Abstract: The quality-of-service (QoS) support for wireless
LANs has been a hot research topic during the past few years. In this paper, two QoS provisioning mechanisms are proposed for the employment in 802.11e EDCA MAC scheme. First, the proposed call
admission control mechanism can not only guarantee the QoS for the higher priority existing connections but also provide the minimum reserved bandwidth for traffic flows with lower priority. In addition, the adaptive contention window adjustment mechanism can adjust the
maximum and minimum contention window size dynamically according to the existing connection number of each AC. The collision
probability as well as the packet delay will thus be reduced effectively.
Performance results via simulations have revealed the enhanced QoS property achieved by employing these two mechanisms.
Abstract: an intelligent BRT system is necessary when
communities looking for new ways to use high capacity rapid transit
at a reduced cost.This paper will describe the intelligent control
system that works with Datacenter. With the help of GPS system, the
data center can monitor the situation of each bus and bus station.
Through RFID technology, bus station and traffic light can transfer
data with bus and by Wimax communication technology all of parts
can talk together; data center learns all information about the location
of bus, the arrival of bus in each station and the number of passengers
in station and bus.Finally, the paper presents the case study of those
theories in Tehran BRT.
Abstract: Image segmentation is an important step in image
processing. Major developments in medical imaging allow
physicians to use potent and non-invasive methods in order to
evaluate structures, performance and to diagnose human diseases. In
this study, an active contour was used to extract vessel networks
from color retina images. Automatic analysis of retina vessels
facilitates calculation of arterial index which is required to diagnose
some certain retinopathies.
Abstract: This paper presents a model for analysis the induced voltage of transmission lines (energized) acting on neighboring distribution lines (de-energized). From environmental restrictions, 22 kV distribution lines need to be installed under 115 kV transmission lines. With the installation of the two parallel circuits like this, they make the induced voltage which can cause harm to operators. This work was performed with the ATP-EMTP modeling to analyze such phenomenon before field testing. Simulation results are used to find solutions to prevent danger to operators who are on the pole.
Abstract: In this paper DJess is presented, a novel distributed production system that provides an infrastructure for factual and procedural knowledge sharing. DJess is a Java package that provides programmers with a lightweight middleware by which inference systems implemented in Jess and running on different nodes of a network can communicate. Communication and coordination among inference systems (agents) is achieved through the ability of each agent to transparently and asynchronously reason on inferred knowledge (facts) that might be collected and asserted by other agents on the basis of inference code (rules) that might be either local or transmitted by any node to any other node.
Abstract: Steganography, derived from Greek, literally means
“covered writing". It includes a vast array of secret communications
methods that conceal the message-s very existence. These methods
include invisible inks, microdots, character arrangement, digital
signatures, covert channels, and spread spectrum communications.
This paper proposes a new improved version of Least Significant Bit
(LSB) method. The approach proposed is simple for implementation
when compared to Pixel value Differencing (PVD) method and yet
achieves a High embedding capacity and imperceptibility. The
proposed method can also be applied to 24 bit color images and
achieve embedding capacity much higher than PVD.
Abstract: Launch and recovery helicopter wind envelope for a
ship type was determined as the first step to the helicopter
qualification program. Flight deck velocities data were obtained by
means of a two components laser Doppler anemometer testing a
1/50th model in the wind tunnel stream. Full-scale flight deck
measurements were obtained on board the ship using a sonic
anemometer. Wind tunnel and full-scale measurements were
compared, showing good agreement and finally, a preliminary launch
and recovery helicopter wind envelope for this specific ship was
built.
Abstract: Von Willebrand-s disease is the most common
inherited bleeding disorder in humans, it
caused by qualitative abnormalities of the von Willebrand factor
(vWF). Our objective is to determine the prevalence of this disease at
part of the Algerian population in the East and the South by a
biological diagnosis based on specific biological tests (automated
platelet count, the bleeding time (TS), the time of cephalin + activator
(TCA), measure of the prothrombin rate (TP), vWF rate and factor
VIII rate, Molecular electrophoresis of vWF multimers in agarose gel
in the presence of SDS). Four patients of type III or severe
Willebrand-s disease were found on 200 suspect cases. All cases are
showed a deficit in vWF rate (< 5%), and factor VIII (P
Abstract: K-Modes is an extension of K-Means clustering algorithm, developed to cluster the categorical data, where the mean is replaced by the mode. The similarity measure proposed by Huang is the simple matching or mismatching measure. Weight of attribute values contribute much in clustering; thus in this paper we propose a new weighted dissimilarity measure for K-Modes, based on the ratio of frequency of attribute values in the cluster and in the data set. The new weighted measure is experimented with the data sets obtained from the UCI data repository. The results are compared with K-Modes and K-representative, which show that the new measure generates clusters with high purity.
Abstract: Nowadays for algae cell ultrasonication the
longitudinal ultrasonic piezosystems are used. In this paper a
possibility of creating unique ultrasonic piezoelectric system, which
would allow reducing energy losses and concentrating this energy to
a small closed volume are proposed. The current vibrating systems
whose ultrasonic energy is concentrated inside of hollow cylinder in
which water-algae mixture is flowing. Two, three or multiply
ultrasonic composite systems to concentrate total energy into a
hollow cylinder to creating strong algae cell ultrasonication are used.
The experiments and numerical FEM analysis results using diskshaped
transducer and the first biological test results on algae cell
disruption by ultrasonication are presented as well.
Abstract: A study concerning the photocatalytic decolourization
of Congo red (CR) dye, over artificial UV irradiation is presented.
Photocatalysts based on a commercial titanium dioxide (TiO2)
modified with transition metals (Ni, Cu and Zn) were used. The
dopage method used was wet impregnation. A TiO2 sample without
salt was subjected to the same hydrothermal treatment to be used as
reference. Congo red solutions to several pH conditions (natural and
basic) were used to evaluate photocatalytic performance of each
doped catalysts. Photodecolourization percentage was measured
spectrofotrometically after 3 h of treatment to 499 nm as response
variable. Kinetics investigations of photodegradation indicated that
reactions obey to Langmuir-Hinshelwood model and pseudo–first
order law. The rate constant studies of photocatalytic decolourization
reactions for Zn–TiO2 and Cu–TiO2 photocatalysts indicated that in
all cases the rate constant of the reaction was higher than that of TiO2
undoped. These results show that nature of the metal modifying the
TiO2 influence on the efficiency of the photocatalyst evaluated in
process. Ni does not present an additional effect compared with TiO2,
while Zn enhances the photoactivity due to its electronic properties.
Abstract: Each new semiconductor technology node
brings smaller transistors and wires. Although this makes
transistors faster, wires get slower. In nano-scale regime, the
standard copper (Cu) interconnect will become a major hurdle
for FPGA interconnect due to their high resistivity and
electromigration. This paper presents the comprehensive
evaluation of mixed CNT bundle interconnects and
investigates their prospects as energy efficient and high speed
interconnect for future FPGA routing architecture. All
HSPICE simulations are carried out at operating frequency of
1GHz and it is found that mixed CNT bundle implemented in
FPGAs as interconnect can potentially provide a substantial
delay and energy reduction over traditional interconnects at
32nm process technology.
Abstract: In cryptography, confusion and diffusion are very
important to get confidentiality and privacy of message in block
ciphers and stream ciphers. There are two types of network to provide
confusion and diffusion properties of message in block ciphers. They
are Substitution- Permutation network (S-P network), and Feistel
network. NLFS (Non-Linear feedback stream cipher) is a fast and
secure stream cipher for software application. NLFS have two modes
basic mode that is synchronous mode and self synchronous mode.
Real random numbers are non-deterministic. R-box (random box)
based on the dynamic properties and it performs the stochastic
transformation of data that can be used effectively meet the
challenges of information is protected from international destructive
impacts. In this paper, a new implementation of stochastic
transformation will be proposed.
Abstract: For the past couple of decades Weak signal detection
is of crucial importance in various engineering and scientific
applications. It finds its application in areas like Wireless
communication, Radars, Aerospace engineering, Control systems and
many of those. Usually weak signal detection requires phase sensitive
detector and demodulation module to detect and analyze the signal.
This article gives you a preamble to intrusion detection system which
can effectively detect a weak signal from a multiplexed signal. By
carefully inspecting and analyzing the respective signal, this
system can successfully indicate any peripheral intrusion. Intrusion
detection system (IDS) is a comprehensive and easy approach
towards detecting and analyzing any signal that is weakened and
garbled due to low signal to noise ratio (SNR). This approach
finds significant importance in applications like peripheral security
systems.
Abstract: With continuous rise of oil price, how to develop alternative energy source has become a hot topic around the world. This study discussed the dynamic characteristics of an island power system operating under random wind speed lower than nominal wind
speeds of wind turbines. The system primarily consists of three diesel engine power generation systems, three constant-speed variable-pitch wind turbines, a small hydraulic induction generation system, and lumped static loads. Detailed models based on Matlab/Simulink were developed to cater for the dynamic behavior of the system. The results suggested this island power system can operate stably in this operational mode. This study can serve as an important reference for planning, operation, and further expansion of island power systems.
Abstract: The Canadian aerospace industry faces many
challenges. One of them is the difficulty in estimating costs. In
particular, the design effort required in a project impacts resource
requirements and lead-time, and consequently the final cost. This
paper presents the findings of a case study conducted for recognized
global leader in the design and manufacturing of aircraft engines. The
study models parametric cost estimation relationships to estimate the
design effort of integrated blade-rotor low-pressure compressor fans.
Several effort drivers are selected to model the relationship.
Comparative analyses of three types of models are conducted. The
model with the best accuracy and significance in design estimation is
retained.
Abstract: The focal spot of a high intensity focused ultrasound
transducer is small. To heat a large target volume, multiple treatment spots are required. If the power of each treatment spot is fixed, it could
results in insufficient heating of initial spots and over-heating of later ones, which is caused by the thermal diffusion. Hence, to produce a
uniform heated volume, the delivered energy of each treatment spot
should be properly adjusted. In this study, we proposed an iterative, extrapolation technique to adjust the required ultrasound energy of
each treatment spot. Three different scanning pathways were used to evaluate the performance of this technique. Results indicate that by using the proposed technique, uniform heating volume could be obtained.
Abstract: Computer technology and the Internet have made a
breakthrough in the existence of data communication. This has
opened a whole new way of implementing steganography to ensure
secure data transfer. Steganography is the fine art of hiding the
information. Hiding the message in the carrier file enables the
deniability of the existence of any message at all. This paper designs
a stego machine to develop a steganographic application to hide data
containing text in a computer video file and to retrieve the hidden
information. This can be designed by embedding text file in a video
file in such away that the video does not loose its functionality using
Least Significant Bit (LSB) modification method. This method
applies imperceptible modifications. This proposed method strives
for high security to an eavesdropper-s inability to detect hidden
information.
Abstract: For micro-gyroscopes, the angular rate detection components have to oscillate forwards and backwards alternatively. An innovative design of micro-electromagnetic drive module is proposed to make a Π-type disc reciprocally and efficiently rotate within a certain of angular interval. Twelve Electromagnetic poles enclosing the thin disc are designed to provide the magnetic drive power. Isotropic etching technique is employed to fabricate the high-aspect-ratio trench, so that the contact angle of wire against trench can be increased and the potential defect of cavities and pores within the wire can be prevented. On the other hand, a Π-type thin disc is designed to conduct the pitch motion as an angular excitation, in addition to spinning, is exerted on the gyroscope. The efficacy of the micro-magnetic drive module is verified by the commercial software, Ansoft Maxewll. In comparison with the conventional planar windings in micro-scale systems, the magnetic drive force is increased by 150%.
Abstract: This paper is an exploration of the conceptual
confusion between E-learning and M-learning particularly in Africa.
Section I provides a background to the development of E-learning
and M-learning. Section II focuses on the conceptual analysis as it
applies to Africa. It is with an investigative and expansive mind that
this paper is elaborated to respond to a profound question of the
suitability of the concepts in a particular era in Africa. The aim of this
paper is therefore to shed light on which concept best suits the unique
situation of Africa in the era of cloud computing.