On the role of bounds in stochastic linear programming

Stochastic linear programming (SLP) models involve multivariate integrals. Although in the discretely distributed case these integrals become sums they typically contain a large amount of terms. The purpose of this paper is twofold:On the one hand we discuss the usage of bounds concerning integrals for constructing SLP algorithms and secondly we point out the role of bounds-based algorithms for solving SLP problems. The conceptual considerations are demonstrated in the last section by computational results. The tests have been carried out by utilizing SLP-IOR, our model management system for SLP     

微光像增强器噪声功率谱测试研究

在微光像增强器成像中 ,迭加在图像上的时空域噪声 ,不仅限制系统可工作的最低照度 ,而且使显示图像有随机蠕动颗粒闪烁的外观。适用的噪声性能测试分析技术则可为改善已有系统的成像质量、研制新型高性能的微光成像器件与系统提供必要的基础和客观依据。通过用CCD对像增强器噪声功率谱的测试发现像增强器噪声主要集中在低频部分 ,高频段的噪声近似为白噪声。     

基于CppUnit的虚拟试验单元测试研究

虚拟试验是通过大量平台软件验证实物试验的可行性,达到“以实验虚 以虚辅实 以虚预实”的目的。这对平台软件的稳健性具有较高的要求,软件测试是提高软件产品质量的重要手段,而其中的单元测试是对软件模块的功能测试。CppUnit主要用于实现对软件的单元测试,本文基于CppUnit提出了一种应用于虚拟试验平台软件的单元测试方法,实现了对平台软件功能的单元测试,平台使用者在软件开发阶段不仅能较好地验证软件的稳健性,而且能提高虚拟试验验证的效率,为实物试验提供参考依据。     

AMI通信网络中微功率无线通信的性能测试技术及系统研究

微功率无线通信是高级量测体系(AMI)的主要通信方式之一。各厂家的通信模块性能不一,测试技术尚未形成统一的规范。设计了微功率无线通信的测试系统,由射频性能测试系统和协议一致性分析系统组成。系统采用屏蔽测试箱、多功能电磁波小室、综合测试分析仪、误码分析仪、标准协议信号源等模块组成,屏蔽箱对800MHz频率以下的无线电信号有超过70dB 的抑制,可以提供相对纯净的无线电暗室环境,减少外界无线电波的干扰。测试频率范围为30MHz~1GHz,提供66个测试频点,测试频率误差小于2ppm,误码测试精度小于0.001%,功率测试精度（闭环）为5%（0.2dB）。实现了在实验室情况下对微功率无线网络性能的全面测试和评估,具备很好可操作性、便利性和可复现性。     

强夯密实处理块碎石填料试验研究

在高填方工程中,压实质量是工程成败的关键因素。强夯法所具有的优点,使其在许多地基处理工程中都有广泛的应用。某山区高填方工程,根据工程的实际需要,采用强夯法对山体爆破块碎石填料进行密实处理。为此,开展现场试验研究。首先对爆破的块碎石填料进行了颗粒分析试验和压实试验,分析其可填性和压实特征。按照试验参数和工序,分别进行了2000kN·m、3000kN·m单点夯试验;同时夯后进行了密实度试验、颗粒分析试验。由此,确定了合理的强夯施工参数。最后根据面层载荷试验的检测,以此确定的施工参数在该工程取得了良好的处理效果。     

Studies on synthesis,characterization and adhesive strength evaluation of KFA substituted resole adhesives

Preliminary investigations revealed the presence of appreciable amount of gum rich in lignin and tannin in kendu fruit (Diospyros Cordifolia Roxb). The kendu fruit adhesive (KFA) was used to substitute phenol in resole formulations to achieve cost effectiveness. Substituted resole formulations with 50 and 100% KFA were prepared in alkaline medium through stepwise addition process. Unsubstituted and KFA substituted resole adhesives were then characterized by FT‐IR, thermogravimetric analysis, differential scanning calorimetry and X‐ray diffraction analysis. The adhesive strength of the above mentioned formulations were evaluated by comparing the results of mechanical tests as per the ASTM specifications using UTM‐LR‐100K LLOYD Instruments, UK. Analytical characterizations revealed the substitutions of phenol by KFA in the substituted resole formulations. The results of adhesive strength test revealed that the 50% KFA substituted PF resin exhibits better adhesive strength than the virgin phenol‐formaldehyde and 100% KFA‐formaldehyde resole formulation. Copyright © 2001 John Wiley & Sons, Ltd.     

Fabric Touch Tester: Integrated evaluation of thermal–mechanical sensory properties of polymeric materials

A new test apparatus was designed to evaluate the thermal–mechanical properties of fabric made from polymeric materials in one step. The results of statistical analysis reveal that the sensations of fabric–skin touch under non-sweating conditions like smoothness, softness, prickliness, warmth and dampness can be predicted using the measurements of this apparatus. Heat transfer properties (HF_min) in a fabric play an important role in warmth/dampness perception, which alone accounts for 63.6% and 56.0% of the variance in warmth and dampness perception, respectively. Fabric compression properties (FC_mean) account for 69.5%, 77.0% and 66.7% of the variance in smoothness, softness and prickliness perceptions, respectively.     

Multivariate rank statistics for testing randomness concerning some marginal distributions

In the present paper there is proposed a rank statistic for multivariate testing of randomness conceriing some marginal distributions. The asymptotic distribution of this statistic under hypothesis and “near” alternatives is treated.     

Determining targets for multi-stage adaptive tests using integer programming

This paper considers a multi-stage adaptive test (MST) where the testlets at each stage are determined prior to the administration. The assembly of a MST requires target information and target response functions for the MST design. The targets are chosen to create tests with accurate scoring and high utilization of items in an operational pool. Forcing all MSTs to have information and response function plots to be within an interval about the targets will yield parallel MSTs, in the sense that standardized paper-and-pencil tests are considered parallel. The objective of this paper is to present a method to determine targets for the MST design based on an item pool and an assumed distribution of examinee ability. The approach is applied to a Skills Readiness Inventory test designed to identify logical reasoning deficiencies of examinees. This method can be applied to obtain item response theory targets for a linear test as this is a special case of a MST.     

Factors affecting accelerated testing of polymer photostability

The effect of components of the atmosphere on photostabilized polymers and development of degradation phenomena is outlined. The processes are characteristic of heterogeneity in distribution of products of polymer degradation and stabilizer transformation or consumption. Concentration gradients of the products indicate preferential surface and near-surface changes having U-shaped characteristics and affected by the polymer material or sample thickness due to limited penetration of oxygen. Increased intensity of radiation in artificial sources induces material changes different from those resulting from natural weathering, complicating correlation between the two processes and lifetime prediction. Surface and near-surface analyses of tested samples provide a realistic insight into heterogeneity characteristic of photodegradation.