A Consumer Logistics Framework for Understanding Preferences for High-Speed Rail Transportation, MTI Report 05-04

The prospect for high-speed rail (HSR) service for the San Francisco-Los Angeles corridor and beyond first arose eight years ago. The plan remains to connect California’s major cities in the next 15 years at a total cost of $25 billion. The purpose of this study is to reach a fuller understanding of consumers’ perceptions of such a service. Consumer logistics theory is used in the study as a framework to begin to provide this understanding of consumer perceptions and to inform future efforts to develop and market HSR service. This study uses the consumer logistics framework to help understand how various demographic groups, various groups defined by public transportation usage frequency, and various groups defined by HSR usage intention level perceive various logistical aspects of HSR service. The consumer logistics framework is also be used to develop a macro model that examines the relationship between performance of consumer logistics functions, perceptions of HSR travel value (consisting of travel efficiency and effectiveness), and HSR travel intention for intercity business commuters. The results show the manner and the extent to which the logistics of HSR are likely to lead to customer intentions to use it for inter-city transportation and how HSR service providers, by enhancing their consumer logistics capabilities, can encourage intended HSR usage between San Francisco and Los Angeles for business commuter

Reduced Dimensional Optimal Vector Linear Index Codes for Index Coding Problems with Symmetric Neighboring and Consecutive Side-information

A single unicast index coding problem (SUICP) with symmetric neighboring and consecutive side-information (SNCS) has $K$ messages and $K$ receivers, the $k$th receiver $R_k$ wanting the $k$th message $x_k$ and having the side-information $\mathcal{K}_k=\{x_{k-U},\dots,x_{k-2},x_{k-1}\}\cup\{x_{k+1}, x_{k+2},\dots,x_{k+D}\}$. The single unicast index coding problem with symmetric neighboring and consecutive side-information, SUICP(SNCS), is motivated by topological interference management problems in wireless communication networks. Maleki, Cadambe and Jafar obtained the symmetric capacity of this SUICP(SNCS) and proposed optimal length codes by using Vandermonde matrices. In our earlier work, we gave optimal length $(U+1)$-dimensional vector linear index codes for SUICP(SNCS) satisfying some conditions on $K,D$ and $U$ \cite{VaR1}. In this paper, for SUICP(SNCS) with arbitrary $K,D$ and $U$, we construct optimal length $\frac{U+1}{\text{gcd}(K,D-U,U+1)}$-dimensional vector linear index codes. We prove that the constructed vector linear index code is of minimal dimension if $\text{gcd}(K-D+U,U+1)$ is equal to $\text{gcd}(K,D-U,U+1)$. The proposed construction gives optimal length scalar linear index codes for the SUICP(SNCS) if $(U+1)$ divides both $K$ and $D-U$. The proposed construction is independent of field size and works over every field. We give a low-complexity decoding for the SUICP(SNCS). By using the proposed decoding method, every receiver is able to decode its wanted message symbol by simply adding some index code symbols (broadcast symbols).Comment: 13 pages, 1 figure and 5 table