• Journal of the Korean Geotechnical Society
• /
• v.28 no.9
• /
• pp.57-67
• /
• 2012

In the design for piled rafts, the load capacity of the raft is in general ignored and the load capacities of pile are only considered for the estimation of the total load carrying capacity of the piled raft. The axial resistance of piled raft is offered by the raft and group piles acting on the same supporting ground soils. As a consequence, pile - soil - raft and pile - soil interactions, occurring by stress and displacement duplication with pile and raft loading conditions, acts as a key element in the design for piled rafts. In this study, a series of centrifuge model tests has been performed to compare the axial behavior of group pile and raft with that of a piled raft (having 16 component piles with an array of $4{\times}4$) at the stiff and soft clays. From the test results, it is observed that the interactions of piles, soil, and raft has little influences on the load capacities of piles and raft in piled rafts compared with the load capacities of group piles and raft at the same clay soil condition.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.389-402
• /
• 2018

This study investigated the influence of parenting attitudes and parenting efficacy on parents' educational needs to establish basic data for educational programs and intervention strategies to promote parenting attitudes and parenting efficacy among married immigrant women. This was a study of descriptive correlation among 154 married immigrant women with adolescent children. The results showed that family support and spousal support influenced parenting behavior and stress associated with childcare. Specifically, spousal support and family support were negatively correlated (r = 0.046, F = 3.629 p < 0.05) with parenting attitude (r = 0.046, F = 3.629 p < 0.05). Only spousal support was negatively correlated (r =0.227, F = 7.11 .<.01) with stress from children. Moreover, higher support from the spouse and family was associated with lower parenting stress and higher spousal support was associated with lower stress associated with the relationship with the child. The results of this study will facilitate development of a structured education program for married immigrant women to enhance parenting attitudes, as well as to reduce parenting stress.

• Journal of the Korean Geosynthetics Society
• /
• v.18 no.3
• /
• pp.45-53
• /
• 2019

In this study, it was analyzed the cases of bored PHC piles designed for the building foundations. The overall length of the piles varies within a maximum of 35 m. However, the average length was 17.0 to 18.9 m depending on the kind of the bedrock, with no significant difference. The socket length entered into the bedrock was designed with approximately 58% of the whole piles being 1m, the minimum length of the specification, and up to 5m. Although the range in design efficiency was very large, on average it was about 70%, consistent with the usual known extent. Applications with low design efficiency were mainly shown on the foundation of low-rise buildings or rides with low design load. On the weathered rock, the design load, which governs the design result was widely distributed at 65 to 97% of allowable bearing capacity of ground. The ratio of allowable axial load of piles to allowable bearing capacity of ground is also widely distributed between 36 and 115%, so optimization efforts are required along with design efficiency. On the other hand, the allowable bearing capacity on the soft or hard rock was highly equal, mostly within 90% of the allowable axial load of piles. In the design, the end bearing resistance averaged over 75% of the allowable bearing capacity. However, the results of the dynamic pile load test show that the end bearing resistance was predominant under the E.O.I.D conditions, and in some cases, the end bearing resistance was at least 25% under the restrike conditions.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.8
• /
• pp.5-11
• /
• 2006

A series of large scale plate loading tests are performed to assess bearing capacity characteristic of dredged and reclaimed ground that is reinforced by bamboo net and geotextile as a surface strengthen method. Bearing capacity ratio is distributed from 3.46 to 6.03 for bamboo net and from 2.19 to 3.59 for Geotextile In case of bamboo net, BCR was obtained from 1.6 to 1.7 times than Geotextile. As the comparison of each bearing capacity from test and theory shows, bearing capacity theory for geotextile was not suited for bamboo net. The bearing capacity analysis reinforced by bamboo net shows a good relationship between sand mat thickness (H) / bamboo net space (S), and bearing capacity ratio (BCR).

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.11
• /
• pp.47-54
• /
• 2013

This study is the basic research to develop the customized base module for modular road system. A case study was carried out on designs of base module for soft soil condition. Two types of base module was proposed; crossbeam module and crossbeam-pile module. Based on the case study, it was verified crossbeam-pile module is suitable for soft soil condition and the optimum dimension of crossbeam-pile module for modular road system constructed on soft soil was determined. For development of the optimal base modular for modular road system, it is needed in the future to build a data base about ground and roadbed of road construction sites and to classify and systemized base modules according to soil conditions through many case studies.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.10
• /
• pp.4970-4978
• /
• 2013

This study was performed to determine the relationships between social supports and depression symptoms among high school students in urban areas. The self-administered questionnaires were given to 514 students located in Daejeon city during the period from April 1st to May 31th, 2010. As a results, the level of depression symptoms was significantly higher in proportion to lower level of social support of families and friends. And the level of depression symptoms was positively correlated with level of social support of families and friends. In multiple regression analysis, the factors of influence with the level of depression symptoms was sex, school grade, academic achievement, friendship with the school fellow, satisfaction of school life and satisfaction of family life. Especially explanatory powers to the level of depression symptoms increased by social support of families and friends. As a conclusion, the level of depression symptoms among high school students implies closely related with level of social support of families and friends.

• Journal of the Korean Geosynthetics Society
• /
• v.13 no.2
• /
• pp.41-47
• /
• 2014

Various prediction methods for the bearing capacity of helical piles have been introduced with consideration of both the steel shaft and the helix plates attached to the shaft. In this paper, three representative methods, that is, individual bearing method, cylindrical shear method, and torque correlation method are discussed and compared to each other. The prediction methods were verified by comparing with a series of loading test results performed on moderate-size helical piles from the companion paper. As a result, the measured bearing capacity is greater than the bearing capacity predicted by the cylindrical shear method, but smaller than that of the individual bearing method. In addition, the bearing capacity predicted by the torque correlation method is in good agreement with the measured bearing capacity.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.11
• /
• pp.17-25
• /
• 2011

In this study, we considered the bearing capacity of strip footing over clay layers partially replaced by sand. The FEM analysis is performed to calculate the ultimate bearing capacity. Partial replacement is defined by multiples of footing width(B) and inclination of sides. The cases(B'=inf.) of sand layers equal to clay layers are preferentially conducted. The baring capacity of B'=inf. is comparative value for bearing capacity of partial replacement layers. ${\beta}$ is the ratio of ultimate bearing capacity of B'=inf and partial ultimate bearing capacity replacement. ${\beta}$ is used to analyze the characteristic of bearing capacity of clay layers partially replaced by sand. Each of the three undrained shear strengths of clay and friction angles of sand is considered. The result of this analysis shows that ${\beta}$ depends on sand depth.

• Korean Journal of Culture and Social Issue
• /
• v.27 no.4
• /
• pp.505-528
• /
• 2021

The current study examined the differential effects of giving and receiving social support in the elderly when relationships(family, friend/neighbor) are important. For this purpose, the mediation effects of meaning in life on the relationship between giving and receiving social support and self-esteem were analyzed. Self-reporting data of 310 adults aged over 60 living in Busan and Gyeongnam in South Korea were collected regarding giving and receiving social support, meaning of life and self-esteem. The mediation analysis showed that giving social support had a positive effect on self-esteem with the partial mediation effect of meaning in life. Receiving social support, however, showed no significant mediation effect of meaning in life. This pattern was similar regardless of both family and non-family relations. The result that giving social support enhances self-worth in the elderly through meaning in life suggests the importance of social interaction with intimate others as a source of happiness in the elderly.

• Journal of Digital Convergence
• /
• v.19 no.12
• /
• pp.63-77
• /
• 2021

This study aims to explore the differential effects of teacher support on Chinese EFL students' listening ability in a blended learning environment. 87 third-year English-major students in a Chinese university participated in this study and they were randomly divided into an autonomy group (n=22), an emotional group (n=22), a cognitive group (n=22) and a control group (n=21). Each experimental group received relevant teacher support during their 17-week course learning while the control group did not. To confirm the effects of teacher support, pre- and post- listening tests were conducted. The results of the paired t-tests demonstrated that all groups showed statistically significant improvement in their English listening ability. The results of the one-way ANOVA for the post-test revealed that autonomy support and cognitive support were more effective than emotional support in improving students' listening ability. Based on the findings, this study hopes to provide insights for EFL teachers in designing and arranging the activities in a blended course.