Abstract: The aim of this investigation is to study the
performance of the new generation of the PVD coated grade and to
map the influence of cutting conditions on the tool life in milling of
ADI (Austempered Ductile Iron). The results show that chipping is
the main wear mechanism which determines the tool life in dry
condition and notch wear in wet condition for this application. This
due to the different stress mechanisms and preexisting cracks in the
coating. The wear development shows clearly that the new PVD
coating (C20) has the best ability to delay the chipping growth. It
was also found that a high content of Al in the new coating (C20)
was especially favorable compared to a TiAlN multilayer with lower
Al content (C30) or CVD coating. This is due to fine grains and low
compressive stress level in the coating which increase the coating
ability to withstand the mechanical and thermal impact. It was also
found that the use of coolant decreases the tool life with 70-80%
compare to dry milling.
Abstract: A potential flow model is used to study the unsteady
flow past two airfoils in configuration, each of which is suddenly set
into motion. The airfoil bound vortices are modeled using lumped
vortex elements and the wake behind the airfoil is modeled by discrete
vortices. This consists of solving a steady state flow problem at each
time-step where unsteadiness is incorporated through the “zero normal
flow on a solid surface" boundary condition at every time instant.
Additionally, along with the “zero normal flow on a solid surface"
boundary condition Kelvin-s condition is used to compute the strength
of the latest wake vortex shed from the trailing edge of the airfoil.
Location of the wake vortices is updated at each time-step to get the
wake shape at each time instant. Results are presented to show the
effect of airfoil-airfoil interaction and airfoil-wake interaction on the
aerodynamic characteristics of each airfoil.
Abstract: The purpose of this paper is to summarize the
following protection of scouring countermeasures by using
Bentonite-Enhanced Sand (BES) mixtures. The concept of
underground improvement is being used in this study to reduce the
void of the sand. The sand bentonite mixture was used to bond the
ground soil conditions surrounding the pile of integral bridge. The
right composition of sand bentonite mixture was proposed based on
previous findings. The swelling effect of bentonite also was
investigated to ensure there is no adverse impact to the structure of
the integral bridge. ScourScour, another name for severe erosion,
occurs when the erosive capacity of water resulting from natural and
manmade events exceeds the ability of earth materials to resist its
effects. According to AASHTO LRFD Specifications (Section
C3.7.5), scour is the most common reason for the collapse of
highway bridges in the United States
Abstract: Background Contact lens (CL) wear can cause
changes in blinking and corneal staining. Aims and Objectives To
determine the effects of CL materials (HEMA and SiHy) on
spontaneous blink rate, blinking patterns and corneal staining after 2
months of wear. Methods Ninety subjects in 3 groups (control,
HEMA and SiHy) were assessed at baseline and 2-months. Blink rate
was recorded using a video camera. Blinking patterns were assessed
with digital camera and slit lamp biomicroscope. Corneal staining
was graded using IER grading scale Results There were no significant
differences in all parameters at baseline. At 2 months, CL wearers
showed significant increment in average blink rate (F1.626, 47.141 =
7.250, p = 0.003; F2,58 = 6.240, p = 0.004) and corneal staining (χ2
2,
n=30 = 31.921, p < 0.001; χ2
2, n=30 = 26.909, p < 0.001). Conclusion
Blinking characteristics and corneal staining were not influence by
soft CL materials.
Abstract: This paper propose a new circuit design which
monitor total leakage current during standby mode and generates the
optimal reverse body bias voltage, by using the adaptive body bias
(ABB) technique to compensate die-to-die parameter variations.
Design details of power monitor are examined using simulation
framework in 65nm and 32nm BTPM model CMOS process.
Experimental results show the overhead of proposed circuit in terms
of its power consumption is about 10 μW for 32nm technology and
about 12 μW for 65nm technology at the same power supply voltage
as the core power supply. Moreover the results show that our
proposed circuit design is not far sensitive to the temperature
variations and also process variations. Besides, uses the simple
blocks which offer good sensitivity, high speed, the continuously
feedback loop.
Abstract: Regarding to the fast growth of computer, internet, and virtual learning in our country (Iran) and need computer-based learning systems and multimedia tools as an essential part of such education, designing and implementing such systems would help teach different field such as science. This paper describes the basic principle of multimedia. At the end, with a description of learning science to the infant students, the method of this system will be explained.
Abstract: Aeration by a plunging water jet is an energetically attractive way to effect oxygen-transfer than conventional oxygenation systems. In the present study, a new type of conical shaped plunging aeration device is fabricated to generate hollow inclined ined plunging jets (jet plunge angle of π/3 ) to investigate its oxygen transfer capacity. The results suggest that the volumetric oxygen-transfer coefficient and oxygen-transfer efficiency of the conical plunging jet aerator are competitive with other types of aeration systems. Relationships of volumetric oxygen-transfer coefficient with jet power per unit volume and jet parameters are also proposed. The suggested relationships predict the volumetric oxygentransfer coefficient within a scatter of ± 15% . Further, the application of Support Vector Machines on the experimental data revealed its utility in the prediction of volumetric oxygen-transfer coefficient and development of conical plunging jet aerators.
Abstract: We have modeled the effect of a graded band gap
window on the performance of a single junction AlxGa1-xAs/GaAs
solar cell. First, we study the electrical characteristics of a single
junction AlxGa1-xAs/GaAs solar cell, by employing an optimized
structure for this solar cell, we show that grading the band gap of the
window can increase the conversion efficiency of the solar cell by
about 1.5%, and can also improve the quantum efficiency of the solar
cell especially at shorter wavelengths.
Abstract: Ambient hydrolysis products in moist air and
hydrolysis kinetics in argon with humidity of RH1.5% for
polycrystalline LiH powders and sintered bulks were investigated by
X-ray diffraction, Raman spectroscopy and gravimetry. The results
showed that the hydrolysis products made up a layered structure of
LiOH•H2O/LiOH/Li2O from surface of the sample to inside. In low
humid argon atmosphere, the primary hydrolysis product was Li2O
rather than LiOH. The hydrolysis kinetic curves of LiH bulks present a
paralinear shape, which could be explained by the “Layer Diffusion
Control" model. While a three-stage hydrolysis kinetic profile was
observed for LiH powders under the same experimental conditions.
The first two sections were similar to that of the bulk samples, and the
third section also presents a linear reaction kinetics but with a smaller
reaction rate compared to the second section because of a larger
exothermic effect for the hydrolysis reaction of LiH powder.
Abstract: MicroRNAs are an important class of gene expression
regulators that are involved in many biological processes including
embryogenesis. miR-125b is a conserved microRNA that is enriched
in the nervous system. We have previously reported the function of
miR-125b in neuronal differentiation of human cell lines. We also
discovered the function of miR-125b in regulating p53 in human and
zebrafish. Here we further characterize the brain defects in zebrafish
embryos injected with morpholinos against miR-125b. Our data
confirm the essential role of miR-125b in brain morphogenesis
particularly in maintaining the balance between proliferation, cell
death and differentiation. We identified lunatic fringe (lfng) as an
additional target of miR-125b in human and zebrafish and suggest
that lfng may mediate the function of miR-125b in neurogenesis.
Together, this report reveals new insights into the function of miR-
125b during neural development of zebrafish.
Abstract: The present paper deals with problems related to the
possibilities to use fractal systems to solve some important scientific
and practical problems connected with filtering and separation of
aqueous phases from organic ones. For this purpose a special
separator have been designed. The reactor was filled with a porous
material with fractal dimension, which is an integral part of the set
for filtration and separation of emulsions. As a model emulsion
hexadecan mixture with water in equal quantities (1:1) was used. We
examined the hydrodynamics of the separation of the emulsion at
different rates of submission of the entrance of the reactor.
Abstract: From the perspective of system of systems (SoS) and
emergent behaviors, this paper describes large scale application
software systems, and proposes framework methods to further depict
systems- functional and non-functional characteristics. Besides, this
paper also specifically discusses some functional frameworks. In the
end, the framework-s applications in system disintegrations, system
architecture and stable intermediate forms are additionally dealt with
in this in building, deployment and maintenance of large scale
software applications.
Abstract: Visual secret sharing (VSS) was proposed by Naor and Shamir in 1995. Visual secret sharing schemes encode a secret image into two or more share images, and single share image can’t obtain any information about the secret image. When superimposes the shares, it can restore the secret by human vision. Due to the traditional VSS have some problems like pixel expansion and the cost of sophisticated. And this method only can encode one secret image. The schemes of encrypting more secret images by random grids into two shares were proposed by Chen et al. in 2008. But when those restored secret images have much distortion, those schemes are almost limited in decoding. In the other words, if there is too much distortion, we can’t encrypt too much information. So, if we can adjust distortion to very small, we can encrypt more secret images. In this paper, four new algorithms which based on Chang et al.’s scheme be held in 2010 are proposed. First algorithm can adjust distortion to very small. Second algorithm distributes the distortion into two restored secret images. Third algorithm achieves no distortion for special secret images. Fourth algorithm encrypts three secret images, which not only retain the advantage of VSS but also improve on the problems of decoding.
Abstract: Synthetic aperture radar (SAR) imaging usually
requires echo data collected continuously pulse by pulse with certain
bandwidth. However in real situation, data collection or part of signal
spectrum can be interrupted due to various reasons, i.e. there will be
gaps in spatial spectrum. In this case we need to find ways to fill out
the resulted gaps and get image with defined resolution. In this paper
we introduce our work on how to apply iterative spatially variant
apodization (Super-SVA) technique to extrapolate the spatial
spectrum in both azimuthal and range directions so as to fill out the
gaps and get correct radar image.
Abstract: The paper deals with the analysis of the dynamic
response of footbridges under human - induced dynamic loads.
This is a frequently occurring and often dominant load for
footbridges as it stems from the very purpose of a footbridge - to
convey pedestrian. Due to the emergence of new materials and
advanced engineering technology, slender footbridges are
increasingly becoming popular to satisfy the modern transportation
needs and the aesthetical requirements of the society. These
structures however are always lively with low stiffness, low mass,
low damping and low natural frequencies. As a consequence, they are
prone to vibration induced by human activities and can suffer severe
vibration serviceability problems, particularly in the lateral direction.
Pedestrian bridges are designed according to first and second limit
states, these are the criteria involved in response to static design load.
However, it is necessary to assess the dynamic response of bridge
design load on pedestrians and assess it impact on the comfort of the
user movement. Usually the load is considered a person or a small
group which can be assumed in perfect motion synchronization.
Already one person or small group can excite significant vibration of
the deck. In order to calculate the dynamic response to the movement
of people, designer needs available and suitable computational model
and criteria. For the calculation program ANSYS based on finite
element method was used.
Abstract: Practices of food sharing as part of the brotherhood and hospitality interpretation have been essential part of the Kazakh ethnic culture since early times. Dialogue in time and space between Kazakhs through differences in food interpretation among the ethnic repatriates may become a link connecting them and platform for stable relations with the host society or serious barrier on the way of their integration in the Kazakhstani society. The article elucidates by the field materials how some aspects of food culture differences among ethnic Kazakhs living abroad (XUAR of China) and ethnic repatriates in Kazakhstan may influence their integration path.
Abstract: Multiple-Input-Multiple-Output (MIMO) is one of the most important communication techniques that allow wireless systems to achieve higher data rate. To overcome the practical difficulties in implementing Dirty Paper Coding (DPC), various suboptimal MIMO Broadcast (MIMO-BC) scheduling algorithms are employed which choose the best set of users among all the users. In this paper we discuss such a sub-optimal MIMO-BC scheduling algorithm which employs antenna selection at the receiver side. The channels for the users considered here are not Identical and Independent Distributed (IID) so that users at the receiver side do not get equal opportunity for communication. So we introduce a method of applying weights to channels of the users which are not IID in such a way that each of the users gets equal opportunity for communication. The effect of weights on overall sum-rate achieved by the system has been investigated and presented.
Abstract: The authors present an optimization algorithm for order reduction and its application for the determination of the relative mapping errors of linear time invariant dynamic systems by the simplified models. These relative mapping errors are expressed by means of the relative integral square error criterion, which are determined for both unit step and impulse inputs. The reduction algorithm is based on minimization of the integral square error by particle swarm optimization technique pertaining to a unit step input. The algorithm is simple and computer oriented. It is shown that the algorithm has several advantages, e.g. the reduced order models retain the steady-state value and stability of the original system. Two numerical examples are solved to illustrate the superiority of the algorithm over some existing methods.
Abstract: Recent scientific investigations indicate that
multimodal biometrics overcome the technical limitations of
unimodal biometrics, making them ideally suited for everyday life
applications that require a reliable authentication system. However,
for a successful adoption of multimodal biometrics, such systems
would require large heterogeneous datasets with complex multimodal
fusion and privacy schemes spanning various distributed
environments. From experimental investigations of current
multimodal systems, this paper reports the various issues related to
speed, error-recovery and privacy that impede the diffusion of such
systems in real-life. This calls for a robust mechanism that caters to
the desired real-time performance, robust fusion schemes,
interoperability and adaptable privacy policies.
The main objective of this paper is to present a framework that
addresses the abovementioned issues by leveraging on the
heterogeneous resource sharing capacities of Grid services and the
efficient machine learning capabilities of artificial neural networks
(ANN). Hence, this paper proposes a Grid-based neural network
framework for adopting multimodal biometrics with the view of
overcoming the barriers of performance, privacy and risk issues that
are associated with shared heterogeneous multimodal data centres.
The framework combines the concept of Grid services for reliable
brokering and privacy policy management of shared biometric
resources along with a momentum back propagation ANN (MBPANN)
model of machine learning for efficient multimodal fusion and
authentication schemes. Real-life applications would be able to adopt
the proposed framework to cater to the varying business requirements
and user privacies for a successful diffusion of multimodal
biometrics in various day-to-day transactions.
Abstract: In this article, a single application is suggested to determine the position of vehicles using Geographical Information Systems (GIS) and Geographical Position Systems (GPS). The part of the article material included mapping three dimensional coordinates to two dimensional coordinates using UTM or LAMBERT geographical methods, and the algorithm of conversion of GPS information into GIS maps is studied. Also, suggestions are given in order to implement this system based on web (called web based systems). To apply this system in IRAN, related official in this case are introduced and their duties are explained. Finally, economy analyzed is assisted according to IRAN communicational system.