• Journal of Korean Clinical Nursing Research
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• v.25 no.1
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• pp.25-33
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• 2019

Purpose: This study was done to develop a program to promote maternal role confidence and maternal attachment for mothers of premature infants and to evaluate the effects in a neonatal intensive care unit (NICU). Methods: This program was developed through a literature review and validation of an expert group, and tested with 60 preterm infants (experimental group 30, control group 30) in a NICU in South Korea. Data were collected from December 2017 to March 2018 and analyzed using descriptive statistics, t-test, $x^2-test$ and Fisher's exact test with the SPSS/Win statistical program. Results: Maternal role confidence for the experimental group increased significantly compared to the control group (t=3.22, p=.002). Maternal attachment in the experimental group increased significantly compared to the control group (t=2.30, p=.025). Conclusion: The program developed in this study should be effective in promoting maternal role confidence and maternal attachment in mothers of premature infants.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1218-1221
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• 1993

The elevator group control systems are the control systems that manage systematically three or more elevators in order to efficiently transport the passingers. In the elevator group control system, the area-weight which determines the load biases of elevators is a control parameter closely related to the system performance. This paper proposes a fuzzy model based method to determine the are-weight. The proposed method uses a two-stage fuzzy inference model which is built by the study of area-weight properties and expert knowledge. The proposed method shows the more desirable results than the conventional method in the simulations that use real traffic data.

• The Korean Journal of Health Service Management
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• v.13 no.2
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• pp.67-79
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• 2019

Objectives: The purpose of this study was to analyze the factors affecting the utilization of emergency medical services and characteristics of emergency medical services according to age group among elderly individuals. Methods: This study conducted t-test and linear regression analysis on data of 1,960,575 participants to achieve the objective. Results: Analysis of the factors affecting the use of emergency medical services showed statistically significant correlation in all age groups. As the age of elderly people increased, the use of emergency medical service increased. Conclusions: Emergency medical policies are needed, such as coordinators with expert knowledge of medical and health administration and specialist emergency room operations that can provide specialized medical service for older patients.

• Journal of the Korean Geotechnical Society
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• v.30 no.1
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• pp.75-91
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• 2014

In this study the analysis is performed for influencing factors on the behavior of rigid piles (short pile) by research papers and case study. The results indicated that the point of virtual fixity should be calculated considering the relative stiffness of soil and pile, and Chang (1937) and P-Y method estimated the similar fixity. The values of ultimate resistances of a vertical pile to a lateral load are different for laboratory and field tests in cohesive soils and its ultimate values in laboratory tests are underestimated and in field tests are under or overestimated. The estimated resistance by Hansen (1961)'s method is similar to the value of field tests. The horizontal resistances to laterally loaded pile in cohesionless soils are overestimated in laboratory tests and generally overestimated in field tests. The ultimate resistances by Zhang (2005)'s method, used to the empirical distribution of the resistance, are similar to the test results. In the paper the calculating method and distribution of the ultimate resistance in cohesive soils are proposed. The estimated value by the proposed method is closer to the test results than any other method of calculating ultimate resistance of the piles embedded into cohesive soils.

• Journal of the Korean association of regional geographers
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• v.17 no.1
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• pp.58-74
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• 2011

This study analyzed and compared the importance and priority of location decision factors in Foreign Direct Investment Firms managing the manufacturing business in the nation's southeastern economic zone, and in expert group by using AHP analytical technique based on examining the location theory and the prior research of real estate for industry. Also, it analyzed difference in importance and priority for location factors by corporate scale, by business category, and by location type targeting only foreign direct investment firms, and offered references necessary for location decision-making. In addition, to elicit useful information for policy related to location decision factors for foreign direct investment firms, the implications were elicited by analyzing the results recognized between foreign direct investment firms and expert group on information elements regarding investment satisfaction, business bottlenecks, and location decision process. The considerable gap was indicated in importance and priority of location decision factors considered between the nation's foreign direct investment firms and real-estate expert group for industry. As a result of analyzing by reflecting the corporate characteristic variable in location assessment model unlike before, the importance of the competitive advantage factor and the business strategic factor was indicated to be very high.

• Journal of the Korean Geotechnical Society
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• v.30 no.4
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• pp.47-63
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• 2014

In this study theories of earth pressure such as Rankine, Coulomb, Trial Wedge, Improved Trial Wedge, used in the design for onshore and offshore structures, are analyzed and the characteristics of loaded pressure to virtual back (wall, plane) and wall surface in accordance with the structure type are suggested. To investigate characteristics of earth pressure, gravity retaining wall with inclined angle and cantilever wall with inclined ground are movilized for onshore structures and caisson and block type quay wall are mobilized for offshore structures. Based on various theories, the earth pressure applied angle(wall friction angle) and sliding angle toward the wall, which is influenced by the heel length, are calculated and compared. In the case of long heel, the pressure by Rankine's method in virtual plane and the mobilized angle are most reasonably estimated by the ground slope, and in the case of short heel, the pressure by Coulomb's method and the mobilized angle by the angle of wall friction. In addition, the sliding angle toward the wall estimated by the improved trial wedge method is large than the value of Rankine's method. Finally, in this study the reasonable method for calculating the pressure and the mobilized angle that can be applied to the routine design of port structures is proposed. The proposed method can decide the earth pressure with length of a heel and a self weight of retaining wall according to sliding angle toward the wall.

• Journal of the Korean Geosynthetics Society
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• v.19 no.3
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• pp.9-21
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• 2020

In this study, the design method of the combined sheet pile was considered in the coastal landfill where sandy and clayey soils are mixed, and the behavior in excavation was analyzed. It was confirmed from the elasto-plastic analysis that the predicted behavior of the temporary facilities of earth retaining differs according to the type of the combined sheet pile method (Built up, Interlocking, Welding) and the analysis method (soldier pile method, continuous wall method). In the case of sheet pile member force, the results of the continuous wall analysis method predicted the most conservative results. When the stress ratio (calculation/allowance) of each member was analyzed based on the maximum member force of the combined sheet pile method, the maximum value was obtained for bending moment in the side pile and combined stress in the case of the strut. As a result of finite element analysis, the member force of the side pile was the largest in the short-term effective stress analysis condition, while the compressive force of the strut was large in the consolidation analysis. When comparing the results of the elasto-plastic analysis and the finite element analysis, the shear force of the side pile and the axial force of the strut were greatly evaluated in the elasto-plastic analysis, and the bending moment of the side pile was the largest in the short-term effective stress condition of the finite element analysis. In addition, the displacement of the side pile was predicted to be greater in the finite element analysis than in the elasto-plastic analysis.

• Journal of the Korean Geotechnical Society
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• v.28 no.11
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• pp.41-52
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• 2012

Suction drain method can directly apply vacuum pressure to the soft ground through vertical drains so it can make hardening zones around them. These hardening zones make steeply lower the discharge efficiency of the pore water with decreasing permeability. This paper considered a stepped vacuum pressure to minimize a hardening zone which is one of the important parameters that can decrease discharge efficiency. A series of laboratory tests were conducted in order to examine the effect of the hardening zones and to evaluate their effects to the ground improvements with varying durations which applied stepped vacuum pressures(-20kPa, -40kPa, -60kPa and -80kPa) with Busan marine clay. According to strength(CPT), water content test and theoretical investigation indicate a size of the hardening zone within 7cm and the decreasing ratio of permeability about 2.0~4.0. Also, the total settlements are larger for the stepped vacuum pressure than the instant vacuum loading. The application time with vacuum pressure is determined considering the geotechnical properties of the interested clays. Results of numerical analysis show that consolidation behavior is appropriate to measurement for considering hardening zones.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.53-66
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• 2023

In this study, the results of the elasto-plastic beam analysis, finite element analysis and optimization design of the steel pipe sheet pile applied as an earth retaining wall under the deep excavation were presented. Through this study, it was found that the high-strength and sea resistant steel pipe has high allowable stress, excellent structural properties, favorable corrosion, and high utilization as an earth retaining wall, and the C-Y type joint has significantly improved the tensile strength and stiffness compared to the traditional P-P type. In addition, it was investigated that even if the leak or defect of the wall occurs during construction, it has the advantage of being able to be repaired reliably through welding and overlapping. In the case of steel pipe wall, they were evaluated as the best in views of the deep excavation due to the large allowable bending stress and deformation flexibility for the same horizontal displacement than CIP or slurry wall. Elasto-plastic and finite element analysis were conducted in consideration of ground excavation under large-scale earth pressure (uneven pressure), and the results were compared with each other. Quantitative maximum value were found to be similar between the two methods for each item, such as excavation behavior, wall displacement, or member force, and both analysis method were found to be applicable in design for steel pipe sheet pile wall. Finally, it was found that economical design was possible when determining the thinnest filling method with concrete rather than the thickest hollow shape in the same diameter, and the depth (the embedded length through normality evaluation) without rapidly change in displacement and member force.

• Journal of the Korean Geotechnical Society
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• v.26 no.5
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• pp.37-48
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• 2010

In this study, the seepage flow monitoring method by the hydraulic head loss rate was developed for the purpose of application to offshore construction site enclosed by cofferdams in which seepage force varies periodically. The amount of the hydraulic head loss rate newly defined in this graph was in a range between 0 and 1. The zero of the rate means the existence of flow with no seepage resistance. The 1 of the rate means no seepage flow through the ground. The closer to 1 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows is stable. The closer to 0 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows was unstable and the higher the possibilities of existence of empty space or of occurrence of piping on the seepage flow pass in the ground is. The hydraulic head loss graph makes it possible to monitor sensitively the situation of seepage flow state, and the graph helps to understand easily the seepage flow state at the specific section on the whole cofferdam.