Abstract: Due to the increasing efforts on saving our natural
environment a change in the structure of energy resources can be
observed - an increasing fraction of a renewable energy sources.
In many countries traditional underground coal mining loses its
significance but there are still countries, like Poland or Germany, in
which the coal based technologies have the greatest fraction in a total
energy production. This necessitates to make an effort to limit the
costs and negative effects of underground coal mining. The longwall
complex is as essential part of the underground coal mining. The
safety and the effectiveness of the work is strongly dependent of the
diagnostic state of powered roof supports.
The building of a useful and reliable diagnostic system requires
a lot of data. As the acquisition of a data of any possible operating
conditions it is important to have a possibility to generate a demanded
artificial working characteristics. In this paper a new approach of
modelling a leg pressure in the single unit of powered roof support.
The model is a result of the analysis of a typical working cycles.
Abstract: A simple adaptive voice activity detector (VAD) is
implemented using Gabor and gammatone atomic decomposition of
speech for high Gaussian noise environments. Matching pursuit is
used for atomic decomposition, and is shown to achieve optimal
speech detection capability at high data compression rates for low
signal to noise ratios. The most active dictionary elements found by
matching pursuit are used for the signal reconstruction so that the
algorithm adapts to the individual speakers dominant time-frequency
characteristics. Speech has a high peak to average ratio enabling
matching pursuit greedy heuristic of highest inner products to isolate
high energy speech components in high noise environments. Gabor
and gammatone atoms are both investigated with identical
logarithmically spaced center frequencies, and similar bandwidths.
The algorithm performs equally well for both Gabor and gammatone
atoms with no significant statistical differences. The algorithm
achieves 70% accuracy at a 0 dB SNR, 90% accuracy at a 5 dB SNR
and 98% accuracy at a 20dB SNR using 30d B SNR as a reference
for voice activity.
Abstract: Fruit juices play important roles in human health as
being a key part of nutrition. Juice and nectar are two categories of
drinks with so many variations for consumers, regardless of age,
lifestyle and taste preferences, which they can find their favorites.
Juices contain 100% pulp when pulp content of ‘nectar’ changes
between 25%-50%. In this study, potassium (K), magnesium (Mg),
and phosphorus (P) contents in orange juice and nectar is determined
for conscious consumption. For this purpose inductively coupled
plasma optical emission spectrometry (ICP-OES) is used to find out
potassium (K), magnesium (Mg), and phosphorus (P) contents in
orange juices and nectar. Furthermore, the daily intake of elements
from orange juice and nectar that affects human health is also
investigated. From the results of experiments K, Mg and P contents
are found in orange juice as 1351; 73,25; 89,27 ppm and in orange
nectar as 986; 33,76; 51,30 respectively.
Abstract: This work studied the isomerization of 1-butene over
hydrotalcite catalyst. The experiments were conducted at various gas
hourly space velocity (GHSV), reaction temperature and feed
concentration. No catalyst deactivation was observed over the
reaction time of 16 hours. Two major reaction products were trans-2-
butene and cis-2-butene. The reaction temperature played an
important role on the reaction selectivity. At high operating
temperatures, the selectivity of trans-2-butene was higher than the
selectivity of cis-2-butene while it was opposite at lower reaction
temperature. In the range of operating condition, the maximum
conversion of 1-butene was found at 74% when T = 673 K and GHSV
= 4 m3/h/kg-cat with trans- and cis-2-butene selectivities of 54% and
46%, respectively. Finally, the kinetic parameters of the reaction
were determined.
Abstract: Kidney cancer is the most lethal urological cancer
accounting for 3% of adult malignancies. VHL, a tumor-suppressor
gene, is best known to be associated with renal cell carcinoma
(RCC). The VHL functions as negative regulator of hypoxia inducible
factors. Recent sequencing efforts have identified several novel
frequent mutations of histone modifying and chromatin remodeling
genes in ccRCC (clear cell RCC) including PBRM1 and SETD2. The
PBRM1 gene encodes the BAF180 protein, which involved in
transcriptional activation and repression of selected genes. SETD2
encodes a histone methyltransferase, which may play a role in
suppressing tumor development. In this study, RNAs of 30 paired
tumor and normal samples that were grouped according to the types
of kidney cancer and clinical characteristics of patients, including
gender and average age were examined by RT-PCR, SSCP and
sequencing techniques. VHL, PBRM1 and SETD2 expressions were
relatively down-regulated. However, statistically no significance was
found (Wilcoxon signed rank test, p>0.05). Interestingly, no mutation
was observed on the contrary of previous studies. Understanding the
molecular mechanisms involved in the pathogenesis of RCC has
aided the development of molecular-targeted drugs for kidney cancer.
Further analysis is required to identify the responsible genes rather
than VHL, PBRM1 and SETD2 in kidney cancer.
Abstract: The atmospheres in many cities along the coastal lines
in the world have been rapidly changed to coastal-industrial
atmosphere. Hence, it is vital to investigate the corrosion behavior of
steel exposed to this kind of environment. In this present study,
Electrochemical Impedance Spectrography (EIS) and film thickness
measurement were applied to monitor the corrosion behavior of
weathering steel covered with a thin layer of the electrolyte in a
wet-dry cyclic condition, simulating a coastal-industrial environment
at 25oC and 60% RH. The results indicate that in all cycles, the
corrosion rate increases during the drying process due to an increase in
anion concentration and an acceleration of oxygen diffusion enhanced
by the effect of the thinning out of the electrolyte. During the wet-dry
cyclic corrosion test, the long-term corrosion behavior of this steel
depends on the periods of exposure. Corrosion process is first
accelerated and then decelerated. The decelerating corrosion process is
contributed to the formation of the protective rust, favored by the
wet-dry cycle and the acid regeneration process during the rusting
process.
Abstract: In Hungary, the society has changed a lot for the past
25 years, and these changes could be detected in educational
situations as well. The number and the intensity of conflicts have
been increased in most fields of life, as well as at schools. Teachers
have difficulties to be able to handle school conflicts. What is more,
the new net generation, generation Z has values and behavioural
patterns different from those of the previous one, which might
generate more serious conflicts at school, especially with teachers
who were mainly socialising in a traditional teacher – student
relationship.
In Hungary, the bill CCIV of 2011 declared the foundation of
Institutes of Teacher Training in higher education institutes. One of
the tasks of the Institutes is to survey the competences and needs of
teachers working in public education and to provide further trainings
and services for them according to their needs and requirements. This
job is supported by the Social Renewal Operative Programs 4.1.2.B.
The professors of a college carried out a questionnaire and surveyed
the needs and the requirements of teachers working in the region.
Based on the results, the professors of the Institute of Teacher
Training decided to meet the requirements of teachers and to launch
short teacher further training courses in spring 2015. One of the
courses is going to focus on school conflict management through
mediation.
The aim of the pilot course is to provide conflict management
techniques for teachers and to present different mediation techniques
to them. The theoretical part of the course (5 hours) will enable
participants to understand the main points and the advantages of
mediation, while the practical part (10 hours) will involve teachers in
role plays to learn how to cope with conflict situations applying
mediation. We hope if conflicts could be reduced, it would influence
school atmosphere in a positive way and the teaching – learning
process could be more successful and effective.
Abstract: The problems arising from unbalanced data sets
generally appear in real world applications. Due to unequal class
distribution, many researchers have found that the performance of
existing classifiers tends to be biased towards the majority class. The
k-nearest neighbors’ nonparametric discriminant analysis is a method
that was proposed for classifying unbalanced classes with good
performance. In this study, the methods of discriminant analysis are
of interest in investigating misclassification error rates for classimbalanced
data of three diabetes risk groups. The purpose of this
study was to compare the classification performance between
parametric discriminant analysis and nonparametric discriminant
analysis in a three-class classification of class-imbalanced data of
diabetes risk groups. Data from a project maintaining healthy
conditions for 599 employees of a government hospital in Bangkok
were obtained for the classification problem. The employees were
divided into three diabetes risk groups: non-risk (90%), risk (5%),
and diabetic (5%). The original data including the variables of
diabetes risk group, age, gender, blood glucose, and BMI were
analyzed and bootstrapped for 50 and 100 samples, 599 observations
per sample, for additional estimation of the misclassification error
rate. Each data set was explored for the departure of multivariate
normality and the equality of covariance matrices of the three risk
groups. Both the original data and the bootstrap samples showed nonnormality
and unequal covariance matrices. The parametric linear
discriminant function, quadratic discriminant function, and the
nonparametric k-nearest neighbors’ discriminant function were
performed over 50 and 100 bootstrap samples and applied to the
original data. Searching the optimal classification rule, the choices of
prior probabilities were set up for both equal proportions (0.33: 0.33:
0.33) and unequal proportions of (0.90:0.05:0.05), (0.80: 0.10: 0.10)
and (0.70, 0.15, 0.15). The results from 50 and 100 bootstrap samples
indicated that the k-nearest neighbors approach when k=3 or k=4 and
the defined prior probabilities of non-risk: risk: diabetic as 0.90:
0.05:0.05 or 0.80:0.10:0.10 gave the smallest error rate of
misclassification. The k-nearest neighbors approach would be
suggested for classifying a three-class-imbalanced data of diabetes
risk groups.
Abstract: Prosperity of electronic equipment in photocopying
environment not only has improved work efficiency, but also has
changed indoor air quality. Considering the number of photocopying
employed, indoor air quality might be worse than in general office
environments. Determining the contribution from any type of
equipment to indoor air pollution is a complex matter. Non-methane
hydrocarbons are known to have an important role on air quality due
to their high reactivity. The presence of hazardous pollutants in
indoor air has been detected in one photocopying shop in Novi Sad,
Serbia. Air samples were collected and analyzed for five days, during
8-hr working time in three time intervals, whereas three different
sampling points were determined. Using multiple linear regression
model and software package STATISTICA 10 the concentrations of
occupational hazards and microclimates parameters were mutually
correlated. Based on the obtained multiple coefficients of
determination (0.3751, 0.2389 and 0.1975), a weak positive
correlation between the observed variables was determined. Small
values of parameter F indicated that there was no statistically
significant difference between the concentration levels of nonmethane
hydrocarbons and microclimates parameters. The results
showed that variable could be presented by the general regression
model: y = b0 + b1xi1+ b2xi2. Obtained regression equations allow to
measure the quantitative agreement between the variables and thus
obtain more accurate knowledge of their mutual relations.
Abstract: Press-hardened profiles are used e.g. for automotive
applications in order to improve light weight construction due to the
high reachable strength. The application of interior water-air spray
cooling contributes to significantly reducing the cycle time in the
production of heat-treated tubes. This paper describes a new
manufacturing method for producing press-hardened hollow profiles
by means of an additional interior cooling based on a water-air spray.
Furthermore, this paper provides the results of thorough
investigations on the properties of press-hardened tubes in
dependence of varying spray parameters.
Abstract: Microscopic simulation tool kits allow for
consideration of the two processes of railway operations and the
previous timetable production. Block occupation conflicts on both
process levels are often solved by using defined train priorities. These
conflict resolutions (dispatching decisions) generate reactionary
delays to the involved trains. The sum of reactionary delays is
commonly used to evaluate the quality of railway operations, which
describes the timetable robustness. It is either compared to an
acceptable train performance or the delays are appraised
economically by linear monetary functions. It is impossible to
adequately evaluate dispatching decisions without a well-founded
objective function. This paper presents a new approach for the
evaluation of dispatching decisions. The approach uses mode choice
models and considers the behaviour of the end-customers. These
models evaluate the reactionary delays in more detail and consider
other competing modes of transport. The new approach pursues the
coupling of a microscopic model of railway operations with the
macroscopic choice mode model. At first, it will be implemented for
railway operations process but it can also be used for timetable
production. The evaluation considers the possibility for the customer
to interchange to other transport modes. The new approach starts to
look at rail and road, but it can also be extended to air travel. The
result of mode choice models is the modal split. The reactions by the
end-customers have an impact on the revenue of the train operating
companies. Different purposes of travel have different payment
reserves and tolerances towards late running. Aside from changes to
revenues, longer journey times can also generate additional costs.
The costs are either time- or track-specific and arise from required
changes to rolling stock or train crew cycles. Only the variable values
are summarised in the contribution margin, which is the base for the
monetary evaluation of delays. The contribution margin is calculated
for different possible solutions to the same conflict. The conflict
resolution is optimised until the monetary loss becomes minimal. The
iterative process therefore determines an optimum conflict resolution
by monitoring the change to the contribution margin. Furthermore, a
monetary value of each dispatching decision can also be derived.
Abstract: High density electrical prospecting has been widely
used in groundwater investigation, civil engineering and
environmental survey. For efficient inversion, the forward modeling
routine, sensitivity calculation, and inversion algorithm must be
efficient. This paper attempts to provide a brief summary of the past
and ongoing developments of the method. It includes reviews of the
procedures used for data acquisition, processing and inversion of
electrical resistivity data based on compilation of academic literature.
In recent times there had been a significant evolution in field survey
designs and data inversion techniques for the resistivity method. In
general 2-D inversion for resistivity data is carried out using the
linearized least-square method with the local optimization technique
.Multi-electrode and multi-channel systems have made it possible to
conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve
complex geological structures that were not possible with traditional
1-D surveys. 3-D surveys play an increasingly important role in very
complex areas where 2-D models suffer from artifacts due to off-line
structures. Continued developments in computation technology, as
well as fast data inversion techniques and software, have made it
possible to use optimization techniques to obtain model parameters to
a higher accuracy. A brief discussion on the limitations of the
electrical resistivity method has also been presented.
Abstract: In order to produce lead free piezoceramics with
optimum piezoelectric and dielectric properties, KNN modified with
Li+ (as an A site dopant) and Sb5+ (as a B site dopant)
(K0.49Na0.49Li0.02) (Nb0.96Sb0.04) O3 (referred as KNLNS in this paper)
have been synthesized using solid state reaction method and
conventional sintering technique. The ceramics were sintered in the
narrow range of 1050°C-1090°C for 2-3 h to get precise information
about sintering parameters. Detailed study of dependence of
microstructural, dielectric and piezoelectric properties on sintering
conditions was then carried out. The study suggests that the volatility
of the highly hygroscopic KNN ceramics is not only sensitive to
sintering temperatures but also to sintering durations. By merely
reducing the sintering duration for a given sintering temperature we
saw an increase in the density of the samples which was supported by
the increase in dielectric constants of the ceramics. And since density
directly or indirectly affects almost all the associated properties, other
dielectric and piezoelectric properties were also enhanced as we
approached towards the most suitable sintering temperature and
duration combination. The detailed results are reported in this paper.
Abstract: In this study, we proposed two techniques to track the
maximum power point (MPPT) of a photovoltaic system. The first is
an intelligent control technique, and the second is robust used for
variable structure system. In fact the characteristics I-V and P–V of
the photovoltaic generator depends on the solar irradiance and
temperature. These climate changes cause the fluctuation of
maximum power point; a maximum power point tracking technique
(MPPT) is required to maximize the output power. For this we have
adopted a control by fuzzy logic (FLC) famous for its stability and
robustness. And a Siding Mode Control (SMC) widely used for
variable structure system. The system comprises a photovoltaic panel
(PV), a DC-DC converter, which is considered as an adaptation stage
between the PV and the load. The modelling and simulation of the
system is developed using MATLAB/Simulink. SMC technique
provides a good tracking speed in fast changing irradiation and when
the irradiation changes slowly or it is constant the panel power of
FLC technique presents a much smoother signal with less
fluctuations.
Abstract: Evolutionary optimization methods such as genetic
algorithms have been used extensively for the construction site layout
problem. More recently, ant colony optimization algorithms, which
are evolutionary methods based on the foraging behavior of ants,
have been successfully applied to benchmark combinatorial
optimization problems. This paper proposes a formulation of the site
layout problem in terms of a sequencing problem that is suitable for
solution using an ant colony optimization algorithm.
In the construction industry, site layout is a very important
planning problem. The objective of site layout is to position
temporary facilities both geographically and at the correct time such
that the construction work can be performed satisfactorily with
minimal costs and improved safety and working environment. During
the last decade, evolutionary methods such as genetic algorithms
have been used extensively for the construction site layout problem.
This paper proposes an ant colony optimization model for
construction site layout. A simple case study for a highway project is
utilized to illustrate the application of the model.
Abstract: This study investigated the behavior of improved soft soils through the vibro replacement technique by considering their settlements and consolidation rates and the applicability of this technique in various types of soils and settlement and bearing capacity calculations.
Abstract: Hypersonic flows around spatial vehicles during their reentry phase in planetary atmospheres are characterized by intense aerothermodynamics phenomena. The aim of this work is to analyze high temperature flows around an axisymmetric blunt body taking into account chemical and vibrational non-equilibrium for air mixture species and the no slip condition at the wall. For this purpose, the Navier-Stokes equations system is resolved by the finite volume methodology to determine the flow parameters around the axisymmetric blunt body especially at the stagnation point and in the boundary layer along the wall of the blunt body. The code allows the capture of shock wave before a blunt body placed in hypersonic free stream. The numerical technique uses the Flux Vector Splitting method of Van Leer. CFL coefficient and mesh size level are selected to ensure the numerical convergence.
Abstract: We investigated the structure and electronic properties
of the compound Mg1-xBixO with varying concentrations of 0, ¼, ½,
and ¾ x bismuth in the the cesium chloride (CsCl), zinc-blende
(ZnS), nickel arsenide (NiAs) NaCl (rock-salt) and WZ (wurtzite)
phases. We calculated. The calculations were performed using the
first-principles pseudo-potential method within the framework of spin
density functional theory (DFT).
Abstract: This paper presents the development of a robot car
that can track the motion of an object by detecting its color through
an Android device. The employed computer vision algorithm uses the
OpenCV library, which is embedded into an Android application of a
smartphone, for manipulating the captured image of the object. The
captured image of the object is subjected to color conversion and is
transformed to a binary image for further processing after color
filtering. The desired object is clearly determined after removing
pixel noise by applying image morphology operations and contour
definition. Finally, the area and the center of the object are
determined so that object’s motion to be tracked. The smartphone
application has been placed on a robot car and transmits by Bluetooth
to an Arduino assembly the motion directives so that to follow
objects of a specified color. The experimental evaluation of the
proposed algorithm shows reliable color detection and smooth
tracking characteristics.
Abstract: This paper adopts a two-stage data envelopment
analysis to explore the impacts of financial development and bank
operating scale on bank efficiencies. The sample comprises
unbalanced panel data of 32 Taiwanese listed domestic commercial
banks over the period 1998 to 2013. Empirical results show that pure
technical efficiency is positively related to financial development,
whereas the effect of financial development on scale efficiency is
insignificant. Enlargement of bank operating scale improves bank
efficiencies, but the efficiency gains are decreased gradually when the
scale increases. Increases in capital adequacy ratio and market power
of loans lead into a growth of bank efficiencies.