Evaluate the performance of a stochastic-flow network with cost attribute in terms of minimal cuts

This paper proposes a performance index to measure the quality level of a stochastic-flow network in which each node has a designated capacity, which will have different lower levels due to various partial and complete failures. The performance index is the probability that the maximum flow of the network equals the demand d without exceeding the budget b. A simple algorithm in terms of minimal cuts is first proposed to generate all upper boundary points for (d, b), and then the probability that the maximum flow is less than or equal to d can be calculated in terms of such points. The upper boundary point for (d, b) is a maximal vector representing the capacity of each arc such that the maximum flow of the network under the budget b is d. The performance index can be calculated by repeating the proposed algorithm to obtain all upper boundary point for (d−1, b). A benchmark example is shown to illustrate the solution procedure.     

Modeling the effect of pigment morphology on the dynamic compression of coating layers using DEM

In the present paper, discrete element method (DEM) was employed to investigate the effect of pigment morphology on packing dynamics and compressive behavior of paper coating layers in calendering process. Spherical, platy, and needle-like particles, representing GCC, delaminated clay, and aragonite PCC pigments, were considered in this study. For each particle shape, the compression of coating structures formed by mono-sized and poly-dispersed pigments were modeled. Stress–strain behavior of the coating layers and in-plane and out-of-plane movements of the pigment particles during the compression were computed under the same maximum compressive stress. Simulation results revealed that the in-plane movements of the pigment particles during compression in the calender nip were small in magnitude (<0.35 μm). These findings help to better understand the smoothening phenomena of coating structures during the calendering process.     

Fire performance of wood (Pinus radiata) treated with fire retardants and a wood preservative

In this work, we co‐formulated an oil‐borne copper naphthenate/permethrin wood preservative system with synthetic polymer‐based fire‐retardant additives prior to the impregnation of Pinus radiata sapwood. We evaluated what effect, if any, the preservative had upon the fire performance properties of the fire retardants and whether the fire retardants impacted on the fungicidal and termiticidal efficacy of the preservative. The fire retardants included halogenated and phosphorus‐based systems. A mass loss calorimeter, in conjunction with a thermopile, was used to measure the time to ignition and the peak heat release rate (PHRR) from which the fire performance index (FPI) was determined. The preservative properties were evaluated using termite and soil‐block decay bioassays. In summary, we found that the rate of fire growth was reduced when the fire retardants were used in combination with the wood preservative. We also found that the PHRR was a better determinant of fire performance than the FPI. The performance of the wood preservative was enhanced against fungal decay and termite attack when used in combination with the fire retardants. The fire retardants also demonstrated some wood preservative properties of their own. Copyright © 2008 John Wiley & Sons, Ltd.     

An examination of the effect of composite constituent properties on the notched-strength performance of composite materials

The effect of matrix and fiber properties on the strengths and failure processes of notched, continuous-fiber composite specimens has been investigated. Bearing, open and filled hole tension and compression tests were conducted on AS-4/3501-6, IM-8/3501-6, AS-4/APC-2 and IM-8/APC-2 specimens. Failure characteristics of tested specimens were studied by fractographic techniques. Failure progression was tracked by means of incremental loading, radiography and fractographic inspection.     

改进的GMDH方法及其在参数预报中的应用

本文在综合了ＧＭＤＨ方法中几种有效的改进算法的基础上，进一步研究了变量预选及部分表达式的构成问题，采用最优化方法确定变量最佳组成式并进行变量筛选，由此得到精度更高、稳定性较好的模型，将其应用于聚丙烯熔指数的预报，仿真结果令人满意。     

高砂比压裂技术研究

应用由美国ＮＳＩ公司引进的“ｓｔｉｍｐｌａｎ”拟三维压裂设计软件，对影响裂缝内支撑剂铺置浓度的诸因素进行了灰色关联度分析，从中找出了主要的影响因素。并以高砂比压裂的技术指标为依据，研究了在目前压裂工艺水平下，进行高砂比压裂所必须遵循的原则。文中还对国内的高砂比压裂进行了实例分析，进一步论证了文中的观点。     

基于神经网络的智能检索系统

文章首先概述了当前大多数的搜索引擎的主要的弊端；然后着重介绍了智能检索系统的运行基本思路和售用算法，以及该算法在检索领域中运用的优点；最后指出，神经网络运用在检索领域，可解决网络管理中的诸多难题。     

河道堤防老化指标体系评定之浅见

水利工程老化、失修是当前工程不能发挥正常效益的主要原因,建立工程老化指标评价体系是解决该问题的基础工作之一。老化是工程建成后在自然因素和人为活动长期连续的作用下,工程效益衰减、构件功能降低及材料性能逐渐变坏的自然现象。河道堤防以土石为主要材料,应以工程的功能为主建立老化指标体系。依据对工程效益和安全的影响程度,水利工程的综合老化度可分为四级。工程损坏后,在防洪工程运用年度内未能修复称为水利工程失修。解决老化问题主要依靠折旧或大修费,而解决失修问题主要依靠运行管理和维修养护费。     

Volumetric three‐dimensional up‐conversion display medium

Abstract— Several rare‐earth‐doped fluoride crystals that are excited to emit visible light by sequential two‐photon absorption have been investigated as display‐medium candidates for static volumetric three‐dimensional displays. Dispersion of powders of these materials in a refractive‐index‐matched polymer is reported because such a medium may result in a scalable display. The scattering problem in such a medium is greatly reduced by index‐matching the polymer to the crystalline particles. An index‐matching condition that optimizes the performance is identified.     

C pm MPPAC for manufacturing quality control applied to the precision voltage reference process

The multiprocess performance analysis chart (MPPAC) based on the process capability index C_pm, called C_pm MPPAC, is developed for analysing the manufacturing quality of a group of processes in a multiple process environment. The C_pm MPPAC conveys critical information of multiple processes regarding the departure of the process and process variability from one single chart. Existing research works on MPPAC are restricted to obtaining quality information from one single sample of each process ignoring sampling errors. The information provided from existing MPPAC charts, therefore, is unreliable and misleading and results in incorrect decisions. In this paper, we consider the natural estimator of C_pm based on multiple samples. Based on the natural estimator of C_pm, we consider the sampling errors by providing an explicit formula with the Matlab program to obtain the estimation accuracy of the C_pm. We tabulate the sampling accuracy of C_pm for sample size determination so that the engineers/practitioners can use it for their in-plant applications. An example of multiple precision voltage reference (PVR) processes is presented to illustrate the applicability of C_pm MPPAC for manufacturing quality control.