Dash: A Novel Search Engine for Database-Generated Dynamic Web Pages

Office of Research, Singapore Management Universit

Optimizing the Replication of Multi-Quality Web Applications Using ACO and WoLF

This thesis presents the adaptation of Ant Colony Optimization to a new NP-hard problem involving the replication of multi-quality database-driven web applications (DAs) by a large application service provider (ASP). The ASP must assign DA replicas to its network of heterogeneous servers so that user demand is satisfied and replica update loads are minimized. The algorithm proposed, AntDA, for solving this problem is novel in several respects: ants traverse a bipartite graph in both directions as they construct solutions, pheromone is used for traversing from one side of the bipartite graph to the other and back again, heuristic edge values change as ants construct solutions, and ants may sometimes produce infeasible solutions. Experiments show that AntDA outperforms several other solution methods, but there was room for improvement in the convergence rates of the ants. Therefore, in an attempt to achieve the goals of faster convergence and better solution values for larger problems, AntDA was combined with the variable-step policy hill-climbing algorithm called Win or Learn Fast (WoLF). In experimentation, the addition of this learning algorithm in AntDA provided for faster convergence while outperforming other solution methods

EdgeX: Edge Replication for Web Applications

Global web applications face the problem of high network latency due to their need to communicate with distant data centers. Many applications use edge networks for caching images, CSS, javascript, and other static content in order to avoid some of this network latency. However, for updates and for anything other than static content, communication with the data center is still required, and can dominate application request latencies. One way to address this problem is to push more of the web application, as well the database on which it depends, from the remote data center towards the edge of the network. This thesis presents preliminary work in this direction. Speci cally, it presents an edge-aware dynamic data replication architecture for relational database systems supporting web applications. The objective is to allow dynamic content to be served from the edge of the network, with low latency

Towards Efficient Delivery of Dynamic Web Content

Advantages of cache cooperation on edge cache networks serving dynamic web content were studied. Design of cooperative edge cache grid a large-scale cooperative edge cache network for delivering highly dynamic web content with varying server update frequencies was presented. A cache clouds-based architecture was proposed to promote low-cost cache cooperation in cooperative edge cache grid. An Internet landmarks-based scheme, called selective landmarks-based server-distance sensitive clustering scheme, for grouping edge caches into cooperative clouds was presented. Dynamic hashing technique for efficient, load-balanced, and reliable documents lookups and updates was presented. Utility-based scheme for cooperative document placement in cache clouds was proposed. The proposed architecture and techniques were evaluated through trace-based simulations using both real-world and synthetic traces. Results showed that the proposed techniques provide significant performance benefits. A framework for automatically detecting cache-effective fragments in dynamic web pages was presented. Two types of fragments in web pages, namely, shared fragments and lifetime-personalization fragments were identified and formally defined. A hierarchical fragment-aware web page model called the augmented-fragment tree model was proposed. An efficient algorithm to detect maximal fragments that are shared among multiple documents was proposed. A practical algorithm for detecting fragments based on their lifetime and personalization characteristics was designed. The proposed framework and algorithms were evaluated through experiments on real web sites. The effect of adopting the detected fragments on web-caches and origin-servers is experimentally studied.Ph.D.Committee Chair: Dr. Ling Liu; Committee Member: Dr. Arun Iyengar; Committee Member: Dr. Calton Pu; Committee Member: Dr. H. Venkateswaran; Committee Member: Dr. Mustaque Ahama

Internet of Things From Hype to Reality

The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions

Optimized and Automated Machine Learning Techniques Towards IoT Data Analytics and Cybersecurity

The Internet-of-Things (IoT) systems have emerged as a prevalent technology in our daily lives. With the wide spread of sensors and smart devices in recent years, the data generation volume and speed of IoT systems have increased dramatically. In most IoT systems, massive volumes of data must be processed, transformed, and analyzed on a frequent basis to enable various IoT services and functionalities. Machine Learning (ML) approaches have shown their capacity for IoT data analytics. However, applying ML models to IoT data analytics tasks still faces many difficulties and challenges. The first challenge is to process large amounts of dynamic IoT data to make accurate and informed decisions. The second challenge is to automate and optimize the data analytics process. The third challenge is to protect IoT devices and systems against various cyber threats and attacks. To address the IoT data analytics challenges, this thesis proposes various ML-based frameworks and data analytics approaches in several applications. Specifically, the first part of the thesis provides a comprehensive review of applying Automated Machine Learning (AutoML) techniques to IoT data analytics tasks. It discusses all procedures of the general ML pipeline. The second part of the thesis proposes several supervised ML-based novel Intrusion Detection Systems (IDSs) to improve the security of the Internet of Vehicles (IoV) systems and connected vehicles. Optimization techniques are used to obtain optimized ML models with high attack detection accuracy. The third part of the thesis developed unsupervised ML algorithms to identify network anomalies and malicious network entities (e.g., attacker IPs, compromised machines, and polluted files/content) to protect Content Delivery Networks (CDNs) from service targeting attacks, including distributed denial of service and cache pollution attacks. The proposed framework is evaluated on real-world CDN access log data to illustrate its effectiveness. The fourth part of the thesis proposes adaptive online learning algorithms for addressing concept drift issues (i.e., data distribution changes) and effectively handling dynamic IoT data streams in order to provide reliable IoT services. The development of drift adaptive learning methods can effectively adapt to data distribution changes and avoid data analytics model performance degradation

Crises and opportunities : strengthened European Union economic governance after the 2008 financial crisis

This dissertation uses three major European integration theories __ neo-functionalism, liberal intergovernmentalism and historical institutionalism __ to analyze the European Union__s (EU__s) new developments during the post-2008 crisis era, particularly during the euro area sovereign debt crisis, with the purpose to grasp the developing trends of EU economic governance after 2008. Using congruence testing and process-tracing, hypotheses deducted from the three theories are tested by three selected cases of recent EU developments: the European Semester, the European Systemic Risk Board and the European Stability Mechanism. The acceptance, rejection or revision of the hypotheses makes a possible contribution to the ever developing European integration theories, and moreover, hypothesis test results provide answers to the main and sub research questions. The research shows that the crisis is also an opportunity for the EU to develop and mature, and EU economic governance has been strengthened after the 2008 global financial crisis. To address collective issues and challenges from holistic approaches is a tendency of EU economic governance in the future, which, tending to cut across different policy areas, requires effective communication, coordination and cooperation among various actors within the EU so as to bring about maximal synergistic effects of individual parts.UBL - phd migration 201