Sub-nanosecond synchronization implementation in pure Xilinx Kintex-7 FPGA

White Rabbit (WR) provides high-performance synchronization with sub-nanosecond accuracy and picoseconds precision, and it has been included in the new High Accuracy Default PTP Profile in the IEEE 1588-2019. As an open-source project, WR Precision Time Protocol (WR-PTP) core has been implemented in different FPGA platforms with dedicated clock circuits. This paper presents a novel approach to achieve the WR function in Xilinx Kintex-7 FPGA depending on the on-chip resource. This approach could achieve sub-nanosecond accuracy and tens of picoseconds precision, simplifying WR devices' hardware design and making it possible to port the WR PTP core to many mature hardware platforms.

The non-psychopath's guide to managing an open source project

Respect your staff, learn from others, and know when to let go.

Simulated Sky

For centuries, the rich nocturnal environment of the starry sky could be modelled only by analogue tools such as paper planispheres, atlases, globes and numerical tables. The immersive sky simulator of the twentieth century, the optomechanical planetarium, provided new ways for representing and teaching about the sky, but the high construction and running costs meant that they have not become common. However, in recent decades, “desktop planetarium programs” running on personal computers have gained wide attention. Modern incarnations are immensely versatile tools, mostly targeted towards the community of amateur astronomers and for knowledge transfer in transdisciplinary research. Cultural astronomers also value the possibilities they give of simulating the skies of past times or other cultures. With this paper, we provide an extended presentation of the open-source project Stellarium, which in the last few years has been enriched with capabilities for cultural astronomy research not found in similar, commercial alternatives.

Jupyter: Thinking and Storytelling with Code and Data

Project Jupyter is an open-source project for interactive computing widely used in data science, machine learning, and scientific computing. We argue that even though Jupyter helps users perform complex, technical work, Jupyter itself solves problems that are fundamentally human in nature. Namely, Jupyter helps humans to think and tell stories with code and data. We illustrate this by describing three dimensions of Jupyter: interactive computing, computational narratives, and the idea that Jupyter is more than software. We illustrate the impact of these dimensions on a community of practice in Earth and climate science.

Jupyter: Thinking and Storytelling with Code and Data

Project Jupyter is an open-source project for interactive computing widely used in data science, machine learning, and scientific computing. We argue that even though Jupyter helps users perform complex, technical work, Jupyter itself solves problems that are fundamentally human in nature. Namely, Jupyter helps humans to think and tell stories with code and data. We illustrate this by describing three dimensions of Jupyter: interactive computing, computational narratives, and the idea that Jupyter is more than software. We illustrate the impact of these dimensions on a community of practice in Earth and climate science.