Wyniki wyszukiwania - Biblioteka Nauki

1

Phase Autocorrelation Bark Wavelet Transform (PACWT) Features for Robust Speech Recognition

100%

Majeed S. A. , Husain H. , Samad S. A.

Archives of Acoustics

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2015

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tom Vol. 40, No. 1

25--31

EN

In this paper, a new feature-extraction method is proposed to achieve robustness of speech recognition systems. This method combines the benefits of phase autocorrelation (PAC) with bark wavelet transform. PAC uses the angle to measure correlation instead of the traditional autocorrelation measure, whereas the bark wavelet transform is a special type of wavelet transform that is particularly designed for speech signals. The extracted features from this combined method are called phase autocorrelation bark wavelet transform (PACWT) features. The speech recognition performance of the PACWT features is evaluated and compared to the conventional feature extraction method mel frequency cepstrum coefficients (MFCC) using TI-Digits database under different types of noise and noise levels. This database has been divided into male and female data. The result shows that the word recognition rate using the PACWT features for noisy male data (white noise at 0 dB SNR) is 60%, whereas it is 41.35% for the MFCC features under identical conditions.

2

Flow characteristics in a vascular tube with an overIapping constriction

100%

Pramanik S. , Mukhopadhyay S. , Layek G. C. , Samad S. A.

International Journal of Applied Mechanics and Engineering

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2007

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tom Vol. 12, no 1

153-167

EN

A numerical solution to the unsteady blood flow in the neighbourhood of an overlapping constriction is obtained under laminar flow conditions. Blood is modelled as a viscous, incompressible and of Newtonian type fluid. A finite-difference staggered grid has been used to solve the unsteady incompressible Navier-Stokes equations in cylindrical polar co-ordinates under the axi-symmetric conditions. A co-ordinate transformation has been employed to map the constricted tube into a straight tube. The effect of flow characteristics in this type of constriction and its consequences in arterial diseases are investigated. Flow features such as velocity, pressure and wall shear stress distributions are presented graphically. The secondary separation has been noted in the downstream of the overlapping constriction when the Reynolds number of the flow is about 205.

3

Comparative Survey on Traffic Sign Detection and Recognition: a Review

100%

Wali S. B. , Hannan M. A. , Hussain A. , Samad S. A.

Przegląd Elektrotechniczny

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2015

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tom R. 91, nr 12

38-42

EN

Developing real-time Advanced Driver Assistance Systems (ADAS) based on video aiming to extract reliable vehicle state information has attracted a lot of attention during the past decades. This ADAS system includes inter-vehicle communication, driver behavioral monitoring, and human-machine interactions. In these systems, robust and reliable traffic sign detection and recognition (TSDR) technique is a critical step for ensuring vehicle safety. This paper provides a comprehensive survey on traffic sign detection and recognition system based on image and video data. Our main focus is to present the current trends and challenges in the field of developing an efficient TSDR system followed by a detail comparative study between different renowned methods used by various researchers. Finally, conclusion followed by some future suggestion is provided to develop an efficient TSDR system is provided. This survey will hopefully lead to develop an effective traffic sign detection and recognition system which will ensure driver safety in future.

PL

System ADAS (Advanced Driver Assistance System) obejmuje także metody rozpoznawania znaków drogowych. W artykule przedstawiono przegląd metod detekcji i rozpoznawania znaków drogowych bazujących na obrazie video. W artykule dokonano oceny istniejących metod oraz zaproponowano środki poprawy ich efektywności.

4

Shape Matching and Color Segmentation Based Traffic Sign Detection System

88%

Wali S. B. , Hannah M. A. , Abdullah S. , Hussain A. , Samad S. A.

Przegląd Elektrotechniczny

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2015

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tom R. 91, nr 1

36-40

EN

An automatic traffic sign detection system detects traffic signs from within images captured by an imaging sensor, and assists the driver to properly operate the vehicle. The idea presented here is through pixel value detection for hazard traffic signs containing red color background, computing in range regions and finally shape matching to choose the most appropriate traffic sign candidates to be drawn on the screen. The experimental result showed that, by comparing with the similar color segmentation based techniques, the proposed system has a higher accuracy of traffic sign detection rate with a lower computational time.

PL

W artykule opisano system automatycznego rozpoznawania znaków drogowych na podstawie sygnału czujnika obrazu. System rozpoznaje znaki na czerwonym tle, dopasowuje odpowiedni znak i wyświetla go na ekranie.

5

Traffic Sign Classification based on Neural Network for Advance Driver Assistance System

88%

Hannan M. A. , Wali S. B. , Pin T. J. , Hussain A. , Samad S. A.

Przegląd Elektrotechniczny

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2014

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tom R. 90, nr 11

169--172

EN

Traffic sign is utmost important information or rule in transportation. In order to ensure the transportation safety the automotive industry has developed Advance Driver Assistance System (ADAS). Among the ADAS system, development of TSDR is the most challenging to the researchers and developers due to unsatisfying performance. This paper deals with, automatic traffic sign classification and reduces the effect of illumination and variable lighting over the classification scheme by using neural network according to the traffic sign shape. There are three main phase of the classification scheme such as; pre-processing using image normalization, feature extraction using color information of 16-point pixel values and multilayer feed forward neural network for classification. An accuracy rate of 84.4% has been achieved by the proposed system. Overall processing time of 0.134s shows the system is a fast system and real-time application.

PL

W artykule opisano metodę automatycznego rozpoznawania I klasyfikacji znaków drogowych z przenaczeniem do inteligentnych systemów wspomagania kierowcy ADAS. Do tego celu wykorzystano sieci neuronowe przeprowadzając normalizację obrazu, ekstrakcję cech i klasyfikację. Osiągnieto dokładność rozpoznawania rzędu 84% przy przeciętnym czasie rozpoznawania około 0.13 s.

6

Power Amplifier Frequency Controller Using feedback control techniques for Bio-implanted Devices

88%

Hussein H. A. , Hannan M. A. , Mutashar S. , Samad S. A. , Mikdad A.

Przegląd Elektrotechniczny

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2015

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tom R. 91, nr 12

34-37

EN

Switch mode power amplifier is used in biomedical devices widely. The power amplifier supplies the required operating power to the implanted devices. Zero voltage switching (ZVS) operation of class-E power amplifier leads to convert DC voltage to AC with high efficiency and workings frequency. Frequency has a great function in powering most of the biomedical implanted devices. Frequency shift caused by inductors and capacitors used in the circuit can cause load variation or changing in mutual displacement or they may lead to instability and data loss of the implanted devices. So switching-mode frequency control is the key problem in the biomedical device powering system. This paper focused on the design of a frequency controlled power amplifier to improve the controller’s efficiency in terms of speed and better results. The objective of this work is to control the operating frequency. Feedback control method is used by using proportional integral derivative controller (PID), proportional integral (PI) and voltage controlled oscillator (VCO) to reduce the phase shift and settling time. The Bode plot and Nyquist stability criterion analyses show that the developed power amplifier frequency controller is stable and perform well to improve the controller efficiency.

PL

W artykule opisano wzmacniacz mocy używany w technice bio-implantów. Wzmacniacz klasy E z operacją ZVS przekształca stałe napięcie na napięcia AC. Kontrola częstotliwości tego napięcia ma ważne znaczenie ponieważ częstotliwość może się zmieniać przy obecności elementów L, C w układzie. W pracy opisano metode kontroli częstotliwości tego napięcia.