174 research outputs found
The Illogicality of Stock-Brokers: Psychological Experiments on the Effects of Prior Knowledge and Belief Biases on Logical Reasoning in Stock Trading
BACKGROUND: Explanations for the current worldwide financial crisis are primarily provided by economists and politicians. However, in the present work we focus on the psychological-cognitive factors that most likely affect the thinking of people on the economic stage and thus might also have had an effect on the progression of the crises. One of these factors might be the effect of prior beliefs on reasoning and decision-making. So far, this question has been explored only to a limited extent. METHODS: We report two experiments on logical reasoning competences of nineteen stock-brokers with long-lasting vocational experiences at the stock market. The premises of reasoning problems concerned stock trading and the experiments varied whether or not their conclusions--a proposition which is reached after considering the premises--agreed with the brokers' prior beliefs. Half of the problems had a conclusion that was highly plausible for stock-brokers while the other half had a highly implausible conclusion. RESULTS: The data show a strong belief bias. Stock-brokers were strongly biased by their prior knowledge. Lowest performance was found for inferences in which the problems caused a conflict between logical validity and the experts' belief. In these cases, the stock-brokers tended to make logically invalid inferences rather than give up their existing beliefs. CONCLUSIONS: Our findings support the thesis that cognitive factors have an effect on the decision-making on the financial market. In the present study, stock-brokers were guided more by past experience and existing beliefs than by logical thinking and rational decision-making. They had difficulties to disengage themselves from vastly anchored thinking patterns. However, we believe, that it is wrong to accuse the brokers for their "malfunctions", because such hard-wired cognitive principles are difficult to suppress even if the person is aware of them
Cu-O network-dependent core-hole screening in low-dimensional cuprate systems: a high-resolution X-ray photoemission study
We present an experimental study of the dynamics of holes in the valence bands of zero-, one-, and two-dimensional undoped model cuprates, as expressed via the screening of a Cu 2p core hole. The response depends strongly upon the dimensionality and the details of the Cu-O-Cu network geometry and clearly goes beyond the present theoretical state-of-the-art description within the three-band d-p model
Tight-binding parameters and exchange integrals of Ba_2Cu_3O_4Cl_2
Band structure calculations for Ba_2Cu_3O_4Cl_2 within the local density
approximation (LDA) are presented. The investigated compound is similar to the
antiferromagnetic parent compounds of cuprate superconductors but contains
additional Cu_B atoms in the planes. Within the LDA, metallic behavior is found
with two bands crossing the Fermi surface (FS). These bands are built mainly
from Cu 3d_{x^2-y^2} and O 2p_{x,y} orbitals, and a corresponding tight-binding
(TB) model has been parameterized. All orbitals can be subdivided in two sets
corresponding to the A- and B-subsystems, respectively, the coupling between
which is found to be small. To describe the experimentally observed
antiferromagnetic insulating state, we propose an extended Hubbard model with
the derived TB parameters and local correlation terms characteristic for
cuprates. Using the derived parameter set we calculate the exchange integrals
for the Cu_3O_4 plane. The results are in quite reasonable agreement with the
experimental values for the isostructural compound Sr_2Cu_3O_4Cl_2.Comment: 5 pages (2 tables included), 4 ps-figure
Distinct Neurocognitive Strategies for Comprehensions of Human and Artificial Intelligence
Although humans have inevitably interacted with both human and artificial intelligence in real life situations, it is unknown whether the human brain engages homologous neurocognitive strategies to cope with both forms of intelligence. To investigate this, we scanned subjects, using functional MRI, while they inferred the reasoning processes conducted by human agents or by computers. We found that the inference of reasoning processes conducted by human agents but not by computers induced increased activity in the precuneus but decreased activity in the ventral medial prefrontal cortex and enhanced functional connectivity between the two brain areas. The findings provide evidence for distinct neurocognitive strategies of taking others' perspective and inhibiting the process referenced to the self that are specific to the comprehension of human intelligence
Visual Ontology Cleaning: Cognitive Principles and Applicability
In this paper we connect two research areas, the Qualitative
Spatial Reasoning and visual reasoning on ontologies. We discuss the logical
limitations of the mereotopological approach to the visual ontology
cleaning, from the point of view of its formal support. The analysis is
based on three different spatial interpretations wich are based in turn on
three different spatial interpretations of the concepts of an ontology.Ministerio de Educación y Ciencia TIN2004-0388
Cataclysmic Variables from Sloan Digital Sky Survey V -- the search for period bouncers continues
SDSS-V is carrying out a dedicated survey for white dwarfs, single and in
binaries, and we report the analysis of the spectroscopy of cataclysmic
variables (CVs) and CV candidates obtained during the final plug plate
observations of SDSS. We identify eight new CVs, spectroscopically confirm 53
and refute eleven published CV candidates, and we report 21 new or improved
orbital periods. Combined with previously published data, the orbital period
distribution of the SDSS-V CVs does not clearly exhibit a period gap. This is
consistent with previous findings that spectroscopically identified CVs have a
larger proportion of short-period systems compared to samples identified from
photometric variability. Remarkably, despite a systematic search, we find very
few period bouncers. We estimate the space density of period bouncers to be
, i.e. they represent only a few per
cent of the total CV population. This suggests that during their final phase of
evolution, CVs either destroy the donor, e.g. via a merger, or that they become
detached and cease mass transfer.Comment: Submitted to MNRA
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