• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.109-121
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• 2001

Water environment and freshwater algae were studied in the upstream of the Tamjin River Dam. Among the environmental factors, DO concentration in the Tamjin River ranged from 9.0 mg $O_2/l$ to 9.2 mg $O_2/l$, pH from 7.0 to 7.1 and conductivity from $98{\mu}S/cm$ to $100{\mu}S/cm$. Average concentration of $NH_4$ and $NO_3$ ranged from $40{\mu}g\;N/l$ to $56{\mu}g\;N/l$ and from $489{\mu}g\;N/l$ to $611{\mu}g\;N/l$, respectively. $NO_3$ was more plentiful above 9~15 fold than that of $NH_4$. Average concentrations of soluble reactive phosphorus and soluble reactive silicon were $2{\mu}g\;P/l$ and 1.6 mg Si/l, respectively. Particulaly, Si nutrient increased by heavy rain events during summer season. The ratios of N/P and Si/P ranged from 248 to 261 and from 640 to 740, respectively. It is assumed that P would be limiting nutrient on the freshwater algal growth. Average content of planktonic chlorophyll-a ranged from $5{\mu}g/l$ to $13{\mu}g/l$. Mean contents of chlorophyll-a, phaeo-pigment and ash-free dry matter of periphyton were $50.3mg/m^2$, $11.9mg/m^2$, $11.5g/m^2$ in the main stream and $30.1mg/m^2$, $5.6mg/m^2$, $7.8g/m^2$ in the tributary. By comparison of the epilithon biomass, the main stream was higher with 1.5~2.1 fold than the tributary. The impotant algae were composed of diatom Achnanthes linearis, A. minutissima, Fragilaria crotonensis, Gomphonema gracile, Tabellaria flocculosa and blue-green algae Microcystis aeruginosa. In the relative abundance of the phytoplankton and epilithon, the serial dominance were diatom > green algae > blue-green algae, and diatoms were very abundant in comparison with other algal phylum.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.21-29
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• 1999

This study was carried out to determine the promising method for the production of mother bulbs using garlic bulbs at the experimental field of Ange high school, Eusung in Korea from 1996 to 1998. The bulbs and bulbils were taken from a local cultivar 'Eusung' garlic. The growth of bulbil and yield potential were compared with different harvesting times and cultivation methods of bulbil. The harvesting time of bulbils which were capable of producing the mother bulbs was ranged from 15 days to 30 days after the emergence of flower stalks. The best results based on the yield and number of bulbs were obtained from the bulbils sampled at the just before garlic harvesting, 30 days after flower-stalk emergence. The mulching with transparent polyethylene(PE) film in bulbil cultivation was more effective for the plant growth and bulb formation than that with black PE film. The PE mulching from 30 days after seeding of bulbils to 30 days (late-April) before bulb harvesting was the moot effective for the increase of bulb yield. In the cultivation of garlic bulbils, application of lime (150 kg/10a) and compost (3,000 kg/10a) without any chemical fertilizers produced more bulbs in comparison with the standard level of fertilizer (N - $P_2O_5$ - $K_2O$ - compost - lime = 24.8 - 8.0 - 19.2 - 3,000 - 150 kg/10a). It was determined that the involucre seeding and assemble seeding of bulbils was effective and labour-saving methods for the production of mother bulbs from garlic bulbils. Input of labour force for the involucre seeding was decreased up to 61% as compared with the conventional drill seeding of bulbils. Mean yield from the cultivation of bulbil-derived single cloves was remarkably increased up to 95% in comparison with that of the common cloves. The larger size of single clove produced more yields, and the optimum planting density of single clove was $20{\times}10cm$. The cloves differentiated directly from bulbil showed to have higher yield potential than that from common cloves.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.219-227
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• 2006

Objective: To evaluate the impact of endometriosis on IVF-ET cycles and to compare IVF outcomes between stage I/II and stage III/IV endometriosis. Methods: We analyzed 697 patients (1,199 cycles) with endometriosis (stage I-II:638 cycles, stage III-IV: 561 cycles) and 325 pts (459 cycles) with tubal factor as controls between January 1994 and April 2004. Pts with endometriosis were diagnosed by laparoscopy and medical and surgical treatment were done in 353 cycles (55.3%) and 466 cycles (83.1%) of stage I-ll/stage III-IV endometriosis. Cycles with age>35 years or FSH>20 miU/mL or severe male factor infertility were excluded. Results: The number of retrieved oocytes ($9.97{\pm}7.2$ vs. $13.4{\pm}7.9$ (p<0.0001 )), total number of embryos ($6.5{\pm}4.8$ vs. $9.1{\pm}5.6$ (p<0.0001)), and good quality embryos ($2.43{\pm}1.6$ vs. $2.74{\pm}1.7$ (p=0.013)) significantly decreased in stage III-IV endometriosis than in control. But pregnancy rate of stage III-IV endometriosis was comparable with control (35.7% vs. 36.8%). Fertilization rate and number of total embryos were lower in stage I-II endometriosis than in control ($64.8{\pm}22.9$ vs. $70.8{\pm}20.8$ (p<0.0001), $7.6{\pm}5.0$ vs. $9.1{\pm}5.6$ (p<0.0001)). In patients with medical and surgical treatment of endometriosis, pregnancy rate and live birth rate was significantly lower in stage I-II than in stage III-IV endometriosis (29.2 vs. 36.2 (%), p=0.045, 23.9 vs. 31.5 (%), p=0.043). There was no difference in the mean age, but the duration of infertility was significantly longer ($56.5{\pm}26.3$ vs. $46.9{\pm}25.8$ (mon), p<0.0001) and fertilization rate was lower ($64.7{\pm}23.3$ vs. $70.5{\pm}22.7$ (%), p=0.001) in stage I-II than stage III-IV endometriosis. Conclusion: We suggest that IVF should be considered earlier in patients with minimal to mild endometriosis because of significantly decreased fertilization rates.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.107-116
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• 2000

This study is of investigation of refraction error, spectacles and contact lenses wearing state, visual acuity test, ophthalmologic common sense and vision care, using questionnaire study for 850 male and female high school students in Kunsan and Chongup City, Cheolla North Province. The results are as follows: 1. Among the 823 answerers, emmetropia is 18%, myopia is 55.1%, and hyperopia is 7%, respectively. 2. Among the 837 answerers, 381 students(45.5%) wear spectacles or contact lenses. Among the 381 students who wear spectacles or contact lenses, 78% wear only spectacles, 4% wear only contact lenses and 18% wears spectacles sometimes or contact lenses sometimes. 3. The places where the answerers had visual acuity test to wear spectacles or contact lenses are optical shop(64.7%), hospital(28.3%), unchecked(4.2%) and the others(2.7%). The places where the answerers had visual acuity test to change their spectacles or contact lenses are optical shop(82%), hospital(28.3%), unchecked(6.6%) and the others(1.9%). 4. As for the period of visual acuity test, from 6 months to one year is 54.1%, within 6 months is 9.2%, from one year to two years is 29.5%, and more than two years is 7.2%. 5. The contact lens wearers purchased their contact lenses at optical shops(94%) and at hospital(6%). 6. The reasons why they like wearing contact lenses are their appearance(51.2%), convenience in physical excercise(23.l%), lighter weight than spectacles(9.8%) and the others(15.7%). 7. As for the spectacles frame they like, plastic frame is 24.4%, gold or silver plated frame is 43.4%, coloured frame is 32.1%. 8. As for the considerations in choosing spectacles frame, their design is 37%, their quality is 36%, their price is 14.7% and their brand is 12.5%. 9. As for the period for changing spectacles, 10.5% is within 6 months, 57.3% is 6months to 1 year, 22.4% is 1 year to 2 months and 9.6% is more than 2 years. 10. There is a false fact, in Korea, that even though one has his poor eyesight, not wearing custom is helpful for the eyesight recovery. As for their conviction of the false fact, 10.5% of the answerers have 100% conviction, 22.5% of them have 22.5% conviction, 49.5% of them have 50% conviction and 17.5% of them don't have any conviction. 11. 48.5% of the answerers are interested in their vision care while 51.5% of them are not interested at all. As for the way of vision care, the vision-care way to keep enough distant when they are watching TV, when they are using computers and when they are reading, is 49% while the vision-care way such as hypogastric breathing or eye massage is 11%. And alimentotherapy is 4% and the rest who are not interested in vision care is 36%. 12. When they come to an age, the students who want vision correction operation are 45.9% while the students who do not want it are 27%. The students who do not have any idea about the operation are 27.1%

• Journal of Nutrition and Health
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• v.53 no.5
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• pp.488-502
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• 2020

Purpose: This study examined the factors influencing Nutrition Quotient for adults (NQ-A), focusing on workers in the manufacturing industry. Methods: The participants were 738 industrial workers in Gwangju. Their dietary information was analyzed using a questionnaire of NQ-A, which consisted of 21 checklist items and the general characteristics of the subjects. The scores of NQ-A and its 4 factors (balance, moderation, diversity, and dietary behavior) were calculated according to the general characteristics of subjects. The data were analyzed using a χ² test, t-test, correlation, and multiple regression using SPSS 21.0 program. Results: The mean NQ-A score was 45.3 for the total subjects, indicating a low grade. Non-shift workers showed significantly higher scores for balance, diversity, and moderation factors than shift workers. Forty-three (8.7%) shift workers and 123 (50.8%) non-shift workers had good NQ-A scores, whereas 453 (91.3%) shift workers and 119 (49.2%) non-shift workers required monitoring for nutrition. The significant influencing factors of NQ-A were the working pattern (p < 0.001), gender (p < 0.001), family composition (p < 0.001), age (p < 0.001), and household income (p < 0.001). As a result of multiple regression analysis, there was a significant difference in the NQ-A score for moderation (F = 141.930, p < 0.001), diversity (F = 98.998, p < 0.001), balance (F = 52.329, p < 0.001), and dietary behavior (F = 12.895, p < 0.001). As a result, shift work and gender had the greatest influence on the balance (β = -0.372, p < 0.001), diversity (β = -0.316, p < 0.001), and moderation (β = -0.507, p < 0.001) factors in NQ-A. Gender had the most influence on the dietary behavior in NQ-A. Conclusion: Shift work and gender were significant factors affecting NQ-A. To manage workers' health better, it will be necessary to prepare a nutrition education program according to the type of working pattern and gender.

• The Journal of Industrial Distribution & Business
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• v.1 no.1
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• pp.5-12
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• 2010

The retail business of drugstore was introduced to Korea for the first time 10 years ago. Since Olive Young introduced a retail store in the name of drugstore in 1999 for the first time in Korea, new distribution channel combining drugstore, cosmetic products and dairy products, etc has been made. At initial stage, the new distribution channel grew up slowly because of low specialty and economic stagnation. However, the three big distribution channels, that is to say, Olive Young (CJ), Watsons (GS) and W Store (Kolon Well Care), etc, were established to produce new distribution system following large-scaled discount stores as well as convenience stores. The purpose of the study is to investigate ways making Korean style drugstore be new retail business in addition to traditional markets, department stores, E-Mart and other general super markets and to examine problems preventing the drugstore from being promoted and to find out solutions. The speciality retailers that is called a category killer attacking department stores as well as marts is expanding market quickly. New consumption trend that gives priority to wellbeing is being expanded in accordance with high level of standards of living life: The drugstore is thought to be new alternative of distribution because it keeps special products. Young ladies who are main customers of drugstores respond to the trend sensitively to have more buying power that is thought to be promising. And, consumers' desire has become concrete and special. This is because consumers want not only convenient shopping but also special shopping system that is current trend. These days, so called Multi-shop and Total shop and other special shops have been recently opened. Special multi-shop has been concentrated on fashion product and miscellaneous goods so far: Health total wellbeing shop shall be popular in accordance with wellbeing trends. Drugstores can play an important role. Drugstores were opened for the first time ten years ago. In particular, Olive Young succeeded in going into the black after making efforts for a long time by many persons. Drugstores could succeed in the business owing to many persons in the past as well as customers who liked drugstores. However, drugstores once lost ways and recorded poor business results. The three drugstores, that is to say, Olive Young, Watsons making efforts to go into the black and W-Store pursuing traditional drugstore shall compete each other and make effort to satisfy customers' desire. In that way, the three drugstores can be assured of present business as well as future business. The consumers' demand trend has become special at sub-division so that drugstores that can satisfy the demand can succeed in the business. Large businesses may be more interested in the 4th generation retail business to produce good income and to have bright future. Drugstore business and market are likely to expand and develop owing to large business' participation in drugstore business. Drugstores expanded shop at Seoul and Gyeonggi-do until middle of 2000. Drugstore business at station sphere in Seoul and Gyeonggi-do that have high ratio of temporary population has low customer loyalty to have limitation on continuous growth. Since 2009, drugstores have opened new shops at local towns: From the year of 2010, drugstores need to establish multiple shop strategy by accelerating business speed and to allow customers to drop in the shop anywhere in the nation and to enter consumers' life deeply, so that they can strengthen business base definitely. Drugstores need to have price competitiveness to have multiple shop opening strategy and to satisfy consumers and to supply high quality services that is future subject to solve. And, Olive Young and Watsons that are Korean style drugstore need to keep system in order and to strengthen substance as Korean style drugstore and to expand marketing, so that they can get business outcome within 5 years that was done 10 years before and they become the 4th generation retail business. The study had difficulties at collecting material from the three drugstore because of poor cooperation. And, the author had great difficulty at collecting statistical material that was made in disorder. Further effort is needed considering such problems.

• 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.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.1-18
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• 2015

Collaborative filtering(CF) algorithm has been popularly used for recommender systems in both academic and practical applications. A general CF system compares users based on how similar they are, and creates recommendation results with the items favored by other people with similar tastes. Thus, it is very important for CF to measure the similarities between users because the recommendation quality depends on it. In most cases, users' explicit numeric ratings of items(i.e. quantitative information) have only been used to calculate the similarities between users in CF. However, several studies indicated that qualitative information such as user's reviews on the items may contribute to measure these similarities more accurately. Considering that a lot of people are likely to share their honest opinion on the items they purchased recently due to the advent of the Web 2.0, user's reviews can be regarded as the informative source for identifying user's preference with accuracy. Under this background, this study proposes a new hybrid recommender system that combines with users' review mining. Our proposed system is based on conventional memory-based CF, but it is designed to use both user's numeric ratings and his/her text reviews on the items when calculating similarities between users. In specific, our system creates not only user-item rating matrix, but also user-item review term matrix. Then, it calculates rating similarity and review similarity from each matrix, and calculates the final user-to-user similarity based on these two similarities(i.e. rating and review similarities). As the methods for calculating review similarity between users, we proposed two alternatives - one is to use the frequency of the commonly used terms, and the other one is to use the sum of the importance weights of the commonly used terms in users' review. In the case of the importance weights of terms, we proposed the use of average TF-IDF(Term Frequency - Inverse Document Frequency) weights. To validate the applicability of the proposed system, we applied it to the implementation of a recommender system for smartphone applications (hereafter, app). At present, over a million apps are offered in each app stores operated by Google and Apple. Due to this information overload, users have difficulty in selecting proper apps that they really want. Furthermore, app store operators like Google and Apple have cumulated huge amount of users' reviews on apps until now. Thus, we chose smartphone app stores as the application domain of our system. In order to collect the experimental data set, we built and operated a Web-based data collection system for about two weeks. As a result, we could obtain 1,246 valid responses(ratings and reviews) from 78 users. The experimental system was implemented using Microsoft Visual Basic for Applications(VBA) and SAS Text Miner. And, to avoid distortion due to human intervention, we did not adopt any refining works by human during the user's review mining process. To examine the effectiveness of the proposed system, we compared its performance to the performance of conventional CF system. The performances of recommender systems were evaluated by using average MAE(mean absolute error). The experimental results showed that our proposed system(MAE = 0.7867 ~ 0.7881) slightly outperformed a conventional CF system(MAE = 0.7939). Also, they showed that the calculation of review similarity between users based on the TF-IDF weights(MAE = 0.7867) leaded to better recommendation accuracy than the calculation based on the frequency of the commonly used terms in reviews(MAE = 0.7881). The results from paired samples t-test presented that our proposed system with review similarity calculation using the frequency of the commonly used terms outperformed conventional CF system with 10% statistical significance level. Our study sheds a light on the application of users' review information for facilitating electronic commerce by recommending proper items to users.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.23-45
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• 2020

Big data is creating in a wide variety of fields such as medical care, manufacturing, logistics, sales site, SNS, and the dataset characteristics are also diverse. In order to secure the competitiveness of companies, it is necessary to improve decision-making capacity using a classification algorithm. However, most of them do not have sufficient knowledge on what kind of classification algorithm is appropriate for a specific problem area. In other words, determining which classification algorithm is appropriate depending on the characteristics of the dataset was has been a task that required expertise and effort. This is because the relationship between the characteristics of datasets (called meta-features) and the performance of classification algorithms has not been fully understood. Moreover, there has been little research on meta-features reflecting the characteristics of multi-class. Therefore, the purpose of this study is to empirically analyze whether meta-features of multi-class datasets have a significant effect on the performance of classification algorithms. In this study, meta-features of multi-class datasets were identified into two factors, (the data structure and the data complexity,) and seven representative meta-features were selected. Among those, we included the Herfindahl-Hirschman Index (HHI), originally a market concentration measurement index, in the meta-features to replace IR(Imbalanced Ratio). Also, we developed a new index called Reverse ReLU Silhouette Score into the meta-feature set. Among the UCI Machine Learning Repository data, six representative datasets (Balance Scale, PageBlocks, Car Evaluation, User Knowledge-Modeling, Wine Quality(red), Contraceptive Method Choice) were selected. The class of each dataset was classified by using the classification algorithms (KNN, Logistic Regression, Nave Bayes, Random Forest, and SVM) selected in the study. For each dataset, we applied 10-fold cross validation method. 10% to 100% oversampling method is applied for each fold and meta-features of the dataset is measured. The meta-features selected are HHI, Number of Classes, Number of Features, Entropy, Reverse ReLU Silhouette Score, Nonlinearity of Linear Classifier, Hub Score. F1-score was selected as the dependent variable. As a result, the results of this study showed that the six meta-features including Reverse ReLU Silhouette Score and HHI proposed in this study have a significant effect on the classification performance. (1) The meta-features HHI proposed in this study was significant in the classification performance. (2) The number of variables has a significant effect on the classification performance, unlike the number of classes, but it has a positive effect. (3) The number of classes has a negative effect on the performance of classification. (4) Entropy has a significant effect on the performance of classification. (5) The Reverse ReLU Silhouette Score also significantly affects the classification performance at a significant level of 0.01. (6) The nonlinearity of linear classifiers has a significant negative effect on classification performance. In addition, the results of the analysis by the classification algorithms were also consistent. In the regression analysis by classification algorithm, Naïve Bayes algorithm does not have a significant effect on the number of variables unlike other classification algorithms. This study has two theoretical contributions: (1) two new meta-features (HHI, Reverse ReLU Silhouette score) was proved to be significant. (2) The effects of data characteristics on the performance of classification were investigated using meta-features. The practical contribution points (1) can be utilized in the development of classification algorithm recommendation system according to the characteristics of datasets. (2) Many data scientists are often testing by adjusting the parameters of the algorithm to find the optimal algorithm for the situation because the characteristics of the data are different. In this process, excessive waste of resources occurs due to hardware, cost, time, and manpower. This study is expected to be useful for machine learning, data mining researchers, practitioners, and machine learning-based system developers. The composition of this study consists of introduction, related research, research model, experiment, conclusion and discussion.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.86-97
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• 2015

"The Jayeon Madang Development Project("JMDP")" is a project being promoted by the Ministry of Environment to create a cultural space and a natural rest area within the city. Abuksan, located at Abuksan in Gyeongsangnam-do Miryang-si Naeil-dong, has suffered a substantial amount of environmental degradation over time, so the need for ecological restoration made it a natural choice for the location of the JMDP's site. The purpose of this study is to examine ecological restoration design strategies used in Abuksan as part of the JMDP using system dynamics. The national archery center, hole, and arable land sites are key restoration areas in Abuksan that have faced with ecological problems. In this study, we identified the status of each site, determined key strategies being implemented, and designed based on the strategies implemented up to this point for solving problems associated with each sites through the use of causal loop diagrams. The results of the causal loop diagram analysis are as follows. The national archery center site was designed around strategies including planting green manure crops and introducing hugelkultur to reduce soil acidification and green network degradation. The hole site was designed as a constructed wetland based on the emergence of hygropreference vegetation, hydrated by rainwater collected at the bottom of hole, ecological and cultural benefits of such an environment. The arable land site restoration design was built around planting native vegetation on one part of the arable land site after soil quality improved and around restoration of grassland and a dry wetland on the other part of the site to reduce soil acidification, erosion, and green network degradation. This study is a significant attempt to apply principles of system dynamics to ecological restoration by providing the design strategies using comprehension of some problems in the ecosystem feedback loops, which has not been used before in general design processes for ecological restoration.