Advanced electronics for the CTF MEG system.

Science.gov (United States)

McCubbin, J; Vrba, J; Spear, P; McKenzie, D; Willis, R; Loewen, R; Robinson, S E; Fife, A A

2004-11-30

Development of the CTF MEG system has been advanced with the introduction of a computer processing cluster between the data acquisition electronics and the host computer. The advent of fast processors, memory, and network interfaces has made this innovation feasible for large data streams at high sampling rates. We have implemented tasks including anti-alias filter, sample rate decimation, higher gradient balancing, crosstalk correction, and optional filters with a cluster consisting of 4 dual Intel Xeon processors operating on up to 275 channel MEG systems at 12 kHz sample rate. The architecture is expandable with additional processors to implement advanced processing tasks which may include e.g., continuous head localization/motion correction, optional display filters, coherence calculations, or real time synthetic channels (via beamformer). We also describe an electronics configuration upgrade to provide operator console access to the peripheral interface features such as analog signal and trigger I/O. This allows remote location of the acoustically noisy electronics cabinet and fitting of the cabinet with doors for improved EMI shielding. Finally, we present the latest performance results available for the CTF 275 channel MEG system including an unshielded SEF (median nerve electrical stimulation) measurement enhanced by application of an adaptive beamformer technique (SAM) which allows recognition of the nominal 20-ms response in the unaveraged signal.

Modeling the system dynamics for nutrient removal in an innovative septic tank media filter.

Science.gov (United States)

Xuan, Zhemin; Chang, Ni-Bin; Wanielista, Martin

2012-05-01

A next generation septic tank media filter to replace or enhance the current on-site wastewater treatment drainfields was proposed in this study. Unit operation with known treatment efficiencies, flow pattern identification, and system dynamics modeling was cohesively concatenated in order to prove the concept of a newly developed media filter. A multicompartmental model addressing system dynamics and feedbacks based on our assumed microbiological processes accounting for aerobic, anoxic, and anaerobic conditions in the media filter was constructed and calibrated with the aid of in situ measurements and the understanding of the flow patterns. Such a calibrated system dynamics model was then applied for a sensitivity analysis under changing inflow conditions based on the rates of nitrification and denitrification characterized through the field-scale testing. This advancement may contribute to design such a drainfield media filter in household septic tank systems in the future.

Sampled data CT system including analog filter and compensating digital filter

International Nuclear Information System (INIS)

Glover, G. H.; DallaPiazza, D. G.; Pelc, N. J.

1985-01-01

A CT scanner in which the amount of x-ray information acquired per unit time is substantially increased by using a continuous-on x-ray source and a sampled data system with the detector. An analog filter is used in the sampling system for band limiting the detector signal below the highest frequency of interest, but is a practically realizable filter and is therefore non-ideal. A digital filter is applied to the detector data after digitization to compensate for the characteristics of the analog filter, and to provide an overall filter characteristic more nearly like the ideal

Potential for HEPA filter damage from water spray systems in filter plenums

Energy Technology Data Exchange (ETDEWEB)

Bergman, W. [Lawrence Livermore National Lab., CA (United States); Fretthold, J.K. [Rocky Flats Safe Sites of Colorado, Golden, CO (United States); Slawski, J.W. [Department of Energy, Germantown, MD (United States)

1997-08-01

The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for BEPA filter damage during fires has also occurred in the field. A fire in a four-stage, BEPA filter plenum at Rocky Flats in 1980 caused the first three stages of BEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenums, additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk. 22 refs., 15 figs.

Improved Kalman Filter Method for Measurement Noise Reduction in Multi Sensor RFID Systems

Directory of Open Access Journals (Sweden)

Min Chul Kim

2011-10-01

Full Text Available Recently, the range of available Radio Frequency Identification (RFID tags has been widened to include smart RFID tags which can monitor their varying surroundings. One of the most important factors for better performance of smart RFID system is accurate measurement from various sensors. In the multi-sensing environment, some noisy signals are obtained because of the changing surroundings. We propose in this paper an improved Kalman filter method to reduce noise and obtain correct data. Performance of Kalman filter is determined by a measurement and system noise covariance which are usually called the R and Q variables in the Kalman filter algorithm. Choosing a correct R and Q variable is one of the most important design factors for better performance of the Kalman filter. For this reason, we proposed an improved Kalman filter to advance an ability of noise reduction of the Kalman filter. The measurement noise covariance was only considered because the system architecture is simple and can be adjusted by the neural network. With this method, more accurate data can be obtained with smart RFID tags. In a simulation the proposed improved Kalman filter has 40.1%, 60.4% and 87.5% less Mean Squared Error (MSE than the conventional Kalman filter method for a temperature sensor, humidity sensor and oxygen sensor, respectively. The performance of the proposed method was also verified with some experiments.

Improved Kalman filter method for measurement noise reduction in multi sensor RFID systems.

Science.gov (United States)

Eom, Ki Hwan; Lee, Seung Joon; Kyung, Yeo Sun; Lee, Chang Won; Kim, Min Chul; Jung, Kyung Kwon

2011-01-01

Recently, the range of available radio frequency identification (RFID) tags has been widened to include smart RFID tags which can monitor their varying surroundings. One of the most important factors for better performance of smart RFID system is accurate measurement from various sensors. In the multi-sensing environment, some noisy signals are obtained because of the changing surroundings. We propose in this paper an improved Kalman filter method to reduce noise and obtain correct data. Performance of Kalman filter is determined by a measurement and system noise covariance which are usually called the R and Q variables in the Kalman filter algorithm. Choosing a correct R and Q variable is one of the most important design factors for better performance of the Kalman filter. For this reason, we proposed an improved Kalman filter to advance an ability of noise reduction of the Kalman filter. The measurement noise covariance was only considered because the system architecture is simple and can be adjusted by the neural network. With this method, more accurate data can be obtained with smart RFID tags. In a simulation the proposed improved Kalman filter has 40.1%, 60.4% and 87.5% less mean squared error (MSE) than the conventional Kalman filter method for a temperature sensor, humidity sensor and oxygen sensor, respectively. The performance of the proposed method was also verified with some experiments.

Parallel power electronics filters in three-phase four-wire systems principle, control and design

CERN Document Server

Wong, Man-Chung; Lam, Chi-Seng

2016-01-01

This book describes parallel power electronic filters for 3-phase 4-wire systems, focusing on the control, design and system operation. It presents the basics of power-electronics techniques applied in power systems as well as the advanced techniques in controlling, implementing and designing parallel power electronics converters. The power-quality compensation has been achieved using active filters and hybrid filters, and circuit models, control principles and operational practice problems have been verified by principle study, simulation and experimental results. The state-of-the-art research findings were mainly developed by a team at the University of Macau. Offering background information and related novel techniques, this book is a valuable resource for electrical engineers and researchers wanting to work on energy saving using power-quality compensators or renewable energy power electronics systems. .

Semiconductor cleaning liquid delivery system and its filter; Handotaiyo seijo yakueki kyokyu system to filter

Energy Technology Data Exchange (ETDEWEB)

Saito, T. [Kanto Chemical Co. Inc., Tokyo (Japan); Hayama, H.; Sakka, T. [Nitto Denko Corp., Osaka (Japan)

1994-11-30

Most of chemicals used for producing semiconductors are supplied automatically by a chemical delivery system to production devices. This paper explains the current status and the trends of the system. This system supplies the chemicals in the order of a tank lorry, a storage tank, a supply tank, a filter and a production device, and the transfer is performed receiving a supply signal from the supply tank and the production device. The transfer may be done through a dilution equipment. Filters currently used have membrane pore sizes of 0.2 to 0.1 microns as prefilters, and 0.1 to 0.05 microns as final filters. Chemicals used are diverse and can be divided into acid-, alkaline-, and solvent-based groups. Fluorine resin filters are used for acid- and alkaline-resistant applications, and SUS/fluorine resin filters for solvent-resistant applications. Use of large-sized filters of element construction with a membrane area of 1 m{sup 2} class is increasing recently in addition to selection from a performance viewpoint, including particle removing performance. 9 figs., 7 tabs.

Online remote radiological monitoring during operation of Advance Vitrification System (AVS), Tarapur

International Nuclear Information System (INIS)

Deokar, U.V.; Kulkarni, V.V.; Mathew, P.; Khot, A.R.; Singh, K.K.; Kamlesh; Deshpande, M.D.; Kulkarni, Y.

2010-01-01

Advanced Vitrification System (AVS) is commissioned for vitrification of high level waste (HLW) by using Joule heated ceramic melter first time in India. The HLW is generated in fuel reprocessing plant. For radiological surveillance of plant, Health Physics Unit (HPU) had installed 37 Area Gamma Monitors (AGM), 7 Continuous Air Monitors (CAM) and all types of personal contamination monitors. Exposure control is a major concern in operating plant. Therefore in addition to installed monitors, we have developed online remote radiation monitoring system to minimize exposures to the surveyor and operator. This also helped in volume reduction of secondary waste. The reliability and accuracy of the online monitoring system is confirmed by calibrating the system by comparing TLD and DRD readings and by theoretical analysis. In addition some modifications were carried in HP instruments to make them user friendly. This paper summarizes different kinds of remote radiological monitoring systems installed for online monitoring of Melter off Gas (MOG) filter, Hood filter, three exhaust filter banks, annulus air sampling and over pack monitoring in AVS. Our online remote monitoring system has helped the plant management to plan in advance for replacement of these filters, which resulted in considerable saving of collective dose. (author)

Notch filters for port-Hamiltonian systems

NARCIS (Netherlands)

Dirksz, D.A.; Scherpen, J.M.A.; van der Schaft, A.J.; Steinbuch, M.

2012-01-01

In this paper a standard notch filter is modeled in the port-Hamiltonian framework. By having such a port-Hamiltonian description it is proven that the notch filter is a passive system. The notch filter can then be interconnected with another (nonlinear) port-Hamiltonian system, while preserving the

Filter and window behavior for the Advanced Photon Source beamline front end

International Nuclear Information System (INIS)

Wang, Zhibi; Kuzay, T.M.; Shu, Deming; Dejus, R.

1993-01-01

Synchrotron x-ray windows are vacuum separators and are usually made of thin beryllium metal. Filters are provided upstream to absorb the soft x-rays so that the window is protected from overheating, which could result in failure. The filters are made of thin carbon products or sometimes beryllium, the same material as the window. Because the window is a vacuum separator, understanding its potential structural failure under thermal load is of utmost importance. The planned insertion devices and bending magnets for the Advanced Photon Source (APS) generate very high heat fluxes. To guarantee the integrity of the filter and window, extensive investigations have been carried out on both components. The material selection for filters and windows from among the possible candidate materials was investigated first. Then a series of thermal and structural analyses were performed on the filter and window. Results are presented from power absorption, analytical results from thermal, and structural analyses as well as application of the failure criteria suggested by Wang and Kuzay to the filters and windows

Filtering and control of wireless networked systems

CERN Document Server

Zhang, Dan; Yu, Li

2017-01-01

This self-contained book, written by leading experts, offers a cutting-edge, in-depth overview of the filtering and control of wireless networked systems. It addresses the energy constraint and filter/controller gain variation problems, and presents both the centralized and the distributed solutions. The first two chapters provide an introduction to networked control systems and basic information on system analysis. Chapters (3–6) then discuss the centralized filtering of wireless networked systems, presenting different approaches to deal with energy efficiency and filter/controller gain variation problems. The next part (chapters 7–10) explores the distributed filtering of wireless networked systems, addressing the main problems of energy constraint and filter gain variation. The final part (chapters 11–14) focuses on the distributed control of wireless networked systems. systems for communication and control applications, the bo...

Manipulation Robustness of Collaborative Filtering Systems

OpenAIRE

Benjamin Van Roy; Xiang Yan

2009-01-01

A collaborative filtering system recommends to users products that similar users like. Collaborative filtering systems influence purchase decisions, and hence have become targets of manipulation by unscrupulous vendors. We provide theoretical and empirical results demonstrating that while common nearest neighbor algorithms, which are widely used in commercial systems, can be highly susceptible to manipulation, two classes of collaborative filtering algorithms which we refer to as linear and a...

The ''Nuclear-Karlsruhe'' air-filter system

International Nuclear Information System (INIS)

Berliner, P.; Ohlmeyer, M.; Stotz, W.

1976-01-01

Increasing requirements for exhaust-air filter systems used in nuclear facilities induced the Gesellschaft fuer Kernforschung to develop the ''Nuclear-Karlsruhe'' HEPA filter system. This novel development has profited by experience gained in previous incidents as well as by maitenance and decontamination work performed with different HEPA filter systems. The proved ''Nuclear-Karlsruhe'' system takes equally into account the demands for optimum safety, maximum efficiency and economy, and is distinguished by the following features: (1) The air current is defected by 180 0 in the casing. Deflection causes quite a number of improvements, results in substantial reduction of space requirements, and avoids the dispersion of pollutants to the clean-air side. Besides, the HEPA filter is protected from damage by condensed particles or foreign materials entrained; (2) The ''Nuclear-Karlsruhe'' system allows gas-tight filter replacement. Special replacement collars have been provided at the casing, which allow the tight fastening of replacement bags which are self-locking. (3) In-place testing in the operating condition can be carried out very conveniently because the air is deflected. Minimum leaks in the filter medium or in the filter gasket can be detected by the high-sensitivity visual oil-thread test, which makes leaks distinctly visible as oil mist threads through a transparent front window provided on the clean-air side. The test takes only some minutes and its sensitivity is hardly matched by any other technique. (4) The clamping mechanism is installed outside the casing, i.e. outside the polluted or aggressive media. The contact force is spring-loaded absolutely uniformly to the circular filter gasket. (5) For practical and econmic reasons the filter casings can be locked individually so as to be gas-tight. (6) The entire system is made of stainless or coated steel and metal parts which are corrosion and fire-resistant. (author)

Advanced topics in control and estimation of state-multiplicative noisy systems

CERN Document Server

Gershon, Eli

2013-01-01

Advanced Topics in Control and Estimation of State-Multiplicative Noisy Systems begins with an introduction and extensive literature survey. The text proceeds to cover solutions of measurement-feedback control and state problems and the formulation of the Bounded Real Lemma for both continuous- and discrete-time systems. The continuous-time reduced-order and stochastic-tracking control problems for delayed systems are then treated. Ideas of nonlinear stability are introduced for infinite-horizon systems, again, in both the continuous- and discrete-time cases. The reader is introduced to six practical examples of noisy state-multiplicative control and filtering associated with various fields of control engineering. The book is rounded out by a three-part appendix containing stochastic tools necessary for a proper appreciation of the text: a basic introduction to nonlinear stochastic differential equations and aspects of switched systems and peak to peak  optimal control and filtering. Advanced Topics in Contr...

Object-oriented alarm-filtering system

International Nuclear Information System (INIS)

Corsberg, D.R.; Wilkie, D.

1986-01-01

This paper discusses an alarm-filtering system (AFS) being developed by EG and G Idaho, Inc. for the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory. The ultimate goal of this project is to place AFS into ATR's reactor control room to act as an aid during major plant transients. In addition, methods of alarm analysis are investigated based on functional relationships rather than on a historical approach utilizing cause-consequence trees. Artificial intelligence techniques, including object-oriented programming, are also demonstrated as useful in analyzing alarms and alarm sequences. After a brief description of the problem AFS addresses, this paper discusses the design constraints and human factors that influenced the development of the system. The reader is then presented with operational and architectural descriptions of the system as well as what directions the future development of AFS may take. The fact that AFS is being considered as a partial solution to the problems discussed in the next section demonstrates the viability of its underlying technology and approach. 10 refs

Implicit Particle Filter for Power System State Estimation with Large Scale Renewable Power Integration.

Science.gov (United States)

Uzunoglu, B.; Hussaini, Y.

2017-12-01

Implicit Particle Filter is a sequential Monte Carlo method for data assimilation that guides the particles to the high-probability by an implicit step . It optimizes a nonlinear cost function which can be inherited from legacy assimilation routines . Dynamic state estimation for almost real-time applications in power systems are becomingly increasingly more important with integration of variable wind and solar power generation. New advanced state estimation tools that will replace the old generation state estimation in addition to having a general framework of complexities should be able to address the legacy software and able to integrate the old software in a mathematical framework while allowing the power industry need for a cautious and evolutionary change in comparison to a complete revolutionary approach while addressing nonlinearity and non-normal behaviour. This work implements implicit particle filter as a state estimation tool for the estimation of the states of a power system and presents the first implicit particle filter application study on a power system state estimation. The implicit particle filter is introduced into power systems and the simulations are presented for a three-node benchmark power system . The performance of the filter on the presented problem is analyzed and the results are presented.

Novel fabrication method of the peritoneal dialysis filter using silk fibroin with urease fixation system.

Science.gov (United States)

Moon, Bo Mi; Choi, Myung-Jin; Sultan, Md Tipu; Yang, Jae Won; Ju, Hyung Woo; Lee, Jung Min; Park, Hyun Jung; Park, Ye Ri; Kim, Soo Hyeon; Kim, Dong Wook; Lee, Min Chae; Jeong, Ju Yeon; Lee, Ok Joo; Sung, Gun Yong; Park, Chan Hum

2017-10-01

During the last decade, there has been a great advance in the kidney dialysis system by wearable artificial kidney (WAK) system for end-stage renal disease patients. Uremic solute removal and water regeneration system are the most prerequisite for WAK to work properly. In this study, we designed a filtering membrane system by using immobilized urease silk fibroin filter and evaluated its comparative effectiveness with a PVDF filtering system in peritoneal dialysate regeneration system by urea removal efficacy. We evaluated this membrane's characteristic and performances by conducting SEM-EDX analyze, water-binding abilities and porosity test, removal abilities of urea, cytotoxicity assay and enzyme activity assay. Under the condition for optimization of urease, the percentage removal of urea was about 40% and 60% in 50 mg/dL urea solution by urease immobilized PVDF and silk fibroin scaffolds, respectively. The batch experimental result showed that immobilized filter removed more than 50% of urea in 50 mg/dL urea solution. In addition silk fibroin with urease filter removed 90 percent of urea in the peritoneal dialysate after 24 h filtration. We suggest that silk fibroin with urease fixation filter can be used more effectively for peritoneal dialysate regeneration system, which have hydrophilic property and prolonged enzyme activity. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2136-2144, 2017. © 2016 Wiley Periodicals, Inc.

Factors Associated with Advanced Inferior Vena Cava Filter Removals: A Single-Center Retrospective Study of 203 Patients Over 7 Years

Energy Technology Data Exchange (ETDEWEB)

Dowell, Joshua D., E-mail: Joshua.Dowell@osumc.edu; Wagner, Daniel, E-mail: Daniel.Wagner@osumc.edu; Elliott, Eric, E-mail: Eric.Elliott@osumc.edu [The Ohio State University Wexner Medical Center, Department of Radiology, Division of Interventional Radiology (United States); Yildiz, Vedat O., E-mail: Vedat.Yildiz@osumc.edu; Pan, Xueliang, E-mail: Jeff.Pan@osumc.edu [The Ohio State University Wexner Medical Center, Center for Biostatistics (United States)

2016-02-15

PurposeTo identify factors associated with advanced inferior vena cava filter (IVCF) retrieval to raise awareness on technical considerations, retrieval efficiency, and patient safety.Materials and MethodsA single-center retrospective review was performed of 203 consecutive retrievable IVC filters placed between 2007 and 2014. Attempted retrievals were classified as advanced if the routine “snare and sheath” technique was initially unsuccessful after multiple attempts, or an alternate endovascular maneuver or access site was utilized. Patient and filter characteristics were recorded.Results203 attempted retrievals were reviewed (48.7 % male, 51.2 % female, mean age 52.7 years, mean dwell time 109 days). Advanced retrievals were observed in 20 patients (9.8 %) (15 females, 5 males). Fluoroscopy time (p ≤ 0.01, 34.3 ± 21.1 and 5.3 ± 4.5 min for advanced retrievals and routine retrievals respectively, same below), gender (p = 0.031), and retrieval tilt angle (p ≤ 0.01, 5.7 ± 5.10° vs. 11.9 ± 11.03°) were associated with advanced retrievals. Females were 3.16 times more likely to have an advanced retrieval performed than males with a significantly higher tilt angle in those with advanced retrieval. History of cancer (p = 0.502), dwell time (p = 0.916), retrieval caval diameter (p = 0.053), placement caval diameter (p = 0.365), filter type (p = 0.710), strut perforation (p = 0.506), placement tilt angle (p = 0.311), and age (p = 0.558) were not found significantly associated with advanced retrievals.ConclusionsWomen are at increased risk for advanced filter retrieval secondary to a significant change in filter tilt over time compared to men, independent of filter type or competing demographic or filter risks, likely placing them at increased risk for higher procedural fluoroscopy times.

Factors Associated with Advanced Inferior Vena Cava Filter Removals: A Single-Center Retrospective Study of 203 Patients Over 7 Years

International Nuclear Information System (INIS)

Dowell, Joshua D.; Wagner, Daniel; Elliott, Eric; Yildiz, Vedat O.; Pan, Xueliang

2016-01-01

PurposeTo identify factors associated with advanced inferior vena cava filter (IVCF) retrieval to raise awareness on technical considerations, retrieval efficiency, and patient safety.Materials and MethodsA single-center retrospective review was performed of 203 consecutive retrievable IVC filters placed between 2007 and 2014. Attempted retrievals were classified as advanced if the routine “snare and sheath” technique was initially unsuccessful after multiple attempts, or an alternate endovascular maneuver or access site was utilized. Patient and filter characteristics were recorded.Results203 attempted retrievals were reviewed (48.7 % male, 51.2 % female, mean age 52.7 years, mean dwell time 109 days). Advanced retrievals were observed in 20 patients (9.8 %) (15 females, 5 males). Fluoroscopy time (p ≤ 0.01, 34.3 ± 21.1 and 5.3 ± 4.5 min for advanced retrievals and routine retrievals respectively, same below), gender (p = 0.031), and retrieval tilt angle (p ≤ 0.01, 5.7 ± 5.10° vs. 11.9 ± 11.03°) were associated with advanced retrievals. Females were 3.16 times more likely to have an advanced retrieval performed than males with a significantly higher tilt angle in those with advanced retrieval. History of cancer (p = 0.502), dwell time (p = 0.916), retrieval caval diameter (p = 0.053), placement caval diameter (p = 0.365), filter type (p = 0.710), strut perforation (p = 0.506), placement tilt angle (p = 0.311), and age (p = 0.558) were not found significantly associated with advanced retrievals.ConclusionsWomen are at increased risk for advanced filter retrieval secondary to a significant change in filter tilt over time compared to men, independent of filter type or competing demographic or filter risks, likely placing them at increased risk for higher procedural fluoroscopy times

Very High-Performance Advanced Filter Bank Analog-to-Digital Converter (AFB ADC) Project

National Research Council Canada - National Science Library

Velazquez, Scott

1999-01-01

... of the art by using a parallel array of individual commercial off the shelf converters. The significant performance improvements afforded by the Advanced Filter Bank Analog to Digital Converter (AFB ADC...

Humanoid Robot Control System Balance Dance Indonesia and Reader Filters Using Complementary Angle Values

Science.gov (United States)

Sholihin; Susanti, Eka

2018-02-01

The development of increasingly advanced technology, make people want to be more developed and curiosity to know more to determine the development of advanced technology. Robot is a tool that can be used as a tool for people who have several advantages. Basically humanoid robot is a robot that resembles a human being with all the driving structure. In the application of this humanoid robot manufacture researchers use MPU6050 module which is an important component of the robot because it can provide a response to the angle reference axis X and Y reference axis, the reading corner still has noise if not filtered out beforehand. On the other hand the use of Complementary filters are the answer to reduce the noise. By arranging the filter coefficients and time sampling filter that affects the signal updates corner. The angle value will be the value of the sensor to the process to the PID system which generates output values that are integrated with the servo pulses. Researchers will test to get a reading of the most stable angle for this experiment is the "a" or the value of the filter coefficient = 0.96 and "dt" or the sampling time = 10 ms.

International Space Station (ISS) Advanced Recycle Filter Tank Assembly (ARFTA)

Science.gov (United States)

Nasrullah, Mohammed K.

2013-01-01

The International Space Station (ISS) Recycle Filter Tank Assembly (RFTA) provides the following three primary functions for the Urine Processor Assembly (UPA): volume for concentrating/filtering pretreated urine, filtration of product distillate, and filtration of the Pressure Control and Pump Assembly (PCPA) effluent. The RFTAs, under nominal operations, are to be replaced every 30 days. This poses a significant logistical resupply problem, as well as cost in upmass and new tanks purchase. In addition, it requires significant amount of crew time. To address and resolve these challenges, NASA required Boeing to develop a design which eliminated the logistics and upmass issues and minimize recurring costs. Boeing developed the Advanced Recycle Filter Tank Assembly (ARFTA) that allowed the tanks to be emptied on-orbit into disposable tanks that eliminated the need for bringing the fully loaded tanks to earth for refurbishment and relaunch, thereby eliminating several hundred pounds of upmass and its associated costs. The ARFTA will replace the RFTA by providing the same functionality, but with reduced resupply requirements

Filter indexing for spectrophotometer system

International Nuclear Information System (INIS)

Chamran, M.M.; Scott, L.B.; Williams, P.B.

1982-01-01

A spectrophotometer system has an optical system for transmitting a beam from a source at select wavelengths onto a detector. A plurality of filters are positioned in a tray. A stepper mechanism indexes the tray along a path. A microcomputer controls the stepper mechanism and the optical system. The wavelength is successively changed over a range, the tray is indexed to move a select filter into the beam at a predetermined wavelength and the changing is discontinued during indexing

Orthonormal filters for identification in active control systems

International Nuclear Information System (INIS)

Mayer, Dirk

2015-01-01

Many active noise and vibration control systems require models of the control paths. When the controlled system changes slightly over time, adaptive digital filters for the identification of the models are useful. This paper aims at the investigation of a special class of adaptive digital filters: orthonormal filter banks possess the robust and simple adaptation of the widely applied finite impulse response (FIR) filters, but at a lower model order, which is important when considering implementation on embedded systems. However, the filter banks require prior knowledge about the resonance frequencies and damping of the structure. This knowledge can be supposed to be of limited precision, since in many practical systems, uncertainties in the structural parameters exist. In this work, a procedure using a number of training systems to find the fixed parameters for the filter banks is applied. The effect of uncertainties in the prior knowledge on the model error is examined both with a basic example and in an experiment. Furthermore, the possibilities to compensate for the imprecise prior knowledge by a higher filter order are investigated. Also comparisons with FIR filters are implemented in order to assess the possible advantages of the orthonormal filter banks. Numerical and experimental investigations show that significantly lower computational effort can be reached by the filter banks under certain conditions. (paper)

Protein-Nanocellulose Interactions in Paper Filters for Advanced Separation Applications.

Science.gov (United States)

Gustafsson, Simon; Manukyan, Levon; Mihranyan, Albert

2017-05-16

Protein-based pharmaceutics are widely explored for healthcare applications, and 6 out of 10 best-selling drugs today are biologicals. The goal of this work was to evaluate the protein nanocellulose interactions in paper filter for advanced separation applications such as virus removal filtration and bioprocessing. The protein recovery was measured for bovine serum albumin (BSA), γ-globulin, and lysozyme using biuret total protein reagent and polyacrylamide gel electrophoresis (PAGE), and the throughput was characterized in terms of flux values from fixed volume filtrations at various protein concentrations and under worst-case experimental conditions. The affinity of cellulose to bind various proteins, such as BSA, lysozyme, γ-globulin, and human IgG was quantified using a quartz crystal microbalance (QCMB) by developing a new method of fixing the cellulose fibers to the electrode surface without cellulose dissolution-precipitation. It was shown that the mille-feuille filter exhibits high protein recovery, that is, ∼99% for both BSA and lysozyme. However, γ-globulin does not pass through the membrane due to its large size (i.e., >180 kDa). The PAGE data show no substantial change in the amount of dimers and trimers before and after filtration. QCMB analysis suggests a low affinity between the nanocellulose surface and proteins. The nanocellulose-based filter exhibits desirable inertness as a filtering material intended for protein purification.

Filter system for purifying gas or air streams

International Nuclear Information System (INIS)

Ohlmeyer, M.; Wilhelm, J.

1981-01-01

A filter system is provided for purifying a gas stream by means of flowable or tricklable contact filter material, wherein the stream flows through the filter material and the filter material forms a movable bed. The system contains a filter chamber through which the filter material can flow and which is provided with an inlet opening and an outlet opening for the filter material between which the filter material is conveyed by gravity. The filter system includes deflection means for deflecting the stream , after a first passage of the stream through the filter bed to charge the filter bed for a first time, to a position above where the stream first passed through the filter bed and for conducting the stream at least once again transversely through the filter bed above the first charge so that the filter bed is charged a second time. The filter chamber contains a first opening where the stream enters the filter bed for the first time and is aligned with the deflection means, and a second opening aligned with the deflection means and above the first opening. The second opening is located where the stream leaves the filter bed for the second time, with a partial quantity of the gas stream being able to pass directly through the filter bed from the first opening to the second opening without going through the deflection means. The distance between the upper edge of the first opening and the lower edge of the second opening is at least twice the thickness of the filter chamber

In-situ testing of HEPA filters in the nuclear Karlsruhe filter system

International Nuclear Information System (INIS)

Ohlmeyer, M.; Stotz, W.

1977-01-01

Nuclear plant operators and filter manufacturers are endeavouring to improve environmental protection by intensifying process control and/or improving filter quality. In-situ testing is an important element in these efforts since it represents a direct means of checking the success or otherwise of a particular development. The arrangements for in-situ testing should satisfy the following minimum requirements: the staff should not be exposed to risk during the test; the test method should be objective and reproducible as well as being as sensitive as possible; the test method should permit detection of individual leaks in the filter system so that they can be remedied as efficiently as possible; the test equipment should not necessitate modifications to the extract systems or plant construction; the test should be simple and capable of being carried out with a minimum of effort and equipment. GfK has developed the 'Nuclear-Karlsruhe' filter housing in accordance with these principles. This housing permits in-situ testing similar to the DIN 24184 visual oil-fog test or the DOP test. External visual checks on the general condition of the filter is also possible. A safe system of filter changing with a specially designed plastic bag attachment at an accessible height considerably increases the degree of protection of operating personnel

Testing Of The Dual Rotary Filter System

International Nuclear Information System (INIS)

Herman, D.; Fowley, M.; Stefanko, D.

2011-01-01

The Savannah River National Laboratory (SRNL) installed and tested two hydraulically connected SpinTek rotary microfilter (RMF) units to determine the behavior of a multiple filter system. Both units were successfully controlled by a control scheme written in DELTA-V architecture by Savannah River Remediation (SRR) Process Control Engineering personnel. The control system was tuned to provide satisfactory response to changing conditions during the operation of the multi-filter system. Stability was maintained through the startup and shutdown of one of the filter units while the second was still in operation. The installation configuration originally proposed by the Small Colum Ion Exchange (SCIX) project of independent filter and motor mountings may be susceptible to vibration. Significant stiffening of the filter and motor mounts was required to minimize the vibration. Alignment of the motor to the filter was a challenge in this test configuration. The deployment configuration must be easy to manipulate and allow for fine adjustment. An analysis of the vibration signature of the test system identified critical speeds. Whether it corresponds to the resonance frequency of a rotor radial vibration mode that was excited by rotor unbalance is uncertain based upon the measurements. A relative motion series should be completed on the filter with the final shaft configuration to determine if the resonances exist in the final filter design. The instrumentation selected for deployment, including the concentrate discharge control valve and flow meters, performed well. Automation of the valve control integrated well with the control scheme and when used in concert with the other control variables, allowed automated control of the dual RMF system. The one area of concern with the instrumentation was the condition resulting when the filtrate flow meter operated with less than three gpm. This low flow was at the lower range of performance for the flow meter. This should not be

TESTING OF THE DUAL ROTARY FILTER SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Herman, D.; Fowley, M.; Stefanko, D.

2011-08-29

The Savannah River National Laboratory (SRNL) installed and tested two hydraulically connected SpinTek rotary microfilter (RMF) units to determine the behavior of a multiple filter system. Both units were successfully controlled by a control scheme written in DELTA-V architecture by Savannah River Remediation (SRR) Process Control Engineering personnel. The control system was tuned to provide satisfactory response to changing conditions during the operation of the multi-filter system. Stability was maintained through the startup and shutdown of one of the filter units while the second was still in operation. The installation configuration originally proposed by the Small Colum Ion Exchange (SCIX) project of independent filter and motor mountings may be susceptible to vibration. Significant stiffening of the filter and motor mounts was required to minimize the vibration. Alignment of the motor to the filter was a challenge in this test configuration. The deployment configuration must be easy to manipulate and allow for fine adjustment. An analysis of the vibration signature of the test system identified critical speeds. Whether it corresponds to the resonance frequency of a rotor radial vibration mode that was excited by rotor unbalance is uncertain based upon the measurements. A relative motion series should be completed on the filter with the final shaft configuration to determine if the resonances exist in the final filter design. The instrumentation selected for deployment, including the concentrate discharge control valve and flow meters, performed well. Automation of the valve control integrated well with the control scheme and when used in concert with the other control variables, allowed automated control of the dual RMF system. The one area of concern with the instrumentation was the condition resulting when the filtrate flow meter operated with less than three gpm. This low flow was at the lower range of performance for the flow meter. This should not be

Turbulence-cascade interaction noise using an advanced digital filter method

OpenAIRE

Gea Aguilera, Fernando; Gill, James; Zhang, Xin; Nodé-Langlois, Thomas

2016-01-01

Fan wakes interacting with outlet guide vanes is a major source of noise in modern turbofan engines. In order to study this source of noise, the current work presents two-dimensional simulations of turbulence-cascade interaction noise using a computational aeroacoustic methodology. An advanced digital filter method is used for the generation of isotropic synthetic turbulence in a linearised Euler equation solver. A parameter study is presented to assess the influence of airfoil thickness, mea...

High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

1997-12-11

This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

Adaptive Federal Kalman Filtering for SINS/GPS Integrated System

Institute of Scientific and Technical Information of China (English)

杨勇; 缪玲娟

2003-01-01

A new adaptive federal Kalman filter for a strapdown integrated navigation system/global positioning system (SINS/GPS) is given. The developed federal Kalman filter is based on the trace operation of parameters estimation's error covariance matrix and the spectral radius of update measurement noise variance-covariance matrix for the proper choice of the filter weight and hence the filter gain factors. Theoretical analysis and results from simulation in which the SINS/GPS was compared to conventional Kalman filter are presented. Results show that the algorithm of this adaptive federal Kalman filter is simpler than that of the conventional one. Furthermore, it outperforms the conventional Kalman filter when the system is undertaken measurement malfunctions because of its possession of adaptive ability. This filter can be used in the vehicle integrated navigation system.

Advanced photonic filters based on cascaded Sagnac loop reflector resonators in silicon-on-insulator nanowires

Science.gov (United States)

Wu, Jiayang; Moein, Tania; Xu, Xingyuan; Moss, David J.

2018-04-01

We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI) nanowires implemented by cascaded Sagnac loop reflector (CSLR) resonators. We investigate mode splitting in these standing-wave (SW) resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs) and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.

Design and implementation of predictive filtering system for current reference generation of active power filter

Energy Technology Data Exchange (ETDEWEB)

Kilic, Tomislav; Milun, Stanko; Petrovic, Goran [FESB University of Split, Faculty of Electrical Engineering, Machine Engineering and Naval Architecture, R. Boskovica bb, 21000, Split (Croatia)

2007-02-15

The shunt active power filters are used to attenuate the harmonic currents in power systems by injecting equal but opposite compensating currents. Successful control of the active filters requires an accurate current reference. In this paper the current reference determination based on predictive filtering structure is presented. Current reference was obtained by taking the difference of load current and its fundamental harmonic. For fundamental harmonic determination with no time delay a combination of digital predictive filter and low pass filter is used. The proposed method was implemented on a laboratory prototype of a three-phase active power filter. The algorithm for current reference determination was adapted and implemented on DSP controller. Simulation and experimental results show that the active power filter with implemented predictive filtering structure gives satisfactory performance in power system harmonic attenuation. (author)

Robust filtering for uncertain systems a parameter-dependent approach

CERN Document Server

Gao, Huijun

2014-01-01

This monograph provides the reader with a systematic treatment of robust filter design, a key issue in systems, control and signal processing, because of the fact that the inevitable presence of uncertainty in system and signal models often degrades the filtering performance and may even cause instability. The methods described are therefore not subject to the rigorous assumptions of traditional Kalman filtering. The monograph is concerned with robust filtering for various dynamical systems with parametric uncertainties, and focuses on parameter-dependent approaches to filter design. Classical filtering schemes, like H2 filtering and H¥ filtering, are addressed, and emerging issues such as robust filtering with constraints on communication channels and signal frequency characteristics are discussed. The text features: ·        design approaches to robust filters arranged according to varying complexity level, and emphasizing robust filtering in the parameter-dependent framework for the first time; ·...

Advanced photonic filters based on cascaded Sagnac loop reflector resonators in silicon-on-insulator nanowires

Directory of Open Access Journals (Sweden)

Jiayang Wu

2018-04-01

Full Text Available We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI nanowires implemented by cascaded Sagnac loop reflector (CSLR resonators. We investigate mode splitting in these standing-wave (SW resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.

Comparison of robust H∞ filter and Kalman filter for initial alignment of inertial navigation system

Institute of Scientific and Technical Information of China (English)

HAO Yan-ling; CHEN Ming-hui; LI Liang-jun; XU Bo

2008-01-01

There are many filtering methods that can be used for the initial alignment of an integrated inertial navigation system.This paper discussed the use of GPS,but focused on two kinds of filters for the initial alignment of an integrated strapdown inertial navigation system (SINS).One method is based on the Kalman filter (KF),and the other is based on the robust filter.Simulation results showed that the filter provides a quick transient response and a little more accurate estimate than KF,given substantial process noise or unknown noise statistics.So the robust filter is an effective and useful method for initial alignment of SINS.This research should make the use of SINS more popular,and is also a step for further research.

Advanced configuration of hybrid passive filter for reactive power and harmonic compensation

OpenAIRE

Kececioglu, O. Fatih; Acikgoz, Hakan; Sekkeli, Mustafa

2016-01-01

Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. ...

Kalman Filtering for Delayed Singular Systems with Multiplicative Noise

Institute of Scientific and Technical Information of China (English)

Xiao Lu; Linglong Wang; Haixia Wang; Xianghua Wang

2016-01-01

Kalman filtering problem for singular systems is dealt with,where the measurements consist of instantaneous measurements and delayed ones,and the plant includes multiplicative noise.By utilizing standard singular value decomposition,the restricted equivalent delayed system is presented,and the Kalman filters for the restricted equivalent system are given by using the well-known re-organization of innovation analysis lemma.The optimal Kalman filter for the original system is given based on the above Kalman filter by recursive Riccati equations,and a numerical example is presented to show the validity and efficiency of the proposed approach,where the comparison between the filter and predictor is also given.

Kalman Filtering for Delayed Singular Systems with Multiplicative Noise

Institute of Scientific and Technical Information of China (English)

Xiao Lu; Linglong Wang; Haixia Wang; Xianghua Wang

2016-01-01

Kalman filtering problem for singular systems is dealt with, where the measurements consist of instantaneous measurements and delayed ones, and the plant includes multiplicative noise. By utilizing standard singular value decomposition, the restricted equivalent delayed system is presented, and the Kalman filters for the restricted equivalent system are given by using the well-known re-organization of innovation analysis lemma. The optimal Kalman filter for the original system is given based on the above Kalman filter by recursive Riccati equations, and a numerical example is presented to show the validity and efficiency of the proposed approach, where the comparison between the filter and predictor is also given.

Off-gas filter system of the SNR-300

International Nuclear Information System (INIS)

Boehm, L.; Jordan, S.; Schikarski, W.

1975-01-01

The Reventing-Exventing-System of the German Liquid Metal Fast Breeder Prototype SNR-300 is described. After an accident with major damage to the core the ventilation valves are quickly closed. At the same time the blower of the reventing system evacuates the reventing gap up to a pressure difference of 2 mbar between the containment and the outer atmosphere. This pressure difference prevents a leakage from the containment to the outside. The revented gas is recirculated into the outer-containment. Leaks from the atmosphere and possibly from the inner containment into the reventing gap increase the pressure in the outer-containment. Therefore depending on the pressure build-up which is determined by the course of the accident, it is necessary to exvent the containment after several days. The exvented gas is filtered by a filter combination consisting of pre-filters, charcoal-filters and HEPA-filters. Because accidental sodium fires produce high concentrations of sodium oxide-aerosols this filter system must resist chemical aggressive aerosols. (U.S.)

Advanced dust monitoring system applied to new TRU handling facility of JAERI

International Nuclear Information System (INIS)

Yabuta, H.; Shigeta, Y.; Sawahata, K.; Hasegawa, K.

1993-01-01

In JAERI, a large, scale multipurpose facility is under construction, which consists of a TRU waste management testing installation, a solution fuel treatment installation and critical assemblies with uranium and/or plutonium solution fuel. The facility is also equipped with a lot of gloveboxes for handling and treatment of solution fuel and hot cells for research on reprocessing process. As there may be a relatively high potential of air contamination, it is important to monitor air contamination effectively and efficiently. An advanced dust monitoring system was introduced for convenience of handling and automatical measurement of filter papers, by developing a filter-holder with an IC memory and a radioactivity measuring device with an automatic filter-holder changing mechanism as a part of a centralized monitoring system with a computer

? filtering for stochastic systems driven by Poisson processes

Science.gov (United States)

Song, Bo; Wu, Zheng-Guang; Park, Ju H.; Shi, Guodong; Zhang, Ya

2015-01-01

This paper investigates the ? filtering problem for stochastic systems driven by Poisson processes. By utilising the martingale theory such as the predictable projection operator and the dual predictable projection operator, this paper transforms the expectation of stochastic integral with respect to the Poisson process into the expectation of Lebesgue integral. Then, based on this, this paper designs an ? filter such that the filtering error system is mean-square asymptotically stable and satisfies a prescribed ? performance level. Finally, a simulation example is given to illustrate the effectiveness of the proposed filtering scheme.

Analog filters in nanometer CMOS

CERN Document Server

Uhrmann, Heimo; Zimmermann, Horst

2014-01-01

Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

Proposing Wavelet-Based Low-Pass Filter and Input Filter to Improve Transient Response of Grid-Connected Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Bijan Rahmani

2016-08-01

Full Text Available Available photovoltaic (PV systems show a prolonged transient response, when integrated into the power grid via active filters. On one hand, the conventional low-pass filter, employed within the integrated PV system, works with a large delay, particularly in the presence of system’s low-order harmonics. On the other hand, the switching of the DC (direct current–DC converters within PV units also prolongs the transient response of an integrated system, injecting harmonics and distortion through the PV-end current. This paper initially develops a wavelet-based low-pass filter to improve the transient response of the interconnected PV systems to grid lines. Further, a damped input filter is proposed within the PV system to address the raised converter’s switching issue. Finally, Matlab/Simulink simulations validate the effectiveness of the proposed wavelet-based low-pass filter and damped input filter within an integrated PV system.

Staged fluidized-bed combustion and filter system

International Nuclear Information System (INIS)

Mei, J.S.; Halow, J.S.

1994-01-01

A staged fluidized-bed combustion and filter system are described for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste. 10 figures

Kinematic Localization for Global Navigation Satellite Systems: A Kalman Filtering Approach

Science.gov (United States)

Tabatabaee, Mohammad Hadi

Use of the Global Positioning System (GNSS) has expanded significantly in the past decade, especially with advances in embedded systems and the emergence of smartphones and the Internet of Things (IoT). The growing demand has stimulated research on development of GNSS techniques and programming tools. The focus of much of the research efforts have been on high-level algorithms and augmentations. This dissertation focuses on the low-level methods at the heart of GNSS systems and proposes a new methods for GNSS positioning problems based on concepts of distance geometry and the use of Kalman filters. The methods presented in this dissertation provide algebraic solutions to problems that have predominantly been solved using iterative methods. The proposed methods are highly efficient, provide accurate estimates, and exhibit a degree of robustness in the presence of unfavorable satellite geometry. The algorithm operates in two stages; an estimation of the receiver clock bias and removal of the bias from the pseudorange observables, followed by the localization of the GNSS receiver. The use of a Kalman filter in between the two stages allows for an improvement of the clock bias estimate with a noticeable impact on the position estimates. The receiver localization step has also been formulated in a linear manner allowing for the direct application of a Kalman filter without any need for linearization. The methodology has also been extended to double differential observables for high accuracy pseudorange and carrier phase position estimates.

Thermo-mechanical analysis of a user filter assembly for undulator/wiggler operations at the Advanced Photon Source

International Nuclear Information System (INIS)

Nian, H.L.T.; Kuzay, T.M.; Collins, J.; Shu, D.; Benson, C.; Dejus, R.

1996-01-01

This paper reports a thermo-mechanical study of a beamline filter (user filter) for undulator/wiggler operations. It is deployed in conjunction with the current commissioning window assembly on the APS insertion device (ID) front ends. The beamline filter at the Advanced Photon Source (APS) will eventually be used in windowless operations also. Hence survival and reasonable life expectancy of the filters under intense insertion device (ID) heat flu are crucial to the beamline operations. To accommodate various user requirements, the filter is configured to be a multi-choice type and smart to allow only those filter combinations that will be safe to operate with a given ring current and beamline insertion device gap. However, this paper addresses only the thermo-mechanical analysis of individual filter integrity and safety in all combinations possible. The current filter design is configured to have four filter frames in a cascade with each frame holding five filters. This allows a potential 625 total filter combinations. Thermal analysis for all of these combinations becomes a mammoth task considering the desired choices for filter materials (pyrolitic graphite and metallic filters), filter thicknesses, undulator gaps, and the beam currents. The paper addresses how this difficult task has been reduced to a reasonable effort and computational level. Results from thermo-mechanical analyses of the filter combinations are presented both in tabular and graphical format

Rotating Ceramic Water Filter Discs System for Water Filtration

Directory of Open Access Journals (Sweden)

Riyadh Z. Al Zubaidy

2017-04-01

Full Text Available This work aimed to design, construct and operate a new laboratory scale water filtration system. This system was used to examine the efficiency of two ceramic filter discs as a medium for water filtration. These filters were made from two different ceramic mixtures of local red clay, sawdust, and water. The filtration system was designed with two rotating interfered modules of these filters. Rotating these modules generates shear force between water and the surfaces of filter discs of the filtration modules that works to reduce thickness of layer of rejected materials on the filters surfaces. Each module consists of seven filtration units and each unit consists of two ceramic filter discs. The average measured hydraulic conductivity of the first module was 13.7mm/day and that for the second module was 50mm/day. Results showed that the water filtration system can be operated continuously with a constant flow rate and the filtration process was controlled by a skin thin layer of rejected materials. The ceramic water filters of both filtration modules have high removal efficiency of total suspended solids up to 100% and of turbidity up to 99.94%.

Decontamination factors of ceramic filter in radioactive waste incineration system

International Nuclear Information System (INIS)

Kanbe, Hiromi; Mayuzumi, Masami; Ono, Tetsuo; Yoshiki, Shinya; Kouyama, Hiroaki; Nagae, Madoka; Sekiguchi, Ryosaku; Takaoku, Yoshinobu; Hozumi, Masahiro.

1987-01-01

A suspension-firing type radioactive waste incineration system is developed and cold demonstration testing of ceramic filters for the system are carried out. The incineration system, which is useful for a wide variety of waste materials, can serve to simplify the facilities and to reduce the costs for waste disposal. The incineration system can be used for drying-processing of concentrated waste liquids and disposal of flame resistant materials including ion exchange resins and rubber, as well as for ordinary combustible solid materials. An on-line backwash system is adopted to allow the ceramic filters to operate stably for a long period of time. For one-step filtering using the ceramic filter, the decontamination factor is greater than 10 5 for the processing of various wastes. In a practical situation, there exist vapor produced by the spray drier and the cladding in used ion exchange resin, which act to increase the decontamination performance of the ceramic filters to ensure safe operation. For the waste incineration system equipped with a waste gas processing apparatus consisting of a ceramic filter and HEPA filter, the overall decontamination factor is expected to be greater than 10 6 at portions down to the outlet of the ceramic filter and greater than 10 8 at portions down to the outlet of the HEPA filter. (Nogami, K.)

Optimization of the reconstruction and anti-aliasing filter in a Wiener filter system

NARCIS (Netherlands)

Wesselink, J.M.; Berkhoff, Arthur P.

2006-01-01

This paper discusses the influence of the reconstruction and anti-aliasing filters on the performance of a digital implementation of a Wiener filter for active noise control. The overall impact will be studied in combination with a multi-rate system approach. A reconstruction and anti-aliasing

Takagi-Sugeno Fuzzy Systems Non-fragile H-infinity Filtering

CERN Document Server

Chang, Xiao-Heng

2012-01-01

"Takagi-Sugeno Fuzzy Systems Non-fragile H-infinity Filtering" investigates the problem of non-fragile H-infinity filter design for T-S fuzzy systems. The nonlinear plant is represented by a T-S fuzzy model. Given a T-S fuzzy system, the objective of this book is to design an H-infinity filter with the gain variations such that the filtering error system guarantees a prescribed H-infinity performance level. Furthermore, it demonstrates that the solution of non-fragile H-infinity filter design problem can be obtained by solving a set of linear matrix inequalities (LMIs). The intended audiences are graduate students and researchers both from the fields of engineering and mathematics. Dr. Xiao-Heng Chang is an Associate Professor at the College of Engineering, Bohai University, Jinzhou, Liaoning, China. He is also a Postdoctoral Researcher at the College of Information Science and Engineering, Northeastern University, Shenyang, China.

The filtered venting system under construction at barseback

International Nuclear Information System (INIS)

Persson, A.H.

1985-01-01

A filter venting containment system, bearing the acronym FILTRA will be installed at the Swedish nuclear power plant Barseback. The Barseback Power Plant is owned by the Southern Sweden Power Supply (Sydkraft AB) and has two 1700-MW boiling water reactors. The reactors are of ASEA-ATOM design with pressure suppression containments (Mark IItype). The installation of the filter venting system is a condition set by the Swedish government for a continued operating license after September 1, 1986. The construction work for the FILTRA plant, the first of its kind ever planned, will be completed at the end of 1985. The FILTRA is designed so that 99.9% of the core inventory of radioactivity, excluding inert gases, is retained in the reactor containment and filter system in the event of containment venting. Another design guideline is to achieve passive functioning of the FILTRA plant during the first 24 h of an accident. The FILTRA plant is common to the two reactors on the site and consists mainly of two systems, a venting system (pressure relief system) and a filtering system. The total cost is approximately U.S. $15 million

Stochastic processes and filtering theory

CERN Document Server

Jazwinski, Andrew H

1970-01-01

This unified treatment of linear and nonlinear filtering theory presents material previously available only in journals, and in terms accessible to engineering students. Its sole prerequisites are advanced calculus, the theory of ordinary differential equations, and matrix analysis. Although theory is emphasized, the text discusses numerous practical applications as well.Taking the state-space approach to filtering, this text models dynamical systems by finite-dimensional Markov processes, outputs of stochastic difference, and differential equations. Starting with background material on probab

Cleanable sintered metal filters in hot off-gas systems

International Nuclear Information System (INIS)

Schurr, G.A.

1981-01-01

Filters with sintered metal elements, arranged as tube bundles with backflush air cleaning, are the equivalent of bag filters for high-temperature, harsh environments. They are virtually the only alternative for high-temperature off-gas systems where a renewable, highly efficient particle trap is required. Tests were conducted which show that the sintered metal elements installed in a filter system provide effective powder collection in high-temperature atmospheres over thousands of cleaning cycles. Such a sintered metal filter system is now installed on the experimental defense waste calciner at the Savannah River Laboratory. The experimental results included in this paper were used as the basis for its design

Advanced data assimilation in strongly nonlinear dynamical systems

Science.gov (United States)

Miller, Robert N.; Ghil, Michael; Gauthiez, Francois

1994-01-01

Advanced data assimilation methods are applied to simple but highly nonlinear problems. The dynamical systems studied here are the stochastically forced double well and the Lorenz model. In both systems, linear approximation of the dynamics about the critical points near which regime transitions occur is not always sufficient to track their occurrence or nonoccurrence. Straightforward application of the extended Kalman filter yields mixed results. The ability of the extended Kalman filter to track transitions of the double-well system from one stable critical point to the other depends on the frequency and accuracy of the observations relative to the mean-square amplitude of the stochastic forcing. The ability of the filter to track the chaotic trajectories of the Lorenz model is limited to short times, as is the ability of strong-constraint variational methods. Examples are given to illustrate the difficulties involved, and qualitative explanations for these difficulties are provided. Three generalizations of the extended Kalman filter are described. The first is based on inspection of the innovation sequence, that is, the successive differences between observations and forecasts; it works very well for the double-well problem. The second, an extension to fourth-order moments, yields excellent results for the Lorenz model but will be unwieldy when applied to models with high-dimensional state spaces. A third, more practical method--based on an empirical statistical model derived from a Monte Carlo simulation--is formulated, and shown to work very well. Weak-constraint methods can be made to perform satisfactorily in the context of these simple models, but such methods do not seem to generalize easily to practical models of the atmosphere and ocean. In particular, it is shown that the equations derived in the weak variational formulation are difficult to solve conveniently for large systems.

Advanced Filtering Techniques Applied to Spaceflight, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — IST-Rolla developed two nonlinear filters for spacecraft orbit determination during the Phase I contract. The theta-D filter and the cost based filter, CBF, were...

Kalman filtering for time-delayed linear systems

Institute of Scientific and Technical Information of China (English)

LU Xiao; WANG Wei

2006-01-01

This paper is to study the linear minimum variance estimation for discrete- time systems. A simple approach to the problem is presented by developing re-organized innovation analysis for the systems with instantaneous and double time-delayed measurements. It is shown that the derived estimator involves solving three different standard Kalman filtering with the same dimension as the original system. The obtained results form the basis for solving some complicated problems such as H∞ fixed-lag smoothing, preview control, H∞ filtering and control with time delays.

Unified Digital Periodic Signal Filters for Power Converter Systems

DEFF Research Database (Denmark)

Yang, Yongheng; Xin, Zhen; Zhou, Keliang

2017-01-01

Periodic signal controllers like repetitive and resonant controllers have demonstrated much potential in the control of power electronic converters, where periodic signals (e.g., ac voltages and currents) can be precisely regulated to follow references. Beyond the control of periodic signals, ac...... signal processing (e.g., in synchronization and pre-filtering) is also very important for power converter systems. Hence, this paper serves to unify digital periodic signal filters so as to maximize their roles in power converter systems (e.g., enhance the control of ac signals). The unified digital...... periodic signal filters behave like a comb filter, but it can also be configured to selectively filter out the harmonics of interest (e.g., the odd-order harmonics in single-phase power converter systems). Moreover, a virtual variable-sampling-frequency unit delay that enables frequency adaptive periodic...

Blended particle filters for large-dimensional chaotic dynamical systems

Science.gov (United States)

Majda, Andrew J.; Qi, Di; Sapsis, Themistoklis P.

2014-01-01

A major challenge in contemporary data science is the development of statistically accurate particle filters to capture non-Gaussian features in large-dimensional chaotic dynamical systems. Blended particle filters that capture non-Gaussian features in an adaptively evolving low-dimensional subspace through particles interacting with evolving Gaussian statistics on the remaining portion of phase space are introduced here. These blended particle filters are constructed in this paper through a mathematical formalism involving conditional Gaussian mixtures combined with statistically nonlinear forecast models compatible with this structure developed recently with high skill for uncertainty quantification. Stringent test cases for filtering involving the 40-dimensional Lorenz 96 model with a 5-dimensional adaptive subspace for nonlinear blended filtering in various turbulent regimes with at least nine positive Lyapunov exponents are used here. These cases demonstrate the high skill of the blended particle filter algorithms in capturing both highly non-Gaussian dynamical features as well as crucial nonlinear statistics for accurate filtering in extreme filtering regimes with sparse infrequent high-quality observations. The formalism developed here is also useful for multiscale filtering of turbulent systems and a simple application is sketched below. PMID:24825886

IAE-adaptive Kalman filter for INS/GPS integrated navigation system

Institute of Scientific and Technical Information of China (English)

Bian Hongwei; Jin Zhihua; Tian Weifeng

2006-01-01

A marine INS/GPS adaptive navigation system is presented in this paper. GPS with two antenna providing vessel's altitude is selected as the auxiliary system fusing with INS to improve the performance of the hybrid system. The Kalman filter is the most frequently used algorithm in the integrated navigation system, which is capable of estimating INS errors online based on the measured errors between INS and GPS. The standard Kalman filter (SKF) assumes that the statistics of the noise on each sensor are given. As long as the noise distributions do not change, the Kalman filter will give the optimal estimation. However GPS receiver will be disturbed easily and thus temporally changing measurement noise will join into the outputs of GPS, which will lead to performance degradation of the Kalman filter. Many researchers introduce fuzzy logic control method into innovation-based adaptive estimation adaptive Kalman filtering (IAE-AKF) algorithm, and accordingly propose various adaptive Kalman filters. However how to design the fuzzy logic controller is a very complicated problem still without a convincing solution. A novel IAE-AKF is proposed herein, which is based on the maximum likelihood criterion for the proper computation of the filter innovation covariance and hence of the filter gain. The approach is direct and simple without having to establish fuzzy inference rules. After having deduced the proposed IAE-AKF algorithm theoretically in detail, the approach is tested by the simulation based on the system error model of the developed INS/GPS integrated marine navigation system. Simulation results show that the adaptive Kalman filter outperforms the SKF with higher accuracy, robustness and less computation. It is demonstrated that this proposed approach is a valid solution for the unknown changing measurement noise exited in the Kalman filter.

Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems.

Science.gov (United States)

Tseng, Chien-Hao; Lin, Sheng-Fuu; Jwo, Dah-Jing

2016-07-26

This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF) and fuzzy logic adaptive system (FLAS) for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system) integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF) is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD) parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF), unscented Kalman filter (UKF), and CKF approaches.

Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems

Directory of Open Access Journals (Sweden)

Chien-Hao Tseng

2016-07-01

Full Text Available This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF and fuzzy logic adaptive system (FLAS for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF, unscented Kalman filter (UKF, and CKF approaches.

A Performance Comparison Between Extended Kalman Filter and Unscented Kalman Filter in Power System Dynamic State Estimation

DEFF Research Database (Denmark)

Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

2016-01-01

Dynamic State Estimation (DSE) is a critical tool for analysis, monitoring and planning of a power system. The concept of DSE involves designing state estimation with Extended Kalman Filter (EKF) or Unscented Kalman Filter (UKF) methods, which can be used by wide area monitoring to improve......-linear state estimator is developed in MatLab to solve states by applying the unscented Kalman filter (UKF) and Extended Kalman Filter (EKF) algorithm. Finally, a DSE model is built for a 14 bus power system network to evaluate the proposed algorithm for the networks.This article will focus on comparing...

Nonlinear dynamical system identification using unscented Kalman filter

Science.gov (United States)

Rehman, M. Javvad ur; Dass, Sarat Chandra; Asirvadam, Vijanth Sagayan

2016-11-01

Kalman Filter is the most suitable choice for linear state space and Gaussian error distribution from decades. In general practical systems are not linear and Gaussian so these assumptions give inconsistent results. System Identification for nonlinear dynamical systems is a difficult task to perform. Usually, Extended Kalman Filter (EKF) is used to deal with non-linearity in which Jacobian method is used for linearizing the system dynamics, But it has been observed that in highly non-linear environment performance of EKF is poor. Unscented Kalman Filter (UKF) is proposed here as a better option because instead of analytical linearization of state space, UKF performs statistical linearization by using sigma point calculated from deterministic samples. Formation of the posterior distribution is based on the propagation of mean and covariance through sigma points.

Effectiveness of interim stage filter in the exhaust system of glove boxes

International Nuclear Information System (INIS)

Patre, D.K.; Vangara, H.; Thanamani, S.; Gopalakrishnan, R.K.; Mhatre, Amol M.

2018-01-01

All operations in radiochemical laboratories are carried out in containment systems like Glove boxes and Fume hoods. For controlling air contamination two separate air cleaning systems are incorporated. Laboratory has general ventilation system and glove boxes are provided with a negative pressure system (NPS). Glove box exhaust air is passed through three stage filtration systems: in situ, interim and final before discharging to the atmosphere. In addition to the individual HEPA filters of each glove box, there is an interim HEPA filter bank introduced at the laboratory end. This was introduced to reduce a load on main exhaust filter system. Finally the exhaust air is discharged through the final stage HEPA filter located in the filter house through the Stack. The interim HEPA filter bank provides additional protection for the release of particulate activity and reduces load on the final stage filters. In the present work efforts have been put to validate the interim stage filter, which has been introduced, to limit the environmental release

Advanced mobile satellite communications system using Ka and MM-wave bands in Japan's R and D satellite project

Science.gov (United States)

Isobe, Shunkichi; Ohmori, Shingo; Hamamoto, Naokazu; Yamamoto, Minoru

1991-01-01

Communications Research Laboratory (CRL) studied an advanced mobile satellite communications system using Ka and millimeter-wave bands in the R&D Satellite project. The project started in 1990 and the satellite will be launched in 1997. On-board multi-beam interconnecting is one of basic functions to realize one-hop connection among Very Small Aperture Terminals (VSATs), mobile, and hand-held terminals in future mobile satellite communications system. An Intermediate Frequency (IF) filter bank and regenerative transponder are suitable for this function. The transponder configuration of an advanced mobile communications mission of the R&D Satellite for experiment is shown. High power transmitters of Ka and millimeter-wave bands, a 3x3 IF filter band and Single Channel Per Carrier/Time Division Multiplexing (SCPC/TDM) regenerative MODEMS, which will be boarded on the R&D Satellite, are being developed for the purpose of studying the feasibility of advanced mobile communications system.

Adaptive digital filters

CERN Document Server

Kovačević, Branko; Milosavljević, Milan

2013-01-01

“Adaptive Digital Filters” presents an important discipline applied to the domain of speech processing. The book first makes the reader acquainted with the basic terms of filtering and adaptive filtering, before introducing the field of advanced modern algorithms, some of which are contributed by the authors themselves. Working in the field of adaptive signal processing requires the use of complex mathematical tools. The book offers a detailed presentation of the mathematical models that is clear and consistent, an approach that allows everyone with a college level of mathematics knowledge to successfully follow the mathematical derivations and descriptions of algorithms.   The algorithms are presented in flow charts, which facilitates their practical implementation. The book presents many experimental results and treats the aspects of practical application of adaptive filtering in real systems, making it a valuable resource for both undergraduate and graduate students, and for all others interested in m...

Study of Robust H∞ Filtering Application in Loosely Coupled INS/GPS System

Directory of Open Access Journals (Sweden)

Lin Zhao

2014-01-01

model, unstable model case is considered. We give an explanation for Kalman filter divergence under uncertain dynamic system and simultaneously investigate the relationship between H∞ filter and Kalman filter. A loosely coupled INS/GPS simulation system is given here to verify this application. Result shows that the robust H∞ filter has a better performance when system suffers uncertainty; also it is more robust compared to the conventional Kalman filter.

A fixed angle double mirror filter for preparing a pink undulator beam at the Advanced Photon Source

International Nuclear Information System (INIS)

Dufresne, E.; Sanchez, T.; Nurushev, T.; Clarke, R.; Dierker, S.B.

2000-01-01

Recent advances in X-ray Photon Correlation Spectroscopy (XPCS) use the full bandwidth of an undulator harmonic in order to maximize the coherent flux for small angle X-ray scattering experiments. X-ray mirrors and filters are typically used to select a given harmonic of the spectrum. At the University of Michigan/Howard University/Lucent Technologies, Bell Labs, Collaborative Access Team (MHATT-CAT) undulator beamline of the Advanced Photon Source, we have designed a fixed-angle Double Mirror Filter which will provide a 'pink beam' (i.e., 2-3% bandwidth) for XPCS experiments. This device uses two small mirrors which vertically reflect a 0.1 mmx0.1 mm white beam in a symmetric geometry. The doubly reflected beam propagates parallel to the incident white beam, but is offset vertically by 35 mm. Using the standard offset of the APS allows one to stop the white beam with a standard APS beam stop. In this report, we will describe our design considerations for this instrument. We also report the results of preliminary tests of the performance. The mirrors preserve the transverse coherence of the source, and filter the undulator spectrum as expected

Enhanced performance of a filter-sensor system.

Science.gov (United States)

Sasaki, Isao; Josowicz, Mira; Janata, Jirí; Glezer, Ari

2006-06-01

In this paper are addressed two important, but seemingly unrelated issues: long term performance of a gas sensing array and performance of an air purification unit. It is shown that when considered together, the system can be regarded as a "smart filter". The enhancement is achieved by periodic differential sampling and measurement of the "upstream" and "downstream" gases of a filter. The correctly functioning filter supplies the "zero gas" from the downstream for the continuous sensor baseline correction. A key element in this scheme is the synthetic jet that delivers well-defined pulses of the two gases. The deterioration of the performance of the "smart filter" can be diagnosed from the response pattern of the sensor. The approach has been demonstrated on removal/sensing of ammonia gas from air.

The optimal filtering of a class of dynamic multiscale systems

Institute of Scientific and Technical Information of China (English)

PAN Quan; ZHANG Lei; CUI Peiling; ZHANG Hongcai

2004-01-01

This paper discusses the optimal filtering of a class of dynamic multiscale systems (DMS), which are observed independently by several sensors distributed at different resolution spaces. The system is subject to known dynamic system model. The resolution and sampling frequencies of the sensors are supposed to decrease by a factor of two. By using the Haar wavelet transform to link the state nodes at each of the scales within a time block, a discrete-time model of this class of multiscale systems is given, and the conditions for applying Kalman filtering are proven. Based on the linear time-invariant system, the controllability and observability of the system and the stability of the Kalman filtering is studied, and a theorem is given. It is proved that the Kalman filter is stable if only the system is controllable and observable at the finest scale. Finally, a constant-velocity process is used to obtain insight into the efficiencies offered by our model and algorithm.

The second order extended Kalman filter and Markov nonlinear filter for data processing in interferometric systems

International Nuclear Information System (INIS)

Ermolaev, P; Volynsky, M

2014-01-01

Recurrent stochastic data processing algorithms using representation of interferometric signal as output of a dynamic system, which state is described by vector of parameters, in some cases are more effective, compared with conventional algorithms. Interferometric signals depend on phase nonlinearly. Consequently it is expedient to apply algorithms of nonlinear stochastic filtering, such as Kalman type filters. An application of the second order extended Kalman filter and Markov nonlinear filter that allows to minimize estimation error is described. Experimental results of signals processing are illustrated. Comparison of the algorithms is presented and discussed.

Effects of advanced treatment systems on the removal of antibiotic resistance genes in wastewater treatment plants from Hangzhou, China.

Science.gov (United States)

Chen, Hong; Zhang, Mingmei

2013-08-06

This study aimed at quantifying the concentration and removal of antibiotic resistance genes (ARGs) in three municipal wastewater treatment plants (WWTPs) employing different advanced treatment systems [biological aerated filter, constructed wetland, and ultraviolet (UV) disinfection]. The concentrations of tetM, tetO, tetQ, tetW, sulI, sulII, intI1, and 16S rDNA genes were examined in wastewater and biosolid samples. In municipal WWTPs, ARG reductions of 1-3 orders of magnitude were observed, and no difference was found among the three municipal WWTPs with different treatment processes (p > 0.05). In advanced treatment systems, 1-3 orders of magnitude of reductions in ARGs were observed in constructed wetlands, 0.6-1.2 orders of magnitude of reductions in ARGs were observed in the biological aerated filter, but no apparent decrease by UV disinfection was observed. A significant difference was found between constructed wetlands and biological filter (p removal of ARGs and 16S rDNA genes (R(2) = 0.391-0.866; p removal values with WWTP (p > 0.05) but also have the advantage in ARG relative abundance removal, and it should be given priority to be an advanced treatment system for further ARG attenuation from WWTP.

Filter aids influence on pressure drop across a filtration system

Science.gov (United States)

Hajar, S.; Rashid, M.; Nurnadia, A.; Ammar, M. R.; Hasfalina, C. M.

2017-06-01

Filter aids is commonly used to reduce pressure drop across air filtration system as it helps to increase the efficiency of filtration of accumulated filter cake. Filtration velocity is one of the main parameters that affect the performance of filter aids material. In this study, a formulated filter aids consisting of PreKot™ and activated carbon mixture (designated as PrekotAC) was tested on PTFE filter media under various filtration velocities of 5, 6, and 8 m/min at a constant material loading of 0.2 mg/mm2. Results showed that pressure drop is highly influenced by filtration velocity where higher filtration velocity leads to a higher pressure drop across the filter cake. It was found that PrekotAC performed better in terms of reducing the pressure drop across the filter cake even at the highest filtration velocity. The diversity in different particle size distribution of non-uniform particle size in the formulated PrekotAC mixture presents a higher permeability causes a lower pressure drop across the accumulated filter cake. The finding suggests that PrekotAC is a promising filter aids material that helps reducing the pressure drop across fabric filtration system.

Control and filtering for semi-Markovian jump systems

CERN Document Server

Li, Fanbiao; Wu, Ligang

2017-01-01

This book presents up-to-date research developments and novel methodologies on semi-Markovian jump systems (S-MJS). It presents solutions to a series of problems with new approaches for the control and filtering of S-MJS, including stability analysis, sliding mode control, dynamic output feedback control, robust filter design, and fault detection. A set of newly developed techniques such as piecewise analysis method, positively invariant set approach, event-triggered method, and cone complementary linearization approaches are presented. Control and Filtering for Semi-Markovian Jump Systems is a comprehensive reference for researcher and practitioners working in control engineering, system sciences and applied mathematics, and is also a useful source of information for senior undergraduates and graduates in these areas. The readers will benefit from some new concepts, new models and new methodologies with practical significance in control engineering and signal processing.

Multiple-etalon systems for the Advanced Technology Solar Telescope

Science.gov (United States)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael

2003-01-01

Multiple etalon systems are discussed that meet the science requirements for a narrow-passband imaging system for the 4-meter National Solar Observatory (NSO)/Advance Technology Solar Telescope (ATST). A multiple etalon system can provide an imaging interferometer that works in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, an intermediate-band imager, and broadband high-resolution imager. Specific dual and triple etalon configurations are described that provide a spectrographic passband of 2.0-3.5 micron and reduce parasitic light levels to 10(exp -4) as required for precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like (Telecentric Etalon SOlar Spectrometer) triple etalon system provides a spectral purity of 10(exp -5). The triple designs have the advantage of reducing the finesse requirement on each etalon; allow the use of more stable blocking filters, and have very high spectral purity. A dual-etalon double-pass (Cavallini-like) system can provide a competing configuration. Such a dual-etalon design can provide high contrast. The selection of the final focal plane instrument will depend on a trade-off between an ideal instrument and practical reality. The trade study will include the number of etalons, their aperture sizes, complexities of the optical train, number of blocking filters, configuration of the electronic control system, computer interfaces, temperature controllers, etalon controllers, and their associated feedback electronics. The heritage of single and multiple etalon systems comes from their use in several observatories, including the Marshall Space Flight Center (MSFC) Solar Observatory, Sacramento Peak Observatory (NSO), and Kiepenheuer-Institut fur Sonnenphysik (KIS, Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will benefit from the experience gained at these

Tunable Multiband Microwave Photonic Filters

Directory of Open Access Journals (Sweden)

Mable P. Fok

2017-11-01

Full Text Available The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multiband wireless communications, tunable multiband RF filters are required for channel selection, noise/interference removal, and RF signal processing. Unfortunately, it is difficult for RF electronics to achieve both tunable and multiband spectral filtering. Recent advancements of microwave photonics have proven itself to be a promising candidate to solve various challenges in RF electronics including spectral filtering, however, the development of multiband microwave photonic filtering still faces lots of difficulties, due to the limited scalability and tunability of existing microwave photonic schemes. In this review paper, we first discuss the challenges that were facing by multiband microwave photonic filter, then we review recent techniques that have been developed to tackle the challenge and lead to promising developments of tunable microwave photonic multiband filters. The successful design and implementation of tunable microwave photonic multiband filter facilitate the vision of dynamic multiband wireless communications and radio frequency signal processing for commercial, defense, and civilian applications.

Detection of arcing location on photovoltaic systems using filters

Science.gov (United States)

Johnson, Jay

2018-02-20

The present invention relates to photovoltaic systems capable of identifying the location of an arc-fault. In particular, such systems include a unique filter connected to each photovoltaic (PV) string, thereby providing a unique filtered noise profile associated with a particular PV string. Also described herein are methods for identifying and isolating such arc-faults.

TULUNGAN: A Consensus-Independent Reputation System for Collaborative Web Filtering Systems

Directory of Open Access Journals (Sweden)

Alexis V. Pantola

2011-12-01

Full Text Available Web filtering systems allow or prohibit access to websites based on categories (e.g., pornography,violence, sports, etc.. Categorization of websites can be done automatically or manually. Automaticcategorization is prone to under- and over-blocking. On the other hand, manual approach is typicallyperformed by a limited number of people making it not scalable.Collaborative web filtering systems, a variation of manual categorization, allow anyone to categorizewebsites in order to determine which domain these sites belong (e.g., pornography, violence, sports,etc.. This attempts to solve the scalability issue of the typical manual method.The approach offered by collaborative web filtering relies heavily on the contribution of users in orderto make the system scalable and less prone to errors. However, its success is greatly dependent on usercooperation. To promote cooperation, reputation system can be used in web filtering.A previous study called Rater-Rating promotes cooperation and explores the use of a user-drivenreputation system that measures both the contributor and rater reputation of users of a collaborative websystem. However, Rater-Rating is consensus dependent. If the number of malicious users are more thantheir good counterparts, the reputation system can be defeated. In other words, the system canmistakenly give malicious users a high reputation value.This study discusses a reputation system called Tulungan that is consensus-independent. It can detectthe presence of malicious users even if the number of their good counterparts are fewer. A simulationresult that compares the effectiveness of Tulungan relative to Rater-Rating is presented in this paper.The simulation shows that Tulungan is still effective even with 25% good users while Rater-Ratingrequires at least 50% good users to be effective.

A new extended H∞ filter for discrete nonlinear systems

Institute of Scientific and Technical Information of China (English)

张永安; 周荻; 段广仁

2004-01-01

Nonlinear estimation problem is investigated in this paper. By extension of a linear H∞ estimation with corrector-predictor form to nonlinear cases, a new extended H∞ filter is proposed for time-varying discretetime nonlinear systems. The new filter has a simple observer structure based on a local linearization model, and can be viewed as a general case of the extended Kalman filter (EKF). An example demonstrates that the new filter with a suitable-chosen prescribed H∞ bound performs better than the EKF.

Wiener filter applied to a neutrongraphic system

International Nuclear Information System (INIS)

Crispim, V.R.; Lopes, R.T.; Borges, J.C.

1986-01-01

The randon characteristics of the image formation process influence the spatial image obtained in a neutrongraphy. Several methods can be used to optimize this image, though estimation of the noise added to the original signal. This work deals with the optimal filtering technique, using Wiener's filter. A simulation is made, where the signal (spatial resolution function) has a Lorentz's form, and ten kinds of random noise with increasing R.M.S. are generated and individually added to the original signal. Wiener's filter is applied to different noise amplitudes and the behaviour of the spatial resolution function for our system is also analysed. (Author) [pt

In-situ continuous scanning high efficiency particulate air (HEPA) filter monitoring system

International Nuclear Information System (INIS)

Kirchner, K.N.; Johnson, C.M.; Lucerna, J.J.; Barnett, R.L.

1985-01-01

The testing and replacement of HEPA filters, which are widely used in the nuclear industry to purify process air before it is ventilated to the atmosphere, is a costly and labor-intensive undertaking. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow for determination of overall filter performance but preclude detection of symptoms of incipient filter failure, such as small holes in the filters themselves. Using current technology, a continual in-situ monitoring system has been designed which provides three major improvements over current methods of filter testing and replacement. This system (1) realizes a cost savings by reducing the number of intact filters which are currently being replaced unnecessarily, (2) provides a more accurate and quantitative measurement of filter performance than is currently achieved with existing testing methods, and (3) reduces personnel exposure to a radioactive environment by automatically performing most testing operations. The operation and performance of the HEPA filter monitoring system are discussed

Does advanced practice in radiography benefit the healthcare system? A literature review.

Science.gov (United States)

Thom, S E

2018-02-01

With ever-increasing demands on the National Health Service (NHS), members of staff are blurring their professional boundaries in the attempt to benefit the healthcare system. This review aims to establish whether advancing practice within radiography does benefit the healthcare system by examining published literature. Key words were input into databases such as: CINAHL, Science Direct and PubMed. Various filters were applied to narrow down the articles. Key themes were identified within the literature: cost, job satisfaction, patient benefits, restrictions and workload. Having advanced practitioners undertake some of the radiologists' workload was potentially cost effective whilst continuing/increasing the standard of quality. Patients benefitted from the quality of their examinations, the high accuracy of their reports and the speed those reports were attained. Evidence within the literature emphasises that advanced practice does benefit the healthcare system by means of: cost reduction, job satisfaction, patient benefits and workload. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Air filters for use at nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Linder, P [Aktiebolaget Atomenergi, Studsvik, Nykoeping (Sweden)

1970-12-01

The ventilation system of a nuclear facility plays a vital role in ensuring that the air in working areas and the environment remains free from radioactive contamination. An earlier IAEA publication, Techniques for Controlling Air Pollution from the Operation of Nuclear Facilities, Safety Series No. 17, deals with the design and operation of ventilation systems at nuclear facilities. These systems are usually provided with air-cleaning devices which remove the contaminants from the air. This publication is intended as a guide to those who are concerned with the design of air-filtering systems and with the testing, operation and maintenance of air-filter installations at nuclear facilities. Emphasis is mainly placed on so-called high-efficiency particulate air filters (HEPA filters) and on providing general information on them. Besides describing the usual filter types, their dimensions and construction materials, the guidebook attempts to explain their properties and behaviour under different operating conditions. It also gives advice on testing and handling the filters so that effective and safe performance is ensured. The guidebook should serve as an introduction to the use of high efficiency particulate air filters in countries where work with radioactive materials has only recently commenced. The list of references at the end of the book indicates sources of more advanced information for those who already have comprehensive experience in this field. It is assumed here that the filters are obtained from a manufacturer, and the guidebook thus contains no information on the design and development of the filter itself, nor does it deal with the cleaning of the intake air to a plant, with gas sorption or protective respiratory equipment.

Air filters for use at nuclear facilities

International Nuclear Information System (INIS)

Linder, P.

1970-01-01

The ventilation system of a nuclear facility plays a vital role in ensuring that the air in working areas and the environment remains free from radioactive contamination. An earlier IAEA publication, Techniques for Controlling Air Pollution from the Operation of Nuclear Facilities, Safety Series No. 17, deals with the design and operation of ventilation systems at nuclear facilities. These systems are usually provided with air-cleaning devices which remove the contaminants from the air. This publication is intended as a guide to those who are concerned with the design of air-filtering systems and with the testing, operation and maintenance of air-filter installations at nuclear facilities. Emphasis is mainly placed on so-called high-efficiency particulate air filters (HEPA filters) and on providing general information on them. Besides describing the usual filter types, their dimensions and construction materials, the guidebook attempts to explain their properties and behaviour under different operating conditions. It also gives advice on testing and handling the filters so that effective and safe performance is ensured. The guidebook should serve as an introduction to the use of high efficiency particulate air filters in countries where work with radioactive materials has only recently commenced. The list of references at the end of the book indicates sources of more advanced information for those who already have comprehensive experience in this field. It is assumed here that the filters are obtained from a manufacturer, and the guidebook thus contains no information on the design and development of the filter itself, nor does it deal with the cleaning of the intake air to a plant, with gas sorption or protective respiratory equipment

Robust filtering and fault detection of switched delay systems

CERN Document Server

Wang, Dong; Wang, Wei

2013-01-01

Switched delay systems appear in a wide field of applications including networked control systems, power systems, memristive systems. Though the large amount of ideas with respect to such systems have generated, until now, it still lacks a framework to focus on filter design and fault detection issues which are relevant to life safety and property loss. Beginning with the comprehensive coverage of the new developments in the analysis and control synthesis for switched delay systems, the monograph not only provides a systematic approach to designing the filter and detecting the fault of switched delay systems, but it also covers the model reduction issues. Specific topics covered include: (1) Arbitrary switching signal where delay-independent and delay-dependent conditions are presented by proposing a linearization technique. (2) Average dwell time where a weighted Lyapunov function is come up with dealing with filter design and fault detection issues beside taking model reduction problems. The monograph is in...

Multiple Etalon Systems for the Advanced Technology Solar Telescope

Science.gov (United States)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael; Six, N. Frank (Technical Monitor)

2002-01-01

Multiple etalons systems are discussed that meet the 4-meter NSO/Advance Technology Solar Telescope (http://www.nso.edu/ATST/index.html) instrument and science requirements for a narrow bandpass imaging system. A multiple etalon system can provide an imaging interferometer working in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, and a wide-band and broad-band high-resolution imager. Specific dual and triple etalon configurations will be described that provides spectrographic passband of 2.0-3.5nm and reduces parasitic light levels to 1/10000 as required by precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like triple etalon system provides for spectral purity of 100 thousandths. The triple designs have the advantage of reducing the finesse requirement on each etalon, allowing much more stable blocking filters, and can have very high spectral purity. A dual-etalon double-pass Cavallini-like configuration can provide a competing configuration. This design can provide high contrast with only a double etalon. The selection of the final focal plan instrument will depend on a trade-off of the ideal instrument versus reality, the number of etalons, the aperture of etalons, the number of blocking filters the electronic control system and computer interfaces, the temperature control and controllers for the etalons and the electronics. The use of existing experience should provide significant cost savings. The heritage of use of etalons and multiple etalon systems in solar physics come from a number of observatories, which includes MSFC Solar Observatory (NASA), Sac Peak Observatory (NSO), and Kiepenheuer Institute for Solar Physics (Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will reply on the existing experience from these observatories.

A novel extended Kalman filter for a class of nonlinear systems

Institute of Scientific and Technical Information of China (English)

DONG Zhe; YOU Zheng

2006-01-01

Estimation of the state variables of nonlinear systems is one of the fundamental and significant problems in control and signal processing. A new extended Kalman filtering approach for a class of nonlinear discrete-time systems in engineering is presented in this paper. In contrast to the celebrated extended Kalman filter (EKF), there is no linearization operation in the design procedure of the filter, and the parameters of the filter are obtained through minimizing a proper upper bound of the mean-square estimation error. Simulation results show that this filter can provide higher estimation precision than that provided by the EKF.

Design and evaluation of a filter-based chairside amalgam separation system

Energy Technology Data Exchange (ETDEWEB)

Stone, Mark E. [Naval Institute for Dental and Biomedical Research, 310A B Street, Great Lakes, Illinois 60088 (United States)], E-mail: mark.stone@yahoo.com; Cohen, Mark E.; Berry, Denise L.; Ragain, James C. [Naval Institute for Dental and Biomedical Research, 310A B Street, Great Lakes, Illinois 60088 (United States)

2008-06-15

This study evaluated the ability of a chairside filtration system to remove particulate-based mercury (Hg) from dental-unit wastewater. Prototypes of the chairside filtration system were designed and fabricated using reusable filter chambers with disposable filter elements. The system was installed in five dental operatories utilizing filter elements with nominal pore sizes of 50{mu}m, 15{mu}m, 1{mu}m, 0.5{mu}m, or with no system installed (control). Daily chairside wastewater samples were collected on ten consecutive days from each room and brought to the laboratory for processing. After processing the wastewater samples, Hg concentrations were determined with cold vapor atomic absorption spectrometry (USEPA method 7470A). Filter systems were exchanged after ten samples were collected so that all five of the configurations were evaluated in each room (with assignment order balanced by a Latin Square). The numbers of surfaces of amalgam placed and removed per day were tracked in each room. In part two, new filter systems with the 0.5{mu}m filter elements were installed in the five dental operatories and vacuum levels at the high-velocity evacuation cannula tip were measured with a vacuum gauge. In part three of the study, the chairside filtration system utilizing 0.5{mu}m and 15{mu}m filter elements was evaluated utilizing the ISO 11143 testing protocol, a laboratory test of amalgam separator efficiency utilizing amalgam samples of known particle size distribution. Mean Hg per chair per day (no filter installed) was 1087.38mg (SD = 993.92mg). Mean Hg per chair per day for the 50{mu}m, 15{mu}m, 1{mu}m, 0.5{mu}m filter configurations was 79.13mg (SD = 71.40mg), 23.55mg (SD = 23.25mg), 17.68mg (SD = 17.35mg), and 4.25mg (SD = 6.35mg), respectively (n = 50 for all groups). Calculated removal efficiencies from the clinical samples were 92.7%, 97.8%, 98.4%, and 99.6%, respectively. ANCOVA on data from the four filter groups, with amalgam-surfaces-removed included as a

Filter cake breaker systems

Energy Technology Data Exchange (ETDEWEB)

Garcia, Marcelo H.F. [Poland Quimica Ltda., Duque de Caxias, RJ (Brazil)

2004-07-01

Drilling fluids filter cakes are based on a combination of properly graded dispersed particles and polysaccharide polymers. High efficiency filter cakes are formed by these combination , and their formation on wellbore walls during the drilling process has, among other roles, the task of protecting the formation from instantaneous or accumulative invasion of drilling fluid filtrate, granting stability to well and production zones. Filter cake minimizes contact between drilling fluid filtrate and water, hydrocarbons and clay existent in formations. The uniform removal of the filter cake from the entire interval is a critical factor of the completion process. The main methods used to breaking filter cake are classified into two groups, external or internal, according to their removal mechanism. The aim of this work is the presentation of these mechanisms as well their efficiency. (author)

Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System

Directory of Open Access Journals (Sweden)

Jun Ho Ji

2015-01-01

Full Text Available Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2. The TiO2 nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD.

Electrically heated particulate filter regeneration methods and systems for hybrid vehicles

Science.gov (United States)

Gonze, Eugene V.; Paratore, Jr., Michael J.

2010-10-12

A control system for controlling regeneration of a particulate filter for a hybrid vehicle is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate regeneration. An engine control module controls operation of an engine of the hybrid vehicle based on the control of the current to the particulate filter.

Power system static state estimation using Kalman filter algorithm

Directory of Open Access Journals (Sweden)

Saikia Anupam

2016-01-01

Full Text Available State estimation of power system is an important tool for operation, analysis and forecasting of electric power system. In this paper, a Kalman filter algorithm is presented for static estimation of power system state variables. IEEE 14 bus system is employed to check the accuracy of this method. Newton Raphson load flow study is first carried out on our test system and a set of data from the output of load flow program is taken as measurement input. Measurement inputs are simulated by adding Gaussian noise of zero mean. The results of Kalman estimation are compared with traditional Weight Least Square (WLS method and it is observed that Kalman filter algorithm is numerically more efficient than traditional WLS method. Estimation accuracy is also tested for presence of parametric error in the system. In addition, numerical stability of Kalman filter algorithm is tested by considering inclusion of zero mean errors in the initial estimates.

Ash reduction system using electrically heated particulate matter filter

Science.gov (United States)

Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

2011-08-16

A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

Evaluation of an Advanced Harmonic Filter for Adjustable Speed Drives using a Toolbox Approach

DEFF Research Database (Denmark)

Asiminoaei, Lucian; Hansen, Steffan; Blaabjerg, Frede

2004-01-01

A large diversity of solutions exists to reduce the harmonic emission of the 6-pulse Adjustable Speed Drive in order to fulfill the requirements of the international harmonic standards. Among them, new types of advanced harmonic filters recently gained an increased attention due to their good...... a combination of a pre-stored database and new interpolation techniques the toolbox can provide the harmonic data on real applications allowing comparisons between different mitigation solutions....

Implementation of a Recommender System using Collaborative Filtering

Directory of Open Access Journals (Sweden)

Andrei-Cristian Prodan

2010-12-01

Full Text Available Nowadays, consumers have a lot of choices. Electronic retailers offer a great variety of products. Because of this, there is a need for Recommender Systems. These systems aim to solve the problem of matching consumers with the most appealing products for them. They do this by analyzing either the products information details (Content Based methods or users social behavior (Collaborative Filtering. This paper describes the Collaborative Filtering technique in more detail. It then presents one of the best methods for CF: the Matrix Factorization technique. Next, it presents two algorithms used for matrix factorization. Then, the paper describes the implementation details of a framework created by us, called Rho, that uses Collaborative Filtering. In the end, we present some results obtained after experimenting with this framework.

Kalman filter based fault diagnosis of networked control system with white noise

Institute of Scientific and Technical Information of China (English)

Yanwei WANG; Ying ZHENG

2005-01-01

The networked control system NCS is regarded as a sampled control system with output time-variant delay.White noise is considered in the model construction of NCS.By using the Kalman filter theory to compute the filter parameters,a Kalman filter is constructed for this NCS.By comparing the output of the filter and the practical system,a residual is generated to diagnose the sensor faults and the actuator faults.Finally,an example is given to show the feasibility of the approach.

Low-power implementation of polyphase filters in Quadratic Residue Number System

DEFF Research Database (Denmark)

Cardarilli, Gian Carlo; Re, Andrea Del; Nannarelli, Alberto

2004-01-01

The aim of this work is the reduction of the power dissipated in digital filters, while maintaining the timing unchanged. A polyphase filter bank in the Quadratic Residue Number System (QRNS) has been implemented and then compared, in terms of performance, area, and power dissipation...... to the implementation of a polyphase filter bank in the traditional two's complement system (TCS). The resulting implementations, designed to have the same clock rates, show that the QRNS filter is smaller and consumes less power than the TCS one....

Advanced Mud System for Microhole Coiled Tubing Drilling

Energy Technology Data Exchange (ETDEWEB)

Kenneth Oglesby

2008-12-01

An advanced mud system was designed and key components were built that augment a coiled tubing drilling (CTD) rig that is designed specifically to drill microholes (less than 4-inch diameter) with advanced drilling techniques. The mud system was tailored to the hydraulics of the hole geometries and rig characteristics required for microholes and is capable of mixing and circulating mud and removing solids while being self contained and having zero discharge capability. Key components of this system are two modified triplex mud pumps (High Pressure Slurry Pumps) for advanced Abrasive Slurry Jetting (ASJ) and a modified Gas-Liquid-Solid (GLS) Separator for well control, flow return and initial processing. The system developed also includes an additional component of an advanced version of ASJ which allows cutting through most all materials encountered in oil and gas wells including steel, cement, and all rock types. It includes new fluids and new ASJ nozzles. The jetting mechanism does not require rotation of the bottom hole assembly or drill string, which is essential for use with Coiled Tubing (CT). It also has low reactive forces acting on the CT and generates cuttings small enough to be easily cleaned from the well bore, which is important in horizontal drilling. These cutting and mud processing components and capabilities compliment the concepts put forth by DOE for microhole coiled tubing drilling (MHTCTD) and should help insure the reality of drilling small diameter holes quickly and inexpensively with a minimal environmental footprint and that is efficient, compact and portable. Other components (site liners, sump and transfer pumps, stacked shakers, filter membranes, etc.. ) of the overall mud system were identified as readily available in industry and will not be purchased until we are ready to drill a specific well.

An Oversampled Filter Bank Multicarrier System for cognitive Radio

NARCIS (Netherlands)

Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria; Zhang, Q; Zhang, Q.

2008-01-01

Due to small sideband power leakage, filter bank multicarrier techniques are considered as interesting alternatives to traditional OFDMs for spectrum pooling Cognitive Radio. In this paper, we propose an oversampled filter bank multicarrier system for Cognitive Radio. The increased spacing between

Fault diagnosis system of electromagnetic valve using neural network filter

International Nuclear Information System (INIS)

Hayashi, Shoji; Odaka, Tomohiro; Kuroiwa, Jousuke; Ogura, Hisakazu

2008-01-01

This paper is concerned with the gas leakage fault detection of electromagnetic valve using a neural network filter. In modern plants, the ability to detect and identify gas leakage faults is becoming increasingly important. The main difficulty in detecting gas leakage faults by sound signals lies in the fact that the practical plants are usually very noisy. To solve this difficulty, a neural network filter is used to eliminate background noise and raise the signal noise ratio of the sound signal. The background noise is assumed as a dynamic system, and an accurate mathematical model of the dynamic system can be established using a neural network filter. The predicted error between predicted values and practical ones constitutes the output of the filter. If the predicted error is zero, then there is no leakage. If the predicted error is greater than a certain value, then there is a leakage fault. Through application to practical pneumatic systems, it is verified that the neural network filter was effective in gas leakage detection. (author)

H∞ Filtering for Networked Markovian Jump Systems with Multiple Stochastic Communication Delays

Directory of Open Access Journals (Sweden)

Hui Dong

2015-01-01

Full Text Available This paper is concerned with the H∞ filtering for a class of networked Markovian jump systems with multiple communication delays. Due to the existence of communication constraints, the measurement signal cannot arrive at the filter completely on time, and the stochastic communication delays are considered in the filter design. Firstly, a set of stochastic variables is introduced to model the occurrence probabilities of the delays. Then based on the stochastic system approach, a sufficient condition is obtained such that the filtering error system is stable in the mean-square sense and with a prescribed H∞ disturbance attenuation level. The optimal filter gain parameters can be determined by solving a convex optimization problem. Finally, a simulation example is given to show the effectiveness of the proposed filter design method.

A paired wedge filter system for compensation in dose differences

International Nuclear Information System (INIS)

Kobayashi, H.; Sakurai, Y.; Kondo, S.; Abe, S.; Hayakawa, N.; Aoyama, Y.; Obata, Y.; Ishigaki, T.

1998-01-01

Objective: In radiotherapy, it is important to conform the high dose volume to the planned target volume. A variable thickness paired wedge filter system was developed to compensate for dose inhomogeneity arising from field width segment variation in conformal irradiation. Materials and methods: The present study used a 6 MV linear accelerator equipped with multileaf collimator leaves and a paired wedge compensating filter system. The dose variation due to field width was measured in each field segment width. The variation in attenuation of the compensators was measured as a function of filter position. As the field width increases, the relative absorbed dose also increases; this is the point of requiring compensation, so it can be in reverse proportion. Results: As the field width increases, the relative absorbed dose also increases; this is why compensation is required and thus it must be in reverse proportion. Attenuation of the absorbed dose by the paired filters was in proportion to the filter position. The filter position to compensate for the difference of absorbed doses was defined by the square root of the field width. For a field varying in width from 4 to 16 cm, the variation in the absorbed dose across the field was reduced from 12% to 2.7%. Conclusion: This paired wedge filter system reduced absorbed dose variations across multileaf collimator shaped fields and can facilitate treatment planning in conformal therapy. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

40 CFR 141.560 - Is my system subject to individual filter turbidity requirements?

Science.gov (United States)

2010-07-01

... filter turbidity requirements? 141.560 Section 141.560 Protection of Environment ENVIRONMENTAL PROTECTION... Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.560 Is my system subject to individual filter turbidity requirements? If your system is a subpart...

Sensor failure detection in dynamical systems by Kalman filtering methodology

International Nuclear Information System (INIS)

Ciftcioglu, O.

1991-03-01

Design of a sensor failure detection system by Kalman filtering methodology is described. The method models the process systems in state-space form, the information on each state being provided by relevant sensors present in the process system. Since the measured states are usually subject to noise, the estimation of the states optimally is an essential requirement. To this end the detection system comprises Kalman estimation filters, the number of which is equal to the number of states concerned. The estimated state of a particular signal in each filter is compared with the corresponding measured signal and difference beyond a predetermined bound is identified as failure, the sensor being identified/isolated as faulty. (author). 19 refs.; 8 figs.; 1 tab

Digital Simulation of a Hybrid Active Filter - An Active Filter in Series with a Shunt Passive Filter

OpenAIRE

Sitaram, Mahesh I; Padiyar, KR; Ramanarayanan, V

1998-01-01

Active filters have long been in use for the filtering of power system load harmonics. In this paper, the digital simulation results of a hybrid active power filter system for a rectifier load are presented. The active filter is used for filtering higher order harmonics as the dominant harmonics are filtered by the passive filter. This reduces the rating of the active filter significantly. The DC capacitor voltage of the active filter is controlled using a PI controller.

Filtering and control of stochastic jump hybrid systems

CERN Document Server

Yao, Xiuming; Zheng, Wei Xing

2016-01-01

This book presents recent research work on stochastic jump hybrid systems. Specifically, the considered stochastic jump hybrid systems include Markovian jump Ito stochastic systems, Markovian jump linear-parameter-varying (LPV) systems, Markovian jump singular systems, Markovian jump two-dimensional (2-D) systems, and Markovian jump repeated scalar nonlinear systems. Some sufficient conditions are first established respectively for the stability and performances of those kinds of stochastic jump hybrid systems in terms of solution of linear matrix inequalities (LMIs). Based on the derived analysis conditions, the filtering and control problems are addressed. The book presents up-to-date research developments and novel methodologies on stochastic jump hybrid systems. The contents can be divided into two parts: the first part is focused on robust filter design problem, while the second part is put the emphasis on robust control problem. These methodologies provide a framework for stability and performance analy...

Study on vent containment filtering for the Spanish NPPS systems

International Nuclear Information System (INIS)

Peinado, A.; Serrano, C.; Garcia-Serrano, J. L.

2013-01-01

The study discusses filtering systems on the market, and its suppliers, taking into account aspects such as ease of integration into the current plant design, characteristics of the process of filtering, operational range, autonomy of the system, maintenance, qualification and proven experiences, among others. The study, also contains an analysis of sequences kind of accident that serve to define the design parameters of the system.

Efficient decoding with steady-state Kalman filter in neural interface systems.

Science.gov (United States)

Malik, Wasim Q; Truccolo, Wilson; Brown, Emery N; Hochberg, Leigh R

2011-02-01

The Kalman filter is commonly used in neural interface systems to decode neural activity and estimate the desired movement kinematics. We analyze a low-complexity Kalman filter implementation in which the filter gain is approximated by its steady-state form, computed offline before real-time decoding commences. We evaluate its performance using human motor cortical spike train data obtained from an intracortical recording array as part of an ongoing pilot clinical trial. We demonstrate that the standard Kalman filter gain converges to within 95% of the steady-state filter gain in 1.5±0.5 s (mean ±s.d.). The difference in the intended movement velocity decoded by the two filters vanishes within 5 s, with a correlation coefficient of 0.99 between the two decoded velocities over the session length. We also find that the steady-state Kalman filter reduces the computational load (algorithm execution time) for decoding the firing rates of 25±3 single units by a factor of 7.0±0.9. We expect that the gain in computational efficiency will be much higher in systems with larger neural ensembles. The steady-state filter can thus provide substantial runtime efficiency at little cost in terms of estimation accuracy. This far more efficient neural decoding approach will facilitate the practical implementation of future large-dimensional, multisignal neural interface systems.

Applications of adaptive filters in active noise control

Science.gov (United States)

Darlington, Paul

The active reduction of acoustic noise is achieved by the addition of a cancelling acoustic signal to the unwanted sound. Successful definition of the cancelling signal amounts to a system identification problem. Recent advances in adaptive signal processing have allowed this problem to be tackled using adaptive filters, which offer significant advantages over conventional solutions. The extension of adaptive noise cancelling techniques, which were developed in the electrical signal conditioning context, to the control of acoustic systems is studied. An analysis is presented of the behavior of the Widrow-Hoff LMS adaptive noise canceller with a linear filter in its control loop. The active control of plane waves propagating axially in a hardwalled duct is used as a motivating model problem. The model problem also motivates the study of the effects of feedback around an LMS adaptive filter. An alternative stochastic gradient algorithm for controlling adaptive filters in the presence of feedback is presented.

High-Performance Monitoring Architecture for Large-Scale Distributed Systems Using Event Filtering

Science.gov (United States)

Maly, K.

1998-01-01

Monitoring is an essential process to observe and improve the reliability and the performance of large-scale distributed (LSD) systems. In an LSD environment, a large number of events is generated by the system components during its execution or interaction with external objects (e.g. users or processes). Monitoring such events is necessary for observing the run-time behavior of LSD systems and providing status information required for debugging, tuning and managing such applications. However, correlated events are generated concurrently and could be distributed in various locations in the applications environment which complicates the management decisions process and thereby makes monitoring LSD systems an intricate task. We propose a scalable high-performance monitoring architecture for LSD systems to detect and classify interesting local and global events and disseminate the monitoring information to the corresponding end- points management applications such as debugging and reactive control tools to improve the application performance and reliability. A large volume of events may be generated due to the extensive demands of the monitoring applications and the high interaction of LSD systems. The monitoring architecture employs a high-performance event filtering mechanism to efficiently process the large volume of event traffic generated by LSD systems and minimize the intrusiveness of the monitoring process by reducing the event traffic flow in the system and distributing the monitoring computation. Our architecture also supports dynamic and flexible reconfiguration of the monitoring mechanism via its Instrumentation and subscription components. As a case study, we show how our monitoring architecture can be utilized to improve the reliability and the performance of the Interactive Remote Instruction (IRI) system which is a large-scale distributed system for collaborative distance learning. The filtering mechanism represents an Intrinsic component integrated

Correction of Bowtie-Filter Normalization and Crescent Artifacts for a Clinical CBCT System.

Science.gov (United States)

Zhang, Hong; Kong, Vic; Huang, Ke; Jin, Jian-Yue

2017-02-01

To present our experiences in understanding and minimizing bowtie-filter crescent artifacts and bowtie-filter normalization artifacts in a clinical cone beam computed tomography system. Bowtie-filter position and profile variations during gantry rotation were studied. Two previously proposed strategies (A and B) were applied to the clinical cone beam computed tomography system to correct bowtie-filter crescent artifacts. Physical calibration and analytical approaches were used to minimize the norm phantom misalignment and to correct for bowtie-filter normalization artifacts. A combined procedure to reduce bowtie-filter crescent artifacts and bowtie-filter normalization artifacts was proposed and tested on a norm phantom, CatPhan, and a patient and evaluated using standard deviation of Hounsfield unit along a sampling line. The bowtie-filter exhibited not only a translational shift but also an amplitude variation in its projection profile during gantry rotation. Strategy B was better than strategy A slightly in minimizing bowtie-filter crescent artifacts, possibly because it corrected the amplitude variation, suggesting that the amplitude variation plays a role in bowtie-filter crescent artifacts. The physical calibration largely reduced the misalignment-induced bowtie-filter normalization artifacts, and the analytical approach further reduced bowtie-filter normalization artifacts. The combined procedure minimized both bowtie-filter crescent artifacts and bowtie-filter normalization artifacts, with Hounsfield unit standard deviation being 63.2, 45.0, 35.0, and 18.8 Hounsfield unit for the best correction approaches of none, bowtie-filter crescent artifacts, bowtie-filter normalization artifacts, and bowtie-filter normalization artifacts + bowtie-filter crescent artifacts, respectively. The combined procedure also demonstrated reduction of bowtie-filter crescent artifacts and bowtie-filter normalization artifacts in a CatPhan and a patient. We have developed a step

Robust output feedback H-infinity control and filtering for uncertain linear systems

CERN Document Server

Chang, Xiao-Heng

2014-01-01

"Robust Output Feedback H-infinity Control and Filtering for Uncertain Linear Systems" discusses new and meaningful findings on robust output feedback H-infinity control and filtering for uncertain linear systems, presenting a number of useful and less conservative design results based on the linear matrix inequality (LMI) technique. Though primarily intended for graduate students in control and filtering, the book can also serve as a valuable reference work for researchers wishing to explore the area of robust H-infinity control and filtering of uncertain systems. Dr. Xiao-Heng Chang is a Professor at the College of Engineering, Bohai University, China.

Using Kalman Filters to Reduce Noise from RFID Location System

Science.gov (United States)

Xavier, José; Reis, Luís Paulo; Petry, Marcelo

2014-01-01

Nowadays, there are many technologies that support location systems involving intrusive and nonintrusive equipment and also varying in terms of precision, range, and cost. However, the developers some time neglect the noise introduced by these systems, which prevents these systems from reaching their full potential. Focused on this problem, in this research work a comparison study between three different filters was performed in order to reduce the noise introduced by a location system based on RFID UWB technology with an associated error of approximately 18 cm. To achieve this goal, a set of experiments was devised and executed using a miniature train moving at constant velocity in a scenario with two distinct shapes—linear and oval. Also, this train was equipped with a varying number of active tags. The obtained results proved that the Kalman Filter achieved better results when compared to the other two filters. Also, this filter increases the performance of the location system by 15% and 12% for the linear and oval paths respectively, when using one tag. For a multiple tags and oval shape similar results were obtained (11–13% of improvement). PMID:24592186

Evaluation of advanced containment features proposed to Korean SNPP

International Nuclear Information System (INIS)

Jin, Y.; Park, S.Y.; Kim, S.D.; Kim, D.H.

1997-01-01

Korean Standard Nuclear Power Plant (KSNP) has adopted many advanced design features to enhance its containment performance during severe accidents as well as to reduce changes of core damage. Robust design of containment and hydrogen mixing capability reduced containment failure probability significantly. In addition to these features, new systems are proposed for KSNP: advanced design of cavity geometry, reactor cavity flooding system, hydrogen igniter, and containment filtered venting system. Before these proposals are adopted to the KSNP, their effectiveness on containment performance has been assessed systematically. Containment event tree and sensitivity analysis are used to quantify the effectiveness of these design features. The overall results indicate that these new features do not improve the containment performance significantly except the containment filtered venting system. But adoption of the containment filtered venting system should be examined carefully because accidental failure of this system may result in undue risk to public. (author)

Kalman filtering applied to a reagent feed system

International Nuclear Information System (INIS)

Griffin, C.D.; Croson, D.V.; Feeley, J.J.

1988-01-01

Using a Kalman filter solves a troublesome measurement noise problem and, at the same time, improves nuclear safety by detecting leaks to the process' feed tanks. To demonstrate how this technology of optimal estimation can be exploited, this article presents a systematic plan and example of how a Kalman filter was proven in industrial use on a reagent analyzer. A process to recycle uranium from spent fuel elements uses a reagent stream containing boron to dissolve the fuel. The boron is the neutron poison that prevents a nuclear chain reaction during the uranium dissolution. The purpose of the Kalman filter for this system is to reduce the uncertainty in the boron concentration measurement. The filter also provides incipient fault detection by estimating the unmeasured state of any unpoisoned solution, which would dilute the boron solution, entering the feed vessel

View Synthesis for Advanced 3D Video Systems

Directory of Open Access Journals (Sweden)

2009-02-01

Full Text Available Interest in 3D video applications and systems is growing rapidly and technology is maturating. It is expected that multiview autostereoscopic displays will play an important role in home user environments, since they support multiuser 3D sensation and motion parallax impression. The tremendous data rate cannot be handled efficiently by representation and coding formats such as MVC or MPEG-C Part 3. Multiview video plus depth (MVD is a new format that efficiently supports such advanced 3DV systems, but this requires high-quality intermediate view synthesis. For this, a new approach is presented that separates unreliable image regions along depth discontinuities from reliable image regions, which are treated separately and fused to the final interpolated view. In contrast to previous layered approaches, our algorithm uses two boundary layers and one reliable layer, performs image-based 3D warping only, and was generically implemented, that is, does not necessarily rely on 3D graphics support. Furthermore, different hole-filling and filtering methods are added to provide high-quality intermediate views. As a result, high-quality intermediate views for an existing 9-view auto-stereoscopic display as well as other stereo- and multiscopic displays are presented, which prove the suitability of our approach for advanced 3DV systems.

View Synthesis for Advanced 3D Video Systems

Directory of Open Access Journals (Sweden)

Müller Karsten

2008-01-01

Full Text Available Abstract Interest in 3D video applications and systems is growing rapidly and technology is maturating. It is expected that multiview autostereoscopic displays will play an important role in home user environments, since they support multiuser 3D sensation and motion parallax impression. The tremendous data rate cannot be handled efficiently by representation and coding formats such as MVC or MPEG-C Part 3. Multiview video plus depth (MVD is a new format that efficiently supports such advanced 3DV systems, but this requires high-quality intermediate view synthesis. For this, a new approach is presented that separates unreliable image regions along depth discontinuities from reliable image regions, which are treated separately and fused to the final interpolated view. In contrast to previous layered approaches, our algorithm uses two boundary layers and one reliable layer, performs image-based 3D warping only, and was generically implemented, that is, does not necessarily rely on 3D graphics support. Furthermore, different hole-filling and filtering methods are added to provide high-quality intermediate views. As a result, high-quality intermediate views for an existing 9-view auto-stereoscopic display as well as other stereo- and multiscopic displays are presented, which prove the suitability of our approach for advanced 3DV systems.

Linear filtering of systems with memory and application to finance

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available We study the linear filtering problem for systems driven by continuous Gaussian processes V ( 1 and V ( 2 with memory described by two parameters. The processes V ( j have the virtue that they possess stationary increments and simple semimartingale representations simultaneously. They allow for straightforward parameter estimations. After giving the semimartingale representations of V ( j by innovation theory, we derive Kalman-Bucy-type filtering equations for the systems. We apply the result to the optimal portfolio problem for an investor with partial observations. We illustrate the tractability of the filtering algorithm by numerical implementations.

An improved fuzzy Kalman filter for state estimation of nonlinear systems

International Nuclear Information System (INIS)

Zhou, Z-J; Hu, C-H; Chen, L; Zhang, B-C

2008-01-01

The extended fuzzy Kalman filter (EFKF) is developed recently and used for state estimation of the nonlinear systems with uncertainty. Based on extension of the orthogonality principle and the extended fuzzy Kalman filter, an improved fuzzy Kalman filters (IFKF) is proposed in this paper, which is more applicable and can deal with the state estimation of the nonlinear systems better than the EFKF. A simulation study is provided to verify the efficiency of the proposed method

High performance 3D adaptive filtering for DSP based portable medical imaging systems

Science.gov (United States)

Bockenbach, Olivier; Ali, Murtaza; Wainwright, Ian; Nadeski, Mark

2015-03-01

Portable medical imaging devices have proven valuable for emergency medical services both in the field and hospital environments and are becoming more prevalent in clinical settings where the use of larger imaging machines is impractical. Despite their constraints on power, size and cost, portable imaging devices must still deliver high quality images. 3D adaptive filtering is one of the most advanced techniques aimed at noise reduction and feature enhancement, but is computationally very demanding and hence often cannot be run with sufficient performance on a portable platform. In recent years, advanced multicore digital signal processors (DSP) have been developed that attain high processing performance while maintaining low levels of power dissipation. These processors enable the implementation of complex algorithms on a portable platform. In this study, the performance of a 3D adaptive filtering algorithm on a DSP is investigated. The performance is assessed by filtering a volume of size 512x256x128 voxels sampled at a pace of 10 MVoxels/sec with an Ultrasound 3D probe. Relative performance and power is addressed between a reference PC (Quad Core CPU) and a TMS320C6678 DSP from Texas Instruments.

Exploitation of Digital Filters to Advance the Single-Phase T/4 Delay PLL System

DEFF Research Database (Denmark)

Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

2016-01-01

will violate this design rule and it can become a major challenge for digital controllers. To deal with the above issue, this paper first exploits a virtual unit delay (z_v^-1) to emulate the viable sampling behavior in practical digital signal processors with a fixed sampling rate. This exploitation......With the development of digital signal processing technologies, control and monitoring of power electronics conversion systems have been evolving to become fully digital. As the basic element in the design and analysis phase of digital controllers or filters, a number of unit delays (z^-1) have...... been employed, e.g., in a cascaded structure. Practically, the number of unit delays is designed as an integer, which is related to the sampling frequency (e.g., 50 Hz). More common, the sampling frequency is fixed during operation for simplicity and design. Hence, any disturbance in the ac signal...

Development of an Advanced Recycle Filter Tank Assembly for the ISS Urine Processor Assembly

Science.gov (United States)

Link, Dwight E., Jr.; Carter, Donald Layne; Higbie, Scott

2010-01-01

Recovering water from urine is a process that is critical to supporting larger crews for extended missions aboard the International Space Station. Urine is collected, preserved, and stored for processing into water and a concentrated brine solution that is highly toxic and must be contained to avoid exposure to the crew. The brine solution is collected in an accumulator tank, called a Recycle Filter Tank Assembly (RFTA) that must be replaced monthly and disposed in order to continue urine processing operations. In order to reduce resupply requirements, a new accumulator tank is being developed that can be emptied on orbit into existing ISS waste tanks. The new tank, called the Advanced Recycle Filter Tank Assembly (ARFTA) is a metal bellows tank that is designed to collect concentrated brine solution and empty by applying pressure to the bellows. This paper discusses the requirements and design of the ARFTA as well as integration into the urine processor assembly.

A Study of Parallel Operation of an active Filter and passive Filters

DEFF Research Database (Denmark)

Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

2002-01-01

This paper reports investigations of the parallel operations of a current controlled active filter and passive filters in a system with current harmonic sources. The task of reactive power and harmonic compensation is shared by the active filter and passive filters. The passive filters are used...... arrangements of the active and passive filters can operate relatively independently, also the compensation flexibility of the active filter can be fully exploited, such as one active filter for several harmonic sources.The simulation studies on various systems have been performed to evaluate the effectiveness...... of the systems. The results show that the power factor is corrected by the passive filters, harmonics are minimized by both active and passive filters and overloading of the filter system can be avoided....

Quantum demolition filtering and optimal control of unstable systems.

Science.gov (United States)

Belavkin, V P

2012-11-28

A brief account of the quantum information dynamics and dynamical programming methods for optimal control of quantum unstable systems is given to both open loop and feedback control schemes corresponding respectively to deterministic and stochastic semi-Markov dynamics of stable or unstable systems. For the quantum feedback control scheme, we exploit the separation theorem of filtering and control aspects as in the usual case of quantum stable systems with non-demolition observation. This allows us to start with the Belavkin quantum filtering equation generalized to demolition observations and derive the generalized Hamilton-Jacobi-Bellman equation using standard arguments of classical control theory. This is equivalent to a Hamilton-Jacobi equation with an extra linear dissipative term if the control is restricted to Hamiltonian terms in the filtering equation. An unstable controlled qubit is considered as an example throughout the development of the formalism. Finally, we discuss optimum observation strategies to obtain a pure quantum qubit state from a mixed one.

Evaluation Of Spatial Filters For Background Suppression In Infrared Mosaic Sensor Systems

Science.gov (United States)

Bergen, T. L.; Mazaika, P. K.

1982-12-01

Spaceborne infrared mosaic sensors have been proposed for future surveillance systems. Because these systems will generate a large volume of data, background suppression will require algorithms which use innovative architectures and minimal storage. This paper analyzes the implementation and performance of candidate temporal and spatial filters. Spatial filters are attractive because they require far less memory, can effectively exploit a parallel, pipelined architecture, and are relatively insensitive to target speed. However, the performance of spatial filtering is substantially worse than that of temporal filtering when the sensor has good line-of-sight stability.

Westinghouse containment filtered venting system wet scrubber technology

International Nuclear Information System (INIS)

Kristensson, S.; Nilsson, P-O.

2014-01-01

Following the Fukushima event Westinghouse has further developed and enhanced its filtered containment venting system (FCVS) product line. The filtration efficiency of the proven FILTRA-MVSS system installed at all Swedish NPPs as well as at the Muhelberg plant in Switzerland has been enhanced and a new wet scrubber design, SVEN (Safety Venting), based on the FILTRA-MVSS tradition, developed. To meet increased filtration requirements for organic iodine these two wet scrubber products have been complemented with a zeolite module. The offering of a select choice of products allows for a better adjustment to the specific constraints and needs of each nuclear power station that is planning for the installation of such a system. The FILTRA-MVSS (MVSS=Multi Venturi Scrubber System) is a wet containment filtered vent system that uses multiple venturies to create an interaction between the vent gases and the scrubber media allowing for removal of aerosols and gaseous iodines in a very efficient manner. The FILTRA-MVSS was originally developed to meet stringent requirements on autonomy and maintained filtration efficiency over a wide range of venting conditions. The system was jointly developed in the late 80's by ABB Atom and ABB Flaekt, today Westinghouse and Alstom. Following installations in Sweden and Switzerland the system was further developed by replacement of the gravel-bed moisture separator with a standard demister and by addition of a set of sintered metal fibre filter cartridges placed after the moisture separator step. The system is today offered as a modular steel tank design to simplify installation at site. To reduce complexity and delivery time Westinghouse has developed an alternative design in which the venturi module is replaced by a submerged metal fibre filter cartridges module. This new wet scrubber design, SVEN (patent pending), provides a flexible, compact, and lower weight system, while still preserving and even enhancing the filtration

Performance evaluation of nuclear grade filters for the Trupact-I pressure equalization system

International Nuclear Information System (INIS)

Sandoval, R.P.; Joseph, B.J.

1987-01-01

The performance of high-efficiency-particulate-air and ultra-low- penetration-air filters subjected to extreme environments of temperature, shock, pressure, and particulate loading was evaluated in a test program at the Sandia National Laboratories. The test program was initiated to evaluate the feasibility of using commercially available nuclear-grade filters in the filtered pressure equalization system of a contact-handled transuranic waste transport system, called TRUPACT-I. The filtered pressure equalization system of TRUPACT-I assures containment of the activity within the limits permitted by federal regulations and simultaneously equalizes the pressure between the cavity of the packaging and the environment, and minimizes the buildup of radiolytically generated gases. The filters were exposed to temperatures, pressures and stresses that exceed expected environments in normal and accident conditions of transport. The performance of the test filters was determined by measuring and quantifying filter efficiency and the Darcy constant. In addition, the integrity of the filter housing was evaluated using non-destructive helium leak testing. The details of the test program and results obtained from the tests are presented in this paper

Method for cleaning the filter pockets of dust gas filter systems

Energy Technology Data Exchange (ETDEWEB)

Margraf, A

1975-05-07

The invention deals with a method to clean filter pockets filled with dust gas. By a periodic to and fro air jet attached to a scavenging blower, a pulsed fluttering movement of the filter surface is obtained which releases the outer layers of dust. The charging of the filter pockets with scavenging air to clean the filter material can be carried out immediately on the pulsed admission with suitable time control.

Advances in Collaborative Filtering

Science.gov (United States)

Koren, Yehuda; Bell, Robert

The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

Conservation of filtering in manufacturing systems with unreliable machines and finished goods buffers

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available This paper addresses the issue of reliable satisfaction of customer demand by unreliable production systems. In the framework of a simple production-storage-customer model, we show that this can be accomplished by using an appropriate level of filtering of production randomness. The filtering is ensured by finished goods buffers (filtering in space and shipping periods (filtering in time. The following question is considered: how are filtering in space and filtering in time interrelated? As an answer, we show that there exists a conservation law: in lean manufacturing systems, the amount of filtering in space multiplied by the amount of filteringin time (both measured in appropriate dimensionless units ispractically constant. Along with providing an insight into the nature of manufacturing systems, this law offers a tool for selecting the smallest, that is, lean, finished goods buffering, which is necessary and sufficient to ensure the desired level ofcustomer demand satisfaction.

Time-dependent switched discrete-time linear systems control and filtering

CERN Document Server

Zhang, Lixian; Shi, Peng; Lu, Qiugang

2016-01-01

This book focuses on the basic control and filtering synthesis problems for discrete-time switched linear systems under time-dependent switching signals. Chapter 1, as an introduction of the book, gives the backgrounds and motivations of switched systems, the definitions of the typical time-dependent switching signals, the differences and links to other types of systems with hybrid characteristics and a literature review mainly on the control and filtering for the underlying systems. By summarizing the multiple Lyapunov-like functions (MLFs) approach in which different requirements on comparisons of Lyapunov function values at switching instants, a series of methodologies are developed for the issues on stability and stabilization, and l2-gain performance or tube-based robustness for l∞ disturbance, respectively, in Chapters 2 and 3. Chapters 4 and 5 are devoted to the control and filtering problems for the time-dependent switched linear systems with either polytopic uncertainties or measurable time-varying...

ROBUST KALMAN FILTERING FOR SYSTEMS UNDER NORM BOUNDED UNCERTAINTIES IN ALL SYSTEM MATRICES AND ERROR COVARIANCE CONSTRAINTS

Institute of Scientific and Technical Information of China (English)

XIA Yuanqing; HAN Jingqing

2005-01-01

This paper concerns robust Kalman filtering for systems under norm bounded uncertainties in all the system matrices and error covariance constraints. Sufficient conditions are given for the existence of such filters in terms of Riccati equations. The solutions to the conditions can be used to design the filters. Finally, an illustrative example is given to demonstrate the effectiveness of the proposed design procedure.

UWB Bandpass Filter with Ultra-wide Stopband based on Ring Resonator

Science.gov (United States)

Kazemi, Maryam; Lotfi, Saeedeh; Siahkamari, Hesam; Mohammadpanah, Mahmood

2018-04-01

An ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.

Cost-Effective Video Filtering Solution for Real-Time Vision Systems

Directory of Open Access Journals (Sweden)

Karl Martin

2005-08-01

Full Text Available This paper presents an efficient video filtering scheme and its implementation in a field-programmable logic device (FPLD. Since the proposed nonlinear, spatiotemporal filtering scheme is based on order statistics, its efficient implementation benefits from a bit-serial realization. The utilization of both the spatial and temporal correlation characteristics of the processed video significantly increases the computational demands on this solution, and thus, implementation becomes a significant challenge. Simulation studies reported in this paper indicate that the proposed pipelined bit-serial FPLD filtering solution can achieve speeds of up to 97.6 Mpixels/s and consumes 1700 to 2700 logic cells for the speed-optimized and area-optimized versions, respectively. Thus, the filter area represents only 6.6 to 10.5% of the Altera STRATIX EP1S25 device available on the Altera Stratix DSP evaluation board, which has been used to implement a prototype of the entire real-time vision system. As such, the proposed adaptive video filtering scheme is both practical and attractive for real-time machine vision and surveillance systems as well as conventional video and multimedia applications.

A variational Bayesian multiple particle filtering scheme for large-dimensional systems

KAUST Repository

Ait-El-Fquih, Boujemaa

2016-06-14

This paper considers the Bayesian filtering problem in high-dimensional nonlinear state-space systems. In such systems, classical particle filters (PFs) are impractical due to the prohibitive number of required particles to obtain reasonable performances. One approach that has been introduced to overcome this problem is the concept of multiple PFs (MPFs), where the state-space is split into low-dimensional subspaces and then a separate PF is applied to each subspace. Remarkable performances of MPF-like filters motivated our investigation here into a new strategy that combines the variational Bayesian approach to split the state-space with random sampling techniques, to derive a new computationally efficient MPF. The propagation of each particle in the prediction step of the resulting filter requires generating only a single particle in contrast with standard MPFs, for which a set of (children) particles is required. We present simulation results to evaluate the behavior of the proposed filter and compare its performances against standard PF and a MPF.

A variational Bayesian multiple particle filtering scheme for large-dimensional systems

KAUST Repository

Ait-El-Fquih, Boujemaa; Hoteit, Ibrahim

2016-01-01

This paper considers the Bayesian filtering problem in high-dimensional nonlinear state-space systems. In such systems, classical particle filters (PFs) are impractical due to the prohibitive number of required particles to obtain reasonable performances. One approach that has been introduced to overcome this problem is the concept of multiple PFs (MPFs), where the state-space is split into low-dimensional subspaces and then a separate PF is applied to each subspace. Remarkable performances of MPF-like filters motivated our investigation here into a new strategy that combines the variational Bayesian approach to split the state-space with random sampling techniques, to derive a new computationally efficient MPF. The propagation of each particle in the prediction step of the resulting filter requires generating only a single particle in contrast with standard MPFs, for which a set of (children) particles is required. We present simulation results to evaluate the behavior of the proposed filter and compare its performances against standard PF and a MPF.

Identification of chaotic memristor systems based on piecewise adaptive Legendre filters

International Nuclear Information System (INIS)

Zhao, Yibo; Zhang, Xiuzai; Xu, Jin; Guo, Yecai

2015-01-01

Memristor is a nonlinear device, which plays an important role in the design and implementation of chaotic systems. In order to be able to understand in-depth the complex nonlinear dynamic behaviors in chaotic memristor systems, modeling or identification of its nonlinear model is very important premise. This paper presents a chaotic memristor system identification method based on piecewise adaptive Legendre filters. The threshold decomposition is carried out for the input vector, and also the input signal subintervals via decomposition satisfy the convergence condition of the adaptive Legendre filters. Then the adaptive Legendre filter structure and adaptive weight update algorithm are derived. Final computer simulation results show the effectiveness as well as fast convergence characteristics.

Predicting mass loading as a function of pressure difference across prefilter/HEPA filter systems

International Nuclear Information System (INIS)

Novick, V.J.; Klassen, J.F.; Monson, P.R.

1992-01-01

The purpose of this work is to develop a methodology for predicting the mass loading and pressure drop effects on a prefilter/ HEPA filter system. The methodology relies on the use of empirical equations for the specific resistance of the aerosol loaded filter as a function of the particle diameter. These correlations relate the pressure difference across a filter to the mass loading on the filter and accounts for aerosol particle density effects. These predictions are necessary for the efficient design of new filtration systems and for risk assessment studies of existing filter systems. This work specifically addresses the prefilter/HEPA filter Airborne Activity Confinement Systems (AACS) at the Savannah River Plant. In order to determine the mass loading on the system, it is necessary to establish the efficiency characteristics for the prefilter, the mass loading characteristics of the prefilter measured as a function of pressure difference across the prefilter, and the mass loading characteristics of the HEPA filter as a function of pressure difference across the filter. Furthermore, the efficiency and mass loading characteristics need to be determined as a function of the aerosol particle diameter. A review of the literature revealed that no previous work had been performed to characterize the prefilter material of interest. In order to complete the foundation of information necessary to predict total mass loadings on prefilter/HEPA filter systems, it was necessary to determine the prefilter efficiency and mass loading characteristics. The measured prefilter characteristics combined with the previously determined HEPA filter characteristics allowed the resulting pressure difference across both filters to be predicted as a function of total particle mass for a given particle distribution. These predictions compare favorably to experimental measurements (±25%)

Proceedings of the coal-fired power systems 94: Advances in IGCC and PFBC review meeting. Volume 1

Energy Technology Data Exchange (ETDEWEB)

McDaniel, H.M.; Staubly, R.K.; Venkataraman, V.K. [eds.

1994-06-01

The Coal-Fired Power Systems 94 -- Advances in IGCC and PFBC Review Meeting was held June 21--23, 1994, at the Morgantown Energy Center (METC) in Morgantown, West Virginia. This Meeting was sponsored and hosted by METC, the Office of Fossil Energy, and the US Department of Energy (DOE). METC annually sponsors this conference for energy executives, engineers, scientists, and other interested parties to review the results of research and development projects; to discuss the status of advanced coal-fired power systems and future plans with the industrial contractors; and to discuss cooperative industrial-government research opportunities with METC`s in-house engineers and scientists. Presentations included industrial contractor and METC in-house technology developments related to the production of power via coal-fired Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) systems, the summary status of clean coal technologies, and developments and advancements in advanced technology subsystems, such as hot gas cleanup. A keynote speaker and other representatives from the electric power industry also gave their assessment of advanced power systems. This meeting contained 11 formal sessions and one poster session, and included 52 presentations and 24 poster presentations. Volume I contains papers presented at the following sessions: opening commentaries; changes in the market and technology drivers; advanced IGCC systems; advanced PFBC systems; advanced filter systems; desulfurization system; turbine systems; and poster session. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

AN EFFECTIVE SPAM FILTERING FOR DYNAMIC MAIL MANAGEMENT SYSTEM

Directory of Open Access Journals (Sweden)

S. Arun Mozhi Selvi

2012-04-01

Full Text Available Spam is commonly defined as unsolicited email messages and the goal of spam categorization is to distinguish between spam and legitimate email messages. The economics of spam details that the spammer has to target several recipients with identical and similar email messages. As a result a dynamic knowledge sharing effective defense against a substantial fraction of spam has to be designed which can alternate the burdens of frequent training stand alone spam filter. A weighted email attribute based classification is proposed to mainly focus to encounter the issues in normal email system. These type of classification helps to formulate an effective utilization of our email system by combining the concepts of Bayesian Spam Filtering Algorithm, Iterative Dichotmiser 3(ID3 Algorithm and Bloom Filter. The details captured by the system are processed to track the original sender causing disturbances and prefer them to block further mails from them. We have tested the effectiveness of our scheme by collecting offline data from Yahoo mail & Gmail dumps. This proposal is implemented using .net and sample user-Id for knowledge base.

Digital filter algorithm study and simulation of SSRF feedback system

International Nuclear Information System (INIS)

Han Lifeng; Yuan Renxian; Ye Kairong

2008-01-01

Least Square Fitting was used to design a FIR filter of the transverse feedback system for the Shanghai Synchrotron Radiation Facility (SSRF). The algorithm helped us to set appropriate gain and phase at special frequency points. This reduced the power needed for damping the beam oscillations, which was proved by System View signal simulation. And with AT (Accelerator Tool) simulation, the Gain calculation and settings to the output signals from the FIR filter were deduced. The relationship between the Kicker power and the system damping time was also given. (authors)

Theoretical and experimental study of Chen chaotic system with notch filter feedback control

International Nuclear Information System (INIS)

Ming, Zhang Xiao; Jian-Hua, Peng; Ju-Fang, Chen

2010-01-01

Since the past two decades, the time delay feedback control method has attracted more and more attention in chaos control studies because of its simplicity and efficiency compared with other chaos control schemes. Recently, it has been proposed to suppress low-dimensional chaos with the notch filter feedback control method, which can be implemented in a laser system. In this work, we have analytically determined the controllable conditions for notch filter feedback controlling of Chen chaotic system in terms of the Hopf bifurcation theory. The conditions for notch filter feedback controlled Chen chaoitc system having a stable limit cycle solution are given. Meanwhile, we also analysed the Hopf bifurcation direction, which is very important for parameter settings in notch filter feedback control applications. Finally, we apply the notch filter feedback control methods to the electronic circuit experiments and numerical simulations based on the theoretical analysis. The controlling results of notch filter feedback control method well prove the feasibility and reliability of the theoretical analysis. (general)

Cermet materials, self-cleaning cermet filters, apparatus and systems employing same

Science.gov (United States)

Kong, Peter C.

2005-07-19

A self-cleaning porous cermet material, filter and system utilizing the same may be used in filtering particulate and gaseous pollutants from internal combustion engines having intermetallic and ceramic phases. The porous cermet filter may be made from a transition metal aluminide phase and an alumina phase. Filler materials may be added to increase the porosity or tailor the catalytic properties of the cermet material. Additionally, the cermet material may be reinforced with fibers or screens. The porous filter may also be electrically conductive so that a current may be passed therethrough to heat the filter during use. Further, a heating element may be incorporated into the porous cermet filter during manufacture. This heating element can be coated with a ceramic material to electrically insulate the heating element. An external heating element may also be provided to heat the cermet filter during use.

Design of Filter for a Class of Switched Linear Neutral Systems

Directory of Open Access Journals (Sweden)

Caiyun Wu

2013-01-01

Full Text Available This paper is concerned with the filtering problem for a class of switched linear neutral systems with time-varying delays. The time-varying delays appear not only in the state but also in the state derivatives. Based on the average dwell time approach and the piecewise Lyapunov functional technique, sufficient conditions are proposed for the exponential stability of the filtering error dynamic system. Then, the corresponding solvability condition for a desired filter satisfying a weighted performance is established. All the conditions obtained are delay-dependent. Finally, two numerical examples are given to illustrate the effectiveness of the proposed theory.

Modeling of memristor-based chaotic systems using nonlinear Wiener adaptive filters based on backslash operator

International Nuclear Information System (INIS)

Zhao, Yibo; Jiang, Yi; Feng, Jiuchao; Wu, Lifu

2016-01-01

Highlights: • A novel nonlinear Wiener adaptive filters based on the backslash operator are proposed. • The identification approach to the memristor-based chaotic systems using the proposed adaptive filters. • The weight update algorithm and convergence characteristics for the proposed adaptive filters are derived. - Abstract: Memristor-based chaotic systems have complex dynamical behaviors, which are characterized as nonlinear and hysteresis characteristics. Modeling and identification of their nonlinear model is an important premise for analyzing the dynamical behavior of the memristor-based chaotic systems. This paper presents a novel nonlinear Wiener adaptive filtering identification approach to the memristor-based chaotic systems. The linear part of Wiener model consists of the linear transversal adaptive filters, the nonlinear part consists of nonlinear adaptive filters based on the backslash operator for the hysteresis characteristics of the memristor. The weight update algorithms for the linear and nonlinear adaptive filters are derived. Final computer simulation results show the effectiveness as well as fast convergence characteristics. Comparing with the adaptive nonlinear polynomial filters, the proposed nonlinear adaptive filters have less identification error.

A Novel Approach to the Design of Passive Filters in Electric Grids

Science.gov (United States)

Filho da Costa Castro, José; Lima, Lucas Ramalho; Belchior, Fernando Nunes; Ribeiro, Paulo Fernando

2016-12-01

The design of shunt passive filters has been a topic of constant research since the 70's. Due to the lower cost, passive shunt filters are still considered a preferred option. This paper presents a novel approach for the placement and sizing of passive filters through ranking solutions based on the minimization of the total harmonic distortion (THDV) of the supply system rather than one specific bus, without neglecting the individual harmonic distortions. The developed method was implemented using Matlab/Simulink and applied to a test system. The results shown that is possible to minimize the total voltage harmonic distortion using a system approach during the filter selection. Additionally, since the method is mainly based on a heurist approach, it avoids the complexity associated with of use of advanced mathematical tools such as artificial intelligence techniques. The analyses contemplate a sinusoidal voltage utility and also the condition with background distortion utility.

Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

Science.gov (United States)

Simmons, R B; Crow, S A

1995-01-01

New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

HEAPA Filter Bank In-Place Leak Test for ACUs of Advanced Fuel Science Building in 2010

Energy Technology Data Exchange (ETDEWEB)

Ji, Chul Goo; Bae, Sang Oh [KAERI, Daejeon (Korea, Republic of)

2010-12-15

Air cleaning units installed in the Advanced Fuel Science Building were performed visual inspection, airflow capacity test, and HEAPA filter bank in-place leak test in accordance with ASME N-510-1989. All the above inspections was acceptable. Visual inspection was satisfied to AUC-556 and AUC-557. Airflow capacity was 96%(30,240 m{sup 3}/h) of design airflow capacity(31,500 m{sup 3}/h) for AUC-556 and was 97%(22,800 m{sup 3}/h) of design airflow capacity(22,800 m{sup 3}/h) for AUC-557, and was maintained within {+-}10% of the specified value. Penetration of HEAPA filter bank in-place leak test was 0.009% for AUC-556 and was 0.013% for AUC-557 and these values were maintained less than the acceptance criteria(0.05%)

Manufacturing a low-cost ceramic water filter and filter system for the elimination of common pathogenic bacteria

Science.gov (United States)

Simonis, J. J.; Basson, A. K.

Africa is one of the most water-scarce continents in the world but it is the lack of potable water which results in diarrhoea being the leading cause of death amongst children under the age of five in Africa (696 million children under 5 years old in Africa contract diarrhoea resulting in 2000 deaths per day: WHO and UNICEF, 2009). Most potable water treatment methods use bulk water treatment not suitable or available to the majority of rural poor in Sub-Saharan Africa. One simple but effective way of making sure that water is of good quality is by purifying it by means of a household ceramic water filter. The making and supply of water filters suitable for the removal of suspended solids, pathogenic bacteria and other toxins from drinking water is therefore critical. A micro-porous ceramic water filter with micron-sized pores was developed using the traditional slip casting process. This locally produced filter has the advantage of making use of less raw materials, cost, labour, energy and expertise and being more effective and efficient than other low cost produced filters. The filter is fitted with a silicone tube inserted into a collapsible bag that acts as container and protection for the filter. Enhanced flow is obtained through this filter system. The product was tested using water inoculated with high concentrations of different bacterial cultures as well as with locally polluted stream water. The filter is highly effective (log10 > 4 with 99.99% reduction efficiency) in providing protection from bacteria and suspended solids found in natural water. With correct cleaning and basic maintenance this filter technology can effectively provide drinking water to rural families affected by polluted surface water sources. This is an African solution for the more than 340 million people in Africa without access to clean drinking water (WHO and UNICEF, 2008).

A Hybrid Approach using Collaborative filtering and Content based Filtering for Recommender System

Science.gov (United States)

Geetha, G.; Safa, M.; Fancy, C.; Saranya, D.

2018-04-01

In today’s digital world, it has become an irksome task to find the content of one's liking in an endless variety of content that are being consumed like books, videos, articles, movies, etc. On the other hand there has been an emerging growth among the digital content providers who want to engage as many users on their service as possible for the maximum time. This gave birth to the recommender system comes wherein the content providers recommend users the content according to the users’ taste and liking. In this paper we have proposed a movie recommendation system. A movie recommendation is important in our social life due to its features such as suggesting a set of movies to users based on their interest, or the popularities of the movies. In this paper we are proposing a movie recommendation system that has the ability to recommend movies to a new user as well as the other existing users. It mines movie databases to collect all the important information, such as, popularity and attractiveness, which are required for recommendation. We use content-based and collaborative filtering and also hybrid filtering, which is a combination of the results of these two techniques, to construct a system that provides more precise recommendations concerning movies.

Hybrid extended particle filter (HEPF) for integrated inertial navigation and global positioning systems

International Nuclear Information System (INIS)

Aggarwal, Priyanka; Syed, Zainab; El-Sheimy, Naser

2009-01-01

Navigation includes the integration of methodologies and systems for estimating time-varying position, velocity and attitude of moving objects. Navigation incorporating the integrated inertial navigation system (INS) and global positioning system (GPS) generally requires extensive evaluations of nonlinear equations involving double integration. Currently, integrated navigation systems are commonly implemented using the extended Kalman filter (EKF). The EKF assumes a linearized process, measurement models and Gaussian noise distributions. These assumptions are unrealistic for highly nonlinear systems like land vehicle navigation and may cause filter divergence. A particle filter (PF) is developed to enhance integrated INS/GPS system performance as it can easily deal with nonlinearity and non-Gaussian noises. In this paper, a hybrid extended particle filter (HEPF) is developed as an alternative to the well-known EKF to achieve better navigation data accuracy for low-cost microelectromechanical system sensors. The results show that the HEPF performs better than the EKF during GPS outages, especially when simulated outages are located in periods with high vehicle dynamics

Hybrid Plasma Reactor/Filter for Transportable Collective Protection Systems

Energy Technology Data Exchange (ETDEWEB)

Josephson, Gary B.; Tonkyn, Russell G.; Frye, J. G.; Riley, Brian J.; Rappe, Kenneth G.

2011-04-06

Pacific Northwest National Laboratory (PNNL) has performed an assessment of a Hybrid Plasma/Filter system as an alternative to conventional methods for collective protection. The key premise of the hybrid system is to couple a nonthermal plasma (NTP) reactor with reactive adsorption to provide a broader envelope of protection than can be provided through a single-solution approach. The first step uses highly reactive species (e.g. oxygen radicals, hydroxyl radicals, etc.) created in a nonthermal plasma (NTP) reactor to destroy the majority (~75% - 90%) of an incoming threat. Following the NTP reactor an O3 reactor/filter uses the O3 created in the NTP reactor to further destroy the remaining organic materials. This report summarizes the laboratory development of the Hybrid Plasma Reactor/Filter to protect against a ‘worst-case’ simulant, methyl bromide (CH3Br), and presents a preliminary engineering assessment of the technology to Joint Expeditionary Collective Protection performance specifications for chemical vapor air purification technologies.

Study of LCL filter performance for inverter fed grid connected system

Science.gov (United States)

Thamizh Thentral, T. M.; Geetha, A.; Subramani, C.

2018-04-01

The abandoned use of power electronic converters in the application of grid connected system paves a way for critical injected harmonics. Hence the use of filter becomes a significant play among the present scenario. Higher order passive filter is mostly preferred in this application because of its reduced cost and size. This paper focuses on the design of LCL filter for the reduction of injected harmonics. The reason behind choosing LCL filter is inductor sizing and good ripple component attenuation over the other conventional filters. This work is simulated in MATLAB platform and the results are prominent to the objectives mentioned above. Also, the simulation results are verified with the implemented hardware model.

Homogenous polynomially parameter-dependent H∞ filter designs of discrete-time fuzzy systems.

Science.gov (United States)

Zhang, Huaguang; Xie, Xiangpeng; Tong, Shaocheng

2011-10-01

This paper proposes a novel H(∞) filtering technique for a class of discrete-time fuzzy systems. First, a novel kind of fuzzy H(∞) filter, which is homogenous polynomially parameter dependent on membership functions with an arbitrary degree, is developed to guarantee the asymptotic stability and a prescribed H(∞) performance of the filtering error system. Second, relaxed conditions for H(∞) performance analysis are proposed by using a new fuzzy Lyapunov function and the Finsler lemma with homogenous polynomial matrix Lagrange multipliers. Then, based on a new kind of slack variable technique, relaxed linear matrix inequality-based H(∞) filtering conditions are proposed. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed approach.

Research and Design on Trigger System Based on Acoustic Delay Correlation Filtering

Directory of Open Access Journals (Sweden)

Zhiyong Lei

2014-01-01

Full Text Available In the exterior trajectory test, there usually needs a muzzle or a gun muzzle trigger system to be used as start signal for other measuring device, the customary trigger systems include off- target, infrared and acoustic detection system. But inherent echo reflection of the acoustic detection system makes the original signal of sound trigger submerged in various echo interference for bursts and shooting in a closed room, so that it can’t produce accurate trigger. In order to solve this defect, this paper analyzed the mathematical model based on acoustic delay correlation filtering in detail, then put forward the constraint condition with minimum path for delay correlation filtering. In this constraint condition, delay correlation filtering can do de-noising operation accurately. In order to verify accuracy and actual performance of the model, a MEMS sound sensor was used to implement mathematical model onto project, experimental results show that this system can filter out the every path sound bounce echoes of muzzle shock wave signal and produce the desired trigger signal accurately.

Monorail system for percutaneous repositioning of the Greenfield vena caval filter.

Science.gov (United States)

Guthaner, D F; Wyatt, J O; Mehigan, J T; Wright, A M; Breen, J F; Wexler, L

1990-09-01

The authors describe a technique for removing or repositioning a malpositioned Greenfield inferior vena caval filter. A "monorail" system was used, in which a wire was passed from the femoral vein through the apical hole in the filter and out the internal jugular vein; the wire was held taut from above and below and thus facilitated repositioning or removal of the filter. The technique was used successfully in two cases.

Fuzzy filter for state estimation of a glucoregulatory system.

Science.gov (United States)

Trajanoski, Z; Wach, P

1996-08-01

A filter based on fuzzy logic for state estimation of a glucoregulatory system is presented. A published non-linear model for the dynamics of glucose and its hormonal control including a single glucose compartment, five insulin compartments and a glucagon compartment was used for simulation. The simulated data were corrupted by an additive white noise with zero mean and a coefficient of variation (CV) of between 2 and 20% and then submitted to the state estimation procedure using a fuzzy filter (FF). The performance of the FF was compared with an extended Kalman filter (EKF) for state estimation. Both the FF and the EKF were evaluated in the following cases: (a) five state variables are measurable; three plasma variables are measurable; only plasma glucose is measurable; (b) for different measurement noise levels (CV of 2-20%); and (c) a mismatch between the glucoregulatory system and the given mathematical model (uncertain or approximate model). In contrast to the FF, in the case of approximate model of the glucose system, the EKF failed to achieve useful state estimation. Moreover, the performance of the FF was independent of the noise level. In conclusion, the FF approach is a viable alternative for state estimation in a noisy environment and with an uncertain mathematical model of the glucoregulatory system.

Performance of High Temperature Filter System for Radioactive Waste Vitrification Plant

International Nuclear Information System (INIS)

Park, Seung Chul; Hwang, Tae Won; Shin, Sang Won; Ha, Jong Hyun; Kim, Hey Suk; Park, So Jin

2004-01-01

Important operation parameters and performance of a high temperature ceramic candle filter system were evaluated through a series of demonstration tests at a pilot-scale vitrification plant. At the initial period of each test, due to the growth of dust cake on the surface of ceramic candles, the pressure drop across the filter media increased sharply. After that it became stable to a certain range and varied continuously proportion to the face velocity of off-gas. On the contrary, at the initial period of each test, the permeability of filter element decreased rapidly and then it became stable. Back flushing of the filter system was effective under the back flushing air pressure range of 3∼5 bar. Based on the dust concentrations measured by iso-kinetic dust sampling at the inlet and outlet point of HTF, the dust collection efficiency of HTF evaluated. The result met the designed performance value of 99.9%. During the demonstration tests including a hundred hour long test, no specific failure or problem affecting the performance of HTF system were observed.

On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

Energy Technology Data Exchange (ETDEWEB)

Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Herman, Andrew [CTS Corporation; Bromberg, L. [Massachusetts Institute of Technology (MIT); Prikhodko, Vitaly Y [ORNL; Parks, II, James E [ORNL; Storey, John Morse [ORNL

2017-01-01

The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.

Over-the-Horizon Awareness for Advanced Driver Assistance Systems: the TrafficFilter and microSlotted 1-Persistence Flooding

NARCIS (Netherlands)

van Eenennaam, Martijn; Heijenk, Geert; Karagiannis, Georgios; van Arem, Bart

2011-01-01

Vehicle-to-vehicle communications (V2V) is a promising technique for Advanced Driver Assistance Systems to increase traffic safety and efficiency. A proposed system is the Congestion Assistant, which supports drivers when approaching and driving in traffic congestion. Studies have shown great

ACTIVE FILTER HARDWARE DESIGN and PERFORMANCE FOR THE DIII-D PLASMA CONTROL SYSTEM

International Nuclear Information System (INIS)

SELLERS, D.; FERRON, J.R; WALKER, M.L; BROESCH, J.D

2004-03-01

OAK-B135 The digital plasma control system (PCS), currently in operation on the DIII-D tokamak, requires inputs from a large number of sensors. Due to the nature of the digitizers and the relative noisy environment from which these signals are derived, each of the 32 signals must be conditioned via an active filter. Two different types of filters, Chebyshev and Bessel with fixed frequencies: 100 Hz Bessel was used for filtering the motional Stark effect diagnostic data. 800 Hz Bessel was designed to filter plasma control data and 1200 Hz Chebyshev is used with closed loop control of choppers. The performance of the plasma control system is greatly influenced by how well the actual filter responses match the software model used in the control system algorithms. This paper addresses the various issues facing the designer in matching the electrical design with the theoretical

A hybrid active filter for damping of harmonic resonance in industrial power systems

OpenAIRE

Fujita, Hideaki; Yamasaki, Takahiro; Akagi, Hirofumi

1998-01-01

This paper proposes a hybrid active filter for damping of harmonic resonance in industrial power systems. The hybrid filter consists of a small-rated active filter and a 5th tuned passive filter. The active filter is characterized by detecting the 5th harmonic current flowing into the passive filter. It is controlled in such a way as to behave as a negative or positive resistor by adjusting a feedback gain from a negative to positive value, and vice versa. The negative resistor presented by t...

NASA Advanced Explorations Systems: Advancements in Life Support Systems

Science.gov (United States)

Shull, Sarah A.; Schneider, Walter F.

2016-01-01

The NASA Advanced Exploration Systems (AES) Life Support Systems (LSS) project strives to develop reliable, energy-efficient, and low-mass spacecraft systems to provide environmental control and life support systems (ECLSS) critical to enabling long duration human missions beyond low Earth orbit (LEO). Highly reliable, closed-loop life support systems are among the capabilities required for the longer duration human space exploration missions assessed by NASA's Habitability Architecture Team (HAT). The LSS project is focused on four areas: architecture and systems engineering for life support systems, environmental monitoring, air revitalization, and wastewater processing and water management. Starting with the international space station (ISS) LSS systems as a point of departure (where applicable), the mission of the LSS project is three-fold: 1. Address discrete LSS technology gaps 2. Improve the reliability of LSS systems 3. Advance LSS systems towards integrated testing on the ISS. This paper summarized the work being done in the four areas listed above to meet these objectives. Details will be given on the following focus areas: Systems Engineering and Architecture- With so many complex systems comprising life support in space, it is important to understand the overall system requirements to define life support system architectures for different space mission classes, ensure that all the components integrate well together and verify that testing is as representative of destination environments as possible. Environmental Monitoring- In an enclosed spacecraft that is constantly operating complex machinery for its own basic functionality as well as science experiments and technology demonstrations, it's possible for the environment to become compromised. While current environmental monitors aboard the ISS will alert crew members and mission control if there is an emergency, long-duration environmental monitoring cannot be done in-orbit as current methodologies

Evaluation of water quality functions of conventional and advanced soil-based onsite wastewater treatment systems.

Science.gov (United States)

Cooper, Jennifer A; Loomis, George W; Kalen, David V; Amador, Jose A

2015-05-01

Shallow narrow drainfields are assumed to provide better wastewater renovation than conventional drainfields and are used for protection of surface and ground water. To test this assumption, we evaluated the water quality functions of two advanced onsite wastewater treatment system (OWTS) drainfields-shallow narrow (SND) and Geomat (GEO)-and a conventional pipe and stone (P&S) drainfield over 12 mo using replicated ( = 3) intact soil mesocosms. The SND and GEO mesocosms received effluent from a single-pass sand filter, whereas the P&S received septic tank effluent. Between 97.1 and 100% of 5-d biochemical oxygen demand (BOD), fecal coliform bacteria, and total phosphorus (P) were removed in all drainfield types. Total nitrogen (N) removal averaged 12.0% for P&S, 4.8% for SND, and 5.4% for GEO. A mass balance analysis accounted for 95.1% (SND), 94.1% (GEO), and 87.6% (P&S) of N inputs. When the whole treatment train (excluding the septic tank) is considered, advanced systems, including sand filter pretreatment and SND or GEO soil-based treatment, removed 99.8 to 99.9% of BOD, 100% of fecal coliform bacteria and P, and 26.0 to 27.0% of N. In contrast, the conventional system removed 99.4% of BOD and 100% of fecal coliform bacteria and P but only 12.0% of N. All drainfield types performed similarly for most water quality functions despite differences in placement within the soil profile. However, inclusion of the pretreatment step in advanced system treatment trains results in better N removal than in conventional treatment systems despite higher drainfield N removal rates in the latter. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Numerical Analysis of a Passive Containment Filtered Venting System

International Nuclear Information System (INIS)

Kim, Taejoon; Ha, Huiun; Heo, Sun

2014-01-01

The passive Containment Filtered Venting system (CFVS) does not have principally any kind of isolation valves or filtering devices which need periodic maintenance. In this study, the hydro-thermal analysis is presented to investigate the existence of flow instability in the passive CFVS and its performance under the pressure change of APR+ containment building with LB-LOCA M/E data. The Passive Containment Filtered Venting System was suggested as a part in i-Power development project and the operation mechanism was investigated by numerical modeling and simulation using GOTHIC8.0 system code. There are four Phases for consideration to investigate the pressurization of the containment building, loss of hydrostatic head in the pipe line of CFVS, opening of pipe line and gas ejection to the coolant tank, and the head recovery inside the pipe as the containment gas exhausted. The simulation results show that gas generation rate determine the timing of head recovery in the CFVS pipe line and that the equipment of various devices inducing pressure loss at the pipe can give the capacity of Phase control of the passive CFVS operation

System on Package (SoP) Millimeter Wave Filters for 5G Applications

KAUST Repository

Showail, Jameel

2018-05-01

Bandpass filters are an essential component of wireless communication systems that only transmits frequencies corresponding to the communication band and rejects all other frequencies. As the deployment of 5G draws nearer, first deployments are expected in 2020 [1], the need for viable filters at the new frequency bands becomes more imminent. Size and performance are two critical considerations for a filter that will be used in emerging mobile communication applications. The high frequency of 5G communication, 28 GHz as opposed to sub 6 GHz for nearly all previous communication protocols, means that previously utilized lumped component based solutions cannot be implemented since they are ill-suited for mm-wave applications. The focus of this work is the miniaturization of a high-performance filter. The Substrate Integrated Waveguide (SIW) is a high performance and promising structure and Low Temperature Co-Fired Ceramic (LTCC) is a high-performance material that both can operate at higher frequencies than the technologies used for previous telecommunication generations. To miniaturize the structure, a compact folded four-cavity SIW filter is designed, implemented and tested. The feeding structure is integrated into the filter to exploit the System on Package (SoP) attributes of LTCC and further reduce the total area of the filter individually and holistically when looking at the final integrated system. Two unique three dimensional (3D) integrated SoP LTCC two-stage SIW single cavity filters and one unique four-cavity filter all with embedded planar resonators are designed, fabricated and tested. The embedded resonators create a two-stage effect in a single cavity filter. The better single cavity design provides a 15% fractional bandwidth at a center frequency of 28.12 GHz, and with an insertion loss of -0.53 dB. The fabricated four-cavity filter has a 3-dB bandwidth of .98GHz centered at 27.465 GHz, and with an insertion loss of -2.66 dB. The designs presented

Inverter Output Filter Effect on PWM Motor Drives of a Flywheel Energy Storage System

Science.gov (United States)

Santiago, Walter

2004-01-01

NASA Glenn Research Center (GRC) has been involved in the research and development of high speed flywheel systems for small satellite energy storage and attitude control applications. One research and development area has been the minimization of the switching noise produced by the pulsed width modulated (PWM) inverter that drives the flywheel permanent magnet motor/generator (PM M/G). This noise can interfere with the flywheel M/G hardware and the system avionics hampering the full speed performance of the flywheel system. One way to attenuate the inverter switching noise is by placing an AC filter at the three phase output terminals of the inverter with the filter neutral point connected to the DC link (DC bus) midpoint capacitors. The main benefit of using an AC filter in this fashion is the significant reduction of the inverter s high dv/dt switching and its harmonics components. Additionally, common mode (CM) and differential mode (DM) voltages caused by the inverter s high dv/dt switching are also reduced. Several topologies of AC filters have been implemented and compared. One AC filter topology consists of a two-stage R-L-C low pass filter. The other topology consists of the same two-stage R-L-C low pass filter with a series connected trap filter (an inductor and capacitor connected in parallel). This paper presents the analysis, design and experimental results of these AC filter topologies and the comparison between the no filter case and conventional AC filter.

Evaluation of bistable systems versus matched filters in detecting bipolar pulse signals

OpenAIRE

Duan, Fabing; Abbott, Derek; Gao, Qisheng

2004-01-01

This paper presents a thorough evaluation of a bistable system versus a matched filter in detecting bipolar pulse signals. The detectability of the bistable system can be optimized by adding noise, i.e. the stochastic resonance (SR) phenomenon. This SR effect is also demonstrated by approximate statistical detection theory of the bistable system and corresponding numerical simulations. Furthermore, the performance comparison results between the bistable system and the matched filter show that...

Adaptation of a Filter Assembly to Assess Microbial Bioburden of Pressurant Within a Propulsion System

Science.gov (United States)

Benardini, James N.; Koukol, Robert C.; Schubert, Wayne W.; Morales, Fabian; Klatte, Marlin F.

2012-01-01

A report describes an adaptation of a filter assembly to enable it to be used to filter out microorganisms from a propulsion system. The filter assembly has previously been used for particulates greater than 2 micrometers. Projects that utilize large volumes of nonmetallic materials of planetary protection concern pose a challenge to their bioburden budget, as a conservative specification value of 30 spores per cubic centimeter is typically used. Helium was collected utilizing an adapted filtration approach employing an existing Millipore filter assembly apparatus used by the propulsion team for particulate analysis. The filter holder on the assembly has a 47-mm diameter, and typically a 1.2-5 micrometer pore-size filter is used for particulate analysis making it compatible with commercially available sterilization filters (0.22 micrometers) that are necessary for biological sampling. This adaptation to an existing technology provides a proof-of-concept and a demonstration of successful use in a ground equipment system. This adaptation has demonstrated that the Millipore filter assembly can be utilized to filter out microorganisms from a propulsion system, whereas in previous uses the filter assembly was utilized for particulates greater than 2 micrometers.

Nonlinear stochastic systems with incomplete information filtering and control

CERN Document Server

Shen, Bo; Shu, Huisheng

2013-01-01

Nonlinear Stochastic Processes addresses the frequently-encountered problem of incomplete information. The causes of this problem considered here include: missing measurements; sensor delays and saturation; quantization effects; and signal sampling. Divided into three parts, the text begins with a focus on H∞ filtering and control problems associated with general classes of nonlinear stochastic discrete-time systems. Filtering problems are considered in the second part, and in the third the theory and techniques previously developed are applied to the solution of issues arising in complex networks with the design of sampled-data-based controllers and filters. Among its highlights, the text provides: ·         a unified framework for handling filtering and control problems in complex communication networks with limited bandwidth; ·         new concepts such as random sensor and signal saturations for more realistic modeling; and ·         demonstration of the use of techniques such...

Adaptive iterated function systems filter for images highly corrupted with fixed - Value impulse noise

Science.gov (United States)

Shanmugavadivu, P.; Eliahim Jeevaraj, P. S.

2014-06-01

The Adaptive Iterated Functions Systems (AIFS) Filter presented in this paper has an outstanding potential to attenuate the fixed-value impulse noise in images. This filter has two distinct phases namely noise detection and noise correction which uses Measure of Statistics and Iterated Function Systems (IFS) respectively. The performance of AIFS filter is assessed by three metrics namely, Peak Signal-to-Noise Ratio (PSNR), Mean Structural Similarity Index Matrix (MSSIM) and Human Visual Perception (HVP). The quantitative measures PSNR and MSSIM endorse the merit of this filter in terms of degree of noise suppression and details/edge preservation respectively, in comparison with the high performing filters reported in the recent literature. The qualitative measure HVP confirms the noise suppression ability of the devised filter. This computationally simple noise filter broadly finds application wherein the images are highly degraded by fixed-value impulse noise.

Advanced information processing system for advanced launch system: Avionics architecture synthesis

Science.gov (United States)

Lala, Jaynarayan H.; Harper, Richard E.; Jaskowiak, Kenneth R.; Rosch, Gene; Alger, Linda S.; Schor, Andrei L.

1991-01-01

The Advanced Information Processing System (AIPS) is a fault-tolerant distributed computer system architecture that was developed to meet the real time computational needs of advanced aerospace vehicles. One such vehicle is the Advanced Launch System (ALS) being developed jointly by NASA and the Department of Defense to launch heavy payloads into low earth orbit at one tenth the cost (per pound of payload) of the current launch vehicles. An avionics architecture that utilizes the AIPS hardware and software building blocks was synthesized for ALS. The AIPS for ALS architecture synthesis process starting with the ALS mission requirements and ending with an analysis of the candidate ALS avionics architecture is described.

Retrofitting of activated charcoal filters in the iodine removal system of Cirus reactor

International Nuclear Information System (INIS)

Arora, M.K.; Thomas, Shibu; Ullas, O.P.; Sharma, V.K.; Singh, Kapil Deo S.

2002-01-01

Full text: The emergency exhaust system for removal of iodine in the 40 MWt Cirus reactor consisted of a caustic scrubber followed by a bank of silver-coated copper mesh filters. The latter filter elements are no longer commercially available, and moreover, there is need to upgrade the system to meet the current safety norms. An iodine removal system based on activated charcoal adsorbers has been selected for this purpose. The design of the system ensures high iodine removal efficiency and thermal safety of the filters for a postulated accident condition beyond design basis accident. The new iodine removal system has been retrofitted during the current refurbishing programme of Cirus and it has been commissioned and tested satisfactorily

Controlling flow conditions of test filters in iodine filters

International Nuclear Information System (INIS)

Holmberg, R.; Laine, J.

1979-03-01

Several different iodine filter and test filter designs and experience gained from their operation are presented. For the flow experiments, an iodine filter system equipped with flow regulating and measuring devices was built. In the experiments the influence of the packing method of the iodine sorption material and the influence of the flow regulating and measuring divices upon the flow conditions in the test filters was studied. On the basis of the experiments it has been shown that the flows through the test filters always can be adjusted to a correct value if there only is a high enough pressure difference available across the test filter ducting. As a result of the research, several different methods are presented with which the flows through the test filters in both operating and future iodine sorption system can easily be measured and adjusted to their correct values. (author)

Air-mass flux measurement system using Doppler-shifted filtered Rayleigh scattering

Science.gov (United States)

Shirley, John A.; Winter, Michael

1993-01-01

An optical system has been investigated to measure mass flux distributions in the inlet of a high speed air-breathing propulsion system. Rayleigh scattered light from air is proportional to the number density of molecules and hence can be used to ascertain the gas density in a calibrated system. Velocity field measurements are achieved by spectrally filtering the elastically-scattered Doppler-shifted light with an absorbing molecular filter. A novel anamorphic optical collection system is used which allows optical rays from different scattering angles, that have different Doppler shifts, to be recorded separately. This is shown to obviate the need to tune the laser through the absorption to determine velocities, while retaining the ability to make spatially-resolved measurements along a line. By properly selecting the laser tuning and filter parameters, simultaneous density measurements can be made. These properties are discussed in the paper and experiments demonstrating the velocimetry capability are described.

Passive Target Tracking in Non-cooperative Radar System Based on Particle Filtering

Institute of Scientific and Technical Information of China (English)

LI Shuo; TAO Ran

2006-01-01

We propose a target tracking method based on particle filtering(PF) to solve the nonlinear non-Gaussian target-tracking problem in the bistatic radar systems using external radiation sources. Traditional nonlinear state estimation method is extended Kalman filtering (EKF), which is to do the first level Taylor series extension. It will cause an inaccuracy or even a scatter estimation result on condition that there is either a highly nonlinear target or a large noise square-error. Besides, Kalman filtering is the optimal resolution under a Gaussian noise assumption, and is not suitable to the non-Gaussian condition. PF is a sort of statistic filtering based on Monte Carlo simulation that is using some random samples (particles) to simulate the posterior probability density of system random variables. This method can be used in any nonlinear random system. It can be concluded through simulation that PF can achieve higher accuracy than the traditional EKF.

Neural network training by Kalman filtering in process system monitoring

International Nuclear Information System (INIS)

Ciftcioglu, Oe.

1996-03-01

Kalman filtering approach for neural network training is described. Its extended form is used as an adaptive filter in a nonlinear environment of the form a feedforward neural network. Kalman filtering approach generally provides fast training as well as avoiding excessive learning which results in enhanced generalization capability. The network is used in a process monitoring application where the inputs are measurement signals. Since the measurement errors are also modelled in Kalman filter the approach yields accurate training with the implication of accurate neural network model representing the input and output relationships in the application. As the process of concern is a dynamic system, the input source of information to neural network is time dependent so that the training algorithm presents an adaptive form for real-time operation for the monitoring task. (orig.)

Far-Infrared Based Pedestrian Detection for Driver-Assistance Systems Based on Candidate Filters, Gradient-Based Feature and Multi-Frame Approval Matching.

Science.gov (United States)

Wang, Guohua; Liu, Qiong

2015-12-21

Far-infrared pedestrian detection approaches for advanced driver-assistance systems based on high-dimensional features fail to simultaneously achieve robust and real-time detection. We propose a robust and real-time pedestrian detection system characterized by novel candidate filters, novel pedestrian features and multi-frame approval matching in a coarse-to-fine fashion. Firstly, we design two filters based on the pedestrians' head and the road to select the candidates after applying a pedestrian segmentation algorithm to reduce false alarms. Secondly, we propose a novel feature encapsulating both the relationship of oriented gradient distribution and the code of oriented gradient to deal with the enormous variance in pedestrians' size and appearance. Thirdly, we introduce a multi-frame approval matching approach utilizing the spatiotemporal continuity of pedestrians to increase the detection rate. Large-scale experiments indicate that the system works in real time and the accuracy has improved about 9% compared with approaches based on high-dimensional features only.

Far-Infrared Based Pedestrian Detection for Driver-Assistance Systems Based on Candidate Filters, Gradient-Based Feature and Multi-Frame Approval Matching

Directory of Open Access Journals (Sweden)

Guohua Wang

2015-12-01

Full Text Available Far-infrared pedestrian detection approaches for advanced driver-assistance systems based on high-dimensional features fail to simultaneously achieve robust and real-time detection. We propose a robust and real-time pedestrian detection system characterized by novel candidate filters, novel pedestrian features and multi-frame approval matching in a coarse-to-fine fashion. Firstly, we design two filters based on the pedestrians’ head and the road to select the candidates after applying a pedestrian segmentation algorithm to reduce false alarms. Secondly, we propose a novel feature encapsulating both the relationship of oriented gradient distribution and the code of oriented gradient to deal with the enormous variance in pedestrians’ size and appearance. Thirdly, we introduce a multi-frame approval matching approach utilizing the spatiotemporal continuity of pedestrians to increase the detection rate. Large-scale experiments indicate that the system works in real time and the accuracy has improved about 9% compared with approaches based on high-dimensional features only.

Data-Filtering System to Avoid Total Data Distortion in IoT Networking

Directory of Open Access Journals (Sweden)

Dae-Young Kim

2017-01-01

Full Text Available In the Internet of Things (IoT networking, numerous objects are connected to a network. They sense events and deliver the sensed information to the cloud. A lot of data is generated in the IoT network, and servers in the cloud gather the sensed data from the objects. Then, the servers analyze the collected data and provide proper intelligent services to users through the results of the analysis. When the server analyzes the collected data, if there exists malfunctioning data, distortional results of the analysis will be generated. The distortional results lead to misdirection of the intelligent services, leading to poor user experience. In the analysis for intelligent services in IoT, malfunctioning data should be avoided because integrity of the collected data is crucial. Therefore, this paper proposes a data-filtering system for the server in the cloud. The proposed data-filtering system is placed in front of the server and firstly receives the sensed data from the objects. It employs the naïve Bayesian classifier and, by learning, classifies the malfunctioning data from among the collected data. Data with integrity is delivered to the server for analysis. Because the proposed system filters the malfunctioning data, the server can obtain accurate analysis results and reduce computing load. The performance of the proposed data-filtering system is evaluated through computer simulation. Through the simulation results, the efficiency of the proposed data-filtering system is shown.

Performance test of filtering system for controlling the turbidity of secondary cooling water in HANARO

International Nuclear Information System (INIS)

Park, Y. C.; Woo, J. S.; Jo, Y. K.; Loo, J. S.; Lim, N. Y.

2001-01-01

There is about 80 m 3 /h loss of the secondary cooling water by evaporation, windage and blowdown during the operation of HANARO, 30 MW research reactor. When the secondary cooling water is treated by high Ca-hardness treatment program for minimizing the blowdown loss, only the trubidity exceeds the limit. By adding filtering system it was confirned, through the relation of turbidity and filtering rate of secondary cooling water, that the turbidity is reduced below the limit (5 deg.) by 2 % of filtering rate without blowdown. And it was verified, through the field performace test of filtering system under normal operation condition, that the circulation pumps get proper capacity and that filter units reduce the turbidity below the limit. Therefore, the secondary cooling water can be treated by the high Ca-hardness program and filter system without blowdown

Subspace System Identification of the Kalman Filter

Directory of Open Access Journals (Sweden)

David Di Ruscio

2003-07-01

Full Text Available Some proofs concerning a subspace identification algorithm are presented. It is proved that the Kalman filter gain and the noise innovations process can be identified directly from known input and output data without explicitly solving the Riccati equation. Furthermore, it is in general and for colored inputs, proved that the subspace identification of the states only is possible if the deterministic part of the system is known or identified beforehand. However, if the inputs are white, then, it is proved that the states can be identified directly. Some alternative projection matrices which can be used to compute the extended observability matrix directly from the data are presented. Furthermore, an efficient method for computing the deterministic part of the system is presented. The closed loop subspace identification problem is also addressed and it is shown that this problem is solved and unbiased estimates are obtained by simply including a filter in the feedback. Furthermore, an algorithm for consistent closed loop subspace estimation is presented. This algorithm is using the controller parameters in order to overcome the bias problem.

Development of laundry drainage treatment system with ceramic ultra filter

International Nuclear Information System (INIS)

Kanda, Masanori; Kurahasi, Takafumi

1995-01-01

A compact laundry drainage treatment system (UF system hereafter) with a ceramic ultra filter membrane (UF membrane hereafter) has been developed to reduce radioactivity in laundry drainage from nuclear power plants. The UF membrane is made of sintered fine ceramic. The UF membrane has 0.01 μm fine pores, resulting in a durable, heat-resistant, and corrosion-resistant porous ceramic filter medium. A cross-flow system, laundry drainage is filtrated while it flows across the UF membrane, is used as the filtration method. This method creates less caking when compared to other methods. The UF membrane is back washed at regular intervals with permeated water to minimize caking of the filter. The UF membrane and cross-flow system provides long stable filtration. The ceramic UF membrane is strong enough to concentrate suspended solids in laundry drainage up to a weight concentration of 10%. The final concentrated laundry drainage can be treated in an incinerator. The performance of the UF system was checked using radioactive laundry drainage. The decontamination factor of the UF system was 25 or more. The laundry drainage treatment capacity and concentration ratio of the UF system, as well as the service life of the UF membrane were also checked by examination using simulated non-radioactive laundry drainage. Even though laundry drainage was concentrated 1000 times, the UF system showed good permeated water quality and permeated water flux. (author)

ASSESSMENT OF THE PCFBC-EXPOSED AND ACCELERATED LIFE-TESTED CANDLE FILTERS; TOPICAL

International Nuclear Information System (INIS)

M.A. Alvin

1999-01-01

Development of the hot gas filtration technology has been the focus of DOE/FETC and Siemens Westinghouse Power Corporation during the past twenty years. Systems development during this time has successfully lead to the generation and implementation of high temperature Siemens Westinghouse particulate filtration systems that are currently installed and are operational at Demonstration Plant sites, and which are ready for installation at commercial plant sites. Concurrently, materials development has advanced the use of commercially available oxide- and nonoxide-based monoliths, and has fostered the manufacture and use of second generation, oxide-based, continuous fiber reinforced ceramic composites and filament wound materials. This report summarizes the material characterization results for commercially available and second generation filter materials tested in Siemens Westinghouse's advanced, high temperature, particulate removal system at the Foster Wheeler, pressurized circulating fluidized-bed combustion, pilot-scale test facility in Karhula, Finland, and subsequent extended accelerated life testing of aged elements in Siemens Westinghouse pressurized fluidized-bed combustion simulator test facility in Pittsburgh, PA. The viability of operating candle filters successfully for over 1 year of service life has been shown in these efforts. Continued testing to demonstrate the feasibility of acquiring three years of service operation on aged filter elements is recommended

Requirements for a cleanable steel HEPA filter derived from a systems analysis

International Nuclear Information System (INIS)

Bergman, W.

1996-06-01

A systems analysis was conducted to determine customer requirements for a cleanable high efficiency particulate air (HEPA) filter in DOE Environmental Management (EM) facilities. The three principal drivers for cleanable steel HEPA are large cost savings, improved filter reliability, and new regulations; they produce a strong incentive to DOE customers to use cleanable steel HEPA filters. Input for customer requirements were obtained from field trips to EM sites and from discussions. Most existing applications require that cleanable steel HEPA filters meet size/performance requirements of standard glass HEPA filters; applications in new facilities can relax size/weight/pressure drop requirements on a case-by-case basis. We then obtained input from commercial firms on availability of cleanable steel HEPA filters. Systems analysis then showed that currently available technology was only able to meet customer needs in a limited number of cases. Further development is needed to meet requirements of EM customers. For cleanable steel HEPA to be retrofitted into existing systems, pressure drop and weight must be reduced. Pressure drop can be reduced by developing steel fiber media from 0.5 μm dia steel fibers. Weight can be reduced by packaging the steel fiber media in one of the standard HEPA configurations. Although most applications will be able to use standard 304 or 316L alloys, an acid resistant alloy such as Hastelloy or Inconel will be needed for incinerator and other thermal processes

Hybrid three-dimensional variation and particle filtering for nonlinear systems

International Nuclear Information System (INIS)

Leng Hong-Ze; Song Jun-Qiang

2013-01-01

This work addresses the problem of estimating the states of nonlinear dynamic systems with sparse observations. We present a hybrid three-dimensional variation (3DVar) and particle piltering (PF) method, which combines the advantages of 3DVar and particle-based filters. By minimizing the cost function, this approach will produce a better proposal distribution of the state. Afterwards the stochastic resampling step in standard PF can be avoided through a deterministic scheme. The simulation results show that the performance of the new method is superior to the traditional ensemble Kalman filtering (EnKF) and the standard PF, especially in highly nonlinear systems

Investigations into the design of a filter system for PWR containment venting

International Nuclear Information System (INIS)

Dillmann, H.G.; Wilhelm, J.G.

1991-01-01

The reactors of power stations in the Federal Republic of Germany are being or have already been equipped with systems for containment venting under severe accident conditions. Two different offgas cleaning systems are available. One system, realizing a complete passive filtering concept, consists of a multistage metal fiber filter for coarse particulates and aerosol removal and an additional molecular sieve filter for gaseous iodine retention connected in series. The requirements made with respect to aerosol filtration includes among others the capability of retaining 60 kg of a recondensing aerosol with a 0.5 μm mean geometric mass diameter. BaSO 4 and SnO 2 were used as tracer aerosols in the experiments. All the decontamination factors were > 1,000. Vaporous iodine is removed on molecular sieve filters (zeolite filters) subsequent to airborne particulate filtration. As Ag-zeolites act as catalysts in the H 2 O 2 reaction and thus might give rise to a violent exothermal reaction, the catalytic effect was suppressed by substituting mixed doping for doping solely with silver. The removal efficiencies achieved with Ag-zeolites and zeolites with mixed doping in air-steam mixtures are indicated, and investigations of the catalytic behavior in air-steam-H 2 mixtures are described

Design Criteria for DC Link Filters in a Synchronous Generator-Phase Controlled Rectifier-Filter-Load System

National Research Council Canada - National Science Library

Greseth, Gregory

1999-01-01

.... The proposed Navy DC Zonal Electrical Distribution System (DC ZEDS) being designed for the new DD-21 utilizes a rectified ac generator output which is filtered and stepped to usable voltages by local dc-dc converters...

Parameter estimation for stiff deterministic dynamical systems via ensemble Kalman filter

International Nuclear Information System (INIS)

Arnold, Andrea; Calvetti, Daniela; Somersalo, Erkki

2014-01-01

A commonly encountered problem in numerous areas of applications is to estimate the unknown coefficients of a dynamical system from direct or indirect observations at discrete times of some of the components of the state vector. A related problem is to estimate unobserved components of the state. An egregious example of such a problem is provided by metabolic models, in which the numerous model parameters and the concentrations of the metabolites in tissue are to be estimated from concentration data in the blood. A popular method for addressing similar questions in stochastic and turbulent dynamics is the ensemble Kalman filter (EnKF), a particle-based filtering method that generalizes classical Kalman filtering. In this work, we adapt the EnKF algorithm for deterministic systems in which the numerical approximation error is interpreted as a stochastic drift with variance based on classical error estimates of numerical integrators. This approach, which is particularly suitable for stiff systems where the stiffness may depend on the parameters, allows us to effectively exploit the parallel nature of particle methods. Moreover, we demonstrate how spatial prior information about the state vector, which helps the stability of the computed solution, can be incorporated into the filter. The viability of the approach is shown by computed examples, including a metabolic system modeling an ischemic episode in skeletal muscle, with a high number of unknown parameters. (paper)

Integrated nitrogen removal biofilter system with ceramic membrane for advanced post-treatment of municipal wastewater.

Science.gov (United States)

Son, Dong-Jin; Yun, Chan-Young; Kim, Woo-Yeol; Zhang, Xing-Ya; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

2016-12-01

The pre-denitrification biofilm process for nitrogen removal was combined with ceramic membrane with pore sizes of 0.05-0.1 µm as a system for advanced post-treatment of municipal wastewater. The system was operated under an empty bed hydraulic retention time of 7.8 h, recirculation ratio of 3, and transmembrane pressure of 0.47 bar. The system showed average removals of organics, total nitrogen, and solids as high as 93%, 80%, and 100%, respectively. Rapid nitrification could be achieved and denitrification was performed in the anoxic filter without external carbon supplements. The residual particulate organics and nitrogen in effluent from biofilm process could be also removed successfully through membrane filtration and the removal of total coliform was noticeably improved after membrane filtration. Thus, a system composed of the pre-denitrification biofilm process with ceramic membrane would be a compact and flexible option for advanced post-treatment of municipal wastewater.

Phosphorus retention in a 20-year-old septic system filter bed.

Science.gov (United States)

Robertson, W D

2012-01-01

Septic systems in lakeshore environments often occur where thin soils overlie bedrock and, consequently, filter beds may be constructed of imported filter sand. The objective of this study was to assess the mobility of wastewater phosphorus (P) in such a potentially vulnerable setting by examining a 20-yr-old domestic septic system located near Parry Sound, ON, Canada, where the filter bed is constructed of imported noncalcareous sand. The groundwater plume is acidic (pH 6.0) and has a zone of elevated PO-P (up to 3.1 ± 1.7 mg L) below the tile lines but no elevated PO-P is present beyond 5 m from the tile lines. Elevated concentrations of desorbable P (up to 137 mg kg) and acid-extractable P (up to 3210 mg kg) occur in the filter sand within 1 m below four of seven tile lines present and the total mass of excess acid-extractable P (39 kg) is similar to the estimated total lifetime P loading to the system (33 kg). Microprobe images reveal abundant Fe and Al-rich authigenic mineral coatings on the sand grains that are increasingly P rich (up to 10% w/w P) near the tile lines. Additionally, 6 yr of monitoring data show that groundwater PO concentrations are not increasing. This indicates that mineral precipitation, not adsorption, dominates P immobilization at this site. This example of robust long-term P retention opens up the possibility of improving P removal in on-site treatment systems by prescribing specific sand types for filter bed construction. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A multi-standard active-RC filter with accurate tuning system

International Nuclear Information System (INIS)

Ma Heping; Yuan Fang; Shi Yin; Dai, F F

2009-01-01

A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 μm 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm 2 and 0.11 mm 2 (calibration circuit excluded), respectively.

Filter replacement lifetime prediction

Science.gov (United States)

Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

2017-10-25

Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

Linear filters as a method of real-time prediction of geomagnetic activity

International Nuclear Information System (INIS)

McPherron, R.L.; Baker, D.N.; Bargatze, L.F.

1985-01-01

Important factors controlling geomagnetic activity include the solar wind velocity, the strength of the interplanetary magnetic field (IMF), and the field orientation. Because these quantities change so much in transit through the solar wind, real-time monitoring immediately upstream of the earth provides the best input for any technique of real-time prediction. One such technique is linear prediction filtering which utilizes past histories of the input and output of a linear system to create a time-invariant filter characterizing the system. Problems of nonlinearity or temporal changes of the system can be handled by appropriate choice of input parameters and piecewise approximation in various ranges of the input. We have created prediction filters for all the standard magnetic indices and tested their efficiency. The filters show that the initial response of the magnetosphere to a southward turning of the IMF peaks in 20 minutes and then again in 55 minutes. After a northward turning, auroral zone indices and the midlatitude ASYM index return to background within 2 hours, while Dst decays exponentially with a time constant of about 8 hours. This paper describes a simple, real-time system utilizing these filters which could predict a substantial fraction of the variation in magnetic activity indices 20 to 50 minutes in advance

An adaptive deep-coupled GNSS/INS navigation system with hybrid pre-filter processing

Science.gov (United States)

Wu, Mouyan; Ding, Jicheng; Zhao, Lin; Kang, Yingyao; Luo, Zhibin

2018-02-01

The deep-coupling of a global navigation satellite system (GNSS) with an inertial navigation system (INS) can provide accurate and reliable navigation information. There are several kinds of deeply-coupled structures. These can be divided mainly into coherent and non-coherent pre-filter based structures, which have their own strong advantages and disadvantages, especially in accuracy and robustness. In this paper, the existing pre-filters of the deeply-coupled structures are analyzed and modified to improve them firstly. Then, an adaptive GNSS/INS deeply-coupled algorithm with hybrid pre-filters processing is proposed to combine the advantages of coherent and non-coherent structures. An adaptive hysteresis controller is designed to implement the hybrid pre-filters processing strategy. The simulation and vehicle test results show that the adaptive deeply-coupled algorithm with hybrid pre-filters processing can effectively improve navigation accuracy and robustness, especially in a GNSS-challenged environment.

Linear theory for filtering nonlinear multiscale systems with model error.

Science.gov (United States)

Berry, Tyrus; Harlim, John

2014-07-08

In this paper, we study filtering of multiscale dynamical systems with model error arising from limitations in resolving the smaller scale processes. In particular, the analysis assumes the availability of continuous-time noisy observations of all components of the slow variables. Mathematically, this paper presents new results on higher order asymptotic expansion of the first two moments of a conditional measure. In particular, we are interested in the application of filtering multiscale problems in which the conditional distribution is defined over the slow variables, given noisy observation of the slow variables alone. From the mathematical analysis, we learn that for a continuous time linear model with Gaussian noise, there exists a unique choice of parameters in a linear reduced model for the slow variables which gives the optimal filtering when only the slow variables are observed. Moreover, these parameters simultaneously give the optimal equilibrium statistical estimates of the underlying system, and as a consequence they can be estimated offline from the equilibrium statistics of the true signal. By examining a nonlinear test model, we show that the linear theory extends in this non-Gaussian, nonlinear configuration as long as we know the optimal stochastic parametrization and the correct observation model. However, when the stochastic parametrization model is inappropriate, parameters chosen for good filter performance may give poor equilibrium statistical estimates and vice versa; this finding is based on analytical and numerical results on our nonlinear test model and the two-layer Lorenz-96 model. Finally, even when the correct stochastic ansatz is given, it is imperative to estimate the parameters simultaneously and to account for the nonlinear feedback of the stochastic parameters into the reduced filter estimates. In numerical experiments on the two-layer Lorenz-96 model, we find that the parameters estimated online , as part of a filtering

Ceramic fiber reinforced filter

Science.gov (United States)

Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

1991-01-01

A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

Design of HTS filter for GSM-R communication system

Science.gov (United States)

Cui, Hongyu; Ji, Laiyun

2018-04-01

High-temperature superconducting materials with its excellent performance have increasingly been valued by industries, especially in the field of electronic information. The superconducting material has almost zero surface resistance, and the filter made of it has the characteristics of low insertion loss, high edge steepness and good out-of-band rejection. It has higher selectivity for the desired signal and thus less interference from adjacent channels Signal interference, and noise reduction coefficient can improve the ability to detect weak signals. This design is suitable for high temperature superconducting filter of GSM-R communication system, which can overcome many shortcomings of the traditional GSM-R. The filter is made of DyBCO, a high temperature superconducting thin film material based on magnesium oxide (MgO) substrate with the dielectric constant of 9.7, the center frequency at 887.5MHz, bandwidth of 5MHz.

Software Sub-system in Loading Automatic Test System for the Measurement of Power Line Filters

Directory of Open Access Journals (Sweden)

Yu Bo

2017-01-01

Full Text Available The loading automatic test system for measurement of power line filters are in urgent demand. So the software sub-system of the whole test system was proposed. Methods: structured the test system based on the virtual instrument framework, which consisted of lower and up computer and adopted the top down approach of design to perform the system and its modules, according to the measurement principle of the test system. Results: The software sub-system including human machine interface, data analysis and process software, expert system, communication software, control software in lower computer, etc. had been designed. Furthermore, it had been integrated into the entire test system. Conclusion: This sub-system provided a fiendly software platform for the whole test system, and had many advantages such as strong functions, high performances, low prices. It not only raises the test efficiency of EMI filters, but also renders some creativities.

Voice preprocessing system incorporating a real-time spectrum analyzer with programmable switched-capacitor filters

Science.gov (United States)

Knapp, G.

1984-01-01

As part of a speaker verification program for BISS (Base Installation Security System), a test system is being designed with a flexible preprocessing system for the evaluation of voice spectrum/verification algorithm related problems. The main part of this report covers the design, construction, and testing of a voice analyzer with 16 integrating real-time frequency channels ranging from 300 Hz to 3 KHz. The bandpass filter response of each channel is programmable by NMOS switched capacitor quad filter arrays. Presently, the accuracy of these units is limited to a moderate precision by the finite steps of programming. However, repeatability of characteristics between filter units and sections seems to be excellent for the implemented fourth-order Butterworth bandpass responses. We obtained a 0.1 dB linearity error of signal detection and measured a signal-to-noise ratio of approximately 70 dB. The proprocessing system discussed includes preemphasis filter design, gain normalizer design, and data acquisition system design as well as test results.

The dry filter method for passive filtered venting of the containment

International Nuclear Information System (INIS)

Freis, Daniel; Tietsch, Wolfgang; Obenland, Ralf; Kroes, Bert; Martinsteg, Hans

2013-01-01

Filtered Venting is a mitigative emergency measure to protect the containment from pressure failure in case of a severe accident. Filtered vent systems which are based on the Dry Filter Method (DFM) are proven technology, work completely passive, meet all functional requirements and show excellent performance with respect to filter efficiency. With such a system the release of radioactive fission products to the environment can be effectively minimized. Short and long term land contaminations can be avoided. (orig.)

Spatial filtering with photonic crystals

Energy Technology Data Exchange (ETDEWEB)

Maigyte, Lina [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Rambla Sant Nebridi 22, Terrassa 08222 (Spain); Staliunas, Kestutis [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Rambla Sant Nebridi 22, Terrassa 08222 (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, Barcelona 08010 (Spain)

2015-03-15

Photonic crystals are well known for their celebrated photonic band-gaps—the forbidden frequency ranges, for which the light waves cannot propagate through the structure. The frequency (or chromatic) band-gaps of photonic crystals can be utilized for frequency filtering. In analogy to the chromatic band-gaps and the frequency filtering, the angular band-gaps and the angular (spatial) filtering are also possible in photonic crystals. In this article, we review the recent advances of the spatial filtering using the photonic crystals in different propagation regimes and for different geometries. We review the most evident configuration of filtering in Bragg regime (with the back-reflection—i.e., in the configuration with band-gaps) as well as in Laue regime (with forward deflection—i.e., in the configuration without band-gaps). We explore the spatial filtering in crystals with different symmetries, including axisymmetric crystals; we discuss the role of chirping, i.e., the dependence of the longitudinal period along the structure. We also review the experimental techniques to fabricate the photonic crystals and numerical techniques to explore the spatial filtering. Finally, we discuss several implementations of such filters for intracavity spatial filtering.

Adsorption of Chloroform by the Rapid Response System Filter

National Research Council Canada - National Science Library

Karwacki, Christopher

1997-01-01

Adsorption equilibria and dynamic breakthrough data were measured to determine the adsorption capacity and effect of purge air on the desorption of chloroform from activated carbon simulating the Rapid Response System (RRS) filter...

Online event filtering in the JADE data acquisition system

International Nuclear Information System (INIS)

Mills, H.E.

1986-01-01

The data acquisition system developed for the JADE experiment at PETRA, DESY includes the facility to use software to filter out background events. The design, implementation, testing and experience gained are discussed. (orig.)

Performance of a grid connected PV system used as active filter

International Nuclear Information System (INIS)

Calleja, Hugo; Jimenez, Humberto

2004-01-01

In this paper, the performance of a grid connected photovoltaic (PV) system used as an active filter is presented. Its main feature is the capability to compensate the reactive and harmonic currents drawn by nonlinear loads while simultaneously injecting into the grid the maximum power available from the cells. The system can also operate as a stand alone active filter. The system was connected to a 1 kW PV array and tested with the loads typically found in households: small motors, personal computers and electronic ballasts. The results show that the system can correct the power factor to values close to unity for all the cases tested, thereby improving the efficiency of the electric energy supply

Accelerometer North Finding System Based on the Wavelet Packet De-noising Algorithm and Filtering Circuit

Directory of Open Access Journals (Sweden)

LU Yongle

2014-07-01

Full Text Available This paper demonstrates a method and system for north finding with a low-cost piezoelectricity accelerometer based on the Coriolis acceleration principle. The proposed setup is based on the choice of an accelerometer with residual noise of 35 ng•Hz-1/2. The plane of the north finding system is aligned parallel to the local level, which helps to eliminate the effect of plane error. The Coriolis acceleration caused by the earth’s rotation and the acceleration’s instantaneous velocity is much weaker than the g-sensitivity acceleration. To get a high accuracy and a shorter time for north finding system, in this paper, the Filtering Circuit and the wavelet packet de-nosing algorithm are used as the following. First, the hardware is designed as the alternating currents across by filtering circuit, so the DC will be isolated and the weak AC signal will be amplified. The DC is interfering signal generated by the earth's gravity. Then, we have used a wavelet packet to filter the signal which has been done through the filtering circuit. Finally, compare the north finding results measured by wavelet packet filtering with those measured by a low-pass filter. Wavelet filter de-noise data shows that wavelet packet filtering and wavelet filter measurement have high accuracy. Wavelet Packet filtering has stronger ability to remove burst noise and higher engineering environment adaptability than that of Wavelet filtering. Experimental results prove the effectiveness and project implementation of the accelerometer north finding method based on wavelet packet de-noising algorithm.

Summary of in-situ tests of filter systems in nuclear power stations

International Nuclear Information System (INIS)

Hesboel, R.; Persson, M.

1980-04-01

Iodine filter installations at nuclear power plants are systematically tested regarding light assembly and retention of iodine. Studsvik Energiteknik AB has collected a sizeable amount of test data over the years. The filter installations and test methods are described, followed by an analysis of test results and experience over the past 10 years. As a rule in-situ tests have been carried out at low relative humidity, in 90% of them below 50% relative humidity. Variations in flow have been larger than expected, and the variations in operative conditions affect test results. The test method is, however, regarded acceptable for off-gas filter systems. Additional test methods are required for the auxiliary and energency systems. (G.B.)

Development of the advanced package system for miscellaneous LLW

International Nuclear Information System (INIS)

Miyamoto, K.

1991-01-01

Miscellaneous LLW (low-level radioactive miscellaneous solid wastes) such as parts of machines, pieces of piping, HEPA filter, incineration ashes from nuclear power plants will be disposed in shallow land after stuffing into 200 liter steel drums. The package system of these miscellaneous LLW is required to contain such radionuclides as 14 C, 137 Cs and etc. for a few hundred years. The advanced package system for miscellaneous LLW has been developed. This package system is composed of steel drums with resin mortar inner liner and non shrinkage fills with high flowability. Resin mortar liners have stronger water permeability resistance and higher compressive strength than other cement mortars. Strong water permeability resistance of resin mortar liners prevent underground water from infiltration into fills and solid wastes. On the other hand, as the high flowabilities and non shrinkage of this fills give very low gross void fraction of the package system and have strong adsorption ability of radionuclides. In addition, steel drums with resin mortar inner liners have merits in their high density, uniformity and simplicity in manufacturing. Consequently, this package system is promising candidate barrier for the containment of radionuclides from miscellaneous LLW. (J.P.N.)

Noise filtering in a multi-channel system using a tunable liquid crystal photonic bandgap fiber

DEFF Research Database (Denmark)

Petersen, Martin Nordal; Scolari, Lara; Tokle, Torger

2008-01-01

This paper reports on the first application of a liquid crystal infiltrated photonic bandgap fiber used as a tunable filter in an optical transmission system. The device allows low-cost amplified spontaneous emission (ASE) noise filtering and gain equalization with low insertion loss and broad...... tunability. System experiments show that the use of this filter increases for times the distance over which the optical signal-to-noise ratio (OSNR) is sufficient for error-free transmission with respect to the case in which no filtering is used....

Design, control, and implementation of LCL-filter-based shunt active power filters

DEFF Research Database (Denmark)

Tang, Yi; Loh, Poh Chiang; Wang, Peng

2011-01-01

This paper concentrates on the design, control and implementation of an LCL-filter-based shunt active power filter (SAPF), which can effectively compensate harmonic currents produced by nonlinear loads in a three-phase three-wire power system. The use of LCL-filter at the output end of SAPF offer......-loop control system, and active damping implemented with fewer current sensors are all addressed here. An analytical design example is finally presented, being supported with experimental results, to verify its effectiveness and practicality.......This paper concentrates on the design, control and implementation of an LCL-filter-based shunt active power filter (SAPF), which can effectively compensate harmonic currents produced by nonlinear loads in a three-phase three-wire power system. The use of LCL-filter at the output end of SAPF offers...

Denali, Tulip, and Option Inferior Vena Cava Filter Retrieval: A Single Center Experience.

Science.gov (United States)

Ramaswamy, Raja S; Jun, Emily; van Beek, Darren; Mani, Naganathan; Salter, Amber; Kim, Seung K; Akinwande, Olaguoke

2018-04-01

To compare the technical success of filter retrieval in Denali, Tulip, and Option inferior vena cava filters. A retrospective analysis of Denali, Gunther Tulip, and Option IVC filters was conducted. Retrieval failure rates, fluoroscopy time, sedation time, use of advanced retrieval techniques, and filter-related complications that led to retrieval failure were recorded. There were 107 Denali, 43 Option, and 39 Tulip filters deployed and removed with average dwell times of 93.5, 86.0, and 131 days, respectively. Retrieval failure rates were 0.9% for Denali, 11.6% for Option, and 5.1% for Tulip filters (Denali vs. Option p = 0.018; Denali vs. Tulip p = 0.159; Tulip vs. Option p = 0.045). Median fluoroscopy time for filter retrieval was 3.2 min for the Denali filter, 6.75 min for the Option filter, and 4.95 min for the Tulip filter (Denali vs. Option p Option p = 0.67). Advanced retrieval techniques were used in 0.9% of Denali filters, 21.1% in Option filters, and 10.8% in Tulip filters (Denali vs. Option p Option p Option filter when compared to both the Denali and Tulip filters. Retrieval of the Denali filter required significantly less amount of fluoroscopy time and use of advanced retrieval techniques when compared to both the Option and Tulip filters. The findings of this study indicate easier retrieval of the Denali and Tulip IVC filters when compared to the Option filter.

An iterated cubature unscented Kalman filter for large-DoF systems identification with noisy data

Science.gov (United States)

Ghorbani, Esmaeil; Cha, Young-Jin

2018-04-01

Structural and mechanical system identification under dynamic loading has been an important research topic over the last three or four decades. Many Kalman-filtering-based approaches have been developed for linear and nonlinear systems. For example, to predict nonlinear systems, an unscented Kalman filter was applied. However, from extensive literature reviews, the unscented Kalman filter still showed weak performance on systems with large degrees of freedom. In this research, a modified unscented Kalman filter is proposed by integration of a cubature Kalman filter to improve the system identification performance of systems with large degrees of freedom. The novelty of this work lies on conjugating the unscented transform with the cubature integration concept to find a more accurate output from the transformation of the state vector and its related covariance matrix. To evaluate the proposed method, three different numerical models (i.e., the single degree-of-freedom Bouc-Wen model, the linear 3-degrees-of-freedom system, and the 10-degrees-of-freedom system) are investigated. To evaluate the robustness of the proposed method, high levels of noise in the measured response data are considered. The results show that the proposed method is significantly superior to the traditional UKF for noisy measured data in systems with large degrees of freedom.

Robust extended Kalman filter of discrete-time Markovian jump nonlinear system under uncertain noise

International Nuclear Information System (INIS)

Zhu, Jin; Park, Jun Hong; Lee, Kwan Soo; Spiryagin, Maksym

2008-01-01

This paper examines the problem of robust extended Kalman filter design for discrete -time Markovian jump nonlinear systems with noise uncertainty. Because of the existence of stochastic Markovian switching, the state and measurement equations of underlying system are subject to uncertain noise whose covariance matrices are time-varying or un-measurable instead of stationary. First, based on the expression of filtering performance deviation, admissible uncertainty of noise covariance matrix is given. Secondly, two forms of noise uncertainty are taken into account: Non- Structural and Structural. It is proved by applying game theory that this filter design is a robust mini-max filter. A numerical example shows the validity of the method

DNA accumulation on ventilation system filters in university buildings in Singapore.

Science.gov (United States)

Luhung, Irvan; Wu, Yan; Xu, Siyu; Yamamoto, Naomichi; Chang, Victor Wei-Chung; Nazaroff, William W

2017-01-01

Biological particles deposit on air handling system filters as they process air. This study reports and interprets abundance and diversity information regarding biomass accumulation on ordinarily used filters acquired from several locations in a university environment. DNA-based analysis was applied both to quantify (via DNA fluorometry and qPCR) and to characterize (via high-throughput sequencing) the microbial material on filters, which mainly processed recirculated indoor air. Results were interpreted in relation to building occupancy and ventilation system operational parameters. Based on accumulated biomass, average DNA concentrations per AHU filter surface area across nine indoor locations after twelve weeks of filter use were in the respective ranges 1.1 to 41 ng per cm2 for total DNA, 0.02 to 3.3 ng per cm2 for bacterial DNA and 0.2 to 2.0 ng DNA per cm2 for fungal DNA. The most abundant genera detected on the AHU filter samples were Clostridium, Streptophyta, Bacillus, Acinetobacter and Ktedonobacter for bacteria and Aspergillus, Cladosporium, Nigrospora, Rigidoporus and Lentinus for fungi. Conditional indoor airborne DNA concentrations (median (range)) were estimated to be 13 (2.6-107) pg/m3 for total DNA, 0.4 (0.05-8.4) pg/m3 for bacterial DNA and 2.3 (1.0-5.1) pg/m3 for fungal DNA. Conditional airborne concentrations and the relative abundances of selected groups of genera correlate well with occupancy level. Bacterial DNA was found to be more responsive than fungal DNA to differences in occupancy level and indoor environmental conditions.

A practical approach to harmonic compensation in power systems-series connection of passive and active filters

OpenAIRE

Fujita, Hideaki; Akagi, Hirofumi

1991-01-01

The authors present a combined system with a passive filter and a small-rated active filter, both connected in series with each other. The passive filter removes load produced harmonics just as a conventional filter does. The active filter plays a role in improving the filtering characteristics of the passive filter. This results in a great reduction of the required rating of the active filter and in eliminating all the limitations faced by using only the passive filter, leading to a practica...

Iodine filter imaging system for subtraction angiography using synchrotron radiation

Science.gov (United States)

Umetani, K.; Ueda, K.; Takeda, T.; Itai, Y.; Akisada, M.; Nakajima, T.

1993-11-01

A new type of real-time imaging system was developed for transvenous coronary angiography. A combination of an iodine filter and a single energy broad-bandwidth X-ray produces two-energy images for the iodine K-edge subtraction technique. X-ray images are sequentially converted to visible images by an X-ray image intensifier. By synchronizing the timing of the movement of the iodine filter into and out of the X-ray beam, two output images of the image intensifier are focused side by side on the photoconductive layer of a camera tube by an oscillating mirror. Both images are read out by electron beam scanning of a 1050-scanning-line video camera within a camera frame time of 66.7 ms. One hundred ninety two pairs of iodine-filtered and non-iodine-filtered images are stored in the frame memory at a rate of 15 pairs/s. In vivo subtracted images of coronary arteries in dogs were obtained in the form of motion pictures.

A multi-standard active-RC filter with accurate tuning system

Energy Technology Data Exchange (ETDEWEB)

Ma Heping; Yuan Fang; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Dai, F F, E-mail: hpma@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

2009-09-15

A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 {mu}m 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm{sup 2} and 0.11 mm{sup 2} (calibration circuit excluded), respectively.

NASA Advanced Exploration Systems: Advancements in Life Support Systems

Science.gov (United States)

Shull, Sarah A.; Schneider, Walter F.

2016-01-01

The NASA Advanced Exploration Systems (AES) Life Support Systems (LSS) project strives to develop reliable, energy-efficient, and low-mass spacecraft systems to provide environmental control and life support systems (ECLSS) critical to enabling long duration human missions beyond low Earth orbit (LEO). Highly reliable, closed-loop life support systems are among the capabilities required for the longer duration human space exploration missions assessed by NASA’s Habitability Architecture Team.

Finite-Time H∞ Filtering for Linear Continuous Time-Varying Systems with Uncertain Observations

Directory of Open Access Journals (Sweden)

Huihong Zhao

2012-01-01

Full Text Available This paper is concerned with the finite-time H∞ filtering problem for linear continuous time-varying systems with uncertain observations and ℒ2-norm bounded noise. The design of finite-time H∞ filter is equivalent to the problem that a certain indefinite quadratic form has a minimum and the filter is such that the minimum is positive. The quadratic form is related to a Krein state-space model according to the Krein space linear estimation theory. By using the projection theory in Krein space, the finite-time H∞ filtering problem is solved. A numerical example is given to illustrate the performance of the H∞ filter.

Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

DEFF Research Database (Denmark)

Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

2015-01-01

Unintentional series and/or parallel resonances, due to the tuned passive filter and the line inductance, may result in severe harmonic distortion in the industrial power system. This paper presents a hybrid active filter to suppress harmonic resonance and reduce harmonic distortion as well...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

Science.gov (United States)

Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

2018-07-01

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

Filter assembly for metallic and intermetallic tube filters

Science.gov (United States)

Alvin, Mary Anne; Lippert, Thomas E.; Bruck, Gerald J.; Smeltzer, Eugene E.

2001-01-01

A filter assembly (60) for holding a filter element (28) within a hot gas cleanup system pressure vessel is provided, containing: a filter housing (62), said filter housing having a certain axial length and having a peripheral sidewall, said sidewall defining an interior chamber (66); a one piece, all metal, fail-safe/regenerator device (68) within the interior chamber (66) of the filter housing (62) and/or extending beyond the axial length of the filter housing, said device containing an outward extending radial flange (71) within the filter housing for seating an essential seal (70), the device also having heat transfer media (72) disposed inside and screens (80) for particulate removal; one compliant gasket (70) positioned next to and above the outward extending radial flange of the fail-safe/regenerator device; and a porous metallic corrosion resistant superalloy type filter element body welded at the bottom of the metal fail-safe/regenerator device.

Numerical study of canister filters with alternatives filter cap configurations

Science.gov (United States)

Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

2017-09-01

Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Science.gov (United States)

2010-07-01

... effluent turbidity limits must my system meet? 141.551 Section 141.551 Protection of Environment... Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system meet? Your system must meet two strengthened combined filter effluent turbidity limits. (a) The first...

Kalman Filtering for Discrete Stochastic Systems with Multiplicative Noises and Random Two-Step Sensor Delays

Directory of Open Access Journals (Sweden)

Dongyan Chen

2015-01-01

Full Text Available This paper is concerned with the optimal Kalman filtering problem for a class of discrete stochastic systems with multiplicative noises and random two-step sensor delays. Three Bernoulli distributed random variables with known conditional probabilities are introduced to characterize the phenomena of the random two-step sensor delays which may happen during the data transmission. By using the state augmentation approach and innovation analysis technique, an optimal Kalman filter is constructed for the augmented system in the sense of the minimum mean square error (MMSE. Subsequently, the optimal Kalman filtering is derived for corresponding augmented system in initial instants. Finally, a simulation example is provided to demonstrate the feasibility and effectiveness of the proposed filtering method.

Advanced intelligent systems

CERN Document Server

Ryoo, Young; Jang, Moon-soo; Bae, Young-Chul

2014-01-01

Intelligent systems have been initiated with the attempt to imitate the human brain. People wish to let machines perform intelligent works. Many techniques of intelligent systems are based on artificial intelligence. According to changing and novel requirements, the advanced intelligent systems cover a wide spectrum: big data processing, intelligent control, advanced robotics, artificial intelligence and machine learning. This book focuses on coordinating intelligent systems with highly integrated and foundationally functional components. The book consists of 19 contributions that features social network-based recommender systems, application of fuzzy enforcement, energy visualization, ultrasonic muscular thickness measurement, regional analysis and predictive modeling, analysis of 3D polygon data, blood pressure estimation system, fuzzy human model, fuzzy ultrasonic imaging method, ultrasonic mobile smart technology, pseudo-normal image synthesis, subspace classifier, mobile object tracking, standing-up moti...

DESIGN AND FABRICATION OF MULTI STAGE CUTTING OIL FILTER SYSTEM

OpenAIRE

ABHIJIT S. GETME , ADITENDRA JAISWAL

2018-01-01

Multistage oil filtration system is a system used to filter out all the metallic, non metallic particles from the cutting fluid, which is used during the machining processes. Basic procedures we are using in it are: centrifugal process, magnetic filtration, paper filtration.

A New Class of Particle Filters for Random Dynamic Systems with Unknown Statistics

Directory of Open Access Journals (Sweden)

Joaquín Míguez

2004-11-01

Full Text Available In recent years, particle filtering has become a powerful tool for tracking signals and time-varying parameters of random dynamic systems. These methods require a mathematical representation of the dynamics of the system evolution, together with assumptions of probabilistic models. In this paper, we present a new class of particle filtering methods that do not assume explicit mathematical forms of the probability distributions of the noise in the system. As a consequence, the proposed techniques are simpler, more robust, and more flexible than standard particle filters. Apart from the theoretical development of specific methods in the new class, we provide computer simulation results that demonstrate the performance of the algorithms in the problem of autonomous positioning of a vehicle in a 2-dimensional space.

Optical filtering in directly modulated/detected OOFDM systems.

Science.gov (United States)

Sánchez, C; Ortega, B; Wei, J L; Capmany, J

2013-12-16

This work presents a theoretical investigation on the performance of directly modulated/detected (DM/DD) optical orthogonal frequency division multiplexed (OOFDM) systems subject to optical filtering. The impact of both linear and nonlinear distortion effects are taken into account to calculate the effective signal-to-noise ratio of each subcarrier. These results are then employed to optimize the design parameters of two simple optical filtering structures: a Mach Zehnder interferometer and a uniform fiber Bragg grating, leading to a significant optical power budget improvement given by 3.3 and 3dB, respectively. These can be further increased to 5.5 and 4.2dB respectively when balanced detection configurations are employed. We find as well that this improvement is highly dependent on the clipping ratio.

Dynamic data filtering system and method

Science.gov (United States)

Bickford, Randall L; Palnitkar, Rahul M

2014-04-29

A computer-implemented dynamic data filtering system and method for selectively choosing operating data of a monitored asset that modifies or expands a learned scope of an empirical model of normal operation of the monitored asset while simultaneously rejecting operating data of the monitored asset that is indicative of excessive degradation or impending failure of the monitored asset, and utilizing the selectively chosen data for adaptively recalibrating the empirical model to more accurately monitor asset aging changes or operating condition changes of the monitored asset.

Design and Simulation of a T-Type Lymphocyte Cells Filter on a Microfluidic System

Directory of Open Access Journals (Sweden)

Daniel A. Quiroga T.

2016-01-01

Full Text Available This work consisted in designing and validating, by experimental computational simulation, a T-Lymphocites filtering system based on microfluidics for hiv virus detection. Material and methods: It was used AutoDesk® Inventor simulation tool was used with which the microflui­dic system design was performed. The filter system was tested by a computer simulation in the AutoDesk® Simulation cfd (computational fluid dynamics software, simulation tool in which different particles with different diameters (5 μm, 10 μm, 15 μm flow through the system to test. Results and conclusions: Results showed that this system allowed to pass the expected particles, however, it also was observed that it allows bigger particles than desired, for this reason it is neces­sary to keep on working on system perfectioning. Filtering system efficiency was of a 33.33 %.

Heating without heat: Thermodynamics of passive energy filters between finite systems.

Science.gov (United States)

Muñoz-Tapia, R; Brito, R; Parrondo, J M R

2017-09-01

Passive filters allowing the exchange of particles in a narrow band of energy are currently used in microrefrigerators and energy transducers. In this Rapid Communication, we analyze their thermal properties using linear irreversible thermodynamics and kinetic theory, and discuss a striking phenomenon: the possibility of simultaneously increasing or decreasing the temperatures of two systems without any supply of energy. This occurs when the filter induces a flow of particles whose energy is between the average energies of the two systems. Here we show that this selective transfer of particles does not need the action of any sort of Maxwell demon and can be carried out by passive filters without compromising the second law of thermodynamics. This phenomenon allows us to design cycles between two reservoirs at temperatures T_{1}

Grid-Connected Photovoltaic System with Active Power Filtering Functionality

Directory of Open Access Journals (Sweden)

Joaquín Vaquero

2018-01-01

Full Text Available Solar panels are an attractive and growing source of renewable energy in commercial and residential applications. Its use connected to the grid by means of a power converter results in a grid-connected photovoltaic system. In order to optimize this system, it is interesting to integrate several functionalities into the power converter, such as active power filtering and power factor correction. Nonlinear loads connected to the grid generate current harmonics, which deteriorates the mains power quality. Active power filters can compensate these current harmonics. A photovoltaic system with added harmonic compensation and power factor correction capabilities is proposed in this paper. A sliding mode controller is employed to control the power converter, implemented on the CompactRIO digital platform from National Instruments Corporation, allowing user friendly operation and easy tuning. The power system consists of two stages, a DC/DC boost converter and a single-phase inverter, and it is able to inject active power into the grid while compensating the current harmonics generated by nonlinear loads at the point of common coupling. The operation, design, simulation, and experimental results for the proposed system are discussed.

Fast filtering algorithm based on vibration systems and neural information exchange and its application to micro motion robot

International Nuclear Information System (INIS)

Gao Wa; Zha Fu-Sheng; Li Man-Tian; Song Bao-Yu

2014-01-01

This paper develops a fast filtering algorithm based on vibration systems theory and neural information exchange approach. The characters, including the derivation process and parameter analysis, are discussed and the feasibility and the effectiveness are testified by the filtering performance compared with various filtering methods, such as the fast wavelet transform algorithm, the particle filtering method and our previously developed single degree of freedom vibration system filtering algorithm, according to simulation and practical approaches. Meanwhile, the comparisons indicate that a significant advantage of the proposed fast filtering algorithm is its extremely fast filtering speed with good filtering performance. Further, the developed fast filtering algorithm is applied to the navigation and positioning system of the micro motion robot, which is a high real-time requirement for the signals preprocessing. Then, the preprocessing data is used to estimate the heading angle error and the attitude angle error of the micro motion robot. The estimation experiments illustrate the high practicality of the proposed fast filtering algorithm. (general)

Perspectives on Nonlinear Filtering

KAUST Repository

Law, Kody

2015-01-01

The solution to the problem of nonlinear filtering may be given either as an estimate of the signal (and ideally some measure of concentration), or as a full posterior distribution. Similarly, one may evaluate the fidelity of the filter either by its ability to track the signal or its proximity to the posterior filtering distribution. Hence, the field enjoys a lively symbiosis between probability and control theory, and there are plenty of applications which benefit from algorithmic advances, from signal processing, to econometrics, to large-scale ocean, atmosphere, and climate modeling. This talk will survey some recent theoretical results involving accurate signal tracking with noise-free (degenerate) dynamics in high-dimensions (infinite, in principle, but say d between 103 and 108 , depending on the size of your application and your computer), and high-fidelity approximations of the filtering distribution in low dimensions (say d between 1 and several 10s).

Perspectives on Nonlinear Filtering

KAUST Repository

Law, Kody

2015-01-07

The solution to the problem of nonlinear filtering may be given either as an estimate of the signal (and ideally some measure of concentration), or as a full posterior distribution. Similarly, one may evaluate the fidelity of the filter either by its ability to track the signal or its proximity to the posterior filtering distribution. Hence, the field enjoys a lively symbiosis between probability and control theory, and there are plenty of applications which benefit from algorithmic advances, from signal processing, to econometrics, to large-scale ocean, atmosphere, and climate modeling. This talk will survey some recent theoretical results involving accurate signal tracking with noise-free (degenerate) dynamics in high-dimensions (infinite, in principle, but say d between 103 and 108 , depending on the size of your application and your computer), and high-fidelity approximations of the filtering distribution in low dimensions (say d between 1 and several 10s).

Kalman Filtering with Real-Time Applications

CERN Document Server

Chui, Charles K

2009-01-01

Kalman Filtering with Real-Time Applications presents a thorough discussion of the mathematical theory and computational schemes of Kalman filtering. The filtering algorithms are derived via different approaches, including a direct method consisting of a series of elementary steps, and an indirect method based on innovation projection. Other topics include Kalman filtering for systems with correlated noise or colored noise, limiting Kalman filtering for time-invariant systems, extended Kalman filtering for nonlinear systems, interval Kalman filtering for uncertain systems, and wavelet Kalman filtering for multiresolution analysis of random signals. Most filtering algorithms are illustrated by using simplified radar tracking examples. The style of the book is informal, and the mathematics is elementary but rigorous. The text is self-contained, suitable for self-study, and accessible to all readers with a minimum knowledge of linear algebra, probability theory, and system engineering.

Backflushable filter insert

International Nuclear Information System (INIS)

Keith, R.C.; Vandenberg, T.; Randolph, M.C.; Lewis, T.B.; Gillis, P.J. Jr.

1988-01-01

Filter elements are mounted on a tube plate beneath an accumulator chamber whose wall is extended by skirt and flange to form a closure for the top of pressure vessel. The accumulator chamber is annular around a central pipe which serves as the outlet for filtered water passing from the filter elements. The chamber contains filtered compressed air from supply. Periodically the filtration of water is stopped and vessel is drained. Then a valve is opened, allowing the accumulated air to flow from chamber up a pipe and down pipe, pushing the filtered water from pipe back through the filter elements to clean them. The accumulator chamber is so proportioned, relative to the volume of the system communicating therewith during backflushing, that the equilibrium pressure during backflushing cannot exceed the pressure rating of the vessel. However a line monitors the pressure at the top of the vessel, and if it rises too far a bleed valve is automatically opened to depressurise the system. The chamber is intended to replace the lid of an existing vessel to convert a filter using filter aid to one using permanent filter elements. (author)

Advanced Worker Protection System

International Nuclear Information System (INIS)

1996-04-01

The Advanced Worker Protection System (AWPS) is a liquid-air-based, self-contained breathing and cooling system with a duration of 2 hrs. AWPS employs a patented system developed by Oceaneering Space Systems (OSS), and was demonstrated at their facility in Houston, TX as well as at Kansas State University, Manhattan. The heart of the system is the life-support backpack that uses liquid air to provide cooling as well as breathing gas to the worker. The backpack is combined with advanced protective garments, an advanced liquid cooling garment (LCG), a respirator, and communications and support equipment. The prototype unit development and testing under Phase 1 has demonstrated that AWPS has the ability to meet performance criteria. These criteria were developed with an understanding of both the AWPS capabilities and the DOE decontamination and decommissioning (D and D) activities protection needs

A model for transient analysis of a multiple-medium confinement filter system

International Nuclear Information System (INIS)

Hyder, M.L.; Ellison, P.G.; Leonard, M.T.; Louie, D.L.Y.; Donbroski, E.L.; Wagner, K.C.

1990-01-01

A computational model is described that calculates the transient behavior of aerosol and vapor (adsorption) filter compartments such as those used in the Savannah River Site (SRS) production reactor confinement system. The principal application of the model is in the analysis of confinement response to hypothetical severe (core melt) accidents. Under these conditions, aerosol and radio-iodine deposition on filter compartments may be substantial. Attendant filter degradation mechanisms are modeled. Sample calculations are included to illustrate model performance. 6 refs., 14 figs., 1 tab

Connected Filtering by Reconstruction : Basis and New Advances

NARCIS (Netherlands)

Wilkinson, Michael H.F.

2008-01-01

Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

CONNECTED FILTERING BY RECONSTRUCTION : BASIS AND NEW ADVANCES

NARCIS (Netherlands)

Wilkinson, Michael H. F.

2008-01-01

Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

Beam position feedback system for the advanced photon source

International Nuclear Information System (INIS)

Chung, Y.

1994-01-01

The Advanced Photon Source (APS) will implement both global and local beam position feedback systems to stabilize the particle and x-ray beams for the storage ring. The systems consist of 20 VME crates distributed around the ring, each running multiple digital signal processors (DSP) running at 4 kHz sampling rate with a proportional, integral, and derivative (PID) control algorithm. The particle and x-ray beam position data is shared by the distributed processors through networked reflective memory. A theory of closed orbit correction using the technique of singular value decomposition (SVD) of the response matrix and simulation of its application to the APS storage ring will be discussed. This technique combines the global and local feedback systems and resolves the conflict among multiple local feedback systems due to local bump closure error. Maximum correction efficiency is achieved by feeding back to the global orbit data to the local feedback systems. The effect of the eddy current induced in the relatively thick (1/2 in.) vacuum chamber by the ac corrector magnet field for local feedback systems is compensated by digital filters. Results of experiments conducted on the x-ray ring of the National Synchrotron Light Source and the SPEAR at Stanford Synchrotron Radiation Laboratory will also be presented

Beam position feedback system for the advanced photon source

International Nuclear Information System (INIS)

Chung, Y.

1994-01-01

The Advanced Photon Source (APS) will implement both global and local beam position feedback systems to stabilize the particle and X-ray beams for the storage ring. The systems consist of 20 VME crates distributed around the ring, each running multiple digital signal processors (DSP) running at 4 kHz sampling rate with a proportional, integral, and derivative (PID) control algorithm. The particle and X-ray beam position data is shared by the distributed processors through networked reflective memory. A theory of closed orbit correction using the technique of singular value decomposition (SVD) of the response matrix and simulation of its application to the APS storage ring will be discussed. This technique combines the global and local feedback systems and resolves the conflict among multiple local feedback systems due to local bump closure error. Maximum correction efficiency is achieved by feeding back the global orbit data to the local feedback systems. The effect of the vacuum chamber eddy current induced by the AC corrector magnet field for local feedback systems is compensated by digital filters. Results of experiments conducted on the X-ray ring of the National Synchrotron Light Source and the SPEAR at Stanford Synchrotron Radiation Laboratory will be presented. copyright 1994 American Institute of Physics

Beam position feedback system for the Advanced Photon Source

International Nuclear Information System (INIS)

Chung, Y.

1993-01-01

The Advanced Photon Source (APS) will implement both global and local beam position feedback systems to stabilize the particle and X-ray beams for the storage ring. The systems consist of 20 VME crates distributed around the ring, each running multiple digital signal processors (DSP) running at 4kHz sampling rate with a proportional, integral, and derivative (PID) control algorithm. The particle and X-ray beam position data is shared by the distributed processors through networked reflective memory. A theory of closed orbit correction using the technique of singular value decomposition (SVD) of the response matrix and simulation of its application to the APS storage ring will be discussed. This technique combines the global and local feedback systems and resolves the conflict among multiple local feedback systems due to local bump closure error. Maximum correction efficiency is achieved by feeding back the global orbit data to the local feedback systems. The effect of the vacuum chamber eddy current induced by the AC corrector magnet field for local feedback systems is compensated by digital filters. Results of experiments conducted on the X-ray ring of the National Synchrotron Light Source and the SPEAR at Stanford Synchrotron Radiation Laboratory will be presented

Beam position feedback system for the Advanced Photon Source

International Nuclear Information System (INIS)

Chung, Y.

1993-01-01

The Advanced Photon Source (APS) will implement both global and local beam position feedback systems to stabilize the particle and X-ray beams for the storage ring. The systems consist of 20 VME crates distributed around the ring, each running multiple digital signal processors (DSP) running at 4kHz sampling rate with a proportional, integral, and derivative (PID) control algorithm. The particle and X-ray beam position data is shared by the distributed processors through networked reflective memory. A theory of closed orbit correction using the technique of singular value decomposition (SVD) of the response matrix and simulation of its application to the APS storage ring will be discussed. This technique combines the global and local feedback systems and resolves the conflict among multiple local feedback systems due to local bump closure error. Maximum correction efficiency is achieved by feeding back the global orbit data to the local feedback systems. The effect of the eddy current induced in the relatively thick (1/2 inch) vacuum chamber by the AC corrector magnet field for local feedback systems is compensated by digital filters. Results of experiments conducted on the X-ray ring of the National Synchrotron Light Source and the SPEAR at Stanford Synchrotron Radiation Laboratory will also be presented

A Survey on Distributed Filtering and Fault Detection for Sensor Networks

Directory of Open Access Journals (Sweden)

Hongli Dong

2014-01-01

Full Text Available In recent years, theoretical and practical research on large-scale networked systems has gained an increasing attention from multiple disciplines including engineering, computer science, and mathematics. Lying in the core part of the area are the distributed estimation and fault detection problems that have recently been attracting growing research interests. In particular, an urgent need has arisen to understand the effects of distributed information structures on filtering and fault detection in sensor networks. In this paper, a bibliographical review is provided on distributed filtering and fault detection problems over sensor networks. The algorithms employed to study the distributed filtering and detection problems are categorised and then discussed. In addition, some recent advances on distributed detection problems for faulty sensors and fault events are also summarized in great detail. Finally, we conclude the paper by outlining future research challenges for distributed filtering and fault detection for sensor networks.

Rotation speed measurement for turbine governor: torsion filtering by using Kalman filter

International Nuclear Information System (INIS)

Houry, M.P.; Bourles, H.

1996-01-01

The rotation speed of a turbogenerator is disturbed by its shaft torsion. Obtaining a filtered measure of this speed is a problem of a great practical importance for turbine governor. A good filtering of this speed must meet two requirements: it must cut frequencies of the shaft torsion oscillation and it must not reduce or delay the signal in the pass-band, i.e. at lower frequencies. At Electricite de France, the speed measure is used to set in motion the fast valving system as quickly as possible, after a short circuit close to the unit or rather an islanding. It is difficult to satisfy these two requirements by using conventional filtering methods. The standard solution consists in a first order filter: at Electricite de France, its time constant is equal to 80 ms. We have decided to improve this filtering by designing a new filter which cuts the frequencies of the shaft torsion oscillation without reducing the bandwidth to the speed measure. If one uses conventional methods to obtain a band stop filter, it is easy to obtain the desired magnitude but not a phase near zero in the whole pass-band. Therefore, we have chosen to design the filter by using Kalman'a theory. The measurement noise is modeled as a colored one, generated by a very lightly damped system driven by a while noise. The resulting Kalman filter is an effective band stop filter, whose phase nicely remains near zero in the whole pass-band. The digital simulations we made and the tests we carried out with the Electricite de France Micro Network laboratory show the advantages of the rotation speed filter we designed using Kalman's theory. With the proposed filter, the speed measure filtering is better in terms of reduction and phase shift. the result is that there are less untimely solicitations of the fast valving system. Consequently, this device improves the power systems stability by minimizing the risks of deep perturbations due to a temporary lack of generation and the risks of under-speed loss

Dust characterisation for hot gas filters

Energy Technology Data Exchange (ETDEWEB)

Dockter, B.; Erickson, T.; Henderson, A.; Hurley, J.; Kuehnel, V.; Katrinak, K.; Nowok, J.; O`Keefe, C.; O`Leary, E.; Swanson, M.; Watne, T. [University of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center (UNDEERC)

1998-03-01

Hot gas filtration to remove particulates from the gas flow upstream of the gas turbine is critical to the development of many of the advanced coal-fired power generation technologies such as the Air Blown Gasification Cycle (ABGC), a hybrid gasification combined cycle being developed in the UK. Ceramic candle filters are considered the most promising technology for this purpose. Problems of mechanical failure and of `difficult-to-clean` dusts causing high pressure losses across the filter elements need to be solved. The project investigated the behaviour of high-temperature filter dusts, and the factors determining the ease with which they can be removed from filters. The high-temperature behaviour of dusts from both combustion and gasification systems was investigated. Dust samples were obtained from full-scale demonstration and pilot-scale plant operating around the world. Dust samples were also produced from a variety of coals, and under several different operating conditions, on UNDEERC`s pilot-scale reactor. Key factors affecting dust behaviour were examined, including: the rates of tensile strength developing in dust cakes; the thermochemical equilibria pertaining under filtration conditions; dust adhesivity on representative filter materials; and the build-up and cleaning behaviour of dusts on representative filter candles. The results obtained confirmed the importance of dust temperature, dust cake porosity, cake liquid content, and particle size distribution in determining the strength of a dust cake. An algorithm was developed to indicate the likely sticking propensity of dusts as a function of coal and sorbent composition and combustion conditions. This algorithm was incorporated into a computer package which can be used to judge the degree of difficulty in filter cleaning that can be expected to arise in a real plant based on operating parameters and coal analyzes. 6 figs.

FULL SCALE REGENERABLE HEPA FILTER DESIGN USING SINTERED METAL FILTER ELEMENTS

International Nuclear Information System (INIS)

Gil Ramos; Kenneth Rubow; Ronald Sekellick

2002-01-01

A Department of Energy funded contract involved the development of porous metal as a HEPA filter, and the subsequent design of a full-scale regenerable HEPA filtration system (RHFS). This RHFS could replace the glass fiber HEPA filters currently being used on the high level waste (HLW) tank ventilation system with a system that would be moisture tolerant, durable, and cleanable in place. The origins of the contract are a 1996 investigation at the Savannah River Technology Center (SRTC) regarding the use of porous metal as a HEPA filter material. This contract was divided into Phases I, IIA and IIB. Phase I of the contract evaluated simple filter cylinders in a simulated High Level Waste (HLW) environment and the ability to clean and regenerate the filter media after fouling. Upon the successful completion of Phase I, Phase IIA was conducted, which included lab scale prototype testing and design of a full-scale system. The work completed under Phase IIA included development of a full-scale system design, development of a filter media meeting the HEPA filtration efficiency that would also be regenerable using prescribed cleaning procedures, and the testing of a single element system prototype at Savannah River. All contract objectives were met. The filter media selected was a nickel material already under development at Mott, which met the HEPA filtration efficiency standard. The Mott nickel media met and exceeded the HEPA requirement, providing 99.99% removal against a requirement of 99.97%. Double open-ended elements of this media were provided to the Savannah River Test Center for HLW simulation testing in the single element prototype filter. These elements performed well and further demonstrated the practicality of a metallic media regenerable HEPA filter system. An evaluation of the manufacturing method on many elements demonstrated the reproducibility to meet the HEPA filtration requirement. The full-scale design of the Mott RHFS incorporated several important

System of the sensor failure detection and isolation system using Kalman filter

International Nuclear Information System (INIS)

Assumpcao Filho, E.O.; Nakata, H.

1991-01-01

The present work work summarizes the development of the sensor failure detection and isolation system (FDIS) suitable to be implemented in nuclear plant control systems. The methodology is based on the extended Kalman filter applied to a PWR pressurizer simplified model. The simulation of the most representative failure types showed the great reliability and fast response capability of the FDIS developed allowing the sizable savings in computational and economic expenditures. (author)

Numerical Study on Self-Cleaning Canister Filter With Add-On Filter Cap

Directory of Open Access Journals (Sweden)

Mohammed Akmal Nizam

2017-01-01

Full Text Available Filtration in a turbo machinery system such as a gas turbine will ensure that the air entering the inlet is free from contaminants that could bring damage to the main system. Self-cleaning filter systems for gas turbines are designed for continuously efficient flow filtration. A good filter would be able to maintain its effectiveness over a longer time period, prolonging the duration between filter replacements and providing lower pressure drop over its operating lifetime. With this goal in mind, the current study is focused on the difference in pressure loss of the benchmark Salutary Avenue Self-cleaning filter in comparison to a new design with an add-on filter cap. Geometry for the add-on filter cap will be based from Salutary Avenue Manufacturing Sdn.Bhd. SOLIDWORKS software was used to model the geometry of the filter, while simulation analysis on the flow through the filter was done using Computational Fluid Dynamic (CFD software. The simulations are based on a low velocity condition, in which the parameter for the inlet velocity are set at 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s respectively. From the simulation data obtained for the inlet velocities considered, the pressure drop reduction of the modified filter compared to the benchmark was found to be between 7.59% and 30.18%. All in all, the modification of the filter cap produced a lower pressure drop in comparison with the benchmark filter; an improvement of 27.02% for the total pressure drop was obtained.

Logistics Reduction: Advanced Clothing System (ACS)

Data.gov (United States)

National Aeronautics and Space Administration — The goal of the Advanced Exploration System (AES) Logistics Reduction (LR) project's Advanced Clothing System (ACS) is to use advanced commercial off-the-shelf...

Distributed Systems and Applications of Information Filtering and Retrieval

CERN Document Server

Giuliani, Alessandro; Semeraro, Giovanni; DART 2012

2014-01-01

This volume focuses on new challenges in distributed Information Filtering and Retrieval. It collects invited chapters and extended research contributions from the special session on Information Filtering and Retrieval: Novel Distributed Systems and Applications (DART) of the 4th International Conference on Knowledge Discovery and Information Retrieval (KDIR 2012), held in Barcelona, Spain, on 4-7 October 2012. The main focus of DART was to discuss and compare suitable novel solutions based on intelligent techniques and applied to real-world applications. The chapters of this book present a comprehensive review of related works and state of the art. Authors, both practitioners and researchers, shared their results in several topics such as "Multi-Agent Systems", "Natural Language Processing", "Automatic Advertisement", "Customer Interaction Analytics", "Opinion Mining". Contributions have been careful reviewed by experts in the area, who also gave useful suggestions to improve the quality of the volume.

A filter circuit board for the Earthworm Seismic Data Acquisition System

Science.gov (United States)

Jensen, Edward Gray

2000-01-01

The Earthworm system is a seismic network data acquisition and processing system used by the Northern California Seismic Network as well as many other seismic networks. The input to the system is comprised of many realtime electronic waveforms fed to a multi-channel digitizer on a PC platform. The digitizer consists of one or more National Instruments Corp. AMUX–64T multiplexer boards attached to an A/D converter board located in the computer. Originally, passive filters were installed on the multiplexers to eliminate electronic noise picked up in cabling. It was later discovered that a small amount of crosstalk occurred between successive channels in the digitizing sequence. Though small, this crosstalk will cause what appear to be small earthquake arrivals at the wrong time on some channels. This can result in erroneous calculation of earthquake arrival times, particularly by automated algorithms. To deal with this problem, an Earthworm filter board was developed to provide the needed filtering while eliminating crosstalk. This report describes the tests performed to find a suitable solution, and the design of the circuit board. Also included are all the details needed to build and install this board in an Earthworm system or any other system using the AMUX–64T board. Available below is the report in PDF format as well as an archive file containing the circuit board manufacturing information.

Method for filtering radon from a gas system

International Nuclear Information System (INIS)

Sowinski, R.F.

1992-01-01

This patent describes a method of filtering, adjacent to an end user-customer's residence, or business in which at least a single gas appliance is located, a natural gas stream in which benz-a-anthracene has been concentrated at sufficient levels to be a health threat in a natural gas gathering and distributing network. It comprises introducing the natural gas stream to a filter selected from a group that includes impingement, passing the filtered natural gas stream to the customer's gas appliance wherein safe use of the energy associated with the stream occurs, periodically and safely removing the filter for disposing of captured benz-a-anthracene, inserting a new filter in place of the removed filter of step

The role of model dynamics in ensemble Kalman filter performance for chaotic systems

Science.gov (United States)

Ng, G.-H.C.; McLaughlin, D.; Entekhabi, D.; Ahanin, A.

2011-01-01

The ensemble Kalman filter (EnKF) is susceptible to losing track of observations, or 'diverging', when applied to large chaotic systems such as atmospheric and ocean models. Past studies have demonstrated the adverse impact of sampling error during the filter's update step. We examine how system dynamics affect EnKF performance, and whether the absence of certain dynamic features in the ensemble may lead to divergence. The EnKF is applied to a simple chaotic model, and ensembles are checked against singular vectors of the tangent linear model, corresponding to short-term growth and Lyapunov vectors, corresponding to long-term growth. Results show that the ensemble strongly aligns itself with the subspace spanned by unstable Lyapunov vectors. Furthermore, the filter avoids divergence only if the full linearized long-term unstable subspace is spanned. However, short-term dynamics also become important as non-linearity in the system increases. Non-linear movement prevents errors in the long-term stable subspace from decaying indefinitely. If these errors then undergo linear intermittent growth, a small ensemble may fail to properly represent all important modes, causing filter divergence. A combination of long and short-term growth dynamics are thus critical to EnKF performance. These findings can help in developing practical robust filters based on model dynamics. ?? 2011 The Authors Tellus A ?? 2011 John Wiley & Sons A/S.

Kalman filtering with real-time applications

CERN Document Server

Chui, Charles K

2017-01-01

This new edition presents a thorough discussion of the mathematical theory and computational schemes of Kalman filtering. The filtering algorithms are derived via different approaches, including a direct method consisting of a series of elementary steps, and an indirect method based on innovation projection. Other topics include Kalman filtering for systems with correlated noise or colored noise, limiting Kalman filtering for time-invariant systems, extended Kalman filtering for nonlinear systems, interval Kalman filtering for uncertain systems, and wavelet Kalman filtering for multiresolution analysis of random signals. Most filtering algorithms are illustrated by using simplified radar tracking examples. The style of the book is informal, and the mathematics is elementary but rigorous. The text is self-contained, suitable for self-study, and accessible to all readers with a minimum knowledge of linear algebra, probability theory, and system engineering. Over 100 exercises and problems with solutions help de...

A decoupled approach to filter design for stochastic systems

Science.gov (United States)

Barbata, A.; Zasadzinski, M.; Ali, H. Souley; Messaoud, H.

2016-08-01

This paper presents a new theorem to guarantee the almost sure exponential stability for a class of stochastic triangular systems by studying only the stability of each diagonal subsystems. This result allows to solve the filtering problem of the stochastic systems with multiplicative noises by using the almost sure exponential stability concept. Two kinds of observers are treated: the full-order and reduced-order cases.

Strong Tracking Filter for Nonlinear Systems with Randomly Delayed Measurements and Correlated Noises

Directory of Open Access Journals (Sweden)

Hongtao Yang

2018-01-01

Full Text Available This paper proposes a novel strong tracking filter (STF, which is suitable for dealing with the filtering problem of nonlinear systems when the following cases occur: that is, the constructed model does not match the actual system, the measurements have the one-step random delay, and the process and measurement noises are correlated at the same epoch. Firstly, a framework of decoupling filter (DF based on equivalent model transformation is derived. Further, according to the framework of DF, a new extended Kalman filtering (EKF algorithm via using first-order linearization approximation is developed. Secondly, the computational process of the suboptimal fading factor is derived on the basis of the extended orthogonality principle (EOP. Thirdly, the ultimate form of the proposed STF is obtained by introducing the suboptimal fading factor into the above EKF algorithm. The proposed STF can automatically tune the suboptimal fading factor on the basis of the residuals between available and predicted measurements and further the gain matrices of the proposed STF tune online to improve the filtering performance. Finally, the effectiveness of the proposed STF has been proved through numerical simulation experiments.

Front end support systems for the Advanced Photon Source

International Nuclear Information System (INIS)

Barraza, J.; Shu, D.; Kuzay, T.M.

1993-01-01

The support system designs for the Advanced Photon Source (APS) front ends are complete and will be installed in 1994. These designs satisfy the positioning and alignment requirements of the front end components installed inside the storage ring tunnel, including the photon beam position monitors, fixed masks, photon and safety shutters, filters, windows, and differential pumps. Other components include beam transport pipes and ion pumps. The designs comprise 3-point kinematic mounts and single axis supports to satisfy various multi-direction positioning requirements from course to ultra-precise. The confined space inside the storage ring tunnel has posed engineering challenges in the design of these devices, considering some components weigh as much as 500 kg. These challenges include designing for mobility during commissioning and initial alignment, mechanical and thermal stability, and precise low profile vertical and horizontal positioning. As a result, novel stages and kinematic mounts have emerged with modular and standard designs. This paper will discuss the diverse group of support systems, including specifications and performance data of the prototypes

Tunable electro-optic filter stack

Science.gov (United States)

Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

2017-09-05

A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

Operational readiness of filtered air discharge monitoring systems

International Nuclear Information System (INIS)

Lafortune, J.F.; Jamieson, T.J.

1993-08-01

An assessment of the operational readiness of the Filtered Air Discharge (FAD) Stack Monitoring systems, installed in Canadian CANDU nuclear power plants, was performed in this project. Relevant Canadian and foreign standards and regulatory requirements have been reviewed and documentation on FAD stack monitoring system design, operation, testing and maintenance have been assessed to identify likely causes and potential failures of FAD stack monitoring systems and their components under both standby and accident conditions. Recommendations have also been provided in this report for design and performance review guidelines for CANDU stations. A case study of the FAD stack monitoring system at Pickering NGS is also documented in this report

Digital notch filter based active damping for LCL filters

DEFF Research Database (Denmark)

Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin

2015-01-01

. In contrast, the active damping does not require any dissipation elements, and thus has become of increasing interest. As a result, a vast of active damping solutions have been reported, among which multi-loop control systems and additional sensors are necessary, leading to increased cost and complexity....... In this paper, a notch filter based active damping without the requirement of additional sensors is proposed, where the inverter current is employed as the feedback variable. Firstly, a design method of the notch filter for active damping is presented. The entire system stability has then been investigated...... in the z-domain. Simulations and experiments are carried out to verify the proposed active damping method. Both results have confirmed that the notch filter based active damping can ensure the entire system stability in the case of resonances with a good system performance....

Filter bed systems treating domestic wastewater in the Nordic countries - Performance and reuse of filter media

DEFF Research Database (Denmark)

Jenssen, Petter D.; Krogstad, T.; Paruch, A.M.

2010-01-01

Nine filter beds have been constructed in the Nordic countries, Denmark, Finland, Norway and Sweden. Filter beds consist of a septic tank followed by an aerobic pre-treatment biofilter and a subsequent saturated flow grass-covered filter. Thus, filter beds are similar to subsurface flow construct...

Selection vector filter framework

Science.gov (United States)

Lukac, Rastislav; Plataniotis, Konstantinos N.; Smolka, Bogdan; Venetsanopoulos, Anastasios N.

2003-10-01

We provide a unified framework of nonlinear vector techniques outputting the lowest ranked vector. The proposed framework constitutes a generalized filter class for multichannel signal processing. A new class of nonlinear selection filters are based on the robust order-statistic theory and the minimization of the weighted distance function to other input samples. The proposed method can be designed to perform a variety of filtering operations including previously developed filtering techniques such as vector median, basic vector directional filter, directional distance filter, weighted vector median filters and weighted directional filters. A wide range of filtering operations is guaranteed by the filter structure with two independent weight vectors for angular and distance domains of the vector space. In order to adapt the filter parameters to varying signal and noise statistics, we provide also the generalized optimization algorithms taking the advantage of the weighted median filters and the relationship between standard median filter and vector median filter. Thus, we can deal with both statistical and deterministic aspects of the filter design process. It will be shown that the proposed method holds the required properties such as the capability of modelling the underlying system in the application at hand, the robustness with respect to errors in the model of underlying system, the availability of the training procedure and finally, the simplicity of filter representation, analysis, design and implementation. Simulation studies also indicate that the new filters are computationally attractive and have excellent performance in environments corrupted by bit errors and impulsive noise.

Remotely operated top loading filter housing

International Nuclear Information System (INIS)

Ross, M.J.; Carter, J.A.

1989-01-01

A high-efficiency particulate air (HEPA) filter system was developed for the Fuel Processing Facility at the Idaho Chemical Processing Plant. The system utilizes commercially available HEPA filters and allows in-cell filters to be maintained using operator-controlled remote handling equipment. The remote handling tasks include transport of filters before and after replacement, removal and replacement of the filter from the housing, and filter containment

Applications of Advanced Electromagnetics Components and Systems

CERN Document Server

Kouzaev, Guennadi A

2013-01-01

This text, directed to the microwave engineers and Master and PhD students, is on the use of electromagnetics to the development and design of advanced integrated components distinguished by their extended field of applications. The results of hundreds of authors scattered in numerous journals and conference proceedings are carefully reviewed and classed.  Several chapters are to refresh the knowledge of readers in advanced electromagnetics. New techniques are represented by compact electromagnetic–quantum equations which can be used in modeling of microwave-quantum integrated circuits of future In addition, a topological method to the boundary value problem analysis is considered with the results and examples.  One extended chapter is for the development and design of integrated components for extended bandwidth applications, and the technology and electromagnetic issues of silicon integrated transmission lines, transitions, filters, power dividers, directional couplers, etc are considered. Novel prospec...

A Self-Tuning Kalman Filter for Autonomous Navigation using the Global Positioning System (GPS)

Science.gov (United States)

Truong, S. H.

1999-01-01

Most navigation systems currently operated by NASA are ground-based, and require extensive support to produce accurate results. Recently developed systems that use Kalman filter and GPS data for orbit determination greatly reduce dependency on ground support, and have potential to provide significant economies for NASA spacecraft navigation. These systems, however, still rely on manual tuning from analysts. A sophisticated neuro-fuzzy component fully integrated with the flight navigation system can perform the self-tuning capability for the Kalman filter and help the navigation system recover from estimation errors in real time.

Maximum Correntropy Unscented Kalman Filter for Ballistic Missile Navigation System based on SINS/CNS Deeply Integrated Mode.

Science.gov (United States)

Hou, Bowen; He, Zhangming; Li, Dong; Zhou, Haiyin; Wang, Jiongqi

2018-05-27

Strap-down inertial navigation system/celestial navigation system ( SINS/CNS) integrated navigation is a high precision navigation technique for ballistic missiles. The traditional navigation method has a divergence in the position error. A deeply integrated mode for SINS/CNS navigation system is proposed to improve the navigation accuracy of ballistic missile. The deeply integrated navigation principle is described and the observability of the navigation system is analyzed. The nonlinearity, as well as the large outliers and the Gaussian mixture noises, often exists during the actual navigation process, leading to the divergence phenomenon of the navigation filter. The new nonlinear Kalman filter on the basis of the maximum correntropy theory and unscented transformation, named the maximum correntropy unscented Kalman filter, is deduced, and the computational complexity is analyzed. The unscented transformation is used for restricting the nonlinearity of the system equation, and the maximum correntropy theory is used to deal with the non-Gaussian noises. Finally, numerical simulation illustrates the superiority of the proposed filter compared with the traditional unscented Kalman filter. The comparison results show that the large outliers and the influence of non-Gaussian noises for SINS/CNS deeply integrated navigation is significantly reduced through the proposed filter.

Decentralized control and filtering in interconnected dynamical systems

CERN Document Server

Mahmoud, Magdi S

2011-01-01

Based on the many approaches available for dealing with large-scale systems (LSS), Decentralized Control and Filtering in Interconnected Dynamical Systems supplies a rigorous framework for studying the analysis, stability, and control problems of LSS. Providing an overall assessment of LSS theories, it addresses model order reduction, parametric uncertainties, time delays, and control estimator gain perturbations. Taking readers on a guided tour through LSS, the book examines recent trends and approaches and reviews past methods and results from a contemporary perspective. It traces the progre

Nonlinear stochastic systems with network-induced phenomena recursive filtering and sliding-mode design

CERN Document Server

Hu, Jun; Gao, Huijun

2014-01-01

This monograph introduces methods for handling filtering and control problems in nonlinear stochastic systems arising from network-induced phenomena consequent on limited communication capacity. Such phenomena include communication delay, packet dropout, signal quantization or saturation, randomly occurring nonlinearities and randomly occurring uncertainties.The text is self-contained, beginning with an introduction to nonlinear stochastic systems, network-induced phenomena and filtering and control, moving through a collection of the latest research results which focuses on the three aspects

Command Filtered Adaptive Fuzzy Neural Network Backstepping Control for Marine Power System

Directory of Open Access Journals (Sweden)

Xin Zhang

2014-01-01

Full Text Available In order to retrain chaotic oscillation of marine power system which is excited by periodic electromagnetism perturbation, a novel command-filtered adaptive fuzzy neural network backstepping control method is designed. First, the mathematical model of marine power system is established based on the two parallel nonlinear model. Then, main results of command-filtered adaptive fuzzy neural network backstepping control law are given. And the Lyapunov stability theory is applied to prove that the system can remain closed-loop asymptotically stable with this controller. Finally, simulation results indicate that the designed controller can suppress chaotic oscillation with fast convergence speed that makes the system return to the equilibrium point quickly; meanwhile, the parameter which induces chaotic oscillation can also be discriminated.

A quantum extended Kalman filter

International Nuclear Information System (INIS)

Emzir, Muhammad F; Woolley, Matthew J; Petersen, Ian R

2017-01-01

In quantum physics, a stochastic master equation (SME) estimates the state (density operator) of a quantum system in the Schrödinger picture based on a record of measurements made on the system. In the Heisenberg picture, the SME is a quantum filter. For a linear quantum system subject to linear measurements and Gaussian noise, the dynamics may be described by quantum stochastic differential equations (QSDEs), also known as quantum Langevin equations, and the quantum filter reduces to a so-called quantum Kalman filter. In this article, we introduce a quantum extended Kalman filter (quantum EKF), which applies a commutative approximation and a time-varying linearization to systems of nonlinear QSDEs. We will show that there are conditions under which a filter similar to a classical EKF can be implemented for quantum systems. The boundedness of estimation errors and the filtering problem with ‘state-dependent’ covariances for process and measurement noises are also discussed. We demonstrate the effectiveness of the quantum EKF by applying it to systems that involve multiple modes, nonlinear Hamiltonians, and simultaneous jump-diffusive measurements. (paper)

A quantum extended Kalman filter

Science.gov (United States)

Emzir, Muhammad F.; Woolley, Matthew J.; Petersen, Ian R.

2017-06-01

In quantum physics, a stochastic master equation (SME) estimates the state (density operator) of a quantum system in the Schrödinger picture based on a record of measurements made on the system. In the Heisenberg picture, the SME is a quantum filter. For a linear quantum system subject to linear measurements and Gaussian noise, the dynamics may be described by quantum stochastic differential equations (QSDEs), also known as quantum Langevin equations, and the quantum filter reduces to a so-called quantum Kalman filter. In this article, we introduce a quantum extended Kalman filter (quantum EKF), which applies a commutative approximation and a time-varying linearization to systems of nonlinear QSDEs. We will show that there are conditions under which a filter similar to a classical EKF can be implemented for quantum systems. The boundedness of estimation errors and the filtering problem with ‘state-dependent’ covariances for process and measurement noises are also discussed. We demonstrate the effectiveness of the quantum EKF by applying it to systems that involve multiple modes, nonlinear Hamiltonians, and simultaneous jump-diffusive measurements.

Replacement of fine particle purification filter of the PHT purification system - 15083

International Nuclear Information System (INIS)

Lee, D.S.

2015-01-01

The increase of chalk river unidentified deposit (CRUD), a particulate corrosion product in PHT (primary heat transport) system with increased operating years of a nuclear power plant causes: -) the problems of increased heavy water decomposition and deuterium formation reaction due to catalytic reaction with CRUD, -) damage to PHT pump seal due to a corrosion product, -) damage to fuel channel closure seal, and increased radiation exposure of workers due to elevated dose rate in steam generator water chamber. Wolsung unit 3 and 4 have replaced fine filter media in PHT purification system in phases reducing the pore size of the filter media (5 μm → 2 μm → 1 μm → 0.45 μm) to solve this problem. The phased replacement of fine filter media by the one with a smaller pore size reduced CRUD in PHT system significantly and also radiation dose rate in steam generator water chamber. Accordingly, many problems related to the aging of a plant (including increased radiation exposure of workers during outage, damage to mechanical seal of PHT pump) have been solved. (author)

Particle Kalman Filtering: A Nonlinear Framework for Ensemble Kalman Filters

KAUST Repository

Hoteit, Ibrahim

2010-09-19

Optimal nonlinear filtering consists of sequentially determining the conditional probability distribution functions (pdf) of the system state, given the information of the dynamical and measurement processes and the previous measurements. Once the pdfs are obtained, one can determine different estimates, for instance, the minimum variance estimate, or the maximum a posteriori estimate, of the system state. It can be shown that, many filters, including the Kalman filter (KF) and the particle filter (PF), can be derived based on this sequential Bayesian estimation framework. In this contribution, we present a Gaussian mixture‐based framework, called the particle Kalman filter (PKF), and discuss how the different EnKF methods can be derived as simplified variants of the PKF. We also discuss approaches to reducing the computational burden of the PKF in order to make it suitable for complex geosciences applications. We use the strongly nonlinear Lorenz‐96 model to illustrate the performance of the PKF.

Manipulation Robustness of Collaborative Filtering

OpenAIRE

Benjamin Van Roy; Xiang Yan

2010-01-01

A collaborative filtering system recommends to users products that similar users like. Collaborative filtering systems influence purchase decisions and hence have become targets of manipulation by unscrupulous vendors. We demonstrate that nearest neighbors algorithms, which are widely used in commercial systems, are highly susceptible to manipulation and introduce new collaborative filtering algorithms that are relatively robust.

Quick-change filter cartridge

Science.gov (United States)

Rodgers, John C.; McFarland, Andrew R.; Ortiz, Carlos A.

1995-01-01

A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

Impacts of backwashing on granular activated carbon filters for advanced wastewater treatment.

Science.gov (United States)

Frank, Joshua; Ruhl, Aki Sebastian; Jekel, Martin

2015-12-15

The use of granular activated carbon (GAC) in fixed bed filters is a promising option for the removal of organic micropollutants (OMP) from wastewater treatment plant effluents. Frequent backwashing of the filter bed is inevitable, but its effect on potential filter stratification is not well understood yet and thus has been evaluated in the present study for two commercial GAC products. Backwashing of GAC filters was simulated with 10 or 100 filter bed expansions of 20 or 100% at backwash velocities of 12 and 40 m/h, respectively. Five vertical fractions were extracted and revealed a vertical stratification according to grain sizes and material densities. Sieve analyses indicated increasing grain sizes towards the bottom for one GAC while grain sizes of the other GAC were more homogeneously distributed throughout the filter bed. The apparent densities of the top sections were significantly lower than that of the bottom sections of both products. Comparative long term fixed bed adsorption experiments with the top and bottom sections of the stratified GAC showed remarkable differences in breakthrough curves of dissolved organic carbon, UV light absorption at 254 nm wavelength (UVA254) and OMP. GAC from the upper section showed constantly better removal efficiencies than GAC from the bottom section, especially for weakly adsorbing OMP such as sulfamethoxazole. Furthermore correlations between UVA254 reductions and OMP removals were found. Copyright © 2015 Elsevier Ltd. All rights reserved.

Model-Based Engine Control Architecture with an Extended Kalman Filter

Science.gov (United States)

Csank, Jeffrey T.; Connolly, Joseph W.

2016-01-01

This paper discusses the design and implementation of an extended Kalman filter (EKF) for model-based engine control (MBEC). Previously proposed MBEC architectures feature an optimal tuner Kalman Filter (OTKF) to produce estimates of both unmeasured engine parameters and estimates for the health of the engine. The success of this approach relies on the accuracy of the linear model and the ability of the optimal tuner to update its tuner estimates based on only a few sensors. Advances in computer processing are making it possible to replace the piece-wise linear model, developed off-line, with an on-board nonlinear model running in real-time. This will reduce the estimation errors associated with the linearization process, and is typically referred to as an extended Kalman filter. The nonlinear extended Kalman filter approach is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (C-MAPSS40k) and compared to the previously proposed MBEC architecture. The results show that the EKF reduces the estimation error, especially during transient operation.

Evaluation of self-contained HEPA filter

Energy Technology Data Exchange (ETDEWEB)

Arndt, T.E. [Westinghouse Hanford Company, Richland, WA (United States)

1995-02-01

This paper presents the results of an evaluation of a self-contained high-efficiency particulate air filter (SHEPA) used in nuclear applications. A SCHEPA consists of filter medium encapsulated in a casing that is part of the system boundary. The SCHEPA filter serves as a combination of filter housing and filter. The filter medium is attached directly to the casing using adhesive as a bonding agent. A cylindrical connection in the middle of the end caps connects the filter assembly to adjoining ductwork. The SCHEPA must perform the functions of a filter housing, filter frame, and filter. It was recognized that the codes and standards do not address the SCHEPA specifically. Therefore, the investigation evaluated the SCHEPA against current codes and standards related to the functional requirements of an air-cleaning system. The specific standards used are required by DOE Order 6430.1A{sup 1} and include ASME N509{sup 3}, ASME N510{sup 4}, ERDA 76-21{sup 5}, MIL-F-51068F{sup 6}, NFPA 90A, {sup 7} and NFPA 91{sup 8}. The evaluation does not address whether the SCHEPA as a standard (off-the-shelf) filter could be upgraded to meet the current code requirements for an air-cleaning unit. The evaluation also did not consider how the SCHEPA was used in a system (e.g., whether it was under positive or negative pressure or whether it served as an air inlet filter to prevent contamination releases under system pressurization). The results of the evaluation show that, the SCHEPA filter does not meet design, fabrication, testing, and documentation requirements of ASME N509{sup 3} and ASME N510{sup 4}. The paper will identify these deficiencies. Specific exhaust system requirements and application should be considered when an evaluation of the SCHEPA filter is being performed in existing systems. When new designs are being comtemplated, other types of HEPA filter housings can be used in lieu of the SCHEPA filter.

Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

Science.gov (United States)

Möritz, M; Peters, H; Nipko, B; Rüden, H

2001-07-01

The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry ( 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

Line filter design of parallel interleaved VSCs for high power wind energy conversion systems

DEFF Research Database (Denmark)

Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

2015-01-01

The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper...... limit. In order to achieve the desired filter performance with optimal values of the filter parameters, the use of a LC trap branch with the conventional LCL filter is proposed. The expressions for the resonant frequencies of the proposed line filter are derived and used in the design to selectively...

Advanced gadolinia core and Toshiba advanced reactor management system

International Nuclear Information System (INIS)

Miyamoto, Toshiki; Yoshioka, Ritsuo; Ebisuya, Mitsuo

1988-01-01

At the Hamaoka Nuclear Power Station, Unit No. 3, advanced core design and core management technology have been adopted, significantly improving plant availability, operability and reliability. The outstanding technologies are the advanced gadolinia core (AGC) which utilizes gadolinium for the axial power distribution control, and Toshiba advanced reactor management system (TARMS) which uses a three-dimensional core physics simulator to calculate the power distribution. Presented here are the effects of these advanced technologies as observed during field testing. (author)

Design and Analysis of Robust Active Damping for LCL Filters using Digital Notch Filters

DEFF Research Database (Denmark)

Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin

2017-01-01

Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp the reso......Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp...... the resonance, where the notch frequency should be aligned exactly to the resonant frequency of the LCL filter. However, parameter variations of the LCL filter as well as the time delay appearing in digital control systems will induce resonance drifting, and thus break this alignment, possibly deteriorating...... the original damping. In this paper, the effectiveness of the notch filter based active damping is firstly explored, considering the drifts of the resonant frequency. It is revealed that, when the resonant frequency drifts away from its nominal value, the phase lead or lag introduced by the notch filter may...

Re-Investigation of Generalized Integrator Based Filters From a First-Order-System Perspective

DEFF Research Database (Denmark)

Xin, Zhen; Zhao, Rende; Mattavelli, Paolo

2016-01-01

The generalized integrator (GI)-based filters can be categorized into two types: one is related to quadrature signal generator (QSG), and the other is related to sequence filter (SF). The QSG is used for generating the in-quadrature sinusoidal signals and the SF works for extracting the symmetrical...... extended structures and thus restrict their applications. To overcome the drawback, this paper uses the first-order-system concept to re-investigate the GI-based filters, with which their working principles can be intuitively understood and their structure correlations can be easily discovered. Moreover...

Load compensation for single phase system using series active filter ...

African Journals Online (AJOL)

Load compensation for single phase system using series active filter. ... KK Mishra, R Gupta ... load varies from time to time, the non linear load ranging from voltage source type harmonic load (VSHL) dominant to current source type harmonic ...

Maximum Correntropy Unscented Kalman Filter for Ballistic Missile Navigation System based on SINS/CNS Deeply Integrated Mode

Directory of Open Access Journals (Sweden)

Bowen Hou

2018-05-01

Full Text Available Strap-down inertial navigation system/celestial navigation system ( SINS/CNS integrated navigation is a high precision navigation technique for ballistic missiles. The traditional navigation method has a divergence in the position error. A deeply integrated mode for SINS/CNS navigation system is proposed to improve the navigation accuracy of ballistic missile. The deeply integrated navigation principle is described and the observability of the navigation system is analyzed. The nonlinearity, as well as the large outliers and the Gaussian mixture noises, often exists during the actual navigation process, leading to the divergence phenomenon of the navigation filter. The new nonlinear Kalman filter on the basis of the maximum correntropy theory and unscented transformation, named the maximum correntropy unscented Kalman filter, is deduced, and the computational complexity is analyzed. The unscented transformation is used for restricting the nonlinearity of the system equation, and the maximum correntropy theory is used to deal with the non-Gaussian noises. Finally, numerical simulation illustrates the superiority of the proposed filter compared with the traditional unscented Kalman filter. The comparison results show that the large outliers and the influence of non-Gaussian noises for SINS/CNS deeply integrated navigation is significantly reduced through the proposed filter.

A tool for filtering information in complex systems

Science.gov (United States)

Tumminello, M.; Aste, T.; Di Matteo, T.; Mantegna, R. N.

2005-07-01

We introduce a technique to filter out complex data sets by extracting a subgraph of representative links. Such a filtering can be tuned up to any desired level by controlling the genus of the resulting graph. We show that this technique is especially suitable for correlation-based graphs, giving filtered graphs that preserve the hierarchical organization of the minimum spanning tree but containing a larger amount of information in their internal structure. In particular in the case of planar filtered graphs (genus equal to 0), triangular loops and four-element cliques are formed. The application of this filtering procedure to 100 stocks in the U.S. equity markets shows that such loops and cliques have important and significant relationships with the market structure and properties. This paper was submitted directly (Track II) to the PNAS office.Abbreviations: MST, minimum spanning tree; PMFG, Planar Maximally Filtered Graph; r-clique, clique of r elements.

Weighted H∞ Filtering for a Class of Switched Linear Systems with Additive Time-Varying Delays

Directory of Open Access Journals (Sweden)

Li-li Li

2015-01-01

Full Text Available This paper is concerned with the problem of weighted H∞ filtering for a class of switched linear systems with two additive time-varying delays, which represent a general class of switched time-delay systems with strong practical background. Combining average dwell time (ADT technique with piecewise Lyapunov functionals, sufficient conditions are established to guarantee the exponential stability and weighted H∞ performance for the filtering error systems. The parameters of the designed switched filters are obtained by solving linear matrix inequalities (LMIs. A modification of Jensen integral inequality is exploited to derive results with less theoretical conservatism and computational complexity. Finally, two examples are given to demonstrate the effectiveness of the proposed method.

Channel Estimation for Filter Bank Multicarrier Systems in Low SNR Environments

Energy Technology Data Exchange (ETDEWEB)

Driggs, Jonathan; Sibbett, Taylor; Moradiy, Hussein; Farhang-Boroujeny, Behrouz

2017-05-01

Channel estimation techniques are crucial for reliable communications. This paper is concerned with channel estimation in a filter bank multicarrier spread spectrum (FBMCSS) system. We explore two channel estimator options: (i) a method that makes use of a periodic preamble and mimics the channel estimation techniques that are widely used in OFDM-based systems; and (ii) a method that stays within the traditional realm of filter bank signal processing. For the case where the channel noise is white, both methods are analyzed in detail and their performance is compared against their respective Cramer-Rao Lower Bounds (CRLB). Advantages and disadvantages of the two methods under different channel conditions are given to provide insight to the reader as to when one will outperform the other.

The OGC Innovation Program Testbeds - Advancing Architectures for Earth and Systems

Science.gov (United States)

Bermudez, L. E.; Percivall, G.; Simonis, I.; Serich, S.

2017-12-01

The OGC Innovation Program provides a collaborative agile process for solving challenging science problems and advancing new technologies. Since 1999, 100 initiatives have taken place, from multi-million dollar testbeds to small interoperability experiments. During these initiatives, sponsors and technology implementers (including academia and private sector) come together to solve problems, produce prototypes, develop demonstrations, provide best practices, and advance the future of standards. This presentation will provide the latest system architectures that can be used for Earth and space systems as a result of the OGC Testbed 13, including the following components: Elastic cloud autoscaler for Earth Observations (EO) using a WPS in an ESGF hybrid climate data research platform. Accessibility of climate data for the scientist and non-scientist users via on demand models wrapped in WPS. Standards descriptions for containerize applications to discover processes on the cloud, including using linked data, a WPS extension for hybrid clouds and linking to hybrid big data stores. OpenID and OAuth to secure OGC Services with built-in Attribute Based Access Control (ABAC) infrastructures leveraging GeoDRM patterns. Publishing and access of vector tiles, including use of compression and attribute options reusing patterns from WMS, WMTS and WFS. Servers providing 3D Tiles and streaming of data, including Indexed 3d Scene Layer (I3S), CityGML and Common DataBase (CDB). Asynchronous Services with advanced pushed notifications strategies, with a filter language instead of simple topic subscriptions, that can be use across OGC services. Testbed 14 will continue advancing topics like Big Data, security, and streaming, as well as making easier to use OGC services (e.g. RESTful APIs). The Call for Participation will be issued in December and responses are due on mid January 2018.

Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

Science.gov (United States)

Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

2017-01-01

Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

An adaptive three-stage extended Kalman filter for nonlinear discrete-time system in presence of unknown inputs.

Science.gov (United States)

Xiao, Mengli; Zhang, Yongbo; Wang, Zhihua; Fu, Huimin

2018-04-01

Considering the performances of conventional Kalman filter may seriously degrade when it suffers stochastic faults and unknown input, which is very common in engineering problems, a new type of adaptive three-stage extended Kalman filter (AThSEKF) is proposed to solve state and fault estimation in nonlinear discrete-time system under these conditions. The three-stage UV transformation and adaptive forgetting factor are introduced for derivation, and by comparing with the adaptive augmented state extended Kalman filter, it is proven to be uniformly asymptotically stable. Furthermore, the adaptive three-stage extended Kalman filter is applied to a two-dimensional radar tracking scenario to illustrate the effect, and the performance is compared with that of conventional three stage extended Kalman filter (ThSEKF) and the adaptive two-stage extended Kalman filter (ATEKF). The results show that the adaptive three-stage extended Kalman filter is more effective than these two filters when facing the nonlinear discrete-time systems with information of unknown inputs not perfectly known. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

A Quantised State Systems Approach for Jacobian Free Extended Kalman Filtering

DEFF Research Database (Denmark)

Alminde, Lars; Bendtsen, Jan Dimon; Stoustrup, Jakob

2007-01-01

Model based methods for control of intelligent autonomous systems rely on a state estimate being available. One of the most common methods to obtain a state estimate for non-linear systems is the Extended Kalman Filter (EKF) algorithm. In order to apply the EKF an expression must be available...

DEMONSTRATION BULLETIN: COLLOID POLISHING FILTER METHOD - FILTER FLOW TECHNOLOGY, INC.

Science.gov (United States)

The Filter Flow Technology, Inc. (FFT) Colloid Polishing Filter Method (CPFM) was tested as a transportable, trailer mounted, system that uses sorption and chemical complexing phenomena to remove heavy metals and nontritium radionuclides from water. Contaminated waters can be pro...

A Novel Robust H∞ Filter Based on Krein Space Theory in the SINS/CNS Attitude Reference System

Directory of Open Access Journals (Sweden)

Fei Yu

2016-03-01

Full Text Available Owing to their numerous merits, such as compact, autonomous and independence, the strapdown inertial navigation system (SINS and celestial navigation system (CNS can be used in marine applications. What is more, due to the complementary navigation information obtained from two different kinds of sensors, the accuracy of the SINS/CNS integrated navigation system can be enhanced availably. Thus, the SINS/CNS system is widely used in the marine navigation field. However, the CNS is easily interfered with by the surroundings, which will lead to the output being discontinuous. Thus, the uncertainty problem caused by the lost measurement will reduce the system accuracy. In this paper, a robust H∞ filter based on the Krein space theory is proposed. The Krein space theory is introduced firstly, and then, the linear state and observation models of the SINS/CNS integrated navigation system are established reasonably. By taking the uncertainty problem into account, in this paper, a new robust H∞ filter is proposed to improve the robustness of the integrated system. At last, this new robust filter based on the Krein space theory is estimated by numerical simulations and actual experiments. Additionally, the simulation and experiment results and analysis show that the attitude errors can be reduced by utilizing the proposed robust filter effectively when the measurements are missing discontinuous. Compared to the traditional Kalman filter (KF method, the accuracy of the SINS/CNS integrated system is improved, verifying the robustness and the availability of the proposed robust H∞ filter.

Design and Implementation of Data Acquisition System Based on Digital Filtering Method for the Electrical Capacitance Tomography

Directory of Open Access Journals (Sweden)

LI Yang

2017-02-01

Full Text Available Aiming at the problem of high frequency noise interference in the ECT data acquisition system，on the basis of analysis of the ECT system data acquisition and control principles，we designed an improved distributed algorithm FIR low-pass digital filter combined with FPGA technology and digital filtering principle. The sampling frequency of the filter is 1 .5 MHz，the pass band cutoff frequency is 20MHz，and the design method is window function. We used the FDATooI toolbox in Matlab to extract and quantify the filter coefficients and the Quarters to simulate the simulation. Experimental results showed that the FIR digital filter can achieve the filtering function of the high frequency signal in the data acquisition system. Compared with the traditional DA algorithm，it has the advantages of small resource consumption and high acquisition speed and some other characteristics.

Technical note: Improving the AWAT filter with interpolation schemes for advanced processing of high resolution data

Science.gov (United States)

Peters, Andre; Nehls, Thomas; Wessolek, Gerd

2016-06-01

Weighing lysimeters with appropriate data filtering yield the most precise and unbiased information for precipitation (P) and evapotranspiration (ET). A recently introduced filter scheme for such data is the AWAT (Adaptive Window and Adaptive Threshold) filter (Peters et al., 2014). The filter applies an adaptive threshold to separate significant from insignificant mass changes, guaranteeing that P and ET are not overestimated, and uses a step interpolation between the significant mass changes. In this contribution we show that the step interpolation scheme, which reflects the resolution of the measuring system, can lead to unrealistic prediction of P and ET, especially if they are required in high temporal resolution. We introduce linear and spline interpolation schemes to overcome these problems. To guarantee that medium to strong precipitation events abruptly following low or zero fluxes are not smoothed in an unfavourable way, a simple heuristic selection criterion is used, which attributes such precipitations to the step interpolation. The three interpolation schemes (step, linear and spline) are tested and compared using a data set from a grass-reference lysimeter with 1 min resolution, ranging from 1 January to 5 August 2014. The selected output resolutions for P and ET prediction are 1 day, 1 h and 10 min. As expected, the step scheme yielded reasonable flux rates only for a resolution of 1 day, whereas the other two schemes are well able to yield reasonable results for any resolution. The spline scheme returned slightly better results than the linear scheme concerning the differences between filtered values and raw data. Moreover, this scheme allows continuous differentiability of filtered data so that any output resolution for the fluxes is sound. Since computational burden is not problematic for any of the interpolation schemes, we suggest always using the spline scheme.

Reducing and verifying haloacetic acids in treated drinking water using a biological filter system.

Science.gov (United States)

Lou, Jie C; Chan, Hung Y; Yang, Chih Y; Tseng, Wei B; Han, Jia Y

2014-01-01

This study focused on reducing the haloacetic acid (HAA) concentrations in treated drinking water. HAA has been thought to be one possible nutrient supporting heterotrophic bacteria regrowth in drinking water. In this study, experiments were conducted using a pilot-scale system to evaluate the efficiency of biological filters (BF) for reducing excess HAA concentrations in water. The BF system reduced the total HAA concentration and the concentrations of five HAA species in the water. Dichloroacetic acid (DCAA), monobromoacetic acid (MBAA) and dibromoacetic acid (DBAA) were the three main HAA5 species that were present in the treated drinking water in this investigation. Combined, these three species represent approximately 77% of the HAA5 in the finished water after BF. The verification of the empirical HAA equation for the outlet in the BF system indicated linear relationships with high correlation coefficients. The empirical equation for the HAA5 concentrations in the finished water was established by examining other nutrients (e.g., dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV254), and ammonia nitrogen) that can reduce pathogenic contamination. These findings may be useful for designing advanced processes for conventional water treatment plants or for managing water treatment and distribution systems for providing high-quality drinking water.

Directional Joint Bilateral Filter for Depth Images

Directory of Open Access Journals (Sweden)

Anh Vu Le

2014-06-01

Full Text Available Depth maps taken by the low cost Kinect sensor are often noisy and incomplete. Thus, post-processing for obtaining reliable depth maps is necessary for advanced image and video applications such as object recognition and multi-view rendering. In this paper, we propose adaptive directional filters that fill the holes and suppress the noise in depth maps. Specifically, novel filters whose window shapes are adaptively adjusted based on the edge direction of the color image are presented. Experimental results show that our method yields higher quality filtered depth maps than other existing methods, especially at the edge boundaries.

Development of off-gas filters for reprocessing plants. Development and construction of an off-gas filter system for large reprocessing plants. Off-gas section of the resolver test stand of the IHCh

International Nuclear Information System (INIS)

Furrer, J.; Kaempffer, R.; Wilhelm, J.G.; Pfauter, C.; Jannakos, K.; Apenberg, W.; Lange, W.; Mendel, W.; Potgeter, G.; Zabel, G.

1976-01-01

The test of the highly impregnated iodine sorption material AC 6,120 was continued in the laboratory under simulated conditions of a 1,500 t/a uranium reprocessing plant. The influence of NO in nitrogen as the carrier gas on the removal efficiency of the sorption material has been especially examined. Several experiments on the removal efficiency of iodine sorption by the material AC 6,120 were carried out in the original off-gas of the French processing plant SAP Marcoule while the filter system was installed on the one side directly behind the dissolver and on the other side behind the iodine desorption columm. The first iodine filter developed at LAF II was installed in the off-gas line of the dissolver in the Karlsruhe reprocessing plant. The filter system for the dissolver off-gas handling test rig of the IHCh was specified and ordered with an engineering firm. The conception of the prototype off-gas filter system was selected and a lock and transport system allowing to replace filters was designed and subjected for testing. Five alternative solutions were set up in order to find the appropriate filter concept. The method of selection based on the evaluation of performance criteria. According to the selected solution a filter drum was designed and constructed. The lock of the filter system has been designed and realized. Preliminary tests have been made. (orig.) [de

Method and system for training dynamic nonlinear adaptive filters which have embedded memory

Science.gov (United States)

Rabinowitz, Matthew (Inventor)

2002-01-01

Described herein is a method and system for training nonlinear adaptive filters (or neural networks) which have embedded memory. Such memory can arise in a multi-layer finite impulse response (FIR) architecture, or an infinite impulse response (IIR) architecture. We focus on filter architectures with separate linear dynamic components and static nonlinear components. Such filters can be structured so as to restrict their degrees of computational freedom based on a priori knowledge about the dynamic operation to be emulated. The method is detailed for an FIR architecture which consists of linear FIR filters together with nonlinear generalized single layer subnets. For the IIR case, we extend the methodology to a general nonlinear architecture which uses feedback. For these dynamic architectures, we describe how one can apply optimization techniques which make updates closer to the Newton direction than those of a steepest descent method, such as backpropagation. We detail a novel adaptive modified Gauss-Newton optimization technique, which uses an adaptive learning rate to determine both the magnitude and direction of update steps. For a wide range of adaptive filtering applications, the new training algorithm converges faster and to a smaller value of cost than both steepest-descent methods such as backpropagation-through-time, and standard quasi-Newton methods. We apply the algorithm to modeling the inverse of a nonlinear dynamic tracking system 5, as well as a nonlinear amplifier 6.

Robust filtering and prediction for systems with embedded finite-state Markov-Chain dynamics

International Nuclear Information System (INIS)

Pate, E.B.

1986-01-01

This research developed new methodologies for the design of robust near-optimal filters/predictors for a class of system models that exhibit embedded finite-state Markov-chain dynamics. These methodologies are developed through the concepts and methods of stochastic model building (including time-series analysis), game theory, decision theory, and filtering/prediction for linear dynamic systems. The methodology is based on the relationship between the robustness of a class of time-series models and quantization which is applied to the time series as part of the model identification process. This relationship is exploited by utilizing the concept of an equivalence, through invariance of spectra, between the class of Markov-chain models and the class of autoregressive moving average (ARMA) models. This spectral equivalence permits a straightforward implementation of the desirable robust properties of the Markov-chain approximation in a class of models which may be applied in linear-recursive form in a linear Kalman filter/predictor structure. The linear filter/predictor structure is shown to provide asymptotically optimal estimates of states which represent one or more integrations of the Markov-chain state. The development of a new saddle-point theorem for a game based on the Markov-chain model structure gives rise to a technique for determining a worst case Markov-chain process, upon which a robust filter/predictor design if based

An Improved Strong Tracking Cubature Kalman Filter for GPS/INS Integrated Navigation Systems.

Science.gov (United States)

Feng, Kaiqiang; Li, Jie; Zhang, Xi; Zhang, Xiaoming; Shen, Chong; Cao, Huiliang; Yang, Yanyu; Liu, Jun

2018-06-12

The cubature Kalman filter (CKF) is widely used in the application of GPS/INS integrated navigation systems. However, its performance may decline in accuracy and even diverge in the presence of process uncertainties. To solve the problem, a new algorithm named improved strong tracking seventh-degree spherical simplex-radial cubature Kalman filter (IST-7thSSRCKF) is proposed in this paper. In the proposed algorithm, the effect of process uncertainty is mitigated by using the improved strong tracking Kalman filter technique, in which the hypothesis testing method is adopted to identify the process uncertainty and the prior state estimate covariance in the CKF is further modified online according to the change in vehicle dynamics. In addition, a new seventh-degree spherical simplex-radial rule is employed to further improve the estimation accuracy of the strong tracking cubature Kalman filter. In this way, the proposed comprehensive algorithm integrates the advantage of 7thSSRCKF’s high accuracy and strong tracking filter’s strong robustness against process uncertainties. The GPS/INS integrated navigation problem with significant dynamic model errors is utilized to validate the performance of proposed IST-7thSSRCKF. Results demonstrate that the improved strong tracking cubature Kalman filter can achieve higher accuracy than the existing CKF and ST-CKF, and is more robust for the GPS/INS integrated navigation system.

The Advanced LIGO timing system

International Nuclear Information System (INIS)

Bartos, Imre; Factourovich, Maxim; Marka, Szabolcs; Marka, Zsuzsa; Raics, Zoltan; Bork, Rolf; Heefner, Jay; Schwinberg, Paul; Sigg, Daniel

2010-01-01

Gravitational wave detection using a network of detectors relies upon the precise time stamping of gravitational wave signals. The relative arrival times between detectors are crucial, e.g. in recovering the source direction, an essential step in using gravitational waves for multi-messenger astronomy. Due to the large size of gravitational wave detectors, timing at different parts of a given detector also needs to be highly synchronized. In general, the requirement toward the precision of timing is determined such that, upon detection, the deduced (astro-) physical results should not be limited by the precision of timing. The Advanced LIGO optical timing distribution system is designed to provide UTC-synchronized timing information for the Advanced LIGO detectors that satisfies the above criterium. The Advanced LIGO timing system has modular structure, enabling quick and easy adaptation to the detector frame as well as possible changes or additions of components. It also includes a self-diagnostics system that enables the remote monitoring of the status of timing. After the description of the Advanced LIGO timing system, several tests are presented that demonstrate its precision and robustness.

Energy-Efficient Distributed Filtering in Sensor Networks: A Unified Switched System Approach.

Science.gov (United States)

Zhang, Dan; Shi, Peng; Zhang, Wen-An; Yu, Li

2016-04-21

This paper is concerned with the energy-efficient distributed filtering in sensor networks, and a unified switched system approach is proposed to achieve this goal. For the system under study, the measurement is first sampled under nonuniform sampling periods, then the local measurement elements are selected and quantized for transmission. Then, the transmission rate is further reduced to save constrained power in sensors. Based on the switched system approach, a unified model is presented to capture the nonuniform sampling, the measurement size reduction, the transmission rate reduction, the signal quantization, and the measurement missing phenomena. Sufficient conditions are obtained such that the filtering error system is exponentially stable in the mean-square sense with a prescribed H∞ performance level. Both simulation and experiment studies are given to show the effectiveness of the proposed new design technique.

Impact of Physician Education and a Dedicated Inferior Vena Cava Filter Tracking System on Inferior Vena Cava Filter Use and Retrieval Rates Across a Large US Health Care Region.

Science.gov (United States)

Wang, Stephen L; Cha, Hsien-Hwa A; Lin, James R; Francis, Bolanos; Elizabeth, Wakley; Martin, Porras; Rajan, Sudhir

2016-05-01

To evaluate the effects of physician familiarity with current evidence and guidelines on inferior vena cava (IVC) filter use and the availability of IVC filter tracking infrastructure on retrieval rates. Fourteen continuing medical education-approved in-hospital grand rounds covering evidence-based review of the literature on IVC filter efficacy, patient-centered outcomes, guidelines for IVC filter indications, and complications were performed across a large United States (US) health care region serving more than 3.5 million members. A computer-based IVC filter tracking system was deployed simultaneously. IVC filter use, rates of attempted retrieval, and fulfillment of guidelines for IVC filter indications were retrospectively evaluated at each facility for 12 months before intervention (n = 427) and for 12 months after intervention (n = 347). After education, IVC filter use decreased 18.7%, with a member enrollment-adjusted decrease of 22.2%, despite an increasing IVC filter use trend for 4 years. Reduction in IVC filter use at each facility strongly correlated with physician attendance at grand rounds (r = -0.69; P = .007). Rates of attempted retrieval increased from 38.9% to 54.0% (P = .0006), with similar rates of successful retrieval (82.3% before education and 85.8% after education on first attempt). Improvement in IVC filter retrieval attempts correlated with physician attendance at grand rounds (r = 0.51; P = .051). IVC filter dwell times at first retrieval attempt were similar (10.2 wk before and 10.8 wk after). Physician education dramatically reduced IVC filter use across a large US health care region, and represents a learning opportunity for physicians who request and place them. Education and a novel tracking system improved rates of retrieval for IVC filter devices. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Experimental investigation of in situ cleanable HEPA filter

International Nuclear Information System (INIS)

Adamson, D.J.

1999-01-01

The Westinghouse Savannah River Company located at the Savannah River Site (SRS) in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air (HEPA) filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ. The tanks are equipped with a ventilation system to maintain the tank contents at negative pressure to prevent the release of radioactive material to the environment. This system is equipped with conventional disposable glass-fiber HEPA filter cartridges. Removal and disposal of these filters is not only costly, but subjects site personnel to radiation exposure and possible contamination. A test apparatus was designed to simulate the ventilation system of a HLW tank with an in situ cleaning system. Test results indicate that the Mott sintered metal HEPA filter is suitable as an in situ cleanable or regenerable HEPA filter. Data indicates that high humidity or water did not effect the filter performance and the sintered metal HEPA filter was easily cleaned numerous times back to new filter performance by an in situ spray system. The test apparatus allows the cleaning of the soiled HEPA filters to be accomplished without removing the filters from process. This innovative system would eliminate personnel radiation exposure associated with removal of contaminated filters and the high costs of filter replacement and disposal. The results of these investigations indicate that an in situ cleanable HEPA filter system for radioactive and commercial use could be developed and manufactured

Development and evaluation of a plant-based air filter system for ...

African Journals Online (AJOL)

Y. Choi

2013-04-17

Apr 17, 2013 ... plant based filter system on bacterial growth in aqueous media, the compressed air was fed to the system at a rate of 200 mL/min, and the exhaust gas from the system was supplied to a bacterial culture. In this experiment, we attempted to verify the inhibition activity of the gas on bacterial growth in aqueous ...

State and parameter estimation of the heat shock response system using Kalman and particle filters.

Science.gov (United States)

Liu, Xin; Niranjan, Mahesan

2012-06-01

Traditional models of systems biology describe dynamic biological phenomena as solutions to ordinary differential equations, which, when parameters in them are set to correct values, faithfully mimic observations. Often parameter values are tweaked by hand until desired results are achieved, or computed from biochemical experiments carried out in vitro. Of interest in this article, is the use of probabilistic modelling tools with which parameters and unobserved variables, modelled as hidden states, can be estimated from limited noisy observations of parts of a dynamical system. Here we focus on sequential filtering methods and take a detailed look at the capabilities of three members of this family: (i) extended Kalman filter (EKF), (ii) unscented Kalman filter (UKF) and (iii) the particle filter, in estimating parameters and unobserved states of cellular response to sudden temperature elevation of the bacterium Escherichia coli. While previous literature has studied this system with the EKF, we show that parameter estimation is only possible with this method when the initial guesses are sufficiently close to the true values. The same turns out to be true for the UKF. In this thorough empirical exploration, we show that the non-parametric method of particle filtering is able to reliably estimate parameters and states, converging from initial distributions relatively far away from the underlying true values. Software implementation of the three filters on this problem can be freely downloaded from http://users.ecs.soton.ac.uk/mn/HeatShock

T-S Fuzzy Model-Based Approximation and Filter Design for Stochastic Time-Delay Systems with Hankel Norm Criterion

Directory of Open Access Journals (Sweden)

Yanhui Li

2014-01-01

Full Text Available This paper investigates the Hankel norm filter design problem for stochastic time-delay systems, which are represented by Takagi-Sugeno (T-S fuzzy model. Motivated by the parallel distributed compensation (PDC technique, a novel filtering error system is established. The objective is to design a suitable filter that guarantees the corresponding filtering error system to be mean-square asymptotically stable and to have a specified Hankel norm performance level γ. Based on the Lyapunov stability theory and the Itô differential rule, the Hankel norm criterion is first established by adopting the integral inequality method, which can make some useful efforts in reducing conservativeness. The Hankel norm filtering problem is casted into a convex optimization problem with a convex linearization approach, which expresses all the conditions for the existence of admissible Hankel norm filter as standard linear matrix inequalities (LMIs. The effectiveness of the proposed method is demonstrated via a numerical example.

Plasmonic color-graded nanosystems with achromatic sub-wavelength architectures for light filtering and advanced SERS detection

KAUST Repository

Proietti Zaccaria, Remo

2016-03-09

Plasmonic colour-graded systems are devices featuring a spatially variable plasmonic response over their surface. They are widely used as nanoscale colour filters; their typical size is small enough to allow integration with miniaturized electronic circuits paving the way to realize novel nanophotonic devices. Currently, most plasmonic colour-graded systems are intrinsically discrete, as their chromatic response exploits the tailored plasmon resonance of micro-architectures characterized by different size and/or geometry for each target colour. Here we report the realization of multifunctional plasmon-graded devices where continuously-graded chromatic response is achieved by smoothly tuning the composition of the resonator material while simultaneously maintaining an achromatic nanoscale geometry. The result is a new class of versatile materials: we show their application as plasmonic filters with a potential pixel size smaller than half of the exciting wavelength, but also as multiplexed surface-enhanced Raman spectroscopy (SERS) substrates. Many more implementations, like photovoltaic efficiency boosters or colour routers await, and will benefit from the low fabrication cost and intrinsic plasmonic flexibility of the presented systems.

Plasmonic color-graded nanosystems with achromatic sub-wavelength architectures for light filtering and advanced SERS detection

KAUST Repository

Proietti Zaccaria, Remo; Bisio, Francesco; Das, Gobind; Maidecchi, Giulia; Caminale, Michael; Vu, Chinh Duc; De Angelis, Francesco; Di Fabrizio, Enzo M.; Toma, Andrea; Canepa, Maurizio

2016-01-01

Plasmonic colour-graded systems are devices featuring a spatially variable plasmonic response over their surface. They are widely used as nanoscale colour filters; their typical size is small enough to allow integration with miniaturized electronic circuits paving the way to realize novel nanophotonic devices. Currently, most plasmonic colour-graded systems are intrinsically discrete, as their chromatic response exploits the tailored plasmon resonance of micro-architectures characterized by different size and/or geometry for each target colour. Here we report the realization of multifunctional plasmon-graded devices where continuously-graded chromatic response is achieved by smoothly tuning the composition of the resonator material while simultaneously maintaining an achromatic nanoscale geometry. The result is a new class of versatile materials: we show their application as plasmonic filters with a potential pixel size smaller than half of the exciting wavelength, but also as multiplexed surface-enhanced Raman spectroscopy (SERS) substrates. Many more implementations, like photovoltaic efficiency boosters or colour routers await, and will benefit from the low fabrication cost and intrinsic plasmonic flexibility of the presented systems.

Proceedings of the advanced coal-fired power systems `95 review meeting, Volume II

Energy Technology Data Exchange (ETDEWEB)

McDaniel, H.M.; Mollot, D.J.; Venkataraman, V.K.

1995-06-01

This report contains papers which were presented at the advanced coal-fired power sytems review meeting. This is volume II. Topics include: hot gas filter issues, hazardous air pollutants, sorbent development, and separation technologies. Individual papers were processed separately for the United States Department of Energy databases.

Hydrodynamic calculation of a filter washing in liquids type used in containment venting systems

International Nuclear Information System (INIS)

Reyes G, A. A.; Sainz M, E.; Ortiz V, J.

2015-09-01

From the nuclear accident of Chernobyl, the European nuclear power plants have chosen to install filters on the venting pipes of the containment, whose function is to help to mitigate the consequences of a severe accident, by controlled depressurization of the containment passively through a filtered venting of the containment system. These systems are designed to relieve the internal pressure of the containment by means of the deliberate opening of pressure relief devices, either a valve or rupture disc during a severe accident and be channeled to the filter unit. In this paper the hydraulic response of a filter system of gases washing by liquid is evaluated, due to this information is necessary to estimate the effect that has the pressure increase of the contention on the discharge capacity of the venting pipes. By simulation of computational of fluid dynamics with the programs: CAELINUX-2014 and OpenFOAM, the hydrodynamic characteristics of the Multi Venturi System for gases washing from the containment, which could be included in the general model of the venting pipe, were obtained. Representative models of the Venturi tubes of each concentric area that forming the washing system were generated; and using parametric calculations the average mass flow rate established through each venturi, depending on its size and depth in which it is located inside the tank was estimated. Also, the pressure and mass flow rate required to activate each concentric area depending on the pressure and mass load from the containment were calculated, to estimate the maximum flow that is established through the filter. Finally, the velocity profiles and the characteristic pressure at which each area operates as well as the pressure drop of local and global discharge also were calculated. (Author)

Development and evaluation of a plant-based air filter system for ...

African Journals Online (AJOL)

We investigated a novel plant-based air filter system for bacterial growth control. The volatile components released from the experimental plant (Cupressus macrocarpa) were used as the basis of the bacterial growth control and inhibition. We monitored the effect of light on the gas exhausted from the system, and we found ...

Determination of atmospheric iodine species using a system of specifically prepared filters and IDMS

International Nuclear Information System (INIS)

Gaebler, H.E.; Heumann, K.G.

1993-01-01

A system was developed which allowed the determination of four different atmospheric iodine species by preparing glass microfibre filters, which were arranged in consecutive order, in a specific way. Particulate iodine was collected by a particle filter, HI and I 2 by a NaOH impregnated filter, HOI was adsorbed on a TBAH impregnated filter and organoiodine was adsorbed on a filter loaded with activated charcoal. These behaviours were checked by extensive model experiments. Two or more filters of the same type were used in series to show the degree of collection of one iodine species. Two European samples, one of continental and one of marine origin, and two Antarctic samples were analysed by this filter system using isotope dilution mass spectrometry (IDMS) for quantification. The distribution pattern for the different iodine species is similar for the two European samples. Organoiodine is found to be the most abundant species whereas in Antarctica the HI/I 2 fraction is up to nearly 50% of the total iodine. The particulate iodine fraction is higher in Europe than in Antarctica, which is due to the low particle concentration in the remote area of Antarctica. The higher HI/I 2 and HOI fractions found at the North Sea compared with the continental sample indicate that the ocean is a primary source of these species. Concentrations in the range of (0.3-3.1) ngI/m 3 were analysed for particulate iodine, (0.4-1.3) ng I/m 3 for HI/I 2 , (0.2-1.8) ng I/m 3 for HOI and (0.4-7.6) ng I/m 3 for organoiodine. The detection limits varied with the variances of the blank values of the different filters and lay between 0.02 ng I/m 3 and 0.24 ng I/m 3 using sample volumes of 70 m 3 air. (orig.)

Rotation speed measurement for turbine governor: torsion filtering by using Kalman filter

International Nuclear Information System (INIS)

Houry, M.P.; Bourles, H.

1995-11-01

The rotation speed of a turbogenerator is disturbed by its shaft torsion. Obtaining a filtered measure of this sped a problem of a great practical importance for turbine governor. A good filtering of this speed must meet two requirements: it must cut frequencies of the shaft torsion oscillation and it must not reduce or delay the signal in the pass-band. i.e. at lower frequencies. At Electricite de France, the speed measure is used to set in motion the fast valving system as quickly as possible, after a short circuit close to the unit (to contribute to the stability) or after an islanding (to quickly reach a balance with the house load). It is difficult to satisfy these two requirements by using conventional filtering methods. The standard solution consists in a first order filter: at Electricite de France, its time constant is equal to 80 ms; We have decided to improve this filtering by designing a new filter which cuts the frequencies of the shaft torsion oscillation without reducing the bandwidth of the speed measure. If one uses conventional methods to obtain a band-stop filter (for instance a Butterworth, a Chebyshev or an elliptic band-stop filter),it is easy to obtain the desired magnitude but not a phase near zero in the whole pass-band. Therefore, we have chosen to design the filter by using Kalman's theory. The measurement noise is modeled as a colored one, generated by a very lightly damped system driven by a white noise. The resulting Kalman filter is an effective band-stop filter, whose phase nicely remains near zero in the whole pass-band. (authors). 13 refs., 12 figs

Design and Performance Evaluation of Sensors and Actuators for Advanced Optical Systems

Science.gov (United States)

Clark, Natalie

2011-01-01

Current state-of-the-art commercial sensors and actuators do not meet many of NASA s next generation spacecraft and instrument needs. Nor do they satisfy the DoD needs for satellite missions, especially micro/nano satellite missions. In an effort to develop advanced optical devices and instruments that meet mission requirements, NASA Langley recently completed construction of a new cleanroom housing equipment capable of fabricating high performance active optic and adaptive optic technologies including deformable mirrors, reconfigurable lenses (both refractive and diffractive), spectrometers, spectro-polarimeters, tunable filters and many other active optic devices. In addition to performance, these advanced optic technologies offer advantages in speed, size, weight, power consumption, and radiation tolerance. The active optic devices described in this paper rely on birefringent liquid crystal materials to alter either the phase or the polarization of the incoming light. Design considerations and performance evaluation results for various NASA applications are presented. Applications presented will include large space telescopes, optical communications, spacecraft windows, coronagraphs, and star trackers. Keywords: Photonics, Adaptive Optics, Tunable Filters, MEMs., MOEMs, Coronagraph, Star Tracker

Advanced optical manufacturing digital integrated system

Science.gov (United States)

Tao, Yizheng; Li, Xinglan; Li, Wei; Tang, Dingyong

2012-10-01

It is necessarily to adapt development of advanced optical manufacturing technology with modern science technology development. To solved these problems which low of ration, ratio of finished product, repetition, consistent in big size and high precision in advanced optical component manufacturing. Applied business driven and method of Rational Unified Process, this paper has researched advanced optical manufacturing process flow, requirement of Advanced Optical Manufacturing integrated System, and put forward architecture and key technology of it. Designed Optical component core and Manufacturing process driven of Advanced Optical Manufacturing Digital Integrated System. the result displayed effective well, realized dynamic planning Manufacturing process, information integration improved ratio of production manufactory.

Development of aerosol decontamination factor evaluation method for filtered containment venting system

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae bong; Kim, Sung Il; Jung, Jaehoon; Ha, Kwang Soon; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Fission products would be released from molten corium pools which are relocated into the lower plenum of reactor pressure vessel, on the concrete pit and in the core catcher. In addition, steam, hydrogen and noncondensable gases such as CO and CO2 are generated during the core damage progression due to loss of coolant and the molten core-concrete interaction. Consequently, the pressure inside the containment could be increased continuously. Filtered containment venting is one action to prevent an uncontrolled release of radioactive fission products caused by an overpressure failure of the containment. After the Fukushima-Daiichi accident which was demonstrated the containment failure, many countries to consider the implementation of filtered containment venting system(FCVS) on nuclear power plant where these are not currently applied. In general evaluation for FCVS is conducted to determine decontamination factor on several conditions (aerosol diameter, submergence depth, water temperature, gas flow, steam flow rate, pressure, operating time,...). It is essential to quantify the mass concentration before and after FCVS for decontamination factor. This paper presents the development of the evaluation facility for filtered containment venting system at KAERI and an experimental investigation for aerosol removal performance. Decontamination factor for the FCVS is determined by filter measurement. The result of the aerosol size distribution measurement shows the aerosol removal performance by an aerosol size.

Audit filters for improving processes of care and clinical outcomes in trauma systems.

Science.gov (United States)

Evans, Christopher; Howes, Daniel; Pickett, William; Dagnone, Luigi

2009-10-07

Traumatic injuries represent a considerable public health burden with significant personal and societal costs. The care of the severely injured patient in a trauma system progresses along a continuum that includes numerous interventions being provided by a multidisciplinary group of healthcare personnel. Despite the recent emphasis on quality of care in medicine, there has been little research to direct trauma clinicians and administrators on how optimally to monitor and improve upon the quality of care delivered within a trauma system. Audit filters are one mechanism for improving quality of care and are defined as specific clinical processes or outcomes of care that, when they occur, represent unfavorable deviations from an established norm and which prompt review and feedback. Although audit filters are widely utilized for performance improvement in trauma systems they have not been subjected to systematic review of their effectiveness. To determine the effectiveness of using audit filters for improving processes of care and clinical outcomes in trauma systems. Our search strategy included an electronic search of the Cochrane Injuries Group Specialized Register, the Cochrane EPOC Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 4), MEDLINE, PubMed, EMBASE, CINAHL, and ISI Web of Science: (SCI-EXPANDED and CPCI-S). We handsearched the Journal of Trauma, Injury, Annals of Emergency Medicine, Academic Emergency Medicine, and Injury Prevention. We searched two clinical trial registries: 1) The World Health Organization International Clinical Trials Registry Platform and, 2) Clinical Trials.gov. We also contacted content experts for further articles. The most recent electronic search was completed in December 2008 and the handsearch was completed up to February 2009. We searched for randomized controlled trials, controlled clinical trials, controlled before-and-after studies, and interrupted time series studies that used audit filters as an

Exponential L2-L∞ Filtering for a Class of Stochastic System with Mixed Delays and Nonlinear Perturbations

Directory of Open Access Journals (Sweden)

Zhaohui Chen

2013-01-01

Full Text Available The delay-dependent exponential L2-L∞ performance analysis and filter design are investigated for stochastic systems with mixed delays and nonlinear perturbations. Based on the delay partitioning and integral partitioning technique, an improved delay-dependent sufficient condition for the existence of the L2-L∞ filter is established, by choosing an appropriate Lyapunov-Krasovskii functional and constructing a new integral inequality. The full-order filter design approaches are obtained in terms of linear matrix inequalities (LMIs. By solving the LMIs and using matrix decomposition, the desired filter gains can be obtained, which ensure that the filter error system is exponentially stable with a prescribed L2-L∞ performance γ. Numerical examples are provided to illustrate the effectiveness and significant improvement of the proposed method.

Advanced Agriculture system

Directory of Open Access Journals (Sweden)

Shrinivas R. Zanwar

2012-05-01

Full Text Available This article addresses the advanced system which improves agriculture processes like cultivation on ploughed land, based on robotic platform. We have developed a robotic vehicle having four wheels and steered by DC motor. The advanced autonomous system architecture gives us the opportunity to develop a complete new range of agricultural equipment based on small smart machines. The machine will cultivate the farm by considering particular rows and specific column at fixed distance depending on crop. The obstacle detection problem will also be considered, sensed by infrared sensor. The whole algorithm, calculation, processing, monitoring are designed with motors & sensor interfaced with microcontroller. The result obtained through example activation unit is also presented. The dc motor simulation with feedforward and feedback technique shows precise output. With the help of two examples, a DC motor and a magnetic levitation system, the use of MATLAB and Simulink for modeling, analysis and control is designed.

Biologically active filters - An advanced water treatment process for contaminants of emerging concern.

Science.gov (United States)

Zhang, Shuangyi; Gitungo, Stephen W; Axe, Lisa; Raczko, Robert F; Dyksen, John E

2017-05-01

With the increasing concern of contaminants of emerging concern (CECs) in source water, this study examines the hypothesis that existing filters in water treatment plants can be converted to biologically active filters (BAFs) to treat these compounds. Removals through bench-scale BAFs were evaluated as a function of media, granular activated carbon (GAC) and dual media, empty bed contact time (EBCT), and pre-ozonation. For GAC BAFs, greater oxygen consumption, increased pH drop, and greater dissolved organic carbon removal normalized to adenosine triphosphate (ATP) were observed indicating increased microbial activity as compared to anthracite/sand dual media BAFs. ATP concentrations in the upper portion of the BAFs were as much as four times greater than the middle and lower portions of the dual media and 1.5 times greater in GAC. Sixteen CECs were spiked in the source water. At an EBCT of 18 min (min), GAC BAFs were highly effective with overall removals greater than 80% without pre-ozonation; exceptions included tri(2-chloroethyl) phosphate and iopromide. With a 10 min EBCT, the degree of CECs removal was reduced with less than half of the compounds removed at greater than 80%. The dual media BAFs showed limited CECs removal with only four compounds removed at greater than 80%, and 10 compounds were reduced by less than 50% with either EBCT. This study demonstrated that GAC BAFs with and without pre-ozonation are an effective and advanced technology for treating emerging contaminants. On the other hand, pre-ozonation is needed for dual media BAFs to remove CECs. The most cost effective operating conditions for dual media BAFs were a 10 min EBCT with the application of pre-ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Game Theoretic Fault Detection Filter

Science.gov (United States)

Chung, Walter H.; Speyer, Jason L.

1995-01-01

The fault detection process is modelled as a disturbance attenuation problem. The solution to this problem is found via differential game theory, leading to an H(sub infinity) filter which bounds the transmission of all exogenous signals save the fault to be detected. For a general class of linear systems which includes some time-varying systems, it is shown that this transmission bound can be taken to zero by simultaneously bringing the sensor noise weighting to zero. Thus, in the limit, a complete transmission block can he achieved, making the game filter into a fault detection filter. When we specialize this result to time-invariant system, it is found that the detection filter attained in the limit is identical to the well known Beard-Jones Fault Detection Filter. That is, all fault inputs other than the one to be detected (the "nuisance faults") are restricted to an invariant subspace which is unobservable to a projection on the output. For time-invariant systems, it is also shown that in the limit, the order of the state-space and the game filter can be reduced by factoring out the invariant subspace. The result is a lower dimensional filter which can observe only the fault to be detected. A reduced-order filter can also he generated for time-varying systems, though the computational overhead may be intensive. An example given at the end of the paper demonstrates the effectiveness of the filter as a tool for fault detection and identification.

A study of the effect of the position of an edge filter within a ratiometric wavelength measurement system

International Nuclear Information System (INIS)

Wu, Qiang; Wang, Pengfei; Semenova, Yuliya; Farrell, Gerald

2010-01-01

The effect of the position of an edge filter within a ratiometric wavelength measurement system was investigated based on three cases: (1) the reflected fibre Bragg grating (FBG) signal passes through both the reference arm and the edge filter arm, (2) the reflected FBG signal is connected directly to the edge filter arm and does not pass through the reference arm, (3) the edge filter sits in line with the FBG and thus the source power is filtered prior to reaching the FBG. Both numerical simulations and experimental results show that cases 1 and 2 have similar system performance whilst case 3 is the best arrangement which offers the highest wavelength resolution

The Advanced Technology Operations System: ATOS

Science.gov (United States)

Kaufeler, J.-F.; Laue, H. A.; Poulter, K.; Smith, H.

1993-01-01

Mission control systems supporting new space missions face ever-increasing requirements in terms of functionality, performance, reliability and efficiency. Modern data processing technology is providing the means to meet these requirements in new systems under development. During the past few years the European Space Operations Centre (ESOC) of the European Space Agency (ESA) has carried out a number of projects to demonstrate the feasibility of using advanced software technology, in particular, knowledge based systems, to support mission operations. A number of advances must be achieved before these techniques can be moved towards operational use in future missions, namely, integration of the applications into a single system framework and generalization of the applications so that they are mission independent. In order to achieve this goal, ESA initiated the Advanced Technology Operations System (ATOS) program, which will develop the infrastructure to support advanced software technology in mission operations, and provide applications modules to initially support: Mission Preparation, Mission Planning, Computer Assisted Operations, and Advanced Training. The first phase of the ATOS program is tasked with the goal of designing and prototyping the necessary system infrastructure to support the rest of the program. The major components of the ATOS architecture is presented. This architecture relies on the concept of a Mission Information Base (MIB) as the repository for all information and knowledge which will be used by the advanced application modules in future mission control systems. The MIB is being designed to exploit the latest in database and knowledge representation technology in an open and distributed system. In conclusion the technological and implementation challenges expected to be encountered, as well as the future plans and time scale of the project, are presented.

Advanced walling systems

CSIR Research Space (South Africa)

De Villiers, A

2010-01-01

Full Text Available The question addressed by this chapter is: How should advanced walling systems be planned, designed, built, refurbished, and end their useful lives, to classify as smart, sustainable, green or eco-building environments?...

Improved Minimum Entropy Filtering for Continuous Nonlinear Non-Gaussian Systems Using a Generalized Density Evolution Equation

Directory of Open Access Journals (Sweden)

Jinliang Xu

2013-06-01

Full Text Available This paper investigates the filtering problem for multivariate continuous nonlinear non-Gaussian systems based on an improved minimum error entropy (MEE criterion. The system is described by a set of nonlinear continuous equations with non-Gaussian system noises and measurement noises. The recently developed generalized density evolution equation is utilized to formulate the joint probability density function (PDF of the estimation errors. Combining the entropy of the estimation error with the mean squared error, a novel performance index is constructed to ensure the estimation error not only has small uncertainty but also approaches to zero. According to the conjugate gradient method, the optimal filter gain matrix is then obtained by minimizing the improved minimum error entropy criterion. In addition, the condition is proposed to guarantee that the estimation error dynamics is exponentially bounded in the mean square sense. Finally, the comparative simulation results are presented to show that the proposed MEE filter is superior to nonlinear unscented Kalman filter (UKF.

Development of circular filters for active facilities

International Nuclear Information System (INIS)

Pratt, R.P.

1986-01-01

An assessment of problems associated with remote handling, changing and disposal of filters suggested that significant improvements to filtration systems could be made if circular geometries were adopted in place of conventional systems. Improved systems have been developed and are now available for a range of applications and air flow rates. Where primary filters are installed within the active cell or cave, circular filters incorporating a lip seal have been developed which enable the filters to be sealed into the facility without recourse to clamping. For smaller cells, a range of push-through filter change systems have been developed, the principal feature being that the filter is passed into the housing from the clean side, but transferred from the housing directly into the cell for subsequent disposal. For plant room applications, circular bag change canister systems have been developed which ease the sealing and bag change operation. Such systems have a rated air flow of up to 3000 m 3 /h whilst still allowing ultimate disposal via the 200 litre waste drum route without prior volume reduction of the filter inserts. (author)

40 CFR 141.564 - My system practices lime softening-is there any special provision regarding my individual filter...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false My system practices lime softening-is... People Individual Filter Turbidity Requirements § 141.564 My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring? If your system utilizes lime...

Generalized design of high performance shunt active power filter with output LCL filter

DEFF Research Database (Denmark)

Tang, Yi; Loh, Poh Chiang; Wang, Peng

2012-01-01

parameters, interactions between resonance damping and harmonic compensation, bandwidth design of the closed-loop system, and active damping implementation with fewer current sensors. These described design concerns, together with their generalized design procedure, are applied to an analytical example......This paper concentrates on the design, control, and implementation of an LCL-filter-based shunt active power filter (SAPF), which can effectively compensate for harmonic currents produced by nonlinear loads in a three-phase three-wire power system. With an LCL filter added at its output...

A tool for filtering information in complex systems

OpenAIRE

Tumminello, M.; Aste, T.; Di Matteo, T.; Mantegna, R. N.

2005-01-01

We introduce a technique to filter out complex data sets by extracting a subgraph of representative links. Such a filtering can be tuned up to any desired level by controlling the genus of the resulting graph. We show that this technique is especially suitable for correlation-based graphs, giving filtered graphs that preserve the hierarchical organization of the minimum spanning tree but containing a larger amount of information in their internal structure. In particular in the case of planar...

WE-DE-207B-08: Towards Standardization of X-Ray Filters in Digital Mammography-Enabled Breast Tomosynthesis Systems

International Nuclear Information System (INIS)

Shrestha, S; Vedantham, S; Karellas, A

2016-01-01

Purpose: In digital breast tomosynthesis (DBT) systems capable of digital mammography (DM), Al filters are used during DBT and K-edge filters during DM. The potential for standardizing the x-ray filters with Al, instead of K-edge filters, was investigated with intent to reduce exposure duration and to promote a simpler system design. Methods: Analytical computations of the half-value thickness (HVT) and the photon fluence per mAs (photons/mm2/mAs) for K-edge filters (50µm Rh; 50µm Ag) were compared with Al filters of varying thickness. Two strategies for matching the HVT from K-edge and Al filtered spectra were investigated: varying the kVp for fixed Al thickness, or varying the Al thickness at matched kVp. For both strategies, Al filters were an order of magnitude thicker than K-edge filters. Hence, Monte Carlo simulations were conducted with the GEANT4 toolkit to determine if the scatter-to-primary ratio (SPR) and the point spread function of scatter (scatter PSF) differed between Al and K-edge filters. Results: Results show the potential for replacing currently used Kedge filters with Al. For fixed Al thickness (700µm), ±1 kVp and +(1–3) kVp change, matched HVT of Rh and Ag filtered spectra. At matched kVp, Al thickness range (650,750)µm and (750,860)µm matched the HVT from Rh and Ag filtered spectra. Photon fluence/mAs with Al filters were 1.5–2.5 times higher, depending on kVp and Al thickness, compared to K-edge filters. Although Al thickness was an order higher than K-edge filters, neither the SPR nor the scatter PSF differed from K-edge filters. Conclusion: The use of Al filters for digital mammography is potentially feasible. The increased fluence/mAs with Al could decrease exposure duration for the combined DBT+DM exam and simplify system design. Effect of x-ray spectrum change due to Al filtration on radiation dose, signal, noise, contrast and related metrics are being investigated. Funding support: Supported in part by NIH R21CA176470 and R01

WE-DE-207B-08: Towards Standardization of X-Ray Filters in Digital Mammography-Enabled Breast Tomosynthesis Systems

Energy Technology Data Exchange (ETDEWEB)

Shrestha, S; Vedantham, S; Karellas, A [University of Massachusetts Medical School, Worcester, MA (United States)

2016-06-15

Purpose: In digital breast tomosynthesis (DBT) systems capable of digital mammography (DM), Al filters are used during DBT and K-edge filters during DM. The potential for standardizing the x-ray filters with Al, instead of K-edge filters, was investigated with intent to reduce exposure duration and to promote a simpler system design. Methods: Analytical computations of the half-value thickness (HVT) and the photon fluence per mAs (photons/mm2/mAs) for K-edge filters (50µm Rh; 50µm Ag) were compared with Al filters of varying thickness. Two strategies for matching the HVT from K-edge and Al filtered spectra were investigated: varying the kVp for fixed Al thickness, or varying the Al thickness at matched kVp. For both strategies, Al filters were an order of magnitude thicker than K-edge filters. Hence, Monte Carlo simulations were conducted with the GEANT4 toolkit to determine if the scatter-to-primary ratio (SPR) and the point spread function of scatter (scatter PSF) differed between Al and K-edge filters. Results: Results show the potential for replacing currently used Kedge filters with Al. For fixed Al thickness (700µm), ±1 kVp and +(1–3) kVp change, matched HVT of Rh and Ag filtered spectra. At matched kVp, Al thickness range (650,750)µm and (750,860)µm matched the HVT from Rh and Ag filtered spectra. Photon fluence/mAs with Al filters were 1.5–2.5 times higher, depending on kVp and Al thickness, compared to K-edge filters. Although Al thickness was an order higher than K-edge filters, neither the SPR nor the scatter PSF differed from K-edge filters. Conclusion: The use of Al filters for digital mammography is potentially feasible. The increased fluence/mAs with Al could decrease exposure duration for the combined DBT+DM exam and simplify system design. Effect of x-ray spectrum change due to Al filtration on radiation dose, signal, noise, contrast and related metrics are being investigated. Funding support: Supported in part by NIH R21CA176470 and R01

Development of high efficiency filtered containment venting system by using AgX

International Nuclear Information System (INIS)

Narabayashi, Tadashi; Fujii, Yasuhiro; Chiba, Go; Tsuji, Masashi; Ishii, Tasuku

2014-01-01

Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc. In case of Europe, it had already installed the heat removal system and filtered containment venting system (FCVS) from the lessons of TMI and Chernobyl Accidents. Decay heat removal system and CV spray cooling system with FCVS are ensured by using mobile generators and heat exchangers to keep the ultimate heat sink even in any natural disaster, such as large earthquake, big tsunami, sudden flooding etc. In this paper we introduce high decontamination factor FCVS that used Silver Zeolite named AgX, developed by Rasa Industries, Ltd. Hokkaido University has tested wet type FCVS using venturi scrubber in water pool and dry type FCVS using metallic filter for 1st stage, and AgX for 2nd stage. Since the AgX needs super heat steam, it is possible to heat up steam by heat exchanger. It is confirmed by TRAC analysis. (author)

40 CFR 141.553 - My system practices lime softening-is there any special provision regarding my combined filter...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false My system practices lime softening-is... Filter Effluent Requirements § 141.553 My system practices lime softening—is there any special provision regarding my combined filter effluent? If your system practices lime softening, you may acidify...

Electrically heated particulate filter restart strategy

Science.gov (United States)

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2011-07-12

A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

Characterization Of Improved Binary Phase-Only Filters In A Real-Time Coherent Optical Correlation System

Science.gov (United States)

Flannery, D.; Keller, P.; Cartwright, S.; Loomis, J.

1987-06-01

Attractive correlation system performance potential is possible using magneto-optic spatial light modulators (SLM) to implement binary phase-only reference filters at high rates, provided the correlation performance of such reduced-information-content filters is adequate for the application. In the case studied here, the desired filter impulse response is a rectangular shape, which cannot be achieved with the usual binary phase-only filter formulation. The correlation application problem is described and techniques for synthesizing improved filter impulse response are considered. A compromise solution involves the cascading of a fixed amplitude-only weighting mask with the binary phase-only SLM. Based on simulations presented, this approach provides improved impulse responses and good correlation performance, while retaining the critical feature of real-time variations of the size, shape, and orientation of the rectangle by electronic programming of the phase pattern in the SLM. Simulations indicate that, for at least one very challenging input scene clutter situation, these filters provide higher correlation signal-to-noise than does "ideal" correlation, i.e. using a perfect rectangle filter response.

Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

Directory of Open Access Journals (Sweden)

Baofeng Wang

Full Text Available Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

International Nuclear Information System (INIS)

Winegardner, W.K.

1993-08-01

A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission's (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants

Rotor-System Log-Decrement Identification Using Short-Time Fourier-Transform Filter

Directory of Open Access Journals (Sweden)

Qihang Li

2015-01-01

Full Text Available With the increase of the centrifugal compressor capability, such as large scale LNG and CO2 reinjection, the stability margin evaluation is crucial to assure the compressor work in the designed operating conditions in field. Improving the precision of parameter identification of stability is essential and necessary as well. Based on the time-varying characteristics of response vibration during the sine-swept process, a short-time Fourier transform (STFT filter was introduced to increase the signal-noise ratio and improve the accuracy of the estimated stability parameters. A finite element model was established to simulate the sine-swept process, and the simulated vibration signals were used to study the filtering effect and demonstrate the feasibility to identify the stability parameters by using Multiple-Input and Multiple-Output system identification method that combines the prediction error method and instrumental variable method. Simulation results show that the identification method with STFT filter improves the estimated accuracy much well and makes the curves of frequency response function clearer. Experiment was carried out on a test rig as well, which indicates the identification method is feasible in stability identification, and the results of experiment indicate that STFT filter works very well.

Examination of cryogenic filters for multistage RF filtering in ultralow temperature experiments

Science.gov (United States)

Zavyalov, V. V.; Chernyaev, S. A.; Shein, K. V.; Shukaleva, A. G.; Arutyunov, K. Yu

2018-03-01

Cryo-filters are essential while studying electronic properties of nanoscale structures at very low temperatures. In this report we present the simple measuring methodology and experimental impedance characteristics of customized lumped filters cooled down to 4.2K in the 10 Hz-500 MHz frequency range. In particular, we tested the home-made permalloy-core RL filters, the MurataTMChip Ferrite Bead filter, and the ToshibaTMAmobeadsTMcores. We use the high-frequency generalization of four-terminal sensing method to account for the wiring retardation effects, which are important when working with ultralow temperature systems.

First application of hollow fiber filter for PWR condensate polishing

International Nuclear Information System (INIS)

Tsuda, S.; Otoha, K.; Takiguchi, H.

2002-01-01

In Tsuruga Unit-2 (PWR 1160 MWe commenced commercial operation in 1987), current procedure for secondary system clean-up before start-up had prolonged outage time and had consumed a huge amount of de-ionized (DI) water. In addition, iron oxide in condensate had accelerated the degradation of condensate demineralizer (CD) resin. The corrosion product of iron could also influence the secondary side corrosion of steam generator (SG) tubing if it intruded into SG through CD. To solve these problems, Japan Atomic Power Company (JAPC) decided to introduce hollow fiber filter (HFF) type condensate filter into Tsuruga-2, as the first application to PWR in the world. Because of retro-fitted HFF in Tsuruga Unit-2, limitations for installation space and flow resistance in condensate system and cost reduction required new design for compact and low differential pressure system and for long life filter module. JAPC and ORGANO assessed methodologies to achieve these goals. An advanced HFF system, including a newly developed compact HFF module design, was installed at Tsuruga Unit-2 in 1997 based on the assessment. During the 5 years since the installation, the HFF system has provided excellent crud removal that enables to shorten the outage period and to reduce DI water consumption drastically. Stable differential pressure (dP) trend of the HFF system indicates an expected module life of more than 7 years, with backwash cleaning required only 2 or 3 times per year. In addition to providing the expected operating cost reduction and improved SG tube integrity, numerous additional benefits have resulted from the retrofit. (authors)

Performance of drippers in two filtering systems using sewage treatment effluent

Directory of Open Access Journals (Sweden)

Alexandre B. Dalri

Full Text Available ABSTRACT The objective of this study was to evaluate the performance of three models of drippers using treated sewage effluent, pure and diluted, and two types of filters, screen and disc. The treated sewage effluent used in the experiment was collected from the city’s treatment plant. The experiment included 12 lateral lines with three types of emitters to apply pure (100% and diluted (50% effluent filtered by screen and disc filters. The combination of those factors set the treatments: T1 (50% effluent diluted in fresh water filtered by a screen filter; T2 (50% effluent diluted in fresh water filtered by a disc filter; T3 (pure effluent filtered by a screen filter; T4 (pure effluent filtered by a disc filter. The results showed that the flat type emitter is less sensitive to clogging, the disc filter is the most suitable to prevent clogging and the use of pure or diluted sewage effluent increases the drippers’ flow rate coefficient of variation.

Data management system advanced development

Science.gov (United States)

Douglas, Katherine; Humphries, Terry

1990-01-01

The Data Management System (DMS) Advanced Development task provides for the development of concepts, new tools, DMS services, and for the testing of the Space Station DMS hardware and software. It also provides for the development of techniques capable of determining the effects of system changes/enhancements, additions of new technology, and/or hardware and software growth on system performance. This paper will address the built-in characteristics which will support network monitoring requirements in the design of the evolving DMS network implementation, functional and performance requirements for a real-time, multiprogramming, multiprocessor operating system, and the possible use of advanced development techniques such as expert systems and artificial intelligence tools in the DMS design.

A DSP-Based Beam Current Monitoring System for Machine Protection Using Adaptive Filtering

International Nuclear Information System (INIS)

J. Musson; H. Dong; R. Flood; C. Hovater; J. Hereford

2001-01-01

The CEBAF accelerator at Jefferson Lab is currently using an analog beam current monitoring (BCM) system for its machine protection system (MPS), which has a loss accuracy of 2 micro-amps. Recent burn-through simulations predict catastrophic beam line component failures below 1 micro-amp of loss, resulting in a blind spot for the MPS. Revised MPS requirements target an ultimate beam loss accuracy of 250 nA. A new beam current monitoring system has been developed which utilizes modern digital receiver technology and digital signal processing concepts. The receiver employs a direct-digital down converter integrated circuit, mated with a Jefferson Lab digital signal processor VME card. Adaptive filtering is used to take advantage of current-dependent burn-through rates. Benefits of such a system include elimination of DC offsets, generic algorithm development, extensive filter options, and interfaces to UNIX-based control systems

Factors Influencing HEPA Filter Performance

International Nuclear Information System (INIS)

Parsons, M.S.; Waggoner, Ch.A.

2009-01-01

Properly functioning HEPA air filtration systems depend on a variety of factors that start with the use of fully characterized challenge conditions for system design and then process control during operation. This paper addresses factors that should be considered during the design phase as well as operating parameters that can be monitored to ensure filter function and lifetime. HEPA filters used in nuclear applications are expected to meet design, fabrication, and performance requirements set forth in the ASME AG-1 standard. The DOE publication Nuclear Air Cleaning Handbook (NACH) is an additional guidance document for design and operation HEPA filter systems in DOE facilities. These two guidelines establish basic maximum operating parameters for temperature, maximum aerosol particle size, maximum particulate matter mass concentration, acceptable differential pressure range, and filter media velocity. Each of these parameters is discussed along with data linking variability of each parameter with filter function and lifetime. Temporal uncertainty associated with gas composition, temperature, and absolute pressure of the air flow can have a direct impact on the volumetric flow rate of the system with a corresponding impact on filter media velocity. Correlations between standard units of flow rate (standard meters per minute or cubic feet per minute) versus actual units of volumetric flow rate are shown for variations in relative humidity for a 70 deg. C to 200 deg. C temperature range as an example of gas composition that, uncorrected, will influence media velocity. The AG-1 standard establishes a 2.5 cm/s (5 feet per minute) ceiling for media velocities of nuclear grade HEPA filters. Data are presented that show the impact of media velocities from 2.0 to 4.0 cm/s media velocities (4 to 8 fpm) on differential pressure, filter efficiency, and filter lifetime. Data will also be presented correlating media velocity effects with two different particle size

Study the velocity and pressure exerted in front of the filter surface in the kitchen hood system by using ANSYS

Science.gov (United States)

Asmuin, Norzelawati; Pairan, M. Rasidi; Isa, Norasikin Mat; Sies, Farid

2017-04-01

Commercial kitchen hood ventilation system is a device used to capture and filtered the plumes from cooking activities in the kitchen area. Nowadays, it is very popular in the industrial sector such as restaurant and hotel to provide hygiene food. This study focused at the KSA filter part which installed in the kitchen hood system, the purpose of this study is to identify the critical region which indicated by observing the velocity and pressure of plumes exerted at of KSA filter. It is important to know the critical location of the KSA filter in order to install the nozzle which will helps increase the filtration effectiveness. The ANSYS 16.1 (FLUENT) software as a tool used to simulate the kitchen hood systems which consist of KSA filter. The commercial kitchen hood system model has a dimension 700 mm width, 1600 mm length and 555 mm height. The system has two inlets and one outlet. The velocity of the plumes is set to be 0.235m/s and the velocity of the inlet capture jet is set to be 1.078m/s. The KSA filter is placed 45 degree from the y axis. The result shows the plumes has more tendency flowing pass through at the bottom part of KSA filter.

Advanced fire information system

CSIR Research Space (South Africa)

Frost, PE

2007-01-01

Full Text Available The South African Advanced Fire Information System (AFIS) is the first near real-time satellite-based fire monitoring system in Africa. It was originally developed for, and funded by, the electrical power utility Eskom, to reduce the impact of wild...

Rapid antibiotic efficacy screening with aluminum oxide nanoporous membrane filter-chip and optical detection system.

Science.gov (United States)

Tsou, Pei-Hsiang; Sreenivasappa, Harini; Hong, Sungmin; Yasuike, Masayuki; Miyamoto, Hiroshi; Nakano, Keiyo; Misawa, Takeyuki; Kameoka, Jun

2010-09-15

We have developed a filter-chip and optical detection system for rapid antibiotic efficacy screening. The filter-chip consisted of a 1-mL reservoir and an anodic aluminum oxide (AAO) nanoporous membrane. Sample solution with liquid growth media, bacteria, and antibiotics was incubated in the reservoir for a specific period of time. The number of live bacteria on the surface of membrane was counted after the incubation with antibiotics and filtration. Using this biosensing system, we have demonstrated a 1-h antibiotic screening for patients' clinical samples, significantly faster than the conventional antibiotic susceptibility tests that typically take more than 24h. This rapid screening nature makes the filter-chip and detection system ideal for tailoring antibiotic treatment to individual patients by reducing the microbial antibiotic resistance, and improving the survival rate for patients suffering from postoperative infections. Published by Elsevier B.V.

Extended Kalman filtering for model-based sensor fusion in robotics

International Nuclear Information System (INIS)

Fujii, Yuji; Wehe, D.K.; Lee, J.C.

1990-01-01

Remote surveillance and maintenance in advanced nuclear power plants will benefit from the increased utilization of mobile robotic systems. For these robotic systems to function most effectively in hazardous environments, they should be able to make decisions and take necessary actions with minimal human supervision. To accomplish this, the robot must be able to construct an accurate model of the power plant environment from diverse sensory data and a priori maps. In this paper, the authors demonstrate how a recursive parameter estimation technique known as Kalman filtering can integrate noisy data from various sensors to construct a consistent representation of the sensed environment