Search Results for author: Ehsan Abbasnejad

Found 52 papers, 16 papers with code

BruSLeAttack: A Query-Efficient Score-Based Black-Box Sparse Adversarial Attack

no code implementations8 Apr 2024 Viet Quoc Vo, Ehsan Abbasnejad, Damith C. Ranasinghe

We study the unique, less-well understood problem of generating sparse adversarial samples simply by observing the score-based replies to model queries.

Adversarial Attack

Do Deep Neural Network Solutions Form a Star Domain?

1 code implementation12 Mar 2024 Ankit Sonthalia, Alexander Rubinstein, Ehsan Abbasnejad, Seong Joon Oh

This means that two independent solutions can be connected by a linear path with low loss, given one of them is appropriately permuted.

Premonition: Using Generative Models to Preempt Future Data Changes in Continual Learning

1 code implementation12 Mar 2024 Mark D. McDonnell, Dong Gong, Ehsan Abbasnejad, Anton Van Den Hengel

We show here that the combination of a large language model and an image generation model can similarly provide useful premonitions as to how a continual learning challenge might develop over time.

Continual Learning Fine-Grained Image Classification +3

Neural Redshift: Random Networks are not Random Functions

no code implementations4 Mar 2024 Damien Teney, Armand Nicolicioiu, Valentin Hartmann, Ehsan Abbasnejad

Prevailing explanations are based on implicit biases of gradient descent (GD) but they cannot account for the capabilities of models from gradient-free methods nor the simplicity bias recently observed in untrained networks.

Zero-shot Retrieval: Augmenting Pre-trained Models with Search Engines

no code implementations29 Nov 2023 Hamed Damirchi, Cristian Rodríguez-Opazo, Ehsan Abbasnejad, Damien Teney, Javen Qinfeng Shi, Stephen Gould, Anton Van Den Hengel

Large pre-trained models can dramatically reduce the amount of task-specific data required to solve a problem, but they often fail to capture domain-specific nuances out of the box.

Retrieval

Progressive Feature Adjustment for Semi-supervised Learning from Pretrained Models

no code implementations9 Sep 2023 Hai-Ming Xu, Lingqiao Liu, Hao Chen, Ehsan Abbasnejad, Rafael Felix

As an effective way to alleviate the burden of data annotation, semi-supervised learning (SSL) provides an attractive solution due to its ability to leverage both labeled and unlabeled data to build a predictive model.

Selective Mixup Helps with Distribution Shifts, But Not (Only) because of Mixup

no code implementations26 May 2023 Damien Teney, Jindong Wang, Ehsan Abbasnejad

We have found a new equivalence between two successful methods: selective mixup and resampling.

Binary Classification

ProtoCon: Pseudo-label Refinement via Online Clustering and Prototypical Consistency for Efficient Semi-supervised Learning

no code implementations CVPR 2023 Islam Nassar, Munawar Hayat, Ehsan Abbasnejad, Hamid Rezatofighi, Gholamreza Haffari

Finally, ProtoCon addresses the poor training signal in the initial phase of training (due to fewer confident predictions) by introducing an auxiliary self-supervised loss.

Online Clustering Pseudo Label

Energy-based Self-Training and Normalization for Unsupervised Domain Adaptation

no code implementations ICCV 2023 Samitha Herath, Basura Fernando, Ehsan Abbasnejad, Munawar Hayat, Shahram Khadivi, Mehrtash Harandi, Hamid Rezatofighi, Gholamreza Haffari

EBL can be used to improve the instance selection for a self-training task on the unlabelled target domain, and 2. alignment and normalizing energy scores can learn domain-invariant representations.

Unsupervised Domain Adaptation

Stock Market Prediction via Deep Learning Techniques: A Survey

no code implementations24 Dec 2022 Jinan Zou, Qingying Zhao, Yang Jiao, Haiyao Cao, Yanxi Liu, Qingsen Yan, Ehsan Abbasnejad, Lingqiao Liu, Javen Qinfeng Shi

Existing surveys on stock market prediction often focus on traditional machine learning methods instead of deep learning methods.

Stock Market Prediction

Bayesian Learning with Information Gain Provably Bounds Risk for a Robust Adversarial Defense

1 code implementation5 Dec 2022 Bao Gia Doan, Ehsan Abbasnejad, Javen Qinfeng Shi, Damith C. Ranasinghe

We recognize the adversarial learning approach for approximating the multi-modal posterior distribution of a Bayesian model can lead to mode collapse; consequently, the model's achievements in robustness and performance are sub-optimal.

Adversarial Defense

Predicting is not Understanding: Recognizing and Addressing Underspecification in Machine Learning

no code implementations6 Jul 2022 Damien Teney, Maxime Peyrard, Ehsan Abbasnejad

Underspecification refers to the existence of multiple models that are indistinguishable in their in-domain accuracy, even though they differ in other desirable properties such as out-of-distribution (OOD) performance.

BIG-bench Machine Learning Model Selection

EBMs vs. CL: Exploring Self-Supervised Visual Pretraining for Visual Question Answering

no code implementations29 Jun 2022 Violetta Shevchenko, Ehsan Abbasnejad, Anthony Dick, Anton Van Den Hengel, Damien Teney

In a simple setting similar to CLEVR, we find that CL representations also improve systematic generalization, and even match the performance of representations from a larger, supervised, ImageNet-pretrained model.

Contrastive Learning Out of Distribution (OOD) Detection +4

Astock: A New Dataset and Automated Stock Trading based on Stock-specific News Analyzing Model

1 code implementation14 Jun 2022 Jinan Zou, Haiyao Cao, Lingqiao Liu, YuHao Lin, Ehsan Abbasnejad, Javen Qinfeng Shi

In addition, we propose a self-supervised learning strategy based on SRLP to enhance the out-of-distribution generalization performance of our system.

Decision Making News Classification +5

Active Learning by Feature Mixing

3 code implementations CVPR 2022 Amin Parvaneh, Ehsan Abbasnejad, Damien Teney, Reza Haffari, Anton Van Den Hengel, Javen Qinfeng Shi

We identify unlabelled instances with sufficiently-distinct features by seeking inconsistencies in predictions resulting from interventions on their representations.

Active Learning

Query Efficient Decision Based Sparse Attacks Against Black-Box Deep Learning Models

1 code implementation31 Jan 2022 Viet Quoc Vo, Ehsan Abbasnejad, Damith C. Ranasinghe

The ability to extract information from solely the output of a machine learning model to craft adversarial perturbations to black-box models is a practical threat against real-world systems, such as autonomous cars or machine learning models exposed as a service (MLaaS).

BIG-bench Machine Learning

RamBoAttack: A Robust Query Efficient Deep Neural Network Decision Exploit

1 code implementation10 Dec 2021 Viet Quoc Vo, Ehsan Abbasnejad, Damith C. Ranasinghe

In our study, we first deep dive into recent state-of-the-art decision-based attacks in ICLR and SP to highlight the costly nature of discovering low distortion adversarial employing gradient estimation methods.

TnT Attacks! Universal Naturalistic Adversarial Patches Against Deep Neural Network Systems

no code implementations19 Nov 2021 Bao Gia Doan, Minhui Xue, Shiqing Ma, Ehsan Abbasnejad, Damith C. Ranasinghe

Now, an adversary can arm themselves with a patch that is naturalistic, less malicious-looking, physically realizable, highly effective achieving high attack success rates, and universal.

iDARTS: Differentiable Architecture Search with Stochastic Implicit Gradients

1 code implementation21 Jun 2021 Miao Zhang, Steven Su, Shirui Pan, Xiaojun Chang, Ehsan Abbasnejad, Reza Haffari

A key challenge to the scalability and quality of the learned architectures is the need for differentiating through the inner-loop optimisation.

Neural Architecture Search

All Labels Are Not Created Equal: Enhancing Semi-supervision via Label Grouping and Co-training

1 code implementation CVPR 2021 Islam Nassar, Samitha Herath, Ehsan Abbasnejad, Wray Buntine, Gholamreza Haffari

We train two classifiers with two different views of the class labels: one classifier uses the one-hot view of the labels and disregards any potential similarity among the classes, while the other uses a distributed view of the labels and groups potentially similar classes together.

Semi-Supervised Image Classification

Learning for Visual Navigation by Imagining the Success

no code implementations28 Feb 2021 Mahdi Kazemi Moghaddam, Ehsan Abbasnejad, Qi Wu, Javen Shi, Anton Van Den Hengel

ForeSIT is trained to imagine the recurrent latent representation of a future state that leads to success, e. g. either a sub-goal state that is important to reach before the target, or the goal state itself.

Navigate Reinforcement Learning (RL) +1

Counterfactual Vision-and-Language Navigation: Unravelling the Unseen

no code implementations NeurIPS 2020 Amin Parvaneh, Ehsan Abbasnejad, Damien Teney, Qinfeng Shi, Anton Van Den Hengel

The task of vision-and-language navigation (VLN) requires an agent to follow text instructions to find its way through simulated household environments.

counterfactual Embodied Question Answering +2

Counterfactual Vision and Language Learning

no code implementations CVPR 2020 Ehsan Abbasnejad, Damien Teney, Amin Parvaneh, Javen Shi, Anton van den Hengel

It is particularly remarkable that this success has been achieved on the basis of comparatively small datasets, given the scale of the problem.

counterfactual Question Answering +1

On the Value of Out-of-Distribution Testing: An Example of Goodhart's Law

no code implementations NeurIPS 2020 Damien Teney, Kushal Kafle, Robik Shrestha, Ehsan Abbasnejad, Christopher Kanan, Anton Van Den Hengel

Out-of-distribution (OOD) testing is increasingly popular for evaluating a machine learning system's ability to generalize beyond the biases of a training set.

Model Selection Question Answering +1

Optimistic Agent: Accurate Graph-Based Value Estimation for More Successful Visual Navigation

no code implementations7 Apr 2020 Mahdi Kazemi Moghaddam, Qi Wu, Ehsan Abbasnejad, Javen Qinfeng Shi

Through empirical studies, we show that our agent, dubbed as the optimistic agent, has a more realistic estimate of the state value during a navigation episode which leads to a higher success rate.

Reinforcement Learning (RL) Visual Navigation

Unshuffling Data for Improved Generalization

no code implementations27 Feb 2020 Damien Teney, Ehsan Abbasnejad, Anton Van Den Hengel

subsets treated as multiple training environments can guide the learning of models with better out-of-distribution generalization.

Clustering Data Augmentation +3

On Incorporating Semantic Prior Knowledge in Deep Learning Through Embedding-Space Constraints

no code implementations30 Sep 2019 Damien Teney, Ehsan Abbasnejad, Anton Van Den Hengel

We also show that incorporating this type of prior knowledge with our method brings consistent improvements, independently from the amount of supervised data used.

Data Augmentation Question Answering +1

On Incorporating Semantic Prior Knowlegde in Deep Learning Through Embedding-Space Constraints

no code implementations25 Sep 2019 Damien Teney, Ehsan Abbasnejad, Anton Van Den Hengel

We also show that incorporating this type of prior knowledge with our method brings consistent improvements, independently from the amount of supervised data used.

Data Augmentation Question Answering +1

Februus: Input Purification Defense Against Trojan Attacks on Deep Neural Network Systems

1 code implementation9 Aug 2019 Bao Gia Doan, Ehsan Abbasnejad, Damith C. Ranasinghe

Notably, in contrast to existing approaches, our approach removes the need for ground-truth labelled data or anomaly detection methods for Trojan detection or retraining a model or prior knowledge of an attack.

Cryptography and Security

Deep Single Image Deraining Via Estimating Transmission and Atmospheric Light in rainy Scenes

no code implementations22 Jun 2019 Yinglong Wang, Qinfeng Shi, Ehsan Abbasnejad, Chao Ma, Xiaoping Ma, Bing Zeng

Instead of using the estimated atmospheric light directly to learn a network to calculate transmission, we utilize it as ground truth and design a simple but novel triangle-shaped network structure to learn atmospheric light for every rainy image, then fine-tune the network to obtain a better estimation of atmospheric light during the training of transmission network.

Single Image Deraining

Show, Price and Negotiate: A Negotiator with Online Value Look-Ahead

no code implementations7 May 2019 Amin Parvaneh, Ehsan Abbasnejad, Qi Wu, Javen Qinfeng Shi, Anton Van Den Hengel

Negotiation, as an essential and complicated aspect of online shopping, is still challenging for an intelligent agent.

What's to know? Uncertainty as a Guide to Asking Goal-oriented Questions

no code implementations CVPR 2019 Ehsan Abbasnejad, Qi Wu, Javen Shi, Anton Van Den Hengel

We propose a solution to this problem based on a Bayesian model of the uncertainty in the implicit model maintained by the visual dialogue agent, and in the function used to select an appropriate output.

Visual Dialog

Gold Seeker: Information Gain from Policy Distributions for Goal-oriented Vision-and-Langauge Reasoning

no code implementations CVPR 2020 Ehsan Abbasnejad, Iman Abbasnejad, Qi Wu, Javen Shi, Anton Van Den Hengel

For each potential action a distribution of the expected outcomes is calculated, and the value of the potential information gain assessed.

Visual Dialog

Deep Lipschitz networks and Dudley GANs

no code implementations ICLR 2018 Ehsan Abbasnejad, Javen Shi, Anton Van Den Hengel

To facilitate this, we develop both theoretical and practical building blocks, using which one can construct different neural networks using a large range of metrics, as well as ensure Lipschitz condition and sufficient capacity of the networks.

Infinite Variational Autoencoder for Semi-Supervised Learning

no code implementations CVPR 2017 Ehsan Abbasnejad, Anthony Dick, Anton Van Den Hengel

This paper presents an infinite variational autoencoder (VAE) whose capacity adapts to suit the input data.

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