5,853 research outputs found
A national survey of in-service staff activities and projects in business education.
Thesis (M.Ed.)--Boston Universit
A Structural Model of Demand, Cost, and Export Market Selection for Chinese Footwear Producers
In this paper we use micro data on both trade and production for a sample of large Chinese manufacturing firms in the footwear industry from 2002-2006 to estimate an empirical model of export demand, pricing, and market participation by destination market. We use the model to construct indexes of firm-level demand, cost, and export market profitability. The empirical results indicate substantial firm heterogeneity in both the demand and cost dimensions with demand being more dispersed. The firm-specific demand and cost components are very useful in explaining differences in the extensive margin of trade, the length of time a firm exports to a destination, and the number and mix of destinations, as well as the export prices, while cost is more important in explaining the quantity of firm exports on the intensive margin. We use the estimates to analyze the reallocation resulting from removal of the quota on Chinese footwear exports to the EU and find that it led to a rapid restructuring of export supply sources in favor of firms with high demand and low cost indexes.
Plasmonic edge states: an electrostatic eigenmode description
We consider periodic arrangements of metal nanostructures and study the
effect of periodicity on the localised surface plasmon resonance of the
structures within an electrostatic eigenmode approximation. We show that within
this limit, the collective surface plasmon resonances of the periodic
structures can be expressed in terms of superpositions of the eigenmodes of
uncoupled nanostructures that exhibit a standing--wave character delocalised
across the entire periodic structure. The formalism derived successfully
enables the design and accounts for the observation of plasmonic edge-states in
periodic structures
Entry, exit and the determinants of market structure
Market structure is determined by the entry and exit decisions of individual producers. These decisions are driven by expectations of future profits which, in turn, depend on the nature of competition within the market. In this paper we estimate a dynamic, structural model of entry and exit in an oligopolistic industry and use it to quantify the determinants of market structure and long-run firm values for two U.S. service industries, dentists and chiropractors. We find that entry costs faced by potential entrants, fixed costs faced by incumbent producers, and the toughness of short-run price competition are all important determinants of long run firm values and market structure. As the number of firms in the market increases, the value of continuing in the market and the value of entering the market both decline, the probability of exit rises, and the probability of entry declines. The magnitude of these effects differ substantially across markets due to differences in exogenous cost and demand factors and across the dentist and chiropractor industries. Simulations using the estimated model for the dentist industry show that pressure from both potential entrants and incumbent firms discipline long-run profits. We calculate that a seven percent reduction in the mean sunk entry cost would reduce a monopolist's long-run profits by the same amount as if the firm operated in a duopoly.Markets ; Competition ; Service industries
Fixed-head star tracker magnitude calibration on the solar maximum mission
The sensitivity of the fixed-head star trackers (FHSTs) on the Solar Maximum Mission (SMM) is defined as the accuracy of the electronic response to the magnitude of a star in the sensor field-of-view, which is measured as intensity in volts. To identify stars during attitude determination and control processes, a transformation equation is required to convert from star intensity in volts to units of magnitude and vice versa. To maintain high accuracy standards, this transformation is calibrated frequently. A sensitivity index is defined as the observed intensity in volts divided by the predicted intensity in volts; thus, the sensitivity index is a measure of the accuracy of the calibration. Using the sensitivity index, analysis is presented that compares the strengths and weaknesses of two possible transformation equations. The effect on the transformation equations of variables, such as position in the sensor field-of-view, star color, and star magnitude, is investigated. In addition, results are given that evaluate the aging process of each sensor. The results in this work can be used by future missions as an aid to employing data from star cameras as effectively as possible
Retrograde transport pathways utilised by viruses and protein toxins
A model has been presented for retrograde transport of certain toxins and viruses from the cell surface to the ER that suggests an obligatory interaction with a glycolipid receptor at the cell surface. Here we review studies on the ER trafficking cholera toxin, Shiga and Shiga-like toxins, Pseudomonas exotoxin A and ricin, and compare the retrograde routes followed by these protein toxins to those of the ER trafficking SV40 and polyoma viruses. We conclude that there is in fact no obligatory requirement for a glycolipid receptor, nor even with a protein receptor in a lipid-rich environment. Emerging data suggests instead that there is no common pathway utilised for retrograde transport by all of these pathogens, the choice of route being determined by the particular receptor utilised
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