• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.310-321
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• 2014

Change in fish species composition after the Hebei Spirit oil spill in December 2007 off Taean were determined by analysis of samples collected in Mailpo beach, 10 km south from the oil spill site and polluted by the crude oil. Fish samples were collected by a beach seine in the shallow water at Malipo beach during the low tide of the new moon from February 2008 to December 2009. Five seine hauls were made during the day and the night in each sampling time. Monthly day and night samples did not show the significant differences in species composition. A total of 21 species, 1,032 individuals and 6,544 g of fish were collected in 2008, and 31 species, 4,206 individuals and 35,659 g of fish in 2009. The species collected were composed of the small-sized fish or juveniles. Abundant fishes were the resident species in coastal water, and the migrants were low in abundance. Among the fish occurred, Chelon haematochelius, Sebastes schlegelii, Takifugu niphobles and Pleuronectes yokohamae were predominated in abundance of both years. Monthly fish abundance and species diversity in 2008 were significantly lower than those in 2009. A few number of resident fish were collected from February to June 2008 showing the lowest in May 2008, and fish abundance increased from July 2008. The number of species and abundance of fish in 2009 were increased in spring as the temperature raised, showed a peak in summer and decreased in autumn. This monthly variation in fish species composition and abundance was similar to those in the non-polluted water in other temperate waters. Low fish abundance during several months after oil spill was considered to be related to the residual oil in the water and habitat disturbance due to oil cleaning activity in the beach. Monthly fish species compositions after September 2008 were similar to those of 2009 suggested that the impact on the shallow water fish by the oil residuals was not too significant at least to the fish species composition after September 2008.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.2
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• pp.111-116
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• 2020

This study was conducted to determine the maintenance energy requirements of growing goats in order to establish an appropriate energy benefit system, to reduce feed costs and improve livestock productivity of goat farmers, and to present basic data for detailed specifications afterwards. This experiment was conducted as a group specification test for a total of 3 months, with 32 goats of three months age and conducted by four treatments with different energy levels (T1: NRC+0%, T2: NRC+10%, T3: NRC+20%, and T4: NRC+30%). The average daily gain was the highest in the treated with NRC + 10% of the energy level of the experimental diet, and the feed conversion ratio was in the range of 6.3 g to 7.3 g in the group feeding experiment. Although there was no significant difference in digestibility between treatments, the digestibility of dry matter, crude protein, and crude fat was higher in T2 treated with NRC + 10% than the other treatments. Through the regression equation of the values of MEI and ADG obtained through the experiment (Y=0.5439X+111.51, R²=0.712), the maintenance energy requirement of the goat in the growing period was estimated to be 111.51 kcal/kgBW^0.75.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.219-226
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• 2014

Evaluation of tree responses to temperature elevation is critical for a development of forest management techniques coping with climate change. We conducted a study on the growth responses of Betula costata, Fraxinus rhynchophylla, and Quercus variabilis seedlings to open-field artificial warming. Artificial warming set-up using infra-red heater was built in 2012 and the temperature in warmed plots was regulated to be consistently $3^{\circ}C$ higher than that of control plots. The seeds of three species were sown, and the responses of growth, biomass allocation, and net photosynthetic rate of newly-germinated seedlings on the open-field artificial warming were determined. As a result, the growth responses of the seedlings differed with the species. B. costata showed decreases in the height to diameter ratio (H/D ratio), biomass, root weight to shoot weight ratio, and net photosynthetic rate. However, root collar diameter (RCD), height, biomass, and net photosynthetic rate of Q. variabilis were increased, while the response of F. rhynchophylla was rather obscure. There was no significant difference between warmed and control plots in seedling growth for 3 species in July, whereas, RCD, height, and H/D ratio of Q. variabilis were increased and H/D ratio of B. costata was decreased in November under warming. Species-specific growth responses to warming were similar to the species-specific responses of net photosynthetic rate and biomass allocation; therefore, net photosynthetic rate and biomass allocation might attribute to growth responses to warming. Besides, a relatively obvious response in autumn compared to summer might be affected by the phenological change following artificial warming. Species-specific responses of three deciduous species to warming in this study could be applied to the development of adaptive forest management policies to climate change.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.39-47
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• 2003

The leaf aqueous extracts from five gymnosperms plant were investigated for allelopathy with five Hibiscus syriacus varieties. The leaf aqueous extract of Pinus rigida had the highest total phenolic compound of 2.21mg/L, whereas the soil under Pinus koraiensis canopy had the highest total phenolic compound of 1.38mg/L. Fourteen phenolic compounds were isolated from five gymnosperm plants by HPLC. Among them, phenolic compounds were the highest in P. rigida (320.56 g/mg) with the primary compound 5-sulfosalicylic acid (312.55 g/mg). The correlation between leaf total phenolic compound and pH was not significant, while the total phenolic compound of the leaf extract changed soil pH. The relative seed germination of H. syriacus varieties showed 25% was threshold concentration. The germination rates of varieties were similar to the control group or showed slight stimulation to treatment of P. koraiensis extract. H. syriacus Cambanha was similar to the control group or showed stimulation in all treated groups. H. syriacus Seohohyang showed stimulation in both root and shoot growth compared to the control group. In other varieties except Seohohyang, shoot growth was similar to the control group, while root growth was stimulated in all treated groups. The extracts of tested gymnosperms showed significantly more stimulation to transplanted Seohohyang seedlings, whereas others were similar to control or inhibited in the greenhouse. The dry weight of Seohohyang was greater in all treated groups than the control group, while other varieties were inhibited. All gymnosperm extracts stimulated the chlorophyll contents of Seohohyang and H. syriacus Koyoro but other varieties were not significantly affected. Accordingly, it is suggested that Seohohyang seems the most desirable when planted within these five gymnosperms.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.1
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• pp.1-19
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• 2018

In order to compare significant wave height (SWH) data from multi-satellites (GFO, Jason-1, Envisat, Jason-2, Cryosat-2, SARAL) and SWH measurements from Ieodo Ocean Research Station (IORS), we constructed a 12 year matchup database between satellite and IORS measurements from December 2004 to May 2016. The satellite SWH showed a root mean square error (RMSE) of about 0.34 m and a positive bias of 0.17 m with respect to the IORS wave height. The satellite data and IORS wave height data did not show any specific seasonal variations or interannual variability, which confirmed the consistency of satellite data. The effect of the wind field on the difference of the SWH data between satellite and IORS was investigated. As a result, a similar result was observed in which a positive biases of about 0.17 m occurred on all satellites. In order to understand the effects of topography and the influence of the construction structures of IORS on the SWH differences, we investigated the directional dependency of differences of wave height, however, no statistically significant characteristics of the differences were revealed. As a result of analyzing the characteristics of the error as a function of the distance between the satellite and the IORS, the biases are almost constant about 0.14 m regardless of the distance. By contrast, the amplitude of the SWH differences, the maximum value minus the minimum value at a given distance range, was found to increase linearly as the distance was increased. On the other hand, as a result of the accuracy evaluation of the satellite SWH from the Donghae marine meteorological buoy of Korea Meteorological Administration, the satellite SWH presented a relatively small RMSE of about 0.27 m and no specific characteristics of bias such as the validation results at IORS. In this paper, we propose a conversion formula to correct the significant wave data of IORS with the satellite SWH data. In addition, this study emphasizes that the reliability of data should be prioritized to be extensively utilized and presents specific methods and strategies in order to upgrade the IORS as an international world-wide marine observation site.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.871-878
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• 2005

This experiment was performed to examine the allelopathy effect of allelochemical substance on the crop plants. According to the experiment of the allelochemical substances in Hypochaeris radicata by HPLC, there are the differences at each part of plants. However, it is ascertained that there are 14 kinds of phenolic compounds ingredients that are $\rho$-hydroxybenzoic acid, chlorogenic acid, catechin, caffeic acid, syringic acid, salicylic acid, $\rho$-coumaric acid, ferulic acid, naringin, hesperidin, myricetin, trans-cinnamic acid, quercetin and naringenin. The chemicals like caffeic acid, ferulic acid, and naringenin are commonly included. The result of the chemical experiment shows that there are the differences at each season and part of plants. The leaves in May and blossoms and roots in July contain lots of phenolic acids. It is very high contents such as salicylic acid 2085.6 ${\mu}g/g$ and quercetin 1522.0 ${\mu}g/g$, especially in roots of plants. The result on the growth of crop plants treated by the aqueous extract of Hypochaeris radicata shows that the value of the control group and the test group are same in some cases. However, because the treat value of test group is towel'than that of control group in all items of the experiment, it is cofirmed that the growth of crop plants was inhibited and that the inhibitory effect was increased as its density of treatment was increased. The result of change in quantity shows that there are the differences at each kind of crop plants, but the inhibitory effect was increased as its concentration of treatment was increase with entire. As results, it is confirmed that H. radicata has the allelopathy effect to the crop plants. Especially the inhibitory effect on growth is high in gramineous crop, italian ryegrass and leguminous crop. purple alfalfa.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.652-660
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• 2002

To develop natural food preservatives for extending the shelf-life of jeotkal (salted and fermented seafood), antimicrobial substances were extracted from 32 types of medicinal herbs and edible plants using 95% ethanol. Among the extracts, Glycyrrhizae radix, Curcumae domestica, Galla rhois, and Resina pini showed relatively high inhibitory effects on the growth of the microorganisms isolated from the deteriorated jeotkal. We selected and tested the extract from Recina pini as a natural jeotkal preservative. This ethanol extract was purified partially by adding equal quantity of water, through which 77% of insoluble materials were removed as impurities. In manufacturing modified jeotkal using squid, sucrose and starch syrup were substituted with sorbitol, $glucono-{\delta}-lactone$ was added instead of vitamin C and lactic acid, and sterilized hot pepper was used instead of natural one. The shelf-life of modified jeotkal was prolonged by 4 days compared with the control jeotkal when stored at $20^{\circ}C$, while that of modified jeotkal containing 1.0% partially purified Recina pini extract was prolonged by 6 days compared to the control. The same tests were conducted for the changran (stomach and intestine of Alaska pollack) jeotkal preservation. The shelf-life of the control jeotkal was 24 days, whereas the modified jeotkal and the Resina pini extract-containing modified jeotkal maintained their qualities without changes in microbial and chemical characteristics for 90 days at $20^{\circ}C$ storage.

• Journal of Korean Society of Forest Science
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• v.7 no.1
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• pp.8-18
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• 1968

This experiment is a comparative study of influence on the seedling in individual pH treatment of culture soil I. T-R ratio and growth 1. T-R ratio has almost similar tendency in its range according to tree species, but in individual treatment there were lots of differences. In the strong acidic and the strong alkali conditions T-R ratio was small. This means the seedling body is out of balance. 2. Where the resistance to H-ion was stronger, the growth of root-system, that is, the resistance of fine root was comparatively better. 3. The growth of root system was greatly influenced by pH, and in the condition of pH3, pH8, pH9, the growth was especially worse. 4. Ginkgo biloba, Pinus rigida and Pinus banksiana kept on growing in the strong acidic condition. 5. The growth season has higher pH of culture soil than the dormant season, and tree species which have strong resistance of acidic had better growth and had stronger resistance of draught in the acidic condition of culture soil ; especially, Pinus rigida and Pinus banksiana were worse in the alkali condition. II Seedling pH 1. According to the tree species, there were differences in seedling pH, and tree species, considred to be strong in resistance of draught, had been high in seedling pH. 2. Seedling pH of the growth season was higher than that of the dormant season. 3. Seedling pH was not significant in pH treatment of the culture soil.

• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1457-1468
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• 2018

The sigma naught (${\sigma}^0$) equation is essential to calculate geo-physical properties from Synthetic Aperture Radar (SAR) images for the applications such as ground target identification,surface classification, sea wind speed calculation, and soil moisture estimation. In this paper, we are suggesting new Kompsat-5 (K5) Radar Cross Section (RCS) and ${\sigma}^0$ equations reflecting the final SAR processor update and absolute radiometric calibration in order to increase the application of K5 SAR images. Firstly, we analyzed the accuracy of the K5 RCS equation by using trihedral corner reflectors installed in the Kompsat calibration site in Mongolia. The average difference between the calculated values using RCS equation and the measured values with K5 SAR processor was about $0.2dBm^2$ for Spotlight and Stripmap imaging modes. In addition, the verification of the K5 ${\sigma}^0$ equation was carried out using the TerraSAR-X (TSX) and Sentinel-1A (S-1A) SAR images over Amazon rainforest, where the backscattering characteristics are not significantly affected by the seasonal change. The calculated ${\sigma}^0$ difference between K5 and TSX/S-1A was less than 0.6 dB. Considering the K5 absolute radiometric accuracy requirement, which is 2.0 dB ($1{\sigma}$), the average difference of $0.2dBm^2$ for RCS equation and the maximum difference of 0.6 dB for ${\sigma}^0$ equation show that the accuracies of the suggested equations are relatively high. In the future, the validity of the suggested RCS and ${\sigma}^0$ equations is expected to be verified through the application such as sea wind speed calculation, where quantitative analysis is possible.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.409-416
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• 2013

Recently, the property damage has been increasing due to climate change in South Korea. While the general public has become more aware of the environmental issues, but the environmental education system has not been able to meet up with the demands of the public. The purpose of this study is to suggest preliminary data which is needed for developing a environmental textbook. A survey was conducted to meet the following requirements. Respondent's level of interest in problems or situations concerning the following eight themes: fundamental science, health and medicine, aerospace engineering, life science, electrical electronics, telecommunication, mineral and energy resources, environment. The data was collected from 139 students in Seoul and Gyeonggi province. The results showed that health and medicine issues interest students the most (49.6%), followed by environment (46.8%). We asked the respondents who were very interested in each question for their reasons, and they answered that environmental issue is related to the improvement of their life quality (53.8%) than their curiosity (38.5%). Students were very interested in the other issues because of just curiosity. Most students (90.6%) said seasonal change was not same each year. 18.0% of respondents replied that they and their friends had experienced climate change. The majority of students (94.2%) thought that they will experience natural disaster blamed on climate change during their life. In other words, climate change is already the day-to-day events of their lives. The majority of their opinions, more then three than ten students(30.9%) said the South Korean government should conduct an energy saving campaign to climate change problems followed by expanding new renewable energy (24.5%), conducting adaptation policies of climate change(22.3 %), introducing of a system as like $CO_2$ emissions trading(20.9%) and so on. There are more Stu- dents (69.1%) who know of new renewable energy than students who don't know it; however, respondents who know the meaning very well were just 18.7% showing that most students dimly know the meaning of new renewable energy.