57,793 research outputs found
LOGSIM programmer's manual
A programmer's manual is reported for a Logic Simulator (LOGSIM) computer program that is a large capacity event simulator with the capability to accurately simulate the effects of certain unknown states, rise and fall times, and floating nodes in large scale metal oxide semiconductor logic circuits. A detailed description of the software with flow charts is included within the report
Rural Broadband Internet Access Supply and Demand
Internet use has grown rapidly over the last 15 years and so has its integration into the rural economy. Connecting to the Internet via high-speed technology such as DSL lines, cable, satellite, and wireless networks increases bandwidth and makes the Internet much more useful to businesses, households, and governments. Rural households are almost as likely as urban households to use the Internet. Broadband Internet access in rural areas has been less prevalent than in much more densely populated areas of the country. Evidence suggests that the difference may lie in the higher cost or less availability of broadband Internet access in rural areas. The paucity of national geographically-specific data, however, presents a challenge in trying to analyze questions of broadband take-up. Data from the June Agricultural Surveys, however, address this. The other difficulty has been obtaining local price in demand analysis. We use ARMS and industry data to develop local broadband service price indices. We use descriptive statistics and binomial logit models in our analysis. The data shows sharp differences in conversion rates across the country, and when also considering the changes over time giving some credence to the common hypothesis that people do choose to use broadband if given the option. Farms were unlikely to make the direct jump from no Internet use to Internet use with broadband access; farms that already had Internet access were more likely to convert to broadband Internet access. Some of the farms that did not convert already had broadband Internet access by 2005, roughly 24 percent of all farms using the Internet in 2005. The preponderance of DSL service for farms indicates both the mostly rural location of most farms as well as Internet users finding satellite a less desirable option. While broadband Internet access availability is necessary for take-up of broadband Internet access, there are other factors that are also limiting broadband Internet use such as price of access, age of user, household income, and educational attainment.broadband Internet access, rural communities, farm communities, Community/Rural/Urban Development, Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods, O33, R0,
Theoretical investigation of the force and dynamically coupled torsional-axial-lateral dynamic response of eared rotors
Difficulties in solution methodology to be used to deal with the potentially higher nonlinear rotor equations when dynamic coupling is included. A solution methodology is selected to solve the nonlinear differential equations. The selected method was verified to give good results even at large nonlinearity levels. The transfer matrix methodology is extended to the solution of nonlinear problems
Design concepts for low-cost composite turbofan engine frame
Design concepts for low cost, lightweight composite engine frames were applied to the design requirements for the frame of a commercial, high bypass engine. Four alternative composite frame design concepts identified which consisted of generic type components and subcomponents that could be adapted to use in different locations in the engine and the different engine sizes. A variety of materials and manufacturing methods were projected with a goal for the lowest number of parts at the lowest possible cost. After a preliminary evaluation of all four frame concepts, two designs were selected for an extended design and evaluation which narrowed the final selection down to one frame that was significantly lower in cost and slighty lighter than the other frame. An implementation plan for this lowest cost frame is projected for future development and includes prospects for reducing its weight with proposed unproven, innovative fabrication techniques
LOGSIM user's manual
The user's manual for the LOGSIM Program is presented. All program options are explained and a detailed definition of the format of each input card is given. LOGSIM Program operations, and the preparation of LOGSIM input data are discused along with data card formats, postprocessor data cards, and output interpretation
Compensator improvement for multivariable control systems
A theory and the associated numerical technique are developed for an iterative design improvement of the compensation for linear, time-invariant control systems with multiple inputs and multiple outputs. A strict constraint algorithm is used in obtaining a solution of the specified constraints of the control design. The result of the research effort is the multiple input, multiple output Compensator Improvement Program (CIP). The objective of the Compensator Improvement Program is to modify in an iterative manner the free parameters of the dynamic compensation matrix so that the system satisfies frequency domain specifications. In this exposition, the underlying principles of the multivariable CIP algorithm are presented and the practical utility of the program is illustrated with space vehicle related examples
Simultaneous chromatic dispersion, polarization-mode-dispersion and OSNR monitoring at 40Gbit/s
A novel method for independent and simultaneous monitoring of chromatic dispersion ( CD), first-order PMD and OSNR in 40Gbit/s systems is proposed and demonstrated. This is performed using in-band tone monitoring of 5GHz, optically down-converted to a low intermediate-frequency (IF) of 10kHz. The measurement provides a large monitoring range with good accuracies for CD (4742 +/- 100ps/nm), differential group delay (DGD) (200 +/- 4ps) and OSNR (23 +/- 1dB), independently of the bit-rate. In addition, the use of electro-absorption modulators (EAM) for the simultaneous down-conversion of all channels and the use of low-speed detectors makes it cost effective for multi-channel operation. (C) 2008 Optical Society of Americ
A study of the effects of varying the sampling for a simplified version of the Saturn V/S-1C Final report, 15 May 1968 - 31 Aug. 1969
Bending frequency filtering through adaptive sampling for Saturn 5 stage 1C desig
Laboratory calibration of AAFE radiometer/scatterometer (RADSCAT)
A brief description of the electrical and mechanical instrument configuration, followed by an extensive discussion of laboratory tests and results are contained herein. This information is required to provide parameters for data reduction, and a basis for analysis of the measurement errors in data taken with this instrument
An innovative approach to compensator design
The design is considered of a computer-aided-compensator for a control system from a frequency domain point of view. The design technique developed is based on describing the open loop frequency response by n discrete frequency points which result in n functions of the compensator coefficients. Several of these functions are chosen so that the system specifications are properly portrayed; then mathematical programming is used to improve all of these functions which have values below minimum standards. To do this, several definitions in regard to measuring the performance of a system in the frequency domain are given, e.g., relative stability, relative attenuation, proper phasing, etc. Next, theorems which govern the number of compensator coefficients necessary to make improvements in a certain number of functions are proved. After this a mathematical programming tool for aiding in the solution of the problem is developed. This tool is called the constraint improvement algorithm. Then for applying the constraint improvement algorithm generalized, gradients for the constraints are derived. Finally, the necessary theory is incorporated in a Computer program called CIP (compensator Improvement Program). The practical usefulness of CIP is demonstrated by two large system examples
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