Motion Invariance in Visual Environments

The puzzle of computer vision might find new challenging solutions when we realize that most successful methods are working at image level, which is remarkably more difficult than processing directly visual streams, just as happens in nature. In this paper, we claim that their processing naturally leads to formulate the motion invariance principle, which enables the construction of a new theory of visual learning based on convolutional features. The theory addresses a number of intriguing questions that arise in natural vision, and offers a well-posed computational scheme for the discovery of convolutional filters over the retina. They are driven by the Euler-Lagrange differential equations derived from the principle of least cognitive action, that parallels laws of mechanics. Unlike traditional convolutional networks, which need massive supervision, the proposed theory offers a truly new scenario in which feature learning takes place by unsupervised processing of video signals. An experimental report of the theory is presented where we show that features extracted under motion invariance yield an improvement that can be assessed by measuring information-based indexes.Comment: arXiv admin note: substantial text overlap with arXiv:1801.0711

Some Observations on the Text of šayḫ Hāšim’s Fatḥ al-raḥmānī

The paper focuses on the text of šayḫ Hāšim’s Fatḥ al-raḥmānī, a famous work of the Arabic literature of Harär, analyzing its so far known manuscript tradition

Haggai Erlich: Saudi Arabia and Ethiopia: Islam, Christianity and Politics Entwined

  Review  

Proceedings of the ‘19th International Conference of Ethiopian Studies: Ethiopia – Diversity and Interconnections through Space and Time’. Warsaw, Poland, August 24–28, 2015: Panel on Islamic Literature in Ethiopia: New Perspectives of Research

Conference Repor

Ulrich Braukämper: Islamic History and Culture in Southern Ethiopia. Collected Essays

Review  

Contemporary and Historical Muslim Scholars as Portrayed by the Ethiopian Islamic Press in the 1990’s

The article aims at giving some information about Ethiopian Muslim scholars of the past century, so to enhance our general knowledge of Ethiopian Islam, and, moreover, to contribute to a better prosopographical understanding of the Muslim presence in Ethiopia. In this endeavour, it explores the data scattered in Ethiopian Islamic periodical press, which flourished in that country after the fall of the Derg regime in 1991. In particular, the monthly magazine Bilal, which contains in almost every issue a biographical note devoted to some learned man of the recent past, is used to collect material on the scholars. Biographical articles in Amharic and Arabic which appeared in the magazine are summarized and commented upon