Abstract: In the Equivalent Transformation (ET) computation
model, a program is constructed by the successive accumulation of
ET rules. A method by meta-computation by which a correct ET
rule is generated has been proposed. Although the method covers a
broad range in the generation of ET rules, all important ET rules
are not necessarily generated. Generation of more ET rules can be
achieved by supplementing generation methods which are specialized
for important ET rules. A Specialization-by-Equation (Speq) rule is
one of those important rules. A Speq rule describes a procedure in
which two variables included in an atom conjunction are equalized
due to predicate constraints. In this paper, we propose an algorithm
that systematically and recursively generate Speq rules and discuss
its effectiveness in the synthesis of ET programs. A Speq rule is
generated based on proof of a logical formula consisting of given
atom set and dis-equality. The proof is carried out by utilizing some
ET rules and the ultimately obtained rules in generating Speq rules.
Abstract: In this paper, a new learning algorithm based on a
hybrid metaheuristic integrating Differential Evolution (DE) and
Reduced Variable Neighborhood Search (RVNS) is introduced to train
the classification method PROAFTN. To apply PROAFTN, values of
several parameters need to be determined prior to classification. These
parameters include boundaries of intervals and relative weights for
each attribute. Based on these requirements, the hybrid approach,
named DEPRO-RVNS, is presented in this study. In some cases, the
major problem when applying DE to some classification problems
was the premature convergence of some individuals to local optima.
To eliminate this shortcoming and to improve the exploration and
exploitation capabilities of DE, such individuals were set to iteratively
re-explored using RVNS. Based on the generated results on
both training and testing data, it is shown that the performance of
PROAFTN is significantly improved. Furthermore, the experimental
study shows that DEPRO-RVNS outperforms well-known machine
learning classifiers in a variety of problems.
Abstract: An experimental study is presented on the effect
of microstructural change on the Portevin-Le Chatelier effect
behaviour of Al-2.5%Mg alloy. Tensile tests are performed on
the as received and heat treated (at 400 ºC for 16 hours)
samples for a wide range of strain rates. The serrations
observed in the stress-time curve are investigated from
statistical analysis point of view. Microstructures of the
samples are characterized by optical metallography and X-ray
diffraction. It is found that the excess vacancy generated due
to heat treatment leads to decrease in the strain rate sensitivity
and the increase in the number of stress drop occurrences per
unit time during the PLC effect. The microstructural
parameters like domain size, dislocation density have no
appreciable effect on the PLC effect as far as the statistical
behavior of the serrations is considered.
Abstract: Because of high ductility, aluminum alloys, have been widely used as an important base of metal forming industries. But the main week point of these alloys is their low strength so in forming them with conventional methods like deep drawing, hydro forming, etc have been always faced with problems like fracture during of forming process. Because of this, recently using of explosive forming method for forming of these plates has been recommended. In this paper free explosive forming of A2024 aluminum alloy is numerically simulated and during it, explosion wave propagation process is studied. Consequences of this simulation can be effective in prediction of quality of production. These consequences are compared with an experimental test and show the superiority of this method to similar methods like hydro forming and deep drawing.
Abstract: Bloom filter is a probabilistic and memory efficient
data structure designed to answer rapidly whether an element is
present in a set. It tells that the element is definitely not in the set but
its presence is with certain probability. The trade-off to use Bloom
filter is a certain configurable risk of false positives. The odds of a
false positive can be made very low if the number of hash function is
sufficiently large. For spam detection, weight is attached to each set
of elements. The spam weight for a word is a measure used to rate the
e-mail. Each word is assigned to a Bloom filter based on its weight.
The proposed work introduces an enhanced concept in Bloom filter
called Bin Bloom Filter (BBF). The performance of BBF over
conventional Bloom filter is evaluated under various optimization
techniques. Real time data set and synthetic data sets are used for
experimental analysis and the results are demonstrated for bin sizes 4,
5, 6 and 7. Finally analyzing the results, it is found that the BBF
which uses heuristic techniques performs better than the traditional
Bloom filter in spam detection.
Abstract: Impurity metals such as manganese and cadmium
from high-tenor cobalt electrolyte solution were selectively removed
by solvent extraction method using Co-D2EHPA after converting the functional group of D2EHPA with Co2+ ions. The process parameters
such as pH, organic concentration, O/A ratio, kinetics etc. were
investigated and the experiments were conducted by batch tests in the laboratory bench scale. Results showed that a significant amount
of manganese and cadmium can be extracted using Co-D2EHPA for the optimum processing of cobalt electrolyte solution at equilibrium pH about 3.5. The McCabe-Thiele diagram, constructed from the
extraction studies showed that 100% impurities can be extracted through four stages for manganese and three stages for cadmium
using O/A ratio of 0.65 and 1.0, respectively. From the stripping study, it was found that 100% manganese and cadmium can be stripped from the loaded organic using 0.4 M H2SO4 in a single
contact. The loading capacity of Co-D2EHPA by manganese and cadmium were also investigated with different O/A ratio as well as
with number of stages of contact of aqueous and organic phases. Valuable information was obtained for the designing of an impurities
removal process for the production of pure cobalt with less trouble in the electrowinning circuit.
Abstract: Preparation of size controlled nano-particles of silver catalyst on carbon substrate from e-waste has been investigated. Chemical route was developed by extraction of the metals available in nitric acid followed by treatment with hydrofluoric acid. Silver metal particles deposited with an average size 4-10 nm. A stabilizer concentration of 10- 40 g/l was used. The average size of the prepared silver decreased with increase of the anode current density. Size uniformity of the silver nano-particles was improved distinctly at higher current density no more than 20mA... Grain size increased with EK time whereby aggregation of particles was observed after 6 h of reaction.. The chemical method involves adsorption of silver nitrate on the carbon substrate. Adsorbed silver ions were directly reduced to metal particles using hydrazine hydrate. Another alternative method is by treatment with ammonia followed by heating the carbon loaded-silver hydroxide at 980°C. The product was characterized with the help of XRD, XRF, ICP, SEM and TEM techniques.
Abstract: Springback is a significant problem in the sheet metal
forming process. When the tools are released after the stage of
forming, the product springs out, because of the action of the internal
stresses. In many cases the deviation of form is too large and the
compensation of the springback is necessary. The precise prediction
of the springback of product is increasingly significant for the design
of the tools and for compensation because of the higher ratio of the
yield stress to the elastic modulus.
The main object in this paper was to study the effect of the
anisotropy on the springback for three directions of rolling: 0°, 45°
and 90°. At the same time, we highlighted the influence of three
different metallic materials: Aluminum, Steel and Galvanized steel.
The original of our purpose consist on tests which are ensured by
adapting a U-type stretching-bending device on a tensile testing
machine, where we studied and quantified the variation of the
springback according to the direction of rolling. We also showed the
role of lubrication in the reduction of the springback.
Moreover, in this work, we have studied important characteristics
in deep drawing process which is a springback. We have presented
defaults that are showed in this process and many parameters
influenced a springback.
Finally, our results works lead us to understand the influence of
grains orientation with different metallic materials on the springback
and drawing some conclusions how to concept deep drawing tools. In
addition, the conducted work represents a fundamental contribution
in the discussion the industry application.
Abstract: An attempt has been made to investigate the
machinability of zirconia toughened alumina (ZTA) inserts while
turning AISI 4340 steel. The insert was prepared by powder
metallurgy process route and the machining experiments were
performed based on Response Surface Methodology (RSM) design
called Central Composite Design (CCD). The mathematical model of
flank wear, cutting force and surface roughness have been developed
using second order regression analysis. The adequacy of model has
been carried out based on Analysis of variance (ANOVA) techniques.
It can be concluded that cutting speed and feed rate are the two most
influential factor for flank wear and cutting force prediction. For
surface roughness determination, the cutting speed & depth of cut
both have significant contribution. Key parameters effect on each
response has also been presented in graphical contours for choosing
the operating parameter preciously. 83% desirability level has been
achieved using this optimized condition.
Abstract: The hybridisation of genetic algorithm with heuristics has been shown to be one of an effective way to improve its performance. In this work, genetic algorithm hybridised with four heuristics including a new heuristic called neighbourhood improvement were investigated through the classical travelling salesman problem. The experimental results showed that the proposed heuristic outperformed other heuristics both in terms of quality of the results obtained and the computational time.
Abstract: Photo-BJMOSFET (Bipolar Junction Metal-Oxide-
Semiconductor Field Effect Transistor) fabricated on SOI film was proposed. ITO film is adopted in the device as gate electrode to reduce
light absorption. Depletion region but not inversion region is formed
in film by applying gate voltage (but low reverse voltage) to achieve
high photo-to-dark-current ratio. Comparisons of photoelectriccharacteristics
executed among VGK=0V, 0.3V, 0.6V, 0.9V and 1.0V
(reverse voltage VAK is equal to 1.0V for total area of 10×10μm2). The
results indicate that the greatest improvement in photo-to-dark-current
ratio is achieved up to 2.38 at VGK=0.6V. In addition,
photo-BJMOSFET is compatible with CMOS integration due to big
input resistance
Abstract: It is well known that metallic particles reduce the
reliability of Gas-Insulated Substation (GIS) equipments by initiating
partial discharge (PDs) that can lead to breakdown and complete
failure of GIS. This paper investigates the characteristics of PDs
caused by metallic particle adhering to the solid spacer. The PD
detection and measurement were carried out by using IEC 60270
method with particles of different sizes and at different positions on
the spacer surface. The results show that a particle of certain size at
certain position possesses a unique PD characteristic as compared to
those caused by particles of different sizes and/or at different
positions. Therefore PD characteristics may be useful for the particle
size and position identification.
Abstract: True stress-strain curve of railhead steel is required to
investigate the behaviour of railhead under wheel loading through elasto-plastic Finite Element (FE) analysis. To reduce the rate of wear, the railhead material is hardened through annealing and
quenching. The Australian standard rail sections are not fully hardened and hence suffer from non-uniform distribution of the
material property; usage of average properties in the FE modelling can potentially induce error in the predicted plastic strains. Coupons
obtained at varying depths of the railhead were, therefore, tested under axial tension and the strains were measured using strain gauges as well as an image analysis technique, known as the Particle Image Velocimetry (PIV). The head hardened steel exhibit existence of three distinct zones of yield strength; the yield strength as the ratio of the average yield strength provided in the standard (σyr=780MPa) and
the corresponding depth as the ratio of the head hardened zone along
the axis of symmetry are as follows: (1.17 σyr, 20%), (1.06 σyr, 20%-80%) and (0.71 σyr, > 80%). The stress-strain curves exhibit limited plastic zone with fracture occurring at strain less than 0.1.
Abstract: Today-s children, who are born into a more colorful,
more creative, more abstract and more accessible communication
environment than their ancestors as a result of dizzying advances in
technology, have an interesting capacity to perceive and make sense
of the world. Millennium children, who live in an environment where
all kinds of efforts by marketing communication are more intensive
than ever are, from their early childhood on, subject to all kinds of
persuasive messages. As regards advertising communication, it
outperforms all the other marketing communication efforts in
creating little consumer individuals and, as a result of processing of
codes and signs, plays a significant part in building a world of seeing,
thinking and understanding for children. Children who are raised with
metaphorical expressions such as tales and riddles also meet that fast
and effective meaning communication in advertisements.
Children-s perception of metaphors, which help grasp the “product
and its promise" both verbally and visually and facilitate association
between them is the subject of this study. Stimulating and activating
imagination, metaphors have unique advantages in promoting the
product and its promise especially in regard to print advertisements,
which have certain limitations. This study deals comparatively with
both literal and metaphoric versions of print advertisements
belonging to various product groups and attempts to discover to what
extent advertisements are liked, recalled, perceived and are
persuasive. The sample group of the study, which was conducted in
two elementary schools situated in areas that had different socioeconomic
features, consisted of children aged 12.
Abstract: Cabbage seedlings grown in vitro were exposed to
excess levels of heavy metals, including Cd, Mo, and Zn. High metal
levels affected plant growth at cotyledonary stage. Seedlings under
Cd, Mo, and Zn treatments could not produce root hairs and true
leaves. Under stress conditions, seedlings accumulated a higher
amount of anthocyanins in their cotyledons than those in the control.
The pigments isolated from Cd and Zn stressed seedling cotyledons
appeared as pink, while under Mo stress, was dark pink or purple.
Moreover, excess Mo stress increased antioxidant enzyme activities
of APX, CAT, SOD. These results suggest that, under excess Mo
stress, the induced antioxidant enzyme activity of cabbage seedlings
may function as a protective mechanism to shield the plants from
toxicity and exacerbated growth.
Abstract: The ability of pomelo peel, a natural biosorbent, to remove Cd(II) ions from aqueous solution by biosorption was investigated. The experiments were carried out by batch method at 25 °C. The influence of solution pH, initial cadmium ion concentrations and contact times were evaluated. Cadmium ion removal increased significantly as the pH of the solution increased from pH 1 to pH 5. At pH 5, the cadmium ion removal reached a maximum value. The equilibrium process was described well by the Langmuir isotherm model, with a maximum biosorption capacity of 21.83 mg/g. The biosorption was relatively quick, (approx. 20 min). Biosorption kinetics followed a pseudo-second-order model. The result showed that pomelo peel was effective as a biosorbent for removing cadmium ions from aqueous solution. It is a low cost material that shows potential to be applied in wastewater technology for remediation of heavy metal contamination.
Abstract: P2P Networks are highly dynamic structures since
their nodes – peer users keep joining and leaving continuously. In the
paper, we study the effects of network change rates on query routing
efficiency. First we describe some background and an abstract system
model. The chosen routing technique makes use of cached metadata
from previous answer messages and also employs a mechanism for
broken path detection and metadata maintenance. Several metrics are
used to show that the protocol behaves quite well even with high rate
of node departures, but above a certain threshold it literally breaks
down and exhibits considerable efficiency degradation.
Abstract: This paper presents a novel three-phase utility
frequency to high frequency soft switching power conversion circuit
with dual mode pulse width modulation and pulse density modulation
for high power induction heating applications as melting of steel and
non ferrous metals, annealing of metals, surface hardening of steel
and cast iron work pieces and hot water producers, steamers and
super heated steamers. This high frequency power conversion circuit
can operate from three-phase systems to produce high current for
high power induction heating applications under the principles of
ZVS and it can regulate its ac output power from the rated value to a
low power level. A dual mode modulation control scheme based on
high frequency PWM in synchronization with the utility frequency
positive and negative half cycles for the proposed high frequency
conversion circuit and utility frequency pulse density modulation is
produced to extend its soft switching operating range for wide ac
output power regulation. A dual packs heat exchanger assembly is
designed to be used in consumer and industrial fluid pipeline systems
and it is proved to be suitable for the hot water, steam and super
heated steam producers. Experiment and simulation results are given
in this paper to verify the operation principles of the proposed ac
conversion circuit and to evaluate its power regulation and
conversion efficiency. Also, the paper presents a mutual coupling
model of the induction heating load instead of equivalent transformer
circuit model.
Abstract: Constant amplitude fatigue crack growth (FCG) tests
were performed on dissimilar metal welded plates of Type 316L
Stainless Steel (SS) and IS 2062 Grade A Carbon steel (CS). The
plates were welded by TIG welding using SS E309 as electrode. FCG
tests were carried on the Side Edge Notch Tension (SENT)
specimens of 5 mm thickness, with crack initiator (notch) at base
metal region (BM), weld metal region (WM) and heat affected zones
(HAZ). The tests were performed at a test frequency of 10 Hz and at
load ratios (R) of 0.1 & 0.6. FCG rate was found to increase with
stress ratio for weld metals and base metals, where as in case of
HAZ, FCG rates were almost equal at high ΔK. FCG rate of HAZ of
stainless steel was found to be lowest at low and high ΔK. At
intermediate ΔK, WM showed the lowest FCG rate. CS showed
higher crack growth rate at all ΔK. However, the scatter band of data
was found to be narrow. Fracture toughness (Kc) was found to vary
in different locations of weldments. Kc was found lowest for the
weldment and highest for HAZ of stainless steel. A novel method of
characterizing the FCG behavior using an Infrared thermography
(IRT) camera was attempted. By monitoring the temperature rise at
the fast moving crack tip region, the amount of plastic deformation
was estimated.
Abstract: The growing health hazardous impact of arsenic (As)
contamination in environment is the impetus of the present
investigation. Application of lactic acid bacteria (LAB) for the
removal of toxic and heavy metals from water has been reported.
This study was performed in order to isolate and characterize the Asresistant
LAB from mud and sludge samples for using as efficient As
uptaking probiotic. Isolation of As-resistant LAB colonies was
performed by spread plate technique using bromocresol purple
impregnated-MRS (BP-MRS) agar media provided with As @ 50
μg/ml. Isolated LAB were employed for probiotic characterization
process, acid and bile tolerance, lactic acid production, antibacterial
activity and antibiotic tolerance assays. After As-resistant and
removal characterizations, the LAB were identified using 16S rDNA
sequencing. A total of 103 isolates were identified as As-resistant
strains of LAB. The survival of 6 strains (As99-1, As100-2, As101-3,
As102-4, As105-7, and As112-9) was found after passing through the
sequential probiotic characterizations. Resistant pattern pronounced
hollow zones at As concentration >2000 μg/ml in As99-1, As100-2,
and As101-3 LAB strains, whereas it was found at ~1000 μg/ml in
rest 3 strains. Among 6 strains, the As uptake efficiency of As102-4
(0.006 μg/h/mg wet weight of cell) was higher (17 – 209%)
compared to remaining LAB. 16S rDNA sequencing data of 3 (As99-
1, As100-2, and As101-3) and 3 (As102-4, As105-7, and As112-9)
LAB strains clearly showed 97 to 99% (340 bp) homology to
Pediococcus dextrinicus and Pediococcus acidilactici, respectively.
Though, there was no correlation between the metal resistant and
removal efficiency of LAB examined but identified elevated As
removing LAB would probably be a potential As uptaking probiotic
agent. Since present experiment concerned with only As removal
from pure water, As removal and removal mechanism in natural
condition of intestinal milieu should be assessed in future studies.