Virtualization is the key technology which has provided smarter and easier ways for effectively utilizing resources provided by the hypervisor. Virtualization allows multiple operative systems (OS) to run on a single hardware. The resources from a hardware are allocated to virtual machines (VM) by hypervisor. It is important to know how the performance of virtual switches used in hypervisor for network communication affect the network traffic.   Performance of Linux Bridge (LB) and Open vSwitch (OVS) is investigated in this study. The method that has been used in this research is experimentation. Two different scenarios are used to benchmark the performance of LB and OVS in virtual and non-virtual environment. Performance metrics bitrate is used to benchmark the performance LB and OVS. The results received from the experimental runs contains the ingress bitrate and egress bitrate of LB and OVS in virtual and non-virtual environment. The results also contain the ingress and egress bitrate values from scenarios with different memory and CPU cores in virtual environment. Results achieved in this thesis report are from multiple experiment configurations. From results it can concluded that LB and OVS have almost same performance in non-virtual environment. There are small differences in ingress and egress of both virtual switches.

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In this article open access is defined, and the resources and issues of greatest relevance to the medical librarian are discussed. The economics of open access publishing is examined from the point of view of the university library. Open access resources, both journals and articles in repositories, are already significant and growing rapidly. There are close to 2300 fully open-access peer review journals listed in the Directory of Open Access Journals (DOAJ) (320 health sciences titles are included). DOAJ is adding titles at a rate of 1.5 per day. An OAIster search of resources in repositories includes more than 7.6 million items (a rough estimate of the number of articles in repositories, although not all items are full text), and this number will exceed one billion items before the end of 2007. Medical research funders, including the US National Institutes of Health, the Wellcome Trust, the UK Medical Research Council, and the Canadian Institutes of Health Research, either have implemented or are considering open access policies. This will drive greater growth in open access resources, particularly in the area of medicine. There are implications and leadership opportunities for librarians in the open access environment.

Open access is being talked about, and implemented, around the globe, by everyone from the U.N. to individual authors, editors, and publishers, and collaborative groups. As of October 2004, requests for a government mandate for OA had gone forward not only in the U.S. and the U.K., but also Croatia. The Scielo (Scientific Electronic Online) collections of Latin America are very substantial, fully open access journal collections. In the developing world, OA is seen not only as the best means to access the research results of others, but as an opportunity to contribute their own scholarly research findings. Outside the U.S. and the U.K., profits from scientific publishing are not common, and subsidies are not unusual. The author predicts that the present slow but steady growth in institutional repositories will be replaced in the near future by dramatic growth.

This article discusses the benefits of Open Access to library literature. It cites examples of library associations practicing Open Access.

Commodity markets are fundamentally cyclical, exposing mining companies to large swings in profitability during periods of economic boom and bust. Although this is well documented, companies continue to produce mine plans based on present market conditions that fail to acknowledge long-term metal price variability. The purpose of this thesis is to adapt McIsaac’s (2008) mathematical model for determining the most robust underground mining plan under conditions of metal price uncertainty for application in an open pit environment. An overview of conventional open pit algorithms is given to demonstrate that a circular analysis precludes the determination of an optimal solution when metal prices are uncertain. Under the proposed methodology, the optimal solution is achieved by selecting the cutoff grade and production rate under stochastic metal prices such that the net present value and probability of a positive net present value are maximized. The mathematical model was formulated with costs represented as a function of the level of production, rate of production or both. Revenues are achieved from either a mill, heap leach or stockpile process dependent on the level of production and metal price in the year of consideration. Metal prices are generated annually according to a stochastic model that balances short-term volatility with long-term trends. The compiled cash flow model determines the optimal net present value for a given production profile under input metal prices. The feasible area of production is established based on mine life, resource and financing constraints. Net present values are generated for a broad search grid, which converges towards a unimodal solution according to a golden search algorithm. The process is then repeated many times in order to identify the production profile at which the optimal solution is repeatedly reached. As a visual representation, the solutions are plotted on a bubble graph where the size of the bubble corresponds to the frequency of the solution; the largest bubble is associated with the optimal solution. The methodology is tested on two massive copper porphyry deposits, contained within a single claim, for which a Preliminary Economic Assessment has been completed. / Thesis (Master, Mining Engineering) -- Queen's University, 2010-02-08 22:07:52.331

This thesis investigates the following research questions: (1) What is open source project governance and how can it be conceptualized? (2) What is the relationship between the dimensions of OSS governance and the specific purposes that governance is hypothesized to serve in open source projects? (3) How do the major configurations of governance dimensions affect the performance of open source projects? Two studies were conducted to answer these questions: an exploratory qualitative study and a survey study. In the qualitative study, we clearly defined, developed, and validated the various dimensions of OSS governance. This allowed for the identification of a limited number of configurations of governance dimensions that most frequently occur in open source projects. We found that a patterning in governance dimensions takes place because dimensions are in fact interdependent. Therefore, only a fraction of the theoretically conceivable configurations of governance dimensions appear to be viable and were observed among a range of open source projects. This provided us with a preliminary understanding of how these dimensions configure to create three distinct configurations of project governance which were labeled as follows: Open Communities, Managed Communities, and Defined Communities. In the quantitative survey, we first validated these configurations of governance using cluster analysis and then tested the relationships between these configurations (clusters) and the specific purposes that governance is hypothesized to serve in open source projects, namely solve collective action dilemmas, solve coordination problems, and create a climate for project excellence, while assessing their influence on the performance of projects. The results confirmed the presence of three main governance configurations (clusters) and also showed that open source projects that adopt a Defined Community approach to governance were the most successful. In these types of projects, the combination of a tightly managed software development process with a decentralized community management structure was found to create a balance between anarchy and control that allows these projects to benefit from one of the virtues of open source development, the open contribution and participation of a wide variety of talented developers, while avoiding the pitfalls of an uncontrolled and scattered development process. / Thesis (Ph.D, Management) -- Queen's University, 2012-04-11 16:00:02.186

Despite the prominent role played by open tubular columns in gas chromatography, they have enjoyed comparatively little success as supports for open tubular liquid chromatography (OTLC), owing to impractical channel diameters (3-5 μm) required to facilitate retention in the liquid phase. In an effort to circumvent the technical issues associated with such narrow diameters, columns with multiple parallel channels have been suggested as alternatives – to this end, micro-structured fibres (MSFs) have been proposed as supports for OTLC. Much research has been conducted using MSFs for chromatography in the Oleschuk group, and although some success has been achieved, performance has been continuously hindered by flow velocity variation among the channels stemming from differences in channel sizes (or channel variance) as well as differences in stationary phase coverage, which serve to degrade column efficiency. Recent efforts have focused on devising a novel method for assessing the channel variance of MSFs. This method seeks to determine hole tolerance through evaluation of the extent of band broadening that occurs when performing chromatography in the absence of a retentive mechanism. Using this method, a linear correlation between the relative standard deviation of the channel diameters and the amount of broadening was revealed. To supplement the results, computational fluid dynamics was employed to simulate fluid flow through multi-channel columns. The results of these simulations again provided a linear correlation between the RSD of the channel diameters and the extent of flow velocity variation among the channels. / Thesis (Master, Chemistry) -- Queen's University, 2012-08-15 11:57:28.915

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