We propose a methodology of genetic algorithms (GAs) for the rules searching of model reference fuzzy adaptive control system (MRFACS). We choose a second order reference model as an ideal output, then adjust the prop...
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We propose a methodology of genetic algorithms (GAs) for the rules searching of model reference fuzzy adaptive control system (MRFACS). We choose a second order reference model as an ideal output, then adjust the proportional sensitivity by using fuzzy adaptive controller to make the plant's output follows the reference signal. We apply modified GAs for rules searching because that the rules set constructed by cut and try works unsatisfactory. In our study, we offer two types of fuzzy controllers (one is constructed with state error /spl epsi/ & change rate of error /spl Delta//spl epsi/ and the other is constructed with state error /spl epsi/ & plant output y/sub p/). the conclusions we get from simulation results are: (1) Modified GAs can find population with higher fitness values since it select better populations by multiple-point crossover and multiple-point mutation, (2) Fuzzy controller with /spl epsi/ and y/sub p/ shows higher performance indices than that with /spl epsi/& /spl Delta//spl epsi/ for the reason that the front controller can avoid using same rules for different time delay constants, and (3) system remains controllable when the time delay constants exceed the expected margin, it proves that our fuzzy controller contains the characteristic of robustness.< >
It is now well established that the properties of films grown by chemical vapour deposition are strongly determined by the interaction of transport phenomena and homogeneous and heterogeneous chemical reactions in the...
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It is now well established that the properties of films grown by chemical vapour deposition are strongly determined by the interaction of transport phenomena and homogeneous and heterogeneous chemical reactions in the reactor. the main objective of the modelling work presented is to relate deposition performance (deposition rate and uniformity, film composition and selectivity) to reactor geometry and process conditions (pressure, temperature, reactant concentrations and gas flow rate). Owing to the lack of kinetic data, the joint use of thermodynamic databases, thermochemical equilibrium modelling and transport phenomena modelling could be an original way to offset partially the incomplete knowledge of chemical kinetics. this coupled approach is restricted to equilibrium conditions (high temperature and/or high deposition pressure). A description is given for test cases of how thermochemical and mass transport simulations can help advances in materials and process engineering.
the proceedings contain 46 papers. the topics discussed include: 2-D shape blending: an intrinsic solution to the vertex path problem;pad an alternative approach to the computer interface;implementing rotation matrix ...
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ISBN:
(纸本)0897916018
the proceedings contain 46 papers. the topics discussed include: 2-D shape blending: an intrinsic solution to the vertex path problem;pad an alternative approach to the computer interface;implementing rotation matrix constraints in analog VLSI;interactive texture mapping;correcting for short-range spatial non-linearities of CRT-based output devices;efficient, fair interpolation using Catmull-Clark surfaces;mesh optimization;graphics rendering architecture for a high performance desktop workstation;realityengine graphics;an interactive 3D toolkit for constructing 3D widgets;toolglass and magic lenses: the see-through interface;LEO: a system for cost effective 3D shaded graphics;EXACT: algorithm and hardware architecture for an improved a-buffer;autocalibration for virtual environments tracking hardware;VIEW - an exploratory molecular visualization system with user-definable interaction sequences;and surround-screen projection-based virtual reality: the design and implementation of the CAVE.
As part of a decision support system, Manitoba Hydro implemented a comprehensive optimization model for operations planning in the mid 1980's (Barritt-Flatt and Cormie 1991). Since that time the model has been use...
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ISBN:
(纸本)0872629120
As part of a decision support system, Manitoba Hydro implemented a comprehensive optimization model for operations planning in the mid 1980's (Barritt-Flatt and Cormie 1991). Since that time the model has been used on an ongoing basis for scheduling of generation from Manitoba Hydro's two thermal generating stations, eleven hydro generating stations and reservoir system. During this period the system has experienced severe drought, floods in particular basins, and major forced outages of generating equipment. throughout these events, the optimization model has been used to provide effective strategies for managing the operation of the system.
this paper describes an object-oriented approach to river basin simulation modelingthat is event driven rather than time driven as in most river system simulation models. At the heart of this method are autonomous so...
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ISBN:
(纸本)0872629120
this paper describes an object-oriented approach to river basin simulation modelingthat is event driven rather than time driven as in most river system simulation models. At the heart of this method are autonomous software objects which replicate the physical behavior of the components of an actual river system. these objects react to stimuli (changing values of their inputs, outputs or state) in much the same way as do the analogous components. the simulation of river systems is the result of the coordinated simulations in any order, of the various objects within the system. An object-oriented approach to modeling a river has a number characteristics that make it worthy of consideration. the model's architecture makes it especially suited to graphic user interfaces and database operations. It allows the easy integration of artificial intelligence techniques that can aid in expressing complex policies governing system operation.
During the drought of 1988, water users in the Kanawha River, West Virginia, became painfully aware of conflicting uses that have developed since the 1970s. A numerical modeling of the Kanawha River was conducted to e...
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ISBN:
(纸本)0872629120
During the drought of 1988, water users in the Kanawha River, West Virginia, became painfully aware of conflicting uses that have developed since the 1970s. A numerical modeling of the Kanawha River was conducted to evaluate the effects of different operation scenarios on river users - including water quality flows. the model was created withthe object-oriented programming language, STELLA. the model includes user-developed Boolean statements to create an expert system. STELLA, using the expert system, was able to accurately reproduce the water management decisions and river flow for 1988 which included flood releases, minimum flows, lake storage balances, and downstream water quality targets.
Many existing solute transport codes rely on the assumption of steady (i.e. time-invariant) flow. this assumption severely limits such models, as accurate simulations often require realistic descriptions of the hydrau...
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ISBN:
(纸本)0872629120
Many existing solute transport codes rely on the assumption of steady (i.e. time-invariant) flow. this assumption severely limits such models, as accurate simulations often require realistic descriptions of the hydraulic flow regime. Small mountain streams, for example, are known to undergo daily fluctuations in volumetric flow rate and groundwater inflow. these changes in flow may act to dilute or concentrate a given solute, thereby affecting a contaminant's ultimate concentration. In response to this shortcoming, a solute transport model is presented that allows for the specification of time-varying lateral inflows, in-stream flow rates, and cross-sectional areas. this allows the model to be used in conjunction with watershed-scale hydraulic routing models that provide the time-varying parameters. this linkage between the routing component and the solute transport model is greatly facilitated through the use of the Modular modelingsystem (MMS). MMS allows the two components to be represented as separate modules that are called at each time step. For a given time step, the routing module computes the flows and cross-sectional areas. these values are then made available to the solute transport module, and a new time step is initiated.
the Water Supply Citizens Advisory Committee (WSCAC) is a unique citizens group. Although it is funded by the Massachusetts Water Resources Authority (MWRA), it has a paid staff who are independent of the agency, and ...
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ISBN:
(纸本)0872629120
the Water Supply Citizens Advisory Committee (WSCAC) is a unique citizens group. Although it is funded by the Massachusetts Water Resources Authority (MWRA), it has a paid staff who are independent of the agency, and report only to the Committee. WSCAC was initially organized in 1978 to provide citizen oversight for a proposed large river diversion project. the committee was instrumental in demonstrating that demand management and system repair could meet the projected needs for the planning period. WSCAC presently acts in an advisory capacity to the MWRA Board of Directors and staff on water supply policy and programs. For over a decade WSCAC has provided information and advice to the public, legislators, and state agencies. the Committee has a major impact on state water policy, water management activities, and the passage of major legislation. During the past year WSCAC has participated with MWRA staff in the U.S. Army Corps of Engineers National Study of Water Management During Drought. As part of this effort, WSCAC has assisted withsystem simulation modeling, development of system performance criteria, evaluation of alternative management strategies, and 'trigger planning.' this paper will describe the makeup and functioning of WSCAC and our role in this study.
this paper presents an overview of an external state management systemthat has been designed and developed as part of Jade's implementation of Time Warp. the saving of state information can be a serious overhead ...
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ISBN:
(纸本)078031381X
this paper presents an overview of an external state management systemthat has been designed and developed as part of Jade's implementation of Time Warp. the saving of state information can be a serious overhead for optimistic synchronization mechanisms. this can become particularly relevant on the critical path of a parallel simulation. One optimization possible when processes have large states is to limit state saving to those parts that change at a given event. A backtrail of state changes is maintained instead of making full state copies to support rollback. An approach to this optimization, called demand state saving (DSS) has been implemented within Jade's external state management system (ESM). ESM enables building custom state managers, such as DSS, for different types of state information. these state managers reside outside of the Time Warp executive making it easier to develop and utilize alternative state management schemes. Both ESM and DSS are described in this paper. A rough analysis that compares DSS with copy state saving suggests that in the worst case, DSS will be superior when the fraction of state modified at an event is less than 20% of the total state.
Previously, we had developed the concept of a Segmental Neural Net (SNN) for phonetic modeling in continuous speech recognition (CSR). this kind of neural network technology advanced the state-of-the-art of large-voca...
Previously, we had developed the concept of a Segmental Neural Net (SNN) for phonetic modeling in continuous speech recognition (CSR). this kind of neural network technology advanced the state-of-the-art of large-vocabulary CSR, which employs Hidden Markov Models (HMM), for the ARPA 1000-word Resource Management corpus. More Recently, we started porting the neural net system to a larger, more challenging corpus - the ARPA 20,000-word Wall Street Journal (WSJ) corpus. During the porting, we explored the following research directions to refine the system: i) training context-dependent models with a regularization method; ii) training SNN with projection pursuit; and ii) combining different models into a hybrid system. When tested on both a development set and an independent test set, the resulting neural net system alone yielded a performance at the level of the HMM system, and the hybrid SNN/HMM system achieved a consistent 10-15% word error reduction over the HMM system. this paper describes our hybrid system, with emphasis on the optimization methods employed.
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