There are lots of physical changes and chemical reactions in the processes of iron and steel making, these processes are quite complex in the aspect of heat *** processes of iron and steel making can be approximately ...
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There are lots of physical changes and chemical reactions in the processes of iron and steel making, these processes are quite complex in the aspect of heat *** processes of iron and steel making can be approximately divided into three *** first kinds are the processes of fusion metallurgy which involve enormous chemical reactions,such as blast furnace,converter,electric furnace and coke *** second kinds are the processes of heating and cooling which are mainly the physical changes,such as walking-beam reheating furnace,annular heating furnace and car-type *** third kinds are the processes of heat treatment which mainly adjust metallurgical structure of metal,such as roller hearth heat treatment furnace, strip continuous heat treatment vertical/horizontal furnace and HPH bell-type annealing *** process can only be finished in particular thermal *** all the physical and chemical processes mentioned above must obey first principles of engineering thermodynamics,heat & mass transfer,hydromechanics, combustion,metallurgy physical chemistry etc,and which can be summarized as principle of heat transfer,mass transfer,momentum transfer and chemistry *** this paper,based on first principle of heat and mass transfer in iron and steel making processes,a series of mathematical models of thermal equipments and processes are *** as the model of hot-blast stoves,coke oven,CDQ-boiler system,sintering, reheating furnace,soaking furnace,annular heating furnace,roller hearth heat treatment furnace,strip continuous heat treatment vertical/horizontal furnace,HPH bell-type annealing furnace,control cooling of medium plate,burner,heat exchanger and regenerative burner *** on-line application of the model is based on experimental certification of the mathematical *** finally the computer optimization system of metallurgical thermal process is obtained.
This article presents a heuristic algorithm for motion planning of a short range 7-DOF Laser Scanning System consisting of a 6-DOF vertical robot arm and a rotary table holding the workpiece. The redundancy of the mec...
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This article presents a heuristic algorithm for motion planning of a short range 7-DOF Laser Scanning System consisting of a 6-DOF vertical robot arm and a rotary table holding the workpiece. The redundancy of the mechanism is exploited for specifying certain constraints such as imposing a smooth motion of the rotary table while respecting the acceleration and speed limits and avoiding undesirable configurations of the robot arm such as the kinematic singularities, out-of-range conditions and collisions between the mechanical elements of the system (robot, table, workpiece and laser probe). The paper also presents the control system of the rotary table, and a communication protocol which allows the integration of the above-mentioned planning algorithm into the 3D scanning system.
Cutting process design includes the construction of cutting plan and finding of optimal trajectory for cutting tool moving. The first problem is known as cutting-and-packing one. The most significant results are recei...
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Cutting process design includes the construction of cutting plan and finding of optimal trajectory for cutting tool moving. The first problem is known as cutting-and-packing one. The most significant results are received for the problem of rectangular cutting-and-packing. The problem of finding the optimal cutting tool moving trajectory is formalized as problem of constructing the Eulerian cover with ordered enclosing. In the given research the composition of both problems to common system of cutting process design is considered.
There is discussed the problem of finding an equilibrium position in von Neumann's model ( A, B ) under exact and interval settings. Effective numerical methods of finding equilibrium exact von Neumann's model...
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There is discussed the problem of finding an equilibrium position in von Neumann's model ( A, B ) under exact and interval settings. Effective numerical methods of finding equilibrium exact von Neumann's model are presented. This methods can be stably implemented with floating-point arithmetic. The proposed methods are based on reducing the problem to solving the corresponding matrix games. Considering interval von Neumann's model, in case of multiplicative uncertainty both primal and dual von Neumann's rays are obtained by point von Neumann's model with matrices of interval centers. Interval of the Frobenius number in case of interval von Neumann's model are obtained by finding equilibrium for two exact von Neumann's models with point matrices of interval upper and lower bounds.
The feasibility of the large-scale production of a remarkable family of nanomaterials, denoted by fullerenes, is of vital importance for many scientific areas and is currently a challenging task. In this paper, a basi...
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ISBN:
(纸本)0780388089
The feasibility of the large-scale production of a remarkable family of nanomaterials, denoted by fullerenes, is of vital importance for many scientific areas and is currently a challenging task. In this paper, a basic concept of the control system of fullerene synthesis by lasers is proposed. The designed algorithm links fullerene yield and production rate to laser characteristics. To consider the possibility of realizing the more efficient production of selective fullerenes such as Go, expert knowledge on possible plasma regions within which fullerenes are synthesizing is suggested to determine the necessary local conditions for fullerene formation. The inverse control strategy based upon a structured neural network is employed to acquire and represent the knowledge, that is, the ultrafast and highly complex dynamics of processes evolving at the very short time-scale (10(-6)-10(-8) s) in the laser-produced plasma. The optimized plasma zones providing a C-60 yield of 70% and production rate of 5.14 g/min (P-He = 240 Torr, power density = 7 x 10(9) W cm(2) T = 2700 K) from a graphite target are identified and displayed as time-dependent response.
A model-based framework for advanced optimal operation of copolymerization processes was developed and tested experimentally in conjunction with a distributed control system (DCS) suitable for industrial application. ...
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A model-based framework for advanced optimal operation of copolymerization processes was developed and tested experimentally in conjunction with a distributed control system (DCS) suitable for industrial application. A test case of emulsion copolymerization of styrene (Sty) and methyl-methacrylate (MMA) was investigated for predicting and optimizing key product properties including molecular weight distribution (MWD), particle size distribution (PSD), copolymer composition and conversion. The model equations include diffusion-controlled kinetics at high monomer conversions, where transition from a 'zero-one' to a 'pseudo-bulk' regime occurs. The reactor mass and energy balances describe the system transients for batch and semi-batch operations. Population balance equations, describe the particle evolution and comprise sets of integro-partial differential and nonlinear algebraic equations. The models were solved using an efficient numerical scheme suitable for on-line monitoring and control. The model predictions were found to be in good agreement with experimental results for measurements carried out with variable monomer feed rates, variable temperature and variable composition of styrene-MMA, from 25/75 to 75/25 proportions. The manipulation of these variables was found to affect the PSD significantly. The experimental results confirmed the accuracy of our optimization scheme for the desired conversion, MWD and PSD. (c) 2005 Elsevier Ltd. All rights reserved.
We present a distributed cross layer approach to controlling network performance under various QoS requirements in interference limited systems. The interaction between different layers of the OSI protocol stack requi...
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ISBN:
(纸本)0780385330
We present a distributed cross layer approach to controlling network performance under various QoS requirements in interference limited systems. The interaction between different layers of the OSI protocol stack requires a cross layer approach in order to optimally allocate the resources of the network. The Message Passing Direct Step Method presented here is an adaptive and distributed algorithm that achieves maximum network performance. Using the forward and backwards networks,. this algorithm finds the left and right Perron Frobenius eigenvectors for the system and automatically adjusts the operating point of the system (data rates, link rates and transmitter powers) to their optimal values while satisfying QoS constraints. The approach is developed and simulated using TCP Reno.
This paper describes a new adaptive algorithm that smoothly and dynamically adjusts the system resources of link rates and transmitter powers to maximize the performance of the system. Performance is explicitly measur...
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ISBN:
(纸本)0780379543
This paper describes a new adaptive algorithm that smoothly and dynamically adjusts the system resources of link rates and transmitter powers to maximize the performance of the system. Performance is explicitly measured from the point of view of traffic carried by the network. Transmitter powers are subsumed in the feasible rate region for the wireless network, and are not directly involved in evaluating the network. A new adaptive algorithm, DSM, is presented. DSM seeks optimal system performance by greedily searching the rate region surface seeking link rates that best meet QoS and user demand needs and then calculates transmitter powers to support these rates. If system requirements such as the number of users or their QoS change, the DSM adapts by again exploring the now changed rate region. Changes in the wireless environment are addressed by the algorithm in a similar fashion.
Downstream-bioprocess operations, for example, selective flocculation, are inherently variable due to fluctuations in feed material, equipment performance, and quality of additives such as flocculating agents. Due to ...
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Downstream-bioprocess operations, for example, selective flocculation, are inherently variable due to fluctuations in feed material, equipment performance, and quality of additives such as flocculating agents. Due to these fluctuations in operating conditions, some form of process control is essential for reproducible and satisfactory process performance and hence, product quality. Both product (alcohol dehydrogenase) and key contaminants (RNA, protein, cell debris) within a Saccharomyces cerevisiae system were monitored in real-time adopting an at-line enzymatic reaction and rapid UV-VIS spectral-analysis technique every 135 seconds. The realtime measurements were implemented within two control configurations to regulate the batch-flocculation process according to prespecified control objectives, using the flocculant dose as the sole manipulative variable. An adaptive, model-based control arrangement was studied, which combined the rapid measurements with a process model and two model parameter-identification techniques for real-time prediction of process behavior. Based on an up-to-date mathematical description of the flocculation system, process optimization was attained and subsequent feedback control to this optimum operating set point was reproducibly demonstrated with a 92% accuracy. A simpler control configuration was also investigated adopting the cell debris concentration as the control variable. Both control arrangements resulted in superior flocculation-process performances in terms of contaminant removal, product recovery, and excess flocculant usage compared to an uncontrolled system. (C) 2000 John Wiley & Sons, Inc.
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