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Recent Submissions

Influence of individual versus collaborative peer assessment on score accuracy and learning outcomes in higher education: an empirical study
(Taylor and Francis, 2021) Rico-juan , Juan-ramón; Cachero , Cristina; Macia Soler, Hermenegilda
Maximising the accuracy and learning of self and peer assessment activities in higher education requires instructors to make several design decisions, including whether the assessment process should be individual or collaborative, and, if collaborative, determining the number of members of each peer assessment team. In order to support this decision, a quasi-experiment was carried out in which 82 first-year students used three peer assessment modalities. A total of 1574 assessments were obtained. The accuracy of both the students’ self-assessment and their peer assessment was measured. Results show that students’ self-assessment significantly improved when groups of three were used, provided that those with the 20% poorest performances were excluded from the analysis. This suggests that collaborative peer assessment improves learning. Peer assessment scores were more accurate than self-assessment, regardless of the modality, and the accuracy improved with the number of assessments received. Instructors need to consider the trade-off between students’ improved understanding, which favours peer assessment using groups of three, and a higher number of assessments, which, under time constraints, favours individual peer assessment.
A stochastic thermo-economic analysis of solar domestic hot-water systems in compliance with building energy code requirements: The case of Spain
(Elsevier, 2022-01-29) Belmonte Toledo, Juan Francisco; Ramírez Fernández, Francisco Javier; Almendros Ibáñez, José Antonio
Spanish residential buildings typically cover the required domestic hot-water renewable fraction regulated by building codes using solar thermal systems, typically through solutions based on flat-plate collectors and water storage tanks. For medium or large buildings (with high domestic hot-water demands), the energy savings produced by the solar system operation easily exceed the owning, operating, and maintenance costs, with its installation being highly advantageous under current energy prices. However, this situation is much less clear when small residential buildings are taken into consideration, as energy savings produced by solar domestic hot-water systems may not be sufficiently large to compensate for those costs, often operating below economically feasible levels. The energy savings associated with the operation of the solar systems were estimated using the simulation tool TRNSYS, using its output results as input data to conduct two different economic feasibility assessments (based on deterministic, and stochastic approaches). The deterministic analysis revealed that solar DHW-systems installed in small buildings with fewer than 5 apartments are not economically feasible. The stochastic economic analysis identified a wide probability range (between 70 and 90% of all the simulated cases) for economically feasible solar domestic hot-water systems, when they serve buildings with more than 48 apartments.
Exploiting variability in the design of genetic algorithms to generate telerehabilitation activities
(Elsevier, 2022-01-13) Moya Moya, Alejandro; Navarro Martínez, Elena María; Jaén, Javier; López Jaquero, Víctor Manuel; Capilla, Rafael
The increasing number of people with impairments and the lack of specialists has led to a loss of efficiency to deliver proper treatments from National healthcare systems. In this light, telerehabilitation can play an important role as patients can perform certain therapies at home. Consequently, telerehabilitation systems must support delivering bespoke therapies to patients tailored to their deficits and preferences. However, creating bespoke telerehabilitation activities is a complex and time-consuming task because of the great assortment of deficits. To address this problem, we propose in this research work an automatic generation of such telerehabilitation activities aiming to both assist the specialist in designing and creating telerehabilitation activities that best fit each patient’s needs. Therefore, the main contributions of this paper are: (1) the exploitation of Feature Models (FM) to describe the variability in the telerehabilitation domain and to facilitate the communication among the stakeholders to accurately specify the patients’ deficits and the features of an association telerehabilitation activity. (2) The design and development of a genetic algorithm (GA) relying on the specified FM able to generate customized association telerehabilitation activities. The FM specified describes precisely the search problem so that the GA chromosomes can be easily identified. It also facilitates the discussion with the stakeholders during the design of the algorithm since its specification can be understood by non-experts in Computer Science. (3) The evaluation of the effectiveness and efficiency of the GA developed by using two sets of experiments: one for tuning the parameters of the GA and another to assess the effectiveness and efficiency of the algorithm while stressed under constraining conditions. (4) The integration of the proposal with a tool for telerehabilitation of people with Acquired Brain Injury (ABI). The proposal targets people with ABI because of the wide assortment of deficits they present, as well as the high impact ABI is having on society, being currently more common than breast cancer, spinal cord injury, HIV/AIDS and multiple sclerosis (MS) combined.
Environmental challenges related to cyanidation in Central American gold mining; the Remance mine (Panama)
(Elsevier, 2021-10-27) González Valoys, Ana Cristina; Arrocha, Jonatha; Monteza Destro, Tisla; Vargas Lombardo, Miguel; Esbrí Víctor, José María; García Ordiales, Efrén; Jiménez Ballesta, Raimundo; García Navarro, Francisco Jesús; Higueras Higueras, Pablo León
Mine tailings are a potential source of environmental pollution because they typically contain potentially toxic elements (PTEs) and the residue of chemical compounds used during extraction processes. The Remance gold mine (NW Panama) is a decommissioned mine with mining activity records dating from the 1800s and several periods of abandonment. Very little remediation work has been performed, and waste is exposed to climatic conditions. This study aimed to evaluate the PTEs and cyanide contents in mine waste after mining operations ceased some 20 years ago, and to evaluate the degree of pollution and the environmental risks they pose with the use of the Pollution Load Index (PLI) and the Ecological Risk Index (RI). Although the total cyanide (T-CN) concentration (1.4–1.9 mg kg−1) found in most of the study area falls within the limits of gold mining tailing values for American sites (1.5–23 mg kg−1), it is worth noting that the values of the tailings of the last used mining operation exceed it (25.2–518 mg kg−1) and persist at the site. The PLI and RI suggest that the tailings from the mine and mine gallery sediments represent a source of pollution for soils and surrounding areas given their high content of PTEs (As, Cu, Sb, Hg) and T-CN, which pose serious ecological risks for biota. Therefore, it is necessary to draw up a remediation plan for this area.