Abstract: Fractal based digital image compression is a specific
technique in the field of color image. The method is best suited for
irregular shape of image like snow bobs, clouds, flame of fire; tree
leaves images, depending on the fact that parts of an image often
resemble with other parts of the same image. This technique has
drawn much attention in recent years because of very high
compression ratio that can be achieved. Hybrid scheme incorporating
fractal compression and speedup techniques have achieved high
compression ratio compared to pure fractal compression. Fractal
image compression is a lossy compression method in which selfsimilarity
nature of an image is used. This technique provides high
compression ratio, less encoding time and fart decoding process. In
this paper, fractal compression with quad tree and DCT is proposed
to compress the color image. The proposed hybrid schemes require
four phases to compress the color image. First: the image is
segmented and Discrete Cosine Transform is applied to each block of
the segmented image. Second: the block values are scanned in a
zigzag manner to prevent zero co-efficient. Third: the resulting image
is partitioned as fractals by quadtree approach. Fourth: the image is
compressed using Run length encoding technique.
Abstract: Myoelectric control system is the fundamental
component of modern prostheses, which uses the myoelectric signals
from an individual’s muscles to control the prosthesis movements.
The surface electromyogram signal (sEMG) being noninvasive has
been used as an input to prostheses controllers for many years.
Recent technological advances has led to the development of
implantable myoelectric sensors which enable the internal
myoelectric signal (MES) to be used as input to these prostheses
controllers. The intramuscular measurement can provide focal
recordings from deep muscles of the forearm and independent signals
relatively free of crosstalk thus allowing for more independent
control sites. However, little work has been done to compare the two
inputs. In this paper we have compared the classification accuracy of
six pattern recognition based myoelectric controllers which use
surface myoelectric signals recorded using untargeted (symmetric)
surface electrode arrays to the same controllers with multichannel
intramuscular myolectric signals from targeted intramuscular
electrodes as inputs. There was no significant enhancement in the
classification accuracy as a result of using the intramuscular EMG
measurement technique when compared to the results acquired using
the surface EMG measurement technique. Impressive classification
accuracy (99%) could be achieved by optimally selecting only five
channels of surface EMG.
Abstract: The rheological response of blends obtained from
quaternized polysulfone and polyvinyl alcohol in N-methyl-2-
pyrrolidone as against structural peculiarity of polymers from the
blend, composition of polymer mixtures, as well as the types of
interactions were investigated. Results show that the variation of
polyvinyl alcohol composition in the studied system determines
changes of the rheological properties, suggesting that the PVA acts as
a plasticizer. Consequently, rheological behavior of complex system,
described by the nonlinear flow curve, indicates the impact of
polyvinil alcohol content to polysulfone solution, in order to facilitate
the subsequently preparation of bioactive membranes.
Abstract: A 15-storey RC building, studied in this paper, is
representative of modern building type constructed in Madina City in
Saudi Arabia before 10 years ago. These buildings are almost
consisting of reinforced concrete skeleton i.e. columns, beams and
flat slab as well as shear walls in the stairs and elevator areas
arranged in the way to have a resistance system for lateral loads
(wind – earthquake loads). In this study, the dynamic properties of
the 15-storey RC building were identified using ambient motions
recorded at several, spatially-distributed locations within each
building. Three dimensional pushover analysis (Nonlinear static
analysis) was carried out using SAP2000 software incorporating
inelastic material properties for concrete, infill and steel. The effect
of modeling the building with and without infill walls, on the
performance point as well as capacity and demand spectra due to EQ
design spectrum function in Madina area has been investigated. ATC-
40 capacity and demand spectra are utilized to get the modification
factor (R) for the studied building. The purpose of this analysis is to
evaluate the expected performance of structural systems by
estimating, strength and deformation demands in design, and
comparing these demands to available capacities at the performance
levels of interest. The results are summarized and discussed.
Abstract: Orthogonal Frequency Division Multiplexing
(OFDM) has been used in many advanced wireless communication
systems due to its high spectral efficiency and robustness to
frequency selective fading channels. However, the major concern
with OFDM system is the high peak-to-average power ratio (PAPR)
of the transmitted signal. Some of the popular techniques used for
PAPR reduction in OFDM system are conventional partial transmit
sequences (CPTS) and clipping. In this paper, a parallel
combination/hybrid scheme of PAPR reduction using clipping and
CPTS algorithms is proposed. The proposed method intelligently
applies both the algorithms in order to reduce both PAPR as well as
computational complexity. The proposed scheme slightly degrades
bit error rate (BER) performance due to clipping operation and it can
be reduced by selecting an appropriate value of the clipping ratio
(CR). The simulation results show that the proposed algorithm
achieves significant PAPR reduction with much reduced
computational complexity.
Abstract: The beginning of 21st century has witnessed new
advancements in the design and use of new materials for biosensing
applications, from nano to macro, protein to tissue. Traditional
analytical methods lack a complete toolset to describe the
complexities introduced by living systems, pathological relations,
discrete hierarchical materials, cross-phase interactions, and
structure-property dependencies. Materiomics – via systematic
molecular dynamics (MD) simulation – can provide structureprocess-
property relations by using a materials science approach
linking mechanisms across scales and enables oriented biosensor
design. With this approach, DNA biosensors can be utilized to detect
disease biomarkers present in individuals’ breath such as acetone for
diabetes. Our wireless sensor array based on single-stranded DNA
(ssDNA)-decorated single-walled carbon nanotubes (SWNT) has
successfully detected trace amount of various chemicals in vapor
differentiated by pattern recognition. Here, we present how MD
simulation can revolutionize the way of design and screening of DNA
aptamers for targeting biomarkers related to oral diseases and oral
health monitoring. It demonstrates great potential to be utilized to
build a library of DNDA sequences for reliable detection of several
biomarkers of one specific disease, and as well provides a new
methodology of creating, designing, and applying of biosensors.
Abstract: An Energetic and exergetic analysis is conducted on a
Steam Turbine Power Plant of an existing Phosphoric Acid Factory.
The heat recovery systems used in different parts of the plant are also
considered in the analysis. Mass, thermal and exergy balances are
established on the main compounds of the factory. A numerical code
is established using EES software to perform the calculations
required for the thermal and exergy plant analysis. The effects of the
key operating parameters such as steam pressure and temperature,
mass flow rate as well as seawater temperature, on the cycle
performances are investigated. A maximum Exergy Loss Rate of about 72% is obtained for the
melters, followed by the condensers, heat exchangers and the pumps.
The heat exchangers used in the phosphoric acid unit present
exergetic efficiencies around 33% while 60% to 72% are obtained for
steam turbines and blower. For the explored ranges of HP steam
temperature and pressure, the exergy efficiencies of steam turbine
generators STGI and STGII increase of about 2.5% and 5.4%
respectively. In the same way optimum HP steam flow rate values,
leading to the maximum exergy efficiencies are defined.
Abstract: Ambient Computing or Ambient Intelligence (AmI) is
emerging area in computer science aiming to create intelligently
connected environments and Internet of Things. In this paper, we
propose communication middleware architecture for AmI. This
middleware architecture addresses problems of communication,
networking, and abstraction of applications, although there are other
aspects (e.g. HCI and Security) within general AmI framework.
Within this middleware architecture, any application developer might
address HCI and Security issues with extensibility features of this
platform.
Abstract: In language learning, second language learners as well
as Native speakers commit errors in their attempt to achieve
competence in the target language. The realm of collocation has to do
with meaning relation between lexical items. In all human language,
there is a kind of ‘natural order’ in which words are arranged or relate
to one another in sentences so much so that when a word occurs in a
given context, the related or naturally co-occurring word will
automatically come to the mind. It becomes an error, therefore, if
students inappropriately pair or arrange such ‘naturally’ co–occurring
lexical items in a text. It has been observed that most of the second
language learners in this research group commit collocation errors. A
study of this kind is very significant as it gives insight into the kinds
of errors committed by learners. This will help the language teacher
to be able to identify the sources and causes of such errors as well as
correct them thereby guiding, helping and leading the learners
towards achieving some level of competence in the language. The
aim of the study is to understand the nature of these errors as
stumbling blocks to effective essay writing. The objective of the
study is to identify the errors, analyze their structural compositions so
as to determine whether there are similarities between students in this
regard and to find out whether there are patterns to these kinds of
errors which will enable the researcher to understand their sources
and causes. As a descriptive research, the researcher samples some
nine hundred essays collected from three hundred undergraduate
learners of English as a second language in the Federal College of
Education, Kano, North- West Nigeria, i.e. three essays per each
student. The essays which were given on three different lecture times
were of similar thematic preoccupations (i.e. same topics) and length
(i.e. same number of words). The essays were written during the
lecture hour at three different lecture occasions. The errors were
identified in a systematic manner whereby errors so identified were
recorded only once even if they occur severally in students’ essays.
The data was collated using percentages in which the identified
numbers of occurrences were converted accordingly in percentages.
The findings from the study indicate that there are similarities as well
as regular and repeated errors which provided a pattern. Based on the
pattern identified, the conclusion is that students’ collocation errors
are attributable to poor teaching and learning which resulted in wrong
generalization of rules.
Abstract: The construction of most coastal infrastructure developments around the world are usually made considering wave height, current velocities and river discharges; however, little effort has been paid to surveying sediment transport during dredging or the modification to currents outside the ports or marinas during and after the construction. This study shows a complete survey during the construction of one of the largest ports of the Gulf of Mexico. An anchored Acoustic Doppler Current Velocity profiler (ADCP), a towed ADCP and a combination of model outputs were used at the Veracruz port construction in order to describe the hourly sediment transport and current modifications in and out of the new port. Owing to the stability of the system the new port was construction inside Vergara Bay, a low wave energy system with a tidal range of up to 0.40 m. The results show a two-current system pattern within the bay. The north side of the bay has an anticyclonic gyre, while the southern part of the bay shows a cyclonic gyre. Sediment transport trajectories were made every hour using the anchored ADCP, a numerical model and the weekly data obtained from the towed ADCP within the entire bay. The sediment transport trajectories were carefully tracked since the bay is surrounded by coral reef structures which are sensitive to sedimentation rate and water turbidity. The survey shows that during dredging and rock input used to build the wave breaker sediments were locally added (< 2500 m2) and local currents disperse it in less than 4 h. While the river input located in the middle of the bay and the sewer system plant may add more than 10 times this amount during a rainy day or during the tourist season. Finally, the coastal line obtained seasonally with a drone suggests that the southern part of the bay has not been modified by the construction of the new port located in the northern part of the bay, owing to the two subsystem division of the bay.
Abstract: A combined heat and power (CHP) system is an efficient and clean way to generate power (electricity). Heat produced by the CHP system can be used for water and space heating. The CHP system which uses hydrogen as fuel produces zero carbon emission. Its’ efficiency can reach more than 80% whereas that of a traditional power station can only reach up to 50% because much of the thermal energy is wasted. The other advantages of CHP systems include that they can decentralize energy generation, improve energy security and sustainability, and significantly reduce the energy cost to the users. This paper presents the economic benefits of using a CHP system in the domestic environment. For this analysis, natural gas is considered as potential fuel as the hydrogen fuel cell based CHP systems are rarely used. UK government incentives for CHP systems are also considered as the added benefit. Results show that CHP requires a significant initial investment in returns it can reduce the annual energy bill significantly. Results show that an investment may be paid back in 7 years. After the back period, CHP can run for about 3 years as most of the CHP manufacturers provide 10 year warranty.
Abstract: Energy has a prominent role for development of
nations. Countries which have energy resources also have strategic
power in the international trade of energy since it is essential for all
stages of production in the economy. Thus, it is important for
countries to analyze the weaknesses and strength of the system. On
the other side, international trade is one of the fields that are analyzed
as a complex network via network analysis. Complex network is one
of the tools to analyze complex systems with heterogeneous agents
and interaction between them. A complex network consists of nodes
and the interactions between these nodes. Total properties which
emerge as a result of these interactions are distinct from the sum of
small parts (more or less) in complex systems. Thus, standard
approaches to international trade are superficial to analyze these
systems. Network analysis provides a new approach to analyze
international trade as a network. In this network, countries constitute
nodes and trade relations (export or import) constitute edges. It
becomes possible to analyze international trade network in terms of
high degree indicators which are specific to complex networks such
as connectivity, clustering, assortativity/disassortativity, centrality,
etc. In this analysis, international trade of crude oil and coal which
are types of fossil fuel has been analyzed from 2005 to 2014 via
network analysis. First, it has been analyzed in terms of some
topological parameters such as density, transitivity, clustering etc.
Afterwards, fitness to Pareto distribution has been analyzed via
Kolmogorov-Smirnov test. Finally, weighted HITS algorithm has
been applied to the data as a centrality measure to determine the real
prominence of countries in these trade networks. Weighted HITS
algorithm is a strong tool to analyze the network by ranking countries
with regards to prominence of their trade partners. We have
calculated both an export centrality and an import centrality by
applying w-HITS algorithm to the data. As a result, impacts of the
trading countries have been presented in terms of high-degree
indicators.
Abstract: This paper explored the challenges faced by the
management of a Ghanaian state enterprise in managing conflicts and
disturbances associated with its attempt to implement new work
practices to enhance its capability to operate as a commercial entity.
The purpose was to understand the extent to which organizational
involvement, consistency and adaptability influence employees’
consumption of new work practices in transforming the
organization’s organizational activity system. Using selfadministered
questionnaires, data were collected from one hundred
and eighty (180) employees and analyzed using both descriptive and
inferential statistics. The results showed that constraints in
organizational involvement and adaptability prevented the positive
consumption of new work practices by employees in the
organization. It is also found that the organization’s employees failed
to consume the new practices being implemented, because they
perceived the process as non-involving, and as such, did not
encourage the development of employee capability, empowerment,
and teamwork. The study concluded that the failure of the
organization’s management to create opportunities for organizational
learning constrained its ability to get employees consume the new
work practices, which situation could have facilitated the
organization’s capabilities of operating as a commercial entity.
Abstract: In order to retrieve images efficiently from a large
database, a unique method integrating color and texture features
using genetic programming has been proposed. Opponent color
histogram which gives shadow, shade, and light intensity invariant
property is employed in the proposed framework for extracting color
features. For texture feature extraction, fast discrete curvelet
transform which captures more orientation information at different
scales is incorporated to represent curved like edges. The recent
scenario in the issues of image retrieval is to reduce the semantic gap
between user’s preference and low level features. To address this
concern, genetic algorithm combined with relevance feedback is
embedded to reduce semantic gap and retrieve user’s preference
images. Extensive and comparative experiments have been conducted
to evaluate proposed framework for content based image retrieval on
two databases, i.e., COIL-100 and Corel-1000. Experimental results
clearly show that the proposed system surpassed other existing
systems in terms of precision and recall. The proposed work achieves
highest performance with average precision of 88.2% on COIL-100
and 76.3% on Corel, the average recall of 69.9% on COIL and 76.3%
on Corel. Thus, the experimental results confirm that the proposed
content based image retrieval system architecture attains better
solution for image retrieval.
Abstract: The out-of-band impedance environment is considered
to be of paramount importance in engineering the in-band impedance
environment. Presenting the frequency independent and constant outof-
band impedances across the wide modulation bandwidth is
extremely important for reliable device characterization for future
wireless systems. This paper presents an out-of-band impedance
optimization scheme based on simultaneous engineering of
significant baseband components IF1 (twice the modulation
frequency) and IF2 (four times the modulation frequency) and higher
baseband components such as IF3 (six times the modulation
frequency) and IF4 (eight times the modulation frequency) to
engineer the in-band impedance environment. The investigations
were carried out on a 10W GaN HEMT device driven to deliver a
peak envelope power of approximately 40.5dBm under modulated
excitation. The presentation of frequency independent baseband
impedances to all the significant baseband components whilst
maintaining the optimum termination for fundamental tones as well
as reactive termination for 2nd harmonic under class-J mode of
operation has outlined separate optimum impedances for best
intermodulation (IM) linearity.
Abstract: The use of optical technologies in the
telecommunications has been increasing due to its ability to transmit
large amounts of data over long distances. However, as in all systems
of data transmission, optical communication channels suffer from
undesirable and non-deterministic effects, being essential to know the
same. Thus, this research allows the assessment of these effects, as
well as their characterization and beneficial uses of these effects.
Abstract: In this paper, a modified Wilkinson power divider for
GSM application is presented. The quarter–wavelength microstrip
lines in the conventional Wilkinson power divider (WPD) are
replaced by one-eighth wavelength transmission line. Wilkinson
power divider is designed using λ/4 and λ/8 transmission line. It has
the operating frequency of 915 MHz which is used in the GSM
standard. The proposed Wilkinson Power Divider is designed using
the simulation tool Advanced Design System. The results of λ/8
transmission line are very close to the results of λ/4 transmission line.
The isolation loss of λ/8 transmission line is improved by introducing
a capacitor between the output ports. The proposed Wilkinson power
divider has the best return loss of greater than -10 dB and isolation
loss of -15.25 dB. The λ/8 transmission line Wilkinson power divider
has the reduced size of 53.9 percentages than λ/4 transmission line
WPD. The proposed design has simple structure, better isolation loss
and good insertion loss.
Abstract: This paper proposes an APPLE scheme that aims at providing absolute and proportional throughput guarantees, and maximizing system throughput simultaneously for wireless LANs with homogeneous and heterogenous traffic. We formulate our objectives as an optimization problem, present its exact and approximate solutions, and prove the existence and uniqueness of the approximate solution. Simulations validate that APPLE scheme is accurate, and the approximate solution can well achieve the desired objectives already.
Abstract: The early-stage damage detection in offshore
structures requires continuous structural health monitoring and for the
large area the position of sensors will also plays an important role in
the efficient damage detection. Determining the dynamic behavior of
offshore structures requires dense deployment of sensors. The wired
Structural Health Monitoring (SHM) systems are highly expensive
and always needs larger installation space to deploy. Wireless sensor
networks can enhance the SHM system by deployment of scalable
sensor network, which consumes lesser space. This paper presents the
results of wireless sensor network based Structural Health Monitoring
method applied to a scaled experimental model of offshore structure
that underwent wave loading. This method determines the
serviceability of the offshore structure which is subjected to various
environment loads. Wired and wireless sensors were installed in the
model and the response of the scaled BLSRP model under wave
loading was recorded. The wireless system discussed in this study is
the Raspberry pi board with Arm V6 processor which is programmed
to transmit the data acquired by the sensor to the server using Wi-Fi
adapter, the data is then hosted in the webpage. The data acquired
from the wireless and wired SHM systems were compared and the
design of the wireless system is verified.
Abstract: Multiple Sclerosis (MS) is a disease which affects the
central nervous system and causes balance problem. In clinical, this
disorder is usually evaluated using static posturography. Some linear
or nonlinear measures, extracted from the posturographic data (i.e.
center of pressure, COP) recorded during a balance test, has been
used to analyze postural control of MS patients. In this study, the
trend (TREND) and the sample entropy (SampEn), two nonlinear
parameters were chosen to investigate their relationships with the
expanded disability status scale (EDSS) score. 40 volunteers with
different EDSS scores participated in our experiments with eyes open
(EO) and closed (EC). TREND and 2 types of SampEn (SampEn1
and SampEn2) were calculated for each combined COP’s position
signal. The results have shown that TREND had a weak negative
correlation to EDSS while SampEn2 had a strong positive correlation
to EDSS. Compared to TREND and SampEn1, SampEn2 showed a
better significant correlation to EDSS and an ability to discriminate
the MS patients in the EC case. In addition, the outcome of the study
suggests that the multi-dimensional nonlinear analysis could provide
some information about the impact of disability progression in MS on
dynamics of the COP data.