Abstract: The present study concentrates on solving the along wind oscillation problem of a tall square building from first principles and across wind oscillation problem of the same from empirical relations obtained by experiments. The criterion for human comfort at the worst condition at the top floor of the building is being considered and a limiting value of height of a building for a given cross section is predicted. Numerical integrations are carried out as and when required. The results show severeness of across wind oscillations in comparison to along wind oscillation. The comfort criterion is combined with across wind oscillation results to determine the maximum allowable height of a building for a given square cross-section.
Abstract: While many studies have conducted the achievement
gap between groups of students in school districts, few studies have
utilized resilience research to investigate achievement gaps within
classrooms. This paper aims to summarize and discuss some recent
studies Waxman, Padr├│n, and their colleagues conducted, in which
they examined learning environment differences between resilient
and nonresilient students in reading and mathematics classrooms.
The classes consist of predominantly Hispanic elementary school
students from low-income families. These studies all incorporated
learning environment questionnaires and systematic observation
methods. Significant differences were found between resilient and
nonresilient students on their classroom learning environments and
classroom behaviors. The observation results indicate that the amount
and quality of teacher and student academic interaction are two of the
most influential variables that promote student outcomes. This paper
concludes by suggesting the following teacher practices to promote
resiliency in schools: (a) using feedback from classroom observation
and learning environment measures, (b) employing explicit teaching
practices; and (c) understanding students on a social and personal
level.
Abstract: In this paper, the details of an experimental method to measure the clamping force value at bolted connections due to application of wrenching torque to tighten the nut have been presented. A simplified bolted joint including a holed plate with a single bolt was considered to carry out the experiments. This method was designed based on Hooke-s law by measuring compressive axial strain of a steel bush placed between the nut and the plate. In the experimental procedure, the values of clamping force were calculated for seven different levels of applied torque, and this process was repeated three times for each level of the torque. Moreover, the effect of lubrication of threads on the clamping value was studied using the same method. In both conditions (dry and lubricated threads), relation between the torque and the clamping force have been displayed in graphs.
Abstract: This paper is to investigate the impplementation of security
mechanism in object oriented database system. Formal methods
plays an essential role in computer security due to its powerful expressiveness
and concise syntax and semantics. In this paper, both issues
of specification and implementation in database security environment
will be considered; and the database security is achieved through
the development of an efficient implementation of the specification
without compromising its originality and expressiveness.
Abstract: Concrete strength evaluated from compression tests
on cores is affected by several factors causing differences from the
in-situ strength at the location from which the core specimen was
extracted. Among the factors, there is the damage possibly occurring
during the drilling phase that generally leads to underestimate the
actual in-situ strength. In order to quantify this effect, in this study
two wide datasets have been examined, including: (i) about 500 core
specimens extracted from Reinforced Concrete existing structures,
and (ii) about 600 cube specimens taken during the construction of
new structures in the framework of routine acceptance control. The
two experimental datasets have been compared in terms of
compression strength and specific weight values, accounting for the
main factors affecting a concrete property, that is type and amount of
cement, aggregates' grading, type and maximum size of aggregates,
water/cement ratio, placing and curing modality, concrete age. The
results show that the magnitude of the strength reduction due to
drilling damage is strongly affected by the actual properties of
concrete, being inversely proportional to its strength. Therefore, the
application of a single value of the correction coefficient, as generally
suggested in the technical literature and in structural codes, appears
inappropriate. A set of values of the drilling damage coefficient is
suggested as a function of the strength obtained from compressive
tests on cores.
Abstract: Grid computing is a group of clusters connected over
high-speed networks that involves coordinating and sharing
computational power, data storage and network resources operating
across dynamic and geographically dispersed locations. Resource
management and job scheduling are critical tasks in grid computing.
Resource selection becomes challenging due to heterogeneity and
dynamic availability of resources. Job scheduling is a NP-complete
problem and different heuristics may be used to reach an optimal or
near optimal solution. This paper proposes a model for resource and
job scheduling in dynamic grid environment. The main focus is to
maximize the resource utilization and minimize processing time of
jobs. Grid resource selection strategy is based on Max Heap Tree
(MHT) that best suits for large scale application and root node of
MHT is selected for job submission. Job grouping concept is used to
maximize resource utilization for scheduling of jobs in grid
computing. Proposed resource selection model and job grouping
concept are used to enhance scalability, robustness, efficiency and
load balancing ability of the grid.
Abstract: Iron oxide nanoparticle was synthesized by reactive-precipitation method followed by high speed centrifuge and phase transfer in order to stabilized nanoparticles in the solvent. Particle size of SPIO was 8.2 nm by SEM, and the hydraulic radius was 17.5 nm by dynamic light scattering method. Coercivity and saturated magnetism were determined by VSM (vibrating sample magnetometer), coercivity of nanoparticle was lower than 10 Hc, and the saturated magnetism was higher than 65 emu/g. Stabilized SPIO was then transferred to aqueous phase by reacted with excess amount of poly (ethylene glycol) (PEG) silane. After filtration and dialysis, the SPIO T2 contrast agent was ready to use. The hydraulic radius of final product was about 70~100 nm, the relaxation rates R2 (1/T2) measured by magnetic resonance imaging (MRI) was larger than 200(sec-1).
Abstract: In this paper effect of stator slots structure and
switching angle on a cylindrical single-phase brushless direct current
motor (BLDC) is analyzed. BLDC motor with three different
structures for stator slots is designed by using RMxprt software and
efficiency of BLDC motor for different structures in full-load
condition has been presented. Then the BLDC motor in different
conditions by using Maxwell 3D software is designed and with finite
element method is analyzed electromagnetically. At the end with the
use of MATLAB software influence of switching angle on motor
performance investigated and optimal angle has been determined.
The results indicate that with correct choosing of stator slots structure
and switching angle, maximum efficiency can be found.
Abstract: In the present study, fracture behavior of woven
fabric-reinforced glass/epoxy composite laminates under mode III
crack growth was experimentally investigated and numerically
modeled. Two methods were used for the calculation of the strain
energy release rate: the experimental compliance calibration (CC)
method and the Virtual Crack Closure Technique (VCCT). To
achieve this aim ECT (Edge Crack Torsion) was used to evaluate
fracture toughness in mode III loading (out of plane-shear) at
different crack lengths. Load–displacement and associated energy
release rates were obtained for various case of interest. To
calculate fracture toughness JIII, two criteria were considered
including non-linearity and maximum points in load-displacement
curve and it is observed that JIII increases with the crack length
increase. Both the experimental compliance method and the virtual
crack closure technique proved applicable for the interpretation of the
fracture mechanics data of woven glass/epoxy laminates in mode III.
Abstract: Vehicle suspension design must fulfill
some conflicting criteria. Among those is ride comfort
which is attained by minimizing the acceleration
transmitted to the sprung mass, via suspension spring
and damper. Also good handling of a vehicle is a
desirable property which requires stiff suspension and
therefore is in contrast with a vehicle with good ride.
Among the other desirable features of a suspension is
the minimization of the maximum travel of suspension.
This travel which is called suspension working space in
vehicle dynamics literature is also a design constraint
and it favors good ride. In this research a full car 8
degrees of freedom model has been developed and the
three above mentioned criteria, namely: ride, handling
and working space has been adopted as objective
functions. The Multi Objective Programming (MOP)
discipline has been used to find the Pareto Front and
some reasoning used to chose a design point between
these non dominated points of Pareto Front.
Abstract: In this paper, we present a preconditioned AOR-type iterative method for solving the linear systems Ax = b, where A is a Z-matrix. And give some comparison theorems to show that the rate of convergence of the preconditioned AOR-type iterative method is faster than the rate of convergence of the AOR-type iterative method.
Abstract: The major problem that wireless communication
systems undergo is multipath fading caused by scattering of the
transmitted signal. However, we can treat multipath propagation as
multiple channels between the transmitter and receiver to improve
the signal-to-scattering-noise ratio. While using Single Input
Multiple Output (SIMO) systems, the diversity receivers extract
multiple signal branches or copies of the same signal received from
different channels and apply gain combining schemes such as Root
Mean Square Gain Combining (RMSGC). RMSGC asymptotically
yields an identical performance to that of the theoretically optimal
Maximum Ratio Combining (MRC) for values of mean Signal-to-
Noise-Ratio (SNR) above a certain threshold value without the need
for SNR estimation. This paper introduces an improvement of
RMSGC using two different issues. We found that post-detection and
de-noising the received signals improve the performance of RMSGC
and lower the threshold SNR.
Abstract: This document details the process of developing a
wireless device that captures the basic movements of the foot (plantar
flexion, dorsal flexion, abduction, adduction.), and the knee
movement (flexion). It implements a motion capture system by using
a hardware based on optical fiber sensors, due to the advantages in
terms of scope, noise immunity and speed of data transmission and
reception. The operating principle used by this system is the detection
and transmission of joint movement by mechanical elements and
their respective measurement by optical ones (in this case infrared).
Likewise, Visual Basic software is used for reception, analysis and
signal processing of data acquired by the device, generating a 3D
graphical representation in real time of each movement. The result is
a boot in charge of capturing the movement, a transmission module
(Implementing Xbee Technology) and a receiver module for
receiving information and sending it to the PC for their respective
processing.
The main idea with this device is to help on topics such as
bioengineering and medicine, by helping to improve the quality of
life and movement analysis.
Abstract: Project managers are the ultimate responsible for the
overall characteristics of a project, i.e. they should deliver the project
on time with minimum cost and with maximum quality. It is vital for
any manager to decide a trade-off between these conflicting
objectives and they will be benefited of any scientific decision
support tool. Our work will try to determine optimal solutions (rather
than a single optimal solution) from which the project manager will
select his desirable choice to run the project. In this paper, the
problem in project scheduling notated as
(1,T|cpm,disc,mu|curve:quality,time,cost) will be studied. The
problem is multi-objective and the purpose is finding the Pareto
optimal front of time, cost and quality of a project
(curve:quality,time,cost), whose activities belong to a start to finish
activity relationship network (cpm) and they can be done in different
possible modes (mu) which are non-continuous or discrete (disc), and
each mode has a different cost, time and quality . The project is
constrained to a non-renewable resource i.e. money (1,T). Because
the problem is NP-Hard, to solve the problem, a meta-heuristic is
developed based on a version of genetic algorithm specially adapted
to solve multi-objective problems namely FastPGA. A sample project
with 30 activities is generated and then solved by the proposed
method.
Abstract: In this paper, a Biochemical Methane Potential (BMP)
test provides a measure of the energy production potential from codigestion
between the frozen seafood wastewater and the decanter
cake. The experiments were conducted in laboratory-scale. The
suitable ratio of the frozen seafood wastewater and the decanter cake
was observed in the BMP test. The ratio of the co-digestion between
the frozen seafood wastewater and the decanter cake has impacts on
the biogas production and energy production potential. The best
performance for energy production potential using BMP test
observed from the 180 ml of the frozen seafood wastewater and 10 g
of the decanter cake ratio. This ratio provided the maximum methane
production at 0.351 l CH4/g TCODremoval. The removal efficiencies
are 76.18%, 83.55%, 43.16% and 56.76% at TCOD, SCOD, TS and
VS, respectively. The result can be concluded that the decanter cake
can improve the energy production potential of the frozen seafood
wastewater. The energy provides from co-digestion between frozen
seafood wastewater and decanter cake approximately 19x109
MJ/year in Thailand.
Abstract: Negation is useful in the majority of the real world applications. However, its introduction leads to semantic and canonical problems. SEPN nets are well adapted extension of predicate nets for the definition and manipulation of stratified programs. This formalism is characterized by two main contributions. The first concerns the management of the whole class of stratified programs. The second contribution is related to usual operations optimization (maximal stratification, incremental updates ...). We propose, in this paper, useful algorithms for manipulating stratified programs using SEPN. These algorithms were implemented and validated with STRPRO tool.
Abstract: This study was to investigate the performance of
hybrid solvents blended between primary, secondary, or tertiary
amines and piperazine (PZ) for CO2 removal from flue gas in terms
of CO2 absorption capacity and regeneration efficiency at 90 oC.
Alkanolamines used in this work were monoethanolamine (MEA),
diethanolamine (DEA), and triethanolamine (TEA). The CO2
absorption was experimentally examined under atmospheric pressure
and room temperature. The results show that MEA blend with PZ
provided the maximum CO2 absorption capacity of 0.50 mol
CO2/mol amine while TEA provided the minimum CO2 absorption
capacity of 0.30 mol CO2/mol amine. TEA was easier to regenerate
for both first cycle and second cycle with less loss of absorption
capacity. The regeneration efficiency of TEA was 95.09 and 92.89 %,
for the first and second generation cycles, respectively.
Abstract: Superplastic deformation and high temperature load
relaxation behavior of coarse-grained iron aluminides with the
composition of Fe-28 at.% Al have been investigated. A series of load
relaxation and tensile tests were conducted at temperatures ranging
from 600 to 850oC. The flow curves obtained from load relaxation
tests were found to have a sigmoidal shape and to exhibit stress vs.
strain rate data in a very wide strain rate range from 10-7/s to 10-2/s.
Tensile tests have been conducted at various initial strain rates ranging
from 3×10-5/s to 1×10-2/s. Maximum elongation of ~500 % was
obtained at the initial strain rate of 3×10-5/s and the maximum strain
rate sensitivity was found to be 0.68 at 850oC in binary Fe-28Al alloy.
Microstructure observation through the optical microscopy (OM) and
the electron back-scattered diffraction (EBSD) technique has been
carried out on the deformed specimens and it has revealed the
evidences for grain boundary migration and grain refinement to occur
during superplastic deformation, suggesting the dynamic
recrystallization mechanism. The addition of Cr by the amount of 5
at.% appeared to deteriorate the superplasticity of the binary iron
aluminide. By applying the internal variable theory of structural
superplasticity, the addition of Cr has been revealed to lower the
contribution of the frictional resistance to dislocation glide during high
temperature deformation of the Fe3Al alloy.
Abstract: The study was designed to develop a measurement of
the positive emotion regulation questionnaire (PERQ) that assesses
positive emotion regulation strategies through self-report. The 14
items developed for the surveying instrument of the study were based
upon literatures regarding elements of positive regulation strategies.
319 elementary students (age ranging from 12 to14) were recruited
among three public elementary schools to survey on their use of
positive emotion regulation strategies. Of 319 subjects, 20 invalid
questionnaire s yielded a response rate of 92%. The data collected
wasanalyzed through methods such as item analysis, factor analysis,
and structural equation models. In reference to the results from item
analysis, the formal survey instrument was reduced to 11 items. A
principal axis factor analysis with varimax was performed on
responses, resulting in a 2-factor equation (savoring strategy and
neutralizing strategy), which accounted for 55.5% of the total
variance. Then, the two-factor structure of scale was also identified by
structural equation models. Finally, the reliability coefficients of the
two factors were Cronbach-s α .92 and .74. Gender difference was
only found in savoring strategy. In conclusion, the positive emotion
regulation strategies questionnaire offers a brief, internally consistent,
and valid self-report measure for understanding the emotional
regulation strategies of children that may be useful to researchers and
applied professionals.
Abstract: Distance education program is a dimension of contemporary and new education technologies. Concepts and applications in this field are the results of a series of educational demands and developments in various communication and education technologies. Distance education applications have some conceptual bases. These are creating new education opportunities, realizing work-education unity, getting democratic in education, lifelong education, tendency to individual matters, effective use of institutions, integration of technology and education, tendency to individual and social needs, taking three dimensional integration as the main principle (publishing, printed materials and face to face education), reaching maximum mass, individual and mass education integrity and education demand and financial matters balance. Economics, Business Administration and Open Education faculties, which have been giving education within Anadolu University since 1982 in Turkey, are carrying on education with nearly 1.000.000 students. The aim of this study is to determine organizational commitment levels of students who have been studying at Anadolu University Economics, Business Administration and Open Education faculties in the scope of affective, continuance and nominative commitment in Allen&Meyer model. In the study, organizational commitment of the Economics, Business Administration and Open Education faculty students, who are receiving education by means of distance education, to their faculties is dealt after introducing Anadolu University Distance Education system which gives higher education via distance education method in Turkey. In order to increase the success level of faculties it is required for students to have high level of organizational commitment to their faculties. A questionnaire has been applied by using “Organizational Commitment Scale", developed by Meyer&Allen to determine organizational commitments of Economics, Business Administration and Open Education students. Organizational commitment is dealt with as affective, continuance and nominative commitment. The questionnaire was applied face to face to randomly chosen 500 students living in Eskişehir and the data was downloaded to the computer by using SPSS program and the results were analyzed in terms of demographic features (gender, age, marital status, years of study, work and income level) of students by using frequency test, ttest and ANOVA test. As a result of these analyses, when the comments of Open Education Faculty students on levels of affective, continuance and nominative commitment to their faculties were examined, it has been revealed that continuance commitment level has the highest rate. Among the female participants; continuance commitment is high in the age range of 30-40, for normative commitment it is 17-22. However no dominant age range was defined for affective commitment. Regarding the marital status; continuance commitment average is higher among married participants; but nominative affective commitment average is higher among single participants. As to the years of study, affective and continuance commitment is higher among senior students while normative commitment is higher among junior students. Moreover; in terms of continuance, affective and normative commitment, those who do not work and have low income have higher level of all there commitment types than those who work and have relatively high income.