170,564 research outputs found
Land Suitability Assessment for Potato Cultivation in an Italian Region: a GIS Based Analysis
No full textThe knowledge of soil characteristics and climate conditions is of primary importance for choosing the production techniques more suitable for improving crop yields. Through methods that include the use of georeferenced information (weather, soil, etc.) and GIS (Geographical Information Systems), the environmental characteristics can be properly analyzed, crop requirements compared and type and degree of land suitability identified in relation to product yields.
In potato cultivation the performances and qualitative aspects are both closely linked to environmental factors. In particular, crop profitability is influenced by soil texture, pH, organic matter content and climatic factors such as water availability and temperatures.
The chapter presents a methodology to evaluate the suitability of some areas of Emilia Romagna Region, characterized by high quality production or by high production potential.
In order to demonstrate the validity of the methodology, a GIS analysis was conducted to evaluate the actual potato crop distribution compared with a suitability map derived from land evaluation.
The results provide some guidelines for planning and management of potato cultivation in the Region
[Ludovico Antonio, Bianca and Carlo Caprara (c.1817), funerary sculpture]
No full textFrom Berresford: Ludovico Antonio, Bianca and Carlo Caprara (c.1817), Giacomo de Maria, Cimitero della Certosa, Bologna.Woman carrying urn, angel.Title from Berresford
The Ancient Romans’ Route to Charge Density Waves in Cuprates
No full textAn account is given of the main steps that led the research group in Rome, to which the author belongs, to the formulation of the charge-density-wave scenario for high-T-c superconducting cuprates. The early finding of the generic tendency of strongly correlated electron systems with short range interactions to undergo electron phase separation was subsequently contrasted with the homogenizing effect of the long-range Coulomb interaction. The two effects can find a compromise in the formation of incommensurate charge density waves. These charge density waves are inherently dynamical and are overdamped as a consequence of the possibility to decay in electron-hole pairs, yet tend to maintain a (quantum) critical character, which is mirrored in their marked momentum and frequency dependence and in their strong variation with temperature and doping. These dynamical incommensurate charge density waves act as mediators of pairing lading to high-T-c superconductivity, and provide the scattering mechanism that produces the observed violation of the Fermi-liquid paradigm in the metallic phase
Applicazione delle metodologie statistiche: l'analisi fattoriale secondo la tecnica Q e la Cluster analysis sui factor loadings
No full textLe determinanti personali dell’Ego-resiliency negli adolescenti (Personal determinants of Ego-resiliency in adolescence).
No full textDecorous lower bounds for minimum linear arrangement
No full textMinimum Linear Arrangement is a classical basic combinatorial optimization problem from the 1960s, which turns out to be extremely challenging in practice. In particular, for most of its benchmark instances, even the order of magnitude of the optimal solution value is unknown, as testified by the surveys on the problem that contain tables in which the best known solution value often has one more digit than the best known lower bound value. In this paper, we propose a linear-programming based approach to compute lower bounds on the optimum. This allows us, for the first time, to show that the best known solutions are indeed not far from optimal for most of the benchmark instances
Longitudinal and reciprocal relations between adolescents' prosocial behavior, peer acceptance, self-efficacy beliefs and academic achievement
No full textA limited number of studies has found that Prosocial Behavior (PB; i.e. voluntary actions aimed to benefit others, like helping, consoling, donating; Eisenberg, et al., 2006) was associated with academic achievement across adolescence (e.g., Gerbino et al., 2018; Wentzel, 1993). It was hypothesized that prosocial adolescents may be more motivated and engaged with school, because they experience a supportive and accepting environment (e.g., Jennings & Greenberg 2009). Similarly, Self-efficacy in Self-Regulated learning (SE-SRL; perceived capacities in self-monitoring, in setting goals and using self-motivational strategies for learning) is crucial for students' motivation and persistence (Bandura, 1997). Our study is aimed to identify the unique role of PB and Peer Acceptance (PA) in supporting SE-SRL and School Grades (SG) across middle school. We hypothesized that positive benefits of PB in supporting PA and SG may be accumulated over time through the repetitive interactions with peers. We also expect that PA contribute to SE-SRL and SG.
We analyzed reciprocal relations between PB, PA and SE-SRL and Grades across middle school years. Participants were 450 adolescents (48.5% boys; mean age = 12) attending at T1 6th grade of junior high school. Participants were drawn from the Genzano Longitudinal Study. PB was assessed by peer nominations (Caprara & Pastorelli, 1993). SE-SRL was evaluated through 11 self-reported items (Caprara et al., 2008), peer acceptance was measured using peer nomination. School grades were reported by teachers.
We tested a full cross lagged model, using structural equation modelling. Main results showed that 6th and 7th grade Peer Acceptance sustained later Self-Efficacy beliefs and Academic Grades. Differently, PB contributed to social acceptance, academic self-efficacy and school grades, only from 7th to 8th grades. Our study underlined that being prosocial, as well as, being accepted by peers, have a unique role in supporting adolescents’ successful school experience
Longitudinal and reciprocal relations between adolescents' prosocial behavior, peer acceptance, self-efficacy beliefs and academic achievement
No full textA limited number of studies has found that Prosocial Behavior (PB; i.e. voluntary actions aimed to benefit others, like helping, consoling, donating; Eisenberg, et al., 2006) was associated with academic achievement across adolescence (e.g., Gerbino et al., 2018; Wentzel, 1993). It was hypothesized that prosocial adolescents may be more motivated and engaged with school, because they experience a supportive and accepting environment (e.g., Jennings & Greenberg 2009). Similarly, Self-efficacy in Self-Regulated learning (SE-SRL; perceived capacities in self-monitoring, in setting goals and using self-motivational strategies for learning) is crucial for students' motivation and persistence (Bandura, 1997). Our study is aimed to identify the unique role of PB and Peer Acceptance (PA) in supporting SE-SRL and School Grades (SG) across middle school. We hypothesized that positive benefits of PB in supporting PA and SG may be accumulated over time through the repetitive interactions with peers. We also expect that PA contribute to SE-SRL and SG. We analyzed reciprocal relations between PB, PA and SE-SRL and Grades across middle school years. Participants were 450 adolescents (48.5% boys; mean age = 12) attending at T1 6th grade of junior high school. Participants were drawn from the Genzano Longitudinal Study. PB was assessed by peer nominations (Caprara & Pastorelli, 1993). SE-SRL was evaluated through 11 self-reported items (Caprara et al., 2008), peer acceptance was measured using peer nomination. School grades were reported by teachers. We tested a full cross lagged model, using structural equation modelling. Main results showed that 6th and 7th grade Peer Acceptance sustained later Self-Efficacy beliefs and Academic Grades. Differently, PB contributed to social acceptance, academic self-efficacy and school grades, only from 7th to 8th grades. Our study underlined that being prosocial, as well as, being accepted by peers, have a unique role in supporting adolescents’ successful school experience
Measuring the stresses transmitted during mechanical grape harvesting.
No full textThe objective was to evaluate the stresses transmitted by machinery during the harvest of grapes that affect the productivity and quality of the work. The evaluation was carried out on two commercial grape harvesters, from the same manufacture, one self-propelled and the other trailed, which differed in the apparatus for detaching, intercepting and handling the product. Each machine was operated to provide the best operating conditions. Measurements of harvest quality, accelerations inside the machines, and accelerations on the plant were carried out. Harvest quality was evaluated by checking the condition of the detached grapes, level of plant defoliation and amount of visible losses. Accelerations inside the machine were evaluated using an instrumented sphere inserted in the product flow during harvesting. Accelerations on the plant were evaluated at the moment of grape detachment, measuring the stresses transmitted by the beating system with accelerometers positioned on the vine shoots.
The results obtained indicate that the productivity of the two machines differed (+50% for the self-propelled), using a comparable work quality. From a preliminary analysis of the action of the beaters on the plants, the two grape harvesters differed in their duration and intensity of the stresses. A more detailed dynamic analysis, considering the Doppler effect and an evaluation of the harmonics obtained with spectral decomposition by means of FFT (Fast Fourier Transform), demonstrated a better energy performance for the self-propelled machine that explained its higher work efficiency
New techniques for cost sharing in combinatorial optimization games
No full textCombinatorial optimization games form an important subclass of cooperative games. In recent years, increased attention has been given to the issue of finding good cost shares for such games. In this paper, we define a very general class of games, called integer minimization games, which includes the combinatorial optimization games in the literature as special cases. We then present new techniques, based on row and column generation, for computing good cost shares for these games. To illustrate the power of these techniques, we apply them to traveling salesman and vehicle routing games. Our results generalize and unify several results in the literature. The main underlying idea is that suitable valid inequalities for the associated combinatorial optimization problems can be used to derive improved cost shares
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