958 research outputs found
Development and Integration of Geometric and Optimization Algorithms for Packing and Layout Design
The research work presented in this dissertation focuses on the development and application of optimization and geometric algorithms to packing and layout optimization problems. As part of this research work, a compact packing algorithm, a physically-based shape morphing algorithm, and a general purpose constrained multi-objective optimization algorithm are proposed. The compact packing algorithm is designed to pack three-dimensional free-form objects with full rotational freedom inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed compact packing algorithm can handle objects with holes or cavities and its performance does not degrade significantly with the increase in the complexity of the enclosure or the objects. It outputs the location and orientation of all the objects, the packing sequence, and the packed configuration at the end of the packing operation. An improved layout algorithm that works with arbitrary enclosure geometry is also proposed. Different layout algorithms for the SAE and ISO luggage are proposed that exploit the unique characteristics of the problem under consideration. Several heuristics to improve the performance of the packing algorithm are also proposed. The proposed compact packing algorithm is benchmarked on a wide variety of synthetic and hypothetical problems and is shown to outperform other similar approaches. The physically-based shape morphing algorithm proposed in this dissertation is specifically designed for packing and layout applications, and thus it augments the compact packing algorithm. The proposed shape morphing algorithm is based on a modified mass-spring system which is used to model the morphable object. The shape morphing algorithm mimics a quasi-physical process similar to the inflation/deflation of a balloon filled with air. The morphing algorithm starts with an initial manifold geometry and morphs it to obtain a desired volume such that the obtained geometry does not interfere with the objects surrounding it. Several modifications to the original mass-spring system and to the underlying physics that governs it are proposed to significantly speed-up the shape morphing process. Since the geometry of a morphable object continuously changes during the morphing process, most collision detection algorithms that assume the colliding objects to be rigid cannot be used efficiently. And therefore, a general-purpose surface collision detection algorithm is also proposed that works with deformable objects and does not require any preprocessing. Many industrial design problems such as packing and layout optimization are computationally expensive, and a faster optimization algorithm can reduce the number of iterations (function evaluations) required to find the satisfycing solutions. A new multi-objective optimization algorithm namely Archive-based Micro Genetic Algorithm (AMGA2) is presented in this dissertation. Improved formulation for various operators used by the AMGA2 such as diversity preservation techniques, genetic variation operators, and the selection mechanism are also proposed. The AMGA2 also borrows several concepts from mathematical sciences to improve its performance and benefits from the existing literature in evolutionary optimization. A comprehensive benchmarking and comparison of AMGA2 with other state-of-the-art optimization algorithms on a wide variety of mathematical problems gleaned from literature demonstrates the superior performance of AMGA2. Thus, the research work presented in this dissertation makes contributions to the development and application of optimization and geometric algorithms
Generating 2D and 3D Master Faces for Dictionary Attacks with a Network-Assisted Latent Space Evolution
A master face is a face image that passes face-based identity authentication
for a high percentage of the population. These faces can be used to
impersonate, with a high probability of success, any user, without having
access to any user information. We optimize these faces for 2D and 3D face
verification models, by using an evolutionary algorithm in the latent embedding
space of the StyleGAN face generator. For 2D face verification, multiple
evolutionary strategies are compared, and we propose a novel approach that
employs a neural network to direct the search toward promising samples, without
adding fitness evaluations. The results we present demonstrate that it is
possible to obtain a considerable coverage of the identities in the LFW or RFW
datasets with less than 10 master faces, for six leading deep face recognition
systems. In 3D, we generate faces using the 2D StyleGAN2 generator and predict
a 3D structure using a deep 3D face reconstruction network. When employing two
different 3D face recognition systems, we are able to obtain a coverage of
40%-50%. Additionally, we present the generation of paired 2D RGB and 3D master
faces, which simultaneously match 2D and 3D models with high impersonation
rates.Comment: accepted for publication in IEEE Transactions on Biometrics,
Behavior, and Identity Science (TBIOM). This paper extends arXiv:2108.01077
that was accepted to IEEE FG 202
A survey of face detection, extraction and recognition
The goal of this paper is to present a critical survey of existing literatures on human face recognition over the last 4-5 years. Interest and research activities in face recognition have increased significantly over the past few years, especially after the American airliner tragedy on September 11 in 2001. While this growth largely is driven by growing application demands, such as static matching of controlled photographs as in mug shots matching, credit card verification to surveillance video images, identification for law enforcement and authentication for banking and security system access, advances in signal analysis techniques, such as wavelets and neural networks, are also important catalysts. As the number of proposed techniques increases, survey and evaluation becomes important
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