Two types of software were developed in this study. The first one predicted dynamic behavior of a complex crystallizer and was used to analyze the instability of the crystallizer and to investigate the manipulated and...
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Two types of software were developed in this study. The first one predicted dynamic behavior of a complex crystallizer and was used to analyze the instability of the crystallizer and to investigate the manipulated and controlled variables for eliminating the sustained limit-cycle of CSD. The other one was an implicit self-tuning real time control program which can be used for an industrial crystallizer. data from the pilot scale indicated that this program used for set point control of parameters was available. It will be satisfactory to use this program for control of CSD stability via tests of computer simulation.
Optimistic Concurrency control-OCC schemes based on certification are analyzed in this paper. We allow two types of data access schemes referred to as static and dynamic. According to the first (second) scheme a trans...
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This paper discusses the application of Kalman filtering technique in chemical processes, using an industrial polymerization reaction as an example. The mathematical model of the system has been developed through mech...
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This paper discusses the application of Kalman filtering technique in chemical processes, using an industrial polymerization reaction as an example. The mathematical model of the system has been developed through mechanism analysis, and the model accuracy has been verified by simulation. Based upon the principle of the extended Kalman filtering a state estimator has been constructed and an off-line state estimation with the data acquired from the production process has been performed. With this estimator, not only the state values of the reactor at any moment can be obtained but also the quality index of polymerized product - mean molecular weight and molecular Chain distribution can be estimated. It will be very advantageous to direct and supervise the technical process in off-line fashion.
The computer control system on the USSteel Gary Works' five-stand cold reduction mill utilizes a hierarchical, distributed structure. Strip thickness, mill speed, strip tension and screw position regulators operat...
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The computer control system on the USSteel Gary Works' five-stand cold reduction mill utilizes a hierarchical, distributed structure. Strip thickness, mill speed, strip tension and screw position regulators operate as conventional first level, closed loop controls during rolling. Higher level systems use technical models to calculate presets for mill speed, strip tension, screw position and thickness gage set points and for sequencing product through the mill. Coil to coil model adaptation, based on mill operating data, is used to update roll force, horsepower and screw position calculations for short-term performance improvement. Long-term adaptation updates yield strength for various steel grades and rolling lubricity constants used in the model. The computer system also provides an extensive data base for analysis and supervision of mill performance.
The author addresses the process and techniques of data collection in the field combat simulation with particular attention to data requirements, operational environments, surrogates, and instrumentation. In force-on-...
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ISBN:
(纸本)0911801073
The author addresses the process and techniques of data collection in the field combat simulation with particular attention to data requirements, operational environments, surrogates, and instrumentation. In force-on-force field experiments, soldiers engage in simulated combat with representative opposition forces. Computers and instrumentation are used for real-time casualty assessment and automatic recording of the results of engagements. Nonlethal surrogates of future weapon systems have been developed and utilized to bring realism to the experiment. A multicomputer system is used to control the simulated battle. It consists of a mainframe central processing unit and 16 minicomputers in four stems. Four basic types of instrumentation have been developed to assist data collection in field combat simulation. A position location system keeps track of the location of all players. A timing system tags all events with accurate time for comparative analysis. Sensor systems are used to detect the occurrence of an event, and a data collection system is used to store all the telemetered data. Analyzed data are then provided to other Army agencies responsible for computer modeling, war-gaming, or procurement decisions.
The traditional use of a design rule checker (DRC) ensures that the layout of an integrated circuit conforms to a set of tolerences known as design rules. Integrated circuit manufacturing yields are enhanced if these ...
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The traditional use of a design rule checker (DRC) ensures that the layout of an integrated circuit conforms to a set of tolerences known as design rules. Integrated circuit manufacturing yields are enhanced if these tolerences are not violated. In contrast to tolerence checking, yield analysis concerns itself with "yield sensitive elements" such as number of devices, total areas and total length of lines. The cumulative distributions of the elements can be used in yield analysismodeling. In addition, the value distribution of each element can be used to model the processing effort required for yielding a design. A software system known as YIELD is essential for extracting the required statistical data from the graphical data base.
Three-dimensional (3D) computer modeling and its associated data bases have been used in the power industry for a number of years for piping stress analysis, materials control, and interference detection. Traditionall...
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Three-dimensional (3D) computer modeling and its associated data bases have been used in the power industry for a number of years for piping stress analysis, materials control, and interference detection. Traditionally, such applications have analyzed or processed an existing design configuration. That is, the design configuration is manually developed and then supplied as input to the modeling and analysis software. In contrast, the system of 3D modeling software described allows the design configuration to be created interactively. The resulting geometric data base integrates all of the related functions that process the physical design data.
作者：
Tikvart, Joseph A.Cox, William M.US EPA
Monitoring & Data Analysis Div Research Triangle Park NC USA US EPA Monitoring & Data Analysis Div Research Triangle Park NC USA
Air quality modeling is an important component in the regulatory decision-making process for pollution control. Accordingly, regulators need to know how accurately a model estimates pollutant concentrations, and model...
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Air quality modeling is an important component in the regulatory decision-making process for pollution control. Accordingly, regulators need to know how accurately a model estimates pollutant concentrations, and modelers need a yardstick to evaluate and compare the performance of alternative models. With the availability of high quality data bases and consensus recommendations on a uniform set of statistical performance measures, it has been possible for the Environmental Protection Agency (EPA) to initiate a systematic model evaluation program. This paper summarizes progress made in that program.
The study of the dependence between successive discharges is the key factor towards better understanding of the complex and random nature of EDM. data dependent systems (DDS) which addresses such dependence are applie...
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The study of the dependence between successive discharges is the key factor towards better understanding of the complex and random nature of EDM. data dependent systems (DDS) which addresses such dependence are applied to model and analyze the EDM process. The DDS model of an EDM surface provides an exponential crater which upon integration with the classical thermal model and empirical evidence yields expressions for erosion rate and surface integrity. The DDS modeling of pulse voltage/current signals provide a measure of gap conditions. The damping ratio associated with a discriminating frequency (32 KH//z) is small for arcing. An analysis relating the damping ratio with characteristics of a pulse provide the information required for control.
Defensive Technology Studies have identified several concepts for interceptors which will counter the threat of hostile reentry vehicles. Hypersonic interceptors operating in the sensible atmosphere are one of the mor...
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Defensive Technology Studies have identified several concepts for interceptors which will counter the threat of hostile reentry vehicles. Hypersonic interceptors operating in the sensible atmosphere are one of the more promising near-term options. In such a system, thermal protection of missile’s control systems and the dynamic response of the airframe are key development issues. Jet Interaction control Systems provide viable solutions to both concerns. Aerojet is currently validating the capabilities of JI control Systems for the Army’s Ballistic Missile Defense Systems Command. This program has demonstrated the transient and frequency response of pitch, yaw, and roll control thrusters which have exhibited response, thrust modulation, and durability characteristics needed for hypersonic missiles. All design and development efforts were guided by analytical simulations of the response and dynamics of key components and the entire control system. The technology program was structured to address specific control requirements which were determined by detailed missile engagement computer simulations performed by McDonnell Douglas Astronautics Company, the Prime contractor. An integral part of these simulations was the synthesis of the control thruster dynamic behavior to a given command. Because of this dynamic response requirement and the attendant need to structure the design selection process, a detailed, mechanistic, twelve-degree-of-freedom engine response computer model was created. This model was utilized for the simulation, design, and test dataanalysis of the control thrusters. A fluid dynamics computer model was also established to mechanistically model the dynamic behavior of the pressurization, propellant tankage, and propellant distribution subsystems which are critical to the capabilities of the control engines. This model determines the activation time of the entire system to the first command and was used to evaluate the interactions of the propulsion s
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