• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.257-262
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• 2015

The visual cells in the retina of Iksookimia longicorpa (Pisces, Cobitidae) were investigated by light and scanning electron microscopes. The retina ($216.42{\pm}13.36{\mu}m$) has several layers, and the visual cell layer consists of unequal double cones and large rods. In a double cone, two members are unequal such that one cone is longer than the other (long element $26.42{\pm}1.7{\mu}m$, short element $16.82{\pm}1.1{\mu}m$). The cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. The visual cells observed have an outer segment (hematophilic), inner segment (eosinophilic). In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles (calyceal processes) of membrane discs surrounded by double membranes.

• The Journal of the Acoustical Society of Korea
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• v.35 no.4
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• pp.261-271
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• 2016

In the prediction of response of a pile in soil, numerical approaches such as a finite element method are generally applied due to complicate nonlinear behaviors of soils. However, the numerical methods based on the finite elements require heavy efforts in pile and soil modelling and also take long computing time. So their usage is limited especially in the early design stage in which principal dimensions and properties are not specified and tend to vary. On the contrary, theoretical approaches adopting linear approximations for soils are relatively simple and easy to model and take short computing time. Therefore, if they are validated to be reliable, they would be applicable in predicting responses of a pile in soil, particularly in early design stage. In case of wind turbines regarded in this study, it is required to assess their natural frequencies in early stages, and in this simulation the supporting pile inserted in soil could be replaced with a simplified elastic boundary condition at the bottom end of the wind turbine tower. To do this, analysis for a pile in soil is performed in this study to extract the spring constants at the top end of the pile. The pile in soil can be modelled as a beam on elastic spring by assuming that the soils deform within an elastic range. In this study, it is attempted to predict pile deformations and influence factors for lateral loads by means of the beam-on-spring model. As two example supporting structures for wind turbines, mono pile and suction pile models with different diameters are examined by evaluating their influence factors and validated by comparing them with those reported in literature. In addition, the deflection profiles along the depth and spring constants at the top end of the piles are compared to assess their supporting features.