• Journal of Korea Water Resources Association
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• v.52 no.1
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• pp.51-60
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• 2019

The major purpose of this study is to construct an in-situ soil moisture verification network employing Frequency Domain Reflectometry (FDR) sensors for Cosmic-ray soil moisture observation system operation as well as long-term field-scale soil moisture monitoring. The test bed of Cosmic-ray and FDR verification network system was established at the Sulma Catchment, in connection with the existing instrumentations for integrated data provision of various hydrologic variables. This test bed includes one Cosmic-ray Neutron Probe (CRNP) and ten FDR stations with four different measurement depths (10 cm, 20 cm, 30 cm, and 40 cm) at each station, and has been operating since July 2018. Furthermore, to assess the reliability of the in-situ verification network, the volumetric water content data measured by FDR sensors were compared to those calculated through the core sampling method. The evaluation results of FDR sensors- measured soil moisture against sampling method during the study period indicated a reasonable agreement, with average values of $bias=-0.03m^3/m^3$ and RMSE $0.03m^3/m^3$, revealing that this FDR network is adequate to provide long-term reliable field-scale soil moisture monitoring at Sulmacheon basin. In addition, soil moisture time series observed at all FDR stations during the study period generally respond well to the rainfall events; and at some locations, the characteristics of rainfall water intercepted by canopy were also identified. The Temporal Stability Analysis (TSA) was performed for all FDR stations located within the CRNP footprint at each measurement depth to determine the representative locations for field-average soil moisture at different soil profiles of the verification network. The TSA results showed that superior performances were obtained at FDR 5 for 10 cm depth, FDR 8 for 20 cm depth, FDR2 for 30 cm depth, and FDR1 for 40 cm depth, respectively; demonstrating that those aforementioned stations can be regarded as temporal stable locations to represent field mean soil moisture measurements at their corresponding measurement depths. Although the limit on study duration has been presented, the analysis results of this study can provide useful knowledge on soil moisture variability and stability at the test bed, as well as supporting the utilization of the Cosmic-ray observation system for long-term field-scale soil moisture monitoring.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.28-37
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• 2011

In this study, the series-poem, Bihaedangsasippalyoung(48 poems for beautiful scene of Bihaedang), written by scholars of Jiphyonjeon for Bihaedang garden of Anpyung-Daegun(Prince Anpyung, 1416-1453), was analyzed focusing on scenery lexeme to interpret the meaning of scenery and gardening culture of Sadaebu(noblemen) during the first term of Chosun Dynasty. The study result is as followings. First, the subtitle of Sasippalyoung(48 poems) written by Anpyung-Daegun while he grew Bihaedang garden on the foot of Inwang Mountain showed repetitive nomativity comparing joining of yin and yang, such as life and form of animal and plan, time and space, meaning and symbolism, etc. Among scenery lexemes, 38 are represented plant and flowers, and 8 are represented gardening ornaments and animals. Second, the names of gardens were expressed as Wonrim, Jongje, Imchon(Trees and Ponds), or Hwawon(Flower garden), or also presented as Gongjeong(Empty garden), Manwon(Full garden), Jungjeong(Middle garden), Huwon(Backyard), Wonrak(Inner court), or Byulwon(Seperated garden) depending on density and location. In addition, there were pavilions and ponds, stepping stones and stairs, a pergola, a flat bench, flowerpots, an artificial hill, oddly shaped stones, wells, aviary, flower beds, or hedges. A gardener was called Sahwa(flower keeper), planting and gardening of garden trees were called Jaebae(cultivation), a pond island was called Boogoo(floating hill), and miniature landscapes were called Chukjee(reduced land). Third, willows were planted on the outdoor yard, and plum trees were planted in front of the library, which led to bamboo woods road. Peony, camellia, tree peony and crepe myrtle were planted on the inner court with mossy rocks, small artificial hills, glass rocks, flower pots. There were rectangular ponds, while breeding deer, dove, rooster, and cranes. Fourth, landscape elements were enjoyed as metaphysical symbolic landscape by anthropomorphism, such as (1) gentlemen and loyalty, (2) wealth and prosperity, (3) Taoist hermit and poetical life, (4) reclusion and seclusion, (5) filial piety, virtue, introspection, etc. In other words, the garden presented a variety of gardening culture appreciating meaningful landscape, such as investigation of things, reclusion and seclusion, and building orientation of a fairyland yearning eternal youth and Mureungdowon(Taoist Arcadia) by making a garden blending beautiful flowers and trees, with precious birds and animals. Fifth, there were many landscape appreciation schemes, such as Angkyung(looking-up), Bukyung(looking-down), Jeokyung(looking-under), Chakyung(bringing outer space into inside), Yookyung(flower viewing), Yojeong(walking around the garden enjoying flowers), Hwasaekhyangbyuk(flower gardening), and Garden appreciation enjoying landscape through time and seasons with different inspirations.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.118-129
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• 2011

This study is about the governor general's official residence and its garden in Yongsan that were constructed during the Japanese occupational time. The garden design drawing was also made while planning such Neo-Baroque style building, and it contains particular information of the garden unlike the other existing landscape drawings. The content of garden translated and landscape historical value drawn out by analysis of garden drawings, press articles and literatures are as follows; First, such governor general's official residence garden in Yongsan is likely to be the Korean first western style landscape form. For, from the point that it was completely constructed together with such official residential building in 1909, its construction time should be before that of the garden of Seokjojeon, Deoksu Palace, which was constructed in 1911. Second, it shows the garden style and garden planting factors introduced together with the modern architecture then. Such garden planting factors are placed from the center axis of the garden that is connected to the center of the building and monument as well. Such style and factors cover and show the flower bed appearing in Baroque style gardens, the monument that forms Vista playing the center of audience's vision, water space that is placed symmetrically against the axis, planting pattern that emphasizes the plants' space, flower bed shape and axis, and what kinds of plants were introduced then. Third, it shows the using pattern of western style gardens. Western style garden parties used to take in place in this garden while official dinner and reception were held in the evening in the official residence. Fourth, it shows the historical value as a modern landscape drawing, which is the Korean first landscape drawing that shows the plants' names and planting techniques marking the current height and planned height for change of topography and water system as a water landscape factor. That is, this drawing has the value that it was upgraded from the other existing ones that expressed only simple plants' symbols or flower bed shapes. I, therefore, hope that the studies on the modern landscape would be getting wider by excavation of new historical records in the future.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.27-39
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• 2011

The study on Musan twelve peaks of Yongho garden in Jinju, Gyeongnam was anticipated to provide data and implication for reproducing similar spaces and modern changes in terms of design factor since it is the prototype of traditional mount for overcoming monotonous geographical features and intriguing changes and interests. The study analyzed and interpreted the symbolism of twelve peaks, principles of space composition and function and effect of visual construction that were pursued by the builder in terms of landscape view, which results are as following. The center of Yongho garden, Yonghoji(龍虎池) is a typical man-made pond for a supportive feng shui feature. It is a supporting equipment to complete the state of feng shui, and the result of strengthening the completion through the connection with the dragon-related name of the place. The shape of Musan twelve peaks looks like an oval form of Geumseongsan(金星山), 2~3.5m in height and 6~12m in diameter. Peaks are estimated as 1.5~3.7m(2.4m in average) in height, $35{\sim}138m^2$($73.4m^2$ in average) in area, and $30.7{\sim}115.0m^3$($62.5m^3$ in average) in volume. Given that Yonghojeong(龍虎亭), Soseon(小船), the site of main building and Yongsanjae(龍山齋) stand in line, Yonghoji was presumed as the state of enlightenment through ascribing the meaning to virtue and secularity. For the intention of realizing Musan twelve peaks, the builder probably had mounted twelve peaks forming the body of dragons with crossing the point corresponding to a head of tiger, and located Musan twelve peaks and Yonghojeong with a representation of dragons holding Cintamani rising into the sky in the center. The middle area near Musan twelve peaks surrounded by peaks like Geumseongsan running north and south shows a multi-structure of multilayer, maintaining the similarity centering on Yonghoji. It is considered the intention of mount planned at the time of Musan twelve peaks construction, caused by similar form harmony. Internalization of progressive realization through concealment and exposure, enframement effect and spatial order like prospect-refuge theory in the mount of Musan twelve peaks is considered the reflection of the intention to increase depth of the view and expectancy through the various degree of exposure and surroundings of each peak and the colorful combination of viewing and shutting. The "closed view" by Musan twelve peaks creates interesting, vivid and attractive recognition of the view, which is more effective in bringing depth of the view and interests in terms of the geographical design, particularly the area around Yonghoji. Moreover, it was identified that the combination of peaks can be formed resulted from the view configuration concerning the location through multilayer effect reveals an island through the other one when viewed from Yonghojeong.

• Korean Journal of Heritage: History & Science
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• v.54 no.2
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• pp.154-169
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• 2021

The establishment of the Bronze Age is one of the most important achievements suggested by Korean archaeology shortly after liberation. There is no doubt that Moo-Byung Yoon is the representative figure, who refuted the ambiguous Eneolithic age (金石倂用期) created by Japanese scholars and settled the concept of the Bronze Age. In this article, the author takes a new look at Yoon's institutional role in studying the Bronze Age in Korea. Until now, Yoon's representative achievement has been his typology of the Slender dagger of the Korean Peninsula. However, it is not less important that Yoon also established the Bronze Age concept with the excavation of a dolmen and a Bronze Age subterranean dwelling in Oksok-ni, Paju during the 1960s. Of course, it was not a personal assignment for Yoon. He was aided by Prof. Kim Won-Yong's work, who had introduced newly excavated materials from North Korea and China; these materials gave some insight for establishing the Bronze Age concepts in the 1960 and 1970s. Kim's suggestion about the possibility of a Korean Bronze Age led to Yoon's refined typological study on Korea's bronze wares. However, Yoon's excessive schematic classification of artifacts and reliance on the Japanese chronology became an obstacle for making the Korean Bronze Age isolated from East Asia. As a result, it is regrettable that his research led to the "cultural lag" phenomenon of Bronze Age research. Meanwhile, Japanese archaeology, which had influenced Yoon, also faced a major change. In 2003, the Japanese archaeological community revised the Yayoi culture's beginning around the 1,000 BC. This means a shift in the perception that we should understand Japan's Bronze Age in the context of the East Asian continent. Of course, it is not appropriate to reevaluate or denigrate Yoon's research from the current view. Rather, it is necessary to recognize the limitations of Yoon's time and present a new path to research by combining the archaeological tradition of refining research on the relics he maintained with a new chronological view and a macro view of East Asian archaeology. This is why we should take a new glimpse into Yoon's research.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.2
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• pp.37-45
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• 2022

A simplified model using the lifetime distribution has been presented to estimate the Mean Residual Life (MRL) of rubble-mound breakwaters, which is not like a stochastic process model based on time-dependent history data to the cumulative damage progress of rubble-mound breakwaters. The parameters involved in the lifetime distribution can be easily estimated by using the upper and lower limits of lifetime and their likelihood that made a judgement by several experts taking account of the initial design lifetime, the past sequences of loads, and others. The simplified model presented in this paper has been applied to the rubble-mound breakwater with TTP armor layer. Wiener Process (WP)-based stochastic model also has been applied together with Monte-Carlo Simulation (MCS) technique to the breakwater of the same condition having time-dependent cumulative damage to TTP armor layer. From the comparison of lifetime distribution obtained from each models including Mean Time To Failure (MTTF), it has found that the lifetime distributions of rubble-mound breakwater can be very satisfactorily fitted by log-normal distribution for all types of cumulative damage progresses, such as exponential, linear, and logarithmic deterioration which are feasible in the real situations. Finally, the MRL of rubble-mound breakwaters estimated by the simplified model presented in this paper have been compared with those by WP stochastic process. It can be shown that results of the presented simplified model have been identical with those of WP stochastic process until any ages in the range of MTT F regardless of the deterioration types. However, a little of differences have been seen at the ages in the neighborhood of MTTF, specially, for the linear and logarithmic deterioration of cumulative damages. For the accurate estimation of MRL of harbor structures, it may be desirable that the stochastic processes should be used to consider properly time-dependent uncertainties of damage deterioration. Nevertheless, the simplified model presented in this paper can be useful in the building of the MRL-based preventive maintenance planning for several kinds of harbor structures, because of which is not needed time-dependent history data about the damage deterioration of structures as mentioned above.

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.185-200
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• 2022

The risk of various hazardous substances in aquatic environment comprises not only the concentration of substances in the environmental medium but also their accumulation in fish through complex food web and the health risks to humans through the fish. In Korea, the monitoring of residual toxicant in aquatic ecosystems began in 2016 following the enforcement of the Acts on registration and evaluation for the management of chemicals used in daily life (consumer chemical products), and attention has been paid to potentially hazardous substances attributed to them. Recently, studies have been carried out to investigate the distribution of these hazardous substances in the ecosystem and calculate their emission factors. These include the accumulation and transport of substances, such as detergents, dyes, fragrances, cosmetics, and disinfectants, within trophic levels. This study summarizes the results of recently published research on the inflow and distribution of hazardous substances from consumer chemical products to the aquatic environment and presents the scientific implication. Based on studies on aquatic environment monitoring techniques, this study suggests research directions for monitoring the residual concentration and distribution of harmful chemical substances in aquatic ecosystems. In particular, this study introduces the directions for research on trophic position analysis using compound specific isotope analysis and trophic magnification factors, which are needed to fulfill the contemporary requirements of selecting target fish based on the survey of major fish that inhabit domestic waters and assessment of associated health risk. In addition, this study provides suggestions for future biota monitoring and chemical research in Korea.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.4
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• pp.49-56
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• 2023

This study analyzes the entirety of Okhojeongdo's content found in the Punggojip, written by Kim Jo-Sun, who created Okhojeong. Through an examination of the literature confirming Okhojeong within the Punggojip, the study compares the existing research with the Okhojeongdo's content. Additionally, it clarifies the relationships between the disciple, the garden, and related historical facts. The results are as follows. First, Kim Jo-Sun, who created Okhojeong, had a strong literary inclination, which made it relatively easy to estimate the original form of the garden, as he expressed detailed content related to the design and management of the garden. Second, the historical dating of the creation of Okhojeong was previously estimated to be around 1815 based on the inscriptions on the Eulhaebyeok. However, it is more appropriate to revise this to 1804, as revealed by Lee Sung-min, who discovered records in Dongseonggyoyeojip, indicating that Kim Jo-Sun purchased the Jang's house. Third, Kim Jo-Sun's literary hobby, as depicted in Punggojip, closely followed Chinese classics. However, the part about creating the garden is supported by factual and garden archaeological records, giving it inherent value. Regarding the expansion of the garden site, it is estimated that the southern boundary of Okhojeong was extended by about half a unit(kan; 間) through a transfer from Kim saeng Saho. Various additions, stone statues, peculiar rocks, ornamental trees, and accompanying elements are found throughout the garden. Particularly noteworthy are the techniques and aesthetics of creating a stone pagoda, and there are mentions of transplanting young pine trees with professional insights. The love for harmony and elegance in the garden is woven throughout the poetry. Additionally, the process of selecting the location for Okhojeong, the understanding of the terrain and topography, the assessment of existing vegetation, the process of cutting down trees and selecting the soil, the construction of houses with tiles and thatched roofs all contribute to demonstrating the comprehensive stages of creating Okhojeong, providing insight into the location and construction process of the Sanbanru pavilion, showcasing the archaeological value of the garden. A follow-up study is needed to excavate more information about the original form of Okhojeong garden through the interpretation of the collections of the literary works of the influential figures introduced in Punggojip in the future.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.59-77
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• 2012

This study focuses on predicting which firms will increase capital by issuing new stocks in the near future. Many stakeholders, including banks, credit rating agencies and investors, performs a variety of analyses for firms' growth, profitability, stability, activity, productivity, etc., and regularly report the firms' financial analysis indices. In the paper, we develop predictive models for rights issues using these financial analysis indices and data mining techniques. This study approaches to building the predictive models from the perspective of two different analyses. The first is the analysis period. We divide the analysis period into before and after the IMF financial crisis, and examine whether there is the difference between the two periods. The second is the prediction time. In order to predict when firms increase capital by issuing new stocks, the prediction time is categorized as one year, two years and three years later. Therefore Total six prediction models are developed and analyzed. In this paper, we employ the decision tree technique to build the prediction models for rights issues. The decision tree is the most widely used prediction method which builds decision trees to label or categorize cases into a set of known classes. In contrast to neural networks, logistic regression and SVM, decision tree techniques are well suited for high-dimensional applications and have strong explanation capabilities. There are well-known decision tree induction algorithms such as CHAID, CART, QUEST, C5.0, etc. Among them, we use C5.0 algorithm which is the most recently developed algorithm and yields performance better than other algorithms. We obtained data for the rights issue and financial analysis from TS2000 of Korea Listed Companies Association. A record of financial analysis data is consisted of 89 variables which include 9 growth indices, 30 profitability indices, 23 stability indices, 6 activity indices and 8 productivity indices. For the model building and test, we used 10,925 financial analysis data of total 658 listed firms. PASW Modeler 13 was used to build C5.0 decision trees for the six prediction models. Total 84 variables among financial analysis data are selected as the input variables of each model, and the rights issue status (issued or not issued) is defined as the output variable. To develop prediction models using C5.0 node (Node Options: Output type = Rule set, Use boosting = false, Cross-validate = false, Mode = Simple, Favor = Generality), we used 60% of data for model building and 40% of data for model test. The results of experimental analysis show that the prediction accuracies of data after the IMF financial crisis (59.04% to 60.43%) are about 10 percent higher than ones before IMF financial crisis (68.78% to 71.41%). These results indicate that since the IMF financial crisis, the reliability of financial analysis indices has increased and the firm intention of rights issue has been more obvious. The experiment results also show that the stability-related indices have a major impact on conducting rights issue in the case of short-term prediction. On the other hand, the long-term prediction of conducting rights issue is affected by financial analysis indices on profitability, stability, activity and productivity. All the prediction models include the industry code as one of significant variables. This means that companies in different types of industries show their different types of patterns for rights issue. We conclude that it is desirable for stakeholders to take into account stability-related indices and more various financial analysis indices for short-term prediction and long-term prediction, respectively. The current study has several limitations. First, we need to compare the differences in accuracy by using different data mining techniques such as neural networks, logistic regression and SVM. Second, we are required to develop and to evaluate new prediction models including variables which research in the theory of capital structure has mentioned about the relevance to rights issue.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.173-198
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• 2020

For a long time, many studies have been conducted on predicting the success of campaigns for customers in academia, and prediction models applying various techniques are still being studied. Recently, as campaign channels have been expanded in various ways due to the rapid revitalization of online, various types of campaigns are being carried out by companies at a level that cannot be compared to the past. However, customers tend to perceive it as spam as the fatigue of campaigns due to duplicate exposure increases. Also, from a corporate standpoint, there is a problem that the effectiveness of the campaign itself is decreasing, such as increasing the cost of investing in the campaign, which leads to the low actual campaign success rate. Accordingly, various studies are ongoing to improve the effectiveness of the campaign in practice. This campaign system has the ultimate purpose to increase the success rate of various campaigns by collecting and analyzing various data related to customers and using them for campaigns. In particular, recent attempts to make various predictions related to the response of campaigns using machine learning have been made. It is very important to select appropriate features due to the various features of campaign data. If all of the input data are used in the process of classifying a large amount of data, it takes a lot of learning time as the classification class expands, so the minimum input data set must be extracted and used from the entire data. In addition, when a trained model is generated by using too many features, prediction accuracy may be degraded due to overfitting or correlation between features. Therefore, in order to improve accuracy, a feature selection technique that removes features close to noise should be applied, and feature selection is a necessary process in order to analyze a high-dimensional data set. Among the greedy algorithms, SFS (Sequential Forward Selection), SBS (Sequential Backward Selection), SFFS (Sequential Floating Forward Selection), etc. are widely used as traditional feature selection techniques. It is also true that if there are many risks and many features, there is a limitation in that the performance for classification prediction is poor and it takes a lot of learning time. Therefore, in this study, we propose an improved feature selection algorithm to enhance the effectiveness of the existing campaign. The purpose of this study is to improve the existing SFFS sequential method in the process of searching for feature subsets that are the basis for improving machine learning model performance using statistical characteristics of the data to be processed in the campaign system. Through this, features that have a lot of influence on performance are first derived, features that have a negative effect are removed, and then the sequential method is applied to increase the efficiency for search performance and to apply an improved algorithm to enable generalized prediction. Through this, it was confirmed that the proposed model showed better search and prediction performance than the traditional greed algorithm. Compared with the original data set, greed algorithm, genetic algorithm (GA), and recursive feature elimination (RFE), the campaign success prediction was higher. In addition, when performing campaign success prediction, the improved feature selection algorithm was found to be helpful in analyzing and interpreting the prediction results by providing the importance of the derived features. This is important features such as age, customer rating, and sales, which were previously known statistically. Unlike the previous campaign planners, features such as the combined product name, average 3-month data consumption rate, and the last 3-month wireless data usage were unexpectedly selected as important features for the campaign response, which they rarely used to select campaign targets. It was confirmed that base attributes can also be very important features depending on the type of campaign. Through this, it is possible to analyze and understand the important characteristics of each campaign type.