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121.
Steven Euijong Whang Omar Benjelloun Hector Garcia-Molina 《The VLDB Journal The International Journal on Very Large Data Bases》2009,18(6):1261-1277
Entity resolution (ER) (also known as deduplication or merge-purge) is a process of identifying records that refer to the same real-world entity and merging them together. In practice, ER results may contain “inconsistencies,” either due to mistakes by the match and merge function writers or changes in the application semantics. To remove the inconsistencies, we introduce “negative rules” that disallow inconsistencies in the ER solution (ER-N). A consistent solution is then derived based on the guidance from a domain expert. The inconsistencies can be resolved in several ways, leading to accurate solutions. We formalize ER-N, treating the match, merge, and negative rules as black boxes, which permits expressive and extensible ER-N solutions. We identify important properties for the rules that, if satisfied, enable less costly ER-N. We develop and evaluate two algorithms that find an ER-N solution based on guidance from the domain expert: the GNR algorithm that does not assume the properties and the ENR algorithm that exploits the properties. 相似文献
122.
O. A. Omar H. F. Ragaie W. F. Fikry 《Journal of Materials Science: Materials in Electronics》1990,1(2):79-83
The aim of the present work was to prepare fairly uniform transparent and conductive tin oxide films using an inexpensive and easily controllable method. The technique adopted was spray deposition. The design of the spray deposition apparatus takes into consideration its reliability in controlling the different parameters affecting the formation of deposited layers, as well as its adaptability for large-area applications. The growth rate was independent of substrate type but increased with increasing substrate temperature. The crystalline structure of the films was found to be a function of substrate temperature and film thickness. The X-ray diffraction patterns showed that the preferred orientation was (110) and the grain size was in the range of a few tens of nanometres. The variation of sheet resistance with deposition parameters was studied and an empirical formula relating the sheet resistance to the film thickness was obtained. The prepared tin oxide layers of thicknesses up to 200 nm were found to have a transparency of about 80% to 85%, which makes them suitable for application as a single antireflecting coating of silicon solar cells. 相似文献
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124.
Grigori M. Sisoev Omar K. Matar Christopher J. Lawrence 《Chemical engineering science》2005,60(3):827-838
In this work, we present results of a study of gas absorption into a falling film on a vertical substrate. The film flow is accompanied by the formation of nonlinear waves which strongly influence the diffusion layer that develops from the film surface. As a result, significant enhancement of mass transfer has been observed in experiments. We use recent advances in modelling of the hydrodynamics and solve a two-dimensional convective-diffusion equation for the solute concentration. Numerical solutions for the finite-amplitude wave regimes and associated integral absorption rates are obtained for a range of flow conditions. Our results show clearly the influence of waves on the development of the diffusion layer and, in particular, the enhancement of absorption due to the waves; the existence of optimal conditions for maximizing the absorption rate is also demonstrated. 相似文献
125.
We present results for gas absorption into a liquid film flowing over a spinning disc. The flow is accompanied by the formation of nonlinear waves which strongly influence the diffusion boundary-layer that develops beneath the surface of the film. We use recent advances in modelling of the hydrodynamics and solve a two-dimensional convective-diffusion equation for the solute concentration. Numerical solutions for the finite-amplitude wave regimes and associated integral absorption rates are obtained for flow conditions corresponding to real experiments. Our results show clearly the enhancement of absorption due to the waves. 相似文献
126.
In this paper we present algorithms to implement PLA folding based on the interval graph theory. A PLA will be represented by five sets of nets: product-term nets (PT nets), input and output nets (I and O nets), and input and output connection nets (IC and OC nets). Column folding becomes a problem of permuting the rows such that the I/O nets can be placed in as few columns as possible. Algorithms for both unconstrained and constrained foldings are given. 相似文献
127.
In the present context, optimal portion control refers to the process of preparing can‐filling portions so that the deviation of the portion weight from a specified target weight is minimized. An approach has been developed for achieving this where a batch of objects is placed in a linearly overlapped optimal arrangement and then cut into portions using a series of parallel blades. The parameters of optimization are the arrangement order, orientation and degree of overlap of the objects. The approach has been demonstrated to produce impressive improvements in the application of fish canning. For this application, two approaches of optimal cutting are compared in the present paper. In one approach, the blade spacing is kept fixed and constant at a predetermined value. In the second approach, the blade spacing is varied for each portion after the objects are placed according to the optimal arrangement, where the target weight distribution is allowed to vary within a tolerance interval. The results presented in this paper indicate that the second approach produces a significantly higher percentage of acceptable portions than the first approach. What is presented are results from computer simulations, utilizing true data as measured from actual batches of fish. The paper demonstrates the potential benefit of the optimal portion control approach when applied in an industrial fish‐canning process. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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129.
Many packaging decisions are routine, but require a high level of expertise. The research described in this paper explores the use of expert systems for automating routine package development tasks. It begins with a general discussion of expert systems and outlines some feasible packaging applications in design, prediction, problem diagnosis, and management control. A PC-based prototype system is described, which is composed of six modules related to the following tasks: performance requirements, packaging solutions, testing specifications, testing results analysis, vendor specifications and procurement. 相似文献
130.
Alka Gupta Ambreen Nisar Shobit Omar Kantesh Balani 《JOM Journal of the Minerals, Metals and Materials Society》2018,70(10):1937-1945
The grain growth kinetics of 8YSZ ceramics processed using spark plasma sintering (SPS) has been investigated in the temperature ranging from 1100°C to 1500°C. The activation energy during SPS densification was obtained as 332 kJ/mol with grain boundary diffusion as a dominant mechanism. Further, the effect of CeO2 on the densification kinetics of 8YSZ ceramic processed via SPS and conventional sintering (CS) has been delineated. The lower grain boundary mobility of CS-processed composites (an order of magnitude lower than SPS) is attributed to the solute drag and lattice distortion mechanism. However, no significant change in the grain boundary mobility was observed with CeO2 addition (~?14.7–43.9?×?10?18 m3/N/s for CS and 107.2–116.7?×?10?18 m3/N/s for SPS) revealing that the defect concentration is nearly constant in 8YSZ. The study highlights the effect of sintering techniques (SPS and CS) and reinforcement (CeO2) on engineering the desired microstructure of 8YSZ ceramic. 相似文献