Abstract: The accuracy of estimated stability and control
derivatives of a light aircraft from flight test data were evaluated. The light aircraft, named ChangGong-91, is the first certified aircraft from
the Korean government. The output error method, which is a maximum likelihood estimation technique and considers measurement
noise only, was used to analyze the aircraft responses measures. The
multi-step control inputs were applied in order to excite the short period mode for the longitudinal and Dutch-roll mode for the lateral-directional motion. The estimated stability/control derivatives of Chan Gong-91 were analyzed for the assessment of handling
qualities comparing them with those of similar aircraft. The accuracy of the flight derivative estimates derived from flight test measurement
was examined in engineering judgment, scatter and Cramer-Rao bound, which turned out to be satisfactory with minor defects..
Abstract: In hypersonic environments, the aerothermal effect
makes it difficult for the optical side windows of optical guided
missiles to withstand high heat. This produces cracking or breaking,
resulting in an inability to function. This study used computational
fluid mechanics to investigate the external cooling jet conditions of
optical side windows. The turbulent models k-ε and k-ω were
simulated. To be in better accord with actual aerothermal
environments, a thermal radiation model was added to examine
suitable amounts of external coolants and the optical window
problems of aero-thermodynamics. The simulation results indicate that
when there are no external cooling jets, because airflow on the optical
window and the tail groove produce vortices, the temperatures in these
two locations reach a peak of approximately 1600 K. When the
external cooling jets worked at 0.15 kg/s, the surface temperature of
the optical windows dropped to approximately 280 K. When adding
thermal radiation conditions, because heat flux dissipation was faster,
the surface temperature of the optical windows fell from 280 K to
approximately 260 K. The difference in influence of the different
turbulence models k-ε and k-ω on optical window surface temperature
was not significant.
Abstract: Expression and secretion of inflammation markers are
disturbed in obesity. Interleukin-6 reduces body fat mass. The
common G-174C polymorphism in the promoter of IL-6 gene has
been reported that effects on transcriptional regulation. The objective
was to investigate association of the common polymorphism G-174C
with obesity in Iranian population. The present study is cross
sectional association study that included 242 individuals (110 men
and 132 women). Serum IL-6 levels, C-reactive protein, fasting
blood glucose and blood lipids profile were measured .BMI and
WHR were calculated. Genotyping is carried out by PCR and RFLP.
The frequencies of G and C allele were 64.5% and 35.5%,
respectively. The G-174C polymorphism was not associated with
BMI and WHR. However in obese individual, fasting blood glucose
was significantly higher in carrier of C allele compared with the noncarrier.
The IL-6 G-174C polymorphism is not a risk factor for
obesity in Iranian population.
Abstract: As a structure for processing string problem, suffix
array is certainly widely-known and extensively-studied. But if the
string access pattern follows the “90/10" rule, suffix array can not take
advantage of the fact that we often find something that we have just
found. Although the splay tree is an efficient data structure for small
documents when the access pattern follows the “90/10" rule, it
requires many structures and an excessive amount of pointer
manipulations for efficiently processing and searching large
documents. In this paper, we propose a new and conceptually powerful
data structure, called splay suffix arrays (SSA), for string search. This
data structure combines the features of splay tree and suffix arrays into
a new approach which is suitable to implementation on both
conventional and clustered computers.
Abstract: The objective of this work which is based on the
approach of simultaneous engineering is to contribute to the
development of a CIM tool for the synthesis of functional design
dimensions expressed by average values and tolerance intervals. In
this paper, the dispersions method known as the Δl method which
proved reliable in the simulation of manufacturing dimensions is
used to develop a methodology for the automation of the simulation.
This methodology is constructed around three procedures. The first
procedure executes the verification of the functional requirements by
automatically extracting the functional dimension chains in the
mechanical sub-assembly. Then a second procedure performs an
optimization of the dispersions on the basis of unknown variables.
The third procedure uses the optimized values of the dispersions to
compute the optimized average values and tolerances of the
functional dimensions in the chains. A statistical and cost based
approach is integrated in the methodology in order to take account of
the capabilities of the manufacturing processes and to distribute
optimal values among the individual components of the chains.
Abstract: A fast and efficient model of application development called user interface oriented application development (UIOAD) is proposed. This approach introduces a convenient way for users to develop a platform independent client-server application.
Abstract: The increasing popularity of wireless technologies
and mobile computing devices has enabled new application areas and
research. One of these new areas is pervasive systems in urban
environments, because urban environments are characterized by high
concentration of these technologies and devices. In this paper we will
show the process of pervasive system design in urban environments,
using as use case a local zoo in Cali, Colombia. Based on an
ethnographic studio, we present the design of a pervasive system for
urban computing based on service oriented architecture to controlled
environment of Cali Zoo. In this paper, the reader will find a
methodological approach for the design of similar systems, using
data collection methods, conceptual frameworks for urban
environments and considerations of analysis and design of service
oriented systems.
Abstract: A new blind gray-level watermarking scheme is described. In the proposed method, the host image is first divided into 4*4 non-overlapping blocks. For each block, two first AC coefficients of its Hadamard transform are then estimated using DC coefficients of its neighbor blocks. A gray-level watermark is then added into estimated values. Since embedding watermark does not change the DC coefficients, watermark extracting could be done by estimating AC coefficients and comparing them with their actual values. Several experiments are made and results suggest the robustness of the proposed algorithm.
Abstract: This paper puts forward one kind of air-fuel ratio
control method with PI controller. With the help of
MATLAB/SIMULINK software, the mathematical model of air-fuel
ratio control system for distributorless CNG engine is constructed.
The objective is to maintain cylinder-to-cylinder air-fuel ratio at a
prescribed set point, determined primarily by the state of the Three-
Way-Catalyst (TWC), so that the pollutants in the exhaust are
removed with the highest efficiency. The concurrent control of airfuel
under transient conditions could be implemented by Proportional
and Integral (PI) controller. The simulation result indicates that the
control methods can easily eliminate the air/fuel maldistribution and
maintain the air/fuel ratio at the stochiometry within minimum
engine events.
Abstract: The mobile users with Laptops need to have an
efficient access to i.e. their home personal data or to the Internet from
any place in the world, regardless of their location or point of
attachment, especially while roaming outside the home subnet. An
efficient interpretation of packet losses problem that is encountered
from this roaming is to the centric of all aspects in this work, to be
over-highlighted. The main previous works, such as BER-systems,
Amigos, and ns-2 implementation that are considered to be in
conjunction with that problem under study are reviewed and
discussed. Their drawbacks and limitations, of stopping only at
monitoring, and not to provide an actual solution for eliminating or
even restricting these losses, are mentioned. Besides that, the
framework around which we built a Triple-R sequence as a costeffective
solution to eliminate the packet losses and bridge the gap
between subnets, an area that until now has been largely neglected, is
presented. The results show that, in addition to the high bit error rate
of wireless mobile networks, mainly the low efficiency of mobile-IP
registration procedure is a direct cause of these packet losses.
Furthermore, the output of packet losses interpretation resulted an
illustrated triangle of the registration process. This triangle should be
further researched and analyzed in our future work.
Abstract: The effect of the blade tip geometry of a high pressure
gas turbine is studied experimentally and computationally for high
speed leakage flows. For this purpose two simplified models are
constructed, one models a flat tip of the blade and the second models
a cavity tip of the blade. Experimental results are obtained from a
transonic wind tunnel to show the static pressure distribution along
the tip wall and provide flow visualization. RANS computations
were carried to provide further insight into the mean flow behavior
and to calculate the discharge coefficient which is a measure of the
flow leaking over the tip. It is shown that in both geometries of tip
the flow separates over the tip to form a separation bubble. The
bubble is higher for the cavity tip while a complete shock wave
system of oblique waves ending with a normal wave can be seen for
the flat tip. The discharge coefficient for the flat tip shows less
dependence on the pressure ratio over the blade tip than the cavity
tip. However, the discharge coefficient for the cavity tip is lower than
that of the flat tip, showing a better ability to reduce the leakage flow
and thus increase the turbine efficiency.
Abstract: This paper presents an adaptive feedback linearization approach to derive helicopter. Ideal feedback linearization is defined for the cases when the system model is known. Adaptive feedback linearization is employed to get asymptotically exact cancellation for the inherent uncertainty in the knowledge of the given parameters of system. The control algorithm is implemented using the feedback linearization technique and adaptive method. The controller parameters are unknown where an adaptive control law aims to drive them towards their ideal values for providing perfect model matching between the reference model and the closed-loop plant model. The converged parameters of controller would then provide good estimates for the unknown plant parameters.
Abstract: Atmospheric stability plays the most important role in
the transport and dispersion of air pollutants. Different methods are
used for stability determination with varying degrees of complexity.
Most of these methods are based on the relative magnitude of
convective and mechanical turbulence in atmospheric motions.
Richardson number, Monin-Obukhov length, Pasquill-Gifford
stability classification and Pasquill–Turner stability classification, are
the most common parameters and methods. The Pasquill–Turner
Method (PTM), which is employed in this study, makes use of
observations of wind speed, insolation and the time of day to classify
atmospheric stability with distinguishable indices. In this study, a
model is presented to determination of atmospheric stability
conditions using PTM. As a case study, meteorological data of
Mehrabad station in Tehran from 2000 to 2005 is applied to model.
Here, three different categories are considered to deduce the pattern
of stability conditions. First, the total pattern of stability classification
is obtained and results show that atmosphere is 38.77%, 27.26%,
33.97%, at stable, neutral and unstable condition, respectively. It is
also observed that days are mostly unstable (66.50%) while nights are
mostly stable (72.55%). Second, monthly and seasonal patterns are
derived and results indicate that relative frequency of stable
conditions decrease during January to June and increase during June
to December, while results for unstable conditions are exactly in
opposite manner. Autumn is the most stable season with relative
frequency of 50.69% for stable condition, whilst, it is 42.79%,
34.38% and 27.08% for winter, summer and spring, respectively.
Hourly stability pattern is the third category that points out that
unstable condition is dominant from approximately 03-15 GTM and
04-12 GTM for warm and cold seasons, respectively. Finally,
correlation between atmospheric stability and CO concentration is
achieved.
Abstract: This experiment discusses the effects of fracture
parameters such as depth, length, width, angle and the number of the
fracture to the conductance properties of laterite using the DUK-2B
digital electrical measurement system combined with the method of
simulating the fractures. The results of experiment show that the
changes of fracture parameters produce effects to the conductance
properties of laterite. There is a clear degressive period of the
conductivity of laterite during increasing the depth, length, width, or
the angle and the quantity of fracture gradually. When the depth of
fracture exceeds the half thickness of the soil body, the conductivity of
laterite shows evidently non-linear diminishing pattern and the
amplitude of decrease tends to increase. The length of fracture has
fewer effects than the depth to the conductivity. When the width of
fracture reaches some fixed values, the change of the conductivity is
less sensitive to the change of the width, and at this time, the
conductivity of laterite maintains at a stable level. When the angle of
fracture is less than 45°, the decrease of the conductivity is more
clearly as the angle increases. But when angle is more than 45°,
change of the conductivity is relatively gentle as the angle increases.
The increasing quantity of the fracture causes the other fracture
parameters having great impact on the change of conductivity. When
moisture content and temperature were unchanged, depth and angle of
fractures are the major factors affecting the conductivity of laterite
soil; quantity, length, and width are minor influencing factors. The
sensitivity of fracture parameters affect conductivity of laterite soil is:
depth >angles >quantity >length >width.
Abstract: Optical character recognition of cursive scripts
presents a number of challenging problems in both segmentation and
recognition processes in different languages, including Persian. In
order to overcome these problems, we use a newly developed Persian
word segmentation method and a recognition-based segmentation
technique to overcome its segmentation problems. This method is
robust as well as flexible. It also increases the system-s tolerances to
font variations. The implementation results of this method on a
comprehensive database show a high degree of accuracy which meets
the requirements for commercial use. Extended with a suitable pre
and post-processing, the method offers a simple and fast framework
to develop a full OCR system.
Abstract: In this paper we present a photo mosaic smartphone
application in client-server based large-scale image databases. Photo
mosaic is not a new concept, but there are very few smartphone
applications especially for a huge number of images in the
client-server environment. To support large-scale image databases,
we first propose an overall framework working as a client-server
model. We then present a concept of image-PAA features to efficiently
handle a huge number of images and discuss its lower bounding
property. We also present a best-match algorithm that exploits the
lower bounding property of image-PAA. We finally implement an
efficient Android-based application and demonstrate its feasibility.
Abstract: Tourism industries are rapidly increased for the last
few years especially in Malaysia. In order to attract more tourists,
Malaysian Governance encourages any effort to increase Malaysian
tourism industry. One of the efforts in attracting more tourists in
Malacca, Malaysia is a duck tour. Duck tour is an amphibious
sightseeing tour that works in two types of engines, hence, it required
a huge cost to operate and maintain the vehicle. To other country, it is
not so new but in Malaysia, it is just introduced, thus it does not have
any systematic routing yet. Therefore, this paper proposed an
optimization technique to formulate and schedule this tour to
minimize the operating costs by considering it into Travelling
Salesman Problem (TSP). The problem is then can be solved by one
of the optimization technique especially meta-heuristics approach
such as Tabu Search (TS) and Reactive Tabu Search (RTS).
Abstract: The present study investigated the relationship
between personality characteristics of drivers and the number and
amount of fines they have in a year .This study was carried out on
120 male taxi drivers that worked at least seven hours in a day in
Lamerd - a city in the south of IRAN. Subjects were chosen
voluntarily among those available. Predictive variables were the NEO
–five great personality factors (1. conscientiousness 2. Openness to
Experience 3.Neuroticism4 .Extraversion 5.Agreeableness )
thecriterion variables were the number and amount of fines the
drivers have had the last three years. the result of regression analysis
showed that conscientiousness factor was able to negatively predict
the number and amount of financial fines the drivers had during the
last three years. The openness factor positively predicted the number
of fines they had in last 3 years and the amount of financial fines
during the last year. The extraversion factor both meaningfully and
positively could predict only the amount of financial fines they had
during the last year. Increasing age was associated with decreasing
driving offenses as well as financial loss.The findings can be useful
in recognizing the high-risk drivers and leading them to counseling
centers .They can also be used to inform the drivers about their
personality and it’s relation with their accident rate. Such criteria
would be of great importance in employing drivers in different places
such as companies, offices etc…
Abstract: This paper presents anapproach of hybridizing two or more artificial intelligence (AI) techniques which arebeing used to
fuzzify the workstress level ranking and categorize the rating accordingly. The use of two or more techniques (hybrid approach)
has been considered in this case, as combining different techniques may lead to neutralizing each other-s weaknesses generating a
superior hybrid solution. Recent researches have shown that there is a
need for a more valid and reliable tools, for assessing work stress. Thus artificial intelligence techniques have been applied in this
instance to provide a solution to a psychological application. An overview about the novel and autonomous interactive model for analysing work-stress that has been developedusing multi-agent
systems is also presented in this paper. The establishment of the intelligent multi-agent decision analyser (IMADA) using hybridized technique of neural networks and fuzzy logic within the multi-agent based framework is also described.
Abstract: Selecting the data modeling technique for an
information system is determined by the objective of the resultant
data model. Dimensional modeling is the preferred modeling
technique for data destined for data warehouses and data mining,
presenting data models that ease analysis and queries which are in
contrast with entity relationship modeling. The establishment of data
warehouses as components of information system landscapes in
many organizations has subsequently led to the development of
dimensional modeling. This has been significantly more developed
and reported for the commercial database management systems as
compared to the open sources thereby making it less affordable for
those in resource constrained settings. This paper presents
dimensional modeling of HIV patient information using open source
modeling tools. It aims to take advantage of the fact that the most
affected regions by the HIV virus are also heavily resource
constrained (sub-Saharan Africa) whereas having large quantities of
HIV data. Two HIV data source systems were studied to identify
appropriate dimensions and facts these were then modeled using two
open source dimensional modeling tools. Use of open source would
reduce the software costs for dimensional modeling and in turn make
data warehousing and data mining more feasible even for those in
resource constrained settings but with data available.