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Analog In-Memory Computing (AIMC) is a promising approach to reduce the latency and energy consumption of Deep Neural Network (DNN) inference and training. However, the noisy and non-linear device characteristics and the non-ideal peripheral circuitry in AIMC chips require adapting DNNs to be deployed on such hardware to achieve equivalent accuracy to digital computing. In this Tutorial, we provide a deep dive into how such adaptations can be achieved and evaluated using the recently released IBM Analog Hardware Acceleration Kit (AIHWKit), freely available at https://github.com/IBM/aihwkit. AIHWKit is a Python library that simulates inference and training of DNNs using AIMC. We present an in-depth description of the AIHWKit design, functionality, and best practices to properly perform inference and training. We also present an overview of the Analog AI Cloud Composer, a platform that provides the benefits of using the AIHWKit simulation in a fully managed cloud setting along with physical AIMC hardware access, freely available at https://aihw-composer.draco.res.ibm.com. Finally, we show examples of how users can expand and customize AIHWKit for their own needs. This Tutorial is accompanied by comprehensive Jupyter Notebook code examples that can be run using AIHWKit, which can be downloaded from https://github.com/IBM/aihwkit/tree/master/notebooks/tutorial. [ABSTRACT FROM AUTHOR]

In recent years, numerous researches have been carried out to investigate and verify how concept maps could be effective in learning management systems. This paper discusses the use of dynamic concept maps (DCMs) as a tool to encourage remediation processes among digital artefacts and analog resources and, consequently, to enhance learning processes and improve their effectiveness. The DynaMap remediation approach (DMRA) intends to propose a possible interpretation of this process by using Vygotsky's historical-cultural approach, enriched and contaminated by the perspective of mutual remediation of Bolter and Grusin inspired to McLuhan's theories. The research carried out in the last five years shows how this methodology (DMRA) has positively influenced study times and learning outcomes of the engaged students. [ABSTRACT FROM AUTHOR]

The support for local variables in SystemVerilog assertions significantly enhances its expressive power. Handling local variables in analog and mixed-signal (AMS) extensions of assertion languages is tricky due to the dense time interpretation of AMS assertions, and has not been adequately treated in existing literature. This paper presents an approach for interpreting local variables in AMS assertions during simulation and a tool flow that works with standard mixed-mode simulators. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Model of sound absorbing coefficient of the multilayer microperforated panel was constructed. • Parameters of multilayer microperforated panel were optimized by cuckoo search algorithm. • Verifications of optimal parameters were conducted by simulation based on finite element method. • Optimal design of multilayer microperforated panel was validated by testing experiments. Abstract Sound absorption performance of the multilayer microperforated panel can be improved through optimal design of structural parameters. Theoretical model of sound absorbing coefficient of the multilayer microperforated panel with different layers was constructed according to Maa's theory. Structural parameters of the multilayer microperforated panel with layer number from 1 to 8 were optimized through the cuckoo search algorithm with constraint conditions. Preliminary verifications of the achieved optimal parameters were conducted by the analog simulation according to the finite element method. The obtained optimal design of multilayer microperforated panel with no more than 4 layers was finally validated by testing experiments based on the standing wave method, and the optimal average sound absorbing coefficients in the frequency range of 100–6000 Hz were 57.21%, 66.29%, 68.33%, and 69.36%, respectively. Through theoretical modeling, parameter optimization, analog simulation, and experimental validation, an effective method for development of the desired sound absorber was proposed, which will be propitious to promote the applications of the multilayer microperforated panel products in the field of noise reduction. [ABSTRACT FROM AUTHOR]

This paper discusses the application of Analogue Computers to the subject of Production Control and allied topics. A review is made of research applications of Analogue Computers to Economics, Operational Research and Production Control. The role of the Analogue Computer as applied to Production Control problems in British industry is also discussed. The probable course of future research and applications of analogue computation methods to problems occurring in Production Control is considered; a method of approach is proposed and an Analogue Inventory Policy Simulator described. [ABSTRACT FROM AUTHOR]

Monte Carlo (MC) method is widely used in radiation shielding calculations with the advantages of high fidelity geometry modeling, complex radiation source description and continuous-energy cross sections. The deep-penetration problem prevents the further application of MC method in radiation transport calculation. It is difficult to obtain reliable results for a certain tally due to the poor particle statistics. Thus, effective local variance reduction (LVR) technique must be applied to bias particles toward tally region. In this paper, combined with weight window technique, a new local variance reduction method based on anti-forward calculation has been proposed. The detector tally in forward run is set as source position in anti-forward run. Anti-forward calculation flux has been used to construct weight window parameters. From the numerical test calculations, a speedup of 420 times has been achieved compared to the analog simulation. More computational time has been spent on one Monte Carlo source particle, but more tally information has been collected. The goal of local variance reduction has been achieved. The proposed local variance reduction technique could be a useful tool in MC deep-penetration shielding calculation. [ABSTRACT FROM AUTHOR]

Researchers building spiking neural networks face the challenge of improving the biological plausibility of their model networks while maintaining the ability to quantitatively characterize network behavior. In this work, we extend the theory behind the neural engineering framework (NEF), a method of building spiking dynamical networks, to permit the use of a broad class of synapse models while maintaining prescribed dynamics up to a given order. This theory improves our understanding of how low-level synaptic properties alter the accuracy of high-level computations in spiking dynamical networks. For completeness, we provide characterizations for both continuous-time (i.e., analog) and discrete-time (i.e., digital) simulations. We demonstrate the utility of these extensions by mapping an optimal delay line onto various spiking dynamical networks using higher-order models of the synapse. We show that these networks nonlinearly encode rolling windows of input history, using a scale invariant representation, with accuracy depending on the frequency content of the input signal. Finally, we reveal that these methods provide a novel explanation of time cell responses during a delay task, which have been observed throughout hippocampus, striatum, and cortex. [ABSTRACT FROM AUTHOR]

Natural gas is currently being produced from shales of the Montney and Liard basins in western Canada. Production requires hydraulic fracturing due to the low permeability of the shales in the basins. Stratigraphically equivalent shales are present in the northern Canadian Rocky Mountains. Thermal springs with notable hydrocarbon concentrations occur where large-scale faults intersect the same shale units that are the focus of gas development, indicating that under certain circumstances, connection of deep fractured shales to the land surface is possible. To constrain these conditions, simulations were conducted for the spring with the highest hydrocarbon flux (Toad River Spring), results of which indicate that in order to supply sufficient water to a fault to support measurable advection, the effective permeability of the shales in these structurally deformed areas must be one to four orders of magnitude higher than in areas of active gas production to the east. The spatial scale of enhanced permeability is much greater than that which is achieved by hydraulic fracturing and the mechanism of maintaining high pressures at depth is more persistent in time. Examination of groundwater velocities suggests that upward migration of solutes from hydraulic fracturing may take decades to centuries. Results also indicate that any temperature anomaly will be associated with transport along a fault at such velocities. No such temperature anomaly has been documented in regions with unconventional oil and gas development to date. Such an anomaly would be diagnostic of a deep solute source. [ABSTRACT FROM AUTHOR]

The recently modified Pascal function is further exploited in this paper in the design of passive analog filters. The Pascal approximation has non-equiripple magnitude, in contrast of the most well-known approximations, such as the Chebyshev approximation. A novelty of this work is the introduction of a precise method that calculates the coefficients of the Pascal function. Two examples are presented for the passive design to illustrate the advantages and the disadvantages of the Pascal approximation. Moreover, the values of the passive elements can be taken from tables, which are created to define the normalized values of these elements for the Pascal approximation, as Zverev had done for the Chebyshev, Elliptic, and other approximations. Although Pascal approximation can be implemented to both passive and active filter designs, a passive filter design is addressed in this paper, and the benefits and shortcomings of Pascal approximation are presented and discussed. [ABSTRACT FROM AUTHOR]

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via table-top experiments using low-cost or home-made instruments. The tenth article in this series demonstrates the use of the area-minimization property of soap films in the computation of analog solutions to mathematical problems. [ABSTRACT FROM AUTHOR]

Indoor air temperature, RH and moisture content in a enclosed space with / without HCM were simulated using the effective moisture penetration depth model under typical climate of Nanjing in winter and indoor periodic moisture load boundary conditions. The results show that HCM can effectively weaken the influence of outdoor climate fluctuation and indoor periodic moisture load change on indoor air temperature and RH. HCM can not only make indoor air temperature change slowly and uniformly in winter but also control indoor air humidity parameters in a narrow range. The thickness of HCM should be equal to the optimum thickness (0.002 m).When the thickness of HCM is 0.002 m, natural ventilation space has more ways to gain heat than enclosed space, and thus the temperature in natural ventilation space is higher than that in enclosed space. [ABSTRACT FROM AUTHOR]

The aim of this paper is to introduce a matrix approach for approximate solving of non-commensurate fractional variable order linear control systems in state-space form. The approach is based on switching schemes that realize variable order derivatives. The obtained numerical solution is compared with simulation and analog model results. [ABSTRACT FROM AUTHOR]

In this work we carry out extensive numerical study of a Watt centrifugal governor system model, and we also implement an electronic circuit by analog computation to experimentally solve the model. Our numerical results show the existence of self-organized stable periodic structures (SPSs) on parameter-space of the largest Lyapunov exponent and isospikes of time series of the Watt governor system model. A peculiar hierarchical organization and period-adding bifurcation cascade of the SPSs are observed, and this self-organized cascade accumulates on a periodic boundary. It is also shown that the periods of these structures organize themselves obeying the solutions of Diophantine equations. In addition, an experimental setup is implemented by a circuitry analogy of mechanical systems using analog computing technique to characterize the robustness of our numerical results. After applying an active control of chaos in the experiment, the effect of intrinsic experimental noise was minimized such that, the experimental results are astonishingly well in agreement with our numerical findings. We can also mention as another remarkable result, the application of analog computing technique to perform an experimental circuitry analysis in real mechanical problems. [ABSTRACT FROM AUTHOR]

The design of a new configurable structured array (CSA) is considered. The CSA is intended for development of multichannel (up to eight channels) integrated circuits of the analog interfaces of sensors. An example of operational amplifier is used to show that circuit synthesis with allowance for radiation-induced variations in characteristics of complementary bipolar transistors may provide minor degradation of parameters of the analog ICs after ionizing irradiation. Electrical schemes of the CSA analog components and experimentally measured parameters are presented. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a q-analog of the bi-periodic Lucas sequence, called as the q-bi-periodic Lucas sequence, and give some identities related to the q-bi-periodic Fibonacci and Lucas sequences. Also, we give a matrix representation for the q-bi-periodic Fibonacci sequence which allow us to obtain several properties of this sequence in a simple way. Moreover, by using the explicit formulas for the q-bi-periodic Fibonacci and Lucas sequences, we introduce q-analogs of the bi-periodic incomplete Fibonacci and Lucas sequences and give a relation between them. [ABSTRACT FROM AUTHOR]

Analog quantum simulators (AQS) will likely be the first nontrivial application of quantum technology for predictive simulation. However, there remain questions regarding the degree of confidence that can be placed in the results of AQS since they do not naturally incorporate error correction. Specifically, how do we know whether an analog simulation of a quantum model will produce predictions that agree with the ideal model in the presence of inevitable imperfections? At the same time there is a widely held expectation that certain quantum simulation questions will be robust to errors and perturbations in the underlying hardware. Resolving these two points of view is a critical step in making the most of this promising technology. In this work we formalize the notion of AQS reliability by determining sensitivity of AQS outputs to underlying parameters, and formulate conditions for robust simulation. Our approach naturally reveals the importance of model symmetries in dictating the robust properties. To demonstrate the approach, we characterize the robust features of a variety of quantum many-body models. [ABSTRACT FROM AUTHOR]

The rings over which every square matrix is representable as a sum of a nilpotent matrix and a q-potent matrix, where q is a positive integer power of a prime, are studied. As consequences, matrix analogs of the little Fermat theorem are obtained. [ABSTRACT FROM AUTHOR]

The paper describes a multipath signal acquisition and processing system that can acquire 16-path analog signals and has real time data processing ability. The paper: i) explains the design of multipath signal acquisition based on FPGA, and ii) gives the design of the real-time processing of data by digital signal processor (DSP). The system: i) produces control sequence signals by FPGA, ii) improves system acquisition speed and stability by the characteristics of high clock frequency and abundant I/O resources, iii) carries out filter processing on the collected data by strong DSP data processing ability, and iv) removes environment noise. The design: i) aims at the acquisition and processing of only 16-path signals, ii) it can be easily extended to acquire more analog signals by adding more multipath analog selection switches, iii) it only needs to increase the control timing sequence of chip selection signal for multiplexer switch in FPGA. The design scheme has favorable expandability and universality. [ABSTRACT FROM AUTHOR]

A 12-bit 104 MS/s successive approximation register analog-to-digital converter (SAR ADC) is developed for a digitally-assisted wireless transmitter system for use in cellular applications. A power-on calibration method is implemented to correct capacitor DAC mismatch and reduce capacitor size, thereby lowering the current consumption of the input buffer and reference generator. The total capacitor size is reduced to 0.6 pF, from the 3.6 pF required for 12-bit matching. The ADC analog core area is 0.003 mm2. The proposed method achieves 88 dB SFDR at 26 MHz sampling rate and 76.2 dB SFDR at 104 MHz sampling rate after calibration. The measured DNL and INL are 0.5 LSB and 1.1 LSB, respectively. The ADC achieves both high speed and low power by combining several features, namely digital calibration, redundancy, asynchronous bit-cycling, monotonic switching, 25% duty-cycle sampling period, 3 dB input gain, and a fully dynamic comparator. The power consumption from 1.2 V/1.1 V supplies is 0.88 mW for a single ADC core and 6.1 mW for the entire I/Q ADC, including the reference generator and input buffers. The ADC is fabricated in 28 nm CMOS. [ABSTRACT FROM PUBLISHER]

The formation of the relief of fault zones is considered in relation to the evolution of their internal structure during faulting. The study was carried out by analog modeling with subsequent digital elevation modeling of the experimental surface of the deformed sample. The vertical displacement gradient was calculated based on the digital elevation models. It has been found that the relief of strike-slip and extensional fault zones depends on their internal structure. Each element of the internal structure makes its own contribution to the relief formation. The process depends on experimental conditions, such as the viscosity of the model material and the model deformation rate. The relief of the fault zone is different at each of three main stages of its formation. [ABSTRACT FROM AUTHOR]

Confined impinging jets (CIJs) are highly efficient mixers. The scales of mixing in CIJs are controlled by the opposed jets interaction. A mechanistic model is described here, which accurately predicts the impinging position of the opposed jets for a large range of flow rate ratios. The impinging point position is shown to impact the dynamic properties of the flow and the achieved mixing quality. The opposed jets kinetic energy ratio is shown to have a critical impact on mixing, similar to the Reynolds number. A mixing chamber design relation is proposed and verified for the opposed injectors diameters ratio [ABSTRACT FROM AUTHOR]

The basic theory and main features of operating modal analysis method have been elaborated, and then by using this method, the parameters of low-order natural characteristics of some wheeled and tracked self-propelled guns have been obtained. By two examples, the application of the operating modal analysis method for the development of self-propelled gun has been introduced. According to the result of operating modal analysis, for some wheeled self-propelled gun, "beat vibration" between the first-order natural characteristics and firing frequency of the gun has been identified, and further research indicates that the primary cause of the "beat vibration" is that the stiffness of the cradle is too weak which enlarges the vibratory response of the muzzle. With the reinforcement of the cradle, the testing result of firing indicates that the vibratory response of the muzzle is reduced obviously, and that the firing dispersion is much better than before. In order to certificate the accuracy of its dynamic model, for some tracked self-propelled guns, the natural characteristics of the whole gun through a comparison of the operating modal analysis and finite element calculation have been specified, and then according to the results of operating modal analysis, the dynamic model of the gun has been meliorated, and the natural characteristics of the gun by the finite element calculation are consistent with those by the operating modal analysis. This indicates that the model of the gun is correct with the vibratory response of the whole gun under seven running fire simulated, and that the error of vibratory response of the muzzle between firing testing and analog simulation does not exceed 15 %. [ABSTRACT FROM AUTHOR]

The paper describes the design and implementation of the system allowing the testing of the lithium-iron-phosphate (LiFePO4) cell parameters during long-term loading. Manufacturers and retailers, in particular, accentuate their beneficial properties -- the possibility of charging and discharging by high currents, minimum influence of the discharge time on capacity, long durability. At the same time, their operational conditions are a lot more strictly defined than those for other types of accumulators. The proposed testing system enables loading the accumulators, consisting of several cells, by periodic discharging and charging processes with various operating currents and various levels of cell discharging. The charging and discharging process control is fully automated; the measuring of the cell operational state is performed automatically during charging and discharging. The data is recorded, and continuously evaluated for the purposes of process management. The measurements enable the comparison of the catalogue data with the parameters of the real products. The testing system design is based on the application of a digital control block, which is completed with an analog control block. The core of the digital control unit is a control computer equipped with a multifunctional input-output card and an array of logically controlled circuit breakers. An accumulator management algorithm, implemented as a control program of the computer, ensures the operation of the accumulator in subsequent charging and discharging periods. The actual accumulator control is based on the evaluations of voltage levels at the cell terminals. [ABSTRACT FROM AUTHOR]

This two part article consists of a brief biography of Marian Boykan Pour-El followed by a summary of her mathematical achievements. [ABSTRACT FROM AUTHOR]

The use of working standards, which employ digital methods of reproducing the unit of the harmonic coefficient to check instruments for measuring nonlinear distortions with analog components, is considered. The results of measurements of a signal with a normalized harmonic coefficient by analog and digital methods are compared. [ABSTRACT FROM AUTHOR]

Quantum simulation of many-body systems are one of the most interesting tasks of quantum technology. Among them is the preparation of a many-body system in its ground state when the vanishing energy gap makes the cooling mechanisms ineffective. Adiabatic theorem, as an alternative to cooling, can be exploited for driving the many-body system to its ground state. In this paper, we study two most common disorders in quantum dot arrays, namely exchange coupling fluctuations and hyperfine interaction, in adiabatic preparation of ground state in such systems. We show that the adiabatic ground-state preparation is highly robust against those disorder effects making it a good analog simulator. Moreover, we also study the adiabatic quantum information transfer, using singlet-triplet states, across a spin chain. In contrast to ground-state preparation the transfer mechanism is highly affected by disorder and in particular, the hyperfine interaction is very destructive for the performance. This suggests that for communication tasks across such arrays adiabatic evolution is not as effective and quantum quenches could be preferable. [ABSTRACT FROM AUTHOR]

We consider resource allocation for semi-elastic applications, such as mobile video conferencing, which require a maximum outage. We represent the performance of a session by a sigmoid utility function of the average bit rate over a time window consisting of many slots. The goal is to maximize the total expected utility of all active users. A principal challenge is the difference in timescales: The outage is measured over sessions, whereas the average bit rate is measured over a time window such as a group of pictures. We propose that these differences in timescales can be elegantly addressed by shadow prices: a price per unit average rate over each time window and a price per unit outage. We further propose that the price per unit average rate depends on combined path loss and shadowing but not on fast fading. We show that resources can be efficiently allocated if the base station chooses prices based on the total demand and if the users respond by choosing average rates. The performance of our algorithm is illustrated by simulation results. [ABSTRACT FROM PUBLISHER]

We consider excited random walks (ERWs) on integers in i.i.d. environments with a bounded number of excitations per site. The emphasis is primarily on the critical case for the transition between recurrence and transience which occurs when the total expected drift δ at each site of the environment is equal to 1 in absolute value. Several crucial estimates for ERWs fail in the critical case and require a separate treatment. The main results discuss the depth and duration of excursions from the origin for |δ| = 1 as well as occupation times of negative and positive semi-axes and scaling limits of ERW indexed by these occupation times. We also point out that the limiting proportions of the time spent by a non-critical recurrent ERW (i.e. when |δ| < 1) above or below zero converge to beta random variables with explicit parameters given in terms of d. The last observation can be interpreted as an ERW analog of the arcsine law for the simple symmetric random walk. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper analyzes the stability criteria for closed loop tracking in a GNSS receiver using Bode analysis techniques. This defines the stable limits of predetection integration time (T) for a given loop filter design, including its order and noise bandwidth (Bn) in combination with all of the other components involved in the closed receiver tracking loop. The loop filter design used in this paper is based on a traditional analog design converted to digital using the bilinear transform. The shortcomings of this traditional design are briefly described, but the traditional design suffices for small T and ample phase margin. Clearly, a pilot channel in modern GNSS signals permits much longer T than allowed by the original GPS data channels, but the stability assurance must be considered in either case. The methodology applies to both data (Costas) and data-less (pilot) tracking loops. Additional insight is provided using the results of this analysis. Copyright © 2014 Institute of Navigation. [ABSTRACT FROM AUTHOR]

The review considers the results of computer simulation of conformational transformations of 1,3-dioxanes, 1,3,2-dioxaborinanes, and 1,3-dioxa-2-silacyclohexanes in terms of HF, DFT, and MP2 quantum chemical approximations. The effect of intermolecular association with water and other substrates on the conformational transformations is discussed. [ABSTRACT FROM AUTHOR]

The relative magnitude (or intensity) of an event can have direct implications on timing estimation. Previous studies have found that greater magnitude stimuli are often reported as longer in duration than lesser magnitudes, including Arabic digits (Xuan, Zhang, He. & Chen, 2007). One explanation for these findings is that different quantitative dimensions (size, intensity, number) are processed and represented according to a common analog magnitude system (Walsh, 2003). In the current study, we examined whether there were commonalities in how people judge the intervals of time occurring between discrete stimuli of different magnitudes across a variety of quantitative dimensions, which included number, size, and color saturation. It was found that duration judgments increased systematically as the overall magnitude difference between sequentially presented stimuli increased. This finding was robust against manipulations to the direction of the sequence, or whether the sequence followed ordered (continuous) or nonordered (discontinuous) pattern trajectories. [ABSTRACT FROM AUTHOR]

We describe a variational problem on a surface of a Euclidean space under a distance constraint. We provide sufficient and necessary conditions for the existence of bifurcation points, generalizing Skrypnik's analog described in [P. Vyridis, Int. J. Nonlinear Anal. Appl. 2 (2011), 1{10]. The problem in local coordinates corresponds to an elliptic boundary value problem. [ABSTRACT FROM AUTHOR]

Abstract: Most of the low-level radio frequency (LLRF) systems are being developed well before the machines are being set up and ready to be commissioned. Therefore it is imperative to be able to test and evaluate their functionality and performance in the laboratory, before the instrument is installed in the final configuration. Real accelerator cavities are very expensive and frequency-dependent, hence impractical for mass factory testing of instrumentation. As an alternative, we developed an analog cavity simulator. The article gives an explanation of the main design concept, some key considerations of its implementation in order to reach the required specifications, and presents the test results, showing the simulator performance. [Copyright &y& Elsevier]

We have aimed to systematically extract analog series with related core structures from multi-target activity space to explore target promiscuity of closely related analogous. Therefore, a previously introduced SAR matrix structure was adapted and further extended for large-scale data mining. These matrices organize analog series with related yet distinct core structures in a consistent manner. High-confidence compound activity data yielded more than 2,300 non-redundant matrices capturing 5,821 analog series that included 4,288 series with multi-target and 735 series with multi-family activities. Many matrices captured more than three analog series with activity against more than five targets. The matrices revealed a variety of promiscuity patterns. Compound series matrices also contain virtual compounds, which provide suggestions for compound design focusing on desired activity profiles. [ABSTRACT FROM AUTHOR]

An analog of the Carnot engine reversibly operating within the framework of pure-state quantum mechanics is discussed. A general formula is derived for the efficiency of such an engine with an arbitrary confining potential. Its expression is given in terms of an energy spectrum and shows how the efficiency depends on a potential as the analog of a working material in thermodynamics, in general. This non-universal nature results from the fact that there exists no analog of the second law of thermodynamics in pure-state quantum mechanics where the von Neumann entropy identically vanishes. A special class of spectra, which leads to a common form of the efficiency, is identified. [ABSTRACT FROM AUTHOR]

With the recent upsurge in experimental efforts toward fabrication of short-channel graphene field-effect transistors (GFETs) for analog and high-frequency RF applications—where the advantages of distinctive intrinsic properties of gapless graphene are expected to be leveraged—a critical understanding of the factors affecting both output and transfer characteristics is necessary for device optimization. Analyzing the device characteristics through ballistic electronic transport simulations within the nonequilibrium Green's function formalism, we show that a doping in the drain underlap region can significantly improve the quasi-saturation behavior in the GFET output characteristics and, hence, the output resistance and intrinsic gain. From this understanding, we provide a unified and coherent explanation for seemingly disparate phenomena—quasi-saturation and the recently reported three-terminal negative differential resistance in GFETs. We also investigate the scaling behavior of cutoff frequency and comment on some of the observed scaling trends in recent experiments. [ABSTRACT FROM AUTHOR]

Abstract: A hierarchical sizing and biasing methodology for analog firm intellectual properties (IPs) is presented. An analog firm IP designates an unsized transistor netlist of an analog circuit. The methodology sizes and biases an analog firm IP by automatically generating suitable sizing procedures. The generated procedures respect topology constraints, designer''s hypotheses and design constraints. The procedures are represented using dependency graphs. The methodology deals with different aspects of analog design problems such as MOS inversion level control, insufficient or excess design parameters, systematic offset and negative-feedback. Its application in both fields of analog synthesis and simulation is outlined. The proposed methodology has been successfully used to size, bias and analyze two analog IPs: a single-ended two-stage operational amplifier and a fully differential transconductor. This is performed using 130nm CMOS technology with . The results prove the effectiveness and precision of the proposed methodology. [Copyright &y& Elsevier]

A 0.6-V subthreshold-leakage suppressed fully differential CMOS switched-capacitor amplifier using Analog T-switch scheme in a standard 0.18 μm CMOS technology is presented. The circuit design of major building blocks is described. The performance of this circuit is demonstrated by experimental results. The experimental results confirm the capability of Analog T-switch scheme to fulfill circuit requirements. [ABSTRACT FROM AUTHOR]

In designing analog integrated circuits, the step of selecting device sizes and biases is crucial to enhance the final performance, power, and yield of the circuits. In manual design flows, the designer first selects bias voltage and branch current values, and then converts to widths and lengths via first-order equations. This is the operating-point driven (OP) formulation. Using OP makes it easy for the designer to maintain insight of the effect of design variables (voltage, currents) on performance, in addition to simplifying the sizing problem. In contrast to manual, automated sizing approaches in the computer-aided design (CAD) literature predominantly manipulate device sizes directly. While simpler from a CAD perspective, the direct-sizing approach misses the benefits of OP-insight and a simpler problem that would lead to faster convergence and better results. We believe that the OP formulation is underused, because of lack of familiarity, inconvenience, and underappreciation of its benefits. This investigation aims to resolve that and help to improve CAD practice, by reviewing the literature on OP that has been accumulated over the decades, and describing the variants, applications, and benefits of OP. [ABSTRACT FROM AUTHOR]

A discrete model of Bogomolny equations based on the combinatorial structure of a double complex is constructed. It is shown that the difference analogs of the Bogomolny equations can be obtained from the discrete self-dual Yang-Mills equations and preserve the geometric properties of the corresponding equations of continual theory. [ABSTRACT FROM AUTHOR]