Abstract: In the real application of active control systems to
mitigate the response of structures subjected to sever external
excitations such as earthquake and wind induced vibrations, since the
capacity of actuators is limited then the actuators saturate. Hence, in
designing controllers for linear and nonlinear structures under sever
earthquakes, the actuator saturation should be considered as a
constraint. In this paper optimal design of active controllers for
nonlinear structures by considering the actuator saturation has been
studied. To this end a method has been proposed based on defining
an optimization problem which considers the minimizing of the
maximum displacement of the structure as objective when a limited
capacity for actuator has been used as a constraint in optimization
problem. To evaluate the effectiveness of the proposed method, a
single degree of freedom (SDF) structure with a bilinear hysteretic
behavior has been simulated under a white noise ground acceleration
of different amplitudes. Active tendon control mechanism, comprised
of pre-stressed tendons and an actuator, and extended nonlinear
Newmark method based instantaneous optimal control algorithm
have been used as active control mechanism and algorithm. To
enhance the efficiency of the controllers, the weights corresponding
to displacement, velocity, acceleration and control force in the
performance index have been found by using the Distributed Genetic
Algorithm (DGA). According to the results it has been concluded
that the proposed method has been effective in considering the
actuator saturation in designing optimal controllers for nonlinear
frames. Also it has been shown that the actuator capacity and the
average value of required control force are two important factors in
designing nonlinear controllers for considering the actuator
saturation.
Abstract: Many medical devices are driven by motor pumps. Some researchers reported that the vibration mainly affected medical devices using a motor pump. The purpose of this study was to examine the effect of stiffness and damping coefficient in a 3-dimensional (3D) model of a motor pump and spring. In the present paper, experimental and mathematical tests for the moments of inertia of the 3D model and the material properties were investigated by an INSTRON machine. The response surfaces could be generated by using 3D multi-body analysis and the design of experiment method. It showed that differences in contours of the response surface were clearly found for the particular area. Displacement of the center of the motor pump was decreased at K≈2000 N/M, C≈12.5 N-sec/M. However, the frequency was increased at K≈2000 N/M, C≈15 N-sec/M. In this study, this study suggested experimental technique for vibration reduction for a motor pump in medical device. The combined method suggested in this study will greatly contribute to design of medical devices concerning vibration and noise intervention.
Abstract: Biochemical Oxygen Demand (BOD) is a measure of
the oxygen used in bacteria mediated oxidation of organic substances
in water and wastewater. Theoretically an infinite time is required for
complete biochemical oxidation of organic matter, but the
measurement is made over 5-days at 20 0C or 3-days at 27 0C test
period with or without dilution. Researchers have worked to further
reduce the time of measurement.
The objective of this paper is to review advancement made in
BOD measurement primarily to minimize the time and negate the
measurement difficulties. Survey of literature review in four such
techniques namely BOD-BARTTM, Biosensors, Ferricyanidemediated
approach, luminous bacterial immobilized chip method.
Basic principle, method of determination, data validation and their
advantage and disadvantages have been incorporated of each of the
methods.
In the BOD-BARTTM method the time lag is calculated for the
system to change from oxidative to reductive state. BIOSENSORS
are the biological sensing element with a transducer which produces
a signal proportional to the analyte concentration. Microbial species
has its metabolic deficiencies. Co-immobilization of bacteria using
sol-gel biosensor increases the range of substrate. In ferricyanidemediated
approach, ferricyanide has been used as e-acceptor instead
of oxygen. In Luminous bacterial cells-immobilized chip method,
bacterial bioluminescence which is caused by lux genes was
observed. Physiological responses is measured and correlated to
BOD due to reduction or emission.
There is a scope to further probe into the rapid estimation of BOD.
Abstract: This study extends research on the relationship
between marketing strategy and market segmentation by
investigating on market segments in the cement industry.
Competitive strength and rivals distance from the factory were used
as business environment. A three segment (positive, neutral or
indifferent and zero zones) were identified as strategic segments. For
each segment a marketing strategy (aggressive, defensive and
decline) were developed. This study employed data from cement
industry to fulfill two objectives, the first is to give a framework to
the segmentation of cement industry and the second is developing
marketing strategy with varying competitive strength. Fifty six
questionnaires containing close-and open-ended questions were
collected and analyzed. Results supported the theory that segments
tend to be more aggressive than defensive when competitive strength
increases. It is concluded that high strength segments follow total
market coverage, concentric diversification and frontal attack to their
competitors. With decreased competitive strength, Business tends to
follow multi-market strategy, product modification/improvement and
flank attack to direct competitors for this kind of segments. Segments
with weak competitive strength followed focus strategy and decline
strategy.
Abstract: The current study describes a multi-objective optimization technique for positioning of houses in a residential neighborhood. The main task is the placement of residential houses in a favorable configuration satisfying a number of objectives. Solving the house layout problem is a challenging task. It requires an iterative approach to satisfy design requirements (e.g. energy efficiency, skyview, daylight, roads network, visual privacy, and clear access to favorite views). These design requirements vary from one project to another based on location and client preferences. In the Gulf region, the most important socio-cultural factor is the visual privacy in indoor space. Hence, most of the residential houses in this region are surrounded by high fences to provide privacy, which has a direct impact on other requirements (e.g. daylight and direction to favorite views). This investigation introduces a novel technique to optimally locate and orient residential buildings to satisfy a set of design requirements. The developed technique explores the search space for possible solutions. This study considers two dimensional house planning problems. However, it can be extended to solve three dimensional cases.
Abstract: Many algorithms are available for sorting the unordered elements. Most important of them are Bubble sort, Heap sort, Insertion sort and Shell sort. These algorithms have their own pros and cons. Shell Sort which is an enhanced version of insertion sort, reduces the number of swaps of the elements being sorted to minimize the complexity and time as compared to insertion sort. Shell sort improves the efficiency of insertion sort by quickly shifting values to their destination. Average sort time is O(n1.25), while worst-case time is O(n1.5). It performs certain iterations. In each iteration it swaps some elements of the array in such a way that in last iteration when the value of h is one, the number of swaps will be reduced. Donald L. Shell invented a formula to calculate the value of ?h?. this work focuses to identify some improvement in the conventional Shell sort algorithm. ''Enhanced Shell Sort algorithm'' is an improvement in the algorithm to calculate the value of 'h'. It has been observed that by applying this algorithm, number of swaps can be reduced up to 60 percent as compared to the existing algorithm. In some other cases this enhancement was found faster than the existing algorithms available.
Abstract: The nonlinear damping behavior is usually ignored in
the design of a miniature moving-coil loudspeaker. But when the
loudspeaker operated in air, the damping parameter varies with the
voice-coil displacement corresponding due to viscous air flow. The
present paper presents an identification model as inverse problem to
identify the nonlinear damping parameter in the lumped parameter
model for the loudspeaker. Theoretical results for the nonlinear
damping are verified by using laser displacement measurement
scanner. These results indicate that the damping parameter has the
greatly different nonlinearity between in air and vacuum. It is believed
that the results of the present work can be applied in diagnosis and
sound quality improvement of a miniature loudspeaker.
Abstract: Never has a revolution affected all aspects of
humanity as the communication revolution during the past two
decades. This revolution, with all its advances and utilities, swept the
world thus becoming an integral part of our lives, hence giving way
to emerging applications at the social, economic, political, and
educational levels. More specifically, such applications have changed
the delivery system through which learning is acquired by students.
Interaction with educators, accessibility to content, and creative
delivery options are but a few facets of the new learning experience
now being offered through the use of technology in the educational
field. With different success rates, third world countries have tried to
pace themselves with use of educational technology in advanced
parts of the world. One such country is the small rich-oil state of
Kuwait which has tried to adopt the e-educational model, however,
an evaluation of such trial is yet to be done. This study aimed to fill
the void of research conducted around that topic. The study explored
students' acceptance of incorporating communication technologies in
higher education in Kuwait. Students' responses to survey questions
presented an overview of the e-learning experience in this country,
and drew a framework through which implications and suggestions
for future research were discussed to better serve the advancement of
e-education in developing countries.
Abstract: Soil microbial activity is adversely affected by pollutants such as heavy metals, antibiotics and pesticides. Organic amendments including sewage sludge, municipal compost and vermicompost are recently used to improve soil structure and fertility. But, these materials contain heavy metals including Pb, Cd, Zn, Ni and Cu that are toxic to soil microorganisms and may lead to occurrence of more tolerant microbes. Among these, Pb is the most abundant and has more negative effect on soil microbial ecology. In this study, Pb levels of 0, 100, 200, 300, 400 and 500 mg Pb [as Pb(NO3)2] per kg soil were added to the pots containing 2 kg of a loamy soil and incubated for 6 months at 25°C with soil moisture of - 0.3 MPa. Dehydrogenase activity of soil as a measure of microbial activity was determined on 15, 30, 90 and 180 days after incubation. Triphenyl tetrazolium chloride (TTC) was used as an electron acceptor in this assay. PICTs (IC50 values) were calculated for each Pb level and incubation time. Soil microbial activity was decreased by increasing Pb level during 30 days of incubation but the induced tolerance appeared on day 90 and thereafter. During 90 to 180 days of incubation, the PICT was gradually developed by increasing Pb level up to 200 mg kg-1, but the rate of enhancement was steeper at higher concentrations.
Abstract: Designing a simulated system and training it to optimize its tasks in simulated environment helps the designers to avoid problems that may appear when designing the system directly in real world. These problems are: time consuming, high cost, high errors percentage and low efficiency and accuracy of the system. The proposed system will investigate and improve the efficiency and accuracy of a simulated robot to choose correct behavior to perform its task. In this paper, machine learning, which uses genetic algorithm, is adopted. This type of machine learning is called genetic-based machine learning in which a distributed classifier system is used to improve the efficiency and accuracy of the robot. Consequently, it helps the robot to achieve optimal action.
Abstract: Fuzzy logic system (FLS) is used in this study to
predict the tractive performance in terms of traction force, and
motion resistance for an intelligent air cushion track vehicle while it
operates in the swamp peat. The system is effective to control the
intelligent air –cushion system with measuring the vehicle traction
force (TF), motion resistance (MR), cushion clearance height (CH)
and cushion pressure (CP). Ultrasonic displacement sensor, pull-in
solenoid electromagnetic switch, pressure control sensor, micro
controller, and battery pH sensor are incorporated with the Fuzzy
logic system to investigate experimentally the TF, MR, CH, and CP.
In this study, a comparison for tractive performance of an intelligent
air cushion track vehicle has been performed with the results obtained
from the predicted values of FLS and experimental actual values. The
mean relative error of actual and predicted values from the FLS
model on traction force, and total motion resistance are found as 5.58
%, and 6.78 % respectively. For all parameters, the relative error of
predicted values are found to be less than the acceptable limits. The
goodness of fit of the prediction values from the FLS model on TF,
and MR are found as 0.90, and 0.98 respectively.
Abstract: This paper describes the challenges on the requirements engineering for developing an enterprise applications in higher
education environment. The development activities include software implementation, maintenance, and enhancement and support for online
transaction processing and overnight batch processing.
Generally, an enterprise application for higher education environment
may include Student Information System (SIS), HR/Payroll system,
Financial Systems etc. By the way, there are so many challenges in
requirement engineering phases in order to provide two distinctive
services that are production processing support and systems
development.
Abstract: The higher compounded growth rates coupled with
favourable demographics in emerging markets portend abundant
opportunities for multinational organizations. With many
organizations competing for talent in these growing markets, their
ability to succeed will depend on their understanding of local
workforce needs and aspirations. Using data from the Towers Watson
2010 Global Workforce Study, this paper highlights differences in
employee engagement, turnover risks, and attraction and retention
drivers between the two markets. Apart from looking at the
traditional drivers of employee engagement, the study also explores
the value placed by employees on elements like a strong senior
leadership, managerial capabilities and career advancement
opportunities. Results reveal that emerging markets employees seem
to be more engaged and value the non-traditional elements more
highly than the developed markets employees.
Abstract: Very few studies have examined performance
implications of strategic alliance announcements in the information
technologies industry from a resource-based view. Furthermore, none
of these studies have investigated resource congruence and alliance
motive as potential sources of abnormal firm performance. This paper
extends upon current resource-based literature to discover and explore
linkages between these concepts and the practical performance of
strategic alliances. This study finds that strategic alliance
announcements have provided overall abnormal positive returns, and
that marketing alliances with marketing resource incongruence have
also contributed to significant firm performance.
Abstract: From past many decades human beings are suffering
from plethora of natural disasters. Occurrence of disasters is a
frequent process; it changes conceptual myths as more and more
advancement are made. Although we are living in technological era
but in developing countries like Pakistan disasters are shaped by
socially constructed roles. The need is to understand the most
vulnerable group of society i.e. females; their issues are complex in
nature because of undermined gender status in the society. There is a
need to identify maximum issues regarding females and to enhance
the achievement of millennium development goals (MDGs). Gender
issues are of great concern all around the globe including Pakistan.
Here female visibility in society is low, and also during disasters, the
failure to understand the reality that concentrates on double burden
including productive and reproductive care. Women have to
contribute a lot in society so we need to make them more disaster
resilient. For this non-structural measures like awareness, trainings
and education must be carried out. In rural and in urban settings in
any disaster like earthquake or flood, elements like gender
perspective, their age, physical health, demographic issues contribute
towards vulnerability. In Pakistan the gender issues in disasters were
of less concern before 2005 earthquake and 2010 floods. Significant
achievements are made after 2010 floods when gender and child cell
was created to provide all facilities to women and girls. The aim of
the study is to highlight all necessary facilities in a disaster to build
coping mechanism in females from basic rights till advance level
including education.
Abstract: Automatic Vehicle Identification (AVI) has many
applications in traffic systems (highway electronic toll collection, red
light violation enforcement, border and customs checkpoints, etc.).
License Plate Recognition is an effective form of AVI systems. In
this study, a smart and simple algorithm is presented for vehicle-s
license plate recognition system. The proposed algorithm consists of
three major parts: Extraction of plate region, segmentation of
characters and recognition of plate characters. For extracting the
plate region, edge detection algorithms and smearing algorithms are
used. In segmentation part, smearing algorithms, filtering and some
morphological algorithms are used. And finally statistical based
template matching is used for recognition of plate characters. The
performance of the proposed algorithm has been tested on real
images. Based on the experimental results, we noted that our
algorithm shows superior performance in car license plate
recognition.
Abstract: Properties of cement pastes with fine-ground ceramics
used as an alternative binder replacing Portland cement up to 20% of
its mass are investigated. At first, the particle size distribution of
cement and fine-ground ceramics is measured using laser analyser.
Then, the material properties are studied in the early hardening
period up to 28 days. The hydration process of studied materials is
monitored by electrical conductivity measurement using TDR
sensors. The changes of materials- structures within the hardening are
observed using pore size distribution measurement. The compressive
strength measurements are done as well. Experimental results show
that the replacement of Portland cement by fine-ground ceramics in
the amount of up to 20% by mass is acceptable solution from the
mechanical point of view. One can also assume similar physical
properties of designed materials to the reference material with only
Portland cement as binder.
Abstract: In the analysis of structures, the nonlinear effects due to large displacement, large rotation and materially-nonlinear are very important and must be considered for the reliable analysis. The non-linear fmite element analysis has potential as usable and reliable means for analyzing of civil structures with the availability of computer technology. In this research the large displacements and materially nonlinear behavior of shear wall is presented with developing of fmite element code using the standard Galerkin weighted residual formulation. Two-dimensional plane stress model was carried out to present the shear wall response. Total Lagangian formulation, which is computationally more effective, is used in the formulation of stiffness matrices and the Newton-Raphson method is applied for the solution of nonlinear transient equations. The details of the program formulation are highlighted and the results of the analyses are presented, along with a comparison of the response of the structure with Ansys software results. The presented model in this paper can be developed for nonlinear analysis of civil engineering structures with different material behavior and complicated geometry.
Abstract: Several different cements have been tested to evaluate
their potential to leach calcium, chromium and aluminum ions in soft
water environment. The research allows comparing some different
cements in order to the potential risk of water contamination. This
can be done only in the same environment. To reach the results in
reasonable short time intervals and to make heavy metals
measurements with high accuracy, demineralized water was used. In
this case the conditions of experiments are far away from the water
supply practice, but short time experiments and measurably high
concentrations of elements in the water solution are an important
advantage. Moreover leaching mechanisms can be recognized, our
experiments reported here refer to this kind of cements evaluation.
Abstract: In spite of the advent of new materials, clay bricks
remain, arguably, the most popular construction materials today.
Nevertheless the low cost and versatility of clay bricks cannot always
be associated with high environmental and sustainable values,
especially in terms of raw material sources and manufacturing
processes. At the same time, the worldwide agricultural footprint is
fast growing, with vast agricultural land cultivation and active
expansion of the agro-based industry. The resulting large quantities of
agricultural wastes, unfortunately, are not always well managed or
utilised. These wastes can be recycled, such as by retrieving fibres
from disposed leaves and fruit bunches, and then incorporated in
brick-making. This way the clay bricks are made a 'greener' building
material and the discarded natural wastes can be reutilised, avoiding
otherwise wasteful landfill and harmful open incineration. This study
examined the physical and mechanical properties of clay bricks made
by adding two natural fibres to a clay-water mixture, with baked and
non-baked conditions. The fibres were sourced from pineapple leaves
(PF) and oil palm fruit bunch (OF), and added within the range of
0.25-0.75 %. Cement was added as a binder to the mixture at 5-15 %.
Although the two fibres had different effects on the bricks produced,
cement appeared to dominate the compressive strength. The
non-baked bricks disintegrated when submerged in water, while the
baked ones displayed cement-dependent characteristics in
water-absorption and density changes. Interestingly, further increase
in fibre content did not cause significant density decrease in both the
baked and non-baked bricks.