Abstract: Today air-core coils (ACC) are a viable alternative to
ferrite-core coils in a range of applications due to their low induction
effect. An analytical study was carried out and the results were used as
a guide to understand the relationship between the magnet-coil
distance and the resulting attractive magnetic force. Four different
ACC models were fabricated for experimental study. The variation in
the models included the dimensions, the number of coil turns and the
current supply to the coil. Comparison between the analytical and
experimental results for all the models shows an average discrepancy
of less than 10%. An optimized ACC design was selected for the
scanner which can provide maximum magnetic force.
Abstract: Dynamic bandwidth allocation in EPONs can be
generally separated into inter-ONU scheduling and intra-ONU scheduling. In our previous work, the active intra-ONU scheduling
(AS) utilizes multiple queue reports (QRs) in each report message to cooperate with the inter-ONU scheduling and makes the granted
bandwidth fully utilized without leaving unused slot remainder (USR).
This scheme successfully solves the USR problem originating from the
inseparability of Ethernet frame. However, without proper setting of
threshold value in AS, the number of QRs constrained by the IEEE
802.3ah standard is not enough, especially in the unbalanced traffic
environment. This limitation may be solved by enlarging the threshold
value. The large threshold implies the large gap between the adjacent QRs, thus resulting in the large difference between the best granted bandwidth and the real granted bandwidth. In this paper, we integrate
AS with a cooperative prediction mechanism and distribute multiple
QRs to reduce the penalty brought by the prediction error.
Furthermore, to improve the QoS and save the usage of queue reports,
the highest priority (EF) traffic which comes during the waiting time is
granted automatically by OLT and is not considered in the requested
bandwidth of ONU. The simulation results show that the proposed
scheme has better performance metrics in terms of bandwidth
utilization and average delay for different classes of packets.
Abstract: This paper describes a new method for affine parameter
estimation between image sequences. Usually, the parameter
estimation techniques can be done by least squares in a quadratic
way. However, this technique can be sensitive to the presence
of outliers. Therefore, parameter estimation techniques for various
image processing applications are robust enough to withstand the
influence of outliers. Progressively, some robust estimation functions
demanding non-quadratic and perhaps non-convex potentials adopted
from statistics literature have been used for solving these. Addressing
the optimization of the error function in a factual framework for
finding a global optimal solution, the minimization can begin with
the convex estimator at the coarser level and gradually introduce nonconvexity
i.e., from soft to hard redescending non-convex estimators
when the iteration reaches finer level of multiresolution pyramid.
Comparison has been made to find the performance of the results
of proposed method with the results found individually using two
different estimators.
Abstract: In this paper, a joint source-channel coding (JSCC) scheme for time-varying channels is presented. The proposed scheme uses hierarchical framework for both source encoder and transmission via QAM modulation. Hierarchical joint source channel codes with hierarchical QAM constellations are designed to track the channel variations which yields to a higher throughput by adapting certain parameters of the receiver to the channel variation. We consider the problem of still image transmission over time-varying channels with channel state information (CSI) available at 1) receiver only and 2) both transmitter and receiver being informed about the state of the channel. We describe an algorithm that optimizes hierarchical source codebooks by minimizing the distortion due to source quantizer and channel impairments. Simulation results, based on image representation, show that, the proposed hierarchical system outperforms the conventional schemes based on a single-modulator and channel optimized source coding.
Abstract: This article presents a computationally tractable probabilistic model for the relation between the complex wavelet coefficients of two images of the same scene. The two images are acquisitioned at distinct moments of times, or from distinct viewpoints, or by distinct sensors. By means of the introduced probabilistic model, we argue that the similarity between the two images is controlled not by the values of the wavelet coefficients, which can be altered by many factors, but by the nature of the wavelet coefficients, that we model with the help of hidden state variables. We integrate this probabilistic framework in the construction of a new image registration algorithm. This algorithm has sub-pixel accuracy and is robust to noise and to other variations like local illumination changes. We present the performance of our algorithm on various image types.
Abstract: Water 2H NMR signal on the surface of nano-silica material, MCM-41, consists of two overlapping resonances. The 2H water spectrum shows a superposition of a Lorentzian line shape and the familiar NMR powder pattern line shape, indicating the existence of two spin components. Chemical exchange occurs between these two groups. Decomposition of the two signals is a crucial starting point for study the exchange process. In this article we have determined these spin component populations along with other important parameters for the 2H water NMR signal over a temperature range between 223 K and 343 K.
Abstract: This paper presents a comparison of average outgoing
quality limit of the MCSP-2-C plan with MCSP-C when MCSP-2-C
has been developed from MCSP-C. The parameters used in MCSP-2-
C are: i (the clearance number), c (the acceptance number), m (the
number of conforming units to be found before allowing c nonconforming
units in the sampling inspection), f1 and f2 (the sampling
frequency at level 1 and 2, respectively). The average outgoing
quality limit (AOQL) values from two plans were compared and we
found that for all sets of i, r, and c values, MCSP-2-C gives higher
values than MCSP-C. For all sets of i, r, and c values, the average
outgoing quality values of MCSP-C and MCSP-2-C are similar when
p is low or high but is difference when p is moderate.
Abstract: Conventional concentrically-braced frame (CBF)
systems have limited drift capacity before brace buckling and related
damage leads to deterioration in strength and stiffness. Self-centering
concentrically-braced frame (SC-CBF) systems have been developed
to increase drift capacity prior to initiation of damage and minimize
residual drift. SC-CBFs differ from conventional CBFs in that the
SC-CBF columns are designed to uplift from the foundation at a
specified level of lateral loading, initiating a rigid-body rotation
(rocking) of the frame. Vertically-aligned post-tensioning bars resist
uplift and provide a restoring force to return the SC-CBF columns to
the foundation (self-centering the system). This paper presents a
parametric study of different prototype buildings using SC-CBFs.
The bay widths of the SC-CBFs have been varied in these buildings
to study different geometries. Nonlinear numerical analyses of the
different SC-CBFs are presented to illustrate the effect of frame
geometry on the behavior and dynamic response of the SC-CBF
system.
Abstract: An appropriate project delivery system (PDS) is crucial
to the success of a construction projects. Case-based Reasoning (CBR)
is a useful support for PDS selection. However, the traditional CBR
approach represents cases as attribute-value vectors without taking
relations among attributes into consideration, and could not calculate
the similarity when the structures of cases are not strictly same.
Therefore, this paper solves this problem by adopting the Relational
Case-based Reasoning (RCBR) approach for PDS selection,
considering both the structural similarity and feature similarity. To
develop the feature terms of the construction projects, the criteria and
factors governing PDS selection process are first identified. Then
feature terms for the construction projects are developed. Finally, the
mechanism of similarity calculation and a case study indicate how
RCBR works for PDS selection. The adoption of RCBR in PDS
selection expands the scope of application of traditional CBR method
and improves the accuracy of the PDS selection system.
Abstract: Metal matrix composites (MMC) are generating
extensive interest in diverse fields like defense, aerospace, electronics
and automotive industries. In this present investigation, material
removal rate (MRR) modeling has been carried out using an
axisymmetric model of Al-SiC composite during electrical discharge
machining (EDM). A FEA model of single spark EDM was
developed to calculate the temperature distribution.Further, single
spark model was extended to simulate the second discharge. For
multi-discharge machining material removal was calculated by
calculating the number of pulses. Validation of model has been done
by comparing the experimental results obtained under the same
process parameters with the analytical results. A good agreement was
found between the experimental results and the theoretical value.
Abstract: This paper presents a new strategy of identification
and classification of pathological voices using the hybrid method
based on wavelet transform and neural networks. After speech
acquisition from a patient, the speech signal is analysed in order to
extract the acoustic parameters such as the pitch, the formants, Jitter,
and shimmer. Obtained results will be compared to those normal and
standard values thanks to a programmable database. Sounds are
collected from normal people and patients, and then classified into
two different categories. Speech data base is consists of several
pathological and normal voices collected from the national hospital
“Rabta-Tunis". Speech processing algorithm is conducted in a
supervised mode for discrimination of normal and pathology voices
and then for classification between neural and vocal pathologies
(Parkinson, Alzheimer, laryngeal, dyslexia...). Several simulation
results will be presented in function of the disease and will be
compared with the clinical diagnosis in order to have an objective
evaluation of the developed tool.
Abstract: In this paper, a method for matching image segments
using triangle-based (geometrical) regions is proposed. Triangular
regions are formed from triples of vertex points obtained from a
keypoint detector (SIFT). However, triangle regions are subject to
noise and distortion around the edges and vertices (especially acute
angles). Therefore, these triangles are expanded into parallelogramshaped
regions. The extracted image segments inherit an important
triangle property; the invariance to affine distortion. Given two
images, matching corresponding regions is conducted by computing
the relative affine matrix, rectifying one of the regions w.r.t. the other
one, then calculating the similarity between the reference and
rectified region. The experimental tests show the efficiency and
robustness of the proposed algorithm against geometrical distortion.
Abstract: Segmentation, filtering out of measurement errors and
identification of breakpoints are integral parts of any analysis of
microarray data for the detection of copy number variation (CNV).
Existing algorithms designed for these tasks have had some successes
in the past, but they tend to be O(N2) in either computation time or
memory requirement, or both, and the rapid advance of microarray
resolution has practically rendered such algorithms useless. Here we
propose an algorithm, SAD, that is much faster and much less thirsty
for memory – O(N) in both computation time and memory requirement
-- and offers higher accuracy. The two key ingredients of SAD are the
fundamental assumption in statistics that measurement errors are
normally distributed and the mathematical relation that the product of
two Gaussians is another Gaussian (function). We have produced a
computer program for analyzing CNV based on SAD. In addition to
being fast and small it offers two important features: quantitative
statistics for predictions and, with only two user-decided parameters,
ease of use. Its speed shows little dependence on genomic profile.
Running on an average modern computer, it completes CNV analyses
for a 262 thousand-probe array in ~1 second and a 1.8 million-probe
array in 9 seconds
Abstract: Food control measures are critical in fostering food safety management of a nation. However, no academic study has been undertaken to assess the food control system of Myanmar up to now. The objective of this research paper was to assess the food control system with in depth examination of five key components using desktop analysis and short survey from related food safety program organizations including regulators and inspectors. Study showed that the existing food control system is conventional, mainly focusing on primary health care approach while relying on reactive measures. The achievements of food control work have been limited to a certain extent due to insufficienttechnical capacity that is needed to upgrade staffs, laboratory equipment and technical assistance etc. associated with various sectors. Assessing food control measures is the first step in the integration of food safety management, this paper could assist policy makers in providing information for enhancing the safety and quality of food produced and consumed in Myanmar.
Abstract: Graph transformation has recently become more and
more popular as a general visual modeling language to formally state
the dynamic semantics of the designed models. Especially, it is a
very natural formalism for languages which basically are graph (e.g.
UML). Using this technique, we present a highly understandable yet
precise approach to formally model and analyze the behavioral
semantics of UML 2.0 Activity diagrams. In our proposal, AGG is
used to design Activities, then using our previous approach to model
checking graph transformation systems, designers can verify and
analyze designed Activity diagrams by checking the interesting
properties as combination of graph rules and LTL (Linear Temporal
Logic) formulas on the Activities.
Abstract: A simple and easy algorithm is presented for a fast calculation of kernel functions which required in fluid simulations using the Smoothed Particle Hydrodynamic (SPH) method. Present proposed algorithm improves the Linked-list algorithm and adopts the Pair-Wise Interaction technique, which are widely used for evaluating kernel functions in fluid simulations using the SPH method. The algorithm is easy to be implemented without any complexities in programming. Some benchmark examples are used to show the simulation time saved by using the proposed algorithm. Parametric studies on the number of divisions for sub-domains, smoothing length and total amount of particles are conducted to show the effectiveness of the present technique. A compact formulation is proposed for practical usage.
Abstract: AAM (active appearance model) has been successfully
applied to face and facial feature localization. However, its performance is sensitive to initial parameter values. In this paper, we propose a two-stage AAM for robust face alignment, which first fits an
inner face-AAM model to the inner facial feature points of the face and then localizes the whole face and facial features by optimizing the
whole face-AAM model parameters. Experiments show that the proposed face alignment method using two-stage AAM is more reliable to the background and the head pose than the standard
AAM-based face alignment method.
Abstract: The motion of a sphere moving along the axis of a
rotating viscous fluid is studied at high Reynolds numbers and
moderate values of Taylor number. The Higher Order Compact
Scheme is used to solve the governing Navier-Stokes equations. The
equations are written in the form of Stream function, Vorticity
function and angular velocity which are highly non-linear, coupled
and elliptic partial differential equations. The flow is governed by
two parameters Reynolds number (Re) and Taylor number (T). For
very low values of Re and T, the results agree with the available
experimental and theoretical results in the literature. The results are
obtained at higher values of Re and moderate values of T and
compared with the experimental results. The results are fourth order
accurate.
Abstract: Carbon steel is used in boilers, pressure vessels, heat
exchangers, piping, structural elements and other moderatetemperature
service systems in which good strength and ductility are
desired. ASME Boiler and Pressure Vessel Code, Section II Part A
(2004) provides specifications of ferrous materials for construction of
pressure equipment, covering wide range of mechanical properties
including high strength materials for power plants application.
However, increased level of springback is one of the major problems
in fabricating components of high strength steel using bending.
Presented work discuss the springback simulations for five different
steels (i.e. SA-36, SA-299, SA-515 grade 70, SA-612 and SA-724
grade B) using finite element analysis of air V-bending. Analytical
springback simulations of hypothetical layered materials are
presented. Result shows that; (i) combination of the material property
parameters controls the springback, (ii) layer of the high ductility
steel on the high strength steel greatly suppresses the springback.
Abstract: In online context, the design and implementation of
effective remote laboratories environment is highly challenging on
account of hardware and software needs. This paper presents the
remote laboratory software framework modified from ilab shared
architecture (ISA). The ISA is a framework which enables students to
remotely acccess and control experimental hardware using internet
infrastructure. The need for remote laboratories came after
experiencing problems imposed by traditional laboratories. Among
them are: the high cost of laboratory equipment, scarcity of space,
scarcity of technical personnel along with the restricted university
budget creates a significant bottleneck on building required
laboratory experiments. The solution to these problems is to build
web-accessible laboratories. Remote laboratories allow students and
educators to interact with real laboratory equipment located
anywhere in the world at anytime. Recently, many universities and
other educational institutions especially in third world countries rely
on simulations because they do not afford the experimental
equipment they require to their students. Remote laboratories enable
users to get real data from real-time hand-on experiments. To
implement many remote laboratories, the system architecture should
be flexible, understandable and easy to implement, so that different
laboratories with different hardware can be deployed easily. The
modifications were made to enable developers to add more
equipment in ISA framework and to attract the new developers to
develop many online laboratories.