New framework for sequential experiments with unknown data arrival.
problem Sequential decision-making with unknown information arrival.
method Generalized MAB framework for arbitrary arrival processes.
result Upper and lower bounds on minimax complexities.
We investigate asymmetry of information in the context of robust approach to pricing and hedging of financial derivatives. We consider two agents, one who only observes the stock prices and another with some additional information, and investigate when the pricing--hedging duality for the former extends to the latter. …
Modeling market dynamics with informed and uninformed traders and fads.
problem Optimizing market making in a market with fads, informed, and uninformed traders.
method Characterizing the optimal liquidity provision problem in a market with fads, informed, and uninformed traders, considering both complete and partial information.
result The price of liquidity is a function of the proportion of informed traders, and strategies ignoring fads underperform.
A learning-based algorithm optimizes admission control in a queuing system.
problem Optimizing admission decisions in a queuing system with unknown parameters.
method Proposes a learning-based dispatching algorithm to minimize regret compared to optimal policies.
result Achieves optimal regret bounds for different scenarios of unknown parameters.
Study examines how trading volumes and transactions affect stock volatility.
problem Understanding the impact of trading volumes and transactions on stock volatility.
method Used GARCH models to analyze daily stock data of the Tokyo Stock Exchange.
result GARCH effects are not always removed by adding trading volumes or transactions, suggesting they don't fully represent information arrivals.
Sequential screening and dynamic regret in multi-armed bandits with arriving arms
problem Sequential experimentation with expanding arm set
method UCB-AA with preliminary screening
result Regret bounds depend on arrival process
The paper presents a method for sound event localization and detection using CRNN models.
problem Sound event localization and detection in complex environments.
method Consecutive ensemble of CRNN models for estimating event onset, offset, direction of arrival, and classification.
result The proposed method outperforms other participants in the DCASE2019 task3.
The paper studies how expert opinions improve stock return predictions in a market with a hidden drift.
problem Improving stock return predictions in a market with a hidden Gaussian drift.
method Uses Kalman filter techniques to estimate the hidden drift from noisy expert opinions and stock returns.
result The Kalman filter estimates of the drift converge to the hidden drift as the frequency of expert opinions increases.
Model predicts stock returns from order arrivals and cancellations.
problem Forecasting intraday stock returns using limit order book dynamics.
method Microscopic model based on operator algebra for order arrivals and cancellations, estimating arrival and cancellation rate distributions.
result The model explains 80% of returns in in-sample forecasts and 15% in out-of-sample forecasts.
A multi-step framework tackles online unsupervised domain adaptation with novel mean-target subspace computation.
problem Online unsupervised domain adaptation with unlabelled target data arriving sequentially.
method Multi-step framework with a novel mean-target subspace computation and temporal coherency consideration.
result Improved performance over previous approaches on four datasets.
Tensor-based method simplifies causal skeleton discovery.
problem Discover causal relationships between variables.
method Express associations as tensors to reduce dimensionality.
result Causal skeleton can be determined using pair-wise tensors.
RNN models improve demand forecasting for diverse products.
problem Accurately predicting purchase patterns of popular products with sparse and heterogeneous data.
method Survival analysis with Recurrent Neural Networks (RNN) to model inter-arrival times and partially observed data.
result RNN-based approach achieves substantial improvements over traditional methods.
Space debris warnings follow a predictable pattern, allowing timely satellite maneuvers.
problem Estimating when fresh information about space debris will arrive.
method Statistical learning model of the message arrival process, specifically a Bayesian Poisson process.
result The average prediction error for the next message arrival time is smaller than baseline predictions.
We study how information perturbations can destabilize two-sided matching markets. In our model, agents arrive on the market over two periods, while agents in the first period do not know the types of those arriving later. Agents already present in the market may match early or wait for the small group of new entrants.…
Paper presents a neural network for estimating wavefronts in direction of arrival scenarios.
problem Estimating the number of wavefronts in direction of arrival scenarios.
method Cross-entropy trained multilayer neural network for online adaptation of antenna array imperfections.
result The method outperforms classical model order selection schemes in accuracy, especially at low signal-to-noise-ratios.
The paper optimizes portfolios in a market with hidden drift and random expert opinions.
problem Optimizing portfolios in a market with hidden Gaussian drift and random expert signals.
method Modeling the hidden drift using Kalman filters and solving the utility maximization problem with dynamic programming.
result Derivation of optimal portfolio weights and utility maximization under the given market conditions.
Study optimal trading strategies with expert signals in a hidden Gaussian drift market.
problem Optimal trading strategies in a financial market with hidden Gaussian drift and expert signals.
method Transformed power utility maximization problem into full information problem using Kalman filter estimates of the drift.
result Closed-form solutions for value function and optimal trading strategy derived.
Paper uses non-parametric methods to analyze stock price jumps triggered by news events.
problem Understanding how news events impact stock price jumps and pre-jumps.
method Non-parametric framework to examine intraday seasonality of news and jumps.
result Non-scheduled company announcements and macroeconomic announcements contribute to stock price jumps.
New model optimizes assortment and pricing with dynamic customer arrivals.
problem Suboptimal decisions in classical models due to fixed arrival rates.
method Poisson-MNL model with UCB algorithm for dynamic decisions.
result Efficient algorithm achieves near optimal cumulative revenue.
A limit order book provides information on available limit order prices and their volumes. Based on these quantities, we give an empirical result on the relationship between the bid-ask liquidity balance and trade sign and we show that liquidity balance on best bid/best ask is quite informative for predicting the futur…
Optimal algorithm selects biological models without prior info.
problem Determining the correct biological model without prior knowledge.
method Systems biology models and likelihood-free inference.
result Improved model selection performance over conventional methods.
Paper proposes a novel data augmentation method for neural networks in DOA estimation.
problem Improving neural network performance in Direction of Arrival (DOA) estimation.
method Applies a FOA-based transformation to input data and labels to simulate new DOA information.
result Improves DOA estimation error by around 40%.
Enhances causal estimation using unlabeled offline ICU data.
problem Assessing unmeasured physiological variables in new ICU patients.
method Three-stage approach: non-causal and causal estimators, causal filter, and prediction for new patients.
result Enhanced causal estimation for new ICU patients using offline data.
Algorithm solves job acceptance problem with random arrivals and values.
problem Decision-making under random job arrivals and values with limited acceptance.
method Proposes Non-Parametric Sequential Allocation (NPSA) algorithm.
result Expected reward converges to optimality as sample size increases.
Modeling financial markets with sandpile model to understand price volatility and arbitrage constraints.
problem Understanding price volatility and arbitrage constraints in financial markets.
method Uses a sandpile model to represent information and price changes, linking size of price volatility to the scaling law of avalanches.
result Identifies a structural tension between non-arbitrage condition and price adjustments consistent with a constant Sharpe ratio.
Proves Arnold-Thom conjecture for surfaces' arrival times.
problem Existence of limit tangents for gradient flow lines of surfaces.
method Gradient flow lines of mean curvature flows with neck or cylindrical singularities.
result Proves Arnold's conjecture for all mean convex mean curvature flows of surfaces.
The paper studies expert opinions in financial markets using diffusion approximations.
problem Estimating hidden drift in financial markets with expert opinions.
method Investigates asymptotic behavior of filter for high-frequency expert opinions, derives diffusion approximations.
result Expert opinions can be approximated by a diffusion process, simplifying utility maximization problems.
In this paper we propose a novel framework for decentralized, online learning by many learners. At each moment of time, an instance characterized by a certain context may arrive to each learner; based on the context, the learner can select one of its own actions (which gives a reward and provides information) or reques…
Simple connection between Harnack inequalities and concavity of arrival time functions.
problem Proving differential Harnack inequalities for various flows.
method Directly proving concavity properties of time-of-arrival functions for a class of flows using a concavity maximum principle.
result Short proof of Hamilton's and Andrews' differential Harnack inequalities.
DaringFed incentivizes clients in OFL with dynamic rewards under TII.
problem Designing incentives for OFL clients under dynamic, incomplete information.
method Formulated as a dynamic signaling and pricing allocation problem in a Bayesian persuasion game.
result Optimal design of DaringFed improves accuracy and convergence speed by 16.99%.
Modeling high-frequency order book data with Hawkes-Markovian process.
problem Capturing the dynamics of high-frequency order book events.
method Hawkes process with Markovian baseline intensities, LASSO regularization, and Akaike Information Criteria.
result Effective modeling of order book dynamics with reduced parameter redundancy.
Estimate arrival times in random recursive trees using iterated Jordan centralities.
problem Estimate arrival times in random recursive trees.
method Pointwise approach using iterated Jordan centralities.
result Tail bounds for relative estimation error.
Study improves queue length estimation from connected vehicles by filtering parameters.
problem Large errors in estimated queue lengths at low market penetration rates.
method Used Kalman and Particle filters as multilevel real-time estimators.
result Filters reduce estimation errors and improve accuracy within 15 minutes.
With the aid of concrete examples, we consider the question of whether, in the presence of conformal curvature, a conformal geodesic can become trapped in smaller and smaller sets, or phrased informally: are spirals possible? We do not arrive at a definitive answer, but we are able to find situations where this behavio…
We tackle the problem of collaborative filtering (CF) with side information, through the lens of Gaussian Process (GP) regression. Driven by the idea of using the kernel to explicitly model user-item similarities, we formulate the GP in a way that allows the incorporation of low-rank matrix factorisation, arriving at o…
Bayesian framework explains price formation with learning and market impact.
problem Understanding how prices form in markets with informed participants.
method Introduces a Bayesian model for updating priors on efficient prices.
result Exponential intensities for aggressive order arrivals are a natural outcome.
New model for multi-armed bandits with growing arms.
problem Balancing exploration and exploitation in a growing set of arms.
method Introduces Ballooning Multi-Armed Bandits (BL-MAB) and analyzes existing algorithms.
result Achieves sub-linear regret under certain conditions.
Estimates transaction arrival patterns in intraday electricity markets.
problem Estimating transaction arrival processes in intraday electricity markets.
method Model inter-arrivals using multiple time-varying parametric densities based on the generalized F distribution.
result Significant insights into model fit and prediction accuracy evaluated by various metrics.
Paper tackles online budgeted learning for feature acquisition in machine learning.
problem Finding optimal feature values to acquire from each instance in a data stream under budget constraints.
method Introduces a general framework for online budgeted learning, proposing two feature value acquisition policies: random and adaptive.
result Adaptive policies outperform random policies for most budget limitations and datasets, achieving near-optimal results in some cases.
This paper tackles inventory control with general arrival dynamics and post-processing, improving profitability.
problem Inventory control with arbitrary arrival dynamics and post-processing constraints.
method Formulated as an exogenous decision process, incorporating deep generative models for arrivals, and applying supervised learning techniques.
result Improves profitability over production baselines and real-world A/B test data.
New algorithm BE reduces regret in bandit learning with positive externalities.
problem Self-reinforcing user preferences in platforms lead to suboptimal performance in bandit learning.
method Developed Balanced Exploration (BE) algorithm and an adaptive variant.
result BE and adaptive BE achieve optimal asymptotic regret in bandit learning with positive externalities.
Cost-effective framework for eliciting and aggregating preferences.
problem Eliciting preferences efficiently under budget constraints.
method Iterative computation of cost-effective questions using Plackett-Luce model and various information criteria.
result Carefully designed information criteria lead to more accurate predictions with fewer questions.
A new method uses BSDEs to solve optimal reinsurance under partial information.
problem Maximizing wealth in insurance with partial loss information.
method Backward Stochastic Differential Equations (BSDEs) for infinite-dimensional filtering problem.
result Optimal reinsurance strategy found via BSDE solution.
High-frequency traders can act as either small informed traders or round-trippers, affecting price discovery and liquidity.
problem Effects of high-frequency trading on price discovery and liquidity.
method Extended Kyle's model with interactions between large informed traders and high-frequency traders.
result High-frequency traders can act as Small-IT or Round-Tripper, impacting price discovery and liquidity.
In this paper, we obtain the finite-horizon and infinite-horizon ruin probability asymptotics for risk processes with claims of subexponential tails for non-stationary arrival processes that satisfy a large deviation principle. As a result, the arrival process can be dependent, non-stationary and non-renewal. We give t…
Dynamic assortment problem on two-sided platform with unknown parameters
problem Optimizing assortment display in an online platform with incomplete information and heterogeneous customers
method Data-driven algorithm that learns choice parameters while optimizing revenue
result Worst-case regret grows polylogarithmically over time
Study models arrival rates and cancellation rates of limit orders in Borsa Istanbul.
problem Understanding order dynamics in Borsa Istanbul's stock market.
method Used limit order book data from Garanti Bank. Tested three discrete probability distributions and two theoretical models for arrival rates. Examined cancellation rates using L1 norms.
result Modelled daily, weekly, and monthly arrival rates of limit orders in the first fifteen bid and ask price levels.
Study on queues with Hawkes arrivals, proving steady-state behavior and developing an efficient algorithm.
problem Analyzing the steady-state behavior of queues with Hawkes arrivals.
method Novel coupling techniques and exponential convergence results for workload and busy period processes.
result Exponential convergence of queueing processes to their stationary distribution.