• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.536-542
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• 1984

Fish eggs and larvae in the western waters of Korea are surveyed during the periods from February to August in 1982. Six species of eggs and forty-two species of larvae are occurred in the survey area. The dominant species occurred during the study periods are Ammodytes personatus, Enedrias sp., Engraulis japonica, Callionymus sp., Gobiidae, etc. Major spawning month and ground of each species are estimated from the data, i.e., occurrence month and abundance of eggs and larvae by survey month and area, as well as the optimum water temperature and salinity for spawning.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.438-446
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• 2010

For language information processing that includes both Hangul and Hanja, an electronic dictionary supporting Hangul and Hanja simultaneously is necessary. This paper examined statistical information on Hanja entries of Korean Unabridged Dictionary such as the number of entries that include Hanja based on the KSC-5601 character set, the frequency of the pronunciation and meaning of each character of Hanja included in the entries, the frequency per part of speech of Hanja in entries and the average number of Hanja characters per entry. At least one or more of Hanja characters appear in 303,951 entries out of 440,594, accounting for 68.99% of the total. 858,595 characters of Hanja are included in the 440,594 entries, which is 1.95 Hanja characters per entry. As the average syllable length of the entries is 3.56 and the average count of the Hanja characters per entry is 1.96, it can be said that 54.7% of all the characters of the entries are in Hanja. Among 4,888 Hanja character codes, 4,660 are used once or more, whereas 228 Hanja codes never appear in any entry. There were 5 characters which appear more than 4,000 times. A total of 858,595 Hanja characters used in all the entries correspond to 471 Hangeul codes.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.162-175
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• 2000

The present study was carried out to clarify the distribution of rotifera with salinity variation during the period from February 1998 to July 1999. Rotifera consists of 27 genera and 88 species, from the maximum occurrence of 39 species in November, 1998 to the minimum of 21 species March, 1998. With 32 dominant species, Keratella cochlearis cochlearis, K. cochlearis f. tecta, Ascomorpha saltans saltans and Asplanchna (s. str.) priodonta priodonta occurred predominantly. Distribution of Rotifera related to salinity showed that 36 species occurred in the freshwater zone, 3 species in the mixo-oligohaline zone ($0.5{\sim}5.0%_o$) and mixo-mesohaline zone ($5.1{\sim}28.0%_o$) respectively, on the other hand 2 species (Asplanhna (s. str.) priodonta priodonta, Synchaeta oblonga) in all zones. Average abundance by salinity ranged from $1,273\;ind./m^3$ ($25.0{\sim}28.0%_o$ to $16,259\;ind./m^3$ ($15.1{\sim}20.0%_o$. The percentage composition calculated effect by stepwise multiple regression of the pearson correlation coefficient value of environmental factors and Rotifera abundance (station $1{\sim}4$) revealed that it was 74.32% in BOD, 72.15% in COD, 69.77% in conductivity, 65.87% in $Cl^-$ and 58.27% in chlorophyll a. Also, (Station $5{\sim}12$) revealed 9.11% in $Cl^-$, 7.67% in TP and 6.20% in chlorophyll a.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.24-35
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• 1991

Fish larvae were collected monthly from coastal water around Hamduck, northern part of Cheju Island from April 1989 to March 1990. During the study period, a total of sixty four species, representing 35 genera and 27 families, were observed, of these 4 species appeared to be major groups which comprised about 66% of total fish larvae abundance, including Ammodytes personatus (February-March), Scomber japonicus(September-March), Enneapterygius etheostomus(June-September), and Engraulis japonica(August-November). Seasonally, the maximun numbers of species and individuals appeared in summer and in spring, and in summer, respectively, while the minima numbers of species and individuals appeared in winter. Inshore species were composed of 44 species(62.9%) and 557 individuals(70.4%), which were much higher both in the species numbers and individuals than those of offshore species.

• Journal of KIISE
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• v.44 no.5
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• pp.522-536
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• 2017

Keyword extraction can be utilized in text mining of massive documents for efficient extraction of subject or related words from the document. In this study, we proposed a hierarchical graph model based on the co-occurrence relationship, the intrinsic dependency relationship between words, and common sub-word in a single document. In addition, the enhanced TextRank algorithm that can reflect the influences of outgoing edges as well as those of incoming edges is proposed. Subsequently a novel keyword extraction scheme using the proposed hierarchical graph model and the enhanced TextRank algorithm is proposed to extract representative keywords from a single document. In the experiments, various evaluation methods were applied to the various subject documents in order to verify the accuracy and adaptability of the proposed scheme. As the results, the proposed scheme showed better performance than the previous schemes.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.118-129
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• 2002

Zooplankton was sampled vertically with a Norpac net from Gamag Bay in April, July, September and December, 2001. Copepods were predominant in April and December, and cladocerans in July and Noctituca scintillans in September, respectively. There are high spatio-temporal fluctuations in the abundance of zooplankton with a range of 22-17,197 indiv.$m^3$. In the copepod community, neritic species, Eurytemora pacifica, Acartia omorii, Centropages abdominalis and Calanus sinicus were predominant in April ; Labidocera rotunda and A. erythraea in July; A. erythraea and Paracalanus parvus s. 1. in September; A. omorii and E. pacifica in December. However, oceanic species Eucalanus sp. and Neocalanus sp. were abundant in September. It indicates that although Gamag Bay is semi-closed, the distribution pattern of zooplankton is seasonally strongly affected by oceanic waters in addition to neritic ones.

• Korean Journal of Ichthyology
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• v.17 no.2
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• pp.131-141
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• 2005

The ichthyofauna and structure of the fish community of Hapcheon Lake on the Hwang River were surveyed at six localities from May 2004 to Feb. 2005. There were 36 species belonging to 31 genera and 12 families in the Hapcheon Lake system. Of these, 24 species (66.7%) were cyprinids; cobitids and centropomids were next with 2 species (5.6%) each. The dominant species in the Hapcheon Lake system was Hemiculter eigenmanni (relative abundance 28.4%), the subdominant species Hemibarbus labeo (24.1%). Ten species (28.3%) of the 36 were Korean endemic species. Among the endemic species, H. eigenmanni and Squalidus chankaensis tsuchigae were abundant at each locality except site 6, but the eight other species were rare. In biomass, H. labeo comprised about 36.5% of the total weight, H. eigenmanni 22.3%, Cyprinus carpio 7.5%, Hypomesus nipponensis 6.9%, Culter brevicauda 3.7% and Lepomis macrochirus 3.6%. Average dominance, diversity, and evenness index of the fish community collected from six localities in the Hapcheon Lake system were 0.21, 0.85, and 0.67, respectively.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.60-69
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• 2007

Understanding the behavior of gas phase VOCs (volatile organic compounds) in unsaturated soils is of a great environmental importance for public health concerns. Moment analysis for the breakthrough curves (BTCs) during transport of chemicals in porous media was known to be a useful tool to evaluate the velocity, spreadness, and the skewness of the plume of the chemicals. In this study, the temporal moments of the BTCs of a group of VOCs were analyzed for the gaseous transport in an unsaturated soil. BTCs were measured using lab-scale column experiments for four different VOCs at the water saturation range of 0.04-0.46, and for eleven VOCs at a water saturation of 0.21. The central second and third moments of the VOCs were compared with the water saturation and the first moment. It was found that both central second and third moments increased with the first moment. The central third moment was, however, found to be more sensitive to the first moment.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.132-141
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• 2007

A total of 27 fish species were collected by a gill net in Masan Bay. The dominant fish species were Konosirus punctatus, Mugil cephalus, Engraulis japonicus, Psenopsis anomala, Lateolabrax japonicus, Leiognathus nuchalis, Chelon affinis, Trachurus japonicus, and these accounted for 87.6% of the total numbers. The numerically dominant fish species made up 95.4% of biomass. These were primarily juvenile species or early larger species. Temporal variation in both species composition and abundance was large: the peak number of fishes occurred in March 2005 and July 2005, whilst biomass of fishes was the highest in September 2005 and November 2005. Fish numbers as well as biomass was lowest in November 2005. Temporal changes in the abundance of fishes corresponded with temperature. A gill net can be used as an alternative fishing gear to collect pelagic fishes commercially, although a gill net has a strong selectivity for the target fish species or for size.

• Journal of Wetlands Research
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• v.4 no.1
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• pp.1-19
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• 2002

This study was carried out to provide basic data for biodiversity about phytoplankton at crater of Cheju parasite volcano from March to November 2000. In the study area, we identified 6 class 12 order 23 family 44 genus 87 species 13 variety 2 forma, Which were totally 102 taxa. Those were composed of 40 taxa(39.2%) of Chlorophyceae, 34 taxa(33.3%) of Bacillariophyceae, 14 taxa(l3.7%) of Canophyceae, 9 taxa(8.8%) of Euglenophyceae, 3 taxa(3.0%) of Dinophyceae, 2 taxa(2.0%) of Chrysophyceae, respectably. Monthly appearance of phytoplankton were 74 taxa on March, 46 taxa on May, 21 taxa on August, 22 taxa on November. Biodiversity of phytoplankton by station was 54 taxa in Moolchat, 22 taxa in Moolyoungari, 26 taxa in Mooljangauri, 12 taxa in Dongsuack, 6 taxa in Asungseang, 27 taxa in Samiaorum, respectably.