Short-term solar irradiation forecasting based on dynamic harmonic regression

Solar power generation is a crucial research area for countries that have high dependency on fossil energy sources and is gaining prominence with the current shift to renewable sources of energy. In order to integrate the electricity generated by solar energy into the grid, solar irradiation must be reasonably well forecasted, where deviations of the forecasted value from the actual measured value involve significant costs. The present paper proposes a univariate Dynamic Harmonic Regression model set up in a State Space framework for short-term (1 to 24 hours) solar irradiation forecasting. Time series hourly aggregated as the Global Horizontal Irradiation and the Direct Normal Irradiation will be used to illustrate the proposed approach. This method provides a fast automatic identification and estimation procedure based on the frequency domain. Furthermore, the recursive algorithms applied offer adaptive predictions. The good forecasting performance is illustrated with solar irradiance measurements collected from ground-based weather stations located in Spain. The results show that the Dynamic Harmonic Regression achieves the lowest relative Root Mean Squared Error; about 30% and 47% for the Global and Direct irradiation components, respectively, for a forecast horizon of 24 hours ahead

Caracterización morfológica y cultural de aislados de "Colletotrichum" spp. causantes de la Antracnosis del olivo

La Antracnosis del olivo, causada por especies fúngicas del género Colletotrichum, es una enfermedad grave ampliamente distribuida en todas la regiones del mundo donde se cultiva el olivo. La incidencia de la enfermedad varia marcadamente en función de la susceptibilidad varietal, las condiciones climáticas y la virulencia del patógeno. Uno de los aspectos menos conocido de la enfermedad es la identificación del patógeno. Recientemente, se ha indicado que son dos las especies de Colletotrichum (C. acutatum y C. gloeosporioides) responsables de la Antracnosis del olivo, en lugar de una única especie (C. gloeosporioides = Gloeosporium olivarum) como se había considerado hasta ahora. En este trabajo se presentan los resultados de la caracterización morfológica y cultural de una colección de aislados de Colletotrichum obtenidos de olivos afectados de Antracnosis en varias comarcas olivareras de Andalucía. Aunque se han estudiado numerosos caracteres morfológicos y culturales, ninguno permitió una separación clara entre grupos de aislados o especies. No obstante, la forma de los extremos de las conidias fue el carácter más importante para su diferenciación. Casi todos los aislados de Colletotrichum de olivo (96%) tuvieron la mayoría de las conidias con un extremo redondeado y el otro agudo, diferenciándose de las conidias de C. gloeosporioides, con los dos extremos redondeados, y de las de C. acutatum, con los dos extremos agudos. Otras características estudiadas, como la coloración y el crecimiento de la colonia, la presencia de setas en los acérvulos, la presencia y morfología de las clamidosporas, la longitud y anchura de las conidias, o la formación de apresónos y conidias secundarias, mostraron una amplia variabilidad. Atendiendo a los resultados obtenidos, los aislados de Colletotrichum causantes de la Antracnosis del olivo en Andalucía se clasificarían dentro del complejo C. acutatum / C. gloeosporioides. Si bien, han mostrado características morfológicas y culturales más próximas a la especie C. acutatum. Su identificación definitiva requerirá de estudios adicionales para la caracterización fisiológica, molecular y patogénica de los aislados

Estudio de viabilidad económica de la implantación de bioceldas en una planta de tratamiento de aguas residuales

Las aguas residuales generadas en la industria de los zumos se caracterizan entre otras cosas por presentar altas concentraciones de materia orgánica, la cual es muy costosa de eliminar con los tratamientos que existen actualmente.En los últimos años están surgiendo numerosos estudios en torno al uso de celdas de combustible microbiológicas o bioceldas como método de tratamiento de aguas residuales. En este artículo se ha realizado un estudio de viabilidad económica de la implantación de 10 bioceldas para tratar las aguas residuales generadas en una industria de este tipo. Para ello, se analizaron tres posibles escenarios que podrían darse utilizando estos sistemas y se compararon los resultados obtenidos con el uso de un reactor convencional de fangos activos. Los resultados obtenidos para el VAN mostraron que la utilizaciónde bioceldas podría proporcionar un ahorro comprendido entre un 10 y 20 % aproximadamente dependiendo de si es un escenario pesimista u optimista, respectivamente, teniendo en cuenta un tiempo de vida de la planta de 15 años. El área de electrodo por celda considerada en este estudio fue de 0,36 m2, la cual dio lugar a densidades de potencia algo más altas que las encontradas en la bibliografía. Por ello, se decidió realizar un análisis de sensibilidad considerando áreas de electrodo de 0,5 m2 y 0,8 m2 en las bioceldas. Se encontró que aún utilizandoáreas de 0,5 m2 el VAN seguiría siendo positivo en todos los escenarios considerados y para el valor de 0,8 m2 se obtuvieron también resultados favorables en el escenario optimista. Estos resultados muestran que siempre que se cumplan los criterios establecidos en este estudio, la depuración mediante bioceldas en una industria de este tipo podría ser una alternativa más rentable que la depuración convencional mediante fangos activos

EQUIPT: protocol of a comparative effectiveness research study evaluating cross-context transferability of economic evidence on tobacco control

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial.This article has been made available through the Brunel Open Access Publishing Fund.Tobacco smoking claims 700 000 lives every year in Europe and the cost of tobacco smoking in the EU is estimated between €98 and €130 billion annually; direct medical care costs and indirect costs such as workday losses each represent half of this amount. Policymakers all across Europe are in need of bespoke information on the economic and wider returns of investing in evidence-based tobacco control, including smoking cessation agendas. EQUIPT is designed to test the transferability of one such economic evidence base-the English Tobacco Return on Investment (ROI) tool-to other EU member states

Genetic diversity and population structure of Ascochyta rabiei from the western Iranian Ilam and Kermanshah provinces using MAT and SSR markers

Knowledge of genetic diversity in A. rabiei provides different levels of information that are important in the management of crop germplasm resources. Gene flow on a regional level indicates a significant potential risk for the regional spread of novel alleles that might contribute to fungicide resistance or the breakdown of resistance genes. Simple sequence repeat (SSR) and mating type (MAT) markers were used to determine the genetic structure, and estimate genetic diversity and the prevalence of mating types in 103 Ascochyta rabiei isolates from seven counties in the Ilam and Kermanshah provinces of western Iran (Ilam, Aseman abad, Holaylan, Chardavol, Dareh shahr, Gilangharb, and Sarpul). A set of 3 microsatellite primer pairs revealed a total of 75 alleles; the number of alleles varied from 15 to 34 for each marker. A high level of genetic variability was observed among A. rabiei isolates in the region. Genetic diversity was high (He = 0.788) within populations with corresponding high average gene flow and low genetic distances between populations. The smallest genetic distance was observed between isolates from Ilam and Chardavol. Both mating types were present in all populations, with the majority of the isolates belonging to Mat1-1 (64%), but within populations the proportions of each mating type were not significantly different from 50%. Results from this study will be useful in breeding for Ascochyta blight-resistant cultivars and developing necessary control measures

Far Ultraviolet Absolute Flux of alpha Virginis

We present the far ultraviolet spectrum of alpha Virginis taken with EURD spectrograph on-board MINISAT-01. The spectral range covered is from ~900 to 1080 A with 5 A spectral resolution. We have fitted Kurucz models to IUE spectra of alpha Vir and compared the extension of the model to our wavelengths with EURD data. This comparison shows that EURD fluxes are consistent with the prediction of the model within 20-30%, depending on the reddening assumed. EURD fluxes are consistent with Voyager observations but are ~60% higher than most previous rocket observations of alpha Vir.Comment: 13 pages, 4 figures. Submitted to The Astrophysical Journa

Study protocol of cost-effectiveness and cost-utility of a biopsychosocial multidisciplinary intervention in the evolution of non-specific sub-acute low back pain in the working population: cluster randomised trial.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain (LBP), with high incidence and prevalence rate, is one of the most common reasons to consult the health system and is responsible for a significant amount of sick leave, leading to high health and social costs. The objective of the study is to assess the cost-effectiveness and cost-utility analysis of a multidisciplinary biopsychosocial educational group intervention (MBEGI) of non-specific sub-acute LBP in comparison with the usual care in the working population recruited in primary healthcare centres. Methods/design: The study design is a cost-effectiveness and cost-utility analysis of a MBEGI in comparison with the usual care of non-specific sub-acute LBP.Measures on effectiveness and costs of both interventions will be obtained from a cluster randomised controlled clinical trial carried out in 38 Catalan primary health care centres, enrolling 932 patients between 18 and 65 years old with a diagnosis of non-specific sub-acute LBP. Effectiveness measures are: pharmaceutical treatments, work sick leave (% and duration in days), Roland Morris disability, McGill pain intensity, Fear Avoidance Beliefs (FAB) and Golberg Questionnaires. Utility measures will be calculated from the SF-12. The analysis will be performed from a social perspective. The temporal horizon is at 3 months (change to chronic LBP) and 12 months (evaluate the outcomes at long term. Assessment of outcomes will be blinded and will follow the intention-to-treat principle. Discussion: We hope to demonstrate the cost-effectiveness and cost-utility of MBEGI, see an improvement in the patients' quality of life, achieve a reduction in the duration of episodes and the chronicity of non-specific low back pain, and be able to report a decrease in the social costs. If the intervention is cost-effectiveness and cost-utility, it could be applied to Primary Health Care Centres. Trial registration: ISRCTN: ISRCTN5871969

Stock control analytics: a data-driven approach to compute the fill rate considering undershoots

[EN] One of the most frequently used inventory policies is the order-point, order-up-to-level (s, S) system. In this system, the inventory is continuously reviewed and a replenishment request is placed whenever the inventory position drops to or below the order point, s. The variable replenishment order quantity and the variable replenishment cycle characterize the system by the use of complex mathematical computations. Different methodological approaches diminish the mathematical complexity by neglecting the undershoots, i.e., the quantity that the inventory position is below the order point when it is reached. In this paper, we conceptually and empirically analyse the bias that neglecting the undershoots introduces into the estimation of the fill rate. After that, we suggest a new methodology developed under a data-driven perspective that uses a state-dependent parameter algorithm to correct such a bias. As a result, we propose two new methods, one parametric and the other nonparametric, to enhance the fill rate estimate. Both methods, named analytics fill rate methods, remove the bias that neglecting the undershoots introduces and are used to illustrate the practical implications of this hypothesis on the performance and design of the (s, S) system. This research is developed in a lost sales context with simulated stochastic and i.i.d. discrete demands as well as actual sales data.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the European Regional Development Fund and Junta de Comunidades de Castilla-La Mancha (JCCM/FEDER, UE) under the project with reference SBPLY/19/180501/000151 and by the Vicerrectorado de Investigacion y Politica Cientifica from UCLM through the research group fund program (PREDILAB; [2021-GRIN-31210]). Funding for open access charge: CRUE-Universitat Politecnica de Valencia.Babiloni, E.; Guijarro, E.; Trapero, JR. (2023). Stock control analytics: a data-driven approach to compute the fill rate considering undershoots. Operational Research. 23(1):23-18. https://doi.org/10.1007/s12351-023-00748-y231823

Non-Linear Identification of Judgmental Forecasts Effects at SKU-Level

Prediction of demand is a key component within supply chain management. Im- proved accuracy in forecasts affects directly all levels of the supply chain, reduc- ing stock costs and increasing customer satisfaction. In many application areas, demand prediction relies on statistical software which provides an initial forecast subsequently modified by the expert’s judgment. This paper outlines a new method- ology based on State Dependent Parameter (SDP) estimation techniques to identify the non-linear behaviour of such managerial adjustments. This non-parametric SDP estimate is used as a guideline to propose a non-linear model that corrects the bias introduced by the managerial adjustments. One-step-ahead forecasts of SKU sales sampled monthly from a manufacturing company are utilized to test the proposed methodology. The results indicate that adjustments introduce a non-linear pattern undermining accuracy. This understanding can be used to enhance the design of the Forecasting Support System in order to help forecasters towards more efficient judgmental adjustments

Tobit Exponential Smoothing, towards an enhanced demand planning in the presence of censored data

ExponenTial Smoothing (ETS) is a widely adopted forecasting technique in both research and practical applications. One critical development in ETS was the establishment of a robust statistical foundation based on state space models with a single source of error. However, an important challenge in ETS that remains unsolved is censored data estimation. This issue is critical in supply chain management, in particular, when companies have to deal with stockouts. This work solves that problem by proposing the Tobit ETS, which extends the use of ETS models to handle censored data efficiently. This advancement builds upon the linear models taxonomy and extends it to encompass censored data scenarios. The results show that the Tobit ETS reduces considerably the forecast bias. Real and simulation data are used from the airline and supply chain industries to corroborate the findings.Comment: 18 pages, 5 figures, 3 tables