• Journal of Fisheries and Marine Sciences Education
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• v.26 no.2
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• pp.421-429
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• 2014

We investigated the feeding ecology of juvenile chum salmon (Oncorhynchus keta) during the critical early life stage prey selectivity of juvenile chum salmon during early marine migration in Korean waters at spring 2011. Salmon juveniles and zooplanktons were collected to draw with $20m{\times}5m$ gill net and $300{\mu}m$ mesh zooplankton net at each station on 11th-13th April n 2011. Collected zooplanktons were classified to 5 Phylum, 6 Class, 9 Order 17 Species in this study. Almost 76.4-100% species were classified to Phylum Arthropoda, dominant species was a species out of Hyperia galba of Order Amphipoda, Acartia spp and Paracalanus parvus of Order Calanoida. Collected salmon juveniles were grew up to average 4.7-5.4 cm fork length and average 1.0-1.5 g wet weight in whole station. Fish stomach content (mg/salmon) was heaver to 97.4, 82.4 and 63.2 mg wet weight/salmon in ST 2, 3, 4 than 20.4, 18.9 mg/salmon of ST 1, 5, because there are fish (sand eel, Hypoptychus dybowskii) and Krill (Euphausia) as prey in salmon stomach in ST 2, 3, 4. And ST 2, 3, 4 and 5 were dominated by Amphipoda as Hyperia galba, Themisto japonica and Gammarus sp., but ST 1 was dominated by copepod, because of absence of Amphipoda in the station. Therefore small Amphipoda as Hyperia galba was good prey for just released salmon juvenile in nature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.665-672
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• 1998

Feeding habits of Conger myiaster collected from the eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. C. myiaster was a carnivore which consumed mainly fishes, shrimps and crabs. Its diets included small quantities of amphipods, gastropods, cephalopods, polychaetes, mysids, cumaceans and isopods. It showed ontogenetic changes in feeding habits. Small indinviduals preyed on shrimps, fishes, crabs, and gammarid amphipods in nearly equal proportions. While the portion of the stomach contents attributable to shrimps and gammarid amphipods decreased with increasing fish size, consumption of fishes increased progressively. C. myiaster showed very constant prey selection regardless of prey availability-Especially fishes were heavily selected by this species throughout the year, although availability of fishes was lower than any other prey organisms in the eelgrass bed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.339-344
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• 2011

We investigated the effects of enrichment with oil or bacteria on the fatty acid composition of rotifers and Artemia as live prey. One enrichment(oil source) was mainly composed of squid Todarodes pacificus liver oil; the other(photosynthetic-bacterial source) was primarily made up of Schizochytrium sp. The enrichments were intended to enhance the nutritional value of the live prey, such as their EPA, DHA and n-3 HUFA contents. The lipid content as EPA and DHA of rotifers was higher when enriched with the oil source rather than the photosynthetic-bacterial source. The DHA content of Artemia nauplii after enrichment differed significantly, depending on the type of enrichment used(P<0.05). When the Artemia nauplii were enriched with the oil source, the DHA content was increased to 16.8%, whereas it increased only to 1.1% when enriched with the photosynthetic-bacterial source. These results indicate that selection of the enrichment is important for Artemia nauplii but not for rotifers.

• Korean Journal of Ichthyology
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• v.13 no.4
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• pp.230-236
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• 2001

Feeding habits of Gobiobotia brevibarba were investigated at Hongcheon River of Bangokri, Seomyon, Hongcheongun, Kangwondo from January to December, 2000. G. brevibarba was a carnivore and consumed mainly Ephemeroptera, Tricoptera and Diptera. Small quantities of Plecoptera and Coleoptera were included as a minor food items. The species showed ontogenetic changes in feeding habits. Individuals of small size (21~50 mm SL) fed mainly on small prey organisms such as Diptera and Ephemeroptera. However, larger Tricoptera were heavily selected with increasing fish size. The relative proportion of these food items changed with season. The prey selection indices for Ephemeroptera were positively selected in spring, summer and autumn, and negatively selected in winter, Diptera were positively selected in March, October and November.

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.72-79
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• 1999

Objectives. The purpose of this study was to evaluate the quality of abstracts of original articles. Methods. This subjects selected total 63 abstracts of the original articles of the Korean Journal of Preventive Medicine in 1997. The quality of abstracts was measured against a checklist of evaluation criteria, which were divided into eight categories and the numbers of inappropriate words (including grammar) according to criterionbased survey. A score for each abstract was obtained by dividing the number of criteria presented by the number applicable. The overall mean score was also determined. Results. The overall mean score of abstract quality was 0.55 out of 1. Of the abstracts subject selection 83% didn't include specific technical descriptors. Of those that gave conclusions 92% didn't address study limitations and 78% made no recommendations for future study. The overall mean number of inappropriate usage of words (including grammar) per abstract was 14.1. The overall mean number of English words was 283. In the multiple regression analyses, the research career of the first author and the number of English words to the number of inappropriate usage of words were statistically significant. Also, in the secondary regression model, the number of English words to the quality score of abstract was only statistically significant. Conclusions. Most of the abstracts provided some information pertaining to each evaluation criterion. However, they did not provide sufficient details to enhance the reader's understanding of the article. On the basis of the study the abstracts need improvement in its description of the reported subject selection, statements of limitations and recommendations, etc. The Korean Society for Preventive Medicine will recommend a proposal for more informative abstracts in Korean J Prey Med and will take into consideration the introduction of foreign review of abstracts. Future studies should address these issues and compare the quality of abstracts between different journals and their time of publication.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.193-204
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• 2014

The distribution of animals is affected by habitat selection, and habitat type and prey resource are important factors affecting their survival. This study was conducted to investigate the distribution pattern of the Red-tongue viper snake (Gloydius ussuriensis) with respect to altitude, habitat type and distribution of potential prey resource in Cheon-ma mountain, Korea. The study area of Cheon-ma mountain was separated into three altitude categories (low, middle, and high altitude) and the habitat types were categorized according to presence or absence of aquatic ecosystem and the preferred habitat in relation to altitude was determined. The distribution pattern of Red-tongue viper snakes was significantly different according to altitude and habitat type: they were mainly distributed at low altitude and in the water valleys. The distribution pattern of the Red-tongue viper snake correlated with that of amphibians. The analyses of microhabitat use of the Red-tongue viper snake and amphibians showed that their microhabitat types were not different significantly in water valleys. In conclusion, Red-tongue viper snakes were mainly distributed in the water valleys at low altitude and this is because amphibians are important as potential prey of the Red-tongue viper snake in Cheon-ma mountain.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.2 no.1
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• pp.95-110
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• 1998

Evolutionary Algorithms (EAs) are population-based optimization methods based on the principle of Darwinian natural selection. The representative methodology in EAs is genetic algorithm (GA) proposed by J. H. Holland, and the theoretical foundations of GA are the Schema Theorem and the Building Block Hypothesis. In the meaning of these foundational concepts, simple genetic algorithm (SGA) allocate more trials to the schemata whose average fitness remains above average. Although SGA does well in many applications as an optimization method, still it does not guarantee the convergence of a global optimum in GA-hard problems and deceptive problems. Therefore as an alternative scheme, there is a growing interest in a co-evolutionary system, where two populations constantly interact and co-evolve in contrast with traditional single population evolutionary algorithm. In this paper we show why the co-evolutionary algorithm works better than SGA in terms of an extended schema theorem. And predator-prey co-evolution and symbiotic co-evolution, typical approaching methods to co-evolution, are reviewed, and dynamic fitness landscape associated with co-evolution is explained. And the experimental results show a co-evolutionary algorithm works well in optimization problems even though in deceptive functions.

• Journal of KIISE:Software and Applications
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• v.32 no.4
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• pp.277-289
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• 2005

To overcome the long design time/high computational effort/low computational performance of phylogenetic learning featuring selection and reproduction, this paper proposes a genetic representation based on XML. Since genetic programs (GP) and genetic operations of this representation are maintained by the invocation of the built-in off-the-shelf XML parser's API, the proposed approach features significant reduced time consumption of GP design process. Handling only semantically correct GPs with standard XML schema can reduce search space and computational effort. Furthermore, computational performance can be improved by the parallelism of GP caused by the utilization of XML, which is a feasible system and wire format for migration of genetic programs in heterogeneous distributed computer environments. To verify the proposed approach, it is applied to the evolution of social behaviors of multiple agents modeling the predator-prey pursuit problem. The results show that the approach can be applied for fast development and time efficiency of GPs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.230-236
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• 1987

The correlation between tintinnid and dinoflagellate by means of seasonal variation of standing crops was investigated at two selected stations in Masan Bay, well-known as a red tide zone in southern coastal waters of Korea, during the period from January 1981 to December 1982. The most dominant dinoflagellates mainly belonged to $20-60\;{\mu}m$ of size class, and Gymnodinium and Prorocentrum were predominant from spring to summer season. Of tintinnid, Favella spp. were most dominant and associated with dinoflagellate blooms at the same season. Especially, Favella spp. were most positively correlated with $40-60\;{\mu}m$ size class of dinoflagellate, and also represented higher multiple corrleation with outer station (St.2), comprising relatively large species of Gymonodinium and Protogonyaulax, than with inner station (St. 1), dominated by Prorocentrum blooms. Thus, the interspecific food selection by size and morphology between tintinnid including Favella and dinoflagellate is recognized and it is considered to be an important factor influenecing on the prey-predator relationship in lower trophic level in the surveyed area.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.160-170
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• 1995

The authors investigated feeding habit of river sculpin(C. poecilopus) were conducted at the Chiak streams from April 1993 to March 1994. The feeding habit of C. poecilopus was mainly acquatic insects, such as Ephemeroptera, Odonata, Plecoptera, Trichoptera, Coleoptera, Diptera, and Nematoda, teleost fishes, fish egg and terrestrial insects. Terrestrial insects in the stomach contents were found mainly in autumn, and teleost fish(Moroco oxycephalus) was in summer. Aquatic insects(Ephemeroptera, Trichoptera and Diptera) constituted the bulk of food items ingested during each season. The prey selection indices for Ephemeroptera were positively selected in summer, and negatively selected in autumn and winter, Tricoptera and Diptera were positively selected in autumn and winter, and negatively selected in summer. Additionally, analysis for stomach contents of guarding males suggests that the parental males eat their own eggs during egg guarding(filial-cannibalism).