• Title/Summary/Keyword: local k-coloring

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LOCAL AND MEAN k-RAMSEY NUMBERS FOR THE FAMILY OF GRAPHS

  • Su, Zhanjun;Chen, Hongjing;Ding, Ren
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.909-913
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    • 2009
  • For a family of graphs $\mathcal{H}$ and an integer k, we denote by $R^k(\mathcal{H})$ the corresponding k-Ramsey number, which is defined to be the smallest integer n such that every k-coloring of the edges of $K_n$ contains a monochromatic copy of a graph in $\mathcal{H}$. The local k-Ramsey number $R^k_{loc}(\mathcal{H})$ and the mean k-Ramsey number $R^k_{mean}(\mathcal{H})$ are defined analogously. Let $\mathcal{G}$ be the family of non-bipartite graphs and $T_n$ be the family of all trees on n vertices. In this paper we prove that $R^k_{loc}(\mathcal{G})=R^k_{mean}(\mathcal{G})$, and $R^2(T_n)$ < $R^2_{loc}(T_n)4 = $R^2_{mean}(T_n)$ for all $n\;{\ge}\;3$.

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Coordinated Cognitive Tethering in Dense Wireless Areas

  • Tabrizi, Haleh;Farhadi, Golnaz;Cioffi, John Matthew;Aldabbagh, Ghadah
    • ETRI Journal
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    • v.38 no.2
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    • pp.314-325
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    • 2016
  • This paper examines the resource gain that can be obtained from the creation of clusters of nodes in densely populated areas. A single node within each such cluster is designated as a "hotspot"; all other nodes then communicate with a destination node, such as a base station, through such hotspots. We propose a semi-distributed algorithm, referred to as coordinated cognitive tethering (CCT), which clusters all nodes and coordinates hotspots to tether over locally available white spaces. CCT performs the following these steps: (a) groups nodes based on a modified k-means clustering algorithm; (b) assigns white-space spectrum to each cluster based on a distributed graph-coloring approach to maximize spectrum reuse, and (c) allocates physical-layer resources to individual users based on local channel information. Unlike small cells (for example, femtocells and WiFi), this approach does not require any additions to existing infrastructure. In addition to providing parallel service to more users than conventional direct communication in cellular networks, simulation results show that CCT can increase the average battery life of devices by 30%, on average.

Natural Dyes on Indonesian Traditional Textiles - A Case Study: Geringsing Woven Fabric, In Tenganan Pegeringsingan Village Bali -

  • Widiawati, Dian;Sn, S.;Sn, M.;Rosandini, Morinta;Ds, S.
    • The Research Journal of the Costume Culture
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    • v.20 no.1
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    • pp.111-120
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    • 2012
  • Indonesia has a wealth of traditional textiles that are spread in every corner of its region, each of them has its own characteristics and uniquennes. Among the diversity of decorative and techniques used, there are also peculiarities arising from the coloring techniques, that is staining with natural dyes. The existence and the authenticity of the coloring techniques are still retained in some places in Indonesia until today. Generally, these societies make the fabric-making process as part of the ritual beliefs. One of which are the societies in Tenganan, Bali, an area in Bali which always use fabric as an important part in every traditional ceremony. The fabrics is known by the name Geringsing. The typically color which shown and also the sacred values that accompany make Geringsing a very special woven fabric and cannot be found in other areas. This is one of the local geniuses that need to be preserved. In addition to its unique techniques and special materials, Geringsing woven also keeps its myth and its philosophy. The emersion of Geringsing woven closely related to the community trust in God Indra as the main protector deity. The necessary initial process of making Geringsing is holding special ceremony attended by various circles of Tenganan village society. People in Tenganan believe that Geringsing is a precious heritage avoiding all diseases and disorders of evil spirits.

Color Characteristics of Silk Fabrics Dyed with Natural Red Dyes Without a Mordant (적색계 천연염료를 이용한 견직물 무매염 염색의 염색성)

  • Kim, Hyo-Jin;Lee, Joo-Hyeon
    • Journal of Digital Convergence
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    • v.16 no.12
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    • pp.593-602
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    • 2018
  • The purpose of this study was to investigate the coloring properties of non-mordant dyes by examining local literature on silk fabric dyeing using red-colored natural dyes. Natural dyes can be prepared from the following 8 materials: purple-fleshed sweet potato, Impatiens balsamina, mulberry, fruits of Ligustrum japonicum Thunb, guava leaves, dansam, hibiscus flowers, and pruned branches of Prunus persica. To examine the surface color calculated $L^*$, $a^*$, $b^*$, ${\Delta}E^*$, and K/S value and H V/C. The variables considered in the dyeing experiment were dye concentration, dyeing temperature, dyeing time, and number of dyeing iterations, which were varied to evaluate the dyeing properties and color characteristics. As a result, the abovementioned variables, dye affinity, and red color expression were directly proportional to one another. In this study, it was found that red coloring can be obtained with natural dyes; moreover, excellent dyeing was achieved without the need for repeated dyeing or mordanting processes, which cause environmental pollution.

The Dyeability of Extract from Opuntia Ficusindica var. Saboten fruits (백년초열매 추출물의 염색성)

  • Kim, In-Young;Lee, So-Hee;Song, Wha-Soon
    • Textile Coloration and Finishing
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    • v.19 no.6
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    • pp.1-6
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    • 2007
  • Opuntia Ficus has been an epiphyte plant since it was introduced in Cheju island as an ornamental plant two hundred years ago. And now it is grown as many as it is designated to local souvenir No.35. The fruit of this plant contains red-purple sap, which is due to be used in coloring clothes. This study aims at confirmation of use possibility as eco-friendly dyeing stuffs on extract from opuntia ficus fruits and contributing to the practical use of natural dyeing. Thus this study was investigated the dyeability of extract from opuntia ficus fruits on the silk fabric. Antioxidants were used ascorbic acid, L-cysteine, prophyl gallete. After dyeing, K/S and dye fastness were measured. The results were as follows; Maximum absorption band of extract from opuntia ficus fruits was 534.5nm. The appropriate dyeing condition was bath ratio 50:1, dyeing temperature $30^{\circ}C$, dyeing concentration 50%, dyeing time 50min, pH 3,concentration of all antioxidants 3%. Addition of antioxidants brought increase of K/S value. And K/S value and dye fastness had the greatest value when ascorbic acid was added

Inhibitory Effects of Herbal Extracts on Dopa Oxidase Activity of Tyrosinase

  • Shin, Nam-Ho;Lee, Kyong-Soon;Kang, Seh-Hoon;Min, Kyung-Rak;Lee, Seung-Ho;Kim, Young-Soo
    • Natural Product Sciences
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    • v.3 no.2
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    • pp.111-121
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    • 1997
  • Tyrosinase catalyzes the rate-limiting steps in melanin biosynthesis which is involved in skin-coloring and local hyperpigmentation of human beings, and unfavorable darkening of food products, Inhibitory effects on 3,4-dihydroxy-phenylalanine (dopa) oxidase activity of tyrosinase by 594 kinds of herbal extracts prepared from herbal medicines and wild plants in Korea were estimated. Two herbal extracts prepared from radicis cortex of Morus alba and rhizoma of Curcuma longa were selected as those exhibiting potent inhibitory effects on the enzyme activity. These herbal extracts were subjected to sequential fractionations with methylene chloride, ethyl acetate, n-butanol, and polar residue. The inhibitory effects on dopa oxidase activity of tyrosinase were shown in ethyl acetate fraction of Morus alba, and in methylene chloride fraction of Curcuma langa. The ethyl acetate fraction of Marus alba exhibited 50% of inhibition on dopa oxidase activity of tyrosinase at the concentration of 12 ${\mu}g/ml$, and methylene chloride fraction of Curcuma langa at 51 ${\mu}g/ml$.

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Dyes and Dyeing in Korea, from 1876 to 1910 (개화기의 염료와 염색업에 관한 연구)

  • Kim, Soon-Young
    • Journal of the Korean Society of Costume
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    • v.60 no.9
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    • pp.77-94
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    • 2010
  • It was the era, from 1876 to 1910, that some dramatic changes, including an influx of foreign dyes and the beginning of the modern dyeing manufacture, happened in Korea. This paper explores what dyes were sold in the market in this period, who was the main seller of the goods, and how the dyers produced their products. A wide range of natural dye stuffs coexisted with the various kinds of aniline dyes, alizarin dye and synthetic indigo in the market. Coloring materials had been sold by hwapi-jeon, a group of official merchants who acquired a privilege of monopoly from the government. However, the dyes were also traded by sang-jeon and yakguk merchants in the nineteenth century. Most of the synthetic dyes sold in Korea were produced in Germany or in Japan later, and imported in large amount by Chinese, Japanese and German merchants. Yet there also existed Korean merchants and peddlers who sold the goods to the local consumers. Dyers were male and female who belonged to the middle class. They received the orders and payments from the government or merchants. Not only did they dye textiles, threads, cotton, paper and leather, but they also redyed clothes. Indigo dyers were differentiated from other dyers. Modern dyeing manufacture, which was presumably forced to keep pace with the productivity of the weaving process, appeared in the 1900s. It was a branch of the modern weaving manufacture.

Ecological Responses of Plants to Climate Change: Research Trends and Its Applicability in Korea (기후변화에 대한 식물의 생태적 반응: 연구동향과 한국에서의 적용가능성)

  • Kang, Hyesoon
    • Korean Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.319-331
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    • 2013
  • Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

Product Design and Development Research Culture that is Based on Local Cultural Assets Baekje - Focusing on the Kitchenware Handle Design - (백제권 문화재를 기반으로 한 문화상품 디자인 개발연구 - 주방용품 손잡이 디자인을 중심으로 -)

  • Kim, Chung Ho;Kang, Ho Yang
    • Journal of the Korea Furniture Society
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    • v.23 no.4
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    • pp.364-371
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    • 2012
  • I designed a dietary life kitchen utensils which is focused by the shape of split bamboo that has meaning of health and safety and the shaman who is the religion and incantation performer, and who solve problems, which are impossible to solve in common methods, by borrowing the power and granting the meaning which is connected with transcendent existence and principal. Having closest relation with human being's diet culture is being changed with adding beauty instead of the part of simple practical aspect in our normal life. I tried to show incantation effect with keeping the characteristic of kitchen utensils by granting the symbolic meaning of shamanism which is the shelter that is projected the desire of human beings. the materials were produced of an ebony and steel and varnished with lacquer for coloring. For hand shape, which is hard to treat in irregular forms, the religious image of shamanism was formed by casting which expresses the touch of an ebony and the cold characteristic of metal. an overall design doesn't detail excessively distort or largely transform the form of dietary utensils, keeps its individuality, and emphasizes the image by figuring a grip part which a human can see and a body can approach. in addition, I try to show a point that shamanism has affected human life for long time and symbolic meaning of bamboo-shape shows health and safety. And these things vest with each dietary life tools and should be the role of enzyme about the effect of human life.

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