Int
ern
at
i
onal
Journ
al of Ele
ctrical
an
d
Co
mput
er
En
gin
eeri
ng
(IJ
E
C
E)
Vo
l.
10
,
No.
5
,
Octo
be
r
2020
,
pp.
4892
~
4899
IS
S
N:
20
88
-
8708
,
DOI: 10
.11
591/
ijece
.
v
10
i
5
.
pp
4892
-
48
99
4892
Journ
al h
om
e
page
:
http:
//
ij
ece.i
aesc
or
e.c
om/i
nd
ex
.ph
p/IJ
ECE
A new p
erspe
ctive of
refractiv
e e
rror
c
alcul
atio
n
w
ith
mo
bil
e a
pp
lication
Ko
m
ang
C
andra Br
ata,
M
ukh
amm
ad
S
ha
ri
f
Hid
ayatull
oh
, L
utfi F
anani
,
Adam
Hendr
a
Br
ata
Multi
m
edi
a
,
Ga
m
e
and
Mobil
e Te
chno
log
y
Res
ea
rch
Group
,
De
par
tment
of
Co
m
pute
r
Scie
n
ce,
Brawij
a
y
a
Univ
e
rsit
y
,
Indon
esia
Art
ic
le
In
f
o
ABSTR
A
CT
Art
ic
le
history:
Re
cei
ved
N
ov
20
, 201
9
Re
vised
Ma
r
9
,
2020
Accepte
d
Ma
r
25
, 202
0
In
m
an
y
si
tua
t
io
ns,
not
stand
ard
i
ze
d
and
li
m
ited
ac
c
ess
to
e
y
e
he
al
th
ca
r
e
i
n
seve
ral
reg
ions
of
Indone
sia
becom
es
the
m
ai
n
cha
llenge
for
m
y
opia
pat
i
ent
s
to
m
ea
sure
and
m
onit
or
the
ir
cu
rre
nt
ref
r
active
err
or
condition
.
Man
y
apps
were
proposed
t
o
provide
l
ow
-
c
ost
al
te
rn
at
iv
e
m
ea
surem
ent
tool
s
rat
her
th
an
expe
nsive
tool
s
such
as
Phoropter
with
Snel
le
n
cha
rt
and
Re
ti
n
oscop
y
,
bu
t
stil
l,
those
apps
nee
d
an
Int
ern
e
t
conne
ction
and
m
anua
lly
complex
steps
to
oper
ate.
Th
ese
c
ondit
ions
m
ake
m
y
op
ia
patien
ts
rel
uc
ta
nt
to
use
t
his
kind
of
servic
e
.
In this r
ega
rd, we
propo
se
an
in
tui
t
ive
d
i
opte
r
l
evel
m
ea
s
ure
m
ent
app
base
d
on
m
obil
e
appl
icati
on
setu
p,
which
implements
the
concept
of
m
ea
sure
the
user
fa
ce
to
sm
art
phone
scre
en
dista
nc
e
for
t
he
rap
id
diop
te
r
ca
l
cul
a
ti
on
pro
ce
ss
es
and
a
t
the
sam
e
ti
m
e
provide
s
a
low
-
cost
alter
n
at
iv
e
ref
ra
ct
iv
e
m
ea
surem
ent
to
ol.
Th
is
pap
er
h
ighl
ight
s
our
ex
per
ie
n
ce
s
when
deve
lop
ing
a
m
obil
e
appl
i
cation
tha
t
ca
n
he
l
p
pat
ie
n
ts
with
m
y
op
ia
m
ea
suri
ng
the
ir
blur
li
ne
dista
n
ce
s
a
nd
eva
luate
thei
r
di
opte
r
l
ev
el
s
inde
pend
ent
l
y
.
W
e
conduc
t
a
num
ber
of
hu
m
an
tri
a
ls
with
the
dev
ice
on
a
cont
rol
le
d
environm
ent
to
demons
tra
te
th
e
abi
l
ity
of
the
proposed
app
to
m
ea
sure
the
d
i
opte
r
l
eve
l
.
The
expe
r
iment
al
result
s
show
tha
t
the
propose
d
app
is
quit
e
succ
essfu
l
in
m
ea
suring
the
di
opte
r
le
v
el
of
m
y
opi
a
patien
ts
with
a
re
lativel
y
sm
al
l
ran
ge
of
calc
ul
ation
e
r
rors c
om
par
ed to
optometri
st
m
eas
ure
m
ent
result
s
.
Ke
yw
or
d
s
:
Diopte
r
E
ye
h
eal
th
Mob
il
e a
pp
li
ca
ti
on
My
op
ia
Re
fr
act
ive m
easur
em
ent
Copyright
©
202
0
Instit
ut
e
o
f Ad
vanc
ed
Engi
n
ee
r
ing
and
S
cienc
e
.
Al
l
rights re
serv
ed
.
Corres
pond
in
g
Aut
h
or
:
Ko
m
ang
Ca
ndr
a Brata
,
Dep
a
rtm
ent o
f C
om
pu
te
r
Scie
nce,
Un
i
ver
sit
as B
r
awijaya,
Vetera
n
St.
, N
o.
8, Ma
la
ng
6514
5,
East
Ja
va
, In
donesia.
Em
a
il
:
k.
candr
a.brat
a@ub.
ac.
id
1.
INTROD
U
CTION
Visu
al
im
pairm
ent
ref
e
rs
t
o
a
treat
able/
m
anag
ea
ble
sta
t
e
m
ark
ed
by
reduce
d
visio
n
or
siz
e
of
the
visu
al
fiel
d
by
one
per
s
on.
Re
fr
act
i
ve
disorde
r
is
one
of
m
any
fo
rm
s
of
visu
al
i
m
pair
m
ent
wh
ic
h
is
a
le
adin
g
cau
s
e
of
vis
ual
dis
abili
ty
thro
ug
hout
th
e
w
or
l
d.
Re
fr
act
ive
e
rro
rs
are
t
he
ina
bi
li
t
ie
s
of
the
e
ye
s
to
fo
c
us
on
t
he
visu
al
im
ages
from
the
outsi
de
e
nviro
nm
e
nt,
wh
ic
h
res
ul
ts
in
seri
ous
visu
al
im
pairm
ent
in
sever
e
cases
,
blurre
d
visio
n
or
eve
n
blin
dn
e
ss
[1
]
.
T
he
My
op
ia
(N
e
arsig
hted
ness
),
a
co
m
m
on
fo
rm
of
refract
ive
e
rro
r
ca
us
es
visio
n
im
pair
m
ent
no
t
only
by
di
rect
reti
nal
da
m
age
[
2]
but
al
so
by
i
ncr
e
asi
ng
the
ris
ks
f
or
c
at
aract
[3
]
a
nd
the
onset
of
glauc
om
a
[4
]
.
F
o
r
m
y
o
p
i
a
p
a
t
i
e
n
t
s
,
c
l
o
s
e
o
b
j
e
c
t
s
l
o
o
k
c
l
e
a
r
b
u
t
d
i
s
t
a
nt
o
b
j
e
c
t
s
a
p
p
e
a
r
b
l
u
r
r
e
d
b
e
c
a
u
s
e
t
h
e
l
i
g
h
t
i
s
b
e
i
n
g
f
o
c
u
s
e
d
i
n
f
r
o
n
t
o
f
i
n
s
t
e
a
d
o
f
o
n
t
h
e
r
e
t
i
n
a
o
f
t
h
e
e
y
e
[
5
]
.
The
gl
ob
al
pre
valence
of
m
yo
pia
is
ex
pect
ed
to
incre
ase
fr
om
27
%
of
the
world
’s
popula
ti
on
i
n
201
0
to
52%
by
20
50
[
6].
I
n
the
c
on
te
xt
of
I
ndonesi
a
a
s
the
la
rg
est
a
rch
i
pelagic
c
ount
ry
in
t
he
world
,
diff
ic
ulty
to
ac
cess
ey
e
healt
h
serv
ic
e
is
al
so
encoun
te
red
i
n
seve
ral
isl
and
reg
i
ons
an
d
vill
ages
in
Ind
on
e
sia
.
In
I
ndonesi
a,
t
he
reg
i
ons
a
re classi
fied
in
t
o
t
hr
ee
ty
pes,
ba
s
ed
on
the
di
ff
ic
ulty
of
acce
ss
to
ey
e h
eal
th
se
rv
ic
e,
nam
ely
non
-
re
m
ote,
re
m
ote
and
isl
a
nd
cl
ust
ers.
Non
-
rem
ote
re
gions
are
tho
se
w
hich
ha
ve
relat
ively
easi
ly
acce
ssible
heal
th
serv
ic
e
a
nd
hav
e
s
uffici
ent
hu
m
an
resource
s
and
in
fr
a
struct
u
re.
Re
m
ote
reg
io
ns
are
usual
ly
Evaluation Warning : The document was created with Spire.PDF for Python.
In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
-
8708
A n
ew
pers
pect
iv
e o
f ref
ra
ct
iv
e erro
r
c
alculat
ion
wi
th
m
ob
il
e app
li
cati
on
(
Komang C
andra Br
at
a)
4893
tho
se
w
hich
ha
ve
healt
h
se
r
vices
that
a
re
m
or
e
diff
ic
ult
to
acce
ss
a
nd
hav
e
lim
it
ed
hum
an
resou
rce
s
an
d
infr
a
struct
ur
e
. I
sla
nd cluster regio
ns
are
rem
ote r
egi
on
s tha
t hav
e the m
os
t
d
ifficult
ie
s to
acce
ss h
eal
th s
erv
ic
e
and
ha
ve
very
lim
it
ed
or
even
non
-
exis
te
nt
hu
m
an
resour
ces
a
nd
infr
a
struct
ur
e
.
The
la
te
st
data
on
the
prevale
nce
of
visu
al
im
pairm
ent
in
Indonesia
is
obt
ai
ned
th
r
ough
a
su
r
vey
on
“R
oad
m
ap
of
Visu
al
Im
pair
m
ent
Con
tr
ol
Program
in
I
ndonesi
a
2017
-
20
30
”
w
hich
s
hows
that
t
he
pre
valence
of
visu
al
im
pairm
ent
in
I
ndonesi
a
c
on
ti
nues
t
o
be
high.
T
o
overc
om
e
visu
a
l
i
m
pairm
ent
in
Indonesia,
va
rio
us
ef
f
or
ts
a
re
need
e
d
includi
ng
pro
m
ot
ive,
pr
e
ve
nt
at
ive,
cur
at
ive
and
re
hab
il
it
at
ive
act
ion
.
O
ne
of
the
key
act
ivit
ie
s
in
the
progra
m
to
m
anag
e
vis
ual
im
pair
m
ent
is
to
en
sure
the
c
orrecte
d
visio
n
for
sc
hool
-
a
ge
d
c
hildr
e
n
a
nd
the
young
gen
e
rati
on
havi
ng
refract
io
n diso
rd
e
r
a
nd in
crease the
a
vaila
bili
ty
o
f
ey
e
healt
h
se
rv
ic
es
[7].
The
diopter
(
D
)
is
the u
nit
of m
easur
em
ent
fo
r
t
he
re
fr
act
iv
e
powe
r
of
a
le
ns
. U
nc
orrecte
d
m
yopia
as
low
as
–
1.50
D
will
resu
lt
i
n
m
od
erate
vision
im
pair
m
e
nt,
an
d
un
c
orr
ect
ed
m
yopia
m
or
e
than
–
4.00
D
is
su
f
fici
ent
re
fr
a
ct
ive
error
t
o
be
cl
assifi
ed
as
blindness
[
8].
The
pr
e
vaili
ng
treatm
ent
of
r
efr
act
ive
e
rrors
wh
ic
h
are co
m
m
on
ly
u
se
d
in
daily
li
fe ar
e
g
la
sses
a
nd contac
t l
ens
es [9]
. The co
m
m
on
m
e
tho
d
t
o
m
easur
e re
frac
ti
ve
error
Diopte
r
i
s
a
com
bin
at
ion
of
a
phoro
pt
er
with
a
Sn
el
l
en
cha
rt
[
10]
.
Phorop
te
r
co
nt
ai
ns
dif
fe
ren
t
l
enses
that
can
be
a
djust
ed
by
the
op
t
om
et
rist
to
get
patie
nt’s
e
dg
e
of
blur
[
11]
.
This
m
et
hod
can
giv
es
ac
cur
at
e
ou
tc
om
es,
bu
t
it
st
il
l
need
s
a
la
r
ge
platf
or
m
and
can
on
ly
be
op
e
ra
te
d
by
a
pro
f
essional
opto
m
et
rist.
This
proce
ss
al
so
require
s
vi
su
al
acuit
y
know
le
dg
e
from
the
patie
nt
as
well
.
Re
ti
no
s
cop
y
is
an
al
te
rn
at
iv
e
m
et
ho
d
of
m
ea
su
ri
ng
refract
ive
er
ror
w
hich
do
es
not
requi
re
pati
ents'
co
-
op
e
rati
on.
T
his
m
et
ho
d
us
es
a
too
l
cal
le
d
a reti
nos
cop
e
, but t
his e
xp
e
ns
i
ve
to
ol
ne
eds
t
he
e
xp
e
rt
ise
to op
e
rate [
12
]
.
The
em
erg
e
nc
e
of
sm
artphon
e
s
m
akes
these
ubiq
uito
us
de
vices
a
r
e
increa
sin
gly
com
plex,
com
pu
ta
ti
on
al
ly
powerfu
l,
a
nd
i
nteg
rated
wi
th
va
rio
us
s
ens
or
s.
A
sm
a
rtp
hone
ca
n
c
ollec
t
and
c
om
pu
te
var
i
ou
s
data,
pro
vid
in
g
opport
un
it
ie
s
to
i
m
pr
ov
e
qu
al
it
y
of
li
fe
in
a
way
that
not
easi
ly
achievable
wit
h
conve
ntion
al
a
ppr
oach
es
[
13
-
15
]
.
Re
cent
e
xam
ple
of
a
pp
li
cat
ion
w
hich
c
an
c
om
pu
te
th
e
di
op
te
r
dig
it
al
ly
are
evide
nce
that
this
te
chnolo
gy
is
feasible
as
portable
diag
no
sti
c
to
ols
th
at
of
fe
r
an
op
portu
nity
to
decr
ease
costs
an
d
inc
re
ase
the
avail
ab
il
ity
of
ey
e
hea
lt
hcar
e
f
or
a
ny
body,
bu
t
sti
ll
,
tho
se
a
pps
jus
t
dig
it
al
iz
e
a
reg
ula
r
fu
ll
exam
inati
on
p
r
ocesse
s
or
an
ad
vice
of
th
e
ophth
al
m
olo
gist
and
nee
d
m
anu
al
blur
li
ne
distance
inpu
t
fr
o
m
the
us
e
r
to
operate
.
I
n
ad
diti
on
,
from
the
us
er
’s
c
omm
e
nts
an
d
re
vie
ws,
the
la
c
k
of
us
e
r
ex
pe
rience
i
n
the af
or
em
entione
d
a
ppli
cat
ion
s m
akes m
yo
pia p
at
ie
nts r
el
ucta
nt to
use t
hi
s k
in
d of ser
vi
ce
[
16
-
19]
.
The
af
orem
ent
ion
e
d
pr
ob
le
m
s
pu
t
forw
a
r
d
for
co
ns
id
erati
on
t
hat
m
ob
il
e
app
li
cat
ions
m
igh
t
bri
ng
a
big
hel
p
f
or
m
yopia
patie
nts
to
m
easur
e
blu
r
li
ne
distance
an
d
re
cognize
m
yopia
bef
ore
visit
ing
an
ophth
al
m
olo
gi
st
or
oth
e
r
healt
h
ser
vices.
T
he
awar
e
ness
of
m
on
it
or
ing
th
e
ey
es'
healt
h
conditi
ons
is
the
key
to
preve
nt
the
m
yopia
case
from
getti
ng
worse.
In
t
his
pa
per,
we
e
xplor
e
ind
ivi
dual
re
sp
onses
ab
out
thei
r
awar
e
ness
of
e
ye
sigh
t
pro
blem
s.
Nex
t,
base
d
on
colle
ct
ed
res
po
nd
e
nt
dat
a,
we
de
velo
p
a
m
ob
il
e
app
li
cat
io
n
prototype
t
hat
cou
l
d
c
om
pu
te
the
re
fr
act
iv
e
error
le
vel
a
uto
m
at
ic
ally
t
o
in
vestigat
e
t
he
fea
sibil
it
y
of
t
his
appr
oach.
This
app
li
cat
ion
obvi
ously
of
fe
r
s
an
op
portu
nity
to
pr
ovide
a
si
m
ple,
low
-
cost
an
d
bette
r
u
se
r
exp
e
rience
al
t
ern
at
ive
m
easur
em
ent
too
l
t
hat
will
be
a
big
help
f
or
m
yopia
patie
nt
s
to
m
easur
in
g
their
refract
ive
disor
der
le
vel
(
f
or
ne
ar
-
si
gh
te
dn
es
s)
a
nd
com
pu
t
e
the
ey
eglasse
s
powe
r
(d
i
op
t
er)
.
I
nd
i
rectl
y,
it
will
increase
t
he
a
va
il
abili
ty
of
ey
e
car
egi
vers
to
any
m
yopia
pa
ti
ents
due
to
t
hey
can
i
ndep
end
e
ntly
m
on
ito
ri
ng
their ey
e c
ondi
ti
on
by only
us
ing
a
sm
artph
one.
2.
RESEA
R
CH MET
HO
D
In
t
his
sect
io
n,
we
pr
ese
nt
th
e
de
velo
pm
ent
process
of
ou
r
m
ini
m
u
m
vi
able
pro
duct
.
Con
si
der
i
ng
con
te
xtu
al
pro
blem
s,
w
e
have
fo
c
us
e
d
on
detect
ing
t
he
e
ye
power
of
m
yopes.
Dev
e
lop
in
g
a
uto
m
at
ic
and
intuit
ive
diopter
cal
culat
or
a
pp
s
f
or
m
yopia
has
ex
pa
nde
d
our
point
of
view
a
bout
vision
exam
inatio
n
a
nd
m
on
it
or
ing
syst
e
m
s,
bu
t
it
m
us
t
be
e
m
ph
asi
zed
t
hat
this
ne
w
a
ppr
oach
al
so
i
ntr
oduces
a
cha
ng
e
i
n
the
co
nventio
na
l
ey
e
m
easur
e
m
ent
m
et
ho
ds
w
hich
a
re
usi
ng
e
xpen
sive
too
ls
t
o
ope
r
at
e.
Buil
ding
an
ey
e
m
easur
em
ent
app
li
cat
io
n
is
not
sim
ply
a
matt
er
of
te
c
hn
i
cal
wizardry
.
This
is
due
to
the
fact
that
ca
lc
ulate
the
po
wer
of
a
le
ns
only
with
a
sm
artpho
ne
nee
ds
a
fa
nc
y
al
gorithm
.
Ad
diti
onal
ly
,
de
velo
p
a
n
a
pp
li
cat
ion
that
easy
to
use
by
the
us
er
i
s
al
so
m
at
te
rs.
The
ste
ps
f
or
requirem
ent
el
ic
it
at
ion
for
th
e
pro
po
se
d
i
ntu
it
ive
diopter cal
c
ulator, com
pu
ta
ti
onal
d
e
sig
n
al
go
rithm
an
d
syst
e
m
d
esi
gn
strate
gies are
d
isc
usse
d belo
w.
2.1.
Reco
r
ding
user re
quir
ements
In
this
pap
e
r,
a
diary
stud
y
was
us
e
d
to
e
xp
l
or
e
a
nd
ref
l
ect
on
the
re
sponde
nt'
s
resp
onses
to
thei
r
awar
e
ness
of
e
ye
sigh
t
pro
ble
m
s.
Then
,
bas
ed
on
insig
ht
f
ro
m
resp
on
dent
data,
we
buil
d
a
us
er
journ
ey
to
gathe
r
us
e
r
re
qu
i
rem
ents.
A
us
er
jo
urney
m
ap
is
a
rece
ntly
e
m
erg
ed
m
et
ho
d
to
gat
her
re
quirem
e
nts
an
d
desig
ning
t
he
us
er
ex
pe
rienc
e
in
t
he
a
ppli
cat
ion
pro
du
ct
.
T
his
m
ap
ad
ds
a
thir
d
di
m
ension
al
feat
ur
e
to
a
tradit
ion
al
use
r
pe
rs
on
a
by
fo
c
us
in
g
on
a
diach
ronic
ou
tl
ine
of
a
use
r
and
a
pro
du
ct
[20].
Re
cent
works
pro
ve
that
this
appr
oach
is
an
eff
ect
ive
too
l
for
rap
i
dly
gather
i
ng
use
r
sto
ries
in
order
to
dev
el
op
an
int
uiti
ve
app
li
cat
io
n
[
21
-
23]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
:
2088
-
8708
In
t J
Elec
&
C
om
p
En
g,
V
ol.
10
, No
.
5
,
Oct
ob
e
r
2020
:
48
92
-
48
99
4894
Ther
e
ca
n
be
a
dif
fer
e
nt
nu
m
ber
of
pa
rtic
i
pan
ts
act
ually
en
ga
ged
in
the
fiel
d
st
ud
y
an
d
te
sti
ng
.
Faulkne
r
sti
pu
l
at
es
that
20
res
pondents
will
rev
eal
as
m
any
us
a
bili
ty
pr
ob
l
e
m
s
as
m
or
e
pe
op
le
will
do
a
nd
it
is
su
f
fici
ent
to
offe
r
the
usa
bili
ty
exp
eri
m
entat
ion
a
r
easo
nab
le
value
-
to
-
c
os
t
bal
ance
[
24]
.
Ba
sed
on
Faulkne
r'
s
insigh
t,
20
res
pond
e
nts
we
re
involve
d
in
t
his
stud
y.
T
hey
li
ve
in
the
non
-
rem
ote
are
a
wer
e
the
healt
h
care
facil
it
ie
s
easy
to
acce
ss.
Th
ey
wer
e
at
le
ast
fa
m
il
ia
r
wit
h
A
ndr
oid
m
ob
il
e
app
li
cat
io
ns
with
m
ini
m
u
m
OS
ver
si
on
5
(L
olli
pop)
a
nd
good
in
En
glish.
T
hey
we
re
cat
eg
or
iz
e
d
by
pe
ople
with
no
rm
al
ey
es,
m
yopia
but
not
wea
r
glasse
s
an
d
m
yopia
with
glasses
.
Als
o,
ha
ve
ba
sic
knowle
dg
e
or
e
xp
e
rienc
e
with
m
easur
in
g
t
he
ir
cu
rr
e
nt
refr
act
ive
er
ror
a
nd
kn
ow
their
own
cu
rr
e
nt
diopter
le
vel
so
t
h
ey
can
c
onfirm
the correct
ness
of the
prop
os
e
d
a
pp
li
cat
io
n
r
esult i
n
t
he
te
st
ing
phase.
We
are
e
xam
in
ing
per
s
onal
re
sp
onses
t
o
thei
r
knowle
dge
a
bout
vis
ual
acu
it
y.
Du
rin
g
our
su
r
vey
an
d
intervie
w
phas
e,
we
as
ke
d
se
ver
al
key
ques
ti
on
s
a
bout
ho
w
oft
en
t
hey
vi
sit
pr
ofessi
on
al
op
t
om
et
rist
or
ey
e
care
ser
vices
and
how
they
ov
er
com
e
their
ey
e
pr
oble
m
s
in
daily
lif
e
.
Am
ong
al
l
these
par
ti
ci
pan
ts
,
m
os
t
of
them
sai
d
they
f
org
ot
ab
ou
t
t
heir
la
st
visit
to
a
do
ct
or
or
an
opht
halm
olo
gist
because
of
th
ei
r
ey
e
pro
blem
,
2
of
them
sai
d
they
visit
ed
rece
ntly
and
al
l
of
t
he
m
feel
hav
in
g
ey
e
pr
oble
m
s
bu
t
unwill
ing
t
o
we
nt
to the eye
doct
or.
Fr
om
our
st
ud
i
es,
we
ha
ve
f
ound
s
om
e
insig
hts
an
d
ba
rr
ie
r
s
to
ey
e
healt
h
and
visi
on
e
xa
m
inati
on
of
com
m
on
p
eo
pl
e, these
are:
-
They are
not
a
war
e
of thei
r
e
ye
p
r
oble
m
s.
-
They are
not
vi
sit
ing
eye
do
ct
or
s
or
opht
halm
olo
gist regul
arly
.
-
Cost an
d othe
r l
i
m
it
at
ion
s (
loc
at
ion
, dist
ance
,
tran
s
port,
lo
ng queu
e
in
ey
e
c
are,
et
c.
).
Ba
sed
on
thes
e
insigh
ts
fro
m
peo
ple
w
ho
li
ve
in
the
non
-
rem
ote
area,
in
o
ur
un
der
sta
nd
i
ng,
the
rem
ote
re
gio
n'
s
c
onditi
on
cou
l
d
pr
es
ent
m
or
e
diff
ic
ulti
es.
T
o
overc
om
e
these
di
ff
ic
ulti
es,
we
pr
opos
e
d
a
n
intuit
ive
and
l
ow
c
os
t
al
te
rnat
ive
ref
racti
ve
err
or
m
easur
ing
to
ol
that
can
be
us
e
d
in
de
pende
ntly
by
a
us
er
on
ly
with a
sm
artp
h
one.
2.2.
S
ystem d
esi
gn
Since
we
a
re
dev
el
op
i
ng
a
m
ob
il
e
app
t
o
overc
om
e
the
af
or
e
m
entione
d
pro
blem
s,
we
pro
po
s
e
d
a
li
gh
twei
ght
arch
it
ect
ure
ap
plica
ti
on
de
sig
n
w
hich
has
a
no
te
worthy
fe
at
ur
e
to
disp
la
y
a
dio
pter
le
vel
to
the
use
r
acc
ura
te
ly
and
int
uiti
vely
.
T
his
ap
pl
ic
at
ion
ne
eds
to
c
onve
rt
the
r
aw
data
(t
he
distance
of
us
e
r
ey
es
and
sm
artpho
ne
screen
)
int
o
the
di
op
te
r
val
ue
.
This
a
pp
li
ca
ti
on
use
s
a
f
ront
face
cam
era
to
captu
re
real
-
tim
e
i
m
ager
y
from
t
he
us
er
faces
t
hen
aut
om
atic
al
ly
determ
ine
the
ey
e
p
os
it
io
n
to
determ
ine
the
distance
of
bl
ur
li
ne.
Nex
t,
with
the
distance
data,
the
ap
plica
ti
on
com
pu
te
s
the
dio
pte
r
le
ve
l
and
show
s
the
res
ult
to
the
us
er.
Tech
nical
ly
,
w
e
sepa
rate
the
m
od
ule
of
th
e
pro
po
se
d
a
pp
i
n
th
ree
la
ye
r
s,
hard
war
e
la
ye
r,
face
detect
i
on
la
ye
r,
and
a
ppli
cat
ion
la
ye
r.
The
ha
rdwar
e
la
ye
r
i
nvokes
the
sm
artp
hones'
hardw
a
re
init
ia
ti
on
,
w
hic
h
has
t
he
m
ai
n
functi
on
to
init
ia
te
the
fr
ont
ca
m
era
and
ac
cel
ero
m
et
er
con
tr
ol
to
be
us
e
d
as
input
para
m
et
ers.
The
second
la
ye
r
is
the
face
detect
ion
la
ye
r
wh
ic
h
r
ecognize
s
use
r
face
an
d
ey
e
trackin
g
f
rom
real
-
tim
e
i
m
ager
y.
This
la
ye
r
is
m
ade
by
integ
rati
ng
t
he
G
oo
gle
m
ob
il
e
Vision
API
[
25]
in
our
offli
ne
m
od
ule
s
o
th
is
app
te
chn
ic
al
ly
doesn’
t
ne
ed
a
n
In
te
r
net
co
nnect
ion
.
T
his
AP
I
pro
vid
es
an
inter
face
to
detect
the
le
ft
ey
e,
rig
ht
ey
e,
an
d
no
s
e
as
a
po
i
nt
of
i
nterest
wit
hin
a
face.
T
he
n
ba
sed
on
the
distance
that
w
e
ob
ta
i
ned
fro
m
this
process
,
the
a
pp
li
cat
io
n
la
ye
r
will
cal
culat
e
the
diopter
us
in
g
a
f
orm
ula
in
[26]
a
nd
dis
play
the
re
su
lt
to
the user.
T
he
c
om
plete
p
ro
ce
s
s f
lo
w
is
sho
w
n
in
Fig
ure
1.
Figure
1.
Syst
em
m
od
ule o
f
th
e pro
posed
app
li
cat
ion
Evaluation Warning : The document was created with Spire.PDF for Python.
In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
-
8708
A n
ew
pers
pect
iv
e o
f ref
ra
ct
iv
e erro
r
c
alculat
ion
wi
th
m
ob
il
e app
li
cati
on
(
Komang C
andra Br
at
a)
4895
2.3.
Ca
m
era
ba
sed
eye
to
s
martph
on
e s
c
reen dist
an
ce
measure
ment
The
dista
nce
c
al
culat
ion
of
th
e
us
er'
s
face
to
a
s
m
artph
one
screen
a
ppr
oac
h
bri
ngs
m
any
ben
e
fits
for
m
ob
il
e
-
based
util
it
y
app
li
cat
ion
s
.
Ma
ny
m
et
hods
ha
ve
de
velo
ped
to
ca
lc
ul
at
e
the
distance
betwee
n
ey
e
to
a
sm
artph
one
from
us
ing
Inf
rar
e
d
cam
era
[
27
]
,
t
he
c
om
bi
nation
of
ste
re
o
cam
era
and
infr
a
re
d
[
28]
,
un
ti
l
us
in
g
vi
deo
of
a
m
on
oc
ular
c
a
m
era
[29].
A
m
on
g
al
l
pr
op
os
e
d
al
gorithm
s,
in
20
14,
K
onig
et
al
pro
posed
a
n
al
gorithm
to
m
easur
e
t
he
s
creen
to
face
distance
base
d
on
t
he
base
le
ng
th
data
be
tween
tw
o
ey
es
in
a
ref
ere
nce
distance
(kn
own
as
interp
upil
la
ry
distance)
only
us
in
g
a
sm
artphon
e
bu
i
ld
-
i
n
se
nsor
a
nd
fron
t
ca
m
era.
This
Scree
n
to
face
distance
cal
culat
ion
s
out
put
in
centim
e
ter
distance
[
30]
.
Ther
ef
ore,
Konig’
s
m
et
ho
d
sta
nds
ou
t
from
othe
r
ap
proac
hes
by
pro
vi
ding
a
real
-
ti
m
e
distance
cal
cula
ti
on
a
nd
giv
e
natu
ra
l
visu
al
ex
pe
rience
in
the
wa
y
of
interact
i
on
with
the
s
m
artphon
e
.
T
he
us
a
ge
of
t
he
K
on
i
g’s
propose
d
app
li
cat
io
n
a
nd for
m
ula to c
om
pu
te
eye
s and sm
artphon
e
s
creen
d
ist
an
ce
(f) is
dep
ic
te
d i
n
Fi
gure
2.
Figure
2
.
The
desig
n of ey
e
-
s
creen
m
easur
em
ent scenar
i
o and f
or
m
ula to c
om
pu
te
the
di
sta
nce
Her
e
,
f
or
(
dsf
)
c
orres
pond
s
to
t
he
sc
ree
n
to
face
distan
ce
[cm
]
and
dre
f
to
t
he
i
nter
pupill
ary
dista
nce
of
the
re
fer
e
nce
pi
ct
ur
e
[cm
]
,
ps
f
de
no
te
s
ey
e
to
ey
e
distance
on
the
act
ual
picture
[p
i
xel]
an
d
pr
ef
c
orres
pond
s
to
the
ey
e
to
ey
e
distance
on
the
ref
e
ren
c
e
picture
[p
i
xe
l]
.
This
desig
n
and
f
or
m
ula
on
ly
ef
fecti
ve
wh
e
n
the v
ie
w
a
ng
le
is 9
0 degrees
from
the sm
artph
one
scree
n.
2.4.
Co
m
pu
t
e
le
nses p
ower
We
us
e
d
the
di
sta
nce
of
eac
h
ey
e’s
bl
ur
li
ne
as
the
distance
par
am
et
er.
Bl
ur
li
ne
is
t
he
dis
ta
nce
f
ro
m
an
ey
e
in
the
read
in
g
posit
io
n
unti
l
the
te
xt
app
ea
rs
blurr
y
to
a
per
son
[
31
]
.
T
he
diopt
er
value
is
ge
ne
rated
from
each
ey
e
on
eac
h
m
easur
em
ent
occasi
on
acc
ordi
ng
t
o
Al
go
rithm
1.
Konig
al
gorithm
on
ly
eff
ect
ive
to
m
easur
e
the
di
sta
nce
f
ro
m
19
centi
m
e
te
rs
to
89
ce
nti
m
et
ers,
this
m
eans,
an
a
pp
li
cat
ion
that
i
m
ple
m
ented
this
al
gorithm
can
on
ly
ef
fecti
ve
to
cal
culat
e
the d
io
pter
le
vels from
-
1.12
D
to
-
5.2
6D.
Ba
sed
on
t
he
dista
nc
e
that
we
obta
in
with
Konig'
s
al
gorithm
,
we
cal
cul
at
e
the
dio
pte
r
us
in
g
the
f
ocal
distance
to
th
e
dio
pte
r
co
nversi
on
form
ula.
Algo
.
1
is
descr
i
be
d
in
the
f
ollo
wing.
First,
it
read
s
th
e
de
vice
ca
m
era
resu
lt
then
pe
rform
s
face
detect
ion
w
hi
c
h
is
us
ed
to
process
the
ey
e
tracki
ng
f
or
a
sp
eci
fic
us
e
r
ey
e
and
dete
rm
in
e
the
m
easur
ed
ey
e.
Nex
t,
t
he
ey
e
to
scree
n
distan
ce
will
be
com
pu
te
d
as
f
ocal
le
ng
th
distance
and
tra
nsfo
rm
ed
to
diopter
le
vel
in
realt
i
m
e.
Finall
y,
the
us
e
r
on
ly
need
s
t
o
m
ov
e
the
i
r
sm
artpho
ne
a
way
to
ward
his
ey
e
t
o
cal
ib
rate
thei
r
bl
ur
li
ne
f
or
sp
eci
fi
c ey
e, the
n
t
he dio
pter wil
l be
recorde
d base
d o
n
the
user
’s b
lur
li
ne
.
Algotithm 1
Algorithm of Compute Diopter
screen ← getApplicationContext()
calibrateSensor()
FaceDetectionProcess(screen)
getUserEye(screen)
drawEyeTracking(screen)
focalLeght ← getUserBlurDistance
() // in centimeter
drawBlurLine (focalLeght)
repeat for
every focal leght value.
if
( focalLeght >= 19)
diopter ← 100 / focalLeght
dr
awResult (
diopter
)
End if
Until
setUserBlurLine(true)
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
:
2088
-
8708
In
t J
Elec
&
C
om
p
En
g,
V
ol.
10
, No
.
5
,
Oct
ob
e
r
2020
:
48
92
-
48
99
4896
2.
5
.
Constr
u
cting
appl
ic
at
i
on
proto
t
yp
e
The
m
ob
il
e
app
li
cat
ion
prot
ot
ype
was
bu
il
t
for
A
ndro
i
d
suppo
rted
de
vice
s
based
on
the
insig
ht
that
we
ha
ve
on
the
us
er j
our
ney m
ap.
The
m
ai
n
featur
e o
f
this app
is
to
cal
cul
at
e
the
ey
e
power
to r
ead
s
om
e
te
x
t
in
blur
li
ne
are
a.
W
he
n
the
use
r
open
s
the
app
l
ic
at
io
n,
th
e
app
li
cat
ion
pro
vid
es
ste
p
by
ste
p
instru
ct
i
on
s
t
o
the
use
r
so
the
y
can
us
e
t
his
app
li
cat
io
n
eas
il
y.
Each
ey
e
m
ay
hav
e
dif
fe
ren
t
diopter
le
vel
s
o
this
prot
otype
is
desig
ne
d
to
cal
culat
e
each
ey
e
powe
r
(
rig
ht
or
le
ft
)
sta
rt
f
r
om
the
righ
t
e
ye
a
nd
durin
g
the
te
st,
the
oth
er
ey
e
sh
oul
d
rem
ai
n
cl
os
ed
.
T
hen
the
a
pp
li
cat
io
n
will
m
easur
e
t
he
blur
li
ne
dis
ta
nce
an
d
cal
c
ulate
the
diopt
er
le
vel
autom
at
ic
ally,
us
er
only
nee
ds
to
a
dju
st
the
sm
artph
one
unti
l
they
fin
d
t
heir
blur
li
ne
t
hen
ta
p
t
he
“r
ecord
bu
tt
on”
a
fter
t
hey
see
their
bl
ur
li
ne
from
t
he
scr
een
a
nd
us
er
will
be
ta
ken
t
o
nex
t
pa
ge
f
or
the
further
te
st
with c
onsecuti
ve
ey
e.
The
scre
en flo
w
f
or th
is use
r
interact
i
on is
dep
ic
te
d i
n
Fi
gure
3.
Figure
3
.
Use
r i
nterf
aces
of
propose
d
a
ppli
cat
ion
2.
6
.
Pr
oto
typ
e e
valua
tio
n
An
ex
pe
rim
en
t
cam
e
ou
t
to
unde
rstan
d
th
e
eff
ic
ie
ncy
a
nd
ease
of
use
of
the
pr
opos
e
d
m
ob
il
e
app
li
cat
io
n.
W
e
us
e
d
us
a
bili
t
y
te
sti
ng
to
val
idate
the
us
a
bili
ty
of
our
ap
proac
h.
Usa
bili
ty
te
sti
ng
is
the
m
os
t
of
te
n
util
iz
ed
m
et
ho
d
f
or
veri
fyi
ng
an
d
vali
dating
t
he
qual
it
y
of
so
ftwa
re
[32].
The
e
val
uation
was
pe
r
form
ed
with
the
sam
e
par
ti
ci
pa
nts
as
in
the
us
e
r
re
quirem
ents
el
ic
i
ta
ti
on
phase
an
d
ask
on
ly
10
of
them
to
do
so
m
e
ta
sk
scena
rios
as
descr
ibe
d
in
Table
1
with
our
prototype.
Wh
il
e
they
wer
e
pe
rfor
m
ing
the
ta
sks
,
their
perform
a
nce
on the tas
ks was
obse
rv
e
d an
d
a
ny pr
ob
l
e
m
s o
ccu
rr
e
d o
r
face
d by
us
er
s w
e
re
no
te
d.
Table
1.
T
ask:
m
easur
e
l
en
s
p
ow
e
r
Task
Descripti
o
n
1
Start
th
e
Ap
p
2
If
us
er
wea
r
g
lass
e
s, T
ak
e of
f
the g
lass
es.
3
Clo
se lef
t ey
e to
m
easu
re
th
e r
ig
h
t e
y
e blu
r
lin
e.
4
Use th
e app
s to
aut
o
m
aticall
y
m
easu
r
e the d
istan
ce fro
m
the u
ser's e
y
es to
t
h
e scre
en
un
til gett
in
g
the u
ser's b
lu
r
lin
e.
5
Use su
b
m
it bu
tto
n
to record th
e dis
ta
n
ce of
blu
r
lin
e and
dio
p
ter
lev
el.
6
D
o
step
3
-
5
f
o
r
lef
t ey
e
.
7
Go
to th
e r
esu
lt pa
g
e to see th
e dio
p
ter
lev
el of
bo
th
eyes
.
Usab
il
it
y
te
st
s
wer
e
co
nd
ucted
usi
ng
the
Syst
em
Usab
il
it
y
Scal
e
(S
US)
quest
ionnaire
f
or
the
assessm
ent
of
the
ap
plica
ti
on
perform
ance.
Pa
rtic
ipant
s
we
re
require
d
to
rate
t
he
te
n
m
od
ifie
d
qu
est
ion
it
e
m
s
that
include
th
ree
us
a
bili
ty
var
ia
bles:
eff
ect
ive
ness,
l
earn
a
bili
ty
,
an
d
sat
isfact
io
n
a
s
ada
pted
f
ro
m
Lewis
and
Sa
uro'
s
re
search
[33]
wi
th
one
of
five
responses
tha
t
ran
ge
from
s
tro
ng
ly
ag
ree
to
stron
gly
disagr
ee
.
W
it
h
a
n
ov
e
ra
ll
scor
e
of
80.
50
an
d
a
de
viati
on
of
4.1
1,
the
res
ult
is
quit
e
prom
isi
ng
,
w
hich
i
ndic
at
es
tha
t
the
pr
opos
e
d
app
ca
n
easi
ly
be
acce
pte
d
by
use
rs
[
34]
.
Be
sides,
pa
rtic
ipan
ts
ga
ve
posit
ive
feedba
ck
f
or
the
value
a
nd
com
fo
rt
pro
vid
ed
by
the
ins
ta
nt
resu
lt
s
of
the
ey
e
po
we
r
te
sts.
Nex
t,
w
e
com
par
e
the
app’s
resu
lt
s
with
rea
l do
ct
or m
easur
em
ent r
esults
to in
vestigat
e t
he
acc
ur
acy
of
the pr
opos
e
d
a
pp
li
cat
io
n.
Evaluation Warning : The document was created with Spire.PDF for Python.
In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
-
8708
A n
ew
pers
pect
iv
e o
f ref
ra
ct
iv
e erro
r
c
alculat
ion
wi
th
m
ob
il
e app
li
cati
on
(
Komang C
andra Br
at
a)
4897
3.
RESU
LT
S
A
ND
A
N
ALYSIS
A
direct
com
par
iso
n
was
c
onduct
ed
t
o
ex
plici
tl
y
co
m
pa
re
the
two
diopter
m
easur
em
ent
proces
s
resu
lt
s,
on
e
with
the
pro
pose
d
ap
plica
ti
on
a
nd
a
no
t
her
m
e
asur
e
d
by
the
do
ct
or
with
a
phoro
pter
an
d
Sn
el
le
n
char
t.
The
diopter
le
vel
ra
nge
f
or
each
pa
rtic
i
pan
t
was
recor
ded
a
nd
the
com
par
is
on
res
ult
as
s
how
n
in Ta
ble 2.
Table
2.
T
he
c
om
par
ison res
ul
t of
le
ns
powe
r
No
Participan
t E
y
es
Ap
p
(
Dio
p
ter)
Do
cto
r
(Diop
ter
)
Er
ror
Gap
1
Participan
t 1
R
-
2
.99
-
2
.71
0
.28
L
-
2
.63
-
2
.89
0
.26
2
Participan
t 2
R
-
2
.49
-
2
.24
0
.25
L
-
2
.47
-
2
.27
0
.2
3
Participan
t 3
R
-
1
.37
-
0
.2
1
.17
L
-
1
.1
-
0
.1
1
.2
4
Participan
t 4
R
-
1
.59
-
1
.29
0
.30
L
-
1
.59
-
1
.16
0
.43
5
Participan
t 5
R
-
2
.88
-
2
.65
0
.23
L
-
2
.9
-
2
.56
0
.34
6
Participan
t 6
R
-
2
.02
-
1
.72
0
.3
L
-
2
.03
-
1
.73
0
.3
7
Participan
t 7
R
-
2
.44
-
2
.07
0
.37
L
-
2
.41
-
2
.05
0
.36
8
Participan
t 8
R
-
1
.72
-
1
.49
0
.23
L
-
1
.73
-
1
.47
0
.26
9
Participan
t 9
R
-
2
.75
-
2
.59
0
.16
L
-
2
.71
-
2
.91
0
.20
10
Participan
t 10
R
-
2
.56
-
2
.71
0
.15
L
-
2
.48
-
2
.62
0
.14
Mean o
f
Er
ror /
De
v
iatio
n
0
.25
6
5
/
0
.08
Data
va
riabil
it
y
has
bec
om
e
a
pre
valent
is
su
e
i
n
str
uctu
r
ed
te
sti
ng.
Th
e
sm
all
value
of
sta
ndar
d
dev
ia
ti
on
(
SD)
in
the
er
r
or
ga
p
bet
wee
n
ap
p
m
easur
em
ent
and
doct
or
m
easur
em
ent
giv
es
i
nfor
m
ation
that
the
pro
po
se
d
a
pp
li
cat
io
n
can
giv
e
pa
rtic
ipa
nt
s
con
sist
ent
re
su
lt
s.
As
al
rea
dy
m
entione
d,
the
evaluati
on
resu
lt
can
determ
ine
wh
et
he
r
the
pr
op
os
e
d
ap
p
is
sat
isfact
or
y
f
or
the
r
efr
act
ive
er
r
or
m
easur
em
ent
ta
sk
s.
Ov
e
rall
,
the
accuracy
le
vel
ga
p
of
the
pro
pos
e
d
ap
plica
ti
on
is
qu
it
e
sm
all
wh
ic
h
ha
s
a
bit
le
ss
accurate
with
an
er
ror
of
le
ss
than
0.5
Di
op
t
er
(Mea
n=0.25
6,
S
D
= 0
.
08).
Ev
e
n
th
ough
th
e
pro
po
se
d
a
pp
has
a
sli
ghtl
y
good
resu
lt
,
it
is
no
te
w
or
t
hy
that
there
wer
e
si
gn
i
ficant
de
viati
on
s
beca
us
e
the
pr
op
os
e
d
app
can
’t
m
easur
e
the
norm
al
eye
accuratel
y
(
with
the
e
rror
of
great
er
th
an
1
Di
op
te
r
).
The
m
os
t
interest
ing
res
ult
of
ou
r
evaluati
on
is
the
pa
rtic
ipant
ov
e
rall
sta
te
s
t
hat
the
intuit
iv
e
pr
ese
ntati
on
of
the
pr
opos
e
d
ap
p
m
akes
th
e
m
feel
easy
to
m
on
it
or t
heir
eye
c
onditi
on
i
nd
i
vidu
al
ly
.
4.
CONCL
US
I
O
N
This
pa
per
pro
po
s
es
a
m
ob
il
e
app
li
cat
ion
th
at
can
m
easur
e
the
diopter
le
vel
of
a
pe
rs
on
on
ly
us
i
ng
fron
t
face
c
a
m
era
an
d
bu
il
t
-
in
sm
artphone
sens
ors.
Th
e
offli
ne
proc
ess
of
t
he
propose
d
a
pp
m
akes
i
t
acce
ssible
for
ever
y
on
e
e
ven
fo
r
rem
ote
area
us
ers
.
A
use
r
can
m
easur
e
the
blu
r
li
ne
distance
an
d
c
al
culat
e
the d
i
op
te
r
le
ve
l autom
at
ic
all
y. The ge
ner
al
obj
ect
ive
of th
e p
r
opose
d ap
pl
ic
at
ion
is to s
uppo
rt the a
vaila
bili
ty
of
ey
e
healt
h
serv
ic
e
f
or
al
l
the
people
in
Indonesia
w
ho
are
in
need,
without
bein
g
con
st
raine
d
by
their
econom
y
and
r
egio
n
s
o
t
hat
e
ach
in
div
i
dual
hav
e
op
portu
ni
ty
to
m
a
intai
n
their
ey
e
c
ondi
ti
on
in
de
pende
ntly.
The
e
valuati
on
res
ults
show
that
the
pro
pos
ed
prototype
i
s
quit
e
su
cces
s
fu
l
in
m
easur
in
g
the
diopter
le
vel
with
0.2
5
di
op
t
er
of
a
n
er
ror
on
ave
rag
e
.
Thi
s
app
li
cat
ion
is
no
t
inten
de
d
to
re
place
the
opti
ci
an'
s
reg
ula
r
fu
ll
exam
inati
on
r
esults.
T
he
f
ul
l
ey
e
te
st
aft
er
usi
ng
the
app
li
cat
io
n
is
sti
ll
necessar
y
for
ch
r
on
ic
cases.
In
the
f
uture,
w
it
h
f
ur
the
r
an
al
ysi
s
and
accuracy
im
pr
ov
e
m
ent,
the
propose
d
ap
plica
ti
on
co
uld
pr
ov
i
de
a
big
help
i
n
m
on
it
ori
ng eye
c
onditi
on
s
to dete
ct
e
ye
d
ise
ases a
nd
visu
al
ac
uity
level i
n
t
heir
e
arly
stages.
REFERE
NCE
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8708
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In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
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8708
A n
ew
pers
pect
iv
e o
f ref
ra
ct
iv
e erro
r
c
alculat
ion
wi
th
m
ob
il
e app
li
cati
on
(
Komang C
andra Br
at
a)
4899
BIOGR
AP
H
I
ES
OF
A
UTH
ORS
Komang
Can
d
ra
Brata
is
a
le
c
ture
r
in
the
Facul
t
y
of
Co
m
pute
r
Scie
nc
e,
Univer
sita
s
Brawij
a
y
a
,
Indo
ensia
.
He
r
ec
e
iv
ed
th
e
MS
c
deg
ree
in
th
e
Dep
a
rtment
of
Com
p
ute
r
Sci
ence
and
Inform
at
ion
Engi
ne
eri
ng,
N
a
ti
onal
C
ent
r
al
U
nive
rsit
y
,
Taiwa
n
in
2014
as
an
Inte
rna
ti
ona
l
Dual
Degre
e
Master
student
be
twee
n
the
Univ
ersity
of
Br
awija
y
a,
Indone
si
a
and
Nati
ona
l
Cent
ra
l
Unive
rsit
y
,
T
ai
wan
.
He
complet
ed
hi
s
Bac
hel
or
'
s
de
gre
e
in
the
De
par
tment
of
Inform
at
ic
s E
ng
i
nee
ring
,
Univer
s
ity
of
Brawi
jay
a
,
Indone
sia in
20
12.
His re
sea
r
ch int
er
est
ar
ea
are
in
the
ar
ea
s
of
software
engi
nee
r
ing
and
in
form
at
ion
te
chn
olog
y
,
user
exp
eri
en
ce,
HCI
,
m
obil
e
app
li
c
ati
on
developm
ent
,
distri
but
ed
s
y
ste
m
s,
and
augment
ed
re
al
i
t
y
.
Mukh
ammad
Sh
ari
f
Hi
day
at
ulloh
complet
e
d
his
Bac
hel
or
degr
ee
in
De
par
tment
of
Inform
at
ic
s
Eng
ine
er
ing,
Univer
sita
s
Brawij
a
y
a
,
Indone
sia
in
201
7.
His
rese
arc
h
i
nte
rest
are
a
are
in
the
area
s
of
software
engi
nee
r
ing
and
informati
on
tec
hnolog
y
,
m
obil
e
appl
icat
ion
deve
lopment
,
an
d
m
ac
hine l
ea
rn
i
ng.
Lu
tfi
Fanan
i
i
s
a
Lectu
re
r
in
the
Dep
art
m
e
nt
of
Inform
at
i
cs
Engi
ne
eri
ng
,
Univer
sita
s
Brawij
a
y
a
.
He
r
ec
e
ive
d
th
e
MS
c
degr
ee
in
Dep
a
rtment
of
Com
pute
r
Sci
ence
and
Inform
at
ion
Engi
ne
eri
ng,
Na
ti
onal
C
ent
r
al
U
nive
rsit
y
,
Taiwa
n
in
2014
as
an
Inte
rna
ti
ona
l
Dual
Degre
e
Master
studen
t
bet
wee
n
Univer
sit
y
of
Brawi
jaya,
Indon
esia
and
Nati
on
al
C
ent
r
al
Univ
ersit
y
,
Ta
iwan
.
His
rese
arc
h
intere
st
are
in
the
ar
eas
of
software
engi
nee
r
ing
and
informati
on
te
chno
log
y
,
user
expe
r
ie
n
ce de
si
gn,
and
m
obil
e
a
ppli
c
at
ion
dev
elopm
ent
.
Ad
am
He
nd
ra
Brata
is
a
L
ec
tu
rer
in
the
Depa
r
t
m
ent
of
Inform
a
ti
cs
Eng
ineeri
ng,
Univer
sit
as
Brawij
a
y
a
.
He
r
ec
e
ive
d
th
e
MS
c
degr
ee
in
Dep
a
rtment
of
Com
pute
r
Sci
ence
and
Inform
at
ion
Engi
ne
eri
ng,
Na
ti
onal
C
ent
r
al
U
nive
rsit
y
,
Taiwa
n
in
2014
as
an
Inte
rna
ti
ona
l
Dual
Degre
e
Master
studen
t
bet
wee
n
Univer
sit
y
of
Brawi
jaya,
Indon
esia
and
Nati
on
al
C
ent
r
al
Univ
ersity
,
Ta
iwan
.
His r
ese
arc
h
int
e
rest is in t
he
ar
ea
s of
software
engi
n
ee
ri
ng.
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