1,342 research outputs found
The Theory of Fuzzy Logic and its Application to Real Estate Valuation
Fuzzy logic is based on the central idea that in fuzzy sets each element in the set can assume a value from 0 to 1, not just 0 or 1, as in classic set theory. Thus, qualitative characteristics and numerically scaled measures can exhibit gradations in the extent to which they belong to the relevant sets for evaluation. This degree of membership of each element is a measure of the elementâs "belonging" to the set, and thus of the precision with which it explains the phenomenon being evaluated. Fuzzy sets can be combined to produce meaningful conclusions, and inferences can be made, given a specified fuzzy input function. The article demonstrates the application of fuzzy logic to an income-producing property, with a resulting fuzzy set output.
A Self-Organized Method for Computing the Epidemic Threshold in Computer Networks
In many cases, tainted information in a computer network can spread in a way
similar to an epidemics in the human world. On the other had, information
processing paths are often redundant, so a single infection occurrence can be
easily "reabsorbed". Randomly checking the information with a central server is
equivalent to lowering the infection probability but with a certain cost (for
instance processing time), so it is important to quickly evaluate the epidemic
threshold for each node. We present a method for getting such information
without resorting to repeated simulations. As for human epidemics, the local
information about the infection level (risk perception) can be an important
factor, and we show that our method can be applied to this case, too. Finally,
when the process to be monitored is more complex and includes "disruptive
interference", one has to use actual simulations, which however can be carried
out "in parallel" for many possible infection probabilities
Courtship as a Waiting Game
In most times and places, women on average, marry older men. We suggest a partial explanation. If the economic roles of males are more specialized than those of females, the desirability of a female as a mate may become evident at an earlier age than is the case for males. Males with good prospects will wait until their economic success is revealed before choosing a bride. Those with poor prospects try to marry young. In equilibrium, the most desirable young females choose successful older males. The less desirable young females have no better option than to marry available young males.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/101090/1/ECON075.pd
Log-Concave Probability and its Applications
In many applications,assumptions about the log-concavity of a probability distribution allow just enough special structure to yield a workable theory.This paper catalogs a series of theorems relating log-concavity and/or log-convexity of probability density functions,distribution functions,reliability functions,and their integrals. We list a large number of commonly-used probability distributions and report the log-concavity or log-convexity of their density functions and their integrals. We also discuss a variety of applications of log-concavity that have appeared in the literature.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100687/1/ECON015.pd
A population study of type II bursts in the Rapid Burster
Type II bursts are thought to arise from instabilities in the accretion flow
onto a neutron star in an X-ray binary. Despite having been known for almost 40
years, no model can yet satisfactorily account for all their properties. To
shed light on the nature of this phenomenon and provide a reference for future
theoretical work, we study the entire sample of Rossi X-ray Timing Explorer
data of type II bursts from the Rapid Burster (MXB 1730-335). We find that type
II bursts are Eddington-limited in flux, that a larger amount of energy goes in
the bursts than in the persistent emission, that type II bursts can be as short
as 0.130 s, and that the distribution of recurrence times drops abruptly below
15-18 s. We highlight the complicated feedback between type II bursts and the
NS surface thermonuclear explosions known as type I bursts, and between type II
bursts and the persistent emission. We review a number of models for type II
bursts. While no model can reproduce all the observed burst properties and
explain the source uniqueness, models involving a gating role for the magnetic
field come closest to matching the properties of our sample. The uniqueness of
the source may be explained by a special combination of magnetic field
strength, stellar spin period and alignment between the magnetic field and the
spin axis.Comment: Accepted 2015 February 12. Received 2015 February 10; in original
form 2014 December 1
Lâinnovazione nelle strategie dei piccoli e medi studi professionali per supportare lâinnovazione nelle strategie delle piccole e medie imprese
Protein losing gastroenteropathy: A disturbance of albumin metabolism
Thesis (M.D.)âBoston Universit
Deep Sequencing in Pre- and Clinical Vaccine Research
Vaccine research has experienced a quantum leap after the beginning of the genomics era. High-throughput sequencing techniques, unlimited computing resources, as well as new bioinformatic algorithms are now changing the way we perform genomic studies. Whole genome sequencing will soon become the gold standard for phylogenetic and epidemiology studies and is already shedding new light on the dynamics of bacterial evolution. We believe that deep sequencing projects, together with structural studies on vaccine candidates, will allow targeting constant epitopes and avoid vaccine failure due to antigenic variability. Systems biology, which is expected to revolutionize vaccine research and clinical studies, greatly relies on high-throughput technologies such as RNA-seq. Furthermore, genomics is a key element to develop safer vaccines, and the accuracy of deep sequencing will allow monitoring vaccine coverage after their introduction on the market
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