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Functional data, including one-dimensional curves and higher-dimensional surfaces, have become increasingly prominent across scientific disciplines. They offer a continuous perspective that captures subtle dynamics and richer structures compared to discrete representations, thereby preserving essential information and facilitating the more natural modeling of real-world phenomena, especially in sparse or irregularly sampled settings. A key challenge lies in identifying low-dimensional representations and estimating covariance structures that capture population statistics effectively. We propose a novel Bayesian framework with a nonparametric kernel expansion and a sparse prior, enabling the direct modeling of measured data and avoiding the artificial biases from regridding. Our method, Bayesian scalable functional data analysis (BSFDA), automatically selects both subspace dimensionalities and basis functions, reducing the computational overhead through an efficient variational optimization strategy. We further propose a faster approximate variant that maintains comparable accuracy but accelerates computations significantly on large-scale datasets. Extensive simulation studies demonstrate that our framework outperforms conventional techniques in covariance estimation and dimensionality selection, showing resilience to high dimensionality and irregular sampling. The proposed methodology proves effective for multidimensional functional data and showcases practical applicability in biomedical and meteorological datasets. Overall, BSFDA offers an adaptive, continuous, and scalable solution for modern functional data analysis across diverse scientific domains.

Machine learning models often rely on simple spurious features – patterns in training data that correlate with targets but are not causally related to them, like image backgrounds in foreground classification. This reliance typically leads to imbalanced test performance across minority and majority groups. In this work, we take a closer look at the fundamental cause of such imbalanced performance through the lens of memorization, which refers to the ability to predict accurately on atypical examples (minority groups) in the training set but failing in achieving the same accuracy in the testing set. This paper systematically shows the ubiquitous existence of spurious features in a small set of neurons within the network, providing the first-ever evidence that memorization may contribute to imbalanced group performance. Through three experimental sources of converging empirical evidence, we find the property of a small subset of neurons or channels in memorizing minority group information. Inspired by these findings, we hypothesize that spurious memorization, concentrated within a small subset of neurons, plays a key role in driving imbalanced group performance. To further substantiate this hypothesis, we show that eliminating these unnecessary spurious memorization patterns via a novel framework during training can significantly affect the model performance on minority groups. Our experimental results across various architectures and benchmarks offer new insights on how neural networks encode core and spurious knowledge, laying the groundwork for future research in demystifying robustness to spurious correlation. Spurious feature reliance is a challenge in achieving balanced performance in machine learning models. Here, the authors demonstrate that a small subset of neurons are responsible for memorizing spurious correlations and show that this concentrated memorization contributes to imbalanced performance.

Advances in imaging and early cancer detection have increased interest in magnetic resonance (MR) guided focused ultrasound (MRgFUS) technologies for cancer treatment. MRgFUS ablation treatments could reduce surgical risks, preserve organ tissue and function, and improve patient quality of life. However, surgical resection and histological analysis remain the gold standard to assess cancer treatment response. For non-invasive ablation therapies such as MRgFUS, the treatment response must be determined through MR imaging biomarkers. However, current MR biomarkers are inconclusive and have not been rigorously evaluated against histology via accurate registration. Existing registration methods rely on anatomical features to directly register in vivo MR and histology. For MRgFUS applications in anatomies such as liver, kidney, or breast, anatomical features that are not caused by the treatment are often insufficient to drive direct registration. We present a novel MR to histology registration workflow that utilizes intermediate imaging and does not rely on anatomical MR features being visible in histology. The presented workflow yields an overall registration accuracy of 1.00 ± 0.13 mm. The developed registration pipeline is used to evaluate a common MRgFUS treatment assessment biomarker against histology. Evaluating MR biomarkers against histology using this registration pipeline will facilitate validating novel MRgFUS biomarkers to improve treatment assessment without surgical intervention. While the presented registration technique has been evaluated in a MRgFUS ablation treatment model, this technique could be potentially applied in any tissue to evaluate a variety of therapeutic options.

We present schemes for simulating Brownian bridges on complete and connected Lie groups and homogeneous spaces. We use this to construct an estimation scheme for recovering an unknown left- or right-invariant Riemannian metric on the Lie group from samples. We subsequently show how pushing forward the distributions generated by Brownian motions on the group results in distributions on homogeneous spaces that exhibit a non-trivial covariance structure. The pushforward measure gives rise to new non-parametric families of distributions on commonly occurring spaces such as spheres and symmetric positive tensors. We extend the estimation scheme to fit these distributions to homogeneous space-valued data. We demonstrate both the simulation schemes and estimation procedures on Lie groups and homogenous spaces, including SPD(3)=GL+(3)/SO(3) and S2=SO(3)/SO(2).

We present a mixed reality-based assistive system for shading paper sketches. Given a paper sketch made by an artist, our interface helps inexperienced users to shade it appropriately. Initially, using a simple Delaunay-triangulation based inflation algorithm, an approximate depth map is computed. The system then highlights areas (to assist shading) based on a rendering of the 2.5-dimensional inflated model of the input contour. With the help of a mixed reality system, we project the highlighted areas back to aid users. The hints given by the system are used for shading and are smudged appropriately to apply an artistic shading to the sketch. The user is given flexibility at various levels to simulate conditions such as height and light position. Experiments show that the proposed system aids novice users in creating sketches with impressive shading.

Purpose The purpose of this paper is to examine the relationships between supplier development practices (SDPs) and supplier-buyer relationship practices from the supplier’s perspective (SBRSP), and seek to understand how specific SDPs may impact a buyer’s operational performance as well as supplier-buyer relationship practices. Design/methodology/approach The authors conducted a survey of 512 respondents from the different manufacturing firms in India and applied structural equation modelling to test a structural model that proposes the impacts of various efforts of SDPs on a buyer’s performance as well as SBRSP. Findings The study concludes that SDPs and SBRSP together improve the relationship between a buyer and supplier, and this improved relationship leads to competitive advantages (CAs) followed by profitability. Results indicate that supplier perspective of buyer-supplier relationship can be improved under the condition of SDPs and SBRSP together. SDPs are driven by productive measure and competitive pressure, whereas customer uncertainty is found to be statistically insignificant. Research limitations/implications The study was carried out in North Maharashtra Industrial Zone of India, where the auto sector and machine/components manufacturing firms have been established for a considerable period of time. Results of the study are limited to manufacturing organizations predominantly focussing on the automobile sector and machine/components manufacturing firms. Practical implications This study provides significant insights into the specific impact of various SDPs and SBRSP for both academics and practitioners. SDPs along with SBRSP practices lead to improvement in the relationship leading to CAs. SBRSP suggests that trust, long-term commitments and the supplier’s perspective are important practices for relationship improvement. Originality/value The current study attempts to identify what are the success factors for the supplier-buyer relationship from the supplier’s perspective and SDPs and how the supplier-buyer relationship can be improved under the condition of SDPs and SBRSP. Hence, the aim is to develop a more thorough understanding of the outcomes of a supplier-buyer relationship improvement from both buyer’s and supplier’s perspective, under the conditions of supplier development to achieve CAs leading to profitability. Furthermore, the study analyses the effect of the improved supplier-buyer relationship for achieving CAs leading to profitability.

The internet of things (IoT) is used in domestic, industrial as well as mission-critical systems including homes, transports, power plants, industrial manufacturing and health-care applications. Security of data generated by such systems and IoT systems itself is very critical in such applications. Early detection of any attack targeting IoT system is necessary to minimize the damage. This paper reviews security attack detection methods for IoT Infrastructure presented in the state-of-the-art. One of the major entry points for attacks in IoT system is topology exploitation. This paper proposes a distributed algorithm for early detection of such attacks with the help of predictive descriptor tables. This paper also presents feature selection from topology control packet fields. The performance of the proposed algorithm is evaluated using an extensive simulation carried out in OMNeT++. Performance parameter includes accuracy and time required for detection. Simulation results presented in this paper show that the proposed algorithm is effective in detecting attacks ahead in time.

The asymmetry of brain structures has been studied in schizophrenia to better understand its underlying neurobiology. Brain regions of interest have previously been characterized by volumes, cross-sectional and surface areas, and lengths. Using high-dimensional brain mapping, we have developed a statistical method for analyzing patterns of left–right asymmetry of the human hippocampus taken from high-resolution MR scans. We introduce asymmetry measures that capture differences in the patterns of high-dimensional vector fields between the left and right hippocampus surfaces. In 15 pairs of subjects previously studied (J. G. Csernansky et al., 1998, Proc. Natl. Acad. Sci. USA 95, 11406–11411). we define the difference in hippocampal asymmetry patterns between the groups. Volume analysis indicated a large normative asymmetry between left and right hippocampus (R > L), and shape analysis allowed us to visualize the normative asymmetry pattern of the hippocampal surfaces. We observed that the right hippocampus was wider along its lateral side in both schizophrenia and control subjects. Also, while patterns of hippocampal asymmetry were generally similar in the schizophrenia and control groups, a principal component analysis based on left–right asymmetry vector fields detected a statistically significant difference between the two groups, specifically related to the subiculum.

Development of supplier base is becoming mandatory for buyers, as it is not possible to manufacture all components in house, or to search new supplier every time. It is recommended that supplier base of buyer should be self-efficient and developed one to achieve competitive advantages. This development of supplier can be achieved by applying different supplier development practices and buyer supplier relationship practices as per the requirement. In this article, Exploratory Factor analysis (EFA) is applied for grouping the critical success factors with their items by using SPSS software. 6 factors viz., Drivers for Supplier Development Practices, Supplier Development Practices, Buyer supplier Relationship Practices, Buyer supplier Relationship Improvement, Competitive Advantages and Profitability were formed with their respective items. The multi-item scale shows strong evidence of reliability as well as convergent, discriminant validity in a sample. EFA and Reliability Analysis were applied on data for validation of instrument. Data from 87 respondents working in manufacturing sector were used for analysis.

We develop a framework for polynomial regression on Riemannian manifolds. Unlike recently developed spline models on Riemannian manifolds, Riemannian polynomials offer the ability to model parametric polynomials of all integer orders, odd and even. An intrinsic adjoint method is employed to compute variations of the matching functional, and polynomial regression is accomplished using a gradient-based optimization scheme. We apply our polynomial regression framework in the context of shape analysis in Kendall shape space as well as in diffeomorphic landmark space. Our algorithm is shown to be particularly convenient in Riemannian manifolds with additional symmetry, such as Lie groups and homogeneous spaces with right or left invariant metrics. As a particularly important example, we also apply polynomial regression to time-series imaging data using a right invariant Sobolev metric on the diffeomorphism group. The results show that Riemannian polynomials provide a practical model for parametric curve regression, while offering increased flexibility over geodesics.