4,108 research outputs found
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
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Riemann-Liouville while derivatives are of Caputo type.Comment: Submitted 26-Sept-2011; accepted 18-Oct-2011; withdrawn by the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
Optimal non-Markovian composite search algorithms for spatially correlated targets
We study the efficiency of a wide class of stochastic non-Markovian search strategies for spatially correlated target distributions. For an uninformed searcher that performs a non-composite random search, a ballistically moving search is optimal for destructible targets, even when the targets are correlated. For an informed searcher that can measure the time elapsed since the last target encounter and performs a composite search consisting of alternating extensive ballistic trajectories and intensive non-Markovian search trajectories, the efficiency can be more than three times higher compared to a ballistic searcher. We optimize the memory function that describes the intensive non-Markovian search motion and find a single-exponential memory function to be optimal. In our extended search model the intensive search mode is activated when the distance between two consecutively found targets in the extensive search mode is smaller than a threshold length called the memory distance dm. We find that a finite value of dm quite generally leads to optimal search efficiency for correlated target distributions
Stationarity-conservation laws for certain linear fractional differential equations
The Leibniz rule for fractional Riemann-Liouville derivative is studied in
algebra of functions defined by Laplace convolution. This algebra and the
derived Leibniz rule are used in construction of explicit form of
stationary-conserved currents for linear fractional differential equations. The
examples of the fractional diffusion in 1+1 and the fractional diffusion in d+1
dimensions are discussed in detail. The results are generalized to the mixed
fractional-differential and mixed sequential fractional-differential systems
for which the stationarity-conservation laws are obtained. The derived currents
are used in construction of stationary nonlocal charges.Comment: 28 page
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
The median nerve in the carpal tunnel
A study of the variations of the course and branching pattern of the median
nerve within the carpal tunnel were carried out on 60 wrists from 30 fresh
cadavers autopsied in the Department of Forensic Medicine of Jagiellonian
University Medical College. The results were compared with the literature. The
study confirmed that the extraligamentous type of motor branch variation is
most common. The transligamentous course of the nerve is of special importance:
it is usually accompanied by hypertrophic muscle, and the nerve hidden
within this muscle can easily be cut during transection of the retinaculum. The
results proved the necessity of approaching the median nerve from the ulnar
side when opening the carpal tunnel. (Folia Morphol 2011; 70, 1: 41-46
Statistical detection of systematic election irregularities
Democratic societies are built around the principle of free and fair
elections, that each citizen's vote should count equal. National elections can
be regarded as large-scale social experiments, where people are grouped into
usually large numbers of electoral districts and vote according to their
preferences. The large number of samples implies certain statistical
consequences for the polling results which can be used to identify election
irregularities. Using a suitable data collapse, we find that vote distributions
of elections with alleged fraud show a kurtosis of hundred times more than
normal elections on certain levels of data aggregation. As an example we show
that reported irregularities in recent Russian elections are indeed well
explained by systematic ballot stuffing and develop a parametric model
quantifying to which extent fraudulent mechanisms are present. We show that if
specific statistical properties are present in an election, the results do not
represent the will of the people. We formulate a parametric test detecting
these statistical properties in election results. Remarkably, this technique
produces similar outcomes irrespective of the data resolution and thus allows
for cross-country comparisons.Comment: For data see also
http://www.complex-systems.meduniwien.ac.at/elections/election.htm
Opinion Formation in Laggard Societies
We introduce a statistical physics model for opinion dynamics on random
networks where agents adopt the opinion held by the majority of their direct
neighbors only if the fraction of these neighbors exceeds a certain threshold,
p_u. We find a transition from total final consensus to a mixed phase where
opinions coexist amongst the agents. The relevant parameters are the relative
sizes in the initial opinion distribution within the population and the
connectivity of the underlying network. As the order parameter we define the
asymptotic state of opinions. In the phase diagram we find regions of total
consensus and a mixed phase. As the 'laggard parameter' p_u increases the
regions of consensus shrink. In addition we introduce rewiring of the
underlying network during the opinion formation process and discuss the
resulting consequences in the phase diagram.Comment: 5 pages, eps fig
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