The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper demonstrates how flexural wave propagation in a thin plate can be modeled by estimating the combined effect of the excitation source signal and the impulse response of the ultrasonic sensor. The wave propagation in the plate is modeled using the wave equation for the flexural wave mode. A theoretical model for flexural wave propagation in thin plates has been derived, and it has been compared...
Reverberation and multipath propagation afîect the accuracy of time of flight (TOF) estimation in confined underwater medium. In this paper, time delay has been estimated by obtaining the transmitted signal and first echo signal from measured signal acquised by using a wideband transducer with 5 MHz central frequency. Cross-correlation (CC) and generalized cross-correlation (GCC) methods have been...
In this study, the wind speed prediction model is created that gives a minimum error for different hidden layer neuron numbers and delay step numbers. Using the one-minute time series, the prediction of the next wind speed is performed with the NAR neural network model. The predicted values of wind speed obtained are compared with predicted values of wind speed obtained with filter methods. For different...
This study focuses on the modelling of 3 axis gimbal system with the RRR joint structure on the Unmanned Aerial Vehicle (UAV), which is autonomously moving for the target tracking, based on experimental input (motor velocities) and output (end effector position) data. The fact that UAVs move in a certain direction and that the camera on the end effector of the gimbal system on it is adhere to the...
In this stuidy, the position information from ultrasound sensors on UAV related to floor gallery mine passed through the filter, it is aimed to control the position of simultaneously creating the optimum environmental map. The simultaneous in galleries made mapping, mine the data of air to the designated central monitoring system with real-time location information is transmitted to the ventilation...
The spatially limited plane (SLP) wave can be created by exciting the ring transducer elements with different amplitudes and at different times. Although the ring transducer initially worked well, many transducer elements have become inoperative, due probably to service life and material life. The result of these bad elements is artifacts in the resulting spatially limited plane waves. In this study,...
In this paper, two different methods are suggested in order to provide image enhancement in ultrasonic B-mode imaging. By obtaining RF data from two different phantom used to form B-mode image, their spectral characteristics were observed. Then by forming RF envelope from obtained data, conversion of envelope to color image is provided. Logarithmic compression and histogram equalization methods found...
In this study, we perform target detection and tracking with Unmanned Aerial Vehicle (UAV) as well as the visual command of UAV. Our goal is to develop an autopilot system to reduce the human factor in UAV's. We create a system that follows different objects, stays locked to a graphical object which is glyph that has an encryption that only we describe, and executes the mission encoded on glyph in...
In this study, unmanned vehicles used for target tracking camera RRP (revolute revolute prismatic) joint structure with a three-jointed robot arm with the position, velocity and acceleration control is made. In order to be able to follow the specified trajectory, the system used in the control of the robot arm with joint structure RRP target tracking model based on changing according to the structure...
Time delay estimation has been used as a research area of significant practical important in many fields such as especially military system like localization, targeting, course acquisition also sonar, seismology, hands-free communications etc. In these applications, it is important to detect the delay and arrival times of ultrasonic echoes comprised in the medium for ultrasonic signals. Here, it is...
In this study, it is aimed to follow a visual route by an Unmanned Aerial Vehicle (UAV). The recognition of the predetermined line by using image processing algorithms and the process of following the route by using the method of Tangent Vector Field Guidance (TVFG) have been performed in indoor and outdoor experiments. UAV s following the correct route has been ensured by calculating the deflection...
The speech signals are formed with echo caused by the reflections and also noise caused by engine, tyres, wind, etc during using hands-free voice communication in automobiles. In this paper, it has been focused on the adaptive filtering algorithms that based on eliminating purpose of not only noise removal but also separation in speech signals with echo and noise. It has been evaluated that the speech...
The amplifiers that are used on communication systems in order to increase the productivity, are worked on the nonlinear region. Therefore, digital communication channel can be defined as a Wiener block structure that contains a linear dynamic system and a non-linear static block. In this study, the nonlinear channel equalization problem, a Wiener block structured communication channel is tried to...
Acoustic echo in voice transmission systems severely degrades the speech quality and the speech intelligibility of speech signal due to it is formed through picking up sounds from the loudspeaker by speaker microphone. The dynamic structure of the acoustic echo system contains cascade connection of an electro-acoustic static nonlinear system and a dynamic linear system. Hence linear models can not...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.