Research
On-device research index

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.

169,181 papers · 148 categories

Trend · papers per month

1345 · Jun 202019922001200920182026
48 results for Bottom-Up

Bottom-up algorithms outperform top-down in hierarchical community detection at intermediate levels.

problem Finding the optimal hierarchical community structure in networks.
method A bottom-up algorithm for hierarchical clustering of networks.
result Bottom-up algorithms achieve the information-theoretic threshold for exact recovery at intermediate levels of the hierarchy.

BUSTLE synthesizes programs by learning from intermediate values.

problem Challenges in synthesizing complex programs due to large search space.
method Bottom-up search guided by a neural network trained on input-output examples.
result Bottom-up search with execution of intermediate programs provides valuable semantic information.

Efficient unsupervised training and inference in deep generative models remains a challenging problem. One basic approach, called Helmholtz machine, involves training a top-down directed generative model together with a bottom-up auxiliary model used for approximate inference. Recent results indicate that better genera…

2015-06-12abs ↗pdf ↗

CrossBeam learns to search more efficiently in program synthesis.

problem Efficiently searching through vast program spaces.
method Trains a neural model to guide program synthesis, combining previously explored programs.
result CrossBeam explores much smaller portions of the program space compared to state-of-the-art methods.

System designs for analyzing and pricing non-performing consumer credit portfolios.

problem Technical challenges in analyzing and pricing portfolios of non-performing consumer credit loans.
method Bottom-up architecture, simultaneous quantile regression, R-copula, Gaussian one-factor copula model.
result Successfully developed a methodology for analyzing credit portfolio risks of consumer loans.

Study improves forecasting of aggregated curves in electricity markets.

problem Improving accuracy in predicting aggregated curves like demand and supply in electricity markets.
method Exploits hierarchical structure of aggregated curves, uses reconciliation methods (bottom-up, top-down, linear optimal, aggregated-down).
result Hierarchical reconciliation methods can significantly improve forecast accuracy of aggregated curves.

We propose a novel adaptive approximation approach for test-time resource-constrained prediction. Given an input instance at test-time, a gating function identifies a prediction model for the input among a collection of models. Our objective is to minimize overall average cost without sacrificing accuracy. We learn gat…

2017-05-26abs ↗pdf ↗

We present a dynamic model selection approach for resource-constrained prediction. Given an input instance at test-time, a gating function identifies a prediction model for the input among a collection of models. Our objective is to minimize overall average cost without sacrificing accuracy. We learn gating and predict…

2017-04-25abs ↗pdf ↗

Multilayer bootstrap network builds a gradually narrowed multilayer nonlinear network from bottom up for unsupervised nonlinear dimensionality reduction. Each layer of the network is a nonparametric density estimator. It consists of a group of k-centroids clusterings. Each clustering randomly selects data points with r…

2014-08-05abs ↗pdf ↗

Study explores robust Orlicz spaces in finance, showing separability implications.

problem Understanding robustness in financial and economic contexts.
method Distinguished two constructions of robust Orlicz spaces: top-down and bottom-up.
result Separability of robust Orlicz spaces has strong implications for dominatedness and order completeness.

We introduce a new Bayesian model for hierarchical clustering based on a prior over trees called Kingman's coalescent. We develop novel greedy and sequential Monte Carlo inferences which operate in a bottom-up agglomerative fashion. We show experimentally the superiority of our algorithms over others, and demonstrate o…

2009-07-04abs ↗pdf ↗

A generative model is developed for deep (multi-layered) convolutional dictionary learning. A novel probabilistic pooling operation is integrated into the deep model, yielding efficient bottom-up (pretraining) and top-down (refinement) probabilistic learning. Experimental results demonstrate powerful capabilities of th…

2015-04-15abs ↗pdf ↗

We show that a generative random field model, which we call generative ConvNet, can be derived from the commonly used discriminative ConvNet, by assuming a ConvNet for multi-category classification and assuming one of the categories is a base category generated by a reference distribution. If we further assume that the…

2016-02-10abs ↗pdf ↗

In this paper, we propose a novel generative model named Stacked Generative Adversarial Networks (SGAN), which is trained to invert the hierarchical representations of a bottom-up discriminative network. Our model consists of a top-down stack of GANs, each learned to generate lower-level representations conditioned on …

2016-12-13abs ↗pdf ↗

A new multi-phase approach improves supply chain forecasting accuracy.

problem Improving forecast accuracy for hierarchical supply chain demands.
method Independent child-level forecasting followed by parent-level estimation.
result 82-90% improvement in forecast accuracy compared to traditional methods.

Efficiently learns linear non-Gaussian DAGs with noisy nodes.

problem Learning DAGs with non-Gaussian noise and diverging number of nodes.
method Proposes a novel method using topological layers for bottom-up reconstruction and consistent parent-child relations.
result Topological layers can be exactly reconstructed and parent-child relations established without faithfulness assumption.

Extends PCVM for multi-class classification with improved accuracy.

problem Lack of probabilistic outputs and contradictory predictions in multi-class classification.
method Proposes mPCVM with two learning algorithms: top-down and bottom-up.
result Superior performance, especially with many classes, validated on synthetic and benchmark data.

NFM improves deep learning by selectively processing hidden states.

problem Processing entire hidden states in each layer limits modularity and reusability.
method Introduces Neural Function Modules (NFM) with attention, sparsity, and feedback.
result Improves results in classification, generalization, generative modeling, and reinforcement learning.

BOinG optimizes HPO problems by focusing on promising local regions.

problem Expensive black-box optimization problems, especially hyperparameter optimization.
method Two-stage approach: global surrogate model followed by local model.
result BOinG exploits the structure of typical HPO problems and performs well on mid-sized problems.

Paper introduces TEP to better model treatment effect heterogeneity.

problem Personalised decision making requires evidence of treatment suitability.
method Designs TEP to represent treatment effect heterogeneity, uses local causal structure to show important variables, derives formula for unbiased CATE estimation.
result Proposed method models treatment effect heterogeneity better than existing methods.

The paper introduces a method to make neural networks more robust to adversarial attacks.

problem Vulnerability of deep neural networks to small, adversarially designed perturbations.
method A bottom-up strategy using a nonlinear front end that polarizes and quantizes data.
result The approach can completely eliminate adversarial perturbations on MNIST and Fashion MNIST datasets.

A generative Bayesian model is developed for deep (multi-layer) convolutional dictionary learning. A novel probabilistic pooling operation is integrated into the deep model, yielding efficient bottom-up and top-down probabilistic learning. After learning the deep convolutional dictionary, testing is implemented via dec…

2014-12-18abs ↗pdf ↗

Agent-based model uses SAM to create realistic economic system.

problem Lack of tools to understand and predict economic crises.
method Agent-based modeling (ABM) with Social Accounting Matrix (SAM) calibration.
result ABM can produce economic systems close to real-world data.

Deep neural networks blend mechanistic and phenomenological NLP approaches.

problem Combining theory-driven and data-driven NLP methods.
method Using deep neural networks to integrate mechanistic and phenomenological models.
result Deep learning can effectively model language and perception in spatial cognition.

Model learns collective and individual dynamics in time series data.

problem Lack of models capturing system-level collective behavior in individual time series.
method Hierarchical switching-state model with latent system-level and entity-level Markov chains.
result Model improves interpretability and forecasting accuracy compared to larger models.

New techniques reuse subword embeddings in neural models, reducing size and improving performance.

problem Improving performance and reducing model size in subword-aware neural language models.
method Reusing subword embeddings and other weights in multi-layer input embedding models, tying layers consecutively bottom-up.
result Best morpheme-aware model with reused weights outperforms competitive word-level model by a large margin.

We propose to prune a random forest (RF) for resource-constrained prediction. We first construct a RF and then prune it to optimize expected feature cost & accuracy. We pose pruning RFs as a novel 0-1 integer program with linear constraints that encourages feature re-use. We establish total unimodularity of the constra…

2016-06-16abs ↗pdf ↗

Novel ML approach optimizes large portfolios without covariance matrix issues.

problem Static and dynamic portfolio optimization for many assets.
method Machine learning for constrained optimization, avoiding covariance matrix computation.
result Significant excess returns in U.S. and China equity markets.

The traditional sparse modeling approach, when applied to inverse problems with large data such as images, essentially assumes a sparse model for small overlapping data patches. While producing state-of-the-art results, this methodology is suboptimal, as it does not attempt to model the entire global signal in any mean…

2017-02-11abs ↗pdf ↗