Journal articles on the topic 'Channel modelling'
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Luchi, Rossella, Guido Zolezzi, and Marco Tubino. "Modelling mid-channel bars in meandering channels." Earth Surface Processes and Landforms 35, no. 8 (April 28, 2010): 902–17. http://dx.doi.org/10.1002/esp.1947.
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Bondar, O. I., O. I. Glukhenky, Yu M. Goryslavets, and O. P. Zapadynchuk. "NUMERICAL MODELLING OF INDUCTION CHANNEL FURNACE THERMAL STATE." Tekhnichna Elektrodynamika 2021, no. 3 (April 19, 2021): 44–49. http://dx.doi.org/10.15407/techned2021.03.044.
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A mathematical model that describes heat and mass transfer processes in an induction channel furnace is presented. Using the example of a two-phase channel furnace with standard form of channels, the influence of the phase angle between the voltages supplying the furnace inductors on the thermal state of the liquid metal is considered. Values of this angle, which provide minimal melt overheating in channels in comparison with furnace bath have been determined. Ways of intensification of heat and mass transfer processes in two-phase channel furnace have been suggested. References 9, figures 4.
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Wang, Xiaoyu, Xiaohua Wang, Rongkun Jiang, Weijiang Wang, Qu Chen, and Xinghua Wang. "Channel Modelling and Estimation for Shallow Underwater Acoustic OFDM Communication via Simulation Platform." Applied Sciences 9, no. 3 (January 28, 2019): 447. http://dx.doi.org/10.3390/app9030447.
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The performance of underwater acoustic (UWA) communication is heavily dependent on channel estimation, which is predominantly researched by simulating UWA channels modelled in complex and dynamic underwater environments. In UWA channels modelling, the measurement-based approach provides an accurate method. However, acquirement of environment data and simulation processes are scenario-specific and thus not cost-effective. To overcome such restraints, this article proposes a comprehensive simulation platform that combines UWA channel modelling with orthogonal frequency division multiplexing (OFDM) channel estimation, allowing users to model UWA channels for different ocean environments and simulate channel estimation with configurable input parameters. Based on the simulation platform, three independent
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Chatila, Jean G., and Ron D. Townsend. "Modelling floodplain conveyance in compound channel flows." Canadian Journal of Civil Engineering 22, no. 4 (August 1, 1995): 660–67. http://dx.doi.org/10.1139/l95-078.
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Floodplain conveyance in compound channel flows is examined through applications of the dynamic flow routing model DWOPER to both laboratory and field data sets. Three different approaches regarding the modelling of off-channel storage are considered, namely, the single-channel approach and two interface-plane methods, which artificially separate main channel flows from floodplain flows, using (i) vertical and (ii) diagonal interface planes. The single-channel method, which views composite flow fields as single units without storage, produced significant differences between simulated and observed stage and discharge hydrographs. The vertical interface method gave generally good results in the case of the laboratory data, but was less successful when applied to the field data. The diagonal interface method, which in this instance applied outward-facing diagonal interface planes at the junctions of the main channel and floodplain zones, produced superior results overall. Key words: floodplain, conveyance, unsteady flow, compound channels, off-channel storage, interface planes.
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Abida, Habib, and Ronald D. Townsend. "Parameter optimization in modelling unsteady compound channel flows." Canadian Journal of Civil Engineering 19, no. 3 (June 1, 1992): 441–46. http://dx.doi.org/10.1139/l92-053.
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Optimization methods are used to estimate data for routing floods through open compound channels (main channels with flood plain zones). These data include the irregular channel section geometry and the varying boundary roughness. Differences between simulated and observed stages and discharges are minimized using three optimization algorithms: Powell's method, Rosenbrock's algorithm, and the Nelder and Meade simplex method. Powells' method performed poorly; however, both the Rosenbrock and simplex methods yielded good results. The estimated data using the Rosenbrock and simplex methods were used to route different flood events observed in a laboratory channel. Simulated peak stages and discharges were in good agreement with those estimated using actual routing data. Key words: compound channel, flood routing, lateral momentum transfer, optimization, unsteady flow.
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Yang, Yi Huai. "Channel Modelling for WBANs." Applied Mechanics and Materials 246-247 (December 2012): 346–50. http://dx.doi.org/10.4028/www.scientific.net/amm.246-247.346.
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Development of an appropriate propagation channel model is an important step to design wireless body area network (WBAN). Because the human body has different body shapes (male, female and child), different tissues with different permittivity and conductivity (even the same person at the different age), and limbs positions and postures are changing all the time, this made the in-body channel modelling extremely difficult, if not impossible. There are few publications on implant communication channel models compared to wearable WBAN. In this paper, we present a literature survey on radio channel modelling for WBAN, especially the IEEE 802.15.6 models. The performance of the model is studied by simulating probability density functions (PDF) and cumulative distribution functions (CDF). Finally, we briefly outline some aspects of our future research works.
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Del Galdo, G., M. Haardt, and C. Schneider. "Geometry-based channel modelling of MIMO channels in comparison with channel sounder measurements." Advances in Radio Science 2 (May 27, 2005): 117–26. http://dx.doi.org/10.5194/ars-2-117-2004.
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Abstract. In this paper we propose a flexible geometrybased propagation model for wireless communications developed at Ilmenau University of Technology. The IlmProp comprises a geometrical representation of the environment surrounding the experiment and a precise representation of the transmitting and receiving antennas. The IlmProp is capable of simulating Multi-User MIMO scenarios and includes a complete collection of tools to analyze the synthetic channels. In order to assess the potentials as well as the limits of our channel simulator we reconstruct the scenario encountered in a recent measurement campaign at Ilmenau University of Technology leading to synthetic data sets similar to the ones actually measured. The measurements have been collected with the RUSK MIMO multi-dimensional channel sounder. From the comparisons of the two channel matrices it is possible to derive useful information to improve the model itself and to better understand the physical origins of small-scale fading. In particular the effects of the different parameters on the synthetic channel have been studied in order to assess the sensibility of the model. This analysis shows that the correct positioning of a small number of scatterers is enough to achieve frequency selectiveness as well as specific traits of the channel statistics. The size of the scattering clusters, the number of scatterers per cluster, and the Rician K-factor can be modified in order to tune the channel statistics at will. To obtain higher levels of time variance, moving scatterers or time dependent reflection coefficients must be introduced.
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Hu, Xiaojian, Shuai Feng, Jiqiong Liu, Aifeng Yang, Guanxiong Wang, and Hui Xu. "Return Mode Selection and Pricing Strategy for a Dual-Channel Retailer." Discrete Dynamics in Nature and Society 2020 (August 1, 2020): 1–20. http://dx.doi.org/10.1155/2020/5261486.
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With the rapid development of e-commerce and the economy, an increasing number of retailers are adopting a dual-channel retail strategy (DCRS), which allows customers to return unsatisfactory products, provided that their complaints are reasonable, and receive a full refund. This paper studies the pricing strategies of an integrated dual-channel retailer (DCR) when it provides return policies to customers, including original channel return, fixed cross-channel return, and relaxed cross-channel return. The relationship between the DCR’s system performance and channel pricing is impacted by customer channel preferences, and the return rates of different channels are discussed. The results show that the greater the difference in customer preferences between channels is, the greater the profitability of the DCR will be. A fixed cross-channel return model should be selected when the return rate in the online channel is higher or the cross-channel return rate is lower; otherwise, the original channel return model should be selected. When the return rate of a certain channel is high, the retailer should increase the price in that channel and reduce the pricing of its competing channel to compensate for the loss caused by the returns and transfer sales between channels. A selective return policy can not only improve the flexibility of business operations and enhance competitive advantage but also provide convenient customer returns and enhance consumers’ sense of security.
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Weng, Jialai, Xiaoming Tu, Zhihua Lai, Sana Salous, and Jie Zhang. "Indoor Massive MIMO Channel Modelling Using Ray-Launching Simulation." International Journal of Antennas and Propagation 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/279380.
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Massive multi-input multioutput (MIMO) is a promising technique for the next generation of wireless communication networks. In this paper, we focus on using the ray-launching based channel simulation to model massive MIMO channels. We propose one deterministic model and one statistical model for indoor massive MIMO channels, both based on ray-launching simulation. We further propose a simplified version for each model to improve computational efficiency. We simulate the models in indoor wireless network deployment environments and compare the simulation results with measurements. Analysis and comparison show that these ray-launching based simulation models are efficient and accurate for massive MIMO channel modelling, especially with application to indoor network planning and optimisation.
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Hewitt, Ian J. "Modelling distributed and channelized subglacial drainage: the spacing of channels." Journal of Glaciology 57, no. 202 (2011): 302–14. http://dx.doi.org/10.3189/002214311796405951.
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AbstractModels are proposed for channelized and distributed flow of meltwater at the base of an ice sheet. The volumes of both channel and distributed systems evolve according to a competition between processes that open drainage space (e.g. sliding over bedrock, melting of the ice) and processes that close it (e.g. viscous creep of the ice due to a positive effective pressure). Channels are generally predicted to have lower water pressure and therefore capture water from the surrounding regions of distributed flow. There is a natural length scale associated with the distributed system that determines the width of the bed from which water can be drawn into a channel. It is suggested that this determines the spacing between major channels and that this may be reflected in the spacing of eskers. A more permeable distributed system results in more widely spaced, and therefore larger, channels. Calculations of the flow into the head of a channel reveal that there is a critical discharge necessary for it to form, and provide a criterion for where channels can exist.
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Szwast, Maciej, and Zbigniew Szwast. "A Mathematical Model of Membrane Gas Separation with Energy Transfer by Molecules of Gas Flowing in a Channel to Molecules Penetrating this Channel from the Adjacent Channel." Chemical and Process Engineering 36, no. 2 (June 1, 2015): 151–69. http://dx.doi.org/10.1515/cpe-2015-0012.
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Abstract The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels - the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both - the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculations obtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.
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Sherlock, D., G. Weir, and K. Dodds. "ANALOG RESERVOIR MODELLING OF CHANNEL SANDS." APPEA Journal 45, no. 1 (2005): 439. http://dx.doi.org/10.1071/aj04034.
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This paper outlines the results of analog modelling of a sandy deepwater channel reservoir to gain insight into issues of uncertainty in reservoir simulations and their seismic expression. The project is unique in that it integrates seismic and reservoir engineering research in a controlled laboratory environment. Unlike numerical modelling investigations, this laboratory-based modelling study provides real data that does not rely on assumptions and is, therefore, a useful case study for comparing the actual production and seismic response against numerical predictions.The 1 m2 model comprised two intersecting synthetic sandstone channels within a transparent acrylic matrix. The model was initially oil-saturated with irreducible water and was produced through waterflooding of the upper channel. Careful attention was paid to scaling of both the fluid dynamics and the seismic properties to ensure that the response of the model was representative of the field-scale environment. Scaled time-lapse seismic data was recorded before and after production and data such as water cuts, recovery rates and pressure drop between injector and producers were also recorded.Analog reservoir modelling (ARM) provides a new tool that allows seismic attributes to be evaluated against ground truth results and the performance of seismic inversion schemes to be critically assessed.
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Bhattacharya, Subhajit. "Modelling channel partners’ opinions to achieve value-based relationship." Journal of Indian Business Research 11, no. 3 (August 19, 2019): 220–43. http://dx.doi.org/10.1108/jibr-04-2017-0037.
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PurposeThe present competitive marketing environment demands effective role of distribution channels to create and develop a value-based infrastructure where companies can easily distribute their products into the consumers’ market. Relationship bonding between the channel partners and the company strengthens marketing efficiencies of the distribution function, which is supported by policies of the companies relating to joint business actions and value sharing. Both the tangible functional value and emotional functionalities play a vital role in the continuous success and the growth of distribution channel. The purpose of this paper is to understand the value-based distribution channel relationship for greater channel equity in fast-moving consumer goods (FMCG) sector.Design/methodology/approachThe present study used a survey design to collect data from 156 FMCG channel members selected through stratified random sampling procedure. A five-point Likert-type scale was personally administered to obtain participants’ responses. Data were analysed using the Relative to an Identified Distribution (RIDIT) approach.FindingsThe findings of the current research paper have demonstrated that in the current competitive marketing environment, only the functional values are not enough. This research paper identifies that there is a strong need of emotional touch and linkages which leads to a symbiotic channel–company relationship and commitments in FMCG industry.Originality/valueThe present research is an original and innovative thought process of evaluating factors influencing the value-based distribution channel relationship for greater channel equity pertaining to FMCG industry by using the RIDIT approach.
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Tolj, Ivan, Zeljko Penga, Petar Bosnic, and Gojmir Radica. "Proton Exchange Membrane Fuel Cell Flow Field Configuration: Modelling and Experimental Verification." ECS Transactions 108, no. 7 (May 20, 2022): 143–51. http://dx.doi.org/10.1149/10807.0143ecst.
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Improper design of flow field channels may lead to water stagnation and flooding and may therefore lead to a poor fuel cell performance. The main purpose of this work is to investigate liquid water formation inside the flow field of the proton exchange membrane (PEM) fuel cell and to find optimal flow field configuration such as: number of channels, channel width to rib ratio and channel depth. To achieve this goal advanced numerical model of PEM fuel cell was developed. Model was simulated in Fluent, using computational fluid dynamics (CFD). Based on the obtained simulation results, graphite bipolar plate with optimal channel design was machined, integrated into the single PEM fuel cell unit, and experimentally tested.
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Long, Zhecheng. "Optical Wireless Systems Channel Modelling." Journal of Computer and Communications 10, no. 03 (2022): 66–85. http://dx.doi.org/10.4236/jcc.2022.103005.
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Wilson, R., S. O'Brien, D. Galaba, and J. Leighton. "Storage channel modelling in simulink." IEEE Transactions on Consumer Electronics 49, no. 1 (February 2003): 158–67. http://dx.doi.org/10.1109/tce.2003.1205470.
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Chen, Michael J., Yvonne M. Stokes, Peter Buchak, Darren G. Crowdy, and Heike Ebendorff-Heidepriem. "Microstructured optical fibre drawing with active channel pressurisation." Journal of Fluid Mechanics 783 (October 13, 2015): 137–65. http://dx.doi.org/10.1017/jfm.2015.570.
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The use of channel pressurisation in drawing microstructured optical fibres (MOFs) potentially allows for fine control of the internal structure of the fibre. By applying extra pressure inside the channels it is possible to counteract the effect of surface tension which would otherwise act to close the channels in the fibre as it is drawn. This paper extends the modelling approach of Stokes et al. (J. Fluid Mech., vol. 755, 2014, pp. 176–203) to include channel pressurisation. This approach treats the problem as two submodels for the flow, one in the axial direction along the fibre and another in the plane perpendicular to that direction. In the absence of channel pressurisation these models decoupled and were solved independently; we show that they become fully coupled when the internal channels are pressurised. The fundamental case of a fibre with an annular cross-section (containing one central channel) will be examined in detail. In doing this we consider both a forward problem to determine the shape of fibre from a known preform and an inverse problem to design a preform such that when drawn it will give a desired fibre geometry. Criteria on the pressure corresponding to fibre explosion and closure of the channel will be given that represent an improvement over similar criteria in the literature. A comparison between our model and a recent experiment is presented to demonstrate the effectiveness of the modelling approach. We make use of some recent work by Buchak et al. (J. Fluid Mech., vol. 778, 2015, pp. 5–38) to examine more complicated fibre geometries, where the cross-sectional shape of the internal channels is assumed to be elliptical and multiple channels are present. The examples presented here demonstrate the versatility of our modelling approach, where the subtleties of the interaction between surface tension and pressurisation can be revealed even for complex patterns of cross-sectional channels.
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Jaržemskis, Andrius. "THE MODELLING OF FACTORS DETERMINING THE GOODS AND TRAFFIC FLOWS MOVEMENT IN A LOGISTICAL SYSTEM." TRANSPORT 18, no. 1 (February 28, 2003): 18–22. http://dx.doi.org/10.3846/16483840.2003.10414058.
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The purpose of this atticle is to model the factors determining the goods traffic along the logistical channels located in various geopolitical regions on the basis of the transport network. The attention is focused on theoretical presumption of logistical channels formation in a logistical system. In this modeling the factors which determine the formation of the goods flow along the subsystems of the entire logistical system from the geopolitical point of view are defined. In this model the competitiveness of a logistical channel is determined by its technological, economical, legal characteristics as well as the length of the entire channel. The states, having the model provided, can evaluate the characteristics of the elements of the logistical channel and seek for the optimum ways to improve them. While planning the allocation of investments to improve the characteristics of separate elements of a logistical channel, it is a matter of utmost impmtance to consider the characteristics and their prospects of the entire logistical channel, a part of which stretches along the other states. It is very important for the Baltic States which are situated at the intersection of transit goods flows and logistical channels.
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Tolj, Ivan, Zeljko Penga, Petar Bosnic, and Gojmir Radica. "Proton Exchange Membrane Fuel Cell Flow Field Configuration: Modelling and Experimental Verification." ECS Meeting Abstracts MA2022-01, no. 35 (July 7, 2022): 1532. http://dx.doi.org/10.1149/ma2022-01351532mtgabs.
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With climate change crisis the research community is forced to consider other alternatives for energy production. Therefore, renewable energy sources are today considered as the main replacement for fossil fuels in the future. Proton exchange membrane (PEM) fuel cells are gaining more attention as main power sources for powering various vehicles, such as cars, forklifts, golfcarts etc. [1, 2]. European Commission (EC) recognized the importance of the fuel cell and hydrogen technology and their inevitable role in reducing greenhouse gas emission by further encouraging hydrogen fuel cell integration in various vehicles in their hydrogen strategy for a climate-neutral Europe [3]. Beside water and heat management, one of the key elements of the PEM fuel cells are reactants flow field channels. Influence of flow direction, channel length and number of channels, cross-section shape, channel depth, channel to rib width ratio etc., on PEM fuel cell performances has been analysed in the literature. Improper design of flow field channels may lead to water stagnation and flooding and as a result poor fuel cell performance (polarization curve). The objective of this work is to find optimal flow field configuration – number of channels, channel width to rib ration and channel depth. To achieve this objective numerical modelling of PEMFC was done using Ansys 17.0, in which 3D geometry (via DesignModeler) was modelled and finite volumes mesh was generated. Developed model was simulated in Fluent, using computational fluid dynamic (CFD). Based on the simulation results, graphite bipolar plate with optimal channel design was machined, integrated into single PEM fuel cell unit with commercial MEA’s and tested. With the application of different geometrical parameters like the number of channels, channel width to rib ratio, channel depth, mass fraction of oxygen and heat transfer in the fuel cell can be optimized. Numerical modelling of PEMFC was done using Ansys 17.0, in which 3D geometry (via DesignModeler) was modelled and finite volumes mesh was generated. At last, PEMFC was simulated in Fluent, using computational fluid dynamic (CFD). After calibration of the based numerical model, simulations with improved flow field designs were created and compared to the based model. Flow field design which was configurated as 4 serpentines (counterflow mode) channels with the depth of 0.45 mm, resulted in the best improvement of performance comparing to the basic model. Obtained results were confirmed experimentally. References Tolj, I.; Lototskyy, M.V.; Davids, M.W.; Pasupathi, S.; Swart, G.; Pollet B.G. Fuel cell-battery hybrid powered light electric vehicle (golf cart): Influence of fuel cell on the driving performance. J. Hydrogen Energy 2013, 38, 10630-10639. Lototskyy, M.V.; Tolj, I. et al. Performance of electric forklift with low-temperature polymer exchange membrane fuel cell power module and metal hydride hydrogen storage extension tank. Power Sources 2016, 316, 239-250. Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions: A hydrogen strategy for a climate-neutral Europe, Brussels, 08.07.2020, https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52020DC0301&from=EN
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Shokirov, B., B. Norkulov, Kh Nishanbaev, M. Khurazbaev, and B. Nazarov. "Computer simulation of channel processes." E3S Web of Conferences 97 (2019): 05012. http://dx.doi.org/10.1051/e3sconf/20199705012.
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The article discusses the results of numerical studies of flow movement with a sharp change in the channel parameters. The numerical study of the flow in the channels and rivers creates the possibility of a multivariate forecast of channel processes, rivers, and requires minimal expenditures. The purpose of the study is to determine the main objectives and directions of research in the area under consideration. A mathematical model and a computer program have been developed that allow solving a wide range of tasks for modelling currents in the channels of various difficulties, taking into account daily regulation. This makes it possible to identify and proactively take measures, such as: determining the time to reach the flow along the channel; the establishment of water volume flow in an arbitrary channel; taking emergency measures to regulate the incoming residual volume of water after its termination into the system, in the event of an accident at pumping stations; identification of the nature and direction of channel processes; prevention of undermining of supports and damage to power lines passing through the channel, and many other engineering tasks. The developed tested mathematical model allows in real conditions and in real time to help the operational services of large channels in the operational management of actions, in emergency situations, and the choice of the most effective, at any point in time, measures to minimize the consequences. Analysis of the results of many researchers has created the opportunity for the authors of this article to conclude that the above system of hydrodynamic equations is applicable in mathematical modelling of motion, taking into account the transverse circulation of the flow.
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Das, Namita, and Kaushik Chandra Deva Sarma. "Channel Potential Modelling of Surrounded Channel Junction Less Field Effect Transistor." Journal of Nanoelectronics and Optoelectronics 17, no. 2 (February 1, 2022): 211–17. http://dx.doi.org/10.1166/jno.2022.3186.
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An analytical model for potential in channel region is obtained for a Surrounded channel junction-less field effect transistor. Two dimensional Poisson’s equation has been solved to obtain the mathematical potential modelling. The dependence of channel potential on gate voltage, gate oxide thickness, type of gate dielectric, doping concentration, channel length is shown. The model is fully analytical in nature and suitable for compact modelling. The potential model developed is compared with results obtained from TCAD numerical simulation results.
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Novak, Roman. "Viability of Numerical Full-Wave Techniques in Telecommunication Channel Modelling." Journal of communications software and systems 16, no. 4 (October 8, 2020): 269–78. http://dx.doi.org/10.24138/jcomss.v16i4.1041.
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In telecommunication channel modelling the wavelength is small compared to the physical features of interest, therefore deterministic ray tracing techniques provide solutions that are more efficient, faster and still within time constraints than current numerical full-wave techniques. Solving fundamental Maxwell's equations is at the core of computational electrodynamics and best suited for modelling electrical field interactions with physical objects where characteristic dimensions of a computing domain is on the order of a few wavelengths in size. However, extreme communication speeds, wireless access points closer to the user and smaller pico and femto cells will require increased accuracy in predicting and planning wireless signals, testing the accuracy limits of the ray tracing methods. The increased computing capabilities and the demand for better characterization of communication channels that span smaller geographical areas make numerical full-wave techniques attractive alternative even for larger problems. The paper surveys ways of overcoming excessive time requirements of numerical full-wave techniques while providing acceptable channel modelling accuracy for the smallest radio cells and possibly wider. We identify several research paths that could lead to improved channel modelling, including numerical algorithm adaptations for large-scale problems, alternative finite-difference approaches, such as meshless methods, and dedicated parallel hardware, possibly as a realization of a dataflow machine.
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Pätzold, Matthias, and Carlos A. Gutierrez. "Modelling and Analysis of Nonstationary Vehicle-to-Infrastructure Channels with Time-Variant Angles of Arrival." Wireless Communications and Mobile Computing 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/6396173.
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In mobile radio channel modelling, it is generally assumed that the angles of arrival (AOAs) are independent of time. This assumption does not in general agree with real-world channels in which the AOAs vary with the position of a moving receiver. In this paper, we first present a mathematical model for the time-variant AOAs. This model serves as the basis for the development of two nonstationary multipath fading channels models for vehicle-to-infrastructure communications. The statistical properties of both channel models are analysed with emphasis on the time-dependent autocorrelation function (ACF), time-dependent mean Doppler shift, time-dependent Doppler spread, and the Wigner-Ville spectrum. It is shown that these characteristic quantities are greatly influenced by time-variant AOAs. The presented analytical framework provides a new view on the channel characteristics that goes well beyond ultra-short observation intervals over which the channel can be considered as wide-sense stationary.
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Yang-jun, WANG, and YIN Tai-ju. "Numerical forward Modelling of River-dominated Deltas." Applied Science and Innovative Research 4, no. 1 (January 11, 2020): p16. http://dx.doi.org/10.22158/asir.v4n1p16.
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A delta is a type of sedimentary system that is closely related to oil and gas. Shallow-lake delta deposits in the Mesozoic-Cenozoic strata of China are of particular interest. This delta has significant oil and gas reserves that are developed widely. Based on a numerical simulation of the sand body of the shallow-lake delta, this study analyzes the influence of various sediment conditions on the sand-body development. The formation and distribution rules of the sand body are concluded and verified, and the results can effectively guide the exploration and development of oil and gas resources. Unlike traditional flume experiments, this study adopts sediment numerical simulation technology. This approach is borrowed from the advanced achievements of computational fluid dynamics, and Delft3D is used to establish a three-dimensional numerical model of the delta. The calculation field was 20.5 km in length by 10 km in width. With the Mor-Factor set to 60, the simulation time was 45 days. The formation and the avulsion of the mouth bar, as well as the extension, migration and bifurcation of distributary channels, have been observed and studied through analysis of the simulation results. The vertical cross-section shows that the distributary channel was filled multiple times. According to distributary channel evolution characteristics combined with quantitative methods, the terminal distributary channels can be extremely developed under ideal conditions. Due to the cross-cutting and reform effort of distributary channels, sediments were spread widely and continuously. The results show that the numerical model works well in explaining the process of evolution in fluvial-dominated delta distributary channels. This study not only enables us to quantitatively understand the dynamic processes of terminal distributary channels in fluvial-dominated delta systems, but also provides a reference model for numerical simulation of hydrodynamics in sedimentology study.
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Akinniyi, Akinade Olutayo, Awofolaju Tolulope Tola, and Oladepo Olatunde. "Modelling of Land Mobile Satellite Channel to Counter Channel Outage." International Journal of Distributed and Parallel systems 8, no. 2 (March 31, 2017): 1–21. http://dx.doi.org/10.5121/ijdps.2017.8201.
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Balroo, Shuaib Ahmed. "Role of Omni Channel Attributes and Perceived Behavioral Control in Omni Channel Selection." Journal of Economics, Management and Trade 29, no. 11 (November 17, 2023): 90–103. http://dx.doi.org/10.9734/jemt/2023/v29i111165.
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The retailing industry worldwide is transitioning from multi-channel retailing to omni channel retailing. In contrast to multi-channel retailing which provides offerings through different and separate channels, all channels are essentially well integrated in omni channel retailing. In the middle eastern region, the transition from multi-channel to omni channel retailing is rapidly taking place in Saudi Arabia. However, managing channels synergistically for providing seamless customer experience is proving out to be challenging task for omni channel retailers. What omni channel attributes are valued necessary by consumers in making them seamlessly choose omni channels for shopping are not explicit in the literature especially in Saudi Arabian context. In order to better integrate and coordinate channels it is very important for omni channel retailers to first understand the behavior of omni channel shoppers. The omni channel retailers need to know what omni channel attributes influence consumer’s perception of ease and ability in selecting omni channels for shopping. This study examines how omni channel attributes namely omni channel transparency, omni channel convenience and omni channel uniformity help in influencing consumer’s perception in selecting omni channels. The study employed snowball sampling method for collecting the sample of omni shoppers from different regions of Saudi Arabia. The study sample comprised of 551 respondents who actively shopped through various omni channel retailers of Saudi Arabia. All hypothesized relationships of the study were tested simultaneously using structural equation modelling technique. The study reported that omni channel transparency, omni channel convenience and omni channel uniformity positively influence consumer’s perception in selecting omni channels in Saudi Arabia. This study tries to combine consumer and omni channel retailer perspectives for the better understanding of shopping behaviors across omni channels. With the better understanding of consumer shopping behaviors, omni channel retailers would be thus able to better integrate their channels and coordinate their supply chains to the best satisfaction of their consumers.
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Wang, Jun, Xianxue Cheng, and Shuhua Zhang. "Low Carbon Distribution Channel Coordination with a Capital-Constrained Retailer." Discrete Dynamics in Nature and Society 2018 (August 1, 2018): 1–13. http://dx.doi.org/10.1155/2018/9579348.
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Capital constraints exist in many supply chains. We examine a low carbon distribution channel that consists of a manufacturer and a retailer, in which the retailer is constrained by capital. The retailer can be financed by bank credit from a competitive bank market. A Stackelberg model is developed to analyze the integrated decision-making process of ordering, financing, and emission reduction. By comparing the decentralized and centralized channels, we obtain that the manufacturer’s green technology investment should be linearly proportional to the retailer’s order quantity in both channels. Thus, a large order quantity leads to increased efforts to reduce emissions. Results further show that the centralized channel in some cases has fewer emissions and can generate more profits for the whole supply chain compared with the decentralized channel. We therefore propose a revenue sharing contract with a function form to coordinate the distribution channel. When the government allocates appropriate quotas to the supply chain, high carbon price can benefit the environment and supply chain efficiency.
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MILNE, J. A., and D. A. SEAR. "Modelling river channel topography using GIS." International Journal of Geographical Information Science 11, no. 5 (July 1997): 499–519. http://dx.doi.org/10.1080/136588197242275.
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Damgaard, Jesper, Nick Dodd, Lisa Hall, and Tim Chesher. "Morphodynamic modelling of rip channel growth." Coastal Engineering 45, no. 3-4 (May 2002): 199–221. http://dx.doi.org/10.1016/s0378-3839(02)00034-0.
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Lewis, Rebecca, and Richard Barrett-Jolley. "Modelling Ion Channel Behaviour in Chondrocytes." Biophysical Journal 100, no. 3 (February 2011): 91a. http://dx.doi.org/10.1016/j.bpj.2010.12.705.
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Burger, Martin. "Inverse problems in ion channel modelling." Inverse Problems 27, no. 8 (July 4, 2011): 083001. http://dx.doi.org/10.1088/0266-5611/27/8/083001.
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Szosland, Janusz. "MODELLING THE STRUCTURAL BARRIER ABILITY OF WOVEN FABRICS." AUTEX Research Journal 3, no. 3 (September 1, 2003): 102–10. http://dx.doi.org/10.1515/aut-2003-030302.
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Abstract Woven fabrics with their full, systematically arranged and non-stochastic structure, are the subject of increasing interest as barriers to fluids, radiation, micro-particles, and micro-organisms. The structure of woven fabrics, which is characterised by inter-thread channels of predetermined shape and location, is especially important. Some procedures for designing channel shape and methods for sealing barrier woven fabrics are presented.
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De FABRITIIS, G., J. VILLÀ-FREIXA, and P. V. COVENEY. "MULTISCALE MODELLING OF PERMEATION THROUGH MEMBRANE CHANNELS USING PREGENERATED MOLECULAR DYNAMICS TRAJECTORIES." International Journal of Modern Physics C 18, no. 04 (April 2007): 511–19. http://dx.doi.org/10.1142/s0129183107010747.
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Permeation of small molecules across membrane channels can be measured by a multiscale computational protocol based on Brownian dynamics and the potential of mean force formalism. In this article we look at ways to compute the potential of mean force by reusing pre-existing molecular dynamics trajectories via a protocol centered on instantaneous forward/reverse transformations. We apply the method to the energetics of water across the narrow channel formed by Gramicidin A and reproduce several features of the energy barrier across the channel albeit at a coarse level of detail due to limits imposed by the exponential averages intrinsic to the method and the small size of the channel. The implications for ions and less dense systems are briefly discussed.
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Lotsari, Eliisa, Varyl Thorndycraft, and Petteri Alho. "Prospects and challenges of simulating river channel response to future climate change." Progress in Physical Geography: Earth and Environment 39, no. 4 (May 5, 2015): 483–513. http://dx.doi.org/10.1177/0309133315578944.
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Due to the predicted impacts of future climate on hydrology, morphological changes to river channels are expected. Quantifying the magnitudes and rates of future channel change is important for sustainable river channel management. To date, reviews of simulation approaches for investigating river channels and the modelling of environmental change impacts on channel form and process have focused on contemporary process or palaeo perspectives. Hence, herein we review numerical modelling approaches available for reach-scale simulation of future river channels and the predicted in-channel hydro- and morphodynamic changes modelled. We found that despite their widespread availability, hydrodynamic, morphodynamic and cellular models have yet to be used routinely in future in-channel simulations, with cellular models in particular under-represented. Our review shows that predictions of within-channel changes vary greatly between hydro-climatic regions and under contrasting climate change scenarios, mainly due to varying input discharge scenarios; however, increased sediment transport and flood risk are usually predicted. Key challenges in simulating future channel change include representations of external forcing conditions, adequate temporal and spatial scales, transport equations, changing channel materials and lateral erosion; calibration and validation; simulation chains with multiple models; and identification of feedback systems and non-linearity. Nevertheless, despite these challenges, models with increasing complexity have recently been developed and so there is increasing potential in their application. One-dimensional hydro- and morphodynamic simulations, and cellular models, can be modified to reflect the requirements of future representations, such as grain size properties, whilst there is also now an increasing capability to include a greater quantity of external forcing conditions. Some studies, however, have demonstrated the need to develop two-dimensional models for application in centennial-scale studies. We recommend that a wider range of scenarios and the combined effects of multiple external forcing factors should be included, whilst studies are also needed from more hydrologically diverse reaches.
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Yan, Wei, Youwei Li, Ying Wu, and Mark Palmer. "A Rising E-Channel Tide Lifts All Boats? The Impact of Manufacturer Multichannel Encroachment on Traditional Selling and Leasing." Discrete Dynamics in Nature and Society 2016 (2016): 1–18. http://dx.doi.org/10.1155/2016/2898021.
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Organizing and managing channels of distribution is an important marketing task. Due to the emergence of electronic commerce on the Internet, e-channel distribution systems have been adopted by many manufacturers. However, academic and anecdotal evidence both point to the pressures arising from this new e-channel manufacturing environment. Question marks therefore remain on how the addition of this e-channel affects the traditional marketing strategies of leasing and selling. We set up several two-period dual-channel models in which a manufacturer sells a durable product through both a manufacturer-owned e-channel and an independent reseller (leaser) who adopts selling (leasing) to consumers. Our main results indicate that, direct selling cost aside, product durability plays an important role in shaping the strategies of all members. With either marketing strategy, the additional expansion of an e-channel territory may secure Pareto gains, in which all members benefit.
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Pudasaini, S. P., Y. Wang, and K. Hutter. "Modelling debris flows down general channels." Natural Hazards and Earth System Sciences 5, no. 6 (October 26, 2005): 799–819. http://dx.doi.org/10.5194/nhess-5-799-2005.
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Abstract. This paper is an extension of the single-phase cohesionless dry granular avalanche model over curved and twisted channels proposed by Pudasaini and Hutter (2003). It is a generalisation of the Savage and Hutter (1989, 1991) equations based on simple channel topography to a two-phase fluid-solid mixture of debris material. Important terms emerging from the correct treatment of the kinematic and dynamic boundary condition, and the variable basal topography are systematically taken into account. For vanishing fluid contribution and torsion-free channel topography our new model equations exactly degenerate to the previous Savage-Hutter model equations while such a degeneration was not possible by the Iverson and Denlinger (2001) model, which, in fact, also aimed to extend the Savage and Hutter model. The model equations of this paper have been rigorously derived; they include the effects of the curvature and torsion of the topography, generally for arbitrarily curved and twisted channels of variable channel width. The equations are put into a standard conservative form of partial differential equations. From these one can easily infer the importance and influence of the pore-fluid-pressure distribution in debris flow dynamics. The solid-phase is modelled by applying a Coulomb dry friction law whereas the fluid phase is assumed to be an incompressible Newtonian fluid. Input parameters of the equations are the internal and bed friction angles of the solid particles, the viscosity and volume fraction of the fluid, the total mixture density and the pore pressure distribution of the fluid at the bed. Given the bed topography and initial geometry and the initial velocity profile of the debris mixture, the model equations are able to describe the dynamics of the depth profile and bed parallel depth-averaged velocity distribution from the initial position to the final deposit. A shock capturing, total variation diminishing numerical scheme is implemented to solve the highly non-linear equations. Simulation results present the combined effects of curvature, torsion and pore pressure on the dynamics of the flow over a general basal topography. These simulation results reveal new physical insight of debris flows over such non-trivial topography. Model equations are applied to laboratory avalanche and debris-flow-flume tests. Very good agreement between the theory and experiments is established.
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Thomas, Ian W., John D. Collinson, and Colin M. Jones. "Depositional Modelling of UK North Sea Alba Field Reservoir." Energy Exploration & Exploitation 10, no. 4-5 (September 1992): 300–320. http://dx.doi.org/10.1177/014459879201000408.
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The Alba Field is contained within block 16/26 of the Central North Sea of the United Kingdom. This oil field was discovered in 1984 by Chevron UK Ltd with the 16/26–5 well and has been appraised by 16 wells and sidetracks. The field is currently being developed and is scheduled to achieve first production around the end of 1993. A 3-D seismic survey, acquired in 1989, has greatly enhanced delineation of the field. It is a NW-SE trending linear feature approximately 5.25 miles (8.5 kms) in length with adjacent satellite structures. The reservoir sands comprise the Nauchlan Member of the Alba Formation (Horda Group) and are primarily of Middle Eocene age. Gross sand thicknesses in excess of 400 ft (120 m) are present within the field area with porosities ranging up to 38% and permeabilities of the order of 2800 mD. The sands were deposited as a series of submarine channel fills whose mutual relationships present problems of detailed interpretation. Channel sandbodies appear to be discontinuous along their length for a variety of reasons including erosive relief on the base of the channel, and partial filling of channels otherwise filled by mud.
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Lucas, H., M. H. Aslami, Farell, and Ferryanto. "Modelling of flow characteristics in the access channel of Bali tourism port using DualSPHysics." IOP Conference Series: Earth and Environmental Science 1324, no. 1 (April 1, 2024): 012047. http://dx.doi.org/10.1088/1755-1315/1324/1/012047.
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Abstract The access channel is a structure formed as a basin on the seabed. Based on previous studies, excessive sediment accumulation in shipping lanes or access channels carried by ocean floor currents is one of the factors that cause damage to the hull under the ship. Therefore, this study aims to investigate the characteristics of seabed currents that cross the access channel. This research was carried out by modelling the numerical test of the access channel model using the Smoothed Particle Hydrodynamics (SPH) method with DualSPHysics software. The results of this study show the movement and characteristics of seabed currents that occur in the access channel at the Bali Sanur Harbor. This study obtained the average speed of seabed currents, with variations in the speed of ocean currents and forecasts regarding sediment dredging maintenance on cruise lines.
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Miramirkhani, Farshad, and Murat Uysal. "Channel modelling for indoor visible light communications." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2169 (March 2, 2020): 20190187. http://dx.doi.org/10.1098/rsta.2019.0187.
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Visible light communication (VLC) allows the dual use of light-emitting diodes (LEDs) for wireless communication purposes in addition to their primary purpose of illumination. As in any other communication system, realistic channel modelling is a key for VLC system design, analysis and testing. In this paper, we present a comprehensive survey of indoor VLC channel models. In order to set the background, we start with an overview of infrared (IR) channel modelling, which has received much attention in the past, and highlight the differences between visible and IR optical bands. In the light of these, we present a comparative discussion of existing VLC channel modelling studies and point out the relevant advantages and disadvantages. Then, we provide a detailed description of a site-specific channel modelling approach based on non-sequential ray tracing that precisely captures the optical propagation characteristics of a given indoor environment. We further present channel models for representative deployment scenarios developed through this approach that were adopted by the Institute of Electrical and Electronics Engineering (IEEE) as reference channel models. Finally, we consider mobile VLC scenarios and investigate the effect of receiver location and rotation for a mobile indoor user. This article is part of the theme issue ‘Optical wireless communication’.
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Zhao, Yan-Fei, Yong Wang, and Guo-Qiang Shi. "The Impact of Consumers’ Peer-Induced Fairness Concerns on Mixed Retail and E-Tail Channels." Discrete Dynamics in Nature and Society 2020 (November 16, 2020): 1–15. http://dx.doi.org/10.1155/2020/9023470.
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With the rapid development of e-commerce, online retailing has become an important part of the market. In order to improve market competitiveness and increase market share, more and more retailers have opened both regular offline channel and online e-tail channel to sell products. Then how to price becomes an urgent problem for upstream manufacturers and dual-channel retailers when there is price competition between regular channel and e-tail channel, especially when consumers have peer-induced fairness concerns. However, linking consumers’ behavioral factors such as fairness concerns to pricing decisions of mixed retail and e-tail channels draws little attention in the literature on supply chain management. This paper incorporates “consumers’ peer-induced fairness concerns” (CPFC) into pricing decisions in a dyadic supply chain, where dual-channel retailer obtains products from manufacturers and then sells products to consumers through both regular channel and e-tail channel. We use game-theoretic models to analyze the equilibrium pricing strategies under the setting with “symmetry consumers’ peer-induced fairness concerns” (SCPFC) and with “asymmetry consumers’ peer-induced fairness concerns” (ACPFC), respectively. Detailed comparisons and numerical analysis are further conducted to examine the impacts of different types of CPFC on equilibrium pricing strategies and profits.
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Krishnaiah, Arkanti. "Finite Element Modelling of Copper by Equal Channel Angular Extrusion." Advanced Materials Research 941-944 (June 2014): 2313–16. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.2313.
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Equal channel angular extrusion (ECAE) is a severe plastic deformation (SPD) method for obtaining bulk nanostructured materials. The ECAE die consists of two equal channels that intersect at an angle, usually between 90o and 135o. . In the present study, the plastic deformation behavior of copper during the ECAE process with 120o die was investigated. To analyze the deformation behavior and the related strain distributions in the specimen, the commercial FE code ABAQUS has been used. The properties of the materials are strongly dependent on the shear plastic deformation behavior during equal channel angular extrusion (ECAE), which is controlled mainly by die geometry, material properties, and the friction between billet and the die. The ECAE process for these conditions was explained using the two different friction conditions of 0.15 and 0.08 to all sliding surfaces. The effective strain by the theoretical equation is in good agreement with the FEM results.
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Qian, Yu. "Signal Processing and Channel Modelling for 5G Millimeter-Wave Communication Environment." Volume 31, Issue 3 31, no. 3 (April 4, 2024): 137–50. http://dx.doi.org/10.20532/cit.2023.1005746.
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Compared to frequency bands below 6 GHz, 5G millimeter waves offer several advantages, including a large bandwidth, minimal null delay, and flexible null port configuration. To comprehend the channel characteristics of 5G millimeter-wave technology, conducting channel measurements on it is essential. Hence, to ensure precise 5G millimeter-wave channel measurements and facilitate channel modelling, this study recommends utilizing a phased array antenna-based method for the channel measurement. The experimental outcomes demonstrated that the shadow fading term of the actual measurement data follows a normal distribution in both line-of-sight and non-line-of-sight scenarios. Additionally, the K-S test confirms that all Boolean variables are equal to 1 and all numerical variables are greater than α. The line-of-sight scenario produces a logarithmic mean delay extension of –7.4 and a standard deviation of 0.12, based on actual measured data. Meanwhile, the 3GPP shows a logarithmic mean of –7.4 and a standard deviation of 0.15. In the non-line-of-sight scenario, the logarithmic mean delay extension is –7.3 with a standard deviation of 0.17, while the 3GPP produces a logarithmic mean of –7.4 and a standard deviation of 0.19. The data presented closely adheres to the 3GPP model. It is evident that the channel measurement method, proposed within the study, effectively measures the parameters within the delay domain. Concerning the prolonged pitch angle and azimuth angle ranges, they measure 14°–31° and 14°–29° in the line-of-sight situation, and 21°–33° and 19°–37° in the corresponding non-line-of-sight situation. Additionally, the logarithmic mean and standard deviation for both the pitch angle and azimuth angle in the line-of-sight scenario are 1.32 and 0.09, respectively. The logarithmic mean and standard deviation of the azimuth angle of arrival are 1.35 and 0.08, respectively. The above results show that the method proposed in the study enables the measurement of 5G millimeter-wave channels and is important for millimeter-wave channel modelling.
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Vidal, Catarina, Virgínia Infante, Yoann Lage, and Pedro Vilaça. "Modelling Microstructural Effects on the Mechanical Behaviour of a Friction Stirred Channel Aluminium Alloy." Key Engineering Materials 577-578 (September 2013): 37–40. http://dx.doi.org/10.4028/www.scientific.net/kem.577-578.37.
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Friction stir channelling (FSC) is a relatively new solid-state manufacturing technology able to produce conformal channels in a monolithic plate in a single step. During the FSC process the metal workpiece material is softened by the heat energy generated from dissipation during: plastic deformation, internal material flow and frictional work between the tool and the metal workpiece. The mechanical performance of a friction stirred channel aluminium alloy is affected by microstructure surrounding the channel. A new methodology that simulates a realistic 2D microstructure from experimental metallographic characterization and tensile tests was developed using the commercial software ABAQUS to study the mechanical behaviour of the friction stirred channel 5083-H111 aluminium alloy. Fourpoint bending tests were simulated and compared with experimental results. The RambergOsgood model was also adopted in the finite element analysis. It is seen from this investigation that microstructure can significantly affect the bending strength of friction stirred channel plates.
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Chen, Ming-fei, Yan-qiu Liu, Yang Song, and Qi Sun. "A Contract Coordination Model of Dual-Channel Delivery between UAVs and Couriers Considering the Uncertainty of Delivery for Last Mile." Discrete Dynamics in Nature and Society 2019 (December 8, 2019): 1–11. http://dx.doi.org/10.1155/2019/6214359.
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For the traditional last-kilometer delivery, commodities are sent from the distribution center to the distribution transfer station, which are then delivered by the couriers from the distribution transfer station to the consumers. This single distribution channel cannot prioritize services for consumers closer to the distribution center, resulting in a waste of distribution resources. To deal with the last-kilometer delivery problem, this paper attempts to build a dual-channel distribution system consisting of UAVs and couriers. And the impact of the market allocation proportion on the expected profit of the last mile service through the two different distribution channels is discussed and analyzed. It is proved that the improved revenue sharing contract can realize the coordination of the dual-channel distribution between UAVs and the couriers. The numerical examples verify the effectiveness of the model and contract coordination. According to the research, first, with the increase in the uncertainties of the delivery quantity, the profit of the UAV channel shows a downward trend, while the profit of the courier channel remains basically the same. This is because the labor cost of the courier channel is relatively stable. Second, with the increase in the market allocation proportion of the last-kilometer delivery, the optimal delivery quantity of the UAV channel and the optimal order quantity of the courier channel are both increasing, while the overall profit of the last-kilometer is first rising and then decreasing. Third, the expected profit of the UAV channel and the courier channel can achieve Pareto improvement through the improved revenue sharing contract.
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Kucera, Pavel. "On Analogue TMR System." International Journal of Organizational and Collective Intelligence 3, no. 4 (October 2012): 1–18. http://dx.doi.org/10.4018/ijoci.2012100101.
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This chapter presents a reliability model of the TMR (Triple Modular Redundancy) system based on analogue measurement channels. While reliability modelling of the standard TMR system (based on digital channels) has been well described in many previous publications, an applicable reliability solution for analogue measurement channels is still missing. First, the structure of analogue measurement channel is described in this chapter. Then, the reliability model of the wiring system is introduced. Next, the standard TMR model is presented and its reliability model is mentioned. An analogue TMR measurement channel system is introduced and its reliability model based on Markov processes is presented. Then the reliability model of the communication channel is described. Finally, the reliability of this model is analytically calculated and the solution is applied to an example.
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Vaz, Nuno, João Miguel Dias, and Paulo Chambel Leitão. "Three-dimensional modelling of a tidal channel: The Espinheiro Channel (Portugal)." Continental Shelf Research 29, no. 1 (January 2009): 29–41. http://dx.doi.org/10.1016/j.csr.2007.12.005.
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Durugbo, Christopher. "Bunch: a channel-oriented business network modelling approach." Business Process Management Journal 20, no. 3 (May 27, 2014): 455–79. http://dx.doi.org/10.1108/bpmj-02-2013-0017.
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Purpose – The purpose of this paper is to evaluate the benefits of using the business network channel (Bunch) approach for modelling business networks and studying the business network evolution. Business network models put the structures of process models into context by visualising roles and communication channels for social interactions. Design/methodology/approach – The research applies a case study-based approach involving the creation of business network visualisations to capture snapshots of an industrial firm's business network over a three-year period. A questionnaire-based study was also conducted with 18 key informants to evaluate the Bunch approach against existing business network modelling techniques. Findings – This study shows that when business networks – as opposed to business processes – are diagrammatically modelled, patterns of relations between individuals can also be visualised and factored into how information systems are (re)designed and deployed. The study also finds that as business networks evolve, the ability to offer complementary channels of communication and coordinate business/technological information is vital to how upturns in process times improves overall business effectiveness and efficiency. Originality/value – The major contribution of this paper is an exposition on how the Bunch approach could serve as a pedagogical tool for gaining clarity on their roles and links within the business and as an analytical tool for studying the evolution of business networks in relation to roles, links, information technologies, business strategies and business network anomalies.
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Nowogoński, Ireneusz. "Emporal and Spatial Variability of Rainfall in Modelling of Stormwater Outflows." Civil and Environmental Engineering Reports 29, no. 4 (December 1, 2019): 267–78. http://dx.doi.org/10.2478/ceer-2019-0060.
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Abstract The article presents issues related to modeling of the rainfall-runoff phenomenon. As factors influencing the simulation results, the velocity and direction of precipitation relative to the drainage basin were indicated. The possibility of underestimating the cross-sections of rainwater channels as a result of overlapping rain wave directions and the dominant flow direction in the rainwater channel network was pointed out. The research results to date indicate a reduction in the symptoms of this phenomenon as the complexity of the channel network increases. The final verification was based on the actual catchment. Calculations were made using the Epa SWMM 5.1.013 software. The results are presented in a graphic form to illustrate the variability of stormwater outflow.
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Kharchenko, Volodymir, Bo Wang, Andrii Grekhov, and Anna Leschenko. "MODELLING THE SATELLITE COMMUNICATION LINKS WITH ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXING." TRANSPORT 31, no. 1 (January 28, 2015): 22–28. http://dx.doi.org/10.3846/16484142.2014.1003599.
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Global technologies of data transmission in real time are developing constantly. Therefore, modelling of messages transmission through satellite constellations is an actual problem. In this paper the original model of a communication channel ‘Vehicle-to-Satellite-to-Ground Station’ based on principles of the IEEE 802.11a standard is designed using MatLab Sіmulіnk software. The model allows simulating data transmission with data rate from 6 to 54 Mbit/s using adaptive modulation. Two types of channels were analysed for uplink/downlink modulation – a free space path losses with phase/frequency offset and Additive White Gaussian Noise (AWGN) link. On the base of this model, channel integrity was investigated and dependences of a Signal-Noise Ratio (SNR) on free space path losses, antennas diameters, number of OFDM symbols and satellite transponder noise temperature were received.
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Konz, M., M. Chiari, S. Rimkus, J. M. Turowski, P. Molnar, D. Rickenmann, and P. Burlando. "Sediment transport modelling in a distributed physically based hydrological catchment model." Hydrology and Earth System Sciences Discussions 7, no. 5 (October 4, 2010): 7591–631. http://dx.doi.org/10.5194/hessd-7-7591-2010.
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Abstract. Sediment transport and erosion processes in channels are important components of water induced natural hazards in alpine environments. A distributed hydrological model, TOPKAPI, has been developed to support continuous simulations of river bed erosion and deposition processes. The hydrological model simulates all relevant components of the water cycle and non-linear reservoir methods are applied for water fluxes in the soil, on the surface and in the channel. The sediment transport simulations are performed on a sub-grid level, which allows for a better discretization of the channel geometry, whereas water fluxes are calculated on the grid level in order to be CPU efficient. Flow resistance due to macro roughness is considered in the simulation of sediment transport processes. Several transport equations as well as the effects of armour layers on the transport threshold discharge are considered. The advantage of this approach is the integrated simulation of the entire water balance combined with hillslope-channel coupled erosion and transport simulation. The comparison with the modelling tool SETRAC and with LiDAR based reconstructed sediment transport rates demonstrates the reliability of the modelling concept. The modelling method is very fast and of comparable accuracy to the more specialised sediment transport model SETRAC.