3,961 research outputs found
Matrix Cartan superdomains, super Toeplitz operators, and quantization
We present a general theory of non-perturbative quantization of a class of
hermitian symmetric supermanifolds. The quantization scheme is based on the
notion of a super Toeplitz operator on a suitable Z_2 -graded Hilbert space of
superholomorphic functions. The quantized supermanifold arises as the C^*
-algebra generated by all such operators. We prove that our quantization
framework reproduces the invariant super Poisson structure on the classical
supermanifold as Planck's constant tends to zero.Comment: 52
Parkinson's Law Quantified: Three Investigations on Bureaucratic Inefficiency
We formulate three famous, descriptive essays of C.N. Parkinson on
bureaucratic inefficiency in a quantifiable and dynamical socio-physical
framework. In the first model we show how the use of recent opinion formation
models for small groups can be used to understand Parkinson's observation that
decision making bodies such as cabinets or boards become highly inefficient
once their size exceeds a critical 'Coefficient of Inefficiency', typically
around 20. A second observation of Parkinson - which is sometimes referred to
as Parkinson's Law - is that the growth of bureaucratic or administrative
bodies usually goes hand in hand with a drastic decrease of its overall
efficiency. In our second model we view a bureaucratic body as a system of a
flow of workers, which enter, become promoted to various internal levels within
the system over time, and leave the system after having served for a certain
time. Promotion usually is associated with an increase of subordinates. Within
the proposed model it becomes possible to work out the phase diagram under
which conditions bureaucratic growth can be confined. In our last model we
assign individual efficiency curves to workers throughout their life in
administration, and compute the optimum time to send them to old age pension,
in order to ensure a maximum of efficiency within the body - in Parkinson's
words we compute the 'Pension Point'.Comment: 15 pages, 5 figure
Supersymmetry and Fredholm modules over quantized spaces
The purpose of this paper is to apply the framework of non- commutative
differential geometry to quantum deformations of a class of Kahler manifolds.
For the examples of the Cartan domains of type I and flat space, we construct
Fredholm modules over the quantized manifolds using the supercharges which
arise in the quantization of supersymmetric generalizations of the manifolds.
We compute the explicit formula for the Chern character on generators of the
Toeplitz C^* -algebra.Comment: 24
Entrant Experience and Plant Exit
Producers entering a market can differ widely in their prior production experience, ranging from none to extensive experience in related geographic or product markets. In this paper, we quantify the nature of prior plant and firm experience for entrants into a market and measure its effect on the plant's decision to exit the market. Using plant-level data for seven regional manufacturing industries in the U.S., we find that a producer's experience at the time it enters a market plays an important role in the subsequent exit decision, affecting both the overall probability of exit and the method of exit. After controlling for observable plant and market profit determinants, there remain systematic differences in failure patterns across three groups of plants distinguished by their prior experience: de novo entrants, experienced plants that enter by diversifying their product mix, and new plants owned by experienced firms. The results indicate that the exit decision cannot be treated as determined solely by current and future plant, firm, and market conditions, but that the plant's history plays an important independent role in conditioning the likelihood of survival.
The dynamics of market structure and market size in two health services industries
The relationship between the size of a market and the competitiveness of the market has been of long-standing interest to IO economists. Empirical studies have used the relationship between the size of the geographic market and both the number of firms in the market and the average sales of the firms to draw inferences about the degree of competition in the market. This paper extends this framework to incorporate the analysis of entry and exit flows. A key implication of recent entry and exit models is that current market structure will likely depend upon the history of past participation. The paper explores these issues empirically by examining producer dynamics for two health service industries, dentistry and chiropractic services.Markets ; Industrial organization ; Service industries
Fractional Hamilton formalism within Caputo's derivative
In this paper we develop a fractional Hamiltonian formulation for dynamic
systems defined in terms of fractional Caputo derivatives. Expressions for
fractional canonical momenta and fractional canonical Hamiltonian are given,
and a set of fractional Hamiltonian equations are obtained. Using an example,
it is shown that the canonical fractional Hamiltonian and the fractional
Euler-Lagrange formulations lead to the same set of equations.Comment: 8 page
Fractional variational calculus of variable order
We study the fundamental problem of the calculus of variations with variable
order fractional operators. Fractional integrals are considered in the sense of
Riemann-Liouville while derivatives are of Caputo type.Comment: Submitted 26-Sept-2011; accepted 18-Oct-2011; withdrawn by the
authors 21-Dec-2011; resubmitted 27-Dec-2011; revised 20-March-2012; accepted
13-April-2012; to 'Advances in Harmonic Analysis and Operator Theory', The
Stefan Samko Anniversary Volume (Eds: A. Almeida, L. Castro, F.-O. Speck),
Operator Theory: Advances and Applications, Birkh\"auser Verlag
(http://www.springer.com/series/4850
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