A new journal of O.R. has been launched, and has now published two issues. This is the Iranian Journal of Operations Research, published from Tehran. On first glance, its contents are generally theoretical, but that is true of many other O.R. related journals. The first abstracts from it will appear in IAOR in early 2010.
What is not clear is hows strong the fledgling O.R. socety is in Iran. The web address suggests that there may be plans for it to develop, but the English version is limited at present.
Monday, 14 December 2009
Monday, 30 November 2009
The best statistic I have heard for a long time
BBC Radio 4 has a flagship news and current affairs programme every weekday morning called "Today". Following one interviewer's comment, the presenter commented "The best statistic I have heard for a long time". He then paused and added words to the effect that the statistic was not good news, but had been presented in a clear way so that the meaning was easy to understand. It strikes me that those of us who work with mathematical models could learn from this example.
The interview had been about the social deprivation of parts of the east of London, and the comment was made: "for every tube stop on the Jubilee line [on London Underground] going east, from Westminster to Canning Town, life expectancy decreases by one year". It is not good news. But the information is conveyed in a way that is clear, simple and easy to assimilate. It is not cause and effect. Underground stations do not affect life expectancy. But one has a clear sense that the further you travel along the line, the more social deprivation, leading to lowered life expectancy, you will encounter. And the figure of "one year" is probably a rounded version of the data ... but for the purposes of this graphical illustration, it is precise enough. Someone has found a way to present information, which is of use to planners, in a way that is easy to take in. So we can learn from the example.
But, as usual, the story above is only part of the story. The statistic has been created by using limited information and extending it. The data which had been used said that the life expectancy for residents near Westminster station was seven years more than that for people living near Canning Town. They are eight stations apart. Nobody has written abot the life expectancy at those intermediate stations. All that has been done is to draw a straight line between the two extremes and assume linearity. Even though the method is not rigorous, it is still graphic. How can we learn to strike a balance between rigour and clarity?
The interview had been about the social deprivation of parts of the east of London, and the comment was made: "for every tube stop on the Jubilee line [on London Underground] going east, from Westminster to Canning Town, life expectancy decreases by one year". It is not good news. But the information is conveyed in a way that is clear, simple and easy to assimilate. It is not cause and effect. Underground stations do not affect life expectancy. But one has a clear sense that the further you travel along the line, the more social deprivation, leading to lowered life expectancy, you will encounter. And the figure of "one year" is probably a rounded version of the data ... but for the purposes of this graphical illustration, it is precise enough. Someone has found a way to present information, which is of use to planners, in a way that is easy to take in. So we can learn from the example.
But, as usual, the story above is only part of the story. The statistic has been created by using limited information and extending it. The data which had been used said that the life expectancy for residents near Westminster station was seven years more than that for people living near Canning Town. They are eight stations apart. Nobody has written abot the life expectancy at those intermediate stations. All that has been done is to draw a straight line between the two extremes and assume linearity. Even though the method is not rigorous, it is still graphic. How can we learn to strike a balance between rigour and clarity?
Monday, 9 November 2009
Optimising a sound system
A curious story came my way, which is a piece of optimisation which has never been (and probably never will be) written up as an academic paper. But that's true of much applied O.R. all the time. Even academics who need to publish find that some of their studies are simply unpublishable. The story came from Dustin Curtis' blog.
He described meeting a sound engineer who set up ambient sound systems for Walt Disney World. Here's an extract:
In the mid 1990’s, the park started researching the problem. It would eventually find no existing solution, so the engineers had to design and construct, on their own, one of the most complex and advanced audio systems ever built. The work paid off: today, as you walk through Disney World, the volume of the ambient music does not change. Ever. More than 15,000 speakers have been positioned using complex algorithms to ensure that the sound plays within a range of just a couple decibels throughout the entire park. It is quite a technical feat acoustically, electrically, and mathematically.
Just think what O.R. tools would be needed for that sort of optimisation and design!
He described meeting a sound engineer who set up ambient sound systems for Walt Disney World. Here's an extract:
In the mid 1990’s, the park started researching the problem. It would eventually find no existing solution, so the engineers had to design and construct, on their own, one of the most complex and advanced audio systems ever built. The work paid off: today, as you walk through Disney World, the volume of the ambient music does not change. Ever. More than 15,000 speakers have been positioned using complex algorithms to ensure that the sound plays within a range of just a couple decibels throughout the entire park. It is quite a technical feat acoustically, electrically, and mathematically.
Just think what O.R. tools would be needed for that sort of optimisation and design!
Monday, 19 October 2009
Smeaton's Tower
On 16th October 1759, Smeaton's lighthouse on the Eddystone Rocks (14 miles out of Plymouth) was illuminated for the first time. The original lighthouse has been dismantled and re-erected on Plymouth Hoe.
To mark the anniversary of this pioneering building, it was illuminated by candle-power once again on the evening of 16th October 2009.
The lighthouse featured on British one penny coins until 1970:
Why mention this in a blog about operational research? Logistics. 250 years ago, the lighthouse was illuminated by 24 candles. Three lighthouse keepers had the job of ensuring that these were lit all night, every night. They were dependent on supplies from the mainland, and the lighthouse was notoriously difficult to reach. Sometimes the keepers went for weeks without fresh supplies. So, here's the problem: how did the stock controllers plan for candles, food and supplies for the lighthouse? Apart from fresh fish, there were no other sources of food on the Eddystone Rocks. Sometimes the keepers were starving when boats reached them from the mainland. It makes academic models of inventory management seem ... academic.
And now for something different:
The Keeper of the Eddystone Light
My father was the keeper of the Eddystone light
And he slept with a mermaid one fine night
Out of this union there came three
A porpoise and a porgy and the other was me!
Yo ho ho, the wind blows free,
Oh for the life on the rolling sea!
One night, as I was a-trimming the glim
Singing a verse from the evening hymn
I head a voice cry out an "Ahoy!"
And there was my mother, sitting on a buoy.
Yo ho ho, the wind blows free,
Oh for the life on the rolling sea!
"Oh, what has become of my children three?"
My mother then inquired of me.
One's on exhibit as a talking fish
The other was served in a chafing dish.
Yo ho ho, the wind blows free,
Oh for the life on the rolling sea!
Then the phosphorus flashed in her seaweed hair.
I looked again, and my mother wasn't there
But her voice came angrily out of the night
"To Hell with the keeper of the Eddystone Light!"
Yo ho ho, the wind blows free,
Oh for the life on the rolling sea!
by: Charles Wingate
Wednesday, 9 September 2009
How many items make a pack? part 3
Two more odd sized packs for the record.
Tesco supermarket is selling packs of Broccoli with a nominal 335gm ... why? .. so they can sll them at 50p each and display a price of £1.50 per kilo!
A mail order company offered me packs of paper hand wipes (see part 2) with 260 in a pack.
Tesco supermarket is selling packs of Broccoli with a nominal 335gm ... why? .. so they can sll them at 50p each and display a price of £1.50 per kilo!
A mail order company offered me packs of paper hand wipes (see part 2) with 260 in a pack.
Tuesday, 1 September 2009
How many items make a pack? part 2
Today I gave blood (it was, according to the records, my 66th time). The UK blood donation service collects a donation of 470ml. Why 470? I asked, being an Elephant's Child with insatiable curiosity (or "'satiable curtiosity" as Kipling wrote).
The service decided on 470 because it was found to be an amount that a healthy donor of minimum weight can safely give; if it were to be increased, then it would prevent some donors from giving. If it were reduced, then handling it (because each donation is divided into parts) might become difficult. So it is 470ml (or equivalent because it is weighed) for good reasons.
Monday, 24 August 2009
How many items make a pack?
From time to time, I observe a package or a product in a shop or elsewhere, and wonder why the manufacturers have selected a particular size or number of items.
On my website, there are pictures from the ROCARO conference in Niamey in 2004, including a picture of a beer bottle holding 48cc. Why 48?
The paper towels in the washroom here come in packs of 180 towels. Why 180?
British food packaging is plagued with anomalous sizes. Jam, marmalade and numerous other items are sold in packs weighing 454gm or 340gm (equivalent to 1 pound, or 12 ounces). Flour is sold in bags weighing 1.5kg -- a reminder that it was formerly sold in bags weighing 3 pounds (why 3?)
For the final consumer, these assorted sizes are little more than an irritant; but within a supply chain, they can be more serious.
Now I shall start to collect and report odd-sized packs.
On my website, there are pictures from the ROCARO conference in Niamey in 2004, including a picture of a beer bottle holding 48cc. Why 48?
The paper towels in the washroom here come in packs of 180 towels. Why 180?
British food packaging is plagued with anomalous sizes. Jam, marmalade and numerous other items are sold in packs weighing 454gm or 340gm (equivalent to 1 pound, or 12 ounces). Flour is sold in bags weighing 1.5kg -- a reminder that it was formerly sold in bags weighing 3 pounds (why 3?)
For the final consumer, these assorted sizes are little more than an irritant; but within a supply chain, they can be more serious.
Now I shall start to collect and report odd-sized packs.
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