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Automatic incident detection (AID) has always been one of the focus issues in the field of transportation. However, due to the contingency and randomness of traffic incident, traffic incident samples are scarce and far less than non-incident samples. Therefore, unlike other scenarios using large-scale deep networks, traffic incident detection tackle at small and imbalanced sample size. Imbalanced, small sample data sets, inappropriate and incomplete initial variable sets make the AID model insensitive to incident samples, resulting in unsatisfactory model performance (low detection rate or high false alarm rate). Therefore, a hybrid AID method (SASYNO-RF-RSKNN) is proposed using self-adaptive synthetic over-sampling, random forest and random subspace k nearest neighbor. First, the spatial-temporal and real-time characteristics of traffic stream are used for the selection of appropriate initial variables to construct a relatively complete set of initial variables. Second, the SASYNO oversampling method is used to expand the original imbalanced sample database, so that the number of minority class samples is consistent with the number of most class samples. Then, feature variables are selected from the initial variables using the RF algorithm. Finally, the RSKNN ensemble algorithm with feature variables as input is employed to detect traffic incident. In addition, six indexes are used to evaluate model performance, including accuracy (ACC), false alarm rate (FAR), detection rate (DR), precision, Matthews correlation coefficient (MCC) and F1-score. Simultaneously, we also designed horizontal and vertical contrast experiments, and the experimental results show that SASYNO-RF-RSKNN model has superior performance. It is worth mentioning that experiments are implemented on two real-world datasets. Most indexes of the proposed model are the best compared with other five excellent machine learning algorithms. On the whole, the proposed model has a dependable and high-performance for traffic incident detection.

Aggregate thermostatically controlled loads (ATCLs) are a suitable candidate for power imbalance on demand side to smooth the power fluctuation of renewable energy. A new control scheme based on an improved bilinear aggregate model of ATCLs is investigated to suppress power imbalance. Firstly, the original bilinear aggregate model of ATCLs is extended by the second-order equivalent thermal parameter model to optimize accumulative error over a long time scale. Then, to ensure the control performance of tracking error, an improved model predictive control algorithm is proposed by integrating the Lyapunov function with the error transformation, and theoretical stability of the proposed control algorithm is proven. Finally, the simulation results demonstrate that the accuracy of the improved bilinear aggregate model is enhanced; the proposed control algorithm has faster convergence speed and better tracking accuracy in contrast with the Lyapunov function-based model predictive control without the prescribed performance.

With the development of the mobile Internet, novel things are constantly emerging, and among them, online car-hailing is one of the representatives. However, the rapid development of online car-hailing also brings about normative problems and safety loophole, the most prominent of which is the inconsistency between operating cars and registered drivers. Some existing algorithms based on curve similarity measurements, such as Hausdorff distance and discrete Fréchet distance, can be used to solve this problem. However, they only consider one of the characteristics of the two curves, such as the distance or the area between two curves, which does not achieve good results on this problem. On this ground, we propose a model based on curve comparison, named multi-feature fusion (MFF), which extracts the features of length, distance, and area from the GPS positioning track of car and the application mobile phone of the driver, to testify whether the car is being operated by the registered driver and thus solving the problem of mismatch between the driver and the car during the operation. Among them, the MFF model designs different algorithms for different features and fuses different features by an ensemble learning method. The experimental results prove that the model can effectively detect the mismatch between drivers and cars.

In many fields, e.g., ground-penetrating radar and ultra-wideband radiation, a high-pulse-repetition-frequency (PRF) and high-time-base-stability sub-nanosecond pulser is required, and its output waveform should be close to a gaussian pulse. In this article, the transistorized pulser is studied and optimized to improve its output parameters. The printed circuit board circuit parameters of the pulser are first optimized, which is beneficial for the amplitude and the rise time. To improve the time base stability, the collector voltage ramp triggering mode is adopted to replace the conventional base triggering mode for the pulser. For higher PRF, the pulser with the capacitance–transistor parallel structure is immersed in the fluorinert liquid. Moreover, the deficit-charge method is adopted, and small charging capacitances are used in the last few stages to weaken the oscillation in the pulse falling edge. From experimental results, the amplitude of the optimized pulser is 1.35 kV, its rise time is reduced from about 200 to 135 ps, the maximum PRF is improved from 250 to 500 kHz, the pulse jitter is reduced to 22 ps, and the pulse drift is reduced from hundreds of ps/min to 47 ps/min. Meanwhile, the oscillation in its falling edge is greatly suppressed. [ABSTRACT FROM AUTHOR]

In this letter, an all-metallized wideband dual circularly polarized antenna with endfire radiation is proposed for fifth-generation (5G) millimeter-wave applications. By introducing two rectangular notches on the side walls of open-ended waveguide, the vertical components are increased and close to the horizontal components in the broadband range so that the axial ratio (AR) bandwidth is enhanced. The simulated results show that the proposed antenna excited by wave port has 63.9% operation bandwidth (22.7–44.0 GHz), where reflection coefficients less than −10 dB, isolations greater than 20 dB, and AR less than 3 dB are achieved. To verify the design, the proposed antenna excited by coaxial connectors is fabricated and measured. Based on the measurement results, the reflection coefficients less than −10 dB, isolations greater than 20 dB, and AR less than 3 dB are achieved from 23.0–40.0 GHz, the endfire gain varies from 5.1 to 8.5 dBic at the frequencies mentioned above. [ABSTRACT FROM AUTHOR]

We proposed a new reservoir computation (RC) structure using polarization dynamics of vertical cavity surface emitting lasers (VCSELs) with optoelectronic feedback. Santa-Fe time-series prediction and nonlinear channel equalization were used to evaluate its parallel processing capability. We numerically discussed the effects of feedback strength, injection strength, frequency detuning, injection current and scaling factors on the RC performance of the system. The results show that, the operation range of negative feedback is larger than that of positive feedback; under appropriate feedback and lager injection strengths, good RC performance can be achieved for a wider injection current; with continuous variation of feedback strength from negative to positive values, the optimized location for frequency detuning moves from positive to negative values. We also evaluated the processing rate of proposed RC structure. The related study is helpful for the design and optimization of VCSEL-based RC under optoelectronic feedback. [ABSTRACT FROM AUTHOR]

Irradiating hohlraum targets with high-power laser pulses is a promising approach to achieve inertial confinement fusion (ICF). Unfortunately, such interaction is accompanied by intense electromagnetic pulses (EMPs). The EMPs can interfere with various physical diagnostic signals and even cause a malfunction of some crucial equipment. In this study, EMPs generated due to kJ-laser coupling with hohlraum targets are recorded using B-dot probes inside the target chamber. The configuration of the hohlraum has a more remarkable effect on EMP amplitudes compared to laser energy. 0.6 mg/cc of He gas filling in the hohlraum and the presence of the capsule inside the hohlraum both dramatically reduce EMPs. Moreover, EMP frequencies corresponding to various hohlraums are basically below 1.75 GHz. Soft X-ray (0.1–4 keV) radiant flux is used to reveal the characteristics of EMPs. The conclusions are expected to enable us to better understand the relationship of EMPs with target configuration and laser energy. [ABSTRACT FROM AUTHOR]

As an important part of rotating machinery, gear is easy to appear some unexpected fault states, and its fault diagnosis is very important. Fourier decomposition method (FDM) is a common method for gear fault diagnosis, but the noise robustness, period recognition, and extraction capabilities of FDM are unsatisfactory. Based on this, in this article, Ramanujan Fourier mode decomposition (RFMD) method is proposed. The RFMD not only has a complete mathematical theory foundation but also has an excellent ability to identify and extract periodic components. Emulational and experimental results of planetary gearbox show that the RFMD method has good noise robustness and can accurately extract gear fault characteristic information. Thus, it is an effective gear fault diagnosis method. [ABSTRACT FROM AUTHOR]

We theoretically and experimentally investigate broadband manipulation of Stokes frequency comb generation in a silica microbottle resonator. We realize selective excitation of spectrally trapped Stokes combs belonging to distinct transverse mode families and a spectral tuning range up to ∼14.3 nm via coupling engineering by exciting distinct axial mode families with appropriate quality factors (Qs). Moreover, radial mode number selection, microcavity diameter control, or injection power adjustment also enables us to shift the Stokes comb wavelength. The tuning bandwidth can be extended to hundreds of nanometers by theoretical prediction using the bottle modal analysis and Coupled Lugiato Lefever (LL) equations simulation. We also show that multiple regimes in two-dimensional (2D) patterns can be selectively triggered depending on the cavity detuning, including Kerr frequency comb, single-frequency Raman lasing, multimode Raman lasing, and soliton crystal-like state. Our approach provides a scheme for greatly extending the wavelength tuning range of compact Raman laser devices with high performance. [ABSTRACT FROM AUTHOR]

Understanding and predicting real-time vehicle mobility patterns on highways are essential to address traffic congestion and respond to the emergency. However, almost all existing works (e.g., based on cellphones, onboard devices, or traffic cameras) suffer from high costs, low penetration rates, or only aggregate results. To address these drawbacks, we utilize Electric Toll Collection systems (ETC) as a large-scale sensor network and design a system called VeMo to transparently model and predict vehicle mobility at the individual level with a full penetration rate. Our novelty is how we address uncertainty issues (i.e., unknown routes and speeds) due to sparse implicit ETC data based on a key data-driven insight, i.e., individual driving behaviors are strongly correlated with crowds of drivers under certain spatiotemporal contexts and can be predicted by combining both personal habits and context information. We evaluate VeMo with (i) a large-scale ETC system with tracking devices at 773 highway entrances and exits capturing more than 2 million vehicles every day; (ii) a fleet consisting of 114 thousand vehicles with GPS data as ground truth. Compared with state-of-the-art benchmark mobility models, the experimental results show that VeMo outperforms them by 10 percent on average. [ABSTRACT FROM AUTHOR]

The transverse magnetic field (TMF) contacts generate a magnetic field through the structure and apply electromagnetic force to the arc to drive the arc to move on the surface of the contact. When the arc rotates on the surface of the spiral-type TMF contact, it needs to continuously cross the slots in the surface, so that the current is transferred between the contact arms. The structure of the slot not only determines the magnitude of the electromagnetic force of the arc during its movement, but also directly affects the arc’s appearance and speed during its motion. At present, most researches on spiral-type TMF contacts focus on increasing the strength of TMF and enhancing the force on the arc, but there is little research on the influence of the arc’s appearance during the slot crossing process. In this article, two spiral-type TMF contact structures are selected for experiments, the appearance of the arc in the slot crossing process is studied and analyzed, and the arc characteristics in different slot crossing processes are summarized. It is found that the anode plasma jets can keep moving with low concentration, which plays an important role in the slot crossing process and the current breaking. [ABSTRACT FROM AUTHOR]

Weakly-coupled space division multiplexing (SDM) techniques based on multi-core fibers (MCF) have attracted great attention for the capacity enhancement of optical interconnect systems and networks. In this paper, we propose a novel direct-laser-writing (DLW) core separator device and apply it in a reconfigurable optical add/drop multiplexer (ROADM) structure for two-dimensional SDM and wavelength division multiplexing (WDM) switching. The proposed core separator matching an 8-core MCF is fabricated. Then assisted with MCF rotators, independent adding and dropping functionalities for arbitrary core are experimentally demonstrated with slight power penalty for both core and wavelength dimensions. The influence of crosstalk for cascading core separators is also investigated and below 0.35-dB receiving sensitivity penalty is obtained when three cores are dropped one by one. The compact DLW core separators can reduce the complexity of SDM nodes and will be beneficial for high-speed optical interconnects. [ABSTRACT FROM AUTHOR]

The nondestructive volumetric imaging technique to characterize a three-dimensional (3D) refractive index (RI) profile quantitatively is an essential tool for designing, fabricating, and evaluating photonic structures of various devices. Conventional 3D RI imaging methods usually depend on the sample rotation scheme, which finds it difficult to measure the RI distribution of sheet-like on-chip structures. In this study, we proposed an optical diffractive tomography (ODT) system by employing a galvanometric scanner to reconstruct on-chip waveguide RI profiles; the measured volumetric RI dimension was 63 × 63 × 32 μm3 in a single measurement, and the RI sensitivity was up to 0.0015. The reliable reconstruction results proved that the proposed ODT system is a promising tool for quantitatively retrieving RI profiles of photonic devices. [ABSTRACT FROM AUTHOR]

The application of inter-vehicle wireless communication offers significant advantages in terms of improving traffic efficiency and safety while also suffering from unreliable communication links. This paper deals with the problem of event-triggered vehicular platoon control with communication time delay and package dropout, aiming to achieve a suitable trade-off between communication utilization and vehicle following performance. A disturbance based platoon model with communication time delay, package dropout and event-triggered scheme is established. Subsequently, the criterion for co-designing the event-trigger parameters and CACC controller parameters is derived by adopting the parameter space approach with the requirements to ensure individual vehicle internal stability, following accuracy and platoon string stability. To achieve a superior trade-off between communication resource utilization and following performance under unreliable communication condition, the adaptive event-triggered threshold is designed for the varying failure probability. The effectiveness of the proposed adaptive CACC strategy is verified using numerical simulations of a six-vehicle platoon during the FTP 72 drive cycle. The comparison results of three different scenarios show that the adaptive event-triggered scheme guarantees the following performance even when failure probability is 0.4. [ABSTRACT FROM AUTHOR]

High precise IQ skewcalibration of the coherent optical transceiver is crucial for high baud rate and high-order modulation formats optical transmission system. In this paper, a novel high precise optical coherent transceiver calibration method based on the specially designed interleaved in-phase (I) and quadrature-phase (Q) multi-tone signals is proposed. This method can simultaneously characterize the transmitter (Tx) and receiver (Rx) side IQ skew by just one measurement without using any additional device or training process. Because of the non-overlapping characteristic of these interleaved I and Q signals in the frequency domain, the IQ crosstalk in the coherent optical transceiver can be effectively avoided, contributing to high-precision calibration. Since the calibration process only focuses on the phase frequency response characteristic, the dynamic range of IQ skew calibration can easily reach dozens of picoseconds. Theoretical analysis and simulation results indicate that the measurement accuracy of the Tx skew and Rx skew is within ±0.2 ps in the proposed scheme, and the dynamic range of IQ skew calibration can reach ±40 ps. With the help of this IQ skew calibration method, the transmission performance improvement is experimentally verified in both single-polarization 30 GBaud 32QAM signal and dual-polarization 30 GBaud 16QAM signal transmission systems. [ABSTRACT FROM AUTHOR]

We report a 3-year city-wide study of an operational indoor sensing system based on Bluetooth Low Energy (BLE) called aBeacon (short for alibaba Beacon). aBeacon is pilot-studied, A/B tested, deployed, and operated in Shanghai, China to infer the indoor status of Alibaba couriers, e.g., arrival and departure at the merchants participating in the Alibaba Local Services platform. In its full operation stage (2018/01-2020/04), aBeacon consists of customized BLE devices at 12,109 merchants, interacting with 109,378 couriers to infer their status to assist the scheduling of 64 million delivery orders for 7.3 million customers with a total amount of $\$ $ 600 million order values. Although in an academic setting, using BLE devices to detect arrival and departure looks straightforward, it is non-trivial to design, build, deploy, and operate aBeacon from its conception to its retirement at city scale in a metric-based approach by considering the tradeoffs between various practical factors (e.g., cost and performance) during long-term system evolution. We report our study in two phases, i.e., an 8-month pilot study and a 28-month deployment and operation in the wild. We focus on an in-depth reporting on the five lessons learned and provide their implications in other systems with long-term operation and broad geospatial coverage, e.g., Edge Computing. [ABSTRACT FROM AUTHOR]

An interesting hydrogen (H2) gas sensor, synthesized by an indium oxide (In2O3) layer and evaporated palladium (Pd) nanoparticles (NPs), is manufactured and studied. The utilized Pd NPs essentially enhance the surface area/volume (${S}_{A}/{V})$ ratio and catalytic reactivity of the Pd metal. Energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), high-resolution scanning electron microscopy (HRSEM), and TEM were used to investigate the relevant material behaviors of the proposed Pd NP/In2O3 sensor device. The sensing mechanism is explicated in this study. A very high-sensing response of 5243 under 1% H2/air gas with a response time of 12 s and an extremely low-detecting content of 100 ppb H2/air were obtained at the optimal operating temperature of 225 °C. In addition, excellent selectivity toward hydrogen gas is observed for the studied device. The proposed sensor also shows advantages of simple structure, low-cost, and relatively easy fabrication process. [ABSTRACT FROM AUTHOR]

As IC components become denser and smaller in a package, more problems emerge. In the mold filling process, because epoxy molding compound (EMC) contains approximately 80 wt.% silica fillers, the fillers may clog at the gate of gap if the gap height between the component and the substrate is too small. This clogging will cause a popcorn effect due to the high resin content in the gap. In order to determine the EMC filling process in the mold cavity and the relation between the gap height and the filler size, we simulate the EMC filling process and the EMC filler concentration distribution in the mold cavity using mold flow analysis software and then use computational fluid dynamics-discrete element method (CFD-DEM) coupling method to simulate the EMC filler motion to determine the relationship between gap height and filler size and the factors that affect filler clogging. Based on the mold flow analysis results, the filler concentration was higher at the gate of gap than in other regions, and the filler concentration at the gate of gap for the 30- $\mu \text{m}$ gap-height model was higher than that for the 50- $\mu \text{m}$ gap-height model. Based on the DEM-CFD coupling results, particles with a single diameter larger than one-half of the gap height caused particle clogging the gate of gap, and particles with a mean particle size larger than one-third of the gap height caused particle clogging the gate of gap. [ABSTRACT FROM AUTHOR]

The heating, ventilation, and air-conditioning (HVAC) system account for substantial energy use in buildings, whereas a large group of occupants is still not actually feeling comfortable staying inside. This poses the issue of developing energy-efficient HVAC control, i.e., reduce energy use (cost) while simultaneously enhancing human comfort. This brief pursues the objective and studies the stochastic optimal HVAC control subject to uncertain thermal demand (i.e., the weather and occupancy). Particularly, we involve the elaborate predicted mean vote (PMV) thermal comfort model in the optimization. The problem is computationally challenging due to the nonlinear and nonanalytical constraints imposed by the system dynamics and PMV model. We make the following contributions to address it. First, we formulate the problem as a Markov decision process (MDP) which is a desirable modeling technique capable of handling the complexities. Second, we propose a gradient-based learning (GB-L) method for progressively learning a stochastic control policy off-line and store it for on-line execution. Third, we prove the learning method’s converge to the optimal policies theoretically, and its performance (i.e., energy cost, thermal comfort, and on-line computation) for HVAC control via simulations. The comparisons with the existing model predictive control based relaxation (MPC-R) method which is assumed with accurate future information and supposed to provide the near-optimal bounds show that though there exists some discount in energy cost reduction (i.e., 6.5%), the proposed method can enable efficient on-line implementation (less than 1 s) and provide a high probability of thermal comfort under uncertainties. [ABSTRACT FROM AUTHOR]

This communication presents the design of a wideband circularly polarized (CP) antenna array based on sequential rotation (SR) technique that is excited by a substrate integrated coaxial line (SICL) with mature and stable processing technology for millimeter-wave (mm-wave) applications. Initially, the influence of the amplitude and phase errors of the feeding network on the axial ratio of the CP array is analyzed, and the detailed design scheme of the wideband CP array based on SR technology is summarized, which can be used to design SR CP array with wide bandwidth and high polarization purity. Then, an SICL-fed $4 \times 4$ CP array working in the mm-wave band that is composed of two substrate layers and a bonding film layer is designed. The radiation element is processed with a larger chamfering, which can realize elliptically polarized radiation in a broadband range, and the impedance bandwidth is significantly expanded relative to the working state of linearly polarized and CP, which has a significant impact on the final array working bandwidth enhancement. The feeding network and radiation elements are directly connected in the same plane. Finally, the proposed antenna is processed and measured to verify the theory and design scheme in this communication. Over the frequency range of 25.0–34.0 GHz, the measured 1.5 dB axial ratio bandwidth of the fabricated prototype is 30.5%, and the return losses are less than −10 dB. The maximum measured peak gain is 16.5 dBi. [ABSTRACT FROM AUTHOR]

The nonlinear effects in optical resonators give a promise for the generation of new laser sources. Here, a whispering gallery mode(WGM) micro-rod resonator is fabricated and the mechanism of transmission between Kerr comb to Raman comb is investigated by experimental results and amended Lugiato-Lefever equation(LLE) model. We show that, numerically and experimentally, the WGM resonator-based optical frequency comb can be selectively accessed from Kerr comb state to Kerr-Raman state via pump and detuning controlling. When the detuning is initially set at red detuning, by simply increasing the pump power, the comb state can lock to the stable Raman soliton comb. This indicates the Raman soliton comb is easier to generate compared to the Kerr soliton comb in silica-based WGM resonator. We wish the experimental results demonstrated here can be used for broadband comb applications. [ABSTRACT FROM AUTHOR]

Compared to single-level-cell (SLC) mode operation, triple-level-cell (TLC) mode operation reduce NAND Flash lifetime due to its stronger program $/$ erase ($\text{P}/\text{E}$) cycled-induced oxide degradation and narrower read margin between neighboring states. However, by measuring the evolution characteristics of raw bit error rate (RBER) and threshold voltage ($\text{V}_{\text {t}}$) shift during retention bake, TLC-erase $/$ SLC-program mix-mode $\text{P}/\text{E}$ sequences in 3-D NAND Flash memory exhibits significant retention deterioration compared with pure TLC-mode $\text{P}/\text{E}$ schemes. Based on our measurement results, mix-mode operation may create more residual holes in the inter-gate spacing (IGS) region, giving rise to enhanced lateral migration of trapped charge in silicon nitride (SiN) storage layer and the larger $\text{V}_{\text {t}}$ retention loss accordingly. [ABSTRACT FROM AUTHOR]

This article presents a cooperative volt-ampere reactive (C-VAR) control strategy to regulate voltage while reducing incurred power loss for a photovoltaic (PV) enabled grid experiencing abnormal (unexpected and extremely high) real power loads. The proposed C-VAR method only requires limited communications about power flow and voltage in a subset of nodes locally and is optimization-free. Thus, it is particularly suitable for the real-time voltage control for a distributed large-scale power grid. For demonstration purposes, C-VAR is evaluated using the IEEE 123-node test feeder and compared with benchmark solutions, such as the IEEE Standard 1547 and centralized model predictive control. The results show that C-VAR does not incur too much power loss and quickly drives the voltage back to the desired range under high power loads and PV indeterminacy. [ABSTRACT FROM AUTHOR]

This article studies a scalable control method for multizone heating, ventilation, and air-conditioning (HVAC) systems to optimize the energy cost for maintaining thermal comfort (TC) and indoor air quality (IAQ) (represented by CO2) simultaneously. This problem is computationally challenging due to the complex system dynamics, various spatial and temporal couplings, as well as multiple control variables to be coordinated. To address the challenges, we propose a two-level distributed method (TLDM) with an upper level and lower level control integrated. The upper level computes zone mass flow rates for maintaining zone TC with minimal energy cost, and then, the lower level strategically regulates zone mass flow rates and the ventilation rate to achieve IAQ while preserving the near energy-saving performance of upper level. As both the upper and the lower level computation are deployed in a distributed manner, the proposed method is scalable and computationally efficient. The near-optimal performance of the method in energy cost saving is demonstrated through comparison with the centralized method. In addition, the comparisons with the existing distributed method show that our method can provide IAQ with only little increase of energy cost, while the latter fails. Moreover, we demonstrate that our method outperforms the demand-controlled ventilation (DCVs) strategies for IAQ management with about 8%–10% energy cost reduction. Note to Practitioners: The high portion of building energy consumption has motivated the energy saving for heating, ventilation, and air-conditioning (HVAC) systems. Concurrently, the living standards for indoor environment are rising among the occupants. Nevertheless, the status quo on improving building energy efficiency has mostly focused on maintaining thermal comfort (such as temperature), and the indoor air quality (IAQ) (usually represented by CO2 level) has been seldom incorporated. In our previous work with the similar setting, we observed that the CO2 levels will surge beyond tolerance during the high occupancy periods if only thermal comfort (TC) is considered for HVAC control. This deduces the IAQ and TC should be jointly considered while pursuing the energy cost saving target and thus studied in this article. This task is computationally cumbersome due to the complex system dynamics (thermal and CO2) and tight correlations among the different control components (variable air volume and fresh air damper). To cope with these challenges, this work develops a two-level distributed computation paradigm for HVAC systems based on problem structures. Specifically, the upper level control (ULC) first calculates zone mass flow rates for maintaining comfortable zone temperature with minimal energy cost, and then, the lower level strategically regulates the computed zone mass flow rates as well as ventilation rate to satisfy IAQ while preserving the near energy-saving performance of the ULC. As both the upper and lower level calculations can be implemented in a distributed manner, the proposed method is scalable to large multizone deployment. The method’s performance both in maintaining comfort (i.e., TC and IAQ) and energy cost saving is demonstrated via simulations in comparisons with the centralized method, the distributed token-based scheduling strategy, and the demand-controlled ventilation strategies. [ABSTRACT FROM AUTHOR]

Mining the relationship structures among the investors plays a vital role in promoting economic development as well as preventing financial risks, especially in the context of big data. This article proposes fast networking approaches from investment big data to explore three underlying structures, namely, investment pedigrees, investment groups, and structural holes. Inspired by disjoint sets and path compression, we first present a pedigree classification algorithm to identify investment pedigrees. Second, through introducing a pruning strategy and a data structure termed as “2-tuple list,” we develop a novel linear-time structure mining algorithm in network (SMAN) for investigating investment groups and structural holes from the investment pedigree. Finally, we show that our SMAN has higher clustering accuracy and efficiency than other existing algorithms on a variety of real-world tasks in terms of normalized mutual information (NMI) values. Our method is particularly well suited for mining the underlying structures from investment big data. [ABSTRACT FROM AUTHOR]

Microbottle resonators (MBR) have attracted research interest for studying nonlinear optical interactions in last two decades, due to the ultra-tight optical confinement in spaces of three dimensions. In this paper, silica MBRs exhibiting rich resonant modes with ultra-high quality factor up to $3.73 \times {10^8}$ are demonstrated, based on which a portable and robust packaged platform with a tapered fiber coupling is established. Such a packaged platform effectively avoids external perturbations such as air flow and tiny mechanical vibrations, which supports our experimental demonstration of nonlinear scattering effects including four-wave mixing (FWM), simulated Raman scattering, and simulated Brillouin scattering. As a result, Raman-assisted FWM and Brillouin-assisted FWM are observed due to the strong field enhancement in the MBR. In a further investigation, a Kerr frequency comb with broad bandwidth of ∼200 nm and a Raman-assisted comb with a bandwidth up to ∼50 nm is achieved, correspondingly. Our works show the versatility of MBR for fundamental research and may open a new route to the development of practical applications in frequency conversion, spectroscopy and communications. [ABSTRACT FROM AUTHOR]

This paper studies an energy storage (ES) sharing model which is cooperatively invested by multiple buildings for harnessing on-site renewable utilization and grid price arbitrage. To maximize the economic benefits, we jointly consider the ES sizing, operation, and cost allocation via a coalition game formulation. Particularly, we study a fair ex-post cost allocation based on nucleolus which addresses fairness by minimizing the minimal dissatisfaction of all the players. To overcome the exponential computation burden caused by the implicit characteristic function, we employ a constraint generation technique to gradually approach the unique nucleolus by leveraging the sparse problem structure. We demonstrate both the fairness and computational efficiency of the method through case studies, which are not provided by the existing Shapley approach or proportional method. Particularly, only a small fraction of characteristic function (less than 1% for 20 buildings) is required to achieve the cost allocation versus the exponential information required by Shapley approach. Though there exists a minor increase of computation over the proportional method, the proposed method can ensure fairness while the latter fails in some cases. Further, we demonstrate both the building-wise and community-wise economic benefits are enhanced with the ES sharing model over the individual ES (IES) model. Accordingly, the overall value of ES is considerably improved (about 1.83 times). 1 The proportion of total electricity bill reduction relative to the ES capital cost. [ABSTRACT FROM AUTHOR]

The surge of plug-in electric vehicles (PEV) on the roads poses the issue to handle the substantial charging demand. Particularly, the operation of charging stations requires an efficient and scalable real-time scheduling method to accommodate the dramatic charging requests in an economical (i.e., to best utilize the local renewable generation) and friendly (i.e., to reduce the impact on the electric grid) manner. This paper fulfills the objectives and makes the following main contributions. First, we develop a parameterized aggregated PEV charging model using the energy boundaries to express the charging flexibility. We propose to parameterize the aggregated charging policy by the incomplete Beta function based on the problem structures. The proposed model can scale down the decision variables from $O(NH)$ to $O(2)$ where $N$ is the number of PEVs and $H$ is the number of prediction horizon. Second, we develop an ordinal optimization (OO) based method (denoted as OO-P) to search for good enough charging policies within seconds while still providing probabilistic performance guarantee. Third, we demonstrate the performance of the proposed OO-P via simulations. The numerical results show that the solution of OO-P is only 4% worse than the optima. However, OO-P shows high computation efficiency and scalability. Compared with the existing real-time PEV charging scheduling method, OO-P can reduce 6% of the operation cost for the charging station. OO-P is also shown to outperform the existing heuristic rule. [ABSTRACT FROM AUTHOR]

A dynamic splint is superior to traditional static splint, offering more benefits such as reduced spasticity, allowing comfortable stretch, repositioning fingers in extension positions, and increasing hand performance. This paper suggested the development of a dynamic splint based on a pulley rotation with a locking system as a home rehabilitation device to reduce hand spasticity in stroke patients. Moreover, this study consisted of two main activities: simulation using finite element analysis and clinical experimental trials. Eight stroke patients participated in 4 weeks of intervention using the proposed dynamic splint for a combined total of least 3 hours per day at home. Outcome measures included Fugl-Meyer Assessment (FMA) and Modified Modified Ashworth Scale (MMAS) at baseline, 2 weeks, and 4 weeks. After 4 weeks of wearing, participants were also asked to fill out a satisfaction questionnaire. The results showed that wearing this proposed dynamic splint over 4 weeks, the hand function of participants increased significantly(p < 0.05), and the spasticity of the hand muscles decreased significantly(p < 0.05). With an overall rating of 8 out of 10 points, stroke participants had a high level of satisfaction with this home-use dynamic splint. The findings indicated that stroke patients who used this proposed splint showed substantial changes in hand function and reduced hand spasticity. [ABSTRACT FROM AUTHOR]

Recently, few-mode Erbium-doped fiber amplifiers (FM-EDFA) for mode-division multiplexing (MDM) transmission have attracted much interest. In this paper, we propose a novel few-mode gain-flattening filter (FM-GFF) based on long-period fiber gratings (LPFG) in double-cladding few-mode fiber (DC-FMF). Due to weak coupling among all the core modes and limited number of inner-cladding modes, the phase matching condition for a specific FM-LPFG can be satisfied only between one core mode and one inner-cladding mode each time and independent gain flattening can be realized for each core mode without influencing the other ones. Moreover, both DC-FMF and transmission FMF have the same core refractive index and radius, while the inner-cladding of DC-FMF and the cladding of transmission FMF have the same refractive index, which can effectively maintain the weakly-coupled condition for their connections. We show by simulation that the output gain spectra for all the 4 or 6 linearly-polarized (LP) core modes in two kinds of DC-FMFs can be independently flattened to less than 0.6-dB in the whole C-band by the cascading LPFGs in the DC-FMF. The proposed FM-GFF scheme is beneficial for the practical design of FM-EDFAs. [ABSTRACT FROM AUTHOR]

Influence analysis aims at detecting influential vertices in networks and utilizing them in cost-effective business strategies. Influence analysis in large-scale networks is a key technique in many important applications ranging from viral marketing and online advertisement to recommender systems, and thus has attracted great interest from both academia and industry. Early investigations on influence analysis often assume static networks. However, it is well recognized that real networks like social networks and the web network are not static but evolve rapidly over time. Thus, to make the results of influence analysis in real networks up-to-date, we have to take network evolution into consideration. Incorporating evolution of networks into influence analysis raises many new challenges, since an evolving network often updates at a fast rate and, except for the network owner, the evolution is usually even not entirely known to people. In this survey, we provide an overview on recent research in influence analysis in evolving networks, which has not been systematically reviewed in literature. We first revisit mathematical models of evolving networks and commonly used influence models. Then, we review recent research in five major tasks of evolving network influence analysis. We also discuss some future directions to explore. [ABSTRACT FROM AUTHOR]

This paper presents the feature extraction, selection and K-Nearest Neighbors (K-NN) algorithm to classify behaviors of sharks based on the data collected by tri-axial acceleration data loggers (ADLs). Because these behaviors are hard to observe in the wild and do not occur frequently, being able to adequately classify them is extremely challenging. In the proposed scheme, we first employ several transformations to enrich the static and dynamic acceleration data. Then, the enhanced data is converted from time to the frequency domain through the fast Fourier transform (FFT) for noise removal. A modified K-NN approach integrated with feature selection is developed and conducted on the frequency domain data to improve the F1-score for minority classes. The acceleration data of California horn sharks (Heterodontus francisci) gathered through ADLs mounted on the first dorsal fin is used to demonstrate our algorithm. A comparison study shows that the features extracted and selected by our proposed scheme can significantly improve the performance of classification on the imbalanced dataset. [ABSTRACT FROM AUTHOR]

A sub-sampling phase-locked loop (SSPLL) with loop bandwidth calibration is presented. By using a sub-sampling phase detector with gain calibration and a pulse width control circuit, the loop bandwidth deviation of the SSPLL can be reduced. This SSPLL is fabricated in a 40 nm CMOS process and its core area is 0.15mm2. The power consumption of the SSPLL is 5.81mW from a supply of 1.1V. The reference frequency is 75 MHz and the output frequency range of the SSPLL is 2.4~3.0GHz. The measured rms jitter is 2.02ps at the output frequency of 3.0GHz. With the calibration, the largest loop bandwidth deviation from 3.5MHz among five samples is reduced from −71.4% to −18.5% at 3.0GHz. [ABSTRACT FROM AUTHOR]

Recently weakly-coupled mode-division multiplexing (MDM) transmission systems and networks based on ultralow-modal-crosstalk few-mode fiber (FMF) have attracted much interest, for which optical amplification technologies with low modal crosstalk and two-dimension mode-wavelength gain flattening are highly desired. In this paper, we propose for the first time a design method for few-mode Erbium-doped fiber (FM-EDF) with multi-ring-core (MRC) structures of both index and Erbium doping, which has high compatibility with the transmission MRC-FMF and low differential modal gain (DMG) with simple pump injection requirement. By sharing the boundaries of ring areas for both index and Erbium doping, the design method also helps to reduce the complexity of preform fabrication. We show by simulation that at 1550-nm signal wavelength, a 6-mode MRC-EDF can achieve a minimum DMG of 0.35-dB with only LP11 pump light injection and a 10-mode MRC-EDF can achieve a minimum DMG of 0.60-dB with LP01 and LP03 pump lights injection. Besides, the tolerance of DMG to the variation of fiber parameters induced by fabrication is analyzed. The proposed FM-EDF is beneficial for the practical applications of weakly-coupled MDM transmission systems and networks. [ABSTRACT FROM AUTHOR]

Pure shift techniques, as one of the rapidly developing frontiers in nuclear magnetic resonance (NMR) fields, can significantly enhance the resolution of NMR spectrum with a removal of splittings induced by scalar couplings. However, periodic artifacts due to residual scalar couplings during acquisition arise on all direct pure shift spectra, causing severe problems in analysis of complicated samples. Herein, we construct a signal model for the pure shift data and discuss the mechanism of periodic artifacts. Then, based on constraints on the low-rank property of pure shift NMR data, a subsequent artifact-suppression method is proposed to reconstruct a clean pure shift spectrum. With the proposed method, clean $^{\mathbf {1}}\text{H}$ pure shift spectrum can be obtained from only one experiment, greatly accelerating the experiment time while remaining the accuracy of the quantitative measurement. Experiments on a synthesis NMR signal, a complex sample of quinine with pseudo 2-D acquisition, and a medicine sample of azithromycin with 1-D acquisition are carried out to evaluate the feasibility and universality of the proposed method for different experimental techniques. Both the theoretical analysis and experimental results demonstrate the effectiveness of the proposed method for periodic artifacts suppression on complex samples and its potential for practical applications. [ABSTRACT FROM AUTHOR]

This article presents a novel triband dual-polarized shared-aperture antenna with frequency-selective function for sub-6 GHz base station applications. The proposed antenna is composed of a dual-polarized square loop antenna with two parasitic loops for 2G/3G/4G (1710–2690 MHz) and a differentially fed dual-polarized planar antenna for 5G (3300–3600 and 4800–5000 MHz) base station applications. These two antennas are placed coaxially but different altitudes for saving the installation space. In order to achieve good individual performance for these two antennas in the same aperture without interference or blocking, the lower band (LB) antenna is designed as a frequency-selective surface (FSS) for the nether mid/upper bands (M/UBs) antenna. The measured results show that the proposed antenna achieves a high port isolation (>20 dB) between LB and M/UBs and a −10-dB impedance bandwidth of 50.4% (1.60–2.70 GHz), 14.9% (3.28–3.80 GHz), and 8.6% (4.75–5.18 GHz). To further validate the design concept, an antenna array composed of four LB elements and eight M/UBs elements with the corresponding spacing is fabricated and measured, which demonstrates the application of the triband shared-aperture antenna in array form. [ABSTRACT FROM AUTHOR]

Due to the excellent electromagnetic properties of superconductor materials, superconducting generators have higher efficiency, lower weight and volume than traditional rotating machines. However, it is difficult to simulate the electromagnetic behavior in the superconducting generator due to the nonlinear E–J relationship. A numerical model based on the T–A formulation and moving mesh method is adopted to simulate the superconducting rotating machine, and the electromagnetic and mechanical behaviors of the superconducting rotating machine are investigated. The fully superconducting generator investigated in this article is radial type, which consists of field windings and armature windings made from YBa2Cu3O7−Δ (YBCO) superconducting race-track coils. The anisotropic field-dependent critical current density and the E–J power law relationship are considered in our model. The “virtual tape” model is introduced to calculate the induced current in the T–A formulation. The numerical results are obtained by the finite element method. The electromagnetic results calculated by our model are compared with results from the H–A formulation. The ac losses and stress distributions in superconducting coils are presented based on the T–A formulation. The results show that the body force and stress are periodic, and the stress will concentrate on the boundary of the coil. The magnetic field in the rotor is larger than that in the stator, and the field windings suffer greater body force and stress than the armature windings. This model has acceptable relative error with the H–A model for the time saved following T–A approach and relevance to mechanical calculations. Thus, this model can aid the design of superconducting rotating machines. [ABSTRACT FROM AUTHOR]

The control of heating, ventilation, and air-conditioning (HVAC) systems has raised extensive attention due to their high energy consumption cost and operation patterns far from being energy-efficient. However, most of the existing methods suffer limitations in scalability and computational efficiency for large buildings due to the centralized structures. To compensate for such defects, this article studies the scalable control of multizone HVAC systems with the target to reduce energy cost while maintaining thermal comfort. In particular, the thermal couplings due to heat transfer among the adjacent zones are incorporated, which has been ignored or not well studied due to complexity in the literature. To overcome the computational challenges of the nonlinear and nonconvex problem caused by the complex system dynamics, this article proposes a decentralized approach composed of three main steps: 1) relaxing the bilinear system dynamics; 2) solving the relaxed problem in a decentralized manner using the accelerated distributed augmented Lagrangian (ADAL) method; and 3) recovering the recursive feasibility of the solution. Through a comparison with the centralized method, the suboptimality of this approach is demonstrated. In addition, the superior performance of this approach is illustrated through a comparison with the distributed token-based scheduling strategy (DTBSS). The numerical results imply that for buildings with a relatively small number of zones (less than 20), the two methods are competitive. However, for larger cases, the proposed approach performs better with a considerable reduction both in energy cost and computation time. Note to Practitioners—This article develops a scalable computing framework for multizone HVAC controller, which can help reduce the electricity cost while maintaining the comfortable temperature bands set by the occupants. The proposed computing paradigm is scalable to large buildings as it mainly requires local zone-level computation. Specifically, for multizone buildings with a central shared HVAC system, the zone controllers determine the operations of their local variable air volume (VAV) boxes mainly through local computation and some necessary communications with the other entities. Consequently, this control technique can be implemented via local controllers deployed on simple hardware while applied to large buildings. The performance (electricity cost and computation time) of the controller is validated through a comparison with the centralized method and the DTBSS by using simulations. [ABSTRACT FROM AUTHOR]

This article addresses a new approach to investigating the impact of demand response (DR) on the generation adequacy by considering customers’ willingness to participate in DR. Firstly, to characterize psychological behaviors of the customer, we design a general reference-dependent utility (RU) function, and select the hyperbolic absolute risk aversion (HARA) function as the fundamental function to develop an HARA-RU (H-RU) function for depicting risk attitude of the customer. Secondly, a Q-learning algorithm based on the H-RU function is proposed to simulate customers’ willingness to participate in DR. In this way, the available capacity of DR can be measured. Thirdly, based on the available capacity, a DR scheduling model is developed. And fourthly, according to the scheduling results, an assessment procedure is proposed to evaluate the impact of DR on generation adequacy. Finally, a case study is provided to verify the effectiveness of our method. Besides, one limitation of this study is that transmission congestions are not considered. In future research, it would be interesting to consider this factor and extend our method to the case of a more sophisticated situation. [ABSTRACT FROM AUTHOR]

Recently optical amplification technologies for mode-division multiplexing (MDM) transmission systems and networks have attracted great interest. In this article, we first propose a compact structure of few-mode Erbium-doped fiber amplifier (FM-EDFA) for weakly-coupled MDM amplification, which is characterized by weakly-coupled few-mode Erbium-doped fiber (EDF), cascaded mode-selective couplers (MSCs) for spatial mode control of pump lights, and few-mode wavelength multiplexer (FM-WMUX) for pump/signal coupling. Compared to previous studies, the proposed FM-EDFA has a similar structure with commercial single-mode EDFA (SM-EDFA) and can support weakly-coupled MDM transmission without inducing large modal crosstalk. Then related components are designed and fabricated for a 2-mode proposed FM-EDFA. The mode-field mismatching between transmission FMF and EDF under central alignment is investigated by simulation. Thanks to the effective suppression of modal crosstalk for the optical components, the transmission FMF, the EDF and their coupling, we experimentally demonstrate the first weakly-coupled MDM-WDM amplification and transmission over 15-km 2-mode FMF with 10-Gb/s optical on-off keying (OOK) modulation and direct detection. The proposed FM-EDFA can be extended to MDM transmission systems and networks supporting more modes. [ABSTRACT FROM AUTHOR]

With the advantage of high surface-roughness tolerance, the pillar–concave Cu–Cu direct bonding without chemical-mechanical planarization (CMP) is investigated in detail, including the mechanism of thermal compensation, analysis of roughness, bonding strength, and bonding reliability. With the special design of Cu bond structure, excellent bonding results can be achieved under low thermal budget (150 °C for 1 min, atmosphere) with even high roughness of bonding surface. In addition, the pillar–concave scheme applied to fan-out panel-level package (FOPLP) has been demonstrated, showing the high feasibility of this scheme to realize applications in heterogeneous integration. [ABSTRACT FROM AUTHOR]

An optimized control approach for the distributed cooperative vehicular platoon was proposed in this paper, considering actuator delay and nonideal communication condition. A hierarchical structure is used to model the vehicular platoon, where the desired acceleration is optimized by CACC controller and the longitudinal tracking controller is proposed to follow it. In the design process of CACC controller, a parameter space approach and linear quadratic regulator (LQR) method are applied to guarantee the string stability and optimized performance. The influence of communication time delay and dropout rate is revealed by the changing of string stable region. Analytical results are verified by numerical simulations of a six-vehicle platoon where the leading vehicle follows the FTP-75 drive cycle speed profile. Furthermore, a Hardware-in-the-Loop (HIL) test is carried out with Carsim to simulate a high-fidelity vehicle dynamic model and dedicated short range communication (DSRC) modems as hardware in the loop as well as the control unit to achieve the inter-vehicle communication. The results show that the designed CACC platooning controller exhibits favorable performance in highway driving scenarios. The platooning vehicles display excellent car-following behavior with high accuracy, driving comfort and safety. [ABSTRACT FROM AUTHOR]

A wideband traveling-wave circularly polarized (CP) antenna printed on a single-layer PCB for millimeter-wave (MM-Wave) applications is presented in this communication. The proposed antenna radiates the CP wave on the basis of the principle similar to the classical endfire-mode helical antenna. The proposed antenna is terminated with an absorber to realize traveling-wave radiation. The traveling-wave working mechanism causes the proposed antenna to have a frequency scanning function and higher stability compared with resonant antennas. Curved microstrip transmission lines are adopted as the CP radiation elements; the whole array antenna is etched on a single-layer substrate. A prototype operating at 30 GHz is fabricated and measured. The radiation beam of the proposed antenna scans from − 14.5° (28 GHz) to +22.5° (34 GHz), the axial ratios are lower than 3 dB, and the measured gains show a maximum value of 21.9 dBi at 33 GHz and a minimum value of 20.3 dBi at 28 GHz. The measured $| \text {S}_{11} |$ and $| \text {S}_{21} |$ are lower than −10 and −16 dB, respectively, in the frequencies mentioned above. [ABSTRACT FROM AUTHOR]

We investigated high-order harmonic generation in molecules N2 and C6H6 irradiated by bichromatic counter-rotating circularly polarized laser pulses by using time-dependent density-functional theory methods. It is found that $3N$ ($N$ is an integer) order harmonics in C6H6 disappear. Whereas, $N$ order harmonics are obtained in N2. Analysis of the high harmonic generated from individual electronic orbital of the molecule, shows that, the characteristics of harmonic spectra are determined by the spatial distribution of electronic orbits. Moreover, effects of molecular orientation on harmonic emission are also presented. [ABSTRACT FROM AUTHOR]

In an uplink scenario, a base station can extract messages from multiple users through received symbols according to individual channel gains. There is a multiple access scheme relying on channel gains for separating users which is referred to as gain division multiple access (GDMA). Our goal is to provide channel estimation for the GDMA system without using pilot signals. We first employ a clustering technique to obtain estimates of the possible linear combinations of channel gains of users through a set of received symbols. We then devise algorithms to estimate the channel gain for each user and recover the message sent from each user. [ABSTRACT FROM AUTHOR]

A cooperative design of the advanced time-modulated array (TMA) and the retrodirective (RD) array is introduced to act as a transmitting array for multiuser wireless power transmission (WPT) applications. The conventional rectangular-pulse based TMA is lack of harmonic beamforming flexibility limited by its frequency spectral properties. By preprocessing the rectangular pulses with the sinusoid-based control signal, harmonic beams are independently steerable. The proposed array is enabled with self-phasing capability by taking advantage of the RD technique. Besides, to avoid the unexploited radiation caused by unscannable fundamental beam and specular harmonic beams, the single sideband (SSB) modulator is utilized to enable the transmitting array with high-efficiency beamforming capacity. The numerical results verify that the presented array performs well in various charging scenarios, which brings a highly potential insight for far-field WPT. [ABSTRACT FROM AUTHOR]

Increasing penetration of photovoltaic can cause high voltage variation that needs to be mitigated; this has been the focus of recent studies for many volt–ampere reactive (VAR) control strategies. Though voltage-variation mitigation is very important, it is also important to minimize power loss throughout the distribution when voltage variation is no longer an issue. Therefore, a complete adaptive sequential strategy for VAR control in distribution networks with solar energy is developed in this paper. In this adaptive sequential scheme, a two-way switch is designed to work with two operational modes: 1) voltage-variation minimization mode ($V\_{Mode}$) aimed to minimize voltage variations along the distribution network and 2) power-loss minimization mode ($P\_{Mode}$) aimed to minimize power loss. According to the operator needs for different situations, this two-way switch can be used to satisfy either the $V\_{Mode}$ or $P\_{Mode}$ requirements in a control loop fashion. Simulations are conducted with defined parameters in a radial distribution network. By comparing with no control (or baseline) in simulation, we show that the two-way switch works well in balancing the user needs (requirement) for the purpose of minimizing voltage variation and power loss in order to gain higher energy savings over a specified time duration. [ABSTRACT FROM AUTHOR]

An accurate power load estimation enables the controller to reduce the power loss and voltage fluctuation efficiently in the distribution grid. In this paper, we propose a mixed integer nonlinear program (MINLP) based power load estimator to detect and estimate the regular and unexpected abnormal loads with noise corrupted measurement in a photovoltaic-connected power distribution system. The power load data for different customers is from Southern California Edison. Unexpected abnormal power loads and measurement noise are simulated in several case studies to evaluate the accuracy and robustness of the power load estimators. The proposed new estimator solves an MINLP to detect abnormal power loads and accurately calculate their amplitudes. All parameters of this new estimator can be specified with clear guidelines, and its computational burden is not high. Finally, six different scenarios are presented to highlight the superiority of the proposed new estimator. [ABSTRACT FROM AUTHOR]

This paper develops a model predictive controller (MPC) via photovoltaic (PV)-based volt-ampere reactive scheme to minimize the power loss and stabilize voltage fluctuation when PV cells are connected to the power distribution line. The nominal power load data from California independent system operator is used to simulate dynamics of the system with DistFlow equations. Since power consumptions in fact may deviate from nominal values, an estimator is further developed to reconstruct the state variables and power loads from measurements. The integration of the MPC and estimator forms a closed-loop control framework and enables the system to quickly recover from undesired disturbances by effectively changing the real and reactive powers provided by PV cells. We use a bidirectional, single branch distribution circuit to demonstrate the performance of proposed scheme. The results show that our MPC indeed reduces power loss and keeps the voltage within a desired bound. Additionally, the estimator successfully detects and correctly estimates the abnormal change of power consumption and directs the MPC to compensate such unexpected power loads promptly. [ABSTRACT FROM AUTHOR]

This paper proposes two different control approaches to minimize the power loss subject to voltage constraints when photovoltaic (PV) cells are connected to the grid subject to abnormal (unexpected and extremely high) power loads. A dynamic load model is integrated with the DistFlow equations to describe the transient behavior of the real/reactive power, voltage, and loads. Based on this model, the proposed controllers utilize PV inverters to optimize performances of the grid by absorbing/injecting the reactive power. These controllers are particularly efficient to handle unexpected abnormal power loads. For demonstrations, a bidirectional, single branch distribution circuit with extremely high power load is used to test and compare our controllers with existing approaches, including the volt-ampere reactive control scheme specified by the IEEE Standard 1547 and adaptive method. The results show that our controllers indeed reduce the power loss compared with other methods and keep the voltage within the desired range. [ABSTRACT FROM AUTHOR]