Abstract: In This paper, the behavior of eccentric braced frame
(EBF) is studied with replacing friction damper (FD) in confluence of these braces, in 5 and 10-storey steel frames. For FD system, the main step is to determine the slip load. For this reason, the performance indexes include roof displacement, base shear, dissipated energy and relative performance should be investigated. In
nonlinear dynamic analysis, the response of structure to three
earthquake records has been obtained and the values of roof
displacement, base shear and column axial force for FD and EBF
frames have been compared. The results demonstrate that use of the FD in frames, in comparison with the EBF, substantially reduces the roof displacement, column axial force and base shear. The obtained results show suitable performance of FD in higher storey structure in
comparison with the EBF.
Abstract: This main purpose of the study reported here was to
investigate the extent to which the form of school
governance (particularly decision-making) had an impact upon the
effectiveness of the school with reference to parental involvement,
planning and budgeting, professional development of teachers,
school facilities and resources, and student outcomes. Particular
attention was given to decision-making within the governance
arrangements. The study was based on four case studies of high
schools in New South Wales, Australia including one government
school, one independent Christian community school, one
independent Catholic school, and one Catholic systemic school.
The focus of the research was principals, teachers, parents, and
students of four schools with varying governance structures. To
gain a greater insight into the issues, the researchers collected
information by questionnaire, semi-structured interview, and
review of school key documents. This study found that it was not
so much structure but the centrality of the school Principal and the
way that the Principal perceived his/her roles in relation to others
that impacted most on school governance.
Abstract: Higher capacities of power plants together with
increased awareness on environmental considerations have led to
taller height of stacks. It is seen that strong wind can result in falling
of stacks. So, aerodynamic consideration of stacks is very important
in order to save the falling of stacks. One stack is not enough in
industries and power sectors and two or three stacks are required for
proper operation of the unit. It is very important to arrange the stacks
in proper way to resist their downfall. The present experimental
study concentrates on the mutual effect of three nearby stacks on
each other at three different arrangements, viz. linear, side-by-side
and triangular. The experiments find out the directions of resultant
forces acting on the stacks in different configurations so that proper
arrangement of supports can be made with respect to the wind
directionality obtained from local meteorological data. One can also
easily ascertain which stack is more vulnerable to wind in
comparison to the others for a particular configuration. Thus, this
study is important in studying the effect of wind force on three stacks
in different arrangements and is very helpful in placing the supports
in proper places in order to avoid failing of stack-like structures due
to wind.
Abstract: The use of synthetic retardants in polymeric insulated
cables is not uncommon in the high voltage engineering to study
electrical treeing phenomenon. However few studies on organic
materials for the same investigation have been carried. .This paper
describes the study on the effects of Oil Palm Empty Fruit Bunch
(OPEFB) microfiller on the tree initiation and propagation in silicone
rubber with different weight percentages (wt %) of filler to insulation
bulk material. The weight percentages used were 0 wt % and 1 wt %
respectively. It was found that the OPEFB retards the propagation of
the electrical treeing development. For tree inception study, the
addition of 1(wt %) OPEFB has increase the tree inception voltage of
silicone rubber. So, OPEFB is a potential retardant to the initiation
and growth of electrical treeing occurring in polymeric materials for
high voltage application. However more studies on the effects of
physical and electrical properties of OPEFB as a tree retardant
material are required.
Abstract: We developed a multi-camera control system that a (one) cameraman can operate several cameras at a compact studio. we analyzed a workflow of a cameraman of some program shootings with two cameras and clarified their heavy tasks. The system based on a dynamic workflow which adapts a program progressing and recommends of cameraman. we perform the automation of multicamera controls by modeling of studio environment and perform automatic camera adjustment for suitable angle of view with face detection. Our experiment at a real program shooting showed that one cameraman can carry out the task of shooting sufficiently.
Abstract: The ability of pomelo peel, a natural biosorbent, to remove Cd(II) ions from aqueous solution by biosorption was investigated. The experiments were carried out by batch method at 25 °C. The influence of solution pH, initial cadmium ion concentrations and contact times were evaluated. Cadmium ion removal increased significantly as the pH of the solution increased from pH 1 to pH 5. At pH 5, the cadmium ion removal reached a maximum value. The equilibrium process was described well by the Langmuir isotherm model, with a maximum biosorption capacity of 21.83 mg/g. The biosorption was relatively quick, (approx. 20 min). Biosorption kinetics followed a pseudo-second-order model. The result showed that pomelo peel was effective as a biosorbent for removing cadmium ions from aqueous solution. It is a low cost material that shows potential to be applied in wastewater technology for remediation of heavy metal contamination.
Abstract: In contrast to existing methods which do not take into account multiconnectivity in a broad sense of this term, we develop mathematical models and highly effective combination (BIEM and FDM) numerical methods of calculation of stationary and quasistationary temperature field of a profile part of a blade with convective cooling (from the point of view of realization on PC). The theoretical substantiation of these methods is proved by appropriate theorems. For it, converging quadrature processes have been developed and the estimations of errors in the terms of A.Ziqmound continuity modules have been received. For visualization of profiles are used: the method of the least squares with automatic conjecture, device spline, smooth replenishment and neural nets. Boundary conditions of heat exchange are determined from the solution of the corresponding integral equations and empirical relationships. The reliability of designed methods is proved by calculation and experimental investigations heat and hydraulic characteristics of the gas turbine first stage nozzle blade.
Abstract: Calcium magnesium acetate (CMA) is environmentally
benign deicing chemicals that can replace sodium chloride that is
widely used on roads and highways at present for snow and ice control
to provide safe driving conditions during winter. The price of CMA
from petroleum-derived acetic acid is quite expensive. The bamboo
vinegar is the by-product from bamboo charcoal production. The
bamboo vinegar was used to prepare calcium acetate as raw materials,
and its deicing and corrosive performances were studied in this paper.
The results show that the freezing temperature of calcium acetate is
lower than that of sodium chloride when they have same molar
concentration, the deicing performance of calcium acetate is better
than that of sodium chloride when they have same moles, while the
deicing performance of sodium chloride is better than that of calcium
acetate. The corrosion of sodium chloride on iron-nail and steel-nail is
larger than that of calcium acetate whether they have same mass
concentration or same molar concentration, and the corrosion of
sodium chloride and calcium acetate on iron-nail is larger than that on
steel-nail, and calcium acetate almost hasn't corrosion on steel-nail.
Abstract: The tensile properties of Mg-3%Al nanocrystalline
alloys were investigated at different test environment. Bulk
nanocrystalline samples of these alloy was successfully prepared by
mechanical alloying (MA) followed by cold compaction, sintering,
and hot extrusion process. The crystal size of the consolidated milled
sample was calculated by X-Ray line profile analysis. The
deformation mechanism and microstructural characteristic at
different test condition was discussed extensively. At room
temperature, relatively lower value of activation volume (AV) and
higher value of strain rate sensitivity (SRS) suggests that new rate
controlling mechanism accommodating plastic flow in the present
nanocrystalline sample. The deformation behavior and the
microstructural character of the present samples were discussed in
details.
Abstract: Production of hard-to-cut materials with uncoated carbide cutting tools in turning, not only cause tool life reduction but also, impairs the product surface roughness. In this paper, influence of hot machining method were studied and presented in two cases. Case1-Workpiece surface roughness quality with constant cutting parameter and 300 ºC initial workpiece surface temperature. Case 2- Tool temperature variation when cutting with two speeds 78.5 (m/min) and 51 (m/min). The workpiece material and tool used in this study were AISI 1060 steel (45HRC) and uncoated carbide TNNM 120408-SP10(SANDVIK Coromant) respectively. A gas flam heating source was used to preheating of the workpiece surface up to 300 ºC, causing reduction of yield stress about 15%. Results obtained experimentally, show that the method used can considerably improved surface quality of the workpiece.
Abstract: The paper presents a numerical investigation on the
rapid gas decompression in pure nitrogen which is made by using the
one-dimensional (1D) and three-dimensional (3D) mathematical
models of transient compressible non-isothermal fluid flow in pipes.
A 1D transient mathematical model of compressible thermal multicomponent
fluid mixture flow in pipes is presented. The set of the
mass, momentum and enthalpy conservation equations for gas phase
is solved in the model. Thermo-physical properties of multicomponent
gas mixture are calculated by solving the Equation of
State (EOS) model. The Soave-Redlich-Kwong (SRK-EOS) model is
chosen. This model is successfully validated on the experimental data
[1] and shows a good agreement with measurements. A 3D transient
mathematical model of compressible thermal single-component gas
flow in pipes, which is built by using the CFD Fluent code (ANSYS),
is presented in the paper. The set of unsteady Reynolds-averaged
conservation equations for gas phase is solved. Thermo-physical
properties of single-component gas are calculated by solving the Real
Gas Equation of State (EOS) model. The simplest case of gas
decompression in pure nitrogen is simulated using both 1D and 3D
models. The ability of both models to simulate the process of rapid
decompression with a high order of agreement with each other is
tested. Both, 1D and 3D numerical results show a good agreement
between each other. The numerical investigation shows that 3D CFD
model is very helpful in order to validate 1D simulation results if the
experimental data is absent or limited.
Abstract: Digital signature is a useful primitive to attain the integrity and authenticity in various wire or wireless communications. Proxy signature is one type of the digital signatures. It helps the proxy signer to sign messages on behalf of the original signer. It is very useful when the original signer (e.g. the president of a company) is not available to sign a specific document. If the original signer can not forge valid proxy signatures through impersonating the proxy signer, it will be robust in a virtual environment; thus the original signer can not shift any illegal action initiated by herself to the proxy signer. In this paper, we propose a new proxy signature scheme. The new scheme can prevent the original signer from impersonating the proxy signer to sign messages. The proposed scheme is based on the regular ElGamal signature. In addition, the fair privacy of the proxy signer is maintained. That means, the privacy of the proxy signer is preserved; and the privacy can be revealed when it is necessary.
Abstract: We discuss the convergence property of the minimum residual (MINRES) method for the solution of complex shifted Hermitian system (αI + H)x = f. Our convergence analysis shows that the method has a faster convergence than that for real shifted Hermitian system (Re(α)I + H)x = f under the condition Re(α) + λmin(H) > 0, and a larger imaginary part of the shift α has a better convergence property. Numerical experiments show such convergence properties.
Abstract: This paper highlights some interesting facts on South African-s waste situation and management strategies, in particular the Integrated Waste Management. South Africa supports a waste hierarchy by promoting cleaner production, waste minimisation, reuse, recycling and waste treatment with disposal and remediation as the last preferred options in waste management. The drivers for waste management techniques are identified as increased demand for waste service provision; increased demand for waste minimisation; recycling and recovery; land use, physical and environmental limitations; and socio-economic and demographic factors. The South African government recognizes the importance of scientific research as outlined on the white paper on Integrated Pollution and Waste Management (IP and WM) (DEAT, 2000).
Abstract: This paper focuses on systematic analysis and
controller design of the two-inertia STABILIZATION system,
considering the angular motion on a base body. This approach is
essential to the stabilization system to aim at a target under three or six
degrees of freedom base motion. Four controllers, such as
conventional PDF(Pseudo-Derivative Feedback) controller with
motor speed feedback, PDF controller with load speed feedback,
modified PDF controller with motor-load speed feedback and
feedforward controller added to modified PDF controller, are
suggested to improve reference tracking and disturbance rejection
performance. Characteristics and performance of each controller are
analyzed and validated by simulation in the case of the modified PDF
controller with and without a feedforward controller.
Abstract: This paper presents a solution for a robotic
manipulation problem. We formulate the problem as combining
target identification, tracking and interception. The task in our
solution is sensing a target on a conveyor belt and then intercepting
robot-s end-effector at a convenient rendezvous point. We used
an object recognition method which identifies the target and finds
its position from visualized scene picture, then the robot system
generates a solution for rendezvous problem using the target-s initial
position and belt velocity . The interception of the target and the
end-effector is executed at a convenient rendezvous point along the
target-s calculated trajectory. Experimental results are obtained using
a real platform with an industrial robot and a vision system over it.
Abstract: Estimates of temperature values at a specific time of day, from daytime and daily profiles, are needed for a number of environmental, ecological, agricultural and technical applications, ranging from natural hazards assessments, crop growth forecasting to design of solar energy systems. The scope of this research is to investigate the efficiency of data mining techniques in estimating minimum, maximum and mean temperature values. For this reason, a number of experiments have been conducted with well-known regression algorithms using temperature data from the city of Patras in Greece. The performance of these algorithms has been evaluated using standard statistical indicators, such as Correlation Coefficient, Root Mean Squared Error, etc.
Abstract: In the past, there were many bridge-s collapses due to
lack of bridge structural capacity information. Most of concrete
bridge health was relied on information from visual inspection, which
sometime was inadequate. This study was conducted in order to
investigate relationship between bridge structural condition and
bridge visual condition. This study was a part of a big project
conducted at Department of Highways of Thailand. In this study, 31
bridges including slab-type bridges, plank-girder bridges, prestressed
box-beam bridges, prestressed I-girder bridges and prestressed multibeam
bridges were selected for visual inspection and load test. It was
found a positive correlation between bridge appearance and bridge-s
load carrying capacity. However, statistical characteristic revealed
low correlation between them.
Abstract: This study investigates the investors- behavioral
reaction to the investment rating change announcements from the
views of behavioral finance. The empirical results indicate that
self-interest does affect the intention of securities firms to release
investment ratings for individual stocks. In addition, behavioral
pitfalls are also found in the response of retail investors to investment
rating change announcements.
Abstract: A novel feature selection strategy to improve the recognition accuracy on the faces that are affected due to nonuniform illumination, partial occlusions and varying expressions is proposed in this paper. This technique is applicable especially in scenarios where the possibility of obtaining a reliable intra-class probability distribution is minimal due to fewer numbers of training samples. Phase congruency features in an image are defined as the points where the Fourier components of that image are maximally inphase. These features are invariant to brightness and contrast of the image under consideration. This property allows to achieve the goal of lighting invariant face recognition. Phase congruency maps of the training samples are generated and a novel modular feature selection strategy is implemented. Smaller sub regions from a predefined neighborhood within the phase congruency images of the training samples are merged to obtain a large set of features. These features are arranged in the order of increasing distance between the sub regions involved in merging. The assumption behind the proposed implementation of the region merging and arrangement strategy is that, local dependencies among the pixels are more important than global dependencies. The obtained feature sets are then arranged in the decreasing order of discriminating capability using a criterion function, which is the ratio of the between class variance to the within class variance of the sample set, in the PCA domain. The results indicate high improvement in the classification performance compared to baseline algorithms.