• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.45-51
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• 2005

As a silicate source to rice, a coal ash (50%) was mixed with a phosphogypsum (hereafter, gypsum, 50%). Field experiments were carried out to evaluate rice (Oryza sativa) productivity in silt loam (SiL) to which 0, 20, 40 and $60Mg\;ha^{-1}$ of the mixture were added. The mixture increased rice yield and showed the highest yields following the addition of $30Mg\;ha^{-1}$. The mixture did not result in an excessive uptake of heavy metals by the rice grain. The mixture improved available silicate and phosphate and exchangeable calcium contents in soil. The available boron content in soil increased with the mixture application levels up to $1.42mg\;kg^{-1}$ following the application of $60Mg\;ha^{-1}$, but boron toxicity in rice was not found. It is concluded that the coal ash and gypsum mixture could be a good alternative to inorganic soil amendments to restore the soil nutrient balance in paddy soil.

• Korean Journal of Community Nutrition
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• v.14 no.3
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• pp.255-265
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• 2009

This study was investigated nutrient intakes and dietary evaluation index of the healthy subjects over 85 of Sunchang County to explore the improved dietary pattern for healthy aging of the elderly. The survey was conducted by personal interview to 161 elderly subjects (59 males and 102 females over 85) in 2006, and their daily dietary intake was assessed by 24-hr recalls and weighing one meal. The daily energy intakes of males were 1,335 ${\pm}$ 67 kcal, and those of females were 1,095 ${\pm}$ 38 kcal comprised of 66.8% and 68.4% of the EER for the age group of 75. The proportions of energy from carbohydrate : protein : lipid were 70.7 : 14.6 : 14.6 for males and 68.6 : 14.0 : 17.4 for females. The average protein intakes were 95.4% for males and 85.0% for females of RI, and the average calcium intakes were 54.3% for males and 43.6% for females of RI. The daily vitamin intakes were below 70% except vitamin A, vitamin $B_6$, and vitamin E. The proportion of the relative risk groups of protein, phosphate, iron and vitamin A ranged 40-49% of RI over 75 year groups. The other nutrient intakes showed that there were over 50% risk groups. Especially for nutrients such as calcium, vitamin $B_1$, vitamin $B_2$, vitamin C, folate and niacin over 70% of the subjects were under risk. The median value of all nutrient intakes did not reach AI. The INQ of nutrients were over 0.8 except for folate and vitamin C. Calcium intakes were relatively low and needed attention. However, the ratio of calcium and phosphate showed 1 : 1.6, which appeared to be superior to the other districts. The DVS were higher as the dietary balance scores, KDDS were higher, and the groups with high KDDS had high intakes of nutrients compared to the groups with low KDDS. The high risk groups as judged by simple nutrition screening test had lower nutrient intakes than the groups of middle risk or low risk groups. The subjects in Sunchang area had relatively low intakes of several nutrients. However, judging from the desirable patterns of the energy proportion from three major nutrients, ratio of calcium and phosphate and INQ of nutrients there is a possibility that extended healthy aging might be related to the quality of nutrients and relative ratio between nutrients. To improve nutrient status of the elderly of the surveyed area further application involving KDDS and DVS appeared to be required.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.45-50
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• 2005

This study was conducted to measure and understand the exchange of CO₂ and water in a rice canopy. Eddy covariance system was installed on a 10m tower along with other meteorological instruments. CO₂ flux and surface energy balance were measured throughout the whole growing season in 2003 over a typical paddy field in Icheon, Korea. During the early growth stage in May and June, most of net radiation was partitioned to latent heat flux with daytime Bowen ratio of 0.3 to 0.7. Evapotranspiration (i.e., daily integrated latent heat flux) typically ranged from 3 to 4 mm d/sup -1/, with even higher rates on sunny days. Daily integrated net ecosystem exchange (NEE) of CO₂ increased with increasing solar radiation and leaf area index (LAI). The NEE was especially high during the stages of young panicle formation and heading. On 1 June 2003, when the rice field was flooded, it was a weak sink of atmospheric CO₂ with an uptake rate of 9.1 gm/sup -2/d/sup -1/. Despite frequent rainy and cloudy conditions in summer, maximum NEE of 36.2 gm/sup -2/d/sup -1/ occurred on 31 July prior to heading stage. As rice crop senesced after early September, the NEE decreased.

• The Journal of Industrial Distribution & Business
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• v.9 no.5
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• pp.63-72
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• 2018

Purpose - This work analyzes, in detail, the specification of vector error correction model (VECM) and thus examines the relationships and impact among seven economic variables for USA - balance on current account (BCA), index of stock (STOCK), gross domestic product (GDP), housing price indices (HOUSING), a measure of the money supply that includes total currency as well as large time deposits, institutional money market funds, short-term repurchase agreements and other larger liquid assets (M3), real rate of interest (IR_REAL) and household credits (LOAN). In particular, we search for the main explanatory variables that have an effect on stock and real estate market, respectively and investigate the causal and dynamic associations between them. Research design, data, and methodology - We perform the time series vector error correction model to infer the dynamic relationships among seven variables above. This work employs the conventional augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root techniques to test for stationarity among seven variables under consideration, and Johansen cointegration test to specify the order or the number of cointegration relationship. Granger causality test is exploited to inspect for causal relationship and, at the same time, impulse response function and variance decomposition analysis are checked for both short-run and long-run association among the seven variables by EViews 9.0. The underlying model was analyzed by using 108 realizations from Q1 1990 to Q4 2016 for USA. Results - The results show that all the seven variables for USA have one unit root and they are cointegrated with at most five and three cointegrating equation for USA. The vector error correction model expresses a long-run relationship among variables. Both IR_REAL and M3 may influence real estate market, and GDP does stock market in USA. On the other hand, GDP, IR_REAL, M3, STOCK and LOAN may be considered as causal factors to affect real estate market. Conclusions - The findings indicate that both stock market and real estate market can be modelled as vector error correction specification for USA. In addition, we can detect causal relationships among variables and compare dynamic differences between countries in terms of stock market and real estate market.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.70-82
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• 2020

Recently, a lot of damages have been caused by urban flooding, and heavy rainfall that temporarily occur are the main causes of these phenomenons. The damages caused by urban flooding are identified as the change in the water balance in urban areas. To indirectly identify it, this research analyzed the change in the remote sensing indices on each land cover before and after heavy rainfall by utilizing daily precipitation data and multi-temporal Sentinel-2 satellite imagery. Cases of heavy rain advisory and warning were selected based on the daily precipitation data. And statistical fluctuation were compared by acquiring Sentinel-2 satellite images during the corresponding period and producing them as NDVI, NDWI and NDMI images about each land cover with a radius of 1,000 m based on the Seoul Weather Station. As a result of analyzing the maximum value, minimum value, mean and fluctuation of the pixels that were calculated in each remote sensing index image, there was no significant changes in the remote sensing indices in urban areas before and after heavy rainfall.

• International Commerce and Information Review
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• v.19 no.4
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• pp.175-197
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• 2017

As a revision negotiation on the KORUS FTA has become a national pending issue, this study aims to analyze changes in the trade structure of Korean export industry before and after the KORUS FTA. For the analysis, this study used Market Comparative Advantage(MCA) and Intra-industry Trade(IIT) indexes. Results of the analysis are as follows: First, in analyzing the competitive and complementary relationships of export products using the MCA index, it was discovered that Korea has formed an export-oriented complementary relationship with the United States. Second, the results of analysing IIT showed that Korea has made a low-quality vertical IIT with the U.S. in some items while it has usually made a weak IIT with the U.S.. Based on the results above, this study proposes a few policy suggestions in the following areas: Improvement of competitiveness in trade-deficit service sector, achievement of the balance of profit and loss in goods and service sectors through the revision negotiation of the KORUS FTA, enhancement of competitiveness in competitive and comparative disadvantage items, reinforcement of ability to respond to consumption patterns in U.S. market, etc. in export-dominant items, and pursuit of horizontal-vertical division of labor in comparative advantage items and horizontal division of labor in comparative disadvantage items.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.454-460
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• 2012

This study was conducted for determining the influence of Sediment Control Dam dredging on benthic macroinvertebrate communities in mountain stream of Gyeongsangbuk-do. The sediment control dams were surveyed before and after dredging from mountain streams of Yecheon, Yeongju and Bonghwa in Northern part of Gyeongsangbuk-do. Sampling was taken at upper and down from 3 experimental sites and 2 control sites during May to August 2011. The identified species before dredging were 56 belonged to 31 families, 11 orders, 6 classes and 4 phyla, but after dredging it has decreased to 51 species belonged to 27 families, 10 orders, 5 classes and 4 phyla. The microhabitat damage of benthic macroinvertebrates occurred at experimental sites after dredging of sediment control dams led to reduction of the number of species and individuals. Especially, upper stream of experimental sites showed the reduction of an average of 38% species. In general, species diversity indices and species richness indices decreased after dredging; however, dominance indices increased at experimental sites. In the upper stream of experimental sites, the microhabitat damaged and became pool due to dredging. Also, velocity of flow decreased and the river bed became simply due to the sedimentary matter being finer than sand and silt. As a result, composition of functional feeding groups and functional feeding groups were relatively simpler at upper stream and the degree of community differences was greater between upper and down stream. Also, Chironomidae spp., Ephemeridae spp., and Gomphidae spp. to prefer where slow velocity of flow and lentic increased in a greater rate, and the EPT/C index to indicate the balance of the community decreased.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.266-273
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• 2008

The effects of soil acidification on the seedling growth and nutrition of Pinus densiflora and Quercus acutissima were investigated. The relationship between the seedling growth and molar (Ca+Mg+K)/Al ratio of in soil solution was examined. The results suggested that growth inhibition of seedling Pinus densiflora and Quercus acutissima was due to the low pH of soil solution, which was followed by leach of Al into soil solution, and decrease of essential elements, such as Ca in aerial pant of the seeding caused by the increase of Al concentration in subterranean pant of the seedlings. The level of growth inhibition was determined not only by Al concentration, but also by the balance of inorganic elements, Al, Ca, Mg and K. The growths of two species in total dry weight were clearly inhibited when molar (Ca+Mg+K)/Al ratio of the soil was lower than 6.0. The growth in dry weight, in the condition of the molar ratio was 0.8, was decreased 60% or 50% for the seedling of Pinus densiflora or Quercus acutissima respectively. It was concluded that the molar (Ca+Mg+K)/ Al ratio could be an important index for evaluation of the effects of soil acidification, due to acid deposition such as acid rain, on growth of trees and nutrition. And it might be a more useful indicator for evaluation of critical load of acid deposition on forest ecosystems.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.98-105
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• 2018

Objective: This study aimed to assess the effect of pelleted and expanded sorghum-based feeds prepared with different moisture levels and particle size of ingredients on metabolizable energy, ileal digestibility of amino acids and broiler performance. Methods: The experiment was performed with 720 male broiler chicks of the Cobb strain, with treatments of six replications, with 15 birds each; they were arranged in a completely randomized design and $2{\times}2{\times}2$ factorial scheme (pelleted or expanded feed processing, 0.8% or 1.6% moisture addition in the mixer, and particle size of 650 or 850 microns). Results: Higher pellet quality (pellets, % and pellet durability index [PDI]) was obtained in expanded diets and inclusion of 1.6% moisture. The particle size of 850 microns increased the PDI of final diet. All studied treatments had no significant effect on weight gain and broiler carcass and cut yields. Lower feed conversion occurred for birds fed pelleted feed at 42 d. The highest apparent metabolizable energy (AME) and apparent metabolizable energy corrected to zero nitrogen balance (AMEn) values of feed in the initial rearing phase (10 to 13 days) were observed in birds fed pelleted feed or for feed prepared with 1.6% moisture. The highest ileal digestibility coefficients of amino acids were obtained with the consumption of pelleted feed prepared with a particle size of 650 microns and 1.6% moisture. Conclusion: Pelleted feed prepared with a milling particle size of 650 microns and 1.6% moisture provided increased ileal digestibility of amino acids and AMEn in the starter period. However, the expanded feed improved pellet quality and feed conversion of broilers at 42 days of age. We conclude that factors such as moisture, particle size and processing affect the pellet quality, and therefore should be considered when attempting to optimize broiler performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.370-379
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• 2020

This study examined the growth characteristics and competitive advantages of Korea's tourism industry compared to other Northeast Asian countries using the Balassa Indices and Shift-Share method. The analysis results showed that the growth of Korea's tourism industry over the past decade was due mainly to external factors, such as the growth of the global economy and the expansion of the tourism sector, while the role of growth momentum of the tourism industry itself was insignificant. Employment in Korea's tourism industry has shown relatively higher increasing rates compared to the rates of the total amount of sales and value-adding. This appears to be caused by the decreased absorption of the labor force in the tourism industry due to the overall capacity of job creation. (Ed note: This sentence was unclear. Please check the edits.)The competitive advantage of Korea's tourism industry has been strengthened over the past decade, but it is still inferior to other countries. The travel account balance showed that the economic size of the Chinese tourism sector had grown rapidly over the past decade, but the competitive advantage of the sector has been weakened. On the other hand, the economic size of the Japanese tourism sector has shown sluggish growth, while its competitive advantage has been strengthened significantly.