Category Archives: technology

new technologies, latest trends

Haptics: First impressions of the Novint Falcon

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Haptic feedback has been in the process of coming of age for a good long time. Logitech released the force-feedback iFeel mouse (I swear I am not making this up) about a decade ago (see review, slightly more cynical review).  It got a few headlines at the time, but eventually somebody pointed out that it was essentially a mouse that went ‘buzz’, so that was that. On the other side of the scale, the CS dept at the University of Bristol once kindly permitted me to be a victim experimental subject for a very interesting piece of work that made use of midrange SensABLE Phantom devices, which you can see here. Be advised in advance that if you have to ask the price of a SensABLE device, you probably can’t afford it.

One of the problems with haptics is that it’s simply pretty hard to explain. The Phantom experiment, for example, was very cool; the brief was to ‘feel’ your way around a three-dimensional workspace, and try to describe the object you can feel. Umm… it’s sort of boxy. There’s a sort of doodad here. Um, there’s a gap in the middle. What is it? Oh. Wait. There’s another doodad below the first one. What on earth is it? And in the end it would turn out to be a model of a desk, at which point you, the lab rat experimental subject, would say, “Oh, right.”

So on the one hand, people aren’t very good at identifying objects by touch. (For a more complete discussion of our confused mumblings, see Pearson & Fraser, 2008. Read it. It’s interesting…) On the other hand, as confusing as the information may be to use, the experience of fumble-fingering your way around a 3-D model of a piece of office furniture is extremely good fun.

Of course, that meant that someone was going to build this stuff into a game, and yeah, it’s been done. From the invention of haptic battle pong, which on the face of it must be one of the most amusing things you could possibly do with the most reasonably priced SensABLE device (recently on sale at 800 euros), things have moved on. But the one that caught our attention was the Novint Falcon, which first shipped in 2007 and, at $180 plus inevitable overhead in customs charges and the like, is only a fairly expensive method of playing Pong in the workplace.

So we bought one. It looks a lot bigger in real life. And after we got it installed, and got over playing the games that came with the device – particularly one in which the player is invited to launch ducks into a series of ponds using a large catapult – we settled down to see what else we could do with it and the available frameworks, such as Chai3D.

Here are Andy Hewson’s first impressions of the Falcon and the Chai3D demos:

Pearson, W. and Fraser, M., Collaborative Identification of Haptic-Only Objects, in Proc. EuroHaptics 2008, Madrid, Spain, June 2008, pp. 806-819.

Accessing local-network-only web pages from outside the firewall

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VPNs aren’t as painless as they ought to be, and setting one up purely in order to get at web pages that have been hidden behind a firewall can seem to be overkill sometimes. But then, there are good reasons for hiding things like internal finance-and-admin web pages behind a firewall. What to do?

OpenSSH to the rescue! Greg Tourte just pointed out an alternative to using the VPN in order to access these internal web pages, such as Agresso. It certainly works on Linux and on the Mac, and should also work using Putty (see http://home.fnal.gov/~dwd/ssh-to-browse-behind-firewall.html). This is pretty useful. For example, people within UKOLN who might be having difficulty accessing internal web pages such as Agresso due to VPN problems should be able to use this method instead.

It relies on the fact that OpenSSH has a lot of little-known functionality, in this case, the ability to act as a SOCKS proxy (see http://en.wikipedia.org/wiki/SOCKS for lengthy and boring introduction). In short, OpenSSH can tunnel through to a machine at UKOLN and then allow the browser to treat that connection as a standard web proxy. Because the web proxy endpoint is inside the Bath network, it permits access to internal web pages.

Here is a blog post describing the basics of this openssh functionality:
http://alien.slackbook.org/blog/securely-browsing-the-net-using-socks/

Here are the steps required to set up a SOCKS proxy in order to access these internal web pages remotely (we just tested this on a Mac and on Linux).

1. Install Foxyproxy on Firefox : https://addons.mozilla.org/en-US/firefox/addon/2464

2. Open a terminal window and type: ssh -D 8888 yourusername@InternalServer.YourUniversity.ac.uk
Type in your password when prompted to do so. You will then get a ssh session on InternalServer; just leave this open.

3. Open FoxyProxy, and complete the following steps:

a) add a new manually configured proxy, with the host/IP ‘localhost’, port 8888, click ‘SOCKS proxy?’ and set it to SOCKS v5.

b) Add a new pattern defining when this proxy should be used:
Given the example of setting this up for Bath’s Agresso server:
Call the pattern something like ‘Agresso’, and put in the URL: *agresso.bath.ac.uk/*
Under ‘URL Inclusion/Exclusion’, select ‘Whitelist’, and under ‘Pattern Contains’, select ‘Wildcards’
Make sure that the newly set up proxy is enabled.

 

4. Type http://agresso.bath.ac.uk/ into the address bar. Hopefully, FoxyProxy should make use of the pattern that we have just set up and send the traffic through via the SOCKS proxy.

Caveats: Obviously, just as you need to turn on the VPN before you can access Agresso via the VPN, you will also need to run the SSH step before you can access Agresso via SSH – the SOCKS proxy only lasts for as long as the SSH session remains connected. That said, you can simplify the setup process by adding it to your ~/.ssh/config file, for example:

Host agresso
HostName InternalServer.YourUniversity.ac.uk
DynamicForward 8888
User MyUsername

If I then type ‘ssh agresso’, and type in my password, that does the trick.

This simply goes one step closer to proving that no matter what the problem, if it involves a network, SSH has an answer.

Value Add

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Probably the most important thing I discovered in this project was the importance of ‘crowdsourced’ data in filling in the gaps between metadata and common knowledge.

The availability of Wikipedia as a source of random information, although much of it contains inadequate structure to search through with something like dbpedia, is a very important factor for us in improving the metadata and the data that we are putting together to support usage of that metadata. It’s not perfect of course – or perhaps it’s better to say that the imperfect and rough ways in which we use the data are not able to achieve the sorts of results that one might like – but it seems obvious that it’s an invaluable resource for the future.

Other data sources have been invaluable for us as well, particularly DBLP, despite the strong focus on computer science (which, however, means that for training across domains we should probably be looking elsewhere too 🙂 )

Finally, social tags have been less effective for our purposes than one might imagine for one reason, which is that there aren’t an awful lot of them around, and those that are need to be detected by a relatively complex process of resolving title/author into the most popular mirror URI(s).

We’ll be publishing some of the extracted data shortly – boring but useful stuff like lists of institutions, urls, coordinates, enhanced metadata, etc – so hopefully it will come in useful to others!

Technical standards

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In our project (Writeslike.us) we are using a number of different techniques and tools to make things done.

Coding

As main development languages scripting languages Perl and Python were selected. Python is good for text parsing because language features and external library – Natural language toolkit (NLTK.org) which allow to stem and tag text. The text parsing is non-trivial tasks so for that purpose NLTK use heuristic approach and also offer a training data set for parser to be trained. Perl is native choice for development under Linux and it has powerful set of libraries in CPAN system. In particular XML parsing and full text document crawling functions were written in Perl.
As development tools we are using Eclipse IDE with Perl and Pydev for Perl and Python respectively. In some cases VIM featured text editor is in use. Using such heterogeneous tools implies that project file structure should be flat and simple.

Infrastructure

For running and hosting we are using such proven tools as MySQL and Apache. Subversion (SVN) is used to store and keep track of software versions.

Architecture

The calculation we need to perform to build authors relations network is too resource-intensive to be performed on demand, therefore we need to generated and store database tables with pre-calculated data as some sort of caching approach. Since our project is re-using existing metadata (in Dublin Core (oai-dc, often from qualified DC)) from a repository we were required to add to original project feature list also XML parser and document full text crawler functions.
In order increase usability of the project offered functionality we created a REST interface which enable machine2machine interface. The interface enabled in both directions, i.e. for adding new information about person or publication and for making query to find peers.
Further development plans adding automatic metadata extraction servers to improve quantity and quality of data or to extract further information (FixRep, paperBase).


What programming languages we use and why we love it/them  -technologies, standards, frameworks that make our lives easier (or harder).

In actual fact there are rather a lot of these! In the case of writeslike.us we have stuck to scripting languages, in particular to Perl and Python. Each of these have their benefits and their issues. Arguments centre around Python’s semantic whitespace versus Perl’s line-noise pseudo-ppp transmission ‘write-once, read never’ look, for example. However, both come with a great variety of extensions and libraries. The ‘killer app’ for Python was NLTK, and once one is used to Perl’s CPAN, it becomes indispensable for certain tasks. In the end, arguing about which language is better is pointless, even though it is great fun. The Computer Science department presently teaches Python, and as such Python is the language with which most CS students are more familiar, whilst EE students seem to be either Perl or Matlab according to recent evidence.

In the end, the important point is that prototypes are developed quickly and easily, and that the techniques and datasets underlying them are well understood. If this is the case, then the rest can usually be adapted to suit – rapid development is not the same thing as throwaway prototyping, but rationalisation of software platforms and standards can very well be part of evolutionary prototype enhancement.

Day-to-day work

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1.scrum meeting + meeting minutes

  1. see the progress made by what people present – what they did yesterday, what they expect to do today, and what worked for them. Allow the manager to keep track of how the project development is progressing and how the team are performing.
  2. find and solve potential problems before they become significant or expensive!

2. collaboration on code

  1. Allows developers to learn from each others’ expertise; permits peer-review of code (extreme programming-style?) and review of functionality.
  2. A long-term goal for this approach is to encourage developers to share code, to think of it as ‘our code’ rather than ‘my code’ and to be more open to review, reuse, constructive criticism, etc.

3. moving code between machines & testing code on different workstations

  1. A single functional installation does not mean that a development project is finished, since it may be very difficult to set up on other platforms, to understand or to reuse.
  2. It should be functionally portable and include all necessary libraries, scripts, datasets and configuration to promote remote development, reuse and external contribution to the codebase.
  3. This also encourages review and testing since it tends to highlight any difficulties with installation and use of newly developed components.

Active collaboration and a flexible approach to development in particular tend to optimise productivity, in that time spent coding also has a knowledge sharing component – and there is relatively little time spent becoming familiar with code before beginning to contribute.