|Commenced in January 1999 || Frequency: Monthly || Edition: International|| Paper Count: 18 |
Mathematical, Computational, Physical, Electrical and Computer Engineering
Simulation of Water Droplet on Horizontally Smooth and Rough Surfaces Using Quasi-Molecular Modelling
We developed a method based on quasi-molecular
modelling to simulate the fall of water drops on horizontally smooth
and rough surfaces. Each quasi-molecule was a group of particles
that interacted in a fashion entirely analogous to classical Newtonian
molecular interactions. When a falling water droplet was simulated at
low impact velocity on both smooth and rough surfaces, the droplets
moved periodically (i.e. the droplets moved up and down for a
certain period, finally they stopped moving and reached a steady
state), spreading and recoiling without splash or break-up. Spreading
rates of falling water droplets increased rapidly as time increased
until the spreading rate reached its steady state at time t ~ 0.25 s for
rough surface and t ~ 0.40 s for smooth surface. The droplet height
above both surfaces decreased as time increased, remained constant
after the droplet diameter attained a maximum value and reached its
steady state at time t ~ 0.4 s. However, rough surface had higher
spreading rates of falling water droplets and lower height on the
surface than smooth one.
Quadrilateral Decomposition by Two-Ear Property Resulting in CAD Segmentation
The objective is to split a simply connected polygon
into a set of convex quadrilaterals without inserting new
boundary nodes. The presented approach consists in repeatedly
removing quadrilaterals from the polygon. Theoretical results
pertaining to quadrangulation of simply connected polygons are
derived from the usual 2-ear theorem. It produces a quadrangulation
technique with O(n) number of quadrilaterals. The
theoretical methodology is supplemented by practical results
and CAD surface segmentation.
Mathematical Model of Dengue Disease with the Incubation Period of Virus
Dengue virus is transmitted from person to person
through the biting of infected Aedes Aegypti mosquitoes. DEN-1,
DEN-2, DEN-3 and DEN-4 are four serotypes of this virus. Infection
with one of these four serotypes apparently produces permanent
immunity to it, but only temporary cross immunity to the others. The
length of time during incubation of dengue virus in human and
mosquito are considered in this study. The dengue patients are
classified into infected and infectious classes. The infectious human
can transmit dengue virus to susceptible mosquitoes but infected
human can not. The transmission model of this disease is formulated.
The human population is divided into susceptible, infected, infectious
and recovered classes. The mosquito population is separated into
susceptible, infected and infectious classes. Only infectious
mosquitoes can transmit dengue virus to the susceptible human. We
analyze this model by using dynamical analysis method. The
threshold condition is discussed to reduce the outbreak of this
Gabriel-constrained Parametric Surface Triangulation
The Boundary Representation of a 3D manifold contains
FACES (connected subsets of a parametric surface S : R2 -!
R3). In many science and engineering applications it is cumbersome
and algebraically difficult to deal with the polynomial set and
constraints (LOOPs) representing the FACE. Because of this reason, a
Piecewise Linear (PL) approximation of the FACE is needed, which is
usually represented in terms of triangles (i.e. 2-simplices). Solving the
problem of FACE triangulation requires producing quality triangles
which are: (i) independent of the arguments of S, (ii) sensitive to the
local curvatures, and (iii) compliant with the boundaries of the FACE
and (iv) topologically compatible with the triangles of the neighboring
FACEs. In the existing literature there are no guarantees for the point
(iii). This article contributes to the topic of triangulations conforming
to the boundaries of the FACE by applying the concept of parameterindependent
Gabriel complex, which improves the correctness of the
triangulation regarding aspects (iii) and (iv). In addition, the article
applies the geometric concept of tangent ball to a surface at a point to
address points (i) and (ii). Additional research is needed in algorithms
that (i) take advantage of the concepts presented in the heuristic
algorithm proposed and (ii) can be proved correct.
Dengue Transmission Model between Infantand Pregnant Woman with Antibody
Dengue, a disease found in most tropical and
subtropical areas of the world. It has become the most common
arboviral disease of humans. This disease is caused by any of four
serotypes of dengue virus (DEN1-DEN4). In many endemic
countries, the average age of getting dengue infection is shifting
upwards, dengue in pregnancy and infancy are likely to be
encountered more frequently. The dynamics of the disease is studied
by a compartmental model involving ordinary differential equations
for the pregnant, infant human and the vector populations. The
stability of each equilibrium point is given. The epidemic dynamic is
discussed. Moreover, the numerical results are shown for difference
values of dengue antibody.
Stochastic Resonance in Nonlinear Signal Detection
Stochastic resonance (SR) is a phenomenon whereby
the signal transmission or signal processing through certain nonlinear
systems can be improved by adding noise. This paper discusses SR in
nonlinear signal detection by a simple test statistic, which can be
computed from multiple noisy data in a binary decision problem based
on a maximum a posteriori probability criterion. The performance of
detection is assessed by the probability of detection error Per . When
the input signal is subthreshold signal, we establish that benefit from
noise can be gained for different noises and confirm further that the
subthreshold SR exists in nonlinear signal detection. The efficacy of
SR is significantly improved and the minimum of Per can
dramatically approach to zero as the sample number increases. These
results show the robustness of SR in signal detection and extend the
applicability of SR in signal processing.
Research on the Survivability of Embedded Real-time System
Introducing survivability into embedded real-time system (ERTS) can improve the survivability power of the system. This paper mainly discusses about the survivability of ERTS. The first is the survivability origin of ERTS. The second is survivability analysis. According to the definition of survivability based on survivability specification and division of the entire survivability analysis process for ERTS, a survivability analysis profile is presented. The quantitative analysis model of this profile is emphasized and illuminated in detail, the quantifying analysis of system was showed helpful to evaluate system survivability more accurate. The third is platform design of survivability analysis. In terms of the profile, the analysis process is encapsulated and assembled into one platform, on which quantification, standardization and simplification of survivability analysis are all achieved. The fourth is survivability design. According to character of ERTS, strengthened design method is selected to realize system survivability design. Through the analysis of embedded mobile video-on-demand system, intrusion tolerant technology is introduced in whole survivability design.
Adaptation of Iterative Methods to Solve Fuzzy Mathematical Programming Problems
Based on the fuzzy set theory this work develops two
adaptations of iterative methods that solve mathematical programming
problems with uncertainties in the objective function and in
the set of constraints. The first one uses the approach proposed by
Zimmermann to fuzzy linear programming problems as a basis and
the second one obtains cut levels and later maximizes the membership
function of fuzzy decision making using the bound search method.
We outline similarities between the two iterative methods studied.
Selected examples from the literature are presented to validate the
efficiency of the methods addressed.
A New Vision of Fractal Geometry with Triangulati on Algorithm
L-system is a tool commonly used for modeling and simulating the growth of fractal plants. The aim of this paper is to join some problems of the computational geometry with the fractal geometry by using the L-system technique to generate fractal plant in 3D. L-system constructs the fractal structure by applying rewriting rules sequentially and this technique depends on recursion process with large number of iterations to get different shapes of 3D fractal plants. Instead, it was reiterated a specific number of iterations up to three iterations. The vertices generated from the last stage of the Lsystem rewriting process are used as input to the triangulation algorithm to construct the triangulation shape of these vertices. The resulting shapes can be used as covers for the architectural objects and in different computer graphics fields. The paper presents a gallery of triangulation forms which application in architecture creates an alternative for domes and other traditional types of roofs.
Two Spatial Experiments based on Computational Geometry
The paper outlines the relevance of computational
geometry within the design and production process of architecture.
Based on two case studies, the digital chain - from the initial formfinding
to the final realization of spatial concepts - is discussed in
relation to geometric principles. The association with the fascinating
complexity that can be found in nature and its underlying geometry
was the starting point for both projects presented in the paper. The
translation of abstract geometric principles into a three-dimensional
digital design model – realized in Rhinoceros – was followed by a
process of transformation and optimization of the initial shape that
integrated aesthetic, spatial and structural qualities as well as aspects
of material properties and conditions of production.
Application of the Neural Network to the Synthesis of Multibeam Antennas Arrays
In this paper, we intend to study the synthesis of the
multibeam arrays. The synthesis implementation-s method for this
type of arrays permits to approach the appropriated radiance-s
diagram. The used approach is based on neural network that are
capable to model the multibeam arrays, consider predetermined
general criteria-s, and finally it permits to predict the appropriated
diagram from the neural model. Our main contribution in this paper is
the extension of a synthesis model of these multibeam arrays.
The Comparison of Finite Difference Methods for Radiation Diffusion Equations
In this paper, the difference between the Alternating
Direction Method (ADM) and the Non-Splitting Method (NSM) is
investigated, while both methods applied to the simulations for 2-D
multimaterial radiation diffusion issues. Although the ADM have the
same accuracy orders with the NSM on the uniform meshes, the
accuracy of ADM will decrease on the distorted meshes or the
boundary of domain. Numerical experiments are carried out to
confirm the theoretical predication.
Long-Range Dependence of Financial Time Series Data
This paper examines long-range dependence or longmemory
of financial time series on the exchange rate data by the
fractional Brownian motion (fBm). The principle of spectral density
function in Section 2 is used to find the range of Hurst parameter (H)
of the fBm. If 0< H
Human Pose Estimation using Active Shape Models
Human pose estimation can be executed using Active Shape Models. The existing techniques for applying to human-body research using Active Shape Models, such as human detection, primarily take the form of silhouette of human body. This technique is not able to estimate accurately for human pose to concern two arms and legs, as the silhouette of human body represents the shape as out of round. To solve this problem, we applied the human body model as stick-figure, “skeleton". The skeleton model of human body can give consideration to various shapes of human pose. To obtain effective estimation result, we applied background subtraction and deformed matching algorithm of primary Active Shape Models in the fitting process. The images which were used to make the model were 600 human bodies, and the model has 17 landmark points which indicate body junction and key features of human pose. The maximum iteration for the fitting process was 30 times and the execution time was less than .03 sec.
Plasmodium Vivax Malaria Transmission in a Network of Villages
Malaria is a serious, acute and chronic relapsing
infection to humans. It is characterized by periodic attacks of chills,
fever, nausea, vomiting, back pain, increased sweating anemia,
splenomegaly (enlargement of the spleen) and often-fatal
complications.The malaria disease is caused by the multiplication of
protozoa parasite of the genus Plasmodium. Malaria in humans is due
to 4 types of malaria parasites such that Plasmodium falciparum,
Plasmodium vivax, Plasmodium malariae and Plasmodium ovale.
P.vivax malaria differs from P. falciparum malaria in that a person
suffering from P. vivax malaria can experience relapses of the
disease. Between the relapses, the malaria parasite will remain
dormant in the liver of the patient, leading to the patient being
classified as being in the dormant class. A mathematical model for
the transmission of P. vivax is developed in which the human
population is divided into four classes, the susceptible, the infected,
the dormant and the recovered. In this paper, we formulate the
dynamical model of P. vivax malaria to see the distribution of this
disease at the district level.
Fuzzy Cost Support Vector Regression
In this paper, a new version of support vector regression (SVR) is presented namely Fuzzy Cost SVR (FCSVR). Individual property of the FCSVR is operation over fuzzy data whereas fuzzy cost (fuzzy margin and fuzzy penalty) are maximized. This idea admits to have uncertainty in the penalty and margin terms jointly. Robustness against noise is shown in the experimental results as a property of the proposed method and superiority relative conventional SVR.
Arc Length of Rational Bezier Curves and Use for CAD Reparametrization
The length of a given rational B'ezier curve is
efficiently estimated. Since a rational B'ezier function is nonlinear,
it is usually impossible to evaluate its length exactly. The
length is approximated by using subdivision and the accuracy
of the approximation n is investigated. In order to improve
the efficiency, adaptivity is used with some length estimator.
A rigorous theoretical analysis of the rate of convergence of
n to is given. The required number of subdivisions to
attain a prescribed accuracy is also analyzed. An application
to CAD parametrization is briefly described. Numerical results
are reported to supplement the theory.
Analysis of Model in Pregnant and Non-Pregnant Dengue Patients
We used mathematical model to study the
transmission of dengue disease. The model is developed in which
the human population is separated into two populations, pregnant and
non-pregnant humans. The dynamical analysis method is used for
analyzing this modified model. Two equilibrium states are found and
the conditions for stability of theses two equilibrium states are
established. Numerical results are shown for each equilibrium state.
The basic reproduction numbers are found and they are compared by
using numerical simulations.