• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1912-1921
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• 2003

This paper presents a global mode modeling of space structures and a control scheme from the practical point of view. Since the size of the satellite has become bigger and the accuracy of attitude control more strictly required, it is necessary to consider the structural flexibility of the spacecraft. Although it is well known that the finite element (FE) model can accurately model the flexibility of the satellite, there are associated problems : FE model has the system matrix with high order and does not provide any physical insights, and is available only after all structural features have been decided. Therefore, it is almost impossible to design attitude and orbit controller using FE model unless the structural features are in place. In order to deal with this problem, the control design scheme with the global mode (GM) model is suggested. This paper describes a flexible structure modeling and three-axis controller design process and demonstrates the adequate performance of the design with respect to the maneuverability by applying it to a large flexible spacecraft model.

• Journal of Korean Elementary Science Education
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• v.28 no.4
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• pp.507-518
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• 2009

The purpose of this study was to determine the effects of verbal analogy activities on science achievement and science attitude of elementary students. Students consolidated lessons by making short sentences with core words that a teacher gave for scaffolding instruction. Many researches about analogies have been conducted in science education. However, most of them considered analogy as learning tools, whereas this research considers analogy as a cognitive process. To see the effects of verbal analogy activities, two groups were selected from 6th grade elementary school students; one was an experimental group working with the student-generated verbal analogy and the other was a control group with teacher-centered and textbook-centered activities. Science achievement, scientific attitudes, attitudes toward science and retention were tested after the treated lessons.

• Journal of Korean Academy of Nursing
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• v.31 no.6
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• pp.1088-1097
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• 2001

This study was formed to propose a theoretical background trying to create a positive delivery experience by understanding college women's subjective accounts (their view and attitude) on delivery. Method: Q- methodology was used to appreciate the highly abstract concept in an objective manner, since delivery can be assessed differently with each experience. Result: There were three types of opinions about the delivery in college women. The first type (matured type) understood delivery to be a precious experience that enables women to gain the value of life through labor pain, and granted then more appreciation to their own mothers. The second type (will type) recognizes delivery as an option rather than an obligation for women. They think women chooses whether or not to experience the process, especially since delivery requires a great deal of responsibility. The third type (positive type) takes delivery as a valuable, worthwhile, and marvelous process that they wish to experience. They are not even afraid of giving birth multiple times. Conclusion: The study explains and allows us to understand college women's overall opinion and attitudes about delivery. Thus this study aids the seizure of an opportunity to build a theoretical base for delivery management.

• Journal of The Korean Association of Information Education
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• v.22 no.1
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• pp.123-130
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• 2018

The purpose of this study is to investigate the process in which children center students are interested in SW education through the change of perception of SW education. Since the students in the regional Community Child Center are different in grade and age, they have suggested curriculum and teaching-learning process for each level. As a result, the students' attitude and satisfaction with SW education increased and it was found that the education program for the underprivileged is desperately needed.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.75-87
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• 2012

The purpose of this study is to find out the effects of internet resource-based problem-based learning on the academic achievement in science and the attitude toward science of elementary school students. One experiment class and one control class of grade 6 students were selected to perform a prior investigation on the academic achievement in science and the attitude toward science, then the experiment class attended 4 weeks of lessons that was applied the internet resource-based problem-based learning, and the control class attended the traditional lessons based on the guidelines of teachers. After conducting lessons, a post investigation was performed for each class and the results were analyzed to produce the following conclusions. First, the internet resource-based problem-based learning could be seen to be effective in improving the students' academic achievements in science. The internet resource-based problem-based learning seemed to make students recognize the lesson details better and grasp well the questions given during lessons from the process of finding solutions among many informations and data on the internet. Second, the internet resource-based problem-based learning had a positive effect on all attitudes' areas toward science of students. It looked like that the internet resource-based problem-based learning taught the students to use the internet resources and gave them a friendly feeling, so the children could actively participate in class and had positive recognition on science. Third, from teacher observation and the result of the student recognition investigation, we could know that the students showed lots of interests in the internet resource-based problem-based learning, and they were able to understand the scientific theories in the process of solving problems that were relevant to real life, and thought science in a positive way.

• International Journal of Control, Automation, and Systems
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• v.4 no.6
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• pp.782-787
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• 2006

The role of Unmanned Aircraft Vehicles(UAVs) has been increasing significantly in both military and civilian operations. Many complex systems, such as UAVs, are difficult to model accurately because they exhibit nonlinearity and show variations with time. Therefore, the control system must address the issues of uncertainty, nonlinearity, and complexity. Hence, identification of the mathematical model is an important process in controller design. In this paper, attitude dynamics identification of UAV is investigated. Using the flight data, nonlinear state space model for attitude dynamics of UAV is derived and verified. Real time simulation results show that the model dynamics match experimental data.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.88-94
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• 2002

This paper describes attitude determination algorithm for the low earth orbit(LEO) spacecraft using stellar inertial sensors. The cascaded gyro/star tracker extended Kalman filter is constructed to fuse two sensor data. And then the smoothing of the measurement are proposed for an unreasonable jump of star tracker. The smoothing algorithm for the rejection of star tracker error jumps is designed by scalar adaptive filter. The proposed algorithms operate to process the measurement of gyro/star tracker Kalman filter, therefore, it is comparatively simple to apply these methods to other integration systems. Simulations to gyro/star tracker integrated system show that the proposed method is effective.

• Journal of Industrial Convergence
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• v.19 no.6
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• pp.145-153
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• 2021

This study empirically verified whether there is a dual mediating effect of individual optimistic bias and information security intention in the relationship between information security attitude and information security behavior of social welfare college students. The subjects were 295 college students majoring in social welfare. Spss Process macro was used for analysis. As a result. first there was a significant positive correlation between the variables. Second in the relationship between information security attitude and information security behavior, individual optimistic bias and information security intent each had a simple mediating effect. Third when an individual's optimistic bias and information security intent were simultaneously input, each had a simple mediating effect. Fourth there was a double mediating effect between individual optimistic bias and information security intent. This study provided basic data for the expansion of information security model and information security education of social welfare students.

• Journal of Information Technology Services
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• v.13 no.2
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• pp.35-53
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• 2014

Company Social Networks (CSN) has emerged as a commonly used marketing channel. One of the most important advantages in CSN is the user's voluntary behavior as a relational performance. We classified level of voluntary behavior, as 'consumption', 'active participation', and 'creative contribution' to comprehend different relational performance of CSN. Moreover, we proposed research model to compare positive attitude and negative attitude. This study aims to investigate 'the process of user's voluntary behavior in CSN' which is causal relationship between benefits of CSN, user's attitude and voluntary behavior. Empirical results with 175 valid questionnaire data revealed that CSN benefit factors played a significant role in trust and distrust. Based on these effects, trust and distrust have different influences as level of voluntary behavior, just as proposed. For practitioners, it is crucial finding that users are more active behavior based on strong trust.

• Asian Journal of Business Environment
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• v.14 no.1
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• pp.31-37
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• 2024

Purpose: The study aims to identify the factors contributing to the formation of entrepreneurial intentions among recent university graduates. The original value of this study lies in providing support and a better understanding of the entrepreneurial decision-making process of Vietnamese fresh graduates. Research design, data and methodology: The research methodology employs Exploratory Factor Analysis (EFA) with a sample size of 385 university graduates in Vietnam. Results: The results indicate that three key factors, including relational support, educational support, and attitude towards business, positively impact entrepreneurial intentions. Conclusions: The managerial implications are provided to promote entrepreneurial intention among recent university graduates.