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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,341 papers · 148 categories

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190381571761 · Jun 202019922001200920182026
48 results for time variability

Proposes a method to allocate time budgets in mixed criticality systems.

problem Managing execution time variability in mixed criticality systems.
method Quantifies execution time variability using statistical dispersion parameters and proposes a heuristic to allocate time budgets.
result The proposed heuristic reduces the probability of exceeding allocated budgets.

TimeCNN improves forecasting by refining cross-variable interactions over time.

problem Multivariate time series forecasting struggles with dynamic and multifaceted cross-variable correlations.
method TimeCNN uses timepoint-independent convolution kernels to capture evolving relationships among variables.
result TimeCNN outperforms state-of-the-art models in real-world datasets with significant computational and speed advantages.

This paper enhances LSTM neural networks for multi-variable time series data, providing interpretable insights.

problem Accurate prediction of multi-variable time series data with interpretable insights.
method Variable-wise hidden states and a mixture attention mechanism to model the generative process of the target variable.
result Enhanced prediction performance by capturing the dynamics of different variables.

Proposes a multi-variable LSTM for accurate time series forecasting and variable importance.

problem Current attention mechanisms in recurrent neural networks fail to characterize variable importance in time series with exogenous variables.
method Develops a multi-variable LSTM with tensorized hidden states to learn variable importance and a mixture of temporal and variable attention.
result Demonstrates superior prediction performance and variable importance quantification compared to baselines.

LAVARNET predicts multivariate time series by estimating causal variable relationships.

problem Forecasting multivariate time series requires understanding causal interrelationships among variables.
method LAVARNET is a neural network architecture that estimates causal effects and predicts future values.
result LAVARNET outperforms other models on various real-world data sets.

Proposes an interpretable LSTM for time series with exogenous variables.

problem Lack of variable importance characterization in recurrent neural networks.
method Develops a multi-variable LSTM with tensorized hidden states for learning variable-specific representations.
result Variable attention in real datasets is highly aligned with statistical causality.

New method reconstructs missing variables in time series using autoencoders and automatic differentiation.

problem Reconstruct missing variables in time series with flexible input and output combinations.
method Train an autoencoder with all features, optimize missing variables as inputs, and use automatic differentiation.
result Flexible input and output combinations can be achieved without retraining the autoencoder.

Study on NNs for forecasting time series with novel control variable combinations.

problem Forecast future time series with novel combinations of control variables.
method Modular NN architecture with inductive bias for independence of control variables.
result Modular NN architecture improves forecasting of dependent variables up to large horizons.

Develops variable-lag Granger causality and Transfer Entropy for time series analysis.

problem Fixed time delay assumption in Granger causality and Transfer Entropy does not hold in many applications.
method Variable-lag Granger causality and Transfer Entropy, using optimal warping path of Dynamic Time Warping (DTW).
result Proposed methods perform better than existing methods in both simulated and real-world datasets.

Develops variable-lag Granger causality for more accurate time series analysis.

problem Fixed time delay assumption in Granger causality does not fit many real-world applications.
method Variable-lag Granger causality, inferring with arbitrary time delays.
result Performs better than existing methods in coordinated collective behavior studies.

New method learns differential equations from data with hidden variables.

problem Learning differential equations from data with hidden variables.
method Sparse linear regression optimization problem with higher order time derivatives and dictionary of functions.
result High quality short-term forecasts with orders of magnitude faster than competing methods.

Improved clustering speed for 20 clusters on CIFAR-100 dataset.

problem Training time complexity for VAEs with discrete latent variables is linear in the number of clusters.
method Applied a continuous relaxation to discrete variables in Gaussian Mixture VAE, reducing training time complexity to constant.
result Reduced training time from 47 hours to 6 hours for 20 clusters on CIFAR-100.

Paper proposes methods to discover causal models with unobserved variables.

problem Discovering causal relationships in data with unobserved variables.
method Two methods leveraging prior knowledge for causal discovery in CAM-UV models.
result Accuracy of causal discovery improves with more prior knowledge.

New method infers network couplings from spin trajectories in continuous time.

problem Inferring network couplings from observed spin trajectories in continuous time.
method Introducing latent variables to linearize and make likelihood quadratic, deriving EM and variational algorithms.
result Demonstrated performance on simulated data and biologically plausible network.

Properties of low-variability periods in the time series are analysed. The theoretical approach is used to show the relationship between the multi-scaling of low-variability periods and multi-affinity of the time series. It is shown that this technically simple method is capable of reveling more details about time-seri…

2004-06-09abs ↗pdf ↗

Study shows increased precipitation variability in Paris area over years.

problem Evaluating the evolution of precipitation variability over time.
method Shape-based Dynamic Time Warping (IMS-DTW) for clustering rainfall time series.
result Precipitation variability increased in Paris area over years.

Approach selects variables and time intervals for comparing high-dimensional time-series data.

problem Comparing high-dimensional time-series data for significant differences.
method Data is split into subintervals, and two-sample tests are performed on each to identify distinguishing variables.
result The approach effectively identifies variables and time intervals where data significantly differs.

The paper proposes a new model for predicting and analyzing economic variables.

problem Predicting and analyzing economic variables in developed regions.
method Time-varying parameter global vector autoregressive (TVP-GVAR) framework combined with machine learning models.
result The proposed model provides high precision out-of-sample predictions and novel insights into economic variable connectedness.

Proposes a method to reconcile count time series forecasts.

problem No formal framework for probabilistic reconciliation of count time series.
method Generalizes Bayes' rule for reconciling real-valued and count variables.
result Improves forecast accuracy for count variables compared to Gaussian reconciliation.

DynForest R package predicts outcomes with time-dependent predictors.

problem Handling time-dependent predictors in random forest models.
method Random forests with time-dependent predictors summarized using flexible linear mixed models.
result DynForest can predict continuous, categorical, and survival outcomes.

We generalize Ng's two-variable algebraic/combinatorial 00-th framed knot contact homology for framed oriented knots in S3S^3 to knots in S1×S2S^1 \times S^2, and prove that the resulting knot invariant is the same as the framed cord algebra of knots. Actually, our cord algebra has an extra variable, which potentially co…

2014-07-31abs ↗pdf ↗

Unsupervised method learns universal embeddings for variable-length multivariate time series.

problem Challenges in learning representations for time series data due to varying lengths and sparse labeling.
method Combines causal dilated convolutions with triplet loss for time-based negative sampling.
result Demonstrates quality, transferability, and practicability of learned representations.

New method identifies causes in time series with latent variables.

problem Identifying direct and indirect causes in time series data with hidden variables.
method Proves necessary and sufficient conditions for causal feature selection using graph constraints and conditional independence tests.
result Method outperforms Granger causality in identifying causes with low false positives and false negatives.

Paper tackles variable-length, incomplete wearable sensor data to improve personalized insights.

problem Variable-length and incomplete time series data from wearable sensors.
method HeartSpace integrates a time series encoding module and pattern aggregation network, along with a Siamese-triplet network for representation learning.
result Empirical evaluation shows significant performance gains in personality prediction, demographics inference, and user identification.

New method disentangles latent variables in nonstationary data.

problem Disentangling latent variables in nonstationary sequential data.
method NCTRL framework exploiting Markov assumption and temporal structure.
result Independent latent components can be recovered from nonlinear mixture without auxiliary variables.

Develops a Bayesian method for causal inference with partly censored time-to-event data.

problem Estimating causal effects with unobserved confounders and measurement errors in partly censored time-to-event data.
method Semiparametric Bayesian instrumental variable analysis using a two-stage Dirichlet process mixture model.
result The proposed method outperforms competing methods in simulations and real-world data analysis.

OracleAD detects multivariate time series anomalies without labels.

problem Rare and unlabeled multivariate time series anomalies.
method OracleAD encodes past sequences into causal embeddings, projects them into a latent space, and identifies anomalies based on deviations from a stable latent structure.
result OracleAD achieves state-of-the-art results and is interpretable.

New model preserves symmetry in multivariate time series, improving performance.

problem Implicit ordering in MTS models violates inherent exchangeability.
method Permutation-equivariant 2D state space model with canonical architecture.
result Eliminates sequential dependency chains and simplifies stability analysis.

Bayesian framework selects features and lags for time series forecasting.

problem Variable selection and lagged error term identification in time series models.
method Hierarchical Bayesian models with spike-and-slab priors, two-stage MCMC algorithm.
result Posterior selection consistency under mild conditions, improved predictive performance.

CDVAE estimates treatment effects over time by accounting for unobserved variables.

problem Estimating treatment effects over time in the presence of unobserved confounders.
method Causal Dynamic Variational Autoencoder (CDVAE) that addresses unconfoundedness and unobserved heterogeneity.
result CDVAE outperforms existing methods in estimating Conditional Average Treatment Effects (CATEs).

Spacetimeformer learns spatiotemporal relationships from data alone.

problem Forecasting multivariate time series with distinct spatial relationships.
method Transformers with dynamic graph connections learning interactions between space, time, and value.
result Competitive results on various time series prediction benchmarks.

We propose a new approach for properly analyzing stochastic time series by mapping the dynamics of time series fluctuations onto a suitable nonequilibrium surface-growth problem. In this framework, the fluctuation sampling time interval plays the role of time variable, whereas the physical time is treated as the analog…

2008-08-24abs ↗pdf ↗

New framework for tracking varying bounds in time series forecasting.

problem Forecasting bounded time series with varying bounds.
method Extended log-likelihood estimation, online maximum likelihood estimation, Normalized Gradient Descent (NGD) for quasiconvex optimization.
result Derive an Online Normalized Gradient Descent algorithm for online bound tracking.