Interactive grammar based design systems (IGBDS) are capable of generating large numbers of alternative designs. Prior to the application of IGBDS, a set of rules should be defined based on the theoretical theories an...
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ISBN:
(纸本)9781424406838
Interactive grammar based design systems (IGBDS) are capable of generating large numbers of alternative designs. Prior to the application of IGBDS, a set of rules should be defined based on the theoretical theories and practical experiences in designing the objects, or by analysing the existing sets of objects. However, due to the time constraints in developing theoretical theories, gaining the practical skills of experts is of qualitative in nature and stylistically inconsistent designs to be analysed, it is difficult to systematically derive a set of shape grammar rules in generating designs which fulfil specific requirements. To address this problem, this paper presents an IGBDS enhanced by evolutionary computing to evolve a set of grammar rules for product form design. In this research, the forms of a product are analysed to derive shape features in the form of shape grammar (SG) rules. the rules are then encoded as the code scripts of a genetic algorithm (GA) representation in order to generate new shape grammar rules. the parameters in GA representation are modified by genetic programming (GP) which is regulated by control planning strategies named "GP-GA-SG". the "GP-GA-SG" control planning strategy first defines ways on how the control variables in GP should modify the variables in GA representation. the "GP-GA-SG" control planning strategy then defines ways on how the control variables in GA should modify the variables in SG representation. the SG rules modified by the GA variables define a new combination of shape features for alternative designs. In this way, traditional shape grammar is extended to an interactive context in which generative and evolutionary computing methods are combined. Both product component design as well as product configuration are supported in this framework. In this paper, we describe how this framework is formulated and discuss its potentials in supporting product design, with initial examples showing how the system is intended
Based on interpolation formula or curve fitting and under special relating angle limitation, maximum contingency clearing time to be target function, all swing equations in power system will be converted into numerica...
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ISBN:
(纸本)0863412467
Based on interpolation formula or curve fitting and under special relating angle limitation, maximum contingency clearing time to be target function, all swing equations in power system will be converted into numerical equivalent algebraic equations by using the implicit trapezoidal rule and are involved in equality constrains set. All rotors' angles related to COI are used to be inequality constrains. this paper presents a novel nonlinear programming model that can calculate maximum contingency clearing time accurately. An interior point algorithm for solving the proposed model is derived. Proposed model and algorithm don't have to research or derive a lot of complex theory and mathematics formulas, possess significant simplifying structure, excellent convergence property and can be implement or program easily. Based on time domain emulating and numerical calculation completely, proposed model and algorithm are suitable for any generator and load modules very well.
Preventive control or remedial actions should be taken if dynamic instability for a contingency is detected. Generation rescheduling is an effective means to enhance security of power systems. A novel methodology, bas...
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ISBN:
(纸本)0863412467
Preventive control or remedial actions should be taken if dynamic instability for a contingency is detected. Generation rescheduling is an effective means to enhance security of power systems. A novel methodology, based on semi-infinite programming (SIP) techniques, is presented here for dynamic security- constrained generation rescheduling. Generation rescheduling is modeled as an OPF-like problem with dynamic security constraints for credible contingencies. the OPF problem is, mathematically, a SIP problem with infinite-dimensional constraints representing transient stability limits. Local reduction based on infinite norm of the violated constraints is proposed to replace the infinite constraints with finite constraints and makes the SIP problem solvable for finite standard programming method. Case study on the New England 39-bus system showed that the proposed model and approach is practical and effective.
Load shedding is a simple but effective emergency control strategy when the system loses transient voltage stability after a heavy disturbance. Systematic algorithm and its realization for the optimal load shedding co...
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ISBN:
(纸本)0863412467
Load shedding is a simple but effective emergency control strategy when the system loses transient voltage stability after a heavy disturbance. Systematic algorithm and its realization for the optimal load shedding control laws are studied using optimal control theory. the basic principle of the algorithm is to transform the optimal control into a mathematical programming problem by calculating the gradient of both objective function and constraint functions, and then, solve it by successive quadratic programming method. Compared with trial and error method, the proposed algorithm can not only greatly reduce the computation time but also save the control cost and improve the control accuracy, so that off-line calculation and on-line control strategy decision is easy to apply. Results show the good convergence property and short computation time of the algorithm.
the hierarchical voltage control has been utilized and proved as an effective method in some power systems. the secondary voltage control provides voltage support to an area of the transmission network. there are seve...
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ISBN:
(纸本)0863412467
the hierarchical voltage control has been utilized and proved as an effective method in some power systems. the secondary voltage control provides voltage support to an area of the transmission network. there are several control objectives should be considered in the secondary voltage control and some objectives and constraints have accepted tolerance dealt with by fuzzification. therefore, a secondary voltage control method based on fuzzy multi-objective mixed integer linear programming is proposed in this paper. To incorporate tolerance of the objectives, the fuzzy goals are adopted, and the fuzzy logic method is proposed in this paper for ranking the priority of each objective and defining the constraints of adjusting number of the shunt capacitor/reactor and OLTC transformer which are controlled in a coordinated way in a control zone. then this problem can be solved by fuzzy goal programming and some simulation results of secondary voltage control at Zouxian power plant demonstrated the feasibility of the method.
While there has been a great deal of research in face detection and recognition, there has been very limited work on identifying the expression on a face. Many current face detection methods use a Viola-Jones style &q...
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ISBN:
(纸本)0769525032
While there has been a great deal of research in face detection and recognition, there has been very limited work on identifying the expression on a face. Many current face detection methods use a Viola-Jones style "cascade" of Adaboost-based classifiers to detect faces. We demonstrate that faces with similar expression form "clusters" in a "classifier space" defined by the real-valued outcomes of these classifiers on the images and address the the task of using these classifiers to classify a new image into the appropriate cluster (expression). We formulate this as a Markov Decision Process and use dynamic programming to find an optimal policy-here a decision tree whose internal nodes each correspond to some classifier, whose arcs correspond to ranges of classifier values, and whose leaf nodes each correspond to a specific facial expression, augmented with a sequence of additional classifiers. We present empirical results that demonstrate that our system accurately determines the expression on a face during detection.
Due to a number of similarities between user-centred design (UCD) and agile development, coupled with an appreciation that developers are rarely usability experts, it seems attractive to integrate these two approaches...
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ISBN:
(纸本)3540350942
Due to a number of similarities between user-centred design (UCD) and agile development, coupled with an appreciation that developers are rarely usability experts, it seems attractive to integrate these two approaches. However, although agile methods share some of the same aims as UCD, there are also distinct differences. these differences have made the use of these methods on development projects problematic. this paper reports a field study designed to investigate the use of agile methods alongside UCD in one particular organization. the aim of the study was to develop a framework for use by project teams wishing to integrate UCD practices with agile development. the study, its findings and five principles for integrating UCD and agile development arising from this work are discussed.
Petri net (PN), as a kind of powerful modeling tool for discrete-event dynamic systems, has widely applied in many domains. In this paper, two classes of high-level PN, controlled colored Petri net and controlled hybr...
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ISBN:
(纸本)0863412467
Petri net (PN), as a kind of powerful modeling tool for discrete-event dynamic systems, has widely applied in many domains. In this paper, two classes of high-level PN, controlled colored Petri net and controlled hybrid Petri net, are proposed and applied in the unit-commitment (UC) problem for a regional power grid with pumped storage stations. At the same time, the principle of large-scale system decomposition-coordination is applied to solve the problem of optimizing system operation. As a result, the UC problem is further simplified, as well as the algorithm efficiency improved. the proposed solution based on the high-level PN models, dynamic programming and decomposition-coordination theory, provides a new modeling methodology and could result in a superior dispatch plan for a regional power grid.
Ink annotation is a common method for recording feedback on a paper document. However, reviewing code on paper is difficult due to its non-linear nature. this project extends existing research ideas to develop a digit...
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ISBN:
(纸本)1595934731
Ink annotation is a common method for recording feedback on a paper document. However, reviewing code on paper is difficult due to its non-linear nature. this project extends existing research ideas to develop a digital ink annotation tool within an Integrated Development Environment (IDE). the aim is to provide code reviewers with an effective tool for directly commenting on code within the IDE. We describe scenarios where ink annotation would provide benefits, along with requirements and our implementation of the Rich Code Annotation Tool (RCA). Copyright 2006 ACM.
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