Biased statistical learning of closed-class items

In natural languages, closed-class items predict open-class items but not the other way around. For example, in English, if there is a determiner there will be a noun, but nouns can occur with or without determiners. Here we asked whether statistical learning of closed-class items is also asymmetrical. In three experiments we exposed adults to a miniature language with the one-way dependency “if X then Y”: if X was present, Y was also present, but Y could occur without X. We created different versions of the language in order to ask whether learning depended on which category (X or Y) was an open or closed class. In one condition, X had the main properties of a closed class and Y had the main properties of an open class; in a contrasting condition, X had properties of an open class and Y had properties of a closed class. Learners’ exposure in these two conditions was otherwise identical. Learning was significantly better with closed-class X. Additional experiments demonstrated that it is the perceptual distinctiveness of closed-class items that drives learners to analyze them differently, and that the mathematical relationship between closed- and open-class items influences learning more strongly than their linear order. These results suggest that statistical learning is biased: learners privilege computations in which closed-class items are predictive of, rather than predicted by, open-class items. We suggest that the distributional asymmetries of closed-class items in natural languages—and perhaps the asymmetrical structure of linguistic representations—may arise in part from this learning bias.

Response Reduction Factor for Lateral Load Resisting Frames with Vertical Discontinuity of Asymmetrical Structure

In recent times, the RC building construction with vertical discontinuity that is floating column structures are unavoidable feature and increases trends day by day. To reduce lateral forces the earthquake resistance structures are designed so the response reduction factor (R) is used to determine these lateral forces by using base shear values. The R factor depends upon the overstrength factor, ductility factor, redundancy factor also the sizes of columns, types of soil, zones and load transferring path, etc. The IS code provides response reduction factor only for OMRF and SMRF along with other structures like Braced frame system, Structural wall system, Dual system, Flat slab structure wall system, etc. so there are no codal provisions for floating column structures. Thus it is essential to study the real behaviours of RC buildings with discontinuity in load transferring path through non-linear static analysis, so the present research work is done on trying to find R factor for vertical discontinuous asymmetrical structure for different soil conditions and different positions of floating column using moment resisting frames. And the structure is analyzed by response spectrum analysis and non-linear static analysis using SAP2000 software.

Quine’s Structural Holism and the Constitutive A Priori

Recent work on the structure of scientific theories has assigned a significant role to a priori principles in the formulation of scientific theories. For example, Michael Friedman has argued that theories possess an asymmetrical structure, with mathematical and logical principles presupposed in the very formulation of empirical laws. He further argues that Quine’s depiction of human knowledge as a ‘web of belief’, cannot capture this structure nor the constitutive role played by a priori principles in enabling the formulation of empirical statements and laws. This chapter argues that properly understood Quine’s ‘structural holism’ can capture this asymmetrical structure of scientific theories, but fails to address Friedman’s concern with constitutive a priori principles as coordinating the abstract mathematical component of scientific theories with sensible experience. However, once this difference is located in their different perspectives on scientific theories, the chapter argues that their views be seen as complementary rather than opposed.

A Novel Three-Phase Current Source Rectifier Based on an Asymmetrical Structure to Reduce Stress on Semiconductor Devices

This paper presents a novel three-phase current source rectifier (CSR) for AC/DC step-down voltage conversion to reduce voltage and current stress. The proposed converter features an asymmetrical connection between upper and lower arms compared with conventional CSRs, but has the same number of devices. With the proposed asymmetrical structure and modified space vector pulse width modulation (SVPWM) scheme, half of transistors only need to withstand half of the line-to-line voltage rather than the full line-to-line voltage, and its DC link current can be shared by multiple switches in freewheeling periods. Therefore, it is able to bring about a significant reduction in voltage and current stress, allowing for an improvement in the converter without additional cost. The topological structure, operation principles, and comparative analysis are specifically presented. Finally, an experimental prototype is built up to verify the performance of the proposed converter.

Sedimentological traces of ice-raft grounding in a Weichselian glacial lake near Dukuli (NE Latvia)

A clearly erosional, asymmetrical structure with a large concentration of unsorted clasts (ranging from gravel to boulder size) in its deepest point is present in Weichselian glaciolacustrine, mainly fine-grained sediments exposed in an outcrop near Dukuli (NE Latvia). No traces of currents that were sufficiently strong to be capable to erode the sediments significantly have been encountered in the sedimentary succession under study, and such currents would certainly not have been capable to transport boulder-sized clasts. Neither are traces present of mass movements that could deposit the boulder-sized clasts. The glaciolacustrine setting of the succession, the deep scouring and the high concentration of large clasts must therefore be ascribed to erosion of the lake bottom by the keel of an ice raft that became grounded and gradually melted; the debris that was carried along by the ice raft was released and concentrated at the deepest point of the depression that had been eroded by it.