• 제목/요약/키워드: Continua

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Korean Listeners' Perception of English /i/, /I/, and /$\epsilon$/

  • Yun, Yung-Do
    • 음성과학
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    • 제12권1호
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    • pp.75-87
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    • 2005
  • In this study I investigate how native Korean listeners perceive English vowels /i/, /I/, and /$\epsilon$/. I extend Flege et al's (1997) study with synthesized /i/-/I/ and /I/-/$\epsilon$/ continua, and apply the results to Flege's (1995) Speech Learning Model (SLM). The statistical results show that native speakers of English rely more on spectral steps than on vowel duration when they identify the /i/-/I/ continuum, whereas native speakers of Korean rely more on vowel duration than on spectral steps when they identify the same continuum. In the case of the /I/-/$\epsilon$/ continuum, both groups rely on spectral steps when they identify the /$\epsilon$/, which supports the SLM; Koreans identified the /$\epsilon$/ categorically since Korean has the equivalent vowel. However, there was not statistical difference between Korean subjects with more English experience (KE) and those with less English experience in the identification of both continua. This contradicts the SLM, which posits that experienced L2 learners are better than inexperienced L2 learners in perception of L2 sounds. The exact nature of this should be further investigated in the SLM.

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Discrete crack analysis for concrete structures using the hybrid-type penalty method

  • Fujiwara, Yoshihiro;Takeuchi, Norio;Shiomi, Tadahiko;Kambayashi, Atsushi
    • Computers and Concrete
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    • 제16권4호
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    • pp.587-604
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    • 2015
  • The hybrid-type penalty method (HPM) is suitable for representing failure phenomena occurring during the transition from continua to discontinua in materials such as concrete. Initiation and propagation of dominant cracks and branching of cracks can easily be modeled as a discrete crack. The HPM represents a discrete crack by eliminating the penalty that represents the separation of the elements at the intersection boundary. This treatment is easy because no change in the degrees of freedom for the discrete crack is necessary. In addition, it is important to evaluate the correct deformation of the continua before the crack formation is initiated. To achieve this, we implemented a constitutive model of concrete for the HPM. In this paper, we explain the implemented constitutive model and describe the simulation of an anchor bolt pullout test using the HPM demonstrating its capability for evaluating progressive failure.

Forced vibration analysis of functionally graded sandwich deep beams

  • Akbas, Seref D.
    • Coupled systems mechanics
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    • 제8권3호
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    • pp.259-271
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    • 2019
  • This paper presents forced vibration analysis of sandwich deep beams made of functionally graded material (FGM) in face layers and a porous material in core layer. The FGM sandwich deep beam is subjected to a harmonic dynamic load. The FGM in the face layer is graded though the layer thickness. In order to get more realistic result for the deep beam problem, the plane solid continua is used in the modeling of The FGM sandwich deep beam. The equations of the problem are derived based the Hamilton procedure and solved by using the finite element method. The novelty in this paper is to investigate the dynamic responses of sandwich deep beams made of FGM and porous material by using the plane solid continua. In the numerical results, the effects of different material distributions, porosity coefficient, geometric and dynamic parameters on the dynamic responses of the FGM sandwich deep beam are investigated and discussed.

Echinostoma hortense and Heterophyid Metacercariae Encysted in Yellowfin Goby, Acanthogobius flavimanus, from Shinan-gun and Muan-gun (Jeollanam-do), Korea

  • Sohn, Woon-Mok;Na, Byoung-Kuk;Cho, Shin-Hyeong
    • Parasites, Hosts and Diseases
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    • 제47권3호
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    • pp.307-310
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    • 2009
  • Fishborne trematode (FBT) metacercariae were investigated in yellowfin goby, Acanthogobius flavimanus, collected from Shinan-gun and Muan-gun, Jeollanam-do (province), Korea. All collected fishes were examined using the artificial digestion method. In all of 15 gobies from Aphae-myeon in Shinan-gun, metacercariae of Stictodora spp. (334 metacercariae/fish), Heterophyes nocens (153/fish), and Heterophyopsis continua (20/fish) were detected. In 2 of 14 gobies from Jido-myeon in Shinan-gun, 8 Echinostoma hortense metacercariae in total were detected. In 15 gobies from Haeje-myeon in Muan-gun, the metacercariae of H. continua were found in 100%, Stictodora spp. in 86.7%, and H. nocens in 6.7% of fish examined. The average numbers of metacercariae per infected fish were 23.3 (H. continua), 416.0 (Stictodora spp.), and 2.0(H. nocens), respectively. The metacercariae of E. hortense found in gobies were elliptical, with 150 ${\times}$ 138 ${\mu}m$, in average size, and had 27 collar spines on the head crown. The above results suggest that yellowfin gobies from 2 localities may be the potential infection sources of FBT. Moreover, it is proved for the first time that the yellowfin goby, A. flavimanus, acts as a second intermediate host for E. hortense.

Infection Status of Estuarine Fish and Oysters with Intestinal Fluke Metacercariae in Muan-gun, Jeollanam-do, Korea

  • Cho, Shin-Hyeong;Kim, In-Sang;Hwang, Eun-Jung;Kim, Tong-Soo;Na, Byoung-Kuk;Sohn, Woon-Mok
    • Parasites, Hosts and Diseases
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    • 제50권3호
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    • pp.215-220
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    • 2012
  • The source of human infection with intestinal flukes was surveyed in estuarine fishes, including the dotted gizzard shad, common sea bass, common blackish goby, redlip mullet, black sea bream, and oyster collected from Muan-gun, Jeollanam-do, Korea during August and September 2007. Collected fishes and oysters were artificially digested in pepsin-HCl solution and examined under a stereomicroscope. In 36 shads (Konosirus punctatus) and 20 basses (Lateolabrax japonicus) examined, Heterophyopsis continua metacercariae were found in 58.3% and 100%, and their average numbers were 12.0 and 6.3 per infected fish, respectively. In 34 gobies (Acanthogobius flavimanus) examined, metacercariae of H. continua were detected in 79.4%, Stictodora lari in 97.1%, and Acanthotrema felis in 92.1%, and their average numbers were 45.8, 189.3, and 235.3 per infected fish, respectively. In 37 redlip mullets (Chelon haematocheilus), Heterophyes nocens metacercariae were found in 56.8%, Pygidiopsis summa in 94.6%, and Stictodora fuscata in 45.9%, and the average metacercarial densities were 17.4, 31.3, and 35.1 per infected fish, respectively. In 30 black sea breams (Acanthopagrus schlegeli) and 45 oysters (Crassostrea gigas) examined, no metacercariae were detected. From the above results, it has been confirmed that the dotted gizzard shad, common sea bass, common blackish goby, and redlip mullet from Muan-gun, Jeollanam-do, Korea are infected with the metacercariae of heterophyid flukes.

Foodborne Trematode Metacercariae in Fish from Northern Vietnam and Their Adults Recovered from Experimental Hamsters

  • Chai, Jong-Yil;Nguyen, Van De;Sohn, Woon-Mok
    • Parasites, Hosts and Diseases
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    • 제50권4호
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    • pp.317-325
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    • 2012
  • The prevalence of foodborne trematode (FBT) metacercariae was investigated in fish from 2 localities of northern Vietnam in 2004-2005. Freshwater fish (9 species) were collected from local markets in Hanoi City (n=76) and Nam Dinh Province (n=79), and were examined for FBT metacercariae using the artificial digestion technique. Adult flukes were obtained from hamsters experimentally infected with the metacercariae at day 8 post-infection. Three (Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium) and 6 (Haplorchis taichui, H. pumilio, C. formosanus, P. varium, Stellantchasmus falcatus, and Heterophyopsis continua) species of FBT metacercariae were detected in the 2 regions, respectively. Overall, among the positive fish species, H. pumilio metacercariae were detected in 104 (80.0%) of 130 fish examined (metacercarial density per infected fish; 64.2). C. formosanus metacercariae were found in 37 (40.2%) of 92 fish (metacercarial density; 14.7). P. varium metacercariae were detected in 19 (63.3%) of 30 fish (Anabas testudineus and Mugil cephalus) (metacercarial density; 247.7). S. falcatus metacercariae were found in all 10 M. cephalus examined (metacercarial density; 84.4). H. continua metacercariae (2 in number) were detected in 1 fish of Coilia lindmani. Morphologic characteristics of the FBT metacercariae and their experimentally obtained adults were described. The results have demonstrated that various FBT species are prevalent in northen parts of Vietnam.