MixEth: Efficient, Trustless Coin Mixing Service for Ethereum

Coin mixing is a prevalent privacy-enhancing technology for cryptocurrency users. In this paper, we present MixEth, which is a trustless coin mixing service for Turing-complete blockchains. MixEth does not rely on a trusted setup and is more efficient than any proposed trustless coin tumbler. It requires only 3 on-chain transactions at most per user and 1 off-chain message. It achieves strong notions of anonymity and is able to resist denial-of-service attacks. Furthermore the underlying protocol can also be used to efficiently shuffle ballots, ciphertexts in a trustless and decentralized manner

Education for Librarianship in the Next Century

published or submitted for publicatio

A Geomechanical Study of the Mississippian Boone Formation

The Boone Formation in northwest Arkansas is a chert-limestone sequence analogous to the subsurface Mississippi Lime reservoir in parts of Oklahoma and Kansas. It has low permeability and produces via horizontal drilling and hydraulic fracturing. The response to stimulation by fracturing is dependent on the quantity of chert in the area. Chert nodules and laterally extensive chert layers in the sequence are variable. Locally, cm- to dm-scale chert bedding is continuous and comprises up to 50% of the outcrop. Elsewhere, the chert is nodular and intermittent. Samples collected from representative outcrops spanning the thickness and aerial extent of the formation are being targeted to establish a geomechanical framework for the reservoir. Samples include end members of chert and limestone and interlayered limestone and chert facies with variable thicknesses and contact geometries. Each sample was cored, confined, and oriented perpendicular to bedding. Compressive strength testing of core plugs were performed to determine the stiffness of the rock, describe how each facies responds to loading and failure, determine how limestone rheology is influenced by the presence of chert, and characterize how rock properties influence the compressive strength of the sample. Rockwell Hardness testing was performed on the samples to understand the strength of the rock in an additional quantitative way. The compressive strength of the samples and the Rockwell Hardness values of the samples were compared with each other and with the inherent properties of the rock (e.g. lithology, natural fractures, contact types, and facies) to understand and assess correlations and trends in an effort to understand the geomechanics of the Boone Formation

A multi-agent system to support location based group decision making in mobile teams

This paper describes an agent-based approach for developing a location-based asynchronous group decision-support system for mobile teams. The approach maximises the use of reusable service components (GSCmas — generic service component for multi-agent systems) as the main interaction mechanism between agents to allow flexible support of a new group-decision process. The paper describes the architecture of a GSCmas and provides details of how the GSCmas is integrated within a decision support system. Finally a system (mPower) based on the proposed approach is introduced and applied to a location-based group decision problem

Analysing mark-recapture-recovery data in the presence of missing covariate data via multiple imputation

We consider mark–recapture–recovery data with additional individual time-varying continuous covariate data. For such data it is common to specify the model parameters, and in particular the survival probabilities, as a function of these covariates to incorporate individual heterogeneity. However, an issue arises in relation to missing covariate values, for (at least) the times when an individual is not observed, leading to an analytically intractable likelihood. We propose a two-step multiple imputation approach to obtain estimates of the demographic parameters. Firstly, a model is fitted to only the observed covariate values. Conditional on the fitted covariate model, multiple “complete” datasets are generated (i.e. all missing covariate values are imputed). Secondly, for each complete dataset, a closed form complete data likelihood can be maximised to obtain estimates of the model parameters which are subsequently combined to obtain an overall estimate of the parameters. Associated standard errors and 95 % confidence intervals are obtained using a non-parametric bootstrap. A simulation study is undertaken to assess the performance of the proposed two-step approach. We apply the method to data collected on a well-studied population of Soay sheep and compare the results with a Bayesian data augmentation approach. Supplementary materials accompanying this paper appear on-line.Publisher PDFPeer reviewe

Context and Relationships: Ireland and Irish Studies

Students, editors, researchers, and the public are necessarily concerned with the context and relationships of names and topics found when reading texts. What other documents relate this topic? Where and when did this happen? What else was going on around that time and place? Who were the people and institutions mentioned? How were they related? What else did they do? This project will develop three tools: A Context Finder will find information in reference works about names, words, or phrases found when reading; a Context Builder will annotate texts with the source of information for the next reader; and reference works will be enriched by Context Provider to show where the names or topics were mentioned in texts. An international collaboration between the University of California, Berkeley, and the Queen's University, Belfast will develop these tools for texts relating to Ireland

Document theory

Document theory examines the concept of a document and how it can serve with other concepts to understand communication, documentation, information, and knowledge. Knowledge organization itself is in practice based on die arrangement of documents representing concepts and knowledge. The word "document" commonly refers to a text or graphic record, but, in a semiotic perspective, non-graphic objects can also be regarded as signifying and, therefore, as documents. The steady increase in the variety and number of documents since prehistoric times enables the development of communities, the division of labor, and reduction of the constraints of space and time. Documents arc related to data, facts, texts, works, information, knowledge, signs, and other documents. Documents have physical (material), cognitive, and social aspects