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Numerical simulation of low velocity, small missile impact of laminated architectural glass
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
A New Algorithm to Measure the Convergence of PSO with an Application to Hydronic Design in Buildings
No full textThe particle swarm optimization (PSO) method is one of the simplest methods to apply in order to solve HVAC engineering design optimization problems. The effective application of this method in design requires an appropriate criterion for convergence and a good estimate of the number of particles to use. A common way to check for convergence in many iterative methods is to monitor the change in the objective function. However, in this paper, the authors propose using the distribution of particles to determine the convergence of the PSO method. Because of the variety of objective functions that may be possible in HVAC design, the authors investigate the rate of convergence and the appropriate number of particles using some representative test functions as well as a practical hydronic design problem. The hydronic problem simulates closed-loop systems starting with two floors and a basement to 28 floors and a basement. The results show that the PSO method does not always convergetothe solutionwhen aninsufficient number of particles are used and may be too costly if too many particles are used. For the hydronic design in this study, the recommended number of particles is eight for a two-floor building increasing to 32 for a 28-floor building. In other HVAC design problems, the same number of particles may be used to start the iteration proces
Modelling Fracture in Laminated Architectural Glass Subject to Low Velocity Impact
No full textStandard finite element wave propagation codes are useful for determining stresses caused by colliding bodies; however, their applicability to brittle materials is limited because an accurate treatment of the fracture process is difficult to model. This paper presents a method that allows traditional wave propagation codes to model low velocity, small missile impact in laminated architectural glass such as that which occurs in severe windstorms. Specifically, a method is developed to model typical fractures that occur when laminated glass is impacted by windborne debris. Computational results of concern to architectural glazing designers are presented
Variations on the Author
Get PDF“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
Get PDFWe 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
Low Velocity Impact Resistance of Laminated Architectural Glass
No full textRecently developed finite element algorithms are used to study the effect of glass ply geometry on low velocity, small missile impact resistance of laminated architectural glass. The impacts studied are those typically found during severe windstorms, in which debris such as roof gravel can attain sufficient velocity to break windows in large high rise buildings. Outside ply fracture and interlayer debonding are both incorporated in the finite element analysis. It is shown that glass ply geometry can significantly affect the impact resistance of laminated glass. Three-layer laminates are shown to offer better impact resistance than five-layer and seven-layer laminates of the same overall thickness. For three-layer laminates of the same overall thickness, those with thin outside glass plies provide better impact resistance than those with thick ones
Designing HVAC Systems Using Particle Swarm Optimization
No full textMany design and operating goals in heating, ventilating, and air conditioning (HVAC) systems are optimization problems. For example, building operators want to determine the combination of equipment and set points that obtain the most energy efficient operating conditions. Similarly, HVAC system designers want to determine the best combination of equipment, components and operating conditions that provide minimum lifecycle cost. In both problems, the goal is to find an optimal set of system design variables.
The purpose of this work is to apply a relatively recent optimization technique known as particle swarm optimization (PSO) to the design and operation of HVAC systems. This algorithm is based on the idea of swarms of animals, such as flying birds or insects, searching for food. In these swarms, each member gains knowledge from the whole and in turn contributes his individual knowledge back to the swarm. The result is a very efficient way to find the best available food source. The PSO algorithm is well suited to computers with multiple processors and to HVAC problems because it does not require continuous or well behaved mathematical functions. Another advantage of the method is that it is remarkably simple to implement. This paper illustrates the PSO algorithm by applying it to the design of an HVAC piping system
Modeling Interply Debonding in Laminated Architectural Glass Subject to Low Velocity Impact
No full textStandard finite element wave propagation codes are useful for determining stresses caused by the impact of one body with another; however, their applicability to a laminated system such as architectural laminated glass is limited because the important interlayer delamination process caused by impact loading is difficult to model. This paper presents a method that allows traditional wave propagation codes to model the interlayer debonding of laminated architectural glass subject to low velocity, small missile impact such as that which occurs in severe windstorms. The method can be extended to any multilayered medium with adhesive bonding between the layers. Computational results of concern to architectural glazing designers are presented
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