• 한국생산제조학회지
• /
• 제25권6호
• /
• pp.517-521
• /
• 2016

General industrial robots are difficult to use for precision assembly because they are operated based on position control. Their position accuracy is also usually higher than the assembly clearance (several tens of ${\mu}m$). In previous researches, force control was suggested as a robotic assembly solution. However, this method is difficult to apply in reality because of speed and cost problems. The RCC provides high speed, but applications are limited because the compliance is fixed, and it cannot detect an assembly condition during a task. A variable passive compliance device (VPCD) was developed herein. The VPCD can detect the assembly condition during tasks. This device can provide proper compliance for successful assembly tasks. The pneumatic system and the Stewart platform with an LVDT sensor were applied for measuring the displacement and variable compliance, respectively. The concept design and analysis were conducted to prove the effectiveness of the developed VPCD.

• 가정과삶의질연구
• /
• 제31권5호
• /
• pp.125-141
• /
• 2013

This research aims to integrate study results through a meta-analysis of previous studies on the variables related with social support for female marriage immigrants. Based on the results, this study established the foundation of an integrated social support system for female marriage immigrants which considers both the functional perspective and structural perspective of social support, and suggested plans for an efficient support system. All social support was positively associated with female marriage immigrants marriage life, child-rearing behavior and attitude, reduction of stress and depression and psychological stability. In relation to the effect size of each variable related with all social support, the marriage variable had the biggest relationship with it, followed by the parenting variable, the psychological variable and the stress variable in that order. With reference to the relationship with related variables according to the sub-domain of social support, from the structural perspective, spousale support showed a high relationship with the marriage variable and the stress variable. It was also especially, very highly related with the marriage variable. In addition, a married woman's family support and expert support had an intermediate relationship with the marriage variable, and the husband's family support and friend support had a low relationship with it. From the functional perspective, material support had a very high relationship with the marriage variable, whereas it had a low relationship with the stress variable and the psychological variable. Emotional support was also highly related with marriage variable, but showed an intermediate or low relationship with the psychological variable and the stress variable. On the other hand, informational support displayed an intermediate relationship with the stress variable and the psychological variable, and a high relationship with the marriage variable. Lastly, evaluative support had a high relationship with the marriage variable and the psychological variable. Based on these results, this study proposed plans for an integrated social support system as follows. First, education ought to be provided for the spouses, and support for marital adjustment should be offered. Second, there plans should be made for continuous bonding with the family of origin, and support should be given to address changes in awareness of the relationship with the husband's parents. Third, it is required to revitalize the local community and self-help groups, and provide the female marriage immigrants with opportunities to participate in social activities.

• Wind and Structures
• /
• 제18권2호
• /
• pp.195-213
• /
• 2014

Recently, the horizontal axis rotor performance optimizer (HARP_Opt) tool was developed in the National Renewable Energy Laboratory, USA. This innovative tool is becoming more popular in the wind turbine industry and in the field of academic research. HARP_Optwas developed on the basis of two fundamental modules, namely, WT_Perf, a performance evaluator computer code using the blade element momentum theory; and a genetic algorithm module, which is used as an optimizer. A pattern search algorithm was more recently incorporated to enhance the optimization capability, especially the calculation time and consistency of the solutions. The blade optimization is an aspect that is highly dependent on experience and requires significant consideration on rotor control strategies, wind data, and generator type. In this study, the effects of rotor control strategies including fixed speed and fixed pitch, variable speed and fixed pitch, fixed speed and variable pitch, and variable speed and variable pitch algorithms on optimal blade shapes and rotor performance are investigated using optimized blade designs. The effects of environmental wind data and the objective functions used for optimization are also quantitatively evaluated using the HARP_Opt tool. Performance indices such as annual energy production, thrust, torque, and roof-flap moment forces are compared.

• 동아시아경상학회지
• /
• 제6권2호
• /
• pp.1-13
• /
• 2018

Purpose - The present research is to investigate the effect of psychological empowerment on turnover intention through job satisfaction and organizational commitment. Research design, data, and methodology - These include turnover intention as dependent variable, psychological empowerment as an independent variable and for mediating variables job satisfaction and organizational commitment. Also nationality of employee is used as a moderating variable. Survey data was collected was total 886 respondents from 345 Korean, 313 Chinese, 228 Japanese. Data analysis was conducted with SPSS to test reliability of variables with Cronbach's alpha and one variable confirmatory factor analysis to test common method bias. And regression analysis was conducted to confirm relationship among variables. AMOS was used for path analysis and to analysis moderating effect of employees' country. Results - The results of regression indicate that psychological empowerment increase job satisfaction, affective commitment, normative commitment and turnover intention. Job satisfaction, affective commitment and normative commitment decrease turnover intention. As for the moderating role of country, it seems that country does matter. Conclusions - Main conclusions of this research implicate that to decrease employee turnover intention company need to manage psychological empowerment, job satisfaction, and organizational commitment. Also there is need to consider similarity and difference in managing employees of Korea, China and Japan employees. Manager need to verify direction and importance of each antecedent then apply to employees.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
• /
• pp.273-276
• /
• 1988

Forced commutated cycloconverters are capable of conversion from a fixed 3 phase source to 3 phase unrestricted variable frequency, variable voltage. They are able to accept regenerative power and the input displacement factor is controllable. Furthermore, the input current and the output current waveforms are closed to sinusoid.

• 한국경영과학회지
• /
• 제17권3호
• /
• pp.171-180
• /
• 1992

This paper proposes a solution approach to linear problems with many constraints of variable upper bound (VUB) type. This type of constraints are commonly found in various scheduling type problems for which tighter bounds are essential to achieve an efficiency in enumeration. An analytical framework based on factorization is adopted to devise a solution approach to the problem and extend it for more generalized VUB problem (GVUB). This research shows why the VUB type constraints are amenable to the factorization and gives a unified approach to generalized upper bound(GUB) problems, VUB problems and GVUB problems. Implementation issues are also included.

• 로봇학회논문지
• /
• 제11권1호
• /
• pp.26-32
• /
• 2016

A variable release torque-based compliance spring-clutch (VCSC) is presented. VCSC is a safe joint to reduce the impact of collisions between humans and robots. It is composed of four functional plates, balls, springs to make some functions in compliant movement, release mechanism, gravity compensation during its work. Also, it can estimate torque applied to a joint by using distance sensor and parameters of cam profile. The measured variable torque of prototype is 4.3~7.6 Nm and release torque is 4.3 Nm. In our future studies, a calibration for torque estimation will be conducted.

• 한국경영과학회지
• /
• 제31권3호
• /
• pp.127-143
• /
• 2006

While e-learners' satisfaction would be determined by qualify of e-learning environment including learning management systems, learning contents and interactions, the influence of quality on satisfaction can be changed by e-learners' self-regulated efficacy The objective of this study is to show difference of the relationship between qualify and satisfaction In e-learning by self-regulated efficacy. For this purpose, we propose a research model which consists of five quality factors in e-learning as explaining variables, satisfaction as a result variable and self-regulated efficacy as a control variable. For empirical test of this model, the sample is collected from e-learning classes in a college and divided into two groups by self-regulated efficacy in order to analyze the effects of control variable. By multi-group analysis, we show two groups are different from each other in the relationship between quality and satisfaction of e-learning environment.

• Journal of Electrical Engineering and Technology
• /
• 제3권2호
• /
• pp.254-262
• /
• 2008

This paper presents an active use of doubly-fed induction-generator(DFIG)-based variable-speed wind-turbine for voltage control in power system operation. For reasonable simulation studies, a detail dynamic model of a DFIG-based wind-turbine grid-connected system is presented. For the research objective, an innovative reactive power control scheme is proposed that manipulates dynamically the reactive power from the voltage source converter(VSC) with taking into account its operating state and limits.

• Structural Engineering and Mechanics
• /
• 제77권2호
• /
• pp.245-259
• /
• 2021

In this research, the influence of the laminate stacking sequence on thermal stress distribution in symmetric composite plates with a quasi-square cutout subjected to uniform heat flux is examined analytically using the complex variable technique. The analytical solution is obtained based on the thermo-elastic theory and the Lekhnitskii's method. Furthermore, by employing a suitable mapping function, the solution of symmetric laminates containing a circular cutout is extended to the quasi-square cutout. The effect of important parameters including the stacking sequence of laminates, the angular position, the bluntness, the aspect ratio of cutout, the flux angle and the composite material are examined on the thermal stress distribution. It is found out that the circular shape for cutout may not necessarily be the optimum geometry for all stacking sequences. The finite element analysis results are used to validate the analytical solution.