An Analysis of Global Research Trends on Greenhouse Technology: Towards a Sustainable Agriculture

Greenhouse farming is an agricultural management system that has demonstrated its efficiency in intensifying food production. These systems constitute a feasible alternative for ensuring food supply, which is one of the greatest challenges faced by humankind in the twenty-first century. Technology has been able to meet the challenges related to greenhouse farming in both contributing to overcoming its limitations, correcting adverse impacts and ensuring system sustainability. The objective of this article is to analyse the global research trends in greenhouse technology over the last two decades, in order to identify the main driving agents, the most outstanding research lines and possible gaps in the literature. Different methodologies have been used for the analysis; both quantitative and qualitative. The principal results show that there are different relevant lines of research related to different aspects of greenhouse farming: the use of water for irrigation, the design of the optimum structure of the greenhouse, conserving the soil in the best growing conditions, energy consumption of the system as a whole, climate control within the facility and pest control. The research is characterized by the being composed largely of ad hoc studies, which hinders the international collaboration between researchers and institutions. The research approach has shifted from being focused on increasing production and cost savings to aspects related to resource conservation and sustainability

Effect of agro-climatic conditions on near infrared spectra of extra virgin olive oils

Authentication of extra virgin olive oil requires fast and cost-effective analytical procedures, such as near infrared spectroscopy. Multivariate analysis and chemometrics have been successfully applied in several papers to gather qualitative and quantitative information of extra virgin olive oils from near infrared spectra. Moreover, there are many examples in the literature analysing the effect of agro-climatic conditions on food content, in general, and in olive oil components, in particular. But the majority of these studies considered a factor, a non-numerical variable, containing this meteorological information. The present work uses all the agro-climatic data with the aim of highlighting the linear relationships between them and the near infrared spectra. The study begins with a graphical motivation, continues with a bivariate analysis and, finally, applies redundancy analysis to extend and confirm the previous conclusions.Peer Reviewe

Exploiting Wireless Sensors: a gateway for 868MHz sensors

[ANGLÈS] The great interest in monitoring everything around us has increased the number of sensors that we utilize in our daily lives. Furthermore, the evolution of wireless technologies has facilitated their ubiquity. Moreover, is in locations such as homes and offices where exploitation of the data from these sensors has been more important. For example, we want to know if the temperature in our home is adequate, otherwise we want to turn on the heating (or cooling) system automatically and we want to be able to monitor the environment of the home or office remotely. The knowledge from these sensors and the ability to actuate devices, summon human assistance, and adjust contracts for electrical power, heating, cooling, etc. can facilitate a myriad of ways to improve the quality of our life and potentially even reduce resource consumption. This master?s thesis project created a gateway that sniffs wireless sensor traffic in order to collect data from existing sensors and to provide this data as input to various services. These sensors work in the 868 MHz band. Although these wireless sensors are frequently installed in homes and offices, they are generally not connected to any network. We designed a gateway capable of identifying these wireless sensors and decoding the received messages, despite the fact that these messages may use a vendor?s proprietary protocol. This gateway consists of a microcontroller, a radio transceiver (868-915 MHz), and an Ethernet controller. This gateway enables us to take advantage of all the data that can be captured. Thinking about these possibilities, imultaneously acquiring data from these various sensors could open a wide range of alternatives in different fields, such as home automation, industrial controlling? Not only can the received data be interesting by itself; but when different sensors are located in the same environment we can exploit this data using sensor fusion. For example, time differences in arrival and differences in signal strength as measured t multiple receivers could be used to locate objects. The final aim of this thesis project is to support diverse applications that could be developed using the new gateway. This gateway creates a bridge between the information that is already around us and our ability to realize many new potential services. A wide range of opportunities could be realized by exploiting the wireless sensors we already have close to us.[CASTELLÀ] El gran interés en el seguimiento de todo lo que nos rodea ha incrementado el número de sensores que utilizamos en nuestra vida diaria. Por otra parte, la evolución de la tecnología inalámbrica ha facilitado su instalación. Es en lugares como casas y oficinas donde el aprovechamiento de los datos de estos sensores ha sido más importante. Por ejemplo, si queremos saber si la temperatura en casa es la adecuada para activar el sistema de calefacción (o refrigeración) de forma automática. La capacidad para accionar dispositivos externos y ajustar los contratos de energía eléctrica, calefacción, refrigeración, etc. puede facilitar una gran variedad de formas de mejorar la calidad de nuestra vida y, potencialmente, incluso reducir el consumo de recursos. Este proyecto de tesis ha creado una gateway que detecta el tráfico de sensores inalámbricos con el fin de recoger datos de los sensores existentes y proporcionarlos como entrada a varios servicios. Estos sensores funcionan en la banda de 868 MHz. A pesar de que estos sensores inalámbricos son frecuentemente instalados en hogares y oficinas, generalmente no están conectados a ninguna red. Hemos diseñado una gateway capaz de identificar estos sensores inalámbricos y descodificar los mensajes recibidos, aunque estos mensajes pueden utilizar un protocolo exclusivo del propietario. Esta gateway consta de un microcontrolador, un transceptor de radio (868-915 MHz) y un controlador Ethernet. Esta gateway nos permite tomar ventaja de todos los datos que se pueden capturar. Pensando en todas estas posibilidades a la vez, la adquisición de los datos de estos diversos sensores podría abrir una amplia gama de alternativas en diferentes campos, como la automatización del hogar, control industrial ... No sólo los datos recibidos pueden ser interesantes, sino que los diferentes sensores que se encuentran en el mismo entorno pueden explotar estos datos mediante la fusión de sensores. Por ejemplo, las diferencias de tiempo en la llegada y las diferencias en intensidad de la señal, según lo que determina múltiples receptores también podría ser utilizado para localizar objetos. El objetivo final de este proyecto de tesis es dar apoyo a las diversas aplicaciones que pueden ser desarrolladas utilizando la nueva gateway. Esta gateway crea un puente entre la información que ya está a nuestro alrededor y nuestra capacidad de realizar muchos nuevos servicios potenciales. Una amplia gama de posibilidades puede ser generada mediante la explotación red de sensores inalámbricos que ya están presentes en nuestro alrededor.[CATALÀ] El gran interès en el seguiment de tot el que ens envolta ha incrementat el nombre de sensors que utilitzem en la nostra vida diària. D'altra banda, l'evolució de la tecnologia sense fils ha facilitat la seva instal·lació. És en llocs com cases i oficines on l'aprofitament de les dades d'aquests sensors ha estat més important. Per exemple, si volem saber si la temperatura a casa és l'adequada per activar el sistema de calefacció (o refrigeració) de forma automàtica. La capacitat per accionar dispositius externs i ajustar els contractes d'energia elèctrica, calefacció, refrigeració, etc. pot facilitar una gran varietat de formes de millorar la qualitat de la nostra vida i, potencialment, fins i tot reduir el consum de recursos. Aquest projecte de tesi ha creat una gateway que ensuma el tràfic de sensors sense fils amb la finalitat de recollir dades dels sensors existents i proporcionar-les com a entrada de diversos serveis. Aquests sensors funcionen a la banda de 868 MHz. Malgrat aquests sensors sense fils són sovint instal·lats en llars i oficines, generalment no estan connectats a cap xarxa. Hem dissenyat una gateway capaç d'identificar aquests sensors sense fil i descodificar el missatges rebuts, tot i que aquests missatges poden utilitzar un protocol exclusiu del propietari. Aquesta gateway consta d'un microcontrolador, un transceptor de ràdio (868-915 MHz) i un controlador Ethernet. Aquesta gateway ens permet prendre avantatge de totes les dades que es poden capturar. Pensant en totes aquestes possibilitats a la vegada, l'adquisició de les dades d'aquests diversos sensors podria obrir una àmplia gamma d'alternatives en diferents camps, com ara l'automatització de la llar, control industrial ... No només les dades rebudes poden ser interessants, sinó que els diferents sensors que es troben en el mateix entorn poden explotar aquestes dades mitjançant la fusió de sensors. Per exemple, les diferències de temps en l'arribada i les diferències en intensitat del senyal segons el que determina múltiples receptors també podria ser utilitzat per localitzar objectes. L'objectiu final d'aquest projecte de tesi és donar suport a les diverses aplicacions que poden ser desenvolupades utilitzant la nova gateway. Aquesta gateway crea un pont entre la informació que ja està al nostre voltant i la nostra capacitat de realitzar nous serveis potencials . Una àmplia gamma de possibilitats pot ser generada mitjançant l'explotació de la xarxa de sensors sense fils que ja tenim a prop nostre

A Formulation of the Log-Logistic Distribution for Fading Channel Modeling

In some scenarios, the log-logistic (LL) distribution is shown to provide the best fit to field measurements in the context of wireless channel modeling. However, a fading channel model based on the LL distribution has not been formulated yet. In this work, we introduce the L-distribution as a reformulation of the LL distribution for channel modeling purposes. We provide closed-form expressions for its PDF, CDF, and moments. Performance analysis of wireless communication systems operating under L-fading channels is exemplified, providing exact and asymptotic expressions for relevant metrics such as the outage probability and the average capacity. Finally, important practical aspects related to the use of the L-distribution for channel fitting purposes are discussed in two contexts: (i) millimeter-wave links with misaligned gain, and (ii) air–ground channels in unmanned aerial vehicle communications.European Social and Regional FundsJunta de Andalucia P18-RT-3175 UMA20-FEDERJA-002Universidad de MalagaUniversidad de Granad

Efeitos do solo e clima numa vinha de uva de mesa com cultura de cobertura. Gestão da rega utilizando redes de sensores

[ENG] TThe use of mulches in vineyards and orchards is a traditional agricultural practice used with the aim of saving moisture, reducing weed growth and improving organic matter content in the soil. In table grape vineyards trained to overhead system in Puglia region (Southeastern Italy), plastic sheets covering the canopy are often used to either advance ripening or delay harvest. In this environment, the living mulches could contribute to the modification of the microclimate around the canopy below the plastic sheets. This condition has an influence on the climatic demand and on both the vegetative and productive activities, mainly in stages with a high evapotranspiration. However, the presence of living mulches could increase the demand of available water and nutrient resources and this could cause a lower yield. The aim of this study was to acquire a suitable knowledge to manage irrigation and verify the influences of living mulches on the vine by using wireless sensor networks to measure the vapor pressure deficit, soil water potential and content.[POR] A utilização de coberturas do solo em vinhas e pomares é uma prática agrícola tradicional, utilizada com o objetivo de preservar a humidade do solo, reduzir o crescimento de infestantes e melhorar o teor de matéria orgânica no solo. Em vinhas de uva de mesa, conduzidas em sistema de pérgula na região de Puglia (sudeste da Itália), são frequentemente usadas coberturas de plástico para promover o avanço da maturação ou o atraso da colheita. Neste ambiente a utilização de enrelvamentos pode contribuir para a modificação do microclima do copado. Esta condição pode influenciar a demanda atmosférica, bem como a atividade vegetativa e reprodutiva da videira, principalmente em períodos de elevada evapotranspiração. No entanto, a presença do enrelvamento pode originar um aumento da demanda dos recursos disponíveis, nomeadamente água e nutrientes, o que poderá provocar uma quebra de produção. O objetivo deste estudo foi adquirir conhecimento para a gestão da rega e, simultaneamente, verificar a influência dos enrelvamentos na atividade da videira, usando para o efeito redes de sensores “sem fio” para medir o déficit de pressão de vapor, o potencial e o conteúdo de água no solo.The development of this work was supported by: The Spanish Ministry of Science and Innovation through the project RIDEFRUT (ref. AGL2013-49047-C2-1-R), the “Fundacion Seneca, Agencia de Ciencia y Tecnologia” of the Region of Murcia under the “Excelence Group Program”, and the Technical University of Cartagena under the PMPDI Program

Program development using abstract interpretation (and the ciao system preprocessor)

The technique of Abstract Interpretation has allowed the development of very sophisticated global program analyses which are at the same time provably correct and practical. We present in a tutorial fashion a novel program development framework which uses abstract interpretation as a fundamental tool. The framework uses modular, incremental abstract interpretation to obtain information about the program. This information is used to validate programs, to detect bugs with respect to partial specifications written using assertions (in the program itself and/or in system librarles), to genérate and simplify run-time tests, and to perform high-level program transformations such as múltiple abstract specialization, parallelization, and resource usage control, all in a provably correct way. In the case of validation and debugging, the assertions can refer to a variety of program points such as procedure entry, procedure exit, points within procedures, or global computations. The system can reason with much richer information than, for example, traditional types. This includes data structure shape (including pointer sharing), bounds on data structure sizes, and other operational variable instantiation properties, as well as procedure-level properties such as determinacy, termination, non-failure, and bounds on resource consumption (time or space cost). CiaoPP, the preprocessor of the Ciao multi-paradigm programming system, which implements the described functionality, will be used to illustrate the fundamental ideas

PVT-Robust CMOS Programmable Chaotic Oscillator: Synchronization of Two 7-Scroll Attractors

Designing chaotic oscillators using complementary metal-oxide-semiconductor (CMOS) integrated circuit technology for generating multi-scroll attractors has been a challenge. That way, we introduce a current-mode piecewise-linear (PWL) function based on CMOS cells that allow programmable generation of 2–7-scroll chaotic attractors. The mathematical model of the chaotic oscillator designed herein has four coefficients and a PWL function, which can be varied to provide a high value of the maximum Lyapunov exponent. The coefficients are implemented electronically by designing operational transconductance amplifiers that allow programmability of their transconductances. Design simulations of the chaotic oscillator are provided for the 0.35μ m CMOS technology. Post-layout and process–voltage–temperature (PVT) variation simulations demonstrate robustness of the multi-scroll chaotic attractors. Finally, we highlight the synchronization of two seven-scroll attractors in a master–slave topology by generalized Hamiltonian forms and observer approach. Simulation results show that the synchronized CMOS chaotic oscillators are robust to PVT variations and are suitable for chaotic secure communication applications.Universidad Autónoma de Tlaxcala CACyPI-UATx-2017Program to Strengthen Quality in Educational Institutions C/PFCE-2016-29MSU0013Y-07-23National Council for Science and Technology 237991 22284

Pathological element-based active device models and their application to symbolic analysis

This paper proposes new pathological element-based active device models which can be used in analysis tasks of linear(ized) analog circuits. Nullators and norators along with the voltage mirror-current mirror (VM-CM) pair (collectively known as pathological elements) are used to model the behavior of active devices in voltage-, current-, and mixed-mode, also considering parasitic elements. Since analog circuits are transformed to nullor-based equivalent circuits or VM-CM pairs or as a combination of both, standard nodal analysis can be used to formulate the admittance matrix. We present a formulation method in order to build the nodal admittance (NA) matrix of nullor-equivalent circuits, where the order of the matrix is given by the number of nodes minus the number of nullors. Since pathological elements are used to model the behavior of active devices, we introduce a more efficient formulation method in order to compute small-signal characteristics of pathological element-based equivalent circuits, where the order of the NA matrix is given by the number of nodes minus the number of pathological elements. Examples are discussed in order to illustrate the potential of the proposed pathological element-based active device models and the new formulation method in performing symbolic analysis of analog circuits. The improved formulation method is compared with traditional formulation methods, showing that the NA matrix is more compact and the generation of nonzero coefficients is reduced. As a consequence, the proposed formulation method is the most efficient one reported so far, since the CPU time and memory consumption is reduced when recursive determinant-expansion techniques are used to solve the NA matrix.Promep-Mexico UATLX-PTC-088Junta de Andalucía TIC-2532Ministerio de Educación y Ciencia TEC2007-67247, TEC2010-14825UC-MEXUS-CONACyT CN-09-31