|Program for Research in Computing and Information Sciences and Engineering|
Cardiovascular Geometric Modeling using Image Segmentation
Blood flow modeling applications play an important role in cardiovascular medicine in areas such as disease research, medical device design, and surgical planning. These applications require accurate 3-D geometric models of the vascular structures of interest, since important blood flow phenomena may be incorrectly simulated in the absence of accurate vessel geometries. Geometric image segmentation techniques, such as level methods and active contours, provide powerful ways to improve the accuracy of the vascular models because of their geometric nature. Some characteristics of these techniques make them appealing for use in reconstruction of vascular geometry from imaging data. This study will consist on the application of the level set method and active contours to construct 3-D models of vascular structures using imaging data. Unstructured three-dimensional meshes will be generated from the geometric models of the vascular structures for finite element flow analysis.
A basic problem in computer vision is to develop texture discrimination techniques that perform as well as the human visual system. A theoretical framework that relates dynamics of texture discrimination over context changes with perceptual discrimination is presented. The framework consists of a texture space, a perceptual space and a representational space. Texture stimuli are mapped on to the representational space. A nonlinear psychophysical dynamic transformation is used to map texture stimuli input to responses. This dynamics couples the environment to an internal feedback loop that models the non-linearities in sensory and neural processes of psychovisual perception. The framework can be (1) used to perform texture discrimination that preserves perceptual similarity with the performance of the visual system and also (2) used to study how discriminability of texture pattterns is affected by changes in a particular texture property over time. Using this framework a procedure to model discrimination of textures is presented. The nonlinear psychophysical dynamics are implemented using simple finite difference scheme and can be easily converted to parallel algorithm.
UDP, TCP, and IP Fragmentation Analysis and Its Importance
in TOE devices
This project focuses on ways of handling IP stacks by offloading its protocol scheme inside a TCP/IP Offload Engine (TOE) device. Three different networks environments were analyzed using a TCP/IP offload engine point of view. Internet related protocols were studied in a real environment in order to assign candidates for a real TCP/IP offload engine implementation. The numbers of broadcast and unicast packets received were also analyzed. A formula for calculating the number of wasted interrupts is presented. Also, tasks priorities imperative to implement in a TCP/IP offload device are established. This analysis improves the framework discussed on a previous work.
Development of User Interfaces for Accessing Electronic Patient
Record Systems with hand Held Devices
The Project on Development of User Interfaces for Accessing Electronic Patient Record Systems with Hand Held Devices consists of two parts. This project uses different hand-held devices for the development of user interfaces for Nurses and Physicians. The first part is being implemented by Yajaira Soler and uses an iPAQ with PocketPC operating system to run the project. My part consist of the development of a user interface on the Sony Clie with Palm Operating System one of the most used operating systems for PDA's. We are making different interfaces to see the interaction between users and testing the usability of the interfaces. The project has two approaches, one interface for the Nurses and the other for the Physicians. The interfaces are apart of one another, this way the Nurses can't access the physicians interface but the physicians can access the Nurses interface. Nurses can enter patient data like the Vitals and can access some parts of the patient records. The physicians can access patient records and prescribe orders. The data would be accessed and sent via wireless connections for the convenience of the users. Right now I am working on various interfaces for text and data input to test later and conclude which one is more efficient and easy for the user to learn. We are working with different keyboards, buttons, lists and other input methods to compare their efficiency. Also we are including the use of built-in camera and voice recorders to attach photos and voice notes to the patient's records. The interfaces and the wireless connections are still a work in progress. For future work we are planning to run tests for the interfaces and keep improving our work.
Behavioral Analysis of Cilk Multithreading Programs Running
on Multiprocessor Computer Systems
This project describes the study about behavior of multithreading programming running over multiprocessor computer systems and extraction of data during multithreaded program executions for posterior analysis. The programming language selected for implementation of algorithms and study of work stealing scheduling method was Cilk, where we expect to obtain rough data about multithreaded computations, perform data analysis and finally obtained information from program execution must be represented graphically in a post mortem fashion to ease the programmer to visualize partially how the written code is processed. We expect basically discriminate which threads reported by Cilk statistical options, correspond to programmer expected model and its behavior during execution. We have that enough new information will be generated offering alternative ways to understand and decide over parallel programs implementations.
Java - Based Environment for the Implementation of Kronecker
Mask Imaging Filters
This semester, I will be working in the development of a Java - based environment for the implementation of two dimensional filters (see Figure 1) for imaging operations in active remote sensing applications. One of the main objectives of this environment is to assist in the analysis and design of SAR imaging algorithms in Java. The work emphasizes the use of computational Kronecker products (CKP) algebra to filter the image. The basic operation in image filtering and analysis is the linear convolution operation.
Design, Development and Implementation of a Registration
Server for the NetTraveler Middleware System
Database middleware systems were developed to integrate heterogeneous collections of data sources distributed over a network as a homogeneous unit. Existing middleware technologies usually hides the complexity of the communication in a distributed environment. However when middleware technologies were built wireless networks weren't causing the high impact that they are causing on these days. The result was in the creation of middleware technologies that weren't suitable for Mobile devices. The next wave of information systems will feature data sources residing on handheld devices, laptops computers, embedded systems, sensors and other types of small-sized devices. The mobility advantage of these devices causes a new set of problems not seen in common networks. Lost of connectivity, low bandwidth and limited power sources are some of the new challenges presented to developers working in this area. We are in the process to create a Registration Server for NetTraveler: a database middleware system to integrate these mobile devices as reliable data sources in a computer network. The Registration Server will be used to coordinate access to a federation and to the resources that it provides. In addition the Registration Server handles all bookkeeping necessary to log events such a departure of a federation member, or a reappearance of a member at a different network. Registration Servers located at cooperative local execution environments will work together to keep track of moving data sources and route data request as appropriate.
Modeling and Simulation of Point Spread Functions for Advanced
This work is concentrated on the modeling and simulation of ambiguity functions as point spread functions (PSF) of imaging radar systems. We give special attention to synthetic aperture radar (SAR) systems as opposed to real aperture imaging radar systems (RAR). We considered in this work the theoretical formulations on imaging radar systems presented by R. Blahut on his work on remote surveillance algorithms. According with these formulations, the expected output of an imaging radar system can be viewed as a two-dimensional convolution operation of the point reflectivity density function with the radar ambiguity function acting as its impulse response signal. This filtering approach can be used to perform SAR processing in one two-dimensional operation using the fast Fourier transform (FFT). At present, some simulations have been implemented in a high-performance, shared memory, symmetric multiprocessor system (SMP) with Fortran and C language codes. The algorithms use the FFTW subroutines for the FFT computations.
XRoaster: A Tool for Catalog Management on Middleware Databases
Currently there a few tools for catalog management, everything is do it manually and require write code to change the global schema. XRoaster is a graphical tool for catalog management from integrated distributed data sources and is a tool designed to generate XML document which containing metadata about data sources. All the tasks for catalog management are integrated in this tool for use of the administrator. This application is going to improve the process of catalog management because is fast and efficient, it is user friendly and it can handle all schema management tasks. This application does not require that the administrator write any code to do the management.
Evolutionary Training of Morphological Neural Networks
This article describes the use of genetic algorithms as a training tool for morphological neural networks described by Ritter. Morphological neural networks are a new type of neural networks that replace classical operations of multiplication and addition by addition and maximum or minimum operations. The implementation of the genetic algorithm find the structure of the network, the weights and bias for each of the neuron in the way all the test patterns classify correctly in their respective classes.
"Development of User Interfaces for Accessing Electronic
Patient Record Systems with Hand Held Devices"
Point of care data entry is an important part of a clinical information system. Unfortunately, most electronic patient record systems do not provide support for point of care data entry. There are commercial products available such as Patient Keeper that that can be used for point of care data entry but these are stand-alone applications. Thus, the information does not end up in the patient's record. A more effective and useful solution would be the design of an application that could be integrated to the electronic patient record system through wireless communication. This solution will allow a real time two-way access of information. Health care professionals can retrieve information from the patient's record, enter medical orders and document the patient progress at the point of care. The system in development will allow at physicians to document and enter orders; it will allow nurses to document at point of care using a hand-held device. The application is being develop for the iPaq PocketPC platform. The application synchronizes with the electronic patient record system through a wireless expansion card. The electronic patient record system that will be used is a result of various research studies conducted at the University of Puerto Rico at Mayagüez.