8 research outputs found
Recommended from our members
Finding good enough coins under symmetric and asymmetric information
We study the problem of returning m coins with biases above 0:5. These good enough coins that are returned by the agent should be acceptable to the authority by meeting the authority's Family Wise Error Rate constraint. We design adaptive algorithms that invoke Sequential Probability Ratio Test to find these good enough coins. We consider scenarios that differ in terms of the information available about the underlying Bayesian setting. The symmetry or asymmetry of the underlying setup, i.e., the difference between what the agent and the authority know about the underlying prior and the support, presents different challenges. We also make notes on the algorithms' sample complexity.Electrical and Computer Engineerin
Coding for storage and testing
The problem of reconstructing strings from substring information has found many applications due to its importance in genomic data sequencing and DNA- and polymer-based data storage. Motivated by platforms that use chains of binary synthetic polymers as the recording media and read the content via tandem mass spectrometers, we propose new a family of codes that allows for both unique string reconstruction and correction of multiple mass errors.
We first consider the paradigm where the masses of substrings of the input string form the evidence set. We consider two approaches: The first approach pertains to asymmetric errors and the error-correction is achieved by introducing redundancy that scales linearly with the number of errors and logarithmically with the length of the string. The proposed construction allows for the string to be uniquely reconstructed based only on its erroneous substring composition multiset. The asymptotic code rate of the scheme is one, and decoding is accomplished via a simplified version of the Backtracking algorithm used for the Turnpike problem. For symmetric errors, we use a polynomial characterization of the mass information and adapt polynomial evaluation code constructions for this setting. In the process, we develop new efficient decoding algorithms for a constant number of composition errors.
The second part of this dissertation addresses a practical paradigm that requires reconstructing mixtures of strings based on the union of compositions of their prefixes and suffixes, generated by mass spectrometry devices. We describe new coding methods that allow for unique joint reconstruction of subsets of strings selected from a code and provide upper and lower bounds on the asymptotic rate of the underlying codebooks. Our code constructions combine properties of binary and Dyck strings and can be extended to accommodate missing substrings in the pool.
In the final chapter of this dissertation, we focus on group testing. We begin with a review of the gold-standard testing protocol for Covid-19, real-time, reverse transcription PCR, and its properties and associated measurement data such as amplification curves that can guide the development of appropriate and accurate adaptive group testing protocols. We then proceed to examine various off-the-shelf group testing methods for Covid-19, and identify their strengths and weaknesses for the application at hand. Finally, we present a collection of new analytical results for adaptive semiquantitative group testing with combinatorial priors, including performance bounds, algorithmic solutions, and noisy testing protocols. The worst-case paradigm extends and improves upon prior work on semiquantitative group testing with and without specialized PCR noise models
Group Testing with Runlength Constraints for Topological Molecular Storage
Motivated by applications in topological DNA-based data storage, we introduce
and study a novel setting of Non-Adaptive Group Testing (NAGT) with runlength
constraints on the columns of the test matrix, in the sense that any two 1's
must be separated by a run of at least d 0's. We describe and analyze a
probabilistic construction of a runlength-constrained scheme in the zero-error
and vanishing error settings, and show that the number of tests required by
this construction is optimal up to logarithmic factors in the runlength
constraint d and the number of defectives k in both cases. Surprisingly, our
results show that runlength-constrained NAGT is not more demanding than
unconstrained NAGT when d=O(k), and that for almost all choices of d and k it
is not more demanding than NAGT with a column Hamming weight constraint only.
Towards obtaining runlength-constrained Quantitative NAGT (QNAGT) schemes with
good parameters, we also provide lower bounds for this setting and a nearly
optimal probabilistic construction of a QNAGT scheme with a column Hamming
weight constraint