ALBERT

Description: A computer image processing technique was developed to estimate the degree of atherosclerosis in the human femoral artery. With an angiographic film of the vessel as input, the computer was programmed to estimate vessel abnormality through a series of measurements, some derived primarily from the vessel edge information and others from optical density variations within the lumen shadow. These measurements were combined into an atherosclerosis index, which was found to correlate well with both visual and chemical estimates of atherosclerotic disease.

Description: The Kansas City Division of Allied Signal Inc., as part of the Integrated Flexible Manufacturing Program (IFMP), is developing an integrated manufacturing environment. Several systems are being developed to produce standards and automation tools for specific activities within the manufacturing environment. The Advanced Manufacturing Development System (AMDS) is concentrating on information standards (STEP) and product data transfer; the Expert Cut Planner system (XCUT) is concentrating on machining operation process planning standards and automation capabilities; the Advanced Numerical Control system (ANC) is concentrating on NC data preparation standards and NC data generation tools; the Inspection Planning and Programming Expert system (IPPEX) is concentrating on inspection process planning, coordinate measuring machine (CMM) inspection standards and CMM part program generation tools; and the Intelligent Scheduling and Planning System (ISAPS) is concentrating on planning and scheduling tools for a flexible manufacturing system environment. All of these projects are working together to address information exchange, standardization, and information sharing to support rapid prototyping in a Flexible Manufacturing System (FMS) environment.

Description: Image processing technique quantifies human atherosclerosis by computer analysis of arterial angiograms. X-ray film images are scanned and digitized, arterial shadow is tracked, and several quantitative measures of lumen irregularity are computed. In other tests, excellent agreement was found between computer evaluation of femoral angiograms on living subjects and evaluation by teams of trained angiographers.

Description: After more than six years in orbit around Saturn, the Cassini Composite Infrared Spectrometer (CIRS) has acquired an extensive set of measurements of Saturn's main rings (A, B, C and Cassini Division) in the thermal infrared. Temperatures were retrieved for the lit and unlit rings over a variety of ring geometries that include phase angle, solar and spacecraft elevations and local time. We show that some of these parameters (solar and spacecraft elevations, phase angle) play a role in the temperature variations in the first order, while the others (ring and particle local time) produced second order effects. The results of this comparison will be presented.

Description: A computer system has been developed to quantify the degree of atherosclerosis in the human femoral artery. The analysis involves first scanning and digitizing angiographic film, then tracking the outline of the arterial image and finally computing the relative amount of roughness or irregularity in the vessel wall. The image processing system and method are described.

Description: The paper discusses the estimation of the degree of atherosclerosis in the human femoral artery through the use of a digital image processing system for vascular angiograms. The film digitizer uses an electronic image dissector camera to scan the angiogram and convert the recorded optical density information into a numerical format. Another processing step involves locating the vessel edges from the digital image. The computer has been programmed to estimate vessel abnormality through a series of measurements, some derived primarily from the vessel edge information and others from optical density variations within the lumen shadow. These measurements are combined into an atherosclerosis index, which is found in a post-mortem study to correlate well with both visual and chemical estimates of atherosclerotic disease.

Description: We combine a variety of measurements to develop a composite picture of the post-Pinatubo aerosol and assess the consistency and uncertainties of the measurement and retrieval techniques Satellite infrared spectroscopy, particle morphology, and evaporation temperature measurements are in accord with theoretical calculations In showing a dominant particle composition of H2SO4-H2O mature with H2SO4 weight traction of 65-80% for most stratospheric temperatures and humidities. Important exceptions are: (1) the presence of volcanic ash at all attitudes initially and in a layer just above the tropopause until at least March 1992, and (2) much smaller H2SO4 weight fractions at the low temperatures attained In high latitude winters and at the tropical tropopause. Laboratory spectroscopy and theoretical calculations yield wavelength- and temperature-dependent refractive indices for the dominant H2SO4-H2O droplets. These in turn permit derivation of particle size spectra from measured optical depth spectra for comparison to direct measurements by impactors and optical counters, All three techniques paint a generally consistent picture of the evolution of R(sub eff) the effective, or area-weighted, particle radius. In the first month after the eruption, although particle numbers increased by orders of magnitude, R(sub eff) was similar to the pre-eruption value of 0.1 to 0.2 microns because both small (r less than 0.2 microns) and large (r greater than 0.6 microns) particles increased in number. Over the next 3-6 months, R(sub eff) increased to about 0.5 microns, reflecting particle growth through condensation and coagulation. In general, R(sub eff) continued to increase for about a year after the eruption. Extinction spectra computed from in situ size distribution measurements are consistent with optical depth measurements, which show spectra with maxima initially at wavelengths of 0.42 microns or less, and thereafter progressively increasing to between 0.78 and 1 micron. Not until 1993 does optical depth spectra begin to show a clear return to the preeruption signature of maximizing at the shortest visible wavelengths or in the near UV. This coupled evolution in particle size distribution and optical depth spectra helps explain the relationship between the global maps of 0.5- and 1.0-kilometer optical depth derived from the AVHRR and SAGE satellite measurements. It also sets a context for evaluating remaining uncertainties in each of these satellite data products. We also show how the effects of wavelength-dependent refractive index on backscatter spectra can influence particle sizes retrieved from multiwavelength lidar measurements.

Description: We combine space, air, and ground measurements to develop a composite picture of the post-Pinatubo aerosol, and assess the consistency and uncertainties of various measurement and retrieval techniques. impactor and optical counter measurements, as well as retrievals from optical depth spectra, paint a generally consistent picture of the evolution of particle effective radii, R(sub eff). In the first month after the eruption, although particle numbers increased by orders of magnitude, R(sub eff) was similar to the preeruption value of 4.2 micrometers, because both small (r less than 0.25 micrometers) and large (r greater than 0.6 micrometers) particles increased in number, Over the next 3-6 months, R(sub eff) increased rapidly to about 0.5 micrometers. In general, R(sub eff) continued to increase for about a year after the eruption. The peak wavelength of optical depth spectra increased from initial values of less than 0.42 micrometers to values between 0.78 and 1 micrometer. This coupled evolution in particle size distribution and optical depth spectra helps explain the relationship between the global maps of 0.5 and 1.0-micrometer optical depth derived from the AVHRR and SAGE satellite measurements. It also sets a context for evaluating remaining uncertainties in each of these satellite data products. We also make consensus recommendations for particle composition, shape, and temperature- and wavelength-dependent refractive index, and show how the latter effect on backscatter spectra can influence particle sizes retrieved from multiwavelength lidar measurements.