• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.55-64
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• 2018

Fish assemblages in a sandy shore and an eelgrass bed were compared based on monthly samples in the southern coastal water of Korea. Samples were collected by a beam trawl in the sandy shore and a surf net in the eelgrass from March to February 2012. The common fish species were Syngnathus schlegeli, Pseudoblennius cottoides, Pholis nebulosa, Favonigobius gymnauchen, Gymnogobius heptacanthus, Pseudopleuronectes yokohamae, Takifugu niphobles. Among them S. schlegeli, Urocampus nanus, P. cottoides, P. nebulosa, T. niphobles were high abundance in the eelgrass bed than in the sandy shore, whereas Acanthogobius flavimanus, Acentrogobius pflaumi, F. gymnauchen, G. heptacanthus, P. yokohamae were high in the sandy shore. Aulichthys japonicus, Hippocampus coronatus, Sebastes inermis, Lateolabrax japonicus, Siganus fuscescens were found in the eelgrass bed, and Thryssa hamiltoni, Mugil cephalus, Inimicus japonicus, Platycephalus indicus, Hexagrammos otakii, Furcina ishikawae, Liparis tanakae, Repomucenus curvicornis, and Eutaeniichthys gilli were observed in the sandy shore. Species composition and abundance varied seasonally in two habitats; The number of species and abundance was high in August and September, while biomass was the highest in April and September. Fish numbers as well as biomass were lowest in February. Number of individuals and biomass of fish in the eelgrass bed were significantly higher than those of in the sandy shore. Some fish preferred to live in the eelgrass were collected in the sandy shore, while fish preferred to live in the sandy shore were rarely collected in the eelgrass.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.121-129
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• 1999

When continuous media are transmitted over the communication networks, asynchrony which can not maintain temporal relationships among packets may occur due to a random transit delay. There exist two types of synchronization schemes ; for guaranteed or non-guaranteed resource networks. The former which applies a resource reservation technique maintains delay characteristics, however, the latter supply a best-effort service. In this paper, I propose a intra-media synchronization scheme to transmit continuous media on general networks not guaranteeing a bounded delay tome. The scheme controls transmission times of the packets by estimating next delay time with the delay distribution. So, the arriving packets may be maintained within a limited delay boundary, and playout will be performed after buffering to smoothen small delay variations. The continually increasing delay due to network overload causes buffer underflow at the receiver. To solve it, the transmitter is required to speed up instantaneously. Too much increase of transmission-rate may cause network congestion. At that time, the transmitter drops the current packet when informed excessive delay from the receiver.