17720018
Conformal deskewing of non-planar documents
This paper presents an approach that uses conformal mapping to parameterize a document's 3D shape to a 2D plane. Using this conformal parametrization, a restorative mapping between an image of the distorted document and a "flattened" representation of the document can be computed and used to deskew the image. Our experiments show that arbitrarily distorted documents can be restored to within a single pixel of their true planar format. In addition, surface points can be constrained to map to specified locations in the restored 2D plane.
6609870
Building large-format displays for digital libraries
COMMUNICATIONS OF THE ACM May 2001/Vol. 44, No. 5 57 Digital libraries house media of ever-increasing complexity, from models of statues to virtual archeological landscapes. Future digital archives will only increase in resolution and complexity as acquisition hardware improves and data becomes more intricate. Although digital content is constantly improving, the typical display device (the desktop monitor) remains relatively unchanged. The problem is the spatial resolution and color quality of digital media surpasses the display real estate of typical monitors. It is common for objects such as artwork and manuscripts to be digitized at a much higher resolution than can be displayed on even the best monitors. This forces the data to be down-sampled, or restricts viewing to selected regions of interest at a time. Even with improved resolution, small display areas are often less than compelling. For example, the high-resolution facsimile of Michelangelo’s 17-foot statue of David [4] is somewhat less spectacular when displayed on a high-resolution 20-inch monitor. The simple fact is monitors have become under-powered technologies for the visualization capabilities now needed to fully appreciate digital archives. The immediate reaction is to enlist the help of large-format displays for visualization available as video walls, domes, and immersive environments such as the CAVE. These environments provide a compelling sense of presence and help break the “window on worlds” paradigm. Unfortunately, these technologies also present serious challenges that limit their accessibility and usefulness to a small number of institutions. Of primary concern is the cost. Initial costs of projectors, rendering hardware, and subsequent recurring operational expenses are fiscally prohibitive. A second concern is the renovation necessary for installing a large-format display system. Because most systems rely on mechanically aligned projectors and rigidly constructed display surfaces, room modification and projection surface infrastructure are necessary. An additional difficulty is the complexity of continuous operation. These systems are not for novice users and can quickly become unusable without expert maintenance and tuning. Our goal is to bring large-format displays to the digital library community by breaking down the barriers that make them expensive and difficult to set up and run. We are attacking the price/performance barrier by engineering displays built entirely from commodity components and assembled in a scalable configuration. Specifically, commodity light projectors, unlike monitors, can be positioned collectively to form a single logical desktop (see Figure 1). Inexpensive video cards can perform at the level required to drive a projector. Groups of PCs, each driving a projector and communicating via a local area network, are inexpensive and powerful [2, 6]. While the physical alignment of projectors creates a very compelling display, it is tedious and requires major effort. Within the digital library community, where libraries must operate and maintain equipment, it is important to enable novice technicians to build up and maintain a display by a more casual placement of projectors. Michael S. Brown, W. Brent Seales, Stephen B. Webb, and Christopher O. Jaynes { {
1418505
Small Subunit Ribosomal RNA Modeling Using Stochastic Context-Free Grammars
We introduce a model based on stochastic context-free grammars (SCFGs) that can construct small subunit ribosomal RNA (SSU rRNA) multiple alignments. The method takes into account both primary sequence and secondary structure basepairing interactions. We show that this method produces multiple alignments of quality close to hand edited ones and outperforms several other methods. We also introduce a method of SCFG constraints that dramatically reduces the required computer resources needed to effectively use SCFGs on large problems such as SSU rRNA. Without such constraints, the required computer resources are infeasible for most computers. This work has applications to fields such as phylogenetic tree construction.
12258232
Building IT Competence in Line Management: Investigation of a Best Practice
RESEARCH QUESTION During a prior research study, the first author interviewed the Vice President of IS for Common ]nsurance Group, one of the largest life insurance companies in Canada. She learned that the company had transferred more than forty information systems (IS) people into various management jobs throughout its insurance divisions during the twelve years from 1980 to 1992. Permission to conduct an in-depth study of this unusual IS-to-line project was granted to the researchers in 1993. Our interest in investigating this org ization was to find answers to three questions: 1. What organizational factors (e.g., structures, incentives, training) made it possible for Common Insurance Group to move IS maimgers into line positions with regularity for over a decade? 2. What individual factors affected the ease with which these IS-trained people made the transition into line positions? 3. Within Common Insurance Group, what are the results of having many business unit managers with extensive IS experience? RESEARCH DESIGN The study will investigate the research questions at two levels, organizational and individual. There are three stages in the research: 1) initial interviews with ex-IS managers, 2) a matched survey of non-IS managers, ex-IS managers and current IS managers, and 3) follow-up interviews with selected managers. Our exploratory research model suggests that Organizational Factors, Individual Factors, Job-Related Factors and Transition Factors influence the movement of an IS manager to a line management job. Further, movement of IS people into the line will have both organizational and individual results. SUMMARY Our hope is that, at the end of this research project, we will understand clearly how Common Insurance Group accomplished a very uncommon feat. The revised model will create a solid foundation for further research and the set of anec(total cases will assist other organizations in creating programs to increase IT competence in their line areas.
37211415
A Hypertext for Literate Programming
In this paper we describe a hypertext presentation for the WEB system for literate programming. The requirements for an environment for modern literate programming are analyzed and the WEB hypertext system is proposed. Different types of windows for displaying text, indices and graphical representations are discussed. All semantic links and operators using them are analyzed. The proposed architecture of the WEB hypertext system includes a general purpose relational database management system. Mapping between hypertext queries and relational database queries is provided. The system allows the user to define new hypertext operations by providing the corresponding SQL queries for the underlying relational database. The described system can be easily extended by many other types of queries and applications.
11872886
Software visualization
From the Publisher: 
In the past decade, high-quality interfaces have become standard in a growing number of areas such as games and CD-ROM-based encyclopedias. Yet the overwhelming majority of programmers edit their code using a single font within a single window and view code execution via the hand insertion of print statements. Software Visualization (SV) redresses this imbalance by using typography, graphics, and animation techniques to show program code, data, and control flow. This book describes the history of SV, techniques and frameworks for its construction, its use in education and program debugging, and recent attempts to evaluate its effectiveness. In making programming a multimedia experience, SV leaves programmers and computer science researchers free to explore more interesting issues and to tackle more challenging problems.
12045621
Visualization of the Interaction of Multiple Sclerosis Lesions with Adjacent White Matter Fibers Using Streamtubes and Streamsurfaces
Multiple sclerosis (MS) is a chronic disease of the central nervous system that predominantly affects young adults during their most productive years. Pathologically, MS is characterized by the presence of areas of demyelination and T-cell predominant perivascular inflammation in the brain white matter. In order to study the effect of MS lesion on the white matter, we acquire diffusion tensor imaging (DTI) data on MS patients and employ streamtubes and streamsurfaces to visualize the DTI data. We also register structural data sets with DTI data sets and generate isosurfaces of the MS lesions and the ventricles. The simultaneous visualization of all the models has the potential to elucidate the complex relationship between the MS lesions, the white matter neural fibers and the affected gray matter regions.