A hierarchical time-splitting approach for solving finite-time optimal control problems

We present a hierarchical computation approach for solving finite-time optimal control problems using operator splitting methods. The first split is performed over the time index and leads to as many subproblems as the length of the prediction horizon. Each subproblem is solved in parallel and further split into three by separating the objective from the equality and inequality constraints respectively, such that an analytic solution can be achieved for each subproblem. The proposed solution approach leads to a nested decomposition scheme, which is highly parallelizable. We present a numerical comparison with standard state-of-the-art solvers, and provide analytic solutions to several elements of the algorithm, which enhances its applicability in fast large-scale applications

Observation of edge waves in a two-dimensional Su-Schrieffer-Heeger acoustic network

In this work, we experimentally report the acoustic realization the two-dimensional (2D) Su-Schrieffer-Heeger (SSH) model in a simple network of air channels. We analytically study the steady state dynamics of the system using a set of discrete equations for the acoustic pressure, leading to the 2D SSH Hamiltonian matrix without using tight binding approximation. By building an acoustic network operating in audible regime, we experimentally demonstrate the existence of topological band gap. More supremely, within this band gap we observe the associated edge waves even though the system is open to free space. Our results not only experimentally demonstrate topological edge waves in a zero Berry curvature system but also provide a flexible platform for the study of topological properties of sound waves

Job flows, returns to skill, and rent-sharing at the dawn of the new millennium: A firm-level inquiry from the BRICS

We present a firm-level inquiry on labour-demand characteristics in the BRICS economies, using standardized data from the World Bank Enterprise Surveys for the pre-crisis period of 2002-2003. The BRICS countries are the growth champions of that period, with numerous discussions on the effect of growth on inequality and the role of skills on labour-market performance. We examine employment, employment growth and its constituents, as well the returns to skill and the incidence of rent-sharing. We find that SMEs in the BRICS exhibit lower gross employment growth, compared to large firms. Large firms in Brazil, Russia and South Africa are responsible for most of the net job creation. In contrast, small and medium firms in China and India exhibit higher net job creation rates compared to large firms. Younger firms in Brazil, Russia and India generate higher net job creation figures, in contrast to China and South Africa, in which it is the large firms that generate more net new jobs. Foreign firms in China exhibit the highest net job creation, while in Brazil and India domestic firms create most of the new net employment. Private firms are responsible for most of the net job creation and job reallocation in all BRICS counties. The returns to skill are lower in SMEs and young firms, and we find evidence in favour of rent sharing, particularly in Brazil and India, by foreign and exporting firms, and by SMEs in China

Job flows, returns to skill, and rent-sharing at the dawn of the new millennium: A firm-level inquiry from the BRICS

We present a firm-level inquiry on labour-demand characteristics in the BRICS economies, using standardized data from the World Bank Enterprise Surveys for the pre-crisis period of 2002-2003. The BRICS countries are the growth champions of that period, with numerous discussions on the effect of growth on inequality and the role of skills on labour-market performance. We examine employment, employment growth and its constituents, as well the returns to skill and the incidence of rent-sharing. We find that SMEs in the BRICS exhibit lower gross employment growth, compared to large firms. Large firms in Brazil, Russia and South Africa are responsible for most of the net job creation. In contrast, small and medium firms in China and India exhibit higher net job creation rates compared to large firms. Younger firms in Brazil, Russia and India generate higher net job creation figures, in contrast to China and South Africa, in which it is the large firms that generate more net new jobs. Foreign firms in China exhibit the highest net job creation, while in Brazil and India domestic firms create most of the new net employment. Private firms are responsible for most of the net job creation and job reallocation in all BRICS counties. The returns to skill are lower in SMEs and young firms, and we find evidence in favour of rent sharing, particularly in Brazil and India, by foreign and exporting firms, and by SMEs in China

Job flows, returns to skill, and rent-sharing at the dawn of the new millennium: A firm-level inquiry from the BRICS

We present a firm-level inquiry on labour-demand characteristics in the BRICS economies, using standardized data from the World Bank Enterprise Surveys for the pre-crisis period of 2002-2003. The BRICS countries are the growth champions of that period, with numerous discussions on the effect of growth on inequality and the role of skills on labour-market performance. We examine employment, employment growth and its constituents, as well the returns to skill and the incidence of rent-sharing. We find that SMEs in the BRICS exhibit lower gross employment growth, compared to large firms. Large firms in Brazil, Russia and South Africa are responsible for most of the net job creation. In contrast, small and medium firms in China and India exhibit higher net job creation rates compared to large firms. Younger firms in Brazil, Russia and India generate higher net job creation figures, in contrast to China and South Africa, in which it is the large firms that generate more net new jobs. Foreign firms in China exhibit the highest net job creation, while in Brazil and India domestic firms create most of the new net employment. Private firms are responsible for most of the net job creation and job reallocation in all BRICS counties. The returns to skill are lower in SMEs and young firms, and we find evidence in favour of rent sharing, particularly in Brazil and India, by foreign and exporting firms, and by SMEs in China