• Korean Journal of Human Ecology
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• 제21권1호
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• pp.1-14
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• 2012

This research examines the effects of parental attachment as a family-related variable, and depressive mood as an individual variable on anger expression style among Korean college students. Anger expression style was divided into three domains including anger-in, anger-out, and anger-control. The data were collected from 437 college student respondents using a self-administered questionnaire. The results demonstrated that male students displayed higher levels of anger-control compared to females, but no gender-related difference in the level of anger-in and anger-out. In addition, anger-control was positively associated with parental attachment. However, anger control in terms of anger-in and anger-out were negatively related to parental attachment and positively linked to depression. Additionally, parental attachment demonstrated a negative correlation with depressive mood. Multiple regression results indicated that after controlling for the effect of gender, anger-control expression style was influenced by parental attachment but not by depressive mood. In addition, anger-out and anger-in expression styles were influenced by depressive mood but not by parental attachment. Finally, implications for educators and clinicians working with college students and their family are discussed along with some suggestions for future research.

• Journal of Institute of Control, Robotics and Systems
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• 제17권9호
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• pp.863-868
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• 2011

This paper presents a method to achieve a synchronous positioning objective for a dual-cylinder electro-hydraulic system with friction characteristics. The control system consists of a VSC (Variable Structure Controller) for each of the hydraulic cylinders and a PID (Proportional-Integral-Derivative) feedback controller. The PID controller is used for controlling the non-synchronous error generated by both cylinders when motion synchronization is carried out. To enhance the position-tracking performance of the individual cylinders friction characteristics is modeled in model, based on the estimated friction force. The simulation and experimental results show that the proposed method can effectively achieve the objective of position synchronization in the dualcylinder electro-hydraulic system, with maximum synchronization error with ${\pm}2\;mm$.

• The Korean Journal of Food And Nutrition
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• 제26권4호
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• pp.633-637
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• 2013

There is an increasing consumption of Makgeolli in both domestic and foreign markets due to a high interest in Korean traditional alcoholic beverages. However, currently, a standardized system of manufacturing, storing and circulating Makgeolli is not available. Therefore, manufacturing the constant quality of finished products is hardly achieved due to the uncertified quality index of Makqeolli. In particular, quality changes occur as a result of variable initial load of microorganisms during shelf life. Eight different commercially available brands of Makgeolli were obtained, and their initial concentrations of yeasts were measured. One brand with the highest concentration was chosen, and the variable initial concentrations were prepared at a concentration of $10^6{\sim}10^8$ yeast CFU/ml. These Makgeolli samples were heat-treated at 65, 70, 75 or $80^{\circ}C$. It was shown that temperatures higher than $75^{\circ}C$ were needed in order to pasteurize Makgeolli properly. In addition;it is considered that controlling the microorganisms by a standardized system for the processing analysis would improve the quality of Makgeolli.

• Proceedings of the KSME Conference
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.497-501
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• 2000

Flow over a sphere is controlled experimentally at $Re=10^5$ using electro-magnetic actuators. The electro-magnetic actuator developed in this study is composed of the permanent magnet electro-magnet membrane and slot. Eight actuators are placed inside the sphere at equally spaced intervals on a latitudinal plane and the position of the control slot is 76 from the stagnation point. Each actuator generates a periodic blowing and suction through the slot at variable frequencies of $10{\sim}140Hz$ and variable amplitudes by controlling electric signals applied to the electro-magnet. Drag on the sphere measured using a load cell is significantly reduced with control at the forcing frequencies larger than the natural shedding frequency $({\approx}14Hz\;at\;Re=10^5)$, whereas drag is slightly increased at the forcing frequency of 10Hz. It is shown from pressure measurement that the static pressure in the rear surface of the sphere is significantly increased with control, indicating that the separation is delayed due to control. Flow visualizations also show that the detaching shear layer is more attracted to the sphere center with control, the separation bubble size is significantly reduced, and motion inside the bubble is very weak, as compared to the case of uncontrolled flow.

• Asia pacific journal of information systems
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• 제5권1호
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• pp.129-163
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• 1995

Past research linking information technology and organizational structure has been inconclusive and contradictory. The purpose of this study is to resolve some of this confusion by taking into consideration one theoretical issue and three methodological problems. The one theoretical issue is an assessment of the importance of environment as a key external variable constraining both organizational structure and the use of information technology. To date, there has been no systematic, empirical research on the conceptual linkage among all three of these variables. The three methodological issues concern measurement problems associated with (1) controlling for different levels of analysis, (2) establishing a clear operationalization of information technology, and (3) differentiating institutional and questionnaire approaches to data collection. The research results in four conclusions. First, data confirm the environment as a key external variable in the linkage between information technology and organizational structure. Second, three central dimensions of information technology are identified: Growth of Capacity, extensiveness of information technology use, and information technology sophistication. Third, in order to maximize the explanatory power of information technology on other organizational constructs, it is necessary to differentiate between the actual use of information technology as opposed to the mere presence of information technology. Fourth, carefully designed questionnaire measures reveal no significant differences from institutional measures in the assessment of key organizational constructs.

• The Korean Journal of Applied Statistics
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• 제27권2호
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• pp.227-237
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• 2014

We use the regression model with the indicator variables in the case that we use qualitative variables as some predictor variables in regression analysis. We use the ANCOVA(Analysis of Covariance) model when comparing the response variable among groups while statistically controlling for variation in the response variable caused by a variation in the covariate. DD-plot can be used as a graphical exploratory data analysis tool before the confirmatory data analysis. With the DD-plot, we can discriminate the difference of groups in the regression model with the indicator variables or the ANCOVA model at a glance. Making DD-plot does not demand the statistical model assumption about error terms in regression model. Several examples show the usefulness of DD-plots as a graphical exploratory data analysis tool for the regression analysis.

• Transactions of Materials Processing
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• 제8권3호
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• pp.269-275
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• 1999

A variable blank holding force method is proposed to improve deep drawing characteristics of sheet materials. In this method, the blank holding force (BHF) is controlled throughout a drawing process so that the punch load does not exceed a critical value, which is slightly less than the conventional process with the conforming process with the variable BHF is more flexible than the conventional process with the constant BHF and it could be used for improving the product's quality and drawability. In this paper we suggest a method controlling the BHF as a function of punch travel during the forming process. The optimization BHF curves are determined theoretically and experimentally. It is concluded that for the case of optimum BHF control methods the drawn cup height and the drawing formability achieved by this method are increased than those for constant BHF method. Also, as comparing the wall thickness distribution of the cup drawn by the constant BHF and the optimum BHF control, the BHF control reduce the wall thickness variation of the drawn cup at the cup wall and make the cup thickness distribution more uniformly than the constant BHF.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권6호
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• pp.3837-3844
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• 2015

This study recommends effective ways to establish management strategies by suggesting to hog farm managers the importance of variables' tendency to affect MSY according to hog management. Study subjects included 55 hog farms, which were analyzed using factor and regression analyses to determine each variable's importance (22 total) for hog management, using MSY as the dependent variable. In the analysis result, the main necessary factor controlling MSY improvement was vaccination, followed, according to decreasing significance, by stages of growth classified breeding, thermo-humidity and ventilation control, and veterinary and hygienic control. Based on these results, suggesting the main factors to improve MSY to hog farms will establish management strategies.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.518-528
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• 2022

Virtual Reality (VR) has been widely used in various applications to generate realistic virtual environments. A sense of immersion can be increased by providing additional stimuli such as tactile sensation to VR contents. However, it is still challenging to provide a realistic feel for the wind blowing over the whole body by smoothly controlling the airflow. To address this issue, we employ a household electric fan as a wind generating device to provide users with wind experience in VR environments. The wind generating device targets the whole body to mimic the wind we feel outside in our daily life. To do so, we present a low-cost method to smoothly control household fan speed using an Arduino microcontroller. Here, we use the Sinusoidal Pulse Width Modulation (SPWM) technique to generate the sinusoidal voltage required to drive the fan motor. Our experimental results show how Variable Voltage Variable Frequency (VVVF) is implemented at a low cost using our method for household fan speed control. The results can be applied to various VR applications to enhance the sense of immersion by providing users with realistic wind.

• Earthquakes and Structures
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• 제22권1호
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• pp.53-64
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• 2022

This study proposes an intelligent semi-active isolation system combining a variable-stiffness control device and ground motion characteristic prediction. To determine the optimal control parameter in real-time, a genetic algorithm (GA)-fuzzy control law was developed in this study. Data on various types of ground motions were collected, and the ground motion characteristics were quantified to derive a near-fault (NF) characteristic ratio by employing an on-site earthquake early warning system. On the basis of the peak ground acceleration (PGA) and the derived NF ratio, a fuzzy inference system (FIS) was developed. The control parameters were optimized using a GA. To support continuity under near-fault and far-field ground motions, the optimal control parameter was linked with the predicted PGA and NF ratio through the FIS. The GA-fuzzy law was then compared with other control laws to verify its effectiveness. The results revealed that the GA-fuzzy control law could reliably predict different ground motion characteristics for real-time control because of the high sensitivity of its control parameter to the ground motion characteristics. Even under near-fault and far-field ground motions, the GA-fuzzy control law outperformed the FPEEA control law in terms of controlling the isolation layer displacement and the superstructure acceleration.