Abstract: Simplified coupled engine block-crankshaft models
based on beam theory provide an efficient substitute to engine
simulation in the design process. These models require accurate
definition of the main bearing stiffness. In this paper, an investigation
of this stiffness is presented. The clearance effect is studied using a
smooth bearing model. It is manifested for low shaft displacement.
The hydrodynamic assessment model shows that the oil film has no
stiffness for low loads and it is infinitely rigid for important loads.
The deformation stiffness is determined using a suitable finite
elements model based on real CADs. As a result, a main bearing
behaviour law is proposed. This behaviour law takes into account the
clearance, the hydrodynamic sustention and the deformation stiffness.
It ensures properly the transition from the configuration low rigidity
to the configuration high rigidity.
Abstract: The recent drive for use of performance-based methodologies in design and assessment of structures in seismic areas has significantly increased the demand for the development of reliable nonlinear inelastic static pushover analysis tools. As a result, the adaptive pushover methods have been developed during the last decade, which unlike their conventional pushover counterparts, feature the ability to account for the effect that higher modes of vibration and progressive stiffness degradation might have on the distribution of seismic storey forces. Even in advanced pushover methods, little attention has been paid to the Unsymmetric structures. This study evaluates the seismic demands for three dimensional Unsymmetric-Plan buildings determined by the Displacement-based Adaptive Pushover (DAP) analysis, which has been introduced by Antoniou and Pinho [2004]. The capability of DAP procedure in capturing the torsional effects due to the irregularities of the structures, is investigated by comparing its estimates to the exact results, obtained from Incremental Dynamic Analysis (IDA). Also the capability of the procedure in prediction the seismic behaviour of the structure is discussed.
Abstract: Renewable natural fibres such as oil palm, flax, and
pineapple leaf can be utilized to obtain new high performance
polymer materials. The reuse of waste natural fibres as reinforcement
for polymer is a sustainable option to the environment. However, due
to its high hydroxyl content of cellulose, natural fibres are
susceptible to absorb water that affects the composite mechanical
properties adversely. Research found that Nano materials such as
Nano Silica Carbide (n-SiC) and Nano Clay can be added into the
polymer composite to overcome this problem by enhancing its
mechanical properties in wet condition. The addition of Nano
material improves the tensile and wear properties, flexural stressstrain
behaviour, fracture toughness, and fracture strength of polymer
natural composites in wet and dry conditions.
Abstract: Two different superhydrophobic surfaces were
elaborated and their oil repellency behavior was evaluated using
several liquid with different surface tension. A silicone rubber/SiO2
nanocomposite coated (A) on aluminum substrate by “spin-coating"
and the sample B was an anodized aluminum surface covered by
Teflon-like coating. A high static contact angle about ∼162° was
measured for two prepared surfaces on which the water droplet rolloff.
Scanning electron microscopy (SEM) showed the presence of
micro/nanostructures for both sample A and B similar to that of lotus
leaf.
However the sample A presented significantly different behaviour
of wettability against the low surface tension liquid. Sample A has
been wetted totally by oil (dodecan) droplet while sample B showed
oleophobic behaviour. Oleophobic property of Teflon like coating
can be contributed to the presence of CF2 and CF3 functional group
which was shown by XPS analysis.
Abstract: With respect to the dissipation of energy through
plastic deformation of joints of prefabricated wall units, the paper
points out the principal importance of efficient reinforcement of the
prefabricated system at its joints. The method, quality and amount of
reinforcement are essential for reaching the necessary degree of joint
ductility. The paper presents partial results of experimental research
of vertical joints of prefabricated units exposed to monotonously
rising loading and repetitive shear force and formulates a conclusion
that the limit state of the structure as a whole is preceded by the
disintegration of joints, or that the structure tends to pass from
linearly elastic behaviour to non-linearly elastic to plastic behaviour
by exceeding the proportional elastic limit in joints.Experimental
verification on a model of a 7-storey prefabricated structure revealed
weak points in its load-bearing systems, mainly at places of critical
points around openings situated in close proximity to vertical joints
of mutually perpendicularly oriented walls.
Abstract: The aim of this paper is to propose a mathematical
model to determine invariant sets, set covering, orbits and, in
particular, attractors in the set of tourism variables. Analysis was
carried out based on a pre-designed algorithm and applying our
interpretation of chaos theory developed in the context of General
Systems Theory. This article sets out the causal relationships
associated with tourist flows in order to enable the formulation of
appropriate strategies. Our results can be applied to numerous cases.
For example, in the analysis of tourist flows, these findings can be
used to determine whether the behaviour of certain groups affects that
of other groups and to analyse tourist behaviour in terms of the most
relevant variables. Unlike statistical analyses that merely provide
information on current data, our method uses orbit analysis to
forecast, if attractors are found, the behaviour of tourist variables in
the immediate future.
Abstract: Historic religious buildings located in seismic areas
have developed different failure mechanisms. Simulation of failure
modes is done with computer programs through a nonlinear dynamic
analysis or simplified using the method of failure blocks. Currently
there are simulation methodologies of failure modes based on the
failure rigid blocks method only for Roman Catholic churches type.
Due to differences of shape in plan, elevation and construction
systems between Orthodox churches and Catholic churches, for the
first time there were initiated researches in the development of this
simulation methodology for Orthodox churches. In this article are
presented the first results from the researches. The theoretical results
were compared with real failure modes recorded at an Orthodox
church from Banat region, severely damaged by earthquakes in
1991. Simulated seismic response, using a computer program based
on finite element method was confirmed by cracks after earthquakes.
The consolidation of the church was made according to these
theoretical results, realizing a rigid floor connecting all the failure
blocks.
Abstract: The aim of the current study is to develop a numerical
tool that is capable of achieving an optimum shape and design of
hyperbolic cooling towers based on coupling a non-linear finite
element model developed in-house and a genetic algorithm
optimization technique. The objective function is set to be the
minimum weight of the tower. The geometric modeling of the tower
is represented by means of B-spline curves. The finite element
method is applied to model the elastic buckling behaviour of a tower
subjected to wind pressure and dead load. The study is divided into
two main parts. The first part investigates the optimum shape of the
tower corresponding to minimum weight assuming constant
thickness. The study is extended in the second part by introducing the
shell thickness as one of the design variables in order to achieve an
optimum shape and design. Design, functionality and practicality
constraints are applied.
Abstract: Traditional higher-education classrooms allow lecturers to observe students- behaviours and responses to a particular pedagogy during learning in a way that can influence changes to the pedagogical approach. Within current e-learning systems it is difficult to perform continuous analysis of the cohort-s behavioural tendency, making real-time pedagogical decisions difficult. This paper presents a Virtual Learning Process Environment (VLPE) based on the Business Process Management (BPM) conceptual framework. Within the VLPE, course designers can model various education pedagogies in the form of learning process workflows using an intuitive flow diagram interface. These diagrams are used to visually track the learning progresses of a cohort of students. This helps assess the effectiveness of the chosen pedagogy, providing the information required to improve course design. A case scenario of a cohort of students is presented and quantitative statistical analysis of their learning process performance is gathered and displayed in realtime using dashboards.
Abstract: This paper describes a three-dimensional thermal
model of the current path included in the low voltage power circuit
breakers. The model can be used to analyse the thermal behaviour of
the current path during both steady-state and transient conditions.
The current path lengthwise temperature distribution and timecurrent
characteristic of the terminal connections of the power circuit
breaker have been obtained. The influence of the electric current and
voltage drop on main electric contact of the circuit breaker has been
investigated. To validate the three-dimensional thermal model, some
experimental tests have been done. There is a good correlation
between experimental and simulation results.
Abstract: Only recently have water ethics received focused interest in the international water community. Because water is metabolically basic to life, an ethical dimension persists in every decision related to water. Water ethics at once express human society-s approach to water and act as guidelines for behaviour. Ideas around water are often implicit and embedded as assumptions. They can be entrenched in behaviour and difficult to contest because they are difficult to “see". By explicitly revealing the ethical ideas underlying water-related decisions, human society-s relationship with water, and with natural systems of which water is part, can be contested and shifted or be accepted with conscious intention by human society. In recent decades, improved understanding of water-s importance for ecosystem functioning and ecological services for human survival is moving us beyond this growth-driven, supplyfocused management paradigm. Environmental ethics challenge this paradigm by extending the ethical sphere to the environment and thus water or water Resources management per se. An ethical approach is a legitimate, important, and often ignored approach to effect change in environmental decision making. This qualitative research explores principles of water ethics and examines the underlying ethical precepts of selected water policy examples. The constructed water ethic principles act as a set of criteria against which a policy comparison can be established. This study shows that water Resources management is a progressive issue by embracing full public participation and a new planning model, and knowledgegeneration initiatives.
Abstract: Rational Emotive Behaviour Therapy is the first
cognitive behavior therapy which was introduced by Albert Ellis.
This is a systematic and structured psychotherapy which is effective
in treating various psychological problems. A patient, 25 years old
male, experienced intense fear and situational panic attack to return
to his faculty and to face his class-mates after a long absence (2
years). This social anxiety disorder was a major factor that impeded
the progress of his study. He was treated with the use of behavioural
technique such as relaxation breathing technique and cognitive
techniques such as imagery, cognitive restructuring, rationalization
technique and systematic desensitization. The patient reported
positive improvement in the anxiety disorder, able to progress well in
studies and lead a better quality of life as a student.
Abstract: The SOM has several beneficial features which make
it a useful method for data mining. One of the most important
features is the ability to preserve the topology in the projection.
There are several measures that can be used to quantify the goodness
of the map in order to obtain the optimal projection, including the
average quantization error and many topological errors. Many
researches have studied how the topology preservation should be
measured. One option consists of using the topographic error which
considers the ratio of data vectors for which the first and second best
BMUs are not adjacent. In this work we present a study of the
behaviour of the topographic error in different kinds of maps. We
have found that this error devaluates the rectangular maps and we
have studied the reasons why this happens. Finally, we suggest a new
topological error to improve the deficiency of the topographic error.
Abstract: Earthquakes produce some of the most violent loading
situations that a structure can be subjected to and if a structure fails
under these loads then inevitably human life is put at risk. One of the
most common methods by which a structure fails under seismic
loading is at the connection of structural elements. The research
presented in this paper investigates the interlock systems as a novel
method for building structures. The main objective of this
experimental study wasto determine the dynamic characteristics and
the seismic behaviour of the proposed structures compared to
conventional structural systemsduring seismic motions. Results of
this study indicate that the interlock mechanism of the panels
influences the behaviour of lateral load-resisting systems of the
structures during earthquakes, contributing to better structural
flexibility and easier maintenance.
Abstract: Evolvable hardware (EHW) refers to a selfreconfiguration
hardware design, where the configuration is under
the control of an evolutionary algorithm (EA). A lot of research has
been done in this area several different EA have been introduced.
Every time a specific EA is chosen for solving a particular problem,
all its components, such as population size, initialization, selection
mechanism, mutation rate, and genetic operators, should be selected
in order to achieve the best results. In the last three decade a lot of
research has been carried out in order to identify the best parameters
for the EA-s components for different “test-problems". However
different researchers propose different solutions. In this paper the
behaviour of mutation rate on (1+λ) evolution strategy (ES) for
designing logic circuits, which has not been done before, has been
deeply analyzed. The mutation rate for an EHW system modifies
values of the logic cell inputs, the cell type (for example from AND
to NOR) and the circuit output. The behaviour of the mutation has
been analyzed based on the number of generations, genotype
redundancy and number of logic gates used for the evolved circuits.
The experimental results found provide the behaviour of the mutation
rate to be used during evolution for the design and optimization of
logic circuits. The researches on the best mutation rate during the last
40 years are also summarized.
Abstract: The transient analysis of a queuing system with fixed-size batch Poisson arrivals and a single server with exponential service times is presented. The focus of the paper is on the use of the functions that arise in the analysis of the transient behaviour of the queuing system. These functions are shown to be a generalization of the modified Bessel functions of the first kind, with the batch size B as the generalizing parameter. Results for the case of single-packet arrivals are obtained first. The similarities between the two families of functions are then used to obtain results for the general case of batch arrival queue with a batch size larger than one.
Abstract: Due to their high power-to-weight ratio and low cost,
pneumatic actuators are attractive for robotics and automation
applications; however, achieving fast and accurate control of their
position have been known as a complex control problem. A
methodology for obtaining high position accuracy with a linear
pneumatic actuator is presented. During experimentation with a
number of PID classical control approaches over many operations of
the pneumatic system, the need for frequent manual re-tuning of the
controller could not be eliminated. The reason for this problem is
thermal and energy losses inside the cylinder body due to the
complex friction forces developed by the piston displacements.
Although PD controllers performed very well over short periods, it
was necessary in our research project to introduce some form of
automatic gain-scheduling to achieve good long-term performance.
We chose a fuzzy logic system to do this, which proved to be an
easily designed and robust approach. Since the PD approach showed
very good behaviour in terms of position accuracy and settling time,
it was incorporated into a modified form of the 1st order Tagaki-
Sugeno fuzzy method to build an overall controller. This fuzzy gainscheduler
uses an input variable which automatically changes the PD
gain values of the controller according to the frequency of repeated
system operations. Performance of the new controller was
significantly improved and the need for manual re-tuning was
eliminated without a decrease in performance. The performance of
the controller operating with the above method is going to be tested
through a high-speed web network (GRID) for research purposes.
Abstract: This paper discusses the development of a qualitative
simulator (abbreviated QRiOM) for predicting the behaviour of
organic chemical reactions. The simulation technique is based on the
qualitative process theory (QPT) ontology. The modelling constructs
of QPT embody notions of causality which can be used to explain the
behaviour of a chemical system. The major theme of this work is
that, in a qualitative simulation environment, students are able to
articulate his/her knowledge through the inspection of explanations
generated by software. The implementation languages are Java and
Prolog. The software produces explanation in various forms that
stresses on the causal theories in the chemical system which can be
effectively used to support learning.
Abstract: In the frame of the European Union project entitled EU-Families and Adolescents Quit Tobacco (www.eufaqt.eu) focus group analysis has been carried out in Hungary to acquire qualitative information on attitudes towards smoking in groups of adolescents, parents and educators, respectively. It rendered to identify methods for smoking prevention/ intervention with family approach. The results explored the role of the family in smoking behaviour. Teachers do not feel responsibility in prevention or cessation of smoking. Adolescents are not aware of the addictive effect of the cigarette. Water pipe is popular among adolescent, therefore spreading of more information needed on the harmful effects of water pipe. We outlined the requirement for professionals to provide interventions. Partnership of EU-FAQT project has worked out antismoking interventions for adolescents and their families conducted by psychologists to ensure skill development to prevent and quit tobacco.
Abstract: This study attempted to compare the sexual perceptions and behaviors of male and female married Ilocanos. Data were gathered from 1,374 married Ilocanos (687 husbands and 687 wives) from nine municipalities and one city of the First District of Ilocos Sur. Findings showed that the male and female married Ilocanos differ in their psychological and physical sexual perceptions, but they had common social and spiritual sexual perceptions. Moreover, they were consistent in their behaviors towards sex, except for their behaviour after sex without reaching orgasm, wherein the males feel bad after having sex without reaching orgasm, while the females simply sleep it off.