• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.205-214
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• 2016

Dramatic transformation in education has taken place and Internet Technologies have played a key role. Especially SNS has been considered as an effective educational tool because of its exceptional features such as discussion on course topics, feedback from peers and group collaboration. The purpose of this paper is to investigate factors affecting the attitude, intention to continuous use of SNS and performance in college education comparing between experienced learner and non-experienced learner. Self-efficacy on media usage, educational expectancy, subjective norm, habit, and enjoyment were identified as affecting factors based on prior researches. The results shows that all factors are significantly related to the learner's attitude on the use of SNS in college education. Experienced learner's attitude on educational use of SNS in college was found to be significantly related to the intention to continuous use and performance. This study can provide a guideline of effective strategy for SNS utilization in college education.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.5
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• pp.373-381
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• 2020

Quadrotor is simple to model because of the symmetric structure but it has the disadvantage of being relatively sensitive to the external disturbance and system uncertainty. The PID technique applied for the attitude control of quadrotor has been applied comprehensively, but it has a disadvantage that is hard to precise control in the nonlinear system. In this work, a quadrotor attitude control law using the super twisting algorithm is studied, which has robust characteristics against disturbance and system uncertainty. To evaluate the attitude performance by the proposed technique, simulation studies and actual flight tests are carried out, and compared with the conventional PID controller.

• Journal of Biosystems Engineering
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• v.18 no.3
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• pp.199-208
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• 1993

This study was attempted to develop the eletronic-hydraulic hitch system for controlling the attitude of tractor implements and to investigate control performance of the system through experiments. Main components of the system developed in this study were reference inputs panel, inclination angle detecter, electronic controller consisted of IBM-AT PC and interfaces, electro-hydraulic directional valves and other hydraulic components and three-point hitch linkage. Experiments were carried out to investigate the response of the system to the step and sine inputs. The effects of hydraulic flow rate and dead band on control performance were analized. Attitude of the implement was controlled within 2.4-5.1 degrees to the setting attitude when the hydraulic flow rate was in the range of $0.25-1.5{\ell}/min$. And implement was controlled without rapid amplitude attenuation and phase angle change in the frequency range of 0.02-0.2Hz when the hydraulic flow rate was in the range of $0.25-1.5{\ell}/min$. Control performance of the system can be expected to be improved if the inclination angle detecter show rapid and stable output as the implement moves.

• Korean Journal of Adult Nursing
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• v.28 no.4
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• pp.388-398
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• 2016

Purpose: The purposes of this study were to identify nurses' empathy, attitude and pain management for patients with dementia and the factors associated with their performance of pain management. Methods: The study design was a cross-sectional survey. The participants in the study were 114 nurses working at 12 geriatric hospitals. This study utilized the Interpersonal Reactivity Index (IRI), which measures four empathy factors. Nurses' attitudes toward pain and performance of pain management, and general and pain related characteristics were measured by self-administered questionnaires. Results: Barriers to pain management for patients with dementia were absence of guidelines, prejudice of pain in dementia, and lack of time and knowledge deficit. There was a significant positive correlation between empathic concern and attitudes, perspective-taking of empathy and pain management. There was also a correlation between empathy and pain management. Stepwise linear regression analysis indicated that the significant factors affecting the performance of pain management included perspective-taking of empathy, use of pain management in dementia guideline and attitudes toward pain. These factors explained 24.0% of variance. Conclusion: The findings from this study suggest that empathy and positive attitude are the important provider attributes which needs to be enhanced by educational programs. It is also necessary to develop and disseminate guidelines for a dementia specific pain management.

• Korean Journal of Human Ecology
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• v.15 no.5
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• pp.761-773
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• 2006

The purpose of this study was to explore the consumers' attitude and expectation-satisfaction on well-being products, Consumers' expectation, performance and disconfirmation scales were composed 7 items of 5-likert scales. Consumers' Satisfaction on well-being products was measured with one-item-measurement scale, The consumers' well-being attitudes were composed 4 dimensions such as (1)consuming the well-being products, (2)pursuit of mental well-being, (3)criticism about commercial fashion, (4) pursuit of harmony with natural life. The results were as follows: 1. The well-being attitudes were contrast with a positive attitude and negative attitude, Especially, criticism about commercial fashion was highly remarked. 2. There were statistic differences in the consumers' expectation and performance on well-being products, The Expectation was higher than the performance. It means that consumers' high expectation on the well-being products will bring about the lower satisfaction or dissatisfaction. 3. Consumers' Satisfaction on the well-being products was statistically different among groups by the well-being attitudes.

• Journal of Space Technology and Applications
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• v.4 no.1
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• pp.12-26
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• 2024

Attitude control of a satellite is very important to ensure proper for mission performance. Satellites launched in the past had simple missions. However, recently, with the advancement of technology, the tasks to be performed have become more complex. One example relies on a new technology that allows satellites quickly alter their attitude while orbiting in space. Currently, one of the most widely used technologies for satellite attitude control is the reaction wheel. However, the amount of torque generated by reaction wheels is too low to facilitate quick maneuvers by the satellite. One way to overcome this is to implement posture control logic using a control moment gyroscope (CMG). Various types of CMGs have been applied to space systems, and CMGs are currently mounted on large-scale satellites. However, although technological advancements have continued, the market for CMGs applicable to, small satellites remains in its early stages. An ultra-small CMG was developed for use with small satellites weighing less than 200 kg. The ultra-small CMG measured its target performance outcomes using a precision torque-measuring device. The target performance of the CMG, at 800 mNm, was set through an analysis. The final torque of the CMG produced through the design after the analysis was 821mNm, meaning that a target tolerance level of 10% was achieved.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.1 s.149
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• pp.146-156
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• 2006

The purpose of this study is to investigate the factors that influence consumers' adoption of performance infants' wear made of functional textiles. Based on Innovation Diffusion Model, product attributes, consumer traits, and communication characteristics were considered. A survey was carried out with a convenience sample of 241 housewives who have infants under 4 year-old, living in the Seoul metropolitan area. To analyze the data, SPSS 10.0 was used employing ANOVA, Duncan's post-hoc comparison, $X^2$, and f-test. The participants were classified into 4 groups based on their levels of adoption of performance infants' wear: No-Cognition, Negative Attitude, Positive Attitude, and Purchasing groups. There were significant differences among the four groups in terms of their perception of product attributes, communication characteristics, and personal traits. In terms of product attributes, the Positive Attitude group and Purchasing group showed higher perception of relative advantage, compatibility, trialability and observability than other groups. These groups were also high in terms of their tendency of actively seeking for additional product information, and particularly relied on the information from experts on TV or the Internet, personal experience posted on the Internet, or their own experience. Those who were in professional, well-educated and high income brackets were more likely to be Purchasing group than Positive Attitude group, which means once the positive attitude was formed they are likely to purchase the product.

• Journal of Information Technology Applications and Management
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• v.26 no.2
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• pp.13-26
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• 2019

The purpose of this study is to examine the effect of each of the two technology acceptance factors(employees' attitude toward smart factory technology, and ease of smart factory technology use) on the introduction level of each of the three smart factory technologies (manufacturing big data technology, automation technology, and supply chain integration technology), and in turn, the effect of each of the three smart factory technologies on manufacturing performance. This study employed PLS statistics software package to empirically validate a structural equation model with survey data from 100 domestic small-and medium-sized manufacturing firms (SMMFs). The analysis results revealed the followings. First, it is founded that employees' attitude toward smart factory technology influenced all of the three smart factory technology introduction levels in a positive manner. In particular, SMMFs of which employees had more favorable attitude toward smart factory technology tended to increase introduction levels of both automation technology and supply chain integration technology more than in the case of manufacturing big data technology. Second, ease of smart factory technology use also had a positive impact on each of the three smart factory technology introduction levels, respectively. A noteworthy finding is this : SMMFs which perceived smart factory technology as easier to use would like to elevate the introduction level of manufacturing big data technology more than in the cases of either automation technology or supply chain integration technology. Third, smart factory technologies such as automation technology and supply chain integration technology had affirmative impacts on manufacturing performance of SMMFs. These results shed some valuable insights on the introduction of smart factory technology : The success of smart factory heavily depends on organization-and people-related factors such as employees' attitude toward smart factory technology and employees' perceived ease of smart factory technology use.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.4
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• pp.468-473
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• 2014

This paper describes the in-flight alignment of SDINS (Strapdown Inertial Navigation Systems) using an EKF (Extended Kalman Filter) and a UKF (Unscented Kalam Filter), which allow large initial attitude error uncertainty. Regardless of the inertial sensors, there are nonlinear error dynamics of SDINS in cases of large initial attitude errors. A UKF that is one of the nonlinear filtering approaches for IFA (In-Flight Alignment) are used to estimate the attitude errors. Even though the EKF linearized model makes velocity errors when predicting incorrectly in case of large attitude errors, a UKF can represent correctly the velocity errors variations of attitude errors with nonlinear attitude error components. Simulation results and analyses show that a UKF works well to handle large initial attitude errors of SDINS and the alignment error attitude estimation performance are quite improved.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.4
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• pp.303-312
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• 2010

This paper introduces the upper stage attitude control system of KSLV-I, which is the first space launch vehicle in Korea. The KSLV-I upper stage attitude control system consists of two electro-hydraulic actuators and a reaction control system using cold nitrogen gas. A proportional, derivative, and integral controller is designed for the electro-hydraulic thrust vectoring system, and Schmidt trigger ON/OFF controllers are designed for the reaction control system. Each attitude controller is designed to have enough stability margins. The stability and performance of KSLV-I upper stage attitude control system is verified via hardware in the loop tests. Hardware in the loop tests are accomplished for perturbed flight conditions as well as nominal flight condition. The test results show that the attitude control loop of KSLV-I upper stage is very stable and the attitude controllers perform well for all flight conditions. Attitude controllers designed in this paper have been successfully applied to the first flight of KSLV-I on August 25, 2009. The flight test results show that all attitude controllers of the KSLV-I upper stage performed well and satisfied the accuracy specifications even during abnormal flight conditions.