10 research outputs found

    Arogyasree: An Enhanced Grid-Based Approach to Mobile Telemedicine

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    A typical telemedicine system involves a small set of hospitals providing remote healthcare services to a small section of the society using dedicated nodal centers. However, in developing nations like India where majority live in rural areas that lack specialist care, we envision the need for much larger Internet-based telemedicine systems that would enable a large pool of doctors and hospitals to collectively provide healthcare services to entire populations. We propose a scalable, Internet-based P2P architecture for telemedicine integrating multiple hospitals, mobile medical specialists, and rural mobile units. This system, based on the store and forward model, features a distributed context-aware scheduler for providing timely and location-aware telemedicine services. Other features like zone-based overlay structure and persistent object space abstraction make the system efficient and easy to use. Lastly, the system uses the existing internet infrastructure and supports mobility at doctor and patient ends

    Two-layered architecture for peer-to-peer concept search

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    The current search landscape consists of a small number of centralized search engines posing serious issues including centralized control, resource scalability, power consumption and inability to handle long tail of user interests. Since, the major search engines use syntactic search techniques, the quality of search results are also low, as the meanings of words are not considered effectively. A collaboratively managed peer-to-peer semantic search engine realized using the edge nodes of the internet could address most of the issues mentioned. We identify the issues related to knowledge management, word-to-concept mapping and efficiency in realizing a peer-to-peer concept search engine, which extends syntactic search with background knowledge of peers and searches based on concepts rather than words. We propose a two-layered architecture for peer-to-peer concept search to address the identified issues. In the two-layered approach, peers are organized into communities and background knowledge and document index are maintained at two levels. Universal knowledge is used to identify the appropriate communities for a query and search within the communities proceed based on the background knowledge developed independently by the communities. We developed proof-of-concept implementations of peer-to-peer syntactic search, straightforward single-layered and the proposed two-layered peer-to-peer concept search approaches. Our evaluation concludes that the proposed two-layered approach improves the quality and network efficiency substantially compared to a straightforward single-layered approach

    Keep the PokerFace on! Thwarting cache side channel attacks by memory bus monitoring and cache obfuscation

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    Abstract Cloud instances are vulnerable to cross-core, cross-VM attacks against the shared, inclusive last-level cache. Automated cache template attacks, in particular, are very powerful as the vulnerabilities do not need to be manually identified. Such attacks can be devised using both the Prime+Probe and the Flush+Reload techniques. In this paper, we present PokerFace, a novel method to identify and mitigate such attacks. This approach allows us to identify suspicious cache accesses automatically, without prior knowledge about the system or access to hardware metrics. PokerFace consists of two components, Poker and Face. Poker executes a memory bus benchmark to measure the available bus bandwidth and derive information about cache accesses and possible side channel attacks. Our experiments with cache attacks show a reduction of up to 14% in the memory bandwidth during the attack. When an attack is detected, Poker triggers Face which performs cache obfuscation. We demonstrate the effectiveness of our approach against keypress logging attacks. We also test it against generic Prime+Probe and Flush+Reload attacks and show that it is practically useful against a variety of cache timing attacks. PokerFace incurs modest overheads (< 8%) and moreover, does not require support from the cloud provider or changes to the hypervisor. Unlike previously proposed techniques, it can be implemented by cloud subscribers

    Psi-CAL: Foundations of a Programming Language for Services Computing

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    Services Computing has turned into the mainstream programming paradigm for building enterprise systems that are distributed in nature. However, the programming power available to the developers of service oriented systems has been slow to catch up. The object abstraction continues to be the prevalent mechanism for implementing services based software systems and has several drawbacks. A key drawback is the fact that programmers are provided the business requirements in terms of services but are expected to implement them using objects, leading to an abstraction gap that the programmer is expected to fill. In this paper, we formalize the notion of services as first class entities through a typed calculus, called Psi-CAL. Psi-CAL models major operations for service manipulation including creation, discovery, and invocation as well as establishing relationships among services. We present the syntax and semantics of Psi-CAL with a corresponding type system, towards building a programming language for services computing

    Xi-Calculus: A Calculus for Service Interactions

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    The paper proposes ξ-calculus, a formalism for describing interactions in Service Oriented Architectures. The calculus treats interactions between services as a core concept to capture important architectural characteristics of the system. The focus of ξ-calculus is on the higher level abstraction rather than on the lower level details like parameter passing, use of stacks, closures etc. And hence it can be used to specify, study, and compare different service oriented systems from an architectural point of view. The paper also introduces a notion of interaction types suitable for the level of abstraction under consideration. These types are used to describe the type system of the calculus. The paper introduces a notion of design time non-functional capabilities and also present the application of the calculus in a real business scenario

    KAAS: Kernel as a Service

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    Advances in cloud computing have led to advances in infrastructure, platforms and user applications. But the operating system space hasn't really kept pace with these advancements. In this paper we propose a model for cloud OS with Kernel As A Service (KAAS) offering. We describe the notion of KAAS and use it as a building block for developing Cloud OS. The KAAS model serves as the basic enabler for cross kernel switching, this offers an attractive set of possibilities like load balancing across kernels, fault resilience against kernel failures etc. The design, implementation and performance study of the this Cloud Operating System (SICLOPS) is presented in the paper
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