3,874 research outputs found

    Unmanned aerial vehicles in the construction industry - Towards a protocol for safe preparation and flight of drones

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    Purpose: Unmanned aerial vehicles (UAV), colloquially called drones, are widely applied in many sectors of the economy, including the construction industry. They are used for building inspections, damage assessment, land measurements, safety inspections, monitoring the progress of works, and others. Design/methodology/approach: The study notes that UAV pose new, and not yet present, risks in the construction industry. New threats arise, among others, from the development of new technologies, as well as from the continuous automation and robotization of the construction industry. Education regarding the safe use of UAV and the proper use of drones has a chance to improve the safety of work when using these devices. Findings: The procedure (protocol) was developed for the correct and safe preparation and planning of an unmanned aerial vehicle flight during construction operations. Originality/value: Based on the analysis of available sources, no such complete procedure has yet been developed for the correct, i.e. compliant with applicable legal regulations and occupational health and safety issues, preparation for flying UAV. The verification and validation of the developed flight protocol was performed on a sample of over 100 different flight operations

    A first step to accelerating fingerprint matching based on deformable minutiae clustering

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    Fingerprint recognition is one of the most used biometric methods for authentication. The identification of a query fingerprint requires matching its minutiae against every minutiae of all the fingerprints of the database. The state-of-the-art matching algorithms are costly, from a computational point of view, and inefficient on large datasets. In this work, we include faster methods to accelerating DMC (the most accurate fingerprint matching algorithm based only on minutiae). In particular, we translate into C++ the functions of the algorithm which represent the most costly tasks of the code; we create a library with the new code and we link the library to the original C# code using a CLR Class Library project by means of a C++/CLI Wrapper. Our solution re-implements critical functions, e.g., the bit population count including a fast C++ PopCount library and the use of the squared Euclidean distance for calculating the minutiae neighborhood. The experimental results show a significant reduction of the execution time in the optimized functions of the matching algorithm. Finally, a novel approach to improve the matching algorithm, considering cache memory blocking and parallel data processing, is presented as future work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Evolutionary optimization of service times in interactive voice response systems

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    A call center is a system used by companies to provide a number of services to customers, which may vary from providing simple information to gathering and dealing with complaints or more complex transactions. The design of this kind of system is an important task, since the trend is that companies and institutions choose call centers as the primary option for customer relationship management. This paper presents an evolutionary algorithm based on Dandelion encoding to obtain near-optimal service trees which represent the structure of the desired call center. We introduce several modifications to the original Dandelion encoding in order to adapt it to the specific problem of service tree design. Two search space size reduction procedures improve the performance of the algorithm. Systematic experiments have been tackled in order to show the performance of our approach: first, we tackle different synthetic instances, where we discuss and analyze several aspects of the proposed evolutionary algorithm, and second, we tackle a real application, the design of the call center of an Italian telecommunications company. In all the experiments carried out we compare our approach with a lower bound for the problem based on information theory, and also with the results of a Huffman algorithm we have used for reference

    Induced and logarithmic distances with multi-region aggregation operators

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    Copyright © 2019 The Author(s). Published by VGTU Press. This paper introduces the induced ordered weighted logarithmic averaging IOWLAD and multiregion induced ordered weighted logarithmic averaging MR-IOWLAD operators. The distinctive characteristic of these operators lies in the notion of distance measures combined with the complex reordering mechanism of inducing variables and the properties of the logarithmic averaging operators. The main advantage of MR-IOWLAD operators is their design, which is specifically thought to aid in decision-making when a set of diverse regions with different properties must be considered. Moreover, the induced weighting vector and the distance measure mechanisms of the operator allow for the wider modeling of problems, including heterogeneous information and the complex attitudinal character of experts, when aiming for an ideal scenario. Along with analyzing the main properties of the IOWLAD operators, their families and specific cases, we also introduce some extensions, such as the induced generalized ordered weighted averaging IGOWLAD operator and Choquet integrals. We present the induced Choquet logarithmic distance averaging ICLD operator and the generalized induced Choquet logarithmic distance averaging IGCLD operator. Finally, an illustrative example is proposed, including real-world information retrieved from the United Nations World Statistics for global regions

    Detection of curved lines with B-COSFIRE filters: A case study on crack delineation

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    The detection of curvilinear structures is an important step for various computer vision applications, ranging from medical image analysis for segmentation of blood vessels, to remote sensing for the identification of roads and rivers, and to biometrics and robotics, among others. %The visual system of the brain has remarkable abilities to detect curvilinear structures in noisy images. This is a nontrivial task especially for the detection of thin or incomplete curvilinear structures surrounded with noise. We propose a general purpose curvilinear structure detector that uses the brain-inspired trainable B-COSFIRE filters. It consists of four main steps, namely nonlinear filtering with B-COSFIRE, thinning with non-maximum suppression, hysteresis thresholding and morphological closing. We demonstrate its effectiveness on a data set of noisy images with cracked pavements, where we achieve state-of-the-art results (F-measure=0.865). The proposed method can be employed in any computer vision methodology that requires the delineation of curvilinear and elongated structures.Comment: Accepted at Computer Analysis of Images and Patterns (CAIP) 201

    Numerical analysis of precast concrete segmental bridge decks

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    Precast Concrete Segmental Bridges are nowadays a well-established alternative for bridge construction that presents significative advantages related to the construction process. Numerous bridges have been built using this technology in the past decades and extensive research has been conducted, including the development of different numerical models to study their behaviour. This paper proposes a new Finite Element model for Precast Concrete Segmental Bridge decks capable of reproducing the main characteristics of their behaviour at a reduced computational cost. The model proposed has shown very good agreement with experimental results existing in the literature. After calibration, the influence of different modelling choices has been analysed. The results point out to a high impact of the modelling strategy adopted for the joints in the compression areas, requiring an adequate estimation of the point of contact between the segments. Additionally, consideration of friction of external tendons at the deviators showed limited relevance in the global behaviour of the model but was important for the correct estimation of stress increments in the tendons. Finally, considering or not the presence of epoxy at the joints did not seem to influence significantly the behaviour of the models. The use of shell elements combined with the modelling strategy adopted for the joints offers better accuracy than existing models with a significantly lower computational time

    EXPERIENCIAS, PERCEPCIONES Y NECESIDADES EN LA UCI: REVISIÓN SISTEMÁTICA DE ESTUDIOS CUALITATIVOS.

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    Introduction: The intensity of the experience that represents going through an Intensive Care Unit is undeniable. A focus of phenomenological type using qualitative methodology can provide us with a relevant view. The objective of our study is to gather the experiences and patient families and nurses needs in the ICU. Methodology: Qualitative systematic revision meta-study. Presentation of 21 studies. Results: The following categories have been used: Patient experiences, patient needs, stress and confrontation strategies; family experiences, family needs; related nurse-family; nurses regarding the experiences of the patient family; nurses experiences; nurses image. Conclusion: The patient-families demand information, an open visit system, personalized attention, human treatment… Nurses demand a wider training in social abilities. The sanitary administration should also consider the family like an attention nucleus in the ICU, providing resources for it.Introducción. La intensidad de la experiencia que supone pasar por una Unidad de Cuidados Intensivos es innegable. Un enfoque de tipo fenomenológico empleando la metodología cualitativa nos puede proporcionar una acertada visión de la misma. El objetivo de nuestro trabajo es recopilar las vivencias, necesidades de los pacientes-familias y enfermeras de estas unidades. Metodología. Metaestudio tipo revisión sistemática cualitativa. 21 estudios incluidos. Resultados. Se han agrupado en las categorías: experiencias del paciente, necesidades del paciente, estrés y estrategias de afrontamiento; vivencias de la familia, necesidades de la familia; relaciones enfermera-familia; las enfermeras respecto a las vivencias del paciente-familia; vivencias de las enfermeras; imagen de las enfermeras. Conclusión. Los pacientes-familias demandan información, un sistema abierto de visitas, atención personalizada, humanización… Las enfermeras demandamos una formación más amplia en habilidades sociales. La gestión sanitaria debe considerar también a la familia como núcleo de atención en estas unidades, proporcionando recursos para ello

    Extinction of Hepatitis C Virus by Ribavirin in Hepatoma Cells Involves Lethal Mutagenesis

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    Lethal mutagenesis, or virus extinction produced by enhanced mutation rates, is under investigation as an antiviral strategy that aims at counteracting the adaptive capacity of viral quasispecies, and avoiding selection of antiviral-escape mutants. To explore lethal mutagenesis of hepatitis C virus (HCV), it is important to establish whether ribavirin, the purine nucleoside analogue used in anti-HCV therapy, acts as a mutagenic agent during virus replication in cell culture. Here we report the effect of ribavirin during serial passages of HCV in human hepatoma Huh-7.5 cells, regarding viral progeny production and complexity of mutant spectra. Ribavirin produced an increase of mutant spectrum complexity and of the transition types associated with ribavirin mutagenesis, resulting in HCV extinction. Ribavirin-mediated depletion of intracellular GTP was not the major contributory factor to mutagenesis since mycophenolic acid evoked a similar decrease in GTP without an increase in mutant spectrum complexity. The intracellular concentration of the other nucleoside-triphosphates was elevated as a result of ribavirin treatment. Mycophenolic acid extinguished HCV without an intervening mutagenic activity. Ribavirin-mediated, but not mycophenolic acid-mediated, extinction of HCV occurred via a decrease of specific infectivity, a feature typical of lethal mutagenesis. We discuss some possibilities to explain disparate results on ribavirin mutagenesis of HCV

    Experiments on Multidimensional Solitons

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    This article presents an overview of experimental efforts in recent years related to multidimensional solitons in Bose-Einstein condensates. We discuss the techniques used to generate and observe multidimensional nonlinear waves in Bose-Einstein condensates with repulsive interactions. We further summarize observations of planar soliton fronts undergoing the snake instability, the formation of vortex rings, and the emergence of hybrid structures.Comment: review paper, to appear as Chapter 5b in "Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment," edited by P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag
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