231 research outputs found

    Medial Axis Approximation and Regularization

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    Medial axis is a classical shape descriptor. Among many good properties, medial axis is thin, centered in the shape, and topology preserving. Therefore, it is constantly sought after by researchers and practitioners in their respective domains. However, two barriers remain that hinder wide adoption of medial axis. First, exact computation of medial axis is very difficult. Hence, in practice medial axis is approximated discretely. Though abundant approximation methods exist, they are either limited in scalability, insufficient in theoretical soundness, or susceptible to numerical issues. Second, medial axis is easily disturbed by small noises on its defining shape. A majority of current works define a significance measure to prune noises on medial axis. Among them, local measures are widely available due to their efficiency, but can be either too aggressive or conservative. While global measures outperform local ones in differentiating noises from features, they are rarely well-defined or efficient to compute. In this dissertation, we attempt to address these issues with sound, robust and efficient solutions. In Chapter 2, we propose a novel medial axis approximation called voxel core. We show voxel core is topologically and geometrically convergent to the true medial axis. We then describe a straightforward implementation as a result of our simple definition. In a variety of experiments, our method is shown to be efficient and robust in delivering topological promises on a wide range of shapes. In Chapter 3, we present Erosion Thickness (ET) to regularize instability. ET is the first global measure in 3D that is well-defined and efficient to compute. To demonstrate its usefulness, we utilize ET to generate a family of shape revealing and topology preserving skeletons. Finally, we point out future directions, and potential applications of our works in real world problems

    LivePose: Online 3D Reconstruction from Monocular Video with Dynamic Camera Poses

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    Dense 3D reconstruction from RGB images traditionally assumes static camera pose estimates. This assumption has endured, even as recent works have increasingly focused on real-time methods for mobile devices. However, the assumption of a fixed pose for each image does not hold for online execution: poses from real-time SLAM are dynamic and may be updated following events such as bundle adjustment and loop closure. This has been addressed in the RGB-D setting, by de-integrating past views and re-integrating them with updated poses, but it remains largely untreated in the RGB-only setting. We formalize this problem to define the new task of dense online reconstruction from dynamically-posed images. To support further research, we introduce a dataset called LivePose containing the dynamic poses from a SLAM system running on ScanNet. We select three recent reconstruction systems and apply a framework based on de-integration to adapt each one to the dynamic-pose setting. In addition, we propose a novel, non-linear de-integration module that learns to remove stale scene content. We show that responding to pose updates is critical for high-quality reconstruction, and that our de-integration framework is an effective solution.Comment: ICCV 202

    Pengaruh Konsentrasi Ekstrak Daun Kepel (Stelechocarpus Burahol (Bl) Hook F. & Th.) Terhadap Aktivitas Antioksidan Dan Sifat Fisik Sediaan Krim

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    This research was aimed to determine the effect of concentrations of Kepel leaves\u27 (Stelechocarpus burahol (BL) Hook f. & Th.)extract to antioxidant activity and physical properties of cream. Kepel leaves\u27 extract were made by infundation method. The antioxidant activity was tested by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. Cream was made in three formulas with variation concentrations of Kepel leaves\u27 extract (2,5; 5,0; 7,5%b/b) using w/o basis. Physical stability parameters tested in this research were homogenity, dispersive power, adhesion, and viscosity. Data were then analyzed statistically by ANOVA One Way and Turkey Test at 95% level of significance. The results showed that concentration of Kepel leaves\u27 extract as an active ingredient cause different color, odor, and viscosity of the cream. The concentrationdifference of Kepel Leaves\u27 extract as an active ingredient was not affected the homogenity, adhesion, and the separation ratio of the cream. The difference concentration was not cause affected daya sebar cream unless the formula II (5.0% w/w) and formula III (7.5% w/w). Increasing concentration of Kepel leaves\u27 extract caused a different antioxidant activity unless the formula II (5.0% w/w) and formula III (7.5% w/w)

    FineRecon: Depth-aware Feed-forward Network for Detailed 3D Reconstruction

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    Recent works on 3D reconstruction from posed images have demonstrated that direct inference of scene-level 3D geometry without test-time optimization is feasible using deep neural networks, showing remarkable promise and high efficiency. However, the reconstructed geometry, typically represented as a 3D truncated signed distance function (TSDF), is often coarse without fine geometric details. To address this problem, we propose three effective solutions for improving the fidelity of inference-based 3D reconstructions. We first present a resolution-agnostic TSDF supervision strategy to provide the network with a more accurate learning signal during training, avoiding the pitfalls of TSDF interpolation seen in previous work. We then introduce a depth guidance strategy using multi-view depth estimates to enhance the scene representation and recover more accurate surfaces. Finally, we develop a novel architecture for the final layers of the network, conditioning the output TSDF prediction on high-resolution image features in addition to coarse voxel features, enabling sharper reconstruction of fine details. Our method, FineRecon, produces smooth and highly accurate reconstructions, showing significant improvements across multiple depth and 3D reconstruction metrics.Comment: ICCV 202

    The expression and clinical significance of GADD45A in breast cancer patients

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    Background Growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A) was previously found to be associated with risk of several kinds of human tumors. Here, we studied the expression and clinical significance of GADD45A in breast cancer. Methods We performed an immunohistochemical study of GADD45A protein from 419 breast cancer tissues and 116 adjacent non-neoplastic tissues. Results Significantly high GADD45A expression were observed in breast cancer tissues compared with adjacent non-neoplastic tissues (P < 0.001) and were independently correlative with estrogen receptor negative (P = 0.028) and high Ki-67 index (P < 0.001). Kaplan–Meier survival analysis revealed that patients with high GADD45A expression levels had a worse long-term prognosis in triple negative breast cancer (P = 0.041), but it was not an independent prognostic factor in multivariate analysis (P = 0.058). Conclusions GADD45A expression levels are significantly correlative with estrogen receptor status and Ki-67 index in human breast cancer. Patients with triple negative breast cancer might be stratified into high risk and low risk groups based on the GADD45A expression levels

    Unveiling Excitonic Dynamics in High-Efficiency Nonfullerene Organic Solar Cells to Direct Morphological Optimization for Suppressing Charge Recombination

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    Nonfullerene acceptors (NFAs)-based organic solar cells (OSCs) have recently drawn considerable research interests; however, their excitonic dynamics seems quite different than that of fullerene acceptors-based devices and remains to be largely explored. A random terpolymer of PBBF11 to pair with a paradigm NFA of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) such that both complementary optical absorption and very small offsets of both highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels are acquired is designed and synthesized. Despite the small energy offsets, efficient electron/hole transfer between PBBF11 and ITIC is both clearly observed from steady-state photoluminescence and transient absorption spectra and also supported by the measured low exciton binding energy in ITIC. Consequently, the PBBF11:ITIC-based OSCs afford an encouraging power conversion efficiency (PCE) of 10.02%. Although the good miscibility of PBBF11 and ITIC induces a homogenous blend film morphology, it causes severe charge recombination. The fullerene acceptor of PC 71 BM with varying loading ratios is therefore added to modulate film morphology to effectively reduce the charge recombination. As a result, the optimal OSCs based on PBBF11:ITIC:PC 71 BM yield a better PCE of 11.4% without any additive or annealing treatment. </p

    Several Critical Cell Types, Tissues, and Pathways Are Implicated in Genome-Wide Association Studies for Systemic Lupus Erythematosus

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    We aimed to elucidate the cell types, tissues, and pathways influenced by common variants in systemic lupus erythematosus (SLE). We applied a nonparameter enrichment statistical approach, termed SNPsea, in 181 single nucleotide polymorphisms (SNPs) that have been identified to be associated with the risk of SLE through genome-wide association studies (GWAS) in Eastern Asian and Caucasian populations, to manipulate the critical cell types, tissues, and pathways. In the two most significant cells’ findings (B lymphocytes and CD14+ monocytes), we subjected the GWAS association evidence in the Han Chinese population to an enrichment test of expression quantitative trait locus (QTL) sites and DNase I hypersensitivity, respectively. In both Eastern Asian and Caucasian populations, we observed that the expression level of SLE GWAS implicated genes was significantly elevated in xeroderma pigentosum B cells (P ≤ 1.00 × 10−6), CD14+ monocytes (P ≤ 2.74 × 10−4) and CD19+ B cells (P ≤ 2.00 × 10−6), and plasmacytoid dendritic cells (pDCs) (P ≤ 9.00 × 10−6). We revealed that the SLE GWAS-associated variants were more likely to reside in expression QTL in B lymphocytes (q1/q0 = 2.15, P = 1.23 × 10−44) and DNase I hypersensitivity sites (DHSs) in CD14+ monocytes (q1/q0 = 1.41, P = 0.08). We observed the common variants affected the risk of SLE mostly through by regulating multiple immune system processes and immune response signaling. This study sheds light on several immune cells and responses, as well as the regulatory effect of common variants in the pathogenesis of SLE

    Empower the Science of Organ Donation by Multidisciplinary Collaboration

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    Inter-discipline is formed by the interpenetration and integration of multiple disciplines, which has become a notable trend involving interdisciplinary activities and a combination of research and development. Learned from experience worldwide, the management mode for organ donation and procurement activities varies among countries, but the core of the disciplinary construction of organ donation remains the same. The theoretical basis and practice of organ donation is not purely a matter of coordination, but its ground of knowledge is built upon multidisciplinary integration and its implementation relies on a joint-effort approach and requires collaboration of multiple teams. From the sociological viewpoint, organ donation represents the gift of life for transplant patients, which founds the key element in enhancing the harmony of society. While, from a practical perspective, its professionalism has been widely recognized by the international medical community. As a complex medical and social act, organ donation is a medical-centered subject with sociological, humanistic, ethical, psychologic, and juristic attributes. This chapter will provide an overview of how multidisciplinary collaboration empowers the science of organ donation, followed by the summary of recent efforts taken in China in pursuit of this goal as an example
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