1,721,028 research outputs found
A quantitative analysis of the stress relaxation effect of thermoplastics in multilayer substrates
No full textAll plastics can be divided into two groups called thermoplastics and thermosets, and each group exhibits very different behaviors. Unlike thermosets, thermoplastics are empirically known by the viscoelastic behavior of the thermoplastic layers; the stress generated by building subsequent layers can be significantly relieved in a multilayer structure. In this study, we quantitatively investigated the stress relaxationf effect of thermoplastics in lamination-based multilayer substrates. As an Increasing number of layers were laminated using either thermoplastic or thermoset adhesives, the maximum bow values were measured layer-by-layer using a laser profilometry during thermal cycling. When analyzed through an analytical model, the measured thermal behavior of thermoplastics exhibited as much as 70% stress relaxation in the multilayer structures, and highly contrasted with that of thermoset adhesives, The result provides an important design guideline that thermoplastics can be used as a stress relaxation layer in lamination-based multilayer substrates
Directional radiation pattern in structural–acoustic coupled system
No full textIn this paper we demonstrate the possibility of designing a radiator using structural-acoustic interaction by predicting the pressure distribution and radiation pattern of a structural-acoustic coupling system that is composed by a wall and two spaces. If a wall separates spaces, then the wall's role in transporting the acoustic characteristics of the spaces is important. The spaces can be categorized as bounded finite space and unbounded infinite space. The wall considered in this study composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. This rather hypothetical circumstance is selected to study the general coupling problem between the finite and infinite acoustic domains. We developed an equation that predicts the energy distribution and energy flow in the two spaces separated by a wall, and its computational examples are presented. Three typical radiation patterns that include steered, focused, and omnidirected are presented. A designed radiation pattern is also presented by using the optimal design algorithm. (c) 2005 Acoustical Society of America
Experimental Evaluation of A General learning Algorithm for Tracking Performance of Robotic Manipulator
No full textComparison between Electroless Ni(P)Au and Cu OSP as a Surface Finish Layer of Mobile Application
No full textNavigation stability: A new isolation level in ORDBMSs
No full textIn order to enhance the performance, many database management systems (DBMSs) execute transactions at isolation level 2 rather than at isolation level 3, the strict two phase locking, even if it sacrifices consistency to a certain degree. Cursor stability, a variant of isolation level 2 in relational DBMs (RDBMSs), has been widely used as a useful technique for obtaining concurrency achievable at level 2 without much sacrificing consistency. However, cursor stability is much less usable in object-relational DBMSs (ORDBMSs) because navigational applications in ORDBMSs can suffer from critical inconsistency problems such as dangling pointers, lost updates, and reading inconsistent complex objects. In this paper, we propose a new isolation level, navigation stability, that prevents the inconsistency problems of cursor stability for navigational applications, while avoiding significant degradation of the concurrency of level 3. First, we analyze the inconsistency problems of cursor stability for navigational applications. Second, we define navigation stability as an extension of cursor stability and show that it solves those inconsistency problems of cursor stability in ORDBMSs. Third, through extensive simulation, we show that navigation stability significantly enhances the performance compared with level 3. For workloads consisting of transactions of long duration, compared with level 3, the throughput of navigation stability is enhanced by up to 200%; the average response time reduced by as much as 55%; and the abort ratio reduced by as much as 77%. From these results, we conclude that navigation stability is a useful isolation level in ORDBMSs that can be used in place of isolation level 3 to improve the performance and concurrency without significant sacrifice of consistency
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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