Abstract: This paper presents a linear stability analysis of
natural convection in a horizontal layer of a viscoelastic
nanofluid. The Oldroyd B model was utilized to describe the
rheological behavior of a viscoelastic nanofluid. The model
used for the nanofluid incorporated the effects of Brownian
motion and thermophoresis. The onset criterion for stationary
and oscillatory convection was derived analytically. The effects
of the Deborah number, retardation parameters, concentration
Rayleigh number, Prandtl number, and Lewis number on the
stability of the system were investigated. Results indicated that
there was competition among the processes of thermophoresis,
Brownian diffusion, and viscoelasticity which caused
oscillatory rather than stationary convection to occur.
Oscillatory instability is possible with both bottom- and
top-heavy nanoparticle distributions. Regimes of stationary and
oscillatory convection for various parameters were derived and
are discussed in detail.
Abstract: 'Secure routing in Mobile Ad hoc networks' and
'Internet connectivity to Mobile Ad hoc networks' have been dealt
separately in the past research. This paper proposes a light weight
solution for secure routing in integrated Mobile Ad hoc Network
(MANET)-Internet. The proposed framework ensures mutual
authentication of Mobile Node (MN), Foreign Agent (FA) and Home
Agent (HA) to avoid various attacks on global connectivity and
employs light weight hop-by-hop authentication and end-to-end
integrity to protect the network from most of the potential security
attacks. The framework also uses dynamic security monitoring
mechanism to monitor the misbehavior of internal nodes. Security
and performance analysis show that our proposed framework
achieves good security while keeping the overhead and latency
minimal.
Abstract: Extensive information is required within a R&D environment,
and a considerable amount of time and efforts are being
spent on finding the necessary information. An adaptive information
providing system would be beneficial to the environment, and a
conceptual model of the resources, people and context is mandatory
for developing such applications. In this paper, an information model
on various contexts and resources is proposed which provides the
possibility of effective applications for use in adaptive information
systems within a R&D project and meeting environment.
Abstract: Information hiding for authenticating and verifying the content integrity of the multimedia has been exploited extensively in the last decade. We propose the idea of using genetic algorithm and non-deterministic dependence by involving the un-watermarkable coefficients for digital image authentication. Genetic algorithm is used to intelligently select coefficients for watermarking in a DCT based image authentication scheme, which implicitly watermark all the un-watermarkable coefficients also, in order to thwart different attacks. Experimental results show that such intelligent selection results in improvement of imperceptibility of the watermarked image, and implicit watermarking of all the coefficients improves security against attacks such as cover-up, vector quantization and transplantation.
Abstract: The two significant overvoltages in power system,
switching overvoltage and lightning overvoltage, are investigated in
this paper. Firstly, the effect of various power system parameters on
Line Energization overvoltages is evaluated by simulation in ATP.
The dominant parameters include line parameters; short-circuit
impedance and circuit breaker parameters. Solutions to reduce
switching overvoltages are reviewed and controlled closing using
switchsync controllers is proposed as proper method.
This paper also investigates lightning overvoltages in the
overhead-cable transition. Simulations are performed in
PSCAD/EMTDC. Surge arresters are applied in both ends of cable to
fulfill the insulation coordination. The maximum amplitude of
overvoltages inside the cable is surveyed which should be of great
concerns in insulation coordination studies.
Abstract: In studying the possibility of using plants as
rhizoremediators, barley and grass mixture which showed resistance
to various concentrations of oil were selected. The minimum
inhibitory effect of oil on these plants by morphological parameters
such as survival of plants, length and biomass of shoot and root
compared with the control was showed. In determining physiological
parameters, a slight decrease in the number of chlorophyll a and b in
the leaves of plants was noted. The differences in the ratio of the total
surface of the roots to the work surface with the growth of plants in
soil with oil in the study of adsorption of the root surface were
showed.
Abstract: Inconel718 has been widely used as a super alloy in aerospace application due to the high strength at elevated temperatures, satisfactory oxidation resistance and heat corrosion resistance. In this study, the Inconel718 has been fabricated using high technology of Metal Injection Molding (MIM) process due to the cost effective technique for producing small, complex and precision parts in high volume compared with conventional method through machining. Through MIM, the binder system is one of the most important criteria in order to successfully fabricate the Inconel718. Even though, the binder system is a temporary, but failure in the selection and removal of the binder system will affect on the final properties of the sintered parts. Therefore, the binder system based on palm oil derivative which is palm stearin has been formulated and developed to replace the conventional binder system. The rheological studies of the mixture between the powder and binders system have been determined properly in order to be successful during injection into injection molding machine. After molding, the binder holds the particles in place. The binder system has to be removed completely through debinding step. During debinding step, solvent debinding and thermal pyrolysis has been used to remove completely of the binder system. The debound part is then sintered to give the required physical and mechanical properties. The results show that the properties of the final sintered parts fulfill the Standard Metal Powder Industries Federation (MPIF) 35 for MIM parts.
Abstract: The effect of seed inoculation by VA- mycorrhiza and
different levels of phosphorus fertilizer on growth and yield of
sunflower (Azargol cultivar) was studied in experiment farm of
Islamic Azad University, Karaj Branch during 2008 growing season.
The experiment treatments were arranged in factorial based on a
complete randomized block design with three replications. Four
phosphorus fertilizer levels of 25%, 50% 75% and 100% P
recommended with two levels of Mycorrhiza: with and without
Mycorrhiza (control) were assigned in a factorial combination.
Results showed that head diameter, number of seeds in head, seed
yield and oil yield were significantly higher in inoculated plants than
in non-inoculated plants. Head diameter, number of seeds in head,
1000 seeds weight, biological yield, seed yield and oil yield increased
with increasing P level above 75% P recommended in non-inoculated
plants, whereas no significant difference was observed between 75%
and 100% P recommended. The positive effect of mycorrhizal
inoculation decreased with increasing P levels due to decreased
percent root colonization at higher P levels. According to the results
of this experiment, application of mycorrhiza in present of 50% P
recommended had an appropriate performance and could increase
seed yield and oil production to an acceptable level, so it could be
considered as a suitable substitute for chemical phosphorus fertilizer
in organic agricultural systems.
Abstract: Super-quadrics can represent a set of implicit surfaces,
which can be used furthermore as primitive surfaces to construct a
complex object via Boolean set operations in implicit surface
modeling. In fact, super-quadrics were developed to create a
parametric surface by performing spherical product on two parametric
curves and some of the resulting parametric surfaces were also
represented as implicit surfaces. However, because not every
parametric curve can be redefined implicitly, this causes only implicit
super-elliptic and super-hyperbolic curves are applied to perform
spherical product and so only implicit super-ellipsoids and
hyperboloids are developed in super-quadrics. To create implicit
surfaces with more diverse shapes than super-quadrics, this paper
proposes an implicit representation of spherical product, which
performs spherical product on two implicit curves like super-quadrics
do. By means of the implicit representation, many new implicit curves
such as polygonal, star-shaped and rose-shaped curves can be used to
develop new implicit surfaces with a greater variety of shapes than
super-quadrics, such as polyhedrons, hyper-ellipsoids, superhyperboloids
and hyper-toroids containing star-shaped and roseshaped
major and minor circles. Besides, the newly developed implicit
surfaces can also be used to define new primitive implicit surfaces for
constructing a more complex implicit surface in implicit surface
modeling.
Abstract: At the previous study of new metal gasket, contact
width and contact stress were important design parameter for
optimizing metal gasket performance. However, the range of contact
stress had not been investigated thoroughly. In this study, we
conducted a gasket design optimization based on an elastic and plastic
contact stress analysis considering forming effect using FEM. The
gasket model was simulated by using two simulation stages which is
forming and tightening simulation. The optimum design based on an
elastic and plastic contact stress was founded. Final evaluation was
determined by helium leak quantity to check leakage performance of
both type of gaskets. The helium leak test shows that a gasket based
on the plastic contact stress design better than based on elastic stress
design.
Abstract: In this paper, we implement a modern serial backplane
platform for telecommunication inter-rack systems. For combination
high reliability and low cost protocol property, we applied high level
data link control (HDLC) protocol with low voltage differential
signaling (LVDS) bus for card to card communicated over backplane.
HDLC protocol is a high performance with several operation modes
and is famous in telecommunication systems. LVDS bus is a high
reliability with high immunity against electromagnetic interference
(EMI) and noise.
Abstract: Understanding the number of people and the flow of
the persons is useful for efficient promotion of the institution
managements and company-s sales improvements. This paper
introduces an automated method for counting passerby using virtualvertical
measurement lines. The process of recognizing a passerby is
carried out using an image sequence obtained from the USB camera.
Space-time image is representing the human regions which are
treated using the segmentation process. To handle the problem of
mismatching, different color space are used to perform the template
matching which chose automatically the best matching to determine
passerby direction and speed. A relation between passerby speed and
the human-pixel area is used to distinguish one or two passersby. In
the experiment, the camera is fixed at the entrance door of the hall in
a side viewing position. Finally, experimental results verify the
effectiveness of the presented method by correctly detecting and
successfully counting them in order to direction with accuracy of
97%.
Abstract: To distinguish small retinal hemorrhages in early
diabetic retinopathy from dust artifacts, we analyzed hue, lightness,
and saturation (HLS) color spaces. The fundus of 5 patients with
diabetic retinopathy was photographed. For the initial experiment, we
placed 4 different colored papers on the ceiling of a darkroom. Using
each color, 10 fragments of house dust particles on a magnifier were
photographed. The colored papers were removed, and 3 different
colored light bulbs were suspended from the ceiling. Ten fragments of
house dust particles on the camera-s object lens were photographed.
We then constructed an experimental device that can photograph
artificial eyes. Five fragments of house dust particles under the ocher
fundus of the artificial eye were photographed. On analyzing HLS
color space of the dust artifact, lightness and saturation were found to
be highly sensitive. However, hue was not highly sensitive.
Abstract: Solar shading designs are important for reduction of building energy consumption and improvement of indoor thermal environment. This paper carried out a number of building simulations for evaluation of the energy performance of different shading devices based on incremental costs. The results show that movable shading devices lower incremental costs by up to 50% compared with fixed ones for the same building energy efficiency for residential buildings, and wing panel shadings are much more suitable in commercial buildings than baring screen ones and overhangs for commercial buildings.
Abstract: The aim of this paper is to study in depth some methodological aspects of social interventation, focusing on desirable passage from social maternage method to peer advocacy method. For this purpose, we intend analyze social and organizative components, that affect operator's professional action and that are part of his psychological environment, besides the physical and social one. In fact, operator's interventation should not be limited to a pure supply of techniques, nor to take shape as improvised action, but “full of good purposes".
Abstract: This paper proposes an architectural and graphical
user interface (GUI) design of a traditional Thai musical instrument
application for tablet computers for practicing “Ranaad Ek" which is
a trough-resonated keyboard percussion instrument. The application
provides percussion methods for a player as real as a physical
instrument. The application consists of two playing modes. The first
mode is free playing, a player can freely multi touches on wooden bar
to produce instrument sounds. The second mode is practicing mode
that guilds the player to follow percussions and rhythms of practice
songs. The application has achieved requirements and specifications.
Abstract: Optical character recognition of cursive scripts
presents a number of challenging problems in both segmentation and
recognition processes in different languages, including Persian. In
order to overcome these problems, we use a newly developed Persian
word segmentation method and a recognition-based segmentation
technique to overcome its segmentation problems. This method is
robust as well as flexible. It also increases the system-s tolerances to
font variations. The implementation results of this method on a
comprehensive database show a high degree of accuracy which meets
the requirements for commercial use. Extended with a suitable pre
and post-processing, the method offers a simple and fast framework
to develop a full OCR system.
Abstract: Tourism industries are rapidly increased for the last
few years especially in Malaysia. In order to attract more tourists,
Malaysian Governance encourages any effort to increase Malaysian
tourism industry. One of the efforts in attracting more tourists in
Malacca, Malaysia is a duck tour. Duck tour is an amphibious
sightseeing tour that works in two types of engines, hence, it required
a huge cost to operate and maintain the vehicle. To other country, it is
not so new but in Malaysia, it is just introduced, thus it does not have
any systematic routing yet. Therefore, this paper proposed an
optimization technique to formulate and schedule this tour to
minimize the operating costs by considering it into Travelling
Salesman Problem (TSP). The problem is then can be solved by one
of the optimization technique especially meta-heuristics approach
such as Tabu Search (TS) and Reactive Tabu Search (RTS).
Abstract: Exact expressions for bit-error probability (BEP) for
coherent square detection of uncoded and coded M-ary quadrature
amplitude modulation (MQAM) using an array of antennas with
maximal ratio combining (MRC) in a flat fading channel interference
limited system in a Nakagami-m fading environment is derived. The
analysis assumes an arbitrary number of independent and identically
distributed Nakagami interferers. The results for coded MQAM are
computed numerically for the case of (24,12) extended Golay code
and compared with uncoded MQAM by plotting error probabilities
versus average signal-to-interference ratio (SIR) for various values of
order of diversity N, number of distinct symbols M, in order to
examine the effect of cochannel interferers on the performance of the
digital communication system. The diversity gains and net gains are
also presented in tabular form in order to examine the performance of
digital communication system in the presence of interferers, as the
order of diversity increases. The analytical results presented in this
paper are expected to provide useful information needed for design
and analysis of digital communication systems with space diversity
in wireless fading channels.
Abstract: This paper presents a research conducted to investigate the effect of mixing process on polypropylene (PP) modified bitumen mixed with well graded aggregate to form modified bituminous concrete mix. Two mode of mixing, namely dry and wet with different concentration of polymer polypropylene was used with 80/100 pen bitumen, to evaluate the bituminous concrete mix properties. Three percentages of polymer varying from 1-3% by the weight of bitumen was used in this study. Three mixes namely control mix, wet mix and dry mix were prepared. Optimum binder content was calculated considering Marshall Stability, flow, air voids and Marshall Quotient at different bitumen content varying from 4% - 6.5% for control, dry and wet mix. Engineering properties thus obtained at the calculated optimum bitumen content revealed that wet mixing process is advantageous in comparison to dry mixing as it increases the stiffness of the mixture with the increase in polymer content in bitumen. Stiffness value for wet mix increases with the increase in polymer content which is beneficial in terms of rutting. 1% PP dry mix also shows enhanced stiffness, with the air void content limited to 4%.The flow behaviour of dry mix doesn't indicate any major difference with the increase in polymer content revealing that polymer acting as an aggregate only without affecting the viscosity of the binder in the mix. Polypropylene (PP) when interacted with 80 pen base bitumen enhances its performance characteristics which were brought about by altered rheological properties of the modified bitumen. The decrease in flow with the increase in binder content reflects the increase in viscosity of binder which induces the plastic flow in the mix. Workability index indicates that wet mix were easy to compact up to desired void ratio in comparison to dry mix samples.