How many nodes for self-organizing maps?

I'm learning self-organizing maps, however I don't know how to determine the number of nodes by which the data will be well classified. Which metric may be useful?

09 October 2016 668 6 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

Is there any effect of different colours of light (white, red, yellow, blue etc.) on the rate of photosynthesis? If yes, why?

Light is inevitable for the process of photosynthesis reaction. Naturally sunlight plays the vital role for this process. Light may be of different colours like white, red, yellow, blue etc....

02 March 2021 7,890 2 View

In an eye with Tyndall, does each dot correspond to an individual cell?

When you observe the presence of Tyndall in an inflamed eye: Does each of the small floating dots correspond to an individual cell or to an aggregate of cells? Does a conventional slit lamp have...

27 February 2021 6,326 2 View

How can I obtain time series data by country on night-time light (brightness) ?

Hi everyone, Please, how can I obtain time series data by country on night-time light (brightness) ? I've tried, but so far all I can find are maps. I am looking for numerical data, especially in...

24 February 2021 8,625 4 View

What are difference between laser diodes, simple light emitting diodes and power light emitting diodes when operated in the visible spectrum ?

I want to illuminate a scene (small space) using LED to capture photographs or videos of some tiny objects inside the space. But am not sure if I should use a Laser LED, or simple LED or power...

22 February 2021 4,240 4 View

How to interpret this FTIR spectrum of pyrolyzed hydrochar?

20 February 2021 2,840 3 View

Can I arbitrarily take a cycle number of 40 for the gene that was not expressed at all in qPCR results calculation?

I ran RT-qPCR for a control and a treated group and it appears that my gene of interest was not expressed at all in any of the subjects in the control group. So I was wondering if I could...

20 February 2021 6,243 10 View

No title

The regenerated cellulose film was prepared by zinc chloride/H2O system. The zinc chloride had been washed away in the regeneration process, and the wet film which was not dried had uniform...

18 February 2021 9,538 1 View

How do I plot Pressure against crank angle degree in Fluent?

18 February 2021 8,390 3 View

How to get rough estimation of the concentrations of Oxygen and moisture inside the glove box?

Dear colleagues, I was just wondering if you can suggest a good method to get a rough estimation to the concentration of O2 and H2O inside the glove box as unfortunately, our glove box doesn't...

17 February 2021 1,012 3 View