Visual animation of LOTOS using SOLVE (extended version)

SOLVE (Specification using an Object-based, LOTOS-defined, Visual language) is designed to allow formal requirements capture, particularly for interactive systems. The SOLVE language is object-based, and formally defined using LOTOS (Language Of Temporal Ordering Specification). SOLVE is also a set of software tools that allow direct visual animation of systems specified in this language. Communicating objects control onscreen icons that can be manipulated directly by the user. Animation is supported by translating a SOLVE specification automatically into a LOTOS specification, and then simulating this using standard LOTOS tools. A VCR (Video Cassette Recorder) clock controller is used to illustrate the SOLVE approach. A further application is embodied in the XDILL tool that supports requirements specification and animation of digital logic circuits. The architecture of the SOLVE toolset is described

Specification and Animation of Reactive Systems

SOLVE (Specification using an Object-based, LOTOS-defined, Visual language) is designed to allow formal requirements capture, particularly for reactive systems. The SOLVE language is object-based, and formally defined using LOTOS (Language Of Temporal Ordering Specification). SOLVE is supported by tools that allow direct visual animation of systems specified in this language. Animation is supported by translating a SOLVE specification automatically into a LOTOS specification, and then graphically simulating this. A further application is embodied in the XDILL tool that supports requirements specification and visual animation of digital logic circuits. Several illustrative SOLVE examples are given

The N-Body Problem in LOTOS

It is shown how the classical n-body problem in mechanics can be generalised and formalised in LOTOS. A number of variants are produced by instantiation of the specification framework. These include Newton’s cradle, gas motion, the ‘game of life’, an orrery, a space game, an air traffic simulation and a sailing race. It is shown how these are derived from the generic framework using a configuration tool. The resulting LOTOS specifications are simulated automatically to graphically animate the system behaviour

Verification of gyrokinetic particle simulation of current-driven instability in fusion plasmas. I. Internal kink mode

The gyrokinetic toroidal code (GTC) capability has been extended for simulating internal kink instability with kinetic effects in toroidal geometry. The global simulation domain covers the magnetic axis, which is necessary for simulating current-driven instabilities. GTC simulation in the fluid limit of the kink modes in cylindrical geometry is verified by benchmarking with a magnetohydrodynamic eigenvalue code. Gyrokinetic simulations of the kink modes in the toroidal geometry find that ion kinetic effects significantly reduce the growth rate even when the banana orbit width is much smaller than the radial width of the perturbed current layer at the mode rational surface

Comparing eDNA metabarcoding and conventional pelagic netting to inform biodiversity monitoring in deep ocean environments

The performance of environmental DNA (eDNA) metabarcoding has rarely been evaluated against conventional sampling methods in deep ocean mesopelagic environments. We assessed the biodiversity patterns generated with eDNA and two co-located conventional methods, oblique midwater trawls and vertical multinets, to compare regional and sample-level diversity. We then assessed the concordance of ecological patterns across water column habitats and evaluated how DNA markers and the level of sampling effort influenced the inferred community. We found eDNA metabarcoding characterized regional diversity well, detecting more taxa while identifying similar ecological patterns as conventional samples. Within sampling locations, eDNA metabarcoding rarely detected taxa across more than one replicate. While more taxa were found in eDNA than oblique midwater trawls within sample stations, fewer were found compared to vertical multinets. Our simulations show greater eDNA sampling effort would improve concordance with conventional methods. We also observed that using taxonomic data from multiple markers generated ecological patterns most similar to those observed with conventional methods. Patterns observed with Exact Sequence Variants were more stable across markers suggesting they are more powerful for detecting change. eDNA metabarcoding is a valuable tool for identifying and monitoring biological hotspots but some methodological adjustments are recommended for deep ocean environments