• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.42.1-42
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• 2002

A model to predict population by sex, age and district over a long-range period is proposed based on fuzzy theories. First, a fuzzy model is described. Second, a method to estimate the social increase by sex and age in each district is proposed based on a fuzzy clustering method for dealing with long-range socioeconomic changes in population migration. By the proposed methods, it became possible to predict the population by sex, age and district over a long-range period. Third, the structure and characteristics of the three models of employment model, time distance model, and land use model constructed to predict various socioeconomic indicators, which are require...

• Structural Engineering and Mechanics
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• v.74 no.6
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• pp.821-832
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• 2020

The fundamental period is an important parameter for seismic design and seismic risk assessment of building structures. In this paper, a simplified theoretical method to predict the fundamental period of masonry infilled reinforced concrete (RC) frame is developed based on the basic theory of engineering mechanics. The different configurations of the RC frame as well as masonry walls were taken into account in the developed method. The fundamental period of the infilled structure is calculated according to the integration of the lateral stiffness of the RC frame and masonry walls along the height. A correction coefficient is considered to control the error for the period estimation, and it is determined according to the multiple linear regression analysis. The corrected formula is verified by shaking table tests on two masonry infilled RC frame models, and the errors between the estimated and test period are 2.3% and 23.2%. Finally, a probability-based method is proposed for the corrected formula, and it allows the structural engineers to select an appropriate fundamental period with a certain safety redundancy. The proposed method can be quickly and flexibly used for prediction, and it can be hand-calculated and easily understood. Thus it would be a good choice in determining the fundamental period of RC frames infilled with masonry wall structures in engineering practice instead of the existing methods.

• Osong Public Health and Research Perspectives
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• v.5 no.4
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• pp.187-192
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• 2014

Objectives: Measurement of the incidence of the human immunodeficiency virus (HIV) is very important for epidemiological studies. Here, we determined the recency period with the AxSYM avidity assay and the BED-capture enzyme immunoassay (BED-CEIA) in Korean seroconverters. Methods: Two hundred longitudinal specimens from 81 seroconverters with incident HIV infections that had been collected at the Korea National Institute of Health were subjected to the AxSYM avidity assay (cutoff = 0.8) and BED-CEIA (cutoff = 0.8). The statistical method used to estimate the recency period in recent HIV infections was nonparametric survival analyses. Sensitivity and specificity were calculated for 10-day increments from 120 days to 230 days to determine the recency period. Results: The mean recency period of the avidity assay and BED-CEIA using a survival method was 158 days [95% confidence interval (CI), 135-181 days] and 189 days (95% CI, 170-208 days), respectively. Based on the use of sensitivity and specificity, the mean recency period for the avidity assay and BED-CEIA was 150 days and 200 days, respectively. Conclusion: We determined the recency period to estimate HIV incidence in Korea. These data showed that the nonparametric survival analysis often led to shorter recency periods than analysis of sensitivity and specificity as a new method. These findings suggest that more data from seroconverters and other methodologies are needed to determine the recency period for estimating HIV incidence.

• Journal of Korean Physical Therapy Science
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• v.30 no.1
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• pp.1-9
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• 2023

Background: The advantages of robotic therapy have recently been attempted several times in the rehabilitation of total hip arthroplasty (THA) patients. Therefore, this study also aims to report a case of how robot therapy affects the function of THA patients due to developmental dysplasia of the hip (DDH). Design: Case Study. Method: This study used the A-B-A' design. Period A is before robotic therapy, period B is robotic therapy, and period A' is after robotic therapy. The subjects performed physical therapy and occupational therapy for five days each during the baseline period A and A'. In intervention period B, robotic therapy was performed for five days along with the baseline intervention. This study was conducted for a total of fifteen days. The subjects' sit to stand (STS), timed up and go (TUG), and 10 metre walk (10MW) were evaluated. Result:: STS and TUG were significantly improved in periods B and A' compared to period A (p<0.05), and STS was significantly improved in period A' compared to period B (p<0.05). 10MW showed no significant improvement in periods B and A' compared to period A. Conclusions: This study confirmed that robot therapy was an effective intervention in improving the function of women in their 30s who underwent THA due to DDH. In the future, a study comparing the control group should be performed.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.263-268
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• 2011

This study was carried out to investigate the effect of nursery period and block size on seedling quality and fruit yield of paprika (Capsicum annuum L. 'Cupra'). Seeds of paprika (Capsicum annuum L., Cupra) were sown in rockwool plugs. Seedlings were transferred and grown to the rockwool block different sizes: $5{\times}5$, $7.5{\times}7.5$ and $10{\times}10cm$ at sowing after 15 days. The plants were transplanted by 25, 30, 35, 40, 45 and 50 days we planted the seeds to the rockwool slabs. Seedling growth was not influenced by block size in the 25 day old plant, since then growed poorly with increasing nursery period in the $5{\times}5cm$ block size, plant height, stem diameter, fresh weight, dry weight have no difference from $10{\times}10cm$ and $7.5{\times}7.5cm$, but leaves and leaf area were higher $10{\times}10cm$ than the $7.5{\times}7.5cm$ block size. Growth of the paprika in field 80 days after sawing did not differ from nursery period and block size below 35 days old, but decreased with increasing nursery period and decreasing block size beyond 40 days old. Flowering did not differ from nursery period and block size below 35 days, but delayed with increasing nursery period and decreasing block size beyond 40 days old. The highest yield was obtained from 30 and 35 days old, and decreased with increasing nursery period and decreasing block size beyond 40 days old.

• International Journal of Control, Automation, and Systems
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• v.1 no.1
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• pp.83-92
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• 2003

The outdoor antenna servo system is subject to has significant torque disturbances from wind pressures and gusts on the antenna structures, as well as bearing and aerodynamic frictions. This control system should provide a sharp directivity in spite of the environmental disturbances and internal uncertainties. Therefore, the implementation of a real-time controller is necessary for the precise generation of the reference signal and robust tracking performance. In this paper, the discrete-time controller for the quick tracking of a target communication satellite is designed by applying the sampled-data $H_{\infty}$ control theory along with the reference signal generated by an improved conventional step-tracking algorithm. The sampled-data $H_{\infty}$controller demonstrates superior robustness for the longer sampling period when compared with a simple PID controller.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.423-427
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• 2001

This paper describes a control scheme for direct torque and flux control of Induction machines using space vector modulation. The proposed predictive flux control scheme has directly calculated the reference voltage space vector based on Stator flux errors in order to control the torque and flux. This proposed control scheme has not the requirement of a separate current error, thereby improving transient performance and also has the advantage of less torque ripple in steady state with a fixed switching period. The effect of proposed method has been proven by simulations. It is concluded that the proposed control topology produces better results for steady state operation than the classical direct torque control.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.816-821
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• 2001

The generation of isolated grids by pulsed converters with characteristics close to the mains of the utility companies is a pretentious task. For generation of three-phase four-wire isolated grids are presented possible topologies and the demands on the system control are processed. For control of all conceivable load and error conditions, an extensive control technology is necessary. This must permit unsymmetrical operating conditions for an unlimited period but recognize errors simultaneously and therefore an overloading the consumer and the power semiconductors reliable may prevent. Measurement results on an experimental plant show the problems to be solved.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1492-1495
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• 2005

This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the affine control scheme is employed to increase the degree of freedom; 2) the fuzzy-model-based periodic control is employed; and the control input is changed n times during one sampling period; 3) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system; but its discretization error vanishes as n approaches the infinity. 4) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.5-150
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• 2001

This paper deals with a modified repetitive control method for compensating automatic gauge control (AGC) to reduce the effect of skid mark which directly influence the quality of products in plate mill process. Since the skid mark on the plate have thermal difference, it makes a different stretching rate and deflection of thickness. Firstly, the (AGC) system and the plate mill process are described by considering function in each control levels. The skid mark of the plate in practical control fields is shown. Also, its frequency variation is given by on-line FFT analysis method. Secondly, a key idea of the modified repetitive control method with time varying period disturbance is represented and compared with standard repetitive control method. Lastly, in simulation ...