25,668 research outputs found
Path Selection for Quantum Repeater Networks
Quantum networks will support long-distance quantum key distribution (QKD)
and distributed quantum computation, and are an active area of both
experimental and theoretical research. Here, we present an analysis of
topologically complex networks of quantum repeaters composed of heterogeneous
links. Quantum networks have fundamental behavioral differences from classical
networks; the delicacy of quantum states makes a practical path selection
algorithm imperative, but classical notions of resource utilization are not
directly applicable, rendering known path selection mechanisms inadequate. To
adapt Dijkstra's algorithm for quantum repeater networks that generate
entangled Bell pairs, we quantify the key differences and define a link cost
metric, seconds per Bell pair of a particular fidelity, where a single Bell
pair is the resource consumed to perform one quantum teleportation. Simulations
that include both the physical interactions and the extensive classical
messaging confirm that Dijkstra's algorithm works well in a quantum context.
Simulating about three hundred heterogeneous paths, comparing our path cost and
the total work along the path gives a coefficient of determination of 0.88 or
better.Comment: 12 pages, 8 figure
InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services
Cloud computing providers have setup several data centers at different
geographical locations over the Internet in order to optimally serve needs of
their customers around the world. However, existing systems do not support
mechanisms and policies for dynamically coordinating load distribution among
different Cloud-based data centers in order to determine optimal location for
hosting application services to achieve reasonable QoS levels. Further, the
Cloud computing providers are unable to predict geographic distribution of
users consuming their services, hence the load coordination must happen
automatically, and distribution of services must change in response to changes
in the load. To counter this problem, we advocate creation of federated Cloud
computing environment (InterCloud) that facilitates just-in-time,
opportunistic, and scalable provisioning of application services, consistently
achieving QoS targets under variable workload, resource and network conditions.
The overall goal is to create a computing environment that supports dynamic
expansion or contraction of capabilities (VMs, services, storage, and database)
for handling sudden variations in service demands.
This paper presents vision, challenges, and architectural elements of
InterCloud for utility-oriented federation of Cloud computing environments. The
proposed InterCloud environment supports scaling of applications across
multiple vendor clouds. We have validated our approach by conducting a set of
rigorous performance evaluation study using the CloudSim toolkit. The results
demonstrate that federated Cloud computing model has immense potential as it
offers significant performance gains as regards to response time and cost
saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape
Virtual Reality Games for Motor Rehabilitation
This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion
Buffer Sizing for 802.11 Based Networks
We consider the sizing of network buffers in 802.11 based networks. Wireless
networks face a number of fundamental issues that do not arise in wired
networks. We demonstrate that the use of fixed size buffers in 802.11 networks
inevitably leads to either undesirable channel under-utilization or unnecessary
high delays. We present two novel dynamic buffer sizing algorithms that achieve
high throughput while maintaining low delay across a wide range of network
conditions. Experimental measurements demonstrate the utility of the proposed
algorithms in a production WLAN and a lab testbed.Comment: 14 pages, to appear on IEEE/ACM Transactions on Networkin
The Evaluation of the implementation of WebCT in the Principle of Macroeconomics Class
This paper describes the review of implementation of Blended Learning with WebCT in Principle of Macroeconomics class. The course is conducted at the University of Padjadjaran at second semester in 2005. A questioner and a quantitative data are used to support the importance of those kinds of learning method.Economics education, learning method
Proactive cloud management for highly heterogeneous multi-cloud infrastructures
Various literature studies demonstrated that the cloud computing paradigm can help to improve availability and performance of applications subject to the problem of software anomalies. Indeed, the cloud resource provisioning model enables users to rapidly access new processing resources, even distributed over different geographical regions, that can be promptly used in the case of, e.g., crashes or hangs of running machines, as well as to balance the load in the case of overloaded machines. Nevertheless, managing a complex geographically-distributed cloud deploy could be a complex and time-consuming task. Autonomic Cloud Manager (ACM) Framework is an autonomic framework for supporting proactive management of applications deployed over multiple cloud regions. It uses machine learning models to predict failures of virtual machines and to proactively redirect the load to healthy machines/cloud regions. In this paper, we study different policies to perform efficient proactive load balancing across cloud regions in order to mitigate the effect of software anomalies. These policies use predictions about the mean time to failure of virtual machines. We consider the case of heterogeneous cloud regions, i.e regions with different amount of resources, and we provide an experimental assessment of these policies in the context of ACM Framework
FORGE: An eLearning Framework for Remote Laboratory Experimentation on FIRE Testbed Infrastructure
The Forging Online Education through FIRE (FORGE) initiative provides educators and learners in higher education with access to world-class FIRE testbed infrastructure. FORGE supports experimentally driven research in an eLearning environment by complementing traditional classroom and online courses with interactive remote laboratory experiments. The project has achieved its objectives by defining and implementing a framework called FORGEBox. This framework offers the methodology, environment, tools and resources to support the creation of HTML-based online educational material capable accessing virtualized and physical FIRE testbed infrastruc- ture easily. FORGEBox also captures valuable quantitative and qualitative learning analytic information using questionnaires and Learning Analytics that can help optimise and support student learning. To date, FORGE has produced courses covering a wide range of networking and communication domains. These are freely available from FORGEBox.eu and have resulted in over 24,000 experiments undertaken by more than 1,800 students across
10 countries worldwide. This work has shown that the use of remote high- performance testbed facilities for hands-on remote experimentation can have a valuable impact on the learning experience for both educators and learners. Additionally, certain challenges in developing FIRE-based courseware have been identified, which has led to a set of recommendations in order to support the use of FIRE facilities for teaching and learning purposes
- …