26 September, 2010

foreign sim cards work better

international mobile phone roaming has a strange property: in any particular location, a foreign roaming sim card gets better coverage rather than a local sim card: generally all local networks are available for a foreign sim card to connect to, but only one network is available for the local network.

12 September, 2010

extreme diving for work

Some quotes from a paper on the Reduced Gradient Bubble Model for scuba diving decompression calculation which I've been looking at recently. Most of what I've looked at so far has been recreational no-decompression diving, so the dives described below seem quite extreme. (for comparison, the deepest recreational dives are to about 40 metres = 130 feet, and for a maximum of 8 minutes)

Pearling fleets, operating in the deep tidal waters off northern Australia, employed Okinawan divers who regularly journeyed to depths of 300 f sw for as long as one hour, two times a day, six days per week, and ten months out of the year.
With higher incidence of surface decompression sickness, as might be expected, the Australians devised a simple, but very effective, in-water recompression procedure. The stricken diver is taken back down to 30 fsw on oxygen for roughly 30 minutes in mild cases, or 60 minutes in severe cases. Increased pressures help to constrict bubbles, while breathing pure oxygen maximizes inert gas washout (elimination).

Similar schedules and procedures have evolved in Hawaii, among diving fishermen [...] Harvesting the oceans for food and profit, Hawaiian divers make beween 8 and 12 dives a day to depths beyond 350fsw.
Consistent with bubble and nucleation theory, these divers make their
deep dive first, followed by shallower excursions.
In a broad sense, the final shallow dives have been tagged as prolonged safety stops.

05 September, 2010

new photo frame

On sale, €33 at Media Markt, I got a digital photo frame.

It has a slot for a USB stick, and for various memory cards. It looks like an upgraded version of one I bought for my parents a year ago, where the USB interface worked well but the card reader seemed unreliable. So I put one of the many free conference USB sticks in my collection in.

People seem to have an instinct to unplug these things continuously. Why? You don't put curtains over the print photos on your wall and only open the curtains for a few minutes at a time to look at the photos behind.

The frame is 16:9 aspect ratio. My camera makes files of ratio 4:3 (or 3:4 in landscape). (apparently print photos are usually 3:2. my camera has a helper mode that overlays grey bars on screen to show you 3:2 ratio. But it doesn't have a similar mode for 16:9)

On my laptop, I have gimp. But I found that Preview is good enough for rough cropping of photos to size. That's the technical side of cropping easily dealt with. On the artistic side, though, its hard to get in the habit of evaluating photos for such cropping - photos that I think of as "too much space at the top / bottom" are ones that are perfect for this frame, and photos that fill the frame nicely are too full for cropping.

As the frame is so low resolution (~ VGA) its possibly to crop smaller details from a frame, so that you end up with an entirely new picture rather than something that looks like the original photo but a bit cropped.

I've had a desire but not enough motivation to actually look at my photos from a cropping perspective. Perhaps this will provide the motivation.