Multi-state Characteristics Research Articles

Real-Time Corrected Traffic Correlation Model for Traffic Flow Forecasting

This paper focuses on the problems of short-term traffic flow forecasting. The main goal is to put forward traffic correlation model and real-time correction algorithm for traffic flow forecasting. Traffic correlation model is established based on the temporal-spatial-historical correlation characteristic of traffic big data. In order to simplify the traffic correlation model, this paper presents correction coefficients optimization algorithm. Considering multistate characteristic of traffic big data, a dynamic part is added to traffic correlation model. Real-time correction algorithm based on Fuzzy Neural Network is presented to overcome the nonlinear mapping problems. A case study based on a real-world road network in Beijing, China, is implemented to test the efficiency and applicability of the proposed modeling methods.

A multi-stable energy harvester: Dynamic modeling and bifurcation analysis

A theoretical investigation is conducted on the dynamic and energetic characteristics of a multi-stable bimorph cantilever energy harvester that uses magnetic attraction effect. The multi-stable energy harvester under study is composed of a bimorph cantilever beam with soft magnetic tip and two externally fixed permanent magnets that are arranged in series. With this configuration, the magnetic force and the moment that are exerted on the cantilever tip tend to be highly dependent on the magnetic field induced by the external magnets. Such an energy harvester can possess multi-stable potential functions, ranging from mono-stable to penta-stable. The mechanism that governs the formation of this multi-stability is thoroughly identified and examined thorough a bifurcation analysis performed on the system׳s equilibrium solutions. From this analysis, it is found that the transitions between these multi-stable states occur through very complicated bifurcation scenarios that include degenerate pitchfork bifurcations and mergers of pitchfork bifurcations or saddle-node bifurcations. Bifurcation set diagram is obtained, which is composed of five separate parametric regions, from mono- to penta-stability. The resulting stability map satisfactorily describes the multi-stable characteristics of the present energy harvester. In addition, the dynamic and energetic characteristics of the present multi-stable energy harvester are more thoroughly examined using its potential energy diagrams and a series of numerical simulations, and the obtained results are compared with those for the equivalent bi-stable cases.

Integrated Memristor-MOS (M2) Sensor for Basic Pattern Matching Applications

This paper introduces an integrated sensor circuit based on an analog Memristor-MOS (M2) pattern matching building block that calculates the similarity/dissimilarity between two analog values. A new approach for a pulse-width modulation pixel image sensor compatible with the memristive-MOS matching structure is introduced allowing direct comparison between incoming and stored images. The pulsed-width encoded information from the pixels is forwarded to a matching circuitry that provides an anti-Gaussian-like comparison between the states of memristors. The non-volatile and multi-state memory characteristics of memristor, together with the related ability to be programmed at any one of the intermediate states between logic '1' and logic '0' brings us closer to the implementation of bio-machines that can eventually emulate human-like sensory functions.

Novel Optical Multibistability and Multistability Characteristics of Coupled Active Microrings

We theoretically demonstrate the novel multibistability and multistability features of two coupled active microrings. The continuation method is utilized to solve the parametric nonlinear equations of these two-active-microring systems, and the bifurcation theory is used to investigate the special points, which exist in continuation process. The novel results, which are interpreted by the nonlinear transmission spectrum, arise from gain saturation and the optical field coupling between these two nonlinear rings. Besides the common multibistability, which consists of serial S-shaped hysterical loops, the multibistability, which takes on novel shapes, such as the hat-shaped, knife-shaped, S-shaped butterfly, and inverted double-S-shaped is also demonstrated. The novel multistability includes inverted double-S-shaped tristability, woodpecker-shaped tristability, duke-shaped tristability, grasshopper-shaped tristability, and pseudo-quadristability. The electrical and optical control processes of the stability about these two coupled active microrings are also investigated. Results show that the on-off jumping threshold of this stability can be adjusted via changing the power of the light, which inputs from the add-drop port, and the type of this stability can also be changed by altering the injected current on each active microring.

An investigation on hydrogen bonding between 3-methylindole and ethanol using trilinear decomposition of fluorescence excitation–emission matrices

The multi-state fluorescence characteristics of 3-methylindole (MI) make its spectra rich in chemical information and the spectral interpretation rather challenging. The trilinear decomposition method could be appropriate for this task and provide a deeper insight into the hydrogen bonding to MI. Taking the excitation fluorescence spectra together with the emission counterparts to formulate a three-way data array and solving the data array using the Alternating Trilinear Decomposition (ATLD) algorithm is beneficial for studying hydrogen bonding to MI in several aspects. Firstly, making full use of the excitation spectra could guarantee that the experimentally collected data contain sufficient information necessary for investigating signals originated from the weak interactions buried in the strong interaction background. Secondly, the resolution of a three-way data array could theoretically guarantee the uniqueness of the resolved component spectra with actual physical meaning. Thirdly, the ATLD algorithm resolves spectra of complex mixture and determines the spectra of corresponding individual components of different states without disturbing the complex chemical equilibrium involved. The hydrogen bonding interaction of MI with other molecules has been studied using the ATLD algorithm. A detailed investigation has been undertaken for the 1La and 1Lb states as the lowest excited singlet states which dominate the fluorescence emission of MI depending on the effect of other molecules and the surrounding microenvironment. The hydrogen bonding between indole derivatives and other molecules has been examined and some association constants involving hydrogen bond formation have been estimated and compared with theoretical simulation results or experimental observations of previous researchers.

Quantum Dot Channel (QDC) Field-Effect Transistors (FETs) Using II–VI Barrier Layers

This paper describes fabrication and modeling of quantum dot channel (QDC) field-effect transistors (FETs). A QDC-FET comprises an array of thin-barrier (~1 nm) cladded Si, Ge, or other quantum dots (3 nm to 4 nm) forming an n-channel on a p-Si layer/substrate between the source and drain regions. Experimental characteristics of fabricated QDC-FETs, consisting of two layers of cladded quantum dot arrays (e.g., SiO x -cladded Si dots and GeO x -cladded Ge dots) serving as the transport channel, are presented. Unlike conventional FETs, QDC-FET structures exhibit step-like I D–V G characteristics and discretely bunched I D–V D characteristics as a function of gate voltage. The transfer characteristics appear to be similar to those of single-electron transistors (SETs). However, QDC-FETs employ transport of many electrons and operate at room temperature. A one-dimensional Tsu–Esaki equation is used to simulate the quantum dot channel and explain the steps in the current–voltage behavior. In particular, the effect of the II–VI barrier layers on Ge dots is modeled. The QDC-FET channel is also modeled as having superlattice-like mini-energy bands whose bandwidth and separation are determined by the dot size, cladding thickness, and barrier height. For a given gate voltage (which determines the carrier concentration), carriers in the inversion channel are transported via mini-energy bands that line up with the Fermi level as the drain voltage V DS is changed, producing step-like multistate electrical characteristics. Formation of the quantum dot channel enables higher-mobility transport on very low-mobility substrates or thin films such as poly-Si. The channel mobility can be further enhanced by partially removing the oxide barrier layer and replacing it with lattice-matched II–VI gate insulator layers.

Optical multi-stability of bimesogenic cholesteric liquid crystal

In this paper, we present a multi-stable property in a bimesogenic cholesteric liquid crystal material with a proper chiral additive and check its potential as an energy saving transmissive type liquid crystal display (LCD) through its electro-optic characteristics. Experimental results show that the multi-stable characteristics in the fabricated cholesteric LC cell are very stable. Such multi-stable properties depend on the driving frequency, voltage, and field direction. The contrast ratio in the fabricated transmissive type cholesteric LC cell was 15:1, which is a result produced by voltage and frequency control.

Controlling multistability in planar nonlinear waveguides using a negative index medium

We demonstrate that a negative index medium (left-handed material) can be used to control the multistable characteristics of nonlinear waveguides. We exploit the optical antimatter like behaviour of the negative coupling layer that is index matched with the adjacent cladding layers to reduce the effective thickness between two nonlinear waveguides which leads to enhanced coupling between them. The response of a system of two coupled nonlinear waveguides can be engineered by such a index-matched negative index coupling layer to lower the switching threshold and to enhance the output intensity. However, introduction of an index-mismatched negative coupling layer, sandwiched between the nonlinear waveguides, leads to a negative waveguide that provides large coupling via its own mode structure. Furthermore, we find that a negative waveguide, as a coupler, is superior to a positive waveguide for control over multistable characteristics.

Optical study of current filaments in pin diodes

Pin diodes exhibit multistable current-voltage characteristics and selfgenerated oscillations as a result of the formation of current density filaments. The corresponding inhomogeneous distribution of charge carriers is experimentally determined by spatially resolved measurements of the infrared absorption and of the recombination radiation.

Optical multistability using optoelectronic feedback

An optical multistable device with good tuning capability was experimentally realized by using a semiconductor light-emitting device, a photodiode, and transistors with positive optoelectronic feedback. By tuning the cutoff current of each stage, optical multiple bistable and multistable loop characteristics are realized. In this device, the number of stable states is determined by the number of transistor pairs. It is noted that this device is easy to integrate and may be used in optical digital computers. A graphical solution method, as well as stability analysis of solutions, is presented to explain the operational principle of this device. >

Multistable nonlinear Fabry–Perot interferometer

The hybrid nonlinear Fabry–Pcrot interferometer is described in the multistable mode of operation. The multistable characteristics are obtained by using a multimode laser and properly adjusting the interferometer length. Self-oscillations in such a system are reported. A possible application in optical multivalued logical elements is outlined.