scholarly journals Generalization of the model-independent Laurent–Pietarinen single-channel pole-extraction formalism to multiple channels

2016 ◽  
Vol 755 ◽  
pp. 452-455 ◽  
Author(s):  
Alfred Švarc ◽  
Mirza Hadžimehmedović ◽  
Hedim Osmanović ◽  
Jugoslav Stahov ◽  
Lothar Tiator ◽  
...  
Keyword(s):  
Single Channel ◽  
Multiple Channels ◽  
Model Independent

Asymptotic distributions of apparent open times and shut times in a single channel record allowing for the omission of brief events

1992 ◽  
Vol 337 (1282) ◽  
pp. 383-404 ◽  
Keyword(s):  
Continuous Time ◽  
Dead Time ◽  
Single Channel ◽  
Asymptotic Distributions ◽  
Accurate Approximation ◽  
Alternative Representation ◽  
Discrete States ◽  
Probability Densities ◽  
Model Independent ◽  
Two State Model

The openings and shuttings of individual ion channel molecules can be described by a Markov process with discrete states in continuous time. The predicted distributions of the durations of open times, shut times, bursts of openings, etc. are all described, in principle, by mixtures of exponential densities. In practice it is usually found that some of the open times, and the shut times, are too short to be detected reliably. If a fixed dead-time τ is assumed then it is possible to define, as an approximation to what is actually observed, an ‘extended opening’ or e-opening which starts with an opening of duration at least τ followed by any number of openings and shuttings, all the shut times being shorter than τ ; the e-opening ends when a shut time longer than τ occurs. A similar definition is used for e-shut times. The probability densities, f(t) , of these extended times have previously been obtained as expressions which become progressively more complicated, and numerically unstable to compute, as t→∞. In this paper we present, for the two-state model, an alternative representation as an infinite series of which a small number of terms gives a very accurate approximation of f(t) for large t . For the general model we present an asymptotic representation as a mixture of exponentials which is accurate for all except quite small values of t . Some simple model-independent corrections for missed events are discussed in relationship to the exact solutions.

Superposition properties of independent ion channels

1989 ◽  
Vol 238 (1291) ◽  
pp. 155-170 ◽  
Keyword(s):  
Ion Channels ◽  
Sojourn Time ◽  
Single Channel ◽  
Stochastic Modelling ◽  
Multiple Channels ◽  
Channel Activity ◽  
Channel System ◽  
Distributional Properties ◽  
Multichannel Systems ◽  
Selection Of

Membrane patches usually contain several ion channels of a given type. However, most of the stochastic modelling on which data analysis (in particular, estimation of kinetic constants) is currently based, relates to a single channel rather than to multiple channels. Attempts to circumvent this problem experimentally by recording under conditions where channel activity is low are restrictive and can introduce bias; moreover, possibly important information on how multichannel systems behave will be missed. We have extended existing theory to multichannel systems by applying results from point process theory to derive some distributional properties of the various types of sojourn time that occur when a given number of channels are open in a system containing a specified number of independent channels in equilibrium. Separate development of properties of a single channel and the superposition of several such independent channels simplifies the presentation of known results and extensions. To illustrate the general theory, particular attention is given to the types of sojourn time that occur in a two channel system; detailed expressions are presented for a selection of models, both Markov and non-Markov.

A Microfluidic Based High Throughput Resistive Pulse Sensor

2006 ◽  
Author(s):  
Jiang Zhe ◽  
Ashish Jagtiani ◽  
Nazmul Mamun ◽  
Prashanta Dutta ◽  
Jun Hu ◽  
...  
Keyword(s):  
Single Channel ◽  
Electrolyte Solutions ◽  
Power Source ◽  
Deionized Water ◽  
Multiple Channels ◽  
Single Chip ◽  
Nanoscale Particles ◽  
Resistive Pulse ◽  
Pulse Sensor ◽  
Multiple Sensing

We describe a micromachined. resistive pulse sensor with multiple sensing microchannels. A unique design placing measurement microelectrodes in the center of the microchannels is demonstrated. This design creates isolation resistances among channels and thus circumvents the crosstalk caused by automatic electrical connection among microchannels. When implemented using microscale channels, the design is appropriate for the sensing of microscale particles in deionized water or in very dilute electrolyte solution; using nanoscale channels, the design is appropriate for the sensing of nanoscale particles in electrolyte solutions of any concentration. The design has multiple channels operating in parallel, but integrated with just one sample reservoir and one power source. The results with a four-channel device show that this device is capable of differentiating and counting micro polymethacrylate particles and Juniper pollens rapidly. The throughput is improved significantly in comparison to a single channel device. The concept can be extended to a large number of sensing channels in a single chip for significant improvement in throughput.

scholarly journals Naming in Multichannel with Beeps in the Strong Model

2020 ◽  
Vol 10 (20) ◽  
pp. 7164
Author(s):  
Layla S. Aldawsari ◽  
Tom Altman
Keyword(s):  
Collision Detection ◽  
Single Channel ◽  
Synchronous Communication ◽  
Monte Carlo Algorithm ◽  
Optimal Time ◽  
Communication Model ◽  
Multiple Channels ◽  
Probability Of Success ◽  
Las Vegas Algorithm ◽  
Anonymous Processes

In this paper, a system of anonymous processes is considered that communicates with beeps through multiple channels in a synchronous communication model. In beeping channels, processes are limited to hearing either a beep or a silence from the channel with no collision detection. A strong model is assumed in which a process can beep on any single channel and listen on any specific channel during a single round. The goal is to develop distributed naming algorithms for two models where the number of processes is either known or unknown. A Las Vegas algorithm was developed for naming anonymous processes when the number of processes is known. This algorithm has an optimal time complexity of O(nlogn) rounds and uses O(nlogn) random bits, where n is the number of processes for the largest group. For the model with an unknown number of processes, a Monte Carlo algorithm was developed, which has an optimal running time of O(nlogn) rounds and a probability of success that is at least 1−12Ω(logn). The algorithms solve the naming problem in new models where processes communicate through multiple channels.

scholarly journals A Simple and Practical Scheme Using Multiple Channels for Improving System Spectral Efficiency of Highly Dense Wireless LANs

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Jungmin So ◽  
Joosang Lee
Keyword(s):  
Single Channel ◽  
Wireless Lans ◽  
Multiple Channels ◽  
Medium Access ◽  
Simple Scheme ◽  
Carrier Sense ◽  
Hidden Terminals ◽  
Carrier Sensing ◽  
Simulation Results ◽  
Practical Scheme

As the density of wireless LANs increases, performance degradation caused by hidden terminals and exposed terminals becomes significant. These problems come from carrier sensing based medium access control used in current wireless LANs. Hidden terminals are created if carrier sense threshold is too high, whereas exposed terminals are created if carrier sense threshold is too low. A good threshold depends on how far nodes are placed from their destinations, but that cannot be controlled by the system. In this paper, we propose a simple scheme that makes use of multiple channels. Multiple channels could be utilized by equipping multiple radios or using advanced hardware such as SDR to divide a single channel into multiple channels. Nodes are assigned channels based on their estimated distance from the AP. Once the assignment is done, carrier sense threshold for the channel is selected so that as many concurrent transmissions take place as possible, while preventing hidden terminals. Simulation results show that the proposed mechanism achieves significantly higher throughput without causing starvation at the edge nodes.

scholarly journals Development of Single-Channel Hybrid BCI System Using Motor Imagery and SSVEP

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Li-Wei Ko ◽  
S. S. K. Ranga ◽  
Oleksii Komarov ◽  
Chung-Chiang Chen
Keyword(s):  
Motor Imagery ◽  
High Performance ◽  
Evoked Potential ◽  
Single Channel ◽  
Computer Interface ◽  
Multiple Channels ◽  
Eeg Signal ◽  
Feature Information ◽  
Improved Accuracy ◽  
Bci System

Numerous EEG-based brain-computer interface (BCI) systems that are being developed focus on novel feature extraction algorithms, classification methods and combining existing approaches to create hybrid BCIs. Several recent studies demonstrated various advantages of hybrid BCI systems in terms of an improved accuracy or number of commands available for the user. But still, BCI systems are far from realization for daily use. Having high performance with less number of channels is one of the challenging issues that persists, especially with hybrid BCI systems, where multiple channels are necessary to record information from two or more EEG signal components. Therefore, this work proposes a single-channel (C3 or C4) hybrid BCI system that combines motor imagery (MI) and steady-state visually evoked potential (SSVEP) approaches. This study demonstrates that besides MI features, SSVEP features can also be captured from C3 or C4 channel. The results show that due to rich feature information (MI and SSVEP) at these channels, the proposed hybrid BCI system outperforms both MI- and SSVEP-based systems having an average classification accuracy of 85.6 ± 7.7% in a two-class task.

Early Prediction of Non-response to Anti-depressive Treatment with an Easy-to-use Electrophysiological Index Dynamics

2017 ◽  
Vol 41 (S1) ◽  
pp. S145-S145
Author(s):  
S. Yariv ◽  
G. Shahaf ◽  
B. Bloch ◽  
A. Reshef ◽  
Y. Bloch
Keyword(s):  
Single Channel ◽  
Severe Depression ◽  
Response To Treatment ◽  
Healthy Controls ◽  
Multiple Channels ◽  
Proof Of Concept ◽  
Treatment Interventions ◽  
Major Significance ◽  
Treatment Onset ◽  
Frequent Sampling

IntroductionThe evaluation of response to pharmacological treatment in MDD requires 6–8 weeks. Therefore, the ability to predict response, and especially lack of response to treatment, as early as possible after treatment onset or change, is of major significance. Many studies demonstrated significant results regarding the ability to use EEG and ERP markers. However, these markers are derived from long EEG/ERP samples, often from multiple channels, which render them impractical for frequent sampling.MethodsWe developed a new electrophysiological attention-related marker from a single channel (2 electrodes) and 1 minute samples. This work presents an initial evaluation of the ability to harness this marker, for early differentiation between responders and non-responders to anti-depressive treatment, in 26 patients with various levels of depression and heterogeneous treatment interventions and 10 healthy controls. Subjects who initiated treatment for depression were followed clinically through their Hamilton depression scores as well as their EEG activity twice a week for a period of 8 weeks. Any acceptable anti-depressive treatment been included. The improvement in Hamilton scores at the end of 8 weeks used to discriminate responders and non-responders.ResultsWithin two weeks, we could differentiate between non-responders and responders to anti-depressive treatment, with absolute discrimination between subjects with moderate to severe depression, and with 0.71 sensitivity and 0.96 specificity within the whole depressed subjects.ConclusionsThis is a proof of concept for an easy to use, cheap and quick marker for the lack of respond to anti-depressive treatment within two weeks of anti-depressive treatment.

scholarly journals Experimental study of multiple-channel automotive underbody diffusers

2010 ◽  
Vol 224 (7) ◽  
pp. 865-879 ◽  
Author(s):  
L Jowsey ◽  
M Passmore
Keyword(s):  
Bluff Body ◽  
Single Channel ◽  
Multiple Channels ◽  
Road Vehicles ◽  
Multiple Channel ◽  
Race Car ◽  
Body Model ◽  
Reduce Emissions ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Underbody diffusers are used widely in race car applications because they can significantly improve the cornering capacity of the vehicle through the generation of a downforce. They are also likely to have a wider role in reducing the drag in road vehicles as it becomes increasingly important to reduce emissions of carbon dioxide. This paper reports on a wind tunnel investigation, using a simplified bluff body model, into the effect of splitting a simple plane diffuser into multiple channels. Tests are reported for a range of diffuser geometries suitable for road and race car applications. The results for the lift, the drag, and the incremental changes to the lift-to-drag ratio are reported and discussed in terms of the underbody pressures. While broadly similar trends to the single-channel plane diffuser are seen in the multiple-channel diffuser configurations, it was found that the effect of increasing the number of channels depended on the flow regimes present in the plane diffuser. At angles just above the plane diffuser optimum, where the flow is partially separated, the multiple-channel configurations give large improvements in the downforce with minimal increase in the drag, significantly extending the performance envelope. The pressure maps indicate that the gains occur through improved diffuser pumping and pressure recovery in both the inner and the outer channels.

scholarly journals Single-Channel Data Broadcasting under Small Waiting Latency

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hsiang-Fu Yu
Keyword(s):  
Single Channel ◽  
Video On Demand ◽  
Video Data ◽  
Multiple Channels ◽  
Digital Video Broadcasting ◽  
Multiple Channel ◽  
Video Broadcasting ◽  
Comparison Results ◽  
Periodic Broadcasting ◽  
Efficient Video

Due to the advancement of network technology, video-on-demand (VoD) services are growing in popularity. However, individual stream allocation for client requests easily causes a VoD system overload; when its network and disk bandwidth cannot match client growth. This study thus presents a fundamentally different approach by focusing solely on a class of applications identified as latency tolerant applications. Because video broadcasting does not provide interactive (i.e., VCR) functions, a client is able to tolerate playback latency from a video server. One efficient broadcasting method is periodic broadcasting, which divides a video into smaller segments and broadcasts these segments periodically on multiple channels. However, numerous practical systems, such as digital video broadcasting-handheld (DVB-H), do not allow clients to download video data from multiple channels because clients usually only have one tuner. To resolve this problem in multiple-channel broadcasting, this study proposes a novel single-channel broadcasting scheme, which leverages segment-broadcasting capability further for more efficient video delivery. The comparison results show that, with the same settings of broadcasting bandwidth, the proposed scheme outperforms the alternative broadcasting scheme, the hopping insertion scheme, SingBroad, PAS, and the reverse-order scheduling scheme for the maximal waiting time.

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