Suen, Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 99-104). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Organization --- p.4 / Chapter 2 --- Literature Review --- p.6 / Chapter 2.1 --- Related Works --- p.6 / Chapter 2.2 --- Background Study --- p.7 / Chapter 2.2.1 --- World Wide Web --- p.7 / Chapter 2.2.2 --- Distributed Denial of Service Attack --- p.11 / Chapter 2.2.3 --- Tools for Dimension Reduction --- p.13 / Chapter 2.2.4 --- Tools for Anomaly Detection --- p.20 / Chapter 2.2.5 --- Receiver operating characteristics (ROC) Analysis --- p.22 / Chapter 3 --- System Design --- p.25 / Chapter 3.1 --- Methodology --- p.25 / Chapter 3.2 --- System Overview --- p.27 / Chapter 3.3 --- Reference Profile Construction --- p.31 / Chapter 3.4 --- Real-time Anomaly Detection and Response --- p.32 / Chapter 3.5 --- Chapter Summary --- p.34 / Chapter 4 --- Reference Profile Construction --- p.35 / Chapter 4.1 --- Web Access Logs Collection --- p.35 / Chapter 4.2 --- Data Preparation --- p.37 / Chapter 4.3 --- Feature Extraction and Embedding Engine (FEE Engine) --- p.40 / Chapter 4.3.1 --- Sub-Sequence Extraction --- p.42 / Chapter 4.3.2 --- Hash Function on Sub-sequences (optional) --- p.45 / Chapter 4.3.3 --- Feature Vector Construction --- p.46 / Chapter 4.3.4 --- Diffusion Wavelets Embedding --- p.47 / Chapter 4.3.5 --- Numerical Example of Feature Set Reduction --- p.49 / Chapter 4.3.6 --- Reference Profile and Further Use of FEE Engine --- p.50 / Chapter 4.4 --- Chapter Summary --- p.50 / Chapter 5 --- Real-time Anomaly Detection and Response --- p.52 / Chapter 5.1 --- Session Filtering and Data Preparation --- p.54 / Chapter 5.2 --- Feature Extraction and Embedding --- p.54 / Chapter 5.3 --- Distance-based Outlier Scores Calculation --- p.55 / Chapter 5.4 --- Anomaly Detection and Response --- p.56 / Chapter 5.4.1 --- Length-Based Anomaly Detection Modules --- p.56 / Chapter 5.4.2 --- Characteristics of Anomaly Detection Modules --- p.59 / Chapter 5.4.3 --- Dynamic Threshold Adaptation --- p.60 / Chapter 5.5 --- Chapter Summary --- p.63 / Chapter 6 --- Experimental Results --- p.65 / Chapter 6.1 --- Experiment Datasets --- p.65 / Chapter 6.1.1 --- Normal Web Access Logs --- p.66 / Chapter 6.1.2 --- Attack Data Generation --- p.68 / Chapter 6.2 --- ROC Curve Construction --- p.70 / Chapter 6.3 --- System Parameters Selection --- p.71 / Chapter 6.4 --- Performance of Anomaly Detection --- p.82 / Chapter 6.4.1 --- Performance Analysis --- p.85 / Chapter 6.4.2 --- Performance in defending DDoS attacks --- p.87 / Chapter 6.5 --- Computation Requirement --- p.91 / Chapter 6.6 --- Chapter Summary --- p.95 / Chapter 7 --- Conclusion and Future Work --- p.96 / Bibliography --- p.99

Wang, Wei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 106-122). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgement --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Thesis Contributions --- p.5 / Chapter 1.3 --- Thesis Organization --- p.8 / Chapter 2 --- Background and Literature Review --- p.9 / Chapter 2.1 --- Label Ranking in Machine Learning --- p.11 / Chapter 2.1.1 --- Label Ranking --- p.11 / Chapter 2.1.2 --- Semi-Supervised Learning --- p.12 / Chapter 2.1.3 --- The Development of Label Ranking --- p.14 / Chapter 2.2 --- Question Retrieval in Community Question Answering --- p.16 / Chapter 2.2.1 --- Question Retrieval --- p.16 / Chapter 2.2.2 --- Basic Question Retrieval Models --- p.18 / Chapter 2.2.3 --- The Development of Question Retrieval Models --- p.21 / Chapter 2.3 --- Ranking through CTR by Building Click Models --- p.24 / Chapter 2.3.1 --- Click Model's Importance --- p.24 / Chapter 2.3.2 --- A Simple Example of Click Model --- p.25 / Chapter 2.3.3 --- The Development of Click Models --- p.27 / Chapter 3 --- Semi-Supervised Label Ranking --- p.30 / Chapter 3.1 --- Motivation: The Limitations of Supervised Label Ranking --- p.30 / Chapter 3.2 --- Label Ranking and Semi-Supervised Learning Framework --- p.32 / Chapter 3.2.1 --- Label Ranking and Semi-Supervised Learning Setup --- p.32 / Chapter 3.2.2 --- Information Gain Decision Tree for Label Ranking --- p.37 / Chapter 3.2.3 --- Instance Based Label Ranking --- p.39 / Chapter 3.2.4 --- Mallows Model Decision Tree for Label Ranking --- p.40 / Chapter 3.3 --- Experiments --- p.40 / Chapter 3.3.1 --- Dataset Description --- p.41 / Chapter 3.3.2 --- Experimental Results --- p.42 / Chapter 3.3.3 --- Discussion --- p.42 / Chapter 3.4 --- Summary --- p.44 / Chapter 4 --- An Application of Label Ranking --- p.45 / Chapter 4.1 --- Motivation: The Limitations of Traditional Question Retrieval --- p.45 / Chapter 4.2 --- Intention Detection Using Label Ranking --- p.47 / Chapter 4.2.1 --- Question Intention Detection --- p.48 / Chapter 4.2.2 --- Label Ranking Algorithms --- p.50 / Chapter 4.2.3 --- Some Other Learning Algorithms --- p.53 / Chapter 4.3 --- Improved Question Retrieval Using Label Ranking --- p.54 / Chapter 4.3.1 --- Question Retrieval Models --- p.55 / Chapter 4.3.2 --- Improved Question Retrieval Model --- p.55 / Chapter 4.4 --- Experimental Setup --- p.56 / Chapter 4.4.1 --- Experiment Objective --- p.56 / Chapter 4.4.2 --- Experiment Design --- p.56 / Chapter 4.4.3 --- DataSet Description --- p.57 / Chapter 4.4.4 --- Question Feature --- p.59 / Chapter 4.5 --- Experiment Result and Comments --- p.60 / Chapter 4.5.1 --- Question Classification --- p.60 / Chapter 4.5.2 --- Classification Enhanced Question Retrieval --- p.63 / Chapter 4.6 --- Summary --- p.69 / Chapter 5 --- Ranking by CTR in Click Models --- p.71 / Chapter 5.1 --- Motivation: The Relational Influence's Importance in Click Models --- p.71 / Chapter 5.2 --- Click Models in Sponsored Search --- p.75 / Chapter 5.2.1 --- A Brief Review on Click Models --- p.76 / Chapter 5.3 --- Collaborating Influence Identification from Data Analysis --- p.77 / Chapter 5.3.1 --- Quantity Analysis --- p.77 / Chapter 5.3.2 --- Psychology Interpretation --- p.82 / Chapter 5.3.3 --- Applications Being Influenced --- p.82 / Chapter 5.4 --- Incorporating Collaborating Influence into CCM . --- p.83 / Chapter 5.4.1 --- Dependency Analysis of CCM --- p.83 / Chapter 5.4.2 --- Extended CCM --- p.84 / Chapter 5.4.3 --- Algorithms --- p.85 / Chapter 5.5 --- Incorporating Collaborating Influence into TCM . --- p.87 / Chapter 5.5.1 --- TCM --- p.87 / Chapter 5.5.2 --- Extended TCM --- p.88 / Chapter 5.5.3 --- Algorithms --- p.88 / Chapter 5.6 --- Experiment --- p.90 / Chapter 5.6.1 --- Dataset Description --- p.90 / Chapter 5.6.2 --- Experimental Setup --- p.91 / Chapter 5.6.3 --- Evaluation Metrics --- p.91 / Chapter 5.6.4 --- Baselines --- p.92 / Chapter 5.6.5 --- Performance on RMS --- p.92 / Chapter 5.6.6 --- Performance on Click Perplexity --- p.93 / Chapter 5.6.7 --- Performance on Log-Likelihood --- p.93 / Chapter 5.6.8 --- Significance Discussion --- p.98 / Chapter 5.6.9 --- Sensitivity Analysis --- p.98 / Chapter 5.7 --- Summary --- p.102 / Chapter 6 --- Conclusion and Future Work --- p.103 / Chapter 6.1 --- Conclusion --- p.103 / Chapter 6.2 --- Future Work --- p.105 / Bibliography --- p.106