Grupo de Ingeniería Estadística Multivariante GIEM
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- PublicationEvaluation of corrective measures implemented for the preventive conservation of fresco paintings in Ariadne s house (Pompeii, Italy)(Chemistry Central, 2013-05) Merello Giménez, Paloma; García Diego, Fernando Juan; Zarzo Castelló, Manuel; Dpto. de Física Aplicada; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM; Centro de Investigación en Acuicultura y Medio Ambiente; Ministerio de Ciencia e InnovaciónBACKGROUND: A microclimate monitoring study was conducted in 2008 aimed at assessing the conservation risks affecting the valuable wall paintings decorating Ariadne s House (Pompeii, Italy). It was found that thermohygrometric conditions were very unfavorable for the conservation of frescoes. As a result, it was decided to implement corrective measures, and the transparent polycarbonate sheets covering three rooms (one of them delimited by four walls and the others composed of three walls) were replaced by opaque roofs. In order to examine the effectiveness of this measure, the same monitoring system comprised by 26 thermohygrometric probes was installed again in summer 2010. Data recorded in 2008 and 2010 were compared. RESULTS: Microclimate conditions were also monitored in a control room with the same roof in both years. The average temperature in this room was lower in 2010, and it was decided to consider a time frame of 18 summer days with the same mean temperature in both years. In the rooms with three walls, the statistical analysis revealed that the diurnal maximum temperature decreased about 3.5 ºC due to the roof change, and the minimum temperature increased 0.5 ºC. As a result, the daily thermohygrometric variations resulted less pronounced in 2010, with a reduction of approximately 4 ºC, which is favorable for the preservation of mural paintings. In the room with four walls, the daily fluctuations also decreased about 4 ºC. Based on the results, other alternative actions are discussed aimed at improving the conservation conditions of wall paintings. CONCLUSIONS: The roof change has reduced the most unfavorable thermohygrometric conditions affecting the mural paintings, but additional actions should be adopted for a long term preservation of Pompeian frescoes.
- PublicationA statistical approach for a-posteriori deployment of microclimate sensors in museums: a case study(MDPI AG, 2022-06) Frasca, Francesca; Verticchio, Elena; Merello, Paloma; Zarzo Castelló, Manuel; Grinde, Andreas; Fazio, Eugenio; García Diego, Fernando Juan; Siani, Anna Maria; Dpto. de Física Aplicada; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM; Centro de Investigación en Acuicultura y Medio Ambiente; COMISION DE LAS COMUNIDADES EUROPEA[EN] The deployment of sensors is the first issue encountered when microclimate monitoring is planned in spaces devoted to the conservation of artworks. Sometimes, the first decision regarding the position of sensors may not be suitable for characterising the microclimate close to climate sensitive artworks or should be revised in light of new circumstances. This paper fits into this context by proposing a rational approach for a posteriori deployment of microclimate sensors in museums where long-term temperature and relative humidity observations were available (here, the Rosenborg Castle, Copenhagen, Denmark). Different statistical tools such as box-and-whisker plots, principal component analysis (PCA) and cluster analysis (CA) were used to identify microclimate patterns, i.e., similarities of indoor air conditions among rooms. Box-and-whisker plots allowed us to clearly identify one microclimate pattern in two adjoining rooms located in the basement. Multivariate methods (PCA and CA) enabled us to identify further microclimate patterns by grouping not only adjoining rooms but also rooms located on different floors. Based on these outcomes, new configurations about the deployment of sensors were proposed aimed at avoiding redundant sensors and collecting microclimate observations in other sensitive locations of this museum.
- PublicationDispersal ability of Ceratitis Capitata (Diptera: Tephritidae): edge effect in area wide treatments(Wiley, 2014-07) Navarro Llopis, Vicente; Vacas González, Sandra; Zarzo Castelló, Manuel; Primo Millo, Jaime; Dpto. de Ecosistemas Agroforestales; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Instituto Agroforestal Mediterráneo; Dpto. de Química; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural; Grupo de Ingeniería Estadística Multivariante GIEMBait stations are widely used to control Ceratitis capitata, even though the effect of intrusion from untreated areas decreases the efficacy of the technique. In this work, the edge effect of outer fruit fly populations from untreated areas and backyard orchards has been studied. For this purpose, a field trial was carried out during four years in a wide area of 10 000 ha located in Valencia (Spain). The main growing species were Prunus persica, Prunus domestica, Citrus sinensis, Citrus reticulata and Diospyros kaki. An area of 3,600 ha was treated with chemosterilant bait stations. Fruit fly populations were monitored during the 4 years of study inside and outside the treated area using Tephri-traps baited with trimedlure. A grid of 180 traps was placed in the field with an intertrap distance of 450 m. Multiple linear regression was applied to model population levels as a function of distance to untreated areas and backyards. The distance at which outer medfly populations influenced the treated wide-area population was about 1.3 km. This value reflects the distance at which a given fruit fly population is influenced by outer populations and suggests that C. capitata is able to move more than 1 km seeking for hosts. Thus, buffer areas in area-wide integrated pest management of Mediterranean fruit fly should be at least 1.3 km wide.
- PublicationA methodology for discriminant time series analysis applied to microclimate monitoring of fresco paintings(MDPI AG, 2021-01) Ramírez, Sandra; Zarzo Castelló, Manuel; Perles Ivars, Ángel Francisco; García Diego, Fernando Juan; Dpto. de Física Aplicada; Dpto. de Informática de Sistemas y Computadores; Instituto Universitario de Tecnologías de la Información y Comunicaciones; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería del Diseño; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM; Centro de Investigación en Acuicultura y Medio Ambiente; Pontificia Universidad Javeriana; COMISION DE LAS COMUNIDADES EUROPEA; Instituto Colombiano de Crédito Educativo y Estudios Técnicos en el Exterior[EN] The famous Renaissance frescoes in Valencia¿s Cathedral (Spain) have been kept under confined temperature and relative humidity (RH) conditions for about 300 years, until the removal of the baroque vault covering them, carried out in 2006. In the interest of longer-term preservation and in order to maintain these frescoes in good condition, a unique monitoring system was implemented to record both air temperature and RH. Sensors were installed in different points at the vault of the apse, during the restoration process. The present study proposes a statistical methodology for analyzing a subset of RH data recorded in 2008 and 2010, from the sensors. This methodology is based on fitting different functions and models to the time series, in order to classify the sensors. The methodology proposed, computes classification variables and applies a discriminant technique to them. The classification variables correspond to estimates of parameters of the models and features such as mean and maximum, among others. These features are computed using values of the functions such as spectral density, sample autocorrelation (sample ACF), sample partial autocorrelation (sample PACF), and moving range (MR). The classification variables computed were structured as a matrix. Next, Sparse Partial Least Squares Discriminant Analysis (sPLS-DA) was applied in order to discriminate sensors according to their position in the vault. It was found that the classification of sensors derived from Seasonal ARIMA-TGARCH showed the best performance (i.e., lowest classification error rate). Based on these results, the methodology applied here can be useful for characterizing the differences in RH, measured at different positions in a historical building.
- PublicationWhat is a fresh scent in perfumery? Perceptual freshness iscorrelated with substantivity(MDPI, 2013-01) Zarzo Castelló, Manuel; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEMPerfumes are manufactured by mixing odorous materials with different volatilities. The parameter that measures the lasting property of a material when applied on the skin is called substantivity or tenacity. It is well known by perfumers that citrus and green notes are perceived as fresh and they tend to evaporate quickly, while odors most dissimilar to fresh (e.g., oriental, powdery, erogenic and animalic scents) are tenacious. However, studies aimed at quantifying the relationship between fresh odor quality and substantivity have not received much attention. In this work, perceptual olfactory ratings on a fresh scale, estimated in a previous study, were compared with substantivity parameters and antierogenic ratings from the literature. It was found that the correlation between fresh odor character and odorant substantivity is quite strong (r = −0.85). Fresh is sometimes interpreted in perfumery as cool and the opposite of warm . This association suggests that odor freshness might be somehow related to temperature. Assuming that odor perception space was shaped throughout evolution in temperate climates, results reported here are consistent with the hypothesis that fresh evokes scents typically encountered in the cool season, while warm would be evoked by odors found in nature during summer. This hypothesis is rather simplistic but it may provide a new insight to better understand the perceptual space of scents.
- PublicationExégesis del "mar vítreo" entreverado de fuego" (Ap 15,2): posible interpretación como el cáliz eucarístico(Universidad Católica del Norte, 2018) Zarzo Castelló, Manuel; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM[EN] revelation 15:2 mentions ¿a kind of sea of glass mingled with fire¿. The expression ¿a kind of sea¿ suggests a figurative sense, perhaps in reference to the Sea of Bronze of the ancient Temple (1 Kings 7:24-25), a huge hemispherical water tank called sea in the Old Testament. When the Apocalypse was written, it was customary for Christian communities from Jewish tradition to celebrate the Eucharist with the Jewish blessing cup reserved for Easter, inherited from previous generations. These cups were often made of semiprecious stone and were shaped like a bowl, which might justify their analogy with the sea. Moreover, some were translucent and veined if carved in agate, onyx or sardonyx, as is the case of the Holy Chalice venerated at Valencia Cathedral or some chalices at St Mark¿s Basilica Museum in Venice. The sacred author might refer to a Eucharistic cup carved in stone in Rev 15:2, in relation to another ¿sea of glass¿ mentioned in Rev 4:6 that could allude to the baptismal font, and, as an antagonism to the ¿great winepress of God¿s wrath¿ (14:19).
- PublicationEffect of functional group and carbon chain length on the odor detection threshold of aliphatic compounds(MDPI, 2012-04) Zarzo Castelló, Manuel; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM; Ministerio de Educación y CienciaOdor detection thresholds (ODTs) are used for assessing outdoor and indoor air quality. They are obtained experimentally by olfactometry and psychophysical methods, and large compilations are available in the literature. A non-linear regression equation was fitted to describe the ODT variability of 114 aliphatic compounds based on the alkyl chain length for different homologous series (carboxylic acids, aldehydes, 2-ketones, esters, 1-alcohols, amines, thiols, thioethers and hydrocarbons). The resulting equation reveals an effect of the functional group, molecular size and also an interaction between both factors. Although the mechanistic interpretation of results is uncertain, the relatively high goodness-of-fit (R 2 = 0.90) suggests that ODT values of aliphatic compounds can be predicted rather accurately, which is not the case for rigid molecules. This equation may serve as a basis for the development of more complex ODT models taking into account diverse structural features of odorants. The variability of power-law exponents was also investigated for the homologous series. © 2012 by the authors; licensee MDPI, Basel, Switzerland.
- PublicationDiagnosis of abnormal patterns in multivariate microclimate monitoring: a case study of an open-air archaeological site in Pompeii (Italy)(Elsevier, 2014-08-01) Merello Giménez, Paloma; García Diego, Fernando Juan; Zarzo Castelló, Manuel; Dpto. de Física Aplicada; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM; Centro de Investigación en Acuicultura y Medio Ambiente; Ministerio de Ciencia e InnovaciónChemometrics has been applied successfully since the 1990s for the multivariate statistical control of industrial processes. A new area of interest for these tools is the microclimatic monitoring of cultural heritage. Sensors record climatic parameters over time and statistical data analysis is performed to obtain valuable information for preventive conservation. A case study of an open-air archaeological site is presented here. A set of 26 temperature and relative humidity data-loggers was installed in four rooms of Ariadne's house (Pompeii). If climatic values are recorded versus time at different positions, the resulting data structure is equivalent to records of physical parameters registered at several points of a continuous chemical process. However, there is an important difference in this case: continuous processes are controlled to reach a steady state, whilst open-air sites undergo tremendous fluctuations. Although data from continuous processes are usually column-centred prior to applying principal components analysis, it turned out that another pre-treatment (row-centred data) was more convenient for the interpretation of components and to identify abnormal patterns. The detection of typical trajectories was more straightforward by dividing the whole monitored period into several sub-periods, because the marked climatic fluctuations throughout the year affect the correlation structures. The proposed statistical methodology is of interest for the microclimatic monitoring of cultural heritage, particularly in the case of open-air or semiconfined archaeological sites.
- PublicationMultivariate analysis of olfactory profiles for 140 perfumes as a basis to derive a sensory wheel for the classification of feminine fragrances(MDPI AG, 2020-02) Zarzo Castelló, Manuel; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Escuela Técnica Superior de Ingeniería Informática; Grupo de Ingeniería Estadística Multivariante GIEM[EN] In order to guide consumers in their purchase of a new fragrance, one approach is to visualize the spectrum of men's or women's fragrances on a two-dimensional plot. One of such sensory maps available is the Hexagon of Fragrance Families. It displays 91 women's perfumes inside a polygon, so that each side accounts for a different olfactory class. In order to discuss this chart, odor profiles were obtained for these fragrances and additional feminine ones (140 in total, launched from 1912 to 1990). An olfactory dataset was arranged by coding numerically the descriptions obtained from Fragrantica and Osmoz websites, as well as from a perfume guide. By applying principal component analysis, a sensory map was obtained that properly reflected the similarities between odor descriptors. Such representation was equivalent to the map of feminine fragrances called Givaudan Analogies, comprised of five major categories. Based on the results, a modified version of the Hexagon based on 14 categories was proposed. The first principal component explained preference for daytime versus nighttime wear, and regression models were fitted in order to estimate such preferences according to the odor profiles. The second component basically discriminated floral versus chypre (mossy-woody) fragrances. Results provide a fundamental basis to develop standard sensory maps of women's fragrances.
- PublicationEffect of sex pheromone emission on the attraction of Lobesia botrana(Wiley, 2011-06) Vacas González, Sandra; Alfaro Cañamás, Cristina; Zarzo Castelló, Manuel; Navarro Llopis, Vicente; Primo Millo, Jaime; Dpto. de Ecosistemas Agroforestales; Dpto. de Estadística e Investigación Operativa Aplicadas y Calidad; Instituto Agroforestal Mediterráneo; Dpto. de Química; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Informática; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural; Grupo de Ingeniería Estadística Multivariante GIEMSince the discovery of Lobesia botrana Denis & Schiffermüller (Lepidoptera: Tortricidae) sex pheromone, it has played an important role in the control and detection of this pest, for example, through the use of pheromone-baited traps and mating disruption techniques. Rubber septa are the most common pheromone dispensers used in monitoring traps, but often dispenser performance is not optimized. The key to improve methods based on pheromones as attractants (monitoring, mass trapping, or ‘attract and kill’) is to know the optimum emission interval, because release rates can strongly affect the attraction. In this work, five levels of pheromone load with different release rates were compared in traps using mesoporous pheromone dispensers to investigate the optimum release rate maximizing L. botrana catches. Residual pheromone loads of the dispensers were extracted and quantified by gas chromatography, to study release profiles and to estimate the various emission levels. The efficacy of pheromone emission was measured in field trials as number of moths caught. A quadratic model was fitted to relate the numbers caught vs. the daily emission rates. The resulting quadratic term was statistically significant, confirming the existence of a relative maximum for L. botrana catches. Taking into account that the trial was carried out only in one location, an optimum emission value of ca. 400 μg per day could be considered to enhance the attraction of L. botrana under West-Mediterranean weather conditions.© 2011 The Authors. Entomologia Experimentalis et Applicata © 2011 The Netherlands Entomological Society.