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Approximating one-dimensional coupled shallow-water equations for predicting tsunami wave propagation using finite difference method
No full textMaster of Science in Engineering MathematicsSeveral countries on the Indian Ocean are hit by the tsunami on 26th December 2004. The tsunami is a rare phenomenon compared to other natural hazards. In order to enhance the preparedness of the people due to the tsunami, the tsunami wave
propagation is predicted. Hence one-dimensional shallow-water equations are used in this study since the tsunami is considered as a shallow-water wave. The shallow-water equations are discretized using explicit finite difference method. Then, the numerical
method is validated with -method and analytical solution for free surface wave damping problem as to ensure that the proposed method is suitable for solving onedimensional shallow-water equations. The tsunami wave heights and effects show a
high variability along the coastline. One way to study this complexity is by simulating
the tsunami wave propagation. To simulate the tsunami, the boundary conditions, initial
conditions, spatial and time step sizes, as well as the shallow-water equations in finite
difference form, are coded into MATLAB software. The results showed that the
tsunami wave is propagating towards the coastline as the time increases. The simulation
results had successfully predicted the behaviour of tsunami wave propagation near the
coastline
Effect of thermoplastic polyurethane on properties of polyvinyl chloride in designing bedpan
No full textMaster of Science in Materials EngineeringCommercialized bedpan made from hard plastic gives discomfort to the patients. The study was perform to improved. The present study determines the mechanical, physical and thermal properties of TPU/PVC blend in order to be used as material to fabricate a bedpan. TPU and PVC were mixed by melt-mixing method and were undergoing hot press compression molding to make a sample. The samples of PVC/TPU with ratio 90/10, 70/30 and 50/50 were subjected to tensile, water absorption, chemical resistance, Scaning Electron Microscopic (SEM), Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetric (DSC) test. The simulation analysis using ANSYS workbench software was performed at the end of test. 50TPU was chosen as the best ratio of TPU/PVC blend because they have good tensile strength, lower modulus and high elasticity. The
blending of TPU and PVC has decreased the percentage of water absorption of TPU since TPU has highest water gain due to hydrophilic nature and PVC has hydrophobic nature. Hydrochloric acid (HCl) had a stronger effect on TPU/PVC blend compared to sodium hydroxide (NaOH) for all blend compositions for chemical resistance test. The result of SEM micrograph shows that the sample became smoother when more TPU was added. The 50TPU sample exhibits smoother surface and cluster of blend on its surface diminish when increasing TPU content. TGA result shows that the decomposition occur in two stage for TPU/PVC blend. The decomposition of PVC was lower than TPU and higher than TPU/PVC blend. Based on DSC result, TPU/PVC blend revealed one transitions melting temperature (Tm) formed for sample of 10TPU, 30TPU and 50TPU
The moderating effect of the internal ownership on the relationship between the effectiveness of Board of Directors and Executive Compensation with earnings management in the Amman Stock Exchange
No full textDoctor of Philosophy in AccountingThe primary goal of this study is to determine the level of earnings management (EM) practices in Jordanian capital market and the effectiveness role of the corporate governance in mitigating these practices especially after adopting the Jordanian
corporate code in 2009. Therefore, this study revisits the literature on the relationship between the factors of the effectiveness of the board of directors at the individual level and as a bundle through creating a score of effectiveness for nine board of directors
factors. This study also investigates how the effectiveness of board of directors and the executive compensations are moderated by internal ownership “managerial and family ownership” to mitigate EM. In this term, four theories formed the theoretical foundation of this study. The agency theory, the resource dependence theory and the positive accounting theory predict that corporate governance practices would play an important role in improving the financial reporting through the monitoring role, resource dependence role and ability to combining the interest of the contractual parties. However, the institutional theory refers to the possibility that these practices can be as an imitation for the market “isomorphism” and social pressure then achieve the desired regulation. Most of the prior studies focused on the traditional interaction among corporate governance mechanisms and EM, thus, neglected the variance of these practices that can be attributed to the business environment and the nature of ownership structure. Consequently, this study sheds light on whether the central or traditional agency problem existed. Moreover, to achieve the objectives of this research Kothari et al. 2005 model is used as a proxy of EM. Three models were developed and tested to answer the research questions. These models were tested using the panel data analysis methods over a sample of 798 firm-observation collected from the Jordanian nonfinancial firms listed in the ASE during the period of 2009-2015. The findings of the first model (Random-effect) provides each of the board independence, meeting frequency, CEO duality, audit committee, directors tenures and the executive compensations significantly affect the EM practices
Electronic nose based bacteria species detection in diabetic foot infection
No full textMaster of Science in Biomedical Electronic EngineeringThis thesis presents a fundamental study of early bacteria detection using electronic nose. There is a need for early detection of bacterial infection in order to give effective treatment for diabetic foot infection. To date, the clinical method based on sample
culture is a standard practise used by microbiologist to detect and classify bacteria species. The cultured samples were taken from debridement of diabetic foot wound can take up to two to three days. Alternatively, identification of causative bacteria from their
odours could provide an early and rapid diagnosis and therefore allow initiating
appropriate treatment. This research project used an existing sensor technology in the
form of an e-nose in conjunction with data processing and classification methods to
classify six types of bacteria, common causal organism of diabetic foot infection from
their odours. There were three main aims in this research study namely, to identify
different bacteria species in different culture media using e-nose, investigate the ability
of the e-nose to detect cultured bacteria species in blood agar medium in less than 24
hours and study in-vitro diagnosis of single and poly microbial species targeted for
diabetic foot infection using e-nose. Cyranose 320 e-nose device which consist of 32
gas sensor array, measures the changes in resistance of each chemical sensor which can
detect and classify bacteria according to their volatile organic compound (VOC). The
sniffing process or e-nose measurements were performed immediately after placing the
petri dish of bacteria suspension in a special stainless steel container. The odour data
were collected and stored as numerical values within data files in the computer system.
Once the dataset extracted, various classification experiments were performed.
Comparisons were made and conclusions were drawn from the performance of various
data analysis and classification methods. The classification methods used in this work
include Support Vector Machine (SVM), K Nearest Neighbor (KNN), Linear
Discriminant Analysis (LDA) and Probability Neural Network (PNN). 100% accuracy
was achieved using all classifiers for identification of bacteria species in three different
culture media. The results confirmed that possible to discriminate different bacterial
groups on diabetic foot infection regardless of different culture media used for bacteria
growth. For early detection of six bacterial species, the best accuracy was 96 %. This
was achieved using KNN with k value of 2 and 6 using Euclidean and City block
distance. For study in-vitro diagnosis of single and poly microbial species, the best
accuracy was up to 90 % for all classifiers. Thus, this fundamental work on the
classification of bacteria odours using e-nose can be a „real world‟ application if this
technology is successfully developed. The methods and techniques discussed here are
one step towards the goal of introducing multi class sensor systems into everyday use.
The conclusion of this thesis is that an e-nose can detect and classify different types of
bacteria on diabetic foot infection with convincing results which are comparable to the
existing standard procedure
Time-frequency analysis based methods for classification of newborn cry signals
No full textDoctor of Philosophy in Medical Electronic EngineeringThe infant cry classification implies non invasive objective methods, classification of
different patterns of infant cry utterances and adoption of artificial and digital signal
processing techniques. It has been commenced past decades ago to overcome the
limitations of subjective methods in particularly auditory perception and human
spectrographic analysis, which are relying on clinical rater‘s experience and expertise.
This thesis addresses the development of an objective method for classification of
newborn cries primarily using time-frequency (t-f) methods. Towards this aim, a novel
investigation using two different t-f based signal processing approaches was performed:
(a) Quadratic time-frequency distributions (QTFDs): Spectrogram (SPEC), Wigner-
Ville distribution (WVD), Smoothed-Wigner Ville distribution (SWVD), Choi-William
distribution (CWD) and Modified B-distribution (MBD), and (b) Wavelet packet
transform (WPT) based method: wavelet packet spectrum (Wpspectrum). The
effectiveness of the suggested t-f methods was analyzed using normal and different
pathological cry signals. The investigational cry signals were accessed from three
different origins of databases (Mexico, Hungary and Malaysia (self-developed
database). In order to investigate the effectiveness of the suggested t-f methods, eight
different cry experiments were suggested, including binary and multiclass problems. In
the binary domain, analysis of cry signals from different origin and the severity level of
pathological cry signals were considered for investigation. The framework of this work
was designed in two phases in order to compare the performance evaluation of the
suggested t-f methods with the state of the art attributes in the infant cry classification
area (Mel frequency cepstral coefficients (MFCCs) and Linear prediction coefficients
(LPCs)). Initially, the performance evaluation of the individual suggested t-f methods,
MFCCs and LPCs on different proposed cry datasets were performed. In this case, a
cluster of t-f based statistical features was extracted from the suggested t-f methods. The
performance evaluation in term of classification task was tackled using two different
supervised neural networks, namely Probabilistic Neural Network (PNN) and General
Regression Neural Network (GRNN). Subsequently, by considering the classification
performance, the best distribution from the QTFDs was selected. In the second phase, a
feature set, combination of MFCCs, LPCs and the extracted statistical features from the
best QTFDs and Wpspectrum was formed. Different feature selection techniques, such
as Plus-1-minus-r (LRS) and Information Gain (IGS) were applied on the formed
feature set to obtain a parsimonious subset of those features. The discrimination
capability of the selected feature vector in terms of classification accuracy was
evaluated using PNN and GRNN
Black-box modeling and adaptive control of hybrid thermoelectric refrigerator systems
No full textDoctor of Philosophy in Mechatronic EngineeringVaccines carrier has been used to keep the temperature within 2–8°C. However, a
poorly functioning vaccines carrier may expose the vaccines to freezing temperatures.
Hybrid Thermoelectric Refrigerator (H-TER) systems are developed in order to
transport sensitive vaccines to hospitals at accurate controlled temperature. The
refrigerator use air-to-air and direct thermoelectric heat pumps. This work reports on
modeling and control studies carried out for H-TER systems that can control low
temperature accurately. Different type of material containers (aluminium and stainless
steel) is used and comparisons between them are analyzed. The systems are nonlinear
and exhibits varying model parameters and dead-time. The objective of the study is to
investigate control strategies that are based on non-priori plant knowledge and yet
allowing for continuous adaptations of the controller to changing system dynamics. In
fact, the various cooling load also causes a reduction of refrigerator efficiency including
the fluctuation of imposed current level due to electronic component performance and
varied operating condition of thermoelectric module on cold and hot ends against time.
Thus an adaptive control system is considered to handle the problems that are stipulated
above. A black box modeling approach is chosen since this is needed for the
implementation of adaptive controllers. The H-TER systems have been identified using
both Recursive Least Squares (RLS) and Recursive Extended Least Squares (RELS)
methods. Since RELS has shown to give biased estimates for filtered data and slow
convergence estimates for unfiltered data, RLS has been chosen for the model as its
give a better representation of the systems. A second order model of H-TER I and HTER
II systems are found to adequately represent the system as it give best fit of 0.0009
and 0.0007 respectively which made the fourth order to be insignificant for
implementation. Validation procedures using second order model for online estimation,
show that the model is indeed a good representation of the H-TER systems. On-Off and
PI controllers are the commonly used in thermoelectric system is applied to this system
as case studies. PI controller shows better performance over On-Off controller in term
of steady state error
Design of syncronized photovoltaic and wind hybrid power generation system for street lighting application
No full textDoctor of Philosophy in Electrical Systems EngineeringFluctuation of wind energy and solar radiation that is inconsistent become a major challenge
to build alternative power generation. The uncertainties to two energy sources is a problem in
synchronizing. To build a plant, first performed testing the potential energy that can be
harnessed. Testing the potential of wind energy using Weibull distribution methods and
estimation of solar energy radiation using a model Annandale, Hargreaves and the proposed
model as well as to these three models were tested statistically using MATLAB simulation.
Wind energy and solar radiation are fluctuating and inconsistent results in the voltage
generated are not constant. For the voltage is not constant can be fixed using a buck-boost
converter. Buck-boost converter is a dc-dc converter that can increasing and decreasing the
voltage. Design buck-boost converter uses a combination of electronic components such as
inductors, capacitors, diodes, XL6009, TIP2955 and LM7815. Of a difficulty to combine the
two plants directly with a voltage are not constant. Merger of wind energy and solar radiation
using a microcontroller, which serves to connect or disconnect the two energy sources to the
electrical power system, if one or two sources of energy have a voltage less than or greater
than the voltage is specified, then the microcontroller works to break source energy to the
battery. If one or both energy sources have the same voltage with the voltage specified, then
the microcontroller to work connecting the energy source to the battery. Based on MATLAB
simulation that the potential for wind energy and solar radiation in Perlis show that wind
energy is low at maximum wind speed of 1.10 m/s in PDF 0.44 (in 2011) and a maximum
wind speed of 1.11 m/s in PDF 0.51 (2014), while the results of estimation and statistical
tests (CRM, RMSE and e%) for solar radiation using MATLAB shows that the proposed
model (combination Hargreaves and Annandale model) is better than model Hargreaves and
Annandale and energy of solar radiation is very good with solar radiation average 1,316
wh/m2 (above the standard value of 1,000 wh/m2). Design and development of buck-boost
converter with the addition of components Inductors 35.5 μH and capacitors 220 μF can
increasing and decreasing the voltage of the source of wind energy and solar radiation.
Implementation buck-boost converter in the synchronization system wind energy (WP) and
photovoltaic (PV) is used for charging batteries. The battery charging of 5-6 hours and
discharging the battery of 28 hours
An extended thomas-fermi model with clustering in nuclei
No full textDoctor of Philosophy in Theoretical PhysicsIn this study, a phenomenological theory of nuclei that includes clustering at the nuclear surface in a general form is presented. The theory elaborates the recently extracted large symmetry energy by Natowitz et al., at low densities of nuclear matter and is fully consistent with the static properties of nuclei. Clusters of all sizes and shapes together with medium alterations are included in a phenomenological way. Discussion about the symmetric nuclear matter properties are presented in detail. Arguments are stated, which bring to an equation of state of nuclear matter consistent with clustering in the low-density region. In addition, the justification and discussion about the properties of asymmetric nuclear matter are given. Due to the clustering, an interesting interpretation of the equation of state of asymmetric nuclear matter comes into view. An extended version of Thomas-Fermi theory is adopted as a framework for nuclei where it also consist of the phenomenological pairing and Wigner contributions. This theory relates the nuclear matter equation of state, which includes clustering at low densities, with clustering in nuclei at the nuclear surface. Calculations are carried out for different equations of state of nuclear matter. This study take into account binding energies of 2149 nuclei for N,Z 8. The significance of the quartic term in symmetry energy is illustrated at and below the saturation density of nuclear matter. It is demonstrated that it is greatly connected to the use of ab initio, a realistic equation of state of neutron matter, especially the contribution originating from the three neutron interactions and rather clustering. The causes for these are presented. The neutron skin thickness in nuclei is found to reduce significantly, for the reason of clustering. The developed theory predicts circumstances and methodologies to be examine both theoretically and experimentally
Factors affecting the intention to fully adopt the computer assisted audit tools and techniques (CAATTs) among external auditors in Jordan
No full textMaster of Science in AccountingComputer-Assisted Audit Tools and Techniques (CAATTs) are the tools and techniques
that enable auditors to automate tasks including client risk assessment, analysis of data,
and detection of fraud in order to increase audit quality. Nevertheless, it has been evident
that Jordanian companies are still involved in frauds such as tax evasion, fraud and
manipulation of financial statements especially in obtaining financing from banks.
Despite the advantages of adopting CAATTs in auditing practices, there is little evidence
about their adoption among external auditors in the Jordanian context. Hence, this study
aimed to fill this gap. The primary aims of this study were to explore the current usage of
CAATTs and further examine factors affecting the intention to fully adopt CAATTs
among Jordanian external auditors working in various national, international, and the
world’s Big 4 audit firms. The present study employed the Unified Theory of Acceptance
and Use of Technology (UTAUT) to identify factors affecting the intention to fully adopt
CAATTs. These factors included performance expectancy, effort expectancy, social
influence, facilitating conditions, and trust as an external factor. Online survey was
conducted in which a questionnaire was sent to 181 Jordanian external auditors that
yielded 54.14% response rate. Results have shown that performance expectancy, effort
expectancy and social influence were all positively related to the intention to fully adopt
CAATTs. Moreover, trust was positively related to performance expectancy and effort
expectancy. However, facilitating conditions and trust were not positively related to the
intention to fully adopt CAATTs. The findings have also indicated that a limited number
of only 8 respondents among the Jordanian external auditors surveyed had fully adopted
CAATTs. In this regard, most of the Jordanian audit firms were facing many obstacles
such as the lack of knowledge and training related to the usage of CAATTs. Thus, it is
recommended that the Jordanian professional accounting body should help the auditors
in Jordan to adopt CAATTs by developing training programs and organising conferences
to disseminate knowledge among all auditors about importance of adopting CAATTs.
Nonetheless, it should be noted that the survey was conducted between December and
January which may have not been an appropriate time to collect data from the auditors
because they would be busy preparing audit reports during this period. For future
research, it is suggested that the use of Generalized Audit Software (GAS) among internal
auditors or information technology auditors is examined by using the Technology-
Organization-Environment (TOE) framework
Development and characterization of Pennisetum Purpureum/pla biocomposite scaffold
No full textMaster of Science in Biomedical EngineeringThe mechanical, thermal, morphological properties and in vitro degradation study of a 3D porous Pennisetum purpureum (PP)/polylactic acid (PLA) based scaffold were investigated. In this study, a novel scaffold containing P. purpureum and PLA was produced using of the
solvent casting and particulate leaching method. PLA composite with various P. purpureum
contents (10 wt%, 20 wt%, and 30 wt%) were prepared and subsequently characterised.
The morphologies, structures and thermal behaviours of the prepared composite scaffolds
were characterised using field-emission scanning electron microscopy (FESEM), Fourier
transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric
analysis (TGA). The morphology was studied using FESEM; the scaffold possessed 70-200
μm-sized pores and had a greater porosity factor (99%) with a high level of
interconnectivity. The mechanical properties and in vitro degradation of the developed
porous scaffolds were further characterized. Compression tests were conducted to evaluate
the compressive strength and modulus of the scaffolds, according to ASTM F451-95. The
compression strength of the scaffolds was found to increase from 1.94 to 9.32 MPa, while
the compressive modulus increased from 1.73 to 5.25 MPa as the fillers’ content increased
from 0 wt% to 30 wt%. In this study, the synthesized composite scaffolds were immersed
in a PBS solution at 37 °C for 40 days. Interestingly, the degradation rate was reduced for
the PLA/PP20 scaffold, though insignificantly, this could be attributed to the improved
mechanical properties and stronger fibre-matrix interface. Microstructure changes after
degradation were observed using FESEM. The FESEM results indicated that a strong fibrematrix
interface was formed in the PLA/PP20 scaffold, which reflected the addition of P.
purpureum into PLA decreasing the degradation rate compared to in pure PLA scaffolds.
From the results, it can be concluded that the properties of the highly porous P.
purpureum/PLA scaffold developed in this study can be controlled and optimized. This can
be used to facilitate the construction of implantable tissue-engineered cartilage