WorldWideScience

Sample records for infrared electro-magnetic filters

  1. A Hybrid Extended Kalman Filter as an Observer for a Pot-Electro-Magnetic Actuator

    Science.gov (United States)

    Schmidt, Simon; Mercorelli, Paolo

    2017-01-01

    This paper deals with an application in which a hybrid extended Kalman Filter (HEKF) is used to estimate state variables in a U-shaped electro-magnetic actuator to be used in mechanical systems. In this context a hybrid Kalman Filter is the one which switches between different models. The paper proposes a hybrid model for an extended Kalman Filter to be used as an observer to estimate the state and to control the force of the actuator. Applications include position, velocity and force control in automotive, engine and manufacturing systems. This work is focused on the estimation of state variables of the actuator. Simulated results show the effectiveness of the proposed approach.

  2. Minimally Invasive Electro-Magnetic Navigational Bronchoscopy-Integrated Near-Infrared-Guided Sentinel Lymph Node Mapping in the Porcine Lung

    Science.gov (United States)

    Wada, Hironobu; Hirohashi, Kentaro; Anayama, Takashi; Nakajima, Takahiro; Kato, Tatsuya; Chan, Harley H. L.; Qiu, Jimmy; Daly, Michael; Weersink, Robert; Jaffray, David A.; Irish, Jonathan C.; Waddell, Thomas K.; Keshavjee, Shaf; Yoshino, Ichiro; Yasufuku, Kazuhiro

    2015-01-01

    Background The use of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) for sentinel lymph node (SN) mapping has been investigated in lung cancer; however, this has not been fully adapted for minimally invasive surgery (MIS). The aim of our study was to develop a minimally invasive SN mapping integrating pre-operative electro-magnetic navigational bronchoscopy (ENB)-guided transbronchial ICG injection and intraoperative NIR thoracoscopic imaging. Methods A NIR thoracoscope was used to visualize ICG fluorescence. ICG solutions in a 96-well plate and ex vivo porcine lungs were examined to optimize ICG concentrations and injection volumes. Transbronchial ICG injection (n=4) was assessed in comparison to a traditional transpleural approach (n=3), where after thoracotomy an ICG solution (100μL at 100μg/mL) was injected into the porcine right upper lobe for SN identification. For further translation into clinical use, transbronchial ICG injection prior to thoracotomy followed by NIR thoracoscopic imaging was validated (n=3). ENB was used for accurate targeting in two pigs with a pseudo-tumor. Results The ICG fluorescence at 10 μg/mL was the brightest among various concentrations, unchanged by the distance between the thoracoscope and ICG solutions. Injected ICG of no more than 500μL showed a localized fluorescence area. All 7 pigs showed a bright paratracheal lymph node within 15 minutes post-injection, with persistent fluorescence for 60 minutes. The antecedent transbronchial ICG injection succeeded in SN identification in all 3 cases at the first thoracoscopic inspection within 20 minutes post-injection. The ENB system allowed accurate ICG injection surrounding the pseudo-tumors. Conclusions ENB-guided ICG injection followed by NIR thoracoscopy was technically feasible for SN mapping in the porcine lung. This promising platform may be translated into human clinical trials and is suited for MIS. PMID:25993006

  3. Minimally invasive electro-magnetic navigational bronchoscopy-integrated near-infrared-guided sentinel lymph node mapping in the porcine lung.

    Directory of Open Access Journals (Sweden)

    Hironobu Wada

    Full Text Available The use of near-infrared (NIR fluorescence imaging with indocyanine green (ICG for sentinel lymph node (SN mapping has been investigated in lung cancer; however, this has not been fully adapted for minimally invasive surgery (MIS. The aim of our study was to develop a minimally invasive SN mapping integrating pre-operative electro-magnetic navigational bronchoscopy (ENB-guided transbronchial ICG injection and intraoperative NIR thoracoscopic imaging.A NIR thoracoscope was used to visualize ICG fluorescence. ICG solutions in a 96-well plate and ex vivo porcine lungs were examined to optimize ICG concentrations and injection volumes. Transbronchial ICG injection (n=4 was assessed in comparison to a traditional transpleural approach (n=3, where after thoracotomy an ICG solution (100 μL at 100 μg/mL was injected into the porcine right upper lobe for SN identification. For further translation into clinical use, transbronchial ICG injection prior to thoracotomy followed by NIR thoracoscopic imaging was validated (n=3. ENB was used for accurate targeting in two pigs with a pseudo-tumor.The ICG fluorescence at 10 μg/mL was the brightest among various concentrations, unchanged by the distance between the thoracoscope and ICG solutions. Injected ICG of no more than 500μ L showed a localized fluorescence area. All 7 pigs showed a bright paratracheal lymph node within 15 minutes post-injection, with persistent fluorescence for 60 minutes. The antecedent transbronchial ICG injection succeeded in SN identification in all 3 cases at the first thoracoscopic inspection within 20 minutes post-injection. The ENB system allowed accurate ICG injection surrounding the pseudo-tumors.ENB-guided ICG injection followed by NIR thoracoscopy was technically feasible for SN mapping in the porcine lung. This promising platform may be translated into human clinical trials and is suited for MIS.

  4. Micro-gravity Isolation using only Electro-magnetic Actuators

    DEFF Research Database (Denmark)

    Vinther, D.; Alminde, Lars; Bisgaard, Morten;

    in the Sixth Student Parabolic Flight Campaign issued by the European Space Agency (ESA). The system consists of six custom made electro magnetic actuators which acts on the isolated platform based on the designed controller and their input from six accelerometers and six infrared position sensors. From......In this paper the design, construction and test of a free floating micro-gravity isolation platform to reduce the acceleration dose on zero gravity experiments on e.g. the International Space Station (ISS) is discussed. During the project a system is specified and constructed whereupon it is tested...

  5. Micro-gravity Isolation using only Electro-magnetic Actuators

    DEFF Research Database (Denmark)

    Vinther, D.; Alminde, Lars; Bisgaard, Morten

    2004-01-01

    In this paper the design, construction and test of a free floating micro-gravity isolation platform to reduce the acceleration dose on zero gravity experiments on e.g. the International Space Station (ISS) is discussed. During the project a system is specified and constructed whereupon it is tested...... in the Sixth Student Parabolic Flight Campaign issued by the European Space Agency (ESA). The system consists of six custom made electro magnetic actuators which acts on the isolated platform based on the designed controller and their input from six accelerometers and six infrared position sensors. >From...

  6. Mesoporous Silicon Far Infrared Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make optical filters based on mesoporous silicon multilayers, for use at cold temperatures in the far infrared...

  7. Noise suppression during the electro-magnetic acoustic detection of wheels tread defects

    Science.gov (United States)

    Zhou, Xiaohong; Dai, Lixin; Yang, Kai; Wang, Li

    2010-08-01

    Electro-magnetic acoustic detection technique has become a new development trend of nondestructive testing because of its high detection efficiency, accurate detection results, etc, so it now has been widely adopted in the railway department of our country. When the signal is detected using electro-magnetic acoustic detection technique, the influence of the poor condition of wheel surface, the existing electromagnetic interference and other factors will enable different levels of noise to exist in the detected signal, which will affect the signal quality, thereby reducing the detection accuracy. After introducing the structure and principle of electro-magnetic acoustic detection system, this paper has put forward two noise suppression algorithms for the noise problem of the detection signal, namely, phase difference algorithm and adaptive filtering algorithm. On the premise of reserving the necessary signal waveform of system, the algorithms can effectively suppress the noise of a detected signal, improve the quality of a data waveform, and obtain good detection results. The paper also compares two algorithms and points out that the better detection accuracy can be obtained if combining the two algorithms. This work has certain inspiration to raise the accuracy of electro-magnetic acoustic detection results.

  8. Electro-Magnetic Quadrupole Magnets in the LCLS FEL Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Emma, P.

    2005-01-31

    We discuss various aspects of electro-magnetic quadrupole (EMQ) magnets for the LCLS FEL undulator, including their utility in beam-based alignment (BBA), magnet design issues, and impact on tunnel environment, reliability, and cost.

  9. Using quantum filters as edge detectors in infrared images

    Science.gov (United States)

    Bolaños Marín, Daniela

    2014-06-01

    Some new filters inspired in quantum models are used as edge detectors in infrared images. In this case, Bessel, Hermite and Morse filters will be applied to detect edges and fibrillar structures in infrared images. The edge detectors will be built by the Laplacian of the mentioned quantum filters. Furthermore, using curvature operators, curvature detectors and amplifiers of contrast will be constructed to analyze infrared images. The quantum filter prototyping will be done using computer algebra software, specifically Maple and its package, ImageTools. The quantum filters will be applied to infrared images using the technique of convolutions and blurred derivatives. It is expected that designed quantum filters will be useful for analysis and processing of infrared images. As future investigations, we propose to design plugins with the quantum filters that can be incorporated into the program ImageJ, which will facilitate the use of the quantum filters for the infrared image processing.

  10. Research on Electro-Magnetic Environment of UHV Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Employing even higher voltage level to promote power transmission economy is an important subject in the program of power transmission from west to east. The influence of electro-magnetic environment of transmission project being closely related with human health and construction cost has to be seriously considered before advancing transmission voltage. This paper analyzes and discusses overseas and domestic research achievements on radio interference, audible noise, power frequency electric field, power frequency magnetic fields, DC resultant field intensity and ion stream involved in power transmission at ultra-high-voltage (UHV)AC and ± 800 kV DC or even higher voltage levels. Suggestions on limiting electro-magnetic effects and their ceiling value as well as measures to improve electro-magnetic environment are put forward.

  11. Improved multilevel filters to enhance infrared small target

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Wang; Tianxu Zhang; Luxin Yan; Man Wang; Jiawei Wu

    2011-01-01

    We propose improved multilevel filters (IMLFs) involving the absolute value operation into the algorithmic framework of traditional multilevel filters (MLFs) to improve the robustness of infrared small target enhancement techniques under a complex infrared cluttered background. Compared with the widely used small target enhancement methods which only deal with bright targets, the proposed technique can enhance the infrared small target, whether it is bright or dark. Experimental results verify that the proposed technique is efficient and practical.%@@ We propose improved multilevel filters (IMLFs) involving the absolute value operation into the algorithmic framework of traditional multilevel filters (MLFs) to improve the robustness of infrared small target enhancement techniques under a complex infrared cluttered background.Compared with the widely used small target enhancement methods which only deal with bright targets, the proposed technique can enhance the infrared small target, whether it is bright or dark.Experimental results verify that the proposed technique is efficient and practical.

  12. Novel averaging window filter for SIFT in infrared face recognition

    Institute of Scientific and Technical Information of China (English)

    Junfeng Bai; Yong Ma; Jing Li; Fan Fan; Hongyuan Wang

    2011-01-01

    The extraction of stable local features directly affects the performance of infrared face recognition algorithms. Recent studies on the application of scale invariant feature transform (SIFT) to infrared face recognition show that star-styled window filter (SWF) can filter out errors incorrectly introduced by SIFT. The current letter proposes an improved filter pattern called Y-styled window filter (YWF) to further eliminate the wrong matches. Compared with SWF, YWF patterns are sparser and do not maintain rotation invariance; thus, they are more suitable to infrared face recognition. Our experimental results demonstrate that a YWF-based averaging window outperforms an SWF-based one in reducing wrong matches, therefore improving the reliability of infrared face recognition systems.%@@ The extraction of stable local features directly affects the performance of infrared face recognition algorithms.Recent studies on the application of scale invariant feature transform(SIFT) to infrared face recognition show that star-styled window filter(SWF) can filter out errors incorrectly introduced by SIFT.

  13. Si-based infrared optical filters

    Science.gov (United States)

    Balčytis, Armandas; Ryu, Meguya; Seniutinas, Gediminas; Nishijima, Yoshiaki; Hikima, Yuta; Zamengo, Massimiliano; Petruškevičius, Raimondas; Morikawa, Junko; Juodkazis, Saulius

    2015-12-01

    Pyramidal silicon nanospikes, termed black-Si (b-Si), with controlled height of 0.2 to 1 μm, were fabricated by plasma etching over 3-in wafers and were shown to act as variable density filters in a wide range of the IR spectrum 2.5 to 20 μm, with transmission and its spectral gradient dependent on the height of the spikes. Such variable density IR filters can be utilized for imaging and monitoring applications. Narrow IR notch filters were realized with gold mesh arrays on Si wafers prospective for applications in surface-enhanced IR absorption sensing and "cold materials" for heat radiation into atmospheric IR transmission window. Both types of filters for IR: spectrally variable and notch are made by simple fabrication methods.

  14. Mesoporous Silicon Far Infrared Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make optical filters based on mesoporous silicon multilayers, for use at cold temperatures in the far...

  15. Infrared Reflective Filter and Its Applications

    Science.gov (United States)

    Honda, Kiyokazu; Ishizaki, Ariyoshi; Yuge, Youji; Saitoh, Tokuyoshi

    1983-12-01

    A thin film, which reflects infra-red ray while transmits visible light, is discussed in a background of energy saving incandescent lamps. The film which consists of multi-layer Ti02-Si02 film reflects infra-red ray effectively and has a high heat resistance. This film is formed from organometallic solutions by dipping method. In order to carry out multi-layer coatings, the organometallic solutions are improved. A film on a substrate turns into a metalic oxide film having desired optical thickness and refractive index. The optical properties of this film and its application to tubular tungsten halogen lamps are discussed in this paper.

  16. Measurement of Spatial Filtering Capabilities of Single Mode Infrared Fibers

    Science.gov (United States)

    Ksendzov, Alexander; Bloemhof, E.; White, V.; Wallace, J. K.; Gappinger, R. O.; Sanghera, J. S.; Busse, L. E.; Kim, W. J.; Pureza, P. C.; Nguyen, V. Q.; hide

    2006-01-01

    Spatial filtering is necessary to achieve deep nulls in optical interferometer and single mode infrared fibers can serve as spatial filters. The filtering function is based on the ability of these devices to perform the mode-cleaning function: only the component of the input field that is coupled to the single bound (fundamental) mode of the device propagates to the output without substantial loss. In practical fiber devices, there are leakage channels that cause light not coupled into the fundamental mode to propagate to the output. These include propagation through the fiber cladding and by means of a leaky mode. We propose a technique for measuring the magnitude of this leakage and apply it to infrared fibers made at the Naval Research Laboratory and at Tel Aviv University.

  17. Target tracking in infrared imagery using a novel particle filter

    Institute of Scientific and Technical Information of China (English)

    Fanglin Wang; Erqi Liu; Jie Yang; Shengyang Yu; Yue Zhou

    2009-01-01

    To address two challenging problems in infrared target tracking, target appearance changes and unpre-dictable abrupt motions, a novel particle filtering based tracking algorithm is introduced. In this method, a novel saliency model is proposed to distinguish the salient target from background, and the eigenspace model is invoked to adapt target appearance changes. To account for the abrupt motions efficiently, a two-step sampling method is proposed to combine the two observation models. The proposed tracking method is demonstrated through two real infrared image sequences, which include the changes of luminance and size, and the drastic abrupt motions of the target.

  18. Design and fabrication of long wave infrared spectral filters

    Science.gov (United States)

    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.

  19. Detail Enhancement for Infrared Images Based on Propagated Image Filter

    Directory of Open Access Journals (Sweden)

    Yishu Peng

    2016-01-01

    Full Text Available For displaying high-dynamic-range images acquired by thermal camera systems, 14-bit raw infrared data should map into 8-bit gray values. This paper presents a new method for detail enhancement of infrared images to display the image with a relatively satisfied contrast and brightness, rich detail information, and no artifacts caused by the image processing. We first adopt a propagated image filter to smooth the input image and separate the image into the base layer and the detail layer. Then, we refine the base layer by using modified histogram projection for compressing. Meanwhile, the adaptive weights derived from the layer decomposition processing are used as the strict gain control for the detail layer. The final display result is obtained by recombining the two modified layers. Experimental results on both cooled and uncooled infrared data verify that the proposed method outperforms the method based on log-power histogram modification and bilateral filter-based detail enhancement in both detail enhancement and visual effect.

  20. Cryogenic filter wheel design for an infrared instrument

    Science.gov (United States)

    Azcue, Joaquín.; Villanueva, Carlos; Sánchez, Antonio; Polo, Cristina; Reina, Manuel; Carretero, Angel; Torres, Josefina; Ramos, Gonzalo; Gonzalez, Luis M.; Sabau, Maria D.; Najarro, Francisco; Pintado, Jesús M.

    2014-09-01

    In the last two decades, Spain has built up a strong IR community which has successfully contributed to space instruments, reaching Co-PI level in the SPICA mission (Space Infrared Telescope for Cosmology and Astrophysics). Under the SPICA mission, INTA, focused on the SAFARI instrument requirements but highly adaptable to other missions has designed a cryogenic low dissipation filter wheel with six positions, taking as starting point the past experience of the team with the OSIRIS instrument (ROSETTA mission) filter wheels and adapting the design to work at cryogenic temperatures. One of the main goals of the mechanism is to use as much as possible commercial components and test them at cryogenic temperature. This paper is focused on the design of the filter wheel, including the material selection for each of the main components of the mechanism, the design of elastic mount for the filter assembly, a positioner device designed to provide positional accuracy and repeatability to the filter, allowing the locking of the position without dissipation. In order to know the position of the wheel on every moment a position sensor based on a Hall sensor was developed. A series of cryogenic tests have been performed in order to validate the material configuration selected, the ball bearing lubrication and the selection of the motor. A stepper motor characterization campaign was performed including heat dissipation measurements. The result is a six position filter wheel highly adaptable to different configurations and motors using commercial components. The mechanism was successfully tested at INTA facilities at 20K at breadboard level.

  1. Nanomechanical Infrared Spectroscopy with Vibrating Filters for Pharmaceutical Analysis

    DEFF Research Database (Denmark)

    Kurek, Maksymilian; Carnoy, Matthias; Larsen, Peter Emil

    2017-01-01

    Standard infrared spectroscopy techniques are well-developed and widely used. However, they typically require milligrams of sample and can involve time-consuming sample preparation. A promising alternative is represented by nanomechanical infrared spectroscopy (NAM-IR) based on the photothermal...... response of a nanomechanical resonator, which enables the chemical analysis of picograms of analyte directly from a liquid solution in only a few minutes. Herein, we present NAM-IR using perforated membranes (filters). The method was tested with the pharmaceutical compound indomethacin to successfully...... perform a chemical and morphological analysis on roughly 100 pg of sample. With an absolute estimated sensitivity of 109±15 fg, the presented method is suitable for ultrasensitive vibrational spectroscopy....

  2. Numerical analysis of high strain rate failure of electro-magnetically loaded steel sheets

    Directory of Open Access Journals (Sweden)

    Erice Borja

    2015-01-01

    Full Text Available Electro-magnetic forces provide a potentially power full means in designing dynamic experiments with active control of the loading conditions. This article deals with the development of computational models to simulate the thermo-mechanical response of electro-magnetically loaded metallic structures. The model assumes linear electromagnetic constitutive equations and time-independent electric induction to estimate the Joule heating and the Lorentz forces. The latter are then taken into account when evaluating stress equilibrium. A thermo-visco-plastic model with Johnson-Cook type of temperature and strain rate dependence and combined Swift-Voce hardening is used to evaluate the material's thermo-mechanical response. As a first application, the model is used to analyse the effect of electro-magnetic loading on the ductility of advanced high strength steels.

  3. Electro magnetic compatibility of cabling and wiring in buildings and installations

    NARCIS (Netherlands)

    Steenstra, H.T.

    2008-01-01

    The thesis deals with the behaviour, with respect to EMC (Electro Magnetic Compatibility), of cabling and wiring in buildings and installations. Measurement and calculation methods are developed and applied to cabling in a large scale installation as well as to individual cables. Besides, the locati

  4. Mass density of the Earth from a Gravito-Electro-Magnetic 5D vacuum

    CERN Document Server

    Musmarra, Juan Ignacio; Bellini, Mauricio

    2016-01-01

    We calculate the mass density of the Earth using a Gravito-Electro-Magnetic theory on an extended 5D Schwarzschild-de Sitter metric, in which we define the vacuum. Our results are in very good agreement with that of the Dziewonski-Anderson model.

  5. A better solar module performance obtained by employing an infrared water filter

    Energy Technology Data Exchange (ETDEWEB)

    Custodio, E.; Acosta, L. [Universidad Juarez Autonoma de Tabasco, Cunduacan-Jalpa, 86680, Tabasco (Mexico); Sebastian, P.J.; Campos, J. [CIE-UNAM, 62580 Temixco, Photovoltaic Systems Group, Solar Energy Laboratory, Privada Xochicalco S/N, Morelos (Mexico)

    2001-12-31

    In this work the authors report the results obtained from the characterization of a S{sub i} photovoltaic module, which was protected with an infrared filter (water filter). The photovoltaic parameters such as short circuit current (I{sub sc}), open circuit voltage (V{sub oc}), maximum current (I{sub m}), maximum voltage (V{sub m}), fill factor, efficiency ({eta}) and maximum power of the module were determined and compared with and without an infrared filter. A noticeable improvement in the photovoltaic parameters of the module was observed when a water filter was employed.

  6. Increasing energy relaxation time of superconducting qubits with nonmagnetic infrared filter and shield

    Science.gov (United States)

    Yuhao, Liu; Mengmeng, Li; Dong, Lan; Guangming, Xue; Xinsheng, Tan; Haifeng, Yu; Yang, Yu

    2016-05-01

    One of the primary origins of the energy relaxation in superconducting qubits is the quasiparticle loss. The quasiparticles can be excited remarkably by infrared radiation. In order to minimize the density of quasiparticle and increase the qubit relaxation time, we design and fabricate the infrared filter and shield for superconducting qubits. In comparison with previous filters and shields, a nonmagnetic dielectric is used as the infrared absorbing material, greatly suppressing the background magnetic fluctuations. The filters can be made to impedance-match with other microwave devices. Using the as-fabricated infrared filter and shield, we increased the relaxation time of a transmon qubit from 519 ns to 1125 ns. Project supported by the National Natural Science Foundation of China (Grant Nos. 91321310, 11274156, 11474152, 11474153, 61521001, and 11504165) and the State Key Program for Basic Research of China (Grant Nos. 2011CB922104 and 2011CBA00205).

  7. The Mauna Kea Observatories Near-Infrared Filter Set. III. Isophotal Wavelengths and Absolute Calibration

    CERN Document Server

    Tokunaga, A T

    2005-01-01

    The isophotal wavelengths, flux densities, and AB magnitudes for Vega (alpha Lyr) are presented for the Mauna Kea Observatories near-infrared filter set. We show that the near-infrared absolute calibration for Vega determined by Cohen et al. and Megessier are consistent within the uncertainties, so that either absolute calibration may be used.

  8. Interference filters as an enhancement tool for infrared thermography in humidity studies of building elements

    Science.gov (United States)

    Gayo, E.; de Frutos, J.

    1997-06-01

    In the present work, the utility of infrared thermography applied to the study of moisture in builiding materials or in buildings (including those cases in which the water content is very high) is shown. Moreover, an increase in the information content of the thermal image by the use of suitable interference filters is demonstrated. The use of such filters allows us to determine the kind of hydric process. In the present work, different examples are given illustrating the use of infrared thermography (with and without interference filters) when moisture movement is studied.

  9. Large-area Reflective Infrared Filters for Millimeter/sub-mm Telescopes

    CERN Document Server

    Ahmed, Z; Thompson, K L; Kuo, C L; Brooks, G; Pothoven, T

    2014-01-01

    Ground-based millimeter and sub-millimeter telescopes are attempting to image the sky with ever-larger cryogenically-cooled bolometer arrays, but face challenges in mitigating the infrared loading accompanying large apertures. Absorptive infrared filters supported by mechanical coolers scale insufficiently with aperture size. Reflective metal-mesh filters placed behind the telescope window provide a scalable solution in principle, but have been limited by photolithography constraints to diameters under 300 mm. We present laser etching as an alternate technique to photolithography for fabrication of large-area reflective filters, and show results from lab tests of 500 mm-diameter filters. Filters with up to 700 mm diameter can be fabricated using laser etching with existing capability.

  10. Replacement of filters for respirable quartz measurement in coal mine dust by infrared spectroscopy.

    Science.gov (United States)

    Farcas, Daniel; Lee, Taekhee; Chisholm, William P; Soo, Jhy-Charm; Harper, Martin

    2016-01-01

    The objective of this article is to compare and characterize nylon, polypropylene (PP), and polyvinyl chloride (PVC) membrane filters that might be used to replace the vinyl/acrylic co-polymer (DM-450) filter currently used in the Mine Safety and Health Administration (MSHA) P-7 method (Quartz Analytical Method) and the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods 7603 method (QUARTZ in coal mine dust, by IR re-deposition). This effort is necessary because the DM-450 filters are no longer commercially available. There is an impending shortage of DM-450 filters. For example, the MSHA Pittsburgh laboratory alone analyzes annually approximately 15,000 samples according to the MSHA P-7 method that requires DM-450 filters. Membrane filters suitable for on-filter analysis should have high infrared (IR) transmittance in the spectral region 600-1000 cm(-1). Nylon (47 mm, 0.45 µm pore size), PP (47 mm, 0.45 µm pore size), and PVC (47 mm, 5 µm pore size) filters meet this specification. Limits of detection and limits of quantification were determined from Fourier transform infrared spectroscopy (FTIR) measurements of blank filters. The average measured quartz mass and coefficient of variation were determined from test filters spiked with respirable α-quartz following MSHA P-7 and NIOSH 7603 methods. Quartz was also quantified in samples of respirable coal dust on each test filter type using the MSHA and NIOSH analysis methods. The results indicate that PP and PVC filters may replace the DM-450 filters for quartz measurement in coal dust by FTIR. PVC filters of 5 µm pore size seemed to be suitable replacement although their ability to retain small particulates should be checked by further experiment.

  11. Fabrication of short-wavelength infrared dual-band-pass filter based on combination of Fabry-Perot filters.

    Science.gov (United States)

    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%.

  12. Compact Micromachined Infrared Bandpass Filters for Planetary Spectroscopy

    Science.gov (United States)

    Merrell, Willie C., II; Aslam, Shahid; Brown, Ari D.; Chervenak, James A.; Huang, Wei-Chung; Quijada, Manuel; Wollack, Edward

    2011-01-01

    The future needs of space based observational planetary and astronomy missions include low mass and small volume radiometric instruments that can operate in high radiation and low temperature environments. Here we focus on a central spectroscopic component, the bandpass filter. We model the bandpass response of the filters to target the wavelength of the resonance peaks at 20, 40, and 60 micrometers and report good agreement between the modeled and measured response. We present a technique of using common micromachining processes for semiconductor fabrication to make compact, free standing resonant metal mesh filter arrays with silicon support frames. The process can accommodate multiple detector array architectures and the silicon frame provides lightweight mechanical support with low form factor. We also present a conceptual hybridization of the filters with a detector array.

  13. Piecewise Filter of Infrared Image Based on Moment Theory

    Institute of Scientific and Technical Information of China (English)

    GAO Yang; LI Yan-jun; ZHANG Ke

    2007-01-01

    The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge. To solve this problem, a piecewise moment filter (PMF) is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge.At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.

  14. Infrared moving point target detection based on spatial-temporal local contrast filter

    Science.gov (United States)

    Deng, Lizhen; Zhu, Hu; Tao, Chao; Wei, Yantao

    2016-05-01

    Infrared moving point target detection is a challenging task. In this paper, we define a novel spatial local contrast (SLC) and a novel temporal local contrast (TLC) to enhance the target's contrast. Based on the defined spatial local contrast and temporal local contrast, we propose a simple but powerful spatial-temporal local contrast filter (STLCF) to detect moving point target from infrared image sequences. In order to verify the performance of spatial-temporal local contrast filter on detecting moving point target, different detection methods are used to detect the target from several infrared image sequences for comparison. The experimental results show that the proposed spatial-temporal local contrast filter has great superiority in moving point target detection.

  15. Characterization of deep geothermal energy resources using Electro-Magnetic methods, Belgium

    Science.gov (United States)

    Loveless, Sian; Harcout-Menou, Virginie; De Ridder, Fjo; Claessens, Bert; Laenen, Ben

    2014-05-01

    Sedimentary basins in Northwest Europe have significant potential for low to medium enthalpy, deep geothermal energy resources. These resources are currently assessed using standard exploration techniques (seismic investigations followed by drilling of a borehole). This has enabled identification of geothermal resources but such techniques are extremely costly. The high cost of exploration remains one of the main barriers to geothermal project development due to the lack of capital in the geothermal industry. We will test the possibility of using the Electro-Magnetic (EM) methods to aid identification of geothermal resources in conjunction with more traditional exploration methods. An EM campaign could cost a third of a seismic campaign and is also often a passive technology, resulting in smaller environmental impacts than seismic surveys or drilling. EM methods image changes in the resistivity of the earth's sub-surface using natural or induced frequency dependant variations of electric and magnetic fields. Changes in resistivity can be interpreted as representing different subsurface properties including changes in rock type, chemistry, temperature and/or hydraulic transmissivity. While EM techniques have proven to be useful in geothermal exploration in high enthalpy areas in the last 2-3 years only a handful of studies assess their applicability in low enthalpy sedimentary basins. Challenges include identifying which sub-surface features cause changes in electrical resistivity as low enthalpy reservoirs are unlikely to exhibit the hydrothermally altered clay layer above the geothermal aquifer that is typical for high enthalpy reservoirs. Yet a principal challenge is likely to be the high levels of industrialisation in the areas of interest. Infrastructure such as train tracks and power cables can create a high level of background noise that can obfuscate the relevant signal. We present our plans for an EM campaign in the Flemish region of Belgium. Field

  16. Transmission enhancement through square coaxial apertures arrays in metallic film: when leaky modes filter infrared light

    CERN Document Server

    Vial, Benjamin; Dallaporta, Hervé; Commandré, Mireille; Demésy, Guillaume; Nicolet, André; Zolla, Frédéric; Tisserand, Stéphane; Roux, Laurent

    2014-01-01

    We consider arrays of square coaxial apertures in a gold layer and study their diffractive behavior in the far infrared region. These structures exhibit a resonant transmission enhancement that is used to design tunable bandpass filters. We provide a study of their spectral features and show by a modal analysis that the resonance peak is due to the excitation of leaky modes of the open photonic structure. Fourier transform infrared (FTIR) spectrophotometry transmission measurements of samples deposited on Si substrate show good agreement with numerical results and demonstrate angular tolerance up to 30 degrees of the fabricated filters.

  17. Locally adaptive regression filter-based infrared focal plane array non-uniformity correction

    Science.gov (United States)

    Li, Jia; Qin, Hanlin; Yan, Xiang; Huang, He; Zhao, Yingjuan; Zhou, Huixin

    2015-10-01

    Due to the limitations of the manufacturing technology, the response rates to the same infrared radiation intensity in each infrared detector unit are not identical. As a result, the non-uniformity of infrared focal plane array, also known as fixed pattern noise (FPN), is generated. To solve this problem, correcting the non-uniformity in infrared image is a promising approach, and many non-uniformity correction (NUC) methods have been proposed. However, they have some defects such as slow convergence, ghosting and scene degradation. To overcome these defects, a novel non-uniformity correction method based on locally adaptive regression filter is proposed. First, locally adaptive regression method is used to separate the infrared image into base layer containing main scene information and the detail layer containing detailed scene with FPN. Then, the detail layer sequence is filtered by non-linear temporal filter to obtain the non-uniformity. Finally, the high quality infrared image is obtained by subtracting non-uniformity component from original image. The experimental results show that the proposed method can significantly eliminate the ghosting and the scene degradation. The results of correction are superior to the THPF-NUC and NN-NUC in the aspects of subjective visual and objective evaluation index.

  18. Infrared dim target tracking based on guide filter and Bayes classification

    Science.gov (United States)

    Qian, Kun; Zhou, Hui-xin; Qin, Han-lin; Song, Shang-zhen; Zhao, Dong; Wang, Bing-jian

    2016-10-01

    An infrared dim and small tracking is proposed based on an explicit image filter - guided filter. The guided filter utilizes the structure in the guidance image and performs as an edge-preserving smoothing operator. The superior performance depending on the guidance image is critical advantage for target tracking. First, the guided filter can help to preserve the detail of the valuable templates and make the inaccurate ones blurry so that the tracker can distinguish the target from numerous bad templates easily. Besides, the filter can recover the content of the small target being influenced according to the guidance image, helping to alleviate the drifting problem effectively. Finally, the candidate samples are utilized to train an effective Bayes classifier to generate a robust tracker, which is easy to be implemented. Experimental results demonstrate that the presented method can track the target effectively, compared with several classical methods. Experimental results show that the proposed algorithm outperforms relative trackers in the accuracy and the robustness.

  19. Infrared fiber coupled acousto-optic tunable filter spectrometer

    Science.gov (United States)

    Levin, K. H.; Kindler, E.; Ko, T.; Lee, F.; Tran, D. C.; Tapphorn, R. M.

    A spectrometer design is introduced which combines an acoustooptic tunable filter (AOTF) and IR-transmitting flouride-glass fibers. The AOTF crystal is fabricated from TeO2 and permits random access to any wavelength in less than 50 microseconds, and the resulting spectrometer is tested for the remote analysis of gases and hydrocarbons. The AOTF spectrometer, when operated with a high-speed frequency synthesizer and optimized algorithms, permits accurate high-speed spectroscopy in the mid-IR spectral region.

  20. A test setup for the characterization of far-infrared filters under cryogenic conditions

    Science.gov (United States)

    Birkmann, Stephan M.; Grözinger, Ulrich; Stegmaier, Jutta; Krause, Oliver; Pitz, Eckhard; Lemke, Dietrich

    2006-06-01

    The characterization and calibration of far-infrared (FIR) detectors is a delicate task that requires good knowledge of the incident flux and its spectral composition. In many test setups the FIR flux to the detectors is provided by means of an external or internal black body and a set of cold attenuation, band pass, and blocking filters. For scientific instruments (e.g. PACS aboard ESA's Herschel satellite) band pass and blocking filters are used to achieve the desired spectral throughput either as order sorting filters in spectrometers or for selecting a wavelength range in imaging cameras. In all cases a detailed knowledge of the spectral transmittance of the used filters is mandatory for an accurate calibration of the system. We have build a test platform that allows to measure the transmission of cold (T ~ 4K) filters in the far-infrared. The setup uses a dual grating monochromator with excellent spectral purity and a resolution up to 800, which is operated under a dry nitrogen atmosphere to eliminate water vapor absorption bands. An Si-bolometer is used as detector and is read out by a cryogenic low noise trans-impedance amplifier circuit with common mode rejection and a warm electronics using a lock-in amplifier and a 22 bit analog-to-digital converter. A cryogenic filter slider in the setup allows for differential measurements between filters and the use of cold order sorting filters. We present initial results for FIR cut-on and attenuation filters, demonstrating that our setup is suited to measure transmissions as low as 10 -4 over the covered wavelength range.

  1. Changes in Ultrastructure and Sensory Characteristics on Electro-magnetic and Air Blast Freezing of Beef during Frozen Storage.

    Science.gov (United States)

    Choi, Yun-Sang; Ku, Su-Kyung; Jeong, Ji-Yun; Jeon, Ki-Hong; Kim, Young-Boong

    2015-01-01

    The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (pfrozen storage. The thawing loss of beef stored by the electro-magnetic resonance freezing was significantly lower than the air blast freezing during frozen storage (p<0.05), and it showed that the thawing loss of the round was higher than the loin. Water holding capacity decreased as the storage period became longer while the electro-magnetic resonance freezing was higher than the air blast on 8 month (p<0.05). As a result of sensory evaluation, the beef stored by the electro-magnetic resonance freezing did not show the difference until 4 months, and it showed higher acceptability in comparison with the beef stored by the air blast freezing. Thus, it is considered that the freezing method has an effect on the change in the ultrastructure and quality characteristics of the beef.

  2. Design and assembly of the CsI(T1) crystal module of the BESⅢ electro-magnetic calorimeter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The CsI(T1) crystal modules of the Beijing Spectrometer Ⅲ (BESⅢ) electro-magnetic calorimeter (EMC) were designed and assembled through Monte Carlo simulation and experiments. After the assembly was finished, the performance of each crystal module was tested by cosmic rays. All crystal modules were found to work well before the installation of EMC.

  3. An optimal algorithm based on extended kalman filter and the data fusion for infrared touch overlay

    Science.gov (United States)

    Zhou, AiGuo; Cheng, ShuYi; Pan, Qiang Biao; Sun, Dong Yu

    2016-01-01

    Current infrared touch overlay has problems on the touch point recognition which bring some burrs on the touch trajectory. This paper uses the target tracking algorithm to improve the recognition and smoothness of infrared touch overlay. In order to deal with the nonlinear state estimate problem for touch point tracking, we use the extended Kalman filter in the target tracking algorithm. And we also use the data fusion algorithm to match the estimate value with the original target trajectory. The experimental results of the infrared touch overlay demonstrate that the proposed target tracking approach can improve the touch point recognition of the infrared touch overlay and achieve much smoother tracking trajectory than the existing tracking approach.

  4. Characterization of Mid-Infrared Single Mode Fibers as Modal Filters

    Science.gov (United States)

    Ksendzov, A.; Lay, O.; Martin, S.; Sanghera, J. S.; Busse, L. E.; Kim, W. H.; Pureza, P. C.; Nguyen, V. Q.; Aggarwal, I. D.

    2007-01-01

    We present a technique for measuring the modal filtering ability of single mode fibers. The ideal modal filter rejects all input field components that have no overlap with the fundamental mode of the filter and does not attenuate the fundamental mode. We define the quality of a nonideal modal filter Q(sub f) as the ratio of transmittance for the fundamental mode to the transmittance for an input field that has no overlap with the fundamental mode. We demonstrate the technique on a 20 cm long mid-infrared fiber that was produced by the U.S. Naval Research Laboratory. The filter quality Q(sub f) for this fiber at 10.5 micron wavelength is 1000 +/- 300. The absorption and scattering losses in the fundamental mode are approximately 8 dB/m. The total transmittance for the fundamental mode, including Fresnel reflections, is 0.428 +/- 0.002. The application of interest is the search for extrasolar Earthlike planets using nulling interferometry. It requires high rejection ratios to suppress the light of a bright star, so that the faint planet becomes visible. The use of modal filters increases the rejection ratio (or, equivalently, relaxes requirements on the wavefront quality) by reducing the sensitivity to small wavefront errors. We show theoretically that, exclusive of coupling losses, the use of a modal filter leads to the improvement of the rejection ratio in a two-beam interferometer by a factor of Q(sub f).

  5. Zero Power Levitation Control of Hybrid Electro-Magnetic Levitation System by Load Observer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youn Hyun; Lee, Ju [Hanyang University, Seoul (Korea)

    2001-06-01

    This paper introduces the scheme that improve the control performance of electromagnetic levitation system with zero power controller. Magnetic levitation is used widely, but the electromagnetic force has nonlinear characteristics because it is proportioned to a square of the magnetic flux density and it is in inverse proportion to a square of the air gap. So, it is complicate and difficult to control the electromagnetic force. Besides, it is more difficult to control if the equivalent gap is unknown in case of zero power control. Therefore, this paper proposed the hybrid electro-magnetic levitation control method in which the variable load is estimated by using a load observer and its system is controlled at a new zero power equilibrium air gap position. Also it is confirmed that the proposed control method improve the control performance through simulation and experiment. (author). 10 refs., 17 figs., 1 tab.

  6. Embedded Spherical Localization for Micro Underwater Vehicles Based on Attenuation of Electro-Magnetic Carrier Signals

    Directory of Open Access Journals (Sweden)

    Daniel-André Duecker

    2017-04-01

    Full Text Available Self-localization is one of the most challenging problems for deploying micro autonomous underwater vehicles ( μ AUV in confined underwater environments. This paper extends a recently-developed self-localization method that is based on the attenuation of electro-magnetic waves, to the μ AUV domain. We demonstrate a compact, low-cost architecture that is able to perform all signal processing steps present in the original method. The system is passive with one-way signal transmission and scales to possibly large μ AUV fleets. It is based on the spherical localization concept. We present results from static and dynamic position estimation experiments and discuss the tradeoffs of the system.

  7. Invariance properties of the Dirac equation with external electro-magnetic field

    Indian Academy of Sciences (India)

    N D Sen Gupta

    2003-01-01

    In this paper, we attempt to obtain the nature of the external field such that the Dirac equation with external electro-magnetic field is invariant. The Poincar´e group, which is the maximal symmetry group for field free case, is constrained by the presence of the external field. Introducing infinitesimal transformation of x andψ, we apply Lie’s extended group method to obtain the class of external field which admit of the invariance of the equation. It is important to note that the constraints for the existence of invariance are explicity on the electric and magnetic field, though only potentials explicity appears in the equation.

  8. Equivalent-nanocircuit-theory-based design to infrared broad band-stop filters.

    Science.gov (United States)

    Zhang, Qing; Bai, Lihua; Bai, Zhengyuan; Hu, Pidong; Liu, Chengpu

    2015-04-06

    We theoretically introduced a design paradigm and tool by extending the circuit functionalities from radio frequency to near infrared domain, and a broad band-stop filter, is successfully demonstrated by cascading triple layers of nano-square arrays. The feasibility is confirmed by its consistency with the rigorous FDTD calculation. Moreover, such a third-order Butterworth filter is not only insensitive to the incident angle and but also to input light's polarization. The new paradigm forms a theoretical foundation for designing optical devices and also enriches the classic circuit operations at the optical frequency region.

  9. Filtering characteristics of a graphene ribbon with a rectangle ring in infrared region

    Directory of Open Access Journals (Sweden)

    Yueke Wang

    2016-11-01

    Full Text Available We propose a structure of a graphene ribbon with a rectangle ring, which is deposited on SiO2 substrate. Our simulation results, conducted by finite element method, show that the transmission dips originate from the ring resonance of the fundamental edge graphene plasmons mode. By choosing specific parameters, the transmission dips of 6th and 4th order ring resonances can split into two, respectively, due to corner effect. Thanks to tunable permittivity of graphene by gate voltages, active control of filtering window is achieved. It is believed that our findings provide a smart way to design a tunable multiple window filter at infrared region.

  10. Sono-electro-magnetic therapy for treating chronic pelvic pain syndrome in men: A randomized, placebo-controlled, double-blind trial

    OpenAIRE

    2014-01-01

    OBJECTIVE: To assess the efficacy and safety of sono-electro-magnetic therapy compared to placebo in men with refractory CPPS. PATIENTS AND METHODS: In a randomized, placebo-controlled, double-blind single center trial, we assessed the effect of sono-electro-magnetic therapy in men with treatment refractory CPPS. Sixty male patients were randomly assigned to treatment with either sono-electro-magnetic (n = 30) or placebo therapy (n = 30) for 12 weeks. The primary outcome was a change in the N...

  11. Cooled optical filters for Q-band infrared astronomy (15-40 μm)

    Science.gov (United States)

    Hawkins, Gary J.; Sherwood, Richard E.; Djotni, Karim; Threadgold, Timothy M.

    2016-07-01

    With a growing interest in mid- and far-infrared astronomy using cooled imaging and spectrometer instruments in highaltitude observatories and spaceflight telescopes, it is becoming increasingly important to characterise and assess the spectral performance of cooled multilayer filters across the Q-band atmospheric window. This region contains spectral features emitted by many astrophysical phenomena and objects fundamental to circumstellar and planetary formation theories. However extending interference filtering to isolate radiation at progressively longer wavelengths and improve photometric accuracy is an area of ongoing and challenging thin-film research. We have successfully fabricated cooled bandpass and edge filters with high durability for operation across the 15-30 μm Q-band region. In this paper we describe the rationale for selection of optical materials and properties of fabricated thin-film coatings for this region, together with FTIR spectral measurements and assessment of environmental durability.

  12. Design, fabrication and characterization of resonant metamaterial filters for infrared multispectral imaging

    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.

  13. Novel Spatiotemporal Filter for Dim Point Targets Detection in Infrared Image Sequences

    Directory of Open Access Journals (Sweden)

    Zhaohui Li

    2015-01-01

    Full Text Available Dim point target detection is of great importance in both civil and military fields. In this paper a novel spatiotemporal filter is proposed to incorporate both the spatial and temporal features of moving dim point targets. Since targets are expected to be detected as far as possible, in this situation, they have no texture features in spatial dimensions, appearing like isolated points. Based on the attributes, potential targets are extracted by searching the local maximum point in a sliding window. And the potential targets are then correlated based on target moving patterns. After combining local maximum points and target moving patterns, structure background in infrared scene is removed. Next, the temporal profiles of infrared sense are reviewed and examined. By a new max-median filter performing on temporal profiles, the intensity of target pulse signal is extracted. Finally, each temporal profile is divided into several pieces to estimate the variance of the temporal profiles, which leads to a new detection metric. The proposed approach is tested via several infrared image sequences. The results show that our proposed method can significantly reduce the complex background in aerial infrared image sequence and have a good detection performance.

  14. Transient Fluid Flow during Steady Continuous Casting of Steel Slabs: Part II. Effect of Double-Ruler Electro-Magnetic Braking

    National Research Council Canada - National Science Library

    Cho, Seong-Mook; Kim, Seon-Hyo; Thomas, Brian G

    2014-01-01

    ... steady steel slab casting. In Part II of this two-part article, the effect of applying a static magnetic field on stabilizing the transient flow is investigated by modeling a double-ruler Electro-Magnetic Braking (EMBr...

  15. CORTIZOL LEVEL AND ADRENAL GLAND MORPHOLOGY UNDER INFLUENCE OF LOW-INTENSITY ELECTRO-MAGNETIC WAVES AND UNDER STRESS

    Directory of Open Access Journals (Sweden)

    L.I. Naumova

    2008-03-01

    Full Text Available Low-intensify electro-magnetic waves (EMW influence were studied at experiment. Certain EMI frequency regimes (they are transparent for the water and water-binding substances, and they are known as trans-resonance can intensify the metabolic rate. In turn, certain EMW frequency regimes (they are not transparent for the water and the water-containing tissues, and they are called as non-resonance can disturb the native electro-magnetic status of the cells and can lead to morphological changes in organs. Morphological changes in adrenal glands and cortizol level of 60 White Vistar rats (males in serum under transparent EMW frequency regimes and non-transparent ones were examined. Transparent and non-transparent frequency regimes impact the various changes in adrenals. Cortizol level corresponds to morphologic conclusion. Stress modified EMW-effects in both variants - under resonance and non-resonance EMW frequency regimes in adrenal morphology and cortizol level.

  16. Infrared dim-small target tracking via singular value decomposition and improved Kernelized correlation filter

    Science.gov (United States)

    Qian, Kun; Zhou, Huixin; Rong, Shenghui; Wang, Bingjian; Cheng, Kuanhong

    2017-05-01

    Infrared small target tracking plays an important role in applications including military reconnaissance, early warning and terminal guidance. In this paper, an effective algorithm based on the Singular Value Decomposition (SVD) and the improved Kernelized Correlation Filter (KCF) is presented for infrared small target tracking. Firstly, the super performance of the SVD-based algorithm is that it takes advantage of the target's global information and obtains a background estimation of an infrared image. A dim target is enhanced by subtracting the corresponding estimated background with update from the original image. Secondly, the KCF algorithm is combined with Gaussian Curvature Filter (GCF) to eliminate the excursion problem. The GCF technology is adopted to preserve the edge and eliminate the noise of the base sample in the KCF algorithm, helping to calculate the classifier parameter for a small target. At last, the target position is estimated with a response map, which is obtained via the kernelized classifier. Experimental results demonstrate that the presented algorithm performs favorably in terms of efficiency and accuracy, compared with several state-of-the-art algorithms.

  17. Long-period suspended silicon Bragg grating filter for hybrid near- and mid-infrared operation

    CERN Document Server

    Alonso-Ramos, Carlos; Benedikovic, Daniel; Vakarin, Vladyslav; Duran-Valdeiglesias, Elena; Perez-Galacho, Diego; Cassan, Eric; Marris-Morini, Delphine; Cheben, Pavel; Vivien, Laurent

    2016-01-01

    The large transparency window of silicon, covering the 1.1 um 8 um wavelength range, makes it a promising platform for the implementation of photothermal-based absorption spectrometers. These devices indirectly sense absorption in the mid-infrared (MIR) by using near-infrared (NIR) wavelengths, thereby enabling the realization of MIR absorption spectrometers without the need for MIR photodetectors. Nevertheless, due to their comparatively large index contrast and cross-sections, MIR Si strip waveguides are multi-mode at NIR wavelengths, hindering device implementation. Here we present, for the first time, an integrated Bragg grating waveguide filter for hybrid near- and mid-infrared operation. Specifically, the filter is implemented in a single-etch suspended silicon corrugated waveguide with an effectively single-mode operation in NIR region for a waveguide cross-section as large as 0.5 um x 1.1 um. At the same time, the waveguide supports single-mode propagation in MIR region. We demonstrate a long-period w...

  18. Active Vibration Control of Beam Using Electro-magnetic Constrained Layer Damping

    Institute of Scientific and Technical Information of China (English)

    Niu Hongpan; Zhang Yahong; Zhang Xinong; Xie Shilin

    2008-01-01

    This paper investigates vibration control of beam through electro-magnetic constrained layer damping (EMCLD) which consists of electromagnet layer, permanent magnet layer and viscoelastic damping layer. When the coil of the electromagnet is electrified with proper control strategy, the electromagnet can exert magnetic force opposite to the direction of structural deformation so that the struc- tural vibration is attenuated. A mathematical model is developed based on the equivalent current method to calculate the electromagnetic control force produced by EMCLD. The governing equations of the system are obtained using Hamilton's Principle and then reduced with the assumed-mode method. A simulation on vibration control of a cantilever beam is conducted under the velocity proportional feedback to demonstrate the energy dissipation capability of EMCLD, and the beam system with the same parameter is experimented. The results of experiment and simulation are compared and the results show that the EMCLD is an effective means for suppressing modal vibration. The results also indicate that the beam system has better control performance for larger control current. The EMCLD method presented in this paper provides an applicable and efficient tool for the vibration control of structures.

  19. Flow pattern and lift evolution of hydrofoil with control of electro-magnetic forces

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The initial responses and evolutions of the flow pattern and lift coefficient of a hydrofoil under the action of electro-magnetic (Lorentz) force have been studied experimentally and numerically, and trace particle methods are employed for them. With the introduction of BVF (boundary vortex flux), the quantitative relation among Lorentz forces, BVF and lifts is deduced. The influences of flow patterns on the hydrofoil lift coefficient have been discussed based on the BVF distribution, and the flow control mechanism of Lorentz force for a hydrofoil has been elucidated. Our results show that the flow pattern and lift of the hydrofoil vary periodically without any force. However, with the action of streamwise Lorentz forces, the separation point on the hydrofoil surface moves backward with a certain velocity, which makes the flow field steady finally. The streamwise Lorentz force raises the foil lift due to the increase of BVF intensity. On the other hand, Lorentz force also increases the hydrofoil surface pressure, which makes the lift decrease. However, the factor leading to the lift enhancement is determinant, therefore, the Lorentz force on the suction side can increase the lift, and the stronger the Lorentz force, the larger the lift enhancement. Our results also show that the localized Lorentz force can also both suppress the flow separation and increase the hydrofoil lift coefficient, furthermore, the Lorentz force located on the tail acts better than that located on the front.

  20. Strategies, Protections and Mitigations for Electric Grid Affets from Electro-Magnetic Pulse

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Rita Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States); Frickey, Steven Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    The mission of DOE’s Office of Electricity Delivery and Energy Reliability (OE) is to lead national efforts to modernize the electricity delivery system, enhance the security and reliability of America’s energy infrastructure and facilitate recovery from disruptions to the energy supply. One of the threats OE is concerned about is a high-altitude electro-magnetic pulse (HEMP) from a nuclear explosion and eletro-magnetic pulse (EMP) or E1 pulse can be generated by EMP weapons. DOE-OE provides federal leadership and technical guidance in addressing electric grid issues. The Idaho National Laboratory (INL) was chosen to conduct the EMP study for DOE-OE due to its capabilities and experience in setting up EMP experiments on the electric grid and conducting vulnerability assessments and developing innovative technology to increase infrastructure resiliency. This report identifies known impacts to EMP threats, known mitigations and effectiveness of mitigations, potential cost of mitigation, areas for government and private partnerships in protecting the electric grid to EMP, and identifying gaps in our knowledge and protection strategies.

  1. Concrete filled steel pipe inspection using electro magnetic acoustic transducer (EMAT)

    Science.gov (United States)

    Na, Won-Bae; Kundu, Tribikram; Ryu, Yeon-Sun; Kim, Jeong-Tae

    2005-05-01

    Concrete-filled steel pipes are usually exposed in hostile environments such as seawater and deicing materials. The outside corrosion of the steel pipe can reduce the wall thickness and the corrosion-induced delamination of internal concrete can increase internal volume or pressure. In addition, the void that can possibly exist in the pipe reduces the bending resistance. To avoid structural failure due to this type of deterioration, appropriate inspection and repair techniques are to be developed. Guided wave techniques have strong potentials for this kind of inspection because of long-distance inspection capability. Among different transducer-coupling mechanism, electro-magnetic acoustic transducers (EMATs) give relatively consistent results in comparison to piezoelectric transducers since they do not need any couplant. In this study EMATs are used for transmitting and receiving cylindrical guided waves through concrete-filled steel pipes. Through time history curves and wavelet transform, it is shown that EMAT-generated cylindrical guided wave techniques have good potential for the interface inspection of concrete-filled steel pipes.

  2. Observing white dwarfs orbiting massive black holes in the gravitational wave and electro-magnetic window

    CERN Document Server

    Sesana, A; Eracleous, M; Sigurdsson, S

    2008-01-01

    We consider a potentially new class of gravitational wave sources consisting of a white dwarf coalescing into a massive black hole in the mass range ~10^4-10^5\\msun. These sources are of particular interest because the gravitational wave signal produced during the inspiral phase can be detected by the Laser Interferometer Space Antenna (LISA) and is promptly followed, in an extended portion of the black hole and white dwarf mass parameter space, by an electro-magnetic signal generated by the tidal disruption of the star, detectable with X-ray, optical and UV telescopes. This class of sources could therefore yield a considerable number of scientific payoffs, that include precise cosmography at low redshift, demographics of black holes in the mass range ~10^4-10^5\\Msun, insights into dynamical interactions and populations of white dwarfs in the cores of dwarf galaxies, as well as a new probe into the structure and equation of state of white dwarfs. By modelling the gravitational and electromagnetic radiation pr...

  3. High dynamic range infrared images detail enhancement based on local edge preserving filter

    Science.gov (United States)

    Song, Qiong; Wang, Yuehuan; Bai, Kun

    2016-07-01

    In the field of infrared (IR) image processing, displaying a high dynamic range (HDR) image on a low dynamic range display equipment with a natural visual effect, clear details on local areas and less artifacts is an important issue. In this paper, we present a new approach to display HDR IR images with contrast enhancement. First, the local edge-preserving filter (LEPF) is utilized to separate the image into a base layer and detail layer(s). After the filtering procedure, we use an adaptive Gamma transformation to adjust the gray distribution of the base layer, and stretch the detail layer based on a human visual effect principle. Then, we recombine the detail layer and base layer to obtain the enhance output. Finally, we adjust the luminance of output by applying multiple exposure fusion method. The experimental results demonstrate that our proposed method can provide a significant performance in terms of enhancing details and less artifacts than the state of the arts.

  4. [Water-filtered infrared-A (wIRA) promotes wound healing].

    Science.gov (United States)

    Winkel, R; Hoffmann, G; Hoffmann, R

    2014-11-01

    Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and low thermal load to the skin surface which promotes the healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic effects. Water-filtered infrared-A increases tissue temperature (+ 2.7 °C at a tissue depth of 2 cm), tissue oxygen partial pressure (+ 32 % at a tissue depth of 2 cm) and tissue perfusion. These three factors are decisive for a sufficient supply of tissue with energy and oxygen and consequently also for wound healing and infection defense. Water-filtered infrared-A promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain. These effects have been proven in a total of seven prospective studies (of these six randomized controlled studies) with most of the effects having an evidence level of Ia or Ib. The additional cases of complicated courses of wound healing presented in this article illustrate the proven effects of wIRA. Not only in the 6 presented cases wIRA turned the complicated courses of wound healing for the better and facilitated the healing of the wounds after varying total times of irradiation (in the 6 cases 51-550 h) and after variable times of wound care and mostly after transplantation of split skin grafts. In complicated courses of wound healing wIRA does not replace consultation and, when indicated, treatment by an experienced plastic surgeon and by a surgeon specialized in septic surgery. With these limitations wIRA can be recommended as a valuable complement for the treatment of acute as well as of chronic wounds.

  5. [Characteristic wavelength variable optimization of near-infrared spectroscopy based on Kalman filtering].

    Science.gov (United States)

    Wang, Li-Qi; Ge, Hui-Fang; Li, Gui-Bin; Yu, Dian-Yu; Hu, Li-Zhi; Jiang, Lian-Zhou

    2014-04-01

    Combining classical Kalman filter with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman filtering method, is presented. The principle of Kalman filter for selecting optimal wavelength variable was analyzed. The wavelength selection algorithm was designed and applied to NIR detection of soybean oil acid value. First, the PLS (partial leastsquares) models were established by using different absorption bands of oil. The 4 472-5 000 cm(-1) characteristic band of oil acid value, including 132 wavelengths, was selected preliminarily. Then the Kalman filter was used to select characteristic wavelengths further. The PLS calibration model was established using selected 22 characteristic wavelength variables, the determination coefficient R2 of prediction set and RMSEP (root mean squared error of prediction) are 0.970 8 and 0.125 4 respectively, equivalent to that of 132 wavelengths, however, the number of wavelength variables was reduced to 16.67%. This algorithm is deterministic iteration, without complex parameters setting and randomicity of variable selection, and its physical significance was well defined. The modeling using a few selected characteristic wavelength variables which affected modeling effect heavily, instead of total spectrum, can make the complexity of model decreased, meanwhile the robustness of model improved. The research offered important reference for developing special oil near infrared spectroscopy analysis instruments on next step.

  6. A Novel Approach to Fast Image Filtering Algorithm of Infrared Images based on Intro Sort Algorithm

    CERN Document Server

    Gupta, Kapil Kumar; Niranjan, Jitendra Kumar

    2012-01-01

    In this study we investigate the fast image filtering algorithm based on Intro sort algorithm and fast noise reduction of infrared images. Main feature of the proposed approach is that no prior knowledge of noise required. It is developed based on Stefan- Boltzmann law and the Fourier law. We also investigate the fast noise reduction approach that has advantage of less computation load. In addition, it can retain edges, details, text information even if the size of the window increases. Intro sort algorithm begins with Quick sort and switches to heap sort when the recursion depth exceeds a level based on the number of elements being sorted. This approach has the advantage of fast noise reduction by reducing the comparison time. It also significantly speed up the noise reduction process and can apply to real-time image processing. This approach will extend the Infrared images applications for medicine and video conferencing.

  7. Optical readout uncooled infrared imaging detector using knife-edge filter operation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Q; MIAO Z; GUO Z; DONG F; XIONG Z; WU X; CHEN D; LI C; JIAO B

    2007-01-01

    An optical readout uncooled infrared (IR) imaging detector of bimaterial cantilever array using knife-edge filter operation(KEFO) is demonstrated. The angle change of each cantilever in a focal plane array (FPA) can be simultaneously detected with a resolution of 10-5 degree. A deformation magnifying substrate-free micro-cantilever unit with multi-fold interval metallized legs is specially designed and modeled. A FPA with 160× 160 pixels is fabricated and thermal images with noise equivalent temperature difference (NETD) of 400 mK are obtained by this imaging detector.

  8. Spectral design of temperature-invariant narrow bandpass filters for the mid-infrared

    DEFF Research Database (Denmark)

    Stolberg-Rohr, Thomine Kirstine; Hawkins, Gary J.

    2015-01-01

    The ability of narrow bandpass filters to discriminatewavelengths between closely-separated gas absorption lines is crucial inmany areas of infrared spectroscopy. As improvements to the sensitivity ofinfrared detectors enables operation in uncontrolled high-temperature environments, this imposes...... demands on the explicit bandpass design to provide temperature-invariant behavior. The unique negative temperature coefficient (dn/dTfilters with exclusive immunity to shifts in wave length with temperature. This paper...... presents the results of an investigation into the interdependence between multilayer bandpass designand optical materials together with a review on invariance at elevated temperatures....

  9. Far infrared-assisted encapsulation of filter paper strips in poly(methyl methacrylate) for proteolysis.

    Science.gov (United States)

    Chen, Qiwen; Bao, Huimin; Zhang, Luyan; Chen, Gang

    2016-02-01

    Filter paper strips were enclosed between two poly(methyl methacrylate) plates to fabricate paper-packed channel microchips under pressure in the presence of far infrared irradiation. After the enclosed paper strip was oxidized by periodate, trypsin was covalently immobilized in them to fabricate microfluidic proteolysis bioreactor. The feasibility and performance of the unique bioreactor were demonstrated by digesting BSA and lysozyme. The results were comparable to those of conventional in-solution proteolysis while the digestion time was significantly reduced to ∼18 s. The suitability of the microfluidic paper-based bioreactors to complex proteins was demonstrated by digesting human serum.

  10. A robust infrared dim target detection method based on template filtering and saliency extraction

    Science.gov (United States)

    Wang, Wenguang; Li, Chenming; Shi, Jianing

    2015-11-01

    Dim target detection in infrared image with complex background and low signal-clutter ratio (SCR) is a significant and difficult task in the infrared target tracking system. A robust infrared dim target detection method based on template filtering and saliency extraction is proposed in this paper. The weighted gray map is obtained from the infrared image to highlight the target which is brighter than its neighbors and has weak correlation with its background. The target saliency map is then calculated by phase spectrum of Fourier Transform, so that the dim target detection could be converted to salient region extraction. The potential targets are finally extracted by combining the two maps. Moreover, position discrimination between targets in the two maps is used to exclude the false alarms and extract the targets. Experimental results on measured images indicate that our method is feasible, adaptable and robust in different backgrounds. The ROC (Receiver Operating Characteristic) curves obtained from the simulated images demonstrate the proposed method outperforms some existing typical methods in both detection rate and false alarm rate, for target detection with low SCR.

  11. Infrared Filter Radiometers for Thermodynamic Temperature Determination below 660 °C

    Science.gov (United States)

    Noulkow, N.; Taubert, R. D.; Meindl, P.; Hollandt, J.

    2009-02-01

    At the Physikalisch-Technische Bundesanstalt (PTB), absolutely-calibrated filter radiometers based on silicon photodiodes are routinely used for thermodynamic temperature determinations of blackbodies in the range from the zinc fixed point (FP) (419 °C) up to 3,000 °C. To extend the temperature range down to the tin FP (232 °C), we have designed two new filter radiometers based on indium gallium arsenide (InGaAs) photodiodes with center wavelengths at 1,300 nm and 1,550 nm. For the absolute calibration of the spectral irradiance responsivity of the new InGaAs filter radiometers, the spectral responsivity measurement in the near-infrared (NIR) spectral range has been significantly improved. With a newly developed tuneable laser and monochromator-based cryogenic radiometer facility, the relative standard uncertainty of the NIR spectral responsivity has been reduced from 0.17 % to about 0.03 %. By using the calibrated InGaAs filter radiometer in conjunction with the large-area double sodium heat pipe of the PTB, the first results for the difference between the thermodynamic temperature T and the ITS-90 temperature T 90 in the temperature range from the zinc FP up to the aluminum FP (660 °C) are presented. The values for T - T 90 determined with the new InGaAs filter radiometers are consistent within their relative standard uncertainty of about 30 mK at 419 °C to about 60 mK at 660 °C.

  12. Flow pattern and lift evolution of hydrofoil with control of electro-magnetic forces

    Institute of Scientific and Technical Information of China (English)

    CHEN YaoHui; FAN BaoChun; CHEN ZhiHua; LI HongZhi

    2009-01-01

    The Initial responses and evolutions of the flow pattern and lift coefficient of a hydrofoil under the ac-tion of electro-magnetic (Lorentz) force have been studied experimentally and numerically,and trace particle methods are employed for them.With the introduction of BVF (boundary vortex flux),the quantitative relation among Lorentz forces,BVF and lifts is deduced.The influences of flow patterns on the hydrofoil lift coefficient have been discussed based on the BVF distribution,and the flow control mechanism of Lorentz force for a hydrofoil has been elucidated.Our results show that the flow pattern and lift of the hydrofoil vary periodically without any force.However,with the action of streamwise Lorentz forces,the separation point on the hydrofoil surface moves backward with a certain velocity,which makes the flow field steady finally.The streamwise Lorentz force raises the foil lift due to the Increase of BVF intensity.On the other hand,Lorentz force also increases the hydrofoil surface pres-sure,which makes the lift decrease.However,the factor leading to the lift enhancement is determinant,therefore,the Lorentz force on the suction side can increase the lift,and the stronger the Lorentz force,the larger the lift enhancement.Our results also show that the localized Lorentz force can also both suppress the flow separation and increase the hydrofoil lift coefficient,furthermore,the Lorentz force located on the tail acts better than that located on the front.

  13. Combined ULF and VLF observations of seismo-electro-magnetic phenomena in Europe

    Science.gov (United States)

    Schwingenschuh, Konrad; Eichelberger, Hans; Wolbang, Daniel; Prattes, Gustav; Besser, Bruno; Boudjada, Mohammed Y.; Stangl, Günter; Magnes, Werner; Berghofer, Gerhard; Aydogar, Özer; Rozhnoi, Alexander; Solovieva, Maria; Vellante, Massimo; Villante, Umberto; Biagi, Pier F.

    2014-05-01

    A combined analysis of magnetic ultra-low-frequency (ULF) and electromagnetic very-low-frequency (VLF) fluctuations before, during and after earthquakes in south and south-east Europe is presented. The magnetic fluctuations are studied in the frame of the South European Geomagnetic Array (SEGMA) network. The fluxgate and searchcoil magnetometers, located in Italy, Bulgaria and Hungary perform measurements of fluctuations in the pico-Tesla and nano-Tesla range from milli-Hertz to 100 Hz. The properties of VLF radio links (10 kHz - 50 kHz) are studied in the frame of the European VLF/LF radio receiver network (INFREP). Single parameter studies of ULF and VLF variations in the vicinity of earthquakes in Europe have been performed in the last decade (Villante et al. 2010, Rozhnoi et al. 2009). We present the first results of a dual parameter study based on single parameter ULF and VLF observations. The proposed method provides the opportunity to decrease the number of false alerts. A dual parameter seismo-electro-magnetic reliability number is developed and compared with single parameter quality numbers. References: Rozhnoi, A., Solovieva, M., Molchanov, O., Schwingenschuh, K., Boudjada, M., Biagi, P. F., Maggipinto, T., Castellana, L., Ermini, A., and Hayakawa, M.: Anomalies in VLF radio signals prior the Abruzzo earthquake (M=6.3) on 6 April 2009, Nat. Hazards Earth Syst. Sci., 9, 1727-1732, doi:10.5194/nhess-9-1727-2009, 2009. Villante, U., De Lauretis, M., De Paulis, C., Francia, P., Piancatelli, A., Pietropaolo, E., Vellante, M., Meloni, A., Palangio, P., Schwingenschuh, K., Prattes, G., Magnes, W., and Nenovski, P.: The 6 April 2009 earthquake at L'Aquila: a preliminary analysis of magnetic field measurements, Nat. Hazards Earth Syst. Sci., 10, 203-214, doi:10.5194/nhess-10-203-2010, 2010.

  14. Classification of visible and infrared hyperspectral images based on image segmentation and edge-preserving filtering

    Science.gov (United States)

    Cui, Binge; Ma, Xiudan; Xie, Xiaoyun; Ren, Guangbo; Ma, Yi

    2017-03-01

    The classification of hyperspectral images with a few labeled samples is a major challenge which is difficult to meet unless some spatial characteristics can be exploited. In this study, we proposed a novel spectral-spatial hyperspectral image classification method that exploited spatial autocorrelation of hyperspectral images. First, image segmentation is performed on the hyperspectral image to assign each pixel to a homogeneous region. Second, the visible and infrared bands of hyperspectral image are partitioned into multiple subsets of adjacent bands, and each subset is merged into one band. Recursive edge-preserving filtering is performed on each merged band which utilizes the spectral information of neighborhood pixels. Third, the resulting spectral and spatial feature band set is classified using the SVM classifier. Finally, bilateral filtering is performed to remove "salt-and-pepper" noise in the classification result. To preserve the spatial structure of hyperspectral image, edge-preserving filtering is applied independently before and after the classification process. Experimental results on different hyperspectral images prove that the proposed spectral-spatial classification approach is robust and offers more classification accuracy than state-of-the-art methods when the number of labeled samples is small.

  15. Do the results of respirable dust samples obtained from direct-on-filter X-ray diffraction, direct-on-filter infrared and indirect infrared (KBr pellet) methods correlate?

    CSIR Research Space (South Africa)

    Pretorius, C

    2010-11-01

    Full Text Available determines how the dust is distributed on the filter (analysis area of XRD vs FTIR). Current research Acknowledgements The Mine Health and Safety Council (MHSC) of South Africa provided the funding for this research project (SIM 080601) References 1.... ?MDHS 101. Direct-on-filter analysis by infrared spectroscopy and X-ray diffraction?, February 2005, Health and Safety Laboratory: Methods for the Determination of Hazardous Substances. 2. Occupational Health and Safety Administration (OSHA), Quartz...

  16. Resonant metamaterial absorbers for infrared spectral filtering: quasimodal analysis, design, fabrication and characterization

    CERN Document Server

    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.

  17. A complex multi-notch astronomical filter to suppress the bright infrared sky.

    Science.gov (United States)

    Bland-Hawthorn, J; Ellis, S C; Leon-Saval, S G; Haynes, R; Roth, M M; Löhmannsröben, H-G; Horton, A J; Cuby, J-G; Birks, T A; Lawrence, J S; Gillingham, P; Ryder, S D; Trinh, C

    2011-12-06

    A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.

  18. A method for retrieving clouds with satellite infrared radiances using the particle filter

    Science.gov (United States)

    Xu, Dongmei; Auligné, Thomas; Descombes, Gaël; Snyder, Chris

    2016-11-01

    Ensemble-based techniques have been widely utilized in estimating uncertainties in various problems of interest in geophysical applications. A new cloud retrieval method is proposed based on the particle filter (PF) by using ensembles of cloud information in the framework of Gridpoint Statistical Interpolation (GSI) system. The PF cloud retrieval method is compared with the Multivariate Minimum Residual (MMR) method that was previously established and verified. Cloud retrieval experiments involving a variety of cloudy types are conducted with the PF and MMR methods with measurements of infrared radiances on multi-sensors onboard both geostationary and polar satellites, respectively. It is found that the retrieved cloud masks with both methods are consistent with other independent cloud products. MMR is prone to producing ambiguous small-fraction clouds, while PF detects clearer cloud signals, yielding closer heights of cloud top and cloud base to other references. More collections of small-fraction particles are able to effectively estimate the semi-transparent high clouds. It is found that radiances with high spectral resolutions contribute to quantitative cloud top and cloud base retrievals. In addition, a different way of resolving the filtering problem over each model grid is tested to better aggregate the weights with all available sensors considered, which is proven to be less constrained by the ordering of sensors. Compared to the MMR method, the PF method is overall more computationally efficient, and the cost of the model grid-based PF method scales more directly with the number of computing nodes.

  19. Cooled infrared filters and dichroics for the sea and land surface temperature radiometer.

    Science.gov (United States)

    Hawkins, Gary; Sherwood, Richard; Djotni, Karim; Coppo, Peter; Höhnemann, Holger; Belli, Fabio

    2013-04-01

    The sea and land surface temperature radiometer (SLSTR) is a nine-channel visible and infrared high-precision radiometer designed to provide climate data of global sea and land surface temperatures. The SLSTR payload is destined to fly on the Ocean and Medium-Resolution Land Mission for the ESA/EU global monitoring for environment and security (GMES) programme Sentinel-3 mission to measure the sea and land temperature and topography for near real-time environmental and atmospheric climate monitoring of the Earth. In this paper we describe the optical layout of infrared optics in the instrument, the spectral thin-film multilayer design, and the system channel throughput analysis for the combined interference filter and dichroic beam splitter coatings to discriminate wavelengths at 3.74, 10.85, 12.0 μm. The rationale for selection of thin-film materials, the deposition technique, and environmental testing, inclusive of humidity, thermal cycling, and ionizing radiation testing are also described.

  20. Water-filtered infrared a irradiation in combination with visible light inhibits acute chlamydial infection.

    Directory of Open Access Journals (Sweden)

    Hanna Marti

    Full Text Available New therapeutic strategies are needed to overcome drawbacks in treatment of infections with intracellular bacteria. Chlamydiaceae are Gram-negative bacteria implicated in acute and chronic diseases such as abortion in animals and trachoma in humans. Water-filtered infrared A (wIRA is short wavelength infrared radiation with a spectrum ranging from 780 to 1400 nm. In clinical settings, wIRA alone and in combination with visible light (VIS has proven its efficacy in acute and chronic wound healing processes. This is the first study to demonstrate that wIRA irradiation combined with VIS (wIRA/VIS diminishes recovery of infectious elementary bodies (EBs of both intra- and extracellular Chlamydia (C. in two different cell lines (Vero, HeLa regardless of the chlamydial strain (C. pecorum, C. trachomatis serovar E as shown by indirect immunofluorescence and titration by subpassage. Moreover, a single exposure to wIRA/VIS at 40 hours post infection (hpi led to a significant reduction of C. pecorum inclusion frequency in Vero cells and C. trachomatis in HeLa cells, respectively. A triple dose of irradiation (24, 36, 40 hpi during the course of C. trachomatis infection further reduced chlamydial inclusion frequency in HeLa cells without inducing the chlamydial persistence/stress response, as ascertained by electron microscopy. Irradiation of host cells (HeLa, Vero neither affected cell viability nor induced any molecular markers of cytotoxicity as investigated by Alamar blue assay and Western blot analysis. Chlamydial infection, irradiation, and the combination of both showed a similar release pattern of a subset of pro-inflammatory cytokines (MIF/GIF, Serpin E1, RANTES, IL-6, IL-8 and chemokines (IL-16, IP-10, ENA-78, MIG, MIP-1α/β from host cells. Initial investigation into the mechanism indicated possible thermal effects on Chlamydia due to irradiation. In summary, we demonstrate a non-chemical reduction of chlamydial infection using the combination

  1. Water-Filtered Infrared A Irradiation in Combination with Visible Light Inhibits Acute Chlamydial Infection

    Science.gov (United States)

    Marti, Hanna; Koschwanez, Maria; Pesch, Theresa; Blenn, Christian; Borel, Nicole

    2014-01-01

    New therapeutic strategies are needed to overcome drawbacks in treatment of infections with intracellular bacteria. Chlamydiaceae are Gram-negative bacteria implicated in acute and chronic diseases such as abortion in animals and trachoma in humans. Water-filtered infrared A (wIRA) is short wavelength infrared radiation with a spectrum ranging from 780 to 1400 nm. In clinical settings, wIRA alone and in combination with visible light (VIS) has proven its efficacy in acute and chronic wound healing processes. This is the first study to demonstrate that wIRA irradiation combined with VIS (wIRA/VIS) diminishes recovery of infectious elementary bodies (EBs) of both intra- and extracellular Chlamydia (C.) in two different cell lines (Vero, HeLa) regardless of the chlamydial strain (C. pecorum, C. trachomatis serovar E) as shown by indirect immunofluorescence and titration by subpassage. Moreover, a single exposure to wIRA/VIS at 40 hours post infection (hpi) led to a significant reduction of C. pecorum inclusion frequency in Vero cells and C. trachomatis in HeLa cells, respectively. A triple dose of irradiation (24, 36, 40 hpi) during the course of C. trachomatis infection further reduced chlamydial inclusion frequency in HeLa cells without inducing the chlamydial persistence/stress response, as ascertained by electron microscopy. Irradiation of host cells (HeLa, Vero) neither affected cell viability nor induced any molecular markers of cytotoxicity as investigated by Alamar blue assay and Western blot analysis. Chlamydial infection, irradiation, and the combination of both showed a similar release pattern of a subset of pro-inflammatory cytokines (MIF/GIF, Serpin E1, RANTES, IL-6, IL-8) and chemokines (IL-16, IP-10, ENA-78, MIG, MIP-1α/β) from host cells. Initial investigation into the mechanism indicated possible thermal effects on Chlamydia due to irradiation. In summary, we demonstrate a non-chemical reduction of chlamydial infection using the combination of water-filtered

  2. Assessment of Various Organic Matter Properties by Infrared Reflectance Spectroscopy of Sediments and Filters

    Science.gov (United States)

    Alaoui, G.; Leger, M.; Gagne, J.; Tremblay, L.

    2009-05-01

    The goal of this work was to evaluate the capability of infrared reflectance spectroscopy for a fast quantification of the elemental and molecular compositions of sedimentary and particulate organic matter (OM). A partial least-squares (PLS) regression model was used for analysis and values were compared to those obtained by traditional methods (i.e., elemental, humic and HPLC analyses). PLS tools are readily accessible from software such as GRAMS (Thermo-Fisher) used in spectroscopy. This spectroscopic-chemometric approach has several advantages including its rapidity and use of whole unaltered samples. To predict properties, a set of infrared spectra from representative samples must first be fitted to form a PLS calibration model. In this study, a large set (180) of sediments and particles on GFF filters from the St. Lawrence estuarine system were used. These samples are very heterogenous (e.g., various tributaries, terrigenous vs. marine, events such as landslides and floods) and thus represent a challenging test for PLS prediction. For sediments, the infrared spectra were obtained with a diffuse reflectance, or DRIFT, accessory. Sedimentary carbon, nitrogen, humic substance contents as well as humic substance proportions in OM and N:C ratios were predicted by PLS. The relative root mean square error of prediction (%RMSEP) for these properties were between 5.7% (humin content) and 14.1% (total humic substance yield) using the cross-validation, or leave-one out, approach. The %RMSEP calculated by PLS for carbon content was lower with the PLS model (7.6%) than with an external calibration method (11.7%) (Tremblay and Gagné, 2002, Anal. Chem., 74, 2985). Moreover, the PLS approach does not require the extraction of POM needed in external calibration. Results highlighted the importance of using a PLS calibration set representative of the unknown samples (e.g., same area). For filtered particles, the infrared spectra were obtained using a novel approach based on

  3. Single phase bi-directional AC-DC converter with reduced passive components size and common mode electro-magnetic interference

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Chris; Li, Siqi

    2017-01-31

    A bidirectional AC-DC converter is presented with reduced passive component size and common mode electro-magnetic interference. The converter includes an improved input stage formed by two coupled differential inductors, two coupled common and differential inductors, one differential capacitor and two common mode capacitors. With this input structure, the volume, weight and cost of the input stage can be reduced greatly. Additionally, the input current ripple and common mode electro-magnetic interference can be greatly attenuated, so lower switching frequency can be adopted to achieve higher efficiency.

  4. Indium phosphide all air-gap Fabry-Pérot filters for near-infrared spectroscopic applications

    Science.gov (United States)

    Ullah, A.; Butt, M. A.; Fomchenkov, S. A.; Khonina, S. N.

    2016-08-01

    Food quality can be characterized by noninvasive techniques such as spectroscopy in the Near Infrared wavelength range. For example, 930 -1450 nm wavelength range can be used to detect diseases and differentiate between meat samples. Miniaturization of such NIR spectrometers is useful for quick and mobile characterization of food samples. Spectrometers can be miniaturized, without compromising the spectral resolution, using Fabry-Pérot (FP) filters consisting of two highly reflecting mirrors with a central cavity in between. The most commonly used mirrors in the design of FP filters are Distributed Bragg Reflections (DBRs) consisting of alternating high and low refractive index material pairs, due to their high reflectivity compared to metal mirrors. However, DBRs have high reflectivity for a selected range of wavelengths known as the stopband of the DBR. This range is usually much smaller than the sensitivity range of the spectrometer detector. Therefore, a bandpass filter is usually required to restrict wavelengths outside the stopband of the FP DBRs. Such bandpass filters are difficult to design and implement. Alternatively, high index contrast materials must be can be used to broaden the stopband width of the FP DBRs. In this work, Indium phosphide all air-gap filters are proposed in conjunction with InGaAs based detectors. The designed filter has a wide stopband covering the entire InGaAs detector sensitivity range. The filter can be tuned in the 950-1450 nm with single mode operation. The designed filter can hence be used for noninvasive meat quality control.

  5. A small dim infrared maritime target detection algorithm based on local peak detection and pipeline-filtering

    Science.gov (United States)

    Wang, Bin; Dong, Lili; Zhao, Ming; Xu, Wenhai

    2015-12-01

    In order to realize accurate detection for small dim infrared maritime target, this paper proposes a target detection algorithm based on local peak detection and pipeline-filtering. This method firstly extracts some suspected targets through local peak detection and removes most of non-target peaks with self-adaptive threshold process. And then pipeline-filtering is used to eliminate residual interferences so that only real target can be retained. The experiment results prove that this method has high performance on target detection, and its missing alarm rate and false alarm rate can basically meet practical requirements.

  6. Sono-electro-magnetic therapy for treating chronic pelvic pain syndrome in men: a randomized, placebo-controlled, double-blind trial.

    Directory of Open Access Journals (Sweden)

    Thomas M Kessler

    Full Text Available OBJECTIVE: To assess the efficacy and safety of sono-electro-magnetic therapy compared to placebo in men with refractory CPPS. PATIENTS AND METHODS: In a randomized, placebo-controlled, double-blind single center trial, we assessed the effect of sono-electro-magnetic therapy in men with treatment refractory CPPS. Sixty male patients were randomly assigned to treatment with either sono-electro-magnetic (n = 30 or placebo therapy (n = 30 for 12 weeks. The primary outcome was a change in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI from baseline to 12 weeks. RESULTS: The 12-week difference between sono-electro-magnetic and placebo therapy in changes of the NIH-CPSI total score was -3.1 points (95% CI -6.8 to 0.6, p = 0.11. In secondary comparisons of NIH-CPSI sub-scores, we found differences between groups most pronounced for the quality-of-life sub-score (difference at 12 weeks -1.6, 95% CI -2.8 to -0.4, p = 0.015. In stratified analyses, the benefit of sono-electro-magnetic therapy appeared more pronounced among patients who had a symptom duration of 12 months or less (difference in NIH-CPSI total score -8.3, 95% CI -14.5 to 2.6 than in patients with a longer symptom duration (-0.8, 95% CI -4.6 to 3.1; p for interaction = 0.023. CONCLUSIONS: Sono-electro-magnetic therapy did not result in a significant improvement of symptoms in the overall cohort of treatment refractory CPPS patients compared to placebo treatment. Subgroup analysis indicates, however, that patients with a symptom-duration of 12 months or less may benefit from sono-electro-magnetic therapy, warranting larger randomized controlled trials in this subpopulation. TRIAL REGISTRATION: ClinicalTrials.gov NCT00688506.

  7. Size-dependent free vibration and dynamic analyses of piezo-electro-magnetic sandwich nanoplates resting on viscoelastic foundation

    Science.gov (United States)

    Arefi, Mohammad; Zenkour, Ashraf M.

    2017-09-01

    In this paper, size-dependent free vibration analysis of a sandwich nanoplate is presented. The sandwich nanoplate is including an elastic nano core and two piezo-electro-magnetic face-sheets as sensor and actuator actuated by electric and magnetic potentials. The sandwich nanoplate is resting on visco-Pasternak's foundation. Hamilton's principle is employed to derive the governing equations of motion based on Kirchhoff plate and nonlocal elasticity theory. The numerical results are presented to study the influence of important parameters of the problem such as applied electric and magnetic potentials, nonlocal parameter and visco-Pasternak's parameters. Furthermore, the influence of various boundary conditions is discussed on the vibration characteristics of the sandwich nanoplate.

  8. Investigation on improved infrared image detail enhancement algorithm based on adaptive histogram statistical stretching and gradient filtering

    Science.gov (United States)

    Zeng, Bangze; Zhu, Youpan; Li, Zemin; Hu, Dechao; Luo, Lin; Zhao, Deli; Huang, Juan

    2014-11-01

    Duo to infrared image with low contrast, big noise and unclear visual effect, target is very difficult to observed and identified. This paper presents an improved infrared image detail enhancement algorithm based on adaptive histogram statistical stretching and gradient filtering (AHSS-GF). Based on the fact that the human eyes are very sensitive to the edges and lines, the author proposed to extract the details and textures by using the gradient filtering. New histogram could be acquired by calculating the sum of original histogram based on fixed window. With the minimum value for cut-off point, author carried on histogram statistical stretching. After the proper weights given to the details and background, the detail-enhanced results could be acquired finally. The results indicate image contrast could be improved and the details and textures could be enhanced effectively as well.

  9. Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances

    OpenAIRE

    Sterry, Wolfram; Ackermann, Hanns; Hoffmann, Gerd; Schanzer, Sabine; Meyer, Lars; Grone, Diego; Otberg, Nina; Lademann, Jürgen

    2008-01-01

    Background: Water-filtered infrared-A (wIRA) irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone. Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised contr...

  10. Transdermal penetration of topically applied fluorescent dyes with and without the influence of Water Filtered Infrared-A-Radiation

    OpenAIRE

    Grone, Diego

    2010-01-01

    Optical methods were used to investigate the influence of water filtered infrared A radiation (wIRA) on the dermatopharmacokinetics of topically applied substances. The penetration profiles of the hydrophilic dye fluoresceine and the lipophilic dye curcumin in a standard o/w emulsion were determined by tape stripping, in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Three different protocols (mode A-C) were us...

  11. Oil accumulation in intact olive fruits measured by near infrared spectroscopy-acousto-optically tunable filter.

    Science.gov (United States)

    Bellincontro, Andrea; Caruso, Giovanni; Mencarelli, Fabio; Gucci, Riccardo

    2013-04-01

    A field experiment was conducted to test the reliability of the near infrared spectroscopy (NIR)-acousto-optically tunable filter (AOTF) method to measure mesocarp oil content in vivo against nuclear magnetic resonance (NMR) determinations using three different olive cultivars at different stages of ripening. In the partial least squares model carried out for the cultivar 'Arbequina', the coefficient of determination in calibration (R(2)c) was 0.991, while the coefficient of determination in cross-validation (R(2)cv) was 0.979. For the cultivar 'Frantoio' the indexes were 0.982 and 0.971, respectively; while for the cultivar 'Leccino' R(2)c was 0.977 and R(2)cv was 0.965. Finally, for the combined model (sum of the three varieties) these indexes were 0.921 and 0.903, respectively. The residual predictive deviation (RPD) ratio was insufficient for the predictive model of cultivar 'Leccino' only (1.98), whereas in the other cases the RPD ratios were completely sufficient, within the estimation range over 2.5-3 (2.61 in the global model, and 4.23 in the cultivar 'Frantoio'), or in describing a large capacity with values greater than 5, as in the cultivar 'Arbequina' (9.58). NIR-AOTF spectroscopy proved to be a novel, rapid and reliable method to monitor the oil accumulation process in intact olive fruits in the field. The innovative approach of coupling NIR and NMR technologies opens up new scenarios for determining the optimal time for harvesting olive trees to obtain maximum oil production. © 2012 Society of Chemical Industry.

  12. Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight.

    Directory of Open Access Journals (Sweden)

    Gautier eDurantin

    2016-01-01

    Full Text Available Working memory is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor working memory as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces. We used functional near infrared spectroscopy as it has been already successfully tested to measure working memory capacity in complex environment with air traffic controllers, pilots or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with 9 participants involving a basic working memory task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with air traffic controller instructions (two levels of difficulty. The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in working

  13. Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight.

    Science.gov (United States)

    Durantin, Gautier; Scannella, Sébastien; Gateau, Thibault; Delorme, Arnaud; Dehais, Frédéric

    2015-01-01

    Working memory (WM) is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor WM as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering, and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces (BCI). We used functional near infrared spectroscopy as it has been already successfully tested to measure WM capacity in complex environment with air traffic controllers (ATC), pilots, or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with nine participants involving a basic WM task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with ATC instructions (two levels of difficulty). The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence (MACD) filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in WM. In addition, the use of a Kalman filter increased

  14. 基于背景最佳滤波尺度的红外图像复杂度评价准则∗%An evaluation criterion of infrared image complexity based on background optimal filter scale

    Institute of Scientific and Technical Information of China (English)

    侯旺; 梅风华; 陈国军; 邓喜文

    2015-01-01

    An evaluation of infrared image complexity is proposed based on the background optimal filtering to solve the problem that the traditional methods have given poor results in the background evaluation. Meanwhile, the optimal filtering scale for infrared image filtering can be given by this method, it will provide a guidance for optimal infrared image filtering. First, we generate the Gaussian simulated target and fuse it to the infrared image to obtain the real infrared image with the simulated target. Then, this image is filtered in different scales and the signal-to-noise ratio of the target after filtering is calculated. Finally, the maximal value of signal-to-noise ratio of the target is used as the background optimal filter scale, to evaluate the infrared image complexity. Besides, the infrared filtering scale is deduced by establishing the mathematic model, and then the mathematical expression of optimal filtering scale is obtained. A lot of experiments indicate that: 1) The mathematical expression of optimal filtering scale agrees with the experimental results. 2) The result of our method is better than that of the traditional methods based on information entropy. Because the optimal filtering scale is obtained by using our method, we can use this scale to filter the infrared image to effectively detect a small target. 3) When the scale of simulated target increases, the optimal filtering scale increases accordingly. So, when we calculate the infrared image complexity, the scale of simulated target must be the same. We can compare the infrared image complexity between different images. Moreover, the optimal filtering scale is independent of the intensity of simulated target. 4) The effect of Gaussian and Butterworth high-pass filter is better than that of the ideal high-pass filter in the proposed method. 5) The infrared image complexity can be analyzed by the proposed method effectively. Moreover, changes of different image contents can be analyzed by using

  15. Guided filter and adaptive learning rate based non-uniformity correction algorithm for infrared focal plane array

    Science.gov (United States)

    Sheng-Hui, Rong; Hui-Xin, Zhou; Han-Lin, Qin; Rui, Lai; Kun, Qian

    2016-05-01

    Imaging non-uniformity of infrared focal plane array (IRFPA) behaves as fixed-pattern noise superimposed on the image, which affects the imaging quality of infrared system seriously. In scene-based non-uniformity correction methods, the drawbacks of ghosting artifacts and image blurring affect the sensitivity of the IRFPA imaging system seriously and decrease the image quality visibly. This paper proposes an improved neural network non-uniformity correction method with adaptive learning rate. On the one hand, using guided filter, the proposed algorithm decreases the effect of ghosting artifacts. On the other hand, due to the inappropriate learning rate is the main reason of image blurring, the proposed algorithm utilizes an adaptive learning rate with a temporal domain factor to eliminate the effect of image blurring. In short, the proposed algorithm combines the merits of the guided filter and the adaptive learning rate. Several real and simulated infrared image sequences are utilized to verify the performance of the proposed algorithm. The experiment results indicate that the proposed algorithm can not only reduce the non-uniformity with less ghosting artifacts but also overcome the problems of image blurring in static areas.

  16. An automated baseline correction protocol for infrared spectra of atmospheric aerosols collected on polytetrafluoroethylene (Teflon) filters

    Science.gov (United States)

    Kuzmiakova, Adele; Dillner, Ann M.; Takahama, Satoshi

    2016-06-01

    A growing body of research on statistical applications for characterization of atmospheric aerosol Fourier transform infrared (FT-IR) samples collected on polytetrafluoroethylene (PTFE) filters (e.g., Russell et al., 2011; Ruthenburg et al., 2014) and a rising interest in analyzing FT-IR samples collected by air quality monitoring networks call for an automated PTFE baseline correction solution. The existing polynomial technique (Takahama et al., 2013) is not scalable to a project with a large number of aerosol samples because it contains many parameters and requires expert intervention. Therefore, the question of how to develop an automated method for baseline correcting hundreds to thousands of ambient aerosol spectra given the variability in both environmental mixture composition and PTFE baselines remains. This study approaches the question by detailing the statistical protocol, which allows for the precise definition of analyte and background subregions, applies nonparametric smoothing splines to reproduce sample-specific PTFE variations, and integrates performance metrics from atmospheric aerosol and blank samples alike in the smoothing parameter selection. Referencing 794 atmospheric aerosol samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011, we start by identifying key FT-IR signal characteristics, such as non-negative absorbance or analyte segment transformation, to capture sample-specific transitions between background and analyte. While referring to qualitative properties of PTFE background, the goal of smoothing splines interpolation is to learn the baseline structure in the background region to predict the baseline structure in the analyte region. We then validate the model by comparing smoothing splines baseline-corrected spectra with uncorrected and polynomial baseline (PB)-corrected equivalents via three statistical applications: (1) clustering analysis, (2) functional group quantification

  17. Asynchronous Electric Motor with Built-in Combined Braking Device Based on Electro-Mechanical Brake and Electro-Magnetic Clutch

    OpenAIRE

    V. V. Solenkov; Brel, V. V.

    2011-01-01

    The paper shows advantages and disadvantages of the known designs of asynchronous motors with electro-mechanical braking device. A new developed and studied asynchronous motor design with built-in combined braking device based on an electro-mechanical brake and an electro-magnetic clutch is given in the paper. The paper describes its advantages and prospects of its usage for electric drives operating in intermittent cycle.

  18. Asynchronous Electric Motor with Built-in Combined Braking Device Based on Electro-Mechanical Brake and Electro-Magnetic Clutch

    Directory of Open Access Journals (Sweden)

    V. V. Solenkov

    2011-01-01

    Full Text Available The paper shows advantages and disadvantages of the known designs of asynchronous motors with electro-mechanical braking device. A new developed and studied asynchronous motor design with built-in combined braking device based on an electro-mechanical brake and an electro-magnetic clutch is given in the paper. The paper describes its advantages and prospects of its usage for electric drives operating in intermittent cycle.

  19. Characterization of Deep Geothermal Energy Resources in Low enthalpy sedimentary basins in Belgium using Electro-Magnetic Methods – CSEM and MT results

    OpenAIRE

    Coppo, Nicolas; DARNET, Mathieu; Harcouet-Menou, Virginie; Wawrzyniak, Pierre; Manzella, Adele; Bretaudeau, François; G. Romano; Lagrou, D.; Girard, Jean-Francois

    2016-01-01

    International audience; Sedimentary basins in Northwest Europe have significant potential for low to medium enthalpy, deep geothermal energy resources. These resources are generally assessed using standard seismic exploration techniques to resolve geological structures. The ElectroMagnetic campaign carried-out in Mol area (Belgium) has shown that despite the presence of high level of industrialization, the resistivity of deep formations (>3km) can be recovered from MT and CSEM methods and hen...

  20. Two-layer anti-reflection coating with mullite and polyimide foam for large-diameter cryogenic infrared filters.

    Science.gov (United States)

    Inoue, Yuki; Hamada, Takaho; Hasegawa, Masaya; Hazumi, Masashi; Hori, Yasuto; Suzuki, Aritoki; Tomaru, Takayuki; Matsumura, Tomotake; Sakata, Toshifumi; Minamoto, Tomoyuki; Hirai, Tohru

    2016-12-01

    We have developed a novel two-layer anti-reflection (AR) coating method for large-diameter infrared (IR) filters made of alumina, for use at cryogenic temperatures in millimeter wave measurements. Thermally sprayed mullite and polyimide foam (Skybond Foam) are used as the AR material. An advantage of the Skybond Foam is that the index of refraction is chosen between 1.1 and 1.7 by changing the filling factor. Combination with mullite is suitable for wide-band millimeter wave measurements with sufficient IR cutoff capability. We present the material properties, fabrication of a large-diameter IR filter made of alumina with this AR coating method, and characterizations at cryogenic temperatures. This technology can be applied to a low-temperature receiver system with a large-diameter focal plane for next-generation cosmic microwave background polarization measurements, such as POLARBEAR-2 (PB-2).

  1. Two-layer anti-reflection coating with mullite and polyimide foam for large-diameter cryogenic infrared filters

    CERN Document Server

    Inoue, Yuki; Hasegawa, Masaya; Hazumi, Masashi; Hori, Yasuto; Suzuki, Aritoki; Tomaru, Takayuki; Matsumura, Tomotake; Sakata, Toshifumi; Minamoto, Tomoyuki; Hirai, Tohru

    2016-01-01

    We have developed a novel two-layer anti-reflection (AR) coating method for large-diameter infrared (IR) filters made of alumina, for the use at cryogenic temperatures in millimeter wave measurements. Thermally- sprayed mullite and polyimide foam (Skybond Foam) are used as the AR material. An advantage of the Skybond Foam is that the index of refraction is chosen between 1.1 and 1.7 by changing the filling factor. Combination with mullite is suitable for wide-band millimeter wave measurements with sufficient IR cutoff capability. We present the material properties, fabrication of a large-diameter IR filter made of alumina with this AR coating method, and characterizations at cryogenic temperatures. This technology can be applied to a low-temperature receiver system with a large-diameter focal plane for next-generation cosmic microwave background (CMB) polarization measurements, such as POLARBEAR-2 (PB-2).

  2. The multi-filter rotating shadowband radiometer (MFRSR) - precision infrared radiometer (PIR) platform in Fairbanks: Scientific objectives

    Energy Technology Data Exchange (ETDEWEB)

    Stamnes, K.; Leontieva, E. [Univ. of Alaska, Fairbanks (United States)

    1996-04-01

    The multi-filter rotating shadowband radiometer (MFRSR) and precision infrared radiometer (PIR) have been employed at the Geophysical Institute in Fairbanks to check their performance under arctic conditions. Drawing on the experience of the previous measurements in the Arctic, the PIR was equipped with a ventilator to prevent frost and moisture build-up. We adopted the Solar Infrared Observing Sytem (SIROS) concept from the Southern Great Plains Cloud and Radiation Testbed (CART) to allow implementation of the same data processing software for a set of radiation and meteorological instruments. To validate the level of performance of the whole SIROS prior to its incorporation into the North Slope of Alaska (NSA) Cloud and Radiation Testbed Site instrumental suite for flux radiatin measurements, the comparison between measurements and model predictions will be undertaken to assess the MFRSR-PIR Arctic data quality.

  3. Infrared hyperspectral tunable filter imaging spectrometer for remote leak detection, chemical speciation, and stack/vent analysis applications

    Science.gov (United States)

    Hinnrichs, Michele

    2002-02-01

    With support from the Department of Energy, the State of California and the Gas Technology Institute, Pacific Advanced Technology is developing a small field portable infrared imaging spectrometer (Sherlock) based on the advances in hyperspectral tunable filter technology, that will be applied to the detection of fugitive gas leaks. This imaging spectrometer uses the Image Multi-spectral Sensing (IMSS) diffractive optic tunable filter invented by Pacific Advanced Technology . The Sherlock has an embedded digital signal processor for real time detection of the gas leak while surrounded by severe background noise. The infrared sensor engine is a 256 x 320 midwave cooled focal plane array which spans the spectral range from 3 to 5 microns, ideal for most hydrocarbon leaks. The technology is by no means limited to this spectral region, and can just as easily work in the longwave infrared from 8 to 12 microns for chemical detection applications. This paper will present the design of the Sherlock camera as well as processed data collected at a gas processing plant and an instrumented kiln at LSU using the prototype camera. The processed data shows that the IMSS imaging spectrometer, using an all passive approach, has the sensitivity to detect methane gas leaks at short range with a flow rate as low as 0.01 scfm2. In addition, the IMSS imaging spectrometer can measure hot gas plumes at longer ranges. As will be shown in this paper the IMSS can detect and image warm species gas additives of methane and propane in the Kiln exhaust stack. The methane injected gas with a concentration of 72 ppm and the propane with a concentration of 49 ppm (as seen by the IMSS sensor) at a range of 60 meters. The atmospheric path was a stressing environment, being hot and humid, for any imaging infrared spectrometer.

  4. Sol-gel-derived Hybrid Conductive Films for Electro magnetic Interference (EMI) Shielding

    Institute of Scientific and Technical Information of China (English)

    XIE Jiyuan; GUO Wenfeng; WANG Jianzhong

    2011-01-01

    The conductive nano-sized zinc particles were embedded in an insulating amorphous silica matrix, and the hybrid films were obtained by a sol-gel method. The stable hybrid sol solution was prepared by hydrolysis and condensation of Methyltrimethoxysilane (MTMS) with a one-step acidic catalyst process. Hybrid films were dip-coated on silicon wafer and cured at 120 ℃ for 60minutes. The structural characterization of hybrid films were investigated by means of attenuated total reflection infrared (ATR-IR) spectroscopy and X-ray diffraetion (XRD). The electrical properties of the films were examined with four-point probe. Hybrid films showed to be relatively dense, uniform and defect free. The conductivity of hybrid films was varied with the different contents of zinc nanoparticles and the thickness of the film. It was observed that there was the percolation threshold for the film's electrical properties.

  5. Suppression of Sidelobe for Acousto-Optic Tunable Filter in Near-Infrared Spectral Monitoring

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper we calculated the acoustic intensity distribution of different transducers, and designed acousto-optic tunable filter(AOTF) based on different transducers. Through the experiment, we find sidelobe can be reduced by changing the transducer geometry.

  6. Evaluation of hydrazine reduction by cellulose acetate filters using infrared tunable diode laser spectroscopy.

    Science.gov (United States)

    Harward, Charles N; Parrish, Milton E; Plunkett, Susan E; Banyasz, Joseph L; Shafer, Kenneth H

    2002-11-15

    Cellulose acetate (CA) filters have been investigated to determine their hydrazine (N2H4) breakthrough characteristics using a system based on tunable diode laser absorption spectroscopy (TDIAS). The breakthrough mass loading sorption curves for hydrazine were dependent on both the flow rate and the concentration. In experiments using a 4.5 ppmv hydrazine standard, the amounts of hydrazine retained by the CA filter were 4.25 microg at a flow rate of 2.82 L/min and 65 microg at a flow rate of 0.28 L/min. These loadings are much greater than the 31.5 ng/cigarette of hydrazine reported in smoke for unfiltered cigarettes. Further, CA filters exposed to four and eight puffs of smoke actually made the filter more efficient in retaining hydrazine compared to CA filters that had not been exposed to smoke. Therefore, if hydrazine is present in smoke at the levels reported in unfiltered cigarettes, all of the hydrazine would be trapped by the CA filter, and would be unable to break through during smoking. A unique feature of this analytical method is that the instrument does not require calibration after molecular parameters have been determined, in this case from previously acquired quantitative hydrazine FT-IR reference spectra.

  7. Bio-Inspired Dynamically Tunable Polymer-Based Filters for Multi-Spectral Infrared Imaging

    Science.gov (United States)

    2010-05-01

    Morse. Plastic Transmissive Infrared Electrochromic Devices , Macromolecular Chemistry and Physics, (07 2010): 0. doi: 10.1002/macp.201000096 2011/10/10...Publication: Holt, A.L., J. G. A. Wehner, A. Hammp and D. E. Morse. 2010. Plastic transmissive infrared electrochromic devices ...Level Device Design ( Electrochromic -Based IR Shutter): The first initiative in the device design work consisted of determining a standard device

  8. Fluid-controlled tunable infrared filtering in hollow plasmonic nanofin cavities

    Science.gov (United States)

    Ho, Ya-Lun; Abasaki, Minoru; Yin, Shichen; Liu, Xin; Delaunay, Jean-Jacques

    2016-10-01

    Subwavelength structures sustaining surface plasmons have been employed in numerous fields due to their small size and ability to manipulate light beyond the diffraction limit. Light filtering using small-size plasmonic devices is a promising means of portable spectroscopy for purposes such as on-site chemical analyses. However, most plasmonic filters can only tune the resonance band by modifying the geometry of the structure or changing the incident light angle. Here, we present a plasmonic nanofin-cavity structure having a narrow band with its resonance wavelength controlled by varying the fluid in the hollow cavities of the filter. Control of the narrow-band resonance is realized over a wide range because of the coupling between the stationary surface plasmons generated from the nanofin-cavity mode and the propagating surface plasmons. The hollow cavity design enables fluid to be easily injected and removed, so that the filtered band can be controlled without the need for a complex and bulky structure or application of an external voltage.

  9. Improved total atmospheric water vapour amount determination from near-infrared filter measurements with sun photometers

    Directory of Open Access Journals (Sweden)

    F. Mavromatakis

    2007-05-01

    Full Text Available In this work we explore the effect of the contribution of the solar spectrum to the recorded signal in wavelengths outside the typical 940-nm filter's bandwidth. We use gaussian-shaped filters as well as actual filter transmission curves to study the implications imposed by the non-zero out-of-band contribution to the coefficients used to derive precipitable water from the measured water vapour band transmittance. The moderate-resolution SMARTS radiative transfer code is used to predict the incident spectrum outside the filter bandpass for different atmospheres, solar geometries and aerosol optical depths. The high-resolution LBLRTM radiative transfer code is used to calculate the water vapour transmittance in the 940 nm band. The absolute level of the out-of-band transmittance has been chosen to range from 10−6 to 10−4, and typical response curves of commercially available silicon photodiodes are included into the calculations. It is shown that if the out-of-band transmittance effect is neglected, as is generally the case, then the derived columnar water vapour is systematically underestimated by a few percents. The actual error depends on the specific out-of-band transmittance, optical air mass of observation and water vapour amount. We apply published parameterized transmittance functions to determine the filter coefficients. We also introduce an improved, three-parameter, fitting function that can describe the theoretical data accurately, with significantly less residual effects than with the existing functions. Further investigations will use experimental data from field campaigns to validate these findings.

  10. Guided filter and convolutional network based tracking for infrared dim moving target

    Science.gov (United States)

    Qian, Kun; Zhou, Huixin; Qin, Hanlin; Rong, Shenghui; Zhao, Dong; Du, Juan

    2017-09-01

    The dim moving target usually submerges in strong noise, and its motion observability is debased by numerous false alarms for low signal-to-noise ratio. A tracking algorithm that integrates the Guided Image Filter (GIF) and the Convolutional neural network (CNN) into the particle filter framework is presented to cope with the uncertainty of dim targets. First, the initial target template is treated as a guidance to filter incoming templates depending on similarities between the guidance and candidate templates. The GIF algorithm utilizes the structure in the guidance and performs as an edge-preserving smoothing operator. Therefore, the guidance helps to preserve the detail of valuable templates and makes inaccurate ones blurry, alleviating the tracking deviation effectively. Besides, the two-layer CNN method is adopted to obtain a powerful appearance representation. Subsequently, a Bayesian classifier is trained with these discriminative yet strong features. Moreover, an adaptive learning factor is introduced to prevent the update of classifier's parameters when a target undergoes sever background. At last, classifier responses of particles are utilized to generate particle importance weights and a re-sample procedure preserves samples according to the weight. In the predication stage, a 2-order transition model considers the target velocity to estimate current position. Experimental results demonstrate that the presented algorithm outperforms several relative algorithms in the accuracy.

  11. Water-filtered infrared-A (wIRA can act as a penetration enhancer for topically applied substances

    Directory of Open Access Journals (Sweden)

    Sterry, Wolfram

    2008-07-01

    Full Text Available Background: Water-filtered infrared-A (wIRA irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone. Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised controlled study in humans. Methods: The penetration profiles of the hydrophilic dye fluorescein and the lipophilic dye curcumin in separate standard water-in-oil emulsions were determined on the inner forearm of test persons by tape stripping in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Transepidermal water loss, hydration of the epidermis, and surface temperature were determined. Three different procedures (modes A, B, C were used in a randomised order on three separate days of investigation in each of 12 test persons. In mode A, the two dyes were applied on different skin areas without water-filtered infrared-A (wIRA irradiation. In mode B, the skin surface was irradiated with wIRA over 30 min before application of the two dyes (Hydrosun® radiator type 501, 10 mm water cuvette, orange filter OG590, water-filtered spectrum: 590–1400 nm with dominant amount of wIRA. In mode C, the two dyes were applied and immediately afterwards the skin was irradiated with wIRA over 30 min. In all modes, tape stripping started 30 min after application of the formulations. Main variable of interest was the ratio of the amount of the dye in the deeper (second 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum. Results: The penetration profiles of the hydrophilic fluorescein showed in case of pretreatment or treatment with wIRA (modes B and C an

  12. Detecting slowly moving infrared targets using temporal filtering and association strategy

    Institute of Scientific and Technical Information of China (English)

    Jing-li GAO; Cheng-lin WEN; Zhe-jing BAO; Mei-qin LIU

    2016-01-01

    The special characteristics of slowly moving infrared targets, such as containing only a few pixels, shapeless edge, low signal-to-clutter ratio, and low speed, make their detection rather difficult, especially when immersed in complex backgrounds. To cope with this problem, we propose an effective infrared target detection algorithm based on temporal target detection and association strategy. First, a temporal target detection model is developed to segment the interested targets. This model contains mainly three stages, i.e., temporal fi ltering, temporal target fusion, and cross-product fi ltering. Then a graph matching model is presented to associate the targets obtained at different times. The association relies on the motion characteristics and appearance of targets, and the association operation is performed many times to form continuous trajectories which can be used to help disambiguate targets from false alarms caused by random noise or clutter. Experimental results show that the proposed method can detect slowly moving infrared targets in complex backgrounds accurately and robustly, and has superior detection performance in comparison with several recent methods.

  13. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

  14. Modal Filtering for Nulling Interferometry-First Single-Mode Conductive Waveguides in the Mid-Infrared

    CERN Document Server

    Labadie, L; Kern, P; Schanen, I; Arezki, B; Broquin, J E

    2005-01-01

    This paper presents the work achieved for the manufacturing and characterization of first single-mode waveguides to be used as modal filters for nulling interferometry in the mid-infrared range [4-20 um]. As very high dynamic range is mandatory for detection of Earth-like planets, modal filtering is one of the most stringent instrumental aspects. The hollow metallic waveguides (HMW) presented here are manufactured using micro-machining techniques. Single-mode behavior has been investigated in laboratory through a technique of polarization analysis while transmission features have been measured using flux relative comparison. The single-mode behavior have been assessed at lambda=10.6 um for rectangular waveguides with dimensions a=10 um and b<5.3 um with an accuracy of ~2.5 %. The tests have shown that a single-polarization state can be maintained in the waveguide. A comparison with results on multi-mode HMW is proposed. Excess losses of 2.4 dB (~ 58 % transmission) have been measured for a single-mode wave...

  15. Bridge recognition based on Gabor filter in forward-looking infrared images

    Science.gov (United States)

    Liu, Songlin; Sun, Gang; Niu, Zhaodong; Chen, Zengping

    2013-10-01

    Conventional methods often assume that water region is homogeneous and bridge is brighter than background. They usually recognize target by parallel lines detection. But grayscale of bridge has bipolar problem in FLIR images due to interference of complex background and constraints of imaging conditions, which means that it can be greater or lower than river. Furthermore, water is not a homogeneous area as a whole because of the interference of water clutter and shoals. This paper proposes a novel algorithm of bridge recognition based on Gabor filter. Firstly, we obtain target ROI by extracting the horizontal line. And then ROI sub-images are enhanced by Gabor filter and target polarity is determined by bridge body detection. Finally, bridge recognition can be achieved by pier detection according to the target polarity and location of bridge body. Experimental results of nearly 3000 frames show that the proposed algorithm can effectively overcome problems such as bipolar target and low image contrast. It offers a good practicability and accuracy in bridge recognition in FLIR images.

  16. Electrically tunable infrared filter based on the liquid crystal Fabry-Perot structure for spectral imaging detection.

    Science.gov (United States)

    Zhang, Huaidong; Muhammmad, Afzal; Luo, Jun; Tong, Qing; Lei, Yu; Zhang, Xinyu; Sang, Hongshi; Xie, Changsheng

    2014-09-01

    An electrically tunable infrared (IR) filter based on the liquid crystal (LC) Fabry-Perot (FP) key structure, which works in the wavelength range from 5.5 to 12 μm, is designed and fabricated successfully. Both planar reflective mirrors with a very high reflectivity of ∼95%, which are shaped by depositing a layer of aluminum (Al) film over one side of a double-sided polished zinc selenide wafer, are coupled into a dual-mirror FP cavity. The LC materials are filled into the FP cavity with a thickness of ∼7.5  μm for constructing the LC-FP filter, which is a typical type of sandwich architecture. The top and bottom mirrors of the FP cavity are further coated by an alignment layer with a thickness of ∼100  nm over Al film. The formed alignment layer is rubbed strongly to shape relatively deep V-grooves to anchor LC molecules effectively. Common optical tests show some particular properties; for instance, the existing three transmission peaks in the measured wavelength range, the minimum full width at half-maximum being ∼120  nm, and the maximum adjustment extent of the imaging wavelength being ∼500  nm through applying the voltage driving signal with a root mean square (RMS) value ranging from 0 to ∼19.8  V. The experiment results are consistent with the simulation, according to our model setup. The spectral images obtained in the long-wavelength IR range, through the LC-FP device driven by the voltage signal with a different RMS value, demonstrates the prospect of the realization of smart spectral imaging and further integrating the LC-FP filter with IR focal plane arrays. The developed LC-FP filters show some advantages, such as electrically tunable imaging wavelength, very high structural and photoelectronic response stability, small size and low power consumption, and a very high filling factor of more than 95% compared with common MEMS-FP spectral imaging approaches.

  17. 电力系统电磁晢态萘酯理论研究%Research on Power System Electro-magnetic Transient Basic Theory

    Institute of Scientific and Technical Information of China (English)

    张健康; 卢志伟

    2011-01-01

    破坏电力系统的正常运行多半是短路故障引起的,如大的短路电流使元件破损,电压的骤降造成系统解裂甚至崩溃以及对周围设备的电磁干扰等.发生短路时,系统从一种状态到另一种状态,并伴随复杂的电磁暂态现象.所以,有必要对电力系统发生故障时的电磁暂态进行分析.%The normal operation damage of the power system are caused mostly by short-circuit , such as large short-circuit current, voltage to components damage caused by system solution plunged to crack even collapse, surrounding equipment and electromagnetic interference, etc. Short-circuited, the system change from one state to another state, accompanied by producing complex electro-magnetic transient phenomena. So it is inevitable that power system fault happens when the electro-magnetic transient analysis.

  18. Dual multi-scale filter with SSS and GW for infrared small target detection

    Science.gov (United States)

    Xin, Yun-hong; Zhou, Jiao; Chen, Yi-shuan

    2017-03-01

    Multi-scale analysis is a powerful tool in the field of signal processing. In this paper, we propose an efficient small target detection algorithm that is mainly based on the dual multi-scale filters which work sequentially. The algorithm consists of two stages: at the first stage, Spectrum Scale-Space (SSS) is used as the pre-process procedure to obtain the multi-scale saliency maps, which can suppress the low frequency background noise and make the target region prominently at different scale levels. As a result, the more detail information and feature information can be exhibited in the different decomposition image level. After then, the least information entropy is used as the criterion to select the optimal salient map out; At the second stage, the Gabor wavelets (GW) algorithm is utilized to suppress the high frequency noise remained in the optimal salient map and match the feature of size and direction of small target at different scales and angles, and next, to ensure the robustness of the target detection, Non-negative Matrix Factorization (NMF) is applied to fuse all the GW multi-scale images into one optimal target image, which is the final output of the presented method. Experimental results show that, compared with the contrast method, the proposed algorithm has high SCRG and high correct target detection rate, and works well in different types of complex backgrounds.

  19. Kalman filter physical retrieval of surface emissivity and temperature from SEVIRI infrared channels: a validation and inter-comparison study

    Directory of Open Access Journals (Sweden)

    G. Masiello

    2015-04-01

    Full Text Available A Kalman filter based approach for the physical retrieval of surface temperature and emissivity from SEVIRI (Spinning Enhanced Visible and Infrared Imager infrared observations has been developed and validated against in situ and satellite observations. Validation for land has been provided based on in situ observations from the two permanent stations Evora and Gobabeb operated by Karlsruhe Institute of Technology (KIT within the framework of EUMETSAT's Satellite Application Facility on Land Surface Analysis (LSA-SAF. Sea surface retrievals have been intercompared on a broad spatial scale with equivalent satellite products (MODIS or Moderate Resolution Imaging Spectroradiometer and AVHRR or Advanced Very High Resolution Radiometer and ECMWF (European Centre for Medium Range Weather Forecasts analyses. Results show that for surface temperature the algorithm yields an accuracy of ≈ ± 1.5 °C in case of land and ≈ ± 1.0 °C in case of sea surface. Comparisons with polar satellite instruments over the sea surface show nearly zero temperature bias. Over the land surface the retrieved emissivity follows the seasonal vegetation cycle and allows to identify desert sand regions because of strong reststrahlen bands of Quartz in the SEVIRI channel at 8.7 μm. Considering the two validation stations, we have that emissivity retrieved in SEVIRI channel 10.8 μm over the gravel plains of the Namib desert is in excellent agreement with in situ observations. Over Evora, the seasonal variation of emissivity with vegetation is successfully retrieved and yields emissivity values for green and dry vegetation that are in good agreement with spectral library data. The algorithm has been applied to the SEVIRI full disk and emissivity maps on that global scale have been physically retrieved for the first time.

  20. Contribution of Heliborne Electro-Magnetic survey for landslide prediction: application to La Martinique (West Indies, France)

    Science.gov (United States)

    Thiery, Yannick; Reninger, Pierre-Alexandre; Vandromme, Rosalie; Nachbaur, Aude

    2017-04-01

    Landslide hazard and risk assessment (LHA & LRA) in French West Indies is a big challenge, because of several factors contributing to high sensitivity of slopes to landslide (complex weathered volcanic grounds, hurricane seasons, heavy land pressure).The initial step is to assess the spatial probability (and sometimes temporal) of failure (i.e. landslide susceptibility assessment; LSA) for a given area. LSA can be evaluated by several approaches (i.e. knowledge approach, data-driven approach, physically based approach). Physically based approaches are used to calculate a slope stability factor taking into account mechanical, geotechnical, hydrological and hydrogeological parameters. However, the parametrization of these models can be difficult because of a lack of information (i.e. soil depths, precipitations chronicles, lithology sometimes due to a difficult ground access, particularly in French Indies. Thus, HEM (Heliborne Electro-Magnetic Survey) appears as a solution to obtain specific information quickly and over large areas. Since 2000, the HEM method is increasingly used for environmental studies: geomorphological and hydrogeological studies. In 2013, The French Geological Survey conducted an HEM survey over La Martinique (West Indies). Resistivity contrasts were imaged up 250-300 meters depth with a horizontal resolution around 30 m and a vertical resolution between 3 and 8 m. Even if the resistivity has not a straightforward relationship with soil mechanical properties (which are key parameters for LHA) it provides relevant information on both the thickness and the extension of formations. The aim of this study is to evaluate the contribution of HEM survey to recognize landslide prone areas and landslide prone formations in volcanic environment. Once the different formations defined, they are introduced in a physically based model to assess the susceptibility of slope for different landslide types with hydrogeological control. The methodology is split in

  1. Water-filtered infrared-A radiation (wIRA is not implicated in cellular degeneration of human skin

    Directory of Open Access Journals (Sweden)

    Applegate, Lee Ann

    2007-11-01

    Full Text Available Background: Excessive exposure to solar ultraviolet radiation is involved in the complex biologic process of cutaneous aging. Wavelengths in the ultraviolet-A and -B range (UV-A and UV-B have been shown to be responsible for the induction of proteases, e. g. the collagenase matrix metalloproteinase 1 (MMP-1, which are related to cell aging. As devices emitting longer wavelengths are widely used in therapeutic and cosmetic interventions and as the induction of MMP-1 by water-filtered infrared-A (wIRA had been discussed, it was of interest to assess effects of wIRA on the cellular and molecular level known to be possibly involved in cutaneous degeneration. Objectives: Investigation of the biological implications of widely used water-filtered infrared-A (wIRA radiators for clinical use on human skin fibroblasts assessed by MMP-1 gene expression (MMP-1 messenger ribonucleic acid (mRNA expression. Methods: Human skin fibroblasts were irradiated with approximately 88% wIRA (780-1400 nm and 12% red light (RL, 665-780 nm with 380 mW/cm² wIRA(+RL (333 mW/cm² wIRA on the one hand and for comparison with UV-A (330-400 nm, mainly UV-A1 and a small amount of blue light (BL, 400-450 nm with 28 mW/cm² UV-A(+BL on the other hand. Survival curves were established by colony forming ability after single exposures between 15 minutes and 8 hours to wIRA(+RL (340-10880 J/cm² wIRA(+RL, 300-9600 J/cm² wIRA or 15-45 minutes to UV-A(+BL (25-75 J/cm² UV-A(+BL. Both conventional Reverse Transcriptase Polymerase Chain Reaction (RT-PCR and quantitative real-time RT-PCR techniques were used to determine the induction of MMP-1 mRNA at two physiologic temperatures for skin fibroblasts (30°C and 37°C in single exposure regimens (15-60 minutes wIRA(+RL, 340-1360 J/cm² wIRA(+RL, 300-1200 J/cm² wIRA; 30 minutes UV-A(+BL, 50 J/cm² UV-A(+BL and in addition at 30°C in a repeated exposure protocol (up to 10 times 15 minutes wIRA(+RL with 340 J/cm² wIRA(+RL, 300 J/cm² w

  2. Water-filtered near-infrared influences collagen synthesis of keloid-fibroblasts in contrast to normal foreskin fibroblasts.

    Science.gov (United States)

    Zöller, Nadja; König, Anke; Butting, Manuel; Kaufmann, Roland; Bernd, August; Valesky, Eva; Kippenberger, Stefan

    2016-10-01

    Hypertrophic scar development is associated to impaired wound healing, imbalanced fibroblast proliferation and extracellular matrix synthesis. Stigmatization, physical restrictions and high recurrence rates are only some aspects that illustrate the severe influence impaired wound healing can have on patients' life. The treatment of hypertrophic scars especially keloids is still a challenge. In recent years water-filtered near-infrared irradiation (wIRA) composed of near-infrared (NIR) and a thermal component is applied for an increasing penal of clinical purposes. It is described to beneficially influence e.g. wound healing. But discrimination between the thermal and the NIR dependent components of these effects has not been conclusively elucidated. Aim of our study was therefore to investigate the influence of the light fraction on the thermal impact of wIRA irradiation in dermal cells. We concentrated our analysis on morphological properties and collagen synthesis. Foreskin fibroblasts and the keloid fibroblast cell line KF111 were exposed to temperatures between 37°C and 46°C with or without additional irradiation with 360J/cm(2) NIR. Our results show that viability was not influenced by irradiation. Independent of the analysed fibroblast species temperature dependent occurrence of spheric cells could be observed. These morphological changes were clearly counteracted by additional light exposure. Convective heat reduced collagen type I synthesis in both cell species depending on the applied temperature. Co-treatment with NIR significantly reversed this effect in keloid fibroblast cultures treated at 46°C whereas no difference could be observed in the foreskin fibroblasts. The observed influence on collagen type I synthesis was associated to a temperature dependent TGF-β1 secretion reduction. Co-stimulation of keloid cultures with NIR at 46°C completely abolished the temperature dependent TGF-β1 secretion reduction. In foreskin fibroblast cultures co

  3. Water-filtered infrared-A (wIRA overcomes swallowing disorders and hypersalivation – a case report

    Directory of Open Access Journals (Sweden)

    Hoffmann, Gerd

    2017-08-01

    Full Text Available Case description: A patient with a Barrett oesophageal carcinoma and a resection of the oesophagus with gastric pull-up developed swallowing disorders 6 years and 2 months after the operation. Within 1 year and 7 months two recurrences of the tumor at the anastomosis were found and treated with combined chemoradiotherapy or chemotherapy respectively. 7 years and 9 months after the operation local tumor masses and destruction were present with no ability to orally drink or eat (full feeding by jejunal PEG tube: quality of life was poor, as saliva and mucus were very viscous (pulling filaments and could not be swallowed and had to be spat out throughout the day and night resulting in short periods of sleep (awaking from the necessity to spit out. In total the situation was interpreted more as a problem related to a feeling of choking (with food or fluid in the sense of a functional dysphagia rather than as a swallowing disorder from a structural stenosis. At that time acetylcysteine (2 times 200 mg per day, given via the PEG tube and irradiation with water-filtered infrared-A (wIRA, a special form of heat radiation, of the ventral part of the neck and the thorax were added to the therapy. Within 1 day with acetylcysteine saliva and mucus became less viscous. Within 2 days with wIRA (one day with 4 to 5 hours with irradiation with wIRA at home salivation decreased markedly and quality of life clearly improved: For the first time the patient slept without interruption and without the need for sleep-inducing medication. After 5 days with wIRA the patient could eat his first soft dumpling although drinking of fluids was still not possible. After 2½ weeks with wIRA the patient could eat his first minced schnitzel (escalope. Following the commencement of wIRA (with typically approximately 90–150 minutes irradiation with wIRA per day the patient had 8 months with good quality of life with only small amounts of liquid saliva and mucus and without the

  4. 近红外吸收滤光片的制备与性能研究%Preparation of near infrared absorption filter and its property

    Institute of Scientific and Technical Information of China (English)

    戴峰; 樊卫华; 吴金华; 王丽熙; 张其土

    2011-01-01

    将两种近红外吸收剂添加到丙烯酸树脂基体中再与PET薄膜复合,制备了可用于夜视兼容照明的双层复合型近红外吸收滤光片.研究了两种近红外吸收剂的吸收特性,以及近红外吸收剂添加量与滤光片吸收性能的关系,并确定了两种近红外吸收剂的用量.所制备的滤光片在660 ~930 nm波长范围内的光线平均透过率为0.10%,能有效吸收发光器件的干扰光,是一种性能良好的近红外吸收滤光片.另外,经过测试表明滤光片强度大、热稳定性较好,具有良好的应用性能.%Near infrared(NIR)absorption filters are prepared by NIR-dyes and optical plastics. These NIR absorption filters can be applied to light apparatus for night vision imaging system( NVIS) which is compatible with lighting. The optical performance of the filters is studied under different dye dosage. The results show the optical properties of the filters can be easily controlled by changing the amount of NIR-dyes. Besides, there is a good linear relationship between absorbance and NIR-dyes dosage. A NIR absorption filter with optimal dye dosage has been prepared. The filter shows strong absorbing ability in the region between 660nm and 930nm. Meanwhile, the filter has sufficient transmit-tance between 400 nm and 630 nm. The test result shows that the filter has good application performance.

  5. Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A.

    Science.gov (United States)

    Karygianni, L; Ruf, S; Follo, M; Hellwig, E; Bucher, M; Anderson, A C; Vach, K; Al-Ahmad, A

    2014-12-01

    Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS + wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 μg ml(-1) toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS + wIRA with an energy density of 200 mW cm(-2) for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB- and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS + wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.

  6. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  7. Improved method for the determination of nonpurgeable suspended organic carbon in natural water by silver filter filtration, wet chemical oxidation, and infrared spectrometry

    Science.gov (United States)

    Burkhardt, M.R.; Brenton, R.W.; Kammer, J.A.; Jha, V.K.; O'Mara-Lopez, P. G.; Woodworth, M.T.

    1999-01-01

    Precision and accuracy are reported for the first time for the analysis of nonpurgeable suspended organic carbon by silver membrane filtration followed by wet chemical oxidation. A water sample is pressure filtered through a 0.45-??m-pore-size, 47-mm-diameter silver membrane filter. The silver membrane filter then is cut into ribbons and placed in a flame-sealable glass ampule. The organic material trapped on the membrane filter strips is acidified, purged with oxygen to remove inorganic carbonates and volatile organic compounds, and oxidized to carbon dioxide (CO2) using phosphoric acid and potassium persulfate in the sealed glass ampule. The resulting CO2 is measured by a nondispersive infrared CO2 detector. The amount of CO2 is proportional to the concentration of chemically oxidizable nonpurgeable organic carbon in the environmental water sample. The quantitation and method detection limit for routine analysis is 0.2 mg/L. The average percent recovery in five representative matrices was 97 ?? 11%. The errors associated with sampling and sample preparation of nonpurgeable suspended organic carbon are also described.Precision and accuracy are reported for the first time for the analysis of nonpurgeable suspended organic carbon by silver membrane filtration followed by wet chemical oxidation. A water sample is pressure filtered through a 0.45-??m-pore-size, 47-mm-diameter silver membrane filter. The silver membrane filter then is cut into ribbons and placed in a flame-sealable glass ampule. The organic material trapped on the membrane filter strips is acidified, purged with oxygen to remove inorganic carbonates and volatile organic compounds, and oxidized to carbon dioxide (CO2) using phosphoric acid and potassium persulfate in the sealed glass ampule. The resulting CO2 is measured by a nondispersive infrared CO2 detector. The amount of CO2 is proportional to the concentration of chemically oxidizable nonpurgeable organic carbon in the environmental water sample

  8. 红外图像的自适应混合双边滤波算法%Adaptive hybrid bilateral filtering algorithm for infrared image

    Institute of Scientific and Technical Information of China (English)

    余博; 郭雷; 赵天云; 钱晓亮

    2012-01-01

    针对红外图像中的混合噪声,提出了一种自适应混合双边滤波算法.首先对双边滤波原理进行了分析,提出不能滤除强高斯噪声和脉冲噪声是由于双边滤波引入灰度域权值而带来的固有不足,因此根据双边滤波算法的特点设置了一种像素间的相似度,并以该相似度为基础将双边滤波不能滤除的强噪声点进行了标记,仅对红外图像中标记出的强噪声点进行中值滤波以减少图像模糊,对普通噪声点采用灰度方差自适应双边滤波以保留更多边缘特征.自适应混合双边滤波能够有效滤除红外图像中的高斯噪声、脉冲噪声以及由其组成的混合噪声,同时在滤波过程中并不降低双边滤波保留红外图像边缘特征的性能.仿真实验结果表明,与传统双边滤波、改进的双边滤波以及各项异性扩散-中值滤波算法相比,该算法无论是滤除红外图像的混合噪声还是保留边缘特征都较为优越.%In view of the mixed noise in the infrared image, the adaptive hybrid bilateral filtering was proposed. The principle of bilateral filter was analyzed. It was put forward that the shortage of bilateral filtering which couldn' t filter out strong Gauss noise and impulse noise was inherent. Therefore, the average similarity was defined for bilateral filtering. On the basis of the average similarity, noise points were marked with strong noise points which couldn't be filtered out by bilateral filtering and ordinary noise points which could be filtered out by bilateral filtering. To reduce image fuzzy, only the strong noise points were filtered by median filtering. To keep more edge character, ordinary noise points were filtered by adaptive bilateral filtering. Simulation results show that the hybrid bilateral filtering keeps more edge character, and filters out Gaussian noise and the mixed noise which consist of Gaussian noise and impulse noise effectively. The algorithm is superior to

  9. Analysis of Stierwalt out-of-band transmission scattering effect for dual infrared filters serially positioned at a focus

    Science.gov (United States)

    Kumer, J. B.; Sterrit, L. W.; Eisenhauer, D. L.

    1986-01-01

    Some remote sounding applications require utilization of interference filters with very high out-of-band rejection (OBR) performance. In this paper, the advantages to be gained in achieving high OBR by the use of two serially ganged interference filters mounted in a wedge configuration near a focus are discussed. Degradation of OBR due to scattering effects is examined, and a quantitative technique to estimate such effects in dual wedged filters mounted at a focus is presented. An approach to the design of filter elements to be used in the dual wedged configuration is given that accounts for scatter. An application of this design approach to the CLAES 10.81 micron filter is described.

  10. Infrared dim target detection based on anisotropic SUSAN filtering%各向异性SUSAN滤波红外弱小目标检测

    Institute of Scientific and Technical Information of China (English)

    景亮; 彭真明; 何艳敏; 蒲恬

    2013-01-01

    The SUSAN filtering operator can not self-adaptively modulate filter coefficients due to the use of an axisymmetric Gaussian filter.In order to solve this problem,this article presents an anisotropic SUSAN filter using an anisotropic Gaussian filter instead of a Gaussian filter in the SUSAN filtering operator.The variances of long axis and short axis are determined by the variance and the pixel neighborhood smoothness of the partial image.The long axis direction is determined by the gradient direction of the point.The SUSAN filter threshold is determined by the first order norm of the difference of the gray value and the mean value.For the infrared dim target detection,experimental results show that the anisotropic SUSAN filter could preserve the image edge information,the signal-to-noise ratio gain and signal-to-clutter ratio gain greatly improved in the residual image,the size of the target got a better retention,and the false alarm decreased.%为了解决SUSAN滤波算子不能自适应调整滤波系数的问题,采用Geusebroek提出的各向异性高斯滤波器替代SUSAN滤波算子中的高斯滤波部分.由局部图像的方差和像素的邻域平滑度决定长短轴的方差,由该点的梯度方向决定滤波器的长轴方向,由局部图像的灰度值与均值差的一阶范数确定SUSAN滤波器的阈值,从而构造出各向异性SUSAN滤波器.将其用于红外弱小目标检测中,实验结果表明:各向异性SUSAN滤波器能够很好地保留图像中的边缘信息,使残差图像中弱小目标的信噪比增益和信杂比增益极大地提高,目标大小得到较好的保留,虚警率下降.

  11. Calculation and Analysis on Electro-magnetic Field of the Asynchronous Traction Motor for Freight Locomotive%货运机车异步牵引电机电磁场计算与分析

    Institute of Scientific and Technical Information of China (English)

    阮鸿芳; 于海涛

    2015-01-01

    Taking the AC asynchronous traction mo-tor of the HXD1C high-power locomotive as example, the 2D mathematic model of the electro-magnetic field was established and its solved region was determined either. The finite element method was applied to calculate the electro-magnetic parameters of the traction motor while the calculated result was compared with the actually-test data, and then, came the beneficial conclusion.%以大功率交流传动H X D1C机车用异步牵引电机为例,建立电机二维电磁场数学模型,并确定其求解域.利用有限元方法,计算牵引电机电磁参数,并将计算结果与实测数据进行对比,得出一些有益的结论.

  12. Transient Two-Phase Flow in Slide-Gate Nozzle and Mold of Continuous Steel Slab Casting with and without Double-Ruler Electro-Magnetic Braking

    Science.gov (United States)

    Cho, Seong-Mook; Thomas, Brian G.; Kim, Seon-Hyo

    2016-10-01

    Transient mold flow could produce undesirable surface instabilities and slag entrainments, leading to the formation of defects during continuous slab casting of steel. In this work, two Large Eddy Simulations coupled with Discrete Phase Model are run, with and without MagnetoHydroDynamic model, to gain new insights into the surface variations of molten steel-argon gas flow with anisotropic turbulence in the slide-gate nozzle and the mold, with and without double-ruler Electro-Magnetic Braking (EMBr). The model calculations are validated with plant measurements, and applied to investigate the flow variations related to the slide gate on nozzle swirl, jet wobbling, and surface flow variations by quantifying the variations of velocity, horizontal angle, and vertical angle of the transient flow. Transient flow in the slide-gate nozzle bottom is almost always swirling, alternating chaotically between clockwise and counter-clockwise rotation. The clockwise swirl, caused by stronger flow down the same side of the nozzle as the open area near the Outside Radius side of the slide-gate middle plate, produces faster jet flow and higher velocity flow across the top surface of the mold. Counter-clockwise swirl produces slower jet and surface flow, but with more variations. The double-ruler EMBr decreases the asymmetry and duration of velocity variations during nozzle swirl flipping, resulting in less flow variations in the jet and across the surface in the mold.

  13. Avoidance of Tearing Mode Locking and Disruption with Electro-Magnetic Torque Introduced by Feedback-based Mode Rotation Control in DIII-D and RFX-mod

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, M. [PPPL; Zanca, P. [Euratom-ENEA; Strait, E. J. [General Atomics

    2014-09-01

    Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a very promising scheme to avoid such disruptions by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque to the modes is created by a toroidal phase shift between the externally-applied field and the excited TM fields, compensating for the mode momentum loss due to the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two vastly different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high βN plasmas in a non-circular divertor tokamak. In RFX-mod, the plasma was ohmically-heated plasma with ultralow safety factor in a circular limiter discharge of active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited to this purpose.

  14. ``Pheudo-cyclotron'' radiation and transport of non-relativistic particles in inhomogeneous sub-Larmor-scale electro-magnetic fields

    Science.gov (United States)

    Keenan, Brett; Ford, Alex; Medvedev, Mikhail

    2014-10-01

    Plasma turbulence in some astrophysical objects (e.g., weakly magnetized collisionless shocks in GRBs and SN) has small-scale electro-magnetic field fluctuations. We study spectral characteristics of radiation produced by particles moving in such turbulence and relate it to transport properties (diffusion) of these particles. It was shown earlier that relativistic particles produce jitter radiation, which spectral characteristics are markedly different from synchrotron radiation. Here we study radiation produced by non-relativistic particles. Unlike radiation in homogeneous field, which spectrum consists of a single cyclotron harmonic, radiation in the sub-Larmor-scale turbulence reflects statistical properties of the underlying magnetic field. We present both analytical estimates and results of ab initio numerical simulations. We also show that particle propagation in such turbulence is diffusive and evaluate the diffusion coefficient. We demonstrate that the diffusion coefficient correlates with some spectral parameters. These results can be very valuable for remote diagnostics of laboratory and astrophysical plasmas. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.

  15. Design and implementation of film coating for tunable liquid crystal Fabry-Perot filter working in mid-infrared spectral region

    Science.gov (United States)

    Zhang, Huaidong; Fu, Anbang; Zhang, Xinyu; Sang, Hongshi; Xie, Changsheng

    2013-10-01

    In this paper, we design and implementation anti-reflection and high reflection film for tunable LC-FP filter working in typical medium wave infrared (MWIR) spectral region. As to reflection mirror, we complete it by depositing gold film on the silicon substrate. By using the analytical method of dividing amplitude multiple beam interference to simulate the reflectance, the reflectivity result of the gold film is around 98% at the average in the MWIR spectral region. When take the absorption of the gold film into consideration, the gold film should be thin under the condition that it is conductive well. The anti-reflection film is introduced to reduce the reflection of the other side of the wafer. In anti-reflection structure, we simulate the reflection of the films with the algorithm of the equivalent membrane and fulfill our design with the technology of vapor deposition. Finally, we test the total transmittance of the wafer deposited gold films and anti-reflection films, which is about 0.2% of single chip. By making use of the wafer designed by us, we fabricate the LC-FP filter by placing two wafers side by side with the anti-reflection structure face to the direction of wavelength incident. Simultaneously, the LC layer with fixed thickness is sealed between the two high reflection mirrors formed by gold film. Compared with other method to fabricate mid-infrared FP filter, deposition of reflection and anti-reflection films on wafer have the advantage of low cost, simple technology.

  16. IIR Filter Modeling Using an Algorithm Inspired on Electromagnetism

    Directory of Open Access Journals (Sweden)

    Cuevas-Jiménez E.

    2013-01-01

    Full Text Available Infinite-impulse-response (IIR filtering provides a powerful approach for solving a variety of problems. However, its design represents a very complicated task, since the error surface of IIR filters is generally multimodal, global optimization techniques are required in order to avoid local minima. In this paper, a new method based on the Electromagnetism-Like Optimization Algorithm (EMO is proposed for IIR filter modeling. EMO originates from the electro-magnetism theory of physics by assuming potential solutions as electrically charged particles which spread around the solution space. The charge of each particle depends on its objective function value. This algorithm employs a collective attraction-repulsion mechanism to move the particles towards optimality. The experimental results confirm the high performance of the proposed method in solving various benchmark identification problems.

  17. Upregulated expression of La ribonucleoprotein domain family member 6 and collagen type I gene following water-filtered broad-spectrum near-infrared irradiation in a 3-dimensional human epidermal tissue culture model as revealed by microarray analysis.

    Science.gov (United States)

    Tanaka, Yohei; Nakayama, Jun

    2017-02-27

    Water-filtered broad-spectrum near-infrared irradiation can induce various biological effects, as our previous clinical, histological, and biochemical investigations have shown. However, few studies that examined the changes thus induced in gene expression. The aim was to investigate the changes in gene expression in a 3-dimensional reconstructed epidermal tissue culture exposed to water-filtered broad-spectrum near-infrared irradiation. DNA microarray and quantitative real-time polymerase chain reaction (PCR) analysis was used to assess gene expression levels in a 3-dimensional reconstructed epidermal model composed of normal human epidermal cells exposed to water-filtered broad-spectrum near-infrared irradiation. The water filter allowed 1000-1800 nm wavelengths and excluded 1400-1500 nm wavelengths, and cells were exposed to 5 or 10 rounds of near-infrared irradiation at 10 J/cm(2) . A DNA microarray with over 50 000 different probes showed 18 genes that were upregulated or downregulated by at least twofold after irradiation. Quantitative real-time PCR revealed that, relative to control cells, the gene encoding La ribonucleoprotein domain family member 6 (LARP6), which regulates collagen expression, was significantly and dose-dependently upregulated (P < 0.05) by water-filtered broad-spectrum near-infrared exposure. Gene encoding transcripts of collagen type I were significantly upregulated compared with controls (P < 0.05). This study demonstrates the ability of water-filtered broad-spectrum near-infrared irradiation to stimulate the production of type I collagen. © 2017 The Australasian College of Dermatologists.

  18. 近红外吸收PC滤光片的制备与性能研究%PREPARATION AND PROPERTIES OF POLYCARBONATE NEAR-INFRARED ABSORPTION FILTER

    Institute of Scientific and Technical Information of China (English)

    戴峰; 徐亮; 王丽熙; 张其土

    2012-01-01

    A new near-infrared ( NIR) absorption filter with good optical and mechanical properties was prepared by injection molding method. It was made by NIR-dyes and polycarbonate. This NIR absorption filter can be applied on light apparatus for night vision imaging system ( NVIS) compatible lighting. The optical performance of the filter was studied. The filter material offers sufficient transmittance in the visible spectrum along with excellent extinction in the NIR region. The results also showed there was a good linear relationship between its absorbance and NIR-dye dosage. This means that the optical property of the filter can be easily controlled by changing the amount of NIR-dyes. A NIR absorption filter with optimal dye dosage was prepared. The filter has a transmittance not higher than 0. 15% in the NIR region in the wavelength range of 660 ~930 nm; a 16% value of transmittance in the wavelength range of 400 - 630 nm. The filter is excellent in environmental stability that after being left to stand in the air atmosphere at temperature of 851 and exposed to light condition at 1120 W/m2 for 200 h,the filter can maintain its spectral property in the said range. Its bending strength ig 107 MPa,shock strength is 54. 4 kJ/m2. Therefore the filter can stand strong mechanical impact in the actual application environment.%使用染料-高聚物混合(dye-in-polymer)的方法将近红外吸收染料作为功能添加剂分散在聚碳酸酯(PC)中,采用注塑成型的方法制备了用于夜视兼容照明的近红外吸收滤光片.研究了近红外吸收剂在PC材料中的吸收行为,确定了近红外吸收剂的添加量,最终制备的近红外吸收滤光片在660 ~930 nm波长范围内有良好的吸收能力,在此波段范围内的光线透过率为0.15%,同时在450~630 nm波长范围内保持了较好的可见光透过性.按照标准测试手段对样品的耐热老化性能,耐光老化性能和力学性能进行了测试.结果表明,制备的近

  19. Technical Note: Improved total atmospheric water vapour amount determination from near-infrared filter measurements with sun photometers

    Directory of Open Access Journals (Sweden)

    F. Mavromatakis

    2007-09-01

    Full Text Available In this work we explore the effect of the contribution of the solar spectrum to the recorded signal in wavelengths outside the typical 940-nm filter's bandwidth. We employ gaussian-shaped filters as well as actual filter transmission curves, mainly AERONET data, to study the implications imposed by the non-zero out-of-band contribution to the coefficients used to derive precipitable water from the measured water vapour band transmittance. Published parameterized transmittance functions are applied to the data to determine the filter coefficients. We also introduce an improved, three-parameter, fitting function that can describe the theoretical data accurately, with significantly less residual effects than with the existing functions. The moderate-resolution SMARTS radiative transfer code is used to predict the incident spectrum outside the filter bandpass for different atmospheres, solar geometries and aerosol optical depths. The high-resolution LBLRTM radiative transfer code is used to calculate the water vapour transmittance in the 940-nm band. The absolute level of the out-of-band transmittance has been chosen to range from 10−6 to 10−4, and typical response curves of commercially available silicon photodiodes are included into the calculations.

    It is shown that if the out-of-band transmittance effect is neglected, as is generally the case, then the derived columnar water vapour is mainly underestimated by a few percents. The actual error depends on the specific out-of-band transmittance, optical air mass of observation and water vapour amount. Further investigations will use experimental data from field campaigns to validate these findings.

  20. 电磁波层析成像反演射线路径的探讨%Discussion on Inversion Ray Path of Electro-magnetic Computerized Tomography

    Institute of Scientific and Technical Information of China (English)

    刘海涛; 董艳平; 彭军; 董亮

    2015-01-01

    In computerized tomography test,the position of recording point after data inversion is determined by the position of transmitting point and receiving point between the two probes.In order to find out the position of record-ing points,we carried out experiment on electro-magnetic probe shielding by steel pipes.The experiment show that the energy concentration area between the two probes is parallelogram,hence it is more reasonable to inverse paral-lelogram area with four electro-magnetic wave rays rather than one ray path.On this basis,we propose to obtain the four single inversion result from each ray path and average them as the final result.This method was applied to the data processing of karst exploration for Wuhan underground.Through comparison of inversion result,this method is verified to be more precise than single-path inversion in the environment of the same inversion software.%在电磁波 CT 测试中,发射、接收探头间的电磁波射线发射点、接收点位置决定反演后成果数据记录点的位置。为了确定电磁波仪发射、接收探头记录点位置,对探头分别进行钢管屏蔽实验,实验表明电磁波仪工作时电磁波能量主要集中在两探头的馈电点及天线末端间近似于平行四边形的区域内,不宜直接地简化为一条直线,将平行四边形区域简化为4条线段进行电磁波层析成像反演计算更符合实际情况。在此基础上,提出对电磁波 CT 数据采取4条射线路径单独反演后,再将4个结果按综合平均的方法进行处理。将此种处理方法应用于武汉地铁岩溶勘察数据处理中,并与目前基于1条射线的反演处理方法进行对比、验证。对比剖面反演数据结果表明,在采用同一反演软件条件下4条射线路径综合反演法精度优于1条射线反演法。

  1. Avoidance of tearing mode locking with electro-magnetic torque introduced by feedback-based mode rotation control in DIII-D and RFX-mod

    Science.gov (United States)

    Okabayashi, M.; Zanca, P.; Strait, E. J.; Garofalo, A. M.; Hanson, J. M.; In, Y.; La Haye, R. J.; Marrelli, L.; Martin, P.; Paccagnella, R.; Paz-Soldan, C.; Piovesan, P.; Piron, C.; Piron, L.; Shiraki, D.; Volpe, F. A.; DIII-D, The; RFX-mod Teams

    2017-01-01

    Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a promising scheme to avoid mode locking by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque is delivered to the modes by a toroidal phase shift between the externally applied field and the excited TM fields, compensating for the mode momentum loss through the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two widely different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high β N in a non-circular divertor tokamak. Here β N is defined as β N  =  β/(I p /aB t) (%Tm/MA), where β, I p, a, B t are the total stored plasma pressure normalized by the magnetic pressure, plasma current, plasma minor radius and toroidal magnetic field at the plasma center, respectively. The RFX-mod plasma was ohmically-heated with ultra-low safety factor in a circular limiter discharge with active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as the International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited for this purpose.

  2. Cryogenic infrared multilayer filters: the origin of low-temperature shift of the pass-band edge

    Science.gov (United States)

    Belyaeva, Alla I.

    1999-11-01

    The design, manufacture and optimum performance of a cut-on IR for the 8-14 micrometers is discussed. The filter is composed of PbTe/ZnS symmetrical stacks deposited on tow sides of a ZnSe(ZnS) substrate. The refractive index of PbTe was found to 5.6 and that of ZnS 2.15. In order to obtain the required pass/stop band profile the principal filter was composed of ten basic periods. The transparent in the mean IR-range multilayer coatings are stable of thermal cycling from 300 up to 8 K with steady optical characteristics in this temperature range. The average transmittance of filters was 75 percent in the desired spectral regions and was constant in the temperature interval 300-8 K. The effect of cooling on the position of the pass band edge of the interference multilayer thin-film coating is experimentally revealed. A model is suggested which explains the origin of low- temperature shift of the pass-band edge within the scope of variation in the optical thickness of a layer with the high refractive index. The result of the carried out numerical analysis are in well agreement with the experimental data and may be used for cryocorrection of the interference IR multilayer thin-film.

  3. Effects of Temperature and Water-Filtered Infrared-A Alone or in Combination on Healthy and Glyoxal-Stressed Fibroblast Cultures

    Directory of Open Access Journals (Sweden)

    Lilla Knels

    2012-01-01

    Full Text Available Water-filtered infrared-A (wIRA radiation has been described as supportive for tissue regeneration. We sought to investigate in detail the wIRA effect at different temperatures in 3T3 fibroblasts that were treated with glyoxal to induce formation of advanced glycation end products (AGEs. Nonirradiated and nonglyoxal-treated cells served as controls. Experiments were carried out over a range of 37∘–45∘C with exact temperature monitoring to distinguish between temperature and wIRA effects. Metabolic activity was assessed by resazurin assay. Mitochondrial membrane potential was assessed by JC-1 vital staining. Apoptotic changes were determined by vital staining with annexin V and YO-PRO-1 and determination of subG1 DNA content. Temperature had a dominant effect overriding effects exerted by wIRA or glyoxal treatment. The number of apoptotic cells was significantly higher at 45∘C, while the percentage of healthy cells was significantly lower at 45∘C. WIRA irradiation itself or in combination with glyoxal treatment exerted no damaging effects on the fibroblasts at physiological (37∘–40∘C or higher (42∘–45∘C temperatures compared to untreated controls. Temperatures of 45∘C, which can occur during inappropriate application of infrared irradiation, damage cells even in the absence of wIRA or glyoxal application.

  4. ALMA Band 1 Optics (35-50 GHz): Tolerance Analysis, Effect of Cryostat Infrared Filters and Cold Beam Measurements

    Science.gov (United States)

    Gonzalez, A.; Tapia, V.; Finger, R.; Huang, C.-D.; Asayama, S.; Huang, Y.-D.

    2017-10-01

    The Atacama Large Millimeter/Sub-millimeter Array (ALMA) is currently the largest (sub-)mm wave telescope in the world and will be used for astronomical observations in all atmospheric windows from 35 to 950 GHz when completed. The ALMA band 1 (35-50 GHz) receiver will be used for the longest wavelength observations with ALMA. Because of the longer wavelength, the size of optics and waveguide components will be larger than for other ALMA bands. In addition, all components will be placed inside the ALMA cryostat in each antenna, which will impose severe mechanical constraints on the size and position of receiver optics components. Due to these constraints, the designs of the corrugated feed horn and lens optics are highly optimized to comply with the stringent ALMA optical requirements. In this paper, we perform several tolerance analyses to check the impact of fabrication errors in such an optimized design. Secondly, we analyze the effects of operating this optics inside the ALMA cryostat, in particular the effects of having the cryostat IR filters placed next to the band 1 feed horn aperture, with the consequent near-field effects. Finally, we report on beam measurements performed on the first three ALMA band 1 receivers inside test cryostats, which satisfy ALMA specifications. In these measurements, we can clearly observe the effects of fabrication tolerances and IR filter effects on prototype receiver performance.

  5. Digital filter method of oversampling Fourier transform infrared spectrometer%过采样型傅里叶红外光谱仪的数字滤波方法

    Institute of Scientific and Technical Information of China (English)

    任利兵; 尉昊赟; 李岩

    2012-01-01

    The frequency response range of infrared detector in Fourier transform infrared spectrometer extends from dozens of Hz to some MHz generally. Because of wide frequency response, the measured signal will be easily blurred by lower and higher frequency noise from ambient. Noise can deform the real infrared interference signal. Compared with traditional Fourier transform infrared spectrometer, the oversampling one seems like to put the equal-spacing sampling procedure into computer. Therefore, it will be possible to lay a digital filter after the oversampling infrared interference signal. Based on evaluation of effective frequency response range of infrared interference signal, the design method of a Buttworth bandpass digital filter was illustrated. With this designed filter, the noise of oversampling infrared interference signal could be filtered. The experimental results show that the designed filter can effectively filter higher and lower noise to keep real spectral signal. Additionally, the digital filter is easier and more flexible to design than analog one.%傅里叶红外光谱仪使用的红外探测器频率响应范围通常为几十Hz到数MHz,这使得探测器直接接收的干涉信号中很容易混入环境噪声,引起真实干涉信号的畸变.过采样型傅里叶红外光谱仪等同于将传统光谱仪的等光程间隔采样过程“搬移”到计算机内,因此,理论上允许使用数字滤波器代替模拟滤波器对红外干涉信号降噪.在分析过采样型傅里叶红外光谱仪红外干涉信号有效频率范围的基础上,详述了适用于过采样型傅里叶红外光谱仪的巴特沃斯数字带通滤波器的设计方法,并应用设计的滤波器对过采样的红外干涉信号进行了降噪研究.结果表明:数字滤波的方法能有效去除红外干涉信号中的高、低频噪声,保留真实的光谱信号,在使用上也比模拟滤波更加灵活、便捷.

  6. 3D coaxial out-of-plane metallic antennas for filtering and multi-spectral imaging in the infrared range.

    Science.gov (United States)

    Jacassi, Andrea; Bozzola, Angelo; Zilio, Pierfrancesco; Tantussi, Francesco; De Angelis, Francesco

    2016-06-27

    We fabricated and investigated a new configuration of 3D coaxial metallic antennas working in the infrared which combines the strong lateral light scattering of vertical plasmonic structures with the selective spectral transmission of 2D arrays of coaxial apertures. The coaxial structures are fabricated with a top-down method based on a template of hollow 3D antennas. Each antenna has a multilayer radial structure consisting of dielectric and metallic materials not achievable in a 2D configuration. A planar metallic layer is inserted normally to the antennas. The outer dielectric shell of the antenna defines a nanometric gap between the horizontal plane and the vertical walls. Thanks to this aperture, light can tunnel to the other side of the plane, and be transmitted to the far field in a set of resonances. These are investigated with finite-elements electromagnetic calculations and with Fourier-transform infrared spectroscopy measurements. The spectral position of the resonances can be tuned by changing the lattice period and/or the antenna length. Thanks to the strong scattering provided by the 3D geometry, the transmission peaks possess a high signal-to-noise ratio even when the illuminated area is less than 2 × 2 times the operation wavelength. This opens new possibilities for multispectral imaging in the IR with wavelength-scale spatial resolution.

  7. Enhancement algorithm for infrared images based on Kalman filter%基于卡尔曼滤波的红外图像增强算法

    Institute of Scientific and Technical Information of China (English)

    刘涛; 赵巨峰; 徐之海; 冯华君; 陈慧芳

    2012-01-01

    针对红外图像中的非均匀性噪声的去除问题,提出基于卡尔曼滤波的红外图像去噪及增强算法.在Bayesian-MAP框架下分析卡尔曼滤波器对去噪问题的适用性.由于成像电路内部温度上升和参数的细微变化,每个像元的固定模式噪声(FPN)在帧间缓慢变化.基于此点,建立暗帧的噪声模型.将卡尔曼滤波器作用于红外暗帧序列,估计出暗帧中每个像元的FPN水平.引入噪声影响因子(NIF)来评估FPN噪声对像元输出信号的影响.根据NIF自适应地选取每个像元的FPN噪声权重.实际带噪图像减去加权FPN噪声,即得到增强图像.将该算法应用于实拍红外图像,用平均灰度梯度(GMG)评估算法的性能.在目标区域,GMG下降了5.1%,说明算法在去噪的同时很好地保留了目标的边缘.而在平滑区域,GMG下降了85.5%.结果表明,该算法在去除非均匀性噪声,提高图像的对比度方面,取得较好的效果.%To remove the non-uniformity noise in the infrared image, the denoise and enhancement algorithm based on Kalman filter is proposed. In the framework of Bayesian-MAP inference, the feasibility of Kalman filter was discussed. Due to the inner temperature increment and the circuit parameters' minor changes of the imaging system, each pixel's fixed pattern noise (FPN) varies slowly and non-uniformly between frames. Based on this view, the dark frame was modeled. The level of the FPN was estimated by Kalman filter acted on sequential dark frames. The noise influence factor (NIF) was introduced to evaluate the influence of the FPN to the pixel's output signal. And then, the reasonable weight of each pixel's FPN was determined adaptively by means of NIF. The non-uniformity of the infrared image can be corrected after weighted subtraction FPN from the real noisy image data on pixels one by one. The algorithm was applied in real infrared images and gray mean grads (GMG) was used to evaluate its performance. In

  8. Sampling and quantitative analysis of clean B. subtilis spores at sub-monolayer coverage by reflectance fourier transform infrared microscopy using gold-coated filter substrates.

    Science.gov (United States)

    Brooke, Heather; Perkins, David L; Setlow, Barbara; Setlow, Peter; Bronk, Burt V; Myrick, Michael L

    2008-08-01

    A study was conducted to determine the concentration dependency of the mid-infrared (MIR) absorbance of bacterial spores. A range of concentrations of Bacillus subtilis endospores filtered across gold-coated filter membranes were analyzed by Fourier transform infrared (FT-IR) reflectance microscopy. Calibration curves were derived from the peak absorbances associated with Amide A, Amide I, and Amide II vibrational frequencies by automatic baseline fitting to remove most of the scattering contribution. Linear relationships (R2 >or= 0.99) were observed between the concentrations of spores and the baseline-corrected peak absorbance for each frequency studied. Detection limits for our sampled area of 100 x100 microm2 were determined to be 79, 39, and 184 spores (or 7.92 x 10(5), 3.92 x 10(5), and 1.84 x 10(6) spores/cm2) for the Amide A, Amide I, and Amide II peaks, respectively. Absorbance increased linearly above the scattering baseline with particle surface concentration up to 0.9 monolayer (ML) coverage, with the monolayer density calculated to be approximately 1.17 x 10(8) spores/cm2. Scattering as a function of surface concentration, as estimated from extinction values at wavelengths exhibiting low absorbance, becomes nonlinear at a much lower surface concentration. The apparent scattering cross-section per spore decreased monotonically as concentrations increased toward 1.2 ML, while the absolute scattering decreased between 0.9 ML and 1.2 ML coverage. Calculations suggest that transverse spatial coherence effects are the origin of this nonlinearity, while the onset of nonlinearity in the baseline-corrected absorption is probably due to multiple scattering effects, which appear at a high surface concentration. Absorption cross-sections at peaks of the three bands were measured to be (2.15 +/- 0.05) x 10(-9), (1.48 +/- 0.03) x 10(-9), and (0.805 +/- 0.023) x 10(-9) cm2, respectively. These values are smaller by a factor of 2-4 than expected from the literature

  9. Direct-on-Filter α-Quartz Estimation in Respirable Coal Mine Dust Using Transmission Fourier Transform Infrared Spectrometry and Partial Least Squares Regression.

    Science.gov (United States)

    Miller, Arthur L; Weakley, Andrew Todd; Griffiths, Peter R; Cauda, Emanuele G; Bayman, Sean

    2016-09-19

    In order to help reduce silicosis in miners, the National Institute for Occupational Health and Safety (NIOSH) is developing field-portable methods for measuring airborne respirable crystalline silica (RCS), specifically the polymorph α-quartz, in mine dusts. In this study we demonstrate the feasibility of end-of-shift measurement of α-quartz using a direct-on-filter (DoF) method to analyze coal mine dust samples deposited onto polyvinyl chloride filters. The DoF method is potentially amenable for on-site analyses, but deviates from the current regulatory determination of RCS for coal mines by eliminating two sample preparation steps: ashing the sampling filter and redepositing the ash prior to quantification by Fourier transform infrared (FT-IR) spectrometry. In this study, the FT-IR spectra of 66 coal dust samples from active mines were used, and the RCS was quantified by using: (1) an ordinary least squares (OLS) calibration approach that utilizes standard silica material as done in the Mine Safety and Health Administration's P7 method; and (2) a partial least squares (PLS) regression approach. Both were capable of accounting for kaolinite, which can confound the IR analysis of silica. The OLS method utilized analytical standards for silica calibration and kaolin correction, resulting in a good linear correlation with P7 results and minimal bias but with the accuracy limited by the presence of kaolinite. The PLS approach also produced predictions well-correlated to the P7 method, as well as better accuracy in RCS prediction, and no bias due to variable kaolinite mass. Besides decreased sensitivity to mineral or substrate confounders, PLS has the advantage that the analyst is not required to correct for the presence of kaolinite or background interferences related to the substrate, making the method potentially viable for automated RCS prediction in the field. This study demonstrated the efficacy of FT-IR transmission spectrometry for silica determination in

  10. Kinetics of physiological skin flora in a suction blister wound model on healthy subjects after treatment with water-filtered infrared-A radiation.

    Science.gov (United States)

    Daeschlein, G; Alborova, J; Patzelt, A; Kramer, A; Lademann, J

    2012-01-01

    The effect of water-filtered infrared-A radiation (wIRA) on normal skin flora was investigated by generating experimental wounds on the forearms of volunteers utilizing the suction blister technique. Over 7 days, recolonization was monitored parallel to wound healing. Four groups of treatment were compared: no therapy (A), dexpanthenol cream once daily (B), 20 min wIRA irradiation at 30 cm distance (C), and wIRA irradiation for 30 min once daily together with dexpanthenol cream once daily (D). All treatments strongly inhibited the recolonization of the wounds. Whereas dexpanthenol completely suppressed recolonization over the test period, recolonization after wIRA without (C) and in combination with dexpanthenol (D) was suppressed, but started on day 5 with considerably higher amounts after the combination treatment (D). Whereas the consequence without treatment (A) was an increasing amount of physiological skin flora including coagulase-negative staphylococci, all treatments (B-D) led to a reduction in physiological skin flora, including coagulase-negative staphylococci. In healthy volunteers, wIRA alone and in combination with dexpanthenol strongly inhibited bacterial recolonization with physiological skin flora after artificial wound setting using a suction-blister wound model. This could support the beneficial effects of wIRA in the promotion of wound healing. Copyright © 2011 S. Karger AG, Basel.

  11. Effects of water-filtered infrared-A and of heat on cell death, inflammation, antioxidative potential and of free radical formation in viable skin--first results.

    Science.gov (United States)

    Piazena, Helmut; Pittermann, Wolfgang; Müller, Werner; Jung, Katinka; Kelleher, Debra K; Herrling, Thomas; Meffert, Peter; Uebelhack, Ralf; Kietzmann, Manfred

    2014-09-05

    The effects of water-filtered infrared-A (wIRA) and of convective heat on viability, inflammation, inducible free radicals and antioxidative power were investigated in natural and viable skin using the ex vivo Bovine Udder System (BUS) model. Therefore, skin samples from differently treated parts of the udder of a healthy cow were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, by prostaglandin E2 (PGE2) measurement and by electron spin resonance (ESR) spectroscopy. Neither cell viability, the inflammation status, the radical status or the antioxidative defence systems of the skin were significantly affected by wIRA applied within 30 min by using an irradiance of 1900 W m(-2) which is of relevance for clinical use, but which exceeded the maximum solar IR-A irradiance at the Earth's surface more than 5 times and which resulted in a skin surface temperature of about 45 °C without cooling and of about 37 °C with convective cooling by air ventilation. No significant effects on viability and on inflammation were detected when convective heat was applied alone under equivalent conditions in terms of the resulting skin surface temperatures and exposure time. As compared with untreated skin, free radical formation was almost doubled, whereas the antioxidative power was reduced to about 50% after convective heating to about 45 °C.

  12. An ensemble Kalman filter dual assimilation of thermal infrared and microwave satellite observations of soil moisture into the Noah land surface model

    Science.gov (United States)

    Hain, Christopher R.; Crow, Wade T.; Anderson, Martha C.; Mecikalski, John R.

    2012-11-01

    Studies that have assimilated remotely sensed soil moisture (SM) into land surface models (LSMs) have generally focused on retrievals from microwave (MW) sensors. However, retrievals from thermal infrared (TIR) sensors have also been shown to add unique information, especially where MW sensors are not able to provide accurate retrievals (due to, e.g., dense vegetation). In this study, we examine the assimilation of a TIR product based on surface evaporative flux estimates from the Atmosphere Land Exchange Inverse (ALEXI) model and the MW-based VU Amsterdam NASA surface SM product generated with the Land Parameter Retrieval Model (LPRM). A set of data assimilation experiments using an ensemble Kalman filter are performed over the contiguous United States to assess the impact of assimilating ALEXI and LPRM SM retrievals in isolation and together in a dual-assimilation case. The relative skill of each assimilation case is assessed through a data denial approach where a LSM is forced with an inferior precipitation data set. The ability of each assimilation case to correct for precipitation errors is quantified by comparing with a simulation forced with a higher-quality precipitation data set. All three assimilation cases (ALEXI, LPRM, and Dual assimilation) show relative improvements versus the open loop (i.e., reduced RMSD) for surface and root zone SM. In the surface zone, the dual assimilation case provides the largest improvements, followed by the LPRM case. However, the ALEXI case performs best in the root zone. Results from the data denial experiment are supported by comparisons between assimilation results and ground-based SM observations from the Soil Climate Analysis Network.

  13. Antimicrobial Photoinactivation Using Visible Light Plus Water-Filtered Infrared-A (VIS + wIRA) Alters In Situ Oral Biofilms.

    Science.gov (United States)

    Al-Ahmad, A; Bucher, M; Anderson, A C; Tennert, C; Hellwig, E; Wittmer, A; Vach, K; Karygianni, L

    2015-01-01

    Recently, growing attention has been paid to antimicrobial photodynamic therapy (aPDT) in dentistry. Changing the microbial composition of initial and mature oral biofilm by aPDT using visible light plus water-filtered infrared-A wavelengths (VIS + wIRA) has not yet been investigated. Moreover, most aPDT studies have been conducted on planktonic bacterial cultures. Therefore, in the present clinical study we cultivated initial and mature oral biofilms in six healthy volunteers for 2 hours or 3 days, respectively. The biofilms were treated with aPDT using VIS+wIRA (200 mW cm(-2)), toluidine blue (TB) and chlorine e6 (Ce6) for 5 minutes. Chlorhexidine treated biofilm samples served as positive controls, while untreated biofilms served as negative controls. After aPDT treatment the colony forming units (CFU) of the biofilm samples were quantified, and the surviving bacteria were isolated in pure cultures and identified using MALDI-TOF, biochemical tests and 16S rDNA-sequencing. aPDT killed more than 99.9% of the initial viable bacterial count and 95% of the mature oral biofilm in situ, independent of the photosensitizer. The number of surviving bacterial species was highly reduced to 6 (TB) and 4 (Ce6) in the treated initial oral biofilm compared to the 20 different species of the untreated biofilm. The proportions of surviving bacterial species were also changed after TB- and Ce6-mediated aPDT of the mature oral biofilm, resulting in a shift in the microbial composition of the treated biofilm compared to that of the control biofilm. In conclusion, aPDT using VIS + wIRA showed a remarkable potential to eradicate both initial and mature oral biofilms, and also to markedly alter the remaining biofilm. This encourages the clinical use of aPDT with VIS + wIRA for the treatment of periimplantitis and periodontitis.

  14. Influence of water-filtered infrared-A (wIRA on reduction of local fat and body weight by physical exercise

    Directory of Open Access Journals (Sweden)

    Schmitz, Gerd

    2006-07-01

    Full Text Available Aim of the study: Investigation, whether water-filtered infrared-A (wIRA irradiation during moderate bicycle ergometer endurance exercise has effects especially on local fat reduction and on weight reduction beyond the effects of ergometer exercise alone. Methods: Randomised controlled study with 40 obese females (BMI 30-40 (median: 34.5, body weight 76-125 (median: 94.9 kg, age 20-40 (median: 35.5 years, isocaloric nutrition, 20 in the wIRA group and 20 in the control group. In both groups each participant performed 3 times per week over 4 weeks for 45 minutes bicycle ergometer endurance exercise with a constant load according to a lactate level of 2 mmol/l (aerobic endurance load, as determined before the intervention period. In the wIRA group in addition large parts of the body (including waist, hip, and thighs were irradiated during all ergometries of the intervention period with visible light and a predominant part of water-filtered infrared-A (wIRA, using the irradiation unit “Hydrosun® 6000” with 10 wIRA radiators (Hydrosun® Medizintechnik, Müllheim, Germany, radiator type 500, 4 mm water cuvette, yellow filter, water-filtered spectrum 500-1400 nm around a speed independent bicycle ergometer. Main variable of interest: change of “the sum of circumferences of waist, hip, and both thighs of each patient” over the intervention period (4 weeks. Additional variables of interest: body weight, body mass index BMI, body fat percentage, fat mass, fat-free mass, water mass (analysis of body composition by tetrapolar bioimpedance analysis, assessment of an arteriosclerotic risk profile by blood investigation of variables of lipid metabolism (cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL, apolipoprotein A1, apolipoprotein B, clinical chemistry (fasting glucose, alanin-aminotransferase ALT (= glutamyl pyruvic transaminase GPT, gamma-glutamyl-transferase GGT, creatinine, albumin, endocrinology

  15. SW-MW infrared spectrometer for lunar mission

    Science.gov (United States)

    Banerjee, Arup; Biswas, Amiya; Joshi, Shaunak; Kumar, Ankush; Rehman, Sami; Sharma, Satish; Somani, Sandip; Bhati, Sunil; Karelia, Jitendra; Saxena, Anish; Chowdhury, Arup R.

    2016-04-01

    SW-MW Imaging Infrared Spectrometer, the Hyperspectral optical imaging instrument is envisaged to map geomorphology and mineralogy of lunar surface. The instrument is designed to image the electro-magnetic energy emanating from moon's surface with high spectral and spatial resolution for the mission duration from an altitude of 100 km. It is designed to cover 0.8 to 5 μm in 250 spectral bands with GSD 80m and swath 20km. Primarily, there are three basic optical segments in the spectrometer. They are fore optics, dispersing element and focusing elements. The payload is designed around a custom developed multi-blaze convex grating optimized for system throughput. The considerations for optimization are lunar radiation, instrument background, optical throughput, and detector sensitivity. HgCdTe (cooled using a rotary stirling cooler) based detector array (500x256 elements, 30μm) is being custom developed for the spectrometer. Stray light background flux is minimized using a multi-band filter cooled to cryogenic temperature. Mechanical system realization is being performed considering requirements such as structural, opto-mechanical, thermal, and alignment. The entire EOM is planned to be maintained at 240K to reduce and control instrument background. Al based mirror, grating, and EOM housing is being developed to maintain structural requirements along with opto- mechanical and thermal. Multi-tier radiative isolation and multi-stage radiative cooling approach is selected for maintaining the EOM temperature. EOM along with precision electronics packages are planned to be placed on the outer and inner side of Anti-sun side (ASS) deck. Power and Cooler drive electronics packages are planned to be placed on bottom side of ASS panel. Cooler drive electronics is being custom developed to maintain the detector temperature within 100mK during the imaging phase. Low noise detector electronics development is critical for maintaining the NETD requirements at different target

  16. Lightweight Tunable Infrared Filter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Michigan Aerospace Corporation has developed spaceflight qualified compact tunable Fabry-Perot interferometers for a number of applications, from ranging direct...

  17. Infomax Algorithm for Filtering Airwaves in the Field of Seabed Logging

    Directory of Open Access Journals (Sweden)

    Adeel Ansari

    2014-04-01

    Full Text Available This research focuses on applying Independent Component Analysis (ICA in the field of Seabed Logging (SBL. ICA is a statistical method for transforming an observed multidimensional or multivariate dataset into its constituent components (sources that are statistically as independent from each other as possible. ICA-type de-convolution algorithm, Infomax is suitable for mixed signals de-convolution, is proposed and considered convenient depending upon the nature of the source and noise model, in the application of seabed logging. Infomax is applied in the domain of marine Controlled Source Electro Magnetic (CSEM sensing method used for the detection of hydrocarbons based reservoirs in seabed logging application. The task is to identify the air waves and to filter them out. The infomax algorithm of ICA is considered for filtering the airwaves.

  18. 基于NLMS自适应滤波的近红外光谱去噪处理方法研究%Preprocessing Methods of Near-Infrared Spectrum Based on NLMS Adaptive Filtering

    Institute of Scientific and Technical Information of China (English)

    陈丛; 卢启鹏; 彭忠琦

    2012-01-01

    The normalized least mean square(NLMS) adaptive filtering method is introduced to get the preprocessing of near-infrared (NIR) spectrum in order to deduct the noise from Near-infrared spectrum. Fifty-one soil samples are served as the target and the application of NLMS adaptive filtering method in NIR spectrum preprocessing is discussed. The result after denoising is related to the real organic content of soil samples, then constructing a model according to this. Experimental results show that the correlation coefficient of the prediction set is improved from 0. 8284 to 0. 9654, and the root mean square error of prediction (RMSEP) is reduced from 0. 3385 to 0. 1606 after denoising with NLMS adaptive filter. So NLMS adaptive filter has a good effect in denoising the NIR spectrum. And it is also very useful to make the final model more representative, stable and robust. NLMS adaptive filter provides a new method for near-infrared sprctrum preprocessment.%为了去除直接采集的近红外(NIR)光谱中含有的噪声,将归一化最小均方(NLMS)自适应滤波方法引入到NIR光谱去噪领域中.以51份土壤样品的NIR光谱为研究对象,探讨NLMS自适应滤波方法在NIR光谱预处理中的应用,并将处理后的结果与土壤中有机质的含量相关联,建立模型.结果表明,通过NLMS自适应滤波去噪后的光谱,预测集的相关系数r由处理前的0.8284提高至0.9654,预测均方根误差(RMSEP)由处理前的0.3385降至0.1606.由此可见,NLMS自适应滤波对NIR光谱的去噪有显著效果,可以有效地提高光谱的分析精度和模型的稳健性,为NIR光谱的预处理提供了一种新方法.

  19. Electro-magnetic physics studies at RHIC: Neutral pion production, direct photon HBT, photon elliptic flow in gold-gold collisions at sqrt(s_NN) = 200 GeV and the Muon Telescope Detector simulation

    Science.gov (United States)

    Lin, Guoji

    Electro-magnetic (E&M) probes such as direct photons and muons (mu) are important tools to study the properties of the extremely hot and dense matter created in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC). In this thesis, several topics of E&M physics will be addressed, including neutral pion (pi0) production, direct photon HBT, and photon elliptic flow (v2) in Au+Au collisions at sNN = 200 GeV. A discussion on the simulation study of the new Muon Telescope Detector (MTD) will also be presented. The pi0 production is a fundamental measurement of hadron production and prerequisite for the background study of direct photons. Neutral pions are reconstructed using the photons detected by the STAR Barrel Electro-magnetic Calorimeter (BEMC) and the Time Projection Chamber (TPC). Spectra of pi 0 are measured at transverse momentum 1 information of the system size throughout the whole collision. A first attempt of direct photon HBT study at RHIC in 200 GeV Au+Au collisions is done using photons detected by the STAR BEMC and TPC. All unknown correlation at small Qinv is observed, whose magnitude is much larger than the expected HBT signal, and possible causes of the correlation will be discussed. Direct photon elliptic flow (v2) at intermediate to high pT is sensitive to the source of direct photon production. Results of inclusive photon v2 in 200 GeV Au+Au collisions are presented. The v2 of pi0 decay photons is calculated from the previously published pi results. The comparison between inclusive and decay photon v 2 indicates that direct photon v2 is small. A new large-area Muon Telescope Detector at mid-rapidity at RHIC is proposed and under investigation, using the Long-strip Multi-Gap Resistive Plate Chamber (Long-MRPC). Simulations indicate that the MTD can effectively identify mu and reject hadron backgrounds, and it can serve as a mu trigger. A beam test result of the Long-MRPC at Fermi National Accelerator Laboratory (FNAL) is also discussed.

  20. 电励磁双凸极电机转矩脉动抑制的控制策略%The Control Strategies of Torque Ripple Suppression about Doubly Salient Electro-Magnetic Motor

    Institute of Scientific and Technical Information of China (English)

    邹治锐; 陈世元

    2013-01-01

    造成电励磁双凸极电机转矩脉动的原因有很多,通过适当的控制策略可以优化某些因素从而改善转矩脉动.从控制策略方面总结了近年来优化转矩脉动的研究成果,介绍了几种有效的控制方法,大体思路可以从改善绕组相电流(包括稳定相电流、消去谐波电流、电流矢量分解等)、优化开关角度弥补换相电流缺陷以及优化输出转矩控制等方面来减小转矩脉动.%There are many factors cause torque ripple of doubly salient electro - magnetic motor. Appropriate control strategies can optimize some factors to improve torque ripple. The research achievements about torque ripple optimization from the control strategy in recent years were summarized, and some feasible methods was introduced to reduce torque ripple. The general ideas involve improving the winding current (including stable phase current, elimination harmonic current, current vector decomposition,etc.),optimizing the switch angle that made up in phase current defect and optimized output torque control,etc.

  1. Objective assessment of skin tightening in Asians using a water-filtered near-infrared (1,000–1,800 nm device with contact-cooling and freezer-stored gel

    Directory of Open Access Journals (Sweden)

    Tanaka Y

    2013-06-01

    Full Text Available Yohei Tanaka,1–3 Yuichiro Tsunemi,2 Makoto Kawashima,2 Naoto Tatewaki,3 Hiroshi Nishida31Clinica Tanaka Plastic, Reconstructive Surgery and Anti-aging Center, Nagano, 2Department of Dermatology, Tokyo Women's Medical University, Tokyo, 3Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, JapanBackground: Near-infrared has been shown to penetrate deeper than optical light sources independent of skin color, allowing safer treatment for the Asian skin type. Many studies have indicated the efficacy of various types of devices, but have not included a sufficiently objective evaluation. In this study, we used three-dimensional imaging for objective evaluation of facial skin tightening using a water-filtered near-infrared device.Methods: Twenty Japanese patients were treated with the water-filtered near-infrared (1,000–1,800 nm device using a contact-cooling and nonfreezing gel stored in a freezer. Three-dimensional imaging was performed, and quantitative volume measurements were taken to evaluate the change in post-treatment volume. The patients then provided their subjective assessments.Results: Objective assessments of the treated cheek volume evaluated by a three-dimensional color schematic representation with quantitative volume measurements showed significant improvement 3 months after treatment. The mean volume reduction at the last post-treatment visit was 2.554 ± 0.999 mL. The post-treatment volume was significantly reduced compared with the pretreatment volume in all patients (P < 0.0001. Eighty-five percent of patients reported satisfaction with the improvement of skin laxity, and 80% of patients reported satisfaction with improvement of rhytids, such as the nasolabial folds. Side effects, such as epidermal burns and scar formation, were not observed throughout the study.Conclusion: The advantages of this water-filtered near-infrared treatment are its high efficacy for skin tightening

  2. Multi-physics simulation and fabrication of a compact 128 × 128 micro-electro-mechanical system Fabry-Perot cavity tunable filter array for infrared hyperspectral imager.

    Science.gov (United States)

    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.

  3. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  4. Optical properties of plasma ion-assisted deposition silicon coatings: application to the manufacture of blocking filters for the near-infrared region.

    Science.gov (United States)

    Bruynooghe, Stephane

    2008-05-01

    I report on the preparation and characterization of optical constants of silicon coatings deposited by an electron beam gun with plasma ion-assisted deposition. With the fabrication of long-wave-pass filters the reliability of the optical constants is assured.

  5. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter

    Directory of Open Access Journals (Sweden)

    Amor Chowdhury

    2016-09-01

    Full Text Available The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.

  6. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter.

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-09-15

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.

  7. Efficient, Narrow-Pass-Band Optical Filters

    Science.gov (United States)

    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.

  8. Filter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H.; Doty, Patrick F.

    2017-08-01

    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  9. Holographic interference filters

    Science.gov (United States)

    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.

  10. A Long Wave Infrared (LWIR) spectral imager (7.7 to 12.3 μ) based on cooled detector array and high resolution Circular Variable Filter (CVF)

    Science.gov (United States)

    Cabib, Dario; Lavi, Moshe; Gil, Amir; Ohel, Eran; Dolev, Jacob; Milman, Uri

    2013-10-01

    Spectral imagers in the Long Wave IR spectral range (8 to 12 microns) suffer from the problem of high production costs because the existing commercial cooled array detectors are expensive, and in fact they are prohibitively expensive for many applications. As a result, the drive to lower the cost of Long Wave IR spectral imagers is strong: this is the main motivation for CI to investigate a new design that allows these spectral imagers to be more affordable. One area of possible cost reduction without relinquishing the advantages of a cryogenically cooled detector is the method used to provide the spectral information. CI Systems has developed a long wave IR (7.7 to 12.3 micron) spectral imager concept using a Circular Variable Filter (CVF), (a proprietary component based on multiple layer interference filter technology) which has advantages over the interferometric Fourier Transform method commonly used in this spectral range. The CVF method has its own development challenges; however, once proven, this concept may be more suitable and affordable for applications in which a spectral resolution of 0.5% of the wavelength (or 50 nm at 10 μ) is required. The design of the optical system must minimize background signals without being cooled to cryogenic temperatures, so we called it VIrtually COld (or VICO). CI is in the final stages of prototype building and characterization. Present initial calibration results and measurement examples are given in this paper.

  11. Equivalent Electro-magnetic Transient Model Based on Dynamic Reluctance for Magnetically Controlled Shunt Reactor%基于动态磁阻的磁控式并联电抗器等效电抗暂态模型

    Institute of Scientific and Technical Information of China (English)

    郑伟杰; 周孝信

    2011-01-01

    A mathematical model which describes the nonlinear magnetic saturation characteristics of magnetically controlled shunt reactor (MCSR) for extra and ultra voltage was proposed. Based on dynamic reluctance, instantaneous equivalent reactor calculation algorithm was proposed and used to reflect the dynamic characteristics of a shunt reactor system with AC-DC mixed excitation, while inverse-hyperbolic function describing the nonlinear characteristics, damping implicit trapezoidal integration algorithm was used to differentiate the reactor, equivalent electro-magnetic transient model was established accordingly, which is compatible with the electromagnetic transient algorithm. Advanced digital power system simulator (ADPSS) has contained the model, site operation parameters of MCSR in project were used as input in the simulation example, the results confirm the accuracy of model.%提出一种描述超/特高压磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)非线性磁饱和特性的实用化解耦电磁暂态模型.基于动态磁阻的思想,提出瞬时等效电抗的算法,反映了交直流混合励磁条件下饱和等效电抗的实时动态变化特性:以反双曲函数描述非线性磁路特性,对耦合磁路方程进行解耦,并用带阻尼的隐式梯形积分算法对瞬时等效电抗进行差分化,建立电磁暂态模型,能够与电磁暂态计算相兼容.已在电力系统全数字实时仿真装置(advanced digital power system simulator,ADPSS)中编程实现了仿真模型的工程化应用,并搭建标准算例,以工程投运的MCSR现场运行参数为模型输入量,进行仿真,计算结果数值精确,波形吻合,验证了模型的正确性.

  12. 针对FPGA密码芯片的近场差分电磁分析攻击%Differential ElectroMagnetic analysis attacks on FPGA cipher chip in near field

    Institute of Scientific and Technical Information of China (English)

    陈开颜; 余浩; 邹程; 吴恒旭

    2013-01-01

    为探究现场可编程门阵列(FPGA)密码芯片运行时电磁辐射造成的涉密信息泄漏情况,研究了互补金属氧化物半导体(CMOS)电路直接电磁辐射的原理,构建了FPGA密码芯片的近场电磁辐射模型。根据这个模型,探讨了近场电磁辐射测量点的选取,采用电磁扫描的方法解决了电磁探头在FPGA表面电磁信号采集的定位问题。此外,在阐释了差分电磁分析(DEMA)攻击原理的同时,完成了高级加密标准(AES)的FPGA电路设计,针对FPGA密码系统的DEMA攻击实验表明,通过电磁扫描找到最佳测量点,在42000个样本的条件下能成功破解AES密码电路的128 bit密钥。%To do research for physical information leaked by Electromagnetic(EM)radiations from Field Programmable Gate Arrays(FPGA)cipher chip during its operation, this paper analyzes the principle of direct electromagnetic emanations for Com-plementary Metal-Oxide-Semiconductor(CMOS)circuit, and then a near-field leakage model about FPGA is designed. According to this model, the technique, EM scanning, is used to tackle the problem of the localization of the spatial position of the crypto-processor, in putting an electricmagnetic near-field sensor above the chip. Moreover, Advanced Encryption Standard(AES)circuit is completed based on FPGA cryptosystem and Differential ElectroMagnetic Analysis(DEMA)is introduced. As a result, practical experiment has shown that an attacker can extract the secret 128-bit key using 42000 traces of AES cryptographic device under the condition of having localized the optimal leaking spots characterized by mostly data-dependent EM emissions.

  13. A Novel Rectifier Topology for Doubly Salient Electro-magnetic Generators%一种用于电励磁双凸极发电机的新型半控整流拓扑研究

    Institute of Scientific and Technical Information of China (English)

    陈冉; 陈志辉; 毛志鑫; 段晴晴

    2012-01-01

    The switched reluctance generation (SRG) mode is widely used in doubly salient electro-magnetic generators. In this paper, an optimized topology of SRG was proposed. Firstly, the magnetic energy relationship of the double salient generator was analyzed. According to the analysis, an optimized topology that is the Boost Half-wave Rectifier (BHR) was proposed. With the help of Finite Element Analysis (FEA), the performance of the BHR and SRG generation mode were compared, for a 12/8 poles doubly salient electromagnetic generator. Based on that simulation, the factors that affect the armature currents were analyzed when the generator is under different loads. Experimentation of a prototype verified the correctness of the FEA analysis. Analysis results show that the maximum power of the doubly salient generator is improved significantly when it use the new generation topology of BHR compared to the traditional power generation mode of SRG.%首先讨论电励磁双凸极电机开关磁阻发电(switched reluctance generation,SRG)方式的优化思路,提出一种新型的中点连接型半控整流发电拓扑,并借助有限元仿真软件,针对一台12/8极电励磁双凸极发电机,比较新型发电拓扑与传统SRG发电方式下的电机工作方式,分析影响发电机电枢电流大小的因素以及对电机发电功率的影响.对原理样机的实验验证了仿真分析的准确性.分析结果表明:在相同负载条件下,采用新型发电拓扑的电励磁双凸极发电机,最大功率值比传统SRG发电方式有明显提升.

  14. Optimal filtering

    CERN Document Server

    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

  15. A potassium Faraday anomalous dispersion optical filter

    Science.gov (United States)

    Yin, B.; Shay, T. M.

    1992-01-01

    The characteristics of a potassium Faraday anomalous dispersion optical filter operating on the blue and near infrared transitions are calculated. The results show that the filter can be designed to provide high transmission, very narrow pass bandwidth, and low equivalent noise bandwidth. The Faraday anomalous dispersion optical filter (FADOF) provides a narrow pass bandwidth (about GHz) optical filter for laser communications, remote sensing, and lidar. The general theoretical model for the FADOF has been established in our previous paper. In this paper, we have identified the optimum operational conditions for a potassium FADOF operating on the blue and infrared transitions. The signal transmission, bandwidth, and equivalent noise bandwidth (ENBW) are also calculated.

  16. Application of adaptive filter to noninvasive biochemical examination by near infrared spectroscopy%自适应滤波在近红外无创生化分析中的应用

    Institute of Scientific and Technical Information of China (English)

    卢启鹏; 陈丛; 彭忠琦

    2012-01-01

    Subtracted blood volume spectrometry was employed to the noninvasive biochemical examination with near infrared spectroscopy(NIRS) to eliminate the influence of tissues. To raise the Signal to Noise Ratio(SNR) of the NIRS pulse wave signal needed by the spectral subtraction, an effective a-daptive filter method was proposed to process the pulse wave signal. The principles of Least Mean Square(LMS) adaptive filter were described, and a new adaptive filtering way fit for the pulse wave signal of this experiment was proposed. Then, a 16-pixel near-infrared pulse wave acquisition system made by ourselves was used to collect the pulse wave signals of human body. Finally, the proposed a-daptive filtering way was used to process the NIRS pulse wave signals and analyze the results. The result shows that the noise level of blood spectrum has reduced from 800μAU to 12μAU after spectralsubtraction by using the proposed method, and the related coefficient of pulse wave of adjacent wavelength has raised from 0. 9940 to 0. 9999. The analysed result verifies that the method is effective in the NIR noninvasive biochemical examination area.%提出用血流容积差光谱相减法来消除近红外无创生化分析中组织背景的干扰.为提高光谱相减中所需获得的脉搏波近红外光谱信号的信噪比,研究了自适应滤波处理方法.介绍了最小均方算法(LMS)自适应滤波的基本原理,在此基础上提出了一种适用于处理本实验脉搏波光谱信号的自适应滤波方法;采用实验室自行研制的16元近红外脉搏波采集系统,获得人体脉搏波光谱信号;最后,利用提出的自适应滤波方法处理脉搏波光谱信号并分析其滤波效果.结果表明,利用该方法处理采集的脉搏波信号,可使血流容积光谱相减后血液光谱吸光度噪声由800 μAU降低至12 μAU,相邻波长的脉搏波相关系数由0.994 0提高至0.999 9.分析结果说明该自适应滤波方法可以有效地应

  17. Photoinactivation Using Visible Light Plus Water-Filtered Infrared-A (vis+wIRA) and Chlorine e6 (Ce6) Eradicates Planktonic Periodontal Pathogens and Subgingival Biofilms

    Science.gov (United States)

    Al-Ahmad, Ali; Walankiewicz, Aleksander; Hellwig, Elmar; Follo, Marie; Tennert, Christian; Wittmer, Annette; Karygianni, Lamprini

    2016-01-01

    Alternative treatment methods for pathogens and microbial biofilms are required due to the widespread rise in antibiotic resistance. Antimicrobial photodynamic therapy (aPDT) has recently gained attention as a novel method to eradicate pathogens. The aim of this study was to evaluate the antimicrobial effects of a novel aPDT method using visible light (vis) and water infiltrated infrared A (wIRA) in combination with chlorine e6 (Ce6) against different periodontal pathogens in planktonic form and within in situ subgingival oral biofilms. Eight different periodontal pathogens were exposed to aPDT using vis+wIRA and 100 μg/ml Ce6 in planktonic culture. Additionally, pooled subgingival dental biofilm was also treated by aPDT and the number of viable cells determined as colony forming units (CFU). Live/dead staining was used in combination with confocal laser scanning microscopy to visualize and quantify antimicrobial effects within the biofilm samples. Untreated negative controls as well as 0.2% chlorhexidine-treated positive controls were used. All eight tested periodontal pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Actinomyces odontolyticus, Fusobacterium nucleatum, Parvimonas micra, Slackia exigua, and Atopobium rimae and the aPDT-treated subgingival biofilm were eliminated over the ranges of 3.43–8.34 and 3.91–4.28 log10 CFU in the log10 scale, respectively. Thus, aPDT showed bactericidal effects on the representative pathogens as well as on the in situ subgingival biofilm. The live/dead staining also revealed a significant reduction (33.45%) of active cells within the aPDT-treated subgingival biofilm. Taking the favorable tissue healing effects of vis+wIRA into consideration, the significant antimicrobial effects revealed in this study highlight the potential of aPDT using this light source in combination with Ce6 as an adjunctive method to treat periodontitis as well as periimplantitis. The

  18. Normal incidence narrowband transmission filtering in zero-contrast gratings

    CERN Document Server

    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.

  19. Ultraviolet filters.

    Science.gov (United States)

    Shaath, Nadim A

    2010-04-01

    The chemistry, photostability and mechanism of action of ultraviolet filters are reviewed. The worldwide regulatory status of the 55 approved ultraviolet filters and their optical properties are documented. The photostabilty of butyl methoxydibenzoyl methane (avobenzone) is considered and methods to stabilize it in cosmetic formulations are presented.

  20. Nonuniformity correction algorithm for infrared focalplane arrays based on adaptive-filter%基于自适应滤波的红外焦平面阵列非均匀性校正算法

    Institute of Scientific and Technical Information of China (English)

    周慧鑫; 拜丽萍; 秦翰林; 赖睿; 王炳健; 刘群昌

    2009-01-01

    The performance of nonuniformity correction(NUC) would be deteriorated by time shift in the response of detectors in infrared focal plane arrays(IRFPAs). Therefore, a scene-based NUC algorithm is presented. In this algorithm, an adaptive filter bank is applied to estimate NUC parameters for every detector in IRFPAs. And the parameters are renewed by utilizing current imaging information to reduce the influence imposed by response drift on NUC. For an image with a nonuniformity of 26.12%, nonuniformities after 1 h correction are 3.122% for two-point NUC algorithm, 1.893% for Kalman-filter NUC algorithm and around 1.856% for the presented algorithm, which means the presented algorithm can achieve the best NUC effect steadily.%红外探测器响应漂移特性会降低红外焦平面阵列(IRFPA)非均匀性校正的精度.针对该问题提出了一种基于场景的IRFPA非均匀性校正算法.该算法利用所获得的序列成像场景信息,采用一种基于快速自适应滤波器的最优化递归估计方法来获得非均匀性校正参数,并利用当前的成像信息来更新校正参数,以此降低探测器响应漂移特性对非均匀性校正的影响.算法仿真实验显示,对非线性参数为26.12%的同一图像,使用该算法、两点校正算法和卡尔曼滤波校正算法校正1 h后,可分别将非线性参数降至1.856%,3.122%和1.893%,说明该算法可获得稳定而较好的非均匀性校正效果.

  1. The Study of the Properties of PDP Filter Based on Phthalocyanine and Diimonium as Near-Infrared Ray Absorbing Dye%基于酞菁类和二亚铵类近红外吸收染料的等离子显示器滤光膜的性能对比研究

    Institute of Scientific and Technical Information of China (English)

    李斌; 彭德权; 潘晓勇; 舒宝; 刘佳其

    2012-01-01

    等离子显示器中的潘宁气体在放电过程中会产生近红外线、氖黄光,干扰遥控器等设备,影响观看效果,需安装滤光膜。文章对以酞菁类、二亚铵类为近红外吸收染料的PDP滤光膜进行了对比研究,实验结果表明,酞菁类、二亚铵类滤光膜具有良好的耐湿热、耐高温性能,二亚铵类滤光膜相对于酞菁类滤光膜具有较好的光稳定性能,且可见光区透过率可达到60%以上,适合应用于高透过率PDP滤光膜。%The penning gas of PDP will produce near-infrared ray, neon yellow light during the discharge process, and affect their performance, the PDP filter must be used to prevent them. The properties of PDP filter which near-infrared ray absorbing dye used phthalocyanine or diimonium was investigated. The results show that the PDP filter of phthalocyanine and diimonium have good resistance to heat and high temperature performance. The PDP filter of diimonium is better than the PDP filter of phthalocyanine on the property of light stability, and visible light transmittance of more than 60%, so it is suitable for high transmittance filter films.

  2. Food Filter

    Institute of Scientific and Technical Information of China (English)

    履之

    1995-01-01

    A typical food-processing plant produces about 500,000 gallons of waste water daily. Laden with organic compounds, this water usually is evaporated or discharged into sewers.A better solution is to filter the water through

  3. New ion-assisted filtered cathodic arc deposition (IFCAD) technology for producing advanced thin films on temperature-sensitive substrates

    Science.gov (United States)

    Fulton, Michael L.

    1999-10-01

    An innovative Ion-Assisted Filtered Cathodic Arc Deposition (IFCAD) system has been developed for low temperature production of thin-film coatings. The IFCAD system employs electro-magnetic and mechanical filtering techniques to remove unwanted macroparticles and neutral atoms from the plasma stream. Therefore, only ions within a defined energy range arrive at the substrate surface, depositing thin-films with excellent mechanical and optical properties. Ion- Assisted-Deposition is coupled with Filtered Cathodic Arc technology to enhance and modify the arc deposited thin- films. Using an advanced computer controlled plasma beam scanning system, high quality, large area, uniform IFCAD multi-layer film structures are attained. Amorphous Diamond- Like-Carbon films (up to 85% sp3 bonded carbon; and micro- hardness greater than 50 GPa) have been deposited in multi- layer thin-film combinations with other IFCAD source materials (such as: Al2O3) for optical and tribological applications. Rutile TiO2 (refractive index of 2.8 at 500 nm) has been deposited with this technology for advanced optical filter applications. The new IFCAD technology has been included in development programs, such as: plastic and glass lens coatings for optical systems; wear resistant coatings on various metal substrates, ultra smooth, durable, surface hydrophobic coatings for aircraft windows; EUV coatings for space instrumentation; transparent conductive coatings; and UV protective coatings for solar cell concentrator plastic Fresnel lens elements for space power.

  4. Discussion on the Evaluation Standards of Electro-magnetic Ambient Effect for Electrified Railways and Urban Rail Transit Construction Projects%电气化铁路及城市轨道交通建设项目电磁环境影响评价标准探讨

    Institute of Scientific and Technical Information of China (English)

    尹坚

    2011-01-01

    Author reviewed the evaluation standards and their application of electro-magnetic ambient effect for electrified railways and urban rail transit construction projects, and by contrasting to the international mainstream protection standards, analysed current domestic standards and existing problems in the application including that technical principles of electro-magnetic protection are not scientifical, limiting values are too strict, errors exist in introducing CCIR standards for the evaluation of TV reception effect, lack of specialization. Then the author proposes to improve the current standards following the principles of prevention protection techniques, referring to the international standards guidelines, to establish acurate application standards for evaluating the TV reception effect, with related parameters and standard values specified.%对电气化铁路、城市轨道交通建设项目电磁环境影响评价标准及其应用进行了回顾.对照国际主流电磁防护标准,分析了现行标准及其应用中存在的问题,包括电磁辐射防护标准技术原则不科学、标准限值过严,电视接收影响评价引用CCIR标准有误、规范性欠缺.提出遵循预防性防护技术原则、参照国际标准导则修订完善现有标准的建议,要求有关电视接收的影响评价正确引用标准,规范相关参数和标准值.

  5. Steps Toward a Common Near-Infrared Photometric System

    CERN Document Server

    Tokunaga, A T

    2007-01-01

    The proliferation of near-infrared (1--5 $\\mu$m) photometric systems over the last 30 years has made the comparison of photometric results difficult. In an effort to standardize infrared filters in use, the Mauna Kea Observatories near-infrared filter set has been promoted among instrument groups through combined filter production runs. The characteristics of this filter set are summarized, and some aspects of the filter wavelength definitions, the flux density for zero magnitude, atmospheric extinction coefficients, and color correction to above the atmosphere are discussed.

  6. Generalised Filtering

    Directory of Open Access Journals (Sweden)

    Karl Friston

    2010-01-01

    Full Text Available We describe a Bayesian filtering scheme for nonlinear state-space models in continuous time. This scheme is called Generalised Filtering and furnishes posterior (conditional densities on hidden states and unknown parameters generating observed data. Crucially, the scheme operates online, assimilating data to optimize the conditional density on time-varying states and time-invariant parameters. In contrast to Kalman and Particle smoothing, Generalised Filtering does not require a backwards pass. In contrast to variational schemes, it does not assume conditional independence between the states and parameters. Generalised Filtering optimises the conditional density with respect to a free-energy bound on the model's log-evidence. This optimisation uses the generalised motion of hidden states and parameters, under the prior assumption that the motion of the parameters is small. We describe the scheme, present comparative evaluations with a fixed-form variational version, and conclude with an illustrative application to a nonlinear state-space model of brain imaging time-series.

  7. Notch filter

    Science.gov (United States)

    Shelton, G. B. (Inventor)

    1977-01-01

    A notch filter for the selective attenuation of a narrow band of frequencies out of a larger band was developed. A helical resonator is connected to an input circuit and an output circuit through discrete and equal capacitors, and a resistor is connected between the input and the output circuits.

  8. Characterization of an erbium-doped fiber amplifier as a light source and development of a near-infrared spectrophotometer based on the EDFA and an acoustooptic tunable filter.

    Science.gov (United States)

    Tran, C D; Gao, G H

    1996-07-01

    A novel light source for the near-infrared region which has the highest intensity and widest spectral bandwidth of all near-IR light sources has been developed. The system is based on a single-mode fiber (about 18 m long) doped with Er3+ ion. The doped ion produces amplified spontaneous emission (ASE) in the near-IR region (from 1500 to 1600 nm) when it is excited by a diode laser at 980 nm. Because the diode laser is fusion-spliced directly to the doped fiber, the system is compact, all-solid-state, reliable, and stable and requires little maintenance. Its ASE output intensity was found to be comparable with those of diode lasers currently available for this near-IR region and is much higher than those of conventional halogen-tungsten lamps and the so-called (high-intensity) superluminescent light emitting diodes (SLEDs). Its spectral bandwidth is, however, much wider than those of the diode lasers and the SLEDs. Even higher intensity can be obtained from the doped fiber when a low-intensity (1 mW) light from a 1550-nm laser diode is introduced into the doped fiber. The intensity is enhanced (up to 7 times compared to the ASE) because the input light is amplified by the doped fiber. Furthermore, the output intensity of this erbium-doped fiber amplifier (EDFA) can be appropriately adjusted to provide relatively higher output intensity at any range of wavelengths (within this 1500-1600-nm region) by simply changing the temperature and/or the driven current of the input diode laser. Subsequently, an acoustooptic tunable filter was used to provide a means to spectrally tune the EDFA rapidly and to develop an all-solid-state, compact near-IR spectrophotometer which not only is very sensitive, stable, and reliable but also has a very high throughput. This spectrophotometer can detect water in ethanol at a limit of detection of 10 ppm. More importantly, the high through-put makes it possible to use the instrument to measure spectra of highly absorbing samples (e

  9. The autocorrelated noise filtering problem: the ISMC filter in a specific case of distance measuring

    CERN Document Server

    Prattico, Flavio

    2013-01-01

    In a previous paper we were working on a electronic travel aid for blind people based on infrared sensors. The signals coming from them are affected by a great noise that also with the use of low pass filter cannot be clean well. Motivated by the improvement of the system, in this paper we show a novelty way to filter autocorrelated noise based on a probabilistic description of the process. We apply an indexed semi-Markov model in order to filter the signal coming from the infrared sensor. We conduce first of all a data analysis on the noise in order to understand well its form. We give the general formulation of the new ISMC filter and at last we compare the results with a particular kind of Kalman filter for the specific stochastic application.

  10. CRYSTAL FILTER TEST SET

    Science.gov (United States)

    CRYSTAL FILTERS, *HIGH FREQUENCY, *RADIOFREQUENCY FILTERS, AMPLIFIERS, ELECTRIC POTENTIAL, FREQUENCY, IMPEDANCE MATCHING , INSTRUMENTATION, RADIOFREQUENCY, RADIOFREQUENCY AMPLIFIERS, TEST EQUIPMENT, TEST METHODS

  11. Simulation Analysis of the Electro-Magnetic Transient on High Voltage Submarine Cable of the Offshore Wind Farms%海上风电场海底高压电缆电磁暂态过程的仿真分析

    Institute of Scientific and Technical Information of China (English)

    黄辉; 郑明; 蓝锦标; 李迪

    2012-01-01

    In order to better determine the selection requirements of the high voltage submarine cable of the wind farms, the corresponding submarine cable simulation model is built using PSCAD/EMTDC software. The simulation is made for frequency overvoltage, switching overvoltage and lightning overvaltage with different characteristics of the transient process. Effects of the three kinds of overvoltage on the cable insulation are also considered in different system conditions. For switching overvoltage, the study is focused on the influence of the closing resistance on the overvoltage, while for lightning overvoltage focused on the lightning intruding to transmission lines. The simulation results show that the submarine cable structure parameters of each layer exert different impacts on the submarine cable electro-magnetic transient, and the conductor layer, insulation layer and HDPE layer have more remarkable impacts. In addition, the material of the sheath layer and the main insulation layer have impacts on the electro -magnetic transient.%为了能更好地确定海上风电场海底高压电缆的选型要求,使用PSCAD/EMTDC软件建立相应的海上风电场仿真计算模型.针对海上风电场工频过电压、操作过电压和雷电过电压这3种电磁暂态过程的不同特点,进行仿真,并且考虑了不同的系统条件下上述3种过电压对电缆绝缘的影响.在操作过电压中,重点研究了合闸电阻对过电压的影响;而在雷电过电压中重点研究的是架空线路受雷电侵入波的过电压.仿真结果表明,海底电缆各层的结构参数对海底电缆的电磁暂态有着不同程度的影响,其中导体层、绝缘层、HDPE层对海底电缆的电磁暂态影响尤为明显.另外,海底高压电缆的护套层材料和主绝缘层材料也对电磁暂态有影响.

  12. Digital filters

    CERN Document Server

    Hamming, Richard W

    1997-01-01

    Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s

  13. Near-infrared and Mid-infrared Spectroscopy with the Infrared Camera (IRC) for AKARI

    CERN Document Server

    Ohyama, Youichi; Matsuhara, Hideo; Wada, Takehiko; Kim, Woojung; Fujishiro, Naofumi; Uemizu, Kazunori; Sakon, Itsuki; Cohen, Martin; Ishigaki, Miho; Ishihara, Daisuke; Ita, Yoshifusa; Kataza, Hirokazu; Matsumoto, Toshio; Murakami, Hiroshi; Oyabu, Shinki; Tanabe, Toshihiko; Takagi, Toshinobu; Ueno, Munetaka; Usui, Fumio; Watarai, Hidenori; Pearson, Chris P; Takeyama, Norihide; Yamamuro, Tomoyasu; Ikeda, Yuji

    2007-01-01

    The Infrared Camera (IRC) is one of the two instruments on board the AKARI satellite. In addition to deep imaging from 1.8-26.5um for the pointed observation mode of the AKARI, it has a spectroscopic capability in its spectral range. By replacing the imaging filters by transmission-type dispersers on the filter wheels, it provides low-resolution (lambda/d_lambda ~ 20-120) spectroscopy with slits or in a wide imaging field-of-view (approximately 10'X10'). The IRC spectroscopic mode is unique in space infrared missions in that it has the capability to perform sensitive wide-field spectroscopic surveys in the near- and mid-infrared wavelength ranges. This paper describes specifications of the IRC spectrograph and its in-orbit performance.

  14. Convergent Filter Bases

    OpenAIRE

    Coghetto Roland

    2015-01-01

    We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres) and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections).

  15. Convergent Filter Bases

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-09-01

    Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

  16. NOVEL MICROWAVE FILTER DESIGN TECHNIQUES.

    Science.gov (United States)

    ELECTROMAGNETIC WAVE FILTERS, MICROWAVE FREQUENCY, PHASE SHIFT CIRCUITS, BANDPASS FILTERS, TUNED CIRCUITS, NETWORKS, IMPEDANCE MATCHING , LOW PASS FILTERS, MULTIPLEXING, MICROWAVE EQUIPMENT, WAVEGUIDE FILTERS, WAVEGUIDE COUPLERS.

  17. Miniaturized dielectric waveguide filters

    Science.gov (United States)

    Sandhu, Muhammad Y.; Hunter, Ian C.

    2016-10-01

    Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.

  18. Infrared thermography

    CERN Document Server

    Meola, Carosena

    2012-01-01

    This e-book conveys information about basic IRT theory, infrared detectors, signal digitalization and applications of infrared thermography in many fields such as medicine, foodstuff conservation, fluid-dynamics, architecture, anthropology, condition monitoring, non destructive testing and evaluation of materials and structures.

  19. Filter quality of pleated filter cartridges.

    Science.gov (United States)

    Chen, Chun-Wan; Huang, Sheng-Hsiu; Chiang, Che-Ming; Hsiao, Ta-Chih; Chen, Chih-Chieh

    2008-04-01

    The performance of dust cartridge filters commonly used in dust masks and in room ventilation depends both on the collection efficiency of the filter material and the pressure drop across the filter. Currently, the optimization of filter design is based only on minimizing the pressure drop at a set velocity chosen by the manufacturer. The collection efficiency, an equally important factor, is rarely considered in the optimization process. In this work, a filter quality factor, which combines the collection efficiency and the pressure drop, is used as the optimization criterion for filter evaluation. Most respirator manufacturers pleat the filter to various extents to increase the filtration area in the limit space within the dust cartridge. Six sizes of filter holders were fabricated to hold just one pleat of filter, simulating six different pleat counts, ranging from 0.5 to 3.33 pleats cm(-1). The possible electrostatic charges on the filter were removed by dipping in isopropyl alcohol, and the air velocity is fixed at 100 cm s(-1). Liquid dicotylphthalate particles generated by a constant output atomizer were used as challenge aerosols to minimize particle loading effects. A scanning mobility particle sizer was used to measure the challenge aerosol number concentrations and size distributions upstream and downstream of the pleated filter. The pressure drop across the filter was monitored by using a calibrated pressure transducer. The results showed that the performance of pleated filters depend not only on the size of the particle but also on the pleat count of the pleated filter. Based on filter quality factor, the optimal pleat count (OPC) is always higher than that based on pressure drop by about 0.3-0.5 pleats cm(-1). For example, the OPC is 2.15 pleats cm(-1) from the standpoint of pressure drop, but for the highest filter quality factor, the pleated filter needed to have a pleat count of 2.65 pleats cm(-1) at particle diameter of 122 nm. From the aspect of

  20. Design and Development of Tunable Filters for MEMS Adaptive Infrared Detectors%适用于微机电系统的自适应红外探测器的可调谐滤光器设计与开发

    Institute of Scientific and Technical Information of China (English)

    HUANG; H; WINCHESTER; K; W; DELL; J; M; FARAONE; L

    2006-01-01

    The combination of MEMS and high performance infrared (IR) detector technology offers a unique opportunity for new solutions to major challenges faced by a wide range of defense, commercial, communication, biomedical instrumenfrared detectors. The filter performance and the overall device integrity are significantly influenced by the design of the filter structure and the materials used for the key structural elements. The mechanical design and analysis of FP filter structures by means of finite element modeling is presented in this paper. The characterization of filter structural material, low temperature PECVD silicon nitride, and the determination of its mechanical properties are reported. Finally, the fabricated filter array is demonstrated.%微机电系统与高品质红外探测技术联合运用为国防、商业、通信、生物医学检测及环境监测等许多应用领域面临的一系列具有挑战性的问题提供了唯一可行的解决方案.可调谐法布里-玻罗滤光片是适用于微机电系统的红外探测器的核心部件.滤光片的结构设计和关键结构件的材料对于滤光片的性能和整个装置的完善性有重要影响.阐述了利用有限元建模进行法布里-玻罗滤光片机械设计和分析的方法.报告了滤光片的结构材料--用低温等离子增强化学沉积法制造的氮化硅的结构表征和机械性能测定方法和结果.最后展示了一些所制作的滤光片阵列.

  1. Composing morphological filters

    NARCIS (Netherlands)

    H.J.A.M. Heijmans (Henk)

    1995-01-01

    textabstractA morphological filter is an operator on a complete lattice which is increasing and idempotent. Two well-known classes of morphological filters are openings and closings. Furthermore, an interesting class of filters, the alternating sequential filters, is obtained if one composes openin

  2. Composing morphological filters

    NARCIS (Netherlands)

    Heijmans, H.J.A.M.

    1995-01-01

    A morphological filter is an operator on a complete lattice which is increasing and idempotent. Two well-known classes of morphological filters are openings and closings. Furthermore, an interesting class of filters, the alternating sequential filters, is obtained if one composes openings and closi

  3. Normal incidence filters using symmetry-protected modes in dielectric subwavelength gratings

    Science.gov (United States)

    Cui, Xuan; Tian, Hao; Du, Yan; Shi, Guang; Zhou, Zhongxiang

    2016-11-01

    We investigate narrowband transmission filters based on subwavelength-grating reflectors at normal incidence. Computational results show that the filtering is realized through symmetry-protected mode coupling. The guided mode resonances introduced by the slab layer allow flexible control of the filter frequencies. The quality factor of the filters could exceed 106. Dielectric gratings can be used over the entire range of electromagnetic waves, owing to their scale-invariant operations. Owing to the high refraction index and low index dispersion of semiconductors in the infrared range, these filters can be applied over a broad range from near infrared to terahertz frequencies.

  4. Tunable-Bandwidth Filter System

    Science.gov (United States)

    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

  5. Passive Power Filters

    CERN Document Server

    Künzi, R

    2015-01-01

    Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter struc tures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. P ractical aspects for the realization of power filters are also discussed.

  6. Infrared Imaging

    Science.gov (United States)

    Danchi, W.; Lawson, P.; Absil, O.; Akeson, R.; Bally, J.; Barry, R.; Beichman, C.; Belu, A.; Boyce, M.; Breckinridge, J.; Burrows, A.; Chen, C.; Cole, D.; Crisp, D.; Danner, R.; Deroo, P.; Coudé du Foresto, V.; Defrère, D.; Ebbets, D.; Falkowski, P.; Gappinger, R.; Haugabook, I.; Hanot, C.; Henning, T.; Hinz, P.; Hollis, J.; Hunyadi, S.; Hyland, D.; Johnston, K.; Kaltenegger, L.; Kasting, J.; Kenworthy, M.; Ksendzov, A.; Lane, B.; Laughlin, G.; Lay, O.; Liseau, R.; Lopez, B.; Millan-Gabet, R.; Martin, S.; Mawet, D.; Mennesson, B.; Monnier, J.; Murakami, N.; Noecker, C.; Nishikawa, J.; Pesesen, M.; Peters, R.; Quillen, A.; Ragland, S.; Rinehart, S.; Rottgering, H.; Scharf, D.; Serabyn, G.; Tamura, M.; Tehrani, M.; Traub, W.; Unwin, S.; Wilner, D.; Woilliez, J.; Woolf, N.; Zhao, M.

    2009-03-01

    A mid-infrared mission would enable the detection of biosignatures of Earth-like exoplanets around more than 150 nearby stars. The mid-infrared spectral region is attractive for characterizing exoplanets because contrast with the parent star brightness is more favorable than in the visible (10 million vs. 10 billion), and because mid-infrared light probes deep into a planet's troposphere. Furthermore, the mid-infrared offers access to several strong molecular features that are key signs of life, and also provides a measure of the effective temperature and size of a planet. Taken together, an infrared mission plus a visible one would provide a nearly full picture of a planet, including signs of life; with a measure of mass from an astrometric mission, we would have a virtually complete picture. A small infrared mission would have several telescopes that are rigidly connected, with a science return from the detection and characterization of super-Earth sized to larger planets near the HZ, plus a direct measure of the exozodi brightness in the HZ. In a large infrared mission, with formation-flying telescopes, planets from an Earth-twin and upwards in mass could be detected and characterized, as well as the exozodi. If proceeded by an astrometric mission, the detection phase could be skipped and the mission devoted to characterization, as in the visible case; lacking an astrometric mission, an infrared one could proceed alone, as was discussed for a visible coronograph, and with similar caveats. The technology needed for a large formation-flying mission is similar to that for a small connected-element one (e.g., cryogenics and detectors), with the addition of formationflying technology. The technology is now in hand to implement a probe-scale mission; starlight suppression has even been demonstrated to meet the requirements of a flagship mission. However, additional development of formation-flying technology is needed, particularly in-space testing of sensors and

  7. 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.

  8. Generalized Hampel Filters

    Science.gov (United States)

    Pearson, Ronald K.; Neuvo, Yrjö; Astola, Jaakko; Gabbouj, Moncef

    2016-12-01

    The standard median filter based on a symmetric moving window has only one tuning parameter: the window width. Despite this limitation, this filter has proven extremely useful and has motivated a number of extensions: weighted median filters, recursive median filters, and various cascade structures. The Hampel filter is a member of the class of decsion filters that replaces the central value in the data window with the median if it lies far enough from the median to be deemed an outlier. This filter depends on both the window width and an additional tuning parameter t, reducing to the median filter when t=0, so it may be regarded as another median filter extension. This paper adopts this view, defining and exploring the class of generalized Hampel filters obtained by applying the median filter extensions listed above: weighted Hampel filters, recursive Hampel filters, and their cascades. An important concept introduced here is that of an implosion sequence, a signal for which generalized Hampel filter performance is independent of the threshold parameter t. These sequences are important because the added flexibility of the generalized Hampel filters offers no practical advantage for implosion sequences. Partial characterization results are presented for these sequences, as are useful relationships between root sequences for generalized Hampel filters and their median-based counterparts. To illustrate the performance of this filter class, two examples are considered: one is simulation-based, providing a basis for quantitative evaluation of signal recovery performance as a function of t, while the other is a sequence of monthly Italian industrial production index values that exhibits glaring outliers.

  9. Multiscale Morphological Filtering for Analysis of Noisy and Complex Images

    Science.gov (United States)

    Kher, A.; Mitra, S.

    1993-01-01

    Images acquired with passive sensing techniques suffer from illumination variations and poor local contrasts that create major difficulties in interpretation and identification tasks. On the other hand, images acquired with active sensing techniques based on monochromatic illumination are degraded with speckle noise. Mathematical morphology offers elegant techniques to handle a wide range of image degradation problems. Unlike linear filters, morphological filters do not blur the edges and hence maintain higher image resolution. Their rich mathematical framework facilitates the design and analysis of these filters as well as their hardware implementation. Morphological filters are easier to implement and are more cost effective and efficient than several conventional linear filters. Morphological filters to remove speckle noise while maintaining high resolution and preserving thin image regions that are particularly vulnerable to speckle noise were developed and applied to SAR imagery. These filters used combination of linear (one-dimensional) structuring elements in different (typically four) orientations. Although this approach preserves more details than the simple morphological filters using two-dimensional structuring elements, the limited orientations of one-dimensional elements approximate the fine details of the region boundaries. A more robust filter designed recently overcomes the limitation of the fixed orientations. This filter uses a combination of concave and convex structuring elements. Morphological operators are also useful in extracting features from visible and infrared imagery. A multiresolution image pyramid obtained with successive filtering and a subsampling process aids in the removal of the illumination variations and enhances local contrasts. A morphology-based interpolation scheme was also introduced to reduce intensity discontinuities created in any morphological filtering task. The generality of morphological filtering techniques in

  10. MST Filterability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  11. Guided image filtering.

    Science.gov (United States)

    He, Kaiming; Sun, Jian; Tang, Xiaoou

    2013-06-01

    In this paper, we propose a novel explicit image filter called guided filter. Derived from a local linear model, the guided filter computes the filtering output by considering the content of a guidance image, which can be the input image itself or another different image. The guided filter can be used as an edge-preserving smoothing operator like the popular bilateral filter [1], but it has better behaviors near edges. The guided filter is also a more generic concept beyond smoothing: It can transfer the structures of the guidance image to the filtering output, enabling new filtering applications like dehazing and guided feathering. Moreover, the guided filter naturally has a fast and nonapproximate linear time algorithm, regardless of the kernel size and the intensity range. Currently, it is one of the fastest edge-preserving filters. Experiments show that the guided filter is both effective and efficient in a great variety of computer vision and computer graphics applications, including edge-aware smoothing, detail enhancement, HDR compression, image matting/feathering, dehazing, joint upsampling, etc.

  12. Analysis of an MCU HEPA filter

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-01-01

    A series of direct analyses on three portions (inlet, center, and outlet) of the High Efficiency Particulate Air (HEPA) filter material from the Modular Caustic-Side Solvent Extraction Unit (MCU) have been performed; this includes x-ray methods such as X-Ray Diffraction (XRD), Contained Scanning Electron Microscopy (CSEM) and X-Ray Fluorescence (XRF), as well as Fourier Transform InfraRed spectroscopy (FTIR). Additionally, two leaching studies (one with water, one with dichloromethane) have been performed on three portions (inlet, center, and outlet) of the HEPA filter material, with the leachates being analyzed by Inductively-coupled plasma emission spectroscopy (ICPES), Semi-Volatile Organic Analysis (SVOA) and gammascan. From the results of the analyses, SRNL feels that cesium-depleted solvent is being introduced into the HEPA filter. The most likely avenue for this is mechanical aerosolization of solvent, where the aerosol is then carried along an airstream into the HEPA filter. Once introduced into the HEPA filter media, the solvent wicks throughout the material, and migrates towards the outlet end. Once on the outlet end, continual drying could cause particulate flakes to exit the filter and travel farther down the airstream path.

  13. 2.5MV快沿电磁脉冲模拟器脉冲源故障状态模拟分析%Simulation Analysis for Fault States of 2.5 MV Electro-Magnetic Pulse Driver with Fast Rise Time

    Institute of Scientific and Technical Information of China (English)

    贾伟; 陈维青; 谢霖森; 张国伟; 李俊娜; 邱孟通

    2012-01-01

    利用电路模拟软件与实测波形,建立了2.5 MV快沿电磁脉冲(EMP)模拟脉冲源等效电路模型.通过在电路模型中模拟绝缘薄弱环节,如Marx输出端、中储电容、中储开关与峰化电容间支撑绝缘子、峰化电容等位置,设置等效滑闪电路的方法,对模拟器脉冲源可能出现的绝缘故障进行了模拟分析.将模拟器调试阶段出现的故障波形与模拟结果进行比对,二者符合良好.试验结果证明,根据模拟故障波形并结合试验中出现的巨大声响、电源跳闸等物理现象及后续输出电压降低等情况,可以实现模拟器滑闪故障的准确定位,从而保证故障的及时发现与快速排除,提高装置运行可靠性.%A circuit model of an electro-magnetic pulse (EMP) simulator driver with 2.5 MV rated voltage and fast rise time is established by the circuit simulation software and the measured output waveforms of the generator. An equivalent flash circuit is set up for the weaker insulation positions in the simulator, such as the output terminal of Marx, intermediate transfer switch, peaking capacitor, and intermediate capacitor. The modified model is used to analyze fault states of the driver, and the simulation results coincide well with the experimental data in debugging stage. The fault simulation and analysis combined with the physical phenomena - violent noise or breakdown of power supply appearing in the experiments and the subsequent output voltage reduction, can accurately locate the flash faults of the EMP simulator.

  14. Study of the thermo-electronic stability of LTS conductors and contribution to the study of the thermo-electric stability of HTS conductors. Novel techniques to simulate quench precursors in superconducting electro-magnets; Etude de la stabilite thermoelectronique des conducteurs supraconducteurs a basse temperature critique et contribution a l'etude de la stabilite thermoelectrique des supraconducteurs a haute temperature critique

    Energy Technology Data Exchange (ETDEWEB)

    Trillaud, F

    2005-09-01

    Most of this work deals with the development of new heater technology to simulate quench precursors in super-conducting electro-magnets. The carbon paste point heater and 2 alternative technologies have been used: induction coils and the diode laser. 2 main experimental setups with 2 different heaters have been used to study the stability of Cu/NbTi composite wires. The order of magnitude of the results obtained with the charged point heater and the diode laser is consistent. Our work covered both low critical temperature (LTS) conductors and high critical temperature (HTS) conductors. A large body of data has been gathered on quench energies and normal zone propagation velocities (NZPV). Concerning quench energy: LTS conductors appear largely more sensitive to heat disturbances than HTS conductors. NZPV enables one to define the criteria for which a magnet can be considered as self-protected. It is commonly assumed that, below 1 m/s, active protection is necessary to ensure safe quenches. This is the case for HTS conductors whose NZPV is of the order of a few centimeters per seconds, at most. However, the NZPVs of LTS conductors are above a few meters per seconds. While HTS conductors can suffer from local hot spots which diffuse slowly resulting in damaging overheating, LTS conductors spread the normal zone quickly enough owing to their good thermal conductivity to minimize local overheating. In addition, this gives enough time to dump the energy of the magnet. This work clears a new path to carry out accurate and reproducible experiment on superconductors. It demonstrates the powerfulness of diode laser technology for stability studies. Numerical simulations of the thermal behaviour of a Cu/NbTi multi-filament composite wire have been performed, they are based on a simplified transient liquid helium heat exchange model. This model appears to be not accurate enough to simulate the early time evolution of the voltage between the current sharing temperature and the

  15. Computer Aided Filter Design.

    Science.gov (United States)

    1987-12-01

    FIR filter can be described in the following. [Ref. 2] 1. FIR filters with exact linear phase can be easily designed. Linear phase filters are important...response for the four cases of linear phase filter , i.e., even or odd symmetry with an even or odd number of terms, can be written in the form: H (eJ ) = e...Ansari, The Design and Application of Optimal FIR Fractional Phase Filters , IEEE on Acoutics, Speech and Signal Processing, Vol. 2, 1987, pp.896-899. 77 14

  16. A unified Kalman filter

    Science.gov (United States)

    Stubberud, Allen R.

    2017-01-01

    When considering problems of linear sequential estimation, two versions of the Kalman filter, the continuous-time version and the discrete-time version, are often used. (A hybrid filter also exists.) In many applications in which the Kalman filter is used, the system to which the filter is applied is a linear continuous-time system, but the Kalman filter is implemented on a digital computer, a discrete-time device. The two general approaches for developing a discrete-time filter for implementation on a digital computer are: (1) approximate the continuous-time system by a discrete-time system (called discretization of the continuous-time system) and develop a filter for the discrete-time approximation; and (2) develop a continuous-time filter for the system and then discretize the continuous-time filter. Generally, the two discrete-time filters will be different, that is, it can be said that discretization and filter generation are not, in general, commutative operations. As a result, any relationship between the discrete-time and continuous-time versions of the filter for the same continuous-time system is often obfuscated. This is particularly true when an attempt is made to generate the continuous-time version of the Kalman filter through a simple limiting process (the sample period going to zero) applied to the discrete-time version. The correct result is, generally, not obtained. In a 1961 research report, Kalman showed that the continuous-time Kalman filter can be obtained from the discrete-time Kalman filter by taking limits as the sample period goes to zero if the white noise process for the continuous-time version is appropriately defined. Using this basic concept, a discrete-time Kalman filter can be developed for a continuous-time system as follows: (1) discretize the continuous-time system using Kalman's technique; and (2) develop a discrete-time Kalman filter for that discrete-time system. Kalman's results show that the discrete-time filter generated in

  17. Bias aware Kalman filters

    DEFF Research Database (Denmark)

    Drecourt, J.-P.; Madsen, H.; Rosbjerg, Dan

    2006-01-01

    . The colored noise filter formulation is extended to correct both time correlated and uncorrelated model error components. A more stable version of the separate filter without feedback is presented. The filters are implemented in an ensemble framework using Latin hypercube sampling. The techniques...... are illustrated on a simple one-dimensional groundwater problem. The results show that the presented filters outperform the standard Kalman filter and that the implementations with bias feedback work in more general conditions than the implementations without feedback. 2005 Elsevier Ltd. All rights reserved....

  18. Colorimetric calibration of coupled infrared simulation system

    Science.gov (United States)

    Zhang, Ying; Fei, Jindong; Gao, Yang; Du, Jian

    2015-10-01

    In order to test 2-color infrared sensors, a coupled infrared simulation system can generate radiometric outputs with wavelengths that range from less than 3 microns to more than 12 microns. There are two channels in the coupled simulation system, optically combined by a diachronic beam combiner. Each channel has an infrared blackbody, a filter, a diaphragm, and diaphragm-motors. The system is projected to the sensor under testing by a collimator. This makes it difficult to calibrate the system with only one-band thermal imager. Errors will be caused in the radiance levels measured by the narrow band thermal imager. This paper describes colorimetric temperature measurement techniques that have been developed to perform radiometric calibrations of these infrared simulation systems above. The calibration system consists of two infrared thermal imagers; one is operated at the wavelength range of MW-IR, and the other at the range of LW-IR.

  19. Optimal Sensor Decision Based on Particle Filter

    Institute of Scientific and Technical Information of China (English)

    XU Meng; WANG Hong-wei; HU Shi-qiang

    2006-01-01

    A novel infrared and radar synergistic tracking algorithm, which is based on the idea of closed loop control, and target's motion model identification and particle filter approach, was put forward. In order to improve the observability and filtering divergence of infrared search and tracking, the unscented Kalman filter algorithm that has stronger ability of non-linear approximation was adopted. The polynomial and least square method based on radar and IRST measurements to identify the parameters of the model was proposed, and a "pseudo sensor" was suggested to estimate the target position according to the identified model even if the radar is turned off. At last,the average Kullback-Leibler discrimination distance based on particle filter was used to measure the tracking performance, based on tracking performance and fuzzy stochastic decision, the idea of closed loop was used to retrieve the module parameter of "pseudo sensor". The experimental result indicates that the algorithm can not only limit the radar activity effectively but also keep the tracking accuracy of active/passive system well.

  20. Ceramic fiber filter technology

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  1. An Optimization of Pulsed ElectroMagnetic Fields Study

    Science.gov (United States)

    Goodwin, Thomas J.

    2006-01-01

    To date, in our research we have focused on the use of normal human neuronal progenitor (NHNP) cells because of their importance in human nervous system regeneration, development and maintenance, but we have developed 2-D and 3-D bioreactors that can accommodate any cell line. In this Project, we will include the use of tissues important for physiological regeneration: Human osteoblasts or chondrocytes, and vascular cells. Our initial results with the NHNP cells were quite startling using extremely low-level electromagnetic fields (5 microtesla at 10Hz; 6mA). The low-amplitude, rapidly time-varying electromagnetic fields exert a very potent effect on the proliferation, morphology, and gene expression of the cells in culture, both in standard 2-dimensional culture plates as well as cells organized into 3-dimensional tissue-like assemblies (TLAs) in a 3D bioreactor. We have replicated our preliminary results many, many times, have analyzed the gene expression using gene arrays (followed by Luminex analysis for protein production), and have monitored cell proliferation, orientation, morphology, and glucose metabolism, and we are confident that we have a stable and reliable model to study the control of high-level cellular processes by application of low-amplitude, time varying electromagnetic fields (TVEMF) (1, 2). In additional studies at the University of Michigan, we have been able to generate functional in vitro engineered mammalian skeletal muscle, and have employed nerve-muscle co-culture techniques to promote axonal sprouting. We believe that nearly all tissues, in particular, neural, are susceptible to the influences of low-level TVEMF.

  2. Non-Invasive Electro-Magnetic Field Sensor.

    Science.gov (United States)

    1986-01-01

    69 30 Fiber optic sensor’s response to a pulsed electric field . 74 31 Fiber optic electric field sensor’s response to an oscil- latory field...first test type involved a pulsed electric field . The applied voltage pulse was negative with a peak voltage of approxi- mately -24,000 volts and a

  3. Use of electro-magnetic damping for vibration control

    DEFF Research Database (Denmark)

    Stein, George Juraj; Darula, Radoslav; Sorokin, Sergey

    2012-01-01

    Vibration of machines is an unwanted phenomenon, and it is usually of interest to eliminate it. There are various means to be used in order to reach the goal, where the utilization of the electromagnet augmented by an external shunt circuit is analyzed in the paper. The magnetic force is used...... to introduce additional electromagnetic damping into vibrating mechanical system. The hysteretic losses and eddy currents are included in the model, to take into account more realistic dynamic behaviour of the system. The mathematical model of the controller is derived using lumped parameter approach...

  4. GEMPIC: Geometric ElectroMagnetic Particle-In-Cell Methods

    CERN Document Server

    Kraus, Michael; Morrison, Philip J; Sonnendrücker, Eric

    2016-01-01

    We present a novel framework for Finite Element Particle-in-Cell methods based on the discretization of the underlying Hamiltonian structure of the Vlasov-Maxwell system. We derive a semi-discrete Poisson bracket, which satisfies the Jacobi identity , and apply Hamiltonian splitting schemes for time integration. Techniques from Finite Element Exterior Calculus ensure conservation of the divergence of the magnetic field and Gauss' law as well as stability of the field solver. The resulting methods are gauge-invariant, feature exact charge conservation and show excellent long-time energy and momentum behavior.

  5. Pressure control valve using proportional electro-magnetic solenoid actuator

    Energy Technology Data Exchange (ETDEWEB)

    Yun, So Nam; Ham, Young Bog; Park, Pyoung Won [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2006-10-15

    This paper presents an experimental characteristics of electro-hydraulic proportional pressure control valve. In this study, poppet and valve body which are assembled into the proportional solenoid were designed and manufactured. The constant force characteristics of proportional solenoid actuator in the control region should be independent of the plunger position in order to be used to control the valve position in the fluid flow control system. The stroke-force characteristics of the proportional solenoid actuator is determined by the shape (or parameters) of the control cone. In this paper, steady state and transient characteristics of the solenoid actuator for electro-hydraulic proportional valve are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attraction force in the control region independently on the stroke position. The effects of the parameters such as control cone length, thickness and taper length are also discussed.

  6. Use of electro-magnetic damping for vibration control

    DEFF Research Database (Denmark)

    Stein, George Juraj; Darula, Radoslav; Sorokin, Sergey

    2012-01-01

    Vibration of machines is an unwanted phenomenon, and it is usually of interest to eliminate it. There are various means to be used in order to reach the goal, where the utilization of the electromagnet augmented by an external shunt circuit is analyzed in the paper. The magnetic force is used...... to introduce additional electromagnetic damping into vibrating mechanical system. The hysteretic losses and eddy currents are included in the model, to take into account more realistic dynamic behaviour of the system. The mathematical model of the controller is derived using lumped parameter approach...

  7. Micro-gravity Isolation using only Electro-magnetic Actuators

    DEFF Research Database (Denmark)

    Vinther, D.; Alminde, Lars; Bisgaard, Morten

    2004-01-01

    In this paper the design, construction and test of a free floating micro-gravity isolation platform to reduce the acceleration dose on zero gravity experiments on e.g. the International Space Station (ISS) is discussed. During the project a system is specified and constructed whereupon it is test...

  8. Phase II: Fire Extinguishment by Electro-Magnetic Fields

    Science.gov (United States)

    2012-06-19

    is an atmospheric pressure glow discharge (albeit at high currents). The reason is that the size of the cathode spot is not restricted. The result is... discharge . This can only happen in the form of a (non-self- sustaining) corona discharge . Such a current is too small to deplete the large 4 µF... discharges , in series. In this special case the corona discharge in the gap of the disk coil acts like a limiting ohmic resistor for the build-up of the

  9. Superconductors with low critical temperature for electro-magnets

    CERN Document Server

    Devred, Arnaud

    2002-01-01

    Among the superconductors with low critical temperature that are used to build magnets, NbTi has reached a development state that allows a massive production for big equipment of physics and an industrial production in the domain of medicine imaging. The material that might challenge the supremacy of NbTi is Nb sub 3 Sn but some technical difficulties have yet to be overcome. This report begins with a review of the different industrial processes used to produce superconducting wires based on the NbTi and Nb sub 3 Sn materials. The transition from the superconducting state to the resistive normal state is described for both materials, the magnetizing of multi-wire superconducting cables is also presented. The details the different patterns of wires in cables and proposes a formulary that allows the determination, in some simple cases,of energy losses that are generated in a superconducting cable by a variable magnetic field. (A.C.)

  10. A Far-Field Electro-Magnetic Tractor Beam Project

    Data.gov (United States)

    National Aeronautics and Space Administration — When the project began, our intention was to develop a more accurate model of the forces that could be obtained between experimentally demonstrate...

  11. Outer Wheel Uniformity of the ElectroMagnetic Endcap Calorimeter

    CERN Document Server

    Oliver, C

    2005-01-01

    An analysis of the test beam data for the uniformity of three ECC modules is presented. A non-uniformity of less than 0.6 per cent is obtained for the outer wheel of the three modules. The results are found to be independent of the signal reconstruction method used as long as the residuals are kept below 4 per cent.

  12. Electro-magnetic heating in viscous oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

    2008-10-15

    This paper discussed electromagnetic (EM) heating techniques for primary and secondary enhanced oil recovery (EOR) processes. Ohmic, induction, and formation resistive heating techniques were discussed. Issues related to energy equivalence and hardware requirements were reviewed. Challenges related to heat losses in vertical wellbores, well integrity, and galvanic corrosion were also outlined. A pair of 1500 foot horizontal wells in a heavy oil reservoir were then modelled in order to optimize EM recovery processes. DC current was used in a base case water flood run. Electrical conductivities were measured. The model was converted to a homogenous model in order to study injector and producer electrodes. The study showed that reservoir resistance was low, and most of the heating took place near the electrode area where electric lines diverged or converged. Results of the study suggested that EM heating in formations is not as efficient as steam-based processes. Accurate simulations of EM heating processes within reservoirs are difficult to obtain, as the amounts of estimated heat input are sensitive to grid refinement. It was concluded that hot spots in the EM electrodes have also caused failures in other field applications and studies. 11 refs., 12 figs.

  13. NOx Monitoring in Humid Exhaust Gas Using Non-Dispersive Infrared Spectroscopy

    DEFF Research Database (Denmark)

    Stolberg-Rohr, Thomine Kirstine

    filters in general, and temperature invariant filters in particular. This work has led to the derivation of the thermo-optical expansion coefficients of embedded PbTe and ZnSe thin films, frequently used in optical bandpass filters for the mid-infrared range. Knowledge of these coefficients allows...

  14. Three-zone pupil filters

    Science.gov (United States)

    Sheppard, Colin J. R.; Campos, Juan; Escalera, Juan C.; Ledesma, Silvia

    2008-07-01

    The performance of pupil filters consisting of three zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters.

  15. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications

    OpenAIRE

    Agishev, Ravil R.; Comerón Tejero, Adolfo

    2002-01-01

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal background-radiation ratio SBR at the photodetector input. The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effec...

  16. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications

    OpenAIRE

    Agishev, Ravil R.; Comerón Tejero, Adolfo

    2002-01-01

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal background-radiation ratio SBR at the photodetector input. The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effec...

  17. Small target detection using quantum genetic morphological filter

    Science.gov (United States)

    Deng, Lizhen; Zhu, Hu; Wei, Yantao; Lu, Guanmin; Wei, Yu

    2015-12-01

    Small target detection plays a crucial role in infrared warning and tracking systems. A background suppression method using morphological filter based on quantum genetic algorithm (QGMF) is presented to detect small targets in infrared image. Structure element of morphological filter is encoded and the best structure element is selected using quantum genetic algorithm. The optimized structure element is used for background suppression to detect small target. Experimental results demonstrate that QGMF has good performance in clutter suppression, and obtains higher signal-to-clutter ratio gain (SCRG) and background suppression factor (BSF) than the one using the fixed structure element with the same size.

  18. Infrared retina

    Science.gov (United States)

    Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong

    2011-12-06

    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  19. 金属滤筒吸收-红外分光光度法测定淬火油烟的浓度%Determination of Quenching Oil Fumes Concentration by Metal Filter Cylinder-Absorption and Infrared Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    衡兆祥

    2014-01-01

    Quenching oil fume in the heat treatment process was collected with automatic tracking method. Fiter which collected oil fumes was placed in teflon sleeve with lid. Ultrasonic cleaning was carried out in lab, cleaning liquid was moved in the volumetric flask, then oil content was determined by infrared spectrophotometry. In the range of 0.0-100 mg/L, standard oil concentration detection value was linear with standard value, the correlation coefficient r=0.999 6. The recovery was 85.9%-106.2%, the relative standard deviation was 1.05%-1.92%(n=6), and the detection limit was 0.25 mg/m3. The method is sensitive and accurate, it can be used for testing the effect of enterprises oil fume control, and environmental protection department supervision and monitoring in enterprises fume emission concentration.%用自动跟踪法采集热处理工艺中淬火油烟,将收集油烟的滤芯置于带盖的聚四氟乙烯套筒,用四氯化碳作溶剂进行超声清洗,清洗液移入容量瓶中定容,用红外分光光度法测定油烟含量。在0.0~100 mg/L范围内,标准淬火油质量浓度实测值与与标准值呈良好的线性,相关系数r=0.9996。加标回收率为85.9%~106.2%,相对标准偏差为1.05%~1.92%(n=6),检出限为0.25 mg/m3。该方法灵敏度高,测定结果准确,可用于企业油烟治理效果的验收检测及环保部门对企业淬火油烟排放浓度的监督监测。

  20. Generic Kalman Filter Software

    Science.gov (United States)

    Lisano, Michael E., II; Crues, Edwin Z.

    2005-01-01

    The Generic Kalman Filter (GKF) software provides a standard basis for the development of application-specific Kalman-filter programs. Historically, Kalman filters have been implemented by customized programs that must be written, coded, and debugged anew for each unique application, then tested and tuned with simulated or actual measurement data. Total development times for typical Kalman-filter application programs have ranged from months to weeks. The GKF software can simplify the development process and reduce the development time by eliminating the need to re-create the fundamental implementation of the Kalman filter for each new application. The GKF software is written in the ANSI C programming language. It contains a generic Kalman-filter-development directory that, in turn, contains a code for a generic Kalman filter function; more specifically, it contains a generically designed and generically coded implementation of linear, linearized, and extended Kalman filtering algorithms, including algorithms for state- and covariance-update and -propagation functions. The mathematical theory that underlies the algorithms is well known and has been reported extensively in the open technical literature. Also contained in the directory are a header file that defines generic Kalman-filter data structures and prototype functions and template versions of application-specific subfunction and calling navigation/estimation routine code and headers. Once the user has provided a calling routine and the required application-specific subfunctions, the application-specific Kalman-filter software can be compiled and executed immediately. During execution, the generic Kalman-filter function is called from a higher-level navigation or estimation routine that preprocesses measurement data and post-processes output data. The generic Kalman-filter function uses the aforementioned data structures and five implementation- specific subfunctions, which have been developed by the user on

  1. Concentric Split Flow Filter

    Science.gov (United States)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  2. Crux vena cava filter.

    Science.gov (United States)

    Murphy, Erin H; Johnson, Eric D; Kopchok, George E; Fogarty, Thomas J; Arko, Frank R

    2009-09-01

    Inferior vena cava filters are widely accepted for pulmonary embolic prophylaxis in high-risk patients with contraindications to anticoagulation. While long-term complications have been associated with permanent filters, retrievable filters are now available and have resulted in the rapid expansion of this technology. Nonetheless, complications are still reported with optional filters. Furthermore, device tilting and thrombus load may prevent retrieval in up to 30% of patients, thereby eliminating the benefits of this technology. The Crux vena cava filter is a novel, self-centering, low-profile filter that is designed for ease of delivery, retrievability and improved efficacy while limiting fatigue-related device complications. This device has been proven safe and user-friendly in an ovine model and has recently been implanted in human subjects.

  3. CrowdFilter

    DEFF Research Database (Denmark)

    Mortensen, Michael Lind; Wallace, Byron C.; Kraska, Tim

    for complex multi-criteria search problems through crowdsourcing. The CrowdFilter system is capable of supporting both criteria-level labels and n-gram rationales, capturing the human decision making process behind each filtering choice. Using the data provided through CrowdFilter we also introduce a novel......Multi-criteria filtering of mixed open/closed-world data is a time-consuming task, requiring significant manual effort when latent open-world attributes are present. In this work we introduce a novel open-world filtering framework CrowdFilter, enabling automatic UI generation and label elicitation...... multi-criteria active learning method; capable of incorporating labels and n-gram rationales per inclusion criteria, and thus capable of determining both clear includes/excludes, as well as complex borderline cases. By incorporating the active learning approach into the elicitation process of Crowd...

  4. Conservative Noise Filters

    Directory of Open Access Journals (Sweden)

    Mona M.Jamjoom

    2016-05-01

    Full Text Available Noisy training data have a huge negative impact on machine learning algorithms. Noise-filtering algorithms have been proposed to eliminate such noisy instances. In this work, we empirically show that the most popular noise-filtering algorithms have a large False Positive (FP error rate. In other words, these noise filters mistakenly identify genuine instances as outliers and eliminate them. Therefore, we propose more conservative outlier identification criteria that improve the FP error rate and, thus, the performance of the noise filters. With the new filter, an instance is eliminated if and only if it is misclassified by a mutual decision of Naïve Bayesian (NB classifier and the original filtering criteria being used. The number of genuine instances that are incorrectly eliminated is reduced as a result, thereby improving the classification accuracy.

  5. Hybrid Filter Membrane

    Science.gov (United States)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  6. Oriented Fiber Filter Media

    Directory of Open Access Journals (Sweden)

    R. Bharadwaj

    2008-06-01

    Full Text Available Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a thick layered media can improve performance by about 40%. The results also show the improved performance is not monotonically correlated to the average fiber angle of the medium.

  7. Fundamentals of Stochastic Filtering

    CERN Document Server

    Crisan, Dan

    2008-01-01

    The objective of stochastic filtering is to determine the best estimate for the state of a stochastic dynamical system from partial observations. The solution of this problem in the linear case is the well known Kalman-Bucy filter which has found widespread practical application. The purpose of this book is to provide a rigorous mathematical treatment of the non-linear stochastic filtering problem using modern methods. Particular emphasis is placed on the theoretical analysis of numerical methods for the solution of the filtering problem via particle methods. The book should provide sufficient

  8. Filter holder and gasket assembly for candle or tube filters

    Science.gov (United States)

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

    1999-03-02

    A filter holder and gasket assembly for holding a candle filter element within a hot gas cleanup system pressure vessel. The filter holder and gasket assembly includes a filter housing, an annular spacer ring securely attached within the filter housing, a gasket sock, a top gasket, a middle gasket and a cast nut.

  9. DETECTION OF VESSELS IN HUMAN FOREARMS USING 2D MATCHED FILTERING

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2008-01-01

    Detektering af blodårer ved brug af 2D matched filtering i billeder af underarmen. Billederne er produseret ved brug af nær infrarødt lys.......Detektering af blodårer ved brug af 2D matched filtering i billeder af underarmen. Billederne er produseret ved brug af nær infrarødt lys....

  10. [Continuum based fast Fourier transform processing of infrared spectrum].

    Science.gov (United States)

    Liu, Qing-Jie; Lin, Qi-Zhong; Wang, Qin-Jun; Li, Hui; Li, Shuai

    2009-12-01

    To recognize ground objects with infrared spectrum, high frequency noise removing is one of the most important phases in spectrum feature analysis and extraction. A new method for infrared spectrum preprocessing was given combining spectrum continuum processing and Fast Fourier Transform (CFFT). Continuum was firstly removed from the noise polluted infrared spectrum to standardize hyper-spectra. Then the spectrum was transformed into frequency domain (FD) with fast Fourier transform (FFT), separating noise information from target information After noise eliminating from useful information with a low-pass filter, the filtered FD spectrum was transformed into time domain (TD) with fast Fourier inverse transform. Finally the continuum was recovered to the spectrum, and the filtered infrared spectrum was achieved. Experiment was performed for chlorite spectrum in USGS polluted with two kinds of simulated white noise to validate the filtering ability of CFFT by contrast with cubic function of five point (CFFP) in time domain and traditional FFT in frequency domain. A circle of CFFP has limited filtering effect, so it should work much with more circles and consume more time to achieve better filtering result. As for conventional FFT, Gibbs phenomenon has great effect on preprocessing result at edge bands because of special character of rock or mineral spectra, while works well at middle bands. Mean squared error of CFFT is 0. 000 012 336 with cut-off frequency of 150, while that of FFT and CFFP is 0. 000 061 074 with cut-off frequency of 150 and 0.000 022 963 with 150 working circles respectively. Besides the filtering result of CFFT can be improved by adjusting the filter cut-off frequency, and has little effect on working time. The CFFT method overcomes the Gibbs problem of FFT in spectrum filtering, and can be more convenient, dependable, and effective than traditional TD filter methods.

  11. Infrared optical coatings in SITP

    Institute of Scientific and Technical Information of China (English)

    LIU Ding-quan; ZHANG Feng-shan

    2005-01-01

    Infrared optical coatings in SITP (Shanghai Institute of Technical Physics) mainly cover the spectrum range from 0.7 μm to 15 μm, and visible and near-UV range are also been included. The coatings are mainly used for metal-reflectance mirrors, Anti-reflection(AR) lens and windows, filters, and dichroic beam splitters. Coatings passed some dependability tests. These optical coated devices usually consist in a remote observing instrument. Most coating materials are commercial products. And one kind of special material PbTe is made by ourselves. Some main results of our research department are reported.

  12. A Novel Multiple Component Gas Infrared Ray Sensor

    Institute of Scientific and Technical Information of China (English)

    张永怀; 周金林; 林继鹏; 刘君华

    2003-01-01

    In this paper, The principle, structure and practical application of a novel multiple component gas infrared ray sensor are discussed. The optical gas sensor, which has infrared radiation impulses input and electric single output, is composed of narrow band light filter, optical taper and pyroelectric detector array. An infrared gas analyzer with multiple component gas tested synchronously consists of the sensor, single middle infrared source, single gas cell and computer data acquire system. As compared with sensor in other infrared gas analyzer, it has many merits such as novel structure, strong anti-oscillate performance and low cost. Different gas in different measurement area can be analyzed quantitatively by replacing optical filter module easily.

  13. Images and Spectral Performance of WFC3 Interference Filters

    Science.gov (United States)

    Quijada, Manuel A.; Boucarut, R.; Telfer, R.; Baggett, S.; Quijano, J. Kim; Allen, George; Arsenovic, Peter

    2006-01-01

    The Wide Field Camera 3 (WFC3) is a panchromatic imager that will be deployed in the Hubble Space Telescope (HST). The mission of the WFC3 is to enhance HST1s imaging capability in the ultraviolet, visible and near-infrared spectral regions. Together with a wavelength coverage spanning 2000A to 1.7 micron, the WFC3 high sensitivity, high spatial resolution, and large field-of-view provide the astronomer with an unprecedented set of tools for exploring all types of exciting astrophysical terrain and for addressing many key questions in astronomy today. The filter compliment, which includes broad, medium, and narrow band filters, naturally reflects the diversity of astronomical programs to be targeted with WFC3. The WFC3 holds 61 UVIS filters elements, 14 IR filters, and 3 dispersive elements. During ground testing, the majority of the UVIS filters were found to exhibit excellent performance consistent with or exceeding expectations; however, a subset of filters showed considerable ghost images; some with relative intensity as high as 10-15%. Replacement filters with band-defining coatings that substantially reduce these ghost images were designed and procured. A state-of-the-art characterization setup was developed to measured the intensity of ghost images, focal shift, wedge direction , transmitted uniformity and surface feature of filters that could effect uniform flat field images. We will report on this new filter characterization methods, as well as the spectral performance measurements of the in-band transmittance and blocking.

  14. Fast Anisotropic Gauss Filtering

    NARCIS (Netherlands)

    Geusebroek, J.M.; Smeulders, A.W.M.; van de Weijer, J.; Heyden, A.; Sparr, G.; Nielsen, M.; Johansen, P.

    2002-01-01

    We derive the decomposition of the anisotropic Gaussian in a one dimensional Gauss filter in the x-direction followed by a one dimensional filter in a non-orthogonal direction phi. So also the anisotropic Gaussian can be decomposed by dimension. This appears to be extremely efficient from a computin

  15. Multilevel ensemble Kalman filter

    KAUST Repository

    Chernov, Alexey

    2016-01-06

    This work embeds a multilevel Monte Carlo (MLMC) sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF). In terms of computational cost vs. approximation error the asymptotic performance of the multilevel ensemble Kalman filter (MLEnKF) is superior to the EnKF s.

  16. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Wells, George; Beaton, Dorcas E; Tugwell, Peter;

    2014-01-01

    The "Discrimination" part of the OMERACT Filter asks whether a measure discriminates between situations that are of interest. "Feasibility" in the OMERACT Filter encompasses the practical considerations of using an instrument, including its ease of use, time to complete, monetary costs, and inter...

  17. Vena cava filter; Vena-cava-Filter

    Energy Technology Data Exchange (ETDEWEB)

    Helmberger, T. [Klinikum Bogenhausen, Institut fuer Diagnostische und Interventionelle Radiologie und Nuklearmedizin, Muenchen (Germany)

    2007-05-15

    Fulminant pulmonary embolism is one of the major causes of death in the Western World. In most cases, deep leg and pelvic venous thrombosis are the cause. If an anticoagulant/thrombotic therapy is no longer possible or ineffective, a vena cava filter implant may be indicated if an embolism is threatening. Implantation of the filter is a simple and safe intervention. Nevertheless, it is necessary to take into consideration that the data base for determining the indications for this treatment are very limited. Currently, a reduction in the risk of thromboembolism with the use of filters of about 30%, of recurrences of almost 5% and fatal pulmonary embolism of 1% has been reported, with a risk of up to 20% of filter induced vena cava thrombosis. (orig.) [German] Die fulminante Lungenembolie zaehlt zu den Haupttodesursachen in der westlichen Welt. In der Mehrzahl der Faelle sind tiefe Bein- und Beckenvenenthrombosen ursaechlich verantwortlich. Ist eine antikoagulative/-thrombotische Therapie nicht (mehr) moeglich oder unwirksam, kann bei drohender Emboliegefahr die Vena-cava-Filterimplantation indiziert sein. Die Filterimplantation ist eine einfache und sehr sichere Intervention. Dennoch muss bei der Indikationsstellung beruecksichtigt werden, dass die Datenlage zur Wirksamkeit sehr limitiert ist. So wird aktuell ueber eine Reduktion des Thrombembolierisikos um 30% bei Embolierezidiven von knapp 5% und fatalen Lungenembolien von 1% unter Filterprophylaxe berichtet, bei einem Risiko von bis zu 20% fuer die filterinduzierte Vena-cava-Thrombose. (orig.)

  18. Weighted guided image filtering.

    Science.gov (United States)

    Li, Zhengguo; Zheng, Jinghong; Zhu, Zijian; Yao, Wei; Wu, Shiqian

    2015-01-01

    It is known that local filtering-based edge preserving smoothing techniques suffer from halo artifacts. In this paper, a weighted guided image filter (WGIF) is introduced by incorporating an edge-aware weighting into an existing guided image filter (GIF) to address the problem. The WGIF inherits advantages of both global and local smoothing filters in the sense that: 1) the complexity of the WGIF is O(N) for an image with N pixels, which is same as the GIF and 2) the WGIF can avoid halo artifacts like the existing global smoothing filters. The WGIF is applied for single image detail enhancement, single image haze removal, and fusion of differently exposed images. Experimental results show that the resultant algorithms produce images with better visual quality and at the same time halo artifacts can be reduced/avoided from appearing in the final images with negligible increment on running times.

  19. Robustifying Vector Median Filter

    Directory of Open Access Journals (Sweden)

    Valentín Gregori

    2011-08-01

    Full Text Available This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use of complimentary information from componentwise analysis allows to build robust outputs from more reliable components. The correlation among the colour channels is taken into account in the processing and, as a result, a more robust filter able to process colour images without introducing colour artifacts is obtained. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter. Objective measures demonstrate the goodness of the achieved improvement.

  20. Filter cake breaker systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  1. Naive Bayesian for Email Filtering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The paper presents a method of email filter based on Naive Bayesian theory that can effectively filter junk mail and illegal mail. Furthermore, the keys of implementation are discussed in detail. The filtering model is obtained from training set of email. The filtering can be done without the users specification of filtering rules.

  2. Infrared heating

    Science.gov (United States)

    1983-11-01

    The transfer of energy by radiation whose limits lie between 1 mm and 400 mm is indicated. The radiation used lies practically completely in the infrared region. Its use therefore depends on the thermal radiation laws (black body or integral receiver laws). These laws were derived mathematically in accordance with the properties of an ideal body, the so-called ""integral receiver'' (formerly black body). According to definition this integral receiver has the property of absorbing completely all incident electromagnetic radiation. From these the following laws were deduced: (1) All bodies with a temperature above absolute zero emit a radiation. (2) The energy emitted by the integral receiver is proportional to the 4th power of the absolute temperature. (3) The emission theoretically comprizes the whole radiation. (4) The radiation comprizing the emission spectrum does not transport the same amount of energy at every wavelength.

  3. Derivative free filtering using Kalmtool

    DEFF Research Database (Denmark)

    Bayramoglu, Enis; Hansen, Søren; Ravn, Ole;

    2010-01-01

    In this paper we present a toolbox enabling easy evaluation and comparison of different filtering algorithms. The toolbox is called Kalmtool 4 and is a set of MATLAB tools for state estimation of nonlinear systems. The toolbox contains functions for extended Kalman filtering as well as for DD1...... filter and the DD2 filter. It also contains functions for Unscented Kalman filters as well as several versions of particle filters. The toolbox requires MATLAB version 7, but no additional toolboxes are required....

  4. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  5. EMI filter design

    CERN Document Server

    Ozenbaugh, Richard Lee

    2011-01-01

    With today's electrical and electronics systems requiring increased levels of performance and reliability, the design of robust EMI filters plays a critical role in EMC compliance. Using a mix of practical methods and theoretical analysis, EMI Filter Design, Third Edition presents both a hands-on and academic approach to the design of EMI filters and the selection of components values. The design approaches covered include matrix methods using table data and the use of Fourier analysis, Laplace transforms, and transfer function realization of LC structures. This edition has been fully revised

  6. Randomized Filtering Algorithms

    DEFF Research Database (Denmark)

    Katriel, Irit; Van Hentenryck, Pascal

    2008-01-01

    of AllDifferent and is generalization, the Global Cardinality Constraint. The first delayed filtering scheme is a Monte Carlo algorithm: its running time is superior, in the worst case, to that of enforcing are consistency after every domain event, while its filtering effectiveness is analyzed...... in the expected sense. The second scheme is a Las Vegas algorithm using filtering triggers: Its effectiveness is the same as enforcing are consistency after every domain event, while in the expected case it is faster by a factor of m/n, where n and m are, respectively, the number of nodes and edges...

  7. Air Filter Simulation by Geodict

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-peng; Kitai Kim; Changhwan Lee; Jooyong Kim

    2006-01-01

    In this paper, we discussed the relationship of filter efficiency and pressure drop with the porosity, fiber diameter and filter thickness by Geodict. We found that filter efficiency will increase when filter porosity and fiber diameter decreasing or filter thickness increasing. And the pressure drop has a linear relationship with filter thickness and non-linear relationship with filter porosity and fiber diameter. We also compared the simulation results with the real test results by TSI 3160. Although there are some differences, I think Geodict can be used to predict filter efficiency and pressure drop.

  8. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Kirwan, John R; Boers, Maarten; Hewlett, Sarah

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter presupposes an explicit framework for identifying the relevant core outcomes that are......OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter presupposes an explicit framework for identifying the relevant core outcomes...... that are universal to all studies of the effects of intervention effects. There is no published outline for instrument choice or development that is aimed at measuring outcome, was derived from broad consensus over its underlying philosophy, or includes a structured and documented critique. Therefore, a new proposal...

  9. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    D'Agostino, Maria-Antonietta; Boers, Maarten; Kirwan, John

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides a framework for the validation of outcome measures for use in rheumatology clinical research. However, imaging and biochemical measures may face additional validation challenges because of their technical nature. The Imagin...

  10. Paul Rodgersi filter Kohilas

    Index Scriptorium Estoniae

    2000-01-01

    28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ئ Marko Heinmäe, Hendrik Karm.

  11. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Tugwell, Peter; Boers, Maarten; D'Agostino, Maria-Antonietta

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter requires that criteria be met to demonstrate that the outcome instrument meets...... the criteria for content, face, and construct validity. METHODS: Discussion groups critically reviewed a variety of ways in which case studies of current OMERACT Working Groups complied with the Truth component of the Filter and what issues remained to be resolved. RESULTS: The case studies showed...... that there is broad agreement on criteria for meeting the Truth criteria through demonstration of content, face, and construct validity; however, several issues were identified that the Filter Working Group will need to address. CONCLUSION: These issues will require resolution to reach consensus on how Truth...

  12. Paul Rodgersi filter Kohilas

    Index Scriptorium Estoniae

    2000-01-01

    28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ئ Marko Heinmäe, Hendrik Karm.

  13. HEPA air filter (image)

    Science.gov (United States)

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  14. Perspectives on Nonlinear Filtering

    KAUST Repository

    Law, Kody

    2015-01-07

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

  15. Cryogenic coaxial microwave filters

    CERN Document Server

    Tancredi, G; Meeson, P J

    2014-01-01

    At millikelvin temperatures the careful filtering of electromagnetic radiation, especially in the microwave regime, is critical for controlling the electromagnetic environment for experiments in fields such as solid-state quantum information processing and quantum metrology. We present a design for a filter consisting of small diameter dissipative coaxial cables that is straightforward to construct and provides a quantitatively predictable attenuation spectrum. We describe the fabrication process and demonstrate that the performance of the filters is in good agreement with theoretical modelling. We further perform an indicative test of the performance of the filters by making current-voltage measurements of small, underdamped Josephson Junctions at 15 mK and we present the results.

  16. The filter-loading effect by ambient aerosols in filter absorption photometers depends on the coating of the sampled particles

    Science.gov (United States)

    Drinovec, Luka; Gregorič, Asta; Zotter, Peter; Wolf, Robert; Bruns, Emily Anne; Prévôt, André S. H.; Petit, Jean-Eudes; Favez, Olivier; Sciare, Jean; Arnold, Ian J.; Chakrabarty, Rajan K.; Moosmüller, Hans; Filep, Agnes; Močnik, Griša

    2017-03-01

    Black carbon is a primary aerosol tracer for high-temperature combustion emissions and can be used to characterize the time evolution of its sources. It is correlated with a decrease in public health and contributes to atmospheric warming. Black carbon measurements are usually conducted with absorption filter photometers, which are prone to several artifacts, including the filter-loading effect - a saturation of the instrumental response due to the accumulation of the sample in the filter matrix. In this paper, we investigate the hypothesis that this filter-loading effect depends on the optical properties of particles present in the filter matrix, especially on the black carbon particle coating. We conducted field campaigns in contrasting environments to determine the influence of source characteristics, particle age and coating on the magnitude of the filter-loading effect. High-time-resolution measurements of the filter-loading parameter in filter absorption photometers show daily and seasonal variations of the effect. The variation is most pronounced in the near-infrared region, where the black carbon mass concentration is determined. During winter, the filter-loading parameter value increases with the absorption Ångström exponent. It is suggested that this effect is related to the size of the black carbon particle core as the wood burning (with higher values of the absorption Ångström exponent) produces soot particles with larger diameters. A reduction of the filter-loading effect is correlated with the availability of the coating material. As the coating of ambient aerosols is reduced or removed, the filter-loading parameter increases. Coatings composed of ammonium sulfate and secondary organics seem to be responsible for the variation of the loading effect. The potential source contribution function analysis shows that high values of the filter-loading parameter in the infrared are indicative of local pollution, whereas low values of the filter

  17. The Endogenous Kalman Filter

    OpenAIRE

    Brad Baxter; Liam Graham; Stephen Wright

    2007-01-01

    We relax the assumption of full information that underlies most dynamic general equilibrium models, and instead assume agents optimally form estimates of the states from an incomplete information set. We derive a version of the Kalman filter that is endogenous to agents' optimising decisions, and state conditions for its convergence. We show the (restrictive) conditions under which the endogenous Kalman filter will at least asymptotically reveal the true states. In general we show that incomp...

  18. Inorganic UV filters

    Directory of Open Access Journals (Sweden)

    Eloísa Berbel Manaia

    2013-06-01

    Full Text Available Nowadays, concern over skin cancer has been growing more and more, especially in tropical countries where the incidence of UVA/B radiation is higher. The correct use of sunscreen is the most efficient way to prevent the development of this disease. The ingredients of sunscreen can be organic and/or inorganic sun filters. Inorganic filters present some advantages over organic filters, such as photostability, non-irritability and broad spectrum protection. Nevertheless, inorganic filters have a whitening effect in sunscreen formulations owing to the high refractive index, decreasing their esthetic appeal. Many techniques have been developed to overcome this problem and among them, the use of nanotechnology stands out. The estimated amount of nanomaterial in use must increase from 2000 tons in 2004 to a projected 58000 tons in 2020. In this context, this article aims to analyze critically both the different features of the production of inorganic filters (synthesis routes proposed in recent years and the permeability, the safety and other characteristics of the new generation of inorganic filters.

  19. Contactor/filter improvements

    Science.gov (United States)

    Stelman, David

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  20. Mining dust filter. Bergbaustaubfilter

    Energy Technology Data Exchange (ETDEWEB)

    Igelbuescher, H.; Hoelter, H.

    1988-12-28

    A dust filter for application underground, whose casing is designed as a transportable unit combinable with further casings and fitted with removable filter pockets. These filter pockets have a frame which seals towards the casing and with the lattices on which the filter cloth is stretched and with spacers holding the said lattices at a distance. Each casing as such has inspection ports that are operationable optionally on either side, and clean and crude gas channels on its upper side. The ends of these channels have coupleable head pieces, so that connection is made easy when casings are arranged in a line. Each crude gas channel is connected to the inside of the casing by means of perforations in the floor of said channel, whereas the clean gas channel, for its part, is in connection with the inside of the casing by means of a channel on the head side of the casing. It is thus possible to create a dust filter having practically any desired output by arranging individual modules in line, in which connection each individual module is reliably transportable on the facilities available below ground, as pre-fabricated above ground. Stable support of the sides of the filter cloths is ensured by the lattice that consists of reciprocally cranked longitudinal and transverse wires. 10 figs.

  1. Adaptive Denoising and Equalization of Infrared Wireless CDMA System

    Directory of Open Access Journals (Sweden)

    Fernando Xavier N.

    2005-01-01

    Full Text Available Infrared has abundant, unregulated bandwidth enabling rapid deployment at low cost. However, safety limits on power emission levels (IEC825, large noise due to ambient lighting, and multipath dispersion remain as hurdles in diffused indoor environments. Especially, the high-frequency periodic interference produced by fluorescent lights is a major concern. Spread spectrum techniques enable low-power operation and noise rejection, at the expense of large processing gain. In this paper, we quantify the noise received and propose an adaptive FIR filter to jointly cancel the multipath dispersion and the fluorescent light noise in an infrared CDMA system. From analytical and simulation results, the adaptive filter significantly enhances the noise rejection capability of the CDMA system and tracks well the quasistationary indoor wireless channel. Our results show tenfold improvement in the BER for a given SNR and processing gain due to the adaptive filter. The filter also performs well in the multiuser environment.

  2. Human body region enhancement method based on Kinect infrared imaging

    Science.gov (United States)

    Yang, Lei; Fan, Yubo; Song, Xiaowei; Cai, Wenjing

    2016-10-01

    To effectively improve the low contrast of human body region in the infrared images, a combing method of several enhancement methods is utilized to enhance the human body region. Firstly, for the infrared images acquired by Kinect, in order to improve the overall contrast of the infrared images, an Optimal Contrast-Tone Mapping (OCTM) method with multi-iterations is applied to balance the contrast of low-luminosity infrared images. Secondly, to enhance the human body region better, a Level Set algorithm is employed to improve the contour edges of human body region. Finally, to further improve the human body region in infrared images, Laplacian Pyramid decomposition is adopted to enhance the contour-improved human body region. Meanwhile, the background area without human body region is processed by bilateral filtering to improve the overall effect. With theoretical analysis and experimental verification, the results show that the proposed method could effectively enhance the human body region of such infrared images.

  3. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications.

    Science.gov (United States)

    Agishev, Ravil R; Comeron, Adolfo

    2002-12-20

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal/background-radiation ratio (SBR) at the photodetector input The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effective protection against sky background radiation for groundbased biaxial lidars is the modifying of their angular field according to a spatial-angular filtering efficiency criterion. Some effective approaches to achieve a high filtering efficiency for the receiving system optimization are discussed.

  4. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications

    Science.gov (United States)

    Agishev, Ravil R.; Comeron, Adolfo

    2002-12-01

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal/background-radiation ratio (SBR) at the photodetector input. The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effective protection against sky background radiation for groundbased biaxial lidars is the modifying of their angular field according to a spatial-angular filtering efficiency criterion. Some effective approaches to achieve a high filtering efficiency for the receiving system optimization are discussed.

  5. Fractional vortex dipole phase filter

    Science.gov (United States)

    Sharma, Manoj Kumar; Joseph, Joby; Senthilkumaran, Paramasivam

    2014-10-01

    In spatial filtering experiments, the use of vortex phase filters plays an important role in realizing isotropic edge enhancement. In this paper, we report the use of a vortex dipole phase filter in spatial filtering. A dipole made of fractional vortices is used, and its filtering characteristics are studied. It is observed that the filter performance can be tuned by varying the distance of separation between the vortices of the dipole to achieve better contrast and output noise suppression, and when this distance tends to infinity, the filter performs like a 1-D Hilbert mask. Experimental and simulation results are presented.

  6. Choosing and using astronomical filters

    CERN Document Server

    Griffiths, Martin

    2014-01-01

    As a casual read through any of the major amateur astronomical magazines will demonstrate, there are filters available for all aspects of optical astronomy. This book provides a ready resource on the use of the following filters, among others, for observational astronomy or for imaging: Light pollution filters Planetary filters Solar filters Neutral density filters for Moon observation Deep-sky filters, for such objects as galaxies, nebulae and more Deep-sky objects can be imaged in much greater detail than was possible many years ago. Amateur astronomers can take

  7. An IIR median hybrid filter

    Science.gov (United States)

    Bauer, Peter H.; Sartori, Michael A.; Bryden, Timothy M.

    1992-01-01

    A new class of nonlinear filters, the so-called class of multidirectional infinite impulse response median hybrid filters, is presented and analyzed. The input signal is processed twice using a linear shift-invariant infinite impulse response filtering module: once with normal causality and a second time with inverted causality. The final output of the MIMH filter is the median of the two-directional outputs and the original input signal. Thus, the MIMH filter is a concatenation of linear filtering and nonlinear filtering (a median filtering module). Because of this unique scheme, the MIMH filter possesses many desirable properties which are both proven and analyzed (including impulse removal, step preservation, and noise suppression). A comparison to other existing median type filters is also provided.

  8. Two-zone pupil filters

    Science.gov (United States)

    Sheppard, Colin J. R.; Campos, Juan; Escalera, Juan C.; Ledesma, Silvia

    2008-03-01

    The performance of pupil filters consisting of two zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified and optimized. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters. The first of these minimizes the relative power in the outer rings for a given axial resolution, the second maximizes the Strehl ratio for a given transverse resolution, and the third minimizes the relative power in the outer rings for a given transverse resolution. Complex filters can give an axially shifted maximum in intensity: the performance parameters calculated relative to the true focus are investigated for some different classes of filter, but filters with phase change not equal to π are found to give inferior performance to the real value filters.

  9. Remotely serviced filter and housing

    Science.gov (United States)

    Ross, M.J.; Zaladonis, L.A.

    1987-07-22

    A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station. 6 figs.

  10. Nanotechnology Infrared Optics for Astronomy Missions

    Science.gov (United States)

    Smith, Howard A.; Frogel, Jay (Technical Monitor)

    2003-01-01

    The program "Nanotechnology Infrared Optics for Astronomy Missions" will design and develop new, nanotechnology techniques for infrared optical devices suitable for use in NASA space missions. The proposal combines expertise from the Smithsonian Astrophysical Observatory, the Naval Research Laboratory, the Goddard Space Flight Center, and the Physics Department at the Queen Mary and Westfield College in London, now relocated to the University of Cardiff, Cardiff, Wales. The method uses individually tailored metal grids and layered stacks of metal mesh grids, both inductive (freestanding) and capacitive (substrate-mounted), to produce various kinds of filters. The program has the following goals: 1) Model FIR filter properties using electric-circuit analogs and near-field, EM diffraction calculations. 2) Prototype fabrication of meshes on various substrates, with various materials, and of various dimensions. 3) Test filter prototypes and iterate with the modeling programs. 4) Travel to related sites, including trips to Washington, D.C. (location of NRL and GSFC), London (location of QMW), Cardiff, Wales, and Rome (location of ISO PMS project headquarters). 5) Produce ancillary science, including both publication of testing on mesh performance and infrared astronomical science.

  11. Development of low optical cross talk filters for VIIRS (JPSS)

    Science.gov (United States)

    Murgai, Vijay; Hendry, Derek; Downing, Kevin; Carbone, David; Potter, John

    2016-09-01

    The Visible/Infrared Imaging Radiometer Suite (VIIRS) is a key sensor on Suomi National Polar-orbiting Partnership (S-NPP) satellite launched on October 28, 2011 into a polar orbit of 824 km nominal altitude and the JPSS sensors currently being built and integrated. VIIRS collects radiometric and imagery data of the Earth's atmosphere, oceans, and land surfaces in 22 spectral bands spanning the visible and infrared spectrum from 0.4 to 12.5 μm. Interference filters assembled in `butcher-block' arrays mounted adjacent to focal plane arrays provide spectral definition. Out-of-band signal and out-of-band optical cross-talk was observed for bands in the 0.4 to 1 μm range in testing of VIIRS for S-NPP. Optical cross-talk is in-band or out-of-band light incident on an adjacent filter or adjacent region of the same filter reaching the detector. Out-of-band optical cross-talk results in spectral and spatial `impurities' in the signal and consequent errors in the calculated environmental parameters such as ocean color that rely on combinations of signals from more than one band. This paper presents results of characterization, specification, and coating process improvements that enabled production of filters with significantly reduced out of band light for Joint Polar Satellite System (JPSS) J1 and subsequent sensors. Total transmission and scatter measurements at a wavelength within the pass band can successfully characterize filter performance prior to dicing and assembling filters into butcher block assemblies. Coating and process development demonstrated performance on test samples followed by production of filters for J1 and J2. Results for J1 and J2 filters are presented.

  12. Multilevel Mixture Kalman Filter

    Directory of Open Access Journals (Sweden)

    Xiaodong Wang

    2004-11-01

    Full Text Available The mixture Kalman filter is a general sequential Monte Carlo technique for conditional linear dynamic systems. It generates samples of some indicator variables recursively based on sequential importance sampling (SIS and integrates out the linear and Gaussian state variables conditioned on these indicators. Due to the marginalization process, the complexity of the mixture Kalman filter is quite high if the dimension of the indicator sampling space is high. In this paper, we address this difficulty by developing a new Monte Carlo sampling scheme, namely, the multilevel mixture Kalman filter. The basic idea is to make use of the multilevel or hierarchical structure of the space from which the indicator variables take values. That is, we draw samples in a multilevel fashion, beginning with sampling from the highest-level sampling space and then draw samples from the associate subspace of the newly drawn samples in a lower-level sampling space, until reaching the desired sampling space. Such a multilevel sampling scheme can be used in conjunction with the delayed estimation method, such as the delayed-sample method, resulting in delayed multilevel mixture Kalman filter. Examples in wireless communication, specifically the coherent and noncoherent 16-QAM over flat-fading channels, are provided to demonstrate the performance of the proposed multilevel mixture Kalman filter.

  13. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Haakon

    2016-01-08

    The ensemble Kalman filter (EnKF) is a sequential filtering method that uses an ensemble of particle paths to estimate the means and covariances required by the Kalman filter by the use of sample moments, i.e., the Monte Carlo method. EnKF is often both robust and efficient, but its performance may suffer in settings where the computational cost of accurate simulations of particles is high. The multilevel Monte Carlo method (MLMC) is an extension of classical Monte Carlo methods which by sampling stochastic realizations on a hierarchy of resolutions may reduce the computational cost of moment approximations by orders of magnitude. In this work we have combined the ideas of MLMC and EnKF to construct the multilevel ensemble Kalman filter (MLEnKF) for the setting of finite dimensional state and observation spaces. The main ideas of this method is to compute particle paths on a hierarchy of resolutions and to apply multilevel estimators on the ensemble hierarchy of particles to compute Kalman filter means and covariances. Theoretical results and a numerical study of the performance gains of MLEnKF over EnKF will be presented. Some ideas on the extension of MLEnKF to settings with infinite dimensional state spaces will also be presented.

  14. NOTCH FILTER USING SIMULATED INDUCTOR

    Directory of Open Access Journals (Sweden)

    D.SUSAN,

    2011-06-01

    Full Text Available The design of analog filters at low frequencies is not possible because the size of inductors becomes very large. In such cases, the simulated inductors using operational amplifiers are used. This paper deals with the implementation of notch filter using band pass filter which uses simulated inductor where the direct implementation of notch filter using simulated inductor is not possible because of floating inductor. The design of notch filter and the simulation done in PSPICE is presented.

  15. Improved directional-distance filter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper proposes a new spatial-distance weighting function.By combining the weighting function and the traditional directional-distance filter (DDF) in a novel way,a new vector filter-the adaptive distance-weighted directional-distance filter (ADWDDF)-is presented.The experimental results show that the proposed solution provides better filtering performance and preserves better image chromaticity and edge or detail information compared with the traditional DDF and some other typical vector filters.

  16. DOE HEPA filter test program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL).

  17. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  18. Automated electronic filter design

    CERN Document Server

    Banerjee, Amal

    2017-01-01

    This book describes a novel, efficient and powerful scheme for designing and evaluating the performance characteristics of any electronic filter designed with predefined specifications. The author explains techniques that enable readers to eliminate complicated manual, and thus error-prone and time-consuming, steps of traditional design techniques. The presentation includes demonstration of efficient automation, using an ANSI C language program, which accepts any filter design specification (e.g. Chebyschev low-pass filter, cut-off frequency, pass-band ripple etc.) as input and generates as output a SPICE(Simulation Program with Integrated Circuit Emphasis) format netlist. Readers then can use this netlist to run simulations with any version of the popular SPICE simulator, increasing accuracy of the final results, without violating any of the key principles of the traditional design scheme.

  19. Adaptive digital filters

    CERN Document Server

    Kovačević, Branko; Milosavljević, Milan

    2013-01-01

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

  20. Spectral performance of WFIRST/AFTA bandpass filter prototypes

    Science.gov (United States)

    Quijada, Manuel A.; Huang, Winson; Miller, Kevin H.; Seide, Laurie; Content, David; Kruk, Jeffrey

    2015-09-01

    The current baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel instrument for both imaging and spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a grism assembly that will consist of a three-element assembly to disperse the central wavelength undeviated for galaxy redshift surveys. All elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper will present and discuss spectral performance (including spectral transmission and surface-figure wavefront errors ) for a subset of the bandpass filter complement that include filters such as Z087, W149, and Grism. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput (> 95 %), out of band rejection (< 10-4), spatial uniformity (< 1% transmission level) and the cut-on and cut-off slopes (≍ 3% for the filters and 0.3% for the grism coatings).

  1. Near-infrared hyperspectral reflective confocal microscopy

    Science.gov (United States)

    Huang, Wei; Zhang, Yunhai; Miao, Xin; Xue, Xiaojun; Xiao, Yun

    2016-10-01

    A Near-Infrared HyperSpectral Reflective Confocal Microscopy (NIHS-RCM) is proposed in order to get high resolution images of deep biological tissues such as skin. The microscopy system uses a super-continuum laser for illumination, an acousto-optic tunable filter (AOTF) for rapid selection of near-infrared spectrum, a resonant galvanometer scanner for high speed imaging (15f/s) and near-infrared avalanche diode as detector. Porcine skin and other experiments show that the microscopy system could get deep tissue images (180 μm), and show the different ingredients of tissue with different wavelength of illumination. The system has the ability of selectively imaging of multiple ingredients at deep tissue which can be used in skin diseases diagnosis and other fields.

  2. Filters in topology optimization

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    In this article, a modified (``filtered'') version of the minimum compliance topology optimization problem is studied. The direct dependence of the material properties on its pointwise density is replaced by a regularization of the density field using a convolution operator. In this setting...... it is possible to establish the existence of solutions. Moreover, convergence of an approximation by means of finite elements can be obtained. This is illustrated through some numerical experiments. The ``filtering'' technique is also shown to cope with two important numerical problems in topology optimization...

  3. Filters in topology optimization

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    In this article, a modified (``filtered'') version of the minimum compliance topology optimization problem is studied. The direct dependence of the material properties on its pointwise density is replaced by a regularization of the density field using a convolution operator. In this setting...... it is possible to establish the existence of solutions. Moreover, convergence of an approximation by means of finite elements can be obtained. This is illustrated through some numerical experiments. The ``filtering'' technique is also shown to cope with two important numerical problems in topology optimization...

  4. Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters

    Directory of Open Access Journals (Sweden)

    Gonzalez Juan G

    2002-01-01

    Full Text Available Linear filtering theory has been largely motivated by the characteristics of Gaussian signals. In the same manner, the proposed Myriad Filtering methods are motivated by the need for a flexible filter class with high statistical efficiency in non-Gaussian impulsive environments that can appear in practice. Myriad filters have a solid theoretical basis, are inherently more powerful than median filters, and are very general, subsuming traditional linear FIR filters. The foundation of the proposed filtering algorithms lies in the definition of the myriad as a tunable estimator of location derived from the theory of robust statistics. We prove several fundamental properties of this estimator and show its optimality in practical impulsive models such as the -stable and generalized- . We then extend the myriad estimation framework to allow the use of weights. In the same way as linear FIR filters become a powerful generalization of the mean filter, filters based on running myriads reach all of their potential when a weighting scheme is utilized. We derive the "normal" equations for the optimal myriad filter, and introduce a suboptimal methodology for filter tuning and design. The strong potential of myriad filtering and estimation in impulsive environments is illustrated with several examples.

  5. Domain wall filters

    CERN Document Server

    Bär, O; Neuberger, H; Witzel, O; Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-01-01

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  6. Fast Anisotropic Gauss Filters

    NARCIS (Netherlands)

    Geusebroek, J.M.; Smeulders, A.W.M.; van de Weijer, J.

    2003-01-01

    We derive the decomposition of the anisotropic Gaussian in a one dimensional Gauss filter in the x-direction phi. So also the anisotropic Gaussian can be decomposed by dimension. This appears to be extremely efficient from a computing perspective. An implementation scheme for normal covolution and f

  7. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  8. Magnetic-Optical Filter

    CERN Document Server

    Formicola, I; Pinto, C; Cerulo, P

    2007-01-01

    Magnetic-Optical Filter (MOF) is an instrument suited for high precision spectral measurements for its peculiar characteristics. It is employed in Astronomy and in the field of the telecommunications (it is called FADOF there). In this brief paper we summarize its fundamental structure and functioning.

  9. Enhanced Optical Filter Design

    CERN Document Server

    Cushing, David

    2011-01-01

    This book serves as a supplement to the classic texts by Angus Macleod and Philip Baumeister, taking an intuitive approach to the enhancement of optical coating (or filter) performance. Drawing from 40 years of experience in thin film design, Cushing introduces the basics of thin films, the commonly used materials and their deposition, the major coatings and their applications, and improvement methods for each.

  10. Ozone decomposing filter

    Science.gov (United States)

    Simandl, Ronald F.; Brown, John D.; Whinnery, Jr., LeRoy L.

    1999-01-01

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  11. Spot- Zombie Filtering System

    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.

  12. Digital hum filtering

    Science.gov (United States)

    Knapp, R.W.; Anderson, N.L.

    1994-01-01

    Data may be overprinted by a steady-state cyclical noise (hum). Steady-state indicates that the noise is invariant with time; its attributes, frequency, amplitude, and phase, do not change with time. Hum recorded on seismic data usually is powerline noise and associated higher harmonics; leakage from full-waveform rectified cathodic protection devices that contain the odd higher harmonics of powerline frequencies; or vibrational noise from mechanical devices. The fundamental frequency of powerline hum may be removed during data acquisition with the use of notch filters. Unfortunately, notch filters do not discriminate signal and noise, attenuating both. They also distort adjacent frequencies by phase shifting. Finally, they attenuate only the fundamental mode of the powerline noise; higher harmonics and frequencies other than that of powerlines are not removed. Digital notch filters, applied during processing, have many of the same problems as analog filters applied in the field. The method described here removes hum of a particular frequency. Hum attributes are measured by discrete Fourier analysis, and the hum is canceled from the data by subtraction. Errors are slight and the result of the presence of (random) noise in the window or asynchrony of the hum and data sampling. Error is minimized by increasing window size or by resampling to a finer interval. Errors affect the degree of hum attenuation, not the signal. The residual is steady-state hum of the same frequency. ?? 1994.

  13. Particle filter based entropy

    NARCIS (Netherlands)

    Boers, Y.; Driessen, Hans; Bagchi, Arunabha; Mandal, Pranab K.

    For many problems in the field of tracking or even the wider area of filtering the a posteriori description of the uncertainty can oftentimes not be described by a simple Gaussian density function. In such situations the characterization of the uncertainty by a mean and a covariance does not capture

  14. Spot- Zombie Filtering System

    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.

  15. Self-assembly micro optical filter

    Science.gov (United States)

    Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.

    2006-01-01

    Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

  16. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    Science.gov (United States)

    Harrivel, Angela; Hearn, Tristan A.

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in real-time. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors.

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

    Science.gov (United States)

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

  18. On the near infrared variability of chemically peculiar stars

    CERN Document Server

    Catalano, F A

    1998-01-01

    Some CP stars have recently been discovered by Catalano et al. (1991) to be variable also in the near infrared, although with smaller amplitudes than in the visible. Hence an observational campaign was started in which the infrared light variability of a number of CP2 and CP4 stars has been investigated at the ESO-La Silla Observatory in the bands J, H, and K. As a general result, infrared variations show the same behavior in all three filters but amplitudes are smaller than in the visible.

  19. Digital Filters for Low Frequency Equalization

    DEFF Research Database (Denmark)

    Tyril, Marni; Abildgaard, J.; Rubak, Per

    2001-01-01

    Digital filters with high resolution in the low-frequency range are studied. Specifically, for a given computational power, traditional IIR filters are compared with warped FIR filters, warped IIR filters, and modified warped FIR filters termed warped individual z FIR filters (WizFIR). The results...... indicate that IIR filters are the most effective in a number of situations....

  20. Demultiplexing Visible and Near-Infrared Information in Single- Sensor Multispectral Imaging

    OpenAIRE

    Sadeghipoor, Zahra; Thomas, Jean-Baptiste; Süsstrunk, Sabine

    2016-01-01

    In this paper, we study a single-sensor imaging system that uses a multispectral filter array to spectrally sample the scene. Our system captures information in both visible and near-infrared bands of the electromagnetic spectrum. Due to manufacturing limitations, the visible filters in this system also transmit the NIR radiation. Similarly, visible light is transmitted by the NIR filter, leading to inaccurate mixed spectral measurements. We present an algorithm that resolves this issue by se...

  1. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  2. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  3. Development of DWDM Filter Manufacture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    DWDM technology is developing rapidly. Thin film narrow bandpass filter plays an important role in this field. This article presents some achievements in developing the DWDM narrow bandpass filters and also describes the results achieved by us.

  4. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

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

  5. The Rao-Blackwellized Particle Filter: A Filter Bank Implementation

    Directory of Open Access Journals (Sweden)

    Karlsson Rickard

    2010-01-01

    Full Text Available For computational efficiency, it is important to utilize model structure in particle filtering. One of the most important cases occurs when there exists a linear Gaussian substructure, which can be efficiently handled by Kalman filters. This is the standard formulation of the Rao-Blackwellized particle filter (RBPF. This contribution suggests an alternative formulation of this well-known result that facilitates reuse of standard filtering components and which is also suitable for object-oriented programming. Our RBPF formulation can be seen as a Kalman filter bank with stochastic branching and pruning.

  6. Assessment of ceramic membrane filters

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R.K.; Geyer, H.K.; Im, K.H. [and others

    1995-08-01

    The objectives of this project include the development of analytical models for evaluating the fluid mechanics of membrane coated, dead-end ceramic filters, and to determine the effects of thermal and thermo-chemical aging on the material properties of emerging ceramic hot gas filters. A honeycomb cordierite monolith with a thin ceramic coating and a rigid candle filter were evaluated.

  7. Multilevel particle filter

    KAUST Repository

    Law, Kody

    2016-01-06

    This talk will pertain to the filtering of partially observed diffusions, with discrete-time observations. It is assumed that only biased approximations of the diffusion can be obtained, for choice of an accuracy parameter indexed by l. A multilevel estimator is proposed, consisting of a telescopic sum of increment estimators associated to the successive levels. The work associated to O( 2) mean-square error between the multilevel estimator and average with respect to the filtering distribution is shown to scale optimally, for example as O( 2) for optimal rates of convergence of the underlying diffusion approximation. The method is illustrated on some toy examples as well as estimation of interest rate based on real S&P 500 stock price data.

  8. Filtered cathodic arc source

    Science.gov (United States)

    Falabella, Steven; Sanders, David M.

    1994-01-01

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45.degree. to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

  9. Event Filter Dataflow Software

    CERN Document Server

    Meessen, C; Bosman, M; Karr, K M; Pacheco, A; Qian, Z; Touchard, F

    2000-01-01

    This document describes the software handling the flow of events through the Event Filter. This is the fourth iteration of the implementation of the code. When compared to previous versions, enhancements come from the feedback by users and can be seen as simplifications while the interfaces have been kept identical. The high level design of the dataflow is briefly reminded. Then, the details of the implementation of the components are given.

  10. Web Content Filtering

    OpenAIRE

    Gómez Hidalgo, José María; Puertas Sanz, Enrique; Carrero García, Francisco Manuel; Buenaga Rodríguez, Manuel de

    2009-01-01

    Across the years, Internet has evolved from an academic network to a truly communication medium, reaching impressive levels of audience and becoming a billionaire business. Many of our working, studying, and entertainment activities are nowadays overwhelmingly limited if we get disconnected from the net of networks. And of course, with the use comes abuse. The World Wide Web features a wide variety of content that are harmful for children or just inappropriate in the workplace. Web filtering ...

  11. Carbon nanotube filters

    Science.gov (United States)

    Srivastava, A.; Srivastava, O. N.; Talapatra, S.; Vajtai, R.; Ajayan, P. M.

    2004-09-01

    Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus (~25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.

  12. Archimedes Mass Filter Vaporizer

    Science.gov (United States)

    Putvinski, S.; Agnew, A. F.; Cluggish, B. P.; Ohkawa, T.; Sevier, L.; Umstadter, K. R.; Dresvin, S. V.; Kuteev, B. V.; Feygenson, O. N.; Ivanov, D. V.; Zverev, S. G.; Miroshnikov, I. V.; Egorov, S. M.; Kiesewetter, D. V.; Maliugin, V. I.

    2001-10-01

    Archimedes Technology Group, Inc., is developing a plasma mass separator called the Archimedes Filter that separates waste oxide mixtures ion by ion into two mass groups: light and heavy. Since high-level waste at Hanford has 99.9its radioactivity associated with heavy elements, the Archimedes Filter can effectively decontaminate over three-quarters of that waste. The Filter process involves some preprocessing followed by volatilization and separation by the magnetic and electric fields of the main plasma. This presentation describes the approach to volatilization of the waste oxy-hydroxide mixture by means of a very high heat flux (q > 10 MW/m2). Such a high heat flux is required to ensure congruent evaporation of the complex oxy-hydroxide mixture and is achieved by injection of small droplets of molten waste into an inductively coupled plasma (ICP) torch. This presentation further addresses different issues related to evaporation of the waste including modeling of droplet evaporation, estimates of parameters of plasma torch, and 2D modeling of the plasma. The experimental test bed for oxide vaporization and results of the initial experiments on oxide evaporation in 60 kW ICP torch will also be described.

  13. Hydrodynamics of microbial filter feeding

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor; Asadzadeh, Seyed Saeed; Dölger, Julia

    2017-01-01

    Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequat...... predict how optimum filter mesh size increases with cell size in microbial filter feeders, a prediction that accords very well with observations. We expect our results to be of significance for small-scale biophysics and trait-based ecological modeling....

  14. Fast infrared dim and small target tracking

    Science.gov (United States)

    Qian, Kun; Zhou, Huixin; Rong, Shenghui; Wang, Bingjian; Yin, Shiming; Zeng, Qingjie

    2015-10-01

    The target tracking by the spatio-temporal learning is a kind of online tracking algorithm based on Bayesian framework. But it has the excursion problem when applied in the infrared dim target. Based on the principle of the spatio-temporal learning algorithm, the excursion problem was analyzed and a new robust algorithm for infrared dim target tracking is proposed in this paper. Firstly, the Guide Image Filter was adopted to process the input image to preserve edges and eliminate the noise of the image. Secondly, the ideal spatial context model was calculated with the input image that contains little noise, which can be got by subtracting the filtering result from the original image. Simultaneously, a new weight in the context prior model was proposed to indicate that the prior is also related to the local gray level difference. The performance of the presented algorithm was tested with two infrared air image sequences, and the experimental results show that the proposed algorithm performs well in terms of efficiency, accuracy and robustness.

  15. Approximately liner phase IIR digital filter banks

    OpenAIRE

    J. D. Ćertić; M. D. Lutovac; L. D. Milić

    2013-01-01

    In this paper, uniform and nonuniform digital filter banks based on approximately linear phase IIR filters and frequency response masking technique (FRM) are presented. Both filter banks are realized as a connection of an interpolated half-band approximately linear phase IIR filter as a first stage of the FRM design and an appropriate number of masking filters. The masking filters are half-band IIR filters with an approximately linear phase. The resulting IIR filter banks are compared with li...

  16. Digital Filters for Low Frequency Equalization

    DEFF Research Database (Denmark)

    Tyril, Marni; Abildgaard, J.; Rubak, Per

    2001-01-01

    Digital filters with high resolution in the low-frequency range are studied. Specifically, for a given computational power, traditional IIR filters are compared with warped FIR filters, warped IIR filters, and modified warped FIR filters termed warped individual z FIR filters (WizFIR). The results...

  17. Band-Pass and OH-Suppression Filters for the E-ELT - Design and Prototyping

    OpenAIRE

    Guenster, S.; Ristau, D.; Davies, R.

    2011-01-01

    Optical filters are used for a variety of purposes at astronomical telescopes. In the near infrared region, from 0.8 to 2.5 um, bandpass and edge filters are used to separate the different astronomical channels, such as the J, H, and K bands. However, in the same wavelength range light emission generated in the earth's atmosphere is superimposed on the stellar radiation. Therefore, ground based astronomical instruments measure, in addition to the stellar light, also unwanted contributions fro...

  18. Improving the segmentation for weed recognition applications based on standard RGB cameras using optical filters

    DEFF Research Database (Denmark)

    Stigaard Laursen, Morten; Jørgensen, Rasmus Nyholm; Midtiby, Henrik

    . This method utilizes that most vegetation reflects more green light than blue and red. As silicon based image sensors is also sensitive to near-infrared light a typical rgb-camera will have a filter in place to block the near-infrared light. When using excess green the ideal filter would be a sinc...... diseases, weeds and fungus. A common method for interpretation is based on the leaf shape. However in order to reliably achieve a good description of the shape a good segmentation is required. The excess green index is one of the most common methods for green vegetation segmentation within agriculture...

  19. Advances in Collaborative Filtering

    Science.gov (United States)

    Koren, Yehuda; Bell, Robert

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

  20. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Hakon

    2016-06-14

    This work embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. The resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  1. Robust Kriged Kalman Filtering

    Energy Technology Data Exchange (ETDEWEB)

    Baingana, Brian; Dall' Anese, Emiliano; Mateos, Gonzalo; Giannakis, Georgios B.

    2015-11-11

    Although the kriged Kalman filter (KKF) has well-documented merits for prediction of spatial-temporal processes, its performance degrades in the presence of outliers due to anomalous events, or measurement equipment failures. This paper proposes a robust KKF model that explicitly accounts for presence of measurement outliers. Exploiting outlier sparsity, a novel l1-regularized estimator that jointly predicts the spatial-temporal process at unmonitored locations, while identifying measurement outliers is put forth. Numerical tests are conducted on a synthetic Internet protocol (IP) network, and real transformer load data. Test results corroborate the effectiveness of the novel estimator in joint spatial prediction and outlier identification.

  2. Charcoal filter testing

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J. [Nuclear Regulatory Commission, Washington, DC (United States)

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  3. From Microwave Filter to Digital Filter and Back Again

    DEFF Research Database (Denmark)

    Dalby, Arne Brejning

    1989-01-01

    A new very simple state variable flow graph representation for interdigital transmission line bandpass filters is presented, which has led to two important results: 1) A new type of digital filter with properties, that surpass the properties of most other (all pole) digital filtertypes. 2......) The study of the new digital filtertype has led to design formulas for interdigital transmission line filters that are very simple compared to the hitherto known formulas. The accuracy is the same or better....

  4. Filter and Filter Bank Design for Image Texture Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Trygve

    1997-12-31

    The relevance of this thesis to energy and environment lies in its application to remote sensing such as for instance sea floor mapping and seismic pattern recognition. The focus is on the design of two-dimensional filters for feature extraction, segmentation, and classification of digital images with textural content. The features are extracted by filtering with a linear filter and estimating the local energy in the filter response. The thesis gives a review covering broadly most previous approaches to texture feature extraction and continues with proposals of some new techniques. 143 refs., 59 figs., 7 tabs.

  5. Nanoparticle optical notch filters

    Science.gov (United States)

    Kasinadhuni, Pradeep Kumar

    Developing novel light blocking products involves the design of a nanoparticle optical notch filter, working on the principle of localized surface plasmon resonance (LSPR). These light blocking products can be used in many applications. One such application is to naturally reduce migraine headaches and light sensitivity. Melanopsin ganglion cells present in the retina of the human eye, connect to the suprachiasmatic nucleus (SCN-the body's clock) in the brain, where they participate in the entrainment of the circadian rhythms. As the Melanopsin ganglion cells are involved in triggering the migraine headaches in photophobic patients, it is necessary to block the part of visible spectrum that activates these cells. It is observed from the action potential spectrum of the ganglion cells that they absorb light ranging from 450-500nm (blue-green part) of the visible spectrum with a λmax (peak sensitivity) of around 480nm (blue line). Currently prescribed for migraine patients is the FL-41 coating, which blocks a broad range of wavelengths, including wavelengths associated with melanopsin absorption. The nanoparticle optical notch filter is designed to block light only at 480nm, hence offering an effective prescription for the treatment of migraine headaches.

  6. Robust fault detection filter design

    Science.gov (United States)

    Douglas, Randal Kirk

    The detection filter is a specially tuned linear observer that forms the residual generation part of an analytical redundancy system designed for model-based fault detection and identification. The detection filter has an invariant state subspace structure that produces a residual with known and fixed directional characteristics in response to a known design fault direction. In addition to a parameterization of the detection filter gain, three methods are given for improving performance in the presence of system disturbances, sensor noise, model mismatch and sensitivity to small parameter variations. First, it is shown that by solving a modified algebraic Riccati equation, a stabilizing detection filter gain is found that bounds the H-infinity norm of the transfer matrix from system disturbances and sensor noise to the detection filter residual. Second, a specially chosen expanded-order detection filter is formed with fault detection properties identical to a set of independent reduced-order filters that have no structural constraints. This result is important to the practitioner because the difficult problem of finding a detection filter insensitive to disturbances and sensor noise is converted to the easier problem of finding a set of uncoupled noise insensitive filters. Furthermore, the statistical properties of the reduced-order filter residuals are easier to find than the statistical properties of the structurally constrained detection filter residual. Third, an interpretation of the detection filter as a special case of the dual of the restricted decoupling problem leads to a new detection filter eigenstructure assignment algorithm. The new algorithm places detection filter left eigenvectors, which annihilate the detection spaces, rather than right eigenvectors, which span the detection spaces. This allows for a more flexible observer based fault detection system structure that could not be formulated as a detection filter. Furthermore, the link to the dual

  7. Infrared Radiation of Flames

    Science.gov (United States)

    1961-10-01

    March 1960. 4. S. Silverman, G. A. Hornbeck, and R. C. Herman , J. Chem. Phys. 16 155 (1947). The Infrared Emission and Absorption or-the Carbon Monoxide...by Infrared Radiation. 9. S. Silverman and R. C. Herman , J. Opt. Soc. Am. 32, 216 (1949). The Infrared Emission Spectra of the Oxy- Hydrogen and Oxy...Press, 1961). 35. W. J, Pearce, Conference on Extremely High Temperatures, Fischer and Mansur , eds. (John Wiley & Sons, New York, 1958), p. 123. 36. M. P

  8. Spatial filters for high average power lasers

    Science.gov (United States)

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  9. Reconfigurable Mixed Mode Universal Filter

    Directory of Open Access Journals (Sweden)

    Neelofer Afzal

    2014-01-01

    Full Text Available This paper presents a novel mixed mode universal filter configuration capable of working in voltage and transimpedance mode. The proposed single filter configuration can be reconfigured digitally to realize all the five second order filter functions (types at single output port. Other salient features of proposed configuration include independently programmable filter parameters, full cascadability, and low sensitivity figure. However, all these features are provided at the cost of quite large number of active elements. It needs three digitally programmable current feedback amplifiers and three digitally programmable current conveyors. Use of six active elements is justified by introducing three additional reduced hardware mixed mode universal filter configurations and its comparison with reported filters.

  10. Wavelength Filters in Fibre Optics

    CERN Document Server

    Venghaus, Herbert

    2006-01-01

    Wavelength filters constitute an essential element of fibre-optic networks. This book gives a comprehensive account of the principles and applications of such filters, including their technological realisation. After an introductory chapter on wavelength division multiplexing in current and future fibre optic networks follows a detailed treatment of the phase characteristics of wavelength filters, a factor frequently neglected but of significant importance at high bit rates. Subsequent chapters cover three-dimensional reflection of gratings, arrayed waveguide gratings, fibre Bragg gratings, Fabry-Perot filters, dielectric multilayer filters, ring filters, and interleavers. The book explains the relevant performance parameters, the particular advantages and shortcomings of the various concepts and components, and the preferred applications. It also includes in-depth information on the characteristics of both commercially available devices and those still at the R&D stage. All chapters are authored by inter...

  11. Trends in Correlation-Based Pattern Recognition and Tracking in Forward-Looking Infrared Imagery

    Science.gov (United States)

    Alam, Mohammad S.; Bhuiyan, Sharif M. A.

    2014-01-01

    In this paper, we review the recent trends and advancements on correlation-based pattern recognition and tracking in forward-looking infrared (FLIR) imagery. In particular, we discuss matched filter-based correlation techniques for target detection and tracking which are widely used for various real time applications. We analyze and present test results involving recently reported matched filters such as the maximum average correlation height (MACH) filter and its variants, and distance classifier correlation filter (DCCF) and its variants. Test results are presented for both single/multiple target detection and tracking using various real-life FLIR image sequences. PMID:25061840

  12. Infrared Microscopy In An Industrial Analytical Laboratory

    Science.gov (United States)

    Strawn, A. W.

    1989-12-01

    This paper describes the chemical identification of solid samples in the size range of 8-250um in diameter. The samples are usually inhomogeneous and range from polymer inclusions to fibres. While scanning electron and optical microscopy are usually the first line of analysis for such samples, they cannot yield chemical identification when the sample is organic. A combination of infrared microscopy and spectral library searching provides a powerful technique in the industrial laboratory and examples are shown of polymer inclusions, laminates, fibres and filter deposits. The spectra were obtained using a Spectra-Tech IR Plan Microscope coupled to the external port of a Nicolet 5DXC FTIR spectrometer whose main compartment houses an MTEC Photoacoustic (PAS) Cell. The complementary facets of PAS and infrared microscopy are also highlighted.

  13. Dedicated Filter for Robust Occupancy Grid Mapping

    Directory of Open Access Journals (Sweden)

    KS Nagla

    2015-03-01

    Full Text Available Sensor based perception of the environment is an emerging area of the mobile robot research where sensors play a pivotal role. For autonomous mobile robots, the fundamental requirement is the convergent of the range information in to high level internal representation. Internal representation in the form of occupancy grid is commonly used in autonomous mobile robots due to its various advantages. There are several sensors such as vision sensor, laser rage finder, and ultrasonic and infrared sensors etc. play roles in mapping. However the sensor information failure, sensor inaccuracies, noise, and slow response are the major causes of an error in the mapping. To improve the reliability of the mobile robot mapping multisensory data fusion is considered as an optimal solution. This paper presents a novel architecture of sensor fusion frame work in which a dedicated filter (DF is proposed to increase the robustness of the occupancy grid for indoor environment. The technique has been experimentally verified for different indoor test environments. The proposed configuration shows improvement in the occupancy grid with the implementation of dedicated filters.

  14. Infrared technology and applications

    Energy Technology Data Exchange (ETDEWEB)

    Lettington, A.H. (Royal Signals and Radar Establishment, Malvern (United Kingdom))

    1990-01-01

    This book is covered by the following topics: innovations in industrial infrared spectroscopy, detectors, advances in applied thermography, optical manufacturing techniques, optical design and testing.

  15. Semi-Hausdorff Fuzzy Filters

    Directory of Open Access Journals (Sweden)

    V. Lakshmana Gomathi Nayagam

    2007-01-01

    Full Text Available The notion of fuzzy filters was studied by Vicente and Aranguren (1988, Lowen (1979, and Ramakrishnan and Nayagam (2002. The notion of fuzzily compactness was introduced and studied by Ramakrishnan and Nayagam (2002. In this paper, an equivalent condition of fuzzily compactness is studied and a new notion of semi-Hausdorffness on fuzzy filters, which cannot be defined in crisp theory of filters, is introduced and studied.

  16. Cuckoo Filter: Simplification and Analysis

    OpenAIRE

    Eppstein, David

    2016-01-01

    The cuckoo filter data structure of Fan, Andersen, Kaminsky, and Mitzenmacher (CoNEXT 2014) performs the same approximate set operations as a Bloom filter in less memory, with better locality of reference, and adds the ability to delete elements as well as to insert them. However, until now it has lacked theoretical guarantees on its performance. We describe a simplified version of the cuckoo filter using fewer hash function calls per query. With this simplification, we provide the first theo...

  17. Multi-filter spectrophotometry simulations

    Science.gov (United States)

    Callaghan, Kim A. S.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    To complement both the multi-filter observations of quasar environments described in these proceedings, as well as the proposed UBC 2.7 m Liquid Mirror Telescope (LMT) redshift survey, we have initiated a program of simulated multi-filter spectrophotometry. The goal of this work, still very much in progress, is a better quantitative assessment of the multiband technique as a viable mechanism for obtaining useful redshift and morphological class information from large scale multi-filter surveys.

  18. Mid infrared emission spectroscopy of carbon plasma

    Science.gov (United States)

    Nemes, Laszlo; Brown, Ei Ei; Yang, Clayton S.-C.; Hommerich, Uwe

    2017-01-01

    Mid infrared time-resolved emission spectra were recorded from laser-induced carbon plasma. These spectra constitute the first study of carbon materials LIB spectroscopy in the mid infrared range. The carbon plasma was induced using a Q-switched Nd: YAG laser. The laser beam was focused to high purity graphite pellets mounted on a translation stage. Mid infrared emission from the plasma in an atmospheric pressure background gas was detected by a cooled HgCdTe detector in the range 4.4-11.6 μm, using long-pass filters. LIB spectra were taken in argon, helium and also in air. Despite a gate delay of 10 μs was used there were strong backgrounds in the spectra. Superimposed on this background broad and noisy emission bands were observed, the form and position of which depended somewhat on the ambient gas. The spectra were digitally smoothed and background corrected. In argon, for instance, strong bands were observed around 4.8, 6.0 and 7.5 μm. Using atomic spectral data by NIST it could be concluded that carbon, argon, helium and nitrogen lines from neutral and ionized atoms are very weak in this spectral region. The width of the infrared bands supports molecular origin. The infrared emission bands were thus compared to vibrational features of carbon molecules (excluding C2) of various sizes on the basis of previous carbon cluster infrared absorption and emission spectroscopic analyses in the literature and quantum chemical calculations. Some general considerations are given about the present results.

  19. Mid infrared emission spectroscopy of carbon plasma.

    Science.gov (United States)

    Nemes, Laszlo; Brown, Ei Ei; S-C Yang, Clayton; Hommerich, Uwe

    2017-01-05

    Mid infrared time-resolved emission spectra were recorded from laser-induced carbon plasma. These spectra constitute the first study of carbon materials LIB spectroscopy in the mid infrared range. The carbon plasma was induced using a Q-switched Nd: YAG laser. The laser beam was focused to high purity graphite pellets mounted on a translation stage. Mid infrared emission from the plasma in an atmospheric pressure background gas was detected by a cooled HgCdTe detector in the range 4.4-11.6μm, using long-pass filters. LIB spectra were taken in argon, helium and also in air. Despite a gate delay of 10μs was used there were strong backgrounds in the spectra. Superimposed on this background broad and noisy emission bands were observed, the form and position of which depended somewhat on the ambient gas. The spectra were digitally smoothed and background corrected. In argon, for instance, strong bands were observed around 4.8, 6.0 and 7.5μm. Using atomic spectral data by NIST it could be concluded that carbon, argon, helium and nitrogen lines from neutral and ionized atoms are very weak in this spectral region. The width of the infrared bands supports molecular origin. The infrared emission bands were thus compared to vibrational features of carbon molecules (excluding C2) of various sizes on the basis of previous carbon cluster infrared absorption and emission spectroscopic analyses in the literature and quantum chemical calculations. Some general considerations are given about the present results.

  20. Fast, electrically tunable filters for hyperspectral imaging

    Science.gov (United States)

    Liberman, V.; Parameswaran, L.; Gear, C.; Cabral, A.; Rothschild, M.

    2014-06-01

    Tunable, narrow-wavelength spectral filters with a ms response in the mid-wave/long-wave infrared (MW/LWIR) are an enabling technology for hyperspectral imaging systems. Few commercial off-the-shelf (COTS) components for this application exist, including filter wheels, movable gratings, and Fabry-Perot (FP) etalon-based devices. These devices can be bulky, fragile and often do not have the required response speed. Here, we present a fundamentally different approach for tunable reflective IR filters, based on coupling subwavelength plasmonic antenna arrays with liquid crystals (LCs). Our device operates in reflective mode and derives its narrow bandwidth from diffractive coupling of individual antenna elements. The wavelength tunability of the device arises from electrically-induced re-orientation of the LC material in intimate contact with antenna array. This re-orientation, in turn, induces a change in the local dielectric environment of the antenna array, leading to a wavelength shift. We will first present results of full-field optimization of micron-size antenna geometries to account for complex 3D LC anisotropy. We have fabricated these antenna arrays on IR-transparent CaF2 substrates utilizing electron beam lithography, and have demonstrated tunability using 5CB, a commercially available LC. However, the design can be extended to high-birefringence liquid crystals for an increased tuning range. Our initial results demonstrate <60% peak reflectance in the 4- 6 μm wavelength range with a tunability of 0.2 μm with re-orientation of the surface alignment layers. Preliminary electrical switching has been demonstrated and is being optimized.

  1. Filters and supports in orthoalgebras

    Science.gov (United States)

    Foulis, D. J.; Greechie, R. J.; Rüttimann, G. T.

    1992-05-01

    An orthoalgebra, which is a natural generalization of an orthomodular lattice or poset, may be viewed as a “logic” or “proposition system” and, under a welldefined set of circumstances, its elements may be classified according to the Aristotelian modalities: necessary, impossible, possible, and contingent. The necessary propositions band together to form a local filter, that is, a set that intersects every Boolean subalgebra in a filter. In this paper, we give a coherent account of the basic theory of Orthoalgebras, define and study filters, local filters, and associated structures, and prove a version of the compactness theorem in classical algebraic logic.

  2. Spatial filtering with photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

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

  3. Optimization of integrated polarization filters

    CERN Document Server

    Gagnon, Denis; Déziel, Jean-Luc; Dubé, Louis J

    2014-01-01

    This study reports on the design of small footprint, integrated polarization filters based on engineered photonic lattices. Using a rods-in-air lattice as a basis for a TE filter and a holes-in-slab lattice for the analogous TM filter, we are able to maximize the degree of polarization of the output beams up to 98 % with a transmission efficiency greater than 75 %. The proposed designs allow not only for logical polarization filtering, but can also be tailored to output an arbitrary transverse beam profile. The lattice configurations are found using a recently proposed parallel tabu search algorithm for combinatorial optimization problems in integrated photonics.

  4. Adaptive filtering and change detection

    CERN Document Server

    Gustafsson, Fredrik

    2003-01-01

    Adaptive filtering is a classical branch of digital signal processing (DSP). Industrial interest in adaptive filtering grows continuously with the increase in computer performance that allows ever more conplex algorithms to be run in real-time. Change detection is a type of adaptive filtering for non-stationary signals and is also the basic tool in fault detection and diagnosis. Often considered as separate subjects Adaptive Filtering and Change Detection bridges a gap in the literature with a unified treatment of these areas, emphasizing that change detection is a natural extensi

  5. Filter selection using genetic algorithms

    Science.gov (United States)

    Patel, Devesh

    1996-03-01

    Convolution operators act as matched filters for certain types of variations found in images and have been extensively used in the analysis of images. However, filtering through a bank of N filters generates N filtered images, consequently increasing the amount of data considerably. Moreover, not all these filters have the same discriminatory capabilities for the individual images, thus making the task of any classifier difficult. In this paper, we use genetic algorithms to select a subset of relevant filters. Genetic algorithms represent a class of adaptive search techniques where the processes are similar to natural selection of biological evolution. The steady state model (GENITOR) has been used in this paper. The reduction of filters improves the performance of the classifier (which in this paper is the multi-layer perceptron neural network) and furthermore reduces the computational requirement. In this study we use the Laws filters which were proposed for the analysis of texture images. Our aim is to recognize the different textures on the images using the reduced filter set.

  6. Kalman filtering implementation with Matlab

    OpenAIRE

    Kleinbauer, Rachel

    2004-01-01

    1960 und 1961 veröffentlichte Rudolf Emil Kalmen seine Arbeiten über einen rekursiven prädiktiven Filter, der auf dem Gebrauch von rekursiven Algorithmen basiert. Damit revolutionierte er das Feld der Schätzverfahren. Seitdem ist der sogenannte Kalman Filter Gegenstand ausführlicher Forschung und findet bis heute Anwendung in zahlreichen Gebieten. Der Kalman Filter schätzt den Zustand eines dynamischen Systems, auch wenn die exakte Form dieses Systems unbekannt ist. Der Filter ist sehr lei...

  7. The intractable cigarette 'filter problem'.

    Science.gov (United States)

    Harris, Bradford

    2011-05-01

    When lung cancer fears emerged in the 1950s, cigarette companies initiated a shift in cigarette design from unfiltered to filtered cigarettes. Both the ineffectiveness of cigarette filters and the tobacco industry's misleading marketing of the benefits of filtered cigarettes have been well documented. However, during the 1950s and 1960s, American cigarette companies spent millions of dollars to solve what the industry identified as the 'filter problem'. These extensive filter research and development efforts suggest a phase of genuine optimism among cigarette designers that cigarette filters could be engineered to mitigate the health hazards of smoking. This paper explores the early history of cigarette filter research and development in order to elucidate why and when seemingly sincere filter engineering efforts devolved into manipulations in cigarette design to sustain cigarette marketing and mitigate consumers' concerns about the health consequences of smoking. Relevant word and phrase searches were conducted in the Legacy Tobacco Documents Library online database, Google Patents, and media and medical databases including ProQuest, JSTOR, Medline and PubMed. 13 tobacco industry documents were identified that track prominent developments involved in what the industry referred to as the 'filter problem'. These reveal a period of intense focus on the 'filter problem' that persisted from the mid-1950s to the mid-1960s, featuring collaborations between cigarette producers and large American chemical and textile companies to develop effective filters. In addition, the documents reveal how cigarette filter researchers' growing scientific knowledge of smoke chemistry led to increasing recognition that filters were unlikely to offer significant health protection. One of the primary concerns of cigarette producers was to design cigarette filters that could be economically incorporated into the massive scale of cigarette production. The synthetic plastic cellulose acetate

  8. Multispectral mid-infrared imaging using frequency upconversion

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Dam, Jeppe Seidelin; Jensen, Ole Bjarlin;

    2013-01-01

    It has recently been shown that it is possible to upconvert infrared images to the near infrared region with high quantum efficiency and low noise by three-wave mixing with a laser field [1]. If the mixing laser is single-frequency, the upconverted image is simply a band-pass filtered version......: Infrared imaging, nonlinear frequency conversion, diode lasers, upconversion ] of the nonlinear material. Unfortunately, temperature tuning is slow, and angle tuning typically results in alignment issues. Here we present a novel approach where the wavelength of the mixing field is used as a tuning...... feedback grating. The output from a tunable laser is used as seed for a fiber amplifier system, boosting the power to approx. 3 W over the tuning range from 1025 to 1085 nm. Using a periodically poled lithium niobate crystal, the infrared wavelength that can be phase-matched is tunable over more than 200...

  9. Multispectral mid-infrared imaging using frequency upconversion

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Dam, Jeppe Seidelin; Jensen, Ole Bjarlin

    2013-01-01

    of the infrared object field, with a bandwidth corresponding given by the acceptance parameter of the conversion process, and a center frequency given by the phase-match condition. Tuning of the phase-matched wavelengths has previously been demonstrated by changing the temperature [2] or angle [3 Keywords......It has recently been shown that it is possible to upconvert infrared images to the near infrared region with high quantum efficiency and low noise by three-wave mixing with a laser field [1]. If the mixing laser is single-frequency, the upconverted image is simply a band-pass filtered version......: Infrared imaging, nonlinear frequency conversion, diode lasers, upconversion ] of the nonlinear material. Unfortunately, temperature tuning is slow, and angle tuning typically results in alignment issues. Here we present a novel approach where the wavelength of the mixing field is used as a tuning...

  10. Particle Kalman Filtering: A Nonlinear Framework for Ensemble Kalman Filters

    KAUST Repository

    Hoteit, Ibrahim

    2010-09-19

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

  11. A curvature filter and PDE based non-uniformity correction algorithm

    Science.gov (United States)

    Cheng, Kuanhong; Zhou, Huixin; Qin, Hanlin; Zhao, Dong; Qian, Kun; Rong, Shenghui; Yin, Shimin

    2016-10-01

    In this paper, a curvature filter and PDE based non-uniformity correction algorithm is proposed, the key point of this algorithm is the way to estimate FPN. We use anisotropic diffusion to smooth noise and Gaussian curvature filter to extract the details of original image. Then combine these two parts together by guided image filter and subtract the result from original image to get the crude approximation of FPN. After that, a Temporal Low Pass Filter (TLPF) is utilized to filter out random noise and get the accurate FPN. Finally, subtract the FPN from original image to achieve non-uniformity correction. The performance of this algorithm is tested with two infrared image sequences, and the experimental results show that the proposed method achieves a better non-uniformity correction performance.

  12. A Method to improve line flux and redshift measurements with narrowband filters

    CERN Document Server

    Zabl, J; Møller, P; Milvang-Jensen, B; Nilsson, K K; Fynbo, J P U; Fèvre, O Le; Tasca, L A M

    2016-01-01

    High redshift star-forming galaxies are discovered routinely through a flux excess in narrowband filters (NB) caused by an emission line. In most cases, the width of such filters is broad compared to typical line widths, and the throughput of the filters varies substantially within the bandpass. This leads to substantial uncertainties in redshifts and fluxes that are derived from the observations with one specific NB. In this work we demonstrate that the uncertainty in measured line parameters can be sharply reduced by using repeated observations of the same target field with filters that have slightly different transmittance curves. Such data are routinely collected with some large field imaging cameras that use multiple detectors and a separate filter for each of the detectors. An example is the NB118 data from ESO's VISTA InfraRed CAMera (VIRCAM). We carefully developed and characterized this method to determine more accurate redshift and line flux estimates from the ratio of apparent fluxes measured from ...

  13. Scale effects: HCMM data simulation. Usage of filtering techniques for scaling-up simulations

    Science.gov (United States)

    Digennaro, V. (Principal Investigator)

    1980-01-01

    Image reduction used to simulate increase in altitude of an acquisition platform is equivalent to data smoothing, and can be achieved either by neighborhood averaging or by filtering techniques. The averaging approach is limited for accurate simulation. A filtering method is described which was based on the hypothesis that all changes due to altitude increase can be represented by a point spread function. Determination of the scale function and factor are discussed as well as implementation of the filtering. Filtering can be either in the spatial or frequency domain. In the spatial domain, filtering consists of the convolution of the image with the weights mask, and then of the declination of the points according to the appropriates scale factor. A simulation of an aircraft day image in the infrared channel is examined.

  14. Application of DFT Filter Banks and Cosine Modulated Filter Banks in Filtering

    Science.gov (United States)

    Lin, Yuan-Pei; Vaidyanathan, P. P.

    1994-01-01

    None given. This is a proposal for a paper to be presented at APCCAS '94 in Taipei, Taiwan. (From outline): This work is organized as follows: Sec. II is devoted to the construction of the new 2m channel under-decimated DFT filter bank. Implementation and complexity of this DFT filter bank are discussed therein. IN a similar manner, the new 2m channel cosine modulated filter bank is discussed in Sec. III. Design examples are given in Sec. IV.

  15. Application of DFT Filter Banks and Cosine Modulated Filter Banks in Filtering

    Science.gov (United States)

    Lin, Yuan-Pei; Vaidyanathan, P. P.

    1994-01-01

    None given. This is a proposal for a paper to be presented at APCCAS '94 in Taipei, Taiwan. (From outline): This work is organized as follows: Sec. II is devoted to the construction of the new 2m channel under-decimated DFT filter bank. Implementation and complexity of this DFT filter bank are discussed therein. IN a similar manner, the new 2m channel cosine modulated filter bank is discussed in Sec. III. Design examples are given in Sec. IV.

  16. Bridging the ensemble Kalman filter and particle filters: the adaptive Gaussian mixture filter

    OpenAIRE

    Stordal, Andreas Størksen; Karlsen, Hans A.; Nævdal, Geir; Hans J. Skaug; Vallès, Brice

    2010-01-01

    The nonlinear filtering problem occurs in many scientific areas. Sequential Monte Carlo solutions with the correct asymptotic behavior such as particle filters exist, but they are computationally too expensive when working with high-dimensional systems. The ensemble Kalman filter (EnKF) is a more robust method that has shown promising results with a small sample size, but the samples are not guaranteed to come from the true posterior distribution. By approximating the model error with a Gauss...

  17. Infrared design examples

    CERN Document Server

    Wolfe, William L

    1999-01-01

    This tutorial covers infrared design examples in considerable detail, building on principles presented in an earlier text, 'Introduction to Infrared System Design' (SPIE PRESS Vol. TT24). The text explores a range of problems illustrating several design issues, with applications in military, industry, aeronautics, space, and medicine, among others.

  18. 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.

  19. Radiation Hard Bandpass Filters for Mid- to Far-IR Planetary Instruments

    Science.gov (United States)

    Brown, Ari D.; Aslam, Shahid; Chervenack, James A.; Huang, Wei-Chung; Merrell, Willie C.; Quijada, Manuel; Steptoe-Jackson, Rosalind; Wollack, Edward J.

    2012-01-01

    We present a novel method to fabricate compact metal mesh bandpass filters for use in mid- to far-infrared planetary instruments operating in the 20-600 micron wavelength spectral regime. Our target applications include thermal mapping instruments on ESA's JUICE as well as on a de-scoped JEO. These filters are novel because they are compact, customizable, free-standing copper mesh resonant bandpass filters with micromachined silicon support frames. The filters are well suited for thermal mapping mission to the outer planets and their moons because the filter material is radiation hard. Furthermore, the silicon support frame allows for effective hybridization with sensors made on silicon substrates. Using a Fourier Transform Spectrometer, we have demonstrated high transmittance within the passband as well as good out-of-band rejection [1]. In addition, we have developed a unique method of filter stacking in order to increase the bandwidth and sharpen the roll-off of the filters. This method allows one to reliably control the spacing between filters to within 2 microns. Furthermore, our method allows for reliable control over the relative position and orienta-tion between the shared faces of the filters.

  20. A Novel Infrared Gas Monitor

    Science.gov (United States)

    Wang, Yingding; Zhong, Hongjie

    2000-03-01

    In the paper a novel non-dispersive infrared(IR) gas monitor is described.It is based on the principle that certain gases absorb IR radiation at specific(and often unique) wavelengths.Conventional devices typically include several primary components:a broadband source, usually an incandescent filament,a rotating chopper shutter,a narrow-band filter,a sample tube and a detector. We have developed a number of IR light emitting diodes(LED) having narrow optical bandwidths and which can be intensity modulated by electrical means,for example InAsSbP(4.2 micron)LED.The IR LED can thus replace the thermal source,narrow-band filter and chopper assembly of the conventional IR gas monitor,yielding a solid state,low- powered,compact and almost maintenance-free instrument with high sensitivity and stability and which free of the effects of mechanical vibration too. The detector used in the IR gas monitor is the solid-state detector,such as PbS,PbSe, InSb,HgCdTe,TGS,LT and PZT detector etc. The different configuration of the IR gas monitor is designed.For example,two-path version for measuring methane concentration by monitoring the 3.31 micron absorption band,it can eliminate the interference effects,such as to compensate for LED intensity changes caused by power and temperature variations,and for signal fluctuations due to changes in detector bias. we also have designed portable single-beam version without the sample tube.Its most primary advantage is very cheap(about cost USD 30 ).It measures carbon dioxide concentration by monitoring the 4.25 micron absorption band.Thought its precisions is low,it is used to control carbon dioxide concentration in the air in the green houses and plastic houses(there are about twenty millon one in the China).Because more carbon dioxide will increase the quanity of vegetable and flower production to a greatextent. It also is used in medical,sanitary and antiepidemic applications,such as hospital, store,hotel,cabin and ballroom etc. Key words:infrared

  1. Digital Filters Using Identical Blocks

    Directory of Open Access Journals (Sweden)

    S. C. Dutta

    1985-07-01

    Full Text Available Improved response of non-recursive digital filters is achieved using Amplitude Change Functions (ACFs on a prototype filter. A generalized ACF with interesting properties is suggested. Methods for achieving variable cut-off frequency and frequency transformation are explained. A modular hardware implementation is also presented.

  2. Digital filter synthesis computer program

    Science.gov (United States)

    Moyer, R. A.; Munoz, R. M.

    1968-01-01

    Digital filter synthesis computer program expresses any continuous function of a complex variable in approximate form as a computational algorithm or difference equation. Once the difference equation has been developed, digital filtering can be performed by the program on any input data list.

  3. Polarizing Filter for Integrated Optics

    Science.gov (United States)

    Ramer, O. G.; Goss, W. C.; Goldstein, R.

    1986-01-01

    Polarizing filter for titanium-doped lithium niobate light waveguide suppresses transverse magnetic (TM) mode of light propagation while allowing transverse electric (TE) mode to continue on its way. Filter - lithium niobate crystal - is expected to find many applications in integrated optical circuits.

  4. Filter-extruded liposomes revisited

    DEFF Research Database (Denmark)

    Hinna, Askell; Steiniger, Frank; Hupfeld, Stefan;

    2016-01-01

    Filter-extrusion is a widely used technique for down-sizing of phospholipid vesicles. In order to gain a detailed insight into size and size distributions of filter-extruded vesicles composed of egg phosphatidyl-choline (with varying fractions of cholesterol) – in relation to extrusionparameters...

  5. Cold Crystal Reflector Filter Concept

    CERN Document Server

    Muhrer, G

    2014-01-01

    In this paper the theoretical concept of a cold crystal reflector filter will be presented. The aim of this concept is to balance the shortcoming of the traditional cold polycrystalline reflector filter, which lies in the significant reduction of the neutron flux right above (in energy space) or right below (wavelength space) the first Bragg edge.

  6. Tracking speckle displacement by double Kalman filtering

    Institute of Scientific and Technical Information of China (English)

    Donghui Li; Li Guo

    2006-01-01

    @@ A tracking technique using two sequentially-connected Kalman filter for tracking laser speckle displacement is presented. One Kalman filter tracks temporal speckle displacement, while another Kalman filter tracks spatial speckle displacement. The temporal Kalman filter provides a prior for the spatial Kalman filter, and the spatial Kalman filter provides measurements for the temporal Kalman filter. The contribution of a prior to estimations of the spatial Kalman filter is analyzed. An optical analysis system was set up to verify the double-Kalman-filter tracker's ability of tracking laser speckle's constant displacement.

  7. Quantitative determination of the fat, protein, lactose, and water content in cow milk using Fourier transform infrared spectrometry

    Science.gov (United States)

    Luinge, Hendrik J.; Hop, E.; Lutz, E. T.; van der Maas, John H.; Holstra, A.; van Hemert, H. A.; Koops, J.; Wooldrik, H.; de Jong, E. A.; Ellen, G.

    1992-03-01

    In this paper the quantitative analysis of the four major components in cow milk using Fourier transform infrared spectrometry is described. Least squares regression using selected wavenumber regions is compared with full spectrum methods such as principal component regression (PCR) and partial least squares regression (PLS). Results are comparable with data obtained from infrared filter instruments with respect to precision and accuracy.

  8. Recycling used automotive oil filters

    Science.gov (United States)

    Peaslee, Kent D.

    1994-02-01

    Over 400 million used automotive oil filters are discarded in the United States each year, most of which are disposed of in landfills wasting valuable resources and risking contamination of ground- and surface-water supplies. This article summarizes U.S. bureau of Mines research evaluating scrap prepared from used automotive oil filters. Experimental results show that crushed and drained oil filters have a bulk density that is higher than many typical scrap grades, a chemical analysis low in residual elements (except tin due to use of tin plate in filters), and an overall yield, oil-filter scrap to cast steel, of 76% to 85%, depending on the method used to prepare the scrap.

  9. Identification Filtering with fuzzy estimations

    Directory of Open Access Journals (Sweden)

    J.J Medel J

    2012-10-01

    Full Text Available A digital identification filter interacts with an output reference model signal known as a black-box output system. The identification technique commonly needs the transition and gain matrixes. Both estimation cases are based on mean square criterion obtaining of the minimum output error as the best estimation filtering. The evolution system represents adaptive properties that the identification mechanism includes considering the fuzzy logic strategies affecting in probability sense the evolution identification filter. The fuzzy estimation filter allows in two forms describing the transition and the gain matrixes applying actions that affect the identification structure. Basically, the adaptive criterion conforming the inference mechanisms set, the Knowledge and Rule bases, selecting the optimal coefficients in distribution form. This paper describes the fuzzy strategies applied to the Kalman filter transition function, and gain matrixes. The simulation results were developed using Matlab©.

  10. DSP Control of Line Hybrid Active Filter

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.;

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter ...

  11. Near-infrared transillumination photography of intraocular tumours.

    Science.gov (United States)

    Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

    2013-10-01

    To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

  12. Greenhouse with an Integrated NIR Filter and a Solar Cooling System

    NARCIS (Netherlands)

    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

  13. Greenhouse with an Integrated NIR Filter and a Solar Cooling System

    NARCIS (Netherlands)

    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

  14. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel....... Furthermore, its pressure drop changed very little during the 5 months of service, and it had the added benefit of removing a large fraction of ozone from the airstream. If similar results are obtained over a wider variety of soiling conditions, such filters may be a viable solution to a long recognized...

  15. TIRSPEC : TIFR Near Infrared Spectrometer and Imager

    CERN Document Server

    Ninan, J P; Ghosh, S K; D'Costa, S L A; Naik, M B; Poojary, S S; Sandimani, P R; Meshram, G S; Jadhav, R B; Bhagat, S B; Gharat, S M; Bakalkar, C B; Prabhu, T P; Anupama, G C; Toomey, D W

    2014-01-01

    We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT), Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The TIRSPEC provides for various modes of operation which include photometry with broad and narrow band filters, spectrometry in single order mode with long slits of 300" length and different widths, with order sorter filters in the Y, J, H and K bands and a grism as the dispersing element as well as a cross dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was successfully commissioned in June 2013 and the subsequent characterization and astronomical observatio...

  16. Infrared Solar Physics

    Directory of Open Access Journals (Sweden)

    Matthew J. Penn

    2014-05-01

    Full Text Available The infrared solar spectrum contains a wealth of physical data about our Sun, and is explored using modern detectors and technology with new ground-based solar telescopes. The scientific motivation behind exploring these wavelengths is presented, along with a brief look at the rich history of observations here. Several avenues of solar physics research exploiting and benefiting from observations at infrared wavelengths from roughly 1000 nm to 12 400 nm are discussed, and the instrument and detector technology driving this research is briefly summarized. Finally, goals for future work at infrared wavelengths are presented in conjunction with ground and space-based observations.

  17. Advanced Filtering Techniques Applied to Spaceflight Project

    Data.gov (United States)

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

  18. Shunt Active Filter in Damping Harmonics Propagation

    Directory of Open Access Journals (Sweden)

    BERBAOUI, B.

    2010-08-01

    Full Text Available This paper deals with a hybrid shunt active power filter applied on 500 kV HVDC, after a description of the causes and effects harmonic pollution which may damage equipments and interrupt electric power customers service; in this paper we present the deferent solutions of this problem among one has to study the two most recent types of filtering: passive and hybrid filter. The hybrid filter consists of active filter connected in shunt with passive filter. The hybrid shunt active filter proposed is based on three levels PWM inverter and characterized by detecting the harmonic current flowing into the passive filter and controlled by notch algorithm. This structure has been applied on a test HVDC power system, is presented as a technical solution makes it possible to eliminate the disadvantages from passive filtering, and also economic price of active filtering part. The simulation results justified the effectiveness of this type of filter face of the classic passive filter.

  19. Nanophotonic filters for digital imaging

    Science.gov (United States)

    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.

  20. Simulasi Perancangan Filter Analog dengan Respon Chebyshev

    Directory of Open Access Journals (Sweden)

    RUSTAMAJI RUSTAMAJI

    2016-02-01

    Full Text Available Abstrak Dalam suatu sistem komunikasi penggunaan rangkaian filter sangat penting. Salah satu cara untuk memudahkan dalam perancangan sebuah filter dilakukanlah teknik simulasi. Penelitian ini bertujuan untuk merancang simulasi yang menghasilkan respon filter jenis chebyshev serta menghasilkan nilai komponen induktor (L dan kapasitor (C yang dibutuhkan untuk merangkai filter. Simulasi yang dirancang pada penelitian ini menggunakan Graphical User Interface (GUI. Dari simulasi yang dilakukan, didapatkan respon Chebyshev pada low pass filter, high pass filter, band pass filter, dan band stop filter sudah sesuai dengan input yang dimasukkan ke dalam parameter program dan sesuai dengan teori respon filter Chebyshev. Hasil Simulasi dari rangkaian band pass filter dan band stop filter dengan menggunakan Electronic Workbench (EWB, menunjukkan respon dengan pergeseran frekuensi sebesar 0,1 kHz lebih tinggi dari frekuensi yang diharapkan. Kata Kunci :filter, Chebyshev, band, respon frekuensi.   Abstract On communication system using filter is very important. One way to simplify the design of filter undertaken a simulation technique. This research aims to design a simulation that generates the filter response of chebyshev and generate the value component of the inductor (L and capacitor (C that needed for constructing the filter. This Simulation using Graphical User Interface (GUI. From result simulation, response in low pass filter, high pass filter, band pass filter, band stop filter and is in compliance with the input entered into the program and in accordance with the theory of Chebyshev filter response. The simulation of the band pass filter and bands stop filter by using electronic workbench ( EWB , show a response with shifts frequency of 0.1 khz higher than frequency expected.   Keywords: filter, Chebyshev, band, frequency respons

  1. Pragmatic circuits signals and filters

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

  2. Tunable Imaging Filters in Astronomy

    CERN Document Server

    Bland-Hawthorn, J

    2000-01-01

    While tunable filters are a recent development in night time astronomy, they have long been used in other physical sciences, e.g. solar physics, remote sensing and underwater communications. With their ability to tune precisely to a given wavelength using a bandpass optimized for the experiment, tunable filters are already producing some of the deepest narrowband images to date of astrophysical sources. Furthermore, some classes of tunable filters can be used in fast telescope beams and therefore allow for narrowband imaging over angular fields of more than a degree over the sky.

  3. Simplified design of filter circuits

    CERN Document Server

    Lenk, John

    1999-01-01

    Simplified Design of Filter Circuits, the eighth book in this popular series, is a step-by-step guide to designing filters using off-the-shelf ICs. The book starts with the basic operating principles of filters and common applications, then moves on to describe how to design circuits by using and modifying chips available on the market today. Lenk's emphasis is on practical, simplified approaches to solving design problems.Contains practical designs using off-the-shelf ICsStraightforward, no-nonsense approachHighly illustrated with manufacturer's data sheets

  4. Properties of ceramic candle filters

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-06-01

    The mechanical integrity of ceramic filter elements is a key issue for hot gas cleanup systems. To meet the demands of the advanced power systems, the filter components must sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. They must also survive the various mechanical loads associated with handling and assembly, normal operation, and process upsets. For near-term filter systems, these elements must survive at operating temperatures of 1650{degrees}F for three years.

  5. Nonlinear Filtering and Approximation Techniques

    Science.gov (United States)

    1988-10-01

    e par des iquations de dimension finie, les 6quations du filtre de Kalman : X +h~pklk Xk=(1 + bAt).kk..I + e2+h2 pl_(k - h( + b~t)Xk-... (6 -kIj (1...Equation. 3. Piecewise Linear Filtering with Small Observation Noise. 4. Filtres Approches pour un Probleme de Fitrage Nonlineaire Discretise avec Petit...finite dimensional solution, namely the Kalman filter (which is the extended Kalman filter for (0.1) ). The above considerations tend to indicate that

  6. 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

  7. Omnispectravision Optimizes True Color Display Of Infrared Imagery

    Science.gov (United States)

    Pollock, D. H.; Stapleton, J. J.

    1981-07-01

    Omnispectravision is a real time electro-optic system that mimics and expands the ability of humans to receive radiant energy at multiple invisible wavelengths and convert it into visual stimuli thru the effect of display energy upon the photosensitive recePtors. A novel trichroic silicon mirror generates a composite plus two samples of three discrete infrared colors across a single InSb/PV detector array. The prototype digital scan con-verter with a recursive filter synchronously samples the multiplexed in-line detectors and transversal filters transform the λ3 > λ2 > λl infrared signals dispersed along the TV scan lines into -R-G-B (minus red, green, blue respectively).

  8. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence.

    Science.gov (United States)

    Kelly, David; Majda, Andrew J; Tong, Xin T

    2015-08-25

    The ensemble Kalman filter and ensemble square root filters are data assimilation methods used to combine high-dimensional, nonlinear dynamical models with observed data. Ensemble methods are indispensable tools in science and engineering and have enjoyed great success in geophysical sciences, because they allow for computationally cheap low-ensemble-state approximation for extremely high-dimensional turbulent forecast models. From a theoretical perspective, the dynamical properties of these methods are poorly understood. One of the central mysteries is the numerical phenomenon known as catastrophic filter divergence, whereby ensemble-state estimates explode to machine infinity, despite the true state remaining in a bounded region. In this article we provide a breakthrough insight into the phenomenon, by introducing a simple and natural forecast model that transparently exhibits catastrophic filter divergence under all ensemble methods and a large set of initializations. For this model, catastrophic filter divergence is not an artifact of numerical instability, but rather a true dynamical property of the filter. The divergence is not only validated numerically but also proven rigorously. The model cleanly illustrates mechanisms that give rise to catastrophic divergence and confirms intuitive accounts of the phenomena given in past literature.

  9. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence

    Science.gov (United States)

    Kelly, David; Majda, Andrew J.; Tong, Xin T.

    2015-01-01

    The ensemble Kalman filter and ensemble square root filters are data assimilation methods used to combine high-dimensional, nonlinear dynamical models with observed data. Ensemble methods are indispensable tools in science and engineering and have enjoyed great success in geophysical sciences, because they allow for computationally cheap low-ensemble-state approximation for extremely high-dimensional turbulent forecast models. From a theoretical perspective, the dynamical properties of these methods are poorly understood. One of the central mysteries is the numerical phenomenon known as catastrophic filter divergence, whereby ensemble-state estimates explode to machine infinity, despite the true state remaining in a bounded region. In this article we provide a breakthrough insight into the phenomenon, by introducing a simple and natural forecast model that transparently exhibits catastrophic filter divergence under all ensemble methods and a large set of initializations. For this model, catastrophic filter divergence is not an artifact of numerical instability, but rather a true dynamical property of the filter. The divergence is not only validated numerically but also proven rigorously. The model cleanly illustrates mechanisms that give rise to catastrophic divergence and confirms intuitive accounts of the phenomena given in past literature. PMID:26261335

  10. Optically triggered infrared photodetector.

    Science.gov (United States)

    Ramiro, Íñigo; Martí, Antonio; Antolín, Elisa; López, Esther; Datas, Alejandro; Luque, Antonio; Ripalda, José M; González, Yolanda

    2015-01-14

    We demonstrate a new class of semiconductor device: the optically triggered infrared photodetector (OTIP). This photodetector is based on a new physical principle that allows the detection of infrared light to be switched ON and OFF by means of an external light. Our experimental device, fabricated using InAs/AlGaAs quantum-dot technology, demonstrates normal incidence infrared detection in the 2-6 μm range. The detection is optically triggered by a 590 nm light-emitting diode. Furthermore, the detection gain is achieved in our device without an increase of the noise level. The novel characteristics of OTIPs open up new possibilities for third generation infrared imaging systems ( Rogalski, A.; Antoszewski, J.; Faraone, L. J. Appl. Phys. 2009, 105 (9), 091101).

  11. Infrared processing of foods

    Science.gov (United States)

    Infrared (IR) processing of foods has been gaining popularity over conventional processing in several unit operations, including drying, peeling, baking, roasting, blanching, pasteurization, sterilization, disinfection, disinfestation, cooking, and popping . It has shown advantages over conventional...

  12. e-FILTERS OF MS-ALGEBRAS

    Institute of Scientific and Technical Information of China (English)

    M.Sambasiva RAO

    2013-01-01

    The notion of e-filters is introduced in an MS-algebra and characterized.The concept of D-filters is introduced and a set of equivalent conditions under which every D-filter is an e-filter are given.The properties of the space of all prime e-filters of an MS-algebra are observed.The concept of D-prime filters is introduced and then a set of equivalent conditions are derived for a prime e-filter to become a D-prime filter in topological terms.

  13. Digital filtering: background and tutorial for psychophysiologists.

    Science.gov (United States)

    Cook, E W; Miller, G A

    1992-05-01

    Digital filtering offers more to psychophysiologists than is commonly appreciated. An introduction is offered here to foster the explicit design and use of digital filters. Because of considerable confusion in the literature about terminology important to both analog and digital filtering, basic concepts are reviewed and clarified. Because some time series concepts are fundamental to digital filtering, these are also presented. Examples of filters commonly used in psychophysiology are given, and procedures are presented for the design and use of one type of digital filter. Properties of some types of digital filters are described, and the relative advantages of simple analog and digital filters are discussed.

  14. Microplastic in a macro filter feeder: Humpback whale Megaptera novaeangliae.

    Science.gov (United States)

    Besseling, E; Foekema, E M; Van Franeker, J A; Leopold, M F; Kühn, S; Bravo Rebolledo, E L; Heße, E; Mielke, L; IJzer, J; Kamminga, P; Koelmans, A A

    2015-06-15

    Marine filter feeders are exposed to microplastic because of their selection of small particles as food source. Baleen whales feed by filtering small particles from large water volumes. Macroplastic was found in baleen whales before. This study is the first to show the presence of microplastic in intestines of a baleen whale (Megaptera novaeangliae). Contents of its gastrointestinal tract were sieved, dissolved in 10% potassium hydroxide and washed. From the remaining dried material, potential synthetic polymer particles were selected based on density and appearance, and analysed by Fourier transform infrared (FTIR) spectroscopy. Several polymer types (polyethylene, polypropylene, polyvinylchloride, polyethylene terephthalate, nylon) were found, in varying particle shapes: sheets, fragments and threads with a size of 1mm to 17cm. This diversity in polymer types and particle shapes, can be interpreted as a representation of the varying characteristics of marine plastic and the unselective way of ingestion by M. novaeangliae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Soliton filtering from a supercontinuum: a tunable femtosecond pulse source

    Energy Technology Data Exchange (ETDEWEB)

    Licea-Rodriguez, Jacob; Rangel-Rojo, Raul [Centro de Investigacion CientIfica y de Educacion Superior de Ensenada, Apartado Postal 2732, Ensenada B.C., 22860 (Mexico); Garay-Palmett, Karina, E-mail: rrangel@cicese.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico DF. 04510 (Mexico)

    2011-01-01

    In this article we report experimental results related with the generation of a supercontinuum in a microstructured fiber, from which the soliton with the longest wavelength is filtered out of the continuum and is used to construct a tunable ultrashort pulses source by varying the pump power. Pulses of an 80 fs duration (FWHM) from a Ti:sapphire oscillator were input into a 2 m long fiber to generate the continuum. The duration of the solitons at the fiber output was preserved by using a zero dispersion filtering system, which selected the longest wavelength soliton, while avoiding temporal spreading of the solitons. We present a complete characterization of the filtered pulses that are continuously tunable in the 850-1100 nm range. We also show that the experimental results have a qualitative agreement with theory. An important property of the proposed near-infrared pulsed source is that the soliton pulse energies obtained after filtering are large enough for applications in nonlinear microscopy.

  16. Infrared spectra of lunar soils. [using a Michelson interferometer

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.

    1979-01-01

    Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

  17. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  18. Matched Spectral Filter Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — OPTRA proposes the development of an imaging spectrometer for greenhouse gas and volcanic gas imaging based on matched spectral filtering and compressive imaging....

  19. Integrated Spatial Filter Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial...

  20. Biometric verification with correlation filters

    Science.gov (United States)

    Vijaya Kumar, B. V. K.; Savvides, Marios; Xie, Chunyan; Venkataramani, Krithika; Thornton, Jason; Mahalanobis, Abhijit

    2004-01-01

    Using biometrics for subject verification can significantly improve security over that of approaches based on passwords and personal identification numbers, both of which people tend to lose or forget. In biometric verification the system tries to match an input biometric (such as a fingerprint, face image, or iris image) to a stored biometric template. Thus correlation filter techniques are attractive candidates for the matching precision needed in biometric verification. In particular, advanced correlation filters, such as synthetic discriminant function filters, can offer very good matching performance in the presence of variability in these biometric images (e.g., facial expressions, illumination changes, etc.). We investigate the performance of advanced correlation filters for face, fingerprint, and iris biometric verification.

  1. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  2. Near-Infrared Hyper-spectral Image Analysis of Astaxanthin Concentration in Fish Feed Coating

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Ersbøll, Bjarne Kjær; Kobayashi, K.;

    2012-01-01

    The aim of this study was to investigate the possibility of predicting concentration levels of synthetic astaxanthin coating of aquaculture feed pellets by hyper-spectral image analysis in the near infra-red (NIR) range and optical filter design. The imaging devices used were a Videometer...... for prediction of the concentration level. The results show that it is possible to predict the level of synthetic astaxanthin coating using either hyper-spectral imaging or three bandpass filters (BPF)....

  3. Spatio-temporal characterization of mid-infrared laser pulses with spatially encoded spectral shearing interferometry

    CERN Document Server

    Witting, Tobias; Tisch, John W G; Marangos, Jonathan P

    2012-01-01

    We report on the spatially resolved full amplitude and phase characterization of mid-infrared high intensity laser pulses generated in a three stage OPA. We use a spatially-encoded arrangement (SEA-)SPIDER with spectral filters for ancilla generation for spatially resolved characterization. Using five interchangeable filter sets we are able to characterize pulses from 1 to 2{\\mu}m with one single device with minimal adjustments.

  4. Stochastic processes and filtering theory

    CERN Document Server

    Jazwinski, Andrew H

    2007-01-01

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

  5. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  6. Optical fiber gas sensing system based on FBG filtering

    Science.gov (United States)

    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%.

  7. Q value analysis of microwave photonic filters

    Institute of Scientific and Technical Information of China (English)

    Lina ZHOU; Xinliang ZHANG; Enming XU

    2009-01-01

    This paper first presents the fundamental principles of the microwave photonic filters.As an example to explain how to implement a microwave photonic filter, a specific finite impulse response (FIR) filter is illustrated.Next, the Q value of the microwave photonic filters is analyzed theoretically, and methods around how to gain high Q value are discussed.Then,divided into FIR filter, first-order infinite impulse response (IIR) filter, and multi-order IIR filter, several novel microwave photonic filters with high Q value are listed and compared.The technical difficulties to get high Q value in first-order IIR filter and multi-order IIR filter are analyzed concretely.Finally, in order to gain higher Q value, a multi-order IIR microwave photonic filter that easily extends its order is presented and discussed.

  8. Characterizing Debris in the Infrared with UKIRT

    Science.gov (United States)

    Lederer, S. M.; Jah, M.; Kendrick, R.; Buckalew, B.; Frith, J. M.; Cowardin, H. M.; Bold, M.

    2015-01-01

    The United Kingdom Infrared Telescope (UKIRT) has been a major asset for the NASA Orbital Debris Program Office (OPDO) since March, 2014. With the UKIRT current contract coming to an end at the finish of FY15, there is a golden opportunity for this community to fund and gain access to UKIRT as an SSA asset through HCAR (Hawaii Center for Astronautics Research). UKIRT is the only telescope on Mauna Kea dedicated to infrared bands. Spectral coverage ranges from the near- (0.8-5µm) to the mid- to far-infrared (8-25 micrometer) regime. To date, debris observations have been collected with three instruments. Near-Infrared photometry with ZYJHK filters has been obtained with the Wide Field Camera (WFCam). Near-Infrared (1-2.5 micrometer) spectra are the focus of observations taken with the UKIRT Imager SpecTrometer (UIST). And Michelle (Mid Infrared escCHELLE) is a thermal imager-spectrometer designed for the 8-25 micrometer regime. With 35% of the telescope time allocated to ODPO, a very steady stream of data has been collected on a variety of debris targets using all the above instrumentation. Initial results from WFCam were discussed at AMOS and NISOI including analyses on IDCSPs, the MSG cooler and baffle covers. The cylindrical HS-376 buses were the focus of recent WFCam runs. Summary analyses of these works will be presented. Focus will be given to initial results of the data collected with the Cassegrain instruments, UIST and Michelle. UIST spectra were collected in September 2014, March and April 2015. Targets included a suite of HS-376 buses, well suited to investigate the signatures of blue solar panels; several dead satellites with solar array wings; Titan 3C transtage debris; the CTA Array cover, and others. In addition, Michelle mid-IR photometry was collected on a select few objects during the April 2015 run. Using WFCam, UIST and Michelle the Lockheed Martin has been observing operational satellites in the near- mid and far-infrared regime in an attempt

  9. Filtering algorithms using shiftable kernels

    CERN Document Server

    Chaudhury, Kunal Narayan

    2011-01-01

    It was recently demonstrated in [4][arxiv:1105.4204] that the non-linear bilateral filter \\cite{Tomasi} can be efficiently implemented using an O(1) or constant-time algorithm. At the heart of this algorithm was the idea of approximating the Gaussian range kernel of the bilateral filter using trigonometric functions. In this letter, we explain how the idea in [4] can be extended to few other linear and non-linear filters [18,21,2]. While some of these filters have received a lot of attention in recent years, they are known to be computationally intensive. To extend the idea in \\cite{Chaudhury2011}, we identify a central property of trigonometric functions, called shiftability, that allows us to exploit the redundancy inherent in the filtering operations. In particular, using shiftable kernels, we show how certain complex filtering can be reduced to simply that of computing the moving sum of a stack of images. Each image in the stack is obtained through an elementary pointwise transform of the input image. Thi...

  10. A taxonomy fuzzy filtering approach

    Directory of Open Access Journals (Sweden)

    Vrettos S.

    2003-01-01

    Full Text Available Our work proposes the use of topic taxonomies as part of a filtering language. Given a taxonomy, a classifier is trained for each one of its topics. The user is able to formulate logical rules combining the available topics, e.g. (Topic1 AND Topic2 OR Topic3, in order to filter related documents in a stream. Using the trained classifiers, every document in the stream is assigned a belief value of belonging to the topics of the filter. These belief values are then aggregated using logical operators to yield the belief to the filter. In our study, Support Vector Machines and Naïve Bayes classifiers were used to provide topic probabilities. Aggregation of topic probabilities based on fuzzy logic operators was found to improve filtering performance on the Renters text corpus, as compared to the use of their Boolean counterparts. Finally, we deployed a filtering system on the web using a sample taxonomy of the Open Directory Project.

  11. Photonic crystal-enhanced quantum dot infrared photodetectors

    Science.gov (United States)

    McKerracher, I. R.; Hattori, H. T.; Fu, L.; Tan, H. H.; Jagadish, C.

    2008-08-01

    Quantum dot infrared photodetectors (QDIPs) promise improved performance over existing technologies in the form of higher temperature operation and normal-incidence detection. Variation in the size of self-assembled quantum dots leads to a broadened spectral response, which is undesirable for multi-color detection. Photonic crystal slabs can filter the transmission of normally-incident light using Fano resonances, and thus may be integrated with QDIPs to create a narrowband detector. Finite-difference time-domain simulations were used to optimize such a filter for QDIPs grown by metal-organic chemical vapor deposition. The simulations predict that the integrated detector could show up to 76% decrease in the detector linewidth, with a tunable peak location. These devices were then fabricated by standard optical lithography, however the spectral width of the integrated device was similar to that of the unfiltered QDIP. This is attributed to imperfections in the filter, so alternative fabrication methods are discussed for future processing.

  12. The Infrared Hunter

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2 This image composite compares infrared and visible views of the famous Orion nebula and its surrounding cloud, an industrious star-making region located near the hunter constellation's sword. The infrared picture is from NASA's Spitzer Space Telescope, and the visible image is from the National Optical Astronomy Observatory, headquartered in Tucson, Ariz. In addition to Orion, two other nebulas can be seen in both pictures. The Orion nebula, or M42, is the largest and takes up the lower half of the images; the small nebula to the upper left of Orion is called M43; and the medium-sized nebula at the top is NGC 1977. Each nebula is marked by a ring of dust that stands out in the infrared view. These rings make up the walls of cavities that are being excavated by radiation and winds from massive stars. The visible view of the nebulas shows gas heated by ultraviolet radiation from the massive stars. Above the Orion nebula, where the massive stars have not yet ejected much of the obscuring dust, the visible image appears dark with only a faint glow. In contrast, the infrared view penetrates the dark lanes of dust, revealing bright swirling clouds and numerous developing stars that have shot out jets of gas (green). This is because infrared light can travel through dust, whereas visible light is stopped short by it. The infrared image shows light captured by Spitzer's infrared array camera. Light with wavelengths of 8 and 5.8 microns (red and orange) comes mainly from dust that has been heated by starlight. Light of 4.5 microns (green) shows hot gas and dust; and light of 3.6 microns (blue) is from starlight.

  13. Near-infrared imaging spectrometer onboard NEXTSat-1

    Science.gov (United States)

    Jeong, Woong-Seob; Park, Sung-Joon; Moon, Bongkon; Lee, Dae-Hee; Pyo, Jeonghyun; Park, Won-Kee; Park, Youngsik; Kim, Il-Joong; Ko, Kyeongyeon; Lee, Dukhang; Kim, Min Gyu; Kim, Minjin; Ko, Jongwan; Shin, Goo-Hwan; Chae, Jangsoo; Matsumoto, Toshio

    2016-07-01

    The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the first next generation of small satellite (NEXTSat-1) in Korea. The spectro-photometric capability in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the NISS will perform the large areal imaging spectroscopic survey for astronomical objects and low background regions. We have paid careful attention to reduce the volume and to increase the total throughput. The newly implemented off-axis optics has a wide field of view (2° x 2°) and a wide wavelength range from 0.9 to 3.8μm. The mechanical structure is designed to consider launching conditions and passive cooling of the telescope. The compact dewar after relay-lens module is to operate the infrared detector and spectral filters at 80K stage. The independent integration of relay-lens part and primary-secondary mirror assembly alleviates the complex alignment process. We confirmed that the telescope and the infrared sensor can be cooled down to around 200K and 80K, respectively. The engineering qualification model of the NISS was tested in the space environment including the launch-induced vibration and shock. The NISS will be expected to demonstrate core technologies related to the development of the future infrared space telescope in Korea.

  14. Tunable Light Filtering in a Bragg Mirror/Heavily-Doped Semiconducting Nanocrystal Composite

    CERN Document Server

    Kriegel, Ilka

    2014-01-01

    Tunable light filters are critical components for many optical applications in which light in-coupling, out-coupling or rejection is crucial, such as lasing, sensing, photovoltaics and information and communication technology. For this purpose, Bragg mirrors, band-pass filters with high reflectivity represent good candidates. However, their optical characteristics are determined at the stage of fabrication. Heavily doped semiconductor nanocrystals (NCs) on the other hand deliver a high degree of optical tunability through the active modulation of their carrier density ultimately influencing their plasmonic absorption properties. Here, we propose the design of a tunable light filter composed of a Bragg mirror and a layer of plasmonic semiconductor NCs. We demonstrate that the filtering properties of the coupled device can be tuned to cover a wide range of frequencies from the visible to the near infrared (vis-NIR) spectral region when employing varying carrier densities. As tunable component we implemented a d...

  15. Evaluating document filtering systems over time

    NARCIS (Netherlands)

    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

  16. CPHD filter derivation for extended targets

    CERN Document Server

    Orguner, Umut

    2010-01-01

    This document derives the CPHD filter for extended targets. Only the update step is derived here. Target generated measurements, false alarms and prior are all assumed to be independent identically distributed cluster processes. We also prove here that the derived CPHD filter for extended targets reduce to PHD filter for extended targets and CPHD filter for standard targets under suitable assumptions.

  17. Dynamic programming algorithm for detecting dim infrared moving targets

    Science.gov (United States)

    He, Lisha; Mao, Liangjing; Xie, Lijun

    2009-10-01

    Infrared (IR) target detection is a key part of airborne infrared weapon system, especially the detection of poor dim moving IR target embedded in complex context. This paper presents an improved Dynamic Programming (DP) algorithm in allusion to low Signal to Noise Ratio (SNR) infrared dim moving targets under cluttered context. The algorithm brings the dim target to prominence by accumulating the energy of pixels in the image sequence, after suppressing the background noise with a mathematical morphology preprocessor. As considering the continuity and stabilization of target's energy and forward direction, this algorithm has well solved the energy scattering problem that exists in the original DP algorithm. An effective energy segmentation threshold is given by a Contrast-Limited Adaptive Histogram Equalization (CLAHE) filter with a regional peak extraction algorithm. Simulation results show that the improved DP tracking algorithm performs well in detecting poor dim targets.

  18. Infrared medical image visualization and anomalies analysis method

    Science.gov (United States)

    Gong, Jing; Chen, Zhong; Fan, Jing; Yan, Liang

    2015-12-01

    Infrared medical examination finds the diseases through scanning the overall human body temperature and obtaining the temperature anomalies of the corresponding parts with the infrared thermal equipment. In order to obtain the temperature anomalies and disease parts, Infrared Medical Image Visualization and Anomalies Analysis Method is proposed in this paper. Firstly, visualize the original data into a single channel gray image: secondly, turn the normalized gray image into a pseudo color image; thirdly, a method of background segmentation is taken to filter out background noise; fourthly, cluster those special pixels with the breadth-first search algorithm; lastly, mark the regions of the temperature anomalies or disease parts. The test is shown that it's an efficient and accurate way to intuitively analyze and diagnose body disease parts through the temperature anomalies.

  19. Filter transient response to EEG waveforms.

    Science.gov (United States)

    Shirakawa, S; Smith, J R; Azumi, K

    1987-01-01

    The response of two types of linear filters to sinusoidal bursts was calculated to demonstrate how filters can distort EEG waveforms. Results show that the wider the filter bandwidth the less is the distortion, and for a given bandwidth, the higher the filter order the greater the distortion. The response of a linear phase filter was also calculated to demonstrate that this type of filter can also cause waveform distortion, although it is normally less than that caused by Butterworth, Tchebychev and elliptic filters.

  20. Novel Simplex Unscented Transform and Filter

    Institute of Scientific and Technical Information of China (English)

    Wan-Chun Li; Ping Wei; Xian-Ci Xiao

    2008-01-01

    In this paper, a new simplex unscented transform (UT) based Schmidt orthogonal algorithm and a new filter method based on this transform are proposed. This filter has less computation consumption than UKF (unscented Kalman filter), SUKF (simplex unscented Kalman filter) and EKF (extended Kalman filter). Computer simulation shows that this filter has the same performance as UKF and SUKF, and according to the analysis of the computational requirements of EKF, UKF and SUKF, this filter has preferable practicality value. Finally, the appendix shows the efficiency for this UT.

  1. Digital notch filter based active damping for LCL filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin

    2015-01-01

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

  2. 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.

  3. Numerical simulation of large fabric filter

    Science.gov (United States)

    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.

  4. Shielded multi-stage EMI noise filter

    Energy Technology Data Exchange (ETDEWEB)

    Kisner, Roger Allen; Fugate, David Lee

    2016-11-08

    Electromagnetic interference (EMI) noise filter embodiments and methods for filtering are provided herein. EMI noise filters include multiple signal exclusion enclosures. The multiple signal exclusion enclosures contain filter circuit stages. The signal exclusion enclosures can attenuate noise generated external to the enclosures and/or isolate noise currents generated by the corresponding filter circuits within the enclosures. In certain embodiments, an output of one filter circuit stage is connected to an input of the next filter circuit stage. The multiple signal exclusion enclosures can be chambers formed using conductive partitions to divide an outer signal exclusion enclosure. EMI noise filters can also include mechanisms to maintain the components of the filter circuit stages at a consistent temperature. For example, a metal base plate can distribute heat among filter components, and an insulating material can be positioned inside signal exclusion enclosures.

  5. Shielded multi-stage EMI noise filter

    Science.gov (United States)

    Kisner, Roger Allen; Fugate, David Lee

    2016-11-08

    Electromagnetic interference (EMI) noise filter embodiments and methods for filtering are provided herein. EMI noise filters include multiple signal exclusion enclosures. The multiple signal exclusion enclosures contain filter circuit stages. The signal exclusion enclosures can attenuate noise generated external to the enclosures and/or isolate noise currents generated by the corresponding filter circuits within the enclosures. In certain embodiments, an output of one filter circuit stage is connected to an input of the next filter circuit stage. The multiple signal exclusion enclosures can be chambers formed using conductive partitions to divide an outer signal exclusion enclosure. EMI noise filters can also include mechanisms to maintain the components of the filter circuit stages at a consistent temperature. For example, a metal base plate can distribute heat among filter components, and an insulating material can be positioned inside signal exclusion enclosures.

  6. Infrared source test

    Energy Technology Data Exchange (ETDEWEB)

    Ott, L.

    1994-11-15

    The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

  7. Infrared observations of comets

    Science.gov (United States)

    Hanner, Martha S.

    1991-01-01

    Selected comets are observed in the near infrared (1 to 2.2 micron) and thermal infrared (3.5 to 20 micron) with the NASA Infrared Telescope Facility (IRTF) and other telescopes as appropriate, in order to characterize the physical properties of the dust grains; their composition, size distribution, emissivity, and albedo. Systematic variations in these properties among comets are looked for, in order to understand the heterogeneity of comet nuclei. Spectrophotometry of the 10 micron silicate emission feature is particularly emphasized. The rate of dust production from the nucleus and its temporal variability are also determined. Knowledge of the dust environment is essential to S/C design and mission planning for NASA's CRAF mission.

  8. Variable waveband infrared imager

    Science.gov (United States)

    Hunter, Scott R.

    2013-06-11

    A waveband imager includes an imaging pixel that utilizes photon tunneling with a thermally actuated bimorph structure to convert infrared radiation to visible radiation. Infrared radiation passes through a transparent substrate and is absorbed by a bimorph structure formed with a pixel plate. The absorption generates heat which deflects the bimorph structure and pixel plate towards the substrate and into an evanescent electric field generated by light propagating through the substrate. Penetration of the bimorph structure and pixel plate into the evanescent electric field allows a portion of the visible wavelengths propagating through the substrate to tunnel through the substrate, bimorph structure, and/or pixel plate as visible radiation that is proportional to the intensity of the incident infrared radiation. This converted visible radiation may be superimposed over visible wavelengths passed through the imaging pixel.

  9. A biological oil adsorption filter

    Energy Technology Data Exchange (ETDEWEB)

    Pasila, A. [University of Helsinki (Finland). Dept. of Agricultural Engineering and Household Technology

    2005-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  10. A biological oil adsorption filter.

    Science.gov (United States)

    Pasila, Antti

    2004-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore.

  11. GPU Accelerated Vector Median Filter

    Science.gov (United States)

    Aras, Rifat; Shen, Yuzhong

    2011-01-01

    Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

  12. Automated Integrated Analog Filter Design Issues

    OpenAIRE

    2015-01-01

    An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is t...

  13. Optimal Nonlinear Filter for INS Alignment

    Institute of Scientific and Technical Information of China (English)

    赵瑞; 顾启泰

    2002-01-01

    All the methods to handle the inertial navigation system (INS) alignment were sub-optimal in the past. In this paper, particle filtering (PF) as an optimal method is used for solving the problem of INS alignment. A sub-optimal two-step filtering algorithm is presented to improve the real-time performance of PF. The approach combines particle filtering with Kalman filtering (KF). Simulation results illustrate the superior performance of these approaches when compared with extended Kalman filtering (EKF).

  14. Multiplier-free filters for wideband SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2001-01-01

    This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results ar...... are presented in terms of filter complexity and performance. One filter has been coded in VHDL and preliminary results indicate that the filter can meet a 2 GHz input sample rate....

  15. Evolving Information Filtering for Personalized Information Service

    Institute of Scientific and Technical Information of China (English)

    田范江; 李丛蓉; 王鼎兴

    2001-01-01

    Information filtering (IF) systems are important for personalized information service. However, most current IF systems suffer from low quality and long training time. In this paper, a refined evolving information filtering method is presented. This method describes user's information need from multi-aspects and improves filtering quality through a process like natural selection. Experimental result shows this method can shorten training time, improve filtering quality, and reduce the relevance between filtering results and training sequence.

  16. Powerful infrared emitting diodes

    Directory of Open Access Journals (Sweden)

    Kogan L. M.

    2012-02-01

    Full Text Available Powerful infrared LEDs with emission wavelength 805 ± 10, 870 ± 20 and 940 ± 10 nm developed at SPC OED "OPTEL" are presented in the article. The radiant intensity of beam diode is under 4 W/sr in the continuous mode and under 100 W/sr in the pulse mode. The radiation power of wide-angle LEDs reaches 1 W in continuous mode. The external quantum efficiency of emission IR diodes runs up to 30%. There also has been created infrared diode modules with a block of flat Fresnel lenses with radiant intensity under 70 W/sr.

  17. The Infrared Handbook

    Science.gov (United States)

    1978-01-01

    ero»m Soati I ö I 1 11 iilllillililllllllllllfllllllll § e I c V f{ ml OPEN-CYCLE, EXPENDABLE COOLING SYSTEMS 15-11 Gas Dryer and Filter...specular reflector, the warning signal will be a sinusoid-so the conditions of Marcum hold. For targets such as a tumbling flat plate, the signals

  18. Inferior vena cava filters in cancer patients: to filter or not to filter

    Directory of Open Access Journals (Sweden)

    Hikmat Abdel-Razeq

    2011-03-01

    Full Text Available Hikmat Abdel-Razeq1, Asem Mansour2, Yousef Ismael1, Hazem Abdulelah11Department of Internal Medicine, 2Department of Radiology, King Hussein Cancer Center, Amman, JordanPurpose: Cancer and its treatment are recognized risk factors for venous thromboembolism (VTE; active cancer accounts for almost 20% of all newly diagnosed VTE. Inferior vena cava (IVC filters are utilized to provide mechanical thromboprophylaxis to prevent pulmonary embolism (PE or to avoid bleeding from systemic anticoagulation in high-risk situations. In this report, and utilizing a case study, we will address the appropriate utilization of such filters in cancer patients.Methods: The case of a 43-year-old female patient with rectal cancer, who developed deep vein thrombosis following a complicated medical course, will be presented. The patient was anticoagulated with a low molecular weight heparin, but a few months later and following an episode of bleeding, an IVC filter was planned. Using the PubMed database, articles published in English language addressing issues related to IVC filters in cancer patients were accessed and will be presented.Results: Many recent studies questioned the need to insert IVC filters in advanced-stage cancer patients, particularly those whose anticipated survival is short and prevention of PE may be of little clinical benefit and could be a poor utilization of resources.Conclusion: Systemic anticoagulation can be safely offered for the majority of cancer patients. When the risk of bleeding or pulmonary embolism is high, IVC filters can be utilized. However, placement of such filters should take into consideration the stage of disease and life expectancy of such patients.Keywords: anticoagulation, bleeding, chemotherapy

  19. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Fadeyi, M.O.; Clausen, Geo

    2009-01-01

    (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters......As ventilation filters accumulate particles removed from the airstream, they become emitters of sensory pollutants that degrade indoor air quality. Previously we demonstrated that an F7 bag-type filter that incorporates activated carbon (a "combination filter") reduces this adverse effect compared...... to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had...

  20. Design of SVD/SGK Convolution Filters for Image Processing

    Science.gov (United States)

    1980-01-01

    of filters by transforming one-dimensional linear phase filters * into two-dimensional linear phase filters . By assuming that the prototype filter is a...linear phase filter , his algorithm transforms a one-dimensional filter h(u) into a two-dimensional filter W (u,v) by means of transformation given by...significance of their implementation of the designed filter is that a large two-dimensional convolution *A linear phase filter implies symmetry of the filter. 13

  1. Radiant zone heated particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  2. Applications of nonwoven filter media

    Energy Technology Data Exchange (ETDEWEB)

    1988-11-01

    The multi-client technical and marketing report, Nonwovens in Filtration (1987) World Wide, has been completed by Filter Media Consulting, Inc. According to this 450-page report, $818 million in sales worldwide in nonwoven filter media represents a substantial segment of the entire nonwoven market. This total is mainly roll goods with a few exceptions. Meltblown composites represent $108 million, 13% of the total, and is the fastest growing segment as compared to needled felts, dry formed, thermobonded, spunbonded, wet laid and other unique processes, all extensively covered in this report. Included are 20 filtration applications covered in 190 pages, such as baghouse and dust filtration, Torit-type cartridge filters, HEPA/ULPA filtration, and heating, ventilation and air conditioning. Major markets are addressed, and trends in different fields are highlighted throughout the report.

  3. Quantum Diffusion, Measurement and Filtering

    CERN Document Server

    Belavkin, V P

    1993-01-01

    A brief presentation of the basic concepts in quantum probability theory is given in comparison to the classical one. The notion of quantum white noise, its explicit representation in Fock space, and necessary results of noncommutative stochastic analysis and integration are outlined. Algebraic differential equations that unify the quantum non Markovian diffusion with continuous non demolition observation are derived. A stochastic equation of quantum diffusion filtering generalising the classical Markov filtering equation to the quantum flows over arbitrary *-algebra is obtained. A Gaussian quantum diffusion with one dimensional continuous observation is considered.The a posteriori quantum state difusion in this case is reduced to a linear quantum stochastic filter equation of Kalman-Bucy type and to the operator Riccati equation for quantum correlations. An example of continuous nondemolition observation of the coordinate of a free quantum particle is considered, describing a continuous collase to the statio...

  4. Composite Reflective Absorptive IR-Blocking Filters Embedded in Metamaterial Antireflection Coated Silicon

    Science.gov (United States)

    Munson, C. D.; Choi, S. K.; Coughlin, K. P.; McMahon, J. J.; Miller, K. H.; Page, L. A.; Wollack, E. J.

    2017-01-01

    Infrared (IR)-blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of patterned frequency-selective structures on silicon and a thin (2575 micron thick) absorptive composite based on powdered reststrahlen absorbing materials. For a 300 K blackbody, this combination reflects approximately 50% of the incoming light and blocks greater than.99.8% of the total power with negligible thermal gradients and excellent low-frequency transmission. This allows a reduction in the IR thermal loading to negligible levels in a single cold filter. These composite filters are fabricated on silicon substrates, which provide excellent thermal transport laterally through the filter and ensure that the entire area of the absorptive filter stays near the bath temperature. A metamaterial antireflection coating cut into these substrates reduces in-band reflections to below 1%, and the in-band absorption of the powder mix is below 1% for signal bands below 750 GHz. This type of filter can be directly incorporated into silicon refractive optical elements.

  5. Adaptive filtering prediction and control

    CERN Document Server

    Goodwin, Graham C

    2009-01-01

    Preface1. Introduction to Adaptive TechniquesPart 1. Deterministic Systems2. Models for Deterministic Dynamical Systems3. Parameter Estimation for Deterministic Systems4. Deterministic Adaptive Prediction5. Control of Linear Deterministic Systems6. Adaptive Control of Linear Deterministic SystemsPart 2. Stochastic Systems7. Optimal Filtering and Prediction8. Parameter Estimation for Stochastic Dynamic Systems9. Adaptive Filtering and Prediction10. Control of Stochastic Systems11. Adaptive Control of Stochastic SystemsAppendicesA. A Brief Review of Some Results from Systems TheoryB. A Summary o

  6. Summary of Martian Dust Filtering Challenges and Current Filter Development

    Science.gov (United States)

    O'Hara, William J., IV

    2017-01-01

    Traditional air particulate filtering in manned spaceflight (Apollo, Shuttle, ISS, etc.) has used cleanable or replaceable catch filters such as screens and High-Efficiency Particulate Arrestance (HEPA) filters. However, the human mission to Mars architecture will require a new approach. It is Martian dust that is the particulate of concern but the need also applies to particulates generated by crew. The Mars Exploration Program Analysis Group (MEPAG) high-lighted this concern in its Mars Science, Goals, Objectives, Investigations and Priorities document [7], by saying specifically that one high priority investigation will be to "Test ISRU atmospheric processing systems to measure resilience with respect to dust and other environmental challenge performance parameters that are critical to the design of a full-scale system." By stating this as high priority the MEPAG is acknowledging that developing and adequately verifying this capability is critical to success of a human mission to Mars. This architecture will require filtering capabilities that are highly reliable, will not restrict the flow path with clogging, and require little to no maintenance. This paper will summarize why this is the case, the general requirements for developing the technology, and the status of the progress made in this area.

  7. FPGA implementation of filtered image using 2D Gaussian filter

    Directory of Open Access Journals (Sweden)

    Leila kabbai

    2016-07-01

    Full Text Available Image filtering is one of the very useful techniques in image processing and computer vision. It is used to eliminate useless details and noise from an image. In this paper, a hardware implementation of image filtered using 2D Gaussian Filter will be present. The Gaussian filter architecture will be described using a different way to implement convolution module. Thus, multiplication is in the heart of convolution module, for this reason, three different ways to implement multiplication operations will be presented. The first way is done using the standard method. The second way uses Field Programmable Gate Array (FPGA features Digital Signal Processor (DSP to ensure and make fast the scalability of the effective FPGA resource and then to speed up calculation. The third way uses real multiplier for more precision and a the maximum uses of FPGA resources. In this paper, we compare the image quality of hardware (VHDL and software (MATLAB implementation using the Peak Signal-to-Noise Ratio (PSNR. Also, the FPGA resource usage for different sizes of Gaussian kernel will be presented in order to provide a comparison between fixed-point and floating point implementations.

  8. Infrared upconversion hyperspectral imaging

    DEFF Research Database (Denmark)

    Kehlet, Louis Martinus; Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin

    2015-01-01

    conversion process. From this, a sequence of monochromatic images in the 3.2-3.4 mu m range is generated. The imaged object consists of a standard United States Air Force resolution target combined with a polystyrene film, resulting in the presence of both spatial and spectral information in the infrared...

  9. The Dynamic Infrared Sky

    Science.gov (United States)

    Kasliwal, Mansi M.; SPIRITS (Spitzer InfraRed Intensive Transients Survey) Team

    2017-01-01

    The dynamic infrared sky is hitherto largely unexplored. I will present the SPitzer InfraRed Intensive Transients Survey (SPIRITS) --- a systematic search of 194 nearby galaxies within 30 Mpc, on timescales ranging between a week to a year, to a depth of 20 mag with Spitzer's IRAC camera. SPIRITS has already uncovered over 95 explosive transients and over 1200 strong variables. Of these, 37 infrared transients are especially interesting as they have no optical counterparts whatsoever even with deep limits from Keck and HST. Interpretation of these new discoveries may include (i) the birth of massive binaries that drive shocks in their molecular cloud, (ii) stellar mergers with dusty winds, (iii) 8--10 solar mass stars experiencing e-capture induced collapse in their cores, (iv) enshrouded supernovae, or (v) formation of stellar mass black holes. SPIRITS reveals that the infrared sky is not just as dynamic as the optical sky; it also provides access to unique, elusive signatures in stellar astrophysics.

  10. Infrared Thermometer (IRT) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    VR Morris

    2006-10-30

    The Infrared Thermometer (IRT) is a ground-based radiation pyrometer that provides measurements of the equivalent blackbody brightness temperature of the scene in its field of view. The downwelling version has a narrow field of view for measuring sky temperature and for detecting clouds. The upwelling version has a wide field of view for measuring the narrowband radiating temperature of the ground surface.

  11. Decoherence and infrared divergence

    Indian Academy of Sciences (India)

    J Kupsch

    2002-08-01

    The dynamics of a particle which is linearly coupled to a boson field is investigated. The boson field induces superselection rules for the momentum of the particle, if the field is infrared divergent. Thereby the Hamiltonian of the total system remains bounded from below.

  12. Particle Kalman Filtering: A Nonlinear Bayesian Framework for Ensemble Kalman Filters

    CERN Document Server

    Hoteit, Ibrahim; Pham, Dinh-Tuan

    2011-01-01

    This paper investigates an approximation scheme of the optimal nonlinear Bayesian filter based on the Gaussian mixture representation of the state probability distribution function. The resulting filter is similar to the particle filter, but is different from it in that, the standard weight-type correction in the particle filter is complemented by the Kalman-type correction with the associated covariance matrices in the Gaussian mixture. We show that this filter is an algorithm in between the Kalman filter and the particle filter, and therefore is referred to as the particle Kalman filter (PKF). In the PKF, the solution of a nonlinear filtering problem is expressed as the weighted average of an "ensemble of Kalman filters" operating in parallel. Running an ensemble of Kalman filters is, however, computationally prohibitive for realistic atmospheric and oceanic data assimilation problems. For this reason, we consider the construction of the PKF through an "ensemble" of ensemble Kalman filters (EnKFs) instead, ...

  13. Corundum-based transparent infrared absorbers

    KAUST Repository

    Schwingenschlögl, Udo

    2009-10-01

    Hypothetical corundum-based compounds are studied by electronic structure calculations. One quarter of the Al atoms in Al2O3 is replaced by a 3d transition metal from the M = Ti, ..., Zn (d1, ..., d9) series. Structure optimisations are performed for all the M-Al2O3 compounds and the electronic states are evaluated. Due to the M substitutes, narrow partially filled bands are formed at the Fermi energy. Beyond, for M = Ni and M = Cu the optical properties of Al2O3 in the visible range are conserved, while for M = Ti, ..., Co the systems form high accuracy optical filters. Since the compounds absorb the infrared radiation, the M = Ni and M = Cu systems are good candidates for heat-protective coatings. © 2009 Elsevier B.V. All rights reserved.

  14. Kalman Filtering with Real-Time Applications

    CERN Document Server

    Chui, Charles K

    2009-01-01

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

  15. A digital algorithm for spectral deconvolution with noise filtering and peak picking: NOFIPP-DECON

    Science.gov (United States)

    Edwards, T. R.; Settle, G. L.; Knight, R. D.

    1975-01-01

    Noise-filtering, peak-picking deconvolution software incorporates multiple convoluted convolute integers and multiparameter optimization pattern search. The two theories are described and three aspects of the software package are discussed in detail. Noise-filtering deconvolution was applied to a number of experimental cases ranging from noisy, nondispersive X-ray analyzer data to very noisy photoelectric polarimeter data. Comparisons were made with published infrared data, and a man-machine interactive language has evolved for assisting in very difficult cases. A modified version of the program is being used for routine preprocessing of mass spectral and gas chromatographic data.

  16. Preparation of Polyaniline/Filter-paper Composite for Removal of Coomassie Brilliant Blue

    DEFF Research Database (Denmark)

    Liu, Wanwan; Li, Xiaoqiang; Li, Mengjuan

    2015-01-01

    Polyaniline/filter-paper (PANI/FP) composite was prepared by in-situ polymerization of polyaniline onto filter-paper and subsequently evaluated for the removal of Coomassie brilliant blue (CBB) from aqueous solution. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier......-transform infrared (FTIR) spectroscopy were used to investigate the morphology and physicochemical properties of PANI/FP composite. Batch experimental results showed that the pH value and temperature could affect the removal capability of the PANUFP composite. Langmuir and Freundlich models were used to analyse...

  17. Real-time multi-sensor based vehicle detection using MINACE filters

    Science.gov (United States)

    Topiwala, Pankaj; Nehemiah, Avinash

    2007-04-01

    A system to detect vehicles (cars, trucks etc) in electro-optic (EO) and infrared (IR) imagery is presented. We present the use of the minimum noise and correlation (MINACE) distortion invariant filter (DIF) for this problem. The selection of the MINACE filter parameter c is automated using a training and validation set. A new set of correlation plane post processing methods that improve detection accuracies and reduce false alarms are presented. The system is tested on real life imagery of traffic in parking lots and roads obtained using a multi-sensor EO/IR platform.

  18. Metamaterial composite bandpass filter with an ultra-broadband rejection bandwidth of up to 240 terahertz

    DEFF Research Database (Denmark)

    Strikwerda, Andrew; Zalkovskij, Maksim; Lorenzen, Dennis Lund

    2014-01-01

    We present a metamaterial, consisting of a cross structure and a metal mesh filter, that forms a composite with greater functional bandwidth than any terahertz (THz) metamaterial to date. Metamaterials traditionally have a narrow usable bandwidth that is much smaller than common THz sources...... frequency (f) that is scalable from 0.86–8.51 THz, that highly extinguishes other frequencies up to >240 THz. The performance of these filters is demonstrated in experiment, using both air biased coherent detection and a Fourier transform infrared spectrometer (FTIR), as well as in simulation. We present...

  19. Diode Laser Velocity Measurements by Modulated Filtered Rayleigh Scattering

    Science.gov (United States)

    Mach, J. J.; Varghese, P. L.; Jagodzinski, J. J.

    1999-01-01

    The ability of solid-state lasers to be tuned in operating frequency at MHz rates by input current modulation, while maintaining a relatively narrow line-width, has made them useful for spectroscopic measurements. Their other advantages include low cost, reliability, durability, compact size, and modest power requirements, making them a good choice for a laser source in micro-gravity experiments in drop-towers and in flight. For their size, they are also very bright. In a filtered Rayleigh scattering (FRS) experiment, a diode laser can be used to scan across an atomic or molecular absorption line, generating large changes in transmission at the resonances for very small changes in frequency. The hyperfine structure components of atomic lines of alkali metal vapors are closely spaced and very strong, which makes such atomic filters excellent candidates for sensitive Doppler shift detection and therefore for high-resolution velocimetry. In the work we describe here we use a Rubidium vapor filter, and work with the strong D(sub 2) transitions at 780 nm that are conveniently accessed by near infrared diode lasers. The low power output of infrared laser diodes is their primary drawback relative to other laser systems commonly used for velocimetry. However, the capability to modulate the laser frequency rapidly and continuously helps mitigate this. Using modulation spectroscopy and a heterodyne detection scheme with a lock-in amplifier, one can extract sub-microvolt signals occurring at a specific frequency from a background that is orders of magnitude stronger. The diode laser modulation is simply achieved by adding a small current modulation to the laser bias current. It may also be swept repetitively in wavelength using an additional lower frequency current ramp.

  20. An algorithm used for quality criterion automatic measurement of band-pass filters and its device implementation

    Science.gov (United States)

    Liu, Qianshun; Liu, Yan; Yu, Feihong

    2013-08-01

    As a kind of film device, band-pass filter is widely used in pattern recognition, infrared detection, optical fiber communication, etc. In this paper, an algorithm for automatic measurement of band-pass filter quality criterion is proposed based on the proven theory calculation of derivate spectral transmittance of filter formula. Firstly, wavelet transform to reduce spectrum data noises is used. Secondly, combining with the Gaussian curve fitting and least squares method, the algorithm fits spectrum curve and searches the peak. Finally, some parameters for judging band-pass filter quality are figure out. Based on the algorithm, a pipeline for band-pass filters automatic measurement system has been designed that can scan the filter array automatically and display spectral transmittance of each filter. At the same time, the system compares the measuring result with the user defined standards to determine if the filter is qualified or not. The qualified product will be market with green color, and the unqualified product will be marked with red color. With the experiments verification, the automatic measurement system basically realized comprehensive, accurate and rapid measurement of band-pass filter quality and achieved the expected results.

  1. A system for monitoring cardiac vibration, respiration, and body movement in bed using an infrared.

    Science.gov (United States)

    Maki, Hiromichi; Ogawa, Hidekuni; Tsukamoto, Sosuke; Yonezawa, Yoshiharu; Caldwell, W Morton

    2010-01-01

    We have developed a non-invasive system for monitoring cardiac vibrations, respiration and body movement of in-bed hospitalized patients and elderly people who need constant care. These physiological parameters are recorded by an infrared emitting diode and a photo transistor, which are attached between spring coils in bed mattress. The infrared emitting diode diffuses infrared light into the mattress. The diffusion of this energy is changed by mattress shape variations and spring coil vibrations, which modulate the intensity of the received infrared signal. The intensity is also modulated by physiological parameters such as heart pulse, respiration and body movement. The physiological parameters are detected from the received infrared intensity signal by low, high and band pass filters.

  2. Bacteria/virus filter membrane

    Science.gov (United States)

    Lysaght, M. S.; Goodwin, F.; Roebelen, G.

    1977-01-01

    Hollow acrylate fiber membrane that filters bacterial and viral organisms can be used with closed-cycle life-support systems for underwater habitations or laboratories. Membrane also has applications in fields of medicine, gnotobiotics, pharmaceutical production, and industries and research facilities that require sterile water. Device eliminates need for strong chemicals or sterilizing agents, thereby reducing costs.

  3. Wideband Lithium Niobate FBAR Filters

    Directory of Open Access Journals (Sweden)

    Thomas Baron

    2013-01-01

    Full Text Available Filters based on film bulk acoustic resonators (FBARs are widely used for mobile phone applications, but they can also address wideband aerospace requirements. These devices need high electromechanical coupling coefficients to achieve large band pass filters. The piezoelectric material LiNbO3 complies with such specifications and is compatible with standard fabrication processes. In this work, simple metal—LiNbO3—metal structures have been developed to fabricate single FBAR elements directly connected to each other on a single chip. A fabrication process based on LiNbO3/silicon Au-Au bonding and LiNbO3 lapping/polishing has been developed and is proposed in this paper. Electrical measurements of these FBAR filters are proposed and commented exhibiting filters with 8% of fractional bandwidth and 3.3 dB of insertion losses. Electrical measurements show possibilities to obtain 14% of fractional bandwidth. These devices have been packaged, allowing for power handling, thermal, and ferroelectric tests, corresponding to spatial conditions.

  4. Sample-whitened matched filters

    DEFF Research Database (Denmark)

    Andersen, Ib

    1973-01-01

    components. These filters are shown to exist for ali realistic channels and the complete set of SWMF's for any channel is determined. It is shown that for nonpathological channels there is a unique SWMF which minimizes the amount of intersymbol interference defined as the discrete-time analog to the rms...

  5. Static Filtered Sky Color Constancy

    Directory of Open Access Journals (Sweden)

    Ali Alkhalifah

    2016-05-01

    Full Text Available In Computer Vision, the sky color is used for lighting correction, image color enhancement, horizon alignment, image indexing, and outdoor image classification and in many other applications. In this article, for robust color based sky segmentation and detection, usage of lighting correction for sky color detection is investigated. As such, the impact of color constancy on sky color detection algorithms is evaluated and investigated. The color correction (constancy algorithms used includes Gray-Edge (GE, Gray-World (GW, Max-RGB (MRGB and Shades-of-Gray (SG. The algorithms GE, GW, MRGB, and SG, are tested on the static filtered sky modeling. The static filter is developed in the LAB color space. This evaluation and analysis is essential for detection scenarios, especially, color based object detection in outdoor scenes. From the results, it is concluded that the color constancy before sky color detection using LAB static filters has the potential of improving sky color detection performance. However, the application of the color constancy can impart adverse effects on the detection results. For images, the color constancy algorithms depict a compact and stable representative of the sky chroma loci, however, the sky color locus might have a shifting and deviation in a particular color representation. Since the sky static filters are using the static chromatic values, different results can be obtained by applying color constancy algorithms on various datasets.

  6. Fast cartoon + texture image filters.

    Science.gov (United States)

    Buades, Antoni; Le, Triet M; Morel, Jean-Michel; Vese, Luminita A

    2010-08-01

    Can images be decomposed into the sum of a geometric part and a textural part? In a theoretical breakthrough, [Y. Meyer, Oscillating Patterns in Image Processing and Nonlinear Evolution Equations. Providence, RI: American Mathematical Society, 2001] proposed variational models that force the geometric part into the space of functions with bounded variation, and the textural part into a space of oscillatory distributions. Meyer's models are simple minimization problems extending the famous total variation model. However, their numerical solution has proved challenging. It is the object of a literature rich in variants and numerical attempts. This paper starts with the linear model, which reduces to a low-pass/high-pass filter pair. A simple conversion of the linear filter pair into a nonlinear filter pair involving the total variation is introduced. This new-proposed nonlinear filter pair retains both the essential features of Meyer's models and the simplicity and rapidity of the linear model. It depends upon only one transparent parameter: the texture scale, measured in pixel mesh. Comparative experiments show a better and faster separation of cartoon from texture. One application is illustrated: edge detection.

  7. Conflict-Induced Perceptual Filtering

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

    2012-01-01

    In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…

  8. Bacteria/virus filter membrane

    Science.gov (United States)

    Lysaght, M. S.; Goodwin, F.; Roebelen, G.

    1977-01-01

    Hollow acrylate fiber membrane that filters bacterial and viral organisms can be used with closed-cycle life-support systems for underwater habitations or laboratories. Membrane also has applications in fields of medicine, gnotobiotics, pharmaceutical production, and industries and research facilities that require sterile water. Device eliminates need for strong chemicals or sterilizing agents, thereby reducing costs.

  9. Service discovery using Bloom filters

    NARCIS (Netherlands)

    Goering, P.T.H.; Heijenk, Gerhard J.; Lelieveldt, B.P.F.; Haverkort, Boudewijn R.H.M.; de Laat, C.T.A.M.; Heijnsdijk, J.W.J.

    A protocol to perform service discovery in adhoc networks is introduced in this paper. Attenuated Bloom filters are used to distribute services to nodes in the neighborhood and thus enable local service discovery. The protocol has been implemented in a discrete event simulator to investigate the

  10. Quantized, piecewise linear filter network

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    1993-01-01

    A quantization based piecewise linear filter network is defined. A method for the training of this network based on local approximation in the input space is devised. The training is carried out by repeatedly alternating between vector quantization of the training set into quantization classes an...

  11. Thermography of semi-transparent materials by a FLIR ThermaCAM SC3000 infrared camera

    NARCIS (Netherlands)

    Van der Tempel, L.

    2011-01-01

    An acceptance test for thermography of semi-transparent materials by a FLIR ThermaCAM SC3000 infrared camera with 8.0 µm low-wavelength-pass filter has been developed and performed on polycarbonate, PEN, quartz, Corning 1737 glass, G427 cone glas, G443 screen glass, Schott Zerodur, silicon and a

  12. Thermography of semi-transparent materials by a FLIR ThermaCAM SC3000 infrared camera

    NARCIS (Netherlands)

    Van der Tempel, L.

    2011-01-01

    An acceptance test for thermography of semi-transparent materials by a FLIR ThermaCAM SC3000 infrared camera with 8.0 µm low-wavelength-pass filter has been developed and performed on polycarbonate, PEN, quartz, Corning 1737 glass, G427 cone glas, G443 screen glass, Schott Zerodur, silicon and a bl

  13. Restoration of abraded and covered marks engraved in steel using active infrared thermography

    DEFF Research Database (Denmark)

    Quattrocchi, A.; Piccolo, Sebastiano; Montanini, R.

    2016-01-01

    by means of different manufacturing processes (laser, dot peen, impact, press and scribe). Optical excitation of the target surface has been achieved using pulse, lock-in and step heating. Raw infrared images were analysed with a dedicated image processing software originally developed in Matlab (TM......), exploiting several methods, which include thermographic signal reconstruction, guided filtering and logarithmic transformation....

  14. Research on Gaussian distribution preprocess method of infrared multispectral image background clutter

    Institute of Scientific and Technical Information of China (English)

    张伟; 武春风; 邓盼; 范宁

    2004-01-01

    This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on the skewness-kurtosis test. In the end, a multivariate Gaussian distribution mathematical expression of background clutter image is given.

  15. A Near-Infrared Photometer for the Laboratorio Nacional de Astrofisica

    Science.gov (United States)

    Lepine, J. R. D.; Gneiding, C.; Laporte, R.; Dias, A. O.; Epchtein, N.

    1990-11-01

    ABSTRACT. A near-infrared photometer has been constructed with an InSb photovoltaic detector. At present, we dispose of two filters for bands H (1.6 m) and K (2.2 ijm). The acquisition of data is made using a IBMXT microcomputer. Keq o'td : INSTRUMENTS - PHOTOMETRY

  16. Design and Implementation of Wave Digital Filters

    Directory of Open Access Journals (Sweden)

    V. Davidek

    2001-09-01

    Full Text Available One of possibilities of the Wave Digital Filters (WDF design isusing the classical LC-filters theory. The aim of this paper is todemonstrate the design of WDF from the LC filter and the implementationof WDF on the fixed-point digital signal processor. The theory of wavedigital filter has been developed by using the classical scatteringparameter theory. The theory of ladder filters is well-known, and soour present problem can thus be reduced to a problem how to replace theL and C elements of the filters by adaptors and delay elements, addersand multipliers.

  17. Discrete continuous-phase superresolving filters.

    Science.gov (United States)

    Zhou, Sumei; Zhou, Changhe

    2004-12-01

    A new type of phase-only superresolving pupil filter with a discrete continuous-phase profile is presented that is a combination of discrete multilevel-phase modulation and continuous-phase modulation. This type of filter can achieve better superresolution performance than the continuous-phase filters reported in Opt. Lett. 28, 607 (2003). Therefore, with regard to the superresolution effect, this type of filter deserves study for practical applications. More importantly, the diffraction performance of this type of filter can explain the effect of a discrete-phase filter illuminated with a continuous wave front, whose superresolving performance cannot be analyzed with previous superresolution methods.

  18. Automated Integrated Analog Filter Design Issues

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2015-07-01

    Full Text Available An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is tested by designing an integrated active RC filter in a 65 nm CMOS technology.

  19. Performance comparison of various time variant filters

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, M. [JEOL Engineering Co. Ltd., Akishima, Tokyo (Japan); Husimi, K.

    1996-07-01

    This paper describes the advantage of the trapezoidal filter used in semiconductor detector system comparing with the other time variant filters. The trapezoidal filter is the compose of a rectangular pre-filter and a gated integrator. We indicate that the best performance is obtained by the differential-integral summing type rectangular pre-filter. This filter is not only superior in performance, but also has the useful feature that the rising edge of the output waveform is linear. We introduce an example of this feature used in a high-energy experiment. (author)

  20. Indirect Kalman Filter in Mobile Robot Application

    Directory of Open Access Journals (Sweden)

    Surachai Panich

    2010-01-01

    Full Text Available Problem statement: The most successful applications of Kalman filtering are to linearize about some nominal trajectory in state space that does not depend on the measurement data. The resulting filter is usually referred to as simply a linearized Kalman filter. Approach: This study introduced mainly indirect Kalman filter to estimate robot’s position. A developed differential encoder system integrated accelerometer is experimental tested in square shape. Results: Experimental results confirmed that indirect Kalman filter improves the accuracy and confidence of position estimation. Conclusion: In summary, we concluded that indirect Kalman filter has good potential to reduce error of measurement data.