• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.783-787
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• 1993

The dynamics for a two-body problem including perturbations due to nonspherical gravitation of the earth, gravitation of the sun and moon, radiation of the sun is studied. Orbit determination was performed by SVD filter. The simulation result shows that the characteristics of the satellite orbit have east-west and south-north drift. Therefore, the periodic magnitude of the control time and value in the view of the periodicity of error can be provided, and this result can be basic data to a station keeping problem with an orbit determination result.

• Journal of Korean Elementary Science Education
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• v.21 no.2
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• pp.143-157
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• 2002

The aims of this study are to develop web-based learning materials for science and environmental education of elementary school. The effect of environmental education was divided into eight to measure: the awareness of using web as environmental material, the ability to use web as environmental material. the awareness of environmental problems, the satisfaction for environmental education using web, the awareness of preserving local environment, self-leading ability to learn environment, the effect of using environment homepage, and the internalization of environmental awareness. This study obtained the following results; First, as a result of post-test, the average of the test group of web-based learning was 1.29 points higher than the control group having traditional learning in the awareness of using web as environmental material, showing a statistically significant difference. Second, as a result of post-test, the average of the test group of web-based learning was 2.80 points higher than the control group in the ability to use web as environmental material, showing a statistically significant difference. Third, as a result of post-test, the average of the test group of web-based learning was 1.10 points higher than the control group in the awareness of environmental problems, showing a statistically significant difference. Fourth, as a result of post-test, the average of the test group of web-based teaming was 0.89 points higher than the control group in the satisfaction for environmental education using web, showing a statistically significant difference. Fifth, as a result of post-test, the average of the test group of web-based learning was 1.70 points higher than the control group in the self-leading ability to learn environment, showing a statistically significant difference. Sixth, as a result of post-test, the average of the test group of web-based learning was 1.21 points higher than the control group in the effect of using environment homepage, showing a statistically significant difference. Finally, as a result of post-test, the average of the test group of web-based learning was 1.39 points higher than the control group in the internalization of environmental awareness, showing a statistically significant difference. Based on these results, it is assumed that the teaching method which applied web-based teaming to science and environmental education in elementary school is a effective strategy for elementary science and on environmental education.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.578-583
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• 1992

In this paper, we show that various navigation constant values in PNG law can result in as optimal gains when we introduce proper time-varying weighting functions into the cost function of an optimal control problem. we then apply this idea to the guidance problem where we are required to achieve a given impact angle as well as the zero miss distance. As a result, we obtain a set of optimal guidance laws each of which could be related to a navigation constant in PNG. Some basic properties of these guidance laws are also presented.

• Korean journal of food and cookery science
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• v.15 no.2
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• pp.171-177
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• 1999

The purpose of this study was to serve a standard of the good quality control and shelf-life of food and beverage served from the vending machines. So it was performed to examine the temperature (internal & external environmental, food itself), pH, Aw, POV and microbiological quality of Adlay tea and Wheat noodles served from the vending machines based on storage time in the machines. They were assessed to find the critical control point(CCP) during each of the production, delivery, purchasing phases from the vending machines. The result of this study can be summarized as follows: 1. The temperature of foods inside the vending machines was ranged from 4$0^{\circ}C$ to 45$^{\circ}C$. It was in the range of dangerous zone. The average temperature of food showed 71$^{\circ}C$ for Adlay tea and 74$^{\circ}C$ for Wheat noodles. As a result of measuring pH and Aw, they had potential danger. 2. Even though POV was low, it increased as the time passed. 3. As a result of microbial analysis, it showed that the amount of total plate count and coliforms were increased ten times after 1 day respectively. Wheat noodles' coliform and total plate counts exceeded standard value in 1 day. As a result of food poisoning bacteria, it was negative in sample against Vibrio parahaemolyticus, Salmonella, Staphylococcus aureus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3478-3485
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• 2011

This study utilized the GPS data of the stations of triangulation of Changwon-si, Gyeongsangnam-do to conduct comprehensive analysis on tolerance level and regional characteristics. Based on this analysis, it was attempted to seek the method to derive more accurate result when further performing cadastral control point surveying for cadastral detail surveying. For the stations of triangulation installed at time of the land survey project, the study result showed that the most results of the stations of triangulation are stable if they were not moved naturally or artificially by themselves. Therefore, it was concluded that the stations of triangulation installed at the time of the land survey project should be preemptively selected for use of the given points when making decision of result of cadastral control point surveying. In addition, if the result of the cadastral control point surveying is made decision based on the stations of triangulation presented as the stable result in this study result, it seems that the same surveying result will be maintained and managed at all time, even if they are going to be further reinstalled due to loss of them.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1380-1385
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• 2004

In this paper, auto-tuning technique of the PID controller gain by particle swarm optimization algorithm is presented. PID controller is easy to implement to numerous control systems. After PID gain tuning is completed, its result could be implemented to control spacecraft vibration such as jitter that is high frequency vibration usually over 10Hz. The off-line PID controller tuning is done under system nonlinearities and uncertainties existence, then its result is applied to control experiment device to prove the PSO efficiencies.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.333-335
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• 2001

A simple control strategy of DO-stat was introduced to the recombinant rGuamerin production process in Pichia pastoris. This induction strategy consisted of two interrelated control loops ‘by which oxygen ratio of inlet gas and methanol feeding rate was controlled. Using this control strategy, over-feeding or under-feeding of methanol could be avoided in concomitance with the efficient control of dissolved oxygen level. As a result, the cell concentration reached 130 g/L and rGuamerin expression level was 450 iu/L, which was more than 40% increased result comparing with the fed-batch process using manual control of methanol feeding rate.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.1
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• pp.24-30
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• 2008

A simulation of hot strip finishing mill automatic gauge control (AGC) system is built, which is divided into four modules such as rolling mill system, AGC module, looper system and strip model. The rolling mill system is built by mechanism modeling, the looper system and strip model are built by function modeling, and the AGC model is tried to use intelligent control of a multi-function AGC system. The target is attempted to use this simulation object to minimize finisher exit strip thickness deviation resulting from strip entry thickness disturbance and rolling force deviation. Simulation results show that the result of this AGC/LPC synthetical system module simulation is quite close to the actual result. The simulation system can also analyze most kinds of disturbance which affect the rolling process. It is proved that the system can represent practical situation of hot strip finishing mill process control, and be used as a basic platform of research and development for researcher and engineer.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.127-137
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• 2000

This paper presents a novel neural based controller which controls the water level of the nuclear power plant steam generator. The controller consists of a model reference feedback linearization controller and a PI controller for stabilizing the feedback linearization controller. The feedback linearization controller consists of a neural network model and an inversing module which uses the neural network model for computing the control input to the steam generator. We chose Piecewise Linearly Trained Network(PLTN) and Recurrent Neural Netwrok(RNN) for an approximator of the plant and used these approximators in calculating the input from the feedback linearization controller. Combining the above two controllers gives a result of better performance than the case which uses only a PI controller Each control result of PLTN and RNN is given.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.284-291
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• 2007

This study was to investigate performance of position, basic controls and additional control for man-machine interface on a 3-point hitch of a tractor. The developed additional control was one-touchup, backup, turnup, liftarm limited, PTO on/off and an external control. As a result of experiment, maximum steady state error of response system was lower than $0.8^{\circ}$ and this result showed the function operated normally because the dead band of system set was ${\pm}1^{\circ}$. There was no abnormal situation by switch operation and sensor signal during the performance test. The results of experiment showed the characteristics of the response was sufficient to be used as the position and additional control system for tractors.