Some observations on washout of brown trout (Salmo trutta L.) eggs in Teesdale streams

Brown trout (Salmo trutta) in Teesdale lay their eggs in the streambed gravels in the Autumn, here the eggs slowly develop to emerge as young fry in the Spring. Whilst the eggs are in the gravel they are vulnerable to displacement by high water velocities. Eggs removed in this way are not thought to remain viable since they are very susceptible to death through physical shock - especially in the earlier stages of development. Streams in Teesdale are known to be amongst the most flashy in England and thus are good sites in which to study egg washout. Three field sites were used for the study of egg washout in Teesdale - Great Eggleshope, Thorsgill and Carl becks. This report describes preliminary studies of a varied nature into this subject from which an attempt is made to assess the importance of egg washout to the survival of brown trout in Teesdale

When images work faster than words: The integration of content-based image retrieval with the Northumbria Watermark Archive

Information on the manufacture, history, provenance, identification, care and conservation of paper-based artwork/objects is disparate and not always readily available. The Northumbria Watermark Archive will incorporate such material into a database, which will be made freely available on the Internet providing an invaluable resource for conservation, research and education. The efficiency of a database is highly dependant on its search mechanism. Text based mechanisms are frequently ineffective when a range of descriptive terminologies might be used i.e. when describing images or translating from foreign languages. In such cases a Content Based Image Retrieval (CBIR) system can be more effective. Watermarks provide paper with unique visual identification characteristics and have been used to provide a point of entry to the archive that is more efficient and effective than a text based search mechanism. The research carried out has the potential to be applied to any numerically large collection of images with distinctive features of colour, shape or texture i.e. coins, architectural features, picture frame profiles, hallmarks, Japanese artists stamps etc. Although the establishment of an electronic archive incorporating a CBIR system can undoubtedly improve access to large collections of images and related data, the development is rarely trouble free. This paper discusses some of the issues that must be considered i.e. collaboration between disciplines; project management; copying and digitising objects; content based image retrieval; the Northumbria Watermark Archive; the use of standardised terminology within a database as well as copyright issues

Survival of intragravel stages of brown trout (Salmo trutta L.) in Teesdale

A study has been undertaken on several streams in Teesdale (UK)in order to examine survival rates of intragravel stages of brown trout and the factors influencing survival. Although all the becks contained brown trout spawning areas, some were utilised by more spawning trout than others. The best spawning sites as judged by this criterion were Thorsgill and Great Eggleshope becks where the research effort was therefore concentrated. There were two different spawning areas in Eggleshope, namely Great Eggleshope beck itself and Great Eggleshope spring fed tributary (Esft), data from these two areas are analysed separately in most parts of the text

Events in Property Patterns

A pattern-based approach to the presentation, codification and reuse of property specifications for finite-state verification was proposed by Dwyer and his collegues. The patterns enable non-experts to read and write formal specifications for realistic systems and facilitate easy conversion of specifications between formalisms, such as LTL, CTL, QRE. In this paper, we extend the pattern system with events - changes of values of variables in the context of LTL.Comment: 14 pages, 3 figure

Information collected in Teesdale concerning free-swimming stages of brown trout (Salmo trutta L.)

During 1978 and 1979, electrofishing surveys were made in Teesdale - both to provide background information for ecological work on the streams, and to provide data so that the influence of discharge regime on the fish population densities could be examined. The discharge regimes of the different streams were compared using the Base Flow Index (BFI) as developed by the Institute of Hydrology. (PDF contains 30 pages

HSF(C): A Software Verifier Based on Horn Clauses

Abstract. HSF(C) is a tool that automates verification of safety and liveness properties for C programs. This paper describes the verification approach taken by HSF(C) and provides instructions on how to install and use the tool. 1 Verification Approach HSF(C) is a tool for verification of C programs based on predicate abstraction and refinement following the counterexample-guided abstraction refinement (CE-GAR) paradigm [4]. There are a number of successful tools [1, 7, 5, 10, 2] based on abstraction refinement. We give here a brief description of our verification algorithm; interested readers can find more details about the underlying theory behind our implementation in [10, 6]. The algorithm used in HSF(C) is a generalization of the CEGAR scheme that deals with Horn-like clauses instead of transition systems/programs with procedures. We use Horn clauses to represent both the program to be verified and the proof rule used for verification, i.e., safety checking for programs wit

Decoherence of a Superposition of Macroscopic Current States in a SQUID

We show that fundamental conservation laws mandate parameter-free mechanisms of decoherence of quantum oscillations of the superconducting current between opposite directions in a SQUID -- emission of phonons and photons at the oscillation frequency. The corresponding rates are computed and compared with experimental findings. The decohering effects of external mechanical and magnetic noise are investigated

Compile-Time Analysis and Specialization of Clocks in Concurrent Programs

Clocks are a mechanism for providing synchronization barriers in concurrent programming languages. They are usually implemented using primitive communication mechanisms and thus spare the programmer from reasoning about low-level implementation details such as remote procedure calls and error conditions. Clocks provide flexibility, but programs often use them in specific ways that do not require their full implementation. In this paper, we describe a tool that mitigates the overhead of general-purpose clocks by statically analyzing how programs use them and choosing optimized implementations when available. We tackle the clock implementation in the standard library of the X10 programming language—a parallel, distributed object-oriented language. We report our findings for a small set of analyses and benchmarks. Our tool only adds a few seconds to analysis time, making it practical to use as part of a compilation chain

SMT-based Model Checking for Recursive Programs

We present an SMT-based symbolic model checking algorithm for safety verification of recursive programs. The algorithm is modular and analyzes procedures individually. Unlike other SMT-based approaches, it maintains both "over-" and "under-approximations" of procedure summaries. Under-approximations are used to analyze procedure calls without inlining. Over-approximations are used to block infeasible counterexamples and detect convergence to a proof. We show that for programs and properties over a decidable theory, the algorithm is guaranteed to find a counterexample, if one exists. However, efficiency depends on an oracle for quantifier elimination (QE). For Boolean Programs, the algorithm is a polynomial decision procedure, matching the worst-case bounds of the best BDD-based algorithms. For Linear Arithmetic (integers and rationals), we give an efficient instantiation of the algorithm by applying QE "lazily". We use existing interpolation techniques to over-approximate QE and introduce "Model Based Projection" to under-approximate QE. Empirical evaluation on SV-COMP benchmarks shows that our algorithm improves significantly on the state-of-the-art.Comment: originally published as part of the proceedings of CAV 2014; fixed typos, better wording at some place