1,720,955 research outputs found
Queuing Delay Analysis for Packet-Switched Networks with FIFO Service Discipline
Get PDFU radu je prikazana analiza čekanja paketa u čvorovima paketne mreže sa disciplinom
posluživanja FIFO (First in First out). Opisani su i analizirani svi razlozi zbog kojih se paketi
zadržavaju u čvoru. Postoje četiri izvora kašnjenja, a to su: procesiranje u čvoru, čekanje na
prijenos, propagacija i prijenos. Načinjena je numerička analiza utjecaja pojedinih parametara,
kao što su prometno opterećenje, duljina paketa i distribucija duljine paketa te broj
poslužitelja, na čekanje u čvoru paketne mreže.The paper describes the waiting packets in a packet-switch network with FIFO (First
In First Out) servise discipline. Also, described and analyzed all the reasons why the packages
remain in the node. Presents a numerical analysis of the impact of certain parameters, such as
traffic load, packet length distribution and packet length and the number of servers, on hold in
node packet network
Reinforced Learning based Variable Speed Limit Control for Traffic Flows with Connected Autonomous Vehicles
No full textDanašnje autoceste dizajnirane su za pružanje većeg maksimalnog prometnog kapaciteta, ali se javlja sve veći problem premalog kapaciteta istih. Međutim, gradske autoceste se najčešće ne mogu širiti, stoga je potrebno tražiti druga rješenja kako bolje iskoristiti njihov raspoloživ kapacitet. Jedan od sustava iz domene inteligentnih transportnih sustava, koji se može iskoristiti u tu svrhu, je sustav za upravljanje promjenjivim ograničenjem brzine (eng. Variable Speed Limit Control - VSLC). Autonomna vozila (eng. Autonomous vehicle - AV) i umrežena autonomna vozila (eng. Connected Autonomous Vehicles – CAV) uvelike se testiraju i brzo razvijaju u posljednjih nekoliko godina. Da bi se ispitali potencijalni učinci mješoviti tokovi prometa moraju se simulirati u različitim prometnim scenarijima. U ovom diplomskom radu napravljen je QL-DVSL (eng. Q-Learning – Dual Variable Speed Limit – QL-DVSL) sustav koji postavlja ograničenja brzine na svaku prometnu traku zasebno u simulacijskom okruženju u cestovnom mikroskopskom simulacijskom programu SUMO (eng. Simulation of Urban MObility) i programskom okruženju Python. Dobiveni rezultati dokazuju da povećanje udjela autonomnih vozila u prometnom toku djeluje pozitivno, odnosno vožnja se odvija sinkroniziranije, promet se odvija jednolikom brzinom, vrijeme putovanja se smanjuje, postignuta je veća brzina u prometnom toku i smanjena je gustoća vozila čime se smanjuju repovi čekanja.Today's motorways are designed to provide a higher maximum traffic capacity, but the problem of insufficient capacity is increasing. However, urban motorways cannot be widened most of the time, thus, it is necessary to look for other solutions to make better use of the existing capacity of urban motorways. One of the systems from the domain of intelligent transportation systems, which can be used for this, is Variable Speed Limit Control (VSLC). Autonomous vehicles (AV) and connected autonomous vehicles (CAV) have been extensively tested and developed rapidly in the last few years. To examine the characteristics of mixed traffic flows, they must be simulated in different traffic scenarios. In this thesis, a QL-DVSL (Q-Learning – Dual Variable Speed Limit) system that sets separate speed limits on each lane in a simulation environment was created in the road microscopic simulation program SUMO (Simulation of Urban MObility) and the Python programming environment. The obtained results prove that the increase in the share of AV in the traffic flow has a positive effect, i.e., driving is more synchronized, traffic proceeds at a uniform speed, driving time is reduced, and a higher speed has been achieved in the traffic flow, the density of vehicles is reduced, which reduces waiting in queues
Impact of UAVs in Traffic Incident Management
Get PDFBespilotna letjelica je letjelica ili zrakoplov bez posade. Ona se može nadzirati na daljinu ili letjeti samostalno. Bespilotna letjelica samostalno može letjeti uporabom unaprijed programiranog plana leta ili pomoću složenih autonomnih dinamičkih sustava. Razvoj bespilotnih letjelica započela je ponajprije vojska u svrhu smanjivanja troškova i ljudskih žrtava. Dovoljno govori činjenica da troškovi održavanja i izrade jedne bespilotne letjelice čine desetinu troškova jednog suvremenog zrakoplova. Najveći izazov kod modeliranja je dakako navigacija i pozicioniranje bespilotnih letjelica, bilo da se radi o vojnoj ili civilnoj uporabi. Danas se najčešće integriraju dva senzora: INS (inercijalni navigacijski sustav) i GNSS (globalni navigacijski satelitski sustav). Prateći povijesni razvoj sve do današnjih dana pokazano je koliki je napredak postignut u tom smjeru. U današnje vrijeme došlo je do povećanja broja i vrsta senzora koje bespilotne letjelice mogu sadržavati, a samim time i do širenja njihove uporabe.Unmanned aircraft vehicle (UAV) is an aircraft without crew. It can be controlled remotely or fly autonomously. UAV can fly using pre-programmed flight plan or using complex autonomous dynamical systems. UAV development was initiated by the military in order to reduce costs and human casualties. Just the fact that the costs of maintenance and making one UAV consists of one tenth of a modern aircraft says enough.The biggest challenge in modeling UAV is the course navigation and positioning unmanned aerial vehicles, weather it is military or civilian use. Today the most often integration is the one of two sensors: INS (inertial navigation system) and GNSS (global navigation sattelite system). Following the historical development up to the present it has been shown how much progress has been made in this direction. At the present time there has been an increase in the number and types of sensors that UAV may contain, and therefore to spread their use
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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