6,369 research outputs found
THE EFFECT OF A CHANGING MARKET MIX IN SEED CORN ON INVENTORY COSTS
Changing product characteristics are causing U.S. seed corn companies to reevaluate their inventory strategies. A simulation model based upon the Economic Order Quantity model is built in @Risk to reflect a shortened product life cycle and product proliferation. Inventory costs levels increase because of increased uncertainty of demand. Empirical results find that shortening the product life cycle and expanding the product line increases total inventory costs by 120.8%, increases the average inventory level (primarily due to added safety stock) by 56.2%, and increases the cost of carryover, stockout cost, and safety stock cost by 143, 165, and 119 %, respectively. To maintain higher levels of customer service with products displaying shorter life cycles, more safety stock must be held to guard against stockouts.Crop Production/Industries,
The Impact of Tobacco Control Program Expenditures on Aggregate Cigarette Sales: 1981-1998
Since the 1998 Master Settlement Agreement between states and the tobacco industry, states have unprecedented resources for programs to reduce tobacco use. Decisions concerning the use of these funds will, in part, be based on the experiences of states with existing programs. We review the experiences of several states that have adopted comprehensive tobacco control programs. We also report estimates from econometric analyses of the impact of tobacco control expenditures on aggregate tobacco use in all states and in selected states with comprehensive programs for the period from 1981 through 1998. Our analyses clearly show that increases in funding for state tobacco control programs reduce tobacco use.
ASSESSING THE EFFECT OF ECR ON FINANCIAL AND OPERATING PERFORMANCE
A debate has emerged in the literature and trade press whether the adoption of Efficient Consumer Response (ECR), the supply chain management initiatives for the food industry, leads to improved inventory and financial performance. Using regression analysis, the financial performance for adopters of ECR is about 3 to 4% higher than for non-adopters. However, the growth in profit does not appear to come from improved performance for traditional inventory measures (such as inventory turnover, inventory-to-sales, or inventory-to-assets). The driving force behind these improved financial measures can be attributed to changes leading to a shorter cash conversion cycle. In addition, size matters; ECR is more effective due to economies of scale, information technology, and buying power.Industrial Organization,
Coherent Optomechanical State Transfer between Disparate Mechanical Resonators
Hybrid quantum systems have been developed with various mechanical, optical
and microwave harmonic oscillators. The coupling produces a rich library of
interactions including two mode squeezing, swapping interactions, back-action
evasion and thermal control. In a multimode mechanical system, coupling
resonators of different scales (both in frequency and mass) leverages the
advantages of each resonance. For example: a high frequency, easily manipulated
resonator could be entangled with a low frequency massive object for tests of
gravitational decoherence. Here we demonstrate coherent optomechanical state
swapping between two spatially and frequency separated resonators with a mass
ratio of 4. We find that, by using two laser beams far detuned from an optical
cavity resonance, efficient state transfer is possible through a process very
similar to STIRAP (Stimulated Raman Adiabatic Passage) in atomic physics.
Although the demonstration is classical, the same technique can be used to
generate entanglement between oscillators in the quantum regime
Experimental exploration of the optomechanical attractor diagram and its dynamics
We demonstrate experimental exploration of the attractor diagram of an
optomechanical system where the optical forces compensate for the mechanical
losses. In this case stable self-induced oscillations occur but only for
specific mirror amplitudes and laser detunings. We demonstrate that we can
amplify the mechanical mode to an amplitude 500 times larger than the thermal
amplitude at 300K. The lack of unstable or chaotic motion allows us to
manipulate our system into a non-trivial steady state and explore the dynamics
of self-induced oscillations in great detail.Comment: 6 pages, 4 figure
Probability and magnitude evaluation in schizophrenia
Alterations in reinforcement learning and decision making in schizophrenia have been linked with orbitofrontal cortex (OFC) dysfunction, a region critical for weighing reward magnitude in the calculation of expected value (EV). However, much of this work has used complex tasks that require combined learning and EV calculation. Here we used a simple “Roulette” task that examined the calculation of EV directly through a combination of text and/or pictorial representation of reward probability and magnitude. Forty-four people with schizophrenia and 30 controls were recruited. Patients were less sensitive to adjustments in a parameter combining probability and magnitude into one EV construct. Breaking down the construct into independent contributions of probability and magnitude, we found that negative symptoms were associated with magnitude sensitivity. This is consistent with the hypothesized role of OFC in actively representing magnitude and the notion that negative symptoms may involve a failure to appropriately estimate and use future reward magnitude to guide decision making
Area laws in quantum systems: mutual information and correlations
The holographic principle states that on a fundamental level the information
content of a region should depend on its surface area rather than on its
volume. This counterintuitive idea which has its roots in the nonextensive
nature of black-hole entropy serves as a guiding principle in the search for
the fundamental laws of Planck-scale physics. In this paper we show that a
similar phenomenon emerges from the established laws of classical and quantum
physics: the information contained in part of a system in thermal equilibrium
obeys an area law. While the maximal information per unit area depends
classically only on the number of microscopic degrees of freedom, it may
diverge as the inverse temperature in quantum systems. A rigorous relation
between area laws and correlations is established and their explicit behavior
is revealed for a large class of quantum many-body states beyond equilibrium
systems.Comment: 5 pages, 2 figures, published version with appendi
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