1,107 research outputs found
Intra-Domain Pathlet Routing
Internal routing inside an ISP network is the foundation for lots of services
that generate revenue from the ISP's customers. A fine-grained control of paths
taken by network traffic once it enters the ISP's network is therefore a
crucial means to achieve a top-quality offer and, equally important, to enforce
SLAs. Many widespread network technologies and approaches (most notably, MPLS)
offer limited (e.g., with RSVP-TE), tricky (e.g., with OSPF metrics), or no
control on internal routing paths. On the other hand, recent advances in the
research community are a good starting point to address this shortcoming, but
miss elements that would enable their applicability in an ISP's network.
We extend pathlet routing by introducing a new control plane for internal
routing that has the following qualities: it is designed to operate in the
internal network of an ISP; it enables fine-grained management of network paths
with suitable configuration primitives; it is scalable because routing changes
are only propagated to the network portion that is affected by the changes; it
supports independent configuration of specific network portions without the
need to know the configuration of the whole network; it is robust thanks to the
adoption of multipath routing; it supports the enforcement of QoS levels; it is
independent of the specific data plane used in the ISP's network; it can be
incrementally deployed and it can nicely coexist with other control planes.
Besides formally introducing the algorithms and messages of our control plane,
we propose an experimental validation in the simulation framework OMNeT++ that
we use to assess the effectiveness and scalability of our approach.Comment: 13 figures, 1 tabl
Prelude: Ensuring Inter-Domain Loop-Freedom in~SDN-Enabled Networks
Software-Defined-eXchanges (SDXes) promise to tackle the timely quest of
bringing improving the inter-domain routing ecosystem through SDN deployment.
Yet, the naive deployment of SDN on the Internet raises concerns about the
correctness of the inter-domain data-plane. By allowing operators to deflect
traffic from the default BGP route, SDN policies are susceptible of creating
permanent forwarding loops invisible to the control-plane.
In this paper, we propose a system, called Prelude, for detecting SDN-induced
forwarding loops between SDXes with high accuracy without leaking the private
routing information of network operators. To achieve this, we leverage Secure
Multi-Party Computation (SMPC) techniques to build a novel and general
privacy-preserving primitive that detects whether any subset of SDN rules might
affect the same portion of traffic without learning anything about those rules.
We then leverage that primitive as the main building block of a distributed
system tailored to detect forwarding loops among any set of SDXes. We leverage
the particular nature of SDXes to further improve the efficiency of our SMPC
solution.
The number of valid SDN rules, i.e., not creating loops, rejected by our
solution is 100x lower than previous privacy-preserving solutions, and also
provides better privacy guarantees. Furthermore, our solution naturally
provides network operators with some hindsight on the cost of the deflected
paths
INCREASING THE VALUE OF THE TYPICAL WINE PRODUCTION IN NATIONAL TERRITORY: A PILOT PROJECT IN THE PROVINCE OF BERGAMO
Le caratteristiche di un vino dipendono dalla cantina, dai vitigni utilizzati per la produzione delle uve, e
dal terroir: quella combinazione magica di geologia, morfologia, clima, coltura e cultura che caratterizza
l’ambiente dove il vino nasce. Un sistema informativo geografi co è uno strumento potentissimo al servizio
della qualificazione del terroir perché aiuta gli esperti nell’elaborazione dei dati e nella loro analisi.
La tecnologia WebGIS si rivela essere un valido strumento di ausilio per l’analisi e la valorizzazione
del territorio. Attraverso l’uso di queste soluzioni tecnologicamente avanzate, WineGIS fornisce in maniera
integrata strumenti di carattere tecnico e scientifico, in grado di rappresentare in modo unitario la
complessa e ricca realtĂ delle zone di produzione tipiche dei vini italiani. E di rappresentare un punto di
partenza per una moderna politica di valorizzazione del territorio.The characteristics of a wine depend on the cellar, the grapevines used in the production of the
grapes and the terroir: that magical combination of geology, landscape, climate culture that characterize
the environment in which the wine is born. GIS is a powerful instrument in providing accurate
terroir information because it helps experts in the elaboration of data and their research.
Web GIS technology is a powerful tool to support landscape analysis and promotion. Through the
use of these technologically advanced solutions, WineGIS offers, in an integrated manner, scientific
and technical instruments able to represent in a unified way, a complex and rich view of areas of
production typical to the Italian wine industry. And to represent a starting point for a modern political
evaluation of the zone
Design of a blow off valve for turbocharged engine applications
On a turbo engine, the Blow of Valve (BOV) is used to relieve the pressure from the turbo output when the throttle is closed. Without the BO y, when the throttle
is closed the turbo is suddenly trying to pump air against a closed throttle plate. This creates pressure spike in the turbo output hose and will send back the pressure to the turbine and can damage the turbo engine. When the throttle is opened again, the turbo has to spin up again, creating turbo lag. So, the present of the BOY will opened when the throttle is closed and pressurized the pressure spike to the air to avoid those phenomena. So, good flow of the air inside the BOV is important, the air will smoothly pressurized to the atmosphere if there is no back pressure inside the system. Computer aided design (CAD) and computational fluid dynamic (CFD)
software were used as a tool for the design. This design is the improvement of the aftermarket design. The piston surface, size of vent, inlet ports, outlet ports, and also spring plays the role in the BOy. The design analyzed using CFD so can see the flow trajectories of the air inside the BOy
The CPV “toolbox”: New approaches to maximizing solar resource utilization with application-oriented concentrator photovoltaics
As the scaling of silicon PV cells and module manufacturing has driven solar energy
penetration up and costs down, concentrator photovoltaic technologies, originally conceived as a
cost-saving measure, have largely been left behind. The loss of market share by CPV is being locked in
even as solar energy development encounters significant obstacles related to space constraints in many
parts of the world. The inherently higher collection efficiency enabled by the use of concentrators
could substantially alleviate these challenges, but the revival of CPV for this purpose requires
substantial reinvention of the technology to actually capture the theoretically possible efficiency gains,
and to do so at market-friendly costs. This article will discuss recent progress in key areas central
to this reinvention, including miniaturization of cells and optics to produce compact, lightweight
“micro-CPV” systems; hybridization of CPV with thermal, illumination and other applications to
make use of unused energy streams such as diffuse light and waste heat; and the integration of
sun-tracking into the CPV module architecture to enable greater light collection and more flexible
deployment, including integration into built structures. Applications showing particular promise
include thermal applications such as water heating, industrial processes and desalination; agricultural
photovoltaics; building-integrated photovoltaics with dynamic daylighting capabilities; and chemical
processes including photocatalysis and hydrogen production. By appropriately tailoring systems
to the available solar resource and local energy demand, we demonstrate how CPV can finally
achieve real-world efficiencies, or solar resource utilization factors, far higher than those of standard
silicon-based PV systems. This makes the argument for sustained development of novel CPV designs
that can be applied to the real-world settings where this efficiency boost will be most beneficial
Comparative cytotoxicity evaluation of eight root canal sealers
The aim of the present study is to evaluate and compare the cytotoxic effects of eight root canal sealers (BioRoot RCS, TotalFill BC Sealer, MTA Fillapex, Sealapex, AH Plus, EasySeal, Pulp Canal Sealer, N2) on immortalized human gingival fibroblasts over a period of 24, 48 and 72 hours. Immortalized human gingival fibroblast-1 HGF-1 (ATCC CRL-2014) were incubated. Root canal sealers were then placed into sterile, cylindrical Teflon moulds. The extraction was made eluting the sealers in cell culture medium. Cells (1 × 104) were seeded in each well of a 96-well plate and incubated for 24 h at 37°C. Cultures were then exposed to 100 ?L of the extracts medium. The percentage of viable cells in each well was calculated relative to control cells set to 100%. BioRoot RCS and TotalFill BC Sealer extracted for 24h showed no cytotoxic effect, while it was mild by using 48 and 72 h extracts. No cytotoxic effect was measured by using AH Plus medium eluted for 24 h, while it was moderate after 48 h and severe after 72 h. Pulp Canal Sealer, Sealapex and N2 showed moderately cytotoxic activity for all the extraction times. EasySeal and MTA Fillapex remained severely or borderline mildly cytotoxic for all the extraction times. In the present study only BioRoot RCS, TotalFill BC Sealer and AH Plus showed no cytotoxic effects at least in the first 24h. All the other sealers revealed moderately or severely cytotoxic activity during all the extraction times
Microleakage in Class II composite restorations with margins below the CEJ: in vitro evaluation of different restorative techniques
Objectives: The purpose of this in vitro study was to evaluate the microleakage in "deep" Class II composite restorations
with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques.
Study Design: Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and
on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was
located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable
(3MESPE) + Universal Filtek Supreme XTE (3MESPE), Group 2: GrandioSO Heavy Flow (Voco) + GrandioSo
(Voco), Group 3: SDRTm (Dentsply Caulk) + Esthet-X® HD (Dentsply Caulk), Group 4: SonicFill (Kerr), Group
5: Grandio (Voco). After thermocycling, the specimens were immersed in a 0.5% basic fuchsine dye solution and
incubated at 37°C for 24 hours. The teeth were subsequently sectioned mesiodistally. All specimens were examined at 25× in a stereomicroscope and standardized digital images were obtained. Dye penetration was measured
from gingival margins.
Results: The results demonstrated no significant leakage differences between Group 4 and Group 5, that both
showed significantly higher frequency distribution of Score 0. Group 2 and Group 3 showed a significant prevalence of Score 1, whereas Group 1 showed significantly higher frequency of Score 2.
Conclusions: None of the restorative techniques tested completely eliminated microleakage dye penetration in
dentin margins; marginal adaptation in Class II composite restorations with gingival wall below the CEJ varied in
both substrates and from different restorative techniques used
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