• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.2
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• pp.39-46
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• 2004

In this paper, the effects of roll diameter and storage time in roll form, bending method and relative humidity on curl in copy paper and inkjet coated papers are investigated. In copy paper, more MD curl is showed at smaller roll diameter and the extension of bending time. However CD curl is hardly influenced by roll diameter and bending time. At high relative humidity, especially CD curl largely reduces. All inkjet coated papers without the primary or the secondary back coating during papermaking show the increase in MD curl and slight decrease in CD curl by MD bending regardless of the winding methods(TSO, TSI). The water spray as back coating results in the remarkable reduction of CD curl regardless of the winding methods. Drying on flat dryer after spraying the moisture on back side display the most excellent effect on the reduction of CD curl.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.358-363
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• 2008

Through this study, 2D multibody dynamics models for analysis of train collisions have been developed to evaluate the crashworthiness requirements of the TSI regulation. The crashworthiness regulation requires some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 kph, and a collision against a standard deformable obstacle of 15 ton at 110 kph. The complete train set will be composed of hybrid model with 2D and 1D model. Using numerical analysis of the hybrid model, some crashworthy design were evaluated in terms of mean crush forces and energy absorptions for main crushable structures and devices. especially, 2D model can evaluate overriding effect in train collisions. It is shown from the simulation results that the suggested hybrid model can easily evaluate the crashworthiness requirements.

• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.483-501
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• 2012

The purpose of this study was to apply a multi-metric model of Lentic Ecosystem Health Assessments(LEHA) for environmental impact assessments of Cheongpyung Reservoir during 2005 - 2006 and assessed the ecological model values. The ecosystem model of LEHA was composed of eleven metrics such as biological parameters($B_p$), physical parameters($P_p$), and chemical parameters($C_p$), and determined the rank of ecological health by the criteria. The variables of $B_p$ were metrics of % sensitive species($M_2$, NMS) and insectivore species($M_5$, % $I_n$), which decrease as the water quality degradates, and these metric values were low as 1.5% and 32.4%, respectively. In contrast, the proportions of tolerant species and omnivore species as the other $B_p$ parameters were 43% and 62%, respectively, which indicate a degradation and disturbance of the ecosystem. Riparian vegetation coverage($M_9$, % $V_c$) as a variable of $P_p$, were higher in the 2nd than 1st survey, and decreased toward the dam site from the headwaters. This was due to a habitat simplification(modifications) by frequent bottom dredging of sand and rocks. The variables of $C_p$ were two metrics of specific conductivity($M_{10}$, $C_I$) as an indicator of ionic contents(cations and anions) and the Trophic State Index(TSI) based on chlorophyll-a($M_{11}$, $TSI_{CHL}$) as an indicator of trophic state. These metric values of $C_p$ had high temporal variations, but low spatial variations on the main axis of the reservoir along with the ecological health of a good condition. The environmental impact assessments using the LEHA multi-metric model indicated that the model values of LEHA averaged 30.7 in 1st survey(fair - poor condition) vs. 28 in 2nd survey(poor condition), indicating a temporal variation of the ecological health. The model values of LEHA showed a minimum(28) in the lacustrine zone(S5) and ranged from 29 to 30 in the other locations sampled, indicating a low longitudinal variation. Overall, environmental impact assessments, based on LEHA model, suggest that chemical water quality conditions were in good, but biological conditions were disturbed due to habitat modifications by frequent dredgings in the system.

• Journal of Distribution Science
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• v.11 no.8
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• pp.31-37
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• 2013

Purpose - This study aims to strengthen the economic cooperation between Korea and Japan by studying the pattern of trade between them and identifying drawbacks. Thus, it aims to enable trade expansion by analyzing the factors that affect trade and identifying ways to improve them. If economic cooperation is improved, transport and communication costs, as well as the transaction cost of economic exchanges, can be minimized. Research design, data, methodology - The trade intensity index developed by the Japanese economist Yamazawa under his trade intensity theory was used to analyze the trade decision factor of Korea and Japan. Trade structure and decision factors were analyzed for the target period of 2000 to 2012, and the period ranging from 2000 to 2005 was compared with the period ranging from 2005 to 2012. This paper is an analysis of the resultant time series. The data were collected from Korea Traders Association, Korea Customs Office, and UN Comtrade (2000, 2005, 2012) and whole table indexes were calculated by the author. Trade related index was used to analyze the comparative advantage based on time-series analysis statistics data (2000. 2005, 2012) through an analysis of the trade intensity index (TII), revealed comparative advantage index (RCA), and trade specialization index (TSI). Results - The trade intensity index of the industries of Japan and Korea is 1.814 in 2000. The export ratio of Japan against China was slightly higher at 2.128. TII is indicated to be 1.600 in both 2005 and 2012, which means export ratio of Japan against China is considerably maintained in 2005; however, export ratio of Japan against China is diminishing gradually as its index is 1.600 in 2012. Second, as per the trade specialization index of the ship industry in Japan and China, TSI is indicated to be -0.818 in 2000, -0.308 in 2005, and -0.847 in 2012. Generally, it is still closer to -1 and especially, we can see it is more closer to -1 in 2012. Third, as per the revealed comparative advantage index of the ship industry in Japan and China, the RCA index in 2012 is 0.007, which is quite far from 1 as compared to the value in 2000 and 2005. Hence, the Japanese ship industry has a significant comparative disadvantage against the Chinese ship industry. Conclusions - Both countries invest most of their capital in the shipping industry. It is the shipping industry that receives the most capital investment in the two countries is invested and governmental policy funds are needed. As both countries have large shipping industries, this research project is very valuable. Japan and China are compared because they are Korea's neighbors. Also, Korea is strategically located in Northeast Asia and has a history of foreign intrusion from several countries. Therefore, the purpose of this research study is to understand the trade structures of both countries and intensify the economic cooperation between Japan and China.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1559-1567
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• 2015

This study investigated the association between $PM_{2.5}$ concentrations obtained with portable real-time monitors and those obtained with gravimetric methods in national urban air-quality monitoring sites in Seoul, South Korea. We used the SidePak AM510 Personal Aerosol Monitor (TSI Inc., 500 Cardigan Road Shoreview, MN) and DustTrak DRX 8533 (TSI Inc., 500 Cardigan Road Shoreview, MN) as portable real-time monitors for measuring $PM_{2.5}$ concentrations and compared these values with those measured with the PMS-103 or SEQ 47/50 models operated by Federal Reference Method (FRM) or the European Committee for Standardization(ECS), respectively, in national urban air-quality monitoring sites in Seoul. Measurements were conducted every other day in the winter and spring seasons of 2014. The estimated daily mean concentrations of $PM_{2.5}$ ranged between 13.4 and $161.9{\mu}g/m^3$ using AM 510 and between 22.0 and $156.0{\mu}g/m^3$ using DustTrak. The Spearman correlation coefficient for $PM_{2.5}$ concentrations between AM 510 and gravimetric results was 0.99, and the correlation between DustTrak and gravimetric results was 0.87. The correction factor suggested was 0.42 and 0.29 for AM 510 and DustTrak, respectively. We found that $PM_{2.5}$ concentrations measured with real-time monitors could overestimate true $PM_{2.5}$ concentrations and therefore the application of a correction factor (0.43) is strongly suggested for quantification when Real-time monitors were operated of $PM_{2.5}$ levels at urban atmospheric environment of South Korea.

• Journal of Gifted/Talented Education
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• v.21 no.3
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• pp.773-796
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• 2011

This study examined the thinking styles of scientifically gifted students on the basis of Sternberg's theory of mental self-government, and the relationship between thinking styles and self-regulated learning ability of the students and their scientific inquiry ability by the different types of thinking styles. 110 middle school students who belonging to the university science-gifted education center participated in this study. 13 thinking styles were postulated that fall along 5 dimensions which are functions, forms, levels, scopes and leanings of the mental self-government. Scientifically gifted students responded to the Thinking Style Inventory (TSI) that standardized Korean version, Self-regulated Ability Inventory and Test of Science Inquiry Skills Inventory (TSIS). The results indicated that scientifically gifted students prefer legislative, liberal, external, hierarchical and judical thinking styles, rather than conservative style. This result also showed that subscales of thinking styles were significantly correlated with self-regulated learning ability and scientific inquiry ability. The legislative style, hierarchical style, local style and liberal style were significant predictors of self-regulation learning ability. The legislative style was significant predictor, whereas oligarchic style was negative predictor of scientific inquiry ability. The results of k-means clustering analysis and MANOVA showed that the self-regulated learning ability and scientific inquiry ability were significantly correlated with the pattern and level of thinking style.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.231-241
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• 2009

Trade specialization index, import market share, unit value index, market comparative advantage index have been applied to compare the competitiveness of forest products in Korean and European markets for the case of Korea-EU FTA. The results say that no items of non-timber products would show a surge of imports as a result of FTA. Timber products, however, such as non-coniferous plywood, continuously shaped wood (non-coniferous), densified wood, wood wool and flour, other (plywood), other (particle board, 441039)), other (fiberboard), oriented strand board (other), other (particle board, 441090), other (particle board, 441031), Prefabricated buildings of wood, fibreboard (of a density exceeding $0.5g/cm^3$ but not exceeding $0.8g/cm^3$), wooden frames (for paintings, photographs, mirrors or similar objects) and wood marquetry and inlaid wood are expected to increase of their imports by eliminating tariffs. For Korean exports no items of non-timber products have competitiveness in European market. For Korean pyroligneous liquid, which is the only competitive timber product in EU market in terms of MCA and TSI, it is difficult to decide whether it has competitiveness, since the actual exports have taken place occasionally during a period of last five years.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2025-2036
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• 2000

A physicochemical process called ultra rapid coagulation(URC) was applied as a pilot scale to recover eutrophicated lake water at Inkyung Lake located on-campus in Inha university. The URC was uniquely designed to completely remove the presence of phosphorus up to 95%, which in turn leading to lessen the level of eutrophication of lake. For a pilot test of period, the lake was restored showing Carlson's Trophic State Index(TSI) of mesotrophic state which accounts for the reduction of total phosphorus and chlorophyll-a down to approximately 55 from 70 and 73, respectively. A residual presence of aluminum and additional coagulants in the effluent was tested for their potential effects on Photobacterium phosphoreum. The effect concentration ($EC_{50}$-15 min) observed in the effluent revealed that the bioactivity of Photobacterium phosphoreum was not influenced by the residual presence of coagulants. After the pilot test of period, the lake was consequently restored as a mesotrophic state in obtaining the second grade of lake water quality. The URC may be further applied for restoration of greater scale of lake in eutrophication.

• Journal of Astronomy and Space Sciences
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• v.24 no.1
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• pp.69-78
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• 2007

The international EARTHSHINE mission is to measure 1% anomaly of the Earth global albedo and total solar irradiance using Amon-Ra instrument around Lagrange point 1. We developed a new ray truing based integrated end-to-end simulation tool that overcomes the shortcomings of the existing end-to-end performance simulation techniques. We then studied the in-orbit radiometric performance of the breadboard Anon-Ra visible channel optical system. The TSI variation and the Earth albedo anomaly, reported elsewhere, were used as the key input variables in the simulation. The output flux at the instrument focal plane confirms that the integrated ray tracing based end-to-end science simulation delivers the correct level of incident power to the Amon-Ra instrument well within the required measurement error budget of better than ${\pm}0.28%$. Using the global angular distribution model (ADM), the incident flux is then used to estimate the Earth global albedo and the TSI variation, confirming the validity of the primary science cases at the L1 halo orbit. These results imply that the integrated end-to-end ray tracing technique, reported here, can serve as an effective and powerful building block of the on-line science analysis tool in support of the international EARTHSHINE mission currently being developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6943-6951
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• 2014

The trophic state assessment of the Hwoiya reservoir was estimated using the Trophic state indices (TSIs) of Carlson and Aizaki using the transparency and concentrations of chlorophyll-a and total phosphorus obtained from two sites of the reservoir. The TSIs assessments showed that eutrophic phenomena occur frequently in the Hwoiya reservoir. In addition, strategies to reduce the phosphorus especially would be prepared because the Hwoiya reservoir exceeded phosphorus-limiting state of 17 < TN/TP (total nitrogen/total phosphorus). Three scenarios for a simulation of the dredging effect of sediments on the water quality using the WASP7 model were made at two sites, which were 10% (scenario 1), 40% (scenario 2) and 60% elution of the pollutants from sediments (scenario 3). In the most elution case (60%), scenario 3, it was considered that 6.4% TN and 9.3% TP at site 1, and 3.9% TN and 5.6% TP at site 2 could be reduced.