Analog Counterparts Research Articles

Comparing the Accuracy of Conventional Gypsum and 3D-Printed Dental Casts Using Three-Dimensional Analysis.

Dental impressions and casts play a critical role in dental care, facilitating diagnoses and the fabrication of prostheses. Traditional methods of fabrication involve elastomeric materials that are more prone to errors and patient discomfort. Digital advancements offer promising alternatives, yet their accuracy and applicability to military dentistry remain under-explored. This study evaluates the accuracy of digital casts produced with material available in the Military Health System compared to conventional methods. Using a digital (n = 10) and analog (n = 10) methodology casts were fabricated from a reference cast (n = 1). The reference and cast samples were scanned with a reference scanner to generate stereolithography files. These files were used to generate full arch, single crown, fixed dental prosthesis, and inlay digital casts which were then compared using a three-dimensional (3D) comparison software to evaluate accuracy. Root mean square values were obtained, giving a quantitative evaluation of the deviation of each sample from the reference cast. Statistical analysis consisted of a Shapiro-Wilk and Levene test to account for homogeneity of variances in each group. An ANOVA and Tukey post-hoc test were used to determine differences in accuracy among the full arch and a two-way ANOVA and Tukey post-hoc test evaluated differences in trueness among the casts of the individual preparations. Analog full arch casts had an average root mean square of 106 ±19.18 µm when examining trueness and 12 ±2.58 µm for precision. Digital full arch casts had an average root mean square of 51.9 ±5.39 µm when examining trueness and 4.2 ±1.57 µm for precision. Overall digital casts surpassed analog counterparts in accuracy. Fixed dental prostheses were found to be the only group, which showed no statistically significant difference between digital and analog. These findings validate the potential of digital workflows in enhancing the speed and accuracy of dental care in the Military Health System, while underscoring the need for further exploration and refinement in specific clinical contexts.

Robust digital voltage mode control of buck converter with enhanced tracking performance

The digital voltage controller of power converters is used because it has many advantages over its analog counterparts. Thus, in this paper, a controller of digital voltage mode is designed and analyzed for a non-isolated DC-DC buck converter in continuous conduction mode (CCM). First, an analog controller is designed using a Bode plot to achieve the desired stability margins in the frequency domain. Next, the analog controller is discretized using bilinear transformation with the pre-warping method. The characteristics of the discretized compensator can be maintained close to the corresponding analog compensator as long as a proper sampling time is selected. The digital control scheme is simulated with a nonlinear DC-DC buck converter model in MATLAB/Simulink to investigate the controller performance. The simulation results demonstrated the validation of the proposed digital voltage-mode control design approach. The developed digital controller eliminates DC error by tracking the reference voltage, achieving a fast transient response, maintaining specified stability margins, and effectively rejecting large disturbances.

Factors Affecting Digital Tool Use in Client Interaction According to Mental Health Professionals: Interview Study.

Digital tools and interventions are being increasingly developed in response to the growing mental health crisis, and mental health professionals (MHPs) considerably influence their adoption in client practice. However, how MHPs use digital tools in client interaction is yet to be sufficiently understood, which poses challenges to their design, development, and implementation. This study aimed to create a contextual understanding of how MHPs use different digital tools in clinical client practice and what characterizes the use across tools. A total of 19 Finnish MHPs participated in semistructured interviews, and the data were transcribed, coded, and inductively analyzed. We found that MHP digital tool use was characterized by 3 distinct functions: communication, diagnosis and evaluation, and facilitating therapeutic change. The functions were addressed using analog tools, digitized tools that mimic their analog counterparts, and digital tools that use the possibilities native to digital. The MHP-client communication included various media alongside face-to-face meetings, the MHPs increasingly used digitized tools in client evaluation, and the MHPs actively used digitized materials to facilitate therapeutic change. MHP tool use was generally characterized by adaptability-it was negotiated in client interactions. However, there was considerable variance in the breadth of MHPs' digital toolbox. The existing clinical practices emphasized MHP-client interaction and invited incremental rather than radical developments, which challenged the achievement of the scalability benefits expected from digital tools. MHPs use digitized and digital tools in client practice. Our results contribute to the user-centered research, development, and implementation of new digital solutions in mental health care by classifying them according to their function and medium and describing how MHPs use and do not use them.

AnalogVNN: A fully modular framework for modeling and optimizing photonic neural networks

In this paper, we present AnalogVNN, a simulation framework built on PyTorch that can simulate the effects of optoelectronic noise, limited precision, and signal normalization present in photonic neural network accelerators. We use this framework to train and optimize linear and convolutional neural networks with up to nine layers and ∼1.7 × 106 parameters, while gaining insights into how normalization, activation function, reduced precision, and noise influence accuracy in analog photonic neural networks. By following the same layer structure design present in PyTorch, the AnalogVNN framework allows users to convert most digital neural network models to their analog counterparts with just a few lines of code, taking full advantage of the open-source optimization, deep learning, and GPU acceleration libraries available through PyTorch.

Defining a Discipline: Archival Research and Practice in the Twenty-First Century, Essays in Honor of Richard J. Cox. Edited by Jeannette A. Bastian and Elizabeth Yakel. [Review

In their introduction to this volume, editors Jeannette Bastian and Elizabeth Yakel offer the thought that the maturity of a field of study may be marked by the recognition of its outstanding scholars. So far, few Festschriften honor archivists—a fact that attests to the still-recent maturing and professionalization of the discipline of archival science and its practitioners. During the career of Richard J. Cox, the honoree of this volume, archival science moved forward from many of its older practices and philosophies to become a modern, more mature, and better-defined profession. The growth of degree programs specifically offering archival education, along with the creation and adoption of archival standards and best practices at the national and international levels, continued that maturation. Cox’s career also saw the application of computer technology as a tool for both the creation and management of archival records, which introduced profound and rapid changes as the technology created an ever-increasing volume of digital materials to be added to archival repositories alongside their analog counterparts. Cox entered the field at the beginning of an era of expansive growth for the archival profession, and, when he retired 40 years later, the field had expanded and evolved considerably in response to technology and sociocultural motivators.

Spectral Breathing and Its Mitigation in Digital Fractional-N PLLs

Although digital phase-locked loops (PLLs) offer several advantages over their analog counterparts, they suffer from a major disadvantage that is rarely mentioned in published articles. The disadvantage, known as spectral breathing, is caused by component mismatches among the frequency control elements within a PLL’s digitally controlled oscillator (DCO). The mismatches introduce DCO frequency modulation nonlinearity which fluctuates and, therefore, causes erratic variations in the PLL’s measured phase noise spectrum as the DCO’s free-running frequency drifts. The phenomenon is called spectral breathing because the measured phase noise spectrum tends to slowly swell and contract over time as if taking breaths of air. During these breaths, the PLL’s phase noise often becomes severely degraded. This article presents an experimental demonstration of the spectral breathing phenomenon and its solution in a digital fractional- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> PLL. The demonstrated solution is a multi-rate dynamic element matching technique and a mismatch-noise cancellation technique that together eliminate spectral breathing.

Development of a Practicable Digital Pulse Read-Out for Dark-Field STEM.

When characterizing beam-sensitive materials in the scanning transmission electron microscope (STEM), low-dose techniques are essential for the reliable observation of samples in their true state. A simple route to minimize both the total electron-dose and the dose-rate is to reduce the electron beam-current and/or raster the probe at higher speeds. At the limit of these settings, and with current detectors, the resulting images suffer from unacceptable artifacts, including signal-streaking, detector-afterglow, and poor signal-to-noise ratios (SNRs). In this article, we present an alternative approach to capture dark-field STEM images by pulse-counting individual electrons as they are scattered to the annular dark-field (ADF) detector. Digital images formed in this way are immune from analog artifacts of streaking or afterglow and allow clean, high-SNR images to be obtained even at low beam-currents. We present results from both a ThermoFisher FEI Titan G2 operated at 300 kV and a Nion UltraSTEM200 operated at 200 kV, and compare the images to conventional analog recordings. ADF data are compared with analog counterparts for each instrument, a digital detector-response scan is performed on the Titan, and the overall rastering efficiency is evaluated for various scanning parameters.

Analog and Numerical Experiments of Double Subduction Systems With Opposite Polarity in Adjacent Segments

AbstractIn this work we study the dynamics of double subduction systems with opposite polarity in adjacent segments. A combined approach of numerical and analog experiments allows us to compare results and exploit the strengths of both methodologies. High‐resolution numerical experiments complement laboratory results by providing quantities difficult to measure in the laboratory such as stress state, flow patterns, and energy dissipation. Results show strong asymmetries in the mantle flow that produce in turn asymmetries in the trench and in the downgoing slab deformation. The mantle flow pattern varies with time; the toroidal cells between the plates evolve until merging into one unique cell when the trenches align. In that moment the maximum upward flow is observed close to the trenches. The interaction between the mantle flow produced by each subducting plate makes the rollback processes slower than in a single subduction case. This is consistent with the observed energy dissipation rate that is smaller in the double subduction system than in two single subductions. Moreover, we provide a detailed analysis on the setup and boundary conditions required to numerically reproduce the analog experiments. Boundary conditions at the bottom of the domain are crucial to reproduce their analog counterparts. Numerical results are compared to natural examples of multi‐slab subduction systems in terms of upper mantle seismic anisotropy, relative trench retreat velocities, and composition of subduction‐related magmatism.

Performance comparison between signal digitizers and low-cost digital oscilloscopes: spectroscopic, pulse shape discrimination and timing capabilities for nuclear detectors

Signal digitizers revolutionized the approach to the electronics readout of radiation detectors in Nuclear Physics. These highly specialized pieces of equipment are designed to acquire the signals that are characteristic of the detectors in nuclear physics experiments. The functions of the several modules that were once needed for signal acquisition, can now be substituted by a single digitizer. As suggested by the name, with such readout modules, signals are first digitized (i.e. the signal waveform is sampled and converted to a digital representation) and then either stored or analyzed on-the-fly. The performances can be comparable or better than the traditional analog counterparts, in terms of energy, time resolution, and acquisition rate. In this work, we investigate the use of general-purpose digital oscilloscopes as signal digitizers for nuclear detectors. In order to have a proper comparison, we employ a distributed data acquisition system (DAQ), that standardizes the interface between the hardware and the on-line data analysis. The signals, from a set of typical radiation detectors, are digitized and analyzed with the very same algorithms in order to avoid biases due to different software analysis. We compare two traditional signal digitizers (CAEN DT5725 and CAEN DT5751) to two low-cost digital oscilloscopes (Digilent Analog Discovery 2, and Red Pitaya STEMLab 125-14), in terms of their capabilities for spectroscopy (energy resolution), time resolution, pulse shape discrimination, and maximum acquisition rate.

Clock delay-based design for hysteresis programming and noise reduction in dynamic comparators

Schmitt Triggers have found wide spread use in low-power and threshold-based applications such as peak detectors and spectrum analyzers. They are formed by comparators and feedback loops and exhibit hysteresis at nominal supply voltage. When using dynamic comparators, the periodic discharge of internal capacitors prior to each decision process cancels hysteresis. In addition, dynamic comparators produce considerable noise that may affect the operation of hysteresis-based applications. Therefore, currently, Schmitt Triggers are mainly designed as static circuits at the price of less operation speed, more silicon area and higher power consumption compared to their analog counterparts. This paper presents a new low-noise dynamic comparator with programmable hysteresis. Using an advanced comparator structure, as the two-stage dual-clock latch comparator, the hysteresis could be adjusted over more than 30 mV by programming the delay between the two clocks. Moreover, the same delay has been used to reduce the switching noise. The peak kickback noise is then reduced by more than 70%. This has been achieved by designing a customized 4-bit programmable delay circuit. Although several functionalities have been added to the circuit, the proposed design include only a few extra elements with respect to the basic one. As a result, the total consumed energy at 500 MHz is 1.2 pJ/decision only, while the static power consumption is less than 65 pW.

New Design for Compact Color Screen Sets for High-End Digital Color Press.

Digital halftoning is an essential part of the process for printing color, continuous-tone content. Traditionally, the highest quality has been achieved with analog, offset lithographic presses, using color screen sets that yield periodic, clustereddot halftone patterns. Increasingly, these systems are being supplanted by digital presses that are based on either electrophotographic or inkjet marking processes. Due to the inherent instability of the electrophotographic marking process, periodic, clustered-dot halftone patterns are also widely used with such presses. However, digital presses have much lower resolution than their analog counterparts. Simply mimicking the traditional screen designs used with commercial, offset presses will result in halftone patterns that are more susceptible to moire due to the interaction between the periodic patterns used to render the different color channels. This causes instability in the printed colors. The moire can be reduced by increasing the frequency of the halftone patterns. But this may make the print appear grainier than its analog counterpart. In this paper, we introduce a principled design procedure that allows one to design color screen sets that generate periodic, clustered-dot halftone patterns that improve color stability without increasing graininess. We present experimental results to support the benefits of our new color screen set design framework.

MOS-only voltage-mode all-pass filter core suitable for IC design

In this paper, an area efficient CMOS first-order voltage-mode (VM) all-pass filter (APF) is proposed. The introduced resistorless MOS-only core circuit consists of three transistors only. For the design three transconductances and one gate-to-source capacitance of MOS transistors are sufficient instead of external passive resistors and capacitors, while the full implementation of the VM APF consists of 12 MOS transistors and one grounded capacitor only. Hence, the proposed circuit exhibits important features such as simplicity, permitting reduced chip area when integrated and wide operating frequency range compared to classical analog counterparts that require active elements employing large number of transistors. The theoretical results are in detail verified by numerous post-layout simulations using Cadence IC6 Spectre analog design environment. In the design, medium Vth transistors with 1.8 V supply voltage were used and modeled by the TSMC 180 nm CMOS process parameters available in EUROPRACTICE IC Service design kit. The post-layout simulated pole frequency of the VM APF is 4.825 MHz, the implemented layout including metal-insulator-metal on-chip capacitor occupies an area of 31.1 μm × 39.5 μm, while the total power consumption of the filter is found to be only 92.57 μW.

Undersampling Control for a DC–DC Boost and Forward Dual Active Bridge for a Single-Phase Grid-Connected PV Converter

Digital control methods and digital controllers are widely adopted in power electronics applications due to technical and economic advantages against its analog counterparts. Switched-mode power converters with switching frequencies of hundreds of kilohertz to megahertz impose a challenge such as less sampling time in which control algorithm calculations must be realized in digital implementations. Software-based controllers are designed and implemented in code lines executed in general-purpose DSP, being the most preferred digital implementation. Although high-frequency applications with more complex algorithm calculations restrict the maximum allowable sampling frequency, that can be even below the converter switching frequency. The study, analysis and design in such special condition is a main contribution of the paper. Without loss of generality, a software-based digital design under processing speed limitation is developed for two DC–DC power converters that compose a single-phase grid-connected PV converter: (1) a boost converter and (2) a unidirectional power flow DAB topology.

Accurate Synchronization of Digital and Analog Chaotic Systems by Parameters Re-Identification

The verification of the digital models of chaotic systems and processes is a valuable problem in many practical applications, such as nonlinear control and communications. In our study, we propose a hybrid technique for chaotic systems’ identification, based on the chaotic synchronization of digital and analog counterparts and a numerical optimization method used for the fine tuning of parameters. An analog circuit implementing the Rössler oscillator with digitally controlled parameters was chosen as an identification object, and the FPGA model was used as a digital counterpart for coupling and parameter retrieval. The synchronization between analog and digital chaotic models can be used to estimate the quality of an identification procedure. The results of this study clarify the practical bounds of digital and analog systems’ equivalence. They also contribute to the problem of designing technical systems possessing advantages of both analog and digital chaotic generators (e.g., a high accuracy and protection from quasi-chaotic oscillation modes).

Hybrid Analog/Digital Control of Bilateral Teleoperation Systems

Hybrid analog/digital control of bilateral teleoperation systems can lead to superior performance (transparency) while maintaining stability compared to pure analog or digital control methods. Such hybrid control is preferable over pure analog control, which is inflexible and not ideal for realizing complex teleoperation control algorithms, and pure digital control, which restricts teleoperation performance due to a well-known stability-imposed upper bound on the product of the digital controller's proportional gain and the sampling period. In this paper, a hybrid controller combining a Field programmable analog array (FPAA) based analog controller and a personal computer-based digital controller is compared in terms of performance and stability to its analog and digital counterparts. A stability analysis indicates that the addition of analog derivative term widens the range of teleoperation controls gains that satisfy the stability conditions, paving the way for improving the teleoperation performance. We also show how the hybrid controller leads to better teleoperation performance. To this end, we study the human's performance of a switch flipping task and a stiffness discrimination task in the teleoperation mode. In both tasks, the hybrid analog/digital controller allows the human operators to achieve the highest task success rates.

Do(n’t) hold your breath: rules, trust, and the human at the keyboard

The maintenance of rules within the ‘black box’ of code, away from human eyes, constitutes a major difference between digital games and the social history of their analog counterparts. Meanwhile, the incorporation of new types of human behavior into digital games’ rulesets has placed games on the cutting edge of machine surveillance technologies. This article examines several digital games that stand in opposition to these trends, by opting out of monitoring certain aspects of player behavior, and opening social dynamics of trust and cheating that digital games have historically avoided or shut down. Chief among these examples are Asphyx (Droqen, circa 2012) and With Those We Love Alive (Porpentine, 2014), two games that incorporate player breathing into their mechanics, while forgoing any technical means of monitoring players’ respiration. In place of the usual command/output logic of human–machine interaction, these games map a more intimate alternative, in which players’ relationship to their avatars and in-game actions is built from a foundation of trust, shared truth, and consent between human bodies and software operations.

A Survey: Space Vector PWM (SVPWM) in 3φ Voltage Source Inverter (VSI)

Since last decades, the pulse width modulation (PWM) techniques have been an intensive research subject. Also, different kinds of methodologies have been presented on inverter switching losses, inverter output current/ voltage total harmonic distortion (THD), inverter maximum output of DC bus voltage. The Sinusoidal PWM is generally used to control the inverter output voltage and it helps to maintains drive performance. The recent years have seen digital modulation mechanisms based on theory of space vector i.e. Space vector PWM (SVPWM). The SVPWM mechanism offers the enhanced amplitude modulation indexes (MI) than sinusoidal PWM along with the reduction in the harmonics of inverter output voltage and reduced communication losses. Currently, the digital control mechanisms have got more attention than the analog counterparts, as the performance and reliability of microprocessors has increased. Most of the SVPWM mechanisms are performed by using the analog or digital circuits like microcontrollers and DSPs. From the recent study, analysis gives that use of Field Programmable Gate Arrays (FPGA) can offer more efficient and faster solutions. This paper discusses the numerous existing research aspects of FPGA realization for voltage source inverter (VSI) along with the future line of research.

The Role of Transfer in Designing Games and Simulations for Health: Systematic Review.

BackgroundThe usefulness and importance of serious games and simulations in learning and behavior change for health and health-related issues are widely recognized. Studies have addressed games and simulations as interventions, mostly in comparison with their analog counterparts. Numerous complex design choices have to be made with serious games and simulations for health, including choices that directly contribute to the effects of the intervention. One of these decisions is the way an intervention is expected to lead to desirable transfer effects. Most designs adopt a first-class transfer rationale, whereas the second class of transfer types seems a rarity in serious games and simulations for health.ObjectiveThis study sought to review the literature specifically on the second class of transfer types in the design of serious games and simulations. Focusing on game-like interventions for health and health care, this study aimed to (1) determine whether the second class of transfer is recognized as a road for transfer in game-like interventions, (2) review the application of the second class of transfer type in designing game-like interventions, and (3) assess studies that include second-class transfer types reporting transfer outcomes.MethodsA total of 6 Web-based databases were systematically searched by titles, abstracts, and keywords using the search strategy (video games OR game OR games OR gaming OR computer simulation*) AND (software design OR design) AND (fidelity OR fidelities OR transfer* OR behaviour OR behavior). The databases searched were identified as relevant to health, education, and social science.ResultsA total of 15 relevant studies were included, covering a range of game-like interventions, all more or less mentioning design parameters aimed at transfer. We found 9 studies where first-class transfer was part of the design of the intervention. In total, 8 studies dealt with transfer concepts and fidelity types in game-like intervention design in general; 3 studies dealt with the concept of second-class transfer types and reported effects, and 2 of those recognized transfer as a design parameter.ConclusionsIn studies on game-like interventions for health and health care, transfer is regarded as a desirable effect but not as a basic principle for design. None of the studies determined the second class of transfer or instances thereof, although in 3 cases a nonliteral transfer type was present.We also found that studies on game-like interventions for health do not elucidate design choices made and rarely provide design principles for future work. Games and simulations for health abundantly build upon the principles of first-class transfer, but the adoption of second-class transfer types proves scarce. It is likely to be worthwhile to explore the possibilities of second-class transfer types, as they may considerably influence educational objectives in terms of future serious game design for health.

A Review Paper on Copy Move Forgery Detection Techniques

Digital images are easy to manipulate and edit due to availability of powerful image processing and editing software. Nowadays, it is possible to add or remove important features from an image without leaving any obvious traces of tampering. As digital cameras and video cameras replace their analog counterparts, the need for authenticating digital images, validating their content and detecting forgeries will only increase. This paper reviews the detection techniques for copy move forgery tampering attacks. The copy-move attack in which a part of the image is copied and pasted somewhere else in the image with the intent to cover an important image feature is discussed in particular. It is done for hiding some image object, or adding more details resulting in atleast some part being cloned.

Simple realization of a third order Butterworth filter with MOS-only technique

Recently, many active filter circuits that use only MOS transistors were presented in the literature. In these circuits, instead of passive resistors, transconductances of MOSFETs operating in saturation region are used. Moreover, their parasitic gate to source capacitances are employed instead of passive capacitors. These circuits provide circuit implementation with fewer transistors and eliminate the need for external passive elements. In this study, a MOS-only third order Butterworth filter for high frequency applications has been proposed. The circuit leads to a compact circuit having fewer number of transistors compared to classical active block-based analog counterparts. Simulation results agree well with the theoretical study.