• Air Cleaning Technology
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• v.9 no.2 s.33
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• pp.86-96
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• 1996

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.109-124
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• 1994

The present study was conducted to elucidate the relationship between parent's verbal control modes and children's social competency. Two questionanires were developed by the authors for this study. The questionnaire for measuring parent's verbal control modes was composed of 84 and 87 items for mother and father, respectively, which assesses three types of verbal control modes; imperative control position-oriented control and person-oriented control. The questionnaire for measuring children's social competency perceived by mothers was composed of 27 items, which assesses four areas of social competency; initiative sociability responsibility and self-disclosure. the subjects of this study were 436 mothers and their children of fifth and sixth grade in elementary schools located in Seoul. The results of this study were as follows: 1) Parents control their children mostly by position-oriented mode and least by imperative mode. 2) There were significant correlations between father's verbal control mode and children's social competency. children's social competency was related positively to the person-oriented and position-oriented modes but negatively to the imperative mode. The best variables explaining boy's social competency were father's imperative and position-oriented modes whereas that for girl's was position oriented mode. 3) Mother's verbal control mode was not significant in explaining children's social competency. 4) The negative impact of father's imperative mode in combination with the mother's person-oriented mode on the children's social competency was greater than other combinations of father's and mother's verbal control modes.

• Journal of Korean Association for Spatial Structures
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• v.13 no.2
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• pp.37-45
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• 2013

Reduction of microvibration is regarded as important in high-technology facilities with high precision equipments. In this paper, smart control technology is used to improve the microvibration control performance. Mr damper is used to make a smart base isolation system amd fuzzy logic control algorithm is employed to appropriately control the MR damper. In order to develop optimal fuzzy control algorithm, a multi-objective genetic algorithm is used in this study. As an excitation, a train-induced ground acceleration is used for time history analysis and three-story example building structure is employed. Microvibration control performance of passive and smart base isolation systems have been investigated in this study. Numerical simulation results show that the multi-objective genetic algorithm can provide optimal fuzzy logic controllers for smart base isolation system and the smart control system can effectively reduce microvibration of a high-technology facility subjected to train-induced excitation.

• Journal of the Korean Home Economics Association
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• v.35 no.3
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• pp.231-243
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• 1997

The purpose of this study was to investigate answer the following research questions. (1) What is the trend of Children's locus of control, children's social competency, and children's prosocial behaviors? (2) Is there any relationship between children's locus of control and children's social competency, between children's locus of control and children's prosocial behavior, between children's social competency and children's prosocial behavior? (3) Is children's prosocial behavior influenced by the locus of control and by the social competency? The subjects of this study were 99 children atending the nursery school in Pusan. For the measurement of children's locus of control, the Stanford Preschool Internal-External Scale was used. As a measure of social competency. Iowa Social Competency was used. Children's prosocial behavior was measured by the amount of candies to share with playmates. The findings of this study were as follows: (1) The mean scores of children's locus of control, children's social competency, and children's prosocial behavior were low. (2) There significant correlation between children's locus of control and social competency, between children's locus of control and prosocial behavior. (3) Children's locus of control was an important predictor variable influencing children's prosocial behavior.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.15-25
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• 2020

This paper presents a longitudinal control algorithm for ensuring takeover time of autonomous vehicle using V2V communication. In the autonomous driving of more than level 3, autonomous systems should control the vehicles by itself partially. However if the driver's intervention is required for functional safety, the driver should take over the control reasonably. Autonomous driving system has to be designed so that drivers can take over the control from autonomous vehicle reasonably for driving safety. In this study, control algorithm considering takeover time has been developed based on computation method of takeover time. Takeover time is analysed by conditions of longitudinal velocity of preceding vehicle in time-velocity plane. In addition, desired clearance is derived based on takeover time. The performance evaluation of the proposed algorithm in this study was conducted using 3D vehicle model with actual driving data in Matlab/Simulink environment. The results of the performance evaluation show that the longitudinal control algorithm can control while securing takeover time reasonably.

• Journal of Korean Association for Spatial Structures
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• v.21 no.2
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• pp.41-48
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• 2021

A smart tuned mass damper (TMD) is widely studied for seismic response reduction of various structures. Control algorithm is the most important factor for control performance of a smart TMD. This study used a Deep Deterministic Policy Gradient (DDPG) among reinforcement learning techniques to develop a control algorithm for a smart TMD. A magnetorheological (MR) damper was used to make the smart TMD. A single mass model with the smart TMD was employed to make a reinforcement learning environment. Time history analysis simulations of the example structure subject to artificial seismic load were performed in the reinforcement learning process. Critic of policy network and actor of value network for DDPG agent were constructed. The action of DDPG agent was selected as the command voltage sent to the MR damper. Reward for the DDPG action was calculated by using displacement and velocity responses of the main mass. Groundhook control algorithm was used as a comparative control algorithm. After 10,000 episode training of the DDPG agent model with proper hyper-parameters, the semi-active control algorithm for control of seismic responses of the example structure with the smart TMD was developed. The simulation results presented that the developed DDPG model can provide effective control algorithms for smart TMD for reduction of seismic responses.

• Journal of Korean Association for Spatial Structures
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• v.21 no.1
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• pp.79-86
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• 2021

Control performance of a smart tuned mass damper (TMD) mainly depends on control algorithms. A lot of control strategies have been proposed for semi-active control devices. Recently, machine learning begins to be applied to development of vibration control algorithm. In this study, a reinforcement learning among machine learning techniques was employed to develop a semi-active control algorithm for a smart TMD. The smart TMD was composed of magnetorheological damper in this study. For this purpose, an 11-story building structure with a smart TMD was selected to construct a reinforcement learning environment. A time history analysis of the example structure subject to earthquake excitation was conducted in the reinforcement learning procedure. Deep Q-network (DQN) among various reinforcement learning algorithms was used to make a learning agent. The command voltage sent to the MR damper is determined by the action produced by the DQN. Parametric studies on hyper-parameters of DQN were performed by numerical simulations. After appropriate training iteration of the DQN model with proper hyper-parameters, the DQN model for control of seismic responses of the example structure with smart TMD was developed. The developed DQN model can effectively control smart TMD to reduce seismic responses of the example structure.

• The Journal of Industrial Distribution & Business
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• v.10 no.12
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• pp.35-42
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• 2019

Purpose : This study examines The impact of human resource investment in internal control on stock price crash risk. Effective internal control ensures that information provided is complete and accurate, financial statements are reliable. By overseeing management, internal control systems can reduce agency costs between management and outside parties. In Korea, firms have to disclose information about internal control systems. The working experience of human resources in internal control systems is also provided for interested parties. If a firm hires more experienced internal control personnel, it can better facilitate the disclosure of information. Prior studies reported that information asymmetry between managers and investors increases future stock price crash risk. Therefore, the longer working experience internal control personnel have, the lower probability stock crashes have. Research design, data and methodology : This study analyzed the association between the working experience of internal control personnel and crash risk using regression analysis on KOSPI listed companies for fiscal years 2016 through 2017. The sample consists of 1,034 firm-years of non-financial firms whose fiscal year end on December 31. Career spanning data of internal control personnel was collected from internal control reports. The professionalism(IC_EXP) was measured as the logarithm of the average working experience of internal control personnel in months. Negative conditional skewness(NSKEW) and down-to-up volatility (DUVOL) are used to measure firm-specific crash risk. Both measures are based on firm-specific weekly returns derived from the expanded market model. Results : We find that work experience in internal control environment is negatively related to stock price crashes. Specifically, skewness(NSKEW) and volatility (DUVOL) are reduced when firms have longer tenure of human resources in internal control division. The results imply that firms with experienced internal control personnel are less likely to experience stock price crashes. Conclusions : Stock price crashes occur when investors realize that stock prices have been inflated due to information asymmetry. There is a learning effect when internal control processes are done repetitively. Thus, firms with more experienced internal control personnel could manage their internal control more effectively. The results of this study suggest that firms could decrease information asymmetry by investing in human resources for their internal control system.

• Journal of Korean Association for Spatial Structures
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• v.16 no.3
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• pp.79-88
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• 2016

An outrigger damper system has been proposed to reduce dynamic responses of tall buildings. In previous studies, an outrigger damper system was optimally designed to decrease a wind-induced or earthquake-induced dynamic response. When an outrigger damper system is optimally designed for wind excitation, its control performance for seismic excitation deteriorates. Therefore, a smart outrigger damper system is proposed in this study to make a control system that can simultaneously reduce both wind and seismic responses. A smart outrigger system is made up of MR (Magnetorheological) dampers. A fuzzy logic control algorithm (FLC) was used to generate command voltages sent for smart outrigger damper system and the FLC was optimized by genetic algorithm. This study shows that the smart outrigger system can provide good control performance for reduction of both wind and earthquake responses compared to the general outrigger system.

• Journal of the Korean Home Economics Association
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• v.37 no.4
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• pp.85-95
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• 1999

This study was to investigate the following research questions. (1) Is there any gender difference in the mother's verbal control and the child's peer relation\ulcorner (2) Is there any relationship between the mother's verbal control and the child's peer relation\ulcorner (3) Is the child's peer-relation influenced by the mother's verbal control\ulcorner The subjects of this study were 157 boys and 144 girls attending elementary schools in Susan. Lee, Kyung-Hee's questionnaires(1993) on mother's verbal control modes and Lee, Ju-Lie's questionnaires(1994) on child's peer relation were used. The results were as follows: 1) The mother's imperative mode for boys differed significantly from that for girls. Boys perceived mother's verbal control mode as more imperative. 2) There were significantly correlations between mother's position- oriented mode and boy's peer relation, between mother's person-oriented mode and boy's peer relation, and between mother's position-oriented mode and girl's peer relation. 3) The mother's position-oriented mode and the mother's person-oriented mode were the predictor variables influencing on child's peer relation.