1,287 research outputs found
Traffic Engineering with Segment Routing: SDN-based Architectural Design and Open Source Implementation
Traffic Engineering (TE) in IP carrier networks is one of the functions that
can benefit from the Software Defined Networking paradigm. By logically
centralizing the control of the network, it is possible to "program" per-flow
routing based on TE goals. Traditional per-flow routing requires a direct
interaction between the SDN controller and each node that is involved in the
traffic paths. Depending on the granularity and on the temporal properties of
the flows, this can lead to scalability issues for the amount of routing state
that needs to be maintained in core network nodes and for the required
configuration traffic. On the other hand, Segment Routing (SR) is an emerging
approach to routing that may simplify the route enforcement delegating all the
configuration and per-flow state at the border of the network. In this work we
propose an architecture that integrates the SDN paradigm with SR-based TE, for
which we have provided an open source reference implementation. We have
designed and implemented a simple TE/SR heuristic for flow allocation and we
show and discuss experimental results.Comment: Extended version of poster paper accepted for EWSDN 2015 (version v4
- December 2015
Utilising applied behavioural research to execute subsidy reform in Kuwait
The Kuwait government is highly dependent on oil revenues; its fiscal position is exposed to fluctuations in crude oil prices. Reducing expenditures will make Kuwaitâs government more fiscally robust in the context of volatile oil markets. Reforming subsides is one way by which the government can reduce expenditures. Electricity and water subsidies in Kuwait represent about 11â20 percent of fiscal expenditures. The goal of this paper is to identify behavioural interventions, ânudgesâ, that could help save electricity in the household sector, which consumes 50 percent of electricity produced. We developed the nudges by first, reviewing relevant behavioural literature; second, conducting focus group interviews; third, comparing Kuwait to other Gulf Cooperation Council countries; and last, testing the cultural appropriateness of the nudges. The first nudge we propose is making the government subsidy more salient for citizens. The second is activating social norms. The third is framing, adding a message that makes subscribers care for future generations. Lastly, there is the recognition of saving efforts through a reward system
Extracting Dense and Connected Subgraphs in Dual Networks by Network Alignment
The use of network based approaches to model and analyse large datasets is
currently a growing research field. For instance in biology and medicine,
networks are used to model interactions among biological molecules as well as
relations among patients. Similarly, data coming from social networks can be
trivially modelled by using graphs. More recently, the use of dual networks
gained the attention of researchers. A dual network model uses a pair of graphs
to model a scenario in which one of the two graphs is usually unweighted (a
network representing physical associations among nodes) while the other one is
edge-weighted (a network representing conceptual associations among nodes). In
this paper we focus on the problem of finding the Densest Connected sub-graph
(DCS) having the largest density in the conceptual network which is also
connected in the physical network. The problem is relevant but also
computationally hard, therefore the need for introducing of novel algorithms
arises. We formalise the problem and then we map DCS into a graph alignment
problem. Then we propose a possible solution. A set of experiments is also
presented to support our approach
PMSR - Poor Man's Segment Routing, a minimalistic approach to Segment Routing and a Traffic Engineering use case
The current specification of the Segment Routing (SR) architecture requires
enhancements to the intra-domain routing protocols (e.g. OSPF and IS-IS) so
that the nodes can advertise the Segment Identifiers (SIDs). We propose a
simpler solution called PMSR (Poor Man's Segment Routing), that does not
require any enhancement to routing protocol. We compare the procedures of PMSR
with traditional SR, showing that PMSR can reduce the operation and management
complexity. We analyze the set of use cases in the current SR drafts and we
claim that PMSR can support the large majority of them. Thanks to the drastic
simplification of the Control Plane, we have been able to develop an Open
Source prototype of PMSR. In the second part of the paper, we consider a
Traffic Engineering use case, starting from a traditional flow assignment
optimization problem which allocates hop-by-hop paths to flows. We propose a SR
path assignment algorithm and prove that it is optimal with respect to the
number of segments allocated to a flow.Comment: September 2015 - Paper accepted to the Mini-conference track of NOMS
201
Electrofluorochromism in Ï-conjugated ionic liquid crystals
Materials in which photoluminescence is modulated by redox processes are known as electrofluorochromic. Intrinsically switchable fluorophores, incorporating both redox and fluorescent moieties, could be ideal electrofluorochromic materials if they possess high fluorescence quantum yields in at least one of their redox states. Fluorescent liquid crystals with redox active centres could combine the above requirements with the advantage to work in bulk anisotropic phases. However, electrofluorochromic liquid crystals have not been reported yet because their synthesis is challenging due to aggregation-caused fluorescent quenching. Here we show the first examples of electrofluorochromic Ï-conjugated ionic liquid crystals based on thienoviologens. These ordered materials, combining ionic and electronic functions, are highly fluorescence in the bulk state (quantum yield>60%). Their direct electrochemical reduction leads to fast and reversible bulk electrofluorochromic response in both columnar and smectic phases allowing for fluorescence intensity modulation and colour tuning
vocal signal analysis in patients affected by multiple sclerosis
Abstract Multiple Sclerosis (MS) is one of the most common neurodegenerative disorder that presents specific manifestations among which the impaired speech (known also as dysarthria). The evaluation of the speech plays a crucial role in the diagnosis and follow-up since the identification of anomalous patterns in vocal signal may represent a valid support to physician in diagnosis and monitoring of these neurological diseases. In this contribution, we present a method to perform voice analysis of neurologically impaired patients affected by MS aiming to early detection, differential diagnosis, and monitoring of disease progression. This method integrates two well-known methodologies to support the health structure in MS diagnosis in clinical practice. Acoustic analysis and vowel metric methodologies have been considered to implement this procedure to better define the pathological voices compared to healthy voices. Specifically, the method acquires and analyzes vocal signals performing features extraction and identifying possible important patterns useful to associate impaired speech with this neurological disease. The contribution consists in furnishing to physician a guide method to support MS trend. As result, this method furnishes patterns that could be valid indicators for physician in monitoring of patients affected by MS. Moreover, the procedure is appropriate to be used in early diagnosis that is critical in order to improve the patient's quality of life
Applying Mining Techniques to Analyze Vestibular Data
AbstractThe vestibular apparatus allows to perform audiological and equilibrium human functions and to capture movements with respect to gravity. Damages to the vestibular system causes diseases that can be measured by using Vestibular Evoked Myogenic Potentials (VEMPs) test. The test produces a lot of data that has to be collected and analyzed to allow a disease study and classification. We propose a framework that includes algorithms able to perform pathology distribution and classification. It has been tested on electronic patient records loaded from the University Hospital database. The software allows to manage the structure and framework and a blind application of one of the available classification techniques shows a relation among gender and vestibular apparatus disease
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