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A Experimental Setup

Neural Information Processing Systems

A.2 Training Settings of T eacher We provide training settings of the teacher w.r.t. In practice, we do not optimize the student and the generator via the plain losses in Eq. 4 and Eq. 6, Number of steps for pretraining G, ฮด: the bound in Eqs. A.4 Generator Architectures In Table 8, we show different architectures of the generator w.r.t. ResNetBlockY are provided in Table 9. ConvBlockX(c This is because the "uncond" generator has learned to jump "sum" generator enables stable training of our model and gives the best accuracy and crossentropy The "cat" generator only yields good results at "uncond" generator does not encounter any problem with MAD to learn faster than the "cat" generator. An important question is "What is a reasonable upper bound


Efficient $k$-NN Search in IoT Data: Overlap Optimization in Tree-Based Indexing Structures

arXiv.org Artificial Intelligence

The proliferation of interconnected devices in the Internet of Things (IoT) has led to an exponential increase in data, commonly known as Big IoT Data. Efficient retrieval of this heterogeneous data demands a robust indexing mechanism for effective organization. However, a significant challenge remains: the overlap in data space partitions during index construction. This overlap increases node access during search and retrieval, resulting in higher resource consumption, performance bottlenecks, and impedes system scalability. To address this issue, we propose three innovative heuristics designed to quantify and strategically reduce data space partition overlap. The volume-based method (VBM) offers a detailed assessment by calculating the intersection volume between partitions, providing deeper insights into spatial relationships. The distance-based method (DBM) enhances efficiency by using the distance between partition centers and radii to evaluate overlap, offering a streamlined yet accurate approach. Finally, the object-based method (OBM) provides a practical solution by counting objects across multiple partitions, delivering an intuitive understanding of data space dynamics. Experimental results demonstrate the effectiveness of these methods in reducing search time, underscoring their potential to improve data space partitioning and enhance overall system performance.


Explicit Formulae to Interchangeably use Hyperplanes and Hyperballs using Inversive Geometry

arXiv.org Machine Learning

Many algorithms require discriminative boundaries, such as separating hyperplanes or hyperballs, or are specifically designed to work on spherical data. By applying inversive geometry, we show that the two discriminative boundaries can be used interchangeably, and that general Euclidean data can be transformed into spherical data, whenever a change in point distances is acceptable. We provide explicit formulae to embed general Euclidean data into spherical data and to unembed it back. We further show a duality between hyperspherical caps, i.e., the volume created by a separating hyperplane on spherical data, and hyperballs and provide explicit formulae to map between the two. We further provide equations to translate inner products and Euclidean distances between the two spaces, to avoid explicit embedding and unembedding. We also provide a method to enforce projections of the general Euclidean space onto hemi-hyperspheres and propose an intrinsic dimensionality based method to obtain "all-purpose" parameters. To show the usefulness of the cap-ball-duality, we discuss example applications in machine learning and vector similarity search.


Formal Ways for Measuring Relations between Concepts in Conceptual Spaces

arXiv.org Artificial Intelligence

The highly influential framework of conceptual spaces provides a geometric way of representing knowledge. Instances are represented by points in a high-dimensional space and concepts are represented by regions in this space. In this article, we extend our recent mathematical formalization of this framework by providing quantitative mathematical definitions for measuring relations between concepts: We develop formal ways for computing concept size, subsethood, implication, similarity, and betweenness. This considerably increases the representational capabilities of our formalization and makes it the most thorough and comprehensive formalization of conceptual spaces developed so far.


Random-Radius Ball Method for Estimating Closeness Centrality

AAAI Conferences

In the analysis of real-world complex networks, identifying important vertices is one of the most fundamental operations. A variety of centrality measures have been proposed and extensively studied in various research areas. Many of distance-based centrality measures embrace some issues in treating disconnected networks, which are resolved by the recently emerged harmonic centrality. This paper focuses on a family of centrality measures including the harmonic centrality and its variants, and addresses their computational difficulty on very large graphs by presenting a new estimation algorithm named the random-radius ball (RRB) method. The RRB method is easy to implement, and a theoretical analysis, which includes the time complexity and error bounds, is also provided. The effectiveness of the RRB method over existing algorithms is demonstrated through experiments on real-world networks.


Safe and Efficient Screening For Sparse Support Vector Machine

arXiv.org Machine Learning

Assume that X E Him" is a data set containing 71 samples, X: (x1, . . . Let w*()\) be the optimal solution of Eq. (1) All the features With nonzero values in "w" (A) are called active The Lagrangian multiplier [1] of the problem defined in Eq. (1) is: The Eq. (2) can be reformulated as: Since the problem defined in Eq. (1) is convex and the optimal value of the In the preceding equation i'j: ij, and Y is a diagonal matrix and YM: When the input is given, it can be obtained in a closed form. The Ll--regularized L2--Loss SVM in Eq. (1) can be rewritten in an uncon-- Eq. (22) shows that the necessary condition for a feature f to be active in the To bound value of 0Tf' 7 we need to first construct a closed convex set K that We first study how to construct the convex set K. In the following, we construct a closed convex set K based on Eq. (19) and The proof of this proposition can be found in [2]. Let 01 and 02 be the optimal solutions of the problem defined in Eq. (19) for Assume that /\1 A2, and 01 is known. In the preceding equations, 01, A1, and /\2 are known. Figure 1 shows an example of the K in a two dimensional space. And K is indicated by the shaded area. It is indicated by the shaded area. Besides the n dimensional hyperball defined in Eq. (32), it is possible to By applying Proposition 6.1 to the objective function defined in Eq. (33) for 01, Let t::--: Z 0. By substituting 0: 02 and 0: 01 into Eq. Eq. (35)7 respectively, and then combining the two obtained equations7 the As the value of t change from 0 to 007 Eq. (36) generates a series of hyperball. Eq. (36) reaches it minimum when, The theorem can be proved by minimizing the 7" defined in Eq. (36).