Modelling the relationship between planning, control, perception and execution behaviours in interactive worksystems

This paper presents a model of planning carried out by interactive worksystems which attempts: 1. To describe the relationship between planning, control, perception and execution behaviours; 2. To make explicit how these may be distributed across the user and physically separate devices. Such a model, it is argued, is more suitable to support HCI design practice than theories of planning in cognitive science which focus on problem-solving methods and representations. To demonstrate the application of the model to work situations, it is illustrated by examples drawn from an observational study of secretarial office administration

A New Linear Inductive Voltage Adder Driver for the Saturn Accelerator

Saturn is a dual-purpose accelerator. It can be operated as a large-area flash x-ray source for simulation testing or as a Z-pinch driver especially for K-line x-ray production. In the first mode, the accelerator is fitted with three concentric-ring 2-MV electron diodes, while in the Z-pinch mode the current of all the modules is combined via a post-hole convolute arrangement and driven through a cylindrical array of very fine wires. We present here a point design for a new Saturn class driver based on a number of linear inductive voltage adders connected in parallel. A technology recently implemented at the Institute of High Current Electronics in Tomsk (Russia) is being utilized[1]. In the present design we eliminate Marx generators and pulse-forming networks. Each inductive voltage adder cavity is directly fed by a number of fast 100-kV small-size capacitors arranged in a circular array around each accelerating gap. The number of capacitors connected in parallel to each cavity defines the total maximum current. By selecting low inductance switches, voltage pulses as short as 30-50-ns FWHM can be directly achieved.Comment: 3 pages, 4 figures. This paper is submitted for the 20th Linear Accelerator Conference LINAC2000, Monterey, C

Engineering handbook on the atmospheric environmental guidelines for use in wind turbine generator development

The guidelines are given in the form of design criteria relative to wind speed, wind shear, turbulence, wind direction, ice and snow loading, and other climatological parameters which include rain, hail, thermal effects, abrasive and corrosive effects, and humidity. This report is a presentation of design criteria in an engineering format which can be directly input to wind turbine generator design computations. Guidelines are also provided for developing specialized wind turbine generators or for designing wind turbine generators which are to be used in a special region of the United States

Mathematical specifications of the Onboard Navigation Package (ONPAC) simulator (revision 1)

The mathematical theory of the computational algorithms employed in the onboard navigation package system is described. This system, which simulates an onboard navigation processor, was developed to aid in the design and evaluation of onboard navigation software. The mathematical formulations presented include the factorized UDU(T) form of the extended Kalman filter, the equations of motion of the user satellite, the user clock equations, the observation equations and their partial derivatives, the coodinate transformations, and the matrix decomposition algorithms

Solving the Dirac equation with nonlocal potential by Imaginary Time Step method

The Imaginary Time Step (ITS) method is applied to solve the Dirac equation with the nonlocal potential in coordinate space by the ITS evolution for the corresponding Schr\"odinger-like equation for the upper component. It is demonstrated that the ITS evolution can be equivalently performed for the Schr\"odinger-like equation with or without localization. The latter algorithm is recommended in the application for the reason of simplicity and efficiency. The feasibility and reliability of this algorithm are also illustrated by taking the nucleus $^{16}$O as an example, where the same results as the shooting method for the Dirac equation with localized effective potentials are obtained

Evolution of Nuclear Shell Structure due to the Pion Exchange Potential

The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of $\pi$-exchange potential is studied in detail. The energy differences between the neutron orbits \Lrb{\nu1h_{9/2},\nu 1i_{13/2}} in the N=82 isotones and between the proton ones \Lrb{\pi1g_{7/2},\pi1h_{11/2}} in the Z=50 isotopes are extracted as a function of neutron excess $N-Z$. A kink around $Z = 58$ for the N=82 isotones is found as an effect resulting from pion correlations. It is shown that the inclusion of $\pi$-coupling plays a central role to provide realistic isospin dependence of the energy differences. In particular, the tensor part of the $\pi$-coupling has an important effect on the characteristic isospin dependence observed in recent experiments.Comment: 4 pages and 4 figure

Collisions at infinity in hyperbolic manifolds

For a complete, finite volume real hyperbolic n-manifold M, we investigate the map between homology of the cusps of M and the homology of $M$. Our main result provides a proof of a result required in a recent paper of Frigerio, Lafont, and Sisto

The Nullity of Bicyclic Signed Graphs

Let \Gamma be a signed graph and let A(\Gamma) be the adjacency matrix of \Gamma. The nullity of \Gamma is the multiplicity of eigenvalue zero in the spectrum of A(\Gamma). In this paper we characterize the signed graphs of order n with nullity n-2 or n-3, and introduce a graph transformation which preserves the nullity. As an application we determine the unbalanced bicyclic signed graphs of order n with nullity n-3 or n-4, and signed bicyclic signed graphs (including simple bicyclic graphs) of order n with nullity n-5

Classification of the organisms important in dairy products I. Streptococcus liquefaciens

1. A satisfactory method was developed for the isolation of acid-proteolytic streptococci from dairy products. The organisms were found in milk and various derivatives of it, but always comprised only a relatively small percentage of the total flora; they were most regularly isolated from ripened cheddar cheese. 2. Litmus milk was reduced by some cultures before coagulation and by others after coagulation. The latter, from the standpoint of reduction, are comparable to Streptococcus lactis var. anoxyphilus. The acid-proteolytic streptococci coagulated milk by enzyme action rather than by the formation of acid. The titratable acidities of 15 cultures at the time of coagulation averaged 0.27 percent, while the pH values averaged 5.90. 3. The general characters of the 101 cultures studied were found to be identical, except for the rapidity of reduction of litmus milk and the fermentation of sucrose. The organisms were identified as Streptococcus liquefaciens Orla-Jensen. 4. When incubated 7 days at 21° C., the 101 cultures varied widely in the production of volatile acid, carbon dioxide and acetylmethylcarbinol in skimmilk. Diacetyl was not produced by any of a number of cultures investigated. Volatile acid production was not correlated with the fermentation of sucrose or the rapidity of reduction of litmus milk. The production of carbon dioxide and acetylmethylcarbinol did not vary directly with the volatile acid produced; although high carbon dioxide and acetylmethylcarbinol production t ended to accompany high volatile acid production, considerable intergradation existed. The production of volatile acid, carbon dioxide and acetylmethylcarbinol was generally lower at 37° C. than at 21° C. 5. With an incubation of 7 days at 21° C., the addition of 0.2 (or in a few cases 0.4) percent citric acid to skimmilk at the time of inoculation generally resulted in a decreased volatile acid production with the 39 cultures studied, although an occasional culture gave a definite increase. The production of acetylmethylcarbinol was increased by the addition of 0.2 percent citric acid with 9 of the 33 cultures employed, 4 of the increases being significant. The four cultures giving the significant increases were the ones that gave an increased production of volatile acid with added citric acid. 6. With an incubation of 7 days at 21° C., the addition of 0.15 ml. of acetaldehyde to 300 ml. of skimmilk at the time of inoculation generally resulted in a decreased volatile acid production with the 33 cultures studied, while the addition of either 0.15 or 0.18 ml. of acetaldehyde increased the yield of acetylmethylcarbinol with 6 of the 24 cultures employed, 3 of the increases being striking. In a study of two cultures that were known to give an increased production of acetylmethylcarbinol on the addition of acetaldehyde to skimmilk cultures, the time of adding the aldehyde was found to have a pronounced effect, the highest production being obtained when the aldehyde was added 14 or 16 hours after inoculation, rather than either earlier or later. 7. The neutralization of two well ripened cultures to about the original acidity of the milk and subsequent incubation at 21 ° C. resulted in a slightly increased acetylmethylcarbinol production rather than in a destruction of the product. None of the five. cultures studied produced 2,3-butylene glycol. 8. Either d lactic acid or d and i acid was produced by the 15 cultures examined. 9. Butterfat and cottonseed oil were not hydrolyzed by the 101 cultures while tripropionin and tributyrin were hydrolyzed by some cultures and not by others. 10. The four cultures studied were found to greatly increase the soluble nitrogen in milk. Amino nitrogen was significantly increased as well as the fractions soluble in trichloracetic acid and the fractions soluble and insoluble in ethyl alcohol or phosphotungstic acid. Proteolysis was largely complete after a comparatively short incubation period. The distribution of the soluble nitrogen into various fractions was practically the same with the different cultures and was essentially the same at 37° and 21° C. 11. S. liquefaciens lived in cultures much longer than S. lactis. It remained viable at about 5° C. over a long period of time. 12. Resistance to heat was found to vary considerably with the culture used and with its age. All six of the cultures studied were killed in 40 minutes at 65.6° C