A multi-channel isolated power supply in non-equipotential circuit

Science.gov (United States)

Li, Xiang; Zhao, Bo-Wen; Zhang, Yan-Chi; Xie, Da

2018-04-01

A multi-channel isolation power supply is designed for the problems of different MOSFET or IGBT in the non-equipotential circuit in this paper. It mainly includes the square wave generation circuit, the high-frequency transformer and the three-terminal stabilized circuit. The first part is used to generate the 24V square wave, and as the input of the magnetic ring transformer. In the second part, the magnetic ring transformer consists of one input and three outputs to realize multi-channel isolation output. The third part can output different potential and realize non-equal potential function through the three-terminal stabilized chip. In addition, the multi-channel isolation power source proposed in this paper is Small size, high reliability and low price, and it is convenient for power electronic switches that operate on multiple different potentials. Therefore, the research on power supply of power electronic circuit has practical significance.

Flat Engineered Multichannel Reflectors

Directory of Open Access Journals (Sweden)

V. S. Asadchy

2017-09-01

Full Text Available 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 multichannel functional metasurfaces, which are able to control incoming and outgoing waves in a number of propagation directions simultaneously. In particular, we reveal a possibility to engineer multichannel reflectors. Under the assumption of reciprocity and energy conservation, we find that there exist three basic functionalities of such reflectors: specular, anomalous, and retroreflections. Multichannel response of a general flat reflector can be described by a combination of these functionalities. To demonstrate the potential of the introduced concept, we design and experimentally test three different multichannel reflectors: three- and five-channel retroreflectors and a three-channel power splitter. Furthermore, by extending the concept to reflectors supporting higher-order Floquet harmonics, we forecast the emergence of other multichannel flat devices, such as isolating mirrors, complex splitters, and multi-functional gratings.

Flat Engineered Multichannel Reflectors

Science.gov (United States)

Asadchy, V. S.; Díaz-Rubio, A.; Tcvetkova, S. N.; Kwon, D.-H.; Elsakka, A.; Albooyeh, M.; Tretyakov, S. A.

2017-07-01

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 multichannel functional metasurfaces, which are able to control incoming and outgoing waves in a number of propagation directions simultaneously. In particular, we reveal a possibility to engineer multichannel reflectors. Under the assumption of reciprocity and energy conservation, we find that there exist three basic functionalities of such reflectors: specular, anomalous, and retroreflections. Multichannel response of a general flat reflector can be described by a combination of these functionalities. To demonstrate the potential of the introduced concept, we design and experimentally test three different multichannel reflectors: three- and five-channel retroreflectors and a three-channel power splitter. Furthermore, by extending the concept to reflectors supporting higher-order Floquet harmonics, we forecast the emergence of other multichannel flat devices, such as isolating mirrors, complex splitters, and multi-functional gratings.

Measurements of intermediate-frequency electric and magnetic fields in households

Energy Technology Data Exchange (ETDEWEB)

Aerts, Sam, E-mail: sam.aerts@intec.ugent.be [Department of Information Technology, Ghent University/iMinds, iGent, Technologiepark-Zwijnaarde 15, B-9052 Ghent (Belgium); Calderon, Carolina [Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Valič, Blaž [Institute of Non-Ionizing Radiation (INIS), Pohorskega bataljona 215, Ljubljana 1000 (Slovenia); Maslanyj, Myron; Addison, Darren; Mee, Terry; Goiceanu, Cristian [Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Verloock, Leen; Van den Bossche, Matthias [Department of Information Technology, Ghent University/iMinds, iGent, Technologiepark-Zwijnaarde 15, B-9052 Ghent (Belgium); Gajšek, Peter [Institute of Non-Ionizing Radiation (INIS), Pohorskega bataljona 215, Ljubljana 1000 (Slovenia); Vermeulen, Roel [Institute for Risk Assessment Sciences, Department of Environmental Epidemiology, Utrecht University, Yalelaan 2, 3508 Utrecht (Netherlands); Röösli, Martin [Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, P.O. Box, 4002 Basel (Switzerland); University of Basel, Petersplatz 1, 4003 Basel (Switzerland); Cardis, Elisabeth [Barcelona Institute for Global Health (ISGlobal) and Municipal Institute of Medical Research (IMIM-Hospital del Mar), Doctor Aiguader, 88, 08003 Barcelona (Spain); Martens, Luc; Joseph, Wout [Department of Information Technology, Ghent University/iMinds, iGent, Technologiepark-Zwijnaarde 15, B-9052 Ghent (Belgium)

2017-04-15

Historically, assessment of human exposure to electric and magnetic fields has focused on the extremely-low-frequency (ELF) and radiofrequency (RF) ranges. However, research on the typically emitted fields in the intermediate-frequency (IF) range (300 Hz to 1 MHz) as well as potential effects of IF fields on the human body remains limited, although the range of household appliances with electrical components working in the IF range has grown significantly (e.g., induction cookers and compact fluorescent lighting). In this study, an extensive measurement survey was performed on the levels of electric and magnetic fields in the IF range typically present in residences as well as emitted by a wide range of household appliances under real-life circumstances. Using spot measurements, residential IF field levels were found to be generally low, while the use of certain appliances at close distance (20 cm) may result in a relatively high exposure. Overall, appliance emissions contained either harmonic signals, with fundamental frequencies between 6 kHz and 300 kHz, which were sometimes accompanied by regions in the IF spectrum of rather noisy, elevated field strengths, or much more capricious spectra, dominated by 50 Hz harmonics emanating far in the IF domain. The maximum peak field strengths recorded at 20 cm were 41.5 V/m and 2.7 A/m, both from induction cookers. Finally, none of the appliance emissions in the IF range exceeded the exposure summation rules recommended by the International Commission on Non-Ionizing Radiation Protection guidelines and the International Electrotechnical Commission (IEC 62233) standard at 20 cm and beyond (maximum exposure quotients EQ{sub E} 1.0 and {sub E}Q{sub H} 0.13). - Highlights: • Survey of residential electric and magnetic fields at intermediate frequencies (IF). • IF-EF and -MF emitted by 280 household appliances were characterised. • Strongest emitters were induction cookers, CFLs, LCD-TVs, and microwave ovens. • No

Measurements of intermediate-frequency electric and magnetic fields in households

International Nuclear Information System (INIS)

Aerts, Sam; Calderon, Carolina; Valič, Blaž; Maslanyj, Myron; Addison, Darren; Mee, Terry; Goiceanu, Cristian; Verloock, Leen; Van den Bossche, Matthias; Gajšek, Peter; Vermeulen, Roel; Röösli, Martin; Cardis, Elisabeth; Martens, Luc; Joseph, Wout

2017-01-01

Historically, assessment of human exposure to electric and magnetic fields has focused on the extremely-low-frequency (ELF) and radiofrequency (RF) ranges. However, research on the typically emitted fields in the intermediate-frequency (IF) range (300 Hz to 1 MHz) as well as potential effects of IF fields on the human body remains limited, although the range of household appliances with electrical components working in the IF range has grown significantly (e.g., induction cookers and compact fluorescent lighting). In this study, an extensive measurement survey was performed on the levels of electric and magnetic fields in the IF range typically present in residences as well as emitted by a wide range of household appliances under real-life circumstances. Using spot measurements, residential IF field levels were found to be generally low, while the use of certain appliances at close distance (20 cm) may result in a relatively high exposure. Overall, appliance emissions contained either harmonic signals, with fundamental frequencies between 6 kHz and 300 kHz, which were sometimes accompanied by regions in the IF spectrum of rather noisy, elevated field strengths, or much more capricious spectra, dominated by 50 Hz harmonics emanating far in the IF domain. The maximum peak field strengths recorded at 20 cm were 41.5 V/m and 2.7 A/m, both from induction cookers. Finally, none of the appliance emissions in the IF range exceeded the exposure summation rules recommended by the International Commission on Non-Ionizing Radiation Protection guidelines and the International Electrotechnical Commission (IEC 62233) standard at 20 cm and beyond (maximum exposure quotients EQ E 1.0 and E Q H 0.13). - Highlights: • Survey of residential electric and magnetic fields at intermediate frequencies (IF). • IF-EF and -MF emitted by 280 household appliances were characterised. • Strongest emitters were induction cookers, CFLs, LCD-TVs, and microwave ovens. • No emissions exceeded

Modeling high dimensional multichannel brain signals

KAUST Repository

Hu, Lechuan

2017-03-27

In this paper, our goal is to model functional and effective (directional) connectivity in network of multichannel brain physiological signals (e.g., electroencephalograms, local field potentials). The primary challenges here are twofold: first, there are major statistical and computational difficulties for modeling and analyzing high dimensional multichannel brain signals; second, there is no set of universally-agreed measures for characterizing connectivity. To model multichannel brain signals, our approach is to fit a vector autoregressive (VAR) model with sufficiently high order so that complex lead-lag temporal dynamics between the channels can be accurately characterized. However, such a model contains a large number of parameters. Thus, we will estimate the high dimensional VAR parameter space by our proposed hybrid LASSLE method (LASSO+LSE) which is imposes regularization on the first step (to control for sparsity) and constrained least squares estimation on the second step (to improve bias and mean-squared error of the estimator). Then to characterize connectivity between channels in a brain network, we will use various measures but put an emphasis on partial directed coherence (PDC) in order to capture directional connectivity between channels. PDC is a directed frequency-specific measure that explains the extent to which the present oscillatory activity in a sender channel influences the future oscillatory activity in a specific receiver channel relative all possible receivers in the network. Using the proposed modeling approach, we have achieved some insights on learning in a rat engaged in a non-spatial memory task.

Modeling high dimensional multichannel brain signals

KAUST Repository

Hu, Lechuan; Fortin, Norbert; Ombao, Hernando

2017-01-01

In this paper, our goal is to model functional and effective (directional) connectivity in network of multichannel brain physiological signals (e.g., electroencephalograms, local field potentials). The primary challenges here are twofold: first, there are major statistical and computational difficulties for modeling and analyzing high dimensional multichannel brain signals; second, there is no set of universally-agreed measures for characterizing connectivity. To model multichannel brain signals, our approach is to fit a vector autoregressive (VAR) model with sufficiently high order so that complex lead-lag temporal dynamics between the channels can be accurately characterized. However, such a model contains a large number of parameters. Thus, we will estimate the high dimensional VAR parameter space by our proposed hybrid LASSLE method (LASSO+LSE) which is imposes regularization on the first step (to control for sparsity) and constrained least squares estimation on the second step (to improve bias and mean-squared error of the estimator). Then to characterize connectivity between channels in a brain network, we will use various measures but put an emphasis on partial directed coherence (PDC) in order to capture directional connectivity between channels. PDC is a directed frequency-specific measure that explains the extent to which the present oscillatory activity in a sender channel influences the future oscillatory activity in a specific receiver channel relative all possible receivers in the network. Using the proposed modeling approach, we have achieved some insights on learning in a rat engaged in a non-spatial memory task.

Modeling High-Dimensional Multichannel Brain Signals

KAUST Repository

Hu, Lechuan

2017-12-12

Our goal is to model and measure functional and effective (directional) connectivity in multichannel brain physiological signals (e.g., electroencephalograms, local field potentials). The difficulties from analyzing these data mainly come from two aspects: first, there are major statistical and computational challenges for modeling and analyzing high-dimensional multichannel brain signals; second, there is no set of universally agreed measures for characterizing connectivity. To model multichannel brain signals, our approach is to fit a vector autoregressive (VAR) model with potentially high lag order so that complex lead-lag temporal dynamics between the channels can be captured. Estimates of the VAR model will be obtained by our proposed hybrid LASSLE (LASSO + LSE) method which combines regularization (to control for sparsity) and least squares estimation (to improve bias and mean-squared error). Then we employ some measures of connectivity but put an emphasis on partial directed coherence (PDC) which can capture the directional connectivity between channels. PDC is a frequency-specific measure that explains the extent to which the present oscillatory activity in a sender channel influences the future oscillatory activity in a specific receiver channel relative to all possible receivers in the network. The proposed modeling approach provided key insights into potential functional relationships among simultaneously recorded sites during performance of a complex memory task. Specifically, this novel method was successful in quantifying patterns of effective connectivity across electrode locations, and in capturing how these patterns varied across trial epochs and trial types.

Multi-Channel Capacitive Sensor Arrays

Directory of Open Access Journals (Sweden)

Bingnan Wang

2016-01-01

Full Text Available In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved.

Multichannel linear descriptors analysis for event-related EEG of vascular dementia patients during visual detection task.

Science.gov (United States)

Lou, Wutao; Xu, Jin; Sheng, Hengsong; Zhao, Songzhen

2011-11-01

Multichannel EEG recorded in a task condition could contain more information about cognition. However, that has not been widely investigated in the vascular-dementia (VaD)- related studies. The purpose of this study was to explore the differences of brain functional states between VaD patients and normal controls while performing a detection task. Three multichannel linear descriptors, i.e. spatial complexity (Ω), field strength (Σ) and frequency of field changes (Φ), were applied to analyse four frequency bands (delta, theta, alpha and beta) of multichannel event-related EEG signals for 12 VaD patients (mean age ± SD: 69.25 ± 10.56 years ; MMSE score ± SD: 22.58 ± 4.42) and 12 age-matched healthy subjects (mean age ± SD: 67.17 ± 5.97 years ; MMSE score ± SD: 29.08 ± 0.9). The correlations between the three measures and MMSE scores were also analysed. VaD patients showed a significant higher Ω value in the delta (p = 0.013) and theta (p = 0.021) frequency bands, a lower Σ value (p = 0.011) and a higher Φ (p = 0.008) value in the delta frequency band compared with normal controls. The MMSE scores were negatively correlated with the Ω (r = -0.52, p = 0.01) and Φ (r = -0.47, p = 0.02) values in the delta frequency band. The results indicated the VaD patients presented a reduction of synchronization in the slow frequency band during target detection, and suggested more neurons might be activated in VaD patients compared with normal controls. The Ω and Φ measures in the delta frequency band might be used to evaluate the degree of cognitive dysfunction. The multichannel linear descriptors are promising measures to reveal the differences in brain functions between VaD patients and normal subjects, and could potentially be used to evaluate the degree of cognitive dysfunction in VaD patients. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Multichannel simultaneous magnetic induction measurement system (MUSIMITOS)

International Nuclear Information System (INIS)

Steffen, Matthias; Leonhardt, Steffen; Heimann, Konrad; Bernstein, Nina

2008-01-01

Non-contact heart and lung activity monitoring would be a desirable supplement to conventional monitoring techniques. Based on the potential of non-contact magnetic induction measurements, requirements for an adequate monitoring system were estimated. This formed the basis for the development of the presented extendable multichannel simultaneous magnetic induction measurement system (MUSIMITOS). Special focus was given to the dynamic behaviour and simultaneous multichannel measurements, so that the system allows for up to 14 receiver coils working simultaneously at 6 excitation frequencies. Moreover, a real-time software concept for online signal processing visualization in combination with a fast software demodulation is presented. Finally, first steps towards a clinical application are pointed out and technical performance as well as first in vivo measurements are presented. This paper covers some aspects previously presented in Steffen and Leonhardt (2007 Proc. 13th Int. Conf. on Electrical Bioimpedance and the 8th Conf. on Electrical Impedance Tomography, Graz 2007)

Multichannel waveform display system

International Nuclear Information System (INIS)

Kolvankar, V.G.

1989-01-01

For any multichannel data acquisition system, a multichannel paper chart recorder undoubtedly forms an essential part of the system. When deployed on-line, it instantaneously provides, for visual inspection, hard copies of the signal waveforms on common time base at any desired sensitivity and time resolution. Within the country, only a small range of these strip chart recorder s is available, and under stringent specifications imported recorders are often procured. The cost of such recorders may range from 1 to 5 lakhs of rupees in foreign exchange. A system to provide on the oscilloscope a steady display of multichannel waveforms, refreshed from the digital data stored in the memory is developed. The merits and demerits of the display system are compared with that built around a conventional paper chart recorder. Various illustrations of multichannel seismic event data acquired at Gauribidanur seismic array station are also presented. (author). 2 figs

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...

The multichannel system of synchronous photon counting of range 50 ns - 100 ms

Energy Technology Data Exchange (ETDEWEB)

Dmitriev, S M [and others

1996-12-31

A new type of the multichannel system of synchronous photon counting is designed. The recording past of the analyzer is described and the whole measurement process is considered. Frequency of the master generator is 75 MHz. 1 ref.; 2 figs.

Galvanically Decoupled Current Source Modules for Multi-Channel Bioimpedance Measurement Systems

Directory of Open Access Journals (Sweden)

Roman Kusche

2017-10-01

Full Text Available Bioimpedance measurements have become a useful technique in the past several years in biomedical engineering. Especially, multi-channel measurements facilitate new imaging and patient monitoring techniques. While most instrumentation research has focused on signal acquisition and signal processing, this work proposes the design of an excitation current source module that can be easily implemented in existing or upcoming bioimpedance measurement systems. It is galvanically isolated to enable simultaneous multi-channel bioimpedance measurements with a very low channel-coupling. The system is based on a microcontroller in combination with a voltage-controlled current source circuit. It generates selectable sinusoidal excitation signals between 0.12 and 1.5 mA in a frequency range from 12 to 250 kHz, whereas the voltage compliance range is ±3.2 V. The coupling factor between two current sources, experimentally galvanically connected with each other, is measured to be less than −48 dB over the entire intended frequency range. Finally, suggestions for developments in the future are made.

The impact of the multi-channel retail mix on online store choice: Does online experience matter?

OpenAIRE

Melis, Kristina; Campo, Katia; Breugelmans, Els; Lamey, Lien

2015-01-01

More and more grocery retailers are becoming multi-channel retailers, as they are opening an online alternative next to their traditional offline supermarkets. While the number of multi-channel grocery shoppers is also expanding at a fast growth rate, there are still large differences in online shopping frequency, and as a result, in the levels of experience with buying in the online grocery channel. This study wants to (i) identify the underlying drivers of online store choice and (ii) explo...

Virtual Microphones for Multichannel Audio Resynthesis

Directory of Open Access Journals (Sweden)

Athanasios Mouchtaris

2003-09-01

Full Text Available Multichannel audio offers significant advantages for music reproduction, including the ability to provide better localization and envelopment, as well as reduced imaging distortion. On the other hand, multichannel audio is a demanding media type in terms of transmission requirements. Often, bandwidth limitations prohibit transmission of multiple audio channels. In such cases, an alternative is to transmit only one or two reference channels and recreate the rest of the channels at the receiving end. Here, we propose a system capable of synthesizing the required signals from a smaller set of signals recorded in a particular venue. These synthesized “virtual” microphone signals can be used to produce multichannel recordings that accurately capture the acoustics of that venue. Applications of the proposed system include transmission of multichannel audio over the current Internet infrastructure and, as an extension of the methods proposed here, remastering existing monophonic and stereophonic recordings for multichannel rendering.

Essays on multichannel customer management

NARCIS (Netherlands)

Konus, U.

2010-01-01

The main goal of this dissertation is to gain a greater understanding of multichannel customer behavior and how firms can manage their multichannel marketing activities. The first study reveals that three customer segments can be identified based on their orientation towards using multiple channels

Multi-channel polarized thermal emitter

Science.gov (United States)

Lee, Jae-Hwang; Ho, Kai-Ming; Constant, Kristen P

2013-07-16

A multi-channel polarized thermal emitter (PTE) is presented. The multi-channel PTE can emit polarized thermal radiation without using a polarizer at normal emergence. The multi-channel PTE consists of two layers of metallic gratings on a monolithic and homogeneous metallic plate. It can be fabricated by a low-cost soft lithography technique called two-polymer microtransfer molding. The spectral positions of the mid-infrared (MIR) radiation peaks can be tuned by changing the periodicity of the gratings and the spectral separation between peaks are tuned by changing the mutual angle between the orientations of the two gratings.

Modeling High-Dimensional Multichannel Brain Signals

KAUST Repository

Hu, Lechuan; Fortin, Norbert J.; Ombao, Hernando

2017-01-01

aspects: first, there are major statistical and computational challenges for modeling and analyzing high-dimensional multichannel brain signals; second, there is no set of universally agreed measures for characterizing connectivity. To model multichannel

Multichannel analog temperature sensing system

International Nuclear Information System (INIS)

Gribble, R.

1985-08-01

A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

12.5 Gb/s multi-channel broadcasting transmission for free-space optical communication based on the optical frequency comb module.

Science.gov (United States)

Tan, Jun; Zhao, Zeping; Wang, Yuehui; Zhang, Zhike; Liu, Jianguo; Zhu, Ninghua

2018-01-22

A wide-spectrum, ultra-stable optical frequency comb (OFC) module with 100 GHz frequency intervals based on a quantum dot mode locked (QDML) laser is fabricated by our lab, and a scheme with 12.5 Gb/s multi-channel broadcasting transmission for free-space optical (FSO) communication is proposed based on the OFC module. The output power of the OFC is very stable, with the specially designed circuit and the flatness of the frequency comb over the span of 6 nm, which can be limited to 1.5 dB. Four channel wavelengths are chosen to demonstrate one-to-many channels for FSO communication, like optical wireless broadcast. The outdoor experiment is established to test the bit error rate (BER) and eye diagrams with 12.5 Gb/s on-off keying (OOK). The indoor experiment is used to test the highest traffic rate, which is up to 21 Gb/s for one-hop FSO communication. To the best of our knowledge, this scheme is the first to propose the realization of one-to-many broadcasting transmission for FSO communication based on the OFC module. The advantages of integration, miniaturization, channelization, low power consumption, and unlimited bandwidth of one-to-many broadcasting communication scheme, shows promising results on constructing the future space-air-ground-ocean (SAGO) FSO communication networks.

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.

Multichannel analyzer embedded in FPGA

International Nuclear Information System (INIS)

Garcia D, A.; Hernandez D, V. M.; Vega C, H. R.; Ordaz G, O. O.; Bravo M, I.

2017-10-01

Ionizing radiation has different applications, so it is a very significant and useful tool, which in turn can be dangerous for living beings if they are exposed to uncontrolled doses. However, due to its characteristics, it cannot be perceived by any of the senses of the human being, so that in order to know the presence of it, radiation detectors and additional devices are required to quantify and classify it. A multichannel analyzer is responsible for separating the different pulse heights that are generated in the detectors, in a certain number of channels; according to the number of bits of the analog to digital converter. The objective of the work was to design and implement a multichannel analyzer and its associated virtual instrument, for nuclear spectrometry. The components of the multichannel analyzer were created in VHDL hardware description language and packaged in the Xilinx Vivado design suite, making use of resources such as the ARM processing core that the System on Chip Zynq contains and the virtual instrument was developed on the LabView programming graphics platform. The first phase was to design the hardware architecture to be embedded in the FPGA and for the internal control of the multichannel analyzer the application was generated for the ARM processor in C language. For the second phase, the virtual instrument was developed for the management, control and visualization of the results. The data obtained as a result of the development of the system were observed graphically in a histogram showing the spectrum measured. The design of the multichannel analyzer embedded in FPGA was tested with two different radiation detection systems (hyper-pure germanium and scintillation) which allowed determining that the spectra obtained are similar in comparison with the commercial multichannel analyzers. (Author)

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

Tunable multichannel filter in photonic crystal heterostructure containing permeability-negative materials

International Nuclear Information System (INIS)

Hu Xiaoyong; Liu Zheng; Gong Qihuang

2008-01-01

A tunable multichannel filter is demonstrated theoretically based on a one-dimensional photonic crystal heterostructure containing permeability-negative material. The filtering properties of the photonic crystal filter, including the channel number and frequency, can be tuned by adjusting the structure parameters or by a pump laser. The angular response of the photonic crystal filter and the influences of the losses on the filtering properties are also analyzed

Tunable multichannel filter in photonic crystal heterostructure containing permeability-negative materials

Energy Technology Data Exchange (ETDEWEB)

Hu Xiaoyong [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China)], E-mail: xiaoyonghu@pku.edu.cn; Liu Zheng [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Gong Qihuang [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China)], E-mail: qhgong@pku.edu.cn

2008-01-14

A tunable multichannel filter is demonstrated theoretically based on a one-dimensional photonic crystal heterostructure containing permeability-negative material. The filtering properties of the photonic crystal filter, including the channel number and frequency, can be tuned by adjusting the structure parameters or by a pump laser. The angular response of the photonic crystal filter and the influences of the losses on the filtering properties are also analyzed.

Multichannel analyzer type CMA-3

International Nuclear Information System (INIS)

Czermak, A.; Jablonski, J.; Ostrowicz, A.

1978-01-01

Multichannel analyzer CMA-3 is designed for two-parametric analysis with operator controlled logical windows. It is implemented in CAMAC standard. A single crate contains all required modules and is controlled by the PDP-11/10 minicomputer. Configuration of CMA-3 is shown. CMA-3 is the next version of the multichannel analyzer described in report No 958/E-8. (author)

Multi-channel mechanical test machine for HANARO (I)

International Nuclear Information System (INIS)

Song, M. S.; Choi, Y.; Cho, M. S.; Kim, B. G.; Kang, Y. H.

2004-01-01

Design and fabrication of multi-channel mechanical test machine is useful and important for the study of in-pile test of nuclear materials in HANARO. The dimension and shape of the multi-channel mechanical test machine should be fixed to a test reactor and their objectives. KAERI successfully developed a non-instrumented multi-channel mechanical test machine for material irradiation tests in a domestic research reactor, HANARO. This results in strongly stimulating and accelerating irradiation tests of materials in domestic industry and research fields with HANARO. Although various types of in-pile creep capsule were made for well installation in each test reactor, there is no in-pile creep multi-channel mechanical test machine for HANARO. Hence, the objectives of this study are to fabricate and test a multi-channel mechanical test machine of HANARO

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.

Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

Science.gov (United States)

Abdelaziz, Ayman A.; Ishijima, Tatsuo; Seto, Takafumi; Osawa, Naoki; Wedaa, Hassan; Otani, Yoshio

2016-06-01

The aim of this study is to investigate the effect of the intermediate frequency (1-10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect.

Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

International Nuclear Information System (INIS)

Abdelaziz, Ayman A; Ishijima, Tatsuo; Seto, Takafumi; Otani, Yoshio; Osawa, Naoki; Wedaa, Hassan

2016-01-01

The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO 2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect. (paper)

Radio frequency ablation of small renal tumors:: intermediate results.

Science.gov (United States)

Hwang, J J; Walther, M M; Pautler, S E; Coleman, J A; Hvizda, J; Peterson, James; Linehan, W M; Wood, B J

2004-05-01

With evolving radio frequency technology, the clinical application of radio frequency ablation (RFA) has been actively investigated in the treatment for small renal tumors. We present our intermediate patient outcomes after RFA. Since January 2001, 17 patients with a total of 24 hereditary renal tumors ranging from 1.2 to 2.85 cm were treated with RFA using the 200 W Cool-tip RF System (Radionics, Burlington, Massachusetts) under laparoscopic (9) or percutaneous (8) guidance and had a minimum 1-year followup. A percutaneous approach was considered unsuitable if kidney tumors were contiguous to bowel, ureter or large vessels. Treatment eligibility criteria included an average tumor diameter of less than 3.0 cm, tumor growth during 1 year and solid appearance with contrast enhancement (HU change greater than 20) on computerized tomography (CT). Postoperative followup consisted of CT with and without intravenous contrast, and renal function assessment at regular intervals. Median patient age was 38 years (range 20 to 51). At a median followup of 385 days (range 342 to 691), median tumor or thermal lesion diameter decreased from 2.26 to 1.62 cm (p = 0.0013), and only 1 lesion (4%), which was located centrally near the hilum, exhibited contrast enhancement (HU change greater than 10) on CT at 12 months. Of the 15 renal tumors ablated laparoscopically, 13 were in direct contact with the bowel and 2 were abutting the ureter, necessitating mobilization before RFA. Laparoscopic ultrasound was used to guide radio frequency electrode placement and monitor the ablation process in these cases. Operative time and intraoperative blood loss (mean +/- standard mean of error) were 243 +/- 29 minutes and 67 +/- 9 cc, respectively. In 1 patient whose ureter was adherent to the tumor a ureteropelvic junction obstruction developed after laparoscopic RFA, requiring open repair. At the minimum 1-year followup 23 of 24 ablated tumors lacked contrast uptake on CT, meeting our radiographic

Multichannel modeling and two-photon coherent transfer paths in NaK

Science.gov (United States)

Schulze, T. A.; Temelkov, I. I.; Gempel, M. W.; Hartmann, T.; Knöckel, H.; Ospelkaus, S.; Tiemann, E.

2013-08-01

We explore possible pathways for the creation of ultracold polar NaK molecules in their absolute electronic and rovibrational ground state starting from ultracold Feshbach molecules. In particular, we present a multichannel analysis of the electronic ground and K(4p)+Na(3s) excited-state manifold of NaK, analyze the spin character of both the Feshbach molecular state and the electronically excited intermediate states and discuss possible coherent two-photon transfer paths from Feshbach molecules to rovibronic ground-state molecules. The theoretical study is complemented by the demonstration of stimulated Raman adiabatic passage from the X1Σ+(v=0) state to the a3Σ+ manifold on a molecular beam experiment.

Ratio-scaling of listener preference of multichannel reproduced sound

DEFF Research Database (Denmark)

Choisel, Sylvain; Wickelmaier, Florian

2005-01-01

-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...

Multichannel spectral mode of the ALOHA up-conversion interferometer

Science.gov (United States)

Lehmann, L.; Darré, P.; Boulogne, H.; Delage, L.; Grossard, L.; Reynaud, F.

2018-06-01

In this paper, we propose a multichannel spectral configuration of the Astronomical Light Optical Hybrid Analysis (ALOHA) instrument dedicated to high-resolution imaging. A frequency conversion process is implemented in each arm of an interferometer to transfer the astronomical light to a shorter wavelength domain. Exploiting the spectral selectivity of this non-linear optical process, we propose to use a set of independent pump lasers in order to simultaneously study multiple spectral channels. This principle is experimentally demonstrated with a dual-channel configuration as a proof-of-principle.

The Bateman method for multichannel scattering theory

International Nuclear Information System (INIS)

Kim, Y. E.; Kim, Y. J.; Zubarev, A. L.

1997-01-01

Accuracy and convergence of the Bateman method are investigated for calculating the transition amplitude in multichannel scattering theory. This approximation method is applied to the calculation of elastic amplitude. The calculated results are remarkably accurate compared with those of exactly solvable multichannel model

Observations of low and intermediate-frequency-peaked BL Lacs above 100 GeV with VERITAS

Directory of Open Access Journals (Sweden)

Errando M.

2013-12-01

Full Text Available Most of the ~ 50 blazars detected to date at TeV energies (E > 0.1 TeV are high-frequency-peaked BL Lacs (HBLs. Only a handful episodic detections of low- and intermediate-frequency-peaked BL Lacs (LBL/IBLs, with synchrotron peak frequencies in the infrared and optical regime have been reported by ground-based gamma-ray telescopes, typically during high-flux states. The VERITAS array located in southern Arizona has observed five known TeV LBL/IBLs since 2009: 3C 66A, WComae, PKS 1424+240, S5 0716+714 and BL Lacertae, with exposures of 5-10 hours/year, which so far resulted in the detection of a bright, sub-hour timescale gamma-ray flare of BL Lacertae in June 2011. We also report the detection and characterization of two new IBLs: VER J0521+211 and B2 1215+30.

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.

Multi-channel ground-penetrating radar to explore spatial variations in thaw depth and moisture content in the active layer of a permafrost site

Directory of Open Access Journals (Sweden)

U. Wollschläger

2010-08-01

Full Text Available Multi-channel ground-penetrating radar (GPR was applied at a permafrost site on the Tibetan Plateau to investigate the influence of surface properties and soil texture on the late-summer thaw depth and average soil moisture content of the active layer. Measurements were conducted on an approximately 85 × 60 m² sized area with surface and soil textural properties that ranged from medium to coarse textured bare soil to finer textured, sparsely vegetated areas covered with fine, wind blown sand, and it included the bed of a gravel road. The survey allowed a clear differentiation of the various units. It showed (i a shallow thaw depth and low average soil moisture content below the sand-covered, vegetated area, (ii an intermediate thaw depth and high average soil moisture content along the gravel road, and (iii an intermediate to deep thaw depth and low to intermediate average soil moisture content in the bare soil terrain. From our measurements, we found hypotheses for the permafrost processes at this site leading to the observed late-summer thaw depth and soil moisture conditions. The study clearly indicates the complicated interactions between surface and subsurface state variables and processes in this environment. Multi-channel GPR is an operational technology to efficiently study such a system at scales varying from a few meters to a few kilometers.

A wireless, compact, and scalable bioimpedance measurement system for energy-efficient multichannel body sensor solutions

International Nuclear Information System (INIS)

Ramos, J; Ausín, J L; Lorido, A M; Redondo, F; Duque-Carrillo, J F

2013-01-01

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 cm 2 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.

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.

Study on intermediate frequency power supply automatic monitor system

International Nuclear Information System (INIS)

Wang Yuntong; Xu Bin

2007-06-01

A new design project of the automatic monitor system for the intermediate frequency power supply system by using the communication server is put for- ward and the realizing principle method and the key technique are clarified in detail. This system made use of the conversion function with the series communication server's control, realized the data collecting function by the double machine backup and redundancy. The new network system adopted the photoelectric-insulated-communication connect device and the diagnosis technique, increased the anti-interference ability, the communication adopted the technique by the alarm information sending out in first and circularly repeating, the slowly speed is overcame in the original monitor network system, and strengthened the celerity of the monitor system and the reliability of the alarm report. After the new monitor system running, the result shows that the functions is more perfect than the original monitor system, the usage is more convenient, have the higher and dependable stability, the report of alarm is more quickly, and is convenient for the analysis after the trouble, at the same time, the system still have the strong ability and value to expand. (authors)

Multi-channel data acquisition system for CT

International Nuclear Information System (INIS)

Cao Fuqiang; He Bin; Liu Guohua; Xu Minjian

2009-01-01

The architecture design and realization of a data acquisition system for multi-channel CT is described. The article introduces the conversion of analog signal to digital signal, the data cache and transmission. This data acquisition system can be widely used in the system which requires the multi-channel, weak current signal detection. (authors)

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.

Computer-based multi-channel analyzer based on internet

International Nuclear Information System (INIS)

Zhou Xinzhi; Ning Jiaoxian

2001-01-01

Combined the technology of Internet with computer-based multi-channel analyzer, a new kind of computer-based multi-channel analyzer system which is based on browser is presented. Its framework and principle as well as its implementation are discussed

Analysis and compensation of synchronous measurement error for multi-channel laser interferometer

International Nuclear Information System (INIS)

Du, Shengwu; Hu, Jinchun; Zhu, Yu; Hu, Chuxiong

2017-01-01

Dual-frequency laser interferometer has been widely used in precision motion system as a displacement sensor, to achieve nanoscale positioning or synchronization accuracy. In a multi-channel laser interferometer synchronous measurement system, signal delays are different in the different channels, which will cause asynchronous measurement, and then lead to measurement error, synchronous measurement error (SME). Based on signal delay analysis of the measurement system, this paper presents a multi-channel SME framework for synchronous measurement, and establishes the model between SME and motion velocity. Further, a real-time compensation method for SME is proposed. This method has been verified in a self-developed laser interferometer signal processing board (SPB). The experiment result showed that, using this compensation method, at a motion velocity 0.89 m s −1 , the max SME between two measuring channels in the SPB is 1.1 nm. This method is more easily implemented and applied to engineering than the method of directly testing smaller signal delay. (paper)

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.

Analysis and compensation of synchronous measurement error for multi-channel laser interferometer

Science.gov (United States)

Du, Shengwu; Hu, Jinchun; Zhu, Yu; Hu, Chuxiong

2017-05-01

Dual-frequency laser interferometer has been widely used in precision motion system as a displacement sensor, to achieve nanoscale positioning or synchronization accuracy. In a multi-channel laser interferometer synchronous measurement system, signal delays are different in the different channels, which will cause asynchronous measurement, and then lead to measurement error, synchronous measurement error (SME). Based on signal delay analysis of the measurement system, this paper presents a multi-channel SME framework for synchronous measurement, and establishes the model between SME and motion velocity. Further, a real-time compensation method for SME is proposed. This method has been verified in a self-developed laser interferometer signal processing board (SPB). The experiment result showed that, using this compensation method, at a motion velocity 0.89 m s-1, the max SME between two measuring channels in the SPB is 1.1 nm. This method is more easily implemented and applied to engineering than the method of directly testing smaller signal delay.

The portable micro-computerized multichannel spectrometer for geological application

International Nuclear Information System (INIS)

Fang Fang; Jia Wenyi; Zou Rongsheng; Ma Yingjie; Zhou Jianbin

1999-01-01

The portable micro-computerized multichannel spectrometer is based on the book computer and employs the A/D integrated circuit with 12 bits. It is a 2048 channel spectrometer which is consisted of hardware and software. The author analyzed the hardware circuit and software construction of the micro-computerized multichannel spectrometer which is suitable for filed geological application. The main technical specifications and application of the new multichannel spectrometer were also discussed

The portable micro-computerized multichannel spectrometer for geological application

International Nuclear Information System (INIS)

Fang Fang; Jia Wenyi; Zhou Rongsheng; Ma Yingjie; Zhou Jianbin

1999-01-01

The portable micro-computerized multichannel spectrometer is based on the book computer and employs the A/D integrated circuit with 12 bits. It is a 2048 channel spectrometer which consists of hardware and software. The author analyzed the hardware circuit and software construction of the micro-computerized multichannel spectrometer which is suitable for field geological application. The main technical specifications and application of the new multichannel spectrometer were also discussed

Information acquisition and financial intermediation

OpenAIRE

Boyarchenko, Nina

2012-01-01

This paper considers the problem of information acquisition in an intermediated market, where the specialists have access to superior technology for acquiring information. These informational advantages of specialists relative to households lead to disagreement between the two groups, changing the shape of the intermediation-constrained region of the economy and increasing the frequency of periods when the intermediation constraint binds. Acquiring the additional information is, however, cost...

Development and implementation of own software for dosimetry multichannel film

International Nuclear Information System (INIS)

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

2013-01-01

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)

Airborne MSS data processing for multichannel SWIR sensor

Energy Technology Data Exchange (ETDEWEB)

Urai, Minoru; Yamaguchi, Yasushi

1988-05-17

This paper describes the specification of an airborne multi-channel spectrum scanner (MSS) and data processing. MSS has 13 channels of frequencies in the visible - heat infrared region. The channels 1 - 3 correspond to a visible image, the channels 4, 5 to the absorption bands of iron oxides, the channels 6 - 9 (2.2 (m)m band) to the absorption bands of O-H group and carbonates, and the channels 10 - 13 to absorption bands in the heat infrared region. By the least squares residual (LSR) method, a mineral having an absorption band of 2.2 (m)m was further examined. As a result, the LSR image displayed an orange-colored portion. This portion was identified to correspond to epidote. Silica, which has an absorption band of 8 - 10 (m)m in the heat infrared region, was displayed in blue color. A high frequency resolution sensor has a great potential for discrimination and identification of minerals. (2 figs, 2 tabs, 2 refs)

Dynamic phasing of multichannel cw laser radiation by means of a stochastic gradient algorithm

Energy Technology Data Exchange (ETDEWEB)

Volkov, V A; Volkov, M V; Garanin, S G; Dolgopolov, Yu V; Kopalkin, A V; Kulikov, S M; Starikov, F A; Sukharev, S A; Tyutin, S V; Khokhlov, S V; Chaparin, D A [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

2013-09-30

The phasing of a multichannel laser beam by means of an iterative stochastic parallel gradient (SPG) algorithm has been numerically and experimentally investigated. The operation of the SPG algorithm is simulated, the acceptable range of amplitudes of probe phase shifts is found, and the algorithm parameters at which the desired Strehl number can be obtained with a minimum number of iterations are determined. An experimental bench with phase modulators based on lithium niobate, which are controlled by a multichannel electronic unit with a real-time microcontroller, has been designed. Phasing of 16 cw laser beams at a system response bandwidth of 3.7 kHz and phase thermal distortions in a frequency band of about 10 Hz is experimentally demonstrated. The experimental data are in complete agreement with the calculation results. (control of laser radiation parameters)

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

Multichannel, sequential or combined X-ray spectrometry

International Nuclear Information System (INIS)

Florestan, J.

1979-01-01

X-ray spectrometer qualities and defects are evaluated for sequential and multichannel categories. Multichannel X-ray spectrometer has time-coherency advantage and its results could be more reproducible; on the other hand some spatial incoherency limits low percentage and traces applications, specially when backgrounds are very variable. In this last case, sequential X-ray spectrometer would find again great usefulness [fr

Multi-channel unidirectional transmission of phononic crystal heterojunctions

Science.gov (United States)

Xu, Zhenlong; Tong, Jie; Wu, Fugen

2018-02-01

Two square steel columns are arranged in air to form two-dimensional square lattice phononic crystals (PNCs). Two PNCs can be combined into a non-orthogonal 45∘ heterojunction when the difference in the directional band gaps of the two PNC types is utilized. The finite element method is used to calculate the acoustic band structure, the heterogeneous junction transmission characteristics, acoustic field distribution, and many others. Results show that a non-orthogonal PNC heterojunction can produce a multi-channel unidirectional transmission of acoustic waves. With the square scatterer rotated, the heterojunction can select a frequency band for unidirectional transmission performance. This capability is particularly useful for constructing acoustic diodes with wide-bands and high-efficiency unidirectional transmission characteristics.

Calculated characteristics of multichannel photoelectron multipliers

International Nuclear Information System (INIS)

Vasil'chenko, V.G.; Dajkovskij, A.G.; Milova, N.V.; Rakhmatov, V.E.; Rykalin, V.I.

1990-01-01

Structural features and main calculated characteristics of some modifications of position-sensitive two-coordinate multichannel photoelectron multipliers (PEM) with plate-type multiplying systems are described. The presented PEM structures are free from direct optical and ion feedbacks, provide coordinate resolution ≅ 1 mm with efficiency of photoelectron detection ≅ 90%. Capabilities for using silicon field-effect photocathodes, providing electron extraction into vacuum, as well as prospects of using multichannel multiplying systems for readout of the data from solid detectors are considered

The Buywell Way: seven essential practices of a highly successful multi-channel e-tailer

Directory of Open Access Journals (Sweden)

Mary Tate

2005-05-01

Full Text Available After the dot-com bust there is considerable evidence that multi-channel retailers are more successful than purely on-line retailers. Multi-channel retailing is becoming mainstream and considerable research exists on successful multi-channel strategies. Despite this, some organisations are having more success than others with their multi-channel approach. We talked to the management of one of Australasia’s most successful multi-channel apparel and home-ware retailers about the theory and practice of multi-channel retailing, with the aim of building on existing theory in multi-channel e-commerce.

Highly Efficient Compression Algorithms for Multichannel EEG.

Science.gov (United States)

Shaw, Laxmi; Rahman, Daleef; Routray, Aurobinda

2018-05-01

The difficulty associated with processing and understanding the high dimensionality of electroencephalogram (EEG) data requires developing efficient and robust compression algorithms. In this paper, different lossless compression techniques of single and multichannel EEG data, including Huffman coding, arithmetic coding, Markov predictor, linear predictor, context-based error modeling, multivariate autoregression (MVAR), and a low complexity bivariate model have been examined and their performances have been compared. Furthermore, a high compression algorithm named general MVAR and a modified context-based error modeling for multichannel EEG have been proposed. The resulting compression algorithm produces a higher relative compression ratio of 70.64% on average compared with the existing methods, and in some cases, it goes up to 83.06%. The proposed methods are designed to compress a large amount of multichannel EEG data efficiently so that the data storage and transmission bandwidth can be effectively used. These methods have been validated using several experimental multichannel EEG recordings of different subjects and publicly available standard databases. The satisfactory parametric measures of these methods, namely percent-root-mean square distortion, peak signal-to-noise ratio, root-mean-square error, and cross correlation, show their superiority over the state-of-the-art compression methods.

Generation of optical frequencies out of the frequency comb of a femtosecond laser for DWDM telecommunication

International Nuclear Information System (INIS)

Kim, Y-J; Chun, B J; Kim, Y; Hyun, S; Kim, S-W

2010-01-01

We exploit the frequency comb of a fs laser as the frequency ruler to generate reference optical frequencies for multi-channel DWDM (dense wavelength-division-multiplexing) telecommunication. Our fiber-based scheme of single-mode extraction enables on-demand generation of optical frequencies within the telecommunication band with an absolute frequency uncertainty of 9.1×10 -13 . The linewidth of extracted optical modes is less than 1 Hz, and the instability is measured 2.3×10 -15 at 10 s averaging. This outstanding performance of optical frequency generation would lead to a drastic improvement of the spectral efficiency for the next-generation DWDM telecommunication

A strategy for determination of test intervals of k-out-of-n multi-channel systems

International Nuclear Information System (INIS)

Cho, S.; Jiang, J.

2007-01-01

State space models for determination of the optimal test frequencies for k-out-of-n multi channel systems are developed in this paper. The analytic solutions for the optimal surveillance test frequencies are derived using the Markov process technique. The solutions show that an optimal test frequency which maximizes the target probability can be determined by decomposing the system states to 3 states based on the system configuration and success criteria. Examples of quantification of the state probabilities and the optimal test frequencies of a three-channel system and a four-channel system with different success criteria are presented. The strategy for finding the optimal test frequency developed in this paper can generally be applicable to any k-out-of-n multi-channel standby systems that involve complex testing schemes. (author)

Automatic pickup of arrival time of channel wave based on multi-channel constraints

Science.gov (United States)

Wang, Bao-Li

2018-03-01

Accurately detecting the arrival time of a channel wave in a coal seam is very important for in-seam seismic data processing. The arrival time greatly affects the accuracy of the channel wave inversion and the computed tomography (CT) result. However, because the signal-to-noise ratio of in-seam seismic data is reduced by the long wavelength and strong frequency dispersion, accurately timing the arrival of channel waves is extremely difficult. For this purpose, we propose a method that automatically picks up the arrival time of channel waves based on multi-channel constraints. We first estimate the Jaccard similarity coefficient of two ray paths, then apply it as a weight coefficient for stacking the multichannel dispersion spectra. The reasonableness and effectiveness of the proposed method is verified in an actual data application. Most importantly, the method increases the degree of automation and the pickup precision of the channel-wave arrival time.

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...

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.

Essays on Online and Multi-Channel Marketing

OpenAIRE

Zhang, Lingling

2016-01-01

Firms increasingly adopt online and multi-channel marketing strategies to reach and persuade consumers. Therefore, designing an effective marketing mix is critical to their success. The aim of my dissertation is to understand the strategy behind firms’ channel choices and assess marketing effectiveness. It consists of three large-scale empirical studies examining several important aspects of online and multi-channel marketing. My first essay focuses on the business-to-business (B2B) inte...

Multichannel DC SQUID sensor array for biomagnetic applications

International Nuclear Information System (INIS)

Hoenig, H.E.; Daalmans, G.M.; Bar, L.; Bommel, F.; Paulus, A.; Uhl, D.; Weisse, H.J.; Schneider, S.; Seifert, H.; Reichenberger, H.; Abraham-Fuchs, K.

1991-01-01

This paper reports on a biomagnetic multichannel system for medical diagnosis of brain and heart KRENIKON has been developed. 37 axial 2st order gradiometers - manufactured as flexible superconducting printed circuits - are arranged in a circular flat array of 19 cm diameter. Additionally, 3 orthogonal magnetometers are provided. The DC SQUIDs are fabricated in all-Nb technology, ten on a chip. The sensor system is operated in a shielded room with two layers of soft magnetic material and one layer of Al. The every day noise level is 10 fT/Hz 1/2 at frequencies above 10 Hz. Within 2 years of operation in a normal urban surrounding, useful clinical applications have been demonstrated (e.g. for epilepsy and heart arrhythmias)

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.

A customizable multi-channel loudness compensation method based on WDRC for digital hearing aids

Science.gov (United States)

Hu, Jiebin; Wang, Mingjiang; Ma, Min

2017-08-01

Loudness compensation is the most significant signal processing algorithm in digital hearing aids at present. An algorithm of multi-channel loudness compensation for embedded system has been put forward in this paper. The number of channels is customizable in this algorithm. The algorithm can set different number and different width of channels for each patient based on frequency domain wide dynamic range compression. First, according to the requirement of patient to divide the frequency domain into multiple unequal frequency bands. And then calculate the gain of each channel according to the input-output curve of sound pressure level. Finally, the time-domain impulse response of gain is computed from Mel filter banks. It is used in conjunction with speech enhancement processing in hearing aids. Simulation results show that the algorithm can effectively enhance the loudness for different frequencies.

Multi-channel phase-equivalent transformation and supersymmetry

OpenAIRE

Shirokov, A. M.; Sidorenko, V. N.

2000-01-01

Phase-equivalent transformation of local interaction is generalized to the multi-channel case. Generally, the transformation does not change the number of the bound states in the system and their energies. However, with a special choice of the parameters, the transformation removes one of the bound states and is equivalent to the multi-channel supersymmetry transformation recently suggested by Sparenberg and Baye. Using the transformation, it is also possible to add a bound state to the discr...

Mapping customer journeys in multichannel decision-making

OpenAIRE

Wolny, Julia; Charoensuksai, Nipawan

2014-01-01

This study is focused on multi-channel shopping, which refers to the integration of various channels in the consumer decision-making process. The term was coined in the early 2000s to signify the integration of offline and online shopping channels. It has since evolved to encompass the proliferating number of channels and media used to formulate, evaluate and execute buying decisions. With the explosion of mobile technologies and social media, multi-channel shopping has indeed become a journe...

Effect of Intermediate-Frequency Repetitive Transcranial Magnetic Stimulation on Recovery following Traumatic Brain Injury in Rats

Directory of Open Access Journals (Sweden)

Leticia Verdugo-Diaz

2017-01-01

Full Text Available Traumatic brain injury (TBI represents a significant public health concern and has been associated with high rates of morbidity and mortality. Although several research groups have proposed the use of repetitive transcranial magnetic stimulation (rTMS to enhance neuroprotection and recovery in patients with TBI, few studies have obtained sufficient evidence regarding its effects in this population. Therefore, we aimed to analyze the effect of intermediate-frequency rTMS (2 Hz on behavioral and histological recovery following TBI in rats. Male Wistar rats were divided into six groups: three groups without TBI (no manipulation, movement restriction plus sham rTMS, and movement restriction plus rTMS and three groups subjected to TBI (TBI only, TBI plus movement restriction and sham rTMS, and TBI plus movement restriction and rTMS. The movement restriction groups were included so that rTMS could be applied without anesthesia. Our results indicate that the restriction of movement and sham rTMS per se promotes recovery, as measured using a neurobehavioral scale, although rTMS was associated with faster and superior recovery. We also observed that TBI caused alterations in the CA1 and CA3 subregions of the hippocampus, which are partly restored by movement restriction and rTMS. Our findings indicated that movement restriction prevents damage caused by TBI and that intermediate-frequency rTMS promotes behavioral and histologic recovery after TBI.

Multi-channel Kondo necklace

International Nuclear Information System (INIS)

Fazekas, P.; Kee Haeyoung.

1993-06-01

A multi-channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins τ J , j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig

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.

Digital low level rf control system with four different intermediate frequencies for the International Linear Collider

Science.gov (United States)

Wibowo, Sigit Basuki; Matsumoto, Toshihiro; Michizono, Shinichiro; Miura, Takako; Qiu, Feng; Liu, Na

2017-09-01

A field programmable gate array-based digital low level rf (LLRF) control system will be used in the International Linear Collider (ILC) in order to satisfy the rf stability requirements. The digital LLRF control system with four different intermediate frequencies has been developed to decrease the required number of analog-to-digital converters in this system. The proof of concept of this technique was demonstrated at the Superconducting RF Test Facility in the High Energy Accelerator Research Organization, Japan. The amplitude and phase stability has fulfilled the ILC requirements.

Fast multichannel analyser

Energy Technology Data Exchange (ETDEWEB)

Berry, A; Przybylski, M M; Sumner, I [Science Research Council, Daresbury (UK). Daresbury Lab.

1982-10-01

A fast multichannel analyser (MCA) capable of sampling at a rate of 10/sup 7/ s/sup -1/ has been developed. The instrument is based on an 8 bit parallel encoding analogue to digital converter (ADC) reading into a fast histogramming random access memory (RAM) system, giving 256 channels of 64 k count capacity. The prototype unit is in CAMAC format.

Multichannel electrogastrography under a magnifying glass--an in-depth study on reproducibility of fed state electrogastrograms.

Science.gov (United States)

Krusiec-Swidergoł, B; Jonderko, K

2008-06-01

We checked on reproducibility of parameters of a multichannel electrogastrogram in adults after intake of typical, applied in electrogastrography, test meals. Recordings of multichannel electrogastrograms were accomplished in four blocks comprising 18 subjects (nine healthy volunteers and nine patients with functional GI disorders) each. Every subject had two examinations taken 1-2 days apart, and a third one was accomplished at least 2 weeks before or after the two other sessions. The registration involved a 30-min fasted and a 2-h postprandial period after one of the meal stimuli tested within a given block: 400 mL water, 400 g yoghurt (378 kcal), a scrambled eggs sandwich (370 kcal), a pancake (355 kcal). From among the parameters reflecting the propagation of the gastric slow waves, the average percentage of slow wave coupling (APSWC) exhibited a good (coefficient of variation for paired examinations CV(p) < or = 10%) to moderate (10 < CV(p) < or = 30%) reproducibility. On the other hand, the reproducibility of the maximum dominant frequency difference and the spatial dominant power difference was found to be unsatisfactory. The reproducibility of the multichannel electrogastrographic parameters did not differ between healthy volunteers and patients with functional GI disorders. Gender or the kind of a test meal did not affect the reproducibility of the electrogastrographic parameters either. The medium-term reproducibility was not any worse than the short-term one. From among the parameters of a multichannel electrogastrogram intended to quantify the propagation of slow waves, only the APSWC offers a reproducibility potentially good enough for clinical applications.

A multi-channel microcomputer data acquisition system

International Nuclear Information System (INIS)

Loureiro, J.S.

1987-01-01

A data acquisition system was developed in order to transfer automatically to a 64 kb microcomputer the data generated by a nuclear spectroscopy system in a multichannel analyser. The data in the memory are stored in a floppy disk and will be further used as data entry for any spectrum analysis program, eliminating the tedious work of manually digitizing the spectrum and the possible mistakes associated with it. The developed system connected a POLYMAX 201 DP microcomputer, under CP/M operational system, to a NUCLEAR DATA MODEL ND-65 multichannel analyser and was planned for either local spectrum analysis in the microcomputer using a simplified program, or remote analysis in a mainframe using the sophisticated analysis program SAMPO. With the present system, the time spent between printing out of the 4096 channels with the multichannel analyser printer and its corresponding introduction in the analysis program has been reduced from about 6 hours to less than 2 minutes. (author)

Multi-channel Kondo necklace

Energy Technology Data Exchange (ETDEWEB)

Fazekas, P; Haeyoung, Kee

1993-06-01

A multi-channel generalization of Doniach`s Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins {tau}{sub J}, j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig.

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...... the authors present a detailed longitudinal case study of how public authorities collaborated to create a multichannel strategy for a mandatory online self-service application for single parents. After the strategy was carried out there was an increase in the use of the application and a substantial reduction...... in calls. The authors offer contributions to the channel choice literature and recommendations on multichannel management to practitioners....

Determination of optimum "multi-channel surface wave method" field parameters.

Science.gov (United States)

2012-12-01

Multi-channel surface wave methods (especially the multi-channel analyses of surface wave method; MASW) are routinely used to : determine the shear-wave velocity of the subsurface to depths of 100 feet for site classification purposes. Users are awar...

Multichannel strategy - the dominant approach in modern retailing

OpenAIRE

Stojković Dragan; Lovreta Stipe; Bogetić Zoran

2016-01-01

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...

Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization

DEFF Research Database (Denmark)

Cardoso, J. F.; Delabrouille, J.; Ganga, K.

2015-01-01

)% from 353 to 70 GHz. We discuss this result within the context of existing dust models. The decrease in p could indicate differences in polarization efficiency among components of interstellar dust (e.g., carbon versus silicate grains). Our observational results provide inputs to quantify and optimize......Planck has mapped the intensity and polarization of the sky at microwave frequencies with unprecedented sensitivity. We use these data to characterize the frequency dependence of dust emission. We make use of the Planck 353 GHz I, Q, and U Stokes maps as dust templates, and cross-correlate them...... of the cosmic microwave background. We use a mask that focuses our analysis on the diffuse interstellar medium at intermediate Galactic latitudes. We determine the spectral indices of dust emission in intensity and polarization between 100 and 353 GHz, for each sky patch. Both indices are found to be remarkably...

Multichannel quantum defect and reduced R-matrix

International Nuclear Information System (INIS)

Hategan, C.; Ionescu, R.A.; Cutoiu, D.; Gugiu, M.

2002-01-01

The collision of an electron with the atomic electronic core or the scattering of a nucleon on the atomic nucleus, usually, result into multiparticle excitations producing a resonance of a compound system, followed by its decay in reaction channels. Both in the electron-atom collisions and in nucleon-nucleus reactions, these multichannel resonances are described by poles of all R-Matrix elements. The resonances originating in single particle states, either in electron-atom collision or in nucleon-nucleus scattering, are approached in quite different descriptions. For example, the single-particle resonance in nuclear scattering is described, in R-Matrix Theory, by a perturbative method due to Bloch. The original single-nucleon state overlaps the actual states of the nucleus, resulting into a micro-giant description of the single particle resonance. The spectroscopic aspects of the single particle state, mixed with actual nuclear states, are subject of nucleon (or single particle) Strength Function. The electron, involving single particle Rydberg state in an atomic collision, 'avoids' its wave function mixing with that of inner multielectron core, because it is spatially far-away located from that core. This process is usually described by the Multichannel Quantum Defect Theory (MQDT). In the electron-atom scattering rather the effect of inner multielectron core on Rydberg electrons is studied by means of a global parameter, historically called 'Quantum Defect'. Both these types of resonances have in common the preserving of the single-particle wave function in a complex system with multiparticle excitations. In this work one approaches description of single-particle (electron or nucleon) resonance in a multichannel system. The single particle multichannel resonances are not longer described by a R-Matrix pole (specific for resonances originating in multiparticle excitations) but rather by a natural method for incorporating a single particle state in R-Matrix Theory

Subject-specific optimization of channel currents for multichannel transcranial magnetic stimulation.

Science.gov (United States)

Cline, Christopher C; Johnson, Nessa N; He, Bin

2015-01-01

The goal of this work is to develop a focal transcranial magnetic stimulation (TMS) system using a multichannel coil array for high-resolution neuromodulation. We proposed a novel spatially-distributed stimulation strategy to significantly improve the focality of TMS. Computer simulations were conducted to evaluate the proposed approach and test the merits of multichannel TMS. Three different multichannel coil arrays were modeled in addition to a conventional figure-8 coil for comparison. Simulations were performed on finite element head models of six subjects constructed from anatomical MR images via an automated pipeline. Multichannel TMS arrays exhibited significantly more focal induced electric field magnitudes compared to the figure-8 coil. Additionally, electrical steering of stimulation sites without physical movement of the coil array was demonstrated.

Evaluation of multichannel Wiener filters applied to fine resolution passive microwave images of first-year sea ice

Science.gov (United States)

Full, William E.; Eppler, Duane T.

1993-01-01

The effectivity of multichannel Wiener filters to improve images obtained with passive microwave systems was investigated by applying Wiener filters to passive microwave images of first-year sea ice. Four major parameters which define the filter were varied: the lag or pixel offset between the original and the desired scenes, filter length, the number of lines in the filter, and the weight applied to the empirical correlation functions. The effect of each variable on the image quality was assessed by visually comparing the results. It was found that the application of multichannel Wiener theory to passive microwave images of first-year sea ice resulted in visually sharper images with enhanced textural features and less high-frequency noise. However, Wiener filters induced a slight blocky grain to the image and could produce a type of ringing along scan lines traversing sharp intensity contrasts.

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

International Nuclear Information System (INIS)

Lobanov, Valery E.; Vysloukh, Victor A.; Kartashov, Yaroslav V.

2010-01-01

We consider the evolution of multichannel excitations in longitudinally modulated waveguide arrays where the 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 the 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.

Direct Measurement of the Mode O Turbulent Boundary Layer Wall Pressure and Wall Shear Stress Spectra Using Air-Backed and Oil-Filled Multichannel Wavenumber Filters

National Research Council Canada - National Science Library

Peloquin, Mark

1999-01-01

..., thin cylinder in an axial flow field. These measurements, processed as wavenumber-frequency spectra, were made with a multichannel array composed of an air-backed cylinder structure and a 32-channel aperture of PVDF film sensors having...

Blocky inversion of multichannel elastic impedance for elastic parameters

Science.gov (United States)

Mozayan, Davoud Karami; Gholami, Ali; Siahkoohi, Hamid Reza

2018-04-01

Petrophysical description of reservoirs requires proper knowledge of elastic parameters like P- and S-wave velocities (Vp and Vs) and density (ρ), which can be retrieved from pre-stack seismic data using the concept of elastic impedance (EI). We propose an inversion algorithm which recovers elastic parameters from pre-stack seismic data in two sequential steps. In the first step, using the multichannel blind seismic inversion method (exploited recently for recovering acoustic impedance from post-stack seismic data), high-resolution blocky EI models are obtained directly from partial angle-stacks. Using an efficient total-variation (TV) regularization, each angle-stack is inverted independently in a multichannel form without prior knowledge of the corresponding wavelet. The second step involves inversion of the resulting EI models for elastic parameters. Mathematically, under some assumptions, the EI's are linearly described by the elastic parameters in the logarithm domain. Thus a linear weighted least squares inversion is employed to perform this step. Accuracy of the concept of elastic impedance in predicting reflection coefficients at low and high angles of incidence is compared with that of exact Zoeppritz elastic impedance and the role of low frequency content in the problem is discussed. The performance of the proposed inversion method is tested using synthetic 2D data sets obtained from the Marmousi model and also 2D field data sets. The results confirm the efficiency and accuracy of the proposed method for inversion of pre-stack seismic data.

In situ exposure assessment of intermediate frequency fields of diverse devices

International Nuclear Information System (INIS)

Van Den Bossche, Matthias; Verloock, Leen; Aerts, Sam; Joseph, Wout; Martens, Luc

2015-01-01

In this study, in situ exposure assessment of both electric and magnetic fields of different intermediate frequency (IF) sources is investigated. The authors investigated smart boards and touch-screens, energy-saving bulbs, fluorescent lamps, a portable hearing unit and an electro-surgical unit (ESU). For most of these sources, the electric field is the dominating quantity. International Commission on Non-Ionizing Radiation Protection reference levels are exceeded for touch-screens (44 kHz: up to 155.7 V m -1 at 5 cm), energy-saving bulbs (38-52 kHz: up to 117.3 V m -1 ), fluorescent lamps (52 kHz: up to 471 V m -1 at 5 cm) and ESUs (up to 920 kHz: 792 V m -1 at 0.5 cm). Magnetic field strengths up to 1.8 and 10.5 A m -1 were measured close to the ESU and portable hearing unit (69 V m -1 ), respectively. Large differences of measured field values exist among the various operating modes of the IF equipment. Compliance distances for general public range from 15.3 cm (touch-screen) to 25 cm (fluorescent lamps). (authors)

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 ...... 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.]......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...... were obtained for every orchestral part of two symphonies at the Technical University of Denmark. Five-channel auralizations were then created for each instrument, located at its typical position on-stage in a concert hall, by convolving five impulse responses from sources that each represent...

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

Use of trapezoidal shaping algorithm in the digital multi-channel system

International Nuclear Information System (INIS)

Wang Jihong; Wang Lianghou; Fang Zongliang

2011-01-01

It discusses one kind of digital filter technology-trapezoidal algorithm based on actual need of studying the digital multi-channel. Firstly, demonstrating the feasibility of the arithmetic with theoretical analysis; secondly, predigesting the process of the arithmetic; thirdly, simulating with MATLAB; lastly, using the arithmetic to measure data. The result of testing indicates trapezoidal shaping algorithm accords with the need of digital multi-channel shaping extraordinary. The best filter can be obtained by means of setting parameter due to superiority of digital multi-channel. (authors)

[Multi-channel cochlear implants in patients with Mondini malformation].

Science.gov (United States)

Li, Yong-xin; Han, De-min; Zhao, Xiao-tian; Chen, Xue-qing; Kong, Ying; Zheng, Jun; Liu, Bo; Liu, Sha; Mo, Ling-yan; Zhang, Hua; Wang, Shuo

2004-02-01

To describe clinical experiences with multi-channel cochlear implantation in patients with Mondini malformation. Among 300 patients who received multi-channel cochlear implants from 1996 to 2002 in Beijing Tongren Hospital, 15 patients were diagnosed with Mondini malformation. A retrospective analysis was performed dealing with the surgical techniques, mapping and rehabilitations characteristics after surgery. 15 patients with normal cochlear structure are consider as control group. Gusher is found more common than the normal cochlear implantation, most of them are serious. The electrodes are inserted in the "cochleostomy" in full length of 13 Patients, 2 pairs of electrodes remains outside of "cochleostomy" in 2 patients. No serious complications occurred after implantation. All patients have auditory sensations. The impedance of the electrodes, the T level, C level and the hearing threshold are similar with the normal cochlear implantation group. The results have no significant difference in compare with normal cochlear group(P > 0.05). Multi-channel cochlear implantation could be performed safely in patients with Mondini malformation. The primary outcome for patients with Mondini malformation are similar to those with normal cochlear structure following the multi-channel cochlear implantation.

Microfluidic Multichannel Flow Cytometer, Phase I

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...

Selling to the multi-channel consumer : strategic and operational challenges for multi-channel retailers

NARCIS (Netherlands)

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

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

The use of Matlab for colour fuzzy representation of multichannel EEG short time spectra.

Science.gov (United States)

Bigan, C; Strungaru, R

1998-01-01

During the last years, a lot of EEG research efforts was directed to intelligent methods for automatic analysis of data from multichannel EEG recordings. However, all the applications reported were focused on specific single tasks like detection of one specific "event" in the EEG signal: spikes, sleep spindles, epileptic seizures, K complexes, alpha or other rhythms or even artefacts. The aim of this paper is to present a complex system being able to perform a representation of the dynamic changes in frequency components of each EEG channel. This representation uses colours as a powerful means to show the only one frequency range chosen from the shortest epoch of signal able to be processed with the conventional "Short Time Fast Fourier Transform" (S.T.F.F.T.) method.

Multi-channel electrical impedance tomography for regional tissue hydration monitoring

International Nuclear Information System (INIS)

Chen, Xiaohui; Kao, Tzu-Jen; Ashe, Jeffrey M; Boverman, Gregory; Sabatini, James E; Davenport, David M

2014-01-01

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

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

Multichannel analyzer embedded in FPGA; Analizador multicanal embebido en FPGA

Energy Technology Data Exchange (ETDEWEB)

Garcia D, A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico); Ordaz G, O. O. [Universidad de Cordoba, Departamento de Arquitectura de Computadores, Electronica y Tecnologia Electronica, Campus de Rabanales, Ctra. N-IVa Km 396, 14071 Cordoba (Spain); Bravo M, I., E-mail: angelogarciad@hotmail.com [Universidad de Alcala de Henares, Departamento de Electronica, Campus Universitario, Carretera Madrid-Barcelona Km 33.600, 28801 Alcala de Henares, Madrid (Spain)

2017-10-15

Ionizing radiation has different applications, so it is a very significant and useful tool, which in turn can be dangerous for living beings if they are exposed to uncontrolled doses. However, due to its characteristics, it cannot be perceived by any of the senses of the human being, so that in order to know the presence of it, radiation detectors and additional devices are required to quantify and classify it. A multichannel analyzer is responsible for separating the different pulse heights that are generated in the detectors, in a certain number of channels; according to the number of bits of the analog to digital converter. The objective of the work was to design and implement a multichannel analyzer and its associated virtual instrument, for nuclear spectrometry. The components of the multichannel analyzer were created in VHDL hardware description language and packaged in the Xilinx Vivado design suite, making use of resources such as the ARM processing core that the System on Chip Zynq contains and the virtual instrument was developed on the LabView programming graphics platform. The first phase was to design the hardware architecture to be embedded in the FPGA and for the internal control of the multichannel analyzer the application was generated for the ARM processor in C language. For the second phase, the virtual instrument was developed for the management, control and visualization of the results. The data obtained as a result of the development of the system were observed graphically in a histogram showing the spectrum measured. The design of the multichannel analyzer embedded in FPGA was tested with two different radiation detection systems (hyper-pure germanium and scintillation) which allowed determining that the spectra obtained are similar in comparison with the commercial multichannel analyzers. (Author)

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.

Empirical Study on Multi-Channel Service Quality and Customer Loyalty of Retailers

OpenAIRE

Qi Yong-zhi

2014-01-01

This paper studies the influence of offline RSSQ (retailing store service quality), online store ESQ (E-service quality) and O2O MCISQ (multi-channel integration service quality) on traditional retailers' customer loyalty as well as the relation of them three in multi-channel retailing. 380 customers with both offline and online shopping experience at the same retailer's store are investigated. Through the structural equation model, we find out that in multi-channel retailing, RSSQ and MCISQ ...

Numerical solution of the multichannel scattering problem

International Nuclear Information System (INIS)

Korobov, V.I.

1992-01-01

A numerical algorithm for solving the multichannel elastic and inelastic scattering problem is proposed. The starting point is the system of radial Schroedinger equations with linear boundary conditions imposed at some point R=R m placed somewhere in asymptotic region. It is discussed how the obtained linear equation can be splitted into a zero-order operator and its pertturbative part. It is shown that Lentini - Pereyra variable order finite-difference method appears to be very suitable for solving that kind of problems. The derived procedure is applied to dμ+t→tμ+d inelastic scattering in the framework of the adiabatic multichannel approach. 19 refs.; 1 fig.; 1 tab

A fast multichannel analyser

International Nuclear Information System (INIS)

Berry, A.; Przybylski, M.M.; Sumner, I.

1982-01-01

A fast multichannel analyser (MCA) capable of sampling at a rate of 10 7 s -1 has been developed. The instrument is based on an 8 bit parallel encoding analogue to digital converter (ADC) reading into a fast histogramming random access memory (RAM) system, giving 256 channels of 64 k count capacity. The prototype unit is in CAMAC format. (orig.)

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.

Acousto-Optic Applications for Multichannel Adaptive Optical Processor

Science.gov (United States)

1992-06-01

AO cell and the two- channel line-scan camera system described in Subsection 4.1. The AO material for this IntraAction AOD-70 device was flint glass (n...Single-Channel 1.68 (flint glass ) 60,.0 AO Cell Multichannel 2.26 (TeO 2) 20.0 AO Cell Beam splitter 1.515 ( glass ) 50.8 Multichannel correlation was...Tone Intermodulation Dynamic Ranges of Longitudinal TeO2 Bragg Cells for Several Acoustic Power Densities 4-92 f f2 f 3 1 t SOURCE: Reference 21 TR-92

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.

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

International Nuclear Information System (INIS)

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. (general)

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.

A multichannel analyzer computer system for simultaneously measuring 64 spectra

International Nuclear Information System (INIS)

Jin Yuheng; Wan Yuqing; Zhang Jiahong; Li Li; Chen Guozhu

2000-01-01

The author introduces a multichannel analyzer computer system for simultaneously measuring 64 spectra with 64 coded independent inputs. The system is developed for a double chopper neutron scattering time-of-flight spectrometer. The system structure, coding method, operating principle and performances are presented. The system can also be used for other nuclear physics experiments which need multichannel analyzer with independent coded inputs

Robust adaptive multichannel SAR processing based on covariance matrix reconstruction

Science.gov (United States)

Tan, Zhen-ya; He, Feng

2018-04-01

With the combination of digital beamforming (DBF) processing, multichannel synthetic aperture radar(SAR) systems in azimuth promise well in high-resolution and wide-swath imaging, whereas conventional processing methods don't take the nonuniformity of scattering coefficient into consideration. This paper brings up a robust adaptive Multichannel SAR processing method which utilizes the Capon spatial spectrum estimator to obtain the spatial spectrum distribution over all ambiguous directions first, and then the interference-plus-noise covariance Matrix is reconstructed based on definition to acquire the Multichannel SAR processing filter. The performance of processing under nonuniform scattering coefficient is promoted by this novel method and it is robust again array errors. The experiments with real measured data demonstrate the effectiveness and robustness of the proposed method.

Separable expansion for realistic multichannel scattering problems

International Nuclear Information System (INIS)

Canton, L.; Cattapan, G.; Pisent, G.

1987-01-01

A new approach to the multichannel scattering problem with realistic local or nonlocal interactions is developed. By employing the negative-energy solutions of uncoupled Sturmian eigenvalue problems referring to simple auxiliary potentials, the coupling interactions appearing to the original multichannel problem are approximated by finite-rank potentials. By resorting to integral-equation tecniques the coupled-channel equations are then reduced to linear algebraic equations which can be straightforwardly solved. Compact algebraic expressions for the relevant scattering matrix elements are thus obtained. The convergence of the method is tasted in the single-channel case with realistic optical potentials. Excellent agreement is obtained with a few terms in the separable expansion for both real and absorptive interactions

Fast multichannel scaler

International Nuclear Information System (INIS)

Okayasu, T.; Takeuchi, S.; Nagai, S.

1987-01-01

A fast multichannel scaler achieving the minimum dwell time of 50 ns is described. The dead time due to memory cycle is eliminated by 4-phase operation of parallel-4 groups of counter RAMs. The MCS has 4 k channels in total. Differential nonlinearity is less than 0.4%. If an input pulse arrives near the channel boundary, it is caught temporarily for both channels and then sorted to go into a proper channel. Thus, the dead time near the channel boundary is also eliminated

Multi-channel imaging cytometry with a single detector

Science.gov (United States)

Locknar, Sarah; Barton, John; Entwistle, Mark; Carver, Gary; Johnson, Robert

2018-02-01

Multi-channel microscopy and multi-channel flow cytometry generate high bit data streams. Multiple channels (both spectral and spatial) are important in diagnosing diseased tissue and identifying individual cells. Omega Optical has developed techniques for mapping multiple channels into the time domain for detection by a single high gain, high bandwidth detector. This approach is based on pulsed laser excitation and a serial array of optical fibers coated with spectral reflectors such that up to 15 wavelength bins are sequentially detected by a single-element detector within 2.5 μs. Our multichannel microscopy system uses firmware running on dedicated DSP and FPGA chips to synchronize the laser, scanning mirrors, and sampling clock. The signals are digitized by an NI board into 14 bits at 60MHz - allowing for 232 by 174 pixel fields in up to 15 channels with 10x over sampling. Our multi-channel imaging cytometry design adds channels for forward scattering and back scattering to the fluorescence spectral channels. All channels are detected within the 2.5 μs - which is compatible with fast cytometry. Going forward, we plan to digitize at 16 bits with an A-toD chip attached to a custom board. Processing these digital signals in custom firmware would allow an on-board graphics processing unit to display imaging flow cytometry data over configurable scanning line lengths. The scatter channels can be used to trigger data buffering when a cell is present in the beam. This approach enables a low cost mechanically robust imaging cytometer.

Multichannel scaler with fast channel advance

International Nuclear Information System (INIS)

Murphy, D.M.

1985-01-01

A multichannel scaler has been constructed which is capable of running as fast as 250 ns per channel. It is compact, low power and requires no special construction techniques. Readout is into a memory accessible by a microprocessor. (orig.)

Dynamic Channel Slot Allocation Scheme and Performance Analysis of Cyclic Quorum Multichannel MAC Protocol

Directory of Open Access Journals (Sweden)

Xing Hu

2017-01-01

Full Text Available In high diversity node situation, multichannel MAC protocol can improve the frequency efficiency, owing to fewer collisions compared with single-channel MAC protocol. And the performance of cyclic quorum-based multichannel (CQM MAC protocol is outstanding. Based on cyclic quorum system and channel slot allocation, it can avoid the bottleneck that others suffered from and can be easily realized with only one transceiver. To obtain the accurate performance of CQM MAC protocol, a Markov chain model, which combines the channel-hopping strategy of CQM protocol and IEEE 802.11 distributed coordination function (DCF, is proposed. The results of numerical analysis show that the optimal performance of CQM protocol can be obtained in saturation bound situation. And then we obtain the saturation bound of CQM system by bird swarm algorithm. In addition, to improve the performance of CQM protocol in unsaturation situation, a dynamic channel slot allocation of CQM (DCQM protocol is proposed, based on wavelet neural network. Finally, the performance of CQM protocol and DCQM protocol is simulated by Qualnet platform. And the simulation results show that the analytic and simulation results match very well; the DCQM performs better in unsaturation situation.

Multichannel shopper segments and their covariates

NARCIS (Netherlands)

Konus, U.; Verhoef, P.C.; Neslin, S.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

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

A wearable multichannel tactile display of voice fundamental frequency.

Science.gov (United States)

Yeung, E; Boothroyd, A; Redmond, C

1988-12-01

This paper describes a wearable sensory aid that provides the deaf with tactually encoded information about intonation. Fundamental frequency is represented as both place and rate of vibration in a linear array of solenoids. Pitch extraction is accomplished through low-pass filtering and peak detection. A microcomputer is used to measure pitch period, which in turn determines which of the solenoids is actuated. By comparing consecutive periods, the system discriminates against random, noise-related inputs. The device is switchable between 1-, 8-, and 16-channel operation. The electronics package is contained in a case that may be worn on a belt. The solenoid array is worn on the forearm. The system is powered by five, rechargeable lithium cells and runs for at least 6 hours between charges. Proposed developments include the incorporation of digital pitch extraction methods and the option to use the spatial output dimension to encode speech parameters other than fundamental frequency.

Multichannel blind iterative image restoration

Czech Academy of Sciences Publication Activity Database

Šroubek, Filip; Flusser, Jan

2003-01-01

Roč. 12, č. 9 (2003), s. 1094-1106 ISSN 1057-7149 R&D Projects: GA ČR GA102/00/1711 Institutional research plan: CEZ:AV0Z1075907 Keywords : conjugate gradient * half-quadratic regularization * multichannel blind deconvolution Subject RIV: BD - Theory of Information Impact factor: 2.642, year: 2003 http://library.utia.cas.cz/prace/20030104.pdf

Quasibound states at thresholds in multichannel impurity scattering

International Nuclear Information System (INIS)

Kim, Sang Wook; Park, Hwa-Kyun; Sim, H-S; Schomerus, Henning

2003-01-01

We investigate the threshold behaviour of transmission resonances and quasibound states in the multichannel scattering problems of a one-dimensional (1D) time-dependent impurity potential, and the related problem of a single impurity in a quasi-1D wire. It was claimed before in the literature that a quasibound state disappears when a transmission zero collides with the subband boundary. However, the transmission line shape, the Friedel sum rule, and the delay time show that the quasibound states still survive and affect the physical quantities. We discuss the relation between threshold behaviour of transmission resonances, and quasibound states and their boundary conditions in the general context of multichannel scatterings

Laser frequency stabilization using a commercial wavelength meter

Science.gov (United States)

Couturier, Luc; Nosske, Ingo; Hu, Fachao; Tan, Canzhu; Qiao, Chang; Jiang, Y. H.; Chen, Peng; Weidemüller, Matthias

2018-04-01

We present the characterization of a laser frequency stabilization scheme using a state-of-the-art wavelength meter based on solid Fizeau interferometers. For a frequency-doubled Ti-sapphire laser operated at 461 nm, an absolute Allan deviation below 10-9 with a standard deviation of 1 MHz over 10 h is achieved. Using this laser for cooling and trapping of strontium atoms, the wavemeter scheme provides excellent stability in single-channel operation. Multi-channel operation with a multimode fiber switch results in fluctuations of the atomic fluorescence correlated to residual frequency excursions of the laser. The wavemeter-based frequency stabilization scheme can be applied to a wide range of atoms and molecules for laser spectroscopy, cooling, and trapping.

Data Stream Processing Study in a Multichannel Telemetry Data Registering System

Directory of Open Access Journals (Sweden)

I. M. Sidyakin

2015-01-01

Full Text Available The paper presents the results of research that is aimed to improve the reliability of transmission of telemetry information (TMI through a communication channel with noise from the object of telemeasurements to the telemetry system for collecting and processing data. It considers the case where the quality of received information changes over time, due to movement of the object relative to the receiving station, or other factors that cause changes in the characteristics of noise in the channel, up to the total loss due to some temporary sites. To improve the reliability of transmission and ensure continuous communication with the object, it is proposed to use a multi-channel system to record the TMI. This system consists of several telemetry stations, which simultaneously register data stream transmitted from the telemetry object. The multichannel system generates a single stream of TMI for the user at the output. The stream comprises the most reliable pieces of information, being received at all inputs of the system.The paper investigates the task of constructing a multi-channel registration scheme for telemetry information (TMI to provide a simultaneous reception of the telemeasurement data by multiple telemetry stations and to form a single TMI stream containing the most reliable pieces of received data on the basis of quality analysis of information being received.In a multichannel registering system of TMI there are three main factors affecting the quality of the output of a single stream of information: 1 quality of the method used for protecting against errors during transmission over the communication channel with noise; 2 efficiency of the synchronization process of telemetry frames in the received flow of information; 3 efficiency of the applied criteria to form a single output stream from multiple input streams coming from different stations in the discussed multichannel registering system of TMI.In the paper, in practical

Relativistic Multichannel Treatment of Krypton Spectra across the First Ionization Threshold

Institute of Scientific and Technical Information of China (English)

QU Yi-Zhi; PENG Yong-Lun

2005-01-01

@@ The relativistic multichannel theory has been extended to calculate both the eigen quantum defects μα, transformation matrix Uiα, and the eigen dipole matrix elements Dα of krypton. The Rydberg and autoionizationspectra of krypton across the first ionization threshold are calculated within the framework of multichannel quantum defect theory. Our calculated spectra are in agreement with the absolute measurement data.

Imaging of underground karst water channels using an improved multichannel transient Rayleigh wave detecting method.

Science.gov (United States)

Zheng, Xuhui; Liu, Lei; Sun, Jinzhong; Li, Gao; Zhou, Fubiao; Xu, Jiemin

2018-01-01

Geological and hydrogeological conditions in karst areas are complicated from the viewpoint of engineering. The construction of underground structures in these areas is often disturbed by the gushing of karst water, which may delay the construction schedule, result in economic losses, and even cause heavy casualties. In this paper, an innovative method of multichannel transient Rayleigh wave detecting is proposed by introducing the concept of arrival time difference phase between channels (TDP). Overcoming the restriction of the space-sampling law, the proposed method can extract the phase velocities of different frequency components from only two channels of transient Rayleigh wave recorded on two adjacent detecting points. This feature greatly improves the work efficiency and lateral resolution of transient Rayleigh wave detecting. The improved multichannel transient Rayleigh wave detecting method is applied to the detection of karst caves and fractures in rock mass of the foundation pit of Yan'an Road Station of Guiyang Metro. The imaging of the detecting results clearly reveals the distribution of karst water inflow channels, which provided significant guidance for water plugging and enabled good control over karst water gushing in the foundation pit.

Multichannel imager for littoral zone characterization

Science.gov (United States)

Podobna, Yuliya; Schoonmaker, Jon; Dirbas, Joe; Sofianos, James; Boucher, Cynthia; Gilbert, Gary

2010-04-01

This paper describes an approach to utilize a multi-channel, multi-spectral electro-optic (EO) system for littoral zone characterization. Advanced Coherent Technologies, LLC (ACT) presents their EO sensor systems for the surf zone environmental assessment and potential surf zone target detection. Specifically, an approach is presented to determine a Surf Zone Index (SZI) from the multi-spectral EO sensor system. SZI provides a single quantitative value of the surf zone conditions delivering an immediate understanding of the area and an assessment as to how well an airborne optical system might perform in a mine countermeasures (MCM) operation. Utilizing consecutive frames of SZI images, ACT is able to measure variability over time. A surf zone nomograph, which incorporates targets, sensor, and environmental data, including the SZI to determine the environmental impact on system performance, is reviewed in this work. ACT's electro-optical multi-channel, multi-spectral imaging system and test results are presented and discussed.

High-frequency Rayleigh-wave method

Science.gov (United States)

Xia, J.; Miller, R.D.; Xu, Y.; Luo, Y.; Chen, C.; Liu, J.; Ivanov, J.; Zeng, C.

2009-01-01

High-frequency (???2 Hz) Rayleigh-wave data acquired with a multichannel recording system have been utilized to determine shear (S)-wave velocities in near-surface geophysics since the early 1980s. This overview article discusses the main research results of high-frequency surface-wave techniques achieved by research groups at the Kansas Geological Survey and China University of Geosciences in the last 15 years. The multichannel analysis of surface wave (MASW) method is a non-invasive acoustic approach to estimate near-surface S-wave velocity. The differences between MASW results and direct borehole measurements are approximately 15% or less and random. Studies show that simultaneous inversion with higher modes and the fundamental mode can increase model resolution and an investigation depth. The other important seismic property, quality factor (Q), can also be estimated with the MASW method by inverting attenuation coefficients of Rayleigh waves. An inverted model (S-wave velocity or Q) obtained using a damped least-squares method can be assessed by an optimal damping vector in a vicinity of the inverted model determined by an objective function, which is the trace of a weighted sum of model-resolution and model-covariance matrices. Current developments include modeling high-frequency Rayleigh-waves in near-surface media, which builds a foundation for shallow seismic or Rayleigh-wave inversion in the time-offset domain; imaging dispersive energy with high resolution in the frequency-velocity domain and possibly with data in an arbitrary acquisition geometry, which opens a door for 3D surface-wave techniques; and successfully separating surface-wave modes, which provides a valuable tool to perform S-wave velocity profiling with high-horizontal resolution. ?? China University of Geosciences (Wuhan) and Springer-Verlag GmbH 2009.

Effects of intermediate frequency magnetic fields on male fertility indicators in mice.

Science.gov (United States)

Kumari, K; Capstick, M; Cassara, A M; Herrala, M; Koivisto, H; Naarala, J; Tanila, H; Viluksela, M; Juutilainen, J

2017-08-01

Human exposure to intermediate frequency (IF) fields is increasing due to new applications such as electronic article surveillance systems, wireless power transfer and induction heating cookers. However, limited data is available on effects of IF magnetic fields (MF) on male fertility function. This study was conducted to assess possible effects on fertility indicators from exposure to IF MF. Male C57BL/6J mice were exposed continuously for 5 weeks to 7.5kHz MF at 12 and 120μT. Sperm cells from cauda epididymis were analysed for motility, total sperm counts, and head abnormalities. Motile sperm cells were classified as progressive or non-progressive. Testicular spermatid heads were counted as well. The body weight development and reproductive tissue weights were not affected. No exposure-related differences were observed in sperm counts or sperm head abnormalities. Proportion of non-motile cells was significantly decreased in the 120µT group, and a corresponding increase was seen in the percentage of motile cells (significant in non-progressive motile cells). In conclusion, no adverse effects on fertility indicators were observed. Increased sperm motility is an interesting finding that needs to be confirmed in further studies. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Evaluation of Multi-Channel ADCs for Gamma-Ray Spectroscopy

Science.gov (United States)

Tan, Hui; Hennig, Wolfgang; Walby, Mark D.; Breus, Dimitry; Harris, Jackson

2013-04-01

As nuclear physicists increasingly design large scale experiments with hundreds or thousands of detector channels, there are growing needs for high density readout electronics with good timing and energy resolution that at the same time offer lower cost per channel compared to existing commercial solutions. Recent improvements in the design of commercial analog to digital converters (ADCs) have resulted in a variety of multi-channel ADCs that are natural choice for designing such high density readout modules. However, multi-channel ADCs typically are designed for medical imaging/ultrasound applications and therefore are not rated for their spectroscopic characteristics. In this work, we evaluated the gamma-ray spectroscopic performance of several multi-channel ADCs, including their energy resolution, nonlinearity, and timing resolution. Some of these ADCs demonstrated excellent energy resolution, 2.66% FWHM at 662 keV with a LaBr3 or 1.78 keV FWHM at 1332.5 keV with a high purity germanium (HPGe) detector, and sub-nanosecond timing resolution with LaBr 3. We present results from these measurements to illustrate their suitability for gamma-ray spectroscopy.

Design of multichannel counting system for IBM PC and compatibles

International Nuclear Information System (INIS)

Majeed, B.; Ahmad, Z.; Osman, A.; Ysain, M.M.

1995-07-01

A Multichannel Counting System (MCCS), based on IBM-PC and compatible computer systems have been designed. The MCCS consists of a Multichannel Counting System plug-in interface card (MCCS-PC) for IBM PC and compatibles and a NIM-BIN module (MCCS-NB). The MCCS-PC provides simultaneous monitoring of upto seven independent SCA type inputs. An on board programmable timer provides elapsed time measurement. A menu-driven program for data acquisition and timer control has also been developed. (author) 8 figs

Artificial Walking Technologies to Improve Gait in Cerebral Palsy: Multichannel Neuromuscular Stimulation.

Science.gov (United States)

Rose, Jessica; Cahill-Rowley, Katelyn; Butler, Erin E

2017-11-01

Cerebral palsy (CP) is the most common childhood motor disability and often results in debilitating walking abnormalities, such as flexed-knee and stiff-knee gait. Current medical and surgical treatments are only partially effective in improving gait abnormalities and may cause significant muscle weakness. However, emerging artificial walking technologies, such as step-initiated, multichannel neuromuscular electrical stimulation (NMES), can substantially improve gait patterns and promote muscle strength in children with spastic CP. NMES may also be applied to specific lumbar-sacral sensory roots to reduce spasticity. Development of tablet computer-based multichannel NMES can leverage lightweight, wearable wireless stimulators, advanced control design, and surface electrodes to activate lower-limb muscles. Musculoskeletal models have been used to characterize muscle contributions to unimpaired gait and identify high muscle demands, which can help guide multichannel NMES-assisted gait protocols. In addition, patient-specific NMES-assisted gait protocols based on 3D gait analysis can facilitate the appropriate activation of lower-limb muscles to achieve a more functional gait: stance-phase hip and knee extension and swing-phase sequence of hip and knee flexion followed by rapid knee extension. NMES-assisted gait treatment can be conducted as either clinic-based or home-based programs. Rigorous testing of multichannel NMES-assisted gait training protocols will determine optimal treatment dosage for future clinical trials. Evidence-based outcome evaluation using 3D kinematics or temporal-spatial gait parameters will help determine immediate neuroprosthetic effects and longer term neurotherapeutic effects of step-initiated, multichannel NMES-assisted gait in children with spastic CP. Multichannel NMES is a promising assistive technology to help children with spastic CP achieve a more upright, functional gait. © 2017 International Center for Artificial Organs and

Research on digital multi-channel pulse height analysis techniques

International Nuclear Information System (INIS)

Xiao Wuyun; Wei Yixiang; Ai Xianyun; Ao Qi

2005-01-01

Multi-channel pulse height analysis techniques are developing in the direction of digitalization. Based on digital signal processing techniques, digital multi-channel analyzers are characterized by powerful pulse processing ability, high throughput, improved stability and flexibility. This paper analyzes key techniques of digital nuclear pulse processing. With MATLAB software, main algorithms are simulated, such as trapezoidal shaping, digital baseline estimation, digital pole-zero/zero-pole compensation, poles and zeros identification. The preliminary general scheme of digital MCA is discussed, as well as some other important techniques about its engineering design. All these lay the foundation of developing homemade digital nuclear spectrometers. (authors)

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.

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.

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

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

Multichannel sound reinforcement systems at work in a learning environment

Science.gov (United States)

Malek, John; Campbell, Colin

2003-04-01

Many people have experienced the entertaining benefits of a surround sound system, either in their own home or in a movie theater, but another application exists for multichannel sound that has for the most part gone unused. This is the application of multichannel sound systems to the learning environment. By incorporating a 7.1 surround processor and a touch panel interface programmable control system, the main lecture hall at the University of Michigan Taubman College of Architecture and Urban Planning has been converted from an ordinary lecture hall to a working audiovisual laboratory. The multichannel sound system is used in a wide variety of experiments, including exposure to sounds to test listeners' aural perception of the tonal characteristics of varying pitch, reverberation, speech transmission index, and sound-pressure level. The touch panel's custom interface allows a variety of user groups to control different parts of the AV system and provides preset capability that allows for numerous system configurations.

A software tool for analyzing multichannel cochlear implant signals.

Science.gov (United States)

Lai, Wai Kong; Bögli, Hans; Dillier, Norbert

2003-10-01

A useful and convenient means to analyze the radio frequency (RF) signals being sent by a speech processor to a cochlear implant would be to actually capture and display them with appropriate software. This is particularly useful for development or diagnostic purposes. sCILab (Swiss Cochlear Implant Laboratory) is such a PC-based software tool intended for the Nucleus family of Multichannel Cochlear Implants. Its graphical user interface provides a convenient and intuitive means for visualizing and analyzing the signals encoding speech information. Both numerical and graphic displays are available for detailed examination of the captured CI signals, as well as an acoustic simulation of these CI signals. sCILab has been used in the design and verification of new speech coding strategies, and has also been applied as an analytical tool in studies of how different parameter settings of existing speech coding strategies affect speech perception. As a diagnostic tool, it is also useful for troubleshooting problems with the external equipment of the cochlear implant systems.

Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion

Directory of Open Access Journals (Sweden)

Dong-Gun Kim

Full Text Available Objectives: Anterior cervical discectomy and fusion (ACDF surgery is the most common surgical procedure for the cervical spine with low complication rate. Despite the potential prognostic benefit, intraoperative neurophysiological monitoring (IONM, a method for detecting impending neurological compromise, is not routinely used in ACDF surgery. The present study aimed to identify the potential benefits of monitoring multi-channel motor evoked potentials (MEPs during ACDF surgery. Methods: We retrospectively reviewed 200 consecutive patients who received IONM with multi-channel MEPs and somatosensory evoked potentials (SSEPs. On average, 9.2 muscles per patient were evaluated under MEP monitoring. Results: The rate of MEP change during surgery in the multi-level ACDF group was significantly higher than the single-level group. Two patients from the single-level ACDF group (1.7% and four patients from the multi-level ACDF group (4.9% experienced post-operative motor deficits. Multi-channel MEPs monitoring during single and multi-level ACDF surgery demonstrated higher sensitivity, specificity, positive predictive and negative predictive value than SSEP monitoring. Conclusions: Multi-channel MEP monitoring might be beneficial for the detection of segmental injury as well as long tract injury during single- and multi-level ACDF surgery. Significance: This is first large scale study to identify the usefulness of multi-channel MEPs in monitoring ACDF surgery. Keywords: Disc disease, Somatosensory evoked potentials, Intraoperative neurophysiological monitoring, Motor evoked potentials, Anterior cervical discectomy and fusion

Recording and processing procedures for multi-channel seismic-reflection data collected in the western Ross Sea, Antarctica

Science.gov (United States)

Dadisman, Shawn V.; Ryan, Holly F.; Mann, Dennis M.

1987-01-01

During 1984, over 2300 km of multichannel seismic-reflection data were recorded by the U.S. Geological Survey in the western Ross Sea and Iselin Bank regions.  A temporary loss and sinking of the streamer led to increasing the streamer tow depth to 20 m, which resulted in some attenuation of frequencies in the 30-50 Hz range but no significant difference in resolution of the stacked data.  Severe water bottom multiples were encountered and removed by dip-filtering, weighted stacking, and severe post-NMO muting.

Multichannel analyzer based on microprocessors

International Nuclear Information System (INIS)

Soares, M.

1983-06-01

A multichannel analyser for nuclear spectrometry, that would attend the needs of research laboratories and could be industrialized in Brazil, was developed. The design was based on INTEL 8080/85 microprocessors; other processors were also used to implement specific functions, such as shared busbar using direct memory access. A prototype was developed and tested through simulation, using a nuclear spectrometry chain. The results were fully satisfactory. (Author) [pt

Spectral signatures for swash on reflective, intermediate and dissipative beaches

DEFF Research Database (Denmark)

Hughes, Michael G; Aagaard, Troels; Baldock, Tom E

2014-01-01

(reflective, intermediate and dissipative), with beach gradients ranging from approximately 1:6 to 1:60 exposed to offshore significant wave heights of 0.5–3.0 m. The ratio of swash energy in the short-wave (f > 0.05 Hz) to long-wave (f ... the three beach types. Swash energy at short-wave frequencies is dominant on reflective and intermediate beaches and swash at long-wave frequencies is dominant on dissipative beaches; consistent with previously reported spectral signatures for the surf zone on these beach types. The available swash spectra...

Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Waqas Rehan

2016-09-01

Full Text Available Wireless sensor networks (WSNs have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM, that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI and the average of the link quality indicator (LQI of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC algorithm in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC algorithm, that can perform channel quality estimation on the basis of both current and past values of channel rank estimation

Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks.

Science.gov (United States)

Rehan, Waqas; Fischer, Stefan; Rehan, Maaz

2016-09-12

Wireless sensor networks (WSNs) have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM), that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI) and the average of the link quality indicator (LQI) of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC) algorithm) in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC) algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC) algorithm), that can perform channel quality estimation on the basis of both current and past values of channel rank estimation. In the end

Multichannel brain recordings in behaving Drosophila reveal oscillatory activity and local coherence in response to sensory stimulation and circuit activation

Science.gov (United States)

Paulk, Angelique C.; Zhou, Yanqiong; Stratton, Peter; Liu, Li

2013-01-01

Neural networks in vertebrates exhibit endogenous oscillations that have been associated with functions ranging from sensory processing to locomotion. It remains unclear whether oscillations may play a similar role in the insect brain. We describe a novel “whole brain” readout for Drosophila melanogaster using a simple multichannel recording preparation to study electrical activity across the brain of flies exposed to different sensory stimuli. We recorded local field potential (LFP) activity from >2,000 registered recording sites across the fly brain in >200 wild-type and transgenic animals to uncover specific LFP frequency bands that correlate with: 1) brain region; 2) sensory modality (olfactory, visual, or mechanosensory); and 3) activity in specific neural circuits. We found endogenous and stimulus-specific oscillations throughout the fly brain. Central (higher-order) brain regions exhibited sensory modality-specific increases in power within narrow frequency bands. Conversely, in sensory brain regions such as the optic or antennal lobes, LFP coherence, rather than power, best defined sensory responses across modalities. By transiently activating specific circuits via expression of TrpA1, we found that several circuits in the fly brain modulate LFP power and coherence across brain regions and frequency domains. However, activation of a neuromodulatory octopaminergic circuit specifically increased neuronal coherence in the optic lobes during visual stimulation while decreasing coherence in central brain regions. Our multichannel recording and brain registration approach provides an effective way to track activity simultaneously across the fly brain in vivo, allowing investigation of functional roles for oscillations in processing sensory stimuli and modulating behavior. PMID:23864378

Multichannel brain recordings in behaving Drosophila reveal oscillatory activity and local coherence in response to sensory stimulation and circuit activation.

Science.gov (United States)

Paulk, Angelique C; Zhou, Yanqiong; Stratton, Peter; Liu, Li; van Swinderen, Bruno

2013-10-01

Neural networks in vertebrates exhibit endogenous oscillations that have been associated with functions ranging from sensory processing to locomotion. It remains unclear whether oscillations may play a similar role in the insect brain. We describe a novel "whole brain" readout for Drosophila melanogaster using a simple multichannel recording preparation to study electrical activity across the brain of flies exposed to different sensory stimuli. We recorded local field potential (LFP) activity from >2,000 registered recording sites across the fly brain in >200 wild-type and transgenic animals to uncover specific LFP frequency bands that correlate with: 1) brain region; 2) sensory modality (olfactory, visual, or mechanosensory); and 3) activity in specific neural circuits. We found endogenous and stimulus-specific oscillations throughout the fly brain. Central (higher-order) brain regions exhibited sensory modality-specific increases in power within narrow frequency bands. Conversely, in sensory brain regions such as the optic or antennal lobes, LFP coherence, rather than power, best defined sensory responses across modalities. By transiently activating specific circuits via expression of TrpA1, we found that several circuits in the fly brain modulate LFP power and coherence across brain regions and frequency domains. However, activation of a neuromodulatory octopaminergic circuit specifically increased neuronal coherence in the optic lobes during visual stimulation while decreasing coherence in central brain regions. Our multichannel recording and brain registration approach provides an effective way to track activity simultaneously across the fly brain in vivo, allowing investigation of functional roles for oscillations in processing sensory stimuli and modulating behavior.

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

Wavelet compression of multichannel ECG data by enhanced set partitioning in hierarchical trees algorithm.

Science.gov (United States)

Sharifahmadian, Ershad

2006-01-01

The set partitioning in hierarchical trees (SPIHT) algorithm is very effective and computationally simple technique for image and signal compression. Here the author modified the algorithm which provides even better performance than the SPIHT algorithm. The enhanced set partitioning in hierarchical trees (ESPIHT) algorithm has performance faster than the SPIHT algorithm. In addition, the proposed algorithm reduces the number of bits in a bit stream which is stored or transmitted. I applied it to compression of multichannel ECG data. Also, I presented a specific procedure based on the modified algorithm for more efficient compression of multichannel ECG data. This method employed on selected records from the MIT-BIH arrhythmia database. According to experiments, the proposed method attained the significant results regarding compression of multichannel ECG data. Furthermore, in order to compress one signal which is stored for a long time, the proposed multichannel compression method can be utilized efficiently.

Computationally Developed Sham Stimulation Protocol for Multichannel Desynchronizing Stimulation

Directory of Open Access Journals (Sweden)

Magteld Zeitler

2018-05-01

Full Text Available A characteristic pattern of abnormal brain activity is abnormally strong neuronal synchronization, as found in several brain disorders, such as tinnitus, Parkinson's disease, and epilepsy. As observed in several diseases, different therapeutic interventions may induce a placebo effect that may be strong and hinder reliable clinical evaluations. Hence, to distinguish between specific, neuromodulation-induced effects and unspecific, placebo effects, it is important to mimic the therapeutic procedure as precisely as possibly, thereby providing controls that actually lack specific effects. Coordinated Reset (CR stimulation has been developed to specifically counteract abnormally strong synchronization by desynchronization. CR is a spatio-temporally patterned multichannel stimulation which reduces the extent of coincident neuronal activity and aims at an anti-kindling, i.e., an unlearning of both synaptic connectivity and neuronal synchrony. Apart from acute desynchronizing effects, CR may cause sustained, long-lasting desynchronizing effects, as already demonstrated in pre-clinical and clinical proof of concept studies. In this computational study, we set out to computationally develop a sham stimulation protocol for multichannel desynchronizing stimulation. To this end, we compare acute effects and long-lasting effects of six different spatio-temporally patterned stimulation protocols, including three variants of CR, using a no-stimulation condition as additional control. This is to provide an inventory of different stimulation algorithms with similar fundamental stimulation parameters (e.g., mean stimulation rates but qualitatively different acute and/or long-lasting effects. Stimulation protocols sharing basic parameters, but inducing nevertheless completely different or even no acute effects and/or after-effects, might serve as controls to validate the specific effects of particular desynchronizing protocols such as CR. In particular, based on

On the use of A PCA as a multichannel time analyzer

International Nuclear Information System (INIS)

Adib, M.; Abdelkawy, A.; Abuelela, M.; Habib, N.; Wahba, M.; Salama, F.

1992-01-01

PCA and PCA-11 software programmes have been used to utilize the operation of the nucleus personal computer analyzer PCA-8000 in its multichannel scaler (MCS) mode. The operating condition of PCA-8000 were selected to match the time-of-flight (TOF) spectrometer which is in operation at the ET-RR-1 reactor. The results of measuring the main parameters of PCA-8000 operating in its MCS mode showed that it can be successfully used as a multichannel time analyzer.5 fig

Multichannel CdZnTe Gamma Ray Spectrometer

International Nuclear Information System (INIS)

Doty, F.P.; Lingren, C. L.; Apotovsky, B. A.; Brunsch, J.; Butler, J. F.; Collins, T.; Conwell, R.L.; Friesenhahn, S.; Gormley, J.; Pi, B.; Zhao, S.; Augustine, F.L.; Bennet, B. A.; Cross, E.; James, R. B.

1998-01-01

A 3 cm 3 multichannel gamma spectrometer for DOE applications is under development by Digirad Corporation. The device is based on a position sensitive detector packaged in a compact multi-chip module (MCM) with integrated readout circuitry. The modular, multichannel design will enable identification and quantitative analysis of radionuclides in extended sources, or sources containing low levels of activity. The MCM approach has the advantages that the modules are designed for imaging applications, and the sensitivity can be arbitrarily increased by increasing the number of pixels, i.e. adding modules to the instrument. For a high sensitivity probe, the outputs for each pixel can be corrected for gain and offset variations, and summed digitally. Single pixel results obtained with discrete low noise readout indicate energy resolution of 3 keV can be approached with currently available CdZnTe. The energy resolution demonstrated to date with MCMs for 511 keV gamma rays is 10 keV

Multichannel High Resolution Wide Swath SAR Imaging for Hypersonic Air Vehicle with Curved Trajectory

Directory of Open Access Journals (Sweden)

Rui Zhou

2018-01-01

Full Text Available Synthetic aperture radar (SAR equipped on the hypersonic air vehicle in near space has many advantages over the conventional airborne SAR. However, its high-speed maneuvering characteristics with curved trajectory result in serious range migration, and exacerbate the contradiction between the high resolution and wide swath. To solve this problem, this paper establishes the imaging geometrical model matched with the flight trajectory of the hypersonic platform and the multichannel azimuth sampling model based on the displaced phase center antenna (DPCA technology. Furthermore, based on the multichannel signal reconstruction theory, a more efficient spectrum reconstruction model using discrete Fourier transform is proposed to obtain the azimuth uniform sampling data. Due to the high complexity of the slant range model, it is difficult to deduce the processing algorithm for SAR imaging. Thus, an approximate range model is derived based on the minimax criterion, and the optimal second-order approximate coefficients of cosine function are obtained using the two-population coevolutionary algorithm. On this basis, aiming at the problem that the traditional Omega-K algorithm cannot compensate the residual phase with the difficulty of Stolt mapping along the range frequency axis, this paper proposes an Exact Transfer Function (ETF algorithm for SAR imaging, and presents a method of range division to achieve wide swath imaging. Simulation results verify the effectiveness of the ETF imaging algorithm.

Multichannel High Resolution Wide Swath SAR Imaging for Hypersonic Air Vehicle with Curved Trajectory.

Science.gov (United States)

Zhou, Rui; Sun, Jinping; Hu, Yuxin; Qi, Yaolong

2018-01-31

Synthetic aperture radar (SAR) equipped on the hypersonic air vehicle in near space has many advantages over the conventional airborne SAR. However, its high-speed maneuvering characteristics with curved trajectory result in serious range migration, and exacerbate the contradiction between the high resolution and wide swath. To solve this problem, this paper establishes the imaging geometrical model matched with the flight trajectory of the hypersonic platform and the multichannel azimuth sampling model based on the displaced phase center antenna (DPCA) technology. Furthermore, based on the multichannel signal reconstruction theory, a more efficient spectrum reconstruction model using discrete Fourier transform is proposed to obtain the azimuth uniform sampling data. Due to the high complexity of the slant range model, it is difficult to deduce the processing algorithm for SAR imaging. Thus, an approximate range model is derived based on the minimax criterion, and the optimal second-order approximate coefficients of cosine function are obtained using the two-population coevolutionary algorithm. On this basis, aiming at the problem that the traditional Omega-K algorithm cannot compensate the residual phase with the difficulty of Stolt mapping along the range frequency axis, this paper proposes an Exact Transfer Function (ETF) algorithm for SAR imaging, and presents a method of range division to achieve wide swath imaging. Simulation results verify the effectiveness of the ETF imaging algorithm.

Multichannel singular spectrum analysis of the axial atmospheric angular momentum

Directory of Open Access Journals (Sweden)

Leonid Zotov

2017-11-01

Full Text Available Earth's variable rotation is mainly produced by the variability of the AAM (atmospheric angular momentum. In particular, the axial AAM component χ3, which undergoes especially strong variations, induces changes in the Earth's rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD (length of day were described. We applied MSSA (Multichannel Singular Spectrum Analysis jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-month, quasi-biennial, 5-year, and low-frequency oscillations. PCs (Principal components strongly related to ENSO (El Nino southern oscillation were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.

SU-E-T-10: A Clinical Implementation and the Dosimetric Evidence in High Dose Rate Vaginal Multichannel Applicator Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Syh, J; Syh, J; Patel, B; Zhang, J; Wu, H; Rosen, L [Willis-Knighton Medical Center, Shreveport, LA (United States)

2015-06-15

Purpose: The multichannel cylindrical applicator has a distinctive modification of the traditional single channel cylindrical applicator. The novel multichannel applicator has additional peripheral channels that provide more flexibility both in treatment planning process and outcomes. To protect by reducing doses to adjacent organ at risk (OAR) while maintaining target coverage with inverse plan optimization are the goals for such novel Brachytherapy device. Through a series of comparison and analysis of reults in more than forty patients who received HDR Brachytherapy using multichannel vaginal applicator, this procedure has been implemented in our institution. Methods: Multichannel planning was CT image based. The CTV of 5mm vaginal cuff rind with prescribed length was well reconstructed as well as bladder and rectum. At least D95 of CTV coverage is 95% of prescribed dose. Multichannel inverse plan optimization algorithm not only shapes target dose cloud but set dose avoids to OAR’s exclusively. The doses of D2cc, D5cc and D5; volume of V2Gy in OAR’s were selected to compare with single channel results when sole central channel is only possibility. Results: Study demonstrates plan superiorly in OAR’s doe reduction in multi-channel plan. The D2cc of the rectum and bladder were showing a little lower for multichannel vs. single channel. The V2Gy of the rectum was 93.72% vs. 83.79% (p=0.007) for single channel vs. multichannel respectively. Absolute reduced mean dose of D5 by multichannel was 17 cGy (s.d.=6.4) and 44 cGy (s.d.=15.2) in bladder and rectum respectively. Conclusion: The optimization solution in multichannel was to maintain D95 CTV coverage while reducing the dose to OAR’s. Dosimetric advantage in sparing critical organs by using a multichannel applicator in HDR Brachytherapy treatment of the vaginal cuff is so promising and has been implemented clinically.

Generation of frequency-chirped optical pulses with felix

Energy Technology Data Exchange (ETDEWEB)

Knippels, G.M.H.; Meer, A.F.G. van der; Mols, R.F.X.A.M. [FOM-Institute for Plasma Physics, Nieuwegein (Netherlands)] [and others

1995-12-31

Frequency-chirped optical pulses have been produced in the picosecond regime by varying the energy of the electron beam on a microsecond time scale. These pulses were then compressed close to their bandwidth limit by an external pulse compressor. The amount of chirp can be controlled by varying the sweep rate on the electron beam energy and by cavity desynchronisation. To examine the generated chirp we used the following diagnostics: a pulse compressor, a crossed beam autocorrelator, a multichannel electron spectrometer and multichannel optical spectrometer. The compressor is build entirely using reflective optics to permit broad band operation. The autocorrelator is currently operating from 6 {mu}m to 30 {mu}m with one single crystal. It has been used to measure pulses as short as 500 fs. All diagnostics are evacuated to prevent pulse shape distortion or pulse lengthening caused by absorption in ambient water vapour. Pulse length measurements and optical spectra will be presented for different electron beam sweep rates, showing the presence of a frequency chirp. Results on the compression of the optical pulses to their bandwidth limit are given for different electron sweep rates. More experimental results showing the dependence of the amount of chirp on cavity desynchronisation will be presented.

Research on Multichannel Test Device of Missile Fuze

Directory of Open Access Journals (Sweden)

Guoyong Zhen

2014-05-01

Full Text Available This paper introduces the design of multichannel acquisition circuit based on FPGA which samples and records the Doppler signals, ignition signal and the working condition of fuze security enforcement agencies of missile fuze in real-time in the test of high speed dynamic intersection. Furthermore, for the problem of increasing number of sample channel which causes the complexity of the multiplexer control, a general programmable channel switching method is proposed based on FPGA. In the method, FPGA is the control core, and using the internal ROM resource effectively simplifies the complexity of channel switch in the multichannel acquisition system. This paper analyzes the acquisition system design, and describes the design of hardware circuit and analog switch address coding in detail. The test result shows that the acquisition circuit meets the design requirements with high sampling precision and application value.

Recent advances in Multi-Channel Algebraic Scattering

International Nuclear Information System (INIS)

Karataglidis, S.; Fraser, P. R.; Amos, K.; Canton, L.; Pisent, G.; Svenne, J. P.; Knijff, D. van der

2011-01-01

For coupled-channel descriptions of low-energy nucleon-induced interactions involving nuclei with particle-unstable exited states, it is necessary to include the widths of the target states. How those widths may affect the elastic scattering cross sections is examined within the framework of the Multi-Channel Algebraic Scattering (MCAS) method.

A multi-channel magnetic induction tomography measurement system for human brain model imaging

International Nuclear Information System (INIS)

Xu, Zheng; Luo, Haijun; He, Wei; He, Chuanhong; Song, Xiaodong; Zahng, Zhanglong

2009-01-01

This paper proposes a multi-channel magnetic induction tomography measurement system for biological conductivity imaging in a human brain model. A hemispherical glass bowl filled with a salt solution is used as the human brain model; meanwhile, agar blocks of different conductivity are placed in the solution to simulate the intracerebral hemorrhage. The excitation and detection coils are fixed co-axially, and the axial gradiometer is used as the detection coil in order to cancel the primary field. On the outer surface of the glass bowl, 15 sensor units are arrayed in two circles as measurement parts, and a single sensor unit for canceling the phase drift is placed beside the glass bowl. The phase sensitivity of our system is 0.204°/S m −1 with the excitation frequency of 120 kHz and the phase noise is in the range of −0.03° to +0.05°. Only the coaxial detection coil is available for each excitation coil; therefore, 15 phase data are collected in each measurement turn. Finally, the two-dimensional images of conductivity distribution are obtained using an interpolation algorithm. The frequency-varying experiment indicates that the imaging quality becomes better as the excitation frequency is increased

Data processing for the multichannel pulse height analysis system ND-50/50, (1)

International Nuclear Information System (INIS)

Katagiri, Masaki

1977-03-01

The multichannel pulse height analysis system ND-50/50 manufactured by Nuclear Data Inc. consists of a 4096 channel pulse height analyzer and a small computer PDP-8/L (Digital Equipment Corporation). A conversational interpretive language, MACAL (Multichannel Analyzer CALculator) has been developed to analyze gamma-ray spectra in ND-50/50. It is a modification of the FOCAL (FOrmula CALculator) language of Digital Equipment Corporation. MACAL consists of imperative English commands and mathematical expressions, and has standard mathematical functions and functions for controlling the multichannel pulse height analyzer and I/O devices (high-speed reader, high-speed punch, and digital plotter). With MACAL, the following five programs were prepared : 1) program for controlling the multichannel pulse height analyzer and data handling, 2) program for automatically analyzing gamma-ray spectra obtained by germanium detectors, 3) program for automatically measuring characteristics of germanium detectors, 4) program for calculating the center energy of gamma-ray peaks, and 5) program for plotting the pulse height distribution and diagraming the results obtained with the programs. By combining the programs according to experimental purposes, the system can be highly effective. (auth.)

Software for a multichannel acquisition card

International Nuclear Information System (INIS)

Arista Romeu, E. J.; Diaz Garcia, A.; Vela Morales, O.

2013-01-01

A software developed in C++ for a multichannel acquisition card is presented. The use of an acquisition add-on card with multiple channels is a suitable solution to substitute several instruments, allowing simultaneous acquisition with each channel. In this work, the limitations of a concrete hardware are discussed and also several different approaches have been suggested. Some preliminary results obtained in laboratory conditions are shown. (Author)

A multi-channel waveform digitizer system

International Nuclear Information System (INIS)

Bieser, F.; Muller, W.F.J.

1990-01-01

The authors report on the design and performance of a multichannel waveform digitizer system for use with the Multiple Sample Ionization Chamber (MUSIC) Detector at the Bevalac. 128 channels of 20 MHz Flash ADC plus 256 word deep memory are housed in a single crate. Digital thresholds and hit pattern logic facilitate zero suppression during readout which is performed over a standard VME bus

Analysis of the features of untrained human movements based on the multichannel EEG for controlling anthropomorphic robotic arm

Science.gov (United States)

Maksimenko, Vladimir; Runnova, Anastasia; Pchelintseva, Svetlana; Efremova, Tatiana; Zhuravlev, Maksim; Pisarchik, Alexander

2018-04-01

We have considered time-frequency and spatio-temporal structure of electrical brain activity, associated with real and imaginary movements based on the multichannel EEG recordings. We have found that along with wellknown effects of event-related desynchronization (ERD) in α/μ - rhythms and β - rhythm, these types of activity are accompanied by the either ERS (for real movement) or ERD (for imaginary movement) in low-frequency δ - band, located mostly in frontal lobe. This may be caused by the associated processes of decision making, which take place when subject is deciding either perform the movement or imagine it. Obtained features have been found in untrained subject which it its turn gives the possibility to use our results in the development of brain-computer interfaces for controlling anthropomorphic robotic arm.

Evidence of echoic memory with a multichannel cochlear prosthesis.

Science.gov (United States)

Jerger, S; Watkins, M J

1988-10-01

Short-term memory was examined in a subject with a multichannel cochlear prosthesis. Serial recall for lists of digits revealed what are widely regarded as the principal hallmarks of echoic memory, namely the recency effect and the suffix effect. Thus, probability of recall increased for the last one or two digits, except when a nominally irrelevant but spoken item was appended to the to-be-remembered list. It appears, therefore, that a multichannel cochlear implant can give rise to not only the perception of, but also an echoic memory for, speech. As with normal subjects, the suffix effect did not occur with a nonspeech suffix, implying that the echoic memory from the prosthesis shows normal sensitivity to the distinction between speech and nonspeech.

Organization of a multichannel analyzer for gamma ray spectrometry

International Nuclear Information System (INIS)

Robinet, Genevieve

1988-06-01

This report describes the software organization of a medium scale multichannel analyzer for qualitative and quantitative measurements of the gamma rays emitted by radioactive samples. The first part reminds basis of radioactivity, principle of gamma ray detection, and data processing used for interpretation of a nuclear spectrum. The second part describes first the general organization of the software and then gives some details on interactivity, multidetector capabilites, and integration of complex algorithms for peak search and nuclide identification;problems encountered during the design phase are mentioned and solutions are given. Basic ideas are presented for further developments, such as expert system which should improve interpretation of the results. This present software has been integrated in a manufactured multichannel analyzer named 'POLYGAM NU416'. [fr

Multi-channel grouping techniques for conducting reactor safety studies

International Nuclear Information System (INIS)

Waltar, A.E.; Wilburn, N.P.

1975-01-01

In conducting safety studies for postulated unprotected accidents in an LMFBR system, it is common practice to employ multi-channel coupled neutronics, thermal hydraulics computer programs such as SAS3A or MELT-III. The multichannel feature of such code systems is important if the natural fuel failure incoherencies and the resulting sodium void/fuel motion reactivity feedbacks--which have strong spatial variations--are to be properly modeled. Because of the large amounts of computer time associated with many channel runs, however, there is a strong incentive to conduct parametric studies with as few channels as possible. The paper presented is focused on methods successfully employed to accomplish this end for a study of the hypothetical unprotected transient overpower accident conducted for the FFTF

3m Vacuum Ultraviolet Spectrometer with Optical Multichannel Detector

International Nuclear Information System (INIS)

Martin, P.; Peraza, C.; Blanco, F.; Campos, J.

1993-01-01

This paper describes the design and the performance of a normal incidence vacuum ultraviolet spectrometer, for the 300-2400 A spectral range. It is provided with a multichannel detection system. The monochromator is original design and it has been built at CIEMAT. It is equipped with a 3 m concave holographic grating with 2400 grooves/mm. The multichannel detector consists of a windowless double microchannel plate / phosphor screen image intensifier, coupled by fiber optic to a 1024 elements self-scanning linear photodiode array. The output from the array is digitized by a 12-bit analog to digital converter and stored in a computer, for its later analysis. The necessary software to store and display data has been developed. (Author) 18 refs

Multichannel interval timer

International Nuclear Information System (INIS)

Turko, B.T.

1983-10-01

A CAMAC based modular multichannel interval timer is described. The timer comprises twelve high resolution time digitizers with a common start enabling twelve independent stop inputs. Ten time ranges from 2.5 μs to 1.3 μs can be preset. Time can be read out in twelve 24-bit words either via CAMAC Crate Controller or an external FIFO register. LSB time calibration is 78.125 ps. An additional word reads out the operational status of twelve stop channels. The system consists of two modules. The analog module contains a reference clock and 13 analog time stretchers. The digital module contains counters, logic and interface circuits. The timer has an excellent differential linearity, thermal stability and crosstalk free performance

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.

Evaluation of the potential of soil remediation by direct multi-channel pulsed corona discharge in soil.

Science.gov (United States)

Wang, Tie Cheng; Qu, Guangzhou; Li, Jie; Liang, Dongli

2014-01-15

A novel approach, named multi-channel pulsed corona discharge in soil, was developed for remediating organic pollutants contaminated soil, with p-nitrophenol (PNP) as the model pollutant. The feasibility of PNP degradation in soil was explored by evaluating effects of pulse discharge voltage, air flow rate and soil moisture on PNP degradation. Based on roles of chemically active species and evolution of degradation intermediates, PNP degradation processes were discussed. Experimental results showed that about 89.4% of PNP was smoothly degraded within 60min of discharge treatment at pulse discharge voltage 27kV, soil moisture 5% and air flow rate 0.8Lmin(-1), and the degradation process fitted the first-order kinetic model. Increasing pulse discharge voltage was found to be favorable for PNP degradation, but not for energy yield. There existed appropriate air flow rate and soil moisture for obtaining gratifying PNP degradation efficacy. Roles of radical scavenger and measurement of active species suggested that ozone, H2O2, and OH radicals played very important roles in PNP degradation. CN bond in PNP molecule was cleaved, and the main intermediate products such as hydroquinone, benzoquinone, catechol, phenol, acetic acid, formic acid, oxalic acid, NO2(-) and NO3(-) were identified. Possible pathway of PNP degradation in soil in such a system was proposed. Copyright © 2013 Elsevier B.V. All rights reserved.

Structure of replicating intermediates of human herpesvirus type 6

International Nuclear Information System (INIS)

Severini, Alberto; Sevenhuysen, Claire; Garbutt, Michael; Tipples, Graham A.

2003-01-01

We have studied the structure of the replicative intermediates of human herpesvirus 6 (HHV-6) using pulsed-field gel electrophoresis, partial digestion, two-dimensional gel electrophoresis, and sedimentation centrifugation. The results show that DNA replication of HHV-6 produces head-to-tail concatemeric intermediates as well as approximately equal amounts of circular monomers or oligomers. Unlike the situation in herpes simplex virus, the intermediates of human herpesvirus 6 replication are not highly branched, suggesting a difference in the mechanism of replication or a lower frequency of homologous recombination in human herpesvirus 6 compared to herpes simplex virus

SeismicWaveTool: Continuous and discrete wavelet analysis and filtering for multichannel seismic data

Science.gov (United States)

Galiana-Merino, J. J.; Rosa-Herranz, J. L.; Rosa-Cintas, S.; Martinez-Espla, J. J.

2013-01-01

A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of multichannel seismic data. The considered time-frequency transforms include the continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform. The developed approaches provide a fast and precise time-frequency examination of the seismograms at different frequency bands. Moreover, filtering methods for noise, transients or even baseline removal, are implemented. The primary motivation is to support seismologists with a user-friendly and fast program for the wavelet analysis, providing practical and understandable results. Program summaryProgram title: SeismicWaveTool Catalogue identifier: AENG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 611072 No. of bytes in distributed program, including test data, etc.: 14688355 Distribution format: tar.gz Programming language: MATLAB (MathWorks Inc.) version 7.8.0.347 (R2009a) or higher. Wavelet Toolbox is required. Computer: Developed on a MacBook Pro. Tested on Mac and PC. No computer-specific optimization was performed. Operating system: Any supporting MATLAB (MathWorks Inc.) v7.8.0.347 (R2009a) or higher. Tested on Mac OS X 10.6.8, Windows XP and Vista. Classification: 13. Nature of problem: Numerous research works have developed a great number of free or commercial wavelet based software, which provide specific solutions for the analysis of seismic data. On the other hand, standard toolboxes, packages or libraries, such as the MathWorks' Wavelet Toolbox for MATLAB, offer command line functions and interfaces for the wavelet analysis of one-component signals. Thus, software usually is focused on very specific problems

Front-end electronics for multichannel semiconductor detector systems

CERN Document Server

Grybos, P

2010-01-01

Front-end electronics for multichannel semiconductor detektor systems Volume 08, EuCARD Editorial Series on Accelerator Science and Technology The monograph is devoted to many different aspects related to front-end electronics for semiconductor detector systems, namely: − designing and testing silicon position sensitive detectors for HEP experiments and X-ray imaging applications, − designing and testing of multichannel readout electronics for semiconductor detectors used in X-ray imaging applications, especially for noise minimization, fast signal processing, crosstalk reduction and good matching performance, − optimization of semiconductor detection systems in respect to the effects of radiation damage. The monograph is the result mainly of the author's experience in the above-mentioned areas and it is an attempt of a comprehensive presentation of issues related to the position sensitive detection system working in a single photon counting mode and intended to X-ray imaging applications. The structure...

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.

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.

Multichannel conformal blocks for scattering amplitudes

Science.gov (United States)

Belitsky, A. V.

2018-05-01

By performing resummation of small fermion-antifermion pairs within the pentagon form factor program to scattering amplitudes in planar N = 4 superYang-Mills theory, we construct multichannel conformal blocks within the flux-tube picture for N-sided NMHV polygons. This procedure is equivalent to summation of descendants of conformal primaries in the OPE framework. The resulting conformal partial waves are determined by multivariable hypergeometric series of Lauricella-Saran type.

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.

Software filtering method to suppress spike pulse interference in multi-channel scaler

International Nuclear Information System (INIS)

Huang Shun; Zhao Xiuliang; Li Zhiqiang; Zhao Yanhui

2008-01-01

In the test on anti-jamming function of a multi-channel scaler, we found that the spike pulse interference on the second level counter caused by the motor start-stop operations brings a major count error. There are resolvable characteristics between effective signal and spike pulse interference, and multi-channel hardware filtering circuit is too huge and can't filter thoroughly, therefore we designed a software filtering method. In this method based on C8051F020 MCU, we dynamically store sampling values of one channel in only a one-byte variable and distinguish the rise-trail edge of a signal and spike pulse interference because of value changes of the variable. Test showed that the filtering software method can solve the error counting problem of the multi-channel scaler caused by the motor start-stop operations. The flow chart and source codes of the method were detailed in this paper. (authors)

Multichannel perimetric alterations in systemic lupus erythematosus treated with hydroxychloroquine.

Science.gov (United States)

Piñero, David P; Monllor, Begoña; Camps, Vicente J; de Fez, Dolores

Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. We report the first case of SLE in which visual alterations were evaluated with multichannel perimetry. Some achromatic and color vision alterations may be present in SLE, especially when treated with hydroxychloroquine. The sensitivity losses detected in the chromatic channels in the central zone of the visual field were consistent with the results of the FM 100 Hue color test. Likewise, the multichannel perimetry detected sensitivity losses in the parafoveal area for both chromatic channels, especially for the blue-yellow. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

Efficient Numerical Solution of Coupled Radial Differential Equations in Multichannel Scattering Problems

International Nuclear Information System (INIS)

Houfek, Karel

2008-01-01

Numerical solution of coupled radial differential equations which are encountered in multichannel scattering problems is presented. Numerical approach is based on the combination of the exterior complex scaling method and the finite-elements method with the discrete variable representation. This method can be used not only to solve multichannel scattering problem but also to find bound states and resonance positions and widths directly by diagonalization of the corresponding complex scaled Hamiltonian. Efficiency and accuracy of this method is demonstrated on an analytically solvable two-channel problem.

The design and implementation of a PC based multi-channel scaler system

International Nuclear Information System (INIS)

Wang Qiang; Chinese Academy of Sciences, Beijing; Jin Dapeng; Liu Zhen'an; Zhao Dixin

2007-01-01

A multi-channel scaler system is designed for the system check and status monitoring of the BESIII trigger system. It is composed of a PC, two PCI interface multi-channel scaler cards, the corresponding drivers and user programs. Total 64 signals can be scaled and monitored in real time. The scaled data are recorded locally and some of them are distributed to the online system. In this paper, the hardware structure, software development and long time running stability of the system are introduced. (authors)

Disorder-induced topological transitions in multichannel Majorana wires

NARCIS (Netherlands)

Pekerten, B.; Teker, A.; Bozat, Ö.; Wimmer, M.T.; Adagideli, I

2017-01-01

In this work, we investigate the effect of disorder on the topological properties of multichannel superconductor nanowires. While the standard expectation is that the spectral gap is closed and opened at transitions that change the topological index of the wire, we show that the closing and

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

Multi-channel Analysis of Passive Surface Waves (MAPS)

Science.gov (United States)

Xia, J.; Cheng, F. Mr; Xu, Z.; Wang, L.; Shen, C.; Liu, R.; Pan, Y.; Mi, B.; Hu, Y.

2017-12-01

Urbanization is an inevitable trend in modernization of human society. In the end of 2013 the Chinese Central Government launched a national urbanization plan—"Three 100 Million People", which aggressively and steadily pushes forward urbanization. Based on the plan, by 2020, approximately 100 million people from rural areas will permanently settle in towns, dwelling conditions of about 100 million people in towns and villages will be improved, and about 100 million people in the central and western China will permanently settle in towns. China's urbanization process will run at the highest speed in the urbanization history of China. Environmentally friendly, non-destructive and non-invasive geophysical assessment method has played an important role in the urbanization process in China. Because human noise and electromagnetic field due to industrial life, geophysical methods already used in urban environments (gravity, magnetics, electricity, seismic) face great challenges. But humanity activity provides an effective source of passive seismic methods. Claerbout pointed out that wavefileds that are received at one point with excitation at the other point can be reconstructed by calculating the cross-correlation of noise records at two surface points. Based on this idea (cross-correlation of two noise records) and the virtual source method, we proposed Multi-channel Analysis of Passive Surface Waves (MAPS). MAPS mainly uses traffic noise recorded with a linear receiver array. Because Multi-channel Analysis of Surface Waves can produces a shear (S) wave velocity model with high resolution in shallow part of the model, MPAS combines acquisition and processing of active source and passive source data in a same flow, which does not require to distinguish them. MAPS is also of ability of real-time quality control of noise recording that is important for near-surface applications in urban environment. The numerical and real-world examples demonstrated that MAPS can be

Multi-channel near infrared spectroradiometer

International Nuclear Information System (INIS)

Joseph, G.B.; Biddles, B.J.; D'silva, R.A.; Picot, A.J.; Ackerman, M.J.

1988-01-01

A multichannel spectroradiometer has been developed by Sira Ltd. for the study of rapidly varying events in the near infrared. The instrument is being used in the examination of gun flashes, rocket motor exhaust efflux analysis and ordnance or pyrotechnic flash studies. The spectral range of about 1.4 to 5.2 microns is covered in two bands with the first order dispersion from a pair of ruled blazed gratings being imaged onto a pair of detector arrays. Data may be logged at a rate of 1000 complete spectra per second

Scale-free brain quartet: artistic filtering of multi-channel brainwave music.

Science.gov (United States)

Wu, Dan; Li, Chaoyi; Yao, Dezhong

2013-01-01

To listen to the brain activities as a piece of music, we proposed the scale-free brainwave music (SFBM) technology, which translated scalp EEGs into music notes according to the power law of both EEG and music. In the present study, the methodology was extended for deriving a quartet from multi-channel EEGs with artistic beat and tonality filtering. EEG data from multiple electrodes were first translated into MIDI sequences by SFBM, respectively. Then, these sequences were processed by a beat filter which adjusted the duration of notes in terms of the characteristic frequency. And the sequences were further filtered from atonal to tonal according to a key defined by the analysis of the original music pieces. Resting EEGs with eyes closed and open of 40 subjects were utilized for music generation. The results revealed that the scale-free exponents of the music before and after filtering were different: the filtered music showed larger variety between the eyes-closed (EC) and eyes-open (EO) conditions, and the pitch scale exponents of the filtered music were closer to 1 and thus it was more approximate to the classical music. Furthermore, the tempo of the filtered music with eyes closed was significantly slower than that with eyes open. With the original materials obtained from multi-channel EEGs, and a little creative filtering following the composition process of a potential artist, the resulted brainwave quartet opened a new window to look into the brain in an audible musical way. In fact, as the artistic beat and tonal filters were derived from the brainwaves, the filtered music maintained the essential properties of the brain activities in a more musical style. It might harmonically distinguish the different states of the brain activities, and therefore it provided a method to analyze EEGs from a relaxed audio perspective.

Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment.

Directory of Open Access Journals (Sweden)

Kajal Kumari

Full Text Available Human exposure to intermediate frequency magnetic fields (MF is increasing due to applications like electronic article surveillance systems and induction heating cooking hobs. However, limited data is available on their possible health effects. The present study assessed behavioral and histopathological consequences of exposing mice to 7.5 kHz MF at 12 or 120 μT for 5 weeks. No effects were observed on body weight, spontaneous activity, motor coordination, level of anxiety or aggression. In the Morris swim task, mice in the 120 μT group showed less steep learning curve than the other groups, but did not differ from controls in their search bias in the probe test. The passive avoidance task indicated a clear impairment of memory over 48 h in the 120 μT group. No effects on astroglial activation or neurogenesis were observed in the hippocampus. The mRNA expression of brain-derived neurotrophic factor did not change but expression of the proinflammatory cytokine tumor necrosis factor alpha mRNA was significantly increased in the 120 μT group. These findings suggest that 7.5 kHz MF exposure may lead to mild learning and memory impairment, possibly through an inflammatory reaction in the hippocampus.

Multichannel signal enhancement using a remote wireless microphone

NARCIS (Netherlands)

Bloemendal, Brian; Van De Laar, Jakob; Sommen, Piet

2012-01-01

A novel approach to multichannel signal enhancement is presented that exploits data from a remote wireless microphone (RWM). This RWM is placed near an interfering source and transmits only autocorrelation data of its observations to a host, i.e., not the entire signal. The host has access to the

Classification of Multichannel ECG Signals Using a Cross-Distance Analysis

National Research Council Canada - National Science Library

Shahram, Morteza

2001-01-01

This paper presents a multi-stage algorithm for multi-channel ECG beat classification into normal and abnormal categories using a sequential beat clustering and a cross- distance analysis algorithm...

Multi-channel electronically scanned cryogenic pressure sensor

Science.gov (United States)

Chapman, John J. (Inventor); Hopson, Purnell, Jr. (Inventor); Kruse, Nancy M. H. (Inventor)

1995-01-01

A miniature, multi-channel, electronically scanned pressure measuring device uses electrostatically bonded silicon dies in a multielement array. These dies are bonded at specific sites on a glass, prepatterned substrate. Thermal data is multiplexed and recorded on each individual pressure measuring diaphragm. The device functions in a cryogenic environment without the need of heaters to keep the sensor at constant temperatures.

AN ADAPTIVE MULTI-CHANNEL SPECTROELLIPSOMETER FOR ECOLOGICAL MONITORING

Directory of Open Access Journals (Sweden)

F. A. Mkrtchyan

2012-09-01

Full Text Available The creation of multichannel polarization optical instrumentation and use of spectroellipsometric technology are very important for the real-time ecological control of aquatic environment. Spectroellipsometric devices give us high precision of measurements. This report is aimed to describe: •A technology of combined use of spectroellipsometry and algorithms of identification and recognition that allowed the creation of a standard integral complex of instrumental, algorithmic, modular and software tools for the collection and processing of data on the aquatic environment quality with forecasting and decision - making functions. •A compact measuring - information multichannel spectroellipsometric system (device for monitoring the quality of aquatic environment, that is based on the combined use of spectroellipsometry and training, classification, and identification algorithms. This spectroellipsometric system will differ from modern foreign analogues by the use of a new and very promising method of ellipsometric measurements, an original element base of polarization optics and a complex mathematical approach to estimating the quality of a water object subjected to anthropogenic influence.Unlike foreign analogues, the system has no rotating polarization elements. This allows one to increase the signal-to-noise ratio and the long-term stability of measurements, to simplify and reduce the price of multichannel spectroellipsometers. The system will be trainable to the recognition of the pollutants of aquatic environment. A spectroellipsometer in laboratories of V.A. Kotelnikov's Institute of Radioengineering and Electronics, Russian Academy of Sciences is designed for in-situ real time measurements of spectra of ellipsometric parameters Psi and Delta with consequent changeover to spectra of transmitted and reflected signal from water media in frames of used physical model of water environment.

Simulation study on vertically distributed multi-channel tangential interferometry for KSTAR

International Nuclear Information System (INIS)

Nam, Y U; Juhn, J W

2012-01-01

Interferometry is powerful and reliable diagnostics which measures line-integrated electron density. Since this technique only measures an averaged value over whole probing line, a multi-channel scheme is used for an analysis for spatial distribution and variation of electron density. Typical setups of the multi-channel measurement are schemes of radially distributed vertical lines, vertically distributed horizontal lines and horizontally distributed tangential lines. In Korea Superconducting Tokamak Advanced Research, a vertically distributed multi-channel tangential interferometry is planned instead of above typical schemes due to limitation of complex in-vessel geometry and narrow diagnostics port through cryostat. Total 5-channels will be vertically placed as symmetric with the mid-plain. One of the characteristic features of the vertically distributed channels is that each channel is viewing different poloidal angle, while the horizontally distributed channels are viewing different toroidal angle. This scheme also can be used on an investigation of the up-down asymmetry and the vertical oscillation of plasma. Simulation has been performed and the result will be discussed to verify the possibility and the estimated effectiveness of the scheme on this paper.

A high-speed interface for multi-channel analyzer

International Nuclear Information System (INIS)

Shen Ji; Zheng Zhong; Qiao Chong; Chen Ziyu; Ye Yunxiu; Ye Zhenyu

2003-01-01

This paper presents a high-speed computer interface for multi-channel analyzer based on DMA technique. Its essential principle and operating procedure are introduced. By the detecting of γ spectrum of 137 Cs with the interface, it's proved that the interface can meet the requirements of high-speed data acquisition

Compact multichannel MEMS based spectrometer for FBG sensing

DEFF Research Database (Denmark)

Ganziy, Denis; Rose, Bjarke; Bang, Ole

2017-01-01

We propose a novel type of compact multichannel MEMS based spectrometer, where we replace the linear detector with a Digital Micromirror Device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used in the 1550 nm range, which leads to cost reduction...

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.

Multiple scattering theory for non-local and multichannel potentials

Czech Academy of Sciences Publication Activity Database

Natoli, C.R.; Krüger, P.; Hatada, K.; Hayakawa, K.; Sébilleau, D.; Šipr, Ondřej

2012-01-01

Roč. 24, č. 36 (2012), s. 1-20 ISSN 0953-8984 Institutional research plan: CEZ:AV0Z10100521 Keywords : multichannel scattering * correlation s * density matrix Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.355, year: 2012

Efficient frequency conversion through absorptive bands of the nonlinear crystal

OpenAIRE

Porat, Gil; Arie, Ady

2012-01-01

Two simultaneous three wave mixing processes are analyzed, where an input frequency is converted to an output frequency via an intermediate stage. By employing simultaneous phase-matching and an adiabatic modulation of the nonlinear coupling strengths, the intermediate frequency is kept dark throughout the interaction, while obtaining high conversion efficiency. This feat is accomplished in a manner analogous to population transfer in atomic stimulated Raman adiabatic passage (STIRAP). Applic...

Multichannel optical mapping: investigation of depth information

Science.gov (United States)

Sase, Ichiro; Eda, Hideo; Seiyama, Akitoshi; Tanabe, Hiroki C.; Takatsuki, Akira; Yanagida, Toshio

2001-06-01

Near infrared (NIR) light has become a powerful tool for non-invasive imaging of human brain activity. Many systems have been developed to capture the changes in regional brain blood flow and hemoglobin oxygenation, which occur in the human cortex in response to neural activity. We have developed a multi-channel reflectance imaging system, which can be used as a `mapping device' and also as a `multi-channel spectrophotometer'. In the present study, we visualized changes in the hemodynamics of the human occipital region in multiple ways. (1) Stimulating left and right primary visual cortex independently by showing sector shaped checkerboards sequentially over the contralateral visual field, resulted in corresponding changes in the hemodynamics observed by `mapping' measurement. (2) Simultaneous measurement of functional-MRI and NIR (changes in total hemoglobin) during visual stimulation showed good spatial and temporal correlation with each other. (3) Placing multiple channels densely over the occipital region demonstrated spatial patterns more precisely, and depth information was also acquired by placing each pair of illumination and detection fibers at various distances. These results indicate that optical method can provide data for 3D analysis of human brain functions.

Multichannel analysis of He*(21S)+Ne elastic and inelastic scattering in crossed atomic beams

International Nuclear Information System (INIS)

Martin, D.W.; Fukuyama, T.; Siska, P.E.

1990-01-01

State-to-state elastic and inelastic angular distribution and time-of-flight measurements are reported for the scattering of He*(2 1 S) by Ne in crossed supersonic atom beams at four collision energies in the range 0.6--2.8 kcal/mol. The inelastic collision products He+Ne*(nl), where nl=3d', 4p, 4p', 5s, 5s', and 4d, are scattered predominantly forward with respect to the direction of incidence, except for endothermic states near threshold. The data are analyzed with a numerically exact multichannel curve-crossing model that yields good agreement with experimental cross section branching fractions and total quenching and state-to-state rate constants as well as the angular measurements. The model suggests the importance of intermediate ''chaperone'' states, in which the excited electron is temporarily trapped in a d or f Rydberg Ne orbital, in channeling flux into the 4s' and 5s' upper laser states of Ne by energy transfer from He*(2s 1,3 S)

Behind the web store: the organisational and spatial evolution of multichannel retailing in Toronto

OpenAIRE

Andrew Currah

2002-01-01

In this paper I address two issues of general relevance to contemporary debates in economic geography: first, the organisational and spatial implications of new information technologies for the economic landscape; and, second, the enduring role of place to digital capitalism. Specifically, I examine the organisational evolution of multichannel retailing in Toronto from a geographical perspective. Bricks-and-mortar retailers are increasingly pursuing a multichannel strategy by operating an Int...

Radio frequency picosecond phototube

International Nuclear Information System (INIS)

Margaryan, A.; Carlini, R.; Ent, R.; Grigoryan, N.; Gyunashyan, K.; Hashimoto, O.; Hovater, K.; Ispiryan, M.; Knyazyan, S.; Kross, B.; Majewski, S.; Marikyan, G.; Mkrtchyan, M.; Parlakyan, L.; Popov, V.; Tang, L.; Vardanyan, H.; Yan, C.; Zhamkochyan, S.; Zorn, C.

2006-01-01

We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation

Radio frequency picosecond phototube

Energy Technology Data Exchange (ETDEWEB)

Margaryan, A. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia)]. E-mail: mat@mail.yerphi.am; Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ent, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Grigoryan, N. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Gyunashyan, K. [Yerevan State University of Architecture and Construction, Yerevan (Armenia); Hashimoto, O. [Tohoku University, Sendai 98-77 (Japan); Hovater, K. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ispiryan, M. [University of Houston, 4800 Calhoun Rd, Houston TX 77204 (United States); Knyazyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Kross, B. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Majewski, S. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Marikyan, G. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Mkrtchyan, M. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Parlakyan, L. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Tang, L. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Vardanyan, H. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Zhamkochyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States)

2006-10-15

We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation.

Retail business model transformation in multichannel environment

OpenAIRE

Chapagain, B. (Bimala)

2015-01-01

Abstract With the advent of internet and e-commerce, the way of carrying out business and transactions has changed to a great extent. Consumers are continuously changing the way they do shopping and this has forced retail business to transform their traditional brick and mortar into adopting multi-channel business models. Retailing is one of the most dynamic and competitive areas of business organization. Effective marketin...

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

On iteration-separable method on the multichannel scattering theory

International Nuclear Information System (INIS)

Zubarev, A.L.; Ivlieva, I.N.; Podkopaev, A.P.

1975-01-01

The iteration-separable method for solving the equations of the Lippman-Schwinger type is suggested. Exponential convergency of the method of proven. Numerical convergency is clarified on the e + H scattering. Application of the method to the theory of multichannel scattering is formulated

A multi-channel coronal spectrophotometer.

Science.gov (United States)

Landman, D. A.; Orrall, F. Q.; Zane, R.

1973-01-01

We describe a new multi-channel coronal spectrophotometer system, presently being installed at Mees Solar Observatory, Mount Haleakala, Maui. The apparatus is designed to record and interpret intensities from many sections of the visible and near-visible spectral regions simultaneously, with relatively high spatial and temporal resolution. The detector, a thermoelectrically cooled silicon vidicon camera tube, has its central target area divided into a rectangular array of about 100,000 pixels and is read out in a slow-scan (about 2 sec/frame) mode. Instrument functioning is entirely under PDP 11/45 computer control, and interfacing is via the CAMAC system.

OAST Space Theme Workshop. Volume 2: Theme summary. 3: Search for extraterrestrial intelligence (no. 9). A: Theme statement. B. 26 April 1976 presentation. C. Summary. D. Newer initiatives (form 4). E. Initiative actions (form 5)

Science.gov (United States)

1976-01-01

Preliminary (1977-1983), intermediate (1982-1988), and long term (1989+) phases of the search for extraterrestrial intelligence (SETI) program are examined as well as the benefits to be derived in radioastronomy and the problems to be surmounted in radio frequency interference. The priorities, intrinsic value, criteria, and strategy for the search are discussed for both terrestrial and lunar-based CYCLOPS and for a space SETI system located at lunar liberation point L4. New initiatives related to antenna independent technology, multichannel analyzers, and radio frequency interference shielding are listed. Projected SETI program costs are included.

Fibercore AstroGain fiber: multichannel erbium doped fibers for optical space communications

Science.gov (United States)

Hill, Mark; Gray, Rebecca; Hankey, Judith; Gillooly, Andy

2014-03-01

Fibercore have developed AstroGainTM fiber optimized for multichannel amplifiers used in optical satellite communications and control. The fiber has been designed to take full advantage of the photo-annealing effect that results from pumping in the 980nm region. The proprietary trivalent structure of the core matrix allows optimum recovery following radiation damage to the fiber, whilst also providing a market leading Erbium Doped Fiber Amplifier (EDFA) efficiency. Direct measurements have been taken of amplifier efficiency in a multichannel assembly, which show an effective photo-annealing recovery of up to 100% of the radiation induced attenuation through excitation of point defects.

Multi-Channel RF System for MRI-Guided Transurethral Ultrasound Thermal Therapy

Science.gov (United States)

Yak, Nicolas; Asselin, Matthew; Chopra, Rajiv; Bronskill, Michael

2009-04-01

MRI-guided transurethral ultrasound thermal therapy is an approach to treating localized prostate cancer which targets precise deposition of thermal energy within a confined region of the gland. This treatment requires a system incorporating a heating applicator with multiple planar ultrasound transducers and associated RF electronics to control individual elements independently in order to achieve accurate 3D treatment. We report the design, construction, and characterization of a prototype multi-channel system capable of controlling 16 independent RF signals for a 16-element heating applicator. The main components are a control computer, microcontroller, and a 16-channel signal generator with 16 amplifiers, each incorporating a low-pass filter and transmitted/reflected power detection circuit. Each channel can deliver from 0.5 to 10 W of electrical power and good linearity from 3 to 12 MHz. Harmonic RF signals near the Larmor frequency of a 1.5 T MRI were measured to be below -30 dBm and heating experiments within the 1.5 T MR system showed no significant decrease in SNR of the temperature images. The frequency and power for all 16 channels could be changed in less than 250 ms, which was sufficiently rapid for proper performance of the control algorithms. A common backplane design was chosen which enabled an inexpensive, modular approach for each channel resulting in an overall system with minimal footprint.

Phase sensitive multichannel OCT

International Nuclear Information System (INIS)

Trasischker, W.

2015-01-01

The main aim of this thesis was to develop and improve phase sensitive, multichannel methods for optical coherence tomography (OCT) using light in the 840 nm and 1040 nm regime. Conventional OCT provides purely structural information by illuminating the sample by one beam and recording the backscattered signal with one detection channel. Combination of this approach with a raster scan enables the acquisition of 2D and 3D structural information with a resolution in the micrometer regime. However, sometimes additional image contrast or information is desired. Amongst other approaches, this can be provided by a phase sensitive analysis of the interference pattern. Combining phase sensitivity with the illumination of the sample by more than one beam and/or by recording the data using more than one data acquisition channel allows for even more enhanced imaging. While phase sensitive OCT gives access to additional contrast and information, multichannel OCT can provide higher imaging speed, scan eld size and exible dierential measurements. Amongst the dierential, phase sensitive approaches, Doppler OCT (DOCT) and polarization sensitive OCT (PS-OCT) are two of the most promising OCT modalities. While the former targets information on the movement of backscattering particles, the latter measures alterations of the polarization state of the light induced by the sample. Both techniques provide additional image contrast and are, due to the non-invasive and fast character of OCT, well suited for in vivo imaging of the human eye. In the course of this thesis, two dierent multichannel, phase sensitive OCT systems will be presented. First, a D-OCT system with three dierent sampling beams is described. With a central wavelength of 840 nm these three beams are emitted by three individual laser sources. This eectively eliminates any cross talk and provides the full depth range for each channel. Furthermore, by illuminating the sample from three dierent directions, the absolute

A fully algebraic solution for multichannel scattering of neutrons from nuclei

International Nuclear Information System (INIS)

Amos, K.

2001-01-01

In this report I give the prescription by which an algebraic solution can be found for multichannel scattering of neutrons from nuclei. The theory, developed by the Padova group, is built upon the work of Rawitscher and Delic. The approach is predicated upon finite rank representations of realistic interaction potentials and the properties of scattering matrices for separable Schrodinger interactions. The Padova approach starts with a solvable auxiliary Sturmian function (Weinberg state) problem from which a first generation set of Sturmians are defined. That basis set is formed by choosing a solvable problem at a fixed negative energy, and thereby those Sturmians can be specified in closed analytic form. Second generation Sturmians built upon the interaction potential matrices for a multichannel scattering problem of interest then can be found as linear combinations of the first generation set. The expansion coefficients result from a matrix diagonalization process. The scheme enables an expansion (usually truncated to finite rank for convenience) of the interaction potential in terms of those second generation Sturmians and in the form of a sum of separable interactions. The analytic properties of the scattering matrix from a separable Schroedinger potential gives the means by which a full algebraic solution of the multichannel scattering problem can be realized. (author)

A multi-channel high-resolution time recorder system

International Nuclear Information System (INIS)

Zhang Lingyun; Yang Xiaojun; Song Kezhu; Wang Yanfang

2004-01-01

This paper introduces a multi-channel and high-speed time recorder system, which was originally designed to work in the experiments of quantum cryptography research. The novelty of the system is that all the hardware logic is performed by only one FPGA. The system can achieve several desirable features, such as simplicity, high resolution and high processing speed. (authors)

Effect of flow rate distribution at the inlet on hydrodynamic mixing in narrow rectangular multi-channel

International Nuclear Information System (INIS)

Xu Jianjun; Chen Bingde; Wang Xiaojun

2008-01-01

Flow and heat transfer in the narrow rectangular multi-channel is widely en- countered in the engineering application, hydrodynamic mixing in the narrow rectangular multi-channel is one of the important concerns. With the help of the Computational Fluid Dynamics code CFX, the effect of flow rate distribution of the main channel at the inlet on hydrodynamic mixing in the narrow rectangular multi-channel is numerical simulated. The results show that the flow rate distributions at the inlet have a great effect on hydrodynamics mixing in multi-channel, the flow rate in the main channel doesn't change with increasing the axial mixing section when the average flow rate at the inlet is set. Hydrodynamic mixing will arise in the mixing section when the different ratio of the flow rate distribution at the inlet is set, and hydrodynamic mixing increases with the difference of the flow rate distribution at the inlet increase. The trend of the flow rate distribution of the main channel is consistent during the whole axial mixing section, and hydrodynamic mixing in former 4 mixing section is obvious. (authors)

The MHD intermediate shock interaction with an intermediate wave: Are intermediate shocks physical?

International Nuclear Information System (INIS)

Wu, C.C.

1988-01-01

Contrary to the usual belief that MHD intermediate shocks are extraneous, the authors have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear steepening from a continuous wave. In this paper, he clarifies the differences between the conventional view and the results by studying the interaction of an MHD intermediate shock with an intermediate wave. The study reaffirms his results. In addition, the study shows that there exists a larger class of shocklike solutions in the time-dependent dissiaptive MHD equations than are given by the MHD Rankine-Hugoniot relations. it also suggests a mechanism for forming rotational discontinuities through the interaction of an intermediate shock with an intermediate wave. The results are of importance not only to the MHD shock theory but also to studies such as magnetic field reconnection models

Robust, highly customizable, and economical multi-channel electrode for chronic multi-unit recording in behaving animals.

Science.gov (United States)

Tateyama, Yukina; Oyama, Kei; Shiraishi, Masaru; Iijima, Toshio; Tsutsui, Ken-Ichiro

2017-12-01

Multi-unit recording has been one of the most widely used techniques to investigate the correlation between multiple neuronal activities and behavior. However, a common problem of currently used multi-channel electrodes is their physical weakness. In this study, we developed a novel multi-channel electrode with sufficient physical strength to penetrate a thickened dura mater. This electrode consists of low-cost materials and is easily fabricated, and it enables recording without removing dura mater, thereby reducing the risk of inflammation, infection, or brain herniation. The low-cost multi-channel electrode developed in this study would be a useful tool for chronic recording in behaving animals. Copyright © 2017. Published by Elsevier B.V.

Multi-channel spintronic transistor design based on magnetoelectric barriers and spin-orbital effects

International Nuclear Information System (INIS)

Fujita, T; Jalil, M B A; Tan, S G

2008-01-01

We present a spin transistor design based on spin-orbital interactions in a two-dimensional electron gas, with magnetic barriers induced by a patterned ferromagnetic gate. The proposed device overcomes certain shortcomings of previous spin transistor designs such as long device length and degradation of conductance modulation for multi-channel transport. The robustness of our device for multi-channel transport is unique in spin transistor designs based on spin-orbit coupling. The device is more practical in fabrication and experimental respects compared to previously conceived single-mode spin transistors

Multi-channel temperature measurement system for automotive battery stack

Science.gov (United States)

Lewczuk, Radoslaw; Wojtkowski, Wojciech

2017-08-01

A multi-channel temperature measurement system for monitoring of automotive battery stack is presented in the paper. The presented system is a complete battery temperature measuring system for hybrid / electric vehicles that incorporates multi-channel temperature measurements with digital temperature sensors communicating through 1-Wire buses, individual 1-Wire bus for each sensor for parallel computing (parallel measurements instead of sequential), FPGA device which collects data from sensors and translates it for CAN bus frames. CAN bus is incorporated for communication with car Battery Management System and uses additional CAN bus controller which communicates with FPGA device through SPI bus. The described system can parallel measure up to 12 temperatures but can be easily extended in the future in case of additional needs. The structure of the system as well as particular devices are described in the paper. Selected results of experimental investigations which show proper operation of the system are presented as well.

Development of a Multi-Channel Piezoelectric Acoustic Sensor Based on an Artificial Basilar Membrane

Directory of Open Access Journals (Sweden)

Youngdo Jung

2013-12-01

Full Text Available In this research, we have developed a multi-channel piezoelectric acoustic sensor (McPAS that mimics the function of the natural basilar membrane capable of separating incoming acoustic signals mechanically by their frequency and generating corresponding electrical signals. The McPAS operates without an external energy source and signal processing unit with a vibrating piezoelectric thin film membrane. The shape of the vibrating membrane was chosen to be trapezoidal such that different locations of membrane have different local resonance frequencies. The length of the membrane is 28 mm and the width of the membrane varies from 1 mm to 8 mm. Multiphysics finite element analysis (FEA was carried out to predict and design the mechanical behaviors and piezoelectric response of the McPAS model. The designed McPAS was fabricated with a MEMS fabrication process based on the simulated results. The fabricated device was tested with a mouth simulator to measure its mechanical and piezoelectrical frequency response with a laser Doppler vibrometer and acoustic signal analyzer. The experimental results show that the as fabricated McPAS can successfully separate incoming acoustic signals within the 2.5 kHz–13.5 kHz range and the maximum electrical signal output upon acoustic signal input of 94 dBSPL was 6.33 mVpp. The performance of the fabricated McPAS coincided well with the designed parameters.

Very Fast Algorithms and Detection Performance of Multi-Channel and 2-D Parametric Adaptive Matched Filters for Airborne Radar

National Research Council Canada - National Science Library

Marple, Jr., S. L; Corbell, Phillip M; Rangaswamy, Muralidhar

2007-01-01

...) detection statistics under exactly known covariance (the clairvoyant case). Improved versions of the two original multichannel PAMF algorithms, one new multichannel PAMF algorithm, and a new two-dimensional (2D) PAMF algorithm...

Feasibility study of a real-time operating system for a multichannel MPEG-4 encoder

Science.gov (United States)

Lehtoranta, Olli; Hamalainen, Timo D.

2005-03-01

Feasibility of DSP/BIOS real-time operating system for a multi-channel MPEG-4 encoder is studied. Performances of two MPEG-4 encoder implementations with and without the operating system are compared in terms of encoding frame rate and memory requirements. The effects of task switching frequency and number of parallel video channels to the encoding frame rate are measured. The research is carried out on a 200 MHz TMS320C6201 fixed point DSP using QCIF (176x144 pixels) video format. Compared to a traditional DSP implementation without an operating system, inclusion of DSP/BIOS reduces total system throughput only by 1 QCIF frames/s. The operating system has 6 KB data memory overhead and program memory requirement of 15.7 KB. Hence, the overhead is considered low enough for resource critical mobile video applications.

On the oscillation of ultrasound absorption in the intermediate-state superconductors

International Nuclear Information System (INIS)

Shepelev, A.G.; Filimonov, G.D.

1981-01-01

The correlation between theory and experiment for the phenomenon of oscillations of ultrasound absorption in the pure superconductor intermediate state is analyzed. High-frequency sound (lambdasub(s) [ru

ABORt: Acknowledgement-Based Opportunistic Routing Protocol for High Data Rate Multichannel WSNs

Directory of Open Access Journals (Sweden)

Hamadoun Tall

2017-10-01

Full Text Available The ease of deployment and the auto-configuration capabilities of Wireless Sensor Networks (WSNs make them very attractive in different domains like environmental, home automation or heath care applications. The use of multichannel communications in WSNs helps to improve the overall performance of the network. However, in heavy traffic scenarios, routing protocols should be adapted to allow load balancing and to avoid losing data packets due to congestion and queue overflow. In this paper, we present an Acknowledgement-Based Opportunistic Routing (ABORt protocol designed for high data rate multichannel WSNs. It is a low overhead protocol that does not rely on synchronization for control traffic exchange during the operational phase of the network. ABORt is an opportunistic protocol that relies on link layer acknowledgements to disseminate routing metrics, which helps to reduce overhead. The performance of ABORt is evaluated using the Cooja simulator and the obtained results show that ABORt has a high packet delivery ratio with reduced packet end-to-end delay compared to two single channel routing protocols and two multichannel routing protocols that use number of hops and expected transmission count as routing metrics.

Evaluation of biological effects of intermediate frequency magnetic field on differentiation of embryonic stem cell.

Science.gov (United States)

Yoshie, Sachiko; Ogasawara, Yuki; Ikehata, Masateru; Ishii, Kazuyuki; Suzuki, Yukihisa; Wada, Keiji; Wake, Kanako; Nakasono, Satoshi; Taki, Masao; Ohkubo, Chiyoji

2016-01-01

The embryotoxic effect of intermediate frequency (IF) magnetic field (MF) was evaluated using murine embryonic stem (ES) cells and fibroblast cells based on the embryonic stem cell test (EST). The cells were exposed to 21 kHz IF-MF up to magnetic flux density of 3.9 mT during the cell proliferation process (7 days) or the cell differentiation process (10 days) during which an embryonic body differentiated into myocardial cells. As a result, there was no significant difference in the cell proliferation between sham- and IF-MF-exposed cells for both ES and fibroblast cells. Similarly, the ratio of the number of ES-derived cell aggregates differentiated to myocardial cells to total number of cell aggregates was not changed by IF-MF exposure. In addition, the expressions of a cardiomyocytes-specific gene, Myl2 , and an early developmental gene, Hba-x , in the exposed cell aggregate were not altered. Since the magnetic flux density adopted in this study is much higher than that generated by an inverter of the electrical railway, an induction heating (IH) cooktop, etc . in our daily lives, these results suggested that IF-MF in which the public is exposed to in general living environment would not have embryotoxic effect.

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.

Multi-channel coherent perfect absorbers

KAUST Repository

Bai, Ping; Wu, Ying; Lai, Yun

2016-01-01

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.

Numerical investigation of multichannel laser beam phase locking in turbulent atmosphere

Energy Technology Data Exchange (ETDEWEB)

Volkov, V A; Volkov, M V; Garanin, S G; Starikov, F A [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

2015-12-31

The efficiency of coherent multichannel beam combining under focusing through a turbulent medium on a target in the cases of phase conjugation and target irradiation in the feedback loop is investigated numerically in various approximations. The conditions of efficient focusing of multichannel radiation on the target are found. It is shown that the coherent beam combining with target irradiation in the feedback loop, which does not require a reference beam and wavefront measurements, is as good as the phase conjugation approach in the efficiency of focusing. It is found that the main effect of focusing is provided by properly chosen phase shifts in the channels, whereas taking into account local wavefront tip tilts weakly affects the result. (control of laser radiation parameters)

A study on the heating and diagnostic of a tokamak plasma by electromagnetic waves of the electron cyclotron range of frequencies

International Nuclear Information System (INIS)

Hoshino, Katsumichi

1989-09-01

A study on the heating and diagnosis of tokamak plasma by electromagnetic waves of electron cyclotron range of frequency is summarized. The main results obtained are as follows. On the engineering and technology, the technology of injecting high frequency, large power millimeter waves into tokamak plasma was established by carrying out the design, manufacture and test of a 60 GHz, 400 kW high frequency heating system, and the design, manufacture and test of a heterodyne type electron cyclotron radiation multi-channel mealsuring system were carried out, and the technology of measuring the radiation from tokamak plasma with the time resolution of 10 μs in multi-channel was established. On nuclear fusion reactor core engineering and plasma physics, the high efficiency electron heating of tokamak plasma by the incidence of fundamental irregular and regular waves at electron cyclotron frequency was verified. The discovery and analysis of the heating by electrostatic waves arising due to mode transformation from electromagnetic waves in upper hybrid resonance layer were carried out. By the incidence of second harmonic waves, the high efficiency electron heating of tokamak plasma was verified, and the heating characteristics were clarified. And others. (K.I.) 179 refs

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.

Simple multifunction discriminator for multichannel triggers

International Nuclear Information System (INIS)

Maier, M.R.

1982-10-01

A simple version of a multifunction timing discriminator using only two integrated circuits is presented. It can be configured as a leading edge, a constant fraction, a zero cross or a dual threshold timing discriminator. Since so few parts are used, it is well suited for building multichannel timing discriminators. Two versions of this circuit are described: a quadruple multifunction discriminator and an octal constant fraction trigger. The different compromises made in these units are discussed. Results for walk and jitter obtained with these are presented and possible improvements are disussed

Feasibility study of applying a multi-channel analysis model to on-line core monitoring system

International Nuclear Information System (INIS)

In, W. K.; Yoo, Y. J.; Hwang, D. H.; Jun, T. H.

1998-01-01

A feasibility study was performed to evaluate the effect of implementing a multi-channel analysis model in on-line core monitoring system. A simplified thermal-hydraulic model has been used in the on-line core monitoring system of digital PWR. The design procedure, core thermal margin and computation time were investigated in case of replacing the simplified model with the multi-channel analysis model. For the given ranges of limiting conditions for operation in Yonggwang Unit 3 Cycle 1, the minimum DNBR of the simplified thermal-hydraulic code CETOP-D was compared to that of the multi-channel analysis code MATRA. A CETOP-D tuning is additionally required to ensure the accurate and conservative DNBR calculation but the MATRA tuning is not necessary. MATRA appeared to increase the DNBR overpower margin from 2.5% to 6% over the CETOP-D margin. MATRA took approximately 1 second to compute DNBR on the HP9000 workstation system, which is longer than the DNBR computation time of CETOP-D. It is, however, fast enough to perform the on-line monitoring of DNBR. It can be therefore concluded that the application of the multi-channel analysis model MATRA in the on-line core monitoring system is feasible

Field microcomputerized multichannel γ ray spectrometer based on notebook computer

International Nuclear Information System (INIS)

Jia Wenyi; Wei Biao; Zhou Rongsheng; Li Guodong; Tang Hong

1996-01-01

Currently, field γ ray spectrometry can not rapidly measure γ ray full spectrum, so a field microcomputerized multichannel γ ray spectrometer based on notebook computer is described, and the γ ray full spectrum can be rapidly measured in the field

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

Salt Intrusion, Tides and Mixing in Multi-channel Estuaries

NARCIS (Netherlands)

Nguyen, A.D.

2008-01-01

Multi-channel estuaries, such as the Mekong Delta in Vietnam and the Scheldt in the Netherlands, have characteristics of both the river and the sea, forming a unique environment influenced by tidal movements of the sea and freshwater flow of the river. This study addresses a number of knowledge gaps

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.

A Novel Spectrally Efficient Asynchronous Multi-Channel MAC Using a Half-Duplex Transceiver for Wireless Networks

Directory of Open Access Journals (Sweden)

Abdullah Devendiran

2018-01-01

Full Text Available Multi-channel medium access control (MAC protocols maximize network performance by enabling concurrent wireless transmissions over non-interfering channels. Despite physical layer advancements, the underlying IEEE 802.11 MAC standard cannot fully exploit features and support high-performance applications. In this work, we propose the novel spectrally efficient asynchronous multi-channel MAC (SA-MMAC protocol for wireless networks using a single half-duplex transceiver. A full-duplex mode of operation on data channels reduces the signaling overhead and boosts the spectrum efficiency. A revamped contention mechanism of IEEE 802.11 addresses the multi-channel hidden terminal problem, and a jamming signal from the receiver addresses the collisions in control signals. Furthermore, the control channel is used for data transmissions to increase the bandwidth utilization but under a restricted half-duplex mode to avoid causing a bottleneck situation. The simulator is tested for correctness. The results suggest that the protocol can work well on 3, 4, or 12 concurrent channels with high node density, providing about 12.5 times more throughput than IEEE 802.11 and 18% to 95% more throughput than its multi-channel variants under saturated traffic conditions.

A multichannel pulse acquisition system for reactor dosimetry data

International Nuclear Information System (INIS)

Talpalariu, C.; Talpalariu, J.; Matei, C.

1999-01-01

Simultaneous measurements of many dosimetry parameters require a complex instrumentation equipment, computers and interfaces. For a very large frequency range (10 -3 to 10 6 Hz) scale and mode selection (period or frequency), a big problem in multichannel pulse measurement is that of dead time, precision and response time. The dead time for normal scale selection and for data reading or writing for every channel can be as long as the active measuring time and response time for very large frequency variation can be very long, too. To solve this problem we have designed for a simultaneous 40 channel measurement, a pulse counter sampling system and an expert operating system. Based on a 486 PC and a 10 channel Timer/Counter Card, the hardware performance of the system was improved by an expert program for early rate change detection and rate prediction. The rate value was determined from optimizing between current value, medium and long time values and shorter response time for transient signals. Significant features and advantages of the system are the following: a marked reduction in panel complexity, as many of the indicators and controls can be replaced by an interactive CRT keyboard, a reduction in the instrumentation complexity, failure detection and diagnosis, system performance monitoring, intelligent alarm handling. The system was designed from high accuracy measurements on 40 simultaneous channels fed from field radiation detectors like ionizing chambers, fission chambers and photomultipliers.. The operating system is using an auto-organizing data memory for both computing the current value and for long-term management of data, so that only the status and significant values of the input are recorded. Consequently, the algorithms of decision, search and data processing are simplified and limited to the necessary memory, although enough memory is preserved for accurate representation of the dosimetry curves. The utilization of an inferential algorithm for the

New-fashioned Multi-channel Analyzer Based on Bipartition Method

International Nuclear Information System (INIS)

Liu Mingjian; Zhang Yan; Yan Xuekun; Chen Ying

2009-01-01

A new-fashioned digital-analog converter (DAC) which can find the pulse-signal amplitude through dichotomy is devised. With this new DAC method, a 256-channel multi-channel pulse amplitude analyzer (MCA) is designed successfully, and its hardware and software are introduced in detail. This provides a new method for designing MCA. (authors)

Integrated multi-channel vehicle-vehicle and vehicle-roadside communications for ITS

Science.gov (United States)

2008-12-01

This research describes a medium access control (MAC) protocol to Enable multi-channel operation for dedicated short-range communication (DSRC). In particular, we focus on the challenge of supporting potentially high-bandwidth commercial or infotainm...

Skyrmion-based multi-channel racetrack

Science.gov (United States)

Song, Chengkun; Jin, Chendong; Wang, Jinshuai; Xia, Haiyan; Wang, Jianbo; Liu, Qingfang

2017-11-01

Magnetic skyrmions are promising for the application of racetrack memories, logic gates, and other nano-devices, owing to their topologically protected stability, small size, and low driving current. In this work, we propose a skyrmion-based multi-channel racetrack memory where the skyrmion moves in the selected channel by applying voltage-controlled magnetic anisotropy gates. It is demonstrated numerically that a current-dependent skyrmion Hall effect can be restrained by the additional potential of the voltage-controlled region, and the skyrmion velocity and moving channel in the racetrack can be operated by tuning the voltage-controlled magnetic anisotropy, gate position, and current density. Our results offer a potential application of racetrack memory based on skyrmions.

Development of multi-channel gated integrator and PXI-DAQ system for nuclear detector arrays

International Nuclear Information System (INIS)

Kong Jie; Su Hong; Chen Zhiqiang; Dong Chengfu; Qian Yi; Gao Shanshan; Zhou Chaoyang; Lu Wan; Ye Ruiping; Ma Junbing

2010-01-01

A multi-channel gated integrator and PXI based data acquisition system have been developed for nuclear detector arrays with hundreds of detector units. The multi-channel gated integrator can be controlled by a programmable GI controller. The PXI-DAQ system consists of NI PXI-1033 chassis with several PXI-DAQ cards. The system software has a user-friendly GUI which is written in C language using LabWindows/CVI under Windows XP operating system. The performance of the PXI-DAQ system is very reliable and capable of handling event rate up to 40 kHz.

Multichannel Signals Reconstruction Based on Tunable Q-Factor Wavelet Transform-Morphological Component Analysis and Sparse Bayesian Iteration for Rotating Machines

Directory of Open Access Journals (Sweden)

Qing Li

2018-04-01

Full Text Available High-speed remote transmission and large-capacity data storage are difficult issues in signals acquisition of rotating machines condition monitoring. To address these concerns, a novel multichannel signals reconstruction approach based on tunable Q-factor wavelet transform-morphological component analysis (TQWT-MCA and sparse Bayesian iteration algorithm combined with step-impulse dictionary is proposed under the frame of compressed sensing (CS. To begin with, to prevent the periodical impulses loss and effectively separate periodical impulses from the external noise and additive interference components, the TQWT-MCA method is introduced to divide the raw vibration signal into low-resonance component (LRC, i.e., periodical impulses and high-resonance component (HRC, thus, the periodical impulses are preserved effectively. Then, according to the amplitude range of generated LRC, the step-impulse dictionary atom is designed to match the physical structure of periodical impulses. Furthermore, the periodical impulses and HRC are reconstructed by the sparse Bayesian iteration combined with step-impulse dictionary, respectively, finally, the final reconstructed raw signals are obtained by adding the LRC and HRC, meanwhile, the fidelity of the final reconstructed signals is tested by the envelop spectrum and error analysis, respectively. In this work, the proposed algorithm is applied to simulated signal and engineering multichannel signals of a gearbox with multiple faults. Experimental results demonstrate that the proposed approach significantly improves the reconstructive accuracy compared with the state-of-the-art methods such as non-convex Lq (q = 0.5 regularization, spatiotemporal sparse Bayesian learning (SSBL and L1-norm, etc. Additionally, the processing time, i.e., speed of storage and transmission has increased dramatically, more importantly, the fault characteristics of the gearbox with multiple faults are detected and saved, i.e., the

[Analysis of the Muscle Fatigue Based on Band Spectrum Entropy of Multi-channel Surface Electromyography].

Science.gov (United States)

Liu, Jian; Zou, Renling; Zhang, Dongheng; Xu, Xiulin; Hu, Xiufang

2016-06-01

Exercise-induced muscle fatigue is a phenomenon that the maximum voluntary contraction force or power output of muscle is temporarily reduced due to muscular movement.If the fatigue is not treated properly,it will bring about a severe injury to the human body.With multi-channel collection of lower limb surface electromyography signals,this article analyzes the muscle fatigue by adoption of band spectrum entropy method which combined electromyographic signal spectral analysis and nonlinear dynamics.The experimental result indicated that with the increase of muscle fatigue,muscle signal spectrum began to move to low frequency,the energy concentrated,the system complexity came down,and the band spectrum entropy which reflected the complexity was also reduced.By monitoring the entropy,we can measure the degree of muscle fatigue,and provide an indicator to judge fatigue degree for the sports training and clinical rehabilitation training.

Very low cost multichannel analyzer with some additional features

Energy Technology Data Exchange (ETDEWEB)

Tudyka, Konrad, E-mail: konrad.tudyka@polsl.pl [Centre of Excellence-Gliwice Absolute Dating Methods Centre, Institute of Physics, Silesian University of Technology (Poland); Bluszcz, Andrzej [Centre of Excellence-Gliwice Absolute Dating Methods Centre, Institute of Physics, Silesian University of Technology (Poland)

2011-12-11

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 {mu}s. 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{mu}s long.

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.

Coordinating Multi-Channel Pricing of Seasonal Goods

OpenAIRE

Preetam Basu

2012-01-01

Advancement in information technology has opened new avenues for traditional retailers to expand their operations. Pricing, which has been a critical issue, is more important than ever before as traditional retailers pursue multi-channel sales. In this paper the author studies the pricing problem of a retailer selling a seasonal product simultaneously in a ‘brick and mortar’ store as well as online. Optimal prices are derived and different product-market conditions are determined under wh...

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.

A low power Multi-Channel Analyzer

International Nuclear Information System (INIS)

Anderson, G.A.; Brackenbush, L.W.

1993-06-01

The instrumentation used in nuclear spectroscopy is generally large, is not portable, and requires a lot of power. Key components of these counting systems are the computer and the Multi-Channel Analyzer (MCA). To assist in performing measurements requiring portable systems, a small, very low power MCA has been developed at Pacific Northwest Laboratory (PNL). This MCA is interfaced with a Hewlett Packard palm top computer for portable applications. The MCA can also be connected to an IBM/PC for data storage and analysis. In addition, a real-time time display mode allows the user to view the spectra as they are collected

A Novel Architecture For Multichannel Analyzer

International Nuclear Information System (INIS)

Marcus, E.; Elhanani, I.; Nir, J.; Ellenbogen, M.; Kadmon, Y.; Tirosh, D.

1999-01-01

A novel digital approach to real-time, high-throughput, low-cost Multichannel Analyzer (MCA) for radiation spectroscopy is being presented. The MCA input is a shaped nuclear pulse sampled at a high rate, using an Analog-to-Digital Converter (ADC) chip. The digital samples are analyzed by a state-of-the-art Field Programmable Gate Away (FPGA). A customized algorithm is utilized to estimate the peak of the pulse, to reject pile-up and to eliminate processing dead time. The valid pulses estimated peaks are transferred to a micro controller system that creates the histogram and controls the Human Machine Interface (HMI)

Stingray-inspired robot with simply actuated intermediate motion

Science.gov (United States)

Neely, Lincoln; Gaiennie, Jack; Noble, Nick; Erickson, Jonathan C.

2016-04-01

Batoids, or rays, utilize unique forms of locomotion that may offer more efficient techniques of motorized propulsion in various marine environments. We present a novel biomimetic engineering design and assembly of a stingray-inspired robot swimmer. The robots locomotion mimics the Dasyatis americana, or southern stingray, whose distinction among rays is its intermediate motion, characterized by sweeping strokes that propagate between 1/2-1 wavelength of the fin profile in the posterior direction. Though oscillatory ( wavelengths) ray-based robots have been created, this project demonstrates new engineering possibilities in what is, to the best of our knowledge, the first intermediately propelled batoid-based robot. The robots fins were made of silicone rubber, cast in a 3-D printed mold, with wingspan of 42 cm (1/2 - 1/5 scale for males and females, respectively, scale of model organism). Two anteriorly placed servomotors per fin were used, all controlled by one wirelessly enabled Arduino microcontroller. Each servomotor oscillated a flexible rod with cylindrical joint, whose frequency, speed, and front-back phase delay were user-programmed over wireless connection. During free-swimming tests, the fin profile developed about 0.8 wavelength, qualifying for successful mimicry of its biological inspiration. The robot satisfactorily maintained straight-line motion, reaching average peak velocity of 9.4+/-1.0 cm/s (0.27-0.03 body lengths/second) at its optimum flapping frequency of 1.4 Hz. This is in the same order of magnitude of speed normalized to body length achieved by others in two recent batoid-based projects. In summary, our robot performed intermediate stingray locomotion with relatively fewer components, which reveals robust potential for innovation of the simple intermediate batoid-based robot swimmer.

Multichannel analyzer for the neutron time-of-flight spectrometer

International Nuclear Information System (INIS)

Vojter, A.P.; Slyisenko, V.Yi.; Doronyin, M.Yi.; Maznij, Yi.O.; Vasil'kevich, O.A.; Golyik, V.V.; Koval'ov, O.M.; Kopachov, V.Yi.; Savchuk, V.G.

2010-01-01

New multichannel time-of-flight spectrometer for the measurement of the energy and angular distributions of neutrons from the WWWR-M reactor is considered. This spectrometer has been developed for the replacement of the previous one to increase the number of channels and measurement precision, reduce the time of channel tuning and provide the automatic monitoring during the experiment.

A dialog program for the evaluation of multichannel spectra

International Nuclear Information System (INIS)

Dietze, G.

1978-06-01

The computer code SPEKT is described for the analysis and manipulation of multichannel spectra in neutron dosimetry. It is a dialog system with a simple command string. The code has mainly been written in FORTRAN. Because of the modular structure of the program a user can add new routines in a simple way. (orig./HP) [de

Light coupling and distribution for Si3N4/SiO2 integrated multichannel single-mode sensing system

Science.gov (United States)

Kaźmierczak, Andrzej; Dortu, Fabian; Schrevens, Olivier; Giannone, Domenico; Bouville, David; Cassan, Eric; Gylfason, Kristinn B.; Sohlström, Hans; Sanchez, Benito; Griol, Amadeu; Hill, Daniel

2009-01-01

We present an efficient and highly alignment-tolerant light coupling and distribution system for a multichannel Si3N4/SiO2 single-mode photonics sensing chip. The design of the input and output couplers and the distribution splitters is discussed. Examples of multichannel data obtained with the system are given.

Ultrasmall and customizable multichannel electrodes for extracellular recordings.

Science.gov (United States)

Piironen, Arto; Weckström, Matti; Vähäsöyrinki, Mikko

2011-03-01

Increasing demand exists for smaller multichannel electrodes that enable simultaneous recordings of many neurons in a noninvasive manner. We report a novel method for manufacturing ultrasmall carbon fiber electrodes with up to seven closely spaced recording sites. The electrodes were designed to minimize damage to neuronal circuitry and to be fully customizable in three dimensions so that their dimensions can be optimally matched to those of the targeted neuron population.

Regret of Multi-Channel Bandit Game in Cognitive Radio Networks

Directory of Open Access Journals (Sweden)

Ma Jun

2016-01-01

Full Text Available The problem of how to evaluate the rate of convergence to Nash equilibrium solutions in the process of channel selection under incomplete information is studied. In this paper, the definition of regret is used to reflect the convergence rates of online algorithms. The process of selecting an idle channel for each secondary user is modeled as a multi-channel bandit game. The definition of the maximal averaged regret is given. Two existing online learning algorithms are used to obtain the Nash equilibrium for each SU. The maximal averaged regrets are used to evaluate the performances of online algorithms. When there is a pure strategy Nash equilibrium in the multi-channel bandit game, the maximal averaged regrets are finite. A cooperation mechanism is also needed in the process of calculating the maximal averaged regrets. Simulation results show the maximal averaged regrets are finite and the online algorithm with greater convergence rate has less maximal averaged regrets.

Car-borne multichannel gamma-ray spectrometric system model CZD-6

International Nuclear Information System (INIS)

Lu Shili; Zhai Yugui; Ma Yanfang; Jiao Cangwen; Zhang Biao

1998-01-01

The car-borne multichannel gamma-ray spectrometric system Mode CZD-6 is composed of a HDY-256 of portable multichannel gamma-ray spectrometer developed by the Beijing Research Institute of Uranium Geology and a large volume scintillation detector. the position for each measurement point is determined by the GPS instrument. Its latitude and longitude, as well as measured 256 channels of γ-spectrometric data are collected by a notebook computer, which can show the 256 channels of spectra for each point during measuring processes. The complete system can be loaded in a field car. This system has been used to environmental radioactive monitoring after calibration by airborne radiometric models in Shijiazhuang, Hebei province. A lot of data confirm that the system works stably and reliably, and is a fast and advanced approach for environmental γ-spectrometric monitoring. It can be used not only to determination of contents of natural radioactive elements in environments, but also to monitoring nuclear pollution and emergency treatment in nuclear accidents significantly

Dimension reduction of frequency-based direct Granger causality measures on short time series.

Science.gov (United States)

Siggiridou, Elsa; Kimiskidis, Vasilios K; Kugiumtzis, Dimitris

2017-09-01

The mainstream in the estimation of effective brain connectivity relies on Granger causality measures in the frequency domain. If the measure is meant to capture direct causal effects accounting for the presence of other observed variables, as in multi-channel electroencephalograms (EEG), typically the fit of a vector autoregressive (VAR) model on the multivariate time series is required. For short time series of many variables, the estimation of VAR may not be stable requiring dimension reduction resulting in restricted or sparse VAR models. The restricted VAR obtained by the modified backward-in-time selection method (mBTS) is adapted to the generalized partial directed coherence (GPDC), termed restricted GPDC (RGPDC). Dimension reduction on other frequency based measures, such the direct directed transfer function (dDTF), is straightforward. First, a simulation study using linear stochastic multivariate systems is conducted and RGPDC is favorably compared to GPDC on short time series in terms of sensitivity and specificity. Then the two measures are tested for their ability to detect changes in brain connectivity during an epileptiform discharge (ED) from multi-channel scalp EEG. It is shown that RGPDC identifies better than GPDC the connectivity structure of the simulated systems, as well as changes in the brain connectivity, and is less dependent on the free parameter of VAR order. The proposed dimension reduction in frequency measures based on VAR constitutes an appropriate strategy to estimate reliably brain networks within short-time windows. Copyright © 2017 Elsevier B.V. All rights reserved.

Research on development of multi-channel analyzer used for monitoring and warning radiation equipment

International Nuclear Information System (INIS)

Nguyen Van Sy; Dang Quang Thieu; Nguyen Thi Bao My

2015-01-01

The subject assigned to this paper presents research on development of multi-channel analyzer used for monitoring and warning environmental radiation equipment under the project KC.05.16/11-15 Research on manufacturing equipment monitoring and warning radiation. In this thematic we have two subjects that need to be resolved such as: i) Designing spectroscopy amplifier block (AMP) duty pulse signals obtained about few hundred millivolts output from scintillation detector preamplifier, amplified as a few volts and the standard Gaussian pulses shaped to connect to the analog-to-digital converter. The spectroscopy amplifier block can change the gain by digital control to respond to the problem of automatic spectrum stability for multi-channel analyzer systems. ii) Designing analog-to-digital converter block (ADC) in accordance with the actual conditions, such as high stability, fast conversion time, high throughput, and it consumes low energy. Selecting suitable microprocessor for fast connection ability, to operate reliably paired with the analog-to-digital converter into a multi-channel analyzer (MCA) serving analysis. (author)

Novel Methods for Measuring Depth of Anesthesia by Quantifying Dominant Information Flow in Multichannel EEGs

Directory of Open Access Journals (Sweden)

Kab-Mun Cha

2017-01-01

Full Text Available In this paper, we propose novel methods for measuring depth of anesthesia (DOA by quantifying dominant information flow in multichannel EEGs. Conventional methods mainly use few EEG channels independently and most of multichannel EEG based studies are limited to specific regions of the brain. Therefore the function of the cerebral cortex over wide brain regions is hardly reflected in DOA measurement. Here, DOA is measured by the quantification of dominant information flow obtained from principle bipartition. Three bipartitioning methods are used to detect the dominant information flow in entire EEG channels and the dominant information flow is quantified by calculating information entropy. High correlation between the proposed measures and the plasma concentration of propofol is confirmed from the experimental results of clinical data in 39 subjects. To illustrate the performance of the proposed methods more easily we present the results for multichannel EEG on a two-dimensional (2D brain map.

Multichannel fiber laser Doppler vibrometer studies of low momentum and hypervelocity impacts

Science.gov (United States)

Posada-Roman, Julio E.; Jackson, David A.; Cole, Mike J.; Garcia-Souto, Jose A.

2017-12-01

A multichannel optical fiber laser Doppler vibrometer was demonstrated with the capability of making simultaneous non-contact measurements of impacts at 3 different locations. Two sets of measurements were performed, firstly using small ball bearings (1 mm-5.5 mm) falling under gravity and secondly using small projectiles (1 mm) fired from an extremely high velocity light gas gun (LGG) with speeds in the range 1 km/s-8 km/s. Determination of impact damage is important for industries such as aerospace, military and rail, where the effect of an impact on the structure can result in a major structural damage. To our knowledge the research reported here demonstrates the first trials of a multichannel fiber laser Doppler vibrometer being used to detect hypervelocity impacts.

Multichannel deconvolution and source detection using sparse representations: application to Fermi project

International Nuclear Information System (INIS)

Schmitt, Jeremy

2011-01-01

This thesis presents new methods for spherical Poisson data analysis for the Fermi mission. Fermi main scientific objectives, the study of diffuse galactic background et the building of the source catalog, are complicated by the weakness of photon flux and the point spread function of the instrument. This thesis proposes a new multi-scale representation for Poisson data on the sphere, the Multi-Scale Variance Stabilizing Transform on the Sphere (MS-VSTS), consisting in the combination of a spherical multi-scale transform (wavelets, curvelets) with a variance stabilizing transform (VST). This method is applied to mono- and multichannel Poisson noise removal, missing data interpolation, background extraction and multichannel deconvolution. Finally, this thesis deals with the problem of component separation using sparse representations (template fitting). (author) [fr

A Receiver-Initiated Collision-Avoidance Protocol for Multi-Channel Networks

Science.gov (United States)

2001-01-01

00-00-2001 to 00-00-2001 4. TITLE AND SUBTITLE A Receiver-Initiated Collision-Avoidance Protocol for Multi-Channel Netowrks 5a. CONTRACT NUMBER...images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 10 19a. NAME OF RESPONSIBLE

An optimal multi-channel memory controller for real-time systems

NARCIS (Netherlands)

Gomony, M.D.; Akesson, K.B.; Goossens, K.G.W.

2013-01-01

Optimal utilization of a multi-channel memory, such as Wide IO DRAM, as shared memory in multi-processor platforms depends on the mapping of memory clients to the memory channels, the granularity at which the memory requests are interleaved in each channel, and the bandwidth and memory capacity

The designing principle and implementation of multi-channel intelligence isotope thickness gauge based on multifunction card PCI-1710

International Nuclear Information System (INIS)

Zhang Bin; Zhao Shujun; Guo Maotian; He Jintian

2006-01-01

The designing principle, the constitution of system and the implementation of multi-channel intelligence isotope thickness gauge are introduced in the paper in detail, which are based on multifunction card PCI-1710. The paper also discusses the primaryprinciple of isotope thickness gauge, correct factor in measurement and complication of calibration. In the following, the whole frame of multi-channel intelligence isotope thickness gauge is given. The functions, the characteristics and the usage of multifunction card PCI-1710 are described. Furthermore, the developing process and the function modules of software are presented. Finally, the real prototype of multi-channel intelligence isotope thickness gauge is introduced, using 241 Am as a radioactive element. (authors)

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...

A novel portable multi-channel analyzer based on high-speed microcontroller

International Nuclear Information System (INIS)

Lou Xinghua; Yi Hongchang; Wang Yuemin

2005-01-01

This paper introduces a novel portable multi-channel analyzer (MCA) based on high-speed microcontroller. The hardware implementation and the software scenario of the MCA are discussed. The MCA has features of high speed, small size and better performances. (authors)

Teachability of collocations: The role of word frequency counts ...

African Journals Online (AJOL)

... beginner/low-intermediate students and only exceed the 2 000-word band from the upper-intermediate learning stage onwards, a suggestion in line with Nation's (2006) discussion on how to teach vocabulary. Keywords: collocation size, controlled productive knowledge, teachability of collocations, word frequency counts, ...

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.

Multi-channel fiber optic dew and humidity sensor

Science.gov (United States)

Limodehi, Hamid E.; Mozafari, Morteza; Amiri, Hesam; Légaré, François

2018-03-01

In this article, we introduce a multi-channel fiber optic dew and humidity sensor which works using a novel method based on relation between surface plasmon resonance (SPR) and water vapor condensation. The proposed sensor can instantly detect moisture or dew formation through its fiber optic channels, separately situated in different places. It enables to simultaneously measure the ambient Relative Humidity (RH) and dew point temperature of several environments with accuracy of 5%.

Multichannel far-infrared phase imaging for fusion plasmas

International Nuclear Information System (INIS)

Young, P.E.; Neikirk, D.P.; Tong, P.P.; Rutledge, D.B.; Luhmann, N.C. Jr.

1985-01-01

A 20-channel far-infrared imaging interferometer system has been used to obtain single-shot density profiles in the UCLA Microtor tokamak. This system differs from conventional multichannel interferometers in that the phase distribution produced by the plasma is imaged onto a single, monolithic, integrated microbolometer linear detector array and provides significantly more channels than previous far-infrared interferometers. The system has been demonstrated to provide diffraction-limited phase images of dielectric targets

Use of multichannel electrogastrography for noninvasive assessment of gastric myoelectrical activity in dogs.

Science.gov (United States)

Koenig, Judith B; Martin, Christina E W; Dobson, Howard; Mintchev, Martin P

2009-01-01

To evaluate whether changes in gastric myoelectrical activity in healthy, awake dogs can be detected via multichannel electrogastrography (EGG). 6 healthy hound-breed dogs. For each dog, 8-channel EGG was performed after food had been withheld for 12 hours and at 30 minutes after subsequent feeding; 60 minutes after feeding, atropine (0.04 mg/kg) was administered IM to induce ileus, and 30 minutes later, EGG was again performed. Mean cycles per minute (cpm) values of the dominant frequency (a measure of the rhythmicity of gastric electrical activity) and mean power ratios (ie, power measured after treatment divided by the power measured when food was withheld) were calculated. Motility of the gastric antrum was assessed via B-mode ultrasonography during the same phases; contractions determined ultrasonographically were correlated with EGG power for each channel in each phase. The criterion for stability (SD of the dominant frequency dogs (only in long-distance channels). The mean power ratios were significantly higher in the postprandial phase than in the ileus phase. Compared with the postprandial phase, significantly fewer contractions per minute were evident ultrasonographically in the ileus and food-withholding phases. There was a significant and good correlation between EGG power and ultrasonographic findings in all 8 channels. Electrogastrography may be useful in assessing gastric myoelectrical activities in awake dogs with naturally occurring gastrointestinal disease, including gastric dilatation-volvulus.

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...

A new method for multi-channel Fabry-Perot spectroscopy of light pulses in the nanosecond regime

International Nuclear Information System (INIS)

Behn, R.

1975-01-01

The demand for powerful multichannel spectrometers raised, e.g., in laser scattering plasma diagnostics, gave rise to the question if it would not be possible to avoid the light losses occuring in the use of multichannel Fabry-Perot spectrometers. These losses can be avoided with the technique presented here. The reflected light is collected and fed back to the interferometer at a different angle. It can thus be recovered for registration in another spectral channel. This method is particularly suitable for the investigation of short light pulses. A spectrum can thus be scanned step by step with full utilization of the transit time of the light pulse. In addition to light recovery, there is another advantage in that only one detector is used for multichannel analysis, thus eliminating calibration problems. In the annex to the report, emission spectres of different dye laser versions are presented and explained. (orig./GG) [de

MHD flow in multichannel U-bends: Screening experiments and theoretical analysis

International Nuclear Information System (INIS)

Reimann, J.; Molokov, S.; Platnieks, I.; Platacis, E.

1993-02-01

In electrically coupled multichannel ducts with a U-bend geometry magnetohydrodynamic effects are expected to cause strongly ununiform distributions of flow rates Q i and pressure drops Δp i in the individual channels. A multichannel U-bend geometry is part of the KfK self-cooled Pb-17 Li blanket design (radial-toroidal-radial channels). However, inserts are proposed which isolate electrically the radial channels (not the toroidal ones). To investigate the multichannel effect (MCE), screening experiments were performed at LAS, Riga, with different flow channel geometries and channel numbers between 1 and 5 and using InGaSn as liquid metal. These experiments were carried out with either Δp i ∼const or Q i ∼const. Hartmann Numbers were varied between 0 and ∼1600 (maximum magnetic field strength: 4.1 T) and Interaction Parameters between 0 and 10000. For experiments with electrically conducting walls between the channels, the volume flow rates in the outer channels are significantly larger than those in the inner channels in the experiments with Δp i ∼const. For Q i ∼const., this tendency is reversed, with the highest pressure drop in the middle channel and the lowest in the outer channels. The flow geometry with electrically separated radial channels, similar to the KfK-design result in a fairly even flow rate and pressure drop distribution. The single channels behave approximately like electrically separated channels; no marked MCE occurrs. A theoretical analysis was carried out to describe the MCE for the multichannel U-bend with thin electrically conducting outside walls. This analysis is based on the Core Flow Approximation (CFA), valid for infinitely large Interaction Parameters and Hartmann Numbers. The theory predicts correctly all tendencies observed for the pressure measurements. Moreover, the method is able to describe in detail the flow structure in the toroidal channel. The most essential result is that the flow rate in the layer close to the

Multichannel approach to studying scalar resonances

International Nuclear Information System (INIS)

Krupa, D.; Surovtsev, Yu.S.

1995-11-01

The multichannel approach to the investigation of resonances is given in order to determine their quantum chromodynamical nature. The formula for the analytic continuation of the N-channel S-matrix to the unphysical sheets of the Riemann surface is given, which is a solution of the N-channel problem in that it enables a prediction of the coupled-process amplitudes on the uniformization plane of the S-matrix. The resonance representations by pairs of complex-conjugate clusters of poles and zeros on the Riemann surface are discussed. The concept of standard clusters as model-independent characteristics of the resonance is developed. 32 refs, 5 figs, 4 tabs

Multichannel Baseband Processor for Wideband CDMA

Science.gov (United States)

Jalloul, Louay M. A.; Lin, Jim

2005-12-01

The system architecture of the cellular base station modem engine (CBME) is described. The CBME is a single-chip multichannel transceiver capable of processing and demodulating signals from multiple users simultaneously. It is optimized to process different classes of code-division multiple-access (CDMA) signals. The paper will show that through key functional system partitioning, tightly coupled small digital signal processing cores, and time-sliced reuse architecture, CBME is able to achieve a high degree of algorithmic flexibility while maintaining efficiency. The paper will also highlight the implementation and verification aspects of the CBME chip design. In this paper, wideband CDMA is used as an example to demonstrate the architecture concept.

Damped Oscillator with Delta-Kicked Frequency

Science.gov (United States)

Manko, O. V.

1996-01-01

Exact solutions of the Schrodinger equation for quantum damped oscillator subject to frequency delta-kick describing squeezed states are obtained. The cases of strong, intermediate, and weak damping are investigated.

Scanning Multichannel Microwave Radiometer (SMMR) Monthly Mean Atmospheric Liquid Water (ALW) By Prabhakara

Data.gov (United States)

National Aeronautics and Space Administration — SMMR_ALW_PRABHAKARA data are Special Multichannel Microwave Radiometer (SMMR) Monthly Mean Atmospheric Liquid Water (ALW) data by Prabhakara.The Prabhakara Scanning...

Objective ARX Model Order Selection for Multi-Channel Human Operator Identification

NARCIS (Netherlands)

Roggenkämper, N; Pool, D.M.; Drop, F.M.; van Paassen, M.M.; Mulder, M.

2016-01-01

In manual control, the human operator primarily responds to visual inputs but may elect to make use of other available feedback paths such as physical motion, adopting a multi-channel control strategy. Hu- man operator identification procedures generally require a priori selection of the model

3D Multi-Channel Networked Visualization System for National LambdaRail, Phase II

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...

Calibration OGSE for a multichannel radiometer for Mars atmosphere studies

Science.gov (United States)

Jiménez, J. J.; Álvarez, F. J.; Gonzalez-Guerrero, M.; Apéstigue, V.; Martin, I.; Fernández, J. M.; Fernán, A. A.; Arruego, I.

2017-09-01

This work describes several OGSEs (Optical Ground Support Equipment) developed by INTA (Spanish Institute of Aerospace Technology - Instituto Nacional de Técnica Aeroespacial) for the calibration and characterization of their self-manufactured multichannel radiometers (Solar Irradiance Sensors - SIS) for planetary atmospheric studies in the frame of some Martian missions at which INTA is participating.

ON SCALAR MESONS FROM THE COMBINED ANALYSIS OF MULTI-CHANNEL pi pi SCATTERING AND J/psi DECAYS

Czech Academy of Sciences Publication Activity Database

Surovtsev, Yu .S.; Bydžovský, Petr; Gutsche, T.; Lyubovitskij, V. E.

2011-01-01

Roč. 26, 3-4 (2011), s. 610-612 ISSN 0217-751X. [11th International Workshop on Meson Production , Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/08/0984 Institutional research plan: CEZ:AV0Z10480505 Keywords : Multi-channel pion-pion scattering * scalar-isoscalar resonances * multichannel analysis Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011

Metasurface for multi-channel terahertz beam splitters and polarization rotators

Science.gov (United States)

Zang, XiaoFei; Gong, HanHong; Li, Zhen; Xie, JingYa; Cheng, QingQing; Chen, Lin; Shkurinov, Alexander P.; Zhu, YiMing; Zhuang, SongLin

2018-04-01

Terahertz beam splitters and polarization rotators are two typical devices with wide applications ranging from terahertz communication to system integration. However, they are faced with severe challenges in manipulating THz waves in multiple channels, which is desirable for system integration and device miniaturization. Here, we propose a method to design ultra-thin multi-channel THz beam splitters and polarization rotators simultaneously. The reflected beams are divided into four beams with nearly the same density under illumination of linear-polarized THz waves, while the polarization of reflected beams in each channel is modulated with a rotation angle or invariable with respect to the incident THz waves, leading to the multi-channel polarization rotator (multiple polarization rotation in the reflective channels) and beam splitter, respectively. Reflective metasurfaces, created by patterning metal-rods with different orientations on a polyimide film, were fabricated and measured to demonstrate these characteristics. The proposed approach provides an efficient way of controlling polarization of THz waves in various channels, which significantly simplifies THz functional devices and the experimental system.

Scene text detection by leveraging multi-channel information and local context

Science.gov (United States)

Wang, Runmin; Qian, Shengyou; Yang, Jianfeng; Gao, Changxin

2018-03-01

As an important information carrier, texts play significant roles in many applications. However, text detection in unconstrained scenes is a challenging problem due to cluttered backgrounds, various appearances, uneven illumination, etc.. In this paper, an approach based on multi-channel information and local context is proposed to detect texts in natural scenes. According to character candidate detection plays a vital role in text detection system, Maximally Stable Extremal Regions(MSERs) and Graph-cut based method are integrated to obtain the character candidates by leveraging the multi-channel image information. A cascaded false positive elimination mechanism are constructed from the perspective of the character and the text line respectively. Since the local context information is very valuable for us, these information is utilized to retrieve the missing characters for boosting the text detection performance. Experimental results on two benchmark datasets, i.e., the ICDAR 2011 dataset and the ICDAR 2013 dataset, demonstrate that the proposed method have achieved the state-of-the-art performance.

Development of data acquisition and analysis software for multichannel detectors

International Nuclear Information System (INIS)

Chung, Y.

1988-06-01

This report describes the development of data acquisition and analysis software for Apple Macintosh computers, capable of controlling two multichannel detectors. With the help of outstanding graphics capabilities, easy-to-use user interface, and several other built-in convenience features, this application has enhanced the productivity and the efficiency of data analysis. 2 refs., 6 figs

A high dutycycle low cost multichannel analyser for electron spectroscopy

International Nuclear Information System (INIS)

Norell, K.E.; Baltzer, P.

1983-03-01

A high dutycycle multichannel analyzer has been designed and used in time-of-flight electron spectroscopy. The memory capacity is 64k counts. The number of channels is 8192 with a time resolution of 100 ns. An oscilloscope is used to display the spectra synchronous with the counting. The unit has been built with standard electronic components. (author)

A multichannel magnetic β-ray spectrometer for rapid measurements of electron spectra

International Nuclear Information System (INIS)

Kariya, Komyo; Morikawa, Kaoru.

1989-01-01

In order to make the magnetic β-ray spectrometer suitable for rapid measurements of electron spectra with short-lived nuclides, twelve small GM counters have been arrayed along the focal plane of a 180deg focusing flat type design. All the signal pulses from each one of these detectors are mixed together onto a single cable. By means of multichannel PHA, each pulse can be traced back to the specific detector which sent it out. In order to avoid time consuming evacuation procedures, the sample source is placed outside a thin window of the preevacuated analyzer chamber. By the use of this multichannel spectrometer a β-ray spectrum with maximum energy up to about 10 MeV can be measured within 1 min or so. Electron spectra measured with 113m In, 119m In and 144 Pr source are shown. (author)

Benchmarking and qualification of the nufreq-npw code for best estimate prediction of multi-channel core stability margins

International Nuclear Information System (INIS)

Taleyarkhan, R.; McFarlane, A.F.; Lahey, R.T. Jr.; Podowski, M.Z.

1988-01-01

The work described in this paper is focused on the development, verification and benchmarking of the NUFREQ-NPW code at Westinghouse, USA for best estimate prediction of multi-channel core stability margins in US BWRs. Various models incorporated into NUFREQ-NPW are systematically compared against the Westinghouse channel stability analysis code MAZDA, which the Mathematical Model was developed in an entirely different manner. The NUFREQ-NPW code is extensively benchmarked against experimental stability data with and without nuclear reactivity feedback. Detailed comparisons are next performed against nuclear-coupled core stability data. A physically based algorithm is developed to correct for the effect of flow development on subcooled boiling. Use of this algorithm (to be described in the full paper) captures the peak magnitude as well as the resonance frequency with good accuracy

Development of a Multichannel Analyzer for modular ADCs

International Nuclear Information System (INIS)

Bannos Rodriguez, U.; Diaz Castro, M.; Rivero Ramirez, D.

2013-01-01

This paper describes the design and construction of a multichannel analyzer with USB interface from ADC module of the Fast ComTec 7074. One PIC18F4550 microprocessor from Microchip, one CPLD isPLSI 1032E from Lattice and one 32Kx8 SRAM memory were used. It also includes details of the programming circuitry and development of program acquisition, storage and display of the spectra using the Qt libraries. Finally, preliminary tests to the device are show. (Author)

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 ...

Astronomical observations with the optical multichannel analyser of the Sao Paulo University

Energy Technology Data Exchange (ETDEWEB)

Codina-Landaberry, S J; de Freitas Pacheco, J A [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

1979-03-01

The first astronomical observations made with the optical multichannel analyser (OMA) of the Sao Paulo University is reported. A detailed description of the instrumentation is given as well as the results derived from the observation of some emission nebulae.

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 ...

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.

Multichannel Baseband Processor for Wideband CDMA

Directory of Open Access Journals (Sweden)

Jim Lin

2005-07-01

Full Text Available The system architecture of the cellular base station modem engine (CBME is described. The CBME is a single-chip multichannel transceiver capable of processing and demodulating signals from multiple users simultaneously. It is optimized to process different classes of code-division multiple-access (CDMA signals. The paper will show that through key functional system partitioning, tightly coupled small digital signal processing cores, and time-sliced reuse architecture, CBME is able to achieve a high degree of algorithmic flexibility while maintaining efficiency. The paper will also highlight the implementation and verification aspects of the CBME chip design. In this paper, wideband CDMA is used as an example to demonstrate the architecture concept.

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...

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...

Personalized multi-channel headphone sound reproduction based on active noise cancellation

NARCIS (Netherlands)

Schobben, D.W.E.; Aarts, R.M.

2005-01-01

A system for headphone signal processing is discussed which gives a listener the same impression as listening to a multi-channel loudspeaker set-up. It is important that this processing is optimized for each individual listener. If this is not the case, large localization errors may occur. In the

Intermediate frequency magnetic field generated by a wireless power transmission device does not cause genotoxicity in vitro.

Science.gov (United States)

Shi, Dejing; Zhu, Chunbo; Lu, Rengui; Mao, Shitong; Qi, Yanhua

2014-10-01

The aim of this study was to evaluate effects of intermediate frequency magnetic fields (IFMF) generated by a wireless power transmission (WPT) based on magnetic resonance from the perspective of cellular genotoxicity on cultured human lens epithelial cells (HLECs). We evaluated the effects of exposure to 90 kHz magnetic fields at 93.36 µT on cellular genotoxicity in vitro for 2 and 4 h. The magnetic flux density is approximately 3.5 times higher than the reference level recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. For assessment of genotoxicity, we studied cellular proliferation, apoptosis and DNA damage by Cell Counting Kit-8 (CCK-8) assay, flow cytometry analysis, alkaline comet assay and phosphorylated histone H2AX (γH2AX) foci formation test. We did not detect any effect of a 90 kHz IFMF generated by WPT based on magnetic resonance on cell proliferation, apoptosis, comet assay, and γH2AX foci formation test. Our results indicated that exposure to 90 kHz IFMF generated by WPT based on magnetic resonance at 93.36 µT for 2 and 4 h does not cause detectable cellular genotoxicity. © 2014 Wiley Periodicals, Inc.

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...

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...

Astronomical observations with the optical multichannel analyser of the Sao Paulo University

International Nuclear Information System (INIS)

Codina-Landaberry, S.J.; Freitas Pacheco, J.A. de

1979-01-01

The first astronomical observations made with the optical multichannel analyser (OMA) of the Sao Paulo University is reported. A detailed description of the instrumentation is given as well as the results derived from the observation of some emission nebulae [pt

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.

A high-throughput, multi-channel photon-counting detector with picosecond timing

International Nuclear Information System (INIS)

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

2009-01-01

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.

Compact and cost-effective multi-channel optical spectrometer for fine FBG sensing in IoT technology

Science.gov (United States)

Konishi, Tsuyoshi; Yamasaki, Yu

2018-02-01

Optical fiber sensor networks have attracted much attention in IoT technology and a fiber Bragg grating is one of key sensor devices there because of their advantages in a high affinity for optical fiber networks, compactness, immunity to electromagnetic interference and so on. Nevertheless, its sensitivity is not always satisfactory so as to be usable together with widespread cost-effective multi-channel spectrometers. In this paper, we introduce a new cost-effective approach for a portable multi-channel spectrometer with high spectral resolution and demonstrates some preliminary experimental results for fine FBG sensing.

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...

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)

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...

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...

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...

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...

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...

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...

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...

Modelling of the dual frequency capacitive sheath in the intermediate pressure range

International Nuclear Information System (INIS)

Boyle, P C; Robiche, J; Turner, M M

2004-01-01

The nonlinearity of the plasma sheath in dual frequency capacitively coupled reactors is investigated for frequencies well above the ion plasma frequency. This work focuses on the behaviour of the voltage and the sheath width with respect to the driving current source and the collisionality regime. For typical plasma processing applications, the gas pressure ranges from a few milliTorrs to hundreds of milliTorrs, and the ion dynamics span different collisional regimes. To describe these different ion dynamics, we have used a collisionless model and a variable mobility model. The sheath widths and the voltages obtained from these two models have then been compared

An Observational Study of Intermediate Band Students' Self-Regulated Practice Behaviors

Science.gov (United States)

Miksza, Peter; Prichard, Stephanie; Sorbo, Diana

2012-01-01

The purpose of this study was to investigate intermediate musicians' self-regulated practice behaviors. Thirty sixth- through eighth-grade students were observed practicing band repertoire individually for 20 min. Practice sessions were coded according to practice frame frequency and duration, length of musical passage selected, most prominent…

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...

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...

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...

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...

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...

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...

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)

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....

Joint time-frequency analysis of EEG signals based on a phase-space interpretation of the recording process

Science.gov (United States)

Testorf, M. E.; Jobst, B. C.; Kleen, J. K.; Titiz, A.; Guillory, S.; Scott, R.; Bujarski, K. A.; Roberts, D. W.; Holmes, G. L.; Lenck-Santini, P.-P.

2012-10-01

Time-frequency transforms are used to identify events in clinical EEG data. Data are recorded as part of a study for correlating the performance of human subjects during a memory task with pathological events in the EEG, called spikes. The spectrogram and the scalogram are reviewed as tools for evaluating spike activity. A statistical evaluation of the continuous wavelet transform across trials is used to quantify phase-locking events. For simultaneously improving the time and frequency resolution, and for representing the EEG of several channels or trials in a single time-frequency plane, a multichannel matching pursuit algorithm is used. Fundamental properties of the algorithm are discussed as well as preliminary results, which were obtained with clinical EEG data.

Improvement of force-sensor-based heart rate estimation using multichannel data fusion.

Science.gov (United States)

Bruser, Christoph; Kortelainen, Juha M; Winter, Stefan; Tenhunen, Mirja; Parkka, Juha; Leonhardt, Steffen

2015-01-01

The aim of this paper is to present and evaluate algorithms for heartbeat interval estimation from multiple spatially distributed force sensors integrated into a bed. Moreover, the benefit of using multichannel systems as opposed to a single sensor is investigated. While it might seem intuitive that multiple channels are superior to a single channel, the main challenge lies in finding suitable methods to actually leverage this potential. To this end, two algorithms for heart rate estimation from multichannel vibration signals are presented and compared against a single-channel sensing solution. The first method operates by analyzing the cepstrum computed from the average spectra of the individual channels, while the second method applies Bayesian fusion to three interval estimators, such as the autocorrelation, which are applied to each channel. This evaluation is based on 28 night-long sleep lab recordings during which an eight-channel polyvinylidene fluoride-based sensor array was used to acquire cardiac vibration signals. The recruited patients suffered from different sleep disorders of varying severity. From the sensor array data, a virtual single-channel signal was also derived for comparison by averaging the channels. The single-channel results achieved a beat-to-beat interval error of 2.2% with a coverage (i.e., percentage of the recording which could be analyzed) of 68.7%. In comparison, the best multichannel results attained a mean error and coverage of 1.0% and 81.0%, respectively. These results present statistically significant improvements of both metrics over the single-channel results (p < 0.05).

High-pressure duo-multichannel soft x-ray spectrometer for tokamak plasma diagnostics

International Nuclear Information System (INIS)

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 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 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

On multichannel film dosimetry with channel-independent perturbations

International Nuclear Information System (INIS)

Méndez, I.; Peterlin, P.; Hudej, R.; Strojnik, A.; Casar, B.

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 byMicke et al. [“Multichannel film dosimetry with nonuniformity correction,” Med. Phys. 38, 2523–2534 (2011)] and Mayer et al. [“Enhanced dosimetry procedures and assessment for EBT2 radiochromic film,” Med. Phys. 39, 2147–2155 (2012)]. 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 γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 ( http://www.iriseu.com ). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. Results: The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke–Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning

On multichannel film dosimetry with channel-independent perturbations

Energy Technology Data Exchange (ETDEWEB)

Méndez, I., E-mail: nmendez@onko-i.si; Peterlin, P.; Hudej, R.; Strojnik, A.; Casar, B. [Department of Medical Physics, Institute of Oncology Ljubljana, Zaloška cesta 2, Ljubljana 1000 (Slovenia)

2014-01-15

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 byMicke et al. [“Multichannel film dosimetry with nonuniformity correction,” Med. Phys. 38, 2523–2534 (2011)] and Mayer et al. [“Enhanced dosimetry procedures and assessment for EBT2 radiochromic film,” Med. Phys. 39, 2147–2155 (2012)]. 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 γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 ( http://www.iriseu.com ). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. Results: The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke–Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning

Modeling and optimization of the multichannel spark discharge

International Nuclear Information System (INIS)

Zhang Zhi-Bo; Wu Yun; Jia Min; Song Hui-Min; Li Ying-Hong; Sun Zheng-Zhong

2017-01-01

This paper reports a novel analytic model of this multichannel spark discharge, considering the delay time in the breakdown process, the electric transforming of the discharge channel from a capacitor to a resistor induced by the air breakdown, and the varying plasma resistance in the discharge process. The good agreement between the experimental and the simulated results validated the accuracy of this model. Based on this model, the influence of the circuit parameters on the maximum discharge channel number (MDCN) is investigated. Both the input voltage amplitude and the breakdown voltage threshold of each discharge channel play a critical role. With the increase of the input voltage and the decrease of the breakdown voltage, the MCDN increases almost linearly. With the increase of the discharge capacitance, the MDCN first rises and then remains almost constant. With the increase of the circuit inductance, the MDCN increases slowly but decreases quickly when the inductance increases over a certain value. There is an optimal value of the capacitor connected to the discharge channel corresponding to the MDCN. Finally, based on these results, to shorten the discharge time, a modified multichannel discharge circuit is developed and validated by the experiment. With only 6-kV input voltage, 31-channels discharge is achieved. The breakdown voltage of each electrode gap is larger than 3 kV. The modified discharge circuit is certain to be widely used in the PSJA flow control field. (paper)

Massive parallel optical pattern recognition and retrieval via a two-stage high-capacity multichannel holographic random access memory system

International Nuclear Information System (INIS)

Cai, Luzhong; Liu, Hua-Kuang

2000-01-01

The multistage holographic optical random access memory (HORAM) system reported recently by Liu et al. provides a new degree of freedom for improving storage capacity. We further present a theoretical and practical analysis of the HORAM system with experimental results. Our discussions include the system design and geometrical requirements, its applications for multichannel pattern recognition and associative memory, the 2-D and 3-D information storage capacity, and multichannel image storage and retrieval via VanderLugt correlator (VLC) filters and joint transform holograms. A series of experiments are performed to demonstrate the feasibility of the multichannel pattern recognition and image retrieval with both the VLC and joint transform correlator (JTC) architectures. The experimental results with as many as 2025 channels show good agreement with the theoretical analysis. (c) 2000 Society of Photo-Optical Instrumentation Engineers

Discriminability of Single and Multichannel Intracortical Microstimulation within Somatosensory Cortex

Directory of Open Access Journals (Sweden)

Cynthia Kay Overstreet

2016-12-01

Full Text Available The addition of tactile and proprioceptive feedback to neuroprosthetic limbs is expected to significantly improve the control of these devices. Intracortical microstimulation (ICMS of somatosensory cortex is a promising method of delivering this sensory feedback. To date, the main focus of somatosensory ICMS studies has been to deliver discriminable signals, corresponding to varying intensity, to a single location in cortex. However, multiple independent and simultaneous streams of sensory information will need to be encoded by ICMS to provide functionally relevant feedback for a neuroprosthetic limb (e.g. encoding contact events and pressure on multiple digits.In this study, we evaluated the ability of an awake, behaving non-human primate (Macaca mulatta to discriminate ICMS stimuli delivered on multiple electrodes spaced within somatosensory cortex. We delivered serial stimulation on single electrodes to evaluate the discriminability of sensations corresponding to ICMS of distinct cortical locations. Additionally, we delivered trains of multichannel stimulation, derived from a tactile sensor, synchronously across multiple electrodes. Our results indicate that discrimination of multiple ICMS stimuli is a challenging task, but that discriminable sensory percepts can be elicited by both single and multichannel ICMS on electrodes spaced within somatosensory cortex.

How to evaluate multichannel communication packages: a case study on mortgage information

NARCIS (Netherlands)

Herijgers, M.L.C.; Pander Maat, H.L.W.

2015-01-01

Complex decision-making is often supported not by single messages but by multichannel communication packages that need to be evaluated in their own right. The purpose of this paper is to present a new analytic approach to this package evaluation task combining textual analysis, functionalanalysis

A multi-channel data acquisition system with high resolution based on microcomputer

International Nuclear Information System (INIS)

An Qi; Wang Yanfang; Xing Tao

1995-01-01

The paper introduces the principle of a multi-channel data acquisition system with high resolution based on the microcomputer.The system consists of five parts.They are analog-to-digital converter, data buffer area, trigger logic circuit, control circuit, and digital-to-analog converter

Range based power control for multi-radio multi-channel wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-08-01

Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in Wireless Mesh Networks (WMNs). In this paper, researchers present a range based dynamic power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified...

Intertidal soft-sediment community does not respond to disturbance as postulated by the intermediate disturbance hypothesis

Science.gov (United States)

Gerwing, Travis G.; Allen Gerwing, Alyssa M.; Macdonald, Tara; Cox, Kieran; Juanes, Francis; Dudas, Sarah E.

2017-11-01

The Intermediate Disturbance Hypothesis (IDH) predicts that disturbances of an intermediate frequency or intensity will maximize community biodiversity/richness. Once almost universally accepted, controversy now surrounds this hypothesis, and there have even been calls for its abandonment. Therefore, we experimentally evaluated if an infaunal community along the north coast of British Columbia, Canada, would respond to disturbances as predicted by the IDH. The characteristics of this soft-sediment intertidal mudflat (productivity, species pool, population growth rate) maximized our chances of finding evidence to support the IDH. More specifically, we tested if intermediate severities and frequencies of disturbance maximized infaunal community richness by mechanically disturbing sediment, and varying the intensity (0%, 25%, 50%, 75%, and 100% of the surface area of a plot disturbed) and frequency of sediment disturbance (never, once, twice, and every week during a four week period). No effect of frequency or intensity of sediment disturbance on community richness was observed. Further, none of our experimental treatments were statistically different than the controls. This is likely due to the subtle difference between successional stages in this soft-sediment habitat (difference of less than one taxa between treatments). Therefore, in habitats whose productivity, regional species pool, and population growth rates would otherwise suggest a response to disturbances as predicted by the IDH, minor differences between successional stages may result in richness patterns that deviate from those predicted by the IDH.

Miniature multichannel analyzer for process monitoring

International Nuclear Information System (INIS)

Halbig, J.K.; Klosterbuer, S.F.; Russo, P.A.; Sprinkle, J.K. Jr.; Stephens, M.M.; Wiig, L.G.; Ianakiev, K.D.

1993-01-01

A new, 4,000-channel analyzer has been developed for gamma-ray spectroscopy applications. A design philosophy of hardware and software building blocks has been combined with design goals of simplicity, compactness, portability, and reliability. The result is a miniature, modular multichannel analyzer (MMMCA), which offers solution to a variety of nondestructive assay (NDA) needs in many areas of general application, independent of computer platform or operating system. Detector-signal analog electronics, the bias supply, and batteries are included in the virtually pocket-size, low-power MMMCA unit. The MMMCA features digital setup and control, automated data reduction, and automated quality assurance. Areas of current NDA applications include on-line continuous (process) monitoring, process material holdup measurements, and field inspections

A Low-cost Multi-channel Analogue Signal Generator

CERN Document Server

Muller, F; 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 implementation of the signal generator is presented as well as an application where it was successfully utilized.

Development of multichannel system for nuclear radiation spectrometry based on an embedded control and acquisition device Myrio-1900

International Nuclear Information System (INIS)

Hernandez D, S.

2016-01-01

This work describes the design a multichannel analyzer system 4096 channels (Mca) for gamma radiation spectrometry. The multichannel analyzer has as its main component an embedded company National Instruments model NI (Myrio-1900) module, which is integrated by a step of converting analog to digital signals (A / D) and digital-to-analog (D / A) a programmable gate array, and a processor real time (Rt). Through this module the pulses generated by the detector to be processed and subsequently forming the multichannel analyzer are acquired. In addition, a graphical user interface designed to make more use friendly system from a personal computer (Pc), embedded programming module and the user interface was done with the LabVIEW programming environment. tests with different sources of radiation ("6"0Co, "2"2"6Ra, "1"3"7Cs) and semiconductor detectors (Ge) and scintillation (Na) were made. Getting results satisfactory. (Author)

Multiple multichannel spectra acquisition and processing system with intelligent interface

International Nuclear Information System (INIS)

Chen Ying; Wei Yixiang; Qu Jianshi; Zheng Futang; Xu Shengkui; Xie Yuanming; Qu Xing; Ji Weitong; Qiu Xuehua

1986-01-01

A Multiple multichannel spectra acquisition and processing system with intelligent interface is described. Sixteen spectra measured with various lengths, channel widths, back biases and acquisition times can be identified and collected by the intelligent interface simultaneously while the connected computer is doing data processing. The execution time for the Ge(Li) gamma-ray spectrum analysis software on IBM PC-XT is about 55 seconds

Asymptotically exact solution of the multi-channel resonant-level model

International Nuclear Information System (INIS)

Zhang Guangming; Su Zhaobin; Yu Lu.

1994-01-01

An asymptotically exact partition function of the multi-channel resonant-level model is obtained through Tomonaga-Luttinger bosonization. A Fermi-liquid vs. non-Fermi-liquid transition, resulting from a competition between the Kondo and X-ray edge physics, is elucidated explicitly via the renormalization group theory. In the strong-coupling limit, the model is renormalized to the Toulouse limit. (author). 20 refs, 1 fig

The software for the USB-based multi-channel analyzer system

International Nuclear Information System (INIS)

Zhou Tong; Wei Yixiang

2002-01-01

A new type of multi-channel analyzer system is introduced, which takes advantage of Universal Serial Bus to communicate with computer and gets the merit of fast speed, universality and Plug and Play. The authors discussed the framework of the system, primary functions, display of spectrum date and the way of communication with hardware. The environment of the program is Visual Basic 6.0

A multichannel bioimpedance monitor for full-body blood flow monitoring

Czech Academy of Sciences Publication Activity Database

Vondra, Vlastimil; Jurák, Pavel; Viščor, Ivo; Halámek, Josef; Leinveber, P.; Matějková, M.; Soukup, L.

2016-01-01

Roč. 61, č. 1 (2016), s. 107-118 ISSN 0013-5585 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA ČR GAP102/12/2034 Institutional support: RVO:68081731 Keywords : bioimpedance * blood flow * cardiac output * multichannel measurement * non- invasive measurements * pulse wave velocity Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 0.915, year: 2016

Multichannel perimetric alterations in systemic lupus erythematosus treated with hydroxychloroquine

Directory of Open Access Journals (Sweden)

David P. Piñero

2017-04-01

Some achromatic and color vision alterations may be present in SLE, especially when treated with hydroxychloroquine. The sensitivity losses detected in the chromatic channels in the central zone of the visual field were consistent with the results of the FM 100 Hue color test. Likewise, the multichannel perimetry detected sensitivity losses in the parafoveal area for both chromatic channels, especially for the blue-yellow.

Optimization of multi-channel neutron focusing guides for extreme sample environments

International Nuclear Information System (INIS)

Di Julio, D D; Lelièvre-Berna, E; Andersen, K H; Bentley, P M; Courtois, P

2014-01-01

In this work, we present and discuss simulation results for the design of multichannel neutron focusing guides for extreme sample environments. A single focusing guide consists of any number of supermirror-coated curved outer channels surrounding a central channel. Furthermore, a guide is separated into two sections in order to allow for extension into a sample environment. The performance of a guide is evaluated through a Monte-Carlo ray tracing simulation which is further coupled to an optimization algorithm in order to find the best possible guide for a given situation. A number of population-based algorithms have been investigated for this purpose. These include particle-swarm optimization, artificial bee colony, and differential evolution. The performance of each algorithm and preliminary results of the design of a multi-channel neutron focusing guide using these methods are described. We found that a three-channel focusing guide offered the best performance, with a gain factor of 2.4 compared to no focusing guide, for the design scenario investigated in this work.

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.

Multichannel euv spectroscopy of high temperature plasmas

International Nuclear Information System (INIS)

Fonck, R.J.

1983-11-01

Spectroscopy of magnetically confined high temperature plasmas in the visible through x-ray spectral ranges deals primarily with the study of impurity line radiation or continuum radiation. Detailed knowledge of absolute intensities, temporal behavior, and spatial distributions of the emitted radiation is desired. As tokamak facilities become more complex, larger, and less accessible, there has been an increased emphasis on developing new instrumentation to provide such information in a minimum number of discharges. The availability of spatially-imaging detectors for use in the vacuum ultraviolet region (especially the intensified photodiode array) has generated the development of a variety of multichannel spectrometers for applications on tokamak facilities

Technical features of the system used to perform multichannel urethral pressure profilometry

NARCIS (Netherlands)

Messelink, E. J.; Dobbe, I.; Kools, C.; Dabhoiwala, N. F.; Dijkhuizen, T.; Schneider, P.; Lettinga, K. P.; Kurth, K.

1997-01-01

Multichannel Urethral Pressure Profilometry (MCUPP) is a method used to get more information on the pressure distribution within the female urethra. This information may be of value in the diagnostic work up of women with urinary incontinence. Different systems are used for this technique. The pump

Exploiting the opportunities of Internet and multi-channel pricing : An exploratory research

NARCIS (Netherlands)

Sotgiu, Francesca; Ancarani, Fabio

2004-01-01

Smart firms are not worried about the impact of the Internet on pricing, but realise that they have the unique opportunity to exploit new options and improve their marketing performance. Multi-channel pricing is one of the most interesting opportunities firms can exploit in the digital economy.

Schwinger variational principle in the nuclear two-body problem and multichannel theory

International Nuclear Information System (INIS)

Zubarev, A.L.; Podkopaev, A.P.

1978-01-01

The aim of the investigation is to study the Schwinger variational principle in the nuclear two-body problem and the multichannel theory. An approach is proposed to problems of the potential scattering based on the substitution of the exact potential operator V by the finite rank operator Vsup((n)) with which the dynamic equations are solved exactly. The functionals obtained for observed values coincide with corresponding expressions derived by the Schwinger variational principle with the set of test functions. The determination of the Schwinger variational principle is given. The method is given for finding amplitude of the double-particle scattering with the potential Vsup((n)). The corresponding amplitudes are constructed within the framework of the multichannel potential model. Interpolation formula for determining amplitude, which describes with high accuracy a process of elastic scattering for any energies, is obtained. On the basis of the above method high-energy amplitude may be obtained within the range of small and large scattering angles

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....

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...

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...

Vibration analysis of three guyed tower designs for intermediate size wind turbines

Science.gov (United States)

Christie, R. J.

1982-01-01

Three guyed tower designs were analyzed for intermediate size wind turbines. The four lowest natural frequencies of vibration of the three towers concepts were estimated. A parametric study was performed on each tower to determine the effect of varying such tower properties as the inertia and stiffness of the tower and guys, the inertia values of the nacelle and rotor, and the rotational speed of the rotor. Only the two lowest frequencies were in a range where they could be excited by the rotor blade passing frequencies. There two frequencies could be tuned by varying the guy stiffness, the guy attachment point on the tower, the tower and mass stiffness, and the nacelle/rotor/power train masses.

Intermediate treatments

Science.gov (United States)

John R. Jones; Wayne D. Shepperd

1985-01-01

Intermediate treatments are those applied after a new stand is successfully established and before the final harvest. These include not only intermediate cuttings - primarily thinning - but also fertilization, irrigation, and protection of the stand from damaging agents.

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

DEFF Research Database (Denmark)

Søndergaard, Peter Lempel; Decorsiere, Remi Julien Blaise; Dau, Torsten

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...

Development of refined MCNPX-PARET multi-channel model for transient analysis in research reactors

Energy Technology Data Exchange (ETDEWEB)

Kalcheva, S.; Koonen, E. [SCK-CEN, BR2 Reactor Dept., Boeretang 200, 2400 Mol (Belgium); Olson, A. P. [RERTR Program, Nuclear Engineering Div., Argonne National Laboratory, Cass Avenue, Argonne, IL 60439 (United States)

2012-07-01

Reactivity insertion transients are often analyzed (RELAP, PARET) using a two-channel model, representing the hot assembly with specified power distribution and an average assembly representing the remainder of the core. For the analysis of protected by the reactor safety system transients and zero reactivity feedback coefficients this approximation proves to give adequate results. However, a more refined multi-channel model representing the various assemblies, coupled through the reactivity feedback effects to the whole reactor core is needed for the analysis of unprotected transients with excluded over power and period trips. In the present paper a detailed multi-channel PARET model has been developed which describes the reactor core in different clusters representing typical BR2 fuel assemblies. The distribution of power and reactivity feedback in each cluster of the reactor core is obtained from a best-estimate MCNPX calculation using the whole core geometry model of the BR2 reactor. The sensitivity of the reactor response to power, temperature and energy distributions is studied for protected and unprotected reactivity insertion transients, with zero and non-zero reactivity feedback coefficients. The detailed multi-channel model is compared vs. simplified fewer-channel models. The sensitivities of transient characteristics derived from the different models are tested on a few reactivity insertion transients with reactivity feedback from coolant temperature and density change. (authors)

Processing and Analysis of Multichannel Extracellular Neuronal Signals: State-of-the-art and Challenges

Directory of Open Access Journals (Sweden)

Mufti eMahmud

2016-06-01

Full Text Available In recent years multichannel neuronal signal acquisition systems have allowed scientists to focus on research questions which were otherwise impossible. They act as a powerful means to study brain (dysfunctions in in-vivo and in in-vitro animal models. Typically, each session of electrophysiological experiments with multichannel data acquisition systems generate large amount of raw data. For example, a 128 channel signal acquisition system with 16 bits A/D conversion and 20 kHz sampling rate will generate approximately 17 GB data per hour (uncompressed. This poses an important and challenging problem of inferring conclusions from the large amounts of acquired data. Thus, automated signal processing and analysis tools are becoming a key component in neuroscience research, facilitating extraction of relevant information from neuronal recordings in a reasonable time. The purpose of this review is to introduce the reader to the current state-of-the-art of open-source packages for (semiautomated processing and analysis of multichannel extracellular neuronal signals (i.e., neuronal spikes, local field potentials, electroencephalogram, etc., and the existing Neuroinformatics infrastructure for tool and data sharing. The review is concluded by pinpointing some major challenges that are to be faced, which include the development of novel benchmarking techniques, cloud-based distributed processing and analysis tools, as well as defining novel means to share and standardize data.

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,

The design of multi-channel pulse amplitude analyzer based on ARM micro controller

International Nuclear Information System (INIS)

Li Hai; Li Xiang; Liu Caixue

2010-01-01

It introduces the design of multi-channel pulse amplitude analyzer based on embedded ARM micro-controller. The embedded and real-time system μC/OS-II builds up the real-time and stability of the system and advances the integration. (authors)

Multichannel customer segmentation : does the after-sales channel matter? : a replication and extension

NARCIS (Netherlands)

Keyser, A.; Schepers, J.J.L.; Konus, U.

2015-01-01

Segmentation is critical in developing a successful multichannel customer management strategy. Multiple researchers recognized the need to adopt a multi-stage customer journey perspective, taking into account the channels used for information search and product purchase. This paper aims to advance

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...

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...

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....

Analysis of flow distribution instability in parallel thin rectangular multi-channel system

Energy Technology Data Exchange (ETDEWEB)

Xia, G.L. [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an City 710049 (China); Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin City 150001 (China); Su, G.H., E-mail: ghsu@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an City 710049 (China); Peng, M.J. [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin City 150001 (China)

2016-08-15

Highlights: • Flow distribution instability in parallel thin rectangular multi-channel system is studied using RELAP5 codes. • Flow excursion may bring parallel heating channel into the density wave oscillations region. • Flow distribution instability is more likely to happen at low power/flow ratio conditions. • The increase of channel number will not affect the flow distribution instability boundary. • Asymmetry inlet throttling and heating will make system more unstable. - Abstract: The flow distribution instability in parallel thin rectangular multi-channel system has been researched in the present study. The research model of parallel channel system is established by using RELAP5/MOD3.4 codes. The transient process of flow distribution instability is studied at imposed inlet mass flow rate and imposed pressure drop conditions. The influence of heating power, mass flow rate, system pressure and channel number on flow distribution instability are analyzed. Furthermore, the flow distribution instability of parallel two-channel system under asymmetric inlet throttling and heating power is studied. The results show that, if multi-channel system operates at the negative slope region of channel ΔP–G curve, small disturbance in pressure drop will lead to flow redistribution between parallel channels. Flow excursion may bring the operating point of heating channel into the density-wave oscillations region, this will result in out-phase or in-phase flow oscillations. Flow distribution instability is more likely to happen at low power/flow ratio conditions, the stability of parallel channel system increases with system pressure, the channel number has a little effect on system stability, but the asymmetry inlet throttling or heating power will make the system more unstable.

Multichannel Dynamic Fourier-Transform IR Spectrometer

Science.gov (United States)

Balashov, A. A.; Vaguine, V. A.; Golyak, Il. S.; Morozov, A. N.; Khorokhorin, A. I.

2017-09-01

A design of a multichannel continuous scan Fourier-transform IR spectrometer for simultaneous recording and analysis of the spectral characteristics of several objects is proposed. For implementing the design, a multi-probe fiber is used, constructed from several optical fibers connected into a single optical connector and attached at the output of the interferometer. The Fourier-transform spectrometer is used as a signal modulator. Each fiber is individually mated with an investigated sample and a dedicated radiation detector. For the developed system, the radiation intensity of the spectrometer is calculated from the condition of the minimum spectral resolution and parameters of the optical fibers. Using the proposed design, emission spectra of a gas-discharge neon lamp have been recorded using a single fiber 1 mm in diameter with a numerical aperture NA = 0.22.

Optimal spatiotemporal representation of multichannel EEG for recognition of brain states associated with distinct visual stimulus

Science.gov (United States)

Hramov, Alexander; Musatov, Vyacheslav Yu.; Runnova, Anastasija E.; Efremova, Tatiana Yu.; Koronovskii, Alexey A.; Pisarchik, Alexander N.

2018-04-01

In the paper we propose an approach based on artificial neural networks for recognition of different human brain states associated with distinct visual stimulus. Based on the developed numerical technique and the analysis of obtained experimental multichannel EEG data, we optimize the spatiotemporal representation of multichannel EEG to provide close to 97% accuracy in recognition of the EEG brain states during visual perception. Different interpretations of an ambiguous image produce different oscillatory patterns in the human EEG with similar features for every interpretation. Since these features are inherent to all subjects, a single artificial network can classify with high quality the associated brain states of other subjects.

Nondestructive measurement of tomato postharvest quality using a multichannel hyperspectral imaging probe

Science.gov (United States)

A multichannel hyperspectral imaging probe with 30 optic fibers covering the wavelength range of 550-1,650 nm and the light source-detector distances of 1.5-36 mm was recently developed for optical property measurement and quality evaluation of food products with flat or curved surface. This paper r...

Multiple-state based power control for multi-radio multi-channel wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-01-01

Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint...

A Novel Partial Discharge Ultra-High Frequency Signal De-Noising Method Based on a Single-Channel Blind Source Separation Algorithm

Directory of Open Access Journals (Sweden)

Liangliang Wei

2018-02-01

Full Text Available To effectively de-noise the Gaussian white noise and periodic narrow-band interference in the background noise of partial discharge ultra-high frequency (PD UHF signals in field tests, a novel de-noising method, based on a single-channel blind source separation algorithm, is proposed. Compared with traditional methods, the proposed method can effectively de-noise the noise interference, and the distortion of the de-noising PD signal is smaller. Firstly, the PD UHF signal is time-frequency analyzed by S-transform to obtain the number of source signals. Then, the single-channel detected PD signal is converted into multi-channel signals by singular value decomposition (SVD, and background noise is separated from multi-channel PD UHF signals by the joint approximate diagonalization of eigen-matrix method. At last, the source PD signal is estimated and recovered by the l1-norm minimization method. The proposed de-noising method was applied on the simulation test and field test detected signals, and the de-noising performance of the different methods was compared. The simulation and field test results demonstrate the effectiveness and correctness of the proposed method.

Fast multichannel analog storage system

International Nuclear Information System (INIS)

Freytag, D.R.

1982-11-01

A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

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.

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.

Multichannel bolometer for radiation measurements on the TCA tokamak

International Nuclear Information System (INIS)

Joye, B.; Marmillod, P.; Nowak, S.

1986-01-01

A multichannel radiation bolometer has been developed for the Tokamak Chauffage Alfven (TCA) tokamak. It has 16 equally spaced chords that view the plasma through a narrow horizontal slit. Almost an entire vertical plasma cross section can be observed. The bolometer operates on the basis of a semiconducting element which serves as a temperature-dependent resistance. A new electronic circuit has been developed which takes advantage of the semiconductor characteristics of the detector by using feedback techniques. Measurements made with this instrument are discussed

Polarization control of multi-photon absorption under intermediate femtosecond laser field

International Nuclear Information System (INIS)

Cheng Wenjing; Liang Guo; Wu Ping; Liu Pei; Jia Tianqing; Sun Zhenrong; Zhang Shian

2017-01-01

It has been shown that the femtosecond laser polarization modulation is a very simple and well-established method to control the multi-photon absorption process by the light–matter interaction. Previous studies mainly focused on the multi-photon absorption control in the weak field. In this paper, we further explore the polarization control behavior of multi-photon absorption process in the intermediate femtosecond laser field. In the weak femtosecond laser field, the second-order perturbation theory can well describe the non-resonant two-photon absorption process. However, the higher order nonlinear effect (e.g., four-photon absorption) can occur in the intermediate femtosecond laser field, and thus it is necessary to establish new theoretical model to describe the multi-photon absorption process, which includes the two-photon and four-photon transitions. Here, we construct a fourth-order perturbation theory to study the polarization control behavior of this multi-photon absorption under the intermediate femtosecond laser field excitation, and our theoretical results show that the two-photon and four-photon excitation pathways can induce a coherent interference, while the coherent interference is constructive or destructive that depends on the femtosecond laser center frequency. Moreover, the two-photon and four-photon transitions have the different polarization control efficiency, and the four-photon absorption can obtain the higher polarization control efficiency. Thus, the polarization control efficiency of the whole excitation process can be increased or decreased by properly designing the femtosecond laser field intensity and laser center frequency. These studies can provide a clear physical picture for understanding and controlling the multi-photon absorption process in the intermediate femtosecond laser field, and also can provide a theoretical guidance for the future experimental realization. (paper)

Magnetic excitations in intermediate valence semiconductors with singlet ground state

International Nuclear Information System (INIS)

Kikoin, K.A.; Mishchenko, A.S.

1994-01-01

The explanation of the origin inelastic peaks in magnetic neutron scattering spectra of the mixed-valent semiconductor SmB 6 is proposed. It is shown that the excitonic theory of intermediate valence state not only gives the value of the peak frequency but also explains the unusual angular dependence of intensity of inelastic magnetic scattering and describes the dispersion of magnetic excitations in good agreement with experiment

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.

Spectrum-efficient multi-channel design for coexisting IEEE 802.15.4 networks: A stochastic geometry approach

KAUST Repository

Elsawy, Hesham

2014-07-01

For networks with random topologies (e.g., wireless ad-hoc and sensor networks) and dynamically varying channel gains, choosing the long term operating parameters that optimize the network performance metrics is very challenging. In this paper, we use stochastic geometry analysis to develop a novel framework to design spectrum-efficient multi-channel random wireless networks based on the IEEE 802.15.4 standard. The proposed framework maximizes both spatial and time domain frequency utilization under channel gain uncertainties to minimize the number of frequency channels required to accommodate a certain population of coexisting IEEE 802.15.4 networks. The performance metrics are the outage probability and the self admission failure probability. We relax the single channel assumption that has been used traditionally in the stochastic geometry analysis. We show that the intensity of the admitted networks does not increase linearly with the number of channels and the rate of increase of the intensity of the admitted networks decreases with the number of channels. By using graph theory, we obtain the minimum required number of channels to accommodate a certain intensity of coexisting networks under a self admission failure probability constraint. To this end, we design a superframe structure for the coexisting IEEE 802.15.4 networks and a method for time-domain interference alignment. © 2002-2012 IEEE.

Multichannel intraluminal impedance monitoring in the evaluation of patients with non-obstructive Dysphagia

NARCIS (Netherlands)

Conchillo, José M.; Nguyen, Nam Q.; Samsom, Melvin; Holloway, Richard H.; Smout, André J. P. M.

2005-01-01

BACKGROUND: Non-obstructive dysphagia (NOD) often poses diagnostic problems. The aim of this study was to evaluate the value of the addition of multichannel intraluminal impedance (MII) recording to esophageal manometry in the work-up of patients with NOD. METHODS: A total of 40 consecutive patients

Multichannel intraluminal impedance monitoring in the evaluation of patients with non-obstructive dysphagia

NARCIS (Netherlands)

Conchillo, JM; Nguyen, NQ; Samsom, M; Holloway, RH; Smout, AJPM

2005-01-01

BACKGROUND: Non-obstructive dysphagia (NOD) often poses diagnostic problems. The aim of this study was to evaluate the value of the addition of multichannel intraluminal impedance (MII) recording to esophageal manometry in the work-up of patients with NOD. METHODS: A total of 40 consecutive patients

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...

Monte Carlo uncertainty analysis of dose estimates in radiochromic film dosimetry with single-channel and multichannel algorithms.

Science.gov (United States)

Vera-Sánchez, Juan Antonio; Ruiz-Morales, Carmen; González-López, Antonio

2018-03-01

To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes. From this numerical representation, traditional parameters of uncertainty analysis as the standard deviations and bias are calculated. Moreover, these numerical representations are used to investigate the shape of the probability density functions of the output magnitudes. Also, another calibration film is read in four EPSON scanners (two V800 and two 10000XL) and the uncertainty analysis is carried out with the four images. The dose estimates of single-channel and multichannel algorithms show a Gaussian behavior and low bias. The multichannel algorithms lead to less uncertainty in the final dose estimates when the EPSON V800 is employed as reading device. In the case of the EPSON 10000XL, the single-channel algorithms provide less uncertainty in the dose estimates for doses higher than four Gy. A multi-stage model has been presented. With the aid of this model and the use of the Monte-Carlo techniques, the uncertainty of dose estimates for single-channel and multichannel algorithms are estimated. The application of the model together with Monte-Carlo techniques leads to a complete characterization of the uncertainties in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Distributed capillary adiabatic tissue homogeneity model in parametric multi-channel blind AIF estimation using DCE-MRI.

Science.gov (United States)

Kratochvíla, Jiří; Jiřík, Radovan; Bartoš, Michal; Standara, Michal; Starčuk, Zenon; Taxt, Torfinn

2016-03-01

One of the main challenges in quantitative dynamic contrast-enhanced (DCE) MRI is estimation of the arterial input function (AIF). Usually, the signal from a single artery (ignoring contrast dispersion, partial volume effects and flow artifacts) or a population average of such signals (also ignoring variability between patients) is used. Multi-channel blind deconvolution is an alternative approach avoiding most of these problems. The AIF is estimated directly from the measured tracer concentration curves in several tissues. This contribution extends the published methods of multi-channel blind deconvolution by applying a more realistic model of the impulse residue function, the distributed capillary adiabatic tissue homogeneity model (DCATH). In addition, an alternative AIF model is used and several AIF-scaling methods are tested. The proposed method is evaluated on synthetic data with respect to the number of tissue regions and to the signal-to-noise ratio. Evaluation on clinical data (renal cell carcinoma patients before and after the beginning of the treatment) gave consistent results. An initial evaluation on clinical data indicates more reliable and less noise sensitive perfusion parameter estimates. Blind multi-channel deconvolution using the DCATH model might be a method of choice for AIF estimation in a clinical setup. © 2015 Wiley Periodicals, Inc.

Multi-channel time-division integrator in HL-2A

International Nuclear Information System (INIS)

Yan Ji

2008-01-01

HL-2A is China's first Tokamak device with divertor configuration (magnetic confinement controlled nuclear fusion device). To find out the details of on-going fusion reaction at different times is of important significance in achieving controlled nuclear fusion. We developed a new type multi-channel time-division integrator for HL-2A. It has functions of automatic cutting off negative pulse of the input signals, optional integrating time division spacing 0.2-1 ms, TTL starting trigger signal, automatic regularly work 20 s, and integrating 10 channel at the same time. (authors)

On-line gas mixing and multi-channel distribution system

International Nuclear Information System (INIS)

Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.; Joshi, Avinash

2009-01-01

In this presentation, we describe a mass-flow controller based on-line gas mixing unit with the multi-channel distribution system. We highlight different aspects such as requirement, design, calibration, control and operation of this system. This unit has the capability to mix up to four different input gases and distribute over 16 output channels. Output in individual channels is controlled accurately by using capillary-based system. At present, we are using this gas mixing unit for prototype of iron calorimeter (ICAL) detector of India-based Neutrino Observatory (INO).

Models based on multichannel R-matrix theory for evaluating light element reactions

International Nuclear Information System (INIS)

Dodder, D.C.; Hale, G.M.; Nisley, R.A.; Witte, K.; Young, P.G.

1975-01-01

Multichannel R-matrix theory has been used as a basis for models for analysis and evaluation of light nuclear systems. These models have the characteristic that data predictions can be made utilizing information derived from other reactions related to the one of primary interest. Several examples are given where such an approach is valid and appropriate. (auth.)

New start-up channels and multichannel analyzer at the RB reactor; Novi start-up kanali i videkanalni analizator na reaktoru Rb

Energy Technology Data Exchange (ETDEWEB)

Sotic, O; Markovic, H; Vranic, S; Dimitrijevic, Z; Pesic, M [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)

1978-01-15

New start-up channels and a multichannel analyzer were purchased in 1977 for the RB reactor. Both start-up channels contain BF{sub 3} neutron detectors, preamplifier, amplifier, single-channel analyzer, scaler, ratemeter, control unit, recording instrument. This document contains detailed technical description of these devices as well as characteristics of the multichannel analyzer which is being tested and will be used for measuring irradiation in the vicinity of the reactor.

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...

Influence of an Intermediate Option on the Description-Experience Gap and Information Search.

Science.gov (United States)

Sharma, Neha; Debnath, Shoubhik; Dutt, Varun

2018-01-01

Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE) gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people's search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people's search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after information search.

Influence of an Intermediate Option on the Description-Experience Gap and Information Search

Directory of Open Access Journals (Sweden)

Neha Sharma

2018-03-01

Full Text Available Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people’s search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people’s search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after

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.

Advanced Modular, Multi-Channel, High Speed Fiber Optic Sensing System for Acoustic Emissions Monitoring, Phase I

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,...

Hand Motion Classification Using a Multi-Channel Surface Electromyography Sensor

Directory of Open Access Journals (Sweden)

Dong Sun

2012-01-01

Full Text Available The human hand has multiple degrees of freedom (DOF for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

Hand motion classification using a multi-channel surface electromyography sensor.

Science.gov (United States)

Tang, Xueyan; Liu, Yunhui; Lv, Congyi; Sun, Dong

2012-01-01

The human hand has multiple degrees of freedom (DOF) for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG) sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

SU-F-19A-03: Dosimetric Advantages in Critical Structure Dose Sparing by Using a Multichannel Cylinder in High Dose Rate Brachytherapy to Treat Vaginal Cuff Cancer

Energy Technology Data Exchange (ETDEWEB)

Syh, J; Syh, J; Patel, B; Zhang, J; Wu, H; Rosen, L [Willis-Knighton Cancer Center, Shreveport, LA (United States)

2014-06-15

Purpose: The multichannel cylindrical vaginal applicator is a variation of traditional single channel cylindrical vaginal applicator. The multichannel applicator has additional peripheral channels that provide more flexibility in the planning process. The dosimetric advantage is to reduce dose to adjacent organ at risk (OAR) such as bladder and rectum while maintaining target coverage with the dose optimization from additional channels. Methods: Vaginal HDR brachytherapy plans are all CT based. CT images were acquired in 2 mm thickness to keep integrity of cylinder contouring. The CTV of 5mm Rind with prescribed treatment length was reconstructed from 5mm expansion of inserted cylinder. The goal was 95% of CTV covered by 95% of prescribed dose in both single channel planning (SCP)and multichannel planning (MCP) before proceeding any further optimization for dose reduction to critical structures with emphasis on D2cc and V2Gy . Results: This study demonstrated noticeable dose reduction to OAR was apparent in multichannel plans. The D2cc of the rectum and bladder were showing the reduced dose for multichannel versus single channel. The V2Gy of the rectum was 93.72% and 83.79% (p=0.007) for single channel and multichannel respectively (Figure 1 and Table 1). To assure adequate coverage to target while reducing the dose to the OAR without any compromise is the main goal in using multichannel vaginal applicator in HDR brachytherapy. Conclusion: Multichannel plans were optimized using anatomical based inverse optimization algorithm of inverse planning simulation annealing. The optimization solution of the algorithm was to improve the clinical target volume dose coverage while reducing the dose to critical organs such as bladder, rectum and bowels. The comparison between SCP and MCP demonstrated MCP is superior to SCP where the dwell positions were based on geometric array only. It concluded that MCP is preferable and is able to provide certain features superior to SCP.

A computer program integrating a multichannel analyzer with gamma analysis for the estimation of 226 Ra concentration in soil samples

International Nuclear Information System (INIS)

Wilson, J. E.

1992-08-01

A new hardware/software system has been implemented using the existing three-regions-of-interest method for determining the concentration of 226 Ra in soil samples for the Pollutant Assessment Group of the Oak Ridge National Laboratory. Consisting of a personal computer containing a multichannel analyzer, the system utilizes a new program combining the multichannel analyzer with a program analyzing gamma-radiation spectra for 226 Ra concentrations. This program uses a menu interface to minimize and simplify the tasks of system operation

Design of multi-channel amplitude analyzer base on LonWorks

International Nuclear Information System (INIS)

Zhang Ying; Zhao Lihong; Chen Aihua

2008-01-01

The paper introduces the multi-channel analyzer which adopts LonWorks technology. The system detects the pulse peak by hardware circuits and controls data acquisition and network communication by Micro Controller and Unit and Neuron chip. SCM is programmed by Keil C51; the communication between SCM and nerve cell is realized by Neron C language, and the computer program is written by VB language. Test results show that this analyzer is with fast conversion speed and low power consumption. (authors)

Multi-Channel Electronically Scanned Cryogenic Pressure Sensor And Method For Making Same

Science.gov (United States)

Chapman, John J. (Inventor); Hopson, Purnell, Jr. (Inventor); Holloway, Nancy M. (Inventor)

2001-01-01

A miniature, multi-channel, electronically scanned pressure measuring device uses electrostatically bonded silicon dies in a multi-element array. These dies are bonded at specific sites on a glass, pre-patterned substrate. Thermal data is multiplexed and recorded on each individual pressure measuring diaphragm. The device functions in a cryogenic environment without the need of heaters to keep the sensor at constant temperatures.

Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

International Nuclear Information System (INIS)

Jaegers, P.J.; Sanchez, R.G.

1996-01-01

Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

Wireless acquisition of multi-channel seismic data using the Seismobile system

Science.gov (United States)

Isakow, Zbigniew

2017-11-01

This paper describes the wireless acquisition of multi-channel seismic data using a specialized mobile system, Seismobile, designed for subsoil diagnostics for transportation routes. The paper presents examples of multi-channel seismic records obtained during system tests in a configuration with 96 channels (4 landstreamers of 24-channel) and various seismic sources. Seismic waves were generated at the same point using different sources: a 5-kg hammer, a Gisco's source with a 90-kg pile-driver, and two other the pile-drivers of 45 and 70 kg. Particular attention is paid to the synchronization of source timing, the measurement of geometry by autonomous GPS systems, and the repeatability of triggering measurements constrained by an accelerometer identifying the seismic waveform. The tests were designed to the registration, reliability, and range of the wireless transmission of survey signals. The effectiveness of the automatic numbering of measuring modules was tested as the system components were arranged and fixed to the streamers. After measurements were completed, the accuracy and speed of data downloading from the internal memory (SDHC 32GB WiFi) was determined. Additionally, the functionality of automatic battery recharging, the maximum survey duration, and the reliability of battery discharge signalling were assessed.

UNUSUAL TRENDS IN SOLAR P-MODE FREQUENCIES DURING THE CURRENT EXTENDED MINIMUM

International Nuclear Information System (INIS)

Tripathy, S. C.; Jain, K.; Hill, F.; Leibacher, J. W.

2010-01-01

We investigate the behavior of the intermediate-degree mode frequencies of the Sun during the current extended minimum phase to explore the time-varying conditions in the solar interior. Using contemporaneous helioseismic data from the Global Oscillation Network Group (GONG) and the Michelson Doppler Imager (MDI), we find that the changes in resonant mode frequencies during the activity minimum period are significantly greater than the changes in solar activity as measured by different proxies. We detect a seismic minimum in MDI p-mode frequency shifts during 2008 July-August but no such signature is seen in mean shifts computed from GONG frequencies. We also analyze the frequencies of individual oscillation modes from GONG data as a function of latitude and observe a signature of the onset of the solar cycle 24 in early 2009. Thus, the intermediate-degree modes do not confirm the onset of the cycle 24 during late 2007 as reported from the analysis of the low-degree Global Oscillations at Low Frequency frequencies. Further, both the GONG and MDI frequencies show a surprising anti-correlation between frequencies and activity proxies during the current minimum, in contrast to the behavior during the minimum between cycles 22 and 23.

The Use of Continuous Wavelet Transform Based on the Fast Fourier Transform in the Analysis of Multi-channel Electrogastrography Recordings.

Science.gov (United States)

Komorowski, Dariusz; Pietraszek, Stanislaw

2016-01-01

This paper presents the analysis of multi-channel electrogastrographic (EGG) signals using the continuous wavelet transform based on the fast Fourier transform (CWTFT). The EGG analysis was based on the determination of the several signal parameters such as dominant frequency (DF), dominant power (DP) and index of normogastria (NI). The use of continuous wavelet transform (CWT) allows for better visible localization of the frequency components in the analyzed signals, than commonly used short-time Fourier transform (STFT). Such an analysis is possible by means of a variable width window, which corresponds to the scale time of observation (analysis). Wavelet analysis allows using long time windows when we need more precise low-frequency information, and shorter when we need high frequency information. Since the classic CWT transform requires considerable computing power and time, especially while applying it to the analysis of long signals, the authors used the CWT analysis based on the fast Fourier transform (FFT). The CWT was obtained using properties of the circular convolution to improve the speed of calculation. This method allows to obtain results for relatively long records of EGG in a fairly short time, much faster than using the classical methods based on running spectrum analysis (RSA). In this study authors indicate the possibility of a parametric analysis of EGG signals using continuous wavelet transform which is the completely new solution. The results obtained with the described method are shown in the example of an analysis of four-channel EGG recordings, performed for a non-caloric meal.

Multichannel heterodyne radiometers with fast-scanning backward-wave oscillators for ECE measurement on HT-7 tokamak

International Nuclear Information System (INIS)

Zhang, S.Y.; Poznyak, V.I.; Ploskirev, G.; Kalupin, D.; Wan, Y.X.; Xie, J.K.; Luo, J.R.; Li, J.G.; Gao, X.; Wan, B.N.; Zhang, X.D.; Wang, K.J.; Kuang, G.L.

2001-01-01

Two sets of fast-scanning heterodyne radiometer receiver systems employing backward-wave oscillators (BWOs) in 78-118 and 118-178 GHz were developed and installed for electron cyclotron emission (ECE) measurements on HT-7 superconducting tokamak. The double sideband (DSB) radiometer in 78-118 GHz measures 16 ECE frequency points with a scanning time period of 0.65 ms. The other radiometer in 118-178 GHz consists of one independent channel of DSB heterodyne receiver with intermediate frequency (IF) of 100-500 MHz and two channels of single sideband (SSB) heterodyne receiver that are sensitive to upper sideband and lower sideband individually; the IF frequency of the SSB channels are 1.5 GHz around the local oscillator frequencies with 1 GHz bandwidth. By employing a novel design, this unique radiometer measures 3 ECE frequency points at each of the 16 local oscillator frequency points in 118-178 GHz, and the full band can be swept in 0.65 ms period, thus the radiometer measures 48 ECE frequency points in 0.65 ms in principle. Each of the local oscillators' frequency points can be preset by program to meet specific physics interests. Horizontal view of ECE was installed to measure electron temperature profiles; vertically viewing optics along a perpendicular chord was also installed to study nonthermal ECE spectra. Preliminary measurement results were presented during ohmic and pellet injection plasmas

A high-performance data acquisition system for computer-based multichannel analyzer

International Nuclear Information System (INIS)

Zhou Xinzhi; Bai Rongsheng; Wen Liangbi; Huang Yanwen

1996-01-01

A high-performance data acquisition system applied in the multichannel analyzer is designed with single-chip microcomputer system. The paper proposes the principle and the method of realizing the simultaneous data acquisition, the data pre-processing, and the fast bidirectional data transfer by means of direct memory access based on dual-port RAM as well. The measurement for dead or live time of ADC system can also be implemented efficiently by using it

Nonrelativistic multichannel quantum scattering theory in a two Hilbert space formulation

International Nuclear Information System (INIS)

Chandler, C.

1977-08-01

A two-Hilbert-space form of an abstract scattering theory specifically applicable to multichannel quantum scattering problems is outlined. General physical foundations of the theory are reviewed. Further topics discussed include the invariance principle, asymptotic completeness of the wave operators, representations of the scattering operator in terms of transition operators and fundamental equations that these transition operators satisfy. Outstanding problems, including the difficulties of including Coulomb interactions in the theory, are pointed out. (D.P.)

Take time to make time : What to consider when managing multi-channel sales systems with the objective to increase sales efficiency

OpenAIRE

ALM, RAGNAR; KYRÖNLAHTI, RUDY

2016-01-01

Traditional sales systems have been disrupted by technological developments. In order to  adapt, companies are changing the way they interact with their customers in business-to-business markets. In the last three decades, multi-channel strategies have spurred the proliferation of different sales channels and new ways of managing sales systems. The purpose of this research was to investigate what should be considered when managing multi-channel sales systems with the objective of increasing s...

Multichannel Selective Femtosecond Coherent Control Based on Symmetry Properties

International Nuclear Information System (INIS)

Amitay, Zohar; Gandman, Andrey; Chuntonov, Lev; Rybak, Leonid

2008-01-01

We present and implement a new scheme for extended multichannel selective femtosecond coherent control based on symmetry properties of the excitation channels. Here, an atomic nonresonant two-photon absorption channel is coherently incorporated in a resonance-mediated (2+1) three-photon absorption channel. By proper pulse shaping, utilizing the invariance of the two-photon absorption to specific phase transformations of the pulse, the three-photon absorption is tuned independently over an order-of-magnitude yield range for any possible two-photon absorption yield. Noticeable is a set of ''two-photon dark pulses'' inducing widely tunable three-photon absorption

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.

Multichannel long period seismic data acquisition system

International Nuclear Information System (INIS)

Kolvankar, V.G.; Rao, D.S.

1990-01-01

This paper discusses the specifications and performance of an eight channel long period seismic digital data acquisition system, which is developed and installed at Seismic Array Station, Gauribidanur, Karnataka State. The paper describes how these data in an unedited form are recorded on a single track of magnetic tape inter-mittantly, which has resulted in recording of 50 days data on a single tapespool. A time indexing technique which enables quick access to any desired portion of a recorded tape is also discussed. Typical examples of long period seismic event signals recorded by this system are also illustrated. Various advantages, the system provides over the analog multichannel instrumentation tape recording system, operating at Seismic Array Station for th e last two decades, are also discussed. (author). 7 figs

A cryogenic multichannel electronically scanned pressure module

Science.gov (United States)

Shams, Qamar A.; Fox, Robert L.; Adcock, Edward E.; Kahng, Seun K.

1992-01-01

Consideration is given to a cryogenic multichannel electronically scanned pressure (ESP) module developed and tested over an extended temperature span from -184 to +50 C and a pressure range of 0 to 5 psig. The ESP module consists of 32 pressure sensor dice, four analog 8 differential-input multiplexers, and an amplifier circuit, all of which are packaged in a physical volume of 2 x 1 x 5/8 in with 32 pressure and two reference ports. Maximum nonrepeatability is measured at 0.21 percent of full-scale output. The ESP modules have performed consistently well over 15 times over the above temperature range and continue to work without any sign of degradation. These sensors are also immune to repeated thermal shock tests over a temperature change of 220 C/sec.

Assembly language program design used in model DD80 multifunction microcomputer multichannel analyzer

Energy Technology Data Exchange (ETDEWEB)

Yiziang, Wei; Ying, Chen; Xide, Zhao

1985-05-01

This paper describes the structures, features, flowcharts and design considerations of assembly language program used in Model DD80 (FH1920) multifunction microcomputer multichannel analyzer. On the Model TRS-80 (I) microcomputer with DD80 multifunction interface this program can be used in spectrum data acquisition, spectrum live display and some spectrum data processing.

A Combined Methodology to Eliminate Artifacts in Multichannel Electrogastrogram Based on Independent Component Analysis and Ensemble Empirical Mode Decomposition.

Science.gov (United States)

Sengottuvel, S; Khan, Pathan Fayaz; Mariyappa, N; Patel, Rajesh; Saipriya, S; Gireesan, K

2018-06-01

Cutaneous measurements of electrogastrogram (EGG) signals are heavily contaminated by artifacts due to cardiac activity, breathing, motion artifacts, and electrode drifts whose effective elimination remains an open problem. A common methodology is proposed by combining independent component analysis (ICA) and ensemble empirical mode decomposition (EEMD) to denoise gastric slow-wave signals in multichannel EGG data. Sixteen electrodes are fixed over the upper abdomen to measure the EGG signals under three gastric conditions, namely, preprandial, postprandial immediately, and postprandial 2 h after food for three healthy subjects and a subject with a gastric disorder. Instantaneous frequencies of intrinsic mode functions that are obtained by applying the EEMD technique are analyzed to individually identify and remove each of the artifacts. A critical investigation on the proposed ICA-EEMD method reveals its ability to provide a higher attenuation of artifacts and lower distortion than those obtained by the ICA-EMD method and conventional techniques, like bandpass and adaptive filtering. Characteristic changes in the slow-wave frequencies across the three gastric conditions could be determined from the denoised signals for all the cases. The results therefore encourage the use of the EEMD-based technique for denoising gastric signals to be used in clinical practice.

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.

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.

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

2015-01-01

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. PMID:26287193

Harnessing mode-selective nonlinear optics for on-chip multi-channel all-optical signal processing

Directory of Open Access Journals (Sweden)

Ming Ma

2016-11-01

Full Text Available All-optical signal processing based on nonlinear optical effects allows for the realization of important functions in telecommunications including wavelength conversion, optical multiplexing/demultiplexing, Fourier transformation, and regeneration, amongst others, on ultrafast time scales to support high data rate transmission. In integrated photonic subsystems, the majority of all-optical signal processing systems demonstrated to date typically process only a single channel at a time or perform a single processing function, which imposes a serious limitation on the functionality of integrated solutions. Here, we demonstrate how nonlinear optical effects can be harnessed in a mode-selective manner to perform simultaneous multi-channel (two and multi-functional optical signal processing (i.e., regenerative wavelength conversion in an integrated silicon photonic device. This approach, which can be scaled to a higher number of channels, opens up a new degree of freedom for performing a broad range of multi-channel nonlinear optical signal processing functions using a single integrated photonic device.

Synchrotron radiation and multichannel detectors in structural analysis

Energy Technology Data Exchange (ETDEWEB)

Mokulskii, M

1979-10-01

A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO/sub 2/ as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels.

Synchrotron radiation and multichannel detectors in structural analysis

International Nuclear Information System (INIS)

Mokulskij, M.

1979-01-01

A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO 2 as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels. (J.B.)

Enhancement of intermediate-field two-photon absorption by rationally shaped femtosecond pulses

International Nuclear Information System (INIS)

Chuntonov, Lev; Rybak, Leonid; Gandman, Andrey; Amitay, Zohar

2008-01-01

We extend the powerful frequency-domain analysis of femtosecond two-photon absorption to the intermediate-field regime of considerable absorption yields, where additionally to the weak-field nonresonant two-photon transitions also four-photon transitions play a role. Consequently, we rationally find that the absorption is enhanced over the transform-limited pulse by any shaped pulse having a spectral phase that is antisymmetric around one-half of the transition frequency and a spectrum that is asymmetric around it (red or blue detuned according to the system). The enhancement increases as the field strength increases. The theoretical results for Na are verified experimentally

Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis

Science.gov (United States)

Dai, Chenkai; Fridman, Gene Y.; Chiang, Bryce; Davidovics, Natan; Melvin, Thuy-Anh; Cullen, Kathleen E.; Della Santina, Charles C.

2012-01-01

By sensing three-dimensional (3D) head rotation and electrically stimulating the three ampullary branches of a vestibular nerve to encode head angular velocity, a multichannel vestibular prosthesis (MVP) can restore vestibular sensation to individuals disabled by loss of vestibular hair cell function. However, current spread to afferent fibers innervating non-targeted canals and otolith endorgans can distort the vestibular nerve activation pattern, causing misalignment between the perceived and actual axis of head rotation. We hypothesized that over time, central neural mechanisms can adapt to correct this misalignment. To test this, we rendered five chinchillas vestibular-deficient via bilateral gentamicin treatment and unilaterally implanted them with a head mounted MVP. Comparison of 3D angular vestibulo-ocular reflex (aVOR) responses during 2 Hz, 50°/s peak horizontal sinusoidal head rotations in darkness on the first, third and seventh days of continual MVP use revealed that eye responses about the intended axis remained stable (at about 70% of the normal gain) while misalignment improved significantly by the end of one week of prosthetic stimulation. A comparable time course of improvement was also observed for head rotations about the other two semicircular canal axes and at every stimulus frequency examined (0.2–5 Hz). In addition, the extent of disconjugacy between the two eyes progressively improved during the same time window. These results indicate that the central nervous system rapidly adapts to multichannel prosthetic vestibular stimulation to markedly improve 3D aVOR alignment within the first week after activation. Similar adaptive improvements are likely to occur in other species, including humans. PMID:21374081

A Versatile Multichannel Digital Signal Processing Module for Microcalorimeter Arrays

Science.gov (United States)

Tan, H.; Collins, J. W.; Walby, M.; Hennig, W.; Warburton, W. K.; Grudberg, P.

2012-06-01

Different techniques have been developed for reading out microcalorimeter sensor arrays: individual outputs for small arrays, and time-division or frequency-division or code-division multiplexing for large arrays. Typically, raw waveform data are first read out from the arrays using one of these techniques and then stored on computer hard drives for offline optimum filtering, leading not only to requirements for large storage space but also limitations on achievable count rate. Thus, a read-out module that is capable of processing microcalorimeter signals in real time will be highly desirable. We have developed multichannel digital signal processing electronics that are capable of on-board, real time processing of microcalorimeter sensor signals from multiplexed or individual pixel arrays. It is a 3U PXI module consisting of a standardized core processor board and a set of daughter boards. Each daughter board is designed to interface a specific type of microcalorimeter array to the core processor. The combination of the standardized core plus this set of easily designed and modified daughter boards results in a versatile data acquisition module that not only can easily expand to future detector systems, but is also low cost. In this paper, we first present the core processor/daughter board architecture, and then report the performance of an 8-channel daughter board, which digitizes individual pixel outputs at 1 MSPS with 16-bit precision. We will also introduce a time-division multiplexing type daughter board, which takes in time-division multiplexing signals through fiber-optic cables and then processes the digital signals to generate energy spectra in real time.

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.

A fast multichannel analog storage system

International Nuclear Information System (INIS)

Freytag, D.R.

1983-01-01

A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. =11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

Interfacing multichannel analyzers, counter, Modems and TTY:s with the PDP-15 computer

International Nuclear Information System (INIS)

Kozyczkowski, J.J.

1975-01-01

In nuclear physics laboratories as well as in others there exist strong needs of relatively fast but cost-economical transfers of stored data from available units into a computer. Here the advantage of asynchronous transceivers is utilized. The read in of 1024 channels from a Multichannel Analyzer can take place in 16 seconds in favourable circumstances. (Auth.)

Multichannel and Multispectral Image Restoration Employing Fuzzy Theory and Directional Techniques

OpenAIRE

Rosales, Alberto; Ponomaryov, Volodymyr

2009-01-01

It has designed a novel structure of robust framework to remove impulse noise and additive noise in images and multichannel video sequences. Unlike existed techniques, the designed approach employs fuzzy and directional techniques to estimate motion and noise in the past and present frames showing good results. The designed fuzzy rules characterize the presence of motion and noise between the pixels in two frames (past and present frames). It has been demonstrated that the combined use of gra...

A multi-channel humidity control system based on LabVIEW

International Nuclear Information System (INIS)

Zhang Aiwu; Xie Yuguang; Liu Hongbang; Liu Yingbiao; Cai Xiao; Yu Boxiang; Lu Junguang; Zhou Li

2011-01-01

A real time multi-channel humidity control system was designed based on LabVIEW, using the dry air branch of BESⅢ drying system. The hardware of this control system consist of mini humidity and temperature sensors, intelligent collection module, switch quantity controller and electromagnetic valves. The humidity can be controlled at arbitrary value from air humidity to 3% with accuracy better than 2%. Multi microenvironment with different humidity can be easily controlled and monitored in real time by this system. It can also be extended to hybrid control of multi channel humidity and temperature. (authors)

The experimental research of a field-enhanced multichannel oil switch

International Nuclear Information System (INIS)

Zhao, R.; Zeng, N.; Yang, D.; Jiang, X.; Wang, X.

1993-01-01

This paper describes the performance of a field enhanced multichannel oil switch which is used as the main switch of HEAVEN-LIGHT II intense pulsed electron beam accelerator at CIAE. The switch experiments have been carried out with different inductance of the solenoid inductor in series with a self-closing axial gap and position and diameter of the trigger disc. The experiments using water as a breakdown medium of the switch have been done to compare with oil switch. These experimental results and conclusions are presented in the paper

Multichannel microwave interferometer with an antenna switching system for electron density measurement in a laboratory plasma experiment

Energy Technology Data Exchange (ETDEWEB)

Kawamori, Eiichirou; Lin, Yu-Hsiang [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Mase, Atsushi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580 (Japan); Nishida, Yasushi; Cheng, C. Z. [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Plasma and Space Science Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

2014-02-15

This study presents a simple and powerful technique for multichannel measurements of the density profile in laboratory plasmas by microwave interferometry. This technique uses electromechanical microwave switches to temporally switch the connection between multiple receiver antennas and one phase-detection circuit. Using this method, the phase information detected at different positions is rearranged into a time series that can be acquired from a minimum number of data acquisition channels (e.g., two channels in the case of quadrature detection). Our successfully developed multichannel microwave interferometer that uses the antenna switching method was applied to measure the radial electron density profiles in a magnetized plasma experiment. The advantage of the proposed method is its compactness and scalability to multidimensional measurement systems at low cost.

Multichannel analyzer with real-time correction of counting losses based on a fast 16/32 bit microprocessor

International Nuclear Information System (INIS)

Westphal, G.P.; Kasa, T.

1984-01-01

It is demonstrated that from a modern microprocessor with 32 bit architecture and from standard VLSI peripheral chips a multichannel analyzer with real-time correction of counting losses may be designed in a very flexible yet cost-effective manner. Throughput rates of 100,000 events/second are a good match even for high-rate spectroscopy systems and may be further enhanced by the use of already available CPU chips with higher clock frequency. Low power consumption and a very compact form factor make the design highly recommendable for portable applications. By means of a simple and easily reproducible rotating sample device the dynamic response of the VPG counting loss correction method have been tested and found to be more than sufficient for conceivable real-time applications. Enhanced statistical accuracy of correction factors may be traded against speed of response by the mere change of one preset value which lends itself to the simple implementation of self-adapting systems. Reliability as well as user convenience is improved by self-calibration of pulse evolution time in the VPG counting loss correction unit

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

2017-08-01

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.

Evaluation of K x-ray escape and crosstalk in CdTe detectors and multi-channel detectors

International Nuclear Information System (INIS)

Ohtsuchi, Tetsuro; Ohmori, Koichi; Tsutsui, Hiroshi; Baba, Sueki

1995-01-01

The simple structure of CdTe semiconductor detectors facilitates their downsizing, and their possible application to radiographic sensors has been studied. The escape of K X-rays from these detectors increases with reduction of their dimensions and affects the measurements of X- and gamma-ray spectra. K X-rays also produce crosstalk in multi-channel detectors with adjacent channels. Therefore, K X-rays which escape from the detector elements degrade both the precision of energy spectra and spatial resolution. The ratios of escape peak integrated counts to total photon counts for various sizes of CdTe single detectors were calculated for gamma rays using the Monte Carlo method. Also, escape and crosstalk ratios were simulated for the CdTe multi-channel detectors. The theoretical results were tested experimentally for 59.54-keV gamma rays from a 241 Am radioactive source. Results showed that escape ratios for single detectors were strongly dependent on element size and thickness. The escape and crosstalk ratios increased with closer channel pitch. The calculated results showed a good agreement with the experimental data. The calculations made it clear that K X-rays which escaped to neighboring channels induced crosstalk more frequently at smaller channel pitch in multichannel detectors. A radiation shielding grid which blocked incident photons between the boundary channels was also tested by experiment and by calculation. It was effective in reducing the probability of escape and crosstalk

Joint entropy for space and spatial frequency domains estimated from psychometric functions of achromatic discrimination.

Science.gov (United States)

Silveira, Vladímir de Aquino; Souza, Givago da Silva; Gomes, Bruno Duarte; Rodrigues, Anderson Raiol; Silveira, Luiz Carlos de Lima

2014-01-01

We used psychometric functions to estimate the joint entropy for space discrimination and spatial frequency discrimination. Space discrimination was taken as discrimination of spatial extent. Seven subjects were tested. Gábor functions comprising unidimensionalsinusoidal gratings (0.4, 2, and 10 cpd) and bidimensionalGaussian envelopes (1°) were used as reference stimuli. The experiment comprised the comparison between reference and test stimulithat differed in grating's spatial frequency or envelope's standard deviation. We tested 21 different envelope's standard deviations around the reference standard deviation to study spatial extent discrimination and 19 different grating's spatial frequencies around the reference spatial frequency to study spatial frequency discrimination. Two series of psychometric functions were obtained for 2%, 5%, 10%, and 100% stimulus contrast. The psychometric function data points for spatial extent discrimination or spatial frequency discrimination were fitted with Gaussian functions using the least square method, and the spatial extent and spatial frequency entropies were estimated from the standard deviation of these Gaussian functions. Then, joint entropy was obtained by multiplying the square root of space extent entropy times the spatial frequency entropy. We compared our results to the theoretical minimum for unidimensional Gábor functions, 1/4π or 0.0796. At low and intermediate spatial frequencies and high contrasts, joint entropy reached levels below the theoretical minimum, suggesting non-linear interactions between two or more visual mechanisms. We concluded that non-linear interactions of visual pathways, such as the M and P pathways, could explain joint entropy values below the theoretical minimum at low and intermediate spatial frequencies and high contrasts. These non-linear interactions might be at work at intermediate and high contrasts at all spatial frequencies once there was a substantial decrease in joint

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

Intermediality and media change

OpenAIRE

2012-01-01

This book is about intermediality as an approach to analysing and understanding media change. Intermediality and Media Change is critical of technological determinism that characterises 'new media discourse' about the ongoing digitalization, framed as a revolution and creating sharp contrasts between old and new media. Intermediality instead emphasises paying attention to continuities between media of all types and privileges a comparative perspective on technological changes in media over ti...

Acoustic Event Detection in Multichannel Audio Using Gated Recurrent Neural Networks with High‐Resolution Spectral Features

Directory of Open Access Journals (Sweden)

Hyoung‐Gook Kim

2017-12-01

Full Text Available Recently, deep recurrent neural networks have achieved great success in various machine learning tasks, and have also been applied for sound event detection. The detection of temporally overlapping sound events in realistic environments is much more challenging than in monophonic detection problems. In this paper, we present an approach to improve the accuracy of polyphonic sound event detection in multichannel audio based on gated recurrent neural networks in combination with auditory spectral features. In the proposed method, human hearing perception‐based spatial and spectral‐domain noise‐reduced harmonic features are extracted from multichannel audio and used as high‐resolution spectral inputs to train gated recurrent neural networks. This provides a fast and stable convergence rate compared to long short‐term memory recurrent neural networks. Our evaluation reveals that the proposed method outperforms the conventional approaches.

Aberrant intermediate filament and synaptophysin expression is a frequent event in malignant melanoma: an immunohistochemical study of 73 cases.

Science.gov (United States)

Romano, Ryan C; Carter, Jodi M; Folpe, Andrew L

2015-08-01

Malignant melanomas are known to express vimentin, among other intermediate filaments. Though anomalous keratin expression by malignant melanoma has been reported, its frequency is not well-established and this phenomenon is not well-known. We have seen in consultation a number of malignant melanomas with anomalous expression of keratin, other intermediate filaments, or synaptophysin, and therefore studied a large group of primary and metastatic melanomas to determine the frequency of these events. About 73 cases of malignant melanoma (22 primaries and 51 metastases) from 71 patients (51 male, 20 female; mean 59 years, range 17-87 years) were retrieved from our archives. Prior diagnoses were confirmed by re-review of hematoxylin and eosin sections and relevant (e.g., S100 protein, HMB45, Melan-A, and tyrosinase) immunohistochemical studies. Available sections were immunostained for keratin (OSCAR and AE1/AE3 antibodies), desmin, neurofilament protein, glial fibrillary acidic protein, synaptophysin, and chromogranin A. Not all cases could be tested for all markers. Cases were predominantly epithelioid (48/73, 66%) or spindle cell/desmoplastic (25/73, 34%). S100 protein, Melan-A, HMB45, and tyrosinase were positive in 60/65 (92%), 34/64 (53%), 30/60 (50%), 25/48 (52%) of cases, respectively. All five S100-protein-negative cases expressed at least one of the other melanocytic markers: Melan-A (two of four, 50%), HMB45 (two of three, 67%), and tyrosinase (one of two, 50%). All cases expressed at least one melanocytic marker. Cases were positive for keratin (OSCAR, 17/61, 28%; AE1/AE3, 16/40, 40%), desmin (11/47, 24%), neurofilament protein (5/31, 16%), glial fibrillary acidic protein (3/32, 9%), and synaptophysin (10/34, 29%), typically only in a minority of cells. Chromogranin was negative (0/32, 0%). Altogether 9/73 cases (12%) showed expression of >1 intermediate filament. All S100-protein-negative melanomas showed anomalous intermediate filament expression (keratin

Multi-channel and porous SiO@N-doped C rods as anodes for high-performance lithium-ion batteries

Science.gov (United States)

Huang, Xiao; Li, Mingqi

2018-05-01

To improve the cycling stability and rate capability of SiO electrodes, multi-channel and porous SiO@N-doped C (mp-SiO@N-doped C) rods are fabricated by the combination of electrospinning and heat treatment with the assistance of poly(methyl methacrylate) (PMMA). During annealing, in-situ PMMA degradation and gasification lead to the formation of multi-channel structure and more pores. As anodes for lithium ion batteries, the mp-SiO@N-doped C rods exhibit excellent cycling stability. At a current density of 400 mA g-1, a discharge capacity of 806 mAh g-1 can be kept after 250 cycles, the retention of which is over than 100% versus the initial reversible capacity. Compared with the SiO@N-doped C rods synthesized without the help of PMMA, the mp-SiO@N-doped C rods exhibit more excellent rate capability. The excellent electrochemical performance is attributed to the special structure of the mp-SiO@N-doped C rods. In addition to the conductivity improved by carbon fibers, the multi-channel and porous structures not only make ions/electrons transfer and electrolyte diffusion easier, but also contribute to the structural stability of the electrodes.

Altered Frequency Distribution in the Electroencephalogram is Correlated to the Analgesic Effect of Remifentanil

DEFF Research Database (Denmark)

Graversen, Carina; Malver, Lasse P; Kurita, Geana P

2015-01-01

Opioids alter resting state brain oscillations by multiple and complex factors, which are still to be elucidated. To increase our knowledge, multi-channel electroencephalography (EEG) was subjected to multivariate pattern analysis (MVPA), to identify the most descriptive frequency bands and scalp...... distributions were extracted by a continuous wavelet transform and normalized into delta, theta, alpha, beta and gamma bands. Alterations relative to pre-treatment responses were calculated for all channels and used as input to the MVPA. Compared to placebo, remifentanil increased the delta band and decreased...... the theta and alpha band oscillations as a mean over all channels (all p ≤ 0.007). The most discriminative channels in these frequency bands were F1 in delta (83.33%, p = 0.0023) and theta bands (95.24%, p band (80.95%, p = 0.0054). These alterations were correlated...

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...

Multichannel Recorder for Low Frequency Signals: Application of Oscilloscope as Integrated Mobile Service for a Smartphone

Directory of Open Access Journals (Sweden)

Michal Kochlan

2016-01-01

Full Text Available Data acquisition and processing are well known for some time. Many applications use powerful hardware to acquire, process, and visualize signal waveforms. But there are some applications that do not have to perform high resolution signal acquisition and process large amount of data, for example, low frequency applications of embedded design and applications for remote power grid monitoring. The paper describes special system for low frequency signal data sample acquisition, processing, and visualization implemented as a service on Android-based smart device. The service makes smart device functioning as an oscilloscope or arbitrary waveform generator which is accessible remotely through Bluetooth. The design respects low power consumption requirements, simplicity, and user friendliness in application design. Application scenario was implemented as wireless data acquisition system for power grid monitoring.

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.

Intermediate Fragment

DEFF Research Database (Denmark)

Kruse Aagaard, Anders

2015-01-01

This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

Compact multichannel high-resolution micro-electro-mechanical systems-based interrogator for Fiber Bragg grating sensing

DEFF Research Database (Denmark)

Ganziy, Denis; Rose, Bjarke; Bang, Ole

2017-01-01

We propose a novel type of compact high-resolution multichannel micro-electro-mechanical systems (MEMS)-based interrogator, where we replace the linear detector with a digital micromirror device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used...

A real-time multichannel memory controller and optimal mapping of memory clients to memory channels

NARCIS (Netherlands)

Gomony, M.D.; Akesson, K.B.; Goossens, K.G.W.

2015-01-01

Ever-increasing demands for main memory bandwidth and memory speed/power tradeoff led to the introduction of memories with multiple memory channels, such as Wide IO DRAM. Efficient utilization of a multichannel memory as a shared resource in multiprocessor real-time systems depends on mapping of the

Governance-Default Risk Relationship and the Demand for Intermediated and Non-Intermediated Debt

Directory of Open Access Journals (Sweden)

Husam Aldamen

2012-09-01

Full Text Available This paper explores the impact of corporate governance on the demand for intermediated debt (asset finance, bank debt, non-bank private debt and non-intermediated debt (public debt in the Australian debt market. Relative to other countries the Australian debt market is characterised by higher proportions of intermediated or private debt with a lower inherent level of information asymmetry in that private lenders have greater access to financial information (Gray, Koh & Tong 2009. Our firm level, cross-sectional evidence suggests that higher corporate governance impacts demand for debt via the mitigation of default risk. However, this relationship is not uniform across all debt types. Intermediated debt such as bank and asset finance debt are more responsive to changes in governance-default risk relationship than non-bank and non-intermediated debt. The implication is that a firm’s demand for different debt types will reflect its governance-default risk profile.

Multichannel noninvasive human-machine interface via stretchable µm thick sEMG patches for robot manipulation

Science.gov (United States)

Zhou, Ying; Wang, Youhua; Liu, Runfeng; Xiao, Lin; Zhang, Qin; Huang, YongAn

2018-01-01

Epidermal electronics (e-skin) emerging in recent years offer the opportunity to noninvasively and wearably extract biosignals from human bodies. The conventional processes of e-skin based on standard microelectronic fabrication processes and a variety of transfer printing methods, nevertheless, unquestionably constrains the size of the devices, posing a serious challenge to collecting signals via skin, the largest organ in the human body. Herein we propose a multichannel noninvasive human-machine interface (HMI) using stretchable surface electromyography (sEMG) patches to realize a robot hand mimicking human gestures. Time-efficient processes are first developed to manufacture µm thick large-scale stretchable devices. With micron thickness, the stretchable µm thick sEMG patches show excellent conformability with human skin and consequently comparable electrical performance with conventional gel electrodes. Combined with the large-scale size, the multichannel noninvasive HMI via stretchable µm thick sEMG patches successfully manipulates the robot hand with eight different gestures, whose precision is as high as conventional gel electrodes array.

Multiplex multivariate recurrence network from multi-channel signals for revealing oil-water spatial flow behavior.

Science.gov (United States)

Gao, Zhong-Ke; Dang, Wei-Dong; Yang, Yu-Xuan; Cai, Qing

2017-03-01

The exploration of the spatial dynamical flow behaviors of oil-water flows has attracted increasing interests on account of its challenging complexity and great significance. We first technically design a double-layer distributed-sector conductance sensor and systematically carry out oil-water flow experiments to capture the spatial flow information. Based on the well-established recurrence network theory, we develop a novel multiplex multivariate recurrence network (MMRN) to fully and comprehensively fuse our double-layer multi-channel signals. Then we derive the projection networks from the inferred MMRNs and exploit the average clustering coefficient and the spectral radius to quantitatively characterize the nonlinear recurrent behaviors related to the distinct flow patterns. We find that these two network measures are very sensitive to the change of flow states and the distributions of network measures enable to uncover the spatial dynamical flow behaviors underlying different oil-water flow patterns. Our method paves the way for efficiently analyzing multi-channel signals from multi-layer sensor measurement system.

Synthesis of Gold Nanoparticles to Capture Lifelike Proteins: Application on the Multichannel Sensor Array Design

Directory of Open Access Journals (Sweden)

Yumin Leng

2018-01-01

Full Text Available The chemical elements of proteins are similar to that of DNA (e.g., C, H, O, and N, and DNA shows different knotted architectures. So we imagine that proteins may show a wealth of highly complex structures, especially when proteins interact with each other. The imagination was proved by synthesizing gold nanoparticles (GNPs to capture the lifelike protein structures. The optical responses (i.e., color of as-prepared GNPs are found to be characteristic to a given protein (or heavy metal ion. Based on the “three colors” principle of Thomas Young, we extracted the red, green, and blue (RGB alterations of as-synthesized GNPs to fabricate multichannel sensor arrays for proteins (or heavy metal ions discrimination. The designed multichannel sensor arrays demonstrate possibilities in semiquantitative analysis of multiple analytes (e.g., proteins and heavy metal ions. This work is believed to open new opportunities for GNPs-based label-free sensing.

An integrated system for dynamic control of auditory perspective in a multichannel sound field

Science.gov (United States)

Corey, Jason Andrew

An integrated system providing dynamic control of sound source azimuth, distance and proximity to a room boundary within a simulated acoustic space is proposed for use in multichannel music and film sound production. The system has been investigated, implemented, and psychoacoustically tested within the ITU-R BS.775 recommended five-channel (3/2) loudspeaker layout. The work brings together physical and perceptual models of room simulation to allow dynamic placement of virtual sound sources at any location of a simulated space within the horizontal plane. The control system incorporates a number of modules including simulated room modes, "fuzzy" sources, and tracking early reflections, whose parameters are dynamically changed according to sound source location within the simulated space. The control functions of the basic elements, derived from theories of perception of a source in a real room, have been carefully tuned to provide efficient, effective, and intuitive control of a sound source's perceived location. Seven formal listening tests were conducted to evaluate the effectiveness of the algorithm design choices. The tests evaluated: (1) loudness calibration of multichannel sound images; (2) the effectiveness of distance control; (3) the resolution of distance control provided by the system; (4) the effectiveness of the proposed system when compared to a commercially available multichannel room simulation system in terms of control of source distance and proximity to a room boundary; (5) the role of tracking early reflection patterns on the perception of sound source distance; (6) the role of tracking early reflection patterns on the perception of lateral phantom images. The listening tests confirm the effectiveness of the system for control of perceived sound source distance, proximity to room boundaries, and azimuth, through fine, dynamic adjustment of parameters according to source location. All of the parameters are grouped and controlled together to

Technical Note: Statistical dependences between channels in radiochromic film readings. Implications in multichannel dosimetry

Energy Technology Data Exchange (ETDEWEB)

González-López, Antonio, E-mail: antonio.gonzalez7@carm.es [Hospital Clínico Universitario Virgen de la Arrixaca, Ctra. Madrid-Cartagena, El Palmar, Murcia 30120 (Spain); Vera-Sánchez, Juan Antonio [Servicio de Protección Radiológica y Física Médica Hospital Universitari Sant Joan de Reus, Av. del Dr. Josep Laporte, 2, Reus, Tarragona 43204 (Spain); Ruiz-Morales, Carmen [Hospital IMED Elche, Max Planck No. 3, Elche, Alicante 03203 (Spain)

2016-05-15

Purpose: This note studies the statistical relationships between color channels in radiochromic film readings with flatbed scanners. The same relationships are studied for noise. Finally, their implications for multichannel film dosimetry are discussed. Methods: Radiochromic films exposed to wedged fields of 6 MV energy were read in a flatbed scanner. The joint histograms of pairs of color channels were used to obtain the joint and conditional probability density functions between channels. Then, the conditional expectations and variances of one channel given another channel were obtained. Noise was extracted from film readings by means of a multiresolution analysis. Two different dose ranges were analyzed, the first one ranging from 112 to 473 cGy and the second one from 52 to 1290 cGy. Results: For the smallest dose range, the conditional expectations of one channel given another channel can be approximated by linear functions, while the conditional variances are fairly constant. The slopes of the linear relationships between channels can be used to simplify the expression that estimates the dose by means of the multichannel method. The slopes of the linear relationships between each channel and the red one can also be interpreted as weights in the final contribution to dose estimation. However, for the largest dose range, the conditional expectations of one channel given another channel are no longer linear functions. Finally, noises in different channels were found to correlate weakly. Conclusions: Signals present in different channels of radiochromic film readings show a strong statistical dependence. By contrast, noise correlates weakly between channels. For the smallest dose range analyzed, the linear behavior between the conditional expectation of one channel given another channel can be used to simplify calculations in multichannel film dosimetry.

Multichannel all–optical switch based on a thin slab of resonant two–level emitters

Directory of Open Access Journals (Sweden)

Malikov Ramil

2017-01-01

Full Text Available We discuss the possibility of using a thin layer of inhomogeneously broadened resonant emitters as a multichannel all–optical switch. Switching time from the lower stable branch of the system's bistable characteristics to the upper one and vice versa, which determines the speed of operation of a bistable device, is studied.

The assembly language program design used in model DD80 multifunction microcomputer multichannel analyzer

International Nuclear Information System (INIS)

Wei Yiziang; Chen Ying; Zhao Xide

1985-01-01

This paper describes the structures, features, flowcharts and design considerations of assembly language program used in Model DD80 (FH1920) multifunction microcomputer multichannel analyzer. On the Model TRS-80 (I) microcomputer with DD80 multifunction interface this program can be used in spectrum data acquisition, spectrum live display and some spectrum data processing

An Efficient and QoS Supported Multichannel MAC Protocol for Vehicular Ad Hoc Networks.

Science.gov (United States)

Song, Caixia; Tan, Guozhen; Yu, Chao

2017-10-09

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety (transport efficiency and infotainment) applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. Different types of applications require different levels Quality-of-Service (QoS) support. Recently, transport efficiency and infotainment applications (e.g., electronic map download and Internet access) have received more and more attention, and this kind of applications is expected to become a big market driver in a near future. In this paper, we propose an Efficient and QoS supported Multichannel Medium Access Control (EQM-MAC) protocol for VANETs in a highway environment. The EQM-MAC protocol utilizes the service channel resources for non-safety message transmissions during the whole synchronization interval, and it dynamically adjusts minimum contention window size for different non-safety services according to the traffic conditions. Theoretical model analysis and extensive simulation results show that the EQM-MAC protocol can support QoS services, while ensuring the high saturation throughput and low transmission delay for non-safety applications.

An Efficient and QoS Supported Multichannel MAC Protocol for Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Caixia Song

2017-10-01

Full Text Available Vehicular Ad Hoc Networks (VANETs employ multichannel to provide a variety of safety and non-safety (transport efficiency and infotainment applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. Different types of applications require different levels Quality-of-Service (QoS support. Recently, transport efficiency and infotainment applications (e.g., electronic map download and Internet access have received more and more attention, and this kind of applications is expected to become a big market driver in a near future. In this paper, we propose an Efficient and QoS supported Multichannel Medium Access Control (EQM-MAC protocol for VANETs in a highway environment. The EQM-MAC protocol utilizes the service channel resources for non-safety message transmissions during the whole synchronization interval, and it dynamically adjusts minimum contention window size for different non-safety services according to the traffic conditions. Theoretical model analysis and extensive simulation results show that the EQM-MAC protocol can support QoS services, while ensuring the high saturation throughput and low transmission delay for non-safety applications.

Interference-aware power control for multi-radio multi-channel wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-09-01

Full Text Available are well known in [9], [6]. The operation of multi-radio multi-channel (MRMC) WMNs generally requires sustainable energy supply. Substantial deployments of WMNs have recently been witnessed in rural and remote communities [4]. In such applications...]. Power resources are dynamically adjusted by each NIC using intra and inter-subsystem (channel) states. Due to the decentralized nature, each MP assumes imperfect knowledge about the global network. Further we assume that there exists...

Ultrasonic attenuation in the superconducting and intermediate states of pure and doped type I superconductors

International Nuclear Information System (INIS)

Chaudhuri, K.D.; Singh, R.

1982-01-01

The attenuation of longitudinal ultrasonic waves has been measured in single crystals of indium (99.999%), indium doped with 0.003 at % of tin, and indium doped with 0.002 at % of bismuth in the intermediate and superconducting states over the frequency range 10--30 MHz. For the bismuth-doped indium specimen, measurements were taken for three different physical states, i.e., for three different dislocation densities, and for the indium and the tin-doped indium specimens, measurements were for one-physical state. For a particular measurement, the same physical state was maintained both in the intermediate and superconducting states. A temperature-dependent oscillatory behavior of the ultrasonic attenuation was observed in the intermediate state in all the three specimens, but in the superconducting state the oscillatory behavior was observed only in the bismuth-doped specimen. Two phases have been identified in the superconducting layers of the intermediate state and there is only one phase in the superconducting state of the bismuth-doped sample. The origin of the two phases in the intermediate state and that of the single phase in the superconducting state of the bismuth-doped sample are discussed. A qualitative explanation is presented for the occurrence of oscillatory attenuation in the intermediate state irrespective of the nature of the dopant and the selective occurrence of oscillatory attenuation in the superconducting state due to the nature of the dopant

Time-varying bispectral analysis of visually evoked multi-channel EEG

Science.gov (United States)

Chandran, Vinod

2012-12-01

Theoretical foundations of higher order spectral analysis are revisited to examine the use of time-varying bicoherence on non-stationary signals using a classical short-time Fourier approach. A methodology is developed to apply this to evoked EEG responses where a stimulus-locked time reference is available. Short-time windowed ensembles of the response at the same offset from the reference are considered as ergodic cyclostationary processes within a non-stationary random process. Bicoherence can be estimated reliably with known levels at which it is significantly different from zero and can be tracked as a function of offset from the stimulus. When this methodology is applied to multi-channel EEG, it is possible to obtain information about phase synchronization at different regions of the brain as the neural response develops. The methodology is applied to analyze evoked EEG response to flash visual stimulii to the left and right eye separately. The EEG electrode array is segmented based on bicoherence evolution with time using the mean absolute difference as a measure of dissimilarity. Segment maps confirm the importance of the occipital region in visual processing and demonstrate a link between the frontal and occipital regions during the response. Maps are constructed using bicoherence at bifrequencies that include the alpha band frequency of 8Hz as well as 4 and 20Hz. Differences are observed between responses from the left eye and the right eye, and also between subjects. The methodology shows potential as a neurological functional imaging technique that can be further developed for diagnosis and monitoring using scalp EEG which is less invasive and less expensive than magnetic resonance imaging.

Increase in information by improvement of measuring method in a multichannel taste sensor; Multichannel aji sensor no sokutei hoho no kairyo ni yoru johoryo no zoka

Energy Technology Data Exchange (ETDEWEB)

Ikezaki, H.; Taniguchi, A. [Anritsu Corp., Tokyo (Japan)

1998-11-01

We have developed a multichannel taste sensor with lipid membranes which can detect and quantify the basic taste substances in aqueous solution. The aim of the present study is to increase selectivity to adsorptive taste substances (bitter, umami and astringent taste substances) for quantification of taste by improving measuring methods. High selectivity to adsorptive taste substances is obtained by CPA measurement algorithm (CPA: Change of membrane Potential caused by Adsorption). High repeatability is also obtained by developing a cleaning technique of taste sensor. 18 refs., 8 figs., 5 tabs.

Multichannel infinite clipping as a form of sampling of speech signals

International Nuclear Information System (INIS)

Guidarelli, G.

1985-01-01

A remarkable improvement of both intelligibility and naturalness of infinitely clipped speech can be achieved by means of a multichannel system in which the speech signal is splitted into several band-pass channels before the clipping and successively reconstructed by summing up the clipped outputs of each channel. A possible explanation of such an improvement is given, founded on the so-called zero-based representation of band limited signals where the zero-crossings sequence is considered as a set of samples of the signal

Network based multi-channel digital flash X-ray imaging system

International Nuclear Information System (INIS)

Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin; Zhang Qi; Zheng Futang

2000-01-01

A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images are presented. The software for object separating, mass calculating, 3D positioning, speed determining and cavity reconstruction are described

Network based multi-channel digital flash X-ray imaging system

International Nuclear Information System (INIS)

Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin

2003-01-01

A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images of terminal ballistics are presented. The software for object separating, profile calculating and 3D cavity reconstruction are described

Merkuriev Cut-off in e+ − H Multichannel Scattering Calculations

Directory of Open Access Journals (Sweden)

Vitaly A. Gradusov

2016-03-01

Full Text Available We present the results of positron-Hydrogen multichannel scattering calculations performed on the base of Faddeev-Merkuriev equations. We discuss an optimal choice of the Merkuriev’s Coulomb splitting parameters. Splitting the Coulomb potential in two-body configuration space is applicable for a limited energy range. Splitting the potential in three-body configuration space makes it possible to perform calculations in a broader range of energies and to optimize the numerical convergence. Scattering cross sections for zero total angular momentum for all processes between the positronium formation threshold and the third excitation threshold of the Hydrogen atom are reported.

Multi-channel counter-current chromatography for high-throughput fractionation of natural products for drug discovery.

Science.gov (United States)

Wu, Shihua; Yang, Lu; Gao, Yuan; Liu, Xiaoyue; Liu, Feiyan

2008-02-08

A multi-channel counter-current chromatography (CCC) method has been designed and fabricated for the high-throughput fractionation of natural products without complications sometimes encountered with other conventional chromatographic systems, such as irreversible adsorptive constituent losses and deactivation, tailing of solute peaks and contamination. It has multiple independent CCC channels and each channel connects independent separation column(s) by parallel flow tubes, and thus the multi-channel CCC apparatus can achieve simultaneously two or more independent chromatographic processes. Furthermore, a high-throughput CCC fractionation method for natural products has been developed by a combination of a new three-channel CCC apparatus and conventional parallel chromatographic devices including pumps, sample injectors, effluent detectors and collectors, and its performance has been displayed on the fractionation of ethyl acetate extracts of three natural materials Solidago canadensis, Suillus placidus, and Trichosanthes kirilowii, which are found to be potent cytotoxic to tumor cell lines in the course of screening the antitumor candidates. By combination of biological screening programs and preparative high-performance liquid chromatography (HPLC) purification, 22.8 mg 6 beta-angeloyloxykolavenic acid and 29.4 mg 6 beta-tigloyloxykolavenic acid for S. canadensis, 25.3mg suillin for S. placidus, and 6.8 mg 23,24-dihydrocucurbitacin B for T. Kirilowii as their major cytotoxic principles were isolated from each 1000 mg crude ethyl acetate extract. Their chemical structures were characterized by electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance. The overall results indicate the multi-channel CCC is very useful for high-throughput fractionation of natural products for drug discovery in spite of the solvent balancing requirement and the lower resolution of the shorter CCC columns.

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.

Multichannel spin polarimeter for energy- and angle-dispersive photoemission measurements

International Nuclear Information System (INIS)

Kolbe, Michaela

2011-01-01

Spin polarization measurements of free electrons remain challenging since their first realization by Mott. The relevant quantity of a spin polarimeter is its figure of merit, FoM=S 2 I/I 0 , with the asymmetry function S and the ratio between scattered and primary intensity I/I 0 . State-of-the-art devices are based on single-channel scattering (spin-orbit or exchange interaction) which is characterized by FoM ≅10 -4 . On the other hand, modern hemispherical analyzers feature an efficient multichannel detection of spin-integral intensity with more than 10 4 data points simultaneously. In comparison between spin-resolved and spin-integral electron spectroscopy we are thus faced with a difference in counting efficiency by 8 orders of magnitude. The present work concentrates on the development and investigation of a novel technique for increasing the efficiency in spin-resolved electron spectroscopy by multichannel detection. The spin detector was integrated in a μ-metal shielded UHV-chamber and mounted behind a conventional hemispherical analyzer. The electrostatic lens system's geometry was determined by electron-optical simulations. The basic concept is the k parallel -conserving elastic scattering of the (0,0)-beam on a W(100) scattering crystal under 45 impact angle. It could be demonstrated that app. 960 data points (15 energy and 64 angular points) could be displayed simultaneously on a delayline detector in an energy interval of ≅3 eV. This leads to a two-dimensional figure of merit of FoM 2D =1.7. Compared to conventional spin detectors, the new type is thus characterized by a gain in efficiency of 4 orders of magnitude. The operational reliability of the new spin polarimeter could be proven by measurements with a Fe/MgO(100) and O p(1 x 1)/Fe(100)-sample, where results from the literature were reproduced with strongly decreased measuring time. Due to the high intensity it becomes possible, to investigate strongly reactive samples in a short time. This

Multichannel analyzer for nuclear spectrometry with FPGA using Vivado

International Nuclear Information System (INIS)

Garcia D, A.; Hernandez D, V. M.; Vega C, H. R.; Ordaz G, O. O.; Ibarra D, S.; Bravo M, I.

2017-09-01

The different applications of ionizing radiation have made this a very significant and useful tool, in turn can be dangerous for living beings if they are exposed to uncontrolled doses. However, due to its characteristics, cannot be perceived by the five senses, in such a way that in order to know the presence of it, radiation detectors and additional devices are required that allow to quantify and classify it. This is the case of the multichannel analyzer that is responsible for separating the different pulse heights that are generated in the detectors, in a certain number of channels; according to the number of bits of the analog to digital converter. The development or conditioning of nuclear technology has increased considerably due to the demand of the applications; therefore this allows developing systems that cover some commercial requirements, cost and volume in relation to the user needs. The objective of the work was to design and implement an intellectual property core (IP Core) which functions as a multichannel analyzer for nuclear spectrometry. For the IP Core design methodology, its components were created in VHDL hardware description language and packaged in the Vivado design suite, making use of resources such as the ARM processor cores that the Zynq chip contains. Likewise, for the first phase of the implementation, the hardware architecture was embedded in the FPGA and the application for the ARM processor was programmed in C language. For the second phase, the management, control and visualization of the results, a virtual instrument was developed in the LabView programming platform. The data obtained as a result of the development and implementation of the IP Core was observed graphically in a histogram that is part of the aforementioned virtual instrument. (Author)

Tidal disruption of white dwarfs by intermediate mass black holes

Directory of Open Access Journals (Sweden)

Bode T.

2012-12-01

Full Text Available Modeling ultra-close encounters between a white dwarf and a spinning, intermediate mass black hole requires a full general relativistic treatment of gravity. This paper summarizes results from such a study. Our results show that the disruption process and prompt accretion of the debris strongly depend on the magnitude and orientation of the black hole spin. On the other hand, the late-time accretion onto the black hole follows the same decay, Ṁ ∝  t−5/3, estimated from Newtonian gravity disruption studies. The spectrum of the fallback material peaks in the soft X-rays and sustains Eddington luminosity for 1–3 yrs after the disruption. The orientation of the black hole spin has also a profound effect on how the outflowing debris obscures the central region. The disruption produces a burst of gravitational radiation with characteristic frequencies of ∼3.2 Hz and strain amplitudes of ∼10−18 for galactic intermediate mass black holes.

Effects of intermediate load on performance limitations in excitation control

Directory of Open Access Journals (Sweden)

Pichai Aree

2008-05-01

Full Text Available The stability of excitation control systems is of great concern in power system operations. In this paper, the effects of intermediate load on performance limitation in excitation control are studied. The results reveal that the open-loop characteristic of synchronous machine’s flux linkage can be changed from minimum to non-minimum phase at a high level of intermediate load. This change leads to instability of synchronous machines under manual excitation control. A particular emphasis is also given to investigate the fundamental limitations in excitation control, imposed by non-minimum phases with regard to the open-loop right-half-plane (ORHP pole. The study demonstrates the difficulties of excitation control tuning to achieve the desired performance and robustness under the ORHP pole occurrence. Moreover, this paper shows the conditional stability in excitation control loop, where either an increase or decrease of the exciter gain causes a destabilization of the system’s stability. Frequency response techniques are used for these investigations.

Selective visual scaling of time-scale processes facilitates broadband learning of isometric force frequency tracking.

Science.gov (United States)

King, Adam C; Newell, Karl M

2015-10-01

The experiment investigated the effect of selectively augmenting faster time scales of visual feedback information on the learning and transfer of continuous isometric force tracking tasks to test the generality of the self-organization of 1/f properties of force output. Three experimental groups tracked an irregular target pattern either under a standard fixed gain condition or with selectively enhancement in the visual feedback display of intermediate (4-8 Hz) or high (8-12 Hz) frequency components of the force output. All groups reduced tracking error over practice, with the error lowest in the intermediate scaling condition followed by the high scaling and fixed gain conditions, respectively. Selective visual scaling induced persistent changes across the frequency spectrum, with the strongest effect in the intermediate scaling condition and positive transfer to novel feedback displays. The findings reveal an interdependence of the timescales in the learning and transfer of isometric force output frequency structures consistent with 1/f process models of the time scales of motor output variability.

Multichannel amplitude analyser for nuclear spectrometry

International Nuclear Information System (INIS)

Jankovic, S.; Milovanovic, B.

2003-01-01

A multichannel amplitude analyser with 4096 channels was designed. It is based on a fast 12-bit analog-to-digital converter. The intended purpose of the instrument is recording nuclear spectra by means of scintillation detectors. The computer link is established through an opto-isolated serial connection cable, thus reducing instrument sensitivity to disturbances originating from digital circuitry. Refreshing of the data displayed on the screen occurs on every 2.5 seconds. The impulse peak detection is implemented through the differentiation of the amplified input signal, while the synchronization with the data coming from the converter output is established by taking advantage of the internal 'pipeline' structure of the converter itself. The mode of operation of the built-in microcontroller provides that there are no missed impulses, and the simple logic network prevents the initiation of the amplitude reading sequence for the next impulse in case it appears shortly after its precedent. The solution proposed here demonstrated a good performance at a comparatively low manufacturing cost, and is thus suitable for educational purposes (author)

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.

Components of cross-frequency modulation in health and disease

Directory of Open Access Journals (Sweden)

Elena A Allen

2011-07-01

Full Text Available The cognitive deficits associated with schizophrenia are commonly believed to arise from the abnormal temporal integration of information, however a quantitative approach to assess network coordination is lacking. Here, we propose to use cross-frequency modulation, the dependence of local high-frequency activity on the phase of widespread low-frequency oscillations, as an indicator of network coordination and functional integration. In an exploratory analysis based on pre-existing data, we measured cross-frequency modulation from multi-channel EEG recordings acquired while schizophrenia patients (n = 47 and healthy controls (n = 130 performed an auditory oddball task. Novel application of independent component analysis (ICA to modulation data delineated components with specific spatial and spectral profiles, the weights of which showed co-variation with diagnosis. Global cross-frequency modulation was significantly greater in healthy controls (F1,175=9.25, P<0.005, while modulation at fronto-temporal electrodes was greater in patients (F1,175 =17.5, P<0.0001. We further found that the weights of schizophrenia-relevant components were associated with genetic polymorphisms at previously identified risk loci. Global cross-frequency modulation decreased with copies of 957C allele in the gene for the dopamine D2 receptor (r = −0.20, P < 0.01 across all subjects. Additionally, greater ‘aberrant’ fronto-temporal modulation in schizophrenia patients was correlated with several polymorphisms in the gene for the α2-subunit of the GABAA receptor (GABRA2 as well as the total number of risk alleles in GABRA2 (r = 0.45, P < 0.01. Overall, our results indicate great promise for this approach in establishing patterns of cross-frequency modulation in health and disease and elucidating the roles of oscillatory interactions in functional connectivity.

Large capacity, high-speed multiparameter multichannel analysis system

International Nuclear Information System (INIS)

Hendricks, R.W.; Seeger, P.A.; Scheer, J.W.; Suehiro, S.

1980-01-01

A data acquisition system for recording multiparameter digital data into a large memory array at over 2.5 MHz is described. The system consists of a MOSTEK MK8600 2048K x 24-bit memory system, I/O ports to various external devices including the CAMAC dataway, a memory incrementer/adder and a daisy-chain of experiment-specific modules which calculate the memory address which is to be incremented. The design of the daisy-chain permits multiple modules and provides for easy modification as experimental needs change. The system has been designed for use in multiparameter, multichannel analysis of high-speed data gathered by position-sensitive detectors at conventional and synchrotron x-ray sources as well as for fixed energy and time-of-flight diffraction at continuous and pulsed neutron sources

Connection of automatic integral multichannel monitor of aerosol concentration

International Nuclear Information System (INIS)

Krejci, M.; Stulik, P.

1985-01-01

The instrument consists of the actual aerosol concentration monitor with two equivalent inputs, of an electropneumatic sampling selector, an aerosol pump, an electropneumatic valve, and of an exhaust device. For integral operating mode the instrument allows rapid checking and indication of exceedance of the permissible aerosol concentration limit at any sampling point. Upon exceedance of the permissible concentration limit, the device automatically switches into the multichannel cyclic measurement mode while the sampling point is identified where the aerosol concentration was increased. An emergency is displayed if the permissible limit has been exceeded. Following removal of the source of dangerous aerosol concentration, the control unit automatically switches the device into the integral measurement mode. (J.B.)

Multichannel model of magneto tunneling in disordered electron nanodevices

International Nuclear Information System (INIS)

Amado, M.; Dominguez-Adame, F.; Diez, E.

2005-01-01

We present a multichannel model of magnetotunneling transport in unintentionally disordered double-barrier GaAs-Al x Ga 1-x As heterostructures. The source of disorder comes from interface roughness at the heterojunctions. Disorder break translational symmetry along the lateral direction and therefore electrons can be scattered off the growth direction. The model correctly describes channel mixing due to these elastic scattering events. The magnetic field applied to the double-barrier heterostructure splits the resonant level into a set of equally-spaced resonances, the level spacing increasing with the magnetic field. We discuss the influence of the various parameters (epilayer widths and magnitude or disorder) on the lineshape of the resonant levels

MHD intermediate shock discontinuities: Pt. 1

International Nuclear Information System (INIS)

Kennel, C.F.; Blandford, R.D.; Coppi, P.

1989-01-01

Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic. (author)

Annihilation probability density and other applications of the Schwinger multichannel method to the positron and electron scattering

International Nuclear Information System (INIS)

Varella, Marcio Teixeira do Nascimento

2001-12-01

We have calculated annihilation probability densities (APD) for positron collisions against He atom and H 2 molecule. It was found that direct annihilation prevails at low energies, while annihilation following virtual positronium (Ps) formation is the dominant mechanism at higher energies. In room-temperature collisions (10 -2 eV) the APD spread over a considerable extension, being quite similar to the electronic densities of the targets. The capture of the positron in an electronic Feshbach resonance strongly enhanced the annihilation rate in e + -H 2 collisions. We also discuss strategies to improve the calculation of the annihilation parameter (Z eff ), after debugging the computational codes of the Schwinger Multichannel Method (SMC). Finally, we consider the inclusion of the Ps formation channel in the SMC and show that effective configurations (pseudo eigenstates of the Hamiltonian of the collision ) are able to significantly reduce the computational effort in positron scattering calculations. Cross sections for electron scattering by polyatomic molecules were obtained in three different approximations: static-exchange (SE); tatic-exchange-plus-polarization (SEP); and multichannel coupling. The calculations for polar targets were improved through the rotational resolution of scattering amplitudes in which the SMC was combined with the first Born approximation (FBA). In general, elastic cross sections (SE and SEP approximations) showed good agreement with available experimental data for several targets. Multichannel calculations for e - -H 2 O scattering, on the other hand, presented spurious structures at the electronic excitation thresholds (author)

Radio Frequency Fragment Separator at NSCL

International Nuclear Information System (INIS)

Bazin, D.; Andreev, V.; Becerril, A.; Doleans, M.; Mantica, P.F.; Ottarson, J.; Schatz, H.; Stoker, J.B.; Vincent, J.

2009-01-01

A new device has been designed and built at NSCL which provides additional filtering of radioactive beams produced via projectile fragmentation. The Radio Frequency Fragment Separator (RFFS) uses the time micro structure of the beams accelerated by the cyclotrons to deflect particles according to their time-of-flight, in effect producing a phase filtering. The transverse RF (Radio Frequency) electric field of the RFFS has superior filtering performance compared to other electrostatic devices, such as Wien filters. Such filtering is critical for radioactive beams produced on the neutron-deficient side of the valley of stability, where strong contamination occurs at intermediate energies from 50 to 200 MeV/u.

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.

Design of multi-channel analyzer's monitoring system based on embedded system

International Nuclear Information System (INIS)

Yang Tao; Wei Yixiang

2007-01-01

A new Multi-Channel Analyzer's Monitoring system based on ARM9 Embedded system is introduced in this paper. Some solutions to problem are also discussed during the procedure of design, installation and debugging on Linux system. The Monitoring system is developed by using MiniGUI and Linux software system API, with the functions of collecting, displaying and I/O data controlling 1024 channels datum. They are all realized in real time, with the merits of low cost, small size and portability. All these lay the foundation of developing homemade Digital and Portable nuclear spectrometers. (authors)

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 are init...... 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...

Multiple-animal MR imaging using a 3T clinical scanner and multi-channel coil for volumetric analysis in a mouse tumor model

International Nuclear Information System (INIS)

Mitsuda, Minoru; Yamaguchi, Masayuki; Furuta, Toshihiro; Fujii, Hirofumi; Nabetani, Akira; Hirayama, Akira; Nozaki, Atsushi; Niitsu, Mamoru

2011-01-01

Multiple small-animal magnetic resonance (MR) imaging to measure tumor volume may increase the throughput of preclinical cancer research assessing tumor response to novel therapies. We used a clinical scanner and multi-channel coil to evaluate the usefulness of this imaging to assess experimental tumor volume in mice. We performed a phantom study to assess 2-dimensional (2D) geometric distortion using 9-cm spherical and 32-cell (8 x 4 one-cm 2 grids) phantoms using a 3-tesla clinical MR scanner and dedicated multi-channel coil composed of 16 5-cm circular coils. Employing the multi-channel coil, we simultaneously scanned 6 or 8 mice bearing sarcoma 180 tumors. We estimated tumor volume from the sum of the product of tumor area and slice thickness on 2D spin-echo images (repetition time/echo time, 3500/16 ms; in-plane resolution, 0.195 x 0.195 x 1 mm 3 ). After MR acquisition, we excised and weighed tumors, calculated reference tumor volumes from actual tumor weight assuming a density of 1.05 g/cm 3 , and assessed the correlation between the estimated and reference volumes using Pearson's test. Two-dimensional geometric distortion was acceptable below 5% in the 9-cm spherical phantom and in every cell in the 32-cell phantom. We scanned up to 8 mice simultaneously using the multi-channel coil and found 11 tumors larger than 0.1 g in 12 mice. Tumor volumes were 1.04±0.73 estimated by MR imaging and 1.04±0.80 cm 3 by reference volume (average±standard deviation) and highly correlated (correlation coefficient, 0.995; P<0.01, Pearson's test). Use of multiple small-animal MR imaging employing a clinical scanner and multi-channel coil enabled accurate assessment of experimental tumor volume in a large number of mice and may facilitate high throughput monitoring of tumor response to therapy in preclinical research. (author)