Ridge regression linked to Poisson resetting in statistical physics.
problem Understanding and extending ridge regularization in machine learning.
method Connecting stochastic resetting from statistical physics with ridge regularization in machine learning, using renewal processes.
result Exact filter identities for ridge regularization in various reset laws, including exponential and non-exponential.
The paper creates correlated Poisson processes from self-decomposable laws.
problem Creating non-independent Poisson processes with specific correlations.
method Using copulas and self-decomposable laws to pair exponential renewals.
result Explicit algorithms for applications in finance and queuing theory.
We consider the problem of finding the optimal time to sell a stock, subject to a fixed sales cost and an exponential discounting rate ρ. We assume that the price of the stock fluctuates according to the equation dY_t=Y_t(μdt+σξ(t) dt), where (ξ(t)) is an alternating Markov renewal process with values in {\pm1}, with a…
Unified framework for intermittent demand forecasting using renewal processes.
problem Intermittency in demand forecasting.
method Unified framework based on extensions of discrete-time renewal processes.
result Efficacy demonstrated in forecasting practice with favorable predictive accuracy.
The study analyzes a model for aggregate losses with dependent and overdispersed inter-losses times.
problem Analyzing aggregate loss models with dependent and overdispersed inter-losses times.
method The study uses a two-state Markovian arrival process (MAP2) and a Markov renewal process to model the inter-losses times. Severities are modeled using a heavy-tailed, double-Pareto Lognormal distribution. The model is estimated via direct maximization of the likelihood function.
result The model with dependence and overdispersion in inter-losses times leads to higher capital charges compared to a Poisson process.
Market activity scales near a constant of 0.632 in intrinsic time.
problem Understanding the stability of market scaling laws.
method Modeling market directional changes as a memoryless exponential hazard process and identifying the intrinsic time scaling constant.
result The intrinsic time scaling constant is 1−1/e=0.632. Study on error probability for classification of heavy-tailed renewal processes.
problem Error probability in classification of heavy-tailed renewal processes.
method Asymptotic expressions for Bhattacharyya bound on misclassification error probabilities.
result Obtained asymptotic expressions for misclassification error probabilities.
This paper proves exponential mixing for frame flows on hyperbolic manifolds with cusps.
problem Establishing exponential mixing for frame flows on geometrically finite hyperbolic manifolds with cusps.
method Symbolic coding of geodesic flow, Dolgopyat's method, large deviation property, combinatorics of cusp excursions, renewal theorem.
result Frame flows for geometrically finite hyperbolic manifolds of arbitrary dimensions are exponentially mixing.
This paper forecasts renewable energy prospects in South America through cross-border interconnection.
problem Lack of renewable energy integration across South American countries.
method Long-term scenario forecasting methodology applied to raw data from typical countries.
result Promoting cross-border interconnection towards renewables can optimize energy supply, reduce costs, and balance the energy matrix.
Develops framework for valuing and assessing risk of renewable PPAs.
problem Valuation and risk assessment of non-standard renewable PPAs.
method Formalizes payoff structures, derives fair contract prices, proposes market risk-assessment methodology.
result Fair prices and risk profiles vary across technologies and contractual structures.
Proposes a pricing agent using reinforcement learning to balance renewable energy demand.
problem Intermittent renewable energy sources challenge carbon-free electricity generation.
method Reinforcement learning approach to balance customer demand with renewable energy generation.
result Demonstrates improved electricity pricing strategy for renewable energy integration.
Characterizes measures preserving compound mixed renewal process properties.
problem Preserving compound mixed renewal process properties under different probability measures.
method Characterization of progressively equivalent probability measures.
result Any compound mixed renewal process can be converted into a compound mixed Poisson process through a change of measures.
Optimizes insurance renewal tariffs considering constraints and premium loadings.
problem Optimizing renewal tariffs under business and technical constraints.
method Mathematical and algorithmic approaches, including continuous and discrete optimization.
result Presented several sub-optimal algorithmic solutions and simulation techniques.
Study shows increased renewables lead to more extreme price spikes in balancing markets.
problem Higher variability of renewable energy leads to increased ancillary service costs, especially extreme price spikes.
method Agent-based modeling to simulate fluctuations in load and renewable energy production, forecasting resulting energy prices and costs.
result The probability of extreme price events increases with an increased share of renewable energy sources.
Paper develops framework for valuing and assessing credit risk in renewable PPAs.
problem Renewable PPAs expose both parties to counterparty credit risk.
method Modelled joint dynamics of electricity prices and renewable output, incorporated default probabilities.
result Provides transparent metric for PPA valuation under counterparty risk.
Optimizes renewable energy mix to meet carbon-free targets at lowest cost.
problem Minimizing annual procurement costs while achieving specified carbon-free hourly performance.
method Probabilistic framework with simulation scenarios and probability constraints. Fixed set of renewable generators and load customer.
result Demonstrated that certain renewable energy portfolios can meet carbon-free targets at lower costs compared to others.
In this paper we develop a symbolic technique to obtain asymptotic expressions for ruin probabilities and discounted penalty functions in renewal insurance risk models when the premium income depends on the present surplus of the insurance portfolio. The analysis is based on boundary problems for linear ordinary differ…
Boosted density estimation improves convergence guarantees without unrealistic assumptions.
problem Lack of formal convergence guarantees in density estimation methods.
method Introducing a weak learning assumption from boosting, we develop an iterative boosted density estimation algorithm.
result Formal convergence results with rates for density estimation without heavy assumptions.
Develops a semi-static strategy for hedging renewable PPAs, separating price and volume risks.
problem Risk exposure in pay-as-produced power purchase agreements (PPAs) due to joint power prices and renewable production.
method Uses a semi-static hedging strategy combining liquid futures for price risk and fixed renewable-linked claims for volume and covariance risk.
result Pricing and hedging of PPAs can be decomposed into a baseload forward level, a deterministic production-profile correction, and a stochastic price-volume covariance correction.
Model predicts sponsorship ROI using renewal probability.
problem Difficulty in measuring return on investment from sponsorships.
method Survival analysis using sponsorship renewal as proxy.
result Predicted values for sponsor's renewal probability and duration.
New models for analyzing microbiome data with interactions.
problem Analyzing compositional data with interactions.
method Exponential family models with generalized score matching.
result Effective estimation methods for compositional data with interactions.
Short-term probabilistic forecasting of German electricity imbalance prices.
problem Uncertainty in renewable energy capacity and electricity prices.
method Combining lasso with bootstrap, gamlss, and probabilistic neural networks for forecasting imbalance prices.
result Sophisticated methods improve empirical coverage of imbalance prices but do not substantially outperform the intraday continuous price index.
Modeling price formation in intraday electricity markets with renewable generation.
problem Price formation and optimal trading strategies in intraday electricity markets with intermittent renewable generation.
method Developed a tractable equilibrium model using stochastic control theory to identify optimal strategies and exhibit Nash equilibrium.
result Identified optimal trading strategies and exhibited Nash equilibrium in closed form for a finite number of agents and in the asymptotic framework of mean field games.
New random feature maps for Laplacian and related kernels.
problem Challenges in approximating the Laplacian kernel and its generalizations.
method Developed random feature maps for Laplacian and related kernels, providing efficient sampling schemes.
result Demonstrated the efficacy of these random feature maps on real datasets.
Federated learning calibrates insurance indices from renewable energy producers' data.
problem Calibrating parametric insurance indices under heterogeneous renewable energy production losses.
method Federated learning framework using Tweedie GLMs and distributed optimization.
result Federated learning recovers comparable index coefficients under moderate heterogeneity.
RMC uses renewal theory for online reinforcement learning with low variance and easy implementation.
problem Online reinforcement learning for infinite horizon Markov decision processes.
method RMC combines Monte Carlo methods with renewal theory to estimate performance gradients and update policies.
result RMC converges to locally optimal policies and can be generalized to post-decision state models.
Study warranty costs using alternating geometric process models.
problem Evaluate warranty servicing costs with varying repair times and product ages.
method Model repair and operational times using alternating geometric processes and derive new results for finite horizon.
result New insights into warranty costs under different warranty types.
Extends a model for limit order markets to more flexible distributions.
problem Modeling the dynamics of limit order markets with flexible distributions.
method Uses Markov renewal processes to model bid and ask queues, keeping analytical tractability.
result Calibrated model accurately represents market data for five stocks.
A new method uses Gaussian Processes to solve power flow problems with uncertain renewable and load inputs.
problem Solving power flow problems with uncertain renewable and load inputs.
method Non-parametric Bayesian inference-based uncertainty propagation using Gaussian Processes.
result The method provides reasonably accurate solutions with fewer samples and time compared to Monte-Carlo simulations.
Variable renewables can avoid market value decline with policy changes.
problem Market value decline due to correlated generation from wind and solar.
method Theoretical analysis and simulation examples of market incentives and prices.
result Market value decline is due to policy assumptions, not inherent technology limitations.
Develops a method for probabilistic simulation of renewable energy production at grid scale.
problem Uncertainty in short-term electricity generation from renewable assets.
method Probabilistic framework with asset calibration, hierarchical clustering, and Gaussianization.
result Full uncertainty quantification at asset and collection levels.
The paper analyzes MENA region's energy consumption and policy needs for renewable energy.
problem High dependency on oil and low renewable energy penetration in MENA region.
method Analysis of World Bank datasets and policy portfolio in MENA countries.
result MENA region has high potential for solar energy but faces challenges in decoupling economic growth from energy consumption.
Boosting improves trend detection in financial data.
problem Discovering trends in financial data during crises and recoveries.
method Extends boosting to higher order integrated processes and series with roots near unity.
result Boosting captures downturns and recoveries more accurately.
Framework for renewable energy forecasting and feature engineering.
problem Forecasting and feature extraction for multivariate processes in renewable energy.
method Derivative-free optimization, ensemble of sequence-to-sequence networks, additive resampling, Bootstrap aggregating.
result The proposed method outperforms other machine learning techniques in long-term forecasts and feature selection.
Paper develops deep models for forecasting intermittent demand.
problem Forecasting intermittent demand with sporadic occurrences.
method Uses deep neural networks to model conditional interdemand time and size distributions.
result Empirical validation of deep models for intermittent demand forecasting.
Enhances renewable energy forecasts and trading profits.
problem Improving accuracy and economic benefits of renewable energy forecasts and trading.
method Data-driven newsvendor model using features from multiple sources.
result Significant reduction in balancing costs and improvement in forecast accuracy.
Bayesian GAN generates diverse renewable scenarios efficiently.
problem Generating diverse and accurate renewable energy scenarios.
method Bayesian GAN, a deep neural network approach.
result Generates clusters of wind and solar scenarios with different variance and mean values.
Hybrid AI methods optimize renewable energy and facilities management.
problem Optimizing renewable energy resources and facilities management in oceanic engineering and airports.
method Hybrid neuro-evolutionary algorithms and machine learning.
result Proposed methodologies for predicting key parameters in renewable energy and facilities management.
Proposes a model to update industrial data predictions based on temporal changes.
problem Improving prediction accuracy in industrial data analytics by addressing changing conditions over time.
method Integrates similarity and loss functions to estimate and update prediction models adaptively.
result The data renewal model enhances prediction accuracy by identifying and updating model changes.
We briefly review our recent studies on stochastic processes modelling internet on-line trading. We present a way to evaluate the average waiting time between the observation of the price in financial markets and the next price change, especially in an on-line foreign exchange trading service for individual customers v…
Fossil power firms have recently profited more than renewables, but this may be a temporary phenomenon.
problem The profitability gap between renewable and fossil power firms in Europe.
method Machine-learning clustering and Bayesian model averaging.
result Renewable power firms are becoming more profitable, while fossil power firms are becoming less so.
We analyze the data of the Italian and U.S. futures on the stock markets and we test the validity of the Continuous Time Random Walk assumption for the survival probability of the returns time series via a renewal aging experiment. We also study the survival probability of returns sign and apply a coarse graining proce…
Paper studies second order tail probabilities in risk models.
problem Analyzing tail probabilities in risk models with constant interest force.
method Asymptotic expansion and weighted Kesten-type inequality for second order subexponential random variables.
result Second order asymptotic formulae for continuous-time renewal risk models are derived.
Paper uses Gaussian processes to solve AC-OPF with renewable uncertainty.
problem Optimizing power grids with fluctuating renewable sources.
method Data-driven approach using Gaussian processes.
result Efficiently solves chance-constrained AC-OPF with uncertainty.
Modeling stock order book dynamics with bouncing GBMs.
problem Capturing the dynamics of order book prices in financial markets.
method Modeling order book bid and ask prices as bouncing geometric Brownian motions.
result The logarithmic trading price process converges to a standard Brownian motion as δ approaches 0.
Paper designs efficient data compression and MAC protocol for smartgrids.
problem Efficiently compress and transmit data from smartgrids with renewable energy.
method Uses compressed sensing (CS) for data compression and adapts 802.15.4 MAC protocol for reliable transmission.
result Minimizes reporting delay and ensures reliable data reconstruction.
A model is presented in this work for simulating endogenously the evolution of the marginal costs of production of energy carriers from non-renewable resources, their consumption, depletion pathways and timescales. Such marginal costs can be used to simulate the long term average price formation of energy commodities. …
Alternative proof for ribbon surfaces in 3D space.
problem Proving ribbonness of surfaces in 3D space.
method Using a compact oriented proper surface in upper half 4-space.
result Link bounds a ribbon surface in upper half 4-space.