National Security Agency

About: National Security Agency is a government organization based out in Fort George Meade, Maryland, United States. It is known for research contribution in the topics: Signal & Encryption. The organization has 393 authors who have published 485 publications receiving 15916 citations. The organization is also known as: NSA & N.S.A..

Single-use USB port protector

Abstract: A single-use Universal Serial Bus port protector having a top piece and a tongued planar surface, where the top piece includes a rectangular surface, a rectangular planar surface, a slotted planar surface, and at least one lever breakably attached to the slotted planar surface, and where the tongued planar surface includes two rails and two projections, where the top piece and the tongued planar surface are slideably insertable into a Universal Serial Bus port to ensure that no electrical connection is made to the Universal Serial Bus port when the top piece and the tongued planar surface are so inserted, where the at least one lever engages with at least one of the rails of the tongued planar surface upon insertion, and where the at least one lever breaks off when the Universal Serial Bus port protector is removed from the Universal Serial Bus port.

Optical fiber coupler type wavelength measuring apparatus

Abstract: A fiber optic wavelength measuring apparatus using the wavelength dependent nature of a fused fiber coupler to measure the wavelength of light propagating in an optical fiber. The input light is coupled, using a fused fiber coupler, of the type commonly used as wavelength division mutiplexers, into two fibers and the light in these two fibers is then measured using a pair of fiber coupled photodiodes. The ratio of the optical power of light in the two fibers corresponds to the wavelength of the input light. Hence it is possible to perform precise real-time measurement of the wavelength of light in a fiber with a compact, inexpensive, and field rugged apparatus.

Method of identifying boundary of markerless codeword

Abstract: The present invention is a method of determining codeword boundary without marker bits by receiving transmission bits; determining a dual code of a code used to generate the transmission bits; selecting a vector from the dual code; initializing n scoring variables; initializing i=1; initializing z=1; selecting n bits from the transmission bits starting at bit position i; performing a bit-wise AND operation on the vector and the n selected bits; if the result of the bit-wise AND operation contains an even number of ones then assigning a value of zero to the result, otherwise assigning a value of one to the result; setting S z equal to S z plus the result of the last step; if z is less than n, incrementing z and i each by 1 and returning to the seventh step, otherwise proceeding to the next step; if z=n, i

Comparison Of Modeling And Experimental Results In Contrast Enhancement Lithography

Abstract: Characterizing the effects of the many variables that are a part of photolithography is not an easy task. As more sophisticated patterning techniques, such as contrast enhancement lithography (CEL), are introduced the number of variables increases. Two tools are commonly used to deal with the complex task of understanding the interrelationships of these many variables: experimentation and computer simulation. While experimentation, and in particular statistically designed experiments, can give a great deal of insight into a particular system, it is often difficult to extrapolate trends outside of the experimental conditions (e.g., to other lithographic systems). Computer modeling, on the other hand, is rather poor at predicting exact outcomes of specific conditions, but is at its best when predicting trends which may exist over a broad or narrow range of conditions. There exists, however, an uncertainty as to how accurately the model reflects conditions of the real world.© (1988) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Method of measuring degree of enhancement to voice signal

Abstract: A method of measuring the degree of enhancement made to a voice signal by receiving the voice signal, identifying formant regions in the voice signal, computing stationarity for each identified formant region, enhancing the voice signal, identifying formant regions in the enhanced voice signal that correspond to those identified in the received voice signal, computing stationarity for each formant region identified in the enhanced voice signal, comparing corresponding stationarity results for the received and enhanced voice signals, and calculating at least one user-definable statistic of the comparison results as the degree of enhancement made to the received voice signal.