Exploring blockchain technologies with an innovative multi-layered ontology design tool and eMudra – a novel peer to peer currency exchange application

Recent years have witnessed significant interest in shared economy applications and consequently a proliferation of such applications have emerged where people are monetizing their things. This thesis focuses on solving the problem of leftover foreign currency exchange as a shared economy application. Existing shared economy applications such as Ola, Uber or Airbnb are not deployed as decentralized applications (Dapps) leveraging blockchain and the Internet of Things (IoT), which are relatively recent technologies leading to more efficient applications that do not require the intervention of trusted third parties. Blockchain technology can be merged with IoT infrastructure to provide an immutable ledger of all the transactions related to shared economy applications; an immutable ledger is critical to the elimination of trusted third parties, making the system trustless. When blockchain and IoT are combined they can give rise to a plethora of useful shared economy applications — automatic payment mechanisms, digital rights management are some instances and in the case of this thesis a unique solution for the leftover foreign currency exchange problem. This thesis demonstrates the implementation of a novel permissioned consortium blockchain-based leftover foreign currency exchange platform that has been designed using a multi-layered blockchain ontology created with an innovative ontology design tool. The leftover foreign currency exchange problem arises because every year millions of travellers undertake international tours and need to perform currency exchange. However, there is a deficit of suitable currency exchange applications that would help travellers exchange money profitably and conveniently, especially small amounts of cash. This thesis proposes a novel peer to peer currency exchange application – e-Mudra, exploiting blockchain technology that would allow users to choose or quote their preferred exchange rates and exchange currencies including cash money with peer travellers without any middleman deciding the rates. The research work described focuses on an in-depth study of blockchain technology and a new multi-layered blockchain ontology is created with an innovative ontology design tool that facilitates generation of simple and complex ontologies enabling the design of blockchain (and other) applications using these ontologies. The novel ontology design tool created in this research work following a new Ontology Development Life Cycle and an ontology design methodology was used to design a blockchain ontology and a wallet ontology as examples of use, where the currency exchange application design (e-Mudra) is an instance of the blockchain ontology

Exploring the development of thinking in senior secondary mathematics : a focus on probability

Higher order thinking skills have been identified as desirable although elusive outcomes of many educational curricula. Through a qualitative case study, the alignment between the three levels of the curriculum: intended, implemented, and attained, was examined to determine the tensions and possibilities in the development of mathematical and thinking skills in senior secondary students in Gippsland, a large regional area of Victoria, Australia. Probability was the mathematical content area of focus. Data from document analysis of the intended curriculum, textbooks as the implemented curriculum, and assessments as the attained curriculum, was combined with qualitative data from semi-structured interviews with twenty students and fourteen senior secondary mathematics teachers. These diverse data sources scaffolded each other to identify tensions and possibilities influencing development of student thinking in senior secondary mathematics. This research demonstrated that the flow of content via the intended-implemented-attained curriculum was not adequate to describe all the influences on student learning. The lens of Activity Theory (Engeström, 2001) came closer to capturing the related complexities whereby the textbooks, calculators, bound reference books and assessments, combined with the balance of agency demonstrated by the teachers and students, were found to both support and cause tensions within the activity system. Probability was found to be a valuable topic to study in relation to the development of thinking skills due to its relevance in decision making, how it linked many areas of mathematics and the uniqueness of the classic, experimental, and subjective views of probability. This study is significant in the contribution it makes to understanding the tensions and possibilities associated with the development of mathematical thinking relating to probability through the lens of Activity Theory. While the intended curriculum encouraged a range of thinking skills, this intended curriculum could be implemented in a way that promotes memorisation rather than the intended higher order thinking. This study concludes with recommendations for the curriculum designers, textbook publishers, teachers, and students which may support the development of mathematical and thinking skills.Doctor of Philosoph

An Algebraic Approach to Non-Malleability

In their seminal work on non-malleable cryptography, Dolev, Dwork and Naor, showed how to construct a non-malleable commitment with logarithmically-many rounds / slots , the idea being that any adversary may successfully maul in some slots but would fail in at least one. Since then new ideas have been introduced, ultimately resulting in constant-round protocols based on any one-way function. Yet, in spite of this remarkable progress, each of the known constructions of non-malleable commitments leaves something to be desired. In this paper we propose a new technique that allows us to construct a non-malleable protocol with only a single ``slot , and to improve in at least one aspect over each of the previously proposed protocols. Two direct byproducts of our new ideas are a four round non-malleable commitment and a four round non-malleable zero-knowledge argument, the latter matching the round complexity of the best known zero-knowledge argument (without the non-malleability requirement). The protocols are based on the existence of one-way functions and admit very efficient instantiations via standard homomorphic commitments and sigma protocols. Our analysis relies on algebraic reasoning, and makes use of error correcting codes in order to ensure that committers\u27 tags differ in many coordinates. One way of viewing our construction is as a method for combining many atomic sub-protocols in a way that simultaneously amplifies soundness and non-malleability, thus requiring much weaker guarantees to begin with, and resulting in a protocol which is much trimmer in complexity compared to the existing ones

Analysis and design of algorithms : double hashing and parallel graph searching

The following is in two parts, corresponding to the two separate topics in the dissertation.Probabilistic Analysis of Double HashingIn [GS78], a deep and elegant analysis shows that double hashing is asymptotically equivalent to the ideal uniform hashing up to a load factor of about 0.319. In this paper we show how a resampling technique can be used to develop a surprisingly simple proof of the result that this equivalence holds for load factors arbitrarily close to 1.Parallel Depth First Search of Planar Directed Acyclic GraphsIn 1988, Kao [Kao88] presented the first NC algorithm for the depth first search of a directed planar graph. Recently, Kao and Klein [KK90] reduced the number of processors required from O(n^4) to linear, but the time bound is O(log^8 n).We present an algorithm for the depth first search of a planar directed acyclic graph with k sources using O(n) processors and O(log k log n) time on a CRCW PRAM model. For planar dags with a single source and a single sink, we present a simple optimal algorithm which gives the depth first search in O(log n) time with O(n/log n) processors on an EREW PRAM. For a single-source multiple-sink planar dag, we have an O(log n) time O(n) processor EREW algorithm. The EREW algorithms assume that the embedding is given. A simplified variant of the depth first search of a multisource planar dag can be used to solve the single source reachability problem for a planar directed acyclic graph in O(log^2 n) time and O(n) processors on an CRCW PRAM. Since an O(log^4 n) algorithm for this problem is used as a subroutine by Kao and Klein in their depth first search for the general planar directed graph, this will lower their time bound by a factor of log^2 n. Our work uses the concept of a planar Euler tour depth first search, a depth first search in which the Euler tour around the tree is planar and crosses no tree edge. This concept may prove to be of use in other parallel algorithms for planar graphs

The Purple, October 1923

The Purple is a student publication offering news of the month, editorials, poetry, college news and alumni news. This issue contains the following: Table of Contents The New Chapel Pass in Review! The Poet The Bal Masque To a New-Born Babe A Greek Tragedy To a Drooping Golden-Rod Ideals of an Idler Loss Shakespeare\u27s Inner Shrine The Locomotives Facts Under the Rose Editorial College Chronicle Alumni Athletics Thanksgivin

Across Borders: Migrancy, Bilingualism, and the Reconfiguration of Postcolonialism in Junot Díaz’s Fiction

Equipped with Junot Díaz’s novel The Brief Wondrous Life of Oscar Wao (2007) and his collections of short stories Drown (1996) and This Is How You Lose Her (2012), this thesis interprets the fundamentals of migrant literature, studies Díaz’s tools of migrant depiction, and examines contemporary postcolonial and migrant discourse. This is performed in three integral segments of study. First, the unstable terminology surrounding migration and hybrid self-fashioning is discussed with identity theory from theorists such as Homi K. Bhabha and Elleke Boehmer. This experience of hybrid identity is related to Yunior de las Casas, the primary narrator of all three texts. Later, accompanied by language theory from Doris Sommer and Lourdes Torres, bilingualism is revealed as the authoritative device to depict migrant lifestyles. This code-switching is exemplified by Yunior’s seamless transitions between English and Spanish. Finally, the narrator’s historical footnotes are discussed as a reconfiguration of postcolonial discourse that explores the link between postcolonial, diasporic, and migrant literature while arguing that the overlap between these does not make the genres interchangeable. The ambition is to explain the criteria for migrant literature and to use Díaz’s texts to explain the interpretations, tools, and effects of migrant literature