Abstract: In this study acoustic emission (AE) signals obtained during deformation and fracture of two types of ferrite-martensite dual phase steels (DPS) specimens have been analyzed in frequency domain. For this reason two low carbon steels with various amounts of carbon were chosen, and intercritically heat treated. In the introduced method, identifying the mechanisms of failure in the various phases of DPS is done. For this aim, AE monitoring has been used during tensile test of several DPS with various volume fraction of the martensite (VM) and attempted to relate the AE signals and failure mechanisms in these steels. Different signals, which referred to 2-3 micro-mechanisms of failure due to amount of carbon and also VM have been seen. By Fast Fourier Transformation (FFT) of signals in distinct locations, an excellent relationship between peak frequencies in these areas and micro-mechanisms of failure were seen. The results were verified by microscopic observations (SEM).
Abstract: A novel three-phase active power filter (APF) circuit with photovoltaic (PV) system to improve the quality of service and to reduce the capacity of energy storage capacitor is presented. The energy balance concept and sampling technique were used to simplify the calculation algorithm for the required utility source current and to control the voltage of the energy storage capacitor. The feasibility was verified by using the Pspice simulations and experiments. When the APF mode was used during non-operational period, not only the utilization rate, power factor and power quality could be improved, but also the capacity of energy storage capacitor could sparing. As the results, the advantages of the APF circuit are simplicity of control circuits, low cost, and good transient response.
Abstract: Virtual engineering technology has undergone rapid progress in recent years and is being adopted increasingly by manufacturing companies of many engineering disciplines. There is an increasing demand from industry for qualified virtual engineers. The qualified virtual engineers should have the ability of applying engineering principles and mechanical design methods within the commercial software package environment. It is a challenge to the engineering education in universities which traditionally tends to lack the integration of knowledge and skills required for solving real world problems. In this paper, a case study shows some recent development of a MSc Mechanical Engineering course at Department of Engineering and Technology in MMU, and in particular, two units Simulation of Mechanical Systems(SMS) and Computer Aided Fatigue Analysis(CAFA) that emphasize virtual engineering education and promote integration of knowledge acquisition, skill training and industrial application.
Abstract: In this paper, we propose a selective mutation method
for improving the performances of genetic algorithms. In selective
mutation, individuals are first ranked and then additionally mutated
one bit in a part of their strings which is selected corresponding to
their ranks. This selective mutation helps genetic algorithms to fast
approach the global optimum and to quickly escape local optima.
This results in increasing the performances of genetic algorithms.
We measured the effects of selective mutation with four function
optimization problems. It was found from extensive experiments that
the selective mutation can significantly enhance the performances of
genetic algorithms.
Abstract: In this paper we study different similarity based approaches for the development of QSAR model devoted to the prediction of activity of antiobesity drugs. Classical similarity approaches are compared regarding to dissimilarity models based on the consideration of the calculation of Euclidean distances between the nonisomorphic fragments extracted in the matching process. Combining the classical similarity and dissimilarity approaches into a new similarity measure, the Approximate Similarity was also studied, and better results were obtained. The application of the proposed method to the development of quantitative structure-activity relationships (QSAR) has provided reliable tools for predicting of inhibitory activity of drugs. Acceptable results were obtained for the models presented here.
Abstract: Pregnancy is considered a special period in a woman’s life. There are myths about pregnancy that describe gender predictions, dietary beliefs, pregnancy signs, and risk of magic or witchcraft. Majority of these myths is in connection with the early childcare. In traditional societies midwives and experienced women practice and teach these myths to young mothers. Mother who feel special and vulnerable, at the same time feel secure in following these socially transmitted myths. Rural Punjab, a province of Pakistan has a culture rich with beliefs and myths. Myths about pregnancy are significant in rural culture and pregnancy care is seen as mother and childcare. This paper presents my research reflections that I did as a part of my Ph.D studies about early childcare beliefs and rituals practiced in rural Punjab, Pakistan.
Abstract: Thanks to VR technology advanced, there are many
researches had used VR technology to develop a training system.
Using VR characteristics can simulate many kinds of situations to
reach our training-s goal. However, a good training system not only
considers real simulation but also considers learner-s learning
motivation. So, there are many researches started to conduct game-s
features into VR training system. We typically called this is a serious
game. It is using game-s features to engage learner-s learning
motivation. However, VR or Serious game has another important
advantage. That is simulating feature. Using this feature can create
any kinds of pressured environments. Because in the real
environment may happen any emergent situations. So, increasing the
trainees- pressure is more important when they are training. Most
pervious researches are investigated serious game-s applications and
learning performance. Seldom researches investigated how to
increase the learner-s mental workload when they are training. So, in
our study, we will introduce a real case study and create two types
training environments. Comparing the learner-s mental workload
between VR training and serious game.
Abstract: Nosocomial (i.e., hospital-acquired) infections
(NI) is a major cause of morbidity and mortality in hospitals. NI
rate is higher in intensive care units (ICU) than in the general
ward due to patients with severe symptoms, poor immunity,
and accepted many invasive therapies. Contact behaviors
between health caregivers and patients is one of the infect
factors. It is difficult to obtain complete contact records by
traditional method of retrospective analysis of medical records.
This paper establishes a contact history inferential model
(CHIM) intended to extend the use of Proximity Sensing of
rapid frequency identification (RFID) technology to
transferring all proximity events between health caregivers and
patients into clinical events (close-in events, contact events and
invasive events).The results of the study indicated that the
CHIM can infer proximity care activities into close-in events
and contact events.
The infection control team could redesign and build optimal
workflow in the ICU according to the patient-specific contact
history which provided by our automatic tracing system.
Abstract: Wikis are promoted as collaborative writing tools that
allow students to transform a text into a collective document by
information sharing and group reflection. However, despite the
promising collaborative capabilities of wikis, their pedagogical value
regarding collaborative writing is still questionable. Wiki alone
cannot make collaborative writing happen, and students do not
automatically become more active, participate, and collaborate with
others when they use wikis. To foster collaborative writing and active
involvement in wiki development there is a need for a systematic
approach to wikis. Themain goal of this paper is to propose and
evaluate a co-writing approach to the development of wikis, along
with the study of three wiki applications to report on pedagogical
implications of collaborative writing in higher education.
Abstract: The issue of leadership has been investigated from
several perspectives; however, very less from ethical perspective.
With the growing number of corporate scandals and unethical roles
played by business leaders in several parts of the world, the need to
examine leadership from ethical perspective cannot be over
emphasized. The importance of leadership credibility has been
discussed in the authentic model of leadership. Authentic leaders
display high degree of integrity, have deep sense of purpose, and
committed to their core values. As a result they promote a more
trusting relationship in their work groups that translates into several
positive outcomes. The present study examined how authentic
leadership contribute to subordinates- trust in leadership and how this
trust, in turn, predicts subordinates- work engagement. A sample of
395 employees was randomly selected from several local banks
operating in Malaysia. Standardized tools such as ALQ, OTI, and
EEQ were employed. Results indicated that authentic leadership
promoted subordinates- trust in leader, and contributed to work
engagement. Also, interpersonal trust predicted employees- work
engagement as well as mediated the relationship between this style of
leadership and employees- work engagement.
Abstract: A conventional image posterization method
occasionally fails to preserve the shape and color of objects due to the
uneffective color reduction. This paper proposes a new image
posterizartion method by using modified color quantization for
preserving the shape and color of objects and color contrast
enhancement for improving lightness contrast and saturation.
Experiment results show that our proposed method can provide
visually more satisfactory posterization result than that of the
conventional method.
Abstract: In a bid to improve turbine entry temperature for maximizing the thermal efficiency of the HP stage gas turbine blade, an attempt is made in this paper to compare the performance of helicoidal ducted blade cooling with turbulator of different geometric proportion. It is found from analysis that there is significant improvement in cooling characteristics for turbine blade with turbulator geometry having larger e/D ratio. Also it is found from analysis, performance is vastly improved for greater thickness of turbulator geometry.
Abstract: In this paper application of artificial intelligence for
baby and children caring is studied. Then a new idea for injury
prevention and safety announcement is presented by using digital
image processing. The paper presents the structure of the proposed
system. The system determines the possibility of the dangers for
children and babies in yards, gardens and swimming pools or etc. In
the presented idea, multi camera System is used and receiver videos
are processed to find the hazardous areas then the entrance of
children and babies in the determined hazardous areas are analyzed.
In this condition the system does the programmed action capture,
produce alarm or tone or send message.
Abstract: An experimental study is realized in order to verify the
Mini Heat Pipe (MHP) concept for cooling high power dissipation
electronic components and determines the potential advantages of
constructing mini channels as an integrated part of a flat heat pipe. A
Flat Mini Heat Pipe (FMHP) prototype including a capillary structure
composed of parallel rectangular microchannels is manufactured and
a filling apparatus is developed in order to charge the FMHP. The
heat transfer improvement obtained by comparing the heat pipe
thermal resistance to the heat conduction thermal resistance of a
copper plate having the same dimensions as the tested FMHP is
demonstrated for different heat input flux rates. Moreover, the heat
transfer in the evaporator and condenser sections are analyzed, and
heat transfer laws are proposed. In the theoretical part of this work, a
detailed mathematical model of a FMHP with axial microchannels is
developed in which the fluid flow is considered along with the heat
and mass transfer processes during evaporation and condensation.
The model is based on the equations for the mass, momentum and
energy conservation, which are written for the evaporator, adiabatic,
and condenser zones. The model, which permits to simulate several
shapes of microchannels, can predict the maximum heat transfer
capacity of FMHP, the optimal fluid mass, and the flow and thermal
parameters along the FMHP. The comparison between experimental
and model results shows the good ability of the numerical model to
predict the axial temperature distribution along the FMHP.
Abstract: The fabrication of porous NiTi shape memory alloys (SMAs) from elemental powder compacts was conducted by selfpropagating high temperature synthesis (SHS). Effects of the preheating temperature and the chamber pressure on the combustion characteristics as well as the final morphology and the composition of products were studied. The samples with porosity between 56.4 and 59.0% under preheating temperature in the range of 200-300°C and Ar-gas chamber pressure of 138 and 201 kPa were obtained. The pore structures were found to be dissimilar only in the samples processed with different preheating temperature. The major phase in the porous product is NiTi with small amounts of secondary phases, NiTi2 and Ni4Ti3. The preheating temperature and the chamber pressure have very little effect on the phase constituent. While the combustion temperature of the sample was notably increased by increasing the preheating temperature, they were slightly changed by varying the chamber pressure.
Abstract: Study of the vibration cylindrical shells made of
a functionally gradient material (FGM) composed of stainless
steel and nickel is important. Material properties are graded in
the thickness direction of the shell according to volume
fraction power law distribution. The objective is to study the
natural frequencies, the influence of constituent volume
fractions and the effects of boundary conditions on the natural
frequencies of the FG cylindrical shell. The study is carried
out using third order shear deformation shell theory. The
governing equations of motion of FG cylindrical shells are
derived based on shear deformation theory. Results are
presented on the frequency characteristics, influence of
constituent volume fractions and the effects of clampedclamped
boundary conditions.
Abstract: In this paper an extensive verification of the extraction
method (published earlier) that consistently accounts for self-heating
and Early effect to accurately extract both base and thermal resistance
of bipolar junction transistors is presented. The method verification is
demonstrated on advanced RF SiGe HBTs were the extracted results
for the thermal resistance are compared with those from another
published method that ignores the effect of Early effect on internal
base-emitter voltage and the extracted results of the base resistance
are compared with those determined from noise measurements. A
self-consistency of our method in the extracted base resistance and
thermal resistance using compact model simulation results is also
carried out in order to study the level of accuracy of the method.
Abstract: Regarding previous research studies it was concluded
that thin-walled fiber-cement composites are able to conduct electric
current under specific conditions. This property is ensured by using
of various kinds of carbon materials. Though carbon fibers are less
conductive than metal fibers, composites with carbon fibers were
evaluated as better current conductors than the composites with metal
fibers. The level of electric conductivity is monitored by the means of
impedance measurement of designed samples. These composites
could be used for a range of applications such as heating of
trafficable surfaces or shielding of electro-magnetic fields.
The aim of the present research was to design an element with the
ability to monitor internal processes in building structures and
prevent them from collapsing. As a typical element for laboratory
testing there was chosen a concrete column, which was repeatedly
subjected to load by simple pressure with continual monitoring of
changes in electrical properties.
Abstract: In this paper, based on the work in [1], we further give
a general model for acquiring knowledge, which first focuses on the
research of how and when things involved in problems are made
then describes the goals, the energy and the time to give an optimum
model to decide how many related things are supposed to be involved
in. Finally, we acquire knowledge from this model in which there are
the attributes, actions and connections of the things involved at the
time when they are born and the time in their life. This model not
only improves AI theories, but also surely brings the effectiveness
and accuracy for AI system because systems are given more
knowledge when reasoning or computing is used to bring about
results.
Abstract: Greenhouse gases (GHG) emissions impose major
threat to global warming potential (GWP). Unfortunately
manufacturing sector is one of the major sources that contribute
towards the rapid increase in greenhouse gases (GHG) emissions. In
manufacturing sector electric power consumption is the major driver
that influences CO2 emission. Titanium alloys are widely utilized in
aerospace, automotive and petrochemical sectors because of their
high strength to weight ratio and corrosion resistance. Titanium
alloys are termed as difficult to cut materials because of their poor
machinability rating. The present study analyzes energy consumption
during cutting with reference to material removal rate (MRR).
Surface roughness was also measured in order to optimize energy
consumption.