Digital systems

Pulse Inputs Where the sensor within the measurement device is digital in nature, analog-to-digital conversion can be avoided. For rotational devices, the rotational element can be outfitted with a shaft encoder that generates a known number of pulses per revolution. The digital system can process such inputs in either of the following ways ... 

Digital control methodologies similar to the Elliott Digital System program evolved from successful and proven reliable high-speed air compressor management and control approaches. 

Before diseussing the turbomaehinery management attributes of digital systems, it is helpful to review the hardware, software, and MACS PACK eomponents. 

This is the base paekage in eaeh Elliott Digital System. Hardware and software of the EDS deseribed above are integrated into a program that provides the following ... 

Providing single wire connections between tlie unit-mounted junction boxes and tlie digital system, which reduces field wiring costs. 

The ion detection system consists of a high-gain electron multiplier and the signal digitizing system, along with a computer for data acquisition and manipulation. 

This sequence of events is quite rapid. If we take typical instrumental conditions of the LIMA 2A, where the UV laser pulse duration is 5-10 ns, the fight path is "2 m, and the accelerating potential is 3 kV, then an ion arrives at the detector i n approximately 3 ps, and a ion arrives at the detector in approximately 40 ps. Since the time width of an individual signal can be as short as several tens of nanoseconds, a high speed detection and digitizing system must be employed. 

A 10-bit digital system uses the sequence 180, 90, 45, 22.5, etc., to transmit the azimuth value. What is the accuracy of the transmission Give the binary numbers for S-23-E by excess, default and nearest. 

Amador, E. Pippert, J. A. Emary, R. J. Serum creatinine and glucose analyses by an automated rapid sampling digital system. Clin. Chem. (1971), 17, 655. 

Figure 2.2.9 shows a typical portable MRI console. The MRI console consists of a digital system (PC), MRI transceiver, 3 channel gradient driver and rf transmitter. 

All of the digital modules are installed inside the industrial PC as shown in Figure 2. 2.10. The major functions of the MRI digital system are implemented by three commercially available ISA boards. 

Fig. 2.2.10 Block diagram of the digital system of the compact MRI constructed within a PC.

Simple digital systems are assembled from well-known libraries of parts combinational logic gates (and, or, inverters, tri-state buffers) storage elements (flip-flops, registers, RAM) synchronization parts (clocks, dividers). From these parts are assembled a huge variety of systems, but all of them can be understood in terms of these basic parts. 

Direct digital control systems appeared in the mid-1980s and displaced older analog closed-loop schemes for temperature control. These digital systems improved both accuracy and reliability. The earlier systems were modeled after existing system architectures and did not contain intelligent, standalone field devices. There were numerous interfaces to the various building systems and the major decisions were made at a central computer. 

In one application (Maitre, 1981), the parallelism of noncoherent optical convolution methods is combined with video techniques in a totally analog application to images. Matsuoka et al (1982) have developed a hybrid optical-video-digital system based on similar principles. Pipeline processors that perform image convolution at high speed are ideal for digital applications. The inherent simplicity of the method adapts it to high-speed implementations by use of other hybrid techniques. It is even possible to devise a transversal filter that has all the desirable nonlinear properties of the method. We describe this filter in the next section. 

Linear-phase digital filters can remove the problem of filter interactions, but speech intelligibility results for multi-channel digital systems are no more encouraging than those for their analog counterparts [Kollmeier et al., 1993],... 

Vanderkooy and Lipshitz, 1984] Vanderkooy, J. and Lipshitz, S. (1984). Resolution below the Least Significant Bit in Digital Systems with Dither. J. Audio Eng. Society, 32 106-113. Correction, ibid., vol. 32, pp. 889, June 1987. 

Waser and Flynn, 1982] Waser, S. and Flynn, M. J. (1982). Introduction to Arithmetic for Digital Systems Designers. Holt, Rinehart, Winston. 

There is also the three-digit system for directions in hexagonal crystals. For planar indices, it uses intercepts on the ai, a2, and c axes. The indices (HKL) are related to the Miller-Bravais indices (hkil) by... 

The four- and three-digit systems are compared in Figure 3.4 for four directions. 

Translate (210) in the three-digit system into the four-digit Miller-Bravais system. What are the equivalent 210 planes Express these in both the three-digit and four-digit systems. 

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