Microfilm aperture card system

"Conducted under ARDC Research and Development project 2079."

Storage and retrieval of technical information; interim technical report.

"Prepared under contract NONR551(40), 1 September 1963."

Tabulating equipment: card processing operations; standard time values for determining operational effectiveness for planning estimates and for budget preparation.

Mode of access: Internet.

Voting systems standards.

Shipping list no.: 90-554-P.

Operator's manual : card punch-reader interpreter RO-526/MYQ-4 (NSN 7040-01-092-2551).

"February 1984."

Analysis and Optimization of Synthetic Aperture Ultrasound Imaging Using the Effective Aperture Approach

An effective aperture approach is used as a tool for analysis and parameter optimization of mostly known ultrasound imaging systems - phased array systems, compounding systems and synthetic aperture imaging systems. Both characteristics of an imaging system, the effective aperture function and the corresponding two-way radiation pattern, provide information about two of the most important parameters of images produced by an ultrasound system - lateral resolution and contrast. Therefore, in the design, optimization of the effective aperture function leads to optimal choice of such parameters of an imaging systems that influence on lateral resolution and contrast of images produced by this imaging system. It is shown that the effective aperture approach can be used for optimization of a sparse synthetic transmit aperture (STA) imaging system. A new two-stage algorithm is proposed for optimization of both the positions of the transmitted elements and the weights of the receive elements. The proposed system employs a 64-element array with only four active elements used during transmit. The numerical results show that Hamming apodization gives the best compromise between the contrast of images and the lateral resolution.

Recent advances in radar technology

The technical developments and advances that have taken place thus far are reviewed in those areas impacting future phased array active aperture radar systems. The areas covered are printed circuit antennas and antenna arrays, GaAs MMIC design and fabrication leading to affordable transmitter-receiver (T-R) modules, and novel hardware and software developments. The use of fiber-optic distribution networks to interconnect the monolithically integrated optical components with the T-R modules is discussed. Beamforming and sidelobe control techniques for active phased array systems are also examined.

The market of academic journals : empirical evidence from data on French libraries

This paper analyzes the demand and cost structure of the French market of academic journals, taking into account its intermediary role between researchers, who are both producers and consumers of knowledge. This two sidedness feature will echoes similar problems already observed in electronic markets – payment card systems, video game console etc - such as the chicken and egg problem, where readers won’t buy a journal if they do not expect its articles to be academically relevant and researchers, that live under the mantra “Publish or Perish”, will not submit to a journal with either limited public reach or weak reputation. After the merging of several databases, we estimate the aggregated nested logit demand system combined simultaneously with a cost function. We identify the structural parameters of this market and find that price elasticities of demand are quite large and margins relatively low, indicating that this industry experiences competitive constraints.

Construction of a limited geographic location code; a report of a project sponsored by the Manpower Branch, Human Resources Division, Office of Naval Research, Contract N 7 onr-422.

Mode of access: Internet.

Bibliography on the use of IBM machines in sciences, statistics, and education.

Mode of access: Internet.

Punched cards; their applications to science and industry.

Mode of access: Internet.

100 years of data processing : the punchcard century /

Mode of access: Internet.

Punched cards : their applications to science and industry /

Contains bibliographies.