Forecast analysis of optical waveguide bus performance

Elements to be considered in the design of a data bus include: architecture; data rate; modulation, encoding, detection; power distribution requirements; protocol, work structure; bus reliability, maintainability; interterminal transmission medium; cost; and others specific to application. Fiber- optic data bus considerations for a 32 port transmissive star architecture, are discussed in a tutorial format. General optical-waveguide bus concepts, are reviewed. The electrical and optical performance of a 32 port transmissive star bus, and the effects of temperature on the performance of optical-waveguide buses are examined. A bibliography of pertinent references and the bus receiver test results are included

TB108: Chemical and Physical Properties of the Becket, Colton, Finch, Lyman, Masardis, Naumburg, and Skerry Soil Mapping Units

Soil morphology and soil characterization studies were done on seven soil mapping units in Maine. Soil profiles were selected, described and sampled jointly by soil scientists from the Soil Conservation Service, USDA and the Maine Agricultural Experiment Station. Chemical and physical measurements of each soil mapping unit were made in the laboratory. Soil profile description and the laboratory determinations are presented for each sample site.https://digitalcommons.library.umaine.edu/aes_techbulletin/1092/thumbnail.jp

A novel non-Fermi-liquid state in the iron-pnictide FeCrAs

We report transport and thermodynamic properties of stoichiometric single crystals of the hexagonal iron-pnictide FeCrAs. The in-plane resistivity shows an unusual "non-metallic" dependence on temperature T, rising continuously with decreasing T from ~ 800 K to below 100 mK. The c-axis resistivity is similar, except for a sharp drop upon entry into an antiferromagnetic state at T_N 125 K. Below 10 K the resistivity follows a non-Fermi-liquid power law, rho(T) = rho_0 - AT^x with x<1, while the specific heat shows Fermi liquid behaviour with a large Sommerfeld coefficient, gamma ~ 30 mJ/mol K^2. The high temperature properties are reminiscent of those of the parent compounds of the new layered iron-pnictide superconductors, however the T -> 0 properties suggest a new class of non-Fermi liquid.Comment: 6 pages, 4 figure

Topological Modes in Dual Lattice Models

Lattice gauge theory with gauge group $Z_{P}$ is reconsidered in four dimensions on a simplicial complex $K$. One finds that the dual theory, formulated on the dual block complex $\hat{K}$, contains topological modes which are in correspondence with the cohomology group $H^{2}(\hat{K},Z_{P})$, in addition to the usual dynamical link variables. This is a general phenomenon in all models with single plaquette based actions; the action of the dual theory becomes twisted with a field representing the above cohomology class. A similar observation is made about the dual version of the three dimensional Ising model. The importance of distinct topological sectors is confirmed numerically in the two dimensional Ising model where they are parameterized by $H^{1}(\hat{K},Z_{2})$.Comment: 10 pages, DIAS 94-3

I\u27d Like To Meet Your Father

https://digitalcommons.library.umaine.edu/mmb-vp/1741/thumbnail.jp

Methodological Issues in the Content Analysis of Computer Conference Transcripts

This paper discusses the potential and the methodological challenges of analyzing computer conference transcripts using quantitative content analysis. The paper is divided into six sections, which discuss: criteria for content analysis, research designs, types of content, units of analysis, ethical issues, and software to aid analysis. The discussion is supported with a survey of 19 commonly referenced studies published during the last decade. The paper is designed to assist researchers in using content analysis to further the understanding of teaching and learning using computer conferencing

Assessing Social Presence In Asynchronous Text-based Computer Conferencing

Instructional media such as computer conferencing engender high levels of student-student and student-teacher interaction; affectively into a community of inquiry. A template for assessing social presence in computer conferencing is presented through content analysis of conferencing transcripts. To facilitate explication of the scheme and subsequent replication of this study, selections of coded transcripts are included, along with interrater reliability figures. The article concludes with a discussion of the implications and benefits of assessing social presence for instructors, for instructors, conference moderators, and researchers

On the Expansions in Spin Foam Cosmology

We discuss the expansions used in spin foam cosmology. We point out that already at the one vertex level arbitrarily complicated amplitudes contribute, and discuss the geometric asymptotics of the five simplest ones. We discuss what type of consistency conditions would be required to control the expansion. We show that the factorisation of the amplitude originally considered is best interpreted in topological terms. We then consider the next higher term in the graph expansion. We demonstrate the tension between the truncation to small graphs and going to the homogeneous sector, and conclude that it is necessary to truncate the dynamics as well.Comment: 17 pages, 4 figures, published versio