Trading isolation for certifiable randomness expansion

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (page 41).A source of random bits is an important resource in modern cryptography, algorithms and statistics. Can one ever be sure that a "random" source is truly random, or in the case of cryptography, secure against potential adversaries or eavesdroppers? Recently the study of non-local properties of entanglement has produced an interesting new perspective on this question, which we will refer to broadly as Certifiable Randomness Expansion (CRE). CRE refers generally to a process by which a source of information-theoretically certified randomness can be constructed based only on two simple assumptions: the prior existence of a short random seed and the ability to ensure that two or more black-box devices do not communicate (i.e. are non-signaling). In this work we make progress on a conjecture of [Col09] which proposes a method for indefinite certifiable randomness expansion using a growing number of devices (we actually prove a slight modification of the original conjecture in which we use the CHSH game as a subroutine rather than the GHZ game as originally proposed). The proof requires a technique not used before in the study of randomness expansion, and inspired by the tools developed in [RUV12]. The result also establishes the existence of a protocol for constant factor CRE using a finite number of devices (here the constant factor can be much greater than 1). While much better expansion rates (polynomial, and even exponential) have been achieved with only two devices, our analysis requires techniques not used before in the study of randomness expansion, and represents progress towards a protocol which is provably secure against a quantum eavesdropper who knows the input to the protocol.by Matthew Ryan Coudron.S.M

Protein droplet actuation on superhydrophobic surfaces: A new approach toward anti-biofouling electrowetting systems

© 2017 The Royal Society of Chemistry. This is an Open Access article, distributed under the terms of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence https://creativecommons.org/licenses/by/3.0/.Among Lab-on-a-chip techniques, Digital microfluidics (DMF), allowing the precise actuation of discrete droplets, is a highly promising, flexible, biochemical assay platform for biomedical and bio-detection applications. However the durability of DMF systems remains a challenge due to biofouling of the droplet-actuating surface when high concentrations of biomolecules are employed. To address this issue, the use of superhydrophobic materials as the actuating surface in DMF devices is examined. The change in contact angle by electrowetting of deionised water and ovalbumin protein samples is characterised on different surfaces (hydrophobic and superhydrophobic). Ovalbumin droplets at 1 mg ml-1 concentration display better electrowetting reversibility on Neverwet®, a commercial superhydrophobic material, than on Cytop®, a typical DMF hydrophobic material. Biofouling rate, characterised by roll-off angle measurement of ovalbumin loaded droplets and further confirmed by measurements of the mean fluorescence intensity of labelled fibrinogen, appears greatly reduced on Neverwet®. Transportation of protein laden droplets (fibrinogen at concentration 0.1 mg ml-1 and ovalbumin at concentration 1 mg ml-1 and 10 mg ml-1) is successfully demonstrated using electrowetting actuation on both single-plate and parallel-plate configurations with performance comparable to that of DI water actuation. In addition, although droplet splitting requires further attention, merging and efficient mixing are demonstrated.Peer reviewe

The Antimicrobial Effect of STERIPLEX HC in comparison with Sodium Hypochlorite on Enterococcus faecalis

The study objective was to compare the antimicrobial activity of STERIPLEX™ HC with 5.25% sodium hypochlorite (NaOCl) at different dilutions (50%, 25%, 10%, 1%, 0.1%) and different time intervals (1, 3, 5 minutes) on Enterococcus faecalis. All data was analyzed using an ANOVA. The 50%, 25%, and 10% dilutions of both disinfectants reduced the colony forming unit (CFU) count to below the limit of detection (50 CFU/ml) after one minute. The 1% dilutions at each of the time intervals show NaOCl was significantly more effective than STERIPLEX™ HC (all Ps \u3c .0001) in reducing the CFU/ml count. The 0.1% dilutions of NaOCl and STERIPLEX™ HC at 1 minute, were not different (P = 0.7808), while at 3 minutes and 5 minutes NaOCl was significantly more effective (P = 0.0098 and P \u3c .0001, respectively)

Quantum Algorithms and the Power of Forgetting

The so-called welded tree problem provides an example of a black-box problem that can be solved exponentially faster by a quantum walk than by any classical algorithm [Andrew M. Childs et al., 2003]. Given the name of a special entrance vertex, a quantum walk can find another distinguished exit vertex using polynomially many queries, though without finding any particular path from entrance to exit. It has been an open problem for twenty years whether there is an efficient quantum algorithm for finding such a path, or if the path-finding problem is hard even for quantum computers. We show that a natural class of efficient quantum algorithms provably cannot find a path from entrance to exit. Specifically, we consider algorithms that, within each branch of their superposition, always store a set of vertex labels that form a connected subgraph including the entrance, and that only provide these vertex labels as inputs to the oracle. While this does not rule out the possibility of a quantum algorithm that efficiently finds a path, it is unclear how an algorithm could benefit by deviating from this behavior. Our no-go result suggests that, for some problems, quantum algorithms must necessarily forget the path they take to reach a solution in order to outperform classical computation

Quantum algorithms and the power of forgetting

The so-called welded tree problem provides an example of a black-box problem that can be solved exponentially faster by a quantum walk than by any classical algorithm. Given the name of a special ENTRANCE vertex, a quantum walk can find another distinguished EXIT vertex using polynomially many queries, though without finding any particular path from ENTRANCE to EXIT. It has been an open problem for twenty years whether there is an efficient quantum algorithm for finding such a path, or if the path-finding problem is hard even for quantum computers. We show that a natural class of efficient quantum algorithms provably cannot find a path from ENTRANCE to EXIT. Specifically, we consider algorithms that, within each branch of their superposition, always store a set of vertex labels that form a connected subgraph including the ENTRANCE, and that only provide these vertex labels as inputs to the oracle. While this does not rule out the possibility of a quantum algorithm that efficiently finds a path, it is unclear how an algorithm could benefit by deviating from this behavior. Our no-go result suggests that, for some problems, quantum algorithms must necessarily forget the path they take to reach a solution in order to outperform classical computation.Comment: 49 pages, 9 figure

The Design of an Innovative Research Led, Undergraduate Programme for Effective Development of R&D Skills and Learning.

Daniel McCluskey, Christabel Tan, Mark Tracey, Ian Johnston, Loic Coudron, ‘The Design of an Innovative Research Led, Undergraduate Programme for Effective Development of R&D Skills and Learning’, paper presented at the 1st ASEAN Innovation Conference, Vientiane, Lao People’s Democratic Republic, 25-26 October, 2016.Engineering education has suffered a shift in focus between research led fundamental engineering and vocational training that has resulted in many graduate engineers equipped without a thorough grasp of either skill set. Furthermore the belief that these two components of education can be explicitly separated appears to undermine the notion of what a graduate engineer is. The purpose of this paper is to outline the development of a research informed, undergraduate, module that incorporates the principles of the Massachusetts Institute of Technology developed approach to engineering education where the core components of study are formed around the concept of CDIO (Conceive, Design, Implement, Operate). We outline our initial starting concept for the taught module and systematically break down the CDIO approach, applying the outcomes of this process to the design of the engineering module. The resultant module structure incorporates the majority of the CDIO principles, and highlights the mechanisms by which research can inform undergraduate teaching without straying away from the development of practical skills required by the graduate engineer. This work suggests that the CDIO approach, with minor modification, can be tailored to a single isolated module structure as well as a whole curriculum provided that there is a clear objective outlined at the start