• Journal of Educational Research in Mathematics
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• v.12 no.3
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• pp.313-329
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• 2002

The importance of professor's outline in a feedback instruction was examined through various documents and the way in which the evaluation was fulfilled in Korean educational environment and its reflection upon the evaluation result were investigated by means of research. Based upon the survey results in connection with the progress and basis of teachers' on the spot feedback mathematics instruction in schools, it was found that most of teachers who engaged in feedback mathematics instruction were going over the most frequently missed problems. I proposed that we should bring up the point at issue and grasp its tendency of a class and entire group's results by means of a relative comparative analysis method, and thereupon establish a fixed category and choose substantial feedback scholarship according to that category. From this basis, the sub-sequent research topics include the substantial feedback effects of the selected problems that should be given priority, a group analysed and classified by means of comparison of tendency as well as feedback outline depended on students' characteristic, and the determining factors of tendency(a condition of professors, a level of students, geographical difference(s), and gender difference(s), etc...).

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.1
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• pp.11-17
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• 2001

We consider the M/G/1 with Bernoulli feedback, where the served customers wait in the feedback queue for rework with probability p. It is important to decide the moment of dispatching in feedback systems because of the dispatching cost for rework. Up to date, researches have analyzed for the instantaneous-dispatching model or the case that dispatching epoch is determined by the state of feedback queue. In this paper we deal with a dispatching model whose dispatching epoch depends on main queue. We adopt supplementary variable method for our model and a numerical example is given for clarity.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.1
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• pp.29-44
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• 2013

This study suggests that as receiving feedback is moved back, the effectiveness of problem-solving increases. Utilizing data from innovation contests in which a number of problem solvers compete with each other, we answer questions such as whether the order of receiving first feedback affects problem-solving effectiveness and how problem-solving experience moderates the relationship between the first feedback order and problem-solving effectiveness. Empirical results based on data collected from Kaggle, an online platform for innovation contests, showed that the order that contest participants receive the first feedback increases problem-solving effectiveness. Furthermore, the more prior experience of contest participants accentuates the suggested relationship between the order of receiving the first feedback and problem-solving effectiveness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.852-857
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• 2008

A new adaptive neuro-control algorithm for a SISO strict-feedback nonlinear system is proposed. All the previous adaptive neural control algorithms for strict-feedback nonlinear systems are based on the backstepping scheme, which makes the control law and stability analysis very complicated. The main contribution of the proposed method is that it demonstrates that the state-feedback control of the strict-feedback system can be viewed as the output-feedback control problem of the system in the normal form. As a result, the proposed control algorithm is considerably simpler than the previous ones based on backstepping. Depending heavily on the universal approximation property of the neural network (NN), only one NN is employed to approximate the lumped uncertain system nonlinearity. The Lyapunov stability of the NN weights and filtered tracking error is guaranteed in the semi-global sense.

• Research in Mathematical Education
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• v.10 no.2 s.26
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• pp.115-124
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• 2006

In order to optimize a learning effect in mathematics, the results of the educational assessment must be effectively used by both teachers and students. The teacher using technology to provide students with performance feedback is becoming more prevalent in educational contexts worldwide but concern arises over the form of that feedback and the effects it has upon students' achievements. Also, feedback takes considerable time for teachers but their instructional time is limited. For these reasons, it is a significant matter how to select items effectively in order to give feedback to students after an assessment. In this study, we introduce the systematic selection method of feedback items using the regression analysis in order to provide effective feedback to students by teachers.

• ETRI Journal
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• v.36 no.6
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• pp.979-987
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• 2014

This paper describes new tactile feedback patterns and the effect of their input performance for a button GUI activated by a tap gesture on mobile touch devices. Based on an analysis of touch interaction and informal user tests, several tactile feedback patterns were designed. Using these patterns, three user experiments were performed to investigate appropriate tactile feedback patterns and their input performance during interaction with a touch button. The results showed that a tactile pattern responding to each touch and release gesture with a rapid response time and short falling time provides the feeling of physically clicking a button. The suggested tactile feedback pattern has a significantly positive effect on the number of typing errors and typing task completion time compared to the performance when no feedback is provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1319-1329
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• 2012

Globally stabilizing adaptive fuzzy state- and output-feedback controllers for the fully nonaffine pure-feedback nonlinear system are proposed in this paper. By reformulating the original pure-feedback system to a standard normal form with respect to newly defined state variables, the proposed controllers require no backstepping design procedures. Avoiding backstepping makes the controller structure and stability analysis to be considerably simplified. For the global stabilty of the clossed-loop system, the self-structuring fuzzy system whose memebership functions and fuzzy rules are automatically generated and tuned is adopted. The proposed controllers employ only one fuzzy logic system to approximate unknown nonlinear function, which highlights the simplicity of the proposed adaptive fuzzy controller. Moreover, the output-feedback controller of the considered system proposed in this paper have not been dealt with in any literature yet.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1134-1136
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• 1996

A necessary and suficient conditions is proposed for feedback linearizable SISO systems with unknown constant parameters. It is shown that the systems which satisfy the proposed conditions can be transformed into a controllable linear system with unknown parameter and it can be stabilized using the nonlinear feedback linearizing controller. We also present the analysis and implementation of a nonlinear feedback linearizing control for an Electro-Magnetic Suspension (EMS) system. We show that an EMS system is nonlinear feedback linearizable and satisfies the proposed conditions, and hence that the proposed nonlinear feedback controller for an EMS system is robust against mass parameter perturbation and force disturbance.

• Educational Technology International
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• v.24 no.2
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• pp.237-262
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• 2023

This study focuses on the instructor's role in student-centered learning and aims to test the effects and moderating role of instructor feedback on perceived loafing in team project-based learning. A conditional effect model including team efficacy, perceived loafing, instructor feedback, and team performance was proposed. Data were collected from students who registered for team project-based learning courses at a university in South Korea. A total of 420 cases were subjected to moderated mediation analysis. The results demonstrated that instructor feedback was negatively related to perceived loafing and moderated the relationship between team efficacy and perceived loafing. Furthermore, instructor feedback moderated the relationship between perceived loafing and team performance. In particular, even when perceived loafing was high, students who received frequent instructor feedback were found to significantly reduce the damage to team performance. Based on these findings, the importance of instructors' facilitation in team project-based learning is discussed.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.122-124
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• 1998

The inverter circuit of brushless do moter(BLDCM) needs feedback diodes to protect the switching element from counterelectromotive force. In this paper, we describe the computational method of characteristic analysis of BLDCM with feedback diodes by using the FEM.