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Kinds of Filter Terms modified by Filter Selected AbstractsUSE OF CLARIFYING AGENTS AND ULTRA FILTER TO DECREASE FUMARIC ACID, HMF AND INCREASE CLARITY OF APPLE JUICEJOURNAL OF FOOD QUALITY, Issue 3 2006YAHYA TULEK ABSTRACT In this study, the effects of eight different processing treatments of apple juice (AJ) production (Process 1: Ultra filtration [UF], Process 2: Activated charcoal [AC], Process 3: polyvinylpolypyrolidone [PVPP], Process 4: Gelatine [G] + Bentonite [B], Process 5: [G + B] + UF, Process 6: [G + B] + AC, Process 7: [G + B] + PVPP and Process 8: [G + B] + Kieselguhr [K]) on the fumaric acid (FA), hydroxymethylfurfural (HMF), color and clearness values of AJ were investigated. With the exception of Processes 1 and 5, AC, K, PVPP, G and B were used at various doses in other processes. FA, HMF, color and clearness values of control sample were determined as 3.24 mg/L, 3.84 mg/L, 48.5 (%T) and 94.1 (%T), respectively. The highest proportional decrement in FA and HMF values of the samples were observed with Process 6 at the level of 5. The fifth level of Process 6 resulted in 35.8% (3.24,2.08 mg/L) and 35.9% (3.84 to 2.46 mg/L) reductions in FA and HMF values, respectively. On the other hand, the best improvement in clearness of AJ was obtained with Process 6 at the fourth level and obtained as 98.9 (%T). [source] DISTURBANCE REJECTION USING AN ILC ALGORITHM WITH ITERATION VARYING FILTERSASIAN JOURNAL OF CONTROL, Issue 3 2004M. Norrlöf ABSTRACT An Iterative Learning Control disturbance rejection approach is considered and it is shown that iteration variant learning filters can asymptotically give the controlled variable zero error and zero variance. Convergence is achieved with the assumption that the relative model error is less than one. The transient response of the suggested ILC algorithm is also discussed using a simulation example. [source] EFFICIENT MARKOV NETWORK DISCOVERY USING PARTICLE FILTERSCOMPUTATIONAL INTELLIGENCE, Issue 4 2009Dimitris Margaritis In this paper, we introduce an efficient independence-based algorithm for the induction of the Markov network (MN) structure of a domain from the outcomes of independence test conducted on data. Our algorithm utilizes a particle filter (sequential Monte Carlo) method to maintain a population of MN structures that represent the posterior probability distribution over structures, given the outcomes of the tests performed. This enables us to select, at each step, the maximally informative test to conduct next from a pool of candidates according to information gain, which minimizes the cost of the statistical tests conducted on data. This makes our approach useful in domains where independence tests are expensive, such as cases of very large data sets and/or distributed data. In addition, our method maintains multiple candidate structures weighed by posterior probability, which allows flexibility in the presence of potential errors in the test outcomes. [source] Interactive shadowing for 2D AnimeCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2-3 2009Eiji Sugisaki Abstract In this paper, we propose an instant shadow generation technique for 2D animation, especially Japanese Anime. In traditional 2D Anime production, the entire animation including shadows is drawn by hand so that it takes long time to complete. Shadows play an important role in the creation of symbolic visual effects. However shadows are not always drawn due to time constraints and lack of animators especially when the production schedule is tight. To solve this problem, we develop an easy shadowing approach that enables animators to easily create a layer of shadow and its animation based on the character's shapes. Our approach is both instant and intuitive. The only inputs required are character or object shapes in input animation sequence with alpha value generally used in the Anime production pipeline. First, shadows are automatically rendered on a virtual plane by using a Shadow Map1 based on these inputs. Then the rendered shadows can be edited by simple operations and simplified by the Gaussian Filter. Several special effects such as blurring can be applied to the rendered shadow at the same time. Compared to existing approaches, ours is more efficient and effective to handle automatic shadowing in real-time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Fragment-Parallel Composite and FilterCOMPUTER GRAPHICS FORUM, Issue 4 2010Anjul Patney We present a strategy for parallelizing the composite and filter operations suitable for an order-independent rendering pipeline implemented on a modern graphics processor. Conventionally, this task is parallelized across pixels/subpixels, but serialized along individual depth layers. However, our technique extends the domain of parallelization to individual fragments (samples), avoiding a serial dependence on the number of depth layers, which can be a constraint for scenes with high depth complexity. As a result, our technique scales with the number of fragments and can sustain a consistent and predictable throughput in scenes with both low and high depth complexity, including those with a high variability of depth complexity within a single frame. We demonstrate composite/filter performance in excess of 50M fragments/sec for scenes with more than 1500 semi-transparent layers. [source] Speed Estimation from Single Loop Data Using an Unscented Particle FilterCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 7 2010Zhirui Ye The Kalman filters used in past speed estimation studies employ a Gaussian assumption that is hardly satisfied. The hybrid method that combines a parametric filter (Unscented Kalman Filter) and a nonparametric filter (Particle Filter) is thus proposed to overcome the limitations of the existing methods. To illustrate the advantage of the proposed approach, two data sets collected from field detectors along with a simulated data set are utilized for performance evaluation and comparison with the Extended Kalman Filter and the Unscented Kalman Filter. It is found that the proposed method outperforms the evaluated Kalman filter methods. The UPF method produces accurate speed estimation even for congested flow conditions in which many other methods have significant accuracy problems. [source] Short-Term Traffic Volume Forecasting Using Kalman Filter with Discrete Wavelet DecompositionCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2007Yuanchang Xie Short-term traffic volume data are often corrupted by local noises, which may significantly affect the prediction accuracy of short-term traffic volumes. Discrete wavelet decomposition analysis is used to divide the original data into several approximate and detailed data such that the Kalman filter model can then be applied to the denoised data and the prediction accuracy can be improved. Two types of wavelet Kalman filter models based on Daubechies 4 and Haar mother wavelets are investigated. Traffic volume data collected from four different locations are used for comparison in this study. The test results show that both proposed wavelet Kalman filter models outperform the direct Kalman filter model in terms of mean absolute percentage error and root mean square error. [source] Tunable Guided-Mode Resonance Grating FilterADVANCED FUNCTIONAL MATERIALS, Issue 13 2010Adriana Szeghalmi Abstract The optical characteristics of shallow 2D nanostructured polycarbonate samples are presented. Tunable guided-mode resonance filters are experimentally demonstrated for the visible spectral range when functional coatings are applied to 2D nanostructures by means of atomic layer deposition. The wavelength position of the reflection peaks can be easily tuned in a broad range (>150,nm) through rotation of the optical element around the axis normal to the substrate without changing the rest of the optical setup. Rigorous coupled wave approach simulation of model systems is performed to obtain insight into the complexity of the optical properties of these systems. The photonic nanostructures presented here are promising optics for application in ultra-compact, portable, miniaturized optical systems. [source] Isocyanates, aminoisocyanates and amines from fires,a screening of common materials found in buildingsFIRE AND MATERIALS, Issue 6 2003Per Blomqvist Abstract Isocyanates, aminoisocyanates and amines were quantified from the combustion of 24 different materials or products typically found in buildings. Small-scale combustion experiments were conducted in the cone calorimeter, where generally well-ventilated combustion conditions are attained. Measurements were further made in two different full-scale experiments. Isocyanates and amino-compounds were sampled using an impinger-filter sampling system with a reagent solution of di-n-butylamine in toluene. Filter and impinger solution were analysed separately using LC-MS technique. Further the particulate distribution in the smoke gases was determined by impactor technique, and selected gaseous compounds quantified by FTIR. It was found in the small-scale that isocyanates were produced from the majority of the materials tested. The highest concentration was found for glass wool insulation, and further high concentrations were found for PUR products, particleboard, nitrile rubber and melamine. Lower concentrations were found for wood and cable-products. Amino-isocyanates and amines were generally found from PUR products only. The distribution of isocyanates between the particulate- and fluid phases varied for the different materials and a tendency to enrichment of particles was seen for some of the materials. Further, when comparing the potential health hazard between isocyanates and other major fire gases (based on NIOSH IDLH-values) it was found that isocyanates in several cases represented the greatest hazard. Copyright © 2003 John Wiley & Sons, Ltd. [source] Filter-based fault detection and diagnosis using output PDFs for stochastic systems with time delaysINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 4 2006Y. M. Zhang Abstract In this paper, a fault detection and diagnosis (FDD) scheme is studied for general stochastic dynamic systems subjected to state time delays. Different from the formulation of classical FDD problems, it is supposed that the measured information for the FDD is the probability density function (PDF) of the system output rather than its actual value. A B-spline expansion technique is applied so that the output PDF can be formulated in terms of the dynamic weights of the B-spline expansion, by which a time delay model can be established between the input and the weights with non-linearities and modelling errors. As a result, the concerned FDD problem can be transformed into a classic FDD problem subject to an uncertain non-linear system with time delays. Feasible criteria to detect the system fault are obtained and a fault diagnosis method is further presented to estimate the fault. Simple simulations are given to demonstrate the efficiency of the proposed approach. Copyright © 2006 John Wiley & Sons, Ltd. [source] New Design of a Ceramic Filter for Diesel Emission Control ApplicationsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2005Aleksander J. Pyzik Diesel particulate filters (DPF) made from an advanced ceramic material (ACM) based on mullite have demonstrated high filtration efficiency, low-pressure drop, high-temperature handling capability, and excellent mechanical integrity at a porosity of 60% or higher. Due to the ability to control microstructure, total porosity, and particle size distribution, Dow's acicular mullite can be tailored to meet requirements for deep bed filtration and fine particles emission control. In addition, the ACM DPF is suitable for catalyzed applications and it can retain its performance with a broad range of catalysts and over a wide range of catalyst loadings. This study describes a material selected for a DPF design that meets current diesel particulate emission control requirements as well as a four-way NOx control system. [source] Political and Regulatory Risk in Water Utilities: Beta Sensitivity in the United KingdomJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 7-8 2001Roger Buckland UK utilities are generally regulated by the periodic setting of a price cap (the RPI-X mechanism). To establish these caps, regulators must determine what returns are appropriate on the capital employed by utilities. This paper addresses the issue of the level of risk inherent in investment in the equity of regulated water utilities in the UK. It uses the techniques of the Kalman Filter to estimate daily betas for the major utilities in the period from privatisation to mid-1999. The paper demonstrates that water utilities' risk is time-variant. It demonstrates, also, that there have been significant political and regulatory influences in the systematic risk faced by water utility shareholders. It finds beta to display little evidence of cyclical variation across the regulatory review cycle. The paper also confirms that significant excess returns have been generated over the history of the privatised water sector and suggests that over-estimation of systematic risk faced by investors in the sector may imply further excess returns in the next regulatory review period. [source] 2D map-building and localization in outdoor environmentsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1 2005R. Madhavan Determining the pose (position and orientation) of a vehicle at any time is termed localization and is of paramount importance in achieving reliable and robust autonomous navigation. Knowing the pose it is possible to achieve high level tasks such as path planning. A new map-based algorithm for the localization of vehicles operating in harsh outdoor environments is presented in this article. A map building algorithm using observations from a scanning laser rangefinder is developed for building a polyline map that adequately captures the geometry of the environment. Using this map, the Iterative Closest Point (ICP) algorithm is employed for matching laser range images from the rangefinder to the polyline map. Once correspondences are established, an Extended Kalman Filter (EKF) algorithm provides reliable vehicle state estimates using a nonlinear observation model based on the vertices of the polyline map. Data gathered during field trials in an outdoor environment is used to test the efficiency of the proposed ICP-EKF algorithm in achieving the localization of a four-wheel drive (4WD) vehicle. © 2005 Wiley Periodicals, Inc. [source] Robust Navigation and Mapping Architecture for Large EnvironmentsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2003Favio Masson This paper addresses the problem of Simultaneous Localization and Mapping (SLAM) for very large environments. A hybrid architecture is presented that makes use of the Extended Kalman Filter to perform SLAM in a very efficient form and a Monte Carlo localizer to resolve data association problems potentially present when returning to a known location after a large exploration period. Algorithms to improve the convergence of the Monte Carlo filter are presented that consider vehicle and sensor uncertainty. The proposed algorithm incorporates significant integrity to the standard SLAM algorithms by providing the ability to handle multimodal distributions over robot pose in real time during the re-localization process. Experimental results in outdoor environments are presented to demonstrate the performance of the algorithm proposed. © 2003 Wiley Periodicals, Inc. [source] A Customizable Instrument for Measuring the Mechanical Properties of Thin Biomedical MembranesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005Gracián Triviño Abstract Summary: A customized instrument has been developed as part of multidisciplinary research work relating to the development of a biodegradable vascular scaffold. This instrument aims to measure the mechanical properties of elastic and viscoelastic thin membranes with tissue engineering applications. Uniform and omni-directional pressure is applied on the whole membrane which is uniformly clamped and submerged into a liquid medium. The mechanical testing described in this study is focused on the stress-strain curves of polycaprolactone (PCL) films after different treatments. The influence of Dulbecco's modified Eagle's culture medium, L929 fibroblast culture, NaOH treatment and film thickness on the mechanical properties of PCL films was evaluated after different times. These studies show that the PCL degradation process is influenced by immersion in the culture medium, inducing an increment in the slope of the pressure-dilation curve which is indicative of an increase in the polymer stiffness. On the other hand, long NaOH treatments make PCL films have more flexible behavior. A computerized version of the instrument: (1) Electrical compressor; (2) Filter; (3) Voltage-pressure converter; (5) Pressure sensor; (6) Differential pressure sensor; (7,8) Main and auxiliary pipettes; (9) Printed circuit board; (10) Personal computer. [source] Design of compact, wide-band bandstop filters with sharp-rejection characteristicsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008Mrinal Kanti Mandal Abstract In this study, a novel transmission line configuration has been proposed to design a sharp-rejecting, compact bandstop filter with wide rejection-bandwidth. Signal interference technique is used to obtain transmission zeros, which provide the sharp rejection characteristic. Rejection bandwidth is controlled by the characteristic impedances of transmission lines. Filter is analyzed using transmission line model. Theoretical predictions have been verified by the measurements of two compact filters fabricated in microstrip line. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1244,1248, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23335 [source] Effect of light filters on reading speed in normal and low vision due to age-related macular degenerationOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2004Frank Eperjesi Abstract Purpose:, To investigate the effects of light filters on reading speed in normal and low vision due to age-related macular degeneration (AMD). Methods:, Reading speed was determined for 12 subjects with normal vision and 12 subjects with non-exudative AMD using stationary lowercase nonsensical print in Times Roman font and four light filters; a yellow Corning Photochromic Filter (CPF) 450, a grey neural density (ND) filter, an individual filter obtained using the Intuitive Colorimeter® and a clear filter. Results:, There was no statistically significant light filter effect on reading speed for the normal subjects. The AMD group demonstrated a statistically significant 5% average improvement in reading speed with the CPF450 compared with the other filters although some AMD subjects had improvements of 10,15%. Conclusions:, Light filters obtained using the Intuitive Colorimeter® performed poorly when compared with the CPF450, ND and clear filters for both the study groups. For the AMD group, average reading speed was statistically greater with the CPF450 than the other filters, however it is questionable whether the improvement (5%) would be clinically significant. As some of the subjects with AMD had greater improvements with the CPF450 we advocate clinical assessment of light filters using existing protocols on an individual basis. [source] Assimilation of satellite-derived soil moisture from ASCAT in a limited-area NWP modelTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 648 2010Jean-François Mahfouf Abstract A simplified Extended Kalman Filter is developed for the assimilation of satellite-derived surface soil moisture from the Advanced Scatterometer (ASCAT) instrument (on board the polar-orbiting satellite METOP) in a limited-area NWP model where soil water vertical transfers are described by a force,restore method. An analytic formulation of the land surface scheme Jacobians is derived to simplify the coupling between land surface and atmospheric data assimilation systems. Various steps necessary before the assimilation of ASCAT products are defined: projection of satellite data on the model grid, screening based on various criteria, bias correction using a CDF matching technique, and specification of model and observation errors. Three-dimensional variational data assimilation experiments are then performed during a four-week period in May 2009 over western Europe. A control assimilation is also run where the soil moisture evolves freely. Forecasts from these analyses show that the assimilation of ASCAT data slightly reduces the daytime low-level relative humidity positive bias of the control run. Forecast skill scores with respect to other variables are rather neutral. A comparison of the control run with the operational system where soil moisture is corrected from short-range forecast errors of screen-level observations show similar improvements but are more pronounced. These differences come from the fact that the number of screen-level observations from the surface network over Europe is significantly larger than those provided by a polar-orbiting satellite. These results are consistent with those obtained at ECMWF using soil moisture products derived from other satellite instruments (X-band radiometer TMI and C-band scatterometer ERS). Several avenues for improving this preliminary methodology are proposed. Copyright © 2010 Royal Meteorological Society [source] Issues in targeted observingTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 613 2005(Invited paper for the Q. J. R. Meteorol. Abstract This paper summarizes successes and limitations of targeted observing field programmes starting from the Fronts and Atlantic Storm-Track Experiment in 1997 through recent programmes targeting winter storms and tropical cyclones. These field programmes have produced average reductions in short-range forecast errors of about 10 per cent over regional verification areas, and maximum forecast error reductions as large as 50 per cent in certain cases. The majority of targeting cases investigated so far involve sets of dropsondes and other observation data that provide partial coverage of target areas. The primary scientific challenges for targeting include the refinement of objective methods that can identify optimal times and locations for targeted observations, as well as identify the specific types of satellite and in situ measurements that are required for the improvement of numerical weather forecasts. The most advanced targeting procedures, at present, include: the ensemble transform Kalman Filter, Hessian singular vectors, and observation-space targeting using the adjoint of a variational data assimilation procedure. Targeted observing remains an active research topic in numerical weather prediction, with plans for continued refinement of objective targeting procedures, and field tests of new satellite and in situ observing systems. Copyright © 2005 Royal Meteorological Society [source] Tropical Pacific Ocean model error covariances from Monte Carlo simulationsTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 613 2005O. Alves Abstract As a first step towards the development of an Ensemble Kalman Filter (EnKF) for ocean data assimilation in the tropical oceans, this article investigates a novel technique for explicitly perturbing the model error in Monte Carlo simulations. The perturbation technique involves perturbing the surface zonal stress. Estimates of the characteristics of the wind stress errors were obtained from the difference between zonal wind fields from the NCEP and ECMWF re-analyses. In order to create random zonal wind stress perturbations, an EOF analysis was performed on the intraseasonally time-filtered difference between the two re-analysis products. The first 50 EOFs were retained and random wind stress fields for each ensemble member were created by combining random amounts of each EOF. Ensemble runs were performed using a shallow-water model, with both short forecasts and long simulations. Results show covariance patterns characteristic of Kelvin wave and Rossby wave dynamics. There are interesting differences between covariances using short forecasts and those using long simulations. The use of the long simulations produced non-local covariances (e.g. negative covariances between east and west Pacific), whereas short forecasts produced covariances that were localized by the time it takes Kevin and Rossby waves to travel over the forecast period and the scales of spatial covariance in the wind stress errors. The ensembles of short forecasts produced covariances and cross-covariances that can be explained by the dynamics of equatorial Rossby and Kevin waves forced by wind stress errors. The results suggest that the ensemble generation technique to explicitly represent the model error term can be used in an EnKF. Copyright © 2005 Royal Meteorological Society [source] Wavelets in state space modelsAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 3 2003Eliana Zandonade Abstract In this paper, we consider the utilization of wavelets in conjunction with state space models. Specifically, the parameters in the system matrix are expanded in wavelet series and estimated via the Kalman Filter and the EM algorithm. In particular this approach is used for switching models. Two applications are given, one to the problem of detecting the paths of targets using an array of sensors, and the other to a series of daily spreads between two Brazilian bonds. Copyright © 2003 John Wiley & Sons, Ltd. [source] Online identification of nonlinear multivariable processes using self-generating RBF neural networksASIAN JOURNAL OF CONTROL, Issue 5 2010Karim Salahshoor Abstract This paper addresses the problem of online model identification for multivariable processes with nonlinear and time-varying dynamic characteristics. For this purpose, two online multivariable identification approaches with self-organizing neural network model structures will be presented. The two adaptive radial basis function (RBF) neural networks are called as the growing and pruning radial basis function (GAP-RBF) and minimal resource allocation network (MRAN). The resulting identification algorithms start without a predefined model structure and the dynamic model is generated autonomously using the sequential input-output data pairs in real-time applications. The extended Kalman filter (EKF) learning algorithm has been extended for both of the adaptive RBF-based neural network approaches to estimate the free parameters of the identified multivariable model. The unscented Kalman filter (UKF) has been proposed as an alternative learning algorithm to enhance the accuracy and robustness of nonlinear multivariable processes in both the GAP-RBF and MRAN based approaches. In addition, this paper intends to study comparatively the general applicability of the particle filter (PF)-based approaches for the case of non-Gaussian noisy environments. For this purpose, the Unscented Particle Filter (UPF) is employed to be used as alternative to the EKF and UKF for online parameter estimation of self-generating RBF neural networks. The performance of the proposed online identification approaches is evaluated on a highly nonlinear time-varying multivariable non-isothermal continuous stirred tank reactor (CSTR) benchmark problem. Simulation results demonstrate the good performances of all identification approaches, especially the GAP-RBF approach incorporated with the UKF and UPF learning algorithms. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] On the observation of traveling acoustic waves in the solar atmosphere using a magneto-optical filterASTRONOMISCHE NACHRICHTEN, Issue 3-4 2007M. Haberreiter Abstract In contrast to low-frequency waves that are trapped in the cavity of the Sun, high-frequency waves can travel freely in the solar atmosphere. By modelling the observed intensity signal in the red and blue wings of K I 7699 Å and Na I 5890 Å, we aim to better understand the measurements carried out with the Magneto-Optical Filter at Two Heights (MOTH) experiment. We model the observed intensity signal with radiative transfer calculations carried out with the COde for Solar Irradiance (COSI). Furthermore, we derive the formation height of the lines in order to analyze to what extent the contribution functions are modulated by the acoustic waves. We find a phase lag between the red and blue filter for acoustic waves with a frequency above ,7 mHz and conclude that a frequency dependent data analysis is required for higher frequencies. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Soil model parameter estimation with ensemble data assimilationATMOSPHERIC SCIENCE LETTERS, Issue 2 2009Biljana Orescanin Abstract A parameter estimation problem in context of ensemble data assimilation is addressed. In an example using a one-point soil temperature model, the parameters corresponding to the emissivity and to the effective depth between the surface and the lowest atmospheric model level are estimated together with the initial conditions for temperature. The nonlinear synthetic observations representing various fluxes are assimilated using the Maximum Likelihood Ensemble Filter (MLEF). The results indicate a benefit of simultaneous assimilation of initial conditions and parameters. The estimated uncertainties are in general agreement with actual uncertainties. Copyright © 2009 Royal Meteorological Society [source] Modelling the Equity Beta Risk of Australian Financial Sector CompaniesAUSTRALIAN ECONOMIC PAPERS, Issue 3 2000Frida Lie In this paper we apply the generalised auto-regressive conditional heteroskedasticity (GARCH) and Kalman Filter approaches to modelling the equity beta risk of a sample of fifteen Australian financial sector companies. A de-regulated environment in which strong competitive forces are at play typifies the period of investigation. Consistent with the existing literature, we find that these modelling techniques perform well and, in particular, that the Kalman Filter approach is preferred. Further, we find that considerable variability of risk occurs throughout the sample period. Thus, extending the evidence of Harper and Scheit (1992); Brooks and Faff (1995) and Brooks, Faff and McKenzie (1997), we find evidence consistent with the hypothesis that deregulation has impacted the risk of banking sector stocks. [source] Titelbild: Bautechnik 9/2007BAUTECHNIK, Issue 9 2007Article first published online: 4 SEP 200 Beim Bau von Dämmen und Deichen, bei Böschungs- und Sohlensicherungen an Wasserstraßen sowie im Hafenbau und Küstenschutz kommen häufig Terrafix® Geotextilien der NAUE GmbH & Co. KG für filtertechnische Aufgaben zum Einsatz. Das Bild zeigt die Großrollenverlegung von Terrafix® Filtervliesstoffen auf einer Tondichtung in der Baumaßnahme Dortmund-Ems-Kanal, Baulos Greven. Die technischen Anforderungen an das Geotextil werden in der TLG 2003 (Technische Lieferbedingungen für geotextile Filter) ausführlich beschrieben. (Foto: NAUE) [source] An Integrated Process for Mammalian Cell Perfusion Cultivation and Product Purification Using a Dynamic FilterBIOTECHNOLOGY PROGRESS, Issue 4 2002Leda R. Castilho In the present work, a dynamic filter was employed to develop an integrated perfusion/purification process. A recombinant CHO cell line producing a human anti-HIV IgG was employed in the experiments. In the first part of this work, the dynamic filter was fitted with conventional microfiltration membranes and tested as a new external cell retention device for perfusion cultivations. The filter was connected to a running perfusion bioreactor and operated for approximately 400 h at an average cell concentration of 10 million cells mL,1, whereby cell viability remained above 90% and no problems of sterility were experienced. In the second part of this work, the dynamic filter was employed to simultaneously carry out cell separation and product purification, using membrane adsorbers containing Protein A affinity ligands. An automated system was built, which integrated the features of an automated perfusion bioreactor and of a liquid chromatography system. The IgG was continuously adsorbed onto the affinity membranes and was periodically recovered through elution cycles. After connection of the filter, the system was operated for approximately 300 h, whereby three elution cycles were carried out. No progressive increase in transmembrane pressure was observed, indicating no membrane fouling problems, and the IgG was recovered practically free of contaminants in a 14-fold concentrated form, indicating that the integrated, one-step perfusion/purification process developed during this work is a promising alternative for the production of biologicals derived from mammalian cells. [source] Kontinuierliche Filter in der Fest/Flüssig-TrennungCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 11 2007R. Bott Dr.-Ing. Abstract Kontinuierliche Drehfilter sind Basisbausteine der Filtrationstechnik und erfüllen bei vielen Produktionsprozessen wichtige trenntechnische Aufgaben. Bei Fragen zur richtigen Apparateauswahl bis hin zum optimalen Betrieb dieser Trenntechnologien suchen Betriebsingenieure aber häufig vergebens nach verlässlichen Informationen oder kompetenten Antworten, wie sie das vorgestellte praxisgerechte Fortbildungsangebot bietet. [source] [Ru(0)]@SiO2 and [RuO2]@SiO2 Hybrid Nanomaterials: From Their Synthesis to Their Application as Catalytic Filters for Gas SensorsADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Victor Matsura Abstract [Ru(0)]@SiO2 and [RuO2]@SiO2 hybrid nanomaterials are produced following a facile method consisting of the synthesis of size-controlled ruthenium nanoparticles as elemental bricks. This route takes advantage of the organometallic approach and the use of a bifunctional ligand for the synthesis of ruthenium nanoparticles from [Ru(COD)(COT)](COD,=,1,3-cyclooctadiene, COT,=,1,3,5-cyclooctatriene) as metal precursor and (PhCH2)2N(CH2)11O(CH2)3Si(OEt)3 (benzenemethanamine) as stabilizer. Hydrolysis and polycondensation steps via a sol,gel approach lead to the formation of the silica materials containing the metal nanoparticles. A final calcination step in air at 400,°C yields the [RuO2]@SiO2 nanocomposites. Such hybrid nanomaterials display a good dispersion of the nanoparticles inside the silica matrix and interesting porosity properties making them attractive materials for catalytic applications. This is shown by using [RuO2]@SiO2 hybrid nanomaterials as catalytic filters for gas sensors. [source] Implantation of Bilateral Carotid Artery Filters to Allow Safe Removal of Left Atrial Thrombus During Ablation of Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2006SILVIA MARTELO M.D. Left atrial clot formation is a feared complication of catheter ablation for atrial fibrillation. We report a case of left atrial thrombus that formed around the circular mapping catheter before the delivery of RF. Successful retrieval of the clot was obtained by withdrawing the catheters while protecting the anterior cerebral circulation by positioning temporary carotid artery filters. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||