Abstract: The resistive-inductive-capacitive behavior of long
interconnects which are driven by CMOS gates are presented in this
paper. The analysis is based on the ¤Ç-model of a RLC load and is
developed for submicron devices. Accurate and analytical
expressions for the output load voltage, the propagation delay and the
short circuit power dissipation have been proposed after solving a
system of differential equations which accurately describe the
behavior of the circuit. The effect of coupling capacitance between
input and output and the short circuit current on these performance
parameters are also incorporated in the proposed model. The
estimated proposed delay and short circuit power dissipation are in
very good agreement with the SPICE simulation with average
relative error less than 6%.
Abstract: This research paper presents some methods to assess the performance of Wigner Ville Distribution for Time-Frequency representation of non-stationary signals, in comparison with the other representations like STFT, Spectrogram etc. The simultaneous timefrequency resolution of WVD is one of the important properties which makes it preferable for analysis and detection of linear FM and transient signals. There are two algorithms proposed here to assess the resolution and to compare the performance of signal detection. First method is based on the measurement of area under timefrequency plot; in case of a linear FM signal analysis. A second method is based on the instantaneous power calculation and is used in case of transient, non-stationary signals. The implementation is explained briefly for both methods with suitable diagrams. The accuracy of the measurements is validated to show the better performance of WVD representation in comparison with STFT and Spectrograms.
Abstract: Demand of energy is increasing faster than the
generation. It leads shortage of power in all sectors of society. At
peak hours this shortage is higher. Unless we utilize energy efficient
technology, it is very difficult to minimize the shortage of energy. So
energy efficiency program and energy conservation has an important
role. Energy efficient technologies are cost intensive hence it is
always not possible to implement in country like India. In the recent
study, an educational building with operating hours from 10:00 a.m.
to 05:00 p.m. has been selected to quantify the possibility of lighting
energy conservation. As the operating hour is in daytime, integration
of daylight with artificial lighting system will definitely reduce the
lighting energy consumption. Moreover the initial investment has
been given priority and hence the existing lighting installation was
unaltered. An automatic controller has been designed which will be
operated as a function of daylight through windows and the lighting
system of the room will function accordingly. The result of the study
of integrating daylight gave quite satisfactory for visual comfort as
well as energy conservation.
Abstract: This paper presents Genetic Algorithm (GA) based
approach for the allocation of FACTS (Flexible AC Transmission
System) devices for the improvement of Power transfer capacity in an
interconnected Power System. The GA based approach is applied on
IEEE 30 BUS System. The system is reactively loaded starting from
base to 200% of base load. FACTS devices are installed in the
different locations of the power system and system performance is
noticed with and without FACTS devices. First, the locations, where
the FACTS devices to be placed is determined by calculating active
and reactive power flows in the lines. Genetic Algorithm is then
applied to find the amount of magnitudes of the FACTS devices. This
approach of GA based placement of FACTS devices is tremendous
beneficial both in terms of performance and economy is clearly
observed from the result obtained.
Abstract: Recent advances in wireless sensor networks have led
to many routing methods designed for energy-efficiency in wireless
sensor networks. Despite that many routing methods have been
proposed in USN, a single routing method cannot be energy-efficient
if the environment of the ubiquitous sensor network varies. We present
the controlling network access to various hosts and the services they
offer, rather than on securing them one by one with a network security
model. When ubiquitous sensor networks are deployed in hostile
environments, an adversary may compromise some sensor nodes and
use them to inject false sensing reports. False reports can lead to not
only false alarms but also the depletion of limited energy resource in
battery powered networks. The interleaved hop-by-hop authentication
scheme detects such false reports through interleaved authentication.
This paper presents a LMDD (Low energy method for data delivery)
algorithm that provides energy-efficiency by dynamically changing
protocols installed at the sensor nodes. The algorithm changes
protocols based on the output of the fuzzy logic which is the fitness
level of the protocols for the environment.
Abstract: The utilize of renewable energy sources becomes
more crucial and fascinatingly, wider application of renewable
energy devices at domestic, commercial and industrial levels is not
only affect to stronger awareness but also significantly installed
capacities. Moreover, biomass principally is in form of woods and
converts to be energy for using by humans for a long time.
Gasification is a process of conversion of solid carbonaceous fuel
into combustible gas by partial combustion. Many gasified models
have various operating conditions because the parameters kept in
each model are differentiated. This study applied the experimental
data including three inputs variables including biomass consumption;
temperature at combustion zone and ash discharge rate and gas flow
rate as only one output variable. In this paper, response surface
methods were applied for identification of the gasified system
equation suitable for experimental data. The result showed that linear
model gave superlative results.
Abstract: In this paper, an accurate theoretical analysis for the achievable average channel capacity (in the Shannon sense) per user of a hybrid cellular direct-sequence/fast frequency hopping code-division multiple-access (DS/FFH-CDMA) system operating in a Rayleigh fading environment is presented. The analysis covers the downlink operation and leads to the derivation of an exact mathematical expression between the normalized average channel capacity available to each system-s user, under simultaneous optimal power and rate adaptation and the system-s parameters, as the number of hops per bit, the processing gain applied, the number of users per cell and the received signal-tonoise power ratio over the signal bandwidth. Finally, numerical results are presented to illustrate the proposed mathematical analysis.
Abstract: This paper presents a new optimization technique based on quantum computing principles to solve a security constrained power system economic dispatch problem (SCED). The proposed technique is a population-based algorithm, which uses some quantum computing elements in coding and evolving groups of potential solutions to reach the optimum following a partially directed random approach. The SCED problem is formulated as a constrained optimization problem in a way that insures a secure-economic system operation. Real Coded Quantum-Inspired Evolution Algorithm (RQIEA) is then applied to solve the constrained optimization formulation. Simulation results of the proposed approach are compared with those reported in literature. The outcome is very encouraging and proves that RQIEA is very applicable for solving security constrained power system economic dispatch problem (SCED).
Abstract: In an Orthogonal Frequency Division Multiplexing (OFDM) systems, the Peak to Average power Ratio (PAR) is high. The clipping signal scheme is a useful and simple method to reduce the PAR. However, it introduces additional noise that degrades the systems performance. We propose an oversampling scheme to deal with the received signal in order to reduce the clipping noise by using Finite Impulse Response (FIR) filter. Coefficients of filter are obtained by correlation function of the received signal and the oversampling information at receiver. The performance of the proposed technique is evaluated for frequency selective channel. Results show that the proposed scheme can mitigate the clipping noise significantly for OFDM systems and in order to maintain the system's capacity, the clipping ratio should be larger than 2.5.
Abstract: This article experimentally investigates the
thermal performance of thermoelectric air-cooling module
which comprises a thermoelectric cooler (TEC) and an
air-cooling heat sink. The influences of input current and heat
load are determined. And performances under each situation
are quantified by thermal resistance analysis. Since TEC
generates Joule heat, this nature makes construction of thermal
resistance network difficult. To simplify the analysis, this
article emphasizes on the resistance heat load might meet when
passing through the device. Therefore, the thermal resistances
in this paper are to divide temperature differences by heat load.
According to the result, there exists an optimum input current
under every heating power. In this case, the optimum input
current is around 6A or 7A. The performance of the heat sink
would be improved with TEC under certain heating power and
input current, especially at a low heat load. According to the
result, the device can even make the heat source cooler than the
ambient. However, TEC is not always effective at every heat
load and input current. In some situation, the device works
worse than the heat sink without TEC. To determine the
availability of TEC, this study figures out the effective
operating region in which the TEC air-cooling module works
better than the heat sink without TEC. The result shows that
TEC is more effective at a lower heat load. If heat load is too
high, heat sink with TEC will perform worse than without TEC.
The limit of this device is 57W. Besides, TEC is not helpful if
input current is too high or too low. There is an effective range
of input current, and the range becomes narrower when the heat
load grows.
Abstract: The three-time-scale plant model of a wind power
generator, including a wind turbine, a flexible vertical shaft, a Variable
Inertia Flywheel (VIF) module, an Active Magnetic Bearing (AMB)
unit and the applied wind sequence, is constructed. In order to make
the wind power generator be still able to operate as the spindle speed
exceeds its rated speed, the VIF is equipped so that the spindle speed
can be appropriately slowed down once any stronger wind field is
exerted. To prevent any potential damage due to collision by shaft
against conventional bearings, the AMB unit is proposed to regulate
the shaft position deviation. By singular perturbation order-reduction
technique, a lower-order plant model can be established for the
synthesis of feedback controller. Two major system parameter
uncertainties, an additive uncertainty and a multiplicative uncertainty,
are constituted by the wind turbine and the VIF respectively.
Frequency Shaping Sliding Mode Control (FSSMC) loop is proposed
to account for these uncertainties and suppress the unmodeled
higher-order plant dynamics. At last, the efficacy of the FSSMC is
verified by intensive computer and experimental simulations for
regulation on position deviation of the shaft and counter-balance of
unpredictable wind disturbance.
Abstract: This paper presents an investigation of the power
penalties imposed by four-wave mixing (FWM) on G.652 (Single-
Mode Fiber - SMF), G.653 (Dispersion-Shifted Fiber - DSF), and
G.655 (Non-Zero Dispersion-Shifted Fiber - NZDSF) compliant
fibers, considering the DWDM grids suggested by the ITU-T
Recommendations G.692, and G.694.1, with uniform channel
spacing of 100, 50, 25, and 12.5 GHz. The mathematical/numerical
model assumes undepleted pumping, and shows very clearly the
deleterious effect of FWM on the performance of DWDM systems,
measured by the signal-to-noise ratio (SNR). The results make it
evident that non-uniform channel spacing is practically mandatory
for WDM systems based on DSF fibers.
Abstract: Magnesium is used implant material potentially for
non-toxicity to the human body. Due to the excellent
bio-compatibility, Mg alloys is applied to implants avoiding removal
second surgery. However, it is found commercial magnesium alloys
including aluminum has low corrosion resistance, resulting
subcutaneous gas bubbles and consequently the approach as
permanent bio-materials. Generally, Aluminum is known to pollution
substance, and it raises toxicity to nervous system. Therefore
especially Mg-35Zn-3Ca alloy is prepared for new biodegradable
materials in this study. And the pulsed power is used in
constant-current mode of DC power kinds of anodization. Based on
the aforementioned study, it examines corrosion resistance and
biocompatibility by effect of current and frequency variation. The
surface properties and thickness were compared using scanning
electronic microscopy. Corrosion resistance was assessed via
potentiodynamic polarization and the effect of oxide layer on the body
was assessed cell viability. Anodized Mg-35Zn-3Ca alloy has good
biocompatibility in vitro by current and frequency variation.
Abstract: This paper presents an interval-based multi-attribute
decision making (MADM) approach in support of the decision
process with imprecise information. The proposed decision
methodology is based on the model of linear additive utility function
but extends the problem formulation with the measure of composite
utility variance. A sample study concerning with the evaluation of
electric generation expansion strategies is provided showing how the
imprecise data may affect the choice toward the best solution and
how a set of alternatives, acceptable to the decision maker (DM),
may be identified with certain confidence.
Abstract: A active inductor in CMOS techonology with a supply voltage of 1.8V is presented. The value of the inductance L can be in the range from 0.12nH to 0.25nH in high frequency(HF). The proposed active inductor is designed in TSMC 0.18-um CMOS technology. The power dissipation of this inductor can retain constant at all operating frequency bands and consume around 20mW from 1.8V power supply. Inductors designed by integrated circuit occupy much smaller area, for this reason,attracted researchers attention for more than decade. In this design we used Advanced Designed System (ADS) for simulating cicuit.
Abstract: Music has a great effect on human body and mind; it
can have a positive effect on hormone system. Objective of this study
is to analysis the effect of music (carnatic, hard rock and jazz) on
brain activity during mental work load using electroencephalography
(EEG). Eight healthy subjects without special musical education
participated in the study. EEG signals were acquired at frontal (Fz),
parietal (Pz) and central (Cz) lobes of brain while listening to music
at three experimental condition (rest, music without mental task and
music with mental task). Spectral powers features were extracted at
alpha, theta and beta brain rhythms. While listening to jazz music, the
alpha and theta powers were significantly (p < 0.05) high for rest as
compared to music with and without mental task in Cz. While
listening to Carnatic music, the beta power was significantly (p <
0.05) high for with mental task as compared to rest and music
without mental task at Cz and Fz location. This finding corroborates
that attention based activities are enhanced while listening to jazz and
carnatic as compare to Hard rock during mental task.
Abstract: The design of Automatic Generation Control (AGC) system plays a vital role in automation of power system. This paper proposes Hybrid Neuro Fuzzy (HNF) approach for AGC of two-area interconnected reheat thermal power system with the consideration of Generation Rate Constraint (GRC). The advantage of proposed controller is that it can handle the system non-linearities and at the same time the proposed approach is faster than conventional controllers. The performance of HNF controller has been compared with that of both conventional Proportional Integral (PI) controller as well as Fuzzy Logic Controller (FLC) both in the absence and presence of Generation Rate Constraint (GRC). System performance is examined considering disturbance in each area of interconnected power system.
Abstract: The review performed on the condition of energy
consumption & rate in Iran, shows that unfortunately the subject of
optimization and conservation of energy in active industries of
country lacks a practical & effective method and in most factories,
the energy consumption and rate is more than in similar industries of
industrial countries. The increasing demand of electrical energy and
the overheads which it imposes on the organization, forces
companies to search for suitable approaches to optimize energy
consumption and demand management. Application of value
engineering techniques is among these approaches. Value
engineering is considered a powerful tool for improving profitability.
These tools are used for reduction of expenses, increasing profits,
quality improvement, increasing market share, performing works in
shorter durations, more efficient utilization of sources & etc.
In this article, we shall review the subject of value engineering and
its capabilities for creating effective transformations in industrial
organizations, in order to reduce energy costs & the results have
been investigated and described during a case study in Mazandaran
wood and paper industries, the biggest consumer of energy in north
of Iran, for the purpose of presenting the effects of performed tasks
in optimization of energy consumption by utilizing value engineering
techniques in one case study.
Abstract: It is impossible to think about democracy without elections. The litmus test of any electoral process in any country is the possibility of a one time minority to become a majority at another time and a peaceful transition of power. In many countries in Sub-Saharan Africa though the multi-party elections appeared to be competitive they failed the acid test of democracy: peaceful regime change in a free and fair election. Failure to solve electoral disputes might lead to bloody electoral conflicts as witnessed in many emerging democracies in Africa. The aim of this paper is to investigate electoral conflicts in Africa since the end of the Cold War by using the 2005 post-election violence in Ethiopia as a case study. In Ethiopia, the coming to power of the EPRDF in 1991 marked the fall of the Derg dictatorial military government and the beginning of a multi-party democracy. The country held multi-party parliamentary elections in 1995, 2000, and 2005 where the ruling EPRDF party “won" the elections through violence, involving intimidation, manipulation, detentions of political opponents, torture, and political assassinations. The 2005 electoral violence was the worst electoral violence in the country-s political history that led to the death of 193 protestors and the imprisonment of more than 40, 000 people. It is found out that the major causes of the 2005 Ethiopian election were the defeat of the ruling party in the election and its attempt to reverse the poll results by force; the Opposition-s lack of decisive leadership; the absence of independent courts and independent electoral management body; and the ruling party-s direct control over the army and police.
Abstract: Direct search methods are evolutionary algorithms used to solve optimization problems. (DS) methods do not require any information about the gradient of the objective function at hand while searching for an optimum solution. One of such methods is Pattern Search (PS) algorithm. This paper presents a new approach based on a constrained pattern search algorithm to solve a security constrained power system economic dispatch problem (SCED). Operation of power systems demands a high degree of security to keep the system satisfactorily operating when subjected to disturbances, while and at the same time it is required to pay attention to the economic aspects. Pattern recognition technique is used first to assess dynamic security. Linear classifiers that determine the stability of electric power system are presented and added to other system stability and operational constraints. The problem is formulated as a constrained optimization problem in a way that insures a secure-economic system operation. Pattern search method is then applied to solve the constrained optimization formulation. In particular, the method is tested using one system. Simulation results of the proposed approach are compared with those reported in literature. The outcome is very encouraging and proves that pattern search (PS) is very applicable for solving security constrained power system economic dispatch problem (SCED).