ORCID Profile
0000-0001-7675-6785
Current Organisations
National Technical University of Athens
,
University of South Australia
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Publisher: Springer Science and Business Media LLC
Date: 11-04-2022
Abstract: A search for long-lived particles decaying into muon pairs is performed using proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC in 2017 and 2018, corresponding to an integrated luminosity of 101 fb − 1 . The data sets used in this search were collected with a dedicated dimuon trigger stream with low transverse momentum thresholds, recorded at high rate by retaining a reduced amount of information, in order to explore otherwise inaccessible phase space at low dimuon mass and nonzero displacement from the primary interaction vertex. No significant excess of events beyond the standard model expectation is found. Upper limits on branching fractions at 95% confidence level are set on a wide range of mass and lifetime hypotheses in beyond the standard model frameworks with the Higgs boson decaying into a pair of long-lived dark photons, or with a long-lived scalar resonance arising from a decay of a b hadron. The limits are the most stringent to date for substantial regions of the parameter space. These results can be also used to constrain models of displaced dimuons that are not explicitly considered in this paper.
Publisher: Springer Science and Business Media LLC
Date: 07-2022
Abstract: A search for physics beyond the standard model (SM) in final states with an electron or muon and missing transverse momentum is presented. The analysis uses data from proton-proton collisions at a centre-of-mass energy of 13 TeV, collected with the CMS detector at the LHC in 2016–2018 and corresponding to an integrated luminosity of 138 fb − 1 . No significant deviation from the SM prediction is observed. Model-independent limits are set on the production cross section of W’ bosons decaying into lepton-plus-neutrino final states. Within the framework of the sequential standard model, with the combined results from the electron and muon decay channels a W’ boson with mass less than 5.7 TeV is excluded at 95% confidence level. Results on a SM precision test, the determination of the oblique electroweak W parameter, are presented using LHC data for the first time. These results together with those from the direct W’ resonance search are used to extend existing constraints on composite Higgs scenarios. This is the first experimental exclusion on compositeness parameters using results from LHC data other than Higgs boson measurements.
Publisher: Emerald
Date: 10-04-2017
DOI: 10.1108/IJPSM-08-2016-0132
Abstract: Public sector projects still fail to meet delivery expectations, and the lack of significant project management experience in the Australian public service (APS) has been identified as a contributing factor. The purpose of this paper is to investigate the importance of competencies required for delivering public sector projects, as well as challenges faced by the project managers when operating in a public context. Qualitative semi-structured interviews were used to enlighten the social and operating construct in APS. In parallel, a quantitative survey was used to determine the relative importance of various competencies to effective project delivery. The research concludes that communication, accountability, business alignment, scope and deliverables, change, and project and program orientation are the most important competencies in APS project delivery. Furthermore, there is evidence that the operating environment acts as a barrier to successful project delivery, noting that it does not let project management practice deploy its full potential for increased effectiveness and efficiency. The research findings noted that the specific needs, values and functions of project management in the APS are not well defined, and therefore there were limited criteria against which public sector project management competencies could be designed and measured. This empirical research contributes to the open dialogue of improving efficiency in project management within the APS context. The findings point to the conflict between the operational nature of APS agencies and their project activities, and how they struggle to define themselves as project organizations rather than lack of appreciation to in idual competencies.
Publisher: Elsevier BV
Date: 11-2012
Publisher: Elsevier BV
Date: 07-2014
Publisher: IEEE
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 26-04-2022
Abstract: A direct search for electroweak production of charginos and neutralinos is presented. Events with three or four leptons, with up to two hadronically decaying τ leptons, or two same-sign light leptons are analyzed. The data s le consists of 137 fb − 1 of proton-proton collisions with a center of mass energy of 13 TeV, recorded with the CMS detector at the LHC. The results are interpreted in terms of several simplified models. These represent a broad range of production and decay scenarios for charginos and neutralinos. A parametric neural network is used to target several of the models with large backgrounds. In addition, results using orthogonal search regions are provided for all the models, simplifying alternative theoretical interpretations of the results. Depending on the model hypotheses, charginos and neutralinos with masses up to values between 300 and 1450 GeV are excluded at 95% confidence level.
Publisher: Elsevier BV
Date: 03-2017
Publisher: IOP Publishing
Date: 07-2022
DOI: 10.1088/1748-0221/17/07/P07023
Abstract: A new algorithm is presented to discriminate reconstructed hadronic decays of tau leptons ( τ h ) that originate from genuine tau leptons in the CMS detector against τ h candidates that originate from quark or gluon jets, electrons, or muons. The algorithm inputs information from all reconstructed particles in the vicinity of a τ h candidate and employs a deep neural network with convolutional layers to efficiently process the inputs. This algorithm leads to a significantly improved performance compared with the previously used one. For ex le, the efficiency for a genuine τ h to pass the discriminator against jets increases by 10–30% for a given efficiency for quark and gluon jets. Furthermore, a more efficient τ h reconstruction is introduced that incorporates additional hadronic decay modes. The superior performance of the new algorithm to discriminate against jets, electrons, and muons and the improved τ h reconstruction method are validated with LHC proton-proton collision data at √ s = 13 TeV.
Publisher: MDPI AG
Date: 18-03-2022
DOI: 10.3390/SU14063567
Abstract: The lockdown and social distancing policies to reduce COVID-19 spread and perceived safety threats of COVID-19 significantly affected people’s travel behavior. Greece has been suffering from the COVID-19 pandemic, and people’s mobility behavior has been greatly affected. This study aims at: (1) exploring the variations in in iduals’ trip frequencies by mode and purpose before and after the COVID-19 outbreak (2) understanding the effects of in idual differences (i.e., sociodemographic details) and perceptions towards COVID-19 (i.e., the perceived threats of COVID-19) on people’s mobility behavior changes after the outbreak (3) underlining the in iduals’ perceptions of the COVID-19 threat on the willingness of public transportation usage. Overall, 403 responses were collected in late 2020. A series of random parameter Probit modeling results reveal multiple in idual and perception factors affecting the changes in mobility behavior in Greece. The results from structural equation modeling indicate that perceived COVID-19 threats affect the attitudes and subjective norms towards people’s intentions to use public transportation. The results from this study provide valuable insights for transportation authorities to develop effective strategies to manage traffic during the spread of disease for a possible future epidemic.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 11-2022
Publisher: Springer International Publishing
Date: 03-09-2016
Publisher: Wiley
Date: 30-12-2009
DOI: 10.1002/MDE.1458
Publisher: Springer Science and Business Media LLC
Date: 13-09-2022
Abstract: A search is presented for a heavy W′ boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using proton-proton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb − 1 at a center-of-mass energy of 13 TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are selected using jet substructure techniques to reduce standard model backgrounds, resulting in a distinct three-jet W′ boson decay signature. No significant deviation in data with respect to the standard model background prediction is observed. Upper limits are set at 95% confidence level on the product of the W′ boson cross section and the final state branching fraction. A W′ boson with a mass below 3.1 TeV is excluded, given the benchmark model assumption of democratic branching fractions. In addition, limits are set based on generalizations of these assumptions. These are the most sensitive limits to date for this final state.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2022
DOI: 10.1140/EPJC/S10052-022-10897-7
Abstract: Measurements of the associated production of a W boson and a charm ( $${\\text {c}}$$ c ) quark in proton–proton collisions at a centre-of-mass energy of 8 $$\\,\\text {TeV}$$ TeV are reported. The analysis uses a data s le corresponding to a total integrated luminosity of 19.7 $$\\,\\text {fb}^{-1}$$ fb - 1 collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction $$\\sigma (\\text {p}\\text {p}\\rightarrow \\text {W}+ {\\text {c}}+ \\text {X}) {\\mathcal {B}}(\\text {W}\\rightarrow \\ell \\upnu )$$ σ ( pp → W + c + X ) B ( W → ℓ ν ) , where $$\\ell = \\text {e}$$ ℓ = e or $$\\upmu $$ μ , and the cross section ratio $$\\sigma (\\text {p}\\text {p}\\rightarrow {{\\text {W}}^{+} + \\bar{{\\text {c}}} + \\text {X}}) / \\sigma (\\text {p}\\text {p}\\rightarrow {{\\text {W}}^{-} + {\\text {c}}+ \\text {X}})$$ σ ( pp → W + + c ¯ + X ) / σ ( pp → W - + c + X ) are measured in a fiducial volume and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.
Publisher: American Physical Society (APS)
Date: 20-05-2022
Publisher: Wiley
Date: 14-05-2022
DOI: 10.1002/CSR.2287
Abstract: Companies face new challenges needing to find ways to stand out from the competitors. All companies face new projects, which need to be managed assertively and faster, launching new products on the market ahead of competitors. This strategy requires enormous dexterity and agility within teams, which are increasingly multifaceted, multidisciplinary, and multifunctional. However, teams need to conciliate apparent freedom for creation with the sustainability rules, which are increasingly demanding, such as legislation and image that companies want to pass on to the market in terms of corporate social responsibility, ensuring a sustainable development of the companies. The goal of this work is to investigate and correlate agile project management and sustainability, taking into account that there are strong relationships, as well as to learn how agile project management affects organization's social, environmental, and economical dynamics from the triple bottom line standpoint. The research examines how agile project management ideas are connected to the triple bottom line concepts based on the literature. The framework was based on the theoretical assumptions underpinning the present research. The basic structure of the developed framework is based on the framework of a matrix‐based method for ordering and synthesizing data. Thus, network diagrams have been developed reproducing the links existing in the literature, both explicitly and implicitly. However, they were deeply expanded considering links not previously referred in the literature. An explanation about these new links is also provided, justifying their inclusion. Hence, the new diagrams offer a more complete landscape about how the adoption of agile practices in project management can improve sustainability in its different aspects, and vice‐versa. The findings reveal that implementing agile project management induces direct effects on an organization's social, economic, and environmental dynamics of the companies, as well as in their teams, with a favorable effect on all of them.
Publisher: IEEE
Date: 10-2015
Publisher: American Physical Society (APS)
Date: 05-07-2022
Publisher: Springer Science and Business Media LLC
Date: 13-05-2014
Publisher: IET
Date: 2011
DOI: 10.1049/CP.2011.0253
Publisher: IEEE
Date: 12-2016
Publisher: Inderscience Publishers
Date: 2010
Publisher: Elsevier BV
Date: 02-2014
Publisher: Elsevier BV
Date: 08-2022
Publisher: Springer Science and Business Media LLC
Date: 16-05-2022
Abstract: A search is presented for single production of a vector-like T quark with charge 2 / 3 e , in the decay channel featuring a top quark and a Z boson, with the top quark decaying hadronically and the Z boson decaying to neutrinos. The search uses data collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb − 1 recorded at the CERN LHC in 2016–2018. The search is sensitive to a T quark mass between 0.6 and 1.8 TeV with decay widths ranging from negligibly small up to 30% of the T quark mass. Reconstruction strategies for the top quark are based on the degree of Lorentz boosting of its final state. At 95% confidence level, the upper limit on the product of the cross section and branching fraction for a T quark of small decay width varies between 15 and 602 fb, depending on its mass. For a T quark with decay widths between 10 and 30% of its mass, this upper limit ranges between 16 and 836 fb. For most of the studied range, the results provide the best limits to date. This is the first search for single T quark production based on the full Run 2 data set of the LHC.
Publisher: Informa UK Limited
Date: 12-2010
Publisher: Inderscience Publishers
Date: 2012
Publisher: Springer Science and Business Media LLC
Date: 20-10-2022
DOI: 10.1038/S41567-022-01682-0
Abstract: Since the discovery of the Higgs boson in 2012, detailed studies of its properties have been ongoing. Besides its mass, its width—related to its lifetime—is an important parameter. One way to determine this quantity is to measure its off-shell production, where the Higgs boson mass is far away from its nominal value, and relating it to its on-shell production, where the mass is close to the nominal value. Here we report evidence for such off-shell contributions to the production cross-section of two Z bosons with data from the CMS experiment at the CERN Large Hadron Collider. We constrain the total rate of the off-shell Higgs boson contribution beyond the Z boson pair production threshold, relative to its standard model expectation, to the interval [0.0061, 2.0] at the 95% confidence level. The scenario with no off-shell contribution is excluded at a p -value of 0.0003 (3.6 standard deviations). We measure the width of the Higgs boson as $${{{\\varGamma }}}_{{{{{{\\rm{H}}}}}}}={3.2}_{-1.7}^{+2.4}\\,{{{{{\\rm{MeV}}}}}}$$ Γ H = 3.2 − 1.7 + 2.4 MeV , in agreement with the standard model expectation of 4.1 MeV. In addition, we set constraints on anomalous Higgs boson couplings to W and Z boson pairs.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Springer Science and Business Media LLC
Date: 19-01-2023
DOI: 10.1038/S41567-022-01838-Y
Abstract: Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering – referred to as single-parton scattering – leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/ ψ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process – reconstructed through the decays of J/ ψ mesons into pairs of oppositely charged muons – with a statistical significance above five standard deviations. We measured the inclusive fiducial cross-section to be $$27{2}_{-104}^{+141}\\,{{{\\rm{(stat)}}}}\\,\\pm 17\\,{{{\\rm{(syst)}}}}\\,{{{\\rm{fb}}}}\\,$$ 27 2 − 104 + 141 (stat) ± 17 (syst) fb , and compared it to theoretical expectations for triple-J/ ψ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross-sections, double- and triple-parton scattering are the dominant contributions for the measured process.
Publisher: Springer Science and Business Media LLC
Date: 05-2022
DOI: 10.1140/EPJC/S10052-022-10315-Y
Abstract: Using a data s le of $$\\sqrt{s}=13\\,\\text {TeV}$$ s = 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of $$103\\text {~fb}^{-1}$$ 103 fb - 1 , the $$\\text {B}^{0}_{\\mathrm{s}} \\rightarrow \\uppsi (\\text {2S})\\text {K}_\\mathrm{S}^{0}$$ B s 0 → ψ ( 2S ) K S 0 and $$\\text {B}^{0} \\rightarrow \\uppsi (\\text {2S})\\text {K}_\\mathrm{S}^{0} \\uppi ^+\\uppi ^-$$ B 0 → ψ ( 2S ) K S 0 π + π - decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to $${\\mathcal {B}}(\\text {B}^{0}_{\\mathrm{s}} \\rightarrow \\uppsi (\\text {2S})K_\\mathrm{S}^{0})/{\\mathcal {B}}(\\text {B}^{0}\\rightarrow \\uppsi (\\text {2S})K_\\mathrm{S}^{0}) = (3.33 \\pm 0.69 (\\text {stat})\\, \\pm 0.11\\,(\\text {syst}) \\pm 0.34\\,(f_{\\mathrm{s}}/f_{\\mathrm{d}})) \\times 10^{-2}$$ B ( B s 0 → ψ ( 2S ) K S 0 ) / B ( B 0 → ψ ( 2S ) K S 0 ) = ( 3.33 ± 0.69 ( stat ) ± 0.11 ( syst ) ± 0.34 ( f s / f d ) ) × 10 - 2 and $${\\mathcal {B}}(\\text {B}^{0} \\rightarrow \\uppsi (\\text {2S})\\text {K}_\\mathrm{S}^{0} \\uppi ^{+} \\uppi ^{-})/ {\\mathcal {B}}(\\text {B}^{0} \\rightarrow \\uppsi (\\text {2S})\\text {K}^{0}_{\\mathrm{S}}) = 0.480 \\pm 0.013\\,(\\text {stat}) \\pm 0.032\\,(\\text {syst})$$ B ( B 0 → ψ ( 2S ) K S 0 π + π - ) / B ( B 0 → ψ ( 2S ) K S 0 ) = 0.480 ± 0.013 ( stat ) ± 0.032 ( syst ) , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of $$\\hbox {B}^{0}_{\\mathrm{s}}$$ B s 0 and $$\\hbox {B}^{0}$$ B 0 mesons, $$f_{\\mathrm{s}}/f_{\\mathrm{d}}$$ f s / f d .
Publisher: MDPI AG
Date: 31-07-2021
Abstract: Even though recent studies designate that sustainability should be integrated in project management, this integration remains a complex issue. Hence, there is a need to develop a new approach that would assess the organizational sustainability and reveal to what extent sustainable project management practices are effective. The aim of this research is to propose a Multi-Criteria Decision Analysis-based method to assess the integration of the sustainability philosophy in large-scale organizations via the utilization of sustainable project management-related indicators. By utilising the proposed approach to compare internal organizational structures, the researchers aim to reveal the sustainability integration level within different business units, in order to allow organizations to make decisions toward sustainable practices. The indicators used in the proposed model are related to key aspects of organizations and they measure how the departments’ staff utilize sustainable project management processes in their construction projects. The case study was conducted in a market-leading design, engineering, and project management consultancy organization. Evaluating organizational sustainability can help organizations target their efforts in certain areas (enhancing sustainable outcomes). It can also facilitate data collection, analysis, and future projections.
Publisher: American Physical Society (APS)
Date: 14-06-2022
Publisher: Emerald
Date: 04-04-2017
DOI: 10.1108/IJMPB-07-2016-0063
Abstract: One of the major challenges for any project is to prepare and develop an achievable baseline schedule and thus set the project up for success, rather than failure. The purpose of this paper is to explore and investigate research outputs in one of the major causes, optimism bias, to identify problems with developing baseline schedules and analyse mitigation techniques and their effectiveness recommended by research to minimise the impact of this bias. A systematic quantitative literature review was followed, examining Project Management Journals , documenting the mitigation approaches recommended and then reviewing whether these approaches were validated by research. Optimism bias proved to be widely accepted as a major cause of unrealistic scheduling for projects, and there is a common understanding as to what it is and the effects that it has on original baseline schedules. Based upon this review, the most recommended mitigation method is Flyvbjerg’s “Reference class,” which has been developed based upon Kahneman’s “Outside View”. Both of these mitigation techniques are based upon using an independent third party to review the estimate. However, within the papers reviewed, apart from the engineering projects, there has been no experimental and statistically validated research into the effectiveness of this method. The majority of authors who have published on this topic are based in Europe. The short-listed papers for this review referred mainly to non-engineering projects which included information technology focussed ones. Thus, on one hand, empirical research is needed for engineering projects, while on the other hand, the lack of tangible evidence for the effectiveness of methods related to the alleviation of optimism bias issues calls for greater research into the effectiveness of mitigation techniques for not only engineering projects, but for all projects. This paper documents the growth within the project management research literature over time on the topic of optimism bias. Specifically, it documents the various methods recommended to mitigate the phenomenon and highlights quantitatively the research undertaken on the subject. Moreover, it introduces paths for further research.
Publisher: Emerald
Date: 12-05-2021
DOI: 10.1108/IJMPB-01-2019-0014
Abstract: Adverse situations negatively impact project stakeholders’ engagement. Past research has sporadically investigated adverse situations affecting stakeholder engagement but lacks a thorough empirical investigation. The paper aims to discuss this issue. A web survey was designed to address the knowledge gap of the identification of the impactful adverse situations during multi-stakeholder engagement. The research yielded 144 completed responses from multi-stakeholders engaged in globally distributed ICT projects. Exploratory factor analysis revealed eight factors that underpin 26 adverse situations. The top factors, ranked in terms of importance according to their Relative Importance Index (RII) are: dysfunctional conflicts, dearth of reasoning, glitches in project governance, clash of personalities. This research reveals the factors that can impact engagement in the form of meaningful clusters and dimensions and opens-up a future research agenda toward causation and mitigation studies related to adversarial stakeholder engagement. The study focuses on globally distributed ICT projects and has not explored generalizability in other sectors. This research enables project managers and stakeholder analysts to get an understanding on the importance of different dimensions of adverse situations in the way stakeholders think, act and emote. Awareness on the potential adversarial stakeholder engagement helps in effectively managing the sustained stakeholder relationships and mental well-being of project stakeholders. This research contributes to project management practice, as it reveals the underlying factors of adverse situations occurring during multi-stakeholders’ engagement, provides clarity on their components and ranks them in terms of importance for their overall effect on stakeholders’ engagement.
Publisher: MDPI AG
Date: 14-04-2023
DOI: 10.3390/SU15086638
Abstract: During the last years, renewable energy strategies for sustainable development perform as best practices and strategic insights necessary to support large scale organizations’ approach to sustainability. Power purchase agreements (PPAs) enhance the value of such initiatives. A renewable PPA contract delivers green energy efficiently to organizations that seek sustainability benefits. Consequently, various approaches that define PPAs are utilized to motivate both interested parties to participate in such deals. Highlighting sustainability tactics during negotiations and identifying relative impacts during the projects’ implementation are both necessary. Following the methodological approach of this study, open-ended criteria are used to identify vital negotiation pricing patterns that permit practitioners to deliver win–win outcomes. The aim of this research is to introduce a multicriteria decision analysis-based method, namely PROMETHEE, to evaluate the implementation of sustainability-related strategies using PPAs. This paper proposes a method for ranking alternative sustainable energy strategies in order for decision-makers to be able to select the most appropriate PPA structure for an organization.
Publisher: MDPI AG
Date: 10-02-2022
DOI: 10.3390/SU14042009
Abstract: The events industry is a project-based industry where sustainable development has been of ever-increasing interest over the last decade. In this regard, the importance of managing risks and delivering quality outcomes in corporate events and the events industry in general cannot be overstated. This paper aims to contribute to the enhancement of project management processes and quality of corporate events, with a focus on risk management. For this purpose, a set of semi-structured interviews with event managers was conducted and thematic analysis was used to qualitatively analyse the research data gathered. Data analysis resulted in the development of a set of tools and methods that have the potential to assist corporate event managers in the project risk management process. This set comprises of a work breakdown structure (WBS) template, a risk breakdown structure (RBS), and a set of risk treatment and mitigation strategies for corporate events. These tools are innovative in the sense that they are based on and correspond to the phases of the event life-cycle rather than in idual management domains, have not been developed in unison before, and can be utilized collectively for greater benefits realization.
Publisher: Informa UK Limited
Date: 30-10-2020
Publisher: American Physical Society (APS)
Date: 18-08-2022
Publisher: Emerald
Date: 24-09-2021
DOI: 10.1108/IJMPB-01-2019-0007
Abstract: Despite the advent of sophisticated control methods, there are still significant issues regarding late delivery of information technology projects. The purpose of this paper is to investigate the common causes of scheduling problems specifically in the information technology projects context. Through a quantitative research, the importance of those causes, as well as the underpinning factors driving them, is explored. The causes are ranked according to their relative important index, and exploratory factor analysis is employed to reveal underlying dimensions (factors) of these causes. From the analysis, four factors were extracted, namely, “Dataless Newbie,” “Technical Newbie,” “Pragmatic Futurist” and “Optimistic Politician.” These factors explain the different latent conditions that lead to scheduling problems in information technology projects. The key contribution of this research is that it enlightens the latent conditions underpinning scheduling problems. Also, the evidence provides that schedule development for information technology projects is impacted by the same causes that impact engineering projects, and that applying a number of mitigation techniques widely used within the engineering area, such as reference class, would, no doubt, not only improve information technology schedules but also reduce the political pressures on the project manager. This research provides a valuable insight into understanding the underlying factors for poor project estimation.
Publisher: IEEE
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 04-08-2022
Abstract: A measurement of the forward-backward asymmetry of pairs of oppositely charged leptons (dimuons and dielectrons) produced by the Drell-Yan process in proton-proton collisions is presented. The data s le corresponds to an integrated luminosity of 138 fb − 1 collected with the CMS detector at the LHC at a center-of-mass energy of 13 TeV. The asymmetry is measured as a function of lepton pair mass for masses larger than 170 GeV and compared with standard model predictions. An inclusive measurement across both channels and the full mass range yields an asymmetry of 0 . 612 ± 0 . 005 (stat) ± 0 . 007 (syst). As a test of lepton flavor universality, the difference between the dimuon and dielectron asymmetries is measured as well. No statistically significant deviations from standard model predictions are observed. The measurements are used to set limits on the presence of additional gauge bosons. For a Z′ boson in the sequential standard model the observed (expected) 95% confidence level lower limit on the Z′ mass is 4.4 TeV (3.7 TeV).
Publisher: Emerald
Date: 25-06-2019
DOI: 10.1108/ECAM-07-2018-0307
Abstract: The purpose of this paper is to systematically develop a delay risk terminology and taxonomy. This research also explores two external and internal dimensions of the taxonomy to determine how much the taxonomy as a whole or combinations of its elements are generalisable. Using mixed methods research, this systematic literature review incorporated data from 46 articles to establish delay risk terminology and taxonomy. Qualitative data of the top 10 delay risks identified in each article were coded based on the grounded theory and constant comparative analysis using a three-stage coding approach. Word frequency analysis and cross-tabulation were used to develop the terminology and taxonomy. Association rules within the taxonomy were also explored to define risk paths and to unmask associations among the risks. In total, 26 delay risks were identified and grouped into ten categories to form the risk breakdown structure. The universal delay risks and other delay risks that are more or less depending on the project location were determined. Also, it is realized that delays connected to equipment, sub-contractors and design drawings are highly connected to project planning, finance and owner slow decision making, respectively. The established terminology and taxonomy may be used in manual or automated risk management systems as a baseline for delay risk identification, management and communication. In addition, the association rules assist the risk management process by enabling mitigation of a combination of risks together.
Publisher: American Physical Society (APS)
Date: 13-07-2022
Publisher: American Physical Society (APS)
Date: 06-07-2022
Publisher: Springer Science and Business Media LLC
Date: 07-2022
Abstract: The associated production of a W and a Z boson is studied in final states with multiple leptons produced in proton-proton (pp) collisions at a centre-of-mass energy of 13 TeV using 137 fb − 1 of data collected with the CMS detector at the LHC. A measurement of the total inclusive production cross section yields σ tot (pp → WZ) = 50 . 6 ± 0 . 8 (stat) ± 1 . 5 (syst) ± 1 . 1 (lumi) ± 0 . 5 (theo) pb. Measurements of the fiducial and differential cross sections for several key observables are also performed in all the final-state lepton flavour and charge compositions with a total of three charged leptons, which can be electrons or muons. All results are compared with theoretical predictions computed up to next-to-next-to-leading order in quantum chromodynamics plus next-to-leading or- der in electroweak theory and for various sets of parton distribution functions. The results include direct measurements of the charge asymmetry and the W and Z vector boson polarization. The first observation of longitudinally polarized W bosons in WZ production is reported. Anomalous gauge couplings are searched for, leading to new constraints on beyond-the-standard-model contributions to the WZ triple gauge coupling.
Publisher: Springer International Publishing
Date: 04-10-2019
Publisher: Springer Science and Business Media LLC
Date: 10-2014
Publisher: Informa UK Limited
Date: 29-07-2014
Publisher: IEEE
Date: 12-2011
Publisher: Springer Science and Business Media LLC
Date: 15-06-2022
Abstract: Results are presented from a search for charged-lepton flavor violating (CLFV) interactions in top quark production and decay in pp collisions at a center-of-mass energy of 13 TeV. The events are required to contain one oppositely charged electron-muon pair in the final state, along with at least one jet identified as originating from a bottom quark. The data correspond to an integrated luminosity of 138 fb − 1 , collected by the CMS experiment at the LHC. This analysis includes both the production (q → e μ t) and decay (t → e μ q) modes of the top quark through CLFV interactions, with q referring to a u or c quark. These interactions are parametrized using an effective field theory approach. With no significant excess over the standard model expectation, the results are interpreted in terms of vector-, scalar-, and tensor-like CLFV four-fermion effective interactions. Finally, observed exclusion limits are set at 95% confidence levels on the respective branching fractions of a top quark to an e μ pair and an up (charm) quark of 0 . 13 × 10 − 6 (1 . 31 × 10 − 6 ), 0 . 07 × 10 − 6 (0 . 89 × 10 − 6 ), and 0 . 25 × 10 − 6 (2 . 59 × 10 − 6 ) for vector, scalar, and tensor CLFV interactions, respectively.
Publisher: University of Technology, Sydney (UTS)
Date: 21-09-2017
Abstract: Stress is a recognised feature of the project managers’ life. Projects are becoming more complex with the uncertainty in the system contributing to the lack of control and added stress. This study explores a microcosm of 25 project managers in the South Australian construction industry, their perceived level of uncertainty and stress. The project managers interviewed provide their views on what their key stressors were and the mechanisms they use to manage effectively their stress. The results showed that structural, technical and directional complexity of projects was high, but this did not always convert into more stress for the project managers. The results indicate that stressors like the lack of resources lack of control and increasing accountability were project managers’ primary concerns. Coping strategies included optimism, applying emotional intelligence and active planning strategies. In addition, they reduced their stress by working with good teams, using theirs and their team's experience, implementing sound systems and processes and effectively researching and gathering information.
Publisher: IEEE
Date: 12-2014
Publisher: Inderscience Publishers
Date: 2011
Publisher: American Physical Society (APS)
Date: 28-06-2022
Publisher: MDPI AG
Date: 05-2022
DOI: 10.3390/SU14095453
Abstract: Projects have grown into more dynamic and complex endeavors, and agile project management should be considered as a way to deal with them. This is a novel study in this field, because the implementation of agile project management in the automotive industry was not explored so far, thus, this work intended to fill this gap, by identifying barriers in the implementation of agile methodologies in project management regarding the automotive industry. This was conducted through a questionnaire survey, which was developed and distributed to 148 manufacturing companies of components for the automotive industry, out of a total number of companies of 240, and 56 complete answers were obtained (23.33%). Statistical analyses were performed using a Kruskal–Wallis test, a Mann–Whitney test, and Spearmen’s correlation. A real picture of the implementation of agile project management in the Portuguese automotive industry is depicted through this work. ‘Organizational’, ‘Knowledge and Technology’, ‘Institutional’, and ‘Financial’ barriers are found to be the most important. However, in overcoming these barriers, companies can be more sustainable in economic, environmental, and social terms. Recommendations on how to overcome these barriers were presented, and a framework sequencing these recommendations was presented, leading to an effective implementation of agile methodologies. It starts with the willingness of the company, and all collaborators, to adopt the agile methodologies, looking for the agile values as an input in order to achieve a competitive advantage. It is followed by an initial investment, which intends to attain the deployment of an agile team, composed of highly skilled collaborators with a clear understanding of the agile objectives, who disseminate knowledge about agile methodologies to the other collaborators, increasing their ability to implement agile methodologies in project management. This team should work and develop frameworks and workflows, according to each company’s characteristics and environment. The studied aspects can be replicated in other countries, and allow a comparison of the situation between countries, trying to correlate the culture of each country with the ability to implement agile methodologies, among other aspects, such as economical level of the companies, type of production, and the commitment of the collaborators to improve processes and create competitive advantages with which to face competitors.
Publisher: Wiley
Date: 18-01-2013
DOI: 10.1002/CAE.20450
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 06-2022
Publisher: American Physical Society (APS)
Date: 31-05-2022
Publisher: Springer Science and Business Media LLC
Date: 07-2019
Abstract: A search for heavy neutral leptons (HNLs), the right-handed Dirac or Majorana neutrinos, is performed in final states with three charged leptons (electrons or muons) using proton-proton collision data collected by the CMS experiment at $$ \\sqrt{s} $$ s = 13 TeV at the CERN LHC. The data correspond to an integrated luminosity of 138 fb − 1 . The HNLs could be produced through mixing with standard model neutrinos ν . For small values of the HNL mass ( 20 GeV) and the square of the HNL- ν mixing parameter (10 − 7 –10 − 2 ), the decay length of these particles can be large enough so that the secondary vertex of the HNL decay can be resolved with the CMS silicon tracker. The selected final state consists of one lepton emerging from the primary proton-proton collision vertex, and two leptons forming a displaced, secondary vertex. No significant deviations from the standard model expectations are observed, and constraints are obtained on the HNL mass and coupling strength parameters, excluding previously unexplored regions of parameter space in the mass range 1–20 GeV and squared mixing parameter values as low as 10 − 7 .
Publisher: Springer Science and Business Media LLC
Date: 29-06-2022
Abstract: The first collider search for dark matter arising from a strongly coupled hidden sector is presented and uses a data s le corresponding to 138 fb −1 , collected with the CMS detector at the CERN LHC, at $$ \\sqrt{s} $$ s = 13 TeV. The hidden sector is hypothesized to couple to the standard model (SM) via a heavy leptophobic Z′ mediator produced as a resonance in proton-proton collisions. The mediator decay results in two “semivisible” jets, containing both visible matter and invisible dark matter. The final state therefore includes moderate missing energy aligned with one of the jets, a signature ignored by most dark matter searches. No structure in the dijet transverse mass spectra compatible with the signal is observed. Assuming the Z′ boson has a universal coupling of 0.25 to the SM quarks, an inclusive search, relevant to any model that exhibits this kinematic behavior, excludes mediator masses of 1.5–4.0 TeV at 95% confidence level, depending on the other signal model parameters. To enhance the sensitivity of the search for this particular class of hidden sector models, a boosted decision tree (BDT) is trained using jet substructure variables to distinguish between semivisible jets and SM jets from background processes. When the BDT is employed to identify each jet in the dijet system as semivisible, the mediator mass exclusion increases to 5.1 TeV, for wider ranges of the other signal model parameters. These limits exclude a wide range of strongly coupled hidden sector models for the first time.
Location: Greece
Start Date: 2012
End Date: 2015
Funder: General Secretariat for Research and Technology
View Funded ActivityStart Date: 2000
End Date: 2002
Funder: Fifth Framework Programme
View Funded ActivityStart Date: 2015
End Date: 2017
Funder: University of South Australia
View Funded Activity