1,720,965 research outputs found
Design of experiment algorithms for assembled products
No full textDesigning experiments to identify improvement in products that are assembled from manufactured components does not readily fit into conventional design of experiments methods and can be costly. Efficient methods are explored for determining designs for engineering problems where some, or all, of the factors of interest are (a) not easily set to prescribed values and (b) are dependent on a combination of properties of several components. The methods involve taking a sample of each type of component, measuring the relevant features and then finding a design that specifies an optimal set of assembled products for experiment. Three examples from manufacturing industry are presented to illustrate the approach. Two different algorithms for finding designs are described, an exchange algorithm and a genetic algorithm, and a comparison of their performances is made on the three examples
Experiments for derived factors with application to hydraulic gear pumps
No full textFor experiments on mechanical products composed of several components, such as a hydraulic gear pump, conventional methods of designing and implementing factorial experiments can be impractical because of the prohibitive costs of obtaining certain components with factors set to prespecified values. A further difficulty is that often some of the factors that are believed to influence the product's performance are not features of a single component but are derived as functions of the dimensions of several components arising from the product's assembly. Experiments are proposed which use a sample of measured components to explore the influence of such derived factors. An algorithmic method for obtaining efficient designs is presented and applied to finding plans for studies on the gear pump. An experiment on the pump is described which involved both conventional and derived factors. This experiment led to new knowledge on how to improve the engineering design of the pump and, in particular, on how to improve its robustness to the varying pressures that are experienced in operation
An efficient experiment methodology to investigate product design: an acoustic sounder case study
No full textAn innovative experiment methodology is described which enables the investigation, through planned experiment, of component aspects of a manufactured product whose values cannot be economically set to specified values in an experiment. These aspects are called semicontrolled
factors and their presence in an investigation means that conventional experiment plans cannot be employed. The proposed method of experimentation integrates the study of
the manufacturing system and the product design. It involves obtaining samples of components from production and careful measurement of their relevant features. The new approach is demonstrated through a case study on the design and analysis of an experiment to investigate how seven factors influence the performance of an electro-mechanical product called an acoustic sounder. A computer search is used to select from a batch of available components those sets which, when assembled into products, will enable maximum information to be gained from product testing. To facilitate this extensive search, an exchange algorithm and a genetic algorithm have been employed. These algorithms are described and their performances in searching for a plan are compared for the case study
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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