19

20

u U

13

14

15

16

17

18

u

(

m

/

s

)

0.27 0.28 0.29 0.30 0.319

10

11

12

time series (sec)0.4

x/c=0.3 x/c=1 x/c=4x/c=7

0.1

0.2

0.3

x/c 7

2009 2010 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 140.0

Velocity fluctuations (m/s)

7

, ,

, .

.. S1(t)=5t, S2(t)=20t2, S3(x,y)=3x+2xy+10y2

.. ( )N

1( )sin[2 ( ) ( )]

N

i i ii

A t F t t

( (.., )

, ,

( ) ( ...)

,

, ,

Acos

p=1/F A

t0

x(n) x(t)x(n)=x(nt)

Discretetimesignal

t0 1 2 3 4 5 6 7 8 9

tT 2T 5T 9T t=nT

x(n)

D i i i

Digitalsignal

, ,

Deterministic: Random: ( , ) n0 1 2 3 4 5 6 7 8 9-1

radians/secp=1/FA

Acos( ) cos( ),

12 F=

X t A r t

F

t0

Acos

2 , Fp

FT

/sec

( ) ( ), 1/p pX t T X t T F

, ,

radians/( ) cos( )x n A n

( ) cos( ), x n A n n

( ) ( )=/6f=1/12 A

2 f n0

(f=k/N N:) x(n+N)=x(n)

/-A

(f=k/N, N:). x(n+N)=x(n)cos[2f0(N+n)+]=cos(2f0n+)

2 2 kf N k f N

31 3060 2f N f N

0 02 2f N k f N

, , 21=2k

1 1 2 2 60, 260 60f N f N

( Shannon) , .

fm , m fm .

(Shannon) f fm , . fs >=2 fm

fs Nyquist.

f f

, ,

fs < fm ( Aliasing)

, , , , , . (Digital Signal Processing, DSP), (real time) :

Inputfilter

ADCwith sample

and hold

Digital Processor DAC

Outputfilter

x(t) y(t)x(n) y(n)

x(t) , (aliasing) .

and hold

(ADC Analog to Digital Converter), . (sample and hold). ( ) x(n)

. (DSP Digital Signal Processor) (IC). y(n) , DAC (Digital to Analog Converter) y(t).

, ,

( g g ) y( ) (DSP) ADC DAC.

, , , . :1. ,

.2. 2 , ,

bits .3. .

x(t)01011x(n) xq(n)

A/D Converter

Sampler( ) ( )

CoderQuantizer

, ,

(Sampling) (Quantization) (Coding)

x(n)( )

1.0 x(n)x(t)

1.0

x(t)

0 4

0.6

0.8

0.6

0.8

q

0 1 2 3 4 5 6 7 8 9

0.2

0.4

0 1 2 3 4 5 6 7 8 9

0.2

0.4

n0 1 2 3 4 5 6 7 8 9

T =1 secT

n0 1 2 3 4 5 6 7 8 9

:2 1 2

fs fsB B

V Vq : 12 2

fsB

Vq V : ADCVfs: ADCB: bits ADC

*

, ,

* *

ADC 12 bits ( 5 5) V ADC 12 bits (5 5) V . , x500 Seebeck 50 V/oC [1600]

: 1210 2.44

2 2fsB

Vq mV

[1600].

V 10 V lt 122 2B

: 1.22 2q mV

Vfs=10 VoltsB=12

2

E=a, : , = Seebeck, T=

x500 ~ Vfs=10/500=0.02 Volts q=0.02/212=4.910-6 V

E1600=4 910-6 *1600=7 810-3 V E=a => =E/ a =156 oC

, ,

E 4.9 10 1600 7.8 10 V E a > E/ a 156 C