144 research outputs found

    A Novel Fusion Framework Based on Adaptive PCNN in NSCT Domain for Whole-Body PET and CT Images

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    The PET and CT fusion images, combining the anatomical and functional information, have important clinical meaning. This paper proposes a novel fusion framework based on adaptive pulse-coupled neural networks (PCNNs) in nonsubsampled contourlet transform (NSCT) domain for fusing whole-body PET and CT images. Firstly, the gradient average of each pixel is chosen as the linking strength of PCNN model to implement self-adaptability. Secondly, to improve the fusion performance, the novel sum-modified Laplacian (NSML) and energy of edge (EOE) are extracted as the external inputs of the PCNN models for low- and high-pass subbands, respectively. Lastly, the rule of max region energy is adopted as the fusion rule and different energy templates are employed in the low- and high-pass subbands. The experimental results on whole-body PET and CT data (239 slices contained by each modality) show that the proposed framework outperforms the other six methods in terms of the seven commonly used fusion performance metrics

    A Cooperative Perception System Robust to Localization Errors

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    Cooperative perception is challenging for safety-critical autonomous driving applications.The errors in the shared position and pose cause an inaccurate relative transform estimation and disrupt the robust mapping of the Ego vehicle. We propose a distributed object-level cooperative perception system called OptiMatch, in which the detected 3D bounding boxes and local state information are shared between the connected vehicles. To correct the noisy relative transform, the local measurements of both connected vehicles (bounding boxes) are utilized, and an optimal transport theory-based algorithm is developed to filter out those objects jointly detected by the vehicles along with their correspondence, constructing an associated co-visible set. A correction transform is estimated from the matched object pairs and further applied to the noisy relative transform, followed by global fusion and dynamic mapping. Experiment results show that robust performance is achieved for different levels of location and heading errors, and the proposed framework outperforms the state-of-the-art benchmark fusion schemes, including early, late, and intermediate fusion, on average precision by a large margin when location and/or heading errors occur.Comment: Accepted by IEEE IV 202

    Inconsistent phenomenon of thermoelectric load resistance for photovoltaic–thermoelectric module

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    Combing PV with Thermoelectric (TE) would be dominant because it can employ the solar fully spectrum to produce electricity. But the TE efficiency is significantly lower than PV efficiency and the coupling effect between them will limit the performance of PV and TE. The analyze and comparison on the different characteristics among the hybrid module, the PV alone and TE alone is significant to obtain the highest the electrical efficiency. In this paper, the attention was paid to the inconsistent phenomenon of thermoelectric load resistance for photo-voltaic–thermoelectric modules. The model of PV-TE was built and verified based on two types of PV cells. The load resistance of TE for the maximum power output was also analyzed under different working conditions for the TE alone, TE in the PV-TE and PV-TE. The results showed that the load resistance of TE for the maximum power output of the TE alone, TE in the PV-TE and PV-TE are all different. For example, the PV-TE module based on the c-Si cell attains its peak value at the load electrical resistance of TE of 0.75 Ω, while the internal electrical resistance of the TE is 0.47 Ω. The PV-TE module based on the GaAs cell shows a maximum efficiency of PV-TE with a load resistance of approximately 1.6 Ω, while the internal electrical resistance of the TE is 2.0 Ω. Referring to the load resistance of TE alone is not suitable for PV-TE maximum power output. In addition, the TE maximum power output does not correspond to the PV-TE maximum power output since the TE load resistances in these two conditions are also different. The study will provide the reference for attaining the correct load resistance for the actual maximum power output of PV-TE module

    Comprehensive Utilization of the Water Resources in small Watershed

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    AbstractThe water problem is a vital question which relates to the sustainable development of the national economy. And the water resource is also a kind of comprehensive natural resources which has a variety of use values and can supply with the water needs for many sections, which involves economy, resource, science and technology, ecosystem and environment. Sustainable utilization is a better form for the water resources. This paper gives a brief introduction about the technology of comprehensive utilization of the water resources in small watershed

    Improving Privacy of Anonymous Proof-of-Stake Protocols

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    The proof of stake (PoS) mechanism, which allows stakeholders to issue a block with a probability proportional to their wealth instead of computational power, is believed to be an energy-efficient alternative to the proof of work (PoW). The privacy concern of PoS, however, is more subtle than that of PoW. Recent research has shown that current anonymous PoS (APoS) protocols do not suffice to protect the stakeholder\u27s identity and stake, and the loss of privacy is theoretically inherent for any (deterministic) PoS protocol that provides liveness guarantees. In this paper, we consider the concrete stake privacy of PoS when considering the limitations of attacks in practice. To quantify the concrete stake privacy of PoS, we introduce the notion of (T,δ,ϵ)(T, \delta, \epsilon)-privacy. Our analysis of (T,δ,ϵ)(T, \delta, \epsilon)-privacy on Cardano shows to what extent the stake privacy can be broken in practice, which also implies possible parameters setting of rational (T,δ,ϵ)(T, \delta, \epsilon)-privacy for PoS in the real world. The data analysis of Cardano demonstrates that the (T,δ,ϵ)(T, \delta, \epsilon)-privacy of current APoS is not satisfactory, mainly due to the deterministic leader election predicate in current PoS constructions. Inspired by the differential privacy technique, we propose an efficient non-deterministic leader election predicate, which can be used as a plugin to APoS protocols to protect stakes against frequency analysis. Based on our leader election predicate, we construct anonymous PoS with noise (APoS-N), which can offer better (T,δ,ϵ)(T, \delta, \epsilon)-privacy than state-of-the-art works. Furthermore, we propose a method of proving the basic security properties of PoS in the noise setting, which can minimize the impact of the noise on the security threshold. This method can also be applied to the setting of PoS with variable stakes, which is of independent interest

    Turnover intention and coping strategies among older nursing assistants in China: a qualitative study

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    IntroductionWith the increasing aging population, older nursing assistants have made significant contributions to institutional eldercare. However, there is a high turnover rate among these workers, and it is crucial to address this issue and find ways to stabilize the workforce. This study aimed to explore the factors influencing turnover intention and coping strategies among older nursing assistants, in order to provide targeted assistance and guidance to reduce their intention to resign and ultimately lower the turnover rate.MethodsQualitative research methods were employed to conduct semi-structured interviews with older nursing assistants in Changsha. The data obtained from these interviews were then analyzed using a phenomenological analysis approach and NVIVO (QSR International, Doncaster, Australia) software version 11.0.ResultsIt is found that several factors influence turnover intention among older nursing assistants. Which include work pay, work environment, professional identity, external motivation, and work pressure. Additionally, the coping strategies employed by these individuals in relation to their intention to resign include self-regulation, seeking support, self-improvement, and exploring motivation.DiscussionIt is also evident from our study that reducing the turnover intention of older nursing assistants requires a collaborative effort from older adult care institutions, functional departments, and eldercare nursing assistants themselves. By addressing the factors influencing turnover intention and providing support and resources for coping strategies, we can work towards stabilizing the workforce and improving institutional eldercare

    The effect of vitamin D deficiency during pregnancy on adverse birth outcomes in neonates: a systematic review and meta-analysis

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    ObjectiveTo systematically evaluate the effect of vitamin D deficiency during pregnancy on neonatal adverse outcomes, such as preterm infants, low birth weight infants (LBWI), and small for gestational age (SGA) infants.MethodsA comprehensive literature search was conducted across multiple databases including PubMed, Embase, Cochrane Library, SinoMed, Wanfang Data Knowledge Service Platform, China National Knowledge Internet (CNKI), and VIP Chinese Science and Technology Journal Database (VIP). Following predefined inclusion and exclusion criteria, two researchers independently screened, extracted data, and assessed the quality of the included studies. Meta-analysis was performed using RevMan 5.4 and Stata 14 software to synthesize the findings.ResultsThis study incorporated 13 cohort studies from 8 different countries and regions, encompassing a total of 55,162 pregnant women, among whom 28,155 were identified as having vitamin D deficiency. The Newcastle-Ottawa Scale (NOS) score ranged from 7–9 points. Meta-analysis results indicated a higher incidence of LBWI (OR = 5.52, 95% CI = 1.31–23.22. P = 0.02) in the group of pregnant women with vitamin D deficiency compared to those with adequate levels. However, there was no statistically significant difference in the likelihood of premature birth (OR = 1.25, 95% CI = 0.78–1.99. P = 0.36) or SGA (OR = 1.47, 95% CI = 0.81–2.68. P = 0.21) among newborns born to mothers with vitamin D deficiency vs. those with sufficient levels of vitamin D. Subgroup analysis based on the timing of maternal blood collection revealed that there was no statistically significant association between vitamin D levels during pregnancy and the incidence of preterm birth across all stages of pregnancy. Furthermore, vitamin D deficiency throughout the entire pregnancy was associated with an increased incidence of neonatal LBWI, whereas vitamin D levels during the first, second, and third trimesters did not demonstrate statistically differences on LBWI. Neonates born to mothers with vitamin D deficiency throughout pregnancy were found to have a higher likelihood of developing SGA. However, there was no statistically significant association between vitamin D levels and the development of SGA during the first and second trimesters.ConclusionsAdequate levels of vitamin D during pregnancy may decrease the incidence of LBWI, although further research is needed to determine its impact on the occurrence of preterm birth and SGA.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024535950, Identifier: (CRD42024535950)

    New Open Cluster Candidates Discovered in the XSTPS-GAC Survey

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    The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center (XSTPS-GAC) is a photometric sky survey that covers nearly 6 000 deg^2 towards Galactic anti-center in g r i bands. Half of its survey field locates on the Galactic Anti-center disk, which makes XSTPS-GAC highly suitable for searching new open clusters in the GAC region. In this paper, we report new open cluster candidates discovered in this survey, as well as properties of these open cluster candidates, such as age, distance and reddening, derived by isochrone fitting in the color-magnitude diagram (CMD). These open cluster candidates are stellar density peaks detected in the star density maps by applying the method from Koposov et al. (2008). Each candidate is inspected on its true color image composed from XSTPS-GAC three band images. Then its CMD is checked, in order to identify whether the central region stars have a clear isochrone-like trend differing from the background stars. The parameters derived from isochrone fitting for these candidates are mainly based on three band photometry of XSTPS-GAC. Meanwhile, when these new candidates are able to be seen clearly on 2MASS, their parameters are also derived based on 2MASS (J-H, J) CMD. Finally, there are 320 known open clusters rediscovered and 24 new open cluster candidates discovered in this work. Further more, the parameters of these new candidates, as well as another 11 known recovered open clusters, are properly determined for the first time.Comment: 19 pages, 11 figures, 3 tables, accepted for publication in Research in Astronomy and Astrophysic
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