Proper losses for discrete generative models

We initiate the study of proper losses for evaluating generative models in the discrete setting. Unlike traditional proper losses, we treat both the generative model and the target distribution as black-boxes, only assuming ability to draw i.i.d. samples. We define a loss to be black-box proper if the generative distribution that minimizes expected loss is equal to the target distribution. Using techniques from statistical estimation theory, we give a general construction and characterization of black-box proper losses: they must take a polynomial form, and the number of draws from the model and target distribution must exceed the degree of the polynomial. The characterization rules out a loss whose expectation is the cross-entropy between the target distribution and the model. By extending the construction to arbitrary sampling schemes such as Poisson sampling, however, we show that one can construct such a loss

Medindo a sustentabilidade na aquicultura

Atualmente há uma forte preocupação por parte da sociedade em se respeitar os preceitos da sustentabilidade nos sistemas, incluindo a produção de alimentos. No entanto, diversas são as definições para o termo sustentável, em decorrência de sua concepção sobre o grau de importância dado à economia e meio ambiente. Consequentemente, vários são os métodos elaborados e usados para avaliar a sustentabilidade. Alguns deles foram desenvolvidos exclusivamente para a aquicultura, enquanto outros são aplicações de métodos gerais em sistemas aqüícolas. Apresentaremos aqui uma breve descrição dessas metodologias e suas aplicações nos sistemas de aqüicultura.Fil: Kimpara, Janaina M.. Universidade Federal Do Espirito Santo; Brasil. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Zajdband, Ariel David. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valenti, Wagner C.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Mitigation of Torque Ripple and Vibration in Switched Reluctance Motor Drives: A Switching Optimization

Switched reluctance motor (SRM) drives represents an attractive solution for industrial, transportation and domestic applications due to their rugged structure, independence from rare earth metals, modular design, wide speed range, and tolerance to harsh environments. Despite these advantages, the adequacy of SRM drives for many applications has been overshadowed by its relative high levels of torque pulsation and vibration/acoustic noise. This research aims to investigate and propose control strategies to mitigate these adverse features. To reach this goal the current shaping and switching optimization have been proposed. Two modeling methods were used in this process: i) field reconstruction method (FRM) to model the electromagnetic behavior; and ii) mechanical impulse response to model the structural behavior. This two-modeling procedure are the key innovative tools in this dissertation, since those are techniques recently proposed in the literature. Moreover, these two methods have been combined to simultaneously mitigation of torque ripple and radial vibration. Firstly, the structural vibration was investigated in detail for an 8/6 SRM. The modal analysis is carried out experimentally and through finite element model in ANSYS. Then, the mechanical impulse response concept was applied to develop a vibration prediction model that, after validated, was introduced in an optimization algorithm developed in MATLAB to design the precise switching instants to have active vibration cancellation. The method is focused on SRM operating under current control (low speed region). The experimental results show a significantly reduction. This technique is sensitive to timing without adverse impact on productivity and efficiency of the SRM drive. Moreover, the vibration mitigation also has contributed to acoustic noise reduction. In a second approach, an optimization based on the SRM model using the FRM is used to find the optimal current profile that mitigates the torque ripple. The percentage reduction reached is about 44%. Furthermore, the effect of the new current profile in the structural response is also investigated and a negative impact in the vibration has been observed. To deal with this shortcoming, an adaptive hysteresis band is implemented over the optimized current profile for torque ripple mitigation. The obtained results demonstrated a good compromise between the torque ripple and vibration mitigation

Effect of cast rectifiers on the marginal fit of UCLA abutments

OBJECTIVES: This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated. METHODS: Two groups were analyzed: test group - 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group - 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey's test (a= 5%). RESULTS: The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68mm to 14.83mm;

Métodos para medir a sustentabilidade na aquicultura.

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Surface degradation of glass ceramics after exposure to acidulated phosphate fluoride

OBJECTIVE: This study evaluated the surface degradation effect of acidulated phosphate fluoride (APF) gel exposure on the glassy matrix ceramics as a function of time. MATERIAL AND METHODS: Disc-shaped ceramic specimens (N = 120, 10/per ceramic material) were prepared in stainless steel molds (inner diameter: 5 mm, height: 2 mm) using 6 dental ceramics: 3 indicated for ceramic-fused-to-metal (Vita Omega 900, Carmen and Vita Titankeramik), 2 for all-ceramic (Vitadur Alpha and Finesse® Low Fusing) and 1 for both types of restorations (IPS d.SIGN). The specimens were wet ground finished, ultrasonically cleaned and auto-glazed. All specimens were subjected to calculation of percentage of mass loss, surface roughness analysis and topographical description by scanning electron microscopy (SEM) before (0 min) and after exposure to 1.23 % APF gel for 4 min and 60 min representing short- and long-term etching effect, respectively. The data were analyzed using two-way ANOVA with repeated measures and Tukey's test (a=0.05). RESULTS: Significant effect of the type of the ceramics (p=0.0000, p=0.0031) and exposure time (p=0.0000) was observed in both surface roughness and percentage of mass loss values, respectively. The interaction factor between both parameters was also significant for both parameters (p=0.0904, p=0.0258). Both 4 min (0.44±0.1 - 0.81±0.2 mm) and 60 min (0.66±0.1 - 1.04±0.3 mm) APF gel exposure created significantly more surface roughness for all groups when compared to the control groups (0.33±0.2 - 0.68±0.2 mm) (p;0.05) but at 60 min exposure, IPS d.SIGN showed the highest percentage of mass loss (0.1151±0.11). The mean surface roughness for Vita Titankeramik (0.84±0.2 mm) and Finesse® Low Fusing (0.74.±0.2 mm) was significantly higher than those of the other ceramics (0.59±0.1 mm - 0.49±0.1 mm) and Vita Titankeramik (

A bioeconomic analysis of the potential of seaweed Hypnea pseudomusciformis farming to different targeted markets.

Simulations were performed to evaluate the economic potential of farming the seaweed Hypnea pseudomusciformis in two production scales for the carrageenan, human food, and glycolic extract markets in Brazil

Produção e beneficiamento da macroalga marinha Hypnea.

A macroalga H. pseudomusciformis é de interesse da indústria cosmética, farmacêutica e alimentícia. Ela é muito explorada para a extração da carragena, pois a possui em elevada quantidade e qualidade. Apesar da elevada exploração comercial, apenas recentemente foi desenvolvida uma técnica para o cultivo dessa macroalga.bitstream/item/222378/1/ABC-AGR-FAMILIAR-Producao-e-beneficiamento-de-macroalga-marinha-ed-01-2021-03-23-2021.pd

Sustainability of the seaweed Hypnea pseudomusciformis farming in the tropical Southwestern Atlantic.

Seaweed culture is generally referred to as a sustainable production system. Nevertheless, this concept is biased by an environmental approach only, neglecting the economic and social dimensions of sustainability. The objective of this study was to assess the sustainability of the seaweed Hypnea pseudomusciformis cultivation and its use as human food consumption. We developed a pilot farming with the Association of Algae Producers of Flecheiras and Guajiru, in the municipality of Trairi, Northeastern Brazil. We applied a set of indicators to access environmental, social, and economic dimensions of sustainability

Properties of type IV plaster considering variation in the mold/model position during setting stage

Objective: To assess the influence of the position of the mold during the setting stage of type IV stone plaster Durone (Dentsply Ind. Com., Rio de Janeiro, Brazil), on the following properties: surface hardness and roughness. Methods: For the roughness test, two groups (n=6) in the form of pellets were prepared. In the first group, the surface of the base of the device was turned down during the plaster setting stage (N), in the second group this position was inverted, which has been described as an act of capsize it (E). For analysis, a roughness meter with reading precision of 0.01 μm was used. With regard to the hardness analysis, two groups with conical-shaped samples were obtained. The plasters were left to set under the same conditions of the mold/model position described for the previous experiment. Hardness measurement was performed in a durometer with a spherical penetrating tip for Rockwell readout. Three measurements were performed for each test specimen in both tests. Results: The hardness (N - 39.8, standard deviation = 3.3, E - 30.8, standard deviation = 5.6) and roughness data (N - 0.67, standard deviation = 0.17, E - 0.74, standard deviation = 0.13) submitted to the Student’s-t test (5%) showed no statistically significant differences for the roughness test (0.489), but showed statistically significant differences for the hardness test (0.014). Conclusion: The variation in the mold/model position influenced the final characteristics of the specimens in terms of hardness, since those obtained with the capsize technique showed lower surface hardness, whereas for roughness these differences were not statistically significant