5 ก
. . ก !"# $%
#& '& $ & $ ()ก$*
CSC662 Data Mining, Data Warehouse and
Visualization
18 .. 2550 Concept description 2
ก1*2"34""5
"! ' ก(1
ก!1!" 5$
ก &*$&ก !3" ก(1
"6!7 ก! " 8!ก! &ก1 " '!(!
ก9"5 '
:
!2;"*
18 .. 2550 Concept description 3
ก1*2"34""5 (Descriptive mining)<!ก=
&4!4!ก"5 !& * ก ;!ก' '8! ก ก3!
>!34>(8 >'4"* ก>*%8>!ก"5 4ก8
ก"5 ก (Characterization) ก"5 ก (Comparison)
ก1*2"34"1! (Predictive mining)<!ก=&
4!4!ก4 (model) !1>'41!34">!"!&8 ก8"!
&ก8*8 Descriptive mining ก Predictive mining
18 .. 2550 Concept description 4
ก1*2"34""5
34">'48(1<!4""8>!3"Multidimensional data model 8((ก 34"<! *2"!"
กก&4!<!" ! กก1*! "$2"ก&4!*
&44(ก"
>'4ก Multidimensional data modelก! ' (! >'4ก
sum, count, max, min
>'4ก4"ก 4>'42" (&4(ก8" 4>'44"&
34>(>! 4"ก ก3"5ก ( (
ก1*2"34""5 ก &4(ก"
18 .. 2550 Concept description 5
*2"!ก !
5$4<!ก34" ก(( <!
>'4 1! !ก กก ! drilling, pivoting, slicing dicing
ก8ก !
<!ก( ก" ! ก ก( ก4>'4
<!ก &*$2" ก ก2"ก (") 4>'4
( กก '! ? ?4"!ก ก( กก 8? ?4"!
&*$กก(3"34"ก 8ก (กก(3"34"
&ก8*8 กก "
18 .. 2550 Concept description 6
ก!34">*4"8>!
34"">! 8 ("ก) >'4ก"&&
8 3=;!
5ก
1* "1
1* ก1*2"34" >'4 5ก"! ' ก(1 (Attribute- oriented induction)
* กก!34">*4"8>!
ก"&&
:!
" ก "" %@!
ก '>*8
' ;!
( *
18 .. 2550 Concept description 7
34"กก$ (data cube)
>'4ก count( ), sum( ), average( ), max( ), min(), product() ( (Generalization) >'4roll-up
( ก>! 8"(Specialization)>'4 drill-down
34"(1ก
8:>'4ก ก(18>'8(1!! *2" "2!
>'4!$&4!*&4?=4"" ก$ >'4ก 1! !ก"
roll-up, drill-down, pivot, slice and dice
ก>'4กก$2"3!
18 .. 2550 Concept description 8
5ก"! ' ก(1 Attribute-oriented induction (AOI) >'44ก ก(1 ;<!(1!!8>'8(1!!
3 ;!"! 5
(ก 34"' !5$ 4! (initial relation)
ก1( ก(1ก!ก(ก88" >!
กก ก?;1?4"!3"!34""( >*4ก !>!83"&:
(! *!=(ก8!) *2"ก !>!8(1!! (!1&8 <!
(1!!กก !) *2" ;!?;1ก ! ก8
!?;1(!2"!3ก( '8! ((1!! ก(18กก !)
"! ' ก(1 (AOI)
18 .. 2550 Concept description 9
Data focusing: & 2"ก ก(1ก6>! initial relation Generalization:
Attribute removal:ก1( ก(1 :4
ก(1 ( A &8ก8ก !ก
8: *2" A :ก"5 4 ก(1"2!
Attribute generalization:&8>! ก(1 :4
ก(1&8ก8ก !ก
ก83" 1! !ก! ก(1>*4"8>! 4
ก( ก ก(13" AOI
18 .. 2550 Concept description 10
Attribute generalization threshold control: "(ก1*!*&8 1* 8 ก(1*2"ก1*!&8>!A!34"' !5$
&8 ก8"ก(1!!&88ก !" 43" ก(1
(distinct values)'8!&8 distinct value = 1 <! ก(18!8
!>( *2"&8ก8ก !ก(distinct values > 8)<! ก(1
"กก !>*41ก3=;!>!"3" ก(1
Generalized relation threshold control: ก1*!ก1! ; A!34"' !5$ & (1!!&88ก !3"ก ก(18
*8( >*4"8>! *2"8 ก3=;!(1>*4(1!!
ก(1!4" ( ) *2"ก((1>*4(1!! ก (1ก3=;! ( )
&&ก1>*4"8>! 3" AOI
18 .. 2550 Concept description 11
InitialRel: 3 ;!ก4 initial relation
PreGen: 3 ;! &*$ก1>*4<! '8!กก1( *2"ก ก(1>*4"8>!
PrimeGen: 3 ;!2"ก!(ก PreGen 2">'4ก initial relation
1>*4ก “prime generalized relation” ( กก 34"?;1?4"!
ก4 ก(1ก63"!?;1?4"!
Presentation: (1) >*4* (2) ก*! (3) ก4ก9
!1!"4#!5
3 ;!"! 5"! ' ก(1
18 .. 2550 Concept description 12
Name Gender Major Birth-Place Birth_date Residence Phone # GPA Jim
Woodman
M CS Vancouver,BC, Canada
8-12-76 3511 Main St., Richmond
687-4598 3.67 Scott
Lachance
M CS Montreal, Que, Canada
28-7-75 345 1st Ave., Richmond
253-9106 3.70 Laura Lee
…
F
…
Physics
…
Seattle, WA, USA
…
25-8-70
…
125 Austin Ave., Burnaby
…
420-5232
…
3.83
… Removed Retained Sci,Eng,
Bus
Country Age range City Removed Excl,
VG,..
Gender Major Birth_region Age_range Residence GPA Count
M Science Canada 20-25 Richmond Very-good 16 F Science Foreign 25-30 Burnaby Excellent 22
… … … … … … …
Birth_Region Gender
Canada Foreign Total
M 16 14 30 F 10 22 32 Total 26 36 62 Prime
Generalize d Relation Initial Relation
"8ก>'4 AOI
18 .. 2550 Concept description 13
& !5$ (Generalized relation)
& !5$3" ก(1
34 (Cross tabulation)
3"& !5$&8 (&4ก contingency tables)
!#!5 (Visualization)
! # !# ก !# 8 !# 4!
ก9 ก(1!! (Quantitative characteristic rules) <!ก94"&8ก34" '8!
grad(x) ∧ male(x) ⇒ birth(x)=“Thai” [t:95%] ∨ birth(x)=“foreign” [t:5%]
ก!1!" 5$
18 .. 2550 Concept description 14
ก!1!"& !5$
15 300
12 250
" ก 28 450
&" "$ 120 1,000 &" "$ 150 1,200
" ก &" "$ 200 1,800 (
) ()
"?
"?
18 .. 2550 Concept description 15
5000 525
4000 470
1000
45
1300 1450 2250 135
162 228 1000 1200 1800 120
150 200 300
250 450 15
12 28
"?
" ก
(1!!
"3 (1!!
"3 (1!!
"3
;&8
&" "$
:!\ !&4
ก!1!"34
18 .. 2550 Concept description 16
ก
&*3" :ก2"ก (&>! ' ;!)
&<!" ! 4>'4:&&8! "$
5$4&88"&34>(3"4>'4 ก &*$&ก !3" ก(1
<! 5: >'4>!3 ;!ก34"
2"ก ก(18ก34"*2"ก!4"""ก
1 &1& %3" ก(1 42"ก(กก!4"
&ก ! ((ก &>! ' ;!
ก &*$&ก !3" ก(1
18 .. 2550 Concept description 17
3 ;!"! 5
34" (Data Collection)
&1!*&8'82"ก 5ก>*4"8>!
>'4ก&1! information gain 2"* &ก !
&*$*&ก ! Relevant Analysis
&ก !
Attribute-oriented induction
2"ก&ก !(ก ก(14(ก AOI >'4" ('8! drilling, slicing) ก ก(12"ก
3 ;!"!ก &*$&ก !3" ก(1
18 .. 2550 Concept description 18
&ก ! <!&8&1!(ก34">! ก(1 &84
"ก&1& %3" ก(1 ก8ก ;34"
&ก !>'4
Information gain
Gain ratio
Gini index
χ2 contingency table statistics
"2! E
&ก !
18 .. 2550 Concept description 19
4!4ก !>( (Decision tree) ก"4
("#>!!ก" ก(12"ก
ก !&8<!4(กก" ก(1
>! 5$3"ก8F* = ก(1&
:4ก ก(1<! Categorical >'43 ;!"! 5 ID3
>'4ก834">'44 train 34""&:ก4" test >'4&8 information gain (ID3) 3"ก ก(1*2""8 ก 4!4ก !>(48&&=กกก ! ! ;!(!1>'4
ก 34"8&*6!48! ก (Overfitting problem)
ก>'4G934"1* &ก !
18 .. 2550 Concept description 20
?3" ก(1 = {Outlook, Temperature, Humidity, Wind}
Outlook
Humidity Wind
sunny overcast rain
yes
no yes
high normal
no
strong weak
yes
ก(1F* PlayTennis = {yes, no}
"84!4ก !>(
18 .. 2550 Concept description 21
ก1*!?3"34" S ?=8<! m ?8"&83"& ci i = {1,
…, m} 8?8"' ก si ! &83"34"&&2"
"6!73" ก(1 A &88ก ! a1,a2,…,av 8""ก<!?
8ก ;!&8 aj 8?(34"?8"&83"& ci (1!! sij
&8ก!34"4(ก ก(1 A &1!4
InfoGain(S, A) = H(S) – H(S | A)
"6!7&8ก!
HS=
∑
i=1 m si
Slog2si S
HS∣A=
∑
j=1
v s1j⋯sm j
S Is1 j,, sm j
18 .. 2550 Concept description 22
&8" 8!ก! <! &ก !3" ก(1"ก#*!=>'4
* กก&1!&4ก &8ก! 8(ก ก&83"34">! ก (1!>(
&8" 8!ก! ก(1 A &1!4(ก
&ก1 " <! &ก !>'4: &ก1 "&F*
4"ก
&8" 8!ก!&ก1 "
GainRatioS , A=HSHS∣A
HA
18 .. 2550 Classification: Decision tree 23
ก1*!?3"34" S ;* n &, &8'!(! gini !
2" pj &2"&8&: 5$3"& j >! S
(? S 8 ก(1 A ""ก<!&88ก ! a1,a2,…,
av 8""ก<!?8ก ;! Aj 1 ?(34"?8"&8 3"& ci (1!! sij
'!(!6ก(:ก2"ก>'4 giniS=1
∑
j=1 n
p2j
&8'!(! (Gini index)
GiniIndexS∣A=
∑
j=1
v s1j⋯sm j
S giniAj
18 .. 2550 Concept description 24
(*&1"5 ก3"! H =ก ;!ก'
ก1*!
ก(1name, gender, major, gpa birth_place, birth_date
phone#
Gen(ai) =ก"&& ' ;!3" ก(1 ai
Ui =&8ก8ก !ก>! ก(1 ai
Ti =&8&&(1!!ก9""ก3" ก(1 ai
R = 3"3&8&ก ! ("$?6!$3"(1!! ก(1 ก9>! 5$)
($ "8ก1!3" AOI
18 .. 2550 Concept description 25
1. 3 ;!34": กก8F* (! H =ก) ก ก8 (! %%)
2. 3 ;!ก &*$*
1. ก1( ก(18*ก ก &*$: ก1( namephone#
&834"ก8ก !ก (>'4 Ui)
2. !&834">*4ก43=;! ( "8 ' ;!3=;!): !&83"
major, birth_place, birth_date gpa กcount (>'4 Ti)
3. !4!ก"5 ก(1*2": gender, major, birth_country, age_rangegpa (>'4 R)
ก!ก I
18 .. 2550 Concept description 26
gender major birth_country age_range gpa count M Science Canada 20-25 Very_good 16 F Science Foreign 25-30 Excellent 22 M Engineering Foreign 25-30 Excellent 18 F Science Foreign 25-30 Excellent 25 M Science Canada 20-25 Excellent 21 F Engineering Canada 20-25 Excellent 18
Candidate relation for Target class: Graduate students (ΣΣΣΣ=120) gender major birth_country age_range gpa count M Science Foreign <20 Very_good 18
F Business Canada <20 Fair 20
M Business Canada <20 Fair 22
F Science Canada 20-25 Fair 24
M Engineering Foreign 20-25 Very_good 22 F Engineering Canada <20 Excellent 24 Candidate relation for Contrasting class: Undergraduate students (ΣΣΣΣ=130)
4(กก!ก I
18 .. 2550 Concept description 27
ก &*$&ก ! (Relevant analysis)
&1!&8&&!3"information gain >'4>!ก8
&1!"6!73" ก(1: major
(1!!! H >!
IScience”
(1!!! %%
>!IScience”
ก!ก II
1* major=“Science”:
1* major=“Engineering”:
1* major=“Business”:
s11= 84 s21= 42 I(s11, s21) = 0.9183 s12= 36 s22= 46 I(s12, s22) = 0.9892 s13= 0 s23= 42 I(s13, s23) = 0
Is1,s2=I120, 130=120
250log2120 250130
250log2130
250=0.9988
18 .. 2550 Concept description 28
&1!&8&&!3" information &
&1!&8ก!34"3" major
Gain(major) = I(s1, s2) – E(major) = 0.2115 &8ก!34"3" ก(1*2"
5$(กก!ก II
Gain(gender) = 0.0003
Gain(major) = 0.2115
Gain(birth_country) = 0.0407
Gain(gpa) = 0.4490
Gain(age_range) = 0.5971 Emajor=126
250Is1 1, s21 82
250Is1 2, s2 2 42
250Is1 3, s2 3=0.7873
18 .. 2550 Concept description 29
4 Initial working relation (W0) ก1*!R = 0.1
ก1( ก(18ก34" (genderbirth_country)
8!1"&>'4>!ก4relation
>'4 attribute-oriented induction! W04"&8Ti
major age_range gpa count
Science 20-25 Very_good 16 Science 25-30 Excellent 47 Science 20-25 Excellent 21 Engineering 20-25 Excellent 18 Engineering 25-30 Excellent 18
Initial target class working relation W0: Graduate students
"8ก1*2"34""5
18 .. 2550 Concept description 30
ก ก(*8&>! ก !
3 ;!"! 5:
8ก ;!?34"&83"&F* &
2"ก ' ;!>!8!3"&F**2"& >*4 ' ;!3"&"ก&4
!1!" 5$ 4&1"5 3" ก(14" " &2"
support – กก(3"&2"ก ;*
comparison – กก(3"&2"ก &"2!
!4! 5$>*4&8 ก8(ก&8"2! E
ก1*2"34"&ก8*8&
18 .. 2550 Concept description 31
ก1*!
ก(1 name, gender, major, birth_place, birth_date, residence, phone# gpa
Gen(ai) = ก"&& ' ;!3" ก(1 ai
Ui =&8ก8ก !ก>! ก(1 ai
Ti = &8&&(1!!ก9""ก3" ก(1 ai
R = 3"3&8&ก !3" 5$
"8ก1*2"34"
18 .. 2550 Concept description 32
1. ก634"8&
8<!34">!ก8F* 34">!ก8 2. &*$&ก !3" ก(1
ก1( ก(1 name, gender, major, phone#
3. !>*4"8>! 3" ;"&
4>'4ก1*!3"33"(1!! 4"ก
5$3" ;&F* &>! ก
& !5$*2"*ก (relations/cuboids)
ก!ก I ก &*$ก
18 .. 2550 Concept description 33
Birth_country Age_range Gpa Count%
Canada 20-25 Good 5.53%
Canada 25-30 Good 2.32%
Canada Over_30 Very_good 5.86%
… … … …
Other Over_30 Excellent 4.68%
Prime generalized relation for the target class: Graduate students Birth_country Age_range Gpa Count%
Canada 15-20 Fair 5.53%
Canada 15-20 Good 4.53%
… … … …
Canada 25-30 Good 5.02%
… … … …
Other Over_30 Excellent 0.68%
Prime generalized relation for the contrasting class: Undergraduate students
(กก!ก I
18 .. 2550 Concept description 34
>*4 A ! ก(14"ก' Ai &2"34"3"ก8 i >! ก(14"ก
t-weight &8>!'8 [0, 1] ! &2"
ก9 ก' (quantitative characteristic)
∀x, target_class(x) ⇒ condition(A1) [t:t_weight] ∨ ... ∨ condition(An) [t:t_weight]
ก9 ก'
tweight= countAi
∑
i=1 ncountAi
18 .. 2550 Concept description 35
>*4 Cj !ก8F*
qa &2"34" >*4"8>! &ก8F*
"(&"&34"8!3"ก8
d-weight &8>!'8 [0, 1] ! &2"
ก9&ก8' (quantitative discriminant)
∀x, target_class(x) ⇐ condition(x) [d:d_weight]
ก9&ก8'
dweight= countqa∈Cj
∑
i=1 mcountqa∈Ci
18 .. 2550 Concept description 36
ก9&ก8' (Quantitative discriminant rules)&2"
∀x, graduate_student(x) ⇐ birth_country(x) = “Canada” ∧ age_range(x) = “25-30” ∧ gpa(x) = “good” [d:30%]
90/(90+210) = 30%
Status Birth_country Age_range Gpa Count Graduate Canada 25-30 Good 90 Undergraduate Canada 25-30 Good 210
! กก(*8! H =กก ! %% H
"8ก9&ก8'
18 .. 2550 Concept description 37
ก9 ก' (Quantitative characteristic rules)
∀x, target(x) ⇒ condition(x) [t:t_weight]
(1<! (necessary) ก!34""8>!& ก8 ก9&ก8' (Quantitative discriminant rules)
∀x, target(x) ⇐ condition(x) [d:d_weight]
" (sufficient) :434" 4(1!!! ก8& 8!
8>1* &!>(
ก9"5 ' (Quantitative description)
∀x, target(x) ⇔ condition1(x) [t:w1, d:v1] ∨ ... ∨conditionn(x) [t:wn, d:vn] (1<!"(necessary and sufficient)
ก91* "5 &
18 .. 2550 Concept description 38
ก9"5 ' 1* ก8F* Europe
∀x, Europe(x) ⇔ (item(x) = “TV”) [t:25%, d:40%] ∨ (item(x) =
“computer”) [t:75%, d:30%]
Location/item TV Computer Both_items
Count t-wt d-wt Count t-wt d-wt Count t-wt d-wt
Europe 80 25% 40% 240 75% 30% 320 100% 32%
N_Am 120 17.65% 60% 560 82.35% 70% 680 100% 68%
Both_
regions
200 20% 100% 800 80% 100% 1000 100% 100%
34&8 t-weight, d-weight ก (*!8<! !) 3"&" "$
"8ก9"5 '
18 .. 2550 Concept description 39
1: :=:ก!1>'4>!ก1*2"34"
: <!$=กกก 34" "5 34">! ก8 E '8!
ก"5 4 !34" กก(34"<!4!
5ก"กกก(34" '8! &8 5A! (median), &8 (max), &81
(min), &"$$ (quartiles), &! (variance) (4"<!(1!!2">'4&1!4
&*$กก(34" >'4 boxplot*2"quantile analysis ก &*$กก(! ก! <!(1!! >'4boxplot
*2"quantile analysis
ก1*2"34"4 5:
18 .. 2550 Concept description 40
&83& (Mean)
&83& :8!;1*! ก 5A! (Median)
&8ก=ก34":4(1!!34"<!&*2"&83"&8ก"&8:4 (1!!34"<!&8
A!! (Mode)
&834"ก98"
mean – mode ≈ 3 ×(mean - median)
&8ก
x=
∑
i=1 n
xi
n
x=
∑
i=1 nwixi
∑
i=1 nwi
18 .. 2550 Concept description 41
กกก(""ก<!8!>'4*4&8:
&81(Q0), Q1, 5A! (Median), Q3,&8 (Q4) กกJก8" Boxplot
'34":ก!4ก8"
(3"ก8"&2" &"$$ก&"$$
&3"ก8"&2"IQR (Interquartile range) 5A!&2"4!>!ก8"
32!""ก(Whiskers) '2" &81&88ก ! 1.5 IQR
ก &*$>'4 boxplot
18 .. 2550 Concept description 42
"8 boxplot
Whisker
Median 25%
25%
Q3
Q1
18 .. 2550 Concept description 43
กJ3" boxplot >!
18 .. 2550 Concept description 44
&!3" "8
8!!A!: ก"<!ก3"&!
กก("&83&
<!!$ ก68"2"34"&8*2"!ก !*
'& (algebraic property)
กก(
s2= 1
n1
∑
i=1 n
xix2= 1 n1
∑i=1
n
xi21 n
∑
i=1 n
xi2
18 .. 2550 Concept description 45
ก &*$>'4Kก
กJ8กก(3"*!= ก(1 & = &:
18 .. 2550 Concept description 46
กJ&"!$ (Quantile plot)
กJ&"!$ กก(3"34" ;* 34"ก !
!4"ก8*2"8ก xi
18 .. 2550 Concept description 47
Quantile-Quantile (Q-Q) plot
กJ&"!$-&"!$ *2" Normal quantile plot :=กก (34"2"ก ก(ก(ก
18 .. 2550 Concept description 48
กJ3"" (Scatter plot)
กJ3"" (Scatter plot/Bivariate plot) (34">'4
" ก1*!>!8ก! := กกกก8ก!
3"34"3" *!=ก *2"
18 .. 2550 Concept description 49
ก1*2"34""5 (Mining concept description) &2"ก
&4!*&1"5 3"ก834" "( ก 3" ก (1*2"กก ก8ก8ก !
5ก4?=&1"5
OLAP-based
attribute-oriented induction
ก &*$&ก !'8>!ก2"ก ก(11& %>!ก"5 !"ก(ก!;: :ก!1>'4ก1*2"34""5
18 .. 2550 Concept description 50
Y. Cai, N. Cercone, and J. Han. Attribute-oriented induction in relational databases. In G.
Piatetsky-Shapiro and W. J. Frawley, editors, Knowledge Discovery in Databases, pages 213-228. AAAI/MIT Press, 1991.
S. Chaudhuri and U. Dayal. An overview of data warehousing and OLAP technology. ACM SIGMOD Record, 26:65-74, 1997
C. Carter and H. Hamilton. Efficient attribute-oriented generalization for knowledge discovery from large databases. IEEE Trans. Knowledge and Data Engineering, 10:193-208, 1998.
W. Cleveland. Visualizing Data. Hobart Press, Summit NJ, 1993.
J. L. Devore. Probability and Statistics for Engineering and the Science, 4th ed. Duxbury Press, 1995.
T. G. Dietterich and R. S. Michalski. A comparative review of selected methods for learning from examples. In Michalski et al., editor, Machine Learning: An Artificial Intelligence Approach, Vol. 1, pages 41-82. Morgan Kaufmann, 1983.
J. Gray, S. Chaudhuri, A. Bosworth, A. Layman, D. Reichart, M. Venkatrao, F. Pellow, and H. Pirahesh. Data cube: A relational aggregation operator generalizing group-by, cross-tab and sub-totals. Data Mining and Knowledge Discovery, 1:29-54, 1997.
J. Han, Y. Cai, and N. Cercone. Data-driven discovery of quantitative rules in relational databases. IEEE Trans. Knowledge and Data Engineering, 5:29-40, 1993.
"ก"4" L
18 .. 2550 Concept description 51
J. Han and Y. Fu. Exploration of the power of attribute-oriented induction in data mining.
In U.M. Fayyad, G. Piatetsky-Shapiro, P. Smyth, and R. Uthurusamy, editors, Advances in Knowledge Discovery and Data Mining, pages 399-421. AAAI/MIT Press, 1996.
R. A. Johnson and D. A. Wichern. Applied Multivariate Statistical Analysis, 3rd ed.
Prentice Hall, 1992.
E. Knorr and R. Ng. Algorithms for mining distance-based outliers in large datasets.
VLDB'98, New York, NY, Aug. 1998.
H. Liu and H. Motoda. Feature Selection for Knowledge Discovery and Data Mining.
Kluwer Academic Publishers, 1998.
R. S. Michalski. A theory and methodology of inductive learning. In Michalski et al., editor, Machine Learning: An Artificial Intelligence Approach, Vol. 1, Morgan Kaufmann, 1983.
T. M. Mitchell. Version spaces: A candidate elimination approach to rule learning.
IJCAI'97, Cambridge, MA.
T. M. Mitchell. Generalization as search. Artificial Intelligence, 18:203-226, 1982.
T. M. Mitchell. Machine Learning. McGraw Hill, 1997.
J. R. Quinlan. Induction of decision trees. Machine Learning, 1:81-106, 1986.
D. Subramanian and J. Feigenbaum. Factorization in experiment generation. AAAI'86, Philadelphia, PA, Aug. 1986.
"ก"4" M