5916 research outputs found
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Benchmark study of 2D and 3D VOF simulations of a simplex nozzle using a hybrid RANS-LES approach
No full textIn this study, a simplex nozzle is tested with water for the benchmarking of different flow simulation models. A large scale Plexi-glass transparent nozzle is used to reduce the influence of production tolerances on the performance. Experiments are conducted at different flow rates and CD, spray angle and film thickness parameters are evaluated. 2D and 3D hybrid RANS-LES multiphase flow simulations of simplex nozzle are validated against the experimental data. Multiphase nature of the flow is modelled by volume of fluid method. The main goal is to assess the capabilities and drawbacks of 2D axisymmetric and full sector 3D modeling approaches. It is observed that although full sector 3D simulations require HPC cluster systems, accuracies in validation parameters are quite satisfying. Conversely, 2D axisymmetric simulations which can be run on a single core and give a general outlook of the flow field, they show an overshoot of CD and film thickness over the selected range of flow rate. It is shown that this overshoot is mostly related with the inlet boundary condition, which can not take the flow contraction and/or separation at the inlet slots into account. After correcting the inlet velocity 2D simulations by using the 3D results, it is shown that the predictions can be quite close to the experimental data.Tusas Engine Industries ; TÜBİTAK ; Istanbul Teknik Üniversites
Tango or acrobatics: How to capture info groups' memory
No full textThe global tourism system is highly dependent on travel for leisure and is dominated by mass tourism towards summer destinations. The majority of those travels are organised by tour operators as a member of distribution chain of hotel products; that is, the tour operator creates the holiday package and markets it to travel agencies or online channels, and reservations are processed by local travel agencies as host companies who deal with all the travel processes as a representative or partner of the tour operator. Antalya, the tourism capital of Turkey, is highly dependent on sales from tour operators as a result of the destination’s orientation to mass tourism of sea, sun and sand. Therefore, one of the main marketing actions of hotel marketing executives is to welcome info groups of sales agents from travel agencies and present the hotel property to them so that those agents will recommend their hotel property to their customers and generate sales for the hotel. Those visits are also known as familiarisation trips (fam trips) organised by tour operators and travel agencies, and a minimum of seven or eight hotels are visited by the sales agents in a day to understand the hotel offering in a given destination. However, as a reflection of mass tourism organisation, the welcoming of these groups has also become a mass activity which is performed in similar ways by most hotels. The hotel in this case study looks to do something different so that sales agents will distinguish the hotel from the others to drive sales of the property
Search for heavy resonances decaying to WW, WZ, or WH boson pairs in a final state consisting of a lepton and a large-radius jet in proton-proton collisions at √s = 13 TeV
No full textA search for new heavy resonances decaying to pairs of bosons (WW, WZ, or WH) is presented. The analysis uses data from proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb-1. One of the bosons is required to be a W boson decaying to an electron or muon and a neutrino, while the other boson is required to be reconstructed as a single jet with mass and substructure compatible with a quark pair from a W, Z, or Higgs boson decay. The search is performed in the resonance mass range between 1.0 and 4.5 TeV and includes a specific search for resonances produced via vector boson fusion. The signal is extracted using a two-dimensional maximum likelihood fit to the jet mass and the diboson invariant mass distributions. No significant excess is observed above the estimated background. Model-independent upper limits on the production cross sections of spin-0, spin-1, and spin-2 heavy resonances are derived as functions of the resonance mass and are interpreted in the context of bulk radion, heavy vector triplet, and bulk graviton models. The reported bounds are the most stringent to date.BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN; CAS, MoST, and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER, ERC PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRI (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR, and NRC KI (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contracts No. 675440, No. 724704, No. 752730, No. 758316, No. 765710, No. 824093, No. 884104, and COST Action No. CA16108 (European Union); the Leventis Foundation; the Alfred P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F. R. S.-FNRS and FWO (Belgium) under the "Excellence of Science-EOS"-be.h Project No. 30820817; the Beijing Municipal Science & Technology Commission, No. Z191100007219010; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Deutsche Forschungsgemeinschaft (DFG), under Germany's Excellence Strategy-EXC 2121 "Quantum Universe"-390833306, and under project number 400140256-GRK2497; the Lendulet ("Momentum") Program and the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program UNKP, the NKFIA research grants No. 123842, No. 123959, No. 124845, No. 124850, No. 125105, No. 128713, No. 128786, and No. 129058 (Hungary); the Council of Science and Industrial Research, India; the Latvian Council of Science; the Ministry of Science and Higher Education and the National Science Center, Contracts No. Opus 2014/15/B/ST2/03998 and No. 2015/19/B/ST2/02861 (Poland); the Fundacao para a Ciencia e a Tecnologia, grant CEECIND/01334/2018 (Portugal); the National Priorities Research Program by Qatar National Research Fund; the Ministry of Science and Higher Education, Project No. 14.W03.31.0026 (Russia); the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu, grant No.
MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Stavros Niarchos Foundation (Greece); the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, Contract No. C-1845; and the Weston Havens Foundation (USA).Publisher versio
A longitudinal study on the transformation of farm areas in Çukurova, Turkey
No full textRecently, agricultural production methods have changed drastically in the Çukurova region. Due to the decrease in the need for workforce and the change in agricultural product types in Turkey, there has been a significant transformation in the definition of farming and the use of farm spaces. The main subject of this pilot study is the morphological formation and transformation of the spatial components of farms and the reflections on human behaviour through space syntax. Therefore, six farm areas built since the 1850s in Çukurova were selected. Study aims to find traces of technology and human behaviour in farm spaces, revealing the boundaries between the common and private areas. Two different datasets were obtained to test the validity of the hypothesis. First consists of behavioural data obtained through observations. The second consists of survey diagrams, photogrammetric drone mappings, and aerial photographs from the Civil Aviation Command since 1944 to reveal the changes throughout history. This research shows that use of farms has varied over time in terms of technological changes and living conditions. Recently, the distinction between private and production spaces in the farm layouts has begun to change. These recent morphological changes may be relevant when describing contemporary farm sites. Thus, study is aimed to reveal the spatial adaptation process of the farm areas in Çukurova in this article. Therefore, contemporary agriculture and syntactic studies show how the adaptation of farms has progressed over time. This study also aims to predict spatial planning in sustainability, especially in contemporary/modern agricultural environments
The role of sense of coherence and emotion regulation difficulties in the relationship between early maladaptive schemas and grief
No full textFew studies examine the relationship of grief with interrelated and broad concepts. In this study, the role of sense of coherence and emotion regulation difficulties in the relationship between early maladaptive schemas and grief was investigated with individuals (N = 254) who have lost a close person in the last 5 years. Mediation and moderated mediation analyses revealed that individuals with early maladaptive schemas may experience more complicated grief symptoms through the effect of early maladaptive schemas. For individuals with self-sacrifice schema, difficulties in the grief process were regulated by moderate to high levels of sense of coherence
Evaluating the impact of building envelope on energy performance: Cooling analyses
No full textBuildings require a significant amount of energy for heating, cooling, and lighting. Hence, building energy performance has become one of the most important topics in the
architecture, engineering, and construction (AEC) industry in the last decade. The building envelope plays a critical role in maximizing energy efficiency and decreasing
energy consumption generally. The research objective of this study is to examine and compare the effects of three different building envelope types on energy performance in
a high-rise residential building. A literature review and case study were performed for achieving the research objective of this study. In the literature review, records (i.e.,
journal articles, conference proceedings, and scientific reports) published between 2011 and 2021 were included, and Web of Science and Scopus databases were used. In the
case study, passive methods including building design, orientation, insulation, and window-to-wall ratio were employed for a 10-story reinforced concrete residential
building in Istanbul, Turkey. The energy performance of the different wall, insulation, and glass components utilized in the building was analyzed and compared via
DesignBuilder software. Findings show that each parameter and material have a significant impact on the energy performance of a structure. This research would make
a noteworthy contribution to the AEC literature and industry by analyzing the energy performance of different building envelope types and the appropriate scenarios based
on the location. The results of this study can be used by policymakers and decisionmakers to revise existing codes and policies for new high-rise buildings.Publisher versio
Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton–proton collisions at s√=13TeV
No full textA search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton–proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137fb-1, at a center-of-mass energy s=13TeV. No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN; CAS, MoST, and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER, ERC PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRI (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR, and NRC KI (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the MarieCurie programme and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 724704, 752730, 758316, 765710, 824093, 884104, and COST Action CA16108 (European Union); the Leventis Foundation; the Alfred P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie doorWetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO(Belgium) under the "Excellence of Science -EOS" -be.h project n. 30820817; the Beijing Municipal Science & Technology Commission, No. Z191100007219010; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Deutsche Forschungs-gemeinschaft (DFG), under Germany's Excellence Strategy -EXC 2121 "Quantum Universe" -390833306, and under project number 400140256 -GRK2497; the Lendulet ("Momentum") Programme and the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program UNKP, the NKFIA research grants 123842, 123959, 124845, 124850, 125105, 128713, 128786, and 129058 (Hungary); the Council of Science and Industrial Research, India; the Latvian Council of Science; the Ministry of Science and Higher Education and the National Science Center, contracts Opus 2014/15/B/ST2/03998 and 2015/19/B/ST2/02861 (Poland); the Fundacao para a Ciencia e a Tecnologia, grant CEECIND/01334/2018 (Portugal); the National Priorities Research Program by Qatar National Research Fund; theMinistry of Science and Higher Education, projects no. 14.W03.31.0026 and no. FSWW-2020-0008, and the Russian Foundation for Basic Research, project No.
19-42-703014 (Russia); the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de ExcelenciaMaria de Maeztu, grantMDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Stavros Niarchos Foundation (Greece); the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, contract C-1845; and the Weston Havens Foundation (USA).Publisher versio
Black-box test case selection by relating code changes with previously fixed defects
No full textSoftware continuously changes to address new requirements and to fix defects. Regression testing is performed to ensure that the applied changes do not adversely affect existing functionality. The increasing number of test cases makes it infeasible to execute the whole regression test suite. Test case selection is adopted to select a subset of the test suite, which is associated with the changed parts of the software. These parts are assumed to be error-prone. We present and evaluate a test case selection approach in the context of black-box regression testing of embedded systems. In this context, it is challenging to relate test cases with a set of distinct source code elements to be able to select those test cases associated with the modified parts of the source code. We analyze previously fixed defects for this purpose. We relate test cases that detect these defects with the source files that are previously modified for fixing them. Then, we select test cases related with source code files that are modified in the subsequent revision. The strength of this relation is determined as the number of changes associated with fixed defects previously detected by the same test cases. We conduct a case study on 3 real projects from the consumer electronics domain. Results show that it is possible to detect from 65% up to 85% of the defects detected by the whole test suite by selecting from 30% up to 70% of the test cases
Rate-adaptive streaming of 360-degree videos with head-motion-aware viewport margins
No full textEfficient use of available bandwidth is vital when streaming 360-degree videos as users rarely have enough bandwidth for a pleasant experience. A promising solution is the combination of viewport-dependent streaming using tiled video and rate adaptation, where the goal is to spend most of the available bandwidth for the viewport tiles. However, head motions resulting in a change in the viewport tiles briefly cause low-quality rendering until the new tiles can be replaced with high-quality versions. Previously, viewport margins-fixed regions around the viewport rendered at a medium quality-were proposed to make the viewport changes less abrupt. Later on, Head-motion-aware Viewport Margins (HMAVM) were implemented to further smooth the transitions at the expense of increased bandwidth consumption. In this paper, we manage the overall bandwidth cost of HMAVMs better by first developing a set of algorithms that trade off the quality of some viewport tiles and then making the margin selection part of the rate-adaptation algorithm
GaN HEMT teknolojisini kullanan iki aşamalı geniş bant AB sınıfı yüksek güçlü amplifikatör tasarımı
No full textModern radio systems need broadband, high efficiency power amplifiers to cover a wide frequency spectrum with reliable system performance. Linearity is another critical parameter in power amplifier design and there is a trade-off between linearity and efficiency. Class-AB design presents a compromise in terms of linearity and efficiency for the radio frequency systems. In this thesis, two-stages broadband high power amplifier design using GaN HEMT technology is presented. Simulations and measurements are based on the transistor models provided by the manufacturer. The design has minimum 43 % power added efficiency (PAE) and 47.3 dBm output power over the 0.5 - 2.5 GHz operating frequency.Modern radyo sistemleri, güvenilir sistem performansıyla geniş bir frekans spektrumunu kapsamak için geniş bantlı, yüksek güçlü verimli güç amplifikatörlerine ihtiyaç duyar. Lineerlik güç yükselteci tasarımında diğer bir kritik parametredir ve lineerlik ve verim arasında bir ödünleşim vardır. AB sınıfı tasarım radyo frekansı sistemleri için lineerlik ve verimlilik yönünden bir uzlaşma sunmaktadır. Bu tezde GaN HEMT teknolojisini kullanan iki aşamalı geniş band yüksek güçlü yükselteç tasarımı sunulmaktadır. Simülasyonlar ve ölçümler üretici tarafından sağlanan transistör modellerine dayanmaktadır. Tasarım 0.5 - 2.5 GHz çalışma bandında minimum 43 % güç eklemeli verimlilik ve 47.3 dBm çıkış gücüne sahiptir