Efficient Global Optimization of Actuator Based on A Surrogate Model Assisted Hybrid Algorithm

Computationally expensive numerical techniques are often involved in the actuator design optimization process, where efficiency is a major issue. Although surrogate-based optimization is a promising solution, the challenge to the optimization efficiency is still considerable. Aiming to address this challenge, a new method, called the parallel adjoint sensitivity and Gaussian process assisted hybrid optimization technique (PAGHO), is presented. The central concept is a new optimization framework employing computationally cheap partial derivatives obtained by the adjoint sensitivity method to tackle computationally expensive infill sampling for surrogate-based optimization. A silicon microactuator and a mathematical benchmark problem with different kinds of challenges are selected as the test cases. Comparison results show that PAGHO can obtain comparable results with popular global optimization methods, while at the same time having significant advantages in efficiency compared to standard global optimization methods and state-of-the-art surrogate-based optimization methods

Synthesis of a discrete-action thermo-bimetallic actuator with a tongue

The selection of suitable parameters, by experimental or intuitive processes for snap-through actuation of a bimetallic actuator at a prescribed temperature is an extremely time-consuming task. This paper describes a new methodology for the optimization of a discrete action thermo-bimetallic actuator with a tongue. This methodology makes it possible to solve the optimization task with higher efficiency. The requirement is to find optimal parameters values so that the actuator will make a snap-through at a given temperature. The constrained optimization task was performed using an evolutional algorithm and surrogate modelling and this was coded in Matlab. Functional relationships between the criteria and parameters were not set explicitly, but they were calculated using finite element method, each simulation of which was performed in Abaqus

Ferramentas modernas de regulação e gestão do sortimento da empresa

The article proposes a number of tools for managing the assortment of the multinomenclature enterprise; the method of forming the assortment policy is improved. The role and importance of forming the assortment which is adequate to the market requirements and production capabilities are disclosed. Based on the results of leading economists, the necessity to formulate a comprehensive methodology for managing the assortment is concluded. The method of forming the assortment, proposed in the article, is adapted to the modern conditions of management. The assortment policy formation is proposed to be carried out step by step, with the using accounting data and primary information which is obtained through field research and modern Internet technologies. The indexes for estimating the assortment of the production enterprise are listed. The algorithm of an estimation of adequacy of an existing assortment to market requirements and to production possibilities is described. It is proposed to compare the stage of the product life cycle with the level of return of unrealized products and the level of production equipment loading. The integration of modern Internet technologies into the mechanism of the assortment formation is offered. The main emphasis is on calculating the coefficients of adequacy of goods to the market, corrected in real time by statistical data of the firm's website. The using of the assortment list as an instrument of assortment control at points of sale is considered. The article is of an applied nature.El artículo propone una serie de herramientas para gestionar el surtido de la empresa multinomenclatura; el método para formar la política de surtido se mejora. Se describe el papel y la importancia de formar el surtido adecuado a los requisitos del mercado y las capacidades de producción. Con base en los resultados de los principales economistas, se concluye la necesidad de formular una metodología integral para administrar el surtido. El método de formación del surtido, propuesto en el artículo, se adapta a las condiciones modernas de gestión. La formación de la política de surtido se propone llevar a cabo paso a paso, con el uso de datos contables y la información primaria que se obtiene a través de la investigación de campo y las tecnologías modernas de Internet. Se enumeran los índices para estimar el surtido de la empresa de producción. Se describe el algoritmo de una estimación de la adecuación de un surtido existente a los requisitos del mercado y a las posibilidades de producción. Se propone comparar la etapa del ciclo de vida del producto con el nivel de retorno de los productos no realizados y el nivel de carga del equipo de producción. Se ofrece la integración de las modernas tecnologías de Internet en el mecanismo de la formación del surtido. El énfasis principal está en el cálculo de los coeficientes de adecuación de los bienes al mercado, corregidos en tiempo real por los datos estadísticos del sitio web de la empresa. Se considera el uso de la lista de surtido como un instrumento de control del surtido en los puntos de venta. El artículo es de naturaleza aplicadaO artigo propõe uma série de ferramentas para gerenciar o sortimento do empreendimento multinomenclatura; o método de formar a política de sortimento é melhorado. O papel e a importância de formar o sortimento adequado às exigências do mercado e às capacidades de produção são divulgados. Com base nos resultados dos principais economistas, conclui-se a necessidade de formular uma metodologia abrangente para gerenciar o sortimento. O método de formação do sortimento, proposto no artigo, é adaptado às modernas condições de gestão. Propõe-se que a formação da política de sortimento seja realizada passo a passo, com o uso de dados contábeis e informações primárias obtidas por meio de pesquisa de campo e modernas tecnologias da Internet. Os índices para estimar o sortimento da empresa de produção são listados. O algoritmo de uma estimativa de adequação de um sortimento existente aos requisitos do mercado e às possibilidades de produção é descrito. Propõe-se comparar o estágio do ciclo de vida do produto com o nível de retorno de produtos não realizados e o nível de carregamento do equipamento de produção. A integração de tecnologias modernas da Internet no mecanismo da formação de sortimento é oferecida. A principal ênfase é no cálculo dos coeficientes de adequação dos bens ao mercado, corrigidos em tempo real pelos dados estatísticos do site da empresa. O uso da lista de sortimento como um instrumento de controle de sortimento em pontos de venda é considerado.O artigo é de natureza aplicada

Terrestrial bitumen analogue of orgueil organic material demonstrates high sensitivity to usual HF-HCl treatment

The relationship between the chemical composition and the interlayer spacing (d002) of organic materials (OM's) is known for various terrestrial OM's. We improved this general trend by correlation with corresponding trend of natural solid bitumens (asphaltite-kerite-anthraxolite) up to graphite. Using the improved trend we identified bitumen analogs of carbonaceous chondrite OM's residued after HF-HCl treatment. Our laboratory experiment revealed that these analogs and, hence, structure and chemical composition of carbonaceous chondrite OM's are very sensitive to the HF-HCl treatment. So, usual extraction of OM from carbonaceous chondrites may change significantly structural and chemical composition of extracted OM

Thermoelectric prospects of nanomaterials with spin-orbit surface bands

Nanostructured composites and nanowire arrays of traditional thermoelectrics like Bi, Bi(1-x)Sb(x) and Bi(2)Te(3) have metallic Rashba surface spin-orbit bands featuring high mobilities rivaling that of the bulk for which topological insulator behavior has been proposed. Nearly pure surface electronic transport has been observed at low temperatures in Bi nanowires with diameter around the critical diameter, 50 nm, for the semimetal-to semiconductor transition. The surface contributes strongly to the thermopower, actually dominating for temperatures T < 100 K in these nanowires. The surface thermopower was found to be -1 T microvolt/(K^2), a value that is consistent with theory. We show that surface electronic transport together with boundary phonon scattering leads to enhanced thermoelectric performance at low temperatures of Bi nanowire arrays. We compare with bulk n-BiSb alloys, optimized CsBi(4)Te(6) and optimized Bi(2)Te(3). Surface dominated electronic transport can be expected in nanomaterials of the other traditional thermoelectrics.Comment: 18 pages, 3 figure