2,611 research outputs found
Efficient Jacobian-Based Inverse Kinematics With Sim-to-Real Transfer of Soft Robots by Learning
This article presents an efficient learning-based method to solve the <italic>inverse kinematic</italic> (IK) problem on soft robots with highly nonlinear deformation. The major challenge of efficiently computing IK for such robots is due to the lack of analytical formulation for either forward or inverse kinematics. To address this challenge, we employ neural networks to learn both the mapping function of forward kinematics and also the Jacobian of this function. As a result, Jacobian-based iteration can be applied to solve the IK problem. A sim-to-real training transfer strategy is conducted to make this approach more practical. We first generate a large number of samples in a simulation environment for learning both the kinematic and the Jacobian networks of a soft robot design. Thereafter, a sim-to-real layer of differentiable neurons is employed to map the results of simulation to the physical hardware, where this sim-to-real layer can be learned from a very limited number of training samples generated on the hardware.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Materials and ManufacturingMechatronic Desig
Alpha particle spectroscopy using FNTD and SIM super-resolution microscopy
Structured illumination microscopy (SIM) for the imaging of alpha particle tracks in fluorescent nuclear track detectors (FNTD) was evaluated and compared to confocal laser scanning microscopy (CLSM). FNTDs were irradiated with an external alpha source and imaged using both methodologies. SIM imaging resulted in improved resolution, without increase in scan time. Alpha particle energy estimation based on the track length, direction and intensity produced results in good agreement with the expected alpha particle energy distribution. A pronounced difference was seen in the spatial scattering of alpha particles in the detectors, where SIM showed an almost 50% reduction compared to CLSM. The improved resolution of SIM allows for more detailed studies of the tracks induced by ionising particles. The combination of SIM and FNTDs for alpha radiation paves the way for affordable and fast alpha spectroscopy and dosimetry. Journal compilatio
A simple disc wind model for broad absorption line quasars
Approximately 20 per cent of quasi-stellar objects (QSOs) exhibit broad, blue-shifted absorption lines in their ultraviolet spectra. Such features provide clear evidence for significant outflows from these systems, most likely in the form of accretion disc winds. These winds may represent the ‘quasar’ mode of feedback that is often invoked in galaxy formation/evolution models, and they are also key to unification scenarios for active galactic nuclei (AGN) and QSOs. To test these ideas, we construct a simple benchmark model of an equatorial, biconical accretion disc wind in a QSO and use a Monte Carlo ionization/radiative transfer code to calculate the ultraviolet spectra as a function of viewing angle. We find that for plausible outflow parameters, sightlines looking directly into the wind cone do produce broad, blue-shifted absorption features in the transitions typically seen in broad absorption line (BAL) QSOs. However, our benchmark model is intrinsically X-ray weak in order to prevent overionization of the outflow, and the wind does not yet produce collisionally excited line emission at the level observed in non-BAL QSOs. As a first step towards addressing these shortcomings, we discuss the sensitivity of our results to changes in the assumed X-ray luminosity and mass-loss rate, Ṁwind. In the context of our adopted geometry, Ṁwind ∼ Ṁacc is required in order to produce significant BAL features. The kinetic luminosity and momentum carried by such outflows would be sufficient to provide significant feedback
Connecticut State Innovation Model (SIM); Proposed framework--revised 4/30/19
1 online resource (32 pages) : color illustrationsFinal version; "This report was prepared by Health Management Associates (HMA), a leading independent national research and consulting firm"--Page 3; "The project described was supported by Funding Opportunity Number CMS-1G1CMS331630-02-00 from the U.S. Department of Health & Human Services, Centers for Medicare & Medicaid Services."; "Approved June 2019."; Includes bibliographical reference
Old Brisbane Botanic Gardens: Conservation Plan Review 2005, Report of Stage 1 Heritage Significance and Conservation Policies
Report for City Design, for Environment and Parks, within the Brisbane City Council.\ud
\ud
Context of this Project\ud
\ud
A Conservation Study for the Old Brisbane Botanic Gardens,\ud
formerly called the Brisbane City Botanic Gardens, was finalised in\ud
1995 and prepared by Jeannie Sim for the Landscape Section of\ud
Brisbane City Council, the same author of the present report. This\ud
unpublished report was the first conservation plan prepared for the\ud
place and it was recommended that it be reviewed in five years\ud
time. That time has arrived finally with the preparation of the 2005\ud
Review. The present project was commissioned by City Design on\ud
behalf of Environment and Parks Section of Brisbane City Council.\ud
\ud
The author has purposely chosen to call the study site the 'Old\ud
Brisbane Botanic Gardens' (OBBG) to differentiate it from the\ud
Brisbane Botanic Gardens, Mt. Coot-tha (BBG-MC), and to\ud
maintain the claim for this original garden to remain as a botanic\ud
garden for Brisbane. This name immediately brings to mind an\ud
association with history, as in the precedent set by the naming of\ud
the nearby 'Old Government House' at Gardens Point
Post-disaster school relocation : a case study of Chinese students’ adjustment after the Wenchuan earthquake
Author name used in this publication: Ng, Guat Tin.Author name used in this publication: Sim, Timothy.Accepted ManuscriptPublishedGreen (AAM
dim-sim
The dim-sim dataset is a collection of user-annotated music similarity triplet ratings used to evaluate music similarity search and related algorithms. Our similarity ratings are linked to the Million Song Dataset (MSD) and were collected for the following paper:
Disentangled Multidimensional Metric Learning for Music Similarity
Jongpil Lee, Nicholas J. Bryan, Justin Salamon, Zeyu Jin, and Juhan Nam.
Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (ICASSP). IEEE, 2020.
@inproceedings{Lee2019MusicSimilarity,
title={Disentangled Multidimensional Metric Learning For Music Similarity},
author={Lee, Jongpil and Bryan, Nicholas J. and Salamon, Justin and Jin, Zeyu, and Nam, Juhan},
booktitle={Proceedings of the International Conference on Acoustics, Speech and Signal Processing (ICASSP)},
year={2020},
organization={IEEE}
}
We kindly request that articles and other works in which this dataset is used cite the paper as listed above.
Please see our paper or visit https://jongpillee.github.io/multi-dim-music-sim for more information
Measurements of turbulence at stratocumulus top
Using 1m resolution airborne data from research flights we divide stratocumulus top region into sublayers and characterize properties of turbulence in each sublayer. Results indicate, that there are no clear differences of turbulence properties between thermodynamically different "calassical" and "non-classical" stratocumulus regimes, but there are clear signs of turbulence ainsotropy in stably stratified sublayers in the cloud top region
Mobile Supplicant for SIM Authentication
This Master’s thesis proposes a solution for utilizing the GSM SIM to authenticate users to distributed services accessed through the mobile terminal. By combining the GSM SIM authentication mechanisms with the EAP-SIM framework we achieve mutual authentication between the parties. By combining the fact that the GSM SIM is a tamper resistant Smart Card, and that users have to present a valid PIN to activate the system, we have also achieved strong two-factor authentication that fulfils the highest security level defined by NIST. The proposed system is secure, easy to use and inexpensive, because most of the components needed already exist in the GSM network today. Existing strong user authentication systems for mobile handsets require several devices to be able to offer secure services. The proposed system only requires one device, namely the mobile handset which the user is carrying anyway. The only user interaction required is typing the PIN. The authors’ major contribution to the proposed system is the Supplicant, residing on the mobile handset and communicating with the SIM through the SATSA-APDU interface. By running the Supplicant as a local proxy on the mobile handset, it is able to communicate with all kinds of client applications supporting HTTP, e.g. mobile browsers, J2ME MIDlets and native applications. A prototype implementing several of the components in the proposed system has been developed. Unfortunately, due to several reasons, the prototype cannot be deployed on a real mobile handset today’s date. We are missing the necessarily certificate required to get access to the SIM and neither of today’s mobile handsets support all the functionality needed. However, the prototype has been implemented successfully on a PC running the Wireless Toolkit from Sun, which simulates the SIM environment. Based on results from this thesis, the author has written the paper "A Unified Authentication Solution for Mobile Services". The paper was accepted and published on the ERCIM workshop on eMobility in Coimbra, Portugal, on May 2007
Mobile Supplicant for SIM Authentication
This Master’s thesis proposes a solution for utilizing the GSM SIM to authenticate users to distributed services accessed through the mobile terminal. By combining the GSM SIM authentication mechanisms with the EAP-SIM framework we achieve mutual authentication between the parties. By combining the fact that the GSM SIM is a tamper resistant Smart Card, and that users have to present a valid PIN to activate the system, we have also achieved strong two-factor authentication that fulfils the highest security level defined by NIST. The proposed system is secure, easy to use and inexpensive, because most of the components needed already exist in the GSM network today. Existing strong user authentication systems for mobile handsets require several devices to be able to offer secure services. The proposed system only requires one device, namely the mobile handset which the user is carrying anyway. The only user interaction required is typing the PIN. The authors’ major contribution to the proposed system is the Supplicant, residing on the mobile handset and communicating with the SIM through the SATSA-APDU interface. By running the Supplicant as a local proxy on the mobile handset, it is able to communicate with all kinds of client applications supporting HTTP, e.g. mobile browsers, J2ME MIDlets and native applications. A prototype implementing several of the components in the proposed system has been developed. Unfortunately, due to several reasons, the prototype cannot be deployed on a real mobile handset today’s date. We are missing the necessarily certificate required to get access to the SIM and neither of today’s mobile handsets support all the functionality needed. However, the prototype has been implemented successfully on a PC running the Wireless Toolkit from Sun, which simulates the SIM environment. Based on results from this thesis, the author has written the paper "A Unified Authentication Solution for Mobile Services". The paper was accepted and published on the ERCIM workshop on eMobility in Coimbra, Portugal, on May 2007
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