Local equilibrium in bird flocks

http://www.nature.com/nphys/journal/vaop/ncurrent/pdf/nphys3846.pdf

Abstract

The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

Interested in Randomized Linear Algebra? Great resource in the link below:

http://arxiv.org/abs/1608.04481?utm_content=bufferdffab&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

http://www.inference.phy.cam.ac.uk/itprnn_lectures/ درس آنلاین Information Theory, Pattern Recognition, and Neural Networks

https://www.washingtonpost.com/news/wonk/wp/2016/08/19/the-secret-mesmerizing-math-of-taffy-pulling/?postshare=2491471645146181&tid=ss_tw-bottom

Inside the epic quest for a more perfect taffy - A story of topology, dynamical systems & hypnotic machines

#سلسله_سمینارهای_هفتگی گروه سیستم های پیچیده شهید بهشتی
«بررسی مدل ASEP در شار ترافیکی»
ساسان ابراهیم آبادی، دانشجوی ارشد سیستم های پیچیده، دانشگاه شهیدبهشتی
یکشنبه 31 مرداد، ساعت 10:30 کلاس 1 دانشکده فیزیک

حضور در این جلسات برای همه ی فعالان و علاقمندان آزاد است.
ضمنا علاقه مندان می توانند برای ارائه موضوعات خود به ادمین پیام داده و یا در جلسه بصورت حضوری مطرح نمایند.

http://braineng.ipm.ac.ir/job.jsp گذراندن پایان نامه دانشجوی دکتری در مرکز مهندسی عصبی پژوهشگاه دانشهای بنیادی

Job description: Brain engineering research center is providing an excellent opportunity for PhD students who are interested in systems/cognitive neuroscience for performing his/her research dissertations at IPM. The lab is broadly interested in vision and neural engineering with a specific focus on electrophysiological studies on primate vision, computational neuroscience, and visual prosthesis. The candidates should be a PhD student in electronic and computer engineering or basic science such as mathematics and neuroscience.

on the Wonderful World of #Random_Walks

http://faculty.washington.edu/hqian/amath572/Montroll.pdf

Postdoctoral Research Positions: Brain engineering research center at IPM/Tehran is accepting applications for 3-year postdoctoral research fellows starting September 2016. The lab is broadly interested in vision and neural engineering with a specific focus on electrophysiological studies on primate vision, computational neuroscience and visual prosthesis. The candidates should have a Ph.D. degree in neuroscience, electronic engineering, biomedical engineering, computer engineering or related field and will be involved in a collaboration with the State University of New York, College of Optometry. http://braineng.ipm.ac.ir/job_postDoc.jsp

WHY CITIES KEEP GROWING, CORPORATIONS AND PEOPLE ALWAYS DIE, AND LIFE GETS FASTER, by Geoffrey West

https://www.edge.org/conversation/geoffrey_west-why-cities-keep-growing-corporations-and-people-always-die-and-life-gets

Postdoctoral positions available

http://xn.unamur.be/

Simon's fundamental rich-gets-richer model entails a dominant first-mover advantage



https://arxiv.org/abs/1608.06313

Brian #Josephson (2016)

Lecture and Discussion: #Emergent #Self-Organising Activity as the true #foundation of #Reality

http://www.mediatheque.lindau-nobel.org/videos/36145/lecture-emergent-self-organising-activity

Abstract

The presumptions underlying quantum mechanics make it relevant to a limited range of situations only1; furthermore, its statistical character means that it provides no answers to the question ‘what is really going on?’. In line with Barad’s discussions of the way quantum measurements introduce definiteness into previously indefinite situations, it is hypothesised that the underlying mechanics has parallels with human activities. We are led to consider a subtle type of order, different from those commonly encountered in the discipline of physics, and yet comprehensible in terms of concepts considered by Barad and Yardley such as oppositional dynamics or ‘intra-actions’2. The emergent organisation implies that nature is no longer fundamentally meaningless.

We are led to consider a subtle type of order, different from those commonly encountered in the discipline of physics, and yet comprehensible in terms of concepts considered by Barad and Yardley such as oppositional dynamics or ‘intra-actions’. The emergent organisation implies that nature is no longer fundamentally meaningless.

NB: the slides for this lecture are available separately at
http://www.tcm.phy.cam.ac.uk/~bdj10/Documents/Lindau2016-slides.pdf.

Clarifications added after lecture: agencies can be viewed as dynamical systems, so we are dealing with models involving interacting dynamical systems. The 'congealing of agencies' to whch Barad refers can equated to the presence of regulatory mechanisms restricting the range of possibilities open to the agencies concerned.

Lecture Notes on Finite Element Methods for Partial Differential Equations

Endre Suli

Mathematical Institute, University of Oxford

http://people.maths.ox.ac.uk/suli/fem.pdf