Some of Leonid Rosenblum’s works

L. Ya. Rosenblum and A.V. Yakovlev.
Signal graphs: from self-timed to timed ones,
Proc. of the Int. Workshop on Timed Petri Nets,
Torino, Italy, July 1985, IEEE Computer Society Press, NY, 1985, pp. 199-207.

https://www.staff.ncl.ac.uk/alex.yakovlev/home.formal/LR-AY-TPN85.pdf

A paper establishing interesting relationship between the interleaving and true causality semantics
using algebraic lattices. It also identifies an connection between the classes of lattices and the property
of generalisability of concurrency relations (from arity N to arity N+1),
i.e. the conditions for answering the question such as,
if three actions A, B and C are all pairwise concurrent, i.e. ||(A,B), ||(A,C), and ||(B,C), are they concurrent “in three”, i.e. ||(A,B,C)?
L. Rosenblum, A. Yakovlev, and V. Yakovlev.
A look at concurrency semantics through “lattice glasses”.
In Bulletin of the EATCS (European Association for Theoretical Computer Science), volume 37, pages 175-180, 1989.

https://www.staff.ncl.ac.uk/alex.yakovlev/home.formal/lattices-Bul-EATCS-37-Feb-1989.pdf

Paper about the so called symbolic STGs, in which signals can have multiple values (which is often convenient for specifications of control at a more abstract level than dealing with binary signals) and hence in order to implement them in logic gates one needs to solve the problem of binary expansion or encoding, as well as resolve all the state coding issues on the way of synthesis of circuit implementation.

https://www.staff.ncl.ac.uk/alex.yakovlev/home.formal/async-des-methods-Manchester-1993-SymbSTG-yakovlev.pdf

Paper about analysing concurrency semantics using relation-based approach. Similar techniques are now being developed in the domain of business process modelling and work-flow analysis: L.Ya. Rosenblum and A.V. Yakovlev. Analysing semantics of concurrent hardware specifications. Proc. Int. Conf. on Parallel Processing (ICPP89), Pennstate University Press, University Park, PA, July 1989, pp. 211-218, Vol.3

https://www.staff.ncl.ac.uk/alex.yakovlev/home.formal/LR-AY-ICPP89.pdf

Моделирование параллельных процессов. Сети Петри [Текст] : курс для системных архитекторов, программистов, системных аналитиков, проектировщиков сложных систем управления / Мараховский В. Б., Розенблюм Л. Я., Яковлев А. В. – Санкт-Петербург : Профессиональная литература, 2014. – 398 с. : ил., табл.; 24 см. – (Серия “Избранное Computer Science”).; ISBN 978-5-9905552-0-4
(Серия “Избранное Computer Science”)

https://www.researchgate.net/…/Simulation-of-Concurrent-Processes-Petri-Nets.pdf

Leonid Rosenblum passes away …

Today In Miami at the age of 83 passed away a well known Russian and American automata theory scientist Leonid Rosenblum. He was my mentor and closest friend. Here is some brief information about his career. In Russian.

Леонид Яковлевич Розенблюм (5 марта 1936 г. – 2 апреля 2019 г.), канд. техн.наук, доцент – пионер мажоритарной логики, самосинхронной схемотехники, теории и применений сетей Петри в моделировании и проектировании цифровых схем и параллельных систем.В течение 20 лет, с 1960г. по 1980г., занимался с коллегами (в группе профессора В.И. Варшавского) наукой и приложениями (например, разработкой новой схемотехники и надежных бортовых компьютеров) в Вычислительном центре Ленинградского отделения Математического института им. В.А. Стеклова АН СССР.

С 1981г. по 1989 г. работал доцентом кафедры математического обеспечения и применения ЭВМ в ЛЭТИ им. В.И. Ульянова-Ленина (ныне Санкт-Петербургский государственный электротехнический университет). В 90-х годах после эмиграции в США работал адъюнкт-профессором в Бостонском университете, а также исследователем в Гарвардском университете.

Соавтор/автор пяти книг, около двух сотен различных изданий, учебных пособий, статей и обзоров, более 40 авторских свидетельств на изобретения.

Среди его учеников – профессора университетов России, Великобритании, США, Финляндии и других стран, сотрудники институтов АН Российской Федерации, таких как Институт Проблем Управления, а также известных отечественных и зарубежных компаний, таких как Intel, Cadence, Xilinx и т.д.

Леонида Яковлевича отличало врожденное свойство видеть в людях только положительные качества, помогать всем и во всем, и конечно необыкновенное чувство юмора. Эта утрата для огромного числа людей повсюду, всех кому посчастливилось его знать или слышать о нем.

Вечная память, дорогой Лека!

Leonid Yakovlevich Rosenblum (March 5, 1936 – April 2, 2019), Cand. Technical Sciences, Associate Professor – a pioneer of majority logic, self-timed circuit design, theory and applications of Petri nets in the modeling and design of digital circuits and parallel systems.

For 20 years, from 1960 to 1980, he worked with his colleagues (in the group of Professor VI Varshavsky) with science and applications (for example, developing new circuitry and reliable on-board computers) at the Computing Center of the Leningrad Branch of the Mathematical Institute. V.A. Steklov Academy of Sciences of the USSR.
From 1981 to 1989, he worked as an associate professor at the Department of Software and Computer Applications at LETI named after Ulyanov-Lenin  (now St. Petersburg State Electrotechnical University). In the 90s, after emigration to the United States, he worked as an adjunct professor at Boston University, as well as a researcher at Harvard University.
Co-author / author of five books, about two hundred different publications, textbooks, articles and reviews, more than 40 certificates of authorship for inventions.

Among his students are professors from universities in Russia, the United Kingdom, the United States, Finland and other countries, employees of institutes of the Academy of Sciences of the Russian Federation, such as the Institute of Management Problems, as well as well-known domestic and foreign companies such as Intel, Cadence, Xilinx, etc.

Leonid Yakovlevich was distinguished by the innate ability to see in people only positive qualities, to help everyone and in everything, and of course an extraordinary sense of humor. This is a great loss for a huge number of people everywhere, all who were lucky enough to know or hear about him.
Rest in peace, dear Leo!

 

On “Quantum LC circuit paradox”

One of my younger friends and co-authors, Alex Kushnerov, has just pointed out to me the following statement:

“So, there are no electric or magnetic charges in the quantum LC circuit, but electric and magnetic fluxes only….”

It is made on the following website:

https://en.m.wikipedia.org/wiki/Quantum_LC_circuit

It seems that for ‘classical theorists’ in EM and Quantum Mechanics, this effect forms a paradox, which they call “Quantum LC circuit paradox”.

Presumably, if they started with energy current in the first place, which has nothing to do with charges or currents, and then simply capture energy current in spatial forms, that manifest themselves as “capacitors” or “inductors”, they would quantize it quite comfortably in a normal deterministic and causal sense. Thus they would have the effects of LC without any necessity to go to special ‘quantum LC’.

I wrote about these ideas in my Royal Society Phil Trans paper:

Energy current and computing

And in my earlier blogs …, e.g. https://blogs.ncl.ac.uk/alexyakovlev/2014/10/

And, most importantly, that’s what Ivor Catt and his Catt Theory of EM have been trying to tell the rest of the world for more than half a century:

http://www.ivorcatt.co.uk

Talking at the AI Workshop held at the Center for AI Research (CAIR) at University of Agder, Norway

I was invited to University of Agder, in the South of Norway (in a nice town called Grimstad, famous for the presence of Henrik Ibsen and Knut Hamsun), to present my vision on what kind of hardware do we need for pervasive AI. This presentation was part of a workshop organised by Prof Ole-Christoffer Granmo, Director of CAIR, on the occasion of the grant opening of CAIR – https://cair.uia.no

In my presentation I emphasized the following points:

  • Pervasive Intelligence requires reconsidering many balances:
    – Between software and hardware
    – Between power and compute
    – Between analogand digital
    – Between design and fabrication and maintenance
  • Granulation phenomenon: Granularity of power, time, data and function
  • Main research questions:
    – Can we granulate intelligence to minimum?
    – What is the smallest level at which we can make cyber-systems learn in terms of power, time, data and function?
  • Grand challenge for pervasive hardware AI:
    To enable electronic components with an ability to learn and compute in real-life environments with real-power and in real-time
  • Research Hypothesis:
    We should design systems that are energy-modulated and self-timed, with maximally distributed learning capabilities

I put a strong hypothesis on the role of using Tsetlin Automata (Automata with Linear Tactics) for building electronics with high-granularity learning capabilities.

The key elements of the proposed approach are:

  • Event-driven, robust to power and timing fluctuations
  • Decentralised TsetlinAutomata (TAs) for learning on demand
  • Mixed digital-analogcompute where elements are enabled and controlled by individual TAs
  • Natural approximation in its nature, both in learning and compute
  • Asynchronous logic for h/w implementation

The full set of my slides is here: https://www.staff.ncl.ac.uk/alex.yakovlev/home.formal/talks/AlexYakovlev-AI%20Hardware-070219.version3.pdf

My Talk at the RAEng Fellows Day at Newcastle

I was invited to give a talk on my Research at the Royal Academy of Engineering event, held in Newcastle on the 28th January 2019.

The title of the talk is “Asynchronous Design Research or Building Little Clockless Universes

The PDF of the slides of my talk are here: http://async.org.uk/presentations/AlexYakovlev-Research-RAEngEvent-280119.pdf

I only had 15 minutes give to me. Not a lot to talk about the 40 years of research life. So, at some point in preparing for this talk, I decided that I’ll try to explain what the research in microelectronic systems design is about, and in particular how my research in asynchronous design helps it.

Basically, I tried to emphasize on the role of ‘time control’ in designing ‘little universes’, where the time span covered by our knowledge of what’s is going on in those systems and why is between 1 few picoseconds (transistor switching event) and hours if not days (applications life times). So we cover around 10^18 events. How does it compare to the life of universe – being “only” around 10^13 years. Are we as powerful as gods in creating our ‘little universes’.

So, in my research I want to better control TIME at the smallest possible scale, surprisingly but, by going CLOCK-LESS! Clocking creates an illusory notion of determinacy in tracking events and their causal-relationship. Actually, it obscures such information. Instead by doing your circuit design in a disciplined way, such as speed-independent circuit design, you can control timing of events down to the best levels of granularity. In my research I achieved that level of granularity for TIME. It took me some 40 years!

But, furthermore, more recently, say in the last 10 years, I have managed to learn pretty well how to manage power and energy also to that smallest possible level, and actually make sure that energy consumption is known to the level of events controlled in a causal way. Energy/power-modulated computing, and its particular form of power-proportional computing, is the way for that. We can really keep track of where energy goes down to the level of a few femto-Joules. Indeed if a parasitic capacitance of an inverter output in modern CMOS technology is around 10fF and we switch it at Vdd=1V, we are talking about minimum energy quantity of CV^2=10fJ= 10^-14J per charging/discharging cycle (0-1-0 in terms of logic levels). Mobile phones run applications that can consume energy at the level of 10^4J. Again, like with time we seem to be pretty well informed about what’s going on in terms of energy covering 10^18 events! Probably, I’ll just need another 5 or so years to conquer determinacy in energy and power terms – our work on Real-Power Computing is in this direction.

Now, what’s next, you might ask? what other granularification, distribution and decentralization can we conquer in terms of building little universes!? The immediate guess that comes to my mind is the distribution (in time and energy directions) of functionality, and to be more precise intelligence. Can we create the granules of intelligence at the smallest possible scale, and cover same orders of magnitude. It is a hard task. Certainly, for CMOS technology it would be really difficult to imagine that we can force something like a small collection of transistors dynamically learn and optimize its functionality. But there are ways of going pretty close to that. One of them seems to be the direction of learning automata. Read about Tsetlin automata, for example (https://en.wikipedia.org/wiki/Tsetlin_machine) , in the recent work of Ole-Christoffer Granmo.

 

 

 

 

My paper “Energy current and computing” is online

Theme issue of the Royal Society Philosophical Transactions A

Celebrating 125 years of Oliver Heaviside’s ‘Electromagnetic Theory’ compiled and edited by Christopher Donaghy-Spargo and Alex Yakovlev is now online:

http://rsta.royalsocietypublishing.org/content/376/2134

My paper “Energy current and computing” is here:

http://rsta.royalsocietypublishing.org/content/376/2134/20170449

 

Power-staggered computing

In the past people were trying to develop efficient algorithms for solving complex problems. The efficiency criteria would often be limited to performance, CPU time, or memory size. Today, CPU time or memory is not a problem. What is a problem is to fit your computational solution within bounds of energy resources and yet deliver suffcient quality.

This angle of attack started to rise on the horizon of computing about a decade or so ago when people began to put many CPU/GPU/FPGA and memory cores on a die.

Terms such as power/energy-proportional computing and energy-modulated (my term!) computing began to emerge to address this approach.

What we should look now more at is how to develop algorithms and architectures to compute that are not simply energy-efficient or speedy but that are aware of the information they process, the level and granularity of its importance or significance, as well as aware of the implementation technology underlying the compute architectures.

This is underpinned by the concept of approximate computing and it’s not in the sense of approximating the processed data – say by truncating the data words, but rather approximating the functions that process this data.

For example, instead of (or in addition to) trying to tweak an exact algorithm that works at O(n^3) to work at O(n^2*log2), we can find an approximate, i.e. inexact, algorithm that works at O(n), which could work hand-in-hand with the exact one, but … Those algorithms would be expected to play different roles. The one which is inexact would act as an assistant to the exact one. It would work as a whistle-blower to the latter one. It would give some classification results on the date, at a very low power cost, and then only wake up the exact one when necessary, i.e. when the significance of the processing should go up.

One can think about such power (and performance too!) staggered approach in various contexts.

One such example is shown in the work of our PhD student Dave Burke, who developed a significance-driven image processing method. He detects the significance gradient based on stats measures, such as std deviation (cf. inexact compute algorithm), and makes decision on whether and where to apply more exact computation.

Watch this great video from Dave: https://www.youtube.com/watch?time_continue=1&v=kbKhU7CvEb8   and observe the effects of power-staggered computing!

 

Asynchronous drive from Analog

Run smarter – Live longer!

Breathe smarter – Live longer!

Tick smarter – Live longer!

I could continue listing these slogans for designing better electronics for the era of trillions of devices and peta, exa and zetta bits of information produced on our small planet.

Ultimately it is about how good we are in TIMING our ingestion and processing of information. TIMING has been and will always be a key design factor which will determine other factors such as performance, accuracy, energy efficiency of the system and even productivity of design processes.

As computing spreads into periphery, i.e. it goes into ordinary objects and fills the forms of these objects like water fills the shape of the cup, it would be only natural to think that computing at the peri or edge should be more determined by the nature of the environment rather than rules of computer design dominated the by-going era of compute-centrism. Computing for ages has been quite selfish and tyranic. Its agenda has been set by scaling the size of semiconductor devices and growing complexity of digital part. This scaling process had two important features. One was increasing speed, power consumption which has led to an ongoing growth in data server capacity. The other feature was the only way to manage complexity of the digital circuitry was to use clock in design to avoid potential racing conditions in circuits. As computing reaches the peri it does not need to become as complex and clocky as those compute-centric digital mosters. Computing has to be much more environment friendly. It has to be amenable to the conditions and needs of the environment – otherwise it simply won’t survive!

But the TIMING factor will remain! What will then drive this factor? It won’t certainly only be the scaling of devices and drive for higher throughput by means of clock – why? for example, because we will not be able to provide enough power for that high throughput – there isn’t enough lithium on the planet to make so many batteries. Nor we have enough engineers or technicians to maintain replacing those batteries. But on other hand we don’t need clock to run the digital parts of those peri devices because they will not be that complex. So, where will TIMING come from? One of natural ways of timing these devices is to extract TIMING directly from the environment, and to be precise from the ENERGY flows in the environment.

We have always used a power supply wire in our electronic circuits. Yes, but we have always used it as an always-ON servant, who had to be there to give us 5 Volts or 3 Volts, or more recently 1 Volt or even less (the so-called sub-threshold operation) like 0.4 Volts. That wire or signal has never been much of a signal carrying information value. Why? Well because such information value was always in other signals which would give us either data bits or clock ticks. Today is time to reconsider this traditional thinking and widen our horizon by looking at the power supply signal as a useful information source. Asynchronous or self-timed circuits are fundamentally much more cognizant of the energy flow. Such circuits naturally tune their tick boxes to the power levels and run/breath/tick smarter!

At Newcastle we have been placing asynchronous circuits at the edge with the environment into analog electronics. In particular, it has been power regulation circuits, A-to-D converters and various sensors (voltage, capacitance, …). This way allows significantly reduce the latencies and response times to important events in the analog, reduce sizes of passives (caps and inductors), but perhaps most importantly, thanks to our asynchronous design tools under Workcraft (http://workcraft.org) we have made asynchronous design much more productive. Industrial engineers in the analog domain are falling in love with our tools.

More information can be found here:

http://async.org.uk

https://www.ncl.ac.uk/engineering/research/eee/microsystems/

 

On the Role of Mathematics for humanity in building physical reality

Mathematics is a (or, probably, the only!) language that enables ideas about physics be communicated between people across different generations and across different cultures.

Inevitably, it ”suffers” from approximation and abstraction compared to physical reality. A bit like an impressionist painting reflects the real picture.

The question is what and how much is sacrificed here.

One test of whether the sacrifice is acceptable or not is in the way how people, while using mathematics, can build physical objects such as airplanes, cars, bridges, radios, computers etc. If they can and at a reasonable cost, then the language is adequate to the purpose.

For example, it seems that the mathematical language of Heaviside’s operational calculus is sufficient for the purposes of designing and analysing electrical circuits of good quality and in an acceptable time.

Another example, the language of Boolean algebra is sufficient to design logic circuits if we clock them safely so that they don’t produce any hazards. If, however we don’t clock them safely, we need other ways to describe causal relationships between events, such as Signal Transition Graphs.

 

 

My PhD Thesis (1982) – scanned copy in pdf

I have finally managed to scan my PhD thesis “Design and Implementation of Asynchronous Communication Protocols in Systems Interfaces” in Russian (“Проектирование и реализация протоколов асинхронного обмена информацией в межмодульном интерфейсе”)

The thesis is spread between several files (total – 255 pages):

Title, Contents and Introduction:

Chapter 1 (General characterization of the methods of formal synthesis and analysis of communication protocols): 

Chapter 2 (Formalization of the behaviour of interacting objects and communication protocols):

Chapter 3 (Interpretation of asynchronous processes and use of interpreted models for the description and analysis of protocols):

Chapter 4 (Organization of aperiodic interface of intermodular communication):

Conclusion and References:

Appendinces (1-5):

(1) Example of context procedure

(2) Example of controlled protocol

(3) Application of Petri nets to specification of asynchronous discrete structures

(4) Information transfer on three-state lines

(5) Analysis and implementation of the TRIMOSBUS interface

Exploitation confirmation letter from Ufa plant