Use Of Analog Techniques Research Articles

Варианты использования 3d сканирования в ортопедической стоматологии

The use of dental implants provides aesthetic dental prosthesis and high functionality, and innovative concepts and ideas associated with pre-prosthetic reconstruction of the jaw, allow the patients to improve the quality of life through the use of dentures on implants. However, the dentists and the implantologists forget about the category of patients who have the expressed dental phobic reactions accompanied with the neuromuscular disorders as the reflexes, in particular a gag reflex. A special approach and comprehensive treatment with the use of additional measures to resolve adverse reactions is necessary for these patients. This allows to simplify the work of dentists and to improve the quality of life of patients. Analysis of the results of the use of analog techniques for obtaining print and intraoral scanning each patient in one visit was conducted in this study. After treatment the patients were interviewed and questioned about the perception of both methods. A secondary purpose of the study was to determine the time required for each procedure. In a small number of cases, the patients negatively perceived total time required for intraoral scanning. The use of analog techniques as print required less time than for intraoral scanning. On the basis of the study results, the authors concluded that the patients preferred the intraoral scanning. The authors note that to obtain prints by means of the traditional method wasn’t carried out in two patients with a particularly strong gag reflex, and to obtain prints using dental impression masses was difficult in 9 patients. The majority of patients perceived long intraoral scanning more positively than the traditional method of obtaining prints using dental impression masses.

Amplitude and time measurement ASIC with analog derandomization: first results

We describe a new amplitude specific integrated circuit (ASIC) for accurate and efficient processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the analog-to-digital converter (ADC). Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output. Prototype chips have been fabricated in 0.35 micron CMOS and tested. First results indicate proper functionality for pulses down to 30 ns peaking time and random input rates up to 1.6 MHz on a single channel. Amplitude accuracy of the peak detect and hold circuit is 0.3% (absolute). TAC accuracy is within 0.3% of full scale. Power consumption is less than 2 mW/channel at the maximum counting rate. Compared with conventional techniques such as track-and-hold and analog memory, this new ASIC will enable efficient pulse height measurement at 20 to 300 times higher rates.

Amplitude and time measurement ASIC with analog derandomization

A versatile 32-channel ASIC has been developed for accurate processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the ADC. Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output.Prototype chips have been fabricated in 0.35μm CMOS and tested. Amplitude accuracy of the peak detect and hold circuit is 0.2% (absolute) and 0.04% (nonlinearity) for signals within 0.3V of either supply rail. Time walk is below 5ns, droop rate is 250mV/s, and power consumption is less than 2mW/channel at pulse rates up to 500kHz per channel.

Analogue solutions of linear programs

The general linear program with all variables non-negative is modelled with a circuit of batteries, resistors, voltmeters, and ammeters. From this model, a general analogue solution of the linear program follows. A specific example is taken from game theory. It is suggested that use of analogue techniques may be useful in examining changes in program solutions as the constraints of the problem are varied.

Analogue investigations of electric field distribution and ion trajectories in the field ion microscope

Analytical investigations of the electric field and stress acting on a field ion microscope specimen are based on the assumption that the specimen is smooth, ie the effects of shape variations at the atomic level are not considered. In this paper the possibilities of investigating the corresponding field variations by the use of analogue techniques are discussed, and preliminary experiments on field and trajectory determinations using a resistance network and a two-dimensional field-plotter are described. These techniques are able to give a valuable qualitative idea of the effects arising from various topographical features of the specimen end-form.

Simulation of steady state fluid flow in pipes

After outlining some of the problems associated with the design of fluid flow networks a brief survey is made of the methods whereby such systems have been simulated. The use of analogue techniques for this purpose is discussed and an attempt has been made to compare the various methods proposed. As a result of this study certain improvements were considered to be worth seeking, and a new type of simulator is described based on the exponential family of pipe resistance laws. A novel feature is the independent control of simulated length and diameter.

The Use of Analog Techniques in Binary Arithmetic Units

A new computing element is described in which binary numbers are added by means of analog techniques. It is shown that when this element, which will be called a quantiser, is used, the design of arithmetic units for digital computers is considerably simplified. In particular, it is possible to build simple parallel adders and multipliers which do not require any external programming and which may be directly interconnected to form networks to carry out specific calculations. As these arithmetic units are self-contained the computing network may have any number of interconnected parallel paths, and so may simultaneously test many alternative hypotheses at any step in the computation. Experimental quantisers and methods of interconnecting them to form arithmetic units are described. Speed of operation and factors likely to limit performance are discussed.

Scanning patterns for automatic track and event recognition

The difficulties of constructing a high-resolution fast programable access (FPA) scanner and the possible use of analog techniques in performing the basic operations of track recognition are discussed. Methods for programable CRT spot positioning, a universal FPA scanner using optical multiplication, and a restricted FPA scanner using differential deflection are considered. A star pattern scanner intended for scanning a small section of the total field at constant velocity along straight lines in many different directions in each revolution is described. (A.G.W.)