PROFIBUS通讯协议在纺丝线变频调速系统上的应用

论述了PROFIBUS-DP现场总线技术在大庆石化分公司腈纶厂纺丝线电气控制系统改造中的成功实现，分析了PROFIBUS-DP的通讯原理，阐述了SIEMENS S7-300PLC对纺丝电控系统中24台MASTERDRIVES VC型变频器进行启动、停止以及速度给定的控制。     

非标压力机箱形主梁全约束优化设计

根据非标设备结构优化问题的特点,给出满足《钢结构设计规范》(GBJ17 88)规定的箱形主梁全约束优化设计方 法。将编制的内罚函数法优化程序应用于主梁的设计,计算结果表明,该优化方法可应用于实际设计。     

一种矿山用钢筋网自动化焊接生产线的设计

设计一条钢筋网自动化焊接生产线，包括经料送料平台、纬料自动分料及上料机构、多点电阻点焊机、接料平台、卸料机械手。从上料到出料依靠电机、汽缸之间的协调工作来实现。并由单片机和PLC实现控制功能，上位机用MCGS组态软件在整个过程监视现场，采集工作状态及参数，起到监控作用。     

Composite scale modeling in the presence of censored data

A composite scale modeling approach can be used to combine several scales or variables into a single scale or variable. A typical application is to combine age and usage together to form a composite timescale model. The combined scale is expected to have better failure prediction capability than individual scales. Two typical models are the linear and multiplicative models. Their parameters are determined by minimizing the sample coefficient of variation of the composite scale. The minimum coefficient of variation is hard to apply in the presence of censored data. Another open issue is how to identify key variables when a number of variables are combined. This paper develops methods to handle these two issues. A numerical example is also included to illustrate the proposed methods.     

矿井串联系统模糊可靠性理论的研究

矿井系统不仅具有随机性，而且同时也具有模糊性，在系统分析与设计过程中应同时考虑这两种不确定性因素的影响。文中提出了模糊故障、模糊功能、系统模糊运营状态和广义可靠度等概念，并在此基础上提出了求单元及串联系统的生产能力、营运费用、应急维修费用、修理时间和广义可靠度等指标的方法，建立了使系统平均生产能力最大的系统最优运营策略的数学模型。     

An expert PID controller uses refined ziegler and nichols rules and fuzzy logic ideas

This article proposes a scheme for the on-line adjustment of three mode controller settings based on experimental measurements of closed-loop performance. It uses a recently developed heuristic tuning procedure to identify estimated process parameters. This method may give rise to conflicting estimates. Fuzzy Set theory is applied to manage the situation in terms of a fuzzy conjunction to combine the various estimates. PID control was chosen because of its wide use in the industrial environment due to driving simplicity and robustness. The article shows design, development, and computer simulation aspects.     

间断Galerkin方法的最优误差限

本文考虑了数性双曲方程的离散Ｇａｌｅｒｋｉｎ方法。如果精确到光滑的并且同是几乎均匀的，证明了对于分层常数元的最优的和超收敛的误差限。     

模糊综合评判方法在碳酸盐岩油气勘探中的应用

详细地阐述了模糊综合评判方法的数学原理及其在油气勘探开发中的应用.根据某油田的生产层参数资料,运用MICROSOFT EXCEL软件,在对各参数进行统计研究并了解它们分布规律的基础上,合理地构造出一系列隶属函数,通过编制相应的计算机程序,完成综合评判.评判结果与勘探实际吻合较好.该方法有效地适用于碳酸盐岩油气藏的勘探开发.     

Optimizing investment levels for energy conservation: Individual versus social perspective and the role of uncertainty

The decision to invest in energy conservation must be made in the face of uncertainty: future energy prices and the magnitude of energy savings are uncertain. Since once does not know the optimal investment level in advance, one will incur cost penalties due to misoptimization. To analyse the cost penalties it is convenient to focus on the ratio of the life cycle costs that one pays and the life cycle costs one would have paid with an optimal investment level. Two models are used to evaluate this ratio: a model for conductive heat flow through a layer of insulation, and an exponential curve fit to a large number of residential energy conservation cost data. Plotting the life cycle cost ratio versus the ration of actual and guessed energy expenditures shows the effect both of price uncertainties and of uncertainties in the performance of conservation measures. The graph can also be used to evaluate the cost to society due to the mismatch between individual and social perspectives. The curve turns out to have a broad optimum, and penalties due to misoptimization are fairly small in most cases. With these models one can also calculate the long-term price elasticity of energy demand for rational consumers. It turns out to be -0.5 in the insulation model and -1.0 in the exponential model.     

Optimal Control of Solar Sludge Dryers

Optimal control (OC) methodology is used to develop a control policy for a batch-operated solar sludge dryer with ventilation as the dominant control. Batch performance criteria and instantaneous optimization criteria are developed for two economic environments: quota limited and capital limited. The general formulation, as well as simplifications resulting from the multiplicative form of the evaporation (drying) rate model, are presented. The multiplicative form results in a single constant number, called here “control intensity,” which is used to guide the on-line control decisions. These decisions turn out to be independent of the dry solids content (DSC) of the sludge. Further simplification, by assuming a strictly constant weather, is used to demonstrate the general effects of the economic and physical (weather) environment on the solution.

The OC approach is used to address, via simulation under realistic weather conditions, several design, operation, and pricing problems. In particular, the following have been considered: sizing of the ventilation fans, determination of a fair fee for sludge disposal, finding the best final DSC, and evaluating the effect of the price of electricity. Regarding the particular location represented by the data, it has been shown that the installed capacity of the ventilation fans should be increased and that there seems to be sufficient economic incentive for solar drying.