Abstract: The information revealed by derivatives can help to
better characterize digital near-end crosstalk signatures with the
ultimate goal of identifying the specific aggressor signal.
Unfortunately, derivatives tend to be very sensitive to even low
levels of noise. In this work we approximated the derivatives of both
quiet and noisy digital signals using a wavelet-based technique. The
results are presented for Gaussian digital edges, IBIS Model digital
edges, and digital edges in oscilloscope data captured from an actual
printed circuit board. Tradeoffs between accuracy and noise
immunity are presented. The results show that the wavelet technique
can produce first derivative approximations that are accurate to
within 5% or better, even under noisy conditions. The wavelet
technique can be used to calculate the derivative of a digital signal
edge when conventional methods fail.
Abstract: This paper presents an innovative approach within the area of Group Decision Support System (GDSS) by using tools based on intelligent agents. It introduces iGDSS, a software platform for decision support and collaboration and an application of this platform - eCollaborative Decisions - for academic environment, all these developed within a framework of a research project.
Abstract: This work proposes a recursive weighted ELS
algorithm for system identification by applying numerically robust
orthogonal Householder transformations. The properties of the
proposed algorithm show it obtains acceptable results in a noisy
environment: fast convergence and asymptotically unbiased
estimates. Comparative analysis with others robust methods well
known from literature are also presented.
Abstract: Renewed interest in propeller propulsion on aircraft
configurations combined with higher propeller loads lead to the question how the effects of the propulsion on model support disturbances
should be accounted for. In this paper, the determination of engine power effects on support interference of sting-mounted models is
demonstrated by a measurement on a four-engine turboprop aircraft.
CFD results on a more generic model are presented in order to clarify
the possible mechanism behind engine power effects on support
interference. The engine slipstream induces a local change in angle
of sideslip at the model sting thereby influencing the sting near-field and far-field effects. Whether or not the net result of these changes
in the disturbance pattern leads to a significant engine power effect depends on the configuration of the wind tunnel model and the test
setup.
Abstract: The indistinctness of the manufacturing processes makes that a parts cannot be realized in an absolutely exact way towards the specifications on the dimensions. It is thus necessary to assume that the effectively realized product has to belong in a very strict way to compatible intervals with a correct functioning of the parts. In this paper we present an approach based on mixing tow different characteristics theories, the fuzzy system and Petri net system. This tool has been proposed to model and control the quality in an assembly system. A robust command of a mechanical assembly process is presented as an application. This command will then have to maintain the specifications interval of parts in front of the variations. It also illustrates how the technique reacts when the product quality is high, medium, or low.
Abstract: In hydrocyclones, the particle separation efficiency is
limited by the suspended fine particles, which are discharged with the
coarse product in the underflow. It is well known that injecting water
in the conical part of the cyclone reduces the fine particle fraction in
the underflow. This paper presents a mathematical model that
simulates the water injection in the conical component. The model
accounts for the fluid flow and the particle motion. Particle
interaction, due to hindered settling caused by increased density and
viscosity of the suspension, and fine particle entrainment by settling
coarse particles are included in the model. Water injection in the
conical part of the hydrocyclone is performed to reduce fine particle
discharge in the underflow. The model demonstrates the impact of
the injection rate, injection velocity, and injection location on the
shape of the partition curve. The simulations are compared with
experimental data of a 50-mm cyclone.
Abstract: The fast growing accessibility and capability of emerging technologies have fashioned enormous possibilities of designing, developing and implementing innovative teaching methods in the classroom. The global technological scenario has paved the way to new pedagogies in teaching-learning process focusing on technology based learning environment and its impact on student achievement. The present experimental study was conducted to determine the effectiveness of technology based learning environment on student achievement in English as a foreign language. The sample of the study was 90 students of 10th grade of a public school located in Islamabad. A pretest- posttest equivalent group design was used to compare the achievement of the two groups. A Pretest and A posttest containing 50 items each from English textbook were developed and administered. The collected data were statistically analyzed. The results showed that there was a significant difference between the mean scores of Experimental group and the Control group. The performance of Experimental group was better on posttest scores that indicted that teaching through technology based learning environment enhanced the achievement level of the students. On the basis of the results, it was recommended that teaching and learning through information and communication technologies may be adopted to enhance the language learning capability of the students.
Abstract: Study was conducted to determine the concentration of
copper, cadmium, lead and zinc in Cabomba furcata that found
abundance in Lake Chini. This aquatic plant was collected randomly
within the lake for heavy metal determination. Water quality
measurement was undertaken in situ for temperature, pH,
conductivity and dissolved oksigen using portable multi sensor probe
YSI model 556. The C. furcata was digested using wet digestion
method and heavy metal concentrations were analysed using Atomic
Absorption Spectrometer (AAS) Perkin Elmer 4100B (flame
method). Result of water quality classify Lake Chini between class II
to class III using Malaysian Water Quality Standard. According to
this standard, Lake Chini has moderate quality, which normal for
natural lake. Heavy metal concentrations in C.furcata were low and
found to be lower than the critical toxic value in aquatic plants. Oneway
ANOVA test indicated the heavy metal concentrations in
C.furcata were significantly differ between sampling location. Water
quality and heavy metal concentrations indicates that Lake Chini was
not receives anthropogenic load from nearby activities.
Abstract: Clustering is a very well known technique in data mining. One of the most widely used clustering techniques is the k-means algorithm. Solutions obtained from this technique are dependent on the initialization of cluster centers. In this article we propose a new algorithm to initialize the clusters. The proposed algorithm is based on finding a set of medians extracted from a dimension with maximum variance. The algorithm has been applied to different data sets and good results are obtained.
Abstract: With the fast evolution of digital data exchange, security information becomes much important in data storage and transmission. Due to the increasing use of images in industrial process, it is essential to protect the confidential image data from unauthorized access. In this paper, we analyze the Advanced Encryption Standard (AES), and we add a key stream generator (A5/1, W7) to AES to ensure improving the encryption performance; mainly for images characterised by reduced entropy. The implementation of both techniques has been realized for experimental purposes. Detailed results in terms of security analysis and implementation are given. Comparative study with traditional encryption algorithms is shown the superiority of the modified algorithm.
Abstract: Vacuum membrane distillation (VMD) process can be
used for water purification or the desalination of salt water. The
process simply consists of a flat sheet hydrophobic micro porous
PTFE membrane and diaphragm vacuum pump without a condenser
for the water recovery or trap. The feed was used aqueous NaCl
solution. The VMD experiments were performed to evaluate the heat
and mass transfer coefficient of the boundary layer in a membrane
module. The only operating parameters are feed inlet temperature,
and feed flow rate were investigated. The permeate flux was strongly
affected by the feed inlet temperature, feed flow rate, and boundary
layer heat transfer coefficient. Since lowering the temperature
polarization coefficient is essential enhance the process performance
considerable and maximizing the heat transfer coefficient for
maximizes the mass flux of distillate water. In this paper, the results
of VMD experiments are used to measure the boundary layer heat
transfer coefficient, and the experimental results are used to reevaluate
the empirical constants in the Dittus- Boelter equation.
Abstract: The value of overall oxygen transfer Coefficient
(KLa), which is the best measure of oxygen transfer in water through
aeration, is obtained by a simple approach, which sufficiently
explains the utility of the method to eliminate the discrepancies due
to inaccurate assumption of saturation dissolved oxygen
concentration. The rate of oxygen transfer depends on number of
factors like intensity of turbulence, which in turns depends on the
speed of rotation, size, and number of blades, diameter and
immersion depth of the rotor, and size and shape of aeration tank, as
well as on physical, chemical, and biological characteristic of water.
An attempt is made in this paper to correlate the overall oxygen
transfer Coefficient (KLa), as an independent parameter with other
influencing parameters mentioned above. It has been estimated that
the simulation equation developed predicts the values of KLa and
power with an average standard error of estimation of 0.0164 and
7.66 respectively and with R2 values of 0.979 and 0.989 respectively,
when compared with experimentally determined values. The
comparison of this model is done with the model generated using
Computational fluid dynamics (CFD) and both the models were
found to be in good agreement with each other.
Abstract: We studied the evolution of elliptic heavy SF6
gas cylinder surrounded by air when accelerated by a planar
Mach 1.25 shock. A multiple dynamics imaging technology has
been used to obtain one image of the experimental initial
conditions and five images of the time evolution of elliptic
cylinder. We compared the width and height of the circular and
two kinds of elliptic gas cylinders, and analyzed the vortex
strength of the elliptic ones. Simulations are in very good
agreement with the experiments, but due to the different initial
gas cylinder shapes, a certain difference of the initial density
peak and distribution exists between the circular and elliptic
gas cylinders, and the latter initial state is more sensitive and
more inenarrable.
Abstract: The proposed paper examines strategies whose aim is
to counter the all too often sighted process of abandonment that
characterizes contemporary cities. The city of Nicosia in Cyprus is
used as an indicative case study, whereby several recent projects are
presented as capitalizing on traditional cultural assets to revive the
downtown. The reuse of existing building stock as museums,
performing arts centers and theaters but also as in the form of various
housing typologies is geared to strengthen the ranks of local residents
and to spur economic growth. Unlike the examples from the 1960s,
the architecture of more recent adaptive reuse for urban regeneration
seems to be geared in reinforcing a connection to the city where the
buildings often reflect the characteristics of their urban context.
Abstract: This paper presents key challenges reported by a
group of Australian undergraduate Physical Education students in
conducting a program for persons with an intellectual disability.
Strategies adopted to address these challenges are presented together
with representative feedback given by the Physical Education
students at the completion of the program. The significance of the
program’s findings is summarized.
Abstract: As an economic and safe structure, Bi-steel is widely
used in reinforced concrete with less consumption of steel. In this
paper, III Bi-steel concrete beam has been analyzed. Through careful
observation and theoretical analysis, the new calculating formulae for
structural rigidity and crack have been formulated for this Bi-steel
concrete beam. And structural rigidity and the crack features have also
been theoretically analyzed.
Abstract: This research presented in this paper is an on-going
project of an application of neural network and fuzzy models to
evaluate the sociological factors which affect the educational
performance of the students in Sri Lanka. One of its major goals is to
prepare the grounds to device a counseling tool which helps these
students for a better performance at their examinations, especially at
their G.C.E O/L (General Certificate of Education-Ordinary Level)
examination. Closely related sociological factors are collected as raw
data and the noise of these data are filtered through the fuzzy
interface and the supervised neural network is being utilized to
recognize the performance patterns against the chosen social factors.
Abstract: A spectrophotometric method was developed for simultaneous quantification of pseudoephedrine hydrochloride (PSE) triprolidine hydrochloride (TRI) using second derivative method (zero-crossing technique). The second derivative amplitudes of PSE and TRI were measured at 271 and 321 nm, respectively. The calibration curves were linear in the range of 200 to 1,000 g/ml for PSE and 10 to 50 g/ml for TRI. The method was validated for specificity, accuracy, precision, limit of detection and limit of quantitation. The proposed method was applied to the assaying and dissolution of PSE and TRI in commercial tablets without any chemical separation. The results were compared with those obtained by the official USP31 method and statistical tests showed that there is no significant between the methods at 95% confidence level. The proposed method is simple, rapid and suitable for the routine quality control application. KeywordsTriprolidine, Pseudoephedrine, Derivative spectrophotometry, Dissolution testing.
Abstract: The Aggregate Production Plan (APP) is a schedule of
the organization-s overall operations over a planning horizon to
satisfy demand while minimizing costs. It is the baseline for any
further planning and formulating the master production scheduling,
resources, capacity and raw material planning. This paper presents a
methodology to model the Aggregate Production Planning problem,
which is combinatorial in nature, when optimized with Genetic
Algorithms. This is done considering a multitude of constraints of
contradictory nature and the optimization criterion – overall cost,
made up of costs with production, work force, inventory, and
subcontracting. A case study of substantial size, used to develop the
model, is presented, along with the genetic operators.
Abstract: A key requirement for e-learning materials is
reusability and interoperability, that is the possibility to use at least
part of the contents in different courses, and to deliver them trough
different platforms. These features make possible to limit the cost of
new packages, but require the development of material according to
proper specifications. SCORM (Sharable Content Object Reference
Model) is a set of guidelines suitable for this purpose. A specific
adaptation project has been started to make possible to reuse existing
materials. The paper describes the main characteristics of SCORM
specification, and the procedure used to modify the existing material.