207 research outputs found
High efficient computational integral imaging reconstruction based on parallel-group projection (PGP) method
International audienceIntegral imaging is an auto-stereoscopic 3D technique presenting remarkable advantages over classical stereo. In this paper we propose a new computational integral imaging reconstruction (CIIR) technique based on parallel-Group Projection (PGP) method to improve the performance of CIIR. Different from previous CIIR techniques which project each point of integral image (II) to the reconstructed plane pixel by pixel, the proposed method reconstruct the 3D image by mapping a series of sub image (SI) onto the reconstructed plane successively, where each SI records pixels from parallel light rays with identical viewing angle. According to experimental results, this approach is able to simplify the calculation of reconstruction process and improve the quality of reconstructed 3D image
An analytical and numerical study of magnetic spring suspension and energy recovery mechanism
As the automotive paradigm shifts towards electric, limited range remains a key challenge. Increasing the battery size adds weight, which yields diminishing returns in range per kilowatt-hour. Therefore, energy recovery systems, such as regenerative braking and photovoltaic cells, are desirable to recharge the onboard batteries in between hub charge cycles. While some reports of regenerative suspension do exist, they all harvest energy in a parasitic manner, and the predicted power output is extremely low, since the majority of the energy is still dissipated to the environment by the suspension. This paper proposes a fundamental suspension redesign using a magnetically-levitated spring mechanism and aims to increase the recoverable energy significantly by directly coupling an electromagnetic transducer as the main damper. Furthermore, the highly nonlinear magnetic restoring force can also potentially enhance rider comfort. Analytical and numerical models have been constructed. Road roughness data from an Australian road were used to numerically simulate a representative environment response. Simulation suggests that 10âs of kW to >100 kW can theoretically be generated by a medium-sized car travelling on a typical paved road (about 2â3 orders of magnitude higher than literature reports on parasitic regenerative suspension schemes), while still maintaining well below the discomfort threshold for passengers (<0.315 m/s 2 on average)
Competitive Ensembling Teacher-Student Framework for Semi-Supervised Left Atrium MRI Segmentation
Semi-supervised learning has greatly advanced medical image segmentation
since it effectively alleviates the need of acquiring abundant annotations from
experts and utilizes unlabeled data which is much easier to acquire. Among
existing perturbed consistency learning methods, mean-teacher model serves as a
standard baseline for semi-supervised medical image segmentation. In this
paper, we present a simple yet efficient competitive ensembling teacher student
framework for semi-supervised for left atrium segmentation from 3D MR images,
in which two student models with different task-level disturbances are
introduced to learn mutually, while a competitive ensembling strategy is
performed to ensemble more reliable information to teacher model. Different
from the one-way transfer between teacher and student models, our framework
facilitates the collaborative learning procedure of different student models
with the guidance of teacher model and motivates different training networks
for a competitive learning and ensembling procedure to achieve better
performance. We evaluate our proposed method on the public Left Atrium (LA)
dataset and it obtains impressive performance gains by exploiting the unlabeled
data effectively and outperforms several existing semi-supervised methods.Comment: Accepeted for BIBM 202
D-STEM: a Design led approach to STEM innovation
Advances in the Science, Technology, Engineering and Maths (STEM) disciplines offer opportunities for designers to propose and make products with advanced, enhanced and engineered properties and functionalities. In turn, these advanced characteristics are becoming increasingly necessary as resources become ever more strained through 21st century demands, such as ageing populations, connected communities, depleting raw materials, waste management and energy supply. We need to make things that are smarter, make our lives easier, better and simpler. The products of tomorrow need to do more with less. The issue is how to maximize the potential for exploiting opportunities offered by STEM developments and how best to enable designers to strengthen their position within the innovation ecosystem. As a society, we need designers able to navigate emerging developments from the STEM community to a level that enables understanding and knowledge of the new material properties, the skill set to facilitate absorption into the design âtoolboxâ and the agility to identify, manage and contextualise innovation opportunities emerging from STEM developments. This paper proposes the blueprint for a new design led approach to STEM innovation that begins to redefine studio culture for the 21st Century
Characteristics of Pollen from Transgenic Lines of Apple Carrying the Exogenous CpTI Gene
AbstractIt is fundamental for gene transformation and ecosystem hazard evaluation to study the pollen characteristics of transgenic plants. In this research, the characteristics of pollen from 7- or 8-year-old transgenic apple plants carrying an exogenous CpTI gene were analyzed. The results showed that there was no significant difference in terms of size, morphology, or exine ornamentation between the pollen of the transgenic plants and the non-transgenic control. However, the transgenic plants had more abnormal pollen grains. Of the 13 transgenic lines tested, 12 had a significantly lower amount of pollen and six exhibited a significantly lower germination rate when cultured in vitro. The pollen viability of three transgenic lines was determined, with two showing significantly lower viability than the control. The transgenic Gala apple pollen grains germinated normally via controlled pollination on Fuji apple stigmas. However, the pollen tubes extended relatively slowly during the middle and late development stages, and another 8h were needed to reach the ovules compared with the control. The gibberellic acid concentration in transgenic Gala apple flowers was lower than in the non-transgenic control during all development stages tested. The abscisic acid concentration in the transgenic flowers was lower during the pink stage, and higher during the ball and fully open stages. Microscopic observation of the anther structure showed no difference. The tapetum of the pollen sac wall in transgenic plants decomposed late and affected pollen grain development, which could be one of the reasons for the lower number of pollen grains and poor viability in the transgenic plants
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