823 results
Search Results
202. Integrated Surface-Groundwater Modelling of Nitrate Concentration in Mediterranean Rivers, the Júcar River Basin District, Spain
- Abstract
[EN] High nutrient discharge from groundwater (GW) into surface water (SW) have multiple undesirable effects on river water quality. With the aim to estimate the impact of anthropic pressures and river-aquifer interactions on nitrate status in SW, this study integrates two hydrological simulation and water quality models. PATRICAL models SW-GW interactions and RREA models streamflow changes due to human activity. The models were applied to the Jucar River Basin District (RBD), where 33% of the aquifers have a concentration above 50 mg NO3-/L. As a result, there is a direct linear correlation between the nitrate concentration in rivers and aquifers (Jucar r(2) = 0.9, and Turia r(2) = 0.8), since in these Mediterranean basins, the main amount of river flows comes from groundwater discharge. The concentration of nitrates in rivers and GW tends to increase downstream of the district, where artificial surfaces and agriculture are concentrated. The total NO3- load to Jucar RBD rivers was estimated at 10,202 tN/year (239 kg/km(2)/year), from which 99% is generated by diffuse pollution, and 3378 tN/year (79 kg/km(2)/year) is discharged into the Mediterranean Sea. Changes in nitrate concentration in the RBD rivers are strongly related to the source of irrigation water, river-aquifer interactions, and flow regulation. The models used in this paper allow the identification of pollution sources, the forecasting of nitrate concentration in surface and groundwater, and the evaluation of the efficiency of measures to prevent water degradation, among other applications.
- Published
- 2021
203. Chaos and Stability in a New Iterative Family for Solving Nonlinear Equations
- Abstract
[EN] In this paper, we present a new parametric family of three-step iterative for solving nonlinear equations. First, we design a fourth-order triparametric family that, by holding only one of its parameters, we get to accelerate its convergence and finally obtain a sixth-order uniparametric family. With this last family, we study its convergence, its complex dynamics (stability), and its numerical behavior. The parameter spaces and dynamical planes are presented showing the complexity of the family. From the parameter spaces, we have been able to determine different members of the family that have bad convergence properties, as attracting periodic orbits and attracting strange fixed points appear in their dynamical planes. Moreover, this same study has allowed us to detect family members with especially stable behavior and suitable for solving practical problems. Several numerical tests are performed to illustrate the efficiency and stability of the presented family.
- Published
- 2021
204. Memorizing Schroder's Method as an Efficient Strategy for Estimating Roots of Unknown Multiplicity
- Abstract
[EN] In this paper, we propose, to the best of our knowledge, the first iterative scheme with memory for finding roots whose multiplicity is unknown existing in the literature. It improves the efficiency of a similar procedure without memory due to Schroder and can be considered as a seed to generate higher order methods with similar characteristics. Once its order of convergence is studied, its stability is analyzed showing its good properties, and it is compared numerically in terms of their basins of attraction with similar schemes without memory for finding multiple roots.
- Published
- 2021
205. Kid growth comparison between Murciano-Granadina and crossed Murciano-GranadinaxBoer in a mixed rearing system
- Abstract
[EN] Usually, goat dairy farms have a major problem with the kids they produce for sale, due to their low average daily gain, high feed conversion ratio and poor body conformation, which leads to poor profitability. This paper proposes a solution by crossing the dams not used for replacement with males of a meat breed in a mixed rearing system. The results show that crossbred kids (Murciano-GranadinaxBoer) reached the minimum slaughter weight a week earlier than Murciano-Granadina purebred kids, and that there is a decrease of energy content in milk and in the consumption by the kids as their age increases, which shows the importance of having a concentrated feed that complements their needs to express all the genetic potential for growth observed in the references, especially in the crossing of these two breeds. In addition to this, farms that follow this strategy will also be able to improve their profitability through a higher quantity of milk sold. In dairy goats, the low average daily gain and the high conversion ratio for milk and concentrate of the kids mean that their sale price does not offset the costs generated. The hypothesis proposes that a crossbreeding of the Murciano-Granadina breed (MG) with the Boer breed (MGxBoer) will improve the profitability of the kids sold. Thus, the effect of two different groups of kids (purebred MG and crossbred MGxBoer) on birth weight (BW), mortality, average daily gain (ADG), the time for minimum slaughter weight (7 kg) and its variation factors were studied. MGxBoer kids had a 27% greater BW than purebred MG kids (2885 +/- 84 g and 2275 +/- 74 g, respectively), similar ADG (156 +/- 6 g and 142 +/- 6 g, respectively) and mortality (18% and 20%, respectively), and reached minimum slaughter weight a week sooner. ADG was less and less as the lactation period progressed due to a lower milk consumption and milk energy value, which highlights the importance of providing a concentrate that will compensate for this reduced ener
- Published
- 2021
206. Low-Cost System Based on Optical Sensor to Monitor Discharge of Industrial Oil in Irrigation Ditches
- Abstract
[EN] Uncontrolled dumping linked to agricultural vehicles causes an increase in the incorporation of oils into the irrigation system. In this paper, we propose a system based on an optical sensor to monitor oil concentration in the irrigation ditches. Our prototype is based on the absorption and dispersion of light. As a light source, we use Light Emitting Diodes (LEDs) with different colours (white, yellow, blue, green, and red) and a photodetector as a sensing element. To test the sensor's performance, we incorporate industrial oils used by a diesel or gasoline engine, with a concentration from 0 to 0.20 mL(oil)/cm(2). The experiment was carried out at different water column heights, 0 to 20 cm. According to our results, the sensor can differentiate between the presence or absence of diesel engine oil with any LED. For gasoline engine oil, the sensor quantifies its concentration using the red light source; concentrations greater than 0.1 mL(oil)/cm(2) cannot be distinguished. The data gathered using the red LED has an average absolute error of 0.003 mL(oil)/cm(2) (relative error of 15.8%) for the worst case, 15 cm. Finally, the blue LED generates different signals in the photodetector according to the type of oil. We developed an algorithm that combines (i) the white LED, to monitor the presence of oil; (ii) the blue LED, to identify if the oil comes from a gasoline or diesel engine; and (iii) the red LED, to monitor the concentration of oil used by a gasoline engine.
- Published
- 2021
207. Energy and Personality: A Bridge between Physics and Psychology
- Abstract
[EN] The objective of this paper is to present a mathematical formalism that states a bridge between physics and psychology, concretely between analytical dynamics and personality theory, in order to open new insights in this theory. In this formalism, energy plays a central role. First, the short-term personality dynamics can be measured by the General Factor of Personality (GFP) response to an arbitrary stimulus. This GFP dynamical response is modeled by a stimulus¿response model: an integro-differential equation. The bridge between physics and psychology appears when the stimulus¿response model can be formulated as a linear second order differential equation and, subsequently, reformulated as a Newtonian equation. This bridge is strengthened when the Newtonian equation is derived from a minimum action principle, obtaining the current Lagrangian and Hamiltonian functions. However, the Hamiltonian function is non-conserved energy. Then, some changes lead to a conserved Hamiltonian function: Ermakov¿Lewis energy. This energy is presented, as well as the GFP dynamical response that can be derived from it. An application case is also presented: an experimental design in which 28 individuals consumed 26.51 g of alcohol. This experiment provides an ordinal scale for the Ermakov¿Lewis energy that predicts the effect of a single dose of alcohol.
- Published
- 2021
208. An approach to Sustainability Risk Assessment in Industrial Assets
- Abstract
[EN] Asset management, as a global process through which value is added to a company, is a managerial model that involves major changes in strategies, technologies, and resources; risk management; and a change in the attitude of the people involved. The growing commitment of companies to sustainability results in them applying this approach to all their activities. For this reason, it is relevant to develop sustainability risk assessment procedures in industrial assets. This paper presents a methodological framework for the inclusion of sustainability aspects in the risk management of industrial assets. This approach presents a procedure to provide general criteria, methodology, and essential mandatory requirements to be adopted for the identification, analysis, and evaluation of sustainability aspects, impacts, and risks related to assets owned and managed by an industrial company. The proposed procedure is based on ISO 55,000 and ISO 31,000 standards and was developed following three steps: a preliminary study, identification of sustainability aspects and sustainability risks/opportunities, and impact assessment and residual risks management. Our results could serve as a model that facilitates the improvement of sustainability analysis risks in industrial assets and could be used as a basis for future developments in the application of the standards to optimize management of these assets.
- Published
- 2021
209. Robust Resolution-Enhanced Prostate Segmentation in Magnetic Resonance and Ultrasound Images through Convolutional Neural Networks
- Abstract
[EN] Prostate segmentations are required for an ever-increasing number of medical applications, such as image-based lesion detection, fusion-guided biopsy and focal therapies. However, obtaining accurate segmentations is laborious, requires expertise and, even then, the inter-observer variability remains high. In this paper, a robust, accurate and generalizable model for Magnetic Resonance (MR) and three-dimensional (3D) Ultrasound (US) prostate image segmentation is proposed. It uses a densenet-resnet-based Convolutional Neural Network (CNN) combined with techniques such as deep supervision, checkpoint ensembling and Neural Resolution Enhancement. The MR prostate segmentation model was trained with five challenging and heterogeneous MR prostate datasets (and two US datasets), with segmentations from many different experts with varying segmentation criteria. The model achieves a consistently strong performance in all datasets independently (mean Dice Similarity Coefficient -DSC- above 0.91 for all datasets except for one), outperforming the inter-expert variability significantly in MR (mean DSC of 0.9099 vs. 0.8794). When evaluated on the publicly available Promise12 challenge dataset, it attains a similar performance to the best entries. In summary, the model has the potential of having a significant impact on current prostate procedures, undercutting, and even eliminating, the need of manual segmentations through improvements in terms of robustness, generalizability and output resolution
- Published
- 2021
210. Irrigation Post-Modernization. Farmers Envisioning Irrigation Policy in the Region of Valencia (Spain)
- Abstract
[EN] During the last three decades, like many other Mediterranean states, Spain has intensively promoted the modernization of irrigation, focusing mainly on the introduction of pressurized irrigation systems. Following 30 years of investment, a shift in irrigation policies is needed to solve some of the deficiencies in this modernization process and to incorporate new measures to cope with upcoming challenges generated by international markets, climate change and other social and economic processes. This paper describes and analyses the results of participatory research carried out with the water user associations in the autonomous region of Valencia, in order to define post-modernization irrigation policies. A survey and 24 local workshops involving 304 water user associations were conducted during the irrigation season of 2018 in order to form an assessment of the sector and design new irrigation policies. The results show that after 30 years of important investment, the obsolescence of the infrastructure has become the current main priority, making farmers dependent on public subsidies. New necessities have also emerged, such as renewable energies and nonconventional water resources, which farmers consider indispensable in order to reduce operating costs and guarantee water supply.
- Published
- 2021
211. Embodied Energy Optimization of Buttressed Earth-Retaining Walls with Hybrid Simulated Annealing
- Abstract
[EN] The importance of construction in the consumption of natural resources is leading structural design professionals to create more efficient structure designs that reduce emissions as well as the energy consumed. This paper presents an automated process to obtain low embodied energy buttressed earth-retaining wall optimum designs. Two objective functions were considered to compare the difference between a cost optimization and an embodied energy optimization. To reach the best design for every optimization criterion, a tuning of the algorithm parameters was carried out. This study used a hybrid simulated optimization algorithm to obtain the values of the geometry, the concrete resistances, and the amounts of concrete and materials to obtain an optimum buttressed earth-retaining wall low embodied energy design. The relation between all the geometric variables and the wall height was obtained by adjusting the linear and parabolic functions. A relationship was found between the two optimization criteria, and it can be concluded that cost and energy optimization are linked. This allows us to state that a cost reduction of €1 has an associated energy consumption reduction of 4.54 kWh. To achieve a low embodied energy design, it is recommended to reduce the distance between buttresses with respect to economic optimization. This decrease allows a reduction in the reinforcing steel needed to resist stem bending. The difference between the results of the geometric variables of the foundation for the two-optimization objectives reveals hardly any variation between them. This work gives technicians some rules to get optimum cost and embodied energy design. Furthermore, it compares designs obtained through these two optimization objectives with traditional design recommendations.
- Published
- 2021
212. Hot Air and Microwave Combined Drying of Potato Monitored by Infrared Thermography
- Abstract
[EN] Hot air drying (HAD) at temperatures below the spontaneous evaporation temperature could be combined with microwave (MW) radiation as a thermal energy source in order to reduce the drying time. A photon flux in the microwave range interacts with dipolar molecules (water) through orientation and induction, producing electrical energy storage and thermal energy accumulation and generating an increase in the internal energy of food. The different mechanisms involved in water transport could change when the microwave penetration depth exceeds the sample characteristic dimension of mass transport. The aim of this paper is to determine the effect of MW in the combined HAD-MW drying of raw potato in order to obtain the real driving forces and mechanisms involved in the water transport, with the purpose of optimizing the MW power used. For this purpose, combined drying was carried out on potato samples (0, 4 and 6 W/g). The sample surface temperature was monitored by infrared thermography, and the sample mass was measured continuously through a precision balance. In parallel with continuous drying, another drying treatment was performed at different times (20, 40, 60, 90, 120, 180, 420 min) and conditions (0, 4 and 6 W/g) to analyze the dielectric properties, mass, moisture, volume and water activity. The results show that it is possible to monitor combined drying by infrared thermography, and it can be concluded that the convection heating is mostly transformed into surface water evaporation, with negligible thermal conduction from the surface, and microwave radiation is mostly transformed into an increase in the potato's internal energy.
- Published
- 2021
213. Neutrosophic Completion Technique for Incomplete Higher-Order AHP Comparison Matrices
- Abstract
[EN] After the recent establishment of the Sustainable Development Goals and the Agenda 2030, the sustainable design of products in general and infrastructures in particular emerge as a challenging field for the development and application of multicriteria decision-making tools. Sustainability-related decision problems usually involve, by definition, a wide variety in number and nature of conflicting criteria, thus pushing the limits of conventional multicriteria decision-making tools practices. The greater the number of criteria and the more complex the relations existing between them in a decisional problem, the less accurate and certain are the judgments required by usual methods, such as the analytic hierarchy process (AHP). The present paper proposes a neutrosophic AHP completion methodology to reduce the number of judgments required to be emitted by the decision maker. This increases the consistency of their responses, while accounting for uncertainties associated to the fuzziness of human thinking. The method is applied to a sustainable-design problem, resulting in weight estimations that allow for a reduction of up to 22% of the conventionally required comparisons, with an average accuracy below 10% between estimates and the weights resulting from a conventionally completed AHP matrix, and a root mean standard error below 15%.
- Published
- 2021
214. Organizational Factors that Drive to BIM Effectiveness: Technological Learning, Collaborative Culture, and Senior Management Support
- Abstract
[EN] Senior management support is a key dynamic capacity for design companies in the architecture, engineering, and construction (AEC) industry, given the fact that they must identify changes in the competitive environment, which are increasingly becoming more and more technological. In addition, senior management support is obliged to react in the most efficient and effective way. Currently, the project design teams that have adopted building information modeling (BIM) are subject to constant changes in the technological environment, of which the activity is influenced by the behavior of senior management support. This research focuses on this issue by analyzing the role played by the variables of technological learning, collaborative culture, and support provided by senior management as precedents of BIM technology effectiveness. The data set has been obtained from 92 AEC companies in Spain. Using partial least squares (PLS), this research finds evidence of the previously mentioned relationships and the existence of partial mediation effects generated by technological learning and collaborative culture within the support of senior management in BIM technology effectiveness. In addition, this model achieves an appropriate level of predictive validation to explain BIM technology effectiveness in engineering project designs. The results highlight that senior management support needs to promote a technological learning and collaborative culture to improve the technological capabilities. The contribution and original value of the paper is to provide empirical evidence that the effectiveness of BIM factors in project design teams is influenced by the behavior of top management support.
- Published
- 2021
215. A Pilot Experience with Software Programming Environments as a Service for Teaching Activities
- Abstract
[EN] Software programming is one of the key abilities for the development of Computational Thinking (CT) skills in Science, Technology, Engineering and Mathematics (STEM). However, specific software tools to emulate realistic scenarios are required for effective teaching. Unfortunately, these tools have some limitations in educational environments due to the need of an adequate configuration and orchestration, which usually assumes an unaffordable work overload for teachers and is inaccessible for students outside the laboratories. To mitigate the aforementioned limitations, we rely on cloud solutions that automate the process of orchestration and configuration of software tools on top of cloud computing infrastructures. This way, the paper presents ACTaaS as a cloud-based educational resource that deploys and orchestrates a whole realistic software programming environment. ACTaaS provides a simple, fast and automatic way to set up a professional integrated environment without involving an overload to the teacher, and it provides an ubiquitous access to the environment. The solution has been tested in a pilot group of 28 students. Currently, there is no tool like ACTaaS that allows such a high grade of automation for the deployment of software production environments focused on educational activities supporting a wide range of cloud providers. Preliminary results through a pilot group predict its effectiveness due to the efficiency to set up a class environment in minutes without overloading the teachers, and providing ubiquitous access to students. In addition, the first student opinions about the experience were greatly positive.
- Published
- 2021
216. Accurate estimations of Any Eigenpairs of N-th Order Linear Boundary Value Problems
- Abstract
[EN] This paper provides a method to bound and calculate any eigenvalues and eigenfunctions of n-th order boundary value problems with sign-regular kernels subject to two-point boundary conditions. The method is based on the selection of a particular type of cone for each eigenpair to be determined, the recursive application of the operator associated to the equivalent integral problem to functions belonging to such a cone, and the calculation of the Collatz-Wielandt numbers of the resulting functions.
- Published
- 2021
217. Novel Semi-Interpenetrated Polymer Networks of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)/Poly (Vinyl Alcohol) with Incorporated Conductive Polypyrrole Nanoparticles
- Abstract
[EN] This paper reports the preparation and characterization of semi-interpenetrating polymer networks (semi-IPN) of poly(3-hydroxybutirate-co-3-hydroxyvalerate), PHBV, and poly (vinyl alcohol), PVA, with conductive polypirrole (PPy) nanoparticles. Stable hybrid semi-IPN (PHBV/PVA 30/70 ratio) hydrogels were produced by solvent casting, dissolving each polymer in chloroform and 1-methyl-2-pyrrolidone respectively, and subsequent glutaraldehyde crosslinking of the PVA chains. The microstructure and physical properties of this novel polymeric system were analysed, including thermal behaviour and degradation, water sorption, wettability and electrical conductivity. The conductivity of these advanced networks rose significantly at higher PPy nanoparticles content. Fourier transform infrared spectroscopy (FTIR) and calorimetry characterization indicated good miscibility and compatibility between all the constituents, with no phase separation and strong interactions between phases. A single glass transition was observed between those of pure PHBV and PVA, although PVA was dominant in its contribution to the glass transition process. Incorporating PPy nanoparticles significantly reduced the hydrogel swelling, even at low concentrations, indicating molecular interactions between the PPy nanoparticles and the hydrogel matrix. The PHBV/PVA semi-IPN showed higher thermal stability than the neat polymers and PHBV/PVA blend, which also remained in the tertiary systems.
- Published
- 2021
218. An Overview about the Current Situation on C&D Waste Management in Italy: Achievements and Challenges
- Abstract
[EN] The disposal volume of material for Construction and Demolition in Europe is increasing each year, that the European Union has decided to take control of the matter unifying practices and goals to achieve. This article analyses how waste management works in Italy adjusting its system to the European Union, regarding Construction and Demolition, taking into consideration the disposal of material coming from C&D (Construction and Demolition) production. In Italy, the disposition may differ according to the regions in which it is divided, and this must be taken into consideration when analysing information that reflects the different logistical aspect linked to the territory. It is also necessary to consider how the volume of waste can vary according to the size of the region considered and the type of industrial development to which it belongs. The analysis of the Italian situation shows their achievements regarding reaching a good level of recycling waste volume; indeed, their amount of C&D recycled waste after 2010 was always up to the 70% value established by the European Union, though barriers are still present in the field of waste management. Through data collecting, it has been seen the different volume that is generated in construction-related activities in the country, along with the recovered waste volume. Thus, the goal of this paper is to deepen the general knowledge on waste produced by Construction and Demolition in Italy and waste management practices adopted according to the European Union.
- Published
- 2021
219. New Protocol and Architecture for a Wastewater Treatment System Intended for Irrigation
- Abstract
[EN] Water quality may be affected by aspects such as pollution from industries, agricultural fertilizers and pesticides, and waste produced by humans. This contamination can affect the produce of the fields irrigated by untreated water. Therefore, it is necessary to add a treatment process in irrigation systems. In this paper, an architecture, communication protocol, and a data analysis algorithm for a wastewater treatment system intended for irrigation are presented. Our system includes a smart group-based wireless sensor network that is able to detect high salinity levels and pollution stains, such as oil spills. When contamination is detected, the water is led into auxiliary canals that perform the biosorption process to treat the water and dump it back into the main canal. Simulations were performed to assess the amount of data stored on the secure digital (SD) card, the consumed bandwidth, and the energy consumption of our proposal. The results show the system has a low bandwidth consumption with a maximum of 2.58 kbps for the setting of two daily data transmissions of the node in the last auxiliary canal. Furthermore, it can sustain the energy consumption in adverse conditions, where the node with the highest energy consumption reaches the lowest energy value of 12,320 mW/h.
- Published
- 2021
220. Energy and Personality: A Bridge between Physics and Psychology
- Abstract
[EN] The objective of this paper is to present a mathematical formalism that states a bridge between physics and psychology, concretely between analytical dynamics and personality theory, in order to open new insights in this theory. In this formalism, energy plays a central role. First, the short-term personality dynamics can be measured by the General Factor of Personality (GFP) response to an arbitrary stimulus. This GFP dynamical response is modeled by a stimulus¿response model: an integro-differential equation. The bridge between physics and psychology appears when the stimulus¿response model can be formulated as a linear second order differential equation and, subsequently, reformulated as a Newtonian equation. This bridge is strengthened when the Newtonian equation is derived from a minimum action principle, obtaining the current Lagrangian and Hamiltonian functions. However, the Hamiltonian function is non-conserved energy. Then, some changes lead to a conserved Hamiltonian function: Ermakov¿Lewis energy. This energy is presented, as well as the GFP dynamical response that can be derived from it. An application case is also presented: an experimental design in which 28 individuals consumed 26.51 g of alcohol. This experiment provides an ordinal scale for the Ermakov¿Lewis energy that predicts the effect of a single dose of alcohol.
- Published
- 2021
221. Passive Reactive Power Compensators for Improving the Sustainability of Three-Phase Four-Wire Sinusoidal Systems Supplied by Unbalanced Voltages
- Abstract
[EN] Compensation of reactive power is necessary in power systems due to economical, energetic, and environmental reasons. Reactive power increases energy power losses and carbon dioxide emissions in distribution lines and power transformers. However, capacitor banks used in most industrial applications do not significantly reduce energy losses in lines and transformers when supply voltages and loads are unbalanced and therefore do not fully improve the sustainability of distribution networks. This fact is explained in this paper using positive-, negative-, and zero-sequence reactive power components in three-phase, four-wire sinusoidal power systems supplied with unbalanced voltages. Likewise, several devices have also been developed for the compensation of the total reactive power and, specifically, for each of its components in these power systems. Comparing the effectiveness of these reactive compensators and other well-known passive compensators as capacitor banks on the sustainability improvement of the electrical installation of an actual industry, reductions between 20% and 100% in energy losses and carbon dioxide emissions, caused by circulation of reactive currents in transformer and lines, can be expected depending on the type of compensator used.
- Published
- 2021
222. Quadrature Integration Techniques for Random Hyperbolic PDE Problems
- Abstract
[EN] In this paper, we consider random hyperbolic partial differential equation (PDE) problems following the mean square approach and Laplace transform technique. Randomness requires not only the computation of the approximating stochastic processes, but also its statistical moments. Hence, appropriate numerical methods should allow for the efficient computation of the expectation and variance. Here, we analyse different numerical methods around the inverse Laplace transform and its evaluation by using several integration techniques, including midpoint quadrature rule, Gauss-Laguerre quadrature and its extensions, and the Talbot algorithm. Simulations, numerical convergence, and computational process time with experiments are shown
- Published
- 2021
223. Local Energy Communities in Spain: Economic Implications of the New Tariff and Variable Coefficients
- Abstract
[EN] The European Union advocates for legislative support to local energy communities. Measures include the promotion of dynamic energy allocation and discriminatory electricity tariffs such as the recent Spanish framework. However, the impact of these normative changes is not yet evaluated. This paper inquires into the impact of dynamic allocation coefficient and different electricity tariffs on the profitability of local energy communities. To do so, a linear optimisation model is developed and applied to real consumer data in Spain around a variable capacity photovoltaic generation plant. Comparing the economic performance of the static or variable power allocation under the effect of changing electricity tariffs. While both measures are beneficial, the new electricity tariffs result in larger profitability increases than the planned variable coefficients. The combination of measures allows for profitability improvements of up to 25% being complementary measures. However, installations that maximise the potential for electricity generation are still not as profitable due to the low purchase price of surplus energy. While discriminatory electricity price tariffs and variable allocation coefficients are positive measures, further measures are needed for these communities to install generation plants as large as the potential that each case allows.
- Published
- 2021
224. The Relationship between Building Agents in the Context of Integrated Project Management: A Prospective Analysis
- Abstract
[EN] The increasing complexity of building projects, with high quality standards, integrated technologies and strong management restrictions, demands the intervention of numerous and diverse specialists. This requires an intense leadership, organization and coordination effort. However, building regulations, such as the Spanish Law on Building Management (LOE) 38/1999, only formally consider developers, project designers, project and work supervisors, quality control entities, construction companies, owners and final users as building agents. However, these categories are insufficient to represent the interests of all the stakeholders. The purpose of this paper is to carry out an analysis of the agents that are currently part of the entire building process. If their relationship of influence and dependence, as well as their alignment with the overall objectives of the project are studied, potential convergences, divergences, agreements and disagreements can be established. To do this, the authors conducted a prospective analysis through the MACTOR (Matrix of Alliances and Conflicts: Tactics, Objectives and Recommendations) strategic planning simulation tool, for which the rules of the Delphi technique were applied and a consultation with technical experts, both professionals and academics, was held. The research provides insight to assess the power relationships between the building agents, as well as to measure the alignment of objectives with their interests. Results show that, in the context of integrated project management (IPM), the influence of technical agents is reduced by limiting their functions to those marked by their regulatory framework, allowing them to focus on their legal powers, and the room for manoeuvre of the professional agents, who are subject to systematized monitoring and control, is also reduced. The prospective analysis also highlights the importance of defining the scope from its early stages, as well as the need to reach multilateral agr
- Published
- 2021
225. Reliable Efficient Difference Methods for Random Heterogeneous Diffusion Reaction Models with a Finite Degree of Randomness
- Abstract
[EN] This paper deals with the search for reliable efficient finite difference methods for the numerical solution of random heterogeneous diffusion reaction models with a finite degree of randomness. Efficiency appeals to the computational challenge in the random framework that requires not only the approximating stochastic process solution but also its expectation and variance. After studying positivity and conditional random mean square stability, the computation of the expectation and variance of the approximating stochastic process is not performed directly but through using a set of sampling finite difference schemes coming out by taking realizations of the random scheme and using Monte Carlo technique. Thus, the storage accumulation of symbolic expressions collapsing the approach is avoided keeping reliability. Results are simulated and a procedure for the numerical computation is given.
- Published
- 2021
226. An approach to Sustainability Risk Assessment in Industrial Assets
- Abstract
[EN] Asset management, as a global process through which value is added to a company, is a managerial model that involves major changes in strategies, technologies, and resources; risk management; and a change in the attitude of the people involved. The growing commitment of companies to sustainability results in them applying this approach to all their activities. For this reason, it is relevant to develop sustainability risk assessment procedures in industrial assets. This paper presents a methodological framework for the inclusion of sustainability aspects in the risk management of industrial assets. This approach presents a procedure to provide general criteria, methodology, and essential mandatory requirements to be adopted for the identification, analysis, and evaluation of sustainability aspects, impacts, and risks related to assets owned and managed by an industrial company. The proposed procedure is based on ISO 55,000 and ISO 31,000 standards and was developed following three steps: a preliminary study, identification of sustainability aspects and sustainability risks/opportunities, and impact assessment and residual risks management. Our results could serve as a model that facilitates the improvement of sustainability analysis risks in industrial assets and could be used as a basis for future developments in the application of the standards to optimize management of these assets.
- Published
- 2021
227. GPU-Enabled Serverless Workflows for Efficient Multimedia Processing
- Abstract
[EN] Serverless computing has introduced scalable event-driven processing in Cloud infrastructures. However, it is not trivial for multimedia processing to benefit from the elastic capabilities featured by serverless applications. To this aim, this paper introduces the evolution of a framework to support the execution of customized runtime environments in AWS Lambda in order to accommodate workloads that do not satisfy its strict computational requirements: increased execution times and the ability to use GPU-based resources. This has been achieved through the integration of AWS Batch, a managed service to deploy virtual elastic clusters for the execution of containerized jobs. In addition, a Functions Definition Language (FDL) is introduced for the description of data-driven workflows of functions. These workflows can simultaneously leverage both AWS Lambda for the highly-scalable execution of short jobs and AWS Batch, for the execution of compute-intensive jobs that can profit from GPU-based computing. To assess the developed open-source framework, we executed a case study for efficient serverless video processing. The workflow automatically generates subtitles based on the audio and applies GPU-based object recognition to the video frames, thus simultaneously harnessing different computing services. This allows for the creation of cost-effective highly-parallel scale-to-zero serverless workflows in AWS.
- Published
- 2021
228. On the Approximated Solution of a Special Type of Nonlinear Third-Order Matrix Ordinary Differential Problem
- Abstract
[EN] Matrix differential equations are at the heart of many science and engineering problems. In this paper, a procedure based on higher-order matrix splines is proposed to provide the approximated numerical solution of special nonlinear third-order matrix differential equations, having the form Y-(3)(x)=f(x,Y(x)). Some numerical test problems are also included, whose solutions are computed by our method.
- Published
- 2021
229. Implementation of Autoencoders with Systolic Arrays through OpenCL
- Abstract
[EN] In the world of algorithm acceleration and the implementation of deep neural networks' recall phase, OpenCL based solutions have a clear tendency to produce perfectly adapted kernels in graphic processor unit (GPU) architectures. However, they fail to obtain the same results when applied to field-programmable gate array (FPGA) based architectures. This situation, along with an enormous advance in new GPU architectures, makes it unfeasible to defend an acceleration solution based on FPGA, even in terms of energy efficiency. Our goal in this paper is to demonstrate that multikernel structures can be written based on classic systolic arrays in OpenCL, trying to extract the most advanced features of FPGAs without having to resort to traditional FPGA development using lower level hardware description languages (HDLs) such as Verilog or VHDL. This OpenCL methodology is based on the intensive use of channels (IntelFPGA extension of OpenCL) for the communication of both data and control and on the refinement of the OpenCL libraries using register transfer logic (RTL) code to improve the performance of the implementation of the base and activation functions of the neurons and, above all, to reflect the importance of adequate communication between the layers when implementing neuronal networks
- Published
- 2021
230. Chaos and Stability in a New Iterative Family for Solving Nonlinear Equations
- Abstract
[EN] In this paper, we present a new parametric family of three-step iterative for solving nonlinear equations. First, we design a fourth-order triparametric family that, by holding only one of its parameters, we get to accelerate its convergence and finally obtain a sixth-order uniparametric family. With this last family, we study its convergence, its complex dynamics (stability), and its numerical behavior. The parameter spaces and dynamical planes are presented showing the complexity of the family. From the parameter spaces, we have been able to determine different members of the family that have bad convergence properties, as attracting periodic orbits and attracting strange fixed points appear in their dynamical planes. Moreover, this same study has allowed us to detect family members with especially stable behavior and suitable for solving practical problems. Several numerical tests are performed to illustrate the efficiency and stability of the presented family.
- Published
- 2021
231. Cyber-Attack Detection in Water Distribution Systems Based on Blind Sources Separation Technique
- Abstract
[EN] Service quality and efficiency of urban systems have been dramatically boosted by various high technologies for real-time monitoring and remote control, and have also gained privileged space in water distribution. Monitored hydraulic and quality parameters are crucial data for developing planning, operation and security analyses in water networks, which makes them increasingly reliable. However, devices for monitoring and remote control also increase the possibilities for failure and cyber-attacks in the systems, which can severely impair the system operation and, in extreme cases, collapse the service. This paper proposes an automatic two-step methodology for cyber-attack detection in water distribution systems. The first step is based on signal-processing theory, and applies a fast Independent Component Analysis (fastICA) algorithm to hydraulic time series (e.g., pressure, flow, and tank level), which separates them into independent components. These components are then processed by a statistical control algorithm for automatic detection of abrupt changes, from which attacks may be disclosed. The methodology is applied to the case study provided by the Battle of Attack Detection Algorithms (BATADAL) and the results are compared with seven other approaches, showing excellent results, which makes this methodology a reliable early-warning cyber-attack detection approach
- Published
- 2021
232. Integrated Surface-Groundwater Modelling of Nitrate Concentration in Mediterranean Rivers, the Júcar River Basin District, Spain
- Abstract
[EN] High nutrient discharge from groundwater (GW) into surface water (SW) have multiple undesirable effects on river water quality. With the aim to estimate the impact of anthropic pressures and river-aquifer interactions on nitrate status in SW, this study integrates two hydrological simulation and water quality models. PATRICAL models SW-GW interactions and RREA models streamflow changes due to human activity. The models were applied to the Jucar River Basin District (RBD), where 33% of the aquifers have a concentration above 50 mg NO3-/L. As a result, there is a direct linear correlation between the nitrate concentration in rivers and aquifers (Jucar r(2) = 0.9, and Turia r(2) = 0.8), since in these Mediterranean basins, the main amount of river flows comes from groundwater discharge. The concentration of nitrates in rivers and GW tends to increase downstream of the district, where artificial surfaces and agriculture are concentrated. The total NO3- load to Jucar RBD rivers was estimated at 10,202 tN/year (239 kg/km(2)/year), from which 99% is generated by diffuse pollution, and 3378 tN/year (79 kg/km(2)/year) is discharged into the Mediterranean Sea. Changes in nitrate concentration in the RBD rivers are strongly related to the source of irrigation water, river-aquifer interactions, and flow regulation. The models used in this paper allow the identification of pollution sources, the forecasting of nitrate concentration in surface and groundwater, and the evaluation of the efficiency of measures to prevent water degradation, among other applications.
- Published
- 2021
233. Low-Computational-Cost Hybrid FEM-Analytical Induction Machine Model for the Diagnosis of Rotor Eccentricity, Based on Sparse Identification Techniques and Trigonometric Interpolation
- Abstract
[EN] Since it is not efficient to physically study many machine failures, models of faulty induction machines (IMs) have attracted a rising interest. These models must be accurate enough to include fault effects and must be computed with relatively low resources to reproduce different fault scenarios. Moreover, they should run in real time to develop online condition-monitoring (CM) systems. Hybrid finite element method (FEM)-analytical models have been recently proposed for fault diagnosis purposes since they keep good accuracy, which is widely accepted, and they can run in real-time simulators. However, these models still require the full simulation of the FEM model to compute the parameters of the analytical model for each faulty scenario with its corresponding computing needs. To address these drawbacks (large computing power and memory resources requirements) this paper proposes sparse identification techniques in combination with the trigonometric interpolation polynomial for the computation of IM model parameters. The proposed model keeps accuracy similar to a FEM model at a much lower computational effort, which could contribute to the development and to the testing of condition-monitoring systems. This approach has been applied to develop an IM model under static eccentricity conditions, but this may extend to other fault types.
- Published
- 2021
234. Memorizing Schroder's Method as an Efficient Strategy for Estimating Roots of Unknown Multiplicity
- Abstract
[EN] In this paper, we propose, to the best of our knowledge, the first iterative scheme with memory for finding roots whose multiplicity is unknown existing in the literature. It improves the efficiency of a similar procedure without memory due to Schroder and can be considered as a seed to generate higher order methods with similar characteristics. Once its order of convergence is studied, its stability is analyzed showing its good properties, and it is compared numerically in terms of their basins of attraction with similar schemes without memory for finding multiple roots.
- Published
- 2021
235. Decarbonization of Distribution Transformers Based on Current Reduction: Economic and Environmental Impacts
- Abstract
[EN] Well-known industrial practice efficiency improvement techniques, such as reactive compensation, load balancing, and harmonic filtering, are used in this paper to reduce energy losses in distribution transformers, and therefore, to decrease carbon dioxide emissions and economic costs in the operation of these transformers. Load balancing is carried out by monitoring the values of the angles of the active and reactive components of the vector unbalanced power. Likewise, the application of Order 3/2020 of the Spanish National Markets and Competition Commission is described, in detail, for the calculation of the economic costs derived from the transformer energy losses caused by the load currents and the penalties due to transformer energy deliveries with capacitive power factors. Finally, all these improvement techniques are applied to determine savings in carbon dioxide emissions and costs on the electricity bill of an actual 1000 kVA distribution transformer that supplies a commercial and night-entertainment area. The results of this application case reveal that cost reductions due to energy loss savings are modest, but the reduction in carbon dioxide emissions and the savings in penalties for capacitive reactive supplies are significant.
- Published
- 2021
236. A Review of Techniques Used for Induction Machine Fault Modelling
- Abstract
[EN] Over the years, induction machines (IMs) have become key components in industry applications as mechanical power sources (working as motors) as well as electrical power sources (working as generators). Unexpected breakdowns in these components can lead to unscheduled down time and consequently to large economic losses. As breakdown of IMs for failure study is not economically feasible, several IM computer models under faulty conditions have been developed to investigate the characteristics of faulty machines and have allowed reducing the number of destructive tests. This paper provides a review of the available techniques for faulty IMs modelling. These models can be categorised as models based on electrical circuits, on magnetic circuits, models based on numerical methods and the recently proposed in the technical literature hybrid models or models based on finite element method (FEM) analytical techniques. A general description of each type of model is given with its main benefits and drawbacks in terms of accuracy, running times and ability to reproduce a given fault
- Published
- 2021
237. Minimizing Shadow Area in Mountain Roads for Improving the Sustainability of Infrastructures
- Abstract
[EN] The lack of sunlight on mountain roads in the wintertime leads to an increase in accidents. In this paper, a methodology is presented for the use of sunny and shady areas to be included as a parameter in road design. The inclusion of this parameter allows for the design of an iterative method for the projected infrastructures. The parameterization of the road layout facilitates the possibility of applying an iterative process of modifying the geometric elements that constitute it, examining different layout alternatives until a layout is achieved in which the surface area in the shady area is minimized, increasing the road safety and minimizing environmental impact. The methodology has been defined, generating and analyzing the results of the solar lighting study using a file in IFC format capable of integrating with the rest of the design elements (platform, signaling, structures, etc.) and thus obtaining a BIM format which allows the model to be viewed in three dimensions and moves towards 4D and 5D. The model used for the study was a high mountain road located in the province of Teruel (Spain). It is a road section characterized by successive curves in which several traffic accidents have occurred due to running off the road, partly because of the presence of ice on the platform.
- Published
- 2021
238. Exploring the critical barriers to the implementation of renewable technologies in existing univeristy buildings
- Abstract
[EN] For more than a decade, the European Union has been implementing an ambitious energy policy focused on reducing CO2 emissions, increasing the use of renewable energy and improving energy efficiency. This paper investigates the factors that hinder the application of renewable energy technologies (RETs) in existing university buildings in Spain and Portugal. Following a qualitative methodology, 33 technicians working in the infrastructure management offices of 24 universities have been interviewed. The factors identified have been classified into economic-financial, administrative and legislative barriers, architectural, urban planning, technological, networking, social acceptance, institutional and others. It is concluded that there have not been sufficient economic incentives to carry out RETs projects in this type of building. Conditioning factors can act individually or jointly, generating a greater effect. Most participants consider that there are no social acceptance barriers. Knowledge of these determinants can facilitate actions that help implement this technology on university campuses in both countries.
- Published
- 2021
239. The Role of Value Stream Mapping in Healthcare Services: A Scoping Review
- Abstract
[EN] Lean healthcare aims to manage and improve the processes in the healthcare sector by eliminating everything that adds no value by improving quality of services, ensuring patient safety and facilitating health professionals' work to achieve a flexible and reliable organization. Value Stream Mapping (VSM) is considered the starting point of any lean implementation. Some papers report applications of VSM in healthcare services, but there has been less attention paid to their contribution on sustainability indicators. The purpose of this work is to analyze the role of VSM in this context. To do so, a scoping review of works from recent years (2015 to 2019) was done. The results show that most applications of VSM reported are in the tertiary level of care, and the United States of America (USA) is the country which leads most of the applications published. In relation with the development of VSM, a heterogeneity in the maps and the sustainability indicators is remarkable. Moreover, only operational and social sustainability indicators are commonly included. We can conclude that more standardization is required in the development of the VSM in the healthcare sector, also including the environmental indicators.
- Published
- 2021
240. Design of Pumping Stations Using a Multicriteria Analysis and the Application of the AHP Method
- Abstract
[EN] The pumping station are very important hydraulic system in urban water supply be-cause the pumps raise the water head ensuring the minimum pressure required in drinking water systems. In the design of a pumping station, one of the most important criteria is the number of pumps. However, in the traditional design this criterion is de-fined arbitrarily. The other criteria are defined from the number of pumps and can be produce a design not optimal. In addition, the traditional design does not consider the environment importance to choose the pumps. The objective of this paper is defining a new design methodology for pumping sta-tions. It has been developed using a multicriteria analysis in which nine criteria are evaluated. The application of the analytic hierarchy process (AHP) allows finding an optimal solution. These design criteria have been associated in three cluster factors: technical factors, environmental factors, and economic factors. The results obtained allow not only to validate the methodology, but also to offer a solution to the problem of determining the most suitable model and the number of pumps of a pumping sta-tion.
- Published
- 2021
241. Global Spaces for Local Politics: An Exploratory Analysis of Facebook Ads in Spanish Election Campaigns
- Abstract
[EN] Sponsored content on Facebook has become an indispensable tool for implementing political campaign strategies. However, in political communication research, this channel is still unexplored due to its advertising model in which only target audiences are exposed to sponsored content. The launching of the Facebook Ad Library in May 2018 can be considered a turning point in this regard, inasmuch as it now offers users direct access to ads paid for by political parties, among other advertisers. This paper analyzes some aspects of the strategies implemented by six national parties during the campaigns running up to the two general elections held in Spain in 2019, by performing an analysis on a corpus of 14,684 ads downloaded directly from the Facebook Ad Library. It also provides evidence of the different emphasis placed by the parties on sponsored content. For its part, an analysis of ad scheduling shows how the publishing of ads was stepped up as polling day approached, while also revealing the practice of posting political content way in advance of election campaigns.
- Published
- 2021
242. Life Cycle Assessment of Bridges Using Bayesian Networks and Fuzzy Mathematics
- Abstract
[EN] At present, reducing the impact of the construction industry on the environment is the key to achieving sustainable development. Countries all over the world are using software systems for bridge environmental impact assessment. However, due to the complexity and discreteness of environmental factors in the construction industry, they are difficult to update and determine quickly, and there is a phenomenon of data missing in the database. Most of the lost data are optimized by Monte Carlo simulation, which greatly reduces the reliability and accuracy of the research results. This paper uses Bayesian advanced fuzzy mathematics theory to solve this problem. In the research, a Bayesian fuzzy mathematics evaluation and a multi-level sensitivity priority discrimination model are established, and the weights and membership degrees of influencing factors were defined to achieve comprehensive coverage of influencing factors. With the support of theoretical modelling, software analysis and fuzzy mathematics theory are used to comprehensively evaluate all the influencing factors of the five influencing stages in the entire life cycle of the bridge structure. The results show that the material manufacturing, maintenance, and operation of the bridge still produce environmental pollution; the main source of the emissions exceeds 53% of the total emissions. The effective impact factor reaches 3.01. At the end of the article, a big data sensitivity model was established. Through big data innovation and optimization analysis, traffic pollution emissions were reduced by 330 tonnes. Modeling of the comprehensive research model; application; clearly confirms the effectiveness and practicality of the Bayesian network fuzzy number comprehensive evaluation model in dealing with uncertain factors in the evaluation of the sustainable development of the construction industry. The research results have made important contributions to the realization of the sustainable development goals
- Published
- 2021
243. Effects of Climate Change on Water Quality in the Jucar River Basin (Spain)
- Abstract
[EN] The Mediterranean region is a climate change hotspot, especially concerning issues of hydrological planning and urban water supply systems. In this context, the Jucar River Basin (Spain) presents an increase of frequency, intensity and duration of extreme meteorological phenomena, such as torrential rains, droughts or heat waves, which directly affect the quantity and quality of raw water available for drinking. This paper aims to analyze the effects of climate change on the raw water quality of the Jucar River Basin District, which mainly supplies the city of Valencia and its metropolitan area, in order to adapt drinking water treatments to new conditions and opportunities. For this purpose, we used observed data of water quality parameters from four stations and climate drivers from seven Earth system models of the latest Coupled Model Intercomparison Project-Phase 6. To model water quality (turbidity and conductivity) in the past and future scenarios, this study employs a backward stepwise regression taking into account daily values of mean temperature, maximum temperature, total rainfall and minimum and maximum relative humidity. Results showed that the model performance of the water quality simulation is more adequate for short moving-average windows (about 2-7 days) for turbidity and longer windows (about 30-60 days) for conductivity. Concerning the future scenarios, the most significant change was found in the projected increase of conductivity for the station of the Jucar river, between 4 and 11% by 2100, respectively, under the medium (SSP2-4.5) and pessimistic (SSP5-8.5) emission scenarios. The joint use of these types of management and monitoring tools may help the managers in charge of carrying out the different water treatments needed to apply a better plan to raw water and may help them identify future threats and investment needs to adapt the urban water supply systems to the changing conditions of raw water, such as turbidity or conductivity, as
- Published
- 2021
244. Development of Driving Simulation Scenarios Based on Building Information Modeling (BIM) for Road Safety Analysis
- Abstract
[EN] The analysis of road safety is critical in road design. Complying to guidelines is not enough to ensure the highest safety levels, so many of them encourage designers to virtually recreate and test their roads, benefitting from the evolution of driving simulators in recent years. However, an accurate recreation of the road and its environment represents a real bottleneck in the process. A very important limitation lies in the diversity of input data, from different sources and requiring specific adaptations for every single simulator. This paper aims at showing a framework for recreating faster virtual scenarios by using an Industry Foundation Classes (IFC)-based file. This methodology was compared to two other conventional methods for developing driving scenarios. The main outcome of this study has demonstrated that with a data exchange file in IFC format, virtual scenarios can be faster designed to carry out safety audits with driving simulators. As a result, the editing, programming, and processing times were substantially reduced using the proposed IFC exchange file format through a BIM (Building Information Modeling) model. This methodology facilitates cost-savings, execution, and optimization resources in road safety analysis.
- Published
- 2021
245. Effect on Procrastination and Learning of Mistakes in the Design of the Formative and Summative Assessments - A Case Study
- Abstract
[EN] The design of the formative and summative assessment processes is of paramount importance to help students avoid procrastination and guide them towards the achievement of the learning objectives that are described in the course syllabus. If the assessment processes are poorly designed the outcome can be disappointing, including high grades but poor learning. In this paper, we describe the unexpected and undesirable effects that an on-demand formative assessment and the timetable of a summative assessment that left the most cognitively demanding part, problem-solving, to the end of the course, had on the behavior of students and on both grading and learning. As the formative assessment was voluntary, students procrastinated till the last minute. However, the real problem was that due to the design of the summative assessment, they focused their efforts mainly on the easiest parts of the summative assessment, passing the course with ease, but achieving a low learning level, as evidenced by the low scores of the problem-solving part of the summative assessment.
- Published
- 2021
246. Collaborative Distributed Planning with Asymmetric Information. A Technological Driver for Sustainable Development
- Abstract
[EN] The growing interest in sustainable development is reflected in both the market's sensitivity to environmental and social issues and companies' interest in the opportunities that sustainable development objectives provide. SMEs, which account for most of the world's pollution, have significant resource constraints for a sustainable development. Sharing their scarce resources can help them to overcome these constraints and to gain agility and organisational resilience against uncertainties, but the distrust inherent in belonging to different companies prevents them from sharing the necessary information for coordination purposes. This paper presents a coordination mechanism proposal with information asymmetry to allow independent companies' resources to be sustainably shared as a technological driver. The proposed distributed coordination mechanism is compared to both a decentralised-uncoordinated and a centralised situation. The interest of the proposal is evaluated by a computer simulation experiment employing mathematical programming models with independent objectives in the Generic Materials and Operations Planning formulation with a rolling horizon procedure in different demand, uncertainty and product scenarios. Competitive improvement is identified for all members for their excess capacity use and their operations planning.
- Published
- 2021
247. Bridging the Gap between Landscape and Management within Marinas: A Review
- Abstract
[EN] Marinas are known to be features related to nautical tourism. Nevertheless, the responsibility of managers does not lie solely on providing accurate services to boats, seafarers and visitors. Thus, an effective management should include other factors, because marinas are embodied in a singular space, with links to diverse nature. Landscape, known as the relationship between people and their environment, represents a set of these links. In this paper, we attempt to delve into the marina management and landscape. Firstly, a targeted exploration of the main issues related to the management of marinas was accomplished. Secondly, based on the previous items, a screening was carried out from a landscape viewpoint with the aim to stablish which elements of marina's management are significant when tackling landscape. The results indicated that there is a concern with environmental aspects, specifically, on issues related to marine pollution and water quality. However, the determination of the main management-related issues, valued from a landscape perspective, may provide the main issues that need to be addressed in decision-making processes, incorporating the landscape dimension. Thus, we have attempted to understand and discuss how the landscape should be considered in marina management as a potential competitive advantage.
- Published
- 2021
248. Comparative Life Cycle Analysis of Concrete and Composite Bridges Varying Steel Recycling Ratio
- Abstract
[EN] Achieving sustainability is currently one of the main objectives, so a consensus between different environmental, social, and economic aspects is necessary. The construction sector is one of the main sectors responsible for environmental impacts worldwide. This paper proposes the life cycle assessment (LCA) and comparison of four bridge deck alternatives for different span lengths to determine which ones are the most sustainable solutions. The ReCiPe method is used to conduct the life cycle analysis, by means of which the impact value is obtained for every alternative and span length. The Ecoinvent 3.3 database has been used. The life cycle has been divided into four phases: manufacturing, construction, use and maintenance, and end of life. The associated uncertainties are considered, and the results are shown in both midpoint and endpoint approaches. The results of our research show that for span lengths less than 17 m, the best alternative is the prestressed concrete solid slab. For span lengths between 17 and 25 m, since the box-girder solution is not used, then the prestressed concrete lightened slab is the best alternative. For span lengths between 25 and 40 m, the best solution depends on the percentage of recycled structural steel. If this percentage is greater than 90%, then the best alternative is the composite box-girder bridge deck. However, if the percentage is lower, the cleanest alternative is the prestressed concrete box-girder deck. Therefore, the results show the importance of recycling and reusing structural steel in bridge deck designs.
- Published
- 2021
249. Building a Theoretical Framework for Corporate Sustainability
- Abstract
[EN] Literature about sustainability and sustainable businesses has become a large field of study during the last years. This field is growing so fast that there are sub-areas or bodies of literature within the sustainability which scopes with clear boundaries between each other. This has caused the apparition of several methodologies and tools for turning traditional companies into sustainable business models. This paper aims to develop the descriptive stage of the theory building process through a careful review of literature to create the first phase of a theory about corporate sustainability. It provides the following classification of concepts retrieved from the observation of the state of art: holistic sustainability, sustainable business models, sustainable methodologies, sustainable operations, and sustainability-oriented innovation. In addition, it seeks to establish relationships between the sustainable concepts and the expected outcomes that their implementation can generate among companies and organizations. Finally, it gives an overview of possibilities for managers that want to embed sustainability in their firms and clear paths of research for keeping the building of the theory about corporate sustainability as a process of constant iteration and improvement.
- Published
- 2021
250. Optimized Application of Sustainable Development Strategy in International Engineering Project Management
- Abstract
[EN] The aim of this paper is to establish an international framework for sustainable project management in engineering, to make up the lack of research in this field, and to propose a scientific theoretical basis for the establishment of a new project management system. The article adopts literature review, mathematical programming algorithm and case study as the research method. The literature review applied the visual clustering research method and analyzed the results of 21-year research in this field. As a result, the project management system was found to have defects and deficiencies. A mathematical model was established to analyze the composition and elements of the optimized international project management system. The case study research selected large bridges for analysis and verified the superiority and practicability of the theoretical system. Thus, the goal of sustainable development of bridges was achieved. The value of this re-search lies in establishing a comprehensive international project management system model; truly integrating sustainable development with project management; providing new research frames and management models to promote the sustainable development of the construction industry.
- Published
- 2021
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