Abstract: Voice over Internet Protocol (VoIP) is a form of voice
communication that uses audio data to transmit voice signals to the
end user. VoIP is one of the most important technologies in the
World of communication. Around, 20 years of research on VoIP,
some problems of VoIP are still remaining. During the past decade
and with growing of wireless technologies, we have seen that many
papers turn their concentration from Wired-LAN to Wireless-LAN.
VoIP over Wireless LAN (WLAN) faces many challenges due to the
loose nature of wireless network. Issues like providing Quality of
Service (QoS) at a good level, dedicating capacity for calls and
having secure calls is more difficult rather than wired LAN.
Therefore VoIP over WLAN (VoWLAN) remains a challenging
research topic. In this paper we consolidate and address major
VoWLAN issues. This research is helpful for those researchers wants
to do research in Voice over IP technology over WLAN network.
Abstract: This paper presents a rule-based text- to- speech
(TTS) Synthesis System for Standard Malay, namely SMaTTS. The
proposed system using sinusoidal method and some pre- recorded
wave files in generating speech for the system. The use of phone
database significantly decreases the amount of computer memory
space used, thus making the system very light and embeddable. The
overall system was comprised of two phases the Natural Language
Processing (NLP) that consisted of the high-level processing of text
analysis, phonetic analysis, text normalization and morphophonemic
module. The module was designed specially for SM to overcome
few problems in defining the rules for SM orthography system before
it can be passed to the DSP module. The second phase is the Digital
Signal Processing (DSP) which operated on the low-level process of
the speech waveform generation. A developed an intelligible and
adequately natural sounding formant-based speech synthesis system
with a light and user-friendly Graphical User Interface (GUI) is
introduced. A Standard Malay Language (SM) phoneme set and an
inclusive set of phone database have been constructed carefully for
this phone-based speech synthesizer. By applying the generative
phonology, a comprehensive letter-to-sound (LTS) rules and a
pronunciation lexicon have been invented for SMaTTS. As for the
evaluation tests, a set of Diagnostic Rhyme Test (DRT) word list was
compiled and several experiments have been performed to evaluate
the quality of the synthesized speech by analyzing the Mean Opinion
Score (MOS) obtained. The overall performance of the system as
well as the room for improvements was thoroughly discussed.
Abstract: An application framework provides a reusable design
and implementation for a family of software systems. Application
developers extend the framework to build their particular
applications using hooks. Hooks are the places identified to show
how to use and customize the framework. Hooks define the
Framework Interface Classes (FICs) and the specifications of their
methods. As part of the development life cycle, it is required to test
the implementations of the FICs. Building a testing model to express
the behavior of a class is an essential step for the generation of the
class-based test cases. The testing model has to be consistent with the
specifications provided for the hooks. State-based models consisting
of states and transitions are testing models well suited to objectoriented
software. Typically, hand-construction of a state-based
model of a class behavior is expensive, error-prone, and may result in
constructing an inconsistent model with the specifications of the class
methods, which misleads verification results. In this paper, a
technique is introduced to automatically synthesize a state-based
testing model for FICs using the specifications provided for the
hooks. A tool that supports the proposed technique is introduced.
Abstract: For a quick and accurate calculation of spatial neutron
distribution in nuclear power reactors 3D nodal codes are usually
used aiming at solving the neutron diffusion equation for a given
reactor core geometry and material composition. These codes use a
second order polynomial to represent the transverse leakage term. In
this work, a nodal method based on the well known nodal expansion
method (NEM), developed at COPPE, making use of this polynomial
expansion was modified to treat the transverse leakage term for the
external surfaces of peripheral reflector nodes.
The proposed method was implemented into a computational
system which, besides solving the diffusion equation, also solves the
burnup equations governing the gradual changes in material
compositions of the core due to fuel depletion. Results confirm the
effectiveness of this modified treatment of peripheral nodes for
practical purposes in PWR reactors.
Abstract: This paper describes a combined mathematicalgraphical
approach for optimum tool path planning in order to
improve machining efficiency. A methodology has been used that
stabilizes machining operations by adjusting material removal rate in
pocket milling operations while keeping cutting forces within limits.
This increases the life of cutting tool and reduces the risk of tool
breakage, machining vibration, and chatter. Case studies reveal the
fact that application of this approach could result in a slight increase
of machining time, however, a considerable reduction of tooling cost,
machining vibration, noise and chatter can be achieved in addition to
producing a better surface finish.
Abstract: Innovational development of regions in Russia is generally faced with the essential influence from federal and local authorities. The organization of effective mechanism of innovation development (and self-development) is impossible without establishment of defined institutional conditions in the analyzed field. Creative utilization of scientific concepts and information should merge, giving rise to continuing innovation and advanced production. The paper presents an analysis of institutional conditions in the field of creation and development of innovation activity infrastructure and transferring of knowledge and skills between different economic agents in Russia. Knowledge is mainly privately owned, developed through R&D investments and incorporated into technology or a product. Innovation infrastructure is a strong concentration mechanism of advanced facilities, which are mainly located inside large agglomerations or city-regions in order to benefit from scale effects in both input markets (human capital, private financial capital) and output markets (higher education services, research services). The empirical results of the paper show that in the presence of more efficient innovation and knowledge transfer and transcoding system and of a more open attitude of economic agents towards innovation, the innovation and knowledge capacity of regional economy is much higher.
Abstract: The use of contour strips of perennial vegetation with
bio-fuel potential can improve surface water quality by reducing
NO3-N and sediment outflow from cropland to surface water-bodies.
It also has economic benefits of producing ethanol. In this study,
The Soil and Water Assessment Tool (SWAT) model was applied to
a watershed in Iowa, USA to examine the effectiveness of contour
strips of switch grass in reducing the NO3-N outflows from crop
fields to rivers or lakes. Numerical experiments were conducted to
identify potential subbasins in the watershed that have high water
quality impact, and to examine the effects of strip size on NO3-N
reduction under various meteorological conditions, i.e. dry, average
and wet years. Useful information was obtained for the evaluation of
economic feasibility of growing switch grass for bio-fuel in contour
strips. The results can assist in cost-benefit analysis and decisionmaking
in best management practices for environmental protection.
Abstract: The present work is concerned with the free
convective two dimensional flow and heat transfer, in isotropic fluid
filled porous rectangular enclosure with differentially heated walls for
steady state incompressible flow have been investigated for non-
Darcy flow model. Effects of Darcy number (0.0001 £Da£ 10),
Rayleigh number (10 £Ra£ 5000), and aspect ratio (0.25 £AR£ 4), for
a range of porosity (0.4 £e£ 0.9) with and without moving lower wall
have been studied. The cavity was insulated at the lower and upper
surfaces. The right and left heated surfaces allows convective
transport through the porous medium, generating a thermal
stratification and flow circulations. It was found that the Darcy
number, Rayleigh number, aspect ratio, and porosity considerably
influenced characteristics of flow and heat transfer mechanisms. The
results obtained are discussed in terms of the Nusselt number,
vectors, contours, and isotherms.
Abstract: This paper presents the experimental results on
ageing deterioration of silicone rubber outdoor polymer insulator
under salt water dip wheel test based on IEC 62217. In order to comparison effect of chemical contents, silicone rubber outdoor
polymer insulators having same configuration and leakage distant
from two manufactures were tested together continuously 30,000 test cycles. Many discharge activities were observed in during the test.
After 30,000 test cycles, in spite of same configuration, differences in
degree of surface aging were observed. Physical analysis such as
decreasing in hydrophobicity and increasing in hardness
measurement were measured on two-type tested specimen surface in order to confirm degree of surface ageing. Furthermore, chemical
analysis by ATR-FTIR to diagnose the chemical change of tested
specimen surface was conducted to confirm the physical analysis results.
Abstract: Microbial contamination, most of which are fecal born in drinking water and food industry is a serious threat to humans. Escherichia coli is one of the most common and prevalent among them. We have developed a sensor for rapid and an early detection of contaminants, taking E.coli as a threat indicator organism. The sensor is based on co-polymerizations of aniline and formaldehyde in form of thin film over glass surface using the vacuum deposition technique. The particular doping combination of thin film with Fe-Al and Fe-Cu in different concentrations changes its non conducting properties to p- type semi conductor. This property is exploited to detect the different contaminants, believed to have the different surface charge. It was found through experiments that different microbes at same OD (0.600 at 600 nm) have different conductivity in solution. Also the doping concentration is found to be specific for attracting microbes on the basis of surface charge. This is a simple, cost effective and quick detection method which not only decreases the measurement time but also gives early warnings for highly contaminated samples.
Abstract: Mobiles are considered to be the most frequently used
electronic items in world after electricity. It is probably the only
device that can be used by any gender with no age limits depending
on its functionality. This paper present the interactive interface of
Mobile and particularly aiming the use of advanced phones which are
also called smart phones. With the changes in the trend where users
are now moving from ordinary mobiles to the one with touch screens
and facilities such as WiFi and internet browsing.
Abstract: In this paper, the babbitting of a bearing in boiler feed pump of an electromotor has been studied. These bearings have an important role in reducing the shut down times in the pumps, compressors and turbines. The most conventional method in babbitting is casting as a melting method. The comparison between thermal spray and casting methods in babbitting shows that the thermal spraying babbitt layer has better performance and tribological behavior. The metallurgical and tribological analysis such as SEM, EDS and wet chemical analysis has been made in the Babbitt alloys and worn surfaces. Two type of babbitt materials: tinbase and lead-base babbitt was used. The benefits of thermally sprayed babbitt layers are completely clear especially in large bearings.
Abstract: Titanium dioxide coatings were deposited by utilizing
atmospheric plasma spraying (APS) system. The agglomerated nanopowder
and different spraying parameters were used to determine
their influences on the microstructure surface feature and photoabsorption
of the coatings. The microstructure of as-sprayed TiO2
coatings were characterized by scanning electron microscope (SEM).
Surface characteristics were investigated by Fourier Transform
Infrared (FT-IR). The photo absorption was determined by UV-VIS
spectrophotometer. It is found that the spray parameters have an
influence on the microstructure, surface feature and photo-absorption
of the TiO2 coatings.
Abstract: This paper presents unified theory for local (Savitzky-
Golay) and global polynomial smoothing. The algebraic framework
can represent any polynomial approximation and is seamless from
low degree local, to high degree global approximations. The representation
of the smoothing operator as a projection onto orthonormal
basis functions enables the computation of: the covariance matrix
for noise propagation through the filter; the noise gain and; the
frequency response of the polynomial filters. A virtually perfect Gram
polynomial basis is synthesized, whereby polynomials of degree
d = 1000 can be synthesized without significant errors. The perfect
basis ensures that the filters are strictly polynomial preserving. Given
n points and a support length ls = 2m + 1 then the smoothing
operator is strictly linear phase for the points xi, i = m+1. . . n-m.
The method is demonstrated on geometric surfaces data lying on an
invariant 2D lattice.
Abstract: Nanowire arrays of copper with uniform diameters have
been synthesized by potentiostatic electrochemical metal deposition
(EMD) of copper sulphate and potassium chloride solution within
the nano-channels of porous Indium-Tin Oxide (ITO), also known as
Tin doped Indium Oxide templates. The nanowires developed were
fairly continuous with diameters ranging from 110-140 nm along
the entire length. Single as well as poly-crystalline copper wires
have been prepared by application of appropriate potential during the
EMD process. Scanning electron microscopy (SEM), high resolution
transmission electron microscopy (HRTEM), small angle electron
diffraction (SAED) and atomic force microscopy (AFM) were used
to characterize the synthesized nano wires at room temperature. The
electrochemical response of synthesized products was evaluated by
cyclic voltammetry while surface energy analysis was carried out
using a Goniometer.
Abstract: The gel-supported precipitation (GSP) process can be
used to make spherical particles (spherules) of nuclear fuel,
particularly for very high temperature reactors (VHTR) and even for
implementing the process called SPHEREPAC. In these different
cases, the main characteristics are the sphericity of the particles to be
manufactured and the control over their grain size. Nonetheless,
depending on the specifications defined for these spherical particles,
the GSP process has intrinsic limits, particularly when fabricating
very small particles. This paper describes the use of secondary
fragmentation (water, water/PVA and uranyl nitrate) on solid
surfaces under varying temperature and vibration conditions to assess
the relevance of using this new technique to manufacture very small
spherical particles by means of a modified GSP process. The
fragmentation mechanisms are monitored and analysed, before the
trends for its subsequent optimised application are described.
Abstract: There are two major variants of the Simplex
Algorithm: the revised method and the standard, or tableau method.
Today, all serious implementations are based on the revised method
because it is more efficient for sparse linear programming problems.
Moreover, there are a number of applications that lead to dense linear
problems so our aim in this paper is to present some computational
results on parallel implementation of dense Simplex Method. Our
implementation is implemented on a SMP cluster using C
programming language and the Message Passing Interface MPI.
Preliminary computational results on randomly generated dense
linear programs support our results.
Abstract: The experimental thermal performance of two heat
exchangers in closed-wet cooling tower (CWCT) was investigated in
this study. The test sections are heat exchangers which have multi path
that is used as the entrance of cooling water and are consisting of
bare-type copper tubes between 15.88mm and 19.05mm. The process
fluids are the cooling water that flows from top part of heat exchanger
to bottom side in the inner side of tube, and spray water that flows
gravitational direction in the outer side of it. Air contacts its outer side
of that as it counterflows. Heat and mass transfer coefficients and
cooling capacity were calculated with variations of process fluids,
multi path and different diameter tubes to figure out the performance
of characteristics of CWCT.
The main results were summarized as follows: The results show this
experiment is reliable with values of heat and mass transfer
coefficients comparing to values of correlations. Heat and mass
transfer coefficients and cooling capacity of two paths are higher than
these with one path using 15.88 and 19.05mm tubes. Cooling capacity
per unit volume with 15.88mm tube using one and two paths are
higher than 19.05mm tube due to increase of surface area per unit
volume.
Abstract: Traditional principal components analysis (PCA)
techniques for face recognition are based on batch-mode training
using a pre-available image set. Real world applications require that
the training set be dynamic of evolving nature where within the
framework of continuous learning, new training images are
continuously added to the original set; this would trigger a costly
continuous re-computation of the eigen space representation via
repeating an entire batch-based training that includes the old and new
images. Incremental PCA methods allow adding new images and
updating the PCA representation. In this paper, two incremental
PCA approaches, CCIPCA and IPCA, are examined and compared.
Besides, different learning and testing strategies are proposed and
applied to the two algorithms. The results suggest that batch PCA is
inferior to both incremental approaches, and that all CCIPCAs are
practically equivalent.
Abstract: The fixed partial dentures are mainly used in the frontal
part of the dental arch because of their great esthetics. There are
several factors that are associated with the stress state created in
ceramic restorations, including: thickness of ceramic layers,
mechanical properties of the materials, elastic modulus of the
supporting substrate material, direction, magnitude and frequency of
applied load, size and location of occlusal contact areas, residual
stresses induced by processing or pores, restoration-cement
interfacial defects and environmental defects. The purpose of this
study is to evaluate the capability of Polarization Sensitive Optical
Coherence Tomography (PSOCT) in detection and analysis of
possible material defects in metal-ceramic and integral ceramic fixed
partial dentures. As a conclusion, it is important to have a non
invasive method to investigate fixed partial prostheses before their
insertion in the oral cavity in order to satisfy the high stress
requirements and the esthetic function.