Demonstration venue · read-only. Every page can be browsed; the buttons that would change it are switched off. Create an account to run TaxoReview on your own data. A simulation from public publication records: the people listed were not invited and did not agree to review.
? Tutorial for this page

Mehran Kafai

dblp:47/10798 · DBLP profile ↗
← Back
11ranked-venue papers
5as first author
2since 2021 · last 2025
0000-0003-0238-7010ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 5 · 2 first-author · 2 since 2021Graphics, computer vision, multimedia, augmented reality and games · 4 · 2 first-authorDatabases, data management, data science and information retrieval · 2 · 1 since 2021Security and privacy · 1 · 1 first-authorApplied, interdisciplinary, general and emerging computing · 1 · 1 first-author

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Artificial intelligence
3 papers
Kernel, tree and ensemble methods · 35% Efficient and distributed learning · 18% Optimization for machine learning · 18%
Network and information security
1 paper
Security and privacy of machine learning · 50% Hardware security and side channels · 50%
Databases, data mining, and information retrieval
2 papers
Web and social media mining · 46% Machine learning and data management · 40% Knowledge graphs · 14%
Computer graphics and multimedia
1 paper
Multimedia analysis and retrieval · 100%

Topics — the 14 heaviest of 16, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Hardware security and side channels
intellectual property protection
0.912025
Web Intellectual Property at Risk: Preventing Unauthorized Real-Time Retrieval by Large Language Models · EMNLP 2025
Web and social media mining
misinformation detection
0.612022
Joint International Workshop on Misinformation and Misbehavior Mining on the Web & Making a Credible Web for Tomorrow (MIS2-TrueFact) · KDD 2022
Machine learning › Kernel, tree and ensemble methods › kernel methods
kernel approximation
0.412019
CROification: Accurate Kernel Classification with the Efficiency of Sparse Linear SVM · IEEE Trans. Pattern Anal. Mach. Intell. 2019
Machine learning › Kernel, tree and ensemble methods
kernel methods
0.412019
CROification: Accurate Kernel Classification with the Efficiency of Sparse Linear SVM · IEEE Trans. Pattern Anal. Mach. Intell. 2019
Machine learning › Efficient and distributed learning
model compression
0.412019
CROification: Accurate Kernel Classification with the Efficiency of Sparse Linear SVM · IEEE Trans. Pattern Anal. Mach. Intell. 2019
Machine learning › Optimization for machine learning › sparse learning
sparse linear SVM
0.412019
CROification: Accurate Kernel Classification with the Efficiency of Sparse Linear SVM · IEEE Trans. Pattern Anal. Mach. Intell. 2019
Natural language and speech › Language models and text generation
retrieval-augmented generation
0.312025
Web Intellectual Property at Risk: Preventing Unauthorized Real-Time Retrieval by Large Language Models · EMNLP 2025
Machine learning and data management › kernel methods
kernel approximation
0.212016
The CRO kernel: Using Concomitant Rank Order hashes for sparse high dimensional randomized feature maps · ICDE 2016
Machine learning and data management
kernel methods
0.212016
The CRO kernel: Using Concomitant Rank Order hashes for sparse high dimensional randomized feature maps · ICDE 2016
Computer vision › Face, body and person analysis
face recognition
0.212014
Reference Face Graph for Face Recognition · IEEE Trans. Inf. Forensics Secur. 2014
Computer vision › Face, body and person analysis › face recognition › robust face recognition
unconstrained face recognition
0.212014
Reference Face Graph for Face Recognition · IEEE Trans. Inf. Forensics Secur. 2014
Multimedia analysis and retrieval › image retrieval › instance-level image retrieval
face retrieval
0.212014
Discrete Cosine Transform Locality-Sensitive Hashes for Face Retrieval · IEEE Trans. Multim. 2014
Multimedia analysis and retrieval
image retrieval
0.212014
Discrete Cosine Transform Locality-Sensitive Hashes for Face Retrieval · IEEE Trans. Multim. 2014
Multimedia analysis and retrieval
locality-sensitive hashing
0.212014
Discrete Cosine Transform Locality-Sensitive Hashes for Face Retrieval · IEEE Trans. Multim. 2014

Methods — techniques the papers use, named apart from their topics

semantic perturbation · 1.7black-box optimization · 1.7discrete cosine transform · 0.6randomized feature maps · 0.4CRO kernel · 0.4hadamard transform · 0.2concomitant rank order hashing · 0.2reference face graph · 0.2hash suppression · 0.2centrality measures · 0.2DCT locality sensitive hashing · 0.2
YearPublicationVenuePosition
2025 Web Intellectual Property at Risk: Preventing Unauthorized Real-Time Retrieval by Large Language Models
abstract
The protection of cyber Intellectual Property (IP) such as web content is an increasingly critical concern.The rise of large language models (LLMs) with online retrieval capabilities enables convenient access to information but often undermines the rights of original content creators.As users increasingly rely on LLM-generated responses, they gradually diminish direct engagement with original information sources, which will significantly reduce the incentives for IP creators to contribute, and lead to a saturating cyberspace with more AIgenerated content.In response, we propose a novel defense framework that empowers web content creators to safeguard their web-based IP from unauthorized LLM real-time extraction and redistribution by leveraging the semantic understanding capability of LLMs themselves.Our method follows principled motivations and effectively addresses an intractable black-box optimization problem.Real-world experiments demonstrated that our methods improve defense success rates from 2.5% to 88.6% on different LLMs, outperforming traditional defenses such as configuration-based restrictions.
Yisheng Zhong, Yizhu Wen, Mehran Kafai, Heng Huang 0001, Hanqing Guo, Zhuangdi Zhu
EMNLP4
2022 Joint International Workshop on Misinformation and Misbehavior Mining on the Web & Making a Credible Web for Tomorrow (MIS2-TrueFact)
abstract
The MIS2-TrueFact is geared towards bringing academic, industry, and government researchers and practitioners together to tackle the challenges in misinformation, misbehavior, and data quality issues on the web with heterogeneous and multi-modal sources of information including texts, images, videos, relational data, social networks, and knowledge graphs.
Pamela Bhattacharya, Jing Gao 0004, Meng Jiang 0001, Mehran Kafai, Srijan Kumar, Qi Li 0012, Neil Shah, Sihong Xie, Philip S. Yu, Ming Zeng 0001
KDD4
2019 CROification: Accurate Kernel Classification with the Efficiency of Sparse Linear SVM
abstract
Kernel methods have been shown to be effective for many machine learning tasks such as classification and regression. In particular, support vector machines with the Gaussian kernel have proved to be powerful classification tools. The standard way to apply kernel methods is to use the kernel trick, where the inner product of the vectors in the feature space is computed via the kernel function. Using the kernel trick for SVMs, however, leads to training that is quadratic in the number of input vectors and classification that is linear with the number of support vectors. We introduce a new kernel, the CRO (Concomitant Rank Order) kernel that approximates the Gaussian kernel on the unit sphere. We also introduce a randomized feature map, called the CRO feature map that produces sparse, high-dimensional feature vectors whose inner product asymptotically equals the CRO kernel. Using the Discrete Cosine Transform for computing the CRO feature map ensures that the cost of computing feature vectors is low, allowing us to compute the feature map explicitly. Combining the CRO feature map with linear SVM we introduce the CROification algorithm which gives us the efficiency of a sparse high-dimensional linear SVM with the accuracy of the Gaussian kernel SVM.
Mehran Kafai, Kave Eshghi
IEEE Trans. Pattern Anal. Mach. Intell.1
2016 The CRO kernel: Using Concomitant Rank Order hashes for sparse high dimensional randomized feature maps
abstract
Kernel methods have been shown to be effective for many machine learning tasks such as classification, clustering and regression. In particular, support vector machines with the RBF kernel have proved to be powerful classification tools. The standard way to apply kernel methods is to use the `kernel trick', where the inner product of the vectors in the feature space is computed via the kernel function. Using the kernel trick for SVMs, however, leads to training that is quadratic in the number of input vectors and classification that is linear with the number of support vectors. We introduce a new kernel, the CRO (Concomitant Rank Order) kernel that approximates the RBF kernel for unit length input vectors. We also introduce a new randomized feature map, based on concomitant rank order hashing, that produces sparse, high dimensional feature vectors whose inner product asymptotically equals the CRO kernel. Using the Hadamard transform for computing the CRO hashes ensures that the cost of computing feature vectors is very low. Thus, for unit length input vectors, we get the accuracy of the RBF kernel with the efficiency of a sparse high dimensional linear kernel. We show the efficacy of our approach using a number of standard datasets.
Kave Eshghi, Mehran Kafai
ICDE2
2016 Person Reidentification With Reference Descriptor
abstract
Person identification across nonoverlapping cameras, also known as person reidentification, aims to match people at different times and locations. Reidentifying people is of great importance in crucial applications such as wide-area surveillance and visual tracking. Due to the appearance variations in pose, illumination, and occlusion in different camera views, person reidentification is inherently difficult. To address these challenges, a reference-based method is proposed for person reidentification across different cameras. Instead of directly matching people by their appearance, the matching is conducted in a reference space where the descriptor for a person is translated from the original color or texture descriptors to similarity measures between this person and the exemplars in the reference set. A subspace is first learned in which the correlations of the reference data from different cameras are maximized using regularized canonical correlation analysis (RCCA). For reidentification, the gallery data and the probe data are projected onto this RCCA subspace and the reference descriptors (RDs) of the gallery and probe are generated by computing the similarity between them and the reference data. The identity of a probe is determined by comparing the RD of the probe and the RDs of the gallery. A reranking step is added to further improve the results using a saliency-based matching scheme. Experiments on publicly available datasets show that the proposed method outperforms most of the state-of-the-art approaches.
Mehran Kafai, Songfan Yang, Bir Bhanu
IEEE Trans. Circuits Syst. Video Technol.2
2014 Zapping Index: Using Smile to Measure Advertisement Zapping Likelihood
abstract
In marketing and advertising research, “zapping” is defined as the action when a viewer stops watching a commercial. Researchers analyze users' behavior in order to prevent zapping which helps advertisers to design effective commercials. Since emotions can be used to engage consumers, in this paper, we leverage automated facial expression analysis to understand consumers' zapping behavior. Firstly, we provide an accurate moment-to-moment smile detection algorithm. Secondly, we formulate a binary classification problem (zapping/non-zapping) based on real-world scenarios, and adopt smile response as the feature to predict zapping. Thirdly, to cope with the lack of a metric in advertising evaluation, we propose a new metric called Zapping Index (ZI). ZI is a moment-to-moment measurement of a user's zapping probability. It gauges not only the reaction of a user, but also the preference of a user to commercials. Finally, extensive experiments are performed to provide insights and we make recommendations that will be useful to both advertisers and advertisement publishers.
Songfan Yang, Mehran Kafai, Bir Bhanu
IEEE Trans. Affect. Comput.2
2014 Reference Face Graph for Face Recognition
abstract
Face recognition has been studied extensively; however, real-world face recognition still remains a challenging task. The demand for unconstrained practical face recognition is rising with the explosion of online multimedia such as social networks, and video surveillance footage where face analysis is of significant importance. In this paper, we approach face recognition in the context of graph theory. We recognize an unknown face using an external reference face graph (RFG). An RFG is generated and recognition of a given face is achieved by comparing it to the faces in the constructed RFG. Centrality measures are utilized to identify distinctive faces in the reference face graph. The proposed RFG-based face recognition algorithm is robust to the changes in pose and it is also alignment free. The RFG recognition is used in conjunction with DCT locality sensitive hashing for efficient retrieval to ensure scalability. Experiments are conducted on several publicly available databases and the results show that the proposed approach outperforms the state-of-the-art methods without any preprocessing necessities such as face alignment. Due to the richness in the reference set construction, the proposed method can also handle illumination and expression variation.
Mehran Kafai, Bir Bhanu
IEEE Trans. Inf. Forensics Secur.1
2014 Discrete Cosine Transform Locality-Sensitive Hashes for Face Retrieval
abstract
Descriptors such as local binary patterns perform well for face recognition. Searching large databases using such descriptors has been problematic due to the cost of the linear search, and the inadequate performance of existing indexing methods. We present Discrete Cosine Transform (DCT) hashing for creating index structures for face descriptors. Hashes play the role of keywords: an index is created, and queried to find the images most similar to the query image. Common hash suppression is used to improve retrieval efficiency and accuracy. Results are shown on a combination of six publicly available face databases (LFW, FERET, FEI, BioID, Multi-PIE, and RaFD). It is shown that DCT hashing has significantly better retrieval accuracy and it is more efficient compared to other popular state-of-the-art hash algorithms.
Mehran Kafai, Kave Eshghi, Bir Bhanu
IEEE Trans. Multim.1
2013 Reference-based person re-identification
abstract
Person re-identification refers to recognizing people across non-overlapping cameras at different times and locations. Due to the variations in pose, illumination condition, background, and occlusion, person re-identification is inherently difficult. In this paper, we propose a reference-based method for across camera person re-identification. In the training, we learn a subspace in which the correlations of the reference data from different cameras are maximized using Regularized Canonical Correlation Analysis (RCCA). For re-identification, the gallery data and the probe data are projected into the RCCA subspace and the reference descriptors (RDs) of the gallery and probe are constructed by measuring the similarity between them and the reference data. The identity of the probe is determined by comparing the RD of the probe and the RDs of the gallery. Experiments on benchmark dataset show that the proposed method outperforms the state-of-the-art approaches.
Mehran Kafai, Songfan Yang, Bir Bhanu
AVSS2
2012 Cluster-Classification Bayesian Networks for head pose estimation
Mehran Kafai, Bir Bhanu
ICPR1
2012 Dynamic Bayesian Networks for Vehicle Classification in Video
abstract
Vehicle classification has evolved into a significant subject of study due to its importance in autonomous navigation, traffic analysis, surveillance and security systems, and transportation management. While numerous approaches have been introduced for this purpose, no specific study has been conducted to provide a robust and complete video-based vehicle classification system based on the rear-side view where the camera's field of view is directly behind the vehicle. In this paper, we present a stochastic multiclass vehicle classification system which classifies a vehicle (given its direct rear-side view) into one of four classes: sedan, pickup truck, SUV/minivan, and unknown. A feature set of tail light and vehicle dimensions is extracted which feeds a feature selection algorithm to define a low-dimensional feature vector. The feature vector is then processed by a hybrid dynamic Bayesian network to classify each vehicle. Results are shown on a database of 169 videos for four classes.
Mehran Kafai, Bir Bhanu
IEEE Trans. Ind. Informatics1