Models of incremental concept formation

Given a set of observations, humans acquire concepts that organize those observations and use them in classifying future experiences. This type of concept formation can occur in the absence of a tutor and it can take place despite irrelevant and incomplete information. A reasonable model of such human concept learning should be both incremental and capable of handling this type of complex experiences that people encounter in the real world. In this paper, we review three previous models of incremental concept formation and then present CLASSIT, a model that extends these earlier systems. All of the models integrate the process of recognition and learning, and all can be viewed as carrying out search through the space of possible concept hierarchies. In an attempt to show that CLASSIT is a robust concept formation system, we also present some empirical studies of its behavior under a variety of conditions

Lecture notes on sediment transportation and channel stability

These notes have been prepared for a series of lectures on sediment transportation and channel stability given by the authors to a group of engineers and geologists of the U. S. Department of Agriculture assembled at Caltech on September 12-16,1960. The material herein is not intended to serve as a complete textbook, because it covers only subjects of the one-week sequence of lectures Due to limitation of space and time, coverage of many subjects is brief and others are omitted altogether. At the end of each chapter the reader will find a selected list of references for more detailed study

The Emergence of Standard English

Language scholars have traditionally agreed that the development of the English language was largely unplanned. Fisher challenges this view, demonstrating that the standardization of writing and pronunciation was, and still is, made under the control of political and intellectual forces. There is much to interest scholars of late Middle English language and literature. -- Journal of English and Germanic Philology Fisher\u27s argument about Chancery English in the fifteenth century deserves to be widely known. -- Speculum The coherence of the story that Fisher traces and the archival materials that he has provided will continue to stimulate scholarly investigation and discovery. -- Studies in the Age of Chaucerhttps://uknowledge.uky.edu/upk_english_language_and_literature/1000/thumbnail.jp

A summary of the forebody high-angle-of-attack aerodynamics research on the F-18 and the X-29A aircraft

High-angle-of-attack aerodynamic studies have been conducted on both the F18 High Alpha Research Vehicle (HARV) and the X-29A aircraft. Data obtained include on- and off-surface flow visualization and static pressure measurements on the forebody. Comparisons of similar results are made between the two aircraft where possible. The forebody shapes of the two aircraft are different and the X-29A forebody flow is affected by the addition of nose strakes and a flight test noseboom. The forebody flow field of the F-18 HARV is fairly symmetric at zero sideslip and has distinct, well-defined vortices. The X-29A forebody vortices are more diffuse and are sometimes asymmetric at zero sideslip. These asymmetries correlate with observed zero-sideslip aircraft yawing moments

In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation

In-flight flow visualization characteristics of the NASA F-18 high alpha research vehicle at high angles of attack

Surface and off-surface flow visualization techniques were used to visualize the 3-D separated flows on the NASA F-18 high alpha research vehicle at high angles of attack. Results near the alpha = 25 to 26 deg and alpha = 45 to 49 deg are presented. Both the forebody and leading edge extension (LEX) vortex cores and breakdown locations were visualized using smoke. Forebody and LEX vortex separation lines on the surface were defined using an emitted fluid technique. A laminar separation bubble was also detected on the nose cone using the emitted fluid technique and was similar to that observed in the wind tunnel test, but not as extensive. Regions of attached, separated, and vortical flow were noted on the wing and the leading edge flap using tufts and flow cones, and compared well with limited wind tunnel results

Summary of in-flight flow visualization obtained from the NASA high alpha research vehicle

A summary of the surface and off-surface flow visualization results obtained in flight on the F-18 high alpha research vehicle (HARV) is presented, highlighting the extensive 3-D vortical flow on the aircraft at angles of attack up to 50 degs. The emitted fluid technique, as well as tufts and flow cones, were used to document the surface flow. A smoke generator system injected smoke into the vortex cores generated by the forebody and leading edge extensions (LEXs). Documentation was provided by onboard still and video, by air-to-air, and by postflight photography. The surface flow visualization techniques revealed laminar separation bubbles near the forebody apex, lines of separation on the forebody and LEX, and regions of attached and separated flow on the wings and fins. The off-surface flow visualization techniques showed the path of the vortex cores on the forebody and LEX as well as the LEX vortex core breakdown location. An interaction between the forebody and LEX vortices was noted. The flow over the surfaces of the vertical tail was categorized into regions of attached, unsteady, or separated flow using flow tufts

Observations of the transfer of energy and momentum to the oceanic surface boundary layer beneath breaking waves

Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 1823-1837, doi:10.1175/JPO-D-15-0165.1.Measurements just beneath the ocean surface demonstrate that the primary mechanism by which energy from breaking waves is transmitted into the water column is through the work done by the covariance of turbulent pressure and velocity fluctuations. The convergence in the vertical transport of turbulent kinetic energy (TKE) balances the dissipation rate of TKE at first order and is nearly an order of magnitude greater than the sum of the integrated Eulerian and Stokes shear production. The measured TKE transport is consistent with a simple conceptual model that assumes roughly half of the surface flux of TKE by wave breaking is transmitted to depths greater than the significant wave height. During conditions when breaking waves are inferred, the direction of momentum flux is more aligned with the direction of wave propagation than with the wind direction. Both the energy and momentum fluxes occur at frequencies much lower than the wave band, consistent with the time scales associated with wave breaking. The largest instantaneous values of momentum flux are associated with strong downward vertical velocity perturbations, in contrast to the pressure work, which is associated with strong drops in pressure and upward vertical velocity perturbations.Funding for this research was provided by the National Science Foundation Grants OCE-1339032 and OCE-133851

Reference to index of records of letters from a Quaker, John H. Fisher, in Hobart to his brothers, 1842-1845

Letters from a Quaker, John H. Fisher, in Hobart to his brothers, Reuben A and Thomas W. in Cork, Ireland. John Fisher asked for news of his family, mentioning particularly his sisters May, Susanna and Margaret, Uncle John, cousins and friends and the other apprentices and he inquired if brother Thomas was still apprenticed to Henry Morris. His past misfortune was his own fault and he did not expect friend Thomas Harvey to forgive him and he wanted to know if the Friends Society had disowned him and how people he owed money to felt. He had not been much to the Friends Meeting House in Hobart -it was very different from home. Fisher had been in Port Philip and went into the bush but had an accident crossing the Goulburn River when a bullock dray ran over his legs and broke his thigh. In Hobart Isaac got him a job as overseer to David Lord but he was the only free person employed. Now he was working with Isaac who was teaching him hat making (1843) but in 1845 he wrote that hats could be imported more cheaply and Isaac was fell mongering --getting up wool for the English market. There was a depression in Hobart but his life was comfortable. Hobart had 4 insurance offices, 4 churches (2 English, 2 Scotch), a Catholic chapel, 4 dissenting houses and a Friends Meeting House. In his last letter, dated 11 November 1845, John Fisher says he is thinking of trying for Californian gold. One letter was later endorsed with a letter from A. Fisher to Thomas dated 31 .12 .1894 from Dymond City, N.C., enclosing the letters from their brother John and commenting on A.F.'s good life in the U.S.A., news of his children and his farm on which he still led an active life although both he and Thomas had "passed the three score and ten