• KIPS Transactions on Software and Data Engineering
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• v.2 no.12
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• pp.855-864
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• 2013

Decision tree classification is one of the important problems in data mining fields and data minings have been important tasks in the fields of large database technologies. Therefore the coupling efforts of data mining systems and database systems have led the developments of database primitives supporting data mining functions such as decision tree classification. These primitives consist of the special database operations which support the SQL implementation of decision tree classification algorithms. These primitives have become the consisting modules of database systems for the implementations of the specific algorithms. There are two aspects in the developments of database primitives which support the data mining functions. The first is the identification of database common primitives which support data mining functions by analysis. The other is the provision of the extended mechanism for the implementations of these primitives as an interface of database systems. In data mining, some primitives want be stored in DBMS is one of the difficult problems. In this paper, to solve of the problem, we describe the database primitives which construct and apply the optimized decision tree classifiers. Then we identify the useful operations for various classification algorithms and discuss the implementations of these primitives on the commercial DBMS. We implement these primitives on the commercial DBMS and present experimental results demonstrating the performance comparisons.

• Journal of Korea Technology Innovation Society
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• v.16 no.4
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• pp.1163-1186
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• 2013

Big science such as nuclear fusion accelerators shares the characteristic of requiring long-term and massive budget input, human power, and related state-of-the-art technology. Because big science, by nature, thus requires large-scale budgets and facilities yet harbors the possibility of failure, most projects are led by the government. When the actual circumstances are examined, however, such projects are often implemented through the formation of cooperative relations with small and medium businesses (SMBs) possessing outstanding technological capacity. On the other hand, the reality is that the entry of corporations into the business ecosystem of big science is not easy and that even those that have once entered big science likewise fail to find sales outlets for technology that they have developed following the supply of single items, thus leading their technological capacity to lie idle. Consequently, based on an awareness of the problem, the present study seeks to propose strategies for activating the business ecosystem of nuclear fusion and accelerators and to present alternatives regarding which policy tasks must be pursued first by using the analytic hierarchy process (AHP) technique. The present study derived the four policy alternatives of approach, care, expansion, and infrastructures in accordance with the results of empirical analysis to activate the business ecosystem of nuclear fusion and accelerators and analyzed their priority in terms of urgency and effectiveness, the results of which were, in this order: care-approach-expansion-infrastructures. The significance of such research results lie in presenting the policy direction when the government determines which policy task must be pursued first and implements strategies for the activation of the business ecosystem of nuclear fusion and accelerators with limited financial resources in the future.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.43-52
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• 2013

A roundabout is a form of circular intersection in which traffic travels counterclockwise around a central island and in which entering traffic must yield to circulating traffic. It has been known that a roundabout provides substantially better operational and safety characteristics than other intersections including rotaries. Recently, a roundabout has started to be constructed due to its efficiency, safety, and other advantages of a roundabout comparing other intersections in Korea. However, there has been no guideline to be used to decide appropriate intersection types considering given conditions of the intersections. To solve this problem, the guideline with traffic volume to choose the suitable intersection types was developed based on analysis results using the SIDRA software which is generally used to analyze operational effects of roundabouts. It was found that a roundabout is more efficient than signalized intersection when the traffic volume is between 125 and 450 veh/h on one lane road and roundabout is not recommended when there are more than 30% left turn traffic. The optimal traffic volume provided in this research will be usefully used in planing and designing roundabouts in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.1-8
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• 1985

Stability analysis of the embankment as to water level varation is the most important problem in the safety of the slope because the stress of embankment inside varies as to drawdown of seepage line. Especially when the water level is rapidly drawdown, because the flow direction of the free surface changes the toe of embankment, the factor of safety comes to small, therefore the embankment is dangered. For the purpose of studing these phenomena, the experimental models are built with sand in the laboratory. In the experimental consideration, the falling seepage line and the shape of failure are measured. This paper intends to study the failure slip surface, the relationship between the factor of safety and drawdown velocity, and hydraulic gradient. The results of the experimental study are summarized as follows; 1. Owing to the drawdown of free surface, sliding failure occurred in the upstream fill, the height of failure is 5~10, 9~15, and 13~21(cm) in each model. 2. In consideration of the distribution of pore water pressure Table-5 shows each factor of safety. In the relationship between the drawdown velocity and the factor of factor it's velocity should be limited to 0.21~0.28 (cm/sec), according to each models. In the relationship between the factor of safety and the hydraulic gradient within the upstream slope, it's gradient must be below 0.36~0.43.

• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.205-223
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• 2016

Objective:This study introduced the status of studies and the projects related with agricultural accident prevention carried out by the Rural Development Administration. This study was conducted to promote Korean farmers' agricultural safety activation by analyzing study trends on farmers' agricultural work safety. Background: Agriculture is one of the dangerous industries, and the agricultural accident rate is on the rise, due to recent serious aging and increased female work force. Such a phenomenon emerges as a serious problem from the social perspective, and therefore measures for farmers' healthy and safe agricultural activities and accident prevention are required. Method: This study conducted literature review related with domestic and international agricultural safety and health. This study also examined the hazard factors of agricultural labor and injuries, agricultural safety and health system and policy, support and education for farmers' safety practice, and the status of convenience tools and protection equipment, based on major study activities performed by the Rural Development Administration for recent four to five years. Results: Through the study results, the status of Korea's agricultural safety system, compensation support policy, safety education of farmers for actual practice, and diverse channels including media were confirmed. This study also presented the R&D implementation status on convenience equipment and protective gear to prevent agricultural diseases and safety accidents. Conclusion: This study found out that continuous monitoring and efforts are required to prevent accidents for the Korea's agricultural labor environment and agricultural safety, and that social bond of sympathy formation is demanded through effect analysis on the implemented projects including education and support projects. Furthermore, it can be understood that agricultural accident prevention should be carried out through shift from current government-led top down approach to bottom-up approach from itself. Application: The results of this study can be utilized as useful data for farmers' safety and health.

• Korean Journal of Child Education & Care
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• v.18 no.3
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• pp.159-178
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• 2018

Objective: The purpose of this study was to understand the characteristics of dietary education in South Korea and Japan, and find directions for dietary education by comparing the contents of the two countries' dietary education in their national child-care curriculums and evaluations. Methods: To this end, a qualitative content analysis was conducted on the guidebooks for the Standard Child-care Curriculum and the Accreditation Index for Child-care Center in the case of South Korea, and the handbook for the Child-care Guideline and the Third Party Evaluation in the case of Japan. Results: The findings of this study were as follows: First, South Korea showed differences in the focus of child-care curriculums and evaluations. The contents about proper eating such as nutrition and table manners comprised a high portion of the curriculums, whereas the contents about cleanness and hygiene accounted for a high portion of the evaluations. In the case of Japan, its national child-care curriculums and evaluations consistently emphasized contents related to enjoying eating oneself, and suggested various methods for this. Second, in terms of the two countries' approaches to dietary education, South Korea focused on food-related knowledge, whereas Japan mainly created the contents of dietary education based on daily experiences. Conclusion/Implications: The above results suggest a direction to improve the currently publicized dietary guidance problem and a need for consistent the national child care curriculum and evaluation indicators in South Korea to emphasize the importance of joyful eating.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.266-274
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• 2020

This paper reports a means of improving the abnormal noise of light tactical vehicles (LTVs) by applying a vehicle fitting type generator (hereinafter called generator). LTVs are classified as having generators, and there are no differences in the noise level. On the other hand, quality improvement was performed in response to unpleasant noise felt by the user (hereinafter called abnormal noise) during vehicle operation. To improve the quality, the generator mounting structure and the phenomenon of the vehicle in the problem were identified. Through this, it was confirmed that the noise caused by the generator installation was the rattle noise. Rattle noise at the engine driving system is normally caused by the transfer of irregular torque generated by the engine power stroke and the backlash by the spline-serration fitting structure between the engine coupler and rotor assembly in a generator. Therefore, this study established an improvement plan to apply a damper coupler to solve the cause of the abnormal noise. Regarding the improved establishment method, the improvement effect was confirmed from the influence of the irregular torque of the engine, noise level, dynamic characteristics analysis, and the endurance test of the parts.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.11
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• pp.265-272
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• 2020

In the research of brain computer interface (BCI) technology, one of the big problems encountered is how to deal with some people as called the BCI-illiteracy group who could not control the BCI system. To approach this problem efficiently, we investigated a kind of spectral EEG characteristics in the prior resting state in association with BCI performance in the following BCI tasks. First, spectral powers of EEG signals in the resting state with both eyes-open and eyes-closed conditions were respectively extracted. Second, a convolution neural network (CNN) based binary classifier discriminated the binary motor imagery intention in the BCI task. Both the linear correlation and binary prediction methods confirmed that the spectral EEG characteristics in the prior resting state were highly related to the BCI performance in the following BCI task. Linear regression analysis demonstrated that the relative ratio of the 13 Hz below and above the spectral power in the resting state with only eyes-open, not eyes-closed condition, were significantly correlated with the quantified metrics of the BCI performance (r=0.544). A binary classifier based on the linear regression with L1 regularization method was able to discriminate the high-performance group and low-performance group in the following BCI task by using the spectral-based EEG features in the precedent resting state (AUC=0.817). These results strongly support that the spectral EEG characteristics in the frontal regions during the resting state with eyes-open condition should be used as a good predictor of the following BCI task performance.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.14 no.4
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• pp.437-445
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• 2007

Purpose: The purpose of this study was to identify levels of knowledge, perception, and practice of eye care as part of nursing care in the ICU. Method: A descriptive, cross-sectional study design was used. The participants in this study were 269 registered nurses working in the ICUs of five university hospitals in Seoul, Korea. Between November 2005 and December 2005, data were collected using a semi-structured questionnaire developed by the researchers, and analyzed using the SPSS Program. Results: In general, levels of knowledge of nursing care for the eyes were moderate among ICU nurses, but levels of perception of nursing care for the eyes were very high. Of the respondents, 61.7% reported that they would consult a doctor whenever they found an eye problem. Only 42.4% nurses answered that they provide eye care as part of the daily routine and 43.9% nurses responded that they cleanse the eye lids with wet saline gauze. In regression analysis, the practice of eye care as part of nursing was significantly influenced by perception of nursing care for the eyes, and knowledge of interventions for nursing care for the eyes. Conclusion: These results suggest that education on care of the eyes for ICU nurses and the development of a standardized eye care protocol should be done to improve quality of nursing care in the ICU.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.1-16
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• 2016

After entering a more stable growth phase since the 2000s, new urban development has become smaller and fragmented and interiors of existing cities are aging and becoming underutilized. Therefore, using vacant and underutilized land in urban area has high value in national urban policies in terms of compact urban development and circular land use management. To do so, it is necessary to develop scientific research methods and tools to better understand the characteristics and potential of vacant and underutilized land. The main goals of the study are as follows. First, this research aims to develop a pilot system for analysis and assessment of abandoned, vacant, and underutilized space. The pilot system will act as a scientific policy support measure to systematically identify vacant and underutilized space. Busan Metropolitan City, with a variety of vacant and underutilized space, was selected as the case study area. The second goal is to develop a planning support system for abandoned, vacant and underutilized Land using open source GIS software, uDig. GIS based decision support systems or planning support systems to resolve spatial problem is not a new innovation, but using open source GIS provides new opportunities and potential. To conclude, the research will derive implications for future work.