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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Integrating XML and RDF concepts to achieve automation within a tactical knowledge management environment

McCarty, George E., Jr. 03 1900 (has links)
Approved for public release, distribution is unlimited / Since the advent of Naval Warfare, Tactical Knowledge Management (KM) has been critical to the success of the On Scene Commander. Today's Tactical Knowledge Manager typically operates in a high stressed environment with a multitude of knowledge sources including detailed sensor deployment plans, rules of engagement contingencies, and weapon delivery assignments. However the WarFighter has placed a heavy reliance on delivering this data with traditional messaging processes while focusing on information organization vice knowledge management. This information oriented paradigm results in a continuation of data overload due to the manual intervention of human resources. Focusing on the data archiving aspect of information management overlooks the advantages of computational processing while delaying the empowerment of the processor as an automated decision making tool. Resource Description Framework (RDF) and XML provide the potential of increased machine reasoning within a KM design allowing the WarFighter to migrate from the dependency on manual information systems to a more computational intensive Knowledge Management environment. However the unique environment of a tactical platform requires innovative solutions to automate the existing naval message architecture while improving the knowledge management process. This thesis captures the key aspects for building a prototype Knowledge Management Model and provides an implementation example for evaluation. The model developed for this analysis was instantiated to evaluate the use of RDF and XML technologies in the Knowledge Management domain. The goal for the prototype included: 1. Processing required technical links in RDF/XML for feeding the KM model from multiple information sources. 2. Experiment with the visualization of Knowledge Management processing vice traditional Information Resource Display techniques. The results from working with the prototype KM Model demonstrated the flexibility of processing all information data under an XML context. Furthermore the RDF attribute format provided a convenient structure for automated decision making based on multiple information sources. Additional research utilizing RDF/XML technologies will eventually enable the WarFighter to effectively make decisions under a Knowledge Management Environment. / Civilian, SPAWAR System Center San Diego
82

The Changing Role of Soft Money on Campaign Finance Reform.The Birth of the 527 and its Consequences.

El`Ghaouti, Valerie Rose 08 June 2007 (has links)
In a time when record numbers of dollars are being spent on campaigns the unregulated dollars are flowing faster than ever. Hundreds of millions of dollars in independent expenditures are being used for “issue advocacy”, print and broadcast advertising, which does not expressly endorse or oppose a candidate for office. The one-time campaign finance ceiling has become the campaign finance basement. Individuals are able to give unlimited dollars to 527 organizations, which function outside of all campaign finance regulation and provide a new path for the flow of political dollars. Since the passage of the Bipartisan Campaign Reform Act, commonly known as the McCain-Feingold Act, federally regulated lobbyists and PACS are being edged out of the political dollar due to contribution limits. It is in 1996 that we witness the birth of 527 organizations and the flourishing growth of soft money spending in the campaign process.
83

Robust video streaming over time-varying wireless networks

Demircin, Mehmet Umut 03 July 2008 (has links)
Multimedia services and applications became the driving force in the development and widespread deployment of wireless broadband access technologies and high speed local area networks. Mobile phone service providers are offering wide range of multimedia applications over high speed wireless data networks. People can watch live TV, stream on-demand video clips and place videotelephony calls using multimedia capable mobile devices. Mobile devices will soon support capturing and displaying high definition video. Similar evolution is also occurring in the local area domain. The video receiver or storage devices were conventionally connected to display devices using cables. By using wireless local area networking (WLAN) technologies, convenient and cable-free connectivity can be achieved. Media over wireless home networks prevents the cable mess and provides mobility to portable TVs. However, there still exit challenges for improving the quality-of-service (QoS) of multimedia applications. Conventional service architectures, network structures and protocols lack to provide a robust distribution medium since most of them are not designed considering the high data rate and real-time transmission requirements of digital video. In this thesis the challenges of wireless video streaming are addressed in two main categories. Streaming protocol level issues constitute the first category. We will refer to the collection of network protocols that enable transmitting digital compressed video from a source to a receiver as the streaming protocol. The objective of streaming protocol solutions is the high quality video transfer between two networked devices. Novel application-layer video bit-rate adaptation methods are designed for handling short- and long-term bandwidth variations of the wireless local area network (WLAN) links. Both transrating and scalable video coding techniques are used to generate video bit-rate flexibility. Another contribution of this thesis study is an error control method that dynamically adjusts the forward error correction (FEC) rate based on channel bit-error rate (BER) estimation and video coding structure. The second category is the streaming service level issues, which generally surface in large scale systems. Service system solutions target to achieve system scalability and provide low cost / high quality service to consumers. Peer-to-peer assisted video streaming technologies are developed to reduce the load of video servers. Novel video file segment caching strategies are proposed for more efficient peer-to-peer collaboration.
84

Traffic Engineering with MPLS and QOS

Ikram, Imran January 2009 (has links)
In the modern era there exist applications that require very high resources and generate a tremendous amount of traffic so they require considerable amount of bandwidth and QOS to operate and perform correctly. MPLS is a new and a fast technology that offers much remuneration both in terms of providing trouble-free and efficient security together with the high speed of switching. MPLS not only guarantees quality of service of IP networks but in addition to provides scope for traffic engineering it offers many enhanced features of IP networks as it does not replace IP routing, but works along with existing and future routing technologies to provide high-speed data forwarding between label-switched routers (LSRs) together with QOS. Many network carriers are facing the problem of how to accommodate such ever-growing demands for bandwidth. And the static nature of current routing algorithms, such as OSPF or IS-IS, the situation is going even worse since the traffic is concentrated on the "least cost" paths which causes the congestion for some links while leaving other links lightly loaded. Therefore, MPLS traffic engineering is proposed and by taking advantage of MPLS, traffic engineering can route the packets through explicit paths to optimize network resource utilization and traffic performance. MPLS provides a robust quality of service control feature in the internet. MPLS class of service feature can work in accordance with other quality of service architectures for IP networks.
85

Zabezpečení přenosu dat BCH kódy / Error protection of data transmission using BCH Codes

Kašpar, Jaroslav January 2008 (has links)
The thesis Data transmission error-protection with BCH codes deals with a large class of random-error correcting cyclic codes which are able to protect binary data and can be used for example in data storages, high speed modems. Bose, Chaudhuri and Hocquenghem (BCH) codes operate over algebraic structures called Galois fields. The BCH encoding is the same as cyclic encoding and can be done with linear feedback shift register but decoding is more complex and can be done with different algorithms - in this thesis there are two algorithms for decoding Peterson and Berlekam-Massey mentioned. The aim of this thesis is to find BCH code which is able to correct t = 6 independent errors in up to data sequence n = 150 bits, then peruse possible realizations of the codecs and set criteria for the best realization, then design and test this realization. This thesis is split into three main parts. In the first part there are encoding and decoding methods of the BCH code generally described. The second part deals with selecting of the right code and realization. There was chosen BCH (63,30) code and realization with FPGA chip. In the last part is described design of BCH encoder and decoder and compilation in the Altera design software.
86

Evaluation of a content download service based on FLUTE and LDPC for improving the Quality of Experience over multicast wireless networks

De Fez Lava, Ismael 17 April 2014 (has links)
Esta tesis estudia la distribución de ficheros en redes inalámbricas, analizando diferentes mecanismos que permiten optimizar la transmisión en términos de ancho de banda y calidad de experiencia. Concretamente, la tesis se centra en la transmisión de ficheros en canales multicast. Dicha transmisión resulta adecuada en ciertos entornos y tiene múltiples aplicaciones, algunas de las cuales se presentan en este trabajo. La tesis analiza en profundidad FLUTE (File Delivery over Unidirectional Transport), un protocolo para el envío fiable de ficheros en canales unidireccionales, y presenta algunas propuestas para mejorar la transmisión a través de dicho protocolo. En este sentido, una de las bases de este protocolo es el uso de un mecanismo llamado Tabla de Envío de Ficheros (FDT), que se utiliza para describir los contenidos transmitidos. Este trabajo analiza cómo la transmisión de la FDT afecta al funcionamiento del protocolo FLUTE, y proporciona una metodología para optimizar el envío de contenido mediante FLUTE. Por otro lado, en la transmisión de ficheros por multicast resulta esencial ofrecer un servicio fiable. Entre los distintos mecanismos utilizados por FLUTE para ofrecer fiabilidad, este trabajo analiza principalmente los códigos de corrección AL-FEC (Application Layer ¿ Forward Error Correction), los cuales añaden redundancia a la transmisión para minimizar los efectos de las pérdidas en el canal. Al respecto, esta tesis evalúa los códigos LDPC Staircase y LDPC Triangle, comparando su funcionamiento bajo diferentes condiciones de transmisión. Además, en el caso de tener un canal de retorno, una de las principales contribuciones de esta tesis es la propuesta de códigos LDPC adaptativos para servicios de descarga de ficheros. En esta clase de códigos, el servidor de contenidos cambia dinámicamente la cantidad de protección FEC proporcionada en función de las pérdidas que detectan los usuarios. La evaluación demuestra el buen funcionamiento de estos códigos en distintos entornos. / De Fez Lava, I. (2014). Evaluation of a content download service based on FLUTE and LDPC for improving the Quality of Experience over multicast wireless networks [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37051 / TESIS / Premios Extraordinarios de tesis doctorales
87

Systémy realizace protichybového kódování / Systems Design of Correction Coding

Křivánek, Vítězslav January 2009 (has links)
Due to growing transmission speed burst-forming errors tend to occur still more frequently not exclusively in data transmission. The presented paper concentrates on the search for alternative burst error correction solutions complementing the existing methods in use. Its objective is an elaboration of a detailed analysis of the issue of convolution codes for error burst correction which can be used in individual anti-error systems and thus an achievement of better results than those attained by mass application of the existing solutions. First the methods implemented to remove or suppress burst errors are briefly characterized. This part is followed by a detailed description of the individual systematic convolution codes by means of mathematical tools which extend the set of possible evaluative criteria of anti-error systems which can be applied while assessing proposals for individual solutions. The acquired code properties are compared with convolution codes as well as with other versions of proposals for message protection against an error burst. The processed convolution codes are subject to testing by means of Matlab mathematical programme simulation in order to validate the correctness of the derived mathematical tools. This is because simulation represents the principal method applied to verify and present an already proposed security process and enables the acquisition of a better overview of the issue at hand. The feasibility of the individual anti-error systems is then confirmed by way of creating a circuit behaviour description in the VHDL language. Its high portability presents a big advantage when drafting individual systems of the actual implementation.
88

Enhanced Distance Measuring Equipment Data Broadcast Design, Analysis, Implementation, and Flight-Test Validation

Naab-Levy, Adam O. January 2015 (has links)
No description available.
89

Utilization of forward error correction (FEC) techniques with extensible markup language (XML) schema-based binary compression (XSBC) technology

Norbraten, Terry D. 12 1900 (has links)
Approved for public release, distribution is unlimited / In order to plug-in current open sourced, open standard Java programming technology into the building blocks of the US Navy's ForceNet, first, stove-piped systems need to be made extensible to other pertinent applications and then a new paradigm of adopting extensible and cross-platform open technologies will begin to bridge gaps with old and new weapons systems. The battle-space picture in real time and with as much detail, or as little detail needed is now a current vital requirement. Access to this information via wireless laptop technology is here now. Transmission of data to increase the resolution of that battle-space snapshot will invariably be through noisy links. Noisy links such as found in the shallow water littoral regions of interest will be where Autonomous Underwater and Unmanned Underwater Vehicles (AUVs/UUVs) are gathering intelligence for the sea warrior in need of that intelligence. The battle-space picture built from data transmitted within these noisy and unpredictable acoustic regions demands efficiency and reliability features abstract to the user. To realize this efficiency Extensible Markup Language (XML) Schema-based Binary Compression (XSBC), in combination with Vandermode-based Forward Error Correction (FEC) erasure codes, offer the qualities of efficient streaming of plain text XML documents in a highly compressed form, and a data self-healing capability should there be loss of data during transmission in unpredictable transmission mediums. Both the XSBC and FEC libraries detailed in this thesis are open sourced Java Application Program Interfaces (APIs) that can be readily adapted for extensible, cross-platform applications that will be enhanced by these desired features to add functional capability to ForceNet for the sea warrior to access on demand, at sea and in real-time. These features will be presented in the Autonomous Underwater Vehicle (AUV) Workbench (AUVW) Java-based application that will become a valuable tool for warriors involved with Undersea Warfare (UW). / Lieutenant, United States Navy
90

Adaptive Resource Allocation for Statistical QoS Provisioning in Mobile Wireless Communications and Networks

Du, Qinghe 2010 December 1900 (has links)
Due to the highly-varying wireless channels over time, frequency, and space domains, statistical QoS provisioning, instead of deterministic QoS guarantees, has become a recognized feature in the next-generation wireless networks. In this dissertation, we study the adaptive wireless resource allocation problems for statistical QoS provisioning, such as guaranteeing the specified delay-bound violation probability, upper-bounding the average loss-rate, optimizing the average goodput/throughput, etc., in several typical types of mobile wireless networks. In the first part of this dissertation, we study the statistical QoS provisioning for mobile multicast through the adaptive resource allocations, where different multicast receivers attempt to receive the common messages from a single base-station sender over broadcast fading channels. Because of the heterogeneous fading across different multicast receivers, both instantaneously and statistically, how to design the efficient adaptive rate control and resource allocation for wireless multicast is a widely cited open problem. We first study the time-sharing based goodput-optimization problem for non-realtime multicast services. Then, to more comprehensively characterize the QoS provisioning problems for mobile multicast with diverse QoS requirements, we further integrate the statistical delay-QoS control techniques — effective capacity theory, statistical loss-rate control, and information theory to propose a QoS-driven optimization framework. Applying this framework and solving for the corresponding optimization problem, we identify the optimal tradeoff among statistical delay-QoS requirements, sustainable traffic load, and the average loss rate through the adaptive resource allocations and queue management. Furthermore, we study the adaptive resource allocation problems for multi-layer video multicast to satisfy diverse statistical delay and loss QoS requirements over different video layers. In addition, we derive the efficient adaptive erasure-correction coding scheme for the packet-level multicast, where the erasure-correction code is dynamically constructed based on multicast receivers’ packet-loss statuses, to achieve high error-control efficiency in mobile multicast networks. In the second part of this dissertation, we design the adaptive resource allocation schemes for QoS provisioning in unicast based wireless networks, with emphasis on statistical delay-QoS guarantees. First, we develop the QoS-driven time-slot and power allocation schemes for multi-user downlink transmissions (with independent messages) in cellular networks to maximize the delay-QoS-constrained sum system throughput. Second, we propose the delay-QoS-aware base-station selection schemes in distributed multiple-input-multiple-output systems. Third, we study the queueaware spectrum sensing in cognitive radio networks for statistical delay-QoS provisioning. Analyses and simulations are presented to show the advantages of our proposed schemes and the impact of delay-QoS requirements on adaptive resource allocations in various environments.

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