.............................................................................................................................................
ii Acknowledgements
.....................................................................................................................
iii Table
of
Contents
..........................................................................................................................
iv List
of
Figures
.................................................................................................................................
vi List
of
Tables
...............................................................................................................................
viii Chapter
1
Introduction
................................................................................................................
1 1.1
Motivation
..........................................................................................................................................
3 1.2
Problem
Statement
..........................................................................................................................
5 1.3
Thesis
Contribution
.........................................................................................................................
6 1.4
Author’s
Publication
.......................................................................................................................
6 1.5
Thesis
Organization
........................................................................................................................
7 Chapter 2 Background and Related Work
...................................................................
9 2.1
Trust
in
Social
Networks
................................................................................................................
9 2.1.1
Defining
Trust
...............................................................................................................................................
9 2.1.2
Online
Social
Networks
..........................................................................................................................
13 2.1.3
Trust
in
Online
Social
Networks
........................................................................................................
15 2.2
Advogato
Trust
Metric
..................................................................................................................
20 2.3
Related
Work
...................................................................................................................................
23 Chapter
3
Identifying
People
of
Trust
.................................................................................
29 3.1
Overview
...........................................................................................................................................
29 3.2
Problem
Formalization
................................................................................................................
30 3.3
Adapted
Advogato
Algorithm
.....................................................................................................
31 3.3.1
Assigning
a
Capacity
to
a
Seed
Node
................................................................................................
31 3.3.2
Building
a
Weighted
Personal
Network
.........................................................................................
33 3.3.3
Propagating
the
Capacity
through
the
Personal
Network
......................................................
39 v 3.3.4
Capacity-‐first
Maximum
Flow
.............................................................................................................
42 Chapter 4 Application Scenarios
....................................................................................
50 4.1
System
Overview
............................................................................................................................
51 4.2
Controlling
Access
Permission
in
Social
Network
Services
.............................................
54 4.3
Recommending
New
Friends
.....................................................................................................
58 Chapter 5 Experiments and Results
.............................................................................
62 5.1
Experimental
Networks
...............................................................................................................
62 5.2
Evaluation
Design
and
Metrics
..................................................................................................
63 5.2.1
Evaluation
Metrics
....................................................................................................................................
64 5.2.2
Baseline
Algorithms
.................................................................................................................................
67 5.3
Sensitivity
to
Parameters
............................................................................................................
69 5.3.1
Decay
Factor
d
............................................................................................................................................
70 5.3.2
Capacity
Size
m
...........................................................................................................................................
72 5.4
Effect
of
Capacity-‐first
Maximum
Flow
...................................................................................
74 5.4.1
Small
Dataset
Comparisons
..................................................................................................................
74 5.4.2
Large
Dataset
Comparison
....................................................................................................................
78 5.5
Comparison
with
Other
Methods
.............................................................................................
84 5.5.1
Comparison
for
Small
Dataset
.............................................................................................................
84 5.5.2
Comparison
for
large
dataset
..............................................................................................................
89 Chapter 6 Conclusion and Future Work
....................................................................
94