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Grid connection of distributed generation would have a certain impact on safe and stable operation of receiving-end network, so systematic analysis on it would be significant. The method for comprehensive assessment on effects caused by grid connection of distributed generation on power grid is presented. The assessment system is divided into steady-state operation assessment, reliability assessment,...
In this work, we present a strategy for obtaining the dynamics of forest above-ground biomass (AGB) at a fine spatial and temporal resolution. Our strategy rests on the assumption that combining estimates of both AGB and carbon fluxes results in a more accurate accounting for biomass than considering only one of the terms since the cumulative carbon flux should be consistent with AGB increments. We...
Recently, multi-source remote sensing data and their derived features such as vegetation indices, texture metrics have been frequently applied to quantitatively estimate forest above-ground biomass (AGB). However, it is still challenging to efficiently select the optimal features for modeling the forest AGB. In this study, a fast, efficient and automatic method has been proposed, called as k-nearest...
Simulation of forest carbon fluxes over Greater Khingan based on strategy of model integration and data assimilation from 2000 to 2012 was conducted in this study. Original MODIS MOD_17 GPP (MOD_17) model was optimized over Greater Khingan using downscaled meteorological data, optimized light use efficiency, and refined GLASS fPAR products. Afterwards, representative forest plots for different forest...
This study investigated forest changes over Jinhe town of Inner Mongolia among 2001, 2004, 2008, 2013 and 2015 by use of multi-temporal Landsat Thematic Mapper-5 (TM), Chinese high resolution satellite data, Gaofen-1 (GF-1) remote sensing and forest inventory data. Vegetation fractional coverage (VFC) was extracted by the dimidiate pixel model. Forest above-ground biomass (AGB) was estimated by k-nearest...
In this study, we applied a process-based model, boreal ecosystem productivity simulator (BEPS) to simulate net primary productivity (NPP) over Fujian Province in 2015, and the responses of NPP to various environmental factors (e.g. temperature, elevation, slope, aspect) was analyzed. The results showed that: (1) the total NPP and mean NPP of Fujian province in 2015 are 43.13 × 106 tC and 540.75gC...
Anti-jamming is an important capability for satellite communication (SATCOM) systems, when critical communication links may need to be maintained in hostile environments with smart jammers trying to disrupt the communications. The protection of SATCOM links from intended radio frequency interference (RFI) is a complex task. Anti-jamming (AJ) can be done in multiple domains: space, time, frequency,...
Digital Beamforming (DB) in satellite communication (SATCOM) has drawn significant attention in recent years. DB design is flexible and adaptive among frequencies, bandwidths, and interferences. In this work, we design a cognitive radio testbed for SATCOM for digital beamforming design and implementation. The testbed is capable of simultaneously capturing signals from multiple antennas. Considering...
We report an integrated fiber-optic power meter by dip coating PbS colloidal quantum dots onto a pretreated specialty fiber. We measured the readout current at 1550nm as a function of the optical power, the bias voltage and the distance between the contact electrodes.
Synchronization plays an important role in wireless communication systems when tracking a phase-shift keying (PSK) signal, especially when the initial frequency error is comparable to the loop bandwidth. In order to improve frequency acquisition, an automatic frequency control (AFC) augmentation is used. This paper presents a composite AFC/Costas loop by combining both the AFC loop with a phase-locked...
Radio frequency interference (RFI) is ubiquitous in wireless communications which could greatly degrade communication system performances in an open environment. For satellite communications (SATCOM), the system performances degradation could be even worse considering the large round trip time (RTT) delay. To mitigate RFI effects, cognitive radio with adaptive waveform configurations could be effective...
This paper presents a novel approach for the uplink transmission power control for satellite communication (SATCOM) links that share a transponder's transmission power. The proposed approach provides explicit link margins (LM) for both uplinks and downlinks against losses from various sources that are uncertain in nature. The feature allows the proposed algorithm to work effectively with information...
Protected tactical waveform (PTW) provides cost-efficient, jamming-resistant communications via both government and commercial satellites over multiple frequency bands such as the C-, Ku-, Ka-, and X-band. Frequency hopping (FH) was originally developed for secure communications by exploiting time-frequency diversity over a large spectrum. The anti-jamming feature of the frequency hopping technique...
Forest vertical canopy cover (VCC) is an essential factor to be considered during forest resource inventory, sub-compartment division and thinning intensity. In order to monitor the forest canopy structure changes over the Greater Khingan, two temporal (2005 and 2010) forest VCC are derived by inverting the Li-Strahler geometric-optical model (GO) based on the extracted endmembers. The results show...
The quantification of forest Gross Primary Productivity (GPP) has been the focus of many scientific studies (e.g. carbon cycle, climate change, etc.). Current remote sensing-based models (i.e., the MODIS MOD_17 model), rely on the accurate meteorological data, specific vegetation parameter, the applicability and explicability of remote sensing data. In this study, the original MODIS GPP products were...
This study showed the potential for using Monte Carlo method for uncertainty analyses based on multi-parameter remote sensing data or incorporated models. The Monte Carlo method, involves using random numbers and probability to solve problems, is a simple but useful tool for uncertainty analyses with complex models. In this study, the uncertainties of the inter-annual and the overall forest AGB increments...
A strategy of data assimilation using the refined remote sensing product for the process-based model (Biome-BGC) in order to improve the simulated carbon fluxes was proposed. Firstly, we applied the optimized the remote-sensing-based MODIS MOD_17 GPP (MOD_17) model to calibrate the process-based Biome-BGC model. This incorporation strategy for the parameterization of Biome-BGC has been proved to be...
Forest is an important component of terrestrial ecosystems, so it is necessary to estimate the forest aboveground biomass (AGB) accurately in order to reduce the uncertainty of the carbon stock in forest ecosystem. In this study, a fast, efficient and automatic method has been proposed, called as Automatic KNN(AKNN). Using the Landsat 8 OLI data, airborne polmetric SAR (PolSAR) data, the AKNN has...
This study is to investigate the main operating mechanism of zinc oxide layer of ZnO RRAM (Resistance Random Access Memory). This experiment prepared four types of ZnO RRAM under different thermal annealing temperatures, Keithley 4200 measurement system was used to measure the operating voltage and current under a high impedance state and a low resistance state into the dielectric layer transmission...
Series battery equalization can improve battery charge and discharge reliability and extend battery life. It requires a higher requirement in battery management system (BMS). This paper introduces the high speed inductor-based battery equalization schemes. It can realize energy transfer between the cells and batteries by charging and discharging of the inductors. Thus the equalization time can be...
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