Digital signal

About: Digital signal is a research topic. Over the lifetime, 44213 publications have been published within this topic receiving 345279 citations.

Surface defect inspecting apparatus

Abstract: The holding mechanism (112) holds an object under inspection in a manner that the substantially entire surface of the object (108) may relatively be scanned by a laser beam. A spherical integrating light collector (127) has an opening (127a) disposed close to the inspected surface of the object (108) held by the holding mechanism (112). A laser beam illuminating mechanism (128) is coupled with the other end of the spherical integrating light collector (127), and illuminates the inspected surface of the object (108) with the laser beam through the opening (127a). A photo-electric converter (129) receives the scattered light as is reflected by the inspected surface and collected by the spherical integrating light collector (127), and converts the scattered light into an electrical signal representing an amount of light. An analog to digital converter (132) converts the electrical signal derived from the photo-electric converter (129) into a digital signal. A peak detector (133) receives the digital signal derived from the analog to digital converter (132) to detect peak values at predetermined periods. A mean value calculator (134) calculates a mean value using a digital signal output from the analog to digital converter (132). A reference value storing memory (141) stores a reference value to determine defects present on the inspected surface of the object (108). A threshold level calculator (140) calculates the threshold level using the reference value and the mean value. A defect detector (137) compares peak values derived from the peak detector (133) with the threshold level, and detects the surface defects on the basis of the result of the comparison.

Semi transparent tributary for synchronous transmission

Abstract: An interface for converting a variety of incoming digital signals into SDH/SONET format for transmission on a synchronous digital network, by identifying the line code of the incoming digital signal, without identifying the information for OSI layer 2 or 3 processing, i.e. format of each packet. Headers are used to encapsulate incoming packets, and enable packets to be discriminated at the receiver. Advantages of performance monitoring capability and transparency are combined. Identifying line codes enables a greater degree of error detection, than a bit based interface. Also synchronisation can be simpler since line codes for padding can be added or deleted more easily than adding or subtracting bits. The interface is semi-transparent in the sense that identification of line codes limits the interface to those formats that use identifiable line codes, but without limiting to a particular OSI layer 2 or 3 frame format.

Method of operating write assist circuitry

Abstract: A method includes causing, by a first circuit, a first signal transition at a first node based on a clock signal. A first edge, from a first level to a second level, of a word line signal is generated responsive to the first signal transition. A second signal transition at a second node is caused by a second circuit based on the clock signal. The second circuit and the first circuit are configured to cause the second signal transition to occur later than the first signal transition by a delay time. A first edge, from a third logic level to a fourth level, of a tracking word line signal is generated responsive to the second signal transition.

Voice command recognition system based on mfcc and dtw

Abstract: Kurukshetra University, Department of Instrumentation & Control Engineering., H.E.C* Jagadhri, Haryana, 135003, India sachdevaanjali26@gmail.com ABHIJEET KUMAR Mullana University, Department of Electronics and Comm. Engineering., M.M.E.C Mullana, Haryana, 133203, India abhijeetsliet@gmail.com NIDHIKA BIRLA Kurukshetra University, Department of Electronics Engineering., H.E.C Jagadhri, Haryana, 135003, India nidhikabirla@gmail.com Abstract: The Voice is a signal of infinite information. Digital processing of speech signal is very important for high-speed and precise automatic voice recognition technology. Nowadays it is being used for health care, telephony military and people with disabilities therefore the digital signal processes such as Feature Extraction and Feature Matching are the latest issues for study of voice signal. In order to extract valuable information from the speech signal, make decisions on the process, and obtain results, the data needs to be manipulated and analyzed. Basic method used for extracting the features of the voice signal is to find the Mel frequency cepstral coefficients. Mel-frequency cepstral coefficients (MFCCs) are the coefficients that collectively represent the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale of frequency.This paper is divided into two modules. Under the first module feature of the speech signal are extracted in the form of MFCC coefficients and in another module the non linear sequence alignment known as Dynamic Time Warping (DTW) introduced by Sakoe Chiba has been used as features matching techniques. Since it’s obvious that the voice signal tends to have different temporal rate, the alignment is important to produce the better performance. This paper presents the feasibility of MFCC to extract features and DTW to compare the test patterns.

Portable circuit and method for performing a time study and analysis of bodily ionic characteristics

Abstract: A portable circuit and method for performing a time study and analysis of bodily ionic characteristics as esophageal pH includes a transducer 11 for measuring pH and generating a proportional analog signal and an interface 12 for converting this signal into a representative digital signal including offset and gain controls 23,24 for permitting correction for transducer 11 calibration drift during the study period. A processor 14 receives and stores all digital signals for rapid transmission to a data analysis after the study period is ended. Esophageal pH values are measured and stored for a plurality of pre-study and post-study known conditions.