1,688 research outputs found
Finding Academic Experts on a MultiSensor Approach using Shannon's Entropy
Expert finding is an information retrieval task concerned with the search for
the most knowledgeable people, in some topic, with basis on documents
describing peoples activities. The task involves taking a user query as input
and returning a list of people sorted by their level of expertise regarding the
user query. This paper introduces a novel approach for combining multiple
estimators of expertise based on a multisensor data fusion framework together
with the Dempster-Shafer theory of evidence and Shannon's entropy. More
specifically, we defined three sensors which detect heterogeneous information
derived from the textual contents, from the graph structure of the citation
patterns for the community of experts, and from profile information about the
academic experts. Given the evidences collected, each sensor may define
different candidates as experts and consequently do not agree in a final
ranking decision. To deal with these conflicts, we applied the Dempster-Shafer
theory of evidence combined with Shannon's Entropy formula to fuse this
information and come up with a more accurate and reliable final ranking list.
Experiments made over two datasets of academic publications from the Computer
Science domain attest for the adequacy of the proposed approach over the
traditional state of the art approaches. We also made experiments against
representative supervised state of the art algorithms. Results revealed that
the proposed method achieved a similar performance when compared to these
supervised techniques, confirming the capabilities of the proposed framework
Interference Effects in Quantum Belief Networks
Probabilistic graphical models such as Bayesian Networks are one of the most
powerful structures known by the Computer Science community for deriving
probabilistic inferences. However, modern cognitive psychology has revealed
that human decisions could not follow the rules of classical probability
theory, because humans cannot process large amounts of data in order to make
judgements. Consequently, the inferences performed are based on limited data
coupled with several heuristics, leading to violations of the law of total
probability. This means that probabilistic graphical models based on classical
probability theory are too limited to fully simulate and explain various
aspects of human decision making.
Quantum probability theory was developed in order to accommodate the
paradoxical findings that the classical theory could not explain. Recent
findings in cognitive psychology revealed that quantum probability can fully
describe human decisions in an elegant framework. Their findings suggest that,
before taking a decision, human thoughts are seen as superposed waves that can
interfere with each other, influencing the final decision.
In this work, we propose a new Bayesian Network based on the psychological
findings of cognitive scientists. We made experiments with two very well known
Bayesian Networks from the literature. The results obtained revealed that the
quantum like Bayesian Network can affect drastically the probabilistic
inferences, specially when the levels of uncertainty of the network are very
high (no pieces of evidence observed). When the levels of uncertainty are very
low, then the proposed quantum like network collapses to its classical
counterpart
Female labor force participation and the big five
This paper investigates the relationship between personality traits and female labor force participation. While research on the role of cognitive skills for individual labor market success has a long tradition in economics, comparatively little is known about the channels through which non-cognitive skills affect individual labor market behavior. There is striking evidence that personality traits play a major role in explaining individual differences in school attendance and school performance. However, comparatively little is known about how and which personality traits effect labor supply decisions. In this paper, we relate personality traits to preference parameters using a conventional structural framework of labor force participation. This allows us to separate the direct effects of personality traits affecting the individual participation decision through different individual preferences from the indirect effects through wages. We can show that personality traits play an important role in the female labor force participation decision. The channels through which personality traits effect labor force participation are manifold and depend on the specific trait. Aggregation of traits to a single index is therefore a suboptimal strategy. --personality traits,female labor supply,wages
Application of a simple nonparametric conditional quantile function estimator in unemployment duration analysis
We consider an extension of conventional univariate Kaplan-Meier type estimators for the hazard rate and the survivor function to multivariate censored data with a censored random regressor. It is an Akritas (1994) type estimator which adapts the nonparametric conditional hazard rate estimator of Beran (1981) to more typical data situations in applied analysis. We show with simulations that the estimator has nice finite sample properties and our implementation appears to be fast. As an application we estimate nonparametric conditional quantile functions with German administrative unemployment duration data. --nonparametric estimation,censoring,unemployment duration
Simple nonparametric estimators for unemployment duration analysis
"We consider an extension of conventional univariate Kaplan-Meier type estimators for the hazard rate and the survivor function to multivariate censored data with a censored random regressor. It is an Akritas (1994) type estimator which adapts the nonparametric conditional hazard rate estimator of Beran (1981) to more typical data situations in applied analysis. We show with simulations that the estimator has nice finite sample properties and our implementation appears to be fast. As an application we estimate nonparametric conditional quantile functions with German administrative unemployment duration data." (Author's abstract, IAB-Doku) ((en)) Additional Information Appendix for the FDZ-Methodenreport No. 09/2007: Programme.zipArbeitslosigkeitsdauer, Schätzung - Methode, IAB-Beschäftigtenstichprobe
Application of a simple nonparametric conditional quantile function estimator in unemployment duration analysis
The paper analyses the potential impact of stock market developments on lending behaviour from different perspectives. First we scrutinize the impact of stock market movements on the banks? and on the borrowers? balance sheets. Subsequently we estimate aggregate credit supply and demand functions including a stock market indicator as explanatory variable. The analysis reveals no major importance of the bank balance sheet channel for the relationship between stock market volatility and corporate financing possibilities of non-financial companies. A possible impact of stock market movements on banks´ lending behaviour might be rooted in their impact on the balance sheets of corporate borrowers. The empirical results of the credit market analysis yield some confirming evidence for an impact of stock market developments. However, the results are not very stable and depend on the specification of the model and on the time period under observation. --
- âŚ