"Trustworthy AI for Transparency, Robustness and Risk Assessment", US Armaments Center/DEVCOM, 2025
"Information Theoretic Approach to Analyzing LLM Vulnerabilities", NSF, NAIRR Pilot Program, PI: K.P. Subbalakshmi, 2024 - 2025.
"Role of LLMs in Persuasion Detection and Generation", PI: K.P. Subbalakshmi, AFRL/Griffiss Institute, 2024
"Machine Learning Approach for Optimizing Real-Time Orbital Sensor Tasking", SpaceWerx, 2022
“IUCRC Phase I: Stevens Center for Research Towards Advancing Financial Technologies”, PI: Steven Yang, Co-PIs: George Calhoun, Jeff Nickerson, K.P. Subbalakshmi, Darinka Dentcheva, July 1 2021 – June 30, 2026.
“SII Planning: ARIES: Center for Agile, RelIablE, Scalable Spectrum”, PI: Walid Saad; Co-PIs: Arnold Swindlehurst, Narayan Mandayam, Douglas Sicker, Andreas Molisch, Harpreet Dhillon; Senior Personnel: K.P. Subbalakshmi, R. Chandramouli and others, August 15 2020 – July 30 2021.
``WRT-1017: Keyphrase Extraction using Language Embeddings", US Department of Defense - Office of the Deputy Assistant Secretary of Defense for Systems Engineering, DEVCOM Picatinny Arsenal, March 2020 - March 2021.
``RT-213: Systems Engineering Business and Analytics", PI: K.P. Subbalakshmi , US Department of Defense - Office of the Deputy Assistant Secretary of Defense for Systems Engineering, Picatinny Arsenal, 2018.
``RT-202: Workshop and Research Roadmap for Sensemaking Technologies", PI: K.P. Subbalakshmi, US Department of Defense - Office of the Deputy Assistant Secretary of Defense for Systems Engineering, ODNI, 2018.
"Dynamic Spectrum Access Policy", PI: K.P. Subbalakshmi, Air Force Research Laboratory, Rome NY, September 2017 - August 2020, $500K.
"CyberCorps: Scholarship for Service Program at Stevens", PI: Susanne Wetzel, Co-PIs K.P. Subbalakshmi, Anotnio Nicolosi and Thomas Lechler, National Science Foundation, Scholarship for Service Program, 2014 - 2019, $3.2M.
Bingyang Wen, Fan Yang and K.P. Subbalakshmi
NeurIPS 2022 Attention Workshop
Exploring the Relationship between Attention Mechanisms and Model Explainability: An Information Theoretic Perspective
Attention mechanisms have recently demonstrated impressive performance on a range of NLP tasks, and attention scores are often used as a proxy for model explainability. However, there is a debate on whether attention weights can, in fact, be used to identify the most important inputs to a model. We approach this question from an information theoretic perspective by measuring the mutual information between the model output and the hidden states.
From extensive experiments, we draw the following conclusions: (i) Additive and Deep attention mechanisms are likely to be better at indicating the most informative hidden states (compared to Scaled Dot-product); (ii) Complexity of attention mechanisms or encoders is not related with the explainability in most applications; (iii) ablation studies indicate that Additive attention can actively learn to explain the importance of its input hidden representations; (iv) when attention values are nearly the same, the rank order of attention values is not consistent with the rank order of the mutual information; (v) Using Gumbel-Softmax with a temperature lower than one tends to produce a more skewed attention score distribution compared to Softmax and hence is a better choice for explainable design; (vi) some building blocks are better at preserving the correlation between the ordered list of mutual information and attention weights order (e.g., the combination of BiLSTM encoder and Additive attention).
Our findings indicate that attention mechanisms do have the potential to function as a shortcut to model explanations when they are carefully combined with other model elements.
Ning Wang, Yupeng Cao, Shuai Hao, Zongru Shao, K.P. Subbalakshmi
INTERSPEECH 2021
Modular Multi-Modal Attention Network for Alzheimer's Disease Detection Using Patient Audio and Language Data
In this work, we propose a modular multi-modal architecture to automatically detect Alzheimer’s disease using the dataset provided in the ADReSSo challenge. Both acoustic and text-based features are used in this architecture. Since the dataset provides only audio samples of controls and patients, we use Google
cloud-based speech-to-text API to automatically transcribe the audio files to extract text-based features. Several kinds of audio features are extracted using standard packages. The proposed approach consists of 4 networks: C-attention-acoustic network (for acoustic features only), C-Attention-FT network (for linguistic features only), C-Attention-Embedding network (for language embeddings and acoustic embeddings), and a unified network (uses all of those features). The architecture combines attention networks and a convolutional neural network (C-Attention network) in order to process these features. Experimental
results show that the C-Attention-Unified network with Linguistic features and X-Vector embeddings achieves the best accuracy of 80.28% and F1 score of 0.825 on the test dataset.
Ning Wang, Fan Luo, Yuvraj Shivtare, Varsha D. Badal, K. P. Subbalakshmi, R. Chandramouli and Ellen Lee
Learning Models for Suicide Prediction from Social Media Posts
CLPsych 2021, NAACL 2021
Learning Models for Suicide Prediction from Social Media Posts
We propose a deep learning architecture and test three other machine learning models to automatically detect individuals that will attempt suicide within (1) 30 days and (2) six months, using their social media post data provided in (Macavaney et al., 2021) via the CLPsych 2021 shared task.
Additionally, we create and extract three sets of handcrafted features for suicide risk detection based on the three-stage theory of suicide and prior work on emotions and the use of pronouns among persons exhibiting suicidal ideations.
Extensive experimentations show that some of the traditional machine learning methods outperform the baseline with an F1 score of 0.741 and F2 score of 0.833 on subtask 1 (prediction of a suicide attempt 30 days prior). However, the proposed deep learning method outperforms the baseline with F1 score of 0.737 and F2 score of 0.843 on subtask 2 (prediction of suicide 6 months prior).
Mingxuan Chen, Ning Wang and K. P. Subbalakshmi
Explainable Rumor Detection using Inter and Intra-feature Attention Networks
TrueFact Workshop, KDD 2020
Explainable Rumor Detection using Inter and Intra-feature Attention Networks
Rumor (Fake News) identification is a very critical task with significant implications to economy, democracy as well as public health and safety.
We tackle the problem of automated detection of rumors in social media in this work by designing a modular explainable architecture that uses both latent and handcrafted features and can be expanded to as many new classes of features as desired.
This approach allows the end user to not only determine whether the piece of information on the social media is real of a rumor, but also give explanations on why the algorithm arrived at its conclusion.
Explainable Architecture for Alzheimer's Disease Detection
In this work, we propose three explainable deep learning architectures to automatically detect patients with Alzheimer's disease based on their language abilities. The architectures use: (1) only the part-of-speech features; (2) only language embedding features and (3) both of these feature classes via a unified architecture, respectively.
We use self-attention mechanisms and interpretable 1-dimensional ConvolutionalNeural Network (CNN) to generate two types of explanations of the model's action: intra-class explanation and inter-class explanation.
Extensive experimentation and comparison with several recent models show that our method outperforms these methods with an accuracy of 92.2% and F1 score of 0.952 on the DementiaBank dataset while being able to generate explanations.
Ning Wang, Fan Luo, Vishal Peddagangireddy, K.P. Subbalakshmi and R. Chandramouli
Personalized Early Stage Alzheimer's Disease Detection: A Case Study of President Reagan's Speeches,
BioNLP 2020
Personalized Early Stage Alzheimer's Disease Detection
Alzheimers disease (AD)-related global healthcare cost is estimated to be $1 trillion by 2050. Currently, there is no cure for this disease; however, clinical studies show that early diagnosis and intervention helps to extend the quality of life and inform technologies for personalized mental healthcare. Clinical research indicates that the onset and progression of Alzheimers disease lead to dementia and other mental health issues. As a result, the language capabilities of patient start to decline. In this paper, we show that machine learning-based unsupervised clustering of and anomaly detection with linguistic biomarkers are promising approaches for intuitive visualization and personalized early stage detection of Alzheimers disease. We demonstrate this approach on 10 years (1980 to 1989) of President Ronald Reagans speech data set. Key linguistic biomarkers that indicate early-stage AD are identified. Experimental results show that Reagan had early onset of Alzheimers sometime between 1983 and 1987. This finding is corroborated by prior work that analyzed his interviews using a statistical technique. The proposed technique also identifies the exact speeches that reflect linguistic biomarkers for early stage AD.
Alireza Louni and K.P. Subbalakshmi
IEEE Transactions on Computational Social Systems, Feb 2018.
Who Spread That Rumor?
We address the problem of estimating the source of a rumor in large-scale social networks.
Internode relationship strengths in real social networks are random. We model this uncertainty by using random, non-homogenous edge weights on the underlying social network graph. We propose a novel two-stage algorithm that uses the modularity of the social network to locate the source of the rumor with fewer sensor nodes than other existing algorithms. We also propose a novel method to select these sensor nodes.
We evaluate our algorithm using a large data set from Twitter and Sina Weibo. Real-world time series data are used to model the uncertainty in social relationship strengths. Simulations show that the proposed algorithm can determine the actual source within two hops, 69%-80% of the time, when the diameter of the networks varies between 7 and 13.
Details coming soon...
Details coming soon...
Details coming soon...