Keynote -- Exploring Extremism and Terrorism on the Web: The Dark Web Project -- Long Papers -- Analyzing and Visualizing Gray Web Forum Structure -- An Empirical Analysis of Online Gaming Crime Characteristics from 2002 to 2004 -- Detecting Cyber Security Threats in Weblogs Using Probabilistic Models -- What-if Emergency Management System: A Generalized Voronoi Diagram Approach -- Agent Based Framework for Emergency Rescue and Assistance Planning -- Object Tracking with Self-updating Tracking Window -- A Case-Based Evolutionary Group Decision Support Method for Emergency Response -- Lightweight Anomaly Intrusion Detection in Wireless Sensor Networks -- ASITL: Adaptive Secure Interoperation Using Trust-Level -- A RT0-Based Compliance Checker Model for Automated Trust Negotiation -- TCM-KNN Algorithm for Supervised Network Intrusion Detection -- Research on Hidden Markov Model for System Call Anomaly Detection -- Towards Identifying True Threat from Network Security Data -- Security Assessment for Application Network Services Using Fault Injection -- A Secure Data Transmission Protocol for Mobile Ad Hoc Networks -- Defending DDoS Attacks Using Hidden Markov Models and Cooperative Reinforcement Learning -- A Novel Relational Database Watermarking Algorithm -- Short Papers -- Anticipatory Event Detection for Bursty Events -- Community Detection in Scale-Free Networks Based on Hypergraph Model -- The Treelike Assembly Classifier for Pedestrian Detection -- A Proposed Data Mining Approach for Internet Auction Fraud Detection -- Trends in Computer Crime and Cybercrime Research During the Period 1974-2006: A Bibliometric Approach -- The Study of Government Website Information Disclosure in Taiwan -- Informed Recognition in Software Watermarking -- An Inference Control Algorithm for RDF(S) Repository -- PPIDS: Privacy Preserving Intrusion Detection System -- Evaluating the Disaster Defense Ability of Information Systems -- Airline Safety Evaluation Based on Fuzzy TOPSIS -- A Framework for Proving the Security of Data Transmission Protocols in Sensor Network -- Port and Address Hopping for Active Cyber-Defense -- A Hybrid Model for Worm Simulations in a Large Network -- Posters -- A Web Portal for Terrorism Activities in China -- An Overview of Telemarketing Fraud Problems and Countermeasures in Taiwan -- Mining the Core Member of Terrorist Crime Group Based on Social Network Analysis -- Providing Personalized Services for HWME System by Item-Based Collaborative Filtering -- An Intelligent Agent-Oriented System for Integrating Network Security Devices and Handling Large Amount of Security Events -- Link Analysis-Based Detection of Anomalous Communication Patterns -- Social Modeling and Reasoning for Security Informatics -- Detecting Botnets by Analyzing DNS Traffic -- HMM-Based Approach for Evaluating Risk Propagation -- A Symptom-Based Taxonomy for an Early Detection of Network Attacks.

Intelligence and security informatics (ISI) is concerned with the study of the development and use of advanced information technologies and systems for national, international, and societal security-related applications. The annual IEEE International Conference series on ISI was started in 2003 and the first four meetings were held in the United States. In 2006, the Workshop on ISI (http://isi. se. cuhk. edu. hk/2006/) was held in Singapore in conjunction with the Pacific Asia Conference on Knowledge Discovery and Data Mining, with over 100 contributors and participants from all over the world. These past ISI conferences have brought together academic researchers, law enforcement and intelligence experts, information technology consultants, and practitioners to discuss their research and practice related to various ISI topics including ISI data management, data and text mining for ISI applications, terrorism informatics, deception and intent detection, terrorist and criminal social network analysis, public health and bio-security, crime analysis, cyber-infrastructure protection, transportation infrastructure security, policy studies and evaluation, and information assurance, among others. We continued this stream of ISI conferences by organizing the 2007 Pacific Asia Workshop on ISI (PAISI 2007) to especially provide a stimulating forum for ISI researchers in Pacific Asia and other regions of the world to exchange ideas and report research progress. PAISI 2007 was hosted by the Chinese Academy of Sciences, the University of Arizona, and the Chinese University of Hong Kong.