Showing papers by "Georgia Institute of Technology published in 1982"
TL;DR: In this article, it is shown that estimates of agreement based on group mean scores have been incorrectly interpreted as applying to perceptual agreement among individuals, and the logic of the approach is then extended to other studies in which inflated estimates appeared likely.
Abstract: : It is shown that estimates of agreement based on group mean scores have been incorrectly interpreted as applying to perceptual agreement among individuals. Of initial importance is a study by Drexler (1977), who concluded that a considerable proportion of the variance in climate perceptions is accounted for by organizational membership. This conclusion has been employed recently by other authors to support the assumption that individuals in the same environment tend to agree with respect to climate perceptions. The present paper demonstrates that Drexler's analysis provided inflated estimates of agreement among individuals. The logic of the approach is then extended to other studies in which inflated estimates of agreement appeared likely. (Author)
2,048 citations
TL;DR: In this article, a dielectric surface-relief grating is analyzed using rigorous coupled-wave theory and the analysis applies to arbitrary grating profiles, groove depths, angles of incidence, and wavelengths.
Abstract: Diffraction by a dielectric surface-relief grating is analyzed using rigorous coupled-wave theory. The analysis applies to arbitrary grating profiles, groove depths, angles of incidence, and wavelengths. Example results for a wide range of groove depths are presented for sinusoidal, square-wave, triangular, and sawtooth gratings. Diffraction efficiencies obtained from the present method of analysis are compared with previously published numerical results. To obtain large diffraction efficiencies (greater than 85%) for gratings with typical substrate permittivities, it is shown that the grating profile should possess even symmetry.
967 citations
TL;DR: In this article, a cubic equation of state for pure fluids is presented, which requires the critical temperature and pressure, as well as two additional parameters to characterize each particular fluid, and these parameters have been evaluated by minimizing deviations in saturated liquid densities while simultaneously satisfying the equality of fugacities along the saturation curve.
837 citations
TL;DR: In this article, the effects of information load on consumer decision-making were investigated, and respondents experienced information overload when they were provided with 10, 15, 20, or 25 choice alternatives or with information on 15 or 20 attributes.
Abstract: In an experimental investigation of the effects of information load on consumer decision making, respondents experienced information overload when they were provided with 10, 15, 20, or 25 choice alternatives or with information on 15, 20, or 25 attributes. Alternative measures of the dependent variable yielded similar results, thus enhancing confidence in these findings.
751 citations
TL;DR: In this article, the phase or magnitude information alone is not sufficient, in general, to uniquely specify a sequence, however, a large class of sequences are shown to be recoverable from their phases or magnitudes.
Abstract: This paper addresses two fundamental issues involved in the reconstruction of a multidimensional sequence from either the phase or magnitude of its Fourier transform The first issue relates to the uniqueness of a multidimensional sequence in terms of its phase or magnitude Although phase or magnitude information alone is not sufficient, in general, to uniquely specify a sequence, a large class of sequences are shown to be recoverable from their phase or magnitude The second issue which is addressed in this paper concerns the actual reconstruction of a multidimensional sequence from its phase or magnitude For those sequences which are uniquely specified by their phase, several practical algorithms are described which may be used to reconstruct a sequence from its phase Several examples of phase-only reconstruction are also presented Unfortunately, however, even for those sequences which are uniquely defined by their magnitude, it appears that a practical algorithm is yet to be developed for reconstructing a sequence from only its magnitude Nevertheless, an iterative procedure which has been proposed is briefly discussed and evaluated
472 citations
TL;DR: In this paper, the authors provide an overview of the sulfur poisoning of metal catalysts and the mechanism of sulfur poisoning, and stress the importance of experimental techniques that provide definitive, fundamental information regarding sulfur adsorption and poisoning.
Abstract: Publisher Summary This chapter provides an overview of the sulfur poisoning of metals. Sulfur apparently bonds so strongly to metal surfaces that marked activity reduction occurs at extremely low gas-phase concentrations of sulfur-containing compounds. In commercial practice, the life of supported metal catalysts may be reduced to only a few months or weeks in the presence of only ppm quantities of sulfur contaminants in the feed. Because of the essentially irreversible adsorption of sulfur compounds on metals, regeneration is usually impossible or impractical. This chapter integrates available information on the interaction of sulfur with metal surfaces with that of poisoning studies to provide a more complete picture of sulfur poisoning and of the mechanism. The chapter stresses the importance of experimental techniques that provide definitive, fundamental information regarding sulfur adsorption and poisoning.
379 citations
01 Feb 1982
375 citations
TL;DR: In this article, the authors simulate the free radical chemistries of the gas phase and aqueous phase within a warm cloud during midday solar fluxes and demonstrate that the scavenging of OH and HO2 from cloud droplets can represent a major source of free radicals to cloud water provided the accommodation or sticking coefficient for these species impinging upon water droplets is not less than 0.0001.
Abstract: Calculations are presented that simulate the free radical chemistries of the gas phase and aqueous phase within a warm cloud during midday. It is demonstrated that in the presence of midday solar fluxes, the heterogeneous scavenging of OH and HO2 from the gas phase by cloud droplets can represent a major source of free radicals to cloud water, provided the accommodation or sticking coefficient for these species impinging upon water droplets is not less than 0.0001. The aqueous-phase of HO2 radicals are found to be converted to H2O2 by aqueous-phase chemical reactions at a rate that suggests that this mechanism could produce a significant fraction of the H2O2 found in cloud droplets. The rapid oxidation of sulfur species dissolved in cloudwater by this free-radical-produced H2O2 as well as by aqueous-phase OH radicals could conceivably have a significant impact upon the chemical composition of rain.
342 citations
TL;DR: Comparison with pathologic data on localization of atherosclerotic lesions indicates that zones susceptible to disease experience low or oscillatory shear stress while regions subject to higher shear are free of deposits.
326 citations
TL;DR: In this article, a direct method for obtaining conditions under which certain degree-of-freedom Hamiltonian systems are integrable, i.e., possess $N$ integrals in involution, is described.
Abstract: A direct method is described for obtaining conditions under which certain $N$-degree-of-freedom Hamiltonian systems are integrable, i.e., possess $N$ integrals in involution. This method consists of requiring that the general solutions have the Painlev\'e property, i.e., no movable singularities other than poles. We apply this method to several Hamiltonian systems of physical significance such as the generalized H\'enon-Heiles problem and the Toda lattice with $N=2 \mathrm{and} 3$, and recover all known integrable cases together with a few new ones. For some of these cases the second integral is written down explicitly while for others integrability is confirmed by numerical experiments.
231 citations
TL;DR: In this paper, the authors correlated the monotonic and cyclic properties of three AlLi alloys with the slip behavior and found that cracks nucleated at grain boundary ledges during tensile tests and propagated either transgranularly or intergranularally along precipitate free zones.
01 May 1982-Zentralblatt für Bakteriologie Mikrobiologie und Hygiene: I. Abt. Originale C: Allgemeine, angewandte und ökologische Mikrobiologie
TL;DR: The discontinuity ofarchaebacterial lipids formulates a point for delineating early stages of biological evolution and supports the concept that archaebacteria represent a third line of evolutionary descent.
TL;DR: In this paper, the free vibrations of beams containing split regions are investigated and the frequency determinant is obtained by satisfying continuity conditions at junctions between end regions and interior regions immediately next to the end regions.
TL;DR: The objective of this phase of the study was to obtain quantitative information on the velocity field and to estimate levels and directions of wall shear stress in the region of the bifurcation.
TL;DR: In this article, path-independent integrals, of relevance in the presence of cracks, in elastic and inelastic solids are considered, and the physical interpretations of each of the integrals either in terms of crack-tip energy release rates or simply energy-rate differences in two comparison cracked-bodies are explored.
TL;DR: A bioassay was developed to test the species-recognition hypothesis and the experimental results supporting the hypothesis suggest that cuticular hydrocarbons might serve as species- and caste- Recognition cues.
Abstract: The cuticular hydrocarbon components of four castes ofReticulitermes virginicus (Banks) have been identified and quantitated. Components identified includen-alkanes; 2-, 3-, 11-, 13-, and 15-methyl-alkanes; 11,15-dimethylalkanes, (Z)-9-alkenes; (Z,Z)-7,9-dienes; and (E/Z)-6,9-dienes ranging in carbon number from C21 to C40. All caste forms ofR.virginicus contained the same components, but showed caste-specific proportions. Comparison of these hydrocarbons with those of the sympatric termiteR. flavipes (Kollar) suggest that cuticular hydrocarbons might serve as species- and caste-recognition cues. A bioassay was developed to test this species-recognition hypothesis, with the experimental results supporting the hypothesis.
TL;DR: A new modeling methodology to characterize failure processes in digital computers due to hardware transients is presented, and models of common fault-tolerant redundant structures are developed using decreasing hazard function distributions.
Abstract: In this paper a new modeling methodology to characterize failure processes in digital computers due to hardware transients is presented. The basic assumption made is that system sensitivity to hardware transient errors is a function of critical resources usage. The failure rate of a given resource is approximated by a deterministic function of time, depending on the average workload of that resource, plus a Gaussian process. The probability density function of the time to failure obtained under this assumption has a decreasing hazard function, explaining why decreasing hazard function densities such as the Weibull fit experimental data so well. Data on transient errors obtained from several systems are analyzed. Statistical tests confirm the good fit between decreasing hazard distributions and actual data. Finally, models of common fault-tolerant redundant structures are developed using decreasing hazard function distributions. The analysis indicates significant differences between reliability predictions based on the exponential distribution and those based on decreasing hazard function distributions. Reliability differences of 0.2 and factors greater than 2 in Mission Time Improvement are seen in model results. System designers should be aware of these differences.
TL;DR: In this paper, a theoretical analysis of particle formation mechanisms under stratospheric conditions was carried out using a fully interactive one-dimensional model of aerosol formation and evolution, and the formation mechanisms considered are homogeneous, ion and heterogeneous heteromolecular nucleation of H 2 SO 4 H 2 O systems, the clustering of sulfate radicals, and heterogenous nucleation onto stable neutral ion-ion recombination complexes.
TL;DR: In this article, the rate reduction of hexavalent chromium (Cr(VI) by metallic iron under a range of conditions was studied in batch systems and the rate constant was evaluated and found to have a value of 5.45 × 10−5 1 cm−2 min−1.
TL;DR: This paper reviews the information overload controversy and presents a methodology for investigating the effects of information load on consumer decision making performance and proposes a framework for doing so.
Abstract: This paper reviews the information overload controversy and presents a methodology for investigating the effects of information load on consumer decision making performance. The proposed framework ...
TL;DR: This work provides a precise characterization of the closed-form expression for any value function in integer programs in which the objective function and constraint matrix are fixed while the right-hand side varies.
Abstract: We consider integer programs in which the objective function and constraint matrix are fixed while the right-hand side varies. The value function gives, for each feasible right-hand side, the criterion value of the optimal solution. We provide a precise characterization of the closed-form expression for any value function. The class of Gomory functions consists of those functions constructed from linear functions by taking maximums, sums, non-negative multiples, and ceiling (i.e., next highest integer) operations. The class of Gomory functions is identified with the class of all possible value functions by the following results: (1) for any Gomory functiong, there is an integer program which is feasible for all integer vectorsv and hasg as value function; (2) for any integer program, there is a Gomory functiong which is the value function for that program (for all feasible right-hand sides); (3) for any integer program there is a Gomory functionf such thatf(v)≤0 if and only ifv is a feasible right-hand side. Applications of (1)–(3) are also given.
01 Feb 1982
TL;DR: In this paper, it was shown that the set of factorable multi-dimensional polynomials is extremely small in the sense that almost all polynomials in two or more variables are irreducible.
Abstract: Polynomials in more than one variable arise frequently in multidimensional signal processing applications. Unlike polynomials in a single variable, multidimensional polynomials cannot, in general, be factored. In this note, it is shown that the set of factorable multi-dimensional polynomials is extremely small in the sense that almost all polynomials in two or more variables are irreducible.
TL;DR: In this article, measurements of H2O2 in rainwater collected in Miami, Florida, and the Bahama Islands area indicate the presence of aqueous phase reactions within the cloudwater rather than via rainout and washout of gaseous H 2O2.
Abstract: Measurements of H2O2 in rainwater collected in Miami, Florida, and the Bahama Islands area indicate the presence of H2O2 concentration levels ranging from 100,000 to 700,000 M No systematic trends in H2O2 concentration were observed during an individual storm, in marked contrast to the behavior of other anions for example, NO3(-), SO4(-2), and Cl(-) The data suggest that a substantial fraction of the H2O2 found in precipitation is generated by aqueous-phase reactions within the cloudwater rather than via rainout and washout of gaseous H2O2
TL;DR: The algorithm is easily coded: a complete BASIC program is included in the appendix and, since the algorithm consists essentially of sorting, points are easily added or removed.
TL;DR: In this paper, the properties of matrix orthogonal polynomials are investigated using the techniques of scattering and inverse scattering theory, and the discrete matrix analog of the Jost function is introduced and its properties investigated.
Abstract: The techniques of scattering and inverse scattering theory are used to investigate the properties of matrix orthogonal polynomials. The discrete matrix analog of the Jost function is introduced and its properties investigated. The matrix distribution function with respect to which the polynomials are orthonormal is constructed. The discrete matrix analog of the Marchenko equation is derived and used to obtain further results on the matrix Jost function and the distribution function.
TL;DR: In this paper, a computer program for the optimal economic design of an X control chart is presented, where the mean time between process shifts is an exponentially distributed random variable, and the program finds the sample size, control limit width and interval between samples that minimize the expected total costs per unit time.
Abstract: A computer program for the optimal economic design of an X control chart is presented. A single assignable cause system is assumed, where the mean time between process shifts is an exponentially distributed random variable. Given fixed and variable sampling costs, the costs of investigating action signals, the penalty cost of production in the out-of-control state, and other parameters describing process performance, the program finds the sample size, control limit width and interval between samples that minimize the expected total costs per unit time.
TL;DR: The optimization problem of minimizing the completion time in permutation flow shop scheduling is considered under the assumption that the processing times of a job on different machines are independent and identically distributed random variables.
Abstract: The optimization problem of minimizing the completion time in permutation flow shop scheduling is considered under the assumption that the processing times of a job on different machines are independent and identically distributed random variables. Models with and without intermediate storage are considered. Solutions for special cases are found and based on these results a more general rule of thumb is obtained.
TL;DR: In this article, a planar dielectric grating diffraction theory is reviewed for the case of a general sinusoidal permittivity planar grating with slanted fringes and plane wave incidence at an arbitrary angle.
Abstract: Various planar dielectric grating diffraction theories are reviewed for the case of a general sinusoidal permittivity planar grating with slanted fringes and plane wave incidence at an arbitrary angle. Exact formulations without approximations (rigorous coupled-wave analysis and rigorous modal analysis) are developed first. Then, using a series of fundamental assumptions, rigorous theory is shown to reduce to the various approximate theories in the appropriate limits. The implications of these fundamental assumptions are discussed.
TL;DR: A small group of chimpanzees was studied before and after their translocation from a laboratory environment to a naturalistic man-made island, where stereotyped and self-directed behavior was dramatically reduced.
Abstract: A small group of chimpanzees was studied before and after their translocation from a laboratory environment to a naturalistic man-made island. After 22 weeks of island living, stereotyped and self-directed behavior was dramatically reduced. Social behavior did not improve on the island, but the animals were more active and manipulative in the enriched setting. Naturalistic environments are clearly conducive to normal behavior patterns.
TL;DR: The local environment of tryptophan 62 in hen egg-white lysozyme was examined using Kyn 62-lysozyme and factors influencing kynurenine fluorescence and N'-formylkynurenines fluorescence examined were neighboring groups, ionic strength, temperature, and protein denaturants.
Abstract: Several kynurenine derivatives including N'-formylkynurenine were prepared in high purity by the ozonization of the corresponding indole compounds. The fluorescence characteristics of those derivatives were examined in connection with the use of their fluorophores as reporters for the local environment of tryptophan in proteins. Kynurenine is a weak emitter of fluorescence, with an emission maximum at 480 nm on excitation at 365 nm. With decreasing solvent polarity, the fluorescence intensity increases logarithmically and the emission maximum shifts to blue. A linear relation between these fluorescence characteristics and solvent polarity exists when the polarity is shown in terms of dielectric constant. N'-Formylkynurenine is a somewhat stronger emitter of fluorescence than kynurenine. The emission maximum is 434 nm on excitation at 325 nm and it shifts to blue in solvents of low polarity. This blue shift is also linear with respect to the dielectric constant of the solvent. Other factors influencing kynurenine fluorescence and N'-formylkynurenine fluorescence examined were neighboring groups, ionic strength, temperature, and protein denaturants. Based on the results of the present investigation, the local environment of tryptophan 62 in hen egg-white lysozyme was examined using Kyn 62-lysozyme.