结合沉积成藏规律实现葡萄花疑难层测井解释

测井综合评价中,常以电阻率测量值的高低来反映岩层的含油饱和程度,以孔隙度测井值来反映岩层的储集能力。由于沉积成藏条件复杂,部分岩层测井评价存在困难,具体归纳为"低阻油层"、"高阻水层"两种情况。弱水动力的低能量沉积环境、辅以较高的地层水矿化度形成"低阻油层";而油气运移"路过"的部分岩层,孔隙内残余原油氧化后致使流体导电能力降低,形成"高阻水层"。以卫星油田葡萄花油层为例,在沉积微相、油气运移成藏规律基础上,分析总结复杂油水分布特征,将电阻率、孔隙度、断层、岩层到葡顶的距离、砂体展布情况等诸要素联系起来,建立综合识别方法,有效提高了这两类疑难储层的测井评价精度。     

Recent advances in mathematical programming techniques for the optimization of process systems under uncertainty

Optimization under uncertainty has been an active area of research for many years. However, its application in Process Systems Engineering has faced a number of important barriers that have prevented its effective application. Barriers include availability of information on the uncertainty of the data (ad-hoc or historical), determination of the nature of the uncertainties (exogenous vs. endogenous), selection of an appropriate strategy for hedging against uncertainty (robust/chance constrained optimization vs. stochastic programming), large computational expense (often orders of magnitude larger than deterministic models), and difficulty of interpretation of the results by non-expert users. In this paper, we describe recent advances that have addressed some of these barriers for mostly linear models.     

钢卷库天车定位及智能导航软件系统设计

主要介绍了唐钢热轧部天车定位及智能导航软件系统。根据1700库、1810库、平整原料库的管理要求设计,以及用户的需要完成入库、出库、倒库、退库、离库等功能。通过优化库房管理、天车作业节能降耗,提高了库房管理水平;实现了吊运过程全记录管理,确保了物流实时跟踪记录的完整性,发挥天车的协同工作效应,减少工人的劳动强度,提高了工作效率。     

The special‐linear update: An application of differential manifold theory to the update of isochoric plasticity flow rules

The evolution of plastic deformations in metals, governed by incompressible flow rules, has been traditionally solved using the exponential mapping. However, the accurate calculation of the exponential mapping and its tangents may result in computationally demanding schemes in some cases, while common low‐order approximations may lead to poor behavior of the constitutive update because of violation of the incompressibility condition. Here, we introduce the special‐linear (SL) update for isochoric plasticity, a flow‐rule integration scheme based on differential manifolds concepts. The proposed update exactly enforces the plastic incompressibility condition while being first‐order accurate and consistent with the flow rule, thus bearing all the desirable properties of the now standard exponential mapping update. In contrast to the exponential‐mapping update, we demonstrate that the SL update can drastically reduce the computing time, reaching one order of magnitude speed‐ups in the calculation of the update tangents. We demonstrate the applicability of the update by way of simulation of single‐crystal plasticity uniaxial loading tests. We anticipate that the SL update will open the way to efficient constitutive updates for the solution of complex multiscale material models, thus making it a very promising tool for large‐scale simulations. Copyright © 2013 John Wiley & Sons, Ltd.     

Variable neighbourhood simulated annealing algorithm for capacitated vehicle routing problems

This article presents the variable neighbourhood simulated annealing (VNSA) algorithm, a variant of the variable neighbourhood search (VNS) combined with simulated annealing (SA), for efficiently solving capacitated vehicle routing problems (CVRPs). In the new algorithm, the deterministic ‘Move or not’ criterion of the original VNS algorithm regarding the incumbent replacement is replaced by an SA probability, and the neighbourhood shifting of the original VNS (from near to far by k← k+1) is replaced by a neighbourhood shaking procedure following a specified rule. The geographical neighbourhood structure is introduced in constructing the neighbourhood structures for the CVRP of the string model. The proposed algorithm is tested against 39 well-known benchmark CVRP instances of different scales (small/middle, large, very large). The results show that the VNSA algorithm outperforms most existing algorithms in terms of computational effectiveness and efficiency, showing good performance in solving large and very large CVRPs.     

Value driven load balancing

To date, the study of dispatching or load balancing in server farms has primarily focused on the minimization of response time. Server farms are typically modeled by a front-end router that employs a dispatching policy to route jobs to one of several servers, with each server scheduling all the jobs in its queue via Processor-Sharing. However, the common assumption has been that all jobs are equally important or valuable, in that they are equally sensitive to delay. Our work departs from this assumption: we model each arrival as having a randomly distributed value parameter, independent of the arrival’s service requirement (job size). Given such value heterogeneity, the correct metric is no longer the minimization or response time, but rather, the minimization of value-weighted response time. In this context, we ask “what is a good dispatching policy to minimize the value-weighted response time metric?” We propose a number of new dispatching policies that are motivated by the goal of minimizing the value-weighted response time. Via a combination of exact analysis, asymptotic analysis, and simulation, we are able to deduce many unexpected results regarding dispatching.     

A Two-Stage Method for an Approximate Calculation of Statically Indeterminate Trusses

The paper presents the principles of a method, which in two simple stages makes possible to carry out the statically calculation of values of forces acting in the fiat static indeterminate trusses. In each stage, it is considered the static determinate truss, scheme of which is obtained after remove the suitable number of members from the basic static indeterminate truss. The both intermediate statically determinate trusses are of the same clear span and they are loaded by forces of half values applied to the corresponding truss nodes. The method applies one of the typical procedures of calculation of the statically determinate trusses and then it is applied in an appropriate way the rule of superposition for obtaining the final values of forces acting in particular members of the basic truss. The values of forces calculated in this way are of a very close approximation to the force values determined in the special and complex ways being considered as the exact calculation methods. The proposed method can be useful mostly but not only for the initial structural design of such systems. The simplicity of the two-stage method justifies an assumption that it can be relatively easy and worthy to adjust to the requirements of the computer aided technology of statically calculation of the complex forms of trusses.     

基于并联机构调姿的大部件支撑点优选

为了提高基于并联机构形式的数字化调姿装置的操作性能和支撑稳定性等,对部件上的支撑点位置进行了优化选择。建立了该定位调姿装置的运动学模型,根据分支机构运动链的矢量图形,求解了定位调姿装置的位置方程及机构雅克比矩阵;根据机构雅克比矩阵建立了调姿装置的灵活度、承载力和刚度等性能评价指标;根据定位雅克比矩阵建立了调姿装置对部件定位时的支撑稳定性指标;对上述指标进行综合评价,根据指标的优化得到了部件的优化支撑点位置。分析结果表明:基于并联机构形式的大部件调姿装置的性能评价指标和位姿无关,支撑稳定性和姿态有关,且各指标依赖于初始支撑点的选择,以上结论为大部件定位支撑点的选择提供了参考。