• Journal of Welding and Joining
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• 제21권1호
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• pp.66-71
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• 2003

The release of residual stress by mechanical loading and unloading is often performed in the fabrication of box structure fur steel bridge. The proper degree of loading and unloading is significant at release method of residual stress by mechanical loading because that degree is changed by material and geometric shape of welded structure. Therefore, the simulation model that could exactly analyze the release of residual stress by mechanical loading is to be necessary. In this study, the non-linear behavior of weldments under external loading and unloading, such as the decrease and increase of structure stiffness, was investigated by monitoring of nominal stress and strain. Tensile loading and unloading test and the proper degree of stress relaxation was measured by sectioning technique using strain gauge. Analysis model that is indispensable for the effective application of MSR method was established on the basis of test and measurement result.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.159-167
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• 2000

During the operation of crane system in the container yard, it is necessary to control the crane trolley position so that the swing of the hanging container is minimized. Recently an automatic control system with high speed and rapid transportation is required. Therefore, we designed a controller to control the crane system with disturbances and weight change. In this paper, we present the neural network two degree of freedom PID controller to control the swing motion and trolley position. Then we executed the computer simulation to verify the performance of the proposed controller and compared the performance of the neural network PID controller with our proposed controller in terms of the rope swing and the precision of position control. Computer simulation results show that the proposed controller has better performances than neural network PID with disturbances.

• 한국해양공학회지
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• 제13권3B호
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• pp.99-105
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• 1999

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers a robust stability of this 2DOF servosystem with nonlinear type uncertainty in the system, and a robust stability condition for the servosystem is introduced. This result guarantees that if the plant uncertainty is in the permissible set defined by the condition, gain tuning can be carried out to suppress the influence of the plant uncertainties and disturbance inputs.

• 제어로봇시스템학회논문지
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• 제3권1호
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• pp.1-8
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• 1997

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers robust stability of this 2DOF servosystem incorporating an observer to the structured and unstructured uncertainties of the controlled plant. A robust stability condition is obtained using Riccati inequality, which is written in a linear matrix inequality (LMI) and independent of the gain of the integral compensator. This result impies that if the plant uncertainty is in the allowable set defined by the LMI condition, a high-gain integral compensation can be carried preserving robust stability to accelerate the tracking response.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1951-1966
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• 2007

This research attempts to examine the effects of import penetration in an industry on the firms' decision of business diversification and provide an integrative framework including the determinants and results of the business diversification. The research results are as follows. First, the import penetration doesn't affect the degree of business diversification. Second, the more profitable their core business industry, the lower the degree of business diversification against the import penetration. In addition, both technology-related assets and marketing-related assets are necessary for business diversification when faced with the import penetration. Finally, the inverted U-shaped relationship is supported between the degree of business diversification and firm performance.

• 동력기계공학회지
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• 제3권1호
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• pp.50-54
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• 1999

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which integral compensation is effective only when there is modeling error for disturbance input. The present paper considers the design problem of 2DOF servosystem incorporating an observer. It is shown that if a state feedback gain and a observer gain satisfy a condition, the integral effect does not appear when modeling error or disturbance input exists. This result means that the servosystem does not behave as a 2DOF servosystem.

• 한방안이비인후피부과학회지
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• 제15권2호
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• pp.315-325
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• 2002

I experienced one case of 3 degree bum from the 14th in October to the 15th in November 2001 in Dongshin University Gwangju Oriental Medical Hospital ENT${\cdot}$ Dermatology. Administration of herbal medicine "PalmuITang-Gami", external medicine, acupunture, and venesection therapy, as a curative means of Stagnation of Ki and Stasis of blood achieved desirable effect. In the future, it is necessary more clinical study for developing of oriental medical therapy and oriental external medicine of 3th degree burn.

• 대한지구과학교육학회지
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• 제6권2호
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• pp.145-151
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• 2013

The aim of this research is clarify the relationship between concept understanding degree about the environment and environmental sensitivity and heighten understanding of environmental education target to pre-service elementary teacher. The subjects of this study are science education intensive course 65 students of B educational university. Concept understanding degree about the environment was separately investigated by 'the definition of environmental education', 'Write The positive concept of the natural environment education and briefly describe.''The negative concept of the natural environment education and briefly describe'. Next clarify the relationship between concept understanding degree about the environment and environmental sensitivity target to pre-service elementary teacher. Based on these results, propose an alternative to cultivate pre-service elementary teacher's knowledge about environmental education. Degree of understanding of the concept environmental education research results are as follows. First, Cognition degree about definition of environmental education of pre-service elementary teacher is correctly recognized generally. Second, They do not think deeply about natural environment when it comes to the positive concept of the natural environment of pre-service elementary teacher. Third, They have only a little interest in natural environment when it comes to the negative concept of the natural environment of pre-service elementary teacher. Correlation research results of degree of understanding of the concept of environmental and environmental sensitivity are as follows. High understanding degree of environmental education is high environmental sensitivity. Heighten environmental sensitivity of pre-service elementary teacher will be sustainable environmental education so education is necessary for environmental Sensitivity training.

• 대한간호
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• 제26권3호통권141호
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• pp.83-97
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• 1987

This study was conducted in order to find out the degree of working abilities by analyzing the necessary factors having effect on the working abilities of the 124 community health practititioners (CHP) in Choong Chung Nam Do. Data were collected by mean o

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.653-657
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• 1990

Since linearized equations of notion have much modelling errors, robust controller for disturbances and noises Is necessary for autopilot. In this paper, notion equations for underwater vehicle with six degree-of-freedom are derived and linearized. And robust autopilot for this system is designed by using LQG/LTR methodology.