Abstract: Cements, which are intrinsically brittle materials, can
exhibit a degree of pseudo-ductility when reinforced with a sufficient
volume fraction of a fibrous phase. This class of materials, called
Engineered Cement Composites (ECC) has the potential to be used in
future tunneling applications where a level of pseudo-ductility is
required to avoid brittle failures. However uncertainties remain
regarding mechanical performance. Previous work has focused on
comparatively thin specimens; however for future civil engineering
applications, it is imperative that the behavior in tension of thicker
specimens is understood. In the present work, specimens containing
cement powder and admixtures have been manufactured following
two different processes and tested in tension. Multiple matrix
cracking has been observed during tensile testing, leading to a
“strain-hardening" behavior, confirming the possible suitability of
ECC material when used as thick sections (greater than 50mm) in
tunneling applications.
Abstract: This Paper presents a particle swarm optimization (PSO) method for determining the optimal proportional-integral-derivative (PID) controller parameters, for speed control of a linear brushless DC motor. The proposed approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency. The brushless DC motor is modelled in Simulink and the PSO algorithm is implemented in MATLAB. Comparing with Genetic Algorithm (GA) and Linear quadratic regulator (LQR) method, the proposed method was more efficient in improving the step response characteristics such as, reducing the steady-states error; rise time, settling time and maximum overshoot in speed control of a linear brushless DC motor.
Abstract: Amphawa is the most popular weekend destination for
both domestic and international tourists in Thailand. More than 112
homestays and resorts have been developed along the water
resources. This research aims to initiate appropriate environmental
management system for riverside tourist accommodations in
Amphawa by investigating current environmental characteristics.
Eighty-eight riverside tourist accommodations were survey from
specific questionnaire, GPS data were also gathered for spatial
analysis. The results revealed that the accommodations are welled
manage in regards to some environmental aspects. In order to reduce
economic costs, energy efficiency equipment is utilized. A substantial
number of tourist accommodations encouraged waste separation,
followed by transfer to local administration organization. Grease
traps also utilized in order to decrease chemical discharged, grease
and oil from canteen and restaurants on natural environment. The
most notable mitigation is to initiate environmental friendly cleansers
for tourist accommodation along the riverside in tourism destinations.
Abstract: The flow filed around a flatted-roof compound has
been investigated by means of 2D and 3D numerical simulations. A
constant wind velocity profile, based both on the maximum reference
wind speed in the building site (peak gust speed worked out for a 50-
year return period) and on the local roughness coefficient, has been
simulated in order to determine the wind-induced loads on top of the
roof. After determining the influence of the incoming wind directions
on the induced roof loads, a 2D analysis of the most severe load
condition has been performed, achieving a numerical quantification
of the expected wind-induced forces on the PV panels on top of the
roof.
Abstract: Professional development is the focus of this study. It
reports on questionnaire data that examined the perceived
effectiveness of the Train the Trainer model of technology
professional development for elementary teachers. Eighty-three
selected teachers called Information Technology Coaches received
four half-day and one after-school in-service sessions. Subsequently,
coaches shared the information and skills acquired during training
with colleagues. Results indicated that participants felt comfortable
as Information Technology Coaches and felt well prepared because
of their technological professional development. Overall, participants
perceived the Train the Trainer model to be effective. The outcomes
of this study suggest that the use of the Train the Trainer model, a
known professional development model, can be an integral and
interdependent component of the newer more comprehensive
learning community professional development model.
Abstract: In this investigation, the antibacterial effects of
ethanolic and 7:3 isopropyl –hexane mixture extracts of Zingiber
officinale were evaluated against three Gram positive bacteria, B.
cereus, S.epidermidis, S. aureus and three Gram negative bacteria, E.
coli, K.pneumonia and P.areuginosa. Utilizing paper disk diffusion
and well methods in-vitro, MIC and MBC were determined by
macrodilution. The results showed that ethanolic rhizome extract of
ginger had significantly active than Isopropyl –hexan extract. Further
work needs to be done in these extracts including fractionation to
isolate active constituents and subsequent pharmacological
evaluation.
Abstract: An effective method for the early detection of breast
cancer is the mammographic screening. One of the most important
signs of early breast cancer is the presence of microcalcifications. For
the detection of microcalcification in a mammography image, we
propose to conceive a multiagent system based on a dual irregular
pyramid.
An initial segmentation is obtained by an incremental approach;
the result represents level zero of the pyramid. The edge information
obtained by application of the Canny filter is taken into account to
affine the segmentation. The edge-agents and region-agents cooper
level by level of the pyramid by exploiting its various characteristics
to provide the segmentation process convergence.
Abstract: The wavelet transform is one of the most important
method used in signal processing. In this study, we have introduced
frequency-energy characteristics of local earthquakes using discrete
wavelet transform. Frequency-energy characteristic was analyzed
depend on difference between P and S wave arrival time and noise
within records. We have found that local earthquakes have similar
characteristics. If frequency-energy characteristics can be found
accurately, this gives us a hint to calculate P and S wave arrival time.
It can be seen that wavelet transform provides successful
approximation for this. In this study, 100 earthquakes with 500
records were analyzed approximately.
Abstract: Climate change and environmental pressures are
major international issues nowadays. It is time when governments,
businesses and consumers have to respond through more
environmentally friendly and aware practices, products and policies.
This is the prime time to develop alternative sustainable construction
materials, reduce greenhouse gas emissions, save energy, look to
renewable energy sources and recycled materials, and reduce waste.
The utilization of waste materials (slag, fly ash, glass beads, plastic
and so on) in concrete manufacturing is significant due to its
engineering, financial, environmental and ecological benefits. Thus,
utilization of waste materials in concrete production is very much
helpful to reach the goal of the sustainable construction. Therefore,
this study intends to use glass beads in concrete production.
The paper reports on the performance of 9 different concrete
mixes containing different ratios of glass crushed to 5 mm - 20 mm
maximum size and glass marble of 20 mm size as coarse aggregate.
Ordinary Portland cement type 1 and fine sand less than 0.5 mm were
used to produce standard concrete cylinders. Compressive strength
tests were carried out on concrete specimens at various ages. Test
results indicated that the mix having the balanced ratio of glass beads
and round marbles possess maximum compressive strength which is
3889 psi, as glass beads perform better in bond formation but have
lower strength, on the other hand marbles are strong in themselves
but not good in bonding. These mixes were prepared following a
specific W/C and aggregate ratio; more strength can be expected to
achieve from different W/C, aggregate ratios, adding admixtures like
strength increasing agents, ASR inhibitor agents etc.
Abstract: Desert regions around the Nile valley in Upper Egypt
contain great extent of swelling soil. Many different comment
procedures of treatment of the swelling soils for construction such as
pre-swelling, load balance OR soil replacement. One of the measure
factors which affect the level of the aggressiveness of the swelling
soil is the direction of the infiltration water directions within the
swelling soils. In this paper a physical model was installed to
measure the effect of water on the swelling soil with replacement
using fatty acid distillation residuals (FADR) mixed with sand as
thick sand-FADR mixture to prevent the water pathway arrive to the
swelling soil. Testing program have been conducted on different
artificial samples with different sand to FADR contents ratios (4%,
6%, and 9%) to get the optimum value fulfilling the impermeable
replacement. The tests show that a FADR content of 9% is sufficient
to produce impermeable replacement.
Abstract: The Marangoni convective instability in a horizontal
fluid layer with the insoluble surfactant and nondeformable free
surface is investigated. The surface tension at the free surface is
linearly dependent on the temperature and concentration gradients.
At the bottom surface, the temperature conditions of uniform
temperature and uniform heat flux are considered. By linear stability
theory, the exact analytical solutions for the steady Marangoni
convection are derived and the marginal curves are plotted. The
effects of surfactant or elasticity number, Lewis number and Biot
number on the marginal Marangoni instability are assessed. The
surfactant concentration gradients and the heat transfer mechanism at
the free surface have stabilizing effects while the Lewis number
destabilizes fluid system. The fluid system with uniform temperature
condition at the bottom boundary is more stable than the fluid layer
that is subjected to uniform heat flux at the bottom boundary.
Abstract: Asphalt surfaces are exposed to various weather
conditions and dynamic loading caused by passing trucks and
vehicles. In such situations, asphalt cement shows so different
rheological-mechanical behavior. If asphalt cement isn-t compatible
enough, asphalt layer will be damaged immediately and expensive
repairing procedures should be performed then. To overcome this
problem, researchers study on mechanical improved asphalt cement.
In this study, bentonite was used in order to modify bitumen
characteristics and the modified bitumen's characteristics were
investigated by asphalt cement tests. Then, the optimal bitumen
content in various compounds was determined and asphalt samples
with different contents of additives were prepared and tested. Results
show using this kind of additive not only has caused improvement in
bitumen mechanical properties, but also improvement in Marshall
Parameters was achieved.
Abstract: The roll center is one of the key parameters for designing a suspension. Several driving characteristics are affected significantly by the migration of the roll center during the suspension-s motion. The strut/SLA (strut/short-long-arm) suspension, which is widely used in production cars, combines the space-saving characteristics of a MacPherson strut suspension with some of the preferred handling characteristics of an SLA suspension. In this study, a front strut/SLA suspension is modeled by ADAMS/Car software. Kinematic roll analysis is then employed to investigate how the rolling characteristics change under the wheel travel and steering input. The related parameters, including the roll center height, roll camber gain, toe change, scrub radius and wheel track width change, are analyzed and discussed. It is found that the strut/SLA suspension clearly has a higher roll center than strut and SLA suspensions do. The variations in the roll center height under roll analysis are very different as the wheel travel displacement and steering angle are added. The results of the roll camber gain, scrub radius and wheel track width change are considered satisfactory. However, the toe change is too large and needs fine-tuning through a sensitivity analysis.
Abstract: Kwashiorkor is one of nutritional problem in
Indonesia, which lead to decrease immune system. This condition
causes susceptibility to infectious disease, especially tuberculosis.
Development of new tuberculosis vaccine will be an important
strategy to eliminate tuberculosis in kwashiorkor. Previous research
showed that 38-kDa Mycobacterium tuberculosis protein is one of the
potent immunogen. However, the role of oral immunization with 38-
kDa Mycobacterium tuberculosis protein to the number of
lymphocytes in the rat model of kwashiorkor is still unknown. We
used kwashiorkor rat model groups with 4% and 2% low protein diet.
Oral immunization with 38-kDa Mycobacterium tuberculosis protein
given with 2 booster every week. The lymphocytes number were
measured by flowcytometry. There was no significant difference
between the number of lymphocytes in the normal rat group and the
kwashiorkor rat groups. It may reveal the role of 38-kDa
Mycobacterium tuberculosis protein as a potent immunogen that can
increase the lymphocytes number from kwashiorkor rat model same
as normal rat.
Abstract: Classification of electroencephalogram (EEG) signals
extracted during mental tasks is a technique that is actively pursued
for Brain Computer Interfaces (BCI) designs. In this paper, we
compared the classification performances of univariateautoregressive
(AR) and multivariate autoregressive (MAR) models
for representing EEG signals that were extracted during different
mental tasks. Multilayer Perceptron (MLP) neural network (NN)
trained by the backpropagation (BP) algorithm was used to classify
these features into the different categories representing the mental
tasks. Classification performances were also compared across
different mental task combinations and 2 sets of hidden units (HU): 2
to 10 HU in steps of 2 and 20 to 100 HU in steps of 20. Five different
mental tasks from 4 subjects were used in the experimental study and
combinations of 2 different mental tasks were studied for each
subject. Three different feature extraction methods with 6th order
were used to extract features from these EEG signals: AR
coefficients computed with Burg-s algorithm (ARBG), AR
coefficients computed with stepwise least square algorithm (ARLS)
and MAR coefficients computed with stepwise least square
algorithm. The best results were obtained with 20 to 100 HU using
ARBG. It is concluded that i) it is important to choose the suitable
mental tasks for different individuals for a successful BCI design, ii)
higher HU are more suitable and iii) ARBG is the most suitable
feature extraction method.
Abstract: In this paper, we propose a new method to distinguish
between arousal and relaxation states by using multiple features
acquired from a photoplethysmogram (PPG) and support vector
machine (SVM). To induce arousal and relaxation states in subjects, 2
kinds of sound stimuli are used, and their corresponding biosignals are
obtained using the PPG sensor. Two features–pulse to pulse interval
(PPI) and pulse amplitude (PA)–are extracted from acquired PPG
data, and a nonlinear classification between arousal and relaxation is
performed using SVM.
This methodology has several advantages when compared with
previous similar studies. Firstly, we extracted 2 separate features from
PPG, i.e., PPI and PA. Secondly, in order to improve the classification
accuracy, SVM-based nonlinear classification was performed.
Thirdly, to solve classification problems caused by generalized
features of whole subjects, we defined each threshold according to
individual features.
Experimental results showed that the average classification
accuracy was 74.67%. Also, the proposed method showed the better
identification performance than the single feature based methods.
From this result, we confirmed that arousal and relaxation can be
classified using SVM and PPG features.
Abstract: This paper presents a subjective job scheduler based
on a 3-layer Backpropagation Neural Network (BPNN) and a greedy
alignment procedure in order formulates a real-life situation. The
BPNN estimates critical values of jobs based on the given subjective
criteria. The scheduler is formulated in such a way that, at each time
period, the most critical job is selected from the job queue and is
transferred into a single machine before the next periodic job arrives.
If the selected job is one of the oldest jobs in the queue and its
deadline is less than that of the arrival time of the current job, then
there is an update of the deadline of the job is assigned in order to
prevent the critical job from its elimination. The proposed
satisfiability criteria indicates that the satisfaction of the scheduler
with respect to performance of the BPNN, validity of the jobs and the
feasibility of the scheduler.
Abstract: This paper presents a multiband CPW-fed slot antenna
with L-slot bowtie tuning stub. The proposed antenna has been
designed for PCS 1900, UMTS, WLAN 802.11 a/b/g and bluetooth
applications, with a cost-effective FR4 substrate. The proposed
antenna still radiate as omni-directional in azimuth plane and
sufficient bandwidth for all above mentions. The proposed antenna
works as dual-wideband, bandwidth at low frequency band and high
frequency are about 45.49 % and 22.39 % respectively. The
experimental results of the constructed prototype are presented and
also compared with simulation results using a commercial software
tool.
Abstract: The aim of the paper work is to investigate and predict
the static performance of journal bearing in turbulent flow condition
considering micropolar lubrication. The Reynolds equation has been
modified considering turbulent micropolar lubrication and is solved
for steady state operations. The Constantinescu-s turbulence model is
adopted using the coefficients. The analysis has been done for a
parallel and inertia less flow. Load capacity and friction factor have
been evaluated for various operating parameters.
Abstract: In this paper, a direct torque control - space vector
modulation (DTC-SVM) scheme is presented for a six-phase speed
and voltage sensorless induction motor (IM) drive. The decoupled
torque and stator flux control is achieved based on IM stator flux field orientation. The rotor speed is detected by on-line estimating of
the rotor angular slip speed and stator vector flux speed. In addition, a simple method is introduced to estimate the stator resistance.
Moreover in this control scheme the voltage sensors are eliminated
and actual motor phase voltages are approximated by using PWM
inverter switching times and the dc link voltage. Finally, some simulation and experimental results are presented to verify the
effectiveness and capability of the proposed control scheme.