模糊规划在炼油厂生产计划优化中的应用

生产计划的编制是炼油化工企业生产经营管理中的一个关键环节，然而由于市场变化的不确定性，使得企业的长远规划制定受到限制，笔者将模糊数学应用于炼厂生产计划的编制，通过模糊规划对炼油企业生产计划进行优化，使编得的生产计划在一定程度上反映市场的变化并使企业的生产效益最优，为企业管理决策者进行长期规划给予指导，给出了实例来说明该方法的可行性。     

Minimum spanning trees made easier via multi-objective optimization

Many real-world problems are multi-objective optimization problems and evolutionary algorithms are quite successful on such problems. Since the task is to compute or approximate the Pareto front, multi-objective optimization problems are considered as more difficult than single-objective problems. One should not forget that the fitness vector with respect to more than one objective contains more information that in principle can direct the search of evolutionary algorithms. Therefore, it is possible that a single-objective problem can be solved more efficiently via a generalized multi-objective model of the problem. That this is indeed the case is proved by investigating the computation of minimum spanning trees.This work was supported by the Deutsche Forschungsgemeinschaft (DFG) as part of the Collaborative Research Center Computational Intelligence (SFB 531) and by the German-Israeli Foundation (GIF) in the project Robustness Aspects of Algorithms.     

输气干线单个分输站站址最优化研究

输气干线分输站站址规划设计合理与否，直接影响到分输站至各城市门站之间输气管线总投资和未来管网系统的发展。为此,着重讨论并建立了以分输站站址、各城市门站与分输站之间管道直径、壁厚、分输站压力为设计变量，以各城市门站与分输站之间管道投资最小为目标函数的分输站站址优化数学模型。根据模型特点，采用混合离散变量复合形法与数据库技术相结合来求解分输站站址。以此站址为参考点，结合现场勘察，在参考点附近沿输气干线预选多个分输站站址，并对影响分输站建设和管理的环境因素用多目标模糊评价方法进行综合评价，以评价效果好的站址为最优分输站站址。用算例说明了分输站站址优化结果不仅与工艺参数变化有关，且与分输站所处环境因素有关。提出还应深入研究输气干线中具有多个分输站的站址优化问题。     

Optimal synthesis of tunable elastic wave-guides

Topology optimization, or control in the coefficients of partial differential equations, has been successfully utilized for designing wave-guides with precisely tailored functionalities. For many applications it would be desirable to have the possibility of drastically altering the wave-guiding properties of a device “on the fly,” in a controllable manner as an influence of some external input. This would enable wave-guides with highly non-linear input-output mappings, such as for example controllable wave switches.In this paper, we propose using finite elastic pre-straining for the purpose of tuning a wave-guide. In order to systematically formulate and solve the wave-guide synthesis problems we utilize mathematical programming methods in conjunction with topology optimization for parametrizing the design space. The resulting extremal problem is, from a practical point, equivalent to finding an optimal subdivision of a given control volume into two disjoint subsets occupied by two different materials, normally resulting in a highly heterogeneous elastic body with desired wave-guiding functionalities in the original and finitely deformed configurations.The proposed methodology is illustrated with numerical examples.     

Influence of Production Process Parameters on Fish Oil Quality in a Pilot Plant

ABSTRACT: A pilot plant used for upgrading herring byproducts into fish oil was analyzed on its operational efficiency and product quality. The temperature of the heat exchanger and the speeds of the pump and the 3-phase decanter were varied according to a 2³ fractional factorial design. The initial amount of oxidation products present in the crude oil, its storage stability, and the yields from the different obtained products were determined. Multivariate data analysis of the advanced screening stage showed that T had neither influence on the quality nor on the yield in contrast to D and MP (P < 0.05). Process optimization results showed that the quality of the oil was influenced by an interaction effect between the speed of the MP and the D. Oils processed with the highest MP speed were the most stable during storage.     

炼油化工装置技术改造的决策与实施

针对炼油和石化工业装置技术改造的特点，系统地总结了技术改造的类型和改造方案的制定、决策及实施的原则、程序和方法，指出对炼化装置实施技术改造是一项极其复杂、极具难度的系统工程，必须结合实际情况，以投资回报最大化为原则，通过深入细致地研究和反复比选优化改造方案，并结合现场情况制定切实、可靠、安全的实施方案。     

汽轮机回热系统给水焓升的最优分配

从汽轮机回热系统的实际情况出发，运用非线性规划理论和计算机技术，解决了给水焓升设计中的最优分配问题。结合具体实例，针对国产200MW汽轮机回热系统给水焓升的分配进行了说明。     

多部件设备维修问题研究及遗传算法求解

合理组织设备维修，缩短设备维修时间是生产运营管理的一个重要环节。本文探讨了多部件设备维修的有效组织问题。考虑到维修工人对拆分后设备的不同部分具有不同的维修效率，提出了一种基于维修时间优化的决策方法，将其与经典指派方法进行了比较；进一步地，对这一NP-hard问题设计了遗传算法，通过数值例子讨论了其求解有效性。     

Schubspannungsbomben in Faserverbunden

Shear Bombs in Fibre Composites Despite an optimum external shape non‐load adapted internal fibre orientation can lead to the formation of shear cracks where crossing tension‐compression principal stress trajectories create localized shear peaks. Trees are subject to those failure because they cannot re‐arrange their fibres after wood formation. Bones can adjust their micro‐structure to changing load conditions and in this way can better control shear failure. The engineer working with fibre composites should be alert to avoid fibre arrangements not following the force flow. Localized shear zones may also form near notches similar to normal notch stresses, however they are not always situated at the contour line of the notch.     

随机模拟在电信网性能评价中的应用

本文介绍了可在微机上实现大规模电信网践模拟的实用化软件ＳＩＭＵＮＥＴ，及基所采用的无时钟事件追踪法。该软件可用规划中的电信网络和实际网路的模拟及性能评价，也可用于不同流量控制算法的评价。文中给出一个评价实例。