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101.
Luana Batista Luis Da Costa Said Berriah Helmut Lademann 《Expert systems with applications》2013,40(8):3128-3136
The Chlor-Alkali production is one of the largest industrial scale electro-synthesis in the world. Plants with more than 1000 individual reactors are common, where chlorine and hydrogen are only separated by 0.2 mm thin membranes. Wrong operating conditions can cause explosions and highly toxic gas releases, but also irreversible damages of very expensive cell components with dramatic maintenance costs and production loss. In this paper, a Multi-Expert System based on first-order logic rules and Decision Forests is proposed to detect any abnormal operating conditions of membrane cell electrolyzers and to advice the operator accordingly. Robustness to missing data – which represents an important issue in industrial applications in general – is achieved by means of a Dynamic Selection strategy. Experiments performed with real-world electrolyzer data indicate that the proposed system can significantly detect the different operating modes, even in the presence of high levels of missing data – or “wrong” data, as a consequence of maloperation –, which is essential for precise fault detection and advice generation. 相似文献
102.
L.A. Bezerra M.M. Oliveira T.L. Rolim A. Conci F.G.S. Santos P.R.M. Lyra R.C.F. Lima 《Signal processing》2013,93(10):2851-2863
The major goal of this paper is to help detect breast cancer early based on infrared images. Some procedures, protocols and numerical simulations were developed or performed. Two different issues are presented. The first is the development of a standardized protocol for the acquisition of breast thermal images including the design, construction and installation of mechanical apparatus. The second part is related to the greatest difficulty for the numerical computation of breast temperature profiles that is caused by the uncertainty of the real values of the thermophysical parameters of some tissues. Then, a methodology for estimating thermal properties based on these infrared images is presented. The commercial software FLUENTTM was used for the numerical simulation. A Sequential Quadratic Programming (SQP) method was used to solve the inverse problem and to estimate the thermal conductivity and blood perfusion of breast tissues. The results showed that it is possible to estimate the thermophysical properties using the thermography. The next stage will be to use the geometry of a real breast for the numerical simulation in conjunction with a linear mapping of the temperatures measured over the breast volume. 相似文献
103.
E. R. Bezerra de Mello 《Gravitation and Cosmology》2010,16(2):92-104
We analyze vacuum polarization effects associated with massive scalar quantum fields in a higher-dimensional de Sitter space
in the presence of a global monopole. Because this analysis has been developed in pure de Sitter space, we are mainly interested
on the effects induced by the presence of the global monopole. So, to achieve this objective, we calculate the corresponding
Wightman function, which is expressed in an integral representation and explicitly depends on the parameters associated with
the presence of the monopole and the cosmological constant. Admitting that the former is closed to unity, which corresponds
to a realistic value predicted by Grand Unified Theories, it is possible to express this function as a sum of two terms: the
first one corresponds to the Wightman function on the bulk where the global monopole is absent, and the second one is a contribution
induced by the presence of the monopole. 相似文献
104.
Rodolfo Florence Teixeira Jr. Flavio Cesar Faria Fernandes Néocles Alves Pereira 《Computers & Industrial Engineering》2010
This paper describes the development and solution of binary integer formulations for production scheduling problems in market-driven foundries. This industrial sector is comprised of small and mid-sized companies with little or no automation, working with diversified production, involving several different metal alloy specifications in small tailor-made product lots. The characteristics and constraints involved in a typical production environment at these industries challenge the formulation of mathematical programming models that can be computationally solved when considering real applications. However, despite the interest on the part of these industries in counting on effective methods for production scheduling, there are few studies available on the subject. The computational tests prove the robustness and feasibility of proposed models in situations analogous to those found in production scheduling at the analyzed industrial sector. 相似文献
105.
Teresa G. Pereira Irineu Batista Narcisa M. Bandarra Júlia Ferreira Nuno Fradinho Fernando Afonso 《International Journal of Food Science & Technology》2013,48(6):1303-1308
The main objective of this study was to compare the proximate chemical composition and fatty acid profile of migrating allis shad (MS) and resident allis shad (RS) and to evaluate the nutritional value of fried migrating allis shad. No significant differences in the proximate chemical composition between males and females of each stock were obtained. However, MS fish had a significantly higher fat content than RS fish. The monounsaturated fatty acids group was the dominant in MS fish and oleic acid presented the highest percentage. Docosahexaenoic acid followed by eicosapentaenoic acid were the main PUFA in fish from both stocks. However, RS fish had higher total ω6 than MS fish due to its higher percentage of linoleic acid and arachidonic acid. Frying resulted in a significant reduction in water content and affected significantly the proximate chemical composition and the fatty acid profile, particularly the palmitic, oleic and linoleic acid. 相似文献
106.
Cristhiane C. Ferrari Javier R. Arballo Rodolfo H. Mascheroni Miriam D. Hubinger 《International Journal of Food Science & Technology》2011,46(2):436-443
The influence of vacuum time and solution concentration on mass transfer and mechanical properties of osmodehydrated melon cubes has been studied. Pulsed vacuum osmotic dehydration (PVOD) was carried out at 30 °C for 4 h, using sucrose solutions (40, 50 or 60°Brix) and applying a vacuum pulse (100 mbar for 5, 10 or 15 min). Kinetics of water loss, solid gain and stress at rupture were analysed, as well as effective diffusivities using the hydrodynamic model. The increase in solution concentration favoured water removal, but no significant effect of vacuum time was observed. The use of less concentrated solutions coupled to the action of vacuum pulse resulted in greater solid uptake. Samples subjected to PVOD using 60°Brix sucrose solution presented greater water loss, lower sugar uptake and better maintenance of fresh fruit texture throughout the process. Diffusion coefficients estimated by the hydrodynamic model showed a good fit to the experimental data. 相似文献
107.
J.P. Nobre A.C. Batista L. Coelho A.M. Dias 《Journal of Materials Processing Technology》2010,210(15):2285-2291
Two experimental methods to characterize the mechanical behavior of work-hardened surface layers of metallic materials, induced by mechanical surface treatments, are described and discussed. The study was conducted using two steels with different mechanical properties, subjected to a similar shot-peening treatment. To characterize the elastic–plastic behavior of the surface layers affected by shot-peening, the X-ray diffraction assisted four-point bending method (XRDABM) and the normalized hardness variation method (NHVM) were applied. The results were compared and discussed taking into account the advantages and disadvantages of both methods. Similar yield strength values of the treated surfaces were found by both proposed methods. Taking into account their measuring characteristics, these can be considered complementary methods. 相似文献
108.
K. S. Rodolfo A. T. Arguden R. U. Solidum J. V. Umbal 《Bulletin of Engineering Geology and the Environment》1989,40(1):55-66
Mayon Volcano in the Philippines, one the world's most active, is situated in a moist, tropical-maritime climate with frequent typhoons. A third of Mayon's eruptions generate destructive lahars (volcanic debris flows and hyperconcentrated streamflows). Lahars also occur during quiescent periods when monsoons and typhoons deliver rains of appropriate intensity and duration to the loose debris on the volcano slopes. Both eruption- and post-eruptive lahars occur most frequently during the typhoon-prone October–December season of the Northeast Monsoon. Post-eruptive lahars, the most poorly documented, are exemplified by a debris-flow event triggered by Saling, a typhoon of only moderate intensity, that occurred in Mabinit Channel on the southeast Mayon flank on October 17–18, 1985, one year after the last Mayon eruption. Detailed pre- and post-Saling surveys docment channel deepening of up to 4 m and maximum lateral erosion of 66 m. The debris flows left prominent, discontinuous multi-level terraces along the length of Mabinit Channel, either from pulsations due to temporary channel blockage, or as levee deposits. A significant volume of debris overtopped channel bends at 250–200 m elevations, coalescing to cover a 200,000 m2 area of 4.5° slope with bouldery lateral deposits 1 m thick on the average. Channelized flows below this level plugged 0.5 km of the original channel and replaced it with a new conduit of comparable size. The Saling debris-flow deposits have a remarkably uniform sand-silt mode and less prominent, more variable modes in the pebble-boulder range. Shear strengths of the lateral flows ranged from 0.46×104 to 2.32×104 dn cm?2; those of the channelized flows at the plug were significantly higher. Reconstructed flow velocity was 3.8 m sec?1. 相似文献
109.
The aim of this paper is to obtain an explicit expression, instead of using a recursive method, for the nth term coefficient of the generalized Baker–Campbell–Hausdorff–Dynkin (gBCHD) formula. The gBCHD formula has been applied to control theory, specially to nonholonomic motion planning. 相似文献
110.
Cristiano Araujo Millena Gomes Edna Barros Sandro Rigo Rodolfo Azevedo Guido Araujo 《Design Automation for Embedded Systems》2005,10(4):253-283
This paper[3.5pc] presents the Platform Designer (PD) framework, a set of SystemC based tools that provide support for modeling,
simulation and analysis of multiprocessor SoC platforms (MPSoC), at different abstraction levels. PD provides mechanisms for
interconnection specification, process synchronization and communication, thus allowing the modeling of a complete platform,
in a unified environment. To do that it uses an extension of the ArchC ADL and acsys, a tool that enables the automatic generation
of a SystemC simulator of the platform. The main advantages of this approach are twofold. First, designers have more flexibility
since they can integrate and configure different processors to the platform, using a single environment. Second, it enables
a faster design space exploration, given that it automatically generates SystemC simulators of whole platforms at distinct
abstraction levels. A number of platform variations can be tried out with minor design changes, thus reducing design time.
Experimental results show the suitability of the platform simulator for design space exploration. Real applications (with
medium complexity) run in the platform in few minutes. Combined with the facility to generate platforms with minor changes,
this feature allows an improvement of the design space exploration. 相似文献