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Evaluation of Social Bot Detection Models
No full textSocial bots are employed to automatically perform online social network activities; thereby, they can also be utilized in spreading misinformation and malware. Therefore, many researchers have focused on the automatic detection of social bots to reduce their negative impact on society. However, it is challenging to evaluate and compare existing studies due to difficulties and limitations in sharing datasets and models. In this study, we conduct a comparative study and evaluate four different bot detection systems in various settings using 20 different public datasets. We show that high-quality datasets covering various social bots are critical for a reliable evaluation of bot detection methods. In addition, our experiments suggest that Botometer is preferable to others in order to detect social bots.Scientific and Technological Research Council of Turkey (TUBITAK) [ARDEB 3501, 120E514]This study was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) ARDEB 3501 Grant No 120E514. The statements made herein are solely the responsibility of the authors
Location-Privacy Preserving Partial Nearby Friends Querying in Urban Areas
No full textThis work studies the location-privacy preserving proximity querying in the context of proximity based services (PBSs), a special kind of location-based services (LBSs). The users register with the trusted PBS provider and specify their own personalized location privacy profile to be enforced against the curious friends (other registered users). Due to the urban area constraint, the user mobility is only on the city road network which is modeled as a weighted directed graph. The users share their own precise locations with the PBS provider and also query the nearby friends, the metric of which is defined on the shortest path on the graph. The proposed location privacy model ensures the location anonymity of the friends on the graph. To this end, two anonymity models, called weak location k-anonymity and strong location k-anonymity, are introduced to protect against the identified consecutive attack scenarios. The attack scenarios model the belief of the attacker (the query issuer) on the whereabouts of the friends. The PBS provider simulates the belief of each attacker on every users' whereabouts and suppresses some friends from the query result to ensure the location anonymity of each and every user at all times. Effective and efficient algorithms, needing no cryptographic protocols, have been developed to provide weak/strong location k-anonymity. An extensive experimental evaluation, mainly addressing the issues of privacy/utility tradeoff and runtime efficiency, on two real graphs with a simulated mobility is presented.TUBITAK [118E712]Acknowledgment This work has been supported by TUBITAK under the grant number 118E712
Assessment of Corneal Endothelial Cell Morphology and Anterior Segment Parameters in Covid-19
No full textBackground: The ocular manifestations of the 2019 novel coronavirus disease (COVID-19) vary from acute follicular, pseudomembranous, and hemorrhagic conjunctivitis to keratoconjunctivitis with subepithelial infiltrates and dendritic lesions. Similar to other respiratory viruses, such as adenoviruses, it is thought that COVID-19 may impact the cornea. However, its impact on the cornea and anterior segment parameters are currently poorly understood. Objective: This study aims to assess the corneal endothelial cell morphology and anterior segment parameters in patients who have recovered from COVID-19. Methods: In this cross-sectional study, the COVID-19 group comprised 34 patients who had been diagnosed with and recovered from COVID-19, while the control group comprised age- and sex-matched individuals without any systemic or ocular diseases. The endothelial cell density (ECD), coefficient of variation (CV) of cell area, hexagonal cell percentage (HEX), anterior chamber depth (ACD), central corneal thickness (CCT), horizontal anterior chamber diameter (HACD), iridocorneal angle (ICA), horizontal visible iris diameter (HVID), pupillary diameter (PD), and keratometry values (K1 and K2) were analyzed for each participant. The differences in each of these between the groups were analyzed using either an independent samples t test or a Mann-Whitney U test based on the normality of the data. Results: Regarding corneal endothelial cell morphology, the ECDs for the COVID-19 and control groups were 2278.50 +/- 186.78 cells/mm(2) and 2420.15 +/- 222.25 cells/mm(2), respectively (p = 0.002). A significant increase was noted in CV values in the COVID-19 group compared with the control group (p 0.001). The HEX values for the COVID-19 and control groups were 56.26 +/- 5.75 and 61.50 +/- 3.63, respectively (p 0.001). Regarding the anterior segment parameters, no significant differences were observed between the groups (p> 0.05). Conclusions: It was hypothesized that individuals who had recovered from COVID-19 would demonstrate a reduction in their endothelial functional preserves. A decrease in ECD and HEX and an increase in CV were observed in the individuals during their early post-recovery period from COVID-19
Procurement Policy and Sme Participation in Public Purchasing
No full textThis study investigates the relationship between regulatory policies governing public procurement and participation by small and medium enterprises (SMEs), using a large dataset on European procurement. We find that better quality procurement regulation is associated with greater SME participation and higher probability that SMEs win contracts. Dividing contracts into smaller lots, a key feature of 2014 EU procurement regulation reform, bolsters participation by SMEs but only increases the probability of SMEs winning contracts for small value lots (euro25,000 or less). Our results suggest governments seeking to enhance participation by SMEs in public procurement without explicitly favoring SMEs can do so by improving the overall quality of procurement processes.European University Institute - Fiesole within the CRUI-CARE AgreementOpen access funding provided by European University Institute - Fiesole within the CRUI-CARE Agreement
Both Directions at Once : John Coltrane, the Sonic Philosopher of Oppositions
No full textIn Both Directions at Once, an album lost for almost 40 years, John Coltrane presents a constellation of musical tradition, themes, composition and improvisation, in dialecti- cal opposition. This article imagines Coltrane as a sonic philosopher of oppositions and the album-named after Coltrane's quote in which he attempts 'starting a sentence in the middle, and then going to the beginning and the end of it at the same time... both directions at once'-as his philosophical treatise. Borrowing from biographers, musi- cologists and jazz critics, this contribution argues that in the album, the music engages with itself rather than seeking resolution or finality. In other words, Coltrane's dialecti- cal aesthetic drives the aesthetic. Both Directions at Once is sound focused on soni-cally opposing forces. It is an attempt by a deep thinker to present contradictions and oppositions between musical polarities that may create new potentialities. What listen- ers hear is Coltrane, the philosopher, striving toward a multidirectional aesthetic that furnishes music unshackled from the conditions of possibility
Measurements of Azimuthal Anisotropies of Jet Production in Pb Collisions at Root(nn)-N Tev With the Atlas Detector
No full textThe azimuthal variation of jet yields in heavy-ion collisions provides information about the path-length dependence of the energy loss experienced by partons passing through the hot, dense nuclear matter known as the quark-gluon plasma. This paper presents the azimuthal anisotropy coefficients v(2), v(3), and v(4) measured for jets in Pb + Pb collisions at root(NN)-N-s =5.02 TeV using the ATLAS detector at the LHC. The measurement uses data collected in 2015 and 2018, corresponding to an integrated luminosity of 2.2 nb(-1). The v(n) values are measured as a function of the transverse momentum of the jets between 71 and 398 GeV and the event centrality. A nonzero value of v(2) is observed in all but the most central collisions. The value of v(2) is largest for jets with lower transverse momentum, with values up to 0.05 in mid-central collisions. A smaller, nonzero value of v(3) of approximately 0.01 is measured with no significant dependence on jet p(T) or centrality, suggesting that fluctuations in the initial state play a small but distinct role in jet energy loss. No significant deviation of v(4) from zero is observed in the measured kinematic region.ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW, Austria; FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, Brazil; FAPESP, Brazil; NSERC, Canada; NRC, Canada; CFI, Canada; CERN; ANID, Chile; CAS, China; MOST, China; NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF, Denmark; DNSRC, Denmark; IN2P3-CNRS , France; CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, Germany; HGF, Germany; MPG, Germany; GSRI, Greece; RGC, China; Hong Kong SAR, China; ISF, Israel; Benoziyo Center, Israel; INFN, Italy; MEXT, Japan; JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia, Russian Federation; NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS, Slovenia; MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, Switzerland; Canton of Bern, Switzerland; Canton of Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE, USA; NSF, USA; BCKDF, Canada; CANARIE, Canada; Compute Canada, Canada; CRC, Canada; COST, European Union; ERC, European Union; ERDF, European Union; Horizon 2020, European Union; Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex, France; Investissements d'Avenir Idex, France; ANR, France; DFG, Germany; AvH Foundation, Germany; Herakleitos programme - EU-ESF, Greece; Thales programme - EU-ESF, Greece; Aristeia programme - EU-ESF, Greece; Greek NSRF, Greece; BSF-NSF, Israel; GIF, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN, Poland; NAWA, Poland; La Caixa Banking Foundation, Spain; CERCA Programme Generalitat de Catalunya, Spain; PROMETEO Programme Generalitat Valenciana, Spain; GenT Programme Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; Royal Society, United Kingdom; Leverhulme Trust, United KingdomWe thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRI, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia and NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, USA. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; COST, ERC, ERDF, Horizon 2020 and Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and GIF, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN and NAWA, Poland; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref. [49]
Effect of End-To Delay on Lifetime and Average Bit Error Rate in Directional Antenna Based Wireless Sensor Networks
No full text2022 International Balkan Conference on Communications and Networking, BalkanCom 2022 -- 22 August 2022 through 24 August 2022 -- 183326This paper evaluates the effect of end-to-end delay on lifetime and the average bit error rate for wireless sensor networks where each sensor node sends its data to sink via directional antennas. Using Mixed Integer Programming, lifetime is optimized for circular network topologies with different numbers of nodes. Using both directional and omnidirectional antennas, different end-to-end delay restrictions are applied to the same sensor network to examine the effect on lifetime and average bit error rate. When delay restriction is relaxed, an increase in lifetime and a decrease in average bit error rate are observed for both antennas. In this case, the directional antenna benefits more from relaxing the delay restriction. In the end, an optimal end-to-end delay was determined which provides sufficient lifetime and bit error rate while taking into account data freshness. © 2022 IEEE
Direct Constraint on the Higgs-Charm Coupling From a Search for Higgs Boson Decays Into Charm Quarks With the Atlas Detector
No full textA search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton- proton collisions to target the production of a Higgs boson in association with a leptonically decaying W or Z boson. The dataset delivered by the LHC at a centre-of-mass energy of root s = 13 TeV and recorded by the ATLAS detector corresponds to an integrated luminosity of 139 fb(-1). Flavour-tagging algorithms are used to identify jets originating from the hadronisation of charm quarks. The analysis method is validated with the simultaneous measurement of WW, WZ and ZZ production, with observed (expected) significances of 2.6 (2.2) standard deviations above the background-only prediction for the (W/Z)Z(-> c (c) over bar) process and 3.8 (4.6) standard deviations for the (W/Z)W(-> cq) process. The (WIZ)H(-> c (c) over bar) search yields an observed (expected) upper limit of 26 (31) times the predicted Standard Model crosssection times branching fraction for a Higgs boson with a mass of 125 GeV, corresponding to an observed (expected) constraint on the charm Yukawa coupling modifier vertical bar k(c)vertical bar 8.5 (12.4), at the 95% confidence level. A combination with the ATLAS (W/Z)H, H -> b(b)over bar> analysis is performed, allowing the ratio k(c)/k(b) to be constrained to less than 4.5 at the 95% confidence level, smaller than the ratio of the b- and c-quark masses, and therefore determines the Higgs-charm coupling to be weaker than the Higgs-bottom coupling at the 95% confidence level.ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, Brazil; FAPESP, Brazil; NSERC, Canada; NRC, Canada; CFI, Canada; CERN; ANID, Chile; CAS, China; MOST, China; NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF, Denmark; DNSRC, Denmark; IN2P3CNRS, France; CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, Germany; HGF, Germany; MPG, Germany; GSRI, Greece; RGC, China; Hong Kong SAR, China; ISF, Israel; Benoziyo Center, Israel; INFN, Italy; MEXT, Japan; JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia; NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS, Slovenia; MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, Switzerland; Canton of Bern,Switzerland; Canton of Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE, USA; NSF, USA; BCKDF, Canada; CANARIE, Canada; Compute Canada, Canada; CRC, Canada; COST; ERC; ERDF; Horizon 2020 and Marie Sklodowska Curie Actions, European Union; Investissements d'Avenir Labex,France; Investissements d'Avenir Idex, France; ANR, France; DFG, Germany; AvH Foundation, Germany; EU ESF; Greek NSRF, Greece; BSF-NSF, Israel; GIF,Israel; Norwegian Financial Mechanism 2014-2021,Norway; NCN, Poland; NAWA, Poland; La Caixa Banking Foundation, Spain; CERCA Programme Generalitat de Catalunya, Spain; PROMETEO Programme Generalitat Valenciana, Spain; GenT Programme Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; Leverhulme Trust, UK; BMWFW, Austria; Royal Society; Herakleitos programme; Thales programme; Aristeia programmeWe thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRI, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia and NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, USA. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; COST, ERC, ERDF, Horizon 2020 and Marie Sklodowska Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU ESF and the Greek NSRF, Greece; BSF-NSF and GIF, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN and NAWA, Poland; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, UK. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref. [120]
Rereading Turkey's Recent History Through the Lens of Rock Music: How Rock Has Lost Its Socio-Political Edge in Neoliberal Times
No full textIn presenting the historical development of rock music in Turkey from the early 1960s to the present within a socio-political framework, this study provides (1) a rereading of Turkish politico-economic changes and (2) a correlative cultural critique of rock musicianship and songwriting in the neoliberal age. Two related hypotheses are tested through a content analysis of 67 rock acts, 426 releases and 3452 songs from 1963 to 2019. First, it is argued that as Turkey moved from import substitution industrialisation between 1960 and 1980 to 1980s neoliberalism, the content of rock music lyrics changed from being overtly socio-political to having no relation to such matters or to adopting implicit and indirect language in mentioning them. Second, it is proposed that this lyrical unresponsiveness to social matters grew so powerfully as part of the neoliberal economic rationale that it put individuation, self-realisation and market demands ahead of other forms of social relations. So, today's rock artists are unequipped to respond through their lyrics to grand events, such as the Gezi Park protests of 2013, the failed coup attempt of 2016, or a two-year state of emergency, terrorism and femicide, in contrast to the rock music of the 1960s and 1970s
