1,721,064 research outputs found
Interpretation of force vector recorder data describing buoy system dynamics /
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Mooring line forces on an oscillating buoy in a uniform current /
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Computation of errors in current meters attached to near-surface moorings /
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Torsion of a thin rectangular beam with axial prestress and ends constrained from warping
Get PDFThesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaf 46.by John Arnold Connally.M.S
Spatio-Temporal Data Fusion for 3D+T Image Reconstruction in Cerebral Angiography
No full textThis paper provides a framework for generating high resolution time sequences of 3D images that show the dynamics of cerebral blood flow. These sequences have the potential to allow image feedback during medical procedures that facilitate the detection and observation of pathological abnormalities such as stenoses, aneurysms, and blood clots. The 3D time series is constructed by fusing a single static 3D model with two time sequences of 2D projections of the same imaged region. The fusion process utilizes a variational approach that constrains the volumes to have both smoothly varying regions separated by edges and sparse regions of nonzero support. The variational problem is solved using a modified version of the Gauss-Seidel algorithm that exploits the spatio-temporal structure of the angiography problem. The 3D time series results are visualized using time series of isosurfaces, synthetic X-rays from arbitrary perspectives or poses, and 3D surfaces that show arrival times of the contrasted blood front using color coding. The derived visualizations provide physicians with a previously unavailable wealth of information that can lead to safer procedures, including quicker localization of flow altering abnormalities such as blood clots, and lower procedural X-ray exposure. Quantitative SNR and other performance analysis of the algorithm on computational phantom data are also presented.National Institutes of Health (U.S.)Charles Stark Draper Laboratory (Internal Research and Development funds)Cam Neely Foundation for Cancer CareNational Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant 1 R01 EB006161-01A2)National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant 1 R21 HL102685-01
Effect of Surface Patterning and Presence of Collagen I on the Phenotypic Changes of Embryonic Stem Cell Derived Cardiomyocytes
No full textEmbryonic stem cell derived cardiomyocytes have been widely investigated for stem cell therapy or in vitro model systems. This study examines how two specific biophysical stimuli, collagen I and cell alignment, affect the phenotypes of embryonic stem cell derived cardiomyocytes in vitro. Three phenotypic indicators are assessed: sarcomere organization, cell elongation, and percentage of binucleation. Murine embryonic stem cells were differentiated in a hanging drop assay and cardiomyocytes expressing GFP-α-actinin were isolated by fluorescent sorting. First, the effect of collagen I was investigated. Addition of soluble collagen I markedly reduced binucleation as a result of an increase in cytokinesis. Laden with a collagen gel layer, myocyte mobility and cell shape change were impeded. Second, the effect of cell alignment by microcontact printing and nanopattern topography was investigated. Both patterning techniques induced cell alignment and elongation. Microcontact printing of 20 μm line pattern accelerated binucleation and nanotopography with 700 nm ridges and 3.5 μm grooves negatively regulated binucleation. This study highlights the importance of biophysical cues in the morphological changes of differentiated cardiomyocytes and may have important implications on how these cells incorporate into the native myocardium.Singapore-MIT Alliance for Research and TechnologyNational Science Foundation (U.S.) ((Science and Technology Center (EBICS): Emergent Behaviors of Integrated Cellular Systems, Grant CBET-0939511)Charles Stark Draper Laboratory (Internal Research and Development Program
Focused Ion Beam Fabrication
Get PDFContains reports on three research projects.Joint Services Electronics Program (Contract DAAG29-83-K-0003)Charles Stark Draper Laboratory (Contract DL-H-225270)International Business Machines, Inc. (Contract 3260
A nested decomposition method for vehicle routing and scheduling
Get PDFIncludes bibliographical references (p. 31-32).Sponsored in part by a grant from the Charles Stark Draper Laboratory, Inc.by Anthony O. Lee and Jeremy F. Shapiro
Resolving multipath interference in time-of-flight imaging via modulation frequency diversity and sparse regularization
Get PDFTime-of-flight (ToF) cameras calculate depth maps by reconstructing phase shifts of amplitude-modulated signals. For broad illumination of transparent objects, reflections from multiple scene points can illuminate a given pixel, giving rise to an erroneous depth map. We report here a sparsity-regularized solution that separates K interfering components using multiple modulation frequency measurements. The method maps ToF imaging to the general framework of spectral estimation theory and has applications in improving depth profiles and exploiting multiple scattering.National Science Foundation (U.S.) (NSF grant 1115680)Charles Stark Draper Laboratory (grant SC001-744)International Society for Neurochemistry (ISN grant 6927356)University of Waikato (Doctoral Scholarship)Charles Stark Draper Laboratory (fellowship
Evaluation of decision aiding in submarine emergency decisionmaking
Get PDFCover title.Includes bibliographical references.Support provided by the Charles Stark Draper Laboratory, Inc. DL-K-260948 Support provided by the Joint Directors of Laboratories from the Office of Naval Research. N00014-K-85-0782by Scott T. Weingaertner, Alexander H. Levis
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