New LSI Digital Service Units and Office Channel Units Used for NTT Digital Data Networks

We live in a digital era in which communication is largely based on the exchange of digital information on data networks. Communication is often pictured as a sender that transmits a digital file to a receiver. This file travels from a source to a destination and, to have a quick and immediate communication, we need an encoding strategy that should be efficient and easy yet secure. This communication could be based on a layout articulated in two operations that are heterogeneous and in some case conflicting but that are needed to be applied to the original file to have efficiency and security. These two operations are data compression and encryption. The aim of this work is to study the combination of compression and encryption techniques in digital documents. In this paper we will test the combinations of some of the state-of-the-art compression and cryptography techniques in various kinds of digital data.

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Network testing system for digital data networks

Computer Networks and ISDN Systems ◽

10.1016/0169-7552(86)90055-3 ◽

1986 ◽

Vol 12 (3) ◽

pp. 175-182 ◽

Cited By ~ 1

Author(s):

Takashi Togawa ◽

Mineo Nishiwaki ◽

Ken-Ichiro Yoshida

Keyword(s):

Digital Data ◽

Data Networks ◽

Testing System ◽

Network Testing

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Creating a standard method of controlling digital microscopes: the microscope access protocol (map)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136453 ◽

1995 ◽

Vol 53 ◽

pp. 16-17

Author(s):

T. A. Dodson ◽

E. Völkl ◽

L. F. Allard ◽

T. A. Nolan

Keyword(s):

Data Storage ◽

Storage Systems ◽

Digital Systems ◽

Data Networks ◽

Digital Microscopy ◽

Command Language ◽

Access Protocol ◽

Analog To Digital ◽

Basic Physics ◽

Scanning Electron

The process of moving to a fully digital microscopy laboratory requires changes in instrumentation, computing hardware, computing software, data storage systems, and data networks, as well as in the operating procedures of each facility. Moving from analog to digital systems in the microscopy laboratory is similar to the instrumentation projects being undertaken in many scientific labs. A central problem of any of these projects is to create the best combination of hardware and software to effectively control the parameters of data collection and then to actually acquire data from the instrument. This problem is particularly acute for the microscopist who wishes to "digitize" the operation of a transmission or scanning electron microscope. Although the basic physics of each type of instrument and the type of data (images & spectra) generated by each are very similar, each manufacturer approaches automation differently. The communications interfaces vary as well as the command language used to control the instrument.

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Practical applications of scanning tunneling microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152069 ◽

1989 ◽

Vol 47 ◽

pp. 18-19

Author(s):

D. R. Denley

Keyword(s):

High Resolution ◽

Scanning Tunneling Microscopy ◽

Quantitative Information ◽

Digital Data ◽

Scanning Tunneling ◽

Ambient Atmosphere ◽

Tunneling Microscopy ◽

Clear Trend ◽

Practical Applications ◽

Promising Tool

Scanning tunneling microscopy (STM) has recently been introduced as a promising tool for analyzing surface atomic structure. We have used STM for its extremely high resolution (especially the direction normal to surfaces) and its ability for imaging in ambient atmosphere. We have examined surfaces of metals, semiconductors, and molecules deposited on these materials to achieve atomic resolution in favorable cases.When the high resolution capability is coupled with digital data acquisition, it is simple to get quantitative information on surface texture. This is illustrated for the measurement of surface roughness of evaporated gold films as a function of deposition temperature and annealing time in Figure 1. These results show a clear trend for which the roughness, as well as the experimental deviance of the roughness is found to be minimal for evaporation at 300°C. It is also possible to contrast different measures of roughness.

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Convergent-beam thickness determination: The advantages of digital imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169833 ◽

1994 ◽

Vol 52 ◽

pp. 420-421

Author(s):

Stuart McKernan ◽

C. Barry Carter

Keyword(s):

Intensity Variation ◽

Convergent Beam Electron Diffraction ◽

Digital Data ◽

Thickness Determination ◽

Frequent Use ◽

Automated Processing ◽

Beam Thickness ◽

Convergent Beam ◽

Remarkable Agreement

Convergent-beam electron diffraction (CBED) patterns contain an immense amount of information relating to the structure of the material from which they are obtained. The analysis of these patterns has progressed to the point that under appropriate, well specified conditions, the intensity variation within the CBED discs may be understood in a quantitative sense. Rossouw et al for example, have produced numerical simulations of zone-axis CBED patterns which show remarkable agreement with experimental patterns. Spence and co-workers have obtained the structure factor parameters for lowindex reflections using the intensity variation in 2-beam CBED patterns. Both of these examples involve the use of digital data. Perhaps the most frequent use for quantitative CBED analysis is the thickness determination described by Kelly et al. This analysis has been implemented in a variety of different ways; from real-time, in-situ analysis using the microscope controls, to measurements of photographic prints with a ruler, to automated processing of digitally acquired images. The potential advantages of this latter process will be presented.

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