• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.5
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• pp.46-52
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• 2003

In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with mill operation data demonstrates the effectiveness of the model identified.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2004.04a
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• pp.97-106
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• 2004

The paper making process itself is a typical nonlinear process with complicated dynamics. In the application of advanced control-methods especially for the grade change operations the nonlinear process is linearized to give suitable linear models to be used in the control strategies. However, the use of the linear model is limited within short range containing steady-state operating conditions for grade change operation. In this paper a bilinear model for the nonlinear grade change processes is presented. We can see that the dynamic behavior for grade change operations can be effective analyzed by using multivariable bilinear model.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.11a
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• pp.291-305
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• 2003

In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with plant operation data demonstrates the effectiveness of the model identified.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2004.04a
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• pp.107-114
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• 2004

In this work the Model algorithmic control method is applied to control the grade change operations in paper mills. The neural network model for the grade change operations is identified first model is then extracted from the neural model. Results of simulations for MAC control of grade change operations are compared with plant operation data response. From the comparison, we can see that the proposed MAC method exhibits faster response for the grade change of paper and achieves stable steady-state.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.1 s.109
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• pp.61-66
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• 2005

The grade change operations In paper mills exhibit inherent nonlinear dynamic characteristics. For this reason, the conventional model predictive control techniques based on linear process models are not adequate for the grade change operations. In this paper, a bilinear model for the nonlinear grade change processes was presented first and optimal input variables were calculated by using one-step-ahead predictive control method. Numerical simulations showed that the control performance lied within acceptable range and that the bilinear model predictive control scheme was highly promising control strategy for the grade change operations.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.1 s.109
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• pp.67-72
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• 2005

In the grade change operations inputs and outputs are highly correlated and application of conventional linear feedback control methods such as PID schemes might lead to poor control performance. In this study the neural networks model for the grade change operation is trained by using bilinear terms which can represent non-linear characteristics of grade change operations. The inverse model of the grade change operation is obtained from training and the optimal input variables are computed from the trained neural networks as well. The proposed bilinear inverse model predictive control scheme was found out to showlittle discrepancy between simulated outputs and setpoints.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2004.04a
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• pp.86-96
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• 2004

Identification of dynamics of short circulation during grade change operations in paper mills is very important for the effective plant operation. In the present study a prediction method of One Pass Retention(OPR) is proposed based on the neural network. The present method is used to analyze the dynamics of short circulation during grade change. Properties of the product paper largely depend upon the change in the OPR. In the present study the OPR is predicted from the training of the network by using grade change operation data. The results of the prediction are applied to the modeling equation to give flow rates and consistencies of short circulation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.1
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• pp.157-171
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• 2009

Objective : The face is very important for human communication. So facial palsy patients experience not only physical disturbances but also serious emotional stress. Therefore the focus of treatment must be to not only aid the recovery of objective symptoms but also the improvement of subjective quality of life. However there has not been enough Oriental Medical study in this field until now. Thus this study was begun to suggest a useful index for the treatment of facial palsy. Methods : Grade of paralysis, sequelas, and quality of life were used for evaluation. To evaluate Grade of paralysis, House-Brackman Grade was used as the Gross scale and Kim's Grade was used as the Regional scale. Sequelas were evaluated by muscle contraction, synkinesis, NA, and grade of philtrum tilt. Quality of life was evaluated by SF-36v2, Facial Disability Index, and Vas. Results & Conclusion : 1. The change of grade of paralysis between the early and the present time reveals remarkable improvement statistically. 2. There was a remarkable improvement in all parts of quality of life except several areas of SF-36(RP, RE, MH, VT) 3. In only PF(Physical Function) of FDI, quality of life increased remarkably according to the improvement of grade of paralysis. 4. There is the positive relationship among Kim's grade, HB grade and Synkinesis 2. 5. Synkinesis among sequelas has the greatest effect on quality of life. And muscle contraction, change of NA, and grade of philtrum tilt also affect quality to some extent. 6. There was no remarkable relationship between the period of illness and change of quality of life. 7. Change of NA is shown after 3 months of illness and synkinesis becomes worse after 6 months of illness.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.36-39
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• 2006

Objective : The present study attempts to address the change of management results over time during the past 13 years in good-grade patients with intracranial aneurysm. Methods : Six hundred twenty five [Hunt-Hess grade I to III] out of 826 patients with ruptured intracranial aneurysms operated by the same operator within 3 days after the attack from 1990 to 2002 were selected. Since 1998, endovascular aneurysmal occlusion was done in selected cases of 21 patients. The change of management results over time, including rebleeding rate, delayed ischemic neurologic deficit[DIND] as a cause of morbidity and mortality and surgical outcome were examined. Results : The ratio of poor-grade patients in all patients tended to decrease over the years. The early rebleeding rate declined from 5.0% to 1.2% with the use of tranexamic acid and computed tomography angiogram DIND as a cause of mortality and morbidity has decreased from 12.5% in 1990 to approximately 0% currently. Surgical outcome began to improve significantly in 1994 [poor outcome : 25% in 1990, 12.2% in 1994,6.8% in 2002]. Conclusion : These results suggest that the advances in care and increased experience of the operator significantly affect the change of overall outcome, and early detection of the aneurysm is needed for reducing the ratio of poor-grade patients.

• The Korean Journal of Health Service Management
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• v.8 no.1
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• pp.51-64
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• 2014

The purpose of this study was to investigate the relationship among staffing, occupancy rate, upward level change of long-term care need, and evaluation grade of facility. Data were obtained from National Health Insurance Corporation Database. Occupancy rate and evaluation grade were highest in National/public operating facilities, while they were worst in individual operating facilities. The percents of A or B grade in evaluation grade (by newly enforced law) is highest in National/public operating facilities. Multiple regression analysis showed that upward level change of care needs was very weakly associated with the number of doctors. Evaluation grade showed a weak and significant association with occupancy ratey(by old-version law)(r=.20, p<.01), upward level change of care need in group home(r=.23, p<.01) Staffing in facility did not show significantly consistent association with upward level change of care needs, evaluation grade, and occupancy rate.