Abstract: Droplet size distributions in the cold spray of a fuel
are important in observed combustion behavior. Specification of
droplet size and velocity distributions in the immediate downstream
of injectors is also essential as boundary conditions for advanced
computational fluid dynamics (CFD) and two-phase spray transport
calculations. This paper describes the development of a new model to
be incorporated into maximum entropy principle (MEP) formalism
for prediction of droplet size distribution in droplet formation region.
The MEP approach can predict the most likely droplet size and
velocity distributions under a set of constraints expressing the
available information related to the distribution.
In this article, by considering the mechanisms of turbulence
generation inside the nozzle and wave growth on jet surface, it is
attempted to provide a logical framework coupling the flow inside the
nozzle to the resulting atomization process. The purpose of this paper
is to describe the formulation of this new model and to incorporate it
into the maximum entropy principle (MEP) by coupling sub-models
together using source terms of momentum and energy. Comparison
between the model prediction and experimental data for a gas turbine
swirling nozzle and an annular spray indicate good agreement
between model and experiment.
Abstract: This paper presents the effect of driving a motor
vehicle on the stress levels of older drivers, indicated by monitoring
their hear rate increase whilst completing various everyday driving
tasks. Results suggest that whilst older female drivers heart rate varied
more significantly than males, the actual age of a participant did not
result in a significant change in heart rate due to stress, within the age
group tested. The analysis of the results indicates the most stressful
manoeuvres undertaken by the older drivers and highlights the tasks
which were found difficult with a view to implementing technologies
to aid the more senior driver in automotive travel.
Abstract: SeqWord Gene Island Sniffer, a new program for
the identification of mobile genetic elements in sequences of bacterial chromosomes is presented. This program is based on the
analysis of oligonucleotide usage variations in DNA sequences. 3,518 mobile genetic elements were identified in 637 bacterial
genomes and further analyzed by sequence similarity and the
functionality of encoded proteins. The results of this study are stored in an open database http://anjie.bi.up.ac.za/geidb/geidbhome.
php). The developed computer program and the database provide the information valuable for further investigation of the
distribution of mobile genetic elements and virulence factors among bacteria. The program is available for download at www.bi.up.ac.za/SeqWord/sniffer/index.html.
Abstract: This paper presents a hybrid electric scooter model developed and simulated using Matlab/Simulink. This hybrid scooter modeled has a parallel hybrid structure. The main propulsion units consist of a two stroke internal combustion engine and a hub motor attached to the front wheel of the scooter. The methodology used to optimize the energy and fuel consumption of the hybrid electric scooter is the multi-mode approach. Various case studies were presented to check the model and were compared to the literatures. Results shown that the model developed was feasible and valuable.
Abstract: We report in this paper the model adopted by our
system of continuous speech recognition in Arab language SySRA
and the results obtained until now. This system uses the database
Arabdic-10 which is a corpus of word for the Arab language and
which was manually segmented. Phonetic decoding is represented
by an expert system where the knowledge base is translated in the
form of production rules. This expert system transforms a vocal
signal into a phonetic lattice. The higher level of the system takes
care of the recognition of the lattice thus obtained by deferring it in
the form of written sentences (orthographical Form). This level
contains initially the lexical analyzer which is not other than the
module of recognition. We subjected this analyzer to a set of
spectrograms obtained by dictating a score of sentences in Arab
language. The rate of recognition of these sentences is about 70%
which is, to our knowledge, the best result for the recognition of the
Arab language. The test set consists of twenty sentences from four
speakers not having taken part in the training.
Abstract: In this paper we promote the Ultra Low Voltage (ULV) NAND gate to replace either partly or entirely the encryption block of a design to withstand power analysis attack.
Abstract: We theoretically investigate the effects of frequency
detuning and injection power on the nonlinear dynamics of DFB
lasers under dual external optical injection.
Abstract: The importance of good requirements engineering is well documented. Agile practices, promoting collaboration and communications, facilitate the elicitation and management of volatile requirements. However, current Agile practices work in a well-defined environment. It is necessary to have a co-located customer. With distributed development it is not always possible to realize this co-location. In this environment a suitable process, possibly supported by tools, is required to support changing requirements. This paper introduces the issues of concern when managing requirements in a distributed environment and describes work done at the Software Technology Research Centre as part of the NOMAD project.
Abstract: In this paper, penalized power-divergence test statistics have been defined and their exact size properties to test a nested sequence of log-linear models have been compared with ordinary power-divergence test statistics for various penalization, λ and main effect values. Since the ordinary and penalized power-divergence test statistics have the same asymptotic distribution, comparisons have been only made for small and moderate samples. Three-way contingency tables distributed according to a multinomial distribution have been considered. Simulation results reveal that penalized power-divergence test statistics perform much better than their ordinary counterparts.
Abstract: A passive system "Qanat" is collection of some
underground wells. A mother-well was dug in a place far from the
city where they could reach to the water table maybe 100 meters
underground, they dug other wells to direct water toward the city,
with minimum possible gradient. Using the slope of the earth they
could bring water close to the surface in the city. The source of water
or the appearance of Qanat, land slope and the ownership lines are
the important and effective factors in the formation of routes and the
segment division of lands to the extent that making use of Qanat as
the techniques of extracting underground waters creates a channel of
routes with an organic order and hierarchy coinciding the slope of
land and it also guides the Qanat waters in the tradition texture of salt
desert and border provinces of it. Qanats are excavated in a specified
distinction from each other. The quantity of water provided by
Qanats depends on the kind of land, distance from mountain,
geographical situation of them and the rate of water supply from the
underground land. The rate of underground waters, possibility of
Qanat excavation, number of Qanats and rate of their water supply
from one hand and the quantity of cultivable fertile lands from the
other hand are the important natural factors making the size of cities.
In the same manner the cities with several Qanats have multi central
textures. The location of cities is in direct relation with land quality,
soil fertility and possibility of using underground water by excavating
Qanats. Observing the allowable distance for Qanat watering is a
determining factor for distance between villages and cities.
Topography, land slope, soil quality, watering system, ownership,
kind of cultivation, etc. are the effective factors in directing Qanats
for excavation and guiding water toward the cultivable lands and it
also causes the formation of different textures in land division of
farming provinces. Several divisions such as orderly and wide, inorderly,
thin and long, comb like, etc. are the introduction to organic
order. And at the same time they are complete coincidence with
environmental conditions in the typical development of ecological
architecture and planning in the traditional cities and settlements
order.
Abstract: This study aims to segment objects using the K-means
algorithm for texture features. Firstly, the algorithm transforms color
images into gray images. This paper describes a novel technique for
the extraction of texture features in an image. Then, in a group of
similar features, objects and backgrounds are differentiated by using
the K-means algorithm. Finally, this paper proposes a new object
segmentation algorithm using the morphological technique. The
experiments described include the segmentation of single and multiple
objects featured in this paper. The region of an object can be
accurately segmented out. The results can help to perform image
retrieval and analyze features of an object, as are shown in this paper.
Abstract: In this paper, a novel scheme is proposed for ownership identification and authentication using color images by deploying Cryptography and Digital Watermarking as underlaying technologies. The former is used to compute the contents based hash and the latter to embed the watermark. The host image that will claim to be the rightful owner is first transformed from RGB to YST color space exclusively designed for watermarking based applications. Geometrically YS ÔèÑ T and T channel corresponds to the chrominance component of color image, therefore suitable for embedding the watermark. The T channel is divided into 4×4 nonoverlapping blocks. The size of block is important for enhanced localization, security and low computation. Each block along with ownership information is then deployed by SHA160, a one way hash function to compute the content based hash, which is always unique and resistant against birthday attack instead of using MD5 that may raise the condition i.e. H(m)=H(m'). The watermark payload varies from block to block and computed by the variance factorα . The quality of watermarked images is quite high both subjectively and objectively. Our scheme is blind, computationally fast and exactly locates the tampered region.
Abstract: In this research, we study a control method of a multivehicle
system while considering the limitation of communication
range for each vehicles. When we control networked vehicles with
limitation of communication range, it is important to control the
communication network structure of a multi-vehicle system in order
to keep the network-s connectivity. From this, we especially aim to
control the network structure to the target structure. We formulate
the networked multi-vehicle system with some disturbance and the
communication constraints as a hybrid dynamical system, and then
we study the optimal control problems of the system. It is shown
that the system converge to the objective network structure in finite
time when the system is controlled by the receding horizon method.
Additionally, the optimal control probrems are convertible into the
mixed integer problems and these problems are solvable by some
branch and bound algorithm.
Abstract: Recent developments in Soft computing techniques,
power electronic switches and low-cost computational hardware have
made it possible to design and implement sophisticated control
strategies for sensorless speed control of AC motor drives. Such an
attempt has been made in this work, for Sensorless Speed Control of
Induction Motor (IM) by means of Direct Torque Fuzzy Control
(DTFC), PI-type fuzzy speed regulator and MRAS speed estimator
strategy, which is absolutely nonlinear in its nature. Direct torque
control is known to produce quick and robust response in AC drive
system. However, during steady state, torque, flux and current ripple
occurs. So, the performance of conventional DTC with PI speed
regulator can be improved by implementing fuzzy logic techniques.
Certain important issues in design including the space vector
modulated (SVM) 3-Ф voltage source inverter, DTFC design,
generation of reference torque using PI-type fuzzy speed regulator
and sensor less speed estimator have been resolved. The proposed
scheme is validated through extensive numerical simulations on
MATLAB. The simulated results indicate the sensor less speed
control of IM with DTFC and PI-type fuzzy speed regulator provides
satisfactory high dynamic and static performance compare to
conventional DTC with PI speed regulator.
Abstract: In this work social stratification is considered as one
of significant factor which generate the phenomena “terrorism” and it
puts the accent on correlation connection between them, with the
object of creation info-logical model generation of phenomena of
“terrorism” based on stratification process.
Abstract: Agricultural residue such as oil palm fronds (OPF) is
cheap, widespread and available throughout the year. Hemicelluloses
extracted from OPF can be hydrolyzed to their monomers and used in
production of xylooligosaccharides (XOs). The objective of the
present study was to optimize the enzymatic hydrolysis process of
OPF hemicellulose by varying pH, temperature, enzyme and substrate
concentration for production of XOs. Hemicelluloses was extracted
from OPF by using 3 M potassium hydroxide (KOH) at temperature of
40°C for 4 hrs and stirred at 400 rpm. The hemicellulose was then
hydrolyzed using Trichoderma longibrachiatum xylanase at different
pH, temperature, enzyme and substrate concentration. XOs were
characterized based on reducing sugar determination. The optimum
conditions to produced XOs from OPF hemicellulose was obtained at
pH 4.6, temperature of 40°C , enzyme concentration of 2 U/mL and
2% substrate concentration. The results established the suitability of
oil palm fronds as raw material for production of XOs.
Abstract: The coastal sediments of West Port of Malaysia was monitored from Nov. 2009 to Oct. 2010 to assess spatial distribution of heavy metals As, Cu, Cd, Cr, Hg, Ni, Zn and Pb. Sediment samples were collected from 10 stations in dry and rainy season in West Port. The range concentrations measured (Mg/g dry weight ) were from 23.4 to 98.3 for Zn, 22.3 to 80 for Pb, 7.4 to 27.6 Cu, 0.244 to 3.53 for Cd, 7.2 to 22.2 for Ni, 20.2 to 162 for As, 0.11 to 0.409 for Hg and 11.5 to 61.5 for Cr. The geochemical indexes used in this study were Geoaccumulation (Igeo), Contamination Factor (CF) and Pollution Load Index (PLI); these indexes were used to evaluate the levels of sediment contaminations. The results of these indexes show that, the status of West Port sediment quality are moderately polluted by heavy metals except in arsenic which shows the high level of pollution.
Abstract: Ranked set sampling (RSS) was first suggested to increase the efficiency of the population mean. It has been shown that this method is highly beneficial to the estimation based on simple random sampling (SRS). There has been considerable development and many modifications were done on this method. When a concomitant variable is available, ratio estimation based on ranked set sampling was proposed. This ratio estimator is more efficient than that based on SRS. In this paper some ratio type estimators of the population mean based on RSS are suggested. These estimators are found to be more efficient than the estimators of similar form using simple random sample.
Abstract: The purpose of this study is to discuss the effect of the
intervention of exercise behavior change plan for high school students
on study subjects- social and psychological factors and exercise
stages. This research uses the transtheoretical model as the research
framework. One experiment group and one control group were used in
a quasi-experimental design research. The experimental group
accepted health-related physical fitness course and the traditional
course; the control group accepted traditional physical education
course. There is a significant difference before and after the
intervention in the experimental group. Karl-s test shows the
experimental group gained a better improvement than that in the
control group. The Analysis of Covariance had shown the exercise
stages (F=7.62, p
Abstract: The present paper represent the efforts undertaken for
the development of an semi-automatic robot that may be used for
various post-disaster rescue operation planning and their subsequent
execution using one-way communication of video and data from the
robot to the controller and controller to the robot respectively.
Wireless communication has been used for the purpose so that the
robot may access the unapproachable places easily without any
difficulties. It is expected that the information obtained from the
robot would be of definite help to the rescue team for better planning
and execution of their operations.