Abstract: Monitoring lightning electromagnetic pulses (sferics) and other terrestrial as well as extraterrestrial transient radiation signals is of considerable interest for practical and theoretical purposes in astro- and geophysics as well as meteorology. Managing a continuous flow of data, automation of the analysis and classification process is important. Features based on a combination of wavelet and statistical methods proved efficient for this task and serve as input into a radial basis function network that is trained to discriminate transient shapes from pulse like to wave like. We concentrate on signals in the Very Low Frequency (VLF, 3 -30 kHz) range in this paper, but the developed methods are independent of this specific choice.
Abstract: The present work deals with the calculation of
transport properties of Hg0.8Cd0.2Te (MCT) semiconductor in
degenerate case. Due to their energy-band structure, this material
becomes degenerate at moderate doping densities, which are around
1015 cm-3, so that the usual Maxwell-Boltzmann approximation is
inaccurate in the determination of transport parameters. This problem
is faced by using Fermi-Dirac (F-D) statistics, and the non-parabolic
behavior of the bands may be approximated by the Kane model. The
Monte Carlo (MC) simulation is used here to determinate transport
parameters: drift velocity, mean energy and drift mobility versus
electric field and the doped densities. The obtained results are in
good agreement with those extracted from literature.
Abstract: In this paper, a robust statistics based filter to remove salt and pepper noise in digital images is presented. The function of the algorithm is to detect the corrupted pixels first since the impulse noise only affect certain pixels in the image and the remaining pixels are uncorrupted. The corrupted pixels are replaced by an estimated value using the proposed robust statistics based filter. The proposed method perform well in removing low to medium density impulse noise with detail preservation upto a noise density of 70% compared to standard median filter, weighted median filter, recursive weighted median filter, progressive switching median filter, signal dependent rank ordered mean filter, adaptive median filter and recently proposed decision based algorithm. The visual and quantitative results show the proposed algorithm outperforms in restoring the original image with superior preservation of edges and better suppression of impulse noise
Abstract: This paper analyses the torsional efforts in gas turbine-generator shafts caused by high speed automatic reclosing of transmission lines. This issue is especially important for cases of three phase short circuit and unsuccessful reclosure of lines in the vicinity of the thermal plant. The analysis was carried out for the thermal plant TERMOPERNAMBUCO located on Northeast region of Brazil. It is shown that stress level caused by lines unsuccessful reclosing can be several times higher than terminal three-phase short circuit. Simulations were carried out with detailed shaft torsional model provided by machine manufacturer and with the “Alternative Transient Program – ATP" program [1]. Unsuccessful three phase reclosing for selected lines in the area closed to the plant indicated most critical cases. Also, reclosing first the terminal next to the gas turbine gererator will lead also to the most critical condition. Considering that the values of transient torques are very sensible to the instant of reclosing, simulation of unsuccessful reclosing with statistics ATP switch were carried out for determination of most critical transient torques for each section of the generator turbine shaft.
Abstract: The interrelationship between international stock
markets has been a key study area among the financial market
researchers for international portfolio management and risk
measurement. The characteristics of security returns and their
dynamics play a vital role in the financial market theory. This study
is an attempt to find out the dynamic linkages among the equity
market of USA and emerging markets of Pakistan and India using
daily data covering the period of January 2003–December 2009. The
study utilizes Johansen (Journal of Economic Dynamics and Control,
12, 1988) and Johansen and Juselius (Oxford Bulletin of Economics
and Statistics, 52, 1990) cointegration procedure for long run
relationship and Granger-causality tests based on Toda and
Yamamoto (Journal of Econometrics, 66, 1995) methodology.
No cointegration was found among stock markets of USA, Pakistan
and India, while Granger-causality test showed the evidence of
unidirectional causality running from New York stock exchange to
Bombay and Karachi stock exchanges.
Abstract: Complex statistical analysis of stresses in concrete
slab of the real type of rigid pavement is performed. The
computational model of the pavement is designed as a spatial (3D) model, is based on a nonlinear variant of the finite element method
that respects the structural nonlinearity, enables to model different arrangement of joints, and the entire model can be loaded by the
thermal load. Interaction of adjacent slabs in joints and contact of the slab and the subsequent layer are modeled with help of special
contact elements. Four concrete slabs separated by transverse and
longitudinal joints and the additional subgrade layers and soil to the depth of about 3m are modeled. The thickness of individual layers,
physical and mechanical properties of materials, characteristics of
joints, and the temperature of the upper and lower surface of slabs are supposed to be random variables. The modern simulation technique
Updated Latin Hypercube Sampling with 20 simulations is used for statistical analysis. As results, the estimates of basic statistics of the
principal stresses s1 and s3 in 53 points on the upper and lower surface of the slabs are obtained.
Abstract: Successful intelligence (SI) is the integrated set of the
ability needed to attain success in life, within individual-s sociocultural
context. People are successfully intelligent by recognizing
their strengths and weaknesses. They will find ways to strengthen
their weakness and maintain their strength or even improve it. SI
people can shape, select, and adapt to the environments by using
balance of higher-ordered thinking abilities including; critical,
creative, and applicative. Aims: The purposes of this study were to;
1) develop curriculum that promotes SI for nursing students, and 2)
study the effectiveness of the curriculum development. Method:
Research and Development was a method used for this study. The
design was divided into two phases; 1) the curriculum development
which composed of three steps (needs assessment, curriculum
development and curriculum field trail), and 2) the curriculum
implementation. In this phase, a pre-experimental research design
(one group pretest-posttest design) was conducted. The sample
composed of 49 sophomore nursing students of Boromarajonani
College of Nursing, Surin, Thailand who enrolled in Nursing care of
Health problem course I in 2011 academic year. Data were carefully
collected using 4 instruments; 1) Modified essay questions test
(MEQ) 2) Nursing Care Plan evaluation form 3) Group processing
observation form (α = 0.74) and 4) Satisfied evaluation form of
learning (α = 0.82). Data were analyzed using descriptive statistics
and content analysis. Results: The results revealed that the sample
had post-test average score of SI higher than pre-test average score
(mean difference was 5.03, S.D. = 2.84). Fifty seven percentages of
the sample passed the MEQ posttest at the criteria of 60 percentages.
Students demonstrated the strategies of how to develop nursing care
plan. Overall, students- satisfaction on teaching performance was at
high level (mean = 4.35, S.D. = 0.46). Conclusion: This curriculum
can promote the attribute of characteristic of SI person and was
highly required to be continued.
Abstract: The purpose of this study was to investigate effects of
modality and redundancy principles on music theory learning among
pupils of different anxiety levels. The lesson of music theory was
developed in three different modes, audio and image (AI), text with
image (TI) and audio with image and text (AIT). The independent
variables were the three modes of courseware. The moderator
variable was the anxiety level, while the dependent variable was the
post test score. The study sample consisted of 405 third-grade pupils.
Descriptive and inferential statistics were conducted to analyze the
collected data. Analyses of covariance (ANCOVA) and Post hoc
were carried out to examine the main effects as well as the
interaction effects of the independent variables on the dependent
variable. The findings of this study showed that medium anxiety
pupils performed significantly better than low and high anxiety
pupils in all the three treatment modes. The AI mode was found to
help pupils with high anxiety significantly more than the TI and AIT
modes.
Abstract: Bioinformatics and computational biology involve
the use of techniques including applied mathematics,
informatics, statistics, computer science, artificial intelligence,
chemistry, and biochemistry to solve biological problems
usually on the molecular level. Research in computational
biology often overlaps with systems biology. Major research
efforts in the field include sequence alignment, gene finding,
genome assembly, protein structure alignment, protein structure
prediction, prediction of gene expression and proteinprotein
interactions, and the modeling of evolution. Various
global rearrangements of permutations, such as reversals and
transpositions,have recently become of interest because of their
applications in computational molecular biology. A reversal is
an operation that reverses the order of a substring of a permutation.
A transposition is an operation that swaps two adjacent
substrings of a permutation. The problem of determining the
smallest number of reversals required to transform a given
permutation into the identity permutation is called sorting by
reversals. Similar problems can be defined for transpositions
and other global rearrangements. In this work we perform a
study about some genome rearrangement primitives. We show
how a genome is modelled by a permutation, introduce some
of the existing primitives and the lower and upper bounds
on them. We then provide a comparison of the introduced
primitives.
Abstract: The article investigates how 14- to 15- year-olds build informal conceptions of inferential statistics as they engage in a modelling process and build their own computer simulations with dynamic statistical software. This study proposes four primary phases of informal inferential reasoning for the students in the statistical modeling and simulation process. Findings show shifts in the conceptual structures across the four phases and point to the potential of all of these phases for fostering the development of students- robust knowledge of the logic of inference when using computer based simulations to model and investigate statistical questions.
Abstract: In this paper we present a technique to speed up
ICA based on the idea of reducing the dimensionality of the data
set preserving the quality of the results. In particular we refer to
FastICA algorithm which uses the Kurtosis as statistical property
to be maximized. By performing a particular Johnson-Lindenstrauss
like projection of the data set, we find the minimum dimensionality
reduction rate ¤ü, defined as the ratio between the size k of the reduced
space and the original one d, which guarantees a narrow confidence
interval of such estimator with high confidence level. The derived
dimensionality reduction rate depends on a system control parameter
β easily computed a priori on the basis of the observations only.
Extensive simulations have been done on different sets of real world
signals. They show that actually the dimensionality reduction is very
high, it preserves the quality of the decomposition and impressively
speeds up FastICA. On the other hand, a set of signals, on which the
estimated reduction rate is greater than 1, exhibits bad decomposition
results if reduced, thus validating the reliability of the parameter β.
We are confident that our method will lead to a better approach to
real time applications.
Abstract: The paper presents an applied study of a multivariate AR(p) process fitted to daily data from U.S. commodity futures markets with the use of Bayesian statistics. In the first part a detailed description of the methods used is given. In the second part two BVAR models are chosen one with assumption of lognormal, the second with normal distribution of prices conditioned on the parameters. For a comparison two simple benchmark models are chosen that are commonly used in todays Financial Mathematics. The article compares the quality of predictions of all the models, tries to find an adequate rate of forgetting of information and questions the validity of Efficient Market Hypothesis in the semi-strong form.
Abstract: In this work, stationary hot-wire measurements are
carried out to investigate the characteristics of a round free jet in its
potential core region (0 ≤ x/d ≤ 10). Measurements are carried out on
an incompressible round jet for a range of Reynolds numbers from
4000 to 8000, calculated based on the jet exit mean velocity and the
nozzle diameter. The effect of flow velocity on the development
characteristics of the jet in the core region is analyzed. Timeaveraged
statistics, spectra of velocity and its higher order moments
are presented and explained.
Abstract: Needs of an efficient information retrieval in recent
years in increased more then ever because of the frequent use of
digital information in our life. We see a lot of work in the area of
textual information but in multimedia information, we cannot find
much progress. In text based information, new technology of data
mining and data marts are now in working that were started from the
basic concept of database some where in 1960.
In image search and especially in image identification,
computerized system at very initial stages. Even in the area of image
search we cannot see much progress as in the case of text based
search techniques. One main reason for this is the wide spread roots
of image search where many area like artificial intelligence,
statistics, image processing, pattern recognition play their role. Even
human psychology and perception and cultural diversity also have
their share for the design of a good and efficient image recognition
and retrieval system.
A new object based search technique is presented in this paper
where object in the image are identified on the basis of their
geometrical shapes and other features like color and texture where
object-co-relation augments this search process.
To be more focused on objects identification, simple images are
selected for the work to reduce the role of segmentation in overall
process however same technique can also be applied for other
images.
Abstract: In this paper, perceptions of actors on changes in
crop productivity, quantity and quality of water, and determinants of
their perception are analyzed using descriptive statistics and ordered
logit model. Data collected from 297 Ethiopian farmers and 103
agricultural professionals from December 2009 to January 2010 are
employed. Results show that the majority of the farmers and
professionals recognized decline in water resources, reasoning
climate changes and soil erosion as some of the causes. However,
there is a variation in views on changes in productivity. The
household asset, education level, age and geographical positions are
found to affect farmers- perception on changes in crop productivity.
But, the study underlines that there is no evidence that farmers-
economic status, age, or education level affects recognition of
degradation of water resources. Thus, more focus shall be given on
providing them different coping mechanisms and alternative
resource conserving technologies than educating about the
problems.
Abstract: In recent years with the rapid development of Internet and the Web, more and more web applications have been deployed in many fields and organizations such as finance, military, and government. Together with that, hackers have found more subtle ways to attack web applications. According to international statistics, SQL Injection is one of the most popular vulnerabilities of web applications. The consequences of this type of attacks are quite dangerous, such as sensitive information could be stolen or authentication systems might be by-passed. To mitigate the situation, several techniques have been adopted. In this research, a security solution is proposed using Artificial Neural Network to protect web applications against this type of attacks. The solution has been experimented on sample datasets and has given promising result. The solution has also been developed in a prototypic web application firewall called ANNbWAF.
Abstract: Designing, implementing, and debugging concurrency
control algorithms in a real system is a complex, tedious, and errorprone
process. Further, understanding concurrency control
algorithms and distributed computations is itself a difficult task.
Visualization can help with both of these problems. Thus, we have
developed an exploratory environment in which people can prototype
and test various versions of concurrency control algorithms, study
and debug distributed computations, and view performance statistics
of distributed systems. In this paper, we describe the exploratory
environment and show how it can be used to explore concurrency
control algorithms for the interactive steering of distributed
computations.
Abstract: The aim of this article is to assess the existing
business models used by the banks operating in the CEE countries in
the time period from 2006 till 2011.
In order to obtain research results, the authors performed
qualitative analysis of the scientific literature on bank business
models, which have been grouped into clusters that consist of such
components as: 1) capital and reserves; 2) assets; 3) deposits, and 4)
loans.
In their turn, bank business models have been developed based on
the types of core activities of the banks, and have been divided into
four groups: Wholesale, Investment, Retail and Universal Banks.
Descriptive statistics have been used to analyse the models,
determining mean, minimal and maximal values of constituent
cluster components, as well as standard deviation. The analysis of
the data is based on such bank variable indices as Return on Assets
(ROA) and Return on Equity (ROE).
Abstract: In recent years, many researches to mine the exploding Web world, especially User Generated Content (UGC) such as
weblogs, for knowledge about various phenomena and events in the physical world have been done actively, and also Web services
with the Web-mined knowledge have begun to be developed for
the public. However, there are few detailed investigations on how accurately Web-mined data reflect physical-world data. It must be
problematic to idolatrously utilize the Web-mined data in public Web services without ensuring their accuracy sufficiently. Therefore,
this paper introduces the simplest Web Sensor and spatiotemporallynormalized
Web Sensor to extract spatiotemporal data about a target
phenomenon from weblogs searched by keyword(s) representing the
target phenomenon, and tries to validate the potential and reliability of the Web-sensed spatiotemporal data by four kinds of granularity
analyses of coefficient correlation with temperature, rainfall, snowfall,
and earthquake statistics per day by region of Japan Meteorological
Agency as physical-world data: spatial granularity (region-s population
density), temporal granularity (time period, e.g., per day vs. per week), representation granularity (e.g., “rain" vs. “heavy rain"), and
media granularity (weblogs vs. microblogs such as Tweets).
Abstract: Environmental statistics reveals that the pollution of
acid rain in South Korea is a serious issue. Yet the awareness of people
is low. Even after a gradual decrease of pollutant emission in Korea,
the acidity has not been reduced. There no boundaries in the
atmosphere are set and the influence of the neighboring countries such
as China is apparent. Governmental efforts among China, Japan and
Korea have been made on this issue. However, not much progress has
been observed. Along with the governmental activities, therefore, an
active monitoring of the pollution among the countries and the
promotion of environmental awareness at the civil level including
especially the middle and high schools are highly recommended. It
will be this young generation who will face damaged country as
inheritance not the current generation.