• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.770-775
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• 2002

In this paper, a game optimal receding horizon guidance law (GRHG) is proposed, which does not use information of the time-to-go and target maneuvers. It is shown that by adjusting design parameters appropriately, the proposed GRHG is identical to the existing receding horizon guidance law (RHG), which can intercept the target by keeping the relative vertical separation less than the given value, within which the warhead of the missile is detonated, after the appropriately selected time in the presence of arbitrary target maneuvers and initial relative vertical separation rates between the target and missile. Through a simulation study, the performance of the GRHG is illustrated and compared with that of the existing optimal guidance law (OGL).

• 전기의세계
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• 제28권5호
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• pp.44-48
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• 1979

For ordinary systems the receding horizon method has beer proved by the author as a very useful and easy tool to find stable feedback controls. In this paper an open-loop optimal control which minimizes the control energy with a suitable upper limit and terminal control and state constraints is derived and then transformed to the closed-loop control. The stable feedback control law is obtained from the closed-loop control. The stable feedback control law is obtained from the closed-loop control by the receding horizon concept. It is shown by the Lyapunov method that the control law derived from the receding, horizon concept is asymtotically stable under the complete controllability condition. The stable feedback control which is similar to but more general than the receding horizon control is presented in this paper To the author's knowledge the control laws in this paper are easiest to stabilize systems with delay in control.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2081-2086
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• 2005

This paper proposes the receding horizon $H_{\infty}$ predictive control (RHHPC) for systems with a state-delay. We first proposes a new cost function for a finite horizon dynamic game problem. The proposed cost function includes two terminal weighting terns, each of which is parameterized by a positive definite matrix, called a terminal weighting matrix. Secondly, we derive the RHHPC from the solution to the finite dynamic game problem. Thirdly, we propose an LMI condition under which the saddle point value satisfies the well-known nonincreasing monotonicity. Finally, we shows the asymptotic stability and $H_{\infty}$-norm boundedness of the closed-loop system controlled by the proposed RHHPC. Through a numerical example, we show that the proposed RHHC is stabilizing and satisfies the infinite horizon $H_{\infty}$-norm bound.

• Journal of Communications and Networks
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• 제16권3호
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• pp.293-300
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• 2014

As energy harvesting communication systems emerge, there is a need for transmission schemes that dynamically adapt to the energy harvesting process. In this paper, after exhibiting a finite-horizon online throughput-maximizing scheduling problem formulation and the structure of its optimal solution within a dynamic programming formulation, a low complexity online scheduling policy is proposed. The policy exploits the existence of thresholds for choosing rate and power levels as a function of stored energy, harvest state and time until the end of the horizon. The policy, which is based on computing an expected threshold, performs close to optimal on a wide range of example energy harvest patterns. Moreover, it achieves higher throughput values for a given delay, than throughput-optimal online policies developed based on infinite-horizon formulations in recent literature. The solution is extended to include ergodic time-varying (fading) channels, and a corresponding low complexity policy is proposed and evaluated for this case as well.

• International Journal of Control, Automation, and Systems
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• 제1권2호
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• pp.163-170
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• 2003

The optimal Bayesian filter for a single target is known to provide the best tracking performance in a cluttered environment. However, its main drawback is the increase in memory size and computation quantity over time. In this paper, the inevitable predicament of the optimal Bayesian filter is resolved in a suboptimal fashion through the use of a receding horizon strategy. As a result, the problems of memory and computational requirements are diminished. As a priori information, the horizon initial state is estimated from the validated measurements on the receding horizon. Consequently, the suboptimal algorithm proposed allows for real time implementation.

• 대한전기학회논문지:전력기술부문A
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• 제48권7호
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• pp.815-823
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• 1999

This study considers an implementation of artificial neural networks to the receding horizon optimal control and is applications to power systems. The Generalized Backpropagation-Through-Time (GBTT) algorithm is presented to deal with a quadratic cost function defined in a finite-time horizon. A decentralized approach is used to control the complex global system with simpler local controllers that need only local information. A Neural network based Receding horizon Optimal Control (NROC) 1aw is derived for the local nonlinear systems. The proposed NROC scheme is implemented with two artificial neural networks, Identification Neural Network (IDNN) and Optimal Control Neural Network (OCNN). The proposed NROC is applied to a power system to improve the damping of the low-frequency oscillation. The simulation results show that the NROC based power system stabilizer performs well with good damping for different loading conditions and fault types.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.140-144
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• 2010

In the case of a linear time-varying system, it is difficult to apply the conventional stability conditions of RHC (Receding Horizon Control) to real physical systems because of computational complexity comes from time-varying system and backward Riccati equation. Therefore, in this study, a frozen time RHC for a linear discrete time-varying system is proposed. Since the proposed control law is obtained by time-invariant Riccati equation solved by forward iterations at each control time, its stability can be ensured by matrix inequality condition and the stability condition based on horizon for a time-invariant system, and they can be applied to real physical systems effectively in comparison with the conventional RHC.

• 아시안잔디학회지
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• 제9권1호
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• pp.75-80
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• 1995

In eight golf courses of southern area fair way soil profile was investigated for soil physical, chemical properties, and root distribution. These were carried out only A horizon(lScm depth) in one golf course. Soil series was all different, Leaching to lower horizon was greator in order of Mg=$NO_3$> $NH_4$=Ca> K. Organic matter content was higher in B horizon than A in three golf courses. Soil phosphorus appeared to more down greatly in two golf courses. Soil pH was higher in lower horizon of all places. Such pH increase with depth seemed to he related with mineral leaching, Among the horizons of all golf courses BC showed significant correlation with K (EC =0.1025K +0.0157, r=0. 8012 p=0. 001 n=20). Both Fe and Mn were higher in A horizon.

• 대한안전경영과학회지
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• 제23권4호
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• pp.105-112
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• 2021

This paper presents a periodic replacement policy for a system subject to shocks when the system is operating for a finite random horizon. The system is subject to shocks during operation, and each shock causes downgrading of the system performance and makes it more expensive to run by the additional running cost. Shocks arrive according to a nonhomogeneous or a renewal process, and we develop periodic replacement policies under a finite random operating horizon. The optimum periodic replacement interval which minimizes the total operating cost during the horizon is found. Numerical examples are presented to demonstrate the results.

• 한국토양비료학회지
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• 제48권5호
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• pp.428-435
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• 2015

Pedotransfer functions (PTFs) were developed for each soil horizon to estimate hydraulic characteristics of mountainous forest soils in South Korea. Twenty one dominant soil series from 8 soil catenae such as granite-originated catena and volcanic ash-originated catena were selected for the study; gravel contents of selected soils were 10% or lower. Saturated conductivity (Ks) was measured for each horizon in situ. Particle size distribution and organic matter content of each horizon were also determined. Based on correlation analysis with total data set, sand separate showed positive relationship with Ks ($r=0.24^*$) while clay separate had negative relationship with Ks ($r=-0.29^{**}$). The correlation coefficients of sand, clay, and organic matter content with Ks increased to $0.41^{**}$, $-0.67^{***}$, and $0.58^{***}$, respectively, using data from granite- or gneiss-originated catena with exception of volcanic ash-originated catena and sedimentary rock-originated catena. Determination coefficients of PTFs were 0.31 for A horizon, 0.25 for B, and 0.35 for C with all data set while those were 0.74 for A, 0.48 for B, and 0.54 for C. Organic matter was a dominant factor affecting Ks in A horizon but clay content was selected as the only factor influencing Ks in C horizon. It implies that PTFs should be developed with understanding characteristics of parent materials and horizons. Developed PTFs for granite- or gneiss-originated catena were following: A horizon: Log ($K_s{\times}10^7$) = -0.031C + 0.398OM + 3.49 B horizon: Log ($K_s{\times}10^7$) = -0.028C + 0.141OM + 4.05 C horizon: Log ($K_s{\times}10^7$) = -0.072C + 4.66 where C is clay separate (%) and OM is organic matter content ($g\;kg^{-1}$). The unit of Ks is cm $sec^{-1}$.