• Animal Systematics, Evolution and Diversity
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• v.17 no.1
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• pp.13-19
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• 2001

Hydra and hydromedusa specimens were collected from the Jisanchon Stream in Kyonggi-do (Pyongtaek-shi) and the coasts of Geojedo Island (Jangmok-ri), Korea during the period July 1999-June 2000. They were identified into Hydra magnipapillata Ito, 1947 (Hydridae, Athecatae) and Phialidium folleatum (McCrady, 1857) (Campanulariidae, Leptomedusae) respectively. H. magnipapillata is blackish or light brown color, its cylinder-shaped trunk reaches to 20 ㎜ long and 0.5-0.6 ㎜ wide in fully extended, and has generally 5-6 highly delicate long tentacles. P. folleatum is a small marine hydromedusa, below 5 ㎜ wide and has a minute statocyst between successive tentacles.

• BMB Reports
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• v.40 no.2
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• pp.286-289
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• 2007

Despite considerable interest in the biologic processes of regeneration and stem cell activation, little is known about the genes involved in these transformative events. In a Hydra littoralis model of regeneration, we employed a rapid shotgun suppression subtractive hybridization strategy to identify genes that are uniquely expressed in regenerating tissue. With an adaptor-PCR based technique, 16 candidate transcripts were identified, 15 were confirmed unique to mRNA isolated from hydra undergoing regeneration. Of these, 6 were undescribed in GenBank and allied expressed sequence tag (EST) databases (GenBank + EMBL + DDBJ + PDB and the Hydra EST database). BLAST analysis of these sequences identified remarkably similar sequences in anonymous ESTs found in a wide variety of animal species.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.4 no.1
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• pp.11-15
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• 1986

In the new futre, computer system designers are expeted to bring more computer power to more people than is currently feasible. At the same time. it is reasonable for the computer system desigers to expect the computer architects to prodce hardware structures incorporating system algorithms of greated complexity so that more of the general instructions go to serving the users. In the past, the architect has delivered more computing to the user by constructing bigger and faster central processors, possibly connecting two or three CPUs together This approach has its limitations, in cost, complexity and reliability. In this paper, we first briefly discuss the hardware environment on which Hydra was implemented, then discuss the philosophy on which the system is based, and finally exhibit the protection mechanism.

• Journal of The Korean Astronomical Society
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• v.33 no.2
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• pp.75-80
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• 2000

In order to identify the candidates of emission-line galaxies inside the southern Hydra Void, photo-graphic objective-prism observations with the UK Schmidt Telescope were carried out using the Tech-Pan films for five fields. All observed prism plates were scanned with the APM Facility and the scanned data was processed to determine the APM plate parameters and to draw spectra. For all galaxy spectra, the emission features, the distance between emission features of H$\beta$4861, [OIII]${\lambda}{\lambda}$ 4959, 5007 and the overlapping by nearby objects were investigated by eyeballing. A total of 7 candidates of emission-line galaxies inside the Hydra Void were identified.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.61.1-61.1
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• 2020

We examine the HI gas kinematics and distribution of galaxy pairs in group or cluster environment from high-resolution Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot observations. We use 22 well-resolved galaxies in the Hydra cluster of which 4 galaxies are visually identified as pairs and others are isolated ones. We perform profile decomposition of HI velocity profiles of the galaxies using a new tool, BAYGAUD which enables us to separate a line-of-sight velocity profile into an optimal number of Gaussian components based on Bayesian MCMC techniques. All the HI velocity profiles of the galaxies are decomposed into kinematically cold or warm gas components with their velocity dispersion, 4~8 km/s or > 8 km/s, respectively. We derive the mass fraction of the kinematically cold gas with respect to the total HI gas mass, f = log10(M_cold / M_HI), of the galaxies and correlate them with their dynamical mass. The cold gas reservoir of the paired galaxies in the Hydra cluster is found to be relatively higher than that of the isolated ones which show a negative correlation with the dynamical mass in general.

• Water for future
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• v.54 no.8
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• pp.56-60
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• 2021

• Publications of The Korean Astronomical Society
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• v.7 no.1
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• pp.39-50
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• 1992

A velocity inhomogeneity, which is the regional preponderence of either radial or tangential orbits, is searched with the new technique proposed by Kim (1992) for Coma, Hydra I, and Abell 2256 cluster of galaxies. Conspicuous inhomogeneities are found in the Coma and A2256 which X-ray isophotes are indicative for their underlying potentials being ellipitcal in shape, Even in their central regions, zones that are dominated by radial orbits are clearly distinguishable from that of the tangential orbits, and defining the cluster 'equator' as the direction of maximum elongation of the X-ray isophotes, radial orbits dominate along this direction whereas tangential orbits dominate the 'polar' zones. Merger events that are evidenced in X-ray observations occur in the equatorial zones of Coma and A2256, suggesting preponderence of radial orbits in the zones, which is in good agreement with their velocity structures. On the other hand, the inhomogeneity in Hydra I turns out to be insignificant in the central regions and this is just what is expected from a cluster whose X-ray isophotes is nearly circular. The velocity distribution in regions further out, however, shows significant inhomogeneity and this seems to support the previous results that this cluster is likely to have substructures and velocity anisotropy.

• Defense and Technology
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• no.2 s.96
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• pp.15-28
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• 1987

• The Bulletin of The Korean Astronomical Society
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• v.21
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• pp.13.1-13.1
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• 1996

• Defense and Technology
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• no.1 s.95
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• pp.30-44
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• 1987