Abstract: Robot manipulators are highly coupled nonlinear
systems, therefore real system and mathematical model of dynamics
used for control system design are not same. Hence, fine-tuning of
controller is always needed. For better tuning fast simulation speed
is desired. Since, Matlab incorporates LAPACK to increase the speed
and complexity of matrix computation, dynamics, forward and
inverse kinematics of PUMA 560 is modeled on Matlab/Simulink in
such a way that all operations are matrix based which give very less
simulation time. This paper compares PID parameter tuning using
Genetic Algorithm, Simulated Annealing, Generalized Pattern Search
(GPS) and Hybrid Search techniques. Controller performances for all
these methods are compared in terms of joint space ITSE and
cartesian space ISE for tracking circular and butterfly trajectories.
Disturbance signal is added to check robustness of controller. GAGPS
hybrid search technique is showing best results for tuning PID
controller parameters in terms of ITSE and robustness.
Abstract: The protection of parallel transmission lines has been a challenging task due to mutual coupling between the adjacent circuits of the line. This paper presents a novel scheme for detection and classification of faults on parallel transmission lines. The proposed approach uses combination of wavelet transform and neural network, to solve the problem. While wavelet transform is a powerful mathematical tool which can be employed as a fast and very effective means of analyzing power system transient signals, artificial neural network has a ability to classify non-linear relationship between measured signals by identifying different patterns of the associated signals. The proposed algorithm consists of time-frequency analysis of fault generated transients using wavelet transform, followed by pattern recognition using artificial neural network to identify the type of the fault. MATLAB/Simulink is used to generate fault signals and verify the correctness of the algorithm. The adaptive discrimination scheme is tested by simulating different types of fault and varying fault resistance, fault location and fault inception time, on a given power system model. The simulation results show that the proposed scheme for fault diagnosis is able to classify all the faults on the parallel transmission line rapidly and correctly.
Abstract: This paper presents a new version of the SVM mixture algorithm initially proposed by Kwok for classification and regression problems. For both cases, a slight modification of the mixture model leads to a standard SVM training problem, to the existence of an exact solution and allows the direct use of well known decomposition and working set selection algorithms. Only the regression case is considered in this paper but classification has been addressed in a very similar way. This method has been successfully applied to engine pollutants emission modeling.
Abstract: The goal of the study reported in the paper was to
determine whether Ambient Occlusion Shading (AOS) has a significant effect on users' perception of American Sign Language (ASL) finger spelling animations. Seventy-one (71) subjects
participated in the study; all subjects were fluent in ASL. The participants were asked to watch forty (40) sign language animation
clips representing twenty (20) finger spelled words. Twenty (20) clips did not show ambient occlusion, whereas the other twenty (20) were
rendered using ambient occlusion shading. After viewing each animation, subjects were asked to type the word being finger-spelled and rate its legibility. Findings show that the presence of AOS had a significant effect on the subjects perception of the signed words.
Subjects were able to recognize the animated words rendered with AOS with higher level of accuracy, and the legibility ratings of the animations showing AOS were consistently higher across subjects.
Abstract: In this paper, we investigate the solution of a two dimensional parabolic free boundary problem. The free boundary of this problem is modelled as a nonlinear integral equation (IE). For this integral equation, we propose an asymptotic solution as time is near to maturity and develop an integral iterative method. The computational results reveal that our asymptotic solution is very close to the numerical solution as time is near to maturity.
Abstract: The purpose of the study was to investigate the
effectiveness of ICT training workshop of tutors of Allama Iqbal
Open University Pakistan. The study was delimited to tutors of
Multan region. The total sample comprised of 100 tutors. All the
tutors who participated in ICT training workshop in Multan region
were taken as sample in the study. A questionnaire having two parts,
based on five point rating scale was developed by the researcher. Part
one was about the competency level of computer skills while Part
two was based on items related to training delivery, structure and
content. Part One of questionnaire had five levels of competency
about computer skills. The questionnaire was personally administered
and collected back by the researcher himself on the last day of
workshop.
The collected data were analyzed by using descriptive statistics.
Through this study it was found that majority of the tutors strongly
agreed that training enhanced their computer skills. Majority of the
respondents consider themselves to be generally competent in the use
of computer. They also agreed that there was appropriate
infrastructure and technical support in lab during training workshop.
Moreover, it was found that the training imparted the knowledge of
pedagogy of using computers for distance education.
Abstract: In this paper, a system level behavioural model for RF
power amplifier, which exhibits memory effects, and based on multibranch
system is proposed. When higher order terms are included,
the memory polynomial model (MPM) exhibits numerical
instabilities. A set of memory orthogonal polynomial model
(OMPM) is introduced to alleviate the numerical instability problem
associated to MPM model. A data scaling and centring algorithm was
applied to improve the power amplifier modeling accuracy.
Simulation results prove that the numerical instability can be greatly
reduced, as well as the model precision improved with nonlinear
model.
Abstract: Due to a high unemployment rate among local people
and a high reliance on expatriate workers, the governments in the
Gulf Co-operation Council (GCC) countries have been implementing
programmes of localisation (replacing foreign workers with GCC
nationals). These programmes have been successful in the public
sector but much less so in the private sector. However, there are now
insufficient jobs for locals in the public sector and the onus to provide
employment has fallen on the private sector. This paper is concerned
with a study, which is a work in progress (certain elements are
complete but not the whole study), investigating the effective
implementation of localisation policies in four- and five-star hotels in
the Kingdom of Saudi Arabia (KSA) and the United Arab Emirates
(UAE). The purpose of the paper is to identify the research gap, and
to present the need for the research. Further, it will explain how this
research was conducted.
Studies of localisation in the GCC countries are under-represented
in scholarly literature. Currently, the hotel sectors in KSA and UAE
play an important part in the countries’ economies. However, the
total proportion of Saudis working in the hotel sector in KSA is
slightly under 8%, and in the UAE, the hotel sector remains highly
reliant on expatriates. There is therefore a need for research on
strategies to enhance the implementation of the localisation policies
in general and in the hotel sector in particular.
Further, despite the importance of the hotel sector to their
economies, there remains a dearth of research into the
implementation of localisation policies in this sector. Indeed, as far as
the researchers are aware, there is no study examining localisation in
the hotel sector in KSA, and few in the UAE. This represents a
considerable research gap.
Regarding how the research was carried out, a multiple case study
strategy was used. The four- and five-star hotel sector in KSA is one
of the cases, while the four- and five-star hotel sector in the UAE is
the other case. Four- and five-star hotels in KSA and the UAE were
chosen as these countries have the longest established localisation
policies of all the GCC states and there are more hotels of these
classifications in these countries than in any of the other Gulf
countries. A literature review was carried out to underpin the
research. The empirical data were gathered in three phases. In order
to gain a pre-understanding of the issues pertaining to the research
context, Phase I involved eight unstructured interviews with officials
from the Saudi Commission for Tourism and Antiquities (three
interviewees); the Saudi Human Resources Development Fund (one);
the Abu Dhabi Tourism and Culture Authority (three); and the Abu
Dhabi Development Fund (one).
In Phase II, a questionnaire was administered to 24 managers and
24 employees in four- and five-star hotels in each country to obtain
their beliefs, attitudes, opinions, preferences and practices concerning
localisation.
Unstructured interviews were carried out in Phase III with six
managers in each country in order to allow them to express opinions
that may not have been explored in sufficient depth in the
questionnaire. The interviews in Phases I and III were analysed using
thematic analysis and SPSS will be used to analyse the questionnaire
data.
It is recommended that future research be undertaken on a larger
scale, with a larger sample taken from all over KSA and the UAE
rather than from only four cities (i.e., Riyadh and Jeddah in KSA and
Abu Dhabi and Sharjah in the UAE), as was the case in this research.
Abstract: This paper presents implementation of attitude controller for a small UAV using field programmable gate array (FPGA). Due to the small size constrain a miniature more compact and computationally extensive; autopilot platform is needed for such systems. More over UAV autopilot has to deal with extremely adverse situations in the shortest possible time, while accomplishing its mission. FPGAs in the recent past have rendered themselves as fast, parallel, real time, processing devices in a compact size. This work utilizes this fact and implements different attitude controllers for a small UAV in FPGA, using its parallel processing capabilities. Attitude controller is designed in MATLAB/Simulink environment. The discrete version of this controller is implemented using pipelining followed by retiming, to reduce the critical path and thereby clock period of the controller datapath. Pipelined, retimed, parallel PID controller implementation is done using rapidprototyping and testing efficient development tool of “system generator", which has been developed by Xilinx for FPGA implementation. The improved timing performance enables the controller to react abruptly to any changes made to the attitudes of UAV.
Abstract: In the present article, nonlinear vibration analysis of
single layer graphene sheets is presented and the effect of small
length scale is investigated. Using the Hamilton's principle, the three
coupled nonlinear equations of motion are obtained based on the von
Karman geometrical model and Eringen theory of nonlocal
continuum. The solutions of Free nonlinear vibration, based on a one
term mode shape, are found for both simply supported and clamped
graphene sheets. A complete analysis of graphene sheets with
movable as well as immovable in-plane conditions is also carried out.
The results obtained herein are compared with those available in the
literature for classical isotropic rectangular plates and excellent
agreement is seen. Also, the nonlinear effects are presented as
functions of geometric properties and small scale parameter.
Abstract: Automatic currency note recognition invariably
depends on the currency note characteristics of a particular country
and the extraction of features directly affects the recognition ability.
Sri Lanka has not been involved in any kind of research or
implementation of this kind. The proposed system “SLCRec" comes
up with a solution focusing on minimizing false rejection of notes.
Sri Lankan currency notes undergo severe changes in image quality
in usage. Hence a special linear transformation function is adapted to
wipe out noise patterns from backgrounds without affecting the
notes- characteristic images and re-appear images of interest. The
transformation maps the original gray scale range into a smaller
range of 0 to 125. Applying Edge detection after the transformation
provided better robustness for noise and fair representation of edges
for new and old damaged notes. A three layer back propagation
neural network is presented with the number of edges detected in row
order of the notes and classification is accepted in four classes of
interest which are 100, 500, 1000 and 2000 rupee notes. The
experiments showed good classification results and proved that the
proposed methodology has the capability of separating classes
properly in varying image conditions.
Abstract: The utilisation of Industrial Building System (IBS) in construction industry will lead to a safe site condition since minimum numbers of workers are required to be on-site, timely material delivery, systematic component storage, reduction of construction material and waste. These matters are being promoted in the Construction Industry Master Plan (CIMP 2006-2015). However, the enabling factors of IBS that will foster a safer working environment are indefinite; on that basis a research has been conducted. The purpose of this paper is to discuss and identify the relevant factors towards safety improvement for IBS. A quantitative research by way of questionnaire surveys have been conducted to 314 construction companies. The target group was Grade 5 to Grade 7 contractors registered with Construction Industry Development Board (CIDB) which specialise in IBS. The findings disclosed seven factors linked to the safety improvement of IBS construction site in Malaysia. The factors were historical, economic, psychological, technical, procedural, organisational and the environmental factors. From the findings, a psychological factor ranked as the highest and most crucial factor contributing to safer IBS construction site. The psychological factor included the self-awareness and influences from workmates behaviour. Followed by organisational factors, where project management style will encourage the safety efforts. From the procedural factors, it was also found that training was one of the significant factors to improve safety culture of IBS construction site. Another important finding that formed as a part of the environmental factor was storage of IBS components, in which proper planning of the layout would able to contribute to a safer site condition. To conclude, in order to improve safety of IBS construction site, a welltrained and skilled workers are required for IBS projects, thus proper training is permissible and should be emphasised.
Abstract: This paper presents an approach for early breast
cancer diagnostic by employing combination of artificial neural
networks (ANN) and multiwaveletpacket based subband image
decomposition. The microcalcifications correspond to high-frequency
components of the image spectrum, detection of microcalcifications
is achieved by decomposing the mammograms into different
frequency subbands,, reconstructing the mammograms from the
subbands containing only high frequencies. For this approach we
employed different types of multiwaveletpacket. We used the result
as an input of neural network for classification. The proposed
methodology is tested using the Nijmegen and the Mammographic
Image Analysis Society (MIAS) mammographic databases and
images collected from local hospitals. Results are presented as the
receiver operating characteristic (ROC) performance and are
quantified by the area under the ROC curve.
Abstract: The existing image coding standards generally degrades at low bit-rates because of the underlying block based Discrete Cosine Transform scheme. Over the past decade, the success of wavelets in solving many different problems has contributed to its unprecedented popularity. Due to implementation constraints scalar wavelets do not posses all the properties such as orthogonality, short support, linear phase symmetry, and a high order of approximation through vanishing moments simultaneously, which are very much essential for signal processing. New class of wavelets called 'Multiwavelets' which posses more than one scaling function overcomes this problem. This paper presents a new image coding scheme based on non linear approximation of multiwavelet coefficients along with multistage vector quantization. The performance of the proposed scheme is compared with the results obtained from scalar wavelets.
Abstract: Reliable secure multicast communication in mobile
adhoc networks is challenging due to its inherent characteristics of
infrastructure-less architecture with lack of central authority, high
packet loss rates and limited resources such as bandwidth, time and
power. Many emerging commercial and military applications require
secure multicast communication in adhoc environments. Hence key
management is the fundamental challenge in achieving reliable
secure communication using multicast key distribution for mobile
adhoc networks. Thus in designing a reliable multicast key
distribution scheme, reliability and congestion control over
throughput are essential components. This paper proposes and
evaluates the performance of an enhanced optimized multicast cluster
tree algorithm with destination sequenced distance vector routing
protocol to provide reliable multicast key distribution. Simulation
results in NS2 accurately predict the performance of proposed
scheme in terms of key delivery ratio and packet loss rate under
varying network conditions. This proposed scheme achieves
reliability, while exhibiting low packet loss rate with high key
delivery ratio compared with the existing scheme.
Abstract: The current sheath dynamics in plasma focus facilities
is the most important factors. In this paper the current sheath velocity
at three dimensional with Sahand plasma focus facility is
investigated. For this purpose the discharge is produced in argon gas
with deposited energy lying in the range of 20-37kJ. The current
sheath is monitored using two tridimensional magnetic probes. These
probes installed near the surface of the interior electrode (anode) at
125mm from the anode axis (pinch place). The effect of gas pressure
on the current sheath velocity also is investigated.
Abstract: The increasing demand for higher data rates in wireless communication systems has led to the more effective and efficient use of all allocated frequency bands. In order to use the whole bandwidth at maximum efficiency, one needs to have RF power amplifiers with a higher linear level and memory-less performance. This is considered to be a major challenge to circuit designers. In this thesis the linearity and memory are studied and examined via the behavior of the intermodulation distortion (IMD). A major source of the in-band distortion can be shown to be influenced by the out-of-band impedances presented at either the input or the output of the device, especially those impedances terminated the low frequency (IF) components. Thus, in order to regulate the in-band distortion, the out of-band distortion must be controllable. These investigations are performed on a 12W LDMOS device characterised at 2.1 GHz within a purpose built, high-power measurement system.
Abstract: In this paper, a Bayesian Network (BN) based system
is presented for providing clinical decision support to healthcare
practitioners in rural or remote areas of India for young infants or
children up to the age of 5 years. The government is unable to
appoint child specialists in rural areas because of inadequate number
of available pediatricians. It leads to a high Infant Mortality Rate
(IMR). In such a scenario, Intelligent Pediatric System provides a
realistic solution. The prototype of an intelligent system has been
developed that involves a knowledge component called an Intelligent
Pediatric Assistant (IPA); and User Agents (UA) along with their
Graphical User Interfaces (GUI). The GUI of UA provides the
interface to the healthcare practitioner for submitting sign-symptoms
and displaying the expert opinion as suggested by IPA. Depending
upon the observations, the IPA decides the diagnosis and the
treatment plan. The UA and IPA form client-server architecture for
knowledge sharing.
Abstract: In this paper, we propose the low-MAC FEC controller for practical implementation of JPEG2000 image transmission using IEEE 802.15.4. The proposed low-MAC FEC controller has very small HW size and spends little computation to estimate channel state. Because of this advantage, it is acceptable to apply IEEE 802.15.4 which has to operate more than 1 year with battery. For the image transmission, we integrate the low-MAC FEC controller and RCPC coder in sensor node of LR-WPAN. The modified sensor node has increase of 3% hardware size than conventional zigbee sensor node.
Abstract: Knowing about the customer behavior in a grocery has
been a long-standing issue in the retailing industry. The advent of
RFID has made it easier to collect moving data for an individual
shopper's behavior. Most of the previous studies used the traditional
statistical clustering technique to find the major characteristics of
customer behavior, especially shopping path. However, in using the
clustering technique, due to various spatial constraints in the store,
standard clustering methods are not feasible because moving data such
as the shopping path should be adjusted in advance of the analysis,
which is time-consuming and causes data distortion. To alleviate this
problem, we propose a new approach to spatial pattern clustering
based on the longest common subsequence. Experimental results using
real data obtained from a grocery confirm the good performance of the
proposed method in finding the hot spot, dead spot and major path
patterns of customer movements.