Abstract: Multirate multimedia delivery applications in multihop Wireless Mesh Network (WMN) are data redundant and delay-sensitive, which brings a lot of challenges for designing efficient transmission systems. In this paper, we propose a new cross layer resource allocation scheme to minimize the receiver side distortion within the delay bound requirements, by exploring application layer Position and Value (P-V) diversity as well as the multihop Effective Capacity (EC). We specifically consider image transmission optimization here. First of all, the maximum supportable source traffic rate is identified by exploring the multihop Effective Capacity (EC) model. Furthermore, the optimal source coding rate is selected according to the P-V diversity of multirate media streaming, which significantly increases the decoded media quality. Simulation results show the proposed approach improved media quality significantly compared with traditional approaches under the same QoS requirements.
Abstract: This paper explores the implementation of adaptive
coding and modulation schemes for Multiple-Input Multiple-Output
Orthogonal Frequency Division Multiplexing (MIMO-OFDM) feedback
systems. Adaptive coding and modulation enables robust and
spectrally-efficient transmission over time-varying channels. The basic
premise is to estimate the channel at the receiver and feed this estimate
back to the transmitter, so that the transmission scheme can be
adapted relative to the channel characteristics. Two types of codebook
based channel feedback techniques are used in this work. The longterm
and short-term CSI at the transmitter is used for efficient channel
utilization. OFDM is a powerful technique employed in communication
systems suffering from frequency selectivity. Combined with
multiple antennas at the transmitter and receiver, OFDM proves to be
robust against delay spread. Moreover, it leads to significant data rates
with improved bit error performance over links having only a single
antenna at both the transmitter and receiver. The coded modulation
increases the effective transmit power relative to uncoded variablerate
variable-power MQAM performance for MIMO-OFDM feedback
system. Hence proposed arrangement becomes an attractive approach
to achieve enhanced spectral efficiency and improved error rate
performance for next generation high speed wireless communication
systems.
Abstract: Science parks are often established to drive regional
economic growth, especially in countries with emerging economies.
However, mixed findings regarding the performances of science park
firms are found in the literature. This study tries to explain these
mixed findings by taking a relational approach and exploring
(un)intended knowledge transfers between new technology-based
firms (NTBFs) in the emerging South African economy. Moreover,
the innovation outcomes of these NTBFs are examined by using a
multi-dimensional construct. Results show that science park location
plays a significant role in explaining innovative sales, but is
insignificant when a different indicator of innovation outcomes is
used. Furthermore, only for innovations that are new to the firms,
both science park location and intended knowledge transfer via
informal business relationships have a positive impact; whereas
social relationships have a negative impact.
Abstract: Mobile Learning (M-Learning) is a new technology
which is to enhance current learning practices and activities for all
people especially students and academic practitioners UTP is
currently, implemented two types of learning styles which are
conventional and electronic learning. In order to improve current
learning approaches, it is necessary for UTP to implement m-learning
in UTP. This paper presents a study on the students- perceptions on
mobile utilization in the learning practices in UTP. Besides, this
paper also presents a survey that was conducted among 82 students
from System Analysis and Design (SAD) course in UTP. The survey
includes basic information of mobile devices that have been used by
the students, opinions on current learning practices and also the
opinions regarding the m-learning implementation in the current
learning practices especially in SAD course. Based on the results of
the survey, majority of the students are using the mobile devices that
can support m-learning environment. Other than that, students also
agreed that current learning practices are ineffective and they believe
that m-learning utilization can improve the effectiveness of current
learning practices.
Abstract: Charging and discharging phenomenon on the surface
of materials can be found in plasma display panel, spacecraft
charging, high voltage insulator, etc. This report gives a simple
explanation on this phenomenon. A scanning electron microscope
was used not only as a tool to produce energetic electron beam to
charge an insulator without metallic coating and to produce a surface
discharging (surface breakdown/flashover) but also to observe the
visible charging and discharging on the sample surface. A model of
electric field distribution on the surface was developed in order to
explain charging and discharging phenomena. Since charging and
discharging process involves incubation time, therefore this process
can be used to evaluate the insulation property of materials under
electron bombardment.
Abstract: Since IEC61850 substation communication standard represents the trend to develop new generations of Substation Automation System (SAS), many IED manufacturers pursue this technique and apply for KEMA. In order to put on the market to meet customer demand as fast as possible, manufacturers often apply their products only for basic environment standard certification but claim to conform to IEC61850 certification. Since verification institutes generally perform verification tests only on specific IEDs of the manufacturers, the interoperability between all certified IEDs cannot be guaranteed. Therefore the interoperability between IEDs from different manufacturers needs to be tested. Based upon the above reasons, this study applies the definitions of the information models, communication service, GOOSE functionality and Substation Configuration Language (SCL) of the IEC61850 to build the concept of communication protocols, and build the test environment. The procedures of the test of the data collection and exchange of the P2P communication mode and Client / Server communication mode in IEC61850 are outlined as follows. First, test the IED GOOSE messages communication capability from different manufacturers. Second, collect IED data from each IED with SCADA system and use HMI to display the SCADA platform. Finally, problems generally encountered in the test procedure are summarized.
Abstract: A number of previous studies were rarely considered
the effects of transient non-uniform balloon expansion on evaluation
of the properties and behaviors of stents during stent expansion, nor
did they determine parameters to maximize the performances driven
by mechanical characteristics. Therefore, in order to fully understand
the mechanical characteristics and behaviors of stent, it is necessary to
consider a realistic modeling of transient non-uniform balloon-stent
expansion. The aim of the study is to propose design parameters
capable of improving the ability of vascular stent through a
comparative study of seven commercial stents using finite element
analyses of a realistic transient non-uniform balloon-stent expansion
process. In this study, seven representative commercialized stents were
evaluated by finite element (FE) analysis in terms of the criteria based
on the itemized list of Food and Drug Administration (FDA) and
European Standards (prEN). The results indicate that using stents
composed of opened unit cells connected by bend-shaped link
structures and controlling the geometrical and morphological features
of the unit cell strut or the link structure at the distal ends of stent may
improve mechanical characteristics of stent. This study provides a
better method at the realistic transient non-uniform balloon-stent
expansion by investigating the characteristics, behaviors, and
parameters capable of improving the ability of vascular stent.
Abstract: Music segmentation is a key issue in music information
retrieval (MIR) as it provides an insight into the
internal structure of a composition. Structural information about
a composition can improve several tasks related to MIR such
as searching and browsing large music collections, visualizing
musical structure, lyric alignment, and music summarization.
The authors of this paper present the MTSSM framework, a twolayer
framework for the multi-track segmentation of symbolic
music. The strength of this framework lies in the combination of
existing methods for local track segmentation and the application
of global structure information spanning via multiple tracks.
The first layer of the MTSSM uses various string matching
techniques to detect the best candidate segmentations for each
track of a multi-track composition independently. The second
layer combines all single track results and determines the best
segmentation for each track in respect to the global structure of
the composition.
Abstract: Bubble columns have a variety of applications in
absorption, bio-reactions, catalytic slurry reactions, and coal
liquefaction; because they are simple to operate, provide good heat
and mass transfer, having less operational cost. The use of
Computational Fluid Dynamics (CFD) for bubble column becomes
important, since it can describe the fluid hydrodynamics on both local
and global scale. Euler- Euler two-phase fluid model has been used to
simulate two-phase (air and water) transient up-flow in bubble
column (15cm diameter) using FLUENT6.3. These simulations and
experiments were operated over a range of superficial gas velocities
in the bubbly flow and churn turbulent regime (1 to16 cm/s) at
ambient conditions. Liquid velocity was varied from 0 to 16cm/s. The
turbulence in the liquid phase is described using the standard k-ε
model. The interactions between the two phases are described
through drag coefficient formulations (Schiller Neumann). The
objectives are to validate CFD simulations with experimental data,
and to obtain grid-independent numerical solutions. Quantitatively
good agreements are obtained between experimental data for hold-up
and simulation values. Axial liquid velocity profiles and gas holdup
profiles were also obtained for the simulation.
Abstract: Thermal conductivity is an important characteristic of
a nanofluid in laminar flow heat transfer. This paper presents an
improved model for the prediction of the effective thermal
conductivity of nanofluids based on dimensionless groups. The
model expresses the thermal conductivity of a nanofluid as a function
of the thermal conductivity of the solid and liquid, their volume
fractions and particle size. The proposed model includes a parameter
which accounts for the interfacial shell, brownian motion, and
aggregation of particle. The validation of the model is verified by
applying the results obtained by the experiments of Tio2-water and
Al2o3-water nanofluids.
Abstract: Fossil fuel-firing power plants dominate electric
power generation in Taiwan, which are also the major contributor to
Green House gases (GHG). CO2 is the most important greenhouse
gas that cause global warming. This paper penetrates the relationship
between carbon trading for GHG reduction and power generation
expansion planning (GEP) problem for the electrical utility. The
Particle Swarm Optimization (PSO) Algorithm is presented to deal
with the generation expansion planning strategy of the utility with
independent power providers (IPPs). The utility has to take both the
IPPs- participation and environment impact into account when a new
generation unit is considering expanded from view of supply side.
Abstract: In this paper, the potential security issues brought by the virtualization of a Software Defined Networks (SDN) would be analyzed. The virtualization of SDN is achieved by FlowVisor (FV). With FV, a physical network is divided into multiple isolated logical networks while the underlying resources are still shared by different slices (isolated logical networks). However, along with the benefits brought by network virtualization, it also presents some issues regarding security. By examining security issues existing in an OpenFlow network, which uses FlowVisor to slice it into multiple virtual networks, we hope we can get some significant results and also can get furtherdiscussions among the security of SDN virtualization.
Abstract: This article gives a short preview of the new software
created especially for palletizing process in automated production
systems. Each chapter of this article is about problem solving in
development of modules in Java programming language. First part
describes structure of the software, its modules and data flow
between them. Second part describes all deployment methods, which
are implemented in the software. Next chapter is about twodimensional
editor created for manipulation with objects in each
layer of the load and gives calculations for collision control. Module
of virtual reality used for three-dimensional preview and creation of
the load is described in the fifth chapter. The last part of this article
describes communication and data flow between control system of
the robot, vision system and software.
Abstract: The tubes in an Ammonia primary reformer furnace
operate close to the limits of materials technology in terms of the
stress induced as a result of very high temperatures, combined with
large differential pressures across the tube wall. Operation at tube
wall temperatures significantly above design can result in a rapid
increase in the number of tube failures, since tube life is very
sensitive to the absolute operating temperature of the tube. Clearly it
is important to measure tube wall temperatures accurately in order to
prevent premature tube failure by overheating.. In the present study,
the catalyst tubes in an Ammonia primary reformer has been modeled
taking into consideration heat, mass and momentum transfer as well
as reformer characteristics.. The investigations concern the effects of
tube characteristics and superficial tube wall temperatures on of the
percentage of heat flux, unconverted methane and production of
Hydrogen for various values of steam to carbon ratios. The results
show the impact of catalyst tubes length and diameters on the
performance of operating parameters in ammonia primary reformers.
Abstract: A two-parameter fatigue model explicitly accounting for the cyclic as well as the mean stress was used to fit static and fatigue data available in literature concerning carbon fiber reinforced composite laminates subjected tension-tension fatigue. The model confirms the strength–life equal rank assumption and predicts reasonably the probability of failure under cyclic loading. The model parameters were found by best fitting procedures and required a minimum of experimental tests.
Abstract: The springs located in urban areas are the outpouring
of surface water, which can serve as water supply, effluent receptors
and important local macro-drainage elements. With unplanned
occupation, non-compliance with environmental legislation and the
importance of these water bodies, it is vital to analyze the springs
within urban areas, considering the Brazilian forest code. This paper
submits an analysis and discussion methodology proposal of
environmental compliance functions of urban springs, by means of
G.I.S. - Geographic Information System analysis - and in situ
analysis. The case study included two springs which exhibit a history
of occupation along its length, with different degrees of impact. The
proposed method is effective and easy to apply, representing a
powerful tool for analyzing the environmental conditions of springs
in urban areas.
Abstract: In this paper back-propagation artificial neural
network (BPANN) is employed to predict the limiting drawing ratio
(LDR) of the deep drawing process. To prepare a training set for
BPANN, some finite element simulations were carried out. die and
punch radius, die arc radius, friction coefficient, thickness, yield
strength of sheet and strain hardening exponent were used as the
input data and the LDR as the specified output used in the training of
neural network. As a result of the specified parameters, the program
will be able to estimate the LDR for any new given condition.
Comparing FEM and BPANN results, an acceptable correlation was
found.
Abstract: State-of-the-art methods for secondary structure (Porter, Psi-PRED, SAM-T99sec, Sable) and solvent accessibility (Sable, ACCpro) predictions use evolutionary profiles represented by the position specific scoring matrix (PSSM). It has been demonstrated that evolutionary profiles are the most important features in the feature space for these predictions. Unfortunately applying PSSM matrix leads to high dimensional feature spaces that may create problems with parameter optimization and generalization. Several recently published suggested that applying feature extraction for the PSSM matrix may result in improvements in secondary structure predictions. However, none of the top performing methods considered here utilizes dimensionality reduction to improve generalization. In the present study, we used simple and fast methods for features selection (t-statistics, information gain) that allow us to decrease the dimensionality of PSSM matrix by 75% and improve generalization in the case of secondary structure prediction compared to the Sable server.
Abstract: In this study, a vibration analysis was carried out of
symmetric angle-ply laminated composite plates with and without
square hole when subjected to compressive loads, numerically. A
buckling analysis is also performed to determine the buckling load of
laminated plates. For each fibre orientation, the compression load is
taken equal to 50% of the corresponding buckling load. In the
analysis, finite element method (FEM) was applied to perform
parametric studies, the effects of degree of orthotropy and stacking
sequence upon the fundamental frequencies and buckling loads are
discussed. The results show that the presence of a constant
compressive load tends to reduce uniformly the natural frequencies
for materials which have a low degree of orthotropy. However, this
reduction becomes non-uniform for materials with a higher degree of
orthotropy.
Abstract: This paper discusses the approach of real-time
controlling of the energy management system using the data
acquisition tool of LabVIEW. The main idea of this inspiration was
to interface the Station (PC) with the system and publish the data on
internet using LabVIEW. In this venture, controlling and switching of
3 phase AC loads are effectively and efficiently done. The phases are
also sensed through devices. In case of any failure the attached
generator starts functioning automatically. The computer sends
command to the system and system respond to the request. The
modern feature is to access and control the system world-wide using
world wide web (internet). This controlling can be done at any time
from anywhere to effectively use the energy especially in developing
countries where energy management is a big problem. In this system
totally integrated devices are used to operate via remote location.