Exploiting the increasingly wide use of Light-emitting Diode (LED) lighting, in this paper, we study problem using visible LED lights for accurate localization. The basic idea is to leverage existing lighting infrastructure and apply trilateration localize any devices with light sensing capability (e.g., a smartphone), lamps as anchors. Through design Epsilon, identify tackle several technique challenges. In particular, establish experimentally verify optical channel model We adopt BFSK...

In this paper, we look at making backscatter practical for ultra-low power on-body sensors by leveraging radios on existing smartphones and wearables (e.g. WiFi Bluetooth). The difficulty lies in the fact that order to extract weak backscattered signal, system needs deal with self-interference from wireless carrier (WiFi or Bluetooth) without relying built-in capability cancel reject interference.

Modern mobile networks are facing unprecedented growth in demand due to a new class of traffic from Internet Things (IoT) devices such as smart wearables and autonomous cars. Future must schedule delay-tolerant software updates, data backup, other transfers IoT while maintaining strict service guarantees for conventional real-time applications voice-calling video. This problem is extremely challenging because highly dynamic across space time, so its performance significantly impacted if all...

The grid-forming and grid-following controls are adopted in three-phase voltage source converters according to different grid conditions. However, the basic operation principle of two kinds control is will lead instability grid-connected system through various paths. In this article, energy function model controlled established compared detail. influence parameters studied, large-signal stability boundaries derived a general method. Moreover, converter, converter lose by exhibiting varying...

Backscatter provides dual-benefits of energy harvesting and low-power communication, making it attractive to a broad class wireless sensors. But the design protocol that enables extremely power-efficient radios for harvesting-based sensors as well high-rate data transfer data-rich presents conundrum. In this paper, we present new {\em fully asymmetric} backscatter communication where nodes blindly transmit when they sense. This model flexible node designs, from extraordinarily consume barely...

Monitoring of droughts is the first step into human adaptation and related management drought hazards. Therefore, index critical in monitoring practice. However, standing indices include no information about agricultural irrigation. In this case, based on Palmer Drought Severity Index (PDSI) Self-Calibrating (sc-PDSI), here we proposed Modified (MPDSI) by considering irrigation such as quotas soil water deficits. We compared changes monitored MPDSI other considered study, found that can well...

This paper argues for a clean-slate redesign of wireless sensor systems to take advantage the extremely low power consumption backscatter communication and emerging ultra-low modalities. We make case that existing sensing architectures incur substantial overhead variety computational blocks between RF front end - while these overheads were negligible on platforms where was expensive, they become bottleneck backscatter-based increase limiting throughput. present radically new design is...

While many radio technologies are available for mobile devices, none of them designed to deal with asymmetric energy. Battery capacities devices vary by up three orders magnitude between laptops and wearables, our inability such asymmetry has limited the lifetime constrained portable devices.

Indoor physical analytics calls for high-accuracy localization that existing indoor (e.g., WiFi-based) systems may not offer. By exploiting the ever increasingly wider adoption of LED lighting, in this paper, we study problem using visible lights accurate localization. We identify key challenges and tackle them through design Pharos. In particular, establish experimentally verify an optical channel model suitable adopt BFSK hopping to achieve reliable location beaconing from multiple,...

Different battery chemistries perform better on different axes, such as energy density, cost, peak power, recharge time, longevity, and efficiency. Mobile system designers are constrained by existing technology, forced to select a single chemistry that best meets their diverse needs, thereby compromising other desirable features. In this paper, we present new hardware-software system, called Software Defined Battery (SDB), which allows integrate batteries of chemistries. SDB exposes APIs the...

Backscatter provides dual-benefits of energy harvesting and low-power communication, making it attractive to a broad class wireless sensors. But the design protocol that enables extremely power-efficient radios for harvesting-based sensors as well high-rate data transfer data-rich presents conundrum. In this paper, we present new fully asymmetric backscatter communication where nodes blindly transmit when they sense. This model flexible node designs, from extraordinarily consume barely few...

One of the central challenges in backscatter is how to enable concurrent transmissions. Most protocols operate a sequential TDMA-like manner due fact that most nodes cannot overhear each other's transmissions, which detrimental for throughout and energy consumption. Recent efforts separate signals by inverting system linear equations also problematic varying channel coefficients caused environmental dynamics. In this paper, we introduce BST, novel physical layer communication enables...

The power electronics' penetration in modern grids is rapidly increasing due to the growing proportion of renewable energy generation. As important conversion interface, stable operation grid-tied converters vital overall safe double-high system. prior arts have mainly focused on varying negative damping phase-locked loop (PLL). Negative imposes into system and detrimental system's transient stability should not be neglected as constant positive synchronous generators. deficiencies previous...

In this paper, an optimal transient control (OTC) scheme is proposed to improve the stability of grid-forming (GFM) wind farm (WF) based on WTs. The converter’s current operating safety range considered quantify maximum KES capabilities At WF level, global voltage problem solved by optimizing output reactive power different WTs WF. WT improved regulating and weak magnetic current. simulation results in MATLAB/Simulink show that can more efficiently suppressing DC bus fluctuations enhancing...

Abstract Extreme sea levels (ESLs) due to typhoon-induced storm surge threaten the societal security of densely populated coastal China. Uncertainty in extreme value analysis (EVA) for ESL estimation has large implications communities’ adaptation natural hazards. Here we evaluate uncertainties and relevant driving factors based on hourly observations from 13 tide gauge stations a complementary dataset derived hydrodynamic model. Results indicate significant estimations stemming using...

With continuous increase of penetration renewable energies and power electronic equipment, grid stability incidents are emerging frequently worldwide. In this article, the transient assessment dominated systems with multiple PLL-based voltage source converters (VSCs) is studied by calculating critical clearing time (CCT). A tangent hyperplane method developed, which approximates boundary basin attraction near unstable equilibrium point linear system theory. The detailed algorithm presented,...

Control strategy of the AC/DC bi-directional converter(ADBC) in hybrid microgrid plays a crucial role for stable operation and power distribution whole microgrid. A novel ADBC control is proposed this paper. In grid-connected mode, adopts improved droop to maintain DC bus voltage, which ensures maximum efficiency renewable energy islanding adopting rational allocation between AC microgrid, improving stability system. The both reduces loss two modes. And same structure applied modes avoids...

In order to solve the problem of vulnerability assessment complex power systems facing structures and large sizes, a novel data driven method based on random matrix theory is proposed in this paper. Firstly, with use phasor measurement units (PMUs) big data, evaluation matrices are constructed extract statistical characteristics operation. Then, combination entropy theory, index considering degree influence some faults systems. With full model-free more accurate comprehensive. Simulation...

One of the central challenges in backscatter is how to enable concurrent transmissions. Most protocols operate a sequential TDMA-like manner due fact that most nodes cannot overhear each other's transmissions, which detrimental for throughout and energy consumption. Recent efforts separate signals by inverting system linear equations also problematic varying channel coefficients caused environmental dynamics. In this paper, we introduce BST, novel physical layer communication enables...

The demand for decarbonization calls building up a nearly 100% renewable electricity resulting in Grid-forming (GFM) capability requirements. foregoing paradigm shifts from synchronous AC systems to converter-based that need remain stable and self-synchronous while providing GFM services. However, as this article’s analysis the introduction, achieving such goals inevitably necessitates implementation of PLL controller energy storage wind turbine, whereas it is not suitable operate weak...