scholarly journals A heuristic method for transmission design

2019 ◽  
Vol 287 ◽  
pp. 01013 ◽  
Author(s):  
Viktor Ivanov ◽  
Lubomir Dimitrov ◽  
Svitlana Ivanova ◽  
Galyna Naleva
Keyword(s):  
Heuristic Search ◽  
Thrust Bearing ◽  
Heuristic Method ◽  
Heuristic Methods ◽  
Double Row ◽  
Intermediate Ring ◽  
Heuristic Techniques ◽  
Transmission Design ◽  
Rolling Element

The application of heuristic methods in the design of transmissions is investigated. The structure of heuristic methods is revealed and the heuristic techniques that compose them are established. These techniques are combined into one generalized method, which allows replacing all the considered methods. A heuristic method specially allotted for the design of transmission is also developed. This method contains, among other things, the following heuristic techniques. Search for all possible variants of elements location corresponding to one of the same graph. Introduction nodes to the graph that corresponding certain function, for the implementation of which a node can be added to the design or vice versa, a node can be removed from the design, and the function it has implemented will be implemented by other elements.The advantages of a heuristic search on the example of designing a double row thrust bearing are evidenced. The bearing contains a node through which the speed of the intermediate ring is always equal to half the speed of the shaft. Due to this, the distance that the rolling element path is reduced, and the bearing has greater durability.

Efficient Optimization of Well-Drilling Sequence with Learned Heuristics

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2111-2134 ◽  
Author(s):  
Lingya Wang ◽  
Dean S. Oliver
Keyword(s):  
Online Learning ◽  
Heuristic Search ◽  
Net Present Value ◽  
Search Algorithm ◽  
Fast Method ◽  
Heuristic Methods ◽  
Sequential Decision ◽  
Solution Quality ◽  
Space Reduction ◽  
Time Accuracy

Summary When preparing a field–development plan, the forecast value of the development can be sensitive to the order in which the wells are drilled. Determining the optimal drilling sequence generally requires many simulation runs. In this paper, we formulate the sequential decision problem of a drilling schedule as one of finding a path in a decision tree that is most likely to generate the highest net present value (NPV). A nonparametric online–learning methodology is developed to efficiently compute the sequence of drilling wells that is optimal or near optimal. The main ideas behind the approach are that heuristics from relaxed problems can be used to estimate the maximum value of complete drilling sequences constrained to previous wells, and that multiple online–learning techniques can be used to improve the accuracy of the estimated values. The performance of various heuristic methods is studied in a model for which uncertainty in properties is neglected. The initial heuristic used in this work generates a higher estimated NPV than the actual maximum NPV. Although such a heuristic is guaranteed to find the true optimal drilling order when used in the A* informed-search algorithm method, the cost of the search can be prohibitive unless the initial heuristic is highly accurate. For the variants of heuristic search methods with weighting parameters, the results show that it might not be possible to identify parameters that can be used to find a solution quickly without sacrificing the accuracy of the estimated NPV in this drilling–sequence problem. In contrast, the online learned heuristics derived from observations from previous drilling steps are shown to outperform the other variants of heuristic methods in terms of running time, accuracy of the estimated value, and solution quality. Multilearned heuristic search (MLHS) with space reduction (MLHS–SR) is an efficient and fast method to find a solution with high value. Continuing the search with space restoration is guaranteed to improve the solution quality or find the same solution as the MLHS without any space reduction.

A Heuristic Method to Identify Modules From a Functional Description of a Product

1998 ◽  
Author(s):  
Robert B. Stone ◽  
Kristin L. Wood ◽  
Richard H. Crawford
Keyword(s):  
Modular Design ◽  
Heuristic Method ◽  
Consumer Products ◽  
Product Development Process ◽  
Heuristic Methods ◽  
New Approach ◽  
Alternative Product ◽  
Product Function ◽  
Functional Models ◽  
Development Processes

Abstract Developing product architectures is a key phase in design and development processes. It encompasses the transformation of product function to alternative product layouts. In this paper, we describe a new approach for identifying modules for product architectures. We begin by reviewing the terminology and motivation for modular products. Following that discussion, three heuristic methods for identifying modules from a formal functional decomposition are presented. To aid in this process, a concept known as functional dependency is introduced to further arrange functional models with respect to time. Through this concept and the heuristic methods, modular design can be executed earlier in the product development process, as illustrated by the running example of a power-tool product. A database of 70 consumer products is used to verify and confirm the overall modular design approach.

Heuristics in Medical Data Mining

2008 ◽  
pp. 2517-2522
Author(s):  
Susan E. George
Keyword(s):  
Data Mining ◽  
Ethical Issues ◽  
Medical Data ◽  
Heuristic Methods ◽  
Medical Data Mining ◽  
Heuristic Techniques ◽  
Mining Methods ◽  
Forward Looking

This chapter presents a survey of medical data mining focusing upon the use of heuristic techniques. We observe that medical mining has some unique ethical issues because of the human arena in which the conclusions are outworked. The chapter proposes a forward looking responsibility for mining practitioners that includes evaluating and justifying data mining methods–a task especially salient when heuristic methods are used. We define heuristics broadly to include those methods that are applicable for large volumes of data, as well as those specifically directed to dealing with uncertainty, and those concentrated upon efficiency. We specifically consider characteristics of medical data, reviewing a range of mining applications and approaches. We conclude with some suggestions directed towards establishing a set of guidelines for heuristic methods in medicine.

Segmentation of retail bank customers for the purposes of modeling the loan claim default

2020 ◽  
Vol 26 (11) ◽  
pp. 2594-2616
Author(s):  
E.V. Pavlova ◽  
V.V. Roskoshenko
Keyword(s):  
Content Analysis ◽  
Statistical Analysis ◽  
Statistical Modeling ◽  
Scoring System ◽  
Practical Problem ◽  
Information Sources ◽  
Heuristic Method ◽  
Heuristic Methods ◽  
Logit Regression ◽  
Loan Size

Subject. In the banking practice, approaches to separate modeling of loan claim default (for new and repeat customers, for customers having and not having a history in the Credit Bureau, etc.) are widespread. Such a segmentation of retail bank customers may increase the efficiency of applied scoring system. The practical problem of choosing the optimal heuristic method of segmentation for the scoring remains unresolved. Objectives. The purpose of this work is to determine the optimal heuristic method of segmentation from those that are known in the literature and the industry. Methods. The study employs statistical analysis and content analysis of information sources. Results. We compared over thirty heuristic methods for segmentation of retail bank customers. The comparison showed that according to the classifier of the efficiency metric (AUROC), our proposed segmentation by the disbursed loan size turned out to be optimal. The method consists in the ‘disbursed loan’ variable discretization under the TreeR method. Conclusions and Relevance. The findings may be helpful in loan scoring and in any statistical modeling, using the logit regression.

Nonlinear vibration response analysis of a double-row self-aligning ball bearing due to surface imperfections

2020 ◽  
Vol 234 (3) ◽  
pp. 514-535
Author(s):  
Vivek Parmar ◽  
VH Saran ◽  
SP Harsha
Keyword(s):  
Ball Bearing ◽  
Contact Stiffness ◽  
High Amplitude ◽  
Vibration Response ◽  
System Response ◽  
Response Analysis ◽  
Double Row ◽  
Outer Race ◽  
Rolling Element ◽  
Intermediate Value

This work attempts to study the vibration response of a double-row self-aligning ball bearing due to surface and localized imperfections. For the contact deformation at the ball–race interactions, the Hertzian load–deflection relation is used for the evaluation of time-varying contact stiffness. The elastohydrodynamic theory is applied to find out the central film thickness. For both the inner and outer race waviness cases, the system response is observed as periodic (with vibrations of high amplitude) at [Formula: see text], i.e. multiples of Nb and its vicinity, but gradually turns to quasi-periodic as the value of waviness order reach some intermediate value. In the case of a localized defect, the double impulse phenomenon marks the entry and exit events of the rolling element in and out of the rectangular spall. Hence, this analysis can be used as a diagnostic tool with system dynamic characteristics for distributed and localized defect identification.

scholarly journals Effect of internal clearance on rolling element load of double row tapered roller bearings

2016 ◽  
Vol 82 (840) ◽  
pp. 16-00205-16-00205 ◽  
Author(s):  
Ken TAKAHASHI ◽  
Daisuke SUZUKI ◽  
Takafumi NAGATOMO
Keyword(s):  
Double Row ◽  
Roller Bearings ◽  
Rolling Element ◽  
Tapered Roller ◽  
Tapered Roller Bearings
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