• Title/Summary/Keyword: Knot

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노트수에 의한 프로그램 복잡성 개선

  • No, Cheol-U
    • ETRI Journal
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    • v.5 no.3
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    • pp.16-25
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    • 1983
  • Increasing importance is being attached to the idea of measuring software characteristics. This paper deals with following things. First, a relation of program and flow graph is discussed. It describes a theoretic complexity measure and illustrates how it can be used to manage and control program complexity. Second, cyclomatic complexity measure is discussed. The complexity is independent of physical size and depends only on the decision structure of a program. Third, consider a knot which defines crossing point and provide the ordering of the nodes to make the transition from a two dimensional graph to a one dimensional program. A program modules that can improve FORTRAN IV program text is tested by knot counting and its control complexity is improved.

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Lower Bounds on Boundary Slope Diameters for Montesinos Knots

  • Ichihara, Kazuhiro;Mizushima, Shigeru
    • Kyungpook Mathematical Journal
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    • v.49 no.2
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    • pp.321-348
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    • 2009
  • In this paper, we give two lower bounds on the diameter of the boundary slope set of a Montesinos knot. One is described in terms of the minimal crossing numbers of the knots, and the other is related to the Euler characteristics of essential surfaces with the maximal/minimal boundary slopes.

A Newly Recorded Turfgrass Pest, Root-knot Nematode, Meloidogyne incognita, in Korean Golf Courses (골프장의 신 해충, 고구마뿌리혹선충의 발견)

  • 추호렬;이동운;김형환;박지웅;성영탁;정영기
    • Asian Journal of Turfgrass Science
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    • v.12 no.2
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    • pp.107-112
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    • 1998
  • 우리나라 골프장의 잔디 가해 해충과 천적을 조사하던 중 농림작물의 중요해충인 고구마뿌리혹선충을 Zoysia잔디에서 발견하였다. 고구마뿌리혹선충에 감염된 잔디는 새 뿌리가 발육하지 못하고 뭉툭하게 되어 황화현상과 함께 전반적으로 생육이 부진하였다. 감염된 잔디의 종은 들잔디(Zoyais japonica)와 금잔디(Zoysia matrella), 버뮤다글라스(Cynodon sp.)였다. 그리고 Z. japonica는 고구마뿌리혹선충의 새로운 기주로 기록된다. 조사 골프장의 대부분이 정도의 차이는 있었지만 피해를 받고 있었다. 잔디에서 뿌리혹선충이 기록되기는 우리나라에서는 처음이다.

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REPRESENTATIONS OF n-FOLD CYCLIC BRANCHED COVERINGS OF (1, 1)-KNOTS UP TO 10 CROSSINGS AS DUNWOODY MANIFOLDS

  • Kim, Geunyoung;Lee, Sang Youl
    • East Asian mathematical journal
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    • v.38 no.1
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    • pp.107-127
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    • 2022
  • In this paper, we discuss the relationship between doubly-pointed Heegaard diagrams of (1, 1)-knots in lens spaces and Dunwoody 3-manifolds, and then give explicit representations of n-fold cyclic branched coverings of all (1, 1)-knots in S3 up to 10 crossings in Rolfsen's knot table as Dunwoody 3-manifolds.

NEW FAMILIES OF HYPERBOLIC TWISTED TORUS KNOTS WITH GENERALIZED TORSION

  • Keisuke, Himeno;Masakazu, Teragaito
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.1
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    • pp.203-223
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    • 2023
  • A generalized torsion element is an obstruction for a group to admit a bi-ordering. Only a few classes of hyperbolic knots are known to admit such an element in their knot groups. Among twisted torus knots, the known ones have their extra twists on two adjacent strands of torus knots. In this paper, we give several new families of hyperbolic twisted torus knots whose knot groups have generalized torsion. They have extra twists on arbitrarily large numbers of adjacent strands of torus knots.

Control of Root-Knot Nematode(Meloidogyne incognita Chitwood) by Root Zone Warming System (지중가온시설을 이용한 고구마뿌리흑선충 방제)

  • 신용습;연일권;최성국;최부술;이우승
    • Journal of Bio-Environment Control
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    • v.7 no.2
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    • pp.139-143
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    • 1998
  • This experiment was conducted to investigate the effect of soil heating on control of root-knot nematode(Meloidogyne incognita Chitwood) by root zone warming system. Root zone was warmed by hot water flowing through pipe set at 35cm depth from the ridge The lowest soil temperatures at 20cm depth were set at 3$0^{\circ}C$, 4$0^{\circ}C$, $50^{\circ}C$ and non-warming. under soil submerging condition and non-submerging condition. Soil heating was done for 5 days(120 hours) from Aug. 1 to Aug. 5. The root-knot nematode juvenile densities of 4$0^{\circ}C$ under submerging condition. and $50^{\circ}C$ under non-submerging condition were 0 which was expected lower than the economic injury level. The contents of OM P$_2$ $O_{5}$, Ca Mg and EC in soil were decreased by root zone warming The EC was considerably lowered under submerging condition.

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Screening of Tomato Cultivars Resistant to Root-knot Nematode, Meloidogyne incognita (고구마 뿌리혹선충 저항성 토마토 품종 스크리닝)

  • Kim, Hyeong-Hwan;Cho, Myoung-Rae;Kang, Taek-Joon;Jung, Jae-A;Han, You-Kyoung
    • Research in Plant Disease
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    • v.16 no.3
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    • pp.294-298
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    • 2010
  • Thirty-two tomato cultivars, eleven cherry tomato cultivars and eight rootstock tomato cultivars were inoculated with Meloidogyne incognita, to evaluate tomato cultivars for resistance against root-knot nematodes. One tomato cultivar, Homerunking was proved to be resistant while eight cultivars such as Regendsummer, Regend, Sunmyung, Pinktop, Top3, Delice, Tasha and Lilyance were moderately resistant to the root-knot nematodes. Five cherry tomato cultivars (Tenten, Desert, Redstar, Veryking and Arigatto) showed moderate resistance and one cultivar (Redcherry) was resistant to root-knot nematodes. In eight rootstock tomato cultivars, two cultivars (Bukinghagae, Special) were resistant and five cultivars (B-blocking, Solution, Dongbanja and Greenpower) were moderate.

Effects of Heavy Metal Contamination from an Abandoned Mine on Tomato Growth and Root-knot Nematode Development

  • Park, Byeong-Yong;Lee, Jae-Kook;Ro, Hee-Myong;Kim, Young-Ho
    • The Plant Pathology Journal
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    • v.27 no.3
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    • pp.266-271
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    • 2011
  • Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.

Study on Integrated Control against Root-knot Nematode of Fruit Vegetables (Oriental Melon and Cucumber) in Vinyl House (시설과채류(오이, 참외)의 뿌리혹선충 종합방제에 관한 연구)

  • 박소득;박선도;권태영;최부술;이원식;최영연
    • Korean journal of applied entomology
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    • v.34 no.1
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    • pp.75-81
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    • 1995
  • To reduce crop damage from root-knot nematode, Meloidogyne spp. chemical, cultural, physical control methods were compared in commercial greenhouse for 3 years from 1992 to 1994. Timing of sol exchange for economic losses due to the nematodes is important: every 3 years for coarse sand (Masatto) and every 4 years for red-yellow soil. Control effects on Meloidogyne spp. in cucumber were 78.2% in Dazomet DP, 72.1% Carbo G+Soil reverse+submergence, and 66.3% in Carbo G+submergence. Pesticide effects were temporally different after treatment: 77.7~80.6% in 20 days and 33.7~49.5% in 60 days. Cropping system in oriental melon gave an excellent control effect of 81.1% at oriental melon/rice culture. All methods controled root-knot nematodes at the time of the treatment but the number of the nematodes increased at the end of the season. However, soil exchange was effective for 3 years. The most economic control practice is rotation with rice for every three years.

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A Review on the Performance Test of a High-Speed Planing Hull with 35 knot Speed by Appling the Streamlined Step of Hull Form (유선형 스텝 선형을 적용한 35 knot급 고속활주선의 성능평가에 대한 고찰)

  • Moon, Byung Young;Go, Ho Nam;Lee, Ki Yeol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.3
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    • pp.95-102
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    • 2018
  • As a recent technical approach, a high-speed planing hull was tried to realize a friction reducing system by simultaneously actuating the triple streamlined step hull form in association with optimum speed of 35 knot planing for fishing boat. In this approach, the streamlined step hull form with triple structure of type was attached under the bottom of high-speed planing hull, while a friction resistance is reduced in the process of running at the speed of 35 knot. In addition, this research was to make a performance test as to the manufactured product and acquire the purposed values and the development items. Actually, after manufacturing the desired prototype of high-speed planing hull, the significant items, fuel efficiency (second) and amount of fuel consumption (degree) including maximum speed (knot) were estimated for a performance test. And tensile strength (MPa) and bend strength (MPa) as to the completed prototype like a high speed planing hull were also acquired during the test.