45898949
Elliptical object detection by using its geometric properties
Abstract A simple algorithm for ellipse detection in an image is proposed. The new method consists of three steps: (1) detect the elliptical center by using its symmetrical property; (2) identify the elliptical points by using a simple geometric property; and (3) estimate the five parameters ( x c , y c , A , B , θ ) by using a least sum of squares fitting method. The new method has been tested on both the synthetic and real images. The experimental results show that the method is reliable and accurate.
39105458
A New Edge Detection Method Through Template Matching
This paper reviews some gradient edge detection methods and proposes a new detector — the template matching edge detector (TMED). This detector utilizes the concepts of pattern analysis and the template matching of 3×3 masks. A set of performance criteria was used to evaluate the gradient edge detectors as well as the template matching edge detector. The results indicate that the new method is superior to the other gradient edge detectors. In addition, the template matching edge detector has also demonstrated good performance on noisy images. It can obtain very precise edge detection of single pixel width.
205131274
Performance evaluation of some noise reduction methods
Abstract In this paper, a quantitative evaluation of some noise reduction methods is presented. It first classifies the existing local noise reduction techniques by the use of neighbors and statistics and proposes some new filtering techniques. Subsequently, five performance evaluation criteria including processing time, mean distortion, mean busyness, stability, and correct processing ratio are discussed. By using these performance evaluation criteria, an experiment that involves four factors (test image, noise, mask size, and iteration) was designed to evaluate the performance of the local noise reduction methods. The results indicate that some new local noise reduction techniques have performance better than that of the standard existing techniques under certain criteria.
35736521
Collision Attack and Pseudorandomness of Reduced-Round Camellia
11797984
A greedy approximation for minimum connected dominating sets
Given a graph, a connected dominating set is a subset of vertices such that every vertex is either in the subset or adjacent to a vertex in the subset and the subgraph induced by the subset is connected. A minimum connected dominating set is such a vertex subset with minimum cardinality. In this paper, we present a new one-step greedy approximation with performance ratio ln δ + 2 where δ is the maximum degree in the input graph. The interesting aspect is that the greedy potential function of this algorithm is not supmodular while all previously known one-step greedy algorithms with similar performance have supmodular potential functions.
26307616
Stability analysis on active queue management algorithms in routers
Numerous works have complained the sensitivity to network load and instability of random early detection (RED), an active queue management (AQM) scheme, under various network configurations. In this work, we focus on our investigation on the stability of AQM in routers. By modeling the close-looped congestion control systems in a differential fluid flow model, we reach the sufficient and necessary condition to stabilize the dynamical system. By exploring the convergence region and root-locus of the system and studying the parameter effects of RED in various network simulation conditions, we show the limits of RED in nature and argue against deploying RED in high-speed switches.
29304679
Super line-connectivity of consecutive-d digraphs
Abstract The concept of a consecutive- d digraph was proposed by Du, Hsu and Hwang as a generalization of many digraphs, such as de Bruijn digraphs, Kautz digraphs, and Imase-Itoh digraphs, which contain many hamiltonian digraphs with near-minimum diameter and near-maximum connectivity. In this paper, we show sufficient conditions for modified consecutive- d digraphs to have super line-connectivity.
39315822
A Special Case for Subset Interconnection Designs
Abstract Given a set X and subsets X1, …, Xm, we consider the problem of finding a graph G with vertex set X and the minimum number of edges such that for i = 1,…,m, the subgraph G, induced by Xi is connected. We show that in the special case that every point in X appears in at most three Xi's, the problem is still MAX SNP-complete; however, there exists a polynomial-time approximation within a factor of 5 3 from optimal. As an intermediate result, we also show that the vertex cover problem in cubic graphs is MAX SNP-completc.