14,445 research outputs found
Executing Bag of Distributed Tasks on the Cloud: Investigating the Trade-offs Between Performance and Cost
Bag of Distributed Tasks (BoDT) can benefit from decentralised execution on
the Cloud. However, there is a trade-off between the performance that can be
achieved by employing a large number of Cloud VMs for the tasks and the
monetary constraints that are often placed by a user. The research reported in
this paper is motivated towards investigating this trade-off so that an optimal
plan for deploying BoDT applications on the cloud can be generated. A heuristic
algorithm, which considers the user's preference of performance and cost is
proposed and implemented. The feasibility of the algorithm is demonstrated by
generating execution plans for a sample application. The key result is that the
algorithm generates optimal execution plans for the application over 91\% of
the time
CamFlow: Managed Data-sharing for Cloud Services
A model of cloud services is emerging whereby a few trusted providers manage
the underlying hardware and communications whereas many companies build on this
infrastructure to offer higher level, cloud-hosted PaaS services and/or SaaS
applications. From the start, strong isolation between cloud tenants was seen
to be of paramount importance, provided first by virtual machines (VM) and
later by containers, which share the operating system (OS) kernel. Increasingly
it is the case that applications also require facilities to effect isolation
and protection of data managed by those applications. They also require
flexible data sharing with other applications, often across the traditional
cloud-isolation boundaries; for example, when government provides many related
services for its citizens on a common platform. Similar considerations apply to
the end-users of applications. But in particular, the incorporation of cloud
services within `Internet of Things' architectures is driving the requirements
for both protection and cross-application data sharing.
These concerns relate to the management of data. Traditional access control
is application and principal/role specific, applied at policy enforcement
points, after which there is no subsequent control over where data flows; a
crucial issue once data has left its owner's control by cloud-hosted
applications and within cloud-services. Information Flow Control (IFC), in
addition, offers system-wide, end-to-end, flow control based on the properties
of the data. We discuss the potential of cloud-deployed IFC for enforcing
owners' dataflow policy with regard to protection and sharing, as well as
safeguarding against malicious or buggy software. In addition, the audit log
associated with IFC provides transparency, giving configurable system-wide
visibility over data flows. [...]Comment: 14 pages, 8 figure
Workflow Partitioning and Deployment on the Cloud using Orchestra
Orchestrating service-oriented workflows is typically based on a design model
that routes both data and control through a single point - the centralised
workflow engine. This causes scalability problems that include the unnecessary
consumption of the network bandwidth, high latency in transmitting data between
the services, and performance bottlenecks. These problems are highly prominent
when orchestrating workflows that are composed from services dispersed across
distant geographical locations. This paper presents a novel workflow
partitioning approach, which attempts to improve the scalability of
orchestrating large-scale workflows. It permits the workflow computation to be
moved towards the services providing the data in order to garner optimal
performance results. This is achieved by decomposing the workflow into smaller
sub workflows for parallel execution, and determining the most appropriate
network locations to which these sub workflows are transmitted and subsequently
executed. This paper demonstrates the efficiency of our approach using a set of
experimental workflows that are orchestrated over Amazon EC2 and across several
geographic network regions.Comment: To appear in Proceedings of the IEEE/ACM 7th International Conference
on Utility and Cloud Computing (UCC 2014
Child and Family Welfare in Sweden
Sweden has no special Children’s Act because regulations on children are included in the Social Services Act from 1980, supplemented by an act regulating compulsory care. Child and Family welfare has a family support orientation rather than a child protection orientation. No time limit provided by the law put an end to family support or out-of-home care, but interventions are reviewed every six months. The paper presents some facts about Sweden, gives and overview of the legal framework, family maintenance services and out-of-home care. Further details are given about contact person/family as one of the most frequently used statutory support services for children and families. As an example of the decentralised social services in Sweden, the organisation of child and family welfare in the district of Rosengaard in the city of Malmoe is described. The paper ends with reflections and debated issues in child and family welfare in Sweden
A new paradigm for SpeckNets:inspiration from fungal colonies
In this position paper, we propose the development of a new biologically inspired paradigm based on fungal colonies, for the application to pervasive adaptive systems. Fungal colonies have a number of properties that make them an excellent candidate for inspiration for engineered systems. Here we propose the application of such inspiration to a speckled computing platform. We argue that properties from fungal colonies map well to properties and requirements for controlling SpeckNets and suggest that an existing mathematical model of a fungal colony can developed into a new computational paradigm
Preferences and skills of Indian public sector teachers
With a sample of 700 future public sector primary teachers in India, a Discrete Choice Experiment is used to measure job preferences, particularly regarding location. General skills are also tested. Urban origin teachers and women are more averse to remote locations than rural origin teachers and men respectively. Women would require a 26-73 percent increase in salary for moving to a remote location. The results suggest that existing caste and gender quotas can be detrimental for hiring skilled teachers willing to work in remote locations. The most preferred location is home, which supports decentralised hiring, although this could compromise skills
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