1,270 research outputs found
Characterization and electronic properties of moire superlattices in van der Waals heterostructures
SOC Estimation for Electrical Vehicle lithium Batteries base on Simplified-spherical Un-scented Kalman Filtering
In order to develop electric vehicles, it is vital to be able to accurately estimate the state charge (SOC) of a lithium battery. To address the problem that the Extended Kalman Filter (EKF) algorithm leads to the Taylor expansion truncation of the higher-order sys-tem. In this paper, a system of state-space equations is established based on the sec-ond-order equivalent circuit model, and a simplified-sphere sample approach is used to improve the Unscented Kalman Filter (UKF) algorithm. The SOC estimation performance of the three algorithms is tested under constant current discharge, pulse dis-charge con-ditions, and UDC conditions, respectively. The simulation results show that Simpli-fied-spherical Unscented Kalman Filtering (SUKF) has smaller errors between SOC esti-mation and theoretical reference values than EKF and UKF. The SUKF is less computa-tionally intensive than UKF and has better timeliness in the onboard battery manage-ment system
Enabling Cost-Effective Blockchain Applications via Workload-Adaptive Transaction Execution
As transaction fees skyrocket today, blockchains become increasingly
expensive, hurting their adoption in broader applications.
This work tackles the saving of transaction fees for economic blockchain
applications. The key insight is that other than the existing "default" mode to
execute application logic fully on-chain, i.e., in smart contracts, and in fine
granularity, i.e., user request per transaction, there are alternative
execution modes with advantages in cost-effectiveness.
On Ethereum, we propose a holistic middleware platform supporting flexible
and secure transaction executions, including off-chain states and batching of
user requests. Furthermore, we propose control-plane schemes to adapt the
execution mode to the current workload for optimal runtime cost.
We present a case study on the institutional accounts (e.g., coinbase.com)
intensively sending Ether on Ethereum blockchains. By collecting real-life
transactions, we construct workload benchmarks and show that our work saves 18%
~ 47% per invocation than the default baseline while introducing 1.81 ~ 16.59
blocks delay
PARADIGM TRANSFORMATION OF CRITICAL THINKING IN MARXIST PHILOSOPHY FROM THE PERSPECTIVE OF PSYCHOLOGY
PARADIGM TRANSFORMATION OF CRITICAL THINKING IN MARXIST PHILOSOPHY FROM THE PERSPECTIVE OF PSYCHOLOGY
Optimization Model and Pollution Treatment of Sintering Ore Distribution
sintering process plays an important role in iron and steel smelting process. The subsequent production of blast furnace ironmaking is directly affected by the quality of sinter. Among them, the proportion of raw materials and the advanced degree of sintering process are the two main factors affecting the quality of sinter. Because the control parameters of sintering process are too many and the physical and chemical process is too complex, it is difficult to establish and control the model accurately. Therefore, workers have long relied on experience to set temperature and other factors to engage in production, resulting in the quality of sinter is unstable, the cost is not easy to be controlled. Moreover, the flue gas produced in the sintering process will have different effects on the environment. Through the data analysis of the ore distribution scheme and the results of the physicochemical analysis of sinter in a steel plant, two aspects of the work are completed: one is to establish the optimal model of the cost of the sintering process, and the most suitable temperature for the sintering process. The second is the analysis of harmful components produced in sintering process
Water use efficiency of China\u27s terrestrial ecosystems and responses to drought
Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China’s terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg−1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. “Turning-points” were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity
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