2,284,967 research outputs found
Estimating the damage and marginal cost of different vehicle types on rail infrastructure: combining economic and engineering approaches
EU legislation requires that European infrastructure managers set access charges based on the marginal cost of running trains on their networks. Two methods have been used in the literature for this purpose. Top-down methods relate actual costs to traffic volumes. Bottom-up methods use engineering models to simulate damage and then translate damage into costs based on assumptions about interventions and their unit costs. Whilst top down methods produce sensible results for marginal cost overall, they have struggled to differentiate between traffic types. The challenge for bottom-up approaches is how to translate damage into cost, with numerous assumptions being required which may be invalid.
This paper proposes a new, two stage approach to estimating the marginal cost of rail infrastructure usage. The first stage uses engineering models to simulate damage caused by vehicles on the network. The second stage seeks to establish a statistical relationship between actual costs and damage. It is thus possible to convert damage estimates into costs using actual cost data, rather than through a set of potentially invalid assumptions as in previous approaches.
Only the first stage is implemented in this paper. We show that it possible to produce total (annualised) damage measures for three damage mechanisms on five actual track sections in Sweden. Once extended, it will be possible to model the relationship between damage and actual costs for the first time; and thus better understand the relative costs of the different damage mechanisms and in turn inform the level and structure of track access charges
Factoring the Cycle Aging Cost of Batteries Participating in Electricity Markets
When participating in electricity markets, owners of battery energy storage
systems must bid in such a way that their revenues will at least cover their
true cost of operation. Since cycle aging of battery cells represents a
substantial part of this operating cost, the cost of battery degradation must
be factored in these bids. However, existing models of battery degradation
either do not fit market clearing software or do not reflect the actual battery
aging mechanism. In this paper we model battery cycle aging using a piecewise
linear cost function, an approach that provides a close approximation of the
cycle aging mechanism of electrochemical batteries and can be incorporated
easily into existing market dispatch programs. By defining the marginal aging
cost of each battery cycle, we can assess the actual operating profitability of
batteries. A case study demonstrates the effectiveness of the proposed model in
maximizing the operating profit of a battery energy storage system taking part
in the ISO New England energy and reserve markets
Dynamical complexity in the perception-based network formation model
Many link formation mechanisms for the evolution of social networks have been
successful to reproduce various empirical findings in social networks. However,
they have largely ignored the fact that individuals make decisions on whether
to create links to other individuals based on cost and benefit of linking, and
the fact that individuals may use perception of the network in their decision
making. In this paper, we study the evolution of social networks in terms of
perception-based strategic link formation. Here each individual has her own
perception of the actual network, and uses it to decide whether to create a
link to another individual. An individual with the least perception accuracy
can benefit from updating her perception using that of the most accurate
individual via a new link. This benefit is compared to the cost of linking in
decision making. Once a new link is created, it affects the accuracies of other
individuals' perceptions, leading to a further evolution of the actual network.
As for initial actual networks, we consider homogeneous and heterogeneous
cases. The homogeneous initial actual network is modeled by Erd\H{o}s-R\'enyi
(ER) random networks, while we take a star network for the heterogeneous case.
In any cases, individual perceptions of the actual network are modeled by ER
random networks with controllable linking probability. Then the stable link
density of the actual network is found to show discontinuous transitions or
jumps according to the cost of linking. As the number of jumps is the
consequence of the dynamical complexity, we discuss the effect of initial
conditions on the number of jumps to find that the dynamical complexity
strongly depends on how much individuals initially overestimate or
underestimate the link density of the actual network. For the heterogeneous
case, the role of the highly connected individual as an information spreader is
discussed.Comment: 8 pages, 7 figure
Cost management in the conditions of the actual world financial crisis
In this article we outlined the importance of the costs of providing the necessary information to the management in order to take the best decisions in crisis conditions. We considered the following objectives that an enterprise should have in the conditions of an unfavourable economic environment: the importance of the costs with the wages in the cost structure of the enterprise, the analysis of the hidden costs, the investment policy in crisis conditions, the expenses with financing on short term, the readjustment of the commercial contracts and limiting the expenses with external labour conscription, the sales growth policy by diminishing the advertising expenses.Managerial accounting, internal transfer prices, hidden costs.
Contractor project estimates vs. consultant project estimates in Ghana
Ten projects constructed in Ghana between 2003 and 2010 are examined and analysed to ascertain the reliability of estimated costs provided for the projects. Cost estimates for five of the projects were calculated by consultants and cost estimates for the five remaining projects were calculated by contractors. Cost estimates prepared by contractors seemed to be closer to actual costs than estimates calculated by consultants. Projects estimated by consultants experienced an average cost overrun of 40% and time overrun of 62% whereas projects priced by contractors experienced an average cost overrun of 6% and time overrun of 41%. It seemed that contractors had a better understanding of the actual construction processes and a clearer expectation of the needs of the client hence an ability to calculate estimates that were closer to reality. Construction clients in Ghana should rely on contractors for more realistic cost estimates as estimates by consultants may be inaccurate. Where consultants are employed, an allowance of up 40% should be added to the estimated costs as a margin for inaccuracy
The Costs and Benefits of a Comprehensive Induction Program
Until now there have been no benefit-cost studies of mentoring programs for beginning teachers to provide legislators, educational administrators, and program leaders with the kind of economic information they need for informed decision making. In a benefit-cost analysis we estimate the financial benefits of a given course of action against the actual costs, and use the resulting balance to guide decision making. Costs are either one-time, or may be ongoing. Benefits are most often received over time. In its simple form, benefit-cost analysis is carried out using only actual financial costs and financial benefits. A more sophisticated approach attempts also to put a financial value on intangible costs and benefits, a process that can be highly subjective. In order to provide an estimate of the potential return on the investment in a comprehensive mentoring program for beginning teachers we collected actual cost data for the Santa Cruz New Teacher Project across all its local contexts,calculated the measured benefits, assigning them a monetary value where possible, and computed the net present value over five years. We looked at net benefits or costs from multiple perspectives: the state, the district, the school, the teacher, and the student. The total of all these represents the net benefit or cost to society.calculated the measured benefits, assigning them a monetary value where possible, and computed the net present value over five years. We looked at net benefits or costs from multiple perspectives: the state, the district, the school, the teacher, and the student. The total of all these represents the net benefit or cost to society
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