Abstract: When the shock front (SF) hits the central electrode
axis of plasma focus device, a reflected shock wave moves radially
outwards. The current sheath (CS) results from ionization of filled
gas between two electrodes continues to compress inwards until it
hits the out-going reflected shock front. In this paper the Lagrangian
equations are solved for a parabolic shock trajectory yielding a first
and second approximation for the CS path. To determine the
accuracy of the approximation, the same problem is solved for a
straight shock.
Abstract: Statistics Canada stated that the wastewater treatment
facilities in most provinces are aging and passes 63% of their useful
life in 2007 the highest ratio among public infrastructure assets.
Currently, there is no standard condition rating system for wastewater
treatment plants that give a specific rating index that describe the
physical integrity of different infrastructure elements in the treatment
plant and its environmental performance. The main objective of this
study is to develop a condition-rating index for wastewater treatment
plants mainly activated sludge systems. The proposed WWTP CRI, is
based on dividing the treatment plant into its three treatment phases;
primary phase, secondary phase and the tertiary phase. The
condition-rating index will reflect the infrastructures state for each
phase, mainly tanks, pipes, blowers and pumps.
Abstract: Depression is a serious mental health problem that
affects people of all ages, including children and adolescents. Studies
showed that female gender is one of the risk factors may influence
the development of depression in adolescents. However, some of the
studies from Turkey suggested that gender does not lead to any
significant difference in the youth depression level. Therefore, the
presented study investigated whether girls differ from boys in respect
of depression. The association between genders and test scores for
the adolescents in a population of primary and secondary school
students was also evaluated. The study was consisting of 254
adolescents (122 boys and 132 girls) with a mean age of 13.86±1.43
(Mean±SD) ranging from 12-16 years. Psychological assessment was
performed using Children-s Depression Inventory (CDI). Chi-square
and Student-s t-test statistics were employed to analyze the data. The
mean of the CDI scores of the girls were higher than boys- CDI
scores (t = -4.580, p = 0.001). Higher ratio appeared for the girls
when they compared with boy group-s depression levels using a CDI
cut-off point of 19 (p = 0.001, Odds Ratio = 2,603). The findings of
the present study suggested that adolescent girls have high level of
depression than adolescent boys aged between 12-16 years in
Turkey. Although some studies reported that there is no any
differences depression level between adolescent boys and girls in
Turkey, result of the present study showed that adolescent girls have
high level of depression than adolescent boys in Turkey.
Abstract: This study had two goals. First, it investigated marital
interaction variables as predictors of treatment outcome in panic
disorder with agoraphobia (PDA) in sixty-five couples with one
spouse suffering from PDA. Second, it analyzed the impact of PDA
improvement, following therapy, on marital interaction patterns of
both spouses. The partners were observed during a problem-solving
task, before and after treatment. Negative behaviors at the outset of
therapy, both in the PDA and the NPDA partners, predicted less
improvement at post-test. It also appears that improvement in some
PDA symptoms following therapy is linked to increase in the
dominant behavior of the NPDA spouse and to an improvement in
terms of his intrusiveness.
Abstract: The growth of open networks created the interest to
commercialise it. The establishment of an electronic business
mechanism must be accompanied by a digital – electronic payment
system to transfer the value of transactions. Financial organizations
are requested to offer a secure e-payment synthesis with equivalent
level of security served in conventional paper-based payment
transactions. PKI, which is functioning as a chain of trust in security
architecture, can enable security services of cryptography to epayments,
in order to take advantage of the wider base either of
customer or of trading partners and the reduction of cost transaction
achieved by the use of Internet channels. The paper addresses the
possibilities and the implementation suggestions of PKI in relevance
to electronic payments by suggesting a framework that should be
followed.
Abstract: Green home rating has emerged as an important
agenda to practice the principles of sustainability. In Malaysia, the
establishment of the 'Green Building Index ' Residential New
Construction- (GBI-RNC) has brought this agenda closer to the
stakeholders of the local green building industry. GBI-RNC focuses
on the evaluation of the environmental impacts posed by houses
rather than assessing the Triple-Bottom-Line (TBL) of Sustainability
which also include socio-economic factors. Therefore, as part of a
wider study, a survey was conducted to gather the backgrounds of
green building stakeholders in Malaysia and their responses to a
number of exploratory questions regarding the setting up of a
framework to rate green homes against the TBL. This paper reports
the findings from Section A and B from this survey and discusses
them accordingly with a conclusion that forms part of the basis for a
new generation green home rating framework specifically for use in
Malaysia.
Abstract: This paper describes the use of artificial neural
networks (ANN) for predicting non-linear layer moduli of flexible
airfield pavements subjected to new generation aircraft (NGA)
loading, based on the deflection profiles obtained from Heavy
Weight Deflectometer (HWD) test data. The HWD test is one of the
most widely used tests for routinely assessing the structural integrity
of airport pavements in a non-destructive manner. The elastic moduli
of the individual pavement layers backcalculated from the HWD
deflection profiles are effective indicators of layer condition and are
used for estimating the pavement remaining life. HWD tests were
periodically conducted at the Federal Aviation Administration-s
(FAA-s) National Airport Pavement Test Facility (NAPTF) to
monitor the effect of Boeing 777 (B777) and Beoing 747 (B747) test
gear trafficking on the structural condition of flexible pavement
sections. In this study, a multi-layer, feed-forward network which
uses an error-backpropagation algorithm was trained to approximate
the HWD backcalculation function. The synthetic database generated
using an advanced non-linear pavement finite-element program was
used to train the ANN to overcome the limitations associated with
conventional pavement moduli backcalculation. The changes in
ANN-based backcalculated pavement moduli with trafficking were
used to compare the relative severity effects of the aircraft landing
gears on the NAPTF test pavements.
Abstract: Stegnography is a new way of secret
communication the most widely used mechanism on account
of its simplicity is the use of the least significant bit. We have
used the least significant bit (2 LSB and 4 LSB) substitution
method. Depending upon the characteristics of the individual
portions of cover image we decide whether to use 2 LSB or 4
LSB thus it is an adaptive stegnography technique. We used
one of the three channels to behave as indicator to indicate the
presence of hidden data in other two channels. The module
showed impressive results in terms of capacity to hide the
data. In proposed method, instead of using RGB color space
directly, YCbCr color space is used to make use of human
visual system characteristic.
Abstract: In this paper, we use Generalized Hamiltonian systems approach to synchronize a modified sixth-order Chua's circuit, which generates hyperchaotic dynamics. Synchronization is obtained between the master and slave dynamics with the slave being given by an observer. We apply this approach to transmit private information (analog and binary), while the encoding remains potentially secure.
Abstract: The cuticular hydrocarbons of Pamphagus elephas
(Orthoptera: Pamphagidae) has been analysed by gas
chromatography and by combined gas chromatograph-mass
spectrometry. The following hydrocarbon classes have been
identified in insect cuticular hydrocarbons are: n-alkanes and
methylalkanes comprising Monomethyl-, dimethyl-and
trimethylalkanes. Sexual dimorphism is observed in long chain
alkanes (C24-C36) present on male and female. The cuticulars
hydrocarbons of P.elephas ranged from 24 to 36 carbons and
incluted n-alkanes, Dimethylalkanes and Trimethylalkanes. nalkanes
represented by (C24-C36,72,7% on male and 79,2% on
female), internally branched Monomethylalkanes identified were
(C25, C30-C32,C35-C37;11% on male and 9,4% on female),
Dimethylalkanes detected are (C31-C32, C36; 2,2% on male and
2,06% on female) and Trimethylalkanes detected are (C32, C36;
3,1% on male and 4, 97 on female). Larvae male and female (stage
7) showed the same quality of n-alkanes observed in adults.
However a difference quantity is noted.
Abstract: The paper presents the multi-element synthetic
transmit aperture (MSTA) method with a small number of elements
transmitting and all elements apertures in medical ultrasound
imaging. As compared to the other methods MSTA allows to
increase the system frame rate and provides the best compromise
between penetration depth and lateral resolution.
In the experiments a 128-element linear transducer array with
0.3 mm pitch excited by a burst pulse of 125 ns duration were used.
The comparison of 2D ultrasound images of tissue mimicking
phantom obtained using the STA and the MSTA methods is
presented to demonstrate the benefits of the second approach. The
results were obtained using SA algorithm with transmit and receive
signals correction based on a single element directivity function.
Abstract: The need for Information Security in organizations, regardless of their type and size, is being addressed by emerging standards and recommended best practices. The various standards and practices which evolved in recent years and are still being developed and constantly revised, address the issue of Information Security from different angles. This paper attempts to provide an overview of Information Security Standards and Practices by briefly discussing some of the most popular ones. Through a comparative study of their similarities and differences, some insight can be obtained on how their combination may lead to an increased level of Information Security.
Abstract: As the number of networked computers grows,
intrusion detection is an essential component in keeping networks
secure. Various approaches for intrusion detection are currently
being in use with each one has its own merits and demerits. This
paper presents our work to test and improve the performance of a
new class of decision tree c-fuzzy decision tree to detect intrusion.
The work also includes identifying best candidate feature sub set to
build the efficient c-fuzzy decision tree based Intrusion Detection
System (IDS). We investigated the usefulness of c-fuzzy decision
tree for developing IDS with a data partition based on horizontal
fragmentation. Empirical results indicate the usefulness of our
approach in developing the efficient IDS.
Abstract: In this paper, we summarize recent work of the authors on nanocomputing memory devices. We investigate two memory devices, each comprising a charged metallofullerene and carbon nanotubes. The first device involves two open nanotubes of the same radius that are joined by a centrally located nanotube of a smaller radius. A metallofullerene is then enclosed inside the structure. The second device also involves a etallofullerene that is located inside a closed carbon nanotube. Assuming the Lennard-Jones interaction energy and the continuum approximation, for both devices, the metallofullerene has two symmetrically placed equal minimum energy positions. On one side the metallofullerene represents the zero information state and by applying an external electrical field, it can overcome the energy barrier, and pass from one end of the tube to the other, where the metallofullerene then represents the one information state.
Abstract: This article deals with numerical simulation of the
floor heating convector in 3D. Numerical simulation is focused on
cooling mode of the floor heating convector. Geometrical model
represents section of the heat exchanger – two fins with the gap
between, pipes are not involved. Two types of fin are examined –
sinusoidal and angular shape with different fin spacing. Results of fin
spacing in case of constant Reynolds number are presented. For the
numerical simulation was used commercial software Ansys Fluent.
Abstract: Worm propagation profiles have significantly changed
since 2003-2004: sudden world outbreaks like Blaster or Slammer
have progressively disappeared and slower but stealthier worms
appeared since, most of them for botnets dissemination. Decreased
worm virulence results in more difficult detection.
In this paper, we describe a stealth worm propagation model
which has been extensively simulated and analysed on a huge virtual
network. The main features of this model is its ability to infect any
Internet-like network in a few seconds, whatever may be its size while
greatly limiting the reinfection attempt overhead of already infected
hosts. The main simulation results shows that the combinatorial
topology of routing may have a huge impact on the worm propagation
and thus some servers play a more essential and significant role than
others. The real-time capability to identify them may be essential to
greatly hinder worm propagation.
Abstract: Because of the great advance in multimedia
technology, digital multimedia is vulnerable to malicious
manipulations. In this paper, a public key self-recovery block-based
video authentication technique is proposed which can not only
precisely localize the alteration detection but also recover the missing
data with high reliability. In the proposed block-based technique,
multiple description coding MDC is used to generate two codes (two
descriptions) for each block. Although one block code (one
description) is enough to rebuild the altered block, the altered block
is rebuilt with better quality by the two block descriptions. So using
MDC increases the ratability of recovering data. A block signature is
computed using a cryptographic hash function and a doubly linked
chain is utilized to embed the block signature copies and the block
descriptions into the LSBs of distant blocks and the block itself. The
doubly linked chain scheme gives the proposed technique the
capability to thwart vector quantization attacks. In our proposed
technique , anyone can check the authenticity of a given video using
the public key. The experimental results show that the proposed
technique is reliable for detecting, localizing and recovering the
alterations.
Abstract: Series of experimental tests were conducted on a
section of a 660 kW wind turbine blade to measure the pressure
distribution of this model oscillating in plunging motion. In order to
minimize the amount of data required to predict aerodynamic loads
of the airfoil, a General Regression Neural Network, GRNN, was
trained using the measured experimental data. The network once
proved to be accurate enough, was used to predict the flow behavior
of the airfoil for the desired conditions.
Results showed that with using a few of the acquired data, the
trained neural network was able to predict accurate results with
minimal errors when compared with the corresponding measured
values. Therefore with employing this trained network the
aerodynamic coefficients of the plunging airfoil, are predicted
accurately at different oscillation frequencies, amplitudes, and angles
of attack; hence reducing the cost of tests while achieving acceptable
accuracy.
Abstract: The public sector holds large amounts of data of
various areas such as social affairs, economy, or tourism. Various
initiatives such as Open Government Data or the EU Directive on
public sector information aim to make these data available for public
and private service providers. Requirements for the provision of
public sector data are defined by legal and organizational
frameworks. Surprisingly, the defined requirements hardly cover
security aspects such as integrity or authenticity.
In this paper we discuss the importance of these missing
requirements and present a concept to assure the integrity and
authenticity of provided data based on electronic signatures. We
show that our concept is perfectly suitable for the provisioning of
unaltered data. We also show that our concept can also be extended
to data that needs to be anonymized before provisioning by
incorporating redactable signatures. Our proposed concept enhances
trust and reliability of provided public sector data.
Abstract: Coherent and incoherent scattering cross section measurements have been carried out using a HPGe detector on elements in the range of Z = 13 - 50 using 241Am gamma rays. The cross sections have been derived by comparing the net count rate obtained from the Compton peak of aluminium with the corresponding peak of the target. The measured cross sections for the coherent and incoherent processes are compared with theoretical values and earlier reported values. Our results are in agreement with the theoretical values.