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Making Sounds with Analogue Electronics
Published in Russ Martin, Sound Synthesis and Sampling, 2012
This link between a physical experiment and the numbers, which can be used to describe it, is also significant because the first analogue synthesizers, and in fact the first computers, were analogue not digital. An analogue computer is a device that is used to solve mathematical problems by providing an electrical circuit which behaves in the same way as a real system, and then observing that happens when some of the parameters are changed. A simple example is what happens when two containers filled with water are connected together. This can be modelled by using an integrator circuit: a capacitor in a feedback loop (Figure 3.2.2). A step voltage applied to the integrator input simulates pouring water into one container – the voltage at the output of the integrator will rise steadily until the voltage is the same as the applied voltage, and then stops. If the integrator time constant is made larger, which is equivalent to reducing the flow of water between the containers (or making the second container larger), then the integrator will take longer to reach a steady state after a step voltage has been applied.
Hardware and Implementation
Published in Naim A. Kheir, Systems Modeling and Computer Simulation, 2018
Sajjan G. Shiva, Mahmoud Mohadjer
Analog computers are capable of processing analog signals directly. It should be noted that the real world is usually analog in nature, and analog computers tend to be faster and more versatile than digital computers in simulating dynamic real-world systems. The components of analog computers are amplifiers and integrators, and they are programmed by interconnecting these components by patch chords. This programing mode is rather inconvenient and less flexible compared to that of digital computers. We provide a brief comparison of the two types of computers with respect to simulation.
Computerized Systems Validation
Published in James Agalloco, Phil DeSantis, Anthony Grilli, Anthony Pavell, Handbook of Validation in Pharmaceutical Processes, 2021
There are basically two types of computers, analog and digital. The analog computer does not perform computing directly with numbers. It accepts electrical signals of varying magnitude (analog signals) that in practical use are analogous to or represent some continuous physical magnitude such as pressure, temperature, etc. Analog computers are sometimes used for scientific, engineering, and process-control purposes. In the majority of industry applications used today, analog values are converted to digital form by an analog to digital converter and processed by digital computers.
A Generalized Numerical/Experimental Distributed Simulation Framework
Published in Journal of Earthquake Engineering, 2020
The numerical-experimental hybrid simulation method has been developed in the past four decades. The first hybrid simulation was reported in Hakuno et al. [1969], where an analog computer was used to solve an equation of motion and an inelastic cantilever was used as a physical specimen. Takanashi et al. [1975] first used a digital computer for hybrid simulations. Since then, the hybrid simulation method has been steadily developed through the 1980s and the 1990s. With the advancement of easy-to-use yet high-performance electronic equipment, such as high-resolution and high-speed Analog to Digital Converter (ADC) and Digital to Analog Converter (DAC) converters or SCRAMNet, and the connectivity to the Internet by most computers, the topic of hybrid simulation gained attention of many researchers. Several frameworks have been developed to foster hybrid simulations, including UI-SimCor [Kwon et al., 2008], OpenFresco [Takahashi and Fenves, 2006], HybridFEM [Karavasilis et al., 2008], Mercury [Saouma et al., 2012], P2P [Pan et al., 2006], ISEE [Wang et al., 2007; Yang et al., 2007], etc.
Literature review of building peak cooling load methods in the United States
Published in Science and Technology for the Built Environment, 2018
Chunliu Mao, Juan-Carlos Baltazar, Jeff S. Haberl
Historically, the foundation of all the simplified methods can be traced back to 1944 sol-air temperature method developed by Mackey and Wright. Around the same time, the thermal R/C network started to arise, which was used to calculate dynamic heat transfer through the building walls by Paschkis (1942), to model the house by Linvill and Hess (1944), and by Buchberg (1958). In Buchberg's ASHRAE project, the heat balance calculations were performed at each node of the thermal network, which required one of the first analog computer simulations.