Xue Dong Yang

The Cluster Hair Model

Modeling and rendering human hair is a very challenging problem in computer graphics. The difficulty comes mainly from the amount of hair to be modeled and the fine shapes of the individual hairs. In this paper, a new cluster hair model is introduced. The new model allows the design and styling of hair to be efficiently performed at the abstract cluster level. The key idea of this work is to embed a volume density model into a generalized cylinder, which is used to specify the envelope shape of a hair cluster, so that the design and manipulation of hair can be globally and efficiently performed. The detail of the hair is then modeled by a volume density model in which a randomly generated density map on the hair base is projected into and deformed along the generalized cylinder. The main advantages of the new model are: (1) it provides a very compact and efficient representation for complex hair styles; (2) it improves significantly the feasibility of and capability for interactive hair modeling and styling; (3) it produces high quality hair images; and (4) it provides a multiresolution model for adaptive rendering. It also has the potential to support efficient dynamic simulation at the cluster level.

The Visual Exploration ofWeb Search Results Using HotMap

While the information retrieval techniques used by Web search engines have improved substantially over the years, the search results have continued to be represented in a simple list-based format. Although this list-based representation makes it easy to evaluate a single document, it does not support the users in the broader tasks of manipulating the search results, comparing documents, or finding a set of relevant documents. HotMap provides a compact visual representation of Web search results at two levels of detail, and supports the interactive exploration of Web search results. User studies have shown that HotMap can result in fewer low-relevance documents being considered, and generates a higher level of confidence, ease of use, and satisfaction than a Google-like interface

Interactive Web Information Retrieval Using WordBars

It is common for Web searchers to have difficulties crafting queries to fulfil their information needs. Even when they provide a good query, users often find it challenging to evaluate the results of their Web searches. Sources of these problems include the lack of support for query refinement, and the static nature of the list-based representations of Web search results. To address these issues, we have developed WordBars, an interactive tool for Web information retrieval. WordBars visually represents the frequencies of the terms found in the first 100 document surrogates returned from the initial query. This system allows the users to interactively re-sort the search results based on the frequencies of the selected terms within the document surrogates, as well as to add and remove terms from the query, generating a new set of search results. Examples illustrate how WordBars can provide valuable support for query refinement and search results exploration, both when specific and vague initial queries are provided

Existing and emerging image quality metrics

This paper summarizes and evaluates some of the existing methods of measuring and quantifying the quality of a digital image. Unfortunately, no general method has been found. The performance of a quality metric is normally gauged by its prediction accuracy, monotonicity and consistency. It is also expected to mirror the quality scores assigned by independent human observers. Research to this point has generally focused on full-reference (FR) measures that assume that coded and original images are available. Often times, an original is not easily obtainable, or perhaps does not even exist. Therefore, researchers have recently shown a great deal of interest in developing reduced-reference (RR) and no-reference (NR) metrics. This study implements and compares some of the most common IQMs and seeks to determine if there is any difference in their performance. Analysis of the results focuses on determining if any IQM is superior to the others over a general set of test images

Visualization Support for Interactive Query Refinement

It has been well documented that Web searchers have difficulties crafting queries to fulfill their information needs. In this work, we use a concept knowledge base generated from the ACM computing classification system to generate a query space that represents the query terms in relation to the concepts they describe and the other terms that are related to these concepts. A visual representation of this query space allows the user to interpret the relationships between their query terms and the query space. Interactive query refinement within this visual representation takes advantage of the users visual information processing abilities, and allows the user to choose terms that accurately represent their information need. A preview of the search results from Google provides the user with an indication of the current state of their query refinement process. This work allows the user to take an active role in the information retrieval process, supporting the fundamental shift from information retrieval systems to information retrieval support systems.

Evaluating WordBars in exploratory Web search scenarios

Web searchers commonly have difficulties crafting queries to fulfill their information needs; even after they are able to craft a query, they often find it challenging to evaluate the results of their Web searches. Sources of these problems include the lack of support for constructing and refining queries, and the static nature of the list-based representations of Web search results. WordBars has been developed to assist users in their Web search and exploration tasks. This system provides a visual representation of the frequencies of the terms found in the first 100 document surrogates returned from an initial query, in the form of a histogram. Exploration of the search results is supported through term selection in the histogram, resulting in a re-sorting of the search results based on the use of the selected terms in the document surrogates. Terms from the histogram can be easily added or removed from the query, generating a new set of search results. Examples illustrate how WordBars can provide valuable support for query refinement and search results exploration, both when vague and specific initial queries are provided. User evaluations with both expert and intermediate Web searchers illustrate the benefits of the interactive exploration features of WordBars in terms of effectiveness as well as subjective measures. Although differences were found in the demographics of these two user groups, both were able to benefit from the features of WordBars.

A Comparative User Study of Web Search Interfaces: HotMap, Concept Highlighter, and Google

Users of traditional Web search engines commonly find it difficult to evaluate the results of their Web searches. We suggest the use of information visualization and interactive visual manipulation as methods for improving the ability of users to evaluate the results of a Web search. In this paper, we present the results of a user study that compared the search results interface provided by Google to that of two systems we have developed: HotMap and Concept Highlighter. We found that users were able to perform their searches faster with HotMap, were able to find more relevant documents with Concept Highlighter, and generally ranked these interfaces higher than Google with respect to subjective measures. When given a choice between these interfaces, participants ranked HotMap the highest, followed by Google and Concept Highlighter. These results indicate that even though the list-based representation of search results are common among search engines, visual and interactive interfaces to Web search results can be more efficient, effective, and satisfying to the users

Conceptual query expansion

Query expansion has been extensively studied as a technique for increasing information retrieval performance. However, due to the volume of documents available on the web, many of the techniques that have been successful in traditional information retrieval systems do not scale well to web information retrieval. We propose a new technique based on conceptual semantic theories, in contrast to the structuralist semantic theories upon which other techniques are based. The source of the query expansion information is the concept network knowledge base. Query terms are matched to those contained in the concept network, from which concepts are deduced and additional query terms are selected. In this paper, we describe the theoretical basis for this in-progress research, along with some preliminary results.

User-Oriented Evaluation Methods for Interactive Web Search Interfaces

Although significant efforts have been devoted to the study and evaluation of information retrieval systems from an algorithmic perspective, far less work has been performed on the evaluation of these systems from the users perspective. This is certainly the case for Web information retrieval, where the major search engines continue to utilise interfaces that have not changed substantially since their introduction. One of the challenges in developing new Web search interfaces is the evaluation of these systems in comparison to one another, as well as in comparison to the popular Web search engines. In this paper, we highlight some of the methods used in the literature for evaluating Web search systems, and present a summary of the methods that we have found to be effective in dealing with the challenges of evaluating intelligent and interactive Web search interfaces.

A facial presence monitoring system for information security

Information security requires a method to establish digital credentials that can reliably identify individual users. Since biometrics is concerned with the measurements of unique human physiological or behavioural characteristics, the technology has been used to verify the identity of computer or network users. Given todays heightened security requirements of military as well as other applications such as banking, health care, etc., it is becoming critical to be able to monitor the presence of the authenticated user throughout a session. This paper presents a prototype system that uses facial recognition technology to monitor the authenticated user. The objective is to ensure that the user who is using the computer is the same person that logged onto the system. A neural network-based algorithm is implemented to carry out face detection, and an eigenface method is employed to perform facial recognition. A graphical user interface (GUI) has been developed which allows the performance of face detection and facial recognition to be monitored at run time. The experimental results demonstrate the feasibility of near-real-time continuous user verification for high-level security information systems.