N

e ( u )

e ( σ )

100

4.67 × 10−1

4.30 × 10−1

200

1.11 × 10−2

1.04 × 10−1

400

5.92 × 10−3

7.26 × 10−2

1600

8.61 × 10−4

3.57 × 10−2