• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.277-286
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• 2002

An increase in the overall biological effect under the combined action of ionizing radiation with another inactivating agent can be explained in two ways. One is the supposition that synergism may attribute to a reduced cellular capacity of damn-ge repair after the combined action. The other is the hypothesis that synergism may be related to an additional lethal or potentially lethal damage that arises from the interaction of sublesions induced by both agents. These sublesions ave considered to be in-effective when each agent is applied separately. Based on this hypothesis, a simple mathematical model was established. The model can predict the greatest value of the synergistic effect, and the dependence of synergy on the intensity of agents applied, as well. This paper deals with the model validation and the peculiarity of simultaneous action of various factors with radiation on biological systems such as bacteriophage, bacterial spores, yeast and mammalian cells. The common rules of the synergism aye as follows. (1) For any constant rate of exposure, the synergy can be observed only within a certain temperature range. The temperature range which synergistically increases the effects of radiation is shifted to the lower temperature fer thermosensitive objects. Inside this range, there is a specific temperature that maximizes the synergistic effect. (2) A decrease in the exposure rate results in a decrease of this specific temperature to achieve the greatest synergy and vice versa. For a constant temperature at which the irradiation occurs, synergy can be observed within a certain dose rate range. Inside this range an optimal intensity of the physical agent may be indicated, which maximizes the synergy. As the exposure temperature reduces, the optimal intensity decreases and vice versa. (3) The recovery rate after combined action is decelerated due to an increased number of irreversible damages. The probability of recovery is independent of the exposure temperature for yeast cells irradiated with ionizing or UV radiation. Chemical inhibitors of cell recovery act through the formation of irreversible damage but not via damaging the recovery process itself.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.411-417
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• 2024

In the event of a disaster, it is essential to establish a disaster recovery plan and disaster recovery system to minimize disruption to major IT infrastructure and provide continuous business services. In the process of building a disaster recovery system, data replication is a key element of data recovery to provide uninterrupted and continuous business services in the event of a disaster. The data replication method can be determined depending on the system configuration environment and disaster recovery goal level. In this paper, we present a method for determining a data replication method suitable for the configuration environment and disaster recovery target level when building a disaster recovery system. In addition, the replication method decision procedure is applied to build a disaster recovery system and analyze the construction results. After establishing the disaster recovery system, a test was conducted to determine whether the service was transferred to the disaster recovery center in a disaster situation and normal service was provided, and the results were analyzed. As a result, it was possible to systematically select the optimal data replication method during the disaster recovery system construction phase. The established disaster recovery system has an RTO of 3.7 hours for service conversion to the disaster recovery center to provide continuous business services, and the disaster recovery level, which was Tier 2, has been improved to the target level within 4 hours of RTO and RPO=0.

• Journal of Korean Physical Therapy Science
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• v.15 no.1
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• pp.21-28
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• 2008

The purposes of this study are to quantify energy expenditure by measuring oxygen consumption while performing occupational therapy activities most commonly used for adult hemiplegia patients, to recommend a optimal dosage of exercise by comparing energy expenditure according to the recovery stage, and to suggest a precaution in the treatment of patients with cardiac disorders. According to Brunnstrom recovery stages in hand function, subjects were allocated to group I(3rd and 4th Brunnstrom recovery stages) and group II(5th and 6th Brunnstrom recovery stages). Outcome measures included oxygen consumption, energy expenditure rate, and heart rate during each activity and in recovery period after the activity. Occupational activities including sanding activity, putty activity, and skateboard activity were carried out for all patients. In sanding and putty activities, there were significant differences of oxygen consumption and energy expenditure during the activity between groupⅠandⅡ(p<0.05), but there were not significant differences of oxygen consumption, energy expenditure and heart rate in the recovery period(p>0.05). In skateboard activity, there were no significant differences in oxygen consumption, energy expenditure and heart rates between the two groups during the activity and in the recovery period(p>0.05). The findings indicates that cardiovascular demands for basic activities usually peformed for a treatment may be depended on the physical recovery of patients with hemiplegia. Therefore, therapeutic activities for patients should be selected with the great care.

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.225-231
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• 1996

The production of recombinant proteins in Escherichia coli often leads to the formation of an intracellular inclusion body. Key process steps that can determine the economics of large-scale protein production from inclusion bodies are fermentation, inclusion body recovery, and protein refolding. Compared with protein refolding and fermentation, inclusion body recovery has received scant research attention. Nevertheless, it can control the final product yield and hence process cost for some products. Optimal separation of inclusion bodies and cell debris can also aid subsequent operations by removing contaminant particulates that foul chromatographic resins and contain antigenic pyrogens. In this review, the properties of inclusion bodies and cellular debris are therefore examined. Attempts to optimise the centrifugal separation of inclusion bodies and debris are also discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.99-110
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• 2004

In order to investigate the performance of carbon dioxide PSA over zeolite adsorbent, the present study showed results of isotherm measurement, cyclic operation of 3-bed apparatus, and the corresponding numerical simulation. The experiment data of bed temperature, purity, recovery were matched well with that of numerical simulation. Purity of both gas and adsorbent phase increased rapidly with rinse rate but the degree of increase was retarded for large rinse rate The total amount of adsorbed increased only 10% even if rinse rate was enlarged to 4 times. Optimal rinse rate was 7N㎥/hr in this study. The heating rinse led to augments in recovery and productivity, possibly thanks to ease of description resulting from increased volumetric rinse rate and temperature rise in the column.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.447-450
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• 2006

Hydrogen separation from multi-component mixture gases by the four-bed PSA process was studied experimentally and theoretically using layered bed of activated carbon and zeolited 5A. Effects of the adsorption time, the linear velocity on the process performance were investigated. The adsorption time and linear velocity affected the purity and recovery of the product $H_2$ purity is increases according as the adsorption time and linear velocity decrease; however, $H_2$ recovery shows an opposite phenomena to the purity. PSA process simulation studied to find optimum operation condition. In the results, 50sec adsorption time, 3cm/s linear velocity might be optimal values to obtain more than 99.999% purity and 65% recovery hydrogen.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.440-449
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• 2013

We consider a reverse supply chain with a production facility and a recovery facility, and address the joint control of production and disposal decisions for sustainable operations. Demands are satisfied from on-hand inventory of serviceable products, replenished via manufacturing or remanufacturing. Sold products may be returned after usage and each returned product is disposed of or accepted for recovery. Accepted returned products are converted into serviceable products after remanufacturing process. Formulating the model as a Markov decision process, we characterized the structure of the optimal production and disposal policy as two monotone switching curves under a special condition. Three types of heuristic policies are presented and their performance is numerically compared.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.123-128
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• 2000

The ocean is now increasingly suffering from pollution mainly caused by oil spill accidents roil increasing marine transportation. It cause not only the deterioration of ocean resources but also critical damage on the ocean ecosystem. Present study is an experimental one for the development of the oil skimmer which can collect spilled-oil actively and effectively from the sea surface. As an effort of achieving it, a new type of water wheel attached nil skimmer was devised, based upon the concept of orifice. The shapes of the water wheel, blades and oil storing tank are found to be very important factors on the oil skimming performance through systematic experimental analysis. Real oil recovery test was also carried out in square tank using the oil skimmer with their optimal shapes. Quite satisfactory result are obtained from the test which showed 99% and 98% recovery rates for light oil and heavy oil in still water condition, respectively.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.81-86
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• 2003

The study was carried out to evaluate the new analytical method of phthalate esters(diethylphthalate, di-n-butylphthalate, butylbenzylphthalate, bis(2-ethylhexyl)phthalate), one of the endocrine disruptors, which were performed by GC/MS-SIM(selected ion monitoring). The phthalate esters were extracted from water samples using solid-phase extraction on $C_{18}$ columns. It investigated that the extraction recovery rate of phthalate esters with different solvents and solvent volume. The optimal solvent was dichloromethane and proper volume of dichloromethane for recovery of phthalate esters was 4 mL. There were good linearities(above $R^2$=0.9975) in the range 0.01~0.50mg/L, and the detection limits were below 0.01~0.03$\mu\textrm{g}$/L. The recovery rates, RSD and MDLs for phthalate esters were 80~114%, 5.0~8.1% and 0.03~0.11$\mu\textrm{g}$/L, respectively. This method shows a good precision of phthalate esters.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.3
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• pp.240-247
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• 2005

Today's hightech society requires thousands of different products which ultimately result in billions of tons of materials discarded, most of which end up in landfills. Therefore industrial circles could not help thinking about environmental problems by regulations of government or pressures of consumer. Generally, the related research subjects are classified into both of environmentally conscious manufacturing and product recovery, where product recovery aims to minimize the amount of waste sent to landfills by recovering materials and parts from old or outdated products by means of recycling and remanufacturing (including reuse of parts and products). In this research, we constructed a model for remanufacturing various goods using a single facility and developed a dynamic programing(DP) algorithm based upon the optimal solution characterization. We showed the efficiency of the developed DP algorithm with a numerical example.