In this paper, we investigate the structure of minimum vertex and edge cuts of distance-regular digraphs. We show that each distance-regular digraph Γ, different from an undirected cycle, is super edge-connected, that is, any minimum edge cut of Γ is the set of all edges going into (or coming out of) a single vertex. Moreover, we will show that except for undirected cycles, any distance regular...

k≤m Ek and m is minimum. Two related and reasonably well-studied problems are the Minimum Biclique Cover (MBC), where Hk are required to be bicliques (i.e. complete bipartite subgraphs) [4,3,2,1] and the Minimum Cut Cover (MCC), where Hk are cutsets, namely not required to be connected. Both problems are NP-hard. To the best of our knowledge, whether the MBGC is NP-hard or not is currently unkn...

We present a fully automatic segmentation method to extract media-adventitia border in IVUS images. We use a double-interface automatic graph cut technique to prevent the extraction of mediaadventitia border from being distracted by those image features. Novel cost functions are derived from using a combination of symmetric and asymmetric local phase features with complementary texture features...

An off-the-shelf low cost laser sensor was tested and evaluated both in laboratory and field conditions. The sensor identified the angular and straight edges of the laboratory test surface and replicated the straight edge profile with an error of 4%. In field conditions, the sensor identified three types of cut crop edges (wheat, alfalfa and corn) and replicated distinct shapes (triangle, curve...

Proof. “⇐” Suppose G has a cut vertex v. Then Gr v has at least two components G1 and G2. Given vertices vi ∈ V (Gi), i = 1, 2. Each path connecting v1 and v2 must contain the vertex v. So any two paths between v1 and v2 must contain the common internal vertex v. This is a contradiction. “⇒” Given two distinct vertices u and v of G, let d(u, v) denote the distance between u and v. We apply indu...

For a subset S of edges in a connected graph G, the set S is a k-restricted edge cut if G− S is disconnected and every component of G− S has at least k vertices. The k-restricted edge connectivity of G, denoted by λk(G), is defined as the cardinality of a minimum k-restricted edge cut. A connected graph G is said to be λk-connected if G has a k-restricted edge cut. Let ξk(G) = min{|[X, X̄ ]| : |...

This paper presents a video cut detection algorithm using multi-level Hausdor distance histograms (HDH). Hausdor distance is obtained by comparing edge points of successive frames, wherein the edge information is extracted from compressed frames directly. The use of Hausdor distance histogram instead of the comparison of entering/exiting edge pixel counts [9] makes the algorithm more robust to ...

This article presents an accurate and automatic approach to extract a liver from CT images for oncologic surgery planning. Our algorithm exploits graph cut segmentation, which perform global optimization. The quality of graph cut segmentation strongly depends on the edge image that gives prior knowledge about locations of foreground and background regions. In order to get a good edge image, a l...

Given a hypergraph, a partition of its vertex set and an integer k, find a minimum number of graph edges to be added between different members of the partition in order to make the hypergraph k-edge-connected. This problem is a common generalization of the following two problems: edge-connectivity augmentation of graphs with partition constraints (J. Bang-Jensen, H. Gabow, T. Jordán, Z. Szigeti...

In this study, turning operation of Monel K500 copper-nickel super-alloy was evaluated. Ceramic cutting tools with two different cutting noses (conventional and wiper) were utilized. At first, the experimental tests were designed by using central composite design method. After implementation of the tests, the statistical models for output data (surface roughness, cutting force, and flank wear) ...