Articles de revues : « Back Channel »

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Choi, Charles Q. « Back-Channel Chatter ». Scientific American 293, n^o 3 (septembre 2005) : 34. http://dx.doi.org/10.1038/scientificamerican0905-34c.

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Jones, Peter. « Ethical Dilemmas of Back-Channel Diplomacy : Necessary Secrecy or a Secret Foreign Policy ? » Hague Journal of Diplomacy 13, n^o 4 (12 novembre 2018) : 483–501. http://dx.doi.org/10.1163/1871191x-12341374.

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Summary Back-channel diplomacy allows participants to hold dialogues with actors with whom they are not prepared to talk openly. The secrecy of back channels can, however, permit a small elite to escape oversight and scrutiny to achieve unaccountable aims. This article examines the ethical dilemmas raised by the secrecy of back channels. It seeks to develop some practical ‘tests’ that can be used to ask whether a back channel is straying, or has strayed, into dangerous ethical territory. The article advances three such tests for further development, but also concludes that they cannot be ‘absolute’; the context in which a back channel operates is the key variable.

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Yazdfazeli, Maliheh, Khalil Motallebzadeh et Mohammad Ali Fatemi. « EXPLICIT BACK-CHANNEL STRATEGY TRAINING AND IMPROVEMENT OF SPEAKING SKILL : CASE OF IRANIAN EFL LEARNERS ». Indonesian EFL Journal 1, n^o 1 (12 septembre 2017) : 17. http://dx.doi.org/10.25134/ieflj.v1i1.609.

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This study explores the effect of explicit back-channel strategy training on Iranian EFL language learners� success in speaking skill. Back-channels are turn taking responses uttered by the listeners. Forty homogenous learners (20 male, 20 female) were randomly assigned to four groups (2 experimental, 2 control). They were at intermediate level in terms of general English proficiency based on the results of Oxford Placement Test (OPT) and pre-test oral Proficiency Interview. After 18 sessions of treatment of back-channels for experimental groups, that were based on the methodological theory of English language teaching suggested by Doff (1990) and Harmer (1991), post- test oral proficiency test was administered for experimental and control groups. The findings of pretest and posttest oral exams revealed that EFL language learners� oral performance (speaking) in experimental groups improved. The result revealed that females employed back-channels more often than males when they were participating in a conversation. The type of back-channel both genders employed the most was short utterances, such as �yes�, and the most used function of back-channel was request for clarification. The results of this thesis will provide language teachers, EFL language learners, researchers, material developers, and readers, useful information about the types and functions of back channels that are needed to develop speaking ability appropriately through explicit teaching.Keywords: back channel strategy, communication strategy, explicit training

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Lee, Duck-Young, et Chiharu Mukai. « A study of Japanese back channels ». Issues in the Teaching and Learning of Japanese 15 (1 janvier 1998) : 77–92. http://dx.doi.org/10.1075/aralss.15.05lee.

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Abstract This study presents findings from an analysis of the conversational data involving the Japanese back channel with special attention to the comparison of back channel behaviour between Japanese native speakers and Japanese learners at an advanced level. While the analysis is based on four aspects of the back channel (i.e. form, frequency, location and function), the study reveals that native speakers and Japanese learners show significant differences particularly in the locational and functional aspects. There were also trends that the native speaker tends to use back channels in a way of supporting and encouraging the learner to participate in the conversation.

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Frizzell, Raymond A., et William H. Cliff. « Back to the chloride channel ». Nature 350, n^o 6316 (mars 1991) : 277–78. http://dx.doi.org/10.1038/350277a0.

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Zhang, Ying, Haiting Xie et Chengyuan Dong. « Electrical Performance and Bias-Stress Stability of Amorphous InGaZnO Thin-Film Transistors with Buried-Channel Layers ». Micromachines 10, n^o 11 (14 novembre 2019) : 779. http://dx.doi.org/10.3390/mi10110779.

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To improve the electrical performance and bias-stress stability of amorphous InGaZnO thin-film transistors (a-IGZO TFTs), we fabricated and characterized buried-channel devices with multiple-stacked channel layers, i.e., a nitrogen-doped a-IGZO film (front-channel layer), a conventional a-IGZO film (buried-channel layer), and a nitrogen-doped a-IGZO film (back-channel layer). The larger field-effect mobility (5.8 cm2V−1s−1), the smaller subthreshold swing value (0.8 V/dec, and the better stability (smaller threshold voltage shifts during bias-stress and light illumination tests) were obtained for the buried-channel device relative to the conventional a-IGZO TFT. The specially designed channel-layer structure resulted in multiple conduction channels and hence large field-effect mobility. The in situ nitrogen-doping caused reductions in both the front-channel interface trap density and the density of deep states in the bulk channel layers, leading to a small subthreshold swing value. The better stability properties may be related to both the reduced trap states by nitrogen-doping and the passivation effect of the nitrogen-doped a-IGZO films at the device back channels.

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Xiao, Peng, Wenfeng Wang, Yingyi Ye, Ting Dong, Shengjin Yuan, Jiaxing Deng, Li Zhang, Jianwen Chen et Jian Yuan. « Back-Channel-Etched InGaZnO Thin-Film Transistors with Au Nanoparticles on the Back Channel Surface ». Electronic Materials Letters 16, n^o 2 (7 janvier 2020) : 115–22. http://dx.doi.org/10.1007/s13391-019-00189-w.

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Mukharji, Aroop, et Richard J. Zeckhauser. « Back Channel Negotiations and Dangerous Waiting ». Negotiation Journal 34, n^o 3 (juillet 2018) : 297–307. http://dx.doi.org/10.1111/nejo.12232.

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Sim, J. H., M. C. Tang et J. B. Kuo. « A fully analytical back-gate bias model for n-channel silicon MESFETs with back channel implant ». Solid-State Electronics 37, n^o 3 (mars 1994) : 459–62. http://dx.doi.org/10.1016/0038-1101(94)90012-4.

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Pan, Enhui, et Costa M. Colbert. « Subthreshold Inactivation of Na+ and K+Channels Supports Activity-Dependent Enhancement of Back-Propagating Action Potentials in Hippocampal CA1 ». Journal of Neurophysiology 85, n^o 2 (1 février 2001) : 1013–16. http://dx.doi.org/10.1152/jn.2001.85.2.1013.

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Back-propagating action potentials in CA1 pyramidal neurons may provide the postsynaptic dendritic depolarization necessary for the induction of long-term synaptic plasticity. The amplitudes of back-propagating action potentials are not all or none but are limited in amplitude by dendritic A-type K+ channels. Previous studies of back-propagating action potentials have suggested that prior depolarization of the dendritic membrane reduces A-type channel availability through inactivation, resulting in an enhanced, or boosted, dendritic action potential. However, inactivation kinetics in the subthreshold potential range have not been directly measured. Furthermore, the corresponding rates of Na+channel inactivation with depolarization have not been considered. Here we report in cell-attached patches (150–220 μm from the soma, 32°C) that at 20-mV positive to rest, A-type K+channels inactivated with a single exponential time constant of 6 ms, whereas Na+ channels inactivated with a time constant of 37 ms. The ratio of available Na+ to K+ current increased as the duration of the depolarization increased. Thus the subthreshold properties of Na+ and A-type K+ channels provide a mechanism by which information about the level of synaptic activity may be encoded in the amplitude of back-propagating action potentials.

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Pieterson, Willem, et Wolfgang Ebbers. « The use of service channels by citizens in the Netherlands : implications for multi-channel management ». International Review of Administrative Sciences 74, n^o 1 (mars 2008) : 95–110. http://dx.doi.org/10.1177/0020852307085736.

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Many governmental organizations are changing their service channel management strategies to multi-channel management. However, very few empirical studies exist that explore how these multi-channel strategies should be shaped. In this article we test a number of hypotheses on citizens' channel use behaviour and the determinants of this behaviour. Further, we take into account the differences between citizens with and without a personal computer. In our conclusions we call for multi-channel strategies that do not only incorporate the features of service channels and the front—back office integration, but also deal with personal characteristics and task characteristics. Further, digital divide issues still influence channel usage by citizens, so it is necessary to keep all channels open for citizens. Finally, our study reveals that multi-channelling is a very complex subject on which research is still in its infancy. Points for practitioners • Multi-channel management may benefit most from channel integration. • Channels have different characteristics that render them suitable for different (parts of) services. • Computer `have-nots' still rely on traditional service channels, so these should remain accessible.

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Bowley, Kate A., et Geoffrey I. Sandle. « Calmodulin Antagonist W-7 Enhances Intermediate Conductance Ca2+- Sensitive Basolateral Potassium Channel (IKCa) Activity in Human Colonic Crypts ». Journal of Membrane Biology 254, n^o 4 (27 juillet 2021) : 423–28. http://dx.doi.org/10.1007/s00232-021-00193-y.

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AbstractIntermediate conductance potassium (IKCa) channels are exquisitively Ca2+ sensitive, intracellular Ca2+ regulating channel activity by complexing with calmodulin (CaM), which is bound to the cytosolic carboxyl tail. Although CaM antagonists might be expected to decrease IKCa channel activity, the effect of W-7 in human T lymphocytes are conflicting. We therefore evaluated the effect of W-7 on basolateral IKCa channels in human colonic crypt cells. Intact crypts obtained from normal human colonic biopsies by Ca2+ chelation were used for patch clamp studies of basolateral IKCa channels in the cell-attached configuration. IKCa channel activity was studied when the bath Ca2+ concentration was changed from 1.2 mmol/L to 100 μmol/L and back to 1.2 mmol/L, as well as from 100 μmol/L to 1.2 mmol/L and back to 100 μmol/L, both in the absence and presence of 25 μmol/L W-7. Decreasing bath Ca2+ from 1.2 mmol/L to 100 μmol/L decreased IKCa channel activity reversibly in the absence of W-7, whereas there was a uniformly high level of channel activity at both bath Ca2+ concentrations in the presence of W-7. In separate experiments, increasing bath Ca2+ from 100 μmol/L to 1.2 mmol/L increased IKCa channel activity reversibly in the absence of W-7, whereas there was again a uniformly high level of channel activity at both bath Ca2+ concentrations in the presence of W-7. We, therefore, propose that W-7 has a specific stimulatory effect on basolateral IKCa channel activity, despite its ability to inhibit Ca2+/CaM-mediated, IKCa channel-dependent Cl− secretion in human colonic epithelial cells. Graphic Abstract

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Evatt, Geoffrey W. « Röthlisberger channels with finite ice depth and open channel flow ». Annals of Glaciology 56, n^o 70 (2015) : 45–50. http://dx.doi.org/10.3189/2015aog70a992.

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AbstractThe theoretical basis of subglacial channel dynamics can be traced back to the work of Röthlisberger (1972) and Nye (1953). Röthlisberger (1972) considered the channels’ behaviour to be governed by a mix between water friction melting back the channel walls and the viscous closure of the surrounding ice; Nye (1953) derived a viscous closure rate for the ice. While their modelling is evidently well constructed, two aspects of their work have gone undeveloped. The first is the consideration of a finite glacier depth within the viscous closure law, instead of the assumption of an infinite glacier depth. The second is the allowance of a region of open channel flow, so that a channel’s water may transition from a region of closed channel flow to one where the water is exposed to the atmosphere. This paper helps close these two gaps, showing how Nye’s equation for the rate of ice closure can be modified, and how the point of transition between closed and open channel flow may be determined.

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Wu, Ming Hsun, et Chien Mu Lai. « An Experimental Study to Determine the Optimal Sizes for Ball-Valve Micropump Channel ». Applied Mechanics and Materials 163 (avril 2012) : 100–106. http://dx.doi.org/10.4028/www.scientific.net/amm.163.100.

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The geometrical configurations of ball-valve micropumps have great influence on its efficiency. In particular, the ball valve channels have great influence on the efficiency of ball-valve micropumps because the prevention of backflow directly affects the performance of ball-valve micropumps.This study used water to investigate the optimal size of channels for piezoelectric ball-valve micropumps. The results show that the optimal angle for micro ball valve seats is 30°. The piezoelectric film vibrates rapidly and the back pressure in the water outlet channel is higher than it in the water inlet channel . This phenomenon indicates that channels are optimal sizes for a distance of 0 mm in the water inlet channel and 0.3mm in the water outlet channel.

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Ting, Chui Huon Tina, et Hieng Ho Lau. « Compression Test on Cold-Formed Steel Built-Up Back-to-Back Channels Stub Columns ». Advanced Materials Research 201-203 (février 2011) : 2900–2903. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2900.

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Built-up sections are used to resist load induced in a structure when a single section is not sufficient to carry the design load for example roof trusses. In current North American Specification, the provision has been substantially taken from research in hot-rolled built-up members connected with bolts or welds [1]. The aim of this paper is to investigate on built-up back-to-back channels stub columns experimentally and theoretically using Effective Width Method and Direct Strength Method. Compression test was performed on 5 lipped channel and 5 back-to-back channels stub columns fabricated from cold-formed steel sheets of 1.2mm thicknesses. The test results indicated that local buckling is the dominant failure modes of stub columns. Therefore, Effective Width Method predicts the capacity of stub columns compared to Direct Strength Method. When compared to the average test results, results based on EWM are 5% higher while results based on DSM are 12% higher for stub column.

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Jeon, Woojin, Pyungho Choi, Areum Park, Donghyeon Lee, Donghee Choi, Sangmin Lee et Byoungdeog Choi. « Solution-Based Indium–Zinc Oxide/Indium–Gallium–Zinc Oxide Double-Channel Thin-Film Transistors with Incorporated Hydrogen Peroxide ». Journal of Nanoscience and Nanotechnology 20, n^o 11 (1 novembre 2020) : 6643–47. http://dx.doi.org/10.1166/jnn.2020.18760.

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We fabricated and evaluated solution-based double-channel thin-film transistors (TFTs) that consisted of an indium–zinc oxide (IZO) front layer and an indium–gallium–zinc oxide (IGZO) back channel with the addition of hydrogen peroxide (H2O2). The devices showed superior electrical properties with regard to saturation mobility (12.9 cm2/V·s), the on-off ratio (5 × 107), and the subthreshold swing (0.21 V/decade). All the devices were subjected under bias and illumination stress for reliability assessment. The threshold voltage shift stability of positive and negative bias illumination stress under different wavelengths was also enhanced. Thus, we achieved improved performance using IZO/IGZO TFTs with back channels that incorporated H2O2.

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Djelti, Hamida. « Numerical investigation of the performance of AlGaN/GaN/BGaN double-gate double-channel high electron mobility transistor ». International Journal of Electrical and Computer Engineering (IJECE) 12, n^o 3 (1 juin 2022) : 2655. http://dx.doi.org/10.11591/ijece.v12i3.pp2655-2662.

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<p><span>In this work, we examine the direct-current (DC) behavior and the radio-frequency (RF) performance of both single-gate simple-channel (SGSC), single-gate double-channel (SGDC) and double-gate double-channel (DGDC) AlGaN/GaN/BGaN high electron mobility transistor (HEMT) with BGaN back-barriers consist of 250 nm gate length. Using Technologie Computer Aided Design (TCAD) Silvaco, our isothermal simulation results reveal that the proposed structure of double-gate double-channel HEMT with BGaN back-barriers (DGDCBB HEMT) increases electron concentration and consequently the saturation drain current, breakdown voltage, the transconductance. On the other hand, decreases the gate leakage current compared to a conventional HEMT and to a double-channel HEMT back-barriers. Furthermore, the proposed double-gate double-channel back-barrier HEMT device shows good cutoff frequency (94 GHz) and a maximum oscillation frequency (170 GHz). These results suggest that double-gate double channel HEMT back-barriers could be useful for high-frequency and high-power microwave applications.</span></p>

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Zhang, Rong, Jiatong Li, Zongsheng Huang et Bin Liu. « Return Strategies and Online Product Customization in a Dual-Channel Supply Chain ». Sustainability 11, n^o 12 (25 juin 2019) : 3482. http://dx.doi.org/10.3390/su11123482.

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This paper investigates in a dual-channel supply chain which return strategy is better for the manufacturer that considers the consumers’ utility. We find that a manufacturer prefers offering a Money-Back Guarantee (MBG) as long as the net salvage value of the returned product is positive in a channel. However, the return strategy of the retailer is more affected by the return policy of another channel than the net salvage value. In order to reduce online returns, we propose the online product customization channel, and then, we examine the choice of return policy and the manufacturer’s channel selection. We show that the demand and profit of the manufacturer will increase to a certain extent when opening an online customization channel. However, compared to the case where both channels provide an MBG, the implementation of online customization may hurt the manufacturer’s profits with the increase in consumer satisfaction in indirect channels.

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Johnston, Daniel, Brian R. Christie, Andreas Frick, Richard Gray, Dax A. Hoffman, Lalania K. Schexnayder, Shigeo Watanabe et Li-Lian Yuan. « Active dendrites, potassium channels and synaptic plasticity ». Philosophical Transactions of the Royal Society of London. Series B : Biological Sciences 358, n^o 1432 (29 avril 2003) : 667–74. http://dx.doi.org/10.1098/rstb.2002.1248.

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The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into the dendrites (back-propagation); calcium channels are responsible for local changes in dendritic calcium concentrations following back-propagating APs and synaptic potentials; and potassium channels help regulate overall dendritic excitability. Several lines of evidence are presented here to suggest that back-propagating APs, when coincident with excitatory synaptic input, can lead to the induction of either long-term depression (LTD) or long-term potentiation (LTP). The induction of LTD or LTP is correlated with the magnitude of the rise in intracellular calcium. When brief bursts of synaptic potentials are paired with postsynaptic APs in a theta-burst pairing paradigm, the induction of LTP is dependent on the invasion of the AP into the dendritic tree. The amplitude of the AP in the dendrites is dependent, in part, on the activity of a transient, A-type potassium channel that is expressed at high density in the dendrites and correlates with the induction of the LTP. Furthermore, during the expression phase of the LTP, there are local changes in dendritic excitability that may result from modulation of the functioning of this transient potassium channel. The results support the view that the active properties of dendrites play important roles in synaptic integration and synaptic plasticity of these neurons.

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Pruitt, Dean. « Back-channel Communication in the Settlement of Conflict ». International Negotiation 13, n^o 1 (2008) : 37–54. http://dx.doi.org/10.1163/138234008x297922.

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AbstractSecret back-channel communication is often employed in severe conflict to explore the feasibility of front-channel negotiation. It can also be used as an adjunct to front-channel negotiation when talks become deadlocked or as a substitute for front-channel negotiation. Its value lies partly in the flexibility and future orientation it brings to talks. In the prenegotiation phase, it also provides political cover, is cost-effective, does not require formal recognition of the adversary, and allows communication with adversaries who do not meet preconditions for negotiation such as a cease-fire. Intermediaries and intermediary chains are sometimes used in back-channel communication. Heavy reliance on back-channel communication can produce flimsy agreements that are too narrowly based or fail to deal with major issues. But this problem can be avoided if enough time is spent assembling a broad central coalition.

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Liu, Jiqiong, Minglun Ren, Aifeng Yang et Shuai Feng. « Money-Back Guarantee, Dual Money-Back Guarantee, and O2O Strategy in a Manufacturer’s Dual-Channel Supply Chain ». Mathematical Problems in Engineering 2020 (27 février 2020) : 1–21. http://dx.doi.org/10.1155/2020/1697082.

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Return services are increasingly valued by manufacturers, retailers, and customers. In many countries, an offer of money-back guarantee (MBG) is legally binding. In this paper, we discuss how a retailer and manufacturer with a direct channel should choose single or dual MBG and pricing strategies. We identify the conditions under which a retailer or manufacturer should choose a return strategy and show that the handling return loss and the customer return cost in each channel are critical factors that should be considered by the retailer and manufacturer when choosing a return strategy. In addition, the retailer should cooperate with the manufacturer to establish an offline-to-online (O2O) omnichannel to fully benefit from the convenience and advantages of the retail channel. We find that the adoption of the O2O strategy by the retailer in its retail channel always generates profits, while the manufacturer may implement the O2O strategy in its direct channel when the profit from the Internet service is higher than a threshold. Additionally, the impact of various strategies on pricing, market share, and profits is discussed.

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Liu, S. T., et L. P. Allen. « Back channel uniformity of thin SIMOX wafers ». IEEE Transactions on Nuclear Science 38, n^o 6 (1991) : 1271–75. http://dx.doi.org/10.1109/23.124104.

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Christie, B. R., L. S. Eliot, K. Ito, H. Miyakawa et D. Johnston. « Different Ca2+ channels in soma and dendrites of hippocampal pyramidal neurons mediate spike-induced Ca2+ influx ». Journal of Neurophysiology 73, n^o 6 (1 juin 1995) : 2553–57. http://dx.doi.org/10.1152/jn.1995.73.6.2553.

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1. Intracellular recordings, in conjunction with fura-2 fluorescence imaging, were used to evaluate the contribution of the different Ca2+ channel subtypes to the Ca2+ influx induced by back-propagating trains of action potentials. High-threshold channels contributed mainly to Ca2+ influx in pyramidal cell somata and proximal dendrites, whereas low-threshold and other Ni(2+)-sensitive channels played a greater role in more distal dendritic signaling. These data suggest that the different Ca2+ channel types participate in distinct physiological functions; low-threshold channels likely play a greater role in dendritic integration, whereas high-threshold channels are more important for somatic Ca(2+)-dependent processes.

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Afshari, S., L. Moynihan et S. Mishra. « An optimisation toolbox for multi-colour LED lighting ». Lighting Research & ; Technology 50, n^o 3 (7 octobre 2016) : 467–81. http://dx.doi.org/10.1177/1477153516669881.

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This paper introduces a software toolbox designed for the optimisation of white light generation using multiple light-emitting diode (LED) channels. The toolbox solves two separate types of multi-colour optimisation problems. These are the multi-channel mixing and the channel choice problems. In the multi-channel mixing problem, it is assumed that the available LEDs are pre-determined and fixed. The toolbox obtains the individual channel intensities that solve a constrained optimisation problem based on the mixed output light. It provides the user with the flexibility to choose an arbitrary formulation for the optimisation problem as well as various mathematical metrics to represent the different properties of the output light including colour rendering, power efficiency and colour accuracy. For the channel choice problem, the toolbox solves for the number and type of used LED channels as well as the intensity of individual channels to assist in optimal choice of deployed channels for luminaire manufacturing applications. This paper describes the graphical user interface and the back-end formulation of the optimisation problem and presents experimental results obtained by utilising the toolbox in a full-size conference room with 5-channel LED luminaires.

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Bacci, Giacomo, Marco Della Maggiora et Marco Luise. « Iterative Channel Estimation for Nonbinary LDPC-Coded OFDM Signals ». ISRN Signal Processing 2011 (14 avril 2011) : 1–8. http://dx.doi.org/10.5402/2011/254597.

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This work deals with the issue of channel estimation in the context of non-binary LDPC-coded OFDM systems over doubly selective multipath channels. In particular, we show how to derive an iterative Wiener-filter-based estimation method using both time and frequency channel correlation and considering the particular characteristics of the channel code. The proposed algorithm can use either soft information or hard decisions fed back by the decoder to refine the channel estimation, so as to improve the system performance at the expense of an increased receiver complexity. Simulation results under typical working conditions are presented to compare the performance of the proposed method with respect to classical techniques.

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Hibino, Hiroshi, Atsushi Inanobe, Kazuharu Furutani, Shingo Murakami, Ian Findlay et Yoshihisa Kurachi. « Inwardly Rectifying Potassium Channels : Their Structure, Function, and Physiological Roles ». Physiological Reviews 90, n^o 1 (janvier 2010) : 291–366. http://dx.doi.org/10.1152/physrev.00021.2009.

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Inwardly rectifying K+(Kir) channels allow K+to move more easily into rather than out of the cell. They have diverse physiological functions depending on their type and their location. There are seven Kir channel subfamilies that can be classified into four functional groups: classical Kir channels (Kir2.x) are constitutively active, G protein-gated Kir channels (Kir3.x) are regulated by G protein-coupled receptors, ATP-sensitive K+channels (Kir6.x) are tightly linked to cellular metabolism, and K+transport channels (Kir1.x, Kir4.x, Kir5.x, and Kir7.x). Inward rectification results from pore block by intracellular substances such as Mg2+and polyamines. Kir channel activity can be modulated by ions, phospholipids, and binding proteins. The basic building block of a Kir channel is made up of two transmembrane helices with cytoplasmic NH2and COOH termini and an extracellular loop which folds back to form the pore-lining ion selectivity filter. In vivo, functional Kir channels are composed of four such subunits which are either homo- or heterotetramers. Gene targeting and genetic analysis have linked Kir channel dysfunction to diverse pathologies. The crystal structure of different Kir channels is opening the way to understanding the structure-function relationships of this simple but diverse ion channel family.

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Kusche, Roman, Jan Graßhoff, Andra Oltmann, Lukas Boudnik et Philipp Rostalski. « A Robust Multi-Channel EMG System for Lower Back and Abdominal Muscles Training ». Current Directions in Biomedical Engineering 7, n^o 2 (1 octobre 2021) : 159–62. http://dx.doi.org/10.1515/cdbme-2021-2041.

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Abstract EMG is an established method to acquire the action potentials of contracted muscles. Although commercial EMG systems are available and it is one of the most researched biosignals, it has never become widely used in rehabilitation or fitness training monitoring. The reasons are technical challenges of wearable EMG systems regarding electrode placement, motion artefacts and the complex connectivity of multi-channel EMG measurements. We address this problem for the lower back and abdominal musculature, through a novel dry electrodes belt, multi-channel high density EMG circuitry and problem-specific signal processing. The subject can easily strap the dry electrodes belt around himself which provides 16 EMG channels. Interferences from the ECG and motion artefacts are reduced by a stationary wavelet decomposition. Afterwards, an inter-channel filter is applied to increase the robustness of the signals. Subject measurements during different kinds of typical abdominal and lower back training exercises were performed wearing the novel dry electrodes belt. The results show the possibility of robust EMG measurements from the lower back and abdominal muscles by utilizing the gathered redundancy, appropriately. The additional information obtained via the multi-channel EMG circuitry and spatial oversampling can be used to address current problems of EMG applications. It combines the advantages of robustness and the capability of using comfortable dry electrodes. Therefore, the proposed measurement method for acquiring spatial information about the muscle contractions from the lower trunk can be used for rehabilitation or fitness training monitoring.

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N, Reshma, et T. K. Ramesh. « Underwater channel design for diver communication ». International Journal of Engineering & ; Technology 7, n^o 1.8 (28 février 2018) : 214. http://dx.doi.org/10.14419/ijet.v7i1.9352.

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Underwater channels are usually considered to be very difficult media for communication purposes. There are many reasons that pull back us from considering these types of channels for communication purposes. Limited bandwidth, Doppler effect, multipath propagation etc are some of those reasons. These reasons limit the usage of underwater channel for wide range of applications.Optical waves, RF waves and acoustic waves are generally used. Among the methods, acoustic waves are used in most of the cases since less attenuation and scattering properties are offered by acoustic waves. There are many acoustic channel models existing but require some improvisations according to the diving application. An efficient acoustic underwater channel for diver communication is designed and implemented in this paper. Rayleigh channel model is considered in our algorithm that can deal with multipath propagation and Doppler effect with underwater specifications incorporated to it.This method gives a better result compared to OFDM and MIMO models. Further, a comparison between different modulation techniques like ASK, BPSK and QAM have been done. Results show QAM is a better modulation scheme for underwater environment.

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Menahem, Jonathan, et Dror Malka. « A Two-Channel Silicon Nitride Multimode Interference Coupler with Low Back Reflection ». Applied Sciences 12, n^o 22 (21 novembre 2022) : 11812. http://dx.doi.org/10.3390/app122211812.

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Optical communication systems based on silicon (Si) multimode interference (MMI) wavelength-division multiplexing (WDM) technology can suffer from back reflection. This undesirable characteristic causes losses and is a key problem that can lead to performance limitations. To overcome this limitation, we proposed a new study on how to divide two wavelengths by understanding the light coupling mechanism of the silicon nitride (SiN) MMI coupler over the C-band window and showed four different options to design a two-channel demultiplexer. The best option for a two-channel SiN MMI coupler with low back reflection losses operating in the C-band spectrum was selected. Based on simulation results, the proposed device can transmit two channels with a spacing of 20 nm between wavelengths in the C-band. Moreover, the device has a low power loss range of 0.895–0.936 dB, large bandwidth of 16.96–18.77 nm, and good crosstalk of 23.5–25.86 dB. Usually, a unique design such as angled MMI is required when using Si MMI technology to reduce the back reflection losses. Due to the use of SiN, which has a low refractive index, we obtained a 40.4 dB back-reflection loss without using this angled MMI design. Therefore, this MMI demultiplexer based on SiN can be used in optical communication systems based on the WDM technique to obtain a high data transfer rate in conjunction with low back-reflection losses.

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Saraswat, Kriti, Ajit Kumar Shrivastava et Amit Saxena. « OPTIMIZATION OF CHANNEL ALLOCATION ALGORITHM FOR HOT SPOT CELLS IN WIRELESS NETWORKS ». INTERNATIONAL JOURNAL OF COMPUTERS & ; TECHNOLOGY 3, n^o 2 (30 octobre 2012) : 238–41. http://dx.doi.org/10.24297/ijct.v3i2a.2813.

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Dense deployment of cellular networks is leading to scarcity of communication bandwidth or what we call as channel. If compared to its wired counterparts, wireless cellular network have limited number of channels available, which gives rise to problem of efficient channel allocation. Here, in this piece of work, the main objective is to put an effort to improve existing channel allocation scheme. In earlier existing hybrid allocation scheme, the base station notifies about the hot-spots to the Mobile Switching Centre (MSC) and if MSC has available channels in its central pool then it satisfies the request. Now, the novelty of this work starts where central pool gets exhausted and request of channels from base station (BS) still arrives and is served by returning the unused channels by different cells back to MSC on its request. The simulation of this approach is expounded and evaluated over OMNeT++ in a scenario with fixed channel allocation and hybrid approach by varying the proportion of dynamic channels to total number of channels available and the effectiveness is evaluated in terms of Call blocked and Call dropped versus System load.

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HARA, MASAHIRO, AKIRA ENDO, SHINGO KATSUMOTO et YASUHIRO IYE. « SUPPRESSION OF BACKSCATTERING IN QUANTUM HALL NARROW CHANNEL UNDER TRANSVERSALLY MODULATED MAGNETIC FIELD ». International Journal of Modern Physics B 18, n^o 27n29 (30 novembre 2004) : 3563–68. http://dx.doi.org/10.1142/s0217979204027025.

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We have studied transport in a narrow Hall bar subjected to a transversally modulated magnetic field in quantum Hall regime. Landau level spatially varies across the channel and suppresses back scattering between oppositely directed edge channels. The resistance suppressed by the "magnetic barrier" recovers with increasing temperature, showing thermally activated temperature dependence.

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Almohammedi, Akram A., Nor K. Noordin, A. Sali, Fazirulhisyam Hashim, Waheb A. Jabbar et Sabri Saeed. « Modeling and analysis of IEEE 1609.4 MAC in the presence of error-prone channels ». International Journal of Electrical and Computer Engineering (IJECE) 9, n^o 5 (1 octobre 2019) : 3531. http://dx.doi.org/10.11591/ijece.v9i5.pp3531-3541.

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Vehicular Ad Hoc Networks (VANETs) have been developed to improve the safety, comfort and efficiency of driving on the road. The IEEE 1609.4 is a standard intended to support multi-channel in VANETs. These channels include one control channel for safety applications and six service channels for service applications. However, there is still no comprehensive analysis for the average delay and system throughput of IEEE 1609.4 MAC in VANETs considering error-prone channel under non-saturated conditions. In this paper, we propose an analytical models based on 1-D and 2-D Markov chain to evaluate the performance analysis of IEEE 1609.4 MAC in the presence of error-prone channels. Besides, freezing of the back-off timer is taken into consideration to provide an accurate estimation of access to the channel. The simulation results have been carried out to validate the analytical results of our model. The results show that the performance of our model outperforms the existing model in terms of packet delivery ratio and average delay of safety packets over CCH, and system throughput of service packets over SCHs.

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Vieira, M., M. A. Vieira, V. Silva, P. Louro et J. Costa. « SiC monolithically integrated wavelength selector with 4 channels ». MRS Proceedings 1536 (2013) : 79–84. http://dx.doi.org/10.1557/opl.2013.728.

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ABSTRACTIn this paper we present a monolithically integrated wavelength selector based on a double pin/pin a-SiC:H integrated optical active filter that requires optical switches to select visible wavelengths. Red, green, blue and violet pulsed communication channels are transmitted together, each one with a specific bit sequence. The combined optical signal is analyzed by reading out the generated photocurrent, under violet (400 nm) background applied either from the front or the back side of the device. The front and back backgrounds acts as channel selectors that selects one or more channels by splitting portions of the input multi-channel optical signals across the front and the back photodiodes. The transfer characteristics effects due to changes irradiation side are presented. The relationship between the optical inputs and the corresponding digital output levels is established through a 16-element look-up table to perform the optoelectronic conversion.Results show that the wavelength selector acts as a reconfigurable active filter that enhances the spectral sensitivity in a specific wavelength range and quenched it in the others, tuning a specific band. A binary weighted RGBV code that takes into account the specific weights assigned to each bit position is presented and establishes the optoelectronic functions.

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Mollaabbasi, R., et S. M. Taghavi. « Buoyant displacement flows in slightly non-uniform channels ». Journal of Fluid Mechanics 795 (22 avril 2016) : 876–913. http://dx.doi.org/10.1017/jfm.2016.232.

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We consider displacement flows in slightly diverging or converging plane channels. The two fluids are miscible and buoyancy is significant. We assume that the channel is oriented close to horizontal. Employing a classical lubrication approximation, we simplify the governing equations to furnish a semi-analytical solution for the flux functions. Then, we demonstrate how the non-uniformity of the displacement flow geometry can affect the propagation of the interface between the heavy and light fluids in time, for various parameters studied, e.g. the viscosity ratio, a buoyancy number and rheological features. By setting the molecular diffusion effects to zero, certain solution behaviours at longer times can be practically predicted through the associated hyperbolic problem, using which it becomes possible to directly compute the interfacial features of interest, e.g. leading and trailing front heights and speeds. For a Newtonian displacement flow in a converging or uniform channel, as the buoyancy number increases from zero, we are able to classify three flow regimes based on the behaviour of the trailing front near the top of the channel: a no-back-flow regime, a stationary interface flow regime, and a sustained back-flow regime. For the case of a diverging channel flow, the sustained back-flow regime is replaced by an eventually stationary interface flow regime. In addition, as the displacement flow progresses, the leading front speed typically increases (decreases) in a converging (diverging) channel, while the opposite is usually true for the front height. For the no-back-flow regime (i.e. with small buoyancy), the solution of the displacement flow at long times in all the geometries considered converges to a similarity form, while no similarity form is found for the other flow regimes. As the displacement flow develops, frontal diffusive effects are reduced (enhanced) in a converging (diverging) channel and multiple fronts are progressively less (more) present in a converging (diverging) channel. Regarding non-Newtonian effects, a shear-thinning fluid displacing a Newtonian fluid exhibits an increasingly fast front that has a short height in a converging channel. When a yield stress is present in the displaced fluid, it is possible to find residual wall layers of displaced fluid that are completely static. These layers disappear at a certain critical downstream distance in a converging channel while they appear at a critical distance in a diverging channel. Finally, the combination of strong buoyant and yield-stress effects can modify the destiny of a second front that follows the leading front.

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Dochartaigh, Niall Ó. « Together in the middle : Back-channel negotiation in the Irish peace process ». Journal of Peace Research 48, n^o 6 (novembre 2011) : 767–80. http://dx.doi.org/10.1177/0022343311417982.

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This article examines the development of cooperative relationships in back-channel communication and their impact on intraparty negotiation. It draws on extensive newly available evidence on back-channel communication in the Irish peace process to expand the range of detailed case studies on a topic which is shrouded in secrecy and resistant to academic inquiry. The article analyses the operation of a secret back channel that linked the Irish Republican Army to the British government over a period of 20 years, drawing on unique material from the private papers of the intermediary, Brendan Duddy, and a range of other primary sources. The article finds that interaction through this back channel increased predictability and laid a foundation of extremely limited trust by providing information and increasing mutual understanding. Strong cooperative relationships developed at the intersection between the two sides, based to a great extent on strong interpersonal relationships and continuity in personnel. This in turn produced direct pressure for changes in the position of parties as negotiators acted as advocates of movement in intraparty negotiations. The article finds that this back channel was characterized by a short chain, the direct involvement of principals and the establishment of a single primary channel of communication and that these features combined with secrecy to generate the distinctive cooperative dynamics identified in this article. It concludes that the potential for the development of cooperative relationships is particularly strong in back-channel negotiation for two reasons; first, the joint project of secrecy creates an ongoing shared task that builds trust and mutual understanding regardless of progress in the negotiations. Secondly, as a shared project based on the explicit aim of bypassing spoilers, the process creates structural pressures for cooperation to manage internal opponents on both sides, pressures intensified by the secrecy of the process.

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Lakshminarayanan, V., P. Karthikeyan, M. Muthukumar, A. P. Senthil Kumar, B. Kavin et A. Kavyaraj. « Numerical Investigation of Performance Studies on Single Pass PEM Fuel Cell with Various Flow Channel Design ». Applied Mechanics and Materials 592-594 (juillet 2014) : 1672–76. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1672.

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The Proton Exchange Membrane (PEM) Fuel Cell performance not only depends on the operating parameters like temperature, pressure, the stoichiometric ratio of reactants, relative humidity and back pressure on anode and cathode flow channels, but it also depends on design parameters like channel width to rib width, channel depth and number of passes on the flow channel. In this paper numerical analysis were carried out with six different cross-sections of the channel, namely square, triangle, parallelogram 14o, parallelogram 26o, trapezium and inverted trapezium of 1.25 cm2active area with a constant cross sectional area of 0.01 cm2of single pass PEM fuel cell. The model was created and simulated under various pressures and temperature with a constant mass flow rate by using fluent CFD and the influence of the single pass flow channel on the performance of PEM fuel cell has been investigated.

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Takechi, Kazushige, Naoto Hirano, Hiroshi Hayama et Setsuo Kaneko. « Back-channel-oxidized a-Si:H thin-film transistors ». Journal of Applied Physics 84, n^o 7 (octobre 1998) : 3993–99. http://dx.doi.org/10.1063/1.368579.

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Shannon, J. M., et E. G. Gerstner. « Compensated back-channel TFTs in hydrogenated amorphous silicon ». IEEE Electron Device Letters 24, n^o 1 (janvier 2003) : 25–27. http://dx.doi.org/10.1109/led.2002.807017.

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Miyazaki, T., J. A. Plumb, Y. P. Li et R. T. Lovell. « Histopathology of broken-back syndrome in channel catfish ». Journal of Fish Biology 26, n^o 6 (juin 1985) : 647–55. http://dx.doi.org/10.1111/j.1095-8649.1985.tb04305.x.

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Wanis-St. John, Anthony. « Back-Channel Negotiation : International Bargaining in the Shadows ». Negotiation Journal 22, n^o 2 (avril 2006) : 119–44. http://dx.doi.org/10.1111/j.1571-9979.2006.00091.x.

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Nomura, Kenji. « 8‐3 : Invited Paper : Back‐Channel Defect Termination for p‐Channel Oxide‐TFTs ». SID Symposium Digest of Technical Papers 52, n^o 1 (mai 2021) : 85–88. http://dx.doi.org/10.1002/sdtp.14616.

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Chang, Hsuan, Chi-Hsin Huang, Kosuke Matsuzaki et Kenji Nomura. « Back-Channel Defect Termination by Sulfur for p-Channel Cu2O Thin-Film Transistors ». ACS Applied Materials & ; Interfaces 12, n^o 46 (4 novembre 2020) : 51581–88. http://dx.doi.org/10.1021/acsami.0c11534.

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Zhu, Zhen, et Junhao Chu. « A channel-potential-based surface potential model and a turn-on DC channel-potential-based drain current model for fully-depleted poly-Si thin film transistors including tail and deep acceptor-like trap states in bulk ». Modern Physics Letters B 34, n^o 02 (6 décembre 2019) : 2050023. http://dx.doi.org/10.1142/s0217984920500232.

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For fully-depleted polycrystalline silicon thin film transistors including both tail and deep acceptor-like trap states in the bulk and interface charges, a channel-potential-based surface potential model (including front and back surface potential) and a turn-on DC channel-potential-based drain current model are proposed with the effect of the back surface potential considered. Firstly, a channel-potential-based surface potential model is obtained by introducing a channel-potential-based front and back surface potential equation and a channel-potential-based equation describing the coupling effect of the front and back surface potential. Contributions of active acceptors, electrons and trapped charges are all taken into account in this coupling effect. Moreover, by integrating the electron concentration, vertically to the front poly-Si/oxide interface, in the inversion layer, using the average electric field concept and considering the effect of channel potential in the potential of the inversion layer’s ending point, the areal density of the inversion charge is deduced. Furthermore, a channel-potential-based drain current model, avoiding the double numerical integration, is developed with the merit of relative simplification in calculation. By using recursive Simpson rules, this drain current model is calculated by numerical integration with the examining condition. And the above proposed models are verified by 2D-device simulation from MEDICI.

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Lu, Shijun, Ruru Deng, Yeheng Liang, Longhai Xiong, Xianjun Ai et Yan Qin. « Remote Sensing Retrieval of Total Phosphorus in the Pearl River Channels Based on the GF-1 Remote Sensing Data ». Remote Sensing 12, n^o 9 (30 avril 2020) : 1420. http://dx.doi.org/10.3390/rs12091420.

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Total phosphorus (TP) concentration is one of the indicators for surface water quality evaluation. In this study, an indirect algorithm was proposed to retrieve TP concentration. This algorithm retrieves the TP concentration in urban waters based on Gaofen-1 (GF-1) remote sensing data. The algorithm uses the correlation between remote-sensing reflectance, optically significant constituents of water (chlorophyll, suspended sediment, and organic matter (excluding algae)), and TP to establish a retrieval model. First, the concentrations of optically active components are retrieved using a semi-analytical model. Second, the correlation between TP and optically active components is used to retrieve the TP concentration in waters. The GF-1 remote sensing data for 7 August 2015 were used to perform remote sensing retrieval of TP concentration in the Pearl River channels in Guangzhou, China. The results show that the TP concentration in most areas of the Front Channel, Western Channel, Guangzhou Channel, and the western part of the Back Channel was higher than 0.2 mg/L, while the TP concentration in the middle and eastern parts of the Back Channel was generally lower than 0.2 mg/L. The mean absolute percentage error of the retrieval is 24.18%. The experimental results show that the model is suitable for remote sensing retrieval of TP in urban waters in Guangzhou.

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Dan, Wen Jiao, Wei Gang Zhang et Shu Hui Li. « Investigation on the TRIP Steel Sheet Forming Processes with Respect to Punch Speed Loading-Paths ». Advanced Materials Research 154-155 (octobre 2010) : 667–73. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.667.

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Loading path is one of importance factors that influence the formability of sheet forming process. In this study, the effect of punching speed loading paths (PSLP) on forming and spring-back processes of TRIP (transformation induced plasticity) steel has been investigated. Four kinds of loading paths with three punch speeds are introduced to verify the cup drawing and U-channel spring-back processes based on a constitutive model accompanying the strain-induced martensite transformation. The results show that higher punch speed results in the thickness uniformity of drawing cup and the spring-back angle of stamping U-channel increased with the same loading path. Furthermore, a given loading path (C4) not only increases the minimum thickness of cup but also decreases the spring-back angle of U-channel.

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De Bellis, Michela, Brigida Boccanegra, Alessandro Giovanni Cerchiara, Paola Imbrici et Annamaria De Luca. « Blockers of Skeletal Muscle Nav1.4 Channels : From Therapy of Myotonic Syndrome to Molecular Determinants of Pharmacological Action and Back ». International Journal of Molecular Sciences 24, n^o 1 (3 janvier 2023) : 857. http://dx.doi.org/10.3390/ijms24010857.

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The voltage-gated sodium channels represent an important target for drug discovery since a large number of physiological processes are regulated by these channels. In several excitability disorders, including epilepsy, cardiac arrhythmias, chronic pain, and non-dystrophic myotonia, blockers of voltage-gated sodium channels are clinically used. Myotonia is a skeletal muscle condition characterized by the over-excitability of the sarcolemma, resulting in delayed relaxation after contraction and muscle stiffness. The therapeutic management of this disorder relies on mexiletine and other sodium channel blockers, which are not selective for the Nav1.4 skeletal muscle sodium channel isoform. Hence, the importance of deepening the knowledge of molecular requirements for developing more potent and use-dependent drugs acting on Nav1.4. Here, we review the available treatment options for non-dystrophic myotonia and the structure–activity relationship studies performed in our laboratory with a focus on new compounds with potential antimyotonic activity.

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Zhang, Shi Wei, Zhen Ping Wan, Yu Qin Shen, Yuan Xian Ou et Yong Tang. « Fabrication of Graphite Composite Bipolar Plate for Miniature PEMFCs by Micro Planing with Multi-Cutter ». Key Engineering Materials 589-590 (octobre 2013) : 617–22. http://dx.doi.org/10.4028/www.scientific.net/kem.589-590.617.

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This study explores the feasibility of using a novel process, micro planing with multi-cutter, to fabricate graphite composite bipolar plates of proton exchange membrane fuel cells (PEMFCs). Through the use of multi-cutter, this study succeeds in machining micro flow channels with dimensions of 0.2 mm×0.23 mm×0.4 mm (channel width × rib width × depth size) on graphite composite bipolar plate (21 mm × 80 mm × 1.5 mm), in a reaction area of 10 mm × 60 mm. The graphite composite plates fabricated by multi-cutter are tested for cell performance under varying back-pressures. Results show that the cell performance increase with the rising back-pressures and can be promoted apparently by decreasing the size of flow channels.

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Wang, Ning, Jin Zhou, Yu Pan et Hui Wang. « Density Wave Instability of Supercritical Kerosene in Active Cooling Channels of Scramjets ». Applied Mechanics and Materials 321-324 (juin 2013) : 293–98. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.293.

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Experimental investigations were made on the instability of supercritical kerosene flowing in active cooling channels. Two approaches were used to control the pressure in the channel. One is the back-pressure valve while the other is the venturi. In both conditions, a kind of low-frequency oscillation of pressure and temperature is observed. And the oscillation periods are calculated. By comparison with the flow time, it is concluded that the instability occurred in active cooling channels is probably one kind of density wave instability. And its period has no relationship with the cooling channel geometry, nor the pressure, but only depends on the flow time of kerosene in active cooling channels. When the mass flow rate, density and pressure drop couple with each other, the density wave instability will appear.

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Lin, Wei-Tse, Wen-Chia Liao, Yi-Nan Zhong et Yue-ming Hsin. « AlGaN/GaN HEMTs with 2DHG Back Gate Control ». MRS Advances 3, n^o 3 (26 décembre 2017) : 137–41. http://dx.doi.org/10.1557/adv.2017.619.

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ABSTRACTIn this study, AlGaN/GaN high electron mobility transistors (HEMTs) with a two-dimensional hole gas (2DHG) were investigated. In addition to a two-dimensional electron gas (2DEG) formed at the interface of the AlGaN and GaN layers for being a channel, a 2DHG was designed and formed underneath the channel to be the back gate. The simulated results showed the operation of device can be depletion-mode and enhancement-mode by adjusting the back gate bias. The fabricated devices showed the feasibility of 2DHG back gate control.

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Gurupatham, Beulah Gnana Ananthi, Krishanu Roy, Gary M. Raftery et James Boon Piang Lim. « Influence of Intermediate Stiffeners on Axial Capacity of Thin-Walled Built-Up Open and Closed Channel Section Columns ». Buildings 12, n^o 8 (22 juillet 2022) : 1071. http://dx.doi.org/10.3390/buildings12081071.

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This paper investigates the post-buckling behaviour and axial capacity of thin-walled steel stiffened single-channel sections (ISSCS) and back-to-back stiffened channel sections (BISCS). BISCS were connected using fasteners at a spacing of 200 mm and with an edge distance of 100 mm. Under axial compression, 10 new ISSCS and BISCS columns with fixed-ended conditions were tested. In the experimental tests, the back-to-back channel sections failed due to a combination of local and global buckling, whereas the single-channel sections generally failed as a result of local buckling. The behaviour of both ISSCS and BISCS shows a 20% increase on an average in axial capacity through adding stiffeners at the junction of the flange and the web, in addition to stiffeners in the web. A nonlinear finite element model (FEM) with material and geometric nonlinearities was then developed. The FE model was validated against the experimental results. A comprehensive parametric study comprising 64 face-to-face intermediate stiffened channel sections (FISCS) was then conducted to study the influence of stiffener length on its axial capacity. The axial capacity obtained from the tests and FEA shows that design in accordance with the Direct Strength Method (DSM) is accurate and conservative by only 4% on average.

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