Identifying, Quantifying, Extracting and Enhancing Implicit Parallelism

The shift of the microprocessor industry towards multicore architectures has placed a huge burden on the programmers by requiring explicit parallelization for performance. Implicit Parallelization is an alternative that could ease the burden on programmers by parallelizing applications ???under the covers??? while maintaining sequential semantics externally. This thesis develops a novel approach for thinking about parallelism, by casting the problem of parallelization in terms of instruction criticality. Using this approach, parallelism in a program region is readily identified when certain conditions about fetch-criticality are satisfied by the region. The thesis formalizes this approach by developing a criticality-driven model of task-based parallelization. The model can accurately predict the parallelism that would be exposed by potential task choices by capturing a wide set of sources of parallelism as well as costs to parallelization. The criticality-driven model enables the development of two key components for Implicit Parallelization: a task selection policy, and a bottleneck analysis tool. The task selection policy can partition a single-threaded program into tasks that will profitably execute concurrently on a multicore architecture in spite of the costs associated with enforcing data-dependences and with task-related actions. The bottleneck analysis tool gives feedback to the programmers about data-dependences that limit parallelism. In particular, there are several ???accidental dependences??? that can be easily removed with large improvements in parallelism. These tools combine into a systematic methodology for performance tuning in Implicit Parallelization. Finally, armed with the criticality-driven model, the thesis revisits several architectural design decisions, and finds several encouraging ways forward to increase the scope of Implicit Parallelization.unpublishednot peer reviewe

Use of transportation relays to improve private fleet management

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2009.Includes bibliographical references (leaf 53).We explore the use of transportation relays, a somewhat unconventional transportation operations concept, in terms of improving private fleet management. A transportation relay is a shipment that is divided into two legs. With transportation relays, there is more ways to route freight with a private fleet. We use a linear program to find private fleet tours with and without relays for a large retailer. We find that relays increase private fleet use by 17% and reduce total transportation cost by 6%. Inbound relays increase the utilization of private fleet on the inbound lanes while outbound relays shift the private fleet capacity between neighboring DCs. Together, inbound and outbound relays better utilize existing private fleet resources and can be used to justify an investment in a larger private fleet through the purchase of addition tractors and trailers.by John Tsu and Mayank Agarwal.M.Eng.in Logistic

Moving in next door: Network flooding as a side channel in cloud environments

The final publication is available at http://link.springer.com/chapter/10.1007/978-3-319-48965-0_56Co-locating multiple tenants' virtual machines (VMs) on the same host underpins public clouds' affordability, but sharing physical hardware also exposes consumer VMs to side channel attacks from adversarial co-residents. We demonstrate passive bandwidth measurement to perform traffic analysis attacks on co-located VMs. Our attacks do not assume a privileged position in the network or require any communication between adversarial and victim VMs. Using a single feature in the observed bandwidth data, our algorithm can identify which of 3 potential YouTube videos a co-resident VM streamed with 66% accuracy. We discuss defense from both a cloud provider's and a consumer's perspective, showing that effective defense is difficult to achieve without costly under-utilization on the part of the cloud provider or over-utilization on the part of the consumer.We would like to acknowledge the MIT PRIMES program and thank in particular Dr. Slava Gerovitch and Dr. Srini Devadas for their support. We are also grateful to Boston University, the Hariri Institute, and the Massachusetts Open Cloud. This paper is based upon work supported by the National Science Foundation under Grants No. 1414119 and 1413920

Carolina Data Warehouse for Delivering Better Healthcare

With the emergence of Clinical and Translational Science Awards (CTSA) there has been increased focus on integrating medical research with the informatics practice to improve the delivery of health care. This paper presents a general overview of the field of data warehouse, the challenges that arise while implementing a data warehouse, and then highlight the important factors to be considered while implementing a data warehouse. The paper goes on to describe the field of clinical data warehouse and address some of the challenges in implementing a clinical data warehouse. Carolina Data Warehouse (CDW-H) is described as a fully implemented in use example of a clinical data warehouse and various issues around clinical data warehouse are explained using CDWH. Research portal is used as an example to illustrate the flexibility offered by CDW-H to build new services on top of it. New services that can be built on CDW-H are suggested based on literature survey

Association of X-Efficiency to Share Prices of Banks in India – An Empirical Evidence.

In this article we have determined the cost efficiency of top 20 listed commercial banks of India using SFA approach. then using System-GMM we have determined the relationship between cost efficiency and share prices of the banks