• Research in Community and Public Health Nursing
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• v.26 no.3
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• pp.238-247
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• 2015

Purpose: This study was conducted to investigate the effects of a positive psychology improvement program on elders' depression and death anxiety. Methods: This was conducted as a quasi-experimental study with non-equivalent control group pretest-posttest design. The participants were community elders aged over 65 recruited by convenient sampling. A total of 94 elders (32 in the individual experimental group, 32 in the collective experimental group, and 30 in the control group) participated. Data were collected between April and September, 2012 and analyzed by using SPSS/WIN 21. Results: The individual and group approach experimental groups had significantly lower scores of depression than the control group after the treatment (F=7.50, p=.001). For death anxiety, however, only the individual experimental group had a significantly lower score compared to the control group (F=4.56, p=.013). Conclusion: These results indicate that the positive psychology improvement program was effective in decreasing depression and death anxiety in the elderly. Therefore, the program needs to be applied in a customized way fittingly to the characteristics of the elderly in community, and individually and/or collectively according to its purposes.

• Research in Community and Public Health Nursing
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• v.30 no.3
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• pp.257-270
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• 2019

Purpose: This study is designed as a non-equivalent, control group pre/post-test for identifying effectiveness of a workplace walking program using a fitness tracker including individual counseling and tailored text messaging. Methods: Seventy-nine employees from two large companies were allocated into an intervention group (n=39) and a control group (n=40). Participants were asked to wear a fitness tracker (Fitbit Charger HR) during 24-hour, 5-days per week, for 10 weeks. The intervention group was provided with daily walking steps measured by Fitbit, weekly counseling with a specifically designed workbook, and seven weekly text messaging, and the control group with the fitness tracker only. Results: At the week 10 measurement, there were significant differences between the intervention and control groups in physical activity self-efficacy (p<.001), physical activity behavior (p<.001), daily walking steps (p<.001), systolic blood pressure (p=.033), and wellness (p<.001). Conclusion: These results suggest that the workplace walking program using a fitness tracker including individual counseling and tailored text messaging is more effective for persons with 10,000 steps/day. Therefore, it is recommended to actively apply this workplace walking program to inactive employees for encouraging regular physical activities and improving their wellness.

• Journal of the Korean Home Economics Association
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• v.42 no.4
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• pp.99-118
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• 2004

This study examined different individual and environmental factors that affect children's game addiction tendency. As individual variables, game user' motivation, self-control, and self-esteem were included in the analysis. As family variables, communications with mothers, parental control of children's computer use and parental internet use were examined, as school variables, school adjustment and teacher's supervision of children's computer use, and as peer variables, peer group's attitude toward computer games were used. The sample consisted of 994 fifth and sixth grade children. Statistics and methods used for the data analysis were Cronbach's alpha, frequency, percentage, two way ANOVA, Pearson's correlation and Hierarchical Regression. Several major results were found from the analysis. First, boys were addicted more than girls. No difference was found in the addiction tendency between the 5th graders and the 6th graders. Second, game users' motivation, that is, their interest-amusement motive, avoidance motive and aggressive motive, had a positive correlation with their game addiction tendency. However, self-control and self-esteem had a negative correlation with children's game addiction tendency. Third, problematic communications with mothers and parental control of children's computer use had a positive correlation with children's game addiction tendency. Open communications with mothers had a negative correlation with children's game addiction tendency. Fourth, school adjusaent had a negative correlation with children's game addiction tendency. And peer group's attitude towards computer games had a positive correlation with children's game addiction tendency. Fifth, low self-control, peer group's attitude towards computer games, children's interest-amusement motive, avoidance motive, aggressive motive, school lesson adjustment, parental control of children's computer use and school nile adjustment were important predicting variables of boy's game addiction tendency. Avoidance motive, low self-control, interest-amusement motive, peer group's attitude towards computer games, and parental control of children's computer use were important predicting variables of girl's game addiction tendency.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1096-1103
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• 2014

This paper proposes a novel strategy for attenuating the output power fluctuation of the wind farm (WF) in a range of tens of seconds delivered to the grid, where the kinetic energy caused by the large inertia of the wind turbine systems is utilized. A control scheme of the two-level structure is applied to control the wind farm, which consists of a supervisory control of the wind farm and individual wind turbine controls. The supervisory control generates the output power reference of the wind farm, which is filtered out from the available power extracted from the wind by a low-pass filter (LPF). A lead-lag compensator is used for compensating for the phase delay of the output power reference compared with the available power. By this control strategy, when the reference power is lower than the maximum available power, some of individual wind turbines are operated in the storing mode of the kinetic energy by increasing the turbine speeds. Then, these individual wind turbines release the kinetic power by reducing the turbine speed, when the power command is higher than the available power. In addition, the pitch angle control systems of the wind turbines are also employed to limit the turbine speed not higher than the limitation value during the storing mode of kinetic energy. For coordinating the de-rated operation of the WT and the storing or releasing modes of the kinetic energy, the output power fluctuations are reduced by about 20%. The PSCAD/EMTDC simulations have been carried out for a 10-MW wind farm equipped with the permanent-magnet synchronous generator (PMSG) to verify the validity of the proposed method.

• ETRI Journal
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• v.22 no.4
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• pp.40-50
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• 2000

We apply a "sliding-window" Maximum Likelihood(ML) estimator to estimate traffic parameters On-Off source and develop a method for estimating stochastic predicted individual cell arrival rates. Based on these results, we propose a simple Connection Admission Control(CAC)scheme for delay sensitive services in broadband onboard packet switching satellite systems. The algorithms are motivated by the limited onboard satellite buffer, the large propagation delay, and low computational capabilities inherent in satellite communication systems. We develop an algorithm using the predicted individual cell loss ratio instead of using steady state cell loss ratios. We demonstrate the CAC benefits of this approach over using steady state cell loss ratios as well as predicted total cell loss ratios. We also derive the predictive saturation probability and the predictive cell loss ratio and use them to control the total number of connections. Predictive congestion control mechanisms allow a satellite network to operate in the optimum region of low delay and high throughput. This is different from the traditional reactive congestion control mechanism that allows the network to recover from the congested state. Numerical and simulation results obtained suggest that the proposed predictive scheme is a promising approach for real time CAC.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.26-33
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• 2010

A multi-MW wind turbine is a huge mechanical structure, of which the rotor diameter is more or less than 100 m. Rotor blades experience unsymmetric mechanical loads caused by the interaction of incoming wind with the tower and wind shear effect. These mechanical loads are transferred to the entire structure of the wind turbine and are known as the major reasons for shortening the life span of the wind turbine. Therefore, as the size of wind turbine gets bigger, the mitigation of mechanical loads becomes more important issue in wind turbine control system design. In this paper, a concept of an individual pitch control(IPC), which minimizes the mechanical loads of rotor blades, is introduced, and simulation results using IPC are discussed.

• Asia pacific journal of information systems
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• v.31 no.3
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• pp.257-276
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• 2021

This study investigates the factors that facilitate or hinder people to use mobile payment, especially drawing upon the theoretical perspectives on individual's privacy protection motivation and perceived market condition. Survey data (n = 200) were collected through a web-based platform and used to test a theoretical model. The results show that one's privacy protection power is formed by various individual and technological factors (i.e., perceived data exposure, self-efficacy, and response efficacy), and in turn it determines his/her intention to use mobile payment. Moreover, the relationship between privacy protection power and mobile payment use is conditional on the perceived market control by the service provider - with a perception of the high level of provider's market control, one uses mobile payment regardless of his/her privacy protection power, while under the low level of provider's market control, the decision depends on the degree of privacy protection power. The findings would help our understanding of why some people are more susceptible to mobile payment and others are not.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.649-660
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• 2021

Through analytical method based on S-76 model, the level of rotor hub vibration reduction was analyzed according to higher harmonic actuating by individual blade control. The higher harmonic actuating method for individual blades was divided into a method of generating an additional actuating force from the pitch-link in the rotating part and generating actuating force through the active trailing edge flap control of the blade. In the 100kts forward flight conditions, the hub load analysis was performed by changing the phase angle of 15 degree for the 2P/3P/4P/5P harmonic actuation for individual blades. Through the harmonic actuation results, the sensitivity of the rotor system according to the actuating conditions was analyzed, and the T-matrix representing the characteristics of the rotor system was derived based on this analysis result. And through this T-matrix, optimal higher harmonic actuating condition was derived to minimize hub vibration level for flight condition. In addition, the effect on the performance of the rotor system and the pitch-link load under minimum hub vibration condition, as well as the noise influence through the noise analysis were confirmed.

• Research in Community and Public Health Nursing
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• v.26 no.1
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• pp.1-10
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• 2015

Purpose: This study was conducted to investigate changes in cognitive functions, depression and life-satisfaction for elderly participants with mild cognitive impairments participating in an individual cognitive improvement program. Methods: A quasi-experimental with non-equivalent control group pretest-posttest design was implemented. The participants were senior citizens over 65 years of age who had been clinically diagnosed with mild cognitive impairments in G City and J Province (experimental group: 29, control group: 27). The experimental group participated in the individual cognitive improvement program based on Korean traditional tales and games for nine weeks. Results: After the intervention, only the participants in the experimental group reported significant improvement in K-MMSE (t=-2.5, p=.016), MoCA-K (t=-2.6, p=.008), depression (t=3.51, p=.001), and life satisfaction (t=-2.75, p=.008) when compared to those in the control group. Conclusion: These results indicated that the individual cognitive improvement program was effective in improving cognitive functions, depression, and life-satisfaction among the elderly with mild cognitive impairments. Therefore, the application of this individual cognitive improvement program developed in this study by visiting nurses may strengthen the cognitive functions of seniors with mild cognitive impairments.

• Convergence Security Journal
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• v.21 no.2
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• pp.37-46
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• 2021

Decentralized Identifier (DID) technology is a technology that uses blockchain technology to prove an individual's identity through information owned by the individual rather than through a central system. In this paper, we would like to present an access control system using decentralized identifier technology. The access control system using decentralized identifier technology (DID access control system) is a system that allows users to verify their identity from the DID blockchain server through their smartphone (mobile employee ID) and access when they are confirmed to be registered in the access control system. Through this, access control can be managed only by verifying identification with smartphones (mobile employee ID) and DID blockchain servers without having to store information to prove an individual's identity in the access control system.