14,294 research outputs found
A Framework for QoS-aware Execution of Workflows over the Cloud
The Cloud Computing paradigm is providing system architects with a new
powerful tool for building scalable applications. Clouds allow allocation of
resources on a "pay-as-you-go" model, so that additional resources can be
requested during peak loads and released after that. However, this flexibility
asks for appropriate dynamic reconfiguration strategies. In this paper we
describe SAVER (qoS-Aware workflows oVER the Cloud), a QoS-aware algorithm for
executing workflows involving Web Services hosted in a Cloud environment. SAVER
allows execution of arbitrary workflows subject to response time constraints.
SAVER uses a passive monitor to identify workload fluctuations based on the
observed system response time. The information collected by the monitor is used
by a planner component to identify the minimum number of instances of each Web
Service which should be allocated in order to satisfy the response time
constraint. SAVER uses a simple Queueing Network (QN) model to identify the
optimal resource allocation. Specifically, the QN model is used to identify
bottlenecks, and predict the system performance as Cloud resources are
allocated or released. The parameters used to evaluate the model are those
collected by the monitor, which means that SAVER does not require any
particular knowledge of the Web Services and workflows being executed. Our
approach has been validated through numerical simulations, whose results are
reported in this paper
Recommended from our members
Putting livelihoods thinking into practice: implications for development management.
YesThe failure of `blueprint¿ development interventions to deliver substantive improvements in poverty reduction has been well recognised over the last twenty years. Process approaches seek to overcome the rigidity and top-down operation of much aid-funded intervention. Sustainable livelihoods approaches (SLA) are one of the latest additions to this family of approaches. As a theoretical framework and as a set of principles for guiding intervention, sustainable livelihoods thinking has implications for development management. Drawing on research exploring the application of sustainable livelihoods principles in ten development interventions, this paper considers how these principles have evolved from continuing debates surrounding process and people-centred (bottom-up) approaches to development management. This research suggests that whilst these principles can improve the impact made by interventions, the effective application of sustainable livelihoods and other process approaches are fundamentally restricted by unbalanced power relationships between development partners
Recommended from our members
Goodbye to Projects? Working paper 1: Annotated bibliography on livelihood approaches and development interventions.
YesThis paper is one in a series of working papers prepared under a research project on Goodbye to Projects? The Institutional Impacts of a Livelihood Approach on Projects and Project Cycle Management.
This is a collaborative project between the Bradford Centre for International Centre for Development (BCID) with the Economic and Policy Research Centre (EPRC), Uganda; Khanya ¿ managing rural change, South Africa; and, the Institute for Development Management (IDM), Tanzania. The project is supported by the UK Department for International Development (DFID) under their Economic and Social Research Programme (ESCOR).Department for International Developmen
Energy-Efficient Management of Data Center Resources for Cloud Computing: A Vision, Architectural Elements, and Open Challenges
Cloud computing is offering utility-oriented IT services to users worldwide.
Based on a pay-as-you-go model, it enables hosting of pervasive applications
from consumer, scientific, and business domains. However, data centers hosting
Cloud applications consume huge amounts of energy, contributing to high
operational costs and carbon footprints to the environment. Therefore, we need
Green Cloud computing solutions that can not only save energy for the
environment but also reduce operational costs. This paper presents vision,
challenges, and architectural elements for energy-efficient management of Cloud
computing environments. We focus on the development of dynamic resource
provisioning and allocation algorithms that consider the synergy between
various data center infrastructures (i.e., the hardware, power units, cooling
and software), and holistically work to boost data center energy efficiency and
performance. In particular, this paper proposes (a) architectural principles
for energy-efficient management of Clouds; (b) energy-efficient resource
allocation policies and scheduling algorithms considering quality-of-service
expectations, and devices power usage characteristics; and (c) a novel software
technology for energy-efficient management of Clouds. We have validated our
approach by conducting a set of rigorous performance evaluation study using the
CloudSim toolkit. The results demonstrate that Cloud computing model has
immense potential as it offers significant performance gains as regards to
response time and cost saving under dynamic workload scenarios.Comment: 12 pages, 5 figures,Proceedings of the 2010 International Conference
on Parallel and Distributed Processing Techniques and Applications (PDPTA
2010), Las Vegas, USA, July 12-15, 201
Sustainable product development strategies: Business planning and performance implications
Copyright © 2012 by Institution of Mechanical Engineers. This is the author's accepted manuscript. The final published article is available from the link below.Manufacturing firms are under many financial and competitive pressures which focus attention on the performance of their manufacturing processes. In this paper the opportunities for improving the environmental impact of products within the constraints of existing manufacturing infrastructure are examined. Approaches which support sustainability in two aspects are proposed, firstly, the provision of products to the users in ways which extend the product life and secondly, manufacturing approaches which reduce resource usage. This paper outlines three different sustainable development strategies for different product types and describes the cost implications for manufacturers across the life-cycle. The performance measures affected by these strategies are examined drawing on product development case studies from a number of high technology sectors to highlight the different approaches taken. The results are intended to aid manufacturers during the earliest stages of business planning to consider alternative product development approaches which are more sustainable
Recommended from our members
Sustainable development strategies for product provision and manufacturing approaches
Manufacturing firms are under many pressures both financially and competitive which focus attention on the performance of their manufacturing processes. In this paper the opportunities for improving the environmental impact of products within the constraints of existing manufacturing infrastructure are examined. Approaches which support sustainability in two aspects are proposed, firstly, the provision of products to the users in ways which extend the product life and secondly, manufacturing approaches which reduce resource usage. The provision and manufacture of products in ways that are truly sustainable are inhibited by three issues: firstly, decisions are predominantly made solely from the perspective of the “vendor” (and do not consider the wider perspective); secondly, that generally the scope of business planning is still rooted in production/manufacturing costs (and not consumption costs) and thirdly, the current performance measures (e.g. KPIs) mainly focus on profitability. The rationale for this conference paper is the argument that there is a need to raise the awareness during the earliest stages of business planning that there may be alternative approaches which are more sustainable. The concepts presented here will underpin further research into performance measures which encompass sustainability and resulting business planning implications
End-to-end resource management for federated delivery of multimedia services
Recently, the Internet has become a popular platform for the delivery of multimedia content. Currently, multimedia services are either offered by Over-the-top (OTT) providers or by access ISPs over a managed IP network. As OTT providers offer their content across the best-effort Internet, they cannot offer any Quality of Service (QoS) guarantees to their users. On the other hand, users of managed multimedia services are limited to the relatively small selection of content offered by their own ISP. This article presents a framework that combines the advantages of both existing approaches, by dynamically setting up federations between the stakeholders involved in the content delivery process. Specifically, the framework provides an automated mechanism to set up end-to-end federations for QoS-aware delivery of multimedia content across the Internet. QoS contracts are automatically negotiated between the content provider, its customers, and the intermediary network domains. Additionally, a federated resource reservation algorithm is presented, which allows the framework to identify the optimal set of stakeholders and resources to include within a federation. Its goal is to minimize delivery costs for the content provider, while satisfying customer QoS requirements. Moreover, the presented framework allows intermediary storage sites to be included in these federations, supporting on-the-fly deployment of content caches along the delivery paths. The algorithm was thoroughly evaluated in order to validate our approach and assess the merits of including intermediary storage sites. The results clearly show the benefits of our method, with delivery cost reductions of up to 80 % in the evaluated scenario
Should the advanced measurement approach be replaced with the standardized measurement approach for operational risk?
Recently, Basel Committee for Banking Supervision proposed to replace all
approaches, including Advanced Measurement Approach (AMA), for operational risk
capital with a simple formula referred to as the Standardised Measurement
Approach (SMA). This paper discusses and studies the weaknesses and pitfalls of
SMA such as instability, risk insensitivity, super-additivity and the implicit
relationship between SMA capital model and systemic risk in the banking sector.
We also discuss the issues with closely related operational risk
Capital-at-Risk (OpCar) Basel Committee proposed model which is the precursor
to the SMA. In conclusion, we advocate to maintain the AMA internal model
framework and suggest as an alternative a number of standardization
recommendations that could be considered to unify internal modelling of
operational risk. The findings and views presented in this paper have been
discussed with and supported by many OpRisk practitioners and academics in
Australia, Europe, UK and USA, and recently at OpRisk Europe 2016 conference in
London
- …