Generalized Stauffer�CGrimson background subtraction for dynamic scenes

We propose an adaptive model for backgrounds containing significant stochastic motion (e.g. water). The new model is based on a generalization of the Stauffer–Grimson background model, where each mixture component is modeled as a dynamic texture. We derive an online K-means algorithm for updating the parameters using a set of sufficient statistics of the model. Finally, we report on experimental results, which show that the proposed background model both quantitatively and qualitatively outperforms state-of-the-art methods in scenes containing significant background motions.     

Studies on capillary waves generated by light pulses of Nd3+ - glass laser with ultrasonic Q-switch

In the paper some results of the studies on parameters of capillary waves generated in 18H2N4WA type steel by means of light pulses of Nd³⁺ - glass laser with ultrasonic modulation of Q-factor of the optical resonator have been presented.     

A flexible three-level logistic network design considering cost and time criteria with a multi-objective evolutionary algorithm

Nowadays, time and cost are familiar criteria for every logistic provider, and both have been long treated to be minimized simultaneously. However, the criteria are naturally conflicted even with flexibilities and/or constraints appeared in the logistic networks. This paper is concerned with three-level logistic networks with potential suppliers, distributed centers (DCs), and deterministic demands from available consumers. The networks also benefit from potential direct shipments from suppliers to consumers as long as suppliers and DCs facilities might face limited capacity in their own seasonal supplying and warehousing processes. The goal is (re)configure the networks in order to minimize response time to consumers, transportation cost and facility cost. Therefore, the networks are formulated as multiple criteria decision making problems, which have more than one configuration through the time and cost optimizing at the same time. Due to the flexibility and the constraints, the decision maker(s) needs a set of compromise solutions for the networks that represent optimal configurations based on the objectives without considering prior knowledge. To this end, the problems are formulated into four individual logistic network models varying with the flexibility option and/or the capacitated facilities. To find the compromise solutions, Pareto-based multi-objective evolutionary algorithm, NSGA-II is customized and then utilized to deal with an illustrative case study. The results are analyzed through the two performance measures, hypervolume and the number of optimal solutions obtained so far.     

A toolkit for constructing command driven graphics programs

This paper describes a toolkit designed to construct graphics applications on top of it that are command driven. The aim in its design is to achieve a uniform look-and-feel for the applications developed in the department, and to make it possible to construct demonstration programs or test programs of ongoing research that required a sophisticated user interface with minimal fuss. The present implementation runs under UNIX, but the same philosophy could be used in other environments.     

Combining preventive replacement and burn‐in procedures

This paper considers a non‐homogeneous population of items. Most of the items fail due to a wear‐out process. Therefore it is reasonable to employ a procedure of preventive maintenance. Some items, however, are of short life due to intrinsic defects. When used as replacement parts they may spoil results of planned prevention. The paper seeks for equilibrium of burn‐in and preventive replacement periods. Copyright © 2002 John Wiley & Sons, Ltd.     

An object-oriented operation-based approach to translation between MOF metaschemas

This paper proposes a new approach to the schema translation problem. We deal with schemas whose metaschemas are instances of the OMG’s MOF. Most metaschemas can be defined as an instance of the MOF; therefore, our approach is widely applicable. We leverage the well-known object-oriented concepts embedded in the MOF and its instances (object types, attributes, relationship types, operations, IsA hierarchies, refinements, invariants, pre- and postconditions, etc.) to define metaschemas, schemas and their translations.The main contribution of our approach is the extensive use of object-oriented concepts in the definition of translation mappings, particularly the use of operations (and their refinements) and invariants, both of which are formalized in OCL. Our translation mappings can be used to check that two schemas are translations of each other, and to translate one into the other, in both directions. The translation mappings are declaratively defined by means of pre- and postconditions and invariants, and they can be implemented in any suitable language. From an implementation point of view, by taking a MOF-based approach we have a wide set of tools available, including tools that execute OCL. By way of example, we have defined all schemas and metaschemas in this paper and executed all the OCL expressions in the USE tool.     

Bonding of Dental Glass to Nickel-Chromium Alloys

Two 80Ni · 20Cr-type alloys, one 99.99% pure and one with 98% purity, formed a multilayer oxide scale with an outer layer of NiO and a single-layer scale with outer portion richer in Cr₂O₃, respectively. An applied K-aluminosilicate glass at 1020°C penetrated the latter oxide scale. Adherence was present at all interfaces due to the existence of chemical equilibrium. Fracture occurred in the multilayer oxide scale and in the glass close to the oxide glass interface, respectively.     

Performance of an industrial biofilter from a composting plant in the removal of ammonia and VOCs after material replacement

BACKGROUND: Biofiltration is a suitable odor reduction technique for the treatment of gaseous emissions from composting processes, but little is known about the start‐up of full‐scale biofilters after material replacement and their performance after several years of operation. RESULTS: Biofilter material (wood chips used previously as bulking agent in a composting process) can effectively remove ammonia and most of the volatile organic compounds (VOCs) content, achieving removal efficiencies greater than 70% for VOCs and near 90% for ammonia immediately after material replacement. These removal efficiencies were maintained for several months after material replacement. In the studied full‐scale biofilter no lag phase was observed in the removal of ammonia whereas in the case of VOCs different patterns were detected during biofilter start‐up. For the old biofilter material, after 4 years of operation, a statistically significant decrease of removal efficiency for ammonia in comparison with the new material was detected. No statistically significant differences were found in the case of VOCs. CONCLUSIONS: Data on the emissions of several pollutants from biofilters treating composting exhaust gases have been systematically obtained. The tested filtering media presented adequate properties for biofiltration of gases emitted during the composting process. Copyright © 2009 Society of Chemical Industry     

A new perovskite PbIno, sTao. sO3 (PIT)

PbIno. 5Tao. 5O3 (PIT) single crystals have been grown using the flux method. Both pyrochlore and perovskite crystals have been obtained. The perovskite PIT crystals were partially ordered. The ε(T) dependence shows two anomalies at 150°C and 205°C. The low temperature phase in this ordered PIT is antiferroelectric with monoclinic distortion of the pseudo-perovskite unit cell.     

Modeling of a bacterial and fungal biofilter applied to toluene abatement: Kinetic parameters estimation and model validation

Biofiltration has been established as a promising alternative to conventional air pollution control technologies. However, gas biofilters modeling has been less developed than experimental research due to the complexity of describing the fundamental processes and the lack of globally accepted physical, chemical and biological parameters. In addition, biofiltration modeling based on degradation activity of fungi has been rarely considered. For this reason, in this work, a dynamic model describing toluene abatement by a bacterial and fungal biofilter is developed, calibrated and validated. The mathematical model is based on detailed mass balances which include the main processes involved in the system: convection, absorption, diffusion and biodegradation. The model was calibrated and validated using experimental data obtained from two equal lab-scale biofilters packed with coconut fiber and pine leaves, respectively. Both reactors were operated under similar conditions during 100 days at an empty bed residence time of 60 s and an average inlet load of 77 g toluene m⁻³ h⁻¹. Biofilters were initially inoculated with a bacterial consortium, even though reactors were mostly colonized by fungi after 60 days of operation according to microscopic observation and reactors pH. Removal efficiency increased notably from 20% for the bacterial period to 80% for the fully developed fungal biofilters. Since kinetic parameters are strongly dependent on the biological population, semi-saturation constants for toluene and maximum growth rates were determined for bacterial and fungal operation periods. Kinetic parameters were fitted by means of an optimization routine using either outlet concentrations or removal efficiency data from the coconut fiber biofilter. A novel procedure in gas biofilters modeling was considered for checking the model calibration, by the assessment of the parameters confidence interval based on the Fisher Information Matrix (FIM). Kinetic parameters estimated in the coconut fiber reactor were validated in the pine leaves biofilter for bacterial and fungal operation. Adequate model fitting to the experimental outlet gas concentration for both bacterial and fungal operation periods was verified by using a standard statistical test.