Abstract: We present a low frequency watermarking method
adaptive to image content. The image content is analyzed and
properties of HVS are exploited to generate a visual mask of the
same size as the approximation image. Using this mask we embed the
watermark in the approximation image without degrading the image
quality. Watermark detection is performed without using the original
image. Experimental results show that the proposed watermarking
method is robust against most common image processing operations,
which can be easily implemented and usually do not degrade the
image quality.
Abstract: In recent years demolished concrete waste handling and management is the new primary challenging issue faced by the countries all over the world. It is very challenging and hectic problem that has to be tackled in an indigenous manner, it is desirable to completely recycle demolished concrete waste in order to protect natural resources and reduce environmental pollution. In this research paper an experimental study is carried out to investigate the feasibility and recycling of demolished waste concrete for new construction. The present investigation to be focused on recycling demolished waste materials in order to reduce construction cost and resolving housing problems faced by the low income communities of the world. The crushed demolished concrete wastes is segregated by sieving to obtain required sizes of aggregate, several tests were conducted to determine the aggregate properties before recycling it into new concrete. This research shows that the recycled aggregate that are obtained from site make good quality concrete. The compressive strength test results of partial replacement and full recycled aggregate concrete and are found to be higher than the compressive strength of normal concrete with new aggregate.
Abstract: Shape memory alloy (SMA) actuators have found a
wide range of applications due to their unique properties such as high
force, small size, lightweight and silent operation. This paper presents
the development of compact (SMA) actuator and cooling system in
one unit. This actuator is developed for multi-fingered hand. It
consists of nickel-titanium (Nitinol) SMA wires in compact forming.
The new arrangement insulates SMA wires from the human body by
housing it in a heat sink and uses a thermoelectric device for rejecting
heat to improve the actuator performance. The study uses
optimization methods for selecting the SMA wires geometrical
parameters and the material of a heat sink. The experimental work
implements the actuator prototype and measures its response.
Abstract: Current OCR technology does not allow to
accurately recognizing small text images, such as those found
in web images. Our goal is to investigate new approaches to
recognize very low resolution text images containing antialiased
character shapes.
This paper presents a preliminary study on the variability of
such characters and the feasibility to discriminate them by
using geometrical features. In a first stage we analyze the
distribution of these features. In a second stage we present a
study on the discriminative power for recognizing isolated
characters, using various rendering methods and font
properties. Finally we present interesting results of our
evaluation tests leading to our conclusion and future focus.
Abstract: The ability of the brain to organize information and generate the functional structures we use to act, think and communicate, is a common and easily observable natural phenomenon. In object-oriented analysis, these structures are represented by objects. Objects have been extensively studied and documented, but the process that creates them is not understood. In this work, a new class of discrete, deterministic, dissipative, host-guest dynamical systems is introduced. The new systems have extraordinary self-organizing properties. They can host information representing other physical systems and generate the same functional structures as the brain does. A simple mathematical model is proposed. The new systems are easy to simulate by computer, and measurements needed to confirm the assumptions are abundant and readily available. Experimental results presented here confirm the findings. Applications are many, but among the most immediate are object-oriented engineering, image and voice recognition, search engines, and Neuroscience.
Abstract: Five crystal modifications of water insoluble
artesunate were generated by recrystallizing it from various solvents
with improved physicochemical properties. These generated crystal
forms were characterized to select the most potent and soluble form.
SEM of all the forms showed changes in external shape leading them
to be different morphologically. DSC thermograms of Form III and
Form V showed broad endotherm peaks at 83.04oC and 76.96oC prior
to melting fusion of drug respectively. Calculated weight loss in TGA
revealed that Form III and Form V are methanol and acetone solvates
respectively. However, few additional peaks were appeared in XRPD
pattern in these two solvate forms. All forms exhibit exothermic
behavior in buffer and two solvates display maximum ease of
molecular release from the lattice. Methanol and acetone solvates
were found to be most soluble forms and exhibited higher
antimalarial efficacy showing higher survival rate (83.3%) after 30
days.
Abstract: Support vector regression (SVR) has been regarded
as a state-of-the-art method for approximation and regression. The
importance of kernel function, which is so-called admissible support
vector kernel (SV kernel) in SVR, has motivated many studies
on its composition. The Gaussian kernel (RBF) is regarded as a
“best" choice of SV kernel used by non-expert in SVR, whereas
there is no evidence, except for its superior performance on some
practical applications, to prove the statement. Its well-known that
reproducing kernel (R.K) is also a SV kernel which possesses many
important properties, e.g. positive definiteness, reproducing property
and composing complex R.K by simpler ones. However, there are a
limited number of R.Ks with explicit forms and consequently few
quantitative comparison studies in practice. In this paper, two R.Ks,
i.e. SV kernels, composed by the sum and product of a translation
invariant kernel in a Sobolev space are proposed. An exploratory
study on the performance of SVR based general R.K is presented
through a systematic comparison to that of RBF using multiple
criteria and synthetic problems. The results show that the R.K is
an equivalent or even better SV kernel than RBF for the problems
with more input variables (more than 5, especially more than 10) and
higher nonlinearity.
Abstract: The objective of this research was to find the diffusion properties of vehicles on the road by using the V-Sphere Code. The diffusion coefficient and the size of the height of the wake were estimated with the LES option and the third order MUSCL scheme. We evaluated the code with the changes in the moments of Reynolds Stress along the mean streamline. The results show that at the leading part of a bluff body the LES has some advantages over the RNS since the changes in the strain rates are larger for the leading part. We estimated that the diffusion coefficient with the computed Reynolds stress (non-dimensional) was about 0.96 times the mean velocity.
Abstract: As in today's semiconductor industries test costs can make up to 50 percent of the total production costs, an efficient test error detection becomes more and more important. In this paper, we present a new machine learning approach to test error detection that should provide a faster recognition of test system faults as well as an improved test error recall. The key idea is to learn a classifier ensemble, detecting typical test error patterns in wafer test results immediately after finishing these tests. Since test error detection has not yet been discussed in the machine learning community, we define central problem-relevant terms and provide an analysis of important domain properties. Finally, we present comparative studies reflecting the failure detection performance of three individual classifiers and three ensemble methods based upon them. As base classifiers we chose a decision tree learner, a support vector machine and a Bayesian network, while the compared ensemble methods were simple and weighted majority vote as well as stacking. For the evaluation, we used cross validation and a specially designed practical simulation. By implementing our approach in a semiconductor test department for the observation of two products, we proofed its practical applicability.
Abstract: The introduction of sowing technologies into minimum- or no-tillage soil has a number of economical and environmental virtues, such as improving soil properties, decreasing soil erosion and degradation, and saving working time and fuel. However, the main disadvantage of these technologies is that plant residues on the soil surface reduce the quality of the planted crop seeds, thus requiring plant residues to be removed or cut. This paper presents a analysis of disc coulter parameters and an experimental investigation of cutting spring barley straw containing various amounts of moisture with different disc coulters (smooth and notched).
Abstract: Tensile armour wires provide a flexible pipe's
resistance to longitudinal stresses. Flexible pipe manufacturers need
to know the effect of defects such as scratches and cracks, with
dimensions less than 0.2mm which is the limit of the current nondestructive
detection technology, on the fracture stress and fracture
strain of the wire for quality assurance purposes. Recent research
involving the determination of the fracture strength of cracked wires
employed laboratory testing and classical fracture mechanics
approach using non-standardised fracture mechanics specimens
because standard test specimens could not be manufactured from the
wires owing to their sizes. In this work, the effect of miniature
cracks on the fracture properties of tensile armour wires was
investigated using laboratory and finite element tensile testing
simulations with the phenomenological shear fracture model. The
investigation revealed that the presence of cracks shallower than
0.2mm is worse on the fracture strain of the wire.
Abstract: RC4 was used as an encryption algorithm in WEP(Wired Equivalent Privacy) protocol that is a standardized for 802.11 wireless network. A few attacks followed, indicating certain weakness in the design. In this paper, we proposed a new variant of RC4 stream cipher. The new version of the cipher does not only appear to be more secure, but its keystream also has large period, large complexity and good statistical properties.
Abstract: The removal of hydrogen sulphide is required for reasons of health, odour problems, safety and corrosivity problems. The means of removing hydrogen sulphide mainly depend on its concentration and kind of medium to be purified. The paper deals with a method of hydrogen sulphide removal from the air by its catalytic oxidation to elemental sulphur with the use of Fe-EDTA complex. The possibility of obtaining fibrous filtering materials able to remove small concentrations of H2S from the air were described. The base of these materials is fibrous ion exchanger with Fe(III)- EDTA complex immobilized on their functional groups. The complex of trivalent iron converts hydrogen sulphide to elemental sulphur. Bivalent iron formed in the reaction is oxidized by the atmospheric oxygen, so complex of trivalent iron is continuously regenerated and the overall process can be accounted as pseudocatalytic. In the present paper properties of several fibrous catalysts based on ion exchangers with different chemical nature (weak acid,weak base and strong base) were described. It was shown that the main parameters affecting the process of catalytic oxidation are:concentration of hydrogen sulphide in the air, relative humidity of the purified air, the process time and the content of Fe-EDTA complex in the fibres. The data presented show that the filtering layers with anion exchange package are much more active in the catalytic processes of hydrogen sulphide removal than cation exchanger and inert materials. In the addition to the nature of the fibres relative air humidity is a critical factor determining efficiency of the material in the air purification from H2S. It was proved that the most promising carrier of the Fe-EDTA catalyst for hydrogen sulphide oxidation are Fiban A-6 and Fiban AK-22 fibres.
Abstract: In this research, CaO-ZnO catalysts (with various
Ca:Zn atomic ratios of 1:5, 1:3, 1:1, and 3:1) prepared by incipientwetness
impregnation (IWI) and co-precipitation (CP) methods were
used as a catalyst in the transesterification of palm oil with methanol
for biodiesel production. The catalysts were characterized by several
techniques, including BET method, CO2-TPD, and Hemmett
Indicator. The effects of precursor concentration, and calcination
temperature on the catalytic performance were studied under reaction
conditions of a 15:1 methanol to oil molar ratio, 6 wt% catalyst,
reaction temperature of 60°C, and reaction time of 8 h. At Ca:Zn
atomic ratio of 1:3 gave the highest FAME value owing to a basic
properties and surface area of the prepared catalyst.
Abstract: This paper reports the results of an experimental work
conducted to investigate the effect of curing conditions on the
compressive strength of self-compacting geopolymer concrete
prepared by using fly ash as base material and combination of sodium
hydroxide and sodium silicate as alkaline activator. The experiments
were conducted by varying the curing time and curing temperature in
the range of 24-96 hours and 60-90°C respectively. The essential
workability properties of freshly prepared Self-compacting
Geopolymer concrete such as filling ability, passing ability and
segregation resistance were evaluated by using Slump flow,
V-funnel, L-box and J-ring test methods. The fundamental
requirements of high flowability and resistance to segregation as
specified by guidelines on Self-compacting Concrete by EFNARC
were satisfied. Test results indicate that longer curing time and curing
the concrete specimens at higher temperatures result in higher
compressive strength. There was increase in compressive strength
with the increase in curing time; however increase in compressive
strength after 48 hours was not significant. Concrete specimens cured
at 70°C produced the highest compressive strength as compared to
specimens cured at 60°C, 80°C and 90°C.
Abstract: Dual phase steels (DPS)s have a microstructure
consisting of a hard second phase called Martensite in the soft Ferrite
matrix. In recent years, there has been interest in dual-phase steels,
because the application of these materials has made significant usage;
particularly in the automotive sector Composite microstructure of
(DPS)s exhibit interesting characteristic mechanical properties such
as continuous yielding, low yield stress to tensile strength
ratios(YS/UTS), and relatively high formability; which offer
advantages compared with conventional high strength low alloy
steels(HSLAS). The research dealt with the characterization of
damage in (DPS)s. In this study by review the mechanisms of failure
due to volume fraction of martensite second phase; a new method is
introduced to identifying the mechanisms of failure in the various
phases of these types of steels. In this method the acoustic emission
(AE) technique was used to detect damage progression. These failure
mechanisms consist of Ferrite-Martensite interface decohesion and/or
martensite phase fracture. For this aim, dual phase steels with
different volume fraction of martensite second phase has provided by
various heat treatment methods on a low carbon steel (0.1% C), and
then AE monitoring is used during tensile test of these DPSs. From
AE measurements and an energy ratio curve elaborated from the
value of AE energy (it was obtained as the ratio between the strain
energy to the acoustic energy), that allows detecting important
events, corresponding to the sudden drops. These AE signals events
associated with various failure mechanisms are classified for ferrite
and (DPS)s with various amount of Vm and different martensite
morphology. It is found that AE energy increase with increasing Vm.
This increasing of AE energy is because of more contribution of
martensite fracture in the failure of samples with higher Vm. Final
results show a good relationship between the AE signals and the
mechanisms of failure.
Abstract: The dental composites are preferably used as filling
materials due to their esthetic appearances. Nevertheless one of the
major problems, during the application of the dental composites, is
shape change named as “polymerisation shrinkage" affecting clinical
success of the dental restoration while photo-polymerisation.
Polymerisation shrinkage of composites arises basically from the
formation of a polymer due to the monomer transformation which
composes of an organic matrix phase. It was sought, throughout this
study, to detect and evaluate the structural polymerisation shrinkage
of prepared dental composites in order to optimize the effects of
various fillers included in hydroxyapatite (HA)-reinforced dental
composites and hence to find a means to modify the properties of
these dental composites prepared with defined parameters. As a
result, the shrinkage values of the experimental dental composites
were decreased by increasing the filler content of composites and the
composition of different fillers used had effect on the shrinkage of
the prepared composite systems.
Abstract: Aluminothermic rail welding was from the beginning
a great success because its low price even in 1895 in Germany. This
method is now, widely used all over the world for the railways
construction, maintenance and modernization. Instructions give you
guidelines for preparing papers for conferences or journals.
After 1989, the welding needs of the potentials beneficiaries
(Romanian Railways, Urban Transportation Companies) keep raise
because of the railways maintenance and modernization necessity.
The main materials that determine the Thermit (T) composition
result from manufacturing scraps all over the country. This can help
the environment by consuming these scraps.
The Romanian need for alumino-thermic welding is now by 11300
per year, and in a favourable economical environment, this amount
can reach 30000 units.
This paper tries to show the effect of two types of modifiers
introduced in the T composition on the structure and properties of an
alumino-thermic welding.
Abstract: There is growing interest in biodiesel (fatty acid
methyl ester or FAME) because of the similarity in its properties
when compared to those of diesel fuels. Diesel engines operated on
biodiesel have lower emissions of carbon monoxide, unburned
hydrocarbons, particulate matter, and air toxics than when operated
on petroleum-based diesel fuel. Production of fatty acid methyl ester
(FAME) from rapeseed (nonedible oil) fatty acid distillate having
high free fatty acids (FFA) was investigated in this work. Conditions
for esterification process of rapeseed oil were 1.8 % H2SO4 as
catalyst, MeOH/oil of molar ratio 2 : 0.1 and reaction temperature
65 °C, for a period of 3h. The yield of methyl ester was > 90 % in 1
h.
The amount of FFA was reduced from 93 wt % to less than 2 wt %
at the end of the esterification process. The FAME was pureed by
neutralization with 1 M sodium hydroxide in water solution at a
reaction temperature of 62 °C. The final FAME product met with the
biodiesel quality standard, and ASTM D 6751.
Abstract: This research investigates the suitability of fuel oil in
improving gypseous soil. A detailed laboratory tests were carried-out
on two soils (soil I with 51.6% gypsum content, and soil II with
26.55%), where the two soils were obtained from Al-Therthar site
(Al-Anbar Province-Iraq).
This study examines the improvement of soil properties using the
gypsum material which is locally available with low cost to minimize
the effect of moisture on these soils by using the fuel oil. This study
was conducted on two models of the soil gypsum, from the Tharthar
area. The first model was sandy soil with Gypsum content of (51.6%)
and the second is clayey soil and the content of Gypsum is (26.55%).
The program included tests measuring the permeability and
compressibility of the soil and their collapse properties. The shear
strength of the soil and the amounts of weight loss of fuel oil due to
drying had been found. These tests have been conducted on the
treated and untreated soils to observe the effect of soil treatment on
the engineering properties when mixed with varying degrees of fuel
oil with the equivalent of the water content.
The results showed that fuel oil is a good material to modify the
basic properties of the gypseous soil of collapsibility and
permeability, which are the main problems of this soil and retained
the soil by an appropriate amount of the cohesion suitable for
carrying the loads from the structure.