Abstract: High redundancy and strong uncertainty are two main characteristics for underwater robotic manipulators with unlimited workspace and mobility, but they also make the motion planning and control difficult and complex. In order to setup the groundwork for the research on control schemes, the mathematical representation is built by using the Denavit-Hartenberg (D-H) method [9]&[12]; in addition to the geometry of the manipulator which was studied for establishing the direct and inverse kinematics. Then, the dynamic model is developed and used by employing the Lagrange theorem. Furthermore, derivation and computer simulation is accomplished using the MATLAB environment. The result obtained is compared with mechanical system dynamics analysis software, ADAMS. In addition, the creation of intelligent artificial skin using Interlink Force Sensing ResistorTM technology is presented as groundwork for future work
Abstract: Complex assemblies of interacting proteins carry out
most of the interesting jobs in a cell, such as metabolism, DNA
synthesis, mitosis and cell division. These physiological properties
play out as a subtle molecular dance, choreographed by underlying
regulatory networks that control the activities of cyclin-dependent
kinases (CDK). The network can be modeled by a set of nonlinear
differential equations and its behavior predicted by numerical
simulation. In this paper, an innovative approach has been proposed
that uses genetic algorithms to mine a set of behavior data output by
a biological system in order to determine the kinetic parameters of
the system. In our approach, the machine learning method is
integrated with the framework of existent biological information in a
wiring diagram so that its findings are expressed in a form of system
dynamic behavior. By numerical simulations it has been illustrated
that the model is consistent with experiments and successfully shown
that such application of genetic algorithms will highly improve the
performance of mathematical model of the cell division cycle to
simulate such a complicated bio-system.
Abstract: Relevant agricultural information disseminator
(extension agent) ratio of 1:3500 farm families which become a
menace to agricultural production capacity in developing countries
necessitate this study. Out of 4 zones in the state, 24 extension agents
in each zone, 4 extension agents using cell phones and 120 farmers
using cell phone and 120 other farmers not using cell phone were
purposively selected to give 240 farmers that participated in the
research. Data were collected using interview guide and analysized
using frequency, percentage and t-test.. Frequency of contact with
agricultural information centers revealed that cell phone user farmers
had greater means score of X 41.43 contact as against the low mean
X19.32 contact recorded by farmers receiving agricultural
information from extension agents not using cell phone and their
production was statistically significant at P < 0.05. Usage of cell
phone increase extension agent contact and increase farmers-
production capacity.
Abstract: Today, Hydroforming technology provides an
attractive alternative to conventional matched die forming, especially
for cost-sensitive, lower volume production, and for parts with
irregular contours. In this study the critical fluid pressures which lead
to rupture in the workpiece has been investigated by theoretical and
finite element methods. The axisymmetric analysis was developed to
investigate the tearing phenomenon in cylindrical Hydroforming
Deep Drawing (HDD). By use of obtained equations the effect of
anisotropy, drawing ratio, sheet thickness and strain hardening
exponent on tearing diagram were investigated.
Abstract: The seismic response of steel shear wall system considering nonlinearity effects using finite element method is investigated in this paper. The non-linear finite element analysis has potential as usable and reliable means for analyzing of civil structures with the availability of computer technology. In this research the large displacements and materially nonlinear behavior of shear wall is presented with developing of finite element code. A numerical model based on the finite element method for the seismic analysis of shear wall is presented with developing of finite element code in this research. To develop the finite element code, the standard Galerkin weighted residual formulation is used. Two-dimensional plane stress model and total Lagrangian formulation was carried out to present the shear wall response and the Newton-Raphson method is applied for the solution of nonlinear transient equations. The presented model in this paper can be developed for analysis of civil engineering structures with different material behavior and complicated geometry.
Abstract: When binary decision diagrams are formed from
uniformly distributed Monte Carlo data for a large number of
variables, the complexity of the decision diagrams exhibits a
predictable relationship to the number of variables and minterms. In
the present work, a neural network model has been used to analyze the
pattern of shortest path length for larger number of Monte Carlo data
points. The neural model shows a strong descriptive power for the
ISCAS benchmark data with an RMS error of 0.102 for the shortest
path length complexity. Therefore, the model can be considered as a
method of predicting path length complexities; this is expected to lead
to minimum time complexity of very large-scale integrated circuitries
and related computer-aided design tools that use binary decision
diagrams.
Abstract: The purposes of this study are 1) to study the frequent
English writing errors of students registering the course: Reading and
Writing English for Academic Purposes II, and 2) to find out the
results of writing error correction by using coded indirect corrective
feedback and writing error treatments. Samples include 28 2nd year
English Major students, Faculty of Education, Suan Sunandha
Rajabhat University. Tool for experimental study includes the lesson
plan of the course; Reading and Writing English for Academic
Purposes II, and tool for data collection includes 4 writing tests of
short texts. The research findings disclose that frequent English
writing errors found in this course comprise 7 types of grammatical
errors, namely Fragment sentence, Subject-verb agreement, Wrong
form of verb tense, Singular or plural noun endings, Run-ons
sentence, Wrong form of verb pattern and Lack of parallel structure.
Moreover, it is found that the results of writing error correction by
using coded indirect corrective feedback and error treatment reveal
the overall reduction of the frequent English writing errors and the
increase of students’ achievement in the writing of short texts with
the significance at .05.
Abstract: Pineapples can be classified using an index with seven
levels of maturity based on the green and yellow color of the skin. As
the pineapple ripens, the skin will change from pale green to a golden
or yellowish color. The issues that occur in agriculture nowadays are
to do with farmers being unable to distinguish between the indexes of
pineapple maturity correctly and effectively. There are several
reasons for why farmers cannot properly follow the guideline provide
by Federal Agriculture Marketing Authority (FAMA) and one of
reason is that due to manual inspection done by experts, there are no
specific and universal guidelines to be adopted by farmers due to the
different points of view of the experts when sorting the pineapples
based on their knowledge and experience. Therefore, an automatic
system will help farmers to identify pineapple maturity effectively
and will become a universal indicator to farmers.
Abstract: Even though most researchers would agree that in
symbiotic relationships, like the one between parent and child,
influences become reciprocal over time, empirical evidence
supporting this claim is limited. The aim of the current study was to
develop and test a model describing the reciprocal influence between
characteristics of the parent-child relationship, such as closeness and
conflict, and the child-s bullying and victimization experiences at
school. The study used data from the longitudinal Study of Early
Child-Care, conducted by the National Institute of Child Health and
Human Development. The participants were dyads of early
adolescents (5th and 6th graders during the two data collection waves)
and their mothers (N=1364). Supporting our hypothesis, the findings
suggested a reciprocal association between bullying and positive
parenting, although this association was only significant for boys.
Victimization and positive parenting were not significantly
interrelated.
Abstract: In this paper we propose a new traffic simulation
package, TDMSim, which supports both macroscopic and
microscopic simulation on free-flowing and regulated traffic systems.
Both simulators are based on travel demands, which specify the
numbers of vehicles departing from origins to arrive at different
destinations. The microscopic simulator implements the carfollowing
model given the pre-defined routes of the vehicles but also
supports the rerouting of vehicles. We also propose a macroscopic
simulator which is built in integration with the microscopic simulator
to allow the simulation to be scaled for larger networks without
sacrificing the precision achievable through the microscopic
simulator. The macroscopic simulator also enables the reuse of
previous simulation results when simulating traffic on the same
networks at later time. Validations have been conducted to show the
correctness of both simulators.
Abstract: A boundary layer wind tunnel facility has been
adopted in order to conduct experimental measurements of the flow field around a model of the Panorama Giustinelli Building, Trieste
(Italy). Information on the main flow structures has been obtained by means of flow visualization techniques and has been compared to the
numerical predictions of the vortical structures spread on top of the roof, in order to investigate the optimal positioning for a vertical-axis
wind energy conversion system, registering a good agreement between experimental measurements and numerical predictions.
Abstract: The plastic forming process of sheet plate takes an
important place in forming metals. The traditional techniques of tool
design for sheet forming operations used in industry are experimental
and expensive methods. Prediction of the forming results,
determination of the punching force, blank holder forces and the
thickness distribution of the sheet metal will decrease the production
cost and time of the material to be formed. In this paper, multi-stage
deep drawing simulation of an Industrial Part has been presented
with finite element method. The entire production steps with
additional operations such as intermediate annealing and springback
has been simulated by ABAQUS software under axisymmetric
conditions. The simulation results such as sheet thickness
distribution, Punch force and residual stresses have been extracted in
any stages and sheet thickness distribution was compared with
experimental results. It was found through comparison of results, the
FE model have proven to be in close agreement with those of
experiment.
Abstract: Many methods exist for either measuring or estimating
evaporation from free water surfaces. Evaporation pans provide one
of the simplest, inexpensive, and most widely used methods of
estimating evaporative losses. In this study, the rate of evaporation
starting from a water surface was calculated by modeling with
application to dams in wet, arid and semi arid areas in Algeria.
We calculate the evaporation rate from the pan using the energy
budget equation, which offers the advantage of an ease of use, but
our results do not agree completely with the measurements taken by
the National Agency of areas carried out using dams located in areas
of different climates. For that, we develop a mathematical model to
simulate evaporation. This simulation uses an energy budget on the
level of a vat of measurement and a Computational Fluid Dynamics
(Fluent). Our calculation of evaporation rate is compared then by the
two methods and with the measures of areas in situ.
Abstract: This paper presents the design, analysis and
development of permanent magnet (PM) torque couplers. These
couplers employ rare-earth magnets. Based on finite element analysis
and earlier analytical works both concentric and face-type
synchronous type couplers have been designed and fabricated. The
experimental performance has good correlation with finite element
calculations.
Abstract: Rainfall data at fine resolution and knowledge of its
characteristics plays a major role in the efficient design and operation
of agricultural, telecommunication, runoff and erosion control as well
as water quality control systems. The paper is aimed to study the
statistical distribution of hourly rainfall depth for 12 representative
stations spread across Peninsular Malaysia. Hourly rainfall data of 10
to 22 years period were collected and its statistical characteristics
were estimated. Three probability distributions namely, Generalized
Pareto, Exponential and Gamma distributions were proposed to
model the hourly rainfall depth, and three goodness-of-fit tests,
namely, Kolmogorov-Sminov, Anderson-Darling and Chi-Squared
tests were used to evaluate their fitness. Result indicates that the east
cost of the Peninsular receives higher depth of rainfall as compared
to west coast. However, the rainfall frequency is found to be
irregular. Also result from the goodness-of-fit tests show that all the
three models fit the rainfall data at 1% level of significance.
However, Generalized Pareto fits better than Exponential and
Gamma distributions and is therefore recommended as the best fit.
Abstract: Friction-stir welding has received a huge interest in the last few years. The many advantages of this promising process have led researchers to present different theoretical and experimental explanation of the process. The way to quantitatively and qualitatively control the different parameters of the friction-stir welding process has not been paved. In this study, a refined energybased model that estimates the energy generated due to friction and plastic deformation is presented. The effect of the plastic deformation at low energy levels is significant and hence a scale factor is introduced to control its effect. The predicted heat energy and the obtained maximum temperature using our model are compared to the theoretical and experimental results available in the literature and a good agreement is obtained. The model is applied to AA6000 and AA7000 series.
Abstract: To achieve the desired specifications of gain and
phase margins for plants with time-delay that stabilized with FO-PID
controller a lead compensator is designed. At first the range of
controlled system stability based on stability boundary criteria is
determined. Using stability boundary locus method in frequency
domain the fractional order controller parameters are tuned and then
with drawing bode diagram in frequency domain accessing to desired
gain and phase margin are shown. Numerical examples are given to
illustrate the shapes of the stabilizing region and to show the design
procedure.
Abstract: This paper is concerned with propagation of thermoelastic longitudinal vibrations of an infinite circular cylinder, in the context of the linear theory of generalized thermoelasticity with two relaxation time parameters (Green and Lindsay theory). Three displacement potential functions are introduced to uncouple the equations of motion. The frequency equation, by using the traction free boundary conditions, is given in the form of a determinant involving Bessel functions. The roots of the frequency equation give the value of the characteristic circular frequency as function of the wave number. These roots, which correspond to various modes, are numerically computed and presented graphically for different values of the thermal relaxation times. It is found that the influences of the thermal relaxation times on the amplitudes of the elastic and thermal waves are remarkable. Also, it is shown in this study that the propagation of thermoelastic longitudinal vibrations based on the generalized thermoelasticity can differ significantly compared with the results under the classical formulation. A comparison of the results for the case with no thermal effects shows well agreement with some of the corresponding earlier results.
Abstract: In view of geological origin, formation of the shallow
gas reservoir of the Hangzhou Bay, northern Zhejiang Province,
eastern China, and original occurrence characteristics of the gassy
sand are analyzed. Generally, gassy sand in scale gas reservoirs is in
the state of residual moisture content and the approximate scope of
initial matric suction of sand ranges about from 0kPa to100kPa.
Results based on GDS triaxial tests show that the classical shear
strength formulas of unsaturated soil can not effectively describe basic
strength characteristics of gassy sand; the relationship between
apparent cohesion and matric suction of gassy sand agrees well with
the power function, which can reasonably be used to describe the
strength of gassy sand. In the stress path of gas release, shear strength
of gassy sand will increase and experimental results show the formula
proposed in this paper can effectively predict the strength increment.
When saturated strength indexes of the sand are used in engineering
design, moderate reduction should be considered.
Abstract: The present investigation was undertaken to explore the biogas potentiality of Jatropha (Jatropha curcas, Euphorbiaceae) Fruit Coat (JFC) alone and in combination with cattle dung (CD) in various proportions at 15 per cent total solids by batch phase anaerobic digestion for a period of ten weeks HRT (Hydraulic Retention Time) under a temperature of 35°C+1°C. The maximum biogas production was noticed in Cattle dung and Jatropha Fruit Coat in 2:1 ratio with 403.84 L/kg dry matter followed by 3:1,1:2, 1:1 and 1:3 having 329.66, 219.77, 217.79, 203.64 L /kg dm respectively as compared to 178.49 L/kg dm in CD alone. The JFC alone found to produce 91 per cent of total biogas that obtained from Cattle dung. The per cent methane content of the biogas in all the treatments was found on par with Cattle dung.