• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.1
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• pp.25-37
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• 2011

Objectives：This study was conducted to develop a Korean algorithm of pharmacological and non-pharmacological treatment strategies in attention-deficit hyperactivity disorder (ADHD) and its specific comorbid disorders (e.g. tic disorder, depressive disorder, anxiety disorder, bipolar disorder, and oppositional defiant disorder/conduct disorder). Methods：Based on a literature review and expert consensus, both paper- and web-based survey tools were developed with respect to a comprehensive range of questions. Most options were scored using a 9-point scale for rating the appropriateness of medical decisions. For the other options, the surveyed experts were asked to provide answers (e.g., duration of treatment, aver-age dosage) or check boxes to indicate their preferred answers. The survey was performed on-line in a self-administered manner. Ultimately, 49 Korean child & adolescent psychiatrists, who had been considered experts in the treatment of ADHD, vol untarily completed the questionnaire. In analyzing the responses to items rated using the 9-point scale, consensus on each option was defined as a non-random distribution of scores as determined by a chi-square test. We assigned a categorical rank (first line/preferred choice, second line/alternate choice, third line/usually inappropriate) to each option based on the 95% confidence interval around the mean rating score. Results：Specific medication strategies for key clinical situations in ADHD and its comorbid disorders were indicated and described. We organized the suggested algorithms of ADHD treatment mainly on the basis of the opinions of the Korean experts. The suggested algorithm was constructed according to the templates of the Texas Child & Adolescent medication algorithm Project (CMAP). Conclusion：We have proposed a Korean treatment algorithm for ADHD, both with and without comorbid disorders through expert consensus and a broad literature review. As the tools available for ADHD treatment evolve, this algorithm could be reorganized and modified as required to suit updated scientific and clinical research findings.

• (The)Korea Educational Review
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• v.15 no.1
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• pp.107-132
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• 2009

What is good instruction? The term "instruction" means the essential activity of school education, a precondition for good school, and the starting point of reforming school education. The purpose of this study is to investigate the meaning of "good instruction" by examining the difference of perception between in-service teachers and pre-service teachers who encompass the viewpoint of both teacher and student using open-ended questionnaires asking the type of instruction that they have to avoid and the undesirable instruction. This study was carried out with 150 teachers who were working in the schools and 160 students who were in college of education to be teacher in the future. Collected data was analyzed using the QSR Nvivo qualitative program. The findings of this study indicates the followings: First, the most undesirable class cited by in-service teachers was the class that applies uniform instructional strategy, followed by class based on directions instruction, unsystematic class, class characterized by lack of teaching competency, class that emphasizes test scores and competition, class that are not interactive enough, class that does not consider the level of students, class in which students are not respected, class that have poor educational environment, and the class in which little support is provided. Second, the most undesirable class cited by pre-service teachers was the class that applies uniform instructional strategy, followed by unsystematic class, class characterized by lack of teaching competency, class based on directions instruction, class in which students are not respected, class that emphasizes test scores and competition, class that does not consider the level of students, class that are not interactive enough, class that have poor educational environment, and the class in which little support is provided. Third, this study examined the difference of perception between in-service teachers and pre-service teachers toward the undesirable class that they have to avoid. In terms of the integrated rank that is common among in-service teachers and pre-service teachers, the most undesirable class that they have to avoid was the class that applies uniform instructional strategy, unsystematic class, class based on directions instruction, and class characterized by lack of teaching competency. The findings of this study may be used as a basis for in-service teachers to reflect on their professionalism of instruction that they provide and examine the attitude of students toward instruction, while providing a practical guideline for pre-service teachers to design and ensure systematic instruction in the future.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.172-186
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• 2022

Benthic macroinvertebrates are important ecological and environmental indicators as primary or secondary consumers, and therefore are widely used in the evaluation of aquatic environments. However, there are no comprehensive river ecosystem monitoring surveys that link the major physicochemical water quality items with benthic macroinvertebrates in urban streams. Therefore, this study investigated the distribution characteristics of benthic macroinvertebrates and physicochemical water quality items (17 items) in Yangjaecheon and Yeouicheon from 2019 to 2020. At the same time, by applying Spearman's rank correlation analysis and nonmetric multidimensional scaling (nMDS) analysis in the water quality data and biotic index, we tried to provide basic data for diagnosing the current status of river ecosystems in major urban rivers in Seoul. Based on the study results, a total of 39 species and 3,787 individuals were identified in Yangjaecheon, the water quality(based on BOD, TOC, and TP) of Yangjaecheon was higher than Grade Ib(good), and the BMI using benthic macroinvertebrates appeared as Grade C(normal) at all the sites. In Yeouicheon, a total of 51 species and 4,199 individuals were identified, the water quality(based on BOD, TOC, TP) was higher than Grade Ib(good) similar to Yangjaecheon, and the BMI of both Upstream and Saewon bridge was Grade B(good), while Yeoui bridge was Grade C(normal). Overall, analysis results for the distribution of benthic macroinvertebrates by a nonmetric multidimensional scaling method showed no significant difference between the two streams (p=0.1491). Also, significant environmental variables related to benthic macroinvertebrates distribution were determined as water temperature and DO. On the other hand, the results of the correlation analysis between biotic index and major water quality items confirmed that R1 and BMI could be used for on-site urban river water quality evaluation.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.105-129
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• 2020

This study uses corporate data from 2012 to 2018 when K-IFRS was applied in earnest to predict default risks. The data used in the analysis totaled 10,545 rows, consisting of 160 columns including 38 in the statement of financial position, 26 in the statement of comprehensive income, 11 in the statement of cash flows, and 76 in the index of financial ratios. Unlike most previous prior studies used the default event as the basis for learning about default risk, this study calculated default risk using the market capitalization and stock price volatility of each company based on the Merton model. Through this, it was able to solve the problem of data imbalance due to the scarcity of default events, which had been pointed out as the limitation of the existing methodology, and the problem of reflecting the difference in default risk that exists within ordinary companies. Because learning was conducted only by using corporate information available to unlisted companies, default risks of unlisted companies without stock price information can be appropriately derived. Through this, it can provide stable default risk assessment services to unlisted companies that are difficult to determine proper default risk with traditional credit rating models such as small and medium-sized companies and startups. Although there has been an active study of predicting corporate default risks using machine learning recently, model bias issues exist because most studies are making predictions based on a single model. Stable and reliable valuation methodology is required for the calculation of default risk, given that the entity's default risk information is very widely utilized in the market and the sensitivity to the difference in default risk is high. Also, Strict standards are also required for methods of calculation. The credit rating method stipulated by the Financial Services Commission in the Financial Investment Regulations calls for the preparation of evaluation methods, including verification of the adequacy of evaluation methods, in consideration of past statistical data and experiences on credit ratings and changes in future market conditions. This study allowed the reduction of individual models' bias by utilizing stacking ensemble techniques that synthesize various machine learning models. This allows us to capture complex nonlinear relationships between default risk and various corporate information and maximize the advantages of machine learning-based default risk prediction models that take less time to calculate. To calculate forecasts by sub model to be used as input data for the Stacking Ensemble model, training data were divided into seven pieces, and sub-models were trained in a divided set to produce forecasts. To compare the predictive power of the Stacking Ensemble model, Random Forest, MLP, and CNN models were trained with full training data, then the predictive power of each model was verified on the test set. The analysis showed that the Stacking Ensemble model exceeded the predictive power of the Random Forest model, which had the best performance on a single model. Next, to check for statistically significant differences between the Stacking Ensemble model and the forecasts for each individual model, the Pair between the Stacking Ensemble model and each individual model was constructed. Because the results of the Shapiro-wilk normality test also showed that all Pair did not follow normality, Using the nonparametric method wilcoxon rank sum test, we checked whether the two model forecasts that make up the Pair showed statistically significant differences. The analysis showed that the forecasts of the Staging Ensemble model showed statistically significant differences from those of the MLP model and CNN model. In addition, this study can provide a methodology that allows existing credit rating agencies to apply machine learning-based bankruptcy risk prediction methodologies, given that traditional credit rating models can also be reflected as sub-models to calculate the final default probability. Also, the Stacking Ensemble techniques proposed in this study can help design to meet the requirements of the Financial Investment Business Regulations through the combination of various sub-models. We hope that this research will be used as a resource to increase practical use by overcoming and improving the limitations of existing machine learning-based models.

• Journal of Intelligence and Information Systems
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• v.20 no.1
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• pp.195-211
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• 2014

Cloud computing services provide IT resources as services on demand. This is considered a key concept, which will lead a shift from an ownership-based paradigm to a new pay-for-use paradigm, which can reduce the fixed cost for IT resources, and improve flexibility and scalability. As IT services, cloud services have evolved from early similar computing concepts such as network computing, utility computing, server-based computing, and grid computing. So research into cloud computing is highly related to and combined with various relevant computing research areas. To seek promising research issues and topics in cloud computing, it is necessary to understand the research trends in cloud computing more comprehensively. In this study, we collect bibliographic information and citation information for cloud computing related research papers published in major international journals from 1994 to 2012, and analyzes macroscopic trends and network changes to citation relationships among papers and the co-occurrence relationships of key words by utilizing social network analysis measures. Through the analysis, we can identify the relationships and connections among research topics in cloud computing related areas, and highlight new potential research topics. In addition, we visualize dynamic changes of research topics relating to cloud computing using a proposed cloud computing "research trend map." A research trend map visualizes positions of research topics in two-dimensional space. Frequencies of key words (X-axis) and the rates of increase in the degree centrality of key words (Y-axis) are used as the two dimensions of the research trend map. Based on the values of the two dimensions, the two dimensional space of a research map is divided into four areas: maturation, growth, promising, and decline. An area with high keyword frequency, but low rates of increase of degree centrality is defined as a mature technology area; the area where both keyword frequency and the increase rate of degree centrality are high is defined as a growth technology area; the area where the keyword frequency is low, but the rate of increase in the degree centrality is high is defined as a promising technology area; and the area where both keyword frequency and the rate of degree centrality are low is defined as a declining technology area. Based on this method, cloud computing research trend maps make it possible to easily grasp the main research trends in cloud computing, and to explain the evolution of research topics. According to the results of an analysis of citation relationships, research papers on security, distributed processing, and optical networking for cloud computing are on the top based on the page-rank measure. From the analysis of key words in research papers, cloud computing and grid computing showed high centrality in 2009, and key words dealing with main elemental technologies such as data outsourcing, error detection methods, and infrastructure construction showed high centrality in 2010~2011. In 2012, security, virtualization, and resource management showed high centrality. Moreover, it was found that the interest in the technical issues of cloud computing increases gradually. From annual cloud computing research trend maps, it was verified that security is located in the promising area, virtualization has moved from the promising area to the growth area, and grid computing and distributed system has moved to the declining area. The study results indicate that distributed systems and grid computing received a lot of attention as similar computing paradigms in the early stage of cloud computing research. The early stage of cloud computing was a period focused on understanding and investigating cloud computing as an emergent technology, linking to relevant established computing concepts. After the early stage, security and virtualization technologies became main issues in cloud computing, which is reflected in the movement of security and virtualization technologies from the promising area to the growth area in the cloud computing research trend maps. Moreover, this study revealed that current research in cloud computing has rapidly transferred from a focus on technical issues to for a focus on application issues, such as SLAs (Service Level Agreements).

• Journal of Global Scholars of Marketing Science
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• v.19 no.3
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• pp.28-36
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• 2009

While existing literature has focused extensively on the strengths and weaknesses of the Chaebol and their ownership and governance, there have been few studies of Korean non-Chaebol firms. However, Lee, Lee and Pennings (2001) did not specifically investigate the competitive strategies that non-Chaebol firms use to survive against the Chaebol in the domestic Korean market. The motivation of this paper is to document, through four exploratory case studies, the successful competitive strategies of non-Chaebol Korean companies against the Chaebol and then offer some propositions that may be useful to other entrepreneurial firms as well as public policy makers. Competition and cooperation as conceptualized by product similarity and cooperative inter.firm relationship respectively, are major dimensions of firm.level marketing strategy. From these two dimensions, we develop the following $2{\times}2$ matrix, with 4 types of competitive strategies for non-Chaebol companies against the Chaebol (Fig. 1.). The non-Chaebol firm in Cell 1 has a "me-too" product for the low-end market while conceding the high-end market to a Chaebol. In Cell 2, the non-Chaebol firm partners with a Chaebol company, either as a supplier or complementor. In Cell 3, the non-Chaebol firm engages in direct competition with a Chaebol. In Cell 4, the non-Chaebol firm targets an unserved part of the market with an innovative product or service. The four selected cases such as E.Rae Electronics Industry Company (Co-exister), Intops (Supplier), Pantech (Competitor) and Humax (Niche Player) are analyzed to provide each strategy with richer insights. Following propositions are generated based upon our conceptual framework: Proposition 1: Non-Chaebol firms that have a cooperative relationship with a Chaebol will perform better than firms that do not. Proposition 1a; Co-existers will perform better than Competitors. Proposition 1b: Partners (suppliers or complementors) will perform better than Niche players. Proposition 2: Firms that have no product similarity with a Chaebol will perform better than firms that have product similarity. Proposition 2a: Partners (suppliers or complementors) will perform better than Co.existers. Proposition 2b: Niche players will perform better than Competitors. Proposition 3: Niche players should perform better than Co-existers. Proposition 4: Performance can be rank.ordered in descending order as Partners, Niche Players, Co.existers, Competitors. A team of experts was constituted to categorize each of these 216 non-Chaebol companies into one of the 4 cells in our typology. Simple Analysis of Variance (ANOVA) in SPSS statistical software was used to test our propositions. Overall findings are that it is better to have a cooperative relationship with a Chaebol and to offer products or services differentiated from a Chaebol. It is clear that the only profitable strategy, on average, to compete against the Chaebol is to be a partner (supplier or complementor). Competing head on with a Chaebol company is a costly strategy not likely to pay off for a non-Chaebol firm. Strategies to avoid head on competition with the Chaebol by serving niche markets with differentiated products or by serving the low-end of the market ignored by the Chaebol are better survival strategies. This paper illustrates that there are ways in which small and medium Korean non-Chaebol firms can thrive in a Chaebol environment, though not without risks. Using different combinations of competition and cooperation firms may choose particular positions along the product similarity and cooperative relationship dimensions to develop their competitive strategies-co-exister, competitor, partner, niche player. Based on our exploratory case-study analysis, partner seems to be the best strategy for non-Chaebol firms while competitor appears to be the most risky one. Niche players and co-existers have intermediate performance, though the former do better than the latter. It is often the case with managers of small and medium size companies that they tend to view market leaders, typically the Chaebol, with rather simplistic assumptions of either competition or collaboration. Consequently, many non-Chaebol firms turn out to be either passive collaborators or overwhelmed competitors of the Chaebol. In fact, competition and collaboration are not mutually exclusive, and can be pursued at the same time. As suggested in this paper, non-Chaebol firms can actively choose to compete and collaborate, depending on their environment, internal resources and capabilities.

• 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.

• Water for future
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• v.28 no.6
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• pp.147-158
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• 1995

The purpose of this study is to establish a method of estimating the daily urban water demand using statistical model. This method will be used for the development of the efficient management and operation of the water supply facilities. The data used were the daily urban water use, the population, the year lapse and the weather conditions such as temperature, precipitation, relative humidity, etc. Kwangju city was selected for the case study area. The raw data used in this study were rearranged either by month or by season for the purpose of analysis, and the statistical analysis was applied to the data to obtain the regression model. As a result, the multiple linear regression model was developed to estimate the daily urban water use based on the seather condition. The regression constant and the model coefficients were determined for each month of a year. The accuracy of the model was within 3% of average error and within 10% of maximum error. The developed model was found to be useful to the practical operation and management of the water supply facilities.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.12-26
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• 2014

This study has researched the forms of arrangement and use of the oddly shaped stones which were used at palaces during Joseon Dynasty based on arrangements of stones as shown in Donggwoldo(東闕圖), and tried to identify its special features. The sorts of stone's arrangements which set formal patterns by assisting an axis in Donggwoldo can be classified as the single type using one stone, the symmetrical type using 2 stones symmetrically and the parallel type using 3 or more stones. The single type was used to endow a focal point and to accent centrality by arranging a stone on the axis performed from formal shaped buildings. The symmetrical type was used to show order and hierarchy by placing two odd-shaped stones on either side of a building. And the parallel type which is arranged three stones side by side, is put a middle stone on the central axis line to determine strong directional and frontality. Also similarity to method of arrangement of stones can be found from planting trees in a prominent way for scenery or planting trees symmetrically. Stones and trees can be chosen according to nature and scale of places and basically their effects of formation of axis and creating typical space is same. Based on these respect, the characteristics of arrangement of stones shown in Donggwoldo can be briefly summarized as follows. First, the oddly shaped stones were used by creating a centripetal space in order to show a grade of rank. Second, the distances among stones could be adjusted to the sizes of the architecture which was at the center. The aim was to provide stability through the balanced composition between the central axis and symmetrical structures. Third, the form of regularity was added by using stone vase in consideration of irregular shape of stone causing interference in forming regular symmetry. Fourth, a centrality was emphasized by adding change to central stones in the parallel type used 3 erect stones. Fifth, the sizes of stone were limited in order to make smooth for the mix and adjustment of its position with the types of other garden ornaments, so the oddly shaped stones in palace have portability. Sixth, the oddly shaped stones in palace which were appreciated as inspirational object basically were a sculpture of the same quality with suiseki (壽石), and the appreciative method, the composition and shape had developed in the same texture. Finally, the even number of stones by parallel type were arranged by equal partition. But odd number of stones followed the method with symmetrical arrangement on its center stone. These principles of stone arrangement are judged as distinguishing methods which oddly shaped stones was made and used in Joseon palaces.

• Korean Security Journal
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• no.22
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• pp.91-111
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• 2010

Around the middle of the ninth century the strict bone-rank system of Silla frustrated many people who had political ambition but lacked nobility. They had to seek other ways, including maritime trade. Such an undertaking reflected and also increased their economic and military power. Trade prospered with T'ang China and with Japan as well. The threat of piracy to Silla's thriving maritime trade caused to create a succession of garrisons at important coastal points. Chonghae Jin (Chonghae garrison) was regarded as the most important of these. It was established in 828 by Chang Pogo. Chonghae Jin was on Wando, an island just east of the southwestern tip of Korea and a key place at this time in the trade between China, Korea, and Japan. From this vantage point Chang Pogo became a merchant-prince with extensive holdings and commercial interests in China and with trade contacts with Japan. Although piracy was rampant in East Asia at that time, either the Chinese or Silla government was not able to control it due to inner political strife and lack of policing resources. Infuriated by the piracy and the government's inability to control it, Chang Pogo came back to Silla to fight against the pirates and to protect maritime trade. He persuaded the king of Silla and was permitted to control the private armed forces to sweep away the pirates. In 829 he was appointed Commissioner of Chonghae-Jin with the mission of curbing piracy in that region. Chang's forces were created to protect people from pirates, but also developed into traders among Silla Korea, T'ang China, and Japan in the 9th century. This was geographically possible because the Chonghae Garrison was situated at the midpoint of Korea, China, and Japan, and also because Chang's naval forces actually dominated the East Asia Sea while patrolling sea-lanes. Based on these advantages, Chang Pogo made a great fortune, which might be collected from a charge for protecting people from pirates and the trades with China and Japan. Chang's forces could be termed the first private security company in the Korean history, at least in terms of historical documents. Based on historical documents, the numbers of private soldiers might be estimated to exceed tens of thousands at least, since Chang's forces alone were recorded to be more than ten thousand. Because local powers and aristocratic elites were said to have thousands of armed forces respectively, the extent of private forces was assumed to be vast, although they were available only to the privileged class. In short, the domination of Chang's forces was attributable to the decline of central government and its losing control over local powers. In addition it was not possible without advanced technologies in shipbuilding and navigation.