Toggling the Switches

In this paper, I use Richard Lanham\u27s work within the field of rhetoric to explore the rhetorical implications of multilingualism and code switching. Specifically, I will discuss and question some of the basic assumptions of employing another language: What is at stake when we communicate with others in another language, especially native speakers? How might using an L2 language and recognizing/using different dialects within that language cause a speaker to reconsider their native tongue? What does the presence of numerous regional peculiarities and nonstandard varieties within languages say about our desire for ideal or standard speech

Engineering properties and construction guidelines for soil stabilized with self-cementing fly ash

Research was initiated to evaluate the engineering properties and to observe the short and long-term behavior of soil stabilized with self-cementing fly ash. Typically Iowa soils have low strength due to high fines content. Five Iowa soils ranging from ML to CH were used in this study as well as self-cementing fly ash from eight Iowa power plants. Fly ash addition had a profound effect on the compaction characteristics of the soils. The influences of fly ash content, moisture content, and compaction delay on compressive strength were observed for samples molded with ISU 2-in x 2-in apparatus as well as standard 4-inch diameter Proctor equipment. Long-term strength gain was evaluated for samples that were over 2.5 years old. California Bearing Ration (CBR) of fine-grained soils was also increased substantially with the addition of fly ash. Strength gain was also tested for samples cured in various environments. Freeze-thaw and wet-dry durability of soils were increased and reductions in plasticity characteristics were observed with fly ash addition. The morphology of soil-fly ash mixtures was studied as well as the clay mineralogy of the soils used in the study. In addition to the study of soil-fly ash mixtures, previous ISU research involving hydrated and conditioned fly ash was continued. The research utilized four sources of hydrated fly ash (HFA) and two sources of conditioned fly ash (CFA) from Iowa. Moisture content, curing temperature and time all had an impact on the strength gain of HFA and CFA. Shear strength parameter values for these materials were also determined. In addition to evaluating the strength of HFA and CFA alone, these two types of materials were also tested as soil stabilizers. The final part of research was to use the information determined in the previous tests to develop construction guidelines. Three construction guidelines were developed for use in Iowa. Two of these guidelines described the procedures for using HFA and CFA as select fill under pavement structures, while the third set of guidelines was developed for constructing sections of self-cementing fly ash stabilized soil

forall x: Calgary. An Introduction to Formal Logic

forall x: Calgary is a full-featured textbook on formal logic. It covers key notions of logic such as consequence and validity of arguments, the syntax of truth-functional propositional logic TFL and truth-table semantics, the syntax of first-order (predicate) logic FOL with identity (first-order interpretations), translating (formalizing) English in TFL and FOL, and Fitch-style natural deduction proof systems for both TFL and FOL. It also deals with some advanced topics such as truth-functional completeness and modal logic. Exercises with solutions are available. It is provided in PDF (for screen reading, printing, and a special version for dyslexics) and in LaTeX source code

Stable Deep MRI Reconstruction using Generative Priors

Data-driven approaches recently achieved remarkable success in magnetic resonance imaging (MRI) reconstruction, but integration into clinical routine remains challenging due to a lack of generalizability and interpretability. In this paper, we address these challenges in a unified framework based on generative image priors. We propose a novel deep neural network based regularizer which is trained in a generative setting on reference magnitude images only. After training, the regularizer encodes higher-level domain statistics which we demonstrate by synthesizing images without data. Embedding the trained model in a classical variational approach yields high-quality reconstructions irrespective of the sub-sampling pattern. In addition, the model shows stable behavior when confronted with out-of-distribution data in the form of contrast variation. Furthermore, a probabilistic interpretation provides a distribution of reconstructions and hence allows uncertainty quantification. To reconstruct parallel MRI, we propose a fast algorithm to jointly estimate the image and the sensitivity maps. The results demonstrate competitive performance, on par with state-of-the-art end-to-end deep learning methods, while preserving the flexibility with respect to sub-sampling patterns and allowing for uncertainty quantification

Economic thinking and risk attitudes: An empirical study

In the light of the current economic crisis, which had its roots in high risk dealings in the international financial markets, the question how economically minded students are and what propensity towards risk they have, are essential to improving their financial literacy. In a broad survey including economic and non-economic schools 649 students aged 14 and 18 were questioned. In this paper results are presented and implications for classroom teaching and curricular development are derived

Energy Storage Needs in Interconnected Systems Using the Example of Germany and Austria

The share of renewable energies on the net electricity consumption is rising steadily. Especially intermittent, non-controllable sources like wind and sun are gaining importance. With an installed amount of non-controllable power that exceeds the yearly peak load, situations can occur with a surplus of energy in electricity supply systems. This surplus will rise strongly with the share of fluctuating renewable energies on the net electricity consumption. A lot of studies and experts come to the conclusion that energy storage will be needed to handle these surpluses. The questions that still have to be answered are when and how. Especially the German electricity system will have very high storage needs because of a very strong and fast development of wind and solar power. There are a lot of technologies and approaches to overcome this problem. However, Pumped Hydro Energy Storage (PHES) systems are up to date the most efficient and economic bulk energy storage technology. On the one side there are no high potentials in natural sites for the installation of PHES schemes in Germany. On the other side the Austrian PHES system has still a very high potential. Up so far, the prospects are used just to a small amount. Especially the seasonal Hydro Energy Storage (HES) still holds a very high potential. In this paper the combination of the Austrian and the German energy supply system will be investigated with respect to the development of renewable energies. The overall energy storage needs are evaluated for each country as well as in the combined system, taking also into account the development and the influence of the transmission system capacity between the two countries