A preliminary investigation into the performance of a simple Time Encoded Speech (TES) isolated word recognition (IWR) direct voice input (DVI) system, using both normal and whi1pered (unvoiced) speech is described. Experimental conditions include evaluations with untrained military speakers in severe acoustic background noise ( c. 70-90 dB SPL) with handheld omnidirectional microphones. System...

background and aims. radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. digital subtraction radiography has recently been used to improve the diagnostic quality of these lesions. the purpose of this study was to compare the ca...

introdouction:the study aimed to compare the accuracy of proximal caries detection by dental practitioners using two different systems, direct digital system and conventional films, under routine environmental conditions. materials and methods: eleven extracted human posterior teeth were mounted on wax frames and were exposed using the direct digital system and conventional films. seventy-four ...

This paper introduces a new approach to direct digital frequency synthesis (DDFS) based on the Coordinate Rotation (CORDIC) algorithm. The modifications to the standard CORDIC algorithm introduced in this paper allow fine frequency resolution, and exhibit significant potential for low power applications. The new architecture does not need a large ROM and can be implemented on a general purpose ...

This paper describes a design of signal generator based on direct digital synthesis technique (DDS). According to the basic principles of DDS using Matlab/DSP Builder establish DDS model, then compiling by the SignalCompiler tools and generating VHDL code. Finally download the relevant documents to the field programmable gate array (FPGA) chip EP2C5Q208C8N. EP2C5Q208C8N and digital-analog chip ...

Linearity is an important measure of an analog amplifier performance and normally measured by the 3rd order inter-modulation product (IP3) under a two-tone test. In this paper, we propose a test scheme that generates test tones using a built-in direct-digital synthesizer (DDS). Radio Frequency (RF) test tones are generated by converting the DDS output to RF using a built-in analog mixer that ca...

Chirped pulse Fourier transform microwave (CP-FTMW) spectrometers have become the instrument of choice for acquiring rotational spectra, due to their high sensitivity, fast acquisition rate, and large bandwidth. Here we present the design and capabilities of a recently constructed CP-FTMW spectrometer using direct digital synthesis (DDS) as a new method for chirped pulse generation, through bot...

Recent research on frequency synthesis concentrates mainly on specific wireless applications requiring high-purity gigahertz carriers in a narrow frequency band, with moderate resolution an tuning speed. A low power consumption is often a must for mobility, thus a PLL solution is indicated. The main benefits of direct digital synthesis (DDS), very wide band operation with millihertz resolution,...

background the first commercial system for digital radiography was introduced in 1987, and it has evolved a great deal since then. currently, it is possible to enhance images in digital radiography. objectives the aim of this study is to evaluate the diagnostic accuracy of image enhancement in direct digital radiography as it relates to interproximal carries assessment. conclusions using these ...