Using curvature information in haptic shape perception of 3D objects

Are humans able to perceive the circularity of a cylinder that is grasped by the hand? This study presents the findings of an experiment in which cylinders with a circular cross-section had to be distinguished from cylinders with an elliptical cross-section. For comparison, the ability to distinguish a square cuboid from a rectangular cuboid was also investigated. Both elliptical and rectangular shapes can be characterized by the aspect ratio, but elliptical shapes also contain curvature information. We found that an elliptical shape with an aspect ratio of only 1.03 could be distinguished from a circular shape both in static and dynamic touch. However, for a rectangular shape, the aspect ratio needed to be about 1.11 for dynamic touch and 1.15 for static touch in order to be discernible from a square shape. We conclude that curvature information can be employed in a reliable and efficient manner in the perception of 3D shapes by touch

Consistency and Availability in Microservice Architectures

For the most part, the first instances of microservice architectures have been deployed for the benefit of the so-called Internet-scale companies in contexts where availability is a critical concern. Their success in this context, along with their promise to be more agile than competing solutions in adapting to changing needs, soon attracted the interest of very diverse classes of business domains characterized by different priorities with respect to non-functional requirements. Microservices embraced this challenge, showing a unique ability to allow for a plethora of solutions, enabling developers to reach the trade-off between consistency and availability that better suits their needs. From a design point of view this translates into a vast solution space. While this can be perceived as an opportunity to enjoy greater freedom with respect to other architectural styles it also means that finding the best solution for the problem at hand can be complex and it is easier to incur in errors that can put a whole project at risk. In this paper we review some possible solutions to address common problems that arise when adopting microservices and we present strategies to address consistency and availability; we also discuss the impact these strategies have on the design space