The large range of deformations of ionic polymer metal composites (IPMCs) has often been proposed as a key advantage of these soft active materials. Nevertheless, many applications in soft robotics still cannot be addressed by current IPMC technology, demanding an even wider deformation range. Here, we empirically demonstrate the feasibility of integrating electrostatic actuation to enhance IPMC deformations. Through the use of external contactless electrodes, an electrostatic pressure is generated on the IPMC, thereby magnifying the deformation elicited by the small voltage applied across its electrodes. A mathematical model is established to predict the onset of the pull-in instability, which defines when electrostatic actuation can be effectively utilized to enhance IPMC performance.

Flexural elastic waves and sound in solids are of great interest in wide-ranging contexts such as ultrasound in plates, geophysics, ocean engineering, aerospace and automotive structures, and musical acoustics. Despite bending waves being the most important elastic waves for such surface structures, their propagation in the presence of the inevitable non-uniformity is poorly understood. Here we show the branching and focusing behaviour of highly dispersive flexural waves travelling in elastic plates of non-uniform thickness. The thickness profile has isotropically correlated spatial randomness. The correlation length is much larger than the wavelength. The location of wave focusing shows a scaling relationship with randomness, which is consistent with those previously reported in other random media. We show this analytically and numerically. This suggests a universality in the scaling between the location of wave focusing with randomness and the correlation length, regardless of the physics of the waves in question.

The vibration of a homogeneous circular membrane backed by two taut strings is shown to yield several harmonic overtones for a wide range of physical and geometric parameters. Such a membrane is present at each end of the barrel of an idakkā, an Indian snare drum well known for its rich musicality. The audio recordings of the musical drum are analyzed and a case is made for the strong sense of pitch associated with the drum. A computationally inexpensive model of the string-membrane interaction is proposed assuming the strings to be without inertia. The interaction essentially entails wrapping/unwrapping of the string around a curve on the deforming membrane unlike the colliding strings in Western snare drums. The range of parameters for which harmonicity is achieved is examined and is found to be conforming with what is used in actual drum playing and construction.

Unsupervised word alignments offer a lightweight and interpretable method to transfer labels from high-to low-resource languages, as long as semantically related words have the same label across languages. But such an assumption is often not true in industrial NLP pipelines, where multilingual annotation guidelines are complex and deviate from semantic consistency due to various factors (such as annotation difficulty, conflicting ontology, upcoming feature launches etc.); We address this difficulty by constraining the alignment model to remain consistent with both source and target annotation guidelines, leveraging posterior regularization and labeled examples. We illustrate the overall approach using IBM 2 (fast_align) as a base model, and report results on both internal and external annotated datasets. We measure consistent accuracy improvements on the MultiATIS++ dataset over AWESoME, a popular transformer-based alignment model, in the label projection task (+2.7% at word-level and +15% at sentence-level), and show how even a small amount of target language annotations helps substantially.

A foundation gives the overall strength to a building by providing a level surface for the building to stand and distributing the total load uniformly to the underlying soil. The type of foundation to be chosen varies with the foundation soil and site conditions. Piled raft system are a type of foundation preferred when the bearing strata has less soil bearing capacity and a huge load has to be transferred. Thus Piled raft foundation is a foundation system which uses the combined effects of both rafts and piles such that it is expected to transfer huge loads without large settlement. An ample evaluation of factors like number of piles, length of piles, and degree of compaction of soil that affects the performance of the foundation is required, to understand the concept of piled raft foundation. This study was based on the behaviour of vertically loaded piled raft system by varying the length of pile as 100 mm, 150 mm and 200 mm with 4 and 9 numbers of pile conducted on loose and dense state in cohesion less soil. A vertical load test was conducted on unpiled raft both in loose and dense state of soil also and the results obtained from both piled and unpiled rafts were compared together. The compared results indicated an improvement in ultimate load capacity and settlement reduction. A settlement reduction of 32.71% and increased bearing capacity of 63.67% were observed when compared to unpiled raft under dense condition. About 84% of increase in bearing capacity of the piled raft system was observed with varying the degree of compaction of soil from loose to dense state of soil. An optimum design of this piled raft foundation can provide an alternative foundation for high rise buildings, transmission towers, bridges etc. and it can provide an aid to the threat of differential settlement for heavy loaded buildings in poor bearing strata.