Automatic content based image retrieval using semantic analysis

We present a new text-to-image re-ranking approach for improving the relevancy rate in searches. In particular, we focus on the fundamental semantic gap that exists between the low-level visual features of the image and high-level textual queries by dynamically maintaining a connected hierarchy in the form of a concept database. For each textual query, we take the results from popular search engines as an initial retrieval, followed by a semantic analysis to map the textual query to higher level concepts. In order to do this, we design a two-layer scoring system which can identify the relationship between the query and the concepts automatically. We then calculate the image feature vectors and compare them with the classifier for each related concept. An image is relevant only when it is related to the query both semantically and content-wise. The second feature of this work is that we loosen the requirement for query accuracy from the user, which makes it possible to perform well on users’ queries containing less relevant information. Thirdly, the concept database can be dynamically maintained to satisfy the variations in user queries, which eliminates the need for human labor in building a sophisticated initial concept database. We designed our experiment using complex queries (based on five scenarios) to demonstrate how our retrieval results are a significant improvement over those obtained from current state-of-the-art image search engines.     

Performance of paint systems with polyurethane topcoats, proposed for atmospheres with very high corrosivity category

The EN ISO Standard 12944-5 describes the types of paint and paint systems commonly used for corrosion protection of steel structures. In this work four paint systems, applied on steel, including polyurethane topcoats, recommended for atmospheres with high corrosivity (C5 category), codified by 1–4, were studied. Systems 1 and 4 include zinc rich primers and epoxy/polyamide intermediates, system 2 has solvent free epoxy/polyamide primer and intermediate and, system 3 is a hybrid system with vinyl–acrylic water based primer and a high solids epoxy/polyamide intermediate. Systems 2–4 have acrylic–polyurethane topcoats and, the topcoat of the system 1 was identified as an aliphatic polyurethane.

According to EN ISO 12944-6, water condensation and neutral salt spray tests were performed. Three exposure times were considered taking into account the durability ranges of paint systems: low, medium and high, respectively. The paint systems were complementary submitted, during 30 days, to ultraviolet radiation with water condensation test according to ASTM G 154. At the same time, natural exposure was conducted in the marine atmosphere of Sines, with very high corrosivity (>C5).

The paint adhesion, before and after artificial ageing, was evaluated by cross-cut test and, for the systems with dry thickness greater than 250 μm, by pull-off test. Visual inspections were carried out.

For the exposure in UV radiation test chamber and at test site, gloss reduction, colour change and chalking were measured. Chemical changes on polyurethane topcoats exposed in the UV radiation test chamber were studied by Fourier transform infrared spectroscopy (FTIR).

In spite of the higher aesthetic degradation by UV radiation, of the aliphatic polyurethane topcoat of the system 1 relatively to the acrylic–polyurethane topcoats of the other systems, system 1 with ethyl silicate zinc rich primer and epoxy intermediate, was the one that presented the best corrosion protection when exposed in artificial and natural salty environments. At the test site, the worst anticorrosive behaviour seems to be presented by the system 2 with two coats of solvent free epoxy paint.     

Optimization of the process of drying of corn seeds with the use of microwaves

Abstract

The heating and drying of various types of food using microwave improve the economy of time and energy. The physiological quality variation of the seeds submitted to microwave drying is known to some extent. In this context, some authors have reported excellent performance using this technique, on germination rates, after drying. The commercial use of microwave drying in seeds is irrelevant, which motivates more extensive research on the benefits and challenges of this technique that can increase its insertion in the post-harvest handling steps of agricultural products. Corn is a product of high worldwide relevance. Therefore, the use of microwaves in its drying process has excellent potential to arrive at significant savings in its production. Thus, this study is aimed to evaluate the effects on the physiological quality of the seeds submitted to different drying conditions, using the microwave radiation. To that end, corn seeds, with a water content of 20% on wet basis (w.b.), were dried at 40, 50, and 60?°C, at power ratings of 0, 0.6, and 1.2?W/g; in the vacuum condition. Drying occurred continuously, with intermittent power, until the seeds reached the 12% wet basis; in this condition, the seeds could be stored with secure. Germination tests performed shortly after drying showed that the temperature of 40?°C at a power of 0.6?W/g had a reduction in drying time of approximately 5?h when compared to conventional drying (40?°C and 0.0?W/g). The evaluation of the physiological quality of the seeds showed no significant difference in the germination, vigor, and longevity indices of the treated seeds.     

Efficient generic face model fitting to images and videos

In this paper we present a robust and lightweight method for the automatic fitting of deformable 3D face models on facial images. Popular fitting techniques such as those based on statistical models of shape and appearance require a training stage based on a set of facial images and their corresponding facial landmarks, which have to be manually labeled. Therefore, new images in which to fit the model cannot differ too much in shape and appearance (including illumination variation, facial hair, wrinkles, etc.) from those used for training. By contrast, our approach can fit a generic face model in two steps: (1) the detection of facial features based on local image gradient analysis and (2) the backprojection of a deformable 3D face model through the optimization of its deformation parameters. The proposed approach can retain the advantages of both learning-free and learning-based approaches. Thus, we can estimate the position, orientation, shape and actions of faces, and initialize user-specific face tracking approaches, such as Online Appearance Models (OAMs), which have shown to be more robust than generic user tracking approaches. Experimental results show that our method outperforms other fitting alternatives under challenging illumination conditions and with a computational cost that allows its implementation in devices with low hardware specifications, such as smartphones and tablets. Our proposed approach lends itself nicely to many frameworks addressing semantic inference in face images and videos.     

Understanding the activation mechanism induced by NOx on the performances of VOx/TiO2 based catalysts in the total oxidation of chlorinated VOCs

A previous investigation of the chlorobenzene combustion activity of VO_x/TiO₂, VO_x–WO_x/TiO₂ and VO_x–MoO_x/TiO₂ catalysts in the presence of NO pointed out the activation effect of NO. The suggested three-step mechanism based on catalytic performances data only was: (1) chlorobenzene is oxidized on the surface of the VO_x phase (as described by Mars–van Krevelen), (2) NO gets oxidized to NO₂, mainly on WO_x and MoO_x, and (3) the in situ produced NO₂ assists O₂ in the reoxidation of the VO_x phase thus speeding up the oxidation step of the Mars–van Krevelen mechanism. The latter effect macroscopically corresponds to the observed increase of chlorobenzene conversion. This contribution aims at validating this hypothetical mechanism by pointing out the favourable occurrence of an oxidation of NO to NO₂ on the WO_x and MoO_x phases and by pointing out the higher efficiency of NO₂ than O₂ to reoxidize the reduced VO_x sites. In addition, the present contribution clearly demonstrates that, in the absence of NO, the chlorobenzene total oxidation occurred following the Mars–van Krevelen mechanism. Moreover, a thorough characterization of the oxidation state of the vanadium proving that the improvement of the catalyst activity brought by the simultaneous presence of NO and O₂ is linked to the stronger reoxidation of the VO_x active phase. Furthermore, plotting all the catalytic activity data versus the mean vanadium oxidation level clearly depicts, for the first time, the strong dependence between them. Under a mean vanadium oxidation level of 4.82 the catalyst is inactive while above 4.87 the activity is stabilized at a high level of conversion independent of the vanadium oxidation level.     

Origins of the Rio Capim kaolinites (northern Brazil) revealed by δO and δD analyses

Deuterium (δD) and oxygen (δ¹⁸O) isotope data from the Rio Capim kaolin, northern Brazil, were combined with optical studies in order to better understand the genesis and evolution of the kaolinites. The results show that δ¹⁸O values from a lower soft kaolin unit range from 6.0‰ to 19.2‰ for Ka (size ranging from 1 to 3 μm) and Kb (size ranging from 10 to 30 μm) kaolinites, and from 15.4‰ to 24.9‰ for Kc (size < 200 nm) kaolinites. The δD values range from − 63.1‰ to 79.5‰ for the Ka + Kb kaolinites, and from − 68.8‰ to − 244.35‰ for the Kc kaolinites. An upper semi flint kaolin unit, dominated by Kc kaolinites, displays δ¹⁸O and δD values ranging from 15.1‰ to 21.8‰, and − 71.3‰ to − 87.4‰, respectively. Based on these data, and on the δ¹⁸O and δD values obtained for the surface meteoric water and groundwater, it can be concluded that the kaolinites are not in equilibrium with the modern weathering environment, but they reflect isotopic compositions of the formation time, probably due to the interaction with fossil groundwater. However, mineralogical contaminations derived from replacements of framework grains also had great influence in the isotopic composition of these kaolinites. In addition, the isotope values of the Kc kaolinites from the semi-flint kaolin unit is variable, which is due to the presence of Kc kaolinites of different origins, including kaolinites derived from the underlying soft kaolin unit, kaolinites formed during different phases of paleoweathering, as well as later phases of coarse-grained kaolinites formed along fractures. Due to these complexities, binary diagrams contrasting δ¹⁸O and δD values, worldwide applied for distinguishing supergenic from hypogenic kaolinites, as well as those formed under weathering conditions, can not be applied to interpret the origin of the kaolinites in the Rio Capim Kaolin.     

Kinetic approach on stabilization of LDPE in the presence of carnosic acid and related compounds. I. Thermal investigation

Carnosic acid and similar compounds exhibit antioxidant behavior in a polyethylene matrix. Thermal resistance of LDPE was investigated at three temperatures (190, 200, and 210°C) by isothermal chemiluminescence. The main kinetic parameters: oxidation induction period (t_i), half oxidation time (t_1/2), maximum oxidation time (t_max), and propagation rate of oxidation (v_ox^max) were calculated. The inhibition of thermal degradation is proved by the values of these parameters relative to unstabilized polymer: the induction times of stabilized low density polyethylene are of one order of magnitude greater that raw polyethylene, and half oxidation periods are three to five times longer than initial LDPE. Thermal aging of protected low density polyethylene occurs at a much slower rate in comparison with unmodified LDPE. The depletion of stabilizers was also evaluated and the kinetic characteristics (the half‐life and the rate constant of consumption for each antioxidant) at three concentrations of all tested additives (0.125, 0.25, 0.50, and 0.75% w/w) were determined. The effectiveness of stabilization was depicted by two values of activation energies calculated from oxidation induction times and maximum oxidation periods. Some considerations on stabilizing mechanism are presented. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1571–1577, 2005     

Study of the influence of the reaction parameters on the composition of the metallocene‐catalyzed ethylene copolymers using temperature rising elution fractionation and 13C nuclear magnetic resonance

Polyethylene copolymers prepared using the metallocene catalyst rac‐Et[Ind]₂ZrCl₂ were fractionated by preparative Temperature Rising Elution Fractionation (p‐TREF) and characterized by ¹³C nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) to study the heterogeneity caused by experimental conditions. Two ethylene–1‐hexene copolymers with different 1‐hexene content and an ethylene–1‐octene copolymer all obtained using low (1.6 bar) ethylene pressure were compared with two ethylene–1‐hexene copolymers with different 1‐hexene content obtained at high ethylene pressure (7.0 bar). Samples obtained at low ethylene pressure and with low 1‐hexene concentration in the reactor presented narrow distributions in composition. Samples prepared with high comonomer concentration in the reactor or with high ethylene pressure showed an heterogeneous composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 155–163, 2002; DOI 10.1002/app.10284     

Partial oxidation of methane to carbon monoxide and hydrogen in a fluidized bed reactor

A fluidized bed reactor has been used to investigate the partial oxidation of methane to syngas over a NiO/NiAl₂O₄ catalyst. The axial concentration profiles of the different species along the bed have been determined and related to the observed temperature profiles. The amount of carbon deposited on the catalyst under different operating conditions has also been determined. The results show that under suitable conditions, the bubbling fluidization regime gives a stable reactor performance with high conversion and selectivity, and a limited amount of carbon formation.     

A Transformation-Based Approach to Business Process Management in the Cloud

Business Process Management (BPM) has gained a lot of popularity in the last two decades, since it allows organizations to manage and optimize their business processes. However, purchasing a BPM system can be an expensive investment for a company, since not only the software itself needs to be purchased, but also hardware is required on which the process engine should run, and personnel need to be hired or allocated for setting up and maintaining the hardware and the software. Cloud computing gives its users the opportunity of using computing resources in a pay-per-use manner, and perceiving these resources as unlimited. Therefore, the application of cloud computing technologies to BPM can be extremely beneficial specially for small and middle-size companies. Nevertheless, the fear of losing or exposing sensitive data by placing these data in the cloud is one of the biggest obstacles to the deployment of cloud-based solutions in organizations nowadays. In this paper we introduce a transformation-based approach that allows companies to control the parts of their business processes that should be allocated to their own premises and to the cloud, to avoid unwanted exposure of confidential data and to profit from the high performance of cloud environments. In our approach, the user annotates activities and data that should be placed in the cloud or on-premise, and an automated transformation generates the process fragments for cloud and on-premise deployment. The paper discusses the challenges of developing the transformation and presents a case study that demonstrates the applicability of the approach.