• Hwankyungkyoyuk
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• v.19 no.1 s.29
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• pp.14-29
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• 2006

The purpose of this study was to test effect of STS instruction using the subject matter of marine life on middle school students' perception of ocean. The objects of 156 students were sampled from the 1st grade of a middle school and were divided into an experimental group and a control group. 79 students of the control group were treated with traditional instruction, while 77 students of the experimental group were treated with STS instruction materials. All of the students took test of perception of ocean before and after the instructions. The perception of ocean was divided into four categories; value of sea, development of marine resources, research and conservation of sea, and perception of sea-related vocation. The results of the pretest and the posttest indicated that the perception of ocean of the experimental group was statistically significantly higher than that of the control group. Specially in categories of the value of sea and the research and conservation of sea, the scores of the experimental group were significantly higher than those of the control group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.1-14
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• 2014

This study has found out appropriate scopes of correlated color temperature and illuminance value with regard to general diffused lighting and work in the kitchen. It also has presented appropriate photometric quantity control speed for behavioral change with the following results. 1)For general diffused lighting, the appropriate photometric quantity has turned out to be 4,000 to 4,500K in color temperature and illuminance value of 300 to 400lx. And 300lx at 4,500K has proven to be the most comfortable, behavior-appropriate, and preferred pair. 2)As far as appropriate photometric quantity for work is concerned, color temperature of 4,000 to 5,000K and illuminance value of 600 to 800lx are appropriate, while 700lx at 4,500 to 5,000K are the most comfortable, behavior-appropriate, and preferred set. 3)As for appropriate photometric quantity control speed in behavioral change, 3 to 5 seconds has proven the most comfortable, appropriate, and preferred for behavioral change from entry to general areas and 1 to 3 seconds for change from general to work.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.599-602
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• 2004

In this paper, an automatic setting method of control parameters for robot scorer is proposed. First we acquisited some local image lesions including robots and ball patch, and sampled the regions to RCB value. Edge operator is applied to get magnitude of gradient at each pixel. Some effective patch regions can be detected by magnitude of gradient, and YUV value at each pixel in patch lesions can be obtained. We can determine control parameters of robot soccer using luminance component of YUV. The proposed method is applied to robot soccer image to detect initial patch value and get control parameters adaptively in light variation.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.57-68
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• 1995

A general procedure for the numerical solution of coupled, nonlinear, differential two-point boundary-value problems, solutions of which are crucial to the controller design, has been developed and demonstrated. A fixed-end-points, free-terminal-time, optimal-control problem, which is derived from Pontryagin's Maximum Principle, is solved by an extension of Davidenko's method, a differential form of Newton's method, for algebraic root finding. By a discretization process like finite differences, the differential equations are converted to a nonlinear algebraic system. Davidenko's method reconverts this into a pseudo-time-dependent set of implicitly coupled ODEs suitable for solution by modern, high-performance solvers. Another important advantage of Davidenko's method related to the time-optimal problem is that the terminal time can be computed by treating this unkown as an additional variable and sup- plying the Hamiltonian at the terminal time as an additional equation. Davidenko's method uas used to produce optimal trajectories of a single-degree-of-freedom problem. This numerical method provides switching times for open-loop control, minimized terminal time and optimal input torque sequences. This numerical technique could easily be adapted to the multi-point boundary-value problems.

• Asia-Pacific Journal of Business
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• v.14 no.4
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• pp.129-150
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• 2023

Purpose - This study is based on the Theory of Planned Behavior and aims to explore the decision-making mechanisms of consumers participating in value co-creation activities within virtual brand communities. Methodology - The research involved a comprehensive survey of 405 participants from various virtual brand communities. Structural Equation Modeling (SEM) was used for data analysis, applying SPSS and AMOS to test the hypotheses. The study focused on community rules and regulations, community experience and community trust. Results - The research found that community rules and regulations significantly impact subjective norms and perceived behavioral control, but not directly influence consumer attitudes. Community experience positively affected consumer attitudes, subjective norms and perceived behavioral control. Community trust was found to positively influence these aspects of consumer decision-making. However, a gap was identified in the direct influence of perceived behavioral control on actual consumer behavior. Implications - The findings of this study contribute to a more comprehensive understanding of factors affecting consumer behavior in virtual brand communities. It underscores the necessity for community managers to develop strategies that consider these internal decision-making mechanisms, facilitating more effective community engagement. The study also identifies a potential area for future research in the direct influence of perceived behavioral control on actual consumer behavior.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.661-663
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• 2016

Corruption occurs in the process of processing image signal and the corruption changes the pixel value within the image to damage the original information. AWGN(additive white Gaussian noise) is a representative example. For filters to remove AWGN, there are filters such as MF(mean filter), WF(wiener filter), and AWMF(adaptive weighted mean filter). However images processed through standard previous filters lock preservation characteristics in edge areas. Therefore, threshold value is applied for processing on the standard deviation of the local mask in this study and if the standard deviation is smaller than the threshold value, it is not filtered and if the value is bigger than the threshold value, the study suggested an algorithm that processes using weighted value utilizing standard deviation.

• Transactions on Control, Automation and Systems Engineering
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• v.1 no.1
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• pp.32-43
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• 1999

Adaptive robust control scheme is introduced for flexible joint manipulator with nonlinearities and uncertainties. The system does not satisfy the matching condition due to insufficient actuators for each node. The control only relies on the assumption that the bound of uncertainty exists. Thus, the bounded value does not need to be known a prior. The control utilizes the update law by estimating the bound of the uncertainties. The control scheme uses the backstepping method and constructs a state transformation. Also, stability analysis is done for both transformed system and original system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.356-356
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• 2000

For irregular nonlinear systems, switching controlk form is proposed recently. This control law is designed to overcome the singularities through the scheme that switches between an approximate tracking law close to the singularities, and an exact tracking law away from the singularities. But, that form has problems which may break the system's stability through unstable control input value at switching procedure. In this paper, We propose new switching control law which supervises approximate tracking control law and exact tracking control law by fuzzy rules to overcome unstability problem in switching procedure.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.3
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• pp.270-278
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• 2013

This paper proposes a control method for high voltage direct current(HVDC) with modular multilevel converter (MMC) under unbalanced voltage conditions considering the submodule(SM)'s current capacity and circulating current. It is aimed to propose a control method in which the current peak value does not exceed the maximum value of HVDC-MMC by considering the current capacity of the SM under unbalance voltage conditions. And it analyzes the effect of the unbalanced voltage on circulating currents in MMC and then proposes a control method considering each component of circulating currents under unbalanced voltages. The effectiveness of the proposed controlling method is verified through simulation results using PSCAD/EMTDC.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.228-238
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• 2017

The CALEB10 is a multi-legged biomimetic underwater robot. In the last research, we developed a swimming pattern named ESPG (Extended Swimming Pattern Generator) by observing diving beetle's swimming actions and experimented with a positive buoyancy state in which CALEB10 floats on the water. In this paper, however, we have experimented with CALEB10 in a neutral buoyancy state where it is completely immersed in water for pitch motion control experiment. And we found that CALEB10 was unstably swimming in the pitch direction in the neutral buoyancy state and analyzed that the reason was due to the weight proportion of the legs. In this paper, we propose a pitch motion control method to mimic the pitch motion of diving beetles and to solve the problem of CALEB10 unstably swimming in the pitch direction. To control the pitch motion, we use the method of controlling additional joints while swimming with the ESPG. The method of obtaining propulsive force by the motion of the leg has a problem of giving propulsive force in the reverse direction when swimming in the surge direction, but this new control method has an advantage that a propulsive moment generated by a swimming action only on a target pitch value. To demonstrate validity this new control method, we designed a dynamics-based simulator environment. And the control performance to the target pitch value was verified through simulation and underwater experiments.