Channel selection of a monopoly manufacturer in a two-tier vertically differentiated market

2014 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Bo Tai Tzeng ◽  
Wei Wei Lee
Keyword(s):  
Channel Selection ◽  
Selection Of

scholarly journals Evolutionary Multitasking-Based Multiobjective Optimization Algorithm for Channel Selection in Hybrid Brain Computer Interfacing Systems

2021 ◽  
Vol 15 ◽  
Author(s):  
Tianyu Liu ◽  
Zhixiong Xu ◽  
Lei Cao ◽  
Guowei Tan
Keyword(s):  
Multiobjective Optimization ◽  
Real Life ◽  
Channel Selection ◽  
Research Field ◽  
Neural Engineering ◽  
Computer Interfaces ◽  
Classification Tasks ◽  
Optimization Methodology ◽  
Brain Computer Interfacing ◽  
Selection Of

Hybrid-modality brain-computer Interfaces (BCIs), which combine motor imagery (MI) bio-signals and steady-state visual evoked potentials (SSVEPs), has attracted wide attention in the research field of neural engineering. The number of channels should be as small as possible for real-life applications. However, most of recent works about channel selection only focus on either the performance of classification task or the effectiveness of device control. Few works conduct channel selection for MI and SSVEP classification tasks simultaneously. In this paper, a multitasking-based multiobjective evolutionary algorithm (EMMOA) was proposed to select appropriate channels for these two classification tasks at the same time. Moreover, a two-stage framework was introduced to balance the number of selected channels and the classification accuracy in the proposed algorithm. The experimental results verified the feasibility of multiobjective optimization methodology for channel selection of hybrid BCI tasks.

scholarly journals Ozone-sensitive channel selection over IASI full spectrum with correlated observation errors for NWP

2019 ◽  
Author(s):  
Olivier Coopmann ◽  
Vincent Guidard ◽  
Béatrice Josse ◽  
Virginie Marécal ◽  
Nadia Fourrié
Keyword(s):  
Covariance Matrix ◽  
Weather Prediction ◽  
Channel Selection ◽  
Spectral Interval ◽  
Observation Error ◽  
Full Spectrum ◽  
Error Covariance Matrix ◽  
Error Covariance ◽  
One Year ◽  
Selection Of

Abstract. The Infrared Atmospheric Sounding Interferometer (IASI) onboard the Metop satellites provides 8461 channels in the infrared spectrum, covering the spectral interval 645–2760 cm−1 at a resolution of 0.5 cm−1. The high volume of data observation resulting from IASI presents many challenges. In current Numerical Weather Prediction (NWP) models, assimilating all channels is not feasible, due to data transmission, data storage and significant computational costs. One of the methods for reducing the data volume is the channel selection. Many NWP centres use a subset of 314 IASI channels including 15 ozone-sensitive channels. However, this channel selection has been carried out assuming uncorrelated observation errors. In addition, these ozone-sensitive channels have been selected only for ozone information. The objective of this study is to carry out a new selection of IASI ozone-sensitive channels from the full spectrum over a spectral range of 1000–1070 cm−1, in a direct radiance assimilation framework. This selection is done with a full observation error covariance matrix to take into account cross-channel error correlations. A sensitivity method based on the channel spectral sensitivity to variables and a statistical approach based on the Degrees of Freedom for Signal (DFS) have been chosen. To be representative of atmospheric variability, 345 profiles from around the world over a one-year period were selected. The new selection, is evaluated in a One-Dimensional Variational (1D-Var) analyses framework. This selection highlights a new set of 15 IASI ozone-sensitive channels. The results are very encouraging since by adding these 15 channels to 122 operational channels, temperature and humidity analyses are improved by 13.8 % and 20.9 % respectively. Obviously, these 15 channels significantly improve ozone analyses. In addition to considering inter-channel observation error correlations, the channel selection method uses a robust background error covariance matrix that takes into account temperature, humidity and ozone errors using a lagged forecast method over a one-year period. The new selection of IASI ozone-sensitive channels will be soon used in the global 4D-Var ARPEGE (Action de Recherche Petite Echelle Grande Echelle) data assimilation system.

Publisher’s distribution channel selection of print books in a book supply chain with print and e-books

2021 ◽  
Vol 12 (3) ◽  
pp. 358-385
Author(s):  
Yuwen Zeng ◽  
Wenhua Hou
Keyword(s):  
Stackelberg Game ◽  
Distribution Channel ◽  
Channel Selection ◽  
Third Party ◽  
Digital Products ◽  
Content Type ◽  
Print Books ◽  
Structured Analysis ◽  
Channel Mode ◽  
Selection Of

Purpose This paper aims to exam the publisher’s online distribution strategies of print books between a reselling and a marketplace channel with the coexistence of e-book. This study extends the study of channel selection to the content products industry. Design/methodology/approach By constructing a publisher-leader Stackelberg game model, the authors investigate the publisher’s distribution strategies. The retailer holds a digital channel for e-book and reselling and marketplace channels for print books. The authors examine three-channel modes for the print book distribution: a pure reselling channel, a marketplace channel and a hybrid channel. Findings The results reveal that a hybrid channel always dominates a pure marketplace channel from the publisher’s perspective. Then, only when the print book’s margin cost and the marketplace’s slotting fee are not very high, the publisher prefers the hybrid to a pure reselling channel. The authors also found a Pareto zone where the hybrid channel mode improves publisher’s and retailer’s profits. Furthermore, the publisher is less likely to choose the hybrid channel as the acceptance of e-book increases. The authors also examine the situation where a publisher-authorized third-party distributor runs the marketplace channel and found the results still hold. Originality/value This paper fills a theoretical and practical gap for a structured analysis of the content providers’ online distribution channel selection of the physical products and digital products. Different from previous related studies, this study focuses on analyzing physical products’ channel strategies and finds physical products’ cost plays a crucial role in the content provider’s channel decision.

scholarly journals Update of Infrared Atmospheric Sounding Interferometer (IASI) channel selection with correlated observation errors for numerical weather prediction (NWP)

2020 ◽  
Vol 13 (5) ◽  
pp. 2659-2680
Author(s):  
Olivier Coopmann ◽  
Vincent Guidard ◽  
Nadia Fourrié ◽  
Béatrice Josse ◽  
Virginie Marécal
Keyword(s):  
Numerical Weather Prediction ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Channel Selection ◽  
Observation Error ◽  
Numerical Weather ◽  
Atmospheric Sounding ◽  
Analysis Error ◽  
Concept Of Information ◽  
Selection Of

Abstract. The Infrared Atmospheric Sounding Interferometer (IASI) is an essential instrument for numerical weather prediction (NWP). It measures radiances at the top of the atmosphere using 8461 channels. The huge amount of observations provided by IASI has led the community to develop techniques to reduce observations while conserving as much information as possible. Thus, a selection of the 300 most informative channels was made for NWP based on the concept of information theory. One of the main limitations of this method was to neglect the covariances between the observation errors of the different channels. However, many centres have shown a significant benefit for weather forecasting to use them. Currently, the observation-error covariances are only estimated on the current IASI channel selection, but no studies to make a new selection of IASI channels taking into account the observation-error covariances have yet been carried out. The objective of this paper was therefore to perform a new selection of IASI channels by taking into account the observation-error covariances. The results show that with an equivalent number of channels, accounting for the observation-error covariances, a new selection of IASI channels can reduce the analysis error on average in temperature by 3 %, humidity by 1.8 % and ozone by 0.9 % compared to the current selection. Finally, we go one step further by proposing a robust new selection of 400 IASI channels to further reduce the analysis error for NWP.

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