2,648 research outputs found
Impacts of Fat and Cholesterol Information On Consumer Demand: Application of New Indexes
Consumers' beliefs in the benefits of reducing fat intakes, especially saturated fat, and of increasing calcium intake from such foods as dairy products, depend upon the acquired information related to diet and health. This study develops new health information measures from different sources. The monthly information indexes, constructed for 1980-93, show that the amount of consumer information related to fat and cholesterol in circulation reached the highest levels during 1989-90. The results from an empirical application show that these new indexes of consumer health information about fats and cholesterol could explain the changing patterns of consumer choice for whole milk vs. lower fat milk in the United States.Demand and Price Analysis,
transitions in the light cone sum rules with the chiral current
semi-leptonic decays to the light scalar meson, , are investigated in the QCD
light-cone sum rules (LCSR) with chiral current correlator. Having little
knowledge of ingredients of the scalar mesons, we confine ourself to the two
quark picture for them and work with the two possible Scenarios. The resulting
sum rules for the form factors receive no contributions from the twist-3
distribution amplitudes (DA's), in comparison with the calculation of the
conventional LCSR approach where the twist-3 parts play usually an important
role. We specify the range of the squared momentum transfer , in which the
operator product expansion (OPE) for the correlators remains valid
approximately. It is found that the form factors satisfy a relation consistent
with the prediction of soft collinear effective theory (SCET). In the effective
range we investigate behaviors of the form factors and differential decay
widthes and compare our calculations with the observations from other
approaches. The present findings can be beneficial to experimentally identify
physical properties of the scalar mesons.Comment: 22 pages,16 figure
Inverse Optimization with Noisy Data
Inverse optimization refers to the inference of unknown parameters of an
optimization problem based on knowledge of its optimal solutions. This paper
considers inverse optimization in the setting where measurements of the optimal
solutions of a convex optimization problem are corrupted by noise. We first
provide a formulation for inverse optimization and prove it to be NP-hard. In
contrast to existing methods, we show that the parameter estimates produced by
our formulation are statistically consistent. Our approach involves combining a
new duality-based reformulation for bilevel programs with a regularization
scheme that smooths discontinuities in the formulation. Using epi-convergence
theory, we show the regularization parameter can be adjusted to approximate the
original inverse optimization problem to arbitrary accuracy, which we use to
prove our consistency results. Next, we propose two solution algorithms based
on our duality-based formulation. The first is an enumeration algorithm that is
applicable to settings where the dimensionality of the parameter space is
modest, and the second is a semiparametric approach that combines nonparametric
statistics with a modified version of our formulation. These numerical
algorithms are shown to maintain the statistical consistency of the underlying
formulation. Lastly, using both synthetic and real data, we demonstrate that
our approach performs competitively when compared with existing heuristics
Local Water Storage Control for the Developing World
Most cities in India do not have water distribution networks that provide
water throughout the entire day. As a result, it is common for homes and
apartment buildings to utilize water storage systems that are filled during a
small window of time in the day when the water distribution network is active.
However, these water storage systems do not have disinfection capabilities, and
so long durations of storage (i.e., as few as four days) of the same water
leads to substantial increases in the amount of bacteria and viruses in that
water. This paper considers the stochastic control problem of deciding how much
water to store each day in the system, as well as deciding when to completely
empty the water system, in order to tradeoff: the financial costs of the water,
the health costs implicit in long durations of storing the same water, the
potential for a shortfall in the quantity of stored versus demanded water, and
water wastage from emptying the system. To solve this problem, we develop a new
Binary Dynamic Search (BiDS) algorithm that is able to use binary search in one
dimension to compute the value function of stochastic optimal control problems
with controlled resets to a single state and with constraints on the maximum
time span in between resets of the system
Permanent Concrete Pavement Markings
The visibility, durability, and cost-effectiveness of surface pavement markings and previous experience with permanent concrete pavement markings (PCPM) (markings with a service life similar to that of the pavement) are described. The use of durable materials, such as thermoplastics, polyesters, and epoxies, improves the service life of surface markings. However, these marking materials still exhibit problems of adhesion to pavement and rapid wear in high traffic areas. Snow removal procedures significantly reduce marking service life. Wet nighttime visibility is a continuing problem with surface markings. Previous attempts at developing PCPM have produced systems with very good durability, but poor nighttime visibility. The potential for developing cost-effective PCPM systems that can provide both long-term durability and adequate visibility throughout the service life and the requirements for such systems are discussed. Polymers, such as epoxies, can provide superior durability and adhesion to pavement. The application of larger than standard size glass beads can improve wet nighttime visibility. The cost of PCPM systems can be significantly reduced using effective methods of placing grooves in which the marking material is placed. Generally, there is a good probability that a cost-effective PCPM system with satisfactory durability and visibility can be developed. The PCPM systems with thicknesses of 9.5 mm (3/8 in.) or less will be cost-effective for a 20- year service life, and the systems with thicknesses of 3.2 mm (1/8 in.) or less will be costeffective for a I 0-year service life
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