• Journal of Family Relations
• /
• v.21 no.4
• /
• pp.27-50
• /
• 2017

Objectives: This study was carried out in order to evaluate the overall process that the caregiving stress of parents of adult children with developmental disabilities affected their life satisfaction through the levels of family resilience, and coping styles on the basis of stress-coping-adaptation model of Lazarus and Folkman(1984). Method: For this purpose, the structured survey was conducted by 394 parents of adult children with developmental disabilities. The data was analysed by AMOS 20.0 version. Results: The findings can be summarized as follows: First, the structural equation model(SEM) analysis was conducted in order to examine the various paths that parents' caregiving stress affected their life satisfaction. The model's goodness-of-fit was fine($x^2=225.20$, df=95, p=000. RMSEA=.06, TLI=.95). There were significant relationships between caregiving stress and family resilience(${\beta}=-.36$, p<.001), emotion-focused coping style(${\beta}=.47$, p<.001), life satisfaction(${\beta}=-.53$, p<.001). Second, family resilience and emotion-focused coping showed mediating effects on the relationship between caregiving stress and life satisfaction. Conclusions: The strategies for enhancing family resilience and social services for applying effective coping methods should be expanded in order to diminish the caregiving stress of parents of adult children with developmental disabilities.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.6 no.1
• /
• pp.41-50
• /
• 2004

The numerical investigation for the effects of blasting-induced vibration on adjacent dam and pore water pressure fluctuation was conducted through solid-water coupled analysis under dynamic loading. The stability of dam was examined by peak particle velocity of core. Pore water pressure distributions were calculated by steady state flow analysis using coupled analysis on ground water and blasting-induced vibration. The influence of pore water pressure and the effective stress distribution in the ground were also investigated. Furthermore, effective stress alteration was examined by applying Finn & Byrne Model to monitor the generation and dissipation of pore water pressure.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.3
• /
• pp.74-83
• /
• 2001

After the concept of fracture mechanics was applied to fatigue crack propagation by Paris. Paris' law is widely used to predict fatigue crack growth behavior. Since Elber proposed the effective stress intensity factor(SIF) and showed a good agreement with experimental results using the proposed SIF, emphasis in crack propagation studies has been placed on measuring the effective stress range ratio. This paper proposes a numerical model to simulate the crack closure and propagation behaviour under various loading spectrum. The validity of the proposed model is checked by comparing with the Toyosada numerical solutions on the crack propagation behaviour. Important insights developed are summarized.

• Structural Engineering and Mechanics
• /
• v.56 no.4
• /
• pp.507-534
• /
• 2015

The present work investigates the behavior of the embankment models resting on soft soil reinforced with ordinary and stone columns encased with geogrid. Model tests were performed with different spacing distances between stone columns and two lengths to diameter ratios (L/d) of the stone columns, in addition to different embankment heights. A total number of 42 model tests were carried out on a soil with undrianed shear strength $${\sim_\sim}10kPa$$. The models consist of stone columns embankment at s/d equal to 2.5, 3 and 4 with L/d ratio equal 5 and 8. Three embankment heights; 200 mm, 250 mm and 300 mm were tested for both tests of ordinary (OSC) and geogrid encased stone columns (ESC). Three earth pressure cells were used to measure directly the vertical effective stress on column at the top of the middle stone column under the center line of embankment and on the edge stone column for all models while the third cell was placed at the base of embankment between two columns to measure the vertical effective stress in soft soil directly. The performance of stone columns embankments relies upon the ability of the granular embankment material to arch over the 'gaps' between the stone columns spacing. The results showed that the ratio of the embankment height to the clear spacing between columns (h/s-d) is a key parameter. It is found that (h/s-d)<1.2 and 1.4 for OSC and ESC, respectively; (h is the embankment height, s is the spacing between columns and d is the diameter of stone columns), no effect of arching is pronounced, the settlement at the surface of the embankment is very large, and the stress acting on the subsoil is virtually unmodified from the nominal overburden stress. When $(h/s-d){\geq}2.2$ for OSC and ESC respectively, full arching will occur and minimum stress on subsoil between stone columns will act, so the range of critical embankment height will be 1.2 (h/sd) to 2.2 (h/s-d) for both OSC and ESC models.

• Mood & Emotion
• /
• v.9 no.2
• /
• pp.78-86
• /
• 2011

Objectives : The aim of this study was to investigate relationship between perceived stress level, cognitive emotion regulation (CER) strategy and hope in group with high depressive symptom and higher-level perceived stress (H-H) and group with high depressive symptom and lower-level perceived stress (H-L) in patients with depression. Method : A total of 85 patients (over score of 16 by Beck depression Inventory; BDI) were surveyed with Cognitive emotion regulation questionnaire (CERQ), Perceived stress scale (PSS), and The state hope scale (SHS). Mean scores of CERQ and SHS were compared between relatively higher perceived stress and lower perceived stress groups. Correlation analysis and multiple linear regression analyses were performed to identify the effect of BDI, PSS and CER strategy on SHS in two groups. Results : In ANOVA, the level of hope and maladaptive CERQ score proved to be significantly lower among the H-H group than among the H-L group, while adaptive CERQ scores were not. In Regression analysis, the effective CER strategy in SHS were 'Refocus on planning' in H-H group, while it was 'Acceptance' CER strategy in H-L group. The final regression model explained 36% of the variance of SHS in H-H group and explained 21% of SHS in H-L group. Conclusion : These findings suggest that 'Refocus on planning' and 'Acceptance' cognitive emotion strategy are helpful in promotion of state hope on depression. Especially, 'Refocus on planning' strategy is more effective in high depressive symptom and high-perceived stress level, while 'Acceptance' strategy help to promote hope in high depressive symptom and low-perceived stress level in patients with depression.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.149-152
• /
• 2008

In structural design provision, maximum punching shear stress of slabs is prescribed as combined stress of direct shear occurred by balanced gravity load and eccentric shear occurred by unbalanced moment. This means that the effect of unbalanced moment is considered to decide the punching shear stress. However, from the resistance capacity standpoint, the effect of unbalanced moment strength is not considered for deciding punching shear strength. For this problem, a model to show unbalanced moment-punching shear interrelation was proposed. In the model, the relation between load effect and resistance capacity in unbalanced moment-punching shear was two-dimensionally expressed. Using the interrelation model, a method how unbalanced moment strength should be considered to decide the punching shear strength was proposed. Additionally, a effective width enlargement factor for deciding the unbalanced moment strength of flat plates with shear reinforcements was proposed. The interrelation model proposed in this paper is very effective for the design because not only punching shear and unbalanced moment strengths but also failure modes of flat plates can be accurately predicted.

• Geomechanics and Engineering
• /
• v.6 no.3
• /
• pp.277-292
• /
• 2014

Soil nailing, as an effective stabilizing method for slopes and excavations, has been widely used worldwide. However, the interaction mechanism of a soil nail and the surrounding soil and its influential factors are not well understood. A pullout model using a hyperbolic shear stress-shear strain relationship is proposed to describe the load-deformation behavior of a cement grouted soil nail. Numerical analysis has been conducted to solve the governing equation and the distribution of tensile force along the nail length is investigated through a parametric study. The simulation results are highly consistent with laboratory soil nail pullout test results in the literature, indicating that the proposed model is efficient and accurate. Furthermore, the effects of key parameters, including normal stress, degree of saturation of soil, and surface roughness of soil nail, on the model parameters are studied in detail.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.6
• /
• pp.253-266
• /
• 2020

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment M_o, S-wave velocity V_s, corner-frequency f_c, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, G_c. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to f_c given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to M_o = 10¹⁷~10¹⁸ Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent V_r-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate G_c with respect to breakdown distance D_c from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

• Anxiety and mood
• /
• v.5 no.2
• /
• pp.75-79
• /
• 2009

In this article, we review the efficacy of early interventions after traumatic incidents and during acute stress disorder (ASD). There are some evidences that psychopharmacological medications such as propronolol, morphine, and hydrocortisone are effective in the prevention of posttraumatic stress disorder (PTSD). Considering the role of selective serotonin reuptake inhibitors in hippocampal neurogenesis and an animal model of PTSD, early administration of selective serotonin reuptake inhibitors is also fairly promising. Other pharmacological treatments including benzodiazepines did not treat ASD nor prevent PTSD. There are good evidences that cognitive behavioral therapy including cognitive therapy and prolonged exposure is a valuable intervention for ASD and the most effective prevention for PTSD. No contolled researches on eye movement desensitization&reprocessing, psychodynamic psychotherapy and hypnotherapy have performed. Recent randomized controlled studies using psychological debriefing did not prove as a useful intervention for the prevention of PTSD until now, although the efficacy of debriefing has been at the centre of controversy.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.605-610
• /
• 2002

The purpose of this study is to develop an analytic model which can describe the behavior or concrete compressive member strengthened by CFS(Carbon Fiber Sheet) with various cross-sectional shapes such as circular. square, and octagonal and various laminate angles. The failure criterion of laminated CFS is based on Tsai-Wu failure criterion. The stress strain model of confined concrete compressive member is based on an equation proposed by Mander. The effective lateral confining pressure is considered and modified according to various cross-sectional shapes. Octagonal cross-section shows the best results in the aspect of ductility, while circular does in compressive strengthening effects. In addition, [0/0/0/0] laminate in which the direction of fiber is parallel to the direction of principal stress shows the superior strength and ductility than other laminates. The analytic results show that strength and ductility of the analytic model depend on the cross-sectional shapes as well as the laminate angles.