3,670 research outputs found
Method of recertifying a loaded bearing member
A method is described of recertifying a loaded bearing member using ultrasound testing to compensate for different equipment configurations and temperature conditions. The standard frequency F1 of a reference block is determined via an ultrasonic tone burst generated by a first pulsed phased locked loop (P2L2) equipment configuration. Once a lock point number S is determined for F1, the reference frequency F1a of the reference block is determined at this lock point number via a second P2L2 equipment configuration to permit an equipment offset compensation factor Fo1=((F1-F1a)/F1)(1000000) to be determined. Next, a reference frequency F2 of the unloaded bearing member is determined using a second P2L2 equipment configuration and is then compensated for equipment offset errors via the relationship F2+F2(Fo1)/1000000. A lock point number b is also determined for F2. A resonant frequency F3 is determined for the reference block using a third P2L2 equipment configuration to determine a second offset compensation factor F02=((F1-F3)/F1) 1000000. Next the resonant frequency F4 of the loaded bearing member is measured at lock point number b via the third P2L2 equipment configuration and the bolt load determined by the relationship (-1000000)CI(((F2-F4)/F2)-Fo2), wherein CI is a factor correlating measured frequency shift to the applied load. Temperature compensation is also performed at each point in the process
Toward a Neo-Schumpeterian Theory of the Firm
This paper offers a sketch of what an economic theory of the firm would look like if it were founded on the thought of Joseph Schumpeter, particularly on Chapters 1-2 of his Theory of Economic Development. Schumpeterian analysis requires an intuitively appealing and realistic conceptualization of the distinction between routine and innovative behavior, and in particular, a conceptualization relevant to complex organizations and complex tasks. It is argued that the production theory found in mainstream economics does not meet this requirement, particularly because its characterization of productive knowledge involves an overly sharp distinction between “technically possible” and “technically impossible” – a distinction which has no counterpart in the realities of organizational knowledge. The main elements of a Schumpeterian view are described and contrasted with those in the mainstream view.Theory of the firm, Schumpeter, Innovation, Knowledge
Ten Billion Years of Galaxy Evolution
Observations in the Hubble Deep Fields have been used to study the evolution
of galaxy morphology over time. The majority of galaxies with z < 1 are seen to
be disk like, whereas most objects with z > 2 appear to be either chaotic or
centrally concentrated ``blobs''. Such blobs might be the ancestral objects of
ellipticals or of galaxy bulges. About 1/3 of objects with z > 2 appear to be
in the process of merging. The region with 1 < z < 2 marks an important
transition in the global history of star formation from a merger dominated
regime at z > 2, to one at z < 1 in which most star formation takes place in
galactic disks. It is speculated that the break in the Madau plot at z sim 1.5
might be related to the transition from merger-dominated star formation at z >
2 to disk-dominated star formation at at z < 1.Comment: 19 pages. 1 figure. To be published in the August 2002 issue of PAS
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