• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.9-20
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• 2023

For highway concrete structures, the deterioration of the structure is accelerated due to the increase in the use of deicing materials, and sectional repair work is being frequently carried out to restore performance. However, after the repair work, re-damage such as cracks, delamination, and poor bond performance is exhibited in the repaired sectional area. In this study, overseas repair material requirements were first analyzed, and present domestic requirements were improved repair material performance through field surveys of common concrete structures, laboratory experiments, and test construction on a disused concrete bridge. In addition, performancebased quality requirements were presented so that all materials that meet the required performance can be applied, and different test methods for each material were unified into concrete test methods for consistent test results analysis. The considered performance requirements were compression strength, bending strength, and bond strength for structural properties, and length change rate, crack resistance, thermal expansion coefficient, and elasticity coefficient were for dimensional behavior. For resistance to chloride penetration resistance and freeze-thaw resistance were presented as durability. The proposed requirements for concrete repair materials are expected to contribute to the improvement of the quality of concrete sectional repair work in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.393-407
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• 1997

A survey of biological and chemical characteristics in the middle-northern East Sea of Korea was carried out at 28 stations in October, 1995 on board R/V Tam-Yang. On the basis of the vertical profiles of temperature, salinity and dissolved oxygen, water masses in the study area were divided into 5 major groups; (1) Low Saline Surface Water (LSSW), (2) Tsushima Surface Water (TSW), (3) Tsushima Middle Water (TMW), (4) North Korean Cold Water (NKCW), (5) last Sea Porper Water (ESPW). Other 4 mixed water masses were also observed. It is highly possible that the LSSW which occured at depths of $0\~30m$ in the most southern part of the study area is originated from the Yangtze River (Kiang) of China due to very low salinity $(<32.0\%_{\circ})$ relatively high concentration of dissolved silicate and no sources of freshwater input into that area. Oxygen maximum layer in the vertical profile was located near surface at northern cold waters and became deeper at the warm southern area. Oxygen minimum layer af depths $50\~100m$, which is TMW, were found in only southern area. In the vortical profiles of nutrients, the concentrations were very low in the surface layer and increased drammatically near the thermocline. The highest concentration occurred in the ESPW. The relatively low value of Si/P ratio in the ESPW (13.63) compared to other reports in the East Sea was due to continuous increase of P with depth as well as Si. The N : P ratio was about 6.92, showing that nitrogenous nutrient is the limiting factor for phytoplankton growth. The exponential relationship between Si and P, compared to the linear relationship between N and P, indicates that nitrate and phosphate have approximately the same regenerative pattern, but silicate has delayed regenerative pattern.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.4
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• pp.259-264
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• 2001

Typhoon and neap tide on Cochlodinium polykrikoides bloom and water temperature on disappearance of C. polykrikoides bloom were investigated to elucidate the outbreak mechanism of C. polykrikoides blooms at Naro and Namhae coastal area in South Sea of Korea. The first observation of C. polykrikoides blooms were observed when thermocline was disappeared by typhoon, tide, etc. The first blooms of C. polykrikoides were observed on neap tide or before one day from neap tide in 1996-1998 and 2000. However, thermocline was disappeared by typhoon in 1994 and 1999, the first blooms were observed early 12-30 day than 1996-1998 and 2000. The main reason of disappearance of C. polykrikoides blooms after typhoon on 1997-2000 seems to be other environmental change by typhoon rather than low water temperature. In the future, the first C. polykrikoides bloom will be appear around the first neap tide of latter part of August with breaking down of thermocline, but if the thermocline be collapsed by typhoon in July, the C. polykrikoides bloom will be appear at beginning of August. The outbreak of C. polykrikoides blooms will be explain as follows: The vegetative cells, which was germinated by environmental change or already exist in surface water at low level, input to the surface water, and then nutrients and trace metals which were suppled from out side of C. polykrikoides bloom area inflow to surface. The vegetative cells are growth by the nutrients and trace metals at suitable environmental conditions e.g. water temperature, salinity, and sufficient light.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.230-239
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• 1997

In order to investigate the composition and the actual condition of extractive nitrogenous constituents in Tohajeot (a salted and fermented freshwater shrimp, Caridina denticulata denticulata) and in seasoned Tohajeot which were sold in the markets, the extract was analyzed separately into extractive nitrogen, free amino acids, oligopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds, using specimens collected at the fish markets of Yosu and Naju cities in 1994 and 1995. The salinity of Tohajeot was very high $(23.6{\sim}25.1)%$, but seasoned Tohajeot was relatively low $(8.4{\sim}11.4%)$. The extractive nitrogen in the extracts of Tohajeot and seasoned Tohajeot was $311{\sim}531\;mg\;and\;256{\sim}429\;mg$, and the total of free amino acids in them were $1,159{\sim}2,584\;mg\;and\;1,012{\sim}1,672\;mg$ respectively. Glutamic acid, leucine, lysine, histidine, alanine, ornithine, and tyrosine were the major amino acids in Tohajeot extract, and glutamic acid, lysine, arginine, aspartic acid, histidine, leucine and alanine were the main amino acids in seasoned Tohajeot. As for nucleotides and related compounds in them were $2.64{\sim}4.82\;{\mu}mol\;and\;1.08{\sim}1.93\;{\mu}mol$ respectively. Homarine, trigonelline, glycinebetaine and ${\beta}-alaninebetaine$ were detected in them. Homarine was the most abundant, ranging from 18 mg to 86 mg, but the others were very low. The content of major nitrogenous constituents in Tohajeot extract, such as extractive nitrogen, free amino acids, oligopeptides, nucleotides and related compounds, and betaines, was more abundant than that in seasoned Tohajeot extract. But the nitrogenous constituents of Tohajeot extract were poorer than those of anchovy sauce which was sold in the markets. Possibly, the extractive nitrogenous components, which consisted of total betains, total free amino acids, and phenylalanine might be recommended as the quality indices of standardizing Tohajeot and seasoned Tohajeot.

• Research in Community and Public Health Nursing
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• v.14 no.4
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• pp.568-578
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• 2003

This study was conducted to estimate the effects of self-care program on knowledge and symptoms related hypertension self-care and physiological index in essential hypertensive patients aged between 35-74 year. The subjects for the experiment group and the control group of this study were 70 men and women selected through random sampling from adults at Sangju Red Cross Hospital in Gyeongsanbuk-do, and the experiment was carried out during the period from the 15th of September to the 30th of April in 2002. This study measured systolic and diastolic blood pressure (SBP, DBP, the mean value of the two measures) and total cholesterol (TC) and surveyed the subjects' diet and life style in relation to hypertension using a self-report questionnaire. In order to study the significance of the effects of self-care program, the author carried out t-test, paired t-test, ANCOVA, chi-square analysis and effectiveness index (EI) analysis. Results of the study are as follows: The experiment group got higher mean scores than the control group in the degree of low sodium intake and the degree of high calcium and high potassium intake, and the difference was statistically significant(P<0.05). The effectiveness index of the self-care program in smoking was 0.797 at the 1st posttest and 0.601 at the 2nd posttest, and in physical activities 0.600 at the 1st posttest and 0.849 at the 2nd posttest. The rate of regular antihypertensive drugs intake of the experimental group was higher than that of the control group. and the effectiveness index of the self-care program was 0.715. The mean score of the systolic blood pressure of the experimental group was lower than that of the control group, and the difference was statistically significant(P<0.05). In conclusion, these findings support usefulness of self-care programs in reducing systolic blood pressure and in promoting self-care related to diet and life style for treating and preventing hypertension.

• Journal of Nutrition and Health
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• v.50 no.2
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• pp.180-191
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• 2017

Purpose: The purpose of the study was to identify teacher's knowledge about sodium, dietary behaviors related to sodium, attitudes towards a low-salt diet, and meal attitude guidance as well as examine the relationship between these variables. Methods: The participants were 351 teachers at an elementary school in the Jeonbuk area. The data were analyzed using ANOVA, Duncan test, and Pearson correlation coefficients with SPSS v. 20.0. Results: The score for teachers' knowledge about sodium was 12.92 points of a possible 16, the score for dietary behavior related to sodium was 46.85 points of a possible 70, and the score for attitude towards a low-salt diet was 33.63 points of a possible 50. Their score for meal attitude guidance was 59.95 points of a possible 80. The knowledge showed significant differences by hypertension drug (p < 0.05) and stress level (p < 0.05). The dietary behavior of sodium use showed significant differences by gender (p < 0.01), work experience (p < 0.05), BMI (p < 0.01), drinking (p < 0.05), concern about health (p < 0.05), and stress level (p < 0.05). The attitude towards a low-salt diet showed significant differences by gender (p < 0.05), marital status (p < 0.05), work experience (p < 0.05), drinking (p < 0.05), concern about health (p < 0.001), and stress level (p < 0.05). Meal attitude guidance showed a significant difference by marital status (p < 0.001), age (p < 0.001), work experience (p < 0.001), drinking (p < 0.01), regularity of health checkup (p < 0.001), concern about health (p < 0.001), and stress level (p < 0.05). There was a low positive correlation between knowledge about sodium and dietary behavior related to sodium as well as between dietary behavior related to sodium and attitudes towards a low-salt diet. Attitudes towards a low-salt diet showed a positive correlation with meal attitude guidance. Conclusion: Therefore, it is necessary to consider educational programs on increasing knowledge and attitudes towards a low-salt diet in teachers for improvement of meal attitude guidance activities for students.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.524-540
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• 2013

After the construction of the Geum River estuary dam, we investigated the ecological property of phytoplankton community with physicochemical property in 9 stations of Geum River estuary 4 times seasonally in 2010 about the environmental changes through the change of phytoplankton. Physicochemical property seems to show eutrophication which developed from the tendency of accruing of the nutrients (those involved in intermittency of freshwater which flows from the dike and the surrounding cities), caused by the changing of tidal flow, the decreasing of the inflow of seawater after the construction of the Geum River estuary dam (dike). A total of 233 species of species composition of phytoplankton emerged, showing a highly increased result compared to that of the former research. The reason for the increase in number is considered as a phenomenon resulting from the mix of blackish and freshwater marine species in the flow of intermittency of freshwater discharge. Also, the standing crops of phytoplankton considerably increased compared to when the dike had not yet been built. Highly affected by the discharge of occasional freshwater, the diatoms of blackish water zone dominated in spring and winter, while freshwater species appeared to dominate in summer and autumn. The species diversity showed over 2.0 except in winter season. After a cluster analysis, the result showed that the Geum River estuary was influenced by runoff from cities like Gunsan, the sewage which flows from Gyeongpo River, and the intermittency of freshwater discharge from the Geum River estuary dam.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.693-698
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• 1999

To investigate changes of components in salt-fermented northern sand lance, Ammodytes personatus sauce during fermentation, various chemical properties were examined at 1$\~$3 months intervals during 18 months fermentation. The moisture content decreased slightly, but the content of VBN and crude protein, total nitrogen, amino nitrogen, degree of hydrolysis, and absorbance at 453 nm increased gradually during fermentation. On the other hand, ash content, pH, and salinity showed almost no change. The contents of total nitrogen, amino nitrogen, and degree of hydrolysis increased sharply until 6$\~$8 months fermentation and showed the gentle increment after that, The Hx and uric acid were the most abundant in ATP related compounds, ranging from $83.1\%$ to $92.9\%$, After 18 month of fermentation, sauce was rich in free amino acids, such as glutamic acid, alanine, Iysine, leucine, isoleucine, valine, aspartic acid in that order.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.503-526
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• 1996

A synoptic survery of chemical characteristics in the last Sea of Korea was carried out at the 11 stations near Ullungdo in November, 1994 on board R/V Tam-Yang. On the basis of the vortical distribution patterns of temperature, salinity and dissolved oxygen, water masses in the study area are divided into five groups; 1) Tsushima Surface Water (TSW), 2) Tsushima Middle Water (TMW), 3) East Sea Intermediate Water (ESIW), 4) last Sea Proper Water (ESPW), 5) Mixed Water (MW). In the vertical profiles of nutrients, the concentrations were very low in the surface layer and increased rapidly near the thermocline. There was a slight decrease in the ESIW and the concentrations were constant with the depth below 300m except dissolved silicate which still increased with depth. Relatively high value of Si/P ratio (25.2) in ESPW, whick is the oldest water mass, suggests that Si is regenerating more slowly compared to other nutrients. The relatively high value of N/P ratio (18.6) in the surface layer might be related to high vertical eddy diffusivity $(K_z)$ of $1.19\;cm^{2}/sec$ and high nitrate upward flux of $103.7\;{\mu}g-at/m^{2}/hr$, compared to the values reported in other areas. Apparent Oxygen Utilization (AOU) was very low in the surface layer and increased in the TMW, but there was a slight decrease in the ESIW. The highest value of AOU occurred in the ESPW. The slpoe of P/AOU was 0.50. The study on the relationship between water masses and nutrient distribution patterns is important in understanding the regeneration processes of nutrients in the polar region of the last Sea.

• Journal of Aquaculture
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• v.14 no.3
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• pp.181-195
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• 2001

To stabilize the lantern cage culture system of Patinopecten yessoensis(Jay) in the eastern coast of Korean peninsula, optimum conditions such as time of transplantation, rearing density and depth, and time of harvest were identified. During the period from January 1991 to December 1998, the water temperature ranged from 4.7 to 21.4$^{\circ}C$ at 15-30 m depth and 4.9 to 25.7$^{\circ}C$ at the surface; these thermal ranges were within the optimal ranges (5-23$^{\circ}C$) prevailing at 15-30 m depth at surface water. Annual thermal changes indicated that the prevailing temperature during the years 1993 and 1996 was near optimum, but higher during the years 1994, 1997 and 1998, when mass mortality and growth retardation occurred. Salinity (32.0- 34.4$\textperthousand$) and dissolved oxygen (4.14 -8.11 $\mu\textrm{g}$/l) at 15 m depth were well within the optimum ranges. The chlorophyll concentrations (0.06 - 2.73$\mu\textrm{g}$/l) indicated that the study area was oligotrophic, although mass mortality did occur, when chlorophyll concentrations were high, especially in summer. Hence water temperatures and chlorophyll concentration are major factors related to survival and growth of the scallop. In terms of the shell height maximum growth occurred during spring (March-May; 8 - l3$^{\circ}C$) and fall (October-December; 11-l7$^{\circ}C$) in the lantern cage culture. Slow growth was recorded during late winter January-february; less than 7$^{\circ}C$) and mid-summer (August- September; more than 18$^{\circ}C$). Daily growth of shell height and total weight were 0.02∼0.24 mm and -0.07∼0.90 g at the rearing density of 12 individuals per net. Optimal .earing density in the lantern cage (ø50${\times}$20 cm) was 10∼15 individuals with the shell height of 5∼6 cm. The fastest growth rates were observed at 15∼20 m depth; however, it is recommended that 20∼30 m would be optimal. The scallops require 22 months to attain the commercial size of 10 cm shell height and 140 g total weigh, and are best harvested and sold during March-April.