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91.
Van
o B. Litovski Ivan V. Litovski Mark Zwoliski 《International Journal of Circuit Theory and Applications》2004,32(6):487-507
Fault simulation is an essential tool for developing test patterns for circuits. Because the potential number of faults in a circuit is potentially very large, computational efficiency is an important consideration. In the digital domain, concurrent fault simulation is well‐established as an efficient tool. For analogue circuits, fault simulation is often performed by repeated insertion of possible faults and resimulation of the circuit. Consequently, methods for efficient concurrent analogue fault simulation are attracting attention. A review of existing methods of concurrent analogue fault simulation shows that most are based on a similar fundamental perturbation of the original fault‐free circuit equations, although the methods differ in the procedure applied after the circuit equations are formulated. We develop here a comprehensive set of element stamps, describing faulty elements, enabling effective and routine equation formulation for faulty circuits. These may be used no matter what method of fault simulation is later applied. These stamps are used in a new technique for concurrent analogue fault simulation, based on modified nodal analysis. A significant improvement in efficiency, compared with other methods, is demonstrated. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
92.
D. Alisantoso L.P. Khoo B.H. Ivan Lee S.C. Fok 《The International Journal of Advanced Manufacturing Technology》2005,26(5):427-435
The inherent dynamic relationships among design tasks performed concurrently at different organizations characterize the complexities of a design chain where designers with diverse expertise need to collaborate across organizational boundaries. To ensure timely completion of inter-related design tasks, metrics to facilitate the early evaluation of design concepts are crucial. The ability to evaluate and select suitable design concepts at an early stage will ensure better solutions and greater savings in time and effort further downstream. This paper proposes a new approach based on the rough set theory to design concept analysis. The approach aims at early detection of design inadequacy. A so-called information system is constructed using the information gleaned from design concepts and design capabilities, and analyzed using the rough set theory to derive a set of design rules for design concept analysis. The approach embodies a technique for handling attributes with unavailable information, which is a frequent occurrence in design. This paper presents details of the proposed approach, the novel technique, and a case study. 相似文献
93.
Richard Thomas Lermen Ivan Guerra Machado 《Journal of Materials Processing Technology》2012,212(11):2371-2379
The main objectives of this study were to construct a plasma generator device and to investigate its applications in welding, cutting, and surface hardening. The device was derived from the union of two plasma-generating technologies, non-transferred-arc plasma and magnetoplasmadynamic thruster (MPDT), and characterised by the simultaneous formation of two plasma arcs in one device, generating a plasma jet with high energy density. Initially, trials were conducted to analyse the influence of the physical variables (gas flow rate and electric current intensities – primary and secondary) on the plasma jet, for which the thruster and the length of the plasma jet expulsed from the chamber were determined. The relevant parameters for welding, cutting and surface hardening were determined by trial and error, in which the trials were conducted using various plate thicknesses and materials. The results have shown that this device can be used for welding, cutting and surface hardening. 相似文献
94.
Ivan Rodero David Villegas Norman Bobroff Yanbin Liu Liana Fong S. Masoud Sadjadi 《Journal of Grid Computing》2013,11(2):311-336
The goal of Grid computing is to integrate the usage of computer resources from cooperating partners in the form of Virtual Organizations (VO). One of its key functions is to match jobs to execution resources efficiently. For interoperability between VOs, this matching operation occurs in resource brokering middleware, commonly referred to as the meta-scheduler or meta-broker. In this paper, we present an approach to a meta-scheduler architecture, combining hierarchical and peer-to-peer models for flexibility and extensibility. Interoperability is further promoted through the introduction of a set of protocols, allowing meta-schedulers to maintain sessions and exchange job and resource state using Web Services. Our architecture also incorporates a resource model that enables an efficient resource matching across multiple Virtual Organizations, especially where the compute resources and state are dynamic. Experiments demonstrate these new functional features across three distributed organizations (BSC, FIU, and IBM), that internally use different job scheduling technologies, computing infrastructure and security mechanisms. Performance evaluations through actual system measurements and simulations provide the insights on the architecture’s effectiveness and scalability. 相似文献
95.
Michal Pluhacek Roman Senkerik Ivan Zelinka 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2014,18(4):631-639
In this paper, the utilization of different chaotic systems as pseudo-random number generators (PRNGs) for velocity calculation in the PSO algorithm are proposed. Two chaos-based PRNGs are used alternately within one run of the PSO algorithm and dynamically switched over when a certain criterion is met. By using this unique technique, it is possible to improve the performance of PSO algorithm as it is demonstrated on different benchmark functions. 相似文献
96.
This article reports an extraction–purification of napins from an industrial rapeseed meal and the assessment of their antimicrobial activity against Fusarium langsethiae. The best extraction conditions are observed at pH 2, 12% (w/w) of rapeseed meal after 15 min of extraction in water at room temperature. Under these conditions the extraction is highly selective, allowing a simple purification process (ammonium sulfate precipitation followed by desalting size exclusion chromatography) to get purified napins. These napins possessed significant anti-Fusarium activity (IC50 = 70 μM) and a compact secondary structure rich in α-helix, which may explain this bioactivity. 相似文献
97.
Oswaldo Burciaga-DiazJose Ivan Escalante-Garcia Alexander Gorokhovsky 《Cement and Concrete Composites》2012,34(1):18-24
A coarse mineral with 70% kaolinite and 30% quartz was calcined and chemically activated by alkaline solutions of Na2SiO3 and NaOH. The compressive strength evolution was investigated as a function of the curing temperature at 20 and 80 °C, and the molar ratios of SiO2/Al2O3 (2.64-4.04) and Na2O/Al2O3 (0.62-1.54). For curing at 20 °C, the best composition was SiO2/Al2O3 = 2.96 and NaO/Al2O3 = 0.62, reaching 85 MPa at 28 days. Curing at 80 °C had a positive effect on the strength development only in the first 3 days. X-ray diffraction of the geopolymeric formulations showed the formation of amorphous silicoaluminates of similar nature. The microstructure consisted of unreacted quartz and metakaolinite particles in a matrix of silicoaluminate polymer and condensed silica gel from the unreacted sodium silicate. 相似文献
98.
99.
100.
Igor V. Zagaynov Ivan V. Shelepin Anatoly A. Konovalov Ekaterina A. Obraztsova Alexander V. Naumkin Alexey V. Bykov Vladimir G. Leontiev 《Ceramics International》2021,47(6):8142-8149
Ceria based solid solutions doped by Gd, Bi, and the third dopant were synthesized by the co-precipitation method with ultrasonic treatment, followed by calcination at the temperature of 500°С. Characterization of the synthesized nanosystems by XRD, TEM, TG, Raman spectroscopy, FTIR, XPS was carried out. It is shown that all obtained powders of solid solutions crystallized into a cubic structure of the fluorite type, with an average particle size of 5–15 nm. The samples had a mesoporous structure of the pore diameter of 2–5 nm. The catalytic activity of Gd-Bi-M-Ce-O (M = Cu, Zr, Ni, Co, Mn) solid solutions was carried out. The catalyst Gd0.05Bi0.15Mn0.20Ce0.60O2 has the lowest oxidation temperature. 相似文献