Theoretical investigation of pressure drop in combined cyclone and fabric filter systems
Dirgo, John A.; Cooper, Douglas W.
Computer simulations were conducted to investigate potential pressure drop reductions obtainable by combining cyclones, as pre-collectors, with fabric filters. The Leith-Licht model was used to characterize cyclone emissions and the specific resistance ( K2) of the fabric filter dust cake was calculated from an empirical correlation. Several important dimensionless groups were identified and evaluated. One group, the product of the ratio of the dust cake specific resistances expected with and without the cyclone and the mass penetration of the cyclone, ( K2/ K2) Pn, indicates whether a pressure drop reduction is possible. A correlation was developed for this group as a function of the size properties of the inlet dust (particle mass median diameter and geometric standard deviation) and the cyclone particle cut diameter. Expressions were derived for the break-even time, the duration of filtration with the cyclone needed to show a pressure drop reduction in comparison with filtration without the cyclone. It is shown that in previously reported experiments and simulations indicating an advantage for the combined cyclone-fabric filter system, filtration cycles were typically longer than the break-even time; those showing no improvement typically had filtration times shorter than the break-even time.
Filter Fabrics for Airport Drainage.
1979-09-01
Systems for *r- field Pavements," Harry R. Cedergren . d. "Development of Guidelines for the Design of Subsurfac( Drainage Systems for Highway Pavement...Structural 4Sectic s," H. R. Cedergren , J. A. Arman, and K. H. O’Brien. e. Drainage of Highway and Airfield Pavements, Harry R. Cedergren .> Five...by Cedergren (974).5 Additionally, several references were used, particularly those describing experimental anu construction prolects using filter
Numerical simulation of large fabric filter
Directory of Open Access Journals (Sweden)
Kovařík Petr
2012-04-01
Full Text Available Fabric filters are used in the wide range of industrial technologies for cleaning of incoming or exhaust gases. To achieve maximal efficiency of the discrete phase separation and long lifetime of the filter hoses, it is necessary to ensure uniform load on filter surface and to avoid impacts of heavy particles with high velocities to the filter hoses. The paper deals with numerical simulation of two phase flow field in a large fabric filter. The filter is composed of six chambers with approx. 1600 filter hoses in total. The model was simplified to one half of the filter, the filter hoses walls were substituted by porous zones. The model settings were based on experimental data, especially on the filter pressure drop. Unsteady simulations with different turbulence models were done. Flow field together with particles trajectories were analyzed. The results were compared with experimental observations.
Numerical simulation of large fabric filter
Sedláček, Jan; Kovařík, Petr
2012-04-01
Fabric filters are used in the wide range of industrial technologies for cleaning of incoming or exhaust gases. To achieve maximal efficiency of the discrete phase separation and long lifetime of the filter hoses, it is necessary to ensure uniform load on filter surface and to avoid impacts of heavy particles with high velocities to the filter hoses. The paper deals with numerical simulation of two phase flow field in a large fabric filter. The filter is composed of six chambers with approx. 1600 filter hoses in total. The model was simplified to one half of the filter, the filter hoses walls were substituted by porous zones. The model settings were based on experimental data, especially on the filter pressure drop. Unsteady simulations with different turbulence models were done. Flow field together with particles trajectories were analyzed. The results were compared with experimental observations.
Meng, Qinghua; Chen, Sihai; Lai, Jianjun; Huang, Ying; Sun, Zhenjun
2015-08-01
This paper demonstrates the design and fabrication of a 128×128 micro-electro-mechanical systems Fabry-Perot (F-P) cavity filter array, which can be applied for the hyperspectral imager. To obtain better mechanical performance of the filters, F-P cavity supporting structures are analyzed by multi-physics finite element modeling. The simulation results indicate that Z-arm is the key component of the structure. The F-P cavity array with Z-arm structures was also fabricated. The experimental results show excellent parallelism of the bridge deck, which agree with the simulation results. A conclusion is drawn that Z-arm supporting structures are important to hyperspectral imaging system, which can achieve a large tuning range and high fill factor compared to straight arm structures. The filter arrays have the potential to replace the traditional dispersive element.
Design and fabrication of broadband rugate filter
Institute of Scientific and Technical Information of China (English)
Zhaug Jun-Chao; Fang Ming; Shao Yu-Chuan; Jin Yun-Xia; He Hong-Bo
2012-01-01
The design and the deposition of a rugate filter for broadband applications are discussed.The bandwidth is extended by increasing the rugate period continuously with depth.The width and the smoothness of the reflection band with the distribution of the periods are investigated.The improvement of the steepness of the stopband edges and the suppression of the side lobes in the transmission zone are realized by adding two apodized rugate structures with fixed periods at the external broadband rngate filter interfaces.The rapidly alternating deposition technology is used to fabricate a rugate filter sample.The measured transmission spectrum with a reflection bandwidth of approximately 505 nm is close to that of the designed broadband rugate filter except a transmittance peak in the stopband.Based on the analysis of the cross-sectional scanning electron microscopic image of the sample,it is found that the transmission peak is most likely to be caused by the instability of the deposition rate.
Non-traditional Machining Techniques for Fabricating Metal Aerospace Filters
Institute of Scientific and Technical Information of China (English)
Wang Wei; Zhu Di; D.M.Allen; H.J.A.Almondb
2008-01-01
Thanks to recent advances in manufacturing technology, aerospace system designers have many more options to fabricate high-quality, low-weight, high-capacity, cost-effective filters. Aside from traditional methods such as stamping, drilling and milling,many new approaches have been widely used in filter-manufacturing practices on account of their increased processing abilities. However, the restrictions on costs, the need for studying under stricter conditions such as in aggressive fluids, the complicity in design, the workability of materials, and others have made it difficult to choose a satisfactory method from the newly developed processes, such as,photochemical machining (PCM), photo electroforming (PEF) and laser beam machining (LBM) to produce small, inexpensive, lightweight aerospace filters. This article appraises the technical and economical viability of PCM, PEF, and LBM to help engineers choose the fittest approach to turn out aerospace filters.
Energy Technology Data Exchange (ETDEWEB)
Morris, W.J.; Gansley, R.R.; Schaddell, J.G.
1999-07-01
This paper describes the design, initial operation and performance testing of a Dry Flue Gas Desulfurization (DFGD) and Modular Pulse Jet Fabric Filter (MPJFF) system installed at Cokenergy's site in East Chicago, Indiana. The combined flue gas from the sixteen (16) waste heat recovery boilers is processed by the system to control emissions of sulfur dioxide and particulates. These boilers recover energy from coke oven off gas from Indiana Harbor Coke Company's coke batteries. The DFGD system consists of two 100% capacity absorbers. Each absorber vessel uses a single direct drive rotary atomizer to disperse the lime slurry for SO{sub 2} control. The MPJFF consists of thirty two (32) modules arranged in twin sixteen-compartment (16) units. The initial start up of the DFGD/MPJFF posed special operational issues due to the low initial gas flows through the system as the four coke oven batteries were cured and put in service for the first time. This occurred at approximately monthly intervals beginning in March 1998. A plan was implemented to perform a staged startup of the DFGD and MPJFF to coincide with the staged start up of the coke batteries and waste heat boilers. Operational issues that are currently being addressed include reliability of byproduct removal. Performance testing was conducted in August and September 1998 at the inlet of the system and the outlet stack. During these tests, particulate, SO{sub 2}, SO{sub 3}, and HCI emissions were measured simultaneously at the common DFGD inlet duct and the outlet stack. Measurements were also taken for average lime, water, and power consumption during the tests as well as system pressure losses. These results showed that all guarantee parameters were achieved during the test periods. The initial operation and performance testing are described in this paper.
FABRIC QUALITY CONTROL SYSTEMS
Directory of Open Access Journals (Sweden)
Özlem KISAOĞLU
2006-02-01
Full Text Available Woven fabric quality depends on yarn properties at first, then weaving preparation and weaving processes. Defect control of grey and finished fabric is done manually on the lighted tables or automatically. Fabrics can be controlled by the help of the image analysis method. In image system the image of fabrics can be digitized by video camera and after storing controlled by the various processing. Recently neural networks, fuzzy logic, best wavelet packet model on automatic fabric inspection are developed. In this study the advantages and disadvantages of manual and automatic, on-line fabric inspection systems are given comparatively.
Design and fabrication of magnetic coolant filter
Prashanth, B. N.
2017-07-01
Now a day's use of coolants in industry has become dominant because of high production demands. Coolants not only help in speeding up the production but also provide many advantages in the metal working operation. As the consumption of coolants is very high a system is badly in need, so as to recirculate the used coolant. Also the amount of hazardous waste generated by industrial plants has become an increasingly costly problem for the manufactures and an additional stress on the environment. Since the purchase and disposal of the spent cutting fluids is becoming increasingly expensive, fluid recycling is a viable option for minimizing the cost. Separation of metallic chips from the coolants by using magnetic coolant separation has proven a good management and maintenance of the cutting fluid. By removing the metallic chips, the coolant life is greatly extended, increases the machining quality and reduces downtime. Above being the case, a magnetic coolant filter is developed which utilizes high energy permanent magnets to develop a dense magnetic field along a narrow flow path into which the contaminated coolant is directed. The ferromagnetic particles captured and aligned by the dense magnetic field, from the efficient filter medium. This enables the unit to remove ferromagnetic particles from the coolant. Magnetic coolant filters use the principle of magnetic separation to purify the used coolant. The developed magnetic coolant separation has the capability of purifying 40 litres per minute of coolant with the size of the contaminants ranging from 1 µm to 30 µm. The filter will be helpful in saving the production cost as the cost associated with the proposed design is well justified by the cost savings in production. The magnetic field produced by permanent magnets will be throughout the area underneath the reservoir. This produces magnetic field 30mm above the coolant reservoir. Very fine particles are arrested without slip. The magnetic material used will not
Fabrication and Characterization of a Conduction Cooled Thermal Neutron Filter
Energy Technology Data Exchange (ETDEWEB)
Heather Wampler; Adam Gerth; Heng Ban; Donna Post Guillen; Douglas Porter; Cynthia Papesch
2010-06-01
Installation of a conduction cooled thermal (low-energy) neutron filter in an existing domestic test reactor would provide the U.S. the capability to test new reactor fuels and materials for advanced fast (high-energy) reactor concepts. A composite consisting of Al3Hf-Al has been proposed for the neutron filter due to both the neutron filtering properties of hafnium and the conducting capabilities of aluminum. Knowledge of the thermal conductivity of the Al3Hf-Al composite is essential for the design of the filtering system. The present objectives are to identify a suitable fabrication technique and to measure the thermophysical properties of the Al3Hf intermetallic, which has not been done previous to this study. A centrifugal casting method was used to prepare samples of Al3Hf. X-ray diffraction and Rietveld analysis were conducted to determine the structural make-up of each of the samples. Thermophysical properties were measured as follows: specific heat by a differential scanning calorimeter (DSC), thermal diffusivity by a laser flash thermal diffusivity measuring system, thermal expansion by a dilatometer, and thermal conductivity was calculated based on the previous measurements. All measurements were acquired over a temperature range of 90°C - 375°C with some measurements outside these bounds. The average thermal conductivity of the intermetallic Al3Hf (~7 at.% Hf) was found to be ~ 41 W/m-K for the given temperature range. This information fills a knowledge gap in the thermophysical properties of the intermetallic Al3Hf with the specified percentage of hafnium. A model designed to predict composite properties was used to calculate a thermal conductivity of ~177 W/m-K for an Al3Hf-Al composite with 23 vol% Al3Hf. This calculation was based upon the average thermal conductivity of Al3Hf over the specified temperature range.
Numerical and experimental study of pulse-jet cleaning in fabric filters
DEFF Research Database (Denmark)
O. Andersen, B.; Nielsen, N. F.; Walther, J. H.
2016-01-01
for many years by experimental investigation and to a limited extent by Computational Fluid Dynamics (CFD). The majority of the studies have focused on high-pressure cleaning systems, and the CFD models presented are so far two-dimensional (2D). In the work presented here, pulse-jet cleaning of low......Pulse-jet cleaning and understanding of the complex physics are essential when designing fabric filters used for air pollution control. Today, low-pressure cleaning is of particular interest due to demand for reduced compressed air consumption. Pulse-jet cleaned fabric filters have been studied......-pressure fabric filters (2 bar) is studied using a full three-dimensional (3D) CFD model. Experimental results obtained in a pilot-scale test filter with 28 bags, in length of 10 m and in general full-scale dimensions of the cleaning system are used to verify the reliability of the present CFD model...
Economics of fabric filters and electrostatic precipitators - 1984. Final report
Energy Technology Data Exchange (ETDEWEB)
Scheck, R.W.; Mora, R.R.; Belba, V.H.; Horney, F.A.
1985-06-01
This report compares the operating and maintenance costs, and equipment capital costs of fabric filter (F) and electrostatic precipitator (ESP) systems for typical 500 MW units meeting a range of particulate emission limitations and firing fuel from fuel (5) major coal and lignite fields. To meet the current New Source Performance Standard 0.03 lbs/10/sup 6/ Btu, ESPs and FFs were found to be economically equivalent for the more precipitable ash from high- to medium-sulfur, eastern coals and North Dakota lignites. The fabric filter is the economic choice for the low-sulfur, western coals investigated in this report. Irrespective of coal and ash properties, a conventional reverse-gas FF with an air-to-cloth ratio of 2.0 ft/min was found to be the economic choice over an ESP with a specific collecting area greater than 500 ft/sup 2//1000 ACFM. This report also examines the cost benefits of applying advanced technology and optimized designs to FFs and ESPs. For example, the levelized costs of a conventional reverse-gas FF can be reduced by increasing the air-to-cloth ratio above the conventional design valve of 2.0 ft/min, with a minimum cost calculated near 2.7 ft/min. Other technologies investigated are shake/deflate and sonic cleaning of FFs, and gas conditioned ESPs. The sensitivity of a particulate collection system's cost estimate to such factors as air-to-cloth ratio, bag life, and power consumption is also demonstrated. 29 refs., 46 figs., 53 tabs.
Directory of Open Access Journals (Sweden)
Arathy Rajagopal
2014-01-01
Full Text Available A major security challenge on the Internet is the existence of the large number of compromised machines. Such machines have been increasingly used to launch various security attacks including spamming and spreading malware, DDoS, and identity theft. These compromised machines are called “Zombies”. In general E-mail applications and providers uses spam filters to filter the spam messages. Spam filtering is a technique for discriminating the genuine message from the spam messages. The attackers send the spam messages to the targeted machine by exalting the filters, which causes the increase in false positives and false negatives. We develop an effective spam zombie detection system named SPOT by monitoring outgoing messages of a network. SPOT focuses on the number of outgoing messages that are originated or forwarded by each computer on a network to identify the presence of Zombies. SPOT is designed based on a powerful statistical tool called Sequential Probability Ratio Test, which has bounded false positive and false negative error rates.
Directory of Open Access Journals (Sweden)
Arathy Rajagopal
2015-10-01
Full Text Available A major security challenge on the Internet is the existence of the large number of compromised machines. Such machines have been increasingly used to launch various security attacks including spamming and spreading malware, DDoS, and identity theft. These compromised machines are called "Zombies". In general E-mail applications and providers uses spam filters to filter the spam messages. Spam filtering is a technique for discriminating the genuine message from the spam messages. The attackers send the spam messages to the targeted machine by exalting the filters, which causes the increase in false positives and false negatives. We develop an effective spam zombie detection system named SPOT by monitoring outgoing messages of a network. SPOT focuses on the number of outgoing messages that are originated or forwarded by each computer on a network to identify the presence of Zombies. SPOT is designed based on a powerful statistical tool called Sequential Probability Ratio Test, which has bounded false positive and false negative error rates.
Performance evaluation of PAN nanofiber air filter fabricated by electrospinning
Energy Technology Data Exchange (ETDEWEB)
Kim, Kyung Cheol; Kim, Tae Eun; Lee, Jung Koo; Ahn, Ji Woong; Park, Sung Ho; Kim, Hyung Man [Dept. of Electronic, Telecommunications, Mechanical and Automotive Engineering, Inje University, Kimhae (Korea, Republic of)
2015-11-15
Nanomaterials possess unique mechanical, physical, and chemical properties. They are small, and have an ultrahigh surface area, making them suitable for air filter applications. Electrospinning has been recognized as an efficient technique for fabricating polymer nanofibers. In order to determine the optimum manufacturing conditions, the effects of several electrospinning process parameters on the diameter, orientation, and distribution of polyacrylonitrile (PAN) nanofiber are analyzed. To improve interlaminar fracture toughness and suppress delamination in the form of laminated non-woven fibers by using a heat roller, the performances of filter efficiency and pressure drop achieved with PAN nanofiber air filter are evaluated experimentally.
Mao, Ning; Yao, Yuping; Hata, Mitsuhiko; Wada, Masashi; Kanaoka, Chikao
2008-01-01
VDI type-1 rig and JIS rig are the two major testing rigs for cleanable fabric filters. We measured the filter cleaning performance using these rigs and the results were compared in order to characterize the two testing methods. The filter performance tests showed that the filter cleaning efficiency measured with VDI type-1 rig is higher than that with JIS rig. During pulse jet cleaning, JIS rig gave a higher peak pressure and a shorter time period of pulse jet compared to VDI type-1 rig. A n...
Design and fabrication of multiple airgap-based visible filters
Ghaderi, M.; Wolffenbuttel, R. F.
2014-05-01
The efficiency of a Bragg reflector design for implementation in optical resonators is highly dependent on the ratio between the high-index material and the low-index material used for the quarter-wavelength (QWOT) layers. A higher contrast implies that fewer layers are required to achieve a specified spectral selectivity over a wider spectral band. In turn, the reduced total thickness of the filter stack reduces the effect of optical absorption in the layers. The research presented here focuses on implementation of filters on top of silicon detectors that are already fabricated in a CMOS process. This implies that the constraints of process compatibility, such as the materials to be used, process temperature and cleanroom reentrance related to contamination, need to be considered. Silicon-dioxide is often used in CMOS-compatible designs, which has an index of refraction n~1.5, thus limiting nHi/nLo to about 2. This value can be improved by 50% when using air-films as the low-n material. Surface micromachining is used for the fabrication of such mirrors. Multiple layers of Si and SiO2 were alternatingly deposited, and subsequently the Si layers are selectively removed in a sacrificial etch. The width of the λ/4 air-gaps is about 100 nm, which is narrower as compared to the typical layer thickness that is used in surface micromachining for conventional MEMS applications. Moreover, a demanding optical design requires more layers than typically used in a conventional MEMS device. Since the number of stacked layers is significantly higher as compared to the conventional MEMS, fabricating such filters is a challenge. However, unlike a conventional MEMS, electrical contacting to the structural layers is not required in optical filter application, which, eases the fabrication of such filters. This paper presents the design of several 4-layer structures for use in the visible spectral range, along with the fabrication sequence and preliminary measurement results.
Fabrication of optical filters based on polymer asymmetric Bragg couplers.
Chuang, Wei-Ching; Lee, An-Chen; Chao, Ching-Kong; Ho, Chi-Ting
2009-09-28
In this work, we successfully developed a process to fabricate dual-channel polymeric waveguide filters based on an asymmetric Bragg coupler (ABC) using holographic interference techniques, soft lithography, and micro molding. At the cross- and self-reflection Bragg wavelengths, the transmission dips of approximately -16.4 and -11.5 dB relative to the 3 dB background insertion loss and the 3 dB transmission bandwidths of approximately 0.6 and 0.5 nm were obtained from an ABC-based filter. The transmission spectrum overlaps when the effective index difference between two single waveguides is less than 0.002.
Comparison between disc and non-woven synthetic fabric filter media to prevent emitter clogging
Ribeiro, TAP; Paterniani, JES; Airoldi, RPS; Silva, MJM
2008-01-01
The aim of this research was to compare the evolution of head loss in disc (130 mu m) and non-woven synthetic fabric filter media used to filter the water in drip irrigation systems. Two forms of treatment of the irrigation water were carried out: one with a chemical product (chlorine) and the other with none. The research used two different filter media: two for each treatment together with a fertigation technique with organic products in both types of treatment. The chemical treatment of th...
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)
fabrication and performance study of uniform thin film integrated filters
African Journals Online (AJOL)
Dr Obe
been analysed using the concept of matrix parameter functions. The above filter ... concept of distributed parameter. Networks. The thin film .... circuit design concept involving discrete elements ... and Micro- system Electronics,. Proc. National ...
Fabrication of a Cryogenic Bias Filter for Ultrasensitive Focal Plane
Chervenak, James; Wollack, Edward
2012-01-01
A fabrication process has been developed for cryogenic in-line filtering for the bias and readout of ultrasensitive cryogenic bolometers for millimeter and submillimeter wavelengths. The design is a microstripline filter that cuts out, or strongly attenuates, frequencies (10 50 GHz) that can be carried by wiring staged at cryogenic temperatures. The filter must have 100-percent transmission at DC and low frequencies where the bias and readout lines will carry signal. The fabrication requires the encapsulation of superconducting wiring in a dielectric-metal envelope with precise electrical characteristics. Sufficiently thick insulation layers with high-conductivity metal layers fully surrounding a patterned superconducting wire in arrayable formats have been demonstrated. A degenerately doped silicon wafer has been chosen to provide a metallic ground plane. A metallic seed layer is patterned to enable attachment to the ground plane. Thick silicon dioxide films are deposited at low temperatures to provide tunable dielectric isolation without degrading the metallic seed layer. Superconducting wiring is deposited and patterned using microstripline filtering techniques to cut out the relevant frequencies. A low Tc superconductor is used so that it will attenuate power strongly above the gap frequency. Thick dielectric is deposited on top of the circuit, and then vias are patterned through both dielectric layers. A thick conductive film is deposited conformally over the entire circuit, except for the contact pads for the signal and bias attachments to complete the encapsulating ground plane. Filters are high-aspect- ratio rectangles, allowing close packing in one direction, while enabling the chip to feed through the wall of a copper enclosure. The chip is secured in the copper wall using a soft metal seal to make good thermal and electrical contact to the outer shield.
Accurate frequency alignment in fabrication of high-order microring-resonator filters.
Sun, Jie; Holzwarth, Charles W; Dahlem, Marcus; Hastings, Jeffrey T; Smith, Henry I
2008-09-29
Frequency mismatch in high-order microring-resonator filters is investigated. We demonstrate that this frequency mismatch is caused mainly by the intrafield distortion of scanning-electron-beam-lithography (SEBL) used in fabrication. The intrafield distortion of an SEBL system is measured, and a simple method is also proposed to correct this distortion. By applying this correction method, the average frequency mismatch in second-order microring-resonator filters was reduced from -8.6 GHz to 0.28 GHz.
Influence of selected fixed parameters on pulse-jet fabric filter operation
Hindy, K. T.
The effect of (a) fixing the time interval between cleaning pulses or (b) fixing the maximum pressure drop at which cleaning is started, on the performance of the fabric filter was investigated. A maximum pressure drop value of 2500 Pa: (a) minimized the effect of the filter medium resistance; (b) reduced the energy consumption by the filter; (c) minimized the dust emission from the fabric filter to the surrounding atmosphere.
Design and fabrication of long wave infrared spectral filters
Carey, Victoria A.; McElhiney, Morgan E.; Gupta, Neelam; Jensen, Janet; Prather, Dennis W.; Mirotznik, Mark S.
2016-02-01
Multispectral and hyperspectral imaging in the long wave infrared (LWIR) spectral region has numerous applications in agriculture, astronomy20-22, medicine, and the sensing of dangerous chemical/biological agents23-25. One of the challenges of developing a spectral imaging system in the LWIR is the availability of spectral filters. We will report on three different design methods for realizing spectral filters in the LWIR. The first is an all-dielectric reflection filter based on the guidedmode resonance response. The second is a spatially-varying plasmonic structure that can be used to synthesize complicated spectral reflectance. The third is a Fabry-Perot design for tunable transmission. Numerical and experimental results will be presented.
Design and fabrication of microlens and spatial filter array by self-alignment
Yang, Ren; Chan, Kin Foong; Feng, Zhiqiang; Mei, Wenhui
2003-01-01
For typically small volume production of MEMS, MOEMS, fine feature PCB, high density chip packaging and display panels, especially for lab tests, low cost and the capability to change the original design easily and quickly are very important for customers and researchers. BALL Semiconductor Inc.'s Maskless Lithography Systems (MLS) feature the Digital Mirror Device (DMD) as the pattern generator to replace photo-masks. This can remove masks from UV lithography, and dramatically reduce the running cost and save time for lab tests and small volume production. At Ball Semiconductor Inc, 1.5μm line/space, 10μm line/space, and 20μm line/space Maskless Lithography Systems were developed. In our MLS, an 848×600 microlens and spatial filter array (MLSFA) was used to focus the light and to filter the noise. In order to produce smaller line-space than 16μm the MLSFA was used to get smaller UV light pad (compared with the SVGA DMD"s micro-mirror: 17μm×17μm) and to filter the noise produced from the DMD, optical lens system, and micro lens array. This MLSFA is one of the key devices for our Maskless Lithography System, and determines the resolution and quality of maskless lithography. A novel design and fabrication process of a single-package MLSFA for our Maskless Lithography System will be introduced. To avoid problems produced by misalignment between a two-piece spatial filter and microlens array, MEMS processing is used to integrate the microlens array with the spatial filter array. In this paper, the self-alignment method used to fabricate exactly matched MLSFA will be presented.
Reshaping technique for MOEM system fabrication
Okyar, Murat M.; Sun, Xiqing; Carr, William N.
1998-09-01
Today, the fabrication of microactuators and micromechanical parts is merely based on IC fabrication technologies. However, the 2D world of microelectronics sets a limit to the 3D micromechanical world. With a new micromachining technology, reshaping, which combines advantages of 2D IC fabrication with the third dimension of the mechanical world, a surface micromachined polycrystalline structure can be deformed to any desired 3D shape. In this work, this technique is employed for the first time to realize 3D actuators, and micro-opto-electro-mechanical systems. In this work, the design, fabrication and characterization of a micromirror are discussed. The structure is reshaped in such a way that the mirror platform, which is placed between two bimorph actuators, is tilted at a desired angle. The experimental results of electro-thermally actuated structure are in good agreement with the numerical results carried out by using IntelliCAD, an FEA tool to design and simulate MEMS. The reshaped micromirror demonstrates how reshaping technology eliminates complicated, silicon area consuming actuators. The fabrication steps of the micromirror are much simpler than those of previously reported device. A barcode scanner system employing reshaped micromirrors and optical filters is proposed as one example of many possible reshaped 3D MOEM Systems.
Tunable-Bandwidth Filter System
Aye, Tin; Yu, Kevin; Dimov, Fedor; Savant, Gajendra
2006-01-01
A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote-sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS was shown to be capable of spectral sampling of images in the visible range over a 200-nm spectral range with a spectral resolution of .30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of the lenses are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses
Non toxic additives for improved fabric filter performance
Energy Technology Data Exchange (ETDEWEB)
Bustard, C.J.; Baldrey, K.E.; Ebner, T.G. [ADA Technologies, Inc., Englewood, CO (United States)] [and others
1995-11-01
The overall objective of this three-phase Small Business innovative Research (SBIR) program funded by the Department of Energy pittsburgh Energy Technology Center (PETC) is to commercialize a technology based upon the use of non-toxic, novel flue gas conditioning agents to improve particulate air toxic control and overall fabric filter performance. The ultimate objective of the Phase II program currently in progress is to demonstrate that the candidate additives are successful at full-scale on flue gas from a coal-fired utility boiler. This paper covers bench-scale field tests conducted during the period February through May, 1995. The bench-scale additives testing was conducted on a flue gas slipstream taken upstream of the existing particulate control device at a utility power plant firing a Texas lignite coal. These tests were preceded by extensive testing with additives in the laboratory using a simulated flue gas stream and re-dispersed flyash from the same power plant. The bench-scale field testing was undertaken to demonstrate the performance with actual flue gas of the bet candidate additives previously identified in the laboratory. Results from the bench-scale tests will be used to establish operating parameters for a larger-scale demonstration on either a single baghouse compartment or a full baghouse at the same site.
Evaluating document filtering systems over time
Kenter, T.; Balog, K.; de Rijke, M.
2015-01-01
Document filtering is a popular task in information retrieval. A stream of documents arriving over time is filtered for documents relevant to a set of topics. The distinguishing feature of document filtering is the temporal aspect introduced by the stream of documents. Document filtering systems, up
Polymeric THz 2D Photonic Crystal Filters Fabricated by Fiber Drawing
DEFF Research Database (Denmark)
Stecher, Matthias; Jansen, Christian; Ahmadi-Boroujeni, Mehdi
2012-01-01
In this paper, we report on a new form of polymeric 2D photonic crystal filters for THz frequencies fabricated using a standard fiber drawing technique. The band stop filters were modeled and designed using the generalized multipole technique. The frequency and angle-dependent transmission...
Filter aids influence on pressure drop across a filtration system
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.
Filtering and control of wireless networked systems
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.
Cai, Yuan; Zhou, Sheng; Ma, Xiaofeng; Liu, Dingquan
2016-11-20
Dual-band-pass filters are key optical components in dual-spectral detection applications; it is imperative to fabricate them in a relatively simple way for practical use. In this paper, a dual-band-pass filter working in short-wavelength infrared is developed by the combination of two Fabry-Perot (F-P) filters, each having a transparent band. These two filters are designed separately, and deposited at different sides of a substrate. The total layers' number of the dual-band-pass filter is limited to 34; these layers are monitored by the method of direct transmittance level cut monitoring with a single monitor wavelength. The percent of optical extrema monitoring strategy is adopted in the deposition. The spectra of the F-P filters and the dual-band-pass filter are tested. The shorter pass-band's average transmittance is above 84%, the longer one is above 88%, and four of the pass-bands' edge steepness values are 1.4%,2.8%,1.9%, and 1.7%.
Wave disturbance filtering in dynamic positioning systems
Directory of Open Access Journals (Sweden)
Tor S. Schei
1996-04-01
Full Text Available Three different approaches to wave disturbance filtering in dynamic positioning systems are studied in this paper. It is shown that a conventional design based on notch filters leads to approximately the same achievable performance of the total control system as can be achieved with an observer based design. It is also shown that a proposed passivity based design leads to a conventional filter with PD-controller. However, there is a relation between the parameters in the filter and the PD-controller, which ensures the passivity properties of the control system.
On the Forming Mechanism of the Cleaning Airflow of Pulse-jet Fabric Filters.
Jiying, Cai; Wenge, Hao; Cong, Zhang; Jiaqi, Yu; Ting, Wang
2017-04-05
-type rectifier tube is installed at the bag opening, the jet flow is converted to funnel flow whose cross-section velocity distribution is more uniform at the throat of rectifier tube due to the guided effects of upper tapered pipe. Then it is transited to stressful flow below bag opening via rectified effects of the lower dilated pipe. The results show that the gap between the static pressure of gas in the bag and the expected value is significantly reduced. The theoretical value of nozzle diameter is enlarged to compensate for two aspects of adverse effects of cleaning airflow and energy. This is because the flow is not a purely free-form jet from the nozzle to the entrance of the rectifier tube and because the gas suffers from local resistance while flowing through the rectifier tube. The numerical simulation and experiment show that the peak pressure of cleaning airflow in the filter bag is able to reach the expected value. The results confirm that the mechanism of pulse-jet cleaning airflow and the calculation method of the pulse-jet cleaning system structure and operating parameters offered in this study is correct. The study results provide scientific basis for designing the system of pulse-jet fabric filters.
Model calibration for pressure drop in a pulse-jet cleaned fabric filter
Koehler, John L.; David, Leith
A model based on Darcy's law allows prediction of pressure drop in a pulse-jet cleaned fabric filter. The model considers the effects of filtration velocity, dust areal density added during one filtration cycle, and pulse pressure. Data used to calibrate the model were collected in experiments with three fabric surface treatments and three dusts conducted at three filtration velocities, for a total of 27 different experimental conditions. The fabric used was polyester felt with untreated, singed, or PTFE-laminated surface. The dusts used were granite, limestone and fly ash. Filtration velocities were 50,75 and 100 mm s -1. Dust areal density added during one filtration cycle was constant, as was pulse pressure. Under these conditions, fabric surface treatment alone largely determined the values for two of the three constants in the model; the third constant depends on pressure drop characteristics of the venturi at the top of each filter bag.
Active imaging system with Faraday filter
Snyder, James J.
1993-01-01
An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.
Antithrombotic Protein Filter Composed of Hybrid Tissue-Fabric Material has a Long Lifetime.
Inoue, Yusuke; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Kaneko, Akiko; Woo, Taeseong; Kobayashi, Shingo; Shibuya, Tomokazu; Tanaka, Masaru; Kosukegawa, Hiroyuki; Saito, Itsuro; Isoyama, Takashi; Abe, Yusuke; Yambe, Tomoyuki; Someya, Takao; Sekino, Masaki
2017-05-01
There are recent reports of hybrid tissue-fabric materials with good performance-high biocompatibility and high mechanical strength. In this study, we demonstrate the capability of a hybrid material as a long-term filter for blood proteins. Polyester fabrics were implanted into rats to fabricate hybrid tissue-fabric material sheets. The hybrid materials comprised biological tissue grown on the fabric. The materials were extracted from the rat's body, approximately 100 days post-implantation. The tissues were decellularized to prevent immunological rejection. An antithrombogenicity test was performed by dropping blood onto the hybrid material surface. The hybrid material showed lesser blood coagulation than polysulfone and cellulose. Blood plasma was filtered using the hybrid material to evaluate the protein removal percentage and the lifetime of the hybrid material in vitro. The hybrid material showed a comparable performance to conventional filters for protein removal. Moreover, the hybrid material could work as a protein filter for 1 month, which is six times the lifetime of polysulfone.
Design, optimization and fabrication of an optical mode filter for integrated optics.
Magnin, Vincent; Zegaoui, Malek; Harari, Joseph; François, Marc; Decoster, Didier
2009-04-27
We present the design, optimization, fabrication and characterization of an optical mode filter, which attenuates the snaking behavior of light caused by a lateral misalignment of the input optical fiber relative to an optical circuit. The mode filter is realized as a bottleneck section inserted in an optical waveguide in front of a branching element. It is designed with Bézier curves. Its effect, which depends on the optical state of polarization, is experimentally demonstrated by investigating the equilibrium of an optical splitter, which is greatly improved however only in TM mode. The measured optical losses induced by the filter are 0.28 dB.
Energy Technology Data Exchange (ETDEWEB)
Commandré, Mireille, E-mail: mireille.commandre@fresnel.fr [Centrale Marseille, Aix Marseille Université, CNRS, Institut Fresnel, UMR 7249, 13013 Marseille (France); Vial, Benjamin [Centrale Marseille, Aix Marseille Université, CNRS, Institut Fresnel, UMR 7249, 13013 Marseille (France); Silios Technologies, ZI Peynier-Rousset, rue Gaston Imbert Prolongée, 13790 Peynier (France); Tisserand, Stéphane; Roux, Laurent [Silios Technologies, ZI Peynier-Rousset, rue Gaston Imbert Prolongée, 13790 Peynier (France); Dallaporta, Hervé; Bedu, Frédéric [Aix Marseille Université, CNRS, CiNaM, UMR 7325, Campus de Luminy, Case 913, 13288 Marseille Cedex 9 (France); Demésy, Guillaume; Nicolet, André; Zolla, Frédéric [Centrale Marseille, Aix Marseille Université, CNRS, Institut Fresnel, UMR 7249, 13013 Marseille (France)
2015-10-01
We present the design of infrared filters for multispectral imaging applications, based on square annular aperture arrays in a thin gold film. These structures function as band pass filters with large bandwidth and high transmission at resonance. A modal analysis based on the Finite Element Method (FEM) is performed to obtain quickly the features of this resonance. The center wavelength can be tuned in the 7–12 μm range while keeping constant the quality factor and maximum transmission by scaling all transverse dimensions of the apertures, which allows to obtain filters with different centering on the same substrate in a single fabrication step. Large area samples have been fabricated on a silicon wafer by electronic lithography. Spectrophotometric measurements are in rather good agreement with numerical predictions. In addition, angle resolved measurements show that the filters are quite tolerant to the incidence angle up to 30° for both polarizations which is consistent with our FEM simulations. Finally, a complete sensitivity analysis allows us to evaluate acceptable opto-geometric tolerances of fabrication and thus to improve reproducibility on large areas. The impact of fabrication defaults (rounded corners, aperture anisotropy, aperture edge roughness, sloping aperture edges) on the filtering performances is analyzed. The simulations of realistic structures allow to explain and reduce the differences between measured and simulated spectra. - Highlights: • A theoretical and experimental study of resonant transmission of aperture arrays • Transmission filters in the infrared range are developed for multispectral imaging. • Impact of fabrication defaults, rounded corners, and aperture anisotropy is analyzed. • The simulations of realistic structures increase agreement measurement/simulation.
Fabrication of frequency selective surface for band stop IR-filter
Energy Technology Data Exchange (ETDEWEB)
Mishra, Akshita, E-mail: akshitamishra27@gmail.com [Department of Electrical Engineering, Indian Institute of Technology Delhi, New Delhi-110016 (India); Sudheer,; Tiwari, P.; Mondal, P.; Rai, V. N.; Srivastava, A. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Bhatt, H. [High Pressure and Synchrotrons Radiation Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)
2016-05-23
Fabrication and characterization of frequency selective surfaces (FSS) on silicon dioxide/ silicon is reported. Electron beam lithography based techniques are used for the fabrication of periodic slot structure in tungsten layer on silicon dioxide/silicon. The fabrication process consists of growth of SiO{sub 2} on silicon, tungsten deposition, electron beam lithography, and wet etching of tungsten. The optical characterization of the structural pattern was carried out using fourier transform infrared spectroscopy (FTIR). The reflectance spectra clearly show a resonance peak at 9.09 µm in the mid infrared region. This indicates that the patterned surface acts as band stop filter in the mid-infrared region.
Qian, Fuping; Wang, Haigang
2010-04-15
The gas-solid two-phase flows in the plain wave fabric filter were simulated by computational fluid dynamics (CFD) technology, and the warps and wefts of the fabric filter were made of filaments with different dimensions. The numerical solutions were carried out using commercial computational fluid dynamics (CFD) code Fluent 6.1. The filtration performances of the plain wave fabric filter with different geometry parameters and operating condition, including the horizontal distance, the vertical distance and the face velocity were calculated. The effects of geometry parameters and operating condition on filtration efficiency and pressure drop were studied using response surface methodology (RSM) by means of the statistical software (Minitab V14), and two second-order polynomial models were obtained with regard to the effect of the three factors as stated above. Moreover, the models were modified by dismissing the insignificant terms. The results show that the horizontal distance, vertical distance and the face velocity all play an important role in influencing the filtration efficiency and pressure drop of the plane wave fabric filters. The horizontal distance of 3.8 times the fiber diameter, the vertical distance of 4.0 times the fiber diameter and Reynolds number of 0.98 are found to be the optimal conditions to achieve the highest filtration efficiency at the same face velocity, while maintaining an acceptable pressure drop.
RECOMMENDATION SYSTEM USING BLOOM FILTER IN MAPREDUCE
Directory of Open Access Journals (Sweden)
Reena Pagare
2013-11-01
Full Text Available Many clients like to use the Web to discover product details in the form of online reviews. The reviews are provided by other clients and specialists. Recommender systems provide an important response to the information overload problem as it presents users more practical and personalized information facilities. Collaborative filtering methods are vital component in recommender systems as they generate high-quality recommendations by influencing the likings of society of similar users. The collaborative filtering method has assumption that people having same tastes choose the same items. The conventional collaborative filtering system has drawbacks as sparse data problem & lack of scalability. A new recommender system is required to deal with the sparse data problem & produce high quality recommendations in large scale mobile environment. MapReduce is a programming model which is widely used for large-scale data analysis. The described algorithm of recommendation mechanism for mobile commerce is user based collaborative filtering using MapReduce which reduces scalability problem in conventional CF system. One of the essential operations for the data analysis is join operation. But MapReduce is not very competent to execute the join operation as it always uses all records in the datasets where only small fraction of datasets are applicable for the join operation. This problem can be reduced by applying bloomjoin algorithm. The bloom filters are constructed and used to filter out redundant intermediate records. The proposed algorithm using bloom filter will reduce the number of intermediate results and will improve the join performance.
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
Design, Fabrication and Installation of the Charcoal Filter Housing in RIPF
Energy Technology Data Exchange (ETDEWEB)
Kim, Min Jin; Lim, I. C.; Bang, H. S. (and others)
2008-05-15
In the Hot Cell Bank 3 of the Radioisotope Production Facility, production and dispense of I-131 solution and capsule that are used for the diagnosis and treatment of thyroid cancer are made. The original charcoal filter housings installed in 1994 and were utilized until the leakage of a very small amount of radio-iodine was found due to the erroneous installation of the charcoal filter in the filter housing. Thus the production of I-131 was discontinued until the repair and performance testing of the filter housing and the inspection by the regulatory body were finished. Although the production of I-131 was resumed, there was a desire for installing the brand-new charcoal filter housing which has an intrinsically safe design and no possibility of leakage. This report describes the design, fabrication and installation of brand-new charcoal filter housing. And also were described the dismantlement of the old housings, the assessment of the structural integrity of the shielding concrete wall and the installation of the shielding doors.
Fabrication of dense wavelength division multiplexing filters with large useful area
Lee, Cheng-Chung; Chen, Sheng-Hui; Hsu, Jin-Cherng; Kuo, Chien-Cheng
2006-08-01
Dense Wavelength Division Multiplexers (DWDM), a kind of narrow band-pass filter, are extremely sensitive to the optical thickness error in each composite layer. Therefore to have a large useful coating area is extreme difficult because of the uniformity problem. To enlarge the useful coating area it is necessary to improve their design and their fabrication. In this study, we discuss how the tooling factors at different positions and for different materials are related to the optical performance of the design. 100GHz DWDM filters were fabricated by E-gun evaporation with ion-assisted deposition (IAD). To improve the coating uniformity, an analysis technique called shaping tooling factor (STF) was used to analyze the deviation of the optical thickness in different materials so as to enlarge the useful coating area. Also a technique of etching the deposited layers with oxygen ions was introduced. When the above techniques were applied in the fabrication of 100 GHz DWDM filters, the uniformity was better than +/-0.002% over an area of 72 mm in diameter and better than +/-0.0006% over 20mm in diameter.
Directory of Open Access Journals (Sweden)
Nguyen Duy Vinh
2016-08-01
Full Text Available Nano materials possess unique mechanical, physical, and chemical properties. They are small, and have an ultrahigh surface area, making them suitable for air filter applications since air filtration is necessary to protect sensitive components from harmful particulates and gaseous contaminants. The electrospinning method has been recognized as an efficient technique for fabricating polymer nanofibers. In order to determine the optimum manufacturing conditions, the effects of several electrospinning process parameters on the diameter, orientation, and distribution of polyacrylonitrile (PAN nanofiber are analyzed. To improve interlaminar fracture toughness and suppress the delamination in the form of laminated non-woven fibers by using a heat roller, the performances of filter efficiency and pressure drop achieved with the PAN nanofiber air filter are evaluated experimentally.
WORKLOAD CHARACTERIZATION OF SPAM EMAIL FILTERING SYSTEMS
Directory of Open Access Journals (Sweden)
Yan Luo
2010-01-01
Full Text Available Email systems have suffered from degraded quality of service due to rampant spam, phishing and fraudulent emails. This is partly because the classification speed of email filtering systems falls far behindthe requirements of email service providers. We are motivated to address this issue from the perspective of computer architecture support. In this paper, as the first step towards novel architecture designs, we present extensive performance data collected from measurement and profiling experiments using representative email filtering systems including CRM114, DSPAM, SpamAssassin and TREC Bogofilter. We provide detailed analysis of the time consuming functions in the systems under study. We also show how the processor architecture parameters affect the performance of these email filters through simulation experiments.
Study on the fabrication of low-pass metal powder filters for use at cryogenic temperatures
Lee, Sung Hoon
2016-01-01
We fabricated compact low-pass stainless-steel powder filters for use in low-noise measurements at cryogenic temperatures and investigated their attenuation characteristics for different wire lengths, shapes, and preparation methods up to 20 GHz. We used nominally 30-micrometer-sized SUS 304L powder and mixed with Stycast 2850FT by Emerson and Cumming with catalyst 23LV. A 0.1 mm insulated copper wire was wound on preformed powder-mixture spools in the shape of a right-circular cylinder, a flattened elliptic cylinder and a toroid, and the coils were encapsulated in metal tubes or boxes filled with the powder mixture. All the fabricated powder filters showed a large attenuation at high frequencies with a cut-off frequency near 1 GHz. However, the toroidal filter showed prominent ripples corresponding to resonance modes in the 0.5-m-long coil wire. A filter with a 2:1 powder/epoxy mixture mass rate and a wire length of 1.53 m showed an attenuation of -93 dB at 4 GHz and the attenuation was linearly proportional...
Eskelinen, Petri
2015-01-01
The tightening of regulations related to particle emissions has made retrofitting the ESP into a hybrid of the ESP and a baghouse filter a possible solution to some old plants in Finland. The objective of this thesis was to assess when this is a viable option and to study the advantage and limitations of the system by comparing it to other options available to companies when they need to have more efficient filters. For this purpose, is was necessary to compile the pricing of a new ESP and...
Study on the fabrication of low-pass metal powder filters for use at cryogenic temperatures
Lee, Sung Hoon; Lee, Soon-Gul
2016-08-01
We fabricated compact low-pass stainless-steel powder filters for use in low-noise measurements at cryogenic temperatures and investigated their attenuation characteristics for different wire lengths, filter shapes, and preparation methods at frequencies up to 20 GHz. We used nominally 30- μm-sized SUS 304L powder and mixed it with Stycast 2850FT (Emerson and Cumming) with catalyst 23LV. A 0.1-mm insulated copper wire was wound on preformed powder-mixture spools in the shape of a right-circular cylinder, a flattened elliptic cylinder and a toroid, and the coils were encapsulated in metal tubes or boxes filled with the powder mixture. All the fabricated powder filters showed a large attenuation at high frequencies with a cut-off frequency near 1 GHz. However, the toroidal filter showed prominent ripples corresponding to resonance modes in the 0.5-m-long coil wire. A filter with a 2:1 powder/epoxy mixture mass ratio and a wire length of 1.53 m showed an attenuation of -93 dB at 4 GHz, and the attenuation was linearly proportional to the wire's length. As the powder-to-epoxy ratio was increased, the high-frequency attenuation increased. An equally-spaced single-layer coil structure was found to be more efficient in attenuation than a double-layer coil. The geometry of the metal filter's case affected the noise ripples, with the least noise being found for a circular tube.
Micro-Electro-Mechanical Systems (MEMS) Fabrication Course Projects Review for FY15
2015-09-01
TECHNICAL DOCUMENT 3298 September 2015 Micro -Electro-Mechanical Systems (MEMS) Fabrication Course Projects Review for FY15 Paul D. Swanson...Wayne McGinnnis: 71730 Precise Front to Back Side Alignment Using Through Wafer Etching o Jonathon Oiler: 81320 Micro -Fluidic Flow Channel...Filtering Due to high particle (organic/non-organic) concentration in sea water – pre-filtering is required Secondary micro -fluidic filtering
Makitsubo, Hironobu; Kataza, Hirokazu; Mita, Makoto; Suzuki, Toyoaki; Yamamoto, Keita
2016-01-01
We propose an all-silicon multi-layer interference filter composed solely of silicon with sub-wavelength structure (SWS) in order to realize high performance optical filters operating in the THz frequency region with robustness against cryogenic thermal cycling and mechanical damage. We demonstrate fabrication of a three-layer prototype using well-established common micro-electro-mechanical systems (MEMS) technologies as a first step toward developing practical filters. The measured transmittance of the three-layer filter agrees well with the theoretical transmittances calculated by a simple thin-film calculation with effective refractive indices as well as a rigorous coupled-wave analysis simulation. We experimentally show that SWS layers can work as homogeneous thin-film interference layers with effective refractive indices even if there are multiple SWS layers in a filter.
Mercury oxidation in flue gas using gold and palladium catalysts on fabric filters.
Hrdlicka, Jason A; Seames, Wayne S; Mann, Michael D; Muggli, Darrin S; Horabik, Carol A
2008-09-01
The feasibility of oxidizing elemental mercury in coal combustion flue gas using catalytic material impregnated onto fabric filters was explored. TiO2, Au/TiO2, and Pd/Al2O3 were studied based on promising results in previous research. Several fabric coating methods were investigated to determine the best way to load a filter. A spray coat method was found to have the highest initial loading and had the lowest losses after simulated pulse-jet cleaning. The oxidation performance of the catalyst-coated filters was tested using a simulated flue gas in a bench-scale reactor under conditions similar to those found in a baghouse. Au/TiO2 and Pd/Al2O3 were effective, yielding mercury oxidation ranges of 40-60% and 50-80%, respectively. A 19 kW research combustor equipped with a baghouse was used to fire a range of coals and further test the performance of Pd/Al2O3. Results obtained warrant further development of this technique as a means of mercury pollution control.
Mercury oxidation in flue gas using gold and palladium catalysts on fabric filters
Energy Technology Data Exchange (ETDEWEB)
Jason A. Hrdlicka; Wayne S. Seames; Michael D. Mann; Darrin S. Muggli; Carol A. Horabik [University of North Dakota, Grand Forks, ND (United States). Department of Chemical Engineering
2008-09-01
The feasibility of oxidizing elemental mercury in coal combustion flue gas using catalytic material impregnated onto fabric filters was explored. TiO{sub 2}, Au/TiO{sub 2}, and Pd/Al{sub 2}O{sub 3} were studied based on promising results in previous research. Several fabric coating methods were investigated to determine the best way to load a filter. A spray coat method was found to have the highest initial loading and had the lowest losses after simulated pulse-jet cleaning. The oxidation performance of the catalyst-coated filters was tested using a simulated flue gas in a bench-scale reactor under conditions similar to those found in a baghouse. Au/TiO{sub 2} and Pd/Al{sub 2}O{sub 3} were effective, yielding mercury oxidation ranges of 40-60% and 50-80%, respectively. A 19 kW research combustor equipped with a baghouse was used to fire a range of coals and further test the performance of Pd/Al{sub 2}O{sub 3}. Results obtained warrant further development of this technique as a means of mercury pollution control. 19 refs., 2 figs., 5 tabs.
Takahashi, Shigetoshi; Hwang, In-Hee; Matsuto, Toshihiko
2016-06-01
Fabric filters are widely used to remove dust from flue gas generated by waste incineration. However, a pressure drop occurs at the filters, caused by growth of a dust layer on the filter fabric despite regular cleaning by pulsed-jet air. The pressure drop at the fabric filters leads to energy consumption at induced draft fan to keep the incinerator on negative pressure, so that its proper control is important to operate incineration facility efficiently. The pressure drop at fabric filters decreased whenever phosphoric acid wastewater (PAW) was sprayed into an incinerator for treating industrial waste. Operational data obtained from the incineration facility were analyzed to determine the short- and long-term effects of PAW spraying on the pressure drop. For the short-term effect, it was confirmed that the pressure drop at the fabric filters always decreased to 0.3-1.2kPa within about 5h after spraying PAW. This effect was expected to be obtained by about one third of present PAW spraying amount. However, from the long-term perspective, the pressure drop showed an increase in the periods of PAW spraying compared with periods for which PAW spraying was not performed. The pressure drop increase was particularly noticeable after the initial PAW spraying, regardless of the age and type of fabric filters used. These results suggest that present PAW spraying causes a temporary pressure drop reduction, leading to short-term energy consumption savings; however, it also causes an increase of the pressure drop over the long-term, degrading the overall operating conditions. Thus, appropriate PAW spraying conditions are needed to make effective use of PAW to reduce the pressure drop at fabric filters from a short- and long-term point of view.
Stokes identification in an atomic ensemble using a filtering system
Institute of Scientific and Technical Information of China (English)
Luo Xiao-Ming; Ning Bo; Chen Li-Qing; Zhou Yue; Zhong Zhi-Ping; Jiang Shuo
2009-01-01
Polarization filtering and atomic cell filtering are applied in the identification of Stokes signals in an atomic ensemble, and reduce the noise to a level of 10~(-5) and 10~(-4) respectively. Good Stokes signals are then obtained. In this article the two filtering systems and the final Stokes output are presented, and the optimization of the polarization filtering system is highlighted.
Further developed filter systems for keeping the air clean
Energy Technology Data Exchange (ETDEWEB)
Hochstrat, W.B.
1978-12-01
The pulse-jet filter system is presented in this contribution. The development of improved fibers to produce high-quality needle felting was the basis for surface filters as well as tube filters. The system tube filter with pressurized-air cleaning is described in greater detail. Its advantage besides good degrees of separation is especially the little maintenance required.
Robust filtering for uncertain systems a parameter-dependent approach
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; ·...
Scala, F
2001-11-01
Following a companion paper focused on the in-duct mercury capture in incinerator flue gas by powdered activated carbon injection, this paper is concerned with the additional mercury capture on the fabric filter cake, relevant to baghouse equipped facilities. A detailed model is presented for this process, based on material balances on mercury in both gaseous and adsorbed phases along the growing filter cake and inside the activated carbon particles,taking into account mass transfer resistances and adsorption kinetics. Several sorbents of practical interest have been considered, whose parameters have been evaluated from available literature data. The values and range of the operating variables have been chosen in order to simulate typical incinerators operating conditions. Results of simulations indicate that, contrary to the in-duct removal process, high mercury removal efficiencies can be obtained with moderate sorbent consumption, as a consequence of the effective gas/sorbent contacting on the filter. Satisfactory utilization of the sorbents is predicted, especially at long filtration times. The sorbent feed rate can be minimized by using a reactive sorbent and by lowering the filter temperature as much as possible. Minor benefits can be obtained also by decreasing the sorbent particle size and by increasing the cleaning cycle time of the baghouse compartments. Reverse-flow baghouses were more efficient than pulse-jet baghouses, while smoother operation can be obtained by increasing the number of baghouse compartments. Model results are compared with available relevant full scale data.
Fabrication of a Terahertz Imaging System
2007-11-02
portable Stirling Cycle coolers . This SiC-based THz source, or other THz sources still under development, can replace the CO2 laser used in the...1 DARPA PROJECT FINAL REPORT PROJECT TITLE: Fabrication of a Terahertz Imaging System PRINCIPAL INVESTIGATORS: Profs. James Kolodzey and...29 2004 OBJECTIVE: Demonstration of a THz imaging system , constructed using commercial components and devices fabricated at the University of
Photometric transformation from RGB Bayer filter system to Johnson-Cousins BVR filter system
Park, Woojin; Pak, Soojong; Shim, Hyunjin; Le, Huynh Anh N.; Im, Myungshin; Chang, Seunghyuk; Yu, Joonkyu
2016-01-01
The RGB Bayer filter system consists of a mosaic of R, G , and B filters on the grid of the photo sensors which typical commercial DSLR (Digital Single Lens Reflex) cameras and CCD cameras are equipped with. Lot of unique astronomical data obtained using an RGB Bayer filter system are available, including transient objects, e.g. supernovae, variable stars, and solar system bodies. The utilization of such data in scientific research requires that reliable photometric transformation methods are available between the systems. In this work, we develop a series of equations to convert the observed magnitudes in the RGB Bayer filter system (RB,GB , and BB) into the Johnson-Cousins BVR filter system (BJ,VJ , and RC). The new transformation equations derive the calculated magnitudes in the Johnson-Cousins filters (BJcal,VJcal , and RCcal) as functions of RGB magnitudes and colors. The mean differences between the transformed magnitudes and original magnitudes, i.e. the residuals, are Δ (BJ -BJcal) = 0.064 mag, Δ (VJ -VJcal) = 0.041 mag, and Δ (RC -RCcal) = 0.039 mag. The calculated Johnson-Cousins magnitudes from the transformation equations show a good linear correlation with the observed Johnson-Cousins magnitudes.
An Adaptive Nonlinear Filter for System Identification
Directory of Open Access Journals (Sweden)
Tokunbo Ogunfunmi
2009-01-01
Full Text Available The primary difficulty in the identification of Hammerstein nonlinear systems (a static memoryless nonlinear system in series with a dynamic linear system is that the output of the nonlinear system (input to the linear system is unknown. By employing the theory of affine projection, we propose a gradient-based adaptive Hammerstein algorithm with variable step-size which estimates the Hammerstein nonlinear system parameters. The adaptive Hammerstein nonlinear system parameter estimation algorithm proposed is accomplished without linearizing the systems nonlinearity. To reduce the effects of eigenvalue spread as a result of the Hammerstein system nonlinearity, a new criterion that provides a measure of how close the Hammerstein filter is to optimum performance was used to update the step-size. Experimental results are presented to validate our proposed variable step-size adaptive Hammerstein algorithm given a real life system and a hypothetical case.
Guided-mode resonant filters and reflectors: Principles, design, and fabrication
Niraula, Manoj
In this dissertation, we overview the operational principles of these resonant periodic structures, discuss the methods of their design and fabrication, and propose and demonstrate novel functionalities for spatial and spectral filtering, and unpolarized wideband reflection. Fashioned with materially sparse gratings, these optical devices are easy to fabricate and integration friendly compared to their traditional multi-layer counterparts making their research and development critical for practical applications. We study, theoretically, modal properties and parametric dependence of resonant periodic bandpass filters operating in the mid- and near-infrared spectral domains. We investigate three different device architectures consisting of single, double, and triple layers based on all-transparent dielectric and semiconductor thin films. We present three modal coupling configurations forming complex mixtures of two or three distinct leaky modes coupling at different evanescent diffraction orders. Our modal analysis demonstrates key attributes of subwavelength periodic thin-film structures in multiple-modal blending to achieve desired transmission spectra. We provide the first experimental demonstration of high-efficiency and narrow-linewidth resonant bandpass filter applying a single patterned silicon layer on a quartz substrate. Its performance corresponds to bandpass filters requiring 15 traditional Si/SiO2 thin-film layers. The feasibility of sparse narrowband, high-efficiency bandpass filters with extremely wide, flat, and low sidebands is thereby demonstrated. The proposed technology is integration-friendly and opens doors for further development in various disciplines and spectral regions where thin-film solutions are traditionally applied. We demonstrate concurrent spatial and spectral filtering as a new outstanding attribute of resonant periodic devices. This functionality is enabled by a unique, near-complete, reflection state that is discrete in both
Photometry Transformation from $RGB$ Bayer Filter System to Johnson-Cousins $BVR$ Filter System
Park, Woojin; Shim, Hyunjin; Le, Huynh Anh N; Im, Myungshin; Chang, Seunghyuk; Yu, Joonkyu
2015-01-01
The $RGB$ Bayer filter system consists of mosaic $R$, $G$, and $B$ filters on the grid of photo sensors which typical commercial DSLR (Digital Single Lens Reflex) cameras and CCD cameras are equipped with. Many unique astronomical data obtained using a $RGB$ Bayer filter system are available, including transient objects, e.g., supernovae, variable stars, and solar system bodies. The utilization of such data in scientific research strongly requires reliable photometry transformation methods. In this work, we develop a series of equations to convert the observed magnitudes in the $RGB$ Bayer filter system ($R_B$, $G_B$, and $B_B$) into the Johnson-Cousins $BVR$ filter system ($B_J$, $V_J$, and $R_C$). The new transformation equations derive the calculated magnitudes in Johnson-Cousins filters ($B_{Jcal}$, $V_{Jcal}$, and $R_{Ccal}$) as functions of magnitudes and colors. The mean differences between the transformed magnitudes and original magnitudes, i.e., the residuals, are $\\Delta(B_J-B_{Jcal})$ = 0.104 mag, ...
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.
Optical Filters, Modulators and Interconnects for Optical Communication Systems
Han, Sang-Kook
This dissertation describes the theoretical and experimental studies on the guided wave optical devices in the InGaAlAs/InP material system and the integration of the optical devices which utilize single quantum well (SQW) as well as multi-quantum well (MQW) structures. This study encompasses the fabrication and characterization of passive ridge waveguides, efficient phase modulators using the quadratic electro-optic effect, as well as efficient, narrow bandwidth wavelength filters. For the purpose of the monolithic integration of an SQW laser diode with an MQW modulator in GaAs/AlGaAs without a complex regrowth process, an impurity-induced layer disordering (IILD) technique is used to facilitate a novel tapered waveguide interconnect structure. The narrow bandwidth and widely tunable wavelength filters are essential for the implementation of highly dense wavelength-division-multiplexers/demultiplexers (WDM) in multi-wavelength optical networks and systems. The vertically stacked directional coupler structure wavelength filter device operating at 1.55 μm which permits the maximum asymmetry possible in directional coupler devices to achieve a narrow bandwidth is presented. The quaternary InGaAlAs layers grown on InP substrate are used and it facilitates larger tunability due to material dispersion. The spectral index method and coupled mode theory are used for theoretical calculations of the filter response. The characteristics of the filter are measured and the tunability of the device is discussed. An array of many filters with different center wavelength in a single chip is studied and a relatively broad range of center wavelength is easily obtained by a small variation in the design of the structure. To achieve an integration of a high gain SQW laser diode and an MQW electroabsorption intensity modulator with a high on/off ratio, we utilize a tapered waveguide interconnect using an IILD technique which permits transfer of the energy generated in an SQW laser
Electrically heated particulate filter preparation methods and systems
Gonze, Eugene V [Pinckney, MI
2012-01-31
A control system that controls regeneration of a particulate filter is provided. The system generally includes a fuel control module that controls injection of fuel into exhaust that passes through the particulate filter. A regeneration module controls current to the particulate filter to initiate regeneration after the fuel has been injected into the exhaust.
A new adaptive filtering algorithm for systems with multiplicative noise
Institute of Scientific and Technical Information of China (English)
WANG Hui-li; CHEN Xi-xin; LU Qian-hao
2005-01-01
Presented here is a new adaptive state filtering algorithm for systems with multiplicative noise. This algorithm estimates the vector state of the system and the statistics of noise when all the statistics of noise are unknown. This filtering algorithm is a simple recursive structure. A simulation example is presented which demonstrates the effectiveness of this filtering algorithm.
Magnetic Bearing Amplifier Output Power Filters for Flywheel Systems
Lebron-Velilla, Ramon C.; Jansen, Ralph H.; Palazzolo, Alan; Thomas, Erwin; Kascak, Peter E.; Birchenough, Arthur G.; Dever, Timothy P.
2003-01-01
Five power filters and two types of power amplifiers were tested for use with active magnetic bearings for flywheel applications. Filter topologies included low pass filters and low pass filters combined with trap filters at the PWM switching frequency. Two state and three state PWM amplifiers were compared. Each system was evaluated based on current magnitude at the switching frequency, voltage magnitude at 500 kHz, and power consumption. The base line system was a two state amplifier without a power filter. The recommended system is a three state power amplifier with a 50 kHz low pass filter and a 27 kHz trap filter. This system uses 5.57 W. It reduces the switching current by an order of magnitude and the 500 kHz voltage by two orders of magnitude. The relative power consumption varied depending on the test condition between 60 to 130 percent of the baseline.
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.
Vial, Benjamin; Zolla, Frédéric; Nicolet, André; Commandré, Mireille; Hecquet, Christophe; Begou, Thomas; Tisserand, Stéphane; Gautier, Sophie; Sauget, Vincent
2014-01-01
We present a modal analysis of metal-insulator-metal (MIM) based metamaterials in the far infrared region. These structures can be used as resonant reflection bandcut spectral filters that are independent of the polarization and direction of incidence because of the excitation of quasimodes (modes associated with a complex frequency) leading to quasi-total absorption. We fabricated large area samples made of chromium nanorod gratings on top of Si/Cr layers deposited on silicon substrate and measurements by Fourier Transform spectrophotometry show good agreement with finite element simulations. A quasimodal expansion method is developed to obtain a reduced order model that fits very well full wave simulations and that highlights excitation conditions of the modes.
Ceramic Hot Gas Filter with Integrated Failsafe System
Energy Technology Data Exchange (ETDEWEB)
Heidenreich, S.; Haag, W.; Walch, A.; Scheibner, B.; Mai, R.; Leibold, H.; Seifert, H.
2002-09-18
In order to integrate a failsafe system and to improve the cleaning intensity a new cleaning method was recently developed, the CPP (coupled pressure pulse) cleaning (Heidenreich et al. 2001). For the CPP method the cleaning system is directly coupled with the filter candles. One feature of this new technique is that the cleaning gas pressure exceeds the system pressure only by 0.05 to 0.1 MPa, whereas in case of conventional jet pulse systems two times the system pressure (at least 0.6 MPa) is standard. The key advantage of the coupled pressure pulse cleaning is that a safety filter for each filter candle can be integrated in the clean gas side of the filter. Thus, a candle failure is not longer a serious problem. The integrated safety filter enables the operation of the filter system also in case a filter candle breaks. This increases the availability of the filter and prevents an unscheduled costly shut-down of the system. In this paper the design of the ceramic filter wit h the failsafe system and the CPP cleaning will be described. The new developed safety filter elements, their pressure drop and their filtration and clogging behavior will be shown. Tests of single system components, of the whole filter system and first experiences of operating this system will be reported.
Spatial filtering with surface plasmon resonance systems
Ghosh, A. K.; Siddharth, V.; Bhagat, M.; Aggarwal, S.; Anurag, P.; Jain, M.
2007-09-01
Surface plasmon resonance based sensors are most useful in measuring the refractive indices of biochemicals. In such sensors a beam of light obliquely incident at an interface of glass and metallic thin film excites resonant plasmon waves in the metal if the angle of incidence or the wavelength is selected properly. The resonance conditions are changed by the refractive indices of any material in contact with the metal film. When resonance occurs the light beam is absorbed strongly. We can easily show that the phenomenon of surface plasmon resonance in such a system acts as a high quality spatial notch or band rejection filter.
de Denus-Baillargeon, Marie-Maude; Schmitt, Thomas; Larouche, Stéphane; Martinu, Ludvik
2014-04-20
The performance of optical coatings may be negatively affected by the deleterious effects of mechanical stress. In this work, we propose an optimization tool for the design of optical filters taking into account both the optical and mechanical properties of the substrate and of the individual deposited layers. The proposed method has been implemented as a supplemental module in the OpenFilters open source design software. It has been experimentally validated by fabricating multilayer stacks using e-beam evaporation, in combination with their mechanical stress assessment performed as a function of temperature. Two different stress-compensation strategies were evaluated: (a) design of two complementary coatings on either side of the substrate and (b) implementing the mechanical properties of the individual materials in the design of the optical coating on one side only. This approach has been tested by the manufacture of a Fabry-Perot etalon used in astronomy while using evaporated SiO2 and TiO2 films. We found that the substrate curvature can be decreased by 85% and 49% for the first and second strategies, respectively.
Adaptive information filtering for dynamic recommender systems
Jin, Ci-Hang; Zhang, Yi-Cheng; Zhou, Tao
2009-01-01
The dynamic environment in the real world calls for the adaptive techniques for information filtering, namely to provide real-time responses to the changes of system data. Where many incremental algorithms are designed for this purpose, they are usually challenged by the worse and worse performance resulted from the cumulative errors over time. In this Letter, we propose two incremental diffusion-based algorithms for the personalized recommendations, which integrate some pieces of local and fast updatings to achieve the approximate results. In addition to the fast responses, the errors of the proposed algorithms do not cumulate over time, that is to say, the global recomputing is unnecessary. This remarkable advantage is demonstrated by several metrics on algorithmic accuracy for two movie recommender systems and a social bookmarking system.
Power System Harmonic Compensation Using Shunt Active Power Filter.
Directory of Open Access Journals (Sweden)
Shiuly Mukherjee
2014-07-01
Full Text Available This paper shows the method of improving the power quality using shunt active power filter. The proposedtopic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is fromhysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Thispaper represents the simulation and analysis of the using three phase three wire system active filter to compensate harmonics .Theproposed shunt active filter model uses balanced non-linear load. This paper successfully lowers the THD within IEEE norms and satisfactorily works to compensatecurrent harmonics.
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.
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.
Application of uniform DFT filter bank in radar jamming system
Institute of Scientific and Technical Information of China (English)
Dai Le; Gao Meiguo
2006-01-01
The principle of Uniform DFT filter bank is presented. Exploiting poly-phase structure, radar jamming system samples the intercepted wideband radar signals through analysis filter bank by different channels and linearly modulates the intercepted radar signal according to the theory of signal and system, then synthesizes the jamming signal through the synthesis filter bank. The method merely requires lower sample frequency, reduces the computational complexity and the data quantity to be processed. The un-ideal filter's influence to the result of signals processing is analyzed by simulating the match filter in radar jamming system.
Habubi, Nadir F.; Mishjil, Khudheir A.; Rashid, Hayfa G.; Mansour, H. L.
Long-wave pass edge filter of high transmittance and wide bandpass have been designed and fabricated using on a single weakly absorbed ZnS thin film material of thickness of about 300 nm which was prepared by using the flash evaporation technique. The design was based on characteristic matrix theory, taking into account the effect of dispersion phenomena for all spectral wavelength.
Development and Analysis of Compact Lowpass Filter for UWB Systems
Directory of Open Access Journals (Sweden)
Rangaswamy Nakkeeran
2012-06-01
Full Text Available This paper presents a developed compact lowpass filter which is devised by concatenating 'T' and inverted 'T' open stubs on a microstrip line. They are combined to enhance the bandwidth and also to improve the outband performance. Insertion loss of the developed filter is less than -0.15 dB and the return loss is -30 dB at 2.85 GHz. Stopband performance of the filter is less than -20 dB from 5.4 GHz to 7.8 GHz and provides -3 dB cut-off frequency at 4.5 GHz. The final dimension of the fabricated filter with the above features is only 16.17 mm (length $imes$15.76 mm (width. The response of the developed filter has a good agreement with simulation response.
Filter System Performance in a Tilapia Recirculating System
Directory of Open Access Journals (Sweden)
Cristian Savin
2012-10-01
Full Text Available It is known that recirculating aquaculture systems, although has some advantages, production costs resulting from these production systems are quite high and is mainly due to the filtration system of technological water. Tilapia is one of the most important species in world aquaculture, the second production after carp, because of the advantages it has being reared in any production system: ponds, net-pens, cages, raceways, recirculating systems. Aim of this study was to evaluate the performance of a filter system in a tilapia recirculating system. Experiments were conducted during October – December 2011, during which feeding was done only with feed, Nutra category, ageappropriate granulation. Main physical – chemical parameters of technological water were monitored, pH, dissolved oxygen, nitrite, ammonia and ammonium, both the water entry in the filter and the exit from the filter. Filtration efficiency varied from 2-3% and up to 50-60%, mainly due to rapid loading of the filter and its need for cleaning.
Personalized Service System Based on Hybrid Filtering for Digital Library
Institute of Scientific and Technical Information of China (English)
GAO Fengrong; XING Chunxiao; DU Xiaoyong; WANG Shan
2007-01-01
Personalized service systems are an effective way to help users obtain recommendations for unseen items, within the enormous volume of information available based on their preferences. The most commonly used personalized service system methods are collaborative filtering, content-based filtering, and hybrid filtering. Unfortunately,each method has its drawbacks. This paper proposes a new method which unified partition-based collaborative filtering and meta-information filtering.In partition-based collaborative filtering the user-item rating matrix can be partitioned into low-dimensional dense materces using a matrixclustering algorithm. Recommendations are generated based on these low-dimensional matrices.Additionally,the very low ratings problem can be solved using meta-information filtering. The unified method is applied to a digital resource management system. The experimental results show the high efficiency and good performance of the new approach.
Optimization of the reconstruction and anti-aliasing filter in a Wiener filter system
Wesselink, J.M.; Berkhoff, A.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 filte
Optimization of the reconstruction and anti-aliasing filter in a wiener filter system
Wesselink, J.M.; Berkhoff, A.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 filte
Emergency sacrificial sealing method in filters, equipment, or systems
Brown, Erik P
2014-09-30
A system seals a filter or equipment component to a base and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment component to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.
Emergency sacrificial sealing method in filters, equipment, or systems
Energy Technology Data Exchange (ETDEWEB)
Brown, Erik P.
2017-02-28
A system seals a filter or equipment component to abase and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment component to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.
Optical calculation of correlation filters for a robotic vision system
Knopp, Jerome
1989-01-01
A method is presented for designing optical correlation filters based on measuring three intensity patterns: the Fourier transform of a filter object, a reference wave and the interference pattern produced by the sum of the object transform and the reference. The method can produce a filter that is well matched to both the object, its transforming optical system and the spatial light modulator used in the correlator input plane. A computer simulation was presented to demonstrate the approach for the special case of a conventional binary phase-only filter. The simulation produced a workable filter with a sharp correlation peak.
Nguyen, Duc Toan; Ababtain, Muath; Memon, Imran; Ullah, Anayat; Istock, André; Woidt, Carsten; Xie, Weichang; Lehmann, Peter; Hillmer, Hartmut
2016-11-01
We report on the fabrication of miniaturized NIR spectrometers based on arrays of multiple Fabry-Pérot (FP) filters. The various cavities of different height are fabricated via a single patterning step using high resolution 3D nanoimprint technology. Today, low-cost patterning of extended cavity heights for NIR filters using the conventional spin-coated nanoimprint methodology is not available because of insufficient coating layers and low mobility of the resist materials to fill extended cavity structures. Our investigation focuses on reducing the technological effort for fabrication of homogeneous extended cavities. We study alternative cavity designs, including a new resist and apply large-area 3D nanoimprint based on hybrid mold and UV Substrate Conformal Imprint Lithography (UV-SCIL) to overcome these limitations. We compare three different solutions, i.e. (1) applying multiple spin coating of the resist to obtain thicker initial resist layers, (2) introducing a hybrid cavity (combination of a thin oxide layer and the organic cavity) to compensate the height differences, and (3) optimizing the imprint process with a novel resist material. The imprint results based on these methods demonstrate the implementation of NIR FP filters with high transmission intensity (best single filter transmission >90 %) and small line widths (<5 nm in full width at half maximum).
Directory of Open Access Journals (Sweden)
Duc Toan Nguyen
2016-02-01
Full Text Available Abstract We report on the fabrication of miniaturized NIR spectrometers based on arrays of multiple Fabry-Pérot (FP filters. The various cavities of different height are fabricated via a single patterning step using high resolution 3D nanoimprint technology. Today, low-cost patterning of extended cavity heights for NIR filters using the conventional spin-coated nanoimprint methodology is not available because of insufficient coating layers and low mobility of the resist materials to fill extended cavity structures. Our investigation focuses on reducing the technological effort for fabrication of homogeneous extended cavities. We study alternative cavity designs, including a new resist and apply large-area 3D nanoimprint based on hybrid mold and UV Substrate Conformal Imprint Lithography (UV-SCIL to overcome these limitations. We compare three different solutions, i.e. (1 applying multiple spin coating of the resist to obtain thicker initial resist layers, (2 introducing a hybrid cavity (combination of a thin oxide layer and the organic cavity to compensate the height differences, and (3 optimizing the imprint process with a novel resist material. The imprint results based on these methods demonstrate the implementation of NIR FP filters with high transmission intensity (best single filter transmission >90 % and small line widths (<5 nm in full width at half maximum.
Directory of Open Access Journals (Sweden)
Cui Jia
2017-05-01
Full Text Available With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.
Cui, Jia; Hong, Bei; Jiang, Xuepeng; Chen, Qinghua
2017-05-01
With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.
Distributed Fusion Receding Horizon Filtering in Linear Stochastic Systems
Directory of Open Access Journals (Sweden)
Il Young Song
2009-01-01
Full Text Available This paper presents a distributed receding horizon filtering algorithm for multisensor continuous-time linear stochastic systems. Distributed fusion with a weighted sum structure is applied to local receding horizon Kalman filters having different horizon lengths. The fusion estimate of the state of a dynamic system represents the optimal linear fusion by weighting matrices under the minimum mean square error criterion. The key contribution of this paper lies in the derivation of the differential equations for determining the error cross-covariances between the local receding horizon Kalman filters. The subsequent application of the proposed distributed filter to a linear dynamic system within a multisensor environment demonstrates its effectiveness.
Autonomous Navigation System Using a Fuzzy Adaptive Nonlinear H∞ Filter
Directory of Open Access Journals (Sweden)
Fariz Outamazirt
2014-09-01
Full Text Available Although nonlinear H∞ (NH∞ filters offer good performance without requiring assumptions concerning the characteristics of process and/or measurement noises, they still require additional tuning parameters that remain fixed and that need to be determined through trial and error. To address issues associated with NH∞ filters, a new SINS/GPS sensor fusion scheme known as the Fuzzy Adaptive Nonlinear H∞ (FANH∞ filter is proposed for the Unmanned Aerial Vehicle (UAV localization problem. Based on a real-time Fuzzy Inference System (FIS, the FANH∞ filter continually adjusts the higher order of the Taylor development thorough adaptive bounds and adaptive disturbance attenuation , which significantly increases the UAV localization performance. The results obtained using the FANH∞ navigation filter are compared to the NH∞ navigation filter results and are validated using a 3D UAV flight scenario. The comparison proves the efficiency and robustness of the UAV localization process using the FANH∞ filter.
Lu, Guo-Shin; You, Po-Chin; Lin, Kai-Lun; Hong, Chien-Chong; Liou, Tong-Miin
2014-05-01
This paper presents a self-aligning ink by integrating an inkjet printing technique and heterostructures to fabricate a black matrix with a micrometer-scale tunable thickness. The black matrix is a grid-like structure used in color filters. Traditionally, a black matrix has been fabricated using photolithography techniques, the disadvantages of which are high material consumption, less fabrication flexibility, complex processing procedures, and high chemical pollution. Inkjet printing technology has garnered attention because of its low material costs, high fabrication flexibility, and reduced processing procedures and pollution. In this study, a fabricating process combining an inkjet printing technique with heterostructures to form stripe-arranged and delta-arranged thickness-tunable black matrices has been demonstrated. The deformation and self-aligning process of ink droplet impingement onto gutters are driven by designed heterogeneous surface properties. The minimum track width attained is 10 µm, which is competitive for color filter resolutions for thin-film transistor liquid crystal displays. The developed technology surmounts the bottlenecks of inkjet printing resolution, and saves more than 75% black material than modern photolithography.
Bandpass filters for thermophotovoltaic conversion systems
Energy Technology Data Exchange (ETDEWEB)
Demichelis, F.; Minetti-Mezzetti, E.; Agnello, M.; Perotto, V.
1982-01-01
The design of dielectric-metal-dielectric filters especially suitable for use as wide bandpass filters with a high visible and a low IR transmittance is described. A refining method is applied to optimize the transmittance in the part of the spectrum corresponding to the spectral response of the solar cells and at the same time to preserve a high reflectance at longer wavelengths. These filters can provide a considerable transmittance over a wide band of the spectrum with a very low transmittance in the rejection regions.
Tunable ultra-wide band-stop filter based on single-stub plasmonic-waveguide system
Chen, Zhiquan; Li, Hongjian; Li, Boxun; He, Zhihui; Xu, Hui; Zheng, Mingfei; Zhao, Mingzhuo
2016-10-01
A nanoscale plasmonic filter based on a single-stub coupled metal-dielectric-metal waveguide system is investigated theoretically and numerically. A tunable wide band-stop can be achieved by loading a metal bar into the stub. The band-stop originates from the direct coupling between the resonance modes. The bandwidth and the center wavelength of the band-stop can be tuned by changing the parameters of the metal bar. Compared with previously reported filters, the plasmonic system has the advantages of easy fabrication and compactness. Our results indicate that the proposed system has potential to be utilized in integrated optical circuits and tunable filters.
? filtering for stochastic systems driven by Poisson processes
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.
Li, Peng; Zong, Yichen; Zhang, Yingying; Yang, Mengmeng; Zhang, Rufan; Li, Shuiqing; Wei, Fei
2013-03-01
We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions.We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols
Electrically heated particulate matter filter soot control system
Energy Technology Data Exchange (ETDEWEB)
Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima
2016-03-15
A regeneration system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas and a downstream end. A control module determines a current soot loading level of the PM filter and compares the current soot loading level to a predetermined soot loading level. The control module permits regeneration of the PM filter when the current soot loading level is less than the predetermined soot loading level.
Fabrication of Compact Microstrip Line-Based Balun-Bandpass Filter with High Common-Mode Suppression
Directory of Open Access Journals (Sweden)
Chia-Mao Chen
2014-01-01
Full Text Available A new type of balun-bandpass filter was proposed based on the traditional coupled-line theory and folded open-loop ring resonators (OLRRs configuration. For that, a new device with both filter-type and balun-type characteristics was investigated and fabricated. Both magnetic and electric coupling structures were implemented to provide high performance balun-bandpass responses. The fabricated balun-bandpass filters had a wide bandwidth more than 200 MHz and a low insertion loss less than 2.51 dB at a center frequency of 2.6 GHz. The differences between the two outputs were below 0.4 dB in magnitude and within 180 ± 7° in phase. Also, the balun-bandpass filter presented an excellent common-mode rejection ratio over 25 dB in the passband. An advanced design methodology had been adopted based on EM simulation for making these designed parameters of OLRRs, microstrip lines, and open stubs. The measured frequency responses agreed well with simulated ones.
Load compensation for single phase system using series active filter
African Journals Online (AJOL)
user
transmission system to low voltage distribution system, quite a good number of series ... Keywords: Active power filter (APF), current source type of harmonic load .... voltage source type harmonic loads are having diode rectifier with smoothing.
Ash reduction system using electrically heated particulate matter filter
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.
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.
INTEGRATED PROTECTIVE FABRIC SYSTEM (IPFS) PHASE III PROGRAM: AEROSOL PROTECTION REPORT
2017-08-16
one layer control. It was observed that aerosol swatch measurements showed no correlation to aerosol system test performance for the materials and...the BRHA model employed. It was observed that aerosol swatch measurements showed no correlation to aerosol system test performance for the...was used as a negative control with the purpose of providing a high-efficiency filter to demonstrate that if the suit fabric was highly efficient at
Nonlinear Filtering Preserves Chaotic Synchronization via Master-Slave System
Directory of Open Access Journals (Sweden)
J. S. González-Salas
2013-01-01
Full Text Available We present a study on a class of interconnected nonlinear systems and give some criteria for them to behave like a filter. Some chaotic systems present this kind of interconnected nonlinear structure, which enables the synchronization of a master-slave system. Interconnected nonlinear filters have been defined in terms of interconnected nonlinear systems. Furthermore, their behaviors have been studied numerically and theoretically on different input signals.
Blended particle filters for large-dimensional chaotic dynamical systems.
Majda, Andrew J; Qi, Di; Sapsis, Themistoklis P
2014-05-27
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.
ADAPTIVE FILTER FOR SYSTEM IDENTIFICATION USING QUANTIZATION SCHEMES
Directory of Open Access Journals (Sweden)
Nitesh Mudgal
2012-03-01
Full Text Available The Least Mean Square (LMS Algorithm finds its application in System identification due to its simplicity.Reduction of the complexity of Adaptive Finite Impulse Response(FIR filter had received attention in the area of adative filter. This paper proposes methods of system identification using adaptive filter which are based on a Quantised version of the LMS, namely the Clipped Least Mean Square (CLMS and Modified Clipped Least Mean Square( QX-LMS algorithms. In both Algorithms coefficients of the adaptive filter are adjusted automatically by an adaptive algorithm based on the input signals. This property makes the adaptive filter has an important application in system identification.the Quantized version of Least Mean Square Algorithm increases covergence property as compared to normal Least Mean Square Algorithm.
Energy Technology Data Exchange (ETDEWEB)
Ono, S. [Department of Electrical Engineering, Yamagata University, 4-3-16, Johnan, Yonezawa, Yamagata 992-8510 (Japan)], E-mail: tdn01835@st.yamagata-u.ac.jp; Harada, Y. [JST Satellite Iwate, 3-35-2, Iiokashinden, Morioka, Iwate 020-0852 (Japan); Kato, T.; Saito, A.; Lee, J.H.; Kinouchi, H. [Department of Electrical Engineering, Yamagata University, 4-3-16, Johnan, Yonezawa, Yamagata 992-8510 (Japan); Oba, T.; Yoshizawa, M. [Graduate School of Engineering, Iwate University, 4-3-5, Ueda, Morioka, Iwate 020-8551 (Japan); Ohshima, S. [Department of Electrical Engineering, Yamagata University, 4-3-16, Johnan, Yonezawa, Yamagata 992-8510 (Japan)
2008-09-15
We designed a 5 GHz miniaturized 10-pole Chebyshev-type bandpass filter (BPF) using superconducting microstrip quasi-spiral resonators (QSR) for international mobile telecommunication (IMT)-advanced receiving applications. When we considered the unloaded quality factor (Q{sub u}) of QSR, we found that a 10-pole QSR BPF using single-sided films and a 17-pole QSR BPF using double-sided films can be achieved an insertion loss in simulation of than 0.5 dB. The 10-pole QSR filter was fabricated using a 300 nm thick single-sided MgB{sub 2} film on a c-sapphire substrate by a thermal co-evaporation method. The Au ground plane of the filter was deposited on the other side of the substrate. Simulation and measurement profile data obtained from the passband were in close agreement. We found that the power-handling performance was equivalent to that of other miniaturized filters. We could design multi-pole filters using QSR.
DEFF Research Database (Denmark)
Guan, Xiaowei; Ding, Yunhong; Frandsen, Lars Hagedorn
2015-01-01
An ultra-compact and broadband higher order-mode pass filter in a 1D photonic crystal silicon waveguide is proposed and experimentally demonstrated. The photonic crystal is designed for the lower order mode to work in the photonic band gap, while the higher order mode is located in the air band....... Consequently, light on the lower order mode is prohibited to pass through the filter, while light on a higher order mode can be converted to a Bloch mode in the photonic crystal and pass through the filter with low insertion loss. As an example, we fabricate a similar to 15-mu m-long first-order-mode pass...... filter that filters out the fundamental mode and provides a measured insertion loss of similar to 1.8 dB for the first-order-mode pass signals. The extinction ratio is measured to be around 50 dB (with a variation of +/- 10 dB due to the detection limitation of the measurement setup) in the measured...
Conceptual design study of advanced fuel fabrication systems
Energy Technology Data Exchange (ETDEWEB)
Ken-ya, Tanaka; Shusaku, Kono; Kiyoshi, Ono [Japan Nuclear Cycle Development JNC, Fuel Fabrication System Group, O-Arai Engineering Center, Ibaraki (Japan)
2001-07-01
The fuel fabrication plant images based on the advanced equipment with availability to operate in hot-cell facility are constructed. The characteristics of each fuel fabrication system for economical and environmental are evaluated roughly. The advanced fuel fabrication routes such as simplified pelletizing, vibration compaction and casting process would have the potential for reducing plant construction cost and minimizing the radioactive waste generated from fuel fabrication process. (author)
Federated nonlinear predictive filtering for the gyroless attitude determination system
Zhang, Lijun; Qian, Shan; Zhang, Shifeng; Cai, Hong
2016-11-01
This paper presents a federated nonlinear predictive filter (NPF) for the gyroless attitude determination system with star sensor and Global Positioning System (GPS) sensor. This approach combines the good qualities of both the NPF and federated filter. In order to combine them, the equivalence relationship between the NPF and classical Kalman filter (KF) is demonstrated from algorithm structure and estimation criterion. The main features of this approach include a nonlinear predictive filtering algorithm to estimate uncertain model errors and determine the spacecraft attitude by using attitude kinematics and dynamics, and a federated filtering algorithm to process measurement data from multiple attitude sensors. Moreover, a fault detection and isolation algorithm is applied to the proposed federated NPF to improve the estimation accuracy even when one sensor fails. Numerical examples are given to verify the navigation performance and fault-tolerant performance of the proposed federated nonlinear predictive attitude determination algorithm.
Filter-and-Forward Transparent Relay Design for OFDM Systems
Kim, Donggun; Sung, Youngchul
2012-01-01
In this paper, the filter-and-forward (FF) relay design for orthogonal frequency-division multiplexing (OFDM) transmission systems is considered to improve the system performance over simple amplify-and-forward (AF) relaying. Unlike conventional OFDM relays performing OFDM demodulation and remodulating, to reduce processing complexity, the proposed FF relay directly filters the incoming signal with a finite impulse response (FIR) and forwards the filtered signal to the destination. Two design criteria are considered to optimize the relay filter for given source power allocation. One is to minimize the relay transmit power subject to per-subcarrier signal-to-noise ratio (SNR) constraints and the other is to maximize the worst subcarrier channel SNR subject to the total relay transmit power constraint. It is shown that the two problems reduce to semi-definite programming (SDP) problems. Furthermore, the problem of joint source power allocation and relay filter design is considered for the second criterion, and ...
Hydrogen storage and delivery system development: Fabrication
Energy Technology Data Exchange (ETDEWEB)
Handrock, J.L.; Malinowski, M.E.; Wally, K. [Sandia National Lab., Livermore, CA (United States)
1996-10-01
Hydrogen storage and delivery is an important element in effective hydrogen utilization for energy applications and is an important part of the FY1994-1998 Hydrogen Program Implementation Plan. This project is part of the Field Work Proposal entitled Hydrogen Utilization in Internal Combustion Engines (ICE). The goal of the Hydrogen Storage and Delivery System Development Project is to expand the state-of-the-art of hydrogen storage and delivery system design and development. At the foundation of this activity is the development of both analytical and experimental evaluation platforms. These tools provide the basis for an integrated approach for coupling hydrogen storage and delivery technology to the operating characteristics of potential hydrogen energy use applications. Analytical models have been developed for internal combustion engine (ICE) hybrid and fuel cell driven vehicles. The dependence of hydride storage system weight and energy use efficiency on engine brake efficiency and exhaust temperature for ICE hybrid vehicle applications is examined. Results show that while storage system weight decreases with increasing engine brake efficiency energy use efficiency remains relatively unchanged. The development, capability, and use of a newly developed fuel cell vehicle hydride storage system model will also be discussed. As an example of model use power distribution and control for a simulated driving cycle is presented. An experimental test facility, the Hydride Bed Testing Laboratory (HBTL) has been designed and fabricated. The development of this facility and its use in storage system development will be reviewed. These two capabilities (analytical and experimental) form the basis of an integrated approach to storage system design and development. The initial focus of these activities has been on hydride utilization for vehicular applications.
Fabrication of nanoporous TiO2 filters using organic-inorganic nanocomposites
Kaynar, Mehmet; Delpercio, Ryan; Yassitepe, Emre; Ozcan, Sadan; Shah, S.
2013-03-01
Nanoporous TiO2 filters with 50 nm mean pore size is synthesized by using commercial TiO2 nanoparticles and polyvinylpyrrolidone with an easy and low cost route that did not involve any solvent. Crystal's structure and surface morphologies are studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. X-ray photoelectron microscopy (XPS) is used to confirm the filtering process by analyzing pre- and post-filter affluent containing nanoparticles to simulate the filtration of micrometer (bacteria) and nanometer (virus) species. Greater than 85% filtering efficiency is obtained during the filtering of a mixture of water and 30 nm mean crystallite size of iron oxide nanoparticles. Supported by TUBITAK-BIDEB 2214-Abroad Research Scholarship program.
Printing technologies in fabrication of drug delivery systems
DEFF Research Database (Denmark)
Kolakovic, Ruzica; Viitala, Tapani; Ihalainen, Petri
2013-01-01
INTRODUCTION: There has been increased activity in the field recently regarding the development and research on various printing techniques in fabrication of dosage forms and drug delivery systems. These technologies may offer benefits and flexibility in manufacturing, potentially paving the way...... recent literature where printing techniques are used in fabrication of drug delivery systems. The future perspectives and possible impacts on formulation strategies, flexible dosing and personalized medication of using printing techniques for fabrication of drug delivery systems are discussed.......\
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.
Nonlinear H∞ filtering for interconnected Markovian jump systems
Institute of Scientific and Technical Information of China (English)
Zhang Xiaomei; Zheng Yufan
2006-01-01
The problem of nonlinear H∞ filtering for interconnected Markovian jump systems is discussed. The aim of this note is the design of a nonlinear Markovian jump filter such that the resulting error system is exponentially meansquare stable and ensures a prescribed H∞ performance. A sufficient condition for the solvability of this problem is given in terms of linear matrix inequalities(LMIs). A simulation example is presented to demonstrate the effectiveness of the proposed design approach.
Particle filtering in high-dimensional chaotic systems.
Lingala, Nishanth; Sri Namachchivaya, N; Perkowski, Nicolas; Yeong, Hoong C
2012-12-01
We present an efficient particle filtering algorithm for multiscale systems, which is adapted for simple atmospheric dynamics models that are inherently chaotic. Particle filters represent the posterior conditional distribution of the state variables by a collection of particles, which evolves and adapts recursively as new information becomes available. The difference between the estimated state and the true state of the system constitutes the error in specifying or forecasting the state, which is amplified in chaotic systems that have a number of positive Lyapunov exponents. In this paper, we propose a reduced-order particle filtering algorithm based on the homogenized multiscale filtering framework developed in Imkeller et al. "Dimensional reduction in nonlinear filtering: A homogenization approach," Ann. Appl. Probab. (to be published). In order to adapt the proposed algorithm to chaotic signals, importance sampling and control theoretic methods are employed for the construction of the proposal density for the particle filter. Finally, we apply the general homogenized particle filtering algorithm developed here to the Lorenz'96 [E. N. Lorenz, "Predictability: A problem partly solved," in Predictability of Weather and Climate, ECMWF, 2006 (ECMWF, 2006), pp. 40-58] atmospheric model that mimics mid-latitude atmospheric dynamics with microscopic convective processes.
Grant, Joseph; Jackson, Kurt V.; Wang, Y.; Sharma, A.; Burdine, Robert V. (Technical Monitor)
2002-01-01
Fiber Optic Bragg Grating taps are fabricated and characterized at various wavelengths using a modified Talbot interferometric technique. Gratings are fabricated by tilting the photosensitive fiber to angles up to 45 degrees w.r.t. the writing angle. Diffraction characteristics of the tilted grating is monitored in first and second orders.
Integrated Analogic Filter Tuning System Design
Directory of Open Access Journals (Sweden)
Karolis Kiela
2016-06-01
Full Text Available Parameters of integrated analog filters can vary due to temperatu-re change, IC process variation and therefore they should have dedicated tuning circuits that compensate these imperfections. A method is proposed that speeds up switched resistor bank design while taking into account the required tuning range and step size. A novel counter structure is used in the tuning circuit that is ba-sed on successive approximation approach. The proposed swit-ched resistor design method and tuning circuit are designed in 0.18 μm CMOS technology and verified. Results are compared to existing tuning circuit designs.
Robust filtering and fault detection of switched delay systems
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...
Fabrication and Characterization of Efficient Optical Filter Arrays Implemented by 3D Nanoimprint
Memon, Imran
2016-01-01
In dieser Arbeit werden optische Filterarrays für hochqualitative spektroskopische Anwendungen im sichtbaren (VIS) Wellenlängenbereich untersucht. Die optischen Filter, bestehend aus Fabry-Pérot (FP)-Filtern für hochauflösende miniaturisierte optische Nanospektrometer, basieren auf zwei hochreflektierenden dielektrischen Spiegeln und einer zwischenliegenden Resonanzkavität aus Polymer. Jeder Filter erlaubt einem schmalbandigem spektralen Band (in dieser Arbeit Filterlinie genannt) ,abhängig v...
Filtering nonlinear dynamical systems with linear stochastic models
Harlim, J.; Majda, A. J.
2008-06-01
An important emerging scientific issue is the real time filtering through observations of noisy signals for nonlinear dynamical systems as well as the statistical accuracy of spatio-temporal discretizations for filtering such systems. From the practical standpoint, the demand for operationally practical filtering methods escalates as the model resolution is significantly increased. For example, in numerical weather forecasting the current generation of global circulation models with resolution of 35 km has a total of billions of state variables. Numerous ensemble based Kalman filters (Evensen 2003 Ocean Dyn. 53 343-67 Bishop et al 2001 Mon. Weather Rev. 129 420-36 Anderson 2001 Mon. Weather Rev. 129 2884-903 Szunyogh et al 2005 Tellus A 57 528-45 Hunt et al 2007 Physica D 230 112-26) show promising results in addressing this issue; however, all these methods are very sensitive to model resolution, observation frequency, and the nature of the turbulent signals when a practical limited ensemble size (typically less than 100) is used. In this paper, we implement a radical filtering approach to a relatively low (40) dimensional toy model, the L-96 model (Lorenz 1996 Proc. on Predictability (ECMWF, 4-8 September 1995) pp 1-18) in various chaotic regimes in order to address the 'curse of ensemble size' for complex nonlinear systems. Practically, our approach has several desirable features such as extremely high computational efficiency, filter robustness towards variations of ensemble size (we found that the filter is reasonably stable even with a single realization) which makes it feasible for high dimensional problems, and it is independent of any tunable parameters such as the variance inflation coefficient in an ensemble Kalman filter. This radical filtering strategy decouples the problem of filtering a spatially extended nonlinear deterministic system to filtering a Fourier diagonal system of parametrized linear stochastic differential equations (Majda and Grote
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.
Sound attenuation using microelectromechanical systems fabricated acoustic metamaterials
Yunker, William N.; Stevens, Colin B.; Flowers, George T.; Dean, Robert N.
2013-01-01
Unlike traditional rotational gyroscopes, microelectromechanical systems (MEMS) gyroscopes use a vibrating proof mass rather than a rotational mass to sense changes in angular rate. They are also smaller and less expensive than traditional gyroscopes. MEMS gyroscopes are known to be susceptible to the effects of acoustic noise, in particular high frequency and high power acoustic noise. Most notably, this has been proven true in aerospace applications where the noise can reach levels in excess of 120 dB and the noise frequency can exceed 20 kHz. The typical resonant frequency for the proof mass of a MEMS gyroscope is between 3 and 20 kHz. High power, high frequency acoustic noise can disrupt the output signal of the gyroscope to the point that the output becomes unreliable. In recent years, considerable research has focused on the fascinating properties found in metamaterials. A metamaterial is an artificially fabricated device or structure that is engineered to produce desired material responses that can either mimic known behaviors or produce responses that do not occur naturally in materials found in nature. Acoustic metamaterials, in particular, have shown great promise in the field of sound attenuation. This paper proposes a method to mitigate the performance degradation of the MEMS gyroscope in the presence of high power, high frequency acoustic noise by using a new acoustic metamaterial in the form of a two-dimensional array of micromachined Helmholtz resonators. The Helmholtz resonators are fabricated in a silicon wafer using standard MEMS manufacturing techniques and are designed to attenuate sound at the resonant frequency of the gyroscope proof mass. The resonator arrays were diced from the silicon wafer in one inch squares and assembled into a box open on one end in a manner to attenuate sound on all sides of the gyroscope, and to seal the gyroscope inside the box. The resulting acoustic metamaterial device was evaluated in an acoustic chamber and was
Potential Worst-case System for Testing EMI Filters Tested on Simple Filter Models
Directory of Open Access Journals (Sweden)
Z. Raida
2008-09-01
Full Text Available This paper deals with the approximate worst-case test method for testing the insertion loss of the EMI filters. The systems with 0.1 ÃŽÂ© and 100 ÃŽÂ© impedances are usually used for this testing. These systems are required by the international CISPR 17 standard. The main disadvantage of this system is the use of two impedance transformers. Especially the impedance transformer with 0.1 ÃŽÂ© output impedance is not easy to be produced. These transformers have usually narrow bandwidth. This paper discusses the alternative system with 1 ÃŽÂ© and 100 ÃŽÂ© impedances. The performance of these systems was tested on several filtersÃ¢Â€Â™ models and the obtained data are depicted, too. The performance comparison of several filters in several systems is also included. The performance of alternate worst-case system is discussed in the conclusion.
Direct laser additive fabrication system with image feedback control
Energy Technology Data Exchange (ETDEWEB)
Griffith, Michelle L. (Albuquerque, NM); Hofmeister, William H. (Nashville, TN); Knorovsky, Gerald A. (Albuquerque, NM); MacCallum, Danny O. (Edgewood, NM); Schlienger, M. Eric (Albuquerque, NM); Smugeresky, John E. (Pleasanton, CA)
2002-01-01
A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.
Energy Technology Data Exchange (ETDEWEB)
Zhao, T; Drzymala, R [Washington University School of Medicine, St. Louis, MO (United States)
2015-06-15
Purpose: The purpose of this project was to devise a practical fabrication process for passive scatter proton beam compensation filters (CF) that is competitive in time, cost and effort using 3D printing. Methods: DICOM compensator filter files for a proton beam were generated by our Eclipse (Varian, Inc.) treatment planning system. The compensator thickness specifications were extracted with in-house software written in Matlab (MathWorks, Inc.) code and written to a text file which could be read by the Rhinoceros 5, computer-aided design (CAD) package (Robert McNeel and Associates), which subsequently generated a smoothed model in a STereoLithographic also known as a Standard Tesselation Language file (STL). The model in the STL file was subsequently refined using Netfabb software and then converted to printing instructions using Cura. version 15.02.1. for our 3D printer. The Airwolf3D, model HD2x, fused filament fabrication (FFF) 3D printer (Airwolf3D.com) was used for our fabrication system with a print speed of 150mm per second. It can print in over 22 different plastic filament materials in a build volume of 11” x 8” x 12”. We choose ABS plastic to print the 3D model of the imprint for our CFs. Results: Prints of the CF could be performed at a print speed of 70mm per second. The time to print the 3D topology for the CF for the 14 cm diameter snout of our Mevion 250 proton accelerator was less than 3 hours. The printed model is intended to subsequently be used as a mold to imprint a molten wax cylindrical to form the compensation after cooling. The whole process should be performed for a typical 3 beam treatment plan within a day. Conclusion: Use of 3D printing is practical and can be used to print a 3D model of a CF within a few hours.
Notch filters for port-Hamiltonian systems
Dirksz, Daniel; Scherpen, Jacquelien M.A.; van der Schaft, Abraham; Steinbuch, M.
2012-01-01
Network modeling of lumped-parameter physical systems naturally leads to a geometrically defined class of systems, i.e., port-Hamiltonian (PH) systems [4, 6]. The PH modeling framework describes a large class of (nonlinear) systems including passive mechanical systems, electrical systems, electromec
SMS Spam Filtering Technique Based on Artificial Immune System
Directory of Open Access Journals (Sweden)
Tarek M Mahmoud
2012-03-01
Full Text Available The Short Message Service (SMS have an important economic impact for end users and service providers. Spam is a serious universal problem that causes problems for almost all users. Several studies have been presented, including implementations of spam filters that prevent spam from reaching their destination. Nave Bayesian algorithm is one of the most effective approaches used in filtering techniques. The computational power of smart phones are increasing, making increasingly possible to perform spam filtering at these devices as a mobile agent application, leading to better personalization and effectiveness. The challenge of filtering SMS spam is that the short messages often consist of few words composed of abbreviations and idioms. In this paper, we propose an anti-spam technique based on Artificial Immune System (AIS for filtering SMS spam messages. The proposed technique utilizes a set of some features that can be used as inputs to spam detection model. The idea is to classify message using trained dataset that contains Phone Numbers, Spam Words, and Detectors. Our proposed technique utilizes a double collection of bulk SMS messages Spam and Ham in the training process. We state a set of stages that help us to build dataset such as tokenizer, stop word filter, and training process. Experimental results presented in this paper are based on iPhone Operating System (iOS. The results applied to the testing messages show that the proposed system can classify the SMS spam and ham with accurate compared with Nave Bayesian algorithm.
40 CFR 141.710 - Bin classification for filtered systems.
2010-07-01
... Cryptosporidium Treatment Technique Requirements § 141.710 Bin classification for filtered systems. (a) Following... systems must determine their initial bin classification from the following table and using the... systems must report their initial bin classification under paragraph (c) of this section to the State...
Li, Peng; Zong, Yichen; Zhang, Yingying; Yang, Mengmeng; Zhang, Rufan; Li, Shuiqing; Wei, Fei
2013-04-21
We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions.
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
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.
Long Focal Length Large Mirror Fabrication System
Bennett, H. E.
2003-01-01
The goals of this ambitious program are (1) to develop systems to make large superpolished optical mirrors, (2) to develop low scatter polishing techniques using centrifugal elutriation, (3) to develop a means of measuring scatter at any point on the mirror, (4) to polish a Hindle sphere to measure the optical figure of a one meter diameter convex mandrel, and (5) to fabricate low scatter, large adaptive optic graphite filled, cyanate ester replica transfer mirrors using these mandrels. Deliverables are a 30 cm diameter superpolished composite AO mirror. We fabricated a 1/3rd meter superpolished zerodur flat mandrel and with the support of our major subcontractor, Composite Mirror Applications Inc (CMA) we have demonstrated a 30 cm lightweight cyanate ester mirror with an rms microroughness between 0.6 and 0.8 nm and 8 faceplate influence function of 5 cm. The influence function was chosen to be comparable to the atmospheric correlation coefficient r(sub 0) which is about 5 cm at sea level. There was no print-thru of the graphite fibers in the cyanate ester surface (the bane of many previous efforts to use cyanate ester mirrors). Our subcontractor has devised a means for developing a 30-50 nm thick layer of graphite free pure ester resin on the surface of the mirrors. This graphite fiber filled material has a thermal expansion coefficient in the 10(exp -8) centimeter per Kelvin range (the same range of expansion coefficient as Zerodur and ULE glasses) and does not take up water and swell, so it is a nearly ideal mirror material in these areas. Unfortunately for these 0.8mm thick faceplates, the number of plies is not enough to result in isometric coverage. Isolated figure irregularities can appear, making it necessary to go to thicker faceplates. The influence function will then only approximate the length of r(sub 0), at higher altitudes or longer wavelengths. The influence function goes as the cube of the thickness, so we are now making a faceplate optimized for
An Adaptive Filtering System Configurations and Architecture on Reconfigurable Platform
Directory of Open Access Journals (Sweden)
Dipen B. Patel
2014-03-01
Full Text Available This paper proposed the implementation of adaptive filters on reconfigurable platform. Adaptive filter is an essential part of digital signal systems, have been widely used and its implementation takes a great deal, there is no dedicated IC for adaptive filter. When FPGA implemented in such area, provides a lot of facilities to the designers and also offer a better solution for filtering the data. Adaptive signal processing evolved from the techniques developed to enable the adaptive control of time- varying systems. Filtering data in real-time requires dedicated hardware to meet demanding time requirements and provide the highest processing performance, but is inflexible for changes. When a design demands the use of a DSP, design adaptability is crucial, then FPGA may offer a better solution. Reconfigurable hardware devices offer both the flexibility of computer software, and the ability to construct custom high performance computing circuits. Adaptive filter implemented using Field Programmable Gate Arrays (FPGAs due to some of their attractive advantages include flexibility and programmability, availability of tens to hundreds of hardware multipliers available on a chip. Keywords -
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.
Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems.
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.
Nonlinear dynamical system identification using unscented Kalman filter
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.
Identification of linear stochastic systems through projection filters
Chen, Chung-Wen; Huang, Jen-Kuang; Juang, Jer-Nan
1992-01-01
A novel method is presented for identifying a state-space model and a state estimator for linear stochastic systems from input and output data. The method is primarily based on the relationship between the state-space model and the finite-difference model of linear stochastic systems derived through projection filters. It is proved that least-squares identification of a finite difference model converges to the model derived from the projection filters. System pulse response samples are computed from the coefficients of the finite difference model.
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.
[Sick building syndrome and HVAC system: MVOC from air filters].
Schleibinger, H W; Wurm, D; Möritz, M; Böck, R; Rüden, H
1997-08-01
Growth and emissions of volatile metabolites of microorganisms on air filters are suspected to contribute to health complaints in ventilated rooms. To prove the microbiological production of volatile organic compounds (MVOC), concentrations of aldehydes and ketones were determined in two large HVAC systems. The in situ derivated aldehydes and ketones (as 2,4-dinitrophenyl-hydrazones) were analysed by HPLC and UV detection. The detection limit of each compound was 1 ppb (margin of error HVAC systems. First results show that the compounds formaldehyde, acetaldehyde and acetone could be detected before and after the filters. The concentrations of these VOC after the filters were significantly increased--as a mean over twenty measurements--, especially as far as filters made of glass fibre are concerned. However the found concentrations were low and mostly comparable to outdoor findings. In simultaneous laboratory experiments pieces of used filter material of one HVAC system and unused filter pieces (for blank values) were examined in small incubation chambers to investigate the possible production of MVOC. For the incubation a temperature of 20 degrees C and a relative humidity of 95% was chosen. In these experiments an almost identical spectrum of compounds (formaldehyde and acetone) was found as in the field measurements. The concentrations of these compounds were higher in the chambers with the used filter pieces. The concentration of acetone ranged up to almost 12 mg/m3.--As our field experiments correspond with our laboratory experiments, we assume that the microbial production of volatile organic compounds in HVAC systems under operating conditions is possible.
Filtering and control of stochastic jump hybrid systems
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...
Electrically heated particulate filter diagnostic systems and methods
Gonze, Eugene V [Pinckney, MI
2009-09-29
A system that diagnoses regeneration of an electrically heated particulate filter is provided. The system generally includes a grid module that diagnoses a fault of the grid based on at least one of a current signal and a voltage signal. A diagnostic module at least one of sets a fault status and generates a warning signal based on the fault of the grid.
FORTRAN IV Digital Filter Design Programs. Digital Systems Education Project.
Reuss, E.; And Others
The goals of the Digital Systems Education Project (DISE) include the development and distribution of educational/instructional materials in the digital systems area. Toward that end, this document contains three reports: (1) A FORTRAN IV Design Program for Low-Pass Butterworth and Chebychev Digital Filters; (2) A FORTRAN IV Design Program for…
Control and filtering for semi-Markovian jump systems
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.
Microscope system with on axis programmable Fourier transform filtering
Martínez, José Luis; García-Martínez, Pascuala; Moreno, Ignacio
2017-02-01
We propose an on-axis microscope optical system to implement programmable optical Fourier transform image processing operations, taking advantage of phase and polarization modulation of a liquid crystal on silicon (LCOS) display. We use a Hamamatsu spatial light modulator (SLM), free of flickering, which therefore can be tuned to fully eliminate the zero order component of the encoded diffractive filter. This allows the realization of filtering operation on axis (as opposed to other systems in the literature that require operating off axis), therefore making use of the full space bandwidth provided by the SLM. The system is first demonstrated by implementing different optical processing operations based on phase-only blazed gratings such as phase contrast, band-pass filtering, or additive and substractive imaging. Then, a simple Differential interference contrast (DIC) imaging is obtained changing to a polarization modulation scheme, achieved simply by selecting a different incident state of polarization on the incident beam.
Staged fluidized-bed combustion and filter system
Mei, Joseph S.; Halow, John S.
1994-01-01
A staged fluidized-bed combustion and filter system 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.
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.
Filtering and control for classes of two-dimensional systems
Wu, Ligang
2015-01-01
This book focuses on filtering, control and model-reduction problems for two-dimensional (2-D) systems with imperfect information. The time-delayed 2-D systems covered have system parameters subject to uncertain, stochastic and parameter-varying changes. After an initial introduction of 2-D systems and the ideas of linear repetitive processes, the text is divided into two parts detailing: · general theory and methods of analysis and optimal synthesis for 2-D systems; and · application of the general theory to the particular case of differential/discrete linear repetitive processes. The methods developed provide a framework for stability and performance analysis, optimal and robust controller and filter design and model approximation for the systems considered. Solutions to the design problems are couched in terms of linear matrix inequalities. For readers interested in the state of the art in linear filtering, control and model reduction, Filtering and Control for Classes of ...
Power system harmonics and passive filter designs
Das, J C
2015-01-01
J.C. Das is a consultant of electrical power systems at Power Systems Studies, Inc., USA. He is Life Fellow of IEEE (UK), Fellow of IET (India), and has authored approximately sixty technical papers and published 190 study reports of real-world power systems. He is the author of three books including ARC Flash Hazard Analysis and Mitigation. He is a registered P.E. in the states of Georgia and Oklahoma, C.Eng. in UK, and Eur Ing in Europe. J. C. Das is also a member of CIGRE, Federation of European Engineers, and other technical associations and organizations.
Harris, Nicholas C; Simbula, Angelica; Pant, Mihir; Galli, Matteo; Baehr-Jones, Tom; Hochberg, Michael; Englund, Dirk; Bajoni, Daniele; Galland, Christophe
2014-01-01
We demonstrate the generation of quantum-correlated photon-pairs combined with the spectral filtering of the pump field by more than 95dB using Bragg reflectors and electrically tunable ring resonators. Moreover, we perform demultiplexing and routing of signal and idler photons after transferring them via a fiber to a second identical chip. Non-classical two-photon temporal correlations with a coincidence-to-accidental ratio of 50 are measured without further off-chip filtering. Our system, fabricated with high yield and reproducibility in a CMOS process, paves the way toward truly large-scale quantum photonic circuits by allowing sources and detectors of single photons to be integrated on the same chip.
Photonic crystal channel drop filter based on ring-shaped defects for DWDM systems
Dideban, Ali; Habibiyan, Hamidreza; Ghafoorifard, Hassan
2017-03-01
This paper presents a novel configuration of channel drop filters based on two-dimensional photonic crystal slabs in silicon-on-insulator platforms. The structure is composed of two photonic crystal line-defect waveguides as input and output ports, along with an L3 cavity with ring-shaped border holes. The effects of structural parameters and fabrication errors on resonance frequency and drop efficiency are investigated. Band structure and propagation of electromagnetic field through device are calculated by plane wave expansion and finite-difference time-domain methods. The results show that the quality factor and line-width of output signal are 5690 and 0.27 nm, respectively, indicating that the proposed filter can be properly used in dense wavelength division multiplexing systems with 0.8 nm channel spacing.
OTA & CCII-Based Control System of Shunt Active Power Filter Using in Three-Phase Three-wire System
Vanichprapa, Sombat; Prapanavarat, Cherdchai; Chipipop, Boonruk
2008-10-01
This paper presents the implementation of the OTA (Operational Transconductance Amplifier) & CCII (Second generation Current Conveyor)—based control system of active power filter (APF). The three-phase shunt PWM VSI-APF is used as the power circuit for simple control. This proposed control system using OTA & CCII-based circuits since it has the advantage of its adaptive control, real-time processing and it has wide bandwidth which can work with the high frequency power switches in order to eliminate the higher order of harmonics, moreover, it can be fabricated in one single chip by using CMOS technology. Theoretical analysis, design and simulation results are provided.
Using Kalman filters to reduce noise from RFID location system.
Abreu, Pedro Henriques; Xavier, José; Silva, Daniel Castro; 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).
Method and System for Temporal Filtering in Video Compression Systems
Lu, Ligang; He, Drake; Jagmohan, Ashish; Sheinin, Vadim
2011-01-01
Three related innovations combine improved non-linear motion estimation, video coding, and video compression. The first system comprises a method in which side information is generated using an adaptive, non-linear motion model. This method enables extrapolating and interpolating a visual signal, including determining the first motion vector between the first pixel position in a first image to a second pixel position in a second image; determining a second motion vector between the second pixel position in the second image and a third pixel position in a third image; determining a third motion vector between the first pixel position in the first image and the second pixel position in the second image, the second pixel position in the second image, and the third pixel position in the third image using a non-linear model; and determining a position of the fourth pixel in a fourth image based upon the third motion vector. For the video compression element, the video encoder has low computational complexity and high compression efficiency. The disclosed system comprises a video encoder and a decoder. The encoder converts the source frame into a space-frequency representation, estimates the conditional statistics of at least one vector of space-frequency coefficients with similar frequencies, and is conditioned on previously encoded data. It estimates an encoding rate based on the conditional statistics and applies a Slepian-Wolf code with the computed encoding rate. The method for decoding includes generating a side-information vector of frequency coefficients based on previously decoded source data and encoder statistics and previous reconstructions of the source frequency vector. It also performs Slepian-Wolf decoding of a source frequency vector based on the generated side-information and the Slepian-Wolf code bits. The video coding element includes receiving a first reference frame having a first pixel value at a first pixel position, a second reference frame
Engineering fabrics in transportation construction
Herman, S. C.
1983-11-01
The following areas are discussed: treatments for reduction of reflective cracking of asphalt overlays on jointed-concrete pavements in Georgia; laboratory testing of fabric interlayers for asphalt concrete paving: interim report; reflection cracking models: review and laboratory evaluation of engineering fabrics; optimum-depth method for design of fabric-reinforced unsurfaced roads; dynamic test to predict field behavior of filter fabrics used in pavement subdrains; mechanism of geotextile performance in soil-fabric systems for drainage and erosion control; permeability tests of selected filter fabrics for use with a loess-derived alluvium; geotextile filter criteria; use of fabrics for improving the placement of till on peat foundation; geotextile earth-reinforced retaining wall tests: Glenwood Canyon, Colorado; New York State Department of Transportation's experience and guidelines for use of geotextiles; evaluation of two geotextile installations in excess of a decade old; and, long-term in situ properties of geotextiles.
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...
Modeling and Testing of a PV/T hybrid system with Water based Optical Filter
Directory of Open Access Journals (Sweden)
Sachin Gupta
2015-12-01
Full Text Available A theoretical model has been developed for the Non-imaging V-trough hybrid PV/T concentrator systems along with optical filter and validated with the designed and fabricated system to assess over all thermal efficiency of the PV/T system. A V-trough concentrator system has been developed for two axes tracking. Commercially available solar modules were evaluated for their usability under 2-sun concentration. V-trough concentrator with geometric concentration ratio of 2 (2-sun, we are getting an average overall efficiency of the PV/T system increased by 23.54 % extra overall thermal efficiency of the PV/T system as compared to the solar module efficiency at standard test conditions.
Joe, Yun Haeng; Woo, Kyoungja; Hwang, Jungho
2014-09-15
In this study, SiO2 nanoparticles surface coated with Ag nanoparticles (SA particles) were fabricated to coat a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter were evaluated against aerosolized bacteriophage MS2 in a continuous air flow condition. A mathematical approach was developed to measure the anti-viral ability of the filter with various virus deposition times. Moreover, two quality factors based on the anti-viral ability of the filter, and a traditional quality factor based on filtration efficiency, were calculated. The filtration efficiency and pressure drop increased with decreasing media velocity and with increasing SA particle coating level. The anti-viral efficiency also increased with increasing SA particle coating level, and decreased by with increasing virus deposition time. Consequently, SA particle coating on a filter does not have significant effects on filtration quality, and there is an optimal coating level to produce the highest anti-viral quality.
Filtering for linear systems with noise correlation and its application to singular systems
Institute of Scientific and Technical Information of China (English)
Wu Jian-Rong; Song Shi-Ji
2004-01-01
In this paper, an optimal filter for a stochastic linear system with previous stage noise correlation is designed.Based on this result, together with the decomposition techniques of the stochastic singular linear system, the design of an optimal filter for a stochastic singular linear system is given.
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 Particle Filtering Approach to Change Detection for Nonlinear Systems
Directory of Open Access Journals (Sweden)
P. S. Krishnaprasad
2004-11-01
Full Text Available We present a change detection method for nonlinear stochastic systems based on particle filtering. We assume that the parameters of the system before and after change are known. The statistic for this method is chosen in such a way that it can be calculated recursively while the computational complexity of the method remains constant with respect to time. We present simulation results that show the advantages of this method compared to linearization techniques.
Delay-dependent decentralized H∞ filtering for uncertain interconnected systems
Institute of Scientific and Technical Information of China (English)
Chen Ning; Gui Weihua; Zhang Xiaofeng
2008-01-01
This article considers delay dependent decentralized H∞ filtering for a class of uncertain intercon nected systems,where the uncertainties are assumed to be time varying and satisfy the norm-bounded conditions.First,combining the Lyapunov-Krasovskii functional approach and the delay integral inequality of matrices,a sufficient condition of the existence of the robust decentralized H∞ filter is derived,which makes the error systems asymptotically stable and satisfies the H∞ norm of the transfer function from noise input to error output less than the specified up-bound on the basis of the form of uncertainties.Then,the above sufficient condition is transformed to a system of easily solvable LMIs via a series of equivalent transformation.Finally,the numerical simulation shows the efficiency of the main results.
Nonlinear stochastic systems with incomplete information filtering and control
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...
Directory of Open Access Journals (Sweden)
E.M.S. Azzam
2013-12-01
Full Text Available In the present work, the nanoclay composites were fabricated using the synthesized poly 6-(3-aminophenoxy hexane-1-thiol, poly 8-(3-aminophenoxy octane-1-thiol and poly 10-(3-aminophenoxy decane-1-thiol surfactants with gold nanoparticles. The polymeric thiol surfactants were first assembled on gold nanoparticles and then impregnated into the clay matrix. Different spectroscopic and microscopic techniques such as X-ray diffraction (XRD, Scanning electron microscope (SEM and Transmission microscope (TEM were used to characterize the fabricated nanoclay composites. The results showed that the polymeric thiol surfactants assembled on gold nanoparticles are located in the interlayer space of the clay mineral and affected the clay structure.
Fast recursive filters for simulating nonlinear dynamic systems.
van Hateren, J H
2008-07-01
A fast and accurate computational scheme for simulating nonlinear dynamic systems is presented. The scheme assumes that the system can be represented by a combination of components of only two different types: first-order low-pass filters and static nonlinearities. The parameters of these filters and nonlinearities may depend on system variables, and the topology of the system may be complex, including feedback. Several examples taken from neuroscience are given: phototransduction, photopigment bleaching, and spike generation according to the Hodgkin-Huxley equations. The scheme uses two slightly different forms of autoregressive filters, with an implicit delay of zero for feedforward control and an implicit delay of half a sample distance for feedback control. On a fairly complex model of the macaque retinal horizontal cell, it computes, for a given level of accuracy, one to two orders of magnitude faster than the fourth-order Runge-Kutta. The computational scheme has minimal memory requirements and is also suited for computation on a stream processor, such as a graphical processing unit.
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.
Three Filtered Vacuum Arc Plasma Sources Deposition & Implantation System
Institute of Scientific and Technical Information of China (English)
WU Xian-ying; ZHANG Hui-xing; LI Qiang
2004-01-01
A deposition & implantation system, which includes three filtered vacuum arc plasma sources, has been built. Vacuum arc discharge is used to produce high-density metal plasma; Curved magnetic filtering technique is used to transfer the plasma into out-of-sight vacuum chamber and reduce macro-particles from the vacuum arc plasma in order to drastically reduce the macro-particles contamination of the films. The up to 30 kV negative bias applied to the target can be used for ion implantation in order to improve the film adhesion; or for ion sputtering to clear the substrate surface. The 0 to 300 V negative bias can be used to adjust the ion energy which forming films. The system is designed for various thin films synthesizing, such as single-layer, compound layer, multi-layer films. It's principle, components and applications are described in the literature.
Distributed Systems and Applications of Information Filtering and Retrieval
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 Technique for Shunt Active Filter meld micro grid System
Directory of Open Access Journals (Sweden)
A. Lumani
2015-08-01
Full Text Available The proposed system presents a control technique for a micro grid connected hybrid generation system ith case study interfaced with a three phase shunt active filter to suppress the current harmonics and reactive power present in the load using PQ Theory with ANN controller. This Hybrid Micro Grid is developed using freely renewable energy resources like Solar Photovoltaic (SPV and Wind Energy (WE. To extract the maximum available power from PV panels and wind turbines, Maximum power point Tracker (MPPT has been included. This MPPT uses the “Standard Perturbs and Observe” technique. By using PQ Theory with ANN Controller, the Reference currents are generated which are to be injected by Shunt active power filter (SAPFto compensate the current harmonics in the non linear load. Simulation studies shows that the proposed control technique performs non-linear load current harmonic compensation maintaining the load current in phase with the source voltage.\\
Object Tracking System Using Approximate Median Filter, Kalman Filter and Dynamic Template Matching
Directory of Open Access Journals (Sweden)
G. Mallikarjuna Rao
2014-04-01
Full Text Available In this work, we dealt with the tracking of single object in a sequence of frames either from a live camera or a previously saved video. A moving object is detected frame-by-frame with high accuracy and efficiency using Median approximation technique. As soon as the object has been detected, the same is tracked by kalman filter estimation technique along with a more accurate Template Matching algorithm. The templates are dynamically generated for this purpose. This guarantees any change in object pose which does not be hindered from tracking procedure. The system is capable of handling entry and exit of an object. Such a tracking scheme is cost effective and it can be used as an automated video conferencing system and also has application as a surveillance tool. Several trials of the tracking show that the approach is correct and extremely fast, and it's a more robust performance throughout the experiments.
RD on 3D Sensors and MicroFabricated Systems
Da Via, C
2013-01-01
The aim of this proposed R&D Collaboration is the design, fabrication and industrialization of a new generation of low mass detector systems based on silicon micro-fabrication techniques. The main objective is the validation of such systems in HL-LHC detectors upgrades. In particular the collaboration would like to focus on the following research topics: • Novel 3D sensors layouts, with enhanced signal properties, high speed and active edges; •Integrated micro-channel cooling for effective low mass module thermal management; •System integration, simulation and reliability studies at experiments’ operational conditions.
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.
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...... the stability of power system. State estimation with EKF and UKF methods can be used for monitoring and estimating the dynamic state variables of multi-machine power systems, which are generator rotor speed and rotor angle. This paper uses Powerfactory to solve power flow analysis of simulations, then a non......-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...
Fabrication of a glycerol from CO2 reaction system, supplement
Weiss, A. H.
1973-01-01
The fabrication, installation, and testing of a glycerol hydrogenation and a CO2 hydrogenation - CH4 partial oxidation units are reported. The glycerol system proved to be operational while the CO2 system was installed but not bought on operational steam.
Micro- and nano-fabricated implantable drug-delivery systems
Meng, Ellis; Hoang, Tuan
2012-01-01
Implantable drug-delivery systems provide new means for achieving therapeutic drug concentrations over entire treatment durations in order to optimize drug action. This article focuses on new drug administration modalities achieved using implantable drug-delivery systems that are enabled by micro- and nano-fabrication technologies, and microfluidics. Recent advances in drug administration technologies are discussed and remaining challenges are highlighted.
Energy Technology Data Exchange (ETDEWEB)
Yoshitake, T.; Hattori, W.; Murakami, S.; Suzuki, S. [NEC Corp., Tokyo (Japan)
1999-11-10
In this report, Ka band microstrip band pass filter was produced experimentally using an YBCO system high temperature superconductivity thin film as examination initial stage high temperature superconductivity a thin film superscription communication element. With it, the following were examined: Evaluation method and frequency characteristics of the filter. Especially, the examination on structure of the package and system of measurement using refrigerating machine becomes important in order to evaluate the filter with the high frequency. (NEDO)
Optical systems fabricated by printing-based assembly
Energy Technology Data Exchange (ETDEWEB)
Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung
2017-03-21
Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.
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.
Filtering multiscale dynamical systems in the presence of model error
Harlim, John
2013-01-01
In this review article, we report two important competing data assimilation schemes that were developed in the past 20 years, discuss the current methods that are operationally used in weather forecasting applications, and point out one major challenge in data assimilation community: "utilize these existing schemes in the presence of model error". The aim of this paper is to provide theoretical guidelines to mitigate model error in practical applications of filtering multiscale dynamical systems with reduced models. This is a prototypical situation in many applications due to limited ability to resolve the smaller scale processes as well as the difficulty to model the interaction across scales. We present simple examples to point out the importance of accounting for model error when the separation of scales are not apparent. These examples also elucidate the necessity of treating model error as a stochastic process in a nontrivial fashion for optimal filtering, in the sense that the mean and covariance estima...
A fault detection and isolation filter for discrete linear systems.
Giovanini, L; Dondo, R
2003-10-01
The problem of fault and/or abrupt disturbances detection and isolation for discrete linear systems is analyzed in this work. A strategy for detecting and isolating faults and/or abrupt disturbances is presented. The strategy is an extension of an already existing result in the continuous time domain to the discrete domain. The resulting detection algorithm is a Kalman filter with a special structure. The filter generates a residuals vector in such a way that each element of this vector is related with one fault or disturbance. Therefore the effects of the other faults, disturbances, and measurement noises in this element are minimized. The necessary stability and convergence conditions are briefly exposed. A numerical example is also presented.
Simulation and fabrication of integrated polystyrene microlens in microfluidic system
Fan, Yiqiang
2013-05-17
This paper presents a simple and quick method to integrate microlens with the microfluidics systems. The polystyrene (PS) based microlens is fabricated with the free surface thermal compression molding methods, a thin PS sheet with the microlens is bonded to a PMMA substrate which contains the laser ablated microchannels. The convex profiler of the microlens will give a magnified images of the microchannels for easier observation. Optical simulation software is being used for the design and simulation of the microlens to have optimal optical performance with the desired focal length. A microfluidic system with the integrated PS microlens is also fabricated for demonstration.
Cai, Longfei; Wang, Yong; Wu, Yunying; Xu, Chunxiu; Zhong, Minghua; Lai, Heyun; Huang, Junsheng
2014-09-21
We developed a novel, low-cost and simple method for the fabrication of microfluidic paper-based analytical devices (μPADs) by silanization of filter cellulose using a paper mask having a specific pattern. The paper mask was penetrated with trimethoxyoctadecylsilane (TMOS) by immersing into TMOS-heptane solution. By heating the filter paper sandwiched between the paper mask and glass slides, TMOS was immobilized onto the filter cellulose via the reaction between cellulose OH and TMOS, while the hydrophilic area was not silanized because it was not in contact with the paper mask penetrated with TMOS. The effects of some factors including TMOS concentration, heating temperature and time on the fabrication of μPADs were studied. This method is free of any expensive equipment and metal masks, and could be performed by untrained personnel. These features are very attractive for the fabrication and applications of μPADs in developing countries or resource-limited settings. A flower-shaped μPAD was fabricated and used to determine glucose in human serum samples. The contents determined by this method agreed well with those determined by a standard method.
Directory of Open Access Journals (Sweden)
S. Sellakumar
2015-06-01
Full Text Available The inverter topology is being used as an active filter to reduce the harmonics in the power system [1]. The traditional voltage source or current source inverters are having the disadvantages of limited output voltage range hence it may not be able to supply enough compensating currents during heavy switching surges, Vulnerable to EMI noise and the devices gets damaged in either open or short circuit conditions and the main switching device of VSI and CSI are not interchangeable. The active filters are the type of DC-AC system with wide range of voltage regulation and integration of energy storages is often required. This cannot be achieved with conventional inverters and hence the impedance source inverters have been suggested. The T source inverters are basically impedance source inverters which can be used as an active filter in the power system. The MATLAB simulation is done and the results are discussed in this paper for both the types. The proposed dampening system is fully characterized by LCL based passive filters [6] and T source inverter based shunt active filter. The disturbances in the supply voltage and load current due to the non linear loads are observed in the simulation. The same is studied after connecting the designed hybrid shunt active filter in the distribution system. The simulation results obtained from the proposed method proves that it gives comparatively better THD value.
Scala, Fabrizio; Clack, Herek L
2008-04-01
Mercury emissions from coal combustion must be reduced, in response to new air quality regulations in the U.S. Although the most mature control technology is adsorption across a dust cake of powdered sorbent in a fabric filter (FF), most particulate control in the U.S. associated with coal combustion takes the form of electrostatic precipitation (ESP). Using recently developed models of mercury adsorption within an ESP and within a growing sorbent bed in a FF, parallel analyses of elemental mercury (Hg(0)) uptake have been conducted. The results show little difference between an ESP and a FF in absolute mercury removal for a low-capacity sorbent, with a high-capacity sorbent achieving better performance in the FF. Comparisons of fractional mercury uptake per-unit-pressure-drop provide a means for incorporating and comparing the impact of the much greater pressure drop of a FF as compared to an ESP. On a per-unit-pressure-drop basis, mercury uptake within an ESP exhibited better performance, particularly for the low-capacity sorbent and high mass loadings of both sorbents.
Tuaprakone, T.; Wongphaet, N.; Wasanapiarnpong, T.
2011-04-01
Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 μm. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 °C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 °C for 1 h showed the highest specific surface area as 174.95 m2/g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.
Optical fiber gas sensing system based on FBG filtering
Wang, Shutao
2008-10-01
An optical fiber gas sensing system based on the law of Beer-Lambert is designed to determine the concentration of gas. This technique relies on the fact that the target gas has a unique, well-defined absorption characteristic within the infrared region of electromagnetic spectrum. The narrow-band filtering characteristic of optical fiber Bragg grating is used to produce the narrow spectrum light signal. An aspheric objective optical fiber collimator is used in the system as an optical fiber gas sensing detector to improve the sensitivity and stability. Experimental results show there is a high measuring sensitivity at 0.01%, and the measuring range goes beyond 5%.
Decentralized control and filtering in interconnected dynamical systems
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
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).
Fabrication of Microfluidic Fiber Chip Detection System
Institute of Scientific and Technical Information of China (English)
Bo Su; Da-fu Cui; Chang-chun Liu; Xing Chen
2006-01-01
The diameter of the excitation beam was decreased greatly by integrating the fiber on the microfluidic chip as light propagation medium. The coupling efficiency of the fiber was improved with optical fiber collimation device coupling beam.The chip was placed in the darkroom to avoid the interference of the external light. The cost of the instrument was decreased with a high brightness blue LED as excitation source; the performance of the system was valuated by the determination of FITC fluorescein with a minimum detectable concentration of 2.2×10-8 mol/L, the Signal-to-Noise Ratio (SNR) S/N=5. The correlation coefficient of the detection system within the range of 1.8 × 10-7 mol/L～ 4 × 10-5mol/L was 0.9972.
A microprocessor based anti-aliasing filter for a PCM system
Morrow, D. C.; Sandlin, D. R.
1984-01-01
Described is the design and evaluation of a microprocessor based digital filter. The filter was made to investigate the feasibility of a digital replacement for the analog pre-sampling filters used in telemetry systems at the NASA Ames-Dryden Flight Research Facility (DFRF). The digital filter will utilize an Intel 2920 Analog Signal Processor (ASP) chip. Testing includes measurements of: (1) the filter frequency response and, (2) the filter signal resolution. The evaluation of the digital filter was made on the basis of circuit size, projected environmental stability and filter resolution. The 2920 based digital filter was found to meet or exceed the pre-sampling filter specifications for limited signal resolution applications.
Design and Modification of Electric Heating Control System of Na-K Alloy Fabrication Loop
Institute of Scientific and Technical Information of China (English)
XIE; Zheng; ZHU; Hao; ZHANG; Ting
2015-01-01
The Na-K alloy fabrication loop has been built since 2003.The loop mainly includes sodium storage tank,potassium storage tank,sodium transportation tank,potassium transportation tank,Na-K alloy fabrication tank,filters,corresponding valves and pipes.It is mainly used for
PWM-Statcom system additionally having active filter function
Energy Technology Data Exchange (ETDEWEB)
Matsui, K.; Kojima, H.; Yamamoto, I.; Hasegawa, M. [Chubu Univ., Kasugai Aichi (Japan); Ando, K. [Nitto Kogyo Corp., Nagakute, Aichi (Japan)
2006-07-01
The harmonic characteristics of static synchronous compensators (Statcom) were discussed with particular reference to the difference between symmetrical and asymmetrical modulation strategies that influence a quality of output waveform. The asymmetrical modulation strategy is the better approach in higher power factor applications such as alternating current (AC) motor drives. It was noted that in cases requiring a passive filter with a very large scale Statcom, a symmetrical modulation strategy is superior. Therefore, in this study, a symmetrical modulation was preferred for a neutral point clamped (NPC) pulse width modulation (PWM) inverter. Due to switching in a limited narrow frequency band, such output harmonics can be eliminated using a simple passive filter and harmonics such as the fifth and the seventh, can be suppressed using the proposed Statcom scheme in which the feedback signals for the fifth and seventh harmonics are injected into the Statcom. Using these feedback signals, the harmonics in the power system were significantly reduced. This result was also confirmed by simulation. It was concluded that, in addition to the proper operation of the Statcom, it is possible to perform an active filtering function . 10 refs., 1 tab., 9 figs.
System of fabricating a flexible electrode array
Energy Technology Data Exchange (ETDEWEB)
Krulevitch, Peter [Pleasanton, CA; Polla, Dennis L [Roseville, MN; Maghribi, Mariam N [Davis, CA; Hamilton, Julie [Tracy, CA; Humayun, Mark S [La Canada, CA; Weiland, James D [Valencia, CA
2012-01-28
An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.
System of fabricating a flexible electrode array
Krulevitch, Peter; Polla, Dennis L.; Maghribi, Mariam N.; Hamilton, Julie; Humayun, Mark S.; Weiland, James D.
2010-10-12
An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.
System of fabricating a flexible electrode array
Energy Technology Data Exchange (ETDEWEB)
Krulevitch, Peter (Pleasanton, CA); Polla, Dennis L. (Roseville, MN); Maghribi, Mariam N. (Davis, CA); Hamilton, Julie (Tracy, CA); Humayun, Mark S. (La Canada, CA); Weiland, James D. (Valencia, CA)
2010-10-12
An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.
System of fabricating a flexible electrode array
Energy Technology Data Exchange (ETDEWEB)
Krulevitch, Peter (Pleasanton, CA); Polla, Dennis L. (Roseville, MN); Maghribi, Mariam N. (Davis, CA); Hamilton, Julie (Tracy, CA); Humayun, Mark S. (La Canada, CA); Weiland, James D. (Valencia, CA)
2012-01-28
An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.
Energy Technology Data Exchange (ETDEWEB)
Leahy, D.F.; Klotz, P.J.; Springston, S.R.; Daum, P.H.
1995-04-01
A filter pack system for sampling trace constituents in the atmosphere from aircraft and ground-based measurement platforms has been developed. The system simultaneously and quantitatively collects atmospheric aerosol, nitric acid, and sulfur dioxide using three sequential filter stages. The quartz aerosol filter is routinely analyzed for sulfate, nitrate, ammonium, and hydrogen ions, and specifically for sulfuric acid. The sodium chloride filter is analyzed for nitrate ion (from collected nitric acid), and the carbonate-glycerine filter for sulfate ion (from collected sulfur dioxide). Details of the procedures used for filter preparation, sampling, extraction and analysis are given.
The Simulating of the Woven Fabric Visual System
Institute of Scientific and Technical Information of China (English)
DENG Zhongmin; LU Hongmei; ZHU Lili
2006-01-01
With Visual C++6.0 as the language, following the traditional waterfall model and the software engineering theory, utilizing the technique of the dialog box, picture synthesis in VC, the writers present the developing of the woven fabric CAD system under the environment of Windows98. The system includes weave designing, yarn simulating, color matching, handling hand sample fabric and the testing effect.The basic methods and effect evaluation have been discussed and developed for the weave designing, yarn appearance simulating and fabric color matching, as well as handling hand sample states the image processing, such as DIB(Device-independent bitmap);meanwhile, the developed system has been tested and run in actual design and textile mill trials. The operated results show that the system runs steadily, efficiently and smart, it can be widely used in yarn and fabric design by using with the merits of convenience, celerity and nicety in shortening the developing periods of product; additionally, it provides in fact a new approach to technical design for textile mills.
Unbalance vibration suppression for AMBs system using adaptive notch filter
Chen, Qi; Liu, Gang; Han, Bangcheng
2017-09-01
The unbalance of rotor levitated by active magnetic bearings (AMBs) will cause synchronous vibration which greatly degrade the performance at high speeds in the rotating machinery. To suppress the unbalance vibration without angular velocity information, a novel modified adaptive notch filter (ANF) with phase shift in the AMBs system is presented in this study. Firstly, a 4-degree-of-freedom (DOF) radial unbalanced AMB rotor system is described and analyzed, and the solution of rotor vibration displacement is compared with the experimental data to verify the preciseness of the dynamic model. Then the principle and structure of the proposed notch filter used for the frequency estimation and online identification of synchronous component are presented. As well, the convergence property of the algorithm is investigated. In addition, the stability analysis of the closed-loop AMB system with the proposed ANF is conducted. Simulation and experiments on an AMB driveline system demonstrate the effectiveness and the adaptive characteristics of the proposed ANF on the elimination of synchronous controlled current in a widely operating speed range.
Electrically heated particulate filter regeneration methods and systems for hybrid vehicles
Energy Technology Data Exchange (ETDEWEB)
Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI)
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.
A Novel Method of Edge Filter Linear Demodulation Using Long Period Grating in Fiber Sensor System
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
A novel method of linear demodulation based on edge filter is presented. An experimental system is built up in which LPG is used as the edge filter. We achieve linear demodulation with a bandwidth of 5nm.
Plugin-docking system for autonomous charging using particle filter
Koyasu, Hiroshi; Wada, Masayoshi
2017-03-01
Autonomous charging of the robot battery is one of the key functions for the sake of expanding working areas of the robots. To realize it, most of existing systems use custom docking stations or artificial markers. By the other words, they can only charge on a few specific outlets. If the limit can be removed, working areas of the robots significantly expands. In this paper, we describe a plugin-docking system for the autonomous charging, which does not require any custom docking stations or artificial markers. A single camera is used for recognizing the 3D position of an outlet socket. A particle filter-based image tracking algorithm which is robust to the illumination change is applied. The algorithm is implemented on a robot with an omnidirectional moving system. The experimental results show the effectiveness of our system.
MSK modulated filter bank multicarrier system with mitigated subcarrier interference
Liu, Bo; Zhang, Lijia; Xin, Xiangjun
2017-01-01
This paper proposes a novel minimum shift keying (MSK) modulated filter bank multi-carrier (FBMC) system. It can improve the signal performance by suppressing the interference among subcarriers. The spectral efficiency can be improved due to the absence of cyclic prefix in the system. In the experiment, a 15.67 Gb/s MSK-FBMC signal is transmitted over 80 km single mode fiber successfully. The performance of FBMC based multicarrier system outperforms that of fast Fourier transforms (FFT) based multicarrier system by 0.9 dB. Compared with QPSK mapping, 1 dB optical signal to noise ratio (OSNR) improvement is obtained with MSK mapping under a normalized residual frequency offset of 0.2.
Damping strapdown inertial navigation system based on a Kalman filter
Zhao, Lin; Li, Jiushun; Cheng, Jianhua; Hao, Yong
2016-11-01
A damping strapdown inertial navigation system (DSINS) can effectively suppress oscillation errors of strapdown inertial navigation systems (SINSs) and improve the navigation accuracy of SINSs. Aiming at overcoming the disadvantages of traditional damping methods, a DSINS, based on a Kalman filter (KF), is proposed in this paper. Using the measurement data of accelerometers and calculated navigation parameters during the navigation process, the expression of the observation equation is derived. The calculation process of the observation in both the internal damping state and the external damping state is presented. Finally, system oscillation errors are compensated by a KF. Simulation and test results show that, compared with traditional damping methods, the proposed method can reduce system overshoot errors and shorten the convergence time of oscillation errors effectively.
Sampling and Filtering in Photovoltaic System Performance Monitoring
Energy Technology Data Exchange (ETDEWEB)
Driesse, Anton [PV Performance Labs, Freiburg (Germany); Stein, Joshua S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photovoltaic and Distributed Systems Integration; Riley, Daniel M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photovoltaic and Distributed Systems Integration; Carmignani, Craig K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photovoltaic and Distributed Systems Integration
2014-10-01
The performance of photovoltaic systems must be monitored accurately to ensure profitable long-term operation. The most important signals to be measured—irradiance and temperature, as well as power, current and voltage on both DC and AC sides of the system—contain rapid fluctuations that are not observable by typical monitoring systems. Nevertheless these fluctuations can affect the accuracy of the data that are stored. This report closely examines the main signals in one operating PV system, which were recorded at 2000 samples per second. It analyzes the characteristics and causes of the rapid fluctuations that are found, such as line-frequency harmonics, perturbations from anti-islanding detection, MPPT searching action and others. The operation of PV monitoring systems is then simulated using a wide range of sampling intervals, archive intervals and filtering options to assess how these factors influence data accuracy. Finally several potential sources of error are discussed with real-world examples.
Collaborative Filtering Algorithms Based on Kendall Correlation in Recommender Systems
Institute of Scientific and Technical Information of China (English)
YAO Yu; ZHU Shanfeng; CHEN Xinmeng
2006-01-01
In this work, Kendall correlation based collaborative filtering algorithms for the recommender systems are proposed. The Kendall correlation method is used to measure the correlation amongst users by means of considering the relative order of the users' ratings. Kendall based algorithm is based upon a more general model and thus could be more widely applied in e-commerce. Another discovery of this work is that the consideration of only positive correlated neighbors in prediction, in both Pearson and Kendall algorithms, achieves higher accuracy than the consideration of all neighbors, with only a small loss of coverage.
Transversal filter MMIC design for multi-Gbit/s optical CDMA systems.
Aguilar Torrentera, J.
2004-01-01
In this thesis, the approach of the distributed-amplifier based transversal filter for multi-Gbit/s Optical CDMA systems is addressed. Of particular interest is the research into circuits that enable handling high rate sequences for high-speed system applications. Different distributed transversal filter structures were considered, in particular those that allow extending the range of filtering functions by including positive and negative tap gain weight control. A novel transversal filter to...
Robust passive filtering for continuous-time polytopic uncertain time-delay systems
Institute of Scientific and Technical Information of China (English)
LU Ling-ling; DUAN Guang-ren; WU Ai-guo
2008-01-01
To obtain a stable and proper linear filter to make the filtering error system robustly and strictly passive,the problem of full-order robust passive filtering for continuous-time polytopie uncertain time-delay systems was investigated.A criterion for the passivity of time-delay systems was firstly provided in terms of linear matrix inequalities(LMI).Then an LMI sufficient condition for the existence of a robust filter was established and a design procedure was proposed for this type of systems.A numerical example demonstrated the feasibility of the filtering design procedure.
Robust dissipative filtering for continuous-time polytopic uncertain neutral systems
Institute of Scientific and Technical Information of China (English)
Duan Guangren; L(u) Lingling; Wu Aiguo
2009-01-01
This article is concerned with the problem of robust dissipative filtering for continuous-time polytopic uncertain neutral systems. The main purpose is to obtain a stable and proper linear filter such that the filtering error system is strictly dissipative. A new criterion for the dissipativity of neutral systems is first provided in terms of linear matrix inequalities (LMI). Then, an LMI sufficient condition for the existence of a robust filter is established and a design procedure is proposed for this type of systems. Two numerical examples are given. One illustrates the less conservativeness of the proposed criterion; the other demonstrates the validity of the filtering design procedure.
Fabric Defect Detection Algorithm Based on Log-Gabor Filter Bank%基于Log-Gabor滤波器组的织物疵点检测算法
Institute of Scientific and Technical Information of China (English)
崔月平; 韩润萍
2011-01-01
In this paper, a scheme using Log-Gabor filter bank for fabric defect detection was proposed. First, a method of constructing Log-Gabor filter bank was presented. Then, fabric defect image was processed using this filter bank, and filtered images were obtained. These images were fused in order to reconstruct the defect binary image that segmented the defect from the texture background. Experiment results had confirmed the effectiveness of this scheme.%利用Log-Gabor滤波器组实现了对织物图像的疵点检测首先给出了构建L.g-Gabor滤波器组的方法,然后利用滤波器组对织物图像进行滤波处理,并对滤波后的图像进行分割和融合,最后将疵点从织物图像的背景纹理中分割出来实验结果证明该方法能够有效地检测出织物疵点.
Ye, Sen; Cao, Qiang; Wang, Qingsong; Wang, Tianyuan; Peng, Qing
2016-11-01
It has been a long standing challenge to efficiently separate oil and water since prehistoric times, and now it has become even more desirable in oily wastewater purification and oil spill cleanup. Here we introduce a super oil-water separation filter with superhydrophilicity and underwater superoleophobicity, fabricated using femtosecond laser micro-hole drilling of a titanium foil. Such a simply-made filter, without any modification, can achieve a separation efficiency exceeding 99% in eight typical oil-water mixtures. It remains highly efficient after 40 cycles of recycling and after suffering erosion by corrosive media. Furthermore, the used filter, polluted with oil, could be recovered by ultraviolet illumination. The flux of filtered water is tunable by simply selecting the aperture of the microhole or the spacing between adjacent microholes. Such advanced functionality is due to roughness and the TiO2 layers on the ablated surface during fabrication. With superhydrophilic and superoleophobic surfaces, this oil-water filer is also suitable for applications in anti-fouling, anti-smudge, anti-fog, and self-cleaning.
Efficient, Narrow-Pass-Band Optical Filters
Sandford, Stephen P.
1996-01-01
Optical filters with both narrow pass bands and high efficiencies fabricated to design specifications. Offer tremendous improvements in performance for number of optical (including infrared) systems. In fiber-optic and free-space communication systems, precise frequency discrimination afforded by narrow pass bands of filters provide higher channel capacities. In active and passive remote sensors like lidar and gas-filter-correlation radiometers, increased efficiencies afforded by filters enhance detection of small signals against large background noise. In addition, sizes, weights, and power requirements of many optical and infrared systems reduced by taking advantage of gains in signal-to-noise ratios delivered by filters.
Robust H∞ filtering for discrete-time impulsive systems with uncertainty
Institute of Scientific and Technical Information of China (English)
Sheng-tao PAN; Ji-tao SUN
2009-01-01
This paper investigates robust filter design for linear discrete-time impulsive systems with uncertainty under H∞ performance. First, an impulsive linear filter and a robust H∞ filtering problem are introduced for a discrete-time impulsive systems. Then,a sufficient condition of asymptotical stability and H∞ performance for the filtering error systems are provided by the discrete-time Lyapunov function method. The filter gains can be obtained by solving a set of linear matrix inequalities (LMIs). Finally, a numerical example is presented to show effectiveness of the obtained result.
Structure and fabrication details of an integrated modularized microfluidic system
Directory of Open Access Journals (Sweden)
Qingchang Tian
2015-12-01
Full Text Available This article contains schemes, original experimental data and figures for an integrated modularized microfluidic system described in “An integrated microfluidic system for bovine DNA purification and digital PCR detection [1]”. In this data article, we described the structure and fabrication of the integrated modularized microfluidic system. This microfluidic system was applied to isolate DNA from ovine tissue lysate and detect the bovine DNA with digital PCR (dPCR. The DNA extraction efficiency of the microdevice was compared with the efficiency of benchtop protocol.
Ensemble Kalman filters for dynamical systems with unresolved turbulence
Energy Technology Data Exchange (ETDEWEB)
Grooms, Ian, E-mail: grooms@cims.nyu.edu [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Lee, Yoonsang [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Majda, Andrew J. [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Center for Prototype Climate Modelling, NYU Abu Dhabi, Abu Dhabi (United Arab Emirates)
2014-09-15
Ensemble Kalman filters are developed for turbulent dynamical systems where the forecast model does not resolve all the active scales of motion. Coarse-resolution models are intended to predict the large-scale part of the true dynamics, but observations invariably include contributions from both the resolved large scales and the unresolved small scales. The error due to the contribution of unresolved scales to the observations, called ‘representation’ or ‘representativeness’ error, is often included as part of the observation error, in addition to the raw measurement error, when estimating the large-scale part of the system. It is here shown how stochastic superparameterization (a multiscale method for subgridscale parameterization) can be used to provide estimates of the statistics of the unresolved scales. In addition, a new framework is developed wherein small-scale statistics can be used to estimate both the resolved and unresolved components of the solution. The one-dimensional test problem from dispersive wave turbulence used here is computationally tractable yet is particularly difficult for filtering because of the non-Gaussian extreme event statistics and substantial small scale turbulence: a shallow energy spectrum proportional to k{sup −5/6} (where k is the wavenumber) results in two-thirds of the climatological variance being carried by the unresolved small scales. Because the unresolved scales contain so much energy, filters that ignore the representation error fail utterly to provide meaningful estimates of the system state. Inclusion of a time-independent climatological estimate of the representation error in a standard framework leads to inaccurate estimates of the large-scale part of the signal; accurate estimates of the large scales are only achieved by using stochastic superparameterization to provide evolving, large-scale dependent predictions of the small-scale statistics. Again, because the unresolved scales contain so much energy
WE-F-16A-02: Design, Fabrication, and Validation of a 3D-Printed Proton Filter for Range Spreading
Energy Technology Data Exchange (ETDEWEB)
Remmes, N; Courneyea, L; Corner, S; Beltran, C; Kemp, B; Kruse, J; Herman, M [Mayo Clinic, Rochester, MN (United States); Stoker, J [MD Anderson Cancer Center, Houston, TX (United States)
2014-06-15
Purpose: To design, fabricate and test a 3D-printed filter for proton range spreading in scanned proton beams. The narrow Bragg peak in lower-energy synchrotron-based scanned proton beams can result in longer treatment times for shallow targets due to energy switching time and plan quality degradation due to minimum monitor unit limitations. A filter with variable thicknesses patterned on the same scale as the beam's lateral spot size will widen the Bragg peak. Methods: The filter consists of pyramids dimensioned to have a Gaussian distribution in thickness. The pyramids are 2.5mm wide at the base, 0.6 mm wide at the peak, 5mm tall, and are repeated in a 2.5mm pseudo-hexagonal lattice. Monte Carlo simulations of the filter in a proton beam were run using TOPAS to assess the change in depth profiles and lateral beam profiles. The prototypes were constrained to a 2.5cm diameter disk to allow for micro-CT imaging of promising prototypes. Three different 3D printers were tested. Depth-doses with and without the prototype filter were then measured in a ~70MeV proton beam using a multilayer ion chamber. Results: The simulation results were consistent with design expectations. Prototypes printed on one printer were clearly unacceptable on visual inspection. Prototypes on a second printer looked acceptable, but the micro-CT image showed unacceptable voids within the pyramids. Prototypes from the third printer appeared acceptable visually and on micro-CT imaging. Depth dose scans using the prototype from the third printer were consistent with simulation results. Bragg peak width increased by about 3x. Conclusions: A prototype 3D printer pyramid filter for range spreading was successfully designed, fabricated and tested. The filter has greater design flexibility and lower prototyping and production costs compared to traditional ridge filters. Printer and material selection played a large role in the successful development of the filter.
Insertion Loss Estimation of EMI Filters in Unmatched Input/Output Impedance System
Directory of Open Access Journals (Sweden)
J. Drinovsky
2011-04-01
Full Text Available One of the problems in the design of powerline EMI filters is the uncertainty and ambiguity of their source/load impedances which results in breach of expected filter parameters in a real installation. The paper presents a simple technique for prediction of insertion loss limit values of EMI filters working in arbitrary unmatched mains line impedance systems.
Decimated Filters for Acquisition System of Signs Electroencephalography
Directory of Open Access Journals (Sweden)
Cyndi González Alfonso
2013-06-01
Full Text Available In digital electroencephalography, a sampling frequency of 200 samples per second (s.p.s is theminimum used. However, the present trend of these systems for recording brain electrical activity(EEG, in the area of research is the use of higher sampling at 1000 s.p.s, in order to reproduce shortevents (intracortical records epileptic activity as well as to faithfully reproduce some kinds of artifactsto subtract digital post-processing means. Because this results in greater use of memory for thestorage of the data, in long records, as sleep studies, it is convenient to work with the minimumsampling frequency recommended by the IFCN (200m.ps being necessary to lower it by a process ofdecimation. This paper presents the study and analysis of criteria for the design optimization ofdecimates stages for electroencephalographic signal implemented by a FIR digital filter, with a versatileapplication to EEG recording systems in development by the Neuroscience Center of Cuba (CNEURO
Printing technologies in fabrication of drug delivery systems
DEFF Research Database (Denmark)
Kolakovic, Ruzica; Viitala, Tapani; Ihalainen, Petri
2013-01-01
INTRODUCTION: There has been increased activity in the field recently regarding the development and research on various printing techniques in fabrication of dosage forms and drug delivery systems. These technologies may offer benefits and flexibility in manufacturing, potentially paving the way....... Challenges on different levels exist and include: i) technological development of printers and production lines; ii) printable formulations and carrier substrates; iii) quality control and characterization; and iv) regulatory perspectives....
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.
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.
Application of H∞ filtering in the initial alignment of strapdown inertial navigation system
Institute of Scientific and Technical Information of China (English)
YU Fei; SUN Feng
2005-01-01
In this paper , the principle of H∞ filtering is discussed and H∞ filter is constructed, which is used in the initial alignment of the strapdown inertial navigation systems(SINS). The error model of SINS is derived. By utilizing constructed H∞ filter, the filtering calculation to that system has been conducted. The simulation results of the misalignment angle are given under the condition of unknown noises. The results show that the process of alignment with H∞ filter is much faster and with excellent robustness.
Ghaderi, Mohammadamir; Wolffenbuttel, Reinoud F.
2016-10-01
MEMS-based airgap optical filters are composed of quarter-wave thick high-index dielectric membranes that are separated by airgaps. The main challenge in the fabrication of these filters is the intertwined optical and mechanical requirements. The thickness of the layers decreases with design wavelength, which makes the optical performance in the UV more susceptible to fabrication tolerances, such as thickness and composition of the deposited layers, while the ability to sustain a certain level of residual stress by the structural strength becomes more critical. Silicon-nitride has a comparatively high Young's modulus and good optical properties, which makes it a suitable candidate as the membrane material. However, both the mechanical and optical properties in a silicon-nitride film strongly depend on the specifics of the deposition process. A design trade-off is required between the mechanical strength and the index of refraction, by tuning the silicon content in the silicon-nitride film. However, also the benefit of a high index of refraction in a silicon-rich film should be weighed against the increased UV optical absorption. This work presents the design, fabrication, and preliminary characterization of one and three quarter-wave thick silicon-nitride membranes with a one-quarter airgap and designed to give a spectral reflectance at 400 nm. The PECVD silicon-nitride layers were initially characterized, and the data was used for the optical and mechanical design of the airgap filters. A CMOS compatible process based on polysilicon sacrificial layers was used for the fabrication of the membranes. Optical characterization results are presented.
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.
Global Systems for Mobile Position Tracking Using Kalman and Lainiotis Filters
Directory of Open Access Journals (Sweden)
Nicholas Assimakis
2014-01-01
Full Text Available We present two time invariant models for Global Systems for Mobile (GSM position tracking, which describe the movement in x-axis and y-axis simultaneously or separately. We present the time invariant filters as well as the steady state filters: the classical Kalman filter and Lainiotis Filter and the Join Kalman Lainiotis Filter, which consists of the parallel usage of the two classical filters. Various implementations are proposed and compared with respect to their behavior and to their computational burden: all time invariant and steady state filters have the same behavior using both proposed models but have different computational burden. Finally, we propose a Finite Impulse Response (FIR implementation of the Steady State Kalman, and Lainiotis filters, which does not require previous estimations but requires a well-defined set of previous measurements.
Method and system of filtering and recommending documents
Energy Technology Data Exchange (ETDEWEB)
Patton, Robert M.; Potok, Thomas E.
2016-02-09
Disclosed is a method and system for discovering documents using a computer and providing a small set of the most relevant documents to the attention of a human observer. Using the method, the computer obtains a seed document from the user and generates a seed document vector using term frequency-inverse corpus frequency weighting. A keyword index for a plurality of source documents can be compared with the weighted terms of the seed document vector. The comparison is then filtered to reduce the number of documents, which define an initial subset of the source documents. Initial subset vectors are generated and compared to the seed document vector to obtain a similarity value for each comparison. Based on the similarity value, the method then recommends one or more of the source documents.
Panniello, Umberto; Gorgoglione, Michele; Palmisano, Cosimo
Recent literature predicts that including context in a recommender system may improve its performance. The context-based recommendation approaches are classified as pre-filtering, post-filtering and contextual modeling. Little research has been done on studying whether including context in a recommender system improves the recommendation performance and no research has compared yet the different approaches to contextual RS. The research contribution of this work lies in studying the effect of the context on the recommendation performance and comparing a pre-filtering approach to a post-filtering using a collaborative filtering recommender system.
B-Plant D-Filter detector system qualification test report
Energy Technology Data Exchange (ETDEWEB)
Ritter, G.A., Westinghouse Hanford
1996-08-23
This report summarizes the results of qualification testing of the B Plant D-Filter Detector System. The purpose of this test was to verify that the system meets the performance requirements and that the unit is ready for field deployment. Testing was performed in the test pit in the 306E Facility. This detector system will be deployed in the B Plant D-Filter to measure beta/gamma dose rates from the filter bank.
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.
Holographic interference filters
Diehl, Damon W.
Holographic mirrors have wavelength-selection properties and thus qualify as a class of interference filters. Two theoretical methods for analyzing such structures are developed. The first method uses Hill's matrix method to yield closed-forms solutions in terms of the Floquet-Bloch waves within a periodic structure. A process is developed for implementing this solution method on a computer, using sparse-matrix memory allocation, numerical root-finding algorithms, and inverse-iteration techniques. It is demonstrated that Hill's matrix method is valid for the analysis of finite and multi-periodic problems. The second method of theoretical analysis is a transfer-matrix technique, which is herein termed thin-film decomposition. It is shown that the two methods of solution yield results that differ by, at worst, a fraction of a percent. Using both calculation techniques, a number of example problems are explored. Of key importance is the construction of a set of curves that are useful for the design and characterization of holographic interference filters. In addition to the theoretical development, methods are presented for the fabrication of holographic interference filters using DuPont HRF-800X001 photopolymer. Central to the exposure system is a frequency-stabilized, tunable dye laser. The types of filters fabricated include single-tone reflection filters, two types of multitone reflection filters, and reflection filters for infrared wavelengths. These filters feature index profiles that are not easily attainable through other fabrication methods. As a supplement to the body of the dissertation, the computer algorithms developed to implement Hill's matrix method and thin-film decomposition are also included as an appendix. Further appendices provide more information on Floquet's theorem and Hill's matrix method. A final appendix presents a design for an infrared laser spectrophotometer.
Design of Special Impacting Filter for Multicarrier ABPSK System
Directory of Open Access Journals (Sweden)
Zhimin Chen
2013-01-01
Full Text Available A rather intuitive technique known as pole-zero placement is introduced to illustrate the frequency response of the special impacting filters (SIFs with a pair of conjugate zero-poles and deduce the equation of the pole radii. Based on that, the paper proposes an iterative scheme to derive the parameters of the cascade notch filter. The cost function is determined by the cascading notch filter’s influence on impacting filters, converting the cost function’s least square problem to a filter parameters’ standard quadratic programming problem. Finally, a cascading notch SIF (CNSIF designed to demodulate the ABPSK signals is realized.
Filtering and Estimation of Vehicular Dead Reckoning System Based on Hopfield Neural Network
Institute of Scientific and Technical Information of China (English)
毕军; 付梦印; 张启鸿
2003-01-01
The algorithm of Hopfield neural network filtering and estimation is studied. The model of vehicular dead reckoning system fitting for the algorithm is constructed, and the design scheme of system filtering and estimation based on Hopfield network is proposed. Compared with Kalman filter, the algorithm does not require very precise system model and the prior knowledge of noise statistics and does not diverge easily. The simulation results show that the vehicular dead reckoning system based on Hopfield network filtering and estimation has the good position precision, and needn't require the inertial sensors with high precision. Therefore, the algorithm has the good practicability.
Ghaderi, Mohammadamir; de Graaf, Ger; Wolffenbuttel, Reinoud F.
2016-04-01
CMOS-compatible fabrication of thin dielectric membranes for the ultraviolet and visible spectrum is presented for use in airgap/SiO2-based interference filter design. A typical optical design consists of multiple membranes of 50-100 nm thickness. Maintaining flatness over a large area, as required by the optical application, is challenging. In such a free-standing membrane, the residual stress is the main force acting on the structure. Although an overall tensile residual stress can effectively stretch the membrane, too much stress would exceed the yield strength of the material and results in fracturing. Furthermore, the presence of a residual stress gradient causes the membrane to deform. In this work, the effect of a stress profile in the thin film has is investigated. Although PECVD SiO2 layers with an average tensile stress level of 178 MPa are used for the fabrication of the membranes, the presence of a stress gradient of about 0:67 MPa=nm results in a deformation in the membrane. A simple straining method is applied to reduce flatness. The preliminary results and discusses the challenges in the fabrication of stacked membranes for optical filters are presented.
Inverter Output Filter Effect on PWM Motor Drives of a Flywheel Energy Storage System
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.
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.
Mixed H2/H∞ filtering for a class of high-speed sampling uncertain systems
Institute of Scientific and Technical Information of China (English)
ZHANG Rui; YAO Yu; MA KeMao; CHEN SongLin
2008-01-01
The problem of mixed H2/H∞ filtering for polytopic Delta operator systems is inves-tigated. The aim is to design a linear asymptotically stable filter which guarantees that the filtering error system has different performances in different filtering channels. Based on a parameter-dependent Lyapunov function, a new mixed H2/H∞ performance criterion is presented. Upon this performance criterion, a sufficient condition for the full-order mixed H2/H∞ filter is derived in terms of linear matrix inequalities. The filter can be obtained from the solution of a convex optimization problem. The proposed filter design procedure is less conservative than the strat-egy based on the quadratic stability notion. A numerical example is given to illus-trate the feasibility of the proposed approach.
Optical thin-film reflection filters based on the theory of photonic crystals.
Sun, Xuezheng; Shen, Weidong; Gai, Xin; Gu, Peifu; Liu, Xu; Zhang, Yueguang
2008-05-01
Based on the theory of photonic crystals and the framework of a single-channel reflection filter that we presented before, structures of reflection filters with multiple channels are proposed. These structures can overcome some drawbacks of conventional multichannel transmission filters and are much easier to fabricate. We have practically fabricated the reflection filters with two and three channels, and the tested results show approximate agreement with theoretical simulation. Moreover, the superprism effect is also simulated in the single-channel reflection filter, the superiorities to transmission filters are discussed, and these analyses may shed some light on new applications of reflection filters in optical communication and other systems.
Design and Fabrication of Wide Tunable Range MEMS Integrated Filters%宽范围可调MEMS集成滤波器的设计与制作
Institute of Scientific and Technical Information of China (English)
杨志; 杨拥军; 李倩; 胡小东
2011-01-01
基于MEMS平面螺旋电感和MEMS可调平行板电容设计并制作了一种宽可调范围的集成可调带通滤波器.理论分析并计算了可调滤波器电感和可调电容的取值范围,利用HFSS设计得到各元件结构参数,并使用Ansoft Designer 分析软件对可调滤波器电路进行了模拟仿真.设计得到的可调滤波器中心频率调节范围为400～700 MHz,可调率达75%,实现了宽范围可调,3 dB相对带宽范围为5%～10%,插入损耗小于5 dB,芯片尺寸为20 mm×6 mm×0.4 mm.给出了一套基于MEMS平面工艺的MEMS集成可调滤波器的制作流程,实现了MEMS集成可调滤波器的工艺制作及测试.测试结果表明,获得的可调滤波器实现了通带频率宽范围可调.%A wide tunable range integrated tunable band-pass filter was designed and fabricated based on the MEMS planar spiral inductors and MEMS tunable parallel plate variable capacitors. The inductance and capacitance of the tunable filter were analyzed and calculated theoretically, the structure parameters were designed by HFSS, and the circuit of the tunable filter was simulated by Ansoft Designer software. The wide tunable range filter was designed with a tunable center frequency of 400 - 700 MHz, the tunable ratio of 75％, a 3 dB fractional bandwidth range of 5％ - 10％, the in-band loss of 5 dB, and the chip size of 20 mm×6 mm×0.4 mm. A process scheme of the MEMS integrated tunable filter was presented based on the MEMS surface micromachining technology. The fabrication and measurement of the MEMS integrated tunable filter were realized. The measurement results show that the obtained filter has a wide tunable range.
Link performance model for filter bank based multicarrier systems
Petrov, Dmitry; Oborina, Alexandra; Giupponi, Lorenza; Stitz, Tobias Hidalgo
2014-12-01
This paper presents a complete link level abstraction model for link quality estimation on the system level of filter bank multicarrier (FBMC)-based networks. The application of mean mutual information per coded bit (MMIB) approach is validated for the FBMC systems. The considered quality measure of the resource element for the FBMC transmission is the received signal-to-noise-plus-distortion ratio (SNDR). Simulation results of the proposed link abstraction model show that the proposed approach is capable of estimating the block error rate (BLER) accurately, even when the signal is propagated through the channels with deep and frequent fades, as it is the case for the 3GPP Hilly Terrain (3GPP-HT) and Enhanced Typical Urban (ETU) models. The FBMC-related results of link level simulations are compared with cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) analogs. Simulation results are also validated through the comparison to reference publicly available results. Finally, the steps of link level abstraction algorithm for FBMC are formulated and its application for system level simulation of a professional mobile radio (PMR) network is discussed.
Minimum Error Entropy Filter for Fault Detection of Networked Control Systems
Guolian Hou; Mifeng Ren; Lilong Du; Jianhua Zhang
2012-01-01
In this paper, fault detection of networked control systems with random delays, packet dropout and noises is studied. The filter is designed using a minimum error entropy criterion. The residual generated by the filter is then evaluated to detect faults in networked control systems. An illustrative networked control system is used to verify the effectiveness of the proposed approach.
Minimum Error Entropy Filter for Fault Detection of Networked Control Systems
Directory of Open Access Journals (Sweden)
Guolian Hou
2012-03-01
Full Text Available In this paper, fault detection of networked control systems with random delays, packet dropout and noises is studied. The filter is designed using a minimum error entropy criterion. The residual generated by the filter is then evaluated to detect faults in networked control systems. An illustrative networked control system is used to verify the effectiveness of the proposed approach.
Energy Technology Data Exchange (ETDEWEB)
Park, Han Beom; Kim, Hyun Jin; Lee, Ju Hyuk; Ha, Jun Mok; Cho, Sung Oh [KAIST, Daejeon (Korea, Republic of)
2016-05-15
A miniature X-ray tube is a small X-ray generation device generally with a diameter of less than 10 mm. Because of the feasible installation in a spatially constrained area and the possibility of electrical on/off control, miniature X-ray tubes can be widely used for nondestructive X-ray radiography, hand held X-ray spectrometers, electric brachytherapy, and interstitial or intracavitary radiation therapy or imaging with the substitution of radioactive isotopes. Miniature X-ray tubes have been developed mostly using thermionic electron sources or secondary X-ray emission. The X-ray tube show excellent field emission properties and good X-ray spectrum. Also, the flattening filter was made to irradiate uniformly. The X-ray dose radial uniformities between installed flattening filter and non-installed flattening filter were measured. When flattening filter is equipped, X-ray uniformity was improved from higher than 20% to lower than 10%. As a result, the fabricated applicator system of the miniature X-ray tube using optimized flattening filter exhibited fairly excellent properties.
Defending of IP Spoofing by Ingress Filter in Extended-Inter Domain Packet Key Marking System
Directory of Open Access Journals (Sweden)
G.Velmayil
2013-04-01
Full Text Available The significance of the DDoS problem and the increased occurrence and strength of attacks has led to the dawn of numerous prevention mechanisms. IP spoofing is most frequently used in denial-of-service attacks. In such attacks, the goal is to flood the victim with overwhelming amounts of traffic, and the attacker does not care about receiving responses to the attack packets. IP spoofing is one of the basic weaknesses in the Internet Protocol to launch the DDOS attack. Each prevention mechanism has some unique advantages and disadvantages over the others. The existing methods become ineffective due to a large number of filters required and they lack in information about where to place the filter. We propose Ingress filter in Extended Inter Domain Packet Key marking system .This paper comprises of two functional blocks namely, Key marking system and filtering blocks. In the marking block, each source is labeled with a key. The key is changed continuously for a certain period of time to provide secured system and is validated at border routers. In the filtering block, spoofed packets are filtered at the border router using Ingress filter to filter beyond periphery routers. The filter placement algorithm clearly put forwards the conditions under which the filter can operate accurately. The accuracy of the proposed systems is validated using Network Simulator (NS-2.
Robust output feedback H-infinity control and filtering for uncertain linear systems
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.
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.
A Series-LC-Filtered Active Damper for AC Power Electronics Based Power Systems
DEFF Research Database (Denmark)
Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang
2015-01-01
This paper proposes an active damper with a series LC-filter for suppressing resonances in an ac power electronics based power system. The added filter capacitor helps to lower the voltage stress of the converter to be used for implementing the damper. Unlike active filters for the compensation...... is built, where the damper is integrated into a grid-connected converter. The results obtained from the experiments demonstrate the stability enhancement of ac power electronics based power systems by the active damper....
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.
Operating Experiences with an Advanced Fabric Energy Storage System
Directory of Open Access Journals (Sweden)
R.J Fuller
2012-11-01
Full Text Available Despite their proven track record in the cold climate countries of northern Europe, there are no reports in the research literature of experiences using advanced fabric energy storage (FES systems in countries where cooling rather than heating is the main priority. This paper reports some of the experiences with the first known advanced FES system in Australia made over the first full calendar year of operation. It is located in a three-storey building on a university campus in Victoria and has been in operation since mid-2002. Temperature, energy use and operational mode data were recorded during 2003. Airflow measurements through the FES system have been made in five areas of the building. On-going operating problems still exist with the system and this has prevented a conclusive evaluation of its suitability for the southern Australian climate.
Tritium Systems Test Assembly: design for major device fabrication review
Energy Technology Data Exchange (ETDEWEB)
Anderson, J.L.; Sherman, R.H.
1977-06-01
This document has been prepared for the Major Device Fabrication Review for the Tritium Systems Test Assembly (TSTA). The TSTA is dedicated to the development, demonstration, and interfacing of technologies related to the deuterium-tritium fuel cycle for fusion reactor systems. The principal objectives for TSTA are: (a) demonstrate the fuel cycle for fusion reactor systems; (b) develop test and qualify equipment for tritium service in the fusion program; (c) develop and test environmental and personnel protective systems; (d) evaluate long-term reliability of components; (e) demonstrate long-term safe handling of tritium with no major releases or incidents; and (f) investigate and evaluate the response of the fuel cycle and environmental packages to normal, off-normal, and emergency situations. This document presents the current status of a conceptual design and cost estimate for TSTA. The total cost to design, construct, and operate TSTA through FY-1981 is estimated to be approximately $12.2 M.
Digital filtering using the multidimensional logarithmic number system
Dimitrov, Vassil S.; Jullien, Graham A.; Walus, Konrad
2002-12-01
We introduce the use of multidimensional logarithmic number system (MDLNS) as a generalization of the classical 1-D logarithmic number system (LNS) and analyze its use in DSP applications. The major drawback of the LNS is the requirement to use very large ROM arrays in implementing the additions and subtraction and it limits its use to low-precision applications. MDLNS allows exponential reduction of the size of the ROMs used without affecting the speed of the computational process; moreover, the calculations over different bases and digits are completely independent, which makes this particular representation perfectly suitable for massively parallel DSP architectures. The use of more than one base has at least two extra advantages. Firstly, the proposed architecture allows us to obtain the final result straightforwardly in binary form, thus, there is no need of the exponential amplifier, used in the known LNS architectures. Secondly, the second base can be optimized in accordance to the specific digital filter characteristics. This leads to dramatic reduction of the exponents used and, consequently, to large area savings. We offer many examples showing the computational advantages of the proposed approach.
Rigatos, Gerasimos
2016-07-01
The Derivative-free nonlinear Kalman Filter is used for developing a communication system that is based on a chaotic modulator such as the Duffing system. In the transmitter's side, the source of information undergoes modulation (encryption) in which a chaotic signal generated by the Duffing system is the carrier. The modulated signal is transmitted through a communication channel and at the receiver's side demodulation takes place, after exploiting the estimation provided about the state vector of the chaotic oscillator by the Derivative-free nonlinear Kalman Filter. Evaluation tests confirm that the proposed filtering method has improved performance over the Extended Kalman Filter and reduces significantly the rate of transmission errors. Moreover, it is shown that the proposed Derivative-free nonlinear Kalman Filter can work within a dual Kalman Filtering scheme, for performing simultaneously transmitter-receiver synchronisation and estimation of unknown coefficients of the communication channel.
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 imple......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....
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.
Micro cycloid-gear system fabricated by multiexposure LIGA technique
Hirata, Toru; Chung, Song-Jo; Hein, Herbert; Akashi, Tomoyuki; Mohr, Juergen
1999-09-01
In this paper, a prototype of 2 mm-diameter micro-cycloid gear system fabricated by the multi-exposure LIGA technique is presented. The entire gear system consists of a casing and three vertically stacked disks and gears. Each part is composed of three different levels. The first level, 40 micrometers high, was fabricated by UV-lithography, and the second as well as the third level, 195 micrometers and 250 micrometers high respectively, were processed by aligned deep X-ray lithography (DXL). The alignment error between two DXL- processed layers was measured, and the results have turned out to be within +/- 5 micrometers range. As a result of the height control process by the mechanical surface machining, the deviation of structural height has been maintained within +/- 3 micrometers range for the UV-lithography-processed structures, and +/- 10 micrometers for the DXL-processed structures. Further the tests of gear assembly were implemented with 125 micrometers -diameter glass fiber, by using a die-bonding machine with vacuum gripper under stereo- microscope. Finally the dynamic tests of the gear system were successfully conducted with the mechanical torque input by an electrical motor. A proper rotational speed reduction was observed in the operational input range of 3 to 1500 rpm with the designed gear ratio of 18.
Energy Technology Data Exchange (ETDEWEB)
Miller, B.G.; Wincek, R.T.; Glick, D.C.; Scaroni, A.W. [Pennsylvania State Univ., University Park, PA (United States); Drury, K. [Corning Inc., Painted Post, NY (United States); Makris [Corning Inc., Acton, MA (United States); Stubblefield, D.J. [Corning Inc., Corning, NY (United States)
1998-12-31
Penn State is developing technologies for ultralow emissions when firing coal-based fuels, i.e., micronized coal and coal-water slurry fuel (CWSF) in industrial boilers. Emissions being addressed are SO{sub 2}, NOx, fine particulate matter (PM{sub 10} and PM{sub 2.5}), and air toxics (trace elements and volatile organic compounds). Results from trace element and polynuclear aromatic hydrocarbon emissions testing, when firing coal-based fuels, are reported elsewhere in these proceedings. This paper discusses the evaluation of ceramic membrane filters for fine particulate removal in a package boiler when firing micronized coal and CWSF.
Design, Fabrication and Certification of Advanced Modular PV Power Systems
Minyard, Glen E.; Lambarski, Timothy J.
1997-02-01
The Design, Fabrication and Certification of Advanced Modular PV Power Systems contract is a Photovoltaic Manufacturing Technology (PVMaT) cost-shared contract under Phase 4A1 for Product Driven Systems and Component Technologies. Phase 4A1 has the goals to improve the cost-effectiveness and manufacturing efficiency of PV end-products, optimize manufacturing and packaging methods, and generally improve balance-of-system performance, integration and manufacturing. This contract has the specific goal to reduce the installed PV system life cycle costs to the customer with the ultimate goal of increasing PV system marketability and customer acceptance. The specific objectives of the project are to develop certified, standardized, modular, pre-engineered products lines of our main stand-alone systems, the Modular Autonomous PV Power Supply (MAPPS) and PV-Generator Hybrid System (Photogenset). To date, we have designed a 200 W MAPPS and a 1 kW Photogenset and are in the process of having the MAPPS certified by Underwriters Laboratories (UL Listed) and approved for hazardous locations by Factory Mutual (FM). We have also developed a manufacturing plan for product line expansion for the MAPPS. The Photogenset will be fabricated in February 1997 and will also be UL Listed. Functionality testing will be performed at NREL and Sandia with the intentions of providing verification of performance and reliability and of developing test-based performance specifications. In addition to an expansion on the goals, objectives and status of the project, specific accomplishments and benefits are also presented in this paper.
Control of the polychromatic response of an optical system through the use of annular color filters.
Escalera, J C; Yzuel, M J; Campos, J
1995-04-01
The use of annular color filters as a tool to modify the polychromatic response of an optical system is investigated. The introduction of filters with transmission that depends on the wavelength produces a significant modification of the chromaticity response. In contrast, the position in the pupil of the annuli in which the color filters are placed modifies mainly the illuminance response. The influence of different types of annular color filter on the transverse and axial responses of the aberration-free system is studied.
Delay-Dependent H∞ Filtering for Singular Time-Delay Systems
Directory of Open Access Journals (Sweden)
Zhenbo Li
2011-01-01
Full Text Available This paper deals with the problem of delay-dependent H∞ filtering for singular time-delay systems. First, a new delay-dependent condition which guarantees that the filter error system has a prescribed H∞ performance γ is given in terms of linear matrix inequalities (LMIs. Then, the sufficient condition is obtained for the existence of the H∞ filter, and the explicit expression for the desired H∞ filter is presented by using LMIs and the cone complementarity linearization iterative algorithm. A numerical example is provided to illustrate the effectiveness of the proposed method.
Design of Super-resolution Filters with a Gaussian Beam in Optical Data Storage Systems
Institute of Scientific and Technical Information of China (English)
WANG Sha-Sha; ZHAO Xiao-Feng; LI Cheng-Fang; RUAN Hao
2008-01-01
@@ Super-resolution filters based on a Ganssian beam are proposed to reduce the focusing spot in optical data storage systems.Both of amplitude filters and pure-phase filters are designed respectively to gain the desired intensity distributions.Their performances are analysed and compared with those based on plane wave in detail.The energy utilizations are presented.The simulation results show that our designed super-resolution filters are favourable for use in optical data storage systems in terms of performance and energy utilization.
Fuzzy Logic Based Autonomous Parallel Parking System with Kalman Filtering
Panomruttanarug, Benjamas; Higuchi, Kohji
This paper presents an emulation of fuzzy logic control schemes for an autonomous parallel parking system in a backward maneuver. There are four infrared sensors sending the distance data to a microcontroller for generating an obstacle-free parking path. Two of them mounted on the front and rear wheels on the parking side are used as the inputs to the fuzzy rules to calculate a proper steering angle while backing. The other two attached to the front and rear ends serve for avoiding collision with other cars along the parking space. At the end of parking processes, the vehicle will be in line with other parked cars and positioned in the middle of the free space. Fuzzy rules are designed based upon a wall following process. Performance of the infrared sensors is improved using Kalman filtering. The design method needs extra information from ultrasonic sensors. Starting from modeling the ultrasonic sensor in 1-D state space forms, one makes use of the infrared sensor as a measurement to update the predicted values. Experimental results demonstrate the effectiveness of sensor improvement.
Volcano monitoring using the Global Positioning System: Filtering strategies
Larson, K.M.; Cervelli, Peter; Lisowski, M.; Miklius, Asta; Segall, P.; Owen, S.
2001-01-01
Permanent Global Positioning System (GPS) networks are routinely used for producing improved orbits and monitoring secular tectonic deformation. For these applications, data are transferred to an analysis center each day and routinely processed in 24-hour segments. To use GPS for monitoring volcanic events, which may last only a few hours, real-time or near real-time data processing and subdaily position estimates are valuable. Strategies have been researched for obtaining station coordinates every 15 min using a Kalman filter; these strategies have been tested on data collected by a GPS network on Kilauea Volcano. Data from this network are tracked continuously, recorded every 30 s, and telemetered hourly to the Hawaiian Volcano Observatory. A white noise model is heavily impacted by data outages and poor satellite geometry, but a properly constrained random walk model fits the data well. Using a borehole tiltmeter at Kilauea's summit as ground-truth, solutions using different random walk constraints were compared. This study indicates that signals on the order of 5 mm/h are resolvable using a random walk standard deviation of 0.45 cm/???h. Values lower than this suppress small signals, and values greater than this have significantly higher noise at periods of 1-6 hours. Copyright 2001 by the American Geophysical Union.
Volcano monitoring using the Global Positioning System: Filtering strategies
Larson, Kristine M.; Cervelli, Peter; Lisowski, Michael; Miklius, Asta; Segall, Paul; Owen, Susan
2001-09-01
Permanent Global Positioning System (GPS) networks are routinely used for producing improved orbits and monitoring secular tectonic deformation. For these applications, data are transferred to an analysis center each day and routinely processed in 24-hour segments. To use GPS for monitoring volcanic events, which may last only a few hours, real-time or near real-time data processing and subdaily position estimates are valuable. Strategies have been researched for obtaining station coordinates every 15 min using a Kalman filter; these strategies have been tested on data collected by a GPS network on Kilauea Volcano. Data from this network are tracked continuously, recorded every 30 s, and telemetered hourly to the Hawaiian Volcano Observatory. A white noise model is heavily impacted by data outages and poor satellite geometry, but a properly constrained random walk model fits the data well. Using a borehole tiltmeter at Kilauea's summit as ground-truth, solutions using different random walk constraints were compared. This study indicates that signals on the order of 5 mm/h are resolvable using a random walk standard deviation of 0.45 cm/√h. Values lower than this suppress small signals, and values greater than this have significantly higher noise at periods of 1-6 hours.
Energy Technology Data Exchange (ETDEWEB)
Guilio A. Rossi; Kenneth R. Butcher; Stacia M. Wagner
1999-02-19
The objective of this work was to fabricate subscale candle filters using a Ce-ZTA reticulated foam material. Specifically Selee fabricated 60mm diameter cylinders with one closed end and one flanged end. Selee Corporation developed a small pore size (5-10 {micro}m) filtration membrane which was applied to the reticulated foam surface to provide a barrier filter surface. The specific tasks to be performed were as follows: (Task 1) Filter Element Development--To fabricate subscale filter elements from zirconia toughened alumina using the reticulated foam manufacturing process. The filter elements were required to meet dimensional tolerances specified by an appropriate filter system supplier. The subscale filter elements were fabricated with integral flanges and end caps, that is, with no glued joints. (Task 2) Membrane Development--To develop a small pore filtration membrane that is to be applied to the reticulated foam material. This membrane was to provide filtration characteristics that meet gas turbine requirements and pressure drop or permeability requirements specified by the filter system supplier. (Task 3) Subscale Filter Element Fabrication--To fabricate six subscale filter elements with integral flanges and closed ends, as well as fine pore size filtration membranes. Three filters were to have a central clean gas channel, while three would have no central channel. The filters were to be provided to FETC for testing in laboratory systems or pilot scale exposure systems as appropriate. The candles were to meet dimensional tolerances as provided by filter system suppliers.
Application of biological filters in water treatment systems
Hurley, T. L.; Bambenek, R. A.
1973-01-01
Silver chloride placed on or close to barrier kills bacteria as they arrive. Dead bacteria accumulate linearly, whereas previously, live bacteria accumulated exponentially. During continuous 30-day tests, no bacteriological contamination was found downstream of filters with silver chloride added.
Nanochannel system fabricated by MEMS microfabrication and atomic force microscopy.
Wang, Z; Wang, D; Jiao, N; Tung, S; Dong, Z
2011-12-01
A silicon nanochannel system with integrated transverse electrodes was designed and fabricated by combining micro-electro-mechanical systems (MEMS) micromachining and atomic force microscopy (AFM)-based nanolithography. The fabrication process began with the patterning of microscale reservoirs and electrodes on an oxidised silicon chip using conventional MEMS techniques. A nanochannel, approximately 30 [micro sign]m long with a small semi-circular cross-sectional area of 20 nm × 200 nm, was then mechanically machined on the oxide surface between the micro reservoirs by applying AFM nanolithography with an all-diamond probe. Anodic bonding was used to seal off the nanochannel with a matching Pyrex cover. Continuous flow in the nanochannel was verified by pressurising a solution of fluorescein isothiocyanate in ethanol through the nanochannel in a vacuum chamber. It was further demonstrated by translocating negatively charged nanobeads (diameter approximately 20 nm) through the nanochannel by using an external DC electric field. The passage of the nanobeads caused a sharp increase in the transverse electrical conductivity of the nanochannel.
Robust H∞ Filtering for a Class of Uncertain Markovian Jump Systems with Time Delays
Directory of Open Access Journals (Sweden)
Yi Yang
2013-01-01
Full Text Available This paper studies the problem of robust H∞ filtering for a class of uncertain time-delay systems with Markovian jumping parameters. The system under consideration is subject to norm-bounded time-varying parameter uncertainties. The problem to be addressed is the design of a Markovian jump filter such that the filter error dynamics are stochastically stable and a prescribed bound on the ℒ2-induced gain from the noise signals to the filter error is guaranteed for all admissible uncertainties. A sufficient condition for the existence of the desired robust H∞ filter is given in terms of two sets of coupled algebraic Riccati inequalities. When these algebraic Riccati inequalities are feasible, the expression of a desired H∞ filter is also presented. Finally, an illustrative numerical example is provided.
Stable and efficient cubature-based filtering in dynamical systems
Ballreich, Dominik
2017-01-01
The book addresses the problem of calculation of d-dimensional integrals (conditional expectations) in filter problems. It develops new methods of deterministic numerical integration, which can be used to speed up and stabilize filter algorithms. With the help of these methods, better estimates and predictions of latent variables are made possible in the fields of economics, engineering and physics. The resulting procedures are tested within four detailed simulation studies.
Improvements to Filter Debris Analysis in Aviation Propulsion Systems
2012-12-01
filter patch containing the ferromagnetic debris is typically of most interest as critical oil- wetted components are typically made from ferrous alloys ...are typically manufactured using special steels with specific alloying elements. Elemental analysis using a Scanning electron Microscope (SEM) with...debris patch (left) and extracted ferrous debris patch (right) 2.2.1 Results A total of 48 filters were analysed during the trial from all four
S. Sellakumar; Vijayakumar, M.
2015-01-01
The inverter topology is being used as an active filter to reduce the harmonics in the power system [1]. The traditional voltage source or current source inverters are having the disadvantages of limited output voltage range hence it may not be able to supply enough compensating currents during heavy switching surges, Vulnerable to EMI noise and the devices gets damaged in either open or short circuit conditions and the main switching device of VSI and CSI are not interchangeable. The active ...
Fabrication and electronic transport studies of single nanocrystal systems
Energy Technology Data Exchange (ETDEWEB)
Klein, David Louis [Univ. of California, Berkeley, CA (United States). Dept. of Physics
1997-05-01
Semiconductor and metallic nanocrystals exhibit interesting electronic transport behavior as a result of electrostatic and quantum mechanical confinement effects. These effects can be studied to learn about the nature of electronic states in these systems. This thesis describes several techniques for the electronic study of nanocrystals. The primary focus is the development of novel methods to attach leads to prefabricated nanocrystals. This is because, while nanocrystals can be readily synthesized from a variety of materials with excellent size control, means to make electrical contact to these nanocrystals are limited. The first approach that will be described uses scanning probe microscopy to first image and then electrically probe surfaces. It is found that electronic investigations of nanocrystals by this technique are complicated by tip-sample interactions and environmental factors such as salvation and capillary forces. Next, an atomic force microscope technique for the catalytic patterning of the surface of a self assembled monolayer is described. In principle, this nano-fabrication technique can be used to create electronic devices which are based upon complex arrangements of nanocrystals. Finally, the fabrication and electrical characterization of a nanocrystal-based single electron transistor is presented. This device is fabricated using a hybrid scheme which combines electron beam lithography and wet chemistry to bind single nanocrystals in tunneling contact between closely spaced metallic leads. In these devices, both Au and CdSe nanocrystals show Coulomb blockade effects with characteristic energies of several tens of meV. Additional structure is seen the transport behavior of CdSe nanocrystals as a result of its electronic structure.
Directory of Open Access Journals (Sweden)
P. Kalyana Sundaram
2016-11-01
Full Text Available The paper presents a novel method for the assessment of the power quality disturbances in the distribution system using the Kalman filter and fuzzy expert system. In this method the various classes of disturbance signals are developed through the Matlab Simulink on the test system model. The characteristic features of the disturbance signals are extracted based on the Kalman filter technique. The obtained features such as amplitude and slope are given as the two inputs to the fuzzy expert system. It applied some rules on these inputs to assess the various PQ disturbances. Fuzzy classifier has been carried out and tested for various power quality disturbances. The results clearly demonstrate that the proposed method in the distribution system has the ability to detect and classify PQ events.
Error compensation on precision machine tool servo control system based on digital concave filter
Institute of Scientific and Technical Information of China (English)
王立松; 苏宝库; 张晶; 董申
2001-01-01
It is concluded from the results of testing the frequency characteristics of the sub-micron precision machine tool servo control system, that the existence of several oscillating modalities is the main factor that affects the performance of the control system. To compensate for this effect, several concave filters are utilized in the system to improve the control accuracy. The feasibility of compensating for several oscillating modalities with a single concave filter is also studied. By applying a modified Butterworth concave filter to the practical system, the maximum stable state output error remains under + 10 nm in the closed-loop positioning system.
Energy Technology Data Exchange (ETDEWEB)
Tsuji, H.; Yasutaka, T. [National Institute of Advanced Industrial Science and Technology (Japan); Kondo, Y. [Japan Vilene Company, Ltd (Japan); Suzuki, Y. [Fukushima Agricultural Technology Centre (Japan)
2014-07-01
The environmental monitoring of dissolved and particulate radiocesium in river became important after the accident of TEPCO Fukushima Daiichi Nuclear Power Plant. Traditional monitoring methods, such as evaporative concentration, require time for pre-processing because the concentration of dissolved radiocesium of river water in Fukushima prefecture is currently very low, averagely 0.001 - 0.1 Bq/L. Our research group has developed a monitoring method to investigate the radiocesium concentration in water by each existence form. Yasutaka et al. (2013) and Tsuji et al.(2013) developed a method for rapid and simultaneous monitoring of particulate and dissolved radiocesium in water with nonwoven fabric cartridge filters. This method uses pleated polypropylene nonwoven fabric filter with a pore size of 1-μm to collect particulate radiocesium, and nonwoven fabric impregnated with Prussian blue (PB) to absorb dissolved radiocesium. The fabric was placed into cylindrical plastic cartridges (SS-cartridge and PB-cartridge). This method could catch the 99% of the suspended solid (SS) and absorb 95% of dissolved radiocesium separately in 20 L water within 40 minutes. This device was applied to monitor the water in Abukuma River (January 2013) and upper area of Kuchibuto river (May 2013) at 12 locations, and the results were compared with those obtained by the filtrating and evaporative concentration method. The SS concentration and radioactivity of SS in the Abukuma river water, calculated by weight gain of the SS-cartridge and by sediment weight after filtration with a 0.45-μm membrane filter, agreed well without one location.The radioactivity of the dissolved {sup 137}Cs also agreed well between these two methods. In the Abukuma River, dissolved {sup 137}Cs was 0.006-0.025 Bq/L and particulate {sup 137}Cs was 0.008-0.070 Bq/L by the presented method in January 2013. In addition, the required time for pre-processing was reduced by more than 10 times that by filtrating and
A novel modular approach to active power-line harmonic filtering in distribution systems
Energy Technology Data Exchange (ETDEWEB)
El Shatshat, R.A.
2001-07-01
An efficient and reliable modular active harmonic filter system was developed as a cost-effective solution to the problem of harmonics. The newly developed filter system include several CSC modules that are each dedicated to filter a specific harmonic. Overall switching losses are minimized because selective harmonics is eliminated. Two ADALINEs are proposed for the filter controller. One extracts the fundamental and harmonic components of the distorted current, and the other estimates the line voltage. The main features of the new filter system are high speed, accuracy of ADALINE, self synchronizing harmonic tracking, intelligence and robustness of the controller, optimum dc value, and minimal converter losses. Simulation results were also presented to demonstrate the effectiveness of the system.
Robust dissipative filtering for continuous-time polytopic uncertain time-delay systems
Institute of Scientific and Technical Information of China (English)
LV Ling-ling; DUAN Guang-ren; WU Ai-guo
2010-01-01
This paper focuses on the problem of dissipative filtering for linear continuous-time polytopic uncertain time-delay systems.To obtain a stable and proper linear filter such that the filtering error system is strictly dissipative for all admissible uncertainties,a new dissipativity criterion which realizes separation between the Lyapunov matrices and the system dynamic matrices is firstly provided in terms of linear matrix inequalities (LMI).Then an LMI sufficient condition for the existence of a robust filter is established and a design procedure is proposed for this type of systems.One numerical example demonstrates less conservativeness of the proposed criterion,the other numerical example illustrates the validity of the proposed filter design.
Design of generalised orthogonal filters: application to the modelling of dynamical systems
Nikolić, Saša S.; Antić, Dragan S.; Perić, Staniša Lj.; Danković, Nikola B.; Milojković, Marko T.
2016-02-01
In this article, we define a new class of orthogonal filters with complex poles and zeroes inside their transfer function. This further improvement of classical orthogonal filters allows the possibility to model a wider range of real systems, that is, the systems whose mathematical models have complex zeroes besides real ones. These filters can be applied in the following areas: circuit theory, telecommunications, signal processing, bond graphs, theory approximations and control system theory. First, we describe the rational functions with complex poles and zeroes, and prove their orthogonality. Based on these functions, we designed the block diagram of orthogonal Legendre-type filter with complex poles and zeroes. After that an appropriate analogue scheme of this filter for practical realisation is derived. To validate theoretical results, we performed an experiment with a cascade-connected system designed and practically realised in our laboratories. The experiments proved the quality of the designed orthogonal model in terms of accuracy and simplicity.
Robust guaranteed cost filtering for uncertain time-delay systems with Markovian jumping parameters
Institute of Scientific and Technical Information of China (English)
Fu Yanming; Zhang Ying; Duan Guangren; Chai Qingxuan
2005-01-01
The robust guaranteed cost filtering problem for a class of linear uncertain stochastic systems with time delays is investigated. The system under study involves time delays, jumping parameters and Brownian motions. The transition of the jumping parameters in systems is governed by a finite-state Markov process. The objective is to design linear memoryless filters such that for all uncertainties, the resulting augmented system is robust stochastically stable independent of delays and satisfies the proposed guaranteed cost performance. Based on stability theory in stochastic differential equations, a sufficient condition on the existence of robust guaranteed cost filters is derived. Robust guaranteed cost filters are designed in terms of linear matrix inequalities. A convex optimization problem with LMI constraints is formulated to design the suboptimal guaranteed cost filters.
Takagi-Sugeno Fuzzy Systems Non-fragile H-infinity Filtering
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.
Design and fabrication of a glovebox for the Plasma Hearth Process radioactive bench-scale system
Energy Technology Data Exchange (ETDEWEB)
Wahlquist, D.R. [Argonne National Lab., Idaho Falls, ID (United States). Technology Development Div.
1996-07-01
This paper presents some of the design considerations and fabrication techniques for building a glovebox for the Plasma Hearth Process (PHP) radioactive bench-scale system. The PHP radioactive bench-scale system uses a plasma torch to process a variety of radioactive materials into a final vitrified waste form. The processed waste will contain plutonium and trace amounts of other radioactive materials. The glovebox used in this system is located directly below the plasma chamber and is called the Hearth Handling Enclosure (HHE). The HHE is designed to maintain a confinement boundary between the processed waste and the operator. Operations that take place inside the HHE include raising and lowering the hearth using a hydraulic lift table, transporting the hearth within the HHE using an overhead monorail and hoist system, sampling and disassembly of the processed waste and hearth, weighing the hearth, rebuilding a hearth, and sampling HEPA filters. The PHP radioactive bench-scale system is located at the TREAT facility at Argonne National Laboratory-West in Idaho Falls, Idaho.
A filter algorithm for multi-measurement nonlinear system with parameter perturbation
Institute of Scientific and Technical Information of China (English)
GUO Yun-fei; WEI Wei; XUE An-ke; MAO Dong-cai
2006-01-01
An improved interacting multiple models particle filter (IMM-PF) algorithm is proposed for multi-measurement nonlinear system with parameter perturbation. It divides the perturbation region into sub-regions and assigns each of them a particle filter. Hence the perturbation problem is converted into a multi-model filters problem. It combines the multiple measurements into a fusion value according to their likelihood function. In the simulation study, we compared it with the IMM-KF and the H-infinite filter; the results testify to its advantage over the other two methods.
Filter-Bank-Based Narrowband Interference Detection and Suppression in Spread Spectrum Systems
Directory of Open Access Journals (Sweden)
Tobias Hidalgo Stitz
2004-07-01
Full Text Available A filter-bank-based narrowband interference detection and suppression method is developed and its performance is studied in a spread spectrum system. The use of an efficient, complex, critically decimated perfect reconstruction filter bank with a highly selective subband filter prototype, in combination with a newly developed excision algorithm, offers a solution with efficient implementation and performance close to the theoretical limit derived as a function of the filter bank stopband attenuation. Also methods to cope with the transient effects in case of frequency hopping interference are developed and the resulting performance shows only minor degradation in comparison to the stationary case.
A Robust Filter Design for Uncertain Singular Systems with Unreliable Channels
Directory of Open Access Journals (Sweden)
Ching-Min Lee
2011-06-01
Full Text Available This paper considers the problem of robust H_∞ filter design in uncertain discrete-time singular systems with possible missing measurements due to unreliable network transmission channels. The stochastic variable satisfying Bernoulli random binary distribution is introduced to model the missing phenomena and the corresponding filtering error dynamics with delay is then induced. We provide a set of sufficient conditions for the existence of the desired filter, and propose a robust filter design method under a strict linear matrix inequality framework. A numerical example is given to illustrate the effectiveness of the proposed method
Design of Microwave Band Pass Filters for the Debuncher Stochastic Cooling System
Energy Technology Data Exchange (ETDEWEB)
Deibele, C.; /Fermilab
2001-01-01
The FIR filters designed for the debuncher stochastic cooling system needed improvement. Its bandwidth was too wide, its magnitude was not flat, its phase ripple was too great, and it was difficult to control the characteristics of the filter. A simple microwave technique was employed to have a short time delay, simple robust layout, and small board size. A significant savings was seen over the FIR technique and these filters were installed in the Antiproton Source Debuncher while the FIR filters were removed from the debuncher stochastic cooling entirely.
Impact of Spectral Filter on Phase Modulation Pulse in Fiber Front End System
Institute of Scientific and Technical Information of China (English)
LI Jing; JING Feng; WANG Jian-Jun; XU Dang-Peng; LIN Hong-Huan; GENG Yuan-Chao; LI Ming-Zhong; DENG Ying; ZHU Na; ZHANG Rui
2011-01-01
The transmission characteristics of phase modulation pulse transmitted through the filter in the power amplifier are investigated theoretically and experimentally. The narrow bandpass filter can induce large temporal modula-tion depth for the phase modulation pulse and induce double amplitude modulation(AM)if the frequency shift is lower than half bandwidth of the signal spectrum. We should choose a wider bandwidth filter to minimize the impact of the filter on the output pulse and suppress the amplified spontaneous emission(ASE) for the power fiber amplifier. These results are of benefit to the design of the fiber front end system.
Directory of Open Access Journals (Sweden)
Hua-Ming Qian
2014-01-01
Full Text Available A robust filtering problem is formulated and investigated for a class of nonlinear systems with correlated noises, packet losses, and multiplicative noises. The packet losses are assumed to be independent Bernoulli random variables. The multiplicative noises are described as random variables with bounded variance. Different from the traditional robust filter based on the assumption that the process noises are uncorrelated with the measurement noises, the objective of the addressed robust filtering problem is to design a recursive filter such that, for packet losses and multiplicative noises, the state prediction and filtering covariance matrices have the optimized upper bounds in the case that there are correlated process and measurement noises. Two examples are used to illustrate the effectiveness of the proposed filter.
Estimation of noise parameters in dynamical system identification with Kalman filters.
Kwasniok, Frank
2012-09-01
A method is proposed for determining dynamical and observational noise parameters in state and parameter identification from time series using Kalman filters. The noise covariances are estimated in a secondary optimization by maximizing the predictive likelihood of the data. The approach is based on internal consistency; for the correct noise parameters, the uncertainty projected by the Kalman filter matches the actual predictive uncertainty. The method is able to disentangle dynamical and observational noise. The algorithm is demonstrated for the linear, extended, and unscented Kalman filters using an Ornstein-Uhlenbeck process, the noise-driven Lorenz system, and van der Pol oscillator as well as a paleoclimatic ice-core record as examples. The approach is also applicable to the ensemble Kalman filter and can be readily extended to non-Gaussian estimation frameworks such as Gaussian-sum filters and particle filters.
Hydrogen risk in the Containment Filtered Venting System
Energy Technology Data Exchange (ETDEWEB)
Na, Young Su; Ha, Kwang Soon [KAERI, Daejeon (Korea, Republic of); Cho, Song-Won [NSE, Daejeon (Korea, Republic of)
2015-05-15
It was observed that the thermal hydraulic conditions in the CFVS (Containment Filtered Venting System) vessel sharply changed markedly, especially the steam condensation in the early CFVS operation can affect the hydrogen behavior such as the combustion. This paper summarizes the calculated results on hydrogen concentration in the CFVS vessel, which was presented at The Ninth Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS9) last year. The MELCOR computer code calculated the thermal-hydraulic conditions in the containment building of OPR 1000, and in the cylindrical CFVS vessel with 3 m in diameter and 6.5 m in height under an SBO. After the operation of the CFVS, the pressure and temperature in the containment building decreased, and those in the CFVS vessel jumped from the initial conditions of atmosphere pressure and room temperature. These big differences of thermal-hydraulic conditions can make the volumetric concentrations of steam and gas mixtures in the CFVS vessel to be changed in comparison with those in the containment building. The volumetric concentration of hydrogen increased from 6% in the containment to 14% in the CFVS vessel after the operation of the CFVS, while the concentration of steam decreased from 58% in the containment to 3% in the CFVS vessel. The increased volumetric concentration of hydrogen (14%) with the other concentrations of steam (3%) and air (60%) in the CFVS vessel exists within the region of the burn limit in the Shapiro diagram. This possibility of the hydrogen combustion can threaten the integrity of the CFVS.
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.
Kalman Filter Based Tracking in an Video Surveillance System
Directory of Open Access Journals (Sweden)
SULIMAN, C.
2010-05-01
Full Text Available In this paper we have developed a Matlab/Simulink based model for monitoring a contact in a video surveillance sequence. For the segmentation process and corect identification of a contact in a surveillance video, we have used the Horn-Schunk optical flow algorithm. The position and the behavior of the correctly detected contact were monitored with the help of the traditional Kalman filter. After that we have compared the results obtained from the optical flow method with the ones obtained from the Kalman filter, and we show the correct functionality of the Kalman filter based tracking. The tests were performed using video data taken with the help of a fix camera. The tested algorithm has shown promising results.
Robust H-infinity filtering on uncertain systems under sampled measurements
Institute of Scientific and Technical Information of China (English)
Ping SUN; Yuanwei JING
2006-01-01
This paper is concerned with the problem of robust H-infinity filtering on uncertain systems under sampled measurements, both continuous disturbance and discrete disturbance are considered in the systems. The parameter uncertainty is assumed to be time-varying norm-bounded. The aim is to design an asymptotically stable filter, using the locally sampled measurements, which ensures both the robust asymptotic stability and a prescribed level of H-infinity performance for the filtering error dynamics for all admissible uncertainties. The derivation process is simplified by introducing auxiliary systems and the sufficient condition for the existence of such a filter is proposed. During the study, the main results were expressed as LMIs by employing various matrix techniques. Using LMI toolbox of Matlab software, it is very convenient to obtain the appropriate filter. Finally, a numerical example shows that the method is effective and feasible.
Particle filter with importance density function generated by updated system equation
Institute of Scientific and Technical Information of China (English)
左军毅; 贾颖娜; 张炜; 高全学
2013-01-01
The current measurement was exploited in a more efficient way. Firstly, the system equation was updated by introducing a correction term, which depends on the current measurement and can be obtained by running a suboptimal filter. Then, a new importance density function(IDF) was defined by the updated system equation. Particles drawn from the new IDF are more likely to be in the significant region of state space and the estimation accuracy can be improved. By using different suboptimal filter, different particle filters(PFs) can be developed in this framework. Extensions of this idea were also proposed by iteratively updating the system equation using particle filter itself, resulting in the iterated particle filter. Simulation results demonstrate the effectiveness of the proposed IDF.
Integration of micro-fabricated atomic magnetometers on military systems
Schultz, Gregory; Mhaskar, Rahul; Prouty, Mark; Miller, Jonathan
2016-05-01
A new generation of ultra-high sensitivity magnetic sensors based on innovative micro-electromechanical systems (MEMS) are being developed and incorporated into military systems. Specifically, we are currently working to fully integrate the latest generation of MicroFabricated Atomic Magnetometers (MFAMs) developed by Geometrics on defense mobility systems such as unmanned systems, military vehicles and handheld units. Recent reductions in size, weight, and power of these sensors has enabled new deployment opportunities for improved sensitivity to targets of interest, but has also introduced new challenges associated with noise mitigation, mission configuration planning, and data processing. Our work is focused on overcoming the practical aspects of integrating these sensors with various military platforms. Implications associated with utilizing these combined sensor systems in working environments are addressed in order to optimize signal-to-noise ratios, detection probabilities, and false alarm mitigation. Specifically, we present collaborative work that bridges the gap between commercial specialists and operation platform integration organizations including magnetic signature characterization and mitigation as well as the development of simulation tools that consider a wide array of sensor, environmental, platform, and mission-level parameters. We discuss unique deployment concepts for explosive hazard target geolocation, and data processing. Applications include configurations for undersea and underground threat detection - particularly those associated with stationary or mobile explosives and compact metallic targets such as munitions, subsea threats, and other hazardous objects. We show the potential of current and future features of miniaturized magnetic sensors including very high magnetic field sensitivities, bandwidth selectivity, and array processing.
Fabrication of PLGA nanoparticles with a fluidic nanoprecipitation system
Directory of Open Access Journals (Sweden)
Xie Hui
2010-08-01
Full Text Available Abstract Particle size is a key feature in determining performance of nanoparticles as drug carriers because it influences circulating half-life, cellular uptake and biodistribution. Because the size of particles has such a major impact on their performance, the uniformity of the particle population is also a significant factor. Particles comprised of the polymer poly(lactic-co-glycolic acid (PLGA are widely studied as therapeutic delivery vehicles because they are biodegradable and biocompatible. In fact, microparticles comprised of PLGA are already approved for drug delivery. Unfortunately, PLGA nanoparticles prepared by conventional methods usually lack uniformity. We developed a novel Fluidic NanoPrecipitation System (FNPS to fabricate highly uniform PLGA particles. Several parameters can be fine-tuned to generate particles of various sizes.
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.
Liu, Xiaoyang; Yu, Wenwu; Cao, Jinde; Chen, Shun
2015-08-01
This paper is concerned with the sampled-data state estimation and H(∞) filtering for a class of Markovian jump systems with the discontinuous Lyapunov approach. The system measurements are sampled and then transmitted to the estimator and filter in order to estimate the state of the jumped system under consideration. The corresponding error dynamics is represented by a system with two types of delays: one is from the system itself, and the other from the sampling period. As the delay due to sampling is discontinuous, a corresponding discontinuous Lyapunov functional is constructed, and sufficient conditions are established so as to guarantee both the asymptotic mean-square stability and the H(∞) performance for the filtering error systems. The explicit expressions of the desired estimator and filter are further provided. Finally, two simulation examples are given to illustrate the design procedures and performances of the proposed method.
Nodehi, S.; Mohammed, W. S.; Ahmad, H.; Harun, S. W.
2016-04-01
This work proposes a novel design of a hybrid microfiber resonator which can be used as a band-pass and band-stop filter in various applications such as fiber lasers. The structure comprises of two microfiber knot resonators with different sizes which are surrounded by a semi-loop structure with one input and two output ports. Utilization of the Vernier effect in the proposed structure showed an enhancement of the free spectral range (FSR). The finesse has increased by a factor of three compared to a single knot providing a sharper roll-off. The filter bandwidth is adjustable as a result of the manipulation of the coupling length and rings' radii. The performance of the device is explained theoretically using transfer matrix analysis.
A low pressure filter system for new containment concepts
Energy Technology Data Exchange (ETDEWEB)
Dillmann, H.G.; Pasler, H. [Kernforschungszentrum Karlsruhe GmbH Laboratorium fuer Isotopentechnik, Karlsruhe (Germany)
1995-02-01
It is demonstrated that after severe accidents the decay heat can be removed in a passive mode in a convective flow, i.e. without needing a fan. The filter components with sufficiently low pressure drop values which are required for this purpose will be described and the results indicated.
'Active' filters for upgrading phosphorus removal from pond systems.
Shilton, A; Pratt, S; Drizo, A; Mahmood, B; Banker, S; Billings, L; Glenny, S; Luo, D
2005-01-01
This paper investigates limestone and iron slag filters as an upgrade option for phosphorus removal from wastewater treatment ponds. A review of 'active' filter technology and the results from laboratory and field research using packed columns of the different media is presented. It is shown that both limestone and iron slag can remove phosphorus but highlights that different types of limestone give markedly different performance. Filter performance appears to be improved by increasing temperature and by the presence of algae, presumably because of its tendency to elevate pH. Performance is related to hydraulic retention time (HRT), but this relationship is not linear, particularly at low HRTs. Importantly for future research, the results from field-testing with pond effluent show significant differences compared to those obtained when using a synthetic feed in the laboratory. For the iron slag filter, higher performance was observed in the field (72% in field vs. 27% in laboratory, at a 12 hour-HRT), while the opposite was observed for the limestone (64% in laboratory vs. 18% in field, at a 12-hour HRT).
Normal incidence narrowband transmission filtering in zero-contrast gratings
Cui, Xuan; Du, Yan; Tan, Peng; Shi, Guang; Zhou, Zhongxiang
2015-01-01
We report narrowband transmission filtering based on zero-contrast grating (ZCG) reflectors at normal incidence. Computational results show that the filtering is realized through symmetry-protected modes coupling. The guided modes introduced by the slab layer make the filter frequencies flexible to modify. The rectangular structure of the filter allows simple fabrication and integration into optical systems. The quality factor of the filters could exceed 106. Owing to the low refraction index dispersion of the semiconductor and their scale-invariant operations, these filters can be applied in a broad infrared range from near infrared to terahertz wavelengths.
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.
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.
Efficient decoding with steady-state Kalman filter in neural interface systems.
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.
Federated unscented particle filtering algorithm for SINS/CNS/GPS system
Institute of Scientific and Technical Information of China (English)
HU Hai-dong; HUANG Xian-lin; LI Ming-ming; SONG Zhuo-yue
2010-01-01
To solve the problem of information fusion in the strapdown inertial navigation system(SINS)/celestial navigation system(CNS)/global positioning system(GPS)integrated navigation system described by the nonlinear/non-Gaussian error models,a new algorithm called the federated unscented particle filtering(FUPF)algorithm was introduced.In this algorithm,the unscented particle filter(UPF)served as the local filter,the federated filter was used to fuse outputs of all local filters,and the global filter result was obtained.Because the algorithm was not confined to the assumption of Gaussian noise,it was of great significance to integrated navigation systems described by the non-Gaussian noise.The proposed algorithm was tested in a vehicle's maneuvering trajectory,which included six flight phases: climbing,level flight,left turning,level flight,right turning and level flight.Simulation results are presented to demonstrate the improved performance of the FUPF over conventional federated unscented Kalman filter(FUKF).For instance,the mean of position-error decreases from(0.640×10 6 rad,0.667×10 6 rad,4.25 m)of FUKF to(0.403×10-6 rad,0.251 × 10 6 rad,1.36 m)of FUPF.In comparison of the FUKF,the FUPF performs more accurate in the SINS/CNS/GPS system described by the nonlinear/non-Gaussian error models.
WO3∕SiO2 composite optical films for the fabrication of electrochromic interference filters.
Baloukas, Bill; Martinu, Ludvik
2012-06-01
New security devices based on innovative technologies and ideas are essential in order to limit counterfeiting's profound impact on our economy and society. Interference security image structures have been in circulation for more than 20 years, but commercially available iridescent products now represent a potential threat. Therefore, the introduction of active materials, such as electrochromic WO3, to present-day optical security devices offers interesting possibilities. We have previously proposed electrochromic interference filters based on porous and dense WO3, which possessed an angle-dependent and voltage-driven color shift. However, the low index contrast required filters with a high number of layers. In this article, we increase the index contrast (0.61) by mixing WO3 with SiO2 and study the physical and electrochromic properties of mixtures. We next combine high and low index films in tandem configurations to observe the bleaching/coloration dynamics. To account for the film performance, we propose a simple explanation based on the differences in electron diffusion coefficients. An 11 layer electrochromic interference filter (EIF) based on the alternation of pure WO3 and (WO3)0.17(SiO2)0.83 films with a blue to purple angular color shift is then presented. Finally, we discuss possible applications of these EIFs for security.
Delay-dependent H-infinity filtering for neutral time-delay systems
Institute of Scientific and Technical Information of China (English)
Huiying LI; Guifang LI; Chengwu YANG
2006-01-01
This paper deals with the robust delay-dependent H-infinity filtering problem for neutral delay differential systems. The resulting filter is of the Luenberger observer type, and it guarantees that the filtering systems remains asymptotically stable and satisfies a prescribed H-infinity performance level. The Lyapunov stability theory and the descriptor model transformation are used for analysis of the system and are expected to be least conservative as compared with existing design methods. Some examples are provided to demonstrate the validity of proposed design approach.
The validity of high-pass angular spectrum filter in solid immersion lens system
Institute of Scientific and Technical Information of China (English)
Zheng Chong-Wei; Dai Yu-Xing
2005-01-01
The focal field of a solid immersion lens (SIL) system with a high-pass angular spectrum filter is calculated by using a vector method. Numerical results show that for a radially (azimuthally) polarized input field, a high-pass angular spectrum filter can reduce the light-spot (dark-spot) size of the SIL system. For a linearly polarized input field,however, the focal field cannot be optimized and the optical storage density of the SIL system cannot be improved by using a simple high-pass filter, either.
An evaluation of the filtration performance of paediatric breathing system filters at low flows.
Malan, C A; Wilkes, A R; Hall, J E; Gildersleve, C
2007-05-01
The filtration performance of five different types of filter intended for use in paediatric anaesthesia was measured. A total of 120 unused filters (24 samples of each filter type) were evaluated. The pressure drop and filtration performance, using challenges of sodium chloride particles, were measured for each filter at 3 l min(-1) and 15 l min(-1). The pressure drop was less at the lower flow; there was a wide variation in the pressure drop across some filters. The filtration performance of all filter types showed an improvement at 3 l min(-1) compared to 15 l min(-1). Four filter types had filtration efficiencies greater than 95% at 15 l min(-1) and greater than 99% at 3 l min(-1). The remaining filter type had a filtration efficiency less than 90% at 15 l min(-1) and greater than 95% at 3 l min(-1). These levels of performance are comparable to that of breathing system filters intended for use in adult anaesthesia using flows representing mean inspiratory flow.
Shaharudin Nuraida; Suradi Nurfarhana; Mohd Kamil Nor Amani Filzah
2017-01-01
An adequate supply of safe drinking water is one of major ways to obtain healthy life. Water filter system is one way to improve the water quality. However, to maintain the performance of the system, it need to undergo the maintenance service. This study evaluate the requirement of maintenance service in water filter system. Water quality was measured before and after maintenance service. Parameters measured were pH, turbidity, residual chlorine, nitrate and heavy metals and these parameters ...
A New Adaptive Square-Root Unscented Kalman Filter for Nonlinear Systems with Additive Noise
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Yong Zhou
2015-01-01
Full Text Available The Kalman filter (KF, extended KF, and unscented KF all lack a self-adaptive capacity to deal with system noise. This paper describes a new adaptive filtering approach for nonlinear systems with additive noise. Based on the square-root unscented KF (SRUKF, traditional Maybeck’s estimator is modified and extended to nonlinear systems. The square root of the process noise covariance matrix Q or that of the measurement noise covariance matrix R is estimated straightforwardly. Because positive semidefiniteness of Q or R is guaranteed, several shortcomings of traditional Maybeck’s algorithm are overcome. Thus, the stability and accuracy of the filter are greatly improved. In addition, based on three different nonlinear systems, a new adaptive filtering technique is described in detail. Specifically, simulation results are presented, where the new filter was applied to a highly nonlinear model (i.e., the univariate nonstationary growth model (UNGM. The UNGM is compared with the standard SRUKF to demonstrate its superior filtering performance. The adaptive SRUKF (ASRUKF algorithm can complete direct recursion and calculate the square roots of the variance matrixes of the system state and noise, which ensures the symmetry and nonnegative definiteness of the matrixes and greatly improves the accuracy, stability, and self-adaptability of the filter.
Anderson, Brian D O
2005-01-01
This graduate-level text augments and extends beyond undergraduate studies of signal processing, particularly in regard to communication systems and digital filtering theory. Vital for students in the fields of control and communications, its contents are also relevant to students in such diverse areas as statistics, economics, bioengineering, and operations research.Topics include filtering, linear systems, and estimation; the discrete-time Kalman filter; time-invariant filters; properties of Kalman filters; computational aspects; and smoothing of discrete-time signals. Additional subjects e
Directory of Open Access Journals (Sweden)
Pei-Chann Chang
2016-07-01
Full Text Available This research proposes a two-stage user-based collaborative filtering process using an artificial immune system for the prediction of student grades, along with a filter for professor ratings in the course recommendation for college students. We test for cosine similarity and Karl Pearson (KP correlation in affinity calculations for clustering and prediction. This research uses student information and professor information datasets of Yuan Ze University from the years 2005–2009 for the purpose of testing and training. The mean average error and confusion matrix analysis form the testing parameters. A minimum professor rating was tested to check the results, and observed that the recommendation systems herein provide highly accurate results for students with higher mean grades.
A SEMANTIC-BASED COLLABORATIVE FILTERING FOR RECOMMENDATION SYSTEMS
D.Jagadish *, A.Vishnu Kumar, R.Mani Raj
2016-01-01
In the present days the web domain is improved with new types of services, with the increase in service and cloud computing. As a result new forms of web content collecting/designing is done based on the numerous openly available web services online. These services are utilized in many ways by different domains and with the exponential growth of these web services users are experiencing difficulties in finding and utilizing a best matching service for their mashup. A collaborative filtering a...
Kalman Filter Based Tracking in an Video Surveillance System
SULIMAN, C.; CRUCERU, C.; Moldoveanu, F.
2010-01-01
In this paper we have developed a Matlab/Simulink based model for monitoring a contact in a video surveillance sequence. For the segmentation process and corect identification of a contact in a surveillance video, we have used the Horn-Schunk optical flow algorithm. The position and the behavior of the correctly detected contact were monitored with the help of the traditional Kalman filter. After that we have compared the results obtained from the optical flow method with the ones obtaine...
Shen, Mouquan; Park, Ju H
2016-07-01
This paper addresses the H∞ filtering of continuous Markov jump linear systems with general transition probabilities and output quantization. S-procedure is employed to handle the adverse influence of the quantization and a new approach is developed to conquer the nonlinearity induced by uncertain and unknown transition probabilities. Then, sufficient conditions are presented to ensure the filtering error system to be stochastically stable with the prescribed performance requirement. Without specified structure imposed on introduced slack variables, a flexible filter design method is established in terms of linear matrix inequalities. The effectiveness of the proposed method is validated by a numerical example.
Design of Filter for a Class of Switched Linear Neutral Systems
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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.
Rigatos, Gerasimos G
2015-01-01
This monograph presents recent advances in differential flatness theory and analyzes its use for nonlinear control and estimation. It shows how differential flatness theory can provide solutions to complicated control problems, such as those appearing in highly nonlinear multivariable systems and distributed-parameter systems. Furthermore, it shows that differential flatness theory makes it possible to perform filtering and state estimation for a wide class of nonlinear dynamical systems and provides several descriptive test cases. The book focuses on the design of nonlinear adaptive controllers and nonlinear filters, using exact linearization based on differential flatness theory. The adaptive controllers obtained can be applied to a wide class of nonlinear systems with unknown dynamics, and assure reliable functioning of the control loop under uncertainty and varying operating conditions. The filters obtained outperform other nonlinear filters in terms of accuracy of estimation and computation speed. The bo...
PERFORMANCE IMPROVEMENT FOR PAPR REDUCTION IN LTE DOWNLINK SYSTEM WITH ELLIPTIC FILTERING
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Snikdho Sworov Haque
2015-01-01
Full Text Available This paper is concerned with the performance improvement of PAPR reduction of orthogonal frequency division multiplexing (OFDM signal using amplitude clipping & filtering based design. Note that OFDM is one of the well adept multi-carrier multiplexing transmission scheme which has been implemented in long term evolution (LTE downlink. Nonetheless peak to average power ratio (PAPR is the more rattling problem with OFDM, consequently in this paper a reduction procedure of the PAPR by using amplitude clipping and filtering is proposed. Here we used IIR bandpass elliptic filter after amplitude clipping to reduce the PAPR. The performance of the system in terms of bit error rate (BER is also canvased as a new filter based clipping method. Our results show that the proposed methodology of clipping method with the IIR elliptic band pass filter significantly reduces the PAPR value.
H∞ deconvolution filter design for time-delay linear continuous-time systems
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Proposes an H∞ deconvolution design for time-delay linear continuous-time systems. We first analyze the general structure and innovation structure of the H∞ deconvolution filter. The deconvolution filter with innovation structure is made up of an output observer and a linear mapping, where the latter reflects the internal connection between the unknown input signal and the output estimate error. Based on the bounded real lemma,a time domain design approach and a sufficient condition for the existence of deconvolution filter are presented.The parameterization of the deconvolution filter can be completed by solving a Riccati equation. The proposed method is useful for the case that does not require statistical information about disturbances. At last, a numerical example is given to demonstrate the performance of the proposed filter.
Hardware-efficient realization of a real-time ultrasonic target detection system using IIR filters.
Oruklu, Erdal; Saniie, Jafar
2009-06-01
In this study, we address the increased computational demands of a frequency-diverse ultrasonic target detection system by developing a zero-phase IIR (ZP-IIR) filter. Several ZP-IIR filter types including Chebyshev-I, Chebyshev- II, and Butterworth were analyzed for their detection performance. The 4th-order filters with 8-bit quantized coefficients are shown to improve the flaw-to-clutter ratio by approximately 10 dB. Furthermore, the reduced adder graph algorithm is used for a hardware realization of ZP-IIR filters that does not require any dedicated multipliers. A small number of coefficients inherent to IIR filters and their multiplierless implementation provide efficient architecture suitable for compact, real-time ultrasonic imaging devices.
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
2D Face Recognition System Based on Selected Gabor Filters and Linear Discriminant Analysis LDA
Hafez, Samir F.; Selim, Mazen M.; Hala H. Zayed
2015-01-01
We present a new approach for face recognition system. The method is based on 2D face image features using subset of non-correlated and Orthogonal Gabor Filters instead of using the whole Gabor Filter Bank, then compressing the output feature vector using Linear Discriminant Analysis (LDA). The face image has been enhanced using multi stage image processing technique to normalize it and compensate for illumination variation. Experimental results show that the proposed system is effective for ...
Ballandras, S.; Courjon, E.; Baron, T.; Moulet, J.-B.; Signamarcheix, T.; Daniau, W.
SAW devices are widely used for radio-frequency (RF) telecommunication filtering and the number of SAW filters, resonators or duplexers is still increasing in RF stage of cellular phones. Therefore, a strong effort is still dedicated to reduce as much as possible their sensitivity to environmental parameter and more specifically to temperature. Bounding processes have been developed at FEMTO-ST and CEA-LETI using either Au/Au or direct bonding techniques for the fabrication of composite wafers combining materials with very different thermoelastic properties, yielding innovative solutions for about-zero temperature coefficient of frequency (TCF) bulk acoustic wave devices. In the present work, this approach has been applied to (YXl)/42∘ lithium tantalate plates, bounded onto (100) silicon wafers and thinned down to 25 μm. The leading idea already explored by other groups as mentioned in introduction consists in impeding the thermal expansion of the piezoelectric material using silicon limited expansion. 2 GHz resonators have been built on such plates and tested electrically and thermally, first by tip probing. A dramatic reduction of the TCF is observed for all the tested devices, allowing to reduce the thermal drift of the resonators down to a few ppm.K-1 within the standard temperature range. We then propose an analysis of the frequency-temperature behavior of the device to improve the resonator design to use these wafers for industrial applications.
Asynchronous H∞ filtering for linear switched systems with average dwell time
Wang, Bo; Zhang, Hongbin; Wang, Gang; Dang, Chuangyin
2016-09-01
This paper is concerned with the H∞ filtering problem for a class of continuous-time linear switched systems with the asynchronous behaviours, where 'asynchronous' means that the switching of the filters to be designed has a lag to the switching of the system modes. By using the Lyapunov-like functions and the average dwell time technique, a sufficient condition is obtained to guarantee the asymptotic stability with a weighted H∞ performance index for the filtering error system. Moreover, the results are formulated in the form of linear matrix inequalities that are numerical feasible. As a result, the filter design problem is solved. Finally, an illustrative numerical example is presented to show the effectiveness of the results.
Control of underactuated robotic systems with the use of the derivative-free nonlinear Kalman filter
Rigatos, Gerasimos G.; Siano, Pierluigi
2013-10-01
The Derivative-free nonlinear Kalman Filter is used for developing a robust controller which can be applied to underactuated MIMO robotic systems. Using differential flatness theory it is shown that the model of a closed-chain 2-DOF robotic manipulator can be transformed to linear canonical form. For the linearized equivalent of the robotic system it is shown that a state feedback controller can be designed. Since certain elements of the state vector of the linearized system can not be measured directly, it is proposed to estimate them with the use of a novel filtering method, the so-called Derivative-free nonlinear Kalman Filter. Moreover, by redesigning the Kalman Filter as a disturbance observer, it is is shown that one can estimate simultaneously external disturbances terms that affect the robotic model or disturbance terms which are associated with parametric uncertainty.
Reliable filtering with strict dissipativity for T-S fuzzy time-delay systems.
Su, Xiaojie; Shi, Peng; Wu, Ligang; Basin, Michael V
2014-12-01
In this paper, the problem of reliable filter design with strict dissipativity has been investigated for a class of discrete-time T-S fuzzy time-delay systems. Our attention is focused on the design of a reliable filter to ensure a strictly dissipative performance for the filtering error system. Based on the reciprocally convex approach, firstly, a sufficient condition of reliable dissipativity analysis is proposed for T-S fuzzy systems with time-varying delays and sensor failures. Then, a reliable filter with strict dissipativity is designed by solving a convex optimization problem, which can be efficiently solved by standard numerical algorithms. Finally, numerical examples are provided to illustrate the effectiveness of the developed techniques.
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.
Reliable Finite Frequency Filter Design for Networked Control Systems with Sensor Faults
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He-Hua Ju
2012-06-01
Full Text Available This paper is concerned with the reliable finite frequency filter design for networked control systems (NCSs subject to quantization and data missing. Taking into account quantization, possible data missing and sensor stuck faults, NCSs are modeled in the framework of discrete time-delay switched systems, and the finite frequency l_{2} gain is adopted for the filter design of discrete time-delay switched systems, which is converted into a set of linear matrix inequality (LMI conditions. By the virtues of the derived conditions, a procedure of reliable filter synthesis is presented. Further, the filter gains are characterized in terms of solutions to a convex optimization problem which can be solved by using the semi-definite programme method. Finally, an example is given to illustrate the effectiveness of the proposed method.
Positive Filtering with l1-Gain for Discrete-Time Positive Systems
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Xiaoming Chen
2016-01-01
Full Text Available This paper is concerned with the positive filtering problem for discrete-time positive systems under the l1-induced performance. We aim to propose a pair of positive filters with error-bounding features to estimate the output of positive systems. A novel characterization is first constructed so that the filtering error system is asymptotically stable with a prescribed l1-induced performance. Then, necessary and sufficient conditions for the existence of required filters are presented, and the obtained results are expressed as linear programming problems. Moreover, it is pointed out that the results can be easily checked by standard software. In addition, a numerical example is given to show the effectiveness of the proposed design procedures.
Institute of Scientific and Technical Information of China (English)
Shuo Zhang,Yan Zhao,Min Li,; Jianhui Zhao
2015-01-01
The global y optimal recursive filtering problem is stu-died for a class of systems with random parameter matrices, stochastic nonlinearities, correlated noises and missing measure-ments. The stochastic nonlinearities are presented in the system model to reflect multiplicative random disturbances, and the addi-tive noises, process noise and measurement noise, are assumed to be one-step autocorrelated as wel as two-step cross-correlated. A series of random variables is introduced as the missing rates governing the intermittent measurement losses caused by un-favorable network conditions. The aim of the addressed filtering problem is to design an optimal recursive filter for the uncertain systems based on an innovation approach such that the filtering error is global y minimized at each sampling time. A numerical simulation example is provided to il ustrate the effectiveness and applicability of the proposed algorithm.
Enhanced H∞ Filtering for Continuous-time State-delayed Systems
Institute of Scientific and Technical Information of China (English)
Ying Zhang; Ai-Guo Wu; Guang-Ren Duan
2009-01-01
The H∞ filtering problem for continuous-time polytopic uncertain time-delay systems is investigated. Attention is focused on the design of full-order filters guaranteeing a prescribed H∞ attenuation level for the filtering error system. First, a simple alternative proof is given for an improved linear matrix inequality (LMI) representation of H∞ performance. Then, based on the performance criterion which kecps Lyapunov matrices out of the product of system dynamic matrices, a sufficient condition for the existence of robust estimators is formulated in terms of LMIs, and the corresponding filter design is cast into a convcx optimization problem which can be efficiently handled by using standard numerical algorithms. It is shown that the proposed design strategy allows the use of parameter-dependent Lyapunov functions and hence it is less conservative than some earlier results. A numerical example is employed to demonstrate the feasibility and advantage of the proposed design.
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.
Yao, Yuhan; Liu, He; Wu, Wei
2015-07-18
High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.
Defect Detection of Velvet Bathrobe Fabrics and Grading with Demerit Point Systems
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Deniz Mutlu Ala
2015-12-01
Full Text Available Fabric defects that may occur at different stages of woven terry fabric production requires quality control and classification of fabrics as first or second grade before sending to customer. In this study, before shipping of two different terry fabric orders, defects were detected by inspection of fabric rolls on a lighted control board by experienced experts. Number of the defects and dimensions of the defects seen during the inspection were noted on quality control charts. Detected defects were defined and scored according to different demerit point systems. In this way, the fabric rolls were classified according to the demerit point systems before being shipped to garment enterprises. Disputes can be avoided with classification made by a demerit point system on which manufacturer and the customer have agreed.
Carbon material based microelectromechanical system (MEMS): Fabrication and devices
Xu, Wenjun
silicon and metal based microsystems. In this thesis, this mature technique was exploited to generate a variety of microelectrode structures to facilitate the micropatterning and manipulation of the CNTs. Selective deposition of electrically charged CNTs onto desired locations was realized in an EPD process through patterning of electric field lines created by the microelectrodes fabricated through MEMS techniques. A variety of 2-D and 3-D micropatterns of CNTs with waferscale areas have been successfully achieved in both rigid and elastic systems. The thickness and morphology of the generated CNT patterns was found to be readily controllable through the parameters of the fabrication process. Studies also showed that for this technique, high surface hydrophobicity of the non-conductive regions in microstructures was critical to accomplish well-defined selective micropatterning of CNTs. Upon clearing the hurdles of the CNT manipulation, a patterned PDMS/CNT nanocomposite was fabricated through the aforementioned approach and was incorporated, investigated and validated in elastic force/strain microsensors. The gauge factor of the sensor exhibited a strong dependence on both the initial resistance of the device and the applied strain. Detailed analysis of the data suggests that the piezoresistive effect of this specially constructed bi-layer composite could be due to three mechanisms, and the sensing mechanism may vary when physical properties of the CNT network embedded in the polymer matrix alter. The feasibility of the PDSM/CNT composite being utilized as an elastic electret was further explored. The nanocomposite composed of these two non-traditional electret materials exhibited electret characteristics with reasonable charge storage stability when charged using a corona discharge. The power generation capacity of the corona-charged composite has been characterized and successfully demonstrated in both a ball drop experiment and cyclic mechanical load experiments
Fabrication and Characterization of Copper System Compound Semiconductor Solar Cells
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Ryosuke Motoyoshi
2010-01-01
Full Text Available Copper system compound semiconductor solar cells were produced by a spin-coating method, and their cell performance and structures were investigated. Copper indium disulfide- (CIS- based solar cells with titanium dioxide (TiO2 were produced on F-doped SnO2 (FTO. A device based on an FTO/CIS/TiO2 structure provided better cell performance compared to that based on FTO/TiO2/CIS structure. Cupric oxide- (CuO- and cuprous oxide- (Cu2O- based solar cells with fullerene (C60 were also fabricated on FTO and indium tin oxide (ITO. The microstructure and cell performance of the CuO/C60 heterojunction and the Cu2O:C60 bulk heterojunction structure were investigated. The photovoltaic devices based on FTO/CuO/C60 and ITO/Cu2O:C60 structures provided short-circuit current density of 0.015 mAcm−2 and 0.11 mAcm−2, and open-circuit voltage of 0.045 V and 0.17 V under an Air Mass 1.5 illumination, respectively. The microstructures of the active layers were examined by X-ray diffraction and transmission electron microscopy.
Systems and methods for scalable perovskite device fabrication
Energy Technology Data Exchange (ETDEWEB)
Huang, Jinsong; Dong, Qingfeng; Sao, Yuchuan
2017-02-28
Continuous processes for fabricating a perovskite device are described that include using a doctor blade for continuously forming a perovskite layer and using a conductive tape lamination process to form an anode or a cathode layer on the perovskite device.
Design and Simulation of a T-Type Lymphocyte Cells Filter on a Microfluidic System
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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 %.
Energy Technology Data Exchange (ETDEWEB)
Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reeves, Kirk Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-02-24
Two LANL FTS (Filter Test System ) devices for nuclear material storage canisters are fully operational. One is located in PF-4 ( i.e. the TA-55 FTS) while the other is located at the Radiation Protection Division’s Aerosol Engineering Facility ( i.e. the TA-3 FTS). The systems are functionally equivalent , with the TA-3 FTS being the test-bed for new additions and for resolving any issues found in the TA-55 FTS. There is currently one unresolved issue regarding the TA-55 FTS device. The canister lid clamp does not give a leak tight seal when testing the 1 QT (quart) or 2 QT SAVY lids. An adapter plate is being developed that will ensure a correct test configuration when the 1 or 2 QT SAVY lid s are being tested .
A novel modular approach to active power-line harmonic filtering in distribution systems
El Shatshat, Ramadan A.
The objective of this research is to develop an efficient and reliable modular active harmonic filter system to realize a cost-effective solution to the harmonic problem. The proposed filter system consists of a number CSC modules, each dedicated to filter a specific harmonic of choice (Frequency-Splitting Approach). The power rating of the modules will decrease and their switching frequency will increase as the order of the harmonic to be filtered is increased. The overall switching losses are minimized due to the selected harmonic elimination and balanced a "power rating"-"switching frequency" product. Two ADALINEs are proposed as a part of the filter controller for processing the signals obtained from the power-line. One ADALINE (the Current ADALINE) extracts the fundamental and harmonic components of the distorted current. The other ADALINE (the Voltage ADALINE) estimates the line voltage. The outputs of both ADALINEs are used to construct the modulating signals of the filter modules. The proposed controller decides which CSC filter module(s) is connected to the electric grid. The automated connection of the corresponding filter module(s) is based on decision-making rules in such a way that the IEEE 519-1992 limits are not violated. The information available on the magnitude of each harmonic component allows us to select the active filter bandwidth (i.e., the highest harmonic to be suppressed). This will result in more efficiency and higher performance. The proposed controller adjusts the I dc in each CSC module according to the present magnitude of the corresponding harmonic current. This results in optimum dc-side current value and minimal converter losses. The comparison of the proposed modular active filter scheme and the conventional one converter scheme on practical use in industry is presented. This comparison shows that the proposed solution is more economical, reliable and flexible compared to conventional one. High speed and accuracy of ADALINE, self
Directory of Open Access Journals (Sweden)
Jinqiu Wu
2017-01-01
Full Text Available Generalized frequency division multiplexing (GFDM is a new candidate technique for the fifth generation (5G standard based on multibranch multicarrier filter bank. Unlike OFDM, it enables the frequency and time domain multiuser scheduling and can be implemented digitally. It is the generalization of traditional OFDM with several added advantages like the low PAPR (peak to average power ratio. In this paper, the influence of the pulse shaping filter on PAPR performance of the GFDM system is investigated and the comparison of PAPR in OFDM and GFDM is also demonstrated. The PAPR is restrained by selecting proper parameters and filters to make the underwater acoustic communication more efficient.
Fault isolation filter for networked control system with event-triggered sampling scheme.
Li, Shanbin; Sauter, Dominique; Xu, Bugong
2011-01-01
In this paper, the sensor data is transmitted only when the absolute value of difference between the current sensor value and the previously transmitted one is greater than the given threshold value. Based on this send-on-delta scheme which is one of the event-triggered sampling strategies, a modified fault isolation filter for a discrete-time networked control system with multiple faults is then implemented by a particular form of the Kalman filter. The proposed fault isolation filter improves the resource utilization with graceful fault estimation performance degradation. An illustrative example is given to show the efficiency of the proposed method.
Fault Isolation Filter for Networked Control System with Event-Triggered Sampling Scheme
Directory of Open Access Journals (Sweden)
Bugong Xu
2011-01-01
Full Text Available In this paper, the sensor data is transmitted only when the absolute value of difference between the current sensor value and the previously transmitted one is greater than the given threshold value. Based on this send-on-delta scheme which is one of the event-triggered sampling strategies, a modified fault isolation filter for a discrete-time networked control system with multiple faults is then implemented by a particular form of the Kalman filter. The proposed fault isolation filter improves the resource utilization with graceful fault estimation performance degradation. An illustrative example is given to show the efficiency of the proposed method.
Neural network-based H∞ filtering for nonlinear systems with time-delays
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
A novel H∞ design methodology for a neural network-based nonlinear filtering scheme is addressed.Firstly,neural networks are employed to approximate the nonlinearities.Next,the nonlinear dynamic system is represented by the mode-dependent linear difference inclusion (LDI).Finally,based on the LDI model,a neural network-based nonlinear filter (NNBNF) is developed to minimize the upper bound of H∞ gain index of the estimation error under some linear matrix inequality (LMI) constraints.Compared with the existing nonlinear filters,NNBNF is time-invariant and numerically tractable.The validity and applicability of the proposed approach are successfully demonstrated in an illustrative example.
Energy Technology Data Exchange (ETDEWEB)
Bordoni, L. [ENEA Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy). Funzione Centrale Studi
1999-07-01
In this report the architecture of an information filtering system for world wide web, developed by the Rome Third University (Italy) for ENEA (National Agency for New Technology, Energy and the Environment), is described. This prototype allows for selecting documents in text/HTML format from the web according to the interests of users. A user modeling shell allows ro build a model of user's interests, obtained during the interaction. The experimental results support the choice of embedding methods for this kind of application. [Italian] In questo rapporto viene descritta l'architettura di un sistema adattivo di information filtering su world wide web, sviluppato dall'universita' di Roma III in collaborazione con l'ENEA. Il prototipo descritto e' in grado di selezionare documenti in formato testo/html, raccolti dal web, in accordo con le caratteristiche e gli interessi degli utenti. Una shell di modellazione utente consente di costruire un modello degli interessi dell'utente, ottenuto nel corso dell'interazione. I risultati sperimentali rafforzano la scelta di usare metodi di modellazione utente per questo genere di applicazioni.
Directory of Open Access Journals (Sweden)
Túlio Assunção Pires Ribeiro
2004-04-01
Full Text Available Obstruction of emitters caused by the presence of solid particles in the water raises the cost and maintenance of trickle irrigation systems, and might compromise their utilization. This research was performed through test fields, with the objective of evaluating the performance of a disc filter (130 microns and a non woven synthetic fabric filter on the removal of physical, chemical and biological impurities from the irrigation water, which may cause emitter obstruction during fertirrigation processes. The evaluation criteria of the impurities present in the irrigation water, were based on studies performed on trickle irrigation systems. Specifically, physical, chemical and biological parameters analyzed in the inflow and outflow water from both filters were: pH, turbidity, total suspended solids, salinity, total iron, sulphites, manganese, algae and bacteria. Results pointed to chemical factors, which presented medium clogging risks to the emitters; those factors were: pH, total iron and sulphite concentration. All the other parameters of water quality did not present clogging risks. A comparative analysis of head loss evolution, according to the filtered volume, was also atempted Non woven synthetic fabric filter presented a higher evolution when compared to the disc filter.Um dos fatores que elevam os custos de operação e manutenção dos sistemas de irrigação localizada e, em certos casos, inviabiliza a utilização desse método, é a obstrução de emissores pela presença de partículas sólidas na água de irrigação. O presente trabalho teve por objetivo principal estimar, através de ensaios experimentais de campo, o desempenho de um filtro de disco (130 microns com outro de manta sintética não tecida na remoção de impurezas de origens físicas, químicas e biológicas presentes na água de irrigação que promovem o entupimento dos emissores, quando se utiliza a fertirrigação. Os critérios para avaliação das impurezas
Bloom Filter-Based Secure Data Forwarding in Large-Scale Cyber-Physical Systems
Directory of Open Access Journals (Sweden)
Siyu Lin
2015-01-01
Full Text Available Cyber-physical systems (CPSs connect with the physical world via communication networks, which significantly increases security risks of CPSs. To secure the sensitive data, secure forwarding is an essential component of CPSs. However, CPSs require high dimensional multiattribute and multilevel security requirements due to the significantly increased system scale and diversity, and hence impose high demand on the secure forwarding information query and storage. To tackle these challenges, we propose a practical secure data forwarding scheme for CPSs. Considering the limited storage capability and computational power of entities, we adopt bloom filter to store the secure forwarding information for each entity, which can achieve well balance between the storage consumption and query delay. Furthermore, a novel link-based bloom filter construction method is designed to reduce false positive rate during bloom filter construction. Finally, the effects of false positive rate on the performance of bloom filter-based secure forwarding with different routing policies are discussed.
Discrete-time filtering for nonlinear polynomial systems over linear observations
Hernandez-Gonzalez, M.; Basin, M. V.
2014-07-01
This paper designs a discrete-time filter for nonlinear polynomial systems driven by additive white Gaussian noises over linear observations. The solution is obtained by computing the time-update and measurement-update equations for the state estimate and the error covariance matrix. A closed form of this filter is obtained by expressing the conditional expectations of polynomial terms as functions of the estimate and the error covariance. As a particular case, a third-degree polynomial is considered to obtain the finite-dimensional filtering equations. Numerical simulations are performed for a third-degree polynomial system and an induction motor model. Performance of the designed filter is compared with the extended Kalman one to verify its effectiveness.
Design of H(infinity) robust fault detection filter for linear uncertain time-delay systems.
Bai, Leishi; Tian, Zuohua; Shi, Songjiao
2006-10-01
In this paper, the robust fault detection filter design problem for linear time-delay systems with both unknown inputs and parameter uncertainties is studied. Using a multiobjective optimization technique, a new performance index is introduced, which takes into account the robustness of the fault detection filter against disturbances and sensitivity to faults simultaneously. The reference residual model is then designed based on this performance index to formulate the robust fault detection filter design problem as an H(infinity) model-matching problem. By applying robust H(infinity) optimization control technique, the existence condition of the robust fault detection filter for linear time-delay systems with both unknown inputs and parameter uncertainties is presented in terms of linear matrix inequality formulation, independently of time delay. In order to detect the fault, an adaptive threshold which depends on the inputs is finally determined. An illustrative design example is used to demonstrate the validity of the proposed approach.
Robust Filtering for a Class of Networked Nonlinear Systems With Switching Communication Channels.
Zhang, Lixian; Yin, Xunyuan; Ning, Zepeng; Ye, Dong
2016-02-15
This paper is concerned with the problem of robust filter design for a class of discrete-time networked nonlinear systems. The Takagi-Sugeno fuzzy model is employed to represent the underlying nonlinear dynamics. A multi-channel communication scheme that involves a channel switching phenomenon described by a Markov chain is proposed for data transmission. Two typical communication imperfections, network-induced time-varying delays and packet dropouts are considered in each channel. The objective of this paper is to design an admissible filter such that the filter error system is stochastically stable and ensures a prescribed disturbance attenuation level bound. Based on the Lyapunov-Krasovskii functional method and matrix inequality techniques, sufficient conditions on the existence of the desired filter are obtained. A numerical example is provided to illustrate the effectiveness of the proposed design approach.
Robust Fusion Filtering for Multisensor Time-Varying Uncertain Systems: The Finite Horizon Case
Directory of Open Access Journals (Sweden)
Xiaoliang Feng
2016-01-01
Full Text Available The robust H∞ fusion filtering problem is considered for linear time-varying uncertain systems observed by multiple sensors. A performance index function for this problem is defined as an indefinite quadratic inequality which is solved by the projection method in Krein space. On this basis, a robust centralized finite horizon H∞ fusion filtering algorithm is proposed. However, this centralized fusion method is with poor real time property, as the number of sensors increases. To resolve this difficulty, within the sequential fusion framework, the performance index function is described as a set of quadratic inequalities including an indefinite quadratic inequality. And a sequential robust finite horizon H∞ fusion filtering algorithm is given by solving this quadratic inequality group. Finally, two simulation examples for time-varying/time-invariant multisensor systems are exploited to demonstrate the effectiveness of the proposed methods in the respect of the real time property and filtering accuracy.
A New Starting Method of the Hybrid Power Filter for Wind Power Generation Systems with Soft Starter
Yamada, Hiroaki; Hiraki, Eiji; Tanaka, Toshihiko
This paper proposes a new method of starting the hybrid power filter for wind power generation systems with soft starter. In the proposed method, an active filter of the hybrid power filter behaves a resistor for the source current under the starting condition. Thus the inrush phenomena of the passive filter are perfectly suppressed. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush currents for the passive filter, building up the dc voltage of the active filter.
A new Recommender system based on target tracking: a Kalman Filter approach
Nowakowski, Samuel; Boyer, Anne
2010-01-01
In this paper, we propose a new approach for recommender systems based on target tracking by Kalman filtering. We assume that users and their seen resources are vectors in the multidimensional space of the categories of the resources. Knowing this space, we propose an algorithm based on a Kalman filter to track users and to predict the best prediction of their future position in the recommendation space.
Target tracking in the recommender space: Toward a new recommender system based on Kalman filtering
Nowakowski, Samuel; Boyer, Anne
2010-01-01
In this paper, we propose a new approach for recommender systems based on target tracking by Kalman filtering. We assume that users and their seen resources are vectors in the multidimensional space of the categories of the resources. Knowing this space, we propose an algorithm based on a Kalman filter to track users and to predict the best prediction of their future position in the recommendation space.
A Web-Based Integrated Intelligent System for Sensory Fabric Hand Evaluation
Institute of Scientific and Technical Information of China (English)
DING Yong-sheng(丁永生); YU Run-xian(余润仙); SUN Fei(孙霏); HOU Cai-hong(侯彩虹); ZENG Xian-yi(曾宪奕); CUI Yun-hua(崔运花); Ludovic Koehl
2004-01-01
This paper presents a web-based integrated system for on-line sensory fabric hand evaluation. The methods of fuzzy techniques, neural networks, classical factorial analysis and other data analysis are used in the system to analyze the objective and subjective data, and to build the relationship between them. Given the objective data of a new fabric sample, the system can provide its sensory hand data and its total hand grade. In meantime, the total hand grade can be obtained directly from the sensory fabric hand data if provided. The sensory evaluation system is developed in Internet environment using Java language and SQL server database management system.
Design and Simulation of the Integrated Navigation System based on Extended Kalman Filter
Directory of Open Access Journals (Sweden)
Zhou Weidong
2017-04-01
Full Text Available The integrated navigation system is used to estimate the position, velocity, and attitude of a vehicle with the output of inertial sensors. This paper concentrates on the problem of the INS/GPS integrated navigation system design and simulation. The structure of the INS/GPS integrated navigation system is made up of four parts: 1 GPS receiver, 2 Inertial Navigation System, 3 Extended Kalman filter, and 4 Integrated navigation scheme. Afterwards, we illustrate how to simulate the integrated navigation system with the extended Kalman filter by measuring position, velocity and attitude. Particularly, the extended Kalman filter can estimate states of the nonlinear system in the noisy environment. In extended Kalman filter, the estimation of the state vector and the error covariance matrix are computed by steps: 1 time update and 2 measurement update. Finally, the simulation process is implemented by Matlab, and simulation results prove that the error rate of statement measuring is lower when applying the extended Kalman filter in the INS/GPS integrated navigation system.
Filter Mounting and Mechanism Design for the Pan-STARRS PS1 Prototype Telescope System
Ryan, A.; Morgan, J.; Siegmund, W.; Hude, C.
The Pan-STARRS PS1 telescope is a 1.8m Cassegrain telescope with a 7 square degree field of view and a 1.4 billion pixel CCD camera. The required clear aperture at the filters is 496mm in diameter, and therefore the filters needed are quite large. The Pan-STARRS filter complement consists of six octagonal shaped filters that have a distance between the flats of 538mm and a thickness of 10mm. The automated mechanism that will move the filters needs to fit into a small area. A filter wheel would be prohibitively large, so the mechanism will consist of three layers with two athermally mounted filters that slide on each layer. Each layer will be identical to the other two to provide interchangeability and commonality in manufacturing. The layers will be stacked and held together with top and bottom cover plates to form a rigid structure. The shutter will be mounted to the bottom of the mechanism and they will be installed as one unit. A separate structure will be utilized to clamp the mechanism to the telescope cassegrain core registration points. This installation system will allow the mechanism to be isolated from other structural loads and be easily removed without affecting the camera. This talk will present the detailed design of the mechanism an its performance to date.
From Filaments to Fabric Packs - Simulating the Performance of Textile Protection Systems
2006-11-01
subsequently assembled in some repeating (or, in the case of nonwoven textiles - random) format, defining the continuum perspective at which to model the...fabric construction and surface finish. It’s quite possible that the performance of fabric based body armor or fabric reinforced composite armor could...deniers; at the ply level, by layering with different weaves, nonwovens and/or other materials. Hybridized systems of Kevlar and high molecular
Computer Assisted Designing System for Hands and Formability of Worsted Fabrics
Institute of Scientific and Technical Information of China (English)
王府梅; 徐广标; 林洪芹
2004-01-01
Equations that can predict worsted fabrics' properties such as bending, shearing, compression, surface and tension, were achieved by means of theoretical and experimental studies. By combining these equations with Kawabata's hand and silhouette evaluation methods, a software system was established. Then the mechanical properties, hand and silhouette of a fabric can be predicted quickly and accurately in terms of fiber configurations, yarn and fabric structures. The predictive result if unsatisfied can be revised by the function of "Help for designing modification".
Digital controller for hybrid filter in HVDC based on approximate inverse system
Institute of Scientific and Technical Information of China (English)
SU Ling; ZHAO Dong-yuan; CHEN Jian-ye; WANG Zan-ji
2006-01-01
In order to eliminate the characteristic harmonics in high voltage direct current (HVDC) transmission systems and to simplify the analog controller structure,this paper proposes a new digital controller by adopting an approximate inverse system control strategy according to the frequency response characteristic of the hybrid power filter.The proposed digital controller is implemented with a TMS320C32 DSP,including a series of parallel digital band-pass filters,phase shifters and amplifiers.The results of both simulations based on PSCAD and experiments on a 30 kVA HVDC system prove that the proposed digital control system is stable and efficient for eliminating the harmonics.
Command Filtering-Based Fuzzy Control for Nonlinear Systems With Saturation Input.
Yu, Jinpeng; Shi, Peng; Dong, Wenjie; Lin, Chong
2016-12-13
In this paper, command filtering-based fuzzy control is designed for uncertain multi-input multioutput (MIMO) nonlinear systems with saturation nonlinearity input. First, the command filtering method is employed to deal with the explosion of complexity caused by the derivative of virtual controllers. Then, fuzzy logic systems are utilized to approximate the nonlinear functions of MIMO systems. Furthermore, error compensation mechanism is introduced to overcome the drawback of the dynamics surface approach. The developed method will guarantee all signals of the systems are bounded. The effectiveness and advantages of the theoretic result are obtained by a simulation example.
Time-dependent switched discrete-time linear systems control and filtering
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 H-Infinity Filtering for Networked Control Systems with Markovian Jumps and Packet Dropouts
Directory of Open Access Journals (Sweden)
Fangwen Li
2014-07-01
Full Text Available This paper deals with the H-Infinity filtering problem for uncertain networked control systems. In the study, network-induced delays, limited communication capacity due to signal quantization and packet dropout are all taken into consideration. The finite distributed delays with probability of occurrence in a random way is introduced in the network.The packet dropout is described by a Bernoulli process. The system is modeled as Markovian jumps system with partially known transition probabilities. A full-order filter is designed to estimate the system state. By linear inequality approach, a sufficient condition is derived for the resulting filtering error system to be mean square stable with a prescribed H-Infinity performance level. Finally, a numerical example is given to illustrate the effectiveness and efficiency of the proposed design method.
Online digital filter and QRS detector applicable in low resource ECG monitoring systems.
Tabakov, Serafim; Iliev, Ivo; Krasteva, Vessela
2008-11-01
The present work describes fast computation methods for real-time digital filtration and QRS detection, both applicable in autonomous personal ECG systems for long-term monitoring. Since such devices work under considerable artifacts of intensive body and electrode movements, the input filtering should provide high-quality ECG signals supporting the accurate ECG interpretation. In this respect, we propose a combined high-pass and power-line interference rejection filter, introducing the simple principle of averaging of samples with a predefined distance between them. In our implementation (sampling frequency of 250 Hz), we applied averaging over 17 samples distanced by 10 samples (Filter10x17), thus realizing a comb filter with a zero at 50 Hz and high-pass cut-off at 1.1 Hz. Filter10x17 affords very fast filtering procedure at the price of minimal computing resources. Another benefit concerns the small ECG distortions introduced by the filter, providing its powerful application in the preprocessing module of diagnostic systems analyzing the ECG morphology. Filter10x17 does not attenuate the QRS amplitude, or introduce significant ST-segment elevation/depression. The filter output produces a constant error, leading to uniform shifting of the entire P-QRS-T segment toward about 5% of the R-peak amplitude. Tests with standardized ECG signals proved that Filter10x17 is capable to remove very strong baseline wanderings, and to fully suppress 50 Hz interferences. By changing the number of the averaged samples and the distance between them, a filter design with different cut-off and zero frequency could be easily achieved. The real-time QRS detector is designed with simplified computations over single channel, low-resolution ECGs. It relies on simple evaluations of amplitudes and slopes, including history of their mean values estimated over the preceding beats, smart adjustable thresholds, as well as linear logical rules for identification of the R-peaks in real
Enhanced Userspace and In-Kernel Trace Filtering for Production Systems
Institute of Scientific and Technical Information of China (English)
Suchakrapani Datt Sharma; Michel Dagenais
2016-01-01
Trace tools like LTTng have a very low impact on the traced software as compared with traditional debuggers. However, for long runs, in resource constrained and high throughput environments, such as embedded network switching nodes and production servers, the collective tracing impact on the target software adds up considerably. The overhead is not just in terms of execution time but also in terms of the huge amount of data to be stored, processed and analyzed oﬄine. This paper presents a novel way of dealing with such huge trace data generation by introducing a Just-In-Time (JIT) filter based tracing system, for sieving through the flood of high frequency events, and recording only those that are relevant, when a specific condition is met. With a tiny filtering cost, the user can filter out most events and focus only on the events of interest. We show that in certain scenarios, the JIT compiled filters prove to be three times more effective than similar interpreted filters. We also show that with the increasing number of filter predicates and context variables, the benefits of JIT compilation increase with some JIT compiled filters being even three times faster than their interpreted counterparts. We further present a new architecture, using our filtering system, which can enable co-operative tracing between kernel and process tracing VMs (virtual machines) that share data eﬃciently. We demonstrate its use through a tracing scenario where the user can dynamically specify syscall latency through the userspace tracing VM whose effect is reflected in tracing decisions made by the kernel tracing VM. We compare the data access performance on our shared memory system and show an almost 100 times improvement over traditional data sharing for co-operative tracing.
Ren, Hongwu; Dekany, Richard; Britton, Matthew
2005-05-01
We propose a new recursive filtering algorithm for wave-front reconstruction in a large-scale adaptive optics system. An embedding step is used in this recursive filtering algorithm to permit fast methods to be used for wave-front reconstruction on an annular aperture. This embedding step can be used alone with a direct residual error updating procedure or used with the preconditioned conjugate-gradient method as a preconditioning step. We derive the Hudgin and Fried filters for spectral-domain filtering, using the eigenvalue decomposition method. Using Monte Carlo simulations, we compare the performance of discrete Fourier transform domain filtering, discrete cosine transform domain filtering, multigrid, and alternative-direction-implicit methods in the embedding step of the recursive filtering algorithm. We also simulate the performance of this recursive filtering in a closed-loop adaptive optics system.
New polymorphous computing fabric.
Energy Technology Data Exchange (ETDEWEB)
Wolinski, C. (Christophe); Gokhale, M. (Maya); McCabe, K. P. (Kevin P.)
2002-01-01
This paper introduces a new polymorphous computing Fabric well suited to DSP and Image Processing and describes its implementation on a Configurable System on a Chip (CSOC). The architecture is highly parameterized and enables customization of the synthesized Fabric to achieve high performance for a specific class of application. For this reason it can be considered to be a generic model for hardware accelerator synthesis from a high level specification. Another important innovation is the Fabric uses a global memory concept, which gives the host processor random access to all the variables and instructions on the Fabric. The Fabric supports different computing models including MIMD, SPMD and systolic flow and permits dynamic reconfiguration. We present a specific implementation of a bank of FIR filters on a Fabric composed of 52 cells on the Altera Excalibur ARM running at 33 MHz. The theoretical performance of this Fabric is 1.8 GMACh. For the FIR application we obtain 1.6 GMAC/s real performance. Some automatic tools have been developed like the tool to provide a host access utility and assembler.
Kaag, N.H.B.M.; Sneekes, A.C.
2015-01-01
The BIO-SEA® Ballast Water Treatment System (BWTS) was tested at the IMARES land-based test facility. General goal of the tests was to compare two different brands of filter and to test the filter efficiency of finer mesh sizes of each brand. The filters were tested in combination with a ‘one-shot U
Magdich, L. N.; Yushkov, K. B.; Voloshinov, V. B.
2009-04-01
Light diffraction is studied in two tandem acousto-optic cells filtering unpolarised radiation with a wide angular spectrum. It is shown that the side lobes of the ultrasonic radiation pattern of a piezoelectric transducer produce side diffraction intensity maxima at the output of the system consisting of two filters. Diffraction in paratellurite filters is studied experimentally at 1.06 μm.
Joint Linear Filter Design in Multiuser Cooperative Nonregenerative MIMO Relay Systems
Directory of Open Access Journals (Sweden)
Li Gen
2009-01-01
Full Text Available This paper addresses the filter design issues for multiuser cooperative nonregenerative MIMO relay systems in both downlink and uplink scenarios. Based on the formulated signal model, the filter matrix optimization is first performed for direct path and relay path respectively, aiming to minimize the mean squared error (MSE. To be more specific, for the relay path, we derive the local optimal filter scheme at the base station and the relay station jointly in the downlink scenario along with a more practical suboptimal scheme, and then a closed-form joint local optimal solution in the uplink scenario is exploited. Furthermore, the optimal filter for the direct path is also presented by using the exiting results of conventional MIMO link. After that, several schemes are proposed for cooperative scenario to combine the signals from both paths. Numerical results show that the proposed schemes can reduce the bit error rate (BER significantly.
New approaches to robust l2-l∞ and H∞ filtering for uncertain discrete-time systems
Institute of Scientific and Technical Information of China (English)
高会军; 王常虹
2003-01-01
The problems of robust l2-l∞ and H∞ filtering for discrete-time systems with parameter uncer- tainty residing in a polytope are investigated in this paper. The filtering strategies are based on new ro- bust performance criteria derived from a new result of parameter-dependent Lyapunov stability condition, which exhibit less conservativeness than previous results in the quadratic framework. The designed filters guaranteeing a prescribed l2-l∞ or H∞ noise attenuation level can be obtained from the solution of convex optimization problems, which can be solved via efficient interior point methods. Numerical examples have shown that the filter design procedures proposed in this paper are much less conservative than earlier results.
Identification of linear continuous-time system using wavelet modulating filters
Institute of Scientific and Technical Information of China (English)
贺尚红; 钟掘
2004-01-01
An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filters have been analyzed. Using linear modulating filters, we can obtain an identification model that is parameterized directly in continuous-time model parameters. By applying the results from discrete-time model identification to the obtained identification model, a continuous-time estimation method is developed. Considering the accuracy of parameter estimates, an instrumental variable(V) method is proposed, and the design of modulating integral filter is discussed. The relationship between the accuracy of identification and the parameter of modulating filter is investigated, and some points about designing Gaussian wavelet modulating function are outlined. Finally, a simulation study is also included to verify the theoretical results.
GORE Flow Reversal System and GORE Embolic Filter Extension Study
2016-01-22
Carotid Stenosis; Constriction, Pathologic; Carotid Artery Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Arterial Occlusive Diseases; Vascular Diseases; Cardiovascular Diseases; Pathological Conditions, Anatomical
Directory of Open Access Journals (Sweden)
Michael Basin
2011-04-01
Full Text Available In this paper, the mean-square filtering problem for polynomial system states confused with white Poisson noises over polynomial observations is studied proceeding from the general expression for the stochastic Ito differentials of the mean-square estimate and the error variance. In contrast to the previously obtained results, the paper deals with the general case of nonlinear polynomial states and observations with white Poisson noises. As a result, the Ito differentials for the mean-square estimate and error variance corresponding to the stated filtering problem are first derived. The procedure for obtaining an approximate closed-form finite-dimensional system of the filtering equations for any polynomial state over observations with any polynomial drift is then established. In the example, the obtained closed-form filter is applied to solve the third order sensor filtering problem for a quadratic state, assuming a conditionally Poisson initial condition for the extended third order state vector. The simulation results show that the designed filter yields a reliable and rapidly converging estimate.
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.
Spectrum splitting metrics and effect of filter characteristics on photovoltaic system performance.
Russo, Juan M; Zhang, Deming; Gordon, Michael; Vorndran, Shelby; Wu, Yuechen; Kostuk, Raymond K
2014-03-10
During the past few years there has been a significant interest in spectrum splitting systems to increase the overall efficiency of photovoltaic solar energy systems. However, methods for comparing the performance of spectrum splitting systems and the effects of optical spectral filter design on system performance are not well developed. This paper addresses these two areas. The system conversion efficiency is examined in detail and the role of optical spectral filters with respect to the efficiency is developed. A new metric termed the Improvement over Best Bandgap is defined which expresses the efficiency gain of the spectrum splitting system with respect to a similar system that contains the highest constituent single bandgap photovoltaic cell. This parameter indicates the benefit of using the more complex spectrum splitting system with respect to a single bandgap photovoltaic system. Metrics are also provided to assess the performance of experimental spectral filters in different spectrum splitting configurations. The paper concludes by using the methodology to evaluate spectrum splitting systems with different filter configurations and indicates the overall efficiency improvement that is possible with ideal and experimental designs.
Finite-time H∞ filtering for non-linear stochastic systems
Hou, Mingzhe; Deng, Zongquan; Duan, Guangren
2016-09-01
This paper describes the robust H∞ filtering analysis and the synthesis of general non-linear stochastic systems with finite settling time. We assume that the system dynamic is modelled by Itô-type stochastic differential equations of which the state and the measurement are corrupted by state-dependent noises and exogenous disturbances. A sufficient condition for non-linear stochastic systems to have the finite-time H∞ performance with gain less than or equal to a prescribed positive number is established in terms of a certain Hamilton-Jacobi inequality. Based on this result, the existence of a finite-time H∞ filter is given for the general non-linear stochastic system by a second-order non-linear partial differential inequality, and the filter can be obtained by solving this inequality. The effectiveness of the obtained result is illustrated by a numerical example.
Parallel power electronics filters in three-phase four-wire systems principle, control and design
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. .
Adaptive filter for a miniature MEMS based attitude and heading reference system
Institute of Scientific and Technical Information of China (English)
WANG Mei; WANG Yong-quan; ZHANG Yan-hua
2006-01-01
An extended Kalman filter with adaptive gain was used to build a miniature attitude and heading reference system based on a stochastic model. The adaptive filter has six states with a time variable transition matrix. When the system is in the non-acceleration mode, the accelerometer measurements of the gravity and the compass measurements of the heading have observability and yield good estimates of the states. When the system is in the high dynamic mode and the bias has converged to an accurate estimate, the attitude calculation will be maintained for a long interval of time. The adaptive filter tunes its gain automatically based on the system dynamics sensed by the accelerometers to yield optimal performance.
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
is demonstrated on a T/4 Delay Phase Locked Loop (PLL) system for a single-phase grid-connected inverter. The T/4 Delay PLL requires to cascade 50 unit delays when implemented (for a 50-Hz system with 10 kHz sampling frequency). Furthermore, digital frequency adaptive comb filters are adopted to enhance...... the performance of the T/4 Delay PLL when the grid suffers from harmonics. Experimental results have confirmed the effectiveness of the digital filters for advanced control systems....
Directory of Open Access Journals (Sweden)
Jingjing Wu
2015-01-01
Full Text Available A robust particle filter (PF and its application to fault/defect detection of nonlinear system are investigated in this paper. First, an adaptive parametric model is exploited as the observation model for a nonlinear system. Second, by incorporating the parametric model, particle filter is employed to estimate more accurate hidden states for the nonlinear stochastic system. Third, by formulating the problem of defect detection within the hypothesis testing framework, the statistical properties of the proposed testing are established. Finally, experimental results demonstrate the effectiveness and robustness of the proposed detector on real defect detection and localization in images.
Institute of Scientific and Technical Information of China (English)
Xuehua Ye; Yaoju Zhang; Junfeng Chen
2007-01-01
In solid immersion lens (SIL) microscopy systems with high numerical aperture (NA), there always exists the aberration produced by Fresnel effects at the interface between SIL and the sample. This aberration may cause the degradation of the image of sample. We design a continuous phase filter and optimize the optical field distribution of SIL system. The numerical results show that when the continuous phase filter is used, the field distribution of SIL system can be optimized, and the focal depth and intensity of transmitted light can be increased. At the same time, the intensity of side-lobe and the resolution are kept almost unchanged.
Blind speech separation system for humanoid robot with FastICA for audio filtering and separation
Budiharto, Widodo; Santoso Gunawan, Alexander Agung
2016-07-01
Nowadays, there are many developments in building intelligent humanoid robot, mainly in order to handle voice and image. In this research, we propose blind speech separation system using FastICA for audio filtering and separation that can be used in education or entertainment. Our main problem is to separate the multi speech sources and also to filter irrelevant noises. After speech separation step, the results will be integrated with our previous speech and face recognition system which is based on Bioloid GP robot and Raspberry Pi 2 as controller. The experimental results show the accuracy of our blind speech separation system is about 88% in command and query recognition cases.
Jakob Müller-Systems and Solutions for Narrow Fabrics
Institute of Scientific and Technical Information of China (English)
Wang Ting
2010-01-01
@@ Founded in Switzerland in 1887,Jakob Müller AG is one of the world leaders in technology for the manufacture of woven and knitted tapes and webbing,woven labels,technical textiles,woven ropes,printed narrow fabrics,dyeing,make-up and winding machinery.
Caselli, Derek; Liu, Zhicheng; Shelhammer, David; Ning, Cun-Zheng
2014-10-08
Nanomaterials such as semiconductor nanowires have unique features that could enable novel optoelectronic applications such as novel solar cells. This paper aims to demonstrate one such recently proposed concept: Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells for spectrum-splitting photovoltaic systems. Two cells with different band gaps were fabricated simultaneously in the same process on a single substrate using spatially composition-graded CdSSe alloy nanowires grown by the Dual-Gradient Method in a chemical vapor deposition system. CdSSe nanowire ensemble devices tested under 1 sun AM1.5G illumination achieved open-circuit voltages up to 307 and 173 mV and short-circuit current densities as high as 0.091 and 0.974 mA/cm(2) for the CdS- and CdSe-rich cells, respectively. The open-circuit voltages were roughly three times those of similar CdSSe film cells fabricated for comparison due to the superior optical quality of the nanowires. I-V measurements were also performed using optical filters to simulate spectrum-splitting. The open-circuit voltages and fill factors of the CdS-rich subcells were uniformly larger than the corresponding CdSe-rich cells for similar photon flux, as expected. This suggests that if all wires can be contacted, the wide-gap cell is expected to have greater output power than the narrow-gap cell, which is the key to achieving high efficiencies with spectrum-splitting. This paper thus provides the first proof-of-concept demonstration of simultaneous fabrication of MILAMB solar cells. This approach to solar cell fabrication using single-crystal nanowires for spectrum-splitting photovoltaics could provide a future low-cost high-efficiency alternative to the conventional high-cost high-efficiency tandem cells.
Collaborating Filtering Community Image Recommendation System Based on Scene
Directory of Open Access Journals (Sweden)
He Tao
2017-01-01
Full Text Available With the advancement of smart city, the development of intelligent mobile terminal and wireless network, the traditional text information service no longer meet the needs of the community residents, community image service appeared as a new media service. “There are pictures of the truth” has become a community residents to understand and master the new dynamic community, image information service has become a new information service. However, there are two major problems in image information service. Firstly, the underlying eigenvalues extracted by current image feature extraction techniques are difficult for users to understand, and there is a semantic gap between the image content itself and the user’s understanding; secondly, in community life of the image data increasing quickly, it is difficult to find their own interested image data. Aiming at the two problems, this paper proposes a unified image semantic scene model to express the image content. On this basis, a collaborative filtering recommendation model of fusion scene semantics is proposed. In the recommendation model, a comprehensiveness and accuracy user interest model is proposed to improve the recommendation quality. The results of the present study have achieved good results in the pilot cities of Wenzhou and Yan'an, and it is applied normally.
Sekiya, N.
2016-08-01
We have developed two high-order high-temperature superconducting (HTS) dual-band bandpass filters (BPFs) with a receiver subsystem for future mobile communication systems. They feature stub-loaded hair-pin resonators with two types of microstrip lines between them. One has a six-pole design, and the other has an eight-pole design. Both were designed to operate at 2.15 GHz with a 43-MHz (2%) bandwidth for the lower passband and at 3.50 GHz with a 70-MHz (2%) bandwidth for the upper one. They were fabricated using YBa2Cu3Oy thin film on a CeO2-bufferd r-Al2O3 substrate. The measured results for both filters agree well with the simulated ones. The HTS dual-band BPF receiver subsystem uses a pulse tube cryocooler and a wideband low noise amplifier (LNA). We measured the frequency response of the six-pole dual-band BPF with and without a wideband LNA with a gain of 10 dB. The measured return losses were close.
ADVANCED HOT GAS FILTER DEVELOPMENT
Energy Technology Data Exchange (ETDEWEB)
E.S. Connolly; G.D. Forsythe
2000-09-30
DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests
Wang, Xudong; Syrmos, Vassilis L.
2004-07-01
In this paper, an adaptive reconfigurable control system based on extended Kalman filter approach and eigenstructure assignments is proposed. System identification is carried out using an extended Kalman filter (EKF) approach. An eigenstructure assignment (EA) technique is applied for reconfigurable feedback control law design to recover the system dynamic performance. The reconfigurable feedforward controllers are designed to achieve the steady-state tracking using input weighting approach. The proposed scheme can identify not only actuator and sensor variations, but also changes in the system structures using the extended Kalman filtering method. The overall design is robust with respect to uncertainties in the state-space matrices of the reconfigured system. To illustrate the effectiveness of the proposed reconfigurable control system design technique, an aircraft longitudinal vertical takeoff and landing (VTOL) control system is used to demonstrate the reconfiguration procedure.
Feng, De-zhen; Yu, Qi-qi
2017-01-01
Domestic water treatment is a very important technology field. Now, mechanical water treatment technology is getting wide use in production. In the process of life water treatment, filter process is a very important step. In this paper, the strength and deformation of double-deck plates filter system which includes upper filter plate, lower filter plate and reinforced ribs were analyzed with ANSYS and useful results were got. Through the analysis on strength and deformation, the paper found the advantages and disadvantages of production and design of filter systems. After analyzing and comparing the stresses and deformations of several different design schemes, the paper provided the optimized design plan of filter system which can satisfy the strength need and decrease the creep deformation of plastic filter plates.
1989-10-30
In this Phase I SBIR study, new methods are developed for the system identification and stochastic filtering of nonlinear controlled Markov processes...state space Markov process models and canonical variate analysis (CVA) for obtaining optimal nonlinear procedures for system identification and stochastic
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.
FPGA Implementation of Optimal Filtering Algorithm for TileCal ROD System
Torres, J; Castillo, V; Cuenca, C; Ferrer, A; Fullana, E; González, V; Higón, E; Poveda, J; Ruiz-Martinez, A; Salvachúa, B; Sanchis, E; Solans, C; Valero, A; Valls, J A
2008-01-01
Traditionally, Optimal Filtering Algorithm has been implemented using general purpose programmable DSP chips. Alternatively, new FPGAs provide a highly adaptable and flexible system to develop this algorithm. TileCal ROD is a multi-channel system, where similar data arrives at very high sampling rates and is subject to simultaneous tasks. It include different FPGAs with high I/O and with parallel structures that provide a benefit at a data analysis. The Optical Multiplexer Board is one of the elements presents in TileCal ROD System. It has FPGAs devices that present an ideal platform for implementing Optimal Filtering Algorithm. Actually this algorithm is performing in the DSPs included at ROD Motherboard. This work presents an alternative to implement Optimal Filtering Algorithm.
Iterative nonlinear ISI cancellation in optical tilted filter-based Nyquist 4-PAM system
Ju, Cheng; Liu, Na
2016-09-01
The conventional double sideband (DSB) modulation and direct detection scheme suffers from severer power fading, linear and nonlinear inter-symbol interference (ISI) caused by fiber dispersion and square-law direct detection. The system's frequency response deteriorates at high frequencies owing to the limited device bandwidth. Moreover, the linear and nonlinear ISI is enhanced induced by the bandwidth limited effect. In this paper, an optical tilted filter is used to mitigate the effect of power fading, and improve the high frequency response of bandwidth limited device in Nyquist 4-ary pulse amplitude modulation (4-PAM) system. Furtherly, iterative technique is introduced to mitigate the nonlinear ISI caused by the combined effects of electrical Nyquist filter, limited device bandwidth, optical tilted filter, dispersion, and square-law photo-detection. Thus, the system's frequency response is greatly improved and the delivery distance can be extended.
Recursive inversion of externally defined linear systems by FIR filters
Bach, Ralph E., Jr.; Baram, Yoram
1989-01-01
The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least-squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problem of system identification and compensation.
Depth inloop resampling using dilation filter for free viewpoint video system
Lee, Seok; Lee, Seungsin; Wey, Hocheon; Lee, Jaejoon; Park, Dusik
2013-03-01
A depth dilation filter is proposed for free viewpoint video system based on mixed resolution multi-view video plus depth (MVD). By applying gray scale dilation filter to depth images, foreground regions are extended to background region, and synthesis artifacts occur out of boundary edge. Thus, objective and subjective quality of view synthesis result is improved. A depth dilation filter is applied to inloop resampling part in encoding/decoding, and post processing part after decoding. Accurate view synthesis is important in virtual view generation for autostereoscopic display, moreover there are many coding tools which use view synthesis to reduce interview redundancy in 3D video coding such as view synthesis prediction (VSP) and depth based motion vector prediction (DMVP), and compression efficiency can be improved by accurate view synthesis. Coding and synthesis experiments are performed for performance evaluation of a dilation filter with MPEG test sequences. Dilation filter was implemented on the top of the MPEG reference software for AVC based 3D video coding. By applying a depth dilation filter, BD-rate gains of 0.5% and 6.0% in terms of PSNR of decoded views and synthesized views, respectively.
Liu, Yajuan; Park, Ju H; Guo, Bao-Zhu
2016-07-01
In this paper,the problem of H∞ filtering for a class of nonlinear discrete-time delay systems is investigated. The time delay is assumed to be belonging to a given interval, and the designed filter includes additive gain variations which are supposed to be random and satisfy the Bernoulli distribution. By the augmented Lyapunov functional approach, a sufficient condition is developed to ensure that the filtering error system is asymptotically mean-square stable with a prescribed H∞ performance. In addition, an improved result of H∞ filtering for linear system is also derived. The filter parameters are obtained by solving a set of linear matrix inequalities. For nonlinear systems, the applicability of the developed filtering result is confirmed by a longitudinal flight system, and an additional example for linear system is presented to demonstrate the less conservativeness of the proposed design method.
Real time fabric defect detection system on an embedded DSP platform
Raheja, Jagdish Lal; Ajay, Bandla; Chaudhary, Ankit
2013-11-01
In industrial fabric productions, automated real time systems are needed to find out the minor defects. It will save the cost by not transporting defected products and also would help in making compmay image of quality fabrics by sending out only undefected products. A real time fabric defect detection system (FDDS), implementd on an embedded DSP platform is presented here. Textural features of fabric image are extracted based on gray level co-occurrence matrix (GLCM). A sliding window technique is used for defect detection where window moves over the whole image computing a textural energy from the GLCM of the fabric image. The energy values are compared to a reference and the deviations beyond a threshold are reported as defects and also visually represented by a window. The implementation is carried out on a TI TMS320DM642 platform and programmed using code composer studio software. The real time output of this implementation was shown on a monitor.
High-Performance Monitoring Architecture for Large-Scale Distributed Systems Using Event Filtering
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
Nanophotonic filters for digital imaging
Walls, Kirsty
There has been an increasing demand for low cost, portable CMOS image sensors because of increased integration, and new applications in the automotive, mobile communication and medical industries, amongst others. Colour reproduction remains imperfect in conventional digital image sensors, due to the limitations of the dye-based filters. Further improvement is required if the full potential of digital imaging is to be realised. In alternative systems, where accurate colour reproduction is a priority, existing equipment is too bulky for anything but specialist use. In this work both these issues are addressed by exploiting nanophotonic techniques to create enhanced trichromatic filters, and multispectral filters, all of which can be fabricated on-chip, i.e. integrated into a conventional digital image sensor, to create compact, low cost, mass produceable imaging systems with accurate colour reproduction. The trichromatic filters are based on plasmonic structures. They exploit the excitation of surface plasmon resonances in arrays of subwavelength holes in metal films to filter light. The currently-known analytical expressions are inadequate for optimising all relevant parameters of a plasmonic structure. In order to obtain arbitrary filter characteristics, an automated design procedure was developed that integrated a genetic algorithm and 3D finite-difference time-domain tool. The optimisation procedure's efficacy is demonstrated by designing a set of plasmonic filters that replicate the CIE (1931) colour matching functions, which themselves mimic the human eye's daytime colour response.
Gaussian mixture sigma-point particle filter for optical indoor navigation system
Zhang, Weizhi; Gu, Wenjun; Chen, Chunyi; Chowdhury, M. I. S.; Kavehrad, Mohsen
2013-12-01
With the fast growing and popularization of smart computing devices, there is a rise in demand for accurate and reliable indoor positioning. Recently, systems using visible light communications (VLC) technology have been considered as candidates for indoor positioning applications. A number of researchers have reported that VLC-based positioning systems could achieve position estimation accuracy in the order of centimeter. This paper proposes an Indoors navigation environment, based on visible light communications (VLC) technology. Light-emitting-diodes (LEDs), which are essentially semiconductor devices, can be easily modulated and used as transmitters within the proposed system. Positioning is realized by collecting received-signal-strength (RSS) information on the receiver side, following which least square estimation is performed to obtain the receiver position. To enable tracking of user's trajectory and reduce the effect of wild values in raw measurements, different filters are employed. In this paper, by computer simulations we have shown that Gaussian mixture Sigma-point particle filter (GM-SPPF) outperforms other filters such as basic Kalman filter and sequential importance-resampling particle filter (SIR-PF), at a reasonable computational cost.
The role of model dynamics in ensemble Kalman filter performance for chaotic systems
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.
A Recent Survey on Bloom Filters in Network Intrusion Detection Systems
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K.Saravanan,
2011-03-01
Full Text Available Computer networks are prone to hacking, viruses and other malware; a Network Intrusion Detection System (NIDS is needed to protect the end-user machines from threats. An effective NIDS is therefore anetwork security system capable of protecting the end user machines well before a threat or intruder affects. NIDS requires a space efficient data base for detection of threats in high speed conditions. A bloom filter is a space efficient randomized data structure for representing a set in order to support membership queries. These Bloom filters allow false positive results (FPR but the space saving capability often outweigh this drawback provided the probability of FPR is controlled. Research is being done to reduce FPR by modifying the structure of bloom filters and enabling it to operate in the increasing network speeds, thus variant bloom filters are being introduced. The aim of this paper is to survey the ways in which Bloom filters have been used and modified to be used in high speed Network Intrusion Detection Systems with their merits and demerits.
Toward an Active Fabric-Based Air Decontamination System
2004-12-01
of heterogeneous photo - catalysis on TiO2 . The infrared spectra acquired after irradiation indicate the degradation of CHCl3 due to the...against chemical warfare. Titanium dioxide is widely recognized as a powerful photo -oxidation catalyst.1-3 Research groups have shown TiO2 to be...Successful demonstration of titanium photo - catalysis on fabrics would aid in fostering the transition of this technology into service. Possible
Collision-induced timing jitter in dispersion-managed WDM soliton system with filtering
Institute of Scientific and Technical Information of China (English)
Jianxin Du(杜建新); Qihong Lou(楼祺洪)
2004-01-01
Taking into account the randomicity of collision positions and the arbitrary encoding of data in channel,the influences of different dispersion management on collision-induced timing jitter in a filtered wavelength division multiplexing (WDM) soliton system are obtained statistically and numerically by applying a set of coupled ordinary differential equations which are derived through variational procedure. The optimal dispersion managements which can greatly reduce the collision-induced timing jitter are found. The multi-channel collision-induced timing jitters in a filtered WDM soliton system are given with an optimal dispersion management and constant dispersion.
Directory of Open Access Journals (Sweden)
Yajun Li
2015-01-01
Full Text Available This paper deals with the robust H∞ filter design problem for a class of uncertain neutral stochastic systems with Markovian jumping parameters and time delay. Based on the Lyapunov-Krasovskii theory and generalized Finsler Lemma, a delay-dependent stability condition is proposed to ensure not only that the filter error system is robustly stochastically stable but also that a prescribed H∞ performance level is satisfied for all admissible uncertainties. All obtained results are expressed in terms of linear matrix inequalities which can be easily solved by MATLAB LMI toolbox. Numerical examples are given to show that the results obtained are both less conservative and less complicated in computation.
Souza, André L. G.; Ishihara, João Y.; Ferreira, Henrique C.; Borges, Renato A.; Borges, Geovany A.
2016-12-01
The present work proposes a new approach for an antenna pointing system for satellite tracking. Such a system uses the received signal to estimate the beam pointing deviation and then adjusts the antenna pointing. The present work has two contributions. First, the estimation is performed by a Kalman filter based conical scan technique. This technique uses the Kalman filter avoiding the batch estimator and applies a mathematical manipulation avoiding the linearization approximations. Secondly, a control technique based on the model predictive control together with an explicit state feedback solution are obtained in order to reduce the computational burden. Numerical examples illustrate the results.
Hybrid three-dimensional variation and particle filtering for nonlinear systems
Institute of Scientific and Technical Information of China (English)
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.
Canfield, Stephen
1999-01-01
This work will demonstrate the integration of sensor and system dynamic data and their appropriate models using an optimal filter to create a robust, adaptable, easily reconfigurable state (motion) estimation system. This state estimation system will clearly show the application of fundamental modeling and filtering techniques. These techniques are presented at a general, first principles level, that can easily be adapted to specific applications. An example of such an application is demonstrated through the development of an integrated GPS/INS navigation system. This system acquires both global position data and inertial body data, to provide optimal estimates of current position and attitude states. The optimal states are estimated using a Kalman filter. The state estimation system will include appropriate error models for the measurement hardware. The results of this work will lead to the development of a "black-box" state estimation system that supplies current motion information (position and attitude states) that can be used to carry out guidance and control strategies. This black-box state estimation system is developed independent of the vehicle dynamics and therefore is directly applicable to a variety of vehicles. Issues in system modeling and application of Kalman filtering techniques are investigated and presented. These issues include linearized models of equations of state, models of the measurement sensors, and appropriate application and parameter setting (tuning) of the Kalman filter. The general model and subsequent algorithm is developed in Matlab for numerical testing. The results of this system are demonstrated through application to data from the X-33 Michael's 9A8 mission and are presented in plots and simple animations.
Moment estimation for chemically reacting systems by extended Kalman filtering
Ruess, J; Milias-Argeitis, A; Summers, S; Lygeros, J
2011-01-01
In stochastic models of chemically reacting systems that contain bimolecular reactions, the dynamics of the moments of order up to n of the species populations do not form a closed system, in the sense that their time-derivatives depend on moments of order n + 1. To close the dynamics, the moments o
Park, Jae Hong; Yoon, Ki Young; Na, Hyungjoo; Kim, Yang Seon; Hwang, Jungho; Kim, Jongbaeg; Yoon, Young Hun
2011-09-01
We grew multi-walled carbon nanotubes (MWCNTs) on a glass fiber air filter using thermal chemical vapor deposition (CVD) after the filter was catalytically activated with a spark discharge. After the CNT deposition, filtration and antibacterial tests were performed with the filters. Potassium chloride (KCl) particles (pressure drop across the filter. When a pristine glass fiber filter that had no CNTs was used, the particle filtration efficiencies at particle sizes under 30 nm and near 500 nm were 48.5% and 46.8%, respectively. However, the efficiencies increased to 64.3% and 60.2%, respectively, when the CNT-deposited filter was used. The reduction in the number of viable cells was determined by counting the colony forming units (CFU) of each test filter after contact with the cells. The pristine glass fiber filter was used as a control, and 83.7% of the E. coli were inactivated on the CNT-deposited filter.
Variance-Constrained Multiobjective Control and Filtering for Nonlinear Stochastic Systems: A Survey
Directory of Open Access Journals (Sweden)
Lifeng Ma
2013-01-01
Full Text Available The multiobjective control and filtering problems for nonlinear stochastic systems with variance constraints are surveyed. First, the concepts of nonlinear stochastic systems are recalled along with the introduction of some recent advances. Then, the covariance control theory, which serves as a practical method for multi-objective control design as well as a foundation for linear system theory, is reviewed comprehensively. The multiple design requirements frequently applied in engineering practice for the use of evaluating system performances are introduced, including robustness, reliability, and dissipativity. Several design techniques suitable for the multi-objective variance-constrained control and filtering problems for nonlinear stochastic systems are discussed. In particular, as a special case for the multi-objective design problems, the mixed H2/H∞ control and filtering problems are reviewed in great detail. Subsequently, some latest results on the variance-constrained multi-objective control and filtering problems for the nonlinear stochastic systems are summarized. Finally, conclusions are drawn, and several possible future research directions are pointed out.
Mitigation of Noise in OFDM Based Plc System Using Filter Kernel Design
Directory of Open Access Journals (Sweden)
Nisha G Krishnan
2015-09-01
Full Text Available Power line communication is a technology that transforms power line in to pathway for conveyance of broadband data. It is cost less than other communication approach and for better bandwidth efficiency OFDM based PLC system is used. In real PLC environment some electrical appliances will produce noise. To mitigate this noise filter kernel design is used, so periodic impulsive noise and Gaussian noises are removed from PLC communication system by using this filter kernel design. MATLAB is used for the simulation and the result shows that filter kernel is simple and effective noise mitigation technique. Further in future, interference due to obstacles also wants to be mitigated for the better data transmission without noise.
Ahmad, Nawwar; Ota, Yasuyuki; Nishioka, Kensuke
2017-03-01
We propose a Fresnel lens optical concentration system that can reduce the solar cell temperature. For the reduction of the solar cell temperature, we added a long-wavelength cut filter in order to utilize the part of the solar spectrum that is beneficial to a solar cell while reflecting the rest of the long-wavelength spectrum. A thermal simulation was conducted to estimate the actual cell temperature for optical systems with and without the long-wavelength cut filter, and the results showed a decrease of approximately 25.3 °C in the solar cell temperature using the filter. The lifetime of a solar cell can be extended by reducing its temperature, and the results showed an increase of 1.9 × 105 h in the lifetime of the solar cell.
Fault detection filter design for stochastic time-delay systems with sensor faults
Li, Xiao-Jian; Yang, Guang-Hong
2012-08-01
This article considers the fault detection (FD) problem for a class of Itô-type stochastic time-delay systems subject to external disturbances and sensor faults. The main objective is to design a fault detection filter (FDF) such that it has prescribed levels of disturbance attenuation and fault sensitivity. Sufficient conditions for guaranteeing these levels are formulated in terms of linear matrix inequalities (LMIs), and the corresponding fault detection filter design is cast into a convex optimisation problem which can be efficiently handled by using standard numerical algorithms. In order to reduce the conservatism of filter design with mixed objectives, multi-Lyapunov functions approach is used via Projection Lemma. In addition, it is shown that our results not only include some previous conditions characterising H ∞ performance and H - performance defined for linear time-invariant (LTI) systems as special cases but also improve these conditions. Finally, two examples are employed to illustrate the effectiveness of the proposed design scheme.
Design of a multilevel Active Power Filter for More Electrical Airplane variable frequency systems
Guerreiro, Joel Filipe; Pomilio, Jose Antenor; Busarello, Tiago Davi Curi
This paper presents the design and simulation of an Aeronautical Active Power Filter (AAPF) for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The purposes of the AAPF are to mitigate current harmonics, to improve the source power factor and to mitigate the effects of unbalanced loads. Regarding the fact that the Aircraft Electrical Power System (AEPS) frequency may vary between 360 Hz and 900 Hz, and the load dynamics is often modified, an enhanced filtering technique is required. The designed AAPF topology is an asymmetrical multilevel inverter (AMI), which control strategy is based on the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). The above configuration renders the AAPF very robust and effective to its purpose. Accurate simulation results on Matlab/Simulink platform verify the feasibility of the proposed AAPF and the high performance of the control strategy during steady-state and dynamic operations.
Finite frequency H_∞ filtering for uncertain discrete-time switched linear systems
Institute of Scientific and Technical Information of China (English)
Dawei Ding; Guanghong Yang
2009-01-01
This paper is concerned with the problem of robust H_∞ filtering for discrete-time switched linear systems with polytopic uncertainties in the finite frequency domain. Based on the generalized Kalman-Yakubovich-Popov (GKYP) iemma and switched parameter-depen-dent Lyapunov functions, a switched full-order filter is designed such that the corresponding filtering error system is asymptotically sta-ble and satisfies a prescribed finite frequency H_∞ performance index. Compared with the existing full frequency approaches, the proposed finite frequency one receives better results for the cases in which the frequency ranges of noises are known. A numerical exam-ple is given to illustrate the effectiveness of the proposed method.
Quantum Master Equation and Filter for Systems Driven by Fields in a Single Photon State
Gough, J E; Nurdin, H I
2011-01-01
The aim of this paper is to determine quantum master and filter equations for systems coupled to continuous-mode single photon fields. The system and field are described using a quantum stochastic unitary model, where the continuous-mode single photon state for the field is determined by a wavepacket pulse shape. The master equation is derived from this model and is given in terms of a system of coupled equations. The output field carries information about the system from the scattered photon, and is continuously monitored. The quantum filter is determined with the aid of an embedding of the system into a larger system, and is given by a system of coupled stochastic differential equations. An example is provided to illustrate the main results.
A variational Bayesian multiple particle filtering scheme for large-dimensional systems
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.
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.
Method and system for training dynamic nonlinear adaptive filters which have embedded memory
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.
Method of securing filter elements
Energy Technology Data Exchange (ETDEWEB)
Brown, Erik P.; Haslam, Jeffery L.; Mitchell, Mark A.
2016-10-04
A filter securing system including a filter unit body housing; at least one tubular filter element positioned in the filter unit body housing, the tubular filter element having a closed top and an open bottom; a dimple in either the filter unit body housing or the top of the tubular filter element; and a socket in either the filter unit body housing or the top of the tubular filter element that receives the dimple in either the filter unit body housing or the top of the tubular filter element to secure the tubular filter element to the filter unit body housing.
Energy Technology Data Exchange (ETDEWEB)
Sudo, H. [Japan Automobile Research Institute Inc., Tsukuba (Japan)
1997-10-01
An environmental air quality of suspended particulate matter is insufficient in the big city area. To reduce the particulate matter, improvement of engine and development of the Diesel Particulate Filter (DPF) system are carrying. The purpose of this report is to investigate a possibility of practical use of the city buses installed DPF systems. From March 1995, investigation for practical use of these DPF systems on a route buses was carried in regular service operation of the Tokyo and Yokohama Transportation Bureau. The investigation items are service situation, smoke density and preparation inspection. From the result for 2 years service operation, each DPF systems needed some failure correspondence. but these were not fatal problem on using the DPF system. Then the subject of relative to durability and reliability became clear, and the performance of a low particulate emission DPF system obtained the high value evaluation for users. 9 refs., 4 figs., 2 tabs.
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...
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...
A versatile real-time deconvolution DSP system implemented using a time domain inverse filter
Gaydecki, Patrick
2001-01-01
A proof-of-principle, digital signal processing system is described which can perform deconvolution of audio-bandwidth signals in real time, enabling separation and precise measurement of pulses smeared by a given impulse response. The system operates by convolving a time-domain expression of an inverse filter with the original signal to generate a processed output. It incorporates a high-level user interface for the design of the inverse filter, a communications system and a purpose-designed digital signal processing environment employing a Motorola DSP56002 device. The user interface is extremely versatile, allowing arbitrary inverse filters to be designed and executed within seconds, using a modified frequency sampling method. Since the inverse filters are realized using a symmetrical finite impulse response, no phase distortion is introduced into the processed signals. A special feature of the design is the manner in which the software and hardware components have been organized as an intelligent system, obviating on the part of the user a detailed knowledge of filter design theory or any abilities in processor architecture and assembly code programming. At the present time, the system is capable of deconvolving signals sampled up to 48 kHz. It is therefore ideally suited for real-time audio enhancement, for example, in telephony, public address and long-range broadcast systems, and in compensating for building or room acoustics. Recent advances in DSP technology will enable the same system structure to be applied to signals sampled at frequencies ten times this rate and beyond. This will allow the real-time deconvolution of low-frequency ultrasonic signals used in the inspection and imaging of heterogeneous media.
Contexts in a Paper Recommendation System with Collaborative Filtering
Winoto, Pinata; Tang, Tiffany Ya; McCalla, Gordon
2012-01-01
Making personalized paper recommendations to users in an educational domain is not a trivial task of simply matching users' interests with a paper topic. Therefore, we proposed a context-aware multidimensional paper recommendation system that considers additional user and paper features. Earlier experiments on experienced graduate students…
An E-Commerce Recommender System Based on Content-Based Filtering
Institute of Scientific and Technical Information of China (English)
HE Weihong; CAO Yi
2006-01-01
Content-based filtering E-commerce recommender system was discussed fully in this paper. Users' unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products information, the recommender lists were obtained. Since the system can adapt to the users' feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.
Recovery of systems with a linear filter and nonlinear delay feedback in periodic regimes.
Ponomarenko, V I; Prokhorov, M D
2008-12-01
We propose a set of methods for the estimation of the parameters of time-delay systems with a linear filter and nonlinear delay feedback performing periodic oscillations. The methods are based on an analysis of the system response to regular external perturbations and are valid only for systems whose dynamics can be perturbed. The efficiency of the methods is illustrated using both numerical and experimental data.
Energy Technology Data Exchange (ETDEWEB)
Sjostrom, Sharon; Amrhein, Jerry
2009-04-30
The power industry in the U.S. is faced with meeting regulations to reduce the emissions of mercury compounds from coal-fired plants. Injecting a sorbent such as powdered activated carbon (PAC) into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The purpose of this test program was to evaluate the long-term mercury removal capability, long-term mercury emissions variability, and operating and maintenance (O&M) costs associated with sorbent injection on a configuration being considered for many new plants. Testing was conducted by ADA Environmental Solutions (ADA) at Rocky Mountain Power’s (RMP) Hardin Station through funding provided by DOE/NETL, RMP, and other industry partners. The Hardin Station is a new plant rated at 121 MW gross that was first brought online in April of 2006. Hardin fires a Powder River Basin (PRB) coal and is configured with selective catalytic reduction (SCR) for NOx control, a spray dryer absorber (SDA) for SO2 control, and a fabric filter (FF) for particulate control. Based upon previous testing at PRB sites with SCRs, very little additional mercury oxidation from the SCR was expected at Hardin. In addition, based upon results from DOE/NETL Phase II Round I testing at Holcomb Station and results from similarly configured sites, low native mercury removal was expected across the SDA and FF. The main goal of this project was met—sorbent injection was used to economically and effectively achieve 90% mercury control as measured from the air heater (AH) outlet to the stack for a period of ten months. This goal was achieved with DARCO® Hg-LH, Calgon FLUEPAC®-MC PLUS and ADA Power PAC PREMIUM brominated activated carbons at nominal loadings of 1.5–2.5 lb/MMacf. An economic analysis determined the twenty-year levelized cost to be 0.87 mills/kW-hr, or $15,000/lb Hg removed. No detrimental effects on other equipment or plant operations were observed. The
Energy Technology Data Exchange (ETDEWEB)
PIEPHO, M.G.
2000-01-10
Four bounding accidents postulated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing a hydrogen explosion, and a fire breaching filter vessel and enclosure. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.
Methodology for adapting the parameters of a fuzzy system using the extended Kalman filter
2011-01-01
When we try to analyze and to control a system whose model was obtained only based on input/output data, accuracy is essential in the model. On the other hand, to make the procedure practical, the modeling stage must be computationally efficient. In this regard, this paper presents the application of extended Kalman filter for the parametric adaptation of a fuzzy model.
40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?
2010-07-01
... in at least 95 percent of the turbidity measurements taken each month. Measurements must continue to... 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...
Greenhouse with an Integrated NIR Filter and a Solar Cooling System
Sonneveld, P.J.; Swinkels, G.L.A.M.; Kempkes, F.L.K.; Campen, J.B.; Bot, G.P.A.
2006-01-01
The scope of this paper is a new greenhouse design that incorporates both a filter for rejecting near infrared radiation (NIR) and a solar cooling system. Cooled greenhouses are an important issue for the combination of high global radiation and high outdoor temperatures. As a first measure, this
Si(Li) x-ray spectrometer with signal processing system based on digital filtering
Energy Technology Data Exchange (ETDEWEB)
Lakatos, T. (Magyar Tudomanyos Akademia, Debrecen. Atommag Kutato Intezete)
1985-01-01
A new signal processing system is under development at ATOMKI, Debrecen, Hungary, based on digital filtering by a microprocessor. The advantages of the new method are summarized. Dead time can be decreased and the speed of signal processing can be increased. Computer simulations verified the theoretical conclusions.
Energy Technology Data Exchange (ETDEWEB)
ERMI, A.M.
2000-09-05
The HEPA Filter Differential Pressure Fan Interlock System PLC ladder logic software was tested using a Software Verification and Validation (V&V) Test Plan as required by the ''Computer Software Quality Assurance Requirements''. The purpose of his document is to report on the results of the software qualification.
Greenhouse with an Integrated NIR Filter and a Solar Cooling System
Sonneveld, P.J.; Swinkels, G.L.A.M.; Kempkes, F.L.K.; Campen, J.B.; Bot, G.P.A.
2006-01-01
The scope of this paper is a new greenhouse design that incorporates both a filter for rejecting near infrared radiation (NIR) and a solar cooling system. Cooled greenhouses are an important issue for the combination of high global radiation and high outdoor temperatures. As a first measure, this st
Pimenta, S; Cardoso, S; Miranda, A; De Beule, P; Castanheira, E M S; Minas, G
2015-08-01
This paper presents the design, optimization and fabrication of 16 MgO/TiO2 and SiO2/TiO2 based high selective narrow bandpass optical filters. Their performance to extract diffuse reflectance and fluorescence signals from gastrointestinal tissue phantoms was successfully evaluated. The obtained results prove their feasibility to correctly extract those spectroscopic signals, through a Spearman's rank correlation test (Spearman's correlation coefficient higher than 0.981) performed between the original spectra and the ones obtained using those 16 fabricated optical filters. These results are an important step for the implementation of a miniaturized, low-cost and minimal invasive microsystem that could help in the detection of gastrointestinal dysplasia.
Improved H_∞ filtering for Markov jumping linear systems with non-accessible mode information
Institute of Scientific and Technical Information of China (English)
GUO YaFeng; LI ShaoYuan
2009-01-01
This paper is concerned with the H_∞ filtering problems for both continuous-and discrete-time Markov jumping linear systems (MJLS) with non-accessible mode Information.A new design method is proposed,which greatly reduces the overdesign Introduced in the derivation process.The desired filters can be obtained from the solution of convex optimization problems in terms of linear matrix inequalities (LMIs),which can be solved via efficient interior-point algorithms.Numerical examples are provided to Illustrate the advantages of the proposed approach.
Design of an Attitude and Heading Reference System Based on Distributed Filtering for Small UAV
Directory of Open Access Journals (Sweden)
Long Zhao
2013-01-01
Full Text Available A development procedure for a low-cost attitude and heading reference system (AHRS based on the distributed filter has been proposed. The AHRS consists of three single-axis accelerometers, three single-axis gyroscopes, and one 3-axis digital compass. The initial attitude estimation is readily accomplished by using the complementary filtering. The attitude estimation for UAV flying in the real time is realized by using the three low orders EKF. The validation results show that the estimated orientations of the developed AHRS are within the acceptable region, and AHRS can give a stabilized attitude and heading information for a long time.
Speed Estimation of Induction Motor Using Model Reference Adaptive System with Kalman Filter
Directory of Open Access Journals (Sweden)
Pavel Brandstetter
2013-01-01
Full Text Available The paper deals with a speed estimation of the induction motor using observer with Model Reference Adaptive System and Kalman Filter. For simulation, Hardware in Loop Simulation method is used. The first part of the paper includes the mathematical description of the observer for the speed estimation of the induction motor. The second part describes Kalman filter. The third part describes Hardware in Loop Simulation method and its realization using multifunction card MF 624. In the last section of the paper, simulation results are shown for different changes of the induction motor speed which confirm high dynamic properties of the induction motor drive with sensorless control.
Filter-design perspective applying to dynamical decoupling of a multi-qubit system
Zhi-Kun, Su; Shao-Ji, Jiang
2011-01-01
We employ the filter-design perspective and derive the filter functions according to nested Uhrig dynamical decoupling (NUDD) and Symmetric dynamical decoupling (SDD) in the pure-dephasing spin-boson model with N qubits. The performances of NUDD and SDD are discussed in detail for a two-qubit system. The analysis shows that (i) SDD outperforms NUDD for the bath with a soft cutoff while NUDD approaches SDD as the cutoff becomes harder; (ii) if the qubits are coupled to a common reservoir, SDD ...
Peterson, A.; Narasimha, M.; Narayan, S.
1980-01-01
The system design of a wideband (8 MHz) million-channel digital spectrum analyzer for use with a SETI receiver is presented. The analyzer makes use of a digital bandpass filter bank for transforming the wideband input signal into a specified number (120) of uniform narrowband output channels by the use of a Fourier transform digital processor combined with a prototype digital weighting network (finite impulse response filter). The output is then processed separately by 120 microprocessor-based discrete Fourier transform computers, each producing 8190 output channels of approximately 8 Hz bandwidth by the use of an 8190-point prime factor algorithm.
Kalman Filter Integration of Modern Guidance and Navigation Systems
1989-07-04
TRAJECTOGRAPHIE PASSIVE PAR AZIMUT: AMELIORATION DE LA QUALITE D’ESTIMATION par P.Vacher, M.Gauivrit, G.Maynard De Lavalette et P.Mennecler 8 BIBLIOGRAPHY...airborne iystem configured with an Inertial system, a1 synlhetlc aperture radar , a doppler radar and other sensors that were .,uccessfully flight tested...for Precision Pointing Applications", NAECLN 1979 RECORD, pp. 1033-1039 2-13 RADA~R ON RADAR MODE FLIGHT PROFILE PICTURE FREEZE ...... .....- F~ue
Report on system confirmation test of the used filter transporting vessel. 1
Energy Technology Data Exchange (ETDEWEB)
Ishii, Kiyoto; Morita, Shin-ichi; Hanada, Keiji; Ouchi, Kazutoshi; Kawakami, Kazuyoshi; Uryu, Mitsuru; Karino, Motonobu
1997-05-01
As an exchanging method of vacuum filter element installed at vacuum system of the Recycle Equipment Test Facility (RETF), the cask method is determined to use at a viewpoint of pollution expansion protection and radiation exposure reduction of workers. A principle proof test was conducted after trial protection of main parts according to design conducted in 1995 fiscal year. As a result, it was found that filter element (after storing a container) could be exhausted without any problem, in falling test of exhausting chute, that a setting method of exchanger onto upper part of the filter unit was required to improve, that a set of filter exchanging medium could be conducted scarcely any problem, that a load required to push a filter element into the determined position was at least 37 kg, and that an allowable interval at jointing with a double-door flange was 0.8 mm and air tightness could be kept if its inclination is less tha 0.85 mm. (G.K.)
The Application of Federated Kalman Filtering in SINS/GPS/CNS Intergrated Navigation System
Directory of Open Access Journals (Sweden)
DENG Chun-lin
2012-04-01
Full Text Available Federated filter was an important method to estimate high-precision navigation parameters based on “SINS/GPS/CNS”. A no-feedback federated filter with UD_UKF algorithm was designed in the paper, a threetime amendment scheme to correct navigation parameters was designed at the same time and the mathematical model of SINS/GPS/CNS was established in launch inertial coordinate system too. The paper discussed the simulation conditions and a lot of simulations were carried out to compare 2 aspects: (1the performance between four navigation mode, which respectively is SINS, SINS/GPS, SINS/CNS, SINS/GPS/CNS;(2the estimate precision of federated filter and that of centralized Kalman filter. The results of simulation showed that the designed federated filter and amendment scheme based on SINS/GPS/CNS had high estimate precision and led to gain high hitting precision of ballistic missile, that is to say position errors were less than 20 meter and velocity errors were less than 0.1m/s in simulation.
Directory of Open Access Journals (Sweden)
Seung Hyeop Yang
2013-01-01
Full Text Available This paper describes the synthesis of a robust and nonfragile H∞ Kalman-type filter design for a class of time-delay systems with polytopic uncertainties, filter-gain variations, and disturbances. We present the sufficient condition for filter existence and the method for designing a robust nonfragile H∞ filter by using LMIs (Linear Matrix Inequalities technique. Because the obtained sufficient condition can be represented as PLMIs (Parameterized Linear Matrix Inequalities, which can generate infinite LMIs, we use a relaxation technique to find finite solutions for a robust nonfragile H∞ filter. We show that the proposed filter can minimize estimation error in terms of parameter uncertainties, filter-fragility, and disturbances.
Aguirre, Luis Antonio; Billings, S. A.
This paper investigates the identification of global models from chaotic data corrupted by additive noise. It is verified that noise has a strong influence on the identification of chaotic systems. In particular, there seems to be a critical noise level beyond which the accurate estimation of polynomial models from chaotic data becomes very difficult. Similarities with the estimation of the largest Lyapunov exponent from noisy data suggest that part of the problem might be related to the limited ability of predicting the data records when these are chaotic. A nonlinear filtering scheme is suggested in order to reduce the noise in the data and thereby enable the estimation of good models. This prediction-based filtering incorporates a resetting mechanism which enables the filtering of chaotic data and which is also applicable to non-chaotic data.
Directory of Open Access Journals (Sweden)
M. Mohammadi
2015-01-01
Full Text Available This paper presents the optimal planning of harmonic passive filters in distribution system using three intelligent methods including genetic algorithm (GA, particle swarm optimization (PSO, artificial bee colony (ABC and as a new research is compared with biogeography based optimization (BBO algorithm. In this work, the considered objective function is to minimize the value of investment cost of filters and total harmonic distortion of three-phase current. It is shown that through an economical placement and sizing of LC passive filters the total voltage harmonic distortion and cost could be minimized simultaneously. BBO is a novel evolutionary algorithm that is based on the mathematics of biogeography. In the BBO model, problem solutions are represented as islands, and the sharing of features between solutions is represented as immigration and emigration between the islands. The simulation results show that the proposed method is efficient for solving the presented problem.
Sensor Fault Estimation Filter Design for Discrete-time Linear Time-varying Systems
Institute of Scientific and Technical Information of China (English)
WANG Zhen-Hua; RODRIGUES Mickael; THEILLIOL Didier; SHEN Yi
2014-01-01
This paper proposes a sensor fault diagnosis method for a class of discrete-time linear time-varying (LTV) systems. In this paper, the considered system is firstly formulated as a de-scriptor system representation by considering the sensor faults as auxiliary state variables. Based on the descriptor system model, a fault estimation filter which can simultaneously estimate the state and the sensor fault magnitudes is designed via a minimum-variance principle. Then, a fault diagnosis scheme is presented by using a bank of the proposed fault estimation filters. The novelty of this paper lies in developing a sensor fault diagnosis method for discrete LTV systems without any assumption on the dynamic of fault. Another advantage of the proposed method is its ability to detect, isolate and estimate sensor faults in the presence of process noise and measurement noise. Simulation results are given to illustrate the effectiveness of the proposed method.
A DSP-Based Beam Current Monitoring System for Machine Protection Using Adaptive Filtering
Energy Technology Data Exchange (ETDEWEB)
J. Musson; H. Dong; R. Flood; C. Hovater; J. Hereford
2001-06-01
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.
Fundamentals and advances in the development of remote welding fabrication systems
Agapakis, J. E.; Masubuchi, K.; Von Alt, C.
1986-01-01
Operational and man-machine issues for welding underwater, in outer space, and at other remote sites are investigated, and recent process developments are described. Probable remote welding missions are classified, and the essential characteristics of fundamental remote welding tasks are analyzed. Various possible operational modes for remote welding fabrication are identified, and appropriate roles for humans and machines are suggested. Human operator performance in remote welding fabrication tasks is discussed, and recent advances in the development of remote welding systems are described, including packaged welding systems, stud welding systems, remotely operated welding systems, and vision-aided remote robotic welding and autonomous welding systems.
Energy Technology Data Exchange (ETDEWEB)
Sjostrom, Sharon; Amrhein, Jerry
2009-04-30
The power industry in the U.S. is faced with meeting regulations to reduce the emissions of mercury compounds from coal-fired plants. Injecting a sorbent such as powdered activated carbon (PAC) into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The purpose of this test program was to evaluate the long-term mercury removal capability, long-term mercury emissions variability, and operating and maintenance (O&M) costs associated with sorbent injection on a configuration being considered for many new plants. Testing was conducted by ADA Environmental Solutions (ADA) at Rocky Mountain Power’s (RMP) Hardin Station through funding provided by DOE/NETL, RMP, and other industry partners. The Hardin Station is a new plant rated at 121 MW gross that was first brought online in April of 2006. Hardin fires a Powder River Basin (PRB) coal and is configured with selective catalytic reduction (SCR) for NOx control, a spray dryer absorber (SDA) for SO2 control, and a fabric filter (FF) for particulate control. Based upon previous testing at PRB sites with SCRs, very little additional mercury oxidation from the SCR was expected at Hardin. In addition, based upon results from DOE/NETL Phase II Round I testing at Holcomb Station and results from similarly configured sites, low native mercury removal was expected across the SDA and FF. The main goal of this project was met—sorbent injection was used to economically and effectively achieve 90% mercury control as measured from the air heater (AH) outlet to the stack for a period of ten months. This goal was achieved with DARCO® Hg-LH, Calgon FLUEPAC®-MC PLUS and ADA Power PAC PREMIUM brominated activated carbons at nominal loadings of 1.5–2.5 lb/MMacf. An economic analysis determined the twenty-year levelized cost to be 0.87 mills/kW-hr, or $15,000/lb Hg removed. No detrimental effects on other equipment or plant operations were observed. The
Zipf, Mariah Siebert; Pinheiro, Ivone Gohr; Conegero, Mariana Garcia
2016-07-01
One of the main actions of sustainability that is applicable to residential, commercial, and public buildings is the rational use of water that contemplates the reuse of greywater as one of the main options for reducing the consumption of drinking water. Therefore, this research aimed to study the efficiencies of simplified treatments for greywater reuse using slow sand and slow slate waste filtration, both followed by granular activated carbon filters. The system monitoring was conducted over 28 weeks, using analyses of the following parameters: pH, turbidity, apparent color, biochemical oxygen demand (BOD), chemical oxygen demand (COD), surfactants, total coliforms, and thermotolerant coliforms. The system was run at two different filtration rates: 6 and 2 m(3)/m(2)/day. Statistical analyses showed no significant differences in the majority of the results when filtration rate changed from 6 to 2 m(3)/m(2)/day. The average removal efficiencies with regard to the turbidity, apparent color, COD and BOD were 61, 54, 56, and 56%, respectively, for the sand filter, and 66, 61, 60, and 51%, respectively, for the slate waste filter. Both systems showed good efficiencies in removing surfactants, around 70%, while the pH reached values of around 7.80. The average removal efficiencies of the total and thermotolerant coliforms were of 61 and 90%, respectively, for the sand filter, and 67 and 80%, respectively, for the slate waste filter. The statistical analysis found no significant differences between the responses of the two systems, which attest to the fact that the slate waste can be a substitute for sand. The maximum levels of efficiency were high, indicating the potential of the systems, and suggesting their optimization in order to achieve much higher average efficiencies.
Real-Time Flood Forecasting System Using Channel Flow Routing Model with Updating by Particle Filter
Kudo, R.; Chikamori, H.; Nagai, A.
2008-12-01
A real-time flood forecasting system using channel flow routing model was developed for runoff forecasting at water gauged and ungaged points along river channels. The system is based on a flood runoff model composed of upstream part models, tributary part models and downstream part models. The upstream part models and tributary part models are lumped rainfall-runoff models, and the downstream part models consist of a lumped rainfall-runoff model for hillslopes adjacent to a river channel and a kinematic flow routing model for a river channel. The flow forecast of this model is updated by Particle filtering of the downstream part model as well as by the extended Kalman filtering of the upstream part model and the tributary part models. The Particle filtering is a simple and powerful updating algorithm for non-linear and non-gaussian system, so that it can be easily applied to the downstream part model without complicated linearization. The presented flood runoff model has an advantage in simlecity of updating procedure to the grid-based distributed models, which is because of less number of state variables. This system was applied to the Gono-kawa River Basin in Japan, and flood forecasting accuracy of the system with both Particle filtering and extended Kalman filtering and that of the system with only extended Kalman filtering were compared. In this study, water gauging stations in the objective basin were divided into two types of stations, that is, reference stations and verification stations. Reference stations ware regarded as ordinary water gauging stations and observed data at these stations are used for calibration and updating of the model. Verification stations ware considered as ungaged or arbitrary points and observed data at these stations are used not for calibration nor updating but for only evaluation of forecasting accuracy. The result confirms that Particle filtering of the downstream part model improves forecasting accuracy of runoff at
Efficient fabrication of micro- and nano-systems
DEFF Research Database (Denmark)
Birkelund, Karen; Hanberg, Peter Jesper; Jørgensen, Anders Michael
2014-01-01
analyzing of e.g.waste water before it is lead out in our lakes and oceans or as sensors notifying when maintenance i srequired in due time before breakdown.More and more of these sensors are also made self-sufficient of power by harvesting the energy from e.g.the sun, thermal excess energy, environmental...... as minimizing the consumption of materials, etchants and process time. Danchip excels in optimizing micro- and nanofabrication in order to simplify processes, minimize cost and at the same time maximize yield. Danchips team of process generalists is ready to guide you through your design and planning phase...... as wellas to help you realizing your micro- and nano-devices in our clean room facilities. Danchips team of process specialists will help you with developing and optimizing new fabrication processes so you can reach your goals most efficiently. Our dedicated technical staff supports the infrastructure...
Sen, Subhamoy; Crinière, Antoine; Mevel, Laurent; Cerou, Frederic; Dumoulin, Jean
2017-04-01
Keywords: Parameter estimation; Kalman filter; Particle filter; Particle-Kalman filter; Correlated noise Although Kalman filter (KF) was originally proposed for system control i.e. steering a system as desired by monitoring the system states, its application for parameter estimation problems is widespread because of the excellent similarity between these two apparently different problem types in state space description. In standard Kalman filter, system dynamics is described through the dynamics of certain internal variable, termed as states, evolving over time as defined by an assumed process model, while a measurement model maps these states to measurements. In some parameter estimation problems, the system is replaced by a state space formulation of the dynamic model with parameters appended in the unobserved states and collectively observed through the response measurements. Filtering based parameter estimation problems are thus inherently nonlinear due to the required nonlinear mapping of parameters to the corresponding observations. Being a linear estimator, Kalman Filter (KF) cannot be employed for such nonlinear system estimation and alternative filtering algorithms (eg. Particle filter) are therefore generally used. However, being model based, these filters optimally estimate the parameters of a quasi-static model of the real dynamic system. Consequently, any time variation in the system dynamics may completely diverge the estimation yielding a false or infeasible solution. By decoupling the estimation of system states and parameters, and applying concurrent filtering strategy that attempts conditional estimation of states based on parameters and vice versa, time varying systems can be estimated. This article attempts to combine KF with Particle filter (PF) and apply them for estimation of states and system parameters respectively on a system with correlated noise in process and measurement. The idea is to nest a bank of linear KFs for state estimation
Novel spatially distributed porous Si optical bandpass filters
Tokranova, N.; Levitsky, I.; Gracias, A.; Xu, B.; Castracane, J.
2006-02-01
To assist the growth of the telecommunication sector, new types of optical components such as those based on optical interference filter technology are critical. Existing technologies based on thin-film processing for production of optical communications filters have rapidly advanced. Although the Fabry-Perot bandpass filters made by deposition of alternate layers with high- and low- refractive index have a broad rejection band and a narrow passband, this technique does not allow for the control of filter parameters such as specification and adjustment of the transmitted wavelength at any place across the surface of the filter. The new approach discussed in the paper is directed toward the anodization of silicon to fabricate not only multilayer optical filters with a uniform passband across the field of view but also specially designed passbands at any single point in the field of view of the optical system. In particular, the realization and characterization of spatially distributed filters made of porous silicon are presented. These filters are able to select various passbands in the visible and IR regions. The filters were fabricated on p + and p - type doped substrates. By varying the electrode configuration on the backside of wafer and the applied potential during electrochemical etching, the desired spatially distributed filter can be formed. The impact of wafer resistivity on filter parameters is discussed.
An iterative denoising system based on Wiener filtering with application to biomedical images
Lahmiri, Salim
2017-05-01
Biomedical image denoising systems are important for accurate clinical diagnosis. The purpose of this study is to present a simple and effective iterative multistep image denoising system based on Wiener filtering (WF) where the denoised image from one stage is the input to the next stage. The denoising process stops when a particular condition measured by image energy is adaptively achieved. The proposed iterative system is tested on real clinical images and performance is measured by the well-known peak-signal-to-noise-ratio (PSNR) statistic. Experimental results showed that the proposed iterative system outperforms conventional image denoising algorithms; including wavelet packet (WP), fourth order partial differential equation (FOPDE), nonlocal Euclidean means (NLEM), first order local statistics (FOLS), and single Wiener filter used as baseline model. The experimental results demonstrate that the proposed approach can remove noise automatically and effectively while edges and texture characteristics are preserved.
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.
Optimal Filtering Algorithm-Based Multiuser Detector for Fast Fading CDMA Systems
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A multiuser detector was developed for fast fading code-division multiple-access systems by representing the channels as a system with the multiplicative noise (SMN) model and then using the known optimal filtering algorithm for the SMN for multiuser detection (MUD). This multiuser detector allows the channel response to be stochastic in one symbol duration, which can be regarded as an effective method of MUD for fast fading CDMA systems. Performance analyses show that the multiuser detector is theoretically valid for CDMA systems over fast fading channels. Simulations show that the multiuser detector performs better than the Kalman filter-based multiuser detector with a faster convergence rate and lower bit error rate.
Performance of a grid connected PV system used as active filter
Energy Technology Data Exchange (ETDEWEB)
Calleja, H. [Cenidet, Morelos (Mexico). Electronics Dept.; Jimenez, H. [IIE, Morelos (Mexico). Conventional Energy Sources Dept.
2004-09-01
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. (author)
Energy Technology Data Exchange (ETDEWEB)
Sekiya, N., E-mail: nsekiya@yamanashi.ac.jp
2016-08-15
Highlights: • We have developed two high-order HTS dual-band BPFs with a receiver subsystem for future mobile communication systems. • We developed a method for flexibly adjusting the coupling coefficient for the two passbands. • We demonstrated an HTS dual-band BPF receiver subsystem that uses a pulse tube cryocooler and a wideband LNA. • The proposed BPF is evaluated by simulation and measurement with good agreement. - Abstract: We have developed two high-order high-temperature superconducting (HTS) dual-band bandpass filters (BPFs) with a receiver subsystem for future mobile communication systems. They feature stub-loaded hair-pin resonators with two types of microstrip lines between them. One has a six-pole design, and the other has an eight-pole design. Both were designed to operate at 2.15 GHz with a 43-MHz (2%) bandwidth for the lower passband and at 3.50 GHz with a 70-MHz (2%) bandwidth for the upper one. They were fabricated using YBa{sub 2}Cu{sub 3}O{sub y} thin film on a CeO{sub 2}-bufferd r-Al{sub 2}O{sub 3} substrate. The measured results for both filters agree well with the simulated ones. The HTS dual-band BPF receiver subsystem uses a pulse tube cryocooler and a wideband low noise amplifier (LNA). We measured the frequency response of the six-pole dual-band BPF with and without a wideband LNA with a gain of 10 dB. The measured return losses were close.
Thermal Hydraulic Analysis on Containment Filtered Venting System
Energy Technology Data Exchange (ETDEWEB)
Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd., Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)
2014-05-15
In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary.
Mercury sorbent delivery system for flue gas
Klunder; ,Edgar B.
2009-02-24
The invention presents a device for the removal of elemental mercury from flue gas streams utilizing a layer of activated carbon particles contained within the filter fabric of a filter bag for use in a flue gas scrubbing system.
Fabrication of polystyrene microfluidic devices using a pulsed CO2 laser system
Li, Huawei
2013-10-10
In this article, we described a simple and rapid method for fabrication of droplet microfluidic devices on polystyrene substrate using a CO2 laser system. The effects of the laser power and the cutting speed on the depth, width and aspect ratio of the microchannels fabricated on polystyrene were investigated. The polystyrene microfluidic channels were encapsulated using a hot press bonding technique. The experimental results showed that both discrete droplets and laminar flows could be obtained in the device.
Transport of ultracold neutrons through a mirror system with surface roughness as a velocity filter
Chizhova, L A; Jenke, T; Cronenberg, G; Geltenbort, P; Abele, H; Burgdörfer, J
2012-01-01
We perform classical Monte Carlo simulations of ultracold neutron transport through an absorbing-reflecting mirror system in the Earth's gravitational field. We show that the underlying mixed phase space of regular skipping motion and random motion due to disorder scattering can be exploited to realize a velocity filter for ultracold neutrons. The range of velocities selected is controlled by geometric parameters of the wave guide. Possible applications include investigations of transport and scattering dynamics in confined systems.
DSP control of photovoltaic power generation system adding the function of shunt active power filter
Energy Technology Data Exchange (ETDEWEB)
Seo, H.-R.; Kim, K.-H.; Park, Y.-G.; Park, M.; Yu, I.-K. [Changwon National Univ., SarimDong (Korea, Republic of). Dept. of Electrical Engineering
2007-07-01
The growing number of power electronics-based equipment has created a problem on the quality of electric power supply since both high power industrial loads and domestic loads cause harmonics in the network voltage. Power quality problems can occur in the system or can be caused by the consumer. Active filter (AF) is widely used to compensate current harmonics and/or current imbalance of harmonic-producing loads. The power output of a photovoltaic (PV) system is directly affected by weather conditions. When alternating current (AC) power supply is required, power conversion by an inverter and an MPPT control is necessary. The proliferation of nonlinear loads such as inverter of PV power generation system can be treated as a harmonic source for the power distribution system. As such, the PV system combined with the function of the active filter system can be useful for the application in power distribution systems. This paper described a PV-AF system using DSP to prove that it is possible to combine AF theory to the three phase PV system connected to utility and verify it through experimental results. The paper described the control method of the PV-AF system, with reference to the photovoltaic power generation system, shunt active filter and PV-AF system. The experimental set-up was also presented. A laboratory system was designed and constructed to confirm the viability of the proposed PV-AF system. The test results revealed the stability and effectiveness of the proposed PV-AF system. 12 refs., 1 tabs., 12 figs.
Adaptive system noise covariance for performance enhancement of Kalman filter-based algorithms
Lee, Vika; Chan, Keith C. C.; Leung, Henry
1996-06-01
Several designs of Kalman filters and the interacting multiple models algorithm were used in real tracking tasks involving high dynamic targets. The data were obtained through the joint effort of the defense departments of Canada and the US. Their performance, measured in terms of positional deviation and the number of track losses, are rather unsatisfactory even though they perform particularly well when using simulated data. To identify the reasons behind, we compared and analyzed the differences between the model assumptions behind the design of these Kalman filters and the model required for accurate tracking of these targets. In this paper, we discussed our findings. Moreover, based on the characteristics of real tracking data, we present an alternative methodology for measuring the effectiveness of various Kalman filter based trackers in stressful environmental. It can also be used to explain the well known characteristics of Kalman filter. A lower bound for the deviation, obtained from this equation, shows that deviation could be too large to manage if noise bandwidth is as high as the real data instead of a pre-assumed magnitude. Instead of having to redesign many existing Kalman filters to suit for stressful environment, we developed a design-independent module that can be added to different types of Kalman filters based trackers to enhance their performance in the tracking high dynamic targets. The module is called adaptive systems noise covariance estimation. It is not only safe (i.e. almost no negative effect) but it can sometimes even double the performance of trackers in stressful environment.
Noise degradation system using Wiener filter and CORDIC based FFT/IFFT processor
Institute of Scientific and Technical Information of China (English)
Yasodai A; Ramprasad A V
2015-01-01
On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology was embraced for expanding the execution of the system. The proposed Wiener filter was planned in such an approach to evacuate the iteration issues in ordinary Wiener filter. The division process was supplanted by a productive inverse and multiplication process in the proposed design. An enhanced design for matrix inverse with reduced computation complexity was executed. The wide-ranging framework processing was focused around IEEE-754 standard single precision floating point numbers. The Wiener filter and the entire system design was integrated and actualized on VIRTEX 5 FPGA stage and re-enacted to approve the results in Xilinx ISE 13.4. The results show that a productive decrease in power and area is developed by adjusting the proposed technique for speech signal noise degradation with latency ofn/2 clock cycles and substantial throughput result per every 12 clock cycles forn-bit precision. The execution of proposed design is exposed to be 31.35% more effective than that of prevailing strategies.
Maximum-Likelihood Adaptive Filter for Partially Observed Boolean Dynamical Systems
Imani, Mahdi; Braga-Neto, Ulisses M.
2017-01-01
Partially-observed Boolean dynamical systems (POBDS) are a general class of nonlinear models with application in estimation and control of Boolean processes based on noisy and incomplete measurements. The optimal minimum mean square error (MMSE) algorithms for POBDS state estimation, namely, the Boolean Kalman filter (BKF) and Boolean Kalman smoother (BKS), are intractable in the case of large systems, due to computational and memory requirements. To address this, we propose approximate MMSE filtering and smoothing algorithms based on the auxiliary particle filter (APF) method from sequential Monte-Carlo theory. These algorithms are used jointly with maximum-likelihood (ML) methods for simultaneous state and parameter estimation in POBDS models. In the presence of continuous parameters, ML estimation is performed using the expectation-maximization (EM) algorithm; we develop for this purpose a special smoother which reduces the computational complexity of the EM algorithm. The resulting particle-based adaptive filter is applied to a POBDS model of Boolean gene regulatory networks observed through noisy RNA-Seq time series data, and performance is assessed through a series of numerical experiments using the well-known cell cycle gene regulatory model.
A derivative-free distributed filtering approach for sensorless control of nonlinear systems
Rigatos, Gerasimos G.
2012-09-01
This article examines the problem of sensorless control for nonlinear dynamical systems with the use of derivative-free Extended Information Filtering (EIF). The system is first subject to a linearisation transformation and next state estimation is performed by applying the standard Kalman Filter to the linearised model. At a second level, the standard Information Filter is used to fuse the state estimates obtained from local derivative-free Kalman filters running at the local information processing nodes. This approach has significant advantages because unlike the EIF (i) is not based on local linearisation of the nonlinear dynamics (ii) does not assume truncation of higher order Taylor expansion terms thus preserving the accuracy and robustness of the performed estimation and (iii) does not require the computation of Jacobian matrices. As a case study a robotic manipulator is considered and a cameras network consisting of multiple vision nodes is assumed to provide the visual information to be used in the control loop. A derivative-free implementation of the EIF is used to produce the aggregate state vector of the robot by processing local state estimates coming from the distributed vision nodes. The performance of the considered sensorless control scheme is evaluated through simulation experiments.
Directory of Open Access Journals (Sweden)
Wilton Mitsunari Takeshita
2013-01-01
Full Text Available Background: To compare the diagnostic accuracy of three different imaging systems: Direct digital radiography system (DDR-CMOS, four types of filtered images, and a priori and a posteriori registration of digital subtraction radiography (DSR in the diagnosis of proximal defects. Materials and Methods: The teeth were arranged in pairs in 10 blocks of vinyl polysiloxane, and proximal defects were performed with drills of 0.25, 0.5, and 1 mm diameter. Kodak RVG 6100 sensor was used to capture the images. A posteriori DSR registrations were done with Regeemy 0.2.43 and subtraction with Image Tool 3.0. Filtered images were obtained with Kodak Dental Imaging 6.1 software. Images (n = 360 were evaluated by three raters, all experts in dental radiology. Results: Sensitivity and specificity of the area under the receiver operator characteristic (ROC curve (Az were higher for DSR images with all three drills (Az = 0.896, 0.979, and 1.000 for drills 0.25, 0.5, and 1 mm, respectively. The highest values were found for 1-mm drills and the lowest for 0.25-mm drills, with negative filter having the lowest values of all (Az = 0.631. Conclusion: The best method of diagnosis was by using a DSR. The negative filter obtained the worst results. Larger drills showed the highest sensitivity and specificity values of the area under the ROC curve.
An Efficient Filter Banks Based Multicarrier System in Cognitive Radio Networks (invited paper
Directory of Open Access Journals (Sweden)
H. Zhang
2010-12-01
Full Text Available In cognitive radio techniques, OFDM is usually regarded as the physical layer candidate. However, the weaknesses of the OFDM technique, i.e., using plain FFT for spectral analysis , decreased bandwidth efficiency due to CP (cyclic prefix, high out-of-band emission, have been pointed out and the introduction of filter banks based multicarrier (FBMC system has been advocated by a number of authors. In this paper, we propose an efficient FBMC system for cognitive radio network. At the transmitter, we propose a decimation transform decomposition method to eliminate the unnecessary zero operations. At the receiver, we utilize the analysis filter banks to sense the spectrum bands. In order to conquer the shortages of the traditional filter banks, we propose a multistage analysis filter banks, which can reduce the computational complexity while improve the detection precision when used to sense the spectrum bands. And with an adaptive threshold scheme in the power estimator, the threshold can be kept very close to the noise power, which can increase the detection probability especially in the condition of low SNR.
Directory of Open Access Journals (Sweden)
Shaoxing Hu
2015-11-01
Full Text Available Aiming at addressing the problem of high computational cost of the traditional Kalman filter in SINS/GPS, a practical optimization algorithm with offline-derivation and parallel processing methods based on the numerical characteristics of the system is presented in this paper. The algorithm exploits the sparseness and/or symmetry of matrices to simplify the computational procedure. Thus plenty of invalid operations can be avoided by offline derivation using a block matrix technique. For enhanced efficiency, a new parallel computational mechanism is established by subdividing and restructuring calculation processes after analyzing the extracted “useful” data. As a result, the algorithm saves about 90% of the CPU processing time and 66% of the memory usage needed in a classical Kalman filter. Meanwhile, the method as a numerical approach needs no precise-loss transformation/approximation of system modules and the accuracy suffers little in comparison with the filter before computational optimization. Furthermore, since no complicated matrix theories are needed, the algorithm can be easily transplanted into other modified filters as a secondary optimization method to achieve further efficiency.
Hu, Shaoxing; Xu, Shike; Wang, Duhu; Zhang, Aiwu
2015-11-11
Aiming at addressing the problem of high computational cost of the traditional Kalman filter in SINS/GPS, a practical optimization algorithm with offline-derivation and parallel processing methods based on the numerical characteristics of the system is presented in this paper. The algorithm exploits the sparseness and/or symmetry of matrices to simplify the computational procedure. Thus plenty of invalid operations can be avoided by offline derivation using a block matrix technique. For enhanced efficiency, a new parallel computational mechanism is established by subdividing and restructuring calculation processes after analyzing the extracted "useful" data. As a result, the algorithm saves about 90% of the CPU processing time and 66% of the memory usage needed in a classical Kalman filter. Meanwhile, the method as a numerical approach needs no precise-loss transformation/approximation of system modules and the accuracy suffers little in comparison with the filter before computational optimization. Furthermore, since no complicated matrix theories are needed, the algorithm can be easily transplanted into other modified filters as a secondary optimization method to achieve further efficiency.
Modelling and measurement of wear particle flow in a dual oil filter system for condition monitoring
DEFF Research Database (Denmark)
Henneberg, Morten; Eriksen, René Lynge; Fich, Jens
2016-01-01
Wear debris is an indicator of the health of machinery, and the availability of accurate methods for characterising debris is important. In this work, a dual filter model for a gear oil system is used in conjunction with operational data to indicate three different system operating states. The qu...... particle generation is made possible by model parameter estimation and identification of an unintended lack of filter change. The model may also be used to optimise system and filtration performance, and to enable continuous condition monitoring.......Wear debris is an indicator of the health of machinery, and the availability of accurate methods for characterising debris is important. In this work, a dual filter model for a gear oil system is used in conjunction with operational data to indicate three different system operating states....... The quantity of wear particles in gear oil is analysed with respect to system running conditions. It is shown that the model fits the data in terms of startup “particle burst” phenomenon, quasi-stationary conditions during operation, and clean-up filtration when placed out of operation. In order to establish...
An R-peak detection method that uses an SVD filter and a search back system.
Jung, Woo-Hyuk; Lee, Sang-Goog
2012-12-01
In this paper, we present a method for detecting the R-peak of an ECG signal by using an singular value decomposition (SVD) filter and a search back system. The ECG signal was detected in two phases: the pre-processing phase and the decision phase. The pre-processing phase consisted of the stages for the SVD filter, Butterworth High Pass Filter (HPF), moving average (MA), and squaring, whereas the decision phase consisted of a single stage that detected the R-peak. In the pre-processing phase, the SVD filter removed noise while the Butterworth HPF eliminated baseline wander. The MA removed the remaining noise of the signal that had gone through the SVD filter to make the signal smooth, and squaring played a role in strengthening the signal. In the decision phase, the threshold was used to set the interval before detecting the R-peak. When the latest R-R interval (RRI), suggested by Hamilton et al., was greater than 150% of the previous RRI, the method of detecting the R-peak in such an interval was modified to be 150% or greater than the smallest interval of the two most latest RRIs. When the modified search back system was used, the error rate of the peak detection decreased to 0.29%, compared to 1.34% when the modified search back system was not used. Consequently, the sensitivity was 99.47%, the positive predictivity was 99.47%, and the detection error was 1.05%. Furthermore, the quality of the signal in data with a substantial amount of noise was improved, and thus, the R-peak was detected effectively. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Automatic balancing of AMB systems using plural notch filter and adaptive synchronous compensation
Xu, Xiangbo; Chen, Shao; Zhang, Yanan
2016-07-01
To achieve automatic balancing in active magnetic bearing (AMB) system, a control method with notch filters and synchronous compensators is widely employed. However, the control precision is significantly affected by the synchronous compensation error, which is caused by parameter errors and variations of the power amplifiers. Furthermore, the computation effort may become intolerable if a 4-degree-of-freedom (dof) AMB system is studied. To solve these problems, an adaptive automatic balancing control method in the AMB system is presented in this study. Firstly, a 4-dof radial AMB system is described and analyzed. To simplify the controller design, the 4-dof dynamic equations are transferred into two plural functions related to translation and rotation, respectively. Next, to achieve automatic balancing of the AMB system, two synchronous equations are formed. Solution of them leads to a control strategy based on notch filters and feedforward controllers with an inverse function of the power amplifier. The feedforward controllers can be simplified as synchronous phases and amplitudes. Then, a plural phase-shift notch filter which can identify the synchronous components in 2-dof motions is formulated, and an adaptive compensation method that can form two closed-loop systems to tune the synchronous amplitude of the feedforward controller and the phase of the plural notch filter is proposed. Finally, the proposed control strategy is verified by both simulations and experiments on a test rig of magnetically suspended control moment gyro. The results indicate that this method can fulfill the automatic balancing of the AMB system with a light computational load.
Ikeda, Takeshi; Kawamoto, Mitsuru; Sashima, Akio; Suzuki, Keiji; Kurumatani, Koichi
In the field of the ubiquitous computing, positioning systems which can provide users' location information have paid attention as an important technical element which can be applied to various services, for example, indoor navigation services, evacuation services, market research services, guidance services, and so on. A lot of researchers have proposed various outdoor and indoor positioning systems. In this paper, we deal with indoor positioning systems. Many conventional indoor positioning systems use expensive infrastructures, because the propagated times of radio waves are used to measure users' positions with high accuracy. In this paper, we propose an indoor autonomous positioning system using radio signal strengths (RSSs) based on ISM band communications. In order to estimate users' positions, the proposed system utilizes a particle filter that is one of the Monte Carlo methods. Because the RSS information is used in the proposed system, the equipments configuring the system are not expensive compared with the conventional indoor positioning systems and it can be installed easily. Moreover, because the particle filter is used to estimate user's position, even if the RSS fluctuates due to, for example, multi-paths, the system can carry out position estimation robustly. We install the proposed system in one floor of a building and carry out some experiments in order to verify the validity of the proposed system. As a result, we confirmed that the average of the estimation errors of the proposed system was about 1.8 m, where the result is enough accuracy for achieving the services mentioned above.
Implementation of Autofocus in Alignment System for Layered Imprint Fabrication
Institute of Scientific and Technical Information of China (English)
WANG Quandai; DUAN Yugang; LU Bingheng; XIANG Jiawei; YANG Lianfa
2009-01-01
Autofocus method based on the analysis of image content information is investigated to reduce the alignment error resulting from mark positioning uncertainty due to defocus in microstructure layered fabrication process based on multilevel imprint lithography, The applicability of several autofocus functions to the alignment mark images is evaluated concerning their uniformity, sharpness near peak, reliability and measure computation efficiency and the most suitable one based on power spectrum in frequency domain (PSFD) is adopted. To solve the problem of too much computation amount needed in PSFD algorithm, the strategy of interested region detection and effective image reconstruction is proposed and the algorithm efficiency is improved. The test results show that the computation time is reduced from 0.316 s to 0.023 s under the same conditions while the other merits of the function are preserved, which indicates that the modified algorithm can meet the mark image autofocusing require-ments in response time, accuracy and robustness. The alignment error due to defocus which is about 0.5 μm indi-cated by experimental results can be reduced or eliminated by the autofocusing implementation.
A New Subband Adaptive Filtering Algorithm for Sparse System Identification with Impulsive Noise
Directory of Open Access Journals (Sweden)
Young-Seok Choi
2014-01-01
Full Text Available This paper presents a novel subband adaptive filter (SAF for system identification where an impulse response is sparse and disturbed with an impulsive noise. Benefiting from the uses of l1-norm optimization and l0-norm penalty of the weight vector in the cost function, the proposed l0-norm sign SAF (l0-SSAF achieves both robustness against impulsive noise and remarkably improved convergence behavior more than the classical adaptive filters. Simulation results in the system identification scenario confirm that the proposed l0-norm SSAF is not only more robust but also faster and more accurate than its counterparts in the sparse system identification in the presence of impulsive noise.
Packet Format Design and Decision Directed Tracking Methods for Filter Bank Multicarrier Systems
Amini, Peiman; Farhang-Boroujeny, Behrouz
2010-12-01
Packetized data transmission is commonly used in wireless communication systems. Each packet starts with a preamble which is used to synchronize the receiver with carrier frequency of the incoming signal, to find a good timing phase, and to identify the channel impulse response or to adjust a set of channel equalizer parameters. In this paper, following the same philosophy, we develop a packet format for multicarrier systems that operate based on filter banks, filter bank multicarrier (FBMC) systems. The related algorithms for carrier frequency and timing recovery as well as channel identification/equalizer adjustment and methods for carrier and timing tracking loops are proposed. The proposed ideas are evaluated and their satisfactory performance are presented through computer simulations.
Packet Format Design and Decision Directed Tracking Methods for Filter Bank Multicarrier Systems
Directory of Open Access Journals (Sweden)
Amini Peiman
2010-01-01
Full Text Available Packetized data transmission is commonly used in wireless communication systems. Each packet starts with a preamble which is used to synchronize the receiver with carrier frequency of the incoming signal, to find a good timing phase, and to identify the channel impulse response or to adjust a set of channel equalizer parameters. In this paper, following the same philosophy, we develop a packet format for multicarrier systems that operate based on filter banks, filter bank multicarrier (FBMC systems. The related algorithms for carrier frequency and timing recovery as well as channel identification/equalizer adjustment and methods for carrier and timing tracking loops are proposed. The proposed ideas are evaluated and their satisfactory performance are presented through computer simulations.
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.
Directory of Open Access Journals (Sweden)
Shaharudin Nuraida
2017-01-01
Full Text Available An adequate supply of safe drinking water is one of major ways to obtain healthy life. Water filter system is one way to improve the water quality. However, to maintain the performance of the system, it need to undergo the maintenance service. This study evaluate the requirement of maintenance service in water filter system. Water quality was measured before and after maintenance service. Parameters measured were pH, turbidity, residual chlorine, nitrate and heavy metals and these parameters were compared with National Drinking Water Quality Standards. Collection of data were involved three housing areas in Johor. The quality of drinking water from water filter system were analysed using pH meter, turbidity meter, DR6000 and Inductively Coupled Plasma-Mass Spectrometer. pH value was increased from 16.4% for before maintenance services to 30.7% for after maintenance service. Increment of removal percentage for turbidity, residual chlorine and nitrate after maintenance were 21.5, 13.6 and 26.7, respectively. This result shows that maintenance service enhance the performance of the system. However, less significant of maintenance service for enhance the removal of heavy metals which the increment of removal percentage in range 0.3 to 9.8. Only aluminium shows percentage removal for after maintenance with 92.8% lower compared to before maintenance service with 95.5%.
Fabrication of recyclable superhydrophobic cotton fabrics
Han, Sang Wook; Park, Eun Ji; Jeong, Myung-Geun; Kim, Il Hee; Seo, Hyun Ook; Kim, Ju Hwan; Kim, Kwang-Dae; Kim, Young Dok
2017-04-01
Commercial cotton fabric was coated with SiO2 nanoparticles wrapped with a polydimethylsiloxane (PDMS) layer, and the resulting material surface showed a water contact angle greater than 160°. The superhydrophobic fabric showed resistance to water-soluble contaminants and maintained its original superhydrophobic properties with almost no alteration even after many times of absorption-washing cycles of oil. Moreover, superhydrophobic fabric can be used as a filter to separate oil from water. We demonstrated a simple method of fabrication of superhydrophobic fabric with potential interest for use in a variety of applications.
COMPARATIVE STUDY OF DIFFERENT KALMAN FILTER IMPLEMENTATIONS IN POWER SYSTEM STABILITY
Directory of Open Access Journals (Sweden)
H. H. Goh
2014-01-01
Full Text Available Voltage stability and voltage collapse issues have in recent years begun to constitute an unpleasant warning to the operational security of power systems. Many techniques have been investigated in order to predict the point of voltage collapse. However, there are still several restrictions due to the insufficiency of current system state information. Accompanied by the commencement of the Phasor Measurement Units (PMUs evolving technology, it donates a solution to enhance the existing power system state estimation. In consequence, the significances to develop preferable methods that would provide a preliminary warning before the voltage collapse had grabbed the attention. This study covers the forming of real-time system monitoring methods that able to provide a timely warning in the power system. The algorithms used to estimate the points of collapse are according to the theory that voltage instability is approximately linked to the maximum load ability of a transmission network. As a result, the critical operating conditions (peak of maximum deliverable power come when the system Thevenin impedance is equal to the load impedance. This study focuses specifically on research about the motivation and the application of different Kalman filter implementations such as Discrete Kalman Filter (DKF, Extended Kalman Filter (EKF and Unscented Kalman Filter (UKF are used to track the Thevenin parameters. Therefore, the implications of this research paper are to determine the robustness and reliability of the proposed tracking methods. As compared to previous studies, the tracking process is just mainly focused on DKF method only, while the novelty throughout this study is to compare the performances and efficiencies of different Kalman filters in determining the maximum load ability on the 2 different types of test systems. Accompanying, the parameters are utilized in real-time voltage instability estimator to discover the current system’s condition
RD on 3D Sensors and Micro‐Fabricated Detector Systems
Da Via, C; Dalla Betta, GF
2013-01-01
The aim of this proposed R&D Collaboration is the design, fabrication and industrialization of a new generation of low mass detector systems based on silicon micro‐fabrication techniques. The main objective is the verification and validation of such systems for LHC detector upgrades. In particular, the collaboration would like to focus on the following research topics: • Novel 3D sensors layouts, with enhanced signal properties, high speed and active edges. • Integrated micro‐channel cooling for effective low mass module thermal management. • System integration and fully sensitive large area coverage.
Filtering and fault tolerant control of parameter-varying time-delay systems and applications
Mohammadpour Velni, Javad
This dissertation addresses some open problems in control systems theory. The problems considered include the dynamic controller and filter design for Linear Parameter Varying (LPV) time-delay systems, the reconfigurable control design in Fault Tolerant Control Systems (FTCS) and fault diagnostics in Diesel engines. In the first part of this thesis, we investigate the problem of designing parameter-dependent filters for output estimation of LPV time-delay systems. The filters are designed such that the filtering error system guarantees an optimum level of H2 or Hinfinity performance. A state-delay term is included in the filter dynamics to reduce the design conservatism and improve the performance. The Linear Matrix Inequality (LMI)-based synthesis conditions developed for the filter design purposes are categorized into the rate-dependent and delay-dependent conditions which could handle the time-varying state-delay and bounded small delay cases, respectively. Among these two, the latter one is shown to provide a significant reduction in the conservativeness in the filter design. The second part of the thesis examines the analysis and synthesis of Fault Tolerant Control (FTC) systems in an LPV framework. For reconfigurable control design purposes, the information from Fault Detection and Isolation (FDI) module, that provides an estimate of the fault parameters, is utilized to schedule the controller matrices. We will also present a formulation that incorporates the factor of detection delay in the FTC supervisory system. It is shown that including this delay in the synthesis conditions leads to improved performance and reduced control effort. For analysis of the FTC systems including time-delay, where the fault parameters might be identified inaccurately, we first introduce the notion of brief instability for LPV time-delay systems. In these systems it is possible that the output trajectory converges to zero even though there are parameter trajectories for which
Nonlinear Control of Back-to-Back VSC-HVDC System via Command-Filter Backstepping
Directory of Open Access Journals (Sweden)
Jie Huang
2017-01-01
Full Text Available This paper proposed a command-filtered backstepping controller to improve the dynamic performance of back-to-back voltage-source-converter high voltage direct current (BTB VSC-HVDC. First, the principle and model of BTB VSC-HVDC in abc and d-q frame are described. Then, backstepping method is applied to design a controller to maintain the voltage balance and realize coordinated control of active and reactive power. Meanwhile, command filter is introduced to deal with the problem of input saturation and explosion of complexity in conventional backstepping, and a filter compensation signal is designed to diminish the adverse effects caused by the command filter. Next, the stability and convergence of the whole system are proved via the Lyapunov theorem of asymptotic stability. Finally, simulation results are given to demonstrate that proposed controller has a better dynamic performance and stronger robustness compared to the traditional PID algorithm, which also proves the effectiveness and possibility of the designed controller.
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.
Energy Technology Data Exchange (ETDEWEB)
McWilliams, T.; Widdoes, Jr., L. C.; Wood, L.
1976-09-30
The design of an extremely high performance programmable digital filter of novel architecture, the LLL Programmable Digital Filter, is described. The digital filter is a high-performance multiprocessor having general purpose applicability and high programmability; it is extremely cost effective either in a uniprocessor or a multiprocessor configuration. The architecture and instruction set of the individual processor was optimized with regard to the multiple processor configuration. The optimal structure of a parallel processing system was determined for addressing the specific Navy application centering on the advanced digital filtering of passive acoustic ASW data of the type obtained from the SOSUS net. 148 figures. (RWR)
Fir Filter Design Using The Signed-Digit Number System and Carry Save Adders – A Comparison
Directory of Open Access Journals (Sweden)
Hesham Altwaijry
2013-01-01
Full Text Available This work looks at optimizing finite impulse response (FIR filters from an arithmetic perspective. Since the main two arithmetic operations in the convolution equations are addition and multiplication, they are the targets of the optimization. Therefore, considering carry-propagate-free addition techniques should enhance the addition operation of the filter. The signed-digit number system is utilized to speedup addition in the filter. An alternative carry propagate free fast adder, carry-save adder, is also used here to compare its performance to the signed-digit adder. For multiplication, Booth encoding is used to reduce the number of partial products. The two filters are modeled in VHDL, synthesized and place-and-routed. The filters are deployed on a development board to filter digital images. The resultant hardware is analyzed for speed and logic utilization
An OTA-C filter for ECG acquisition systems with highly linear range and less passband attenuation
Jihai, Duan; Chuang, Lan; Weilin, Xu; Baolin, Wei
2015-05-01
A fifth order operational transconductance amplifier-C (OTA-C) Butterworth type low-pass filter with highly linear range and less passband attenuation is presented for wearable bio-telemetry monitoring applications in a UWB wireless body area network. The source degeneration structure applied in typical small transconductance circuit is improved to provide a highly linear range for the OTA-C filter. Moreover, to reduce the passband attenuation of the filter, a cascode structure is employed as the output stage of the OTA. The OTA-based circuit is operated in weak inversion due to strict power limitation in the biomedical chip. The filter is fabricated in a SMIC 0.18-μm CMOS process. The measured results for the filter have shown a passband gain of -6.2 dB, while the -3-dB frequency is around 276 Hz. For the 0.8 VPP sinusoidal input at 100 Hz, a total harmonic distortion (THD) of -56.8 dB is obtained. An electrocardiogram signal with noise interference is fed into this chip to validate the function of the designed filter. Project supported by the National Natural Science Foundation of China (Nos. 61161003, 61264001, 61166004) and the Guangxi Natural Science Foundation (No. 2013GXNSFAA019333).