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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.

168,694 papers · 148 categories

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111221332442 · Jun 202019922001200920172026
48 results for LR fuzzy numbers

In the study of investment problem, aside from the investment risk the background risk appears. Both the investment risk and the background risk are probabilistically described by random variables. This paper starts from the hypothesis that the two types of risk can be represented both probabilistically (by random vari…

2018-12-08abs ↗pdf ↗

Enhanced fuzzy system predicts chaotic time series with improved accuracy.

problem Forecasting chaotic time series with high uncertainty.
method Combines evolving fuzzy systems, participatory learning, KRLS, and type-2 fuzzy sets.
result Proposed model outperforms other methods in accuracy and complexity.

Cluster analysis is widely used in the areas of machine learning and data mining. Fuzzy clustering is a particular method that considers that a data point can belong to more than one cluster. Fuzzy clustering helps obtain flexible clusters, as needed in such applications as text categorization. The performance of a clu…

2018-06-05abs ↗pdf ↗

New validity index for fuzzy-possibilistic c-means clustering.

problem Conflicting results in determining the optimal number of clusters due to noisy data points and outliers.
method Introducing a new validity index (FP index) for fuzzy-possibilistic c-means clustering.
result FP index works well in datasets with varying cluster shapes and densities.

SESSC clusters fuzzy rules for TSK classifiers, improving performance with label info.

problem Lack of supervised clustering for TSK fuzzy classifiers.
method SESSC integrates within-cluster compactness, between-cluster separation, and label information.
result SESSC initialization outperforms other clustering methods, especially for small rule numbers.

New cluster validity index detects optimal number of clusters and secondary options.

problem Determining the optimal number of clusters in fuzzy clustering.
method Correlation-based fuzzy cluster validity index (WP index) using fuzzy c-means algorithm.
result WP index outperforms existing indexes in detecting optimal number of clusters and secondary options.

An LR-structure on a Lie algebra is a bilinear product, satisfying certain commutativity relations, and which is compatible with the Lie product. LR-structures arise in the study of simply transitive affine actions on Lie groups. In particular one is interested in the question which Lie algebras admit a complete LR-str…

2009-06-05abs ↗pdf ↗

The expected utility operators introduced in a previous paper, offer a framework for a general risk aversion theory, in which risk is modelled by a fuzzy number AA. In this paper we formulate a coinsurance problem in the possibilistic setting defined by an expected utility operator TT. Some properties of the optimal …

2019-08-13abs ↗pdf ↗

The fuzzy ROC extends Receiver Operating Curve (ROC) visualization to the situation where some data points, falling in an indeterminacy region, are not classified. It addresses two challenges: definition of sensitivity and specificity bounds under indeterminacy; and visual summarization of the large number of possibili…

2019-03-04abs ↗pdf ↗

Large learning rates lead to optimal generalization if chosen carefully.

problem Understanding the optimal range of large learning rates for neural network training.
method Empirical study focusing on two questions: optimal initial LR range and differences between models trained with different LRs.
result Optimal initial learning rates slightly above the convergence threshold lead to optimal results after fine-tuning with a small LR or weight averaging.

CAF-HFCM automatically forms a cluster hierarchy and optimizes the number of clusters without trial-and-validation.

problem Challenges in determining the optimal number of clusters in fuzzy c-means.
method CAF-HFCM, an auto-fused hierarchical fuzzy c-means method.
result Automatic agglomeration and optimal number of clusters without validity indices.

Proposes a conservative LR estimator for infrequent data near a frequency threshold.

problem Overestimation of likelihood ratios for infrequent data near a frequency threshold.
method Conservative likelihood ratio estimator for frequencies slightly above a threshold.
result Improves prediction accuracy in named entity context prediction.

In this paper, we have tried to apply the concepts of fuzzy sets to Lie groups and its relative concepts. First, we define a C1{\cal C}^1 fuzzy submanifold after reviewing C1{\cal C}^1-fuzzy manifold definition. In main section, we defined the Lie group and some its relative concepts such as fuzzy transformation group,…

2009-08-03abs ↗pdf ↗

The future value of a security is described as a random variable. Distribution of this random variable is the formal image of risk uncertainty. On the other side, any present value is defined as a value equivalent to the given future value. This equivalence relationship is a subjective. Thus follows, that present value…

2013-02-03abs ↗pdf ↗

The main objective is to present a some variant of the Black - Litterman model. We consider the canonical case when priori return is determined by means such excess return from the CAPM market portfolio which is derived using reverse optimization method. Then the a priori return is at risk quantified uncertainty. On th…

2016-01-03abs ↗pdf ↗

A new model for detecting overlapping communities in weighted networks.

problem Community detection in overlapping weighted networks with mixed membership and edge weights.
method Mixed membership distribution-free (MMDF) model with an efficient spectral algorithm and fuzzy weighted modularity.
result The MMDF model can estimate community memberships and evaluate community quality for weighted networks.

Fuzzy prediction sets generalize binary predictions to include elements at varying confidence levels.

problem Binary prediction sets are limited; fuzzy prediction sets offer richer guarantees.
method Generalize prediction sets to fuzzy sets, showing they are e-values with merging properties.
result Optimal e-values lead to optimal fuzzy prediction sets, including optimal conformal prediction.

Paper introduces lexical ratio to measure portfolio diversification.

problem Traditional diversification metrics overlook non-numerical relationships.
method Uses textual data to capture diversification dimensions through entropy-based insights.
result Lexical ratio (LR) outperforms traditional metrics in optimizing portfolio returns.

NLR models often perform worse than LR for outlying input data in environmental sciences.

problem NLR models often give poor predictions for input data outside the training domain.
method Screened input data for outliers, using linear extrapolation for outliers based on NLR within the non-outlier domain.
result NLROR_{\mathrm{OR}} approach reduces poor extrapolation and tends to outperform NLR and LR for outliers.

Paper investigates differentiable fuzzy implications and their suitability for learning.

problem Analyzing differentiable fuzzy implications and their suitability for learning.
method Investigates the properties of fuzzy implications in a differentiable setting and introduces a new family of fuzzy implications.
result Various fuzzy implications are unsuitable for differentiable learning, and a new family of fuzzy implications is introduced.

We consider coupled nonholonomic LR systems on the product of Lie groups. As examples, we study nn-dimensional variants of the spherical support system and the rubber Chaplygin sphere. For a special choice of the inertia operator, it is proved that the rubber Chaplygin sphere, after reduction and a time reparametrizat…

2009-02-10abs ↗pdf ↗

A new fuzzy clustering method using hyperbolic smoothing for large datasets.

problem Building fuzzy clusters for large data sets efficiently.
method A novel smoothing numerical approach to relax the sum-of-squares criterion, converting the problem into a differentiable optimization problem.
result The method produces better fuzzy partitions compared to traditional fuzzy CC-means.

The majority of medical documents and electronic health records (EHRs) are in text format that poses a challenge for data processing and finding relevant documents. Looking for ways to automatically retrieve the enormous amount of health and medical knowledge has always been an intriguing topic. Powerful methods have b…

2017-05-02abs ↗pdf ↗

Unified probabilistic foundation for fuzzy simplicial sets in dimensionality reduction.

problem Lack of clear probabilistic interpretation in fuzzy simplicial sets.
method Introducing a probabilistic framework explaining fuzzy simplicial sets as marginals of probability measures on simplicial sets.
result Unified probabilistic theoretical foundation for fuzzy simplicial sets.

We find optimal learning rate schedules for a random feature model.

problem Choosing optimal learning rates for deep learning models.
method We analyze a powerlaw random feature model trained with SGD, considering optimal schedules as numerical and analytical problems.
result We discover two regimes: easy and hard phases, with different optimal learning rate schedules.

This paper introduces the concept of kernels on fuzzy sets as a similarity measure for [0,1][0,1]-valued functions, a.k.a. \emph{membership functions of fuzzy sets}. We defined the following classes of kernels: the cross product, the intersection, the non-singleton and the distance-based kernels on fuzzy sets. Applicabili…

2019-07-30abs ↗pdf ↗