Abstract: Custom power is a technology driven product and
service solution which embraces a family devices such as Dynamic
Voltage Restorer (DVR), Distributed Shunt Compensator
(DSTATCOM), Solid State Breaker (SSB) etc which will provide
power quality functions at distribution voltages. The rapid response
of these devices enables them to operate in real time, providing
continuous and dynamic control of the supply including voltage and
reactive power regulation, harmonic reduction and elimination of
voltage dips. This paper presents the benefits of multilevel inverters
when they are used for DPC based custom power devices. Power
flow control mechanism, salient features, advantages and
disadvantages of direct power control (DPC) using lookup table,
SVM, predictive voltage vector and hybrid DPC strategies are
discussed in this paper. Simulation results of three level inverter
based STATCOM, harmonic analysis of multi level inverters are
presented at the end.
Abstract: The link between urban planning and design principles and the built environment of an urban renewal area is of interest to the field of urban studies. During the past decade, there has also been increasing interest in urban planning and design; this interest is motivated by the possibility that design policies associated with the built environment can be used to control, manage, and shape individual activity and behavior. However, direct assessments and design techniques of the links between how urban planning design policies influence individuals are still rare in the field. Recent research efforts in urban design have focused on the idea that land use and design policies can be used to increase the quality of design projects for an urban renewal area-s built environment. The development of appropriate design techniques for the built environment is an essential element of this research. Quality function deployment (QFD) is a powerful tool for improving alternative urban design and quality for urban renewal areas, and for procuring a citizen-driven quality system. In this research, we propose an integrated framework based on QFD and an Analytic Network Process (ANP) approach to determine the Alternative Technical Requirements (ATRs) to be considered in designing an urban renewal planning and design alternative. We also identify the research designs and methodologies that can be used to evaluate the performance of urban built environment projects. An application in an urban renewal built environment planning and design project evaluation is presented to illustrate the proposed framework.
Abstract: We report here structural, mechanical and I-V
characteristics of Zn1-xMxO ceramic samples with various x and M.
It is found that the considered dopants does not influence the wellknown
peaks related to wurtzite structure of ZnO ceramics, while the
shape and size of grains are clearly affected. Average crystalline
diameters, deduced from XRD are between 42 nm and 54 nm, which
are 70 times lower than those obtained from SEM micrographs.
Interestingly, the potential barrier could be formed by adding Cu up
to 0.20, and it is completely deformed by 0.025 Ni additions. The
breakdown field could be enhanced up to 4138 V/cm by 0.025 Cu
additions, followed by a decrease with further increase of Cu . On
the other hand a gradual decrease in VHN is reported for both
dopants and their values are higher in Ni samples as compared to Cu
samples. The electrical conductivity is generally improved by Ni,
while addition of Cu improved it only in the over doped region (≥
0.10). These results are discussed in terms of the difference of
valency and ferromagnetic ordering for both dopants as compared to
undoped sample.
Abstract: Pepper spray use has gained momentum since 1992
and although the active ingredient is readily available, it is considered
a weapon with restricted use in many regions, including The
Bahamas. In light of controversy in the literature regarding the
severity of presenting respiration complaints among individuals postacute
exposure of pepper spray inhalation, this descriptive case series
study was conducted to assess the respiratory status of persons
evaluated during a mass casualty in The Bahamas. Parameters noted
were patients- demographics and respiration severity determined via
clinical examination findings, disposition and follow-up review of the
20 persons. Their most common complaint was difficulty breathing
post exposure. Two required admission and stayed for
Abstract: This paper discusses the effectiveness of the EEG signal
for human identification using four or less of channels of two different
types of EEG recordings. Studies have shown that the EEG signal
has biometric potential because signal varies from person to person
and impossible to replicate and steal. Data were collected from 10
male subjects while resting with eyes open and eyes closed in 5
separate sessions conducted over a course of two weeks. Features
were extracted using the wavelet packet decomposition and analyzed
to obtain the feature vectors. Subsequently, the neural networks
algorithm was used to classify the feature vectors. Results show that,
whether or not the subjects- eyes were open are insignificant for a 4–
channel biometrics system with a classification rate of 81%. However,
for a 2–channel system, the P4 channel should not be included if data
is acquired with the subjects- eyes open. It was observed that for 2–
channel system using only the C3 and C4 channels, a classification
rate of 71% was achieved.
Abstract: This paper describes dynamic analysis using proposed
fast finite element method for a shock absorbing structure including a
sponge. The structure is supported by nonlinear concentrated springs.
The restoring force of the spring has cubic nonlinearity and linear
hysteresis damping. To calculate damping properties for the structures
including elastic body and porous body, displacement vectors as
common unknown variable are solved under coupled condition. Under
small amplitude, we apply asymptotic method to complex eigenvalue
problem of this system to obtain modal parameters. And then
expressions of modal loss factor are derived approximately. This
approach was proposed by one of the authors previously. We call this
method as Modal Strain and Kinetic Energy Method (MSKE method).
Further, using the modal loss factors, the discretized equations in
physical coordinate are transformed into the nonlinear ordinary
coupled equations using normal coordinate corresponding to linear
natural modes. This transformation yields computation efficiency. As
a numerical example of a shock absorbing structures, we adopt double
skins with a sponge. The double skins are supported by nonlinear
concentrated springs. We clarify influences of amplitude of the input
force on nonlinear and chaotic responses.
Abstract: The usual method of river flow diversion involves construction of tunnels and cofferdams. Given the fact that the cost of diversion works could be as high as 10-20% of the total dam construction cost, due attention should be paid to optimum design of the diversion works. The cost of diversion works depends, on factors, such as: the tunnel dimensions and the intended tunneling support measures during and after excavation; quality and characterizes of the rock through which the tunnel should be excavated; the dimensions of the upstream (and downstream) cofferdams; and the magnitude of river flood the system is designed to divert. In this paper by use of the cost of unit prices for tunnel excavation, tunnel lining, tunnel support (rock bolt + shotcrete) and cofferdam fill the cost function was determined. The function is then minimized by the aid of PSO Algorithm (particle swarm optimization). It is found that the optimum diameter and the total diversion cost are directly related to the river flood discharge (Q). It has also shown that in addition to optimum diameter design discharge (Q), river length, tunnel length, is mainly a function of the ratios (not the absolute values) of the unit prices and does not depend on the overall price levels in the respective country. The results of optimization use in some of the case study lead us to significant changes in the cost.
Abstract: In recent times there has been a growing interest in the
development of quasi-two-dimensional niobium pentoxide (Nb2O5)
as a semiconductor for the potential electronic applications such as
capacitors, filtration, dye-sensitised solar cells and gas sensing
platforms. Therefore once the purpose is established, Nb2O5 can be
prepared in a number of nano- and sub-micron-structural
morphologies that include rods, wires, belts and tubes. In this study
films of Nb2O5 were prepared on gold plated silicon substrate using
spin-coating technique and subsequently by mechanical exfoliation.
The reason this method was employed was to achieve layers of less
than 15nm in thickness. The sintering temperature of the specimen
was 800oC. The morphology and structural characteristics of the
films were analyzed by Atomic Force Microscopy (AFM), Raman
Spectroscopy, X-ray Photoelectron Spectroscopy (XPS).
Abstract: In this paper; we are interested in dynamic modelling of quadrotor while taking into account the high-order nonholonomic constraints as well as the various physical phenomena, which can influence the dynamics of a flying structure. These permit us to introduce a new state-space representation and new control scheme. We present after the development and the synthesis of a stabilizing control laws design based on sliding mode in order to perform best tracking results. It ensures locally asymptotic stability and desired tracking trajectories. Nonlinear observer is then synthesized in order to estimate the unmeasured states and the effects of the external disturbances such as wind and noise. Finally simulation results are also provided in order to illustrate the performances of the proposed controllers.
Abstract: Information of nodes’ locations is an important
criterion for lots of applications in Wireless Sensor Networks. In the
hop-based range-free localization methods, anchors transmit the
localization messages counting a hop count value to the whole
network. Each node receives this message and calculates its own
distance with anchor in hops and then approximates its own position.
However the estimative distances can provoke large error, and affect
the localization precision. To solve the problem, this paper proposes
an algorithm, which makes the unknown nodes fix the nearest anchor
as a reference and select two other anchors which are the most
accurate to achieve the estimated location. Compared to the DV-Hop
algorithm, experiment results illustrate that proposed algorithm has
less average localization error and is more effective.
Abstract: In this paper the authors propose a flexible electronic solution, to improve the energetic efficiency of a thermo plant. This is achieved by replacing the mechanical gear box, placed traditionally between a gas turbine and a synchronous generator; by a power electronic converter. After reminding problematic of gear boxes and interest of a proposed electronic solution in high power plants, the authors describe a new control strategy for an indirect frequency converter, which is characterized by its high efficiency due to the use of SWM: Square Wave Modulation. The main advantage of this mode is the quasi absence of switching losses. A control method is also proposed to resolve some problems incurred by using square wave modulation, in particular to reduce the harmonics distortion of the output inverter voltage and current. Simulation examples as well as experimental results are included.
Abstract: The vast amount of information hidden in huge
databases has created tremendous interests in the field of data
mining. This paper examines the possibility of using data clustering
techniques in oral medicine to identify functional relationships
between different attributes and classification of similar patient
examinations. Commonly used data clustering algorithms have been
reviewed and as a result several interesting results have been
gathered.
Abstract: The Baltic States regained independence and started
the pathway from command economy to market economy and
entered European Union at the same time. Latter internationally
recognized evaluations for the countries are diverse. The present
diversity of the Baltic States -Economic Development is a subject of
interest because of the similarities – all three are small, open
economies, countries have similar geographic location and initially
likewise historical and political backgrounds. This article explains
relationship between social environment, business environment and
economic growth. It argues that the elements of social environment
underlie more successful economic development. It researches the
causes, why Estonia has performed better in economic outcomes and
development. The article analyses selection of socio-economic
indicators of all three Baltic States – Latvia, Lithuania and Estonia
for the time period of ten years to include the influence of economic
cycles.
Abstract: Culinary culture differences can cause health
problems for international tourists in Thailand. This paper drew upon
data collected from an international tourist survey conducted in
Bangkok, Thailand during summer of 2012. Summer is the period
that a variety food safety issues and incidents are often publicized in
Thailand. The survey targeted European Union tourists- concerns
toward a variety of food safety issues that they encountered during
their trip in Thailand. A total of 400 respondents were elicited as data
input for t-test, and one way ANOVA test. The findings revealed an
astonishing result that up to 46.5 percent of respondents were sick at
least one time or more in Thailand. However, the majority of
respondents trusted that the Thai hotel and Thai restaurants would
ensure food safety, but they did not trust street vendors to ensure food
safety. The level of food safety concern can be ranked from most
concern to least concern by using the value of mean scores as
follows: 1) artificial coloring, 2) use of preservatives, 3) antibiotics,
4) growth hormones, 5) chemical residues, and 6) bacterial
contamination. The overall mean score for level of concerns was
3.493 with standard deviation of 1.677 which did not indicate a very
high level of concern. In addition, the result for t-test and one way
ANOVA test revealed that there was not much effect from the
demographic differences to level of food safety concerns.
Abstract: Distributed Power generation has gained a lot of
attention in recent times due to constraints associated with
conventional power generation and new advancements in DG
technologies .The need to operate the power system economically
and with optimum levels of reliability has further led to an increase
in interest in Distributed Generation. However it is important to place
Distributed Generator on an optimum location so that the purpose of
loss minimization and voltage regulation is dully served on the
feeder. This paper investigates the impact of DG units installation on
electric losses, reliability and voltage profile of distribution networks.
In this paper, our aim would be to find optimal distributed
generation allocation for loss reduction subjected to constraint of
voltage regulation in distribution network. The system is further
analyzed for increased levels of Reliability. Distributed Generator
offers the additional advantage of increase in reliability levels as
suggested by the improvements in various reliability indices such as
SAIDI, CAIDI and AENS. Comparative studies are performed and
related results are addressed. An analytical technique is used in order
to find the optimal location of Distributed Generator. The suggested
technique is programmed under MATLAB software. The results
clearly indicate that DG can reduce the electrical line loss while
simultaneously improving the reliability of the system.
Abstract: Today modern simulations solutions in the wind turbine industry have achieved a high degree of complexity and detail in result. Limitations exist when it is time to validate model results against measurements. Regarding Model validation it is of special interest to identify mode frequencies and to differentiate them from the different excitations. A wind turbine is a complex device and measurements regarding any part of the assembly show a lot of noise. Input excitations are difficult or even impossible to measure due to the stochastic nature of the environment. Traditional techniques for frequency analysis or features extraction are widely used to analyze wind turbine sensor signals, but have several limitations specially attending to non stationary signals (Events). A new technique based on autoregresive analysis techniques is introduced here for a specific application, a comparison and examples related to different events in the wind turbine operations are presented.
Abstract: This paper describes a prototype aircraft that can fly
slowly, safely and transmit wireless video for tasks like reconnaissance,
surveillance and target acquisition. The aircraft is designed to
fly in closed quarters like forests, buildings, caves and tunnels which
are often spacious but GPS reception is poor. Envisioned is that a
small, safe and slow flying vehicle can assist in performing dull,
dangerous and dirty tasks like disaster mitigation, search-and-rescue
and structural damage assessment.
Abstract: Bioinformatics and computational biology involve
the use of techniques including applied mathematics,
informatics, statistics, computer science, artificial intelligence,
chemistry, and biochemistry to solve biological problems
usually on the molecular level. Research in computational
biology often overlaps with systems biology. Major research
efforts in the field include sequence alignment, gene finding,
genome assembly, protein structure alignment, protein structure
prediction, prediction of gene expression and proteinprotein
interactions, and the modeling of evolution. Various
global rearrangements of permutations, such as reversals and
transpositions,have recently become of interest because of their
applications in computational molecular biology. A reversal is
an operation that reverses the order of a substring of a permutation.
A transposition is an operation that swaps two adjacent
substrings of a permutation. The problem of determining the
smallest number of reversals required to transform a given
permutation into the identity permutation is called sorting by
reversals. Similar problems can be defined for transpositions
and other global rearrangements. In this work we perform a
study about some genome rearrangement primitives. We show
how a genome is modelled by a permutation, introduce some
of the existing primitives and the lower and upper bounds
on them. We then provide a comparison of the introduced
primitives.
Abstract: In this study, the contact problem of a layered composite which consists of two materials with different elastic constants and heights resting on two rigid flat supports with sharp edges is considered. The effect of gravity is neglected. While friction between the layers is taken into account, it is assumed that there is no friction between the supports and the layered composite so that only compressive tractions can be transmitted across the interface. The layered composite is subjected to a uniform clamping pressure over a finite portion of its top surface. The problem is reduced to a singular integral equation in which the contact pressure is the unknown function. The singular integral equation is evaluated numerically and the results for various dimensionless quantities are presented in graphical forms.
Abstract: In a bi-fuel diesel engine, the carburetor plays a vital
role in switching from fuel gas to petrol mode operation and viceversa.
The carburetor is the most important part of the fuel system of
a diesel engine. All diesel engines carry variable venturi mixer
carburetors. The basic operation of the carburetor mainly depends on
the restriction barrel called the venturi. When air flows through the
venturi, its speed increases and its pressure decreases. The main
challenge focuses on designing a mixing device which mixes the
supplied gas is the incoming air at an optimum ratio. In order to
surmount the identified problems, the way fuel gas and air flow in
the mixer have to be analyzed. In this case, the Computational Fluid
Dynamics or CFD approach is applied in design of the prototype
mixer. The present work is aimed at further understanding of the air
and fuel flow structure by performing CFD studies using a software
code. In this study for mixing air and gas in the condition that has
been mentioned in continuance, some mixers have been designed.
Then using of computational fluid dynamics, the optimum mixer has
been selected. The results indicated that mixer with 12 holes can
produce a homogenous mixture than those of 8-holes and 6-holes
mixer. Also the result showed that if inlet convergency was smoother
than outlet divergency, the mixture get more homogenous, the reason
of that is in increasing turbulence in outlet divergency.