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: III-nitride quaternary InxAlyGa1-x-yN alloys have experienced considerable interest as potential materials for optoelectronic applications. Despite these interesting applications and the extensive efforts to understand their fundamental properties, research on its fundamental surface property, i.e., surface phonon polariton (SPP) has not yet been reported. In fact, the SPP properties have been shown to provide application for some photonic devices. Hence, there is an absolute need for thorough studies on the SPP properties of this material. In this work, theoretical study on the SPP modes in InAlGaN quaternary alloys are reported. Attention is focus on the wurtzite (α-) structure InxAlyGa1-x-yN semi-crystal with different In composition, x ranging from 0 to 0.10 and constant Al composition, y = 0.06. The SPP modes are obtained through the theoretical simulation by means of anisotropy model. The characteristics of SP dispersion curves are discussed. Accessible results in terms of the experimental point of view are also given. Finally, the results revealed that the SPP mode of α-InxAlyGa1-x-yN semiconductors exhibits two-mode behavior.
Abstract: A new and highly efficient architecture for elliptic curve scalar point multiplication which is optimized for a binary field recommended by NIST and is well-suited for elliptic curve cryptographic (ECC) applications is presented. To achieve the maximum architectural and timing improvements we have reorganized and reordered the critical path of the Lopez-Dahab scalar point multiplication architecture such that logic structures are implemented in parallel and operations in the critical path are diverted to noncritical paths. With G=41, the proposed design is capable of performing a field multiplication over the extension field with degree 163 in 11.92 s with the maximum achievable frequency of 251 MHz on Xilinx Virtex-4 (XC4VLX200) while 22% of the chip area is occupied, where G is the digit size of the underlying digit-serial finite field multiplier.
Abstract: As the world changes more rapidly, the demand for update information for resource management, environment monitoring, planning are increasing exponentially. Integration of Remote Sensing with GIS technology will significantly promote the ability for addressing these concerns. This paper presents an alternative way of update GIS applications using image processing and high resolution images. We show a method of high-resolution image segmentation using graphs and morphological operations, where a preprocessing step (watershed operation) is required. A morphological process is then applied using the opening and closing operations. After this segmentation we can extract significant cartographic elements such as urban areas, streets or green areas. The result of this segmentation and this extraction is then used to update GIS applications. Some examples are shown using aerial photography.
Abstract: Due to their high power-to-weight ratio and low cost, pneumatic actuators are attractive for robotics and automation applications; however, achieving fast and accurate control of their position have been known as a complex control problem. The paper presents a methodology for obtaining controllers that achieve high position accuracy and preserve the closed-loop characteristics over a broad operating range. Experimentation with a number of conventional (or "classical") three-term controllers shows that, as repeated operations accumulate, the characteristics of the pneumatic actuator change requiring frequent re-tuning of the controller parameters (PID gains). Furthermore, three-term controllers are found to perform poorly in recovering the closed-loop system after the application of load or other external disturbances. The key reason for these problems lies in the non-linear exchange of energy inside the cylinder relating, in particular, to the complex friction forces that develop on the piston-wall interface. In order to overcome this problem but still remain within the boundaries of classical control methods, we designed an auto selective classicaql controller so that the system performance would benefit from all three control gains (KP, Kd, Ki) according to system requirements and the characteristics of each type of controller. This challenging experimentation took place for consistent performance in the face of modelling imprecision and disturbances. In the work presented, a selective PID controller is presented for an experimental rig comprising an air cylinder driven by a variable-opening pneumatic valve and equipped with position and pressure sensors. The paper reports on tests carried out to investigate the capability of this specific controller to achieve consistent control performance under, repeated operations and other changes in operating conditions.
Abstract: Most of the collision warning systems currently
available in the automotive market are mainly designed to warn
against imminent rear-end and lane-changing collisions. No collision
warning system is commercially available to warn against imminent
turning collisions at intersections, especially for left-turn collisions
when a driver attempts to make a left-turn at either a signalized or
non-signalized intersection, conflicting with the path of other
approaching vehicles traveling on the opposite-direction traffic
stream. One of the major factors that lead to left-turn collisions is the
human error and misjudgment of the driver of the turning vehicle
when perceiving the speed and acceleration of other vehicles
traveling on the opposite-direction traffic stream; therefore, using a
properly-designed collision warning system will likely reduce, or
even eliminate, this type of collisions by reducing human error. This
paper introduces perceptual framework for a proposed collision
warning system that can detect imminent left-turn collisions at
intersections. The system utilizes a commercially-available detection
sensor (either a radar sensor or a laser detector) to detect approaching
vehicles traveling on the opposite-direction traffic stream and
calculate their speeds and acceleration rates to estimate the time-tocollision
and compare that time to the time required for the turning
vehicle to clear the intersection. When calculating the time required
for the turning vehicle to clear the intersection, consideration is given
to the perception-reaction time of the driver of the turning vehicle,
which is the time required by the driver to perceive the message
given by the warning system and react to it by engaging the throttle.
A regression model was developed to estimate perception-reaction
time based on age and gender of the driver of the host vehicle.
Desired acceleration rate selected by the driver of the turning vehicle,
when making the left-turn movement, is another human factor that is
considered by the system. Another regression model was developed
to estimate the acceleration rate selected by the driver of the turning
vehicle based on driver-s age and gender as well as on the location
and speed of the nearest approaching vehicle along with the
maximum acceleration rate provided by the mechanical
characteristics of the turning vehicle. By comparing time-to-collision
with the time required for the turning vehicle to clear the intersection,
the system displays a message to the driver of the turning vehicle
when departure is safe. An application example is provided to
illustrate the logic algorithm of the proposed system.
Abstract: The paper presents the service learning project titled
DicDucFac (idea-leadership-product), that was planned and
conducted by the team of information sciences students. It was
planned as a workshop dealing with the application of modern social
media (Facebook, YouTube, Gmail) for the purposes of selfpromotion,
free advertising via social networks and marketing own
ideas and/or products in the virtual world. The workshop was
organized for highly-skilled computer literate unemployed youth.
These youth, as final beneficiaries, will be able to apply what they
learned in this workshop to “the real world“, increasing their chances
for employment and self-employment. The results of the project
reveal that the basic, active-learning principles embodied in our
teaching approach allow students to learn more effectively and gain
essential life skills (from computer applications to teamwork) that
can only be learned by doing. It also shows that our students received
the essentials of professional ethics and citizenship through direct,
personal engagement in professional activities and the life of the
community.
Abstract: Categorical data based on description of the
agricultural landscape imposed some mathematical and analytical
limitations. This problem however can be overcome by data
transformation through coding scheme and the use of non-parametric
multivariate approach. The present study describes data
transformation from qualitative to numerical descriptors. In a
collection of 103 random soil samples over a 60 hectare field,
categorical data were obtained from the following variables: levels of
nitrogen, phosphorus, potassium, pH, hue, chroma, value and data on
topography, vegetation type, and the presence of rocks. Categorical
data were coded, and Spearman-s rho correlation was then calculated
using PAST software ver. 1.78 in which Principal Component
Analysis was based. Results revealed successful data transformation,
generating 1030 quantitative descriptors. Visualization based on the
new set of descriptors showed clear differences among sites, and
amount of variation was successfully measured. Possible applications
of data transformation are discussed.
Abstract: In an electric power system, spinning reserve
requirements can be determined by using deterministic and/or
probabilistic measures. Although deterministic methods are usual in
many systems, application of probabilistic methods becomes
increasingly important in the new environment of the electric power
utility industry. This is because of the increased uncertainty
associated with competition. In this paper 1) a new probabilistic
method is presented which considers the reliability of transmission
system in a simplified manner and 2) deterministic and probabilistic
methods are compared. The studied methods are applied to the Roy
Billinton Test System (RBTS).
Abstract: By analyzing the sources of energy and power
loss in PWM (Pulse Width Modulation) controlled drivers of
water electrolysis cells, it is possible to reduce the power
dissipation and enhance the efficiency of such hydrogen
production units. A PWM controlled power driver is based on
a semiconductor switching element where its power
dissipation might be a remarkable fraction of the total power
demand of an electrolysis system. Power dissipation in a
semiconductor switching element is related to many different
parameters which could be fitted into two main categories:
switching losses and conduction losses. Conduction losses are
directly related to the built, structure and capabilities of a
switching device itself and indeed the conditions in which the
element is handling the switching application such as voltage,
current, temperature and of course the fabrication technology.
On the other hand, switching losses have some other
influencing variables other than the mentioned such as control
system, switching method and power electronics circuitry of
the PWM power driver. By analyzings the characteristics of
recently developed power switching transistors from different
families of Bipolar Junction Transistors (BJT), Metal Oxide
Semiconductor Field Effect Transistors (MOSFET) and
Insulated Gate Bipolar Transistors (IGBT), some
recommendations are made in this paper which are able to
lead to achieve higher hydrogen production efficiency by
utilizing PWM controlled water electrolysis cells.
Abstract: In intensity modulated radiation therapy (IMRT)
treatment planning, beam angles are usually preselected on the basis of
experience and intuition. Therefore, getting an appropriate beam
configuration needs a very long time. Based on the present situation,
the paper puts forward beam orientation optimization using ant colony
optimization (ACO). We use ant colony optimization to select the
beam configurations, after getting the beam configuration using
Conjugate Gradient (CG) algorithm to optimize the intensity profiles.
Combining with the information of the effect of pencil beam, we can
get the global optimal solution accelerating. In order to verify the
feasibility of the presented method, a simulated and clinical case was
tested, compared with dose-volume histogram and isodose line
between target area and organ at risk. The results showed that the
effect was improved after optimizing beam configurations. The
optimization approach could make treatment planning meet clinical
requirements more efficiently, so it had extensive application
perspective.
Abstract: With the widespread growth of applications of
Wireless Sensor Networks (WSNs), the need for reliable security
mechanisms these networks has increased manifold. Many security
solutions have been proposed in the domain of WSN so far. These
solutions are usually based on well-known cryptographic
algorithms.
In this paper, we have made an effort to survey well known
security issues in WSNs and study the behavior of WSN nodes that
perform public key cryptographic operations. We evaluate time
and power consumption of public key cryptography algorithm for
signature and key management by simulation.
Abstract: This paper is to present context-aware sensor grid
framework for agriculture and its design challenges. Use of sensor
networks in the domain of agriculture is not new. However, due to
the unavailability of any common framework, solutions that are
developed in this domain are location, environment and problem
dependent. Keeping the need of common framework for agriculture,
Context-Aware Sensor Grid Framework is proposed. It will be
helpful in developing solutions for majority of the problems related
to irrigation, pesticides spray, use of fertilizers, regular monitoring of
plot and yield etc. due to the capability of adjusting according to
location and environment. The proposed framework is composed of
three layer architecture including context-aware application layer,
grid middleware layer and sensor network layer.
Abstract: Sensors possess several properties of physical
measures. Whether devices that convert a sensed signal into an
electrical signal, chemical sensors and biosensors, thus all these
sensors can be considered as an interface between the physical and
electrical equipment. The problem is the analysis of the multitudes of
saved settings as input variables. However, they do not all have the
same level of influence on the outputs. In order to identify the most
sensitive parameters, those that can guide users in gathering
information on the ground and in the process of model calibration
and sensitivity analysis for the effect of each change made.
Mathematical models used for processing become very complex.
In this paper a fuzzy rule-based system is proposed as a solution
for this problem. The system collects the available signals
information from sensors. Moreover, the system allows the study of
the influence of the various factors that take part in the decision
system. Since its inception fuzzy set theory has been regarded as a
formalism suitable to deal with the imprecision intrinsic to many
problems. At the same time, fuzzy sets allow to use symbolic models.
In this study an example was applied for resolving variety of
physiological parameters that define human health state. The
application system was done for medical diagnosis help. The inputs
are the signals expressed the cardiovascular system parameters, blood
pressure, Respiratory system paramsystem was done, it will be able
to predict the state of patient according any input values.
Abstract: The blood ducts must be occluded to avoid loss of
blood from vessels in laparoscopic surgeries. This paper presents a
locking mechanism to be used in a ligation laparoscopic procedure
(LigLAP I), as an alternative solution for a stapling procedure.
Currently, stapling devices are being used to occlude vessels. Using
these devices may result in some problems, including injury of bile
duct, taking up a great deal of space behind the vessel, and bile leak.
In this new procedure, a two-layer suture occludes a vessel. A
locking mechanism is also required to hold the suture. Since there is
a limited space at the device tip, a Shape Memory Alloy (SMA)
actuator is used in this mechanism. Suitability for cleanroom
applications, small size, and silent performance are among the
advantages of SMA actuators in biomedical applications. An
experimental study is conducted to examine the function of the
locking mechanism. To set up the experiment, a prototype of a
locking mechanism is built using nitinol, which is a nickel-titanium
shape memory alloy. The locking mechanism successfully locks a
polymer suture for all runs of the experiment. In addition, the effects
of various surface materials on the applied pulling forces are studied.
Various materials are mounted at the mechanism tip to compare the
maximum pulling forces applied to the suture for each material. The
results show that the various surface materials on the device tip
provide large differences in the applied pulling forces.
Abstract: Silicon is a beneficial element for plant growth. It
helps plants to overcome multiple stresses, alleviates metal toxicity
and improves nutrient imbalance. Field experiment was conducted as
split-split plot arranged in a randomized complete block design with
four replications. Irrigation system include continues flooding and
deficit as main plots and nitrogen rates N0, N46, N92, and N138 kg/ha
as sub plots and silicon rates Si0 & Si500 kg/ha as sub-subplots.
Results indicate that grain yield had not significant difference
between irrigation systems. Flooding irrigation had higher biological
yield than deficit irrigation whereas, no significant difference in grain
and straw yield. Nitrogen application increased grain, biological and
straw yield. Silicon application increased grain, biological and straw
yield but, decreased harvest index. Flooding irrigation had higher
number of total tillers / hill than deficit irrigation, but deficit
irrigation had higher number of fertile tillers / hill than flooding
irrigation. Silicon increased number of filled spikelet and decreased
blank spikelet. With high nitrogen application decreased 1000-grain
weight. It can be concluded that if the nitrogen application was high
and water supplied was available we could have silicon application
until increase grain yield.
Abstract: The field of biomedical materials plays an imperative
requisite and a critical role in manufacturing a variety of biological
artificial replacements in a modern world. Recently, titanium (Ti)
materials are being used as biomaterials because of their superior
corrosion resistance and tremendous specific strength, free- allergic
problems and the greatest biocompatibility compared to other
competing biomaterials such as stainless steel, Co-Cr alloys,
ceramics, polymers, and composite materials. However, regardless of
these excellent performance properties, Implantable Ti materials have
poor shear strength and wear resistance which limited their
applications as biomaterials. Even though the wear properties of Ti
alloys has revealed some improvements, the crucial effectiveness of
biomedical Ti alloys as wear components requires a comprehensive
deep understanding of the wear reasons, mechanisms, and techniques
that can be used to improve wear behavior. This review examines
current information on the effect of thermal and thermomechanical
processing of implantable Ti materials on the long-term prosthetic
requirement which related with wear behavior. This paper focuses
mainly on the evolution, evaluation and development of effective
microstructural features that can improve wear properties of bio
grade Ti materials using thermal and thermomechanical treatments.
Abstract: Recently, nanomaterials are developed in the form of nano-films, nano-crystals and nano-pores. Lanthanide phosphates as a material find extensive application as laser, ceramic, sensor, phosphor, and also in optoelectronics, medical and biological labels, solar cells and light sources. Among the different kinds of rare-earth orthophosphates, yttrium orthophosphate has been shown to be an efficient host lattice for rare earth activator ions, which have become a research focus because of their important role in the field of light display systems, lasers, and optoelectronic devices. It is in this context that the 4fn- « 4fn-1 5d transitions of rare earth in insulating materials, lying in the UV and VUV, are the aim of large number of studies .Though there has been a few reports on Eu3+, Nd3+, Pr3+,Er3+, Ce3+, Tm3+ doped YPO4. The 4fn- « 4fn-1 5d transitions of the rare earth dependent to the host-matrix, several matrices ions were used to study these transitions, in this work we are suggesting to study on a very specific class of inorganic material that are orthophosphate doped with rare earth ions. This study focused on the effect of Ce3+ concentration on the structural and optical properties of Ce3+ doped YPO4 yttrium orthophosphate with powder form prepared by the Sol Gel method.
Abstract: In recent years with the rapid development of Internet and the Web, more and more web applications have been deployed in many fields and organizations such as finance, military, and government. Together with that, hackers have found more subtle ways to attack web applications. According to international statistics, SQL Injection is one of the most popular vulnerabilities of web applications. The consequences of this type of attacks are quite dangerous, such as sensitive information could be stolen or authentication systems might be by-passed. To mitigate the situation, several techniques have been adopted. In this research, a security solution is proposed using Artificial Neural Network to protect web applications against this type of attacks. The solution has been experimented on sample datasets and has given promising result. The solution has also been developed in a prototypic web application firewall called ANNbWAF.
Abstract: Robots- visual perception is a field that is gaining
increasing attention from researchers. This is partly due to emerging
trends in the commercial availability of 3D scanning systems or
devices that produce a high information accuracy level for a variety of
applications. In the history of mining, the mortality rate of mine workers
has been alarming and robots exhibit a great deal of potentials to
tackle safety issues in mines. However, an effective vision system
is crucial to safe autonomous navigation in underground terrains.
This work investigates robots- perception in underground terrains
(mines and tunnels) using statistical region merging (SRM) model.
SRM reconstructs the main structural components of an imagery
by a simple but effective statistical analysis. An investigation is
conducted on different regions of the mine, such as the shaft, stope
and gallery, using publicly available mine frames, with a stream of
locally captured mine images. An investigation is also conducted on a
stream of underground tunnel image frames, using the XBOX Kinect
3D sensors. The Kinect sensors produce streams of red, green and
blue (RGB) and depth images of 640 x 480 resolution at 30 frames per
second. Integrating the depth information to drivability gives a strong
cue to the analysis, which detects 3D results augmenting drivable and
non-drivable regions in 2D. The results of the 2D and 3D experiment
with different terrains, mines and tunnels, together with the qualitative
and quantitative evaluation, reveal that a good drivable region can be
detected in dynamic underground terrains.