7,661 research outputs found

    An operating system for future aerospace vehicle computer systems

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    The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure

    Efficient Mission Planning for Robot Networks in Communication Constrained Environments

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    Many robotic systems are remotely operated nowadays that require uninterrupted connection and safe mission planning. Such systems are commonly found in military drones, search and rescue operations, mining robotics, agriculture, and environmental monitoring. Different robotic systems may employ disparate communication modalities such as radio network, visible light communication, satellite, infrared, Wi-Fi. However, in an autonomous mission where the robots are expected to be interconnected, communication constrained environment frequently arises due to the out of range problem or unavailability of the signal. Furthermore, several automated projects (building construction, assembly line) do not guarantee uninterrupted communication, and a safe project plan is required that optimizes collision risks, cost, and duration. In this thesis, we propose four pronged approaches to alleviate some of these issues: 1) Communication aware world mapping; 2) Communication preserving using the Line-of-Sight (LoS); 3) Communication aware safe planning; and 4) Multi-Objective motion planning for navigation. First, we focus on developing a communication aware world map that integrates traditional world models with the planning of multi-robot placement. Our proposed communication map selects the optimal placement of a chain of intermediate relay vehicles in order to maximize communication quality to a remote unit. We also vi propose an algorithm to build a min-Arborescence tree when there are multiple remote units to be served. Second, in communication denied environments, we use Line-of-Sight (LoS) to establish communication between mobile robots, control their movements and relay information to other autonomous units. We formulate and study the complexity of a multi-robot relay network positioning problem and propose approximation algorithms that restore visibility based connectivity through the relocation of one or more robots. Third, we develop a framework to quantify the safety score of a fully automated robotic mission where the coexistence of human and robot may pose a collision risk. A number of alternate mission plans are analyzed using motion planning algorithms to select the safest one. Finally, an efficient multi-objective optimization based path planning for the robots is developed to deal with several Pareto optimal cost attributes

    New Belgrade after 1999: Spatial Violence as De-socialisation, De-Romanisation and De-historisation

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    This abstract is a pre copy-edited version of my paper. It was advised during a PGCAP session that staff need to submit a pre copy-edited version onto PEARL. Once the article is published online, it will be available at the following permanent link: http://dx.doi.org/10.1080/13264826.2014.1036491 .New Belgrade after 1999 is associated with the transition from a socialist and single-party state to a consumer capitalist and multi-party system, with the latter perceived as an indicator of democracy. This paper asks if and how this transitional period points to NATO’s 1999 bombing campaign still being in-operation through spatial violence by other means, with these means related to the negation of difference and the transformation of everyday life and social values. Might this spatial violence be even more coercive than that of the war as it manifests through the convergence of military, legal, governmental and economic entities of international “redevelopment” agencies working in the name of “security” along with the Serbian government? This paper explores this proposition by focusing on the post-1999 transformation and re-modernisation of New Belgrade as an elimination of difference through processes of de-socialisation, de-Romanisation and dehistorisation connected with neo-liberal privatisation

    Allocation des ressources dans les environnements informatiques en périphérie des réseaux mobiles

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    Abstract: The evolution of information technology is increasing the diversity of connected devices and leading to the expansion of new application areas. These applications require ultra-low latency, which cannot be achieved by legacy cloud infrastructures given their distance from users. By placing resources closer to users, the recently developed edge computing paradigm aims to meet the needs of these applications. Edge computing is inspired by cloud computing and extends it to the edge of the network, in proximity to where the data is generated. This paradigm leverages the proximity between the processing infrastructure and the users to ensure ultra-low latency and high data throughput. The aim of this thesis is to improve resource allocation at the network edge to provide an improved quality of service and experience for low-latency applications. For better resource allocation, it is necessary to have reliable knowledge about the resources available at any moment. The first contribution of this thesis is to propose a resource representation to allow the supervisory xentity to acquire information about the resources available to each device. This information is then used by the resource allocation scheme to allocate resources appropriately for the different services. The resource allocation scheme is based on Lyapunov optimization, and it is executed only when resource allocation is required, which reduces the latency and resource consumption on each edge device. The second contribution of this thesis focuses on resource allocation for edge services. The services are created by chaining a set of virtual network functions. Resource allocation for services consists of finding an adequate placement for, routing, and scheduling these virtual network functions. We propose a solution based on game theory and machine learning to find a suitable location and routing for as well as an appropriate scheduling of these functions at the network edge. Finding the location and routing of network functions is formulated as a mean field game solved by iterative Ishikawa-Mann learning. In addition, the scheduling of the network functions on the different edge nodes is formulated as a matching set, which is solved using an improved version of the deferred acceleration algorithm we propose. The third contribution of this thesis is the resource allocation for vehicular services at the edge of the network. In this contribution, the services are migrated and moved to the different infrastructures at the edge to ensure service continuity. Vehicular services are particularly delay sensitive and related mainly to road safety and security. Therefore, the migration of vehicular services is a complex operation. We propose an approach based on deep reinforcement learning to proactively migrate the different services while ensuring their continuity under high mobility constraints.L'évolution des technologies de l'information entraîne la prolifération des dispositifs connectés qui mène à l'exploration de nouveaux champs d'application. Ces applications demandent une latence ultra-faible, qui ne peut être atteinte par les infrastructures en nuage traditionnelles étant donné la distance qui les sépare des utilisateurs. En rapprochant les ressources aux utilisateurs, le paradigme de l'informatique en périphérie, récemment apparu, vise à répondre aux besoins de ces applications. L’informatique en périphérie s'inspire de l’informatique en nuage, en l'étendant à la périphérie du réseau, à proximité de l'endroit où les données sont générées. Ce paradigme tire parti de la proximité entre l'infrastructure de traitement et les utilisateurs pour garantir une latence ultra-faible et un débit élevé des données. L'objectif de cette thèse est l'amélioration de l'allocation des ressources à la périphérie du réseau pour offrir une meilleure qualité de service et expérience pour les applications à faible latence. Pour une meilleure allocation des ressources, il est nécessaire d'avoir une bonne connaissance sur les ressources disponibles à tout moment. La première contribution de cette thèse consiste en la proposition d'une représentation des ressources pour permettre à l'entité de supervision d'acquérir des informations sur les ressources disponibles à chaque dispositif. Ces informations sont ensuite exploitées par le schéma d'allocation des ressources afin d'allouer les ressources de manière appropriée pour les différents services. Le schéma d'allocation des ressources est basé sur l'optimisation de Lyapunov, et il n'est exécuté que lorsque l'allocation des ressources est requise, ce qui réduit la latence et la consommation en ressources sur chaque équipement de périphérie. La deuxième contribution de cette thèse porte sur l'allocation des ressources pour les services en périphérie. Les services sont composés par le chaînage d'un ensemble de fonctions réseau virtuelles. L'allocation des ressources pour les services consiste en la recherche d'un placement, d'un routage et d'un ordonnancement adéquat de ces fonctions réseau virtuelles. Nous proposons une solution basée sur la théorie des jeux et sur l'apprentissage automatique pour trouver un emplacement et routage convenable ainsi qu'un ordonnancement approprié de ces fonctions en périphérie du réseau. La troisième contribution de cette thèse consiste en l'allocation des ressources pour les services véhiculaires en périphérie du réseau. Dans cette contribution, les services sont migrés et déplacés sur les différentes infrastructures en périphérie pour assurer la continuité des services. Les services véhiculaires sont en particulier sensibles à la latence et liés principalement à la sûreté et à la sécurité routière. En conséquence, la migration des services véhiculaires constitue une opération complexe. Nous proposons une approche basée sur l'apprentissage par renforcement profond pour migrer de manière proactive les différents services tout en assurant leur continuité sous les contraintes de mobilité élevée

    Routing algorithm for the ground team in transmission line inspection using unmanned aerial vehicle

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    With the rapid development of robotics technology, robots are increasingly used to conduct various tasks by utility companies. An unmanned aerial vehicle (UAV) is an efficient robot that can be used to inspect high-voltage transmission lines. UAVs need to stay within a data transmission range from the ground station and periodically land to replace the battery in order to ensure that the power system can support its operation. A routing algorithm must be used in order to guide the motion and deployment of the ground station while using UAV in transmission line inspection. Most existing routing algorithms are dedicated to pathfinding for a single object that needs to travel from a given start point to end point and cannot be directly used for guiding the ground station deployment and motion since multiple objects (i.e., the UAV and the ground team) whose motions and locations need to be coordinated are involved. In this thesis, we intend to explore the routing algorithm that can be used by utility companies to effectively utilize UAVs in transmission line inspection. Both heuristic and analytical algorithms are proposed to guide the deployment of the ground station and the landing point for UAV power system change. A case study was conducted to validate the effectiveness of the proposed routing algorithm and examine the performance and cost-effectiveness --Abstract, page iii

    Analysis of the Theory and Traffic Scheduling for Transit Network by Genetic Algorithm-Based Optimization Technique

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    This work utilizes the transit network, which aims to combine the genetic algorithm for analyzing the theory and traffic scheduling based on the traditional methodology. The dynamic methodology is used to schedule the model of transit system, which aims to optimize the demand in the transit network. This model illustrates the methodology of the genetic based transit network (GATN) algorithm to enhance the primary challenges in the transit network. The proposed methodology provides to be significant, with minimizing the objective model of around 27.2%. The model significantly managed to lower the total routes available in the transit network and all travelers related to the time and the transit trip from the initial stage. The significant system obtained using the optimization methodology has 180 routes, 110 less than the initial network, which has a variation by different transit network. This final transmission has been minimized to 33.6% by the proposed methodology in the transit network length and 4.1% reduction in the transfer average. The transition obtained from the multi-level objective function to unique optimization that considers the weighted function proved to be effective

    Feature relative navigation for automous underwater vehicles

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997.Includes bibliographical references (leaves 184-196).by Andrew Arnold Bennett.Ph.D

    Urban Regeneration of Industrial Areas: Affordable Housing for Low Income Populations in Cities

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    The UK-China Sustainable Development Dialogue (SDD) is a partnership between the UK and Chinese Governments to promote collaboration and good practice on sustainable development. It is framed by a 2004 joint Prime Ministerial declaration and was formally established in 2005 by an agreement signed by UK Deputy Prime Minister John Prescott and State Councillor Tang. The SDD was founded on the recognition that, in an interdependent world, international co-operation is needed to ensure that learning is shared and efforts are made collectively towards achieving common goals. This report is the 13th and Final Paper in the SDD (Urban Strand. It draws together the core conclusions from the previous twelve papers and offers recommendations for taking the dialogue forward

    Beyond the blueprint : a critical view on plans for transit-oriented development (TOD) in the new indonesian capital

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    Indonesia is relocating its capital city from Jakarta to a new city built from scratch called IKN (Ibu Kota Negara/Nusantara). Starting with the prioritized Government Precinct, the full relocation will be completed by 2045. The master plan emphasizes Transit-oriented Development (TOD) principles to encourage walking and transit, including incorporating the 10-minute concept. Meanwhile, South Korea has been moving the administrative capital city to Sejong City since 2007 and will be finished by 2030. Both cities share similar goals and approaches to implementing TOD; however, TOD can have pros and cons. While TOD can reduce traffic congestion, improve health, spur economic benefits and foster a sense of community, it can lead to gentrification, limited parking space that discourages early dwellers and vacant districts that induces negative impacts. Moreover, walking in Indonesia is unpopular due to the lack of safe, comfortable, and reliable transit modes, motorcycle and ride-hailing service dependence, and thermal comfort issues. Therefore, this thesis aims to identify the TOD aspects in IKN walkability and transit planning that may face issues after the city is developed based on the study case of pre- and post-construction Sejong so that IKN can anticipate and prepare. The Government Precinct encourages walking and transit by providing various types of pedestrian environments, permeable edges, and multiple transit systems, including BRT. The planned walking environments and transit nodes accommodate the 15-minute radius. Still, the planners must also consider the local context for the walkable distance, provide amenities that enhance thermal comfort, support modal shift facilities, and be vibrant with activities all time of the day and week so it is not vacant after working hours. Learning from Sejong, forcing people to walk in the interconnected walkways and limiting the parking lot to encourage people to use BRT is inefficient and inconvenient. Adopting a design adaptable to unforeseen challenges is crucial to promote social interaction, active mobility by walking and transit, and reducing automobile dependency. IKN must also implement non-physical interventions by enforcing strict policies, maximizing public transport frequency, and conducting regular assessments. A successful IKN plan can be a template for other TOD megaprojects globally
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