Unreliable numbers: error and harm induced by bad design can be reduced by better design

Number entry is a ubiquitous activity and is often performed in safety- and mission-critical procedures, such as healthcare, science, finance, aviation and in many other areas. We show that Monte Carlo methods can quickly and easily compare the reliability of different number entry systems. A surprising finding is that many common, widely used systems are defective, and induce unnecessary human error. We show that Monte Carlo methods enable designers to explore the implications of normal and unexpected operator behaviour, and to design systems to be more resilient to use error. We demonstrate novel designs with improved resilience, implying that the common problems identified and the errors they induce are avoidable

Visualizing Computer Architecture Simulations

Contents 1 Introduction 5 1.1 Simulation of Computer Architectures : : : : : : : : : : : : : 6 1.2 Visual Interactive Simulation : : : : : : : : : : : : : : : : : : 7 1.3 Related work : : : : : : : : : : : : : : : : : : : : : : : : : : : 10 1.3.1 The Data Diffusion Machine : : : : : : : : : : : : : : 10 1.3.2 Proteus: a parallel--architecture simulator : : : : : : : 12 1.4 Discussion : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 13 2 Pearl 15 2.1 Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : 15 2.2 Objects and communication : : : : : : : : : : : : : : : : : : : 16 2.3 The virtual clock : : : : : : : : : : : : : : : : : : : : : : : : : 17 2.4 The topology file : : : : : : : : : : : : : : : : : : : : : : : : : 18 2.5 The output of the simulation : :

Porting the AVS/Express scientific visualization software to Cray XT4

Remote scientific visualization, where rendering services are provided by larger scale systems than are available on the desktop, is becoming increasingly important as dataset sizes increase beyond the capabilities of desktop workstations. Uptake of such services relies on access to suitable visualization applications and the ability to view the resulting visualization in a convenient form. We consider five rules from the e-Science community to meet these goals with the porting of a commercial visualization package to a largescale system. The application uses message-passing interface (MPI) to distribute data among data processing and rendering processes. The use of MPI in such an interactive application is not compatible with restrictions imposed by the Cray system being considered. We present details, and performance analysis, of a new MPI proxy method that allows the application to run within the Cray environment yet still support MPI communication required by the application. Example use cases from materials science are considered. © 2011 The Royal Society