The NC-REN meets the North Carolina Information Highway

The North Carolina Research and Education Network (NC-REN), formerly known as CONCERT, is an existing video and data network, owned and operated by MCNC. NC-REN's purpose has been to provide network-based support for collaboration in the research community within the state since 1985. The first major application planned for the North Carolina Information Highway (NCIH) is an interactive video distance learning system. A secondary application proposed is the use of Switched Multimegabit Data Service (SMDS) as a means of providing data communications services over NCIH. The user community currently supported by NC-REN has come to expect high levels of service, reliability, interoperability and performance for data and video communications. MCNC is committed to see that NC-REN users receive service that is equal to or better than what is currently provided by the existing network. The prospect of migrating NC-REN-provided services to NCIH-provided transport has raised challenging technical and unique service issues     

The threat of optical communications

Research shows that the future capability of optical communication technology vastly exceeds the use that we make of it today. The result is that opportunities are now opening up to completely bypass large parts of established telecommunication networks with immensely powerful new networks having very different properties to the long-established ones. `Free' bandwidth may soon be a near reality with major consequences for today's network operators     

Calculation of the parameters of evacuation systems for tanks with a liquid-gas ejector

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 6, pp. 13–15, June, 1993.     

Analysis of interfacial failure in a composite microbundle pull-out experiment

Modeling of the failure of polymer-matrix composites requires substantial information about the mechanisms of failure at the interface, and load redistribution around fiber breaks in the composite. Current interface experiments involving the use of ‘microcomposites’ of single embedded fibers in a matrix generally do not include all the key geometric features of the real composite; in particular, they do not include the effects of fiber volume fraction and the higher matrix shear resulting from closely neighboring fibers. A new experiment was recently devised to assess some of these effects: it is referred to as the single-fiber pull-out from microbundle (SFPOM) experiment. It consists of a hexagonal arrat of seven fibers in a matrix where the outer six fibers are restrained and the center fiber is pulled out. Recent experimental data from tests with this geometry are analyzed here using three mechanical models of the failure process, and parametric studies of the data are performed to assess the appropriateness of each model. Two of the models, based on fracture energy considerations as applied earlier to single embedded fibers in a matrix and adapted to our geometry, were found to model data from the SFPOM experiments poorly. The third model assumes the existence of three zones near a fiber break, including elastic, plastic and frictional debond zones, and was found to provide reasonable fit to the data under realistic assumptions.     

Thoughts on the constructions of maternal representations.

Discusses the deconstructive shift in the conception of mothers and mothering from a unitary category of women in a biological relationship with their offspring to a more fluid constellation of active maternal relations. The author suggests a new parenting subject that transcends gender, constructed through the work of intersubjective dyads. Two questions are addressed: (1) How might the representation of such maternal relationships and their internalization be envisioned? (2) How might a changing conception of internalized maternal representations affect psychoanalytic practice? With reference to J. Bowlby's (1980) concept of internal working models of attachment, and to more recent infant research, the concept of maternal functions (specifically, functions of security, regulation, and recognition) is introduced as central to the mothering relation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A micromechanics model for the prediction of static strength of off-axis unidirectional laminates

In this paper a micromechanics model using the concentric cylinder assemblage model and the Mori-Tanaka average stress scheme is used to predict the static strength of unidirectional angle ply laminates. The predicted strengths agree with experimental results for Glass/Epoxy and Graphite/Epoxy systems.     

An improved code density test for the dynamic characterization offlash A/D converters

An improved code density test for flash A/D converters is proposed, revealing some dynamic phenomena (e.g., missing codes) hidden by the conventional approach. Formulas are reported for obtaining, from code density, effective noise estimates fully consistent with those provided by waveform analysis. Finally, it is shown that the variance of noise estimates obtained by time-domain analysis may be unacceptably large if the observation window is not properly chosen