• Journal of Environmental Science International
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• v.32 no.10
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• pp.703-712
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• 2023

Due to sporadic development projects and Korea's geographical characteristics slopes are inevitable. Consequently, widespread slope greening projects are underway, prioritizing safety and landscape integration. Experimental research is being conducted on slope greening methods and their effects; however, there is a dearth of research on the various conditions resulting from slope greening construction defects. This study examined different conditions and assessed greening methods on real-world sites to understand their correlation with slope greening. Even in the same areas, the state of slope greening varied in different conditions. This underscores the importance of pre-evaluating specific conditions to achieve efficient slope greening results across various conditions. Consequently, there is a need for guidelines and institutional frameworks to assess various conditions in future endeavors.

• Journal of the Korean housing association
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• v.16 no.4
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• pp.9-16
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• 2005

The purpose of this study was to suggest the basic material of elderly housing complex development by examining the preferred residential environmental characteristics of the elderly housing complexes according to the situation of old age of the pre-elderly. The study was conducted assuming eight different situations of old age according to health conditions, couple living conditions, and economic conditions. The subject is the pre-elderly who want to live in the elderly housing complexes in the future is unlike other studies, so the result of their preferred residential environmental characteristics would be more concrete and reliable. In general, the preferred residential environmental characteristics of the elderly housing complex change with the situation of old age. This suggests various elderly housing should be considered as the situation of old age develops.

• Environmental Engineering Research
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• v.15 no.3
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• pp.129-134
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• 2010

The optimization of experimental parameters, such as catalyst type, catalyst concentration, molar ratio of alcohol to oil and reaction temperature, on the transesterification for the production of rapeseed methyl ester has been studied. The Taguchi approach (Taguchi method) was adopted as the experimental design methodology, which was adequate for understanding the effects of the control parameters and to optimize the experimental conditions from a limited number of experiments. The optimal experimental conditions obtained from this study were potassium hydroxide as the catalyst, at a concentration of 1.5 wt %, and a reaction temperature of $60^{\circ}C$. According to Taguchi method, the catalyst concentration played the most important role in the yield of rapeseed methyl ester. Finally, the yield of rapeseed methyl ester was improved to 96.7% with the by optimal conditions of the control parameters which were obtained by Taguchi method.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.209-219
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• 2000

A method is developed to evaluate machining process and to determine the optimal machining conditions considering the environmental effects. The method Is based on the evaluation attributes from the general LCA programs and the analysis technique of AHP from HHS. To assist the analysis. the mass models of cutting energy, tools, and fluids are developed. The models may be used for both quantitative prediction of the uses and disposed masses of materials and optimization of the machining conditions. The algorithm with the mass models is applied to the milling process planning. The process to survey the environmental data, calculate the used mass, and evaluate the alternatives is demonstrated. This demonstration illustrates the of the change of process conditions of the decision making.

• Transactions of Materials Processing
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• v.20 no.2
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• pp.173-178
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• 2011

Environmental Stress Cracking(ESC) is one of the most common causes of unexpected brittle failure of thermoplastic polymers. The exposure of polymers to liquid chemicals tends to accelerate the crazing process, initiating crazes at stresses that are much lower than the stress causing crazing in air. In this study, ESC of acrylonitirile butadiene styrene(ABS) was investigated as a function of the molding conditions such as injection velocity, packing pressure, and melt temperature. A constant strain was applied to the injection molded specimens through a 1.26% strain jig and a mixture of toluene and isopropyl alcohol was used as the liquid chemical. In order to examine the effects of the molding conditions on ESC, an experimental design method was adopted and it was found that the injection velocity was the dominant factor. In addition, predictions from numerical analyses were compared with the experimental results. It was found that the residual stress in the injection molded part was associated with the environmental stress cracking resistance (ESCR).

• Environmental Engineering Research
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• v.20 no.1
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• pp.25-32
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• 2015

The growth of the algae strains Neochloris oleabundans, Botryococcus Braunii and Dunaliella sp. under mixotrophic conditions in the presence of different concentrations of crude glycerol was evaluated with the objective of increasing the biomass growth and algal oil content. A high biomass concentration was characteristic of these strains when grown on crude glycerol compared to autotrophic growth, and 5 g/L glycerol yielded the highest biomass concentration for these strains. Mixotrophic conditions improved both the growth of the microalgae and the accumulation of triacylglycerols (TAGs). The maximum amount of TAGs in the algal strains was obtained in the 5 g/L glycerol growth medium. The fatty acid profiles of the oil for the cultures met the necessary requirements and are promising resources for biofuel production.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.181-187
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• 2001

This study was carried out to measure the variations of potential and current density with polymers. The results were particularly examined to identify the influences on potential and rate of various factors including temperature and pH. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum current density were designated as the relative polarization sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.239-244
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• 2004

The purposes of this study were to examine applicability of limestone as a conditioning agent and to determine the optimum conditions for improving dewaterability of digested sludge. The optimum conditions for temp., pH, dosage, particle size, time, and pressure was $30^{\circ}C$, 7, 45 g/l, 100 mesh, 30 min., and $2.66 {\times} 10^4 N/m^2$, respectively. On the basis of induced optimum conditions, if adding limestone in digested sludge, it estimated that its specific resistance was $1.43 {\times} 1012 m/kg$. Therefore, it seemed that we could utilize limestone as conditioning agent for improving dewaterability of digested sludge.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.333-341
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• 2008

In this study, the possibility and the optimal conditions for treating slurry type piggery wastewater using supercritical water oxidation were tested in the laboratory. The results could be summarized as follows; The slurry type piggery wastewater, which was diluted 50 times, was treated most effectively at the pressure of 300 bar, the temperature of $550^{\circ}C$ and the residence time of 10 minutes. The air saturated water was injected, as an oxidizing agent, and the removal efficiencies of $COD_{Cr}$, T-N, $NH_4^+$-N and T-Pattheoptimal conditions were 92, 40, 59 and 100%, respectively. Therefore, analte rnativemea suremu stbetaken to improve theremo valefficiency of the nitrogen compounds.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.287-295
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• 2007

To obtain a design data for box beams used as headers in light-frame timber construction, $2{\times}6\;(38{\times}140mm),\;2{\times}8\;(38{\times}184mm),\;2{\times}10\;(38{\times}235mm)\;and\;2{\times}12\;(38{\times}286mm)$ members were built as box beam specimens for bending tests. The allowable bending stresses for box beams were obtained through bending tests of these specimens, and span tables were calculated for various loading conditions based on the allowable bending stresses obtained. The allowable bending stresses were determined as the bending stresses at 10mm deflection of specimens from the results of bending tests of box beam specimens. Span tables for box beams were obtained assuming five loading conditions for headers used in exterior walls and two loading conditions for headers used in interior walls. Among these 7 loading conditions, 5 loading conditions applied to headers in exterior walls included the dead loads, the live loads and the snow loads and 2 loading conditions applied to headers in interior walls included the dead loads and the live loads.