Online Learning Algorithm for Time Series Forecasting Suitable for Low Cost Wireless Sensor Networks Nodes

Time series forecasting is an important predictive methodology which can be applied to a wide range of problems. Particularly, forecasting the indoor temperature permits an improved utilization of the HVAC (Heating, Ventilating and Air Conditioning) systems in a home and thus a better energy efficiency. With such purpose the paper describes how to implement an Artificial Neural Network (ANN) algorithm in a low cost system-on-chip to develop an autonomous intelligent wireless sensor network. The present paper uses a Wireless Sensor Networks (WSN) to monitor and forecast the indoor temperature in a smart home, based on low resources and cost microcontroller technology as the 8051MCU. An on-line learning approach, based on Back-Propagation (BP) algorithm for ANNs, has been developed for real-time time series learning. It performs the model training with every new data that arrive to the system, without saving enormous quantities of data to create a historical database as usual, i.e., without previous knowledge. Consequently to validate the approach a simulation study through a Bayesian baseline model have been tested in order to compare with a database of a real application aiming to see the performance and accuracy. The core of the paper is a new algorithm, based on the BP one, which has been described in detail, and the challenge was how to implement a computational demanding algorithm in a simple architecture with very few hardware resources.Comment: 28 pages, Published 21 April 2015 at MDPI's journal "Sensors

ATRATIVIDADE ORGANIZACIONAL: UMA REVISÃO TEÓRICA DAS PESQUISAS EMPÍRICAS MAIS RELEVANTES A PARTIR DE UMA PERSPECTIVA INTERACIONISTA.

Purpose: This research aims to analyze and deepen the study of the Organizational Attractiveness construct, identify the main gaps in the field, and propose possible future research in this regard.   Theoretical Framework: The shortage of talent in companies, the growing competition, and the new normality have made attracting talent a strategic but critical element for companies. In this sense, Organizational Attractiveness is recognized by various authors as a relevant construct to understand the attraction. In addition, these authors highlight some academic and empirical problems in this field of study.   Design/Methodology/Approach: The literature review of more than 300 articles from the Scopus, Web of Science, and Google Scholar databases allowed us to analyze the content and identify 12 articles that discuss the measurement of Organizational Attractiveness under the conceptual models and theoretical framework identified.   Findings: This theoretical research process has allowed us to identify four main gaps in this field of study. The gaps found are based on the comprehensive view of the dimensions of Organizational Attractiveness, the approaches to the study of Organizational Attractiveness, the methodology applied, and the sample studied.    Research, Practical & Social Implications: Future research is proposed to resolve the gaps.   Originality/Value: Although attraction and Organizational Attractiveness have proven strategic and critical, there is little research in the literature that acknowledges the gaps in the field of study. Identifying and closing these gaps could help companies better attract talent.Propósito: Esta investigación tiene como objetivo analizar y profundizar en el estudio del constructo Atractivo Organizacional, identificar los principales vacíos en el campo y proponer posibles investigaciones futuras al respecto.   Metodología: La revisión bibliográfica de más de 300 artículos de las bases de datos Scopus, Web of Science y Google Scholar permitió analizar el contenido e identificar 12 artículos que abordan la medición del Atractivo Organizacional bajo tres modelos conceptuales.   Conclusiones: Este proceso de investigación teórica nos ha permitido identificar cuatro vacíos principales en este campo de estudio. Los vacíos encontrados se basan en la visión integral de las dimensiones del Atractivo Organizacional, los enfoques del estudio del Atractivo Organizacional, la metodología aplicada y la muestra estudiada.   Implicaciones de la Investigación: Se proponen investigaciones futuras para resolver los vacíos hallados.    Objetivo: Esta pesquisa tem como objetivo analisar e aprofundar o estudo do construto Atratividade Organizacional, identificar as principais lacunas da área e propor possíveis pesquisas futuras nesse sentido. Referencial teórico: A escassez de talento nas empresas, a crescente concorrência e a nova normalidade tornaram a atração de talento um elemento estratégico mas crítico para as empresas. Nesse sentido, a Atratividade Organizacional é reconhecida por diversos autores como um construto relevante para compreender a atração. Além disso, esses autores destacam alguns problemas acadêmicos e empíricos nesse campo de estudo. Desenho/metodologia/abordagem: A revisão da literatura de mais de 300 artigos das bases de dados Scopus, Web of Science e Google Scholar permitiu analisar o conteúdo e identificar 12 artigos que discutem a mensuração da Atratividade Organizacional sob os modelos conceituais e referencial teórico identificado.  Resultados: Este processo de pesquisa teórica permitiu identificar quatro lacunas principais neste campo de estudo. As lacunas encontradas baseiam-se na visão abrangente das dimensões da Atratividade Organizacional, nas abordagens ao estudo da Atratividade Organizacional, na metodologia aplicada e na amostra estudada. Pesquisa, implicações práticas e sociais: Pesquisas futuras são propostas para resolver as lacunas. Originalidade/valor: Embora a atração e a atratividade organizacional tenham se mostrado estratégicas e críticas, há poucas pesquisas na literatura que reconheçam as lacunas no campo de estudo. Identificar e fechar essas lacunas pode ajudar as empresas a atrair melhor os talentos. &nbsp

Methodological approach for mapping ecosystem services in urban and suburban areas.

In Urban and suburban areas, the technology of remote sensing can offer a practical and economical means to study ecological quality of cities based on the specific functions or functional groups/biodiversity which support the supply of ecosystem services (e.g. habitats for species, maintenance of genetic diversity). This is because many ES are ecological processes or directly products by them. Other ecological processes can have detrimental effects on service supply. Thus, mapping the spatial distribution and the degree of ecosystem functionality can provide useful information of the service provided by them to the urban population. Within the framework of the Urbangaia project, the purpose of this study is to bridge present a methodology of ecosystem service related research in ecology and remote sensing in urban areas. Specifically, the study presents a remote sensing-based method for ES potential assessment in four European studies cases- Ghent, Coimbra, Vilnius and Leipzing-. Land cover was used as a proxy measure of ecosystem services because of its multiple linkages to carbon storage, watershed protection, and other types of services. For each land cover type, the services provided by the ecosystem are identified and given a monetary value based on previous studies and original calculations. A GeoEye-1 Satellite Sensor (0.5m spatial resolution) has been used in each study case, for its broad spatial coverage of its images. Several key areas are considered such as land cover, biodiversity, carbon, water and soil related ecosystem service. By the analysis of the different studies cases, the study also gives some global recommendation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Does malaga city have green and blue infraestructures? analysis of their ecological connectivity, population accesibility and potential ecosystem services

Ecosystem services (ES) are defined as “benefits people obtain from ecosystems”, and classified as provisioning, regulation and maintenance, and cultural services. Nowadays, there is continuous search for incrementing wellbeing, besides a higher concern for environment. Accordingly, ES contribute positively to decrease these concerns. Green and blue infrastructures (GBI) play an important role in the regulation of natural cycles in urban and periurban areas, providing a number of ES, not always considered in planning and decision making process. GBI may be designed to reduce the ecological footprint, reduce natural hazards, and improve the quality of urban living environment (e.g air quality, water quality, noise, climate, aesthetics). GBI provide space for relaxation and restoration as well as exercise and leisure activities, promote new green services and jobs, and therefore increase the resilience of cities facing the Global Change. Many Mediterranean cities present few spaces considered as GBI. In our case study, does Málaga city have GBI providing ES to its population? Málaga is a Mediterranean city of importance in southern Europe due to its strategic location and good communications. It has a population of almost 600.000 people plus the great amount of tourist throughout the year. Thus, it would be rather important to have GBI improving urban quality life and well-being.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Available water modifications by topsoil treatments under mediterranean semiarid conditions: afforestation plan

During dry periods in the Mediterranean area, the lack of water entering the soil matrix reduces organic contribu- tions to the soil. These processes lead to reduced soil fertility and soil vegetation recovery which creates a positive feedback process that can lead to desertification. Restoration of native vegetation is the most effective way to regenerate soil health, and control runoff and sediment yield. In Mediterranean areas, after a forestry proposal, it is highly common to register a significant number of losses for the saplings that have been introduced due to the lack of rainfall. When no vegetation is established, organic amendments can be used to rapidly protect the soil surface against the erosive forces of rain and runoff. In this study we investigated the hydrological effects of five soil treatments in relation to the temporal vari- ability of the available water for plants. Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis L.); TerraCotten hydroabsobent polymers; sewage sludge; sheep manure and control. Plots were afforested following the same spatial pattern, and amendments were mixed with the soil at the rate 10 Mg ha-1. In control plots, during June, July, August and September, soils were registered below the wilting point, and therefore, in the area of water unusable by plants. These months were coinciding with the summer mediter- ranean drought. This fact justifies the high mortality found on plants after the seeding plan. Similarly, soils have never exceeded the field capacity value measured for control plots. Conversely, in the straw and pinus mulch, soils were above the wilting point during a longer time than in control plots. Thus, the soil moisture only has stayed below the 4.2 pF suction in July, July and August. Regarding the amount of water available was also higher, especially in the months of December, January and February. However, the field capacity value measured has not showed any differences regarding the control. For these treatments, the survival sapling rates measured were the highest. Sludge, manure and polymers showed a moisture retention capacity slightly more limited than straw and pinus mulch. Likewise, it has been found that the area of usable water by plants was also lower, especially during the months of January and February. This situation is especially sharpened in plots amended with manure. In this treatment, the upper part of the soil profile was below the wilting point for six months a year (from April to August). For this treatment, the survival sapling rates measured were the lowest. In conclusion, from a land management standpoint, the pinus and straw mulch treatments have been shown as effective methods reducing water stress for plants. In this research, mulching has been proved as a significant method to reduce the mortality sapling rates during the mediterranean summer drought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Impact of prescribed fire in soil properties after 5-years: experimental study.

Wildfires are a serious problem in areas with a Mediterranean climate owing to the hot summers and drought conditions providing perfect conditions for wildfire, especially when there are large amounts of fuel accumulation and continuity between forested areas. In the Mediterranean, high severity fires that spread rapidly are common and difficult to be extinguished. Thus, the identification of tools to reduce fire spread and minimize their incidence and effects is crucial. Preventive forestry is a good tool for achieving forest structures with lower amounts of fuel and a greater resistance to fire. Prescribed fire is the planned use of fire under predetermined weather, fuel and topographic parameters to achieve clearly defined objectives as controlling fire regimes by managing fuel, counteracting the disappearance of biomass-consuming land management practices and reducing the overall fire risk. Normally, prescribed fires are low intensity fires and, if managed adequately, do not cause any damage to trees, especially in Mediterranean ecosystems where trees are resilient to fire. Besides, prescribed fires usually have different impacts on soils, water resources, biodiversity, the risk-reduction of wildfires and carbon storage. Prescribed fires usually are of low/moderate severity. Because of this, the effects of prescribed fires on soils properties may vary from one site to another. The objectives of our study are to: i) determine the impact of the prescribed fire just after and ii) 5-years later with respect to natural conditions. To do this, in 2011, a prescribed fire was conducted in one experimental area of Mediterranean rangeland. After the fire, soil samples (0-5 cm of depth) were taken in burned and unburned plots in order to analyse: pH, electrical conductivity (EC), soil organic carbon, cationic exchangeable capacity (CEC), aggregate stability (AS), and hydrophobicity. The results indicated that: i) prescribed fire only had significantly effects in CEC just after the fire; 5-years after, there were no significant differences between the unburned and burned plots, but two soil properties significantly changed when burned soil samples from 2016 and 2011 were compared: EC and AS in the fraction of 0.053-0.125 mm. In general, the soil properties were not substantially modified by the prescribed fire, supporting the idea it is a very useful tool with very low impact for managing Mediterranean rangelands in order to reduce fuel accumulation and fire risk.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Hydrological and sediment connectivity in three grazed Mediterranean hillslopes.

Masselink et al. (2016) addressed the concept of connectivity addresses the spatial and temporal variability in runoff, sediment transport and associated substances such as pollutants and how these move through the catchment. Sediment connectivity explains which sediment sources contribute and where (semi-) permanent sinks and pathways of sediment are (Bracken & Croke, 2007). The Mediterranean eco-geomorphological landscape is highly dependent on the climatic conditions. Its elements form the spatial patterns of landscapes, which control the structural connectivity. The existence of rainfall gradients in the Mediterranean region has been well-documented (Lavee et al., 1998) along which those elements are modified by the spatio-temporal variability of rainfalls. The characteristics of those elements are modified from the rainiest to the driest regions following a positive feedback process leading to soil erosion and degradation. As the climate becomes less rainy, the patchy vegetation pattern becomes frequent and bare soil areas can be easily connected whether the magnitude and intensity of rainfall exceed a certain threshold (Cammeraat, 2004). The interaction between topography and processes occurring within catchments is key to understanding dynamics of hydrological connectivity (Wainwright et al, 2011). Our study evaluated the hydrological and sediment connectivity between sections (top, middle and bottomchannel) from three grazed hillslopes located under contrasted Mediterranean climatic conditions. Rain-gauge stations and opened-plots were installed in order to register overland flow and sediment concentration from Feb-2008 to Jan-2010. The results indicated that: i) major volumes of overland flow and sediment transport occurred more frequently in humid and semiarid sites; ii) the more frequent hydrological connectivity was observed between the middle and bottom-channel sections, though the major values of overland flow and sediment concentration were registered in the upper sections; iii) it was found very frequent those rainfall events in which all sections contributed with overland flow and sediment to the channel; iv) the factors controlling hydrological and sediment connectivity varied from one site to another depending on the rainfall regime and vegetation cover, though the soil surface conditions were found a key factor in all of them. In summary, the grazing activity contribute to distance the hydrological and sediment connectivity processes from three hillslopes located under contrasted Mediterranean climatic conditions from the response expected for the three of them. References Bracken LJ, Croke J. 2007. The concept of hydrological connectivity and its contribution to understanding runoff-dominated geomorphic systems. Hydrological Processes 21: 1749–1763. Cammeraat ELH. 2004. Scale dependent thresholds in hydrological and erosion response of a semi-arid catchment in Southeast Spain. Agriculture, Ecosystems and Environment 104: 317–332. Lavee H, Imeson AC, Sarah P. 1998. The impact of climate change on geomorphology and desertification along a Mediterranean-arid transect. Land Degrad. Develop. 9: 407-422. Masselink RJH, Keesstra SD, Temme AJAM, Seeger M, Giménez R, Casalí J. 2016. Modelling discharge and sediment yield at catchment scale using connectivity components. Land Degrad. Develop. 27: 933-945. Wainwright J, Turnbull L, Ibrahim TG, Lexartza-Artza I, Thornton SF, Brazier R. 2011. Linking environmental regimes, space and time: interpretations of structural and functional connectivity. Geomorphology 126: 387–404.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

AN AUTOMATIC AND METHODOLOGICAL APPROACH FOR ACCESSIBLE WEB APPLICATIONS

Semantic Web approaches try to get the interoperability and communication among technologies and organizations. Nevertheless, sometimes it is forgotten that the Web must be useful for every user, consequently it is necessary to include tools and techniques doing Semantic Web be accessible. Accessibility and usability are two usually joined concepts widely used in web application development, however their meaning are different. Usability means the way to make easy the use but accessibility is referred to the access possibility. For the first one, there are many well proved approaches in real cases. However, accessibility field requires a deeper research that will make feasible the access to disable people and also the access to novel non-disable people due to the cost to automate and maintain accessible applications. In this paper, we propose one architecture to achieve the accessibility in web-environments dealing with the WAI accessibility standard and the Universal Design paradigm. This architecture tries to control the accessibility in web applications development life-cycle following a methodology starting from a semantic conceptual model and leans on description languages and controlled vocabularies