Robust Realization Research Articles

A Machine Learning Perspective on Personalized Medicine: An Automized, Comprehensive Knowledge Base with Ontology for Pattern Recognition

Personalized or precision medicine is a new paradigm that holds great promise for individualized patient diagnosis, treatment, and care. However, personalized medicine has only been described on an informal level rather than through rigorous practical guidelines and statistical protocols that would allow its robust practical realization for implementation in day-to-day clinical practice. In this paper, we discuss three key factors, which we consider dimensions that effect the experimental design for personalized medicine: (I) phenotype categories; (II) population size; and (III) statistical analysis. This formalization allows us to define personalized medicine from a machine learning perspective, as an automized, comprehensive knowledge base with an ontology that performs pattern recognition of patient profiles.

An ultra-broadband single-component fractional-order capacitor using MoS2-ferroelectric polymer composite

The phase angle of a fractional-order capacitor's (FOC) impedance has a constant value between −90° and 0°. Maintaining this value over a broad frequency band is of utmost importance since it increases the applicability of the electrical circuit that employs the fractional-order capacitor (FOC). In this work, a molybdenum disulfide (MoS2)-ferroelectric polymer composite is used to design/fabricate an FOC. The resulting FOC's bandwidth of operation, which is defined as the frequency band where the variation in the phase angle is no more than ±4°, is five decades between 100 Hz and 10 MHz, a 3 decades improvement over the best reported state of the art. The value of the constant phase angle can be tuned from −80° to −58° by changing the type of the ferroelectric polymer in the composite and the volume ratio of MoS2. The results presented in this work demonstrate the potential of the FOCs fabricated using MoS2-ferroelectric polymer composites in robust and accurate realization of various electrical systems.

Experimental Demonstration of Multi Moiré Structured Illumination Microscopy

Structured illumination microscopy (SIM) improves spatial resolution by folding high-frequency spectral components into the optical system’s passband. While linear SIM is superior in terms of temporal resolution, living-cells imaging compatibility, and overall optical setup simplicity relative to other super-resolution techniques, it is, however, inferior when it comes to spatial resolution enhancement capability. In this letter, we present experimental demonstration of a novel Multi Moire SIM (MM-SIM) scheme achieving improved lateral resolution enhancement while preserving the inherent advantages of linear SIM. Using MM-SIM, an approximately 4-fold lateral resolution enhancement was achieved, effectively increasing the optical system’s NA from 0.4 to 1.6. The MM-SIM scheme is a simple and robust realization of 4-fold resolution enhancement capable of unleashing the full potential of standing-wave total internal reflection fluorescence structured illumination microscopy (TIRF-SIM) while preserving the in...

Performance of Mode Space Detector in Uncertain Shallow Water and Its Robust Realization

The statistics of the mode space detector (MSD) whose modes are characterized by some degree of mismatch to truth [that is, the mismatched mode space detector (MMSD)] are derived. As a measure of the “containing relation” between the mode spaces derived from different environmental realizations we propose the relative projection error metric, through which the performance of the MMSD can be further investigated and compared to the MSD using accurate environmental knowledge. From this performance analysis, we suggest that by simply using the greatest dimensional physically supported mode space, we can obtain a robust MSD. It can achieve the same performance robustness as the energy detector—the performance is only determined by the array signal energy and is insensitive to the specific source position and environmental conditions. It can also avoid the potentially-significant performance degradation of the Bayesian detector when applied to certain deterministic scenarios at a cost of small average performance degradation. Numerical simulations in a typical uncertain shallow-water environment support our assertions.

Coupled-resonator-induced plasmonic bandgaps.

By drawing an analogy with the conventional photonic crystals, the plasmonic bandgaps have mainly employed the periodic metallic structures, named as plasmonic crystals. However, the sizes of the plasmonic crystals are much larger than the wavelengths, and the large sizes considerably decrease the density of the photonic integration circuits. Here, based on the coupled-resonator effect, the plasmonic bandgaps are experimentally realized in the subwavelength waveguide-resonator structure, which considerably decreases the structure size to subwavelength scales. An analytic model and the phase analysis are established to explain this phenomenon. Both the experiment and simulation show that the plasmonic bandgap structure has large fabrication tolerances (>20%). Instead of the periodic metallic structures in the bulky plasmonic crystals, the utilization of the subwavelength plasmonic waveguide-resonator structure not only significantly shrinks the bandgap structure to be about λ2/13, but also expands the physics of the plasmonic bandgaps. The subwavelength dimension, together with the waveguide configuration and robust realization, makes the bandgap structure easy to be highly integrated on chips.

Rigorous time-domain analysis of statistically oriented graphene sheet fluctuations

PurposeImportant statistical variations are likely to appear in the propagation of surface plasmon polariton waves atop the surface of graphene sheets, degrading the expected performance of real-life THz applications. This paper aims to introduce an efficient numerical algorithm that is able to accurately and rapidly predict the influence of material-based uncertainties for diverse graphene configurations.Design/methodology/approachInitially, the surface conductivity of graphene is described at the far infrared spectrum and the uncertainties of its main parameters, namely, the chemical potential and the relaxation time, on the propagation properties of the surface waves are investigated, unveiling a considerable impact. Furthermore, the demanding two-dimensional material is numerically modeled as a surface boundary through a frequency-dependent finite-difference time-domain scheme, while a robust stochastic realization is accordingly developed.FindingsThe mean value and standard deviation of the propagating surface waves are extracted through a single-pass simulation in contrast to the laborious Monte Carlo technique, proving the accomplished high efficiency. Moreover, numerical results, including graphene’s surface current density and electric field distribution, indicate the notable precision, stability and convergence of the new graphene-based stochastic time-domain method in terms of the mean value and the order of magnitude of the standard deviation.Originality/valueThe combined uncertainties of the main parameters in graphene layers are modeled through a high-performance stochastic numerical algorithm, based on the finite-difference time-domain method. The significant accuracy of the numerical results, compared to the cumbersome Monte Carlo analysis, renders the featured technique a flexible computational tool that is able to enhance the design of graphene THz devices due to the uncertainty prediction.

Realization of New Robust Digital Fractional-order Compensators

The efficient and robust realization of fractional-order compensators is fundamental for digital control applications. The main task is to approximate these devices with an efficiently computed rational transfer function with limited negative effects due to quantization and other implementation issues. This paper proposes new closed-form expressions to easily determine the coefficients of the discrete transfer functions. Moreover, a realization with low sensitivity is obtained by the serial structure of a multiple compensator that employs adjacent, shifted sections, each dominating on a different frequency interval and contributing to a flat Bode phase diagram. The achieved features are useful for designing robust controllers.

Model Hamiltonian and time reversal breaking topological phases of antiferromagnetic half-Heusler materials

In this work, we construct a generalized Kane model with a new coupling term between itinerant electron spins and local magnetic moments of anti-ferromagnetic ordering in order to describe the low energy effective physics in a large family of anti-ferromagnetic half-Heusler materials. Topological properties of this generalized Kane model is studied and a large variety of topological phases, including Dirac semimetal phase, Weyl semimetal phase, nodal line semimetal phase, type-B triple point semimetal phase, topological mirror (or glide) insulating phase and anti-ferromagnetic topological insulating phase, are identified in different parameter regions of our effective models. In particular, we find that the system is always driven into the anti-ferromagnetic topological insulator phase once a bulk band gap is open, irrespective of the magnetic moment direction, thus providing a robust realization of anti-ferromagentic topological insulators. Furthermore, we discuss the possible realization of these topological phases in realistic anti-ferromagnetic half-Heusler materials. Our effective model provides a basis for the future study of physical phenomena in this class of materials.

Protected ultrastrong coupling regime of the two-photon quantum Rabi model with trapped ions

We propose a robust realization of the two-photon quantum Rabi model in a trapped-ion setting based on a continuous dynamical decoupling scheme. In this manner the magnetic dephasing noise, which is identified as the main obstacle to achieve long time coherent dynamics in ion-trap simulators, can be safely eliminated. More specifically, we investigate the ultrastrong coupling regime of the two-photon quantum Rabi model whose realization in trapped ions involves second-order sideband processes. Hence, the resulting dynamics becomes unavoidably slow and more exposed to magnetic noise requiring an appropriate scheme for its elimination. Furthermore, we discuss how dynamical decoupling methods take a dual role in our protocol, namely they remove the main source of decoherence from the dynamics while actively define the parameter regime of the simulated model.

On the dialectal variations of voiced sibilant /dz/ in Taiwan Min young speakers

This study examined the realization of /dz/ in three dialects of Taiwan Min among young speakers based on a paragraph-reading task. Results showed there were five robust realization categories of /dz/, including the commonly reported dental sibilants, velar obstruents, and liquids and the rarely mentioned dental nonsibilants and retroflexes. Liquids and retroflexes were more likely to occur before a rounded segment, while dental sibilants, dental nonsibilants, and velar obstruents were more likely to occur before an unrounded segment. For the latter environment, there was also a correlation between structural complexity and realization of dental sibilants, velar obstruents, and liquids. The three dialects examined demonstrated different attitudes towards the realization of /dz/. 泉 Chôan was the most receptive to the new sounds of liquids, dental nonsibilants, and retroflexes, while Mix was the most conservative in preserving the old forms of dental sibilants and velar obstruents. 漳 Chiang was somewhere in between. It maintained a robust dental sibilant category like Mix yet welcomed new variants of dental nonsibilants and retroflexes like Chôan. Talkers were consistent in their /dz/ realization choices and intra-talker variability was low. This study thus demonstrated that talkers’ realization of a variable sound is a complex product of linguistic structure, speakers’ background, and idiosyncratic preference.

Parametric Symmetry Breaking in a Nonlinear Resonator.

Much of the physical world around us can be described in terms of harmonic oscillators in thermodynamic equilibrium. At the same time, the far-from-equilibrium behavior of oscillators is important in many aspects of modern physics. Here, we investigate a resonating system subject to a fundamental interplay between intrinsic nonlinearities and a combination of several driving forces. We have constructed a controllable and robust realization of such a system using a macroscopic doubly clamped string. We experimentally observe a hitherto unseen double hysteresis in both the amplitude and the phase of the resonator's response function and present a theoretical model that is in excellent agreement with the experiment. Our work unveils that the double hysteresis is a manifestation of an out-of-equilibrium symmetry breaking between parametric phase states. Such a fundamental phenomenon, in the most ubiquitous building block of nature, paves the way for the investigation of new dynamical phases of matter in parametrically driven many-body systems and motivates applications ranging from ultrasensitive force detection to low-energy computing memory units.

Fast and Reliable Method of SearchingPower System Marginal States

In order to maintain power system security at the appropriate level and low cost, it is essential to accurately assess steady-state stability limits and power flow feasibility boundaries, i.e., power system marginal states (MS). This paper is devoted to a robust realization of the MS model based on nonlinear programming in a given direction of power change. Considering peculiar properties of this model has allowed proposing a simple, robust and computationally efficient method of the MS search that uses only standard blocks of the load flow solution and can be easily realized in the existing load flow programs. The technique developed on this basis allows considering errors of power change forecast quite easily. Tests on IEEE and Russian systems showed effectiveness of the proposed methods.

Two time-scale observer-based robust motion controller design and realization of a linear actuator

In this paper, an observer-based sliding mode controller is proposed for a high-accuracy motion plant to suppress the disturbances and improve the tracking performance. In particular, a two time-scale separation technology, which can recover the disturbance state in a faster time scale, is utilized to compensate the disturbances and improve the system robustness. The parameter identification is carried out to obtain the model coefficients with a high fitting rate. Such an identified model can allow the engineers to tune the controller’s gains highly enough when the system suffers from the measurement noises. Instead of the traditional low-pass filter, a differentiator is introduced for the velocity signal prediction and its discrete-time version is provided to attenuate the noises effect. To verify the effectiveness of the proposed approach, an adaptive robust control law is compared with the proposed one in terms of dynamic positioning error, robustness and rapid signal tracking, and the superiority and advantages can be illustrated by the experimental results.

Model Driven Manufacturing Process Design and Managing Quality

Besides decisions in design, decisions made in process planning determine the conditions for manufacturing the right quality. Hence systematic process planning is a key enabler for robust product realization from design through manufacturing. Current work methods for process planning and quality assurance lack efficient system integration. As a consequence companies spend unnecessary lot of non-value adding time on managing quality. This paper presents a novel model-based approach to integrate process planning and quality assurance. The presented model enables a more efficient and holistic way for managing quality from design to manufacturing. New possibilities to communicate process design intent and present important quality assurance information in a more structured and comprehensive way is also enabled.

Induced topological phases at the boundary of 3D topological superconductors.

We present tight-binding models of 3D topological superconductors in class DIII that support a variety of winding numbers. We show that gapless Majorana surface states emerge at their boundary in agreement with the bulk-boundary correspondence. At the presence of a Zeeman field, the surface states become gapped and the boundary behaves as a 2D superconductor in class D. Importantly, the 2D and 3D winding numbers are in agreement, signifying that the topological phase of the boundary is induced by the phase of the 3D bulk. Hence, the boundary of a 3D topological superconductor in class DIII can be used for the robust realization of localized Majorana zero modes.

Model-driven Process Planning and Quality Assurance

Systematic process planning is a key enabler for robust product realization from design through manufacturing. Every process and operation must be designed in the best possible way to ensure that the overall process chain leads to the right product quality. During the last two decades a shift from inspection of manufactured products to a more holistic approach with quality assurance as an integrated activity throughout the product realization process has emerged in manufacturing industry. The importance of the principles addressed in the methods and tools used in automotive industry for quality management is indisputable. However, the tasks of creating and managing documents for Process Failure Mode and Effect Analysis (PFMEA), Control plans, Initial process studies and Measurement System Analysis (MSA) results in high workload. Also, lack of interoperability between different computer applications used in process planning and quality assurance results in information fragmentation, data duplication and potential data inconsistency. This paper proposes a novel, model driven approach for process planning integrating quality assurance which emphasizes the application of digital models to create, represent and use information of products, processes and resources. By reducing the amount of data and document duplication, the presented model driven approach has potential to radically increase the direct value adding part of manufacturing engineer's daily work also contributing to achieve a more holistic view in interdisciplinary work between different experts in product realization.

Sustained large-amplitude chemomechanical oscillations induced by the Landolt clock reaction.

Synergetic chemomechanical oscillators represent a fundamentally new class of oscillators, where a clock reaction, owning no oscillatory chemical kinetics, generates shrinking-swelling cycles in a chemoresponsive gel under appropriate fixed nonequilibrium boundary conditions. Sufficiently large size-changes are a condition for continually switching between a reacted and an unreacted chemical state in the gel through sufficiently large differences in the diffusion time between the environment and the core of the gel. Two former experimental demonstrations with acid autocatalytic reactions were frustrated either by complex behaviors (chlorite-tetrathionate system) or by side reactions with the gel matrix (bromate-sulfite system). With the Landolt (iodate-sulfite) reaction, regular large-amplitude chemomechanical oscillations can be sustained for more than a week. This enabled a fine study of the temperature and stoichiometry range of operation. I have identified several key steps that are experimentally essential to the systematic design of further synergetic oscillators. The robust realization of this type of self-organization in artificial systems is currently unique.

Study on the Control of Fuzzy Sliding Mode Variable Structure of Aerospace Vehicle’s Attitude

Based on the nonlinear, strongly coupled and uncertain model of the aerocraft vehicles attitude system, a fuzzy variable structure control method is proposed. Based on the feedback-linearization technique, the system was firstly decoupled into three independent SISO subsystems, and then controllers for each subsystem were designed. Modeling error and unknown disturbance is effectively restrained with the proposed adaptive fuzzy control with variable structure control. Theoretical analysis and simulation results show that the proposed method has high control accuracy, high robust and easy realization.

High-speed monodisperse droplet generation by ultrasonically controlled micro-jet breakup

A liquid jet that is ejected from a nozzle into air will disintegrate into drops via the well-known Plateau–Rayleigh instability within a certain range of Ohnesorge and Reynolds numbers. With the focus on the micrometer scale, we investigate the control of this process by superimposing a suitable ultrasonic signal, which causes the jet to break up into a very precise train of monodisperse droplets. The jet leaves a pressurized container of liquid via a small orifice of about 20 μm diameter. The break-up process and the emerging droplets are recorded via high-speed imaging. An extended parameter study of exit speed and ultrasonic frequency is carried out for deionized water to evaluate the jet’s state and the subsequent generation of monodisperse droplets. Maximum exit velocities obtained reach almost 120 m s−1, and frequencies have been applied up to 1.8 MHz. Functionality of the method is confirmed for five additional liquids for moderate jet velocities \(\lesssim\)38 m s−1. For the uncontrolled jet disintegration, the drop size spectra revealed broad distributions and downstream drop growth by collision, while the acoustic control generated monodisperse droplets with a standard deviation less than 0.5 %. By adjustment of the acoustic excitation frequency, drop diameters could be tuned continuously from about 30 to 50 μm for all exit speeds. Good agreement to former experiments and theoretical approaches is found for the relation of overpressure and jet exit speed, and for the observed stability regions of monodisperse droplet generation in the parameter plane of jet speed and acoustic excitation frequency. Fitting of two free parameters of the general theory to the liquids and nozzles used is found to yield an even higher precision. Furthermore, the high-velocity instability limit of regular jet breakup described by von Ohnesorge has been superseded by more than a factor of two without entering the wind-induced instability regime, and monodisperse droplet generation was always achievable. Thus, the reliable and robust realization of tunable high-speed monodisperse micro-droplet trains is demonstrated. Some implication for applications is discussed.

Polycrystalline silicon ring resonator photodiodes in a bulk complementary metal-oxide-semiconductor process

We present measurements on resonant photodetectors utilizing sub-bandgap absorption in polycrystalline silicon ring resonators, in which light is localized in the intrinsic region of a p+/p/i/n/n+ diode. The devices, operating both at λ=1280 and λ=1550 nm and fabricated in a complementary metal-oxide-semiconductor (CMOS) dynamic random-access memory emulation process, exhibit detection quantum efficiencies around 20% and few-gigahertz response bandwidths. We observe this performance at low reverse biases in the range of a few volts and in devices with dark currents below 50 pA at 10 V. These results demonstrate that such photodetector behavior, previously reported by Preston et al. [Opt. Lett. 36, 52 (2011)], is achievable in bulk CMOS processes, with significant improvements with respect to the previous work in quantum efficiency, dark current, linearity, bandwidth, and operating bias due to additional midlevel doping implants and different material deposition. The present work thus offers a robust realization of a fully CMOS-fabricated all-silicon photodetector functional across a wide wavelength range.