Abstract: The Helmholtz equation often arises in the study of physical problems involving partial differential equation. Many researchers have proposed numerous methods to find the analytic or approximate solutions for the proposed problems. In this work, the exact analytical solutions of the Helmholtz equation in spherical polar coordinates are presented using the Nikiforov-Uvarov (NU) method. It is found that the solution of the angular eigenfunction can be expressed by the associated-Legendre polynomial and radial eigenfunctions are obtained in terms of the Laguerre polynomials. The special case for k=0, which corresponds to the Laplace equation is also presented.
Abstract: One of the most important parameters to develop and
manage urban areas is appropriate selection of land surface to
develop green spaces in these areas. In this study, in order to identify
the most appropriate sites and areas cultivated for ornamental species
in Jiroft, Landsat Enhanced Thematic Mapper Plus (ETM+) images
due to extract the most important effective climatic and adaphic
parameters for growth ornamental species were used. After geometric
and atmospheric corrections applied, to enhance accuracy of multi
spectral (XS) bands, the fusion of Landsat XS bands by IRS-1D
panchromatic band (PAN) was performed. After field sampling to
evaluate the correlation between different factors in surface soil
sampling location and different bands digital number (DN) of ETM+
sensor on the same points, correlation tables formed using the best
computational model and the map of physical and chemical
parameters of soil was produced. Then the accuracy of them was
investigated by using kappa coefficient. Finally, according to
produced maps, the best areas for cultivation of recommended
species were introduced.
Abstract: This study investigated morphology of the Spanner Barb (Puntius lateristriga Valenciennes, 1842) and water quality at Thepchana waterfall. This study was conducted at Thepchana Waterfall, Khao Nan National Park from March to May 2007. There were 40 Spanner Barb collected with 20 males and 20 females. Males had an average of 5.57 cm in standard length, 6.62 cm in total length and 5.18 g in total body weight. Females had an average of 7.25 cm in standard length, 8.24 cm in total length and 10.96 g in total body weight. The length (L) – weight (W) relationships for combining sexes, males and females were LogW = -2.137 + 3.355logL, log W = -0.068 + 3.297logL, and log W = -2.068 + 3.297logL, respectively. The Spanner Barb were smaller size fish with a compressed form; terminal mouth; villiform teeth; ctenoid scale; concave tail; general body color yellowish olive, with slight reddish tint to fins; vertical band beginning below dorsal and horizontal stripe from base of tail almost to vertical band. They also had a vertical band midway between the eye and first vertical band. There was a black spot above anal fin. The bladder looked like J-shape. Inside of the bladder was found small insects and insect lava. The body length and the bowels length was 1:1 ratio. The water temperature ranged from 25.00 – 27.00 °C which was appropriate for their habitat characteristics. Acid - alkalinity ranged from 6.65 – 6.90 mg/l. Dissolved oxygen ranged from 4.55 – 4.70 mg/l. Water hardness ranged from 31.00 – 48.00 mg/l. The amount of ammonia was about 0.25 mg/l.
Abstract: Until recently, researchers have developed various
tools and methodologies for effective clinical decision-making.
Among those decisions, chest pain diseases have been one of
important diagnostic issues especially in an emergency department. To
improve the ability of physicians in diagnosis, many researchers have
developed diagnosis intelligence by using machine learning and data
mining. However, most of the conventional methodologies have been
generally based on a single classifier for disease classification and
prediction, which shows moderate performance. This study utilizes an
ensemble strategy to combine multiple different classifiers to help
physicians diagnose chest pain diseases more accurately than ever.
Specifically the ensemble strategy is applied by using the integration
of decision trees, neural networks, and support vector machines. The
ensemble models are applied to real-world emergency data. This study
shows that the performance of the ensemble models is superior to each
of single classifiers.
Abstract: In this paper as showed a non-invasive 3D eye tracker
for optometry clinical applications. Measurements of biomechanical
variables in clinical practice have many font of errors associated with
traditional procedments such cover test (CT), near point of
accommodation (NPC), eye ductions (ED), eye vergences (EG) and,
eye versions (ES). Ocular motility should always be tested but all
evaluations have a subjective interpretations by practitioners, the
results is based in clinical experiences, repeatability and accuracy
don-t exist. Optometric-lab is a tool with 3 (tree) analogical video
cameras triggered and synchronized in one acquisition board AD.
The variables globe rotation angle and velocity can be quantified.
Data record frequency was performed with 27Hz, camera calibration
was performed in a know volume and image radial distortion
adjustments.
Abstract: This paper investigates the problem of tracking spa¬tiotemporal changes of a satellite image through the use of Knowledge Discovery in Database (KDD). The purpose of this study is to help a given user effectively discover interesting knowledge and then build prediction and decision models. Unfortunately, the KDD process for spatiotemporal data is always marked by several types of imperfections. In our paper, we take these imperfections into consideration in order to provide more accurate decisions. To achieve this objective, different KDD methods are used to discover knowledge in satellite image databases. Each method presents a different point of view of spatiotemporal evolution of a query model (which represents an extracted object from a satellite image). In order to combine these methods, we use the evidence fusion theory which considerably improves the spatiotemporal knowledge discovery process and increases our belief in the spatiotemporal model change. Experimental results of satellite images representing the region of Auckland in New Zealand depict the improvement in the overall change detection as compared to using classical methods.
Abstract: We study the semiconvergence of Gauss-Seidel iterative
methods for the least squares solution of minimal norm of rank
deficient linear systems of equations. Necessary and sufficient conditions
for the semiconvergence of the Gauss-Seidel iterative method
are given. We also show that if the linear system of equations is
consistent, then the proposed methods with a zero vector as an initial
guess converge in one iteration. Some numerical results are given to
illustrate the theoretical results.
Abstract: Alkali Activated Slag Concrete (AASC) mixes are manufactured by activating ground granulated blast furnace slag (GGBFS) using sodium hydroxide and sodium silicate solutions. The aim of the present experimental research was to investigate the effect of increasing the dosages of sodium oxide (Na2O, in the range of 4 to 8%) and the activator modulus (Ms) (i.e. the SiO2/Na2O ratio, in the range of 0.5 to 1.5) of the alkaline solutions, on the workability and strength characteristics of self-cured (air-cured) alkali activated Indian slag concrete mixes. Further the split tensile and flexure strengths for optimal mixes were studied for each dosage of Na2O.It is observed that increase in Na2O concentration increases the compressive, split-tensile and flexural strengths, both at the early and later-ages, while increase in Ms, decreases the workability of the mixes. An optimal Ms of 1.25 is found at various Na2O dosages. No significant differences in the strength performances were observed between AASCs manufactured with alkali solutions prepared using either of potable and de-ionized water.
Abstract: Industrial robots play a vital role in automation
however only little effort are taken for the application of robots in
machining work such as Grinding, Cutting, Milling, Drilling,
Polishing etc. Robot parallel manipulators have high stiffness,
rigidity and accuracy, which cannot be provided by conventional
serial robot manipulators. The aim of this paper is to perform the
modeling and the workspace analysis of a 3 DOF Parallel
Manipulator (3 DOF PM). The 3 DOF PM was modeled and
simulated using 'ADAMS'. The concept involved is based on the
transformation of motion from a screw joint to a spherical joint
through a connecting link. This paper work has been planned to
model the Parallel Manipulator (PM) using screw joints for very
accurate positioning. A workspace analysis has been done for the
determination of work volume of the 3 DOF PM. The position of the
spherical joints connected to the moving platform and the
circumferential points of the moving platform were considered for
finding the workspace. After the simulation, the position of the joints
of the moving platform was noted with respect to simulation time and
these points were given as input to the 'MATLAB' for getting the
work envelope. Then 'AUTOCAD' is used for determining the work
volume. The obtained values were compared with analytical
approach by using Pappus-Guldinus Theorem. The analysis had been
dealt by considering the parameters, link length and radius of the
moving platform. From the results it is found that the radius of
moving platform is directly proportional to the work volume for a
constant link length and the link length is also directly proportional
to the work volume, at a constant radius of the moving platform.
Abstract: For decades, the defense business has been plagued by
not having a reliable, deterministic method to know when the Kalman
filter solution for passive ranging application is reliable for use by the
fighter pilot. This has made it hard to accurately assess when the
ranging solution can be used for situation awareness and weapons
use. To date, we have used ad hoc rules-of-thumb to assess when we
think the estimate of the Kalman filter standard deviation on range is
reliable. A reliable algorithm has been developed at BAE Systems
Electronics & Integrated Solutions that monitors the Kalman gain
matrix elements – and a patent is pending. The “settling" of the gain
matrix elements relates directly to when we can assess the time when
the passive ranging solution is within the 10 percent-of-truth value.
The focus of the paper is on surface-based passive ranging – but the
method is applicable to airborne targets as well.
Abstract: DC-DC converters are widely used in regulated switched mode power supplies and in DC motor drive applications. There are several sources of unwanted nonlinearity in practical power converters. In addition, their operation is characterized by switching that gives birth to a variety of nonlinear dynamics. DC-DC buck and boost converters controlled by pulse-width modulation (PWM) have been simulated. The voltage waveforms and attractors obtained from the circuit simulation have been studied. With the onset of instability, the phenomenon of subharmonic oscillations, quasi-periodicity, bifurcations, and chaos have been observed. This paper is mainly motivated by potential contributions of chaos theory in the design, analysis and control of power converters, in particular and power electronics circuits, in general.
Abstract: People usually have a telephone voice, which means
they adjust their speech to fit particular situations and to blend in with
other interlocutors. The question is: Do we speak differently to
different people? This possibility has been suggested by social
psychologists within Accommodation Theory [1]. Converging toward
the speech of another person can be regarded as a polite speech
strategy while choosing a language not used by the other interlocutor
can be considered as the clearest example of speech divergence [2].
The present study sets out to investigate such processes in the course
of everyday telephone conversations. Using Joos-s [3] model of
formality in spoken English, the researchers try to explore
convergence to or divergence from the addressee. The results
propound the actuality that lexical choice, and subsequently, patterns
of style vary intriguingly in concordance with the person being
addressed.
Abstract: In rotating machinery one of the critical components
that is prone to premature failure is the rolling bearing.
Consequently, early warning of an imminent bearing failure is much
critical to the safety and reliability of any high speed rotating
machines. This study is concerned with the application of Recurrence
Quantification Analysis (RQA) in fault detection of rolling element
bearings in rotating machinery. Based on the results from this study it
is reported that the RQA variable, percent determinism, is sensitive
to the type of fault investigated and therefore can provide useful
information on bearing damage in rolling element bearings.
Abstract: Internal combustion engines rejects 30-40% of the
energy supplied by fuel to the environment through exhaust gas. thus, there is a possibility for further significant improvement of efficiency with the utilization of exhaust gas energy and its conversion to mechanical energy or electrical energy. The Thermo-Electric
Generator (TEG) will be located in the exhaust system and will make use of an energy flow between the warmer exhaust gas and the external environment. Predict to th optimum position of temperature
distribution and the performance of TEG through numerical analysis.
The experimental results obtained show that the power output significantly increases with the temperature difference between cold
and hot sides of a thermoelectric generator.
Abstract: In industrial scale of Gas to Liquid (GTL) process in
Fischer-Tropsch (FT) synthesis, a part of reactor outlet gases such as
CO2 and CH4 as side reaction products, is usually recycled. In this
study, the influence of CO2 and CH4 on the performance and
selectivity of Co-Ru/Al2O3 catalyst is investigated by injection of
these gases (0-20 vol. % of feed) to the feed stream. The effect of
temperature and feed flow rate, are also inspected. The results show
that low amounts of CO2 in the feed stream, doesn`t change the
catalyst activity significantly but increasing the amount of CO2 (more
than 10 vol. %) cause the CO conversion to decrease and the
selectivity of heavy components to increase. Methane acts as an inert
gas and doesn`t affect the catalyst performance. Increasing feed flow
rate has negative effect on both CO conversion and heavy component
selectivity. By raising the temperature, CO conversion will increase
but there are more volatile components in the product. The effect of
CO2 on the catalyst deactivation is also investigated carefully and a
mechanism is suggested to explain the negative influence of CO2 on
catalyst deactivation.
Abstract: This work aims to explore the factors that have an incidence in reading comprehension process, with different type of texts. In a recent study with 2nd, 3rd and 4th grade children, it was observed that reading comprehension of narrative texts was better than comprehension of expository texts. Nevertheless it seems that not only the type of text but also other textual factors would account for comprehension depending on the cognitive processing demands posed by the text. In order to explore this assumption, three narrative and three expository texts were elaborated with different degree of complexity. A group of 40 fourth grade Spanish-speaking children took part in the study. Children were asked to read the texts and answer orally three literal and three inferential questions for each text. The quantitative and qualitative analysis of children responses showed that children had difficulties in both, narrative and expository texts. The problem was to answer those questions that involved establishing complex relationships among information units that were present in the text or that should be activated from children’s previous knowledge to make an inference. Considering the data analysis, it could be concluded that there is some interaction between the type of text and the cognitive processing load of a specific text.
Abstract: Using a set of confidence intervals, we develop a
common approach, to construct a fuzzy set as an estimator for
unknown parameters in statistical models. We investigate a method
to derive the explicit and unique membership function of such fuzzy
estimators. The proposed method has been used to derive the fuzzy
estimators of the parameters of a Normal distribution and some
functions of parameters of two Normal distributions, as well as the
parameters of the Exponential and Poisson distributions.
Abstract: In sport, human resources management gives special
attention to method of applying volunteers, their maintenance, and
participation of volunteers with each other and management
approaches for better operation of events celebrants. The recognition
of volunteers- characteristics and motives is important to notice,
because it makes the basis of their participation and commitment at
sport environment. The motivation and commitment of 281
volunteers were assessed using the organizational commitment scale,
motivation scale and personal characteristics questionnaire.The
descriptive results showed that; 64% of volunteers were women with
age average 21/24 years old. They were physical education student,
single (71/9%), without occupation (53%) and with average of 5
years sport experience. Their most important motivation was career
factor and the most important commitment factor was normative
factor. The results of examining the hypothesized showed that; age,
sport experience and education are effective in the amount of
volunteers- commitment. And the motive factors such as career,
material, purposive and protective factors also have the power to
predict the amount of sports volunteers- commitment value.
Therefore it is recommended to provide possible opportunities for
volunteers and carrying out appropriate instructional courses by
events executive managers.
Abstract: Aquatic and semi aquatic birds as a group are suited to
feed and breed in environments in which water forms a fundamental
part. These birds are biological indicator in aquatic environment,
because these birds belong to the top level of food chain in aquatic
ecosystems. There are 61 species in 14 families of aquatic and semi
aquatic birds in Iran. The birds of the Sattarkhan Lake belong to 16
species in 8 families which include 26.2 percent of total Aquatic and
semi aquatic bird species and 57% of Aquatic and semi aquatic bird's
family of Iran. Study was carried out monthly at Sattarkhan Lake
show the existence of Phalacrocorax carbo, Ardea cinerea, Egretta
alba, Egretta garzetta, Bubulcus ibis, Botaurus stellaris, Sterna
hirundo, Chlidonias leucopterus, Larus minutus, Larus argentatus,
Larus ridibunbus, Alcedo atthis, Ciconia ciconia, Plegadis
falcinellus, Circus aeruginosus, Corvus frugilegus
Abstract: Nowadays, consumption of whole flours and flours
with high extraction rate is recommended, because of their high
amount of fibers, vitamins and minerals. Despite nutritional benefits
of whole flour, concentration of some undesirable components such
as phytic acid is higher than white flour. In this study, effect of
several lactic acid bacteria sourdough on Toast bread is investigated.
Sourdough from lactic acid bacteria (Lb. plantarum, Lb. reuteri) with
different dough yield (250 and 300) is made and incubated at 30°C
for 20 hour, then added to dough in the ratio of 10, 20 and 30%
replacement. Breads that supplemented with Lb. plantarum
sourdough had lower phytic acid. Higher replacement of sourdough
and higher DY cause higher decrease in phytic acid content.
Sourdough from Lb. plantarum, DY = 300 and 30% replacement
cause the highest decrease in phytic acid content (49.63 mg/100g).
As indicated by panelists, Lb. reuteri sourdough can present the
greatest effect on overall quality score of the breads. DY reduction
cause a decrease in bread quality score. Sensory score of Toast bread
is 81.71 in the samples that treated with Lb. reuteri sourdough with
DY = 250 and 20% replacement.