• Journal of The Korean Society of Inherited Metabolic disease
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• 제18권1호
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• pp.1-12
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• 2018

Purpose: Disorders of organic acid metabolism have various clinical manifestations and it may be life-threatening. The prognoses of affected children are dependent on early diagnosis and treatment. We report this study to find out detection rate of referred samples, clinical manifestations and age distribution after introduction of neonatal screening test using tandem mass spectrometry in Hallym University Chuncheon Sacred Heart Hospital during 8 years and 9 months. Methods: The 2,794 patients referred from Jan. 2007 to Sep. 2015 were divided into four groups according to age. We conducted organic acid analysis of urine samples of patients and analyzed clinical manifestations and distributions of age at the diagnosis. For patients with ambiguous results, reanalysis of urine organic acid after diet restriction, protein loading and restriction, has been done. Results: A total of 626 patients with 20 disorders were diagnosed. Mitochondrial disorders (482 patients) were the most common diagnosis, followed by ketolytic defects (67), 3-hydroxyisobutyric aciduria (32), EPEMA syndrome (8), 3-methylcrotonyl glycinuria (7), glutaric aciduria type II (6) and type I (4), methylmalonic aciduria (3), isovaleric aciduria (3) and medium chain acyl-CoA dehydrogenase deficiency (3). Conclusion: As neonatal screening test using tandem mass spectrometry is increasingly common and medical environment is changed, detection rate of disorders of organic acid metabolism in this study has decreased compared to previous report. Because the deterioration can be prevented by early diagnosis and treatment, many pediatricians have to pay special attention to possibility of the disorders and make an effort for early diagnosis in clinical setting.

• Korean Journal of Environment and Ecology
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• 제25권4호
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• pp.601-613
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• 2011

The purpose of this study is to provide an protected wildlife species and potential habitats in Seoul through the overall present status of the species which live in Seoul. This study was performed in Seoul, the entire area of which is 605.52 $km^2$. We analyzed a total of 57 studies, including academic papers and research reports, for the natural ecology in Seoul. As for the results from the study, it was found that a total 1,907 species from 5 taxa were inhabiting and growing within the area. Among the total, plants of 1,656 species accounted for 86.7%, 197 species of wild birds made up 10.3%, 29 species of amphibians and reptiles consisted of 1.5%, and 27 species of mammalia totaled 1.4%. A total of 440 species except foreign species and species legally preserved by the Ministry of Environment, common species and uncertain species were selected as primary candidates. By taxon, it shows 212 species of plants, 180 species of wild birds, 24 species of mammalia, and 24 species of amphibians and reptiles. For extensive research subjects and research data limited in certain insect family, analysis by literature for discovered insects was excluded. The selection criteria for the second candidate species was based on extinction crisis, rarity, historicity and locality, academic value, habitat specificity, etc. The second candidate species from the primary species were selected through taxon experts' evaluations. As for the results of the selection of the second candidates, a total 77 species were selected through the experts' evaluations. Each species by taxon was 25 species for plants, 21 species for wild birds, 5 for mammalia, 10 for amphibians and reptiles and 16 species for insects. A site investigation for the second candidates was conducted to select the final candidate species. For the target areas, the habitats of the second candidates given by the literature and 46 potential areas in Seoul, which show good natural resistance, were finally selected. From the result of the site investigation, it was found that 14 species of plants, 19 species of wild birds, 2 species of mammalia, 4 species of amphibians and reptiles, and 16 species of insects were actually inhabiting Seoul; thus, the final 55 protected species were selected.

• The Korean Journal of Financial Management
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• 제21권2호
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• pp.27-63
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• 2004

Since the 1980s, many multinational corporations have been issuing stocks on foreign stock exchanges, not only to enhance their investor base and liquidity, but also to diversify risks. The phenomenon has also been intensified by the rapid financial globalization and securitization trends. The main purpose of this study is to look into the long-run performance of MNCs' cross-listings of stocks on foreign stock exchanges. We use the event study and cross-sectional regression methods. We obtained some interesting empirical results about the long-run effect of cross-listings. First before the listing data the effect of cross-listing is to increase the underlying stock Vice in the local market. It may be caused by expectation of lower risk and cost of capital. However, after the listing data the stock price has been declining, even if it is not significant. Second, we examine the difference in the long-run cross-listing effect, which may be caused by the listing direction. When listing is made from a less developed market to a more developed market, the effect is better than that in the reverse direction. Furthermore, the effect is worse, when the listing company's home country is the U.S. Third, there is a negative relation between CARs and underlying stock liquidity in the local market, So it implies that a firm, whose underlying stocks are very liquid in the local market should carefully value cross-listing based upon the cost and benefit analysis. Last, but not the least we find that the long-un cross-listing effect is better, when a listing firm's ROE is higher.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제8권6호
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• pp.1634-1647
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• 2007

"To invest or not to invest?" Most business leaders are frequently faced with this question on new and ongoing projects. The challenge lies in deciding what projects to choose, expand, contract, defer, or abandon. The project valuation tools used in this process are vital to making the right decisions. Traditional tools such as discounted cash flow (DCF)/net present value (NPV) assume a "fixed" path ahead, but real world projects face uncertainties, forcing us to change the path often. Comparing to other traditional valuation methods, the real options approach captures the flexibility inherent to investment decisions. The use of real options has gained wide acceptance among practitioners in a number of several industries during the last few decades. Even though the options are present in all types of business decisions, it is still not considered as a proper method of valuation in some industries. Mining has been comparably slow to adopt new valuation techniques over the years. The reason fur this is not entirely clear. One possible reason is the level and types of risks in mining. Not only are these risks high, but they are also more numerous and involve natural risks compared with other industries. That is why the purpose of this study is to deal with a more practical approach to project valuation, known as real options analysis in mining industry. This paper provides a case study approach to the copper mining industry using a real options analysis. It shows how companies can minimize investment risks, exercise flexibility in decision making and maximize returns.

• Journal of Soil and Groundwater Environment
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• 제10권4호
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• pp.1-12
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• 2005

Policies regarding to soil quality of the United States, the United Kingdom, the Netherlands, Germany, and Demark were analyzed to suggest Korean policy for improving soil quality concept and it's implementation. All countries met four criteria: I) Soil quality levels of contaminants are indebt to concept of contaminant risk to recipients (human and ecosystem); ii) Any soil quality value can't be a magic number to determine whether a site is contaminated or not. To determine risk of sites, risk assessment of the sites should be followed; iii) Concentrations of contaminants of sites are not always significantly certain to risk of human and ecosystem of the sites; and iv) Soil quality levels are adopted based on land uses and plans. Considering our rooms to improve policies and analysis of the other country reports on their legislations about soil quality levels, our policy implementation could be approached from these directions: i) Our concept for soil quality levels needs to develop in scientific and rational. ii) Soil quality levels and risk assessment should be implemented as determining tools of site contamination in parallel, and iii) Soil quality levels depending on land uses and plans should be developed in debt with rational and scientific concept of risk. Increasing efficacy of Korea policy regarding the soil quality levels would be in dept to applying concepts of SCL (Soil Contamination Level) and SRL (Soil Regulatory Level) developed, implementing soil quality levels and risk assessment of contaminated sites in conjunction, and classifying three distinctions of land uses based on sensitiveness of recipients (human and ecosystem) to contaminants in soil in this research.

• Journal of Korea Port Economic Association
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• 제39권1호
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• pp.65-100
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• 2023

This study examines the effects of organizational trust of the container terminal operators' employee on organizational citizenship behavior and the moderating effect of organizational support in the relationship between the two variables. In order to efficiently achieve the purpose of this study, an empirical analysis was conducted by distributing a literature review and a questionnaire, and the results of the study are as follows... First, the organizational trust of the container terminal operators' employee was found to have a significant positive (+) effect on organizational citizenship behavior, and trust in the company appeared to be more important than trust in the superior, indicating trust in the institutional aspect. This means that formation has more influence on organizational citizenship behavior... Second, it was confirmed that the organizational support of the container terminal operators' employee can lead to active participation in organizational citizenship behavior through the expansion of educational compensatory support. Third, among the organizational support of container terminal operators, emotional support and educational compensatory support were found to have a partial moderating effect on the relationship between organizational trust and organizational citizenship behavior." Emotional support has a moderating effect on caring and active participation behaviors in the relationship between trust in the company and organizational citizenship behaviors, and a moderating effect on caring, active participation, and non-complaining behaviors in the relationship between trust in superiors and organizational citizenship behaviors. It was analyzed that there is Compensatory educational support has a moderating effect on altruistic, caring, active participation, and non-complaining behavior in the relationship between trust in the company and organizational citizenship behavior. It was analyzed that there was a moderating effect on active participation and non-complaining behavior. These analysis results mean that members' trust in the company further increases through the container terminal operator's emotional support and educational reward support. As uncertainty grows, it is very important to increase the trust of organizational members in the organization. sense of belonging to the organization, Emotional support that can increase immersion, improvement of work environment, provision of educational opportunities, and education-compensatory support such as a fair compensation system will increase organizational trust and induce effective organizational citizenship behavior to realize sustainable growth of the organization.

• Journal of Korea Water Resources Association
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• 제56권2호
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• pp.75-89
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• 2023

As the Mekong River basin is a nationally shared river, it is difficult to collect precipitation data, and the quantitative and qualitative quality of the data sets differs from country to country, which may increase the uncertainty of hydrological analysis results. Recently, with the development of remote sensing technology, it has become easier to obtain grid-based precipitation products(GPPs), and various hydrological analysis studies have been conducted in unmeasured or large watersheds using GPPs. In this study, rainfall-runoff simulation in the Mekong River basin was conducted using the SWAT model, which is a quasi-distribution model with three satellite GPPs (TRMM, GSMaP, PERSIANN-CDR) and two GPPs (APHRODITE, GPCC). Four water level stations, Luang Prabang, Pakse, Stung Treng, and Kratie, which are major outlets of the main Mekong River, were selected, and the parameters of the SWAT model were calibrated using APHRODITE as an observation value for the period from 2001 to 2011 and runoff simulations were verified for the period form 2012 to 2013. In addition, using the ConvAE, a convolutional neural network model, spatio-temporal correction of original satellite precipitation products was performed, and rainfall-runoff performances were compared before and after correction of satellite precipitation products. The original satellite precipitation products and GPCC showed a quantitatively under- or over-estimated or spatially very different pattern compared to APHPRODITE, whereas, in the case of satellite precipitation prodcuts corrected using ConvAE, spatial correlation was dramatically improved. In the case of runoff simulation, the runoff simulation results using the satellite precipitation products corrected by ConvAE for all the outlets have significantly improved accuracy than the runoff results using original satellite precipitation products. Therefore, the bias correction technique using the ConvAE technique presented in this study can be applied in various hydrological analysis for large watersheds where rain guage network is not dense.

• Journal of the Korean Geotechnical Society
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• 제15권4호
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• pp.113-132
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• 1999

Recently in Korea, application of the soil nailing is gradually extended to the sites of excavations and slopes having various ground conditions and field characteristics. Design of the soil nailing is generally carried out in two steps, The First step is to examine the minimum safety factor against a sliding of the reinforced nailed-soil mass based on the limit equilibrium approach, and the second step is to check the maximum displacement expected to occur at facing using the numerical analysis technique. However, design parameters related to the soil nailing system are so various that a reliable design method considering interrelationships between these design parameters is continuously necessary. Additionally, taking into account the anisotropic characteristics of in-situ grounds, disturbances in collecting the soil samples and errors in measurements, a systematic analysis of the field measurement data as well as a rational technique of the optimum design is required to improve with respect to economical efficiency. As a part of these purposes, in the present study, a procedure for the optimum design of a soil nailing excavation wall system is proposed. Focusing on a minimization of the expenses in construction, the optimum design procedure is formulated based on the genetic algorithm. Neural network theory is further adopted in predicting the maximum horizontal displacement at a shotcrete facing. Using the proposed procedure, various effects of relevant design parameters are also analyzed. Finally, an optimized design section is compared with the existing design section at the excavation site being constructed, in order to verify a validity of the proposed procedure.

• Journal of the Korean Association of Geographic Information Studies
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• 제18권4호
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• pp.81-99
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• 2015

The acceleration of global warming has required better understanding of carbon cycles over local and regional areas such as the Korean peninsula. Since forests serve as a carbon sink, which stores a large amount of terrestrial carbon, there has been a demand to accurately estimate such forest carbon sequestration. In Korea, the National Forest Inventory(NFI) has been used to estimate the forest carbon stocks based on the amount of growing stocks per hectare measured at sampled location. However, as such data are based on point(i.e., plot) measurements, it is difficult to identify spatial distribution of forest carbon stocks. This study focuses on urban areas, which have limited number of NFI samples and have shown rapid land cover change, to estimate grid-based forest carbon stocks based on UNFCCC Approach 3 and Tier 3. Land cover change and forest carbon stocks were estimated using Landsat 5 TM data acquired in 1991, 1992, 2010, and 2011, high resolution airborne images, and the 3rd, 5th~6th NFI data. Machine learning techniques(i.e., random forest and support vector machines/regression) were used for land cover change classification and forest carbon stock estimation. Forest carbon stocks were estimated using reflectance, band ratios, vegetation indices, and topographical indices. Results showed that 33.23tonC/ha of carbon was sequestrated on the unchanged forest areas between 1991 and 2010, while 36.83 tonC/ha of carbon was sequestrated on the areas changed from other land-use types to forests. A total of 7.35 tonC/ha of carbon was released on the areas changed from forests to other land-use types. This study was a good chance to understand the quantitative forest carbon stock change according to the land cover change. Moreover the result of this study can contribute to the effective forest management.

• Journal of Science Education
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• 제33권2호
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• pp.336-345
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• 2009

The purpose of this study is to analysis ERF components patterns of causal questions generated during the observation of biological phenomenon. First, the system that shows pictures causing causal questions based on biological phenomenon (evoked picture system) was developed in a way of cognitive psychology. The ERF patterns of causal questions based on time-series brain processing was observed using MEG. The evoked picture system was developed by R&D method consisting of scientific education experts and researchers. Tasks were classified into animal (A), microbe (M), and plant (P) tasks according to biological species and into interaction (I), all (A), and part (P) based on the interaction between different species. According to the collaboration with MEG team in the hospital of Seoul National University, the paradigm of MEG task was developed. MEG data about the generation of scientific questions in 5 female graduate student were collected. For examining the unique characteristic of causal question, MEG ERF components were analyzed. As a result, total 100 pictures were produced by evoked picture and 4 ERF components, M1(100~130ms), M2(220~280ms), M3(320~390ms), M4(460~520ms). The present study could guide personalized teaching-learning method through the application and development of scientific question learning program.