• Journal of Plant Biology
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• v.33 no.4
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• pp.243-251
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• 1990

Polyamine titers and the activities of arginine decarboxylase(ADC) and ornithine decarboxylase (ODC), enzymes which catalyze rate-limiting steps in polyamine biosynthesis, were investigated during polar regeneration of Populus leaf segments. The polar regeneration occurred at the basal cut end of Populus leaf segments through cell division around the vascular bundle. In the process of polar regeneration, the titers of putrescine and spermidine increased rapidly but the content of spermine remained constant. The leaf segments were then divided into three separte part ; the proximal, middle and distal. Spermidine titers showed an increase mainly in the proximal parts where polar regeneration occurred. On the other hand, putrescine titers showed an increase in the other two parts. In the course of polar regeneration, the activities of ADC and ODC increased, the ADC activities being higher than those of ODC. However, ODC activity was higher in the proximal part. Therefore, the spermidine contents and ODC activities are suggested to be related to polar regeneration in Populus leaf segments.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.133-139
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• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filed by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• The Korean Journal of Ecology
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• v.25 no.4
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• pp.267-273
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• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filled by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1447-1450
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• 1999

Countercurrent oxygen reaction (COR) was developed and evaluated for regeneration of exhausted activated carbon. Whether the regeneration technique is feasible or not is affected strongly by gradual loss and physical changes of activated carbon, energy consumption, and effective removal of adsorbed materials during the process. Various parameters such as reaction temperature, the loss of activated carbon, surface area, pore volume, surface structure, adsorptive property, etc. were examined to determine the effectiveness of COR. The results of these tests showed that the parameters were strongly dependent on oxidant flow rate, and suggest that the newly developed COR is comparable and, in some ways, possibly superior to conventional regeneration techniques because the overall process runs in a single step and is less energy intensive, and also because the adsorptive capacity of exhausted activated carbon was completely recovered.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.764-768
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• 2011

The process of $CO_2$ capture using aqueous Monoethanolamine(MEA) has been considered as one of the leading technologies for intermediate-term strategy to reduce the $CO_2$ emission. This MEA process, however, consumes relatively a large amount of energy in the stripper for absorbent regeneration. For this reason, various process alternatives are recently established to reduce the regeneration energy. This paper suggests a flue gas split configuration as one of MEA process alternatives and then simulates this process using commercial simulator. This flue gas splitting has an effect on reducing the temperature of the lower section of absorber as well as decreasing the absorbent flow rate. Compared to the base model, this optimized flue gas split process provides 6.4% reduction of solvent flow rate and 5.8% reduction of absorbent regeneration energy.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.247-251
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• 2008

There are many stakeholder whose interests against the rest and lots of complex projects in Urban Regeneration. Moreover, there are various communication routes and complex decision making structure because the benefits among stakeholder are conflict. Eventually, the lots of decision making task and complex structure cause inefficiency and delay of Urban Regeneration business. This Is a basic study for establishing decision making governance which help efficient decision making in Urban Regeneration. This study was conducted follow process. Through the analysis the Urban Regeneration process and literature study of "Governance", we characterize the decision making of Urban Regeneration, and based on that character we founded "decision making governance composition". Finally we suggest the "Decision Making Governance System Concept in Urban Regeneration"

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.115-123
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• 2017

The purpose of this study was to develop an indicator for the selection of urban regeneration areas through an analytical network process. Therefore, this study derived five criteria and 58 indicators based on previous studies. Five criteria and 16 indicators were derived by taking into account the region and city characteristics of Gong-ju. Next, a survey from 63 urban regeneration experts was performed. The weight values of the criteria were calculated using the super decisions 2.0 program. As a result, population characteristics (0.244) was the most important criteria, followed by the industry economy (0.218), condition of promotion policy (0.193), social culture (0.188), and physical environment (0.158). These results will be used to select potential urban regeneration areas, and will contribute to overall effective urban regeneration.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.661-665
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• 2004

As the concentration of ammonium nitrogen could be reached 2～3 mg/L in the winter in the river. It was clear that the excessive concentration of chlorinated organics could be produced with the increase of chlorine addition to remove ammonium nitrogen. In the innovative ammonium nitrogen removal process, zeolite adsorption is very efficient as substitute for rapid sand filtration without other adverse quality change in the water. This study is conducted to evaluate the feasibility of ammonium nitrogen removal and regeneration by zeolite adsorption in drinking water treatment. Also, the reuse possibility of zeolite is evaluated to change the removal efficiency of ammonium nitrogen through several times of regeneration. The ammonium nitrogen was not removed in sand filter, but it was almost removed in zeolite filter during 7 days. The sand and zeolite filters have a similar result of turbidity removal. Therefore, zeolite filtration was confirmed the removal of turbidity and ammonium nitrogen as a media. When compared KCl with NaCl as a chemical for zeolite regeneration, it is demonstrated that KCl was more efficient than NaCl in the ability of zeolite regeneration. The adsorption rate of ammonium nitrogen was almost not decreased in the results of several times of regeneration. It is indicated that both zeolite and regeneration solution were possible to reuse without variation of regeneration rate through this study.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.309-309
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• 2000

The main objective of this study is to understand the regeneration step of the PTSA(Pressure and thermal swing adsorption) process below the atmospheric pressure by rigorous dynamic simulation. This target process is to recover toluene using activated carbon as an adsorbent. To do this, the dynamic simulations for the regeneration step are performed at 360, 490, 590mmHg and at high temperature after the simulation of the adsorption step at latm and 298K. A mathematical model was developed to simulate the column dynamics of the adsorption systems. This model is based on non-equilibrium, non-isothermal and non-adiabatic conditions, and axial dispersion and heat conduction are also considered. Heat transfer resistances are considered in gas-solid, gas-column wall and column wall-outside air. The LDF(Linear Driving Force) approximation model describes the mass transfer rate between the gas and solid phase. This study shows that the recovery of toluene by PTSA is more preferable than that by general TSA.

• Architectural research
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• v.11 no.2
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• pp.35-42
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• 2009

Recently, intensive urban redevelopment concentrated on new towns has reduced the number of settled population, and weakened various functions such as commercial, culture, education and welfare in old towns, and made the stagnation and declination of the entire or some parts of old towns. Urban regeneration project means renewing cities' functions in terms of physical, environmental, social, cultural, industrial and economic aspects or revitalizing the existing functions through improvement project in the entire or part of a city, which is now drawing keen attention from the public. However, urban regeneration project is huge in scale, needs long construction period and various complex facilities, and also characterized by complicated relations with many stakeholders. Due to such characteristics, there are many risks in the project. Therefore, systematic risk management is absolutely necessary to efficiently manage various risk factors inherent in urban regeneration project. The purpose of this research proposes a basic model to establish risk management plan and work process in order to help project participants to perform risk management more systematically and rationally in the development phase of urban regeneration project.