Simulation and control of electrode position controllers for electric arc furnaces

A comparative study is made of the dynamic performance of the main types of electrode position controllers used with industrial arc furnaces, consisting essentially of direct actuators employing hydraulic servosystems and indirect actuators operating a winch system. The overall system models include single- and three-phase power system representations and are used for the design of existing conventional analogue controllers to give improved short-term dynamic performance. Direct digital control of the electrode position servomechanism, incorporating conventional four mode algorithms and also suboptimal control based on a reduced-order linear model for controlling a non-linear plant model, is investigated. The study illustrates that improved long- and short-term dynamic performance of electrode position can be obtained by improved control system design.     

An adaptive system for modelling and simulation of electrical arc furnaces

Modelling and simulator development for electric arc furnaces (EAFs) are of significant importance in designing control systems and in performance optimisation of EAFs. This paper presents a method based on adaptive neuro-fuzzy inference systems (ANFIS) for modelling and simulating EAFs with the focus on the regulator loop that is used for positioning the electrodes. The effectiveness of the simulator is shown through experiments by comparing the simulator outputs with actual plant data, using the EAF of Gerdau Ameristeel Whitby (GAW) in Ontario, Canada.     

调频连续波高度表的计算机仿真

介绍了使用SPW软件对调频连续波高度表进行计算机仿真的情况,包括高度表的工作原理、数学模型的建立和和性能仿真等内容,并给出了定性和定量的仿真结果.仿真主要针对噪声信道和理想信道,在VHF/UHF波段及S波段进行了模拟测高,结果表明工作频率对高度表的测高精度影响不大,但宽带调频高度衷具有更好的测高精度和更强的抗干扰能力.     

Computer simulation of barrier-island migration

Five depositional subenvironments are commonly recognized in barrier island complexes: lower shoreface, middle shoreface, beach-upper shoreface, eolian, and lagoon. Facies belonging to these subenvironments can be characterized in terms of primary structures and sediment attributes. The facies assemblages which occur in the geologic record differ according to strandline still-stand, transgression, or regression and rates of basin subsidence. A FORTRAN program was developed to produce graphic output to aid in understanding facies relationships produced by these controlling parameters.     

Computer system simulation in Pascal

The programming language Pascal is considered as one of the most interesting computer system simulation tools. This paper discusses design facilities required in simulation languages, making use of a model described in Pascal. An important area is seen to be that of queues, lists or sets, and the facilities that are powerful yet simple to use are stressed. The problem of parallelism and synchronization in a simulator is solved. The structure of the simulator is considered.     

Computer simulation in introductory geology

Computer simulations of geologic processes are part of the regular laboratory fare in beginning geology courses at Syracuse University. Three programs used regularly are: (1) META, which accepts as input the modal analysis of a sedimentary rock, then calculates mineral assemblages that would result at specified grades of metamorphism, (2) LAKES, with which the student can follow changes in vertical thermal structure of a lake as weather conditions are varied through time, and (3) OIL, a competitive drilling game designed to teaching principles of petroleum migration and entrapment while developing skill in working with structure contour maps.All three programs have proved highly successful as teaching tools. Equally important, they are enjoyed by most students.     

虚拟喷泉的计算机生成技术

介绍粒子系统和水波的物理学特性,研究生成模拟喷泉、水波、浪花及泡沫的理论基础．用粒子系统模拟喷泉、浪花及泡沫．实验证明该方法在生成速度和图像上都能获得非常好的效果．     

模拟投资过程的计算机游戏系统

介绍了一种计算机游戏的设计思想与设计过程。该游戏的基本设计思想是根据投资的收益与风险,最终确定一个企业的真正收益。通过人机互动过程模拟现实企业的投资过程,可以在此基础上收集企业投资的辅助决策信息,为真正的投资过程积累必要的经验。     

Computer simulation of large frame structures

A weapon test canister frame provides a structural platform for a weapon device and associated diagnostic instrumentation. The underground environment in which a test canister is placed results in the canister being subjected to large static loads. Excessive canister deflection under load may result in misalignment of optical lines-of-sight, with resulting degradation of the quality of the experimental physics data which is obtained. Each weapon test costs tens of millions of dollars and takes months or years to design and construct, and thus it is essential that the canister structure maintains functionality and prevents excessive deformation under load. In the current paper, a discussion of computer modeling and model verification for canister structures is presented. Two different approaches for performing computer simulation of the response of canister structures are discussed. One approach consists of a brute force detailed finite element model in which a classical finite element technique is employed to model the structure in great detail. The second approach employs a reduced-order, equivalent continuum model to represent the canister structure. The continuum model is based on a special purpose methodology which allows representation of the global behavior of large canister structures with an efficient and economical model. Canister modeling results for both modeling approaches are presented in this paper and compared to experimental data from actual canister tests. Finally, the utility of numerical simulations in identifying an effective technique for canister frame stiffening is discussed.     

Computer simulation of oral fluoride clearance

The presence of fluoride in saliva and dental plaque is important for prevention of dental caries. The elimination of fluoride from the oral cavity after introduction of a fluoride containing agent is a complicated physiological process. This process was simulated with a Pascal program running under MS-DOS on IBM-compatible microcomputers. The program calculated the fluoride concentration in saliva as a function of time from several input parameters, the most important being the amount of fluoride, salivary stimulation due to the fluoride vehicle, resting salivary flow rate and volume factors. Furthermore, factors such as excretion of fluoride in the saliva following fluoride absorption in the intestinal tract were modeled. The fluoride concentration in dental plaque due to diffusion was also calculated. Output was directed to files which could be processed by a graphics interface. The results of the computations were very similar to findings in vivo.     

Computer simulation of air pollution chemistry

The computer simulation of air pollution chemistry is a powerful technique for the understanding of the formation of air pollutants and the development of effective strategies for the control of air pollution. The present status of computerized mathematical modeling of air pollution chemistry is reviewed, typical examples of recent applications are presented and present areas of uncertainties are discussed. The four major areas of air pollution chemistry that are reviewed include photochemical oxidants, acid deposition, atmospheric aerosols and air toxics. The effect of atmospheric physical processes on air pollution chemistry if briefly discussed. The numerical techniques used for the simulation of atmospheric chemistry are reviewed.     

微传感器和执行器的计算机模拟技术

介绍了计算机模拟技术在微传感器和微执行器设计中的应用 ,通过对多晶硅压力传感器和微泵膜片的计算机模拟分析 ,优化了器件的结构设计。研究工作表明计算机模拟是微传感器和微执行器设计的有效工具     

Computer simulation of distorted structural frameworks

The paper describes procedures which may be used to produce visual simulations of distorted structural frameworks in the form of computer-generated shaded pictures. The system operates as a post-processor for standard framework analysis routines and produces scenes which consist of distorted structural elements and models of loads and supports. Applications of the system to the display of individual elements, two-dimensional bents and three-dimensional frameworks are illustrated.     

一种电点火具仿真装置的研究与实现

该文从电点火具的发火原理出发,分析了电点火具由于存贮中发火性能退化引起发火参数分布特性变化规律,提出了一套可以模拟不同存贮条件下各类电点火具发火特性的仿真原理和工程实现方法,并给出了具体的工程实现实例,验证了仿真原理及设备的实用性和可靠性。试验证明该仿真原理和设备可应用于各类电点火具的发火仿真试验。     

Computer simulation in radiation damage studies

The application of atomistic computer simulation to problems involving radiation damage and lattice defects in crystalline solids is discussed. The different topics include static defect configurational simulations, molecular dynamics of thermal motion, low energy atomic collision events, high energy atomic displacement cascades, and the thermal annealing of concentrations of defects in a region of lattice. The methods described are evaluated from the point of view of the assumed physical models, and their capabilities and limitations are indicated. Emphasis is on techniques used rather than on results obtained.