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  1. Multichannel Seismic Reflection Data - SCAR - Amundsen Sea - 1986-1987, SDLS CD-ROM vol 23

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1986-87 in the Amundsen Sea, Antarctica, by the Japan National Oil Corporation....

  2. Multichannel Seismic Reflection Data - SCAR - Ross Sea 1987-1988, SDLS CD-ROM vol 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from six lines recorded during 1988 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

  3. Multichannel Seismic Reflection Data - SCAR - Ross Sea 1980, SDLS, CD-ROM vol 5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from eleven lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

  4. Multichannel Seismic Reflection Data - SCAR - Ross Sea 1982, SDLS CD-ROM vol 12

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from seven lines recorded during 1982 in the Ross Sea, Antarctica, by the Institut Francais du...

  5. Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1987, SDLS CD-ROM vol 13

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during the 1987 field season in the Ross Sea, Antarctica, by SEVMORGEOLOGIA, RUSSIA. The...

  6. Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1980, SDLS, CD-ROM vol 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from seven lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

  7. Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1980, SDLS CD-ROM vol 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from four lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

  8. Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

  9. Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 19

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

  10. Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 18

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

  11. Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1989, SDLS CD-ROM vol 14

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1989 field season in the Ross Sea, Antarctica, by the SEVMORGEOLOGIA, RUSSIS. The...

  12. Multichannel Seismic Reflection Data - SCAR, Ross Sea - 1982-1983, CD-ROM vol 9

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from fourteen lines recorded during 1982 in the Ross Sea and Wilkes Island, Antarctica, by the...

  13. Investigaton of ÇINARCIK Basin and North Anatolian Fault Within the Sea of Marmara with Multichannel Seismic Reflection Data

    Science.gov (United States)

    Atgın, O.; Çifçi, G.; Sorlien, C.; Seeber, L.; Steckler, M.; Sillington, D.; Kurt, H.; Dondurur, D.; Okay, S.; Gürçay, S.; Sarıtaş, H.; Küçük, H. M.

    2012-04-01

    The Sea of Marmara is becoming a natural laboratory for structure, sedimentation, and fluid flow within the North Anatolian fault (NAF) system. Much marine geological and geophysical data has been collected there since the deadly 1999 M=7.2. Izmit earthquake. The Sea of Marmara occupies 3 major basins, with the study area located in the eastern Cinarcik basin near Istanbul. These basins are the results of an extensional component in releasing segments between bends in this right-lateral tranmsform. It is controversial whether the extensional component is taken up by partitioned normal slip on separate faults, or instead by oblique right-normal slip on the non-vertical main northern branch of the NAF. High resolution multichannel seismic reflection (MCS) and multibeam bathymetry data collected by R/V K.Piri Reis and R/V Le-Suroit as part of two different projects respectively entitled "SeisMarmara", "TAMAM" and "ESONET". 3000 km of multichannel seismic reflection profiles were collected in 2008 and 2010 using 72, 111, and 240 channels of streamer with a 6.25 m group interval. The generator-injector airgun was fired every 12.5 or 18.75 m and the resulting MCS data has 10-230 Hz frequency band. The aim of the study is to investigate continuation of North Anatolian Fault along the Sea of Marmara, in order to investigate migration of depo-centers past a fault bend. We also test and extend a recently-published age model, quantify extension across short normal faults, and investigate whether a major surface fault exists along the southern edge of Çınarcık Basin. MCS profiles indicate that main NAF strand is located at the northern boundary of Çınarcık Basin and has a large vertical component of slip. The geometry of the eastern (Tuzla) bend and estimated right-lateral slip rates from GPS data requires as much of ten mm/yr of extension across Çınarcık Basin. Based on the published age model, we calculate about 2 mm/yr of extension on short normal faults in the

  14. Characterization of the sub-mesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of multichannel seismic data

    Science.gov (United States)

    Sallares, Valenti; Moncada, Jhon F.; Biescas, Berta; Klaeschen, Dirk

    2016-04-01

    Large-scale ocean dynamics is linked to small-scale mixing by means of turbulence, which enables the exchange of kinetic energy across the scales. At equilibrium, the energy flux that is injected at the production range must be balanced by mixing at the dissipation range. While the physics of the different ranges is now well established, an observational gap exists at the 103-101 m scale that prevents to characterize the transition from the anisotropic internal wave motions to isotropic turbulence. This lack of empirical evidence limits our understanding of the mechanisms governing the downward energy cascade, hampering the predictive capability of ocean circulation models. Here we show that this observational gap can be covered using high-resolution multichannel seismic (HR-MCS) data. Spectral analysis of acoustic reflectors imaged in the Alboran Sea (Western Mediterranean) thermocline evidences that this transition is caused by shear instabilities. In particular, we show that the averaged horizontal wavenumber (kx) spectra of the reflector's vertical displacements display three subranges that reproduce theoretical spectral slopes of internal waves [λx>100 m, with λx=kx-1], Kelvin-Helmholtz (KH)-type shear instabilities[100 m> λx>33 m], and turbulence[λx<33 m]. The presence of the transitional subrange in the averaged spectrum indicates that the whole chain of events is occurring continuously and simultaneously in the surveyed area. The availability of a system providing observational data at the appropriate scales opens new perspectives to incorporate small-scale mixing in predictive ocean modelling research.

  15. Rifting in the Northern Tyrrhenian Sea: Results from a combined wide-angle and multichannel seismic study

    Science.gov (United States)

    Moeller, S.; Grevemeyer, I.; Ranero, C. R.; Berndt, C.; Klaeschen, D.; Sallares, V.; Zitellini, N.; de Franco, R.

    2012-12-01

    Extension in the continental lithosphere leads to the formation of rift basins or finally to passive continental margins where plates fully broke apart. The extensional processes at basins and passive margins are still not fully understood. One of the reasons is that the observed amount of crustal thinning is often much higher than the horizontal extension in the brittle upper crust that can be accounted by faulting. Regarding this objective we present an analysis of two W-E striking depth-migrated multichannel- and wide-angle seismic sections from the Northern Tyrrhenian Sea. The new data were acquired onboard the Spanish R/V Sarmiento de Gamboa and Italian R/V Uraniain spring 2010, within the framework of the MEDOC project. The lines cross the basin from the Corsica and Sardinia margins towards the conjugated Latium/Campania margins (Italy). Along the transects we found two distinct domains distinguishable in tectonic style, heat-flow and crustal thickness: 1) The deep sedimentary Corsica and Sardinia basins in the West which formation started in the Oligocene (~30 Ma) and reveal a fan-shaped sedimentary infill with the Messinian erosional unconformity on top (~5-7 Ma) and 2) rifted crystalline continental crust expressed by horst and graben structures towards the East. These two domains are separated by a deep reaching (~10 km) and westward dipping fault/thrust complex. To quantify the amount of horizontal extension we identified pre-, syn-, and post-tectonic sedimentary units in the northern line A-B (Figure 1), calculated the relative extension factor by large faults as well as balancing the length of the pre-tectonic basement. The Messinian reflector can be well identified throughout the complete section and is therefore an excellent time-marker within the syn-tectonic sequence. The syn-tectonic sequence is limited by a reflector of Pliocene age. The above lying Pleistocene to Quaternary sediments are undisturbed and identified as the post-tectonic sequence

  16. Rifting in the Northern Tyrrhenian Sea: Results from a combined wide-angle and multichannel seismic study

    Science.gov (United States)

    Möller, Stefan; Grevemeyer, Ingo; Ranero, Cesar R.; Berndt, Christian; Klaeschen, Dirk; Sallares, Valenti; Zitellini, Nevio; de Franco, Roberto

    2013-04-01

    Extension in the continental lithosphere leads to the formation of rift basins or finally to passive continental margins where plates fully broke apart. The extensional processes at basins and passive margins are still not fully understood. One of the reasons is that the observed amount of crustal thinning is often much higher than the horizontal extension in the brittle upper crust that can be accounted by faulting. Moreover, conjugated margins are often observed to be asymmetric in tectonic style. Regarding these objective we present an analysis of two W-E striking multichannel- and wide-angle seismic sections from the Northern Tyrrhenian Sea. The new data were acquired onboard the Spanish R/V Sarmiento de Gamboa and Italian R/V Urania in spring 2010, within the framework of the MEDOC project. The lines cross the basin from the Corsica and Sardinia Margins towards the conjugated Latium and Campania Margins (Italy). The transects are divided in four zones distinguishable in tectonic style, velocity distribution, heat-flow and crustal thickness: 1) The deep sedimentary Corsica and Sardinia basins in the West which formed during Oligocene (~30 Ma) and reveal a fan-shaped sedimentary infill that is sealed by a Messinian erosional unconformity on top (~5-7 Ma). 2) Large rotated blocks bounding the deepest sub-basins along the entire transects and contain Messinian syn-tectonic sediments. 3) A zone of highly fractured continental crust broadens to the south and is indicated by a high number of faults and coincident with a velocity reduction. Furthermore, magmatic activity during Pliocene age in the southern line is evident in the southern line. 4) Flat summits at the Latium Margin indicate that this zone was above seal-level during rifting whereas the southern region was sub-sealevel. Faults cutting the seafloor indicate recent tectonic activity. To quantify the amount of horizontal extension we identified pre-, syn-, and post-tectonic sedimentary units in the northern

  17. A Cenozoic tectono-sedimentary model of the Tainan Basin, the South China Sea: evidence from a multi-channel seismic profile

    Institute of Scientific and Technical Information of China (English)

    Wei-wei DING; Jia-biao LI; Ming-bi LI; Xue-lin QIU; Yin-xia FANG; Yong TANG

    2008-01-01

    The Tainan Basin is one of the set of Cenozoic extensional basins along northern margin of the South China Sea that experienced extension and subsequently thermal subsidence. The Tainan Basin is close to the Taiwan Arc-Trench System and straddles a transition zone between oceanic and continental crust. A new regional multi-channel seismic profile (973-01) across the region of NE South China Sea is introduced in this paper. In seismic stratigraphy and structural geology, a model of Cenozoic tectono-sedimentation of the Tainan Basin is established. The results show that three stages can be suggested in Tainan Basin; In Stage A (Oligocene (?)-Lower Miocene) the stratigraphy shows restricted rifting, indicating crustal extension. Terrestrial sediments mostly filled the faulted sags of the North Depression on the continental shelf~ Structural highs, including the Central Uplift, blocked material transportation to the South Depression in abyssal basin. In Stage B the Tainan Basin (Middle-Upper Miocene) exhibits a broad subsidence resulting from the post-tiffing thermal cooling. The faulted-sags in North Depression had been filled up. Terrestrial materials were transported over the structural highs and deposited directly in the South Depression through submarine gullies or canyons. This sedimentation resulted in a crucial change in the slope to a modern shape. In Stage C (Latesl Miocene-Recent) a phase change from extension to compression took place due to the orogeny caused by the overthrusting of the Luzon volcanic arc. Many inverse structures, such as thrusts, fault bend folds, and a regional unconformity were formed. Forland basin began developing.

  18. First Results from the Multi-beam Bathymetry and Multi-channel Seismic Reflection Data offshore Cide-Sinop, Southern Black Sea shelf

    Science.gov (United States)

    Alp, Y. I.; Ocakoglu, N.; Kılıc, F.; Ozel, A. O.

    2016-12-01

    The morphological and seismic features offshore Cide-Sinop at the Southern Black Sea shelf area were first time investigated by multi-beam bathymetric and multi-channel seismic reflection data under the Research Project of The Scientific and Technological Research Council of Turkey (TUBİTAK-ÇAYDAG-114Y057). Multi-beam bathymetric data were collected between 2002-2008 from onboard the research vessels TCG Çubuklu and TCG Çeşme run by the Turkish Navy, Department of Navigation, Hydrography and Oceanography (TN-DNHO) with the system an Elac-Nautic 1050D. Multi-channel seismic reflection data were collected by Turkish Petroleum Corporation (TPAO) Company in 1991. Multi-beam measurements cover 2.59 km2 areas and depths change from -1 to -500 m. Elevation data were digitized from contour lines of 1/25K topo-maps of General Command of Mapping, with the contour interval of 10 m and supplementary 5 m contours in areas of low relief. Contour and shore lines, multi-beam points were interpolated into DEMs of pixel size 10 m and 5 m respectively, using Annudem algorithm. The Geographic Information System (GIS) software was used to analyse and visualize the two data sets. Seismic reflection data were processed by conventional methods under `Echos' seismic data processing software and time migrated seismic sections were produced. DEMs were combined with seismic reflection sections to understand the morphological and morphodynamic character of the study area. First results indicate that offshore Cide-Sinop is characterised by a quite smooth and large shelf plain with an approx. 25 km wide and the water depth of about -100 m. The bathymetry gently deepens from inner shelf toward shelf break at -120 m isobath. Slope angles from 0 to 1 degrees at the shelf plain, increases about to 10 degrees beyond the shelf edge. The large shelf plain is widely characterized by sand dunes with an average height of 10 meters form E-W oriented belts of 500-1000 m in width. Toward offshore

  19. China's first intermediate resolution multi-channel seismic survey in the northern Victoria Land Basin and Terror Rift, Ross Sea, Antarctica

    Science.gov (United States)

    Shen, Zhongyan; Gao, Jinyao; Zhang, Tao; Wang, Wei; Ding, Weifeng; Zhang, Sheng

    2017-04-01

    The West Antarctic Rift System (WARS) represents one of the largest active continental rift systems on Earth and is less well known than other rift systems because it is largely covered by thick ice. The Terror Rift (TR), superimposing on the Victoria Land Basin (VLB) in the western Ross Sea, is identified as the most recent deformational zone of the WARS, thus will provide knowledge of the active deformation process of the WARS. The structure and kinematics of the TR is under debate. Originally, the TR was thought to consist of two parts: the Discovery Graben and the magmatically-intruded Lee Arch. New denser seismic grid in the middle and southern segments of the TR revealed a different structure of the Lee Arch while the northern segment of the TR is not well studied. The glacial history of the VLB/TR region is another attractive issue to the geologists since this area records the behavior information of EAIS and WAIS. In the southern part of the VLB, especially in the McMurdo Sound, the framework of the glacial history is well established after several deep cores which recovery the whole stratigraphic sequences since the onset of the glaciation. However, the glacial history of the northern part of the VLB/TR is less well studied and here we emphasize its importance because the northern part of the VLB/TR is a link between the well-studied southern VLB and the sediment-well-preserved Northern Basin. During the 32nd Chinese National Antarctic Research Expedition, on the board of the RV XueLong, we collected intermediate resolution multi-channel seismic reflection data in the northern VLB/TR. These data will establish new constraints on the timing of deformation, structure and kinematics of the TR, and the history of the EAIS and WAIS.

  20. Early-stage rifting of the northern Tyrrhenian Sea Basin: Results from a combined wide-angle and multichannel seismic study

    Science.gov (United States)

    Moeller, S.; Grevemeyer, I.; Ranero, C. R.; Berndt, C.; Klaeschen, D.; Sallares, V.; Zitellini, N.; Franco, R.

    2013-08-01

    Extension of the continental lithosphere leads to the formation of rift basins and ultimately may create passive continental margins. The mechanisms that operate during the early stage of crustal extension are still intensely debated. We present the results from coincident multichannel seismic and wide-angle seismic profiles that transect across the northern Tyrrhenian Sea Basin. The profiles cross the Corsica Basin (France) to the Latium Margin (Italy) where the early-rift stage of the basin is well preserved. We found two domains, each with a distinct tectonic style, heat flow and crustal thickness. One domain is the Corsica Basin in the west that formed before the main rift phase of the northern Tyrrhenian Sea opening (˜8-4 Ma). The second domain is rifted continental crust characterized by tilted blocks and half-graben structures in the central region and at the Latium Margin. These two domains are separated by a deep (˜10 km) sedimentary complex of the eastern portion of the Corsica Basin. Travel-time tomography of wide-angle seismic data reveals the crustal architecture and a subhorizontal 15-17 ± 1 km deep Moho discontinuity under the basin. To estimate the amount of horizontal extension we have identified the pre-, syn-, and post-tectonic sedimentary units and calculated the relative displacement of faults. We found that major faults initiated at angles of 45°-50° and that the rifted domain is horizontally stretched by a factor of β ˜ 1.3 (˜8-10 mm/a). The crust has been thinned from ˜24 to ˜17 km indicating a similar amount of extension (˜30%). The transect represents one of the best imaged early rifts and implies that the formation of crustal-scale detachments, or long-lived low-angle normal faults, is not a general feature that controls the rift initiation of continental crust. Other young rift basins, like the Gulf of Corinth, the Suez Rift or Lake Baikal, display features resembling the northern Tyrrhenian Basin, suggesting that half

  1. Multichannel EEG Visualization

    NARCIS (Netherlands)

    Caat, Michael ten

    2008-01-01

    Electroencephalography (EEG) measures electrical brain activity by electrodes attached to the scalp. Multichannel EEG refers to a measurement with a large number of electrodes. EEG has clinical as well as scientific applications, including neurology, psychology, pharmacy, linguistics, and biology.

  2. Multi-Channel Retailing

    Directory of Open Access Journals (Sweden)

    Dirk Morschett, Dr.,

    2005-01-01

    Full Text Available Multi-channel retailing entails the parallel use by retailing enterprises of several sales channels. The results of an online buyer survey which has been conducted to investigate the impact of multi-channel retailing (i.e. the use of several retail channels by one retail company on consumer behaviour show that the frequently expressed concern that the application of multi-channel systems in retailing would be associated with cannibalization effects, has proven unfounded. Indeed, the appropriate degree of similarity, consistency, integration and agreement achieves the exact opposite. Different channels create different advantages for consumers. Therefore the total benefit an enterprise which has a multi-channel system can offer to its consumers is larger, the greater the number of available channels. The use of multi-channel systems is associated with additional purchases in the different channels. Such systems are thus superior to those offering only one sales channel to their customers. Furthermore, multi-channel systems with integrated channels are superior to those in which the channels are essentially autonomous and independent of one another. In integrated systems, consumers can achieve synergy effects in the use of sales-channel systems. Accordingly, when appropriately formulated, multi-channel systems in retailing impact positively on consumers. They use the channels more frequently, buy more from them and there is a positive customer-loyalty impact. Multi-channel systems are strategic options for achieving customer loyalty, exploiting customer potential and for winning new customers. They are thus well suited for approaching differing and varied target groups.

  3. Multichannel Human Body Communication

    Science.gov (United States)

    Przystup, Piotr; Bujnowski, Adam; Wtorek, Jerzy

    2016-01-01

    Human Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog signal has been tested. Experiment results show that HBC is a feasible solution for transmitting data between BSN nodes.

  4. Chemiluminescence multichannel immunosensor

    Energy Technology Data Exchange (ETDEWEB)

    Yacoub-George, E.; Scheithauer, W.; Koppi, A.; Meixner, L.; Drost, S. [Fraunhofer Inst. fuer Mikroelektronische Schaltungen und Systeme (IMS), Muenchen (Germany); Wolf, H. [Regensburg Univ. (Germany). Inst. of Medical Microbiology and Hygiene

    2001-07-01

    An automated chemiluminescence multichannel immunosensor for the parallel detection of three different substances is presented. The system is based on the chemiluminescence capillary ELISA technique in combination with a miniaturised fluidics system. Fused silica capillaries (FSC) are used as support for the immobilized antibodies. The sensing component consists of three stripe photodiodes. An integrated flow-through system ensures automation of the assay cycles. Data on the detection of the bacterial toxin staphylococcal enterotoxin B (SEB), the bacteriophage M13 and Escherichia coli O157:H7 are presented. (orig.)

  5. Evaluation of multichannel reproduced sound

    DEFF Research Database (Denmark)

    Choisel, Sylvain; Wickelmaier, Florian Maria

    2007-01-01

    A study was conducted with the goal of quantifying auditory attributes which underlie listener preference for multichannel reproduced sound. Short musical excerpts were presented in mono, stereo and several multichannel formats to a panel of forty selected listeners. Scaling of auditory attributes...

  6. Microfluidic Multichannel Flow Cytometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a "Microfluidic Multichannel Flow Cytometer." Several novel concepts are integrated to produce the final design, which is compatible with...

  7. Multichannel Coding of Applause Signals

    Directory of Open Access Journals (Sweden)

    Jeroen Breebaart

    2007-08-01

    Full Text Available We develop a parametric multichannel audio codec dedicated to coding signals consisting of a dense series of transient-type events. These signals of which applause is a typical example are known to be problematic for such audio codecs. The codec design is based on preservation of both timbre and transient-type event density. It combines a very low complexity and a low parameter bit rate (0.2 kbps. In a formal listening test, we compared the proposed codec to the recently standardised MPEG Surround multichannel codec, with an associated parameter bit rate of 9 kbps. We found the new codec to have a significantly higher audio quality than the MPEG Surround codec for the two multichannel applause signals under test. Though this seems promising, the technique presented is not fully mature, for example, because issues related to integration of the proposed codec in the MPEG Surround codec were not addressed.

  8. Multichannel Error Correction Code Decoder

    Science.gov (United States)

    1996-01-01

    NASA Lewis Research Center's Digital Systems Technology Branch has an ongoing program in modulation, coding, onboard processing, and switching. Recently, NASA completed a project to incorporate a time-shared decoder into the very-small-aperture terminal (VSAT) onboard-processing mesh architecture. The primary goal was to demonstrate a time-shared decoder for a regenerative satellite that uses asynchronous, frequency-division multiple access (FDMA) uplink channels, thereby identifying hardware and power requirements and fault-tolerant issues that would have to be addressed in a operational system. A secondary goal was to integrate and test, in a system environment, two NASA-sponsored, proof-of-concept hardware deliverables: the Harris Corp. high-speed Bose Chaudhuri-Hocquenghem (BCH) codec and the TRW multichannel demultiplexer/demodulator (MCDD). A beneficial byproduct of this project was the development of flexible, multichannel-uplink signal-generation equipment.

  9. Multichannel analysis of surface waves

    Science.gov (United States)

    Park, C.B.; Miller, R.D.; Xia, J.

    1999-01-01

    The frequency-dependent properties of Rayleigh-type surface waves can be utilized for imaging and characterizing the shallow subsurface. Most surface-wave analysis relies on the accurate calculation of phase velocities for the horizontally traveling fundamental-mode Rayleigh wave acquired by stepping out a pair of receivers at intervals based on calculated ground roll wavelengths. Interference by coherent source-generated noise inhibits the reliability of shear-wave velocities determined through inversion of the whole wave field. Among these nonplanar, nonfundamental-mode Rayleigh waves (noise) are body waves, scattered and nonsource-generated surface waves, and higher-mode surface waves. The degree to which each of these types of noise contaminates the dispersion curve and, ultimately, the inverted shear-wave velocity profile is dependent on frequency as well as distance from the source. Multichannel recording permits effective identification and isolation of noise according to distinctive trace-to-trace coherency in arrival time and amplitude. An added advantage is the speed and redundancy of the measurement process. Decomposition of a multichannel record into a time variable-frequency format, similar to an uncorrelated Vibroseis record, permits analysis and display of each frequency component in a unique and continuous format. Coherent noise contamination can then be examined and its effects appraised in both frequency and offset space. Separation of frequency components permits real-time maximization of the S/N ratio during acquisition and subsequent processing steps. Linear separation of each ground roll frequency component allows calculation of phase velocities by simply measuring the linear slope of each frequency component. Breaks in coherent surface-wave arrivals, observable on the decomposed record, can be compensated for during acquisition and processing. Multichannel recording permits single-measurement surveying of a broad depth range, high levels of

  10. Multichannel VCO needs only one reference

    Science.gov (United States)

    Masson, R. K.; Morenc, N. P.

    1979-01-01

    Frequency stabilizing circuit controls output of multichannel microwave oscillator using passband filters and selector logic to eliminate need for separate crystal diode voltage controlled oscillator (VCO).

  11. Material identification with multichannel radiographs

    Science.gov (United States)

    Collins, Noelle; Jimenez, Edward S.; Thompson, Kyle R.

    2017-02-01

    This work aims to validate previous exploratory work done to characterize materials by matching their attenuation profiles using a multichannel radiograph given an initial energy spectrum. The experiment was performed in order to evaluate the effects of noise on the resulting attenuation profiles, which was ignored in simulation. Spectrum measurements have also been collected from various materials of interest. Additionally, a MATLAB optimization algorithm has been applied to these candidate spectrum measurements in order to extract an estimate of the attenuation profile. Being able to characterize materials through this nondestructive method has an extensive range of applications for a wide variety of fields, including quality assessment, industry, and national security.

  12. Multichanneled puzzle-like encryption

    Science.gov (United States)

    Amaya, Dafne; Tebaldi, Myrian; Torroba, Roberto; Bolognini, Néstor

    2008-07-01

    In order to increase data security transmission we propose a multichanneled puzzle-like encryption method. The basic principle relies on the input information decomposition, in the same way as the pieces of a puzzle. Each decomposed part of the input object is encrypted separately in a 4 f double random phase mask architecture, by setting the optical parameters in a determined status. Each parameter set defines a channel. In order to retrieve the whole information it is necessary to properly decrypt and compose all channels. Computer simulations that confirm our proposal are presented.

  13. Perfect Multi-Channel Flat Reflectors

    CERN Document Server

    Asadchy, V S; Elsakka, A; Albooyeh, M; Tretyakov, S A

    2016-01-01

    Recent advances in engineered gradient metasurfaces have enabled unprecedented opportunities for light manipulation using optically thin sheets, such as anomalous refraction, reflection, or focusing of an incident beam. Here we introduce a concept of multi-channel functional metasurfaces, which are able to control incoming and outgoing waves in a number of propagation directions or polarization states simultaneously and independently. In particular, we reveal a possibility to create perfect multi-channel reflectors. Under the assumption of reciprocity and energy conservation, we find that there exist three fundamental classes of multi-channel mirrors. Together they form a basis of all possible reflection functionalities achievable with flat periodically modulated reflectors. To demonstrate the potential of the introduced concept, we design and experimentally test one of the basis multi-channel reflectors, confirming the desired multi-channel response. Furthermore, by extending the concept to reflectors suppor...

  14. A Multichannel Bioluminescence Determination Platform for Bioassays.

    Science.gov (United States)

    Kim, Sung-Bae; Naganawa, Ryuichi

    2016-01-01

    The present protocol introduces a multichannel bioluminescence determination platform allowing a high sample throughput determination of weak bioluminescence with reduced standard deviations. The platform is designed to carry a multichannel conveyer, an optical filter, and a mirror cap. The platform enables us to near-simultaneously determine ligands in multiple samples without the replacement of the sample tubes. Furthermore, the optical filters beneath the multichannel conveyer are designed to easily discriminate colors during assays. This optical system provides excellent time- and labor-efficiency to users during bioassays.

  15. Challenges and opportunities in multichannel customer management

    NARCIS (Netherlands)

    Neslin, Scott A.; Grewal, Dhruv; Leghorn, Robert; Shankar, Venkatesh; Teerling, Marije L.; Thomas, Jacquelyn S.; Verhoef, Peter C.

    2006-01-01

    Multichannel customer management is the design, deployment, coordination, and evaluation of channels through which firms and customers interact, with the goal of enhancing customer value through effective customer acquisition, retention, and development. The authors identify five major challenges pr

  16. Challenges and opportunities in multichannel customer management

    NARCIS (Netherlands)

    Neslin, Scott A.; Grewal, Dhruv; Leghorn, Robert; Shankar, Venkatesh; Teerling, Marije L.; Thomas, Jacquelyn S.; Verhoef, Peter C.

    2006-01-01

    Multichannel customer management is the design, deployment, coordination, and evaluation of channels through which firms and customers interact, with the goal of enhancing customer value through effective customer acquisition, retention, and development. The authors identify five major challenges

  17. Challenges and opportunities in multichannel customer management

    NARCIS (Netherlands)

    Neslin, Scott A.; Grewal, Dhruv; Leghorn, Robert; Shankar, Venkatesh; Teerling, Marije L.; Thomas, Jacquelyn S.; Verhoef, Peter C.

    2006-01-01

    Multichannel customer management is the design, deployment, coordination, and evaluation of channels through which firms and customers interact, with the goal of enhancing customer value through effective customer acquisition, retention, and development. The authors identify five major challenges pr

  18. Multi-channel software defined radio experimental evaluation and analysis

    CSIR Research Space (South Africa)

    Van der Merwe, JR

    2014-09-01

    Full Text Available Multi-channel software-defined radios (SDRs) can be utilised as inexpensive prototyping platforms for transceiver arrays. The application for multi-channel prototyping is discussed and measured results of coherent channels for both receiver...

  19. Multichannel photocells for image converters with color separation

    Energy Technology Data Exchange (ETDEWEB)

    Denisova, E. A.; Uzdovskii, V. V., E-mail: uzdovskii@list.ru; Khainovskii, V. I. [Moscow Institute of Electronic Technology (Russian Federation)

    2011-12-15

    The results of a study of photoelectric processes in photosensitive structures based on a multichannel vertically integrated p-n junction are presented. Optical radiation absorption in the space-charge region of a multichannel vertically integrated structure is studied.

  20. Multichannel framework for singular quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Camblong, Horacio E., E-mail: camblong@usfca.edu [Department of Physics and Astronomy, University of San Francisco, San Francisco, CA 94117-1080 (United States); Epele, Luis N., E-mail: epele@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); Fanchiotti, Huner, E-mail: huner@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); García Canal, Carlos A., E-mail: garcia@fisica.unlp.edu.ar [Laboratorio de Física Teórica, Departamento de Física, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67–1900 La Plata (Argentina); Ordóñez, Carlos R., E-mail: ordonez@uh.edu [Department of Physics, University of Houston, Houston, TX 77204-5506 (United States)

    2014-01-15

    A multichannel S-matrix framework for singular quantum mechanics (SQM) subsumes the renormalization and self-adjoint extension methods and resolves its boundary-condition ambiguities. In addition to the standard channel accessible to a distant (“asymptotic”) observer, one supplementary channel opens up at each coordinate singularity, where local outgoing and ingoing singularity waves coexist. The channels are linked by a fully unitary S-matrix, which governs all possible scenarios, including cases with an apparent nonunitary behavior as viewed from asymptotic distances. -- Highlights: •A multichannel framework is proposed for singular quantum mechanics and analogues. •The framework unifies several established approaches for singular potentials. •Singular points are treated as new scattering channels. •Nonunitary asymptotic behavior is subsumed in a unitary multichannel S-matrix. •Conformal quantum mechanics and the inverse quartic potential are highlighted.

  1. Restoration of multichannel microwave radiometric images

    Science.gov (United States)

    Chin, R. T.; Yeh, C.-L.; Olson, W. S.

    1985-01-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Its properties and limitations are presented. The effect of noise was investigated and a better understanding of the performance of the algorithm with noisy data has been achieved. The restoration scheme with the selection of appropriate constraints was applied to a practical problem. The 6.6, 10.7, 18, and 21 GHz satellite images obtained by the scanning multichannel microwave radiometer (SMMR), each having different spatial resolution, were restored to a common, high resolution (that of the 37 GHz channels) to demonstrate the effectiveness of the method. Both simulated data and real data were used in this study. The restored multichannel images may be utilized to retrieve rainfall distributions.

  2. Designing a Multichannel Map Service Concept

    Directory of Open Access Journals (Sweden)

    Hanna-Marika Halkosaari

    2013-01-01

    Full Text Available This paper introduces a user-centered design process for developing a multichannel map service. The aim of the service is to provide hikers with interactive maps through several channels. In a multichannel map service, the same spatial information is available through various channels, such as printed maps, Web maps, mobile maps, and other interactive media. When properly networked, the channels share a uniform identity so that the user experiences the different channels as a part of a single map service. The traditional methods of user-centered design, such as design probes, personas, and scenarios, proved useful even in the emerging field of developing multichannel map services. The findings emphasize the need to involve users and multidisciplinary teams in the conceptual phases of designing complex services aimed at serving various kinds of users.

  3. Restoration of multichannel microwave radiometric images

    Science.gov (United States)

    Chin, R. T.; Yeh, C.-L.; Olson, W. S.

    1985-01-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Its properties and limitations are presented. The effect of noise was investigated and a better understanding of the performance of the algorithm with noisy data has been achieved. The restoration scheme with the selection of appropriate constraints was applied to a practical problem. The 6.6, 10.7, 18, and 21 GHz satellite images obtained by the scanning multichannel microwave radiometer (SMMR), each having different spatial resolution, were restored to a common, high resolution (that of the 37 GHz channels) to demonstrate the effectiveness of the method. Both simulated data and real data were used in this study. The restored multichannel images may be utilized to retrieve rainfall distributions.

  4. Multichannel long-range Rydberg molecules

    CERN Document Server

    Eiles, Matthew T

    2015-01-01

    A generalized class of ultra-long-range Rydberg molecules is proposed which consist of a multichannel Rydberg atom whose outermost electron creates a chemical bond with a distant ground state atom. Such multichannel Rydberg molecules exhibit favorable properties for laser excitation, because states exist where the quantum defect varies strongly with the principal quantum number. The resulting occurrence of near degeneracies with states of high orbital angular momentum promotes the admixture of low $l$ into the high $l$ deeply bound `trilobite' molecule states, thereby circumventing the usual difficulty posed by electric dipole selection rules. Such states also can exhibit multi-scale binding possibilities that could present novel options for quantum manipulation.

  5. Modelling customer behaviour in multi-channel service distribution

    NARCIS (Netherlands)

    Heinhuis, D.; de Vries, E.J.; Kundisch, D.; Veit, D.J.; Weitzel, T.; Weinhardt, C.

    2009-01-01

    Financial service providers are innovating their distribution strategy into multi-channel strategies. The success of a multi-channel approach and the high investments made in information systems and enterprise architectures depends on the adoption and multi-channel usage behaviour of consumers. We b

  6. Modelling customer behaviour in multi-channel service distribution

    NARCIS (Netherlands)

    Heinhuis, D.; de Vries, E.J.; Kundisch, D.; Veit, D.J.; Weitzel, T.; Weinhardt, C.

    2009-01-01

    Financial service providers are innovating their distribution strategy into multi-channel strategies. The success of a multi-channel approach and the high investments made in information systems and enterprise architectures depends on the adoption and multi-channel usage behaviour of consumers. We

  7. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite produced by NAVO (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  8. GHRSST Level 2P Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-18 satellite produced by NAVO (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  9. GHRSST Level 2P Atlantic Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset for the Atlantic Ocean and nearby regions based on multi-channel sea surface...

  10. GHRSST Level 2P Atlantic Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-16 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset for the Atlantic Ocean and nearby regions based on multi-channel sea surface...

  11. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset based on multi-channel sea surface temperature (SST) retrievals from the...

  12. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-16 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset based on multi-channel sea surface temperature (SST) retrievals from the...

  13. GHRSST Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite produced by NAVO (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  14. Multichannel Shopper Segments and Their Covariates

    NARCIS (Netherlands)

    Konus, Umut; Verhoef, Peter C.; Neslin, Scott A.

    2008-01-01

    The proliferation of channels has created new challenges for research, including understanding how consumers may be segmented with respect to their information search and purchase behavior in multichannel environment. This research considers shopping a dynamic process that consists of search and pur

  15. How to Succeed with Multichannel Management

    DEFF Research Database (Denmark)

    Madsen, Christian; Kræmmergaard, Pernille

    2016-01-01

    . This interplay between traditional and e-government channels remains to be explained. There is also a lack of empirical knowledge of how government organizations can apply findings from user studies and migrate citizens online while simultaneously reducing traffic through traditional channels. Therefore...... in calls. The authors offer contributions to the channel choice literature and recommendations on multichannel management to practitioners....

  16. Multichannel Shopper Segments and Their Covariates

    NARCIS (Netherlands)

    Konus, Umut; Verhoef, Peter C.; Neslin, Scott A.

    2008-01-01

    The proliferation of channels has created new challenges for research, including understanding how consumers may be segmented with respect to their information search and purchase behavior in multichannel environment. This research considers shopping a dynamic process that consists of search and

  17. Kruisbestuiving voorwaarde voor succesvolle multichannel strategie

    NARCIS (Netherlands)

    Van Ameijden, D.; Huismans, J.; Wenting, R.; Krawczyk, A.; Weltevreden, J.W.J.

    2011-01-01

    Retailers met een succesvolle multichannel strategie creëren kruisbestuiving tussen de diverse verkoopkanalen. Via welk kanaal consumenten hun aankoop uiteindelijk doen, wordt voor hen steeds minder belangrijk; het draait allemaal om klantbehoud. Dit blijkt uit een verkennend onderzoek van PwC en de

  18. Multichannel compressive sensing MRI using noiselet encoding.

    Directory of Open Access Journals (Sweden)

    Kamlesh Pawar

    Full Text Available The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS. In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  19. Multichannel compressive sensing MRI using noiselet encoding.

    Science.gov (United States)

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  20. MCA: a multichannel approach to SAR autofocus.

    Science.gov (United States)

    Morrison, Robert L; Do, Minh N; Munson, David C

    2009-04-01

    We present a new noniterative approach to synthetic aperture radar (SAR) autofocus, termed the multichannel autofocus (MCA) algorithm. The key in the approach is to exploit the multichannel redundancy of the defocusing operation to create a linear subspace, where the unknown perfectly focused image resides, expressed in terms of a known basis formed from the given defocused image. A unique solution for the perfectly focused image is then directly determined through a linear algebraic formulation by invoking an additional image support condition. The MCA approach is found to be computationally efficient and robust and does not require prior assumptions about the SAR scene used in existing methods. In addition, the vector-space formulation of MCA allows sharpness metric optimization to be easily incorporated within the restoration framework as a regularization term. We present experimental results characterizing the performance of MCA in comparison with conventional autofocus methods and discuss the practical implementation of the technique.

  1. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    CERN Document Server

    Pawar, Kamlesh; Zhang, Jingxin

    2014-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI, and presents a method to design the pulse sequence for the noiselet encoding. This novel encoding scheme is combined with the multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. An empirical RIP a...

  2. Coupling output of multichannel high power microwaves

    Science.gov (United States)

    Li, Guolin; Shu, Ting; Yuan, Chengwei; Zhang, Jun; Yang, Jianhua; Jin, Zhenxing; Yin, Yi; Wu, Dapeng; Zhu, Jun; Ren, Heming; Yang, Jie

    2010-12-01

    The coupling output of multichannel high power microwaves is a promising technique for the development of high power microwave technologies, as it can enhance the output capacities of presently studied devices. According to the investigations on the spatial filtering method and waveguide filtering method, the hybrid filtering method is proposed for the coupling output of multichannel high power microwaves. As an example, a specific structure is designed for the coupling output of S/X/X band three-channel high power microwaves and investigated with the hybrid filtering method. In the experiments, a pulse of 4 GW X band beat waves and a pulse of 1.8 GW S band microwave are obtained.

  3. Integrated Multichannel Customer Service Plan For Stark

    OpenAIRE

    Oinasmaa, Roosa

    2016-01-01

    The main objective of this thesis was to introduce three compatible integrated customer service templates for Stark according to the needs and wants of the customer service department. These providers all offer integrated technological solutions for multichannel services. This was done in order to improve work efficiency and thus have a positive effect on the customer experience. The purpose of the thesis was to find out what tools and programs the customer service representatives and the hea...

  4. Spatiotemporal Analysis of Multichannel EEG: CARTOOL

    OpenAIRE

    Denis Brunet; Murray, Micah M; Michel, Christoph M.

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous resul...

  5. GHRSST Level 2P Global 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-18 satellite produced by NAVO (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  6. GHRSST Level 2P Regional 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-19 satellite produced by NAVO (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  7. GHRSST Level 2P Global skin Sea Surface Temperature from the Infrared Atmospheric Sounding Interferometer (IASI) on the Metop-B satellite (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in real-time...

  8. GHRSST Level 2P Global 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-19 satellite produced by NAVO (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  9. GHRSST Level 2P Global 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A satellite produced by NAVO (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  10. GHRSST Level 2P Global skin Sea Surface Temperature from the Infrared Atmospheric Sounding Interferometer (IASI) on the Metop-A satellite (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global 1 km Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated...

  11. GHRSST Level 2P Global 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-B satellite produced by NAVO (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  12. GHRSST Level 2P Global Skin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A satellite produced by EUMETSAT (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global 1 km Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated...

  13. GHRSST Level 2P sub-skin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on Metop satellites (currently Metop-A) (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global 1 km Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated...

  14. GHRSST Level 2P sub-skin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on Metop satellites (currently Metop-B) (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global 1 km Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated...

  15. Auralization of an orchestra using multichannel and multisource technique (A)

    DEFF Research Database (Denmark)

    Vigeant, Michelle C.; Wang, Lily M.; Rindel, Jens Holger

    2006-01-01

    Previous work has shown the importance of including source directivity in computer modeling for auralizations. A newer method to capture source directivity in auralizations is the multichannel technique, which uses multichannel anechoic recordings. In this study, five-channel anechoic recordings...... approximately one-fifth of a sphere with the corresponding anechoic recording channel and mixing these together. The multichannel auralizations from each instrument were subsequently combined to produce a full multichannel auralization of the entire orchestra. The results from listening tests will be presented...... made with a single channel orchestral anechoic recording using (ii) a surface source and (iii) a single omni-directional source. [Work supported by the National Science Foundation.]...

  16. Selling to the Multi-channel Consumer: Strategic And Operational Challenges for Multi-channel Retailers

    NARCIS (Netherlands)

    Ameijden, van D.; Vulpen, van J.; Huismans, J.; Wenting, R.; Krawczyk, A.; Weltevreden, J.W.J.

    2012-01-01

    Het ontwikkelen van een goede multichannel strategie is één van de belangrijkste uitdagingen waar retailers vandaag de dag voor staan. Een toenemend aantal ‘traditionele’ retailers ziet het opzetten van een webshop als een belangrijke aanvulling op hun fysieke winkels en probeert te profiteren van d

  17. Multichannel image regularization using anisotropic geodesic filtering

    Energy Technology Data Exchange (ETDEWEB)

    Grazzini, Jacopo A [Los Alamos National Laboratory

    2010-01-01

    This paper extends a recent image-dependent regularization approach introduced in aiming at edge-preserving smoothing. For that purpose, geodesic distances equipped with a Riemannian metric need to be estimated in local neighbourhoods. By deriving an appropriate metric from the gradient structure tensor, the associated geodesic paths are constrained to follow salient features in images. Following, we design a generalized anisotropic geodesic filter; incorporating not only a measure of the edge strength, like in the original method, but also further directional information about the image structures. The proposed filter is particularly efficient at smoothing heterogeneous areas while preserving relevant structures in multichannel images.

  18. Multi-Channel Maximum Likelihood Pitch Estimation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2012-01-01

    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  19. Natural Gradient Approach to Multichannel Blind Deconvolution

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper we study the geometrical structures of FIR filters and their application to multichannel blind deconvolution.First we introduce a Lie group structure and a Riemannian structure on the manifolds of the FIR filters.Then we derive the natural gradients on the manifolds using the isometry of the Riemannian metric.Using the natural gradient,we present a novel learning algorithm for blind deconvolution based on the minimization of mutual information.Some properties of the learning algorithm,such as equivariance and stability are also studied.Finally,the simulations are given to illustrate the effectiveness and validity of the proposed algorithm.

  20. Multichannel analysis of forward scattered body waves

    Science.gov (United States)

    Neal, Scott Lawrence

    We describe a series of innovations which are the basis for a multichannel approach to direct imaging of forward scattered body waves recorded on broadband seismic arrays. The foundation is a method through which the irregularly sampled observed seismograms are interpolated onto an arbitrarily fine grid by means of a convolution between a spatial window function and the actual station locations. The result is a weighted stack which employs all the data to compute a robust and stable multichannel estimate of the wavefield. Deconvolution of the stacked data is shown to be equivalent to a multichannel deconvolution, with spatially variable weights equal to those used in stacking. Application to data from the Lodore array in Colorado and Wyoming shows variations in crustal structure across the array and also images upper mantle discontinuities. A second innovation focuses on the design of deconvolution operators that account for the loss of high frequency components of P-to- S conversions. Two variants are presented, the first increases linearly with P-to-S lag time, the second is based on convolutional quelling and a t* attenuation model. Both methods account for the high attentuation of S waves in the upper mantle. The quelling approach however, has two advantages; it is physically based, and it provides a unified framework for the combination of stacking and deconvolution. We apply multichannel stacking to derive three quantities from the observed data and the associated receiver functions: (1) correlation between stacks of the entire array and local subarray stacks, (2) RMS amplitude of the receiver functions, and (3) Pms-to- P amplitude variations. Application of these attributes to data from recent broadband array deployments in southern Africa, Colorado and Wyoming, and the Tien Shan of central Asia shows these attributes to be highly correlated with the geology of the study areas and to be indicative of major lithospheric discontinuities beneath an array

  1. Multi-channel coherent perfect absorbers

    KAUST Repository

    Bai, Ping

    2016-05-18

    The absorption efficiency of a coherent perfect absorber usually depends on the phase coherence of the incident waves on the surfaces. Here, we present a scheme to create a multi-channel coherent perfect absorber in which the constraint of phase coherence is loosened. The scheme has a multi-layer structure such that incident waves in different channels with different angular momenta can be simultaneously and perfectly absorbed. This absorber is robust in achieving high absorption efficiency even if the incident waves become "incoherent" and possess "random" wave fronts. Our work demonstrates a unique approach to designing highly efficient metamaterial absorbers. © CopyrightEPLA, 2016.

  2. High-resolution processing methods for multi-channel reflection seismic data of Lile sea area in the southern South China Sea%南海南部礼乐海区二维地震资料的高分辨率处理方法

    Institute of Scientific and Technical Information of China (English)

    郑红波; 阎贫; 王彦林

    2014-01-01

    Lile sea area of the southern South China Sea has become an important prospective area of oil and gas exploration because of its abundant resources. At present, the exploration level of Lile sea area is low, and there are only two-dimensional seismic data of a few survey lines. Due to complex terrains and large changes of water depth, multiform interferential waves can be commonly distinguished from these seismic data. Moreover, the trace number of shot gather is small, and the S/N ration of data is low. Above factors are of disadvantage to high-resolution processing of seismic data. According to the characteristics of seismic data in the area, various means have been used for true amplitude recovery and abnormal amplitude suppression in the pretreatment. Series deconvolution methods have been used to enhance the resolution of the seismic data;τ-p domain predictive deconvolution, velocity filtering and inner muting have been adopted for multiples suppression based on the types of multiples. From the result of processing, it can be found that the energy of shallow, middle and deep layers is proportioned. Interferential waves such as multiples have been well suppressed, and the S/N ratio and resolution of seismic data have been improved. High-resolution seismic stacked profiles have been achieved finally.%南海南部礼乐海区以其丰富的油气资源储备成为我国油气勘探的后备区,目前勘探程度低,地震资料较少,仅有少量的二维地震资料。由于该区地形复杂、水深变化范围大,因此在地震数据中发育着多种类型的干扰波,加之该批数据道数少、信噪比低,上述因素都成为高分辨率处理的难点。针对该区地震数据的特征,采用多种手段的真振幅恢复技术以及异常振幅压制等预处理方法;采用串联反褶积提高了资料的分辨率;根据多次波的类型分别采用τ-p域预测反褶积、速度滤波、内切除等组合方法压制多次

  3. Order fulfillment and logistics considerations for multichannel retailers

    NARCIS (Netherlands)

    Roodbergen, Kees Jan; Kolman, Inger B.; Zijm, W.H.M.; Klumpp, M.; Clausen, V.; Ten Hompel, M.

    2016-01-01

    This paper addresses the challenge of making multichannel decisions for order fulfillment and logistics. We present a framework for multichannel strategies consisting of seven elements. Some channel decisions are part of the marketing mix, with the ultimate choice left to the customer. Other channel

  4. Multichannel discharge between jet electrolyte cathode and jet electrolyte anode

    NARCIS (Netherlands)

    Shakirova, E. F.; Gaitsin, Al. F.; Son, E. E.

    2011-01-01

    We present the results of an experimental study of multichannel discharge between a jet electrolyte cathode and jet electrolyte anode within a wide range of parameters. We pioneer the reveal of the burning particularities and characteristics of multichannel discharge with jet electrolyte and droplet

  5. Multichannel Discharge Between Jet Electrolyte Cathode and Solid Anode

    NARCIS (Netherlands)

    Mustafin, T. B.; Gaitsin, Al. F.

    We investigate particularities of burning of multichannel discharge between a jet electrolyte anode and solid cathode within a wide range of parameters. We observe the multichannel discharge propagation over the humid plexiglas cathode surface and discover its various shapes. We reveal the

  6. Order fulfillment and logistics considerations for multichannel retailers

    NARCIS (Netherlands)

    Roodbergen, Kees Jan; Kolman, Inger B.; Zijm, W.H.M.; Klumpp, M.; Clausen, V.; Ten Hompel, M.

    2016-01-01

    This paper addresses the challenge of making multichannel decisions for order fulfillment and logistics. We present a framework for multichannel strategies consisting of seven elements. Some channel decisions are part of the marketing mix, with the ultimate choice left to the customer. Other channel

  7. Spatiotemporal Analysis of Multichannel EEG: CARTOOL

    Directory of Open Access Journals (Sweden)

    Denis Brunet

    2011-01-01

    Full Text Available This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way.

  8. Spatiotemporal analysis of multichannel EEG: CARTOOL.

    Science.gov (United States)

    Brunet, Denis; Murray, Micah M; Michel, Christoph M

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way.

  9. Multichannel deconvolution: the generalized sampling approach

    Science.gov (United States)

    Vrhel, Michael J.; Unser, Michael A.

    1994-09-01

    We investigate the problem of signal restoration and reconstruction in a multi-channel system with the constraint that the entire system acts as a projection operator. This projection requirement is optimal in the noise free case since an input signal which is contained in the reconstruction space is recovered exactly. We find a general optimization problem which gives rise to a large class of projection operators. This formalization allows optimization of various criteria while enforcing the projection constraint. In this paper, we consider the projection operator which minimizes the noise power at the system output. The significance of this work is that it incorporates knowledge of the final reconstruction method which can include splines, wavelets, or display devices. In addition, unlike most classical formulations, the input signal is not required to be band- limited; it can be an arbitrary finite energy function. The approach requires no a priori information about the input signal, but does require knowledge of the impulse responses of the input channels. The projection method is compared to a generalized multi-channel Wiener filter which uses a priori signal information. At best the projection approach achieves the least squares solution which is the orthogonal projection of the input signal onto the space defined by the reconstruction method.

  10. Photoplethysmograph quality estimation through multichannel filtering.

    Science.gov (United States)

    Silva, Ikaro; Lee, Joon; Mark, Roger

    2011-01-01

    Information about the quality of a recorded physiological waveform can be valuable for the detection of critical medical conditions. This work presents a new point-by-point signal quality index (SQI) based on adaptive multichannel prediction which does not rely on ad-hoc morphological feature extraction from the target waveform. An application of the SQI to photoplethysmograph waveforms showed that the SQI is monotonically related to SNR (simulated by adding white noise) and subjective human quality assessment of 1,313 waveform epochs. A receiver-operating-characteristic (ROC) curve analysis, with the human "bad" quality label as negative and the human "good" quality label as positive, yielded an area under the ROC curve of 0.863. For photoplethysmograph waveforms, a SQI greater than 0.8 seems in general to be indicative of good signal quality.

  11. SQUID-based multichannel system for Magnetoencephalography

    CERN Document Server

    Rombetto, S; Vettoliere, A; Trebeschi, A; Rossi, R; Russo, M

    2013-01-01

    Here we present a multichannel system based on superconducting quantum interference devices (SQUIDs) for magnetoencephalography (MEG) measurements, developed and installed at Istituto di Cibernetica (ICIB) in Naples. This MEG system, consists of 163 full integrated SQUID magnetometers, 154 channels and 9 references, and has been designed to meet specifications concerning noise, dynamic range, slew rate and linearity through optimized design. The control electronics is located at room temperature and all the operations are performed inside a Magnetically Shielded Room (MSR). The system exhibits a magnetic white noise level of approximatively 5 fT/Hz1=2. This MEG system will be employed for both clinical and routine use. PACS numbers: 74.81.Fa, 85.25.Hv, 07.20.Mc, 85.25.Dq, 87.19.le, 87.85.Ng

  12. Multichannel quantum defect theory for polar molecules

    Science.gov (United States)

    Elfimov, Sergei V.; Dorofeev, Dmitrii L.; Zon, Boris A.

    2014-02-01

    Our work is devoted to developing a general approach for nonpenetrating Rydberg states of polar molecules. We propose a method to estimate the accuracy of calculation of their wave functions and quantum defects. Basing on this method we estimate the accuracy of Born-Oppenheimer (BO) and inverse Born-Oppenheimer (IBO) approximations for these states. This estimation enables us to determine the space and energy regions where BO and IBO approximations are valid. It depends on the interplay between l coupling (due to dipole potential of the core) and l uncoupling (due to rotation the core). Next we consider the intermediate region where both BO and IBO are not valid. For this intermediate region we propose a modification of Fano's multichannel quantum defect theory to match BO and IBO wave functions and show that it gives more reliable results. They are demonstrated on the example of SO molecule.

  13. Normalized Design of Multi-channel LIF Digital Receiver

    Institute of Scientific and Technical Information of China (English)

    方航锋; 郁发兴; 汪海航

    2004-01-01

    A design method for parallel processing application on multi-channel low-intermediate-frequency(LIF) digital receiver was presented. It is based on the DSP sub-array with a simple topology and operation timing to evaluate and determine the processing capability and then construct the parallel processing array for multi-channel signals according to the restriction of operation timing. Using this method, the design of multi-channel digital receiver may be simplified. Finally, a design example was used to show how to apply this method.

  14. Two-phase flow instability in a parallel multichannel system

    Institute of Scientific and Technical Information of China (English)

    HOU Suxia

    2009-01-01

    The two-phase flow instabilities observed in through parallel multichannel can be classified into three types, of which only one is intrinsic to parallel multichannel systems. The intrinsic instabilities observed in parallel multichannel system have been studied experimentally. The stable boundary of the flow in such a parallel-channel system are sought, and the nature of inlet flow oscillation in the unstable region has been examined experimentally under various conditions of inlet velocity, heat flux, liquid temperature, cross section of channel and entrance throttling. The results show that parallel multichannel system possess a characteristic oscillation that is quite independent of the magnitude and duration of the initial disturbance, and the stable boundary is influenced by the characteristic frequency of the system as well as by the exit quality when this is low, and upon raising the exit quality and reducing the characteristic frequency, the system increases its instability, and entrance throttling effectively contributes to stabilization of the system.

  15. Multi-Channel Optical Digitizer for Earth Sciences Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective was to design and manufacture a multi-channel high resolution analog-digital converter for digitizing a CCD image signal. The tasks included...

  16. A multichannel time-domain brain oximeter for clinical studies

    Science.gov (United States)

    Contini, Davide; Spinelli, Lorenzo; Caffini, Matteo; Cubeddu, Rinaldo; Torricelli, Alessandro

    2009-07-01

    We developed and optimized a multichannel dual-wavelength time-domain brain oximeter for functional studies in the clinical environment. The system, mounted on a 19"-rack, is interfaced with instrumentation for monitoring physiological parameters and for stimuli presentation.

  17. Practical Time Mark Estimators for Multichannel Digital Silicon Photomultipliers

    NARCIS (Netherlands)

    Venialgo, E.; Mandai, S.; Gong, T.; Schaart, D.R.; Charbon, E.

    2015-01-01

    Multiple time-to-digital converters coupled with silicon photomultipliers allow to timestamp several light photons generated by a scintillation event. Multichannel digital silicon photomultipliers opened the possibility to estimate a gammaphoton time mark by using several photoelectrons timestamps.

  18. Enhancement of coupled multichannel images using sparsity constraints.

    Science.gov (United States)

    Ramakrishnan, Naveen; Ertin, Emre; Moses, Randolph L

    2010-08-01

    We consider the problem of joint enhancement of multichannel images with pixel based constraints on the multichannel data. Previous work by Cetin and Karl introduced nonquadratic regularization methods for SAR image enhancement using sparsity enforcing penalty terms. We formulate an optimization problem that jointly enhances complex-valued multichannel images while preserving the cross-channel information, which we include as constraints tying the multichannel images together. We pose this problem as a joint optimization problem with constraints. We first reformulate it as an equivalent (unconstrained) dual problem and develop a numerically-efficient method for solving it. We develop the Dual Descent method, which has low complexity, for solving the joint optimization problem. The algorithm is applied to both an interferometric synthetic aperture radar (IFSAR) problem, in which the relative phase between two complex-valued images indicate height, and to a synthetic multimodal medical image example.

  19. Multichannel strategy - the dominant approach in modern retailing

    Directory of Open Access Journals (Sweden)

    Stojković Dragan

    2016-01-01

    Full Text Available The purpose of this paper is to thoroughly analyse the concept of multichannel strategy, focussing on retail, to enable the academic community and marketers to better understand its advantages and disadvantages. This paper presents a comprehensive literature review and financial data analysis. The authors have analysed the financial data of 88 retail companies in the 2007 to 2014 period, and have proven that the importance of multichannel strategy has grown with the emergence of e-commerce. The main hypothesis is that the multichannel concept dominates modern marketing channels because it is widely accepted and provides superior financial performance. Multichannel retailing is definitely a winning concept, if adequately implemented. However, wrongly implemented it can negatively influence business performance.

  20. Monolithic DWDM Multi-channel planar waveguide laser

    DEFF Research Database (Denmark)

    Sckerl, Mads W.; Guldberg-Kjær, Søren Andreas; Laurent-Lund, Christian

    1999-01-01

    silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained.......silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained....

  1. General Model for Infrastructure Multi-channel Wireless LANs

    OpenAIRE

    Fayez Gebali; Abdelsalam Amer

    2010-01-01

    In this paper we develop an integrated model for request mechanism and data transmission in multi-channel wireless local area networks. We calculated the performance parameters for single and multi-channel wireless networks when the channel is noisy. The proposed model is general it can be applied to different wireless networks such as IEEE802.11x, IEEE802.16, CDMA operated networks and Hiperlan\\2.

  2. Packed multi-channels for parallel chromatographic separations in microchips.

    Science.gov (United States)

    Nagy, Andrea; Gaspar, Attila

    2013-08-23

    Here we report on a simple method to fabricate microfluidic chip incorporating multi-channel systems packed by conventional chromatographic particles without the use of frits. The retaining effectivities of different bottlenecks created in the channels were studied. For the parallel multi-channel chromatographic separations several channel patterns were designed. The obtained multipackings were applied for parallel separations of dyes. The implementation of several chromatographic separation units in microscopic size makes possible faster and high throughput separations.

  3. Multi-Channel Retail Supply Chain Management: Fulfillment systems in Multi-Channel Retailing - Customer Expectations and Economic Performance

    OpenAIRE

    Lang, Gerald

    2010-01-01

    International audience; Increasingly, store-based retailers are opening an additional online sales channel and becoming multi-channel retailers. The integration of these different channels raises the question how to redefine the strategic marketing elements and the operations, as the two channels have different constraints and require different competences. This multi-channel retailing has major impacts on the operations and the supply-chain management. Order fulfillment for the customers usi...

  4. Time estimation with multichannel digital silicon photomultipliers.

    Science.gov (United States)

    Venialgo, Esteban; Mandai, Shingo; Gong, Tim; Schaart, Dennis R; Charbon, Edoardo

    2015-03-21

    Accuracy in timemark estimation is crucial for time-of-flight positron emission tomography, in order to ensure high quality images after reconstruction. Since the introduction of multichannel digital silicon photomultipliers, it is possible to acquire several photoelectron timestamps for each individual gamma event. We study several timemark estimators based on multiple photoelectron timestamps by means of a comprehensive statistical model. In addition, we calculate the MSE of the estimators in comparison to the Cramér-Rao lower bound as a function of the system design parameters. We investigate the effect of skipping some of the photoelectron timestamps, which is a direct consequence of the limited number of time-to-digital converters and we propose a technique to compensate for this effect. In addition, we carry out an extensive analysis to evaluate the influence of dark counts on the detector timing performance. Moreover, we investigate the improvement of the timing performance that can be obtained with dark count filtering and we propose an appropriate filtering method based on measuring the time difference between sorted timestamps. Finally, we perform a full Monte Carlo simulation to compare different timemark estimators by exploring several system design parameters. It is demonstrated that a simple weighted-average estimator can achieve a comparable performance as the more complex maximum likelihood estimator.

  5. Multichannel transfer function with dimensionality reduction

    KAUST Repository

    Kim, Han Suk

    2010-01-17

    The design of transfer functions for volume rendering is a difficult task. This is particularly true for multi-channel data sets, where multiple data values exist for each voxel. In this paper, we propose a new method for transfer function design. Our new method provides a framework to combine multiple approaches and pushes the boundary of gradient-based transfer functions to multiple channels, while still keeping the dimensionality of transfer functions to a manageable level, i.e., a maximum of three dimensions, which can be displayed visually in a straightforward way. Our approach utilizes channel intensity, gradient, curvature and texture properties of each voxel. The high-dimensional data of the domain is reduced by applying recently developed nonlinear dimensionality reduction algorithms. In this paper, we used Isomap as well as a traditional algorithm, Principle Component Analysis (PCA). Our results show that these dimensionality reduction algorithms significantly improve the transfer function design process without compromising visualization accuracy. In this publication we report on the impact of the dimensionality reduction algorithms on transfer function design for confocal microscopy data.

  6. Canonical framework for multi-channel SAR-GMTI

    Institute of Scientific and Technical Information of China (English)

    Liu Congfeng; Liao Guisheng

    2008-01-01

    Synthetic aperture radar (SAR) systems have become an important tool for fine-resolution mapping and other remote sensing operations.The multi-channel SAR ground moving-target indication (GMTI) must process its data to produce not only the image of surveillance area but also the information of the ground moving-targets.The topic of moving-target detection in clutter has been extensively studied,and there are many methods that are used to detect moving targets,such as displaced phase center antenna (DPCA) method,along-track interfero-metric (ATI) phase,space-time adaptive processing (STAP),or some other metrics.A canonical framework is proposed that encompasses all the multi-channel SAR-GMT methods,namely,DPCA and ATI.The statistical test metric for multi-channel SAR-GMTI is established in a simple form,via the definition of the complex central Wishart distribution,to deduce the statistics of the test metric,and the probability distribution of the test metric for multichannel SAR-GMTI has the complex central Wishart distribution of 1×1 case,namely the x2 distribution.The theory foundation offers the possibility to construct the united multi-channel SAR-GMTI detector,and derives the constant false alarm rate (CFAR) detector tests for separating moving targets from clutter.

  7. Multi-channel support for DMAC in WSNs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Currently most wireless sensor network applications assume the presence of single-channel medium access control (MAC) protocols. However, lower sensing range result in dense networks, single-channel MAC protocols may be inadequate due to higher demand for the limited bandwidth. In this paper we proposed a method of multi-channel support for DMAC in Wireless sensor networks (WSNs). The channel assignment method is based on local information of nodes. Our multi-channel DMAC protocol implement channel distribution before message collecting from source nodes to sink node and made broadcasting possible in DMAC. Analysis and simulation result displays this multi-channel protocol obviously decreases the latency without increasing energy consumption.

  8. Multichannel MAC Layer In Mobile Ad—Hoc Network

    Science.gov (United States)

    Logesh, K.; Rao, Samba Siva

    2010-11-01

    This paper we presented the design objectives and technical challenges in Multichannel MAC protocols in Mobile Ad-hoc Network. In IEEE 802.11 a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. Even though complex environments in ad hoc networks require a combined control of physical (PHY) and medium access control (MAC) layers resources in order to optimize performance. And also we discuss the characteristics of cross-layer frame and give a multichannel MAC approach.

  9. CAPACITY EVALUATION OF MULTI-CHANNEL WIRELESS AD HOC NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Li Jiandong; Zygmunt J. Haas; Min Sheng

    2003-01-01

    In this paper, the capacity of multi-channel, multi-hop ad hoc network is evaluated.In particular, the performance of multi-hop ad hoc network with single channel IEEE 802.11MAC utilizing different topologies is shown. Also the scaling laws of throughputs for large-scale ad hoc networks and the theoretical guaranteed throughput bounds for multi-channel gridtopology systems are proposed. The results presented in this work will help researchers to choosethe proper parameter settings in evaluation of protocols for multi-hop ad hoc networks.

  10. Handling Deafness Problem of Scheduled Multi-Channel Polling MACs

    Science.gov (United States)

    Jiang, Fulong; Liu, Hao; Shi, Longxing

    Combining scheduled channel polling with channel diversity is a promising way for a MAC protocol to achieve high energy efficiency and performance under both light and heavy traffic conditions. However, the deafness problem may cancel out the benefit of channel diversity. In this paper, we first investigate the deafness problem of scheduled multi-channel polling MACs with experiments. Then we propose and evaluate two schemes to handle the deafness problem. Our experiment shows that deafness is a significant reason for performance degradation in scheduled multi-channel polling MACs. A proper scheme should be chosen depending on the traffic pattern and the design objective.

  11. Adaptive identification of acoustic multichannel systems using sparse representations

    CERN Document Server

    Helwani, Karim

    2014-01-01

    This book treats the topic of extending the adaptive filtering theory in the context of massive multichannel systems by taking into account a priori knowledge of the underlying system or signal. The starting point is exploiting the sparseness in acoustic multichannel system in order to solve the non-uniqueness problem with an efficient algorithm for adaptive filtering that does not require any modification of the loudspeaker signals.The book discusses in detail the?derivation of general sparse representations of acoustic MIMO systems?in signal or system dependent transform domains.?Efficient a

  12. Relativistic Multichannel Treatment of Ionic Rydberg States of Lanthanum

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-Feng; JIA Feng-Dong; ZHONG Zhi-Ping; XUE Ping; XU Xiang-Yuan; YAN Jun

    2007-01-01

    Ionic Rydberg energy levels of lanthanum are calculated from first principles by relativistic multichannel theory within the framework of multichannel quantum defect theory. The present calculated results are in better agreement with the experimental measurements than the previous calculations [J. Phys. B 34 (2001)369] due to the consideration of dynamical polarizations. Moreover, in the experimental spectra achieved by a five-laser resonance excitation via the intermediate state 5d6d3 F2, a series of weak ionic Rydberg states and some of perturbing states are found and assigned in this work.

  13. Aspects of Remote Sensing in the GEOid and Sea level Of the North Atlantic Region (GEOSONAR) Project

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen; Nielsen, Allan Aasbjerg; Knudsen, Per

    1999-01-01

    The general objectives of the GEOid and Sea level Of the North Atlantic Region (GEOSONAR) project are presented. These include analyses of the dynamics of the ocean and its characteristics. The analyses are mainly based on remote sensing. As an example a data set obtained by the multi-channel Sea...

  14. Dense Clustered Multi-Channel Wireless Sensor Cloud

    Directory of Open Access Journals (Sweden)

    Sivaramakrishnan Sivakumar

    2015-08-01

    Full Text Available Dense Wireless Sensor Network Clouds have an inherent issue of latency and packet drops with regards to data collection. Though there is extensive literature that tries to address these issues through either scheduling, channel contention or a combination of the two, the problem still largely exists. In this paper, a Clustered Multi-Channel Scheduling Protocol (CMSP is designed that creates a Voronoi partition of a dense network. Each partition is assigned a channel, and a scheduling scheme is adopted to collect data within the Voronoi partitions. This scheme collects data from the partitions concurrently and then passes it to the base station. CMSP is compared using simulation with other multi-channel protocols like Tree-based Multi-Channel, Multi-Channel MAC and Multi-frequency Media Access Control for wireless sensor networks. Results indicate CMSP has higher throughput and data delivery ratio at a lower power consumption due to network partitioning and hierarchical scheduling that minimizes load on the network.

  15. Multichannel magnetic resonance sounding with wirelessly operated coils

    DEFF Research Database (Denmark)

    Bahner, Klaus Günter; Larsen, Jakob Juul; Auken, Esben

    2015-01-01

    The invention of multichannel MRS instruments, where additional channels are used for reference measurements of noise has been successful in improving the signal to noise ratio of MRS measurements, but the signal to noise ratio is still inadequate for reliable measurements in many places...

  16. The Art of Multi-channel Hypermedia Application Development

    NARCIS (Netherlands)

    Synodinos, Dionysios G.; Avgeriou, Paris

    2003-01-01

    The plethora of networked devices and platforms that continuously come to light, as well as the emergence of alternative ways to access the internet, have increased the demand for multi-channel access to hypermedia applications. Researchers and practitioners nowadays not only have to deal with the c

  17. Timing optimization utilizing order statistics and multichannel digital silicon photomultipliers

    NARCIS (Netherlands)

    Mandai, S.; Venialgo, E.; Charbon, E.

    2014-01-01

    We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have

  18. Multichannel quench-flow microreactor chip for parallel reaction monitoring

    NARCIS (Netherlands)

    Bula, Wojciech P.; Verboom, Willem; Reinhoudt, David N.; Gardeniers, Han J.G.E.

    2007-01-01

    This paper describes a multichannel silicon-glass microreactor which has been utilized to investigate the kinetics of a Knoevenagel condensation reaction under different reaction conditions. The reaction is performed on the chip in four parallel channels under identical conditions but with different

  19. Timing optimization utilizing order statistics and multichannel digital silicon photomultipliers

    NARCIS (Netherlands)

    Mandai, S.; Venialgo, E.; Charbon, E.

    2014-01-01

    We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have dem

  20. Online purchase intentions: A multi-channel store image perspective

    NARCIS (Netherlands)

    Verhagen, T.; van Dolen, W.

    2009-01-01

    The advantages of the bricks-and-clicks retail format in the battle for the online customer has been widely discussed but empirical research on it has been limited. We applied a multi-channel store image perspective to assess its influence on online purchase intentions. Drawing on a sample of 630 cu

  1. Progressive Syntax-Rich Coding of Multichannel Audio Sources

    Directory of Open Access Journals (Sweden)

    Dai Yang

    2003-09-01

    Full Text Available Being able to transmit the audio bitstream progressively is a highly desirable property for network transmission. MPEG-4 version 2 audio supports fine grain bit rate scalability in the generic audio coder (GAC. It has a bit-sliced arithmetic coding (BSAC tool, which provides scalability in the step of 1 Kbps per audio channel. There are also several other scalable audio coding methods, which have been proposed in recent years. However, these scalable audio tools are only available for mono and stereo audio material. Little work has been done on progressive coding of multichannel audio sources. MPEG advanced audio coding (AAC is one of the most distinguished multichannel digital audio compression systems. Based on AAC, we develop in this work a progressive syntax-rich multichannel audio codec (PSMAC. It not only supports fine grain bit rate scalability for the multichannel audio bitstream but also provides several other desirable functionalities. A formal subjective listening test shows that the proposed algorithm achieves an excellent performance at several different bit rates when compared with MPEG AAC.

  2. Timing optimization utilizing order statistics and multichannel digital silicon photomultipliers

    NARCIS (Netherlands)

    Mandai, S.; Venialgo, E.; Charbon, E.

    2014-01-01

    We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have dem

  3. Multi-channel service concept design and prototyping

    NARCIS (Netherlands)

    Sperling, C.P.; Simons, L.P.A.; Bouwman, W.A.G.A.

    2007-01-01

    Designing e-services which have to function in a multi-channel context has proved to be challenging for organizations. Previous research has shown that structured design methods are useful to structure the design process. In this paper we proceed from an existing method (which identifies

  4. Multi-channel service concept design and prototyping

    NARCIS (Netherlands)

    Sperling, C.P.; Simons, L.P.A.; Bouwman, W.A.G.A.

    2007-01-01

    Designing e-services which have to function in a multi-channel context has proved to be challenging for organizations. Previous research has shown that structured design methods are useful to structure the design process. In this paper we proceed from an existing method (which identifies multi-chann

  5. Multichannel measuring device of deformation for research materials of constructions

    Directory of Open Access Journals (Sweden)

    Druzhinin A.

    2008-06-01

    Full Text Available Possibility of Atmel ATMega microcontrollers use was shown for the interfacing of sensors devices with the modern computer systems. On the basis of Atmel ATMega16 microcontroller the multichannel system of treatment of information was developed for strain gauges, in which the amount of measuring channels is substantially increased.

  6. Rapidly converging multichannel controllers for broadband noise and vibrations

    NARCIS (Netherlands)

    Berkhoff, A.P.

    2010-01-01

    Applications are given of a preconditioned adaptive algorithm for broadband multichannel active noise control. Based on state-space descriptions of the relevant transfer functions, the algorithm uses the inverse of the minimum-phase part of the secondary path in order to improve the speed of converg

  7. Value Creation Challenges in Multichannel Retail Business Models

    Directory of Open Access Journals (Sweden)

    Mika Yrjölä

    2014-08-01

    Full Text Available Purpose: The purpose of the paper is to identify and analyze the challenges of value creation in multichannel retail business models. Design/methodology/approach: With the help of semi-structured interviews with top executives from different retailing environments, this study introduces a model of value creation challenges in the context of multichannel retailing. The challenges are analyzed in terms of three retail business model elements, i.e., format, activities, and governance. Findings: Adopting a multichannel retail business model requires critical rethinking of the basic building blocks of value creation. First of all, as customers effortlessly move between multiple channels, multichannel formats can lead to a mismatch between customer and firm value. Secondly, retailers face pressures to use their activities to form integrated total offerings to customers. Thirdly, multiple channels might lead to organizational silos with conflicting goals. A careful orchestration of value creation is needed to determine the roles and incentives of the channel parties involved. Research limitations/implications: In contrast to previous business model literature, this study did not adopt a network-centric view. By embracing the boundary-spanning nature of the business model, other challenges and elements might have been discovered (e.g., challenges in managing relationships with suppliers. Practical implications: As a practical contribution, this paper has analyzed the challenges retailers face in adopting multichannel business models. Customer tendencies for showrooming behavior highlight the need for generating efficient lock-in strategies. Customized, personal offers and information are ways to increase customer value, differentiate from competition, and achieve lock-in. Originality/value: As a theoretical contribution, this paper empirically investigates value creation challenges in a specific context, lowering the level of abstraction in the mostly

  8. Crustal structure in Gulf of Mexico from OBS refraction and multichannel reflection data

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, A.K.; Carye, J.; Latham, G.; Buffler, R.T.

    1981-07-01

    Results from 12 reversed refraction profiles each 110 km long have been combined with multichannel reflection data to produce a series of crustal structure sections across the Gulf of Mexico. The refraction data were collected using ocean bottom seismographs (OBS) and explosive charges ranging in size from 1 to 120 lb (0.45 to 54.42 kg). These data show as many as three layers of sedimentary rocks with total thickness between 5 and 9 km and layer velocities between 1.7 and 3.5 km/sec. Beneath most of the Gulf, this sedimentary section is underlain by a layer with velocity between 4.5 and 5.4 km/sec. The acoustic basement as defined by reflection data is confined within this layer. This basement layer, which may be the top of volcanic layer 2, is too thin to be detected in the refraction results. Beneath this layer in most of the deep Gulf is an oceanic crustal layer (layer 3), 3 to 6 km thick which thickens to about 12 km under the Mississippi fan and 10 km in the southeastern Gulf where it is interpreted to be transitional crust. Oceanic layer 3 has a velocity between 6.4 and 7.0 km/sec and overlies a mantle with velocity between 7.6 and 8.2 km/sec. The top of oceanic layer 3 was not observed on regional multichannel seismic profiles. These data confirm earlier refraction interpretation that most of the deep Gulf basin is underlain by an oceanic crustal layer flanked by transitional crust. This layer may have been formed by a mantle thermal event accompanied by a period of rapid sea-floor spreading. 16 figures, 1 table.

  9. A miniaturized ASIC-based multichannel scaler instrument

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, M.N.; Turner, G.W.; McMillan, D.E.; Hoffheins, B.S.; Todd, R.A. [Oak Ridge National Lab., TN (United States); Hiller, J.M. [Oak Ridge Y-12 Plant, TN (United States)

    1993-12-31

    A miniaturized multichannel scaler instrument has been developed to address size and operational constraints for data acquisition in a portable laser-induced luminescence system. The multichannel scaling (MCS) function is implemented as a programmable application specific integrated circuit (ASIC) with standard interfaces for control and data acquisition. The instrument is microcontroller-based with sufficient computing power for data manipulation and algorithmic processing. The unit includes electronics for laser control, and amplification and pulse height discrimination of PMT pulses. Modification of the instrument should allow use in nuclear, chemical, and spectroscopy related applications including Mossbauer experiments. Interfaces are incorporated allowing both computer-controlled and stand alone operation. Implementation of the MCS function as an ASIC and comparison with conventional implementations are discussed. Full characterization of the MCS is presented including differential non-linearity (DNL), bin dead time, and bandwidth measurements.

  10. Ratio-scaling of listener preference of multichannel reproduced sound

    DEFF Research Database (Denmark)

    Choisel, Sylvain; Wickelmaier, Florian

    2005-01-01

    , stereo and various multichannel formats) served as stimuli. On each trial, the task of the subjects was to choose the format they preferred, proceeding through all the possible pairs of the eight reproduction modes. This experiment was replicated with four types of programme material (pop and classical......-trivial assumption in the case of complex spatial sounds. In the present study the Bradley-Terry-Luce (BTL) model was employed to investigate the unidimensionality of preference judgments made by 40 listeners on multichannel reproduced sound. Short musical excerpts played back in eight reproduction modes (mono...... music). As a main result, the BTL model was found to predict the choice frequencies well. This implies that listeners were able to integrate the complex nature of the sounds into a unidimensional preference judgment. It further implies the existence of a preference scale on which the reproduction modes...

  11. Separable Representation of Multichannel Nucleon-Nucleus Optical Potentials

    CERN Document Server

    Hlophe, Linda

    2016-01-01

    One important ingredient for many applications of nuclear physics to astrophysics, nuclear energy, and stockpile stewardship are cross sections for reactions of neutrons with rare isotopes. Since direct measurements are often not feasible, indirect methods, e.g. (d,p) reactions, should be used. Those (d,p) reactions may be viewed as three-body reactions and described with Faddeev techniques. Faddeev equations in momentum space have a long tradition of utilizing separable interactions in order to arrive at sets of coupled integral equations in one variable. Optical potentials representing the effective interactions in the neutron (proton) nucleus subsystem are usually non-Hermitian as well as energy-dependent. Including excitations of the nucleus in the calculation requires a multichannel optical potential. The purpose of this paper is to introduce a separable, energy-dependent multichannel representation of complex, energy-dependent optical potentials that contain excitations of the nucleus and that fulfill r...

  12. Automated Detection of Red Lesions Using Superpixel Multichannel Multifeature

    Science.gov (United States)

    Wu, Chengdong

    2017-01-01

    Red lesions can be regarded as one of the earliest lesions in diabetic retinopathy (DR) and automatic detection of red lesions plays a critical role in diabetic retinopathy diagnosis. In this paper, a novel superpixel Multichannel Multifeature (MCMF) classification approach is proposed for red lesion detection. In this paper, firstly, a new candidate extraction method based on superpixel is proposed. Then, these candidates are characterized by multichannel features, as well as the contextual feature. Next, FDA classifier is introduced to classify the red lesions among the candidates. Finally, a postprocessing technique based on multiscale blood vessels detection is modified for removing nonlesions appearing as red. Experiments on publicly available DiaretDB1 database are conducted to verify the effectiveness of our proposed method. PMID:28512511

  13. Multi-channel atomic magnetometer for magnetoencephalography: a configuration study.

    Science.gov (United States)

    Kim, Kiwoong; Begus, Samo; Xia, Hui; Lee, Seung-Kyun; Jazbinsek, Vojko; Trontelj, Zvonko; Romalis, Michael V

    2014-04-01

    Atomic magnetometers are emerging as an alternative to SQUID magnetometers for detection of biological magnetic fields. They have been used to measure both the magnetocardiography (MCG) and magnetoencephalography (MEG) signals. One of the virtues of the atomic magnetometers is their ability to operate as a multi-channel detector while using many common elements. Here we study two configurations of such a multi-channel atomic magnetometer optimized for MEG detection. We describe measurements of auditory evoked fields (AEF) from a human brain as well as localization of dipolar phantoms and auditory evoked fields. A clear N100m peak in AEF was observed with a signal-to-noise ratio of higher than 10 after averaging of 250 stimuli. Currently the intrinsic magnetic noise level is 4fTHz(-1/2) at 10Hz. We compare the performance of the two systems in regards to current source localization and discuss future development of atomic MEG systems.

  14. Multi-Channel Noise Reduced Visual Evoked Potential Analysis

    Science.gov (United States)

    Palaniappan, Ramaswamy; Raveendran, Paramesran; Nishida, Shogo

    In this paper, Principal Component Analysis (PCA) is used to reduce noise from multi-channel Visual Evoked Potential (VEP) signals. PCA is applied to reduce noise from multi-channel VEP signals because VEP signals are more correlated from one channel to another as compared to noise during visual perception. Emulated VEP signals contaminated with noise are used to show the noise reduction ability of PCA. These noise reduced VEP signals are analysed in the gamma spectral band to classify alcoholics and non-alcoholics with a Fuzzy ARTMAP (FA) neural network. A zero phase Butterworth digital filter is used to extract gamma band power in spectral range of 30 to 50 Hz from these noise reduced VEP signals. The results using 800 VEP signals give an average FA classification of 92.50 % with the application of PCA and 83.33 % without the application of PCA.

  15. Tunable multichannel absorber composed of graphene and doped periodic structures

    Science.gov (United States)

    Kong, Xiang-kun; Shi, Xiang-zhu; Mo, Jin-jun; Fang, Yun-tuan; Chen, Xin-lei; Liu, Shao-bin

    2017-01-01

    A new design for a tunable multichannel compact absorber, which is achieved by using an asymmetric photonic crystal with graphene monolayers, is theoretically proposed. The graphene monolayers are periodically embedded into the first and last dielectric layers. The absorption, reflection, and transmission spectra of the absorber are studied numerically. A perfect absorption channel is achieved because of impedance matching, and channel number can be modulated by changing periodic number. The characteristic properties of the absorption channel depend on graphene conductivity, which can be controlled via the gate voltage. The proposed structure works as a perfect absorber that is independent from polarization. It has potential applications in the design of multichannel filters, thermal detectors, and electromagnetic wave energy collectors.

  16. Mimicking multi-channel scattering with single-channel approaches

    OpenAIRE

    Grishkevich, Sergey; Schneider, Philipp-Immanuel; Vanne, Yulian V.; Saenz, Alejandro

    2009-01-01

    The collision of two atoms is an intrinsic multi-channel (MC) problem as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold 6Li and 87Rb atoms in the ground state and in the ...

  17. Efficient sequential compression of multi-channel biomedical signals

    OpenAIRE

    Capurro, Ignacio; Lecumberry, Federico; Martín, Álvaro; Ramírez, Ignacio; Rovira, Eugenio; Seroussi, Gadiel

    2016-01-01

    This work proposes lossless and near-lossless compression algorithms for multi-channel biomedical signals. The algorithms are sequential and efficient, which makes them suitable for low-latency and low-power signal transmission applications. We make use of information theory and signal processing tools (such as universal coding, universal prediction, and fast online implementations of multivariate recursive least squares), combined with simple methods to exploit spatial as well as temporal re...

  18. Multi-channel analyzer controlled by applet and flash

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Both java applet and flash were applied to emulate virtual panel of multi-channel pulse height analyzer (MCA), and Microsoft IE browser was used to control MCA through internet to measure the γ-ray energy spectrum of 137Cs. It Was shown that most of the work completed by applet can be done by flash too, and with flash, more beautiful panel of the remote controlled instruments can be easily designed.

  19. A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope

    Directory of Open Access Journals (Sweden)

    Yunhai Zhang

    2013-01-01

    Full Text Available We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments.

  20. Multichannel optical atomic magnetometer operating in unshielded environment

    CERN Document Server

    Bevilacqua, Giuseppe; Chessa, Piero; Dancheva, Yordanka

    2016-01-01

    A multi-channel atomic magnetometer operating in an unshielded environment is described and characterised. The magnetometer is based on D1 optical pumping and D2 polarimetry of Cs vapour contained in gas-buffered cells. Several technical implementations are described and discussed in detail. The demonstrated sensitivity of the setup is 100fT/Hz^1/2 when operating in the difference mode.

  1. ITERATIVE MULTICHANNEL BLIND DECONVOLUTION METHOD FOR TEMPORALLY COLORED SOURCES

    Institute of Scientific and Technical Information of China (English)

    Zhang Mingjian; Wei Gang

    2004-01-01

    An iterative separation approach, i.e. source signals are extracted and removed one by one, is proposed for multichannel blind deconvolution of colored signals. Each source signal is extracted in two stages: a filtered version of the source signal is first obtained by solving the generalized eigenvalue problem, which is then followed by a single channel blind deconvolution based on ensemble learning. Simulation demonstrates the capability of the approach to perform efficient mutichannel blind deconvolution.

  2. [Programmable multichannel electrophysiological stimulator based on MCU and CPLD platform].

    Science.gov (United States)

    Zheng, Yi; Wu, Xiao-Mei; Fang, Zu-Xiang

    2008-01-01

    According to the instruction of the operator, the designed programmable multichannel stimulator will deliver stimuli with an assigned amplitude and a proper width to the electrode-array in various modes. Each stimulation time is controlled by the internal timer of the MCU, while the stimulated electrodes' spatial parameter is controlled by the CPLD. Having abandoned conventional isolation using the transformer, we have adapted optical coupling and stable float ground connection to achieve the safety standard required by physiological measurements.

  3. Relativistic Multichannel Theory: Theoretical Study of C+ Autoionization States

    Institute of Scientific and Technical Information of China (English)

    XIA Dan; ZHANG Shi-Zhong; PENG Yong-Lun; LI Jia-Ming

    2003-01-01

    Based on relativistic multichannel theory, the autoionization states of C+ are studied. We calculate all the autoionization states in the energy region of 193900 ~ 231700cm"1, and the results are in good agreement with the experimental data. The energy structure we obtain will be important in the dielectronic recombination processes, which plays a key role in determining the abundance of carbon in a nebula.

  4. Ultracold Long-Range Rydberg Molecules with Complex Multichannel Spectra

    Science.gov (United States)

    Eiles, Matthew; Greene, Chris

    2016-05-01

    A generalized class of exotic long-range Rydberg molecules consisting of a multichannel Rydberg atom bound to a distant ground state atom by the Rydberg electron is predicted. These molecules are characterized by the rich physics provided by the strongly perturbed multichannel Rydberg spectra of divalent atoms, in contrast to the regular Rydberg series of the alkali atoms used to form Rydberg molecules to date. These multichannel Rydberg molecules exhibit favorable properties for laser excitation, because states exist where the quantum defect varies strongly with the principal quantum number n. In particular, the nd Rydberg state of calcium becomes nearly degenerate with states of high orbital angular momentum over the range 17 molecular states are predicted to occur in the low- J states of silicon, which are strongly perturbed due to channel interactions between Rydberg series leading to the spin-orbit split ionization thresholds. These interactions manifest themselves in potential curves exhibiting two distinct length scales, providing novel opportunities for quantum manipulation. Supported in part by the National Science Foundation under Grant No. PHY-1306905.

  5. Multichannel linear descriptors analysis for sustained attention-related electroencephalography.

    Science.gov (United States)

    Liu, Tian; Yan, Nan; Chen, Yanni; Wang, Jue

    2013-08-07

    This study investigated the differences in brain functional state between sustained attention and ignoring task conditions using the electroencephalography in association with sustained attention to response task (SART) performance. Multichannel electroencephalography data were obtained from 10 male healthy volunteers while performing the SART. Three multichannel linear descriptors, that is spatial complexity (Ω), field strength (Σ), and frequency of field changes (Φ), were applied to analyze three frequency bands (θ, α, and β) for sustained attention and ignoring task conditions. The experimental results showed that participants had a significantly lower Ω value in the θ and α band in the SART state. The Σ value was significantly higher in each frequency band of interest in almost all region of interest areas during SART performance. In addition, the Φ value was significantly lower in the θ band and significantly higher in the β band during the sustained attention condition. The results indicated that multichannel linear descriptors could show the differences in brain functions between sustained attention and ignoring task conditions, and might be used to evaluate disorders with an attentional dysfunction.

  6. Multi-channel MAC Protocol in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Yongli Sun

    2013-11-01

    Full Text Available Since cognitive wireless network (CRN has the characteristic of secondary use, it can enable the device to dynamically access available spectrum without interference to primary users (PUs, which can effectively alleviate contradiction between the lack of spectrum resources and the growing demand for wireless access. However, Medium Access Control (MAC protocol as CRN core components, can achieve competition access of the licensed spectrum and coordination control, which will maximize spectrum utilization efficiency and network throughput. The contribution of this survey is threefold. First, we analyze the characteristics of the existed multi- channel MAC protocol in CRN; Second, according to the different ways of spectrum access in CRNs, the multi-channel MAC protocols are classified into time-slotted based MAC protocol, control channel based MAC protocol and hybrid MAC protocol, and the paper emphatically analyzed the advantages and disadvantages of these multi-channel MAC protocols; Finally, the paper explores the difficulties and the challenges of multi-channel MAC protocols design in cognitive wireless network.

  7. Exploring new bands in modified multichannel regression SST algorithms for the next-generation infrared sensors at NOAA

    Science.gov (United States)

    Petrenko, B.; Ignatov, A.; Kramar, M.; Kihai, Y.

    2016-05-01

    Multichannel regression algorithms are widely used to retrieve sea surface temperature (SST) from infrared observations with satellite radiometers. Their theoretical foundations were laid in the 1980s-1990s, during the era of the Advanced Very High Resolution Radiometers which have been flown onboard NOAA satellites since 1981. Consequently, the multi-channel and non-linear SST algorithms employ the bands centered at 3.7, 11 and 12 μm, similar to available in AVHRR. More recent radiometers carry new bands located in the windows near 4 μm, 8.5 μm and 10 μm, which may also be used for SST. Involving these bands in SST retrieval requires modifications to the regression SST equations. The paper describes a general approach to constructing SST regression equations for an arbitrary number of radiometric bands and explores the benefits of using extended sets of bands available with the Visible Infrared Imager Radiometer Suite (VIIRS) flown onboard the Suomi National Polar-orbiting Partnership (SNPP) and to be flown onboard the follow-on Joint Polar Satellite System (JPSS) satellites, J1-J4, to be launched from 2017-2031; Moderate Resolution Imaging Spectroradiometers (MODIS) flown onboard Aqua and Terra satellites; and the Advanced Himawari Imager (AHI) flown onboard the Japanese Himawari-8 satellite (which in turn is a close proxy of the Advanced Baseline Imager (ABI) to be flown onboard the future Geostationary Operational Environmental Satellites - R Series (GOES-R) planned for launch in October 2016.

  8. Design and Analysis of Microstrip Multi-Channeled Filter Using Photonic Crystal Branchy Defect

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A multi-channeled filter based on branchy defect in a microstrip photonic crystal was proposed. By introducing a branchy structure across the defect region, multiple defect modes will appear inside the photonic gap, leading to the multi-channeled filtering phenomenon. In comparison with the conventional multi-channeled filters, the proposed structure is more compact and tunable as far as the device volume and fabrication are concerned. The microwave experiment results are found in agreement with simulation results.

  9. Decision feedback equalization with multichannel readback in high-density optical recording

    Science.gov (United States)

    Gopalaswamy, Srinivasan; Vijaya Kumar, Bhagavatula

    1995-12-01

    Multi-channel readback using array heads has been reported in optical recording. A method to reduce both interference along and across the tracks using multi-channel readback is presented. In this method, the non-linear multi-channel decision feedback equalization is used to remove both forms of interference. Simulation results show good improvement (in performance) by using the multi-channel equalization. By this readback method, tracks can be brought closer, thus increasing the areal density. Another advantage of this method is the high data rate possible.

  10. 47 CFR 76.613 - Interference from a multichannel video programming distributor (MVPD).

    Science.gov (United States)

    2010-10-01

    ... (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76... any emission, radiation or induction which endangers the functioning of a radionavigation service...

  11. Inhibition of light tunneling for multichannel excitations in longitudinally modulated waveguide arrays

    CERN Document Server

    Lobanov, Valery E; Kartashov, Yaroslav V

    2010-01-01

    We consider evolution of multichannel excitations in longitudinally modulated waveguide arrays where refractive index either oscillates out-of-phase in all neighboring waveguides or when it is modulated in phase in several central waveguides surrounded by out-of-phase oscillating neighbors. Both types of modulations allow resonant inhibition of light tunneling, but only the modulation of latter type conserves the internal structure of multichannel excitations. We show that parameter regions where light tunneling inhibition is possible depend on the symmetry and structure of multichannel excitations. Antisymmetric multichannel excitations are more robust than their symmetric counterparts and experience nonlinearity-induced delocalization at higher amplitudes.

  12. Modular Air-Coupled Ultrasonic Multichannel System for Inline NDT

    Science.gov (United States)

    Bilcke, M.; Lust, P.; Naert, H.; Blomme, E.; Delrue, S.; Van Den Abeele, K.

    In many production processes it is important to detect in a very early stage basic errors in the fabricatedmaterial. If the errors are not visible from the exterior, ultrasonic inspection is a convenient technique,at least if the nature of the error influences the characteristics of sound passing through the material.Examples are local density variations in non-wovens, delaminations in composites, bad bondings inlaminates, inclusions, cracks or other artefacts in plastic or metal plates, etc. There are two major,difficult requirements imposed by industry to the used detection technique: the sensors shouldn't makephysical contact with the material and the speed of testing must be sufficiently high to enable testingin-line. The former requirement can be met by employing an air-coupled ultrasonic approach, the latterby using a multichannel system.We propose a modular air-coupled ultrasonic multichannel system. Each multichannel module contains12 air-coupled transducers and exists in a transmitter and a receiver version. The desired scan width isobtained by connecting several modules to each other. During the scanning all transducers are spatially fixed while the material is moving forward. This way, speeds up to 1m/s are possible, irrespective ofthe width of the material. To that purpose a FPGA based platform with parallel processing of largenumbers of data streams is implemented in the modules. This allows the implementation of all kind ofprocedures, going from point measurements to more sophisticated techniques. In spite of all measurements being performed in ambient air, the ultrasonic frequency is rather high(1 MHz), but lower frequencies are possible as well. The most obvious set-up of the modules is a through-transmission configuration. However the system can also be used in a pitch-catch configuration which isvery suitable for one-sided testing of thick materials. An examples established in the laboratory is shownto illustrate the performance.

  13. A Low-cost Multi-channel Analogue Signal Generator

    CERN Document Server

    Müller, F; The ATLAS collaboration; Shen, W; Stamen, R

    2009-01-01

    A scalable multi-channel analogue signal generator is presented. It uses a commercial low-cost graphics card with multiple outputs in a standard PC as signal source. Each color signal serves as independent channel to generate an analogue signal. A custom-built external PCB was developed to adjust the graphics card output voltage levels for a specific task, which needed differential signals. The system furthermore comprises a software package to program the signal shape. The signal generator was successfully used as independent test bed for the ATLAS Level-1 Trigger Pre-Processor, providing up to 16 analogue signals.

  14. Efficient sequential compression of multi-channel biomedical signals.

    Science.gov (United States)

    Capurro, Ignacio; Lecumberry, Federico; Martin, Alvaro; Ramirez, Ignacio; Rovira, Eugenio; Seroussi, Gadiel

    2016-06-21

    This work proposes lossless and near-lossless compression algorithms for multi-channel biomedical signals. The algorithms are sequential and efficient, which makes them suitable for low-latency and low-power signal transmission applications. We make use of information theory and signal processing tools (such as universal coding, universal prediction, and fast online implementations of multivariate recursive least squares), combined with simple methods to exploit spatial as well as temporal redundancies typically present in biomedical signals. The algorithms are tested with publicly available electroencephalogram and electrocardiogram databases, surpassing in all cases the current state of the art in near-lossless and lossless compression ratios.

  15. Resource allocation for multichannel broadcasting visible light communication

    Science.gov (United States)

    Le, Nam-Tuan; Jang, Yeong Min

    2015-11-01

    Visible light communication (VLC), which offers the possibility of using light sources for both illumination and data communications simultaneously, will be a promising incorporation technique with lighting applications. However, it still remains some challenges especially coverage because of field-of-view limitation. In this paper, we focus on this issue by suggesting a resource allocation scheme for VLC broadcasting system. By using frame synchronization and a network calculus QoS approximation, as well as diversity technology, the proposed VLC architecture and QoS resource allocation for the multichannel-broadcasting MAC (medium access control) protocol can solve the coverage limitation problem and the link switching problem of exhibition service.

  16. Multichannel Coherent Lightwave Systems: Practical Problems and Possible Solutions

    Science.gov (United States)

    Tanrikulu, Mustafa Okan

    1995-01-01

    An extensive field deployment of optical fiber has already undergone, and it is expected to replace the copper within the next twenty years. The ultimate goal in communications and computing industry is to make all optical networks possible in the near future. In this context, certain important practical problems that exist in multichannel coherent lightwave systems are studied, and possible solutions are provided in this dissertation. It is shown that the capacity of dual-filter FSK heterodyne lightwave systems can be enhanced by exploiting the interrelationship between the frequency separation and the amount of laser phase noise. Optimum choice of intermediate frequency filter bandwidth also improves the system capacity. The effect of finite intermediate frequency on the performance of ASK heterodyne lightwave systems is also studied. The results obtained show that certain finite choices of intermediate frequency allows ideal envelope detection. Thus, one can design a multichannel ASK heterodyne lightwave system with relatively small optical domain channel spacings as long as optimum values of intermediate frequency is used. Otherwise, either the channel spacings should be increased, which, in turn, reduces the system capacity, or an extra sensitivity penalty should be tolerated which translates into an increase in the system cost. It is also shown that the effect of finite intermediate frequency is more significant in negligible linewidth systems. On the other hand, non-negligible linewidth systems are more immune to the effects of finite intermediate frequency. However, the amount of channel spacing in a multichannel system significantly increases in the case of non-negligible linewidth systems due to spectral broadening of information bearing signal. The effect of crosstalk in multi-channel ASK heterodyne lightwave systems with polarization control is also studied, and the results obtained show that choice of intermediate frequency filter bandwidth, in

  17. The Single- and Multichannel Audio Recordings Database (SMARD)

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Jesper Rindom; Jensen, Søren Holdt

    2014-01-01

    A new single- and multichannel audio recordings database (SMARD) is presented in this paper. The database contains recordings from a box-shaped listening room for various loudspeaker and array types. The recordings were made for 48 different configurations of three different loudspeakers and four...... different microphone arrays. In each configuration, 20 different audio segments were played and recorded ranging from simple artificial sounds to polyphonic music. SMARD can be used for testing algorithms developed for numerous application, and we give examples of source localisation results....

  18. A Multi-channel AC Power Supply Controller

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A multi-channel AC power Supply controler developed recently by us was introdueed briefty in this paper.This controller is a computer controlled multi-electronic-switch device.The controller contains 16 independent channels in a standard box(440W×405D×125H mm).There is an electronic switch in each channel,the rated load power is≤1 kW.The main function of the controller is to set the state of electronic switch(ON/OFF)

  19. A multi-channel instrumentation system for biosignal recording.

    Science.gov (United States)

    Yu, Hong; Li, Pengfei; Xiao, Zhiming; Peng, Chung-Ching; Bashirullah, Rizwan

    2008-01-01

    This paper reports a highly integrated battery operated multi-channel instrumentation system intended for physiological signal recording. The mixed signal IC has been fabricated in standard 0.5microm 5V 3M-2P CMOS process and features 32 instrumentation amplifiers, four 8b SAR ADCs, a wireless power interface with Li-ion battery charger, low power bidirectional telemetry and FSM controller with power gating control for improved energy efficiency. The chip measures 3.2mm by 4.8mm and dissipates approximately 2.1mW when fully operational.

  20. A novel framework of multi-channel acoustic echo cancellation

    Institute of Scientific and Technical Information of China (English)

    HE Zhaoshui; XIE Shengli; FU Yuli

    2006-01-01

    Conventionally, multi-channel acoustic echo cancellation (AEC) achieves the goal by estimating the impulse responses of the local room. However, generally, conventional AEC methods have no unique solutions. Due to the strong correlation of the input signals, conventional methods are with many disadvantages. To overcome this problem, a new framework is proposed in this paper based on SIMO(single input multiple output) blind deconvolution. Under the new framework, we achieve the goal by identifying the impulse responses of distant room and avoiding the disadvantages of the conventional methods.

  1. Development of multichannel low-energy neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Arikawa, Y., E-mail: arikawa-y@ile.osaka-u.ac.jp; Nagai, T.; Abe, Y.; Kojima, S.; Sakata, S.; Inoue, H.; Utsugi, M.; Iwasa, Y.; Sarukura, N.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka (Japan); Murata, T. [Kumamoto University, 2-40-1 Kurokami, Kumamoto 860-8555 (Japan)

    2014-11-15

    A multichannel low-energy neutron spectrometer for down-scattered neutron (DSN) measurements in inertial confinement fusion (ICF) experiments has been developed. Our compact-size 256-channel lithium-glass-scintillator-based spectrometer has been implemented and tested in ICF experiments with the GEKKO XII laser. We have performed time calibration of the 256-channel analog-to-digital convertor system used for DSN measurements via X-ray pulse signals. We have clearly observed the DD-primary fusion neutron signal and have successfully studied the detector's impulse response. Our detector is soon to be implemented in future ICF experiments.

  2. Multichannel demultiplexer/demodulator technologies for future satellite communication systems

    Science.gov (United States)

    Ivancic, William D.; Budinger, James M.; Staples, Edward J.; Abramovitz, Irwin; Courtois, Hector A.

    1992-01-01

    NASA-Lewis' Space Electronics Div. supports ongoing research in advanced satellite communication architectures, onboard processing, and technology development. Recent studies indicate that meshed VSAT (very small aperture terminal) satellite communication networks using FDMA (frequency division multiple access) uplinks and TDMA (time division multiplexed) downlinks are required to meet future communication needs. One of the critical advancements in such a satellite communication network is the multichannel demultiplexer/demodulator (MCDD). The progress is described which was made in MCDD development using either acousto-optical, optical, or digital technologies.

  3. Multichannel Quantum Defect Theory a Quantum Poincaré Map

    CERN Document Server

    Leyvraz, F; Lombardi, M; Seligman, T H

    1999-01-01

    The multichannel quantum defect theory (MQDT) can be reinterpreted as a quantum Poincare map in representation of angular momentum. We chose a simplified model for Rydberg molecules where the limit classical map is known and MQDT delivers the exact quantization of this map, which is a finite unitary matrix by construction. The result has two important implications: On one hand we have a paradigm of a true quantum Poincare map without semi-classical input and on the other hand we get an entirely new insight into the significance of MQDT. We obtain a new signature of quantum chaos and a more reliable method to calculate eigenfunctions in MQDT.

  4. Multichannel scattering of charge carriers on quantum well heterostructures

    CERN Document Server

    Galiev, V I; Polupanov, A F; Goldis, E M; Tansli, T L

    2002-01-01

    An efficient numerical analytical method has been developed for finding continuum spectrum states in quantum well systems with arbitrary potential profiles that are described by coupled Schroedinger equations. Scattering states and S matrix have been built for the case of multichannel scattering in one-dimensional systems with quantum wells and their symmetry properties are obtained and analyzed. The method is applied for studying hole scattering by strained GaInAs-InGaAsP quantum wells. Coefficients of the hole transmission and reflection as well as delay time are calculated as functions of the energy of the incident hole for various values of parameters of structures and values of the momentum

  5. A Multi-Channel Setup to Study Fractures in Scintillators

    CERN Document Server

    Tantot, A; Briche, R; Lefèvre, G; Manier, B; Zaïm, N; Deschanel, S; Vanel, L; Di Stefano, P C F

    2016-01-01

    To investigate fractoluminescence in scintillating crystals used for particle detection, we have developed a multi-channel setup built around samples of double-cleavage drilled compression (DCDC) geometry in a controllable atmosphere. The setup allows the continuous digitization over hours of various parameters, including the applied load, and the compressive strain of the sample, as well as the acoustic emission. Emitted visible light is recorded with nanosecond resolution, and crack propagation is monitored using infrared lighting and camera. An example of application to Bi4Ge3O12 (BGO) is provided.

  6. A multi-channel setup to study fractures in scintillators

    Science.gov (United States)

    Tantot, A.; Bouard, C.; Briche, R.; Lefèvre, G.; Manier, B.; Zaïm, N.; Deschanel, S.; Vanel, L.; Di Stefano, P. C. F.

    2016-12-01

    To investigate fractoluminescence in scintillating crystals used for particle detection, we have developed a multi-channel setup built around samples of double-cleavage drilled compression (DCDC) geometry in a controllable atmosphere. The setup allows the continuous digitization over hours of various parameters, including the applied load, and the compressive strain of the sample, as well as the acoustic emission. Emitted visible light is recorded with nanosecond resolution, and crack propagation is monitored using infrared lighting and camera. An example of application to \\text{B}{{\\text{i}}4}\\text{G}{{\\text{e}}3}{{\\text{O}}12} (BGO) is provided.

  7. Intertwining technique for a system of difference Schroedinger equations and new exactly solvable multichannel potentials

    CERN Document Server

    Nieto, L M; Suzko, A A

    2003-01-01

    The intertwining operator technique is applied to difference Schroedinger equations with operator-valued coefficients. It is shown that these equations appear naturally when a discrete basis is used for solving a multichannel Schroedinger equation. New families of exactly solvable multichannel Hamiltonians are found.

  8. The use of service channels by citizens in the Netherlands: implications for multi-channel management

    NARCIS (Netherlands)

    Pieterson, Willem Jan; Ebbers, Wolfgang E.

    2008-01-01

    Many governmental organizations are changing their service channel management strategies to multi-channel management. However, very few empirical studies exist that explore how these multi-channel strategies should be shaped. In this article we test a number of hypotheses on citizens' channel use

  9. New theoretical methods for studies on electrons and positrons scattering involving multichannel processes

    CERN Document Server

    Lara, O

    1995-01-01

    continued fractions are now in progress. It is well known that multichannel effects strongly influence the low-energy electron scattering by atoms and molecules. Nevertheless, the inclusion of such effects on the calculations of scattering cross sections remains a considerable task for the area researches due to the complexity of the problem. In the present study we aim to develop a new theoretical method which can be efficiently applied to the multichannel scattering studies. Two new theoretical formalisms namely the Multichannel sup - C-Functional Method have been proposed. Both methods were developed on the base of well-known distorted-wave method combined with Schwinger variational principle. In addition, an integrative method proposed by Horacek and Sasakawa in 1983, the method of continued fractions is adapted by the first time to multichannel scatterings. Numerical test of these three methods were carried out through applications to solve the multichannel scattering problems involving the interaction o...

  10. Filterbank implementation for multi-channel sampling in fractional Fourier domain

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Reconstruction of a continuous time signal from its periodic nonuniform samples and multi-channel samples is fundamental for multi-channel parallel A/D and MIMO systems. In this paper,with a filterbank interpretation of sampling schemes,the efficient interpolation and reconstruction methods for periodic nonuniform sampling and multi-channel sampling in the fractional Fourier domain are presented. Firstly,the interpolation and sampling identities in the fractional Fourier domain are derived by the properties of the fractional Fourier transform. Then,the particularly efficient filterbank implementations for the periodic nonuniform sampling and the multi-channel sampling in the fractional Fourier domain are introduced. At last,the relationship between the multi-channel sampling and the filterbank in the fractional Fourier domain is investigated,which shows that any perfect reconstruction filterbank can lead to new sampling and reconstruction strategies.

  11. Filterbank implementation for multi-channel sampling in fractional Fourier domain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; TAO Ran; WANG Yue

    2009-01-01

    Reconstruction of a continuous time signal from its periodic nonuniform samples and multi-channel samples is fundamental for multi-channel parallel A/D and MIMO systems. In this paper, with a filter-bank interpretation of sampling schemes, the efficient interpolation and reconstruction methods for periodic nonuniform sampling and multi-channel sampling in the fractional Fourier domain are pre-sented. Firstly, the interpolation and sampling identities in the fractional Fourier domain are derived by the properties of the fractional Fourier transform. Then, the particularly efficient filterbank implementa-tions for the periodic nonuniform sampling and the multi-channel sampling in the fractional Fourier domain are introduced. At last, the relationship between the multi-channel sampling and the filterbank in the fractional Fourier domain is investigated, which shows that any perfect reconstruction filterbank can lead to new sampling and reconstruction strategies.

  12. Multi-channel sampling theorems for band-limited signals with fractional Fourier transform

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Multi-channel sampling for band-limited signals is fundamental in the theory of multi-channel parallel A/D environment and multiplexing wireless communication environment. As the fractional Fourier transform has been found wide applications in signal processing fields, it is necessary to consider the multi-channel sampling theorem based on the fractional Fourier transform. In this paper, the multi-channel sampling theorem for the fractional band-limited signal is firstly proposed, which is the generalization of the well-known sampling theorem for the fractional Fourier transform. Since the periodic nonuniformly sampled signal in the fractional Fourier domain has valuable applications, the reconstruction expression for the periodic nonuniformly sampled signal has been then obtained by using the derived multi-channel sampling theorem and the specific space-shifting and phase-shifting properties of the fractional Fourier transform. Moreover, by designing different fractional Fourier filters, we can obtain reconstruction methods for other sampling strategies.

  13. Dust and Smoke Detection for Multi-Channel Imagers

    Directory of Open Access Journals (Sweden)

    Wei Guo

    2010-10-01

    Full Text Available A detection algorithm of dust and smoke for application to satellite multi-channel imagers is introduced in this paper. The algorithm is simple and solely based on spectral and spatial threshold tests along with some uniformity texture. Detailed examinations of the threshold tests are performed along with explanations of the physical basis. The detection is performed efficiently at the pixel level and output is in the form of an index (or flag: 0 (no dust/smoke and 1 (dust/smoke. The detection algorithm is implemented sequentially and designed to run on segments of data instead of pixel by pixel for efficient processing. MODIS observations are used to test the operation and performance of the algorithm. The algorithm can capture heavy dust and smoke plumes very well over both land and ocean and therefore is used as a global detection algorithm. The method can be applied to any multi-channel imagers with channels at (or close to 0.47, 0.64, 0.86, 1.38, 2.26, 3.9, 11.0, 12.0 μm (such as current EOS/MODIS and future JPSS/VIIRS and GOES-R/ABI for the detection of dust and smoke. It can be used to operationally monitor the outbreak and dispersion of dust storms and smoke plumes that are potentially hazardous to our environment and impact climate.

  14. Separable Multichannel Momentum Space Potentials for Nuclear Reactions

    Science.gov (United States)

    Hlophe, Linda; Elster, Charlotte

    2016-09-01

    Many nuclei are deformed and their properties can be described using a rotational model. This involves defining a deformed surface of the nucleus and constructing the nucleon-nucleus interaction as a function of distance to the surface. Such a potential has non-zero matrix elements between different nuclear rotational states which are characterized by the spin-parity Iπ, leading to channel couplings. For specific reaction calculations, it is advantageous to have separable representations of the interaction matrix elements available. We develop separable representations following a scheme suggested by Ernst, Shakin, and Thaler (EST). Since optical potentials are complex and energy-dependent, the multichannel EST scheme is generalized to complex, energy-dependent separable potentials. In the case of proton-nucleus interactions the EST scheme is further extended to include charged particles. The multichannel EST scheme is applied to nucleon scattering off 12C, where the first two excited states (Iπ =2+ ,4+) are taken into account. Research for this project was supported in part by the US Department of Energy, Office of Science of Nuclear Physics under Contract No. DE-FG02-93ER40756.

  15. Design of highly sensitive multichannel bimetallic photonic crystal fiber biosensor

    Science.gov (United States)

    Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, Abdelhamid A.; El Deeb, Walid S.; Obayya, Salah S. A.

    2016-10-01

    A design of a highly sensitive multichannel biosensor based on photonic crystal fiber is proposed and analyzed. The suggested design has a silver layer as a plasmonic material coated by a gold layer to protect silver oxidation. The reported sensor is based on detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, which offers the possibility of multichannel/multianalyte sensing. The numerical results are obtained using a finite element method with perfect matched layer boundary conditions. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High-refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained according to the quasi TM and quasi TE modes of the proposed sensor, respectively. Further, the reported design can be used as a self-calibration biosensor within an unknown analyte refractive index ranging from 1.33 to 1.35 with high linearity and high accuracy. Moreover, the suggested biosensor has advantages in terms of compactness and better integration of microfluidics setup, waveguide, and metallic layers into a single structure.

  16. Optical multichannel analyzer techniques for high resolution optical spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chao, J.L.

    1980-06-01

    The development of optical multichannel analyzer techniques for UV/VIS spectroscopy is presented. The research focuses on the development of spectroscopic techniques for measuring high resolution spectral lineshape functions from the exciton phosphorescence in H/sub 2/-1,2,4,5-tetrachlorobenzene. It is found that the temperature dependent frequency shifts and widths confirm a theoretical model based on an exchange theory. The exchange of low energy phonon modes which couple with excited state exciton transitions is shown to display the proper temperature dependent behavior. In addition to the techniques for using the optical multichannel analyzer (OMA) to perform low light level target integration, the use of the OMA for capturing spectral information in transient pulsed laser applications is discussed. An OMP data acquisition system developed for real-time signal processng is described. Both hardware and software interfacing considerations for control and data acquisition by a microcomputer are described. The OMA detector is described in terms of the principles behind its photoelectron detection capabilities and its design is compared with other optoelectronic devices.

  17. A Multimedia Application: Spatial Perceptual Entropy of Multichannel Audio Signals

    Directory of Open Access Journals (Sweden)

    Shuixian Chen

    2010-01-01

    Full Text Available Usually multimedia data have to be compressed before transmitting, and higher compression rate, or equivalently lower bitrate, relieves the load of communication channels but impacts negatively the quality. We investigate the bitrate lower bound for perceptually lossless compression of a major type of multimedia—multichannel audio signals. This bound equals to the perceptible information rate of the signals. Traditionally, Perceptual Entropy (PE, based primarily on monaural hearing measures the perceptual information rate of individual channels. But PE cannot measure the spatial information captured by binaural hearing, thus is not suitable for estimating Spatial Audio Coding (SAC bitrate bound. To measure this spatial information, we build a Binaural Cue Physiological Perception Model (BCPPM on the ground of binaural hearing, which represents spatial information in the physical and physiological layers. This model enables computing Spatial Perceptual Entropy (SPE, the lower bitrate bound for SAC. For real-world stereo audio signals of various types, our experiments indicate that SPE reliably estimates their spatial information rate. Therefore, “SPE plus PE” gives lower bitrate bounds for communicating multichannel audio signals with transparent quality.

  18. Optimized multichannel decomposition for texture segmentation using Gabor filter bank

    Science.gov (United States)

    Nezamoddini-Kachouie, Nezamoddin; Alirezaie, Javad

    2004-05-01

    Texture segmentation and analysis is an important aspect of pattern recognition and digital image processing. Previous approaches to texture analysis and segmentation perform multi-channel filtering by applying a set of filters to the image. In this paper we describe a texture segmentation algorithm based on multi-channel filtering that is optimized using diagonal high frequency residual. Gabor band pass filters with different radial spatial frequencies and different orientations have optimum resolution in time and frequency domain. The image is decomposed by a set of Gabor filters into a number of filtered images; each one contains variation of intensity on a sub-band frequency and orientation. The features extracted by Gabor filters have been applied for image segmentation and analysis. There are some important considerations about filter parameters and filter bank coverage in frequency domain. This filter bank does not completely cover the corners of the frequency domain along the diagonals. In our method we optimize the spatial implementation for the Gabor filter bank considering the diagonal high frequency residual. Segmentation is accomplished by a feedforward backpropagation multi-layer perceptron that is trained by optimized extracted features. After MLP is trained the input image is segmented and each pixel is assigned to the proper class.

  19. A duple watermarking strategy for multi-channel quantum images

    Science.gov (United States)

    Yan, Fei; Iliyasu, Abdullah M.; Sun, Bo; Venegas-Andraca, Salvador E.; Dong, Fangyan; Hirota, Kaoru

    2015-05-01

    Utilizing a stockpile of efficient transformations consisting of channel of interest, channel swapping, and quantum Fourier transforms, a duple watermarking strategy on multi-channel quantum images is proposed. It embeds the watermark image both into the spatial domain and the frequency domain of the multi-channel quantum carrier image, while also providing a quantum measurement-based algorithm to generate an unknown key that is used to protect the color information, which accompanies another key that is mainly used to scramble the spatial content of the watermark image in order to further safeguard the copyright of the carrier image. Simulation-based experiments using a watermark logo and nine building images as watermark image and carrier images, respectively, offer a duple protection for the copyright of carrier images in terms of the visible quality of the watermarked images. The proposed stratagem advances available literature in the quantum watermarking research field and sets the stage for the applications aimed at quantum data protection.

  20. Very low cost multichannel analyzer with some additional features

    Science.gov (United States)

    Tudyka, Konrad; Bluszcz, Andrzej

    2011-12-01

    In this paper we present a multichannel analyzer (MCA) based on a digital signal controller (DSC). The multichannel analyzer is characterized by a very low cost and an additional feature of recording time intervals between pulses. The total cost of electronic parts used in construction of the MCA is around 50 USD. The electronic circuit is based on dsPIC30F2020 DSC unit from Microchip. The device has a 10-bit analogue-to-digital converter (ADC) which can sample and convert 2 samples per μs. The DSC samples the input voltage continuously and detects incoming pulses. The data belonging to a detected pulse and its time stamp are sent to a PC on-line. The analysis of data stored on the PC is performed off-line with the help of a genetic algorithm (GA) used to fit the pulse shape function. This allows determination of amplitude of each individual pulse. The effective resolution varies with the pulse length and is typically 1000 channels for pulses approximately 4 μs long.

  1. A Multimedia Application: Spatial Perceptual Entropy of Multichannel Audio Signals

    Directory of Open Access Journals (Sweden)

    Chen Shuixian

    2010-01-01

    Full Text Available Usually multimedia data have to be compressed before transmitting, and higher compression rate, or equivalently lower bitrate, relieves the load of communication channels but impacts negatively the quality. We investigate the bitrate lower bound for perceptually lossless compression of a major type of multimedia—multichannel audio signals. This bound equals to the perceptible information rate of the signals. Traditionally, Perceptual Entropy (PE, based primarily on monaural hearing measures the perceptual information rate of individual channels. But PE cannot measure the spatial information captured by binaural hearing, thus is not suitable for estimating Spatial Audio Coding (SAC bitrate bound. To measure this spatial information, we build a Binaural Cue Physiological Perception Model (BCPPM on the ground of binaural hearing, which represents spatial information in the physical and physiological layers. This model enables computing Spatial Perceptual Entropy (SPE, the lower bitrate bound for SAC. For real-world stereo audio signals of various types, our experiments indicate that SPE reliably estimates their spatial information rate. Therefore, "SPE plus PE" gives lower bitrate bounds for communicating multichannel audio signals with transparent quality.

  2. Multichannel electrotactile feedback for simultaneous and proportional myoelectric control

    Science.gov (United States)

    Patel, Gauravkumar K.; Dosen, Strahinja; Castellini, Claudio; Farina, Dario

    2016-10-01

    Objective. Closing the loop in myoelectric prostheses by providing artificial somatosensory feedback to the user is an important need for prosthetic users. Previous studies investigated feedback strategies in combination with the control of one degree of freedom of simple grippers. Modern hands, however, are sophisticated multifunction systems. In this study, we assessed multichannel electrotactile feedback integrated with an advanced method for the simultaneous and proportional control of individual fingers of a dexterous hand. Approach. The feedback used spatial and frequency coding to provide information on the finger positions (normalized flexion angles). A comprehensive set of conditions have been investigated in 28 able-bodied subjects, including feedback modalities (visual, electrotactile and no feedback), control tasks (fingers and grasps), systems (virtual and real hand), control methods (ideal and realistic) and range of motion (low and high). The task for the subjects was to operate the hand using closed-loop myoelectric control and generate the desired movement (e.g., selected finger or grasp at a specific level of closure). Main results. The subjects could perceive the multichannel and multivariable electrotactile feedback and effectively exploit it to improve the control performance with respect to open-loop grasping. The improvement however depended on the reliability of the feedforward control, with less consistent control exhibiting performance trends that were more complex across the conditions. Significance. The results are promising for the potential application of advanced feedback to close the control loop in sophisticated prosthetic systems.

  3. The EUMETSAT sea ice concentration climate data record

    Science.gov (United States)

    Tonboe, Rasmus T.; Eastwood, Steinar; Lavergne, Thomas; Sørensen, Atle M.; Rathmann, Nicholas; Dybkjær, Gorm; Toudal Pedersen, Leif; Høyer, Jacob L.; Kern, Stefan

    2016-09-01

    An Arctic and Antarctic sea ice area and extent dataset has been generated by EUMETSAT's Ocean and Sea Ice Satellite Application Facility (OSISAF) using the record of microwave radiometer data from NASA's Nimbus 7 Scanning Multichannel Microwave radiometer (SMMR) and the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager and Sounder (SSMIS) satellite sensors. The dataset covers the period from October 1978 to April 2015 and updates and further developments are planned for the next phase of the project. The methodology for computing the sea ice concentration uses (1) numerical weather prediction (NWP) data input to a radiative transfer model for reduction of the impact of weather conditions on the measured brightness temperatures; (2) dynamical algorithm tie points to mitigate trends in residual atmospheric, sea ice, and water emission characteristics and inter-sensor differences/biases; and (3) a hybrid sea ice concentration algorithm using the Bristol algorithm over ice and the Bootstrap algorithm in frequency mode over open water. A new sea ice concentration uncertainty algorithm has been developed to estimate the spatial and temporal variability in sea ice concentration retrieval accuracy. A comparison to US National Ice Center sea ice charts from the Arctic and the Antarctic shows that ice concentrations are higher in the ice charts than estimated from the radiometer data at intermediate sea ice concentrations between open water and 100 % ice. The sea ice concentration climate data record is available for download at www.osi-saf.org, including documentation.

  4. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph

    Directory of Open Access Journals (Sweden)

    Kristen M. Warren

    2016-03-01

    Full Text Available Photoplethysmographic (PPG waveforms are used to acquire pulse rate (PR measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA, limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data.

  5. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph.

    Science.gov (United States)

    Warren, Kristen M; Harvey, Joshua R; Chon, Ki H; Mendelson, Yitzhak

    2016-03-07

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data.

  6. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph

    Science.gov (United States)

    Warren, Kristen M.; Harvey, Joshua R.; Chon, Ki H.; Mendelson, Yitzhak

    2016-01-01

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data. PMID:26959034

  7. A Comparative Evaluation of Humphrey Perimetry and the Multi-channel Pattern Visual Evoked Potentials

    Institute of Scientific and Technical Information of China (English)

    Caiping Hu; Lezheng Wu; De-Zheng Wu; Shixian Long

    2000-01-01

    Purposes: To compare the multi-channel pattern visual evoked potentials to Humphrey perimetry in the assessment of central visual function in primary open angle glaucoma.Methods: The multi-channel checkerboard reversal PVEPs waves to full-field and half-field stimulus of 25 normal persons and 74 patients with primary open angle glaucoma were recorded and analyzed, All patients were examined using Humphrey Field Analyzer. The area of visual field corresponding to the area of retina stimulated during multi-channel PVEPs testing were analysed, straight-line correlation and regression analyses of the various multi-channel PVEPs parameters and the total dB losses were performed.Results: The multi-channel PVEPs demonstrated a low detection rate compared with Humprey perimetry in the early glaucoma, absolute latency and field loss were correlated in the late stage of glaucoma, and absolute amplitude and field loss were not correlated.Conclusions: In relation to signalling “early” loss the multi-channel PVEPs was inferior to Humphrey perimetry, in late loss of primary open angle glaucoma, multi-channel PVEPs can provide a valuable, objective complement to Humphrey perimetry.

  8. Accuracy Assessment for Multi-Channel ECG Waveforms Using Soft Computing Methodologies

    Directory of Open Access Journals (Sweden)

    Menta Srinivasulu

    2014-07-01

    Full Text Available ECG waveform rhythmic analysis is very important. In recent trends, analysis processes of ECG waveform applications are available in smart devices. Still, existing methods are not able to accomplish the complete accuracy assessment while classify the multi-channel ECG waveforms. In this paper, proposed analysis of accuracy assessment of the classification of multi-channel ECG waveforms using most popular Soft Computing algorithms. In this research, main focus is on the better rule generation to analyze the multi-channel ECG waveforms. Analysis is mainly done inSoft Computing methods like the Decision Trees with different pruning analysis, Logistic Model Trees with different regression process and Support Vector Machine with Particle Swarm Optimization (SVM-PSO. All these analysis methods are trained and tested with MIT-BIH 12 channel ECG waveforms. Before trained these methods, MSO-FIR filter should be used as data preprocessing for removal of noise from original multi-channel ECG waveforms. MSO technique is used for automatically finding out the cutoff frequency of multichannel ECG waveforms which is used in low-pass filtering process. The classification performance is discussed using mean squared error, member function, classification accuracy, complexity of design, and area under curve on MIT-BIH data. Additionally, this research work is extended for the samples of multi-channel ECG waveforms from the Scope diagnostic center, Hyderabad. Our study assets the best process using the Soft Computing methods for analysis of multi-channel ECG waveforms.

  9. Characteristics of Arctic Ocean ice determined from SMMR data for 1979 - Case studies in the seasonal sea ice zone

    Science.gov (United States)

    Anderson, M. R.; Crane, R. G.; Barry, R. G.

    1985-01-01

    Sea ice data derived from the Scanning Multichannel Microwave Radiometer are examined for sections of the Arctic Ocean during early summer 1979. The temporary appearance of spuriously high multiyear ice fractions in the seasonal ice zones of the Kara and Barents Seas is a result of surface melt phenomena and the relative responses of the different channels to these effects. These spurious signatures can provide early identification of melt onset and additional information on surface characteristics.

  10. Updated Multichannel Infrared Solar Spectrograph at Purple Mountain Observatory

    Institute of Scientific and Technical Information of China (English)

    黎辉; 尤建圻; 吴琴娣; 于兴凤

    2002-01-01

    We describe the newly updated multichannel infrared solar spectrograph at the Purple Mountain Observatory that now uses three Apogee APTp grade i scientific CCDs as its detectors and works at three wavelengths, He I 10830 , Call 8542 and Ha, simultaneously. The spectral resolutions of these lines are 0.04776, 0.05113 and 0.05453 per pixel, respectively. Some observation examples are presented. The observed profiles of the three lines demonstrate that redshift and asymmetry exist in the impulsive phase of the given disc flare and both blueshift and redshift exist in the presented flare spray in the impulsive phase of a limb flare. They also indicate that horizontal expansion exists in addition to the quick radial motion in the flare spray.

  11. A scalable, fast and multichannel arbitrary waveform generator

    CERN Document Server

    Baig, Muhammad Tanveer; Wiese, Andreas; Heidbrink, Stefan; Ziolkowski, Michael; Wunderlich, Christof

    2013-01-01

    This article reports on development of a multichannel arbitrary waveform generator (MAWG), which simultaneously generates arbitrary voltage waveforms on 24 independent channels with a dynamic update rate of up to 25 Msps. A real-time execution of a single waveform and/or sequence of multiple waveforms in succession, with a user programmable arbitrary sequence order is provided under the control of a stand-alone sequencer circuit implemented using an FPGA. The device is operated using an internal clock and can be synced to other devices by means of the TTL pulses. The device can be used for output voltages in the range of up to +-9 V with a drift rate below +-10 uV/min and a maximum deviation less than +- 300 uVpp over a period of two hours.

  12. Detection of forced oscillations in power systems with multichannel methods

    Energy Technology Data Exchange (ETDEWEB)

    Follum, James D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-09-30

    The increasing availability of high fidelity, geographically dispersed measurements in power systems improves the ability of researchers and engineers to study dynamic behaviors in the grid. One such behavior that is garnering increased attention is the presence of forced oscillations. Power system engineers are interested in forced oscillations because they are often symptomatic of the malfunction or misoperation of equipment. Though the resulting oscillation is not always large in amplitude, the root cause may be serious. In this report, multi-channel forced oscillation detection methods are developed. These methods leverage previously developed detection approaches based on the periodogram and spectral-coherence. Making use of geographically distributed channels of data is shown to improved detection performance and shorten the delay before an oscillation can be detected in the online environment. Results from simulated and measured power system data are presented.

  13. Automatic landslide and mudflow detection method via multichannel sparse representation

    Science.gov (United States)

    Chao, Chen; Zhou, Jianjun; Hao, Zhuo; Sun, Bo; He, Jun; Ge, Fengxiang

    2015-10-01

    Landslide and mudflow detection is an important application of aerial images and high resolution remote sensing images, which is crucial for national security and disaster relief. Since the high resolution images are often large in size, it's necessary to develop an efficient algorithm for landslide and mudflow detection. Based on the theory of sparse representation and, we propose a novel automatic landslide and mudflow detection method in this paper, which combines multi-channel sparse representation and eight neighbor judgment methods. The whole process of the detection is totally automatic. We make the experiment on a high resolution image of ZhouQu district of Gansu province in China on August, 2010 and get a promising result which proved the effective of using sparse representation on landslide and mudflow detection.

  14. Timing optimization utilizing order statistics and multichannel digital silicon photomultipliers.

    Science.gov (United States)

    Mandai, Shingo; Venialgo, Esteban; Charbon, Edoardo

    2014-02-01

    We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have demonstrated the ability of the MD-SiPM to detect multiple photons, and we verified the advantage of detecting multiple photons assuming incoming photons follow a Gaussian distribution. We have also shown the advantage of utilizing multiple timestamps for estimating time-of-arrivals more accurately. This estimation technique can be widely available in various applications, which have a certain probability density function of incoming photons, such as a scintillator or a laser source.

  15. On multichannel film dosimetry with channel-independent perturbations

    CERN Document Server

    Méndez, Ignasi; Hudej, Rihard; Strojnik, Andrej; Casar, Božidar

    2014-01-01

    Purpose: Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are the weighted mean method and the method put forth by Micke et al and Mayer et al. The purpose of this work was to compare their results and to develop a generalized channel-independent perturbations framework in which both methods enter as special cases. Methods: Four models of channel-independent perturbations were compared: weighted mean, Micke-Mayer method, uniform distribution and truncated normal distribution. A closed-form formula to calculate film doses and the associated Type B uncertainty for all four models was deduced. To evaluate the models, film dose distributions were compared with planned and measured dose distributions. At the same time, several elements of the dosimetry process were compared: film type EBT2 versus EBT3, different waiting-time windows, reflection mode versus transmission mode scanning, and planned versus measured dose distribution for film calibration and for gamma-...

  16. Stacked, Filtered Multi-Channel X-Ray Diode Array

    Energy Technology Data Exchange (ETDEWEB)

    MacNeil, Lawrence P. [National Security Technologies, LLC; Dutra, Eric C. [National Security Technologies, LLC; Raphaelian, Mark; Compton, Steven [Lawrence Livermore National Laboratory; Jacoby, Barry [Lawrence Livermore National Laboratory

    2015-08-01

    This system meets the need for a low-cost, robust X-ray diode array to use for experiments in hostile environments on multiple platforms, and for experiments utilizing forces that may destroy the diode(s). Since these uses require a small size with a minimal single line-of-sight, a parallel array often cannot be used. So a stacked, filtered multi-channel X-ray diode array was developed that was called the MiniXRD. The design was modeled, built, and tested at National Security Technologies, LLC (NSTec) Livermore Operations (LO) to determine fundamental characteristics. Then, several different systems were fielded as ancillary “ridealong” diagnostics at several national facilities to allow us to iteratively improve the design and usability. Presented here are design considerations and experimental results. This filtered diode array is currently at Technical Readiness Level (TRL) 6.

  17. Multi-channel detector readout method and integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Beuville, Eric; Pedrali-Noy, Marzio

    2004-05-18

    An integrated circuit which provides multi-channel detector readout from a detector array. The circuit receives multiple signals from the elements of a detector array and compares the sampled amplitudes of these signals against a noise-floor threshold and against one another. A digital signal is generated which corresponds to the location of the highest of these signal amplitudes which exceeds the noise floor threshold. The digital signal is received by a multiplexing circuit which outputs an analog signal corresponding the highest of the input signal amplitudes. In addition a digital control section provides for programmatic control of the multiplexer circuit, amplifier gain, amplifier reset, masking selection, and test circuit functionality on each input thereof.

  18. Multi-channel detector readout method and integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Beuville, Eric; Pedrali-Noy, Marzio

    2006-12-12

    An integrated circuit which provides multi-channel detector readout from a detector array. The circuit receives multiple signals from the elements of a detector array and compares the sampled amplitudes of these signals against a noise-floor threshold and against one another. A digital signal is generated which corresponds to the location of the highest of these signal amplitudes which exceeds the noise floor threshold. The digital signal is received by a multiplexing circuit which outputs an analog signal corresponding the highest of the input signal amplitudes. In addition a digital control section provides for programmatic control of the multiplexer circuit, amplifier gain, amplifier reset, masking selection, and test circuit functionality on each input thereof.

  19. A scalable correlator for multichannel diffuse correlation spectroscopy

    Science.gov (United States)

    Stapels, Christopher J.; Kolodziejski, Noah J.; McAdams, Daniel; Podolsky, Matthew J.; Fernandez, Daniel E.; Farkas, Dana; Christian, James F.

    2016-03-01

    Diffuse correlation spectroscopy (DCS) is a technique which enables powerful and robust non-invasive optical studies of tissue micro-circulation and vascular blood flow. The technique amounts to autocorrelation analysis of coherent photons after their migration through moving scatterers and subsequent collection by single-mode optical fibers. A primary cost driver of DCS instruments are the commercial hardware-based correlators, limiting the proliferation of multi-channel instruments for validation of perfusion analysis as a clinical diagnostic metric. We present the development of a low-cost scalable correlator enabled by microchip-based time-tagging, and a software-based multi-tau data analysis method. We will discuss the capabilities of the instrument as well as the implementation and validation of 2- and 8-channel systems built for live animal and pre-clinical settings.

  20. A multichannel nanosensor for instantaneous readout of cancer drug mechanisms

    Science.gov (United States)

    Rana, Subinoy; Le, Ngoc D. B.; Mout, Rubul; Saha, Krishnendu; Tonga, Gulen Yesilbag; Bain, Robert E. S.; Miranda, Oscar R.; Rotello, Caren M.; Rotello, Vincent M.

    2015-01-01

    Screening methods that use traditional genomic, transcriptional, proteomic and metabonomic signatures to characterize drug mechanisms are known. However, they are time consuming and require specialized equipment. Here, we present a high-throughput multichannel sensor platform that can profile the mechanisms of various chemotherapeutic drugs in minutes. The sensor consists of a gold nanoparticle complexed with three different fluorescent proteins that can sense drug-induced physicochemical changes on cell surfaces. In the presence of cells, fluorescent proteins are rapidly displaced from the gold nanoparticle surface and fluorescence is restored. Fluorescence ‘turn on’ of the fluorescent proteins depends on the drug-induced cell surface changes, generating patterns that identify specific mechanisms of cell death induced by drugs. The nanosensor is generalizable to different cell types and does not require processing steps before analysis, offering an effective way to expedite research in drug discovery, toxicology and cell-based sensing.

  1. Multi-channel Hybrid Access Femtocells: A Stochastic Geometric Analysis

    CERN Document Server

    Zhong, Yi

    2011-01-01

    For two-tier networks consisting of macrocells and femtocells, the channel access mechanism can be configured to be open access, closed access, or hybrid access. Hybrid access arises as a compromise between open and closed access mechanisms, in which a fraction of available spectrum resource is shared to nonsubscribers while the remaining reserved for subscribers. This paper focuses on a hybrid access mechanism for multi-channel femtocells which employ orthogonal spectrum access schemes. Considering a randomized channel assignment strategy, we analyze the performance in the downlink. Using stochastic geometry as technical tools, we derive the distributions of signal-to-interference-plus-noise ratios, and mean achievable rates, of both nonsubscribers and subscribers. The established expressions are amenable to numerical evaluation, and shed key insights into the performance tradeoff between subscribers and nonsubscribers. The analytical results are corroborated by numerical simulations.

  2. Multi-channel and sharp angular spatial filters based on one-dimensional photonic crystals

    Institute of Scientific and Technical Information of China (English)

    Shaoji Jiang; Jianrong Li; Jijia Tang; Hezhou Wang

    2006-01-01

    A photonic heterostructure with multi-channel and sharp angular defect modes by combining two different one-dimensional defective photonic crystals is proposed. The filters designed on the basis of this heterostructure possess both functions of multi-channel narrow band filtering and sharp angular filtering.The channels, channel interval, and number of channels can be tuned by adjusting the geometric and physical parameters of the heterostuctures. This kind of filters will benefit the development of multi-channel interstellar or atmosphere optical communication.

  3. Multichannel Scattering and Loss Processes of Ultracold Atoms in Anisotropic Harmonic Waveguides

    CERN Document Server

    Shadmehri, Sara; Melezhik, Vladimir S

    2016-01-01

    We have developed the general grid method for multi-channel scattering of bosonic atoms inside a harmonic waveguide with transverse anisotropy. This approach is employed to analyze elastic as well as inelastic multi-channel confined scattering. For the elastic scattering, the effects of the range and form of interatomic potential and the waveguide anisotropy on the confinement induced resonance are studied. We have also investigated quantitatively the reactive rate constant in confined atom-atom collisions. It is found that a slight anisotropy to the confining trap considerably enhances the reactive rate constant in multi-channel regime.

  4. Stretchable multichannel antennas in soft wireless optoelectronic implants for optogenetics.

    Science.gov (United States)

    Park, Sung Il; Shin, Gunchul; McCall, Jordan G; Al-Hasani, Ream; Norris, Aaron; Xia, Li; Brenner, Daniel S; Noh, Kyung Nim; Bang, Sang Yun; Bhatti, Dionnet L; Jang, Kyung-In; Kang, Seung-Kyun; Mickle, Aaron D; Dussor, Gregory; Price, Theodore J; Gereau, Robert W; Bruchas, Michael R; Rogers, John A

    2016-12-13

    Optogenetic methods to modulate cells and signaling pathways via targeted expression and activation of light-sensitive proteins have greatly accelerated the process of mapping complex neural circuits and defining their roles in physiological and pathological contexts. Recently demonstrated technologies based on injectable, microscale inorganic light-emitting diodes (μ-ILEDs) with wireless control and power delivery strategies offer important functionality in such experiments, by eliminating the external tethers associated with traditional fiber optic approaches. Existing wireless μ-ILED embodiments allow, however, illumination only at a single targeted region of the brain with a single optical wavelength and over spatial ranges of operation that are constrained by the radio frequency power transmission hardware. Here we report stretchable, multiresonance antennas and battery-free schemes for multichannel wireless operation of independently addressable, multicolor μ-ILEDs with fully implantable, miniaturized platforms. This advance, as demonstrated through in vitro and in vivo studies using thin, mechanically soft systems that separately control as many as three different μ-ILEDs, relies on specially designed stretchable antennas in which parallel capacitive coupling circuits yield several independent, well-separated operating frequencies, as verified through experimental and modeling results. When used in combination with active motion-tracking antenna arrays, these devices enable multichannel optogenetic research on complex behavioral responses in groups of animals over large areas at low levels of radio frequency power (<1 W). Studies of the regions of the brain that are involved in sleep arousal (locus coeruleus) and preference/aversion (nucleus accumbens) demonstrate the unique capabilities of these technologies.

  5. The design of a robotic multichannel platform for photodynamic therapy

    Science.gov (United States)

    Hu, Yida; Finlay, Jarod C.; Zhu, Timothy C.

    2009-06-01

    A compact robotic platform is designed for simultaneous multichannel motion control for light delivery and dosimetry during interstitial photodynamic therapy (PDT). Movements of light sources and isotropic detectors are controlled by individual motors along different catheters for interstitial PDT. The robotic multichannel platform adds feedback control of positioning for up to 16 channels compared to the existing dual-motor system, which did not have positioning encoders. A 16-channel servo motion controller and micro DC motors, each with high resolution optical encoder, are adopted to control the motions of up to 16 channels independently. Each channel has a resolution of 0.1mm and a speed of 5cm/s. The robotic platform can perform light delivery and dosimetry independently, allowing arbitrary positioning of light sources and detectors in each catheter. Up to 16 compact translational channels can be combined according to different operational scheme with real-time optimal motion planning. The characteristic of high speed and coordinating motion will make it possible to use short linear sources (e.g., 1- cm) to deliver uniform PDT treatment to a bulk tumor within reasonable time by source stepping optimization of multiple sources simultaneously. Advanced robotic control algorithm handles the various unexpected circumstance in clinical procedure, e.g., positiontorque/ current control will be applied to prevent excessive force in the case of resistance in the fiber or motorized mechanism. The robotic platform is fully compatible with operation room (OR) environment and improves the light delivery and dosimetry in PDT. It can be adopted for diffusing optical tomography (DOT), spectroscopic DOT and fluorescent spectroscopy.

  6. CR-MAC: A multichannel MAC protocol for cognitive radio ad hoc networks

    CERN Document Server

    Kamruzzaman, S M

    2010-01-01

    This paper proposes a cross-layer based cognitive radio multichannel medium access control (MAC) protocol with TDMA, which integrate the spectrum sensing at physical (PHY) layer and the packet scheduling at MAC layer, for the ad hoc wireless networks. The IEEE 802.11 standard allows for the use of multiple channels available at the PHY layer, but its MAC protocol is designed only for a single channel. A single channel MAC protocol does not work well in a multichannel environment, because of the multichannel hidden terminal problem. Our proposed protocol enables secondary users (SUs) to utilize multiple channels by switching channels dynamically, thus increasing network throughput. In our proposed protocol, each SU is equipped with only one spectrum agile transceiver, but solves the multichannel hidden terminal problem using temporal synchronization. The proposed cognitive radio MAC (CR-MAC) protocol allows SUs to identify and use the unused frequency spectrum in a way that constrains the level of interference...

  7. Spatial interpolation of HRTFs and signal mixing for multichannel surround sound

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun

    2006-01-01

    From the point of spatial sampling, spatial interpolation of HRTFs (head-related transfer functions) and signal mixing for multichannel (surround) sound are analyzed. First, it is proved that they are mathematically equivalent. Different methods for HRTFs interpolation are equivalent to different signal mixing methods for multichannel sound. Then, a stricter derivation for the signal mixing of multichannel sound and the law of sine for stereophonic sound is given. It is pointed out that trying to reconstruct lateral HRTFs by adjacent linear interpolation is wrong. And for accurate sound image localization, the conventional equation of adjacent linear interpolation of HRTFs is revised. At last, it is also pointed out that some methods used in the analysis of HRTFs and multichannel sound can be used for reference mutually.

  8. Multichannel Seismic Reflection Data - SCAR - Prydz Bay - 1984-1985, SDLS CD-ROM vol 21

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1984-85 in the Prydz Bay region, Antarctica, by the Japan National Oil...

  9. Multichannel Seismic Reflection Data - SCAR - Wilkes Land 1982, SDLS CD-ROM vol 11

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from sixteen lines recorded during 1982 off Wilkes Island, Antarctica, by the Institut Francais du...

  10. Multichannel Seismic Reflection Data, SCAR - Wilkes Land 1982, SDLS, CD-ROM 15

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from thirteen lines recorded during 1983 off Wilkes Island, Antarctica, by the U.S. Geological...

  11. Solving non-Markovian open quantum systems with multi-channel reservoir coupling

    CERN Document Server

    Broadbent, Curtis J; Yu, Ting; Eberly, Joseph H

    2011-01-01

    We extend the non-Markovian quantum state diffusion (QSD) equation to open quantum systems which exhibit multi-channel coupling to a harmonic oscillator reservoir. Open quantum systems which have multi-channel reservoir coupling are those in which canonical transformation of reservoir modes cannot reduce the number of reservoir operators appearing in the interaction Hamiltonian to one. We show that the non-Markovian QSD equation for multi-channel reservoir coupling can, in some cases, lead to an exact master equation which we derive. We then derive the exact master equation for the three-level system in a vee-type configuration which has multi-channel reservoir coupling and give the analytical solution. Finally, we examine the evolution of the three-level vee-type system with generalized Ornstein-Uhlenbeck reservoir correlations numerically.

  12. Solving non-Markovian open quantum systems with multi-channel reservoir coupling

    Science.gov (United States)

    Broadbent, Curtis J.; Jing, Jun; Yu, Ting; Eberly, Joseph H.

    2012-08-01

    We extend the non-Markovian quantum state diffusion (QSD) equation to open quantum systems which exhibit multi-channel coupling to a harmonic oscillator reservoir. Open quantum systems which have multi-channel reservoir coupling are those in which canonical transformation of reservoir modes cannot reduce the number of reservoir operators appearing in the interaction Hamiltonian to one. We show that the non-Markovian QSD equation for multi-channel reservoir coupling can, in some cases, lead to an exact master equation which we derive. We then derive the exact master equation for the three-level system in a vee-type configuration which has multi-channel reservoir coupling and give the analytical solution. Finally, we examine the evolution of the three-level vee-type system with generalized Ornstein-Uhlenbeck reservoir correlations numerically.

  13. Novel method for removal of multichannel impulse noise based on half-space deepest location

    Science.gov (United States)

    Baljozović, Djordje; Kovačević, Branko; Baljozović, Aleksandra

    2012-01-01

    A novel method is proposed for removing impulse (random-valued and salt-and-pepper) noise from multichannel digital images based on an adapted version of the DEEPLOC algorithm introduced by A. Struyf and P. J. Rousseeuw for calculation of approximate half-space (Tukey's) deepest location (median) in multivariate case. Due to its intrinsic multivariate/multidimensional nature, the proposed method eliminates the noise simultaneously on all channels without their separation, which preserves the spectral correlation between channels in a multichannel image. Denoising results of this new nonlinear spatial domain filter applied to benchmark images outperform currently used state-of-the-art filters for impulse noise removal from multichannel images in terms of both objective effectiveness criteria [peak-signal-to-noise-ratio (PSNR), mean absolute error (MAE), and normalized color distance (NCD)] and visual quality. The proposed filter successfully preserves the edges and fine image details, and is very effective for removal of medium and heavy multichannel impulse noise.

  14. Numerical analysis of four-wave-mixing based multichannel wavelength conversion techniques in fibers

    Institute of Scientific and Technical Information of China (English)

    Jia Liang; Zhang Fan; Li Ming; Liu Yuliang; Chen Zhangyuan

    2009-01-01

    We numerically investigate four-wave-mixing (FWM) based multichannel wavelength conversion for amplitude-modulated signals, phase-modulated signals, together with mixed amplitude and phase modulated signals. This paper also discusses the influence of stimulated Brillouin scattering (SBS) effects on high-efficiency FWM-based wavelength conversion applications. Our simulation results show that DPSK signals are more suitable for FWM-based multichannel wavelength conversion because the OOK signals will suffer from the inevitable datapattern-dependent pump depletion. In future applications, when the modulation format is partially upgraded from OOK to DPSK, the influence of OOK signals on the updated DPSK signals must be considered when using multichannel wavelength conversion. This influence becomes severe with the increase of OOK channel number. It can be concluded that DPSK signals are more appropriate for both transmission and multichannel wavelength conversion,especially in long haul and high bit-rate system.

  15. Advanced Modular, Multi-Channel, High Speed Fiber Optic Sensing System for Acoustic Emissions Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes to prove the feasibility of innovations based on ultra-light-weight, ultra-high-speed, multi-channel,...

  16. Multichannel Seismic Reflection Data - SCAR - Antarctic Peninsula 1987-88, SDLS CD-ROM vol 24

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1987-88 in the Antarctic Peninsula, Antarctica, by the Japan National Oil...

  17. 3D Multi-Channel Networked Visualization System for National LambdaRail Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multichannel virtual reality visualization is the future of complex simulation with a large number of visual channels rendered and transmitted over high-speed...

  18. Multichannel Seismic Reflection - SCAR- Prydz Bay 1980 SDLS CD-ROM vol 8

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1980 in the Prydz Bay region, by Australian Geological Survey Organization. The...

  19. Multichannel Seismic Reflection Data - SCAR - Wilkes Land, 1983, SDLS CD-ROM vol 10

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from thirteen lines recorded during 1983 off Wilkes Island, Antarctica, by the Japan National Oil...

  20. Multichannel Seismic Reflection - SCAR- Antarctic Penn. 1987-88 SDLS CD-ROM vol 26

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1987-88 in the Antarctica Peninsula region, by Petrobras, Brazil. The following...

  1. Multichannel Seismic Reflection Data - SCAR - Antarctic Peninsula - 1988-1989, SDLS CD-ROM vol 25

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1988-89 in the Antarctic Peninsula, Antarctica, by the Japan National Oil...

  2. Multichannel Seismic Reflection - SCAR- Antarctic Penn. 1987-88 SDLS CD-ROM vol 27

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1987-88 in the Antarctica Peninsula region, by Petrobras, Brazil. The following...

  3. Multichannel Seismic Reflection Data - SCAR - Antarctic Peninsula - 1985, SDLS CD-ROM vol 16

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1985 field season along the north side of the Antarctic-Peninsula by the British...

  4. The Performance of Reflecting Multichannel Collimators as a Neutron Beam Filter and Polarizer

    DEFF Research Database (Denmark)

    Bjerrum Møller, Hans; Passell, L.; Stecher-Rasmussen, F.

    1963-01-01

    Summarizes the results obtained to date from a study of the properties of reflecting multi-channel collimators. The measurements have not yet been completed but enough information is available to give an indication of the capabilities of the system....

  5. A Novel Multi-Channel Dispersion Slope Compensator Using Sampled FBG

    Institute of Scientific and Technical Information of China (English)

    J.; J.; Pan; Claire; Gu; Albert; Li

    2003-01-01

    A novel dispersion slope compensator is proposed and fabricated using a sampled fiber grating. The dispersion slope of this compensator is demonstrated to match that of Coming LS fiber for a multi-channel 50GHz WDM system.

  6. Optical Multichannel Imaging of Pulsed Laser Deposition of ZnO (PostPrint)

    Science.gov (United States)

    2014-08-01

    AFRL-RX-WP-JA-2014-0186 OPTICAL MULTICHANNEL IMAGING OF PULSED LASER DEPOSITION OF ZNO (POSTPRINT) John G. Jones AFRL/RXAN...PULSED LASER DEPOSITION OF ZNO (POSTPRINT) 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR(S...Optical Multichannel Imaging of Pulsed Laser Deposition of ZnO John G. Jones, Lirong Sun, Neil R. Murphy, and Rachel Jakubiak Abstract— Pulsed laser

  7. Single versus multichannel applicator in high-dose-rate vaginal brachytherapy optimized by inverse treatment planning.

    Science.gov (United States)

    Bahadur, Yasir A; Constantinescu, Camelia; Hassouna, Ashraf H; Eltaher, Maha M; Ghassal, Noor M; Awad, Nesreen A

    2015-01-01

    To retrospectively compare the potential dosimetric advantages of a multichannel vaginal applicator vs. a single channel one in intracavitary vaginal high-dose-rate (HDR) brachytherapy after hysterectomy, and evaluate the dosimetric advantage of fractional re-planning. We randomly selected 12 patients with endometrial carcinoma, who received adjuvant vaginal cuff HDR brachytherapy using a multichannel applicator. For each brachytherapy fraction, two inverse treatment plans (for central channel and multichannel loadings) were performed and compared. The advantage of fractional re-planning was also investigated. Dose-volume-histogram (DVH) analysis showed limited, but statistically significant difference (p = 0.007) regarding clinical-target-volume dose coverage between single and multichannel approaches. For the organs-at-risk rectum and bladder, the use of multichannel applicator demonstrated a noticeable dose reduction, when compared to single channel, but statistically significant for rectum only (p = 0.0001). For D2cc of rectum, an average fractional dose of 6.1 ± 0.7 Gy resulted for single channel vs. 5.1 ± 0.6 Gy for multichannel. For D2cc of bladder, an average fractional dose of 5 ± 0.9 Gy occurred for single channel vs. 4.9 ± 0.8 Gy for multichannel. The dosimetric benefit of fractional re-planning was demonstrated: DVH analysis showed large, but not statistically significant differences between first fraction plan and fractional re-planning, due to large inter-fraction variations for rectum and bladder positioning and filling. Vaginal HDR brachytherapy using a multichannel vaginal applicator and inverse planning provides dosimetric advantages over single channel cylinder, by reducing the dose to organs at risk without compromising the target volume coverage, but at the expense of an increased vaginal mucosa dose. Due to large inter-fraction dose variations, we recommend individual fraction treatment plan optimization.

  8. Multichannel biomedical time series clustering via hierarchical probabilistic latent semantic analysis.

    Science.gov (United States)

    Wang, Jin; Sun, Xiangping; Nahavandi, Saeid; Kouzani, Abbas; Wu, Yuchuan; She, Mary

    2014-11-01

    Biomedical time series clustering that automatically groups a collection of time series according to their internal similarity is of importance for medical record management and inspection such as bio-signals archiving and retrieval. In this paper, a novel framework that automatically groups a set of unlabelled multichannel biomedical time series according to their internal structural similarity is proposed. Specifically, we treat a multichannel biomedical time series as a document and extract local segments from the time series as words. We extend a topic model, i.e., the Hierarchical probabilistic Latent Semantic Analysis (H-pLSA), which was originally developed for visual motion analysis to cluster a set of unlabelled multichannel time series. The H-pLSA models each channel of the multichannel time series using a local pLSA in the first layer. The topics learned in the local pLSA are then fed to a global pLSA in the second layer to discover the categories of multichannel time series. Experiments on a dataset extracted from multichannel Electrocardiography (ECG) signals demonstrate that the proposed method performs better than previous state-of-the-art approaches and is relatively robust to the variations of parameters including length of local segments and dictionary size. Although the experimental evaluation used the multichannel ECG signals in a biometric scenario, the proposed algorithm is a universal framework for multichannel biomedical time series clustering according to their structural similarity, which has many applications in biomedical time series management. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Consideration of conditions required for multi-channel simultaneous bioimpedance measurement

    OpenAIRE

    1998-01-01

    Impedance techniques have been widely applied to the biomedical engineering field. In order to obtain definite results from bioimpedance, multi-channel measurement is effective. A linearity of biological tissue and fundamental technical parameters for the instrument must be confirmed. In this study, the fundamental conditions have been investigated for multi-channel bioimpedance measurement and the condition of measurement for biological tissue has been confirmed. The differences of every mea...

  10. EDMC: An enhanced distributed multi-channel anti-collision algorithm for RFID reader system

    Science.gov (United States)

    Zhang, YuJing; Cui, Yinghua

    2017-05-01

    In this paper, we proposes an enhanced distributed multi-channel reader anti-collision algorithm for RFID environments which is based on the distributed multi-channel reader anti-collision algorithm for RFID environments (called DiMCA). We proposes a monitor method to decide whether reader receive the latest control news after it selected the data channel. The simulation result shows that it improves interrogation delay.

  11. Solving non-Markovian open quantum systems with multi-channel reservoir coupling

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, Curtis J., E-mail: curtis.broadbent@rochester.edu [Rochester Theory Center, and Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Jing, Jun; Yu, Ting [Center for Controlled Quantum Systems, and the Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Eberly, Joseph H. [Rochester Theory Center, and Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2012-08-15

    We extend the non-Markovian quantum state diffusion (QSD) equation to open quantum systems which exhibit multi-channel coupling to a harmonic oscillator reservoir. Open quantum systems which have multi-channel reservoir coupling are those in which canonical transformation of reservoir modes cannot reduce the number of reservoir operators appearing in the interaction Hamiltonian to one. We show that the non-Markovian QSD equation for multi-channel reservoir coupling can, in some cases, lead to an exact master equation which we derive. We then derive the exact master equation for the three-level system in a vee-type configuration which has multi-channel reservoir coupling and give the analytical solution. Finally, we examine the evolution of the three-level vee-type system with generalized Ornstein-Uhlenbeck reservoir correlations numerically. - Highlights: Black-Right-Pointing-Pointer The concept of multi-channel vs. single-channel reservoir coupling is rigorously defined. Black-Right-Pointing-Pointer The non-Markovian quantum state diffusion equation for arbitrary multi-channel reservoir coupling is derived. Black-Right-Pointing-Pointer An exact time-local master equation is derived under certain conditions. Black-Right-Pointing-Pointer The analytical solution to the three-level system in a vee-type configuration is found. Black-Right-Pointing-Pointer The evolution of the three-level system under generalized Ornstein-Uhlenbeck noise is plotted for many parameter regimes.

  12. Adaptive Multichannel Radiation Sensors for Plant Parameter Monitoring

    Science.gov (United States)

    Mollenhauer, Hannes; Remmler, Paul; Schuhmann, Gudrun; Lausch, Angela; Merbach, Ines; Assing, Martin; Mollenhauer, Olaf; Dietrich, Peter; Bumberger, Jan

    2016-04-01

    Nutrients such as nitrogen are playing a key role in the plant life cycle. They are much needed for chlorophyll production and other plant cell components. Therefore, the crop yield is strongly affected by plant nutrient status. Due to the spatial and temporal variability of soil characteristics or swaying agricultural inputs the plant development varies within a field. Thus, the determination of these fluctuations in the plant development is valuable for a detection of stress conditions and optimization of fertilisation due to its high environmental and economic impact. Plant parameters play crucial roles in plant growth estimation and prediction since they are used as indicators of plant performance. Especially indices derived out of remote sensing techniques provide quantitative information about agricultural crops instantaneously, and above all, non-destructively. Due to the specific absorption of certain plant pigments, a characteristic spectral signature can be seen in the visible and IR part of the electromagnetic spectrum, known as narrow-band peaks. In an analogous manner, the presence and concentration of different nutrients cause a characteristic spectral signature. To this end, an adequate remote sensing monitoring concept is needed, considering heterogeneity and dynamic of the plant population and economical aspects. This work will present the development and field investigations of an inexpensive multichannel radiation sensor to observe the incoming and reflected specific parts or rather distinct wavelengths of the solar light spectrum on the crop and facilitate the determination of different plant indices. Based on the selected sensor wavelengths, the sensing device allows the detection of specific parameters, e.g. plant vitality, chlorophyll content or nitrogen content. Besides the improvement of the sensor characteristic, the simple wavelength adaption, and the price-performance ratio, the achievement of appropriate energy efficiency as well as a

  13. Multichannel analysis of surface wave method with the autojuggie

    Science.gov (United States)

    Tian, G.; Steeples, D.W.; Xia, J.; Miller, R.D.; Spikes, K.T.; Ralston, M.D.

    2003-01-01

    The shear (S)-wave velocity of near-surface materials and its effect on seismic-wave propagation are of fundamental interest in many engineering, environmental, and groundwater studies. The multichannel analysis of surface wave (MASW) method provides a robust, efficient, and accurate tool to observe near-surface S-wave velocity. A recently developed device used to place large numbers of closely spaced geophones simultaneously and automatically (the 'autojuggie') is shown here to be applicable to the collection of MASW data. In order to demonstrate the use of the autojuggie in the MASW method, we compared high-frequency surface-wave data acquired from conventionally planted geophones (control line) to data collected in parallel with the automatically planted geophones attached to steel bars (test line). The results demonstrate that the autojuggie can be applied in the MASW method. Implementation of the autojuggie in very shallow MASW surveys could drastically reduce the time required and costs incurred in such surveys. ?? 2003 Elsevier Science Ltd. All rights reserved.

  14. Total ozone retrieval from satellite multichannel filter radiometer measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lovill, J.E.; Sullivan, T.J.; Weichel, R.L.; Ellis, J.S.; Huebel, J.G.; Korver, J.; Weidhaas, P.P.; Phelps, F.A.

    1978-05-25

    A total ozone retrieval model has been developed to process radiance data gathered by a satellite-mounted multichannel filter radiometer (MFR). Extensive effort went into theoretical radiative transfer modeling, a retrieval scheme was developed, and the technique was applied to the MFR radiance measurements. The high quality of the total ozone retrieval results was determined through comparisons with Dobson measurements. Included in the report are global total ozone maps for 20 days between May 12 and July 5, 1977. A comparison of MFR results for 13 days in June 1977 with Dobson spectrophotometer measurements of ozone for the same period showed good agreement: there was a root-mean-square difference of 6.2% (equivalent to 20.2 m.atm.cm). The estimated global total ozone value for June 1977 (296 m.atm.cm) was in good agreement with satellite backscatter ultraviolet data for June 1970 (304 m.atm.cm) and June 1971 (preliminary data--299 m.atm.cm).

  15. High transformer ratio of multi-channel dielectric wakefield structures

    Science.gov (United States)

    Shchelkunov, Sergey V.; Marshall, Thomas C.; Sotnikov, Gennadij V.; Hirshfield, Jay L.

    2016-09-01

    Dielectric wakefield (DWA) accelerator concepts are receiving attention on account of their promising performance, mechanical simplicity, and anticipated low cost. Interest in DWA physics directed toward an advanced high-gradient accelerator has been enhanced by a finding that some dielectrics can withstand very high fields (>1 GV/m) for the short times during the passage of charged bunches along dielectric-lined channels. In a two-channel structure, a drive bunch train propagates in a first channel, and in the second adjacent channel where a high gradient wakefield develops, a witness bunch is accelerated. Compared with single-channel DWA's, a two-beam accelerator delivers a high transformer ratio, and thereby reduces the number of drive beam sections needed to achieve a given final test beam energy. An overview of multi-channel DWA structures will be given, with an emphasis on two-channel structures, presenting their advantages and drawbacks, and potential impact on the field. Studies aimed to examine charging rate and charge distribution in a thin walled dielectric wakefield accelerator from a passing charge bunch and the physics of conductivity and discharge phenomena in dielectric materials useful for such accelerator applications are presented in a separate paper in the EAAC-2015 conference proceedings.

  16. High transformer ratio of multi-channel dielectric wakefield structures

    Energy Technology Data Exchange (ETDEWEB)

    Shchelkunov, Sergey V., E-mail: sergey.shchelkunov@gmail.com [Omega-P R& D, Inc, CT 06511 (United States); Yale University, CT (United States); Marshall, Thomas C. [Omega-P R& D, Inc, CT 06511 (United States); Sotnikov, Gennadij V. [NSC Kharkov Institute of Physics and Technology, Kharkov (Ukraine); Hirshfield, Jay L. [Omega-P R& D, Inc, CT 06511 (United States)

    2016-09-01

    Dielectric wakefield (DWA) accelerator concepts are receiving attention on account of their promising performance, mechanical simplicity, and anticipated low cost. Interest in DWA physics directed toward an advanced high-gradient accelerator has been enhanced by a finding that some dielectrics can withstand very high fields (>1 GV/m) for the short times during the passage of charged bunches along dielectric-lined channels. In a two-channel structure, a drive bunch train propagates in a first channel, and in the second adjacent channel where a high gradient wakefield develops, a witness bunch is accelerated. Compared with single-channel DWA's, a two-beam accelerator delivers a high transformer ratio, and thereby reduces the number of drive beam sections needed to achieve a given final test beam energy. An overview of multi-channel DWA structures will be given, with an emphasis on two-channel structures, presenting their advantages and drawbacks, and potential impact on the field. Studies aimed to examine charging rate and charge distribution in a thin walled dielectric wakefield accelerator from a passing charge bunch and the physics of conductivity and discharge phenomena in dielectric materials useful for such accelerator applications are presented in a separate paper in the EAAC-2015 conference proceedings.

  17. Mimicking multichannel scattering with single-channel approaches

    Science.gov (United States)

    Grishkevich, Sergey; Schneider, Philipp-Immanuel; Vanne, Yulian V.; Saenz, Alejandro

    2010-02-01

    The collision of two atoms is an intrinsic multichannel (MC) problem, as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold Li6 and Rb87 atoms in the ground state and in the presence of a static magnetic field B. The obtained MC solutions are used to test various existing as well as presently developed SC approaches. It was found that many aspects even at short internuclear distances are qualitatively well reflected. This can be used to investigate molecular processes in the presence of an external trap or in many-body systems that can be feasibly treated only within the framework of the SC approximation. The applicability of various SC approximations is tested for a transition to the absolute vibrational ground state around an MFR. The conformance of the SC approaches is explained by the two-channel approximation for the MFR.

  18. Upper-limb prosthetic control using wearable multichannel mechanomyography.

    Science.gov (United States)

    Wilson, Samuel; Vaidyanathan, Ravi

    2017-07-01

    In this paper we introduce a robust multi-channel wearable sensor system for capturing user intent to control robotic hands. The interface is based on a fusion of inertial measurement and mechanomyography (MMG), which measures the vibrations of muscle fibres during motion. MMG is immune to issues such as sweat, skin impedance, and the need for a reference signal that is common to electromyography (EMG). The main contributions of this work are: 1) the hardware design of a fused inertial and MMG measurement system that can be worn on the arm, 2) a unified algorithm for detection, segmentation, and classification of muscle movement corresponding to hand gestures, and 3) experiments demonstrating the real-time control of a commercial prosthetic hand (Bebionic Version 2). Results show recognition of seven gestures, achieving an offline classification accuracy of 83.5% performed on five healthy subjects and one transradial amputee. The gesture recognition was then tested in real time on subsets of two and five gestures, with an average accuracy of 93.3% and 62.2% respectively. To our knowledge this is the first applied MMG based control system for practical prosthetic control.

  19. Multichannel Convolutional Neural Network for Biological Relation Extraction

    Science.gov (United States)

    Quan, Chanqin; Sun, Xiao; Bai, Wenjun

    2016-01-01

    The plethora of biomedical relations which are embedded in medical logs (records) demands researchers' attention. Previous theoretical and practical focuses were restricted on traditional machine learning techniques. However, these methods are susceptible to the issues of “vocabulary gap” and data sparseness and the unattainable automation process in feature extraction. To address aforementioned issues, in this work, we propose a multichannel convolutional neural network (MCCNN) for automated biomedical relation extraction. The proposed model has the following two contributions: (1) it enables the fusion of multiple (e.g., five) versions in word embeddings; (2) the need for manual feature engineering can be obviated by automated feature learning with convolutional neural network (CNN). We evaluated our model on two biomedical relation extraction tasks: drug-drug interaction (DDI) extraction and protein-protein interaction (PPI) extraction. For DDI task, our system achieved an overall f-score of 70.2% compared to the standard linear SVM based system (e.g., 67.0%) on DDIExtraction 2013 challenge dataset. And for PPI task, we evaluated our system on Aimed and BioInfer PPI corpus; our system exceeded the state-of-art ensemble SVM system by 2.7% and 5.6% on f-scores. PMID:28053977

  20. Fast Adaptive Blind MMSE Equalizer for Multichannel FIR Systems

    Directory of Open Access Journals (Sweden)

    Abed-Meraim Karim

    2006-01-01

    Full Text Available We propose a new blind minimum mean square error (MMSE equalization algorithm of noisy multichannel finite impulse response (FIR systems, that relies only on second-order statistics. The proposed algorithm offers two important advantages: a low computational complexity and a relative robustness against channel order overestimation errors. Exploiting the fact that the columns of the equalizer matrix filter belong both to the signal subspace and to the kernel of truncated data covariance matrix, the proposed algorithm achieves blindly a direct estimation of the zero-delay MMSE equalizer parameters. We develop a two-step procedure to further improve the performance gain and control the equalization delay. An efficient fast adaptive implementation of our equalizer, based on the projection approximation and the shift invariance property of temporal data covariance matrix, is proposed for reducing the computational complexity from to , where is the number of emitted signals, the data vector length, and the dimension of the signal subspace. We then derive a statistical performance analysis to compare the equalization performance with that of the optimal MMSE equalizer. Finally, simulation results are provided to illustrate the effectiveness of the proposed blind equalization algorithm.

  1. Design of 3D Active Multichannel Silicon Neural Microelectrode

    Institute of Scientific and Technical Information of China (English)

    WANG Di; ZHANG Guoxiong; LI Xingfei

    2006-01-01

    To find a design method for 3D active multichannel silicon microelectrode,a microstructure of active neural recording system is presented,where two 2D probes,two integrated circuits and two spacers are microassembled on a 5 mm ×7 mm silicon platform,and 32 sites neural signals can be operated simultaneously.A theoretical model for measuring the neural signal by the silicon microelectrode is proposed based on the structure and fabrication process of a single-shank probe.The method of determining the dimensional parameters of the probe shank is discussed in the following three aspects,i.e.the structures of pallium and endocranium,coupled interconnecters noise,and strength characteristic of neural probe.The design criterion is to minimize the size of the neural probe as well as that the probe has enough stiffness to pierce the endocranium.The on-chip unity-gain bandpass amplifier has an overall gain of 42 dB over a bandwidth from 60 Hz to 10 kHz;and the DC-baseline stability circuit is of high input resistance above 30 MΩ to guarantee a cutoff frequency below 100 Hz.The circuit works in stimulating or recording modes.The conversion of the modes depends on the stimulating control signal.

  2. Mathematical Model of the Multi-Channel Spiral Cyclone

    Directory of Open Access Journals (Sweden)

    Justina Danilenkaitė

    2013-12-01

    Full Text Available The article deals with a problem of experimental investigation and numerical simulation of gas aerodynamics of a multi-channel spiral cyclone with a tangential inlet. The paper presents an overview of experimental and theoretical works on the cyclones having a particularly complex turbulent flow and focuses on three-dimensional transport differential equations for a non-compressible laminar and turbulent flow inside the cyclone. The equations have been solved applying the numerical finite volume method using the RNG (Re–Normalisation Group k-ε turbulence model. The numerical simulation of the flow cyclone has been carried out. The height of the cyclone is 0.80 m with 0.33 m in diameter, the height of the spiral–cylindrical part – 0.098 meters and that of the cone – 0.45 m. Inlet dimensions (cylindrical part on the side, in accordance with drawings makes a×b = 28×95 mm. The mathematical model for the air traffic movement cyclone has accounted for Navier-Stokes (Reynolds three-dimensional differential equations. The simulation results have been obtained with reference to the cyclone of tangential velocity profiles using RNG k-ε turbulence model. The inlet velocity of 5.1 m/s slightly differs from experimental results, thus making an error of 7%.Article in Lithuanian

  3. Fourier-domain multichannel autofocus for synthetic aperture radar.

    Science.gov (United States)

    Liu, Kuang-Hung; Munson, David C

    2011-12-01

    Synthetic aperture radar (SAR) imaging suffers from image focus degradation in the presence of phase errors in the received signal due to unknown platform motion or signal propagation delays. We present a new autofocus algorithm, termed Fourier-domain multichannel autofocus (FMCA), that is derived under a linear algebraic framework, allowing the SAR image to be focused in a noniterative fashion. Motivated by the mutichannel autofocus (MCA) approach, the proposed autofocus algorithm invokes the assumption of a low-return region, which generally is provided within the antenna sidelobes. Unlike MCA, FMCA works with the collected polar Fourier data directly and is capable of accommodating wide-angle monostatic SAR and bistatic SAR scenarios. Most previous SAR autofocus algorithms rely on the prior assumption that radar's range of look angles is small so that the phase errors can be modeled as varying along only one dimension in the collected Fourier data. And, in some cases, implicit assumptions are made regarding the SAR scene. Performance of such autofocus algorithms degrades if the assumptions are not satisfied. The proposed algorithm has the advantage that it does not require prior assumptions about the range of look angles, nor characteristics of the scene.

  4. Score-Informed Source Separation for Multichannel Orchestral Recordings

    Directory of Open Access Journals (Sweden)

    Marius Miron

    2016-01-01

    Full Text Available This paper proposes a system for score-informed audio source separation for multichannel orchestral recordings. The orchestral music repertoire relies on the existence of scores. Thus, a reliable separation requires a good alignment of the score with the audio of the performance. To that extent, automatic score alignment methods are reliable when allowing a tolerance window around the actual onset and offset. Moreover, several factors increase the difficulty of our task: a high reverberant image, large ensembles having rich polyphony, and a large variety of instruments recorded within a distant-microphone setup. To solve these problems, we design context-specific methods such as the refinement of score-following output in order to obtain a more precise alignment. Moreover, we extend a close-microphone separation framework to deal with the distant-microphone orchestral recordings. Then, we propose the first open evaluation dataset in this musical context, including annotations of the notes played by multiple instruments from an orchestral ensemble. The evaluation aims at analyzing the interactions of important parts of the separation framework on the quality of separation. Results show that we are able to align the original score with the audio of the performance and separate the sources corresponding to the instrument sections.

  5. Multichannel waveguides for the simultaneous detection of disease biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Harshini [Los Alamos National Laboratory; Price, Dominique Z [Los Alamos National Laboratory; Grace, Wynne K [Los Alamos National Laboratory; Swanson, Basil I [Los Alamos National Laboratory

    2009-01-01

    The sensor team at the Los Alamos National Laboratory has developed a waveguide-based optical biosensor that has previously been used for the detection of biomarkers associated with diseases such as tuberculosis, breast cancer, anthrax and influenza in complex biological samples (e.g., serum and urine). However, no single biomarker can accurately predict disease. To address this issue, we developed a multiplex assay for the detection of components of the Bacillus anthracis lethal toxin on single mode planar optical waveguides with tunable quantum dots as the fluorescence reporter. This limited ability to multiplex is still insufficient for accurate detection of disease or for monitoring prognosis. In this manuscript, we demonstrate for the first time, the design, fabrication and successful evaluation of a multichannel planar optical waveguide for the simultaneous detection of at least three unknown samples in quadruplicate. We demonstrate the simultaneous, rapid (30 min), quantitative (with internal standard) and sensitive (limit of detection of 1 pM) detection of protective antigen and lethal factor of Bacillus anthracis in complex biological samples (serum) using specific monoclonal antibodies labeled with quantum dots as the fluorescence reporter.

  6. A robotic multi-channel platform for interstitial photodynamic therapy

    Science.gov (United States)

    Sharikova, Anna V.; Finlay, Jarod C.; Dimofte, Andreea; Zhu, Timothy C.

    2013-03-01

    A custom-made robotic multichannel platform for interstitial photodynamic therapy (PDT) and diffuse optical tomography (DOT) was developed and tested in a phantom experiment. The system, which was compatible with the operating room (OR) environment, had 16 channels for independent positioning of light sources and/or isotropic detectors in separate catheters. Each channel's motor had an optical encoder for position feedback, with resolution of 0.05 mm, and a maximum speed of 5 cm/s. Automatic calibration of detector positions was implemented using an optical diode beam that defined the starting position of each motor, and by means of feedback algorithms controlling individual channels. As a result, the accuracy of zero position of 0.1 mm for all channels was achieved. We have also employed scanning procedures where detectors automatically covered the appropriate range around source positions. Thus, total scan time for a typical optical properties (OP) measurement throughout the phantom was about 1.5 minutes with point sources. The OP were determined based on the measured light fluence rates. These enhancements allow a tremendous improvement of treatment quality for a bulk tumor compared to the systems employed in previous clinical trials.

  7. Multi-Channel Transfer Function with Dimensionality Reduction

    Science.gov (United States)

    Kim, Han Suk; Schulze, Jürgen P.; Cone, Angela C.; Sosinsky, Gina E.; Martone, Maryann E.

    2010-01-01

    The design of transfer functions for volume rendering is a difficult task. This is particularly true for multi-channel data sets, where multiple data values exist for each voxel. In this paper, we propose a new method for transfer function design. Our new method provides a framework to combine multiple approaches and pushes the boundary of gradient-based transfer functions to multiple channels, while still keeping the dimensionality of transfer functions to a manageable level, i.e., a maximum of three dimensions, which can be displayed visually in a straightforward way. Our approach utilizes channel intensity, gradient, curvature and texture properties of each voxel. The high-dimensional data of the domain is reduced by applying recently developed nonlinear dimensionality reduction algorithms. In this paper, we used Isomap as well as a traditional algorithm, Principle Component Analysis (PCA). Our results show that these dimensionality reduction algorithms significantly improve the transfer function design process without compromising visualization accuracy. In this publication we report on the impact of the dimensionality reduction algorithms on transfer function design for confocal microscopy data. PMID:20582228

  8. Automated measurement of urinary creatinine by multichannel kinetic spectrophotometry.

    Science.gov (United States)

    Ohira, Shin-Ichi; Kirk, Andrea B; Dasgupta, Purnendu K

    2009-01-15

    Urinary creatinine analysis is required for clinical diagnosis, especially for evaluation of renal function. Creatinine adjustment is also widely used to estimate 24-h excretion from spot samples. Few convenient validated approaches are available for in-house creatinine measurement for small- to medium-scale studies. Here we apply the Jáffe reaction to creatinine determination with zone fluidic multichannel kinetic spectrophotometry. Diluted urine sample and reagent, alkaline picric acid, were mixed by a computer-programmed dispenser and rapidly delivered to a four-channel detection cell. The absorbance change was monitored by a flow-through light-emitting diode-photodiode-based detector. Validation results against high-performance liquid chromatography-ultraviolet (HPLC-UV)/mass spectrometry (MS) are presented. Responses for 10-fold diluted samples were linear within clinically relevant ranges (0-250 mg/L after dilution). The system can analyze 70 samples per hour with a limit of detection of 0.76 mg/L. The relative standard deviation was 1.29% at 100 mg/L creatinine (n=225). Correlation with the HPLC (UV quantitation/MS confirmation) system was excellent (linear, r2=0.9906). The developed system allows rapid, simple, cost-effective, and robust creatinine analysis and is suitable for the analysis of large numbers of urine samples.

  9. A research of a high precision multichannel data acquisition system

    Science.gov (United States)

    Zhong, Ling-na; Tang, Xiao-ping; Yan, Wei

    2013-08-01

    The output signals of the focusing system in lithography are analog. To convert the analog signals into digital ones which are more flexible and stable to process, a desirable data acquisition system is required. The resolution of data acquisition, to some extent, affects the accuracy of focusing. In this article, we first compared performance between the various kinds of analog-to-digital converters (ADC) available on the market at the moment. Combined with the specific requirements (sampling frequency, converting accuracy, numbers of channels etc) and the characteristics (polarization, amplitude range etc) of the analog signals, the model of the ADC to be used as the core chip in our hardware design was determined. On this basis, we chose other chips needed in the hardware circuit that would well match with ADC, then the overall hardware design was obtained. Validation of our data acquisition system was verified through experiments and it can be demonstrated that the system can effectively realize the high resolution conversion of the multi-channel analog signals and give the accurate focusing information in lithography.

  10. Multichannel Dynamic-Range Compression Using Digital Frequency Warping

    Directory of Open Access Journals (Sweden)

    Kathryn Hoberg Arehart

    2005-11-01

    Full Text Available A multichannel dynamic-range compressor system using digital frequency warping is described. A frequency-warped filter is realized by replacing the filter unit delays with all-pass filters. The appropriate design of the frequency warping gives a nonuniform frequency representation very close to the auditory Bark scale. The warped compressor is shown to have substantially reduced group delay in comparison with a conventional design having comparable frequency resolution. The warped compressor, however, has more delay at low than at high frequencies, which can lead to perceptible changes in the signal. The detection threshold for the compressor group delay was determined as a function of the number of all-pass filter sections in cascade needed for a detectible change in signal quality. The test signals included clicks, vowels, and speech, and results are presented for both normal-hearing and hearing-impaired subjects. Thresholds for clicks are lower than thresholds for vowels, and hearing-impaired subjects have higher thresholds than normal-hearing listeners. A frequency-warped compressor using a cascade of 31 all-pass filter sections offers a combination of low overall delay, good frequency resolution, and imperceptible frequency-dependent delay effects for most listening conditions.

  11. Single particle multichannel bio-aerosol fluorescence sensor.

    Science.gov (United States)

    Kaye, P; Stanley, W R; Hirst, E; Foot, E V; Baxter, K L; Barrington, S J

    2005-05-16

    We describe a prototype low-cost multi-channel aerosol fluorescence sensor designed for unattended deployment in medium to large area bio-aerosol detection networks. Individual airborne particles down to ~1mum in size are detected and sized by measurement of light scattered from a continuous-wave diode laser (660nm). This scatter signal is then used to trigger the sequential firing of two xenon sources which irradiate the particle with UV pulses at ~280 nm and ~370 nm, optimal for excitation of bio-fluorophores tryptophan and NADH (nicotinamide adenine dinucleotide) respectively. For each excitation wavelength, fluorescence is detected across two bands embracing the peak emissions of the same bio-fluorophores. Current measurement rates are up to ~125 particles/s, corresponding to all particles for concentrations up to 1.3 x 104 particles/l. Developments to increase this to ~500 particles/s are in hand. Device sensitivity is illustrated in preliminary data recorded from aerosols of E.coli, BG spores, and a variety of non-biological materials.

  12. Single particle multichannel bio-aerosol fluorescence sensor

    Science.gov (United States)

    Kaye, P. H.; Stanley, W. R.; Hirst, E.; Foot, E. V.; Baxter, K. L.; Barrington, S. J.

    2005-05-01

    We describe a prototype low-cost multi-channel aerosol fluorescence sensor designed for unattended deployment in medium to large area bio-aerosol detection networks. Individual airborne particles down to ~1μm in size are detected and sized by measurement of light scattered from a continuous-wave diode laser (660nm). This scatter signal is then used to trigger the sequential firing of two xenon sources which irradiate the particle with UV pulses at ~280 nm and ~370 nm, optimal for excitation of bio-fluorophores tryptophan and NADH (nicotinamide adenine dinucleotide) respectively. For each excitation wavelength, fluorescence is detected across two bands embracing the peak emissions of the same bio-fluorophores. Current measurement rates are up to ~125 particles/s, corresponding to all particles for concentrations up to 1.3 x 104 particles/l. Developments to increase this to ~500 particles/s are in hand. Device sensitivity is illustrated in preliminary data recorded from aerosols of E.coli, BG spores, and a variety of non-biological materials.

  13. MULTICHANNEL COGNITIVE CROSS LAYER OPTIMIZATION FOR IMPROVED VIDEO TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Manimekalai Thirunavukkarasu

    2013-01-01

    Full Text Available Multimedia applications particularly real-time video transmission in wireless networks, envisions end to end user perceived video quality as an important QoS parameter to be achieved. Cognitive Radio promising efficient spectrum utilization combined with Cross layer optimization is seen as a powerful combination to achieve the desired video quality. This study proposes Optimal Channel Sensed Multichannel Cognitive MAC (OCSM-CMAC, a QoS driven cross layer system for the joint optimization of different network parameters along the network protocol stack for the improved video transmission. The primary network activity and wireless propagation dependent channel quality are modeled. Depending on the availability of the primary channel and channel condition as provided by an optimal sensing scheme and the encoder parameter in the application layer, cognitive MAC scheduling and PHY layer modulation and coding for the secondary user are optimized to achieve the required QoS. The simulation of channel and the cognitive user activity is done in MATLAB, while the application video coding is performed by H.264/AVC JM 15.1 codec to obtain the results. The results of the proposed OCSM-CMAC scheme demonstrate that improved PSNR and delay performance is achieved under the optimal channel sensing scheme compared to the random sensing scheme.

  14. The Role of Multichannel Marketing in Customer Retention and Loyalty: Study in Emerald Bank Customer in Indonesia

    National Research Council Canada - National Science Library

    Ambarwati, Ambarwati

    Attention on the relationship between customer retention, customer loyalty, and customer satisfaction that serves as "seed" of customer loyalty highlight the important factors for multichannel management...

  15. Sea Legs

    Science.gov (United States)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  16. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to op

  17. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to op

  18. Study of Effect of Raw Data Compression on Azimuth Multi-channel SAR System

    Directory of Open Access Journals (Sweden)

    Zhao Yao

    2017-08-01

    Full Text Available An effective way to achieve High Resolution and Wide Swath (HRWS imaging capability is the multi-channel technique in azimuth. Improved resolution and swath can dramatically increase the volume of echo data in the SAR system. However, the onboard data storage and data-transmission bandwidth are limited, so data compression technique is typically used to reduce the volume of echo data. To study the effect of raw data compression on the azimuth multi-channel SAR system, in this paper, we establish a multi-channel SAR signal model based on data compression. We then derive and analyze the effects of data compression on the Signal-to-Noise Ratio (SNR scaling factor of the multi-channel SAR system and quantization noise. Finally, we verify the validity of the proposed model and analysis results using simulation and real data and discuss the effect of data compression on the Peek-to-Ghost Ratio (PGR. The results of this paper provide an important theoretical basis for the choice of compression method in the multi-channel SAR system.

  19. Advanced technology for a satellite multichannel demultiplexer/demodulator

    Science.gov (United States)

    Abramovitz, Irwin J.; Flechsig, Drew E.; Matteis, Richard M., Jr.

    1994-01-01

    Satellite on-board processing is needed to efficiently service multiple users while at the same time minimizing earth station complexity. The processing satellite receives a wideband uplink at 30 GHz and down-converts it to a suitable intermediate frequency. A multichannel demultiplexer then separates the composite signal into discrete channels. Each channel is then demodulated by bulk demodulators, with the baseband signals routed to the downlink processor for retransmission to the receiving earth stations. This type of processing circumvents many of the difficulties associated with traditional bent-pipe repeater satellites. Uplink signal distortion and interference are not retransmitted on the downlink. Downlink power can be allocated in accordance with user needs, independent of uplink transmissions. This allows the uplink users to employ different data rates as well as different modulation and coding schemes. In addition, all downlink users have a common frequency standard and symbol clock on the satellite, which is useful for network synchronization in time division multiple access schemes. The purpose of this program is to demonstrate the concept of an optically implemented multichannel demultiplexer (MCD). A proof-of-concept (POC) model has been developed which has the ability to receive a 40 MHz wide composite signal consisting of up to 1000 40 kHz QPSK modulated channels and perform the demultiplexing process. In addition a set of special test equipment (STE) has been configured to evaluate the performance of the POC model. The optical MCD is realized as an acousto-optic spectrum analyzer utilizing the capability of Bragg cells to perform the required channelization. These Bragg cells receive an optical input from a laser source and an RF input (the signal). The Bragg interaction causes optical output diffractions at angles proportional to the RF input frequency. These discrete diffractions are optically detected and output to individual demodulators for

  20. Stacked, filtered multi-channel X-ray diode array

    Science.gov (United States)

    MacNeil, L. P.; Dutra, E. C.; Compton, S. M.; Jacoby, B. A.; Raphaelian, M. L.

    2015-08-01

    There are many types of X-ray diodes that are used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need arose for a low cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustness and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. We fielded individual and stacked systems at several national facilities as ancillary `ride-along' diagnostics to test and improve the design usability. We present the MiniXRD system performance which supports consideration as a viable low-cost alternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.

  1. A CMOS Neural Interface for a Multichannel Vestibular Prosthesis.

    Science.gov (United States)

    Hageman, Kristin N; Kalayjian, Zaven K; Tejada, Francisco; Chiang, Bryce; Rahman, Mehdi A; Fridman, Gene Y; Dai, Chenkai; Pouliquen, Philippe O; Georgiou, Julio; Della Santina, Charles C; Andreou, Andreas G

    2016-04-01

    We present a high-voltage CMOS neural-interface chip for a multichannel vestibular prosthesis (MVP) that measures head motion and modulates vestibular nerve activity to restore vision- and posture-stabilizing reflexes. This application specific integrated circuit neural interface (ASIC-NI) chip was designed to work with a commercially available microcontroller, which controls the ASIC-NI via a fast parallel interface to deliver biphasic stimulation pulses with 9-bit programmable current amplitude via 16 stimulation channels. The chip was fabricated in the ONSemi C5 0.5 micron, high-voltage CMOS process and can accommodate compliance voltages up to 12 V, stimulating vestibular nerve branches using biphasic current pulses up to 1.45±0.06 mA with durations as short as 10 μs/phase. The ASIC-NI includes a dedicated digital-to-analog converter for each channel, enabling it to perform complex multipolar stimulation. The ASIC-NI replaces discrete components that cover nearly half of the 2nd generation MVP (MVP2) printed circuit board, reducing the MVP system size by 48% and power consumption by 17%. Physiological tests of the ASIC-based MVP system (MVP2A) in a rhesus monkey produced reflexive eye movement responses to prosthetic stimulation similar to those observed when using the MVP2. Sinusoidal modulation of stimulus pulse rate from 68-130 pulses per second at frequencies from 0.1 to 5 Hz elicited appropriately-directed slow phase eye velocities ranging in amplitude from 1.9-16.7 °/s for the MVP2 and 2.0-14.2 °/s for the MVP2A. The eye velocities evoked by MVP2 and MVP2A showed no significant difference ( t-test, p=0.34), suggesting that the MVP2A achieves performance at least as good as the larger MVP2.

  2. Stacked, filtered multi-channel X-ray diode array

    Energy Technology Data Exchange (ETDEWEB)

    MacNeil, Lawrence [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Dutra, Eric [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Raphaelian, Mark [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Compton, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jacoby, Barry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-01

    There are many types of X-ray diodes used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need exists for a low-cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustness and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. The authors fielded individual and stacked systems at several national facilities as ancillary "ride-along" diagnostics to test and improve the design usability. This paper presents the MiniXRD system performance, which supports consideration as a viable low-costalternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.

  3. Multichannel activity propagation across an engineered axon network

    Science.gov (United States)

    Chen, H. Isaac; Wolf, John A.; Smith, Douglas H.

    2017-04-01

    . These results provide insight into how the brain potentially processes information and generates the neural code and could guide the development of clinical therapies based on multichannel brain stimulation.

  4. A Wireless Headstage for Combined Optogenetics and Multichannel Electrophysiological Recording.

    Science.gov (United States)

    Gagnon-Turcotte, Gabriel; LeChasseur, Yoan; Bories, Cyril; Messaddeq, Younes; De Koninck, Yves; Gosselin, Benoit

    2017-02-01

    This paper presents a wireless headstage with real-time spike detection and data compression for combined optogenetics and multichannel electrophysiological recording. The proposed headstage, which is intended to perform both optical stimulation and electrophysiological recordings simultaneously in freely moving transgenic rodents, is entirely built with commercial off-the-shelf components, and includes 32 recording channels and 32 optical stimulation channels. It can detect, compress and transmit full action potential waveforms over 32 channels in parallel and in real time using an embedded digital signal processor based on a low-power field programmable gate array and a Microblaze microprocessor softcore. Such a processor implements a complete digital spike detector featuring a novel adaptive threshold based on a Sigma-delta control loop, and a wavelet data compression module using a new dynamic coefficient re-quantization technique achieving large compression ratios with higher signal quality. Simultaneous optical stimulation and recording have been performed in-vivo using an optrode featuring 8 microelectrodes and 1 implantable fiber coupled to a 465-nm LED, in the somatosensory cortex and the Hippocampus of a transgenic mouse expressing ChannelRhodospin (Thy1::ChR2-YFP line 4) under anesthetized conditions. Experimental results show that the proposed headstage can trigger neuron activity while collecting, detecting and compressing single cell microvolt amplitude activity from multiple channels in parallel while achieving overall compression ratios above 500. This is the first reported high-channel count wireless optogenetic device providing simultaneous optical stimulation and recording. Measured characteristics show that the proposed headstage can achieve up to 100% of true positive detection rate for signal-to-noise ratio (SNR) down to 15 dB, while achieving up to 97.28% at SNR as low as 5 dB. The implemented prototype features a lifespan of up to 105

  5. Note: Design and investigation of a multichannel plasma-jet triggered gas switch.

    Science.gov (United States)

    Tie, Weihao; Liu, Xuandong; Zhang, Qiaogen; Liu, Shanhong

    2014-07-01

    We described the fabrication and testing of a multichannel plasma-jet triggered gas switch (MPJTGS). A novel six-channel annular micro-plasma-gun was embedded in the trigger electrode to generate multichannel plasma jets as a nanosecond trigger pulse arrived. The gas breakdown in multiple sites of the spark gap was induced and fixed around jet orifices by the plasma jets. We tested the multichannel discharge characteristics of the MPJTGS in two working modes with charge voltage of 50 kV, trigger voltage of +40 kV (25 ns rise time), and trigger energy of 240 J, 32 J, and 2 J, respectively, at different working coefficients. Results show that the average number of discharge channels increased as the trigger energy increased, and decreased as the working coefficient decreased. At a working coefficient of 87.1% and trigger energy of 240 J, the average number of discharge channels in Mode II could reach 4.1.

  6. Multichannel decision feedback equalizer for high track density in optical recording

    Science.gov (United States)

    Gopalaswamy, Srinivasan; Kumar, B. V. K.

    1996-08-01

    A possible approach to high track density in optical recording is to reduce the track widths and eliminate the spacing between consecutive tracks. Parallel readback of several tracks and combined equalization of the multitrack readback signals is a viable approach toward reducing the deteriorating effects of interference in such a high-track- density system. Multichannel readback using laser diode arrays has been reported in optical recording. An additional advantage of multitrack readback is a high data rate. A novel multichannel decision feedback equalizer to reduce interference both within and across the tracks using 2D feedback is presented. Simulation results shows good improvement in error-rate performance by using multichannel decision feedback equalization. By this readback method, tracks can be brought closer, thus increasing the areal density.

  7. Simultaneous Greedy Analysis Pursuit for compressive sensing of multi-channel ECG signals.

    Science.gov (United States)

    Avonds, Yurrit; Liu, Yipeng; Van Huffel, Sabine

    2014-01-01

    This paper addresses compressive sensing for multi-channel ECG. Compared to the traditional sparse signal recovery approach which decomposes the signal into the product of a dictionary and a sparse vector, the recently developed cosparse approach exploits sparsity of the product of an analysis matrix and the original signal. We apply the cosparse Greedy Analysis Pursuit (GAP) algorithm for compressive sensing of ECG signals. Moreover, to reduce processing time, classical signal-channel GAP is generalized to the multi-channel GAP algorithm, which simultaneously reconstructs multiple signals with similar support. Numerical experiments show that the proposed method outperforms the classical sparse multi-channel greedy algorithms in terms of accuracy and the single-channel cosparse approach in terms of processing speed.

  8. A Fast Image Retrieval Algorithm with Multi-Channel Textural Features in PACS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong; YANG Yan; QIN Qian-qing

    2005-01-01

    The paper presents a fast algorithm for image retrieval using multi-channel textural features in medical picture archiving and communication system (PACS). By choosing different linear or nonlinear operators in prediction and update lifting step, the linear or nonlinear M-band wavelet decomposition can be achieved in Mband lifting. It provides the advantages such as fast transform, in-place calculation and integer-integer transform. The set of wavelet moment forms multi-channel textural feature vector related to the texture distribution of each wavelet images. The experimental results of CT image database show that the retrieval approach of multi-channel textural features is effective for image indexing and has lower computational complexity and less memory. It is much easier to implement in hardware and suitable for the applications of real time medical processing system.

  9. [Software development of multi-element transient signal acquisition and processing with multi-channel ICP-AES].

    Science.gov (United States)

    Zhang, Y; Zhuang, Z; Wang, X; Zhu, E; Liu, J

    2000-02-01

    A software for multi-channel ICP-AES multi-element transient signal acquisition and processing were developed in this paper. It has been successfully applied to signal acquisition and processing in many transient introduction techniques on-line hyphenated with multi-channel ICP-AES.

  10. Development of Ribbon Fiber Type Multi-Channel Power Level Monitor with Low-Insertion/Polarization Loss

    Institute of Scientific and Technical Information of China (English)

    Maki; Inai; Akira; Haraguchi; Takeo; Komiya; Kiyotaka; Murashima; Takashi; Sasaki; Kazuhito; Saitoh

    2003-01-01

    We would like to propose a new in-line multi-channel power level monitor, which is applicable as tap-monitor for multi-channel WDM signals. Its ribbon fiber structure has far exceeded PLC performance and realized compact-size and lower insertion/polarization dependent loss.

  11. Multi-channel distributed coordinated function over single radio in wireless sensor networks.

    Science.gov (United States)

    Campbell, Carlene E-A; Loo, Kok-Keong Jonathan; Gemikonakli, Orhan; Khan, Shafiullah; Singh, Dhananjay

    2011-01-01

    Multi-channel assignments are becoming the solution of choice to improve performance in single radio for wireless networks. Multi-channel allows wireless networks to assign different channels to different nodes in real-time transmission. In this paper, we propose a new approach, Multi-channel Distributed Coordinated Function (MC-DCF) which takes advantage of multi-channel assignment. The backoff algorithm of the IEEE 802.11 distributed coordination function (DCF) was modified to invoke channel switching, based on threshold criteria in order to improve the overall throughput for wireless sensor networks (WSNs) over 802.11 networks. We presented simulation experiments in order to investigate the characteristics of multi-channel communication in wireless sensor networks using an NS2 platform. Nodes only use a single radio and perform channel switching only after specified threshold is reached. Single radio can only work on one channel at any given time. All nodes initiate constant bit rate streams towards the receiving nodes. In this work, we studied the impact of non-overlapping channels in the 2.4 frequency band on: constant bit rate (CBR) streams, node density, source nodes sending data directly to sink and signal strength by varying distances between the sensor nodes and operating frequencies of the radios with different data rates. We showed that multi-channel enhancement using our proposed algorithm provides significant improvement in terms of throughput, packet delivery ratio and delay. This technique can be considered for WSNs future use in 802.11 networks especially when the IEEE 802.11n becomes popular thereby may prevent the 802.15.4 network from operating effectively in the 2.4 GHz frequency band.

  12. Well log interpretation and seismic character of the cenozoic sequence in the northern Alboran Sea

    Science.gov (United States)

    Jurado, M. J.; Comas, M. C.

    1992-06-01

    Seismic stratigraphic and main lithological features of the sedimentary cover overlying the basement of the Alboran Sea were established via the analysis of commercial multichannel seismic surveys, geophysical well logs, and well data. Six seismic stratigraphics units (VI to I), bounded by unconformities, form the marine sediments that range in age from early Miocene to Quaternary. They are dated by extrapolation of commercial drilling results from the northern Alboran Sea. Volcanic activity is recorded within sedimentary sequences of units V to II. Undercompaction features are detected in the two basal units.

  13. Pulse-width tunable multi-channel NRZ-to-RZ conversion with duplicate output

    Science.gov (United States)

    Yu, Yu; Zhang, Xinliang; Huang, Dexiu

    2012-01-01

    We demonstrate multi-channel non-return-to-zero (NRZ) to return-to-zero (RZ) conversions with tunable output pulse-width and single-to-dual function, using a phase modulator and an array waveguide grating (AWG), which acts both detuned multi-channel filter and demultiplexer. Four-channel NRZ signals after transmission can be converted to eight-channel RZ signals with timing jitter and extinction ratio improvement. Further transmission and bit error ratio (BER) measurements for the converted RZ signal show a good performance compared with conventional one.

  14. Spatial aspects of sound quality - and by multichannel systems subjective assessment of sound reproduced by stereo

    DEFF Research Database (Denmark)

    Choisel, Sylvain

    the fidelity with which sound reproduction systems can re-create the desired stereo image, a laser pointing technique was developed to accurately collect subjects' responses in a localization task. This method is subsequently applied in an investigation of the effects of loudspeaker directivity...... on the perceived direction of panned sources. The second part of the thesis addresses the identification of auditory attributes which play a role in the perception of sound reproduced by multichannel systems. Short musical excerpts were presented in mono, stereo and several multichannel formats to evoke various...

  15. Analysis of Channel-aware Multichannel ALOHA in OFDMA Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    Zhang Yumei; Sheng Yu

    2009-01-01

    Orthogonal frequency division multiple access (OFDMA) systems provide multiple channels that can be accessed via random access schemes. In this paper a channel-aware multichannel random access, based on local channel state information (CSI), was investigated and a multichannel slotted ALOHA scheme was proposed accordingly. Also an analytical investigation of total system throughput and the queue state evolution of generic node in the network were present by assuming the channel has been modeled by means of a two state Markov chain. Through the theoretical model and simulation results, we confirm that the proposed algorithm has the advantage of high throughput and low access delay.

  16. Blind source separation of multichannel electroencephalogram based on wavelet transform and ICA

    Institute of Scientific and Technical Information of China (English)

    You Rong-Yi; Chen Zhong

    2005-01-01

    Combination of the wavelet transform and independent component analysis (ICA) was employed for blind source separation (BSS) of multichannel electroencephalogram (EEG). After denoising the original signals by discrete wavelet transform, high frequency components of some noises and artifacts were removed from the original signals. The denoised signals were reconstructed again for the purpose of ICA, such that the drawback that ICA cannot distinguish noises from source signals can be overcome effectively. The practical processing results showed that this method is an effective way to BSS of multichannel EEG. The method is actually a combination of wavelet transform with adaptive neural network, so it is also useful for BBS of other complex signals.

  17. Study on the separation performance of the multi-channel reduced graphene oxide membranes

    Science.gov (United States)

    Zhao, Yongjiao; Li, Chun; Fan, Xiaoyan; Wang, Jiesheng; Yuan, Guang; Song, Xinxiang; Chen, Jing; Li, Zhangde

    2016-10-01

    The multi-channel reduced graphene oxide membranes with separation function have been synthesized by a simple hydrothermal reduction method and vacuum filtration. In the as-synthesized membranes, the size, number, and type of the nanochannels can be controlled by the reduced temperature. The flux and retention rate of solution are investigated by filtering different size dye molecules. The interception and adsorption effect in the separation process are discussed. Furthermore, the sizes of the nanochannels in the membranes prepared by the different reduced temperatures are estimated. The results indicate that the multi-channel reduced graphene oxide membranes have potential application in water purification area.

  18. Blind source separation of multichannel electroencephalogram based on wavelet transform and ICA

    Science.gov (United States)

    You, Rong-Yi; Chen, Zhong

    2005-11-01

    Combination of the wavelet transform and independent component analysis (ICA) was employed for blind source separation (BSS) of multichannel electroencephalogram (EEG). After denoising the original signals by discrete wavelet transform, high frequency components of some noises and artifacts were removed from the original signals. The denoised signals were reconstructed again for the purpose of ICA, such that the drawback that ICA cannot distinguish noises from source signals can be overcome effectively. The practical processing results showed that this method is an effective way to BSS of multichannel EEG. The method is actually a combination of wavelet transform with adaptive neural network, so it is also useful for BBS of other complex signals.

  19. Sea Ice

    Science.gov (United States)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  20. Development and implementation of own software for dosimetry multichannel film; Desarrollo e implementacion de un software propio para la dosimetria multicanal con pelicula radiocromica EBT2

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Feltstrom, D.; Reyes Garcia, R.; Luis Simon, F. J.; Carrasco Herrera, M.; Sanchez Carmona, G.; Herrador Cordoba, M.

    2013-07-01

    The objective of this work is to develop its own software for multichannel film dosimetry Radiochromic EBT2. Compare the results obtained with its use in multichannel and single-channel dosimetry. Check that the multi-channel dosimetry eliminates much of the artifacts caused by dirt, fingerprints, scratches, etc. Radiochromic in film and scanner devices. (Author)

  1. Sea level change

    Digital Repository Service at National Institute of Oceanography (India)

    Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

    This chapter considers changes in global mean sea level, regional sea level, sea level extremes, and waves. Confidence in projections of global mean sea level rise has increased since the Fourth Assessment Report (AR4) because of the improved...

  2. The Time Division Multi-Channel Communication Model and the Correlative Protocol Based on Quantum Time Division Multi-Channel Communication

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Hui; PEI Chang-Xing; NIE Min

    2010-01-01

    @@ Based on the classical time division multi-channel communication theory,we present a scheme of quantum time-division multi-channel communication(QTDMC).Moreover,the model of quantum time division switch(QTDS)and correlative protocol of QTDMC are proposed.The quantum bit error rate(QBER)is analyzed and the QBER simulation test is performed.The scheme shows that the QTDS can carry out multi-user communication through quantum channel,the QBER can also reach the reliability requirement of communication,and the protocol of QTDMC has high practicability and transplantable.The scheme of QTDS may play an important role in the establishment of quantum communication in a large scale in the future.

  3. Performance of Multi-Channel DBP with Long-haul Frequency-Referenced Transmission

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Da Ros, Francesco; Zibar, Darko

    2016-01-01

    The impact of frequency referenced WDM source on the performance of dual polarization multi-channel digital backpropagation (MC-DBP) is experimentally investigated up to 4000 km of transmission. For a system with 4 × 8 GBd DP-QPSK, such approach allows 0.6 dB more MC-DBP Q2-factor gain in the non...

  4. Using image synthesis for multi-channel registration of different image modalities

    Science.gov (United States)

    Chen, Min; Jog, Amod; Carass, Aaron; Prince, Jerry L.

    2015-01-01

    This paper presents a multi-channel approach for performing registration between magnetic resonance (MR) images with different modalities. In general, a multi-channel registration cannot be used when the moving and target images do not have analogous modalities. In this work, we address this limitation by using a random forest regression technique to synthesize the missing modalities from the available ones. This allows a single channel registration between two different modalities to be converted into a multi-channel registration with two mono-modal channels. To validate our approach, two openly available registration algorithms and five cost functions were used to compare the label transfer accuracy of the registration with (and without) our multi-channel synthesis approach. Our results show that the proposed method produced statistically significant improvements in registration accuracy (at an α level of 0.001) for both algorithms and all cost functions when compared to a standard multi-modal registration using the same algorithms with mutual information. PMID:26246653

  5. On the relationship between multi-channel envelope and temporal fine structure

    DEFF Research Database (Denmark)

    2011-01-01

    The envelope of a signal is broadly defined as the slow changes in time of the signal, where as the temporal fine structure (TFS) are the fast changes in time, i.e. the carrier wave(s) of the signal. The focus of this paper is on envelope and TFS in multi-channel systems. We discuss the differenc...

  6. Compact multichannel demultiplexer for WDM-POF networks based on spatially overlapped FBGs

    DEFF Research Database (Denmark)

    Saez-Rodriguez, D.; Nielsen, Kristian; Bang, Ole;

    2016-01-01

    The fabrication of spatially overlapped fibre Bragg gratings over microstructured polymer optical fibre allows to demonstrate low-cost and compact multichannel wavelength division demultiplexers. Coarse and dense wavelengths in high-capacity optical systems have been demonstrated for reduced size...

  7. A microprocessor based, multi-channel low-temperature monitoring system

    NARCIS (Netherlands)

    Kuiper, B.W.; Dijk, van M.H.H.

    1982-01-01

    A multi-channel low-temperature monitoring system and its design considerations are presented. The system is microprocessor based and specially designed to interface thermoresistive sensors in cryogenic experiments. The system can be easily expanded to accept any type of physical transducer and to p

  8. Electro-Optical Multichannel Spectrometer for Transient Resonance Raman and Absorption Spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Karina Benthin; Wilbrandt, Robert Walter; Pagsberg, Palle Bjørn

    1979-01-01

    An optical multichannel system is described, used for time‐dependent absorption measurements in the gas phase and the liquid phase and for resonance Raman spectroscopy of short‐lived transient species in the liquid phase in pulse radiolysis. It consists of either an image converter streak unit or...

  9. Adaptive multichannel control of time-varying broadband noise and vibrations

    NARCIS (Netherlands)

    Berkhoff, A.P.

    2010-01-01

    This paper presents results obtained from a number of applications in which a recent adaptive algorithm for broadband multichannel active noise control is used. The core of the algorithm uses the inverse of the minimum-phase part of the secondary path for improvement of the speed of convergence. A f

  10. Autonomous transmission power adaptation for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2008-09-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in WMNs. Previous studies have emphasized throughput maximization in such systems as the main design challenge and transmission power control treated as a secondary issue...

  11. Autonomous transmission power adaptation for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-09-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in WMNs. Previous studies have emphasized through- put maximization in such systems as the main design challenge and transmission power control treated as a secondary issue...

  12. Data-Driven Visualization and Group Analysis of Multichannel EEG Coherence with Functional Units

    NARCIS (Netherlands)

    Caat, Michael ten; Maurits, Natasha M.; Roerdink, Jos B.T.M.

    2008-01-01

    A typical data- driven visualization of electroencephalography ( EEG) coherence is a graph layout, with vertices representing electrodes and edges representing significant coherences between electrode signals. A drawback of this layout is its visual clutter for multichannel EEG. To reduce clutter, w

  13. Multi-Channel Deconvolution for Forward-Looking Phase Array Radar Imaging

    Directory of Open Access Journals (Sweden)

    Jie Xia

    2017-07-01

    Full Text Available The cross-range resolution of forward-looking phase array radar (PAR is limited by the effective antenna beamwidth since the azimuth echo is the convolution of antenna pattern and targets’ backscattering coefficients. Therefore, deconvolution algorithms are proposed to improve the imaging resolution under the limited antenna beamwidth. However, as a typical inverse problem, deconvolution is essentially a highly ill-posed problem which is sensitive to noise and cannot ensure a reliable and robust estimation. In this paper, multi-channel deconvolution is proposed for improving the performance of deconvolution, which intends to considerably alleviate the ill-posed problem of single-channel deconvolution. To depict the performance improvement obtained by multi-channel more effectively, evaluation parameters are generalized to characterize the angular spectrum of antenna pattern or singular value distribution of observation matrix, which are conducted to compare different deconvolution systems. Here we present two multi-channel deconvolution algorithms which improve upon the traditional deconvolution algorithms via combining with multi-channel technique. Extensive simulations and experimental results based on real data are presented to verify the effectiveness of the proposed imaging methods.

  14. Schwinger multichannel study of the 2Pi(g) shape resonance in N2

    Science.gov (United States)

    Huo, Winifred M.; Gibson, Thomas L.; Lima, Marco A. P.; Mckoy, Vincent

    1987-01-01

    The results of a study on electron-target correlations in the 2Pi(g) shape resonance of elastic e-N2 scattering, using the Schwinger multichannel formulation, are reported. The effects of basis set, orbital representation, and closed-channel-configurations are delineated. The different roles of radial and angular correlations are compared.

  15. E-Fulfillment and Multi-Channel Distribution – A Review

    NARCIS (Netherlands)

    N.A.H. Agatz (Niels); M. Fleischmann (Moritz); J.A.E.E. van Nunen (Jo)

    2006-01-01

    textabstractThis review addresses the specific supply chain management issues of Internet fulfillment in a multi-channel environment. It provides a systematic overview of managerial planning tasks and reviews corresponding quantitative models. In this way, we aim to enhance the understanding of mult

  16. A possible edge effect in enhanced network. [solar K-line observations by multichannel spectrometer

    Science.gov (United States)

    Jones, H. P.; Brown, D. R.

    1977-01-01

    K-line observations of enhanced network taken with the NASA/SPO Multichannel Spectrometer on September 28, 1975, in support of OSO-8 are discussed. The data show a correlation between core brightness and asymmetry for spatial scans which cross enhanced network boundaries. The implications of this result concerning mass flow in and near supergranule boundaries are discussed.

  17. Multichannel active noise control systems and algorithms for reduction on broadband noise

    NARCIS (Netherlands)

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

    2007-01-01

    Active noise contral systems for braadband noise reduction require substantial computing power, especially for multichannel systems and adaptive controllers. Furthermore, speed of convergence can be an issue as weil. In this paper, methods and techniques are described that are able to reduce the com

  18. On-Line Multichannel Raman Spectroscopic Detection System For Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An on-line multichannel Raman spectroscopic detection system for capillary electrophoresis was established by using an Ar+ laser and a cryogenically cooled ICCD. Resonant excitation Raman spectra of methyl red and methyl orange were employed to test the system. The result shows that it could yield on-line electrophoretogram and time series of Raman spectra.

  19. Fast affine projections and the regularized modified filtered-error algorithm in multichannel active noise control

    NARCIS (Netherlands)

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

    2008-01-01

    In this paper, real-time results are given for broadband multichannel active noise control using the regularized modified filtered-error algorithm. As compared to the standard filtered-error algorithm, the improved convergence rate and stability of the algorithm are obtained by using an inner-outer

  20. Comparison of the single channel and multichannel (multivariate) concepts of selectivity in analytical chemistry.

    Science.gov (United States)

    Dorkó, Zsanett; Verbić, Tatjana; Horvai, George

    2015-07-01

    Different measures of selectivity are in use for single channel and multichannel linear analytical measurements, respectively. It is important to understand that these two measures express related but still distinctly different features of the respective measurements. These relationships are clarified by introducing new arguments. The most widely used selectivity measure of multichannel linear methods (which is based on the net analyte signal, NAS, concept) expresses the sensitivity to random errors of a determination where all bias from interferents is computationally eliminated using pure component spectra. The conventional selectivity measure of single channel linear measurements, on the other hand, helps to estimate the bias caused by an interferent in a biased measurement. In single channel methods expert knowledge about the samples is used to limit the possible range of interferent concentrations. The same kind of expert knowledge allows improved (lower mean squared error, MSE) analyte determinations also in "classical" multichannel measurements if those are intractable due to perfect collinearity or to high noise inflation. To achieve this goal bias variance tradeoff is employed, hence there remains some bias in the results and therefore the concept of single channel selectivity can be extended in a natural way to multichannel measurements. This extended definition and the resulting selectivity measure can also be applied to the so-called inverse multivariate methods like partial least squares regression (PLSR), principal component regression (PCR) and ridge regression (RR).

  1. Design and evaluation of tiled parallel coordinate visualization of multichannel EEG data

    NARCIS (Netherlands)

    Caat, Michael ten; Maurits, Natasha M.; Roerdink, Jos B.T.M.

    2007-01-01

    The field of visualization assists data interpretation in many areas, but does not manage all types of data equally well. This holds, in particular, for time-varying multichannel EEG data. No existing method can successfully visualize simultaneous information from all channels in use at all time ste

  2. Optical Methods For Transient Plasmas Studies By Multichannel TEA Nitrogen Laser

    Science.gov (United States)

    Ursu, Ioan; Popescu, Ion M.; Ivascu, M.; Baltog, I.; Mihut, L.; Zambreanu, V.; Zoita, V.

    1989-05-01

    A multichannel TEA nitrogen laser has been realized for some optical diagnostics. The following methods have been applied on the plasma focus device (PFD): interferometry, schlieren, shadowgraphy and a new combination of the last two. The background of these methods and some qualitative and quantitative results obtained in plasma focus (PF) studies are presented.

  3. A possible edge effect in enhanced network. [solar K-line observations by multichannel spectrometer

    Science.gov (United States)

    Jones, H. P.; Brown, D. R.

    1977-01-01

    K-line observations of enhanced network taken with the NASA/SPO Multichannel Spectrometer on September 28, 1975, in support of OSO-8 are discussed. The data show a correlation between core brightness and asymmetry for spatial scans which cross enhanced network boundaries. The implications of this result concerning mass flow in and near supergranule boundaries are discussed.

  4. Multi-channel holographic birfurcative neural network system for real-time adaptive EOS data analysis

    Science.gov (United States)

    Liu, Hua-Kuang; Diep, J.; Huang, K.

    1991-01-01

    Viewgraphs on multi-channel holographic bifurcative neural network system for real-time adaptive Earth Observing System (EOS) data analysis are presented. The objective is to research and develop an optical bifurcating neuromorphic pattern recognition system for making optical data array comparisons and to evaluate the use of the system for EOS data classification, reduction, analysis, and other applications.

  5. Designing Multi-Channel Web Frameworks for Cultural Tourism Applications: The MUSE Case Study.

    Science.gov (United States)

    Garzotto, Franca; Salmon, Tullio; Pigozzi, Massimiliano

    A framework for the design of multi-channel (MC) applications in the cultural tourism domain is presented. Several heterogeneous interface devices are supported including location-sensitive mobile units, on-site stationary devices, and personalized CDs that extend the on-site experience beyond the visit time thanks to personal memories gathered…

  6. On Optimal Multichannel Mean-Squared Error Estimators for Speech Enhancement

    NARCIS (Netherlands)

    Hendriks, R.C.; Heusdens, R.; Kjems, U.; Jensen, J.

    2009-01-01

    In this letter we present discrete Fourier transform (DFT) domain minimum mean-squared error (MMSE) estimators for multichannel noise reduction. The estimators are derived assuming that the clean speech magnitude DFT coefficients are generalized-Gamma distributed. We show that for Gaussian

  7. Design and Evaluation of Tiled Parallel Coordinate Visualization of Multichannel EEG Data

    NARCIS (Netherlands)

    Caat, Michael ten; Maurits, Natasha M.; Roerdink, Jos B.T.M.

    2006-01-01

    The field of visualization assists data interpretation in many areas, but does not manage all types of data equally well. This holds in particular for time-varying multichannel EEG data. No existing method can successfully visualize simultaneous information from all channels in use at all time steps

  8. Tiled Parallel Coordinates for the Visualization of Time-Varying Multichannel EEG Data

    NARCIS (Netherlands)

    Caat, M. ten; Maurits, N.M.; Roerdink, J.B.T.M.

    2005-01-01

    The field of visualization assists data interpretation in many areas, but some types of data are not manageable by existing visualization techniques. This holds in particular for time-varying multichannel EEG data. No existing technique can simultaneously visualize information from all channels in u

  9. Self-adaptive method for high frequency multi-channel analysis of surface wave method

    Science.gov (United States)

    When the high frequency multi-channel analysis of surface waves (MASW) method is conducted to explore soil properties in the vadose zone, existing rules for selecting the near offset and spread lengths cannot satisfy the requirements of planar dominant Rayleigh waves for all frequencies of interest ...

  10. Preparation of uniaxial multichannel silk fibroin scaffolds for guiding primary neurons.

    Science.gov (United States)

    Zhang, Qiang; Zhao, Yahong; Yan, Shuqin; Yang, Yumin; Zhao, Huijing; Li, Mingzhong; Lu, Shenzhou; Kaplan, David L

    2012-07-01

    Physical guidance cues have been exploited to stimulate neuron adhesion and neurite outgrowth. In the present study, three-dimensional (3-D) silk fibroin scaffolds with uniaxial multichannels (42-142 μm in diameter) were prepared by a directional temperature field freezing technique, followed by lyophilization. By varying the initial silk fibroin concentration, the chemical potential and quantity of free water around cylindrical ice crystals could be controlled to control the cross-section morphology of the scaffold channels. Aligned ridges also formed on the inner surface of the multichannels in parallel to the direction of the channels. In vitro, primary hippocampal neurons were seeded in these 3-D silk fibroin scaffolds with uniaxial multichannels of ∼120 μm in diameter. The morphology of the neurons was multipolar and alignment along the scaffold channels was observed. Cell-cell networks and cell-matrix interactions established by newly formed axons were observed after 7 days in culture. These neurons expressed β-III-tubulin, nerve filament and microtubule-associated protein, while glial fibrillary acidic protein immunofluorescence was barely above background. The ridges on the inner surface of the channels played a critical role in the adhesion and extension of neurons by providing continuous contact guidance. These new 3-D silk scaffolds with uniaxial multichannels provided a favorable microenvironment for the development of hippocampal neurons by guiding axonal elongation and cell migration.

  11. Multichannel Learning Research Applied to Principles of Television Production: A Review and Synthesis of the Literature.

    Science.gov (United States)

    Hanson, LuEtt

    1989-01-01

    Reviews multichannel learning research to find the best ways to combine audio and video in television to improve learning, and summarizes the research findings into principles for instructional television production. Highlights include the effects of redundancy on learning and on audience attention, message clarity, and problems in instructional…

  12. A Multichannel Calorimetric Simultaneous Assay Platform Using a Microampere Constant-Current Looped Enthalpy Sensor Array

    Science.gov (United States)

    Wei, Hsien-Chin; Huang, Su-Hua; Jiang, Joe-Air; Lee, Yeun-Chung

    2017-01-01

    Calorimetric biochemical measurements offer various advantages such as low waste, low cost, low sample consumption, short operating time, and labor-savings. Multichannel calorimeters can enhance the possibility of performing higher-throughput biochemical measurements. An enthalpy sensor (ES) array is a key device in multichannel calorimeters. Most ES arrays use Wheatstone bridge amplifiers to condition the sensor signals, but such an approach is only suitable for null detection and low resistance sensors. To overcome these limitations, we have developed a multichannel calorimetric simultaneous assay (MCSA) platform. An adjustable microampere constant-current (AMCC) source was designed for exciting the ES array using a microampere current loop measurement circuit topology. The MCSA platform comprises a measurement unit, which contains a multichannel calorimeter and an automatic simultaneous injector, and a signal processing unit, which contains multiple ES signal conditioners and a data processor. This study focused on the construction of the MCSA platform; in particular, construction of the measurement circuit and calorimeter array in a single block. The performance of the platform, including current stability, temperature sensitivity and heat sensitivity, was evaluated. The sensor response time and calorimeter constants were given. The capability of the platform to detect relative enzyme activity was also demonstrated. The experimental results show that the proposed MCSA is a flexible and powerful biochemical measurement device with higher throughput than existing alternatives. PMID:28165412

  13. A Multichannel Calorimetric Simultaneous Assay Platform Using a Microampere Constant-Current Looped Enthalpy Sensor Array

    Directory of Open Access Journals (Sweden)

    Hsien-Chin Wei

    2017-02-01

    Full Text Available Calorimetric biochemical measurements offer various advantages such as low waste, low cost, low sample consumption, short operating time, and labor-savings. Multichannel calorimeters can enhance the possibility of performing higher-throughput biochemical measurements. An enthalpy sensor (ES array is a key device in multichannel calorimeters. Most ES arrays use Wheatstone bridge amplifiers to condition the sensor signals, but such an approach is only suitable for null detection and low resistance sensors. To overcome these limitations, we have developed a multichannel calorimetric simultaneous assay (MCSA platform. An adjustable microampere constant-current (AMCC source was designed for exciting the ES array using a microampere current loop measurement circuit topology. The MCSA platform comprises a measurement unit, which contains a multichannel calorimeter and an automatic simultaneous injector, and a signal processing unit, which contains multiple ES signal conditioners and a data processor. This study focused on the construction of the MCSA platform; in particular, construction of the measurement circuit and calorimeter array in a single block. The performance of the platform, including current stability, temperature sensitivity and heat sensitivity, was evaluated. The sensor response time and calorimeter constants were given. The capability of the platform to detect relative enzyme activity was also demonstrated. The experimental results show that the proposed MCSA is a flexible and powerful biochemical measurement device with higher throughput than existing alternatives.

  14. Concept of a multichannel spin-resolving electron analyzer based on Mott scattering

    Energy Technology Data Exchange (ETDEWEB)

    Strocov, Vladimir N., E-mail: vladimir.strocov@psi.ch [Paul Scherrer Institute, CH-5232 Villigen-PSI (Switzerland); Petrov, Vladimir N. [St Petersburg Polytechnical University, Polytechnicheskaya Str. 29, St Petersburg RU-195251 (Russian Federation); Dil, J. Hugo [Paul Scherrer Institute, CH-5232 Villigen-PSI (Switzerland); École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland)

    2015-04-10

    The concept of a two-dimensional multichannel electron spin detector based on Mott scattering and imaging-type electron optics is presented. The efficiency increase of about four orders of magnitude opens new scientific fields including buried magnetic interfaces. The concept of a multichannel electron spin detector based on optical imaging principles and Mott scattering (iMott) is presented. A multichannel electron image produced by a standard angle-resolving (photo) electron analyzer or microscope is re-imaged by an electrostatic lens at an accelerating voltage of 40 kV onto the Au target. Quasi-elastic electrons bearing spin asymmetry of the Mott scattering are imaged by magnetic lenses onto position-sensitive electron CCDs whose differential signals yield the multichannel spin asymmetry image. Fundamental advantages of this concept include acceptance of inherently divergent electron sources from the electron analyzer or microscope focal plane as well as small aberrations achieved by virtue of high accelerating voltages, as demonstrated by extensive ray-tracing analysis. The efficiency gain compared with the single-channel Mott detector can be a factor of more than 10{sup 4} which opens new prospects of spin-resolved spectroscopies in application not only to standard bulk and surface systems (Rashba effect, topological insulators, etc.) but also to buried heterostructures. The simultaneous spin detection combined with fast CCD readout enables efficient use of the iMott detectors at X-ray free-electron laser facilities.

  15. Closed-loop, multichannel experimentation using the open-source NeuroRighter electrophysiology platform

    Directory of Open Access Journals (Sweden)

    Jonathan Paul Newman

    2013-01-01

    Full Text Available Single neuron feedback control techniques, such as voltage clamp and dynamic clamp, have enabled numerous advances in our understanding of ion channels, electrochemical signaling, and neural dynamics. Although commercially available multichannel recording and stimulation systems are commonly used for studying neural processing at the network level, they provide little native support for real-time feedback. We developed the open-source NeuroRighter multichannel electrophysiology hardware and software platform for closed-loop multichannel control with a focus on accessibility and low cost. NeuroRighter allows 64 channels of stimulation and recording for around US $10,000, along with the ability to integrate with other software and hardware. Here, we present substantial enhancements to the NeuroRighter platform, including a redesigned desktop application, a new stimulation subsystem allowing arbitrary stimulation patterns, low-latency data servers for accessing data streams, and a new application programming interface (API for creating closed-loop protocols that can be inserted into NeuroRighter as plugin programs. This greatly simplifies the design of sophisticated real-time experiments without sacrificing the power and speed of a compiled programming language. Here we present a detailed description of NeuroRighter as a stand alone application, its plugin API, and an extensive set of case studies that highlight the system's abilities for conducting closed-loop, multichannel interfacing experiments.

  16. Calibration plan for the sea and land surface temperature radiometer

    Science.gov (United States)

    Smith, David L.; Nightingale, Tim J.; Mortimer, Hugh; Middleton, Kevin; Edeson, Ruben; Cox, Caroline V.; Mutlow, Chris T.; Maddison, Brian J.

    2013-10-01

    The Sea and Land Surface Temperature Radiometer (SLSTR) to be flown on ESA's Sentinel-3 mission is a multichannel scanning radiometer that will continue the 21-year datasets of the Along Track Scanning Radiometer (ATSR) series. As its name implies, measurements from SLSTR will be used to retrieve global sea surface temperatures to an uncertainty of SLSTR instrument, infrared calibration sources and alignment equipment. The calibration rig has been commissioned and results of these tests will be presented. Finally the authors will present the planning for the on-orbit monitoring and calibration activities to ensure that calibration is maintained. These activities include vicarious calibration techniques that have been developed through previous missions, and the deployment of ship-borne radiometers.

  17. Towards a satellite-based sea ice climate data record

    Science.gov (United States)

    Meier, W. N.; Fetterer, F.; Stroeve, J.; Cavalieri, D.; Parkinson, C.; Comiso, J.; Weaver, R.

    2005-12-01

    Sea ice plays an important role in the Earth's climate through its influence on the surface albedo, heat and moisture transfer between the ocean and the atmosphere, and the thermohaline circulation. Satellite data reveal that since 1979, summer Arctic sea ice has, overall, been declining at a rate of almost 8%/decade, with recent summers (beginning in 2002) being particularly low. The receding sea ice is having an effect on wildlife and indigenous peoples in the Arctic, and concern exists that these effects may become increasingly severe. Thus, a long-term, ongoing climate data record of sea ice is crucial for tracking the changes in sea ice and for assessing the significance of long-term trends. Since the advent of passive microwave satellite instruments in the early 1970s, sea ice has been one of the most consistently monitored climate parameters. There is now a 27+ year record of sea ice extent and concentration from multi-channel passive microwave radiometers that has undergone inter-sensor calibration and other quality controls to ensure consistency throughout the record. Several algorithms have been developed over the years to retrieve sea ice extent and concentration and two of the most commonly used algorithms, the NASA Team and Bootstrap, have been applied to the entire SMMR-SSM/I record to obtain a consistent time series. These algorithms were developed at NASA Goddard Space Flight Center and are archived at the National Snow and Ice Data Center. However, the complex surface properties of sea ice affect the microwave signature, and algorithms can yield ambiguous results; no single algorithm has been found to work uniformly well under all sea ice conditions. Thus there are ongoing efforts to further refine the algorithms and the time series. One approach is to develop data fusion methods to optimally combine sea ice fields from two or more algorithms. Another approach is to take advantage of the improved capabilities of JAXA's AMSR-E sensor on NASA's Aqua

  18. Locating the Caledonian Deformation Front in the Western Barents Sea

    Science.gov (United States)

    Shulgin, Alexey; Aarseth, Iselin; Faleide, Jan-Inge; Mjelde, Rolf; Huismans, Ritske

    2016-04-01

    The crustal architecture of the Paleozoic sedimentary basins and the underlying basement is still not fully understood in the Western Barents Sea region. It has been proposed that the major basins have developed along the structural framework inherited from the early Devonian Caledonian orogeny. However, the location of the Caledonian suture zone and its orientation and the extent of the deformation front are still poorly constrained and are ambiguous in the Barents Sea. Two orientations of the Caledonian Deformation Front (CDF) have been proposed earlier: north-south (from the potential fields data) and southwest-northeast (from seismic data). Knowledge of the spatial extent and orientation of the CDF has a major effect on our understanding of the evolution of the Barents Sea and provides important constrains on the basin-basement interaction. In 2014 a marine seismic experiment was conducted in the Western Barents Sea. One of the goals of the experiment is to discriminate between two proposed models and to constrain the location of the Caledonian Deformation front offshore northern Norway. We present the joint interpretation of collocated newly collected wide-angle seismic data (Ocean Bottom Seismometers) and reprocessing of the reflection seismic dataset (Multi-channel seismics) collected in the mid 80's, using modern computational techniques. The two seismic methods provide best resolution at different depth ranges, and in our modeling we combine the results from the two methods to constrain the location of the CDF along transect running Northwest-Southeast across the Western Barents Sea.

  19. The Western Barents Sea: where is the Caledonian Deformation Front?

    Science.gov (United States)

    Shulgin, Alexey; Aarseth, Iselin; Faleide, Jan Inge; Mjelde, Rolf; Huismans, Ritske

    2017-04-01

    The basement architecture below the Paleozoic sedimentary basins is still not fully understood in the Western Barents Sea region. It has been proposed that the early Devonian Caledonian orogeny has formed structural framework over which major basins have developed lately. However, the geometry of the Caledonian suture zone (its location, orientation and the extent of the deformation front) is still poorly constrained and is ambiguous in the Barents Sea. The crustal evolution of the Barents Sea and the basin-basement interaction is heavily dependent on the spatial extent and orientation of the Caledonian Deformation Front (CDF). In 2014 an active marine seismic experiment was conducted in the Western Barents Sea. One of the goals of the experiment is to discriminate between two existing models for orientations of the CDF: north-south from the potential fields data, and southwest-northeast from seismic data. We also aim to constrain the location of the CDF offshore northern Norway. We present the joint interpretation of collocated newly collected wide-angle seismic data (Ocean Bottom Seismometers) and reprocessing of the reflection seismic dataset (Multi-channel seismics) collected in the mid 1980's, using modern computational techniques. The two seismic methods provide best resolution at different depth ranges, and in our modeling we combine the results from the two methods to constrain the location of the CDF along transect running Northwest-Southeast across the Western Barents Sea.

  20. Tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM (GOM98LINE.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Shapefile showing tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM. This cruise was to the Mississippi Canyon region of the Gulf of...

  1. EQUIPMENTS TO SINGLE PHOTON REGISTRATION. PART 1. FEATURES AND POSSIBILITIES OF MULTI-CHANNEL PHOTODETECTORS WITH INTRINSIC AMPLIFICATION. (REVIEW

    Directory of Open Access Journals (Sweden)

    O. V. Dvornikov

    2012-01-01

    Full Text Available The main types of the modern photo detectors applied to single photon registration are analyzed. It is offered to use silicon photomultipliers for production of multi-channel optoelectronic systems with the single photon resolution.

  2. Multichannel seismic-reflection data acquired off the coast of southern California - Part A 1997, 1998, 1999, and 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Multichannel seismic-reflection (MCS) data were collected in the California Continental Borderland as part of southern California Earthquake Hazards Task. Five data...

  3. Multichannel seismic-reflection data acquired off the coast of southern California - Part A 1997, 1998, 1999, and 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Multichannel seismic-reflection (MCS) data were collected in the California Continental Borderland as part of southern California Earthquake Hazards Task. Five data...

  4. Design and implementation of the optical fiber control and transmission module in multi-channel broadband digital receiver

    Science.gov (United States)

    Zhao, Ying-xiao; Zhang, Yue; Fan, Li-jie; Li, Wei-xing; Chen, Zeng-ping

    2014-09-01

    An optical fiber control and transmission module is designed and realized based on Virtex-7 field programmable gata array (FPGA), which can be applied in multi-channel broadband digital receivers. The module consists of sampling data transfer submodule and multi-channel synchronous sampling control submodule. The sampling data transmission in 4× fiber link channel is realized with the self-defined transfer protocol. The measured maximum data rate is 4.97 Gbyte/s. By connecting coherent clocks to the transmitter and receiver endpoints and using the self-defined transfer protocol, multi-channel sampling control signals transferred in optical fibers can be received synchronously by each analog-to-digital converter (ADC) with high accuracy and strong anti-interference ability. The module designed in this paper has certain reference value in increasing the transmission bandwidth and the synchronous sampling accuracy of multi-channel broadband digital receivers.

  5. Multichannel Seismic Reflection Data - SCAR - Queen Maud Land - 1985-1986, SDLS CD-ROM vol 22

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1985-86 in the Queen Maud Land region, Antarctica, by the Japan National Oil...

  6. Investigation of the effects of summer melt on the calculation of sea ice concentration using active and passive microwave data

    Science.gov (United States)

    Cavalieri, Donald J.; Burns, Barbara A.; Onstott, Robert G.

    1990-01-01

    The effects of ice surface melt on microwave signatures and errors in the calculation of sea ice concentration are examined, using active and passive microwave data sets from the Marginal Ice Zone Experiment aircraft flights in the Fram Strait region. Consideration is given to the possibility of using SAR to supplement passive microwave data to unambiguously discriminate between open water areas and ponded floes. Coincident active multichannel microwave radiometer and SAR measurements of individual floes are used to describe the effects of surface melt on sea ice concentration calculations.

  7. The Role of Multichannel Marketing in Customer Retention and Loyalty: Study in Emerald Bank Customer in Indonesia

    OpenAIRE

    Ambarwati Ambarwati; Djumilah Zain Hadiwidjojo; Achmad Sudiro; Fatchur Rohman

    2015-01-01

    Attention on the relationship between customer retention, customer loyalty, and customer satisfaction that serves as "seed" of customer loyalty highlight the important factors for multichannel management. With the growing trends of people in investing their money in bank for securities need to be responded by the marketing department to create better marketing strategies. The purpose of this study is to examine and explain the effect of a multichannel bank on emerald customers retention   in ...

  8. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  9. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  10. A lossless multichannel bio-signal compression based on low-complexity joint coding scheme for portable medical devices.

    Science.gov (United States)

    Kim, Dong-Sun; Kwon, Jin-San

    2014-09-18

    Research on real-time health systems have received great attention during recent years and the needs of high-quality personal multichannel medical signal compression for personal medical product applications are increasing. The international MPEG-4 audio lossless coding (ALS) standard supports a joint channel-coding scheme for improving compression performance of multichannel signals and it is very efficient compression method for multi-channel biosignals. However, the computational complexity of such a multichannel coding scheme is significantly greater than that of other lossless audio encoders. In this paper, we present a multichannel hardware encoder based on a low-complexity joint-coding technique and shared multiplier scheme for portable devices. A joint-coding decision method and a reference channel selection scheme are modified for a low-complexity joint coder. The proposed joint coding decision method determines the optimized joint-coding operation based on the relationship between the cross correlation of residual signals and the compression ratio. The reference channel selection is designed to select a channel for the entropy coding of the joint coding. The hardware encoder operates at a 40 MHz clock frequency and supports two-channel parallel encoding for the multichannel monitoring system. Experimental results show that the compression ratio increases by 0.06%, whereas the computational complexity decreases by 20.72% compared to the MPEG-4 ALS reference software encoder. In addition, the compression ratio increases by about 11.92%, compared to the single channel based bio-signal lossless data compressor.

  11. An Efficient VLSI Architecture for Multi-Channel Spike Sorting Using a Generalized Hebbian Algorithm.

    Science.gov (United States)

    Chen, Ying-Lun; Hwang, Wen-Jyi; Ke, Chi-En

    2015-08-13

    A novel VLSI architecture for multi-channel online spike sorting is presented in this paper. In the architecture, the spike detection is based on nonlinear energy operator (NEO), and the feature extraction is carried out by the generalized Hebbian algorithm (GHA). To lower the power consumption and area costs of the circuits, all of the channels share the same core for spike detection and feature extraction operations. Each channel has dedicated buffers for storing the detected spikes and the principal components of that channel. The proposed circuit also contains a clock gating system supplying the clock to only the buffers of channels currently using the computation core to further reduce the power consumption. The architecture has been implemented by an application-specific integrated circuit (ASIC) with 90-nm technology. Comparisons to the existing works show that the proposed architecture has lower power consumption and hardware area costs for real-time multi-channel spike detection and feature extraction.

  12. Signal quality estimation with multichannel adaptive filtering in intensive care settings.

    Science.gov (United States)

    Silva, Ikaro; Lee, Joon; Mark, Roger G

    2012-09-01

    A signal quality estimate of a physiological waveform can be an important initial step for automated processing of real-world data. This paper presents a new generic point-by-point signal quality index (SQI) based on adaptive multichannel prediction that does not rely on ad hoc morphological feature extraction from the target waveform. An application of this new SQI to photoplethysmograms (PPG), arterial blood pressure (ABP) measurements, and ECG showed that the SQI is monotonically related to signal-to-noise ratio (simulated by adding white Gaussian noise) and to subjective human quality assessment of 1361 multichannel waveform epochs. A receiver-operating-characteristic (ROC) curve analysis, with the human "bad" quality label as positive and the "good" quality label as negative, yielded areas under the ROC curve of 0.86 (PPG), 0.82 (ABP), and 0.68 (ECG).

  13. An Efficient Method For Multichannel Wireless Mesh Networks With Pulse Coupled Neural Network

    CERN Document Server

    Sobana, S

    2012-01-01

    Multi cast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes, Generally sensor networks and MANETs uses multicast algorithms which are designed to be energy efficient and to achieve optimal route discovery among mobile nodes whereas wireless mesh networks needs to maximize throughput. Here we propose two multicast algorithms: The Level Channel Assignment (LCA) algorithm and the Multi-Channel Multicast (MCM) algorithm to improve the throughput for multichannel sand multi interface mesh networks. The algorithm builds efficient multicast trees by minimizing the number of relay nodes and total hop count distance of the trees. Shortest path computation is a classical combinatorial optimization problem. Neural networks have been used for processing path optimization problem. Pulse Coupled Neural Networks (PCNNS) suffer from high computational cast for very long paths we propose a new PCNN modal called dual source PCNN (DSPCNN) which c...

  14. A multichannel frequency response analyser for impedance spectroscopy on power sources

    Directory of Open Access Journals (Sweden)

    DANIEL J. L. BRETT

    2013-06-01

    Full Text Available A low-cost multi-channel frequency response analyser (FRA has been developed based on a DAQ (data acquisition/LabVIEW interface. The system has been tested for electric and electrochemical impedance measurements. This novel association of hardware and software demonstrated performance comparable to a commercial potentiostat / FRA for passive electric circuits. The software has multichannel capabilities with minimal phase shift for 5 channels when operated below 3 kHz. When applied in active (galvanostatic mode in conjunction with a commercial electronic load (by discharging a lead acid battery at 1.5 A the performance was fit for purpose, providing electrochemical information to characterize the performance of the power source.

  15. CFD-based optimization and design of multi-channel inorganic membrane tubes☆

    Institute of Scientific and Technical Information of China (English)

    Zhao Yang; Jingcai Cheng; Chao Yang; Bin Liang

    2016-01-01

    As a major configuration of membrane elements, multi-channel porous inorganic membrane tubes were studied by means of theoretical analysis and simulation. Configuration optimization of a cylindrical 37-channel porous inorganic membrane tube was studied by increasing membrane filtration area and increasing permeation effi-ciency of inner channels. An optimal ratio of the channel diameter to the inter-channel distance was proposed so as to increase the total membrane filtration area of the membrane tube. The three-dimensional computational fluid dynamics (CFD) simulation was conducted to study the cross-flow permeation flow of pure water in the 37-channel ceramic membrane tube. A model combining Navier–Stokes equation with Darcy's law and the porous jump boundary conditions was applied. The relationship between permeation efficiency and channel locations, and the method for increasing the permeation efficiency of inner channels were proposed. Some novel multi-channel membrane configurations with more permeate side channels were put forward and evaluated.

  16. On the Existence of Synchrostates in Multichannel EEG Signals during Face-perception Tasks

    CERN Document Server

    Jamal, Wasifa; Maharatna, Koushik; Apicella, Fabio; Chronaki, Georgia; Sicca, Federico; Cohen, David; Muratori, Filippo

    2016-01-01

    Phase synchronisation in multichannel EEG is known as the manifestation of functional brain connectivity. Traditional phase synchronisation studies are mostly based on time average synchrony measures hence do not preserve the temporal evolution of the phase difference. Here we propose a new method to show the existence of a small set of unique phase synchronised patterns or "states" in multi-channel EEG recordings, each "state" being stable of the order of ms, from typical and pathological subjects during face perception tasks. The proposed methodology bridges the concepts of EEG microstates and phase synchronisation in time and frequency domain respectively. The analysis is reported for four groups of children including typical, Autism Spectrum Disorder (ASD), low and high anxiety subjects - a total of 44 subjects. In all cases, we observe consistent existence of these states - termed as synchrostates - within specific cognition related frequency bands (beta and gamma bands), though the topographies of these...

  17. Modeling common dynamics in multichannel signals with applications to artifact and background removal in EEG recordings.

    Science.gov (United States)

    De Clercq, Wim; Vanrumste, Bart; Papy, Jean-Michel; Van Paesschen, Wim; Van Huffel, Sabine

    2005-12-01

    Removing artifacts and background electroencephaloraphy (EEG) from multichannel interictal and ictal EEG has become a major research topic in EEG signal processing in recent years. We applied for this purpose a recently developed subspace-based method for modeling the common dynamics in multichannel signals. When the epileptiform activity is common in the majority of channels and the artifacts appear only in a few channels the proposed method can be used to remove the latter. The performance of the method was tested on simulated data for different noise levels. For high noise levels the method was still able to identify the common dynamics. In addition, the method was applied to real life EEG recordings containing interictal and ictal activity contaminated with muscle artifact. The muscle artifacts were removed successfully. For both the synthetic data and the analyzed real life data the results were compared with the results obtained with principal component analysis (PCA). In both cases, the proposed method performed better than PCA.

  18. Removing artifacts and background activity in multichannel electroencephalograms by enhancing common activity.

    Science.gov (United States)

    De Clercq, Wim; Van Paesschen, Wim; Vanrumste, Bart; Papy, J-M; Vergult, Anneleen; Van Huffel, Sabine

    2005-01-01

    Removing artifacts and background EEG from multichannel interictal and ictal EEG has become a major research topic in EEG signal processing in recent years. We applied for this purpose a recently developed subspace-based method for modelling the common dynamics in multichannel signals. When the epileptiform activity is common in the majority of channels and the artifacts appear only in a few channels the proposed method can be used to remove the latter. The performance of the method was tested on simulated data for different noise levels. For high noise levels the method was still able to identify the common dynamics. In addition, the method was applied to a real life EEG recording. Also in this case the muscle artifacts were removed successfully. For both the synthetic data and the analyzed real life data the results were compared with the results obtained with principal component analysis (PCA). In both cases the proposed method performed better than PCA.

  19. A multi-channel high time resolution detector for high content imaging

    CERN Document Server

    Lapington, J S; Miller, G M; Ashton, T J R; Jarron, P; Despeisse, M; Powolny, F; Howorth, J; Milnes, J

    2009-01-01

    Medical imaging has long benefited from advances in photon counting detectors arising from space and particle physics. We describe a microchannel plate-based detector system for high content (multi-parametric) analysis, specifically designed to provide a step change in performance and throughput for measurements in imaged live cells and tissue for the ‘omics’. The detector system integrates multi-channel, high time resolution, photon counting capability into a single miniaturized detector with integrated ASIC electronics, comprising a fast, low power amplifier discriminator and TDC for every channel of the discrete pixel electronic readout, and achieving a pixel density improvement of order two magnitudes compared with current comparable devices. The device combines high performance, easy reconfigurability, and economy within a compact footprint. We present simulations and preliminary measurements in the context of our ultimate goals of 20 ps time resolution with multi-channel parallel analysis (1024 chan...

  20. Multichannel Speech Enhancement Based on Generalized Gamma Prior Distribution with Its Online Adaptive Estimation

    Science.gov (United States)

    Dat, Tran Huy; Takeda, Kazuya; Itakura, Fumitada

    We present a multichannel speech enhancement method based on MAP speech spectral magnitude estimation using a generalized gamma model of speech prior distribution, where the model parameters are adapted from actual noisy speech in a frame-by-frame manner. The utilization of a more general prior distribution with its online adaptive estimation is shown to be effective for speech spectral estimation in noisy environments. Furthermore, the multi-channel information in terms of cross-channel statistics are shown to be useful to better adapt the prior distribution parameters to the actual observation, resulting in better performance of speech enhancement algorithm. We tested the proposed algorithm in an in-car speech database and obtained significant improvements of the speech recognition performance, particularly under non-stationary noise conditions such as music, air-conditioner and open window.

  1. Multichannel active control of random noise in a small reverberant room

    DEFF Research Database (Denmark)

    Laugesen, Søren; Elliott, Stephen J.

    1993-01-01

    An algorithm for multichannel adaptive IIR (infinite impulse response) filtering is presented and applied to the active control of broadband random noise in a small reverberant room. Assuming complete knowledge of the primary noise, the theoretically optimal reductions of acoustic energy...... multichannel FIR (finite impulse response) and IIR filters are then compared for a four-secondary-source, eight-error microphone active control system, and it is found that for the present application FIR filters are sufficient when the primary noise source is a loudspeaker. Some experiments are then presented...... with the primary noise field generated by a panel excited by a loudspeaker in an adjoining room. These results show that far better performances are provided by IIR and FIR filters when the primary source has a lightly damped dynamic behavior which the active controller must model...

  2. Analysis of Magnetic Field Inducted in Brain by Multi-Channel Magnetic Stimulation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Multi-channel magnetic stimulation is an efficient method to improve the conventional magnetic stimulation. A multi-channel magnetic brain stimulator was developed and the distribution of magnetic field was calculated by finite-element analysis software-ANSYS. The results show that when five coils work simultaneously, the area where the magnetic flux density is larger than 0.01 T would expand to almost the whole brain region, and the magnetic stimulation depth would be improved.Experiments were performed on ten subjects (mean age 25) using the stimulator, and the EEG power spectrums before and after stimulation were analyzed. The experimental results show that the beta component of EEG obviously increases after magnetic stimulation, and the effect is more obvious by using more coils simultaneously because of the deeper stimulation.

  3. Investigations of Orchestra Auralizations Using the Multi-Channel Multi-Source Auralization Technique

    DEFF Research Database (Denmark)

    Vigeant, Michelle; Wang, Lily M.; Rindel, Jens Holger

    2008-01-01

    ) a surface source, and (c) single-channel multi-source method. Results show that the multi-source auralizations were rated to be more realistic than the surface source ones and to have larger source width than the single omni-directional source auralizations. No significant differences were found between...... a multi-channel multi-source auralization technique, involving individual five-channel anechoic recordings of each instrumental part of two symphonies. In the first study, these auralizations were subjectively compared to orchestra auralizations made using (a) a single omni-directional source, (b......, subjects could only discern differences between the orchestra configurations with the five-channel multi-source auralizations. Overall, the multi-source auralization technique was found to be an effective method for creating realistic orchestra auralizations, but using multichannel anechoic recordings...

  4. Reaction Mechanism Investigation Using Vibrational Mode Analysis for the Multichannel Reaction of CH3O + CO

    Institute of Scientific and Technical Information of China (English)

    ZHOU,Zheng-Yu(周正宇); CHENG,Xue-Li(程学礼); GUO,Li(郭丽)

    2002-01-01

    On the basis of the computed results got by the Gaussian 94 package at B3LYP/6-311 + +G * * level, the reaction mechanism of CH3O radical with CO has been investigated thoroughly via the vibrational model analysis. And the relationships among the reactants, eight transition states, four intermediates and various products involved this multichannel reaction are elucidated. The vibrational mode analysis shows that the reaction mechanism is reliable.

  5. IPOD-USGS multichannel seismic reflection profile from Cape Hatteras to the Mid-Atlantic Ridge

    Science.gov (United States)

    Grow, John A.; Markl, Rudi G.

    1977-01-01

    A 3,400-km-long multichannel seismic-reflection profile from Cape Hatteras to the Mid-Atlantic Ridge was acquired commercially under contract to the National Science Foundation and the U.S. Geological Survey. These data show evidence for massive erosion of the continental slope, diapirs at the base of the continental slope, and mantle reflections beneath the Hatteras Abyssal Plain.

  6. On multichannel solutions of nonlinear Schr\\"{o}dinger equations: algorithm, analysis and numerical explorations

    CERN Document Server

    Soffer, Avy

    2014-01-01

    We apply the method of modulation equations to numerically solve the NLS with multichannel dynamics, given by a trapped localized state and radiation. This approach employs the modulation theory of Soffer-Weinstein, which gives a system of ODE's coupled to the radiation term, which is valid for all times. We comment on the differences of this method from the well-known method of collective coordinates.

  7. Minimizing the Message Waiting Time in Single-Hop Multichannel Systems

    OpenAIRE

    Martelli, Francesca; Bonuccelli, Maurizio

    2010-01-01

    In this paper, we examine the problem of packet scheduling in a single-hop multichannel systems, with the goal of minimizing the average message waiting time. Such an objective function represents the delay incurred by the users before receiving the desired data. We show that the problem of finding a schedule with minimum message waiting time, is NP-complete, by means of polynomial time reduction of the time table design problem to our problem. We present also several heuristics which result ...

  8. Multi-channel high-resolution terahertz spectrometer for analytical studies

    Science.gov (United States)

    Vaks, V.; Domracheva, E.; Pripolzin, S.; Chernyaeva, M.; Yablokov, A.

    2016-12-01

    A method of multi-channel THz spectroscopy and a sample device that embodies the method were developed and described by the authors. The device has two independent THz radiation sources and a single receiving module. The novel method allows detecting preliminary and short-living chemical compounds and therefore to studychemical reaction dynamics. This has been shown by a series of test experiments. The method can be applied to researches in Physics, Chemistry, Astronomy, Medicine, and Biology.

  9. 75 FR 59645 - Radio Broadcast Services and Multichannel Video and Cable Television Service; Clarification...

    Science.gov (United States)

    2010-09-28

    ...The Federal Communications Commission has published a number of requirements related to Radio Broadcast Services and Multichannel Video and Cable Television Service, which were determined to contain information collection requirements that were subject to OMB review. After further review, we have found OMB approval is not required. This document intends to provide clarification that these rules are effective and that it has been determined that these provisions are not subject to OMB review.

  10. A Multichannel Gray Level Co-Occurrence Matrix for Multi/Hyperspectral Image Texture Representation

    Directory of Open Access Journals (Sweden)

    Xin Huang

    2014-09-01

    Full Text Available This study proposes a novel method for multichannel image gray level co-occurrence matrix (GLCM texture representation. It is well known that the standard procedure for the automatic extraction of GLCM textures is based on a mono-spectral image. In real applications, however, the GLCM texture feature extraction always refers to multi/hyperspectral images. The widely used strategy to deal with this issue is to calculate the GLCM from the first principal component or the panchromatic band, which do not include all the useful information. Accordingly, in this study, we propose to represent the multichannel textures for multi/hyperspectral imagery by the use of: (1 clustering algorithms; and (2 sparse representation, respectively. In this way, the multi/hyperspectral images can be described using a series of quantized codes or dictionaries, which are more suitable for multichannel texture representation than the traditional methods. Specifically, K-means and fuzzy c-means methods are adopted to generate the codes of an image from the clustering point of view, while a sparse dictionary learning method based on two coding rules is proposed to produce the texture primitives. The proposed multichannel GLCM textural extraction methods were evaluated with four multi/hyperspectral datasets: GeoEye-1 and QuickBird multispectral images of the city of Wuhan, the well-known AVIRIS hyperspectral dataset from the Indian Pines test site, and the HYDICE airborne hyperspectral dataset from the Washington DC Mall. The results show that both the clustering-based and sparsity-based GLCM textures outperform the traditional method (extraction based on the first principal component in terms of classification accuracies in all the experiments.

  11. [Use of multichannel programmed electrostimulation for the rehabilitation of patients with multiple sclerosis].

    Science.gov (United States)

    Popova, N F; Shagaev, A S

    2009-01-01

    Ninety-eight patients with definite multiple sclerosis (MS) have been examined. An effect of functional multichannel programmed electrostimulation (FMPES) on the restoration of balance and biomechanics of walking of patients with different types of MS and severity of neurological deficit was estimated. The effectiveness was measured with stabilometric analysis. The method was efficient in patients with mild and moderate degree of neurological deficit severity. Recommendations on the use of FMPES for patients with different disease severity are formulated.

  12. Feasibility of Interfacing a Microcomputer with a Multichannel Analyzer to Perform Gamma Ray Spectroscopy.

    Science.gov (United States)

    1981-03-01

    Single Board Computer , model SBC 80/20 manufacted by Intel Corporation (Ref 2). The single board computer ccntains...available but is only used to regain control of the system when a program malfunctions. The most important feature of the single board computer is...because there are 41 output lines from the multichannel analyzer and 24 input lines to the single board computer . One reset and two interupt

  13. Multichannel system based on a high sensitivity superconductive sensor for magnetoencephalography.

    Science.gov (United States)

    Rombetto, Sara; Granata, Carmine; Vettoliere, Antonio; Russo, Maurizio

    2014-07-08

    We developed a multichannel system based on superconducting quantum interference devices (SQUIDs) for magnetoencephalography measurements. Our system consists of 163 fully-integrated SQUID magnetometers, 154 channels and 9 references, and all of the operations are performed inside a magnetically-shielded room. The system exhibits a magnetic field noise spectral density of approximatively 5 fT/Hz(1=2). The presented magnetoencephalography is the first system working in a clinical environment in Italy.

  14. Optimal multi-sensor Kalman smoothing fusion for discrete multichannel ARMA signals

    Institute of Scientific and Technical Information of China (English)

    Shuli SUN

    2005-01-01

    Based on the multi-sensor optimal information fusion criterion weighted by matrices in the linear minimum variance sense,using white noise estimators,an optimal fusion distributed Kalman smoother is given for discrete multi-channel ARMA (autoregressive moving average) signals.The smoothing error cross-covariance matrices between any two sensors are given for measurement noises.Furthermore,the fusion smoother gives higher precision than any local smoother does.

  15. New Environment-Sensitive Multichannel DNA Fluorescent Label for Investigation of the Protein-DNA Interactions

    OpenAIRE

    Kuznetsova, Alexandra A.; Kuznetsov, Nikita A.; Vorobjev, Yuri N.; Barthes, Nicolas P. F.; Benoît Y Michel; Alain Burger; Fedorova, Olga S.

    2014-01-01

    Here, we report the study of a new multichannel DNA fluorescent base analogue 3-hydroxychromone (3HC) to evaluate its suitability as a fluorescent reporter probe of structural transitions during protein-DNA interactions and its comparison with the current commercially available 2-aminopurine (aPu), pyrrolocytosine (Cpy) and 1,3-diaza-2-oxophenoxazine (tCO). For this purpose, fluorescent base analogues were incorporated into DNA helix on the opposite or on the 5'-side of the damaged nucleoside...

  16. The interface design for the USB-based multi-channel analyzer

    CERN Document Server

    Sun Guang Cai

    2002-01-01

    A new style interface circuit design for multi-channel analyzer is introduced, which takes the advantages of Universal Serial Bus to communicate with computer and gets the merit of high universality and Plug and Play. The interface circuit also uses dual-port SRAM and high-speed MCU to store and translate data, which could solve the bottleneck problem existing in data translation from the interface to computer

  17. Development of a gated optical multichannel analyser for laser-plasma spectroscopy

    OpenAIRE

    Corcoran, Richard

    1990-01-01

    An Optical Multichannel Analyser (OMA) has been developed for the detection of radiation from laser-produced plasmas (LPPs). The system is based on a gated image - intensified photodiode array (PDA) Software for the control of, and data acquisition from, the OMA system has been developed. A high resolution (10ns) delay generator was also designed and constructed to permit timeresolved. optical spectroscopy. The system has been tested and operated with a laser plasma source m...

  18. Atmospheric water distribution in cyclones as seen with Scanning Multichannel Microwave Radiometers (SMMR)

    Science.gov (United States)

    Katsaros, K. B.; Mcmurdie, L. A.

    1983-01-01

    Passive microwave measurements are used to study the distribution of atmospheric water in midlatitude cyclones. The integrated water vapor, integrated liquid water, and rainfall rate are deduced from the brightness temperatures at microwave frequencies measured by the Scanning Multichannel Microwave Radiometer (SMRR) flown on both the Seasat and Nimbus 7 satellites. The practical application of locating fronts by the cyclone moisture pattern over oceans is shown, and the relationship between the quantity of coastal rainfall and atmospheric water content is explored.

  19. High dynamic range multi-channel cross-correlator for single-shot temporal contrast measurement

    Science.gov (United States)

    Kon, A.; Nishiuchi, M.; Kiriyama, H.; Ogura, K.; Mori, M.; Sakaki, H.; Kando, M.; Kondo, K.

    2016-05-01

    We have developed a multi-channel cross-correlator for high dynamic range (>1010), single-shot temporal contrast measurements. The correlator utilizes a third-order crosscorrelation technique and has a reference channel, to be normalized by the measured peak intensity, and four independent optical delay lines. The measurement results of the shot-to-shot temporal contrast clearly show the intensity fluctuations of short pre-pulses at -4.5 ps and -26 ps before main pulse.

  20. Lead generation strategy as a multichannel mechanism of growth of a modern enterprise

    OpenAIRE

    Łukowski Wojciech; Świeczak Witold

    2016-01-01

    Lead generation strategy describes the marketing process of involvement and capture of interest in a product or service which is aimed at developing sales plans and, as a consequence, soliciting new clients. Lead generation is becoming an increasingly popular demand-generating strategy, which – through its multichannelled dissemination of the generated message – gives it a much greater reach. Lead generation assists organisations in achieving a greater brand awareness, building relationships ...

  1. Joint routing, scheduling, and power control for multichannel wireless sensor networks with physical interference

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Reliability and real-time requirements bring new challenges to the energy-constrained wireless sensor networks, especially to the industrial wireless sensor networks. Meanwhile, the capacity of wireless sensor networks can be substantially increased by operating on multiple nonoverlapping channels. In this context, new routing, scheduling, and power control algorithms are required to achieve reliable and real-time communications and to fully utilize the increased bandwidth in multichannel wireless sensor ne...

  2. An integrated analog O/E/O link for multi-channel laser neurons

    Energy Technology Data Exchange (ETDEWEB)

    Nahmias, Mitchell A., E-mail: mnahmias@princeton.edu; Tait, Alexander N.; Tolias, Leonidas; Chang, Matthew P.; Ferreira de Lima, Thomas; Shastri, Bhavin J.; Prucnal, Paul R. [Electrical Engineering Department, Princeton University, 41 Olden St, Princeton, New Jersey 08540 (United States)

    2016-04-11

    We demonstrate an analog O/E/O electronic link to allow integrated laser neurons to accept many distinguishable, high bandwidth input signals simultaneously. This device utilizes wavelength division multiplexing to achieve multi-channel fan-in, a photodetector to sum signals together, and a laser cavity to perform a nonlinear operation. Its speed outpaces accelerated-time neuromorphic electronics, and it represents a viable direction towards scalable networking approaches.

  3. High performance multi-channel MOSFET on InGaAs for RF amplifiers

    Science.gov (United States)

    Adhikari, Manoj Singh; Singh, Yashvir

    2017-02-01

    In this paper, we propose a multi-channel MOSFET (MC-MOSFET) on In0.53Ga0.47As for the first time by utilising trenches in the conventional planar MOSFET (CP-MOSFET) for RF amplifier applications. The proposed multi-channel MOSFET (MC-MOSFET) has two vertical-gates placed in trenches creating multiple channels in p-body for parallel conduction of drain current. High-k Al2O3 having thickness of 2 nm is used as gate dielectric in the proposed device. The TaN gate electrodes are placed in two different trenches in the p-type InGaAs layer where multiple n-channels are formed. Simultaneous conduction from multiple channels enhances the drain current (ID) and gives higher transconductance (gm) leading to improvement in overall frequency response. Two-dimensional (2D) numerical simulations of both MC-MOSFET and CP-MOSFET are performed by using ATLAS device simulator and their different performance parameters are compared. The proposed multi-channel structure provides 6.79 times higher ID, 5.57 times improvement in gm, 2.5 times increase in unity current gain (ft), 15.85% higher unilateral power gain (fmax) and suppress the short-channel effects (SCEs) as compared with the CP-MOSFET.

  4. Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network

    Directory of Open Access Journals (Sweden)

    Kai Lin

    2016-07-01

    Full Text Available With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC. The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods.

  5. An interactive visualization tool for multi-channel confocal microscopy data in neurobiology research

    KAUST Repository

    Yong Wan,

    2009-11-01

    Confocal microscopy is widely used in neurobiology for studying the three-dimensional structure of the nervous system. Confocal image data are often multi-channel, with each channel resulting from a different fluorescent dye or fluorescent protein; one channel may have dense data, while another has sparse; and there are often structures at several spatial scales: subneuronal domains, neurons, and large groups of neurons (brain regions). Even qualitative analysis can therefore require visualization using techniques and parameters fine-tuned to a particular dataset. Despite the plethora of volume rendering techniques that have been available for many years, the techniques standardly used in neurobiological research are somewhat rudimentary, such as looking at image slices or maximal intensity projections. Thus there is a real demand from neurobiologists, and biologists in general, for a flexible visualization tool that allows interactive visualization of multi-channel confocal data, with rapid fine-tuning of parameters to reveal the three-dimensional relationships of structures of interest. Together with neurobiologists, we have designed such a tool, choosing visualization methods to suit the characteristics of confocal data and a typical biologist\\'s workflow. We use interactive volume rendering with intuitive settings for multidimensional transfer functions, multiple render modes and multi-views for multi-channel volume data, and embedding of polygon data into volume data for rendering and editing. As an example, we apply this tool to visualize confocal microscopy datasets of the developing zebrafish visual system.

  6. Automatic detection and classification of sleep stages by multichannel EEG signal modeling.

    Science.gov (United States)

    Zhovna, Inna; Shallom, Ilan D

    2008-01-01

    In this paper a novel method for automatic detection and classification of sleep stages using a multichannel electroencephalography (EEG) is presented. Understanding the sleep mechanism is vital for diagnosis and treatment of sleep disorders. The EEG is one of the most important tools of studying and diagnosing sleep disorders. EEG signals waveforms activity interpretation is performed by visual analysis (a very difficult procedure). This research aim is to ease the difficulties involved in the existing manual process of EEG interpretation by proposing an automatic sleep stage detection and classification system. The suggested method based on Multichannel Auto Regressive (MAR) model. The multichannel analysis approach incorporates the cross correlation information existing between different EEG signals. In the training phase, we used the vector quantization (VQ) algorithm, Linde-Buzo-Gray (LBG) and sleep stage definition, by estimation of probability mass functions (pmf) per every sleep stage using Generalized Log Likelihood Ratio (GLLR) distortion. The classification phase was performed using Kullback-Leibler (KL) divergence. The results of this research are promising with classification accuracy rate of 93.2%. The results encourage continuation of this research in the sleep field and in other biomedical signals applications.

  7. Multichannel control systems for the attenuation of interior road noise in vehicles

    Science.gov (United States)

    Cheer, Jordan; Elliott, Stephen J.

    2015-08-01

    This paper considers the active control of road noise in vehicles, using either multichannel feedback control, with both headrest and floor positioned microphones providing feedback error signals, or multichannel feedforward control, in which reference signals are provided by the microphones on the vehicle floor and error signals are provided by the microphones mounted on the headrests. The formulation of these control problems is shown to be similar if the constraints of robust stability, limited disturbance enhancement and open-loop stability are imposed. A novel formulation is presented for disturbance enhancement in multichannel systems, which limits the maximum enhancement of each individual error signal. The performance of these two systems is predicted using plant responses and disturbance signals measured in a small city car. The reduction in the sum of the squared pressure signals at the four error microphones for both systems is found to be up to 8 dB at low frequencies and 3 dB on average, where the sound level is particularly high from 80 to 180 Hz. The performance of both systems is found to be robust to measured variations in the plant responses. The enhancements in the disturbance at higher frequencies are smaller for the feedback controller than for the feedforward controller, although the performance of the feedback controller is more significantly reduced by the introduction of additional delay in the plant response.

  8. Single-channel and multi-channel orthogonal matching pursuit for seismic trace decomposition

    Science.gov (United States)

    Feng, Xuan; Zhang, Xuebing; Liu, Cai; Lu, Qi

    2017-02-01

    The conventional matching pursuit (MP) algorithm can decompose a 1D signal into a set of wavelet atoms adaptively. As to reflection seismic data, some applicable algorithms based on the MP decomposition has been developed, such as single-channel matching pursuit (SCMP) and multi-channel matching pursuit (MCMP). However, these algorithms cannot always select the optimal atoms, which results in less meaningful decompositions. To overcome this limitation, we introduce the idea of orthogonal matching pursuit into a multi-channel decomposition scheme, which we refer to as the multi-channel orthogonal matching pursuit (MCOMP). Each iteration of the proposed MCOMP might extract a more reasonable atom among a redundant Morlet wavelet dictionary, like the MCMP decomposition does, and estimate the corresponding amplitude more accurately by solving a least-squares problem. In order to correspond to SCMP, we also simplified the MCOMP decomposition to single-channel orthogonal matching pursuit (SCOMP) for decompositions of an individual seismic trace. We tested the proposed SCOMP algorithm on a synthetic signal and a field seismic trace. Then a field marine dataset example showed relative high resolution of the proposed MCOMP method with applications to the detection of low-frequency anomalies. These application examples all demonstrate more meaningful decomposition results and relative high convergence speed of the proposed algorithms.

  9. Active listening room compensation for massive multichannel sound reproduction systems using wave-domain adaptive filtering.

    Science.gov (United States)

    Spors, Sascha; Buchner, Herbert; Rabenstein, Rudolf; Herbordt, Wolfgang

    2007-07-01

    The acoustic theory for multichannel sound reproduction systems usually assumes free-field conditions for the listening environment. However, their performance in real-world listening environments may be impaired by reflections at the walls. This impairment can be reduced by suitable compensation measures. For systems with many channels, active compensation is an option, since the compensating waves can be created by the reproduction loudspeakers. Due to the time-varying nature of room acoustics, the compensation signals have to be determined by an adaptive system. The problems associated with the successful operation of multichannel adaptive systems are addressed in this contribution. First, a method for decoupling the adaptation problem is introduced. It is based on a generalized singular value decomposition and is called eigenspace adaptive filtering. Unfortunately, it cannot be implemented in its pure form, since the continuous adaptation of the generalized singular value decomposition matrices to the variable room acoustics is numerically very demanding. However, a combination of this mathematical technique with the physical description of wave propagation yields a realizable multichannel adaptation method with good decoupling properties. It is called wave domain adaptive filtering and is discussed here in the context of wave field synthesis.

  10. Feature Extraction for the Analysis of Multi-Channel EEG Signals Using Hilbert- Huang Technique

    Directory of Open Access Journals (Sweden)

    Mahipal Singh

    2016-02-01

    Full Text Available This research article seeks to propose a Hilbert-Huang transform (HHT based novel feature extraction approach for the analysis of multi-channel EEG signals using its local time scale features. The applicability of this recently developed HHT based new features has been investigated in the analysis of multi-channel EEG signals for classifying a small set of non-motor cognitive task. HHT is combination of multivariate empirical mode decomposition (MEMD and Hilbert transform (HT. At the first stage, multi-channel EEG signals (6 channels per trial per task per subject corresponding to a small set of nonmotor mental task were decomposed by using MEMD algorithm. This gives rise to adaptive i.e. data driven decomposition of the data into twelve mono component oscillatory modes known as intrinsic mode functions (IMFs and one residue function. These generated intrinsic mode functions (IMFs are multivariate i.e. mode aligned and narrowband. From the generated IMFs, most sensitive IMF has been chosen by analysing their power spectrum. Since IMFs are amplitude and frequency modulated, the chosen IMF has been analysed through their instantaneous amplitude (IA and instantaneous frequency (IF i.e. local features extracted by applying Hilbert transform on them. Finally, the discriminatory power of these local features has been investigated through statistical significance test using paired t-test. The analysis results clearly support the potential of these local features for classifying different cognitive task in EEG based Brain –Computer Interface (BCI system.

  11. The algorithmic complexity of multichannel EEGs is sensitive to changes in behavior.

    Science.gov (United States)

    Watanabe, T A A; Cellucci, C J; Kohegyi, E; Bashore, T R; Josiassen, R C; Greenbaun, N N; Rapp, P E

    2003-01-01

    Symbolic measures of complexity provide a quantitative characterization of the sequential structure of symbol sequences. Promising results from the application of these methods to the analysis of electroencephalographic (EEG) and event-related brain potential (ERP) activity have been reported. Symbolic measures used thus far have two limitations, however. First, because the value of complexity increases with the length of the message, it is difficult to compare signals of different epoch lengths. Second, these symbolic measures do not generalize easily to the multichannel case. We address these issues in studies in which both single and multichannel EEGs were analyzed using measures of signal complexity and algorithmic redundancy, the latter being defined as a sequence-sensitive generalization of Shannon's redundancy. Using a binary partition of EEG activity about the median, redundancy was shown to be insensitive to the size of the data set while being sensitive to changes in the subject's behavioral state (eyes open vs. eyes closed). The covariance complexity, calculated from the singular value spectrum of a multichannel signal, was also found to be sensitive to changes in behavioral state. Statistical separations between the eyes open and eyes closed conditions were found to decrease following removal of the 8- to 12-Hz content in the EEG, but still remained statistically significant. Use of symbolic measures in multivariate signal classification is described.

  12. RAC-Multi: Reader Anti-Collision Algorithm for Multichannel Mobile RFID Networks

    Directory of Open Access Journals (Sweden)

    Kwangcheol Shin

    2009-12-01

    Full Text Available At present, RFID is installed on mobile devices such as mobile phones or PDAs and provides a means to obtain information about objects equipped with an RFID tag over a multi-channeled telecommunication networks. To use mobile RFIDs, reader collision problems should be addressed given that readers are continuously moving. Moreover, in a multichannel environment for mobile RFIDs, interference between adjacent channels should be considered. This work first defines a new concept of a reader collision problem between adjacent channels and then suggests a novel reader anti-collision algorithm for RFID readers that use multiple channels. To avoid interference with adjacent channels, the suggested algorithm separates data channels into odd and even numbered channels and allocates odd-numbered channels first to readers. It also sets an unused channel between the control channel and data channels to ensure that control messages and the signal of the adjacent channel experience no interference. Experimental results show that suggested algorithm shows throughput improvements ranging from 29% to 46% for tag identifications compared to the GENTLE reader anti-collision algorithm for multichannel RFID networks.

  13. Concept of multichannel spin-resolving electron analyzer based on Mott scattering

    CERN Document Server

    Strocov, Vladimir N; Dil, J Hugo

    2014-01-01

    Concept of a multichannel electron spin detector based on optical imaging principles and Mott scattering (iMott) is presented. A multichannel electron image produced by standard angle-resolving (photo) electron analyzer or microscope is re-imaged by an electrostatic lens at an accelerating voltage of 40 keV onto the Au target. Quasi-elastic electrons bearing spin asymmetry of the Mott scattering are imaged by magnetic lenses onto position-sensitive electron CCDs whose differential signals yield the multichannel spin asymmetry image. Fundamental advantages of this concept include acceptance of inherently divergent electron sources from the electron analyzer or microscope focal plane as well as small aberrations achieved by virtue of high accelerating voltages, as demonstrated by extensive ray-tracing analysis. The efficiency gain compared to the single-channel Mott detector can be a factor of 1.5e4 and above, opening new prospects of spin-resolved spectroscopies in application not only to standard bulk and sur...

  14. Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces.

    Science.gov (United States)

    Qian, Jing-Guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

    2015-11-01

    [Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern.

  15. Parallel encryption for multi-channel images based on an optical joint transform correlator

    Science.gov (United States)

    Liu, Jie; Bai, Tingzhu; Shen, Xueju; Dou, Shuaifeng; Lin, Chao; Cai, Jianjun

    2017-08-01

    We propose an optical encryption method allowing the parallel encryption for multi-channel images based on a joint transform correlator (JTC). Distinguished from the conventional multi-image encryption methods, our proposed cryptosystem can encrypt multi-channel images simultaneously into a single ciphertext, which also can be used to recover arbitrary original images with corresponding keys. This method can achieve the compressed storage of ciphertext. In order to avoid the cross talk between multi-channel images, we restrict the respective joint power spectrum (JPS) into a specific area with optimized phase masks and split the multiple JPS by controlling the position of single JPS using the linear phase shifts. All of these operations are realized by optimizing and designing the phase masks which can be flexibly reconfigured on the spatial light modulator (SLM), leading to a feasible optical implementation with no increase of optical hardware and complexity. Computer simulations provide the validation for it. Experimental implementation is performed in a JTC-based cryptosystem to further verify the feasibility of our proposed method.

  16. Load-Adaptive Practical Multi-Channel Communications in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Choong Seon Hong

    2010-09-01

    Full Text Available In recent years, a significant number of sensor node prototypes have been designed that provide communications in multiple channels. This multi-channel feature can be effectively exploited to increase the overall capacity and performance of wireless sensor networks (WSNs. In this paper, we present a multi-channel communications system for WSNs that is referred to as load-adaptive practical multi-channel communications (LPMC. LPMC estimates the active load of a channel at the sink since it has a more comprehensive view of the network behavior, and dynamically adds or removes channels based on the estimated load. LPMC updates the routing path to balance the loads of the channels. The nodes in a path use the same channel; therefore, they do not need to switch channels to receive or forward packets. LPMC has been evaluated through extensive simulations, and the results demonstrate that it can effectively increase the delivery ratio, network throughput, and channel utilization, and that it can decrease the end-to-end delay and energy consumption.

  17. Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network.

    Science.gov (United States)

    Lin, Kai; Wang, Di; Hu, Long

    2016-07-01

    With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC). The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S) evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods.

  18. CR-MAC: A Multichannel MAC Protocol for Cognitive Radio AD HOC Networks

    Directory of Open Access Journals (Sweden)

    S. M. Kamruzzaman

    2010-09-01

    Full Text Available This paper proposes a cross-layer based cognitive radio multichannel medium access control (MACprotocol with TDMA, which integrate the spectrum sensing at physical (PHY layer and the packetscheduling at MAC layer, for the ad hoc wireless networks. The IEEE 802.11 standard allows for the useof multiple channels available at the PHY layer, but its MAC protocol is designed only for a singlechannel. A single channel MAC protocol does not work well in a multichannel environment, because ofthe multichannel hidden terminal problem. Our proposed protocol enables secondary users (SUs toutilize multiple channels by switching channels dynamically, thus increasing network throughput. In ourproposed protocol, each SU is equipped with only one spectrum agile transceiver, but solves themultichannel hidden terminal problem using temporal synchronization. The proposed cognitive radioMAC (CR-MAC protocol allows SUs to identify and use the unused frequency spectrum in a way thatconstrains the level of interference to the primary users (PUs. Our scheme improves network throughputsignificantly, especially when the network is highly congested. The simulation results show that ourproposed CR-MAC protocol successfully exploits multiple channels and significantly improves networkperformance by using the licensed spectrum band opportunistically and protects PUs from interference,even in hidden terminal situations.

  19. Estimating VDT Mental Fatigue Using Multichannel Linear Descriptors and KPCA-HMM

    Directory of Open Access Journals (Sweden)

    Yi Ouyang

    2008-04-01

    Full Text Available The impacts of prolonged visual display terminal (VDT work on central nervous system and autonomic nervous system are observed and analyzed based on electroencephalogram (EEG and heart rate variability (HRV. Power spectral indices of HRV, the P300 components based on visual oddball task, and multichannel linear descriptors of EEG are combined to estimate the change of mental fatigue. The results show that long-term VDT work induces the mental fatigue. The power spectral of HRV, the P300 components, and multichannel linear descriptors of EEG are correlated with mental fatigue level. The cognitive information processing would come down after long-term VDT work. Moreover, the multichannel linear descriptors of EEG can effectively reflect the changes of θ, α, and β waves and may be used as the indices of the mental fatigue level. The kernel principal component analysis (KPCA and hidden Markov model (HMM are combined to differentiate two mental fatigue states. The investigation suggests that the joint KPCA-HMM method can effectively reduce the dimensions of the feature vectors, accelerate the classification speed, and improve the accuracy of mental fatigue to achieve the maximum 88%. Hence KPCA-HMM could be a promising model for the estimation of mental fatigue.

  20. A multichannel smartphone optical biosensor for high-throughput point-of-care diagnostics.

    Science.gov (United States)

    Wang, Li-Ju; Chang, Yu-Chung; Sun, Rongrong; Li, Lei

    2017-01-15

    Current reported smartphone spectrometers are only used to monitor or measure one sample at a time. For the first time, we demonstrate a multichannel smartphone spectrometer (MSS) as an optical biosensor that can simultaneously optical sense multiple samples. In this work, we developed a novel method to achieve the multichannel optical spectral sensing with nanometer resolution on a smartphone. A 3D printed cradle held the smartphone integrated with optical components. This optical sensor performed accurate and reliable spectral measurements by optical intensity changes at specific wavelength or optical spectral shifts. A custom smartphone multi-view App was developed to control the optical sensing parameters and to align each sample to the corresponding channel. The captured images were converted to the transmission spectra in the visible wavelength range from 400nm to 700nm with the high resolution of 0.2521nm per pixel. We validated the performance of this MSS via measuring the concentrations of protein and immunoassaying a type of human cancer biomarker. Compared to the standard laboratory instrument, the results sufficiently showed that this MSS can achieve the comparative analysis detection limits, accuracy and sensitivity. We envision that this multichannel smartphone optical biosensor will be useful in high-throughput point-of-care diagnostics with its minimizing size, light weight, low cost and data transmission function. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Estimating VDT Mental Fatigue Using Multichannel Linear Descriptors and KPCA-HMM

    Science.gov (United States)

    Zhang, Chong; Zheng, Chongxun; Yu, Xiaolin; Ouyang, Yi

    2008-12-01

    The impacts of prolonged visual display terminal (VDT) work on central nervous system and autonomic nervous system are observed and analyzed based on electroencephalogram (EEG) and heart rate variability (HRV). Power spectral indices of HRV, the P300 components based on visual oddball task, and multichannel linear descriptors of EEG are combined to estimate the change of mental fatigue. The results show that long-term VDT work induces the mental fatigue. The power spectral of HRV, the P300 components, and multichannel linear descriptors of EEG are correlated with mental fatigue level. The cognitive information processing would come down after long-term VDT work. Moreover, the multichannel linear descriptors of EEG can effectively reflect the changes of θ, α, and β waves and may be used as the indices of the mental fatigue level. The kernel principal component analysis (KPCA) and hidden Markov model (HMM) are combined to differentiate two mental fatigue states. The investigation suggests that the joint KPCA-HMM method can effectively reduce the dimensions of the feature vectors, accelerate the classification speed, and improve the accuracy of mental fatigue to achieve the maximum 88%. Hence KPCA-HMM could be a promising model for the estimation of mental fatigue.

  2. Concept of a multichannel spin-resolving electron analyzer based on Mott scattering

    Science.gov (United States)

    Strocov, Vladimir N.; Petrov, Vladimir N.; Dil, J. Hugo

    2015-01-01

    The concept of a multichannel electron spin detector based on optical imaging principles and Mott scattering (iMott) is presented. A multichannel electron image produced by a standard angle-resolving (photo) electron analyzer or microscope is re-imaged by an electrostatic lens at an accelerating voltage of 40 kV onto the Au target. Quasi-elastic electrons bearing spin asymmetry of the Mott scattering are imaged by magnetic lenses onto position-sensitive electron CCDs whose differential signals yield the multichannel spin asymmetry image. Fundamental advantages of this concept include acceptance of inherently divergent electron sources from the electron analyzer or microscope focal plane as well as small aberrations achieved by virtue of high accelerating voltages, as demonstrated by extensive ray-tracing analysis. The efficiency gain compared with the single-channel Mott detector can be a factor of more than 104 which opens new prospects of spin-resolved spectroscopies in application not only to standard bulk and surface systems (Rashba effect, topological insulators, etc.) but also to buried heterostructures. The simultaneous spin detection combined with fast CCD readout enables efficient use of the iMott detectors at X-ray free-electron laser facilities. PMID:25931087

  3. White sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, R.A. [Lomonosov Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics]|[Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.]|[Russian Academy of Sciences, Moscow (Russian Federation). Shirshov Inst. of Oceanology; Kalmykov, S.N.; Lisitzin, A.P. [Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.

    2004-07-01

    The aim of the present work is to estimate potential sources and chronology of pollution of the White Sea (Russia) by artificial radionuclides. White Sea is semi-closed water body connected with Barents Sea by a narrow strait. Thus, pollution of White Sea may be caused by highly polluted Barents waters and river (mainly Northern Dvina) run-off. This is the first detailed investigation of radioactivity of White Sea sediment records. (orig.)

  4. Adaptive spatio-temporal filtering of disturbed ECGs: a multi-channel approach to heartbeat detection in smart clothing.

    Science.gov (United States)

    Wiklund, Urban; Karlsson, Marcus; Ostlund, Nils; Berglin, Lena; Lindecrantz, Kaj; Karlsson, Stefan; Sandsjö, Leif

    2007-06-01

    Intermittent disturbances are common in ECG signals recorded with smart clothing: this is mainly because of displacement of the electrodes over the skin. We evaluated a novel adaptive method for spatio-temporal filtering for heartbeat detection in noisy multi-channel ECGs including short signal interruptions in single channels. Using multi-channel database recordings (12-channel ECGs from 10 healthy subjects), the results showed that multi-channel spatio-temporal filtering outperformed regular independent component analysis. We also recorded seven channels of ECG using a T-shirt with textile electrodes. Ten healthy subjects performed different sequences during a 10-min recording: resting, standing, flexing breast muscles, walking and pushups. Using adaptive multi-channel filtering, the sensitivity and precision was above 97% in nine subjects. Adaptive multi-channel spatio-temporal filtering can be used to detect heartbeats in ECGs with high noise levels. One application is heartbeat detection in noisy ECG recordings obtained by integrated textile electrodes in smart clothing.

  5. The Role of Multichannel Marketing in Customer Retention and Loyalty: Study in Emerald Bank Customer in Indonesia

    Directory of Open Access Journals (Sweden)

    Ambarwati Ambarwati

    2015-09-01

    Full Text Available Attention on the relationship between customer retention, customer loyalty, and customer satisfaction that serves as "seed" of customer loyalty highlight the important factors for multichannel management. With the growing trends of people in investing their money in bank for securities need to be responded by the marketing department to create better marketing strategies. The purpose of this study is to examine and explain the effect of a multichannel bank on emerald customers retention   in one of the largest SOE bank in Indonesia, in the city of Surabaya, BNI (Bank Negara Indonesia toward customer  satisfaction, loyalty and customer  retention. This study develops the theory  of  mix marketing by using multichannel  as one of the elements that can increase customer retention   using satisfaction mediation and customer loyalty. Mechanical determination of sample units in this study is a  purposive sampling, of 89 respondents. Generalized Structured Component Analysis (GSCA was applied to test the hypotheses. The results of this study indicate that direct multichannel not  significantly effect the customer retention. Customer satisfaction can not be a perfect mediation  and the customer loyalty can be a perfect mediation in the relationship between multichannel and customer retention. This study contributes to the banking industry in applying the concept of the mix marketing.

  6. Comparison of planform multi-channel network characteristics of alluvial and bedrock constrained large rivers

    Science.gov (United States)

    Carling, P. A.; Meshkova, L.; Robinson, R. A.

    2011-12-01

    The Mekong River in northern Cambodia is an multi-channel mixed bedrock-alluvial river but it was poorly researched until present. Preliminary study of the Mekong geomorphology was conducted by gathering existing knowledge of its geological and tectonic settings, specific riparian vegetation and ancient alluvial terraces in which the river has incised since the Holocene. Altogether this process has allowed a geomorphological portrait of the river to be composed within the Quaternary context. Following this outline, the planform characteristics of the Mekong River network are compared, using analysis of channel network and islands configurations, with the fluvial patterns of the Orange River (South Africa), Upper Columbia River (Canada) and the Ganga River (India, Bangladesh). These rivers are selected as examples of multi-channel mixed bedrock alluvial, anastomosed alluvial and braided alluvial rivers respectively. Network parameters such as channel bifurcation angles asymmetry, sinuosity, braid intensity and island morphometric shape metrics are compared and contrasted between bedrock and alluvial systems. In addition, regional and local topographic trend surfaces produced for each river planform help explain the local changes in river direction and the degree of anastomosis, and distinguish the bedrock-alluvial rivers from the alluvial rivers. Variations between planform characteristics are to be explained by channel forming processes and in the case of mixed bedrock-alluvial rivers mediated by structural control. Channel metrics (derived at the reach-scale) provide some discrimination between different multi-channel patterns but are not always robust when considered singly. In contrast, island shape metrics (obtained at subreach-scale) allow robust discrimination between alluvial and bedrock systems.

  7. Multichannel feedforward control schemes with coupling compensation for active sound profiling

    Science.gov (United States)

    Mosquera-Sánchez, Jaime A.; Desmet, Wim; de Oliveira, Leopoldo P. R.

    2017-05-01

    Active sound profiling includes a number of control techniques that enables the equalization, rather than the mere reduction, of acoustic noise. Challenges may rise when trying to achieve distinct targeted sound profiles simultaneously at multiple locations, e.g., within a vehicle cabin. This paper introduces distributed multichannel control schemes for independently tailoring structural borne sound reaching a number of locations within a cavity. The proposed techniques address the cross interactions amongst feedforward active sound profiling units, which compensate for interferences of the primary sound at each location of interest by exchanging run-time data amongst the control units, while attaining the desired control targets. Computational complexity, convergence, and stability of the proposed multichannel schemes are examined in light of the physical system at which they are implemented. The tuning performance of the proposed algorithms is benchmarked with the centralized and pure-decentralized control schemes through computer simulations on a simplified numerical model, which has also been subjected to plant magnitude variations. Provided that the representation of the plant is accurate enough, the proposed multichannel control schemes have been shown as the only ones that properly deliver targeted active sound profiling tasks at each error sensor location. Experimental results in a 1:3-scaled vehicle mock-up further demonstrate that the proposed schemes are able to attain reductions of more than 60 dB upon periodic disturbances at a number of positions, while resolving cross-channel interferences. Moreover, when the sensor/actuator placement is found as defective at a given frequency, the inclusion of a regularization parameter in the cost function is seen to not hinder the proper operation of the proposed compensation schemes, at the time that it assures their stability, at the expense of losing control performance.

  8. Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jun Li

    2012-08-01

    Full Text Available With recent developments in terrestrial wireless networks and advances in acoustic communications, multichannel technologies have been proposed to be used in underwater networks to increase data transmission rate over bandwidth-limited underwater channels. Due to high bit error rates in underwater networks, an efficient error control technique is critical in the logical link control (LLC sublayer to establish reliable data communications over intrinsically unreliable underwater channels. In this paper, we propose a novel protocol stack architecture featuring cross-layer design of LLC sublayer and more efficient packetto- channel scheduling for multichannel underwater sensor networks. In the proposed stack architecture, a selective-repeat automatic repeat request (SR-ARQ based error control protocol is combined with a dynamic channel scheduling policy at the LLC sublayer. The dynamic channel scheduling policy uses the channel state information provided via cross-layer design. It is demonstrated that the proposed protocol stack architecture leads to more efficient transmission of multiple packets over parallel channels. Simulation studies are conducted to evaluate the packet delay performance of the proposed cross-layer protocol stack architecture with two different scheduling policies: the proposed dynamic channel scheduling and a static channel scheduling. Simulation results show that the dynamic channel scheduling used in the cross-layer protocol stack outperforms the static channel scheduling. It is observed that, when the dynamic channel scheduling is used, the number of parallel channels has only an insignificant impact on the average packet delay. This confirms that underwater sensor networks will benefit from the use of multichannel communications.

  9. A high-throughput, multi-channel photon-counting detector with picosecond timing

    Science.gov (United States)

    Lapington, J. S.; Fraser, G. W.; Miller, G. M.; Ashton, T. J. R.; Jarron, P.; Despeisse, M.; Powolny, F.; Howorth, J.; Milnes, J.

    2009-06-01

    High-throughput photon counting with high time resolution is a niche application area where vacuum tubes can still outperform solid-state devices. Applications in the life sciences utilizing time-resolved spectroscopies, particularly in the growing field of proteomics, will benefit greatly from performance enhancements in event timing and detector throughput. The HiContent project is a collaboration between the University of Leicester Space Research Centre, the Microelectronics Group at CERN, Photek Ltd., and end-users at the Gray Cancer Institute and the University of Manchester. The goal is to develop a detector system specifically designed for optical proteomics, capable of high content (multi-parametric) analysis at high throughput. The HiContent detector system is being developed to exploit this niche market. It combines multi-channel, high time resolution photon counting in a single miniaturized detector system with integrated electronics. The combination of enabling technologies; small pore microchannel plate devices with very high time resolution, and high-speed multi-channel ASIC electronics developed for the LHC at CERN, provides the necessary building blocks for a high-throughput detector system with up to 1024 parallel counting channels and 20 ps time resolution. We describe the detector and electronic design, discuss the current status of the HiContent project and present the results from a 64-channel prototype system. In the absence of an operational detector, we present measurements of the electronics performance using a pulse generator to simulate detector events. Event timing results from the NINO high-speed front-end ASIC captured using a fast digital oscilloscope are compared with data taken with the proposed electronic configuration which uses the multi-channel HPTDC timing ASIC.

  10. Multi-channel analysis of passive surface waves based on cross-correlations

    Science.gov (United States)

    Cheng, F.; Xia, J.; Xu, Z.; Hu, Y.

    2015-12-01

    Traditional active seismic survey can no longer be properly applied in highly populated urban areas due to restrictions in modern civilian life styles. Passive seismic methods, however, have gained much more attention from the engineering geophysics community because of their environmental friendly and deeper investigation depth. Due to extracting signal from noise has never been as comfortable as that in active seismic survey, how to make it more efficiently and accurately has been emphasized. We propose a multi-channel analysis of passive surface waves (MAPW) based on long noise sequences cross-correlations to meet the demand for increasing investigation depth by acquiring surface-wave data at a relative low-frequency range (1 Hz ≤ f ≤ 10 Hz) in urban areas. We utilize seismic interferometry to produce common virtual source gathers from one-hour-long noise records and do dispersion measurements by using the classic passive multi-channel analysis of surface waves (PMASW). We used synthetic tests to demonstrate the advantages of MAPW for various noise distributions. Results show that our method has the superiority of maximizing the analysis accuracy. Finally, we used two field data applications to demonstrate the advantages of our MAPW over the classic PMASW on isolating azimuth of the predominant noise sources and the effectivity of combined survey of active multi-channel analysis of surface waves (MASW) and MAPW. We suggest, for the field operation using MAPW, that a parallel receiver line which is close to a main road or river, if any, with one or two hours noise observation will be an effective means for an unbiased dispersion image. Keywords: passive seismic method, MAPW, MASW, cross-correlation, directional noise source, spatial-aliasing effects, inversion

  11. High-pressure duo-multichannel soft x-ray spectrometer for tokamak plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Schwob, J.L.; Wouters, A.W.; Suckewer, S.

    1987-03-01

    A high-resolution, time-resolving soft X-ray multichannel spectrometer (SOXMOS) that permits the simultaneous measurement of emission in two different spectral ranges has been developed and tested extensively for tokamak plasma diagnostics. The basic instrument is a high-resolution, interferometrically adjusted, extreme grazing incidence Schwob-Fraenkel duochromator. The instrument is equipped with two multichannel detectors that are adjusted interferometrically and scan along the Rowland circle. Each consists of an MgF/sub 2/ coated, funneled microchannel plate, associated with a phosphor screen image intensifier that is coupled to a 1024-element photodiode array by a flexible fibrer optic conduit. The total wavelength coverage of the instrument is 5 to 340/sup 0/ A with a measured resolution (FWHM) of about 0.2 A when equipped with a 600 g/mm grating, and 5 to 85 A with a resolution of about 0.06 A using a 2400 g/mm grating. The simultaneous spectral coverage of each detector varies from 15 A at the short wavelength limit to 70 A at the long wavelength limit with the lower dispersion grating. The minimum read-out time for a full spectral portion is 17 ms, but several individual lines can be measured with 1 ms time resolution by selected pixel readout. Higher time resolution can be achieved by replacing one multichannel detector with a single channel electron multiplier detector. Examples of data from the PLT and TFTR tokamaks are presented to illustrate the instrument's versatility, high spectral resolution, and high signal-to-noise ratio even in the 10 A region. 44 refs., 20 figs.

  12. Spherical Deconvolution of Multichannel Diffusion MRI Data with Non-Gaussian Noise Models and Spatial Regularization.

    Directory of Open Access Journals (Sweden)

    Erick J Canales-Rodríguez

    Full Text Available Spherical deconvolution (SD methods are widely used to estimate the intra-voxel white-matter fiber orientations from diffusion MRI data. However, while some of these methods assume a zero-mean Gaussian distribution for the underlying noise, its real distribution is known to be non-Gaussian and to depend on many factors such as the number of coils and the methodology used to combine multichannel MRI signals. Indeed, the two prevailing methods for multichannel signal combination lead to noise patterns better described by Rician and noncentral Chi distributions. Here we develop a Robust and Unbiased Model-BAsed Spherical Deconvolution (RUMBA-SD technique, intended to deal with realistic MRI noise, based on a Richardson-Lucy (RL algorithm adapted to Rician and noncentral Chi likelihood models. To quantify the benefits of using proper noise models, RUMBA-SD was compared with dRL-SD, a well-established method based on the RL algorithm for Gaussian noise. Another aim of the study was to quantify the impact of including a total variation (TV spatial regularization term in the estimation framework. To do this, we developed TV spatially-regularized versions of both RUMBA-SD and dRL-SD algorithms. The evaluation was performed by comparing various quality metrics on 132 three-dimensional synthetic phantoms involving different inter-fiber angles and volume fractions, which were contaminated with noise mimicking patterns generated by data processing in multichannel scanners. The results demonstrate that the inclusion of proper likelihood models leads to an increased ability to resolve fiber crossings with smaller inter-fiber angles and to better detect non-dominant fibers. The inclusion of TV regularization dramatically improved the resolution power of both techniques. The above findings were also verified in human brain data.

  13. Spherical Deconvolution of Multichannel Diffusion MRI Data with Non-Gaussian Noise Models and Spatial Regularization.

    Science.gov (United States)

    Canales-Rodríguez, Erick J; Daducci, Alessandro; Sotiropoulos, Stamatios N; Caruyer, Emmanuel; Aja-Fernández, Santiago; Radua, Joaquim; Yurramendi Mendizabal, Jesús M; Iturria-Medina, Yasser; Melie-García, Lester; Alemán-Gómez, Yasser; Thiran, Jean-Philippe; Sarró, Salvador; Pomarol-Clotet, Edith; Salvador, Raymond

    2015-01-01

    Spherical deconvolution (SD) methods are widely used to estimate the intra-voxel white-matter fiber orientations from diffusion MRI data. However, while some of these methods assume a zero-mean Gaussian distribution for the underlying noise, its real distribution is known to be non-Gaussian and to depend on many factors such as the number of coils and the methodology used to combine multichannel MRI signals. Indeed, the two prevailing methods for multichannel signal combination lead to noise patterns better described by Rician and noncentral Chi distributions. Here we develop a Robust and Unbiased Model-BAsed Spherical Deconvolution (RUMBA-SD) technique, intended to deal with realistic MRI noise, based on a Richardson-Lucy (RL) algorithm adapted to Rician and noncentral Chi likelihood models. To quantify the benefits of using proper noise models, RUMBA-SD was compared with dRL-SD, a well-established method based on the RL algorithm for Gaussian noise. Another aim of the study was to quantify the impact of including a total variation (TV) spatial regularization term in the estimation framework. To do this, we developed TV spatially-regularized versions of both RUMBA-SD and dRL-SD algorithms. The evaluation was performed by comparing various quality metrics on 132 three-dimensional synthetic phantoms involving different inter-fiber angles and volume fractions, which were contaminated with noise mimicking patterns generated by data processing in multichannel scanners. The results demonstrate that the inclusion of proper likelihood models leads to an increased ability to resolve fiber crossings with smaller inter-fiber angles and to better detect non-dominant fibers. The inclusion of TV regularization dramatically improved the resolution power of both techniques. The above findings were also verified in human brain data.

  14. A 12-bit SAR ADC integrated on a multichannel silicon drift detector readout IC

    Energy Technology Data Exchange (ETDEWEB)

    Schembari, F., E-mail: filippo.schembari@polimi.it [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, via Golgi 40, 20133 Milano (Italy); INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Bellotti, G.; Fiorini, C. [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, via Golgi 40, 20133 Milano (Italy); INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2016-07-11

    A 12-bit analog-to-digital converter (ADC) addressed to Silicon-Drift Detectors (SDDs) multichannel readout ASICs for X- and gamma-ray applications is presented. Aiming at digitizing output multiplexed data from the upstream analog filters banks, the converter must ensure 11-bit accuracy and a sampling frequency of about 5 MS/s. The ADC architecture is the charge-redistribution (CR) successive-approximation register (SAR). A fully differential topology has also been chosen for better rejection of common-mode noise and disturbances. The internal DAC is made of binary-scaled capacitors, whose bottom plates are switched by the SAR logic to perform the binary search of the analog input value by means of the monotonic switching scheme. The A/D converter is integrated on SFERA, a multichannel ASIC fabricated in a standard CMOS 0.35 μm 3.3 V technology and it occupies an area of 0.42 mm{sup 2}. Simulated static performance shows monotonicity over the whole input–output characteristic. The description of the circuit topology and of inner blocks architectures together with the experimental characterization is here presented. - Highlights: • X- and γ-ray spectroscopy front-ends need to readout a high number of detectors. • Design efforts are increasingly oriented to compact and low-power ASICs. • A possible solution is the on-chip integration of the analog-to-digital converter. • A 12-bit CR successive-approximation-register ADC has been developed. • It is a suitable candidate as the digitizer to be integrated in multichannel ASICs.

  15. A low-cost multichannel wireless neural stimulation system for freely roaming animals

    Science.gov (United States)

    Alam, Monzurul; Chen, Xi; Fernandez, Eduardo

    2013-12-01

    Objectives. Electrical stimulation of nerve tissue and recording of neural activity are the basis of many therapies and neural prostheses. Conventional stimulation systems have a number of practical limitations, especially in experiments involving freely roaming subjects. Our main objective was to develop a modular, versatile and inexpensive multichannel wireless system able to overcome some of these constraints. Approach. We have designed and implemented a new multichannel wireless neural stimulator based on commercial components. The system is small (2 cm × 4 cm × 0.5 cm) and light in weight (9 g) which allows it to be easily carried in a small backpack. To test and validate the performance and reliability of the whole system we conducted several bench tests and in vivo experiments. Main results. The performance and accuracy of the stimulator were comparable to commercial threaded systems. Stimulation sequences can be constructed on-the-fly with 251 selectable current levels (from 0 to 250 µA) with 1 µA step resolution. The pulse widths and intervals can be as long as 65 ms in 2 µs time resolution. The system covers approximately 10 m of transmission range in a regular laboratory environment and 100 m in free space (line of sight). Furthermore it provides great flexibility for experiments since it allows full control of the stimulator and the stimulation parameters in real time. When there is no stimulation, the device automatically goes into low-power sleep mode to preserve battery power. Significance. We introduce the design of a powerful multichannel wireless stimulator assembled from commercial components. Key features of the system are their reliability, robustness and small size. The system has a flexible design that can be modified straightforwardly to tailor it to any specific experimental need. Furthermore it can be effortlessly adapted for use with any kind of multielectrode arrays.

  16. Multi-channel electrical impedance tomography for regional tissue hydration monitoring.

    Science.gov (United States)

    Chen, Xiaohui; Kao, Tzu-Jen; Ashe, Jeffrey M; Boverman, Gregory; Sabatini, James E; Davenport, David M

    2014-06-01

    Poor assessment of hydration status during hemodialysis can lead to under- or over-hydration in patients with consequences of increased morbidity and mortality. In current practice, fluid management is largely based on clinical assessments to estimate dry weight (normal hydration body weight). However, hemodialysis patients usually have co-morbidities that can make the signs of fluid status ambiguous. Therefore, achieving normal hydration status remains a major challenge for hemodialysis therapy. Electrical impedance technology has emerged as a promising method for hydration monitoring due to its non-invasive nature, low cost and ease-of-use. Conventional electrical impedance-based hydration monitoring systems employ single-channel current excitation (either 2-electrode or 4-electrode methods) to perturb and extract averaged impedance from bulk tissue and use generalized models from large populations to derive hydration estimates. In the present study, a prototype, single-frequency electrical impedance tomography (EIT) system with simultaneous multi-channel current excitation was used to enable regional hydration change detection. We demonstrated the capability to detect a difference in daily impedance change between left leg and right leg in healthy human subjects, who wore a compression sock only on one leg to reduce daily gravitational fluid accumulation. The impedance difference corresponded well with the difference of lower leg volume change between left leg and right leg measured by volumetry, which on average is ~35 ml, accounting for 0.7% of the lower leg volume. We have demonstrated the feasibility of using multi-channel EIT to extract hydration information in different tissue layers with minimal skin interference. Our simultaneous, multi-channel current excitation approach provides an effective method to separate electrode contact impedance and skin condition artifacts from hydration signals. The prototype system has the potential to be used in clinical

  17. 3D multi-channel bi-functionalized silk electrospun conduits for peripheral nerve regeneration.

    Science.gov (United States)

    Dinis, T M; Elia, R; Vidal, G; Dermigny, Q; Denoeud, C; Kaplan, D L; Egles, C; Marin, F

    2015-01-01

    Despite technological advances over the past 25 years, a complete recovery from peripheral nerve injuries remains unsatisfactory today. The autograft is still considered the "gold standard" in clinical practice; however, postoperative complications and limited availability of nerve tissue have motivated the development of alternative approaches. Among them, the development of biomimetic nerve graft substitutes is one of the most promising strategies. In this study, multichanneled silk electrospun conduits bi-functionalized with Nerve Growth Factor (NGF) and Ciliary Neurotropic Factor (CNTF) were fabricated to enhance peripheral nerve regeneration. These bioactive guides consisting of longitudinally oriented channels and aligned nanofibers were designed in order to mimic the fascicular architecture and fibrous extracellular matrix found in native nerve. The simple use of the electrospinning technique followed by a manual manipulation to manufacture these conduits provides tailoring of channel number and diameter size to create perineurium-like structures. Functionalization of the silk fibroin nanofiber did not affect its secondary structure and chemical property. ELISA assays showed the absence of growth factors passive release from the functionalized fibers avoiding the topical accumulation of proteins. In addition, our biomimetic multichanneled functionalized nerve guides displayed a mechanical behavior comparable to that of rat sciatic nerve with an ultimate peak stress of 4.0 ± 0.6 MPa and a corresponding elongation at failure of 156.8 ± 46.7%. Taken together, our results demonstrate for the first time our ability to design and characterize a bi-functionalized nerve conduit consisting of electrospun nanofibers with multichannel oriented and nanofibers aligned for peripheral regeneration. Our bioactive silk tubes thus represent a new and promising technique towards the creation of a biocompatible nerve guidance conduit. Copyright © 2014 Elsevier Ltd. All

  18. An oject oriented environment for multi-channel signal analysis and understanding

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, W.J.; Dowla, F.U. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    We describe an interactive signal analysis an understanding tool for multichannel signals. The system, written entirely in the C++ language, takes full advantage of the modern workstation GUI tools and integrates traditional signal-processing methods with intelligent domain-specific tools for the exploration and analysis of semistructured problems. By semistructured problems, we mean problems that require a high degree of interactive analysis, and further, the analysis steps are highly adaptive. In other words, a finite number of rules cannot be used to obtain a good solution to the problem.

  19. Assessment of an ICA-based noise reduction method for multi-channel auditory evoked potentials

    Science.gov (United States)

    Mirahmadizoghi, Siavash; Bell, Steven; Simpson, David

    2015-03-01

    In this work a new independent component analysis (ICA) based method for noise reduction in evoked potentials is evaluated on for auditory late responses (ALR) captured with a 63-channel electroencephalogram (EEG) from 10 normal-hearing subjects. The performance of the new method is compared with a single channel alternative in terms of signal to noise ratio (SNR), the number of channels with an SNR above an empirically derived statistical critical value and an estimate of hearing threshold. The results show that the multichannel signal processing method can significantly enhance the quality of the signal and also detected hearing thresholds significantly lower than with the single channel alternative.

  20. A Multi-channel Pre-processing Circuit for Signals from Thermocouple/Thermister

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper,a new developed multi-channel pre-processing circuit for signals from temperature sensor was introduced in brief.This circuit was developed to collect and amplify the signals from temperature sensor.This is a universal circuit.It can be used to process the signals from thermocouples and also used to process signals from thermistors.This circuit was mounted in a standard box(440W×405D×125H mm)as an instrument.The

  1. Maximum likelihood based multi-channel isotropic reverberation reduction for hearing aids

    DEFF Research Database (Denmark)

    Kuklasiński, Adam; Doclo, Simon; Jensen, Søren Holdt;

    2014-01-01

    We propose a multi-channel Wiener filter for speech dereverberation in hearing aids. The proposed algorithm uses joint maximum likelihood estimation of the speech and late reverberation spectral variances, under the assumption that the late reverberant sound field is cylindrically isotropic....... The dereverberation performance of the algorithm is evaluated using computer simulations with realistic hearing aid microphone signals including head-related effects. The algorithm is shown to work well with signals reverberated both by synthetic and by measured room impulse responses, achieving improvements...

  2. Wide-range, picoampere-sensitivity multichannel VLSI potentiostat for neurotransmitter sensing.

    Science.gov (United States)

    Murari, Kartikeya; Thakor, Nitish; Stanacevic, Milutin; Cauwenberghs, Gert

    2004-01-01

    Neurotransmitter sensing is critical in studying nervous pathways and neurological disorders. A 16-channel current-measuring VLSI potentiostat with multiple ranges from picoamperes to microamperes is presented for electrochemical detection of electroactive neurotransmitters like dopamine, nitric oxide etc. The analog-to-digital converter design employs a current-mode, first-order single-bit delta-sigma modulator architecture with a two-stage, digitally reconfigurable oversampling ratio for ranging the conversion scale. An integrated prototype is fabricated in CMOS technology, and experimentally characterized. Real-time multi-channel acquisition of dopamine concentration in vitro is performed with a microfabricated sensor array.

  3. 4 × 160-Gbit/s multi-channel regeneration in a single fiber

    DEFF Research Database (Denmark)

    Wang, Ju; Ji, Hua; Hu, Hao;

    2014-01-01

    Simultaneous regeneration of four high-speed (160 Gbit/s) wavelength-division multiplexed (WDM) and polarization-division multiplexed (PDM) signals in a single highly nonlinear fiber (HNLF) is demonstrated. The regeneration operation is based on four-wave mixing in HNLF, where the degraded data...... phase modulation of the CW light. Mitigation of the inter-channel nonlinearities is achieved mainly through an inter-channel 0.5 bit slot time delay. Bidirectional propagation is also applied to relieve the inter-channel four-wave mixing. The multi-channel regeneration performance is validated by bit...

  4. A Conflict Avoidance Data Allocation Algorithm in a Multi-channel Broadcast Environment

    Directory of Open Access Journals (Sweden)

    Kai Liu

    2010-03-01

    Full Text Available On-demand broadcast is an effective data dissemination approach in mobile computing. Recently, a large number of applications have been developed in broadcast systems equipped with multiple channels. In this study, we investigate the data scheduling issues arising in multi-channel on-demand broadcast. The bandwidth utilization problem, which renders a poor performance of existing algorithms, is explored and examined. To tackle the observed problem, a novel scheduling algorithm is proposed, which aims at avoiding the conflict in data allocation and therewith, improving the bandwidth utilization. Results from our simulation study demonstrate the superiority of the proposed algorithm.

  5. A new approach of watermarking technique by means multichannel wavelet functions

    Science.gov (United States)

    Agreste, Santa; Puccio, Luigia

    2012-12-01

    The digital piracy involving images, music, movies, books, and so on, is a legal problem that has not found a solution. Therefore it becomes crucial to create and to develop methods and numerical algorithms in order to solve the copyright problems. In this paper we focus the attention on a new approach of watermarking technique applied to digital color images. Our aim is to describe the realized watermarking algorithm based on multichannel wavelet functions with multiplicity r = 3, called MCWM 1.0. We report a large experimentation and some important numerical results in order to show the robustness of the proposed algorithm to geometrical attacks.

  6. A multichannel bioimpedance monitor for full-body blood flow monitoring.

    Science.gov (United States)

    Vondra, Vlastimil; Jurak, Pavel; Viscor, Ivo; Halamek, Josef; Leinveber, Pavel; Matejkova, Magdalena; Soukup, Ladislav

    2016-02-01

    The design, properties, and possible diagnostic contribution of a multichannel bioimpedance monitor (MBM) with three independent current sources are presented in this paper. The simultaneous measurement of bioimpedance at 18 locations (the main part of the body, legs, arms, and neck) provides completely new information, on the basis of which more precise haemodynamic parameters can be obtained. The application of the MBM during various haemodynamic stages, such as resting in a supine position, tilting, exercise stress, and various respiration manoeuvres, is demonstrated. Statistical analysis on a group of 34 healthy volunteers is presented for demonstration of blood flow monitoring by using the proposed method.

  7. A Multi-Channel MAC Protocol For Wireless Hospital Sensor Networks

    CERN Document Server

    Slimane, Jamila Ben; Frikha, Mounir; Koubâa, Anis

    2008-01-01

    Both IEEE 802.15.4 and 802.15.4a standards allow for dynamic channel allocation and use of multiple channels available at their physical layers but its MAC protocols are designed only for single channel. Also, sensor's transceivers such as CC2420 provide multiple channels and channel switch latency of CC2420 transceiver is very short just about 200 micro seconds. In order to enhance both energy efficiency and to shorten end to end delay, we propose, in this report, a new MAC protocol allowing multi-channel allocation for 802.15.4a compliant devices.

  8. Tunable omnidirectional multichannel filters based on dual-defective photonic crystals containing negative-index materials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yihang, E-mail: kallenmail@sina.co [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)

    2009-04-07

    Multiple defect modes may generate in one-dimensional dual-defective photonic crystals containing negative-index materials. The interference between the two kinds of defect states of the proposed structure is avoided. Therefore, the frequency, frequency interval and number of the defect modes corresponding to different kinds of defects can be tuned independently as desired. These defect modes inside the zero n-bar gap are insensitive to the incident angle. It thus opens a promising way to fabricate omnidirectional multichannel filters with specific channels.

  9. Spatial Decision Forests for Glioma Segmentation in Multi-Channel MR Images

    OpenAIRE

    Geremia, Ezequiel; Menze, Bjoern H.; Ayache, Nicholas

    2012-01-01

    International audience; A fully automatic algorithm is presented for the automatic segmentation of gliomas in 3D MR images. It builds on the discriminative random decision forest framework to provide a voxel-wise probabilistic classi cation of the volume. Our method uses multi-channel MR intensi- ties (T1, T1C, T2, Flair), spatial prior and long-range comparisons with 3D regions to discriminate lesions. A symmetry feature is introduced ac- counting for the fact that gliomas tend to develop in...

  10. On a multi-channel transportation loss system with controlled input and controlled service

    Directory of Open Access Journals (Sweden)

    Jewgeni Dshalalow

    1987-01-01

    Full Text Available A multi-channel loss queueing system is investigated. The input stream is a controlled point process. The service in each of m parallel channels depends on the state of the system at certain moments of time when input and service may be controlled. To obtain explicitly the limiting distribution of the main process (Zt (the number of busy channels in equilibrium, an auxiliary three dimensional process with two additional components (one of them is a semi-Markov process is treated as semi-regenerative process. An optimization problem is discussed. Simple expressions for an objective function are derived.

  11. Effects, determination, and correction of count rate nonlinearity in multi-channel analog electron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Reber, T. J.; Plumb, N. C.; Waugh, J. A.; Dessau, D. S. [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)

    2014-04-15

    Detector counting rate nonlinearity, though a known problem, is commonly ignored in the analysis of angle resolved photoemission spectroscopy where modern multichannel electron detection schemes using analog intensity scales are used. We focus on a nearly ubiquitous “inverse saturation” nonlinearity that makes the spectra falsely sharp and beautiful. These artificially enhanced spectra limit accurate quantitative analysis of the data, leading to mistaken spectral weights, Fermi energies, and peak widths. We present a method to rapidly detect and correct for this nonlinearity. This algorithm could be applicable for a wide range of nonlinear systems, beyond photoemission spectroscopy.

  12. Multichannel microfluidic chip for rapid and reliable trapping and imaging plant-parasitic nematodes

    Science.gov (United States)

    Amrit, Ratthasart; Sripumkhai, Witsaroot; Porntheeraphat, Supanit; Jeamsaksiri, Wutthinan; Tangchitsomkid, Nuchanart; Sutapun, Boonsong

    2013-05-01

    Faster and reliable testing technique to count and identify nematode species resided in plant roots is therefore essential for export control and certification. This work proposes utilizing a multichannel microfluidic chip with an integrated flow-through microfilter to retain the nematodes in a trapping chamber. When trapped, it is rather simple and convenient to capture images of the nematodes and later identify their species by a trained technician. Multiple samples can be tested in parallel using the proposed microfluidic chip therefore increasing number of samples tested per day.

  13. Optical-network-connected multi-channel 96-GHz-band distributed radar system

    Science.gov (United States)

    Kanno, Atsushi; Kuri, Toshiaki; Kawanishi, Tetsuya

    2015-05-01

    The millimeter-wave (MMW) radar is a promising candidate for high-precision imaging because of its short wavelength and broad range of available bandwidths. In particular in the frequency range of 92-100 GHz, which is regulated for radiolocation, an atmospheric attenuation coefficient less than 1 dB/km limits the imaging range. Therefore, a combination of MMW radar and distributed antenna system directly connected to optical fiber networks can realize both high-precision imaging and large-area surveillance. In this paper, we demonstrate a multi-channel MMW frequency-modulated continuous-wave distributed radar system connected to an analog radio-over-fiber network.

  14. Rapid identification of bacterial biofilms and biofilm wound models using a multichannel nanosensor.

    Science.gov (United States)

    Li, Xiaoning; Kong, Hao; Mout, Rubul; Saha, Krishnendu; Moyano, Daniel F; Robinson, Sandra M; Rana, Subinoy; Zhang, Xinrong; Riley, Margaret A; Rotello, Vincent M

    2014-12-23

    Identification of infectious bacteria responsible for biofilm-associated infections is challenging due to the complex and heterogeneous biofilm matrix. To address this issue and minimize the impact of heterogeneity on biofilm identification, we developed a gold nanoparticle (AuNP)-based multichannel sensor to detect and identify biofilms based on their physicochemical properties. Our results showed that the sensor can discriminate six bacterial biofilms including two composed of uropathogenic bacteria. The capability of the sensor was further demonstrated through discrimination of biofilms in a mixed bacteria/mammalian cell in vitro wound model.

  15. Maximum likelihood based multi-channel isotropic reverberation reduction for hearing aids

    DEFF Research Database (Denmark)

    Kuklasiński, Adam; Doclo, Simon; Jensen, Søren Holdt

    2014-01-01

    We propose a multi-channel Wiener filter for speech dereverberation in hearing aids. The proposed algorithm uses joint maximum likelihood estimation of the speech and late reverberation spectral variances, under the assumption that the late reverberant sound field is cylindrically isotropic....... The dereverberation performance of the algorithm is evaluated using computer simulations with realistic hearing aid microphone signals including head-related effects. The algorithm is shown to work well with signals reverberated both by synthetic and by measured room impulse responses, achieving improvements...

  16. [Study of cortico-cortical functional connectivity with vector autoregressive model of multichannel EEG].

    Science.gov (United States)

    Kurganskiĭ, A V

    2010-01-01

    This review focuses on some practical issues of using vector autoregressive model (VAR) for multichannel EEG analysis. Those issues include: EEG preprocessing, checking if the necessary conditions of VAR model applicability are met, optimal order selection, and assessment of the validity of fitted VAR model. Both non-directed (ordinary coherence and imaginary part of the complex-valued coherency) and directed (directed coherence, directed transfer function and partial directed coherence) measures of the strength of inter-channel coupling are discussed. These measures are analyzed with respect to their properties (scale invariance) and known problems in using them (spurious interactions, volume conduction).

  17. Multi-Channel Autonomous Information System Performance with Positional Signal State Analyzers at the Channel Outputs

    Directory of Open Access Journals (Sweden)

    V. K. Hohlov

    2016-01-01

    Full Text Available The article presents a statement of technique to research performances of multi-channel combo standalone information systems with positional analyzers of the signal states at the channel outputs. In most cases, in considered multi-channel systems there has been impossible to coincide in time the random moments of signals coming from the objects through various channels in all ways of encounter environment and conditions of practical application. The analyzer makes decision on the signal using the discrete operations on the quantized signals of the certain duration from the channel outputs. The analyzer performance is described by a set of Boolean algebra functions defined for all possible states of the signals at the outputs of the channels, and in the general case is specified in a perfect disjunctive normal form. To determine the validity or falsity of functions of the algebra of logics, which are calculated statements concerning the available or unavailable useful signal at the system input, on the authority of the Poretsky’s theorem and the theory of coincidence in time of the random pulse flow of the channels response because of uncorrelated and correlated noise, are obtained dependences to calculate the probabilities of false alarms and omissions of the signals in discrete combined systems. It is shown that the flows of false alarms because of noise at the channel outputs in the system are Poisson streams. On the basis of the ordinary Poisson flows the paper justifies the relationships for calculating the false alarms of the system with uncorrelated and correlated noise in the channels. The paper also justifies the relationships for performance of multichannel combined systems with positional analyzers of the channels states. Based on the obtained relationships was calculated the average coincidence frequency of the extended pulses of the channel response in a dualchannel system, depending on the noise cross-correlation coefficient with

  18. Multichannel Signal Enhancement using Non-Causal, Time-Domain Filters

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Christensen, Mads Græsbøll; Benesty, Jacob

    2013-01-01

    In the vast amount of time-domain filtering methods for speech enhancement, the filters are designed to be causal. Recently, however, it was shown that the noise reduction and signal distortion capabilities of such single-channel filters can be improved by allowing the filters to be non......-causal, multichannel filters for enhancement based on an orthogonal decomposition is proposed. The evaluation shows that there is a potential gain in noise reduction and signal distortion by introducing non-causality. Moreover, experiments on real-life speech show that we can improve the perceptual quality....

  19. A New Dual-electrode and Multi-channel Electrochemical DetectionSystem for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Bing Yi YANG; Jin Yuan MO; Rong LAI

    2004-01-01

    A new type of dual-electrode and multi-channel electrochemical detection technology for capillary electrophoresis is described in this paper. Two detectors(the amperometric detector and the conductometric detector)or two conductometric detectors are connected to the same capillary electrophoresis system. The whole system possesses the advantages of the two electrochemical detectors including sparing time,improving the analytical speed and expanding the sample range.The working electrode and detector cell are handled easily.The system was applied to sample detection with satisfactory results.

  20. Multichannel mode conversion and multiplexing based on a single spatial light modulator for optical communication

    Science.gov (United States)

    Nie, Song; Yu, Song; Cai, Shanyong; Lan, Mingying; Gu, Wanyi

    2016-07-01

    A method is proposed to achieve multichannel mode conversion and multiplexing by dividing a single spatial light modulator into several blocks with the mode conversion pattern and blazed grating loaded on each block. The conversion patterns realize the precise excitation of higher order modes using combined amplitude and phase modulation. The blazed gratings bring together incident beams, so these beams can be coupled into few-mode fiber (FMF). In the experiment, four higher order modes are precisely excited and converge with a tilt angle. Through the simulation method, these beams can be coupled into FMF with small tilt angles (0.0344 deg for LP11 mode).

  1. Single electrode electrochemical detection in hybrid poly(dimethylsiloxane)/glass multichannel micro devices

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Ney Henrique; Almeida, Andre Luis de Jesus de; Piazzeta, Maria Helena de Oliveira; Gobbia, Angelo Luiz [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil). Lab. de Microfabricacao; Jesus, Dosil Pereira de [Instituto Nacional de Ciencia e Tecnologia em Bioanalitica (INCTBio), Campinas, SP (Brazil); Deblire, Ariane; Silva, Jose Alberto Fracassi da [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2009-07-01

    The fabrication process of a novel multichannel {mu}TAS based on PDMS and glass materials and with fully-integrated electrodes for amperometric detection has been described. Using the facilities of the Microfabrication Lab. (LMF) at Brazilian Synchrotron Light Laboratory (LNLS), soft-lithography, lift-off and O{sub 2} plasma surface activation sealing techniques were employed for rapid proto typing of cost effective PDMS/glass microchips. Fast calibration procedures were possible for the electro oxidation of hydroquinone, thiocyanate, and acetaminophen using Au and Cu electrodes. (author)

  2. Multichannel broadcast based on home channel for cognitive radio sensor networks.

    Science.gov (United States)

    Zeng, Fanzi; Tang, Yuting; Pu, Jianjie

    2014-01-01

    Considering the limited resources and the dynamic spectrum distribution in the cognitive radio sensor networks (CRSN), a half-duplex Multichannel broadcast protocol for CRSN is presented based on the home channel. This protocol maintains the networks topology only through the home channel, so there is no need for the public channel to transmit the control information and no need for the synchronization. After network initialization, node broadcasts data via home channel in half-duplex transmission way. The simulation results show that, compared with complete broadcast, the proposed protocol effectively reduces broadcast delay and overhead.

  3. Channel selection based on trust and multiarmed bandit in multiuser, multichannel cognitive radio networks.

    Science.gov (United States)

    Zeng, Fanzi; Shen, Xinwang

    2014-01-01

    This paper proposes a channel selection scheme for the multiuser, multichannel cognitive radio networks. This scheme formulates the channel selection as the multiarmed bandit problem, where cognitive radio users are compared to the players and channels to the arms. By simulation negotiation we can achieve the potential reward on each channel after it is selected for transmission; then the channel with the maximum accumulated rewards is formally chosen. To further improve the performance, the trust model is proposed and combined with multi-armed bandit to address the channel selection problem. Simulation results validate the proposed scheme.

  4. Channel Selection Based on Trust and Multiarmed Bandit in Multiuser, Multichannel Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Fanzi Zeng

    2014-01-01

    Full Text Available This paper proposes a channel selection scheme for the multiuser, multichannel cognitive radio networks. This scheme formulates the channel selection as the multiarmed bandit problem, where cognitive radio users are compared to the players and channels to the arms. By simulation negotiation we can achieve the potential reward on each channel after it is selected for transmission; then the channel with the maximum accumulated rewards is formally chosen. To further improve the performance, the trust model is proposed and combined with multi-armed bandit to address the channel selection problem. Simulation results validate the proposed scheme.

  5. Multichannel Scattering Problem with Non-trivial Asymptotic Non-adiabatic Coupling

    CERN Document Server

    Yakovlev, S L; Elander, N; Belyaev, A K

    2016-01-01

    The multichannel scattering problem in an adiabatic representation is considered. The non-adiabatic coupling matrix is assumed to have a non-trivial constant asymptotic behavior at large internuclear separations. The asymptotic solutions at large internuclear distances are constructed. It is shown that these solutions up to the first order of perturbation theory are identical to the asymptotic solutions of the re-projection approach, which was proposed earlier as a remedy for the electron translation problem in the context of the Born-Oppenheimer treatment.

  6. FPGA-based multi-channel fluorescence lifetime analysis of Fourier multiplexed frequency-sweeping lifetime imaging.

    Science.gov (United States)

    Zhao, Ming; Li, Yu; Peng, Leilei

    2014-09-22

    We report a fast non-iterative lifetime data analysis method for the Fourier multiplexed frequency-sweeping confocal FLIM (Fm-FLIM) system [Opt. Express 22, 10221 (2014)]. The new method, named R-method, allows fast multi-channel lifetime image analysis in the system's FPGA data processing board. Experimental tests proved that the performance of the R-method is equivalent to that of single-exponential iterative fitting, and its sensitivity is well suited for time-lapse FLIM-FRET imaging of live cells, for example cyclic adenosine monophosphate (cAMP) level imaging with GFP-Epac-mCherry sensors. With the R-method and its FPGA implementation, multi-channel lifetime images can now be generated in real time on the multi-channel frequency-sweeping FLIM system, and live readout of FRET sensors can be performed during time-lapse imaging.

  7. Isotopic shift of atom-dimer Efimov resonances in K-Rb mixtures: Critical effect of multichannel Feshbach physics

    CERN Document Server

    Kato, K; Kobayashi, J; Julienne, P S; Inouye, S

    2016-01-01

    The multichannel Efimov physics is investigated in ultracold heteronuclear admixtures of K and Rb atoms. We observe a shift in the scattering length where the first atom-dimer resonance appears in the $^{41}$K-$^{87}$Rb system relative to the position of the previously observed atom-dimer resonance in the $^{40}$K-$^{87}$Rb system. This shift is well explained by our calculations with a three-body model including the van der Waals interactions, and, more importantly, the multichannel spinor physics. With only minor difference in the atomic masses of the admixtures, the shift in the atom-dimer resonance positions can be cleanly ascribed to the isolated and overlapping Feshbach resonances in the $^{40}$K-$^{87}$Rb and $^{41}$K-$^{87}$Rb systems, respectively. Our study demonstrates the role of the multichannel Feshbach physics in determining Efimov resonances in heteronuclear three-body systems.

  8. Preliminary Interpretations of Multi-Channel Seismic Reflection and Magnetic Data on North Anatolian Fault (NAF) in the Eastern Marmara Region, Turkey

    Science.gov (United States)

    Gözde Okut Toksoy, Nigar; Kurt, Hülya; İşseven, Turgay

    2017-04-01

    The North Anatolian Fault (NAF) is 1600 km long, right lateral strike-slip fault nearly E-W elongated between Karlıova in the east and Saros Gulf in the west. NAF splays into two major strands near the west of Bolu city as Northern and Southern strands. Northern strand passes Sapanca Lake and extends towards west and reaches Marmara Sea through the Gulf of Izmit. The area has high seismicity; 1999 Kocaeli (Mw=7.4) and 1999 Düzce (Mw=7.2) earthquakes caused approximately 150 km long surface rupture between the Gulf of Izmit and Bolu. The rupture has four distinct fault segments as Gölcük, Sapanca, Sakarya, and Karadere from west to east. In this study multi-channel seismic and magnetic data are collected for the first time on the Sapanca Segment to investigate the surficial and deeper geometry of the NAF. Previously, the NAF in the eastern Marmara region is investigated using by paleo-seismological data from trenches on the surface rupture of fault or the geomorphological data (Lettis et al., 2000; Dikbaş and Akyüz, 2010) which have shallower depth targets. Crustal structure and seismic velocities for Central Anatolia and eastern Marmara regions are obtained from deeper targeted refraction data (Gürbüz et al., 1992). However, their velocity models do not have the spatial resolution to determine details of the fault zone structure. Multi-channel seismic and magnetic data in this study were acquired on two N-S directed profiles crossing NAF perpendicularly near Kartepe on the western part of the Sapanca Lake in October 2016. The receiver interval is 5 m, shot interval is 5-10 m, and the total length of the profiles are approximately 1400 m. Buffalo Gun is used as a seismic source for deeper penetration. Conventional seismic reflection processing steps are applied to the data. These are geometry definition, editing, filtering, static correction, velocity analysis and deconvolution, stacking and migration. Echos seismic software package in Geophysical Department

  9. 7 CFR 1437.310 - Sea grass and sea oats.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  10. All-optical multi-channel wavelength conversion of Nyquist 16 QAM signal using a silicon waveguide.

    Science.gov (United States)

    Long, Yun; Liu, Jun; Hu, Xiao; Wang, Andong; Zhou, Linjie; Zou, Kaiheng; Zhu, Yixiao; Zhang, Fan; Wang, Jian

    2015-12-01

    We experimentally demonstrate on-chip all-optical multi-channel wavelength conversion of Nyquist 16 ary quadrature amplitude modulation (16 QAM) signal in a silicon waveguide. The measured optical signal-to-noise ratio (OSNR) penalties of wavelength conversion are ∼2  dB. The observed constellations of converted idlers indicate favorable performance of silicon-waveguide-based multi-channel wavelength conversion. We also experimentally study and compare the phase-conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in the silicon waveguide.

  11. Data-Driven Modeling and Prediction of Arctic Sea Ice

    Science.gov (United States)

    Kondrashov, Dmitri; Chekroun, Mickael; Ghil, Michael

    2016-04-01

    We present results of data-driven predictive analyses of sea ice over the main Arctic regions. Our approach relies on the Multilayer Stochastic Modeling (MSM) framework of Kondrashov, Chekroun and Ghil [Physica D, 2015] and it leads to probabilistic prognostic models of sea ice concentration (SIC) anomalies on seasonal time scales. This approach is applied to monthly time series of state-of-the-art data-adaptive decompositions of SIC and selected climate variables over the Arctic. We evaluate the predictive skill of MSM models by performing retrospective forecasts with "no-look ahead" for up to 6-months ahead. It will be shown in particular that the memory effects included intrinsically in the formulation of our non-Markovian MSM models allow for improvements of the prediction skill of large-amplitude SIC anomalies in certain Arctic regions on the one hand, and of September Sea Ice Extent, on the other. Further improvements allowed by the MSM framework will adopt a nonlinear formulation and explore next-generation data-adaptive decompositions, namely modification of Principal Oscillation Patterns (POPs) and rotated Multichannel Singular Spectrum Analysis (M-SSA).

  12. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  13. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  14. Sea Lion Diet Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions pup and breed at four of the nine Channel Islands in southern California. Since 1981, SWFSC MMTD has been conducting a diet study of sea lions...

  15. Light at deep-sea hydrothermal vents

    Science.gov (United States)

    Van Dover, Cindy Lee; Reynolds, George T.; Chave, Alan D.; Tyson, J. Anthony

    Ambient light spectral data were acquired at two deep-sea hydrothermal vents with a temperature of ˜350°C: the Hole-to-Hell site on the East Pacific Rise at 9°N and the Snake-Pit site on the Mid-Atlantic Ridge. Measurements were made with a simple, multi-channel photometer which simultaneously detected light in four 100 nm-wide bands over the wavelength range of 650-1050 nm. Most of the light detected is near-infrared (750-1050 nm), but there is a 19x greater photon flux than expected from thermal radiation alone at shorter wavelengths (650-750 nm) at the Hole-to-Hell vent. At Snake Pit, more light in the 750-850 nm band was observed 10 cm above the orifice where the temperature was 50-100°C than at the 351°C vent opening. These data suggest the presence of non-thermal light sources in the vent environment. Some possible non-thermal mechanisms are identified, but further data will be required to resolve them.

  16. Conrad Deep, Northern Red Sea: Development of an early stage ocean deep within the axial depression

    Science.gov (United States)

    Ehrhardt, A.; Hübscher, C.; Gajewski, D.

    2005-12-01

    The northern Red Sea represents a continental rift in its final stage and close to the following stage of seafloor spreading. Ocean deeps within the evaporites of the northern Red Sea seem to accompany this process and are thought to be surface expressions of first seafloor spreading cells. In 1999 during R/V Meteor cruise M44/3 a dense multichannel seismic and hydroacoustic survey was conducted in order to investigate the initial formation process of the Conrad Deep, a young northern Red Sea deep. Three seismic units were differentiated in the uppermost part of the Miocene evaporites and the Plio-Quaternary sediments. A weakness zone within the evaporites, oblique to the main extension direction of the Red Sea, led to a transtension process within the evaporites that opened the deep. Its formation is directly related to the emplacement of magmatic bodies in its vicinity and the focusing of the Red Sea extension to the axial depression. The Conrad Deep is an intra-evaporite basin that cannot be regarded as surficial expression of a basement structure as the low shear strength of the evaporites decouple the sediments from the basement. However, its position and shape in combination with the accompanying geophysical anomalies point to a strong correlation with the Red Sea rifting process.

  17. Acoustic Investigations of Gas and Gas Hydrate Formations, Offshore Southwestern Black Sea*

    Science.gov (United States)

    Kucuk, H. M.; Dondurur, D.; Ozel, O.; Atgin, O.; Sinayuc, C.; Merey, S.; Parlaktuna, M.; Cifci, G.

    2015-12-01

    The Black Sea is a large intercontinental back-arc basin with relatively high sedimentation rate. The basin was formed as two different sub-basins divided by Mid-Black Sea Ridge. The ridge is completely buried today and the Black Sea became a single basin in the early Miocene that is currently anoxic. Recent acoustic investigations in the Black Sea indicate potential for gas hydrate formation and gas venting. A total of 2500 km multichannel seismic, Chirp sub-bottom profiler and multibeam bathymetry data were collected during three different expeditions in 2010 and 2012 along the southwestern margin of the Black Sea. Box core sediment samples were collected for gas cromatography analysis. Wide spread BSRs and multiple BSRs are observed in the seismic profiles and may be categorized into two different types: cross-cutting BSRs (transecting sedimentary strata) and amplitude BSRs (enhanced reflections). Both types mimic the seabed reflection with polarity reversal. Some undulations of the BSR are observed along seismic profiles probably caused by local pressure and/or temperature changes. Shallow gas sources and chimney vents are clearly indicated by bright reflection anomalies in the seismic data. Gas cromatography results indicate the presence of methane and various components of heavy hydrocarbons, including Hexane. These observations suggest that the gas forming hydrate in the southwestern Black Sea may originate from deeper thermogenic hydrocarbon sources. * This study is supported by 2214-A programme of The Scientific and Technological Research Council of Turkey (TÜBITAK).

  18. Open Ephys: an open-source, plugin-based platform for multichannel electrophysiology

    Science.gov (United States)

    Siegle, Joshua H.; Cuevas López, Aarón; Patel, Yogi A.; Abramov, Kirill; Ohayon, Shay; Voigts, Jakob

    2017-08-01

    Objective. Closed-loop experiments, in which causal interventions are conditioned on the state of the system under investigation, have become increasingly common in neuroscience. Such experiments can have a high degree of explanatory power, but they require a precise implementation that can be difficult to replicate across laboratories. We sought to overcome this limitation by building open-source software that makes it easier to develop and share algorithms for closed-loop control. Approach. We created the Open Ephys GUI, an open-source platform for multichannel electrophysiology experiments. In addition to the standard ‘open-loop’ visualization and recording functionality, the GUI also includes modules for delivering feedback in response to events detected in the incoming data stream. Importantly, these modules can be built and shared as plugins, which makes it possible for users to extend the functionality of the GUI through a simple API, without having to understand the inner workings of the entire application. Main results. In combination with low-cost, open-source hardware for amplifying and digitizing neural signals, the GUI has been used for closed-loop experiments that perturb the hippocampal theta rhythm in a phase-specific manner. Significance. The Open Ephys GUI is the first widely used application for multichannel electrophysiology that leverages a plugin-based workflow. We hope that it will lower the barrier to entry for electrophysiologists who wish to incorporate real-time feedback into their research.

  19. A multi-channel femtoampere-sensitivity conductometric array for biosensing applications.

    Science.gov (United States)

    Gore, Amit; Chakrabartty, Shantanu; Pal, Sudeshna; Alocilja, Evangelyn

    2006-01-01

    Rapid detection of pathogens using field deployable biosensors requires integrated sensing and data processing. Detection of low concentration of biological agents is possible using accurate and real-time signal characterization devices. This paper presents a multi-channel conductometric array that can detect and measure current up to femtoampere range. The architecture uses a novel semi-synchronous SigmaDelta modulation that allows measurement of ultra-small currents by using a hysteretic comparison technique. The architecture achieves higher energy efficiency over a conventional SigmaDelta by reducing the total switching cycles of the comparator. A 3 mm x 3 mm chip implementing a 42 channel potentiostat array has been prototyped in a 0.5 microm CMOS technology. Measured results show 10 bits of resolution, with a sensitivity of upto 50 fA of current. The power consumption of the potentiostat is 11 microW per channel at a sampling rate of 250 kHz. The multi-channel potentiostat has been integrated with a conductometric biosensor for field deployable applications. Results with a Bacillus Cereus based biosensor demonstrate the effectiveness of the potentiostat in characterizing different concentration levels of pathogens in realtime.

  20. Real-time adaptive concepts in acoustics blind signal separation and multichannel echo cancellation

    CERN Document Server

    Schobben, Daniel W E

    2001-01-01

    Blind Signal Separation (BSS) deals with recovering (filtered versions of) source signals from an observed mixture thereof. The term `blind' relates to the fact that there are no reference signals for the source signals and also that the mixing system is unknown. This book presents a new method for blind signal separation, which is developed to work on microphone signals. Acoustic Echo Cancellation (AEC) is a well-known technique to suppress the echo that a microphone picks up from a loudspeaker in the same room. Such acoustic feedback occurs for example in hands-free telephony and can lead to a perceived loud tone. For an application such as a voice-controlled television, a stereo AEC is required to suppress the contribution of the stereo loudspeaker setup. A generalized AEC is presented that is suited for multi-channel operation. New algorithms for Blind Signal Separation and multi-channel Acoustic Echo Cancellation are presented. A background is given in array signal processing methods, adaptive filter the...

  1. An Efficient Method For Multichannel Wireless Mesh Networks With Pulse Coupled Neural Network

    Directory of Open Access Journals (Sweden)

    S.Sobana

    2012-01-01

    Full Text Available Multi cast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes, Generally sensor networks and MANETs uses multicast algorithms which are designed to be energy efficient and to achieve optimal route discovery among mobile nodes whereas wireless mesh networks needs to maximize throughput. Here we propose two multicast algorithms: The Level Channel Assignment (LCA algorithm and the Multi-Channel Multicast (MCM algorithm to improve the throughput for multichannel sand multi interface mesh networks. The algorithm builds efficient multicast trees by minimizing the number of relay nodes and total hop count distance of the trees. Shortest path computation is a classical combinatorial optimization problem. Neural networks have been used for processing path optimization problem. Pulse Coupled Neural Networks (PCNNS suffer from high computational cast for very long paths we propose a new PCNN modal called dual source PCNN (DSPCNN which can improve the computational efficiency two auto waves are produced by DSPCNN one comes from source neuron and other from goal neuron when the auto waves from these two sources meet the DSPCNN stops and then the shortest path is found by backtracking the two auto waves.

  2. Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    A. D. Nguyen

    2006-01-01

    Full Text Available There is a well-tested theory for the computation of salt intrusion in alluvial estuaries that is fully analytical and predictive. The theory uses analytical equations to predict the mixing behaviour of the estuary based on measurable quantities, such as channel topography, river discharge and tidal characteristics. It applies to single-channel topographies and estuaries that demonstrate moderate tidal damping. The Mekong delta is a multi-channel estuary where the tide is damped due to a relatively strong river discharge (in the order of 2000 m3/s, even during the dry season. As a result the Mekong is a strongly riverine estuary. This paper aims to test if the theory can be applied to such a riverine multi-channel estuary, and to see if possible adjustments or generalisations need to be made. The paper presents salt intrusion measurements that were done by moving boat in 2005, to which the salt intrusion model was calibrated. The theory has been expanded to cater for tidal damping. Subsequently the model has been validated with observations made at fixed locations over the years 1998 and 1999. Finally it has been tested whether the Mekong calibration fits the overall predictive equations derived in other estuaries. The test has been successful and led to a slight adjustment of the predictive equation to cater for estuaries that experience a sloping bottom.

  3. A Schedule-based Multi-channel MAC Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ilyoung Chong

    2010-10-01

    Full Text Available Due to the half-duplex property of the sensor radio and the broadcast nature of wireless medium, limited bandwidth remains a pressing issue for wireless sensor networks (WSNs. The design of multi-channel MAC protocols has attracted the interest of many researchers as a cost effective solution to meet the higher bandwidth demand for the limited bandwidth in WSN. In this paper, we present a scheduled-based multi-channel MAC protocol to improve network performance. In our protocol, each receiving node selects (schedules some timeslot(s, in which it may receive data from the intending sender(s. The timeslot selection is done in a conflict free manner, where a node avoids the slots that are already selected by others in its interference range. To minimize the conflicts during timeslot selection, we propose a unique solution by splitting the neighboring nodes into different groups, where nodes of a group may select the slots allocated to that group only. We demonstrate the effectiveness of our approach thorough simulations in terms of performance parameters such as aggregate throughput, packet delivery ratio, end-to-end delay, and energy consumption.

  4. SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals.

    Science.gov (United States)

    Xiong, Jiping; Cai, Lisang; Wang, Fei; He, Xiaowei

    2017-03-03

    Although wrist-type photoplethysmographic (hereafter referred to as WPPG) sensor signals can measure heart rate quite conveniently, the subjects' hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise.

  5. A Non-Invasive Multichannel Hybrid Fiber-Optic Sensor System for Vital Sign Monitoring

    Directory of Open Access Journals (Sweden)

    Marcel Fajkus

    2017-01-01

    Full Text Available In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG. The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS. The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person's chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field.

  6. An Efficient VLSI Architecture for Multi-Channel Spike Sorting Using a Generalized Hebbian Algorithm

    Directory of Open Access Journals (Sweden)

    Ying-Lun Chen

    2015-08-01

    Full Text Available A novel VLSI architecture for multi-channel online spike sorting is presented in this paper. In the architecture, the spike detection is based on nonlinear energy operator (NEO, and the feature extraction is carried out by the generalized Hebbian algorithm (GHA. To lower the power consumption and area costs of the circuits, all of the channels share the same core for spike detection and feature extraction operations. Each channel has dedicated buffers for storing the detected spikes and the principal components of that channel. The proposed circuit also contains a clock gating system supplying the clock to only the buffers of channels currently using the computation core to further reduce the power consumption. The architecture has been implemented by an application-specific integrated circuit (ASIC with 90-nm technology. Comparisons to the existing works show that the proposed architecture has lower power consumption and hardware area costs for real-time multi-channel spike detection and feature extraction.

  7. Maximizing Networking Capacity in Multi-Channel Multi-Radio Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    万鹏俊; 万志国

    2014-01-01

    Providing each node with one or more multi-channel radios offers a promising avenue for enhancing the network capacity by simultaneously exploiting multiple non-overlapping channels through different radio interfaces and mitigating interferences through proper channel assignment. However, it is quite challenging to effectively utilize multiple channels and/or multiple radios to maximize throughput capacity. The National Natural Science Foundation of China (NSFC) Pro ject 61128005 conducted comprehensive algorithmic-theoretic and queuing-theoretic studies of maximizing wireless networking capacity in multi-channel multi-radio (MC-MR) wireless networks under the protocol interference model and fundamentally advanced the state of the art. In addition, under the notoriously hard physical interference model, this project has taken initial algorithmic studies on maximizing the network capacity, with or without power control. We expect the new techniques and tools developed in this project will have wide applications in capacity planning, resource allocation and sharing, and protocol design for wireless networks, and will serve as the basis for future algorithm developments in wireless networks with advanced features, such as multi-input multi-output (MIMO) wireless networks.

  8. Robust detection of multiple sclerosis lesions from intensity-normalized multi-channel MRI

    Science.gov (United States)

    Karpate, Yogesh; Commowick, Olivier; Barillot, Christian

    2015-03-01

    Multiple sclerosis (MS) is a disease with heterogeneous evolution among the patients. Quantitative analysis of longitudinal Magnetic Resonance Images (MRI) provides a spatial analysis of the brain tissues which may lead to the discovery of biomarkers of disease evolution. Better understanding of the disease will lead to a better discovery of pathogenic mechanisms, allowing for patient-adapted therapeutic strategies. To characterize MS lesions, we propose a novel paradigm to detect white matter lesions based on a statistical framework. It aims at studying the benefits of using multi-channel MRI to detect statistically significant differences between each individual MS patient and a database of control subjects. This framework consists in two components. First, intensity standardization is conducted to minimize the inter-subject intensity difference arising from variability of the acquisition process and different scanners. The intensity normalization maps parameters obtained using a robust Gaussian Mixture Model (GMM) estimation not affected by the presence of MS lesions. The second part studies the comparison of multi-channel MRI of MS patients with respect to an atlas built from the control subjects, thereby allowing us to look for differences in normal appearing white matter, in and around the lesions of each patient. Experimental results demonstrate that our technique accurately detects significant differences in lesions consequently improving the results of MS lesion detection.

  9. The Optimized Pseudorandom Digital Modulation Excitation Sequences for Multichannel Ultrasonic Ranging system

    Directory of Open Access Journals (Sweden)

    Zhenjing Yao

    2012-10-01

    Full Text Available The crosstalk in multichannel simultaneously triggered ultrasonic sensors of ultrasonic ranging system may cause false measurement. This paper presents pseudorandom digital modulation excitation sequences for multichannel ultrasonic sensors to avoid crosstalk. To make full use of bandwidth of the ultrasonic sensors, the parameters of the pseudorandom digital modulation methods are configured. A genetic algorithm is applied to optimize the pseudorandom m sequences to obtain the best echo correlation characteristics (i.e., sharpest autocorrelation and flattest cross-correlation. The polarity correlation algorithm in the receiving circuit is implemented by Field Programmable Gate Array. Real experiments have been conducted using ultrasonic ranging system that consists of eight-channel SensComp 600 series instrument-grade electrostatic sensors excited with 2 ms optimized pseudorandom digital modulation sequences. Experimental results shows that the optimized pseudorandom BFSK sequence , which can make the eight-channel ultrasonic ranging system work together without crosstalk and has a maximal 4.1 cm absolute error, has the best performance of all the pseudorandom digital modulation sequences.

  10. A wireless, compact, and scalable bioimpedance measurement system for energy-efficient multichannel body sensor solutions

    Science.gov (United States)

    Ramos, J.; Ausín, J. L.; Lorido, A. M.; Redondo, F.; Duque-Carrillo, J. F.

    2013-04-01

    In this paper, we present the design, realization and evaluation of a multichannel measurement system based on a cost-effective high-performance integrated circuit for electrical bioimpedance (EBI) measurements in the frequency range from 1 kHz to 1 MHz, and a low-cost commercially available radio frequency transceiver device, which provides reliable wireless communication. The resulting on-chip spectrometer provides high measuring EBI capabilities and constitutes the basic node to built EBI wireless sensor networks (EBI-WSNs). The proposed EBI-WSN behaves as a high-performance wireless multichannel EBI spectrometer where the number of nodes, i.e., number of channels, is completely scalable to satisfy specific requirements of body sensor networks. One of its main advantages is its versatility, since each EBI node is independently configurable and capable of working simultaneously. A prototype of the EBI node leads to a very small printed circuit board of approximately 8 cm2 including chip-antenna, which can operate several years on one 3-V coin cell battery. A specifically tailored graphical user interface (GUI) for EBI-WSN has been also designed and implemented in order to configure the operation of EBI nodes and the network topology. EBI analysis parameters, e.g., single-frequency or spectroscopy, time interval, analysis by EBI events, frequency and amplitude ranges of the excitation current, etc., are defined by the GUI.

  11. A wireless multi-channel bioimpedance measurement system for personalized healthcare and lifestyle.

    Science.gov (United States)

    Ramos, Javier; Ausín, José Luis; Lorido, Antonio Manuel; Redondo, Francisco; Duque-Carrillo, Juan Francisco

    2013-01-01

    Miniaturized, noninvasive, wearable sensors constitute a fundamental prerequisite for pervasive, predictive, and preventive healthcare systems. In this sense, this paper presents the design, realization, and evaluation of a wireless multi-channel measurement system based on a cost-effective high-performance integrated circuit for electrical bioimpedance (EBI) measurements in the frequency range from 1 kHz to 1 MHz. The resulting on-chip spectrometer provides high measuring EBI capabilities and together with a low-cost, commercially available radio frequency transceiver device. It provides reliable wireless communication, constitutes the basic node to build EBI wireless sensor networks (EBI-WSNs). The proposed EBI-WSN behaves as a high-performance wireless multi-channel EBI spectrometer, where the number of channels is completely scalable and independently configurable to satisfy specific measurement requirements of each individual. A prototype of the EBI node leads to a very small printed circuit board of approximately 8 cm2 including chip-antenna, which can operate several years on one 3-V coin cell battery and make it suitable for long-term preventive healthcare monitoring.

  12. Development of network-based multichannel neuromuscular electrical stimulation system for stroke rehabilitation.

    Science.gov (United States)

    Qu, Hongen; Xie, Yongji; Liu, Xiaoxuan; He, Xin; Hao, Manzhao; Bao, Yong; Xie, Qing; Lan, Ning

    2016-01-01

    Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and an H-bridge current regulator with a power booster. The structure of the system was a body area network embedded with multiple stimulators and a communication protocol of controlled area network to transmit muscle stimulation parameter information to individual stimulators. A graphical user interface was designed to allow clinicians to specify temporal patterns and muscle stimulation parameters. We completed and tested a prototype of the hardware and communication software modules of the multichannel NMES system. The prototype system was first verified in nondisabled subjects for safety, and then tested in subjects with stroke for feasibility with assisting multijoint movements. Results showed that synergistic stimulation of multiple muscles in subjects with stroke improved performance of multijoint movements with more natural velocity profiles at elbow and shoulder and reduced acromion excursion due to compensatory trunk rotation. The network-based NMES system may provide an innovative solution that allows more physiological activation of multiple muscles in multijoint task training for patients with stroke.

  13. Active Noise Control in a Three Dimensional Enclosure Using Multichannel Fuzzy LMS Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Do [Dankook University (Korea, Republic of); Kim, Kyun Tae [Haitai Electronics R and D Cemter (Korea, Republic of)

    1998-05-01

    In this paper, active noise control(ANC) in an enclosure using multi-channel fuzzy LMS(MCFLMS) algorithm is considered. A new model for a secondary path transfer function, which has common acoustical poles that correspond to resonance properties of an enclosure, is used. Since this model requires far fewer variable parameters to represent secondary path transfer functions than those of conventional all-zero or pole and zero models, it reduces the computational complexity for an active noise control system. A MCFLMS algorithm, where the convergence coefficients of a multi-channel LMS(MCLMS) algorithm is derived by a fuzzy inference engine, is proposed. This algorithm shows better convergence than the existing MCLMS algorithms and it does not require pre-adjustment of convergence parameters, so it could be easily applied to practical ANC systems. Computer simulations and experiments were performed to show the effectiveness of the proposed algorithm in experimental enclosure. The proposed method shows better results in both computer simulations and experiments. (author). 14 refs., 10 figs., 2 tabs.

  14. Investigation of creating possibilities of multi-channel optical system with discrete angular field

    Science.gov (United States)

    Repin, Vladislav A.; Gorbunova, Elena V.; Chertov, Aleksandr N.

    2016-04-01

    Often, in practice, there is a problem of large areas of space viewing in order to fix certain parameters of moving objects. A multichannel optical-electronic monitoring system with a discrete angular field (or, as they say, artificial compound eye system) is an interesting variant to solve this problem. Such systems can be used for the analysis of various parameters of the objects, as an example for positioning of the object in wide annular zone. Using these systems we can get a wide angular field up to the full sphere due to a combination of a large number of elementary light detecting channels (like compound eyes of insects) and have a gain in the useful signal due to overlapping angular fields of channels. Currently, multichannel optoelectronic systems with discrete angular field are described and studied less than other up-to-date monitoring devices. But existing analogues are presented by experimental samples, which demonstrate the relevance of the research and design of such devices. This work presents a brief review of monitoring system with discrete angular field and theoretical description of proposed prototype. Results of experimental studies of mentioned prototype are presented as well.

  15. Open Ephys: an open-source, plugin-based platform for multichannel electrophysiology.

    Science.gov (United States)

    Siegle, Joshua H; López, Aarón Cuevas; Patel, Yogi A; Abramov, Kirill; Ohayon, Shay; Voigts, Jakob

    2017-02-07

    Closed-loop experiments, in which causal interventions are conditioned on the state of the system under investigation, have become increasingly common in neuroscience. Such experiments can have a high degree of explanatory power, but they require a precise implementation that can be difficult to replicate across laboratories. We sought to overcome this limitation by building open-source software that makes it easier to develop and share algorithms for closed-loop control. We created the Open Ephys GUI, an open-source platform for multichannel electrophysiology experiments. In addition to the standard 'open-loop' visualization and recording functionality, the GUI also includes modules for delivering feedback in response to events detected in the incoming data stream. Importantly, these modules can be built and shared as plugins, which makes it possible for users to extend the functionality of the GUI through a simple API, without having to understand the inner workings of the entire application. In combination with low-cost, open-source hardware for amplifying and digitizing neural signals, the GUI has been used for closed-loop experiments that perturb the hippocampal theta rhythm in a phase-specific manner. The Open Ephys GUI is the first widely used application for multichannel electrophysiology that leverages a plugin-based workflow. We hope that it will lower the barrier to entry for electrophysiologists who wish to incorporate real-time feedback into their research.

  16. A Comparative Study on LUT and Accumulator Radix-4 Based Multichannel RNS FIR Filter Architectures

    Directory of Open Access Journals (Sweden)

    Britto Pari. J

    2014-05-01

    Full Text Available In this paper, a comparative study of two architectures proposed for multichannel reconfigurable FIR filter are performed in terms of complexity and speed. The proposed architectures, viz, dual port memory based LUT multiplier and accumulator based radix-4 multiplier architectures, are designed to reduce the complexity and to improve the speed of operation of multiplier used in multichannel reconfigurable FIR filter. Both the architectures accepts residues of given binary input in which the 3n-bit binary input is converted into three residues using binary to Residue Number System (RNS converter, and then processed in three FIR sub filters constructed in direct form. The reconfigurable structure is achieved by combining Power of Two (PoT FIR sub modules and altering the filter taps based on select signals. The proposed designs can be realized up to 20-taps and has been tested for 4, 8, 16 and 20 taps. The architectures have been realized in Verilog HDL and synthesized using Altera FPGA device Stratix II EP2S15F672C5. The performance comparison of two architectures shows that dual port memory based LUT multiplier architecture significantly reduces the area by 20% and accumulator based Radix-4 multiplier increases the speed by 90% regardless of the number of taps.

  17. A Multi-Channel Salience Based Detail Exaggeration Technique for 3D Relief Surfaces

    Institute of Scientific and Technical Information of China (English)

    Yong-Wei Miao; Jie-Qing Feng; Jin-Rong Wang; Renato Pajarola

    2012-01-01

    Visual saliency can always persuade the viewer's visual attention to fine-scale mesostructure of 3D complex shapes.Owing to the multi-channel salience measure and salience-domain shape modeling technique,a novel visual saliency based shape depiction scheme is presented to exaggerate salient geometric details of the underlying relief surface.Our multi-channel salience measure is calculated by combining three feature maps,i.e.,the O-order feature map of local height distribution,the 1-order feature map of normal difference,and the 2-order feature map of mean curvature variation.The original relief surface is firstly manipulated by a salience-domain enhancement function,and the detail exaggeration surface can then be obtained by adjusting the surface normals of the original surface as the corresponding final normals of the manipulated surface.The advantage of our detail exaggeration technique is that it can adaptively alter the shading of the original shape to reveal visually salient features whilst keeping the desired appearance unimpaired.The experimental results demonstrate that our non-photorealistic shading scheme can enhance the surface mesostructure effectively and thus improving the shape depiction of the relief surfaces.

  18. A 12-bit SAR ADC integrated on a multichannel silicon drift detector readout IC

    Science.gov (United States)

    Schembari, F.; Bellotti, G.; Fiorini, C.

    2016-07-01

    A 12-bit analog-to-digital converter (ADC) addressed to Silicon-Drift Detectors (SDDs) multichannel readout ASICs for X- and gamma-ray applications is presented. Aiming at digitizing output multiplexed data from the upstream analog filters banks, the converter must ensure 11-bit accuracy and a sampling frequency of about 5 MS/s. The ADC architecture is the charge-redistribution (CR) successive-approximation register (SAR). A fully differential topology has also been chosen for better rejection of common-mode noise and disturbances. The internal DAC is made of binary-scaled capacitors, whose bottom plates are switched by the SAR logic to perform the binary search of the analog input value by means of the monotonic switching scheme. The A/D converter is integrated on SFERA, a multichannel ASIC fabricated in a standard CMOS 0.35 μm 3.3 V technology and it occupies an area of 0.42 mm2. Simulated static performance shows monotonicity over the whole input-output characteristic. The description of the circuit topology and of inner blocks architectures together with the experimental characterization is here presented.

  19. SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals

    Science.gov (United States)

    Xiong, Jiping; Cai, Lisang; Wang, Fei; He, Xiaowei

    2017-01-01

    Although wrist-type photoplethysmographic (hereafter referred to as WPPG) sensor signals can measure heart rate quite conveniently, the subjects’ hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise. PMID:28273818

  20. SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals

    Directory of Open Access Journals (Sweden)

    Jiping Xiong

    2017-03-01

    Full Text Available Although wrist-type photoplethysmographic (hereafter referred to as WPPG sensor signals can measure heart rate quite conveniently, the subjects’ hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise.

  1. A Non-Invasive Multichannel Hybrid Fiber-Optic Sensor System for Vital Sign Monitoring

    Science.gov (United States)

    Fajkus, Marcel; Nedoma, Jan; Martinek, Radek; Vasinek, Vladimir; Nazeran, Homer; Siska, Petr

    2017-01-01

    In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG). The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS). The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person’s chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field. PMID:28075341

  2. Optimized Multichannel Filter Bank with Flat Frequency Response for Texture Segmentation

    Science.gov (United States)

    Kachouie, Nezamoddin N.; Alirezaie, Javad

    2005-12-01

    Previous approaches to texture analysis and segmentation use multichannel filtering by applying a set of filters in the frequency domain or a set of masks in the spatial domain. This paper presents two new texture segmentation algorithms based on multichannel filtering in conjunction with neural networks for feature extraction and segmentation. The features extracted by Gabor filters have been applied for image segmentation and analysis. Suitable choices of filter parameters and filter bank coverage in the frequency domain to optimize the filters are discussed. Here we introduce two methods to optimize Gabor filter bank. First, a Gabor filter bank with a flat response is implemented and the optimal feature dimension is extracted by competitive networks. Second, a subset of Gabor filter bank is selected to compose the best discriminative filters, so that each filter in this small set can discriminate a pair of textures in a given image. In both approaches, multilayer perceptrons are employed to segment the extracted features. The comparisons of segmentation results generated using the proposed methods and previous research using Gabor, discrete cosine transform (DCT), and Laws filters are presented. Finally, the segmentation results generated by applying the optimized filter banks to textured images are presented and discussed.

  3. Multichannel matching pursuit of MEG signals for discriminative oscillation pattern detection in depression.

    Science.gov (United States)

    Lu, Qing; Jiang, Haiteng; Luo, Guoping; Han, Yinglin; Yao, Zhijian

    2013-05-01

    Magnetoencephalography (MEG) power topography may be useful for obtaining discriminative brain activity patterns that can distinguish depressed patients from healthy control subjects at the individual level. However, the application is still limited due to the lack of adequate analysis strategies to remove artifacts from the MEG signals. In this study, the multichannel matching pursuit (MMP) method was designed; in this technique, a linear decomposition method that provides components by iteratively reanalysing a residual signal after removing previously found components,. Forty-four subjects, half depressed patients and half healthy subjects, were recruited for MEG scanning whilst watching a video of sad faces. MMP was implemented to manage multichannel, multi-trial MEG signals. The representative post-MMP analysis signals were utilised to calculate the power topography over the whole brain and designed as inputs for a Support Vector Machine (SVM) classifier. A statistically significant discriminative accuracy of 86% (p=0.002) after a permutation test was achieved. Comparing the system classification performance to that of the ensemble averaging method and the established Independent Component Analysis (ICA), we demonstrated the ability of MMP to represent critical MEG information and, in turn, to mark the abnormality of oscillatory activities under negative stimuli using images of sad faces.

  4. Optimized Multichannel Filter Bank with Flat Frequency Response for Texture Segmentation

    Directory of Open Access Journals (Sweden)

    Kachouie Nezamoddin N

    2005-01-01

    Full Text Available Previous approaches to texture analysis and segmentation use multichannel filtering by applying a set of filters in the frequency domain or a set of masks in the spatial domain. This paper presents two new texture segmentation algorithms based on multichannel filtering in conjunction with neural networks for feature extraction and segmentation. The features extracted by Gabor filters have been applied for image segmentation and analysis. Suitable choices of filter parameters and filter bank coverage in the frequency domain to optimize the filters are discussed. Here we introduce two methods to optimize Gabor filter bank. First, a Gabor filter bank with a flat response is implemented and the optimal feature dimension is extracted by competitive networks. Second, a subset of Gabor filter bank is selected to compose the best discriminative filters, so that each filter in this small set can discriminate a pair of textures in a given image. In both approaches, multilayer perceptrons are employed to segment the extracted features. The comparisons of segmentation results generated using the proposed methods and previous research using Gabor, discrete cosine transform (DCT, and Laws filters are presented. Finally, the segmentation results generated by applying the optimized filter banks to textured images are presented and discussed.

  5. Multichannel Filtered-X Error Coded Affine Projection-Like Algorithm with Evolving Order

    Directory of Open Access Journals (Sweden)

    J. G. Avalos

    2017-01-01

    Full Text Available Affine projection (AP algorithms are commonly used to implement active noise control (ANC systems because they provide fast convergence. However, their high computational complexity can restrict their use in certain practical applications. The Error Coded Affine Projection-Like (ECAP-L algorithm has been proposed to reduce the computational burden while maintaining the speed of AP, but no version of this algorithm has been derived for active noise control, for which the adaptive structures are very different from those of other configurations. In this paper, we introduce a version of the ECAP-L for single-channel and multichannel ANC systems. The proposed algorithm is implemented using the conventional filtered-x scheme, which incurs a lower computational cost than the modified filtered-x structure, especially for multichannel systems. Furthermore, we present an evolutionary method that dynamically decreases the projection order in order to reduce the dimensions of the matrix used in the algorithm’s computations. Experimental results demonstrate that the proposed algorithm yields a convergence speed and a final residual error similar to those of AP algorithms. Moreover, it achieves meaningful computational savings, leading to simpler hardware implementation of real-time ANC applications.

  6. High-speed microstrip multi-anode multichannel plate detector system

    Science.gov (United States)

    Riedo, Andreas; Tulej, Marek; Rohner, Urs; Wurz, Peter

    2017-04-01

    High-speed detector systems with high dynamic range and pulse width characteristics in the sub-nanosecond regime are mandatory for high resolution and highly sensitive time-of-flight mass spectrometers. Typically, for a reasonable detector area, an impedance-matched anode design is necessary to transmit the registered signal fast and distortion-free from the anode to the signal acquisition system. In this report, a high-speed microstrip multi-anode multichannel plate detector is presented and discussed. The anode consists of four separate active concentric anode segments allowing a simultaneous readout of signal with a dynamic range of about eight orders of magnitude. The impedance matched anode segments show pulse width of about 250 ps, measured at full width at half maximum, and rise time of ˜170 ps, measured with an oscilloscope with a sampling rate of 20 GS/s and 4 GHz analogue bandwidth. The usage of multichannel plates as signal amplifier allowed the design of a lightweight, low power consuming, and compact detector system, suitable, e.g., for the integration into space instrumentation or portable systems where size, weight, and power consumption are limited parameters.

  7. A multi-channel fully differential programmable integrated circuit for neural recording application

    Science.gov (United States)

    Yun, Gui; Xu, Zhang; Yuan, Wang; Ming, Liu; Weihua, Pei; Kai, Liang; Suibiao, Huang; Bin, Li; Hongda, Chen

    2013-10-01

    A multi-channel, fully differential programmable chip for neural recording application is presented. The integrated circuit incorporates eight neural recording amplifiers with tunable bandwidth and gain, eight 4th-order Bessel switch capacitor filters, an 8-to-1 analog time-division multiplexer, a fully differential successive approximation register analog-to-digital converter (SAR ADC), and a serial peripheral interface for communication. The neural recording amplifier presents a programmable gain from 53 dB to 68 dB, a tunable low cut-off frequency from 0.1 Hz to 300 Hz, and 3.77 μVrms input-referred noise over a 5 kHz bandwidth. The SAR ADC digitizes signals at maximum sampling rate of 20 kS/s per channel and achieves an ENOB of 7.4. The integrated circuit is designed and fabricated in 0.18-μm CMOS mix-signal process. We successfully performed a multi-channel in-vivo recording experiment from a rat cortex using the neural recording chip.

  8. Cross contrast multi-channel image registration using image synthesis for MR brain images.

    Science.gov (United States)

    Chen, Min; Carass, Aaron; Jog, Amod; Lee, Junghoon; Roy, Snehashis; Prince, Jerry L

    2017-02-01

    Multi-modal deformable registration is important for many medical image analysis tasks such as atlas alignment, image fusion, and distortion correction. Whereas a conventional method would register images with different modalities using modality independent features or information theoretic metrics such as mutual information, this paper presents a new framework that addresses the problem using a two-channel registration algorithm capable of using mono-modal similarity measures such as sum of squared differences or cross-correlation. To make it possible to use these same-modality measures, image synthesis is used to create proxy images for the opposite modality as well as intensity-normalized images from each of the two available images. The new deformable registration framework was evaluated by performing intra-subject deformation recovery, intra-subject boundary alignment, and inter-subject label transfer experiments using multi-contrast magnetic resonance brain imaging data. Three different multi-channel registration algorithms were evaluated, revealing that the framework is robust to the multi-channel deformable registration algorithm that is used. With a single exception, all results demonstrated improvements when compared against single channel registrations using the same algorithm with mutual information.

  9. Randomised multichannel singular spectrum analysis of the 20th century climate data

    Directory of Open Access Journals (Sweden)

    Teija Seitola

    2015-12-01

    Full Text Available In this article, we introduce a new algorithm called randomised multichannel singular spectrum analysis (RMSSA, which is a generalisation of the traditional multichannel singular spectrum analysis (MSSA into problems of arbitrarily large dimension. RMSSA consists of (1 a dimension reduction of the original data via random projections, (2 the standard MSSA step and (3 a recovery of the MSSA eigenmodes from the reduced space back to the original space. The RMSSA algorithm is presented in detail and additionally we show how to integrate it with a significance test based on a red noise null-hypothesis by Monte-Carlo simulation. Finally, RMSSA is applied to decompose the 20th century global monthly mean near-surface temperature variability into its low-frequency components. The decomposition of a reanalysis data set and two climate model simulations reveals, for instance, that the 2–6 yr variability centred in the Pacific Ocean is captured by all the data sets with some differences in statistical significance and spatial patterns.

  10. Multi-Channel neurodegenerative pattern analysis and its application in Alzheimer's disease characterization.

    Science.gov (United States)

    Liu, Sidong; Cai, Weidong; Wen, Lingfeng; Feng, David Dagan; Pujol, Sonia; Kikinis, Ron; Fulham, Michael J; Eberl, Stefan

    2014-09-01

    Neuroimaging has played an important role in non-invasive diagnosis and differentiation of neurodegenerative disorders, such as Alzheimer's disease and Mild Cognitive Impairment. Various features have been extracted from the neuroimaging data to characterize the disorders, and these features can be roughly divided into global and local features. Recent studies show a tendency of using local features in disease characterization, since they are capable of identifying the subtle disease-specific patterns associated with the effects of the disease on human brain. However, problems arise if the neuroimaging database involved multiple disorders or progressive disorders, as disorders of different types or at different progressive stages might exhibit different degenerative patterns. It is difficult for the researchers to reach consensus on what brain regions could effectively distinguish multiple disorders or multiple progression stages. In this study we proposed a Multi-Channel pattern analysis approach to identify the most discriminative local brain metabolism features for neurodegenerative disorder characterization. We compared our method to global methods and other pattern analysis methods based on clinical expertise or statistics tests. The preliminary results suggested that the proposed Multi-Channel pattern analysis method outperformed other approaches in Alzheimer's disease characterization, and meanwhile provided important insights into the underlying pathology of Alzheimer's disease and Mild Cognitive Impairment.

  11. Development of MATLAB software to control data acquisition from a multichannel systems multi-electrode array.

    Science.gov (United States)

    Messier, Erik

    2016-08-01

    A Multichannel Systems (MCS) microelectrode array data acquisition (DAQ) unit is used to collect multichannel electrograms (EGM) from a Langendorff perfused rabbit heart system to study sudden cardiac death (SCD). MCS provides software through which data being processed by the DAQ unit can be displayed and saved, but this software's combined utility with MATLAB is not very effective. MCSs software stores recorded EGM data in a MathCad (MCD) format, which is then converted to a text file format. These text files are very large, and it is therefore very time consuming to import the EGM data into MATLAB for real-time analysis. Therefore, customized MATLAB software was developed to control the acquisition of data from the MCS DAQ unit, and provide specific laboratory accommodations for this study of SCD. The developed DAQ unit control software will be able to accurately: provide real time display of EGM signals; record and save EGM signals in MATLAB in a desired format; and produce real time analysis of the EGM signals; all through an intuitive GUI.

  12. Integrated Time and Phase Synchronization Strategy for a Multichannel Spaceborne-Stationary Bistatic SAR System

    Directory of Open Access Journals (Sweden)

    Feng Hong

    2016-07-01

    Full Text Available The spatial separation of the transmitter and receiver in Bistatic Synthetic Aperture Radar (BiSAR makes it a promising and useful supplement to a classical Monostatic SAR system (MonoSAR. This paper proposes a novel integrated time and phase synchronization strategy for a multichannel spaceborne-stationary BiSAR system. Firstly, the time synchronization strategy is proposed, which includes Pulse Repetition Frequency (PRF generation under noisy conditions, multichannel calibration and the alignment of the recorded data with the orbital data. Furthermore, the phase synchronization strategy, which fully considers the deteriorative factors in the BiSAR configuration, is well studied. The contribution of the phase synchronization strategy includes two aspects: it not only compensates the phase error, but also improves the Signal to Noise Ratio (SNR of the obtained signals. Specifically, all direct signals on different PRF time can be reconstructed with the shift and phase compensation operation using a reference signal. Besides, since the parameters of the reference signal can be estimated only once using the selected practical direct signal and a priori information, the processing complexity is well reduced. Final imaging results with and without compensation for real data are presented to validate the proposed synchronization strategy.

  13. Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester tissue engineered nerve guides.

    Science.gov (United States)

    Tran, Richard T; Choy, Wai Man; Cao, Hung; Qattan, Ibrahim; Chiao, Jung-Chih; Ip, Wing Yuk; Yeung, Kelvin Wai Kwok; Yang, Jian

    2014-08-01

    Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering.

  14. ANALYSIS OF THE FLOW OF GOODS IN NEW FORMS OF MULTICHANNEL SALES

    Directory of Open Access Journals (Sweden)

    Roman Domański

    2016-12-01

    Full Text Available New distribution channels have been growing dynamically in recent years as a result of the ever-present Internet, which offers a number of new retail forms that enable communication between individual market participants. The recent growth of trade has been identified chiefly with the dynamic development of e-commerce sales. The purpose of the article is to define the characteristic features of each new distribution channel and the guidelines referring to the economics of the flow of goods in a logistics system. The conclusions have been based on the analysis of literature and observed business practices. Today, further growth of commercial exchange is linked to the introduction of new forms of multichannel, crosschannel and omnichannel sales. New distribution channels have not been precisely defined to date. Presently executed undertakings which employ multichannel sales are more or less pioneering pilot projects. The further functioning of new distribution channels will depend on economic calculations. In these terms, analysing the effectiveness of individual new forms of distribution channels will be of key significance. The term "effectiveness of a distribution channel" is linked to the size of a lot of flowing goods. Classic methods of specifying lot size assume stable conditions of the environment in which a distribution channel works. Today, however, the market situation is unstable and subject to continuous changes which occur very quickly.

  15. All That Unplowed Sea

    Science.gov (United States)

    MOSAIC, 1975

    1975-01-01

    Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)

  16. The Caspian Sea Environment

    Science.gov (United States)

    Kostianoy, Andrey; Kosarev, A.

    The systematic description of the knowledge accumulated on the physical oceanography, marine chemistry and pollution, and marine biology of the Caspian Sea forms the basis of this book. It presents the principal characteristic features of the environmental conditions of the sea and their changes in the second half of the 20th century. At present, the principal problems of the Caspian Sea are related to the interannual sea level changes and their forecast and to the estimation of the intensity of the chemical pollution of the sea and its impact upon the biota.

  17. SEA and planning

    DEFF Research Database (Denmark)

    Stoeglehner, G.; Brown, A.L.; Kørnøv, Lone

    2009-01-01

    As the field of strategic environmental assessment (SEA) has matured, the focus has moved from the development of legislation, guidelines and methodologies towards improving the effectiveness of SEA. Measuring and of course achieving effectiveness is both complex and challenging. This paper...... suggests that SEA professionals need to consider 'democratic effectiveness' as well as 'environmental effectiveness' in both 'direct' and 'indirect' outputs. The effectiveness of SEA depends critically on the context within which SEA legislation and guidelines are understood and implemented......, and the relationship of the SEA to the planning activity itself. This paper focuses on the influence that planners have in these implementation processes, postulating the hypothesis that these are key players in achieving effectiveness in SEA. Based upon implementation theory and empirical experience, the paper...

  18. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  19. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  20. Sea piracy and law of the sea

    OpenAIRE

    Hanif, Muhammad Tahir

    2010-01-01

    As the sea become world’s largest source to trade between the nations during the last few decades. Of course there are lots of problems in this regards when we are using the sea on such a large scale. The problem of piracy is most dangerous problems, among the all problems of the sea at the same time. Nations are trying to control this crime individually and collectively but the problem is still on its peak. Lots of international and national laws and conventions are held in this ...

  1. A new implementation of multichannel radiochromic film dosimetry; Una nueva implementacion del analisis multicanal para la dosimetria mediante peliculas radiocromicas

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez, C.; Martin Martin, G.; Bermudez Luna, R.; Lopez Fernandez, A.; Tores Olombrada, M. V. de

    2014-07-01

    The aims of this paper are to carry out a new implementation of the multichannel radiochromic film dosimetry (Micke A, Lewis D, Yu X. Multichannel film dosimetry with nonuniformity correction. Med Phys 2011;38:2523-34), to quantify the variation in gamma index as compared to the single channel film dosimetry, and to determine if the procedure achieves similar results by means of a different scanner that the one used by Micke et al. Radiochromic EBT2 films and a Microtek 9000 XL scanner were used. Our procedure simplifies the system calibration splitting it into two factors, manufactured batch and digitalization specific. Absorbed dose spatial distributions from an open radiotherapy beam without any modulation and 20 IMRT treatments were determined. Their gamma index maps were calculated and a comparison of the results from single channel and multichannel dosimetry was performed. A 5% mean increase in concordance was obtained by using the multichannel film dosimetry. Our results are similar to those reported by Micke et al. even though we are using a different scanner. (Author)

  2. Multi-channel non-return-to-zero format to return-to-zero format conversion with duplicate output

    Science.gov (United States)

    Yu, Yu; Zhang, Xinliang; Huang, Dexiu

    2010-12-01

    We demonstrate multi-channel regenerative non-return-to-zero (NRZ) to return-to-zero (RZ) conversions with tunable output pulse-width and single-to-dual function, using a phase modulator and an array waveguide grating (AWG). Transmission and bit error ratio (BER) show a good performance for the converted RZ signal compared with conventional one.

  3. Surface Clutter Suppression Techniques Applied to P-band Multi-Channel SAR Ice Sounder Data from East Antarctica

    DEFF Research Database (Denmark)

    Lin, Chung-Chi; Bekaert, David; Gebert, Nicolas

    ., Lausanne, developed and built the radiator-elements of the enhanced POLARIS. Several datasets were acquired in the multi-channel configuration during the Feb. 2011 campaign over East Antarctica. The POLARIS instrument will be briefly introduced, followed by an overview of the sounding campaign. Finally...

  4. Task Dependent Prefrontal Dysfunction in Persons with Asperger's Disorder Investigated with Multi-Channel Near-Infrared Spectroscopy

    Science.gov (United States)

    Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Hashimoro, Ryuichiro; Kanai, Chieko; Watanabe, Hiromi; Yamasue, Hidenori; Kawakubo, Yuki; Kato, Nobumasa

    2011-01-01

    Dysfunction of the prefrontal cortex has been previously reported in individuals with Asperger's disorder. In the present study, we used multi-channel near-infrared spectroscopy (NIRS) to detect changes in the oxygenated hemoglobin concentration ([oxy-Hb]) during two verbal fluency tasks. The subjects were 20 individuals with Asperger's disorder…

  5. Reconstruction of band-limited signals from multichannel and periodic nonuniform samples in the linear canonical transform domain

    Science.gov (United States)

    Wei, Deyun; Ran, Qiwen; Li, Yuanmin

    2011-09-01

    Linear canonical transforms (LCTs) are a family of integral transforms with wide application in optical, acoustical, electromagnetic, and other wave propagation problems. This paper addresses the problem of signal reconstruction from multichannel and periodic nonuniform samples in the LCT domain. Firstly, the multichannel sampling theorem (MST) for band-limited signals with the LCT is proposed based on multichannel system equations, which is the generalization of the well-known sampling theorem for the LCT. We consider the problem of reconstructing the signal from its samples which are acquired using a multichannel sampling scheme. For this purpose, we propose two alternatives. The first scheme is based on the conventional Fourier series and inverse LCT operation. The second is based on the conventional Fourier series and inverse Fourier transform (FT) operation. Moreover, the classical Papoulis MST in FT domain is shown to be special case of the achieved results. Since the periodic nonuniformly sampled signal in the LCT has valuable applications, the reconstruction expression for the periodic nonuniformly sampled signal has been then obtained by using the derived MST and the specific space-shifting property of the LCT. Last, the potential applications of the MST are presented to show the advantage of the theory.

  6. Experimental researches and comparison on aerodynamic parameters and cleaning efficiency of multi-level multi-channel cyclone

    Directory of Open Access Journals (Sweden)

    Aleksandras Chlebnikovas

    2015-10-01

    Full Text Available Multi-level multi-channel cyclone – the lately designed air cleaning device that can remove ultra-fine 20 μm particulatematter (PM from dusted air and reach over 95% of the overall cleaning efficiency. Multi-channel cyclone technology is based on centrifugal forces and has the resulting additional filtering process operation. Multi-level structure of cyclone allows to achieve higher air flow cleaning capacity at the same dimensions of the device, thus saving installation space required for the job, production and operating costs. Studies have examined the air flow parameters change in one–, two– and three–levels multichannel cyclone. These constructions differ according to the productivity of cleaned air under the constant peripheral and transitional (50/50 case air flow relations. Accordance with the results of air flow dynamics – velocity distribution of multi-channel cyclone, aerodynamic resistance and efficiency can be judged on the flow turbulence, the flow channel cross-section and select the most appropriate application. Cleaning efficiency studies were carried out using fine granite and wood ashes PM. The maximum cleaning efficiency was 93.3%, at an average of 4.5 g/m3, the aerodynamic resistance was equal to 1525 Pa.

  7. Modernization of multichannel gamma-ray spectrometer at the second horizontal channel of reactor WWR-M

    CERN Document Server

    Berko, V J; Lyibman, V A

    2003-01-01

    Fast anti coincidence scheme with one privileged entrance has been developed, made and adjusted for underestimation of background distribution under full absorption peaks of gamma-ray by transformation one track of multichannel pair gamma-ray spectrometer into anticompton spectrometer. Obtained suppression factor of background is from 1,5 to 4, depending on gamma-ray energy.

  8. Task Dependent Prefrontal Dysfunction in Persons with Asperger's Disorder Investigated with Multi-Channel Near-Infrared Spectroscopy

    Science.gov (United States)

    Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Hashimoro, Ryuichiro; Kanai, Chieko; Watanabe, Hiromi; Yamasue, Hidenori; Kawakubo, Yuki; Kato, Nobumasa

    2011-01-01

    Dysfunction of the prefrontal cortex has been previously reported in individuals with Asperger's disorder. In the present study, we used multi-channel near-infrared spectroscopy (NIRS) to detect changes in the oxygenated hemoglobin concentration ([oxy-Hb]) during two verbal fluency tasks. The subjects were 20 individuals with Asperger's disorder…

  9. Multichannel analyzer using a card of data acquisition; Analizador multicanal empleando una tarjeta de adquisicion de datos

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Ch, G.; Hernandez D, V. M.; Vega C, H. R., E-mail: gamalielmch@gmail.com [Universidad Autonoma de Zacatecas, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    In this work is described the progress of a multichannel analyzer, using the card of data acquisition PCI-MIO-16E-4 and its programming in the LabVIEW ambient. The system proposed capture the signal to the amplifier exit to a rate of sampling of 500 k sps and a maximum resolution of 12 bits; later on is carried out the processing by means of programming, using virtual instruments that carry out the tasks of a classical multichannel analyzer. The height of the pulse is corresponding to the interaction energy of the radiation with the detector; a locality is assigned in a data arrangement that corresponds to the amplitude in voltage, taking into account that the position of the incident pulses is known inside the arrangement; a differential spectrum of pulse height was realized. The developed program has conversion gain controls, voltage intervals, live time of count, sampling rate, detection threshold and reports generation; as well as the real time indicators, total counts, channel with major and minor counts number. Comparisons with a commercial multichannel analyzer were realized using a Cs-137 source, the spectrum obtained with the developed multichannel analyzer has the characteristic form of the photopeak, the backscattering peak, the plateau and the border Compton; besides an efficiency and similar resolution. (Author)

  10. New insights on the subsidence of the Ganges-Brahmaputra Delta Plain by using 2D multichannel seismic data, gravity and flexural modeling, BanglaPIRE Project

    Science.gov (United States)

    Grall, C.; Pickering, J.; Steckler, M. S.; Spiess, V.; Seeber, L.; Paola, C.; Goodbred, S. L., Jr.; Palamenghi, L.; Schwenk, T.

    2015-12-01

    Deltas can subside very fast, yet many deltas remain emergent over geologic time. A large sediment input is often enough to compensate for subsidence and rising sea level to keep many deltas at sea level. This implies a balance between subsidence and sedimentation, both of which may, however, be controlled by independent factors such as sediment supply, tectonic loads and sea-level change. We here examine the subsidence of the Ganges-Brahmaputra Delta (GBD). Located in the NE boundary of the Indian-Eurasian collision zone, the GBD is surrounded by active uplifts (Indo-Burma Fold Belt and the Shillong Massif). The pattern of subsidence from these tectonic loads can strongly vary depending on both loads and lithospheric flexural rigidity, both of which can vary in space and time. Sediment cover changes both the lithostatic pressure and the thermal properties and thus the rigidity of the lithosphere. While sediments are deposited cold, they also insulate the lithosphere, acting as a thermal blanket to increase lower crustal temperatures. These effects are a function of sedimentation rates and may be more important where the lithosphere is thin. At the massive GBD the impact of sedimentation should be considered for properly constraining flexural subsidence. The flexural rigidity of the lithosphere is here modeled by using a yield-stress envelope based on a thermomechanic model that includes geothermal changes associated with sedimentation. Models are constrained by using two different data sets, multichannel seismic data correlated to borehole stratigraphy, and gravity data. This approach allows us to determine the Holocene regional distribution of subsidence from the Hinge Zone to the Bengal Fan and the mass-anomalies associated with the flexural loading. Different end-member scenarios are explored for reproducing the observed land tilting and gravity anomalies. For all scenarios considered, data can be reproduced only if we consider an extremely weak lithosphere and

  11. Calibration approach and plan for the sea and land surface temperature radiometer

    Science.gov (United States)

    Smith, David L.; Nightingale, Tim J.; Mortimer, Hugh; Middleton, Kevin; Edeson, Ruben; Cox, Caroline V.; Mutlow, Chris T.; Maddison, Brian J.; Coppo, Peter

    2014-01-01

    The sea and land surface temperature radiometer (SLSTR) to be flown on the European Space Agency's (ESA) Sentinel-3 mission is a multichannel scanning radiometer that will continue the 21 year dataset of the along-track scanning radiometer (ATSR) series. As its name implies, measurements from SLSTR will be used to retrieve global sea surface temperatures to an uncertainty of SLSTR instrument, the infrared calibration sources, and the alignment equipment. The calibration rig has been commissioned and results of these tests will be presented. Finally, the authors will present the planning for the on-orbit monitoring and calibration activities to ensure that the calibration is maintained. These activities include vicarious calibration techniques that have been developed through previous missions and the deployment of ship-borne radiometers.

  12. Salish Sea Genetics - Salish Sea genetic inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Salish Sea comprises most of the Puget Sound water area. Marine species are generally assemblages of discrete populations occupying various ecological niches....

  13. An accelerated non-Gaussianity based multichannel predictive deconvolution method with the limited supporting region of filters

    Science.gov (United States)

    Li, Zhong-xiao; Li, Zhen-chun

    2016-09-01

    The multichannel predictive deconvolution can be conducted in overlapping temporal and spatial data windows to solve the 2D predictive filter for multiple removal. Generally, the 2D predictive filter can better remove multiples at the cost of more computation time compared with the 1D predictive filter. In this paper we first use the cross-correlation strategy to determine the limited supporting region of filters where the coefficients play a major role for multiple removal in the filter coefficient space. To solve the 2D predictive filter the traditional multichannel predictive deconvolution uses the least squares (LS) algorithm, which requires primaries and multiples are orthogonal. To relax the orthogonality assumption the iterative reweighted least squares (IRLS) algorithm and the fast iterative shrinkage thresholding (FIST) algorithm have been used to solve the 2D predictive filter in the multichannel predictive deconvolution with the non-Gaussian maximization (L1 norm minimization) constraint of primaries. The FIST algorithm has been demonstrated as a faster alternative to the IRLS algorithm. In this paper we introduce the FIST algorithm to solve the filter coefficients in the limited supporting region of filters. Compared with the FIST based multichannel predictive deconvolution without the limited supporting region of filters the proposed method can reduce the computation burden effectively while achieving a similar accuracy. Additionally, the proposed method can better balance multiple removal and primary preservation than the traditional LS based multichannel predictive deconvolution and FIST based single channel predictive deconvolution. Synthetic and field data sets demonstrate the effectiveness of the proposed method.

  14. Summer Arctic sea fog

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China' s First Arctic Expedition. Based on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind has its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form,which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.

  15. Design of a multi-channel free space optical interconnec-tion component

    Institute of Scientific and Technical Information of China (English)

    JIA Da-gong; ZHANG Pei-song; JING Wen-cai; TAN Jun; ZHANG Hong-xia; ZHANG Yi-mo

    2008-01-01

    A multi-channel free space optical interconnection component, fiber optic rotary joint, was designed using a Dove prism.When the Dove prism is rotated an angle of α around the longitudinal axis, the image rotates an angle of 2α. The opticalinterconnection component consists of the signal transmission system, Dove prim and driving mechanism. The planetarygears are used to achieve the speed ratio of 2:1 between the total optical interconnection component and the Dove prism.The C-lenses are employed to couple different optical signals in the signal transmission system. The coupling loss betweenthe receiving fiber of stationary part and the transmitting fiber of rotary part is measured.

  16. A Multi-Channel Method for Detecting Periodic Forced Oscillations in Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Follum, James D.; Tuffner, Francis K.

    2016-11-14

    Forced oscillations in electric power systems are often symptomatic of equipment malfunction or improper operation. Detecting and addressing the cause of the oscillations can improve overall system operation. In this paper, a multi-channel method of detecting forced oscillations and estimating their frequencies is proposed. The method operates by comparing the sum of scaled periodograms from various channels to a threshold. A method of setting the threshold to specify the detector's probability of false alarm while accounting for the correlation between channels is also presented. Results from simulated and measured power system data indicate that the method outperforms its single-channel counterpart and is suitable for real-world applications.

  17. Magnetic ordering and non-Fermi-liquid behavior in the multichannel Kondo-lattice model

    Science.gov (United States)

    Irkhin, Valentin Yu.

    2016-05-01

    Scaling equations for the Kondo lattice in the paramagnetic and magnetically ordered phases are derived to next-leading order with account of spin dynamics. The results are applied to describe various mechanisms of the non-Fermi-liquid (NFL) behavior in the multichannel Kondo-lattice model where a fixed point occurs in the weak-coupling region. The corresponding temperature dependences of electronic and magnetic properties are discussed. The model describes naturally formation of a magnetic state with soft boson mode and small moment value. An important role of Van Hove singularities in the magnon spectral function is demonstrated. The results are rather sensitive to the type of magnetic ordering and space dimensionality, the conditions for NFL behavior being more favorable in the antiferromagnetic and 2D cases.

  18. TAM Ⅲ -A New Generation Multichannel Microcalorimetric System from Thermometric for Use Within the Pharmaceutical Field

    Institute of Scientific and Technical Information of China (English)

    Dan Forsstr(o)m, Dr

    2003-01-01

    @@ Thermometric AB in Sweden, recently introduced TAM Ⅲ--a new generation multichannel microcalorimetric system. TAM Ⅲ can be used to study various phenomena in the pharmaceutical field such as stability and shelf life, compatibility screening, amorphicity and crystallinity and, polymorphism in terms of heat, heat flow and heat capacity. In a calorimetric experiment a sample is introduced into a reaction vessel, which is subsequently loaded into a calorimeter. The calorimeter is permanently immersed in a precision thermostat that controls the temperature of the calorimeter to within 0. 000001 ℃. The experimental conditions can be controlled by use of various auxiliary equipments. The heat flow caused by the sample is monitored continuously as function of time.

  19. Multichannel liquid-crystal-based wave-front corrector with modal influence functions.

    Science.gov (United States)

    Naumov, A F; Vdovin, G

    1998-10-01

    We report on a multichannel liquid-crystal-based wave-front corrector with smooth modal influence functions. The phase is controlled by application of spatially localized ac voltages to a distributed voltage divider formed by a liquid-crystal layer sandwiched between a high-conductance and a low-conductance electrode. The shape of the influence function depends on the control frequency and material parameters of the distributed voltage divider. We have experimentally realized a reflective modulator controlled by an array of 16 x 16 electrodes, providing phase control with an amplitude of approximately 16 pi at lambda =633 nm with a time constant of the order of tens of milliseconds. We experimentally demonstrated that the amplitude of each influence function can be controlled by change of the control voltage, whereas the width of the influence function is controlled by the frequency of the control voltage in a range of approximately 1 mm to the full width of the modulator aperture.

  20. Principle of Line Configuration and Monte-Carlo Simulation for Shared Multi-Channel System

    Institute of Scientific and Technical Information of China (English)

    MIAO Changyun; DAI Jufeng; BAI Zhihui

    2005-01-01

    Based on the steady-state solution of finite-state birth and death process, the principle of line configuration for shared multi-channel system is analyzed. Call congestion ratio equation and channel utilization ratio equation are deduced, and visualized data analysis is presented. The analy-sis indicates that, calculated with the proposed equations, the overestimate for call congestion ratio and channel utilization ratio can be rectified, and thereby the cost of channels can be saved by 20% in a small system.With MATLAB programming, line configuration methods are provided. In order to generally and intuitively show the dynamic running of the system, and to analyze,promote and improve it, the system is simulated using M/M/n/n/m queuing model and Monte-Carlo method. In addition, the simulation validates the correctness of the theoretical analysis and optimizing configuration method.