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The potential of using differences in log crude mortality rates, matched age for age, as a simple means of comparing two mortality studies is investigated. Graphical displays of such differences, plotted against age, are advocated and a method of curve fitting described. A number of applications are presented, and the results of this approach compared with known results, where available. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Azeotropic distillation as an early and important special distillation process is commonly used in laboratory and industry. It can be used for separating the mixture with close boiling point or forming azeotrope. This paper tries to provide a review on azeotropic distillation for general readers, focusing on entrainer selection and mathematical models. Since the 1950s, along with extractive distillation, azeotropic distillation has gained a wide attention. Like extractive distillation, the entrainer, i.e., the third component added to the system, is also the core of azeotropic distillation. In the process design and synthesis, the graphical method (in most cases refer to as triangular diagram) is often employed. But it is better to take on the results from graphical method as the initial values of rigorous equilibrium (EQ) stage/non-equilibrium (NEQ) stage models. One outstanding characteristic of the EQ/NEQ stage models different from extractive distillation and catalytic distillation is to describe phase split for heterogeneous azeotropic distillation. In general, the operation process is very sensitive to some parameters in the case of more than one azeotrope formed, and thus the phenomenon of multiple steady states (MSS) tends to appear. [ABSTRACT FROM AUTHOR]

Generalized functions, in particular the Heaviside unit step H(t) and the Dirac delta impulse δ(t), are valuable teaching tools in many contexts of electric circuits. However, engineering undergraduate courses and textbooks normally cover only an introduction to these functions along with their basic properties, without tackling the rigorous mathematical framework of the theory of distributions. In this work, the Heaviside function is used to represent a square wave signal f(t), and the Dirac function appears when the derivative is calculated. The steps for obtaining f'(t) compare a graphical method with analytical procedures that employ the chain rule. The topic is further extended with the presentation of a theorem and a proposed corollary related to the study of the chain rule applied to general functions involving H(t) and δ(t). Thus, the work provides an appropriate mathematical support for the intuitive graphical method of analysis, which is very familiar in engineering practice. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to show how the modeling of an electromechanical system can be addressed using the energy-based graphical modeling technique named “Power-Oriented Graphs” (POG). Differences and analogies of POG against Bond Graphs modeling technique are discussed. The paper presents the POG dynamic model of an automatic corking machine for threaded plastic caps: the system is composed by two electric motors moving a ball screw/spline that realizes the linear/rotary motion necessary to screw a plastic cap on a bottle. First an extended POG model is presented, together with the equivalent Bond Graph model, then some proper congruent state space transformations and a POG-based graphical method are introduced to transform and reduce the system dynamic model. Simulation and experimental results are finally presented and compared. [Copyright &y& Elsevier]

Based on graphical method, this paper proposed the necessary condition of zero liquid discharge (ZLD) and optimized the corresponding regenerated water flowrate and regeneration concentration for single contaminant water system with fixed mass load. As far as the water system without water loss is concerned, ZLD can be accomplished when the post-regeneration concentration is not higher than the minimum limiting inlet concentration of all the operations. Moreover, considering the water system with water loss, the formulations for calculating the optimal targets (the optimal regenerated water flowrate and the optimal regeneration concentration) for ZLD are deduced. The maximum post-regeneration concentration for ZLD is defined. If the post-regeneration concentration is not higher than it, ZLD is feasible. The optimal zero discharge water network is constructed with a given post-regeneration concentration. [ABSTRACT FROM AUTHOR]

Representative interpretation criteria are examined in detail to evaluate the lateral response of drilled shaft foundations in gravels. A database of field lateral load tests is used for the analysis. The representative criteria are subdivided into absolute displacement, displacement as a function of shaft diameter, rotation limit, mathematical model, and graphical construction method. Comparison of these criteria shows that the initial elastic region ends at approximately 3-5 mm, 0.50 %B, and 0.08° rotation, which represent the serviceability limit state. The final region begins at about 25 mm, 2.5 %B, and 0.33° rotation, which represent the ultimate limit state. The graphical construction methods, Q and Q, are located within the transition region of the curve. Among these criteria, the displacement limits, Q, and Q methods demonstrate more reliable results. The typical load-displacement curves for lateral capacity in gravels are developed for engineering practical use. Further, recommendations for the use of these interpretation criteria are also given. [ABSTRACT FROM AUTHOR]

The last several years have seen an increasing emphasis on mathematical models, both based on statistics and on machine-learning. Today Bayesian nets, neural nets, support vector machines (SVM), and induction trees, are commonly used in the analysis of scientific data. Moreover, a recent emphasis in the modelling community is on improving the performance of classifiers through ensembling more different and accurate models in order to reduce the prediction error. Ensembling in fact is a way of taking advantage of good models that make errors in different parts of the data space. We will outline the developments in model construction and evaluation through those techniques justify their use and propose some quantitative structure activity relationships (QSAR) and models based on ensembling. The models presented here are in the area of predicting acute toxicity for the purpose of regulatory systems. The emphasis is on the better performances of ensembles, since the general goal of delivering usable QSAR models requires others that are out of the scope of this article. [ABSTRACT FROM AUTHOR]

We compare four graphical techniques for representation and solution of asymmetric decision problems--decision trees, influence diagrams, valuation networks, and sequential decision diagrams. We solve a modified version of Covaliu and Oliver's Reactor problem using each of the four techniques. For each technique, we highlight the strengths, weaknesses, and some open issues that perhaps can be resolved with further research. [ABSTRACT FROM AUTHOR]