key figures is done and also how much the revenue need to be increased for the sawn wood in order to cover for the increased costs of changing sawn wood</p><p>from 30 cm to 60 cm modules</p><p>The conclusion is that the single biggest reason, impacting the value of the sawn wood is the cutting at the saw mill.</p><p>When going from 30 to 60 cm modules, the impact will be that the customers to the saw mill must pay more to increase the revenue by at least 10% for the sawn wood in order to justifice the change</p><p>in production.</p><p>It is also possible to increase the value of the products further by bucking the timber in three lengths, 370, 490 and 550 cm, in order to get 12 % increase of the share of longer sawn wood (>= 480 cm).</p> / <p>Syftet med studien är att förklara hur värdet på sågad vara förändras när den avkapas i 30 respektive 60 cm moduler. Råvaran in till sågverket kommer huvudsakligen att apteras i 30 cm respektive 60 cm moduler. Det kommer också att finnas två alternativ där timret apteras i speciallängderna 370, 490 och 550 cm, samt 490 och</p><p>550 cm.</p><p>Metoden som användes i studien är att simulera såväl aptering som avkapning. För aptering i skogen användes simulatorn Timan. För sönderdelning och avkap på sågverket användes simulatorn Timberopt. När data genererats från simulatorerna har också beräkning av vissa nyckeltal gjorts, samt beräkningar på hur mycket intäkterna för den sågade varan behöver öka för att täcka värdeminskningen av en omläggning av sågad vara från 30 cm till 60 cm moduler.</p><p>Slutsatsen är att den största, enskilda posten till minskat värde uppstår vid avkapet i justerverket.</p><p>Vid en övergång från 30 cm till 60 cm moduler, blir konsekvensen att kunderna till sågverket måste vara beredda att betala minst 10% mer för att täcka värdeminskningen vid omläggning till 60 cm moduler.</p><p>Det är också möjligt att öka värdet på produkten ytterligare genom att aptera timret i två långa och en kort längd, dvs 370, 490 och 550 cm. Då fås en ökning med ca 12% av sågad vara som överstiger 480 cm i längd.</p>

Made available in DSpace on 2014-12-17T14:55:51Z (GMT). No. of bitstreams: 1 MarceloHRN_DISSERT.pdf: 1910960 bytes, checksum: 696b69a0c65216fcf9b33e58073b32ab (MD5) Previous issue date: 2012-08-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This dissertation describes the implementation of a WirelessHART networks simulation module for the Network Simulator 3, aiming for the acceptance of both on the present context of networks research and industry. For validating the module were imeplemented tests for attenuation, packet error rate, information transfer success rate and battery duration per station / Esta disserta??o descreve a implementa??o de um m?dulo de simula??o para redes WirelessHART, utilizando o simulador de redes Network Simulator 3, tendo em vista a aceita??o que ambos possuem no atual contexto de pesquisa e na ind?stria. Para valida??o do m?dulo foram implementados testes quanto a atenua??o dos sinais transmitidos, probabilidade de perda pacotes (Packet Error Rate PER), probabilidade de que uma informa??o produzida seja recebida no destino e dura??o da bateria nas esta??es

The use of simulation in aircraft development and pilot training is essential as it saves time and money. The ARINC 610C standard describes simulator functionality, and is developed to streamline the use of flight simulators. However, the text based standard lacks overview and function descriptions are hard to understand for the simulator developers, who are the main users. In this report, an educational software tool is conceptualised to increase usability of ARINC 610C. The usability goals and requirements were established through multiple interviews and two observation studies. Consequently, six concepts were produced, and evaluated in a workshop with domain experts. Properties from the evaluated concepts were combined in order to form one concluding concept. A prototype was finally developed and evaluated in usability tests with the potential user group. The results from the heuristic evaluation, the usability tests, and a mean system usability score of 79.5 suggests that the prototyped system, developed for visualising ARINC 610C, is a viable solution.

I denna rapport presenteras hur en simulatorlösning för funktionstestning av en gruvmaskin har tagits fram. Arbetet har skett i Atlas Copcos regi och består av tre delar: kartläggning i form av intervjuer, utvärdering av befintliga simulatoralternativ och slutligen val och implementation av lösning.   Resultatet visar på en konceptuell prototyp, där en gruvmaskin visualiseras i en 3D-miljö tillsammans med en virtuell gruvgång. Detta möjliggör bland annat testning av autonom navigering, alltså att en gruvmaskin självständigt styr utifrån avläsning av tunnelväggar med hjälp av laser. Samtidigt tillåter lösningen också att kontrollvärden från olika sensorer, såsom vinkelgivare, kan hämtas ut ur simuleringen. / This report presents how a solution for functional testing of mine trucks involving a simulator has been developed. The project has been directed by Atlas Copco and consists of three parts: conduction of a survey in the form of interviews, evaluation of existing simulators and finally selection and implementation of a solution.   The result shows a mine truck visualized in a 3D environment with a virtual mining tunnel. This allows for testing of the autonomous navigation systems developed at Atlas Copco, where a machine uses readings from laser sensors to locate itself and navigate through mining tunnels without the help of an operator. At the same time, it allows relevant and interesting values from various sensors, such as inclinometers, to be extracted from the simulation environment.

The South African National Defence Force (SANDF) currently requires a system of systems simulation capability for supporting the different phases of a Ground Based Air Defence System (GBADS) acquisition program. A non-distributed, fast-as-possible simulator and its architectural predecessors developed by the Council for Scientific and Industrial Research (CSIR) was able to provide the required capability during the concept and definition phases of the acquisition life cycle. The non-distributed simulator implements a 100Hz logical time Discrete Time System Specification (DTSS) in support of the existing models. However, real-time simulation execution has become a prioritised requirement to support the development phase of the acquisition life cycle. This dissertation is about the ongoing migration of the non-distributed simulator to a practical simulation architecture that supports the real-time requirement. The simulator simulates a synthetic environment inhabited by interacting GBAD systems and hostile airborne targets. The non-distributed simulator was parallelised across multiple Commod- ity Off the Shelf (COTS) PC nodes connected by a commercial Gigabit Eth- ernet infrastructure. Since model reuse was important for cost effectiveness, it was decided to reuse all the existing models, by retaining their 100Hz logical time DTSSs. The large scale and event-based High Level Architecture (HLA), an IEEE standard for large-scale distributed simulation interoperability, had been identified as the most suitable distribution and parallelisation technology. However, two categories of risks in directly migrating to the HLA were iden- tified. The choice was made, with motivations, to mitigate the identified risks by developing a specialised custom distributed architecture. In this dissertation, the custom discrete time, distributed, peer-to-peer, message-passing architecture that has been built by the author in support of the parallelised simulator requirements, is described and analysed. It reports on empirical studies in regard to performance and flexibility. The architecture is shown to be a suitable and cost effective distributed simulator architecture for supporting a speed-up of three to four times through parallelisation of the 100 Hz logical time DTSS. This distributed architecture is currently in use and working as expected, but results in a parallelisation speed-up ceiling irrespective of the number of distributed processors. In addition, a hybrid discrete-time/discrete-event modelling approach and simulator is proposed that lowers the distributed communication and time synchronisation overhead—to improve on the scalability of the discrete time simulator—while still economically reusing the existing models. The pro- posed hybrid architecture was implemented and its real-time performance analysed. The hybrid architecture is found to support a parallelisation speed- up that is not bounded, but linearly related to the number of distributed pro- cessors up to at least the 11 processing nodes available for experimentation. / Dissertation (MSc)--University of Pretoria, 2009. / Computer Science / unrestricted

Beim Einsatz mobiler Arbeitsmaschinen bestimmt der Maschinenführer die Arbeitsleistung und -sicherheit wesentlich mit. Er muss in die Lage versetzt werden, die Maschine ohne Gefahr für sich und andere zu steuern und ihr Leistungspotential voll zu nutzen. Deshalb sind Maschinenführer als reale oder virtuelle Bediener frühzeitig in die Maschinenentwicklung mit einzubeziehen. In einem global härter werdenden Markt reichen den Herstellern empirische Untersuchungen allein nicht mehr aus. Die Zusammenhänge im System Bediener-Maschine-Prozess sollen möglichst objektiv und reproduzierbar erfasst werden. Das kann aufwändige experimentelle Untersuchungen erfordern. Der Bau realer Testmaschinen und ihre Ausstattung mit Messtechnik kosten viel Zeit und Geld. Reale Einsatzversuche sind oft nicht unter gleich bleibenden Bedingungen durchführbar, was die Auswertung erschwert. Hingegen bieten Werkzeuge der Simulation und Virtuellen Realität eine effiziente Möglichkeit, Maschinenführer in frühen Phasen der Produktentwicklung mit einzubeziehen.

A visão de muitas pessoas sobre uma colônia de formigas, em geral, é de que estes pequenos e inofensivos insetos somente se movem aleatoriamente para coletar alimento e conservá-los em seus ninhos. Um olhar destreinado não conseguiria notar o nível de complexidade e organização que é requerido por uma colônia de formigas para sua sobrevivência. Uma formiga simples é parte de um grande grupo que coopera entre si para criar um superorganismo. Sem uma autoridade central ou indivíduos com habilidade de um pensamento cognitivo complexo, a colônia se auto-organiza, e, de fato, ajusta seus recursos de uma maneira muito eficiente. Essa dissertação investiga o papel da comunicação indireta nas tarefas de exploração e forrageamento, e como isso afeta as decisões de um agente simples e traz um comportamento emergente útil à toda colônia. Por fim, este trabalho implementa uma plataforma de simulação multi-agente inspirado em formigas / Most people\'s view of an ant colony and ants in general is that they simply pose harmless little insects that move randomly and gather food in their underground nests. The untrained eye would have never guessed the level of complexity and organisation that is required in order for an ant colony to survive. The simple ant is a part of a huge group, which cooperate one superorganism. Without any central authority or the ability of complex cognitive thought from the individuals, the colony seems to self organise and in fact adjust its resources in a quite efficient way. This dissertation investigates the role of indirect communication in the exploration and forage task and how it affects the decisions of the single agent and brings an emergent behaviour that is useful to all the colony. Finally this work implements an ant inspired multi-agent simulation plataform