Abstract: This paper undertakes the problem of optimal
capacitor placement in a distribution system. The problem is how to
optimally determine the locations to install capacitors, the types and
sizes of capacitors to he installed and, during each load level,the
control settings of these capacitors in order that a desired objective
function is minimized while the load constraints,network constraints
and operational constraints (e.g. voltage profile) at different load
levels are satisfied. The problem is formulated as a combinatorial
optimization problem with a nondifferentiable objective function.
Four solution mythologies based on algorithms (GA),tabu search
(TS), and hybrid GA-SA algorithms are presented.The solution
methodologies are preceded by a sensitivity analysis to select the
candidate capacitor installation locations.
Abstract: Connected dominating set (CDS) problem in unit disk
graph has signi£cant impact on an ef£cient design of routing protocols
in wireless sensor networks, where the searching space for a
route is reduced to nodes in the set. A set is dominating if all the
nodes in the system are either in the set or neighbors of nodes in the
set. In this paper, a simple and ef£cient heuristic method is proposed
for £nding a minimum connected dominating set (MCDS) in ad hoc
wireless networks based on the new parameter support of vertices.
With this parameter the proposed heuristic approach effectively
£nds the MCDS of a graph. Extensive computational experiments
show that the proposed approach outperforms the recently proposed
heuristics found in the literature for the MCD
Abstract: The effect of cassava root ensiled with cassava top or
legumes on voluntary feed intake and milk production were
determined in 12 dairy cows using a 4×3 change-over design.
Experimental period were 30 days long and consisted of 14 days of
adaptation. Silage was prepared from cassava root mixed with
cassava top or legumes at ratio 60:40. Cows were allotted at random
to receive ad libitum one of four rations: T1) control, T2) cassava
root +cassava top-silages, T3) cassava root +hamata - silages and T4)
cassava root +Thapra stylo-silages.
The dry matter intake (BW0.75) was higher (P< 0.05) in cow fed
with silages diets compared with T1. However, the intake of T2 was
higher among treatments. Milk production was lowest in cow fed
with T1. Among silages based diets, milk production was not
significantly different but 4%FCM was higher in cow fed T2. Milk
compositions were not affected by feeding diets.
It is concluded that feeding cassava root ensiled with its leaves as
a supplement increased dry matter intake and significantly improved
4%FCM. The combination of cassava root and legume silages did not
improve the feed intake but did increase the milk production.
Abstract: In this paper, a mathematical model is proposed to
estimate the dropping probabilities of cellular wireless networks by
queuing handoff instead of reserving guard channels. Usually, prioritized
handling of handoff calls is done with the help of guard channel
reservation. To evaluate the proposed model, gamma inter-arrival and
general service time distributions have been considered. Prevention of
some of the attempted calls from reaching to the switching center due
to electromagnetic propagation failure or whimsical user behaviour
(missed call, prepaid balance etc.), make the inter-arrival time of
the input traffic to follow gamma distribution. The performance is
evaluated and compared with that of guard channel scheme.
Abstract: Voltage flicker is a disturbance in electrical power
systems. The reason for this disturbance is mainly the large nonlinear
loads such as electric arc furnaces. Synchronous static
compensator (STATCOM) is considered as a proper technique to
mitigate the voltage flicker. Application of more suitable and precise
power electronic converter leads to a more precise performance of the
compensator. In this paper a three-level 12-pulse voltage source
inverter (VSI) with a 12-terminal transformer connected to the ac
system is studied and the obtained results are compared with the
performance of a STATCOM using a simple two-level VSI and an
optimal and more precise performance of the proposed scheme is
achieved.
Abstract: Standards for learning objects focus primarily on
content presentation. They were already extended to support automatic evaluation but it is limited to exercises with a predefined
set of answers. The existing standards lack the metadata required by specialized evaluators to handle types of exercises with an indefinite
set of solutions. To address this issue existing learning object standards were extended to the particular requirements of a
specialized domain. A definition of programming problems as learning objects, compatible both with Learning Management Systems and with systems performing automatic evaluation of
programs, is presented in this paper. The proposed definition includes
metadata that cannot be conveniently represented using existing standards, such as: the type of automatic evaluation; the requirements
of the evaluation engine; and the roles of different assets - tests cases, program solutions, etc. The EduJudge project and its main services
are also presented as a case study on the use of the proposed definition of programming problems as learning objects.
Abstract: This paper proposes an efficient lattice-reduction-aided
detection (LRD) scheme to improve the detection performance of
MIMO-OFDM system. In this proposed scheme, V candidate symbols
are considered at the first layer, and V probable streams are
detected with LRD scheme according to the first detected V candidate
symbols. Then, the most probable stream is selected through a ML
test. Since the proposed scheme can more accurately detect initial
symbol and can reduce transmission of error to rest symbols, the
proposed scheme shows more improved performance than conventional
LRD with very low complexity.
Abstract: Beam and diffuse radiation data are extracted analytically from previous measured data on a horizontal surface in Zarqa city. Moreover, radiation data on a tilted surfaces with different slopes have been derived and analyzed. These data are consisting of of beam contribution, diffuse contribution, and ground reflected contribution radiation. Hourly radiation data for horizontal surface possess the highest radiation values on June, and then the values decay as the slope increases and the sharp decreasing happened for vertical surface. The beam radiation on a horizontal surface owns the highest values comparing to diffuse radiation for all days of June. The total daily radiation on the tilted surface decreases with slopes. The beam radiation data also decays with slopes especially for vertical surface. Diffuse radiation slightly decreases with slopes with sharp decreases for vertical surface. The groundreflected radiation grows with slopes especially for vertical surface. It-s clear that in June the highest harvesting of solar energy occurred for horizontal surface, then the harvesting decreases as the slope increases.
Abstract: In this paper we propose a framework for
multisensor intrusion detection called Fuzzy Agent-Based Intrusion
Detection System. A unique feature of this model is that the agent
uses data from multiple sensors and the fuzzy logic to process log
files. Use of this feature reduces the overhead in a distributed
intrusion detection system. We have developed an agent
communication architecture that provides a prototype
implementation. This paper discusses also the issues of combining
intelligent agent technology with the intrusion detection domain.
Abstract: High voltage generators are being subject to higher
voltage rating and are being designed to operate in harsh conditions.
Stator windings are the main component of generators in which
Electrical, magnetically and thermal stresses remain major failures
for insulation degradation accelerated aging. A large number of
generators failed due to stator winding problems, mainly insulation
deterioration. Insulation degradation assessment plays vital role in the
asset life management. Mostly the stator failure is catastrophic
causing significant damage to the plant. Other than generation loss,
stator failure involves heavy repair or replacement cost. Electro
thermal analysis is the main characteristic for improvement design of
stator slot-s insulation. Dielectric parameters such as insulation
thickness, spacing, material types, geometry of winding and slot are
major design consideration. A very powerful method available to
analyze electro thermal performance is Finite Element Method
(FEM) which is used in this paper. The analysis of various stator coil
and slot configurations are used to design the better dielectric system
to reduce electrical and thermal stresses in order to increase the
power of generator in the same volume of core. This paper describes
the process used to perform classical design and improvement
analysis of stator slot-s insulation.
Abstract: In general, class complexity is measured based on any
one of these factors such as Line of Codes (LOC), Functional points
(FP), Number of Methods (NOM), Number of Attributes (NOA) and so on. There are several new techniques, methods and metrics with
the different factors that are to be developed by the researchers for calculating the complexity of the class in Object Oriented (OO)
software. Earlier, Arockiam et.al has proposed a new complexity measure namely Extended Weighted Class Complexity (EWCC)
which is an extension of Weighted Class Complexity which is proposed by Mishra et.al. EWCC is the sum of cognitive weights of
attributes and methods of the class and that of the classes derived. In EWCC, a cognitive weight of each attribute is considered to be 1.
The main problem in EWCC metric is that, every attribute holds the
same value but in general, cognitive load in understanding the
different types of attributes cannot be the same. So here, we are proposing a new metric namely Attribute Weighted Class Complexity
(AWCC). In AWCC, the cognitive weights have to be assigned for the attributes which are derived from the effort needed to understand
their data types. The proposed metric has been proved to be a better
measure of complexity of class with attributes through the case studies and experiments
Abstract: The recurring decimal of rural and urban poverty in
Nigeria, resulting from lack of sustainable livelihood activities by
the people due to non-diversification of the economy, necessitated
this study. One hundred snail farmers were randomly selected in
Akure North and Akure South Local Government areas of Ondo
State, Southwest Nigeria where snail farming is widely practised.
Data collection was through questionnaires administration and onsite
observation of farms. Data obtained were subjected to
descriptive statistics, Student-s t-test and regression analysis. Cost
benefit ratio (CBR) and rate of return on investment (RORI) were
calculated in order to determine the poverty alleviation potentials of
snail farming in the study areas. Although snail farming was
profitable and viable, it was below poverty line. With time and more
knowledge in its farming activities, and with more people taking to
snail production, its poverty alleviation and reduction potentials will
increase.
Abstract: The research study is carried out to determine the efficiency of the Biofilm sewage treatment plant which is located at the Engineering Complex-s. Wastewater analyses have been carried out at the Environmental Engineering laboratory to study the six parameters: Biochemical Oxygen Demand BOD, Chemical Oxygen Demand COD l, and Total Suspended Solids TSS, Ammoniac Nitrogen NH3-N and Phosphorous P which have been selected to determine the wastewater quality. The plant was designed to treat 750 Pe (population equivalent) at hydraulic retention time of 5 hours in the aerobic zone. The results show that Biofilm wastewater treatment plant was able to treat sewage successfully at different flow condition. The discharge has fulfilled the Malaysia Environmental of Standard A water quality. The achieved BOD removal is more than 85%, COD is more than 80%, TSS is more than 80%, NH3-N is more than 70%, and P was more than 70%. The Biofilm system provides a very efficient process for sewage treatment and it is compact in structure thus minimizes the required land area.
Abstract: Commercial nanocomposite food packaging type nano-silver containers were characterised using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The presence of nanoparticles consistent with the incorporation of 1% nano-silver (Ag) and 0.1% titanium dioxide (TiO2) nanoparticle into polymeric materials formed into food containers was confirmed. Both nanomaterials used in this type of packaging appear to be embedded in a layered configuration within the bulk polymer. The dimensions of the incorporated nanoparticles were investigated using X-ray diffraction (XRD) and determined by calculation using the Scherrer Formula; these were consistent with Ag and TiO2 nanoparticles in the size range 20-70nm both were spherical shape nanoparticles. Antimicrobial assessment of the nanocomposite container has also been performed and the results confirm the antimicrobial activity of Ag and TiO2 nanoparticles in food packaging containers. Migration assessments were performed in a wide range of food matrices to determine the migration of nanoparticles from the packages. The analysis was based upon the relevant European safety Directives and involved the application of inductively coupled plasma mass spectrometry (ICP-MS) to identify the range of migration risk. The data pertain to insignificance levels of migration of Ag and TiO2 nanoparticles into the selected food matrices.
Abstract: In vitro plant regeneration has been successfully obtained from basal shoot explant of Vetiveria zizanioides through indirect organogenesis. The explant was cultured in Murashige & Skoog’s (MS) media supplemented with 2,4-D, IAA, and kinetin in various concentrations. Callus was well induced in media supplemented with 2 ppm 2,4-D, 1 ppm IAA, and 1 ppm kinetin. This callus was then transferred to MS media supplemented with 1 - 5 ppm of BAP for shoot regeneration. The media supplemented with 3 ppm BAP was a suitable medium for shoot induction, as well as for shoot multiplication. Rooting was well developed in shoot following transferred to half MS media containing 0.2 ppm IBA. Plantlet was then transferred to husk charcoal for acclimatization, and almost all (90%) of plantlets were survived during acclimatization.
Abstract: This paper presents the exergy analysis of a
desalination unit using humidification-dehumidification process.
Here, this unit is considered as a thermal system with three main
components, which are the heating unit by using a solar collector, the
evaporator or the humidifier, and the condenser or the dehumidifier.
In these components the exergy is a measure of the quality or grade
of energy and it can be destroyed in them. According to the second
law of thermodynamics this destroyed part is due to irreversibilities
which must be determined to obtain the exergetic efficiency of the
system.
In the current paper a computer program has been developed using
visual basic to determine the exergy destruction and the exergetic
efficiencies of the components of the desalination unit at variable
operation conditions such as feed water temperature, outlet air
temperature, air to feed water mass ratio and salinity, in addition to
cooling water mass flow rate and inlet temperature, as well as
quantity of solar irradiance.
The results obtained indicate that the exergy efficiency of the
humidifier increases by increasing the mass ratio and decreasing the
outlet air temperature. In the other hand the exergy efficiency of the
condenser increases with the increase of this ratio and also with the
increase of the outlet air temperature.
Abstract: In this paper, experimental testing and numerical analysis were used to investigate the effect of tube thickness on the face bending for concrete filled hollow sections connected to other structural members using Extended Hollobolts. Six samples were tested experimentally by applying pull-out load on the bolts. These samples were designed to fail by column face bending. The main variable in all tests is the column face thickness. Finite element analyses were also performed using ABAQUS 6.11 to extend the experimental results and to quantify the effect of column face thickness. Results show that, the column face thickness has a clear impact on the connection strength and stiffness. However, the amount of improvement in the connection stiffness by changing the column face thickness from 5mm to 6.3mm seems to be higher than that when increasing it from 6.3mm to 8mm. The displacement at which the bolts start pulling-out from their holes increased with the use of thinner column face due to the high flexibility of the section. At the ultimate strength, the yielding of the column face propagated to the column corner and there was no yielding in its walls. After the ultimate resistance is reached, the propagation of the yielding was mainly in the column face with a miner yielding in the walls.
Abstract: A full six degrees of freedom (6-DOF) flight dynamics
model is proposed for the accurate prediction of short and long-range
trajectories of high spin and fin-stabilized projectiles via atmospheric
flight to final impact point. The projectiles is assumed to be both rigid
(non-flexible), and rotationally symmetric about its spin axis launched
at low and high pitch angles. The mathematical model is based on the
full equations of motion set up in the no-roll body reference frame and
is integrated numerically from given initial conditions at the firing
site. The projectiles maneuvering motion depends on the most
significant force and moment variations, in addition to wind and
gravity. The computational flight analysis takes into consideration the
Mach number and total angle of attack effects by means of the
variable aerodynamic coefficients. For the purposes of the present
work, linear interpolation has been applied from the tabulated database
of McCoy-s book. The developed computational method gives
satisfactory agreement with published data of verified experiments and
computational codes on atmospheric projectile trajectory analysis for
various initial firing flight conditions.
Abstract: Electrocardiogram (ECG) data compression algorithm
is needed that will reduce the amount of data to be transmitted, stored
and analyzed, but without losing the clinical information content. A
wavelet ECG data codec based on the Set Partitioning In Hierarchical
Trees (SPIHT) compression algorithm is proposed in this paper. The
SPIHT algorithm has achieved notable success in still image coding.
We modified the algorithm for the one-dimensional (1-D) case and
applied it to compression of ECG data.
By this compression method, small percent root mean square
difference (PRD) and high compression ratio with low
implementation complexity are achieved. Experiments on selected
records from the MIT-BIH arrhythmia database revealed that the
proposed codec is significantly more efficient in compression and in
computation than previously proposed ECG compression schemes.
Compression ratios of up to 48:1 for ECG signals lead to acceptable
results for visual inspection.
Abstract: It is a challenge to provide a wide range of queries to
database query systems for small mobile devices, such as the PDAs
and cell phones. Currently, due to the physical and resource
limitations of these devices, most reported database querying systems
developed for them are only offering a small set of pre-determined
queries for users to possibly pose. The above can be resolved by
allowing free-form queries to be entered on the devices. Hence, a
query language that does not restrict the combination of query terms
entered by users is proposed. This paper presents the free-form query
language and the method used in translating free-form queries to
their equivalent SQL statements.