29,256 research outputs found
An Empirical Model for Optimal Highway Durability in Cold Regions
We develop an empirical tool to estimate optimal highway durability in cold regions. To test the model, we assemble a data set containing all highway construction and maintenance projects in Arizona and Washington State from 1990 to 2014. The data set includes information on location, time, type (resurfacing, construction, or lane widening), pavement material and thickness, and total expenditure for these projects. Using the data, we first estimate how highway maintenance costs and highway duration depend on pavement thickness and traffic loading. We then calibrate the effects of different deicers on highway durability and thus on highway maintenance costs. Finally, we demonstrate how the estimated and calibrated model can be used by planners to make optimal decisions for highway pavement and winter operations in cold regions
US Highway Privatization and Heterogeneous Preferences
Abstract: We assess the welfare effects of highway privatization accounting for government’s behavior in setting the sale price, firms’ strategic behavior in setting tolls in various competitive environments, and motorists’ heterogeneous preferences for speedy and reliable travel. We conclude motorists can benefit from privatization if they are able to negotiate aggressively with a private provider to obtain tolls and service that align with their varying preferences. Surprisingly, motorists are likely to be better off negotiating with a monopolist than with duopoly providers or under public-private competition. Toll regulation may be counterproductive because it would treat motorists as homogeneous. Revised June 2009.Security Breach Costs; Financial Distress; Insurance; Resource Allocation.
On certain recurrent and automatic sequences in finite fields
In this work we extend our study on a link between automaticity and certain
algebraic power series over finite fields. Our starting point is a family of
sequences in a finite field of characteristic , recently introduced by the
first author in connection with algebraic continued fractions. By including it
in a large family of recurrent sequences in an arbitrary finite field, we prove
its automaticity. Then we give a criterion on automatic sequences, generalizing
a previous result and this allows us to present new families of automatic
sequences in an arbitrary finite field.Comment: 10 page
Hyperquadratic continued fractions over a finite field of odd characteristic with partial quotients of degree 1
In 1986, some examples of algebraic, and nonquadratic, power series over a
finite prime field, having a continued fraction expansion with partial
quotients all of degree one, were discovered by W. Mills and D. Robbins. In
this note we show how these few examples are included in a very large family of
continued fractions for certain algebraic power series over an arbitrary finite
field of odd characteristic
The Value of "Value Pricing" of Roads: Second-Best Pricing and Product Differentiation
Some road-pricing demonstrations use an approach called "value pr icing", in which travelers can choose between a free but congested roadway and a priced roadway. Recent research has uncovered a potentially serious problem for such demonstrations: in certain models, second-best tolls are far lower than those typically charged, and the welfare gains from profit maximization are small or even negative. That research, however , assumes that all travelers are identical, and it therefore neglects the benefits of product differentiation, by which people with different values of time can choose a suitable cost/quality combination. Using a model with two user groups, we find that accounting for heterogeneity in value of time is important in evaluating constrained policies, and improves the relative performance of policies that offer differential prices. Nevertheless, for most of the reasonable range of heterogeneity, second-best pricing produces far fewer benefits than pricing both roadways optimally, and profit-maximizing tolls are so high that over all welfare is reduced from the no-toll baseline.
Instability of Dynamic Inventory Systems
We show in this paper that instability is an intrinsic cause of production variability in a dynamic inventory system. We first show that a unique stationary optimal policy exists for both full-backlog and lost-sales case and under the policy a firm replenishes its inventory to a constant target level. We then express the constant inventory target as the unique steady state of the Euler’s equation governing the dynamics of target inventories. We finally show that the Euler’s equation is locally instable at the steady state but a sufficiently large refund to unsold inventory in lost-sales case can stabilize the inventory system.stability, production variability, dynamic inventory system, full-backlog, lost-sales
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