Dipanjan Das

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We present a brief history and overview of statistical methods in frame-semantic parsing – the automatic analysis of text using the theory of frame semantics. We discuss how the FrameNet lexicon and frameannotated datasets have been used by statistical NLP researchers to build usable, state-of-the-art systems. We also focus on future directions in(More)
A robust chunker can drastically reduce the complexity of parsing of natural language text. Chunking for Indian languages require a novel approach because of the relatively unrestricted order of words within a word group. A computational framework for chunking based on valency theory and feature structures has been described here. The paper also draws an(More)
We take a look at a model of computer aided generation of Hindustani Classical music. The system implemented using the model is essentially a simulation of the ‘Arohana’ and ‘Avarohana’ of a particular ‘Raga’. The artificial generator creates note sequences using hand-crafted bigram finite state models which conform to the grammar of a Raga. We also(More)
Free word order languages have relatively unrestricted local word group or phrase structures that make the problem of chunking quite challenging. On the other hand, a robust chunker can drastically reduce the complexity of a parser that follows. We present here a computational framework for chunking of free word order languages based on a generalization of(More)
Modern software ecosystem is data-centric. Data exfiltration due to the attacks of Memory Scraper type malwares is an emerging threat. In this paper, we set up an appropriate mathematical model capturing the threat such attacks pose to Identity Based Cryptosystems (IBE). Following the formalism, we demonstrate an attack on popular Boneh-Franklin CCA2 secure(More)
Ring signature enables an user to anonymously sign a message on behalf of a group of users termed as ‘ring’ formed in an ‘ad-hoc’ manner. A naive scheme produces a signature linear in the size of the ring, but this is extremely inefficient when ring size is large. Dodis et al. proposed a constant size scheme in EUROCRYPT’13, but provably secure in random(More)
Modern mobile bootloaders play an important role in both the function and the security of the device. They help ensure the Chain of Trust (CoT), where each stage of the boot process verifies the integrity and origin of the following stage before executing it. This process, in theory, should be immune even to attackers gaining full control over the operating(More)
I design computationally intensive statistical methods for the discovery of syntactic and semantic structure in natural language text. A major focus of my research is on the use of both linguistically annotated as well as unannotated textual data, from which the aforementioned statistical models are estimated. My work has resulted in significant(More)
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