This book focuses on the risk modeling, analysis and control of multi-energy systems considering cross-sectorial failure propagation. Both models and methods have been addressed with engineering practice. This is accomplished by doing a thorough investigation into the modeling of system physics and reliabilities in both long- and short-term phases. Different models and methods to evaluate the risk of multi-energy systems considering various disturbances, e.g., component failures, load uncertainties and extreme weather, are studied in detail. Furthermore, several risk control strategies for multi-energy systems, such as long-term capacity planning and integrated demand response, are analyzed in this book, which is especially suited for readers interested in system risk management.

Provides a comprehensive guide to FACTS, covering all the major aspects in research and development of FACTS technology.
The rapid development of power electronics technology provides exciting opportunities to develop new power system equipment for better utilisation of existing systems. Deregulation of the supply industry worlwide, and the resulting competition, is forcing utilities to operate their facilities at ever higher efficiency, driving this trend. During the last decade, a number of control devices under the term flexible AC transmission systems (FACTS) technology have been proposed and implemented. This book provides a comprehensive guide to FACTS, covering all the major aspects in research and development of FACTS technologies. Various real-world applications are also included to demonstrate the issues and benefits of applying FACTS. Written by international experts in the field from both industry and academia, this book will be a useful reference for professional engineers involved in the operation and control of modern power systems. It will also be of value to postgraduate students and researchers.

The electric power industry is currently undergoing an unprecedented reform. The deregulation of electricity supply industry has introduced new opportunity for competition to reduce the cost and cut the price. It is a tremendous challenge for utilities to maintain an economical and reliable supply of electricity in such an environment. Faced by an increasingly complicated existence, power utilities need efficient tools and aids to ensure that electrical energy of the desired quality can be provided at the lowest cost. The overall objective, both for short-term and long-term operations, is then to find the best compromise between the requirements of security and economy. That is, effective tools are urgently required to solve highly constrained optimisation problems. In recent years, several major modem optimisation techniques have been applied to power systems. A large number of papers and reports have been published. In this respect, it is timely to edit a book on this topic with an aim to report the state of the art development internationally in this area.

Internationally, the electric power industry is currently undergoing unprecedented reform. Power utilities need efficient tools to ensure that electrical energy of the quality desired can be provided at the lowest possible cost. Operation of Market-oriented Power Systems provides effective computational tools for the efficient operation of restructured power systems covering all the major operational issues such as:
• congestion management;
• available transfer capability calculations;
• price forecasting and optimal bidding strategies;
• a review of international research and world-wide industrial practice covered in each chapter gives the reader a broader understanding of the state of the art in this exciting field.

The book reports on the development and validation of a computerized adaptive EFL test, which is used as an exit requirement for non-English-major undergraduates at a major Chinese university. Unlike the tests reported in previous research on computerized adaptive language test (CALT), which were mostly designed to assess vocabulary, grammar and reading, this test consists of listening and reading components using both dichotomously-scored stand-alone items and polytomously-scored testlet-based items. The book is an essential and stimulating read for researchers and graduate students in the testing domain, particularly for those who are interested in CALT, item response theory (IRT), and quantitative research methods in general. It also constitutes a solid reference resource for L2 teachers and test developers. One of the distinctive features of the book is its operationalization of assessment use argument (AUA) in the investigation of the construct validity of the CALT. Another strength of this book is that it provides insight into the specific procedures that are followed in the development of CALTs and addresses a few key issues, such as local item dependence and DIF detection that were ignored in previous CALT development research.

Direct volume rendering (DVR) is an effective way to visualize 3D vascular images for diagnosis of different vascular pathologies and planning of surgical treatments. Angiograms are typically noisy, fuzzy, and contain thin vessel structures. Therefore, some kinds of enhancements are usually needed before direct volume rendering can start. However, without visualizing the 3D structures in angiograms, users may find it difficult to select appropriate parameters and assess the effectiveness of the enhancement results. In addition, traditional enhancement techniques cannot easily separate the vessel voxels from other contextual structures with the same or very similar intensity. In this paper, we propose a framework to integrate enhancement and direct volume rendering into one visualization pipeline using multi-dimensional transfer function tailored for visualizing the curvilinear and line structures in angiograms. Furthermore, we present a feature preserving interpolation method to render very thin vessels which are usually missed using traditional approaches. To ease the difficulty in vessel selection, a MIP-guided method is suggested to assist the process.

In this paper, we present some novel animation techniques to help users understand complex structures contained in volumetric data from the medical imaging and scientific simulation fields. Because of the occlusion of 3D objects, these complex structures and their 3D relationships usually cannot be revealed using one image. By our animation techniques, the focus regions, the context regions, and their relationships can be better visualized at the different stages of an animation. We propose an image-centric method which employs layered-depth images (LDIs) to get correct depth cues, and a data-centric method which exploits a novel transfer function fusing technique to guarantee the smooth transition between frames. The experimental results on real volume data demonstrate the advantages of our techniques over traditional image blending and transfer function interpolation methods.

In this paper, we present a novel viewpoint selection framework for angiographic volume data. We propose several view descriptors based on typical concerns of clinicians for the view evaluation. Compared with conventional approaches, our method can deliver a more representative global optimal view by sampling at a much higher rate in the view space. Instead of performing analysis on sample views individually, we construct a solution space to estimate the quality of the views. Descriptor values are propagated to the solution space where an efficient searching process can be performed. The best viewpoint can be found by analyzing the accumulated descriptor values in the solution space based on different visualization goals.

Node-link diagrams are widely used in information visualization to show relationships among data. However, when the size of data becomes very large, node-link diagrams will become cluttered and visually confusing for users. In this paper, we propose a novel controllable edge clustering method based on Delaunay triangulation to reduce visual clutter for node-link diagrams. Our method uses curves instead of straight lines to represent links and these curves can be grouped together according to their relative positions and directions. We further introduce progressive edge clustering to achieve continuous level-of-details for large networks.

Hyperlinks among webpages are very important information and are widely used for webpage clustering and webpage ranking. With the explosive growth in the number of webpages available online, the exploration of hyperlinks among webpages becomes a very challenging problem. Information visualization provides an effective way of visualizing hyperlinks and can help users gain insights into the relationships of webpages.

In this paper, we present some novel computer graphics techniques to visualize the hyperlinks among webpages. We propose a visual encoding scheme for five dimensional hyperlinks data and two constrained 3D layout techniques for incoming and outgoing links of a single webpage. To reveal the hierarchical structure of webpages as well as the hyperlinks information, we extend the treemap representation. Our representations are visually appealing and can effectively reveal linkage patterns among webpages. Experimental results and a user study demonstrate the effectiveness of our system. Our system can facilitate E-learning and help students understand the complex structures and hidden patterns in network datasets.