• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.39 no.10
• /
• pp.1098-1107
• /
• 1990

Decentralized iterative learning control methods are presented for a class of large scale interconnected linear dynamic systems, in which iterative learning controller in each subsystem operates on its local subsystem exclusively with no exchange of information between subsystems. Suffcient conditions for convergence of the algorithms are given and numerical examples are illustrated to show the validity of the algorithms. In particular, the algorithms are useful for the systems having large uncertainty of inter-connected terms.

• Journal of the Korean Statistical Society
• /
• v.24 no.2
• /
• pp.361-373
• /
• 1995

Three remarks are offered, pertaining to classes of estimators Pitman-dominating a given estimator. The first remark concerns incorporating general loss in the construction of such classes. The second remark concerns Pitman domination comparisons amongst the members of such classes. The third remark concerns construction of such a class in the location-scale case.

• Journal of the Korean Statistical Society
• /
• v.9 no.2
• /
• pp.181-193
• /
• 1980

A class of nonparametric estimators of the ratio of scale parameters is proposed. The estimators are based on the distribution-free rank-like test suggested by Fligner and Killeen (1976). An explicit form of the estimator is the median of the ratios of absolute deviations from the combined sample median. A small-sample Monte Carlo study shows that the proposed estimator is more efficient than the Bhattacharyya (1977) estimator. The proposed estimator is is reasonably insensitive to small failures in the assumption of equal medians. A modified estimator is also considered when the meidans are unequal.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.97.2-97.2
• /
• 2014

In this paper, we study the stability and dynamics of a magnetic field producing the M6.6 class solar flare taking place in NOAA active region (AR) 11158 on 2011 February 13th. Toriumi et. al. (2013) recently suggest that a fine scale magnetic structure on the photosphere gives a major possibility to produce the M6.6 class flare. On the other hand, they don't discuss the torus instability as a plausible mechanism even though Zhao et. al. (2014) and Janvier et. al. (2014) suspect it as the trigger mechanism of X2.2 class flare taking place later in the same AR. We are the first to investigate the stability of a nonlinear force-free field (NLFFF) prior to the M6.6 class flare against the torus instability by using analytical and numerical approaches. Consequently, we found that our NLFFF is quite stable against small perturbation. This result supports that the flare is triggered by the photospheric motion suggested by Toriumi et. al. (2013). We further perform another MHD simulation with an anomalous resistivity using the NLFFF as an initial condition. As a result, we found the eruption of strongly twisted lines. We compare our simulation results with observations and discuss relevant dynamics in detail.

• Journal of Korean society of Dental Hygiene
• /
• v.15 no.6
• /
• pp.1091-1097
• /
• 2015

Objectives: The purpose of this study was to examine the relationship between educational satisfaction and learning participation of dental hygiene students. Method: A self-reported questionnaire was completed by 344 dental hygiene students in Gyeonggido, Chungcheongdo, and Gyeongsangdo from June 2 to 24, 2014, The questionnaire consisted of general characteristics of the subjects(3 items), choice reason of dental hygiene(7 items), educational satisfaction(22 items), and learning participation(11 items). The educational satisfaction and learning participation were assessed by Likert 5 points scale. Data were analyzed by a statistical package SPSS WIN 18.0. Results: Educational satisfaction included educational environments, teaching, educational content and educational effect. Learning participation included class flow, class participation and class readiness. Gyeongsangdo students tended to have higher score than other areas. The educational effect and teaching effect had more influence on learning participation. Conclusion: To improve the better dental hygiene education, it is important to prepare the effective educational methods and find out the influencing factors for class immersion.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.3
• /
• pp.65-71
• /
• 2011

The concrete mixer truck which is in charge of raw materials in civil engineering construction of the concrete loading, transport, placement, is used $6m^3$, $7m^3$ class in domestic(Korea). But in the case of the international construction fields are utilized $9m^3$ or above class because of the large-scale engineering and construction circumstances. In this paper, to develop a large $9m^3$ class mixer drum and the mixer drum in order to complement the technical and discharge that is responsible for stirring the blades by applying optimal design through implementation of the optimal shape of the concrete in the drum maintenance and placement of high-quality effects on increasing discharge such as advanced conventional drum mixer is to secure and differentiated technology. Large, heavy weight in development and uphold the drum mixer vehicle sub-frame is required to settle the design of the existing class mixer drum frames per $6m^3$ changed to account for changes in slope and length using CATIA V5 3D modeling work was performed.

• The Journal of the Korea Contents Association
• /
• v.11 no.8
• /
• pp.499-511
• /
• 2011

The purpose of this paper was to investigate differences in middle school student's after school satisfaction according to the type and the degree of flow of after school. For the purpose of this paper, a survey was conducted including a questionnaire consisting of a general characteristic of the study object, a general characteristic of the after school class, learning-flow scale, and after school satisfaction scale. The subjects were 382 students who were selected at random from middle school students. Cronbach' ${\alpha}$ and MANOVA were employed for data analysis. The results were as follows: First, the students with special-ability aptitude class were more satisfied for after school instructors than the students with subject class. Second, the students with the degree of high learning-flow showed higher satisfaction in after school class curriculum, instructors, and educational facility than the degree of low learning-flow students. Third, among the students who were high in learning-flow, the students with special-ability aptitude class were more satisfied with after-school class curriculum and educational facility compared to the students with subject class.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.21 no.1
• /
• pp.1-17
• /
• 1996

There have been considerable researches for solving large-scale separable convex optimization ptoblems. In this paper we present a method for large-scale nonseparable smooth convex optimization problems with block-angular linear constraints. One of them is occurred in reconfiguration of the virtual path network which finds the routing path and assigns the bandwidth of the path for each traffic class in ATM (Asynchronous Transfer Mode) network [1]. The solution is approximated by solving a sequence of the block-angular structured separable quadratic programming problems. Bundle-based decomposition method [10, 11, 12]is applied to each large-scale separable quadratic programming problem. We implement the method and present some computational experiences.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.11
• /
• pp.503-509
• /
• 2002

In this paper, the robust non-fragile guaranteed cost control problem is studied for a class of linear large-scale systems with uncertainties and a given quadratic cost functions. The uncertainty in the system is assumed to be norm-bounded and time-varying. Also, the state-feedback gains for subsystems of the large-scale system are assumed to have norm-bounded controller gain variations. The problem is to design a state feedback control laws such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound for all admissible uncertainties and controller gain variations. Sufficient conditions for the existence of such controllers are derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. A parameterized characterization of the robust non-fragile guaranteed cost controllers is given in terms of the feasible solutions to a certain LMI. A numerical example is given to illustrate the proposed method.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.6 no.2
• /
• pp.17-23
• /
• 2006

The purpose of this study was to investigate how student felt the strengths and shortness of presentation methods for formation of interior spaces. For this study, the process of the interior architecture design class was divided into three stages: the programming. the design development, and the design completion. In the design development stage, students used presentation methods: hand sketch, scale model, computer modeling, and virtual realty. The strengths of hand sketch was that quick expression. Models provided three-dimensional feelings. Computer modelling provide realistic color and texture. Virtual reality provided three-dimensional immersion and real scale. It is effective that students collect brain storm images using quick hand sketch in the beginning of design development stage. After that, they compose interior spaces in study models with small scale. Watching the models, they design details of spaces by using hand sketch and computer modelling. Using virtual reality, they can check the scale and circulation. Finally, they complete computer modelling by texture mapping and check the final design in virtual reality.