Luke Lanchester @ BCU

Week10: Computer Ethics

2007-11-29T14:46:00.000Z

I believe the list is flawed, for example, a police forensic examiner may need to snoop around in a persons’ files to identify any illegal materials that may exist. Likewise the 8th commandment does not allow exceptions if attribution is given (and allowed under the associated license). Mainly these are simple omissions for exceptional circumstances, but any legal equivalent of these commandments must make mention of them lest it be consigned to the rubbish bin for being overly vague and useless. Alternatively, any computer tied into a military application is ultimately breaking the very first commandment regardless of any others.

Intellectual property rights are mentioned in the list, but more effort must be made to differentiate between strict copyright laws, copyleft laws and those that lie in between. For example, number would not allow the Linux operating system as large sections are often licensed under the General Public License and as other people can appropriate licensed materials.

I think an eleventh commandment, or perhaps just a general rule of thumb, would be to think before you click. A humorous email may sound funny to your own ears but others may take offence and it can land you in trouble. Once you’ve hit the send button there is no way to un-send that email, so think beforehand.

Week9: Disability and Websites

2007-11-22T13:48:00.000Z

Under the Section 21 of the UK Disability Discrimination Act 1995, any UK business website must make reasonable adjustments to its site such that disabled visitors can still access their services. In 2003 the Sydney Olympics website was sued under a similar law for failing to provide reasonable access to disabled visitors with an eventual payout of $20,000. This highlights the seriousness to which these new laws can be taken.

If a blind visitor found a site they were unable to access they have several choices. Firstly they can contact the site itself, noting the failings they’ve found within the website and asking them to update it. Failing that they can contact one of several groups who try and fight on behalf of disabled web users, the RNIB is particularly voiceful against non-standards compliant websites. Finally they can contact a lawyer and prosecute the site for not providing reasonable access, however this can be costly for both parties.

Many companies would rather choose to pay for a new, W3C standards compliant website, than having to face the alternative; a lengthy court battle with mounting legal fees at the end. Nowadays there is no reason not to make an accessible site, with not only the legal but moral implications that follow it.

Week8: Three-Tier Internet Model

2007-11-22T13:37:00.000Z

A three-tier architecture, used in web application development, can provide numerous benefits. It has a high degree of flexibility, scalability and performance all of which can save a business from problems down the line as their website traffic grows. For example new machines can be added or operating systems changed without causing disruption to the other levels.

Problems however can be caused by the stateless nature of the system, particularly in sharing data between machines. You have to ensure that data shared between machines is up-to-date, usually by some form of locking mechanism. Systems designed to run on multi-tier systems must also be designed differently with an emphasis on limiting dependencies such that code can later be changed with the minimum number of changes necessary elsewhere.

Week7: Presentation Notes

2007-11-13T11:01:00.000Z

They say hindsight is 20/20, so here are some pointers on how to do your first A1W, or any other module, presentation just that bit better.

Rehearse. This should come as a no brainer but with each iteration over your presentation it becomes more fluent and natural, so when you finally stand up and perform it you should not constantly glance at your notes.
Do not write your presentation on screen. There's the temptation to write out all of the information you've found on screen and then just stand back and read it. What the hell is the point of you been there then? Each slide should contain a few key words or images with you providing the meat of the information. If necessary put your script in the notes section so that if someone wants to view the presentation later they can get your input alongside.
Be confident. For those few minutes you're the boss, you're in control. Speak clearly, making eye contact with each member of your audience. If you want to go off on a tangent (at least somewhat related to the topic at hand), do so. Just don't get sidetracked.
Tag team. If you're not going it alone make sure you've decided who's going to stand where, how you'll transition between speakers and how you can get out of the next persons way when they come to speak. It fits in with the rehearsal aspect, having a dry run in the chosen location (or similar setting) can save many a problem later on. And while you're awaiting your turn, or have already finished, don't shake your head, start chatting or otherwise draw attention to yourself. Stand back, watch the screen and await the end quietly.
Pause, compose, resume. It happens to every speaker, you get lost in your own words, floundering like a fish out of water. Take a step back, look at your notes, think what you're going to say next and say it. It may seem like an eternal pause in your mind but realise the audience is most likely still digesting what you've just said anyway. Flapping your arms about, shuffling through papers and making noises like a toddler is not going to impress your listeners, so just take a breath, ignore the pressure momentarily, and get back on track.
Question time. You can expect a grilling on your chosen topic, so there's no excuse not to read up. Find out recent happenings, important dates and other points which you may have omitted from your presentation but that could come in handy. A sheet full of dates, locations, people and names may seem overkill but can save your skin later on. Read up and test each other with example questions.

Hopefully the next people to stand before an audience can be forewarned and forearmed. Best of luck.

Week6: Apache

2007-11-05T15:22:00.000Z

Apache is the most popular choice for web servers on the Net with almost 50% of all machines running it. Released under its own license, the Apache HTTP Server software is released freely.

Uses

Apaches main usage is to handle incoming requests and pass them on to the relevant handle, this is typically a URI mapped to a file location. However it can also use various rewrite directives, typically mod_rewrite, to map a location to different locations to aid in the production of SEO amongst other things.

Apache can also handle a large array of dynamic scripting languages through the use of various libraries. Typically Apache can run PHP, Python, Perl and Ruby on Rails amongst others.

Finally, virtual hosting allows one installation of Apache to serve multiple websites which is used by shared hosting providers. With virtual hosting a single machine running Apache can provide the web serving capabilities for www.example.com, www.example2.co.uk and www.subdomian.example.com simultaneously.

Static & Dynamic

Web pages fall under two categories when served. A static page (normally HTML) is a file which contains plain text and does not change between requests. These pages are small and quickly served as no further action needs to be taken by the web server.

Dynamic pages are pretty much what they sound like, the content they display changes. This can be based on user input i.e. search terms, database content or even something as simple as time of day. Depending upon the complexity of the script the time needed to generate a dynamic page can range from a few milliseconds to several seconds (typically web servers have a timeout limit to prevent pages running for excessive amounts of time). Dynamic pages are intrinsically slower than static pages however through the use of caching this difference can be reduced.

Week5: The Importance of Research

2007-10-25T15:45:00.000+01:00

To be able to give a presentation about your given subject you must first understand it yourself. If at the end a question is asked to which you have no answer you have failed not only the attendees, but yourself. Submerging yourself within a subject should come naturally to anyone who enjoys said subject.

Following links to learn more and more about a subject is a great way to learn. Simply reading preset material will only give you a very limited view of information, potentially leaving vast holes in your understanding of key concepts.

Week4: Mobile Email

2007-10-22T20:40:00.000+01:00

The web is accessible from anywhere at anytime so it is only logical that access to email should follow this paradigm. The advantages are numerous, but for the sake of brevity here are the most relevant two.

Mobile email can be thought of in much the same light as mobile phone calls. It is one of those progressions that seems natural, ensuring that we are always able to communicate regardless of our current location and/or access to computer/internet. Been able to always check for new mail or send off a quick reminder (even to yourself) is great. Another advantage is the fact that email is often a cheaper and more useful form of text messaging. A SMS is limited to a small amount of characters where as an email can be as long as required. With many plans now offering unlimited data usage it often be a cheaper alternative to email a friend rather than text them.

The disadvantages are few and becoming increasingly rarer. The first and foremost in my opinion would be security. Using a wireless network connection is inherently dangerous as any passer-by can easily intercept data and view there contents. Another disadvantage is the cost. Internet access, be it through phone or café, can be expensive and may not offset the advantages of having such access.

Week3: Why IP Addresses Are Running Out

2007-10-11T13:11:00.001+01:00

The IP address is intrinsic to nearly every event on the Internet, from performing a Google search to playing an online multiplayer match in a videogame. They are the unique identifying addresses of each node upon the Net. However, due to the nature of the IPv4 Protocol the maximum number of IP addresses is 4,294,967,296 (256x256x256x256, or 2³²). This limitation is caused by the fact that the IPv4 address header can be a maximum of 32 bits long.

However, this ceiling is further limited by the assignment of large blocks of IPs to various uses. For example multicast has over 270 million address assigned to it along with another 18 million for private networks. Some allocated addresses are unused and as such take up value space from the public sector assignments.

There are two methods to overcome this. The first involves restricting and controlling the use of existing addresses i.e. allocating only what is necessary and avoiding waste. However most experts feel this is only a short-term solution as at the present rate we will run out of addresses in approximately 3 years.

The second solution is to switch to IPv6, the hopeful successor to v4. IPv6 supports addresses up to 128 bit long raising the ceiling to 3.4x10⁴⁸ addresses, or in more human terms each person on this planet could have a billion, billion, billion addresses of their own with room left over.

The rollout of IPv6 has so far been very slowly with large corporations reluctant to make the jump as it would be very costly. However it may eventually become a requirement as every fridge, phone and arm (Kevin Warwick) gets their own address.

Week2: Search Me The Web

2007-10-04T13:17:00.000+01:00

Yahoo has been around for a long time, the lumbering giant of the web world. As of last year Google accounted for nearly half of all web searches with Yahoo pulling in a distant second at roughly 25%. From 1994 to 2002 Yahoo used human editors to add lists, until making the massive shift to web-crawlers following Google’s lead. It follows the standard web crawling means with a slightly less efficient algorithm than Google. Yahoo offers a much wider choice of search categories along with access to its old human directory. However, it is often thought of as second best in terms of search results.

The secret to how Google has gotten so good at generating relevant search results is exactly that, a secret. They follow the standards paradigms as many other web search engines in that they use an automated program, called a robot or spider, to trawl through the billions of webpages on the Internet. However this is where Google differ from most other search companies in that they process their data using a few choice algorithms of which PageRank is the main one. PageRank works by analysing which sites link to the page it has just crawled and assigning a weight based on how ‘important’ these pages are. In this way Google can find the pages with the most relevant data as judged by the web itself.

Google store their crawled data as shards, small chunks of information duplicated and spread across multiple facilities such that if anyone cluster fails others can take its place. They also built their own filing system to more efficiently manage these vast quantities of data.

Obviously the most important advantage of this method is that, 99.9% of times, it returns the most relevant results first. A disadvantage however can be that should a site be assigned a low PageRank, perhaps through others actions, it may find it very difficult to pull in visitors from the Google search engine.

I personally prefer the Google search engine, as the vast majority of the Internet now does. In my personal opinion it provides the best results in the quickest time with the simplest design. Also, Yahoo Maps features terrible UK mapping compared to Google Maps (which both use their respective parents search engine).

Week1: Is a blog message personal to its Author or is it public on the Internet?

2007-10-01T13:29:00.000+01:00

I think this message boils down to the idea of intellectual property and just how publishing a piece of text on the Internet can affect your rights over your own property. UK Copyright Law is pretty good at granting the individual power over their own creations, yet the Net can become an unseemly grey area over what others can do with your work.

Ultimately it is up to the blog owner to control their work. I personally release all of my work onto the public domain under the Creative Commons 2.0 license, ensuring that other can see and share them but are prohibited from using them for personal gain, and must provide full accreditation to the original creator.

Another point of view though would look at the very content of the message. A typical blog post could range from the latest news out of Redmond to what the author had for breakfast that morning. In the end you must treat a blog how you would treat a soapbox, you can stand high on it and shout any message you want, but you have to understand the implications that your message could reach a far wider audience than any other communication method before has offered.

As a final conclusion, anything posted on the internet and not protected by some form of access control should be thought of as public. The message may be personal to the author, but once it is placed within the public domain it is fair game for spiders, lechers and regular visitors.

Week0: Hello, World!

2007-09-27T15:46:00.000+01:00

In the tried and tested fashion of computer programming I find it only right that my first post should contain the words every programmer begins with. This blog is mainly to document my CUE A1W course and as such expect an update, if not more, weekly. If however you tire of reading this then head on over to my other websites, listed beneath.

HybridLogic // my personal blog and web home
Luke Lanchester // my portfolio
DIGi27 // an old games site I still run
SnakeDust // a youth politics site I co-founded

I would add these posts to my regular blog on HybridLogic, however I feel they deserve a seperation mear categorisation cannot provide. Having said that however I shall intergrate them into my doing stream which shows my recent activity on these here interwebs.

I hope you find my forthcoming posts interesting and don't hesitate to contact me.