11,259 research outputs found
Low frequency shelf current fluctuations in the Gulf of Alaska
Thesis (M.S.) University of Alaska Fairbanks, 1977A general oceanographic study of a shelf region in the Gulf of Alaska has revealed low-frequency, current fluctuations. A current meter mooring was located approximately 20 km offshore, in a water depth of 100 m. The time dependent flow is found to be baroclinic and semi-periodic. The effects of local bottom topography, nearshore dilution by river discharge, orographic coastal features, and an island barrier are important to the shelf circulation in this region. The movement of a boundary associated with the Copper River appears to be an important process in controlling the water motion at the mooring site
Wikis in Tuple Spaces
We consider storing the pages of a wiki in a tuple space and the effects this
might have on the wiki experience. In particular, wiki pages are stored in
tuples with a few identifying values such as title, author, revision date,
content, etc. and pages are retrieved by sending the tuple space templates,
such as one that gives the title but nothing else, leaving the tuple space to
resolve to a single tuple. We use a tuple space wiki to avoid deadlocks,
infinite loops, and wasted efforts when page edit contention arises and examine
how a tuple space wiki changes the wiki experience.Comment: To appear at WMSCI 200
Large space structures testing
There is considerable interest in the development of testing concepts and facilities that accurately simulate the pathologies believed to exist in future spacecraft. Both the Government and Industry have participated in the development of facilites over the past several years. The progress and problems associated with the development of the Large Space Structure Test Facility at the Marshall Flight Center are presented. This facility was in existence for a number of years and its utilization has run the gamut from total in-house involvement, third party contractor testing, to the mutual participation of other Government Agencies in joint endeavors
CtBP impedes JNK- and Upd/STAT-driven cell fate misspecifications in regenerating Drosophila imaginal discs.
Regeneration following tissue damage often necessitates a mechanism for cellular re-programming, so that surviving cells can give rise to all cell types originally found in the damaged tissue. This process, if unchecked, can also generate cell types that are inappropriate for a given location. We conducted a screen for genes that negatively regulate the frequency of notum-to-wing transformations following genetic ablation and regeneration of the wing pouch, from which we identified mutations in the transcriptional co-repressor C-terminal Binding Protein (CtBP). When CtBP function is reduced, ablation of the pouch can activate the JNK/AP-1 and JAK/STAT pathways in the notum to destabilize cell fates. Ectopic expression of Wingless and Dilp8 precede the formation of the ectopic pouch, which is subsequently generated by recruitment of both anterior and posterior cells near the compartment boundary. Thus, CtBP stabilizes cell fates following damage by opposing the destabilizing effects of the JNK/AP-1 and JAK/STAT pathways
Small deflection of a class of clamped thin plates using collocation
Equations are given for the optimization of a class of two-and three-dimensional structures. The application of existing analytical techniques to the response of thin clamped plates is described. The ratios of deflections to plate thickness are given for uniform transverse loads as well as for uniform plus linearly varying transverse loads. Deflections are presented at angular increments of 5 degrees and at radial increments of 0.1 of the radius
Robustness to fundamental uncertainty in AGI alignment
The AGI alignment problem has a bimodal distribution of outcomes with most outcomes clustering around the poles of total success and existential, catastrophic failure. Consequently, attempts to solve AGI alignment should, all else equal, prefer false negatives (ignoring research programs that would have been successful) to false positives (pursuing research programs that will unexpectedly fail). Thus, we propose adopting a policy of responding to points of metaphysical and practical uncertainty associated with the alignment problem by limiting and choosing necessary assumptions to reduce the risk false positives. Herein we explore in detail some of the relevant points of uncertainty that AGI alignment research hinges on and consider how to reduce false positives in response to them
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