Publications by Jiannong Fang | EPFL Graph Search

Improving the accuracy and interpretability of neural networks for wind power forecasting

Jiannong Fang, Fernando Porté Agel, Wenlong Liao

Deep neural networks (DNNs) are receiving increasing attention in wind power forecasting due to their ability to effectively capture complex patterns in wind data. However, their forecast errors are severely limited by the local optimal weight issue in opt ...

2025

Explainable modeling for wind power forecasting: A Glass-Box model with high accuracy

Jiannong Fang, Fernando Porté Agel, Wenlong Liao

Machine learning models (e.g., neural networks) achieve high accuracy in wind power forecasting, but they are usually regarded as black boxes that lack interpretability. To address this issue, the paper proposes a glass-box model that combines high accurac ...

2025

TimeGPT in load forecasting: A large time series model perspective

Jiannong Fang, Fernando Porté Agel, Wenlong Liao

Machine learning models have made significant progress in load forecasting, but their forecast accuracy is limited in cases where historical load data is scarce. Inspired by the outstanding performance of large language models (LLMs) in computer vision and ...

2025

Can we trust explainable artificial intelligence in wind power forecasting?

Jiannong Fang, Fernando Porté Agel, Wenlong Liao

Advanced artificial intelligence (AI) models typically achieve high accuracy in wind power forecasting, but their internal mechanisms lack interpretability, which undermines user confidence in forecast value and strategy execution. To this end, this paper ...

Elsevier BV2024

Evolution of Turbulent Boundary Conditions on the Surface of Large Barchan Dunes: Anomalies in Aerodynamic Roughness and Shear Velocity, Aeolian Threshold, and the Role of Dune Skewness

Jiannong Fang, Fernando Porté Agel

We recorded aerodynamic roughness and shear velocity along transects on and around mature crescent‐shaped barchan dunes of and height above the horizontal rock‐covered Qatar desert by fitting to the log‐law time‐averaged vertical velocity profiles acquir ...

American Geophysical Union (AGU)2024

A Fast Hybrid Pressure-Correction Algorithm for Simulating Incompressible Flows by Projection Methods

Jiannong Fang

To enforce the conservation of mass principle, a pressure Poisson equation arises in the numerical solution of incompressible fluid flow using the pressure-based segregated algorithms such as projection methods. For unsteady flows, the pressure Poisson equ ...

2023

Numerical Weather Prediction and Artificial Neural Network Coupling for Wind Energy Forecast

Jiannong Fang, Fernando Porté Agel, Lorenzo Donadio

In the past two decades, wind energy has been under fast development worldwide. The dramatic increase of wind power penetration in electricity production has posed a big challenge to grid integration due to the high uncertainty of wind power. Accurate real ...

2021

Wind Energy Prediction in Highly Complex Terrain by Computational Fluid Dynamics

Jiannong Fang, Fernando Porté Agel, Daniel Jacob Tabas

With rising levels of wind power penetration in global electricity production, the relevance of wind power prediction is growing. More accurate forecasts reduce the required total amount of energy reserve capacity needed to ensure grid reliability and the ...

2019

Shifts in wind energy potential following land-use driven vegetation dynamics in complex terrain

François Golay, Jiannong Fang, Alexandre Buttler, Fernando Porté Agel, Alexander Ludwig Johannes Peringer

Many mountainous regions with high wind energy potential are characterized by multi-scale variabilities of vegetation in both spatial and time dimensions, which strongly affect the spatial distribution of wind resource and its time evolution. To this end, ...

2018

Katabatic Flow: A Closed-Form Solution with Spatially-Varying Eddy Diffusivities

Peter Monkewitz, Jiannong Fang, Marc Parlange, Marco Giovanni Giometto

The Nieuwstadt closed-form solution for the stationary Ekman layer is generalized for katabatic flows within the conceptual framework of the Prandtl model. The proposed solution is valid for spatially-varying eddy viscosity and diffusivity (O'Brien type) a ...

Springer Verlag2017

Direct numberical simulation of turbulent slope flows up to Grash of number Gr=2.1 x 10(11)

Jiannong Fang, Marc Parlange, Marco Giovanni Giometto, Gabriel George Katul

Stably stratified turbulent flows over an unbounded, smooth, planar sloping surface at high Grashof numbers are examined using direct numerical simulations ( DNS). Four sloping angles ( alpha = 15 degrees; 30 degrees; 60 degrees and 90 degrees) and three G ...

Cambridge University Press2017

Spatial Characteristics of Roughness Sublayer Mean Flow and Turbulence Over a Realistic Urban Surface

Jiannong Fang, Marc Parlange, Marco Giovanni Giometto, Charles Vivant Ignacio Meneveau

Single-point measurements from towers in cities cannot properly quantify the impact of all terms in the turbulent kinetic energy (TKE) budget and are often not representative of horizontally-averaged quantities over the entire urban domain. A series of lar ...

Springer2016

Intercomparison of Terrain-Following Coordinate Transformation and Immersed Boundary Methods for Large-Eddy Simulation of Wind Fields over Complex Terrain

Jiannong Fang, Fernando Porté Agel

Accurate modeling of complex terrain, especially steep terrain, in the simulation of wind fields remains a challenge. It is well known that the terrain-following coordinate transformation method (TFCT) generally used in atmospheric flow simulations is rest ...

2016

Study of chi(cJ) decaying into phi K*(892)(K)over-bar

François Bianchi, Jun Dong, Jiannong Fang, Hua Zhang, Mingkui Wang, Fang Liu, Yixing Chen, Shan Jin, Xiaoqing Zhou, Yuan Yuan, Fengping Li, Qian Wang, Lei Zhou, Sofia Carmen Suzanne Spataro, Zhirui Xu, Lin Yang, Ke Liu, Yu Zheng, Siyuan Wang, Junqiu Liu, Yi Zhang, Jianing Li, Lei Zhang, Yong Yang, Hao Liu, Jian Liu, Yang Qin, Feng Liu, Xuan Li, Lei Li, Kun Liu, Cheng Li, Xiao Wang, Yi Wang, Xin Chen, Wei Li, Jie Chen, Yifei Guo, Shuai Liu, Zheng Wang, Qianyu Zhao

Using a data sample of 106 million psi(3686) events collected with the BESIII detector operated at the BEPCII storage ring, we study for the first time the decays chi(cJ) -> phi(KSK +/-)-K-0 pi(-/+) and chi(cJ) -> phi K+K-pi(0) in the E1 radiative transiti ...

2015

Large-Eddy Simulation of Very-Large-Scale Motions in the Neutrally Stratified Atmospheric Boundary Layer

Jiannong Fang, Fernando Porté Agel

Large-eddy simulation is used to investigate very-large-scale motions (VLSMs) in the neutrally stratified atmospheric boundary layer at a very high friction Reynolds number, . The vertical height of the computational domain is m, which corresponds to the t ...

Springer Verlag2015

Parallelization of the distinct lattice spring model

Jiannong Fang, Jian Zhao, Gaofeng Zhao, Liang Sun

The distinct lattice spring model (DLSM) is a newly developed numerical tool for modeling rock dynamics problems, i.e. dynamic failure and wave propagation. In this paper, parallelization of DLSM is presented. With the development of parallel computing tec ...

Wiley-Blackwell2013

Flow over Hills: A Large-Eddy Simulation of the Bolund Case

Jiannong Fang, Marc Diebold, Marc Parlange, Chad Higgins

Simulation of local atmospheric flows around complex topography is important for several applications in wind energy (short-term wind forecasting and turbine siting and control), local weather prediction in mountainous regions and avalanche risk assessment ...

Springer Verlag2013

A MLS-based lattice spring model for simulating elasticity of materials

Jiannong Fang, Jian Zhao, Gaofeng Zhao

A MLS-based lattice spring model is presented for numerical modeling of elasticity of materials. In the model, shear springs between particles are introduced in addition to normal springs. However, the unknowns contain only particle displacements but no pa ...

World Scientific Publ Co Pte Ltd2012

A coupled distinct lattice spring model for rock failure under dynamic loads

Jiannong Fang, Jian Zhao, Gaofeng Zhao

It is necessary to take into account the micro discretization of natural rock when studying its macroscopic failure behavior. This requirement has resulted in renewed and increased interest in the discrete or framework/lattice numerical modeling techniques ...

Elsevier2012

Towards oscillation-free implementation of the immersed boundary method with spectral-like methods

Jiannong Fang, Marc Diebold, Marc Parlange, Chad Higgins

It is known that, when the immersed boundary method (IBM) is implemented within spectral-like methods, the Gibbs oscillation seriously deteriorates the calculation of derivatives near the body surface. In this paper, a radial basis function (RBF) based smo ...

Elsevier2011