In this letter, the error performance of an ultra-wideband (UWB) system with a hybrid pulse amplitude and position modulation (PAPM) scheme over indoor lognormal fading channels is analyzed. In the PAPM UWB system, input data is modulated onto both the pulse amplitudes and pulse positions.
北京大學(xué)ACM比賽題
The game of Scrabble is played with tiles. A tile either has a single letter written on it, or it is blank. In the latter case, the tile may be used to represent a letter of your choice. On your turn, you arrange the tiles to form a word. Each tile may be used at most once, but not all tiles need to be used. Given several Scrabble tiles and a dictionary, determine how many words in the dictionary can be formed using the given Scrabble tiles.
北京大學(xué)ACM比賽題目
In 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in which he made the following conjecture:
Every even number greater than 4 can be
written as the sum of two odd prime numbers.
For example:
8 = 3 + 5. Both 3 and 5 are odd prime numbers.
20 = 3 + 17 = 7 + 13.
42 = 5 + 37 = 11 + 31 = 13 + 29 = 19 + 23.
Today it is still unproven whether the conjecture is right. (Oh wait, I have the proof of course, but it is too long to write it on the margin of this page.)
Anyway, your task is now to verify Goldbach s conjecture for all even numbers less than a million.
電力電子環(huán)流SIMULINK模型 Notice that the Thyristor blocks have an output identified by the letter m. This output returns a Simulink vectorized signal containing the thyristor current (Iak) and voltage (Vak).
