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The three-dimensional Ising model: A paradigm of liquid-vapor coexistence in nuclear multifragmentation  [PDF]
C. M. Mader,A. Chappars,J. B. Elliott,L. G. Moretto,L. Phair,G. J. Wozniak
Physics , 2001, DOI: 10.1103/PhysRevC.68.064601
Abstract: Clusters in the three-dimensional Ising model rigorously obey reducibility and thermal scaling up to the critical temperature. The barriers extracted from Arrhenius plots depend on the cluster size as $B \propto A^{\sigma}$ where $\sigma$ is a critical exponent relating the cluster size to the cluster surface. All the Arrhenius plots collapse into a single Fisher-like scaling function indicating liquid-vapor-like phase coexistence and the univariant equilibrium between percolating clusters and finite clusters. The compelling similarity with nuclear multifragmentation is discussed.
The liquid to vapor phase transition in excited nuclei  [PDF]
J. B. Elliott,L. G. Moretto,L. Phair,G. J. Wozniak,T. Lefort,L. Beaulieu,K. Kwiatkowski,W. -C. Hsi,L. Pienkowski,H. Breuer,R. G. Korteling,R. Laforest,E. Martin,E. Ramakrishnan,D. Rowland,A. Ruangma,V. E. Viola,E. Winchester,S. J. Yennello
Physics , 2001, DOI: 10.1103/PhysRevLett.88.042701
Abstract: For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid- vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.
On the criticality of inferred models  [PDF]
Iacopo Mastromatteo,Matteo Marsili
Quantitative Finance , 2011, DOI: 10.1088/1742-5468/2011/10/P10012
Abstract: Advanced inference techniques allow one to reconstruct the pattern of interaction from high dimensional data sets. We focus here on the statistical properties of inferred models and argue that inference procedures are likely to yield models which are close to a phase transition. On one side, we show that the reparameterization invariant metrics in the space of probability distributions of these models (the Fisher Information) is directly related to the model's susceptibility. As a result, distinguishable models tend to accumulate close to critical points, where the susceptibility diverges in infinite systems. On the other, this region is the one where the estimate of inferred parameters is most stable. In order to illustrate these points, we discuss inference of interacting point processes with application to financial data and show that sensible choices of observation time-scales naturally yield models which are close to criticality.
Can Facial Uniqueness be Inferred from Impostor Scores?  [PDF]
Abhishek Dutta,Raymond Veldhuis,Luuk Spreeuwers
Computer Science , 2013,
Abstract: In Biometrics, facial uniqueness is commonly inferred from impostor similarity scores. In this paper, we show that such uniqueness measures are highly unstable in the presence of image quality variations like pose, noise and blur. We also experimentally demonstrate the instability of a recently introduced impostor-based uniqueness measure of [Klare and Jain 2013] when subject to poor quality facial images.
Line Structures in Recurrence Plots  [PDF]
Norbert Marwan,Juergen Kurths
Physics , 2004, DOI: 10.1016/j.physleta.2004.12.056
Abstract: Recurrence plots exhibit line structures which represent typical behaviour of the investigated system. The local slope of these line structures is connected with a specific transformation of the time scales of different segments of the phase-space trajectory. This provides us a better understanding of the structures occuring in recurrence plots. The relationship between the time-scales and line structures are of practical importance in cross recurrence plots. Using this relationship within cross recurrence plots, the time-scales of differently sampled or time-transformed measurements can be adjusted. An application to geophysical measurements illustrates the capability of this method for the adjustment of time-scales in different measurements.
The uniqueness of the Fisher metric as information metric  [PDF]
H?ng Van Lê
Statistics , 2013,
Abstract: We define a mixed topology on the fiber space $\cup_\mu \oplus^n L^n(\mu)$ over the space $\Mm(\Om)$ of all finite non-negative measures $\mu$ on a separable metric space $\Om$ provided with Borel $\sigma$-algebra. We define a notion of strong continuity of a covariant $n$-tensor field on $\Mm(\Om)$. Under the assumption of strong continuity of an information metric we prove the uniqueness of the Fisher metric as information metric on statistical models associated with $\Om$. Our proof realizes a suggestion due to Amari and Nagaoka to derive the uniqueness of the Fisher metric from the special case proved by Chentsov by using a special kind of limiting procedure. The obtained result extends the monotonicity characterization of the Fisher metric on statistical models associated with finite sample spaces and complement the uniqueness theorem by Ay-Jost-L\^e-Schwachh\"ofer that characterizes the Fisher metric by its invariance under sufficient statistics. As a by-product we discover a class of regular statistical models that enjoy nice properties.
Computing alignment plots efficiently  [PDF]
Peter Krusche,Alexander Tiskin
Computer Science , 2009,
Abstract: Dot plots are a standard method for local comparison of biological sequences. In a dot plot, a substring to substring distance is computed for all pairs of fixed-size windows in the input strings. Commonly, the Hamming distance is used since it can be computed in linear time. However, the Hamming distance is a rather crude measure of string similarity, and using an alignment-based edit distance can greatly improve the sensitivity of the dot plot method. In this paper, we show how to compute alignment plots of the latter type efficiently. Given two strings of length m and n and a window size w, this problem consists in computing the edit distance between all pairs of substrings of length w, one from each input string. The problem can be solved by repeated application of the standard dynamic programming algorithm in time O(mnw^2). This paper gives an improved data-parallel algorithm, running in time $O(mnw/\gamma/p)$ using vector operations that work on $\gamma$ values in parallel and $p$ processors. We show experimental results from an implementation of this algorithm, which uses Intel's MMX/SSE instructions for vector parallelism and MPI for coarse-grained parallelism.
Efficiency of Inventory in Uneven-Aged Forests on Sample Plots with Different Radii
Anamarija Jazbec,Mislav Vedri?,Mario Bo?i?,Ernest Gor?i?
Croatian Journal of Forest Engineering , 2011,
Abstract: For the purpose of forest management planning in Croatia, forest inventory is performed on sample plots of permanent sizes, generally from 500 to 1,000 m2. Such plots have been accepted in practice on the basis of experience. Thus, the plot size has only partially been adjusted to different forest types. Although methods of sample selection are regulated by Forest Management Regulations and are limited to plots of permanent sizes, the Regulations still allow plot sizes to be adjusted to specific stand conditions. This article compares the results of forest measurement on differently sized plots in order to estimate their efficiency in selection fir and beech stands. Research was carried out in Gorski Kotar, where the stand structure was recorded using a sample of experimental plots. Systematic sampling with a random start was used to establish 103 sample plots in the management units of Delnice and RavnaGora . Breast height diameters over 10 cm and tree heightsweremeasured on circular plots of 20mradius, set up across a 100 x 100 m square grid, and their positions in the space (azimuth and distance from the centre) were recorded. The values of structural elements (number of trees, basal area and volume) were calculated from the obtained data bymeans of a specially constructed computer programme CirCon for the plots and stands. The precision of estimates was expressed as a relative sample error with 95% confidence. Thanks to spatial data for all the trees, a calculation was made of the structure for sample plots in the radius range from 4 to 20 m. The precision of structural elements estimate (sample error) was calculated for each plot size. The average values in differently sized plots were compared with repeated measurement analysis of variance (RM ANOVA) with significance level of 0.05. The results of different plot sizes were subsequently tested by means of the Fisher’s LSD 'post hoc' test. On a sub-sample of 24 standpoints, the time needed for field measurements on differently sized plots was later measured in order to estimate the efficiency of differently sized plots. From these data measurement time (t) for all plot sizes was assessed in dependence on plot area (P) using the equation t=a*P b. Walking time and distance between the plots were measured, from which the travel speed in the field was calculated. The efficiency of plots of a particular size was evaluated by the precision of estimate and the time needed for measurements. The achieved efficiency index was evaluated as the product of squared sample error and total time expressed in relat
Ternary Plots for Neutrino Mixing Visualization  [PDF]
Cosmas K. Zachos
Physics , 2012, DOI: 10.1209/0295-5075/99/11001
Abstract: The visualization advantages of ternary plots are illustrated for the PMNS neutrino mixing matrix. Unitarity constraints are incorporated automatically, in part, since barycentric plots of this type allow three variables with a fixed sum to be plotted as mere points inside an equilateral triangle on a plane.
Sensitivity plots for WIMP modulation searches  [PDF]
S. Scopel,S. Cebrian,E. Garcia,D. Gonzalez,I. G. Irastorza,A. Morales,J. Morales,A. Ortiz de Solorzano,A. Peruzzi,J. Puimedon,M. L. Sarsa,J. A. Villar
Physics , 1999, DOI: 10.1016/S0920-5632(00)00648-4
Abstract: Prospects of WIMP searches using the annual modulation signature are discussed on statistical grounds, introducing sensitivity plots for the WIMP-nucleon scalar cross section.
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