Sunday, October 2, 2016

Thinking in Systems, Donella H. Meadows, Chelsea Green Publishing. (2008)

Donella H. "Dana" Meadows died in 2001, the draft of this book was completed in 1993.  The draft was edited and published by Diana Wright in 2008.  This book contains a distillation of the work initiated at MIT by Jay Forrester and the MIT System Dynamics group.  Systems thinking is applicable in many areas.  This may well be the best introduction.

Saturday, October 1, 2016

The Limits to Growth, Donella H. Meadows, Dennis L. Meadows, Jorgen Randers, William W. Behrens III, Universe Books. (1972)

This book reported on a computer project and reported on the predicament of mankind, it was a report for the Club of Rome.  For many this was the first book of its kind and it was for many, the point where they realized that there were limits to growth.

The idea was not new, I was introduced to the idea by my history teacher Charles B. Fielding.  Mr. Fielding was not famous, nor a well known academic.  As I recall, Mr. Fielding was from Barrow-in-Furness, he was a teacher at several schools in Swansea, Wales.  He was, simply, the best teacher that I have ever known - and he deserves much of the credit for my skills as writer and an analytical thinker.  It is of interest, and says much for the value of a liberal arts education, that the two most influential people in my education were historians.  Charles Fielding was one, the other was the renowned Swansea historian Norman Lewis Thomas, who was at school with my father.  They of course didn't contribute to the development of my mathematical skills, but that is a story for another time.  Mr. Fielding inspired me to read Thomas Malthus; An Essay on the Principles of Population (2nd Edition, 1803) by Malthus is the true source of all work on the limits to growth.

Later work that predates the Club of Rome efforts is that of M. King Hubbert, Hubbert focuses on resources - the Limits to Growth would have been better if it had been informed by some of Hubbert's ideas.

Since this work has been updated many times, I will note that this is a book that everyone who is interested in growth and the limits to growth should read.  It is easy to read because it has been made available on the web.  The original can be legally downloaded from the Donella Meadows Institute.   Since the original work has been greatly modified and updated since it was published, I will save a detailed review for a later version.  At this point, I will say that if you are not familiar with Meadows, you should download this now.  Resource limitations, conservation, and climate change should not be political issues, they are critical to the future that we are creating for our children and grandchildren.

The Art of Modeling Dynamic Systems, Foster Morrison, Dover Reprint of a John Wiley book (1991, 2008)

Long ago, before Amazon.com there was a scientific book club modeled after the venerable Book of the Month Club - which I was surprised to find still exists.  The model was the same, you got four books for a dollar, and then you got a monthly magazine with reviews of other books, and you had to buy four more books at the regular price within a year or two to fulfill your membership agreement.  A selection was scheduled each month, which you got if you didn't remember to send in your postcard saying you didn't want the selection.  There were similar club for long-playing records, 8-tracks, cassettes, CDs and DVDs, most (I actually thought all) are extinct by now.

I'm pretty sure that I got my original copy of this book because I didn't return the reply card, but its possible that I ordered it.  Either way, it is one of the best purchases that I ever made, and I would never have found it without the club, which I think was called the Library of Science, and astoundingly it still exists, I just checked, hence the link.  I guess that many of the old clubs have go online.  Anyway, in 1991 the World-Wide Web didn't exist, I had just got an e-mail account, and things like Gopher were just being developed.  Information was hard to find, and you learned about new books if they were reviewed and when they appeared in reference lists.

Morrison's book, which has the subtitle Forecasting for Chaos, Randomness, and Determinism, was an eye opener.  This is where I learned about modeling and forecasting and that it was possible to study dynamic systems without calculus (I admit it was many years before I realized that there were advantages to this approach.)  The Dover book has a couple of extra diagrams from Morrison's  papers at Federal Forecasters Conferences, and and some added references, but it largely unchanged.  So if you want to learn the basics of modeling and forecasting, this is a good place to start.  The book still doesn't make more than a passing reference the System Dynamics work in Jay Forrester's group at MIT, or the related work of Donella Meadows.  Both groups would have benefited from collaborations, if the system dynamics people had talked to the forecasters, the system dynamics groups would not have neglected to use resources in their models!  I will revisit some of the other work in this area over the next few months.

Modeling the Environment, 2nd Ed., Andrew Ford, Island Press. (2010)

When I'm not working on physics or an administrative task, but am still working, I am most likely to be doing something in the area of forecasting, modeling and data science.  Most of the modeling that I have done has been using Fortran, Python, or Matlab.  I am aware that many others do modeling, environmental scientists, economists, sociologists, and others.  So my question has always been:  How can you do dynamics systems modeling if you have little or no experience with calculus and differential equations.  Well, the answer, in part, can be found in this book.  You can use software that does all the higher level mathematics behind the scenes, and as a modeler, you can focus on stocks, flows, feedback, and timescales.

The book is clear and detailed, and it soon becomes clear that modeling of this kind has its place.  I am going to add the methods to the methods that I regularly use.  As well as describing the modeling process, the book serves as an introduction to two widely used computer tools, Stella and Vensim.  I have been using Vensim as you can download Vensim PLE (Personal Learners Edition) for evaluation or educational purposes at no cost.  The book has more examples in Stella, but translating between the two is relatively straightforward.  I recommend that your familiarize with these modern modeling tools.

Thursday, September 29, 2016

Signals and Systems: A Fresh Look, Chi-Tsong Chen, 2009

This is a self-published book, you can buy a paperback from Amazon, or you can find a freely distributable copy on the internet.  Buy a copy, if you are interested, it's worth it.  There are at least 30 widely used books out there on this topic.  This one focuses on what you actually need to know.  It is well written and classroom tested.

From the preface:


Feedback from graduates that what they learned in university is not used in industry prompted me to ponder what to teach in signals and systems. Typical courses on signals and systems are intended for sophomores and juniors, and aim to provide the necessary background in signals and systems for follow-up courses in control, communication, microelectronic circuits, filter design, and digital signal procession. A survey of texts reveals that the important topics needed in these follow-up courses are as follows:
  • Signals: Frequency spectra, which are used for discussing bandwidth, selecting sampling and carrier frequencies, and specifying systems, especially, filters to be designed.
  • Systems: Rational transfer functions, which are used in circuit analysis and in design of filters and control systems. In filter design, we find transfer functions whose frequency responses meet specifications based on the frequency spectra of signals to be processed.
  • Implementation: State-space (ss) equations, which are most convenient for computer computation, real-time processing, and op-amp circuit or specialized hardware implementation.
    These topics will be the focus of this text. 
Dr. Chen's other books are also excellent.

Differential Equations in 24 Hours, Scott Imhoff, Outskirts Press, 2016

This is in some ways a new edition of Imhoff's Shortcut to Differential Equations.  The book presents the basic methods used to solve ordinary differential equations.  The title is not meant to be taken literally, the book is divided into 24 lectures which could be delivered - hence 24 hours.  The book contains many examples, and it includes the answers to the exercises.  The author focuses on methods that you will actually use - he doesn't include all the typical methods found in today bloated text books - this is good as you would never encounter many of these methods again.  A few biographical sketches have been included - these add nothing to the book, but at a list price of $12.95, there is no reason to complain.  If you are highly motivated, or if you need a refresher this book is a good resource.  I have added it to my collection and I will use it to bring the undergraduate researchers up to speed quickly.

Partial differential equation are only mentioned.  When ever I encounter a new book on differential equations, I think of the retired University of Mississippi theoretical physicist Gordon Baird.  When I was a beginning graduate student, he said to me one day how surprised he was that courses in differential equations only covered ordinary differential equations in the course of a semester.  He went on to say that if they were to use something like Francis Hildebrand's Advanced Calculus for Engineers that you could cover ODEs and PDEs in one semester.  This book was later to become Advanced Calculus for Applications - though, I note that Amazon has a nice reprint of the original 1949 edition in paperback.  The situation hasn't improved in the 38 years since Gordon told me this - today's books are even more bloated than those of 1978.  So if you want to learn ODEs, Imhoff is a good start, then spend another $16.95 and over the course of 6 months you can become an expert solver of (linear) differential equations.

Hildebrand was an MIT Professor, the course at MIT still uses Hildebrand's book and is available on MIT open courseware.  The course is from 2004, but I think Hildebrand retired in 1984.  You can download a nice set of lecture notes.  I will pull out my copy of Advanced Calculus for Engineers and write an appreciation in the next few days.

Wednesday, May 25, 2016

Film Review: Most likely to succeed

Today I watched a movie called Most likely to Succeed at the national UTeach Conference.  The film looks at the history of education in the US, and points out the shortcomings of education in preparing students for the work force of today and tomorrow.  It investigates a model developed in San Diego called HIgh Tech High.  It shows what students can do using project-based learning.  You can't rent it or view it on Netflix.  It can only be seen at festivals and community viewings. 

If you get a chance to see it, you should.  While it might not seem to be an exciting topic, I watched it both times that it was presented.  I've requested permission to host a viewing in Conway - we'll see what happens.  I have long argued that computers will completely change education - this film shows how it can transform the high school experience.  The film has a website here.

Monday, April 11, 2016

Hope Jahren, Lab Girl, Alfred A. Knopf, New York, 2016

This book should be read by everyone involved in STEM education - it provides insight into the difficulties that are experienced by women in academia in STEM fields.  Actually, it has much of interest to anyone planning an academic career.  The book is very well written - Jahren has a blog called #HOPEJAHRENSURECANWRITE and Hope Jahren sure can write!  The book intersperses interesting short sections on trees, plants and paleobiology with Jahren's story of building labs at Georgia Tech, Johns Hopkins, and the University of Hawaii.  I'm not going to repeat what you can find in other reviews.  If you want a content review or to read an interview, you can find them at Kirkus Reviews, The New York Times, Elle, The Guardian, Time, Library Journal, and many other places from the Irish Times to Entertainment Weekly

The importance of books like this was underlined for me last weekend.  I was at a Louis Stokes Alliance conference, and an African American Scientist was reflecting about his career.  He related two incidents, in the first a young woman was passing his office, stopped, walked back and looked in and said "I never thought that I would see a professor that looked like you,"  the other incident was less savory, another student shared his opinion that someone who looked like the professor clearly didn't really deserve to be a professor.  We need books like Hope Jahren's because while we are now well into the twenty-first century, there are those amongst us who have not embraced the changes of the twentieth century, or, in some cases, the nineteenth.  I reiterate, everyone should read this book, buy an extra copy so that you can loan it to your friends.  If you are like me, you won't want to loan out your first copy as you will want to re-read it.