Three-state System Research Articles

Energy Efficiency and Renewable Energy Management with Multi-State Power-Down Systems

A power-down system has an on-state, an off-state, and a finite or infinite number of intermediate states. In the off-state, the system uses no energy and in the on-state energy it is used fully. Intermediate states consume only some fraction of energy but switching back to the on-state comes at a cost. Previous work has mainly focused on asymptotic results for systems with a large number of states. In contrast, the authors study problems with a few states as well as systems with one continuous state. Such systems play a role in energy-efficiency for information technology but are especially important in the management of renewable energy. The authors analyze power-down problems in the framework of online competitive analysis as to obtain performance guarantees in the absence of reliable forecasting. In a discrete case, the authors give detailed results for the case of three and five states, which corresponds to a system with on-off states and three additional intermediate states “power save”, “suspend”, and “hibernate”. The authors use a novel balancing technique to obtain optimally competitive solutions. With this, the authors show that the overall best competitive ratio for three-state systems is 9 5 and the authors obtain optimal ratios for various five state systems. For the continuous case, the authors develop various strategies, namely linear, optimal-following, progressive and exponential. The authors show that the best competitive strategies are those that follow the offline schedule in an accelerated manner. Strategy “progressive” consistently produces competitive ratios significantly better than 2.

In situ reversible color variation of a ready-made upconversion material using the designed component of a three-state fluorescence switching system.

In recent years, upconversion materials have attracted considerable attention because of their unique physicochemical features. Numerous studies have focused on the synthesis of upconversion materials with different colors. However, an easier way to vary the upconversion colors without changing the materials' components has not been extensively studied. In this study, we realized the in situ color variation of the designed upconversion material with the help of a three-state fluorescence switching hybrid device. The device was composed of Prussian blue and upconversion materials; the former element functioned as a fluorescence resonance energy transfer acceptor and the latter acted as a donor. Smartly applying the RGB color model guaranteed multicolor of the device. Moreover, the highest fluorescence contrast of the three-state fluorescence switching system was 86% (larger than the result of a previous study), and the three-state reversibility was remarkable; this was probably owing to the unique layer-by-layer dripping/electrodepositing assembly method. To the best of our knowledge, the in situ reversible color variation of the ready-made upconversion material has been demonstrated for the first time.

Effects of spectral diffusion on the nonlinear optical properties in two- and three-state quantum systems in a four-wave mixing signal

Effects of spectral diffusion on the third-order nonlinear susceptibility for two- and three-level quantum systems, immersed in a thermal reservoir, are evaluated with a four-wave mixing (FWM) signal through the density matrix formalism. For this, inhomogeneously broadened two- and three-level quantum systems are used. In these models, the distribution of natural frequencies follows a Lorentzian function. The absorptive and dispersive nonlinear optical responses are determined for the considered quantum models. The results presented in this work show potential applications in the development of optical switches and provide a potential method to measure spectral diffusion relaxation times in three-level quantum systems.

Tetrathiafulvalene (TTF)-Annulated Calix[4]pyrroles: Chemically Switchable Systems with Encodable Allosteric Recognition and Logic Gate Functions

Molecular and supramolecular systems capable of switching between two or more states as the result of an applied chemical stimulus are attracting ever-increasing attention. They have seen wide application in the development of functional materials including, but not limited to, molecular and supramolecular switches, chemosensors, electronics, optoelectronics, and logic gates. A wide range of chemical stimuli have been used to control the switching within bi- and multiple state systems made up from either singular molecular entities or supramolecular ensembles. In general, chemically triggered switching systems contain at least two major functional components that provide for molecular recognition and signal transduction, respectively. These components can be connected to one another via either covalent or noncovalent linkages. Of particular interest are switchable systems displaying cooperative or allosteric features. Such advanced control over function is ubiquitous in nature and, in the case of synthetic systems, may allow the capture and release of a targeted chemical entity or permit the transduction of binding information from one recognition site to another. Allosterically controlled complexation and decomplexation could also permit the amplification or deamplification of analyte-specific binding affinity, lead to nonlinear binding characteristics, or permit a magnification of output signals. Our own efforts to develop chemically driven supramolecular switches, advanced logic gates, and multifunction cascade systems have focused on the use of tetrathiafulvalene (TTF) annulated calix[4]pyrroles (C4Ps). These systems, TTF-C4Ps, combine several orthogonal binding motifs within what are conformationally switchable receptor frameworks. Their basic structure and host-guest recognition functions can be controlled via application of an appropriate chemical stimulus. Homotropic or heterotropic allosteric molecular recognition behavior is often seen. This has allowed us to (1) produce self-assembled structures, (2) control switching between bi- and multistate constructs, (3) generate chemical logic gates performing chemical-based Boolean logic operations, (4) create ionically controlled three-state logic systems that release different chemical messengers and activate disparate downstream reactions, and (5) encode a variety advanced functional operations into what are relatively simple molecular-scale devices. Looking to the future, we believe that exploiting allosteric control will expand opportunities for supramolecular chemists and allow some of the complexity seen in biology to be reproduced in simple constructs. Of particular appeal would be a capacity to release chemical messengers at will, perhaps after a prior capture and chemical modification step, that then encode for further downstream functions as seen in the case of the small molecules, such as neurotransmitters and pheromones, used by nature for the purpose of intraentity communication. Molecular scale logic devices with allosteric functions are thus the potential vanguard of a new area of study involving interactions between multiple discrete components with an emphasis on functional outcomes.

Multi-level maintenance strategy of deteriorating systems subject to two-stage inspection

Abstract Preventive maintenance, including time-based and condition-based maintenance, plays an important role in reducing system economic losses caused by unexpected failures. This paper studies a multi-level preventive maintenance strategy for a three-state industrial system subject to two competing failure processes. The first is a continuous degradation process characterized by the general path model, and the second is a shock process arriving according to a non-homogenous Poisson process. The degradation/hazard rate of the system undergoes an abrupt increase upon the initialization of the defective state, and the magnitude of the damage caused by a shock load is correlated to two factors: (a) operational age; (b) degradation speed. The system is preventively replaced at a pre-determined operational age, before which a finite number of inspections are executed according to a two-stage interval partition. The objective of this paper is to minimize the expected cost per unit time via the optimization of the replacement age, the control limit and two inspection intervals. A case study on a peristaltic pump is provided to illustrate the application of the maintenance model.

A Three-State System Based on Branched DNA Hybrids.

There is a need for materials that respond to chemical or physical stimuli through a change in their structure. While a transition between water-soluble form and solid is not uncommon for DNA-based structures, systems that transition between three different states at room temperature and ambient pressure are rare. Here we report the preparation of branched DNA hybrids with eight oligodeoxycytidylate arms via solution-phase, H-phosphonate-based synthesis. Some hybrids assemble into hydrogels upon lowering the pH, acting as efficient gelators at pH 4-6, but can also transition into a more condensed solid state form upon exposure to divalent cations. Together with the homogeneous solutions that the i-motif-forming compounds give at neutral pH, three-state systems result. Each state has its own color, if chromophores are included in the system. The assembly and gelation properties can be tuned by choosing the chain length of the arms. Their responsive properties make the dC-rich DNA hybrids candidates for smart material applications.

A three-state early warning system for the European Union

The global financial crisis of 2007-2008 focused the attention of financial authorities on developing methods to forecast and avoid future financial crises of similar magnitude. We contribute to the literature on crisis prediction in several important ways. First, we develop an early warning system (EWS) that provides 7-12 quarters advance warning with high accuracy in out-of-sample testing. Second, the EWS applies region-wide to the leading economies in the European Union. Third, the methodology is transparent – utilizing only publicly available macro-level data and standard statistical classification methodology (multinomial logistic regression, discriminant analysis, and neural networks). Fourth, we employ two relatively novel methodological innovations in EWS modeling: ternary state classification to guarantee a minimum advance warning period, and a fitting and evaluation criterion (the total harmonic mean) that prioritizes avoiding classification errors for the relatively infrequent events of most interest. As a consequence, a policymaker who uses these methods will enjoy a high probability that future crises will be signaled well in advance and that warnings of crisis will not be false alarms.

An Electronic Implementation of Lorenz Chaotic Oscillator Synchronization for Bistatic Radar Applications

The authors report the simulation and actual implementation of chaotic oscillator synchronization for a pair of three-state variable Lorenz systems. The first oscillator performs as a driver (transmitter), while the second system is made to respond the received waveform. Specifically, one of the state variables of the driver circuit is judiciously selected to generate an RF waveform. This waveform is transmitted through a noisy channel and is used to drive the response system until both the systems of all three state variables achieve complete replacement synchronization. It is known that this synchronization is sensitive to changes in received power. To overcome this, a technique hereon called generalized projective synchronization is employed to accept an attenuated version of the transmitted waveform. A sensitivity analysis reveals that generalized projective synchronization is robust with respect to deviations in the control parameter values of the response system due to tolerances of electronic components. The potential of the generalized projective synchronization is illustrated for a bistatic radar system case, where synchronization is necessary to obtain the range-Doppler information of a moving target. In this instance, the cross correlation, short-time cross-correlogram and cross ambiguity surface of the transmitted and synchronized waveforms are of high quality as indicated by their entropy measures.

Hierarchical perimeter control with guaranteed stability for dynamically coupled heterogeneous urban traffic

Perimeter control based on the Macroscopic Fundamental Diagram (MFD) is widely developed for alleviating or postponing congestion in a protected region. Recent studies reveal that traffic conditions might not be improved if the perimeter control strategies are applied to unstable systems where high demand generates heavy and heterogeneously distributed traffic congestion. Therefore, considering stability of the targeted traffic system is essential, for the sake of developing a feasible and then optimal control strategy. This paper sheds light on this direction. It integrates a stability characterization algorithm of MFD system equations into the Model Predictive Control (MPC) scheme, and features respectively an upper and a lower bound of the feasible control inputs, to guarantee system stability. Firstly, the dynamics of traffic heterogeneity and its effect on the MFD are analyzed, using real data from Guangzhou in China. Piecewise affine functions of average flow are proposed to capture traffic heterogeneity in both regional and subregional MFDs. Secondly, stability of a three-state two-region system is investigated via stable equilibrium and surface boundaries analysis. Finally, a three-layer hierarchical control strategy is introduced for the studied two-region heterogeneous urban networks. The first layer of the controller calculates the stable surface boundaries for the given traffic demands and then determines the bounds of control input (split rate). An MPC approach in the second layer is used to solve an optimization problem with two objectives of minimizing total network delay and maximizing network throughput. Heterogeneity among the subregions is minimized in the last layer by implementing simultaneously a subregional perimeter flow control and an internal flow control. The effectiveness and stability of the proposed control approach are verified by comparison with four existing perimeter control strategies.

Invariants-based shortcuts for fast generating Greenberger–Horne–Zeilinger state among three superconducting qubits**Project supported by the National Natural Science Foundation of China (Grant No. 11464046).

As one of the most promising candidates for implementing quantum computers, superconducting qubits (SQs) are adopted for fast generating the Greenberger–Horne–Zeilinger (GHZ) state by using invariants-based shortcuts. Three SQs are separated and connected by two coplanar waveguide resonators (CPWRs) capacitively. The complicated system is skillfully simplified to a three-state system, and a GHZ state among three SQs is fast generated with a very high fidelity and simple driving pulses. Numerical simulations indicate the scheme is insensitive to parameter deviations. Besides, the robustness of the scheme against decoherence is discussed in detail.

Controlling vibrational population distribution of the Na2 molecule by ultrashort pulses in the three-state system

The population transfer and vibrational population distribution of the target state in the three-state Na2 molecule are theoretically investigated by using the time-dependent wave packet method. The population can be efficiently transferred to the target state by the process of adiabatic passage by light induced potentials (APLIP). The vibrational population distribution of the target state can be controlled by adjusting the laser parameters, such as the pulse width, time delay, intensity and envelope. The calculations show the vibrational population distribution variations under different laser parameters where the preparation of the specific state for molecules can be rationalised. In addition, the influence of the ionization state on the population transfer is studied.

Distributed Economic MPC With Separable Control Contraction Metrics

In this letter, a flexible and scalable distributed economic model predictive control scheme is proposed for large-scale networked systems consisting of nodes with local self-interest economic objectives but a shared responsibility for stability of the interconnected network. In this letter, subsystems are controlled to track reference trajectories while optimizing their own economic costs during the transitions. A reference-independent stability constraint is introduced using a sum-separable control contraction metric. The proposed control design approach is thereby independent of both reference trajectories and the economic cost functions and as such suitable for flexible manufacturing. We observe that self-interested distributed optimization with shared responsibility for stability results in the same general problem formulation as network utility maximization, and make use of the alternating direction method of multipliers to coordinate the optimization. The proposed approach is illustrated with an example of distributed control of a network with 120 nodes, each of which is a three-state nonlinear system.

Thermodynamic cost of external control

Artificial molecular machines are often driven by the periodic variation of an external parameter. This external control exerts work on the system of which a part can be extracted as output if the system runs against an applied load. Usually, the thermodynamic cost of the process that generates the external control is ignored. Here, we derive a refined second law for such small machines that include this cost, which is, for example, generated by free energy consumption of a chemical reaction that modifies the energy landscape for such a machine. In the limit of irreversible control, this refined second law becomes the standard one. Beyond this ideal limiting case, our analysis shows that due to a new entropic term unexpected regimes can occur: the control work can be smaller than the extracted work and the work required to generate the control can be smaller than this control work. Our general inequalities are illustrated by a paradigmatic three-state system.

Fast generating W state of three superconducting qubits via Lewis–Riesenfeld invariants**Project supported by the National Natural Science Foundation of China (Grant No. 11464046).

We propose a scheme for a fast generating three-qubit W state in a superconducting system by using a technique of shortcuts to adiabaticity, Lewis–Riesenfeld invariants. Three identical superconducting qubits (SQs) are connected by two coplanar waveguide resonators (CPWRs) capacitively. Under a certain limit condition, we convert the complicated SQ system into a simple three-state system. By designing experimentally accessible harmonic pulses, a three-SQ W state is implemented with quite short operation time and high fidelity. Numerical simulations prove that the scheme is robust against the parameter deviation. In addition, we also give detailed discussion about the scheme robustness against decoherence.

A condition-based maintenance model for a three-state system subject to degradation and environmental shocks

Condition-based maintenance (CBM) is a key measure in preventing unexpected failures caused by internal-based deterioration and external environmental shocks. This study proposes a condition-based maintenance policy for a single-unit system with two competing failure modes, i.e., degradation-based failure and shock-based failure. The failure process of the system is divided into three states, namely, normal, defective and failed, and a defective state incurs a greater degradation rate than a normal state. Random shocks arrive according to a non-homogenous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence of external shocks will be affected to the degradation level of the system. Periodic inspections are performed to measure the state and the degradation level of the system, and two preventive degradation thresholds are scheduled depending on the system state. The expected cost per unit time is derived through the joint optimization of the two preventive thresholds as well as the periodic inspection interval. A numerical example is proposed to illustrate the maintenance model.

Arbitrary quantum state engineering in three-state systems via Counterdiabatic driving.

A scheme for arbitrary quantum state engineering (QSE) in three-state systems is proposed. Firstly, starting from a set of complete orthogonal time-dependent basis with undetermined coefficients, a time-dependent Hamiltonian is derived via Counterdiabatic driving for the purpose of guiding the system to attain an arbitrary target state at a predefined time. Then, on request of the assumed target states, two single-mode driving protocols and a multi-mode driving protocol are proposed as examples to discuss the validity of the QSE scheme. The result of comparison between single-mode driving and multi-mode driving shows that multi-mode driving seems to have a wider rang of application prospect because it can drive the system to an arbitrary target state from an arbitrary initial state also at a predefined time even without the use of microwave fields for the transition between the two ground states. Moreover, for the purpose of discussion in the scheme’s feasibility in practice, a polynomial ansatz as the simplest exampleis used to fix the pulses. The result shows that the pulses designed to implement the protocols are not hard to be realized in practice. At the end, QSE in higher-dimensional systems is also discussed in brief as a generalization example of the scheme.

Coherence-Controlled Nonadiabatic Dynamics via State-Space Decomposition: A Consistent Way To Incorporate Ehrenfest and Born-Oppenheimer-Like Treatments of Nuclear Motion.

Accurately describing nuclear motion is crucial in electronically nonadiabatic dynamics simulations. In this work, a coherence-controlled (CC) approach is proposed based on the mapping between the classical state space and the full electronic matrix and that between the decomposed state space and different nuclear dynamics that allows nuclear motion to properly follow either Ehrenfest dynamics in the coherence domain or Born-Oppenheimer-like dynamics in the single-state domain in a consistent manner. This new method is applied to several benchmark models involving nonadiabatic transitions in two-state or three-state systems, and the obtained results are in excellent agreement with exact quantum calculations. As a generalization of the recently developed symmetrical quasiclassical approach and the augmented image (AI) version of the multistate trajectory approach, the proposed method is extremely efficient and numerically stable. Therefore, it has great potential for implementation in nonadiabatic molecular dynamics simulations for realistic complex systems, such as materials and biological molecules.

Selective excitation in a three-state system using a hybrid adiabatic-nonadiabatic interaction

The chirped-pulse interaction in the adiabatic coupling regime induces cyclic permutations of the energy states of a three-level system in the $V$-type configuration, which process is known as the three-level chirped rapid adiabatic passage. Here we show that a spectral hole in a chirped pulse can turn on and off one of the two adiabatic crossing points of this process, reducing the system to an effective two-level system. The given hybrid adiabatic-nonadiabatic transition results in selective excitation of the three-level system, controlled by the laser intensity and spectral position of the hole as well as the sign of the chirp parameter. Experiments are performed with shaped femtosecond laser pulses and the three lowest energy-levels (5S$_{1/2}$, 5P$_{1/2}$, and 5P$_{3/2}$) of atomic rubidium ($^{85}$Rb), of which the result shows good agreement with the theoretically analyzed dynamics. The result indicates that our method, being combined with the ordinary chirped-RAP, implements an adiabatic transitions between the two excited states. Furthermore the laser intensity-dependent control may have applications including selective excitations of atoms or ions arranged in space when being used in conjunction with laser beam profile programming.

Availability analysis of a LNG processing plant using the Markov process

Purpose – The purpose of this paper is to propose a state dependent stochastic Markov model for availability analysis of process plant instead of traditional time dependent model. Design/methodology/approach – The traditional concepts of system performance measurement and reliability (namely, binary; two-state concepts) are observed to be inadequate to characterize performance of complex system components. Availability analysis considering an intermediate state, such as a degraded state, provides a better alternative mechanism for system performance mapping. The availability model provides a better assessment of failure and repair characteristics for equipment in the sub-system and its overall performance. In addition to availability analysis, this paper also discusses the preventive maintenance (PM) program to achieve target availability. In this model, the degraded state is considered as a PM state. Using Markov analysis the optimum maintenance interval is determined. Findings – Markov process provides an easier way to measure the performance of the process facility. This study also revealed that the maintenance interval has a major influence in the availability of a process facility as well as in maintaining target availability. The developed model is also applicable to the varying target availability as well as having the capability to handle even the reconfigured process systems. Research limitations/implications – Considering the degraded state as an operative state, a higher availability of the plant is predicted. The consideration of the degraded state of the system makes the availability estimation more realistic and acceptable. Availability quantification, target availability allocation and a PM model are exemplified in a sub-system of an liquefied natural gas facility. Originality/value – The unique features of the present study are; Markov modeling approach integrating availability and PM; optimum PM interval determination of stochastically degrading components based on target availability; consideration of three-state systems; and consideration of increasing failure rates.

Adiabatic following for a three-state quantum system

Adiabatic time-evolution – found in various forms of adiabatic following and adiabatic passage – is often advantageous for controlled manipulation of quantum systems due to its insensitivity to deviations in the pulse shapes and timings. In this paper we discuss controlled adiabatic evolution of a three-state quantum system, a natural advance to the widespread use of two-state systems in numerous contemporary applications. We discuss, and illustrate, not only possibilities for population transfer but also for creating, with prescribed relative phase, 50:50 superpositions of two Zeeman sublevels in a letter-vee coupling linkage.