Abstract: We present an approach to triangle mesh simplification
designed to be executed on the GPU. We use a quadric error metric
to calculate an error value for each vertex of the mesh and order all
vertices based on this value. This step is followed by the parallel
removal of a number of vertices with the lowest calculated error
values. To allow for the parallel removal of multiple vertices we use
a set of per-vertex boundaries that prevent mesh foldovers even when
simplification operations are performed on neighbouring vertices. We
execute multiple iterations of the calculation of the vertex errors,
ordering of the error values and removal of vertices until either a
desired number of vertices remains in the mesh or a minimum error
value is reached. This parallel approach is used to speed up the
simplification process while maintaining mesh topology and avoiding
foldovers at every step of the simplification.
Abstract: The maintenance of work rolls in hot strip processing
has been lengthy and difficult tasks for hot strip manufacturer
because heavy work rolls have to be taken out of the production line,
which could take hours. One way to increase the time between
maintenance is to improve the effectiveness of the work roll cooling
system such that the wear and tear more slowly occurs, while the
operation cost is kept low. Therefore, this study aims to improve the
work roll cooling system by providing the manufacturer the
relationship between the work-roll temperature reduced by cooling
and the water flow that can help manufacturer determining the more
effective water flow of the cooling system. The relationship is found
using simulation with a systematic process adjustment so that the
satisfying quality of product is achieved. Results suggest that the
manufacturer could reduce the water flow by 9% with roughly the
same performance. With the same process adjustment, the feasibility
of finishing-mill-stand reduction is also investigated. Results suggest
its possibility.
Abstract: The present paper examines the impact noise
transmission through some floor building assemblies. The Acoubat
software numerical simulation has been used to simulate the impact
noise transmission through different floor configurations used in
Algerian construction mode. The results are compared with the
available measurements. We have developed two experimental
methods, i) field method, and ii) laboratory method using Brüel and
Kjær equipments. The results show that the different cases of floor
configurations need some improvement to ensure the acoustic
comfort in the receiving apartment. The recommended value of the
impact sound level in the receiving room should not exceed 58 dB.
The important results obtained in this paper can be used as platform
to improve the Algerian building acoustic regulation aimed at the
construction of the multi-storey residential building.
Abstract: Wireless sensors, also known as wireless sensor nodes,
have been making a significant impact on human daily life. The
Radio Frequency Identification (RFID) and Wireless Sensor Network
(WSN) are two complementary technologies; hence, an integrated
implementation of these technologies expands the overall
functionality in obtaining long-range and real-time information on the
location and properties of objects and people. An approach for
integrating ZigBee and RFID networks is proposed in this paper, to
create an energy-efficient network improved by the benefits of
combining ZigBee and RFID architecture. Furthermore, the
compatibility and requirements of the ZigBee device and
communication links in the typical RFID system which is presented
with the real world experiment on the capabilities of the proposed
RFID system.
Abstract: E-Learning enables the users to learn at anywhere at
any time. In E-Learning systems, authenticating the E-Learning user
has security issues. The usage of appropriate communication
networks for providing the internet connectivity for E-learning is
another challenge. WiMAX networks provide Broadband Wireless
Access through the Multicast Broadcast Service so these networks
can be most suitable for E-Learning applications. The authentication
of E-Learning user is vulnerable to session hijacking problems. The
repeated authentication of users can be done to overcome these
issues. In this paper, session based Profile Caching Authentication is
proposed. In this scheme, the credentials of E-Learning users can be
cached at authentication server during the initial authentication
through the appropriate subscriber station. The proposed cache based
authentication scheme performs fast authentication by using cached
user profile. Thus, the proposed authentication protocol reduces the
delay in repeated authentication to enhance the security in ELearning.
Abstract: The UK has had its fair share of the shale gas
revolutionary waves blowing across the global oil and gas industry at
present. Although, its exploitation is widely agreed to have been
delayed, shale gas was looked upon favorably by the UK Parliament
when they recognized it as genuine energy source and granted
licenses to industry to search and extract the resource. This, although
a significant progress by industry, there yet remains another test the
UK fracking resource must pass in order to render shale gas
extraction feasible – it must be economically extractible and
sustainably so. Developing unconventional resources is much more
expensive and risky, and for shale gas wells, producing in
commercial volumes is conditional upon drilling horizontal wells and
hydraulic fracturing, techniques which increase CAPEX. Meanwhile,
investment in shale gas development projects is sensitive to gas price
and technical and geological risks. Using a Two-Factor Model, the
economics of the Bowland shale wells were analyzed and the
operational conditions under which fracking is profitable in the UK
was characterized. We find that there is a great degree of flexibility
about Opex spending; hence Opex does not pose much threat to the
fracking industry in the UK. However, we discover Bowland shale
gas wells fail to add value at gas price of $8/ Mmbtu. A minimum gas
price of $12/Mmbtu at Opex of no more than $2/ Mcf and no more
than $14.95M Capex are required to create value within the present
petroleum tax regime, in the UK fracking industry.
Abstract: This paper presents the strategic development plan of
winged rockets WIRES (WInged REusable Sounding rocket) aiming
at unmanned suborbital winged rocket for demonstrating future fully
reusable space transportation technologies, such as aerodynamics,
Navigation, Guidance and Control (NGC), composite structure,
propulsion system, and cryogenic tanks etc., by universities in
collaboration with government and industries, as well as the past and
current flight test results.
Abstract: Intellectual capital is one of the most valuable and
important parts of the intangible assets of enterprises especially in
knowledge-based enterprises. With respect to increasing gap between
the market value and the book value of the companies, intellectual
capital is one of the components that can be placed in this gap. This
paper uses the value added efficiency of the three components,
capital employed, human capital and structural capital, to measure the
intellectual capital efficiency of Iranian industries groups, listed in
the Tehran Stock Exchange (TSE), using a 8 years period data set
from 2005 to 2012. In order to analyze the effect of intellectual
capital on the market-to-book value ratio of the companies, the data
set was divided into 10 industries, Banking, Pharmaceutical, Metals
& Mineral Nonmetallic, Food, Computer, Building, Investments,
Chemical, Cement and Automotive, and the panel data method was
applied to estimating pooled OLS. The results exhibited that value
added of capital employed has a positive significant relation with
increasing market value in the industries, Banking, Metals & Mineral
Nonmetallic, Food, Computer, Chemical and Cement, and also,
showed that value added efficiency of structural capital has a positive
significant relation with increasing market value in the Banking,
Pharmaceutical and Computer industries groups. The results of the
value added showed a negative relation with the Banking and
Pharmaceutical industries groups and a positive relation with
computer and Automotive industries groups. Among the studied
industries, computer industry has placed the widest gap between the
market value and book value in its intellectual capital.
Abstract: This paper investigates the thermo-electric effects
around the crack and notch tips under the electric current load. The
research methods include the finite element analysis and thermal
imaging experiment. The finite element solutions show that the electric
current density field concentrates at the crack tip. Due to the Joule
heating, this electric concentration causes the hot spot at the tip zone.
From numerical and experimental results, this hot spot is identified.
The temperature of the hot spot is affected by the electric load,
operation time and geometry of the sample.
Abstract: In this paper, a method has been developed to
construct the membership surfaces of row and column vectors and
arithmetic operations of imprecise matrix. A matrix with imprecise
elements would be called an imprecise matrix. The membership
surface of imprecise vector has been already shown based on
Randomness-Impreciseness Consistency Principle. The Randomness-
Impreciseness Consistency Principle leads to defining a normal law
of impreciseness using two different laws of randomness. In this
paper, the author has shown row and column membership surfaces
and arithmetic operations of imprecise matrix and demonstrated with
the help of numerical example.
Abstract: The inverted pendulum system is a classic control
problem that is used in universities around the world. It is a suitable
process to test prototype controllers due to its high non-linearities and
lack of stability. The inverted pendulum represents a challenging
control problem, which continually moves toward an uncontrolled
state. This paper presents the possibility of balancing an inverted
pendulum system using sliding mode control (SMC). The goal is to
determine which control strategy delivers better performance with
respect to pendulum’s angle and cart's position. Therefore,
proportional-integral-derivative (PID) is used for comparison. Results
have proven SMC control produced better response compared to PID
control in both normal and noisy systems.
Abstract: This research involved the use of word distributions
and morphological knowledge by speakers of Arabic learning English
connected different allomorphs in order to realize how the
morphology and syntax of English gives meaning through using
interactive crossword puzzles (ICP). Fifteen chapters covered with a
class of nine learners over an academic year of an intensive English
program were reviewed using the ICP. Learners were questioned
about how the use of this gaming element enhanced and motivated
their learning of English. The findings were positive indicating a
successful implementation of ICP both at creational and user levels.
This indicated a positive role technology had when learning and
teaching English through adopting an interactive gaming element for
learning English.
Abstract: Dan C. Lortie’s Schoolteacher: A sociological study is
one of the best works on the sociology of teaching since W. Waller’s
classic study. It is a book worthy of review. Following the tradition of
symbolic interactionists, Lortie demonstrated the qualities who studied
the occupation of teaching. Using several methods to gather effective
data, Lortie has portrayed the ethos of the teaching profession.
Therefore, the work is an important book on the teaching profession
and teacher culture. Though outstanding, Lortie’s work is also flawed
in that his perspectives and methodology were adopted largely from
symbolic interactionism. First, Lortie in his work analyzed many
points regarding teacher culture; for example, he was interested in
exploring “sentiment,” “cathexis,” and “ethos.” Thus, he was more a
psychologist than a sociologist. Second, symbolic interactionism led
him to discern the teacher culture from a micro view, thereby missing
the structural aspects. For example, he did not fully discuss the issue of
gender and he ignored the issue of race. Finally, following the
qualitative sociological tradition, Lortie employed many qualitative
methods to gather data but only foucused on obtaining and presenting
interview data. Moreover, he used measurement methods that were too
simplistic for analyzing quantitative data fully.
Abstract: Many embankment dams have suffered failures during
earthquakes due to the increase of pore water pressure under seismic
loading. After analyzing of the behavior of embankment dams under
severe earthquakes, major advances have been attained in the
understanding of the seismic action on dams. The present study concerns numerical analysis of the seismic
response of earth dams. The procedure uses a nonlinear stress-strain
relation incorporated into the code FLAC2D based on the finite
difference method. This analysis provides the variation of the pore
water pressure and horizontal displacement.
Abstract: The Hall Coefficient (HC) and the Magnetoresistance (MR) have been studied in two-dimensional systems. The HC and the MR in Rectangular Quantum Wire (RQW) subjected to a crossed DC electric field and magnetic field in the presence of a Strong Electromagnetic Wave (EMW) characterized by electric field are studied in this work. Using the quantum kinetic equation for electrons interacting with optical phonons, we obtain the analytic expressions for the HC and the MR with a dependence on magnetic field, EMW frequency, temperatures of systems and the length characteristic parameters of RQW. These expressions are different from those obtained for bulk semiconductors and cylindrical quantum wires. The analytical results are applied to GaAs/GaAs/Al. For this material, MR depends on the ratio of the EMW frequency to the cyclotron frequency. Indeed, MR reaches a minimum at the ratio 5/4, and when this ratio increases, it tends towards a saturation value. The HC can take negative or positive values. Each curve has one maximum and one minimum. When magnetic field increases, the HC is negative, achieves a minimum value and then increases suddenly to a maximum with a positive value. This phenomenon differs from the one observed in cylindrical quantum wire, which does not have maximum and minimum values.
Abstract: While the feature sizes of recent Complementary Metal
Oxid Semiconductor (CMOS) devices decrease the influence of static
power prevails their energy consumption. Thus, power savings that
benefit from Dynamic Frequency and Voltage Scaling (DVFS) are
diminishing and temporal shutdown of cores or other microchip
components become more worthwhile. A consequence of powering off unused parts of a chip is that the
relative difference between idle and fully loaded power consumption
is increased. That means, future chips and whole server systems gain
more power saving potential through power-aware load balancing,
whereas in former times this power saving approach had only
limited effect, and thus, was not widely adopted. While powering
off complete servers was used to save energy, it will be superfluous
in many cases when cores can be powered down. An important
advantage that comes with that is a largely reduced time to respond
to increased computational demand. We include the above developments in a server power model
and quantify the advantage. Our conclusion is that strategies from
datacenters when to power off server systems might be used in the
future on core level, while load balancing mechanisms previously
used at core level might be used in the future at server level.
Abstract: Mumbai, being traditionally the epicenter of India's
trade and commerce, the existing major ports such as Mumbai and
Jawaharlal Nehru Ports (JN) situated in Thane estuary are also
developing its waterfront facilities. Various developments over the
passage of decades in this region have changed the tidal flux
entering/leaving the estuary. The intake at Pir-Pau is facing the
problem of shortage of water in view of advancement of shoreline,
while jetty near Ulwe faces the problem of ship scheduling due to
existence of shallower depths between JN Port and Ulwe Bunder. In
order to solve these problems, it is inevitable to have information
about tide levels over a long duration by field measurements.
However, field measurement is a tedious and costly affair;
application of artificial intelligence was used to predict water levels
by training the network for the measured tide data for one lunar tidal
cycle. The application of two layered feed forward Artificial Neural
Network (ANN) with back-propagation training algorithms such as
Gradient Descent (GD) and Levenberg-Marquardt (LM) was used to
predict the yearly tide levels at waterfront structures namely at Ulwe
Bunder and Pir-Pau. The tide data collected at Apollo Bunder, Ulwe,
and Vashi for a period of lunar tidal cycle (2013) was used to train,
validate and test the neural networks. These trained networks having
high co-relation coefficients (R= 0.998) were used to predict the tide
at Ulwe, and Vashi for its verification with the measured tide for the
year 2000 & 2013. The results indicate that the predicted tide levels
by ANN give reasonably accurate estimation of tide. Hence, the
trained network is used to predict the yearly tide data (2015) for
Ulwe. Subsequently, the yearly tide data (2015) at Pir-Pau was
predicted by using the neural network which was trained with the
help of measured tide data (2000) of Apollo and Pir-Pau. The analysis of measured data and study reveals that: The
measured tidal data at Pir-Pau, Vashi and Ulwe indicate that there is
maximum amplification of tide by about 10-20 cm with a phase lag
of 10-20 minutes with reference to the tide at Apollo Bunder
(Mumbai). LM training algorithm is faster than GD and with increase
in number of neurons in hidden layer and the performance of the
network increases. The predicted tide levels by ANN at Pir-Pau and
Ulwe provides valuable information about the occurrence of high and
low water levels to plan the operation of pumping at Pir-Pau and
improve ship schedule at Ulwe.
Abstract: The source of the jet noise is generated by rocket exhaust plume during rocket engine testing. A domain decomposition approach is applied to the jet noise prediction in this paper. The aerodynamic noise coupling is based on the splitting into acoustic sources generation and sound propagation in separate physical domains. Large Eddy Simulation (LES) is used to simulate the supersonic jet flow. Based on the simulation results of the flow-fields, the jet noise distribution of the sound pressure level is obtained by applying the Ffowcs Williams-Hawkings (FW-H) acoustics equation and Fourier transform. The calculation results show that the complex structures of expansion waves, compression waves and the turbulent boundary layer could occur due to the strong interaction between the gas jet and the ambient air. In addition, the jet core region, the shock cell and the sound pressure level of the gas jet increase with the nozzle size increasing. Importantly, the numerical simulation results of the far-field sound are in good agreement with the experimental measurements in directivity.
Abstract: Open jet testing is a valuable testing technique which
provides the desired results with reasonable accuracy. It has been
used in past for the airships and now has recently been applied for the
hybrid ones, having more non-buoyant force coming from the wings,
empennage and the fuselage. In the present review work, an effort
has been done to review the challenges involved in open jet testing.
In order to shed light on the application of this technique, the
experimental results of two different configurations are presented.
Although, the aerodynamic results of such vehicles are unique to its
own design; however, it will provide a starting point for planning any
future testing. Few important testing areas which need more attention
are also highlighted. Most of the hybrid buoyant aerial vehicles are
unconventional in shape and there experimental data is generated,
which is unique to its own design.
Abstract: Magnetic Resonance Imaging Contrast Agents
(MRI-CM) are significant in the clinical and biological imaging as
they have the ability to alter the normal tissue contrast, thereby
affecting the signal intensity to enhance the visibility and detectability
of images. Superparamagnetic Iron Oxide (SPIO) nanoparticles,
coated with dextran or carboxydextran are currently available for
clinical MR imaging of the liver. Most SPIO contrast agents are
T2 shortening agents and Resovist (Ferucarbotran) is one of a
clinically tested, organ-specific, SPIO agent which has a low
molecular carboxydextran coating. The enhancement effect of
Resovist depends on its relaxivity which in turn depends on factors
like magnetic field strength, concentrations, nanoparticle properties,
pH and temperature. Therefore, this study was conducted to
investigate the impact of field strength and different contrast
concentrations on enhancement effects of Resovist. The study
explored the MRI signal intensity of Resovist in the physiological
range of plasma from T2-weighted spin echo sequence at three
magnetic field strengths: 0.47 T (r1=15, r2=101), 1.5 T (r1=7.4,
r2=95), and 3 T (r1=3.3, r2=160) and the range of contrast
concentrations by a mathematical simulation. Relaxivities of r1 and r2
(L mmol-1 Sec-1) were obtained from a previous study and the selected
concentrations were 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5,
0.6, 0.7, 0.8, 0.9, 1.0, 2.0, and 3.0 mmol/L. T2-weighted images were
simulated using TR/TE ratio as 2000 ms /100 ms. According to the
reference literature, with increasing magnetic field strengths, the
r1 relaxivity tends to decrease while the r2 did not show any
systematic relationship with the selected field strengths. In parallel,
this study results revealed that the signal intensity of Resovist at lower
concentrations tends to increase than the higher concentrations. The
highest reported signal intensity was observed in the low field strength
of 0.47 T. The maximum signal intensities for 0.47 T, 1.5 T and 3 T
were found at the concentration levels of 0.05, 0.06 and 0.05 mmol/L,
respectively. Furthermore, it was revealed that, the concentrations
higher than the above, the signal intensity was decreased
exponentially. An inverse relationship can be found between the field
strength and T2 relaxation time, whereas, the field strength was
increased, T2 relaxation time was decreased accordingly. However,
resulted T2 relaxation time was not significantly different between
0.47 T and 1.5 T in this study. Moreover, a linear correlation of
transverse relaxation rates (1/T2, s–1) with the concentrations of
Resovist can be observed. According to these results, it can conclude
that the concentration of SPIO nanoparticle contrast agents and the
field strengths of MRI are two important parameters which can affect the signal intensity of T2-weighted SE sequence. Therefore, when MR
imaging those two parameters should be considered prudently.