• Journal of Information Technology Services
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• v.22 no.4
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• pp.123-140
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• 2023

In recent times, the global economy has been subject to increasing volatility, which has made it considerably more difficult to accurately predict economic indicators compared to previous periods. In response to this challenge, the present study conducts an exploratory investigation that aims to predict the Business Survey Index (BSI) by leveraging data mining techniques on both structured and unstructured data sources. For the structured data, we have collected information regarding foreign, domestic, and industrial conditions, while the unstructured data consists of content extracted from newspaper articles. By employing an extensive set of 44 distinct data mining techniques, our research strives to enhance the BSI prediction accuracy and provide valuable insights. The results of our analysis demonstrate that the highest predictive power was attained when using data exclusively from the t-1 period. Interestingly, this suggests that previous timeframes play a vital role in forecasting the BSI effectively. The findings of this study hold significant implications for economic decision-makers, as they will not only facilitate better-informed decisions but also serve as a robust foundation for predicting a wide range of other economic indicators. By improving the prediction of crucial economic metrics, this study ultimately aims to contribute to the overall efficacy of economic policy-making and decision processes.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.235-246
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• 2021

This study investigated the impact of baseflow on fish community in the Ungcheon stream (16.5 km long) located downstream of the Boryeong Dam, Korea. Based on field monitoring, there were five dominant fish species in the Ungcheon Stream accounting for 75% of the total fish community: Zacco platypus, Zacco koreanus, Tridentiger brevispinis, Rhinogobius brunneus, and Pungtungia herzi. These five fish species were selected as target species. HydroGeoSphere (HGS) and River2D models were used for hydrologic and hydraulic simulations, respectively. A habitat suitability index model was used to simulate fish habitat. To assess the impact of baseflow, each representative discharge was examined with or without baseflow. The HGS model was used to calculate baseflow within the study reach. This baseflow was observed to increase gradually with longitudinal distance. Validation of the hydraulic model dem onstrated that computed water surface elevated when baseflow was included, which was in good agreement with measured data, as opposed to the result when baseflow was excluded. Composite suitability index distributions and weighted usable area in the study reach were presented for target species. Simulations indicated that the baseflow significantly increased habitat suitability for the entire fish community. These results demonstrate that there should be a substantial focus on the baseflow for physical habitat simulation.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.455-466
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• 2013

The aim of this study is to seek application plans of National Ecosystem Survey database based on comparison and examination of feasible analysis methods for distribution characteristics of alien plants. In order to set up a correlation analysis method between alien plants and environmental factors, we had reviewed the 3rd National Ecosystem Survey guide book and consequently, two kinds of analysis method were tested. One was 1/25,000 scale map boundary based analysis and the other was representative mountain area based analysis. In this study we restricted the research area to select reliable surveyed database from whole "2011 National Ecosystem Survey flora database" according to two major criteria. First, an area defined by 1/25,000 scale map boundary and representative mountain area where the number of surveyed flora records should be within top 20%. Second, land cover map should also be built up inside that area. As a result, 25 map boundaries and 25 representative mountain areas were extracted to be analyzed. To limit a boundary for every representative mountain area we had analyzed distribution of environmental factors around that area by manual inspection with SPOT-5 remote sensed satellite image then designated 3km buffer zone from each alien plant location in that area. After then, naturalized index (NI) and urbanized index (UI) was calculated and correlations analysis was carried out. With the result of correlation analysis by map boundary only agricultural land area showed significant value of r (0.4~0.6, correlated) and the rest of factors did not. In the case of representative mountain area, the result showed that agricultural land, road and forest area showed significant value of r (0.6~0.8, highly correlated) which was corresponding to existing researches. Therefore, representative mountain area based method is preferable when using the alien plants database of National Ecosystem Survey for species distribution analysis. And also, considering the way of database utilization is strongly suggested at the first stage of survey planning for promoting active use of national ecosystem survey database.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.27-38
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• 2015

This study is for deriving an evaluation system which fits to the domestic urban river. For this, two times of Delphi survey was conducted to various experts who are eminent for ecology, urban design, governance, landscape architecture, hydrology. The purpose was for analysing validity and getting extra opinion of evaluation items which were preferentially have chosen. Reflecting $1^{st}$ survey's opinions as changing the word or explaining more details, the second survey was conducted, In this time, all evaluation items were analysed as valid and experts agreed with that. In conclusion, the evaluation items, "Amenity", "Biodiversity", "Ecosystem service", "Governance", "Management", which are for evaluating domestic urban river environment were derived.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.686-694
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• 2012

This study was conducted to investigate that affect benthic macroinvertebrates for installed erosion control works at a mountain torrential stream. The survey was carried out six times from April 2007 to October 2008 at two points where erosion control works were installed and at a control point in the upstream with no such works. Variations in the community structure and cluster of benthic macroinvertebrates and ecological water quality were analyzed in the survey. From the six times survey, the identified benthic macroinvertebrates were 6,922 individuals belonged to 27 species, 24 families, 13 orders, 6 classes and 4 phyla. As the average results of three surveyed sites, the dominant species was Gammarus sobaegensis of Amphipoda. The species diversity index(H') showed the highest as 1.47 at Site 2 of the fourth survey and the lowest as 0.24 at Site 2 of the sixth survey. The evenness Index(EI) showed the highest as 0.823 at Site 2 of the fourth survey and the lowest as 0.194 at Site 1 of the fifth survey. The richness index(RI) showed the highest as 2.794 at Site 1 of the first survey and the lowest as 0.291 at Site 2 of the sixth survey. The ecological score of benthic macroinvertebrate community(ESB) and individual of EPT-group were declined during the survey period. The functional feeding group(FFG) showed the highest SH types during the survey period.

• Journal of dental hygiene science
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• v.11 no.3
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• pp.229-234
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• 2011

This study obtained DMFT index(9271 people) in population with more than 6 years old based on data of 2009 Korea National Health and Nutrition Examination Survey, and calculated SiC index(2,517 people) by classifying group with high risk, which is 1/3 in high rank out of it. The aim was to confirm existence of the group with high risk of dental caries, and was to emphasize necessity of preventive strategy for the group with high risk. Statistical analysis was carried out t-test by using STATA 11.0 program. 1. DMFT index accounted for 45.0%(4,174 people) for men and 55.0%(5,097 people) for women. SiC index stood at 2,517 people. Men accounted for 36.3%(914 people). Thus, women were larger with 64.7%(1,603 people). 2. Seeing the mean in DMFT index and SiC index, the more rise in age led to the bigger difference in the mean between two groups. Especially, the difference was shown more than 4 points on the average for 13 and 14 years old and more than double on the average from over 15 years. 3. As a result of comparing gender, DMFT index was higher in women than men from over 14 years old. SiC index wasn't significant. However, women were indicated to be 1 piece more than men at the age of 9 and 14. 4. As a result of comparing by region, both DMFT index and SiC index were indicated to be higher in the rural area for their over 60s. Seeing the above results, the group with high risk is showing the higher rate of experiencing dental caries than DMFT-index in the whole. Thus, the comprehensively & intensively preventive management seems to be likely needed on group with high risk.

• Journal of the Korean Data and Information Science Society
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• v.19 no.1
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• pp.37-51
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• 2008

In this article, the aim is at evaluating the knowledge level of the foodbome disease by developing a reasonable survey questionnaire model. Each questions of the questionnaire is made up to check the knowledge covering the several fields of materials related to the foodbome disease. The pilot survey is implemented to evaluate the validity of questionnaire. Each question in questionnaire is scored to get the quantitative measure of the foodbome disease knowledge by converting the total score into 100 points.

• Journal of Distribution Science
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• v.11 no.1
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• pp.35-44
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• 2013

Purpose - This study aims to (a) analyze local citizens' perception of a local company, the Gwangyang Steel and Iron Company (GSIC); (b) compare the perception toward the local company with that of national citizens' perceptions towards many other unspecified companies, which were surveyed biannually by The Korea Chamber of Commerce and Industry (KCCI); and (c) analyze how such companies evaluate perceptions towards them, in relation to citizens' socioeconomic position, such as their education status. Research design, data, methodology - The data were collected using a questionnaire, which was given to a sample of local citizens in cities. To test the hypotheses, factor analyses, a t-test, and an ANOVA were conducted. The total number of respondents was 1798. The data gathered from the respondents of the sample were analyzed using SPSS Win 19.0 software. Perception towards the company was evaluated on the corporate favorite index (CFI). The CFI index shows how positive citizens feel towards a company. It is calculated using five leading factors, consisting of the following: contribution to the economy, productivity, international competitiveness, social contribution, and ethical management. The higher the level of positive feelings exhibited, the closer the index will come to 100. Results - As a result of the analysis, the CFI index towards the GSIC stood at 67.3. The CFI index towards the company is 16.5 points higher than that of the index towards the many other unspecified companies, which were surveyed by the bi-annual KCCI study in the first half of 2011. The other five indexes stood as follows: contribution to the economy, productivity, social contribution, and ethical management was 69.2, 71.2, 64.6, and 58.6, respectively. These indexes are 18.3, 4.6, 27.6, and 35.6, respectively, higher than those found by the KCCI study. However, international competitiveness is 73.0 (9.8 points lower than that of the KCCI study). This survey thus shows that the CFI of the local citizens towards the global company GSIC is very high when compared with the CFI index towards the many other unspecified companies that was determined by the KCCI survey. Conclusions - This survey shows that local citizens have high expectations of economic activity, increasing working opportunities, and regional cooperation projects from the local company, GSIC. In addition, the CFI index towards GSIC evaluates results depending on the respondent's relationship with the company, and their educational status. Respondents, whose family or relatives were working as employees of GSIC, have relatively positive perceptions of GSIC, and respondents with a relatively higher educational status also share positive perceptions. Local citizens expect the profit-making of the company to operate in accordance with management activities, and at the same time, they expect that the wealth generated by the company will return to wider society.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.647-648
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• 2010

• Fisheries and Aquatic Sciences
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• v.21 no.8
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• pp.24.1-24.9
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• 2018

The Korean bottom trawl survey has been deployed on a regular basis for about the last decade as part of groundfish stock assessments. The regularity indicates that they sample groundfish once per grid cell whose sides are half of one latitude and that of one longitude, respectively, and whose inside is furthermore divided into nine nested grids. Unless they have a special reason (e.g., running into a rocky bottom), their sample location is at the center grid of the nine nested grids. Given data collected by the survey, we intended to show how to appropriately estimate not only the survey index of a fish stock but also its uncertainty. For the regularity reason, we applied the systematic sampling theory for the above purposes and compared its results with a reference, which was based on the simple random sampling. When using the survey data about 11 fish stocks, collected by the spring and fall surveys in 2014, the survey indices of those stocks estimated under the systematic sampling were overall more precise than those under the simple random sampling. In estimates of the survey indices in number, the standard errors of those estimates under the systematic sampling were reduced from those under the simple random sampling by 0.23~27.44%, while in estimates of the survey indices in weight, they decreased by 0.04~31.97%. In bias of the estimates, the systematic sampling was the same as the simple random sampling. Our paper is first in formally showing how to apply the systematic sampling theory to the actual data collected by the Korean bottom trawl surveys.