886,563 research outputs found
Efficient Quantum Transforms
Quantum mechanics requires the operation of quantum computers to be unitary,
and thus makes it important to have general techniques for developing fast
quantum algorithms for computing unitary transforms. A quantum routine for
computing a generalized Kronecker product is given. Applications include
re-development of the networks for computing the Walsh-Hadamard and the quantum
Fourier transform. New networks for two wavelet transforms are given. Quantum
computation of Fourier transforms for non-Abelian groups is defined. A slightly
relaxed definition is shown to simplify the analysis and the networks that
computes the transforms. Efficient networks for computing such transforms for a
class of metacyclic groups are introduced. A novel network for computing a
Fourier transform for a group used in quantum error-correction is also given.Comment: 30 pages, LaTeX2e, 7 figures include
A threshold secure data sharing scheme for federated clouds
Cloud computing allows users to view computing in a new direction, as it uses
the existing technologies to provide better IT services at low-cost. To offer
high QOS to customers according SLA, cloud services broker or cloud service
provider uses individual cloud providers that work collaboratively to form a
federation of clouds. It is required in applications like Real-time online
interactive applications, weather research and forecasting etc., in which the
data and applications are complex and distributed. In these applications secret
data should be shared, so secure data sharing mechanism is required in
Federated clouds to reduce the risk of data intrusion, the loss of service
availability and to ensure data integrity. So In this paper we have proposed
zero knowledge data sharing scheme where Trusted Cloud Authority (TCA) will
control federated clouds for data sharing where the secret to be exchanged for
computation is encrypted and retrieved by individual cloud at the end. Our
scheme is based on the difficulty of solving the Discrete Logarithm problem
(DLOG) in a finite abelian group of large prime order which is NP-Hard. So our
proposed scheme provides data integrity in transit, data availability when one
of host providers are not available during the computation.Comment: 8 pages, 3 Figures, International Journal of Research in Computer
Science 2012. arXiv admin note: text overlap with arXiv:1003.3920 by other
author
Spatiotemporal Multicast and Partitionable Group Membership Service
The recent advent of wireless mobile ad hoc networks and sensor networks creates many opportunities and challenges. This thesis explores some of them. In light of new application requirements in such environments, it proposes a new multicast paradigm called spatiotemporal multicast for supporting ad hoc network applications which require both spatial and temporal coordination. With a focus on a special case of spatiotemporal multicast, called mobicast, this work proposes several novel protocols and analyzes their performances. This dissertation also investigates implications of mobility on the classical group membership problem in distributed computing, proposes a new speciïŹcation for a partitionable group membership service catering to applications on wireless mobile ad hoc networks, and provides a mobility-aware algorithm and middleware for this service. The results of this work bring new insights into the design and analysis of spatiotemporal communication protocols and fault-tolerant computing in wireless mobile ad hoc networks
Mobile support in CSCW applications and groupware development frameworks
Computer Supported Cooperative Work (CSCW) is an established subset of the field of Human Computer Interaction that deals with the how people use computing technology to enhance group interaction and collaboration. Mobile CSCW has emerged as a result of the progression from personal desktop computing to the mobile device platforms that are ubiquitous today.
CSCW aims to not only connect people and facilitate communication through using computers; it aims to provide conceptual models coupled with technology to manage, mediate, and assist collaborative processes. Mobile CSCW research looks to fulfil these aims through the adoption of mobile technology and consideration for the mobile user. Facilitating collaboration using mobile devices brings new challenges. Some of these challenges are inherent to the nature of the device hardware, while others focus on the understanding of how to engineer software to maximize effectiveness for the end-users. This paper reviews seminal and state-of-the-art cooperative software applications and development frameworks, and their support for mobile devices
The Scaled-Charge Additive Force Field for Amino Acid Based Ionic Liquids
Abstract. Ionic liquids (ILs) constitute an emerging field of research. New
ILs are continuously introduced involving more and more organic and inorganic
ions. Amino acid based ILs (AAILs) represent a specific interest due to their
evolutional connection to proteins. We report a new non- polarizable force
field (FF) for the eight AAILs comprising 1-ethyl-3-methylimidazolium cation
and amino acid anions. The anions were obtained via deprotonation of carboxyl
group. Specific cation-anion non-covalent interactions have been taken into
account by computing electrostatic potential for ion pairs, in contrast to
isolated ions. The van der Waals interactions have been transferred from the
CHARMM36 FF with minor modifications. Therefore, compatibility between our
parameters and CHARMM36 parameters is preserved. Our FF can be easily
implemented using a variety of popular molecular dynamics programs. It will
find broad applications in computational investigation of ILs
c-Theorem for Disordered Systems
We find an analog of Zamolodchikov's c-theorem for disordered two dimensional
noninteracting systems in their supersymmetric representation. For this purpose
we introduce a new parameter b which flows along the renormalization group
trajectories much like the central charge for unitary two dimensional field
theories. However, it is not known yet if this flow is irreversible. b turns
out to be related to the central extension of a certain algebra, a
generalization of the Virasoro algebra, which we show may be present at the
critical points of these theories. b is also related to the physical free
energy of the disordered system defined on a cylinder. We discuss possible
applications by computing b for two dimensional Dirac fermions with random
gauge potential.Comment: 7 page
PonyGE2: Grammatical Evolution in Python
Grammatical Evolution (GE) is a population-based evolutionary algorithm,
where a formal grammar is used in the genotype to phenotype mapping process.
PonyGE2 is an open source implementation of GE in Python, developed at UCD's
Natural Computing Research and Applications group. It is intended as an
advertisement and a starting-point for those new to GE, a reference for
students and researchers, a rapid-prototyping medium for our own experiments,
and a Python workout. As well as providing the characteristic genotype to
phenotype mapping of GE, a search algorithm engine is also provided. A number
of sample problems and tutorials on how to use and adapt PonyGE2 have been
developed.Comment: 8 pages, 4 figures, submitted to the 2017 GECCO Workshop on
Evolutionary Computation Software Systems (EvoSoft
Pervasive CSCW for smart spaces communities
Future pervasive environments will take into consideration not only individual users' interest, but also social relationships. In today's scenarios, the trend is to make use of collective intelligence, where the interpretation of context information can be harnessed as input for pervasive systems. Therefore, social CSCW applications represent new challenges and possibilities in terms of use of group context information for adaptability and personalization in pervasive computing. The objective of this paper is to present two enterprise scenarios that support collaboration and adaption capabilities through pervasive communities combined with social computing. Collaborative applications integrated with pervasive communities can increase the activity's quality of the end user in a wide variety of tasks
- âŠ