Abstract: This paper presents a model for a modified T-junction
device for microspheres generation. The numerical model is
developed using a commercial software package: COMSOL
Multiphysics. In order to test the accuracy of the numerical model,
multiple variables, such as the flow rate of cross-flow, fluid properties,
structure, and geometry of the microdevice are applied. The results
from the model are compared with the experimental results in the
diameter of the microsphere generated. The comparison shows a good
agreement. Therefore the model is useful in further optimization of the
device and feedback control of microsphere generation if any.
Abstract: Exact solution of an unsteady MHD flow of elasticoviscous
fluid through a porous media in a tube of spherical cross
section under the influence of magnetic field and constant pressure
gradient has been obtained in this paper. Initially, the flow is
generated by a constant pressure gradient. After attaining the steady
state, the pressure gradient is suddenly withdrawn and the resulting
fluid motion in a tube of spherical cross section by taking into
account of the porosity factor and magnetic parameter of the
bounding surface is investigated. The problem is solved in two-stages
the first stage is a steady motion in tube under the influence of a
constant pressure gradient, the second stage concern with an unsteady
motion. The problem is solved employing separation of variables
technique. The results are expressed in terms of a non-dimensional
porosity parameter (K), magnetic parameter (m) and elasticoviscosity
parameter (β), which depends on the Non-Newtonian
coefficient. The flow parameters are found to be identical with that of
Newtonian case as elastic-viscosity parameter and magnetic
parameter tends to zero and porosity tends to infinity. It is seen that
the effect of elastico-viscosity parameter, porosity parameter and
magnetic parameter of the bounding surface has significant effect on
the velocity parameter.
Abstract: The main objective of this paper is to provide a new
methodology for road safety assessment in Oman through the
development of suitable accident prediction models. GLM technique
with Poisson or NBR using SAS package was carried out to develop
these models. The paper utilized the accidents data of 31 un-signalized
T-intersections during three years. Five goodness-of-fit
measures were used to assess the overall quality of the developed
models. Two types of models were developed separately; the flow-based
models including only traffic exposure functions, and the full
models containing both exposure functions and other significant
geometry and traffic variables.
The results show that, traffic exposure functions produced much
better fit to the accident data. The most effective geometric variables
were major-road mean speed, minor-road 85th percentile speed,
major-road lane width, distance to the nearest junction, and right-turn
curb radius.
The developed models can be used for intersection treatment or
upgrading and specify the appropriate design parameters of T-intersections.
Finally, the models presented in this thesis reflect the intersection
conditions in Oman and could represent the typical conditions in
several countries in the middle east area, especially gulf countries.
Abstract: This study examined how individuals in their
respective teams contributed to innovation performance besides
defining the term of innovation in their own respective views. This
study also identified factors that motivated University staff to
contribute to the innovation products. In addition, it examined
whether there is a significant relationship between professional
training level and the length of service among university staff
towards innovation and to what extent do the two variables
contributed towards innovative products. The significance of this
study is that it revealed the strengths and weaknesses of the
university staff when contributing to innovation performance.
Stratified-random sampling was employed to determine the samples
representing the population of lecturers in the study, involving 123
lecturers in one of the local universities in Malaysia. The method
employed to analyze the data is through categorizing into themes for
the open-ended questions besides using descriptive and inferential
statistics for the quantitative data. This study revealed that two types
of definition for the term “innovation” exist among the university
staff, namely, creation of new product or new approach to do things
as well as value-added creative way to upgrade or improve existing
process and service to be more efficient. This study found that the
most prominent factor that propels them towards innovation is to
improve the product in order to benefit users, followed by selfsatisfaction
and recognition. This implies that the staff in the
organization viewed the creation of innovative products as a process
of growth to fulfill the needs of others and also to realize their
personal potential. This study also found that there was only a
significant relationship between the professional training level and
the length of service of 4 - 6 years among the university staff. The
rest of the groups based on the length of service showed that there
was no significant relationship with the professional training level
towards innovation. Moreover, results of the study on directional
measures depicted that the relationship for the length of service of 4-
6 years with professional training level among the university staff is
quite weak. This implies that good organization management lies on
the shoulders of the key leaders who enlighten the path to be
followed by the staff.
Abstract: Depositional environment and source potential of the
different organic-rich levels of Devonian age (up to 990m thick) from
the onshore EC-1 well (Southern Tunisia) were investigated based on
the analysis of more than 130 cutting samples by different
geochemical techniques (Rock-Eval pyrolysis, GC-MS). The
obtained results including Rock Eval Pyrolysis data and biomarker
distribution (terpanes, steranes and aromatics) have been used to
describe the depositional environment and to assess the thermal
maturity of the Devonian organic matter. These results show that the
Emsian deposits exhibit poor to fair TOC contents. The associated
organic matter is composed of mixed kerogen (type II/III), as
indicated by the predominance of C29 steranes over C27 and C28
homologous, that was deposited in a slightly reduced environment
favoring organic matter preservation. Thermal maturity assessed from
Tmax, TNR and MPI-1 values shows a mature stage of organic
matter. The Middle Devonian (Eifelian) shales are rich in type II
organic matter that was deposited in an open marine depositional
environment. The TOC values are high and vary between 2 and 7%
indicating good to excellent source rock. The relatively high HI
values (reaching 547 mg HC/g TOC) and the low values of t19/t23
tricyclic terpane ratio (< 0.2) confirm the marine origin of the organic
matter (type II). During the Upper Devonian, the organic matter was
deposited under variable redox conditions, oxic to suboxic which is
clearly indicated by the low C35/C34 hopanes ratio, immature to
marginally mature with the vitrinite reflectance ranging from 0.5 to
0.7 Ro and Tmax value of 426°C-436 °C and the TOC values range
between 0.8% to 4%.
Abstract: In this paper, a direct power control (DPC)
strategies have been investigated in order to control a high
power AC/DC converter with time variable load. This converter
is composed of a three level three phase neutral point clamped
(NPC) converter as rectifier and an H-bridge four quadrant
current control converter. In the high power application,
controller not only must adjust the desire outputs but also
decrease the level of distortions which are injected to the network
from the converter. Regarding to this reason and nonlinearity
of the power electronic converter, the conventional controllers
cannot achieve appropriate responses. In this research, the
precise mathematical analysis has been employed to design the
appropriate controller in order to control the time variable
load. A DPC controller has been proposed and simulated using
Matlab/ Simulink. In order to verify the simulation result, a real
time simulator- OPAL-RT- has been employed. In this paper,
the dynamic response and stability of the high power NPC
with variable load has been investigated and compared with
conventional types using a real time simulator. The results proved
that the DPC controller is more stable and has more precise
outputs in comparison with conventional controller.
Abstract: The aim of software maintenance is to maintain
the software system in accordance with advancement in software
and hardware technology. One of the early works on software
maintenance is to extract information at higher level of abstraction. In
this paper, we present the process of how to design an information
extraction tool for software maintenance. The tool can extract the
basic information from old programs such as about variables, based
classes, derived classes, objects of classes, and functions. The tool
have two main parts; the lexical analyzer module that can read the
input file character by character, and the searching module which
users can get the basic information from the existing programs. We
implemented this tool for a patterned sub-C++ language as an input
file.
Abstract: This study analyzes the innovative orientation of the
Croatian entrepreneurs. Innovative orientation is represented by the
perceived extent to which an entrepreneur’s product or service or
technology is new, and no other businesses offer the same product.
The sample is extracted from the GEM Croatia Adult Population
Survey dataset for the years 2003-2013. We apply descriptive
statistics, t-test, Chi-square test and logistic regression. Findings
indicate that innovative orientations vary with personal, firm, meso
and macro level variables, and between different stages in
entrepreneurship process. Significant predictors are occupation of the
entrepreneurs, size of the firm and export aspiration for both early
stage and established entrepreneurs. In addition, fear of failure,
expecting to start a new business and seeing an entrepreneurial career
as a desirable choice are predictors of innovative orientation among
early stage entrepreneurs.
Abstract: In urban context, urban nodes such as amenity or
hazard will certainly affect house price, while classic hedonic analysis
will employ distance variables measured from each urban nodes.
However, effects from distances to facilities on house prices generally
do not represent the true price of the property. Distance variables
measured on the same surface are suffering a problem called
multicollinearity, which is usually presented as magnitude variance
and mean value in regression, errors caused by instability. In this paper,
we provided a theoretical framework to identify and gather the data
with less bias, and also provided specific sampling method on locating
the sample region to avoid the spatial multicollinerity problem in three
distance variable’s case.
Abstract: Stratified double extreme ranked set sampling
(SDERSS) method is introduced and considered for estimating the
population mean. The SDERSS is compared with the simple random
sampling (SRS), stratified ranked set sampling (SRSS) and stratified
simple set sampling (SSRS). It is shown that the SDERSS estimator
is an unbiased of the population mean and more efficient than the
estimators using SRS, SRSS and SSRS when the underlying
distribution of the variable of interest is symmetric or asymmetric.
Abstract: The objective of countercyclical capital buffer is to
encourage banks to build up buffers in good times that can be drawn
down in bad times. The aim of the report is to assess such decisions
by banks derived from three approaches. The approaches are the
aggregate credit-to-GDP ratio, credit growth as well as banking
sector profits. The approaches are implemented for Estonia, Latvia
and Lithuania for the time period 2000-2012. The report compares
three approaches and analyses their relevance to the Baltic States by
testing the correlation between a growth in studied variables and a
growth of corresponding gaps. Methods used in the empirical part of
the report are econometric analysis as well as economic analysis,
development indicators, relative and absolute indicators and other
methods. The research outcome is a cross-Baltic comparison of two
alternative approaches to establish or release a countercyclical capital
buffer by banks and their implications for each Baltic country.
Abstract: Two finite element (FEM) models are presented in
this paper to address the random nature of the response of glued
timber structures made of wood segments with variable elastic
moduli evaluated from 3600 indentation measurements. This total
database served to create the same number of ensembles as was the
number of segments in the tested beam. Statistics of these ensembles
were then assigned to given segments of beams and the Latin
Hypercube Sampling (LHS) method was called to perform 100
simulations resulting into the ensemble of 100 deflections subjected
to statistical evaluation. Here, a detailed geometrical arrangement of
individual segments in the laminated beam was considered in the
construction of two-dimensional FEM model subjected to in fourpoint
bending to comply with the laboratory tests. Since laboratory
measurements of local elastic moduli may in general suffer from a
significant experimental error, it appears advantageous to exploit the
full scale measurements of timber beams, i.e. deflections, to improve
their prior distributions with the help of the Bayesian statistical
method. This, however, requires an efficient computational model
when simulating the laboratory tests numerically. To this end, a
simplified model based on Mindlin’s beam theory was established.
The improved posterior distributions show that the most significant
change of the Young’s modulus distribution takes place in laminae in
the most strained zones, i.e. in the top and bottom layers within the
beam center region. Posterior distributions of moduli of elasticity
were subsequently utilized in the 2D FEM model and compared with
the original simulations.
Abstract: The present work describes the implementation of the
Enhanced Collaborative Optimization (ECO) multilevel architecture
with a gradient-based optimization algorithm with the aim of
performing a multidisciplinary design optimization of a generic
unmanned aerial vehicle with morphing technologies. The concepts
of weighting coefficient and dynamic compatibility parameter are
presented for the ECO architecture. A routine that calculates the
aircraft performance for the user defined mission profile and vehicle’s
performance requirements has been implemented using low fidelity
models for the aerodynamics, stability, propulsion, weight, balance
and flight performance. A benchmarking case study for evaluating
the advantage of using a variable span wing within the optimization
methodology developed is presented.
Abstract: Exact solution of an unsteady flow of elastico-viscous
fluid through a porous media in a tube of ellipsoidal cross section
under the influence of constant pressure gradient has been obtained in
this paper. Initially, the flow is generated by a constant pressure
gradient. After attaining the steady state, the pressure gradient is
suddenly withdrawn and the resulting fluid motion in a tube of
ellipsoidal cross section by taking into account of the porosity factor
of the bounding surface is investigated. The problem is solved in twostages
the first stage is a steady motion in tube under the influence of
a constant pressure gradient, the second stage concern with an
unsteady motion. The problem is solved employing separation of
variables technique. The results are expressed in terms of a nondimensional
porosity parameter (K) and elastico-viscosity parameter
(β), which depends on the Non-Newtonian coefficient. The flow
parameters are found to be identical with that of Newtonian case as
elastic-viscosity parameter tends to zero and porosity tends to
infinity. It is seen that the effect of elastico-viscosity parameter and
the porosity parameter of the bounding surface has significant effect
on the velocity parameter.
Abstract: Urban Search and Rescue (USAR) is a functional
capability that has been developed to allow the United Kingdom Fire
and Rescue Service to deal with ‘major incidents’ primarily involving
structural collapse. The nature of the work undertaken by USAR
means that staying out of a damaged or collapsed building structure is
not usually an option for search and rescue personnel. As a result
there is always a risk that they themselves could become victims. For
this paper, a systematic and investigative review using desk research
was undertaken to explore the role which structural engineering can
play in assisting search and rescue personnel to conduct structural
assessments when in the field. The focus is on how search and rescue
personnel can assess damaged and collapsed building structures, not
just in terms of structural damage that may been countered, but also
in relation to structural stability. Natural disasters, accidental
emergencies, acts of terrorism and other extreme events can vary
significantly in nature and ferocity, and can cause a wide variety of
damage to building structures. It is not possible or, even realistic, to
provide search and rescue personnel with definitive guidelines and
procedures to assess damaged and collapsed building structures as
there are too many variables to consider. However, understanding
what implications damage may have upon the structural stability of a
building structure will enable search and rescue personnel to better judge
and quantify risk from a life-safety standpoint. It is intended that this
will allow search and rescue personnel to make informed decisions
and ensure every effort is made to mitigate risk, so that they
themselves do not become victims.
Abstract: Over the years, it has been extensively established that
the practice of assuming a structure being fixed at base, leads to gross
errors in evaluation of its overall response due to dynamic loadings
and overestimations in design. The extent of these errors depends on
a number of variables; soil type being one of the major factor. This
paper studies the effect of Soil Structure Interaction (SSI) on multistorey
buildings with varying under-laying soil types after proper
validation of the effect of SSI. Analysis for soft, stiff and very stiff
base soils has been carried out, using a powerful Finite Element
Method (FEM) software package ANSYS v14.5. Results lead to
some very important conclusions regarding time period, deflection
and acceleration responses.
Abstract: In this paper, performances of shuffled frog leaping
algorithm was investigated on the stealth laser dicing process. Effect
of problem on the performance of the algorithm was based on the
tolerance of meandering data. From the customer specification it
could be less than five microns with the target of zero microns.
Currently, the meandering levels are unsatisfactory when compared
to the customer specification. Firstly, the two-level factorial design
was applied to preliminarily study the statistically significant effects
of five process variables. In this study one influential process variable
is integer. From the experimental results, the new operating condition
from the algorithm was superior when compared to the current
manufacturing condition.
Abstract: Internet financial reporting and corporate governance
issues are in the focus of academic and professional studies due to
their attributed importance by stakeholders of corporations. Major
aim of this study is to reveal the relationship between internet
financial reporting which is held as dependent variable and some
indicators of corporate governance such as the ratio of managerial
ownership, blockholder ownership, number of independent members
in the board of directors, frequency of meetings by audit committee
and education level of audit committee members which are held as
independent variables. Main purpose is to reveal the effect of
corporate governance on the voluntary efforts of Internet Financial
reporting. The scope of the research is limited to the Turkish
Corporations listed in Borsa Istanbul (Istanbul Stock Exchange) and
findings which are generated by means of SPSS software are revealed
in results section and interpreted in conclusions.
Abstract: The impact of Special Economic Zones (SEZs) has
been analyzed for many years by researchers. There are lot of
theoretical studies proving the SEZs importance for regional
development, however, there is lack of empirical studies (and they
are mainly focused on China market) that are based on available data.
The theoretical studies indicate the various impacts of enterprises
operating within SEZs on the economy. The article proves that, in
case of Poland, locating SEZs in municipalities is an important part
of increasing municipalities’ income. Therefore SEZs have a positive
impact on regional development. Municipality income is understood
as taxes paid by taxpayers who depend on SEZ companies’
performance. The analysis includes the Corporate Income Tax (CIT),
Personal Income Tax (PIT) and real estate tax. The effects of SEZs
on regional development were narrowed to a few variables that are
most significant for the financial system. The analysis indicates the
significant impact of SEZs on the amount of taxes influencing the
municipality budget.
Abstract: The paper presents a practical three-phase PWM
inverter suitable for low voltage, low rating energy efficient systems.
The work in the paper is conducted with the view to establishing the
significance of the loss contribution from the PWM inverter in the
determination of the complete losses of a photovoltaic (PV) arraypowered
induction motor drive water pumping system. Losses
investigated include; conduction and switching loss of the devices
and gate drive losses. It is found that the PWM inverter operates at a
reasonable variable efficiency that does not fall below 92%
depending on the load. The results between the simulated and
experimental results for the system with or without a maximum
power tracker (MPT) compares very well, within an acceptable range
of 2% margin.