The Gambler's Ruin Problem, Genetic Algorithms, and the Sizing of Populations

1999 ◽  
Vol 7 (3) ◽  
pp. 231-253 ◽  
Author(s):  
George Harik ◽  
Erick Cantú-Paz ◽  
David E. Goldberg ◽  
Brad L. Miller

This paper presents a model to predict the convergence quality of genetic algorithms based on the size of the population. The model is based on an analogy between selection in GAs and one-dimensional random walks. Using the solution to a classic random walk problem—the gambler's ruin—the model naturally incorporates previous knowledge about the initial supply of building blocks (BBs) and correct selection of the best BB over its competitors. The result is an equation that relates the size of the population with the desired quality of the solution, as well as the problem size and difficulty. The accuracy of the model is verified with experiments using additively decomposable functions of varying difficulty. The paper demonstrates how to adjust the model to account for noise present in the fitness evaluation and for different tournament sizes.

2020 ◽  
Vol 1 (4) ◽  
pp. 6-14
Author(s):  
V. N. Baymatov ◽  
◽  
A. V. Metelev ◽  

Today, less attention has been paid to x-ray studies of animals in connection with the advent of more modern methods. At the same time, the quality of radiopaque substances decreased, which is reflected in this article. The Omnipack, Urografin, Visipack, Barium sulfate, Iodipamide, Bilignost and Biligrafin used in radiopaque contrast studies in most cases did not reveal the hepatobiliary system. Only the last two drugs gave satisfactory results. The complexity of the X-ray examination of the biliary system in cats and dogs lies in the features of the location of the extrahepatic bile ducts and the condition of the intestine, the size of the liver, its structure, echogenicity, the state of the vessels and surrounding organs. In this work, we took into account the anatomical variants of the development and location of organs in animals, which may complicate the study or evaluation of the data obtained. These included changes in the contours, shape, location of the gallbladder and its filling. The results obtained were compared with the available general species standards, taking into account the possible individual characteristics of each animal. Other studied drugs gave satisfactory results with an overall assessment of the abdominal organs, but we preferred Omnipack. Survey radiography provides a large amount of information with the correct selection of radiopaque substances.


Solar Energy ◽  
2002 ◽  
Author(s):  
Nicola Rohner ◽  
Andreas Neumann

The correct selection of the operating wavelength is essential for a precise pyrometric temperature measurement on solar irradiated samples, as the measurement may be disturbed by reflected solar radiation. Atmospheric conditions and particularly the emissivity as basic material property determine the amount of this reflected and the emitted radiation from a sample under investigation. An approach to solve this problem by using a monochromator system for temperature measurement in the UV-B range was developed and experimentally tested. With this system, temperature measurements were possible beginning at 1320°C and ranging up to about 2400°C. Two calculation methods are described and compared. The influence of the calibration temperature on the quality of the temperature measurement is shown. Measurements on a blackbody up to 1500°C were performed for calibration purpose. Temperature measurements on a real solar heated magnesia sample up to 2400°C are presented and discussed. These spectral measurements on hot bodies irradiated in the DLR Solar Furnace led to the final specification of the measurement wavelengths to be in the range from 280 nm to 293 nm.


2016 ◽  
Vol 16 ◽  
pp. 33-51 ◽  
Author(s):  
Abduladim Salem Bala ◽  
Saidin bin Wahab ◽  
Mazatusziha binti Ahmad

This work aims to provide a review of available published literature that explores the opportunities to improve the quality of fused deposit modelling (FDM) products, particularly in medical applications. The paper presents details concerning the basis of the technology, process parameter settings and their responses, and reviews the properties of common FDM engineering/bio-materials and the available methods applied for improving their performance. Based on the researches which have been reviewed, FDM technology works within a complex environment from process parameters. Thus, it can achieve good results only with the proper settings for these parameters according to the properties of the material used. Improving the polymers is essentially based on the correct selection of additive materials, which can particularly enhance the key property/properties in the matrix material. This review provides a brief insight into FDM technology, provides an idea of the process parameter settings, the available materials and ways of modifying their properties to consequently improve the quality of FDM products.


2018 ◽  
Vol 121 ◽  
pp. 351-362
Author(s):  
Aleksander Sobota

Functioning of transport system is determine by the quality of service realized by infrastructure of different transport branches. In case of road transport, very important are intersections. These objects are usually a bottleneck in the network. Therefore, the correct selection of the intersection type is really important in the planning and projecting process of infrastructure. So, decision problem have to be solved by the projectors, who have an influence on these process. But the selection of the intersection type is also the multi-criteria problem. Therefore the answer on the question like, does the intersection type have an influence on environmental conditions, have been presented in the article. For this purpose, the basic assumptions of the method of selections the intersection type, and results of the measurements realized at four type of intersection located on multilane arteries, have been presented in the article.


Author(s):  
M. Franzini ◽  
A. M. Manzino ◽  
V. Casella

Abstract. Dense point clouds can be nowadays considered the main product of UAV (Unmanned Aerial Vehicle) photogrammetric processing and clouds registration is still a key aspect in case of blocks acquired apart. In the paper some overlapping datasets, acquired with a multispectral Parrot Sequoia camera above some rice fields, are analysed in a single block approach. Since the sensors is equipped with a navigation-grade sensor, the georeferencing information is affected by large errors and the so obtained dense point clouds are significantly far apart: to register them the Iterative Closes Point (ICP) technique is applied. ICP convergence is fundamentally based on the correct selection of the points to be coupled, and the paper proposes an innovative procedure in which a double density points subset is selected in relation to terrain characteristics. This approach reduces the complexity of the calculation and avoids that flat terrain parts, where most of the original points, are de-facto overweighed. Starting from the original dense cloud, eigenfeatures are extracted for each point and clustering is then performed to group them in two classes connected to terrain geometry, flat terrain or not; two metrics are adopted and compared for k-means clustering, Euclidean and City Block. Segmentation results are evaluated visually and by comparison with manually performed classification; ICP are then performed and the quality of registration is assessed too. The presented results show how the proposed procedure seem capable to register clouds even far apart with a good overall accuracy.


2021 ◽  
Vol 35 (4) ◽  
pp. 476-483
Author(s):  
Aldir Carpes Marques Filho ◽  
Luiz Henrique Rusconi ◽  
Paulo Roberto Arbex Silva

PLANTABILIDADE E DISTRIBUIÇÃO LONGITUDINAL DE SEMENTES DE ALGODÃO COM DIFERENTES CONJUNTOS DISCO-ANEL EM DOSADOR MECÂNICO   ALDIR CARPES MARQUES FILHO1, LUIZ HENRIQUE MENCK RUSCONI1, PAULO ROBERTO ARBEX SILVA1   1 Departamento de Engenharia Rural, Universidade Estadual Paulista, UNESP/Botucatu, av. Universitária, 3780, Altos do Paraíso, 18610-034, Botucatu, São Paulo, Brasil) [email protected]; [email protected]; [email protected]   RESUMO: A tecnologia em semeadura ou “plantabilidade” é um tema bastante abordado na atualidade e representa a adoção de boas práticas na implantação de lavouras agrícolas. Entre diversos fatores que afetam a qualidade de semeadura está a escolha do conjunto disco e anel dosadores de sementes, como fator de interferência direta na distribuição longitudinal das plantas. Este trabalho teve como objetivo avaliar a interferência da aplicação de dois conjuntos disco-anel de tamanhos diferentes na distribuição longitudinal das sementes na cultura do algodão. O ensaio foi realizado em sistema simulador de semeadura, pertencente ao Núcleo de Ensaios de Máquinas e Pneus Agroflorestais, no Grupo de Plantio Direto (GPD) da UNESP/Botucatu. Os resultados do trabalho mostraram que a seleção adequada do conjunto disco-anel afeta a qualidade da semeadura, sendo que o tratamento T2 apresentou acréscimo de 5% nas falhas e redução de 1% em espaçamentos aceitáveis para a cultura do algodão em semeadura mecânica, assim o percentual de falhas representou um total de 5500 falhas de deposição na lavoura por cada hectare de cultivo. Recomenda-se o uso do conjunto disco-anel T1 (6mm) por ter apresentado os melhores resultados para a variedade de sementes utilizada no experimento.   Palavras-chave: mecanização, tecnologia em semeadura, Gossypium hirsutum L.   PLANTABILITY AND LONGITUDINAL DISTRIBUTION OF COTTON SEEDS WITH DIFERENTS DISC - RING SET IN MECHANICAL DOSER   ABSTRACT: Sowing technology, or “Plantability” is a topic that is widely discussed today and represents the adoption of good practices in the implantation of agricultural crops. Among several factors that affect the quality of planting, the choice of the disc/ring set directly interferes in the longitudinal distribution of plants. This work aimed to evaluate the interference of the application of two disc / ring sets of different sizes in the longitudinal distribution of seeds in cotton crop. Test carried out in a sowing simulator system belonging to the Agroforestry Machinery and Tire Testing Center and the no tillage group (GPD), UNESP/Botucatu. The results of our research showed that the correct selection of the disk-ring set affects the quality of the sowing, and the T2 treatment showed an increase of 5% in the failures and a reduction of 1% in acceptable spacing for the cotton culture in mechanical sowing, as well as the percentage of failures represented 5500 failures of deposition in the field for each hectare of cultivation. It is recommended to use the T1 disk-ring set (6mm) as it has shown the best results for the variety of seeds used in the experiment.   Keywords: mechanization, sowing technology, Gossypium hirsutum L


1999 ◽  
Vol 7 (4) ◽  
pp. 331-352 ◽  
Author(s):  
Dirk Thierens

Scalable evolutionary computation has. become an intensively studied research topic in recent years. The issue of scalability is predominant in any field of algorithmic design, but it became particularly relevant for the design of competent genetic algorithms once the scalability problems of simple genetic algorithms were understood. Here we present some of the work that has aided in getting a clear insight in the scalability problems of simple genetic algorithms. Particularly, we discuss the important issue of building block mixing. We show how the need for mixing places a boundary in the GA parameter space that, together with the boundary from the schema theorem, delimits the region where the GA converges reliably to the optimum in problems of bounded difficulty. This region shrinks rapidly with increasing problem size unless the building blocks are tightly linked in the problem coding structure. In addition, we look at how straightforward extensions of the simple genetic algorithm—namely elitism, niching, and restricted mating are not significantly improving the scalability problems.


2003 ◽  
Vol 125 (2) ◽  
pp. 152-158 ◽  
Author(s):  
Nicola Rohner ◽  
Andreas Neumann

The correct selection of the operating wavelength is essential for a precise pyrometric temperature measurement on solar irradiated samples, as the measurement may be disturbed by reflected solar radiation. Atmospheric conditions and particularly the material emissivity have an impact on these measurements. As an approach to solve this problem, we developed a new system that uses the UV-B wavelength range for pyrometry. Simulations and measurements on blackbodies and on real hot bodies heated in the DLR Solar Furnace specified the final measurement wavelength to be in the range of 280–292 nm. A sensitive monochromator system for this UV-B pyrometry was developed and experimentally tested. Measurements in the range of 1320-1500°C on a blackbody without solar irradiation and measurements from 1500°C to about 2400°C on a real solar heated sample are presented and discussed. Final calibration was performed by using blackbody radiation of 1500°C. Two calculation methods are compared. The influence of the calibration temperature on the quality of the measurement is shown. In this first approach, the resolution of the system turned out to be in the order of magnitude of 1 K and the accuracy in the order of magnitude of 10 K.


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