I gave a keynote talk on “Putting Computing on a Strict Diet with Energy-Proportionality” at the XXIX Conference on Design of Circuits and Integrated Systems, held in Madrid on 26-28th November 2014.
The abstract of the talk can be found in the conference programme:
http://www.cei.upm.es/dcis/wp-content/uploads/2014/10/DCIS_2014_program.pdf
The slides of the talk can be found here:
http://async.org.uk/Alex.Yakovlev/Yakovlev-DCIS2014-Keynote-final.pdf
In the last two months we have had two fascinating lectures in our NEMIG series:
The Time Domain, Superposition, and How Electromagnetics Really Works – Dr. Hans Schantz – 14 November 2014
http://async.org.uk/Hans-Schantz.html
Twists & Turns of the Fascinating World of Electromagnetic Waves – Prof. Steve Foti – 12th December 2014
http://async.org.uk/SteveFoti.html
These links contain links to the abstracts and videos of these lectures, as well as the bios of the speakers.
Alex Yakovlev
10th October 2014
I think I have recently reached better understanding of the electromagnetics of physical objects according to Ivor Catt, David Walton, and … surprise, surprise … Oliver Heaviside!
I was interested in Catt and Walton’s derivations of the transients (whose envelopes are exponential or sine/cosine curves) as sums of series of steps. I have recently been re-visiting their EM book (Ivor Catt’s “Electromagnetics 1” – see http://www.ivorcatt.co.uk/em.htm ).
I am really keen to understand all this ‘mechanics’ better as it seems that I am gradually settling with the idea of the world being quantised by virtue of energy currents being trapped between some reflection points, and the continuous pictures of the transients are just the results of some step-wise processes.
I deliberately use word ‘quantised’ in the above because I tend to think that ‘quantisation’ and ‘discretisation’ are practically (in physical sense; mathematicians may argue of course because they may add some abstract notion to these terms) synonyms. I’ll try to explain my understanding below.
Let’s see what happens with the TEM as it works in a transmission line with reflection. We have a series of steps in voltage which eventually form an exponential envelope. If we examine these steps, they show discrete sections in time and amplitude. The values of time sections between these steps are determined by the finite and specific characteristics of the geometry of the transmission line and the properties of the (dielectric) medium. The value of the amplitude levels between these steps is determined by the electrical properties of the line and the power level of the source.
So, basically, these discrete values associated with the energy entrapment in the transmission line (TL) are determined by the inherent characteristics of the matter and the energetic stimulus.
If we stimulated the TL with periodic changes in the energy current, we could observe the periodic process with discretised values in those steps – the envelope of which could be a sequence of charging and discharging exponentials.
I suppose if we set up a transmission line (which is largely capacitive in the above) with an inductance, so we’ll have the LC oscillator; this would produce a periodic, similarly step-wise, discretised process whose envelope will be a sine wave.
Now, if we analyse such a system in its discretised (rather than enveloped) form, we, if we want, could produce some sort of histogram showing the distribution of how much time the object in which we trap energy current, spends in what level of amplitude (we could even assign specific energy levels). Now we can call such an object a “Quantum Object”. Why not? I guess the only difference between our “quantum object” and ones that Quantum Physicists are talking about would be purely mathematical. We know the object well and our characterisation of the discretised process is deterministic, but they don’t know their discretised process sufficiently well and so they put probabilities.
If the above makes any sense, may I then make some hypotheses?
We live in the world that has finite size objects of matter, however large or small they are. These objects have boundaries. The boundaries act as reflection points on the way of the energy current. Hence associated with these objects and boundaries we have entrapments of energy. These entrapments, due to reflections give rise to discretisation in time and level. The grains of our (discretised) matter can be quite small so the entrapments can be very small and we cannot easily measure these steps in their sequences, but rather characterise by some integrative measurements (accumulate and average them – like in luminescence), hence at some point we end up being probabilistic.
One more thing that bothers me is associated with the verticality of steps and their slopes.
Let’s look at the moment when we change the state of a reed-switch or pull up the line to Vdd or down GND. The time with which this transition takes place is also non-zero. I.e., even if the propagation of the change is with the speed of light, modulo the epsilon and mu of the medium, i.e. with finite time to destination, the transition of the voltage level must also be associated with some propagation of the field, or forces, inside the reed-switch or in the transistor, respectively, that pulls the line up or down. Clearly that time-frame is much smaller than the time frame of propagating the energy current in the medium along the transmission line, but still it is not zero. I presume that, quite recursively, we can look at the finer granularity of this stage change and see that it is itself a step-wise process of some reflections of the energy current in that small object, the switch, and what we see as a continuous slope is actually an envelope of the step-wise process.
http://www.ncl.ac.uk/eee/about/news/item/nemig-seminar-150-years-of-maxwell-s-equations
There will shortly be a video available on htt://async.org.uk of this lecture.
John Arthur’s book on Understanding Algebraic Geometry for Electromagnetic Theory:
http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0470941634.html
14:00 – 15:00, 22nd September 2014, Room: M4.13 (CPD Room) Merz Court
Dr John Arthur FRSE FREng FinstP FIET SMIEE Trustee, James Clerk Maxwell Foundation
The talk will start with who James Clerk Maxwell was and the origins of his electromagnetic equations. It will show some of the difficulties he had with the mathematics of the day and how, from there, the original cumbersome equations were gradually shaped into the set most commonly seen today. But even now there is confusion and misunderstanding about some of the key concepts, such as questions concerning the roles and relative usefulness of D and E and, even more so, B and H. We therefore set about clarifying the essential fields. As to the usefulness, or otherwise, of magnetic poles as a concept, we investigate an alternative view of magnetism which leads to the idea of replacing two separate electromagnetic fields with just one composite field. This requires a change to the treatment of Maxwell’s equations which has some surprising benefits, as will be demonstrated, ending up with how they reduce to just one very simple equation.
Speaker’s biography: Although born and bred in Edinburgh, John Arthur took a degree in physics and mathematics at the University of Toronto before returning to complete a PhD in physics from the University of Edinburgh where he then worked for several years in post-doctoral research. Thereafter he moved from academia to industry, where he spent the greater part of his career specialising in high technology developments for communications and radar in areas covering signal processing, surface acoustic waves, microwaves and electronics. He has published a number of articles, and more recently a recent book, on electromagnetic theory. Since 2012 he has been a trustee of the James Clerk Maxwell Foundation based at 14 India Street, Edinburgh, the birthplace of James Clerk Maxwell.
One of possible strategies for differentiating some types of electronics from other types is to stage a “power-modulated competition” between them, by gradually tuning power source in different ways, for example in terms of power levels, either through voltage level or/and current level, also in dynamic sense as well. The circuits that require stable and sufficiently high level of voltage will be gradually eliminated from the race … Only those who can survive through the power dynamic range context will pass through the natural selection!
Building such a test bed is an interesting challenge by itself!
The unveiling ceremony was held on Saturday 30th August 2014 at 3pm in Paignton Cemetery. It was attended by the Mayor of Torbay, the MP for Torbay, an ex-curator of the Science Museum (representing the Institution of Engineering and Technology), the Chairman of the Torbay Civic Society, delegates from Newcastle University, representatives from Allwood and Sons the monument restorers and members of the general public. Most importantly, the ceremony was honored by the attendance of a relative of Oliver Heaviside , Alan Heather (Oliver Heaviside’s first cousin three times removed) and his wife.
At this ceremony I emphasized the fact that Heaviside who was an electrical engineer at the start of his professional life, with his work that originated in solving practical engineering problems (e.g. telegraphy and telephony), made an unprecedented impact on fundamental disciplines – mathematics and physics. This fact should be seen by many students and researchers, as well as engineers, as an inspiration to the creative process in science. Unlike the accepted “causal path”, which people often associate with applying basic science to engineering problems, the truly innovative causal path is actually reverse. On this path, one would start with the engineering problem, find a practically working solution – very often engineering intuition helps here – and then “invent” the mathematics and physics to describe the solution as a phenomenon. Heaviside’s whole life has been the following of this path, which pretty well epitomizes his famous saying “We reverse this; the current in the wire is set up by the energy transmitted through the medium around it.” (”Electrical Papers” Vol. 1, page 438, by Oliver Heaviside.). Here the engineering method acts as an driving energy and the product of this method, the scientific method, is like a current in the wire.
I am sure that Heaviside is a brilliant example that we should tell our students about when attracting them into (electrical and electronic) engineering – where they can make impact on fundamental sciences without actually being professional mathematicians or physicists. They need to be creative and imaginative!
Here is a link to our joint (Bristol & Newcastle) EPSRC project on real intermittency in power sourcing:
http://www.bristol.ac.uk/engineering/research/em/research/savvie.html
http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-007X/earlyview
On hyperbolic laws of capacitor discharge through self-timed digital loads
Alexandre Yakovlev, Alexander Kushnerov, Andrey Mokhov and Reza Ramezani
Article first published online: 1 AUG 2014 | DOI: 10.1002/cta.2010
A new model to predict the dynamic behavior of a self-timed digital system powered by a capacitor is derived. The model demonstrates the hyperbolic shape of the discharging process on the capacitor. It allows a symbolic analysis of the discharging process for complex digital loads comprised of series (stack) and parallel configurations of digital circuits. For example, for a stack configuration, non-trivial relationships between the hyperbolic discharging rates have been derived. The derivations have been validated by simulations and experiments
New book has been published in Saint Petersburg, by Professional Literature.
Marakhovsky VB, Rozenblyum LYa, Yakovlev AV. Моделирование параллельных процессов. Сети Петри. (The book is in Russian language)(Modelling Concurrent Processes. Petri nets) . Saint Petersburg: СПб: Профессиональная литература, АйТи-Подготовка (Professional Literature, www.profliteratura.ru), 2014.
The book is in the Series of Selected Titles in Computer Science. It presents a course for Systems Architects and Programmers, Systems Analysts and Designers of Complex Control Systems.
Practically any more or less complex information or control system has components that operate concurrently, in other words in parallel. This book presents methods for formal dynamical modelling of parallel asynchronous processes. Such processes can be found in various application areas, such as computations, control, interfaces, programming, robotics or artificial intelligence.
It is emphasized in this book that there is an important relationship between a structural model, which reflects static properties of the modelled system, and its dynamic (behavioural) model. This two-pronged fundamental approach is suitable at all stages of system design – specification, analysis, implementation and verification.
The book has numerous examples and exercises, which makes it a good supporting text for courses in various syllabi involving modelling information and control systems.
NEMIG Seminar: Oliver Heaviside FRS: The Man, His Work and Memorial Project
13:45 – 14:30, 4th August 2014, Room: M4.13 (CPD Room) Merz Court
A talk followed by discussion session will be held by NEMIG co-founder Christopher Spargo.
The talk will briefly outline Heaviside’s life from childhood until his death, his friendships, relations and recognitions. The talk will then proceed to discuss some of his major achievements such as the reformulation of Maxwell’s equations into today’s known form, the problem of Victorian telegraphy and Heaviside’s solution due to the development of his distributed transmission line model through to some little known aspects of his work but which have major impact. The talk will conclude with an introduction to the Heaviside Memorial Project of which the speaker is the founder and project director. Questions and discussion amongst the group afterwards are most welcome.