Protocol Techniques for Testing Radiotherapy Accelerators

The nature of radiotherapy accelerators is briefly explained. It is argued that these complex safety-critical systems need a systematic basis for testing their software. The paper describes a novel application of protocol specification and testing methods to radiotherapy accelerators. An outline specification is given in LOTOS (Language Of Temporal Ordering Specification) of the accelerator control system. It is completely infeasible to use this directly for test generation. Instead, specification inputs are restricted using annotations in a Parameter Constraint Language. This is automatically translated into LOTOS and combined with the accelerator specification. It then becomes manageable to generate tests automatically of the actual accelerator to check that it agrees with its specification according to the relation ioconf (input-output conformance). Sample input annotations, their translation to LOTOS, and the resulting test cases are described

Towards an analysis of shear suspension flows using radial basis functions

In this paper, radial basis functions are utilised for numerical prediction of the bulk properties of particulate suspensions under simple shear conditions. The suspending fluid is Newtonian and the suspended particles are rigid. Results obtained are compared well with those based on finite elements in the literature

Specification and Verification of Synchronous Hardware using LOTOS

This paper investigates specification and verification of synchronous circuits using DILL (Digital Logic in LOTOS). After an overview of the DILL approach, the paper focuses on the characteristics of synchronous circuits. A more constrained model is presented for specifying digital components and verifying them. Two standard benchmark circuits are specified using this new model, and analysed by the CADP toolset (Cæsar/Aldébaran Development Package)

Indoor measurement of photovoltaic device characteristics at varying irradiance, temperature and spectrum for energy rating

This was accepted for publication in the journal Measurement Science and Technology. The definitive published version can be found at: http://dx.doi.org/10.1088/0957-0233/21/11/115701The first three-dimensional performance matrix for use in photovoltaic (PV) energy rating is reported utilizing a novel energy rating solar simulator based on LEDs. Device characteristics are measured indoors at varying irradiance (G), temperature (T) and spectrum (E). This opens the possibility for a more accurate measurement system for energy yield prediction of PV devices, especially for devices with high spectral dependence such as wide bandgap solar cells as they take into account spectral changes in the light. The main aspects of the LED-based solar simulator used are briefly described. A measurement method is developed and detailed in the paper, which takes into account the current imperfections in the achievable spectrum. Measurement results for a crystalline silicon solar cell are used to demonstrate the measurement approach. An uncertainty analysis of the measurement system is given, resulting in an overall absolute uncertainty of 4.3% (coverage factor k = 2) in maximum power measurements at 765 W m−2 irradiance with scope for further improvements

Protocol-Inspired Hardware Testing

The relevance of protocol conformance testing techniques to hardware testing is discussed. It is shown that the ioconf (input-output conformance) approach used in protocol testing can be applied to generate tests for a synchronous hardware design using its formal specification. The generated tests are automatically applied to a circuit by a VHDL testbench, thus giving confidence that the hardware design meets its high-level formal specification. Case studies illustrate how the ideas can be applied to standard hardware verification benchmarks such as the Single Pulser and Black-Jack Dealer