• 제목/요약/키워드: efficient domination

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Some Cycle and Star Related Nordhaus-Gaddum Type Relations on Strong Efficient Dominating Sets

  • Murugan, Karthikeyan
    • Kyungpook Mathematical Journal
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    • 제59권3호
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    • pp.363-375
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    • 2019
  • Let G = (V, E) be a simple graph with p vertices and q edges. A subset S of V (G) is called a strong (weak) efficient dominating set of G if for every $v{\in}V(G)$ we have ${\mid}N_s[v]{\cap}S{\mid}=1$ (resp. ${\mid}N_w[v]{\cap}S{\mid}=1$), where $N_s(v)=\{u{\in}V(G):uv{\in}E(G),\;deg(u){\geq}deg(v)\}$. The minimum cardinality of a strong (weak) efficient dominating set of G is called the strong (weak) efficient domination number of G and is denoted by ${\gamma}_{se}(G)$ (${\gamma}_{we}(G)$). A graph G is strong efficient if there exists a strong efficient dominating set of G. In this paper, some cycle and star related Nordhaus-Gaddum type relations on strong efficient dominating sets and the number of strong efficient dominating sets are studied.

LINEAR AND NON-LINEAR LOOP-TRANSVERSAL CODES IN ERROR-CORRECTION AND GRAPH DOMINATION

  • Dagli, Mehmet;Im, Bokhee;Smith, Jonathan D.H.
    • 대한수학회보
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    • 제57권2호
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    • pp.295-309
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    • 2020
  • Loop transversal codes take an alternative approach to the theory of error-correcting codes, placing emphasis on the set of errors that are to be corrected. Hitherto, the loop transversal code method has been restricted to linear codes. The goal of the current paper is to extend the conceptual framework of loop transversal codes to admit nonlinear codes. We present a natural example of this nonlinearity among perfect single-error correcting codes that exhibit efficient domination in a circulant graph, and contrast it with linear codes in a similar context.

Domination이론에서의 새로운 식과 이의 신뢰성계산에 대한 적용 (New formula in domination theory and it's application for reliability analysis)

  • 이광원;이일재;강신재
    • 한국안전학회지
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    • 제11권1호
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    • pp.16-26
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    • 1996
  • A.Satyanarayana와 다른이들은 [1.2.5]에서 domination이론을 사용하여 네트워크의 정확한 신뢰도 계산을 위한 새로운 topologic formel을 발견하였다. 이들은 이식을 통하여 그래프 G로 표현되는 어떤 시스템이나 네트워크의 신뢰도 계산을 위하여 path 또는 k-tree를 사용한 Inclusion-Exclusion식에 나타나는 항들(=2$^{m}$ -1, m은 path나 k-tree의 수)중 서로 소거되지 않는 항들은 그래프 G의 acyclic k-부분그래프(subgraph)와 1대 1로 상응되며, cyclic-과 k-부분그래프들에 상응되는 항들은 소거되어지거나 Inclusion-Exclusion식에 나타나지 않는 -결국 신뢰도계산에 필요없는- 항들임을 밝혔다. 이들은 이성질을 이용하여 그래프 G의 정확한 신뢰도계산을 위한 빠른 알고리즘을 제시하였다. 이 알고리즘은 결국 그래프 G의 path나 k-tree를 기초로 하는 Inclusion-Exclusion식에서 나타나는 항들중 소거되지 않는 항들에 1:1로 대응하는 acyclic k-subgraph만을 찾아 신뢰도계산을 할수있게 하여 준다. 이때 acyclic k-subgraph들은 각각의 domination을 갖으며, 이들은 Inclusion-Exclusion식에서 대응되는 항의 부호들의 합과 같다. 본 논문에서는 첫째로 신뢰도계산을 위하여 주어진 어떤 그래프 G에서 G를 구성하는 선(edge)을 기초로 하는 어떤 임의로 주어진 family M(G) (예: cutset이나 path, 또는 k-tree 등의 family)에 의한 (부분)그래프의 domination에 대한 성질을 관찰하고 몇가지 식을 유도한후, k-tree의 family K(G)를 기초로 한 어떤 그래프의 domination과 Inclusion-Exclusion식과의 관계를 고찰하고, 이식의 강력함과 응용의 가능성을 A. Satyanarayana의 topologic formel의 재증명을 통하여 보인다.

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SOME CHARACTERIZATIONS OF DOUBY CHORDAL GRAPHS

  • Kim, Chang-Hwa
    • Journal of applied mathematics & informatics
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    • 제5권1호
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    • pp.65-72
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    • 1998
  • Many optimization problems like domination and Steiner tree are NP-complete on chordal graphs but can be solved in polyno-mial time on doubly chordal graphs. Investigating properties of dou-bly chordal graphs probably help to design efficient algorithms for the graphs. We present some characterizations of dobly chordal graphs which are based on clique matrices and neighborhood matrics also men-tioned how a doubly perfect elimination ordering of a doubly chordal graph can be computed from the results.

COMPUTATION OF A (CANONICAL) DOUBLY PERFECT ELIMINATION ORDERING OF A DOUBLY CHORDAL GRAPH

  • Lee, Mahn-Hoon;Kim, Chang-Hwa
    • Journal of applied mathematics & informatics
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    • 제5권2호
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    • pp.329-336
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    • 1998
  • The class of doubly chordal graphs is a subclass of chordal graphs and a superclass of strongly chordal graphs which arise in so many application areas. Many optimization problems like domination and Steiner tree are NP-complete on chordal graps but can be solved in polynomial time on doubly chordal graphs. The central to designing efficient algorithms for doulby chordal graphs is the concept of (canonical)doubly perfect elimination orderings. We present linear time algorithms to compute a (canonical) double perfect elimination ordering of a doubly chordal graph.

마그레브(Maghreb)의 식문화 -알제리아를 중심으로- (Food of Maghreb -Algerian food in particular-)

  • 전희정
    • 한국식생활문화학회지
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    • 제11권5호
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    • pp.651-661
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    • 1996
  • Algeria is located at the Mediterranean coast of north Africa, 90% of its population is concentrated in the coastal area which is mainly devoted to agriculture. Highland steppe and vast desert climate have determined its food culture. Long arab domination has influenced food of Algeria which has also undergone certain impact of Spanish, Turkish and French occupation. A variety of agricultural products, vegetables, fruits, spices and herbs have determined cooking method and food combination of Algeria. It use neither pork nor alcohol. Its main food consists of bread made from wheat flour and couscous cooked with semoule, Mechuwi, roast lamb and chorba, mixed soup are also typical foods of this region. For climatic reason lamb and chicken are prefered. Energy efficient method is applied to cooking through using oil for saute and water for boiling. Under european influence, Algerian salad used dressing for leaf vegetables, root and other kind vegetables were boiled. Serving with cake and cookies as dessert may possibly be the influence from the French occupation. The cake and cookie are made of wheat flour or other grain flour and take a specific form to be fried sweet with honey. Herbs and spices are widely used in cooking which are easily cultivated in household: mint, basil, rosemary, bayleaf, thyme, sage, fennel, marjoram, coriander, celery. Garlic, onion, piment, red pepper, cinammon are also widely used in an ordinary cooking. Reasonable food combination and economic cooking method could be subject of Algerian food study.

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최소위험 종목과 비양의 상관관계를 갖는 종목들 분산투자 포트폴리오 최적화 (Portfolio Optimization of Diversified Investments with Minimum Risk Asset and Non-Positive Correlation Assets)

  • 이상운
    • 한국인터넷방송통신학회논문지
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    • 제22권1호
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    • pp.103-110
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    • 2022
  • 본 논문은 단일 종목에 투자금을 전액 투자하는 것에 비해 다수의 종목에 분산투자하는 것이 투자 위험을 보다 감소시킬 수 있다는 포트폴리오 최적화 문제를 다룬다. 널리 알려진 Markowitz의 수익률에 대한 평균-분산 기법(MV)은 위험요인인 분산(또는 표준편차)을 감소시키기 위해 지배원리를 적용하여 효율적 투자선에 있는 종목들을 대상으로 분산투자하는 포트폴리오를 구성하였다. 반면에, 본 논문에서는 최소표준편차를 가진 종목을 필수 투자종목으로 선정하고, 필수 투자종목과 비양(음의, 무)의 상관관계를 갖는 종목들을 대상으로 포트폴리오를 형성하였다. 제안된 방법을 실험한 결과 MV에 비해 보다 적은 위험(표준편차)을 보였다.

브라질의 인종과 정치: 발생, 전개, 특징 (Race and Politics in Brazil: Occurrence, Development, Characteristics)

  • 김달관
    • 이베로아메리카
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    • 제21권1호
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    • pp.1-55
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    • 2019
  • 브라질에서는 인종에 대한 명확한 개념의 규정이 존재하지 않으면서도 인종차별주의가 존재한다. 즉 명확한 인종의 개념이 없이 인종주의는 존재하기 때문에, 브라질에서 인종문제는 복잡하다고 하겠다. 인종주의는 단순한 사회적 문제가 아니다. 그것은 무엇보다도 경제적 분리, 배제, 주변화 등으로 나타나는 정치적 문제이다. 유럽 식민주의 확대 과정에서부터 인종주의는 브라질의 사회적, 물질적, 심리적, 정치적 지배의 가장 뿌리 깊고 효율적인 통치방식이었다. 이런 관점에서 본 연구는 인종의 정치로서 브라질의 인종주의에 대해 연구하려 한다. 결론적으로 브라질에는 인종에 따른 인종 차별과 인종불평등이 존재한다는 것이다. 이에 따라, 브라질에는 인종에 따른 인종차별과 인종불평등이 존재한다는 것을 연구하기 위해, 제2장은 브라질에서 인종정치의 기원을 살펴본다. 제3장에서는 브라질 사회와 인종에 대해 살펴보고자 한다. 제4장은 브라질의 흑인운동으로서 인종주의에 대한 흑인의 저항을 살펴본다. 제5장의 전반부는 '브라질의 인종불평등'을 살펴보고, 후반부는 '브라질의 인종차별'에 대해 살펴보려 한다. 제6장은 결론부분으로서 브라질의 인종정치의 도전과 한계는 무엇인지 논의하려 한다.

우주법(宇宙法)의 최근동향(最近動向) (Recent Developments in Space Law)

  • 최준선
    • 항공우주정책ㆍ법학회지
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    • 제1권
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    • pp.223-243
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    • 1989
  • The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

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