685 research outputs found
Telescience testbed pilot program
The Universities Space Research Association (USRA), under sponsorship from the NASA Office of Space Science and Applications, is conducting a Telescience Testbed Pilot Program. Fifteen universities, under subcontract to USRA, are conducting a variety of scientific experiments using advanced technology to determine the requirements and evaluate the tradeoffs for the information system of the Space Station era. An interim set of recommendations based on the experiences of the first six months of the pilot program is presented
Rumba : a Python framework for automating large-scale recursive internet experiments on GENI and FIRE+
It is not easy to design and run Convolutional Neural Networks (CNNs) due to: 1) finding the optimal number of filters (i.e., the width) at each layer is tricky, given an architecture; and 2) the computational intensity of CNNs impedes the deployment on computationally limited devices. Oracle Pruning is designed to remove the unimportant filters from a well-trained CNN, which estimates the filters’ importance by ablating them in turn and evaluating the model, thus delivers high accuracy but suffers from intolerable time complexity, and requires a given resulting width but cannot automatically find it. To address these problems, we propose Approximated Oracle Filter Pruning (AOFP), which keeps searching for the least important filters in a binary search manner, makes pruning attempts by masking out filters randomly, accumulates the resulting errors, and finetunes the model via a multi-path framework. As AOFP enables simultaneous pruning on multiple layers, we can prune an existing very deep CNN with acceptable time cost, negligible accuracy drop, and no heuristic knowledge, or re-design a model which exerts higher accuracy and faster inferenc
The Glasgow raspberry pi cloud: a scale model for cloud computing infrastructures
Data Centers (DC) used to support Cloud services
often consist of tens of thousands of networked machines under a single roof. The significant capital outlay required to replicate such infrastructures constitutes a major obstacle to practical implementation and evaluation of research in this domain. Currently, most research into Cloud computing relies on either limited software simulation, or the use of a testbed environments
with a handful of machines. The recent introduction of the
Raspberry Pi, a low-cost, low-power single-board computer, has made the construction of a miniature Cloud DCs more affordable.
In this paper, we present the Glasgow Raspberry Pi Cloud
(PiCloud), a scale model of a DC composed of clusters of
Raspberry Pi devices. The PiCloud emulates every layer of a
Cloud stack, ranging from resource virtualisation to network
behaviour, providing a full-featured Cloud Computing research and educational environment
A survey of general-purpose experiment management tools for distributed systems
International audienceIn the field of large-scale distributed systems, experimentation is particularly difficult. The studied systems are complex, often nondeterministic and unreliable, software is plagued with bugs, whereas the experiment workflows are unclear and hard to reproduce. These obstacles led many independent researchers to design tools to control their experiments, boost productivity and improve quality of scientific results. Despite much research in the domain of distributed systems experiment management, the current fragmentation of efforts asks for a general analysis. We therefore propose to build a framework to uncover missing functionality of these tools, enable meaningful comparisons be-tween them and find recommendations for future improvements and research. The contribution in this paper is twofold. First, we provide an extensive list of features offered by general-purpose experiment management tools dedicated to distributed systems research on real platforms. We then use it to assess existing solutions and compare them, outlining possible future paths for improvements
SDN based testbeds for evaluating and promoting multipath TCP
Multipath TCP is an experimental transport proto-
col with remarkable recent past and non-negligible future poten-
tial. It has been standardized recently, however the evaluation
studies focus only on a limited set of isolated use-cases and
a comprehensive analysis or a feasible path of Internet-wide
adoption is still missing. This is mostly because in the current
networking practice it is unusual to configure multiple paths
between the endpoints of a connection. Therefore, conducting and
precisely controlling multipath experiments over the real “inter-
net” is a challenging task for some experimenters and impossible
for others. In this paper, we invoke SDN technology to make
this control possible and exploit large-scale internet testbeds to
conduct end-to-end MPTCP experiments. More specifically, we
establish a special purpose control and measurement framework
on top of two distinct internet testbeds. First, using the OpenFlow
support of GÉANT, we build a testbed enabling measurements
with real traffic. Second, we design and establish a publicly
available large-scale multipath capable measurement framework
on top of PlanetLab Europe and show the challenges of such
a system. Furthermore, we present measurements results with
MPTCP in both testbeds to get insight into its behavior in such
not well explored environment
LTE Spectrum Sharing Research Testbed: Integrated Hardware, Software, Network and Data
This paper presents Virginia Tech's wireless testbed supporting research on
long-term evolution (LTE) signaling and radio frequency (RF) spectrum
coexistence. LTE is continuously refined and new features released. As the
communications contexts for LTE expand, new research problems arise and include
operation in harsh RF signaling environments and coexistence with other radios.
Our testbed provides an integrated research tool for investigating these and
other research problems; it allows analyzing the severity of the problem,
designing and rapidly prototyping solutions, and assessing them with
standard-compliant equipment and test procedures. The modular testbed
integrates general-purpose software-defined radio hardware, LTE-specific test
equipment, RF components, free open-source and commercial LTE software, a
configurable RF network and recorded radar waveform samples. It supports RF
channel emulated and over-the-air radiated modes. The testbed can be remotely
accessed and configured. An RF switching network allows for designing many
different experiments that can involve a variety of real and virtual radios
with support for multiple-input multiple-output (MIMO) antenna operation. We
present the testbed, the research it has enabled and some valuable lessons that
we learned and that may help designing, developing, and operating future
wireless testbeds.Comment: In Proceeding of the 10th ACM International Workshop on Wireless
Network Testbeds, Experimental Evaluation & Characterization (WiNTECH),
Snowbird, Utah, October 201
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