Abstract: The purpose of this study was to investigate the
response of the newly released Gafchromic HD-V2 film for alpha
particle of 5.5 MeV. Gafchromic HD-V2 was exposed to alpha
particles of energy 5 MeV from 241Am for different durations. Then
the films were scanned with a flatbed scanner. The dose response
curve up to 2200 Gy has been achieved. The film’s reproducibility
and sensitivity were evaluated. The results obtained show that the net
optical density increases almost exponentially with the increase in the
exposure time, and it becomes saturated after prolonged exposure
times. The red channel shows the highest sensitivity, with a value of
4 x 10-3 Gy-1 at netOD of 0.4. The inter-film reproducibility was
measured and the relative uncertainty found was 1.7 %, 2.1 % and 2.3
% for grey, red and green channels, respectively.
Abstract: This paper proposes a visual cryptography by random
grids scheme with identifiable shares. The method encodes an image
O in two shares that exhibits the following features: (1) each generated
share has the same scale as O, (2) any share singly has noise-like
appearance that reveals no secret information on O, (3) the secrets can
be revealed by superimposing the two shares, (4) folding a share up
can disclose some identification patterns, and (5) both of the secret
information and the designated identification patterns are recognized
by naked eye without any computation. The property to show up
identification patterns on folded shares establishes a simple and
friendly interface for users to manage the numerous shares created by
VC schemes.
Abstract: In this paper, we propose a novel adaptive
spatiotemporal filter that utilizes image sequences in order to remove
noise. The consecutive frames include: current, previous and next
noisy frames. The filter proposed in this paper is based upon the
weighted averaging pixels intensity and noise variance in image
sequences. It utilizes the Appropriate Number of Consecutive Frames
(ANCF) based on the noisy pixels intensity among the frames. The
number of consecutive frames is adaptively calculated for each
region in image and its value may change from one region to another
region depending on the pixels intensity within the region. The
weights are determined by a well-defined mathematical criterion,
which is adaptive to the feature of spatiotemporal pixels of the
consecutive frames. It is experimentally shown that the proposed
filter can preserve image structures and edges under motion while
suppressing noise, and thus can be effectively used in image
sequences filtering. In addition, the AWA filter using ANCF is
particularly well suited for filtering sequences that contain segments
with abruptly changing scene content due to, for example, rapid
zooming and changes in the view of the camera.
Abstract: This paper studies the design of a simple constellation
precoding for a multiple-input multiple-output orthogonal frequency
division multiplexing (MIMO-OFDM) system over Rayleigh fading
channels where OFDM is used to keep the diversity replicas orthogonal
and reduce ISI effects. A multi-user environment with K synchronous
co-channel users is considered. The proposed scheme provides
a bandwidth efficient transmission for individual users by increasing
the system throughput. In comparison with the existing coded
MIMO-OFDM schemes, the precoding technique is designed under
the consideration of its low implementation complexity while providing
a comparable error performance to the existing schemes.
Analytic and simulation results have been presented to show the distinguished
error performance.
Abstract: This paper studies a vital issue in wireless
communications, which is the transmission of images over Wireless
Personal Area Networks (WPANs) through the Bluetooth network. It
presents a simple method to improve the efficiency of error control
code of old Bluetooth versions over mobile WPANs through
Interleaved Error Control Code (IECC) technique. The encoded
packets are interleaved by simple block interleaver. Also, the paper
presents a chaotic interleaving scheme as a tool against bursts of
errors which depends on the chaotic Baker map. Also, the paper
proposes using the chaotic interleaver instead of traditional block
interleaver with Forward Error Control (FEC) scheme. A comparison
study between the proposed and standard techniques for image
transmission over a correlated fading channel is presented.
Simulation results reveal the superiority of the proposed chaotic
interleaving scheme to other schemes. Also, the superiority of FEC
with proposed chaotic interleaver to the conventional interleavers
with enhancing the security level with chaotic interleaving packetby-
packet basis.
Abstract: Due to the legacy of apartheid segregation South Africa remains a divided society where most voters live in politically homogenous social environments. This paper argues that political discussion within one’s social context plays a primary role in shaping political attitudes and vote choice. Using data from the Comparative National Elections Project 2004 and 2009 South African post-election surveys, the paper explores the extent of social context partisan homogeneity in South Africa and finds that voters are not overly embedded in homogenous social contexts. It then demonstrates the consequences of partisan homogeneity on voting behavior. Homogenous social contexts tend to encourage stronger partisan loyalties and fewer defections in vote choice while voters in more heterogeneous contexts show less consistency in their attitudes and behaviour. Finally, the analysis shows how momentous sociopolitical events at the time of a particular election can change the social context, with important consequences for electoral outcomes.
Abstract: While in practice negotiation is always a mix of
cooperation and competition, these two elements correspond to
different approaches of the relationship and also different orientations
in term of strategy, techniques, tactics and arguments employed by
the negotiators with related effects and in the end leading to different
outcomes. The levels of honesty, trust and therefore cooperation are
influenced not only by the uncertainty of the situation, the objectives,
stakes or power but also by the orientation given from the very
beginning of the relationship. When negotiation is reduced to a
confrontation of power, participants rely on coercive measures, using
different kinds of threats or make false promises and bluff in order to
establish a more acceptable balance of power.
Most of the negotiators have a tendency to complain about the
unethical aspects of the tactics used by their counterparts while, as
the same time, they are mostly unaware of the sources of influence of
their own vision and practices. In this article, our intention is to
clarify these sources and try to understand what can lead negotiators
to unethical practices.
Abstract: Because of its global reach, reduction of time
restraints, and ability to reduce costs and increase sales, use of the
Internet, the World Wide Web (WWW), and related technologies
can be a competitive tool in the arsenal of small and medium-sized
enterprises (SMEs). Countries the world over are interested in the
successful adoption of the Internet by SMEs. Because a vast
majority of jobs come from that sector, greater financial success of
SMEs translates into greater job growth and, subsequently, higher
tax revenue to the government. This research investigated the level
of Internet usage for business solutions by small and medium
enterprises in Jordan. Through the survey of a random sample of
100 firms with less than 500 employees and from data obtained
from this survey that formed the basis for our study, we found that
a majority of respondents use the Internet in business activities ,
the adoption of the Internet as a business tool is limited to a
brochure where Web site which primarily provides one way. As
such, there wasn't interactive information about the company and
its products and services.
Abstract: In a competitive energy market, system reliability
should be maintained at all times. Power system operation being of
online in nature, the energy balance requirements must be satisfied to
ensure reliable operation the system. To achieve this, information
regarding the expected status of the system, the scheduled
transactions and the relevant inputs necessary to make either a
transaction contract or a transmission contract operational, have to be
made available in real time. The real time procedure proposed,
facilitates this. This paper proposes a quadratic curve learning
procedure, which enables a generator-s contribution to the retailer
demand, power loss of transaction in a line at the retail end and its
associated losses for an oncoming operating scenario to be predicted.
Matlab program was used to test in on a 24-bus IEE Reliability Test
System, and the results are found to be acceptable.
Abstract: There have been many games developing simulation
of soccer games. Many of these games have been designed with
highly realistic features to attract more users. Many have also
incorporated better artificial intelligent (AI) similar to that in a real
soccer game. One of the challenging issues in a soccer game is the
cooperation, coordination and negotiation among distributed agents
in a multi-agent system. This paper focuses on the incorporation of
multi-agent technique in a soccer game domain. The better the
cooperation of a multi-agent team, the more intelligent the game will
be. Thus, past studies were done on the robotic soccer game because
of the better multi-agent system implementation. From this study, a
better approach and technique of multi-agent behavior could be
select to improve the author-s 2D online soccer game.
Abstract: Recently, content delivery services have grown rapidly
over the Internet. For ASPs (Application Service Provider) providing
content delivery services, P2P architecture is beneficial to reduce
outgoing traffic from content servers. On the other hand, ISPs are
suffering from the increase in P2P traffic. The P2P traffic is
unnecessarily redundant because the same content or the same
fractions of content are transferred through an inter-ISP link several
times. Subscriber ISPs have to pay a transit fee to upstream ISPs based
on the volume of inter-ISP traffic. In order to solve such problems,
several works have been done for the purpose of P2P traffic reduction.
However, these existing works cannot control the traffic volume of a
certain link. In order to solve such an ISP-s operational requirement,
we propose a method to control traffic volume for a link within a
preconfigured upper bound value. We evaluated that the proposed
method works well by conducting a simulation on a 1,000-user scale.
We confirm that the traffic volume could be controlled at a lower level
than the upper bound for all evaluated conditions. Moreover, our
method could control the traffic volume at 98.95% link usage against
the target value.
Abstract: Tribological behavior and wear regimes of ascast
and heattreted Al-Cu-Mg matrix composites containing SiC
particles were studied using a pin-on-disc wear testing apparatus
against an EN32 steel counterface giving emphasis on wear rate as
a function of applied pressures (0.2, 0.6, 1.0 and 1.4 MPa) at
different sliding distances (1000, 2000, 3000, 4000 and 5000
meters) and at a fixed sliding speed of 3.35m/s. The results showed
that the composite exhibited lower wear rate than that of the matrix
alloy and the wear rate of the composites is noted to be invariant to
the sliding distance and is reducing by heat treatment. Wear
regimes such as low, mild and severe wear were observed as per the
Archard-s wear calculations. It is very interesting to note that the
mild wear is almost constant in all the wear regimes.
Abstract: In this paper we present a new method for over-height
vehicle detection in low headroom streets and highways using digital
video possessing. The accuracy and the lower price comparing to
present detectors like laser radars and the capability of providing
extra information like speed and height measurement make this
method more reliable and efficient. In this algorithm the features are
selected and tracked using KLT algorithm. A blob extraction
algorithm is also applied using background estimation and
subtraction. Then the world coordinates of features that are inside the
blobs are estimated using a noble calibration method. As, the heights
of the features are calculated, we apply a threshold to select overheight
features and eliminate others. The over-height features are
segmented using some association criteria and grouped using an
undirected graph. Then they are tracked through sequential frames.
The obtained groups refer to over-height vehicles in a scene.
Abstract: In this paper, the C1-conforming finite element method is analyzed for a class of nonlinear fourth-order hyperbolic partial differential equation. Some a priori bounds are derived using Lyapunov functional, and existence, uniqueness and regularity for the weak solutions are proved. Optimal error estimates are derived for both semidiscrete and fully discrete schemes.
Abstract: This present paper proposes the modified Elastic Strip
method for mobile robot to avoid obstacles with a real time system in
an uncertain environment. The method deals with the problem of
robot in driving from an initial position to a target position based on
elastic force and potential field force. To avoid the obstacles, the
robot has to modify the trajectory based on signal received from the
sensor system in the sampling times. It was evident that with the
combination of Modification Elastic strip and Pseudomedian filter to
process the nonlinear data from sensor uncertainties in the data
received from the sensor system can be reduced. The simulations and
experiments of these methods were carried out.
Abstract: This paper presents modeling and optimization of two NP-hard problems in flexible manufacturing system (FMS), part type selection problem and loading problem. Due to the complexity and extent of the problems, the paper was split into two parts. The first part of the papers has discussed the modeling of the problems and showed how the real coded genetic algorithms (RCGA) can be applied to solve the problems. This second part discusses the effectiveness of the RCGA which uses an array of real numbers as chromosome representation. The novel proposed chromosome representation produces only feasible solutions which minimize a computational time needed by GA to push its population toward feasible search space or repair infeasible chromosomes. The proposed RCGA improves the FMS performance by considering two objectives, maximizing system throughput and maintaining the balance of the system (minimizing system unbalance). The resulted objective values are compared to the optimum values produced by branch-and-bound method. The experiments show that the proposed RCGA could reach near optimum solutions in a reasonable amount of time.
Abstract: There are three approaches to complete Bayesian
Network (BN) model construction: total expert-centred, total datacentred,
and semi data-centred. These three approaches constitute the
basis of the empirical investigation undertaken and reported in this
paper. The objective is to determine, amongst these three
approaches, which is the optimal approach for the construction of a
BN-based model for the performance assessment of students-
laboratory work in a virtual electronic laboratory environment. BN
models were constructed using all three approaches, with respect to
the focus domain, and compared using a set of optimality criteria. In
addition, the impact of the size and source of the training, on the
performance of total data-centred and semi data-centred models was
investigated. The results of the investigation provide additional
insight for BN model constructors and contribute to literature
providing supportive evidence for the conceptual feasibility and
efficiency of structure and parameter learning from data. In addition,
the results highlight other interesting themes.
Abstract: A numerical simulation of micro Poiseuille flow has
performed for rarefied and compressible flow at slip flow regimes.
The wall roughness is simulated in two cases with triangular
microelements and random micro peaks distributed on wall surfaces
to study the effects of roughness shape and distribution on flow field.
Two values of Mach and Knudsen numbers have used to investigate
the effects of rarefaction as well as compressibility. The numerical
results have also checked with available theoretical and experimental
relations and good agreements has achieved. High influence of
roughness shape can be seen for both compressible and
incompressible rarefied flows. In addition it is found that rarefaction
has more significant effect on flow field in microchannels with
higher relative roughness. It is also found that compressibility has
more significant effects on Poiseuille number when relative
roughness increases.
Abstract: This paper presents a dynamic adaptation scheme for
the frequency of inter-deme migration in distributed genetic algorithms
(GA), and its VLSI hardware design. Distributed GA,
or multi-deme-based GA, uses multiple populations which evolve
concurrently. The purpose of dynamic adaptation is to improve
convergence performance so as to obtain better solutions. Through
simulation experiments, we proved that our scheme achieves better
performance than fixed frequency migration schemes.
Abstract: The Internet is the global data communications
infrastructure based on the interconnection of both public and private
networks using protocols that implement Internetworking on a global
scale. Hence the control of protocol and infrastructure development,
resource allocation and network operation are crucial and interlinked
aspects. Internet Governance is the hotly debated and contentious
subject that refers to the global control and operation of key Internet
infrastructure such as domain name servers and resources such as
domain names. It is impossible to separate technical and political
positions as they are interlinked. Furthermore the existence of a
global market, transparency and competition impact upon Internet
Governance and related topics such as network neutrality and
security. Current trends and developments regarding Internet
governance with a focus on the policy-making process, security and
control have been observed to evaluate current and future
implications on the Internet. The multi stakeholder approach to
Internet Governance discussed in this paper presents a number of
opportunities, issues and developments that will affect the future
direction of the Internet. Internet operation, maintenance and
advisory organisations such as the Internet Corporation for Assigned
Names and Numbers (ICANN) or the Internet Governance Forum
(IGF) are currently in the process of formulating policies for future
Internet Governance. Given the controversial nature of the issues at
stake and the current lack of agreement it is predicted that
institutional as well as market governance will remain present for the
network access and content.