• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.28 no.5
• /
• pp.503-516
• /
• 1995

Macrobenthic community was studied in Deukryang Bay, southwestern coast of Korea, in November 1991 and Januavy 1992. Hacrobenthic fauna consisted of 118 species with 20,767 individuals. The number of species and occurrence frequency of the major groups were as follows: 52 polychaetes species $(44.1\%)$, 45 crustaceans species $(38,1\%)$, 14 mollusks species $(11.9\%)$ and 7 other group species $(5.9\%)$. The mean density was $1432.2ind/m^2$. The density of major groups showed that mollusks was 920.4$(ind./m^2)$, polyrhaetes 275.8$(ind./m^2)$, and crustaceans 219.6$(ind./m^2)$. The dominant species were Musculista senhousia (Bivalvia), Eteone longa (Polychaeta), Nippopisella nagatai (Amphipoda) with density, 632.8$ind./m^2$, 37.8$ind./m^2$, and 35.3$ind./m^2$, respectively. This area could be divided into four areas by the cluster analysis based on the species composition.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.1
• /
• pp.126-137
• /
• 2021

Recently, the number of damages on social infrastructure has increased due to natural disasters and the frequency of earthquake events that are higher than magnitude 3 has increased in South Korea. Liquefaction was found near the epicenter of a 5.4 magnitude earthquake that occurred in Pohang, South Korea, in 2017. To explore increases in soil moisture index due to soil liquefaction, changes in the remote exploration index by the land cover before and post-earthquake occurrence were analyzed using liquefaction feasibility index and multi-cyclical Landsat-8 satellite images. We found that the soil moisture index(SMI) in the liquefaction region immediately after the earthquake event increased significantly using the Normal Vegetation Index(NDVI) and Surface Temperature(LST).

• Journal of the Korean Society for information Management
• /
• v.40 no.1
• /
• pp.121-148
• /
• 2023

The purpose of this study is to propose a scholarly paper recommendation system based on metadata attribute similarity with excellent performance. This study suggests a scholarly paper recommendation method that combines techniques from two sub-fields of Library and Information Science, namely metadata use in Information Organization and co-citation analysis, author bibliographic coupling, co-occurrence frequency, and cosine similarity in Bibliometrics. To conduct experiments, a total of 9,643 paper metadata related to "inequality" and "divide" were collected and refined to derive relative coordinate values between author, keyword, and title attributes using cosine similarity. The study then conducted experiments to select weight conditions and dimension numbers that resulted in a good performance. The results were presented and evaluated by users, and based on this, the study conducted discussions centered on the research questions through reference node and recommendation combination characteristic analysis, conjoint analysis, and results from comparative analysis. Overall, the study showed that the performance was excellent when author-related attributes were used alone or in combination with title-related attributes. If the technique proposed in this study is utilized and a wide range of samples are secured, it could help improve the performance of recommendation techniques not only in the field of literature recommendation in information services but also in various other fields in society.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.1
• /
• pp.65-74
• /
• 2005

National groundwater monitoring stations have been managed throughout the country by Korea Water Resources Corporation (KOWACO) in order to monitor variations in quantity and quality of groundwater resources. A multi-sensor installed in each monitoring station well measures groundwater level, water temperature and electrical conductivity every six hours and the logged data are automatically transmitted to a host computer in KOWACO. Meanwhile despite regular station inspection and replacement of deteriorate or broken devices, abnormal values or outliers often occur due to intrinsic limitations of automatic monitoring and transmission. Thus prompt recognition and measures to these values are essentially required to reduce disturbance and missing period of the data. In this study, time and frequency of outlier occurrence were analyzed for the water level data obtained from national groundwater monitoring stations within the Han river basin in 2000. The analysis results indicated that the most prominent patterns of the outliers were rapid decline for water level, no variation for temperature and steep decline for electrical conductivity. This study provided a sample criterion for determining the outlier for each parameter.

• Journal of Navigation and Port Research
• /
• v.32 no.8
• /
• pp.569-576
• /
• 2008

By the development of international trade in last decades, Korean International Trade has been grown rapidly and Korean Port and Port facilities have been improved stimultaneously: finally volume of the marine traffic increased rapidly. Presently, 15 VTS centers have serving in Korean waters and since the introduction of the first VIS Center in Korea there is no quantitative analysis to find workload of VIS operator. After that Port-MIS and De-brief data have been gathered for 7 days and inbound-outbound vessels time-g/t table prepared and traffic volume examined for each V1S center. Hence $L^2$ conversion traffic volume and dangerous vessel ratio obtained Later on conversion controlled number obtained by denoting ratio 1.0 to directly controlled vessels by VTSO and denoting ratio 0.3 to indirectly controlled vessels by VTSO. Traffic volume, large vessel ratio, dangerous vessel ratio, dimension of VTS controlled area, marine accident occurrence frequency and communication volume of comm. log can be counted as a factor which influence to workload of VTSO. All those factors have been examined and analyzed. Finally, ship's size and dangerous vessel ratio have been chosen to derive the Number of composite conversion control for workload formula.

• Korean Journal of Weed Science
• /
• v.1 no.1
• /
• pp.78-83
• /
• 1981

This study was attempted to determine the major weed species occurring in Korean turfgrass, Zoysia japonica Steud. and to evaluate the most effective means for controlling them. More or less 40 weed species were determined to occur in Korean turfgrass. In terms of quantity and frequency of occurrence, Trifolium repens L., Digitaria sanguinalis (L.) Scop., Draba nemorosa var. hebecarpa Lindbl, Erigeron canadensis L., and Cyperus amuricus Max were observed to be the major weeds. Simpson's index, 0.306 was obtained to be the major weeds. Simpson's index, 0.306 was obtained in the golf course, Jinryang, Gyungsan-gun, meaning that no specific weed species were dominant, but in Kyungpook National University campus, Trifolium repense L. was a single dominant species, indicating Simpson's index, 0.776. The most effective herbicides to control Trifolium repense L. and other broad leaf weeds were MCPP [2-(2-methyl-4-chlorophenoxy) propionic acid), followed by 2,4-D (2,4-dichlolophenoxy acetic acid). Increased rates of both herbicides increased markedly their effectivity against weeds, with very slight injury against turfgrass. MCPP at 2.8 kg(a.i.)/ha gave excellent control without any injury and 2,4-D at 1.0 kg(a.i.)/ha.

• The Journal of Korean Academy of Prosthodontics
• /
• v.50 no.4
• /
• pp.258-270
• /
• 2012

Purpose: Use of inappropriate statistical methods may lead to incorrect conclusions and a waste of valuable resources. The goal of this study was to assess the frequency and the types of several common statistical errors in the published articles of the Journal of the Korean Academy of Prosthodontics (JKAP) for a 5-year period. Materials and methods: Of 336 articles in the JKAP published from 2006 to 2010, 255 articles using statistics were reviewed and classified by statistical method and year. The frequency and types of the statistical methods were examined, and the statistical errors were evaluated by the appropriateness of the experimental design, assumption check, independent outcomes, proper sample size and suitable use of statistical method. Statistical guidelines were completed based on the appropriateness. Results: Of the 255 articles using statistics, 193 articles (75.9%) used inferential statistics and 153 articles used SPSS statistical software (60.0%). Of the articles using inferential statistics, the three most frequently used statistical methods were ANOVA (41.5%), t-test (20.0%), and the nonparametric method (16.9%). The average rate of statistical errors was 61.2 percent, similar to the rate reported by several studies completed for the medical journal. Conclusion: After the whole analysis of the difference among the groups, post-hoc tests for the pairwise comparisons are required. The optimal sample size calculation is an essential part of this study protocol. To minimize the occurrence of statistical errors, statistical guidelines were developed according to each statistical test procedure and will contribute to the academic improvement in the JKAP.

• Korean Journal of Psychosomatic Medicine
• /
• v.29 no.1
• /
• pp.34-41
• /
• 2021

Objectives : The purpose of this study is to investigate the characteristics of depressive patients who admitted to general hospital. We examined the clinical characteristics of patients who were referred to the Department of Psychiatry as depressive symptoms, according to the type of consultation request, and comparing 'with re-consultation' and 'without re-consultation' groups. Methods : We performed a retrospective chart review of 4,966 inpatients who were referred to the Department of Psychiatry from August 2005 to December 2011. Results : For about 6 years, among the inpatients referred for psychiatric consultation, a total of 647 patients were referred for depressive symptoms, accounting for 13.82% of the total consultations. The average age of depressive patients was 58.6 years, which was higher than the average of 56.4 years of overall patients. Among the depressive patients, 275 patients were included in 'with re-consultation' group and there was no statistically significant difference when comparing 'with re-consultation' group and 'without re-consultation' group. However, there was a difference in the tendency of the two groups in the type of consultation request. 'With re-consultation' group was in the order of frequency of consultation type 3-2-1, whereas the 'without re-consultation' group was in the order of frequency of consultation type 2-3-1. Conclusions : The group of inpatients who were referred for depressive symptoms in general hospital showed the largest proportion of the group of patients referred to the Department of Psychiatry. 'With re-consultation' group had a higher rate of re-consultation due to the occurrence of new symptoms after hospitalization compared to 'without re-consultation' group. Therefore, doctors in each department and psychiatrists should pay attention to the depressive symptoms of inpatients and actively discuss treatment plans to improve the quality of medical services, identify risk factors, and make efforts to intervene early if necessary.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.15 no.3
• /
• pp.33-50
• /
• 1988

This study was executed to find out how to improve on the planting and use of the plants in Kangweon- Do by surveying the planting areas -gardens, parks, streets, schools, etc. - in five cities of this province, and to select available native plants by surveying the main mountains in this province. The results are as follows ; 1. The species number within surrey areas was 319 species. and the species of which planting frequency was very high were Hibiscus syriacus, Juniperus chinensis, Buxus microphylla v. koreana, etc.. 2. The species number of school trees and flowers of 202 schools in Kangweon-Do were 33 species, 32 species respectively. and the species of school trees and flowers that showed the highest preference were Juniperus chinensis, Forsythia koreana each. 3. The species number of flowers and trees designated in 22 City and Keun were 14 species, 7 species respectively, and the species of flowers and trees that presented the highest designation frequency were Rhododendron schlippenbachii, Ginkgo biloba each. 4. The street trees planted along the main streets in Kangweon-Do were 18 species and 84,939 individuals, and the ratio of Populus alba${\times}$glandulosa was the highest among occurrence individuals. 5, As for the composition ratios of life forms of plants within survey areas, the ratio of deciduous broad-leaved tree was the highest as about 56% and that of deciduous coniferous tree was the lowest as about 1.6%. The ratios of native species versus exotic were 43 : 57 6. Through these results, it was thought that the diversification of planing species, the selection of plants suitable to each space and the generalization of use of native species were needed. So 254 plants native to Kangweon-Do were presented to correspond to these requirements.

• Journal of Korean society of Dental Hygiene
• /
• v.12 no.3
• /
• pp.453-463
• /
• 2012

Objectives : The oral health education for interaction between snack and oral health is made more in detail, it seems to contribute to improvement of oral health by reducing occurrence of dental caries. Methods : This study performed the survey for 530 high school and college students living in Y City, Chungbuk for 10 days from June 14, 2011 to understand the difference by the level of snack recognition. 530 copies of questionnaire were collected, the final 502 copies were analyzed and the results are as followings. Results : 1. As for the snack intake frequency, 'sometimes' and '2~3 times a day' was found to be largest with 32.0% respectively in female and 'sometimes' was largest with 34.9% in male. As for the '2~3 times a day' was most in high school students with 31.5% and 'sometimes' was most in college students with 39.0%. 2. As for snack characteristics, 'crispy' was most preferred in female and male with 43.7% and 39.4% respectively and, by school year, high school students and college students preferred 'crispy' most with 39.1% and 46.0% respectively. 3. As for the item of meal, 'sometimes skip' was most in female with 46.1% and 'all three meals a day' was most im male with 51.4%. 'All three meals a day' was proved to be most with 48.3%in high school students and 'sometime skip' was most in college students with 48.0%. 4. As for the difference of oral health management by school year, college students ($3.37{\pm}0.70$) proved to be higher in the oral health management (p<.01) than high school students ($2.98{\pm}0.81$) and the Negative snack recognition group ($3.24{\pm}0.73$) was found to be higher in the oral health management (p<.01) than the Positive snack recognition group ($3.06{\pm}0.82$). Although the interaction between school year and snack recognition level was not different in case of college students, the Negative snack recognition($3.17{\pm}0.77$) proved to manage higher oral health (p<.05) than the high snack recognition gathering ($2.81{\pm}0.80$) in case of high school students. 5. As for the difference of the oral health most im male wex and). Although the innteractifemale ($3.39{\pm}0.72$) proved to most the oral health (2.(p<.01) than male ($2.81{\pm}0.75$) and the group with Negative snack recognition terac ($3.24{\pm}0.73$) most d the oral health (2.(p<.01) than the group with Positive snack recognition level ($3.06{\pm}0.82$). As for effects of interaction between sex and snack recognition level, while there was not much difference in the oral health management by the snack recognition level in case of female, the cluster of low snack recognition level ($3.03{\pm}0.69$) proved to manage the oral health more (p<.01) than the gathering of high snack recognition level ($2.59{\pm}0.75$). Conclusions : To see the results as above, it can be seen the oral health management is higher as the snack recognition level is higher by sex and school year.