The aim of this thesis was to bridge a gap in the research literature with regard to commentary on and evaluation of the relationship between British land-use planning and the management and development of the railway network in the years between 1948-94 when British railways were in public ownership. Although the research was focused on the nationalised main line system, it reviewed other rail systems where this was helpful to the analysis. The research utilised a review of the relationship between the railway network and urban form in the years to 1947 to derive analytical criteria and to serve as a point of departure for the core of the thesis. The overall relationship between the two sectors post-1948 was explored, at a broad geographical scale, with regard to institutional relationships, policy, and outcomes with regard to the spatial relationships between the railway network and patterns of urban form. The results of this research were used to derive hypotheses about the relationships which were then tested in a case study of the Manchester conurbation. The main conclusions are that there were few periods between 1948-94 when the ideological, institutional and policy frameworks necessary for a close and positive relationship between the planning and railway sectors were in place simultaneously. The contexts which were most favourable were with regard to: the location of new towns and town expansion projects in the South East in 1950s and 1960s; the improvement of railway networks in the PTE areas between 1968-79 along with the development of strategic policies for the restriction of major trip generators to CBDs; the period between 1985-94 when a surge in the property market was accompanied by BR Sectorisation, investment in other forms of fixed track transit, and the promotion of major development projects at and around stations, especially in CBDs. The research concludes by identifying opportunities for further historical research and briefly reviewing the relevance of the findings to contemporary research.

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During the second half of the 20th century, there was an epic deterioration of the urban fabric of the typical American neighborhood. Starting with the fleeing of city dwellers into the outskirts of suburbia in the 1950s and the exodus of commercial institutions in the 1970s, neighborhood sprawl hit its stride with the elimination of the neighborhood school in the 1980s. With this community-defining component being replaced by giant, remote educational facilities, the American neighborhood was finally a shell of its former self. If the neighborhood represents the cell, then the home represents the nucleus. In 2003, 1.1 million children were being homeschooled in America, with signs of homeschooling becoming a growing trend. One of the main reasons parents chose to homeschool their children was concern about the environment of other schools. With a large number of students being sent to mega-schools and a growing number of students being homeschooled, there is an increasing gap between the scales of schools being used for education, and neither seems to be a complete solution. In addition, a significant part of relevant literacy in today?s global community deals with digital literacy. The digital divide is the gap between those people with effective access to digital and information technology, and those without. Many institutions including the United Nations believe the digital divide is the key to local and global, social and economic inequalities. Information, or knowledge, is being stored and made accessible through digital means. However, if a person does not know how to access this information, they are less equipped than the person who does, and the problem of a gap in knowledge becomes exponentially larger. In what ways can low population learning environments be networked into the urban fabric of a blighted neighborhood for the purpose of improving academic performance? In addition, what are the social, civic and economic opportunities and disadvantages afforded to a neighborhood when a digital learning network is overlaid with a physical network of learning environments? This thesis intends to reestablish the neighborhood school, by injecting contemporary, low-population learning environments branded as HOM-S to act as a brand of modular architecture which will bridge the gap between the home and the school. The solution is proposed as potentially ubiquitous, but for the sake of this thesis I will be using the neighborhoods surrounding Holmes Elementary School and Liberty City Elementary School in Miami, Fl, as its site. This neighborhood has a high crime rate, low testing scores, high dropout rate, lack of positive identity, and low economic class, and therefore represents the extreme conditions this thesis is poised to remediate. The program will be defined as a pre-university learning environment that is meant to complement and correct at-risk education systems and the neighborhoods they serve. The HOM-S will be a bridge between the home and the mega-school, creating both an ?education path? and a campus network for pre-university students. Through the use of flexible technology, distance learning networks, and site sensitive architecture, as well as a re-interpretation of curriculum and teacher-student roles, these environments will be designed to turn deteriorated neighborhoods into healthy communities.

Thesis (M.S.)--Boston University / The purpose of this study is (l) to present in chronological sequence the various types of network television news programs that appeared between the years 1948-1957; (2) to evaluate the quality or news presentation on these programs by examination of their format and change in format; and (3) to determine in which area, if any, television news, as reflected in the network programs examined, is superior to the other existing news disseminating media.

Knowledge of a network’s entities and the physical connections between them, a network’s physical topology, can be useful in a variety of network scenarios and applications. Administrators can use topology information for fault- finding, inventorying and network planning. Topology information can also be used during protocol and routing algorithm development, for performance prediction and as a basis for accurate network simulations. Specifically, from a network security perspective, threat detection, network monitoring, network access control and forensic investigations can benefit from accurate network topology information. The dynamic nature of large networks has led to the development of various automatic topology discovery techniques, but these techniques have mainly focused on cooperative network environments where network elements can be queried for topology related information. The primary objective of this study is to develop techniques for discovering the physical topology of an Ethernet network without the assistance of the network’s elements. This dissertation describes the experiments performed and the techniques developed in order to identify network nodes and the connections between these nodes. The product of the investigation was the formulation of an algorithm and heuristic that, in combination with measurement techniques, can be used for inferring the physical topology of a target network. / Dissertation (MSc)--University of Pretoria, 2008. / Computer Science / unrestricted

Modern computer networks pose a great challenge for monitoring the network performance due to their large scale and high complexity. Directly measuring the performance of internal network elements is prohibitive due to the tremendous overhead. Alternatively, network tomography, a technique that infers the unobserved network characteristics (e.g., link delays) from a small number of measurements (e.g., end-to-end path delays), is a promising solution for monitoring the internal network state in an e cient and e ective manner. This thesis initiates two variants of network tomography: concentrated network tomography and bound-based network tomography. The former is motivated by the practical needs that network operators normally concentrate on the performance of critical paths; the latter is due to the need of estimating performance bounds whenever exact performance values cannot be determined. This thesis tackles core technical di culties in concentrated network tomography and bound- based network tomography, including (1) the path identi ability problem and the monitor deploy- ment strategy for identifying a set of target paths, (2) strategies for controlling the total error bound as well as the maximum error bound over all network links, and (3) methods of constructing measure- ment paths to obtain the tightest total error bound. We evaluate all the solutions with real-world Internet service provider (ISP) networks. The theoretical results and the algorithms developed in this thesis are directly applicable to network performance management in various types of networks, where directly measuring all links is practically impossible. / Graduate

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / This paper presents a method for managing a Mixed Network with multiple ground stations and Test Articles (TA) preferences. The main difference between a Ground Station (cellular) network and the over the horizon (ad-hoc) network is that the ad-hoc method has no fixed infrastructure. This paper presents the computation and performance of a clustering technique for mobile nodes within the simulated mixed network environment with multiple ground stations and users preferences for those ground stations. This includes organization for multiple ground stations and for TA's gravitating toward a ground station of their choice on the basis of service and performance.

The Internet faces well-known challenges in realizing modifications to the core architecture. To help overcome these limitations, the use of network virtualization has been proposed. Network virtualization enables the deployment of novel network architectures and services on existing Internet infrastructure. Virtual networks run over physical networks and use Internet paths and protocols as essentially a link layer in the virtual network. Virtual networks can also share the resources in the physical substrate. Effective use of the underlying substrate network requires intelligent placement of virtual networks so that underlying resources do not incur over-subscription. Because virtual networks can come and go over time, and underlying networks can experience their own dynamic changes, virtual networks need to be migrated---re-mapped to the physical network during active operation---to maintain good performance. While virtual network placement, and to a lesser extent migration, has been studied in the past, little attention has been devoted to designing, deploying, and evaluating migration mechanisms for virtual networks. In this dissertation, we design virtual network migration mechanisms for different substrate platforms and further design a system to mitigate the effects of virtual network migration. In particular this dissertation makes the following contributions: 1. With the goal of minimizing the disruption during a virtual network migration, we design three algorithms for scheduling the sequence of virtual router moves that takes a virtual network from its original placement to its new placement. 2. We design and implement a controller-based architecture for virtual network migration on PlanetLab. This work explores the challenges in implementing virtual network migration on real infrastructure. Recommendations are given for infrastructure that support virtual network migration. 3. We propose and implement a mechanism to mitigate the performance degradation resulting from virtual network migration through transport and application layer collaboration. We utilize a centralized controller to notify the end-systems or the gateways about the time of the virtual network migration such that we prevent packet loss to the application traffic of the end-systems.