229 research outputs found

    Experience with the CAIS

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    Intermetrics' experience is that the Ada package construct, which allows separation of specification and implementation allows specification of a CAIS that is transportable across varying hardware and software bases. Additionally, the CAIS is an excellent basis for providing operating system functionality to Ada applications. By allowing the Byron APSE to be moved easily from system to system, and allowing significant re-writes of underlying code. Ada and the CAIS provide portability as well as transparency to change at the application operating system interface level

    Advances in Dynamic Virtualized Cloud Management

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    Cloud computing continues to gain in popularity, with more and more applications being deployed into public and private clouds. Deploying an application in the cloud allows application owners to provision computing resources on-demand, and scale quickly to meet demand. An Infrastructure as a Service (IaaS) cloud provides low-level resources, in the form of virtual machines (VMs), to clients on a pay-per-use basis. The cloud provider (owner) can reduce costs by lowering power consumption. As a typical server can consume 50% or more of its peak power consumption when idle, this can be accomplished by consolidating client VMs onto as few hosts (servers) as possible. This, however, can lead to resource contention, and degraded VM performance. As such, VM placements must be dynamically adapted to meet changing workload demands. We refer to this process as dynamic management. Clients should also take advantage of the cloud environment by scaling their applications up and down (adding and removing VMs) to match current workload demands. This thesis proposes a number of contributions to the field of dynamic cloud management. First, we propose a method of dynamically switching between management strategies at run-time in order to achieve more than one management goal. In order to increase the scalability of dynamic management algorithms, we introduce a distributed version of our management algorithm. We then consider deploying applications which consist of multiple VMs, and automatically scale their deployment to match their workload. We present an integrated management algorithm which handles both dynamic management and application scaling. When dealing with multi-VM applications, the placement of communicating VMs within the data centre topology should be taken into account. To address this consideration, we propose a topology-aware version of our dynamic management algorithm. Finally, we describe a simulation tool, DCSim, which we have developed to help evaluate dynamic management algorithms and techniques

    Diagnosis in Policy-Based Autonomic Management

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    Policy-based Autonomic Management monitors a system and its applications and tweaks performance parameters in real-time based on a set of governing policies. A policy specifies a set of conditions under which one or more of a set of actions are to be performed. It is very common that multiple policies’ conditions are met simultaneously, each advocating many actions. Deciding which action to perform is a non-trivial task. We propose a method of diagnosing the system to try to determine the best action or actions to perform in a given situation using Abductive Inference. We develop an original method of building a causality graph to facilitate diagnosis directly from a set of policies. Performance of the diagnosis method is measured by implementing diagnosis into an existing autonomic management application and monitoring the performance of a LAMP (Linux, Apache, MySQL, PHP) server being governed by the manager. The results are favourable when compared to previous methods of action selection and to the server running without the autonomic manager

    The Rise and Fall of New Bedford Whaling, as Documented by the Whalemen\u27s Shipping List and Merchants\u27 Transcript

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    The purpose of this study is to document the rise and fall of the New Bedford whaling industry-which was, in effect, the American whaling industry-through the pages of the Whalemen\u27s Shipping List and Merchants\u27 Transcript. This analysis will proceed int he following ways. First, this study will detail the origins of the American whaling industry and it development up to the first issue of the Whalemen\u27s Shipping List and Merchants\u27 Transcript on March 17, 1843. Whaling developed in colonial American because many of thos first settlers previously worked in the English and Dutch whaling fleets. This section also will include a history of New Bedford and its emergence as the world\u27s leading whaling port. Second, this study will place the appearance of the Whalemen\u27s Shipping List and merchants\u27 Transcript in the context of the development of the American business press. Third, this study will examine the coverage by the Whalemen\u27s Shipping List and Merchants\u27 Transcript of the later years of whaling\u27s Golden Age. Finally, this study will examine the fall of the New Bedford and American whaling industry through the pages of the Whalemen\u27s Shipping List and Merchants\u27 Transcript

    Identification of an alternative G{alpha}q-dependent chemokine receptor signal transduction pathway in dendritic cells and granulocytes

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    CD38 controls the chemotaxis of leukocytes to some, but not all, chemokines, suggesting that chemokine receptor signaling in leukocytes is more diverse than previously appreciated. To determine the basis for this signaling heterogeneity, we examined the chemokine receptors that signal in a CD38-dependent manner and identified a novel "alternative" chemokine receptor signaling pathway. Similar to the "classical" signaling pathway, the alternative chemokine receptor pathway is activated by G{alpha}i2-containing Gi proteins. However, unlike the classical pathway, the alternative pathway is also dependent on the Gq class of G proteins. We show that G{alpha}q-deficient neutrophils and dendritic cells (DCs) make defective calcium and chemotactic responses upon stimulation with N-formyl methionyl leucyl phenylalanine and CC chemokine ligand (CCL) 3 (neutrophils), or upon stimulation with CCL2, CCL19, CCL21, and CXC chemokine ligand (CXCL) 12 (DCs). In contrast, G{alpha}q-deficient T cell responses to CXCL12 and CCL19 remain intact. Thus, the alternative chemokine receptor pathway controls the migration of only a subset of cells. Regardless, the novel alternative chemokine receptor signaling pathway appears to be critically important for the initiation of inflammatory responses, as G{alpha}q is required for the migration of DCs from the skin to draining lymph nodes after fluorescein isothiocyanate sensitization and the emigration of monocytes from the bone marrow into inflamed skin after contact sensitization

    A distributed approach to dynamic vm management

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    Abstract-Computing today is increasingly moving into largescale virtualized data centres, offering computing resources in the form of virtual machines (VMs) on a pay-per-usage basis. In order to minimize costs, VMs should be consolidated on as few physical machines (PMs) as possible, switching idle PMs into a power saving mode. It may be necessary to dynamically allocate and reallocate VMs to PMs in order to meet highly dynamic VM resource requirements. The problem of assigning VMs to PMs is known to be NP-Hard. Most solutions focus on a centralized approach, with a single management node making allocation decisions periodically. This approach suffers from poor scalability and the existence of a single point of failure. We present a fully distributed approach to dynamic VM management, and evaluate our approach using a simulation tool. Results indicate that the distributed approach can achieve similar performance to the centralized solution, while eliminating the single point of failure and reducing the network bandwidth required for management

    Reapplication Of Turbomachinery.

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    LecturePg. 111-120The reapplication of equipment can be attractive and rewarding when the proper situation warrants. The main factors that encourage consideration of this path can include simple economics, convenience, or possibly a more expeditious route for a project. This also offers lower risk when the equipment is known and proven. Reapplying equipment can produce significant savings of capital project funds which equates to immediate gains, as well as the reward of accelerated returns due to a shorter schedule. However, the probability of finding a perfect match for a new application is remote, and hence, a redesign is normally required. Various options the end-user can consider in performing redesign work are reviewed, along with the logic that supports the various options, the requirements and paths to be considered. Example case studies will be examined

    The SOAR Optical Imager

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    The SOAR Optical Imager (SOI) is the commissioning instrument for the 4.2-m SOAR telescope, which is sited on Cerro Pachón, and due for first light in April 2003. It is being built at Cerro Tololo Inter-American Observatory, and is one of a suite of first-light instruments being provided by the four SOAR partners (NOAO, Brazil, University of North Carolina, Michigan State University). The instrument is designed to produce precision photometry and to fully exploit the expected superb image quality of the SOAR telescope, over a 6x6 arcmin field. Design goals include maintaining high throughput down to the atmospheric cut-off, and close reproduction of photometric passbands throughout 310-1050nm. The focal plane consists of a two-CCD mosaic of 2Kx4K Lincoln Labs CCDs, following an atmospheric dispersion corrector, focal reducer, and tip-tilt sensor. Control and data handling are within the LabVIEW-Linux environment used throughout the SOAR Project

    Simple stereo matching algorithm for localising keypoints in a restricted search space

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    Modern stereo matching algorithms generally rely on matching image features such as colour and texture to find corresponding matches between images. They can provide very good results but be very computationally intensive. However, in cases where the objects to be localised lie approximately on a known plane, a much simpler algorithm can be applied. One such case is localising kiwifruit in modern orchards, as the plants are trained to grow in a planar structure known as a pergola. The proposed algorithm uses tight distance limits (based on orchard geometry) to reduce the search space for matching fruit to a small window. For the majority of kiwifruit, the search window is small enough to contain only one fruit in the adjacent image, giving only a single solution. In cases where there are tightly grouped fruit or false positive fruit detections adjacent to true positive fruit detections, there can be multiple potential matching solutions. To solve these, each potential solution is evaluated based on how closely it conforms to the mean object distance from camera and a solution is selected. On real world test data containing 121 image pairs, the algorithm has a 99.2 % true positive rate. Computation time was 1.97 ms per image pair
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