Geometric dynamics analysis of humanoids - locked inertia

The advantage of geometric dynamics analysis over most classical 3D analysis is that the equations are coordinate- neutral: as long as all quantities are expressed in the same coordinate frame, the equations are correct

Velocity control of a 2D dynamic walking robot

In this abstract we introduce velocity control for our 2D dynamic walking robot Dribbel [1] (figure 1) and show that, by ‘closing the loop’, this automatically leads to increased robustness

The reduction of the critical current in Nb3Sn cables under transverse loads

The degradation of the critical current of impregnated Rutherford type Nb3Sn cables was investigated as a function of the applied transverse load and magnetic field. The cable is made of modified jelly-roll-type strand material and has a keystone angle of 1.0°. The voltage-current characteristics were determined for the magnetic field ranging from 2 to 11 T and transverse pressure up to 250 MPa on the cable surface. It was found that the 48-strand cable, made of strands with six elements in the matrix, showed a larger critical current degradation than the 26-strand cable with 36 elements per strand. The global degradation of the 48-strand cable was 63% at 150 MPa, and 40% at 150 MPa for the 26-strand cable. Microanalysis of the cross-section before and after compression is presented, showing significant permanent damage to the superconducting strands

Зарубіжний досвід стимулювання розвитку малого та середнього бізнесу

У статті визначено основні сучасні центри ефективних технологій підтримки підприємництва, проведено аналіз особливостей державної політики розвитку малого та середнього бізнесу в США, визначено ефективні методи стимулювання розвитку малого та середнього бізнесу в умовах кризи.В статье определены основные современные центры эффективных технологий поддержки предпринимательства, проведен анализ особенностей государственной политики развития малого и среднего бизнеса в США, определены эффективные методы стимулирования развития малого и среднего бизнеса в условиях кризиса.In the article the main modern centers of effective technologies of supporting of business development are identified, the features of the state policy of small and medium businesses development in the U.S. are analyzed; most effective methods of stimulating of small and medium businesses development in conditions of crisis are identified

Heterogeneous relatedness and firm productivity

In this manuscript, we relate regional structural composition—related and unrelated variety—to firm-level productivity in European regions, applying a Cobb–Douglas production function framework and using firm-, industry- and regional-level mixed hierarchical (multilevel) models. Our analyses indicate that regional-related variety has a positive impact on firm productivity in European regions, especially for firms in high-tech and medium-tech regions. These outcomes have implications for European policies on competitiveness as firms embedded in regions without these technological and institutional circumstances are systematically worse off in terms of productivity, and catching-up is not obvious for such regional economies

Heterogeneous relatedness and firm productivity

In this manuscript, we relate regional structural composition—related and unrelated variety—to frm-level productivity in European regions, applying a Cobb–Douglas production function framework and using frm-, industry- and regional-level mixed hierarchical (multilevel) models. Our analyses indicate that regional-related variety has a positive impact on frm productivity in European regions, especially for frms in high-tech and medium-tech regions. These outcomes have implications for European policies on competitiveness as frms embedded in regions without these technological and institutional circumstances are systematically worse of in terms of productivity, and catching-up is not obvious for such regional economies

What is the market potential for on-demand services as a train station access mode?

Ride-hailing and other on-demand mobility services are often proposed as a solution for improving the accessibility of public transport by offering first/last mile connectivity. We study the potential of using on-demand services to improve train station access by means of a three-step sequential stated preference survey. We compare the preferences for on-demand services with the bicycle, car and public transport for accessing two alternative train stations at different access distances. We estimate a joint access mode and train station choice model. By estimating a latent class choice model, we uncover five distinct segments in the population. We describe the classes based on their stated preferences, travel behaviour, attitudes towards new mobility and their socio-demographic characteristics. The two largest classes, accounting for over half of the sample, are the most likely to adopt on-demand services. Having an average willingness-to-pay, they would choose these services for longer access distances, competing mainly with the car and local public transport. Applying the model estimates, we observe that while on-demand services mainly compete with public transportation (obtaining most of its travellers from it), they are not able to fully substitute a public transport service for train station access, as many users would switch to cycling or driving a car, rather than opting for the on-demand service

Potential of on-demand services for urban travel

On-demand mobility services are promising to revolutionise urban travel, but preliminary studies are showing that they may actually increase the total vehicle miles travelled, thereby worsening road congestion in cities. In this study, we assess the demand for on-demand mobility services in urban areas, using a stated preference survey, to understand the potential impact of introducing on-demand services on the current modal split. The survey was carried out in the Netherlands and offered respondents a choice between bike, car, public transport and on-demand services. 1,063 valid responses are analysed with a multinomial logit and a latent class choice model. By means of the latter, we uncover four distinctive groups of travellers based on the observed choice behaviour. The majority of the sample (55%) are avid cyclists and do not see on-demand mobility as an alternative for making urban trips. Two classes (27% and 9% of the sample) would potentially use on-demand services: the former is fairly time-sensitive and would thus use on-demand service if they were sufficiently fast. The latter class however is highly cost-sensitive, and would therefore use on-demand mobility primarily if it is cheap. The fourth class (9%) shows very limited potential for using on-demand services