iki.fi/o

Ideas

Sometimes I get an idea that I think may be worth something, maybe not much, but something. But then I forget it. Better write it down, here.

2010-05-18

A theory on how molecules inside a cell manage to be in the part of the cell where they are needed. If macromolecules A and B bind to each other and B and C also bind to each other, and the two binding reactions need not compete with one another, then obviously A and C will also end up close together, via B. This must be a very common way to create a tight organization between macromolecules. But what about when a more loose organization is required, let’s say when the rather freely diffusing tRNA’s are needed where translation takes place. It seems unlikely that the contents of a cell would be an inefficient homogeneous porridge of macromolecules. Perhaps affinities between macromolecules brings about organization. To describe the affinities between N species of macromolecules, one would need at least an N x N triangular matrix of affinity constants. It would be interesting to simulate such a system, and to see if compartmentalization takes place by itself without boundaries. If a macromolecule of an unknown purpose is found to have affinity to several components of a cellular process, then the guess can be made that it probably contributes to the process somehow. These affinities probably wouldn’t need to be very strong. Some types of metabolic and transport systems could perhaps be shown to be more effective in an internally organized cell.

2010-04-07

A directional microphone that is a 3D configuration of multiple omnidirectional microphone elements. The signals from the different elements are made to be in phase by using digital delay lines. The microphone can also be made resistant to turbulences caused by wind by temporarily muting the affected elements, and by surrounding each with a chassis that protects it against wind from a certain direction. The direction would be different for each element.

2010-02-24

A method for training artificial neural networks to generate missing data within a variable context. As the idea is hard to put in a single sentence, I will use an example:

An image may have missing pixels (let’s say, under a smudge). How can one restore the missing pixels, knowing only the surrounding pixels? One approach would be a “generator” neural network that, given the surrounding pixels as input, generates the missing pixels.

But how to train such a network? One can’t expect the network to exactly produce the missing pixels. Imagine, for example, that the missing data is a patch of grass. One could teach the network with a bunch of images of lawns, with portions removed. The teacher knows the data that is missing, and could score the network according to the root mean square difference (RMSD) between the generated patch of grass and the original data. The problem is that if the generator encounters an image that is not part of the training set, it would be impossible for the neural network to put all the leaves, especially in the middle of the patch, in exactly the right places. The lowest RMSD error would probably be achieved by the network filling the middle area of the patch with a solid color that is the average of the color of pixels in typical images of grass. If the network tried to generate grass that looks convincing to a human and as such fulfills its purpose, there would be an unfortunate penalty by the RMSD metric.

My idea is this (see figure below): Train simultaneously with the generator a classifier network that is given, in random or alternating sequence, generated and original data. The classifier then has to guess, in the context of the surrounding image context, whether the input is original (1) or generated (0). The generator network is simultaneously trying to get a high score (1) from the classifier. The outcome, hopefully, is that both networks start out really simple, and progress towards generating and recognizing more and more advanced features, approaching and possibly defeating human’s ability to discern between the generated data and the original. If multiple training samples are considered for each score, then RMSD is the correct error metric to use, as this will encourage the classifier network to output probabilities.

Artificial neural network training setup

2010-02-18

A graphic design methodology that projects a 2D pattern of silhouettes as objects onto a 3D landscape and renders the scene using 3D methods. For example, a set of squares is turned into a city of facades on a landscape, perhaps even with perspective.

2010-01-27

Exact coordinates for computer aided design (CAD). If a CAD program stores coordinates internally as floating point, then movement of objects such as rotations will accumulate error in the inexact numerical coordinates. This could result in two points not coinciding when they should, if they were subjected to different transformations. Perhaps the only way to avoid this would be to store the coordinates exactly, including things like square roots and such in a formula type of an expression. When possible, the expression would be simplified. For example sqrt(2)*sqrt(2) would become 2. The drawback is that everything would become slower.

2010-01-13

Terminator yeast for carbonation of bottled beverages. Carbonation of bottled beverages by yeast has the problem that the yeast will use up all the sugar, and usually it would be good to leave at least some sweetness. So, engineer a yeast that stops fermenting after, let’s say, a number of growth cycles. Additionally, to reduce the amount of sediment, the yeast could be made to waste energy instead of using it for growth. The trigger of this could be related to growth cycles. The best would be detection of pressure, stopping the metabolism of the yeast when there is enough pressure in the bottle. A mechanism for pressure sensing could perhaps be evolved by switching between different food sources and by signaling the switch beforehand by a pressure change. Alternatively the trigger could be CO_2 concentration. Reading a bit on the topic, some researchers have produced cold-sensitive strains of baker’s yeast by using nystatin, which presumably kills growing yeast cells.

2009-10-04

Singing brakes for bicycles. By etching sound wave patterns into the rim, the rim brake could be made to produce tones, maybe even arbitrary sounds.

2009-09-12

Text readable in the order of contraceptive pills

Text readable in the order of contraceptive pills

This is intended as an artistic effect, not actual labeling of pills. Uh, sounds like such an obvious idea that someone probably already used it.

2009-08-30

Create genetically manipulated trees with branches in line and only on two sides, to get more knotless lumber

  • Does the tree twist and loose the polarity? Now this is a possibility.
  • How to do it? Should look into developmental biology.
  • Does the tree get enough light? The branches can branch also horizontally so it wouldn’t be just a flat tree. And even if it’s a flat tree it gets about 64 % of the light compared to a normal tree.
  • Does it replace normal trees in the ecosystem? Unlikely, because it won’t be as effective in collecting light as normal trees.

2007-10-26

A musical wind instrument with electro-acoustic feedback

  • How is the feedback created? By a microphone and a  small loudspeaker.
  • How does one get different notes? The delay length is adjusted by the player by pressing keys.
  • How is the feedback delay made? It is either an electronic/digital delay or an array of microphones is used.
  • What if the speaker is of poor quality? Compensate for example by low-pass filtering. An adjustable filter would also allow coloration of the tone.

Euro coins as standard weights

What if you suddenly need a scale, accurate to one gram? Here is the solution, in case you live in the euro zone. (Something like this has actually been done before!)

The physical mass of each euro coin is actually standardized. So they can be used to measure mass of other objects using a balance. Here’s how I measured 3 grams of salt. See the figure 1 below. A thin black string goes around a round pen that may freely roll on top of two pens well leveled on a table using a pencil and a book. On each end of the string hang two bags, by hooks made of staples (was out of paper clips). One bag is for the coins and one bag is for the sample (an empty bag is included in the other end for balance). The first coin bag contains two 20 cent coins. That’s 11.48 grams of coins. The other coin bag contains a 2 euro coin with a mass of 8.50 g. The difference is 2.98 g, near to what we wanted, 3 grams. Salt is added to the sample bag (next to the 2 euro bag) until the pen no longer rolls. I do admit that it is a bit cumbersome to use, but if you have nothing else, it still works. A balance made from a rod would be more reliable, easier to handle, and could be calibrated so that different weights are measured by moving the position of the standard weight.

Figure 1. Measuring 3 grams of salt with a cheap and lousy balance scale.

If you want to measure other weights (0.5-50 g), you can use table I as a reference. No 1 cent and 2 cent coins are used in the combinations, because those coins are not available in Finland. If you want the extra convenience and accuracy provided by them, have a look at table II. The tables also give error limits at two standard deviations. The error analysis is based on the presumption of 0.5 % systematic and 0.5 % standard deviation random error in the masses of the coins, agreeing with an analysis on Belgian 1 euro coins. The coin combinations in the tables were found by first systematically searching for the combination that gives the most accurate mass, and by then finding the most convenient coin combination that gives at most 25 % more error.

Note that this method of measuring the mass is better suited for weighing a wanted amount of a substance rather than for determination of an unknown mass.

Table I. Euro coins as standard weights for 0.5-50 g, excluding 1 cent and 2 cent coins

Standard weights Negative standard weights
and sample
Mass of sample that
balances the scale
Error
at 2 std.dev.
10c5c 1esample 0.5 g ±0.2 g
2e 1esample 1 g ±0.2 g
20c 10csample 1.5 g ±0.3 g
50c 20csample 2 g ±0.2 g
20c10c 1esample 2.5 g ±0.3 g
1e5c 2esample 3 g ±0.3 g
1e 5csample 3.5 g ±0.2 g
5c sample 4 g ±0.1 g
2e 5csample 4.5 g ±0.2 g
50c20c 2esample 5 g ±0.3 g
20c5c 10csample 5.5 g ±0.2 g
50c5c 20csample 6 g ±0.2 g
2e20c 50csample 6.5 g ±0.3 g
1e10c5c 2esample 7 g ±0.3 g
1e sample 7.5 g ±0.1 g
10c5c sample 8 g ±0.1 g
2e sample 8.5 g ±0.1 g
1e20c 10csample 9 g ±0.3 g
20c5c sample 9.5 g ±0.3 g
20c10c sample 10 g ±0.3 g
1e50c 10csample 11 g ±0.4 g
50c10c sample 12 g ±0.2 g
2e2e 5csample 13 g ±0.3 g
2e20c5c 10csample 14 g ±0.3 g
2e2e20c 50csample 15 g ±0.4 g
2e1e sample 16 g ±0.2 g
2e2e sample 17 g ±0.2 g
2e2e2e 1esample 18 g ±0.3 g
1e50c5c sample 19 g ±0.4 g
2e1e5c sample 20 g ±0.3 g
2e2e5c sample 21 g ±0.3 g
2e50c20c sample 22 g ±0.3 g
2e2e50c5c 20csample 23 g ±0.4 g
2e1e10c5c sample 24 g ±0.3 g
2e2e10c5c sample 25 g ±0.3 g
2e50c20c5c sample 26 g ±0.3 g
2e2e20c10c sample 27 g ±0.4 g
2e1e50c10c sample 28 g ±0.4 g
2e2e50c10c sample 29 g ±0.4 g
2e50c20c10c5c sample 30 g ±0.4 g
2e2e2e20c5c 10csample 31 g ±0.4 g
2e2e2e2e20c 50csample 32 g ±0.5 g
2e2e2e1e sample 33 g ±0.3 g
2e2e2e2e sample 34 g ±0.3 g
2e2e2e2e2e 1esample 35 g ±0.5 g
2e2e2e2e50c 20csample 36 g ±0.5 g
2e2e2e1e5c sample 37 g ±0.4 g
2e2e2e2e5c sample 38 g ±0.4 g
2e2e2e50c20c sample 39 g ±0.4 g
2e2e2e2e50c5c 20csample 40 g ±0.5 g
2e2e2e1e10c5c sample 41 g ±0.4 g
2e2e2e2e10c5c sample 42 g ±0.4 g
2e2e2e2e2e2e 10c5csample 43 g ±0.5 g
2e2e2e2e20c10c sample 44 g ±0.6 g
2e2e2e1e50c10c sample 45 g ±0.5 g
2e2e2e2e50c10c sample 46 g ±0.5 g
2e2e2e2e2e2e 5csample 47 g ±0.6 g
2e2e2e2e2e20c sample 48 g ±0.7 g
2e2e2e2e1e50c sample 49 g ±0.7 g
2e2e2e2e2e1e sample 50 g ±0.5 g

Table II. Euro coins as standard weights for 0.5-50 g, including 1 cent and 2 cent coins

Standard weights Negative standard weights
and sample
Mass of sample that
balances the scale
Error
at 2 std. dev.
5c1c 20csample 0.5 g ±0.2 g
10c 2csample 1 g ±0.1 g
5c 1csample 1.5 g ±0.2 g
50c 20csample 2 g ±0.2 g
10c1c 5csample 2.5 g ±0.1 g
2c sample 3 g ±0.1 g
20c 1csample 3.5 g ±0.2 g
5c sample 4 g ±0.1 g
1e 2csample 4.5 g ±0.2 g
20c1c 2csample 5 g ±0.1 g
50c 1csample 5.5 g ±0.1 g
50c1c 10csample 6 g ±0.2 g
20c2c 1csample 6.5 g ±0.1 g
5c2c sample 7 g ±0.1 g
1e sample 7.5 g ±0.1 g
10c5c sample 8 g ±0.1 g
2e sample 8.5 g ±0.1 g
20c10c2c 5csample 9 g ±0.2 g
10c2c1c sample 9.5 g ±0.1 g
50c1c sample 10 g ±0.2 g
10c5c2c sample 11 g ±0.2 g
20c5c1c sample 12 g ±0.2 g
1e50c 1csample 13 g ±0.2 g
50c5c1c sample 14 g ±0.2 g
50c10c2c sample 15 g ±0.2 g
2e1e sample 16 g ±0.2 g
2e2e sample 17 g ±0.2 g
2e10c2c1c sample 18 g ±0.2 g
2e1e2c sample 19 g ±0.3 g
2e2e2c sample 20 g ±0.3 g
2e2e5c sample 21 g ±0.3 g
2e50c20c sample 22 g ±0.3 g
2e1e5c2c sample 23 g ±0.3 g
2e2e5c2c sample 24 g ±0.3 g
2e2e10c5c sample 25 g ±0.3 g
2e50c20c5c sample 26 g ±0.3 g
2e2e50c1c sample 27 g ±0.4 g
2e2e10c5c2c sample 28 g ±0.4 g
2e2e20c5c1c sample 29 g ±0.3 g
2e2e1e50c 1csample 30 g ±0.3 g
2e2e2e50c 1csample 31 g ±0.3 g
2e2e50c10c2c sample 32 g ±0.4 g
2e2e2e1e sample 33 g ±0.3 g
2e2e2e2e sample 34 g ±0.3 g
2e2e2e2e2e 1esample 35 g ±0.5 g
2e2e2e1e2c sample 36 g ±0.4 g
2e2e2e2e2c sample 37 g ±0.4 g
2e2e2e2e5c sample 38 g ±0.4 g
2e2e2e50c20c sample 39 g ±0.4 g
2e2e2e1e5c2c sample 40 g ±0.4 g
2e2e2e2e5c2c sample 41 g ±0.4 g
2e2e2e2e10c5c sample 42 g ±0.4 g
2e2e2e2e2e2e 10c5csample 43 g ±0.5 g
2e2e2e2e50c1c sample 44 g ±0.5 g
2e2e2e1e50c10c sample 45 g ±0.5 g
2e2e2e2e50c10c sample 46 g ±0.5 g
2e2e2e2e2e1e 2csample 47 g ±0.5 g
2e2e2e2e2e2e 2csample 48 g ±0.5 g
2e2e2e2e2e10c1c sample 49 g ±0.5 g
2e2e2e2e2e1e sample 50 g ±0.5 g

Powered by WordPress - Hosted by SuniSoft oy