• Title/Summary/Keyword: sweep net

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Multilevel acceleration of scattering-source iterations with application to electron transport

  • Drumm, Clif;Fan, Wesley
    • Nuclear Engineering and Technology
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    • v.49 no.6
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    • pp.1114-1124
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    • 2017
  • Acceleration/preconditioning strategies available in the SCEPTRE radiation transport code are described. A flexible transport synthetic acceleration (TSA) algorithm that uses a low-order discrete-ordinates ($S_N$) or spherical-harmonics ($P_N$) solve to accelerate convergence of a high-order $S_N$ source-iteration (SI) solve is described. Convergence of the low-order solves can be further accelerated by applying off-the-shelf incomplete-factorization or algebraic-multigrid methods. Also available is an algorithm that uses a generalized minimum residual (GMRES) iterative method rather than SI for convergence, using a parallel sweep-based solver to build up a Krylov subspace. TSA has been applied as a preconditioner to accelerate the convergence of the GMRES iterations. The methods are applied to several problems involving electron transport and problems with artificial cross sections with large scattering ratios. These methods were compared and evaluated by considering material discontinuities and scattering anisotropy. Observed accelerations obtained are highly problem dependent, but speedup factors around 10 have been observed in typical applications.

Application of a Membrane Desolvator to the Analysis of Organic Solvents in Inductively Coupled Plasma Atomic Emission Spectrometry

  • Lee, J. S.;Lim, H. B.
    • Bulletin of the Korean Chemical Society
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    • v.20 no.9
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    • pp.1040-1044
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    • 1999
  • A micro porous PTFE membrane desolvator (MMD) was built and evaluated for the on-line removal of organic solvents to facilitate the determination of trace metal contaminants in the solvents by ICP-AES. Three organic solvents, isopropyl alcohol (IPA), methanol, and dimethy sulfoxide (DMSO) were studied. The MMD reduced organic solvent concentration in the sample aerosol stream by 82% to 89%, as indicated by monitoring C(I) emission. Net signal intensity of Fe, Al, and Cu was increasing with higher organic solvent concentration, with the rate of increase being solvent dependent. The signal intensities for Mg and Pb followed the trend with the C(I) signal. Changing the sweep gas flow rate affected the optimum signal intensity. Wine samples were analyzed by the method of standard addition. The concentrations of B, Al, and Mg were determined with a relative precision of less than 2.3%.

Two New Records of Sac Spiders including a New Species (Araneae: Clubionidae) from Korea

  • Jang, Chang Moon;Bae, Yang Seop;Yoo, Jung Sun;Lee, Sue Yeon;Kim, Seung Tae
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.4
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    • pp.330-334
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    • 2021
  • The genus Clubiona Latreille, 1804 is the most diverse and largest one in the family Clubionidae Wagner, 1887. Twenty-nine species of the genus have been described in various ecosystems from Korea to date. Clubiona semicircularis Tang, Song and Zhu, 2005 which was formerly only known in China and Clubiona ansa n. sp. were collected with a sweep net on the foliage of the shrubs in mixed forests from mountains and agricultural landscape during a seasonal survey of the spider fauna in Korea. This study describes these two species with a diagnosis, measurements, and morphological illustrations. In addition, the female of C. semicircularis is described with a diagnosis for the first time from the present study.

Neriene bovista sp. nov., a new sheet-web spider (Araneae: Linyphiidae) from Korea

  • Lee, Sue Yeon;Yoo, Jung Sun;Kim, Seung Tae
    • Journal of Species Research
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    • v.11 no.2
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    • pp.94-97
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    • 2022
  • Linyphiidae Blackwall, 1859 is one of the most diverse and largest families within the order Araneae Clerck, 1757. Of the currently 60 valid species of the genus Neriene Blackwall, 1833 worldwide, 10 species are distributed in Korea. The males of the new sheet-web spider Neriene bovista sp. nov. were recently collected with a sweep net between the shrubs of mixed forests from the hilly valley with well conserved nature in Uljin-gun, Gyeongsangbuk-do (the middle east coast region) during a seasonal survey of the spider fauna in hilly terrains in 2017-2018. The present study describes a new sheet-web spider, Neriene bovista sp. nov. with a diagnosis, detailed description, morphological illustrations, and a distribution map from Korea. The new species has a characteristic mushroom-like tip of the terminal apophysis, the truncated tip of anterior projection, and the bifurcated lateral projection of the lamella compared to the congeners of the genus Neriene Blackwall, 1833.

Two new records of orb-weaving spiders with a new species (Araneae: Araneidae) from Korea

  • Lee, Sue Yeon;Yoo, Jung Sun;Kim, Seung Tae
    • Journal of Species Research
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    • v.10 no.4
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    • pp.387-391
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    • 2021
  • Araneidae Clerck, 1757 is one of the largest families within the order Araneae Clerck, 1757, comprising 3,065 species in 177 genera. To date, two species of the genus Mengora O. Pickard-Cambridge, 1889 and four species of the genus Araniella Chamberlin & Ivie, 1942 have been recorded in Korea. During a seasonal survey of the spider fauna in mountainous terrain conducted from 2018 to 2019, females of Mangora foliosa Zhu & Yin, 1998 and a male of Araniella robusta sp. nov. were collected with a sweep net between shrubs in mixed forests from Mt. Juwangsan National Park. In this paper, we provide a diagnosis of the new species and descriptions including measurements and morphological illustrations. The new species, Araniella robusta sp. nov., can be easily distinguished from other species in the genus Araniella Chamberlin & Ivie, 1942 by a branched conductor with two blunt tips and conjugation of the embolus tip and terminal apophysis.

A new crab spider(Araneae; Thomisidae) from Korea

  • Sue Yeon Lee;Jung Sun Yoo;Seung Tae Kim
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.523-525
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    • 2021
  • Two species of the genus Oxytate L. Koch, 1878 have been recorded in Korea to date. The spider fauna was surveyed in the mountainous terrain of Mt. Hallasan National Park in 2019. A female of Oxytate lobia sp. nov. was collected with a sweep net between shrubs in mixed forests during a seasonal spider survey and is described with measurements, morphological illustrations, and a diagnosis. The new species can be easily distinguished from similar species within the genus by the long copulatory duct conjugated with a spermatheca, a pair of triangular pits at the bottom, and no ditches.

Thanatus arcticus Thorell, 1872 (Araneae: Philodromidae) new to the Korean spider fauna

  • Sue Yeon Lee;Jung Sun Yoo;Chang Moon Jang;Seung Tae Kim
    • Journal of Species Research
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    • v.12 no.4
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    • pp.277-280
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    • 2023
  • Philodromidae Thorell, 1869 is one of the most diversified and largest families comprising 522 species in 29 genera within the order Araneae Clerck, 1757. The genus Thanatus C. L. Koch, 1837 comprise 99 species of the family and four species of the genus Thanatus (Philodromidae) have been recorded in Korea: T. coreanus Paik, 1979, T. miniaceus Simon, 1880, T. nipponicus Yaginuma, 1969, and T. vulgaris Simon, 1870. Two females of T. arcticus Thorell, 1872 were collected by sweep net between the shrubs in mountainous mixed forests from Mt. Chiaksan National Park, Wonju-si, Gangwon-do and Mt. Naejangsan National Park, Jangseong-gun, Jeollanam-do. The present study describes T. arcticus with measurements and taxonomic illustrations.

A collect system of marine floating garbages by towing to the surface (표층 예인 부상식 해양 부유폐기물 수거 시스템)

  • Jang, Duck-Jong;Na, Sun-Cheol;Choi, Myung-Soo
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.91-95
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    • 2007
  • It tries to develop a collect system for floating garbage flowed into the sea Based on the study on the characteristics of floating garbage in rainy season, it confirmed the structure and specification of each device and tested its performance on the sea It showed tint the collection device of this system could sweep more than 15 meters of sea area at a time when a ship moves with the efficiency of the spreading device. It means tint it is more efficient in collecting garbage than now in use garbage collecting ships. The water height of the net to which the garbage is finally input maintained more 50cm within the towing speed of 5kt. It indicates tint the garbage input performance is good The collect system of this research showed good performance collecting 200kg of garbage into the net for each test of collecting floating garbage.

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A SENSITIVITY ANALYSIS OF THE KEY PARAMETERS FOR THE PREDICTION OF THE PRESTRESS FORCE ON BONDED TENDONS

  • Jang, Jung-Bum;Lee, Hong-Pyo;Hwang, Kyeong-Min;Song, Young-Chul
    • Nuclear Engineering and Technology
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    • v.42 no.3
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    • pp.319-328
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    • 2010
  • Bonded tendons have been used in reactor buildings at some operating nuclear power plants in Korea. Assessing prestress force on these bonded tendons has become an important pending problem in efforts to assure continued operation beyond their design life. The System Identification (SI) technique was thus developed to improve upon the existing indirect assessment technique for bonded tendons. As a first step, this study analyzed the sensitivity of the key parameters to prestress force, and then determined the optimal parameters for the SI technique. A total of six scaled post-tensioned concrete beams with bonded tendons were manufactured. In order to investigate the correlation of the natural frequency and the displacement to prestress force, an impact test, a Single Input Multiple Output (SIMO) sine sweep test, and a bending test using an optical fiber sensor and compact displacement transducer were carried out. These tests found that both the natural frequency and the displacement show a good correlation with prestress force and that both parameters are available for the SI technique to predict prestress force. However, displacements by the optical fiber sensor and compact displacement transducer were shown to be more sensitive than the natural frequency to prestress force. Such displacements are more useful than the natural frequency as an input parameter for the SI technique.

The first record of the winter stonefly genus Mesyatsia Ricker & Ross, 1975 (Plecoptera: Taeniopterygidae) from Korea

  • Hwang, Jeong Mi;Hur, Jun Mi;Kang, Ji Hyoun;Bae, Yeon Jae;Muranyi, David
    • Journal of Species Research
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    • v.10 no.4
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    • pp.419-421
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    • 2021
  • The genus Mesyatsia Ricker & Ross, 1975 is a small genus of the family Taeniopterygidae with only six species worldwide. This genus is mainly distributed in Asia, but has never been reported in Korea. In this paper, we report Mesyatsia makartchenkoi Teslenko & Zhiltzova, 1992 for the first time from the Korean Peninsula. The specimens were collected from Odaesan National Park, Bangtaesan Natural Recreation Forest, and Gariwangsan Natural Recreation Forest in Gangwon-do, South Korea by mainly Malaise traps and a few by sweep net. Some pharate larvae and adults crawling on the snow were also collected by handpicking. This species is characterized by the following features: pterostigma with dark spots; abdominal sternum 9 with vesicle; abdominal tergum 10 medially divided into two; subgenital plate strongly elongated, scoop-shaped, upcurved with tongue-shaped apex; cercus blunt. We provide materials, diagnosis for newly recorded species, and distributions. Additionally, we include a provisional key to the genera of Taeniopterygidae from Korea based on males.