Search Results for author: Sandesh Ghimire

Found 22 papers, 8 papers with code

Solving Masked Jigsaw Puzzles with Diffusion Vision Transformers

1 code implementation10 Apr 2024 Jinyang Liu, Wondmgezahu Teshome, Sandesh Ghimire, Mario Sznaier, Octavia Camps

Solving image and video jigsaw puzzles poses the challenging task of rearranging image fragments or video frames from unordered sequences to restore meaningful images and video sequences.

Inferring Relational Potentials in Interacting Systems

no code implementations23 Oct 2023 Armand Comas-Massagué, Yilun Du, Christian Fernandez, Sandesh Ghimire, Mario Sznaier, Joshua B. Tenenbaum, Octavia Camps

In this work, we propose Neural Interaction Inference with Potentials (NIIP) as an alternative approach to discover such interactions that enables greater flexibility in trajectory modeling: it discovers a set of relational potentials, represented as energy functions, which when minimized reconstruct the original trajectory.

Trajectory Forecasting Trajectory Modeling

Learning Transferable Object-Centric Diffeomorphic Transformations for Data Augmentation in Medical Image Segmentation

no code implementations25 Jul 2023 Nilesh Kumar, Prashnna K. Gyawali, Sandesh Ghimire, Linwei Wang

To this end, we propose a novel object-centric data augmentation model that is able to learn the shape variations for the objects of interest and augment the object in place without modifying the rest of the image.

Data Augmentation Image Segmentation +4

Geometry of Score Based Generative Models

no code implementations9 Feb 2023 Sandesh Ghimire, Jinyang Liu, Armand Comas, Davin Hill, Aria Masoomi, Octavia Camps, Jennifer Dy

We demonstrate that looking from geometric perspective enables us to answer many of these questions and provide new interpretations to some known results.

Bayesian Inference

Divide and Compose with Score Based Generative Models

no code implementations5 Feb 2023 Sandesh Ghimire, Armand Comas, Davin Hill, Aria Masoomi, Octavia Camps, Jennifer Dy

Towards the direction of having more control over image manipulation and conditional generation, we propose to learn image components in an unsupervised manner so that we can compose those components to generate and manipulate images in informed manner.

Disentanglement Image Generation +1

Boundary-Aware Uncertainty for Feature Attribution Explainers

1 code implementation5 Oct 2022 Davin Hill, Aria Masoomi, Max Torop, Sandesh Ghimire, Jennifer Dy

In this work we propose the Gaussian Process Explanation UnCertainty (GPEC) framework, which generates a unified uncertainty estimate combining decision boundary-aware uncertainty with explanation function approximation uncertainty.

Reliable Estimation of KL Divergence using a Discriminator in Reproducing Kernel Hilbert Space

no code implementations NeurIPS 2021 Sandesh Ghimire, Aria Masoomi, Jennifer Dy

To achieve this objective, we 1) present a novel construction of the discriminator in the Reproducing Kernel Hilbert Space (RKHS), 2) theoretically relate the error probability bound of the KL estimates to the complexity of the discriminator in the RKHS space, 3) present a scalable way to control the complexity (RKHS norm) of the discriminator for a reliable estimation of KL divergence, and 4) prove the consistency of the proposed estimator.

Learning Theory

Enhancing Mixup-based Semi-Supervised Learning with Explicit Lipschitz Regularization

1 code implementation23 Sep 2020 Prashnna Kumar Gyawali, Sandesh Ghimire, Linwei Wang

On three benchmark data sets and one real-world biomedical data set, we demonstrate that this combined regularization results in improved generalization performance of SSL when learning from a small amount of labeled data.

Learning Invariant Feature Representation to Improve Generalization across Chest X-ray Datasets

no code implementations4 Aug 2020 Sandesh Ghimire, Satyananda Kashyap, Joy T. Wu, Alexandros Karargyris, Mehdi Moradi

Through pneumonia-classification experiments on multi-source chest X-ray datasets, we show that this algorithm helps in improving classification accuracy on a new source of X-ray dataset.

Learning Geometry-Dependent and Physics-Based Inverse Image Reconstruction

no code implementations18 Jul 2020 Xiajun Jiang, Sandesh Ghimire, Jwala Dhamala, Zhiyuan Li, Prashnna Kumar Gyawali, Linwei Wang

However, many reconstruction problems involve imaging physics that are dependent on the underlying non-Euclidean geometry.

Image Reconstruction

Semi-supervised Medical Image Classification with Global Latent Mixing

1 code implementation22 May 2020 Prashnna Kumar Gyawali, Sandesh Ghimire, Pradeep Bajracharya, Zhiyuan Li, Linwei Wang

In this work, we argue that regularizing the global smoothness of neural functions by filling the void in between data points can further improve SSL.

General Classification Image Classification +1

Analysis of Discriminator in RKHS Function Space for Kullback-Leibler Divergence Estimation

no code implementations25 Feb 2020 Sandesh Ghimire, Prashnna K Gyawali, Linwei Wang

Based on this theory, we then present a scalable way to control the complexity of the discriminator for a reliable estimation of KL divergence.

Generative Adversarial Network

Improving Disentangled Representation Learning with the Beta Bernoulli Process

1 code implementation3 Sep 2019 Prashnna Kumar Gyawali, Zhiyuan Li, Cameron Knight, Sandesh Ghimire, B. Milan Horacek, John Sapp, Linwei Wang

We note that the independence within and the complexity of the latent density are two different properties we constrain when regularizing the posterior density: while the former promotes the disentangling ability of VAE, the latter -- if overly limited -- creates an unnecessary competition with the data reconstruction objective in VAE.

Decision Making Representation Learning

Semi-Supervised Learning by Disentangling and Self-Ensembling Over Stochastic Latent Space

1 code implementation22 Jul 2019 Prashnna Kumar Gyawali, Zhiyuan Li, Sandesh Ghimire, Linwei Wang

In this work, we hypothesize -- from the generalization perspective -- that self-ensembling can be improved by exploiting the stochasticity of a disentangled latent space.

Data Augmentation Multi-Label Classification +1

Bayesian Optimization on Large Graphs via a Graph Convolutional Generative Model: Application in Cardiac Model Personalization

1 code implementation1 Jul 2019 Jwala Dhamala, Sandesh Ghimire, John L. Sapp, B. Milan Horacek, Linwei Wang

In this paper, we present a novel graph convolutional VAE to allow generative modeling of non-Euclidean data, and utilize it to embed Bayesian optimization of large graphs into a small latent space.

Bayesian Optimization

Generative Modeling and Inverse Imaging of Cardiac Transmembrane Potential

no code implementations12 May 2019 Sandesh Ghimire, Jwala Dhamala, Prashnna Kumar Gyawali, John L. Sapp, B. Milan Horacek, Linwei Wang

We introduce a novel model-constrained inference framework that replaces conventional physiological models with a deep generative model trained to generate TMP sequences from low-dimensional generative factors.

Deep Generative Model with Beta Bernoulli Process for Modeling and Learning Confounding Factors

no code implementations31 Oct 2018 Prashnna K Gyawali, Cameron Knight, Sandesh Ghimire, B. Milan Horacek, John L. Sapp, Linwei Wang

While deep representation learning has become increasingly capable of separating task-relevant representations from other confounding factors in the data, two significant challenges remain.

Representation Learning

Improving Generalization of Sequence Encoder-Decoder Networks for Inverse Imaging of Cardiac Transmembrane Potential

no code implementations12 Oct 2018 Sandesh Ghimire, Prashnna Kumar Gyawali, John L. Sapp, Milan Horacek, Linwei Wang

The results demonstrate that the generalization ability of an inverse reconstruction network can be improved by constrained stochasticity combined with global aggregation of temporal information in the latent space.

Learning Theory

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