• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.12-27
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• 2000

During the recent decades, he problem of climate variability and change has been in the forefront of scientific problems. The objective of this study was to assess the impact of climate variability on crop growth and yield. The growth duration was the main impact of climate variability on crop yield. Phyllochronterval was shortened in the global worming situations. A simple model to describe developmental traits was provided from heading data of directly seeded rice cultivars and temperature data. Daily mean development rate could be explained by the average temperature during the growth stage. Simple regression equation between daily mean development rate(x) and the average temperature(y) during the growth period as y = ax + b. It can be simply modified as x = 1/a $\ast$ (y-b). The parameters of the model could depict the thermo sensitivity of the cultivars. On the base of this model, the three doubled CO2 GCM scenarios were assessed. The average of these would suggest a decline in rice production of about 11% if we maintained the current cultivars. Future cultivar's developmental traits could be suggested by the two model parameters.

• Journal of the Korean Society of Combustion
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• v.18 no.4
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• pp.1-11
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• 2013

The oxy-fuel combustion is $CO_2$ capture technology that uses mixture of pure $O_2$ and recirculated exhaust as oxidizer. Currently some Oxy-fuel power plants demonstration project is underway in worldwide. Meanwhile research project for converting 125 MWe Young-Dong power plant to 100 MWe oxy-fuel power plants is progress. In this paper, 1 D process analytical approach was applied for conducting process design and operating parameters sensitivity analysis for oxy-fuel combustion of Young-Dong power plant. As a result, appropriate gas recirculation rates was 74.3% that in order to maintain normal rating superheater, reheater steam temperature and boiler heat transfer patterns. And boiler efficiency 85.0%, CPU inlet $CO_2$ mole concentration 71.34% was predicted for retrofitted boiler. The oxygen concentration in the secondary recycle gas is predicted as 27.1%. Meanwhile the oxygen concentration 22.4% and moisture concentration 5.3% predicted for primary recycle gas. As the primary and secondary gas recirculation increases, then heat absorption of the reheater is tends to increases whereas superheater side is decreased, and also the efficiency is tends to decrease, according to results of sensitivity analysis for operating parameters. In addition, the ambient air ingression have a tendency to lead to decline of efficiency for boiler as well as decline of $CO_2$ purity of CPU inlet.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.377-401
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• 2016

To study the effect of titanium dioxide ($TiO_2$) nanoparticles on membrane performance and structure and to explore possible improvement of using mixed solvents in the casting solution, composite polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared via immersion precipitation method using a mixture of two solvents triethyl phosphate (TEP) and dimethylacetamide (DMAc) and addition of $TiO_2$ nanoparticles. Properties of the neat and composite membranes were characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and contact angle and membrane porosity measurements. The neat and composite membranes were further investigated in terms of BSA rejection and flux decline in cross flow filtration experiments. Following hydrophilicity improvement of the PVDF membrane by addition of 0.25 wt.% $TiO_2$, (from $70.53^{\circ}$ to $60.5^{\circ}$) degree of flux decline due to irreversible fouling resistance of the composite membrane reduced significantly and the flux recovery ratio (FRR) of 96.85% was obtained. The results showed that using mixed solvents (DMAc/TEP) with lower content of $TiO_2$ nanoparticles (0.25 wt.%) affected the sedimentation rate of nanoparticles and consequently the distribution of nanoparticles in the casting solution and membrane formation which influenced the properties of the ultimate composite membranes.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1316-1323
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• 1999

Extensive emphasis on milk and milk fat yields with no diversion for beef performance increased the yield efficiency of North American dairy cattle. Heavy demand for North American genetics followed national strain comparison trials in Poland, and US and Canadian dairy cattle and germplasm still are an important source of genetics for many countries. Genetic improvement has accelerated in many countries because of the implementation of sampling programs for young bulls and improved evaluation procedures. Rapid access to information and more frequent calculation of genetic information also are having a positive impact on genetic improvement. Traits other than yield should be considered in a breeding program, but those traits mist have a reasonable opportunity for improvement and sufficient economic worth. Because of ever increasing efficiency, the world's milk supply comes from fewer cows each year. However, no decline in the rate of genetic improvement is apparent under current genetic practices; estimates of heritability are increasing, and a decline in yield efficiency is unlikely in the near future. As management improves, especially for subtropical conditions, many of the selection principles used in temperate climates will be adopted for more adverse environmental conditions.

• Journal of Distribution Science
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• v.18 no.1
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• pp.5-13
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• 2020

Purpose: The purpose of this study is to examine the growth and change process of Korean cosmetic market that has grown more than three times since 2000. It also examined how the growth and decline of the cosmetics brands are related to the change of the cosmetic distribution structure. Research methodology: This study tried to classify the change of the Korean cosmetics market into four stages based on the market sales information. It analyzed the sales information of Korean cosmetic companies and the relationship with the sales of the brands by distribution channel. Results: One-brand store channel had played a leading role in the market growth, and multi-brand stores have grown and a number of brands also grew through that channel since 2013. Since 2016, multi-brand stores have continued to grow and have dominated the market beyond one-brand store channel. Conclusions: The changes in sales of domestic cosmetics companies have been classified based on the distribution channel type in four stages: the emergence of one-brand store, the growth of one-brand store channel, the growth of multi-brand store channel, and the decline of one-brand store channel. In conclusion, multi-brand store channels have recently grown in the Korean cosmetics market, and this trend is expected to continue.

• Journal of Distribution Science
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• v.11 no.2
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• pp.5-10
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• 2013

Purpose - The current research examines the effect of life cycle stages on capital structure of listed companies in Tehran Stock Exchange. Research design, data, methodology - By aid of 685 year-company data, which collected from financial statements of companies during 2006-2012, first, the companies, are classified into three groups including companies in growth, maturity and decline stages. After removing the companies, which were not in accordance with life cycle model, 86 companies were selected to test two main hypotheses of the research. Results - The results show that the capital structure of the sample companies is different in various life cycle stages. More investigation by LSD test also revealed that the total debt to total assets ratio means of the companies in growth stages were significantly different from those companies in maturity stages and those in growth stages had high level of debt to assets ratio. Conclusions - The result showed the average amount of the working capital for companies in three stages are significantly different and due to high level of operation of the companies in maturity and decline stages, these companies held high amount of working capital than those in the growth stages.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.3
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• pp.27-35
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• 2018

This study investigated the public use of Myeon Location in Jeollanam - do where the population is at risk of declining. And discussed the rational provision and coordination of public facilities as a guarantee of fundamental rights. As a result of the study, the rational supply and adjustment directions of public facilities are as follows. First, there are problems such as high availability of management, finance, shopping, and health facilities, lack of culture, leisure, community facilities, and weakening of center function. Therefore, in the continuing declining population situation, face management, safety and health facilities should be upgraded to multifunctional facilities, and utilization efficiency and integration should be promoted. In addition, town center rehabilitation should be centered on multifunctional facilities. In addition, elementary schools will have to utilize and preserve them to take advantage of local cultural values as nostalgia storing place that provide incentives for young people and elementary school children in the future. Second, in order to cope with population decline, public facilities need to strengthen public services through complexity and multifunctionality, wide-area operation with neighboring areas, and user-centered operation management.

• Membrane and Water Treatment
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• v.3 no.3
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• pp.141-149
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• 2012

The aeration provided in a Submerged Membrane Bioreactor (SMBR) improves membrane filtration by creating turbulence on the membrane surface and reducing membrane resistance. However, conventional hollow fiber membrane modules are generally packed in a vertical orientation which limits membrane scouring efficiency, especially when aeration is provided in the axial direction. In the present research, 3 innovative hollow-fiber membrane modules, each with a different membrane orientation, were developed to improve membrane scouring efficiency and enhance permeate flux. Pilot testing was performed to investigate the permeate flux versus time relationship over a 7-day period under different intermittent modes. The results indicated that the best module experienced an overall permeate flux decline of 3.3% after 7 days; the other two modules declined by 13.3% and 18.3%. The lower percentage of permeate flux decline indicated that permeate productivity could be sustained for a longer period of time. As a result, the operational costs associated with membrane cleaning and membrane replacement could be reduced over the lifespan of the module.

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.354-359
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• 2020

Background: The recent, decline in Black-berry Magnolia Vine (Schisandra repanda; BMV) native to Jeju Island, Korea, has raised concerns about the causes of this decline. We investigated the native environment of S. repanda and evaluated its propagation through cuttings to provide preliminary data for its restoration in Jeju Island. Methods and Results: The native environment of the BMV in the Hallasan National Park was surveyed and the climatic variables (temperature and humidity) were analyzed. The effects of the sex of the donor plant (male/female) type of cutting (softwood/hardwood), and treatment with a plant growth regulator (indole-3-butylic acid/rootone) on the rooting of BMV were investigated. Additinallly, the rooting rate, root count, and root length, as well as temperature and humidity were measured in the vinyl moist chambers. BMV was observed in 63 plants distributed from 567 m to 1,364 m above sea level of the Hallasan National Park. In the cutting experiment, the rooting rate was 71.9%, and it was higer in female plants (75.0%) than in male plants (68.8%). Conclusions: The mass propagation of BMV through cuttings valuable for its restoration as without such safeguard measures, the population could face extinction within a few decades.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.157-164
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• 2013

This study analyzed how job stress of counselors at Multicultural Family Support Center effects on their psychological exhaustion. The purpose of this research is on suggesting efficient human resource administration plan by mitigating job stress using the result of analysis. In the result of analysis, MFSC counselors' job stress had an effect on emotional exhaustion, impersonalization, and a factor of decline in sense of self-perfection. Applying this result, this research proposed a necessity of realistic plan preparation to prevent job stress and psychological exhaustion of MFSC counselors.