Abstract: In [4], Kipnis and Shamir have cryptanalised
a version of HFE of degree 2. In this paper, we describe the
generalization of this attack of HFE of degree more than 2.
We are based on Fourier Transformation to acheive partially
this attack.
Abstract: In the present work, we have developed a symmetric electrochemical capacitor based on the nanostructured iron oxide (Fe3O4)-activated carbon (AC) nanocomposite materials. The physical properties of the nanocomposites were characterized by Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances of the composite electrode in 1.0 M Na2SO3 and 1.0 M Na2SO4 aqueous solutions were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The composite electrode with 4 wt% of iron oxide nanomaterials exhibits the highest capacitance of 86 F/g. The experimental results clearly indicate that the incorporation of iron oxide nanomaterials at low concentration to the composite can improve the capacitive performance, mainly attributed to the contribution of the pseudocapacitance charge storage mechanism and the enhancement on the effective surface area of the electrode. Nevertheless, there is an optimum threshold on the amount of iron oxide that needs to be incorporated into the composite system. When this optimum threshold is exceeded, the capacitive performance of the electrode starts to deteriorate, as a result of the undesired particle aggregation, which is clearly indicated in the SEM analysis. The electrochemical performance of the composite electrode is found to be superior when Na2SO3 is used as the electrolyte, if compared to the Na2SO4 solution. It is believed that Fe3O4 nanoparticles can provide favourable surface adsorption sites for sulphite (SO3 2-) anions which act as catalysts for subsequent redox and intercalation reactions.
Abstract: In this study, a 3D combustion chamber was simulated
using FLUENT 6.32. Aim to obtain detailed information on
combustion characteristics and _ nitrogen oxides in the furnace and
the effect of oxygen enrichment in a combustion process. Oxygenenriched
combustion is an effective way to reduce emissions. This
paper analyzes NO emission, including thermal NO and prompt NO.
Flow rate ratio of air to fuel is varied as 1.3, 3.2 and 5.1 and the
oxygen enriched flow rates are 28, 54 and 68 lit/min. The 3D
Reynolds Averaged Navier Stokes (RANS) equations with standard
k-ε turbulence model are solved together by Fluent 6.32 software.
First order upwind scheme is used to model governing equations and
the SIMPLE algorithm is used as pressure velocity coupling. Results
show that for AF=1.3, increase the oxygen flow rate of oxygen
reduction in NO emissions is Lance. Moreover, in a fixed oxygen
enrichment condition, increasing the air to fuel ratio will increase the
temperature peak, but not the NO emission rate. As a result, oxygen
enrichment can reduce the NO emission at this kind of furnace in low
air to fuel rates.
Abstract: The architecture of Safavid Dynasty can be considered the epitome of Iranian architectural beauty. Safavid dynasty (1501- 1722 AC) along with Ottoman in Turkey and Mughal Empire in India were the three great Islamic nations of their time (1500 AC) often known as the last Islamic countries with international authority up to the 20th Century. This era approximately coincide with Renaissance in Europe. In this era, large European countries begin amassing power thanks to significant scientific, cultural and religious revolutions of that time and colonizing nations such as England, Spain and Portugal began to influence international trends with in an increasing while other non-industrial nations diminished. The main objective of this paper is to give a typological overview of the development of decoration and ornament in the architecture of Safafid Dynasty in Iran. It is expected that it can start a wider discussion to enrich this nation-s heritage and contribute to the development of Islamic ornament in general.
Abstract: This study investigated the ecological effects of
particulate pollution from a cement factory on the vegetation in the
western Mediterranean coastal desert of Egypt. Variations in
vegetation, soil chemical characters, and some responses of Atriplex
halimus, as a dominant species in the study area, were investigated in
some sites located in different directions from the cement factory
between Burg El-Arab in the east and El-Hammam in the west. The
results showed an obvious decrease in vegetation diversity, in
response to cement-kiln dust pollution, that accompanied by a high
dominance attributed to the high contribution of Atriplex halimus.
Annual species were found to be more sensitive to cement dust
pollution as they all failed to persist in highly disturbed sites. It is
remarkable that cover and phytomass of Atriplex halimus were
increased greatly in response to cement dust pollution, and this was
accompanied by a reduction in the mature seeds and leaf-area of the
plant. The few seeds of the affected individuals seemed to be more
fertile and attained higher germination percentages and exhibited
hardening against drought stress.
Abstract: The paper presents a new system for the automat
control of the aircrafts- flight in lateral plane using the cinematic
model and the dynamic inversion. Starting from the equations of the
aircrafts- lateral movement, the authors use two axes systems and
obtained a control law that cancels the lateral deviation of the flying
objects from the runway line. This system makes the aircrafts-
direction angle to follow the direction angle of the runway line.
Simulations in Matlab/Simulink have been done for different
aircraft-s initial points and direction angles. The inconvenience of
this system is the long duration of the “transient regime". That is why
this system can be used independently, but the results are not very
good; thus, it can be a part (subsystem) of other systems. The main
system that cancels the lateral deviation from the runway line is
based on dynamic inversion and uses, as subsystem, the control
system for the lateral movement using the cinematic model. Using
complex Matlab/Simulink models, the authors obtained the time
evolution of the direction angle and the time evolution of the aircraft
lateral deviation with respect to the runway line, for different values
of the initial direction angle and for different wind types. The system
has a very good behavior for all initial direction angles and wind
types.
Abstract: UML is a collection of notations for capturing a software system specification. These notations have a specific syntax defined by the Object Management Group (OMG), but many of their constructs only present informal semantics. They are primarily graphical, with textual annotation. The inadequacies of standard UML as a vehicle for complete specification and implementation of real-time embedded systems has led to a variety of competing and complementary proposals. The Real-time UML profile (UML-RT), developed and standardized by OMG, defines a unified framework to express the time, scheduling and performance aspects of a system. We present in this paper a framework approach aimed at deriving a complete specification of a real-time system. Therefore, we combine two methods, a semiformal one, UML-RT, which allows the visual modeling of a realtime system and a formal one, CSP+T, which is a design language including the specification of real-time requirements. As to show the applicability of the approach, a correct design of a real-time system with hard real time constraints by applying a set of mapping rules is obtained.
Abstract: A new secure knapsack cryptosystem based on the
Merkle-Hellman public key cryptosystem will be proposed in this
paper. Although it is common sense that when the density is low, the
knapsack cryptosystem turns vulnerable to the low-density attack. The
density d of a secure knapsack cryptosystem must be larger than
0.9408 to avoid low-density attack. In this paper, we investigate a
new Permutation Combination Algorithm. By exploiting this
algorithm, we shall propose a novel knapsack public-key cryptosystem.
Our proposed scheme can enjoy a high density to avoid the
low-density attack. The density d can also exceed 0.9408 to avoid
the low-density attack.
Abstract: The risk of water erosion is one of the main
environmental concerns in the southern Mediterranean regions. Thus,
quantification of soil loss is an important issue for soil and water
conservation managers. The objective of this paper is to examine the
applicability of the Soil and Water Assessment Tool (SWAT) model
in The Sarrath river catchment, North of Tunisia, and to identify the
most vulnerable areas in order to help manager implement an
effective management program. The spatial analysis of the results
shows that 7 % of the catchment experiences very high erosion risk,
in need for suitable conservation measures to be adopted on a priority
basis. The spatial distribution of erosion risk classes estimated 3%
high, 5,4% tolerable, and 84,6% low. Among the 27 delineated subcatchments
only 4 sub-catchments are found to be under high and
very high soil loss group, two sub-catchments fell under moderate
soil loss group, whereas other sub-catchments are under low soil loss
group.
Abstract: The scope of this paper is to describe a real electrical
installation of renewable energy using photovoltaic cells. The
displayed power grid connected network was established in 2007 at
area of Northern Greece. The photovoltaic park is composed of 6120
photovoltaic cells able to deliver a total power of 1.101.600 Wp. For
the transformation of DC voltage to AC voltage have been used 25
stand alone three phases inverters and for the connection at the
medium voltage network of Greek Power Authority have been
installed two oil immersed transformer of 630 kVA each one. Due to
the wide space area of installation a specific external lightning
protection system has been designed. Additionally, due to the
sensitive electronics of the control and protection systems of park,
surge protection, equipotent bonding and shielding were also of
major importance.
Abstract: We propose an all optical flip-flop circuit composedof two Silicon-on-insulator microring resonators coupled to straightwaveguides by exploiting the optical bistability behavior due to thenonlinear Kerr effect. We used the transfer matrix analysis toinvestigate continuous wave propagation through microrings, as wellwe considered the nonlinear switching characteristics of an opticaldevice using a double-coupler silicon ring resonator in presence ofthe Kerr nonlinearity, thus obtaining the bistability behavior of theoutput port, the drop port and also inside the silicon microringresonator. It is shown that the bistability behavior depends on thecontrol of the input wavelength.KeywordsAll optical flip-flops, Kerr effect, microringresonator, optical bistability.
Abstract: Bacillus subtilis strain LB5 produced lipopeptide
antibiotic iturin A-2 in liquid medium. Crude extract
from cell-free supernatant of B. subtilis cultivated broth extracted
with n-butanol showed antifungal activity to conidial germination of
Colletotrichum gloeosporioides. The germination of conidia was
completely inhibited by crude extract. The ultrastructure of conidia
after treated with crude extract was found an accumulation of vesiclelike
material between cell wall and plasma membrane while this
accumulation was not observed in untreated and germinated conidia.
Besides, the cell wall was not affected by crude extract.
Abstract: This study carried out to determine the effect of plant
densities on some agronomic characteristics of four safflower cultivars in spring planting. The experiment was conducted at Yazd,
Iran- using a factorial in a randomized complete block design with four replications. Cultivars were including Arak, IL, Asteria and Local and plant densities were 10, 13.3, 20 and 40 plant/m2. Number
of seeds/head, number of heads/plant, HI, 1000-seed weight and seed yield significantly decreased as planting density increased. With increasing planting density, LAI, plant height, first branch height and
biological yield increased. The highest seed yield was obtained in 13.3 plant/m2 (2167 kg/ha). There were significant differences
between cultivars. Local cv. had higher seed yield than the other cultivars mainly due to higher heads/plant and seeds/head.
Abstract: Hydrogen is regarded to play an important role in
future energy systems because it can be produced from abundant
resources and its combustion only generates water. The disposal of
waste tyres is a major problem in environmental management
throughout the world. The use of waste materials as a source of
hydrogen is particularly of interest in that it would also solve a waste
treatment problem. There is much interest in the use of alternative
feedstocks for the production of hydrogen since more than 95% of
current production is from fossil fuels. The pyrolysis of waste tyres
for the production of liquid fuels, activated carbons and gases has
been extensively researched. However, combining pyrolysis with
gasification is a novel process that can gasify the gaseous products
from pyrolysis. In this paper, an experimental investigation into the
production of hydrogen and other gases from the bench scale
pyrolysis-gasification of tyres has been investigated. Experiments
were carried using a two stage system consisting of pyrolysis of the
waste tyres followed by catalytic steam gasification of the evolved
gases and vapours in a second reactor. Experiments were conducted
at a pyrolysis temperature of 500 °C using Ni/Al2O3 as a catalyst. The
results showed that there was a dramatic increase in gas yield and the
potential H2 production when the gasification temperature was
increased from 600 to 900 oC. Overall, the process showed that high
yields of hydrogen can be produced from waste tyres.
Abstract: XML files contain data which is in well formatted manner. By studying the format or semantics of the grammar it will be helpful for fast retrieval of the data. There are many algorithms which describes about searching the data from XML files. There are no. of approaches which uses data structure or are related to the contents of the document. In these cases user must know about the structure of the document and information retrieval techniques using NLPs is related to content of the document. Hence the result may be irrelevant or not so successful and may take more time to search.. This paper presents fast XML retrieval techniques by using new indexing technique and the concept of RXML. When indexing an XML document, the system takes into account both the document content and the document structure and assigns the value to each tag from file. To query the system, a user is not constrained about fixed format of query.
Abstract: Main goal of preventive healthcare problems are at
decreasing the likelihood and severity of potentially life-threatening
illnesses by protection and early detection. The levels of
establishment and staffing costs along with summation of the travel
and waiting time that clients spent are considered as objectives
functions of the proposed nonlinear integer programming model. In
this paper, we have proposed a bi-objective mathematical model for
designing a network of preventive healthcare facilities so as to
minimize aforementioned objectives, simultaneously. Moreover, each
facility acts as M/M/1 queuing system. The number of facilities to be
established, the location of each facility, and the level of technology
for each facility to be chosen are provided as the main determinants
of a healthcare facility network. Finally, to demonstrate performance
of the proposed model, four multi-objective decision making
techniques are presented to solve the model.
Abstract: This paper presents a forgetting factor scheme for variable step-size affine projection algorithms (APA). The proposed scheme uses a forgetting processed input matrix as the projection matrix of pseudo-inverse to estimate system deviation. This method introduces temporal weights into the projection matrix, which is typically a better model of the real error's behavior than homogeneous temporal weights. The regularization overcomes the ill-conditioning introduced by both the forgetting process and the increasing size of the input matrix. This algorithm is tested by independent trials with coloured input signals and various parameter combinations. Results show that the proposed algorithm is superior in terms of convergence rate and misadjustment compared to existing algorithms. As a special case, a variable step size NLMS with forgetting factor is also presented in this paper.
Abstract: Many recent electrophysiological studies have
revealed the importance of investigating meditation state in order to
achieve an increased understanding of autonomous control of
cardiovascular functions. In this paper, we characterize heart rate
variability (HRV) time series acquired during meditation using
nonlinear dynamical parameters. We have computed minimum
embedding dimension (MED), correlation dimension (CD), largest
Lyapunov exponent (LLE), and nonlinearity scores (NLS) from HRV
time series of eight Chi and four Kundalini meditation practitioners.
The pre-meditation state has been used as a baseline (control) state to
compare the estimated parameters. The chaotic nature of HRV during
both pre-meditation and meditation is confirmed by MED. The
meditation state showed a significant decrease in the value of CD and
increase in the value of LLE of HRV, in comparison with premeditation
state, indicating a less complex and less predictable nature
of HRV. In addition, it was shown that the HRV of meditation state
is having highest NLS than pre-meditation state. The study indicated
highly nonlinear dynamic nature of cardiac states as revealed by
HRV during meditation state, rather considering it as a quiescent
state.
Abstract: The theoretical investigation is carried out to describe
the effect of increase of pressure waves amplitude in clean and bubbly liquid. The goal of the work is to capture the regime of multiple magnification of acoustic and shock waves in the liquid,
which enables to get appropriate conditions to enlarge collapses of
micro-bubbles. The influence of boundary conditions and frequency
of the governing acoustic field is studied for the case of the
cylindrical acoustic resonator. It has been observed the formation of
standing waves with large amplitude at resonant frequencies. The
interaction of the compression wave with gas and vapor bubbles is
investigated for the convergent channel. It is shown theoretically that
the chemical reactions, which occur inside gas bubbles, provide additional impulse to the wave, that affect strongly on the collapses
of the vapor bubbles
Abstract: This paper in essence presents comparative
experimental data on the mechanical performance of steel and
synthetic fibre-reinforced concrete under compression, tensile split
and flexure. URW1050 steel fibre and HPP45 synthetic fibre, both
with the same concrete design mix, have been used to make cube
specimens for a compression test, cylinders for a tensile split test and
beam specimens for a flexural test. The experimental data
demonstrated steel fibre reinforced concrete to be stronger in flexure
at early stages, whilst both fibre reinforced concrete types displayed
comparatively the same performance in compression, tensile splitting
and 28-day flexural strength. In terms of post-crack controlHPP45
was preferable.