Browsing by Author "Hsieh, SH"

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Genetic algorithm based fuzzy ID3 algorithm
(2004)
Chang, JY
;
Cho, CW
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Hsieh, SH
;
Chen, ST
;
電控工程研究所
In this paper, we propose a genetic algorithm (GA) based fuzzy ID3 algorithm to construct a fuzzy classification system with both high classification accuracy and compact rule base size. This goal is achieved by two key steps. First, we optimize by GA the parameters controlling the means and variances of fuzzy membership functions and leaf node conditions for tree construction. Second, we prune the rules of the tree constructed by evaluating the effectiveness of the rule, and the remaining rules are retrained by the same GA proposed. Our proposed scheme is tested on various famous data sets, and its results is compared with C4.5 and IRID3. Simulation result shows that our proposed scheme leads to not only better classification accuracy but also smaller size of rule base.
Gravity-type interactive Markov models .1. A programming formulation of steady states
(1997-11-01)
Smith, TE
;
Hsieh, SH
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
An important class of interactive Markov migration models is characterized by gravity-type transition kernels, in which migration flows in each time period are postulated to vary inversely with some symmetric measure of migration costs and directly with some population-dependent measure of attractiveness. This two-part study analyzes the uniqueness and stability properties of steady states for such processes. In this first part, it is shown that a flow version of the steady-state problem can be given a programming formulation which permits global analysis of steady-state behavior. Within this programming framework, it is shown that when attractiveness is diminished by increased population congestion, the steady states for such processes are unique. The second part of the study will employ these results to analyze the stability properties of such steady states.
Gravity-type interactive Markov models .2. Lyapunov stability of steady states
(1997-11-01)
Smith, TE
;
Hsieh, SH
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
In Part I of this paper (Smith and Hsieh, 1997) a programming formulation of steady states was developed for gravity-type interactive Markov chains in terms of their associated spatial-flow chains. These results are here applied to analyze the stability properties of interactive Markov chains. In particular, the objective function for this programming formulation is shown to constitute a Lyapunov function for an appropriately defined continuous-time version of spatial-flow chains. The Lyapunov stability properties of these spatial flows are then shown to yield corresponding stability properties for the continuous-time versions of interactive Markov chains. In particular, these processes always exhibit global convergence to steady states. Finally, it is shown that when steady states are unique, these convergence results are inherited by those interactive Markov chains that are 'sufficiently close' to their continuous-time versions.
The combined toxic effects of nonpolar narcotic chemicals to Pseudokirchneriella subcapitata
(2006-06-01)
Hsieh, SH
;
Tsai, KP
;
Chen, CY
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環境工程研究所
;
Institute of Environmental Engineering
This paper presents the toxicity data of 10 nonpolar narcotic chemicals on Pseudokirchneriella subcapitata (green algae) assessed by a new algal toxicity testing technique conducted under air-tight environment. Based on DO production, median effective concentration (EC50) varies from 1.73mg/L (1-octanol) to8040 mg/L (2-propanol). The endpoint of algal growth rate reveals similar sensitivity as that from DO production. Compared to literature data, Pseudokirchneriella subcapitata and Nitrosomonas are apparently more sensitive to nonpolar narcotics than other organisms such as minnow, daphnia, and Tetrahymena pyriformis. Furthermore, good correlations between toxic effects observed from Pseudokirchneriella subcapitata and other aquatic organisms were found. Hence, algal toxicity test can be considered as a surrogate test for estimating the toxicity of nonpolar chemicals to fathead minnow, Microtox, activated sludge, Daphina magna, and Tetrohymena pyriformis. The combined effects of 13 binary mixtures of nonpolar chemicals were investigated using both additive-index method and isobologram analysis. overall speaking, the joint actions between these chemicals are strictly additive. Model analyses indicate that these compounds act on identical reaction sites or receptors, which verify that these chemicals are of the same toxicity mechanism (narcosis). (c) 2006 Elsevier Ltd. All rights reserved.
The formation of perovskite PbTiO3 powders by sol-gel process
(2006-06-10)
Lee, CY
;
Tai, NH
;
Sheu, HS
;
Chiu, HT
;
Hsieh, SH
Nano-sized cubic Pb2Ti2O6 and monoclinic PbTi3O7 were obtained as the first stage products, by sol-gel process using anhydrous lead acetate and titanium(IV) isopropoxide as precursors; then, as the powder was heated, Pb2Ti2O6 gradually transformed to perovskite PbTiO3 around 673 K. (c) 2005 Elsevier B.V. All rights reserved.