• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.1
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• pp.1-9
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• 2008

In seismic response analysis of building structures, the input ground accelerations have considerable effect on the nonlinear response characteristics of structures. The characteristics of soil and the locality of the site where those ground motions were recorded affect on the contents of earthquake waves. Therefore, it is difficult to select appropriate input ground motions for seismic response analysis. This study describes a generation of artificial earthquake wave compatible with seismic design spectrum, and also evaluates the seismic response values of multistory reinforced concrete structures by the simulated earthquake motions. The artificial earthquake wave are generated according to the previously recorded earthquake waves in past major earthquake events. The artificial wave have identical phase angles to the recorded earthquake wave, and their overall response spectra are compatible with seismic design spectrum with 5% critical viscous damping. The input ground motions applied to this study have identical elastic acceleration response spectra, but have different phase angles. The purpose of this study is to investigate their validity as input ground motion for nonlinear seismic response analysis. As expected, the response quantifies by simulated earthquake waves present better stable than those by real recording of ground motion. It was concluded that the artificial earthquake waves generated in this paper are applicable as input ground motions for a seismic response analysis of building structures. It was also found that strength of input ground motions for seismic analysis are suitable to be normalize as elastic acceleration spectra.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.75-82
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• 2014

Recently, public works becoming bigger in Jeju are implemented various kinds of ground reinforcement method including the chemical grouting method. In this study, we have been investigated on the proper material and the injection condition for the excellent injection effect and the excellent strength of injection material and the permanent waterproof and reinforcement through the experiment. The kind of injection material has been selected through the uniaxial compression test and the endurance test of injection material as the chamber test. An experiment was performed with model ground made of scoria, the injection performance of selected material has been identified through the evaluation test of injection range using the decision test of injection amount and the calibration chamber test. As a result of test, it has been analyzed that MSG appeared to have the excellent strength, durability and injection performance all compared with the ordinary cement, this result is judged to be possible as the ancillary data of design at time of design and construction with the chemical grouting method in the future.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.257-264
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• 2017

Pseudomonas veronii MS1 and P. migulae MS2 have several mechanisms of copper resistance and plant growth promoting capability, and also can alleviate abiotic stress in plant by hydrolysis of a precursor of stress ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC deaminase. In 4-week pot test for tomato growth in soil contained 700 mg/kg Cu, inoculation of MS1 and MS2 significantly increased root and shoot lengths, wet weight and dry weight of tomato plants compared to those of uninoculated control. The inoculated tomato plants contained less amounts of proline that can protect plants from abiotic stress, and malondialdehyde, an oxidative stress marker than those of control. ACC synthase genes, ACS4 and ACS6, and ACC oxidase genes, ACO1 and ACO4, both involved in ethylene synthesis, were strongly expressed in Cu stressed tomato, whereas significantly reduced in tomato inoculated with MS1 and MS2. Also, a gene encoding a metal binding protein metallothionein, MT2 showed similar expression pattern with above genes. All these results indicated that these rhizobacteria could confer Cu resistance to tomato plant under Cu stress and allowed a lower level of Cu stress and growth promotion.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.222-227
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• 2008

Objective of this Research was to determine the influence of foliar application of $CaCl_2$ or $K_2SI_2O_5$ and soil application of $CaCO_3$ or $SiO_2$ on growth and cut flower quality of Zantedeschia aethiopica 'Wedding March'. To achieve this, $CaCl_2$ or $K_2SI_2O_5$ were applied at six leaf stage with the concentration of 0.05, 0.1 and 0.2% and $CaCO_3$ or $SiO_2$ were applied as basal fertilization with the amount of 100, 200, 400kg per 10a or 50, 100, 200, 400kg per 10a respectively. Plant material was used Zantedeschia aethiopica 'Wedding March'. Among calcium chloride($CaCl_2$) and calcium carbonate($CaCO_3$), calcium chloride foliar application was more effective than calcium carbonate with basal fertilization to growth of common calla 'Wedding March'. In the 0.1% solution foliar application of calcium chloride, plant height, leaf length and length of cut-flower was more longer than control. Length of leaf petiole was more longer and leaf fresh weight was more heavier than control. The degree of petiole hardness was more effective in the 0.1% solution calcium chloride foliar application than any other treatment. In the silicate fertilization treatment, plant height of 50kg per 10a treatment was most highest as 73.9cm. also its length of leaf petiole and leaf fresh weight was more effective than any other treatment. The hardness of petiole was better in the 50kg per 10a silicate fertilizer treatment. The cell shape of leaf petiole was round and tissue was regular in the treatment of 0.1% calcium chloride and 50kg per 10a silicate fertilizer but the cell of control was irregular round type. Macro element content of calcium was more amount in the treatment of silicate 50kg per 10a basal fertilization. The infected ratio of Erwinia was no relation with lime and silicate fertilizer treatment. Lime fertilizer treatment is effective for growth and flowering of Calla than silicate fertilizer and the suitable concentration was 0.1%.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.907-915
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• 2019

This study aims to identify the most tolerant species under salinity stress from amongst Asteraceae and Poaceae. The seeds of six species were exposed to different concentrations of $CaCl_2$ (0, 9, 18, 45, 90 mM) and NaCl (0, 17, 34, 85, 170 mM), and germination was measured once every two days. The results indicated that percent germination of the six species of Asteraceae and Poaceae seeds were affected differently by changes in salinity concentration. Seed germination was reduced as salinity levels increase, and longer mean germination times correlated to lower percent germination and earlier germination cessation. Both Asteraceae and Poaceae seeds had the highest germination rates at 18 mM $CaCl_2$ and 34 mM NaCl, and seed germination and growth were severely reduced at salinities greater than 90 mM $CaCl_2$ and 170 mM NaCl. In the seeds of Poaceae, salt resistance was strong in the order of Miscanthus sinensis Andersson, Pennisetum alopecuroides (L.) Spreng., and Phragmites communis Trin. In the seeds of Asteraceae, salt resistance was strong in the order of Dendranthema zawadskii var. latilobum (Maxim.) Kitam, Aster yomena (Kitam.) Honda, and Dendranthema boreale (Makino) Ling ex Kitam.. Overall, the germination rate was higher in Asteraceae than in Poaceae. This study demonstrated that Dendranthema zawadskii var. latilobum (Maxim.) Kitam. is the most tolerant species and that a relationship exists between the salt tolerance of percent germination and the mean germination time in the leaves.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.353-360
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• 2009

Phosphorus (P) is one of the essential elements of the phospholipids that are involved in the formation of plant cell membranes. Phosphorus is highly immobile in soils and is often a limiting nutrient for plant growth. Phosphorus mobility and availability varies with several factors such as application frequency, placement in the soil, and the amount of irrigation or precipitation. This study was conducted to evaluate the effect of P applications at level of 0, 146, and 293 $kg{\cdot}ha^{-1}$ at four mixing depths (0, 7.6, 15.2, and 22.9 cm )on the growth and establishment of Kentucky bluegrass (Poapratensis L.) in a sand-based system.Grass clipping samples were collectedevery two weeks, dried, and weighed. Total root dry weight, root organic matter, and tissue content of P were measured at the end of the study. Leachate was collected weekly and analyzed for total P concentration. No difference was found between application of P to the surface and to the 7.6 cm mixing depth. However, surface application with 146 and 293 kg $P{\cdot}ha^{-1}$ produced 8-10% and 16-20% more P in tissue than subsurface applications, respectively.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.131-135
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• 1999

The objective of this research was to improve moisture retention capacity of pine bark. To achieve this, barks were ground with Wiley mill of hammer mill and were blended with recycled rockwool. Then, changes of soil physical properties were determined. The percentage of particles larger than 5.6 mm was 86.5% in raw materials. The percentage of particles larger than 1 mm decreased and those of particles smaller than 1 mm increased by grinding with Wiley mill or hammer mill. Grinding with Wiley mill showed better effect than those of hammer mill in decreasing particle size distribution. Grinding resulted in decreased total porosity (TP) and air space (AS) and increased container capacity (CC) and residual water content (RW), indication improved moisture retention capacity. The material ground with Wiley mill, than blended with 50% recycled rockwool had 81.1%, 67.7%, 13.5% and 235 ml in TP, CC, AS and RW, respectively. These results indicated that moisture retention capacity was improved by blending with recycled rockwood, but aeration of root media was much better than those of peat+vermiculite(1:1, v/v), which is commonly used in commercial production.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.1-5
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• 1978

The effect of phosphorus and potassium on the leaf yielding from the mulberry field was surveyed, designing four application levels of potassium and phosphorus respectively; Po, P$^1$/$_2$ and P$_1$and P$_2$ for phosphorus, K$^1$/$_3$, K$^2$/$_3$, K$_1$and K$_2$for potassium after amount of nitrogen was constant at 25kg/l0a. The standard application of three elements is at 25-11-15kg/l0a. No application only showed significance among the treatments in the 3rd year autumn. However there is no significance, ever decreasing 2.7∼5.9% of leaf yielding in application of potassium and 6.4∼11.5% of leaf yielding in application of phosphorus. There is also no increase of leaf yielding even with application of double quantity of phosphorus and potassium. Potassium in soil was considerably fluctuated, while fluctuation of phosphorus is very low. With these results, it was evident that the conventional application level for phosphorus (11kg/l0a) is reasonable and for potassium may be cut down to 5∼10kg/l0a without showing any significance for the successive three years.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.187-194
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• 2019

Intake ratio from river constitutes about 31% (8/26) that beings to "water stress country" as "Medium ~ High" with China, India, Italy, South Africa, etc. Therefore, the present study on a dam that is the most effective and direct for securing water resources has been performed. First of all, climate change scenarios were investigated and analyzed. RCP 4.5 and 8.5 with 12.5 km grid resolution presented in the IPCC (Intergovernmental Panel on Climate Change) 5th Assessment Report (AR5) were applied to study watershed using SWAT (Soil and Water Assessment Tool) and HEC-ResSim models that carried out co-operation. Based on the results of dam simulation, the reduction effects of floods and droughts were quantitatively presented. The procedures of dam projects of the USA, Japan and Korea were investigated. As a result, there are no estimating quantitative criteria, calculating methods or formulas. In the present study, therefore, indexes for selecting suitable dam site through literature investigation and analyzing dam watersheds were determined, Expert questionnaire for various indexes were performed. Based on the above mentioned investigation and expert questionnaire, a methodology assigning weight using AHP method were proposed. The function of suitable dam (FSDS) site was calibrated and verified for four medium-sized watersheds. Finally, automated model for suitable dam site was developed using FSDS and 'Model builder' of GIS tool.