• Title/Summary/Keyword: graph $(k_0,\

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Correlation analysis between energy indices and source-to-node shortest pathway of water distribution network (상수도관망 수원-절점 최소거리와 에너지 지표 상관성 분석)

  • Lee, Seungyub;Jung, Donghwi
    • Journal of Korea Water Resources Association
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    • v.51 no.11
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    • pp.989-998
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    • 2018
  • Connectivity between water source and demand node can be served as a critical system performance indicator of the degree of water distribution network (WDN)' failure severity under abnormal conditions. Graph theory-based approaches have been widely applied to quantify the connectivity due to WDN's graph-like topological feature. However, most previous studies used undirected-unweighted graph theory which is not proper to WDN. In this study, the directed-weighted graph theory was applied for WDN connectivity analyses. We also proposed novel connectivity indicators, Source-to-Node Shortest Pathway (SNSP) and SNSP-Degree (SNSP-D) which is an inverse of the SNSP value, that does not require complicate hydraulic simulation of a WDN of interest. The proposed SNSP-D index was demonstrated in total 42 networks in J City, South Korea in which Pearson Correlation Coefficient (PCC) between the proposed SNSP-D and four other system performance indicators was computed: three resilience indexes and an energy efficiency metric. It was confirmed that a system representative value of the SNSP-D has strong correlation with all resilience and energy efficiency indexes (PCC = 0.87 on average). Especially, PCC was higher than 0.93 with modified resilience index (MRI) and energy efficiency indicator. In addition, a multiple linear regression analysis was performed to identify the system hydraulic characteristic factors that affect the correlation between SNSP-D and other system performance indicators. The proposed SNSP is expected to be served as a useful surrogate measure of resilience and/or energy efficiency indexes in practice.

A CONSTRUCTION OF COMMUTATIVE NILPOTENT SEMIGROUPS

  • Liu, Qiong;Wu, Tongsuo;Ye, Meng
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.3
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    • pp.801-809
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    • 2013
  • In this paper, we construct nilpotent semigroups S such that $S^n=\{0\}$, $S^{n-1}{\neq}\{0\}$ and ${\Gamma}(S)$ is a refinement of the star graph $K_{1,n-3}$ with center $c$ together with finitely many or infinitely many end vertices adjacent to $c$, for each finite positive integer $n{\geq}5$. We also give counting formulae to calculate the number of the mutually non-isomorphic nilpotent semigroups when $n=5$, 6 and in finite cases.

Feeding Behaviors of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Changing of Feeding Behaviors to Cyantraniliprole (EPG를 이용한 담배가루이(Bemisia tabaci)의 섭식행동과 Cyantraniliprole에 대한 섭식변화)

  • Kwon, Hye-Ri;Youn, Young-Nam
    • Korean Journal of Agricultural Science
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    • v.41 no.2
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    • pp.119-124
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    • 2014
  • Feeding behaviors of the sweet potato whitefly, Bemisia tabaci, and changing of their feeding behaviors were recorded and analyzed with an Electrical Penetration Graph (EPG) analysis against cyantraniliprole. The characteristic patterns of feeding behaviors investigated were as follows; NP (non probing), pathway phase waveform, waveform of feeding xylem. In results, B. tabaci did not almost feeding the phloem. And It was not appeared potential drop during recording time. It was predominantly indicated pathway activity waveform and waveform of xylem feeding. After treatment of cyantraniliprole with recommended concentrations to tomato plants, EPG waveforms were recorded during 3 hours. Cyantraniliprole treatment showed longer time to first feeding xylem than untreated (P=0.043). It was showed shorter duration of first feeding xylem than untreated (P=0.017). And it was showed longer NP (non-probing) time than untreated. Consequently, It was supposed that cyantraniliprole was effect of anti-feeding or avoidance to B. tabaci.

Complexity Issues of Perfect Roman Domination in Graphs

  • Chakradhar, Padamutham;Reddy, Palagiri Venkata Subba
    • Kyungpook Mathematical Journal
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    • v.61 no.3
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    • pp.661-669
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    • 2021
  • For a simple, undirected graph G = (V, E), a perfect Roman dominating function (PRDF) f : V → {0, 1, 2} has the property that, every vertex u with f(u) = 0 is adjacent to exactly one vertex v for which f(v) = 2. The weight of a PRDF is the sum f(V) = ∑v∈V f(v). The minimum weight of a PRDF is called the perfect Roman domination number, denoted by γRP(G). Given a graph G and a positive integer k, the PRDF problem is to check whether G has a perfect Roman dominating function of weight at most k. In this paper, we first investigate the complexity of PRDF problem for some subclasses of bipartite graphs namely, star convex bipartite graphs and comb convex bipartite graphs. Then we show that PRDF problem is linear time solvable for bounded tree-width graphs, chain graphs and threshold graphs, a subclass of split graphs.

REMARKS ON DIGITAL HOMOTOPY EQUIVALENCE

  • Han, Sang-Eon
    • Honam Mathematical Journal
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    • v.29 no.1
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    • pp.101-118
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    • 2007
  • The notions of digital k-homotopy equivalence and digital ($k_0,k_1$)-homotopy equivalence were developed in [13, 16]. By the use of the digital k-homotopy equivalence, we can investigate digital k-homotopy equivalent properties of Cartesian products constructed by the minimal simple closed 4- and 8-curves in $\mathbf{Z}^2$.

ROLLING STONES WITH NONCONVEX SIDES II: ALL TIME REGULARITY OF INTERFACE AND SURFACE

  • Lee, Ki-Ahm;Rhee, Eun-Jai
    • Journal of the Korean Mathematical Society
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    • v.49 no.3
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    • pp.585-604
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    • 2012
  • In this paper we consider the evolution of the rolling stone with a rotationally symmetric nonconvex compact initial surface ${\Sigma}_0$ under the Gauss curvature flow. Let $X:S^n{\times}[0,\;{\infty}){\rightarrow}\mathbb{R}^{n+1}$ be the embeddings of the sphere in $\mathbb{R}^{n+1}$ such that $\Sigma(t)=X(S^n,t)$ is the surface at time t and ${\Sigma}(0)={\Sigma}_0$. As a consequence the parabolic equation describing the motion of the hypersurface becomes degenerate on the interface separating the nonconvex part from the strictly convex side, since one of the curvature will be zero on the interface. By expressing the strictly convex part of the surface near the interface as a graph of a function $z=f(r,t)$ and the non-convex part of the surface near the interface as a graph of a function $z={\varphi}(r)$, we show that if at time $t=0$, $g=\frac{1}{n}f^{n-1}_{r}$ vanishes linearly at the interface, the $g(r,t)$ will become smooth up to the interface for long time before focusing.

Summarizing the Differences in Chinese-Vietnamese Bilingual News

  • Wu, Jinjuan;Yu, Zhengtao;Liu, Shulong;Zhang, Yafei;Gao, Shengxiang
    • Journal of Information Processing Systems
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    • v.15 no.6
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    • pp.1365-1377
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    • 2019
  • Summarizing the differences in Chinese-Vietnamese bilingual news plays an important supporting role in the comparative analysis of news views between China and Vietnam. Aiming at cross-language problems in the analysis of the differences between Chinese and Vietnamese bilingual news, we propose a new method of summarizing the differences based on an undirected graph model. The method extracts elements to represent the sentences, and builds a bridge between different languages based on Wikipedia's multilingual concept description page. Firstly, we calculate the similarity between Chinese and Vietnamese news sentences, and filter the bilingual sentences accordingly. Then we use the filtered sentences as nodes and the similarity grade as the weight of the edge to construct an undirected graph model. Finally, combining the random walk algorithm, the weight of the node is calculated according to the weight of the edge, and sentences with highest weight can be extracted as the difference summary. The experiment results show that our proposed approach achieved the highest score of 0.1837 on the annotated test set, which outperforms the state-of-the-art summarization models.

Sanitary sewer flow characteristics through a depth-velocity scatter graph analysis (수위-유속 분산 그래프를 통한 하수흐름 특성 분석)

  • Son, Jooyoung;Oh, Jeill
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.6
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    • pp.647-655
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    • 2014
  • To perform long-term sewer monitoring, It is important to understand the nature of the wastewater flow that occurs at the point on early stage of the monitor and to prevent in advance a problem which may caused. We can infer the flow properties and external factors by analyzing the scatter graph obtained from the measured data flow rate monitoring data since an field external factor affecting the sewage flow is reflected in the flow rate monitoring data. In this study, Selecting the three points having various external factors, and we Inferred the sewer flow characteristics from depth-velocity scatter graph and determined the analysis equation for the dry-weather flow rate data. At the'point 1' expected non-pressure flow, we were able to see the drawdown effect caused by the free fall in the manhole section. At the'point 2', existed weir and sediments, there was backwater effect caused by them, and each of size calculated from the scatter graph analysis were 400 mm and 130 mm. At the'Point 3', there is specific flow pattern that is coming from flood wave propagation generated by the pump station at upstream. In common, adequate equations to explain the dry weather flow data are flume equation and modified manning equation(SS method), and the equations had compatibility for explaining the data because all of $R^2$ values are over 0.95.

Growth of Clostridium thermobutyricum: a Cellulolytic Thermophile

  • Kuk, Seung-Uk;Hong, Seung-Suh
    • Journal of Microbiology and Biotechnology
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    • v.2 no.4
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    • pp.293-296
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    • 1992
  • Increased concentrations of yeast extract led to increased growth yields and faster growth rates of the newly isolated Clostridium thermobutyricum. This species produced butyrate as its main fermentation product from glucose as well as from yeast extract. In the presence of peptone or tyrptone and during growth on agar, up to 70% of the cells sporulated. Growth yields were 30 and 55 g per mole glucose in the presence of 0.05 and 2.0% yeast extract, respectively. The Arrhenius graph was biphasic, exhibiting an intermediary plateau around $38^{\circ}C$ with a concomitant change in the Arrhenius energy. The optimum temperature was $55^{\circ}C$. An unusually sharp decline in the growth rate occurred above $59^{\circ}C$ .

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Unpaired Many-to-Many Disjoint Path Covers in Hypercube-Like Interconnection Networks (하이퍼큐브형 상호연결망의 비쌍형 다대다 서로소인 경로 커버)

  • Park, Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.10
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    • pp.789-796
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    • 2006
  • An unpaired many-to-many k-disjoint nth cover (k-DPC) of a graph G is a set of k disjoint paths joining k distinct sources and sinks in which each vertex of G is covered by a path. Here, a source can be freely matched to a sink. In this paper, we investigate unpaired many-to-many DPC's in a subclass of hpercube-like interconnection networks, called restricted HL-graphs, and show that every n-dimensional restricted HL-graph, $(m{\geq}3)$, with f or less faulty elements (vertices and/or edges) has an unpaired many-to-many k-DPC for any $f{\geq}0\;and\;k{\geq}1\;with\;f+k{\leq}m-2$.