Type Classes for Lightweight Substructural Types

Linear and substructural types are powerful tools, but adding them to standard functional programming languages often means introducing extra annotations and typing machinery. We propose a lightweight substructural type system design that recasts the structural rules of weakening and contraction as type classes; we demonstrate this design in a prototype language, Clamp. Clamp supports polymorphic substructural types as well as an expressive system of mutable references. At the same time, it adds little additional overhead to a standard Damas-Hindley-Milner type system enriched with type classes. We have established type safety for the core model and implemented a type checker with type inference in Haskell.Comment: In Proceedings LINEARITY 2014, arXiv:1502.0441

Cross-disciplinary Teaching of both Computer Forensics Students and Law Students Using Peer-Assessment in a Simulated Expert Witness Scenario

This paper describes a novel initiative of the Computing and Information Systems (CIS) Dept in conjunction with the Law Dept at the University of Greenwich. Postgraduate CIS computer forensics students, as part of their assessment, present their findings from a forensics investigation in front of a lecturer and up to five law students in a simulated expert witness testimony scenario. The law students are permitted to ask questions of the computer forensics students and eventually to give their assessment of the student’s witness evidence and presentation. This approach was devised to encompass several pertinent pedagogic issues. Firstly, it is cross-disciplinary, combining as it does, input from two very different departments – an initiative that brings together not only students but also staff who would not otherwise meet. Secondly, it involves the use of practical social/professional skills for both sets of students, as the computer forensics students must present their findings with the skills required of an expert witness in a court setting while the law students must act as cross-examining counsel. Thirdly, this exercise involves the law students assessing the performance of the computer forensics students – an application of peer-assessment that heightens the involvement of both sets of students. Lastly, both sets of students are themselves graded, the computer students by their own forensics lecturer and the law students by their law lecturer, according to their performance in this exercise. The findings from questionnaires sent out to both computer and law students were extremely positive. Both sets felt that they had benefited from the experience and that it would aid their further studies and professional development in their respective areas. It is the opinion of the C-SAFE forensics-law collaborative team that this approach represents an educational innovation in its use of cross-disciplinary problem-solving and peer-assessment in a growing and increasingly significant domain worldwide (cyber forensics)

OPAAS: a web server for optimal, permuted, and other alternative alignments of protein structures

The large number of experimentally determined protein 3D structures is a rich resource for studying protein function and evolution, and protein structure comparison (PSC) is a key method for such studies. When comparing two protein structures, almost all currently available PSC servers report a single and sequential (i.e. topological) alignment, whereas the existence of good alternative alignments, including those involving permutations (i.e. non-sequential or non-topological alignments), is well known. We have recently developed a novel PSC method that can detect alternative alignments of statistical significance (alignment similarity P-value <10(−5)), including structural permutations at all levels of complexity. OPAAS, the server of this PSC method freely accessible at our website (), provides an easy-to-read hierarchical layout of output to display detailed information on all of the significant alternative alignments detected. Because these alternative alignments can offer a more complete picture on the structural, evolutionary and functional relationship between two proteins, OPAAS can be used in structural bioinformatics research to gain additional insight that is not readily provided by existing PSC servers

Methodology for predicting explosion risk around underground coal mine openings towards developing exclusion zones

The risk of explosions in coal mines is an important subject that requires a comprehensive understanding of explosion dynamics, mining operations, and mining safety. A high level of knowledge is now available in the field of gas emissions, gas, and coal dust explosions in underground mines. However, not sufficient attention has been given to the potential risks associated with explosive forces expelled through the mine opening and resulting in injuries and fatalities to personnel (underground and at the mine portal) and catastrophic infrastructure damage in proximity to the mine opening on the surface. This paper presents a methodology for predicting explosion risk around the coal mine openings (drifts, shafts, boreholes, etc). The proposed methodology is based on establishing an empirical relationship between the parameters of blast overpressure waves emitting from mine entries and the radial distance at an azimuth angle for the various magnitude of methane or coal dust explosions. An Advanced Blast Simulator with the cross-sectional dimensions of 0.3 m x 0.3 m has been manufactured for this study to conduct a series of experiments simulating blast waves exiting a portal entry and propagating over an outside mine site terrain. An array of pressure sensors is placed along the centreline and at several azimuth angles of the blast simulator and along a surface representing a highwall to record the characteristics of blast overpressure waves. Computational Fluid Dynamics modelling of blast wave propagation outside of mine openings is used to correlate the experimental results and scale them up to full-scale dimensions of the coal mine infrastructure and mine sites. A procedure to estimate the lethal ranges of projectiles from mine entries using existing guidelines from a military ammunition storage reference manual is described. The outcome of this research will support the development of scientifically defined exclusion zones around surface mine openings that could be affected by an underground explosion event

Patterns of genomic and phenomic diversity in wine and table grapes.

Grapes are one of the most economically and culturally important crops worldwide, and they have been bred for both winemaking and fresh consumption. Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world's largest grape gene banks, the grape germplasm collection of the United States Department of Agriculture. We find that phenological events throughout the growing season are correlated, and quantify the marked difference in size between table and wine grapes. By pairing publicly available historical phenotype data with genome-wide polymorphism data, we identify large effect loci controlling traits that have been targeted during domestication and breeding, including hermaphroditism, lighter skin pigmentation and muscat aroma. Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited, whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions. We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries. Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes

Defining explosion risk exclusion zones around coal mine openings in emergency situations

The risk of explosions in coal mines is an important subject that requires a comprehensive understanding of explosion dynamics, mining operations, and mining safety. Recent spontaneous combustion events in New South Wales (NSW) and Queensland have resulted in mine evacuations due to a Trigger Action Response Plan (TARP) being activated at the evacuation level. A sound basis is required for defining the high-risk working zones, mine operational exclusion zones for both emergency activities and mine design considerations, and public exclusion zones during emergency situations. This paper presents a methodology for predicting and defining explosion risk around the coal mine portals developed using Computational Fluid Dynamics (CFD) and experimental results from an advanced blast simulator simulating blast waves exiting a portal entry and propagating over an outside mine site terrain. The methodology can be applied to generate exclusion zones that account for the effects of blast waves emanating from the mine openings. A worked example is provided at the end of the paper as a reference to engineers for the development of mine exclusion zones from blast wave effects