• Nuclear Engineering and Technology
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• 제30권5호
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• pp.387-395
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• 1998

In general, the laminated rubber bearing (LRB), a composite structure laminated with the elastic rubber and steel plates, has a complex hysteretic nonlinear characteristics in relationships between the restoring force and shear deflection. The representative nonlinear characteristics of LRB include the change of hysteresis loop with cyclic shear deflections and the hardening effects at large shear deflection regions. Changes of the hysteresis loop of LRB with cyclic shear deflections affect the horizontal stiffness and the damping characteristics. The hardening behavior of LRB in large shear deflection region results in an increased horizontal stiffness and therefore, has a great impacton the seismic responses. In this paper, the seismic response analysis is carried out using the modified hysteretic bi-linear model of LRB, which takes into account the hysteresis loop change and the hardening behavior with cyclic shear deflection. The results on seismic responses are compared with those obtained using the widely used hysteretic hi-linear model. The new model is found to reveal the greater amount of peak acceleration response.

• 한국수소및신에너지학회논문집
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• 제30권5호
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• pp.385-394
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• 2019

The analysis of temperature behavior of a hydrogen tank during refueling is of significance to clarify the safety of the compressed hydrogen storage in vehicles since the temperature at a tank rises with inflow of hydrogen. A mass balance and an energy balance were combined to obtain analytical model for temperature change during the hydrogen refueling. The equation was coupled to Peng-Robinson-Gasem (PRG) equation of state (EOS) for hydrogen. The PRG EOS was adopted after comparison with other four different cubic EOSs. A parameter of the model was determined to fit data from experiments of various inlet flow rates and temperatures. The temperature and pressure change with refueling time were obtained by the developed model. The calculation results revealed that the extent of precooling was more effective than the flow rate control.

• 한국정밀공학회지
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• 제27권2호
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• pp.94-101
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• 2010

Composite materials have a higher specific strength and modulus than traditional metallic materials. Additionally, these materials offer new design flexibilities, corrosion and wear resistance, low thermal conductivity and increased fatigue life. These, however, are susceptible to impact damage due to their lack of through-thickness reinforcement and it causes large drops in the load-carrying capacity of a structure. Therefore, the impact damage behavior and subsequently load-carrying capacity of impacted composite materials deserve careful investigation. In this study, the residual strength and impact characteristics of plain-woven CFRP composites with impact damage are investigated under axial tensile test. Impact test was performed using drop weight impact tester. And residual strength behavior by impact was evaluated using the caprino model. Also we evaluated behavior of residual strength by change of mass and size of impactor. Examined change of residual strength by impact energy change through this research and consider impactor diameter in caprino model.

• 대한지역사회영양학회지
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• 제5권4호
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• pp.615-623
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• 2000

Under the assumption that people go through stages in making dietary behavior change, this study was attempted to apply the stages of a change model for fat intake by examining the associations of social psychological variables with stages of change in dietary fat reduction. Derived from social psychological theories, 10 social psychological variables on motivational beliefs(6), social influence(3) and self-efficacy(1) related specifically to selecting every day diets low in fat were constructed. Fat and energy intakes were assessed by a short form semi-quantitative food frequency questionnaire. The associations of stages of change with motivational beliefs, social influence, and self-efficacy variables and energy and fat intakes were assessed in 333 female adults from large cities in Korea. Dietary stage groups differed significantly on most of the social psychological variables in ways predicted by theory. Motivational factors that lead to a psychological state of readiness to take action were important in the early stages of the dietary change process. Social influences were more important in the stages as people decide to take action. Self efficacy and motivational beliefs, particularly, reduction of perceived barriers were important in maintaining fat reduction behavior. The results of our study indicate differences in stages of change in fat reduction behavior in terms of nutrient intakes and social psychological correlates and suggests that adding a time dimension to social psychological models increases our understanding of dietary change, which assist us in designing nutrition education interventions that are more appropriately targeted by stage of change. (Korean J Community Nutrition 5(4) 615∼623, 2000)

• 한국기후변화학회지
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• 제6권2호
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• pp.121-131
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• 2015

As the temperature has changed by climate change, changes in its own characteristic values of the chemical substance or the movement and distribution of chemicals take place in accordance with the changes of hydrological and meteorological phenomena. Depending on the impact of climate change on the chemical behavior, it is necessary to understand and predict quantitative changes in the dynamics of the environment of pollutants due to climate change in order to predict in advance the occurrence of environmental disasters, and minimize the impact on the life and the environment after the incident. In this study, we have analysed and compared chemical fate models validated by previous studies in terms of model configuration, application size and input/output factors. The potential models applicable to municipal and industrial areas were selected on the basis of characteristic of each model, availability of input parameters and consideration for climate change, identified the problems, and then presented an approach to improve applicability.

• 센서학회지
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• 제15권1호
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• pp.34-39
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• 2006

This study provides the electrical model of combustible catalytic gas sensor. Physical characteristics such as thermal behavior, resistance change were included in this model. The finite element method analysis for sensor device structure showed that the thermal behavior of sensor is expressed in a simple electrical equivalent circuit that consists of a resistor, a capacitor and a current source. This thermal equivalent circuit interfaces with real electrical circuit using two parts. One is 'power to heat' converter. The other is temperature dependent variable resistor. These parts realized with the analog behavior devices of the SPICE library. The gas response tendency was represented from the mass transferring limitation theory and the combustion theory. In this model, Gas concentration that is expressed in voltage at the model, is converted to heat and is flowed to the thermal equivalent circuit. This model is tested in several circuit simulations. The resistance change of device, the delay time due to thermal capacity, the gas responses output voltage that are calculated from SPICE simulations correspond well to real results from measuring in electrical circuits. Also good simulation result can be produced in the more complicated circuit that includes amplifier, bios circiut, buffer part.

• 지역사회간호학회지
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• 제22권2호
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• pp.173-183
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• 2011

Purpose: This study was to compare the Transtheoretical Model components according to the stage of change in smoking cessation behavior and identify factors associated with preparation to quit smoking among college smokers. Methods: Data were collected from 224 undergraduate students using the self-report questionnaire. The survey variables comprised the stage of change in smoking cessation, self-efficacy, and decisional balance and process of change in smoking cessation. Results: There were significant differences in self-efficacy, cons of smoking, and the process of change according to the stage of change in smoking cessation behavior. Cons of smoking and self liberation were significant factors related to the preparation stage of smoking cessation. Conclusion: Strategies to enhance cons of smoking and self liberation in college smokers will be an important intervention component to prepare and plan smoking cessation in future studies.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.131-138
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• 2001

The purpose of this study is to investigate size effect on inelastic behavior of reinf bridge piers subjected to cyclic load. A computer program, named RCAHEST(Reinforced Co Analysis in Higher Evaluation System Technologr), for the analysis of reinforced concret was used. Material nonlinearity is taken into account by comprising tensile, compressiv models of cracked concrete and a model of reinforcing steel The smeared crack app incorporated. In boundary plane at which each member with different thickness is conne discontinuous deformation due to the abrupt change in their stiffness can be taken into introducing interface element. The effect of number of load reversals with the same d amplitude has been also taken into account to model the reinforcing steel. To determine th on bridge pier inelastic behavior, a 1/4-scale replicate model was also loaded for compar full-scale bridge pier behavior.

• 한국IT서비스학회지
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• 제12권2호
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• pp.131-152
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• 2013

Many studies have reported that software piracy is prevalent in today's society. As software is more closely integrated with across industries, software piracy would put more burdens on national economy. In spite of software anti-piracy efforts, the phenomenon has been getting worse. It is necessary to change the focus of current deterrence strategies. For better understanding of unethical behavioral intention, a research model of potential determinants for the software piracy is developed and empirically tested. The results from the study show that the planned behavior model variables-attitude, subjective norms, and perceived behavioral control-have impact on intention to commit software piracy. In addition to the variables, past behavior, perceived benefits and risk were found to be significant predictors of attitude toward software piracy. However, neither attitude nor intention was influenced by facilitating conditions. Moreover, the effect of past piracy behavior on attitude was strongly mediated by perceived benefits. Implications for research and practice are discussed.

• 한국건강관리협회지
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• 제3권2호
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• pp.189-198
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• 2005

This study examined the applicability of the transtheoretical model(TTM) to understanding exercise behavior of early adulthood. A cross-sectional study was conducted and data wee collected from 1618 adults aged from 20 to 39 through internet survey. Major conclusions wee as follows: 1. Stage distribution for exercise behavior was 15.6%, 26%, 25%, 19%, 14.4% for precentemplation, contemplation, preparation, action, maintenance stages, respectively. 2. Behavioral processes were more frequently utilized than cognitive processes for action and maintenance stage. 3. Self-reevaluation, social liberation and reinforcement were frequently used in precontemplation, contemplation and preparation stages. Self-reevaluation, reinforcement, self-liberation were frequently used in action and maintenance stages. 4. Pros of exercise behavior began to be higher than cons of exercise behavior from the actions stage and continued to increase to maintenance stage. 5. Self-efficacy was higher in action stage than precontemplation, contemplation and preparation stages and the highest in maintenance stage.