Modeling and simulation

About: Modeling and simulation is a research topic. Over the lifetime, 10273 publications have been published within this topic receiving 111550 citations.

A Collective Study on Modeling and Simulation of Resistive Random Access Memory

Abstract: In this work, we provide a comprehensive discussion on the various models proposed for the design and description of resistive random access memory (RRAM), being a nascent technology is heavily reliant on accurate models to develop efficient working designs and standardize its implementation across devices. This review provides detailed information regarding the various physical methodologies considered for developing models for RRAM devices. It covers all the important models reported till now and elucidates their features and limitations. Various additional effects and anomalies arising from memristive system have been addressed, and the solutions provided by the models to these problems have been shown as well. All the fundamental concepts of RRAM model development such as device operation, switching dynamics, and current-voltage relationships are covered in detail in this work. Popular models proposed by Chua, HP Labs, Yakopcic, TEAM, Stanford/ASU, Ielmini, Berco-Tseng, and many others have been compared and analyzed extensively on various parameters. The working and implementations of the window functions like Joglekar, Biolek, Prodromakis, etc. has been presented and compared as well. New well-defined modeling concepts have been discussed which increase the applicability and accuracy of the models. The use of these concepts brings forth several improvements in the existing models, which have been enumerated in this work. Following the template presented, highly accurate models would be developed which will vastly help future model developers and the modeling community.

3D modeling and simulation of 2G HTS stacks and coils

Abstract: Use of 2G HTS coated conductors in several power applications has become popular in recent years. Their large current density under high magnetic fields makes them suitable candidates for high power capacity applications such as stacks of tapes, coils, magnets, cables and current leads. For this reason, modeling and simulation of their electromagnetic properties is very desirable in the design and optimization processes. For many applications, when symmetries allow it, simple models consisting of 1D or 2D representations are well suited for providing a satisfying description of the problem at hand. However, certain designs such as racetrack coils and finite-length or non-straight stacks, do pose a 3D problem that cannot be easily reduced to a 2D configuration. Full 3D models have been developed, but their use for simulating superconducting devices is a very challenging task involving a large-scale computational problem. In this work, we present a new method to simulate the electromagnetic transient behavior of 2G HTS stacks and coils. The method, originally used to model stacks of straight superconducting tapes or circular coils in 2D, is now extended to 3D. The main idea is to construct an anisotropic bulk-like equivalent for the stack or coil, such that the geometrical layout of the internal alternating structures of insulating, metallic, superconducting and substrate layers is reduced while keeping the overall electromagnetic behavior of the original device. Besides the aforementioned interest in modeling and simulating 2G HTS coated conductors, this work provides a further step towards efficient 3D modeling and simulation of superconducting devices for large-scale applications.

Modeling and simulation of oscillator-based random number generators

Abstract: The design of integrated-circuit random number generators is receiving increased attention for the purpose of secure communications. Many high-speed cryptographic circuit-systems require a nondeterministic source of random bits. The security of these systems depends on the predictability or level of randomness of the generated bit stream. One popular method of generating random bits is to use the random frequency variations of free-running ring oscillators. This paper presents a behavioral model for the simulation of oscillator-based random number generators. The method of random number generation using oscillators is described and important design issues are stated. A model is developed and simulation results are presented for the purpose of addressing these design issues.

Theoretical evaluation of trans-critical CO2 systems in supermarket refrigeration. Part I: Modeling, simulation and optimization of two system solutions

Abstract: Using CO2 trans-critical system solutions in supermarket refrigeration is gaining interest with several installations already running in different European countries. Using a computer simulation mo ...

Measurement-based system for modeling and simulation of active semiconductor devices over an extended operating frequency range

Abstract: A modeling system for active semiconductor devices, such as gallium arsenide field effect transistors, for nonlinear (e.g., harmonic balance) circuit simulation. The model enables fast and unambiguous construction (model generation) by explicit calculations applied to raw device response data obtained using an adaptive, automated data acquisition system employed to characterize the device. The automated data acquisition system obtains the data adaptively, taking more data where nonlinearities are most severe and within a calculated, safe operating range of the device. The system converts conventional d.c. and S-parameter data directly into a detailed, device-specific, large-signal model. The system is extremely fast and replaces the need for conventional parameter extraction based on circuit simulation and optimization techniques. The measurement-based model improves large-signal simulation accuracy over an extended operating frequency range, because the model nonlinearities are explicitly constructed from device response data. The model is non quasi-static in that it accounts for frequency dispersion effects. Scaling rules allow devices of various geometries to be simulated from measurements on a single device. Therefore, the model is general, being technology and process independent in that the same calculation procedure applies to any device for which the equivalent circuit is valid. The model implementation in the automated data acquisition system, model generator, and harmonic balance (nonlinear) circuit simulator provides an efficient, practical system for state-of-the-art nonlinear circuit design.