Abstract: Most neural network (NN) models of human category learning use a gradient-based learning method, which assumes that locally-optimal changes are made to model parameters on each learning trial. This method tends to under predict variability in individual-level cognitive processes. In addition many recent models of human category learning have been criticized for not being able to replicate rapid changes in categorization accuracy and attention processes observed in empirical studies. In this paper we introduce stochastic learning algorithms for NN models of human category learning and show that use of the algorithms can result in (a) rapid changes in accuracy and attention allocation, and (b) different learning trajectories and more realistic variability at the individual-level.
Abstract: We deal with the numerical solution of time-dependent convection-diffusion-reaction equations. We combine the local projection stabilization method for the space discretization with two different time discretization schemes: the continuous Galerkin-Petrov (cGP) method and the discontinuous Galerkin (dG) method of polynomial of degree k. We establish the optimal error estimates and present numerical results which shows that the cGP(k) and dG(k)- methods are accurate of order k +1, respectively, in the whole time interval. Moreover, the cGP(k)-method is superconvergent of order 2k and dG(k)-method is of order 2k +1 at the discrete time points. Furthermore, the dependence of the results on the choice of the stabilization parameter are discussed and compared.
Abstract: Chitosan is a biopolymer composed of glucosamine
and N-acetyl glucosamine. Solubility and viscosity pose problems in
some applications. These problems can be overcome with unique
modifications. In this study, firstly, chitosan was modified by caffeic
acid and thioglycolic acid, separately. Then, growing effects of these
modified polymers was observed in U937 cell line. Caffeic acid is a
phenolic compound and its modifications act carcinogenic inhibitors
in drugs. Thiolated chitosans are commonly being used for drugdelivery
systems in various routes, because of enhancing
mucoadhesiveness property. U937 cell line was used model cell for
leukaemia. Modifications were achieved by 1 – 15 % binding range.
Increasing binding ratios showed higher radical-scavenging activity
and reducing cell growth, in compared to native chitosan. Caffeic
acid modifications showed higher radical-scavenging activity than
thiolated chitosans at the same concentrations. Caffeic acid and
thioglycolic acid modifications inhibited growth of U937, effectively.
Abstract: An experiment of vented gas explosions involving two
different cylinder vessel volumes (0.2 and 0.0065 m3) was reported,
with equivalence ratio (Φ) ranged from 0.3 to 1.6. Both vessels were
closed at the rear end and fitted at the other side with a circular
orifice plate that gives a constant vent coefficient (K =Av/V2/3) of
16.4. It was shown that end ignition gives higher overpressures than
central ignition, even though most of the published work on venting
uses central ignition. For propane and ethylene, it is found that rich
mixtures gave the highest overpressures and these mixtures are not
considered in current vent design guidance; which the guideline is
based on mixtures giving the maximum flame temperature. A strong
influence of the vessel volume at constant K was found for methane,
propane, ethylene and hydrogen-air explosions. It can be concluded
that self- acceleration of the flame, which is dependent on the
distance of a flame from the ignition and the ‘suction’ at the vent
opening are significant factors affecting the vent flow during
explosion development in vented gas explosion. This additional
volume influence on vented explosions is not taken into account in
the current vent design guidance.
Abstract: In this paper methodology to exploit creeping wave
for body area network BAN communication reliability are described.
Creeping wave propagation effects are visualized & analyzed.
During this work Dipole, IA antennas various antennas were
redesigned using existing designs and their propagation
characteristics were verified for optimum performance when used on
BANs. These antennas were then applied on body shapes-including
rectangular, spherical and cylindrical so that all the effects of actual
human body can be taken nearly into account. Parametric simulation
scheme was devised so that on Body channel characterization can be
visualized at front, curved and back region. In the next phase
multiple inputs multiple output MIMO scheme was introduced where
virtual antennas were used in order to diminish the effects of
antennas on the propagation of waves. Results were, extracted and
analyzed at different heights. Finally based on comparative
measurement and analysis it was concluded that on body propagation
can be exploited to gain spatial diversity.
Abstract: This paper reports an experimental study on a sleeping
thermal manikin in a room equipped with a mixing ventilation
system. In the experimental work, heat loss from the sleeping thermal
manikin was measured under different conditions. The supply air
temperature was in a range of 17°C to 27°C. Apart from the heat loss
of the sleeping thermal manikin, the velocity distributions and
temperature distributions were also measured in the experiments for
subsequent analysis.
Abstract: The aim of the present investigation was to compare
sex differences in thyroid gland structure of rabbits. Five adult male
and five adult female (3.1-3.5 kg body weight) New Zealand white
rabbits were used in the experiment. Results showed that at light
microscopic level, there was no sex difference in microscopic
appearance of the thyroid glands. At electron microscopic level,
however, the mitochondria and the microvilli of the follicular cells
are more numerous and the Golgi complex is also more extensive in
male rabbits in comparison to females. Results obtained from
micrometric measurements showed that the volume density of the
follicles is higher in males than in females, but the differences are not
statistically significant .The volume density of epithelium and the
height of follicular cells are significantly greater in males than in
females and reverse is true about the volume density of interstitium
(p
Abstract: Circular tubes have been widely used as structural
members in engineering application. Therefore, its collapse behavior
has been studied for many decades, focusing on its energy absorption
characteristics. In order to predict the collapse behavior of members,
one could rely on the use of finite element codes or experiments.
These tools are helpful and high accuracy but costly and require
extensive running time. Therefore, an approximating model of tubes
collapse mechanism is an alternative for early step of design. This
paper is also aimed to develop a closed-form solution of thin-walled
circular tube subjected to bending. It has extended the Elchalakani et
al.-s model (Int. J. Mech. Sci.2002; 44:1117-1143) to include the
rate of energy dissipation of rolling hinge in the circumferential
direction. The 3-D geometrical collapse mechanism was analyzed by
adding the oblique hinge lines along the longitudinal tube within the
length of plastically deforming zone. The model was based on the
principal of energy rate conservation. Therefore, the rates of internal
energy dissipation were calculated for each hinge lines which are
defined in term of velocity field. Inextensional deformation and
perfect plastic material behavior was assumed in the derivation of
deformation energy rate. The analytical result was compared with
experimental result. The experiment was conducted with a number of
tubes having various D/t ratios. Good agreement between analytical
and experiment was achieved.
Abstract: The present work describes an experimental
investigation concerning the determination of viscosity behavior with
shear rate and temperature of edible oils: canola; sunflower; corn;
soybean and the no edible oil: Jatropha curcas. Besides these, it was
tested a blend of canola, corn and sunflower oils as well as sunflower
and soybean biodiesel. Based on experiments, it was obtained shear
stress and viscosity at different shear rates of each sample at 40ºC, as
well as viscosity of each sample at various temperatures in the range
of 24 to 85ºC. Furthermore, it was compared the curves obtained for
the viscosity versus temperature with the curves obtained by
modeling the viscosity dependency on temperature using the Vogel
equation. Also a test in a stationary engine was performed in order to
study the energy generation using blends of soybean oil and soybean
biodiesel with diesel.
Abstract: This study investigated climatic factors associated
with influenza cases in Southern Thailand. The main aim for use
regression analysis to investigate possible causual relationship of
climatic factors and variability between the border of the Andaman
Sea and the Gulf of Thailand. Southern Thailand had the highest
Influenza incidences among four regions (i.e. north, northeast, central
and southern Thailand). In this study, there were 14 climatic factors:
mean relative humidity, maximum relative humidity, minimum
relative humidity, rainfall, rainy days, daily maximum rainfall,
pressure, maximum wind speed, mean wind speed, sunshine duration,
mean temperature, maximum temperature, minimum temperature,
and temperature difference (i.e. maximum – minimum temperature).
Multiple stepwise regression technique was used to fit the statistical
model. The results indicated that the mean wind speed and the
minimum relative humidity were positively associated with the
number of influenza cases on the Andaman Sea side. The maximum
wind speed was positively associated with the number of influenza
cases on the Gulf of Thailand side.
Abstract: The product development process (PDP) in the
Technology group plays a very important role in the launch of any
product. While a manufacturing process encourages the use of certain
measures to reduce health, safety and environmental (HSE) risks on
the shop floor, the PDP concentrates on the use of Geometric
Dimensioning and Tolerancing (GD&T) to develop a flawless design.
Furthermore, PDP distributes and coordinates activities between
different departments such as marketing, purchasing, and
manufacturing. However, it is seldom realized that PDP makes a
significant contribution to developing a product that reduces HSE
risks by encouraging the Technology group to use effective GD&T.
The GD&T is a precise communication tool that uses a set of
symbols, rules, and definitions to mathematically define parts to be
manufactured. It is a quality assurance method widely used in the oil
and gas sector. Traditionally it is used to ensure the
interchangeability of a part without affecting its form, fit, and
function. Parts that do not meet these requirements are rejected
during quality audits.
This paper discusses how the Technology group integrates this
quality assurance tool into the PDP and how the tool plays a major
role in helping the HSE department in its goal towards eliminating
HSE incidents. The PDP involves a thorough risk assessment and
establishes a method to address those risks during the design stage.
An illustration shows how GD&T helped reduce safety risks by
ergonomically improving assembling operations. A brief discussion
explains how tolerances provided on a part help prevent finger injury.
This tool has equipped Technology to produce fixtures, which are
used daily in operations as well as manufacturing. By applying
GD&T to create good fits, HSE risks are mitigated for operating
personnel. Both customers and service providers benefit from
reduced safety risks.
Abstract: Modern Society is strongly dependent on a reliable
power supply. The availability of cheap and reliable supply of
electrical energy is an indicator of societal welfare. Uninterrupted
reliable operation of a modern power system depends to a great
extent on reliable and satisfactory performance of insulators under
different environmental conditions. This paper reports result of
natural pollution tests that have been done at sites around city of
Aligarh (India). Flashover voltage per insulation distance (FOVUID)
of porcelain disc insulator for different pH values, ESDD has been
recorded for proper correlation between electrical and chemical
parameters. The pH of the contaminants has been suggested to be an
effective pollution severity indicator and may be used as a diagnostic
parameter for proper maintenance of porcelain insulators.
Abstract: Providing Services at Home has become over the last
few years a very dynamic and promising technological domain. It is
likely to enable wide dissemination of secure and automated living
environments. We propose a methodology for identifying threats to
Services at Home Delivery systems, as well as a threat analysis
of a multi-provider Home Gateway architecture. This methodology
is based on a dichotomous positive/preventive study of the target
system: it aims at identifying both what the system must do, and
what it must not do. This approach completes existing methods with
a synthetic view of potential security flaws, thus enabling suitable
measures to be taken into account. Security implications of the
evolution of a given system become easier to deal with. A prototype
is built based on the conclusions of this analysis.
Abstract: The hydrodynamic processes in bubbly liquid flowing
in tubes and nozzles are studied theoretically and numerically. The
principal regularities of non-stationary processes of boiling liquid
outflow are established under conditions of experiments when the
depressurization of a tube with high pressure inside occurs. The
steady-state solution of bubbly liquid flow in the nozzle of round
cross section with high pressure and temperature conditions inside
bubbles is studied accounting for phase transition and chemical
reactions.
Abstract: Nigella sativa L. is an aromatic plant belonging to the
family Ranunculaceae. It has been used traditionally, especially in the
middle East and India, for the treatment of asthma, cough, bronchitis,
headache, rheumatism, fever, influenza and eczema. Several
biological activities have been reported in Nigella sativa seeds,
including antioxidant. In this context we tried to estimate the
antioxidant activity of various extracts prepared from Nigella sativa
seeds, methanolic extract (ME), chloroformic extract (CE), hexanic
extract (HE : fixed oil), ethyl acetate extract (EAE) water extract
(WE). The Folin-Ciocalteu assay showed that CE and EAE contained
high level of phenolic compounds 81.31 and 72.43μg GAE/mg of
extract respectively. Similarly, the CE and EAE exhibited the highest
DPPH radical scavenging activity, with IC50 values of 106.56μg/ml
and 121.62μg/ml respectively. In addition, CE and HE showed the
most scavenging activity against superoxide radical generated in the
PMS-NADH-NBT system with respective IC50 values of 361.86
μg/ml and 371.80 μg/ml, which is comparable to the activity of the
standard antioxidant BHT (344.59 μg/ml). Ferrous ion chelating
capacity assay showed that WE, EAE and ME are the most active
with 40.57, 39.70 and 22.02 mg EDTA-E/g of extract. The inhibition
of linoleic acid/ß-carotene coupled oxidation was estimated by ßcarotene
bleaching assay, this showed a highest relative antioxidant
activity with CE and EAE (69.82% of inhibition). The antioxidant
activities of the methanolic extract and the fixed oil are confirmed by
an in vivo assay in mice, the daily oral administration of methanolic
extract (500 and 800 mg/kg/day) and fixed oil (2 and 4 ml/kg/day)
during 21 days, resulted in a significant enhancement of the blood
total antioxidant capacity (measured by KRL test) and the plasmatic
antioxidant capacity towards DPPH radical.
Abstract: In this paper we developed the Improved Runge-Kutta Nystrom (IRKN) method for solving second order ordinary differential equations. The methods are two step in nature and require lower number of function evaluations per step compared with the existing Runge-Kutta Nystrom (RKN) methods. Therefore, the methods are computationally more efficient at achieving the higher order of local accuracy. Algebraic order conditions of the method are obtained and the third and fourth order method are derived with two and three stages respectively. The numerical results are given to illustrate the efficiency of the proposed method compared to the existing RKN methods.
Abstract: Databases have become ubiquitous. Almost all IT applications are storing into and retrieving information from databases. Retrieving information from the database requires knowledge of technical languages such as Structured Query Language (SQL). However majority of the users who interact with the databases do not have a technical background and are intimidated by the idea of using languages such as SQL. This has led to the development of a few Natural Language Database Interfaces (NLDBIs). A NLDBI allows the user to query the database in a natural language. This paper highlights on architecture of new NLDBI system, its implementation and discusses on results obtained. In most of the typical NLDBI systems the natural language statement is converted into an internal representation based on the syntactic and semantic knowledge of the natural language. This representation is then converted into queries using a representation converter. A natural language query is translated to an equivalent SQL query after processing through various stages. The work has been experimented on primitive database queries with certain constraints.
Abstract: The interdependences among stock market indices
were studied for a long while by academics in the entire world. The
current financial crisis opened the door to a wide range of opinions
concerning the understanding and measurement of the connections
considered to provide the controversial phenomenon of market
integration. Using data on the log-returns of 17 stock market indices
that include most of the CEE markets, from 2005 until 2009, our
paper studies the problem of these dependences using a new
methodological tool that takes into account both the volatility
clustering effect and the stochastic properties of these linkages
through a Dynamic Conditional System of Simultaneous Equations.
We find that the crisis is well captured by our model as it provides
evidence for the high volatility – high dependence effect.
Abstract: The main purpose of this study is to explore current
and possible customer experiences in Bosphorus Zoo. Since there is
no previous research conducted on Turkish zoos- customer
experiences, we conduct an exploratory research taking the form of
depth interviews. Then, we group the experiences according to
strategic experiential modules (sense, feel, think, act and relate).
Abstract: The purpose of this article is to introduce an advanced
system for the support of processing of medical image information,
and the terminology related to this system, which can be an important
element to a faster transition to a fully digitalized hospital.
The core of the system is a set of DICOM compliant applications
running over a dedicated computer network. The whole integrated
system creates a collaborative platform supporting daily routines in
the radiology community, developing communication channels,
supporting the exchange of information and special consultations
among various medical institutions as well as supporting medical
training for practicing radiologists and medical students. It gives the
users outside of hospitals the tools to work in almost the same
conditions as in the radiology departments.