1,364 research outputs found

    Integration of Cost andWork Breakdown Structures in the Management of Construction Projects

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    Scope management allows project managers to react when a project underperforms regarding schedule, budget, and/or quality at the execution stage. Scope management can also minimize project changes and budget omissions, as well as improve the accuracy of project cost estimates and risk responses. For scope management to be effective, though, it needs to rely on a robust work breakdown structure (WBS). A robust WBS hierarchically and faithfully reflects all project tasks and work packages so that projects are easier to manage. If done properly, the WBS also allows meeting the project objectives while delivering the project on time, on budget, and with the required quality. This paper analyzes whether the integration of a cost breakdown structure (CBS) can lead to the generation of more robust WBSs in construction projects. Over the last years, some international organizations have standardized and harmonized different cost classification systems (e.g., ISO 12006-2, ISO 81346-12, OmniClass, CoClass, UniClass). These cost databases have also been introduced into building information modeling (BIM) frameworks. We hypothesize that in BIM environments, if these CBSs are used to generate the project WBS, several advantages are gained such as sharper project definition. This enhanced project definition reduces project contradictions at both planning and execution stages, anticipates potential schedule and budget deviations, improves resource allocation, and overall it allows a better response to potential project risks. The hypothesis that the use of CBSs can generate more robust WBSs is tested by the response analysis of a questionnaire survey distributed among construction practitioners and project managers. By means of structural equation modeling (SEM), the correlation (agreement) and perception differences between two 250-respondent subsamples (technical project staff vs. project management staff) are also discussed. Results of this research support the use of CBSs by construction professionals as a basis to generate WBSs for enhanced project management (PM)

    Biometric presentation attack detection: beyond the visible spectrum

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    The increased need for unattended authentication in multiple scenarios has motivated a wide deployment of biometric systems in the last few years. This has in turn led to the disclosure of security concerns specifically related to biometric systems. Among them, presentation attacks (PAs, i.e., attempts to log into the system with a fake biometric characteristic or presentation attack instrument) pose a severe threat to the security of the system: any person could eventually fabricate or order a gummy finger or face mask to impersonate someone else. In this context, we present a novel fingerprint presentation attack detection (PAD) scheme based on i) a new capture device able to acquire images within the short wave infrared (SWIR) spectrum, and i i) an in-depth analysis of several state-of-theart techniques based on both handcrafted and deep learning features. The approach is evaluated on a database comprising over 4700 samples, stemming from 562 different subjects and 35 different presentation attack instrument (PAI) species. The results show the soundness of the proposed approach with a detection equal error rate (D-EER) as low as 1.35% even in a realistic scenario where five different PAI species are considered only for testing purposes (i.e., unknown attacks

    Biometric authentication via keystroke sound

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    Unlike conventional “one shot ” biometric authentica-tion schemes, continuous authentication has a number of advantages, such as longer time for sensing, ability to rec-tify authentication decisions, and persistent verification of a user’s identity, which are critical in applications de-manding enhanced security. However, traditional modali-ties such as face, fingerprint and keystroke dynamics, have various drawbacks in continuous authentication scenar-ios. In light of this, this paper proposes a novel non-intrusive and privacy-aware biometric modality that utilizes keystroke sound. Given the keystroke sound recorded by a low-cost microphone, our system extracts discriminative features and performs matching between a gallery and a probe sound stream. Motivated by the concept of digraphs used in modeling keystroke dynamics, we learn a virtual alphabet from keystroke sound segments, from which the digraph latency within pairs of virtual letters as well as other statistical features are used to generate match scores. The resultant multiple scores are indicative of the similar-ities between two sound streams, and are fused to make a final authentication decision. We collect a first-of-its-kind keystroke sound database of 45 subjects typing on a keyboard. Experiments on static text-based authentication, demonstrate the potential as well as limitations of this bio-metric modality. 1

    Project Management Competences by Teaching and Research Staff for the Sustained Success of Engineering Education

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    Projects have become an essential instrument for the success of universities. In a context of globalization and increasing complexity, they must sharpen their resourcefulness to face these challenges and adapt to this changing environment. To reach these objectives, they undertake a series of activities of a unique, concrete and temporary nature, not always technical but managerial ones. If universities work with people on projects in the production, transmission and dissemination of knowledge, then they link with society to solve its problems. For this reason, teaching and research staff (TRS) should promote a range of professional project management (PM) competences in different areas for the proper management of the projects in which they take part. Through a Delphi technique, a panel of twenty-four accredited teaching experts who are carrying out significant research and holding directive roles, measured the importance of acquiring and/or improving professional PM competences by their TRS. Consensus and stability reached after two rounds of consultation confirmed there are a series of crucial competences for the practice of relevant teaching and pioneer research. Results obtained are the basis for a gap plan that allows the TRS to participate in and/or lead university projects with greater self-confidence and personal motivation

    Effects of different contextual interference programs in agility (Efectos producidos por diferentes programas de interferencia contextual en la agilidad)

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    En este estudio participaron 76 alumnos de 9-10 años de edad de un colegio público de educación primaria (44 chicos y 32 chicas). Los participantes fueron randomizados en función del resultado del pretest en cuatro grupos: interferencia contextual baja (ICB, n=19), interferencia contextual moderada (ICM, n=19) interferencia contextual alta (ICA, n=19) y Grupo Control (GC, n=19). El objetivo de este estudio fue conocer que método de entrenamiento de la agilidad en función de la interferencia contextual baja, moderada o alta (ICB, ICM e ICA) es más efectivo en escolares de cuarto curso de educación primaria, con el fin de dilucidar qué método de desarrollo de esta capacidad resultó el idóneo en esta etapa de escolarización. La agilidad fue evaluada mediante el test MAT2. Salvo en el grupo control (CG), se obtuvieron diferencias significativas en la agilidad (test MAT2), en todos los grupos después de un programa de intervención de 4 semanas de duración en alumnos del cuarto curso de primaria. Estas diferencias han sido superiores en el grupo de ICM (p<0,01, ES=1,12). Se encontraron diferencias significativas (p<0,05, ES=0,79) en el postest entre el grupo de ICM e ICB. This study involved 76 students from 9-10 years old in a public elementary school (44 boys and 32 girls). Participants were randomized to the outcome of the pretest into four groups: low contextual interference (ICB, n = 19), moderate contextual interference (ICM, n = 19) high contextual interference (ICA, n = 19) and Control Group (GC, n = 19). The aim of this study was to determine which method of agility training (ICB, ICM or ICA) is more effective in primary school children (9-10 years), in order to figure out what method of development of this capacity was the appropriate at this stage of schooling. The agility was evaluated by MAT2 test. Except in the control group (GC), there were significant differences in agility (MAT2 test) in all groups (ICB, ICM and ICA) after an intervention program of 4-week fourth-year students of elementary school. These differences have been higher in the ICM group (p<0.01, ES=1.12). We found significant differences (p<0.05, ES=0.79) in the posttest between the ICM and ICB group

    Biometric antispoofing methods: A survey in face recognition

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    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. J. Galbally, S. Marcel and J. Fierrez, "Biometric Antispoofing Methods", IEEE Access, vol.2, pp. 1530-1552, Dec. 2014In recent decades, we have witnessed the evolution of biometric technology from the rst pioneering works in face and voice recognition to the current state of development wherein a wide spectrum of highly accurate systems may be found, ranging from largely deployed modalities, such as ngerprint, face, or iris, to more marginal ones, such as signature or hand. This path of technological evolution has naturally led to a critical issue that has only started to be addressed recently: the resistance of this rapidly emerging technology to external attacks and, in particular, to spoo ng. Spoo ng, referred to by the term presentation attack in current standards, is a purely biometric vulnerability that is not shared with other IT security solutions. It refers to the ability to fool a biometric system into recognizing an illegitimate user as a genuine one by means of presenting a synthetic forged version of the original biometric trait to the sensor. The entire biometric community, including researchers, developers, standardizing bodies, and vendors, has thrown itself into the challenging task of proposing and developing ef cient protection methods against this threat. The goal of this paper is to provide a comprehensive overview on the work that has been carried out over the last decade in the emerging eld of antispoo ng, with special attention to the mature and largely deployed face modality. The work covers theories, methodologies, state-of-the-art techniques, and evaluation databases and also aims at providing an outlook into the future of this very active eld of research.This work was supported in part by the CAM under Project S2009/TIC-1485, in part by the Ministry of Economy and Competitiveness through the Bio-Shield Project under Grant TEC2012-34881, in part by the TABULA RASA Project under Grant FP7-ICT-257289, in part by the BEAT Project under Grant FP7-SEC-284989 through the European Union, and in part by the Cátedra Universidad Autónoma de Madrid-Telefónica

    Cancer cell plasticity defines response to immunotherapy in cutaneous squamous cell carcinoma

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    Immune checkpoint blockade (ICB) approaches have changed the therapeutic landscape for many tumor types. However, half of cutaneous squamous cell carcinoma (cSCC) patients remain unresponsive or develop resistance. Here, we show that, during cSCC progression in male mice, cancer cells acquire epithelial/mesenchymal plasticity and change their immune checkpoint (IC) ligand profile according to their features, dictating the IC pathways involved in immune evasion. Epithelial cancer cells, through the PD-1/PD-L1 pathway, and mesenchymal cancer cells, through the CTLA-4/CD80 and TIGIT/CD155 pathways, differentially block antitumor immune responses and determine the response to ICB therapies. Accordingly, the anti-PD-L1/TIGIT combination is the most effective strategy for blocking the growth of cSCCs that contain both epithelial and mesenchymal cancer cells. The expression of E-cadherin/Vimentin/CD80/CD155 proteins in cSCC, HNSCC and melanoma patient samples predicts response to anti-PD-1/PD-L1 therapy. Collectively, our findings indicate that the selection of ICB therapies should take into account the epithelial/mesenchymal features of cancer cells. Immune surveillance is critical to prevent the development and progression of cutaneous squamous cell carcinoma (cSCC). Here, the authors show that epithelial-mesenchymal plasticity in cancer cells is associated with changes in their immune checkpoint ligand profile during mouse cSCC progression, which dictates differential responses to immune checkpoint blockade

    Polymorphic Nature of Iron and Degree of Lattice Preferred Orientation Beneath the Earth's Inner Core Boundary

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    Deciphering the polymorphic nature and the degree of iron lattice‐preferred orientation in the Earth's inner core holds a key to understanding the present status and evolution of the inner core. A multiphase lattice‐preferred orientation pattern is obtained for the top 350 km of the inner core by means of the ab initio based Candy Wrapper Velocity Model coupled to a Monte Carlo phase discrimination scheme. The achieved geographic distribution of lattice alignment is characterized by two regions of freezing, namely within South America and the Western Central Pacific, that exhibit an uncommon high degree of lattice orientation. In contrast, widespread regions of melting of relatively weak lattice ordering permeate the rest of the inner core. The obtained multiphase lattice‐preferred orientation pattern is in line with mantle‐constrained geodynamo simulations and allows to setup an ad hoc mineral physics scenario for the complex Earth's inner core. It is found that the cubic phase of iron is the dominating iron polymorph in the outermost part of the inner core

    Directional Sensitivity of Gaze-Collinearity Features in Liveness Detection

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    To increase the trust in using face recognition systems, these need to be capable of differentiating between face images captured from a real person and those captured from photos or similar artifacts presented at the sensor. Methods have been published for face liveness detection by measuring the gaze of a user while the user tracks an object on the screen, which appears at pre-defined, places randomly. In this paper we explore the sensitivity of such a system to different stimulus alignments. The aim is to establish whether there is such sensitivity and if so to explore how this may be exploited for improving the design of the stimulus. The results suggest that collecting feature points along the horizontal direction is more effective than the vertical direction for liveness detection
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