1,032 research outputs found
Preassociative aggregation functions
The classical property of associativity is very often considered in
aggregation function theory and fuzzy logic. In this paper we provide
axiomatizations of various classes of preassociative functions, where
preassociativity is a generalization of associativity recently introduced by
the authors. These axiomatizations are based on existing characterizations of
some noteworthy classes of associative operations, such as the class of
Acz\'elian semigroups and the class of t-norms.Comment: arXiv admin note: text overlap with arXiv:1309.730
The challenges and possibilities of reflective learning in higher education. Research focused from the perspective of university students on four different degree courses
Despite an increase in university teaching practices based on reflective learning methodology (RL),
only very few studies are found in the context of higher education aimed at determining students?
perception of this approach to teaching and learning. The aim of this research was to ascertain the
opinions of students on different university degree courses regarding the challenges, difficulties and
contributions arising from the application of reflective learning methodology in their learning process
so as to propose strategies for improving education. The study was carried out on four Bachelor
degree courses at the University of Girona: Social Education, Environmental Sciences, Nursing and
Psychology.
The research was conducted in two stages. In the first (2011-12 academic year), a questionnaire was
administered to 162 students (43 from Social Education; 33 from Environmental Sciences; 31 from
Nursing; and 55 from Psychology). One section of the questionnaire was specifically devoted to
studying the perceptions of students participating in various RL experiences regarding the main
difficulties they faced and the contributions of the RL to their learning process. Among the highlighted
difficulties was the fact that RL requires a work process they are not used to and their lack of reflective
writing skills. Among the contributions, the students felt that RL results in more complex and selfregulated
knowledge, develops greater dynamic capabilities and increases the degree of reflection on
learning processes and areas for improvement. In the second stage of the study (2012-13 academic
year), four focus groups were held with students who had participated in the previous years?
experience with the aim of gaining further insight into their perceptions regarding the challenges and
contributions of RL. A total of 20 students participated, all of whom gave informed written consent. The
sessions were recorded and transcribed in full and a thematic content analysis was performed. In all
four groups the students stated that the experience had allowed them to improve their learning and
become aware of their current situation and areas for improvement. As for the challenges, they cited
difficulties in understanding the aims and purpose of RL, particularly at the beginning of the
experience, together with problems experienced in writing about it, doubts about the level of openness
required and uncertainty about how they would be assessed.
The research conducted suggested that RL has significant potential to connect academic activity with
professional action. It also provided working guidelines for improving experiences carried out on the
basis of RL. These include the need to clarify the methodology and present arguments for its use, so
that students understand the type of work it will mean for them and the objectives they pursued.
Students should also be provided with sufficiently clear guidelines regarding how they will be
assessed (in relation to both activities and level of reflection). There is a need to build a group climate
based on mutual trust, continuous feedback and the establishment of a support process that maintains
this trust throughout the learning process
Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems
The objective of this paper is to model the dynamics and validate the results of nitrous oxide (N2O) emissions from three Swedish nitrifying/denitrifying, nitritation and anammox systems treating real anaerobic digester sludge liquor. The Activated Sludge Model No. 1 is extended to describe N2O production by both heterotrophic and autotrophic denitrification. In addition, mass transfer equations are implemented to characterize the dynamics of N2O in the water and the gas phases. The biochemical model is simulated and validated for two hydraulic patterns: (1) a sequencing batch reactor; and (2) a moving-bed biofilm reactor. Results show that the calibrated model is partly capable of reproducing the behaviour of N2O as well as the nitritation/nitrification/denitrification dynamics. However, the results emphasize that additional work is required before N2O emissions from sludge liquor treatment plants can be generally predicted with high certainty by simulations. Continued efforts should focus on determining the switching conditions for different N2O formation pathways and, if full-scale data are used, more detailed modelling of the measurement devices might improve the conclusions that can be drawn.</jats:p
Modulation of the electronic properties of GaN films by surface acoustic waves
We report on the interaction between photogenerated electron-hole pairs and surface acoustic waves (SAW) in GaN films grown on sapphire substrates. The spatial separation of photogenerated carriers by the piezoelectric field of the SAW is evidenced by the quenching of the photoluminescence (PL) intensity. The quenching levels in GaN are significantly smaller than those measured in GaAs under similar conditions. The latter is attributed to the lower exciton ionization efficiency and carrier separation probabilities mediated by the piezoelectric effect. The PL spectra also evidence energy shifts and broadenings of the electronic transitions, which are attributed to the band gap modulation by the SAW strain [email protected]
Urban environment soundscape evaluation: Milan case study of noise events perceptions by citizens
As one of the main urban environmental pollutants, noise is becoming a real public health concern due to its impact on citizen's well-being. Real-operation noise monitoring can help policy makers in improving the quality of urban environments. To this end, Wireless Acoustic Sensor Networks (WASNs) have been deployed in crowded city centers in both America and Europe. The main application of WASNs is to measure the noise levels from road traffic. Yet, other types of sounds can be found in urban areas, which may also affect citizen's health. Here, we aim to evaluate the citizen's perception of different urban sounds considering their psychoacoustic characteristics, namely loudness, sharpness, roughness, fluctuation strength and tonality. To this end, we have conducted an on-line and off-site listening test using a urban acoustic event dataset collected by WASNs in Milan. The dataset includes seven common urban noises such as sirens, horns, people talking, truck, works, among others. Participants have been asked to rate the level of agreement with adjectives such as loud, shrilling, disturbing, sharp or pleasant. The test responses from one hundred volunteers allow us to gather valuable information about people's perceptions of common urban noises
Spanish Preanalytical Quality Monitoring Program (SEQC), an overview of 12 years' experience
Preanalytical variables, such as sample collection, handling and transport, may affect patient results. Preanalytical phase quality monitoring should be established in order to minimize laboratory errors and improve patient safety. A retrospective study (2001-2013) of the results obtained through the Spanish Society of Clinical Biochemistry and Molecular Pathology (SEQC) External quality assessment (preanalytical phase) was performed to summarize data regarding the main factors affecting preanalytical phase quality. Our aim was to compare data from 2006 to 2013 with a previously published manuscript assessing the 2001-2005 period. A significant decrease in rejection rates was observed both for blood and urine samples. For serum samples, the most frequent rejection causes in the first period were non-received samples (37.5%), hemolysis (29.3%) and clotted samples (14.4%). Conversely, in the second period, hemolysis was the main rejection cause (36.2%), followed by non-received samples (34.5%) and clotted samples (11.1%). For urine samples, the main rejection cause overall was a non-received sample (up to 86.1% of cases in the second period, and 81.6% in the first). For blood samples with anticoagulant, the number of rejections also decreased. While plasma-citrate-ESR still showed the highest percentages of rejections (0.980% vs. 1.473%, p<0.001), the lowest corresponded to whole-blood EDTA (0.296% vs. 0.381%, p<0.001). For the majority of sample types, a decrease in preanalytical errors was confirmed. Improvements in organization, implementation of standardized procedures in the preanalytical phase, and participation in a Spanish external quality assessment scheme may have notably contributed to error reduction in this phase
- …