
-2-
Denote
4
1234 1234
:{(, , , ): , , , 0}ssss ssss
+
=≥ . For
2
F ⊂ and
4
1234
(, , , )sssss
+
=∈
, let
1
( ) inf ( ) :{ } is a -cover of by triangles
s
ii
i
Fp F
δ
δ
∞
=
⎧⎫
=ΔΔ
⎨⎬
⎩⎭
∑
H
,
where
3
12 4
12 3 4
(): () () () ()
s
ss
iiiii
pppppΔ= Δ Δ Δ Δ .
Clearly, as
decreases, ()
s
F
δ
H
increases and so ()
s
F
δ
H
approaches a limit as
0
→
, we write
0
() lim ()
ss
FF
δ
δ
→
=
HH
.
We can prove that the set function
H
is a metric outer measure. So the measure
H
is a Borel
measure on plane.
In 1919, Hausdorff introduced [1] a concept of Hausdorff dimension which can distinct two null Lebe-
sgue sets. For example, let
denote the rational numbers and C denote the Cantor set. Both of them
are Lebesgue null set, while
dim 0
H
and
log 2
dim
log 3
H
C = .
In 1988, Rogers [2] introduced a concept of Dimension print, which contains more detailed information
than the Hausdorff dimension. For instance, Dust-like set formed by the product of two uniform Cantor
sets of Hausdorff dimension
34 and Stratified set formed by the product of a uniform Cantor set of
Hausdorff dimension
12
and a line segment have the same Hausdorff dimension
32
but with different
dimension prints. Dimension print was introduced in [5] and was further studied by [3].
Now we give the definition of dimension print due to Rogers as follows. Let
U be a rectangle on plane
and
() ()aU bU≥ be the length of the sides of
U
. Let
s
and t be the non-negative numbers. For any
subset
F of
2
, let
(,)
1
( ) inf ( ) ( ) :{ } is a -cover of by rectangles
st s t
iii
i
FaUbUU F
δ
δ
∞
=
⎧⎫
=
⎨⎬
⎩⎭
∑
P
.
By letting
0
→ , we get a Hausdorff type measure
(,)
t
P
on
2
, we write
(,) (,)
0
() lim ()
st st
FF
δ
δ
→
=
PP
.
The dimension print associated with
(,)
t
P
is defined as
(,)
print( ) : ( , ): 0, 0, ( ) 0
st
Fstst F=≥≥ >
P
.
The following properties are well known for us.
(1) If
12
FF⊂ , then
12
print( ) print( )FF⊂ .
(2)
i
print ( ) (print )
ii i
FF
∪∪ .
(3) If
(,) printst F∈ , and
''
,stsatisfies
''
st st
≤+and
'
tt
, then
''
(,) print()st F∈ .
In this paper, we introduce a new dimension print associated with
H
as follows. For a subset F of
2
,
let
4
print ( ) : : , ( ) 0
s
Fss F
∗
+
∈>
H
. (1.1)
We will study the relations between
print ( )F
∗
and print( )F in section 3. Several comments are
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