Akio Toyoda is correcting course at Toyota Group companies in Japan amid a rash of misconduct that has embarrassed the world's biggest carmaker and eroded public trust at home.

The Toyota Motor Corp. chairman summoned the leaders of the 17 group affiliates to a morning meeting Tuesday in Nagoya and outlined a new Global Vision to refocus their priorities.

Toyoda told them that the Toyota Group has lost sight of its founding principles. He urged a back-to-basics shift, returning agency to front-line workers and concentrating more on product.

Toyota Motor said on Monday it is urging the owners of 50,000 older U.S. vehicles to get immediate recall repairs because an air bag inflator could explode and potentially kill motorists.

The Japanese automaker said the "Do Not Drive" advisory covers some 2003-2004 model year Corolla, 2003-2004 Corolla Matrix, and 2004-2005 RAV4s with Takata air bag inflators.

Shape memory objects are what some would term “4D printing”. The idea is that objects can take different forms once they are produced. There will be a trigger to make this change, and typically it’s the application of heat or energy.

There are plenty of such objects in use today, but almost all are produced using conventional techniques instead of 3D printing. One of the many reasons for that is the expense of making specialized resins.