KelpFusion - Korea Universitykucg.korea.ac.kr/new/seminar/2015/ppt/ppt-2015-01-06.pdfComputer...
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KelpFusion :A Hybrid Set Visualization Technique
Copyright of figures and other materials in the paper belongs original authors.
Presented by Sanghyeok LEE
2014. 12. 23
Computer Graphics @ Korea University
IEEE Transactions o visualization and computer graphics (2013)
Meulemans et al.
Sanghyeok Lee | 2015. 01. 06 | # 2Computer Graphics @ Korea University
Part 1. Introduction1. Introduction
2. Related work
Part 2. Algorithm3. KelpFusion overview
4. KelpFusion analysis
Part 3. Verification5. User Study
6. Conclusion and Future work
Index
Part 1. Introduction
KelpFusion : A Hybrid Set Visualization Technique
Sanghyeok Lee | 2015. 01. 06 | # 4Computer Graphics @ Korea University
1. Introduction
Exploring large information spaces
• Grouping of elements by their properties
Sanghyeok Lee | 2015. 01. 06 | # 5Computer Graphics @ Korea University
• Venn diagrams
• Euler diagrams
• 문제점
복잡한 교차점
타원
1. Introduction
Sets and elements representation
Sanghyeok Lee | 2015. 01. 06 | # 6Computer Graphics @ Korea University
• Bubble Sets
폐색
• LineSets
• Kelp Diagrams
1. Introduction
Sets and elements representation (2)
Sanghyeok Lee | 2015. 01. 06 | # 7Computer Graphics @ Korea University
• Kelp Diagram 의 발전형
Spanning graph
+ shortest-path graph
• Hybrid technique
mix of hulls and lines
• Minimal spanning tree + convex hull
fitted boundaries for groups of elements
• Interactive manipulation
𝒕, 𝑨 parameter
• Hypergraph visualization
1. Introduction
About KelpFusion
Sanghyeok Lee | 2015. 01. 06 | # 8Computer Graphics @ Korea University
1. Introduction
About KelpFusion (2)
Sanghyeok Lee | 2015. 01. 06 | # 9Computer Graphics @ Korea University
• Popular ways to visually represent set intersections
• Papers
automatically drawing
adding labels or glyphs
2. Related Work
Venn, Euler diagrams
Citation [14] Citation [16] Citation [15]
Sanghyeok Lee | 2015. 01. 06 | # 10Computer Graphics @ Korea University
• A method based on ‘isocontours’ (level sets) to overlay such an arrangement with enclosing set regions
• Readability of regions in these methods suffers when they are highly overlapping
2. Related Work
Bubble sets
Sanghyeok Lee | 2015. 01. 06 | # 11Computer Graphics @ Korea University
• Improve the readability of complex set intersections
• LineSets
set : simple curved line 으로 표현
grouping 의 새로운 개념 제안
• Kelp diagrams
bubble and stick, + hypergraph 개념 확장
• 주요특징
set 과 member 를 특정 위치에 고정
2. Related Work
LineSets and Kelp diagrams
Sanghyeok Lee | 2015. 01. 06 | # 12Computer Graphics @ Korea University
• Kelp Diagram 의 발전형
Spanning graph
+ shortest-path graph
• Hybrid technique
mix of hulls and lines
• Minimal spanning tree + convex hull
fitted boundaries for groups of elements
• Interactive manipulation
𝒕, 𝑨 parameter
2. Related Work
About KelpFusion (again)
Part 2. Algorithm
KelpFusion : A Hybrid Set Visualization Technique
Sanghyeok Lee | 2015. 01. 06 | # 14Computer Graphics @ Korea University
• Hybrid
edges + filled faces
• Interaction
User-controlled tradeoff
• minimal spanning tree convex hull
• Kelp Diagrams 과의 차이점
filled faces 의 규칙 추가
legibility rules 의 추가
edges 의 생성 규칙
3. KelpFusion overview
Features
Sanghyeok Lee | 2015. 01. 06 | # 15Computer Graphics @ Korea University
• Kelp diagrams
minimal spanning tree
detour(우회로) 요소
• KelpFusion
minimal spanning tree
shortest-path graph
• 더 많은 의미 부여
• filled faces 의 다양성
3. KelpFusion overview
Edges definition
Sanghyeok Lee | 2015. 01. 06 | # 16Computer Graphics @ Korea University
• 용어 정리
𝑵 : set of nodes
𝑺𝟏, … , 𝑺𝑲 : sets (앞 뒤 순서를 결정)
𝒗 : nodes (assigned unique allocation area)
allocation area : 각 node들이 확보한 여백. Voronoi cell 로 정의
• Voronoi cell (시드 점들과의 거리에 따라 평면을 분할한 그림)
𝒓 ∶ radius of allocation area
𝒘 ∶ rendered edge width
3. KelpFusion overview
Preliminaries (예비절차)
Sanghyeok Lee | 2015. 01. 06 | # 17Computer Graphics @ Korea University
• 𝑺𝟏, … , 𝑺𝑲 : sets (앞 뒤 순서를 결정)
front-to-back ordering
• How?
try all possible orderings? X
number of intersection? X
그냥 set 의 사이즈가 작은 순서대로 앞으로 배정 O
• the most readable results
• heuristic solution
3. KelpFusion overview
Set order
Sanghyeok Lee | 2015. 01. 06 | # 18Computer Graphics @ Korea University
• 3 phase
shortest-path graph
fillable faces
visualization
3. KelpFusion overview
Algorithm overview
Sanghyeok Lee | 2015. 01. 06 | # 19Computer Graphics @ Korea University
• 2 parameter
𝒕 (phase 1)
• control the density of the graph
𝑨 (phase 2)
• control the size of the fillable faces
• Phase-by-phase basis, rather than set by set
Possibilities for parallel processing
3. KelpFusion
Algorithm overview (2)
Sanghyeok Lee | 2015. 01. 06 | # 20Computer Graphics @ Korea University
Reachability graph G (superset)
Shortest-path graph (t )
• Algorithm
Fillable Faces (A )
• Three rules (면적, 포함관계, 불명확성)
Visualization
• Smoothing, Color, outline, transparency
Implementation
• 각 단계별 속도향상 정책
3. KelpFusion
Summary
Sanghyeok Lee | 2015. 01. 06 | # 21Computer Graphics @ Korea University
• reachability graph 𝑮
𝑮 contains an edge for each pair of nodes 𝑢, 𝑣 in 𝑆𝑖
edge 𝑢, 𝑣 and its length
• Shortest Euclidean route between 𝑢 and 𝑣
• Avoid allocation area (with 0.5 𝒘)
• Visibility tangent graph
4. KelpFusion analysis
Algorithm – Phase 1: Shortest-path graph
Sanghyeok Lee | 2015. 01. 06 | # 22Computer Graphics @ Korea University
• Shortest-path graph
𝒕 값에 따라 변동 (𝒕 ≥ 1)
• minimal spanning tree convex hull 변동
SPG(Si, t) 알고리즘
SPG(Si, 1) : complete graph(convex hull)
SPG(Si, ∞) : minimal spanning tree
4. KelpFusion analysis
Algorithm – Phase 1: Shortest-path graph (2)
Sanghyeok Lee | 2015. 01. 06 | # 23Computer Graphics @ Korea University
4. KelpFusion analysis
Algorithm – Phase 1: Shortest-path graph (3)
Sanghyeok Lee | 2015. 01. 06 | # 24Computer Graphics @ Korea University
• face를 채우는 것의 장단점
• 4가지 rule
4. KelpFusion analysis
Algorithm – Phase 2: Fillable faces
Sanghyeok Lee | 2015. 01. 06 | # 25Computer Graphics @ Korea University
• Smooth the polygon boundary
• Unique color
• Thin gray outline
• Subtract the allocation area
• Slight transparency(20 percent)
4. KelpFusion analysis
Algorithm – Phase 3: Visualization
Sanghyeok Lee | 2015. 01. 06 | # 26Computer Graphics @ Korea University
• Phase 1
reachability graph 𝑮 들로네삼각분할(Delaunay triangulation) 로 정의
• Superset 의 크기 감소: 계산감소
𝒕 –value precomputing
• Allowing for interactivity
Insertion order 재설정
• 𝒕 -value 가 줄어듦에 따라graph가 성장 weight 에 가중치를 줘서 order
변경. visualization 부분의 계산을빠르게 해줌
4. KelpFusion analysis
Implementation속도향상을 위한 phase 1 구현 최적화 방향
Sanghyeok Lee | 2015. 01. 06 | # 27Computer Graphics @ Korea University
• 𝒕 -value, 𝑨 -value
Interactively
Independently
• Result (see fig)
4. KelpFusion analysis
Implementation (2)
Sanghyeok Lee | 2015. 01. 06 | # 28Computer Graphics @ Korea University
• Allocation area
• Thinning areal features
• Right-angle crossings
4. KelpFusion analysis
Other Design Considerations
Part 3. Verification
KelpFusion : A Hybrid Set Visualization Technique
Sanghyeok Lee | 2015. 01. 06 | # 30Computer Graphics @ Korea University
• 실험 설계
Bubble Sets 과 LineSets 기법 각각 비교
3가지 기법 x 4가지 example x 2가지 난이도 x 3번 반복
13명의 참가자
• 왜 Kelp Diagram 기법과는 비교를 안 하나?
현 실험에서는 더 이상의 조건을 추가하여 실험하는 것은참가자들의 피로를 줄 수 있음
5. User Study
Method
VS
Bubble Sets LineSets KelpFusion
Sanghyeok Lee | 2015. 01. 06 | # 31Computer Graphics @ Korea University
• Data sets
Real data of restaurant locations in the Boston area (from Bing Maps)
• Tasks
Multiple-choice answers to encourage participants to rely on their visual perception
5. User Study
Method
Sanghyeok Lee | 2015. 01. 06 | # 32Computer Graphics @ Korea University
• Participants and apparatus(장치)
13 participants (7 male and 6 females)
Age : 27~47 (mean age : about 28)
Not programmers
None being colorblind
Individual PC, using a 24’’ widescreen monitor(1900x1200)
• Procedure(절차)
Instructed with each visualization technique
Advancing from easier to harder tasks
Isomorphic question : flipped horizontally and vertically
Limit each question time : 40 seconds
Measuring accuracy and completion time
5. User Study
Method (2)
Sanghyeok Lee | 2015. 01. 06 | # 33Computer Graphics @ Korea University
H1 : • KelpFusion 과 LineSets은 이미지가 겹치는 부분을 줄여 Bubble Sets 보다 빠르고
정확할 것이다.
H2 :• KelpFusion 은 LineSet보다 더 좋은 overview를 제공할 것. SizeOverview 에서 더
좋을 것이다.
H3 :• KelpFusion 의 closed face 는 LineSet의 지그재그보다 더 명확하여
SetIntersection 에서 더 좋을 것이다.
H4 : • LineSet 은 선으로 순차적으로 연결되어 KelpFusion 보다 SizeCount 에서 더
좋을 것이다.
H5 :
• KelpFusion 은 밀집공간에서도 각 노드를 잘 표현하여 Setmembership에서더 좋을 것이다.
H6 :• KelpFusion 과 Bubble sets은 LineSets 보다 그룹을 더 잘 표현할 것이다.
H7 :
• KelpFusion 은 LineSet보다 미학적이고, Bubble sets보다 덜 어수선할것이다.
5. User Study
Hypotheses
Sanghyeok Lee | 2015. 01. 06 | # 34Computer Graphics @ Korea University
5. User Study
Results
• RM-ANOVA (반복측정 분산분석)
반복되는 측정값을 가진 군간의 유의성을 알아보고자 하는 경우
정확도 평균 정답시간 평균
Sanghyeok Lee | 2015. 01. 06 | # 35Computer Graphics @ Korea University
5. User Study
Results (2)
• Subjective user ratings for each technique
Error bars represent two standard errors. Significant differences are observed in all rankings
1 : bad5 : good
Sanghyeok Lee | 2015. 01. 06 | # 36Computer Graphics @ Korea University
5. User Study
Summary and Limitations H1 : 검증
• KelpFusion 과 LineSets은 이미지가 겹치는 부분을 줄여 Bubble Sets 보다 빠르고정확할 것이다.
H2 : 검증• KelpFusion 은 LineSet보다 더 좋은 overview를 제공할 것. SizeOverview 에서 더
좋을 것이다.
H3 : 검증 실패• KelpFusion 의 closed face 는 LineSet의 지그재그보다 더 명확하여
SetIntersection 에서 더 좋을 것이다.
H4 : 거짓으로 검증• LineSet 은 선으로 순차적으로 연결되어 KelpFusion 보다 SizeCount 에서 더
좋을 것이다.
H5 : 검증 실패
• KelpFusion 은 밀집공간에서도 각 노드를 잘 표현하여 SetMombership에서더 좋을 것이다.
H6 : 검증• KelpFusion 과 Bubble sets은 LineSets 보다 그룹을 더 잘 표현할 것이다.
H7 : 검증
• KelpFusion 은 LineSet보다 미학적이고, Bubble sets보다 덜 어수선할것이다.
Sanghyeok Lee | 2015. 01. 06 | # 37Computer Graphics @ Korea University
1. KelpFusion 의 강점 정리
1. Hybrid
2. Single parameter
2. 실험 정리
1. 가장 뛰어난 기법으로 검증
2. 정확성에서 bubble sets 보다 명확히 뛰어남
3. 정확성에서 LineSets 보다 약간 뛰어남
4. 완료시간에서 두 기법보다 명확히 뛰어남
5. linear와 areal을 합친 기법은 좋은 시각화 방법임을 검증
3. Future work
1. 다른 기존 기법과 마찬가지로, 교차구간의 복잡성 해결이 시급
2. 큰 데이터 셋을 interactive하게 통합하는 기법 필요
3. visualization 단에서 요소를 추가 삭제하는 안정성 필요
6. Conclusion and Future work