International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / There has been much interest recently in the possibility of using the NASA Tracking and Data Relay Satellite System (TDRSS) instead of proprietary ground stations in supporting small space payload communications. These payloads operate on fairly low power and do not use the sophisticated tracking equipment standard on more complex user spacecraft. This paper is part of a feasibility study for such use of TDRSS, and focuses on the effect of the method of providing the Grade-2 data link layer services specified in Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations upon a hypothetical spacecraft using a MIL-STD-1553B polled data bus as the backbone of its onboard LAN. In particular, one case in which the 1553B bus controller, assumed to be some Intel 80X86 microprocessor, provides all CCSDS services will be contrasted with another where these services are split between the bus controller and a device which interfaces between the spacecraft LAN and the TDRSS Return Service spacelink. The comparison will be made for a 15 orbit/day scenario using a small helical antenna with a comparatively wide beamwidth. The main performance criteria considered here are end-to-end data throughput and expected delays, along with required buffer sizes for the LAN. Also, it may be noted that the data rate of the TDRSS return link and the size of the sliding window used for flow and error control will have a large impact on the required values for the chosen criteria, and so choices for these parameters significantly affect the outcome of any system service comparison. The two LAN types will be modeled and analyzed using NETWORK II.5. This simulator allows tracking of the number of packets read into LAN memories and sent down from the payload to ground via TDRSS, as well as accurately modeling the delays involved with data processing and transmission over the link.

Les travaux de recherche menés dans le cadre de cette thèse concernent l'amélioration du débit et de la qualité de service dans les réseaux sans fil basés sur les standards de la famille 802.11. Des simulations exhaustives ont été menées pour l'analyse et l'évaluation des performances des protocoles de routages réactifs AODV, DSR et DYMO ainsi que des protocoles de routage proactifs DSDV, FSR et OLSR. Plusieurs paramètres ont été considérés comme la mobilité des noeuds la charge du réseau et la mise à l'échelle. Nous pouvons observer que la métrique de qualité de lien est un paramètre important dans toute stratégie de routage. L'objectif du présent travail est de proposer une analyse comparative des différents protocoles de routage, basée sur les métriques de qualité de lien et de proposer une nouvelle métrique permettant d'améliorer le routage en termes de routage et de délai bout-en-bout. Dans la disparité des métriques proposées dans la littéraire, la métrique ETX (Expected Transmission Count) a été largement utilisée. Aussi, nous focaliserons, principalement, sur les métriques basées sur ETX. Notre constatation est que les besoins en termes de qualité de service dans les réseaux sans fil multi-saut, sont affecté entre autre par le protocole de routage adopté et la métrique de lien utilisée. Cependant, ceci est aussi strictement lié à la qualité des canaux de communication au niveau physique et l'état des files d'attente au niveau MAC. Aussi, une nouvelle métrique de qualité de lien est proposée, basée sur ETX et appelée IBETX (Interference and Bandwidth Adjusted ETX). Cette nouvelle métrique prend en considération les effets de l'interférence et de l'impact de l'état de la couche MAC sur les performances des liens de communication. Des simulations ont été conduites sous NS-2 afin de montrer l'intérêt de la métrique utilisée. Ainsi IBETX améliore le débit efficace de 19% par rapport à ETX et de 10% par rapport à ETP (Expected Throughput). Par ailleurs, la métrique proposée réduit le délai bout en bout de 16% par rapport à ELP ( Expected Link Performance) et de 24% par à ETX / This dissertation endeavors to contribute enhancements in goodputsof the IEEE 802.11-based Wireless Multi-hop Networks (WMhNs).By performing exhaustive simulations, for the deep analysis and detailed assessment of both reactive (AODV, DSR, DYMO) and proactive (DSDV, FSR, OLSR) protocols for varying mobilities, speeds, network loads and scalabilities, it is observed that a routing link metric is a significant component of a routing protocol. In addition to finding all available paths, the fastest end-to-end route is selected by a link metric for the routing protocol. This study aims the quality routing. In the class of quality link metrics, Expected Transmission Count (ETX) is extensively used. Thus, the most recently proposed ETX-based metrics have been analyzed. Though, newly developed metrics over perform ETX but still they can be improved. By profound analysis and particularized comparison of routing protocols depending upon their classes (reactive and proactive) and ETX-based metrics, we come to realize that users always demand proficient networks. In fact, WMhNs are facing several troubles which they expect to be resolved by the routing protocol operating them. Consequently, the protocol depends upon the link metric for providing quality paths. So, we identify and analyze the requirements to design a new routing link metric for WMhNs. Because, considering these requirements, when a link metric is proposed, then : firstly, both the design and implementation of the link metric with a routing protocol become easy. Secondly, the underlying network issues can easily be tackled. Thirdly, an appreciable performance of the network is guaranteed. Keeping in view the issues of WMhNs, increasing demands of users and capabilities of routing protocols, we propose and implement a new quality link metric, Interference and Bandwidth Adjusted ETX (IBETX). As, MAC layer affects the link performance and consequently the route quality, the metric therefore, tackles the issue by achieving twofold MAC-awareness. Firstly, interference is calculated using cross-layered approach by sending probes to MAC layer. Secondly, the nominal bit rate information is provided to all nodes in the same contention domain by considering the bandwidth sharing mechanism of 802.11. Like ETX, our metric also calculates link delivery ratios that directly affect throughput and selects those routes that bypass dense regions in the network. Simulation results by NS-2 show that IBETX gives 19% higher through put than ETX and 10% higher than Expected Throughput (ETP). Our metric also succeeds to reduce average end-to-end delay up to 16% less than Expected Link Performance (ELP) and 24% less than ETX

Context. The advances in location-acquisition and mobile computing techniques have generated massive spatial trajectory data. Such spatial trajectory data accumulated by telecommunication operators is huge, analyzing the data with a right tool or method can uncover patterns and connections which can be used for improving telecom services. Forecasting trajectory data or predicting next location of users is one of such analysis. It can be used for producing synthetic data and also to determine the network capacity needed for a cell tower in future. Objectives. The objectives of this thesis is, Firstly, to have a new application for CWT (Collapsed Weighted Tensor) method. Secondly, to modify the CWT method to predict the location of a user. Thirdly, to provide a suitable method for the given Telenor dataset to predict the user’s location over a period of time.   Methods. The thesis work has been carried out by implementing the modified CWT method. The predicted location obtained by modified CWT cannot be determined to which time stamp it belongs as the given Telenor dataset contains missing time stamps. So, the modified CWT method is implemented in two different methods. Replacing missing values with first value in dataset. Replacing missing values with second value in dataset. These two methods are implemented and determined which method can predict the location of users with minimal error.   Results. The results are carried by assuming that the given Telenor dataset for one week will be same as that for the next week. Users are selected in a random sample and above mentioned methods are performed. Furthermore, RMSD values and computational time are calculated for each method and selected users.   Conclusion. Based on the analysis of the results, Firstly, it can be concluded that CWT method have been modified and used for predicting the user’s location for next time stamp. Secondly, the method can be extended to predict over a period of time. Finally, modified CWT method predicts location of the user with minimal error when missing values are replaced by first value in the dataset.

The thesis deals with the issue of causal link in disputes over compensation of damage to health with focus on medical care. The thesis consists of five chapters, which are further divided into parts. Chapter One basically describes three of the preconditions of the liability for damage to health: damage, the violation of the legal obligation and fault. This chapter mainly focuses on the violation of the legal obligation and analyses the term lege artis. An informed consent of the patient is also discussed. Chapter Two deals with causal link (causality) as it is fourth and last of the essential preconditions of the liability for damage to health in Czech civil law. Chapter Two consists of two parts, each of them examines various aspects of causality. Chapter Three characterizes some of the relevant institutes of civil proceedings such as burden of proof, standard of proof or free evaluation of evidence. One of the five parts of this chapter points out the importance of the expert evidence in this type of cases. Chapter Four analyses Australian approach to the medical negligence cases with focus on the doctrine of the loss of chance. Chapter Four provides opportunity to partially compare two different legal systems (Czech and Australian). This chapter is divided into seven parts. First five parts...

This thesis deals with the responsibility associated with the provision of health care, specifically it deals with the problem of causal link in medical disputes, its peculiarities, its obstacles related to its proving and possible ways of burden-of-proof- easement in relation to causation, including in particular the loss of chance concept. Second section of the thesis is dedicated to the brief introduction to the issue of liability, as a specific phenomenon necessary for the functioning of the human community, which is in the provision of health care represented not only by civil liability, but also by ethical disciplinary or labour liability. Legal liability is however clearly the dominant and most efficient instrument to regulate the conduct of the legal norm addressees. Legal liability, defined as secondary legal obligation, arising as a result of a breach of the primary legal obligation, is described in the third section of this thesis according to its basic structural elements. These basic structural elements are: infringement, emergence of damage, fault and finally causal link between the unlawful conduct and the damage. Crucial attention is paid to the causal link, to the specification of the causal link concept, to the requirement for level of proof in the Czech legal system and also in...

La prédiction de connexions entre objets, basée soit sur une observation bruitée, soit sur une suite d'observations est un problème d'intérêt pour un nombre d'applications allant de la conception de système de recommandation en commerce électronique et réseaux sociaux jusqu'à l'inférence de réseaux en biologie moléculaire. Ce travail présente des formulations du problème de prédiction de lien, dans les cadres statique et temporel, comme un problème régularisé. Dans le scénario statique c'est la combinaison de deux normes bien connues, la norme L1 et la trace-norme qui permet de prédire les liens, alors que dans le cas dynamique, l'utilisation d'un modèle autoregressif sur des descripteurs linéaires permet d'améliorer la qualité de la prédiction. Nous étudierons la nature des solutions des problèmes d'optimisation à la fois en termes statistique et algorithmique. Des résultats empiriques encourageant mettent en évidence l'apport de la méthodologie adoptée. / Predicting connections among objects, based either on a noisy observation or on a sequence of observations, is a problem of interest for numerous applications such as recommender systems for e-commerce and social networks, and also in system biology, for inferring interaction patterns among proteins. This work presents formulations of the graph prediction problem, in both dynamic and static scenarios, as regularization problems. In the static scenario we encode the mixture of two different kinds of structural assumptions in a convex penalty involving the L1 and the trace norm. In the dynamic setting we assume that certain graph features, such as the node degree, follow a vector autoregressive model and we propose to use this information to improve the accuracy of prediction. The solutions of the optimization problems are studied both from an algorithmic and statistical point of view. Empirical evidences on synthetic and real data are presented showing the benefit of using the suggested methods.

Mobile Ad-Hoc Network (MANET) facilitates the creation of dynamic reconfigurable networks, without centralized infrastructure. MANET routing protocols have to face high challenges like link instability, node mobility, frequently changing topologies and energy consumption of node, due to these challenges routing becomes one of the core issues in MANETs. This Thesis mainly focuses on the reactive routing protocol such as Ad-Hoc On-Demand Distance Vector (AODV) routing protocol. Reliable and Efficient Reactive Routing Protocol (RERRP) for MANET has been proposed to reduce the link breakages between the moving nodes. This scheme selects a reliable route using Reliability Factor (RF); the RF considers Route Expiration Time and Hop Count to select a routing path with high reliability and have less number of hops. The simulation result shows that RERRP outperforms AODV and enhance the packet delivery fraction (PDF) by around 6% and reduces the network routing load (NRL) by around 30%. Broadcasting in MANET could cause serious redundancy, contention, and collision of the packets. A scheme, Effective Broadcast Control Routing Protocol (EBCRP) has been proposed for the controlling of broadcast storm problem in a MANET. The EBCRP is mainly selects the reliable node while controlling the redundant re-broadcast of the route request packet. The proposed algorithm EBCRP is an on-demand routing protocol, therefore AODV route discovery mechanism was selected as the base of this scheme. The analysis of the performance of EBCRP has revealed that the EBCRP have controlled the routing overhead significantly, reduces it around 70% and enhance the packet delivery by 13% as compared to AODV. An Energy Sensible and Route Stability Based Routing Protocol (ESRSBR) have also been proposed that mainly focuses on increasing the network lifetime with better packet delivery. The ESRSBR supports those nodes to participate in the data transfer that have more residual energy related to their neighbour nodes. The proposed protocol also keeps track of the stability of the links between the nodes. Finally, the ESRSBR selects those routes which consist of nodes that have more residual energy and have stable links. The comparative analysis of ESRSBR with AODV and recently proposed routing protocol called Link Stability and Energy Aware (LSEA) routing protocol revealed that the proposed protocol ESRSBR has a significantly affect the network lifetime, increases it around 10% and 13% as compared to LSEA and AODV protocols respectively. The ESRSBR also decreases the routing overhead by 22% over LSEA and by 38% over AODV.

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This paper presents a two-stage model of optimization as a quick method to choose the best potential links for implementing urban travel demand management (UTDM) strategy like road pricing. The model is optimized by minimizing the hidden cost of congestion based on user equilibrium (MHCCUE). It forecasts the exact amount of flows and tolls for links in user equilibrium condition to determine the hidden cost for each link to optimize the link selection based on the network congestion priority. The results show that not only the amount of total cost is decreased, but also the number of selected links for pricing is reduced as compared with the previous toll minimization methods. Moreover, as this model just uses the traffic assignment data for calculation, it could be considered as a quick and optimum solution for choosing the potential links.

Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Wireless Sensor Network industrial and civilian applications have been moved closer to us since they were originally developed for defense applications. They have been or will be widely used in industrial process monitoring and control, earth quake monitoring, healthcare applications, construction health monitoring, home automation, traffic control, and space exploration. The IEEE802.15.4 standard defines the PHY and MAC layers for low power wireless sensor networks. However, applications and research of wireless sensor networking are centered on battery powered devices. To remove the battery from the system is the ultimate goal of this research by using Energy Harvesting technology, which will largely reduce the wireless sensor network maintenance cost, increase the option open to application environments and push the speed of wireless sensor network industrialization. This thesis tackles the problem of RF link budget and PHY layer design for Energy Harvesting Wireless Sensor Network Nodes, through a modification to PHY/MAC layers. To this end, a prototype of energy harvesting radio is developed that hinges on burst-communication and solar cell energy harvesting techniques. The choice of operating frequency is considered relative to transmission range, antenna technology and RF link budget, and quantified by propagation measurements at four unlicensed frequencies in the VHF through UHF spectrums. A short preamble, PHY payload protocol frame structure and synchronization method are also proposed in order to support long sleep period duty cycle necessary in Energy Harvesting Radio systems. Some related work has recently begun under a standardization effort known as 802.15.4f. It is hoped that this thesis will contribute to this effort.