• Korean Journal of Childcare and Education
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• v.1 no.1
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• pp.103-124
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• 2005

This study aims to investigate and analyze how toddlers' characteristics and child care center's environments including facilities and care-givers' characteristics affect toddlers' behavior in child care center using observational methods. Total 40 toddlers in same numbers of boys and girls participated in this study. Average age of tollers were the 31.7 months ranging from 27 months to 35 months. The toddlers were observed with the observation schedule modified from observation categories of Holloway and Reichhart-Erickson(1988). Data were analysed by Pearson's correlation, t-test, one away ANOVA, Duncan Test and stepwise regression using the SPSSWIN Version. The results of the study were as follow: First, the toddlers' behaviors were related to all the toddlers' characteristics. Second, the toddlers' behaviors were related to all the characteristics of the child care facilities such as the types of facilities, the class size and the caregiver-toddler ratio. Third, the toddler' behaviors were related to caregivers' variables such as the total care experience in centers, the experience with toddler care, the martial status, the certificate types except the child rearing experience and the educational level. Fourth, the toddlers' characteristics were more significantly related to the behavior of them than those of child care centers' environment.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.97-102
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• 2008

Purpose: Periodontal intrabony defects have great deal of importance since they contribute to the development of periodontal disease. Current treatment regimens for intrabony defects involve grafting of numerous bony materials, GTR using biocompatible barriers, and biomodification of root surface that will encourage the attachment of connective tissue. Xenograft using deproteinized bovine bone particles seems to be very convenient to adjust because it doesn't require any donor sites or imply the danger of cross infections. These particles are similar to human cancellous bone in structure and turned out to be effective in bone regeneration in vivo. We here represent the effectiveness of grafting deproteinized bovine bone particles in intrabony defect and furcation involvements that have various numbers of bony walls. Materials and methods: Open flap debridement was done to remove all root accretions and granulation tissue from the defects within persisting intrabony lesions demonstrating attachment loss of over 6mm even 3 months after nonsurgical periodontal therapy have been completed. Deproteinized bovine bone particles($BBP^{(R)}$, Oscotec, Seoul) was grafted in intrabony defects to encourage bone regeneration. Patients were instructed of mouthrinses with chlorohexidine-digluconate twice a day and to take antibiotics 2-3 times a day for 2 weeks. They were check-up regularly for oral hygiene performance and further development of disease. Probing depth, level of attachment and mobility were measured at baseline and 6 months after the surgery. The radiographic evidence of bone regenerations were also monitored at least for 6 months. Conclusion: In most cases, radio-opacities increased after 6 months. 2- and 3-wall defects showed greater improvements in pocket depth reduction when compared to 1-wall defects. Class I & II furcation involvements in mandibular molars demonstrated the similar results with acceptable pocket depth both horizontally and vertically comparable to other intrabony defects. Exact amount of bone gain could not be measured as the re-entry procedure has not been available. With in the limited data based on our clinical parameter to measure pocket depth reduction following $BBP^{(R)}$ grafts, it was comparable to the results observed following other regeneration techniques such as GTR.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.563-568
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• 2007

This paper presents a methodology for predicting nonlinear time series based on the neural network with weighted fuzzy membership functions (NEWFM). The degree of classification intensity is obtained by bounded sum of weighted fuzzy membership functions extracted by NEWFM, then weighted average defuzzification is used for predicting nonlinear time series. The experimental results demonstrate that NEWFM has the classification capability of 92.22% against the target class of GDP. The time series created by NEWFM model has a relatively close approximation to the GDP which is a typical business cycle indicator, and has been proved to be a useful indicator which has the turning point forecasting capability of average 12 months in the peak point and average 6 months in the trough point during 5th to 8th cyclical period. In addition, NEWFM measures the efficiency of the economic indexes by the feature selection and enables the users to forecast with reduced numbers of 7 among 10 leading indexes while improving the classification rate from 90% to 92.22%.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.2
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• pp.193-210
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• 2009

This research were to develop and apply an educational program for 6th grade students in mathematics by using level orientated teaching method and to make an analysis of their effects on students' mathematics learning achievements and mathematical disposition. Those purposes is following: First, we develop the level orientated teaching method that fits to the low level and high level students and analyze the effect on students' mathematics learning achievements. Second, we analyze the effect on students' mathematical disposition by using level orientated teaching method. The biggest problem of applying level orientated teaching method is that all the groups should do the meaningful activity while just one group is on process. So we tried to keep the proposition that level orientated teaching method should be helpful to both high and low level students. The duration of the research was about 8 weeks from march 2 to may 22 and the level orientated mathematics program consists in lesson 1 "a fraction and a decimal" to lesson 3 "The range of numbers". The results of this study are as follows : First, there was significant effect to the students, develop level orientated mathematics program and using that program. Second, there was an affirmative effect to the students about mathematical disposition using level orientated mathematics program. To sum up conclusion of this study, the level orientated mathematics program has an affirmative effect on mathematics learning achievements and mathematical disposition. We expect further research about level orientated teaching method and use effective level orientated teaching method widely.

• The KIPS Transactions:PartB
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• v.15B no.1
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• pp.25-36
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• 2008

In this paper, we present a robust hand recognition approach to sudden illumination changes. The proposed approach constructs a background model with respect to hue and hue gradient in HSI color space and extracts a foreground hand region from an input image using the background subtraction method. Eighteen features are defined for a hand pose and multi-class SVM(Support Vector Machine) approach is applied to learn and classify hand poses based on eighteen features. The proposed approach robustly extracts the contour of a hand with variations in illumination by applying the hue gradient into the background subtraction. A hand pose is defined by two Eigen values which are normalized by the size of OBB(Object-Oriented Bounding Box), and sixteen feature values which represent the number of hand contour points included in each subrange of OBB. We compared the RGB-based background subtraction, hue-based background subtraction and the proposed approach with sudden illumination changes and proved the robustness of the proposed approach. In the experiment, we built a hand pose training model from 2,700 sample hand images of six subjects which represent nine numerical numbers from one to nine. Our implementation result shows 92.6% of successful recognition rate for 1,620 hand images with various lighting condition using the training model.

• Journal of Preventive Medicine and Public Health
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• v.39 no.2
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• pp.115-122
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• 2006

Objectives : This study was conducted to examine the relationships of the several socioeconomic position indicators with the mortality risk in a representative longitudinal study of South Korea. Methods : The 1998 National Health and Nutrition Examination Survey was conducted on a cross-sectional probability sample of South Korean households, and it contained unique 13-digit personal identification numbers that were linked to the data on mortality from the National Statistical Office of Korea. Of 5,607 males and females, 264 died between 1999 and 2003. Cox's regression was used to estimate the relative risks (RR) and their 95% confidence intervals (CI) of mortality. Results: Socioeconomic differences in mortality were observed after adjustments were made for gender and age. Compared with those people having college or higher education, those people without any formal education had a greater mortality risk (RR=2.21, 95% CI=1.12-4.40). The mortality risk among manual workers was significantly greater than that for the non-manual workers (RR=2.73, 95% CI=1.47-5.06). A non-standard employment status was also associated with an increase in mortality: temporary or daily workers had a greater mortality risk than did the full-time workers (RR=3.01, 95% CI=1.50-6.03). The mortality risk for the low occupational class was 3.06 times greater than that of the high and middle occupational classes (95% CI=1.75-5.36). In addition, graded mortality differences according to equivalized monthly household income were found. A reduction of monthly household income by 500 thousand Korean Won (about 400 US dollars) was related with a 20% excess risk of mortality. Self-reported poor living standards were also associated with an increased risk of mortality. Those without health insurance had a 3.63 times greater risk of mortality than the insured (95% CI=1.61-8.19). Conclusions: This study showed the socioeconomic differentials in mortality in a national longitudinal study of South Korea. The existence of socioeconomic mortality inequalities requires increased social discussion on social policies in Korean society. Furthermore, the mechanisms for the socioeconomic inequalities of mortality need to be explored in future studies.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.263-268
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• 2021

The purpose of this study was to propose a model which is suitable for the actual delivery system by designing a fetal delivery hospital operation management and fetal health classification model. The number of deaths during childbirth is similar to the number of maternal mortality rate of 295,000 as of 2017. Among those numbers, 94% of deaths are preventable in most cases. Therefore, in this paper, we proposed a model that predicts the health condition of the fetus using data like heart rate of fetuses, fetal movements, uterine contractions, etc. that are extracted from the Cardiotocograms(CTG) test using a random forest. If the redundancy of the data is unbalanced, This proposed model guarantees a stable management of the fetal delivery health management system. To secure the accuracy of the fetal delivery health management system, we remove the outlier which embedded in the system, by setting thresholds for the upper and lower standard deviations. In addition, as the proportion of the sequence class uses the health status of fetus, a small number of classes were replicated by data-resampling to balance the classes. We had the 4~5% improvement and as the result we reached the accuracy of 97.75%. It is expected that the developed model will contribute to prevent death and effective fetal health management, also disease prevention by predicting and managing the fetus'deaths and diseases accurately in advance.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.86-107
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• 2014

The large stone cist tomb 8501 of Lingcheng prefecture Xiaoheishigou, according to Chinese chronology, was built during the late Western Zhou period. However in this tomb not only Chinese Zhongyuan style bronze ceremonial vessels but also indigenous style bronze ceremonial vessels and instruments and hybrid bronze ceremonial vessels with a mixture of both indigenous and Chinese styles were excavated in large numbers. The bronze ceremonial vessel assemblage of Xiaoheishigou, in comparison with the decorum regulations and bronze cauldron and coffer system of the Chinese Zhongyuan region of the same time period, belong to that of the lowest status category. However, in contrast to the lowest class category tombs of the Chinese Zhongyuan region, in this tomb, with the exception of cauldrons and coffers, the remaining food and wine vessels of the assemblage match the standard of emperors and feudal rulers of vassal states. This is reinforced by the burial of musical instruments. Of the bronze ceremonial vessels of Xiaoheishigou large stone cist tomb 8501, the indigenous and hybrid styles, in consideration of manufacture technology seem to have been manufactured locally. However, the form, pattern and also the standards of the Western Zhou style bronze ceremonial vessels are identical to those of the Chinese Zhongyuan region and therefore it is clear that they were manufactured in Western Zhou. The reason for these precious ceremonial vessels which were manufactured and used in the many individual vassal states of the Chinese Zhongyuan region being buried in Xiaoheishigou, seems to have been the result of economic exchange and friendly political relations between the Xiaoheishigou and other groups rather than these vessels having been plundered by the Xiaoheishigou group. A distinct cultural sphere existed between the Upper Xiajiadian culture and Western Zhou which interacted frequently with both sides.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.203-217
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• 2021

Background: Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results: A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions: Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.121-145
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• 2010

University timetabling depending on the educational environments of universities is an NP-hard problem that the amount of computation required to find solutions increases exponentially with the problem size. For many years, there have been lots of studies on university timetabling from the necessity of automatic timetable generation for students' convenience and effective lesson, and for the effective allocation of subjects, lecturers, and classrooms. Timetables are classified into a course timetable and an examination timetable. This study focuses on the former. In general, a course timetable for liberal arts is scheduled by the office of academic affairs and a course timetable for major subjects is scheduled by each department of a university. We found several problems from the analysis of current course timetabling in departments. First, it is time-consuming and inefficient for each department to do the routine and repetitive timetabling work manually. Second, many classes are concentrated into several time slots in a timetable. This tendency decreases the effectiveness of students' classes. Third, several major subjects might overlap some required subjects in liberal arts at the same time slots in the timetable. In this case, it is required that students should choose only one from the overlapped subjects. Fourth, many subjects are lectured by same lecturers every year and most of lecturers prefer the same time slots for the subjects compared with last year. This means that it will be helpful if departments reuse the previous timetables. To solve such problems and support the effective course timetabling in each department, this study proposes a university timetabling support system based on two phases. In the first phase, each department generates a timetable template from the most similar timetable case, which is based on case-based reasoning. In the second phase, the department schedules a timetable with the help of interactive user interface under the timetabling criteria, which is based on rule-based approach. This study provides the illustrations of Hanshin University. We classified timetabling criteria into intrinsic and extrinsic criteria. In intrinsic criteria, there are three criteria related to lecturer, class, and classroom which are all hard constraints. In extrinsic criteria, there are four criteria related to 'the numbers of lesson hours' by the lecturer, 'prohibition of lecture allocation to specific day-hours' for committee members, 'the number of subjects in the same day-hour,' and 'the use of common classrooms.' In 'the numbers of lesson hours' by the lecturer, there are three kinds of criteria : 'minimum number of lesson hours per week,' 'maximum number of lesson hours per week,' 'maximum number of lesson hours per day.' Extrinsic criteria are also all hard constraints except for 'minimum number of lesson hours per week' considered as a soft constraint. In addition, we proposed two indices for measuring similarities between subjects of current semester and subjects of the previous timetables, and for evaluating distribution degrees of a scheduled timetable. Similarity is measured by comparison of two attributes-subject name and its lecturer-between current semester and a previous semester. The index of distribution degree, based on information entropy, indicates a distribution of subjects in the timetable. To show this study's viability, we implemented a prototype system and performed experiments with the real data of Hanshin University. Average similarity from the most similar cases of all departments was estimated as 41.72%. It means that a timetable template generated from the most similar case will be helpful. Through sensitivity analysis, the result shows that distribution degree will increase if we set 'the number of subjects in the same day-hour' to more than 90%.