50,682 research outputs found
The Exchange Value Embedded In A Transport System
This paper shows that a well designed transport system has an embedded
exchange value by serving as a market for potential exchange between consumers.
Under suitable conditions, one can improve the welfare of consumers in the
system simply by allowing some exchange of goods between consumers during
transportation without incurring additional transportation costs. We propose an
explicit valuation formula to measure this exchange value for a given
compatible transport system. This value is always nonnegative and bounded from
above. Criteria based on transport structures, preferences and prices are
provided to determine the existence of a positive exchange value. Finally, we
study a new optimal transport problem with an objective taking into account of
both transportation cost and exchange value.Comment: 20 pages, 6 figure
On the Ramified Optimal Allocation Problem
This paper proposes an optimal allocation problem with ramified transport
technology in a spatial economy. Ramified transportation is used to model the
transport economy of scale in group transportation observed widely in both
nature and efficiently designed transport systems of branching structures. The
ramified allocation problem aims at finding an optimal allocation plan as well
as an associated optimal allocation path to minimize overall cost of
transporting commodity from factories to households. This problem
differentiates itself from existing ramified transportation literature in that
the distribution of production among factories is not fixed but endogenously
determined as observed in many allocation practices. It's shown that due to the
transport economy of scale in ramified transportation, each optimal allocation
plan corresponds equivalently to an optimal assignment map from households to
factories. This optimal assignment map provides a natural partition of both
households and allocation paths. We develop methods of marginal transportation
analysis and projectional analysis to study properties of optimal assignment
maps. These properties are then related to the search for an optimal assignment
map in the context of state matrix.Comment: 36 pages, 8 figure
On Max-SINR Receiver for Hexagonal Multicarrier Transmission Over Doubly Dispersive Channel
In this paper, a novel receiver for Hexagonal Multicarrier Transmission (HMT)
system based on the maximizing Signal-to-Interference-plus-Noise Ratio
(Max-SINR) criterion is proposed. Theoretical analysis shows that the prototype
pulse of the proposed Max-SINR receiver should adapt to the root mean square
(RMS) delay spread of the doubly dispersive (DD) channel with exponential power
delay profile and U-shape Doppler spectrum. Simulation results show that the
proposed Max-SINR receiver outperforms traditional projection scheme and
obtains an approximation to the theoretical upper bound SINR performance within
the full range of channel spread factor. Meanwhile, the SINR performance of the
proposed prototype pulse is robust to the estimation error between the
estimated value and the real value of time delay spread.Comment: 6 pages. The paper has been published in Proc. IEEE GLOBECOM 2012.
Copyright transferred to IEEE. arXiv admin note: text overlap with
arXiv:1212.579
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