A Concurrent Perspective on Smart Contracts

In this paper, we explore remarkable similarities between multi-transactional behaviors of smart contracts in cryptocurrencies such as Ethereum and classical problems of shared-memory concurrency. We examine two real-world examples from the Ethereum blockchain and analyzing how they are vulnerable to bugs that are closely reminiscent to those that often occur in traditional concurrent programs. We then elaborate on the relation between observable contract behaviors and well-studied concurrency topics, such as atomicity, interference, synchronization, and resource ownership. The described contracts-as-concurrent-objects analogy provides deeper understanding of potential threats for smart contracts, indicate better engineering practices, and enable applications of existing state-of-the-art formal verification techniques.Comment: 15 page

Access to Life-Saving Medicines and Intellectual Property Rights: An Ethical Assessment

© 2011 Cambridge University Press. Online edition of the journal is available at http://journals.cambridge.org/action/displayJournal?jid=CQHDying before one’s time has been a prominent theme in classic literature and poetry. Catherine Linton’s youthful death in Wuthering Heights leaves behind a bereft Heathcliff and generations of mourning readers. The author herself, Emily Brontë, died young from tuberculosis. John Keats’ Ode on Melancholy captures the transitory beauty of 19th century human lives too often ravished by early death. Keats also died of tuberculosis, aged 25. “The bloom, whose petals nipped before they blew, died on the promise of the fruit” is how Percy Bysshe Shelley expressed his grief over Keats’ death. Emily Dickinson wrote So Has a Daisy Vanished, being driven into depression by the early loss of loved ones from typhoid and tuberculosis

Faraday\u27s Laws of Electrolysis

Physics has no equal, perhaps, in bringing the student to an appreciation of the beauty, the order and the harmony or the universe, and thus drawing the heart and the mind to God whose unbounded powers executed the eternal and marvelous wonders that are all about us. It is intensely fascinating to take peeps into the laboratories of God and wonder what will be the next secret that He will let man in on. It seems as the ages roll by He gradually allows us to share more and more in His secrets or nature; He appears to be slowly un­raveling to man the mysteries or earth, sky and sea. In this thesis, my farewell bow to Marquette, I wish to express my appreciation and gratitude for the good things received at Milwaukee\u27s great university; my appreciation for the wisdom and truth of her philosophy, the conciseness and completeness of her science, the beauty and power of her art, the kindness and courtesy of the administration, and the scholarship and personality of her faculty

Thoreau\u27s Civil Disobedience: A Reassessment

Thoreau’s case is easy in one sense and difficult in another. One of the chief attractions of Civil Disobedience, and one of its necessary limitations, lies in its prophetic quality. Recent American history has confirmed Thoreau’s good judgment in abhorring state-supported racism and a questionable war. But in sympathizing with his outrage over these conditions, we are spared the difficult test to our forbearance that arises when others dissent against issues that lack the persuasive moral justification of Thoreau’s case. So in this respect at least, Thoreau presents a comparatively easy case. His case is difficult in that he minimizes the problem which makes civil disobedience interesting in the first place. That is, Thoreau does not present himself as a genuinely loyal citizen for whom civil disobedience is a difficult act fraught with the pain that gives it moral persuasiveness. Thoreau’s solution to the age-old problem of what to do when one can no longer be both a good person and a good citizen is to deny the problem. For Thoreau, one is always an individual before he is a citizen

A study of the schools for mentally handicapped children conducted by the Sisters of the Poor Child Jesus in Austria, Belgium, Germany, Luxembourg, and the Netherlands

The major purpose of this study was to survey a group of schools for mentally handicapped children conducted by one religious congregation in five countries of Western Europe in order to ascertain and interpret specific characteristics and general procedures as well as basic educational principles which affect special education. The writer had a dual intent: (1) to place these schools within their own national setting and so to evaluate them; (2) to bring them into a focus with schools tor mentally handicapped children in the United States, and to point out aspects which seemed common to both systems and those which seemed unique or individual. The specific objectives or the study encompassed the following considerations: (1) the place of the retarded or handicapped child in the apostolic activity of the congregation, (2) the functioning ability and special needs of retarded children and the manner in which both are being served by the included schools, (3) the programs and the physical facilities, (4) the philosophy and the qualifications of the teachers and of the aides, (5) information concerning the national structure of the special school system, (6) the sources of financial income, and (7) after-school planning. Another objective was added during the study: (8) the variation in emphasis or attitude toward the child in special education as differentiated from that noticed here in America. Comparison was regarded as an end in itself and not as a tool toward an evaluation. In accordance with present attitudes toward comparative education, evaluation on the whole was avoided because re­liable universal yardsticks are lacking

Measurement of neutron fluence at En=20-100 MeV using a stacked scintillator spectrometer

Includes bibliographical references.The present work demonstrates a new application of a stacked spectrometer which has been developed in the Physics Department of the University of Cape Town. The spectrometer used in the present work consists of two identical segments of NE213 liquid scintillator, of dimensions 13.0 x 13.0 x 7.0 cm³ The present work demonstrates a new application of a stacked spectrometer which has been developed in the Physics Department of the University of Cape Town. The spectrometer used in the present work consists of two identical segments of NE213 liquid scintillator, of dimensions 13.0 x 13.0 x 7.0 cm³, stacked behind one-another, and allows response functions to be measured for neutrons of energy up to 100 MeV, which are minimally affected by charged particle escape

The equalization of educational opportunities in secondary schools

Thesis (Ed.M.)--Boston University, 1946. This item was digitized by the Internet Archive