Abstract: Digital Video Terrestrial Broadcasting (DVB-T)
allows combining broadcasting, telephone and data services in one
network. It has facilitated mobile TV broadcasting. Mobile TV
broadcasting is dominated by fragmentation of standards in use in
different continents. In Asia T-DMB and ISDB-T are used while
Europe uses mainly DVB-H and in USA it is MediaFLO. Issues of
royalty for developers of these different incompatible technologies,
investments made and differing local conditions shall make it
difficult to agree on a unified standard in a very near future. Despite
this shortcoming, mobile TV has shown very good market potential.
There are a number of challenges that still exist for regulators,
investors and technology developers but the future looks bright.
There is need for mobile telephone operators to cooperate with
content providers and those operating terrestrial digital broadcasting
infrastructure for mutual benefit.
Abstract: This paper presents a method for obtaining the
desired reference current for Voltage Source Converter (VSC) of the Shunt Active Power Filter (SAPF) using Synchronous Reference Frame Theory. The method relies on the performance of the Proportional-Integral (PI) controller for
obtaining the best control performance of the SAPF. To
improve the performance of the PI controller, the feedback
path to the integral term is introduced to compensate the
winding up phenomenon due to integrator. Using Reference
Frame Transformation, reference signals are transformed from
a - b - c stationery frame to 0 - d - q rotating frame.
Using the PI controller, the reference signals in the 0 - d - q rotating frame are controlled to get the desired reference signals for the Pulse Width Modulation. The synchronizer, the Phase Locked Loop (PLL) with PI filter is used for
synchronization, with much emphasis on minimizing delays. The system performance is examined with Shunt Active Power Filter simulation model.
Abstract: Lateral-torsional buckling (LTB) is one of the
phenomenae controlling the ultimate bending strength of steel Ibeams
carrying distributed loads on top flange. Built-up I-sections
are used as main beams and distributors. This study investigates the
ultimate bending strength of such beams with sections of different
classes including slender elements. The nominal strengths of the
selected beams are calculated for different unsupported lengths
according to the Provisions of the American Institute of Steel
Constructions (AISC-LRFD). These calculations are compared with
results of a nonlinear inelastic study using accurate FE model for this
type of loading. The goal is to investigate the performance of the
provisions for the selected sections. Continuous distributed load at
the top flange of the beams was applied at the FE model.
Imperfections of different values are implemented to the FE model to
examine their effect on the LTB of beams at failure, and hence, their
effect on the ultimate strength of beams. The study also introduces a
procedure for evaluating the performance of the provisions compared
with the accurate FEA results of the selected sections. A simplified
design procedure is given and recommendations for future code
updates are made.
Abstract: Atherosclerosis is the condition in which an artery
wall thickens as the result of a build-up of fatty materials such as
cholesterol. It is a syndrome affecting arterial blood vessels, a
chronic inflammatory response in the walls of arteries, in large part
due to the accumulation of macrophage white blood cells and
promoted by low density (especially small particle) lipoproteins
(plasma proteins that carry cholesterol and triglycerides) without
adequate removal of fats and cholesterol from the macrophages by
functional high density lipoproteins (HDL). It is commonly referred
to as a hardening or furring of the arteries. It is caused by the
formation of multiple plaques within the arteries.
Abstract: Overloading is a technique to accommodate more
number of users than the spreading factor N. This is a bandwidth
efficient scheme to increase the number users in a fixed bandwidth.
One of the efficient schemes to overload a CDMA system is to use
two sets of orthogonal signal waveforms (O/O). The first set is
assigned to the N users and the second set is assigned to the
additional M users. An iterative interference cancellation technique is
used to cancel interference between the two sets of users. In this
paper, the performance of an overloading scheme in which the first N
users are assigned Walsh-Hadamard orthogonal codes and extra users
are assigned the same WH codes but overlaid by a fixed (quasi) bent
sequence [11] is evaluated. This particular scheme is called Quasi-
Orthogonal Sequence (QOS) O/O scheme, which is a part of
cdma2000 standard [12] to provide overloading in the downlink
using single user detector. QOS scheme are balance O/O scheme,
where the correlation between any set-1 and set-2 users are
equalized. The allowable overload of this scheme is investigated in
the uplink on an AWGN and Rayleigh fading channels, so that the
uncoded performance with iterative multistage interference
cancellation detector remains close to the single user bound. It is
shown that this scheme provides 19% and 11% overloading with
SDIC technique for N= 16 and 64 respectively, with an SNR
degradation of less than 0.35 dB as compared to single user bound at
a BER of 0.00001. But on a Rayleigh fading channel, the channel
overloading is 45% (29 extra users) at a BER of 0.0005, with an SNR
degradation of about 1 dB as compared to single user performance
for N=64. This is a significant amount of channel overloading on a
Rayleigh fading channel.
Abstract: In today-s economy plant engineering faces many
challenges. For instance the intensifying competition in this business
is leading to cost competition and needs for a shorter time-to-market.
To remain competitive companies need to make their businesses
more profitable by implementing improvement programs such as
standardization projects. But they have difficulties to tap their full
economic potential for various reasons. One of them is non-holistic
planning and implementation of standardization projects. This paper
describes a new conceptual framework - the layer-model. The model
combines and expands existing proven approaches in order to
improve design, implementation and management of standardization
projects. Based on a holistic approach it helps to systematically
analyze the effects of standardization projects on different business
layers and enables companies to better seize the opportunities offered
by standardization.
Abstract: The low power wireless sensor devices which usually
uses the low power wireless private area network (IEEE 802.15.4)
standard are being widely deployed for various purposes and in
different scenarios. IPv6 low power wireless private area network
(6LoWPAN) was adopted as part of the IETF standard for the
wireless sensor devices so that it will become an open standard
compares to other dominated proprietary standards available in the
market. 6LoWPAN also allows the integration and communication of
sensor nodes with the Internet more viable. This paper presents a
comparative study on different available IPv6 platforms for wireless
sensor networks including open and close sources. It also discusses
about the platforms used by these stacks. Finally it evaluates and
provides appropriate suggestions which can be use for selection of
required IPv6 stack for low power devices.
Abstract: Discrete Cosine Transform (DCT) based transform coding is very popular in image, video and speech compression due to its good energy compaction and decorrelating properties. However, at low bit rates, the reconstructed images generally suffer from visually annoying blocking artifacts as a result of coarse quantization. Lapped transform was proposed as an alternative to the DCT with reduced blocking artifacts and increased coding gain. Lapped transforms are popular for their good performance, robustness against oversmoothing and availability of fast implementation algorithms. However, there is no proper study reported in the literature regarding the statistical distributions of block Lapped Orthogonal Transform (LOT) and Lapped Biorthogonal Transform (LBT) coefficients. This study performs two goodness-of-fit tests, the Kolmogorov-Smirnov (KS) test and the 2- test, to determine the distribution that best fits the LOT and LBT coefficients. The experimental results show that the distribution of a majority of the significant AC coefficients can be modeled by the Generalized Gaussian distribution. The knowledge of the statistical distribution of transform coefficients greatly helps in the design of optimal quantizers that may lead to minimum distortion and hence achieve optimal coding efficiency.
Abstract: In this paper, application of Sliding Mode Control (SMC) technique for an Active Magnetic Bearing (AMB) system with varying rotor speed is considered. The gyroscopic effect and mass imbalance inherited in the system is proportional to rotor speed in which this nonlinearity effect causes high system instability as the rotor speed increases. Transformation of the AMB dynamic model into regular system shows that these gyroscopic effect and imbalance lie in the mismatched part of the system. A H2-based sliding surface is designed which bound the mismatched parts. The solution of the surface parameter is obtained using Linear Matrix Inequality (LMI). The performance of the controller applied to the AMB model is demonstrated through simulation works under various system conditions.
Abstract: The significance of psychology in studying politics
is embedded in philosophical issues as well as behavioural
pursuits. For the former is often associated with Sigmund Freud
and his followers. The latter is inspired by the writings of Harold
Lasswell. Political psychology or psychopolitics has its own
impression on political thought ever since it deciphers the concept
of human nature and political propaganda. More importantly,
psychoanalysis views political thought as a textual content which
needs to explore the latent from the manifest content. In other
words, it reads the text symptomatically and interprets the hidden
truth. This paper explains the paradigm of dream interpretation
applied by Freud. The dream work is a process which has four
successive activities: condensation, displacement, representation
and secondary revision. The texts dealing with political though can
also be interpreted on these principles. Freud's method of dream
interpretation draws its source after the hermeneutic model of
philological research. It provides theoretical perspective and
technical rules for the interpretation of symbolic structures. The
task of interpretation remains a discovery of equivalence of
symbols and actions through perpetual analogies. Psychoanalysis
can help in studying political thought in two ways: to study the text
distortion, Freud's dream interpretation is used as a paradigm
exploring the latent text from its manifest text; and to apply Freud's
psychoanalytic concepts and theories ranging from individual mind
to civilization, religion, war and politics.
Abstract: Phytophthora cinnamomi (P. c) is a plant pathogenic
oomycete that is capable of damaging plants in commercial production
systems and natural ecosystems worldwide. The most common
methods for the detection and diagnosis of P. c infection are
expensive, elaborate and time consuming. This study was carried out
to examine whether species specific and life cycle specific volatile
organic compounds (VOCs) can be absorbed by solid-phase
microextraction fibers and detected by gas chromatography that are
produced by P. c and another oomycete Pythium dissotocum. A
headspace solid-phase microextraction (HS-SPME) together with gas
chromatography (GC) method was developed and optimized for the
identification of the VOCs released by P. c. The optimized parameters
included type of fiber, exposure time, desorption temperature and
desorption time. Optimization was achieved with the analytes of P.
c+V8A and V8A alone. To perform the HS-SPME, six types of fiber
were assayed and compared: 7μm Polydimethylsiloxane (PDMS),
100μm Polydimethylsiloxane (PDMS), 50/30μm
Divinylbenzene/CarboxenTM/Polydimethylsiloxane
DVB/CAR/PDMS), 65μm Polydimethylsiloxane/Divinylbenzene
(PDMS/DVB), 85μm Polyacrylate (PA) fibre and 85μm CarboxenTM/
Polydimethylsiloxane (Carboxen™/PDMS). In a comparison of the
efficacy of the fibers, the bipolar fiber DVB/CAR/PDMS had a higher
extraction efficiency than the other fibers. An exposure time of 16h
with DVB/CAR/PDMS fiber in the sample headspace was enough to
reach the maximum extraction efficiency. A desorption time of 3min
in the GC injector with the desorption temperature of 250°C was
enough for the fiber to desorb the compounds of interest. The chromatograms and morphology study confirmed that the VOCs from
P. c+V8A had distinct differences from V8A alone, as did different
life cycle stages of P. c and different taxa such as Pythium dissotocum.
The study proved that P. c has species and life cycle specific VOCs,
which in turn demonstrated the feasibility of this method as means of
Abstract: In this paper channel estimation techniques are
considered as the support methods for OFDM transmission systems
based on Non Binary LDPC (Low Density Parity Check) codes.
Standard frequency domain pilot aided LS (Least Squares) and
LMMSE (Linear Minimum Mean Square Error) estimators are
investigated. Furthermore, an iterative algorithm is proposed as a
solution exploiting the NB-LDPC channel decoder to improve the
performance of the LMMSE estimator. Simulation results of signals
transmitted through fading mobile channels are presented to compare
the performance of the proposed channel estimators.
Abstract: The study aimed to identify the logical structure of
data and particularities of developing and testing a website designed
for selling farm products through online auctions.
The research is based on a short literature review in the field and
exploratory trials of some successful models from other industries, in
order to identify the advantages of using such tool, as well as the
optimal structure and functionality of an auction portal. In the last
part, the study focuses on the results of testing the website by the
potential beneficiaries.
Conclusions of the study underlines that the particularities of some
agricultural products could raise difficulties in the process of selling
them through online auctions, but the use of such system it is
perceived to bring significant improvements in the supply chain.
The results of scientific investigations require a more detailed
study regarding the importance of using quality standards for
agricultural products sold via online auction, the impact that
implementation of an online payment system could have on trade
with agricultural products and problems which could arise in using
the website in different countries.
Abstract: This paper provides new ways to explore the old
problem of failure of information systems development in an
organisation. Based on the theory of cognitive dissonance,
information systems (IS) failure is defined as a gap between what the
users expect from an information system and how well these
expectations are met by the perceived performance of the delivered
system. Bridging the expectation-perception gap requires that IS
professionals make a radical change from being the proprietor of
information systems and products to being service providers. In order
to deliver systems and services that IS users perceive as valuable, IS
people must become expert in determining and assessing users-
expectations and perceptions. It is also suggested that the IS
community, in general, has given relatively little attention to the
front-end process of requirements specification for IS development.
There is a simplistic belief that requirements are obtainable from
users, they are then translatable into a formal specification. The
process of information needs analysis is problematic and worthy of
investigation.
Abstract: TTV is an unenveloped circular single-stranded DNA
virus with a diameter of 30-32 nm that first was described in 1997 in
Japan. TTV was detected in various populations without proven
pathology, including blood donors and in patients with chronic HBV
and HCV hepatitis. The aim of this study was to determine the
prevalence of TTV DNA in Iranian patients with chronic hepatitis B
and C. Viral TTV-DNA was studied in 442 samples (202 with HBV,
138 with HCV and 102 controls) collected from west south of Iran.
All extracted serum DNA was amplified by TTV ORF1 gene specific
primers using the semi nested PCR technique. TTV DNA was
detected in the serum of 8.9% and 10.8% patients with chronic
hepatitis B and C, respectively. Prevalence of TTV-DNA in the serum
of 102 controls was 2.9%. Results showed significant relation of TTV
with HBV and HCV in patients by using T test examination (P
Abstract: According to dramatic growth of internet services, an easy and prompt service deployment has been important for internet service providers to successfully maintain time-to-market. Before global service deployment, they have to pay the big cost for service evaluation to make a decision of the proper system location, system scale, service delay and so on. But, intra-Lab evaluation tends to have big gaps in the measured data compared with the realistic situation, because it is very difficult to accurately expect the local service environment, network congestion, service delay, network bandwidth and other factors. Therefore, to resolve or ease the upper problems, we propose multiple cloud based GPES Broker system and use case that helps internet service providers to alleviate the above problems in beta release phase and to make a prompt decision for their service launching. By supporting more realistic and reliable evaluation information, the proposed GPES Broker system saves the service release cost and enables internet service provider to make a prompt decision about their service launching to various remote regions.
Abstract: Enterprise Architecture (EA) is a framework for description, coordination and alignment of all activities across the organization in order to achieve strategic goals using ICT enablers. A number of EA-compatible frameworks have been developed. We, in this paper, mainly focus on Federal Enterprise Architecture Framework (FEAF) since its reference models are plentiful. Among these models we are interested here in its business reference model (BRM). The test process is one important subject of an EA project which is to somewhat overlooked. This lack of attention may cause drawbacks or even failure of an enterprise architecture project. To address this issue we intend to use International Software Testing Qualification Board (ISTQB) framework and standard test suites to present a method to improve EA testing process. The main challenge is how to communicate between the concepts of EA and ISTQB. In this paper, we propose a method for integrating these concepts.
Abstract: Unmanned aerial vehicles (UAVs) performing their
operations for a long time have been attracting much attention in
military and civil aviation industries for the past decade. The
applicable field of UAV is changing from the military purpose only to
the civil one. Because of their low operation cost, high reliability and
the necessity of various application areas, numerous development
programs have been initiated around the world. To obtain the optimal
solutions of the design variable (i.e., sectional airfoil profile, wing
taper ratio and sweep) for high performance of UAVs, both the lift and
lift-to-drag ratio are maximized whereas the pitching moment should
be minimized, simultaneously. It is found that the lift force and
lift-to-drag ratio are linearly dependent and a unique and dominant
solution are existed. However, a trade-off phenomenon is observed
between the lift-to-drag ratio and pitching moment. As the result of
optimization, sixty-five (65) non-dominated Pareto individuals at the
cutting edge of design spaces that are decided by airfoil shapes can be
obtained.
Abstract: Information and Communications Technologies (ICT) has been integrated in education in many developing and developed countries alike, but the use of ICT in Tanzanian schools is dismal. Many Tanzanian secondary schools have no computers. The few schools with computers use them primarily for secretarial services and computer literacy training. The Tanzanian education system at other levels like secondary school level has to undergo substantial transformation, underscored by the growing application of new information and communication technology. This paper presents the e-readiness survey result from secondary schools in Tanzania. The paper also suggests how Tanzania can make use of the few present ICT resources to support and improve teaching and learning functions to improve performance and acquisition of knowledge by using e-Learning Management System (e-LMS).
Abstract: In this work, we consider the rational points on elliptic curves over finite fields Fp where p ≡ 5 (mod 6). We obtain results on the number of points on an elliptic curve y2 ≡ x3 + a3(mod p), where p ≡ 5 (mod 6) is prime. We give some results concerning the sum of the abscissae of these points. A similar case where p ≡ 1 (mod 6) is considered in [5]. The main difference between two cases is that when p ≡ 5 (mod 6), all elements of Fp are cubic residues.