• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.107-115
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• 2012

In juvenile size, the maximum clearance rate and ingestion rate were 15mm, which is the 70.8 mL/h, 4245.0×104cells/h, respectively. But the lowest clearance rate and ingestion rate were found at 5mm, which is the 4.1 mL/h, 246.0×104cells/h, respectively. The highest clearance rate and ingestion rate of AFDW seen at 7.5mm, with 3.3 mL/mg AFDW/h, 196.0×104cells/mg AFDW/h, respectively. According to the results of water temperature, clearance rate and ingestion rate were lowest at 10℃, showing the 0.3 mL/h, 20.3×104cells/h, respectively. The highest clearance rate and ingestion rate were 25℃, which is the 16.6 mL/h, 993.4×104cells/h, respectively. But in 30℃, clearance rate and ingestion rate decreased to the 12.9 mL/h, 772.6×104cells/h, respectively. With respect to the food density, the experiment groups with 30×104 cells/mL and 240×104 cells/mL showed the clearance rate of 21.1 mL/h and 2.3 mL/h, respectively. But the experimental group with 120×104 cells/mL or more showed decreased clearance rate. While, the maximum ingestion rate was at 60×104 cells/m, showing the 876.2×104cells/h.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.4
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• pp.143-157
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• 2023

This study confirmed the characteristics of macrobenthic community due to anthropogenic environmental changes in the Boryeong Jugyo tidal flat, where the habitat of manila clam (Ruditapes philippinarum) and mud shrimp (Upogebia major) is separated. The total number of occurring species was 55 during the study period with an average habitat density of 338 ind./m² and a biomass of 212.2 gWWt/m². The number of occuring species increased from 27 species at the upper flat to 37 species at the lower flat, and the dominant species differed by tide levels (Upper: Leonnates persica, Middle: Heteromastus filiformis, Lower: R. philippinarum). The macro-benthic community sturctures of the top 10 species using cluster analysis and nMDS were divided into two groups, focusing on Manila clam culture farm of lower flats and middle flats with high habitat density, reflecting the influence of specific species. The sediment composition of the U. major habitat space fluctuated highly, but it was maintained annually, and the sorting coefficient was 2.1 𝜑, and the proportion of the same particle size was increased. In particular, because the middle flat has a dense anthropogenic impact, a dominant species, H. filiformis dominated and revealed a relationship with the density of burrow holes of U. major, which is considered to be a biological interaction between these two macrofauna in this tidal flat.

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.45-55
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• 2001

Gametogenes, reproductive cycle, first sexual maturity(biological minimum size), sex ratio and larval development of the marsh clam Corbicula japonica were investigated monthly by histological observations. Samples were collected in brackish water of Gokgang stream, Kyungsangbuk-Do, Korea, from August 1997 to July 1998. Sexuality of Corbicula japonica is dioecious and the species are an oviparous clam. The gonads are irregularly arranged from the sub-region of mid-intestinal gland in visceral cavity to reticular connective tissue of foot. The ovary is composed of a number of ovarian sac which are branched arborescent. Oogonia actively proliferate along the germinal epithelium of ovarian sac, in which young oocytes are growing. The testis is composed of a number of testicular tubules, and the epithelium of the tubule has function of germinal epithelium, along which spermatogonia actively proliferate. A great number of undifferentiated mesenchymal tissue and eosinophilic granular cells are abundantly distributed between developing oocytes and spermatocytes in the early developmental stages. With the further development of the ovary and testis these tissue and cells gradually disappear. Then the undifferentiated mesenchymal tissue and eosinophilic granular cells are considered to be related to the growing of the oocytes and spermatocytes. The spawning period is from July to September, and the main spawning occur between July and August when seawater temperatures reach above 22$^{\circ}C$. The reproductive cycle of this species can be divided into five successive stages; early active (February to April), late active (May to July), ripe (June to September), partially spawned (July to September), degenerative (September to October) and resting stage (October to February). Percentages of first sexual maturity of female and male clams ranging in length from 10 mm to 12 mm are over 50% and 100% for clams over 16.0 mm in shell length. Fertilized eggs or Corbicula japonica were 80-90 ${\mu}{\textrm}{m}$ in diameter. In the early embryonic development of C. japonica, the appearance of polar body, trochophore and D-shaped veliger were observed around 40 min., 27 hours and 4 days after spawning, respectively, at a water temperature of 26.5-28.$0^{\circ}C$. The size of larvae of early umbo stage was about 185-210 ${\mu}{\textrm}{m}$ in shell length, 160-180 ${\mu}{\textrm}{m}$ in shell height around 7 days after fertilization. The correlation of relative growth between the culture day (D) and shell length (SL) was expressed by the following simple formula from D-shaped veliger to metamorphosing stage; SL = 13.300D + 209.36($r^2$= 0.9078).

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.33-40
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• 2003

To obtain the basic information on culture conditions for the larvae of Saxidomus purpuratus, experiments were conducted on the population from southern coast for (1) the success in fertilization and development from artificial fertilization among different months of a year, (2) the viability of sperms after exposure to seawater, (3) and the effects of temperature, salinity, and food organism on the survival and growth of larvae. Gametes obtained from dissection showed high rate of fertilization at all months. But the rate of development was higher only May-July. Developmental success seemed to be related with the quality of eggs at the time of fertilization. Developmental times for 2-cell, 4-cell, 8-cell, blastula, trochophore larva, and veliger larva at 20$^{\circ}C$ were 1.5, 2, 4, 18, 24, and 32 hr, respectively. Sperms could survive for more than 8 hr, however, actively swimming sperms could be found within 1 hr after exposure to seawater. It is recommended that sperms should be used for fertilization as soon as possible when they are exposed to seawater. At temperature of 35$^{\circ}C$, all the larvae died during 48 hr. Larval survival decreased when salinity was either lower than 20 psu or higher than 40 psu, and was 0% when salinity was 10 psu. Optimal range of temperature and salinity for rearing larvae of S. purpuratus were 20-25$^{\circ}C$ and 20-40 psu, respectively. Larvae grew from 111.5 to 235.3 ${\mu}$m during 21 days. Larvae fed mixed diets grew faster than unialgal diets. The fastest growth was observed when larvae were fed on the mixture of Isochrysis galbana and Nannochloris oculata.

• Journal of Korea Multimedia Society
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• v.7 no.7
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• pp.956-966
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• 2004

The Korean animation has enjoyed the brisk formation and establishment of its world-class infra for the last several years without unified titles or concepts, under the name of a national strategic project in the age of digital image. It also enjoys its new evaluation as digital animation that it's one of the greatest money making business in the non-education and frivolous culture and has the closest relations with the modern time. A great portion of popular image media has been taken by animation for the last 30 years. In this paper we propose a motion algorithm using an animation technology. It was developed for education purposed and accessible through the internet. For instance, in Cyber Clam Museum, 1000 gesture contents, the visual processes were used to design a screen with a realistic image and create an animation that makes possible show at 360 and every such transformation as translation, rotation, and scaling can be applied in the image interactively for the convenient and effective viewing.

• Journal of the Korean Society of Food Culture
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• v.6 no.4
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• pp.351-367
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• 1991

This research was attempted to investigate the correlation between food habits as well as preferences and health conditions of middle-aged people. 380 people living in Dae-gu, kimch$\breve{o}$n and k$\breve{u}$mr$\breve{u}$ng gun in the 40's or 50's were selected for this research as subjects from July 1 to August 15, 1990. The data analysis was made by way of frequency, percentage, ${\chi}^2-test$ and Pearson correlation using SAS package. The summarized results are as follows. 1. Among the total subjects of this research, 200 people (52.6%) were male and 180 people (47.4%) were female. The regional distribution was like this; 115 people (30.3%) lived in large city, 154 people (40.5%) in small and medium city and 111 people (29.2%) in rural region. 2. The survey on food life attitude on the subjects showed that they had a relatively good attitude, and there were little significant differences (p<.05) between men and women. But there were significant differences (p<.001) between rural region and city. 3. On the preferences for taste, food and cooked food the subjects showed the lowest preferences for processed milk-fat food and the highest for soybean and processed soybean food. 4. The research on health condition 1) 30.8% of the subjects were obesity. And this research showed that the percentage of obesity was higher among men (33.5%) than women (27.8%), and higher in cities (40.4, 34.4%) than rural region (16.2%), (p<.05, p<.01). 2) 90.8% of the subjects showed negative according to Diabetes inspection. 3) 2.0% of the subjects were hypertensive, and the percentage was higher among women than men, and higher in rural region than cities. 4) 12.6% of the subjects were anemia, and the percentage was higher among women (17.8%) than men (8.0%), and higher in rural region (23.4%) than cities (7.0, 9.1%). 5) DMFT index and DMF rate of dental caries was higher among women (DMFT index; 10.6 DMF rate; 88.9) than men (DMFT index; 7.3 DMF rate; 81.5), and higher in rural region (DMFT index; 11.8 DMF rate; 90.1) than cities (DMFT index; 7.4, 7.9 DMF rate; 79.1, 85.7). 6) According to the survey on self-diagnosed health status of subjects, the percentages of articular·neuralgia (48.9%) was the highest. And that of stomach digestion troubles (31.1%), headache (22.4%), anxiety excitement (12.9%), spastic constipation (12.4%), insomnia (9.7%), melancholia (7.9%) and etc (1.6%) followed. 7) People had allergied food which contained animal protein such as pork, chicken, mackerel, siakworm pupa, clam and so on. 8) In female cases, 46.7% of women became already menopausal and 13.3% of them was under menopause. 5. This research showed that there were significant correlation between food life attitude and health condition in obesity, anemia and dental caries but not in blood pressure. 6. And this research also showed that there were significant correlations between food preference and health condition in obesity, anemia and dental caries but not in blood pressure.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.314-336
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• 2006

In this treatise, we investigated the Korean literature of main dishes before the 17th century : ${\ulcorner}Sangayorock{\lrcorner}$, ${\ulcorner}Sasichanyocho{\lrcorner}$, ${\ulcorner}Soowonjabbang{\lrcorner}$, ${\ulcorner}Yongjechongwha{\lrcorner}$, ${\ulcorner}Dongyoebogam{\lrcorner}$, ${\ulcorner}Domoondaejak{\lrcorner}$, ${\ulcorner}Geebongyouseul{\lrcorner}$, ${\ulcorner}New-Guwhangchalyo{\lrcorner}$, ${\ulcorner}Eumshickdimibang{\lrcorner}$,, ${\ulcorner}joobangmoon{\lrcorner}$, and ${\ulcorner}Yorock{\lrcorner}$. Main dishes were classified 19 kinds of rice, 64 kinds of gruel, 6 kinds of thin gruel, 1 kind of Moori, 1 kind of rice-cake soup, 37 kinds of noodles and 20 kinds of dumpling. Rice varieties were brown rice, rice, hulled rice, millet rice, foxtail millet rice, barley rice, sesame rice and flax seed rice. Gruel ingredients were cereal, beans, vegetables, nuts or seeds, medical plants or hardy wild plants, poultry, pork's kidney, dog's liver or oyster, clam and/or milk Rice-cake soup was 'Tangbyun' in ${\ulcorner}Domoondaejak{\lrcorner}$. Noodles were divided by main flours: wheat flour, buckwheat flour, mung bean flour and other flours. Noodles were made by pressing or cutting method. Pressing method used a mold with a hole. The husk of dumpling was made by wheat flour, buckwheat flour, mixed flour of wheat and buckwheat, sliced fish or meat, and/or a gray mullet. Another special method was 'Sangwha' made by fermentation. Bun stuffing of dumpling used fishes, meat, vegetables, beans, flours and seasonings. Cooking methods of dumpling were boiling, baking, steaming and pan-frying. From this investigation of the Korean main dishes described in the Korean literature before the 17th century, we expect to develop useful recipes for those who are concerned about health and want longevity, and thereby to advance the Korean food culture.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.94-102
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• 2012

There is a limitation to estimate vitamin $B_{12}$ intake due to a lack of data on vitamin $B_{12}$ content in many Korean foods. In this study, vitamin $B_{12}$ content was determined in some seaweeds, fish, and shellfish and their product that are consumed in Korea using a modified microbioassay with Lactobacillus delbruecki ATCC 7830. Dried laver and dried seasoned and toasted laver contained very high levels of vitamin $B_{12}$ (66.8 and $55.2-71.3\;{\mu}g$/100 g, respectively. Sea lettuce and seaweed fulvescene also contained high vitamin $B_{12}$ content of 5.47-9.41 and $6.46-7.20\;{\mu}g$/100 g, respectively, whereas sea mustard and sea tangle contained low levels of vitamin $B_{12}$; vitamin $B_{12}$ was not detected in seaweed fusifome. Pacific saury, trout, sea-bass, or squid contained 12.01, 2.00, 0.49 and $2.33\;{\mu}g$ vitamin $B_{12}$/100 g, respectively. Ochellatus octopus, and naked sand lance contained 0.72-1.43 and $3.68\;{\mu}g$ vitamin $B_{12}$/100 g, respectively. Dried Alaska pollack con-tained $0.19-2.64\;{\mu}g$ vitamin $B_{12}$/100 g. Shellfish such as little neck clam and small ark shellfish contained high levels of vitamin $B_{12}$ of $30.5-40.5\;{\mu}g$/100 g, and mussel and abalone contained 17.71 and $7.82\;{\mu}g$/100 g, respectively. Of unique Korean traditional fermented seafood products, salt-fermented products of squid ($2.91\;{\mu}g$/100 g), clams ($34.31\;{\mu}g$/100 g), Ala-ska pollack roe ($9.98-12.02\;{\mu}g$/100 g), hairtail guts ($4.58\;{\mu}g$/100 g) or small shrimp ($0.58-1.55\;{\mu}g$/100 g), and fish sauce from anchovies ($1.52-1.78\;{\mu}g$/100 mL), sand eel ($0.22-0.24\;{\mu}g$/100 mL) or small shrimp ($0.19-0.78\;{\mu}g$/100 mL) were analyzed. A few commercial brands of flying fish roe ($0.73-1.73\;{\mu}g$/100 g), canned tuna ($0.40\;{\mu}g$/100 g), and fried fish paste ($0.25-0.69\;{\mu}g$/100 g) were also analyzed. In conclusion, vitamin $B_{12}$ content in these foods, chosen considering the Korean food culture, should contribute to improve the present vitamin $B_{12}$ food database. It may be helpful to estimate vitamin $B_{12}$ intake more correctly than before, and provide additional information for dietary education related to vitamin $B_{12}$ and meal management.

• Journal of Life Science
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• v.28 no.12
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• pp.1424-1431
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• 2018

We prepared flocculated detritus-like organic marine snow originating from various organisms by fermentation using microorganisms; this fermented organic material was fed to the leptocephali of the eel (Anguilla japonica) to investigate whether or not such organic matter was an appropriate food source for the larvae. A strain was isolated from a biofloc technology system used to culture fish, and seven types of organic material from hen's egg, eel muscle, tuna muscle, lugworm, shrimp, manila clam, mussel, and sea squirt were fermented using isolated bacteria (Bacillus sp.). The fermented matter did not show any specific form and was larger than $10-20{\mu}m$ but no more than $100{\mu}m$ in size. Four diets (A-D) were prepared using the various fermented products, and the larvae were fed the prepared food from 20 days after hatching. The leptocephali fed the A, B, and C diets survived until 37, 39, and 37 days after hatching, respectively. However, the leptocephali fed the D diet survived for 60 days after hatching. The protein content of each diet was very similar, but the n-3 HUFA concentration in the D diet was approximately twice as high as that of the others.