Theses supervised by Yrd. Doç. Dr. Murat Aksoy
11 theses · Çukurova University
Ultra-short pulse propagation in single mode optical fiber
The propagation of short pulses in single mode optical fibers is affected by a number of linear and nonlinear effects. The influence of different effects on pulse propagation depends on the pulse power and width and the fiber properties. Picosecond pulse propagation at wavelengths far from the dispersion minimum is described by the effects of the group velocity dispersion and the refractive-index nonlinearity. Stable pulse-propagation without changes of pulse spectral and temporal shapes can exist as a result of the cancellation of the effect of pulse broadening through dispersion by the refractive index nonlinearity. Solitary waves pass through one another without deformations due to the collisions. The optical soliton in fibers is the solitary wave of an envelope of a light wave. The optical soliton belongs to an envelope soliton. The pulse shape represents an envelope of a light wave. An envelope of a wave which propagates in a strongly dispersive nonlinear medium,in which the wave property depends on the amplitude as well as on the wavelength of the wave, has a solitary wave solution had been known for waves in plasmas. In our simulation we will investigate pulse propagation in single- mode optical fibers. We will analyze the influence of different effects on pulse propagation. In this analysis, we will use nonlinear schrodinger equation which describes soliton wave and split-step fourier method to solve this equation. These effects depend on the pulse power and width and also linear and nonlinear fiber properties. Keywords : Ultra-short pulse propagation, single mode optical fiber, refractive index, soliton, nonlinear schrodinger equation, split-step fourier method.
Developing a software to determine the microcontroller specifications for fuzzy logic control applications
In recent years, the Fuzzy Logic Control Systems (FLCSs) have becomewidespread and their application areas have also extended. There are numeroussoftwares developed to use in design of Fuzzy Logic Control Systems. Some of themare given in previous works section.In this study, a Windows operating system based, user-friendly software todetermine the optimum microcontroller specifications for Fuzzy Logic Controlapplications is developed. With this software the optimum microcontroller might bechosen. Regarding to performance and cost effectiveness, the best solutions mightalso be provided. Besides, the microcontroller selection criteria is defined andformulated after studying various applications in different fields. According to this,an algorithm, which forms the fundamentals of the software, is composed. Thesoftware, which is developed by ?Microsoft Visual Basic? visual programminglanguage, computes the minimum performance and capacity values for the intendedapplication by using the parameters, which are defined by the user and display theoptimum microcontroller specifications.Keywords: Fuzzy Systems, Fuzzy Logic Controllers, Microcontroller for FuzzyLogic Control, Software for Fuzzy Logic Control Systems, Microsoft Visual Basic
Neural network-based ultrasonic level measurement of fluids
This thesis describes the practical implementation of neural network-based ultrasonic level measurement of fluids (in the range of cm to meters) and will be designed a neural network-based ultrasonic range finder sensor for this goal. By a neural network algorithm, this sensor can be advanced including temperature, humidity, and other parameters (such as pressure, CO2 in medium). A Multi Layer Perceptron (MLP) neural network (NN), and Back-Propagation Algorithm which is used as common for it?s learning is used in this thesis is . MLP NN is designed by Matlab Neural Network Toolbox. Necessary input-output data set for training and test of MLP NN is obtained using the approximate formula published in JASA [1993] by Owen Cramer Hardware interface uses an Atmel Atmega32 8-bit AVR microcontroller to facilitate the generation of 40 kHz signal burst which is used in the transmitter circuit, and also to process the received signal for measuring the time of flight of reflected waves and exact distance of the obstruction. Level of fluids is momentarily calculated by flight time and speed of reference sound. Temperature and Humidity Sensor (SHT11) provides temperature and humidity data to microcontroller. These data are the inputs of MLP. The outputs of MLP are values of corrected level of fluids. In this project, The program for this device is developed in MCS Electronic / BASCOM-AVR IDE.
SIP phone application on single board computer with arm microprocessor
In this Master Thesis, the multimedia hand tools that we use in our everyday life have been studied. The applications such as image and video monitoring, internet surfing and shopping with these devices increase their usage. In addition to the applications mentioned above, a VoIP called voice communication technique, using SIP over the internet, has been investigated.In this application 32-bit microprocessor S3C2440, 64 MB Flash ROM, 64 MB SDRAM memory is utilised. For the connection of the peripherals such as the keyboard, mouse, bluetooth a USB controller is used and for the internet connection a LAN controller and a 4,3? touch-screen LCD display utilised. In addition to the hardware a listed above, a memory card is added to expand the data storage. In order to implement the voice communications conveniently over the internet, voice input&output units are added in the mini-computer.This work has been done over Windows CE 5.0 operating system using the Microsoft Platform Builder. The drivers are prepared for all hardware on board using the Microsoft Embedded Visual C++.As a result of the study, all needed hardware was run and both the multimedia features and the voice calls are implemented.
Symbolic analysis methods for switched capacitor networks
Symbolic analysis at the circuit level is a formal technique to calculate the behavior or a characteristic of a circuit with the independent variable (time or frequency), the dependent variables (voltages and currents), and (some or all of) the circuit elements represented by symbols.In this study, we consider the problem of generating simple yet accurate symbolic representation of Switched Capacitor (SC) circuit transfer function and characteristics in terms of circuit parameters for linear(ized) analog integrated circuits. Symbolic modeling and analysis of analog integrated SC circuits are simulated in MATLAB.
Hibrit elektrikli araçlar için bilgisayar modelleme ve simulasyonu
With increasing oil price and mounting environment concerns, cleaner andsustainable energy solutions have been demanded. At present transportationconstitutes a large portion of the energy consumed and pollution created. The workpresented here deals with evaluation and optimisation of the tractive system in hybridelectric buses. The work is based on analytical simulation models that are verifiedvia measurements. The subject of this thesis is the control of the load distributionbetween the power sources in the hybrid electric powertrain. The control problem isto choose the distribution of power from the electric buffer and primary power unitthat minimizes the fuel consumption in the long run. To solve this problem theefficiency characteristics of the components in the powertrain must be considered. Itis the advantage of hybrids to have the extra degree of freedom because of the bufferso that the primary power unit can be driven independent of the transient tractiondemand of the vehicle powertrain. Using a simple model of the power flows, energylevels and a regression model of the future driving, the resulting policy minimizesthe expected fuel consumption with respect to the prediction model of the futuredriving conditions.
Microcontroller based maximum power point tracker for solar panels
Solar energy is one of the most important renewable energy sources. Unfortunately, photovoltaic (PV) power systems have two major problems: the conversion efficiency and the amount of electric power generated by solar panels changes continuously with weather conditions.Maximum power point tracking (MPPT) techniques should be used in photovoltaic systems to maximize the PV panel output power by tracking continuously the maximum power point (MPP) which depends on panel?s temperature and on irradiance conditions. Especially for low-cost implementations, the perturb and observe (P&O) maximum power point tracking algorithm is the most commonly used method due to its ease of implementation.
An artificial neural network controlled microelectromechanical accelerometer
In this dissertation, a neural network based Micro-Electro-Mechanical-System (MEMS) accelerometer is designed. Analog neural network controller for the MEMS accelerometer is researched and a specific hardware design is implemented. Aim of the proposed neural network controller is to improve the performance of capacitive MEMS accelerometer. The study has been performed in both MATLAB and SPICE environments. Simulation results show that, proposed neural network controller improves performance of MEMS accelerometer.
Design and implementation of an automotive remote diagnostic electronic unit for road vehicles
The aim of this project is to design and improve a Centrically Acquisited Data and Fault Management System. The system will provide to collect and store the data and faults on the vehicle, to send these data to a remote centre, to response to vehicle from the remote centre when required and to integrate this system to road vehicles. An electronic card and a firmware which can communicate with the vehicle CAN (Controller Area Network) and read the faults of the vehicle, an electronic card which can get the location of the vehicle through GPS (Global Positioning System), an electronic card and a firmware which can send these data to a remote centre through GPRS is designed. These electronic cards are integrated and adapted to the vehicle. Keywords: Centrically Controlled Data, Fault Management System, CAN, GPS & GPRS, Remote Fault Code Sending
Design and implementation of a CAN communication line diagnosis systematic for road vehicles
The purpose of this study is to design and improve a Failure and Data Management System which provides to process the data which is read from vehicle CAN line and transmitted to the remote center. A server and a database which provides the availability of stored data will be designed. The data which is read from the vehicle and sent to remote center by the integrated remote diagnosis module will be analyzed and classified by the designed Failure and Data Management System. The real vehicle data which is collected about a specified region, a model or a component will be filtered according to the different combinations that the operator is able to set off. The field feedback reports which are based on the real vehicle data will be able to prepared through the Data Management Console.
A new approach for N-stage RC ladder networks based on Elmore delay model
Elmore delay model which is considered to be the most popular and unprecedented method of analog and digital integrated circuit delay calculations, is the main part of many design approaches ever since. Through delay calculations of VLSI circuits, distributed RC ladder networks are utilized as a modelling tool. Thus, delay calculation complexity of corresponding circuit is related with the stage number of RC ladder network. Thanks to Elmore delay model, complex calculations are easily done. In this thesis, a composed linear relation between SPICE simulation results, experimental test results and Elmore delay model is observed during researches for N-Stages RC ladder network. After characterizing the deviation problem between SPICE and Elmore delay, an improved Elmore delay model is proposed. The proposed delay model is extracted by applying Least Mean Square method on SPICE simulation results stated by experimental test results. The proposed method is tested on N-Stage RC ladders and test results are compared with that of SPICE simulation environment. All implementations of the proposed approach are done in MATLAB environment. Accordingly, the proposed method was shown to be significantly efficient.