• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.106-106
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• 2015

The information of flow regimes continues to be norm in water resource and watershed management, in that stream flow regime is a crucial factor influencing water quality, geomorphology, and the community structure of stream biota. The objectives of this study were to estimate Korean stream flows from landscape variables, classify stream flow gages using hydraulic characteristics, and then apply these methods to ungaged biological monitoring sites for effective ecological assessment. Here I used a linear modeling approach (MLR, PCA, and PCR) to describe and predict seasonal flow statistics from landscape variables. MLR models were successfully built for a range of exceedance discharges and time frames (annual, January, May, July, and October), and these models explained a high degree of the observed variation with r squares ranging from 0.555 (Q95 in January) to 0.899 (Q05 in July). In validation testing, predicted and observed exceedance discharges were all significantly correlated (p<0.01) and for most models no significant difference was found between predicted and observed values (Paired samples T-test; p>0.05). I classified Korean stream flow regimes with respect to hydraulic and hydrologic regime into four categories: flashier and higher-powered (F-HP), flashier and lower-powered (F-LP), more stable and higher-powered (S-HP), and more stable and lower-powered (S-LP). These four categories of Korean streams were related to with the characteristics of environmental variables, such as catchment size, site slope, stream order, and land use patterns. I then applied the models at 684 ungaged biological sampling sites used in the National Aquatic Ecological Monitoring Program in order to classify them with respect to basic hydrologic characteristics and similarity to the government's array of hydrologic gauging stations. Flashier-lower powered sites appeared to be relatively over-represented and more stable-higher powered sites under-represented in the bioassessment data sets.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.1-10
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• 2016

Despite it has been mentioned that the successful restoration in landscape level was achieved in the Young-il soil erosion control project, quantitative evaluation of restored plant communities (Alnus firma as introduced species and Pinus thunbergii as native species) was hardly founded. Light availability, litter and woody debris cover, and forest structure and composition were determined for 500 m² band-quadrat in three forest types. Abiotic factors of Q. serrata stands, as reference forest, and A. firma stands were similar but not for P. thunbergii stands. There were no significant difference on mean stem density (stems ha^-1, H = 3.6, p = 0.162), and the mean basal area of each stand had marginal significance (m² ha^-1, H = 5.7, p = 0.058) among stands as total basal area was higher with the order of A. firma (21.4 m² ha^-1), P. thunbergii (19.8 m² ha^-1) and Q. serrata (16.2 m² ha^-1). Restoration of vegetation structure was more effective in fast-growing and N-fixing A. firma, as introduced species plantation. However, result of MRPP, NMS ordination and ISPAN for herbaceous layer, not for tree and shrub species composition, indicated that restoration of ground vegetation was likely influenced highly from local environment. Propagule availability from landscape context such as connectedness to natural vegetation and management practices in restored isolated stands are available explanations for restoration effects and gaps between restored plantations and secondary oak forest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.16-22
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• 2021

This study investigated the reduction in human norovirus (HNV) GII. 4 count in pacific oyster Crassostrea gigas using electron beam irradiation. Infectious HNV GII. 4 was detected using RT-qPCR (real time reverse transcription-quantitative polymerase chain reaction) with PMA (propidium monoazide)/sarkosyl. At electron beam doses 1, 5, 7, and 10 kGy, the count of HNV GII. 4 was 2.74, 2.37, 2.06, and 1.55 log copies/μL (control, 3.01 log copy/μL), respectively, confirming that as the irradiation dose increased, norovirus count reduced significantly (P<0.05). After PMA/sarkosyl treatment, the counts further reduced at the same irradiation dose, and 10 kGy showed significant differences between the non-treated and PMA/sarkosyl-treated samples (P<0.05). The Ed (decimal reduction dose of electron beam) value based on the first-order kinetic model was 7.33 kGy (R2=0.98). No significant difference was observed in the pH values of the control (6.2) and electron beam-irradiated samples at all doses (6.1). For sensory evaluation, the non-treated sample scored the highest in all categories (5.25-6.17), while the samples treated with 10 kGy showed the lowest score (4.67-5.33), although without statistical significance (P>0.05). Overall, our results suggest that 7 kGy electron beam is sufficient for the non-thermal sterilization of oysters without causing significant changes in quality.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.1-8
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• 1996

Recently, much attention has been paid to problems which is concerned with voltage instability phenomena and much works on these phenomena have been made. In this paper, by substituting d $P_{k}$ d $e_{k}$ ( $v^{\rarw}$= e +j f) for $P_{k}$ in conventional load flow, direct method for finging the limit of voltage stability is proposed. Here, by using the fact that taylor se- ries expansion in .DELTA. $P_{k}$ and .DELTA. $Q_{k}$ is terminated at the second-order terms, constraint equation (d $P_{k}$ d $e_{k}$ =0) and power flow equations are formulated with new variables .DSLTA. e and .DELTA.f, so partial differentiations for constraint equation are precisely calculated. The fact that iteratively calculated equations are reformulated with new variables .DELTA.e and .DELTA.f means that limit of voltage stability can be traced precisely through recalculation of jacobian matrix at e+.DELTA.e and f+.DELTA.f state. Then, during iterative process divergence may be avoid. Also, as elements of Hessian mat rix are constant, its computations are required only once during iterative process. Results of application of the proposed method to sample systems are presented. (author). 13 refs., 11 figs., 4 tab.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.191-195
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• 2004

An investigation was conducted to ascertain the basic information on characteristics of embryonic tissue development among Korean Ginseng, American ginseng, $F_{1}$ hybrids and $BC_{1}F_{1}(F_{1}$ pollen back cross to $BC_{1}=Korean\;Ginseng)seeds$. The specific activities of lipoxygenase (LOX) and the protein assays were made during the above embry­onic growth period at 5 or 25 degree C. The results are summarized as follows: The fresh weights(mg) of germinating seeds were significantly different among species. Ginseng seeds were stratified at $5^{\circ}C\;for\;60\;days$ the ratios of embryo/endosperms in $P.g.,\;P.q\;or\;F_{1}\;were\;about\;90{\%}$. The ratio was in $BC_{1}F_{1},\;79.2{\%}$ during the same period. The ratios of embryo/endosperms of seeds of P.g. or P.q. germinated at $5^{\circ}C$ showed rather higher values as compared to that at $25^{\circ}C$ LOX specific activity the highest in the $F_{1}$ and decreased in the order of P.g., P.q., and $BC_{1}F_{1}$. The highest LOX specific activity was shown at 80 days after sowing, followed by 70 days sowing, the least LOX activity was shown at 60 days.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.748-752
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• 1995

Canned and bottled orange juices currently sold in Korean market were stored for 24 weeks at 20, 30, 40 and $50^{\circ}C$ and analyzed after opening at 4 week intervals. Activation energy, $Q_{10}$ values and shelf-life at respective temperatures were calculated from the data on various quality indexes. Proposed indexes were lead, tin, iron and vitamin C contents in canned juices and vitamin C content and browning index in bottled juices and $Q_{10}$ values for these parameters were in the range of $1.3{\sim}2.0$. Shelf-life calculated for canned juices at 10, 20 and $30^{\circ}C$ were 10, 6 and 3 months and that in bottled juices, 24, 12 and 6 months, respectively. When the distribution temperature of juices in Korea is assumed to be $15^{\circ}C$ average, the optimum shelf-life was estimated to be 8 months in canned juices and 18 months in bottled juices. In order to ascertain the safety of canned orange juices, efforts are needed to re-examine the recommended distribution period, legal limit for lead and improvement of container materials.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.29-35
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• 2009

In this study, the effect of pH and temperature on the adsorption behavior of acid mine drainage (AMD) on coal mine drainage sludge (CMDS) has been investigated during the treatment of coal mine drainage (CMD) by electrical purification method. The pH$_{zero\;point\;charge}$ (pH$_{zpc}$) of CMDS was 5. The removal ratio of copper, zinc, cadmium, iron were increased according to the increase of pH value. The adsorption amount of copper showed 0.64 mg g$^{-1}$ sludge. It was independent of pH value. The adsorption amount of the other metals showed l.l times when pH was 3. The adsorption amount of chromium was a little bit increased at the pH value higher than 7 due to a small amount of the chromium was eluted as $Cr(OH)_6^{3-}$. The amount of metals' absorption were decreased according to temperature was increase at pH value was 3. The selectivity order was Cd>Fe > Zn > Cu. The amount of absorption showed q$_{max}$ Cu 2.747 mg g$^{-1}$ andZn 2.525 mg g$^{-1}$ when pH value higher than 5. It was independent of temperature.

• Korean Journal of Hospice Care
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• v.8 no.1
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• pp.13-28
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• 2008

Purpose: This paper aims to examine the subjective structures and types of school age children's perception of death through an investigative study on their perception of death in order to provide a basic material for them to understand death, and develop and carry out an effective death education program. Methods: The study method used the Q Methodology which can investigate the subjective structures and types of school age children's perception of death. For Q-population, 20 school age children were used as subjects for neutral interviews and open surveys, and through documentary research, a total of 132 statements were collected, For Q-samples, 23 statements (Q-samples) were derived through a non-structural method. P-samples were 31 school age children (8-13 year olds), Q-sorting was carried out using Q-cards, and the collected data was analyzed using the PC QUANL program. Results: As a result of the study, children's perception of death was divided into five types. The first type was functional type, characterized by prominent subjective perception regarding the elements of death, such as non-reversibility, universality, non-functionality, and causality. The second was after-life type, characterized by a strong, focus on life after death in one's perception of death, and it included children with Christian background and those who had experienced death in their immediate family. The third was religious type, characterized by a strong belief in being able to still watch over one's family and friends after one's death, resulting in a positive faith in the after-life. The fourth was fearful type, characterized by a deeper fear of death in comparison to other types. The fifth was realistic type, characterized by a strong and positive assent to the perception of good death. Conclusion: The significance of the results of this paper's study to Nursing is as follows. In terms of understanding the subjectivity of school age children's perception of death in nursing practice, and understanding the compositional elements of death presented with strong emphasis in existing literature and studies, the results will expand these understandings and allow us to understand the level of perception in school age children regarding the definition of death, after-life, and good death, be utilized as useful material in developing an effective death education program for them according to their type characteristics, and become the fertilizer for enabling the children to live a proper life and preventing the tendency to make light of death that occur in adolescence and the spread of suicides. In terms of nursing theory, the description and examination of the subjective structures and the characteristics of the different, types of school age children's perception of death can be utilized as useful material for building a model of school age children's perception of death, and be further used for teaching respect for life. In terms of nursing research, the results can contribute to research describing the effects of nursing intervention strategies and developing tools for providing psychosocial nursing in terms of giving school age children a positive perception of death according to their types as well respect for life.

• Journal of the Korean Geotechnical Society
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• v.29 no.9
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• pp.43-54
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• 2013

This study proposed a new embankment stability control method to analyze the measurement data on the slope activities of the soft ground, using the Stability Control Index (SCI) obtained from the p-q stress paths. In order to validate this new technique, the data from triaxial compression tests (CU) and field measurement were compared. SCI is calculated from the current path of the effective stress points ($p^{\prime}=p-{\Delta}u$) using the relative position between the Total Stress Path $p_{max}$ and the point of $k_f$ line $p_f$. From this result, the point of effective stress $p^{\prime}(=p-{\Delta}u)$ will have access to the point $p_f$ of $k_f$ line when the pore water pressure occurs or the point of total stress pass $p^{\prime}_{max}$ when the pore pressure dissipates. Thus, the Stability Control Index (SCI) can evaluate quantitatively the safety of embankment from the relative position of the effective stress path.

• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.25-43
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• 1992

A survey of Orimok, Yongsil and Donnaeko area forest in Mt. Halla. was conducted using 71 sample plots of 500$m^2$ size. In the analysis of -actual vegetation, Carpinus tschonoskii and C. laxiflora community covered 53.7%, Quercus grosseserrata - Q. serrata community 25.8%, Pinus densiflora community 8.3%, Abies koreana community 4.5% and these communities covered 92.2% of Mt. Halla forest. The degree of 8, 9 and 10 in human disturbance of vegetation covered 64.5, 28.6 and 6.9% respectively. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify them into several groups based on woody plants and environmental variables. By two techniques, the plant community were divided into several groups by the aspect and altitude. The dividing groups are C. tschonoskii community, C. tschonoskii - Q. serrata community, P. densiflora - C. tschonoskii community, P. densiflora - C. laxiflora community, C. laxiflora community, C. laxifrora - Daphniphyllum macropodum - Eurya japonica community, P. densiflora community. The successional trends of tree species by both techniques seem to be from P. densiflora. Sorbus alnifolia through Q. serrata. Maackia faurier to C. tsihonoskii in Orimok and Yongsil area and from P. densifiora to C. laxiflora in Donnaeko area. There was no difference between the stand scores of. DCA and environmental variables.