Abstract: A method based on the power series solution is proposed to solve the natural frequency of flapping vibration for the rotating inclined Euler beam with constant angular velocity. The vibration of the rotating beam is measured from the position of the corresponding steady state axial deformation. In this paper the governing equations for linear vibration of a rotating Euler beam are derived by the d'Alembert principle, the virtual work principle and the consistent linearization of the fully geometrically nonlinear beam theory in a rotating coordinate system. The governing equation for flapping vibration of the rotating inclined Euler beam is linear ordinary differential equation with variable coefficients and is solved by a power series with four independent coefficients. Substituting the power series solution into the corresponding boundary conditions at two end nodes of the rotating beam, a set of homogeneous equations can be obtained. The natural frequencies may be determined by solving the homogeneous equations using the bisection method. Numerical examples are studied to investigate the effect of inclination angle on the natural frequency of flapping vibration for rotating inclined Euler beams with different angular velocity and slenderness ratio.
Abstract: This paper presents a low-voltage low-power differential linear transconductor with near rail-to-rail input swing. Based on the current-mirror OTA topology, the proposed transconductor combines the Flipped Voltage Follower (FVF) technique to linearize the transconductor behavior that leads to class- AB linear operation and the virtual transistor technique to lower the effective threshold voltages of the transistors which offers an advantage in terms of low supply requirement. Design of the OTA has been discussed. It operates at supply voltages of about ±0.8V. Simulation results for 0.18μm TSMC CMOS technology show a good input range of 1Vpp with a high DC gain of 81.53dB and a total harmonic distortion of -40dB at 1MHz for an input of 1Vpp. The main aim of this paper is to present and compare new OTA design with high transconductance, which has a potential to be used in low voltage applications.
Abstract: Key management is a vital component in any modern security protocol. Due to scalability and practical implementation considerations automatic key management seems a natural choice in significantly large virtual private networks (VPNs). In this context IETF Internet Key Exchange (IKE) is the most promising protocol under permanent review. We have made a humble effort to pinpoint IKEv2 net gain over IKEv1 due to recent modifications in its original structure, along with a brief overview of salient improvements between the two versions. We have used US National Institute of Technology NIIST VPN simulator to get some comparisons of important performance metrics.
Abstract: Grid computing provides a virtual framework for
controlled sharing of resources across institutional boundaries.
Recently, trust has been recognised as an important factor for
selection of optimal resources in a grid. We introduce a new method
that provides a quantitative trust value, based on the past interactions
and present environment characteristics. This quantitative trust value
is used to select a suitable resource for a job and eliminates run time
failures arising from incompatible user-resource pairs. The proposed
work will act as a tool to calculate the trust values of the various
components of the grid and there by improves the success rate of the
jobs submitted to the resource on the grid. The access to a resource
not only depend on the identity and behaviour of the resource but
also upon its context of transaction, time of transaction, connectivity
bandwidth, availability of the resource and load on the resource. The
quality of the recommender is also evaluated based on the accuracy
of the feedback provided about a resource. The jobs are submitted for
execution to the selected resource after finding the overall trust value
of the resource. The overall trust value is computed with respect to
the subjective and objective parameters.
Abstract: Educational institutions are increasingly exploring the affordances of 3D virtual worlds for instruction and research, but few studies have been done to document current practices and uses of this emerging technology. This observational survey examines the virtual presences of 170 accredited educational institutions found in one such 3D virtual world called Second Life®, created by San- Francisco based Linden Lab®. The study focuses on what educational institutions look like in this virtual environment, the types of spaces educational institutions are creating or simulating, and what types of activities are being conducted.
Abstract: The purpose of this study is to design a portable virtual
piano. By utilizing optical fiber gloves and the virtual piano software
designed by this study, the user can play the piano anywhere at any
time. This virtual piano consists of three major parts: finger tapping
identification, hand movement and positioning identification, and
MIDI software sound effect simulation. To play the virtual piano, the
user wears optical fiber gloves and simulates piano key tapping
motions. The finger bending information detected by the optical fiber
gloves can tell when piano key tapping motions are made. Images
captured by a video camera are analyzed, hand locations and moving
directions are positioned, and the corresponding scales are found. The
system integrates finger tapping identification with information about
hand placement in relation to corresponding piano key positions, and
generates MIDI piano sound effects based on this data. This
experiment shows that the proposed method achieves an accuracy rate
of 95% for determining when a piano key is tapped.
Abstract: The increase on the demand of IT resources diverts
the enterprises to use the cloud as a cheap and scalable solution.
Cloud computing promises achieved by using the virtual machine as a
basic unite of computation. However, the virtual machine pre-defined
settings might be not enough to handle jobs QoS requirements. This
paper addresses the problem of mapping jobs have critical start
deadlines to virtual machines that have predefined specifications.
These virtual machines hosted by physical machines and shared a
fixed amount of bandwidth. This paper proposed an algorithm that
uses the idle virtual machines bandwidth to increase the quote of other
virtual machines nominated as executors to urgent jobs. An algorithm
with empirical study have been given to evaluate the impact of the
proposed model on impatient jobs. The results show the importance
of dynamic bandwidth allocation in virtualized environment and its
affect on throughput metric.
Abstract: This paper discusses about an intelligent system to be
installed in ambulances providing professional support to the paramedics on board. A video conferencing device over mobile 4G services enables specialists virtually attending the patient being transferred to the hospital. The data centre holds detailed databases
on the patients past medical history and hospitals with the specialists. It also hosts various software modules that compute the shortest traffic –less path to the closest hospital with the required facilities, on inputting the symptoms of the patient, on a real time basis.
Abstract: A virtualized and virtual approach is presented on
academically preparing students to successfully engage at a strategic
perspective to understand those concerns and measures that are both
structured and not structured in the area of cyber security and
information assurance. The Master of Science in Cyber Security and
Information Assurance (MSCSIA) is a professional degree for those
who endeavor through technical and managerial measures to ensure
the security, confidentiality, integrity, authenticity, control,
availability and utility of the world-s computing and information
systems infrastructure. The National University Cyber Security and
Information Assurance program is offered as a Master-s degree. The
emphasis of the MSCSIA program uniquely includes hands-on
academic instruction using virtual computers. This past year, 2011,
the NU facility has become fully operational using system
architecture to provide a Virtual Education Laboratory (VEL)
accessible to both onsite and online students. The first student cohort
completed their MSCSIA training this past March 2, 2012 after
fulfilling 12 courses, for a total of 54 units of college credits. The
rapid pace scheduling of one course per month is immensely
challenging, perpetually changing, and virtually multifaceted. This
paper analyses these descriptive terms in consideration of those
globalization penetration breaches as present in today-s world of
cyber security. In addition, we present current NU practices to
mitigate risks.
Abstract: In Virtual organization, Knowledge Discovery (KD)
service contains distributed data resources and computing grid nodes.
Computational grid is integrated with data grid to form Knowledge
Grid, which implements Apriori algorithm for mining association
rule on grid network. This paper describes development of parallel
and distributed version of Apriori algorithm on Globus Toolkit using
Message Passing Interface extended with Grid Services (MPICHG2).
The creation of Knowledge Grid on top of data and
computational grid is to support decision making in real time
applications. In this paper, the case study describes design and
implementation of local and global mining of frequent item sets. The
experiments were conducted on different configurations of grid
network and computation time was recorded for each operation. We
analyzed our result with various grid configurations and it shows
speedup of computation time is almost superlinear.
Abstract: Within dental-guided surgery, there has been a lack
of analytical methods for optimizing the treatment of the
rehabilitation concepts regarding geometrical variation. The purpose
of this study is to find the source of the greatest geometrical variation
contributor and sensitivity contributor with the help of virtual
variation simulation of a dental drill- and implant-guided surgery
process using a methodical approach. It is believed that lower
geometrical variation will lead to better patient security and higher
quality of dental drill- and implant-guided surgeries. It was found
that the origin of the greatest contributor to the most variation, and
hence where the foci should be set, in order to minimize geometrical
variation was in the assembly category (surgery). This was also the
category that was the most sensitive for geometrical variation.
Abstract: Many studies have emphasized the importance of
resistive exercise to maintain a healthy human body, particular in
prevention of weakening of physical strength. Recently, some studies
advocated that an application of vibration as a supplementary means in
a regular training was effective in encouraging physical strength. Aim
of the current study was, therefore, to identify if an application of
vibration in a resistive exercise was effective in encouraging physical
strength as that in a regular training. A 3-dimensional virtual lower
extremity model for a healthy male and virtual leg-press model were
generated and synchronized. Dynamic leg-press exercises on a slide
machine with/without extra load and on a footboard with vibration as
well as on a slide machine with extra load were analyzed. The results
of the current indicated that the application of the vibration on the
dynamic leg-press exercise might be not greatly effective in
encouraging physical strength, compared with the dynamic leg press
exercise with extra load. It was, however, thought that the application
of the vibration might be helpful to elderly individuals because the
reduced maximum muscle strength appeared by the effect of the
vibration may avoid a muscular spasm, which can be driven from a
high muscle strength sometimes produced during the leg-press
exercise with extra load.
Abstract: Ecological ponds can be a good teaching tool for
science teachers, but they must be built and maintained properly to
provide students with a safe and suitable learning environment.
Hence, many schools do not have the ability to build an ecological
pond. This study used virtual reality technology to develop a webbased
virtual ecological pond. Supported by situated learning theory
and the instructional design of “Aquatic Life" learning unit,
elementary school students can actively explore in the virtual
ecological pond to observe aquatic animals and plants and learn
about the concept of ecological conservation. A teaching experiment
was conducted to investigate the learning effectiveness and
practicability of this instructional design, and the results showed that
students improved a great deal in learning about aquatic life. They
found the virtual ecological pond interesting, easy to operate and
helpful to understanding the aquatic ecological system. Therefore, it
is useful in elementary science education.
Abstract: Internet access is a vital part of the modern world and an important tool in the education of our children. It is present in schools, homes and even shopping malls. Mastering the use of the internet is likely to be an important skill for those entering the job markets of the future. An internet user can be anyone he or she wants to be in an online chat room, or play thrilling and challenging games against other players from all corners of the globe. It seems at present time (or near future) for many people relationships in the real world may be neglected as those in the virtual world increase in importance. Internet is provided a fast mode of transportation caused freedom from family bonds and mixing with different cultures and new communities. This research is an attempt to study effect of Internet on Social capital. For this purpose a survey technique on the sample size amounted 168 students of Payame Noor University of Kermanshah city in country of Iran were considered. Degree of social capital is moderate. With the help of the Multi-variable Regression, variables of Iranian message attractive, Interest to internet with effect of positive and variable Creating a cordial atmosphere with negative effect be significant.
Abstract: The explosion of interest in online gaming and
virtual worlds is leading many universities to investigate
possible educational applications of the new environments.
In this paper we explore the possibilities of 3D online worlds
for teacher education, particularly the field experience
component. Drawing upon two pedagogical examples, we
suggest that virtual simulations may, with certain limitations,
create safe spaces that allow preservice teachers to adopt
alternate identities and interact safely with the “other." In so
doing they may become aware of the constructed nature of
social categories and gain the essential pedagogical skill of
perspective-taking. We suggest that, ultimately, the ability to
be the principal creators of themselves in virtual environments
can increase their ability to do the same in the real world.
Abstract: Determining how many virtual machines a Linux host
could run can be a challenge. One of tough missions is to find the
balance among performance, density and usability. Now KVM
hypervisor has become the most popular open source full
virtualization solution. It supports several ways of running guests with
more memory than host really has. Due to large differences between
minimum and maximum guest memory requirements, this paper
presents initial results on same-page merging, ballooning and live
migration techniques that aims at optimum memory usage on
KVM-based cloud platform. Given the design of initial experiments,
the results data is worth reference for system administrators. The
results from these experiments concluded that each method offers
different reliability tradeoff.
Abstract: The use of 3D computer-aided design (CAD) models
to support construction project planning has been increasing in the
previous year. 3D CAD models reveal more planning ideas by
visually showing the construction site environment in different stages
of the construction process. Using 3D CAD models together with
scheduling software to prepare construction plan can identify errors
in process sequence and spatial arrangement, which is vital to the
success of a construction project. A number of 4D (3D plus time)
CAD tools has been developed and utilized in different construction
projects due to the awareness of their importance. Virtual prototyping
extends the idea of 4D CAD by integrating more features for
simulating real construction process. Virtual prototyping originates
from the manufacturing industry where production of products such
as cars and airplanes are virtually simulated in computer before they
are built in the factory. Virtual prototyping integrates 3D CAD,
simulation engine, analysis tools (like structural analysis and
collision detection), and knowledgebase to streamline the whole
product design and production process. In this paper, we present the
application of a virtual prototyping software which has been used in
a few construction projects in Hong Kong to support construction
project planning. Specifically, the paper presents an implementation
of virtual prototyping in a residential building project in Hong Kong.
The applicability, difficulties and benefits of construction virtual
prototyping are examined based on this project.
Abstract: This communication is intended to provide some issues for thought on the importance of implementation of Blended Learning in traditional universities, particularly in the Spanish university system. In this respect, we believe that virtual environments are likely to meet some of the needs raised by the Bologna agreement, trying to maintain the quality of teaching and at the same time taking advantage of the functionalities that virtual learning platforms offer. We are aware that an approach of learning from an open and constructivist nature in universities is a complex process that faces significant technological, administrative and human barriers. Therefore, in order to put plans in our universities, it is necessary to analyze the state of the art of some indicators relating to the use of ICT, with special attention to virtual teaching and learning, so that we can identify the main obstacles and design adaptive strategies for their full integration in the education system. Finally, we present major initiatives launched in the European and state framework for the effective implementation of new virtual environments in the area of higher education.
Abstract: The paper presents a novel method for the 3D shaping
of different materials using a high-pressure abrasive water jet and a
flat target image. For steering movement process of the jet a principle
similar to raster image way of record and readout was used.
However, respective colors of pixel of such a bitmap are connected
with adequate jet feed rate that causes erosion of material with
adequate depth. Thanks to that innovation, one can observe spatial
imaging of the object. Theoretical basis as well as spatial model of
material shaping and experimental stand including steering program
are presented in. There are also presented methodic and some
experimental erosion results as well as practical example of object-s
bas-relief made of metal.
Abstract: Computer-mediated communication technologies which provide for virtual communities have typically evolved in a cross-dichotomous manner, such that technical constructs of the technology have evolved independently from the social environment of the community. The present paper analyses some limitations of current implementations of computer-mediated communication technology that are implied by such a dichotomy, and discusses their inhibiting effects on possible developments of virtual communities. A Socio-Technical Indicator Model is introduced that utilizes integrated feedback to describe, simulate and operationalise increasing representativeness within a variety of structurally and parametrically diverse systems. In illustration, applications of the model are briefly described for financial markets and for eco-systems. A detailed application is then provided to resolve the aforementioned technical limitations of moderation on the evolution of virtual communities. The application parameterises virtual communities to function as self-transforming social-technical systems which are sensitive to emergent and shifting community values as products of on-going communications within the collective.