• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.5
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• pp.44-48
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• 2013

Ultrasonic treatment of KOCC was tried to explore the possibility for improvement of KOCC quality as a raw material for making industrial packaging paper and paperboard. The effect of pH, stock consistencies and treatment times on the ultrasonic response of KOCC were investigated. WRV, apparent density, tensile index and burst index were improved as pH of KOCC slurry is increased. However highest tear index and stiffness were obtained at pH 8. It was also found that the highest WRV and strength properties could be obtained at 0.5% of KOCC consistency during ultrasonic treatment. WRV and most strength properties were improved with ultrasonic treatment time. It was found that ultrasonic treatment can be used as a useful mean for KOCC modificaton.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.2
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• pp.183-192
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• 2018

Applicability of corrosion inhibitor was evaluated using pilot scale water distribution pipe simulator. Calcium hydroxide was used as corrosion inhibitor and the corrosion indices of the water were investigated. Corrosion indices, Langelier saturation index (LI) increased by 0.8 and calcium carbonate precipitation potential (CCPP) increased by 9.8 mg/L. This indicated that corrosivity of water decreased by corrosion inhibitor and the effects lasted for 18 days. Optimum calcium hydroxide dose was found to be 3~5 mg/L for corrosion inhibition. We suggest that monitoring of CCPP as well as LI need to be conducted to control corrosivity of water.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.4
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• pp.518-528
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• 2006

The air quality index (AQI) is an index for reporting daily or hourly air quality to the general public. The AQI focuses on health effects that can happen within a few hours or days after breathing polluted air. Many countries have their own AQI reporting systems, and the HAEI (hourly air environment index) method is now being used in Korea. In this study, in order to compare the AQI results from different methods, we applied three methods. i.e. US AQI, Canadian AQI, and Korean HAEI, to the same air quality data-base. The data-base was constructed from 10 monitoring sites in Gyeong-buk province for the last four years since 2000. Based on the results, a critical evaluation of the Korean HAEI method was made, and a number of suggestions and recommendations were presented to improve the AQI reporting system in Korea.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.779-787
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• 2021

This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.25-33
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• 2016

This paper describes three-dimensional computational fluid dynamics (CFD) simulation of liquid-liquid flow and transient tracer tests in a full-scale continuous stirred-tank reactor (CSTR) used for drinking water treatment. To evaluate the effects of inlet flow rate on hydrodynamic behavior in the selected CSTR, inlet flow rate was changed from 10% to 100% of the design flow rate. From the results of CFD simulation and analysis, as the inlet flow rate increases, Modal index and ${\beta}$ value are increased. Also, Morrill index shows local minimal points in relation to the inlet flow rate, which are observed at 20% and 40% of the design flow. As inlet flow Increases more than 40%, it is shown that Morrill index re-increases to close to ideal CSTR.

• Journal of Environmental Impact Assessment
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• v.21 no.4
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• pp.509-523
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• 2012

This basic study is to present the methods and raw data for carrying out to objectively assess an ecosystem by developing the plant ecological indices. The results are as follows. The plant ecological indices were 7 units including RI (Rare Index), EI (Endemic Index), SI (Specific Index), NI (Naturalized Index), UI (Urbanized Index), Pte-Q (Pteridophyta Index) and HI (Halophytes Index). The vascular plants in Mt. Waryong, Mt. Bongmyeong and Bito island were summarized as 471 taxa including 104 families, 294 genera, 419 species, 3 subspecies, 41 varieties and 8 forms. We surveyed 5 taxa of rare plants, 7 taxa of endemic plants, 38 taxa of specific plants by floristic region, 40 taxa of naturalized plants, 1 taxa of invasive alien plant, 19 taxa of pteridophyta and 14 taxa of halophytes. Bito island had the highest RI was 1.2%. Mt. Bongmyeong was 1.4% higher than other sites. If the SI of 2.9% was the highest in Bito island. Bito island was the highest NI, and the UI was the hightest in Mt. Waryong. Mt. Bongmyeong was the lowest NI and UI. In Mt. Waryong and Bito island, the highest DI was 9.1%. The Pte-Q of Mt. Waryong was 1.3 higher than the other sites. Bito island, the highest HI was 8.1%. Overall, 1.5% of RI, 1.9% of EI, 2.3% of SI, 8.5% of NI, 14.3% of UI, 9.1% of DI, 1.0 of Pte-Q and 3.0% were analyzed with HI.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.6
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• pp.63-75
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• 2013

The purpose of the study is investigating the price fluctuation of landscaping plants in the Information on Commodity Prices(ICP) and the posted price fluctuation of landscaping plants of Public Procurement Service(PPS) recent 10 years. It also provides the basic information which can be applied to production and sales of landscaping plants, comparing with general price index. The major findings of the study are as follows. First, The price of investigated plants of PPS has increased about 4.56% in average recent 10 years. Among this increase, of evergreen tree was predominant. On the other hand, landscaping trees price of ICP has increased about only 2.34% in average. Secondly, The result shows that average price of investigated plants of PPS is positively related with the price of ICP. For this reason, we found that prices of ICP and of PPS move together in most case. However, we found that there are no relation between Consumer Price Index(CPI), Producer Price Index(PPI) and Agricultural Price Index(API). Therefore, price fluctuation of landscaping trees moves regardless of normal price fluctuation in general. Third, even though result shows that price index of evergreen trees, deciduous trees and shrubs are weakly related with normal price index partly, it was not high enough to be significant. According to the result, we found that price of landscaping plants is not related with market situation. For this reason, we thought that there are some difficulties for the reasonable production and sales of landscaping plants because the price is somewhat decided by rule of thumb. Therefore, understanding the composition of cost and making prediction by price fluctuation available are needed so that it can be practically conducive to reasonable production and sales.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.165-170
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• 2011

Recently natural disasters such as the frequency and intensity of drought have been increasing as a result of climate change. This study suggests a drought index, WADI (Water Availability Drought Index), that considers water availability using 6 components (water intake, groundwater level, agricultural reservoir water level, dam inflow, streamflow, and precipitation) using the Z score and data monitoring on a nationwide level. SPI (Standardized Precipitation Index) was applied in coastal area. For the severe droughts of 2001 spring and 2008 autumn, the index was evaluated by comparison with reported damage areas. suggested to combine The spatial concordance rate of WADI in 2001 and 2008 for estimation of the degree of drought severity was 50 % and 24 % compared to the actual recorded data respectively.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.610-618
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• 2015

This study was conducted to find out the influence of sample size (accumulated survey areas) on the seven biological indices of benthic macroinvertebrates. BMI, the index similar to Zeilika-Marvan’s saprobic index, tended to be independent on the variations of sample size. The other indices (Shannon-Weaver’s diversity, Margalef’s richness, Menhinick’s richness, Pielou’s evenness, and Lenat’s EPT index) showed the considerable variations along with the increase of sample size and environmental conditions. To get the appropriate index values, it should be sampled at least 6 replicates more based on 30×30cm Surber sampler. In addition, the habitat heterogeneity index of benthic macroinvertebrates suggested in this study, it will be able to be used for evaluating the heterogeneity of habitats.

• Computers and Concrete
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• v.21 no.6
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• pp.741-748
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• 2018

In this paper, the sensitivity of a plastic-damage-based structural damage index on mesh density is studied. Multiple finite element meshes with increasing density are used to investigate their effect on the damage index values calculated from nonlinear finite element simulations for a reinforced concrete column subjected to cyclic loading. With the simulation results, this paper suggests a correction method for the objective damage index based on nonlinear regression of volumetric tensile damage ratio data. The modified damage index values are presented in the quasi-static cyclic simulation to show the efficacy of the suggested correction method.