Michael T. Goodrich

Bio: Michael T. Goodrich is an academic researcher from University of California, Irvine. The author has contributed to research in topics: Planar graph & Parallel algorithm. The author has an hindex of 61, co-authored 430 publications receiving 14045 citations. Previous affiliations of Michael T. Goodrich include New York University & Technion – Israel Institute of Technology.

Secure biometric authentication for weak computational devices

Abstract: This paper presents computationally “lightweight” schemes for performing biometric authentication that carry out the comparison stage without revealing any information that can later be used to impersonate the user (or reveal personal biometric information). Unlike some previous computationally expensive schemes — which make use of slower cryptographic primitives — this paper presents methods that are particularly suited to financial institutions that authenticate users with biometric smartcards, sensors, and other computationally limited devices. In our schemes, the client and server need only perform cryptographic hash computations on the feature vectors, and do not perform any expensive digital signatures or public-key encryption operations. In fact, the schemes we present have properties that make them appealing even in a framework of powerful devices capable of public-key signatures and encryptions. Our schemes make it computationally infeasible for an attacker to impersonate a user even if the attacker completely compromises the information stored at the server, including all the server’s secret keys. Likewise, our schemes make it computationally infeasible for an attacker to impersonate a user even if the attacker completely compromises the information stored at the client device (but not the biometric itself, which is assumed to remain attached to the user and is not stored on the client device in any form).

Lombardi Drawings of Graphs

Abstract: We introduce the notion of Lombardi graph drawings, named after the American abstract artist Mark Lombardi. In these drawings, edges are represented as circular arcs rather than as line segments or polylines, and the vertices have perfect angular resolution: the edges are equally spaced around each vertex. We describe algorithms for finding Lombardi drawings of regular graphs, graphs of bounded degeneracy, and certain families of planar graphs.

Merging free trees in parallel for efficient Voronoi diagram construction

Abstract: This paper describes a new approach for constructing the Voronoi diagram of n points in the plane in parallel. Our approach is based on a divide-and-conquer procedure where we implement the “marry” step by merging forests of free trees (to build the “contour” between the subproblem solutions) in O(log log n) time. This merging procedure is based an a \(\sqrt n\)-divide-and-merge technique reminiscent of the list-merging approach of Valiant. Our method also involves an optimal parallel method for computing the proximity envelope of a point set with respect to a given line. This structure facilitates the use of our fast mering procedure, for it allows the divide-and-conquer procedure to continue without needing to explicitly remove edges of recursively constructed diagrams that are not part of the final diagram. We use this approach to derive two results regarding the deterministic parallel construction of a Voronoi diagram. Specifically, we show that one can solve the Voronoi diagram problem in O(log n log log n) time and O(n log2n) work (which improves the previous time bound while maintaining the same work bound) or, alternatively, in O(log2n) time and O(n log n) work (which improves the previous work bound while maintaining the same time bound). Our model of computation is the CREW PRAM.

Searching for high-value rare events with uncheatable grid computing

Abstract: High-value rare-event searching is arguably the most natural application of grid computing, where computational tasks are distributed to a large collection of clients (which comprise the computation grid) in such a way that clients are rewarded for performing tasks assigned to them. Although natural, rare-event searching presents significant challenges for a computation supervisor, who partitions and distributes the search space out to clients while contending with “lazy” clients, who don't do all their tasks, and “hoarding” clients, who don't report rare events back to the supervisor. We provide schemes, based on a technique we call chaff injection, for efficiently performing uncheatable grid computing in the context of searching for high-value rare events in the presence of coalitions of lazy and hoarding clients.

Voronoi diagrams for convex polygon-offset distance functions

Abstract: In this paper we develop the concept of a convexpolygon-offset distance function. Using offset as a notion of distance, we show how to compute the corresponding nearest- and furthest-site Voronoi diagrams of point sites in the plane. We provide near-optimal deterministicO(n(logn + log2m) +m)-time algorithms, wheren is the number of points andm is the complexity of the underlying polygon, for computing compact representations of both diagrams.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Random graphs

Abstract: We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Planning Algorithms: Introductory Material

Abstract: Planning algorithms are impacting technical disciplines and industries around the world, including robotics, computer-aided design, manufacturing, computer graphics, aerospace applications, drug design, and protein folding. This coherent and comprehensive book unifies material from several sources, including robotics, control theory, artificial intelligence, and algorithms. The treatment is centered on robot motion planning but integrates material on planning in discrete spaces. A major part of the book is devoted to planning under uncertainty, including decision theory, Markov decision processes, and information spaces, which are the “configuration spaces” of all sensor-based planning problems. The last part of the book delves into planning under differential constraints that arise when automating the motions of virtually any mechanical system. Developed from courses taught by the author, the book is intended for students, engineers, and researchers in robotics, artificial intelligence, and control theory as well as computer graphics, algorithms, and computational biology.

Internet of Things: A Survey on Enabling Technologies, Protocols, and Applications

Abstract: This paper provides an overview of the Internet of Things (IoT) with emphasis on enabling technologies, protocols, and application issues. The IoT is enabled by the latest developments in RFID, smart sensors, communication technologies, and Internet protocols. The basic premise is to have smart sensors collaborate directly without human involvement to deliver a new class of applications. The current revolution in Internet, mobile, and machine-to-machine (M2M) technologies can be seen as the first phase of the IoT. In the coming years, the IoT is expected to bridge diverse technologies to enable new applications by connecting physical objects together in support of intelligent decision making. This paper starts by providing a horizontal overview of the IoT. Then, we give an overview of some technical details that pertain to the IoT enabling technologies, protocols, and applications. Compared to other survey papers in the field, our objective is to provide a more thorough summary of the most relevant protocols and application issues to enable researchers and application developers to get up to speed quickly on how the different protocols fit together to deliver desired functionalities without having to go through RFCs and the standards specifications. We also provide an overview of some of the key IoT challenges presented in the recent literature and provide a summary of related research work. Moreover, we explore the relation between the IoT and other emerging technologies including big data analytics and cloud and fog computing. We also present the need for better horizontal integration among IoT services. Finally, we present detailed service use-cases to illustrate how the different protocols presented in the paper fit together to deliver desired IoT services.

An efficient k-means clustering algorithm: analysis and implementation

Abstract: In k-means clustering, we are given a set of n data points in d-dimensional space R/sup d/ and an integer k and the problem is to determine a set of k points in Rd, called centers, so as to minimize the mean squared distance from each data point to its nearest center. A popular heuristic for k-means clustering is Lloyd's (1982) algorithm. We present a simple and efficient implementation of Lloyd's k-means clustering algorithm, which we call the filtering algorithm. This algorithm is easy to implement, requiring a kd-tree as the only major data structure. We establish the practical efficiency of the filtering algorithm in two ways. First, we present a data-sensitive analysis of the algorithm's running time, which shows that the algorithm runs faster as the separation between clusters increases. Second, we present a number of empirical studies both on synthetically generated data and on real data sets from applications in color quantization, data compression, and image segmentation.