• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.339-344
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• 1993

A study for a lathe to machine workpieces with noncircular corss-sections is presented. The noncircular cutting is accomplished by controlling the radial tool position synchronized with the revolution angle of spindle. A learning control algorithm is suggested for the toll positioning, of which the control performances are analyzed and simulated on a numerical computer that the effectiveness of the control is convinced. The learning control is tested on a NC-lathe which shows successful results.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.490-495
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• 1992

A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming cooperates with neural identification network is used to generate the optimum control law for the complicate continuous/batch chemical reactor systems that have inherent nonlinear dynamics. Based on our approach, we developed a neural model predictive controller(NMPC) which shows excellent performances on nonlinear, model-plant mismatch cases of chemical reactor systems.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1066-1071
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• 1992

A new scheme of OFVSC(Output Feedvack Variable Structure Controller) is proposed for the servo control system. The main structure of proposed control scheme is composed of servo compensator and dynamic switiching function. By the use of dynamic switiching function the assumption of full state availability can be removed and the disturbances which does not satisfy the matching condition cna be rejected. And the servo compensator which is designed for each output variable the robustness for the all type of disturbances. And the performances of proposed control system are evaluated through simulation studies for a numerical example.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.35-38
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• 2000

Since the telemanipulator consisting of high reduction ratio gear joints has a slow dynamics comparing with the master manipulator, its control signal is likely to be saturated resulting in poor tracking performance and deteriorated stability. This paper proposes a bilateral control scheme of a telemanipulator having high reduction ratio, which can compensate the control input saturation. The experimental results show that the proposed control scheme has excellent performances.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.67
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• pp.11-18
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• 2001

The efficiency and robustness of the scale estimator based on the Gini's mean difference are well known in Nam et al.(2000). In this paper we propose use of robust control limits based on the Gini's mean difference for the control of the process deviation. To compare the performances of the proposed control chart with the existing R-chart or S-chart, some Monte Carlo simulations are performed. The simulation results show that the use of the Gini's mean difference in construction of the control limits has good performance.

• Journal of information and communication convergence engineering
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• v.5 no.1
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• pp.54-58
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• 2007

A real-time frame-layer rate control algorithm with a token bucket traffic shaper is proposed for distortion variation minimization. The proposed rate control method uses a non-iterative optimization method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder. Experimental results indicate that the proposed control method provides better visual and PSNR performances than the existing rate control method.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.27-29
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• 2009

Real-time control of on-site construction, based on high quality data, is essential to identify discrepancies between actual and planned performances. Additionally, real-time control enables timely corrective measures to be taken when needed to reduce the damages caused by the discrepancies. The focus of the presentation will be on our work, which uses automated data technologies to collect data needed for real time control.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.471-478
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• 2011

This paper proposes a method of maximum power point tracking (MPPT) using fuzzy logic control for grid-connected photovoltaic systems (PV). First, for the purpose of comparison, because of its proven and good performances, the incremental conductance (IncCond) technique is briefly introduced. A double fuzzy logic controller (DFLC) based MPPT is then proposed which has shown better performances compared to the IncCond MPPT based approach. Modeling and Simulation in grid-connected PV system results are provided for both controllers under same atmospheric condition based PSCAD/EMTDC. The double fuzzy logic MPPT controller is then simulated and evaluated, which has shown better performances.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.5
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• pp.85-93
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• 2004

This study was carried out to find out the effect of cool-season turfgrass overseeding onto zoysiagrass(Zoysia japonica L.) for extending green color and solving traffic problem during dormant periods. Overseeding rates of cool-season turfgrasses were $10g/m^2$ of Kentucky bluegrass(KB1), $20g/m^2$of Kentucky b1uegrass(KB2), $60g/m^2$ of perennial ryegrass(PR), $80g/m^2$ of Tall fescue(TF), and $10g/m^2$ of Kentucky bluegrass + $10g/m^2$ of perennial ryegrass mixture(KB+PR) onto 2m${\times}$2m(width${\times}$length) zoysiagrass plots with 3 replications.1 to 9-sca1e of visual quality and visual color were measured after treatment, Consequently cool-season turfgrass overseeding gave a good performances of extending the green periods and enhancing the turf grass quality. KB1 and KB2 were found to be excellent performances for visual quality and visual color compared to PR, TF, KB+PR and control. KB2 showed better turf performances than KB1 within Kentucky bluegrass overseedings. Turfgrass color was kept up for 10 months by overseeding of cool-season turfgrasses(KB1, KB2, PR, TP, KB+PR) compared to about 5~6 months by zoysiagrass(Control). The visual quality and visual color of PR and TF showed good performances during a green-up period of spring, but decreasing tendencies through the summer.Percent diseases data revealed also higher ratings for PR and TF compared to for KB1 and KB2.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.131-136
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• 2013

The present study has conducted cycle design and control technology of a water source VRF heat pump system. Previously, study of a simultaneous heating and cooling in an air source VRF heat pump system has been conducted. However, performance data and design methods for simultaneous heating and cooling in a water source VRF heat pump system are limited in the literature, due to various system parameters and operating conditions. In this study, the operating characteristics and performances of a simultaneous heating and cooling heat pump system are carried out, in simultaneous operation modes. Control logics of an EEV are developed for flow rate control to the outdoor unit, and are verified. When the control logics are applied, the simultaneous cooling and heating performances are sufficiently achieved, and system COPs are increased by up to 23.4%.