The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Platea...The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.展开更多
Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distr...Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distribution in non-conservatively coupled osillators, equations of power balance and those for calculation of each concerned power flow and other power items are derived to develop SEA theory for non-conscrvativcly coupled systems. Results show that conservative coupling is only a special case of non-conservative coupling situations, effect of coupling damping on power flow and energy distribution in non-conservatively coupled systems arc not negligible unless coupling damping is much smaller compared with internal one. As an application of the theory, energy problems of non-conservatively coupled plates are studied theoretically and experimentally.展开更多
The purpose of this paper is to report on a new system-theoretic based methodology and corresponding model for Enterprise Architecture development.This model captures the essence of the strategic,conceptual,doctrinal ...The purpose of this paper is to report on a new system-theoretic based methodology and corresponding model for Enterprise Architecture development.This model captures the essence of the strategic,conceptual,doctrinal layer of the organization.Reusable Quality Technical Architectures(RQ-Tech)graphically reveals a comprehensive array of enterprise decision alternatives in easily understandable views;all while maintaining the hyperlinks to its provenance in strategic authoritative documentation.The RQ-Tech method has combined the practice of Enterprise Architectures with a modern perspective grounded in Systems Theory and the theory regarding the computer science-oriented Semantic Web.This recombination results in a distinctive methodology for developing models.This new methodology supports the conclusion that system-specific solutions produce islands of technology and can be prevented by employing better enterprise change planning.A review of the literature in three major areas illustrates the overlap common to all three domains.This review provides support for critical thinking concerning how to enrich the Enterprise Architecture practice.The research centered on finding the most significant factors to consider when translating the authoritative text and rich pictures that enterprise managers use to describe the strategic mission and vision of their complex,service-oriented enterprise into user-oriented semantic models.It provides the basis for RQ-Tech as a methodology that enables increased understanding of complex systems through use of Semantic Web standards.展开更多
When a feedback system has components described by non-rational transfer functions, a standard practice in designing such a system is to replace the non-rational functions with rational approximants and then carry out...When a feedback system has components described by non-rational transfer functions, a standard practice in designing such a system is to replace the non-rational functions with rational approximants and then carry out the design with the approximants by means of a method that copes with rational systems. In order to ensure that the design carried out with the approximants still provides satisfactory results for the original system, a criterion of approximation should be explicitly taken into account in the design formulation. This paper derives such a criterion for multi-input multi-output(MIMO) feedback systems whose design objective is to ensure that the absolute values of every error and every controller output components always stay within prescribed bounds whenever the inputs satisfy certain bounding conditions. The obtained criterion generalizes a known result which was derived for single-input single-output(SISO) systems; furthermore, for a given rational approximant matrix, it is expressed as a set of inequalities that can be solved in practice. Finally, a controller for a binary distillation column is designed by using the criterion in conjunction with the method of inequalities. The numerical results clearly demonstrate that the usefulness of the criterion in obtaining a design solution for the original system.展开更多
文摘The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.
文摘Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distribution in non-conservatively coupled osillators, equations of power balance and those for calculation of each concerned power flow and other power items are derived to develop SEA theory for non-conscrvativcly coupled systems. Results show that conservative coupling is only a special case of non-conservative coupling situations, effect of coupling damping on power flow and energy distribution in non-conservatively coupled systems arc not negligible unless coupling damping is much smaller compared with internal one. As an application of the theory, energy problems of non-conservatively coupled plates are studied theoretically and experimentally.
文摘The purpose of this paper is to report on a new system-theoretic based methodology and corresponding model for Enterprise Architecture development.This model captures the essence of the strategic,conceptual,doctrinal layer of the organization.Reusable Quality Technical Architectures(RQ-Tech)graphically reveals a comprehensive array of enterprise decision alternatives in easily understandable views;all while maintaining the hyperlinks to its provenance in strategic authoritative documentation.The RQ-Tech method has combined the practice of Enterprise Architectures with a modern perspective grounded in Systems Theory and the theory regarding the computer science-oriented Semantic Web.This recombination results in a distinctive methodology for developing models.This new methodology supports the conclusion that system-specific solutions produce islands of technology and can be prevented by employing better enterprise change planning.A review of the literature in three major areas illustrates the overlap common to all three domains.This review provides support for critical thinking concerning how to enrich the Enterprise Architecture practice.The research centered on finding the most significant factors to consider when translating the authoritative text and rich pictures that enterprise managers use to describe the strategic mission and vision of their complex,service-oriented enterprise into user-oriented semantic models.It provides the basis for RQ-Tech as a methodology that enables increased understanding of complex systems through use of Semantic Web standards.
基金financial support from the honour program of the Department of Electrical Engineering,Faculty of Engineering,Chulalongkorn University
文摘When a feedback system has components described by non-rational transfer functions, a standard practice in designing such a system is to replace the non-rational functions with rational approximants and then carry out the design with the approximants by means of a method that copes with rational systems. In order to ensure that the design carried out with the approximants still provides satisfactory results for the original system, a criterion of approximation should be explicitly taken into account in the design formulation. This paper derives such a criterion for multi-input multi-output(MIMO) feedback systems whose design objective is to ensure that the absolute values of every error and every controller output components always stay within prescribed bounds whenever the inputs satisfy certain bounding conditions. The obtained criterion generalizes a known result which was derived for single-input single-output(SISO) systems; furthermore, for a given rational approximant matrix, it is expressed as a set of inequalities that can be solved in practice. Finally, a controller for a binary distillation column is designed by using the criterion in conjunction with the method of inequalities. The numerical results clearly demonstrate that the usefulness of the criterion in obtaining a design solution for the original system.