Abstract: This paper studies the problem of exponential
stability of perturbed discrete linear systems with periodic
coefficients. Assuming that the unperturbed system is exponentially
stable we obtain conditions on the perturbations under which the
perturbed system is exponentially stable.
Abstract: This study attempts to validate the consumer-oriented
criteria list, developed by Wang et al. (2010), for selecting online
travel shopping sites. Based on a sample of 985 respondents,
confirmatory factor analysis was employed to test the factor structure
and assess the reliability and validity of the list. The results support the
list developed by Wang et al. (2010) and claim the list can be further
used to analyze, explain, and understand consumer behaviors about
online travel shopping.
Abstract: Skin color can provide a useful and robust cue
for human-related image analysis, such as face detection,
pornographic image filtering, hand detection and tracking,
people retrieval in databases and Internet, etc. The major
problem of such kinds of skin color detection algorithms is
that it is time consuming and hence cannot be applied to a real
time system. To overcome this problem, we introduce a new
fast technique for skin detection which can be applied in a real
time system. In this technique, instead of testing each image
pixel to label it as skin or non-skin (as in classic techniques),
we skip a set of pixels. The reason of the skipping process is
the high probability that neighbors of the skin color pixels are
also skin pixels, especially in adult images and vise versa. The
proposed method can rapidly detect skin and non-skin color
pixels, which in turn dramatically reduce the CPU time
required for the protection process. Since many fast detection
techniques are based on image resizing, we apply our
proposed pixel skipping technique with image resizing to
obtain better results. The performance evaluation of the
proposed skipping and hybrid techniques in terms of the
measured CPU time is presented. Experimental results
demonstrate that the proposed methods achieve better result
than the relevant classic method.
Abstract: Synchronization between 0.1 Hz oscillations in heart rate and blood pressure is studied and its change during vertical tilt is evaluated in 37 myocardial infarction patients. Two groups of patients are identified with decreased and increased, respectively, synchronization of the studied oscillations as a response to a tilt test. It is shown that assessment of synchronization of 0.1 Hz oscillations as a response to vertical tilt can be used as a guideline for selecting optimal dose of beta-blocker treatment in post-myocardial infarction patients.
Abstract: The very nonlinear nature of the generator and system
behaviour following a severe disturbance precludes the use of
classical linear control technique. In this paper, a new approach of
nonlinear control is proposed for transient and steady state stability
analysis of a synchronous generator. The control law of the generator
excitation is derived from the basis of Lyapunov stability criterion.
The overall stability of the system is shown using Lyapunov
technique. The application of the proposed controller to simulated
generator excitation control under a large sudden fault and wide
range of operating conditions demonstrates that the new control
strategy is superior to conventional automatic voltage regulator
(AVR), and show very promising results.
Abstract: This paper treats a discrete-time finite buffer batch arrival queue with a single working vacation and partial batch rejection in which the inter-arrival and service times are, respectively, arbitrary and geometrically distributed. The queue is analyzed by using the supplementary variable and the imbedded Markov-chain techniques. We obtain steady-state system length distributions at prearrival, arbitrary and outside observer-s observation epochs. We also present probability generation function (p.g.f.) of actual waiting-time distribution in the system and some performance measures.
Abstract: Depressurization and pressurization streams in
industrial systems constitute a work exchange network (WEN). In this
paper, a novel graphical approach for targeting energy conservation
potential of a WEN is proposed. Through constructing the composite
work curves in the pressure-work diagram and assuming all of the
mechanical energy of the depressurization streams is recovered by
expanders, the maximum work target of a WEN can be determined via
the proposed targeting steps. A WEN in an ammonia production
process is used as a case study to illustrate the applicability of the
proposed graphical approach.
Abstract: The objective of this paper is to present a
comparative study of Homotopy Perturbation Method (HPM),
Variational Iteration Method (VIM) and Homotopy Analysis
Method (HAM) for the semi analytical solution of Kortweg-de
Vries (KdV) type equation called KdV. The study have been
highlighted the efficiency and capability of aforementioned methods
in solving these nonlinear problems which has been arisen from a
number of important physical phenomenon.
Abstract: Banyan networks are really attractive for serving as
the optical switching architectures due to their unique properties of
small depth and absolute signal loss uniformity. The fact has been
established that the limitations of blocking nature and the nonavailability
of proper connections due to non-rearrangeable property
can be easily ruled out using electro-optic MZI switches as basic
switching elements. Combination of the horizontal expansion and
vertical stacking of optical banyan networks is an appropriate scheme
for constructing non-blocking banyan-based optical switching
networks. The interconnected banyan switching fabrics (IBSF) have
been considered and analyzed to best serve the purpose of optical
switching with electro-optic MZI basic elements. The cross/bar state
interchange for the switches has been facilitated by appropriate
voltage switching or the by the switching of operating wavelength.
The paper is dedicated to the modification of the basic switching
element being used as well as the architecture of the switching
network.
Abstract: Visual information is very important in human perception
of surrounding world. Video is one of the most common ways to
capture visual information. The video capability has many benefits
and can be used in various applications. For the most part, the
video information is used to bring entertainment and help to relax,
moreover, it can improve the quality of life of deaf people. Visual
information is crucial for hearing impaired people, it allows them to
communicate personally, using the sign language; some parts of the
person being spoken to, are more important than others (e.g. hands,
face). Therefore, the information about visually relevant parts of the
image, allows us to design objective metric for this specific case. In
this paper, we present an example of an objective metric based on
human visual attention and detection of salient object in the observed
scene.
Abstract: Innovations and innovative activity get the increasing
value for successful financial and economic activity of the countries
and regions. The level of innovative sphere development determines
place of a country or a region in world economy and forms a basis of
steady economic growth. This article is devoted to different aspects
of organization of the national economic safety in the conditions of
innovative development, its problems, risks and threats. Economy
can be considered as aspiring for transition to innovative way only
with finding of economic safety: financial independence, power
stability and technological progress. There are statistical indicators,
defining the level of economic security and factors, threatening
economic safety of the state. The research is based on the analysis of
factors and indicators in conditions of innovative development. The
paper is illustrated by the examples of possible estimated system of
the economic safety level.
Abstract: The aim of this study was to analyse the most
important parameters determining the quality of the motion structure
of the basic classical dance jump – grand jeté.Research sample
consisted of 8 students of the Dance Conservatory in Brno. Using the
system Simi motion we performed a 3D kinematic analysis of the
jump. On the basis of the comparison of structure quality and
measured data of the grand jeté, we defined the optimal values of the
relevant parameters determining the quality of the performance. The
take-off speed should achieve about 2.4 m·s-1, the optimum take-off
angle is 28 - 30º. The take-off leg should swing backward at the
beginning of the flight phase with the minimum speed of 3.3 m·s-1.If
motor abilities of dancers achieve the level necessary for optimal
performance of a classical dance jump, there is room for certain
variability of the structure of the dance jump.
Abstract: Homogeneous composites of alumina and zirconia
with a small amount of MgO (99%) were obtained for ZTA ceramic containing 0.05 wt% MgO in
1500 °C.
Abstract: Use of microemulsion in enhanced oil recovery has become more attractive in recent years because of its high level of extraction efficiency. Experimental investigations have been made on characterization of microemulsions of oil-brinesurfactant/ cosurfactant system for its use in enhanced oil recovery (EOR). Sodium dodecyl sulfate, propan-1-ol and heptane were selected as surfactant, cosurfactant and oil respectively for preparation of microemulsion. The effects of salinity on the relative phase volumes and solubilization parameters have also been studied. As salinity changes from low to high value, phase transition takes place from Winsor I to Winsor II via Winsor III. Suitable microemulsion composition has been selected based on its stability and ability to reduce interfacial tension. A series of flooding experiments have been performed using the selected microemulsion. The flooding experiments were performed in a core flooding apparatus using uniform sand pack. The core holder was tightly packed with uniform sands (60-100 mesh) and saturated with brines of different salinities. It was flooded with the brine at 25 psig and the absolute permeability was calculated from the flow rate of the through sand pack. The sand pack was then flooded with the crude oil at 800 psig to irreducible water saturation. The initial water saturation was determined on the basis of mass balance. Waterflooding was conducted by placing the coreholder horizontally at a constant injection pressure at 200 pisg. After water flooding, when water-cut reached above 95%, around 0.5 pore volume (PV) of the above microemulsion slug was injected followed by chasing water. The experiments were repeated using different composition of microemulsion slug. The additional recoveries were calculated by material balance. Encouraging results with additional recovery more than 20% of original oil in place above the conventional water flooding have been observed.
Abstract: Biodiversity crisis is one of the many crises that
started at the turn of the millennia. Concrete form of expression is
still disputed, but there is a relatively high consensus regarding the
high rate of degradation and the urgent need for action. The strategy
of action outlines a strong economic component, together with the
recognition of market mechanisms as the most effective policies to
protect biodiversity. In this context, biodiversity and ecosystem
services are natural assets that play a key role in economic strategies
and technological development to promote development and
prosperity. Developing and strengthening policies for transition to an
economy based on efficient use of resources is the way forward.
To emphasize the co-viability specific to the connection economyecosystem
services, scientific approach aimed on one hand how to
implement policies for nature conservation and on the other hand, the
concepts underlying the economic expression of ecosystem services-
value, in the context of current technology. Following the analysis of
business opportunities associated with changes in ecosystem services
was concluded that development of market mechanisms for nature
conservation is a trend that is increasingly stronger individualized
within recent years. Although there are still many controversial issues
that have already given rise to an obvious bias, international
organizations and national governments have initiated and
implemented in cooperation or independently such mechanisms.
Consequently, they created the conditions for convergence between
private interests and social interests of nature conservation, so there
are opportunities for ongoing business development which leads,
among other things, the positive effects on biodiversity. Finally,
points out that markets fail to quantify the value of most ecosystem
services. Existing price signals reflect at best, only a proportion of the
total amount corresponding provision of food, water or fuel.
Abstract: Currently, most of distance learning courses can only
deliver standard material to students. Students receive course content
passively which leads to the neglect of the goal of education – “to suit
the teaching to the ability of students". Providing appropriate course
content according to students- ability is the main goal of this paper.
Except offering a series of conventional learning services, abundant
information available, and instant message delivery, a complete online
learning environment should be able to distinguish between students-
ability and provide learning courses that best suit their ability.
However, if a distance learning site contains well-designed course
content and design but fails to provide adaptive courses, students will
gradually loss their interests and confidence in learning and result in
ineffective learning or discontinued learning. In this paper, an
intelligent tutoring system is proposed and it consists of several
modules working cooperatively in order to build an adaptive learning
environment for distance education. The operation of the system is
based on the result of Self-Organizing Map (SOM) to divide students
into different groups according to their learning ability and learning
interests and then provide them with suitable course content.
Accordingly, the problem of information overload and internet traffic
problem can be solved because the amount of traffic accessing the
same content is reduced.
Abstract: The paper describes ergonomics problems trend of
student at B5101 classroom building 2, Suranaree University of
Technology. The objective to survey ergonomics problems and effect
from use chairs for sitting in class room. The result from survey
method 100 student they use lecture chair for sitting in classroom
more than 2 hours/ day by RULA[1]. and Body discomfort survey[2].
The result from Body discomfort survey contribute fatigue problems
at neck, lower back, upper back and right shoulder 2.93, 2.91, 2.33,
1.75 respectively and result from RULA contribute fatigue problems
at neck, body and right upper arm 4.00, 3.75 and 3.00 respectively
are consistent. After that the researcher provide improvement plan
for design new chair support student fatigue reduction by prepare
data of sample anthropometry and design ergonomics chair prototype
3 unit. Then sample 100 student trial to use new chair and evaluate
again by RULA, Body discomfort and satisfaction. The result from
trial new chair after improvement by RULA present fatigue reduction
average of head and neck from 4.00 to 2.25 , body and trunk from
3.75 to 2.00 and arm force from 1.00 to 0.25 respectively. The result
from trial new chair after improvement by Body discomfort present
fatigue reduction average of lower back from 2.91 to 0.87, neck from
2.93 to 1.24, upper back 2.33 to 0.84 and right upper arm from 1.75
to 0.74. That statistical of RULA and Body discomfort survey
present fatigue reduction after improvement significance with a
confidence level of 95% (p-value 0.05). When analyzing the
relationship of fatigue as part of the body by Chi – square test during
RULA and Body discomfort that before and after improvements were
consistent with the significant level of confidence 95% (p-value 0.05)
. Moreover the students satisfaction result from trial with a new chair
for 30 minutes [3]. 72 percent very satisfied of the folding of the
secondary writing simple 66% the width of the writing plate, 64% the
suitability of the writing plate, 62% of soft seat cushion and 61%
easy to seat the chair.
Abstract: Reachability graph (RG) generation suffers from the
problem of exponential space and time complexity. To alleviate the
more critical problem of time complexity, this paper presents the new
approach for RG generation for the Petri net (PN) models of parallel
processes. Independent RGs for each parallel process in the PN
structure are generated in parallel and cross-product of these RGs
turns into the exhaustive state space from which the RG of given
parallel system is determined. The complexity analysis of the
presented algorithm illuminates significant decrease in the time
complexity cost of RG generation. The proposed technique is
applicable to parallel programs having multiple threads with the
synchronization problem.
Abstract: In order to enhance the aircraft survivability, the
infrared signatures emitted by hot engine parts should be determined
exactly. For its reduction it is necessary for the rear fuselage
temperature to be decreased. In this study, numerical modeling of flow
fields and heat transfer characteristics of an aircraft nozzle is
performed and its temperature distribution along each component wall
is predicted. The radiation shield is expected to reduce the skin
temperature of rear fuselage. The effect of material characteristic of
radiation shield on the heat transfer is also investigated. Through this
numerical analysis, design parameters related to the susceptibility of
aircraft are examined.
Abstract: Leprosy is an infectious disease caused by
Mycobacterium Leprae, this disease, generally, compromises
the neural fibers, leading to the development of disability.
Disabilities are changes that limit daily activities or social life
of a normal individual. When comes to leprosy, the study of
disability considered the functional limitation (physical
disabilities), the limitation of activity and social participation,
which are measured respectively by the scales: EHF, SALSA
and PARTICIPATION SCALE. The objective of this work is
to propose an on-line monitoring of leprosy patients, which is
based on information scales EHF, SALSA and
PARTICIPATION SCALE. It is expected that the proposed
system is applied in monitoring the patient during treatment
and after healing therapy of the disease. The correlations that
the system is between the scales create a variety of
information, presented the state of the patient and full of
changes or reductions in disability. The system provides
reports with information from each of the scales and the
relationships that exist between them. This way, health
professionals, with access to patient information, can
intervene with techniques for the Prevention of Disability.
Through the automated scale, the system shows the level of
the patient and allows the patient, or the responsible, to take a
preventive measure. With an online system, it is possible take
the assessments and monitor patients from anywhere.