This article presents the design, identification, and control of a nano-positioning device suited to image biological samples as part an atomic force microscope. The is actuated by piezoelectric stack its motion sensed linear variable differential transformer. It demonstrated that conventional proportional-integral architecture does not meet bandwidth requirements for positioning. design implementation H∞ controller demonstrates substantial improvements in positioning speed precision, while...

In this paper we analyze the controllability of quantum systems arising in molecular dynamics. We model these as with finite numbers levels, and examine their controllability. To do pass to unitary generators use results on invariant Lie groups. Examples systems, modeled finite-dimensional control are provided. A simple algorithm detect a system is Finally, apply five-level system.

In this paper, the design of controllers that incorporate structural and multiobjective performance requirements is considered. The control structures under study cover nested, chained, hierarchical, delayed interaction communications, symmetric systems. Such are strongly related to several modern-day future applications including integrated flight propulsion systems, platoons vehicles, micro-electro-mechanical networked control, networks, production lines chemical processes. It shown system...

Determining interrelatedness structure of various entities from multiple time series data is significant interest to many areas. Knowledge such a can aid in identifying cause and effect relationships, clustering similar entities, identification representative elements model reduction. The majority existing results are based on correlation indices which effectively assume static relationship between the not suitable for detecting when dynamically related or involve loops. In this paper,...

A multi-mode analysis of micro-cantilever dynamics is presented. We derive the power spectral density cantilever displacement due to a thermal noise source and predict cantilevers’s fundamental resonant frequency higher harmonics. The first mode in model equivalent traditional single-mode model. Experimental results obtained with silicon nitride at 300 K are excellent qualitative agreement may be used obtain accurate values properties such as elastic modulus, effective mass, thickness moment inertia.

This paper presents a distributed, robust, and optimal control architecture for network of multiple dc-dc converters. The converters considered form dc microgrid in order to regulate desired bus voltage meet prescribed time-varying power sharing criteria among different energy sources. Such coordinated microgrids provide an important framework leveraging the benefits distributed generation consumption. proposed design seamlessly accommodates communication architectures that range from...

Several methods have been developed for joint working and spare capacity planning in survivable wavelength-division-multiplexing (WDM) networks. These considered a static traffic demand optimized the network cost assuming various models survivability paradigms. Our interest primarily lies operation under dynamic traffic. We formulate operational phases WDM networks as single integer linear programming (ILP) optimization problem. This common framework avoids service disruption to existing...

The atomic force microscope (AFM) is a powerful tool for investigating surfaces at scales. Harmonic balance and power techniques are introduced to analyze the tapping-mode dynamics of microscope. harmonic perspective explains observations hitherto unexplained in AFM literature. A nonconservative model cantilever–sample interaction developed. energy dissipation sample studied resulting equations combined with used estimate parameters. Experimental results confirm that tools can be effectively...

Graphical models is a succinct way to represent the structure of probability distributions. This article analyzes graphical model nodal voltages in non-radial power distribution grids. Using algebraic and structural properties models, algorithms exactly determining topology detecting line changes for grids are presented along with their theoretical limitations. We show that if have cycles/loops size greater than three, then sufficient efficient estimation without additional assumptions on...

This article reports an algorithm for multi-agent distributed optimization problems with a common decision variable, local linear equality and inequality constraints set convergence rate guarantees. \textcolor{black}{The accrues all the benefits of Alternating Direction Method Multipliers (ADMM) approach}. It also overcomes limitations existing methods on convex inequality, by allowing directed communication topologies. Moreover, can be synthesized distributively. The developed has: (i)...

This paper presents the identification and control of piezoelectric positioners used in atomic force microscopes (AFM) with goal improving probe positioning on sample surface. A novel sensor was developed for this task employed to infer a sixth order linear two input output model piezo's lateral dynamics. The piezo design controller tracking reference signals common AFM operation. were shown significantly improve microscope's ability position sample's surface, enabling user precisely scan...

The paper tackles the problem of identifying an individual transfer function in a network linear dynamical systems presence loops under assumptions that (i) only subset nodes is observable, and (ii) data are being passively recorded (i.e. it not possible to intervene on any part system by actively injecting input). Such scenario often encountered study many naturally occurring also motivated operating networked where injection external signal might lead undesired disruptions. Sufficient...

Network systems have become a ubiquitous modeling tool in many areas of science where nodes graph represent distributed processes and edges between form dynamic coupling. When network topology is already known (or partially known), two associated goals are, to derive estimators for the network, which cannot be directly observed or are impractical measure; quantitatively identify relations nodes. We address both problems challenging scenario only some outputs being measured inputs not...

In typical dynamic mode operation of atomic force microscopes, steady state signals like amplitude and phase are used for detection imaging material. these methods, the resolution bandwidth dictated by quality factor (Q) cantilever. this letter, we present a methodology that exploits deflection signal during transient cantilever motion. The principle overcomes fundamental limitations on trade off between in existing methods makes it independent factor. Experimental results provided...

Seamless recovery of power to critical infrastructures, after grid failure, is a crucial need arising in scenarios that are increasingly becoming more frequent. In this article, we propose seamless transition strategy using single and unified mode-dependent droop-controlled grid-forming inverters. The control achieves the following objectives: First, regulates output active reactive by inverters desired value while operating on-grid mode; second, injections into load failure operates mode...

In this article tapping-mode atomic force microscope dynamics is studied. The existence of a periodic orbit at the forcing frequency shown under unrestrictive conditions. further analyzed using impact model for tip-sample interaction and spring-mass-damper cantilever. Stability established. Closed-form expressions various variables important in imaging are obtained. linear relationship amplitude sine phase first harmonic with respect to cantilever-sample offset shown. study reinforces...

The paper deals with the problem of unveiling link structure a network linear dynamical systems. A technique is provided guaranteeing an exact detection links systems no undirected cycles (Linear Dynamic Polytrees). In particular, presence unobserved (latent) nodes taken into account. Knowledge on specific number hidden processes not required. It proven that topology can be consistently reconstructed, as long degree each latent node at least three outdegree two. result extends previous work...

In this article we present a method to reconstruct the interconnectedness of dynamically related stochastic processes, where interactions are bi-directional and underlying topology is tree. Our approach based on multivariate Wiener filtering which recovers spurious edges apart from true in reconstruction. The main contribution work show that all links obtained using can be eliminated if tree three stage network reconstruction procedure for trees. We illustrate effectiveness developed by...

Abstract In the existing dynamic‐mode operation of atomic force microscopes (AFMs) steady‐state signals like amplitude and phase are used for detection imaging material. Due to high quality factor cantilever probe corresponding methods inherently slow. this paper, a novel methodology fast interrogation material that exploits transient part motion is developed. This method effectively addresses perceived fundamental limitation on bandwidth due factors. It particularly suited small time scale...

In this article, we develop a novel approach to design power hardware-in-the-loop (PHIL) simulation interfaces that maximize bandwidth and accuracy by leveraging modern control framework explicitly considers objectives on can automatically synthesize an optimal controller meets these while stabilizing the closed-loop system. The method developed improves upon common approaches PHIL interface typically involve multiple steps for manual compensation stabilization result in are stable but have...