• 제목/요약/키워드: Speciation

검색결과 324건 처리시간 0.041초

Species Adaptation Evolutionary Algorithm for Solving the Optimization Problems

  • Lee, Dong-Wook;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권2호
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    • pp.233-238
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    • 2003
  • Living creatures maintain their variety through speciation, which helps them to have more fitness for an environment. So evolutionary algorithm based on biological evolution must maintain variety in order to adapt to its environment. In this paper, we utilize the concept of speciation. Each individual of population creates their offsprings using mutation, and next generation consists of them. Each individual explores search space determined by mutation. Useful search space is extended by differentiation, then population explorers whole search space very effectively. If evolvable hardware evolves through mutation, it is useful way to explorer search space because of less varying inner structure. We verify the effectiveness of the proposed method by applying it to two optimization problems.

단방조충(單房條蟲)의 역학적연구(疫學的硏究) : 감염실태조사(感染實態調査)와 아종(亞種)의 결정(決定) (Epizootiological study of Echinococcus granulosus(Batsch, 1786) Rudolphi, 1805. in Jeju-do. 1. Incidences of bovine hydatid cyst and its speciation)

  • 장두환;오문유
    • 대한수의학회지
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    • 제14권1호
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    • pp.73-76
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    • 1974
  • A basic survey of Echinococcus infection in cattle slaughtered at seogipo abattoir, Jeju Island was carried out. The incidence of hydatid cyst was 0.4% in the native cattle, that is 4 heads out of 993 heads of the slaughtered cattle. The hydatid cysts with or without scolices were found in the liver and lung, and the speciation of them was determined as Echinococcus granulosus granulosus with the morphological and biological characters. The infection rates of bovine echinococcosis were as high as 6.8% to 27.5% from 1936 to 1940 in Jeju cattle, but it has been found greatly decreased to 0.4% in this survey. The main reason of decrease in the incidence was cleared with the fact that wild dogs were abundant at that times.

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Gallium(III) Ion Hydrolysis under Physiological Conditions

  • Hacht, Brahim
    • Bulletin of the Korean Chemical Society
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    • 제29권2호
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    • pp.372-376
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    • 2008
  • The hydrolysis of gallium(III) has been studied using potentiometric techniques under physiological conditions of temperature 37 C and ionic strength 0.15 moldm-3 NaCl and at different metal ion concentrations. Changes in pH were monitored with a glass electrode calibrated daily in hydrogen ions concentrations. The titration data within the pH range of 2.5-9.99 were analyzed to determine stability constants of hydroxide species using the SUPERQUAD program. Several different species were considered during the calculation procedure and the following hydroxides have been characterized: Ga(OH)3, Ga(OH)4- Ga3(OH)112-, Ga4(OH)11+ and Ga6(OH)153+. Speciation calculations based on the determined constants were then used to simulate the species distribution.

Tritium and 14C in the Environment and Nuclear Facilities: Sources and Analytical Methods

  • Hou, Xiaolin
    • 방사성폐기물학회지
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    • 제16권1호
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    • pp.11-39
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    • 2018
  • Tritium and $^{14}C$ are two most important radionuclides released from nuclear facilities to the environment, and $^{14}C$ contributes dominant radiation dose to the population around nuclear power plants. This paper presents an overview of the production, pathway, species and levels of tritium and $^{14}C$ in nuclear facilities, mainly nuclear power plants. The methods for sampling and collection of different species of tritium and $^{14}C$ in the discharge gas from the stack in the nuclear facilities, atmosphere of the nuclear facilities and environment are presented, and the features of different methods are reviewed. The on-line monitoring methods of gaseous tritium and $^{14}C$ in air and laboratory measurement methods for sensitive determination of tritium and $^{14}C$ in collected samples, water and environmental solid samples are also discussed in detailed. Meanwhile, the challenges in the determination and speciation analysis of tritium and $^{14}C$ are also highlighted.

The Investigation of a Novel Indicator System for Trace Determination and Speciation of Selenium in Natural Water Samples by Kinetic Spectrophotometric Detection

  • Gurkan, Ramazan;Ulusoy, Halil Ibrahim
    • Bulletin of the Korean Chemical Society
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    • 제31권7호
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    • pp.1907-1914
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    • 2010
  • A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI) and total inorganic selenium in water based on the catalytic effect of Se(IV) on the reduction of bromate by p-nitrophenylhydrazine at pH 3.0. The generated bromine, $Br_2$ or $Cl_2$ plus $Br_2$ in 0.1 M NaCl (or NaBr) environment efficiently decolorized Calmagite and the reaction was monitored spectrophotometrically at 523 nm as a function of time. In this indicator reaction, bromide acted as an activator for the catalysis of selenium (IV) and a reducing agent for selenium (VI) at pH 3.0, which allowed the determination of total selenium. The fixed time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the calibration graph are linear in the range 1 - 35 ${\mu}gL^{-1}$ of Se(IV) for the fixed time method at $25^{\circ}C$. The detection limit based on statistical $3S_{blank}$/m-criterion was 0.215 ${\mu}gL^{-1}$ for the fixed time method (7 min). All of the variables that affect the sensitivity at 523 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se (IV) determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The RSDs for ten replicate measurements of 5, 15 and 25 ${\mu}gL^{-1}$ of Se(IV) and Se(VI) was changed between 2.1 - 4.85%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. Se(IV), Se(VI) and total inorganic selenium in environmental water samples have been successfully determined by this method after selective reduction of Se(VI) to Se(IV).

어류중 비소의 종분화 분석을 위한 초음파 추출법과 마이크로파 추출법의 비교 (A Comparison of Sonication and Microwave-assisted Extraction Method for Speciation of Arsenic in Fish Tissue, DORM-2)

  • 윤철호;박용철;홍종기
    • 분석과학
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    • 제16권2호
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    • pp.134-142
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    • 2003
  • LC-ICP-MS를 이용한 어류중 비소의 종분화 분석을 위해 microwave-assisted extraction과 sonication extraction 방법을 비교하였다. Ultrasonic nebulizer와 cross flow nebulizer를 사용한 비소종들의 검출한계는 유사한 결과를 보였다. 분석된 비소 종들은 arsenobetaine (AsB), arsenite [As(III)], dimethylarsine acid (DMA), monomethylarsonic acid (MMA), arsenate [As(v)] 와 phenylarsonic acid (PAA) 이다. 두 가지 방법은 NRCC (National Research Council of Canada)의 표준물질인 DORM-2를 50% 메탄올로 추출하였다. arsenobetaine의 경우, 두 방법 모두 5% 이하의 상대표준편차와 82% 이상의 추출효율을 보였다. Arsenobetaine은 microwave assisted extraction 방법에서 $14.18{\pm}0.42mg\;kg^{-1}$을 보였고 sonication extraction 방법에서는 $13.54 {\pm}0.84mg\;kg^{-1}$을 보였다. dimethylarsine acid (DMA)의 경우 각각 $0.45{\pm}0.06mg\;kg^{-1}$$0.44{\pm}0.06mg\;kg^{-1}$를 보였다.