Heuristic solution approaches to the pharmaceutical R&D pipeline management problem

The paper presents two heuristic approaches, a shrinking horizon multiple two-stage stochastic programming (MTSSP) decomposition algorithm and a knapsack decomposition algorithm (KDA), for solving multistage stochastic programmes (MSSPs) with endogenous uncertainty, specifically focusing on pharmaceutical research and development (R&D) pipeline management problem. The MTSSP decomposition algorithm decomposes the problem into a series of two-stage stochastic programmes, which are solved as resources become available. The KDA decomposes the MSSP into a series of knapsack problems, which are created and solved at key decision points on a rolling horizon fashion. Based on the results of the six case studies, both the MTSSP decomposition algorithm and the KDA generate implementable solutions that are within three percent of the rigorous MSSP solution obtained by CPLEX 12.51. Both methods showed several orders of magnitude decrease in the CPU times compared to ones that were required to solve the rigorous MSSP.     

Oil migration: Novel approaches to a familiar problem

Oil migration in chocolate and chocolate‐coated confections is a familiar yet poorly understood phenomenon that results in undesirable product changes including softening of chocolate coatings and fat bloom on the chocolate surface. Understanding the mechanism behind oil migration would benefit manufacturers as it would aid in maximizing product shelf life and reducing consumer rejection, but current models prove too simplistic to account for the complex nature of chocolate. This review briefly summarizes recent works attempting to move beyond a simple diffusion‐based model by employing new modeling or experimental techniques.     

Novel tools for coating developers: a solution to the inverse problem in formulation

The inverse problem in coating formulation, i.e., that of finding a formulation that will satisfy a given set of performance properties, is much more difficult than the direct problem of finding the properties of a given formula. While the latter case may be labor intensive and time-consuming, we have at hand a wealth of test methods that make the solution straightforward. By contrast, the former case calls for experienced formulators plus intensive trial-and-testing work. In this work we describe a way to use intelligent systems in the form of artificial neural networks and genetic algorithms to tackle the more difficult inverse problem. It is applied to a set of five different families of alkyd enamels. In the direct mode, we are able to predict performance of a formulation with 90% efficiency. Through a sensitivity analysis, we can also obtain those variables to which a given property responds more strongly. In the inverse mode, we can obtain enamel formulations that will satisfy a given set of performance requirements. On the whole, it constitutes a powerful lab tool for coating developers. Computer-proposed formulations with some prescribed characteristics and their laboratory tests are discussed. Presented at the 2006 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in New Orleans, LA, on November 1–3, 2006. Javier E. Vitela On Sabbatical Leave from Instituto de Ciencias Nucleares, UNAM, 04510 México D.F., México     

气化炉测温热电偶存在的问题和解决方法

通过分析气化炉测温热电偶存在的问题，阐述其解决的方法和所采用的新材料、新工艺。工业运行试验结果表明，使用新材料和新工艺所制造的气化炉热电偶各项技术指标已达到或超过进口产品的先进水平。     

一类线性规划问题的最优解

讨论系数矩阵A为全单位模矩阵 ,c、x、b为整数向量的一类线性规划问题 ,对于任给的原 对偶问题的可行解 ,得到了关于这类线性规划问题最优解的几个结论     

用计算机解决8 puzzle problem

本文介绍的是在计算机的发展过程中 ,利用不同的方法对同一个问题的解决。首先是在传统的图灵机模型下通过建立完整的求解模型后再通过程序运算完成问题的求解 ;其次是利用计算机本身具有的智能推理和运算能力实现问题的求解     

Optimal solution to the multinomial selection problem for two alternatives

The multinomial selection problem is to find a stopping policy for repeated independent trials, each of which reports a winner among competing alternatives that has low expected cost and high probability of correct selection (PCS) of the best alternative. In 1959, Bechhofer, Elmaghraby, and Morse formulated the problem as minimizing the worst-case expected number of trials, subject to a lower bound on PCS and upper bound on the maximum number of trials, over all probability vectors outside an indifference zone. For the case of two alternatives, we prove that if one employs a particular probability vector known as the slippage configuration, then a linear program always finds an optimal stopping policy.     

Venus200 X荧光分析仪的制样方法和标样的制备及其维护

<正>0前言我公司自投产以来就采用帕纳科的Venus200X荧光分析仪来控制原料质量,包括石灰石、黏土、泥砂岩、铁粉以及生料的质量控制。其中石灰石、黏土的质量控制包括:矿山质量控制、进厂预均化控制以及入生料磨磨前原料控制等,由于检测速度快而准,为提高生料质量提供了可靠的依据.     

Determination of fiberglass lengths: Sample preparation and automatic image analysis

The optimization of end product properties of fiberglass reinforced engineering thermoplastics must be based upon knowledge of the constituents, including the fiber length distribution. This paper presents the techniques developed for the recovery, dispersal and length distribution analysis of glass fibers recovered from filled engineering resins. An automatic image analyzing computer system is used for the determination. The tedious manual method of measurement from optical photomicrographs is replaced by a rapid, quantitative and reproducible analysis.     

聚氨酯胶粘剂水解问题的有效解决途径

聚合物有几种主要的降解机理:热降解、化学物降解、氧化降解、微生物降解以及水解降解。其中,水解是缩聚反应生成的聚合物最致命的弱点,聚氨酯粘合剂也不例外。水解使聚合物的力学性能在一段时间后丧失殆尽,严重影响了其使用性能和应用范围。碳化二亚胺(Stabaxol~(?))是为解决酯类聚合物水解问题而研制的高效抗水解剂。文章描述了碳化二亚胺抗水解剂在聚酯型聚氨酯粘合剂中的水解保护机理及效果。     

The use of cubic spline and far-side boundary condition for the collocation solution of a transient convection-diffusion problem

Cubic spline collocation method with the far-side boundary condition has been proposed as a numerical method for the convection-dominant convection-diffusion problem. It has been shown that the proposed method can give highly accurate result for very large Peclet number problems by effectively suppressing the undesired ripple that is commonly observed in ordinary orthogonal collocation method.     

稀硝酸溶液配制新装置研发及应用

近年来,硝酸市场产品结构发生改变。为满足市场需求,结合所在公司的项目,决定利用公司现有硝酸产品及生产工艺的优势,自主研发出配制各种浓度硝酸产品的生产装置,以提高企业的抗风险能力。     

An improved rapid physicochemical assay method for aflatoxin in peanuts and peanut products

A practical, short cut, sensitive method for more rapidly determining aflatoxin in peanuts and peanut products has been developed. This was in response to the need to reduce the time required for analyses of peanut products in process. Through reductions in solvent volumes, utilization of pressure filtration for clarification, and substitution of liquid:liquid extraction for a lengthy column clean up, equivalent results are possible in less than one half the time required for the current official procedures. Sensitivity, precision and accuracy are comparable to the current methods for raw nuts and peanut butter. It is now possible to analyze a given ground sample of peanuts within a period of less than 90 min and one analyst can assay more than 16 samples within an 8 hr working day. Presented at the AOCS-AACC Joint Meeting, Washington, D.C., April 1968.     

Theoretical prerequisites,problems, and practical approaches to the preparation of carbon nitride: A Review

Techniques for practical preparation of carbon nitride have been developed and tested by analyzing the currently available data on the methods and approaches to the synthesis of a hypothetical crystalline carbon nitride with due regard for its theoretical characteristics. The conclusions regarding the prospects of these approaches to the preparation of stoichiometric carbon nitride have been drawn from data of the study of its composition, X-ray powder diffraction and microstructural analyses, IR spectroscopy, and mass spectrometry.     

Vinyl chloride,identification and solution of a problem

More than 8 years have passed after the identification of vinyl chloride (VC) as having a carcinogenic potential. It appears to be useful to recapitulate the development of the VC disease and of the measures in the PVC producing plants, taken until now, in the Federal Republic of Germany. It can be shown how this problem has been solved by cooperation of all persons involved, the chemical companies, the organizations responsible for occupational safety, the trade-unions representatives, the physicians and other experts. As a result of the manifold technical, medical, and other precautions, the operating conditions could be improved essentially. Currently, concentration levels of VCM in the workplace amount to 1 ppm or below in nearly all plants.     

P-4600NMA型离心机研条问题的解决

分析了P-4600NMA型离心机产生研条的原因，并制定出合理的检修方案，圆满地解决了离心机产生研条的问题。     

Use of zinc acetate in extract purification for aflatoxin assay of cottonseed products

The official Association of Official Analytical Chemists’ and American Oil Chemists’ Society’s methods for aflatoxin assay of cottonseed products utilize 20% lead acetate solution to remove gossypol, fatty acids, and traces of lipids as insoluble lead derivatives. The substitution of a 20% zinc acetate solution containing a trace of a trivalent metal chloride to precipitate zinc derivatives yields, in some cases, superior cleanup of interfering compounds of primary extracts.