883 research outputs found
How to Fix Coordination Lags in the Keynesian Macroeconomical Intervention?
The Keynesian macroecomic intervention often fails. This is most likely due to forecasting problems of the macroeconomy. This article present a software idea of fuzzy logic controlling unit which replaces long and tedious human intervention in macroeconomic stimulation process. The Keynesian Macroeconomic intervention now made by officials and politicians is suggested to be made by much faster and more purposeful automatic computer adjustment process. It is assumed that this kind of just in time and very fast automatic computer intervention would lead to optimimal usage of the resources in a much better way than any current human lead systems would be able to do.
The role of luck at Wall Street: What if I told you that Warren Buffet is merely lucky
Tämä pro gradu työ etsii tuurin merkitystä sijoitustoiminnassa. Työ juontaa aiheensa siitä
väittämästä, että markkina indeksien käyttäytymistä voidaan kuvailla humalaisen ihmisen
satunnaiskävelyllä. Koskaan et siis voi olla täysin varma, ottaako humalainen askeleen oikealle vai vasemmalle vai pysyykö yhtäkkisesti paikoillaan. Samalla tavalla voidaan ns. Random walk hypoteesin vallitessa katsoa, että pörssi-indeksi joko nousee, laskee tai pysyy paikoillaan ennalta arvaamattomasti kuin vedonlyönti rulettipöydän ääressä kasinolla.
Näin ollen voidaan kauaskantoisesti olettaa, että on olemassa vain tuurilla menestykseen
nousseita osakesuursijoittajia, koska sijoitustaidolla ei ole Eugene Faman tehokkaiden
markkinoiden hypoteesin vallitessa mitään käytännön merkitystä. Nobelisti Eugene Faman
mukaan fundamentalistianalyysilla tai teknisellä analyysillä ei pitäisi olla mitään käytännön
merkitystä kenellekään sijoittajalle. Random walk - hypoteesi nauttii akateemisissa piireissä
suurehkoa luottamusta.
This master's thesis looks for the meaning of luck in investment activities. The work derives its subject from the claim that the behavior of market indices can be described as that of a drunk person on a random walk. So you can never be entirely sure whether a drunk man will take a step to the right or the left or does it suddenly stay still. Thus, it can be assumed that luck can explain successful stock investors' big incomes
The role of electron-hole recombination in organic magnetoresistance
Magneto-electrical measurements were performed on diodes and bulk
heterojunction solar cells (BHSCs) to clarify the role of formation of
coulombically bound electron-hole (e-h) pairs on the magnetoresistance (MR)
response in organic thin film devices. BHSCs are suitable model systems because
they effectively quench excitons but the probability of forming e-h pairs in
them can be tuned over orders of magnitude by the choice of material and
solvent in the blend. We have systematically varied the e-h recombination
coefficients, which are directly proportional to the probability for the charge
carriers to meet in space, and found that a reduced probability of electrons
and holes meeting in space lead to disappearance of the MR. Our results clearly
show that MR is a direct consequence of e-h pair formation. We also found that
the MR line shape follows a power law-dependence of B0.5 at higher fields
A 2D Quantum Walk Simulation of Two-Particle Dynamics
Multi-dimensional quantum walks can exhibit highly non-trivial topological
structure, providing a powerful tool for simulating quantum information and
transport systems. We present a flexible implementation of a 2D optical quantum
walk on a lattice, demonstrating a scalable quantum walk on a non-trivial graph
structure. We realized a coherent quantum walk over 12 steps and 169 positions
using an optical fiber network. With our broad spectrum of quantum coins we
were able to simulate the creation of entanglement in bipartite systems with
conditioned interactions. Introducing dynamic control allowed for the
investigation of effects such as strong non-linearities or two-particle
scattering. Our results illustrate the potential of quantum walks as a route
for simulating and understanding complex quantum systems
Heavy-Light Semileptonic Decays in Staggered Chiral Perturbation Theory
We calculate the form factors for the semileptonic decays of heavy-light
pseudoscalar mesons in partially quenched staggered chiral perturbation theory
(\schpt), working to leading order in , where is the heavy quark
mass. We take the light meson in the final state to be a pseudoscalar
corresponding to the exact chiral symmetry of staggered quarks. The treatment
assumes the validity of the standard prescription for representing the
staggered ``fourth root trick'' within \schpt by insertions of factors of 1/4
for each sea quark loop. Our calculation is based on an existing partially
quenched continuum chiral perturbation theory calculation with degenerate sea
quarks by Becirevic, Prelovsek and Zupan, which we generalize to the staggered
(and non-degenerate) case. As a by-product, we obtain the continuum partially
quenched results with non-degenerate sea quarks. We analyze the effects of
non-leading chiral terms, and find a relation among the coefficients governing
the analytic valence mass dependence at this order. Our results are useful in
analyzing lattice computations of form factors and when the
light quarks are simulated with the staggered action.Comment: 53 pages, 8 figures, v2: Minor correction to the section on finite
volume effects, and typos fixed. Version to be published in Phys. Rev.
No SMAD4 hypermethylation in colorectal cancer
The chromosome region 18q21 is frequently deleted in colorectal cancers. Three candidate tumour suppressor genes, DCC, SMAD4 and SMAD2, map to this region. The SMAD4(DPC4) gene was recently identified as a candidate pancreatic cancer suppressor gene. It is also a gene for juvenile polyposis tumour predisposition syndrome. Somatic SMAD4 mutations have been detected in some colorectal carcinomas. However, the frequency of these mutations is relatively low, and whether SMAD4 plays a key role in colorectal tumorigenesis is still unclear. In addition to loss of chromosomal material and intragenic mutations there is a third mechanism, DNA methylation, which may have an important role in gene inactivation. In the present study, we examined whether promoter hypermethylation could be a mechanism for SMAD4 inactivation. In total, 42 colorectal tumours were selected for the methylation analysis and no evidence of promoter hypermethylation was found. Our result suggests that hypermethylation of the SMAD4 promoter region is not a frequent event in colorectal tumorigenesis. © 2000 Cancer Research Campaig
Experimental study of magneto-superconductor RuSr2Eu1.5Ce0.5Cu2O10: Effect of Mo doping on magnetic behavior and Tc variation
Mo doped ruthenocuprates Ru1-xMoxSr2Eu1.5Ce0.5Cu2O10 are synthesized for x =
0.0, 0.2, 0.4, 0.6, 0.8 and 1.0, and their magnetic and superconducting
properties are studied. It has been found that the magnetic transition
temperature TZFCpeak, which corresponds to the appearance of weak ferromagnetic
effect, decreases from its value of 75 K for x = 0.0 to 22 K, 25 K and 18 K,
respectively for the x = 0.2, 0.4 and 0.6 samples. Another finding is that the
magnetic susceptibility reduces at TZFCpeak by a factor of about 6, 85 and 413
for x = 0.2, 0.4, and 0.6 respectively. The samples of x = 0.8 and 1.0 are
found to have no magnetic or superconducting effects. The values of the
superconducting transition temperature are obtained from the resistivity versus
temperature data. An important result is that Tc increases by 4.5 K and 7.0 K
for x = 0.2 and 0.4 respectively, and then decreases by 17 K for x = 0.6. The
observed variation of Tc with x has been explained in terms of a theory which
combines the effects of weakening magnetic behavior and reducing carrier
concentration in a phenomenological manner. The resulting theory is found to
provide a good agreement with the observed value of Tc.Comment: 14 pages with Text + Figs. To Appear in PHYS. REV. B, Ist Jan. 2006
issu
The Ammount of Interstellar Carbon Locked in Solid Hydrogenated Amorphous Carbon
We review the literature and present new experimental data to determine the
amount of carbon likely to be locked in form of solid hydrogenated amorphous
carbon (HAC) grains. We conclude on the basis of a thorough analysis of the
intrinsic strength of the C-H stretching band at 3.4 micron that between 10 and
80 ppM H of carbon is in the form of HAC grains. We show that it is necessary
to know the level of hydrogenation (H/C) of the interstellar HAC to determine
more precisely the amount of carbon it ties up. We present optical constants,
photoluminescence spectroscopy, and IR absorption spectroscopy for a particular
HAC sample that is shown to have a 3.4 micron absorption feature that is
quantatively consistent with that observed in the diffuse interstellar medium.Comment: This paper is 14 pages long with 5 figures and will appear in the 1
December 1999 issue of Ap
Accessing the purity of a single photon by the width of the Hong-Ou-Mandel interference
We demonstrate a method to determine the spectral purity of single photons.
The technique is based on the Hong-Ou-Mandel (HOM) interference between a
single photon state and a suitably prepared coherent field. We show that the
temporal width of the HOM dip is not only related to reciprocal of the spectral
width but also to the underlying quantum coherence. Therefore, by measuring the
width of both the HOM dip and the spectrum one can directly quantify the degree
of spectral purity. The distinct advantage of our proposal is that it obviates
the need for perfect mode matching, since it does not rely on the visibility of
the interference. Our method is particularly useful for characterizing the
purity of heralded single photon states.Comment: Extended version, 16 pages, 9 figure
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