Abstract: Static synchronous compensator (STATCOM) is a shunt connected voltage source converter (VSC), which can affect rapid control of reactive flow in the transmission line by controlling the generated a.c. voltage. The main aim of the paper is to design a power system installed with a Static synchronous compensator (STATCOM) and demonstrates the application of the linearised Phillips-heffron model in analyzing the damping effect of the STATCOM to improve power system oscillation stability. The proposed PI controller is designed to coordinate two control inputs: Voltage of the injection bus and capacitor voltage of the STATCOM, to improve the Dynamic stability of a SMIB system .The power oscillations damping (POD) control and power system stabilizer (PSS) and their coordinated action with proposed controllers are tested. The simulation result shows that the proposed damping controllers provide satisfactory performance in terms of improvements of dynamic stability of the system.
Abstract: Cryptographic algorithms play a crucial role in the
information society by providing protection from unauthorized
access to sensitive data. It is clear that information technology will
become increasingly pervasive, Hence we can expect the emergence
of ubiquitous or pervasive computing, ambient intelligence. These
new environments and applications will present new security
challenges, and there is no doubt that cryptographic algorithms and
protocols will form a part of the solution. The efficiency of a public
key cryptosystem is mainly measured in computational overheads,
key size and bandwidth. In particular the RSA algorithm is used in
many applications for providing the security. Although the security
of RSA is beyond doubt, the evolution in computing power has
caused a growth in the necessary key length. The fact that most chips
on smart cards can-t process key extending 1024 bit shows that there
is need for alternative. NTRU is such an alternative and it is a
collection of mathematical algorithm based on manipulating lists of
very small integers and polynomials. This allows NTRU to high
speeds with the use of minimal computing power. NTRU (Nth degree
Truncated Polynomial Ring Unit) is the first secure public key
cryptosystem not based on factorization or discrete logarithm
problem. This means that given sufficient computational resources
and time, an adversary, should not be able to break the key. The
multi-party communication and requirement of optimal resource
utilization necessitated the need for the present day demand of
applications that need security enforcement technique .and can be
enhanced with high-end computing. This has promoted us to develop
high-performance NTRU schemes using approaches such as the use
of high-end computing hardware. Peer-to-peer (P2P) or enterprise
grids are proven as one of the approaches for developing high-end
computing systems. By utilizing them one can improve the
performance of NTRU through parallel execution. In this paper we
propose and develop an application for NTRU using enterprise grid
middleware called Alchemi. An analysis and comparison of its
performance for various text files is presented.
Abstract: This work focuses on analysis of classical heat transfer equation regularized with Maxwell-Cattaneo transfer law. Computer simulations are performed in MATLAB environment. Numerical experiments are first developed on classical Fourier equation, then Maxwell-Cattaneo law is considered. Corresponding equation is regularized with a balancing diffusion term to stabilize discretizing scheme with adjusted time and space numerical steps. Several cases including a convective term in model equations are discussed, and results are given. It is shown that limiting conditions on regularizing parameters have to be satisfied in convective case for Maxwell-Cattaneo regularization to give physically acceptable solutions. In all valid cases, uniform convergence to solution of initial heat equation with Fourier law is observed, even in nonlinear case.
Abstract: This paper evaluate the multilevel modulation for
different techniques such as amplitude shift keying (M-ASK), MASK,
differential phase shift keying (M-ASK-Bipolar), Quaternary
Amplitude Shift Keying (QASK) and Quaternary Polarization-ASK
(QPol-ASK) at a total bit rate of 107 Gbps. The aim is to find a costeffective
very high speed transport solution. Numerical investigation
was performed using Monte Carlo simulations. The obtained results
indicate that some modulation formats can be operated at 100Gbps
in optical communication systems with low implementation effort
and high spectral efficiency.
Abstract: Many accidents were happened because of fast driving, habitual working overtime or tired spirit. This paper presents a solution of remote warning for vehicles collision avoidance using vehicular communication. The development system integrates dedicated short range communication (DSRC) and global position system (GPS) with embedded system into a powerful remote warning system. To transmit the vehicular information and broadcast vehicle position; DSRC communication technology is adopt as the bridge. The proposed system is divided into two parts of the positioning andvehicular units in a vehicle. The positioning unit is used to provide the position and heading information from GPS module, and furthermore the vehicular unit is used to receive the break, throttle, and othersignals via controller area network (CAN) interface connected to each mechanism. The mobile hardware are built with an embedded system using X86 processor in Linux system. A vehicle is communicated with other vehicles via DSRC in non-addressed protocol with wireless access in vehicular environments (WAVE) short message protocol. From the position data and vehicular information, this paper provided a conflict detection algorithm to do time separation and remote warning with error bubble consideration. And the warning information is on-line displayed in the screen. This system is able to enhance driver assistance service and realize critical safety by using vehicular information from the neighbor vehicles.KeywordsDedicated short range communication, GPS, Control area network, Collision avoidance warning system.
Abstract: The aim of present study was to assess the effect of
glucogenic (G) and lipogenic (L) diets on blood metabolites in
Baloochi lambs. Three rumen cannulated Baloochi sheep were used
as a 3×3 Latin square design with 3 periods (28 days). Experimental
diets were a glucogenic, a lipogenic and a mixture of G and L diets
(50:50). The animals were fed diets consisted of 50% chopped alfalfa
hay and 50% concentrate. Diets were fed once daily ad libitum.
Blood samples were taken from jugular vein before the feeding, 2, 4
and 6 hour post feeding at day 27. Results indicated that β-
hydroxybutyrate (BHBA), glucose, insulin and aspartate
aminotransferase (AST) were not affected by treatments (P > 0.05).
However, lipogenic diet increased significantly activity of Alanine
aminotransferase (ALT) and concentration of non-esterified fatty acid
(NEFA) in blood plasma (P < 0.05)
Abstract: The wireless adhoc network is comprised of wireless
node which can move freely and are connected among themselves
without central infrastructure. Due to the limited transmission range
of wireless interfaces, in most cases communication has to be relayed
over intermediate nodes. Thus, in such multihop network each node
(also called router) is independent, self-reliant and capable to route
the messages over the dynamic network topology. Various protocols
are reported in this field and it is very difficult to decide the best one.
A key issue in deciding which type of routing protocol is best for
adhoc networks is the communication overhead incurred by the
protocol. In this paper STAR a table driven and DSR on demand
protocols based on IEEE 802.11 are analyzed for their performance
on different performance measuring metrics versus varying traffic
CBR load using QualNet 5.0.2 network simulator.
Abstract: Hemodialysis patients might suffer from unhealthy
care behaviors or long-term dialysis treatments. Ultimately they need
to be hospitalized. If the hospitalization rate of a hemodialysis center
is high, its quality of service would be low. Therefore, how to decrease
hospitalization rate is a crucial problem for health care. In this study
we combined temporal abstraction with data mining techniques for
analyzing the dialysis patients' biochemical data to develop a decision
support system. The mined temporal patterns are helpful for clinicians
to predict hospitalization of hemodialysis patients and to suggest them
some treatments immediately to avoid hospitalization.
Abstract: This paper presents design features of a rescue robot, named CEO Mission II. Its body is designed to be the track wheel type with double front flippers for climbing over the collapse and the rough terrain. With 125 cm. long, 5-joint mechanical arm installed on the robot body, it is deployed not only for surveillance from the top view but also easier and faster access to the victims to get their vital signs. Two cameras and sensors for searching vital signs are set up at the tip of the multi-joint mechanical arm. The third camera is at the back of the robot for driving control. Hardware and software of the system, which controls and monitors the rescue robot, are explained. The control system is used for controlling the robot locomotion, the 5-joint mechanical arm, and for turning on/off devices. The monitoring system gathers all information from 7 distance sensors, IR temperature sensors, 3 CCD cameras, voice sensor, robot wheels encoders, yawn/pitch/roll angle sensors, laser range finder and 8 spare A/D inputs. All sensors and controlling data are communicated with a remote control station via IEEE 802.11b Wi-Fi. The audio and video data are compressed and sent via another IEEE 802.11g Wi-Fi transmitter for getting real-time response. At remote control station site, the robot locomotion and the mechanical arm are controlled by joystick. Moreover, the user-friendly GUI control program is developed based on the clicking and dragging method to easily control the movement of the arm. Robot traveling map is plotted from computing the information of wheel encoders and the yawn/pitch data. 2D Obstacle map is plotted from data of the laser range finder. The concept and design of this robot can be adapted to suit many other applications. As the Best Technique awardee from Thailand Rescue Robot Championship 2006, all testing results are satisfied.
Abstract: Worldwide many electrical equipment insulation
failures have been reported caused by switching operations, while
those equipments had previously passed all the standard tests and
complied with all quality requirements. The problem is mostly
associated with high-frequency overvoltages generated during
opening or closing of a switching device. The transients generated
during switching operations in a Gas Insulated Substation (GIS) are
associated with high frequency components in the order of few tens
of MHz.
The frequency spectrum of the VFTO generated in the 220/66 kV
Wadi-Hoff GIS is analyzed using Fast Fourier Transform technique.
The main frequency with high voltage amplitude due to the operation
of disconnector (DS5) is 5 to 10 MHz, with the highest amplitude at 9
MHz. The main frequency with high voltage amplitude due to the
operation of circuit breaker (CB5) is 1 to 25 MHz, with the highest
amplitude at 2 MHz.
Mitigating techniques damped the oscillating frequencies
effectively. The using of cable terminal reduced the frequency
oscillation effectively than that of OHTL terminal. The using of a
shunt capacitance results in vanishing the high frequency
components. Ferrite rings reduces the high frequency components
effectively especially in the range 2 to 7 MHz. The using of RC and
RL filters results in vanishing the high frequency components.
Abstract: Proxy signature helps the proxy signer to sign
messages on behalf of the original signer. It is very useful when
the original signer (e.g. the president of a company) is not
available to sign a specific document. If the original signer can
not forge valid proxy signatures through impersonating the proxy
signer, it will be robust in a virtual environment; thus the original
signer can not shift any illegal action initiated by herself to the
proxy signer. In this paper, we propose a new proxy signature
scheme. The new scheme can prevent the original signer from
impersonating the proxy signer to sign messages. The proposed
scheme is based on the regular ElGamal signature. In addition,
the fair privacy of the proxy signer is maintained. That means,
the privacy of the proxy signer is preserved; and the privacy can
be revealed when it is necessary.
Abstract: This paper proposes a novel system for monitoring the
health of underground pipelines. Some of these pipelines transport
dangerous contents and any damage incurred might have catastrophic
consequences. However, most of these damage are unintentional and
usually a result of surrounding construction activities. In order to
prevent these potential damages, monitoring systems are
indispensable. This paper focuses on acoustically recognizing road
cutters since they prelude most construction activities in modern
cities. Acoustic recognition can be easily achieved by installing a
distributed computing sensor network along the pipelines and using
smart sensors to “listen" for potential threat; if there is a real threat,
raise some form of alarm. For efficient pipeline monitoring, a novel
monitoring approach is proposed. Principal Component Analysis
(PCA) was studied and applied. Eigenvalues were regarded as the
special signature that could characterize a sound sample, and were
thus used for the feature vector for sound recognition. The denoising
ability of PCA could make it robust to noise interference. One class
SVM was used for classifier. On-site experiment results show that the
proposed PCA and SVM based acoustic recognition system will be
very effective with a low tendency for raising false alarms.
Abstract: This paper presents the development of analysis tools
for Home Agriculture project. The tools are required for monitoring
the condition of greenhouse which involves two components:
measurement hardware and data analysis engine. Measurement
hardware is functioned to measure environment parameters such as
temperature, humidity, air quality, dust and etc while analysis tool is
used to analyse and interpret the integrated data against the condition
of weather, quality of health, irradiance, quality of soil and etc. The
current development of the tools is completed for off-line data
recorded technique. The data is saved in MMC and transferred via
ZigBee to Environment Data Manager (EDM) for data analysis.
EDM converts the raw data and plot three combination graphs. It has
been applied in monitoring three months data measurement for
irradiance, temperature and humidity of the greenhouse..
Abstract: TELMES project aims to develop a securized
multimedia system devoted to medical consultation teleservices. It
will be finalized with a pilot system for a regional telecenters
network that connects local telecenters, having as support
multimedia platforms. This network will enable the implementation
of complex medical teleservices (teleconsulations, telemonitoring,
homecare, urgency medicine, etc.) for a broader range of patients
and medical professionals, mainly for family doctors and those
people living in rural or isolated regions. Thus, a multimedia,
scalable network, based on modern IT&C paradigms, will result. It
will gather two inter-connected regional telecenters, in Iaşi and
Piteşti, Romania, each of them also permitting local connections of
hospitals, diagnostic and treatment centers, as well as local networks
of family doctors, patients, even educational entities. As
communications infrastructure, we aim to develop a combined fixmobile-
internet (broadband) links. Other possible communication
environments will be GSM/GPRS/3G and radio waves. The
electrocardiogram (ECG) acquisition, internet transmission and
local analysis, using embedded technologies, was already
successfully done for patients- telemonitoring.
Abstract: This paper describes the development of a control
system model using a graphical software tool. This control system is
part of an operator training simulator developed for the National
Training Center for Operators of Ixtapantongo (CNCAOI, acronym
according to its name in Spanish language) of the Mexico-s Federal
Commission of Electricity, CFE). The Department of Simulation of
the Electrical Research Institute (IIE) developed this simulator using
as reference the Unit I of the Combined Cycle Power Plant El Sauz,
located at the centre of Mexico. The first step in the project was the
developing of the Gas Turbine System and its control system
simulator. The Turbo Gas simulator was finished and delivered to
CNCAOI in March 2007 for commercial operation. This simulator is
a high-fidelity real time dynamic simulator built and tested for
accurate operation over the entire load range. The simulator was used
primarily for operator training although it has been used for
procedure development and evaluation of plant transients.
Abstract: Previously, harmonic parameters (HPs) have been
selected as features extracted from EEG signals for automatic sleep
scoring. However, in previous studies, only one HP parameter was
used, which were directly extracted from the whole epoch of EEG
signal.
In this study, two different transformations were applied to extract
HPs from EEG signals: Hilbert-Huang transform (HHT) and wavelet
transform (WT). EEG signals are decomposed by the two
transformations; and features were extracted from different
components. Twelve parameters (four sets of HPs) were extracted.
Some of the parameters are highly diverse among different stages.
Afterward, HPs from two transformations were used to building a
rough sleep stages scoring model using the classifier SVM. The
performance of this model is about 78% using the features obtained by
our proposed extractions. Our results suggest that these features may
be useful for automatic sleep stages scoring.
Abstract: Three-dimensional simulation of harmonic up
generation in free electron laser amplifier operating simultaneously
with a cold and relativistic electron beam is presented in steady-state
regime where the slippage of the electromagnetic wave with respect
to the electron beam is ignored. By using slowly varying envelope
approximation and applying the source-dependent expansion to wave
equations, electromagnetic fields are represented in terms of the
Hermit Gaussian modes which are well suited for the planar wiggler
configuration. The electron dynamics is described by the fully threedimensional
Lorentz force equation in presence of the realistic planar
magnetostatic wiggler and electromagnetic fields. A set of coupled
nonlinear first-order differential equations is derived and solved
numerically. The fundamental and third harmonic radiation of the
beam is considered. In addition to uniform beam, prebunched
electron beam has also been studied. For this effect of sinusoidal
distribution of entry times for the electron beam on the evolution of
radiation is compared with uniform distribution. It is shown that
prebunching reduces the saturation length substantially. For
efficiency enhancement the wiggler is set to decrease linearly when
the radiation of the third harmonic saturates. The optimum starting
point of tapering and the slope of radiation in the amplitude of
wiggler are found by successive run of the code.
Abstract: This paper presented a new approach for centralized
monitoring and self-protected against fiber fault in fiber-to-the-home
(FTTH) access network by using Smart Access Network Testing,
Analyzing and Database (SANTAD). SANTAD will be installed
with optical line terminal (OLT) at central office (CO) for in-service
transmission surveillance and fiber fault localization within FTTH
with point-to-multipoint (P2MP) configuration downwardly from CO
towards customer residential locations based on the graphical user
interface (GUI) processing capabilities of MATLAB software.
SANTAD is able to detect any fiber fault as well as identify the
failure location in the network system. SANTAD enable the status of
each optical network unit (ONU) connected line is displayed onto
one screen with capability to configure the attenuation and detect the
failure simultaneously. The analysis results and information will be
delivered to the field engineer for promptly actions, meanwhile the
failure line will be diverted to protection line to ensure the traffic
flow continuously. This approach has a bright prospect to improve
the survivability and reliability as well as increase the efficiency and
monitoring capabilities in FTTH.
Abstract: In this paper, the differential quadrature method is applied to simulate natural convection in an inclined cubic cavity using velocity-vorticity formulation. The numerical capability of the present algorithm is demonstrated by application to natural convection in an inclined cubic cavity. The velocity Poisson equations, the vorticity transport equations and the energy equation are all solved as a coupled system of equations for the seven field variables consisting of three velocities, three vorticities and temperature. The coupled equations are simultaneously solved by imposing the vorticity definition at boundary without requiring the explicit specification of the vorticity boundary conditions. Test results obtained for an inclined cubic cavity with different angle of inclinations for Rayleigh number equal to 103, 104, 105 and 106 indicate that the present coupled solution algorithm could predict the benchmark results for temperature and flow fields. Thus, it is convinced that the present formulation is capable of solving coupled Navier-Stokes equations effectively and accurately.
Abstract: Wavelet transform has been extensively used in
machine fault diagnosis and prognosis owing to its strength to deal
with non-stationary signals. The existing Wavelet transform based
schemes for fault diagnosis employ wavelet decomposition of the
entire vibration frequency which not only involve huge
computational overhead in extracting the features but also increases
the dimensionality of the feature vector. This increase in the
dimensionality has the tendency to 'over-fit' the training data and
could mislead the fault diagnostic model. In this paper a novel
technique, envelope wavelet packet transform (EWPT) is proposed in
which features are extracted based on wavelet packet transform of the
filtered envelope signal rather than the overall vibration signal. It not
only reduces the computational overhead in terms of reduced number
of wavelet decomposition levels and features but also improves the
fault detection accuracy. Analytical expressions are provided for the
optimal frequency resolution and decomposition level selection in
EWPT. Experimental results with both actual and simulated machine
fault data demonstrate significant gain in fault detection ability by
EWPT at reduced complexity compared to existing techniques.