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Integer Representation of Decimal Numbers for Exact Computations
No full textA scheme is presented and software is documented for representing as integers input decimal numbers that have been stored in a computer as double precision floating point numbers and for carrying out multiplications, additions and subtractions based on these numbers in an exact manner. The input decimal numbers must not have more than nine digits to the left of the decimal point. The decimal fractions of their floating point representations are all first rounded off at a prespecified location, a location no more than nine digits away from the decimal point. The number of digits to the left of the decimal point for each input number besides not being allowed to exceed nine must then be such that the total number of digits from the leftmost digit of the number to the location where round-off is to occur does not exceed fourteen
Three Rings of Polyhedral Simple Functions
No full textWe survey three ways to multiply elements of the additive subgroup of the group of real-valued functions on R-d which is generated by the indicator functions of polyhedra. In the resulting commutative rings, identities often correspond to useful techniques of decomposition of polyhedra. We are led immediately to various interesting topics, including Ehrhart polynomials, mixed volumes, Gram's relation, and transversal characteristics
Simulating Timescale Dynamics of Network Traffic Using Homogeneous Modeling
No full textSimulating and understanding traffic dynamics in large networks are difficult and challenging due to the complexity of such networks and the limitations inherent in simulation modeling. Typically, simulation models used to study traffic dynamics include substantial detail representing protocol mechanisms across several layers of functionality. Such models must be restricted in space and time in order to be computationally tractable. We propose an alternative simulation approach that uses homogeneous modeling with an increased level of abstraction, in order to explore networks at larger space-time scales than otherwise feasible and to develop intuition and insight about the space-time dynamics of large networks. To illustrate the utility of our approach, we examine some current understandings of the timescale dynamics of network traffic, and we discuss some speculative results obtained with homogeneous modeling. Using a wavelet-based technique, we show correlation structures, and changes in correlation structures, of network traffic under variations in traffic sources, transport mechanisms, and network structure. Our simulation results justify further investigation of our approach, which might benefit from cross-verifications against more detailed simulation models
A Summary of Lightpipe Radiation Thermometry Research at NIST
No full textDuring the last 10 years, research in lightpipe radiation thermometry has significantly reduced the uncertainties for temperature measurements in semiconductor processing. The National Institute of Standards and Technology (NIST) has improved the calibration of lightpipe radiation thermometers (LPRTs), the characterization procedures for LPRTs, the in situ calibration of LPRTs using thin-film thermocouple (TFTC) test wafers, and the application of model-based corrections to improve LPRT spectral radiance temperatures. Collaboration with industry on implementing techniques and ideas established at NIST has led to improvements in temperature measurements in semiconductor processing. LPRTs have been successfully calibrated at NIST for rapid thermal processing (RTP) applications using a sodium heat-pipe blackbody between 700 degrees C and 900 degrees C with an uncertainty of about 0.3 degrees C (k=1) traceable to the International Temperature Scale of 1990. Employing appropriate effective emissivity models, LPRTs have been used to determine the wafer temperature in the NIST RTP Test Bed with an uncertainty of 3.5 degrees C. Using a TFTC wafer for calibration, the LPRT can measure the wafer temperature in the NIST RTP Test Bed with an uncertainty of 2.3 degrees C. Collaborations with industry in characterizing and calibrating LPRTs will be summarized, and future directions for LPRT research will be discussed
Intercomparison of the LBIR Absolute Cryogenic Radiometers to the NIST Optical Power Measurement Standard
No full textThe Low Background Infrared calibration (LBIR) facility at the National Institute of Standards and Technology (NIST) presently maintains four absolute cryogenic radiometers (ACRs) which serve as standard reference detectors for infrared calibrations performed by the facility. The primary standard for optical power measurements at NIST-Gaithersburg has been the High Accuracy Cryogenic Radiometer (HACR). Recently, an improved radiometer, the Primary Optical Watt Radiometer (POWR), has replaced the HACR as the primary standard. In this paper, we present the results of comparisons between the radiometric powers measured by the four ACRs presently maintained by the LBIR facility to that measured by the HACR and POWR. This was done by using a Si photodiode light-trapping detector as a secondary transfer standard to compare the primary national standards to the ACRs maintained by the LBIR facility. The technique used to compare an ACR to the trap detector is described in detail. The absolute optical power measurements are found to be within 0.1% of the primary standard for all the ACRs examined in this study
Ambiguities in Powder Indexing: the Impact of a Quaternary Lattice Metric Singularity on the Characterization of Mawsonite and Chatkalite
No full textA lattice metric singularity occurs when unit cells defining two ( or more) lattices yield the identical set of unique calculated d-spacings. The minerals Mawsonite and Chatkalite are of especial interest as both are characterized by tetragonal unit cells that correspond to the second member of a quaternary lattice metric singularity. This singularity includes lattices that are Cubic I, Tetragonal P, Orthorhombic F, and Orthorhombic P. The Mawsonite and Chatkalite lattices are unique in that they are highly specialized. In each case: ( 1) the determinative c/a ratio is very near 1/root 2, ( 2) the symmetrical scalars of the reduced form [ a . a : b . b : c . c = 1: 2: 2] have greater specialization than required for the given reduced form type, ( 3) the tetragonal lattice has derivative lattices of higher symmetry, and ( 4) the powder pattern is highly compressed. Mawsonite and Chatkalite serve as exemplar-type compounds. Their tetragonal structure has important implications in structure determination using powder diffraction data. First, any cubic I lattice - established solely on the basis of indexing procedures - may actually be tetragonal or orthorhombic. Second, in establishing the lattice of an unknown, results from powder data indexing require routine confirmation by other techniques ( e. g., single crystal, optical, etc.)
Russell A. Kirsch
No full textRUSSELL A. KIRSCH
Inducted: 2006
Citation:
For pioneering research initiating three branches of computer science: Image Processing, Syntactic Pattern Recognition and Chemical Structure Searching
Tenure: 1951-1985
Birth: 1929, New York City, New York
Education:
New York University, BEE (Electrical Engineering), 1950
Harvard University, MS (Engineering Science Applied Physics), 1952
American University, (Mathematics), 1954
Massachusetts Institute of Technology, (Computer Science), 1958
Positions held:
Electronic Engineer, Data Processing Systems Division, 1951-1970
Computer Scientist, Applied Mathematics Division, 1971-1985
Guest Researcher, Manufacturing Engineering Laboratory, 1985-2006
Honors:
American Association for the Advancement of Science, Fellow
First Digital Image included in “100 Photographs that Changed the World,” 2003
Memberships:
Association for Computing Machinery
Institute of Electrical and Electronics Engineers
American Association for the Advancement of Science
Publications:
More than 20 publications including:
Kirsch, R. A., Cahn, L., Ray, L. C., and Urban, G. H., “Experiments in Processing Pictorial Information with a Digital Computer,” Proceedings Eastern Joint Computer Conference, Inst. Radio Eng. and Assn. Computing Mach., (December 1957).
Kirsch, R. A., “Computer Interpretation of English Text and Picture Patterns,” IEEE Trans. Elect. Comp., EC-13, 363-376 (August 1964).
Kirsch, R.A., Computer Determination of the Constituent Structure of Biological Images, Computers and Biomedical Research, 4, 315-328, (1971).
Kirsch, Russell, Kirsch, J., The Anatomy of Painting Style: Description with Computer Rules, Leonardo, 21:4, (1988).
Kirsch, Russell, Photogrammetric Reconstruction of Petroglyphs, American Indian Rock Art, 23, 177-182, (1997).
Kirsch, R. A., SEAC and the Start of Image Processing at the National Bureau of Standards, IEEE Annals of the History of Computing, 20:2, (1998)
Fast Algorithms for Structured Least Squares and Total Least Squares Problems
No full textWe consider the problem of solving least squares problems involving a matrix M of small displacement rank with respect to two matrices Z(1) and Z(2). We develop formulas for the generators of the matrix (MM)-M-H in terms of the generators of M and show that the Cholesky factorization of the matrix (MM)-M-H can be computed quickly if Z(1) is close to unitary and Z(2) is triangular and nilpotent. These conditions are satisfied for several classes of matrices, including Toeplitz, block Toeplitz, Hankel, and block Hankel, and for matrices whose blocks have such structure. Fast Cholesky factorization enables fast solution of least squares problems, total least squares problems, and regularized total least squares problems involving these classes of matrices
One-Center Location With Block and Euclidean Distance
No full textA geometrical analysis is made of the dual simplex algorithm applied to a linear programming formulation of the one-center location problem in IR2 using block distance. A geometric rule is given, and shown to be equivalent to the minimum ratio rule of the simplex algorithm, for updating the dual basis. The geometric analysis is applied to the Euclidean distance one-center problem and yields an alternative updating procedure for the dual algorithm
Bayesian Tomography for Projections with an Arbitrary Transmission Function with an Application in Electron Microscopy
No full textThe vast majority of the developments in tomography assume that the transmission of the probe through the sample follows Beer's Law, i.e., the rule of exponential attenuation. However, for transmission electron microscopy of samples a few times their mean free path, Beer's Law is no longer an accurate description of the transmission of the probe as a function of the sample thickness. Recent simulations [Z. H. Levine, Appl. Phys. Lett. 82, 3943 ( 2003)] have demonstrated accounting for the correct transmission function leads to superior tomographic reconstructions for a photonic band gap sample 8 micro-m square. Those recent simulations assumed that data was available at all angles, i.e., over 180 degrees. Here, we consider a limited-angle case by generalizing the Bayesian formalism of Bouman and Sauer to allow an arbitrary transmission function. The new formalism is identical to that of Bouman and Sauer when the transmission function obeys Beer's Law. The examples, based on 140 degrees of data, suggest that using the physical transmission function is a requirement for performing limited angle reconstructions