14672206
Using marker-based deformable models for deriving anatomical models from medical image databases
The outcome of the application of a deformable model is dependent on its initialization and parameter settings. This is an obstacle to robust automatic segmentation. An approach to reducing the dependences is proposed in this paper based on geodesic topographic distance transforms from two manually or automatically placed markers. This is a novel method that uses object and background differentiation in deformable models via watershed theories. The implementation is based on efficient numerical methods. Experiments have shown that it is a highly promising approach. This approach has been applied to the determination of tissue characteristics in early childhood using a CT database of neonates. We believe that by relaxing dependences on the initialization and parameters this approach will enable a degree of automation needed for segmentation-based construction of organ models from large image databases, particularly when the markers can be determined automatically on the basis of a priori knowledge
12450253
Towards a Visual Programming Environment Based on ITK for Medical Image Analysis
Medical image analysis experiments usually require a certain level of programming skills and are often time-consuming. Visual programming can address these issues by providing a high-level user interface to visually access and combine underlying medical image analysis functionalities. This paper describes the ITKBoard, an extension of the Insight Toolkit for Registration and Segmentation (ITK). Unlike traditional approaches, ITKBoard, a visual tool for experimentation and prototyping, allows rapid visual construction of filter pipelines, via a graphical user interface. An overview of the main functionalities and the system design is presented in this paper. The approaches that we have developed to resolving critical issues such as pipeline handling, automatic object wrapping and plugin mechanism are discussed in detail. This is a first step towards a visual programming environment designed for medical image analysis, in which the specific needs in terms of visual data-flow and control-flow programming will be progressively addressed. It is envisaged that when the software is released in the near future it will be significantly beneficial to the medical image analysis community.
27287493
Integration of multidimensional geospatial information for coastal management and decision-making
Coastal management and decision-making requires timely and accurate multidimensional geospatial data that often reside in government agencies, organizations, and institutions on various levels. Integration of such data involves research on the spatial and temporal characteristics of coastal geospatial information, interoperability of spatial databases and tools, and distributed and mobile technologies. This demonstration will present a system we have developed in last four years, which aims at integrating multidimensional coastal spatial data and information technology to enhance the operational capabilities of federal, state, and local agencies responsible for coastal management and decision making.
39352664
Multi-source Coastal Data Analysis
This paper presents results from the second year of a project on coastal management and decision making sponsored by the National Science Foundation Digital Government Program and carried out by a multidisciplinary research team. As one of the primary goals of the project, tide-coordinated shoreline modeling and mapping requires the integration of multi-source spatio-temporal data that include high-resolution digital elevation models (DEM) derived from IKONOS satellite images and aerial photographs, bathymetric data, water gauge data, satellite altimetric data, and water surfaces derived by a hydrodynamic hindcast model (Li et al., 2002b). Quality and accuracy assessment of these data has been made to ensure reliability of the outcomes of the data integration. The resulting shorelines derived from the integrated data are then evaluated for accuracy in comparison with traditional shorelines determined from tide-coordinated aerial surveys.
6775901
Hamiltonicity of 3-connected quasi-claw-free graphs
A graph G is called quasi-claw-free if it satisfies the property: d(x,y)[email protected]? there exists [email protected]?N(x)@?N(y) such that N[u]@?N[x]@?N[y]. Let G be a 3-connected quasi-claw-free graph of order n. If @d(G)>=(n+5)/5, then G is hamiltonian.
11775748
Schema Mapping for Interoperability in XML-based multidatabase
The main aim of a multidatabase system (MDBS) is to achieve data integration and interoperability among distributed and heterogeneous database systems. But data model heterogeneity and schema make this a challenging task. Multidatabase users can only view the global schemas whose real data come from local database systems. Thus, mappings from global schemas to local schemas should be established. At the same time, the recent emergence of XML has shown great intractability as a new standard for data representation and exchange on the Web. A data model based on XML becomes more suitable for integrating different types of systems. This paper firstly introduces a multidatabase common data model based on XML, named XML-based Integration Model (XIDM). Then, an approach of schema mappings based on XIDM in MDBSs has been presented. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama are also discussed.
7717414
A time interval based consistency control algorithm for interactive groupware applications
Traditional concurrency control methods such as locking and serialization are not suitable for distributed interactive applications that demand fast local response. Operational transformation (OT) is the standard solution to concurrency control and consistency maintenance in group editors, an important class of interactive groupware applications. It generally trades consistency for local responsiveness, because human users can often tolerate temporary inconsistencies but do not like their interactions be lost or nondeterministically blocked. This paper presents a time interval based operational transformation algorithm (TIBOT) that overcomes the various limitations of previous related work. Our approach guarantees content convergence and is significantly more simple and efficient than existing approaches. This is achieved in a pure replicated architecture by using a linear clock and by posing some constraints on communication that are reasonable for the application domain.