Abstract: The overall objective of this paper is to retrieve soil
surfaces parameters namely, roughness and soil moisture related to
the dielectric constant by inverting the radar backscattered signal
from natural soil surfaces.
Because the classical description of roughness using statistical
parameters like the correlation length doesn't lead to satisfactory
results to predict radar backscattering, we used a multi-scale
roughness description using the wavelet transform and the Mallat
algorithm. In this description, the surface is considered as a
superposition of a finite number of one-dimensional Gaussian
processes each having a spatial scale. A second step in this study
consisted in adapting a direct model simulating radar backscattering
namely the small perturbation model to this multi-scale surface
description. We investigated the impact of this description on radar
backscattering through a sensitivity analysis of backscattering
coefficient to the multi-scale roughness parameters.
To perform the inversion of the small perturbation multi-scale
scattering model (MLS SPM) we used a multi-layer neural network
architecture trained by backpropagation learning rule. The inversion
leads to satisfactory results with a relative uncertainty of 8%.
Abstract: To investigate the applicability of the EDR-2 film for
clinical radiation dosimetry, percentage depth-doses, profiles and
distributions in open and dynamically wedged fields were measured
using film and compared with data from a Treatment Planning
system.The validity of the EDR2 film to measure dose in a plane
parallel to the beam was tested by irradiating 10 cm×10 cm and 4
cm×4 cm fields from a Siemens, primus linac with a 6MV beam and
a source-to-surface distance of 100 cm. The film was placed
Horizontally between solid water phantom blocks and marked
with pin holes at a depth of 10 cm from the incident beam surface.
The film measurement results, in absolute dose, were compared with
ion chamber measurements using a Welhoffer scanning water tank
system and Treatment Planning system. Our results indicate a
maximum underestimate of calculated dose of 8 % with Treatment
Planning system.
Abstract: Flow around a flat tube is studied numerically. Reynolds number is defined base on equivalent circular tube and it is varied in range of 100 to 300. Equations are solved by using finite volume method and results are presented in form of drag and lift coefficient. Results show that drag coefficient of flat tube is up to 66% lower than circular tube with equivalent diameter. In addition, by increasing l/D from 1 to 2, the drag coefficient of flat tube is decreased about 14-27%.
Abstract: The burst of Web 2.0 technology and social
networking tools manifest different styles of learning and managing
knowledge among both knowledge workers and adult learners. In the
Western countries, open-learning concept has been made popular due
to the ease of use and the reach that the technology provides. In
Malaysia, there are still some gaps between the learners- acceptance
of technology and the full implementation of the technology in the
education system. There is a need to understand how adult learners,
who are knowledge workers, manage their personal knowledge via
social networking tools, especially in their learning process. Four
processes of personal knowledge management (PKM) and four
cognitive enablers are proposed supported by analysed data on adult
learners in a university. The model derived from these processes and
enablers is tested and presented, with recommendations on features to be included in adult learners- learning environment.
Abstract: Cements, which are intrinsically brittle materials, can
exhibit a degree of pseudo-ductility when reinforced with a sufficient
volume fraction of a fibrous phase. This class of materials, called
Engineered Cement Composites (ECC) has the potential to be used in
future tunneling applications where a level of pseudo-ductility is
required to avoid brittle failures. However uncertainties remain
regarding mechanical performance. Previous work has focused on
comparatively thin specimens; however for future civil engineering
applications, it is imperative that the behavior in tension of thicker
specimens is understood. In the present work, specimens containing
cement powder and admixtures have been manufactured following
two different processes and tested in tension. Multiple matrix
cracking has been observed during tensile testing, leading to a
“strain-hardening" behavior, confirming the possible suitability of
ECC material when used as thick sections (greater than 50mm) in
tunneling applications.
Abstract: In order to be able to automatically differentiate
between two modes of permanent flow of a liquid simulating blood,
it was imperative to put together a data bank. Thus, the acquisition of
the various amplitude spectra of the Doppler signal of this liquid in
laminar flow and other spectra in turbulent flow enabled us to
establish an automatic difference between the two modes. According
to the number of parameters and their nature, a comparative study
allowed us to choose the best classifier.
Abstract: This paper presents an approach for the determination of the optimal cutting parameters (spindle speed, feed rate, depth of cut and engagement) leading to minimum surface roughness in face milling of high silicon stainless steel by coupling neural network (NN) and Electromagnetism-like Algorithm (EM). In this regard, the advantages of statistical experimental design technique, experimental measurements, artificial neural network, and Electromagnetism-like optimization method are exploited in an integrated manner. To this end, numerous experiments on this stainless steel were conducted to obtain surface roughness values. A predictive model for surface roughness is created by using a back propogation neural network, then the optimization problem was solved by using EM optimization. Additional experiments were performed to validate optimum surface roughness value predicted by EM algorithm. It is clearly seen that a good agreement is observed between the predicted values by EM coupled with feed forward neural network and experimental measurements. The obtained results show that the EM algorithm coupled with back propogation neural network is an efficient and accurate method in approaching the global minimum of surface roughness in face milling.
Abstract: One of the most attractive and important field of chaos theory is control of chaos. In this paper, we try to present a simple framework for chaotic motion control using the feedback linearization method. Using this approach, we derive a strategy, which can be easily applied to the other chaotic systems. This task presents two novel results: the desired periodic orbit need not be a solution of the original dynamics and the other is the robustness of response against parameter variations. The illustrated simulations show the ability of these. In addition, by a comparison between a conventional state feedback and our proposed method it is demonstrated that the introduced technique is more efficient.
Abstract: Ipomoea batatas (Sweetpotato) is currently ranked
sixth in the total world food production and are planted mainly for
their storage roots. The present study was undertaken to evaluate and
compare the antioxidant properties of the leaf and carotenoids extract
from the Ipomoea batatas var. Oren leaves. Total flavonoids in the
leaf extract was 144.6 ± 40.5 μg/g compared to 114.86 ± 4.35 μg/g
catechin equivalent in the carotenoids extract. Total polyphenols in
the leaf extracts (3.470 ± 0.024 GAE g/100g DW) was slightly higher
compared to carotenoids extract (2.994 ± 0.078 GAE g/100g DW).
The carotenoids extract marked a higher radical scavenging capacity
with the IC50= 491.86 μg/ml compared to leaf extract (IC50= 545.39
μg/ml). Concentration-dependent reducing activity was observed for
both extracts. Thus, the carotenoids extraction process retained most
of the antioxidant capacity from the leaves and can be made into
potential natural yellow dye with antioxidant property.
Abstract: Dehydration of methanol to dimethyl ether (DME)
over a commercial Al2O3 catalyst was studied in an isothermal integral
fixed bed reactor. The experiments were performed on the temperature
interval 513-613 K, liquid hourly space velocity (LHSV) of 0.9-2.1h-1,
pressures between 0.1 and 1.0 MPa. The effect of different operation
conditions on the dehydration of methanol was investigated in a
laboratory scale experiment. A new intrinsic kinetics equation based
on the mechanism of Langmuir-Hinshelwood dissociation adsorption
was developed for the dehydration reaction by fitting the expressions
to the experimental data. An activation energy of 67.21 kJ/mol was
obtained for the catalyst with the best performance. Statistic test
showed that this new intrinsic kinetics equation was acceptable.
Abstract: The seismic feedback experiences in Algeria have
shown higher percentage of damages for non-code conforming
reinforced concrete (RC) buildings. Furthermore, the vulnerability of
these buildings was further aggravated due to presence of many
factors (e.g. weak the seismic capacity of these buildings, shorts
columns, Pounding effect, etc.).
Consequently Seismic risk assessments were carried out on
populations of buildings to identify the buildings most likely to
undergo losses during an earthquake. The results of such studies are
important in the mitigation of losses under future seismic events as
they allow strengthening intervention and disaster management plans
to be drawn up.
Within this paper, the state of the existing structures is assessed using
"the vulnerability index" method. This method allows the
classification of RC constructions taking into account both, structural
and non structural parameters, considered to be ones of the main
parameters governing the vulnerability of the structure. Based on
seismic feedback from past earthquakes DPM (damage probability
matrices) were developed too.
Abstract: Traffic flow in adverse weather conditions have been investigated in this study for general traffic, week day and week end traffic. The empirical evidence is strong in support of the view that rainfall affects macroscopic traffic flow parameters. Data generated from a basic highway section along J5 in Johor Bahru, Malaysia was synchronized with 161 rain events over a period of three months. This revealed a 4.90%, 6.60% and 11.32% reduction in speed for light rain, moderate rain and heavy rain conditions respectively. The corresponding capacity reductions in the three rainfall regimes are 1.08% for light rain, 6.27% for moderate rain and 29.25% for heavy rain. In the week day traffic, speed drops of 8.1% and 16.05% were observed for light and heavy conditions. The moderate rain condition speed increased by 12.6%. The capacity drops for week day traffic are 4.40% for light rain, 9.77% for moderate rain and 45.90% for heavy rain. The weekend traffic indicated speed difference between the dry condition and the three rainy conditions as 6.70% for light rain, 8.90% for moderate rain and 13.10% for heavy rain. The capacity changes computed for the weekend traffic were 0.20% in light rain, 13.90% in moderate rain and 16.70% in heavy rain. No traffic instabilities were observed throughout the observation period and the capacities reported for each rain condition were below the norain condition capacity. Rainfall has tremendous impact on traffic flow and this may have implications for shock wave propagation.
Abstract: This paper reports the study results on neural network
training algorithm of numerical optimization techniques multiface
detection in static images. The training algorithms involved are scale
gradient conjugate backpropagation, conjugate gradient
backpropagation with Polak-Riebre updates, conjugate gradient
backpropagation with Fletcher-Reeves updates, one secant
backpropagation and resilent backpropagation. The final result of
each training algorithms for multiface detection application will also
be discussed and compared.
Abstract: The Petri net tool INA is a well known tool by the
Petri net community. However, it lacks a graphical environment to
cerate and analyse INA models. Building a modelling tool for the
design and analysis from scratch (for INA tool for example) is
generally a prohibitive task. Meta-Modelling approach is useful to
deal with such problems since it allows the modelling of the
formalisms themselves. In this paper, we propose an approach based
on the combined use of Meta-modelling and Graph Grammars to
automatically generate a visual modelling tool for INA for analysis
purposes. In our approach, the UML Class diagram formalism is
used to define a meta-model of INA models. The meta-modelling
tool ATOM3 is used to generate a visual modelling tool according to
the proposed INA meta-model. We have also proposed a graph
grammar to automatically generate INA description of the
graphically specified Petri net models. This allows the user to avoid
the errors when this description is done manually. Then the INA tool
is used to perform the simulation and the analysis of the resulted INA
description. Our environment is illustrated through an example.
Abstract: Shadows add great amount of realism to a scene and
many algorithms exists to generate shadows. Recently, Shadow
volumes (SVs) have made great achievements to place a valuable
position in the gaming industries. Looking at this, we concentrate on
simple but valuable initial partial steps for further optimization in SV
generation, i.e.; model simplification and silhouette edge detection
and tracking. Shadow volumes (SVs) usually takes time in generating
boundary silhouettes of the object and if the object is complex then
the generation of edges become much harder and slower in process.
The challenge gets stiffer when real time shadow generation and
rendering is demanded. We investigated a way to use the real time
silhouette edge detection method, which takes the advantage of
spatial and temporal coherence, and exploit the level-of-details
(LOD) technique for reducing silhouette edges of the model to use
the simplified version of the model for shadow generation speeding
up the running time. These steps highly reduce the execution time of
shadow volume generations in real-time and are easily flexible to any
of the recently proposed SV techniques. Our main focus is to exploit
the LOD and silhouette edge detection technique, adopting them to
further enhance the shadow volume generations for real time
rendering.
Abstract: The main goal of the study is to analyze all relevant properties of the electro hydraulic systems and based on that to make a proper choice of the neural network control strategy that may be used for the control of the mechatronic system. A combination of electronic and hydraulic systems is widely used since it combines the advantages of both. Hydraulic systems are widely spread because of their properties as accuracy, flexibility, high horsepower-to-weight ratio, fast starting, stopping and reversal with smoothness and precision, and simplicity of operations. On the other hand, the modern control of hydraulic systems is based on control of the circuit fed to the inductive solenoid that controls the position of the hydraulic valve. Since this circuit may be easily handled by PWM (Pulse Width Modulation) signal with a proper frequency, the combination of electrical and hydraulic systems became very fruitful and usable in specific areas as airplane and military industry. The study shows and discusses the experimental results obtained by the control strategy of neural network control using MATLAB and SIMULINK [1]. Finally, the special attention was paid to the possibility of neuro-controller design and its application to control of electro-hydraulic systems and to make comparative with other kinds of control.
Abstract: The substrate heater designed for this investigation is a front side substrate heating system. It consists of 10 conventional tungsten halogen lamps and an aluminum reflector, total input electrical power of 5 kW. The substrate is heated by means of a radiation from conventional tungsten halogen lamps directed to the substrate through a glass window. This design allows easy replacement of the lamps and maintenance of the system. Within 2 to 6 minutes the substrate temperature reaches 500 to 830 C by varying the vertical distance between the glass window and the substrate holder. Moreover, the substrate temperature can be easily controlled by controlling the input power to the system. This design gives excellent opportunity to deposit many deferent films at deferent temperatures in the same deposition time. This substrate heater was successfully used for Chemical Vapor Deposition (CVD) of many thin films, such as Silicon, iron, etc.
Abstract: Lately, an interest has grown greatly in the usages of
RFID in an un-presidential applications. It is shown in the adaptation
of major software companies such as Microsoft, IBM, and Oracle
the RFID capabilities in their major software products. For example
Microsoft SharePoints 2010 workflow is now fully compatible with
RFID platform. In addition, Microsoft BizTalk server is also capable
of all RFID sensors data acquisition. This will lead to applications
that required high bit rate, long range and a multimedia content in
nature. Higher frequencies of operation have been designated for
RFID tags, among them are the 2.45 and 5.8 GHz. The higher the
frequency means higher range, and higher bit rate, but the drawback
is the greater cost. In this paper we present a single layer, low
profile patch antenna operates at 5.8 GHz with pure resistive input
impedance of 50 and close to directive radiation. Also, we propose
a modification to the design in order to improve the operation band
width from 8.7 to 13.8
Abstract: Setting up of rural telecentres, popularly referred to as
Common Service Centres (CSCs), are considered one of the initial
forerunners of rural e-Governance initiatives under the Government
of India-s National e-Governance Plan (NeGP). CSCs are
implemented on public-private partnership (PPP) – where State
governments play a major role in facilitating the establishment of
CSCs and investments are made by private companies referred to as
Service Centre Agencies (SCAs). CSC implementation is expected to
help in improving public service delivery in a transparent and
efficient manner. However, there is very little research undertaken to
study the actual impact of CSC implementation at the grassroots
level. This paper addresses the gap by identifying the circumstances,
concerns and expectations from the point-of-view of citizens and
examining the finer aspects of social processes in the context of rural
e-Governance.
Abstract: A novel file splitting technique for the reduction of the nth-order entropy of text files is proposed. The technique is based on mapping the original text file into a non-ASCII binary file using a new codeword assignment method and then the resulting binary file is split into several subfiles each contains one or more bits from each codeword of the mapped binary file. The statistical properties of the subfiles are studied and it is found that they reflect the statistical properties of the original text file which is not the case when the ASCII code is used as a mapper. The nth-order entropy of these subfiles are determined and it is found that the sum of their entropies is less than that of the original text file for the same values of extensions. These interesting statistical properties of the resulting subfiles can be used to achieve better compression ratios when conventional compression techniques are applied to these subfiles individually and on a bit-wise basis rather than on character-wise basis.