Abstract: Representation and description of object shapes by the
slopes of their contours or borders are proposed. The idea is to capture
the essence of the features that make it easier for a shape to be
stored, transmitted, compared and recognized. These features must
be independent of translation, rotation and scaling of the shape. A
approach is proposed to obtain high performance, efficiency and to
merge the boundaries into sequence of straight line segments with
the fewest possible segments. Evaluation on the performance of the
proposed method is based on its comparison with established method
of object shape description.
Abstract: Protection of slope and embankment from erosion has
become an important issue in Bangladesh. The constructions of
strong structures require large capital, integrated designing, high
maintenance cost. Strong structure methods have negative impact on
the environment and sometimes not function for the design period.
Plantation of vetiver system along the slopes is an alternative
solution. Vetiver not only serves the purpose of slope protection but
also adds green environment reducing pollution. Vetiver is available
in almost all the districts of Bangladesh. This paper presents the
application of vetiver system with geo-jute, for slope protection and
erosion control of embankments and slopes. In-situ shear tests have
been conducted on vetiver rooted soil system to find the shear
strength. The shear strength and effective soil cohesion of vetiver
rooted soil matrix are respectively 2.0 times and 2.1 times higher than
that of the bared soil. Similar trends have been found in direct shear
tests conducted on laboratory reconstituted samples. Field trials have
been conducted in road embankment and slope protection with
vetiver at different sites. During the time of vetiver root growth the
soil protection has been accomplished by geo-jute. As the geo-jute
degrades with time, vetiver roots grow and take over the function of
geo-jutes. Slope stability analyses showed that vegetation increase
the factor of safety significantly.
Abstract: The theory of Groebner Bases, which has recently been
honored with the ACM Paris Kanellakis Theory and Practice Award,
has become a crucial building block to computer algebra, and is
widely used in science, engineering, and computer science. It is wellknown
that Groebner bases computation is EXP-SPACE in a general
polynomial ring setting.
However, for many important applications in computer science
such as satisfiability and automated verification of hardware and
software, computations are performed in a Boolean ring. In this paper,
we give an algorithm to show that Groebner bases computation is PSPACE
in Boolean rings. We also show that with this discovery,
the Groebner bases method can theoretically be as efficient as
other methods for automated verification of hardware and software.
Additionally, many useful and interesting properties of Groebner
bases including the ability to efficiently convert the bases for different
orders of variables making Groebner bases a promising method in
automated verification.
Abstract: In contrast to conventional generators, self-excited induction generators are found to be most suitable machines for wind energy conversion in remote and windy areas due to many advantages over grid connected machines. This papers presents a Self-Excited Induction Generator (SEIG) driven by wind turbine and supplying an induction motor which is coupled to a centrifugal pump. A method to describe the steady state performance based on nodal analysis is presented. Therefore the advanced knowledge of the minimum excitation capacitor value is required. The effects of variation of excitation capacitance on system and rotor speed under different loading conditions have been analyzed and considered to optimize induction motor pump performances.
Abstract: The major focus of this work was to characterize hydrodynamics in a packed-bed with and without static mixer by using Computational Fluid Dynamic (CFD). The commercial software: COMSOL MULTIPHYSICSTM Version 3.3 was used to simulate flow fields of mixed-gas reactants i.e. CO and H2. The packed-bed was a single tube with the inside diameter of 0.8 cm and the length of 1.2 cm. The static mixer was inserted inside the tube. The number of twisting elements was 1 with 0.8 cm in diameter and 1.2 cm in length. The packed-bed with and without static mixer were both packed with approximately 700 spherical structures representing catalyst pellets. Incompressible Navier-Stokes equations were used to model the gas flow inside the beds at steady state condition, in which the inlet Reynolds Number (Re) was 2.31. The results revealed that, with the insertion of static mixer, the gas was forced to flow radially inward and outward between the central portion of the tube and the tube wall. This could help improving the overall performance of the packed-bed, which could be utilized for heterogeneous catalytic reaction such as reforming and Fischer- Tropsch reactions.
Abstract: The copper flotation tailings from Konkola Copper
mine in Nchanga, Zambia were used in the study. The purpose of this
study was to determine the leaching characteristics of the tailings
material prior and after the physical beneficiation process is
employed. The Knelson gravity concentrator (KC-MD3) was used for
the beneficiation process. The copper leaching efficiencies and
impurity co-extraction percentages in both the upgraded and the raw
feed material were determined at different pH levels and temperature.
It was observed that the copper extraction increased with an increase
in temperature and a decrease in pH levels. In comparison to the raw
feed sample, the upgraded sample reported a maximum copper
extraction of 69% which was 9%, higher than raw feed % extractions.
The impurity carry over was reduced from 18% to 4 % on the
upgraded sample. The reduction in impurity co-extraction was as a
result of the removal of the reactive gangue elements during the
upgrading process, this minimized the number of side reaction
occurring during leaching.
Abstract: In this paper, FinFET devices are analyzed with
emphasis on sub-threshold leakage current control. This is achieved
through proper biasing of the back gate, and through the use of
asymmetric work functions for the four terminal FinFET devices. We
are also examining different configurations of multiplexers and XOR
gates using transistors of symmetric and asymmetric work functions.
Based on extensive characterization data for MUX circuits, our
proposed configuration using symmetric devices lead to leakage
current and delay improvements of 65% and 47% respectively
compared to results in the literature. For XOR gates, a 90%
improvement in the average leakage current is achieved by using
asymmetric devices. All simulations are based on a 25nm FinFET
technology using the University of Florida UFDG model.
Abstract: A DC-to-DC converter for applications involving a
source with widely varying voltage conditions with loads requiring
constant voltage from full load down to no load is presented.
The switching regulator considered is a Buck converter with Pulse
Skipping Modulation control whereby pulses applied to the switch
are blocked or released on output voltage crossing a predetermined
value. Results of the study on the performance of regulator circuit
are presented. The regulator regulates over a wide input voltage range
with slightly higher ripple content and good transient response. Input
current spectrum indicates a good EMI performance with crowding
of components at low frequency range.
Abstract: Sinc-collocation scheme is one of the new techniques
used in solving numerical problems involving integral equations. This
method has been shown to be a powerful numerical tool for finding
fast and accurate solutions. So, in this paper, some properties of the
Sinc-collocation method required for our subsequent development
are given and are utilized to reduce integral equation of the first
kind to some algebraic equations. Then convergence with exponential
rate is proved by a theorem to guarantee applicability of numerical
technique. Finally, numerical examples are included to demonstrate
the validity and applicability of the technique.
Abstract: Calcium [Ca2+] dynamics is studied as a potential form
of neuron excitability that can control many irregular processes like
metabolism, secretion etc. Ca2+ ion enters presynaptic terminal and
increases the synaptic strength and thus triggers the neurotransmitter
release. The modeling and analysis of calcium dynamics in neuron
cell becomes necessary for deeper understanding of the processes
involved. A mathematical model has been developed for cylindrical
shaped neuron cell by incorporating physiological parameters like
buffer, diffusion coefficient, and association rate. Appropriate initial
and boundary conditions have been framed. The closed form solution
has been developed in terms of modified Bessel function. A computer
program has been developed in MATLAB 7.11 for the whole
approach.
Abstract: In this paper, the effect of transmission codes on the
performance of coherent square M-ary quadrature amplitude
modulation (CSMQAM) under hybrid selection/maximal-ratio
combining (H-S/MRC) diversity is analysed. The fading channels are
modeled as frequency non-selective slow independent and identically
distributed Rayleigh fading channels corrupted by additive white
Gaussian noise (AWGN). The results for coded MQAM are
computed numerically for the case of (24,12) extended Golay code
and compared with uncoded MQAM under H-S/MRC diversity by
plotting error probabilities versus average signal to noise ratio (SNR)
for various values L and N in order to examine the improvement in
the performance of the digital communications system as the number
of selected diversity branches is increased. The results for no
diversity, conventional SC and Lth order MRC schemes are also
plotted for comparison. Closed form analytical results derived in this
paper are sufficiently simple and therefore can be computed
numerically without any approximations. The analytical results
presented in this paper are expected to provide useful information
needed for design and analysis of digital communication systems
over wireless fading channels.
Abstract: There are two major variants of the Simplex
Algorithm: the revised method and the standard, or tableau method.
Today, all serious implementations are based on the revised method
because it is more efficient for sparse linear programming problems.
Moreover, there are a number of applications that lead to dense linear
problems so our aim in this paper is to present some computational
results on parallel implementation of dense Simplex Method. Our
implementation is implemented on a SMP cluster using C
programming language and the Message Passing Interface MPI.
Preliminary computational results on randomly generated dense
linear programs support our results.
Abstract: In the past 20 years the economy of the Czech
Republic has experienced substantial changes. In the 1990s the
development was affected by the transformation which sought to
establish the right conditions for privatization and creation of
elementary market relations. In the last decade the characteristic
elements such as private ownership and corresponding institutional
framework have been strengthened. This development was marked by
the accession of the Czech Republic to the EU. The Czech Republic
is striving to reduce the difference between its level of economic
development and the quality of institutional framework in
comparison with other developed countries. The process of finding
the adequate solutions has been hampered by the negative impact of
the world financial crisis on the Czech Republic and the standard of
living of its inhabitants. This contribution seeks to address the
question of whether and to which extent the economic development
of the transitive Czech economy is affected by the change in
behaviour of households and their tendency to consumption, i.e. in
the sense of reduction or increase in demand for goods and services.
It aims to verify whether the increasing trend of household
indebtedness and decreasing trend of saving pose a significant risk in
the Czech Republic. At a general level the analysis aims to contribute
to finding an answer to the question of whether the debt increase of
Czech households is connected to the risk of "eating through" the
borrowed money and whether Czech households risk falling into a
debt trap. In addition to household indebtedness risks in the Czech
Republic the analysis will focus on identification of specifics of the
transformation phase of the Czech economy in comparison with the
EU countries, or selected OECD countries.
Abstract: P16/INK4A is tumor suppressor protein that plays a critical role in cell cycle regulation. Loss of P16 protein expression has been implicated in pathogenesis of many cancers, including lymphoma. Therefore, we sought to investigate if loss of P16 protein expression is associated with lymphoma and/or any specific lymphoma subtypes (Hodgkin-s lymphoma (HL) and nonHodgkin-s lymphoma (NHL)). Fifty-five lymphoma cases consisted of 30 cases of HL and 25 cases of NHL, with an age range of 3 to 78 years, were examined for loss of P16 by immunohistochemical technique using a specific antibody reacting against P16. In total, P16 loss was seen in 33% of all lymphoma cases. P16 loss was identified in 47.7% of HL cases. In contrast, only 16% of NHL showed loss of P16. Loss of P16 was seen in 67% of HL patients with 50 years of age or older, whereas P16 loss was found in only 42% of HL patients with less than 50 years of age. P16 loss in HL is somewhat higher in male (55%) than in female (30%). In subtypes of HL, P16 loss was found exclusively in all cases of lymphocyte depletion, lymphocyte predominance and unclassified cases, whereas P16 loss was seen in 39% of mixed cellularity and 29% of nodular sclerosis cases. In low grade NHL patients, P16 loss was seen in approximately one-third of cases, whereas no or very rare of P16 loss was found in intermediate and high grade cases. P16 loss did not show any correlation with age or gender of NHL patients. In conclusion, the high rate of P16 loss seen in our study suggests that loss of P16 expression plays a critical role in the pathogenesis of lymphoma, particularly with HL.
Abstract: this paper focuses on designing of PSS and SVC
controller based on chaos and PSO algorithms to improve the
stability of power system. Single machine infinite bus (SMIB) system
with SVC located at the terminal of generator has been considered to
evaluate the proposed controllers where both SVC and PSS have the
same controller. The coefficients of PSS and SVC controller have
been optimized by chaos and PSO algorithms. Finally the system
with proposed controllers has been simulated for the special
disturbance in input power of generator, and then the dynamic
responses of generator have been presented. The simulation results
showed that the system composed with recommended controller has
outstanding operation in fast damping of oscillations of power system.
Abstract: Nodes in mobile Ad Hoc Network (MANET) do not
rely on a central infrastructure but relay packets originated by other
nodes. Mobile ad hoc networks can work properly only if the
participating nodes collaborate in routing and forwarding. For
individual nodes it might be advantageous not to collaborate, though.
In this conceptual paper we propose a new approach based on
relationship among the nodes which makes them to cooperate in an
Adhoc environment. The trust unit is used to calculate the trust
values of each node in the network. The calculated trust values are
being used by the relationship estimator to determine the relationship
status of nodes. The proposed enhanced protocol was compared with
the standard DSR protocol and the results are analyzed using the
network simulator-2.
Abstract: Nonlinear solitary structures of electron plasma waves
have been investigated by using nonlinear quantum fluid equations for electrons with an arbitrary temperature. It is shown that the electron degeneracy parameter has significant effects on the linear and nonlinear properties of electron plasma waves. Depending on its
value both compressive and rarefactive solitons can be excited in the model plasma under consideration.
Abstract: This paper presents a cold chain monitoring system which focuses on assessment of quality and dynamic pricing information about food in cold chain. Cold chain is composed of many actors and stages; however it can be seen as a single entity since a breakdown in temperature control at any stage can impact the final quality of the product. In a cold chain, the shelf life, quality, and safety of perishable food throughout the supply chain is greatly impacted by environmental factors especially temperature. In this paper, a prototype application is implemented to retrieve timetemperature history, the current quality and the dynamic price setting according to changing quality impacted by temperature fluctuations in real-time.
Abstract: Bentonitic material from South Aswan, Egypt was evaluated in terms of mineral-ogy and chemical composition as bleaching clay in refining of transformer oil before and after acid activation and thermal treatment followed by acid leaching using HCl and H2SO4 for different contact times. Structural modification and refining power of bento-nite were investigated during modification by means of X-ray diffraction and infrared spectroscopy. The results revealed that the activated bentonite could be used for refining of transformer oil. The oil parameters such as; dielectric strength, viscosity and flash point had been improved. The dielectric breakdown strength of used oil increased from 29 kV for used oil treated with unactivated bentonite to 74 kV after treatment with activated bentonite. Kinematic Viscosity changed from 19 to 11 mm2 /s after treatment with activated bentonite. However, flash point achieved 149 ºC.
Abstract: In this study, hydrogels consisted of polyvinyl alcohol,
propylene glycol and β-glucan were developed by radiation technique
for wound dressing. The prepared hydrogels were characterized by
examining of physical properties such as gel fraction and absorption
ratio. The gel fraction and absorption ratio were dependent on the
crosslinking density. On observing the wound healing of rat skin, the
resulting hydrogels accelerated the wound healing comparing to cotton
gauze. Therefore, the PVA/propylene glycol/β-glucan blended
hydrogels can greatly accelerate the healing without causing irritation.