Energy efficiency and network lifetime are key factors in characterizing wireless sensor networks due to the nodes having a finite and exhaustible source of energy. Due to the nodes limited energy, it is vital to have the node functioning for as long as possible otherwise it will render the technology futile. Transmission is the most energy consuming activity a node undertakes, therefore by decreasing the number of unnecessary transmissions, the energy consumption in the nodes decreases significantly. In order to reduce unnecessary transmissions, energy-efficient data dissemination techniques have been developed to deliver the data using the minimum number of necessary transmissions. The topic of this thesis is to develop a routing protocol that will extend the network lifetime by introducing cognition to routing. Cognitive routing is an approach to make nodes more intelligent by utilizing information from the lower layers and network in order to make more informant decisions. Data from the physical layer can relay important information about the state of the node, its neighbors, and the surrounding environment hence enabling the node to make energy-efficient and aware decisions. The routing protocol formulates an energy profile, a channel profile and a traffic profile in order to make adapted and intelligent decisions. Diversity routing is used to increase the reliability of transmissions in the network to reduce unnecessary transmissions as communication is the primary reason for energy consumption in wireless sensor networks. Combining these two approaches in one protocol allows for cognitive routing to operate based on energy constraints obtained from the lower levels hence optimizing the process yielding a longer network lifetime. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-08-25 11:27:09.887

During the underwater vehicle R&D process, a crucial task in the beginning phase is to decide the specifications of sensors and actuators. The designers need to make decisions if an off-the-shelf product will meet the requirement, or more efforts should be devoted to the development of a component. The communication format undertaken between the controller and the subsystems is another important design issue worth of close attention. Once these specifications are settled, it will be very troublesome to change them afterwards in case a design flaw is discovered. It will be even worse if the problems are found after the prototype vehicle is constructed. In order to ensure the flexibility and shorten the development time, this paper proposes an architecture for general-purpose low level controller suitable for underwater vehicles. We suggest using the idea of ¡§tiers¡¨ to construct a vehicle controller with multiple layers. Generally speaking, there are many different paths of information flow in a vehicle control system. It can be high-level tier and abstractive intention of the human operator interpreted by the man-machine interface; or the mid-level tier control commands to maneuver the vehicle to a specific direction; down to the low -level tier as the raw commands fed to the thrusters. The performance and the reliability of the system deeply depend on the flow of these information and commands. High- and mid-level tiers information can be modeled mathematically, but the low-level tier is product-dependent. In other words, once a new sensor or actuator is installed, the control software related to these components need to be revised accordingly. The modification of the software might exist at multiple places if the structure is not organized as tiers. In order to maintain full flexibility of the vehicle controller structure throughout the R&D period, the high- and mid-level will be implemented in the man-machine interface for ROV case, and in the mission planner in the AUV case. The low-level tier is implemented in the onboard computer. The onboard low-level controller covers a variety of communication format of physical ports, such as serial line, D/A, A/D, D/IO and PWM. Port setting parameters, such baud-rate or DA range, can be specified remotely on the surface. The physical connecting ports of the sensors can be changed freely without rewiring or reprogramming. Taking the stability of the controller as the top priority, we used DOS operating system as the platform to implement our concepts. DOS has been in the market for more than two decades, but it has the merits of fast in booting, highly stable, efficient in computation. We use its timer interrupt service INT 0X1C to construct a realtime thread to poll the readiness of sensory channels, and uploads the data to the surface via a channel-driven packet. The packets delivered to the surface are split into channels and reconstructed back to their original raw data format. The other necessary service routines, such as DA, AD and DIO, are also embedded inside this thread for its promptitude. We constructed an experimental platform with this low-level controller to verify if the vehicle alitude control can be accurate enough as the carrier of the Seafloor Laser Scanner developed by our lab. Prior to the experiments, issues, such as whether the bouyancy of the system is pro or con for driving the vechile, were studied with Simulink. The poorness of altitude control caused by the deadzone effect of the thruster failed to be duplicated as in the simulation, while the alitude control gave a tracking error within ¡Ó 5cm.

The purpose of this paper is to design a laser scanning system for a high temperature and acidic environment to measure small-scale surface roughness of seabed and to collect information related to calcium carbonate debris. The study comprises two parts. One is to construct the hardware and software of the laser scanning system. Two is to test the system at sea. The system were tested at Kuishantao sea area, an area with many submarine springs. The temperature of the hot water from the submarine springs can be as high as 126¢XC. Key substances from this type of hot springs are surfur and air bubbles composed of CO2, N2, O2, SO2, and H2S. These chemicals make the sea water in this area acidic, and the pH value can be less than 2. In other words, this sea area is a high temperature and very acidic environment According the acidic resistant test result, the researchers decided to use Polypropylene (PP) as the material. The laser scanning system captures information automatically, and it uses industrial single board computer (PC104) as the control platform. The researchers selected red laser, which is monotonous, directional, and coherent Lithium batteries, can be recharged repetitively, were used to supply the power. High-precision positioning, high resolution, and with easy speed and angle control stepping motors were chosen for the system. For the software, the researchers chose the Window operating system. The hardware and software of this system are highly compatible. Operating the system is very intuitive because windows are used as the interface, and the hardware has high supporting capacity. This arrangement makes data analysis later on very convenient. Images acquired from conducting the actual experiment at sea that need to be processed. A CCD camcorder with fixed location and angle was used to capture images. With the high brightness characteristic of laser and simple threshold values for screening, the researchers got the pixel position of laser beans. Then a calibrated the camcorder was used to switch the pixel coordinates to obtain the actual size of the object.

Wireless sensor networks (WSNs) are composed of hundreds of wireless sensors which collaborate to perform a common task. Because of the small size of wireless sensors, they have some serious limitations including very low computation capability and battery reserve. Such resource limitations require that WSN protocols to be extremely efficient. In this thesis, we focus on the Medium Access Control (MAC) layer in WSNs. We propose a MAC scheme, V-MAC, for WSNs that extends that lifetime of the network. We compare V-MAC with other MAC schemes. V-MAC uses a special mechanism to divide sensors in different groups and then all the members of a group go to sleep at the same time. V-MAC protects WSNs against denial of sleep and broadcast attacks. We present the V-MAC scheme in details and evaluate it with simulations. Our simulations show that V-MAC enjoys significantly higher throughput and network lifetime compared to other schemes.

Aujourd’hui l’électronique fait partie intégrante de nos vies. En effet, de plus en plus d’objets intègrent de l’électronique permettant de les connecter, on appelle cela l’internet des objets (IoT). Tous ces dispositifs disposent d’une connectivité sans fil, rendant ainsi indispensable l’intégration d’une ou plusieurs antennes. De plus, l’électronique devant s’adapter à des objets de plus en plus petits et flexibles embarquant de plus en plus de capteurs tout en consommant de moins en moins d’énergie, il est intéressant de se pencher sur l’étude de nouveaux matériaux pour la réalisation d’antennes devant s’adapter à ces nouvelles contraintes. Dans ce cadre, nous nous sommes attachés dans ce travail de recherche, à la conception de structures antennaires à base de métaux liquides à température ambiante dans le but de réaliser des antennes conformables de formes complexes associant l’impression 3D, des antennes reconfigurables et des structures rayonnantes ayant la capacité de capteur. Dans ce manuscrit des prototypes d’antenne comportant ces caractéristiques ont été simulés, réalisés et mesurés. / Today, electronic is an integral part of our lives. Indeed, more and more objects integrate electronics to connect each other, this is the Internet of Things (IoT). All of these wireless devices need one or more antennas. Furthermore, It’s useful to develop new materials to realize new antennas that fit with new constraints: smaller and flexible objects, more and more sensors and less and less consuming.In this context, we have focused this research on antenna structures based on metals which are liquid at room temperature to realize conformable antennas of complex shapes combining 3D printing, reconfigurable antennas and radiant structures with the ability to sensor. In this manuscript, antenna prototypes with these characteristics have been simulated, realized and measured.

No description available.

A wireless sensor network (WSN) is a spatially distributed network used to monitor the physical and environmental conditions such as temperature, pressure, sound, humidity, heat, etc. WSNs can be modeled using different simulation frameworks like OMNeT++, Prowler, Atarraya, PiccSIM, Network Simulator, etc. In this research, Simulink framework was used to model WSN system. The complete WSN consisting of transmitting nodes, communication channel, and receiver nodes are built in the Simulink framework. Orthogonal frequency division multiplexing technique was used to transmit the information. The implemented wireless sensor system behavior is studied using temperature as the measurement parameter at different values of signal to noise ratio. The plots of bit error rate versus signal to noise ratio and frame error rate versus signal to noise ratio are generated in the Simulink framework. It is easy to study the effect of different physical layer parameters on the performance of wireless sensor networks by implementing WSN in the Simulink framework.

No description available.

Así surge el problema materia de la presente investigación, cuyo punto de vista básico es que, hay algunos puntos de contacto en la acción causada por el dictador en las dos novelas, pero también hay algunas diferencias, que dan a cada una de las novelas un carácter peculiar. El objeto de este estudio es hacer un análisis comparativo de ciertas consecuencias producidas por la acción del "señor Presidente," en las novela El señor Presidente, y de Antón Bocanegra, en la novela Muertes de perro. Para que los terminos de comparacion se coloquen en un plano factible y lógico, se partirá del punto de vista que las dos novelas tratan de un tema común, la dictadura, pero bajo estructuras, procedimientos, métodos, y recursos utilizados diferentes.

Background: Joint injuries are a complex matter. Due to the low blood flow to the tendons and ligaments, they take months or even years to heal; some fail to heal. This can be devastating for the elite athlete as well as for the labour worker or everyday person. Today, the devices that can detect an upcoming inflammation or injury, cost 15 000 US dollars and more. A cheaper technology would increase the access. This project is investigating the possibility to detect an upcoming inflammation through measuring the local skin temperature. Method: A model of an arm was built in Comsol Multiphysics, where a tennis elbow (lateral epicondylitis) was simulated through local temperature increase. Clinical tests were pursued on two healthy subjects, in order to gain knowledge on how the skin temperature behaves on healthy subjects. Results: At an internal temperature increase in the LE of 0.25 K, a temperature difference on the skin of 0.18 K was detected in the model. The clinical tests on healthy subjects indicated a correlation between the temperatures on and around the elbow joint. Discussion: The model results does not include any error sources, such as deviation in room temperature and factors affecting the subject´s body temperature, such as time of day, eating and exercising routines. The clinical tests show a pattern of the temperature distribution on and around the elbow joint, in healthy subjects. The fact that a pattern is present, is a presumption enabling to find deviations, caused by upcoming inflammation. Conclusion: The model is indicating that a local temperature increase in the LE is detectable at the skin surface. The clinical test indicates that the noise in the temperature data of a healthy person, is small enough to enable to detect a local temperature deviation. At a local skin temperature increase of more than 0.5 K, the results are indicating that the deviation is detectable. Analysing the model data, 0.5 K in skin temperature increase would mean a local temperature increase at the LE of approximately 0.7 K. This is before the stage of inflammation according to literature, which occurs at an increase of 1.5 to 2.2 K. Further studies would be interesting to make, in purpose of developing an affordable device that can detect if an inflammation is about to occur, and thereby enable the subject to stop the course. A prototype should be developed in order to make tests on more subjects. The equine industry is also a target group – the prototype may therefore be developed to fit both humans and horses. / Bakgrund: Ledskador är komplicerade. På grund av det låga blodflödet till senor och ligament, tar de månader eller år att läka; visa skador läker aldrig helt. Det här kan vara förödande för såväl elitatleter som arbetande och gemene man. Tekniker idag som kan detektera uppkommande inflammation eller skada, kostar 15 000 US dollar och mer. En billigare teknik skulle ha en större tillgänglighet. Det här projektet undersöker möjligheten att detektera en uppkommande inflammation genom att mäta den lokala skintemperaturen. Metod: En modell av en arm byggdes i Comsol Multiphysics, där en tennisarmbåge (lateral epikondylit) simulerades genom en lokal temperaturökning. Kliniska tester utfördes på två friska subjekt, för att skapa en bil av hur skintemperaturen varierar på friska personer. Resultat: Vid en inner temperaturökning om 0,25 K i LE, uppmättes en temperaturökning på huden om 0,18 K i modellen. De kliniska testerna på friska subjekt indikerade att en korrelation finns mellan temperaturerna på och runt armbågsleden. Diskussion: Resultat från modellen saknar felkällor, som exempelvis variation av rumstemperatur och andra faktorer som påverkar subjektets kroppstemperatur, som tid på dagen, mat- och träningsrutiner.De kliniska testerna uppvisar ett mönster av temperaturdistributionen hos friska subjekt på och runt armbågsleden. Att ett mönster finns, banar väg för att hitta avvikelser, som orsakas av uppkommande inflammation. Slutsats: Modellen indikerar att en lokal temperaturökning i LE är mätbar på huden. Det kliniska testet indikerar att bruset i temperaturdistributionen hos ett friskt subjekt, är litet nog för att möjliggöra detektion av en lokal temperaturavvikelse. Vid en lokal ökning av hudtemperatur med mer än 0,5 K, indikerar resultaten att avvikelsen är detekterbar. Vid analys av modellresultaten, innebär 0,5 K hudtemperatursökning en temperaturökningi LE om ungefär 0,7 K. Det är innan inflammation har brutit ut, som sker vid en ökning om 1,5 till 2,2 K. Vidare studier är intresssant att göra, i ändamål att utveckla en prisvärd produkt som kan detektera om en inflammation är på väg, och därigenom göra det möjligt för subjektet att stoppa förloppet. En prototyp behöver utvecklas för att kunna utföra tester på fler subjekt. Utöver människor, är hästindustrin en målgrupp – prototypen bör därför utvecklas för att passa båda grupperna.