1,207 research outputs found
Brakes and barriers of Corporate Volunteering
The objective of this research is to study which are the determinants for the participation of employees in Corporate Volunteer actions -hereafter CV- that can become barriers and brakes, and which ones can mean negative consequences for the company. Ignorance of managers for these programs, about which are those brakes and its relevance, may be behind the low participation fees that companies have in their Corporate Volunteering Programs.For this purpose, we conducted a qualitative empirical study to define a model, based on the motivations and determinants of employee participation in corporate volunteer programs. The methodology that we use in order to advance the understanding of this field is common in the dynamics of so-called Discussion Groups or Focus Group (FG). We believe that this methodological approach fits well with the research question and objectives that guide us in this work, since it will allow the reconstruction of real social situations and to capture the interaction between different discourses.We trust the fact the model proposed really allows advance in knowledge of Corporate Volunteer field, as literature suggested, and we offer a conceptual framework to managers in order to develop CV programs that allows mitigating potential risks and increasing employee participation effectively
Assessment of conductor thermal models for grid studies
: Existing EMS applications resort to static network models built upon constant
resistances whose values are specified beforehand. However, the steady-state thermal balance of
overhead conductors requires that ohmic losses be dissipated by convection and radiation heat,
leading to conductor resistances being a function both of environmental factors and transmitted
current. Each term of the equation involved in the thermal balance of overhead conductors is
analysed allowing the influence of conductor current on conductor temperature to be separated
from that corresponding to environmental factors. As a result, three approximate thermal models
are elaborated, which are compared on the Spanish transmission system. Test cases are included
showing that the influence of the selected model on transmission losses may be significant enough,
particularly when the transmission system spans areas with diverse loading levels and weather
conditions
Time-Series Prediction: Application to the Short-Term Electric Energy Demand
This paper describes a time-series prediction method based on the kNN technique. The proposed methodology is applied to the 24-hour load forecasting problem. Also, based on recorded data, an alternative model is developed by means of a conventional dynamic regression technique, where the parameters are estimated by solving a least squares problem. Finally, results obtained from the application of both techniques to the Spanish transmission system are compared in terms of maximum, average and minimum forecasting errors
Application of Evolutionary Computation Techniques to the Optimal Short-Term Scheduling of the Electrical Energy Production
In this paper, an evolutionary technique applied to the optimal short-term scheduling (24 hours) of the electric energy production is presented. The equations that define the problem lead to a nonlinear mixed-integer programming problem with a high number of real and integer variables. Consequently, the resolution of the problem based on combinatorial methods is rather complex. The required heuristics, introduced to assure the feasibility of the constraints, are analyzed, along with a brief description of the proposed genetic algorithm. Finally, results from realistic cases based on the Spanish power system are reported, revealing the good performance of the proposed algorithm, taking into account the complexity and dimension of the problem
Overload screening of transmission systems using neural networks
The process of determining whether a power system is in a secure or insecure state is a crucial task which must be addressed on-line in any Energy Management System. In this paper, an Artificial Neural Network, capable of accurately identifying the set of harmful contingencies, is presented, along with several results obtained from a real-size power network. The proposed approach makes use of classical numerical techniques to compensate the ANN'S inputs so that it can deal with topological changes in the power system
A Comparison of Two Techniques for Next- Day Electricity Price Forecasting
In the framework of competitive markets, the market’s participants need energy price forecasts in order to determine their optimal bidding strategies and maximize their benefits. Therefore, if generation companies have a good accuracy in forecasting hourly prices they can reduce the risk of over/underestimating the income obtained by selling energy. This paper presents and compares two energy price forecasting tools for day-ahead electricity market: a k Weighted Nearest Neighbours (kWNN) the weights being estimated by a genetic algorithm and a Dynamic Regression (DR). Results from realistic cases based on Spanish electricity market energy price forecasting are reported
Ontologías de dominio y herramientas IIIF: una aproximación al fondo de manuscritos poéticos de la Real Biblioteca
Domain ontologies, specifically RDA and POSTDATA, together with IIIF, are the technologies used for a bibliographical and literary approach to the Royal Library's collection of poetic manuscripts and their online publication in the context of a digital library. Special emphasis is given to aspects related to the study of provenance, such as copy marks or part-whole relationships for the reconstruction of a structurally complex collection, and, outside the bibliographic domain, poetic analysis is also considered.Las ontologías de dominio, en concreto RDA y POSTDATA, junto con IIIF, son las tecnologías utilizadas para una aproximación bibliográfica y literaria a la colección de manuscritos poéticos de la Real Biblioteca y su publicación online en el contexto de una biblioteca digital. Se da especial énfasis a los aspectos relacionados con el estudio de la procedencia, tales como las marcas de ejemplar o las relaciones parte-todo para la reconstrucción de un fondo estructuralmente complejo, y, al margen del dominio bibliográfica, se considera también el análisis poétic
una aproximación al fondo de manuscritos poéticos de la Real Biblioteca
Las ontologías de dominio, en concreto RDA y POSTDATA, junto con IIIF, son las
tecnologías utilizadas para una aproximación bibliográfica y literaria a la colección de
manuscritos poéticos de la Real Biblioteca y su publicación online en el contexto de
una biblioteca digital. Se da especial énfasis a los aspectos relacionados con el estudio
de la procedencia, tales como las marcas de ejemplar o las relaciones parte-todo para
la reconstrucción de un fondo estructuralmente complejo, y, al margen del dominio
bibliográfica, se considera también el análisis poético.Domain ontologies, specifically RDA and POSTDATA, together with IIIF, are the
technologies used for a bibliographical and literary approach to the Royal Library's
collection of poetic manuscripts and their online publication in the context of a digital
library. Special emphasis is given to aspects related to the study of provenance, such
as copy marks or part-whole relationships for the reconstruction of a structurally
complex collection, and, outside the bibliographic domain, poetic analysis is also
considere
Hybrid analog-digital processing system for amplitude-monopulse RSSI-based MiMo wifi direction-of-arrival estimation
We present a cost-effective hybrid analog digital system to estimate the Direction of Arrival (DoA) of WiFi signals. The processing in the analog domain is based on simple wellknown RADAR amplitude monopulse antenna techniques. Then, using the RSSI (Received Signal Strength Indicator) delivered by commercial MiMo WiFi cards, the DoA is estimated using the socalled digital monopulse function. Due to the hybrid analog digital architecture, the digital processing is extremely simple, so that DoA estimation is performed without using IQ data from specific hardware. The simplicity and robustness of the proposed hybrid analog digital MiMo architecture is demonstrated for the ISM 2.45GHz WiFi band. Also, the limitations with respect to multipath effects are studied in detail. As a proof of concept, an array of two MiMo WiFi DoA monopulse readers are distributed to localize the two-dimensional position of WiFi devices. This costeffective hybrid solution can be applied to all WiFi standards and other IoT narrowband radio protocols, such us Bluetooth Low Energy or Zigbee.This work was supported in part by the Spanish National Projects TEC2016-75934-C4-4-R, TEC2016-76465-C2-1-R and in part by Regional Seneca Project 19494/PI/14
The use of videogames as digital leisure among people with autism spectrum disorder
Digital leisure and specifically videogames are increasingly entrenched in all segments of society. Making appropriate use of them implies a challenge for users, families, and professionals. In the present study, the use that people with Autism Spectrum Disorders make of this sort of entertainment is specifically approached, and a series of recommendations are presented that take the characteristics of this population into account. A questionnaire was prepared ad hoc for data-collection purposes and administered to 67 people with ASD of different ages. The results reflect that videogames are a very popular type of game among people with ASD, are perceived as highly attractive and motivating and can help to lower anxiety levels. Among the undesired aspects, the physical problems arising from the use of videogames may be highlighted, and the problems of addiction and isolation that their continual use can provoke. The widespread acceptance of this type of leisure among people with ASD calls for new studies of a qualitative nature for the analysis of the relevant variables.El ocio digital, y en concreto los videojuegos, están cada vez más afianzados en todos los segmentos de la sociedad. Hacer un uso adecuado de ellos implica un desafío para los usuarios, familias y profesionales. En el presente estudio se aborda de manera específica el uso que las personas con Trastornos del Espectro Autista hacen de este tipo de entretenimiento y se presentan una serie de recomendaciones que toman en cuenta las características de esta población. Para ello, se elaboró un cuestionario ad hoc y se administró a 67 personas con TEA de diferentes edades. Los resultados reflejan que los videojuegos son un tipo de juego muy popular entre las personas con TEA, se perciben como muy atractivos y motivadores y pueden ayudar a reducir los niveles de ansiedad. Entre los aspectos no deseados, se pueden destacar los problemas físicos derivados del uso de videojuegos y los problemas de adicción y aislamiento que puede provocar su uso continuado. La amplia aceptación de este tipo de ocio entre las personas con TEA exige nuevos estudios de carácter cualitativo para el análisis de las variables relevantes
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