• Steel and Composite Structures
• /
• v.25 no.6
• /
• pp.705-716
• /
• 2017

The objective of this study is to investigate the actual behavior of studs in structures under earthquake load through laboratory tests and numerical simulation. A test program including eighteen specimens was devised with consideration of different concrete strengths and stud diameters. Six of specimens were subjected to monotonically increasing loading while the others were subjected to cyclic loading. Mechanical behavior including the failure mechanism, load-slip relationship, stiffness degradation, energy dissipation and the damage accumulation was obtained from the test results. An accurate numerical model based on the ABAQUS software was developed and validated against the test results. The results obtained from the finite element (FE) model matched well with the experimental results. Furthermore, based on the experimental and numerical data, the design formulas for expressing the skeleton curve were proposed and the simplified hysteretic model of load versus displacement was then established. It is demonstrated that the proposed formulas and simplified hysteretic model have a good match with the test results.

• Journal of Convergence for Information Technology
• /
• v.11 no.4
• /
• pp.161-167
• /
• 2021

This study was conducted to identify the relationship between the dual task performance and driving behavior of the elderly driver in order to identify whether the dual task can be utilized as a test to screen the driving ability of the elderly driver. We surveyed general information and driving-related information for 32 normal elderly drivers, and evaluated Y-DuCog(Yonsei-Dual task Cognitive screening) and the K-DBQ (Korean-Driving Behavior Questionnaire). As a result of the study, the performance of the dual task using the pegboard task and the animal name speaking showed a significant correlation with the score of the violation domain of K-DBQ. With this study, it was possible to confirm the possibility as a test for discrimination of driving ability.

• Korean Journal of Human Ecology
• /
• v.13 no.6
• /
• pp.847-860
• /
• 2004

The purpose of this study is to obtain basic data needed to understand school-age children's parent-child communication style, stress coping behaviors, and child behavior problems. The subject of this study were 362 primary school children (the fourth and the sixth graders) and their mothers in "D" Metropolitan City, Korea. The research tools included standardized parent-child communication style scale (Min,l991), stress coping behaviors scale (Min,1998), and child behavior problems scale (Hun,l996). The data were analyzed using statistical techniques such as Mean, standard deviation, frequency, percentile, t-test, F-test, pearson's correlational analysis, stepwise regression analysis. In the relationship between child perceived parent-child communication style and stress coping behaviors, the children who make open communication with their parents demonstrate high problem-solving, support-seeking coping behavior. The children with closed communication with their parents have high hope expectation, revenge coping behavior. In the relationship between child perceived parent-child communication style and child behavior problem, the children making more closed communication with their parents show more behavior problems. The children with more closed communication with their mothers have more hyperactive behaviors, aggressive behaviors, and immature behaviors, and the children who are making more closed communication retain more anxious behaviors and withdrawn behaviors. In the relationship between child stress coping behaviors and behavior problems, the more problem-solving and support-seeking coping behaviors the children possess, the less problem behaviors they demonstrate. The more hope expectation, revenge coping behavior the children possess, the more problem behaviors they show. With the results above, we can find out that parent-child communication style has an effect on stress coping behavior, and parent-child communication style and stress coping behavior have an influence on child behavior problem.

• The Korean Journal of Community Living Science
• /
• v.17 no.1
• /
• pp.39-53
• /
• 2006

The purpose of this study was to examine the relation of elementary school children's stress and coping behavior in urban and rural areas. The subject included 286 children selected from 4 elementary schools in urban and rural areas. The instruments included the children's stress index and coping behavior questionnaire of the elementary school children. The statistics used from this data were t-test, one-way ANOVA(Duncan test), correlation analysis and multiple regression analysis. This study showed significant differences between urban and rural children's stress in school attainment domain, teacher-school domain, home environment domain and surroundings domain. And urban and rural children was different in active, passive/avoidant and aggressive coping behavior. The stress of urban's children was influenced significantly by the grade and school attainment variales, and the rural children's stress was influenced significantly by the gender variable. The coping behavior of urban's children was influenced by the gender, grade and school attainment variables, and also the rural children's coping behavior was influenced by the above variables. Correlation analysis indicated that children's stress and aggressive coping behavior were relative positive high correlation in urban areas, and children's stress and passive/avoidant coping behavior were positive high correlation in rural areas. It was also found that school attainment, aggressive coping behavior and passive/avoidant coping behavior were significant predictors of urban children's stress, and gender, passive/avoidant coping behavior and aggressive coping behavior were significant predictors of rural children's stress.

• Journal of Families and Better Life
• /
• v.24 no.3 s.81
• /
• pp.73-82
• /
• 2006

The purpose of this study was to investigate the related variables of university students' coping behavior concerning job-searching problems. The subjects were 436 senior students (212 men and 224 women) enrolled in a university in Gyeongbuk Province. Survey questionnaires were used to measure undergraduate students' coping behavior concerning job-searching problems, work commitment, their will to accept downward employment, sex role identity, grade, sex, perceived SES, and major. Data were analyzed by means, standard deviations, t-test, one-way ANOVA, Scheffe' test, and regression. Results are summarized as follows: (1) Male students' level of active and supportive coping behavior was higher than female students'. Male students' level of evasive coping behavior was lower than female students'. Students who perceive their economic condition as negative were higher in active and supportive coping behavior and lower in evasive coping behavior than the students who perceive their economic condition as positive. (2) The students who were strong in work commitment were higher in active coping behavior, and lower in evasive coping behavior than those who were not. (3) The students who were willing to accept downward employment were higher in active coping behavior than those who were not.(4) The students' coping behavior concerning job-searching problems differed according to their sex role identity. (5) Work commitment and sex role identity were influential variables on university students' job-coping behavior.

• Nuclear Engineering and Technology
• /
• v.41 no.2
• /
• pp.179-186
• /
• 2009

This paper presents a thermal creep test under internal pressure and post-test characterization performed on high burnup (68 MWd/kgU) ZIRLO. This research has been done by the CSN, ENRESA, and ENUSA in order to investigate the behavior of advanced cladding materials in contemporary PWRs at higher burnup under dry cask storage conditions. Also, to investigate the hydride reorientation, the cool-down of the samples after the test has been done in a coordinated manner with the internal pressure. The creep results obtained are consistent with the expected behavior from reference CWSR material, Zr-4. During the test, the material retained significant ductility: one specimen leaked during the test at an engineering strain of the tube section of 17%; remarkably, the crack closed due to de-pressurization. Although significant hydride reorientation occurred during the cool-down under pressure, no specimen failed during the cool-down.

• Journal of Welding and Joining
• /
• v.19 no.5
• /
• pp.540-547
• /
• 2001

This study has evaluated the wear behavior of PTA (Plasma Transferred Arc) Inconel 625 and Stellite 6 overlays on Nimonic 80A substrate. Nimonic 80A alloy was also included for comparison. In order to evaluate the wear performance, three-body abrasive wear test and pin-on-disk dry sliding wear test were performed. Microstructural development during the solidification of deposits is also discussed. Wear test results show that the wear rate of Stellite 6 deposit is lower than that of Inconel 625 deposit and Nimonic 80A. The sliding wear resistance of overlay deposits follows a similar trend to the abrasive wear resistance, but for Nimonic 80A. The main wear mechanisms were abrasive wear for Inconel 625 deposit, adhesive wear and delamination for Stellite 6 deposit in pin-on-disk dry sliding wear test and ploughing in three-body abrasive wear test. Cross sectional examinations of the worn surface of pin specimens after pin-on-disk dry sliding wear test implies that the plastic deformation near worn surface has occurred during the wear testing.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.5
• /
• pp.51-56
• /
• 2017

The purpose of this study was to identify differences in cognitive function according to the presence or absence of apraxia and the tasks most relevant to the cognitive function among the various types of tasks in the apraxia test. The subjects were 42 community residents who participated in a cognitive rehabilitation program related to dementia in a Chungbuk area. MMSE-K and BCoS(Birmingham Cognitive Screen) apraxia test were administered to all subjects. The apraxia test includes three types of tasks, gesture production tasks that make meaningful movements according to verbal instructions, gesture recognition tasks that display behavior after make sense of meanings, and meaningless imitation task. Apraxia group(n=30, MMSE-K mean score: 25) showed lower cognitive function than group without apraxia(n=12, MMSE-K mean score: 28). All tasks in the apraxia test showed a significant correlation with cognitive function, but the meaningless imitation task had a negligible correlation. The apraxia test is a good way to assess cognitive function, and it may be more effective to use meaningful behavior to replace cognitive testing.

• Smart Structures and Systems
• /
• v.22 no.6
• /
• pp.643-662
• /
• 2018

One of the methods for investigation of mechanical behavior of materials is numerical simulation. For simulation, its need to model behavior is close to real condition. PFC is one of the rock mechanics software that needs calibration for models simulation. The calibration was performed based on simulation of unconfined compression test and Brazilian test. Indeed the micro parameter of models change so that the UCS and Brazilian test results in numerical simulation be close to experimental one. In this paper, the effect of four micro parameters has been investigated on the uniaxial compression test and Brazilian test. These micro parameters are friction angle, Accumulation factor, expansion coefficient and disc distance. The results show that these micro parameters affect the failure pattern in UCS and Brazilian test. Also compressive strength and tensile strength are controlled by failure pattern.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.977-986
• /
• 2009

Sampling disturbance can introduce considerable errors in the laboratory estimation of geotechnical properties of soils, and the results obtained from sophisticated sampling and careful laboratory testing are not matching with field behavior. Therefore, it is advantage to adopt in-situ testing techniques for the estimation of geotechnical parameters. Therefore, Screw plate loading test, one of new field test technologies, has been investigated in this study. This test can be utilized to find out important properties of soils such as load-displacement, elastic modulus, and shear strength. The screw plate loading test modified from the plate loading test is an experiment underneath ground by inserting a spiral type of auger screw. The structure and characteristics of the screw plate loading test device was examined in detail. In addition, The new screw plate loading test device was manufactured to refer the previous studies. The reliability of developing screw plate loading test was examined through the analysis of the laboratory test.