Abstract: Utilizing echoic intension and distribution from different organs and local details of human body, ultrasonic image can catch important medical pathological changes, which unfortunately may be affected by ultrasonic speckle noise. A feature preserving ultrasonic image denoising and edge enhancement scheme is put forth, which includes two terms: anisotropic diffusion and edge enhancement, controlled by the optimum smoothing time. In this scheme, the anisotropic diffusion is governed by the local coordinate transformation and the first and the second order normal derivatives of the image, while the edge enhancement is done by the hyperbolic tangent function. Experiments on real ultrasonic images indicate effective preservation of edges, local details and ultrasonic echoic bright strips on denoising by our scheme.
Abstract: An accurate prediction of the minimum fluidization
velocity is a crucial hydrodynamic aspect of the design of fluidized
bed reactors. Common approaches for the prediction of the minimum
fluidization velocities of binary-solid fluidized beds are first
discussed here. The data of our own careful experimental
investigation involving a binary-solid pair fluidized with water is
presented. The effect of the relative composition of the two solid
species comprising the fluidized bed on the bed void fraction at the
incipient fluidization condition is reported and its influence on the
minimum fluidization velocity is discussed. In this connection, the
capability of packing models to predict the bed void fraction is also
examined.
Abstract: The objective of this project is to study the corrosion
behaviour and hardness based on the presence of martensite in dual
phase steel. This study was conducted on six samples of dual phase
steel which have different percentage of martensite. A total of 9
specimens were prepared by intercritical annealing process to study
the effect of temperature to the formation of martensite. The low
carbon steels specimens were heated for 25 minutes in a specified
temperature ranging from 7250C to 8250C followed by rapid cooling
in water. The measurement of corrosion rate was done by using
extrapolation tafel method, while potentiostat was used to control and
measured the current produced. This measurement is performed
through a system named CMS105. The result shows that a specimen
with higher percentage of martensite is likely to corrode faster.
Hardness test for each specimen was conducted to compare its
hardness with low carbon steel. The results obtained indicate that the
specimen hardness is proportional to the amount of martensite in dual
phase steel.
Abstract: According to the increasing utilization in power system, the transmission lines and power plants often operate in stability boundary and system probably lose its stable condition by over loading or occurring disturbance. According to the reasons that are mentioned, the prediction and recognition of voltage instability in power system has particular importance and it makes the network security stronger.This paper, by considering of power system contingencies based on the effects of them on Mega Watt Margin (MWM) and maximum loading point is focused in order to analyse the static voltage stability using continuation power flow method. The study has been carried out on IEEE 14-Bus Test System using Matlab and Psat softwares and results are presented.
Abstract: In this paper we propose a new classification method for automatic sleep scoring using an artificial neural network based decision tree. It attempts to treat sleep scoring progress as a series of two-class problems and solves them with a decision tree made up of a group of neural network classifiers, each of which uses a special feature set and is aimed at only one specific sleep stage in order to maximize the classification effect. A single electroencephalogram (EEG) signal is used for our analysis rather than depending on multiple biological signals, which makes greatly simplifies the data acquisition process. Experimental results demonstrate that the average epoch by epoch agreement between the visual and the proposed method in separating 30s wakefulness+S1, REM, S2 and SWS epochs was 88.83%. This study shows that the proposed method performed well in all the four stages, and can effectively limit error propagation at the same time. It could, therefore, be an efficient method for automatic sleep scoring. Additionally, since it requires only a small volume of data it could be suited to pervasive applications.
Abstract: One of the major features of hypermedia learning is its non-linear structure, allowing learners, the opportunity of flexible navigation to accommodate their own needs. Nevertheless, such flexibility can also cause problems such as insufficient navigation and disorientation for some learners, especially those with Field Dependent cognitive styles. As a result students learning performance can be deteriorated and in turn, they can have negative attitudes with hypermedia learning systems. It was suggested that visual elements can be used to compensate dilemmas. However, it is unclear whether these visual elements improve their learning or whether problems still exist. The aim of this study is to investigate the effect of students cognitive styles and visual elements on students learning performance and attitudes in hypermedia learning environment. Cognitive Style Analysis (CSA), Learning outcome in terms of pre and post-test, practical task, and Attitude Questionnaire (AQ) were administered to a sample of 60 university students. The findings revealed that FD students preformed equally to those of FI. Also, FD students experienced more disorientation in the hypermedia learning system where they depend a lot on the visual elements for navigation and orientation purposes. Furthermore, they had more positive attitudes towards the visual elements which escape them from experiencing navigation and disorientation dilemmas. In contrast, FI students were more comfortable, did not get disturbed or did not need some of the visual elements in the hypermedia learning system.
Abstract: A numerical study on the effect of side-dump angle on
fuel droplets sizing and effective mass fraction have been
investigated in present paper. The mass of fuel vapor inside the
flammability limit is named as the effective mass fraction. In the first
step we have considered a side-dump combustor with dump angle of
0o (acrossthe cylinder) and by increasing the entrance airflow velocity
from 20 to 30, 40 and 50 (m/s) respectively, the mean diameter of
fuel droplets sizing and effective mass fraction have been studied.
After this step, we have changed the dump angle from 0o to 30o,45o
and finally 60o in direction of cylinderand also we have increased the
entrance airflow velocity from 20 up to 50 (m/s) with the amount of
growth of 10(m/s) in each step, to examine its effects on fuel droplets
sizing as well as effective mass fraction. With rise of entrance airflow
velocity, these calculations are repeated in each step too. The results
show, with growth of dump-angle the effective mass fraction has
been decreased and the mean diameter of droplets sizing has been
increased. To fulfill the calculations a modified version of KIVA-3V
code which is a transient, three-dimensional, multiphase,
multicomponent code for the analysis of chemically reacting flows
with sprays, is used.
Abstract: The present work involves measurements to examine
the effects of initial conditions on aerodynamic and acoustic
characteristics of a Jet at M=0.8 by changing the orientation of sharp
edged orifice plate. A thick plate with chamfered orifice presented divergent and convergent openings when it was flipped over. The centerline velocity was found to decay more rapidly for divergent
orifice and that was consistent with the enhanced mass entrainment
suggesting quicker spread of the jet compared with that from the convergent orifice. The mixing layer region elucidated this effect of
initial conditions at an early stage – the growth was found to be comparatively more pronounced for the divergent orifice resulting in
reduced potential core size. The acoustic measurements, carried out in the near field noise region outside the jet within potential core
length, showed the jet from the divergent orifice to be less noisy. The frequency spectra of the noise signal exhibited that in the initial
region of comparatively thin mixing layer for the convergent orifice,
the peak registered a higher SPL and a higher frequency as well. The noise spectra and the mixing layer development suggested a direct correlation between the coherent structures developing in the initial
region of the jet and the noise captured in the surrounding near field.
Abstract: The objective of this study was to determine the
effects of garlic oil (Allium sativa), turmeric powder (Curcuma longa
Linn) and Monensin on Total apparent digestibility of nutrients in
Baloochi lambs. The experiment was designed as a 4 x 4 Latin square
using 4 ruminally baloochi lambs with 4 treatments in four 28-d
periods. Treatments were control (no additive), garlic oil (0. 4 g/d),
monensin (0. 2 g/d) and turmeric powder (20 g/d). Total apparent
digestibility's (% of intake) of organic matter (OM), dry matter (DM),
crud protein (CP), ether extract(EE), non fiber carbohydrate (NFC),
acid detergent fiber (ADF) and neutral detergent fiber (NDF) in the
total tract were not influenced by addition of either additives.
Abstract: In this paper a study on the vibration of thin
cylindrical shells with ring supports and made of functionally
graded materials (FGMs) composed of stainless steel and
nickel is presented. Material properties vary along the
thickness direction of the shell according to volume fraction
power law. The cylindrical shells have ring supports which are
arbitrarily placed along the shell and impose zero lateral
deflections. The study is carried out based on third order shear
deformation shell theory (T.S.D.T). The analysis is carried out
using Hamilton-s principle. The governing equations of motion of
FGM cylindrical shells are derived based on shear deformation
theory. Results are presented on the frequency characteristics,
influence of ring support position and the influence of boundary
conditions. The present analysis is validated by comparing results
with those available in the literature.
Abstract: The national economy development affects the vehicle
ownership which ultimately increases fuel consumption. The rise of
the vehicle ownership is dominated by the increasing number of
motorcycles. This research aims to analyze and identify the
characteristics of fuel consumption, the city transportation system,
and to analyze the relationship and the effect of the city
transportation system on the fuel consumption. A multivariable
analysis is used in this study. The data analysis techniques include: a
Multivariate Multivariable Analysis by using the R software. More
than 84% of fuel on Java is consumed in metropolitan and large
cities. The city transportation system variables that strongly effect the
fuel consumption are population, public vehicles, private vehicles and
private bus. This method can be developed to control the fuel
consumption by considering the urban transport system and city
tipology. The effect can reducing subsidy on the fuel consumption,
increasing state economic.
Abstract: Recent environmental turbulence including financial
crisis, intensified competitive forces, rapid technological change and
high market turbulence have dramatically changed the current
business climate. The managers firms have to plan and decide what
the best approaches that best fit their firms in order to pursue superior
performance. This research aims to examine the influence of strategic
reasoning and top level managers- individual characteristics on the
effectiveness of organizational improvisation and firm performance.
Given the lack of studies on these relationships in the previous
literature, there is significant contribution to the body of knowledge
as well as for managerial practices. 128 responses from top
management of technology-based companies in Malaysia were used
as a sample. Three hypotheses were examined and the findings
confirm that (a) there is no relationship between intuitive reasoning
and organizational improvisation but there is a link between rational
reasoning and organizational improvisation, (b) top level managers-
individual characteristics as a whole affect organizational
improvisation; and (c) organizational improvisation positively affects
firm performance. The theoretical and managerial implications were
discussed in the conclusions.
Abstract: In this paper a new robust digital image watermarking
algorithm based on the Complex Wavelet Transform is proposed. This
technique embeds different parts of a watermark into different blocks
of an image under the complex wavelet domain. To increase security
of the method, two chaotic maps are employed, one map is used to
determine the blocks of the host image for watermark embedding,
and another map is used to encrypt the watermark image. Simulation
results are presented to demonstrate the effectiveness of the proposed
algorithm.
Abstract: In this paper we introduce an effective ECG compression algorithm based on two dimensional multiwavelet transform. Multiwavelets offer simultaneous orthogonality, symmetry and short support, which is not possible with scalar two-channel wavelet systems. These features are known to be important in signal processing. Thus multiwavelet offers the possibility of superior performance for image processing applications. The SPIHT algorithm has achieved notable success in still image coding. We suggested applying SPIHT algorithm to 2-D multiwavelet transform of2-D arranged ECG signals. Experiments on selected records of ECG from MIT-BIH arrhythmia database revealed that the proposed algorithm is significantly more efficient in comparison with previously proposed ECG compression schemes.
Abstract: Microscopic emission and fuel consumption models
have been widely recognized as an effective method to quantify real
traffic emission and energy consumption when they are applied with
microscopic traffic simulation models. This paper presents a
framework for developing the Microscopic Emission (HC, CO, NOx,
and CO2) and Fuel consumption (MEF) models for light-duty
vehicles. The variable of composite acceleration is introduced into
the MEF model with the purpose of capturing the effects of historical
accelerations interacting with current speed on emission and fuel
consumption. The MEF model is calibrated by multivariate
least-squares method for two types of light-duty vehicle using
on-board data collected in Beijing, China by a Portable Emission
Measurement System (PEMS). The instantaneous validation results
shows the MEF model performs better with lower Mean Absolute
Percentage Error (MAPE) compared to other two models. Moreover,
the aggregate validation results tells the MEF model produces
reasonable estimations compared to actual measurements with
prediction errors within 12%, 10%, 19%, and 9% for HC, CO, NOx
emissions and fuel consumption, respectively.
Abstract: The porous silicon (PS), formed from the anodization
of a p+ type substrate silicon, consists of a network organized in a
pseudo-column as structure of multiple side ramifications. Structural
micro-topology can be interpreted as the fraction of the interconnected
solid phase contributing to thermal transport. The
reduction of dimensions of silicon of each nanocristallite during the
oxidation induced a reduction in thermal conductivity. Integration of
thermal sensors in the Microsystems silicon requires an effective
insulation of the sensor element. Indeed, the low thermal conductivity
of PS consists in a very promising way in the fabrication of integrated
thermal Microsystems.In this work we are interesting in the
measurements of thermal conductivity (on the surface and in depth)
of PS by the micro-Raman spectroscopy. The thermal conductivity is
studied according to the parameters of anodization (initial doping and
current density. We also, determine porosity of samples by
spectroellipsometry.
Abstract: In this paper, we investigated the characteristic of a
clinical dataseton the feature selection and classification
measurements which deal with missing values problem.And also
posed the appropriated techniques to achieve the aim of the activity;
in this research aims to find features that have high effect to mortality
and mortality time frame. We quantify the complexity of a clinical
dataset. According to the complexity of the dataset, we proposed the
data mining processto cope their complexity; missing values, high
dimensionality, and the prediction problem by using the methods of
missing value replacement, feature selection, and classification.The
experimental results will extend to develop the prediction model for
cardiology.
Abstract: Experimental investigation of heat transfer and
friction factor characteristics of circular tube fitted with 300 right-left helical screw inserts with 100 mm spacer of different twist ratio has
been presented for laminar and turbulent flow.. The experimental data obtained were compared with those obtained from plain tube
published data. The heat transfer coefficient enhancement for 300 RL
inserts with 100 mm spacer is quite comparable with for 300 R-L
inserts. Performance evaluation analysis has been made and found
that the performance ratio increases with increasing Reynolds number
and decreasing twist ration with the maximum for the twist ratio 2.93.
Also, the performance ratio of more than one indicates that the type
of twist inserts can be used effectively for heat transfer augmentation.
Abstract: In this work, the influence of temperature on the
different parameters of solar cells based on organic semiconductors
are studied. The short circuit current Isc increases so monotonous
with temperature and then saturates to a maximum value before
decreasing at high temperatures. The open circuit voltage Vco
decreases linearly with temperature. The fill factor FF and efficiency,
which are directly related with Isc and Vco follow the variations of
the letters. The phenomena are explained by the behaviour of the
mobility which is a temperature activated process.
Abstract: Superelastic Shape Memory Alloy (SMA) is accepted
when it used as connection in steel structures. The seismic behaviour
of steel frames with SMA is being assessed in this study. Three eightstorey
steel frames with different SMA systems are suggested, the
first one of which is braced with diagonal bracing system, the second
one is braced with nee bracing system while the last one is which the
SMA is used as connection at the plastic hinge regions of beams.
Nonlinear time history analyses of steel frames with SMA subjected
to two different ground motion records have been performed using
Seismostruct software. To evaluate the efficiency of suggested
systems, the dynamic responses of the frames were compared. From
the comparison results, it can be concluded that using SMA element
is an effective way to improve the dynamic response of structures
subjected to earthquake excitations. Implementing the SMA braces
can lead to a reduction in residual roof displacement. The shape
memory alloy is effective in reducing the maximum displacement at
the frame top and it provides a large elastic deformation range. SMA
connections are very effective in dissipating energy and reducing the
total input energy of the whole frame under severe seismic ground
motion. Using of the SMA connection system is more effective in
controlling the reaction forces at the base frame than other bracing
systems. Using SMA as bracing is more effective in reducing the
displacements. The efficiency of SMA is dependant on the input
wave motions and the construction system as well.