3,633 research outputs found
Test of the purchasing power parity hypothesis by using panel structural break test for transition economies
This paper is aim to test the validity of the purchasing power parity hypothesis by analyzing the transition economies such as Bulgaria, Czech Republic, Hungary, Poland, Romania. For this purpose, the minimum LM unit root test with one structural break is applied to real exchange rate data.PPP, MADF, LM test.
On linear H∞ equalization of communication channels
As an alternative to existing techniques and algorithms, we investigate the merit of the H∞ approach to the linear equalization of communication channels. We first give the formulation of all causal H∞ equalizers using the results of and then look at the finite delay case. We compare the risk-sensitive H∞ equalizer with the MMSE equalizer with respect to both the average and the worst-case BER performances and illustrate the improvement due to the use of the H∞ equalizer
Single-event kinetic modeling of the hydrocracking of hydrogenated vacuum gas oil
The primary objective of the research project was to further develop a computer program
modeling the hydrocracking of partially hydrogenated vacuum gas oil (HVGO), and to use the
model to compare the theoretical product distribution to experimental data describing the product
distribution of an industrial pilot reactor. The hydrocracking of HVGO on acid zeolites is
effectively modeled utilizing a single-event kinetic approach developed by Froment and
coworkers. The hydrocracking of HVGO can be described in terms of the fundamental reaction
steps involving carbenium ions. Some 45 single-event rate parameters are used to dictate the rate
of each single-event in the reaction network. The composition of the partially hydrogenated
feed stock is detailed up to C33. Each component and lump is considered in terms of the
elementary steps to generate a network of continuity equations and single-event rate parameters.
A reactor model comprising this kinetic model can be used to simulate the isothermal and nonisothermal
hydrocracking of a HVGO feed stock. The results are represented in terms of the
yields of 241 lumps and components in the gas phase and 241 components and lumps in the
liquid phase. The predicted yields of various commercial oil fractions and particular components
are then compared to experimental data from an industrial pilot reactor to verify the accuracy of
the model and the single-event rate parameters
Perceived parenting style, depression and anxiety levels in a Turkish late-adolescent population
AbstractThe socio-economic status of family has an effect on the mental health. Individuals from “low-S.E.S” families are more prone to depression and anxiety disorders. This study observes the relation between perceived parenting style and depressive moods in Turkish adolescents from 3 different S.E.S levels. A total of 150 subjects representing 3 different S.E.S levels were given the “My Memories of Upbringing”, Children Depression Inventory, and State-Trait Anxiety Inventory tests. Results indicate that school guidance and psychological counseling services should develop policies addressing parents for giving insight about their parenting style which in turn might result in preventive mental healthcare
A Bayesian Perspective for Determinant Minimization Based Robust Structured Matrix Factorizatio
We introduce a Bayesian perspective for the structured matrix factorization
problem. The proposed framework provides a probabilistic interpretation for
existing geometric methods based on determinant minimization. We model input
data vectors as linear transformations of latent vectors drawn from a
distribution uniform over a particular domain reflecting structural
assumptions, such as the probability simplex in Nonnegative Matrix
Factorization and polytopes in Polytopic Matrix Factorization. We represent the
rows of the linear transformation matrix as vectors generated independently
from a normal distribution whose covariance matrix is inverse Wishart
distributed. We show that the corresponding maximum a posteriori estimation
problem boils down to the robust determinant minimization approach for
structured matrix factorization, providing insights about parameter selections
and potential algorithmic extensions
On robust signal reconstruction in noisy filter banks
We study the design of synthesis filters in noisy filter bank systems using an H∞ estimation point of view. The H∞ approach is most promising in situations where the statistical properties of the disturbances (arising from quantization, compression, etc.) in each subband of the filter bank is unknown, or is too difficult to model and analyze. For the important special case of unitary analysis polyphase matrices we obtain an explicit expression for the minimum achievable disturbance attenuation. For arbitrary analysis polyphase matrices, standard state-space H∞ techniques can be employed to obtain numerical solutions. When the synthesis filters are restricted to being FIR, as is often the case in practice, the design can be cast as a finite-dimensional semi-definite program. In this case, we can effectively exploit the inherent non-uniqueness of the H∞ solution to optimize for an additional criteria. By optimizing for average performance in addition to the H∞ criteria, we obtain mixed H^2/H∞ optimal FIR synthesis filters. Alternatively, if the additional criteria is concerned with penalizing occasional occurrence of large values of reconstruction errors more than frequent occurrence of small to moderate ones, we obtain risk-sensitive FIR synthesis filters. Numerical examples and comparisons with existing methods are also included
H^∞ equalization of communication channels
As an alternative to existing techniques and algorithms, we investigate the merit of the H-infinity approach to the equalization of communication channels. We first look at causal H-infinity equalization problem and then look at the improvement due to finite delay. By introducing the risk sensitive property, we compare the average performance of the central H-infinity equalizer with the MMSE equalizer in equalizing minimum phase channels
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