Monthly Archives: May 2012

General Uncategorized

Vocabulary...

When trying to explain ideas and concepts to people, one of the biggest barriers can sometimes be the specialist vocabulary that comes with the subject area.  The wall of unintelligible words that can greet the newcomer can cause unnecessary distress; sometimes be off putting and cause you to be stumped.

065:365 - Stumped...

This doesn't always have to be limited to just technical phrases though, one of my colleagues is a keen cyclist and also a fellow yellow belly from Lincolnshire and recently I jokingly asked him for a 'croggy' much to the horror of my colleagues from the wrong side of the Pennines who probably thought I was propositioning him...  Folk from the West side of the UK call a 'croggy' a 'backy' which is essentially giving someone a lift on the back of your bicycle... I'm sure there are far more regional variations out there too that I've not heard of before... but this made me start thinking about technical phrases that may not be universal, even within engineering.

Part of the art of researching a new area is to ensure that you're familiar with this subject specific vocabulary; but at the same time the art in writing and communicating in an area; is to not hide behind the buzzwords and phrases that are associated with the area.  Indeed, those that are in command of their subject can frequently define and describe very complex areas and concepts using nothing but plain English... When it's done well, it's truly and art form to behold, but when it's done badly it can actually be to the detriment of the presenter (or author) and can make them sound unknowledgeable.

Hopefully I can bring the same level of explanations and analogical thinking into my academic writing (specifically my PhD thesis) that I try to integrate into my lectures.  I'm planning on having a productive summer and start to create some well crafted prose to describe the analysis that I'll be undertaking.  Only time will tell, but that's one of the reasons for keeping a blog going whilst I'm studying my PhD:   I'm hoping I can use it to kickstart my writing on those days when my brain refuses to start up properly.

Research

Sticky backed plastic...

One of the fun parts of my job is that I get to tinker about with software and see how it could be used, either for my research or for my teaching.  Over the summer, the MSc students will be undertaking their dissertations and most of the topics that I set are generally quite playful so as to maintain their interest and enthusiasm, but equally, they're highly demanding...  One of the topics that I'm interested in is the use of cardboard as a structural material and how this can be formed into innovative shapes and forms.  One of the initial difficulties can sometimes be encountered relates the geometry and the formation of organic forms.  This is where 3D modelling can come in handy, and I've slowly been trying to learn 3D Studio Max to help generate the geometry so I can unpick the structure to create templates.  Whilst these models can help me understand the geometry and overall shape and massing of models, it can be a large leap into constructing them and physically realising the componentry to create scaled physical models.  This is where my latest toy comes into play, it's created by AutoDesk and it's called 123DMake and it's attractively priced at £0 and is available for PCs and Macs and can convert 3D model files into cardboard planes that can be fitted together to make all sorts of intricate shapes...

I've only just started messing with the software, but I'm quite optimistic that I will be able to create some really creative forms and shapes with the software over the summer, I just need to get some cardboard and a nice sharp knife lined up, or sweet talk someone into lending me their laser cutter.  I know that it doesn't sound likely that cardboard can be used as a structural material, but it's being used successfully to make crash helmets that pass a multitude of safety tests and even more impressive is that cardboard is being used to create a temporary cathedral in New Zealand following the recent earthquakes...  Cardboard structures are not as uncommon as you might think, Frei Otto for example constructed the Japan Pavilion for the Hanover Expo... go have a rummage in your recycling bin, you might just have enough for a bungalow... at least 123DMake will give you a nice template to cut out and stick together for your next housing project...

Teaching Tutorial

Mathematica...

One of the reasons that I started this blog was so that I could mess about with embedding some Mathematica files to help with testing out some ideas.  For this to make sense it's easiest if I embed a few simple examples in this blog post.  Now if you want to interact with these examples, I'm afraid you're going to have to download the Wolfram CDF player, which is completely free and works on PC's and Mac's alike.  Imagine it as a sort of PDF viewer but it lets you interact with the files as opposed to a PDF which is typically just a static and lifeless document.

Consider the following equation:

Sin\left( {2x} \right)

Most text books would draw the graph for this over whichever range they deemed to be suitable and then students would try and learn from these dull and boring diagrams.

 Now this is how I was taught maths and in fairness, it's pretty dull and it's difficult to gain any form of intuition as to how it might behave if the 2 became a 3 for example, this is where Mathematica's CDF files come in handy because it has some nice tricks for letting you explore maths in an interactive fashion... let's consider the following equation, from the previous graph most people wouldn't really know how it would affect the graph.

Sin\left( {a.{\rm{ }}x} \right)

But if we crank this through Mathematica we can create a really nice interactive widget that can be shared with anyone for free!  As you change the slider, the graph updates in real time, and if you want to know what number you're changing 'a' to be then simply click the little + sign next to the slider itself to expand the input values beneath it.  In fact if you think that messsing with sliders is far too much like hard work, then simply click the little play button in the top right and the widget will work the sliders for you... sit back and watch the pattern.

 

If you're not familiar with Mathematica, you may be concerned that this sort of widget is really difficult to create, but actually I'm still on Chapter 3 on the text that I'm working through and the code is incredibly simple to create this kind of interactive learning tool and I've replicated it below to show how few lines of text can create this level of interaction.

Manipulate[ Plot[ Sin[a x], {x, -10, 10}], {a, 1, 5}]

Essentially this code starts with "I want a slider widget", "Plot me a graph of Sin(a.x) over a range of values for x from -10 to 10", then "make the slider vary a from 1 to 5".

Now this seems ok, but the Manipulate command is actually incredibly powerful and with a little more twiddling, high quality interactive 3D plots can be created, so let's consider the following expression.

f{\rm{ }}Sin\left( x \right) + g{\rm{ }}Sin\left( y \right)

This expression has four variables: f,g,x, and y.  Of course, I bet you're dying to know what the graph looks like for this function so you can boost your maths skills...

 

This is where the CDF player starts to flex its muscles a little, not only can you mess around with the sliders to change the values of f and g... but you can click and rotate the 3D graph itself to get a better view of how you think it's working.  For me this level of interaction is a real opportunity for playing with the maths to help build up a level of intuition and feeling of how the maths will behave.  And once again the code to get it to work is fairly straight forward even for a novice such as myself.

Manipulate[Plot3D[(f ) Sin[ x] + (g)  Sin [y], {x, 1, 10}, {y, 1, 10}], {f, -10, 10}, {g, -10, 10}]

Now here's the rub, a full Mathematica licence is the best part of £1,000 for a lecturer to use, in these hard times that's a lot of money.  But because I carry 'dual' status as I'm studying 2 degrees as well as working full time as a lecturer I was able to pick up a student licence for roughly £80.  Normally the cost for a student licence is a shade over £100 but it is possible to reduce the normal student price by 15% by using the discount code PD1637 at the Wolfram store checkout and I still retain the full functionality of sharing my CDF files via export.

I hope this helps someone, if you've any feedback on this post or would like to ask any questions, please get in touch or leave a comment below.

General Tutorial

Equations...

Turns out that my web provider now provides a SQL and PHP server with my base package and this was all the incentive I needed to give a self hosted WordPress blog a whirl.  To get a basic blog system up and running literally took me 5 minutes with the free WordPress software and using the export function I was quickly able to copy the few posts over from my free WordPress blog.

Now I have my own hosted service this presents me with several advantages over the free wordpress accounts, but there are two in particular that are attractive to me.  The first one is that I can now embed proper equations into a blog post using LaTeX and MathML by linking it into my equation editor MathType...

By adding in the 'LaTeX for WordPress' plug in for the hosted WordPress, I can now copy equations straight from MathType and paste them directly into my blog by following this procedure.

1.) Open MathType and prepare your equation.

2.) Go to MathType -> Preferences -> Cut and copy preferences; and then select MathML or TeX; then LaTeX 2.09 and later

Click

3.) Highlight the equation in MathType 6.7d and then right click and select copy or press (⌘ + C)

4.) Find the position in your blog post where you want the equation to appear, then paste (⌘ + V)

Following this means that I can embed equations like the one below pretty easily, the only downside that I've found is that if you've colour coded your equation in MathType, none of this formatting will carry over when pasting, but the equations should work and be visible in any browser, certainly the main three and on the iPhones and Android devices that I've worked on so far.

{F_d} = \overbrace {\sum\limits_{j \ge 1} {{\gamma _{G,j}}{\rm{ }}{G_{k,j}}} }^{{\rm{Permanent}}} + \overbrace {{\gamma _p}{\rm{ }}P}^{{\rm{Prestress}}} + \overbrace {{\gamma _{Q,{\rm{ }}1}}{\rm{ }}{Q_{k,{\rm{ }}1}}}^{{\rm{Leading}}{\rm{ Variable}}} + \overbrace {\sum\limits_{i > 1} {{\gamma _{Q,{\rm{ }}i}}{\rm{ }}{\psi _{0,{\rm{ }}i}}{\rm{ }}{Q_{k,{\rm{ }}i}}} }^{{\rm{Other Variable Actions}}}

With minimal tweaking and a little trial and error with the LaTeX code I was able to apply some colour tags to get the equation to look the same as it does in my lecture notes.

{F_d} = \overbrace {\sum\limits_{j \ge 1} {{\gamma _{G,j}}{\rm{ }}{G_{k,j}}} }^{{\rm{\color{Red} {Permanent}}}} + \overbrace {{\gamma _p}{\rm{ }}P}^{{\rm{\color{Red}{Prestress}}}} + \overbrace {{\gamma _{Q,{\rm{ }}1}}{\rm{ }}{Q_{k,{\rm{ }}1}}}^{{\rm{\color{Red}{Leading}{\rm{\color{Red}{ Variable}}}}}} + \overbrace {\sum\limits_{i > 1} {{\gamma _{Q,{\rm{ }}i}}{\rm{ }}{\psi _{0,{\rm{ }}i}}{\rm{ }}{Q_{k,{\rm{ }}i}}} }^{{\rm{\color{Red}{Other Variable Actions}}}}

This might initially appear to be quite a minor thing, but I've found that colour coding my notes like this really helps the students follow the equations when I'm talking them through various parts of the equations and so I was keen to keep the high quality formatting on my blog.  One thing that I have noticed however though is that the equations appear much much sharper on mobile devices and Apple machines, whereas on windows machines they appear slightly pixelated.

As to the second advantage this is that I can now embed Wolfram Mathematica CDF files into my blog directly, which will help me share some of my examples with anyone interested in my research.  I'll write another blog post on this over the next few days...

General

Growing pains?

I've toyed with the idea of installing WordPress onto my own webspace for several years, but the barrier has always been the same: I don't have a SQL database on my domain. Today I logged into to manage my account and I've discovered that my provider has now added SQL databases in as standard for my package which is great news.

The time for this couldn't be better either, as I've been tinkering with some Mathematica scripts lately and I can now embed them within blog posts etc, except that for this to work I need to have a way of getting iFrame tags to work... which can't be done on the free version of WordPress.

If I was to upgrade though, then this could be embedded quite easily, indeed Mathematica can publish specifically into WordPress if needed.  If I can get me head around this, then I'm likely to delete this blog and recreate elsewhere as part of sharing my research.  It'll be really interesting to see how it comes together, although in fairness I shouldn't get too excited as I've a habit of tinkering which usually means I'll tinker and then break my hosted blog somehow!