12,166 research outputs found
Mean-field calculation of critical parameters and log-periodic characterization of an aperiodic-modulated model
We employ a mean-field approximation to study the Ising model with aperiodic
modulation of its interactions in one spatial direction. Two different values
for the exchange constant, and , are present, according to the
Fibonacci sequence. We calculated the pseudo-critical temperatures for finite
systems and extrapolate them to the thermodynamic limit. We explicitly obtain
the exponents , , and and, from the usual scaling
relations for anisotropic models at the upper critical dimension (assumed to be
4 for the model we treat), we calculate , , , ,
and . Within the framework of a renormalization-group approach, the
Fibonacci sequence is a marginal one and we obtain exponents which depend on
the ratio , as expected. But the scaling relation is obeyed for all values of we studied. We characterize
some thermodynamic functions as log-periodic functions of their arguments, as
expected for aperiodic-modulated models, and obtain precise values for the
exponents from this characterization.Comment: 17 pages, including 9 figures, to appear in Phys. Rev.
Phase transition in a log-normal Markov functional model
We derive the exact solution of a one-dimensional Markov functional model
with log-normally distributed interest rates in discrete time. The model is
shown to have two distinct limiting states, corresponding to small and
asymptotically large volatilities, respectively. These volatility regimes are
separated by a phase transition at some critical value of the volatility. We
investigate the conditions under which this phase transition occurs, and show
that it is related to the position of the zeros of an appropriately defined
generating function in the complex plane, in analogy with the Lee-Yang theory
of the phase transitions in condensed matter physics.Comment: 9 pages, 5 figures. v2: Added asymptotic expressions for the
convexity-adjusted Libors in the small and large volatility limits. v3: Added
one reference. Final version to appear in Journal of Mathematical Physic
On the distribution of career longevity and the evolution of home run prowess in professional baseball
Statistical analysis is a major aspect of baseball, from player averages to
historical benchmarks and records. Much of baseball fanfare is based around
players exceeding the norm, some in a single game and others over a long
career. Career statistics serve as a metric for classifying players and
establishing their historical legacy. However, the concept of records and
benchmarks assumes that the level of competition in baseball is stationary in
time. Here we show that power-law probability density functions, a hallmark of
many complex systems that are driven by competition, govern career longevity in
baseball. We also find similar power laws in the density functions of all major
performance metrics for pitchers and batters. The use of performance-enhancing
drugs has a dark history, emerging as a problem for both amateur and
professional sports. We find statistical evidence consistent with
performance-enhancing drugs in the analysis of home runs hit by players in the
last 25 years. This is corroborated by the findings of the Mitchell Report [1],
a two-year investigation into the use of illegal steroids in major league
baseball, which recently revealed that over 5 percent of major league baseball
players tested positive for performance-enhancing drugs in an anonymous 2003
survey.Comment: 5 pages, 5 figures, 2-column revtex4 format. Revision has change of
title, a figure added, and minor changes in response to referee comment
An adjudicated hermeneutic single-case efficacy design study of experiential therapy for panic/phobia
This paper illustrates the application of an adjudicated form of Hermeneutic Single Case Efficacy Design (HSCED), a critical-reflective method for inferring change and therapeutic influence in single therapy cases. The client was a 61 year-old European-American male diagnosed with panic and bridge phobia. He was seen for 23 sessions of individual Process-Experiential/Emotion-Focused Therapy. In this study, affirmative and skeptic teams of researchers developed opposing arguments regarding whether the client changed over therapy and whether therapy was responsible for these changes. Three judges representing different theoretical orientations then assessed data and arguments, rendering judgments in favor of the affirmative side. We discuss clinical implications and recommendations for the future interpretive case study research
High Energy Photon-Photon Collisions at a Linear Collider
High intensity back-scattered laser beams will allow the efficient conversion
of a substantial fraction of the incident lepton energy into high energy
photons, thus significantly extending the physics capabilities of an
electron-electron or electron-positron linear collider. The annihilation of two
photons produces C=+ final states in virtually all angular momentum states. The
annihilation of polarized photons into the Higgs boson determines its
fundamental two-photon coupling as well as determining its parity. Other novel
two-photon processes include the two-photon production of charged lepton pairs,
vector boson pairs, as well as supersymmetric squark and slepton pairs and
Higgstrahlung. The one-loop box diagram leads to the production of pairs of
neutral particles. High energy photon-photon collisions can also provide a
remarkably background-free laboratory for studying possibly anomalous
collisions and annihilation. In the case of QCD, each photon can materialize as
a quark anti-quark pair which interact via multiple gluon exchange. The
diffractive channels in photon-photon collisions allow a novel look at the QCD
pomeron and odderon. Odderon exchange can be identified by looking at the heavy
quark asymmetry. In the case of electron-photon collisions, one can measure the
photon structure functions and its various components. Exclusive hadron
production processes in photon-photon collisions test QCD at the amplitude
level and measure the hadron distribution amplitudes which control exclusive
semi-leptonic and two-body hadronic B-decays.Comment: Invited talk, presented at the 5th International Workshop On
Electron-Electron Interactions At TeV Energies, Santa Cruz, California, 12-14
December 200
Some Properties of the Calogero-Sutherland Model with Reflections
We prove that the Calogero-Sutherland Model with reflections (the BC_N model)
possesses a property of duality relating the eigenfunctions of two Hamiltonians
with different coupling constants. We obtain a generating function for their
polynomial eigenfunctions, the generalized Jacobi polynomials. The symmetry of
the wave-functions for certain particular cases (associated to the root systems
of the classical Lie groups B_N, C_N and D_N) is also discussed.Comment: 16 pages, harvmac.te
Diffractive Higgs Production from Intrinsic Heavy Flavors in the Proton
We propose a novel mechanism for exclusive diffractive Higgs production in which the Higgs boson carries a significant fraction of the
projectile proton momentum. This mechanism will provide a clear experimental
signal for Higgs production due to the small background in this kinematic
region. The key assumption underlying our analysis is the presence of intrinsic
heavy flavor components of the proton bound state, whose existence at high
light-cone momentum fraction has growing experimental and theoretical
support. We also discuss the implications of this picture for exclusive
diffractive quarkonium and other channels.Comment: 30 pages, 5 figure
Beyond Blobs in Percolation Cluster Structure: The Distribution of 3-Blocks at the Percolation Threshold
The incipient infinite cluster appearing at the bond percolation threshold
can be decomposed into singly-connected ``links'' and multiply-connected
``blobs.'' Here we decompose blobs into objects known in graph theory as
3-blocks. A 3-block is a graph that cannot be separated into disconnected
subgraphs by cutting the graph at 2 or fewer vertices. Clusters, blobs, and
3-blocks are special cases of -blocks with , 2, and 3, respectively. We
study bond percolation clusters at the percolation threshold on 2-dimensional
square lattices and 3-dimensional cubic lattices and, using Monte-Carlo
simulations, determine the distribution of the sizes of the 3-blocks into which
the blobs are decomposed. We find that the 3-blocks have fractal dimension
in 2D and in 3D. These fractal dimensions are
significantly smaller than the fractal dimensions of the blobs, making possible
more efficient calculation of percolation properties. Additionally, the
closeness of the estimated values for in 2D and 3D is consistent with the
possibility that is dimension independent. Generalizing the concept of
the backbone, we introduce the concept of a ``-bone'', which is the set of
all points in a percolation system connected to disjoint terminal points
(or sets of disjoint terminal points) by disjoint paths. We argue that the
fractal dimension of a -bone is equal to the fractal dimension of
-blocks, allowing us to discuss the relation between the fractal dimension
of -blocks and recent work on path crossing probabilities.Comment: All but first 2 figs. are low resolution and are best viewed when
printe
Penggunaan Informasi Akuntansi Diferensial dalam Pengambilan Keputusan terhadap Pesanan Khusus pada Ud. Vanela
Informasi akuntansi diferensial merupakan salah satu jenis informasi yang dibutuhkan oleh manajemen sebagai dasar perencanaan dan pengambilan keputusan. Manajemen membutuhkan informasi akuntansi deferensial untuk membantu dalam pengambilan keputusan untuk menerima atau menolak pesanan khusus produk. Informasi akuntansi diferensial merupakan informasi akuntansi yang relevan berhubungan dengan pemilihan alternatif dimana didalamnya menyangkut pendapatan, biaya dan laba defernsial. Tujuan penelitian ini untuk menganalisis penggunan informasi akuntansi diferensial dalam pengambilan keputusan menerima atau menolak pesanan khusus pada UD. Vanela. Metode yang digunakan adalah analisis deskriptif dan kuantitatif. Hasil penelitian ini dilihat dari keputusan Perusahaan dalam menerima pesanan khususnya pada produk Pia Kacang Hijau sudah tepat, karena biaya-biaya yang relevan dengan pesanan khusus dibawah harga jual, sehingga dapat meningkatkan laba Perusahaan. Sebaiknya pihak manajemen UD. Vanela mempertimbangkan dalam menerima atau menolak pesanan khusus suatu produk, dan Perusahaan meneliti jumlah mengenai biaya yang seharusnya dipertimbangkan
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