Abstract: Cole-Cole parameters of 40 post-menopausal women
are compared with their DEXA bone mineral density measurements.
Impedance characteristics of four extremities are compared; left and
right extremities are statistically same, but lower extremities are
statistically different than upper ones due to their different fat
content. The correlation of Cole-Cole impedance parameters to bone
mineral density (BMD) is observed to be higher for dominant arm.
With the post-menopausal population, ANOVA tests of the dominant
arm characteristic frequency, as a predictor for DEXA classified
osteopenic and osteoporic population around lumbar spine, is
statistically very significant. When used for total lumbar spine
osteoporosis diagnosis, the area under the Receiver Operating Curve
of the characteristic frequency is 0.830, suggesting that the Cole-Cole
plot characteristic frequency could be a useful diagnostic parameter
when integrated into standard screening methods for osteoporosis.
Moreover, the characteristic frequency can be directly measured by
monitoring frequency driven angular behavior of the dominant arm
without performing any complex calculation.
Abstract: In this study, an Artificial Neural Network (ANN)
analytical method has been developed for analyzing earthquake
performances of the Reinforced Concrete (RC) buildings. 66 RC
buildings with four to ten storeys were subjected to performance
analysis according to the parameters which are the existing material,
loading and geometrical characteristics of the buildings. The selected
parameters have been thought to be effective on the performance of
RC buildings. In the performance analyses stage of the study, level of
performance possible to be shown by these buildings in case of an
earthquake was determined on the basis of the 4-grade performance
levels specified in Turkish Earthquake Code-2007 (TEC-2007). After
obtaining the 4-grade performance level, selected 23 parameters of
each building have been matched with the performance level. In this
stage, ANN-based fast evaluation algorithm mentioned above made
an economic and rapid evaluation of four to ten storey RC buildings.
According to the study, the prediction accuracy of ANN has been
found about 74%.
Abstract: The current paper presents the results of a conducted
case study. During the past few years the number of children
diagnosed with Learning Difficulties has drastically augmented and
especially the cases of ADHD (Attention Deficit Hyperactivity
Disorder). One of the core characteristics of ADHD is a deficit in
working memory functions. The review of the literature indicates a
plethora of educational software that aim at training and enhancing
the working memory. Nevertheless, in the current paper, the
possibility of using for the same purpose free, online games will be
explored. Another issue of interest is the potential effect of the
working memory training to the core symptoms of ADHD. In order
to explore the abovementioned research questions, three digital tests
are employed, all of which are developed on the E-slate platform by
the author, in order to check the levels of ADHD’s symptoms and to
be used as diagnostic tools, both in the beginning and in the end of
the case study. The tools used during the main intervention of the
research are free online games for the training of working memory.
The research and the data analysis focus on the following axes: a) the
presence and the possible change in two of the core symptoms of
ADHD, attention and impulsivity and b) a possible change in the
general cognitive abilities of the individual. The case study was
conducted with the participation of a thirteen year-old, female
student, diagnosed with ADHD, during after-school hours. The
results of the study indicate positive changes both in the levels of
attention and impulsivity. Therefore, we conclude that the training of
working memory through the use of free, online games has a positive
impact on the characteristics of ADHD. Finally, concerning the
second research question, the change in general cognitive abilities, no
significant changes were noted.
Abstract: The goal of the modern education system is to prepare
students to be able to adapt to ever-changing life situations. They
must be able to acquire required knowledge independently; apply
such knowledge in practice to solve various problems by using
modern technologies; think critically and creatively; competently use
information; be communicative, work in a team; and develop their
own moral values, intellect and cultural awareness. As a result, the
status of education significantly increases; new requirements to its
quality have been formed. In recent years the competency-based
approach in education has become of significant interest. This
approach is a strengthening of applied and practical characteristics of
a school education and leads to the forming of the key students’
competencies which define their success in future life. In this article,
the authors’ attention focuses on a range of key competencies,
educational, informational and communicative and on the possibility
to develop such competencies via STEM education. This research
shows the change in students’ attitude towards scientific disciplines
such as mathematics, general science, technology and engineering as
a result of STEM education. Two staged analyzed questionnaires
completed by students of forms II to IV in the republic of Trinidad
and Tobago allowed the authors to categorize students between two
levels that represent students’ attitude to various disciplines. The
significance of differences between selected levels was confirmed
with the use of Pearson’s chi-squared test. In summary, the analysis
of obtained data makes it possible to conclude that STEM education
has a great potential for development of core students’ competencies
and encourage the development of positive student attitude towards
the above mentioned above scientific disciplines.
Abstract: Twin steel plates-concrete composite shear walls are
composed of a pair of steel plate layers and a concrete layer
sandwiched between them, which have the characteristics of both
reinforced concrete shear walls and steel plate shear walls. Twin steel
plates-composite shear walls contain very high ultimsate bearing
capacity and ductility, which have great potential to be applied in the
super high-rise buildings and special structures. In this paper, we
analyzed the basic characteristics and stress mechanism of the twin
steel plates-composite shear walls. Specifically, we analyzed the
effects of the steel plate thickness, wall thickness and concrete
strength on the bearing capacity of the twin steel plates-composite
shear walls. The analysis results indicate that: (1) the initial shear
stiffness and ultimate shear-carrying capacity is not significantly
affected by the thickness of concrete wall but by the class of concrete,
(2) both factors significantly impact the shear distribution of the
shear walls in ultimate shear-carrying capacity. The technique of twin
steel plates-composite shear walls has been successfully applied in
the construction of an 88-meter Huge Statue of Buddha located in
Hunan Province, China. The analysis results and engineering
experiences showed that the twin steel plates-composite shear walls
have great potential for future research and applications.
Abstract: This research paper presents the current practices of
teacher professional development, perceived as beneficial by teachers
themselves, in a private secondary school in Brunei Darussalam. This
is part of the findings of a larger qualitative study on teacher
empowerment, using ethnographic methods for data collection, i.e.
participant observation, interviews and document analysis. The field
work was carried out over a period of six months in 2013. An
analysis of the field data revealed multiple pathways of teacher
professional development existing in the school. The results indicate
that school leaders, the teacher community in the school, students,
and the teachers themselves were the agents in a school that
facilitated teacher empowerment. Besides contributing to the
knowledge base on teacher professional development, the results of
this study provide directions for educational policy makers in their
efforts to enhance professional development in secondary schools of
similar characteristics. For school leaders and the teacher community,
these findings offer guidelines for maximizing the opportunities for
these professional development practices, by strengthening
collegiality and by using the existing structures optimally for the
benefit of all concerned.
Abstract: Expansive soils are often encountered in many parts
of the world, especially in arid and semi-arid fields. Such kind of
soils, generally including active clay minerals in low water content,
enlarge in volume by absorbing the water through the surface and
cause a great harm to the light structures such as channel coating,
roads and airports. The expansive soils were encountered on the path
of Apa-Hotamış conveyance channel belonging to the State
Hydraulic Works in the region of Konya. In the research done in this
area, it is predicted that the soil has a swollen nature and the soil
should be filled with proper granular equipments by digging the
ground to 50-60 cm. In this study, for purpose of helping the other
research to be done in the same area, it is thought that instead of
replacing swollen soil with the granular soil, by stabilizing it with
polypropylene fiber and using it its original place decreases effect of
swelling percent, in this way the cost will be decreased. Therefore,
laboratory tests were conducted to study the effects of polypropylene
fiber on swelling characteristics of expansive soil. Test results
indicated that inclusion of fiber reduced swell percent of expansive
soil. As the fiber content increased, the unconfined compressive
strength was increased. Finally, it can be said that stabilization of
expansive soils with polypropylene fiber is an effective method.
Abstract: These days, the industrial trend is moving away from heavy and bulky passive components to power converter systems that use more and more semiconductor elements. Also, it is difficult to connect the traditional converters to the high and medium voltage. For these reasons, a new family of multilevel inverters has appeared as a solution for working with higher voltage levels. Different modulation topologies like Sinusoidal Pulse Width Modulation (SPWM), Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) are available for multilevel inverters. In this work, different hybrid modulation techniques which are combination of fundamental frequency modulation and multilevel sinusoidal-modulation are compared. The main characteristic of these modulations are reduction of switching losses with good harmonic performance and balanced power loss dissipation among the device. The proposed hybrid modulation schemes are developed and simulated in Matlab/Simulink for cascaded H-bridge inverter. The results validate the applicability of the proposed schemes for cascaded multilevel inverter.
Abstract: Useful lifetime evaluation of chevron rubber spring
was very important in design procedure to assure the safety and
reliability. It is, therefore, necessary to establish a suitable criterion
for the replacement period of chevron rubber spring. In this study, we
performed characteristic analysis and useful lifetime prediction of
chevron rubber spring. Rubber material coefficient was obtained by
curve fittings of uniaxial tension equibiaxial tension and pure shear
test. Computer simulation was executed to predict and evaluate the
load capacity and stiffness for chevron rubber spring. In order to
useful lifetime prediction of rubber material, we carried out the
compression set with heat aging test in an oven at the temperature
ranging from 50°C to 100°C during a period 180 days. By using the
Arrhenius plot, several useful lifetime prediction equations for rubber
material was proposed.
Abstract: The aim of this study is to investigate the relationship
between expectation, satisfaction and loyalty of South Korean
tourists visiting Turkey. In the research, a questionnaire was used as a
data collecting tool. The questionnaires are filled by South Korean
tourists coming to Turkey through package tours and individual. The
survey was conducted in 2014 in Nevsehir (Cappadocia Region) and
Istanbul. Tourist guides and agency staff have helped the
implementation of surveys. The survey questions are composed of 4
parts, which are “demographic characteristics of tourists”, “travel
behavior characteristics”, “perception of expectations on destination
attributes” and “perception of destination loyalty”. 5-point Likert
type scale including 28 destination attributes was used to measure the
expectations of South Korean tourists coming to Turkey. Questions
were directed to the tourists to measure the destination loyalty. The
questions relating to destination loyalty are “Talking about Turkey to
others”, “Recommendation Turkey to others” and “Tourists’
intentions to revisit Turkey”. The basic hypothesis of the research is
that there is a statistically significant relationship among
expectations, satisfactions and destination loyalty of South Korean
tourists coming to Turkey. The results indicated that the expectation
had a significant effect on overall satisfaction. In addition it was seen
that between overall satisfaction of tourists and destination loyalty
had a significant relationship. Based on findings, some suggestions
for tour operators and travel agencies were made.
Abstract: The global demand for long-tailed macaques for
medical experimentation has continued to increase. Fulfillment of
Indonesian export demands has been mostly from natural habitats,
based on a harvesting quota. This quota has been determined
according to the total catch for a given year, and not based on
consideration of any demographic parameters or physical
environmental factors with regard to the animal; hence threatening
the sustainability of the various populations. It is therefore necessary
to formulate a method for calculating a sustainable harvesting quota,
based on population parameters in natural habitats. Considering the
possibility of variations in habitat characteristics and population
parameters, a time series observation of demographic and
physical/biotic parameters, in various habitats, was performed on 13
groups of long-tailed macaques, distributed throughout the West
Java, Lampung and Yogyakarta areas of Indonesia. These provinces
were selected for comparison of the influence of human/tourism
activities. Data on population parameters that was collected included
data on life expectancy according to age class, numbers of
individuals by sex and age class, and ‘ratio of infants to reproductive
females’. The estimation of population growth was based on a
population dynamic growth model: the Leslie matrix. The harvesting
quota was calculated as being the difference between the actual
population size and the MVP (minimum viable population) for each
sex and age class. Observation indicated that there were variations within group size
(24–106 individuals), gender (sex) ratio (1:1 to 1:1.3), life expectancy
value (0.30 to 0.93), and ‘ratio of infants to reproductive females’
(0.23 to 1.56). Results of subsequent calculations showed that
sustainable harvesting quotas for each studied group of long-tailed
macaques, ranged from 29 to 110 individuals. An estimation model
of the MVP for each age class was formulated as Log Y = 0.315 +
0.884 Log Ni (number of individual on ith age class). This study also
found that life expectancy for the juvenile age class was affected by
the humidity under tree stands, and dietary plants’ density at sapling,
pole and tree stages (equation: Y=2.296 – 1.535 RH + 0.002 Kpcg –
0.002 Ktg – 0.001 Kphn, R2 = 89.6% with a significance value of
0.001). By contrast, for the sub-adult-adult age class, life expectancy
was significantly affected by slope (equation: Y=0.377 = 0.012 Kml,
R2 = 50.4%, with significance level of 0.007). The infant-toreproductive-
female ratio was affected by humidity under tree stands,
and dietary plant density at sapling and pole stages (equation: Y = -
1.432 + 2.172 RH – 0.004 Kpcg + 0.003 Ktg, R2 = 82.0% with
significance level of 0.001). This research confirmed the importance
of population parameters in determining the minimum viable
population, and that MVP varied according to habitat characteristics
(especially food availability). It would be difficult therefore, to
formulate a general mathematical equation model for determining a
harvesting quota for the species as a whole.
Abstract: Sewer deposits have been identified as a major cause
of dysfunctions in combined sewer systems regarding sewer
management, which induces different negative consequents resulting
in poor hydraulic conveyance, environmental damages as well as
worker’s health. In order to overcome the problematics of
sedimentation, flushing has been considered as the most operative
and cost-effective way to minimize the sediments impacts and
prevent such challenges. Flushing, by prompting turbulent wave
effects, can modify the bed form depending on the hydraulic
properties and geometrical characteristics of the conduit. So far, the
dynamics of the bed-load during high-flow events in combined sewer
systems as a complex environment is not well understood, mostly due
to lack of measuring devices capable to work in the “hostile” in
combined sewer system correctly. In this regards, a one-episode
flushing issue from an opening gate valve with weir function was
carried out in a trunk sewer in Paris to understand its cleansing
efficiency on the sediments (thickness: 0-30 cm). During more than
1h of flushing within 5 m distance in downstream of this flushing
device, a maximum flowrate and a maximum level of water have
been recorded at 5 m in downstream of the gate as 4.1 m3/s and 2.1
m respectively. This paper is aimed to evaluate the efficiency of this
type of gate for around 1.1 km (from the point -50 m to +1050 m in
downstream from the gate) by (i) determining bed grain-size
distribution and sediments evolution through the sewer channel, as
well as their organic matter content, and (ii) identifying sections that
exhibit more changes in their texture after the flush. For the first one,
two series of sampling were taken from the sewer length and then
analyzed in laboratory, one before flushing and second after, at same
points among the sewer channel. Hence, a non-intrusive sampling
instrument has undertaken to extract the sediments smaller than the
fine gravels. The comparison between sediments texture after the
flush operation and the initial state, revealed the most modified zones
by the flush effect, regarding the sewer invert slope and hydraulic
parameters in the zone up to 400 m from the gate. At this distance,
despite the increase of sediment grain-size rages, D50 (median grainsize)
varies between 0.6 mm and 1.1 mm compared to 0.8 mm and 10
mm before and after flushing, respectively. Overall, regarding the
sewer channel invert slope, results indicate that grains smaller than
sands (< 2 mm) are more transported to downstream along about 400
m from the gate: in average 69% before against 38% after the flush
with more dispersion of grain-sizes distributions. Furthermore, high
effect of the channel bed irregularities on the bed material evolution
has been observed after the flush.
Abstract: The objective of this paper is to evaluate the effects of
soil-structure interaction (SSI) on the modal characteristics and on
the dynamic response of current structures. The objective is on the
overall behaviour of a real structure of five storeys reinforced
concrete (R/C) building typically encountered in Algeria. Sensitivity
studies are undertaken in order to study the effects of frequency
content of the input motion, frequency of the soil-structure system,
rigidity and depth of the soil layer on the dynamic response of such
structures. This investigation indicated that the rigidity of the soil
layer is the predominant factor in soil-structure interaction and its
increases would definitely reduce the deformation in the R/C
structure. On the other hand, increasing the period of the underlying
soil will cause an increase in the lateral displacements at story levels
and create irregularity in the distribution of story shears. Possible
resonance between the frequency content of the input motion and soil
could also play an important role in increasing the structural
response.
Abstract: Conductivity properties of DNA molecule is
investigated in a simple, but chemically specific approach that is
intimately related to the Su-Schrieffer-Heeger (SSH) model. This
model is a tight-binding linear nanoscale chain. We have tried to
study the electrical current flowing in DNA and investigated the
characteristic I-V diagram. As a result, It is shown that there are the
(quasi-) ohmic areas in I-V diagram. On the other hand, the regions
with a negative differential resistance (NDR) are detectable in
diagram.
Abstract: Speaker Identification (SI) is the task of establishing
identity of an individual based on his/her voice characteristics. The SI
task is typically achieved by two-stage signal processing: training and
testing. The training process calculates speaker specific feature
parameters from the speech and generates speaker models
accordingly. In the testing phase, speech samples from unknown
speakers are compared with the models and classified. Even though
performance of speaker identification systems has improved due to
recent advances in speech processing techniques, there is still need of
improvement. In this paper, a Closed-Set Tex-Independent Speaker
Identification System (CISI) based on a Multiple Classifier System
(MCS) is proposed, using Mel Frequency Cepstrum Coefficient
(MFCC) as feature extraction and suitable combination of vector
quantization (VQ) and Gaussian Mixture Model (GMM) together
with Expectation Maximization algorithm (EM) for speaker
modeling. The use of Voice Activity Detector (VAD) with a hybrid
approach based on Short Time Energy (STE) and Statistical
Modeling of Background Noise in the pre-processing step of the
feature extraction yields a better and more robust automatic speaker
identification system. Also investigation of Linde-Buzo-Gray (LBG)
clustering algorithm for initialization of GMM, for estimating the
underlying parameters, in the EM step improved the convergence rate
and systems performance. It also uses relative index as confidence
measures in case of contradiction in identification process by GMM
and VQ as well. Simulation results carried out on voxforge.org
speech database using MATLAB highlight the efficacy of the
proposed method compared to earlier work.
Abstract: Steel slag is a by-product of the steel industry and can
be used potentially as aggregate in the asphalt mixture. This study
evaluates the use of Steel Slag Aggregates (SSA) as a substitute for
natural aggregates in the production of hot mix asphalt (HMA) for
road construction. Based on intensive laboratory testing program, the
characteristic properties of SSA were assessed to determine its
suitability to be used in HMA. Four different percentages (0, 50, 75,
and 100%) of SSA were used, and the proposed mix designs for
HMA were conducted in accordance with Marshall mix design. The
experiment results revealed that the addition of SSA has a significant
improvement on the properties of HMA. An increase in density and
stability and a reduction in flow and air voids values were clearly
observed in specimens prepared with 100% SSA. It is concluded that
the steel slag can be considered reasonable alternative source of
aggregate for concrete asphalt mixture production.
Abstract: In this paper, we report the development of the device
for diagnostics of cardiovascular system state and associated
automated workstation for large-scale medical measurement data
collection and analysis. It was shown that optimal design for the
monitoring device is wristband as it represents engineering trade-off
between accuracy and usability. Monitoring device is based on the
infrared reflective photoplethysmographic sensor, which allows
collecting multiple physiological parameters, such as heart rate and
pulsing wave characteristics. Developed device uses BLE interface
for medical and supplementary data transmission to the coupled
mobile phone, which processes it and send it to the doctor's
automated workstation. Results of this experimental model
approbation confirmed the applicability of the proposed approach.
Abstract: Standard Gibbs energy of formation ΔGfor(298.15) of
lanthanide-iron double oxides of garnet-type crystal structure
R3Fe5O12 - RIG (R – are rare earth ions) from initial oxides are
evaluated. The calculation is based on the data of standard entropies
S298.15 and standard enthalpies ΔH298.15 of formation of compounds
which are involved in the process of garnets synthesis. Gibbs energy
of formation is presented as temperature function ΔGfor(T) for the
range 300-1600K. The necessary starting thermodynamic data were
obtained from calorimetric study of heat capacity – temperature
functions and by using the semi-empirical method for calculation of
ΔH298.15 of formation. Thermodynamic functions for standard
temperature – enthalpy, entropy and Gibbs energy - are
recommended as reference data for technological evaluations.
Through the structural series of rare earth-iron garnets the correlation
between thermodynamic properties and characteristics of lanthanide
ions are elucidated.
Abstract: Discursive practices enacted by educators in
kindergarten create a blueprint for how the educational trajectories of
students with disabilities are constructed. This two-year ethnographic
case study critically examines educators’ relationships with students
considered to present challenging behaviors in one kindergarten
classroom located in a predominantly White middle class school
district in the Northeast of the United States. Focusing on the
language and practices used by one special education teacher and
three teaching assistants, this paper analyzes how teacher responses
to students’ behaviors constructs and positions students over one year
of kindergarten education. Using a critical discourse analysis it shows
that educators understand students’ behaviors as deficit and needing
consequences. This study highlights how educators’ responses reflect
students' individual characteristics including family background,
socioeconomics and ability status. This paper offers in depth analysis
of two students’ stories, which evidenced that the language used by
educators amplifies the social positioning of students within the
classroom and creates a foundation for who they are constructed to
be. Through exploring routine language and practices, this paper
demonstrates that educators outlined a blueprint of kindergartners,
which positioned students as learners in ways that became the ground
for either a limited or a promising educational pathway for them.
Abstract: The present study applies the inverse method and
three-dimensional CFD commercial software in conjunction with the
experimental temperature data to investigate the heat transfer and fluid
flow characteristics of the plate-fin heat sink in a rectangular closed
enclosure. The inverse method with the finite difference method and
the experimental temperature data is applied to determine the
approximate heat transfer coefficient. Later, based on the obtained
results, the zero-equation turbulence model is used to obtain the heat
transfer and fluid flow characteristics between two fins. T0 validate
the accuracy of the results obtained, the comparison of the heat transfer
coefficient is made. The obtained temperature at selected
measurement locations of the fin is also compared with experimental
data. The effect of the height of the rectangular enclosure on the
obtained results is discussed.