Free vibration analysis of laminated composite plates based on FSDT using one-dimensional IRBFN method

This paper presents a new effective radial basis function (RBF) collocation technique for the free vibration analysis of laminated composite plates using the first order shear deformation theory (FSDT). The plates, which can be rectangular or non-rectangular, are simply discretised by means of Cartesian grids. Instead of using conventional differentiated RBF networks, one-dimensional integrated RBF networks (1D-IRBFN) are employed on grid lines to approximate the field variables. A number of examples concerning various thickness-to-span ratios, material properties and boundary conditions are considered. Results obtained are compared with the exact solutions and numerical results by other techniques in the literature to investigate the performance of the proposed method

The Secondary-Rights Approach to the ‘Common Intention Constructive Trust’

Unlike ‘primary rights’ constructive trust doctrines, the CICT affords courts a wide discretion in determining the appropriate remedy in a particular case. This paper suggests that the CICT can take a step towards conceptual and analytical coherence if approached as a device for courts to award remedies that give effect to A’s secondary rights. When B breaches his primary duty to ensure A does not suffer harm from the unreliability of his induced assumptions, and when this causes A to suffer detrimental reliance, A obtains an unliquidated secondary right to be compensated for any harm, and a judge has discretion to determine the appropriate content of the remedy to compensate A for harm suffered. Since this approach is highly similar to proprietary estoppel, assimilating the CICT within proprietary estoppel can further benefit our understanding and practice of resolving disputes in the family homes context

Dormancy in reproductive vegetative buds in creeping perennials dominating the agricultural weed flora in Scandinavia

Dormancy, which is the inability to initiate normal growth under otherwise favourable conditions, is an adaptation to escape sprouting prior to seasonal cold temperatures and/or drought in areas where winters are harsh or summers dry. Dormancy in woody perennials of northern temperate areas is, in general, induced by photoperiodic and/or temperature changes, and released after prolonged exposure to chilling. Besides being species specific, northern ecotypes are usually more sensitive to inductive signals than are southern ecotypes (in cold temperate areas). Dormancy in perennial weeds has been little studied, but might influence the effect of weed control measures. These often involve repeated fragmentation of the roots or rhizomes to stimulate re-sprouting, thus reducing the storage of nutrient reserves. Such measures would be a waste of energy and time if conducted during a period of dormancy. Furthermore, herbicide applications might be less efficient, since there is no or little transport to reproductive organs. In this thesis, the autumnal growth pattern of five perennial weeds, which all propagate vegetatively from underground adventitious or axillary buds, has been studied. In an outdoor pot experiment, emergence from defoliated plants with undisturbed underground systems was followed at two weeks intervals from late July to late January/April, for 2 years. During the second year, sprouting capacity from root and rhizome fragments was also tested. Emergence was impaired in Cirsium arvense, Equisetum arvense, Sonchus arvensis and Tussilago farfara during a period in September-October. This seasonality was, however, not preserved in C. arvense root buds after fragmentation of the root system. Fragmented rhizomes of Elytrigia repens, originating from southern Sweden, sprouted less readily in September-October. The shoot-to-rhizome ratio of this species was lowest during the same period. A climate chamber experiment suggested a photoperiodic control of sprouting from fragments of S. arvensis, with least sprouting in short photoperiods (12 h of light) combined with high temperature. None of the 12 combinations of photoperiods and temperatures used induced dormancy in C. arvense. In neither of the experiments could timing of dormancy onset be attributed to the latitudinal origin of the plants

Gamma-ray line from radiative decay of gravitino dark matter

We study radiative decay of gravitino dark matter with trilinear R-parity violations. We show that the branching ratio of the decay of gravitino into monochromatic photon can be large enough to explain the observed gamma-ray line from the Galactic centre in the Fermi-LAT data without producing too much continuum gamma-ray and anti-proton flux. This scenario is realized when the mass of sfermions and the trilinear R-parity violating coupling are $O(1-10)$ TeV and $O(10^{-7}-10^{-6})$ respectively.Comment: 10 pages, 1 figure; added references, modified figure, expanded discussions, published versio

Buckling and vibration analysis of laminated composite plate/shell structures via a smoothed quadrilateral flat shell element with in-plane rotations

This paper presents buckling and free vibration analysis of composite plate/shell structures of various shapes, modulus ratios, span-to-thickness ratios, boundary conditions and lay-up sequences via a novel smoothed quadrilateral flat element. The element is developed by incorporating a strain smoothing technique into a flat shell approach. As a result, the evaluation of membrane, bending and geometric stiffness matrices are based on integration along the boundary of smoothing elements, which leads to accurate numerical solutions even with badly-shaped elements. Numerical examples and comparison with other existing solutions show that the present element is efficient, accurate and free of locking

Productivity-wage-growth nexus: an empirical study of Singapore

This paper investigates the empirical relationship between labor productivity, real wages and real GDP in Singapore from 1997 to 2011. The paper begins with a review of productivity, wage and growth situations in Singapore in the past decade and further attempts to uncover the underlying relationship in this nexus using theoretical framework from labor and growth literature. Using the Vector-Autoregressive or Vector-Error Correction Mechanism when cointegration is present, this paper uncovers various causality relations in different industries which conform to economic theory and empirics. An impulse response analysis is also undertaken to understand how specific policy decisions could be framed to provide for higher wages across industries. The empirical results suggest that in the Singapore economy, there exist a bi-directional causality relation between labor productivity and real GDP but that wages seem to be caused by other underlying factors. However, real wages respond positively to positive shocks in the real GDP or labor productivity using cholesky or generalized decomposition. This paper concludes by discussing policies that could be undertaken to promote inclusive growth in the environment of sustained economic growth.Causality, Productivity, Wage, Economic Growth, Singapore

Space-Time Trellis and Space-Time Block Coding Versus Adaptive Modulation and Coding Aided OFDM for Wideband Channels

Abstract—The achievable performance of channel coded spacetime trellis (STT) codes and space-time block (STB) codes transmitted over wideband channels is studied in the context of schemes having an effective throughput of 2 bits/symbol (BPS) and 3 BPS. At high implementational complexities, the best performance was typically provided by Alamouti’s unity-rate G2 code in both the 2-BPS and 3-BPS scenarios. However, if a low complexity implementation is sought, the 3-BPS 8PSK space-time trellis code outperfoms the G2 code. The G2 space-time block code is also combined with symbol-by-symbol adaptive orthogonal frequency division multiplex (AOFDM) modems and turbo convolutional channel codecs for enhancing the system’s performance. It was concluded that upon exploiting the diversity effect of the G2 space-time block code, the channel-induced fading effects are mitigated, and therefore, the benefits of adaptive modulation erode. In other words, once the time- and frequency-domain fades of the wideband channel have been counteracted by the diversity-aided G2 code, the benefits of adaptive modulation erode, and hence, it is sufficient to employ fixed-mode modems. Therefore, the low-complexity approach of mitigating the effects of fading can be viewed as employing a single-transmitter, single-receiver-based AOFDM modem. By contrast, it is sufficient to employ fixed-mode OFDM modems when the added complexity of a two-transmitter G2 scheme is affordable