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17TH INTERNATIONAL CONFERENCE ON GEOMETRY AND GRAPHICS ©2016 ISGG
4–8 AUGUST, 2016, BEIJING, CHINA
Paper #00
IMPRESSION EVALUATION OF PAPER FOLDING LAMPSHADE BY
DANISH STUDENTS
Naoki ODAKA1, Hirotaka SUZUKI1, Poul Henning KIRKEGAARD2,
Werner OSTERHAUS2 and Atsumi OKAMURA1
1Kobe University, Japan 2Aarhus University, Denmark
ABSTRACT: Lampshade was developed as wind shield for light source when fire was used for
light source. Though contemporary light sources, like LED lamp, fluorescent lamp and incandes-
cent light, are working with electricity and wind shield is not required for the light sources, almost
all light sources are still covered by lampshade to arrange or control luminous flux from light
source. And combination of lampshades and light sources may give distinctive impression to sur-
rounding people. Among many types of lampshade, authors paid attention to shades of surrounding
type made by diffuse transmitting material without printed texture since the type is following basic
role of lampshade, decreasing luminance level of light source and softening flow of light. Using
white paper without printed texture, authors constructed several lampshades by paper folding tech-
nique and surrounded two types of light source with the shades for subjects experiment. And au-
thors performed semantic differential for Danish students to evaluate how forms, bump texture and
color temperature are affected on impression of the students.
Keywords: Lampshade, Paper folding, Color temperature, Impression evaluation, Semantic differ-
ential, Factor analysis, Illuminance distribution.
1. INTRODUCTION
In the past time, fire was used for light source
and lampshade was developed as a wind shield
for the fire at first. Though contemporary light
sources, like LED lamp, fluorescent lamp and
incandescent light, are working with electricity
and wind shield is not required for light source,
almost all light sources are still covered by
lampshade to arrange or control luminous flux
from light source. And combination of
lampshades and light sources may give distinc-
tive impression to surrounding people. Among
many types of lampshade, authors paid atten-
tion to shades of surrounding type made by
diffuse transmitting material without printed
texture since the type is following basic role of
lampshade, decreasing luminance level of light
source and softening flow of light.
In the world, lampshades of this kind are
widely used in many countries. Among these
countries, Denmark is considered as one of the
most typical country as the world famous
lampshade company is producing lampshades
by paper folding and plastic folding. Though
final purpose of author’s activities is evaluation
of effect of nationality on impression of
lampshades, authors started the survey for
Danish people at first.
Using white paper without printed texture,
authors constructed several lampshades by pa-
per folding technique and surrounded two types
of light source with the shades for subjects ex-
periment. And authors performed semantic
differential for Danish students to evaluate how
shape, bump texture and color temperature are
affected on impression of the students. Using
result of semantic differential, correlation
analysis, factor analysis, comparison between
psychological quantity and physical quantity
were performed to evaluate impression of Dan-
ish students.
2
2. COMBINATION OF LAMPSHADES
AND LIGHT SOURCES
2.1 Forms of lampshades and bump textures
In the field of paper folding, Pseu-
do-Cylindrical Concave Polyhedral (hereafter,
PCCP) shell is containing beautiful bump tex-
ture though the shell structure is made from a
planar paper as shown in Figure 1.
As shown in Figure 2, development of cylin-
drical PCCP shell has two sets of oblique par-
allel lines at even intervals for mountain fold
and one set of horizontal parallel lines at even
intervals for valley fold. Cylindrical shape
shown in Figure 1 appears after folding the de-
velopment along with the lines drawn in the
development and bending the development to
attach bilateral sides without gap and overlap.
PCCP shell is one of the most famous
shapes constructed by paper folding methods.
Yoshimura pointed out similarity between
shape of PCCP shell and shape made by buck-
ling of cylindrical shell with compressive pow-
er[1]. Miura named the shape as Pseu-
do-Cylindrical Concave Polyhedral and sur-
veyed features of PCCP shell[2].
PCCP shell has been applied to structure of
building roof[3] and shape of cans for beverage.
Besides cylindrical shape, dome type shape had
been proposed as well[4]. PCCP shell can be
considered as layered regular antiprism as
shown in Figure 3 and number of vertices of
the antiprism can be changed.
From the viewpoint of luminosity contrast,
each flat diamond on the development of PCCP
structure changes its shape to skew quadrilat-
eral unit and the unit is constructed by two
planer triangles, and luminance distribution in
the area of the unit is discontinuous at bounda-
ry of the two triangles, consequently.
Considering existence of many variation and
beautiful bump texture, authors decided to
adopt PCCP shell for shape of lampshade. And
PCCP shell based on regular hexagonal an-
tiprism, the shell based on regular triangular
antiprism and dome PCCP shell were selected
for subjects experiment.
And Suzuki found that similar shape can be
constructed from the development of PCCP
shell as shown in Figure 4[5]. After folding the
development shown in Figure 2 along with only
lines for mountain fold and bending it, the
shape shown in Figure 4 appears. Suzuki
Figure 1: An example of PCCP shell.
Figure 2: A development of PCCP shell
(Black horizontal lines for mountain fold
and grey oblique lines for valley fold).
Figure 3: Layered 2 regular hexagonal
antiprisms.
3
named the folding method as ‘Skew Quadrilat-
eral Elastic Folding’[6] and Suzuki et al. named
the cylindrical shape constructed by SQEF as
Pseudo-Cylindrical Concave Curves (hereafter,
PCCC) shell[7]. In case of PCCC structure,
each skew quadrilateral is constructed by con-
tinuous curved surface and illuminance distri-
bution is continuous within area of the unit
quadrilateral as shown in Figure 4. From the
viewpoint of shape, difference between two
shapes is trivial, however, from the viewpoint
of illuminance distribution, difference between
two shapes is significant.
Authors considered that existence of valley
folds and shape of lampshade may be signifi-
cant factors for impression evaluation. Finally,
authors introduced 4 forms, ‘cylinder’, ‘pseu-
do-cylinder based on regular triangular
antiprism’, ‘pseudo-cylinder based on regular
hexagonal antiprism’ and ‘dome’, and intro-
duced 7 shapes from the 4 forms considering
existence of valley folds as shown in Table 1.
2.2 Color temperature of light sources for
the lamp lampshades
As light sources for the lampshades, LED lamp
of the neutral white color (total flux 320lm,
Figure 4: A lamp shade work ‘Legato’[5].
Table 1: The combination the forms, existence of valley folds, color temperature and
abbreviations of each case.
Form
Valley
Fold Lines
Color
Temperatures
Abbreviations
Cylinder
Exist
Non-Exist
NW
Cy_NW
LB
Cy_LB
Pseudo-cylinder based on regular
triangular antiprism
Exist
NW
CP6_NW
LB
CP6_LB
Non-Exist
NW
CC6_NW
LB
CC6_LB
Pseudo-cylinder based on regular
hexagonal antiprism
Exist
NW
CP3_NW
LB
CP3_LB
Non-Exist
NW
CC3_NW
LB
CC3_LB
Dome
Exist
NW
CPD__NW
LB
CPD_LB
Non-Exist
NW
CCD_NW
LB
CCD_LB
Cy_NW
CP6_NW
Cy_LB
CP6_LB
CC6_NW
CC6_LB
CP3_LB
CP3_NW
CC3_NW
CC3_LB
CCD_LB
CPD_LB
CPD_NW
W
CCD_NW
Figure 5: 14 slides used in the subject experiment with semantic differential.
4
color temperature 5,000K) and that of the light
bulb color (total flux 260lm, color temperature
2,800K) were used. Combining 7 shapes of
lampshades and 2 LED lamps, 14 slides were
obtained in total as shown in Figure 5.
3. CONDITIONS OF SUBJECTS EXPER-
IMENT
3.1 Conditions of semantic differential
Authors adopted semantic differential to sub-
jective experiment for impression evaluation.
Semantic differential is a method for impres-
sion evaluation by rating examinee’s evaluation
on scale of bipolar adjectives. As bipolar ad-
jectives, 10 adjective pairs were selected as
shown in Table 2, considering past experiment
for similar evaluation. 7 steps scale was used in
semantic differential.
3.2 Conditions of examinees
27 male and female Danish students (from 22
to 31 years old) participated in the experiment.
The slides shown in Figure 5 were projected in
small and dark room, and examinees were di-
vided into 6 groups to enter into the small room.
Average scores by 27 examinees for each slide
and for each question were obtained and the
scores were considered as representative score
for each slide and for each question.
4. RESULT OF SEMANTIC DIFFEREN-
TIAL
4.1 Correlation analysis with score of Q7
(Like-Dislike)
The score of Q7 (Like-Dislike) can be consid-
ered as comprehensive preference, and value of
correlation coefficient between the score of Q7
and that of other questions can be evaluated as
strength of relation between comprehensive
preference and other factor.
From absolute value of correlation coeffi-
cient between Q7 and other questions, follow-
ing order was obtained.
Q2(+)>Q5(-)>Q9(+)>Q1(+)>Q10(-)>…..
This order shows that Danish students tend
to prefer ‘varied’, ‘artificial’ and ‘pleasant’
lampshades.
4.2 Analysis of relation between impression
evaluation and shapes of lampshades
From viewpoint of shape, it is difficult to ex-
tract some consideration in total since forms of
lampshades used for subjects experiment were
much varied. Authors paid attention to three
shapes of similar sizes and similar forms, Cy,
CP6 and CC6. Among these three shapes, Cy is
quite ‘Simple’, and CC6 (without valley fold
lines) is more varied and brighter comparing to
CP6 (with valley fold lines), as shown in Figure
6.
Table 2: 10 adjective pairs for semantic
differential.
Adjective Pairs
Q1
Comfort
<--->
Discomfort
Q2
Varied
<--->
Simple
Q3
Bright
<--->
Dark
Q4
Warm
<--->
Cool
Q5
Natural
<--->
Artificial
Q6
Calming
<--->
Agitating
Q7
Like
<--->
Dislike
Q8
Soft
<--->
Hard
Q9
Pleasant
<--->
Unpleasant
Q10
Quiet
<--->
Noisy
Figure 6: Result of semantic differential
method analysis for 6 slides out of 14.
5
4.3 Analysis of relation between impression
evaluation and colors of light sources
From viewpoint of color, relationship be-
tween psychological brightness obtained from
semantic differential and physical brightness
obtained with illuminance meter was examined.
The value of vertical illuminance was meas-
ured at the point 1467mm off from projected
screen. As shown in Figure 7, Danish students
clearly evaluated NW lamp, which color tem-
perature is higher, as brighter comparing to LB
lamp of same luminous flux.
And authors also performed factor analysis
(the main factor method, varimax rotation) us-
ing whole result of semantic differential score
except Q7 (Like-Dislike) since the result of Q7
can be considered as total impression evalua-
tion. After the varimax rotation, three axes
were extracted from the analysis and matrix of
factor loading was obtained as shown in Table
3. And Figure 8 shows scatter plot of factor
scores by Danish students (factor I v.s. II).
These results show that the first axis obtained
from factor analysis is strongly related to color
temperature of light sources.
5. CONCLUSIONS
To make clear impression evaluation of paper
folding lampshades by Danish students, authors
performed semantic differential experiment
with 10 adjective pairs for 27 Danish students.
From the result of the experiment, authors ob-
tained influence of luminance, shape of
lampshades and color temperatures of light
source on impression evaluation.
Authors would like to increase the number
of examinees to extract more precise structure
of evaluation in future, and also like to extend
variation of material to examine influence of
color of materials and transmission characteris-
tics.
Figure 7: Relation between psychological
brightness score and vertical illuminance.
Table 3: Matrix of factor loading obtained
from factor analysis.
Factor I
Factor II
Factor III
Warm-Cool
0.9735
-0.1164
0.0686
Bright-Dark
-0.9034
-0.2445
-0.2312
Soft-Hard
0.7848
0.3967
0.2804
Calming-Agitating
0.6994
0.3252
0.5892
Natural-Artificial
0.0081
0.9644
-0.0671
Varied-Simple
-0.1457
-0.9570
0.0580
Quiet-Noisy
0.4610
0.7884
0.3892
Pleasant-Unpleasant
0.0717
0.0291
0.9032
Comfort-Discomfort
0.3479
-0.0896
0.8558
Figure 8: Scatter plot of factor scores by
Danish students (factor I v.s. II).
6
ACKNOWLEDGMENTS
This research activity was supported by re-
search grant of Union Foundation for Ergode-
sign Culture.
REFERENCES
[1] Yoshimura, Y.. On the Mechanism of
Buckling of a Circular Cylindrical Shell
under Axial Compression. Reports of The
Institute of Science and Technology (The
University of Tokyo), Vol. 5, No.5, 1951:
179-198 (in Japanese).
[2] Miura, K.. Proposition of Pseudo- Cylindri-
cal Concave Polyhedral Shells. Institute of
Space and Aeronautical Science University
of Tokyo Report No. 442, 1969: 141-163.
[3] Salvadori, M.. BUILDING: The Fight
Against Gravity, Atheneum, 1979.
[4] Miyazaki, K.. Encyclopaedia of Building
Shape, Shokokusha Publishing, 2000 (in
Japanese).
[5] Suzuki, H.. Legato. Proc. of the Fall Annul
Conference of the Japan Society for
Graphics Science, 2014: 200-201 (in Japa-
nese).
[6] Suzuki, H.. A PROPOSAL OF PAPER
FOLDING METHOD FOR LAMPSHADE
DESIGN -PRINCIPLE AND APPLICA-
TION OF SKEW QUADRILATERAL
ELASTIC FOLDING METHOD. Proceed-
ings of The 10th Asian Forum on Graphic
Science, 2015: F23.
[7] Suzuki, H., Kirkegaard, P. H., and Odaka,
N.. SHAPE ANALYSIS OF PCCC SHELL
STRUCTURE BY GEOMETRICAL
FEATURES –A STABLE SHELL
STRUCTURE BETWEEN CYLINDER
AND PCCP SHELL-, Proc. of 17th Intl.
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2016: in Printng
ABOUT THE AUTHORS
1. Naoki ODAKA, Dr. Eng., in a professor
of Department of Human Development, Grad-
uate School of Human development and envi-
ronment, Kobe University.
2. Hirotaka SUZUKI, Dr. Eng., is an associ-
ate professor of Department of Architecture,
Graduate School of Engineering, Kobe Univer-
sity.
3. Poul Henning KIRKEGAARD, PhD., is a
professor of Department of Engineering, Aar-
hus University.
4. Werner OSTERHAUS, PhD., is a professor
of Department of Engineering, Aarhus Univer-
sity.
5. Atsumi OKAMURA, is graduate student of
Department of Architecture, Graduate School
of Engineering, Kobe University.
