Search results for "Real-Time"

showing 10 items of 881 documents

On Serving Cell Change Reliability in HSDPA Network

2009

In Wideband Code Division Multiple Access (WCDMA) networks the Signaling Radio Bearer (SRB) is transmitted downlink to inform the user i.a. when it needs to make a handover. When transmitting e.g. Voice over IP (VoIP) on High Speed Downlink Packet Access (HSDPA) SRB is mapped on HSDPA user data channel, High-Speed Downlink Shared Channel (HS-DSCH) in order to maximize voice capacity. The lack of support for soft handover (SHO) of HS-DSCH may compromise the reception of SRB and thus also a possible incoming serving HSDPA cell change command especially at the cell borders. This can lead to serious VoIP service degradation due to prolonged camping on a poor cell and in the worst case even to c…

Voice over IPbusiness.industryComputer scienceNetwork packetCode division multiple accessMacro cellReal-time computingHigh-Speed Downlink Packet AccessSoft handoverSpread spectrumHandoverW-CDMATelecommunications linkbusinessComputer network2009 IEEE Wireless Communications and Networking Conference
researchProduct

Analysis of RRM limitations and restricted transmission periods for VoIP over HSDPA

2009

This paper studies how the performance of Voice over IP (VoIP) over High Speed Downlink Packet Access (HS-DPA) networks is affected if transmission to a User Equipment (UE) is stopped for specific amount of time during handover procedure. This paper also addresses the situation when it might be necessary to limit the number of UEs in a cell. The study showed that parameter settings for Radio Resource Management (RRM) algorithms can have an effect to the VoIP capacity: If handover lasts long enough for VoIP packets to be lost, or severe congestion occurs in a cell, VoIP capacity may be degraded.

Voice over IPbusiness.industryNetwork packetComputer scienceComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSReal-time computingMobile communications over IPTransmission (telecommunications)User equipmentHandoverTelecommunications linkRadio resource managementbusinessComputer networkAsian Internet Engineering Conference on - AINTEC '09
researchProduct

Analysis of VoIP over HSDPA Performance with Discontinuous Reception Cycles

2009

The aim of this paper is to evaluate how Discontinuous Reception (DRX) cycles and related timers take effect to Voice over IP (VoIP) performance when High Speed Downlink Packet Access (HSDPA) networks are in question. DRX cycles limit the scheduling freedom of users and increase battery saving opportunities in the User Equipment (UE) by allowing it to turn its receiver circuitry off for some periods of time. Prior work has concentrated mainly on optimizing the usage of radio resources when small bit rate delay critical services, like VoIP, are considered. However, the battery life of small handheld devices might become a limiting factor in providing satisfactory user experience. Thus, this …

Voice over IPbusiness.industryNetwork packetComputer scienceQuality of serviceComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSReal-time computingScheduling (computing)User equipmentDiscontinuous receptionTimerRadio resource managementbusinessComputer network2009 Sixth International Conference on Information Technology: New Generations
researchProduct

UVolc: A software platform for measuring volcanic SO2 fluxes

2012

We present here a novel stand-alone software platform, UVolc, for remotely sensed measurement of volcanic SO"2 emission rates. Such data are important diagnostics of activity conditions, with utility in forecasting measures. This code is made user friendly to enable volcanologists, who are not experts in the underlying physics of spectroscopy, to perform their own measurements. The program provides considerable reduction in errors and far greater operating flexibility than existing analogous code, which, unlike UVolc, can only interface with hardware no longer in manufacture. UVolc will be described here, including a presentation of data collected with this program in the field.

Volcanic SO2 monitoring Volcanic gas geochemistry Volcano remote sensingFlexibility (engineering)geographyUser Friendlygeography.geographical_feature_categorybusiness.industryInterface (computing)Real-time computingField (computer science)Settore GEO/08 - Geochimica E VulcanologiaSoftwareVolcanoCode (cryptography)Computers in Earth SciencesbusinessReduction (mathematics)GeologyInformation SystemsRemote sensingComputers & Geosciences
researchProduct

Anti-inflammatory Function of High-Density Lipoproteins via Autophagy of IκB Kinase

2015

Background & Aims: Plasma levels of high-density lipoprotein (HDL) cholesterol are frequently found decreased in patients with inflammatory bowel disease (IBD). Therefore, and because HDL exerts anti-inflammatory activities, we investigated whether HDL and its major protein component apolipoprotein A-I (apoA-I) modulate mucosal inflammatory responses in vitro and in vivo. Methods: The human intestinal epithelial cell line T84 was used as the in vitro model for measuring the effects of HDL on the expression and secretion of tumor necrosis factor (TNF), interleukin-8 (IL-8), and intracellular adhesion molecule (ICAM). Nuclear factor-κB (NF-κB)-responsive promoter activity was studied by …

WT wild typeApolipoprotein BEMSA electrophoretic mobility shift assayMPO myeloperoxidaseIκB kinaseDSS dextran sodium sulphatemTOR the mammalian target of rapamycinRT-PCR real-time polymerase chain reactionNF-κBchemistry.chemical_compound540 ChemistryApoA-I apolipoprotein A-I10038 Institute of Clinical ChemistryOriginal ResearchTNF tumor necrosis factorbiologyIBD inflammatory bowel diseaseChemistryGastroenterologyMyeloperoxidase10076 Center for Integrative Human PhysiologyMEICS murine endoscopic index of colitis severityTumor necrosis factor alphalipids (amino acids peptides and proteins)3-MA 3-methyl adenineNF-κB nuclear factor κBHDL high-density lipoproteinLC3II light chain 3 IIPBS phosphate-buffered salinep-IKK phosphorylated IκB kinase610 Medicine & healthICAM intracellular adhesion molecule246-Trinitrobenzenesulfonic acidTg transgenicmedicineAutophagyCD Crohn’s disease2715 GastroenterologyColitislcsh:RC799-869KO knockoutHepatologyApolipoprotein A-IAutophagyInflammatory Bowel DiseaseTNBS 246-trinitrobenzenesulfonic acidmedicine.diseaseMolecular biologyIL interleukinsiRNA small interfering RNAPI-3 phosphatidylinositol-3Immunologybiology.protein2721 Hepatologylcsh:Diseases of the digestive system. GastroenterologyPFA paraformaldehydeLipoproteinDAPI 4′6-diamidino-2-phenylindoleCMGH Cellular and Molecular Gastroenterology and Hepatology
researchProduct

Coverage analysis of RFID indoor localization system for refrigerated warehouses based on 2D-ray tracing

2012

Warehouse managementComputer sciencebusiness.industryReal-time computingIndustrial and Manufacturing EngineeringManagement Information SystemsWarehouseCoverage analysis; RFID; localization system; 2D-ray tracingManagement of Technology and InnovationRay tracing (graphics)Coverage analysis RFID localization system 2D-ray tracingElectrical and Electronic EngineeringLocalization systemTelecommunicationsbusiness
researchProduct

Modeling a non-stationary bots’ arrival process at an e-commerce Web site

2017

Abstract The paper concerns the issue of modeling and generating a representative Web workload for Web server performance evaluation through simulation experiments. Web traffic analysis has been done from two decades, usually based on Web server log data. However, while the character of the overall Web traffic has been extensively studied and modeled, relatively few studies have been devoted to the analysis of Web traffic generated by Internet robots (Web bots). Moreover, the overwhelming majority of studies concern the traffic on non e-commerce websites. In this paper we address the problem of modeling a realistic arrival process of bots’ requests on an e-commerce Web server. Based on real…

Web serverGeneral Computer ScienceComputer scienceInternet robotReal-time computing02 engineering and technologyE-commercecomputer.software_genreSession (web analytics)Theoretical Computer ScienceWeb traffic characterizationWeb serverWeb traffic0202 electrical engineering electronic engineering information engineeringTraffic generation modelWeb traffic analysis and modelingbusiness.industryComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS020206 networking & telecommunicationsWeb botHeavy-tailed distributionModeling and SimulationHeavy-tailed distribution020201 artificial intelligence & image processingThe InternetWeb log analysis softwareLog file analysisData miningbusinessRegression analysiscomputerJournal of Computational Science
researchProduct

Efficient on-the-fly Web bot detection

2021

Abstract A large fraction of traffic on present-day Web servers is generated by bots — intelligent agents able to traverse the Web and execute various advanced tasks. Since bots’ activity may raise concerns about server security and performance, many studies have investigated traffic features discriminating bots from human visitors and developed methods for automated traffic classification. Very few previous works, however, aim at identifying bots on-the-fly, trying to classify active sessions as early as possible. This paper proposes a novel method for binary classification of streams of Web server requests in order to label each active session as “bot” or “human”. A machine learning appro…

Web serverInformation Systems and ManagementComputer scienceInternet robot02 engineering and technologyMachine learningcomputer.software_genreUsage dataManagement Information SystemsIntelligent agentEarly decision; Internet robot; Machine learning; Neural network; Real-time bot detection; Sequential analysis; Web botArtificial IntelligenceReal-time bot detection020204 information systemsMachine learning0202 electrical engineering electronic engineering information engineeringFalse positive paradoxSequential analysisSession (computer science)business.industryWeb botNeural networkEarly decisionTraffic classificationBinary classification020201 artificial intelligence & image processingArtificial intelligencebusinesscomputerClassifier (UML)SoftwareKnowledge-Based Systems
researchProduct

Road traffic detection using wireless noise sensors

2012

In this paper we present our experimental result of using wireless noise sensor network (WNSN) to detect road traffic. With the features implemented in our network such as multipoint measuring, synchronization, real-time data availability, and strict compliance of sound level meter (SLM) standard IEC 61672:2003, we assert the possibility of using WNSN to detect road traffic, such as vehicle amount, size, and velocity. This application can be extended and integrated as a part of Intelligent Transportation System (ITS).

Wi-Fi arrayComputer sciencebusiness.industryWireless networkReal-time computingFloating car dataNoiseKey distribution in wireless sensor networksEmbedded systemWirelessSound level meterbusinessWireless sensor networkIntelligent transportation system2012 IEEE International Conference on Communications (ICC)
researchProduct

WIDAR: Bistatic WI-fi Detection And Ranging for off-the-shelf devices

2013

The huge spread of wireless networks and the success of location-aware applications require novel indoor po- sitioning mechanisms based on existing technologies such as IEEE 802.11. Taking inspiration from the RADAR, we propose WIDAR: a bistatic WI-fi Detection And Ranging system for off- the-shelf devices. WIDAR implementation is based on the USRP2 platform and is able to locate 802.11 stations while they operate in existing legacy networks. No substitution or repositioning of the Access Points is necessary. WIDAR works passively and does not expect any dedicated action from the target WiFi node. No airtime is wasted and the target cannot even detect that it is being ranged. Such features …

Wi-Fi arrayranging positioning passive radar wireless wifi 802.11Settore ING-INF/03 - TelecomunicazioniComputer sciencebusiness.industryWireless networkNode (networking)Real-time computingRanginglaw.inventionBistatic radarlawOff the shelfRadarSurveillance and monitoringbusinessComputer network2013 IEEE 14th International Symposium on "A World of Wireless, Mobile and Multimedia Networks" (WoWMoM)
researchProduct