Logic-based methods

In the logic-based methods, disjunctive constraints or symbolic inference techniques are utilized which can be expressed in terms of binary variables. 

The term chemometrics was hrst coined in 1971 to describe the growing use of mathematical models, statistical principles, and other logic-based methods in the held of chemistry and, in particular, the held of analytical chemistry. Chemometrics is an interdisciplinary held that involves multivariate statistics, mathematical modeling, computer science, and analytical chemistry. Some major application areas of chemometrics include (1) calibration, validation, and signihcance testing (2) optimization of chemical measurements and experimental procedures and (3) the extraction of the maximum of chemical information from analytical data. 

Hooker J. 2000. Logic Based Methods for Optimization Combining Optimization and Constraint Satisfaction. John Wiley and Sons Inc., New York. 

Caballero, J.A. Grossmann, I.E. 2002 Logic based methods for generating and optimizing thermally coupled distillation systems. Procedings ESCAPE 12, J. Grievnik, and J van Schijndel (Editors), 169-174. 

Next the team develops a chronology of events based on the available known times and sequences. This document is usually referred to as a timeline. (See the detailed description of timeline development in Section 9.3.) Unconfirmed assumptions regarding chronology should be clearly identified as unconfirmed, and action should be initiated to verify assumptions. Many investigators use relatively simple timelines (instead of sequence diagrams) with the logic tree methods because the logic tree itself shows the interactions of events and conditions. 

Despite this interest, new reaction types in organic chemistry have been more usually found by chance than by rational design or logical consideration. In this chapter we emphasize that, although they are rarely used, there are both rational and, in particular, algorithm-based methods to discover novel multicomponent reactions. 

The FDA does not intend to set acceptance specifications or methods for determining whether a cleaning process is validated. The user s rationale for the residue limits established should be logical, based on the manufacturer s knowledge of the materials and the practical, achievable and verifiable data. The objective of the inspection is to ensure that the basis for any limits is scientifically justifiable. However, unlike product residues, it is expected that no (or for ultra-sensitive analytical test methods, very low) detergent levels remain after cleaning ... 

The set of questions leads to a logical approach for all potential mixture assessment situations. For example, mixtures of which the composition is unknown or partially known and which have an unknown frequency of occurrence and unknown or unique concentration ratios should be assessed on a case-by-case basis using toxicity tests with whole mixture samples in the field or the laboratory. If this is not feasible, the risk assessor can opt to gather additional data about the mixture composition or its occurrence and subsequently reassess the mixture. It also leads to a logical approach for mixtures of which the composition is known, namely, the application of component-based methods or the use of appropriate data from similar cases. 

When the nonlinear discrete optimization problem is formulated as the generalized disjunctive program in (DPI), one can develop a corresponding logic-based branch-and-bound method. The basic difference is that the branching is performed... 

I strongly believe that in the medical field, it is essential that personnel in management possess a technical degree related in some way to the company s business. From my observation, most non-technical people do not have the logical, fact-based, methodical problem-solving skills needed to solve problems regardless of the business problem faced."... 

Central to VDMP is a method called experience-based reliability centred maintenance (EBRCM) that uses feedback data and decision logic to methodically select maintenance tasks for assets [31]. This approach utilises the internal expert and operating knowledge in collaboration with FMEA s and decision logic methods to create an updated maintenance plan that is unique to the requirements of an organisation. To complement the improvements made by a VDMP, a lifecycle analysis should be carried out before the purchase of any asset to estimate the total cost of an asset before installation. 

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