Abstract: Having done in this study, air-conditioning
automation for patisserie shopwindow was designed. In the cooling
sector it is quite important to cooling up the air temperature in the
shopwindow within short time interval. Otherwise the patisseries
inside of the shopwindow will be spoilt in a few days. Additionally
the humidity is other important parameter for the patisseries kept in
shopwindow. It must be raised up to desired level in a quite short
time. Traditional patisserie shopwindows only allow controlling
temperature manually. There is no humidity control and humidity is
supplied by fans that are directed to the water at the bottom of the
shopwindows. In this study, humidity and temperature sensors
(SHT11), PIC, AC motor controller, DC motor controller, ultrasonic
nebulizer and other electronic circuit members were used to simulate
air conditioning automation for patisserie shopwindow in proteus
software package. The simulation results showed that temperature
and humidity values are adjusted in desired time duration by openloop
control technique. Outer and inner temperature and humidity
values were used for control mechanism.
Abstract: Wireless sensor network has recently emerged as enablers
of several areas. Real applications of WSN are being explored
and some of them are yet to come. While the potential of sensor
networks has been only beginning to be realized, several challenges
still remain. One of them is the experimental evaluation of WSN.
Therefore, deploying and operating a testbed to study the real
behavior of WSN become more and more important. The main
contribution of this work is to analysis the RF link budget behavior
of wireless sensor networks in underground mine gallery.
Abstract: Now-a-days, numbers of simulation software are
being used all over the world to solve Computational Fluid
Dynamics (CFD) related problems. In this present study, a
commercial CFD simulation software namely STAR-CCM+ is
applied to analyze the airflow characteristics inside a 2.5" hard
disk drive. Each step of the software is described adequately to
obtain the output and the data are verified with the theories to
justify the robustness of the simulation outcome. This study
gives an insight about the accuracy level of the CFD
simulation software to compute CFD related problems
although it largely depends upon the computer speed. Also
this study will open avenues for further research.
Abstract: As there are also graph methods of circuit analysis in
addition to algebraic methods, it is, in theory, clearly possible to
carry out an analysis of a whole switched circuit in two-phase
switching exclusively by the graph method as well. This article deals
with two methods of full-graph solving of switched circuits: by
transformation graphs and by two-graphs. It deals with the circuit
switched capacitors and the switched current, too. All methods are
presented in an equally detailed steps to be able to compare.
Abstract: An on-demand routing protocol for wireless ad hoc
networks is one that searches for and attempts to discover a route to
some destination node only when a sending node originates a data
packet addressed to that node. In order to avoid the need for such a
route discovery to be performed before each data packet is sent, such
routing protocols must cache routes previously discovered. This
paper presents an analysis of the effect of intelligent caching in a non
clustered network, using on-demand routing protocols in wireless ad
hoc networks. The analysis carried out is based on the Dynamic
Source Routing protocol (DSR), which operates entirely on-demand.
DSR uses the cache in every node to save the paths that are learnt
during route discovery procedure. In this implementation, caching
these paths only at intermediate nodes and using the paths from these
caches when required is tried. This technique helps in storing more
number of routes that are learnt without erasing the entries in the
cache, to store a new route that is learnt.
The simulation results on DSR have shown that this technique
drastically increases the available memory for caching the routes
discovered without affecting the performance of the DSR routing
protocol in any way, except for a small increase in end to end delay.
Abstract: Insulation used in transformer is mostly oil pressboard insulation. Insulation failure is one of the major causes of catastrophic failure of transformers. It is established that partial discharges (PD) cause insulation degradation and premature failure of insulation. Online monitoring of PDs can reduce the risk of catastrophic failure of transformers. There are different techniques of partial discharge measurement like, electrical, optical, acoustic, opto-acoustic and ultra high frequency (UHF). Being non invasive and non interference prone, acoustic emission technique is advantageous for online PD measurement. Acoustic detection of p.d. is based on the retrieval and analysis of mechanical or pressure signals produced by partial discharges. Partial discharges are classified according to the origin of discharges. Their effects on insulation deterioration are different for different types. This paper reports experimental results and analysis for classification of partial discharges using acoustic emission signal of laboratory simulated partial discharges in oil pressboard insulation system using three different electrode systems. Acoustic emission signal produced by PD are detected by sensors mounted on the experimental tank surface, stored on an oscilloscope and fed to computer for further analysis. The measured AE signals are analyzed using discrete wavelet transform analysis and wavelet packet analysis. Energy distribution in different frequency bands of discrete wavelet decomposed signal and wavelet packet decomposed signal is calculated. These analyses show a distinct feature useful for PD classification. Wavelet packet analysis can sort out any misclassification arising out of DWT in most cases.
Abstract: This paper presents an optimized algorithm for robot localization which increases the correctness and accuracy of the estimating position of mobile robot to more than 150% of the past methods [1] in the uncertain and noisy environment. In this method the odometry and vision sensors are combined by an adapted well-known discrete kalman filter [2]. This technique also decreased the computation process of the algorithm by DKF simple implementation. The experimental trial of the algorithm is performed on the robocup middle size soccer robot; the system can be used in more general environments.
Abstract: The neural stimulation has been gaining much interest in neuromodulation research and clinical trials. For efficiency, there is a need for variable electrical stimulation such as current and voltage stimuli as well as wireless framework. In this regard, we develop the wireless neural stimulator capable of voltage and current stimuli. The system consists of ZigBee which is a wireless communication module and stimulus generator. The stimulus generator with 8-bits resolution enable both mono-polar and bi-polar waveform in voltage (-3.3~3.3V) and current(-330~330µA) stimulus mode which is controllable. The experimental results suggest that the proposed neural stimulator can play a role as an effective approach for neuromodulation.
Abstract: This study investigates the performance of radial basis function networks (RBFN) in forecasting the monthly CO2 emissions of an electric power utility. We also propose a method for input variable selection. This method is based on identifying the general relationships between groups of input candidates and the output. The effect that each input has on the forecasting error is examined by removing all inputs except the variable to be investigated from its group, calculating the networks parameter and performing the forecast. Finally, the new forecasting error is compared with the reference model. Eight input variables were identified as the most relevant, which is significantly less than our reference model with 30 input variables. The simulation results demonstrate that the model with the 8 inputs selected using the method introduced in this study performs as accurate as the reference model, while also being the most parsimonious.
Abstract: ''Cocktail party problem'' is well known as one of the human auditory abilities. We can recognize the specific sound that we want to listen by this ability even if a lot of undesirable sounds or noises are mixed. Blind source separation (BSS) based on independent component analysis (ICA) is one of the methods by which we can separate only a special signal from their mixed signals with simple hypothesis. In this paper, we propose an online approach for blind source separation using the sliding DFT and the time domain independent component analysis. The proposed method can reduce calculation complexity in comparison with conventional methods, and can be applied to parallel processing by using digital signal processors (DSPs) and so on. We evaluate this method and show its availability.
Abstract: On the basis of the linearized Phillips-Herffron model of a single-machine power system, a novel method for designing unified power flow controller (UPFC) based output feedback controller is presented. The design problem of output feedback controller for UPFC is formulated as an optimization problem according to with the time domain-based objective function which is solved by iteration particle swarm optimization (IPSO) that has a strong ability to find the most optimistic results. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The simulation results prove the effectiveness and robustness of the proposed method in terms of a high performance power system. The simulation study shows that the designed controller by Iteration PSO performs better than Classical PSO in finding the solution.
Abstract: An approach to develop the FPGA of a flexible key
RSA encryption engine that can be used as a standard device in the
secured communication system is presented. The VHDL modeling of
this RSA encryption engine has the unique characteristics of
supporting multiple key sizes, thus can easily be fit into the systems
that require different levels of security. A simple nested loop addition
and subtraction have been used in order to implement the RSA
operation. This has made the processing time faster and used
comparatively smaller amount of space in the FPGA. The hardware
design is targeted on Altera STRATIX II device and determined that
the flexible key RSA encryption engine can be best suited in the
device named EP2S30F484C3. The RSA encryption implementation
has made use of 13,779 units of logic elements and achieved a clock
frequency of 17.77MHz. It has been verified that this RSA
encryption engine can perform 32-bit, 256-bit and 1024-bit
encryption operation in less than 41.585us, 531.515us and 790.61us
respectively.
Abstract: Robot manipulators are highly coupled nonlinear
systems, therefore real system and mathematical model of dynamics
used for control system design are not same. Hence, fine-tuning of
controller is always needed. For better tuning fast simulation speed
is desired. Since, Matlab incorporates LAPACK to increase the speed
and complexity of matrix computation, dynamics, forward and
inverse kinematics of PUMA 560 is modeled on Matlab/Simulink in
such a way that all operations are matrix based which give very less
simulation time. This paper compares PID parameter tuning using
Genetic Algorithm, Simulated Annealing, Generalized Pattern Search
(GPS) and Hybrid Search techniques. Controller performances for all
these methods are compared in terms of joint space ITSE and
cartesian space ISE for tracking circular and butterfly trajectories.
Disturbance signal is added to check robustness of controller. GAGPS
hybrid search technique is showing best results for tuning PID
controller parameters in terms of ITSE and robustness.
Abstract: The incorporation of renewable energy sources for the sustainable electricity production is undertaking a more prominent role in electric power systems. Thus, it will be an indispensable incident that the characteristics of future power networks, their prospective stability for instance, get influenced by the imposed features of sustainable energy sources. One of the distinctive attributes of the sustainable energy sources is exhibiting the stochastic behavior. This paper investigates the impacts of this stochastic behavior on the small disturbance rotor angle stability in the upcoming electric power networks. Considering the various types of renewable energy sources and the vast variety of system configurations, the sensitivity analysis can be an efficient breakthrough towards generalizing the effects of new energy sources on the concept of stability. In this paper, the definition of small disturbance angle stability for future power systems and the iterative-stochastic way of its analysis are presented. Also, the effects of system parameters on this type of stability are described by performing a sensitivity analysis for an electric power test system.
Abstract: The protection of parallel transmission lines has been a challenging task due to mutual coupling between the adjacent circuits of the line. This paper presents a novel scheme for detection and classification of faults on parallel transmission lines. The proposed approach uses combination of wavelet transform and neural network, to solve the problem. While wavelet transform is a powerful mathematical tool which can be employed as a fast and very effective means of analyzing power system transient signals, artificial neural network has a ability to classify non-linear relationship between measured signals by identifying different patterns of the associated signals. The proposed algorithm consists of time-frequency analysis of fault generated transients using wavelet transform, followed by pattern recognition using artificial neural network to identify the type of the fault. MATLAB/Simulink is used to generate fault signals and verify the correctness of the algorithm. The adaptive discrimination scheme is tested by simulating different types of fault and varying fault resistance, fault location and fault inception time, on a given power system model. The simulation results show that the proposed scheme for fault diagnosis is able to classify all the faults on the parallel transmission line rapidly and correctly.
Abstract: Study on suppression of interference in time domain equalizers is attempted for high data rate impulse radio (IR) ultra wideband communication system. The narrow band systems may cause interference with UWB devices as it is having very low transmission power and the large bandwidth. SRAKE receiver improves system performance by equalizing signals from different paths. This enables the use of SRAKE receiver techniques in IRUWB systems. But Rake receiver alone fails to suppress narrowband interference (NBI). A hybrid SRake-MMSE time domain equalizer is proposed to overcome this by taking into account both the effect of the number of rake fingers and equalizer taps. It also combats intersymbol interference. A semi analytical approach and Monte-Carlo simulation are used to investigate the BER performance of SRAKEMMSE receiver on IEEE 802.15.3a UWB channel models. Study on non-line of sight indoor channel models (both CM3 and CM4) illustrates that bit error rate performance of SRake-MMSE receiver with NBI performs better than that of Rake receiver without NBI. We show that for a MMSE equalizer operating at high SNR-s the number of equalizer taps plays a more significant role in suppressing interference.
Abstract: The induction hardening machines are utilized in
the industries which modify machine parts and tools needed to
achieve high ware resistance. This paper describes the model of
induction heating process design of inverter circuit and the results
of induction surface hardening of heating coil. In the design of
heating coil, the shape and the turn numbers of the coil are very
important design factors because they decide the overall operating
performance of induction heater including resonant frequency, Q
factor, efficiency and power factor. The performance will be tested
by experiments in some cases high frequency induction hardening
machine.
Abstract: In this paper, an experimentation to enhance the
visibility of hot objects in a thermal image acquired with ordinary
digital camera is reported, after the applications of lowpass and
median filters to suppress the distracting granular noises. The
common thresholding and slicing techniques were used on the
histogram at different gray levels, followed by a subjective
comparative evaluation. The best result came out with the threshold
level 115 and the number of slices 3.
Abstract: In this paper, a system level behavioural model for RF
power amplifier, which exhibits memory effects, and based on multibranch
system is proposed. When higher order terms are included,
the memory polynomial model (MPM) exhibits numerical
instabilities. A set of memory orthogonal polynomial model
(OMPM) is introduced to alleviate the numerical instability problem
associated to MPM model. A data scaling and centring algorithm was
applied to improve the power amplifier modeling accuracy.
Simulation results prove that the numerical instability can be greatly
reduced, as well as the model precision improved with nonlinear
model.
Abstract: Tracing and locating the geographical location of users (Geolocation) is used extensively in todays Internet. Whenever we, e.g., request a page from google we are - unless there was a specific configuration made - automatically forwarded to the page with the relevant language and amongst others, dependent on our location identified, specific commercials are presented. Especially within the area of Network Security, Geolocation has a significant impact. Because of the way the Internet works, attacks can be executed from almost everywhere. Therefore, for an attribution, knowledge of the origination of an attack - and thus Geolocation - is mandatory in order to be able to trace back an attacker. In addition, Geolocation can also be used very successfully to increase the security of a network during operation (i.e. before an intrusion actually has taken place). Similar to greylisting in emails, Geolocation allows to (i) correlate attacks detected with new connections and (ii) as a consequence to classify traffic a priori as more suspicious (thus particularly allowing to inspect this traffic in more detail). Although numerous techniques for Geolocation are existing, each strategy is subject to certain restrictions. Following the ideas of Endo et al., this publication tries to overcome these shortcomings with a combined solution of different methods to allow improved and optimized Geolocation. Thus, we present our architecture for improved Geolocation, by designing a new algorithm, which combines several Geolocation techniques to increase the accuracy.