14 resultados para Academic path
em DigitalCommons@University of Nebraska - Lincoln
Resumo:
The title of this volume promises more than the content delivers. The heart of the book is information from Ward's 1992 University of Chicago doctoral dissertation, which focused on the social and cultural reasons leading to students dropping out of school. Her first two chapters provide a good review of research on dropouts and Indian education; the following six focus on the results of her 1987-1989 study of 698 Northern Cheyenne, Crow, and white high school students attending the Colstrip Public, St. Labre Catholic, and Busby Tribal Schools in Montana. Fifty-two percent of the students in this study were Indian, with a dropout rate of 45% .
Resumo:
This paper addresses the problem of survivable lightpath provisioning in wavelength-division-multiplexing (WDM) mesh networks, taking into consideration optical-layer protection and some realistic optical signal quality constraints. The investigated networks use sparsely placed optical–electrical–optical (O/E/O) modules for regeneration and wavelength conversion. Given a fixed network topology with a number of sparsely placed O/E/O modules and a set of connection requests, a pair of link-disjoint lightpaths is established for each connection. Due to physical impairments and wavelength continuity, both the working and protection lightpaths need to be regenerated at some intermediate nodes to overcome signal quality degradation and wavelength contention. In the present paper, resource-efficient provisioning solutions are achieved with the objective of maximizing resource sharing. The authors propose a resource-sharing scheme that supports three kinds of resource-sharing scenarios, including a conventional wavelength-link sharing scenario, which shares wavelength links between protection lightpaths, and two new scenarios, which share O/E/O modules between protection lightpaths and between working and protection lightpaths. An integer linear programming (ILP)-based solution approach is used to find optimal solutions. The authors also propose a local optimization heuristic approach and a tabu search heuristic approach to solve this problem for real-world, large mesh networks. Numerical results show that our solution approaches work well under a variety of network settings and achieves a high level of resource-sharing rates (over 60% for O/E/O modules and over 30% for wavelength links), which translate into great savings in network costs.
Resumo:
Survivable traffic grooming (STG) is a promising approach to provide reliable and resource-efficient multigranularity connection services in wavelength-division-multiplexing (WDM) optical networks. In this paper, we study the STG problem in WDM mesh optical networks employing path protection at the connection level. Both dedicated-protection and shared-protection schemes are considered. Given network resources, the objective of the STG problem is to maximize network throughput. To enable survivability under various kinds of single failures, such as fiber cut and duct cut, we consider the general shared-risklink- group (SRLG) diverse routing constraints. We first resort to the integer-linear-programming (ILP) approach to obtain optimal solutions. To address its high computational complexity, we then propose three efficient heuristics, namely separated survivable grooming algorithm (SSGA), integrated survivable grooming algorithm (ISGA), and tabu-search survivable grooming algorithm (TSGA). While SSGA and ISGA correspond to an overlay network model and a peer network model, respectively, TSGA further improves the grooming results from SSGA and ISGA by incorporating the effective tabu-search (TS) method. Numerical results show that the heuristics achieve comparable solutions to the ILP approach, which uses significantly longer running times than the heuristics.
Resumo:
This paper considers the problem of dedicated path-protection in wavelength-division multiplexed (WDM) mesh networks with waveband switching functionality under shared risk link group (SRLG) constraints. Two dedicated path protection schemes are proposed, namely the PBABL scheme and the MPABWL scheme. The PBABL scheme protects each working waveband-path through a backup waveband-path. The MPABWL scheme protects each working waveband-path by either a backup waveband-path or multiple backup lightpaths. Heuristic algorithms adopting random optimization technique are proposed for both the schemes. The performance of the two protection schemes is studied and compared. Simulation results show that both the heuristics can obtain optimum solutions and the MPABWL scheme leads to less switching and transmission costs than the PBABL scheme.
Resumo:
Wavelength-routed networks (WRN) are very promising candidates for next-generation Internet and telecommunication backbones. In such a network, optical-layer protection is of paramount importance due to the risk of losing large amounts of data under a failure. To protect the network against this risk, service providers usually provide a pair of risk-independent working and protection paths for each optical connection. However, the investment made for the optical-layer protection increases network cost. To reduce the capital expenditure, service providers need to efficiently utilize their network resources. Among all the existing approaches, shared-path protection has proven to be practical and cost-efficient [1]. In shared-path protection, several protection paths can share a wavelength on a fiber link if their working paths are risk-independent. In real-world networks, provisioning is usually implemented without the knowledge of future network resource utilization status. As the network changes with the addition and deletion of connections, the network utilization will become sub-optimal. Reconfiguration, which is referred to as the method of re-provisioning the existing connections, is an attractive solution to fill in the gap between the current network utilization and its optimal value [2]. In this paper, we propose a new shared-protection-path reconfiguration approach. Unlike some of previous reconfiguration approaches that alter the working paths, our approach only changes protection paths, and hence does not interfere with the ongoing services on the working paths, and is therefore risk-free. Previous studies have verified the benefits arising from the reconfiguration of existing connections [2] [3] [4]. Most of them are aimed at minimizing the total used wavelength-links or ports. However, this objective does not directly relate to cost saving because minimizing the total network resource consumption does not necessarily maximize the capability of accommodating future connections. As a result, service providers may still need to pay for early network upgrades. Alternatively, our proposed shared-protection-path reconfiguration approach is based on a load-balancing objective, which minimizes the network load distribution vector (LDV, see Section 2). This new objective is designed to postpone network upgrades, thus bringing extra cost savings to service providers. In other words, by using the new objective, service providers can establish as many connections as possible before network upgrades, resulting in increased revenue. We develop a heuristic load-balancing (LB) reconfiguration approach based on this new objective and compare its performance with an approach previously introduced in [2] and [4], whose objective is minimizing the total network resource consumption.
Resumo:
This is a survey of the procurement, organization and use of unpublished projects, theses, and Africana mateials in Hezekiah Oluwasanmi Library, Obafemi Awolowo University, Ile-Ife, Nigeria. The Africana section conserves knowledge, preserves cultural heritage, provides information, and supports education and research. This paper the location, mode of processing, circulation, and terms of availability of these materials. Recommendations are made on how to manage Africana materials in academic libraries where they constitute a vital component of collections.
Resumo:
Survivable traffic grooming (STG) is a promising approach to provide reliable and resource-efficient multigranularity connection services in wavelength division multiplexing (WDM) optical networks. In this paper, we study the STG problem in WDM mesh optical networks employing path protection at the connection level. Both dedicated protection and shared protection schemes are considered. Given the network resources, the objective of the STG problem is to maximize network throughput. To enable survivability under various kinds of single failures such as fiber cut and duct cut, we consider the general shared risk link group (SRLG) diverse routing constraints. We first resort to the integer linear programming (ILP) approach to obtain optimal solutions. To address its high computational complexity, we then propose three efficient heuristics, namely separated survivable grooming algorithm (SSGA), integrated survivable grooming algorithm (ISGA) and tabu search survivable grooming algorithm (TSGA). While SSGA and ISGA correspond to an overlay network model and a peer network model respectively, TSGA further improves the grooming results from SSGA and ISGA by incorporating the effective tabu search method. Numerical results show that the heuristics achieve comparable solutions to the ILP approach, which uses significantly longer running times than the heuristics.
Resumo:
We propose a resource-sharing scheme that supports three kinds of sharing scenarios in a WDM mesh network with path-based protection and sparse OEO regeneration. Several approaches are used to maximize the sharing of wavelength-links and OEO regenerators.
Resumo:
Board of Regents and President Smith: It's a real pleasure to be able to discuss the University's role in engagement with you today on behalf of the four campuses that comprise the University of Nebraska. In preparing this presentation I've drawn heavily upon the Kellogg Commission's report, entitled: "Returning to our Roots - The Engaged Institution," and the Michigan State University guidebook for planning-and-evaluating quality outreach, which is entitled: "Points of Distinction." I think both publications offer valuable insights as we explore the University's role as an engaged-partner with Nebraska.
Resumo:
It is both my honor and privilege to be here today to present the James A. Lake Academic Freedom Award. I thank you for this opportunity.
Resumo:
This study evaluates the content and quality of academic library websites. An evaluation checklist is used as a tool for evaluation of academic library websites. The checklist is divided into five main parts followed by Rating Table. The quantitative pointing system (ten point scale) and five point rating scales are used to evaluate and rank the websites. The study reveals that very few (16 percent) websites provide information about the date of last updating. Similarly very few (20 percent) websites provide links to other web reference sites and a moderate number (40 percent) have feedback forms for comments. On the other side, a good number of websites (76 percent) are efficient in loading images, icons, and graphics, and a large number (80 percent) have incorporated a web OPAC. The study is limited to the evaluation of websites of five academic libraries located in Bangalore, India.
Resumo:
Effective communication is the soul of any institution. New opportunities are presented by Information and Communication Technology (ICTS). Library managers must adopt a more critical and communication plan that will enhance their skills and allow for further training, as well as allowing stakeholders to have input into decision-making.
Resumo:
This presentation will discuss the personal opportunities available to people of color to build university-wide interdisciplinary centers and the obstacles inherent in doing so. I Professor Smith will discuss the opportunities and obstacles involved in working with faculty members, department chairs, and deans to accomplish an interdisciplinary mission.
Resumo:
"What my research revealed was that African American students who do not identify with the academic community do not see it as real; rather, they view their academic education as only a means to an end."