Browsing by Author "Chen, YP"

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A new method for constructing sliding surfaces of linear time-invariant systems
(2000-04-01)
Chen, YP
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Chang, JL
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電控工程研究所
;
Institute of Electrical and Control Engineering
A new method for constructing the sliding surfaces is developed by using the pole-assignment method; unlike the usual cases, the pole-assignment method is applied to the aver all closed-loop system and not the system in the sliding mode. Most importantly, the design procedure is simple since the sliding sur;faces can be determined in art explicit farm. Also, three significant properties listed in a theorem are proved and demonstrated by a numerical example.
A novel modified grey model
(2003)
Chen, YP
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Li, KT
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a novel modified grey model GM(l,l), which possesses the characteristics of second-order differential equations. By adopting a remedial term, it could aid the GM(l,l) to reduce the error which is caused by the non-monotone sequence. In addition, another advantage of the novel modified GM(l,l) is to keep the simple computation and less data properties. Finally, simulation results will demonstrate the advantage of the proposed modified GM(l, I).
Convergence time for the linkage learning genetic algorithm
(2005-09-01)
Chen, YP
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Goldberg, DE
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資訊工程學系
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Department of Computer Science
This paper identifies the sequential behavior of the linkage learning genetic algorithm, introduces the tightness time model for a single building block, and develops the connection between the sequential behavior and the tightness time model. By integrating the first-building-block model based on the sequential behavior, the tightness time model, and the connection between these two models, a convergence time model is constructed and empirically verified. The proposed convergence time model explains the exponentially growing time required by the linkage learning genetic algorithm when solving uniformly scaled problems.
Effect of nitrogen incorporation into InAs layer in InAs/InGaAs self-assembled quantum dots
(2005-09-01)
Chen, JF
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Hsiao, RS
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Chen, YC
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Chen, YP
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Hsieh, MT
We present the results of nitrogen. incorporation into the InAs layer in InAs/InGaAs quantum dots (QDs). We show that this incorporation causes an asymmetric photoluminescence (PL) line shape and abnormally, large redshift of the PL peak from the quantum dots as temperature increases. In addition, this incorporation causes a large series resistance and a rapid increase in reverse current at a bias corresponding to the QD region. This effect is due to the formation of a deep trap at 0.34-0.41 eV, which depletes the carriers in the QD region. This depletion gives rise to a geometric resistance-capacitance time-constant effect for the ac conductivity of the free electrons in the top GaAs layer. This trap markedly alters the emission properties of the QD structure. The ac conductivity of the QD structure is governed by the thermal activation of trapped electrons rather than the electron emission from the QD confined states. This incorporation significantly increases the electron emission time from the QD region and, thus, can be used intentionally to modify the emission properties of the QD structure.
Force control of a single-link flexible arm using sliding-mode theory
(1998-03-01)
Chang, JL
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Chen, YP
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電控工程研究所
;
Institute of Electrical and Control Engineering
Motivated by the relation between a force acting on a flexible arm and the resultant bending deflection, this paper presents a force control technique simply via position control. The dynamic equations of a flexible arm with tip position placed on a fu;ed horizontal plane are modeled by an approach similar to the finite element method. Based on this model, the constraint force on the horizontal plane can be directly estimated from the motor's angle and the bending deflection, and thus the use of force sensor is no longer needed. The controller structure consists of two nested feedback loops in which the inner loop is designed for the motor's angle by a PD control algorithm and the outer loop deals with the constraint force by sliding-mode control. Experimental results are included to demonstrate the success of the developed controller.
Formation of mononuclear nitrido complexes of chromium(VI) and molybdenum(VI); Syntheses and X-ray crystal structures of N Cr(OBu(t))(3) and N Mo(OSiMe(3))(3)(py)
(1996-01-21)
Chiu, HT
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Chen, YP
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Chuang, SH
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Jen, JS
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Lee, GH
Mononuclear nitrido complexes of Cr and Mo, N=Cr(OBu(t))(3) and N=Mo(OSiMe(3))(3)(py), are synthesized; the chromium complex has an idealized C-3v symmetry while the molybdenum complex has a distorted square-pyramidal geometry with the nitrido ligand at apical position; the N-Cr distance is 1.538(5) Angstrom while the average N-Mo distance is 1.627 Angstrom.
Integral sliding control for disturbance matched to part of the inputs
(2000-03-01)
Chen, YP
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Chang, JL
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a theoretical research on the integral sliding control technology for linear time-invariant systems encountering disturbance matched to part of the control inputs. Only part of the control inputs is designed by the sliding-mode theory to eliminate the disturbance. Besides, based on the pole-assignment method the design of integral sliding vector becomes simple and straightforward. A numeric example is finally used to demonstrate the success of the developed controller.
N incorporation into InGaAs cap layer in InAs self-assembled quantum dots
(2005-12-01)
Chen, JF
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Hsiao, RS
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Hsieh, PC
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Chen, YJ
;
Chen, YP
This study presents the results of incorporating N into self-assembled InAs quantum dots (QDs) capped with an InGaAs cap layer. Experimental results indicate that such incorporation can redshift the QD ground state and decrease the energy spacing between the QD ground and first excited states. However, this incorporation reduces the potential barrier of the cap layer, increasing the electron escape from the QDs. Capacitance-voltage profiling shows that a broad shoulder corresponding to the electron emission from the QD ground to first-excited state cannot be resolved from the peak related to the electron emission from the excited states upon this incorporation. This finding implies that this incorporation reduces the energy spacing between the QD ground and first-excited states in the conduction band, thus correlating well with the photoluminescence data. In contrast, incorporating N directly into the InAs QD produces no redshift of the emission wavelength but introduces a deep trap at similar to 0.21 eV that depletes the electrons in the QDs. (c) 2005 American Institute of Physics.
Output feedback sliding-mode controller design for minimum phase linear systems
(2001-09-01)
Chen, YP
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Chang, JL
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Li, KT
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes an output sliding-mode control under three assumptions given to the system matrices and the matching uncertainty. Based on these assumptions', first one important transformation matrix is introduced and then a state-estimator is constructed. The-output sliding-mode control is designed when the system state is well estimated. Finally, a numeric example is included to demonstrate the developed controller.
Regulation and vibration control of an FEM-based single-link flexible arm using sliding-mode theory
(2001-07-01)
Chen, YP
;
Hsu, HT
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電控工程研究所
;
Institute of Electrical and Control Engineering
Compared to the assumed-mode method (AMM), the finite-element method (FEM) is not only more applicable to the modeling of various kinds of flexible structures but also better in estimating the natural frequencies. Motivated from these features and modified from the work of Yeung and Chen for an AMM-based model, the sliding-mode controller introduced in this paper is developed to deal with the regulation problem and vibration suppression of an FEM-based single-link flexible arm. This paper will focus on the issue of how to change the FEM-bascd model into a form similar to the AMM-based model via the Schur decomposition. A technique to measure the well-estimated state variables required for the control is also presented. Finally, numerical simulation results are given to verify the robustness of the modified sliding-mode controller against payload variation.
Stability analysis and bang-bang sliding control of a class of single-input bilinear systems
(2000-11-01)
Chen, YP
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Chang, JL
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Lai, KM
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper introduces a novel bang-bang sliding control of a class of single-input bilinear systems. The sliding function is chosen via the well-known pole-assignment method for linear time-invariant systems. Importantly, the bang-bang sliding control generates a reaching-and-sliding region and a stable-sliding region, each expressed by a set of linear inequalities. Both regions comprise the equilibrium point, shown to be asymptotically stable. However, the stability analysis is processed under the limitation that the system state should be initially located in the reaching-and-sliding region. Two numeric examples are used for demonstration.
Stability analysis and bounded sliding-mode control of a class of multi-input bilinear systems
(1999-12-01)
Chen, YP
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Chang, JL
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Lai, KM
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電控工程研究所
;
Institute of Electrical and Control Engineering
A bounded sliding-mode controller is developed for a class of multi-input bilinear systems. The sliding vector design is based on the conventional pole-assignment method for linear time-invariant systems. Three conditions are required for the assigned eigenvalues when applying the pole-assignment method. A potential reaching-and-sliding region and a stable sliding region are determined around the origin, which is shown to be locally asymptotically stable. Numeric simulation results are used to demonstrate the success of the proposed bounded sliding-mode controller.
Strain relaxation in InAs/InGaAs quantum dots investigated by photoluminescence and capacitance-voltage profiling
(2005-10-03)
Chen, JF
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Hsiao, RS
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Chen, YP
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Wang, JS
;
Chi, JY
We present detailed studies of the onset of strain relaxation in InAs/InGaAs quantum dots. We show that the ground-state photoluminescence (PL) emission redshifts with increasing the InAs coverage before relaxation and blueshifts when relaxation occurs. PL spectra of the relaxed samples show two predominant families of dots with very different temperature-dependent efficiency. By comparison we show that the dots emitting at long wavelength are degraded by relaxation while the dots emitting at short wavelength remain coherently strained. Consequently, the PL spectra are dominated by the dots emitting at short wavelength, leading to the observed blueshift. This result suggests that the relaxation does not occur uniformly. In addition, we show that the relaxation occurs in the dot bottom interface. (C) 2005 American Institute of Physics.
Vertex and tree arboricities of graphs
(2004-09-01)
Chang, GJ
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Chen, CY
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Chen, YP
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應用數學系
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Department of Applied Mathematics
This paper studies the following variations of arboricity of graphs. The vertex ( respectively, tree) arboricity of a graph G is the minimum number va( G) ( respectively, ta( G)) of subsets into which the vertices of G can be partitioned so that each subset induces a forest ( respectively, tree). This paper studies the vertex and the tree arboricities on various classes of graphs for exact values, algorithms, bounds, hamiltonicity and NP-completeness. The graphs investigated in this paper include block-cactus graphs, series-parallel graphs, cographs and planar graphs.