Data

Vol. 9 No. 8 – August 2011

Data

Verification of Safety-critical Software

Avionics software safety certification is achieved through objective-based standards.

Avionics software has become a keystone in today's aircraft design. Advances in avionics systems have reduced aircraft weight thereby reducing fuel consumption, enabled precision navigation, improved engine performance, and provided a host of other benefits. These advances have turned modern aircraft into flying data centers with computers controlling or monitoring many of the critical systems onboard. The software that runs these aircraft systems must be as safe as we can make it.

by B. Scott Andersen, George Romanski

The World According to LINQ

Big data is about more than size, and LINQ is more than up to the task.

Programmers building Web- and cloud-based applications wire together data from many different sources such as sensors, social networks, user interfaces, spreadsheets, and stock tickers. Most of this data does not fit in the closed and clean world of traditional relational databases. It is too big, unstructured, denormalized, and streaming in realtime. Presenting a unified programming model across all these disparate data models and query languages seems impossible at first. By focusing on the commonalities instead of the differences, however, most data sources will accept some form of computation to filter and transform collections of data.

by Erik Meijer

Abstraction in Hardware System Design

Applying lessons from software languages to hardware languages using Bluespec SystemVerilog

The history of software engineering is one of continuing development of abstraction mechanisms designed to tackle ever-increasing complexity. Hardware design, however, is not as current. For example, the two most commonly used HDLs date back to the 1980s. Updates to the standards lag behind modern programming languages in structural abstractions such as types, encapsulation, and parameterization. Their behavioral semantics lag even further. They are specified in terms of event-driven simulators running on uniprocessor von Neumann machines.

by Rishiyur S. Nikhil

How to Improve Security?

It takes more than flossing once a year.

We recently had a security compromise at work, and now the whole IT department is scrambling to improve security. One problem this whole episode has brought to light is that so much security advice is generic. It's like being told to lock your door when you go out at night, without saying what kind of lock you ought to own or how many are enough to protect your house. I think by now most people know they need to lock their doors, so why aren't there more specific guidelines for securing systems?

by George Neville-Neil