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Electric power material demand forecasting is an important part of power grid planning management, which helps to save power industrial costs and improve capital utilization of power companies. Due to the irregularity of historical data for electric power materials, the characteristic of electric power material demand is complicated and power grid companies lack accurate forecasting methods. By identifying the continuous and intermittent characteristics of electric power material demand, this paper separately designs the Long Short-Term Memory (LSTM) method, and the Grey prediction Model based BP neural network (GM-BP) method to individually forecast the electric power material demand with different demand characteristics. Finally, the proposed methods are tested by the practical data of an electric power enterprise, and simulation results validate that the proposed methods can effectively adapt to different features of electric power material demand as well as predict electric power material demand with good accuracy.

The transmission delay of CAN gateway message will affect the real-time performance of the whole CAN network. Firstly, the transmission delay model of CAN gateway message is analyzed in this paper. After two algorithms, ID Priority Scheduling (IDPS) algorithm and Earliest Deadline First (EDF) algorithm, are compared, the Dynamic Feedback based Hybrid Priority Scheduling (DFHPS)algorithm is proposed with implementation algorithm. Finally, Hardware In Loop (HIL) simulation test is conducted. The test results show that this method can effectively reduce the delay of high-priority messages when the network load rate is high, and ensure that low-priority messages can also get good response time.

A THz ultra-broadband absorber is realized using tunable metamaterials driven by a microfluidic system. In this work, a new technology is developed to precisely and continuously control the height of micro liquid pillars. Based on this technology, a proof-of-principle demonstration of tunable THz absorber is shown to have absorption frequency tuning from 0.245 THz to 0.415 THz with a tuning range of 51.5%. It creates a new paradigm for active metadevices based on tunable metamaterials with promising applications in detectors, sensors, imaging systems and stealth.

This paper presents the first experimental demonstration on microfluidic metasurface which can be individually controlled for electromagnetic modulator. The polarization state and intensity of reflected light can be actively modulated in a wide range of frequency (86% of central frequency). In addition, the intensity of cross polarized light in reflection can be significantly modulated, in which the modulation depth is nearly 100% for the whole frequency range. Such proposed dynamic metasurface is a good candidate for many practical applications such as tunable imaging system and optical components.

In this paper, a reconfigurable metasurface is realized using microfluidic technology, which controls the amplitude and phase of the incident wave at sub-wavelength resolution. A dispersion-corrected beam deflector and a flat lens are demonstrated for proof-of-principle where the flat lens and beam deflector are tuned, in response to the change of the incident wavelength, to maintain their functionalities. This will make various applications such as on-chip spectrometers, high-performance dispersion-controllable devices in the next-generation telecommunication networks, and wavefront-tunable devices.

In this paper, a tunable THz lens array based on reconfigurable metamaterials is reported. The metamaterial consists with 40 × 40 liquid metal microdroplets, in which the shape is tuned under different air pressures. The droplets are formed by injecting the liquid mercury into a pre-designed microchannel network and arranged to focus incident THz wave. The focus spot size can be tuned with different droplet geometries. As a result, a tunable THz lens is constructed and the smallest spot size of 0.54λ is achieved. The tunable metamaterial lens is realized through simple fabrication processes, which has potential applications in flat lens and imaging system.

Here we report a tunable THz filter based on random access metamaterial with liquid metal droplet, which is tuned through electrical bias controlled electrowetting effects. The random access metamaterial consists of 80 × 80 micro droplets, which are self-assembled in micro holes array due to lotus effect. The simulation results indicate resonant dip frequency shift of about 0.01THz induced by changing of the droplets shape via electrowetting effect and about 0.6 THz frequency shift when the droplets are connected in different forms. The random access metamaterial is realized through simple fabrication processes and can be tuned easily, which has potential application on tunable filters, tunable beam steering and flat lens. Accepted version

We demonstrate a multilayered microfluidic system with a flexible substrate, which has tunable optical chirality within THz spectrum range. The optical properties of the multilayered microfluidic system can be tuned by either changing the liquid pumped into each layer or stretching the flexible substrate. In experiment, the polarization rotation angle is tuned from zero (non-chiral structure) to 16.9°(strong-chiral structure). Furthermore, the tuning resolution can be well controlled due to the fine refractive index change of the liquid with different concentrations. It is feasible for the multilayered microfluidic structure to be integrated to an optofluidic system, where strong or tunable optical chirality are needed, which not only can be used as traditional optical components such as THz polarizers and filters but also has potential applications on imaging and sensor of bio-materials. Accepted version

In this paper, we demonstrate tunable flat lens with liquid metal. The flat lens consists of 9 × 9 split ring resonators (SRR), which can be controlled individually by a ternary-notation control system. Each SRR metamaterial unit cell is formed by liquid metal (mercury) with approximately 1.5 μL, which offer high flexibility in geometry reconfiguration. In experiment, it demonstrates freely tuning of the sub-wavelength focus point at 20-cm focus length, which is approximately 10 times of the incident wavelength.

This paper reports a micromachined metamaterial which is tunable between anisotropic and isotropic state. The tuning rescales the metamaterial lattice constant instead of changing the element structure. It realizes a resonance independent change of transmission and tunes the transmitted phase of polarized THz wave. The transmission decreases from 15% to 0 for circularly polarized wave and tunes transmitted phase up to tens of degrees for linearly polarized wave. The tunable metamaterial can be potentially applied as a THz switch, tunable attenuator and waveplate.

In this paper, we demonstrate a metamaterial tunable filter with liquid metal, which can be tuned by changing the air pressure within the channels. In experiment, it measures a 3.3-GHz tuning range for the tunable metmaterial unit with the working wavelength of 11.27 GHz. The tuning of 9 × 9 unit array is demonstrated. Different from traditional metamaterials, the metal patterns of the tunable metamaterial filter are liquid state which can be reshaped once fabricated. The liquid state metal pattern not only advances in flexible tuning method, but also results in large tuning range for vast applications, such as tunable filter, accelerometer and optical switch.

In this paper, we demonstrate a metamaterial tunable filter with liquid metal, which can be tuned by adjusting the size and position of the air gap within the liquid metal. In experiment, it measures a 2.3 GHz tuning range for the tunable metmaterial unit with the working wavelength of 8.9 GHz. The tuning of 5 × 5 unit array is also demonstrated. Different from traditional metamaterials [1, 2], the metal patterns of the tunable metamaterial filter are liquid state which can be reshaped once fabricated. The liquid state metal pattern not only advances in flexible tuning method, but also results in large tuning range for vast applications, such as tunable filter, accelerometer and optical switch.

This study proposes a neural network based nonlinear dynamic modeling method to find the predictive model of VAV systems for implementing better real-time control and optimization of VAV system performance. On studying the generalization theory of feed-forward neural networks, a dynamic VAV air-conditioned zone model is developed to simulate the system behavior under predictive control schemes. The neural model is constructed and trained with Bayesian framework combined with “early stopping” method. The model was validated against real data gathered from an existing VAV system. Validation results show that the model has high accuracy of predicted outputs and good generalization abilities.

In this paper, a Nano-opto-mechanical (NOM) switch is designed, simulated and experimentally demonstrated, using the electromagnetically induced transparency (EIT)-like effects of coupled-ring resonator. The control of the switch is realized by optical force between the silicon waveguide and the dielectric substrate. As the injection pump power increases from 0 to 6 mW, the normalized power of transmission peak at 1553.3 nm decreases from 1 to 0.02, and the position of the initial transmission peak has a 7.8-GHz red shift. The proposed NOM switch can be potentially applied in all-optical network.

A tunable laser based on double-ring external resonant cavity is designed, fabricated and tested. The double-ring resonator external cavity consists of a silicon waveguide ring resonator, a p-i-n doped silicon ring resonator, and a superluminescent diode (SLED). The laser is fabricated on a SOI wafer and the wavelength is tuned by injecting electrical currents to p-i-n structures. In the experiment, it measures 45.8 nm wavelength tuning with 110 GHz channel spacing and the average output power is approximately −8 dBm. It advances in high tuning speed, large side mode suppression ratio, and low manufacture cost, such has potential applications in high speed WDM networks.

This paper presents a MEMS switchable optical delay line, which works at terahertz (THz) region. The geometry of the unit cell is tunable by MEMS actuators [1]. In the experiment, it measures that the round trip time of the 5-µm silicon-metal cavity with the metamaterial slab is delayed by a factor of 100 when the gap of the metamaterial unit cell is shifted from 4 µm to 8 µm. Compared with the traditional tunable optical delay line [2], the metamaterial optical delay line has merits of fine tuning resolution, high tuning speed and feasible for high density integration.

This paper reports a silicon-based micromachined optical power detector with on-chip measurement ability. The optical power is detected by an integrated electron-tunneling displacement transducer, in which optical force is employed as the bridge between optical energy and mechanical energy transition. Compared with the traditional optical power detectors, which are based on photo absorption, the proposed optical power detector has advantages of small size (0.08 mm × 0.3 mm), low thermal noise (0.03 V/°C), large measurement range (> 20 mW) and wavelength independence. Therefore, it has potential applications as high-speed detecting element in silicon-based photonic chips and lab-on-chip systems.

In this paper, the microfluidic switchable absorptive metamaterials (MMs) filter in the gigahertz region is designed. It consists of a microfluidic network between the electrical resonator and the metal plate. The absorption frequency of the tunable MMs absorber can be tuned by pumping different liquids into the microchannel using the microfluidic technology. Based on the designed absorptive MMs, the absorptive peak can be shifted by introducing a microfluidic layer with frequency tunability up to 20% and absorption change up to 90%. By introducing the tunability in absorption frequency of MMs, it has great potential in the applications of filter and sensor / detector for biomedical applications.

This paper reports a 3-dimensional (3D) micro-optical coupling system for improving coupling efficiency in the Littrow configured micro-electro-mechanical system (MEMS) tunable lasers. In the coupling system, an optical fiber acts as a rod lens for light convergence in the vertical plane, while a deep-etched silicon parabolic mirror confines the light in the horizontal plane. Compared with previous MEMS lasers without any light focusing or only one-directional focusing mechanism, the proposed 3D micro-optical system allows longer external cavity length and provides higher coupling efficiency. A prototype is fabricated on a SOI-wafer with an etching depth of 100 µm. The laser obtains a coupling efficiency as high as 76.5%, which is much higher than typical value of 3% – 50% in previous designs. The laser has dimensions as small as 3 mm × 3.2 mm in single-chip integration. It achieves large tuning range of 48.3 nm within 1 ms tuning speed.

This paper presents a THz dual mode switch realized by a proper designed MEMS switchable metamaterial. The switch simultaneously controls the reflection intensity of two optical resonant modes and thus switches the ON/OFF state at two resonant frequencies. The switchable output is defined as ON state when its reflection intensity is above 65%, and OFF state if below. Furthermore, the switching between dual mode output and single mode output is also realized by suppressing one resonance mode. The proposed metamaterial dual mode switch has merits as dual mode switching and working on THz band which enable the potential applications in multi-signal control.

Under the condition of e-commerce, how to evaluate one fashion B2C e-commerce website and build the evaluating index system have important significance. Analytic Hierarchy Process (AHP) is a mathematical decision-modeling tool for solving multiple criteria decision making (MCDM) problems by decomposition, determination and synthesis. It provides the categorical and simple linear weighted average criteria ranking methods. This paper builds the evaluation model of fashion B2C e-commerce website based on online consumption by making use of hierarchical multi-level analysis. According to the establishment of evaluation model, the paper evaluates the present fashion B2C e-commerce website in China. The results have a reference value to select the fashion website for online consumer, meanwhile, and a real significance how to operate one fashion website as well.

This paper presents a terahertz tunable metamaterial filter using microelectromechanical systems (MEMS) structures. The metamaterial unit cells are tuned by micromachined comb-drive. The metamaterial slab works as a notch filter of THz region, which can lower the transmission of interest frequency down to −70 dB. In the experiment, it measures the tuning range of filter frequency from 3.32 to 3.80 THz. The tunable metamaterial filter has better tunability compared with traditional active metamaterial because the optical property of metamaterial is more sensitive to the change of the unit cell structure.

This paper presents a digital mirror for tunable laser wavelength selection using microelectromechanical systems (MEMS) technology. The digital mirror which has discrete reflection spectrum is totally different compared to the current broadband mirrors MEMS tunable lasers [1–3]. The reflection of the digital mirror can be tuned by digital pumping signals which promise fast output wavelength switching. The experimental results show that the output wavelength of the MEMS tunable laser using the digital mirror has high tuning resolution without increasing the physical length of the internal cavity of the tunable laser. The output wavelength of tuning resolution can reach 0.2 nm and the bandwidth is around 0.04 nm.

The paper presents a thermo-optic tunable laser that makes use of a micromachined etalon to form the external cavity. The wavelength tuning is obtained by the thermo-optic effect of the silicon material. In experiment, a wavelength tuning range of 14 nm is demonstrated by applying a heating current of 18.7 mA to a deep-etched silicon etalon of 206 ?m wide. In the dynamic test, this laser measures a tuning speed of 3.2 ?s, which is much faster than the typical speed of 1 ms as given by the previous MEMS tunable lasers that rely on the motion of mirrors or gratings. Since this laser is based on a different tuning mechanism of thermo-optic effect and requires no mechanical movement, it possesses many advantages such as fast speed, simple configuration and planar structure, and will broaden the applications of MEMS tunable lasers.

This paper presents a micromachined tunable laser that utilizes a silicon optical tunneling structure to tune both the polarization state and the wavelength of the laser output. The device is fabricated on silicon-on-insulator wafer using deep reactive ion etching. In experiment, the wavelength and the polarization are tuned by heating up the silicon optical tunneling structure via the thermo-optic effect. A 90° change of polarization direction is obtained using a heating current of 61.2 mA, and a wavelength tuning of 2 nm is also demonstrated. The output spectrum shows a high suppress ratio above 30 dB. Compared with the previous MEMS tunable lasers that have a random or fixed polarization state, this device provides a special capability in tuning the polarization state in addition to the wavelength, and would find niche applications in biomedical research, interferometry, coherent communications, instrumentations and sensors.

This paper presents a thermooptic switch based on the optical tunneling effect of a double optical barriers system. By introducing a new physical mechanism of the optical tunneling effect into micro-electro-mechanical systems (MEMS) technology, a switching contrast of more than 30 dB with a response time of less than 3 mus are obtained. Compared with the previously reported thermo-optic switches, this design requires very small change in refractive index for switching (Deltan ap 10-4), which is only 1/10 of the typical requirement. It has fast tuning speed and low power consumption.

This paper presents a movable gold waveguide for switching surface plasmon polariton (SPP) using the MEMS technology, which provides a simple but effective way to route the SPP. The input waveguide is patterned on top of a cantilever beam, and can be actuated to align the input to one of the two output gold waveguides fixed on the substrate. The gold waveguides are 2- mum wide and 40-nm thick patterned on a silicon substrate through a SiO2 layer. This is the first attempt to realize active switching function of SPP and would help push the SPP from physical study to applicable devices.

Summary form only given. An intelligent CAD system based on parallel processing technique is described. Its hardware is an MIMD parallel system consisting of a microcomputer and multi-transputers, and the software is developed with the mixture of C language and Occam language. The CAD system adopts a feature representation scheme so as to support integrated manufacturing. A new feature model is introduced as a pair of a product model to improve design representation in a computer-integrated manufacturing environment. The feature model is a surface based design representation scheme, and has a general modeling space with a limited number of features. The system described has strong capacity for numerical computation, graphics processing and intelligent inference that ordinary sequential CAD system on microcomputers or even workstations cannot possess. However, we find that the development of its software is much more difficult than sequential ones due to currently lacking of parallel procedures that can be directly used, and some aspects need to be further studied and improved.