Current Issue : April - June Volume : 2014 Issue Number : 2 Articles : 5 Articles
Cloud computing gives users much freedom on where they host their computation and storage. However the CO2\r\nemission of a job depends on the location and the energy efficiency of the data centers where it is run. We developed\r\na decision framework that determines to move computation with accompanying data from a local to a greener\r\nremote data center for lower CO2 emissions. The model underlying the framework accounts for the energy\r\nconsumption at the local and remote sites, as well as of networks among them. We showed that the type of network\r\nconnecting the two sites has a significant impact on the total CO2 emission. Furthermore, the task�s complexity is a\r\nfactor in deciding when and where to move computation....
The paper presents a survey and analysis of the current security measures implemented in cloud computing and\r\nthe hypervisors that support it. The viability of an efficient virtualization layer has led to an explosive growth in the\r\ncloud computing industry, exemplified by Amazon�s Elastic Cloud, Apple�s iCloud, and Google�s Cloud Platform.\r\nHowever, the growth of any sector in computing often leads to increased security risks. This paper explores these\r\nrisks and the evolution of mitigation techniques in open source cloud computing. Unlike uniprocessor security, the\r\nuse of a large number of nearly identical processors acts as a vulnerability amplifier: a single vulnerability being\r\nreplicated thousands of times throughout the computing infrastructure. Currently, the community is employing a\r\ndiverse set of techniques in response to the perceived risk. These include malware prevention and detection, secure\r\nvirtual machine managers, and cloud resilience. Unfortunately, this approach results in a disjoint response based\r\nmore on detection of known threats rather than mitigation of new or zero-day threats, which are often left\r\nundetected. An alternative way forward is to address this issue by leveraging the strengths from each technique in\r\ncombination with a focus on increasing attacker workload. This approach would make malicious operation time\r\nconsuming and deny persistence on mission time-scales. It could be accomplished by incorporating migration,\r\nnon-determinism, and resilience into the fabric of virtualization....
Cloud computing infrastructures provide a way for researchers to source the computational and storage resources\r\nthey require to conduct their work and to collaborate within distributed research teams. We provide an overview of a\r\ncloud-based elastic virtual infrastructure for research applications that we have established to provide researchers with a\r\ncollaborative research environment that automatically allocates cloud resources as required. We describe how we\r\nhave used this infrastructure to support research on the Sun�s corona and how the elasticity provided by cloud\r\ninfrastructures can be leveraged to provide high-throughput computing resources using a set of off-the-shelf\r\ntechnologies and a small number of additional tools that are simple to deploy and use. The resulting infrastructure\r\nhas a number of advantages for the researchers compared to traditional clusters or grid computing environments that\r\nwe discuss in the conclusions....
The increasing complexity of computer systems has led to the automation of administration functions, in the form of\r\nautonomic managers. Today many autonomic managers are available but they mostly address a specific\r\nadministration aspect which makes necessary their coexistence for a complete autonomic system management.\r\nHowever, coordinating them is necessary for proper and effective global administration. Such coordination can be\r\nconsidered as a problem of synchronization and logical control of managers actions. We therefore investigate the use\r\nof reactive models with events and states, and discrete control techniques to solve this problem. This paper presents\r\nan application of the latter approach for coordinating autonomic managers addressing resource optimization, in the\r\nperspective of green computing. The managers control server provisioning (self-sizing manager) and CPU frequency\r\n(Dvfs manager), and the coordination controller controls the managers actions so as to avoid incoherent\r\nmanagement decisions. The coordination controller is designed using synchronous programming and Discrete\r\ncontroller synthesis (DCS) which are well-suited for the design of reactive systems. Experimental results are presented\r\nto evaluate the efficacy of the approach....
Spectral clustering algorithm has proved be more effective than most traditional algorithms in finding clusters.\r\nHowever, its high computational complexity limits its effect in actual application. This paper combines the spectral\r\nclustering with MapReduce, through evaluation of sparse matrix eigenvalue and computation of distributed cluster,\r\nputs forward the improvement ideas and concrete realization, and thus improves the clustering speed of the\r\ndistinctive clustering algorithm. According to the experiment, with the processing data scale being enlarged, the\r\nclustering rate is in nearly linear growth, and the proposed parallel spectral clustering algorithm is suitable for large\r\ndata mining. The research results provide research basis to better design a clustering partition algorithm in large\r\ndata and high efficiency....
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