• Journal of Drive and Control
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• v.15 no.3
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• pp.1-7
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• 2018

Humanoid robots have fascinated many researchers since they appeared decades ago. For the requirement of both accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Humanoid robots are highly nonlinear, coupled, complex systems, accordingly the calculation of robot model is difficult and even impossible if precise model of the humanoid robots are unknown. Therefore, it is difficult to control using traditional model-based techniques. To realize model-free torque control, time-delay control (TDC) for humanoid robot was proposed with time-delay estimation technique. Using optimal walking trajectory obtained by particle swarm optimization, TDC with proposed scheme is implemented on whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the proposed TDC for humanoid robots.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.161-167
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• 2008

In this paper, the optimal design of trusses using advanced analysis and genetic algorithm is performed. An advanced analysis takes into account geometric nonlinearity and material nonlinearity. The micro genetic algorithm is used as optimization technique. The weight of structures is treated as the objective function. The constraint functions are defined by load-carrying capacities and displacement requirement. The effectiveness of the proposed method is verified by comparing the results of the proposed method with those of other method.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.61-65
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• 2004

As technique that can contribute in quality improvement in design process to overcome shortcoming of traditional quality control, call design or development department quality control activity that is achieved to reduce gun damage shuddering at circle minimizing change or side effect of product performance as off-line quality control. This paper discuss optimal process design of investment projects expansion and replacement investment on each line or individual in the production. Generally optimal plant design has add to a few method by Subsidiary means with use a especial method. And then in this paper, a Robust design is presented, which may be effective to the processes appraisal or improvement. We propose that should make a optimal plant design model for reducing field failure rate to assign by real data on different factors in plant system. Using this model, robust design of taguchi method used in this comprehensive method for reducing field failure rate in plant system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.7
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• pp.430-436
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• 2004

This paper presents an advanced control technique for power density maximization of the Brushless DC (BLDC) generator by using the linear tracking method. In a generator of given rating, the weight and size of the system affect the fuel consumption directly. Therefore, power density is one of the most important issues in a stand-alone generator. BLDC generator has high power density in the machine point of view and additional increases of power density by control means can be expected. Conventional rectification methods cannot achieve the maximum power possible because of hon-optimal current waveforms. The optimal current waveform to maximize power density and minimize machine size and weight in a nonsinusoidal power supply system has been derived, incorporated in a control system, and verified by simulation and experimental work. A new simple algebraic method has been proposed to accomplish the proposed control without an FFT which is time consuming and complicated.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1186-1192
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• 1994

This paper presents an algorithm to design a robust digital model following servo control system in which optimal linear quadratic regulator problem is used to design the control system that make the step/ramp response of the plant kept close to a specified ideal step/ramp response of the model. The quadratic criterion function for a continuous system is used to design the robust digital servo control system. The feasibility of the design technique is shown by the simulation and the proposed method is applied to the speed control of DC servo motor.

• Geomechanics and Engineering
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• v.5 no.6
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• pp.519-540
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• 2013

This paper presents an optimal design method for determining pile lengths of piled raft foundations. The foundation settlement is evaluated by taking into account the raft-pile-soil interaction. The analysis of settlement is simplified by using Steinbrenner's equation. Then the total pile length is minimized under the settlement constraint. An extended sequential linear programming technique combined with an adaptive step-length algorithm of pile lengths is used to solve the optimal design problem. The accuracy of the simplified settlement analysis method and the validity of the obtained optimal solution are investigated through the comparison with the actual measurement result in existing piled raft foundations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.269-276
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• 2007

Optimal thickness and shape of the pedal arm of an automotive clutch is determined, using the numerical optimization technique, by solving the size and shape optimization problems to minimize its weight. For the optimization problems, two cases of stress and displacement constraints are considered: one from the vertical, and the other from the transverse stiffness test condition. The result of the transverse case is shown to be more conservative than that from the vertical case, being determined as the final optimum.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.1-8
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• 2010

A vendor selection problem consists of two different kinds of decision making. First one is to choose the best suppliers among all possible suppliers and the next is to allocate the optimal quantities of orders among the selected vendors. In this study, an integration of the technique for order preference by similarity to ideal solution (TOPSIS) and a multi-objective mixed integer programming (MOMIP) is developed to account for all qualitative and quantitative factors which are used to evaluate and choose the best group of vendors and to decide the optimal order quantity for each vendor. A solution methodology for the vendor selection model of multiple-vendor, multiple-item with multiple decision criteria and in respect to finite vendor capacity is presented.

• ETRI Journal
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• v.36 no.4
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• pp.682-685
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• 2014

In this letter, we propose an efficient near-optimal detection scheme (that makes use of a generalized sphere decoder (GSD)) for blind multi-user multiple-input multiple-output (MU-MIMO) systems. In practical MU-MIMO systems, a receiver suffers from interference because the precoding matrix, the result of the precoding technique used, is quantized with limited feedback and is thus imperfect. The proposed scheme can achieve near-optimal performance with low complexity by using a GSD to detect several additional interference signals. In addition, the proposed scheme is suitable for use in blind systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.11
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• pp.1424-1428
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• 1999

This paper presents a mathematical decomposition coordination method to implementing the distributed optimal power flow (OPF), wherein a regional decomposition technique is adopted to parallelize the OPT. The proposed approach is based on the Alternating Direction Method (ADM), a variant of the conventional Augmented Lagrangian approach, and makes it possible the independent regional AC-OPF for each control area while the global optimum for the entire system is assured. This paper is an extension of our previous work based on the auxiliary problem principle (APP). The proposed approach in this paper is a completely new one, however, in that ADM is based on the Proximal Point Algorithm which has long been recognized as one of the attractive methods for convex programming and min-max-convex-concave programming. The proposed method was demonstrated with IEEE 50-Bus system.