• Journal of Ocean Engineering and Technology
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• v.4 no.2
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• pp.35-40
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• 1990

해양 산업에서 심해로의 이동은 해양 구조물의 계류 장치의 중요성을 부각시켰고 그에 따른 기본적인 연구로서의 케이블 동력학에 대한 흥미를 일깨웠다. 거친 해상에서 케이블에 형성될 수 있는 큰 동장력과 기하학적 비선형성의 고려는 케이블의 비선형적 거동 해석에 주요 인자가 될 것이다. 또한 매우 큰 동장력 증폭에 의한 음의 큰 동장력은 케이블의 양의 정장력을 초과할 수 있고, 따라서 전체장력은 영 또는 음이 될 수 있다. 비선형 유체 항력을 포함한 모든 비선형성을 갖는 케이블의 이론적 해석 모델을 개발하고, 수치 결과와 기존의 실험 결과를 비교한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.11
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• pp.964-969
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• 2003

The objective of this study is to investigate the effect of surfactant on the onset of Marangoni convection adapting a non-linear surface equation of state. The surface tension gradient with respect to the absorbate concentration, ${\gamma}$, is linearly related to the surface concentration of a surfactant with a coeffcient $x_{A}$. The numerical results show that the role of the initial surfactant concentration to Marangoni instability changes from the stabilizer to the destabilizer depending on the change of the sign of $x_{A}$ from negative to positive. It is concluded that for $x_{A}$>0 there is a critical modified Marangoni number of surfactant $M_{Ac}$ $^{*}$ above which liquid layer is always unstable against long wave disturbances.rbances.

• The Korean Journal of Physiology
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• v.16 no.1
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• pp.13-23
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• 1982

Effects of external pH and potassium concentrations on the electrical and mechanical properties were investigated on rabbit papillary muscle. Papillary muscles were perfused in horizontal chamber with Tris Tyrode solutions and action potential along with isometric tension was recorded simultaneously. Potassium concentrations were varied between 1 and 12 mM at low(6.9), normal(7.4) and high (7.9) external pH. The following results were obtained: 1) On rasing the potassium concentration from 1 to 12 mM resting membrane potentials decreased from $-88.8{\pm}2.8$ to $-66.4{\pm}1.2\;mV$ at normal pH and the amplitude of action potential decreased from $115.1{\pm}0.7$ to $97.5{\pm}2.8\;mV$. On lowering the potassium concentration, membrane hyperpolarized and at 1 mM potassium concentration resting potentials were $-107{\pm}2.2\;mV$. Duration of action potential especially $APD_{60}{\sim}APD_{90}$ increased($APD_{90}$: $214{\pm}15.8\;ms$ at 1 mM $K^+$ to $287{\pm}18.1\;ms$ at 12 mM $K^+$). 2) During acidosis membranes hyperpolarized by more than 20 mV within 1 min. and then slow recovery was observed during the following 10 min. During alkalosis membranes depolarized about 10 mV, which were maintained until washing with normal Tyrode solutions. 3) On lowering the external pH(7.9-6.5), duration of action potential increased progressively and it was most prominent at pH 6.5 and $K^+$ 1mM. 4) Magnitude of developed tension was $0.6{\pm}0.14\;g/mm^2$ at normal pH and potassium concentration (stimulus frequency : 60/min). Relative isometric tension to normal value increased along the increment of stimulus frequency($44.2{\pm}4.2%$ at 6/min to $271{\pm}86.7%$ at 180/min). Force-frequency relations were altered quantitatively during the perfusion with different external pH solutions. 5) Developed tension did not show marked variation within the range of $2{\sim}8\;mM$ potassium concentrations. Positive inotropism was observed at less than 2 mM $K^+$ and negative inotropism beyond 12 mM $K^+$ concentrations. From the above results we concluded that the effects of potassium ion concentration on electrical and mechanical properties of rabbit papillary muscle are related to the changes in surface negative charge due to acid base disturbances.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.193-201
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• 2023

In this study, a nonlinear truss finite element is developed to analyze structures with negative Poisson effect-induced tensile buckling. In general, the well-known buckling phenomenon is a stability problem under a compressive load, whereas tensile buckling occurs because of local compression caused by tension. It is not as well-known as classical buckling because it is a recent study. The mechanism of tensile buckling can be briefly explained from an energy standpoint. The nonlinear truss finite element with a torsional spring is formulated because the finite element has not been reported in the literature yet. The post-buckling analysis is then performed using the generalized displacement control method, which reveals that the torsional spring plays an important role in tensile buckling. Structures that mimic a negative Poisson effect can be constructed using such post-buckling behaviors, and one of the possible applications is a mechanical switch. The results obtained are compared to those of analytical solutions and commercial finite element analysis to assess the validity of the proposed finite element model. The numerical results show that the developed finite element model could be a viable option for the basic design of nonlinear structures with a negative Poisson effect.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.135-144
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• 2012

The purpose of this research study is to find factors associated with burnout in social workers in public sector. This study examined the impact of social support and job-related tension on burnout of social workers in public sector. A participant of 300 social workers in public sector were recruited from Inchen city and completed the questionnaires during August, 2011. Data were entered into simple regression and hierarchical multiple regression analyses. First, women had a little higher mean score of burnout than men. However, this was not a statistically significant difference. Job Classification and year of work experiences were very important predictors for burn-out of social workers in public sector. Second, there was a strong positive relationship between job-related tension and burnout. Third, there was a strong negative relationship between social support and burnout. As the perception about social support by social workers increased, the level of burnout tended to decrease. Finally, the set of analyses examined the impact of social support after controlling for effects of demographic variables and job-related tension. Perceived social support, job-related tension made a significant contribution in burnout. The results of this research study provide several implications for social work practices. More research is needed regarding the effects of social support and job-related tension on burnout of social workers in public sector. For social works in public sector, supervision from supervisors appeared to have a protective effect against social workers' burnout.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.2
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• pp.1-7
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• 2021

The concrete deck slab at the continuous span support of the steel box girder bridge is a structure that is combined with the upper flange. It is a structure that can cause tension cracks in the deck slab at the support causing problems such as durability degradation in long span bridges. This is because the tensile stress in the longitudinal direction of the slab exceeds the design tensile strength due to the effects of dead load and live load when applying a long span. Accordingly, it is necessary to control tensile cracking by adding a reinforcing bar in the axial direction to the slab at the support and to introduce additional compressive stress. To solve this problem, a structural system of a steel box girder bridge was proposed that introduces compressive stress as PS steel wire tension in the tensile stress section of the upper slab in the continuous support. The resulting structural performance was compared and verified through the finite element analysis and the steel wire tension test of the actual specimen. By introducing compressive stress that can control the tensile stress and cracking of the slab generated in the negative moment through the tension of the PS steel wire, it is possible to improve structural safety and strengthen durability compared to the existing steel box girder bridge.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.104-118
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• 1997

Consumers experience various cognitive and emotional contents of clothing through postpurchase process. These experiences may affect consumer satisfaction as well as brand attitude toward clothing products. The purpose of this study was to examine the effects of consumption experiences on the brand attitude toward clothing products. The research questions for accomplishing the purpose of this study were to investigate 1) the dimension of consumption experiences, 2) relationships among consumption experience, satisfaction and brand attitude toward clothing. The sample of this study was consisted of 431 females. The survey method, and factor analysis and regression were utilized for this study. The results were as follows; First, it was found out the consumption was composed of two dimensions such as cognitive and emotional experiences. According to the result of factor analysis, the cognitive experiences through consumption process were composed of 6 factors, that is, the suitability, fitness, utility/economy, sewing, deformation, and management. And emotional experiences were composed of 5 factors, that is, unpleasure, activeycomfort, inter-oriented pleasure, extra- oriented pleasure, tension. Also emotional experiences could be composed of two dimensions, that is, positive and negative emotion. The positive emotions were included pleasure and active/comfort. The negative emotions were included unpleasure and tension. Second, the result of path analysis showed that consumption experiences were related to satisfaction and brand attitude. A satisfaction influenced on brand attitude more strongly than others. And sewing, activejcomfort, extra-oriented pleasure out of cognitive and emotional experience factors affected to brand attitude directly. Satisfaction was also influenced by cognitive and emotional factors, and was the important mediator in forming brand attitude toward clothing through consumption experience. Above results imply that consumer experience multidimensional cognitive and emotional aspects of clothing through consumption process. The cognitive and emotional aspects consisting of consumption experiences, satisfaction, and brand attitude are interrelated causally. Therefore, experience related variables could be the antecedents of satisfaction and brand attitude. The satisfaction and positive emotion could be also important factors in brand attitude toward clothing.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4939-4944
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• 2014

The purpose of this study was through a survey of awareness of cancer and cancer screening of Korean community residents to identify the stereotypes of cancer and bases for development of improved screening programs for early detection. Subjects were residing in South Korea Gangwon-Province and were over 30 years and under 69 years old. The total was 2,700 persons which underwent structured telephone survey questionnaires considered with specific rates of gender, region, and age. For statistical analysis, PASW Statistics 17.0 WIN was utilized. Frequency analysis, the Chi-square (${\chi}^2$) test for univariate analysis, and logistic regression analysis were performed. The awareness of cancer and cancer screening in subjects differed by gender, region and age. For the idea of cancer, women thought about death less than men (OR: 0.73, p<0.001). On the other hand, women had negative thoughts - fear/terror/suffering/pain/pain - more than their male counterparts (OR: 2.04, p<0.001). Next, for the idea of cancer screening, women recognized fear/terror more than men (OR: 1.38, p<0.01). The higher age, the more tension/anxiety/worry/burden/irritated/pressure (OR: 1.43, p<0.01, OR: 2.15, p<0.001, OR: 2.49, p<0.001)). People may be reminded of fear and death for cancer and of fear, terror, tension and anxiety for cancer screening. To change vague fear and negative attitudes of cancer could increase the rate of cancer screening as well as help to improve the quality of life for community cancer survivors and facilitate return to normal social life. Therefore, it is necessary to provide promotion and education to improve the awareness of cancer and cancer screening.

• Computers and Concrete
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• v.3 no.4
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• pp.213-233
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• 2006

Over the past years techniques for non-linear analysis have been enhanced significantly via improved solution procedures, extended finite element techniques and increased robustness of constitutive models. Nevertheless, problems remain, especially for real world structures of softening materials like concrete. The softening gives negative stiffness and risk of bifurcations due to multiple cracks that compete to survive. Incremental-iterative techniques have difficulties in selecting and handling the local peaks and snap-backs. In this contribution, an alternative method is proposed. The softening diagram of negative slope is replaced by a saw-tooth diagram of positive slopes. The incremental-iterative Newton method is replaced by a series of linear analyses using a special scaling technique with subsequent stiffness/strength reduction per critical element. It is shown that this event-by-event strategy is robust and reliable. First, the model is shown to be objective with respect to mesh refinement. Next, the example of a large-scale dog-bone specimen in direct tension is analyzed using an isotropic version of the saw-tooth model. The model is capable of automatically providing the snap-back response. Subsequently, the saw-tooth model is extended to include anisotropy for fixed crack directions to accommodate both tensile cracking and compression strut action for reinforced concrete. Three different reinforced concrete structures are analyzed, a tension-pull specimen, a slender beam and a slab. In all cases, the model naturally provides the local peaks and snap-backs associated with the subsequent development of primary cracks starting from the rebar. The secant saw-tooth stiffness is always positive and the analysis always 'converges'. Bifurcations are prevented due to the scaling technique.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.74-81
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• 2020

Objective: To prevent low back pain, an objective evaluation tool to evaluate pelvic mobility and exercise to improve the flexibility of the lumbar region is needed. The purpose of this study was to compare the results of pelvic mobility measurements using the Wii Balance Board (WBB) and Sensbalance Therapy Cushion (STC), evaluate the usefulness of the STC as a tool for measuring pelvic mobility. Design: Cross-sectional study. Methods: Fifty healthy subjects participated in this study. The subjects performed pelvic mobility range, proprioception, reaction time and reach of the arm using the STC. The pelvic movement parameter was measured two times to determine the intra-rater reliability. To measure the correlation between lumbar muscle tension and pelvic mobility, Myovision was used to measure tension of L4, L5 level erector spinae muscle. Correlations between measured variables were checked to determine the validity of the pelvic mobility assessment tool. Results: STC showed high test-retest reliability in pelvic tilt measurement and reaching task [intraclass correlation coefficients (3,1)=0.804-0.915]. The relationship between WBB and STC showed a significant positive correlation with the pelvic tilt and reaching task (p<0.05). Posterior tilt and erector spinae activation (Lt. L5) showed a significant negative correlation (p<0.05). Left, right tilt and erector spinae activation (L5) showed a significant negative correlation (p<0.05). Conclusions: This study confirmed the advantages of the STC and found efficiency as an objective measuring device of pelvic mobility.