89 research outputs found

    An Efficient Local Search for the Minimum Independent Dominating Set Problem

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    In the present paper, we propose an efficient local search for the minimum independent dominating set problem. We consider a local search that uses k-swap as the neighborhood operation. Given a feasible solution S, it is the operation of obtaining another feasible solution by dropping exactly k vertices from S and then by adding any number of vertices to it. We show that, when k=2, (resp., k=3 and a given solution is minimal with respect to 2-swap), we can find an improved solution in the neighborhood or conclude that no such solution exists in O(n Delta) (resp., O(n Delta^3)) time, where n denotes the number of vertices and Delta denotes the maximum degree. We develop a metaheuristic algorithm that repeats the proposed local search and the plateau search iteratively, where the plateau search examines solutions of the same size as the current solution that are obtainable by exchanging a solution vertex and a non-solution vertex. The algorithm is so effective that, among 80 DIMACS graphs, it updates the best-known solution size for five graphs and performs as well as existing methods for the remaining graphs

    A Polynomial-Delay Algorithm for Enumerating Connectors Under Various Connectivity Conditions

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    We are given an instance (G,I,sigma) with a graph G=(V,E), a set I of items, and a function sigma:V -> 2^I. For a subset X of V, let G[X] denote the subgraph induced from G by X, and I_sigma(X) denote the common item set over X. A subset X of V such that G[X] is connected is called a connector if, for any vertex v in VX, G[X cup {v}] is not connected or I_sigma(X cup {v}) is a proper subset of I_sigma(X). In this paper, we present the first polynomial-delay algorithm for enumerating all connectors. For this, we first extend the problem of enumerating connectors to a general setting so that the connectivity condition on X in G can be specified in a more flexible way. We next design a new algorithm for enumerating all solutions in the general setting, which leads to a polynomial-delay algorithm for enumerating all connectors for several connectivity conditions on X in G, such as the biconnectivity of G[X] or the k-edge-connectivity among vertices in X in G

    Polynomial-delay Enumeration Algorithms in Set Systems

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    We consider a set system (V,C2V)(V, {\mathcal C}\subseteq 2^V) on a finite set VV of elements, where we call a set CCC\in {\mathcal C} a component. We assume that two oracles L1\mathrm{L}_1 and L2\mathrm{L}_2 are available, where given two subsets X,YVX,Y\subseteq V, L1\mathrm{L}_1 returns a maximal component CCC\in {\mathcal C} with XCYX\subseteq C\subseteq Y; and given a set YVY\subseteq V, L2\mathrm{L}_2 returns all maximal components CCC\in {\mathcal C} with CYC\subseteq Y. Given a set II of attributes and a function σ:V2I\sigma:V\to 2^I in a transitive system, a component CCC\in {\mathcal C} is called a solution if the set of common attributes in CC is inclusively maximal; i.e., vCσ(v)vXσ(v)\bigcap_{v\in C}\sigma(v)\supsetneq \bigcap_{v\in X}\sigma(v) for any component XCX\in{\mathcal C} with CXC\subsetneq X. We prove that there exists an algorithm of enumerating all solutions (or all components) in delay bounded by a polynomial with respect to the input size and the running times of the oracles.Comment: arXiv admin note: substantial text overlap with arXiv:2004.0190

    Distribution and Localization of Endocrine Cells in the Human Gastro-intestinal Tract -In Relation to Histogenesis of Rectal Carcinoid-

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    The distribution of endocrine cells in the human intestine was studied by immunostaining using the labeled avidinbiotin technique. The total number of endocrine cells was abundant in the proximal portion of the small intestine and the distal portion of the large intestine. Gastrin, cholecystokinin, and motilin immunoreactive cells were localized in the proximal portion of the small intestine. Peptide YY, serotonin, and glucagon/glicentin immunoreactive cells were distributed more abundantly in the lower large intestine. The serotonin and somatostatin concentrations in the colonic mucosa determined by high-performance liquid chromatography and radioimmunoassay were higher in the distal than proximal portion of the large intestine, being in correlation with the distribution of serotonin and somatostatin immunoreactive cells estimated by immunostaining. Therefore, the regional differences in the number of endocrine cells and the mucosal concentrations of the hormones probably reflect differences in the physiological functions of different regions of the gut. Not many endocrine cells with unknown peptides and animes and immature endocrine cells were present in the lower large intestine. Therefore, the frequent occurrence of carcinoids in the rectum is difficult to explain by the quantitative dominance of endocrine cells alone in the rectal mucosa, and other factors are considered to need evaluation

    Ferrocenylnaphthalene Diimide-Based Electrochemical Detection of Aberrant Methylation in hTERT Gene

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    Since aberrant methylation at CpG sites is linked to the silencing of tumor suppressor genes, DNA methylation analysis is important for cancer diagnosis. We developed ferrocenylnaphthalene diimide (FND), which has two ferrocenyl moieties at the substituent termini, as an electrochemical indicator for hybridized DNA duplexes. In this study, we attempted to detect aberrant methylation of human telomerase reverse transcriptase gene (hTERT), an efficient cancer marker, using FND-based hybridization coupled with electrochemical detection via a multi-electrode chip

    Fluorescence-guided bone resection by using Visually Enhanced Lesion Scope in diffuse chronic sclerosingosteomyelitis of the mandible: clinical and pathological evaluation

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    Diffuse chronic sclerosingosteomyelitis (DCSO) is a refractory disease, becausethe etiology and pathogenesis remain poorly understood and to determine the border betweenunhealthy boneandhealthybone is difficult. However, progressive inflammation, clinical symptoms and a high recurrence rate of DCSO were the reasons for surgical treatment. We report a case of a 66-year old woman with DCSO of the right side of mandible who was treated with hemimandibulectomy and simultaneous reconstruction by vascularized free fibula flap. After preoperative administration of minocycline for 1 month, the bone fluorescence was successfully monitored by using a Visually Enhanced Lesion Scope (VELscope®). Intraoperatively, we could determine the resection boundaries. We investigated the clinical and histopathological findings. The fluorescence findings were well correlated with histopathological findings. Using a VELscope®was handy and useful to determine the border between DCSO lesion andhealthybone. The free fibula flap under the minocycline-derived bone fluorescence by using a VELscope®offered a good quality of mandibular bone and the successful management of an advanced and refractory DCSO
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