• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.171-178
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• 2013

In this study, the sludge that occurs in the initial operation of coagulation system developed for the treatment of CSOs were returned to the flocculation reactor. The purposes of this study were to analyze the Characteristics of flocs that are generated through the recycling sludge and settling characteristics of sludge, and to evaluate the possibility that high concentrations of particulate matter in the initial inflow of CSOs could be used as an weighted coagulant additive. As a result, the concentration of treated CSOs pollutants at the beginning of the CSOs influent with a large amount of particulate matter over 20 ${\mu}m$ was low, after gradually increasing the concentrations of them. The flocs generated from the sludge return were similar in size compared to flocs generated through injection of micro sands, and settling velocity in case of return sludge injection was decreased from 55.1 cm/min to 21.5 cm/min. SVI value of the sludge accumulated at the bottom of the sedimentation tank was 72, and settled sludge volume decreased rapidly due to the consolidation of sludge to the time it takes to 10 minutes. these mean that sludge used for recycling has good settling characteristic. A condition of returned sludge which is 0.1% return of 0.3% extraction was formed in the balance of settlement and extraction. In this case, This condition was to be adequate to maintain the proper concentration such as 100~200 mg/L of TS and 50~100 mg/L of VS in the flocculation reactor. The usage of the return sludge containing particulate matters of CSOs as an weighted coagulant additive was able to secure a stable treated water quality despite the change of influent water quality dynamically. Furthermore, it can be expected to reduce the alum dosage along with the sludge production.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.134-147
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• 2019

The purpose of this study was to analyze the functional unit system of NCS landscape field for correction and supplementation of NCS landscape field and the contents of the four-year college landscape course subject. First, 24 unconsolidated four-year universities were selected, and FGI was conducted and verified for 816 courses in 24 universities. The results of the study are summarized as follows, with three sections three, nine divisions and 65 sub-category. First, landscape design subjects accounted for 40.0% of the subjects organized by four-year universities. In addition, the ratio of 12.9% for ecological landscape, 11.3% for landscape construction, 10.2% for others, 10.0% for landscape information, 6.6% for landscape culture and 3.7% for landscape management was surveyed. Balanced and efficient modification and reinforcement of NCS is required in the future. Second, 10(18.9%) units with matching NCS performance criteria and educational objectives were found to be capable of different units(18.9%), 15(28.3%), and 37subjects with inconsistent NCS unit capability (56.9%). Third, looking at the criteria for the reference of each unit of capability presented by the NCS, it is deemed that one unit of capability should be organized separately to improve the practical ability, since it includes the contents of basic knowledge learning. Fourth, the objectives pursued on the basis of the contents of the NCS capability unit and four-year college curriculum were developed by focusing on the development of unit capabilities in the field of landscape construction and landscape management compared to the field of landscape design. It has been shown that a balance is needed for future development. This study is intended to put forward further research that re-examine specific curriculum assessment criteria that have not been classified in the course of classifications based on the curriculum handbook, which excludes interferences from each school.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.701-710
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• 2004

Uncertainty was quantified to evaluate calcium determination result in infant formula with AAS (Atomic Absorption Spectrometry) and ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Uncertainty sources in measurand, such as sample weight, final volume of sample, sample dilution and the instrumental result were identified and used as parameters for combined standard uncertainty based on the GUM (Guide to the expression of uncertainty in measurement) and Draft EURACHEM/CITAC Guide. Uncertainty components of each sources in measurand were identified as resolution, reproducibility and stability of chemical balance, standard material purity, standard material molecular weight, standard solution concentration, standard solution dilution factor, sample dilution factor, calibration curve, recovery, instrumental precision, reproducibility, and stability, Each uncertainty components were evaluated by uncertainty types and included to calculate combined uncertainty. The kinds of uncertainty sources and components in the analytical method by AAS and ICP-AES were same except sample dilution factor for AAS. The analytical results and combined standard uncertainties of calcium content were estimated within the certification range $(367{\pm}20\;mg/100g)$ of CRM (Certified Reference Material) and were not significantly different between method by AAS followed by ashing and method by ICP-AES followed by acid digestion as $359.52{\pm}23.61\;mg/100g\;and\;354.75{\pm}16.16\;mg/100g$, respectively. Identifying uncertainty sources related with precision, repeatability, stability, and maintaining proper instrumental conditions as well as personal proficiency was needed to reduce analytical error.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.32-41
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• 1991

This study is focusted to the national park of Korean typical mountain Chi-ri, its visual resources of forests, and practiced inspectind course by way of hypothesis and tests, to show visual resource management objectively, and that of quantitative basic data. spatial image structure measured by Semantic Differential(S.D.) Scale was shown through factor analysis algorithm for the analyzing psychological amount and examined the flowing out of decisive factor and the objective importance related mutual factors by appling the measurement of visual quality. Also, it has been investigated the differences between the degrees of expectation which is used before and of satisfaction which is used, by appling instrumental expectation theory. And showed patterns of investigation area through factor analyzing algorithm. As a national Park, visual factors that have natural landscape harmonized forest, sky, surface of the water, curious stones and rocks, temples should be escalate their values affirmatively so as to be the scenery of pointed direction and enjoyable, and it is needs the techniques visual resource management and its controlling technique to make artificial structures more intentional planning and systemical setting. Manmade distinctive quality in the spatials that affect complementally or harmonizingly, should be received considering relations between the distifution and joining which in line with various visual presenting massive factors. More than that, it is needed united basic standard to the beauty of arrangements which contain visual continuity considered balance between nature and human work, simplicity of structural types, assimilation, emphasis, unification of different factors and pro rata.

• International Commerce and Information Review
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• v.15 no.4
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• pp.457-479
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• 2013

Through a Chinese rise, Chinese dream is actualizing as the world's great power. According to outlook of World Bank and IMF, Around 2030 China will be a great power bigger than America's economic power. The rise of China will give a huge impact to the whole world. China expands her influence through a global manufacturing base and a global market. To actualize 'Peaceful Rise' Strategy, China has many constraints. Chinese society is facing many difficult social problem due to side effects of a rapid development. Such as the spread of corruption, the severity of wealth gap, environmental degradation and energy shortage. Internationally there are containment from hegemon so-called 'China threat' dispute, Taiwan issue and territorial disputes. Western countries are hostile to China for two reasons. Based on expectations, one is China's socialist system and the other is the rising China which will compete for supremacy with Europe and America. Recent emergence of Chinese nationalism and the containment of the neighboring countries are also serious limiting factors. Domestically they have the rampant corruption in the bureaucracy, weakened capacity of Communist rule, wealth disparity due to the discriminatory economic development strategy, seriousness of rural problem, social instability, lack of social security systems and the development gap between the eastern coastal areas and western inland areas, ethnic minorities problems, the constraint of sustainable development issues due to lack of resources, environmental pollution and energy constraints. Like the former Soviet Union, China may face a dismantlement. After the rise, China may encounter possibilities of a war between great powers or a collapse of Chinese society caused by deepening internal conflict. Serious economic polarization would make peasants and urban workers, who are social vulnerable people, to turn their back to communist party and threaten the justification and the appropriateness of the ruling communist party. Chinese government will think internal system security threat is more formidable risk factor than a system security threat from the hegemon. The decline of great country comes from internal reasons rather than external reasons. To achieve peaceful rise, unification with Taiwan is an essential prerequisite. Taiwan issues are complex problems which equipped with international and domestic factors. Lack of energy resources, environmental pollution in China will bring economic crisis to Korean enterprises. Important influence to Korean economy will be a changeover of the method in economic development. It will turn the balance of investment and consumption, GDP-centered growth to consumption and environment-centered growth. Services industries including finance, environment, culture, education, health care and social welfare will grow. Change in China's growth model will give a great challenge upon the intermediate goods industry in Korea. Korea should reduce the portion of machinery, automotive, semiconductor, steel and chemical-centered export industry to China, and should increase the proportion of the service industry.

• Korean Business Review
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• v.11
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• pp.241-253
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• 1998

One form of the anomalies of stock price changes as reaction to earnings information is believed to be caused by the so-called earnings fixation, which is the overreaction of stock prices to earnings. According to the Sloan (1996) study, stock price changes are positively associated with earnings at the time of earnings releases, but the association becomes negative after that, as the early overreaction is corrected. However, the problem in his study is to use cash flows computed by adjusting earnings with appropriate income statement and balance sheet items. As Bahnson et al. (1996) show, these cash flows substantially deviate from SFAS No. 95 cash flows and the sample used in this study is found to be subject to this substantial measurement error. Therefore, the result of Sloan might be driven by this error and the reexamination of earnings fixation is warranted. The results are generally consistent with those in Sloan. First, earnings is positively associated with stock price changes at the time of earnings releases, but the association becomes negative after that. Second, cash flows show a weak association with stock price changes at the time of earnings releases, but the association become stronger thereafter. Third, when seperated from cash flows, accruals have an incremental explanation about stock price changes beyond that of cash flows, accruals have a negative association later on. This finding is consistent with stock price overreaction to accruals, even when more cleaner cash flow data are used.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1214-1222
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• 1998

Background : The intrapleural hypofibrinolysis is caused by mainly excessive concentration of pleural plasminogen activator inhibitor-1 antigen(PAI-1 Ag), which binds tissue type plasminogen activator. In pleural inflammation induced by sclerosing agents for pleurodesis, levels of pleural PAI-1 antigen increase in relation to decreasing D-dimer levels. It has been known that the pleural mesothelial cells have the capability of secreting PAI-1 Ag in response to inflammation in vivo. Therefore, we estimated whether pleural inflammation changes the balance between fibrinolytic and coagulative properties in exudative pleural effusions. Method : The thirty cases was included in our study. We determined the pleural levels of glucose, lactic dehydrogenase(LDH), pH and the counts of white blood cell(WBC), polymorpho leukocyte(PMN), lymphocyte as the parameters of pleural inflammation and cellular components of pleural fluid. The plasma level of fibrinogen in fluid and the neutrophil count in blood were determined. The levels of D-dimer, PAI-1 Ag and thrombinantithrombin III complex(TAT) were determined by ELISA(Behring, Marburg, Germany). Result : The causes of pleural effusion were as following : tuberculous in 14 cases, malignant in 10 cases and parapneumonic in 6 cases. The levels of pleural D-dimer, PAI-1 Ag and TAT was significantly higher than that of plasma(p<0..001). The severity of pleural inflammation did not correlated with pleural D-dimer, PAI-1 Ag, TAT and their plasma levels. But the level of pleural TAT correlated with pleural WBC and lymphocyte count. Conclusion : We found that the severity of pleural inflammations did not correlated with pleural D-dimer, PAI-1 Ag, TAT and the possibility of local production of PAI-1 antigen is present.

• Journal of Korean Society of Forest Science
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• v.87 no.4
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• pp.519-527
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• 1998

An economic study of vegetation control to increase production of Songyi (Korean name far pine mushroom, matsutake, Tracholoma matsutake (S. Ito & Imai) Sing.) in red pine (Panes densiflora) stands in Korea was undertaken. In Korea, Songyi grows only in red pine stands. Harvest of this mushroom provides a significant income source to rural people in Korea yielding exports of US$20 million to US$80 million per year. However, hypogeous Songyi colonies and the mushroom production are declining, partly because shade tolerant species are succeeding the shade intolerant red pine. Past research says that it is possible to deep Songyi production increasing by controlling under-story vegetation. But few people are wilting to invest in the necessary control. Our analysis found that the economics of vegetation control appear to be quite favorable, showing an internal rate of return (IRR) of 20.7 percent in 15 years. However, positive returns do not occur for at least eight years and even then, the returns may not appear to the landowner to be a result of vegetation control efforts only because the mushroom production has been greatly variable depending on weather conditions. In a sensitivity analysis, it was found that the number of circular mushroom colonies was critically important for the cash flow. Results of this analysis are also sensitive to assumptions about annual growth length(0.16m radial growth=1.0m/circular length growth) of Songyi colony. However, the primary goal of vegetation control should be to keep the young colonies growing. Further research in the behavior of hypogeous Songyi colonies after vegetation control would help to improve our confidence in the results.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.153-164
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• 1999

The solubilization of BTEX was evaluated in aqueous surfactant solutions with and without several additives. Anionic surfactant(Sodium Dodecyl Sulfate, SDS) and nonionic surfactants (NEODOL(equation omitted)25-3 and $SOFTANOL\circledR-90$ were used as test surfactants. The effects of surfactant HLB(Hydrophile-Lipophile Balance) Number and hydrocarbon molar volume and polarity of BTEX on the MSR(Molar Solubilization Ratio), micelle-water partition coefficient of BTEX, and CMC(C,itical Micelle Concentration) were investigated. Optimizing treatment conditions applicable to enhanced solubilization was also studied by manupulating salinity or electrolyte control with additives of ethyl alcohol, hydrotrope, and electrolyte solution. The most effective surfactant for solubilization was found $SOFTANOL\circledR-90$, since HLB number of 13.6 is similar to those values of BTEX ranging between 11.4 and 12.2, which was also proved experimentally. Ethyl alchohol of 3% was the most effective additives in reducing CMC and improving solubilization among the conditions using SDS, NEODOL(equation omitted)25-3, and $SOFTANOL\circledR-90$ with three additives. The partitioning of BTEX between surfactant micelles and aqueous solutions was characterized by a mole fraction micelle-phase/aqueous phase partion coefficient, $K_m$. Values of log $K_m$. for BTEX compounds in surfactant solutions of this study range from 2.95 to 3.76(100mM SDS) and 2.95 to 3.49(117mM $SOFTANOL\circledR-90$. Log $K_m$ appears to be a linear function of log $K_{ow}$ for SDS and $SOFTANOL\circledR-90$. A knowledge of partitioning of BTEX in aqueous surfactant system can be a prerequisite for the understanding of the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in remediation of contaminated soil and facilitated transport.

• Journal of Korean Home Economics Education Association
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• v.31 no.3
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• pp.179-192
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• 2019

This study was performed to analyze the contents of food intake in middle school Home Economics textbook and the trends of food intake of middle school students in Korea to figure out the education direction of food intake. The contents of food intake were analyzed in major three kinds of middle school Home Economics textbook according to 2015 curriculum and the trends of food and nutrient intake were analyzed in 2,543 subjects aged 13 to 15 years using 2007~2015 Korea National Health and Nutrition Examination survey by logistic regression analysis or Pearson correlation coefficient. As a result, contents of food intake of textbook included food source of nutrient, food group name, necessity of eating diverse foods, recommended daily eating frequency of food group and menu planning according to meal composition guideline, however food intake trends were not included. Consumption of grains and grain products was increased until 2007 to 2010 year and was decreased after 2011 year(p=0.0012). Sugars and sweets, beverages and alcohols, and fish and shellfish consumption were increased during 2007~2015 year(p<0.0001). Carbohydrate, fat, vitamin A, thiamin and iron intakes were increased(p=0.0052), and energy ratio by carbohydrate was decreased(p=0.0009) and energy ratio by fat was increased(p<0.0001) during 2007~2015 year. Mean ratios of nutrient intake compared to the dietary reference intakes for Koreans were very low in dietary fiber(19-27%) and calcium(46-56%), but was higher in sodium(221-289%)(p<0.0001) regardless of year. There was a significant positive correlation between most food group intakes except sugars and sweets, bean and bean products, nuts and seeds, seaweeds, and beverages and alcohols and energy, protein, dietary fiber, vitamin A, riboflavin, calcium and iron intakes(p=0.0375). In the above, during the period from 2007 to 2015 year, intakes of sugars and sweets, beverages and alcohols, and fish and shellfish were increased, and intakes of dietary fiber and calcium were low and energy ratio by fat was increased, thus these trends are concerned to threaten nutritional balance and health of subjects. Therefore, Home Economics textbook of middle school needs to include food intake trends of adolescents with basic concepts to help them maintain balanced diet in the rapid change of food intake patterns for maintaining optimal nutrition and health.