Active inference and oculomotor pursuit: the dynamic causal modelling of eye movements.

This paper introduces a new paradigm that allows one to quantify the Bayesian beliefs evidenced by subjects during oculomotor pursuit. Subjects' eye tracking responses to a partially occluded sinusoidal target were recorded non-invasively and averaged. These response averages were then analysed using dynamic causal modelling (DCM). In DCM, observed responses are modelled using biologically plausible generative or forward models - usually biophysical models of neuronal activity

A Digital Program for Calculating the Interaction Between Flexible Structures, Unsteady Aerodynamics and Active Controls

A computer program, ISAC, is described which calculates the stability and response of a flexible airplane equipped with active controls. The equations of motion relative to a fixed inertial coordinate system are formulated in terms of the airplane's rigid body motion and its unrestrained normal vibration modes. Unsteady aerodynamic forces are derived from a doublet lattice lifting surface theory. The theoretical basis for the program is briefly explained together with a description of input data and output results

Measurement of interstage fluid-annulus dynamical properties

The work described in this paper is part of an Electric Power Research Institute sponsored effort to improve rotor vibrational performance on power plant feed water pumps. A major objective of this effort is to reduce vibration levels by devising inter-stage sealing configurations with optimized damping capacity, realizing that the typical multi-stage centrifugal pump has several ore inter-stage fluid annuli than it has journal bearings. Also, the fluid annuli are distributed between the journal bearings where vibration levels are highest and can therefore be 'exercised' more as dampers than can the bearings. Described in this paper is a test apparatus which has been built to experimentally determine fluid-annulus dynamical coefficients for various configurations of inter-stage sealing geometry

Integrated maneuvering and life support system simulation Final report

Integrated maneuvering and life support system simulatio

Leaving College: Why Students Withdrew from a University

The purpose of this study was to determine the reasons why students withdrew during a semester from a mid-sized, comprehensive university located in the Midwest. Six hundred forty-five students were asked to complete the ACT Withdrawing/Non-returning Student Survey during the 1992-93 academic year and summer semester. Three hundred sixty-five completed surveys were returned for a 57% response rate. Respondents indicated many different reasons for leaving which varied by year in school and whether or not the respondent was a graduate or undergraduate student. There was no typical withdrawing student and there were many reasons students withdrew over which the university has little or no control. The report concludes with a discussion of Vincent Tinto\u27s (1993) ideas concerning institutional departure. The retention and persistence of students in higher education has been the focus of serious intellectual inquiry for many years. Various concepts of institutional departure, persistence and models for programmatic interventions to reduce departure have been developed. (For example, see Pascarella & Terenzini, 1991; Stage & Rushin, 1993; Steele, Kennedy, & Gordon, 1993; Tinto, 1993; Wolfe, 1993.) The purpose of this study was to focus on one aspect of student attrition, and. to investigate the reasons and general trends as . to why students withdrew during a semester from a midsized comprehensive university located in the Midwest. This information could then be used to guide institutional action

Observation of discrete energy levels in a quantum confined system

Low temperature scanning tunneling microscope images and spectroscopic data have been obtained on subnanometer size Pb clusters fabricated using the technique of buffer layer assisted growth. Discrete energy levels were resolved in current-voltage characteristics as current peaks rather than current steps. Distributions of peak voltage spacings and peak current heights were consistent with Wigner-Dyson and Porter-Thomas distributions respectively, suggesting the relevance of random matrix theory to the description of the electronic eigenstates of the clusters. The observation of peaks rather than steps in the current-voltage characteristics is attributed to a resonant tunneling process involving the discrete energy levels of the cluster, the tip, and the states at the interface between the cluster and the substrate surface.Comment: 4 pages, 4 figure

Utilization of a fixed base simulator to study the stall and spin characteristics of fighter airplanes

Feasibility of using fixed simulator to determine stall and spin characteristics of fighter aircraf

De-biased Populations of Kuiper Belt Objects from the Deep Ecliptic Survey

The Deep Ecliptic Survey (DES) discovered hundreds of Kuiper Belt objects from 1998-2005. Follow-up observations yielded 304 objects with good dynamical classifications (Classical, Scattered, Centaur, or 16 mean-motion resonances with Neptune). The DES search fields are well documented, enabling us to calculate the probability of detecting objects with particular orbital parameters and absolute magnitudes at a randomized point in each orbit. Grouping objects together by dynamical class leads, we estimate the orbital element distributions (a, e, i) for the largest three classes (Classical, 3:2, and Scattered) using maximum likelihood. Using H-magnitude as a proxy for the object size, we fit a power law to the number of objects for 8 classes with at least 5 detected members (246 objects). The best Classical slope is alpha=1.02+/-0.01 (observed from 5<=H<=7.2). Six dynamical classes (Scattered plus 5 resonances) are consistent in slope with the Classicals, though the absolute number of objects is scaled. The exception to the power law relation are the Centaurs (non-resonant with perihelia closer than Neptune, and thus detectable at smaller sizes), with alpha=0.42+/-0.02 (7.5<H<11). This is consistent with a knee in the H-distribution around H=7.2 as reported elsewhere (Bernstein et al. 2004, Fraser et al. 2014). Based on the Classical-derived magnitude distribution, the total number of objects (H<=7) in each class are: Classical (2100+/-300 objects), Scattered (2800+/-400), 3:2 (570+/-80), 2:1 (400+/-50), 5:2 (270+/-40), 7:4 (69+/-9), 5:3 (60+/-8). The independent estimate for the number of Centaurs in the same H range is 13+/-5. If instead all objects are divided by inclination into "Hot" and "Cold" populations, following Fraser et al. (2014), we find that alphaHot=0.90+/-0.02, while alphaCold=1.32+/-0.02, in good agreement with that work.Comment: 26 pages emulateapj, 6 figures, 5 tables, accepted by A

Fertilizer requirements of unproductive soils

Citation: Nichols, Roscoe Townley. Pruning of orchard trees. Senior thesis, Kansas State Agricultural College, 1898.Morse Department of Special CollectionsIntroduction: Soils are unproductive for many reasons, among which are lack of moisture, absence of bacteria, excess of soluable salts, and some of the essential elements to plant growth. It is of this last requisite that we treat in this paper. Among the necessary chemical elements for plant growth, those that are most liable to be deficient in available form are: N. P. and K. Some soils are lacking in lime as is shown by their acidity. Since we are unable to tell the elements that are deficient in an unproductive soil by chemical analysis, we have to determine them by experimental work. A new method for determining the unproductiveness of soils is by the wire basket method. This is the method that we have used in conducting this experiment. This method is quicker than field tests and promises to be practical. The soil used in this experiment was taken from one of the poorer fields on the College Farm. It was put in good condition, different fertilizers added, placed in wire baskets, and five grains of wheat planted in each basket. After running the experiment for about four weeks the fertilizer requirement was determined by the growth of the wheat and the amount of moisture used. The baskets used were about three inches deep and three inches in diameter. They were filled with soil and then covered with paroffin. After the wheat was up the tops were sealed with paroffin and paper so as to prevent evaporizion