• Korean Journal of Microbiology
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• v.50 no.1
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• pp.40-45
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• 2014

In order to increase the persistence of plant growth promoting rhizobacteria (PGPR) in rhizpsphere soil, the growth of tomato was examined after the application of Arthrobacter woluwensis ED immobilized in alginate bead, which was known as PGPR. When tomato seedlings were treated with A. woluwensis ED of $1{\times}10^6$ cells g $soil^{-1}$ and incubated for 30 days in a plant growth chamber, the shoot length, root length, fresh weight and dry weight of the grown tomato plants treated with the suspended inoculants significantly increased by 36.2, 59, 51.1, and 37.5%, respectively compared to those of the uninoculated control. The treatment of the immobilized bacteria increased those by 42, 67.4, 62.5, and 60.4%, respectively compared to those of the uninoculated control. Therefore, the enhancement of tomato growth by the treatment of the immobilized bacteria was higher than those by the suspended inoculants. The effects of the inoculation on indigenous bacterial community and the fate of the inoculated bacteria were monitored by denaturing gradient gel electrophoresis analysis. The DNA band intensity of A. woluwensis ED in the tomato rhizosphere treated with the suspended inoculants continuously decreased after the inoculation, but the band intensity in the tomato rhizosphere soils treated with the immobilized inoculants showed the maximum at 1 week after inoculation and the decreasing rate was less than that of the suspended inoculants, which indicated the longer maintenance of the immobilized bacteria at rhizosphere soils. Therefore, encapsulation of PGPR in alginate beads may be more effective than liquid inoculant for the plant growth promotion and survival of PGPR at plant rhizosphere.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.41-49
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• 2011

This study is a research based on an existing analysis that peak values of unit hydrograph are variant according to rainfall intensity in a watershed. Differently from the fundamental assumption that an unit hydrograph is time-invariant in a watershed a variant unit hydrograph to rainfall intensity by storms is defined and applied into rainfall events, which produces out runoff hydrograph for an examination. Peak flow and time to peak of unit hydrograph used for an application are obtained from the relation equation with rainfall intensity developed by a previous study reviewed, and its shape is made by Nash unit hydrograph which is determined by the peak values. For the purpose of a comparison an invariant unit hydrograph is defined as Nash model obtained from averaged peak values of unit hydrograph which is derived by 26 rainfall storms. Peak flow and time to peak of flood hydrograph developed respectively by variant unit hydrograph with rainfall intensity and an averaged unit hydrograph are compared to those of the observed hydrograph. With comparing both hydrographs calculated by averaged unit hydrograph and revised unit hydrograph to observed hydrograph it is shown the peak flow and time to peak of hydrograph calculated by time-invariant unit hydrograph revised in this study are closer to those of observed hydrograph than those calculated by averaged unit hydrograph.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.643-654
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• 2018

In order to understand and manage traffic flows in urban areas in the past, a variety of traffic engineering theoretical indicators such as intersection lag and highway speed have been applied. However, these theories and indicators have been developed under the constraints of traffic engineering research before the construction of intelligent transportation system. Since the ATIS system currently exists, it is necessary to introduce a separate traffic engineering technology that utilizes the data. In this paper, it is aimed to confirm whether it is applicable to intermittent flow (approach road, intersection, control group, main road axis) by using 'congestion intensity' which is already used in traffic engineering field. The results of this study are as follows: (1) The traffic signal improvement effect of urban road access road, intersection road, control group, Two verification studies were performed to verify the derived congestion intensity index. (1) verification of congestion intensity threshold value analysis and (2) crossing improvement using the congestion intensity. Through verification, it was confirmed that it is possible to apply the congestion intensity in the inter - city intermittent flow using the 5 - minute unit speed data so as to be able to escape from the existing traffic signal operation management which is past passive and manpower limit.

• Management & Information Systems Review
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• v.38 no.1
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• pp.1-21
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• 2019

This study focuses on (1) the relationship between the network intensity of top managers and the R&D investment of Korean firms, and (2) the moderating effects of the type (related-division vs. unrelated-division) and system (physical division vs. spin-offs) of corporate division on this relationship. The sample of this study was all type and/or system of corporate division implemented by Korean firms during 18-years (1999-2016) study periods. The results of multiple regression analyses as follow. First, as was expected in hypothesis 1 the network intensity of top managers has a strong positive linear relation with the R&D investment of Korean firms. Second, regarding the moderating effect of division type the results show that related-divisions significantly intensify the positive relationship of the network intensity of top managers with the R&D of Korean firms although unrelated-divisions did not. Third, in the analysis of moderating effect of corporate division system the results present the stronger positive moderating effect of spin-offs rather than physical divisions. The findings of the study implies that strong network intensity of top managers can be beneficial to long-term decision such as R&D investment of Korean firms. They accords to network theory that emphasize the importance of strong network effect among top managers based on their trust. The findings also implies that researchers and practitioners should consider organizational-level factors such as organizational structure, culture, corporate governance, etc as well as individual-level factors such as the characteristics and relationships of organizational members when making the decision for firm.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.359-369
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• 2021

In this study, a complex sample logistic regression analysis was performed to identify the factors affecting the activity restriction of 2,701 normal elderly and chronically ill elderly aged 65 and over using raw data from the 8th period of the National Health and Nutrition Examination Survey. It was found that the elderly with chronic disease felt more restricted in their activities than the normal elderly. Activity limiting factors in stroke and hypertension patients are subjective health status, economic level, stress perception, and moderate-intensity work and leisure. The factors limiting activity in patients with heart disease were subjective health status and economic level, and factors limiting activity in patients with joint disease were subjective health status and high-intensity work and leisure. Activity limiting factors for lung disease patients are education level, high intensity work and leisure, and endocrine system activity limiting factors include subjective health status, stress perception, high intensity work and leisure, and activity limiting factors for cancer patients. is subjective health status, stress perception, moderate-intensity work and high-intensity leisure. Rehabilitation programs and policy support are needed for the continuous participation of the elderly with chronic diseases.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2A
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• pp.119-130
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• 2009

Seismic fragility curves of a structure represent the probability of exceeding the prescribed structural damage state for a given various levels of ground motion intensity such as peak ground acceleration (PGA), spectral acceleration ($S_a$) and spectral displacement ($S_d$). So those are very essential to evaluate the structural seismic performance and seismic risk. The purpose of this paper is to develop seismic fragility curves for PSC box girder bridges. In order to construct numerical fragility curve of bridge structure using nonlinear time history analysis, a set of ground motions corresponding to design spectrum are artificially generated. Assuming a lognormal distribution, the fragility curve is estimated by using the methodology proposed by Shinozuka et al. PGA is simple and generally used parameter in fragility curve as ground motion intensity. However, the PGA has not good relationship with the inelastic structural behavior. So, $S_a$ and $S_d$ with more direct relationship for structural damage are used in fragility analysis as more useful intensity measures instead of PGA. The numerical fragility curves based on nonlinear time history analysis are compared with those obtained from simple method suggested in HAZUS program.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.612-613
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.57-58
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• 2006

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.279-280
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.400-401
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• 2012