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Bewildered, the form-maker stands alone
Published in Theodora Vardouli, Olga Touloumi, Computer Architectures, 2019
The September 1958 report, however, did not dwell on interactions with these figures, who would come to be decisive influences on Alexander’s trajectory. Instead, it focused on two under-discussed actors: Vienna-trained art historian Eduard Sekler and applied mathematician and mathematical psychology pioneer R. Duncan Luce. Alexander reported having consulted with Luce on the possibility of using an IBM machine to plot “utility functions for various domains of decision [in a design process]” (Alexander 1958a: 1). “Utility” was a key term in rational choice theory and game theory, measuring the satisfaction of different stakeholders for a given decision in the context of a decision-making process. However, Alexander declared his mistrust of the results of such a computer model, which were contingent on the choice of “premises” (Alexander 1958a: 1)—the starting statements on which logical operations would be applied. The preoccupation with “premises” in the context of logical inference was cultivated in Seckler’s Harvard seminar on art criticism, for which Alexander wrote a paper that “deplored the use of abstract phraseology in architectural writing” (Alexander 1958a: 1).
Managing Relationships
Published in Stephen Holloway, Airlines: Managing to Make Money, 2017
Several streams of literature examine the benefits that draw alliance partners together. Most tend to approach the alliance phenomenon from an economic perspective, sometimes giving relatively little consideration to psychological, social, or cultural influences on decision-making. These ‘rational choice models’ are notably drawn from transaction cost economics and game theory. There are exceptions. Sociology has contributed resource dependence theory (which we briefly met in chapter 6) and network theory. The latter, having in recent years drawn-in contributions from economics and several other disciplines, is gradually encouraging researchers and practitioners to think in terms of the interrelatedness of actors within complex clusters of firms; not all these relationships will necessarily qualify as ‘strategic alliances’, but where such alliances do exist, it can be helpful to consider them as part of the wider network of both loose and tightly coupled relationships within which each partner is embedded. Another exception is institutional theory, which argues that alliances may come about not only as a rational response to the environment but sometimes as a result of internal organizational variables such as culture and the disposition of power.
A comprehensive review on enzymatic degradation of the organophosphate pesticide malathion in the environment
Published in Journal of Environmental Science and Health, Part C, 2019
Smita S. Kumar, Pooja Ghosh, Sandeep K. Malyan, Jyoti Sharma, Vivek Kumar
Protein engineering studies directed towards the understanding of similar structures and catalytic mechanisms across divergent organophosphate degradation enzymes can help in the development of better computational models and screening technologies. The most prevailing approaches available to us in the biotechnological advancement of human and environmental health is directed evolution. Though, with the integration of new technologies to research laboratories, techniques based on rational design approaches are expected to prevail in the near future. Researchers are taking advantage of the wealth of information about protein structure available nowadays. Moving forward, evolved variants of OPH, and opdA have been developed and are now ready to be tested. Phosphotriesterase activity has been observed to be an extremely uninhibited component of many different hydrolases including enzymes from extremophilic hosts. Enzymes purified from extremophiles possess better resilience to deviations in the external environment and are more amenable to genetic modifications, thus providing researchers with highly stable protein scaffolds for next-generation engineering technologies. A major drawback of most of the degradation studies is that they only rely on chemical analysis and study the presence/absence of malathion. However, sometimes degradation may lead to the formation of certain intermediary metabolites which may be more toxic than the parent compound such as malaoxon. So, it is important to ensure that the contaminated site is completely detoxified at the end of the treatment. This can be done efficiently by the use of mammalian cell line based in vitro bioassays which are rapid, simple, sensitive, as well as cost-effective. Thus, future studies should focus on the detoxification aspect along with degradation.
Chip seal design framework with life-cycle cost analysis for local agencies
Published in Road Materials and Pavement Design, 2021
Local agencies and contractors should reconsider the use of rational chip seal design methodologies rather than relying on trial and error or in-house experiences. The presented approach provides a consistent and uniform method to ensure a successful pavement performance. Rational methodologies offer custom designs that can address a multitude of different projects, field conditions, and material properties.
On the design of three-dimensional mechanical metamaterials using load flow visualization
Published in Mechanics Based Design of Structures and Machines, 2022
Sree Kalyan Patiballa, Girish Krishnan
Approaches for the design of mechanical metamaterials in literature can be broadly classified into insightful approaches and computational approaches. Insightful approaches use the rational intuition of the designer to design mechanical metamaterials. The realization of negative Poisson’s ratio by Lakes (1987) in foam structures fueled the field of mechanical metamaterials, specifically auxetic materials. A novel mechanism of missing ribs in foams leads to negative Poisson’s ratio according to Smith, Grima, and Evans (2000). Cherkaev (1995) proposed that the combination of isotropic compliant and rigid phases can lead to mechanical metamaterials. The rational design approaches, though intuitive, are difficult to generalize to any design problem. Computational approaches such as structural topology optimization, reconciled level sets, bi-directional evolutionary optimization (BESO) are used to design mechanical metamaterials. Taking inspiration from the seminal work by Sigmund (1994, 1995), many other researchers have published on the design of microstructures with extreme properties (Xia and Breitkopf 2015; Bendsøe and Kikuchi 1988; Theocaris and Stavroulakis 1998). While computational methods are mathematically robust, they are time-consuming, sensitive to the algorithm used and the obtained solutions may require extensive postprocessing to be practical. In some cases, the process may yield limited user insight. In this paper, we propose an alternative two-phase design methodology to tackle these challenges. In the first phase, we obtain conceptual designs that determine the topology of the unit cell microstructure using a kinetostatic building block-based design approach. In the second phase of design refinement, a shape/size optimization is performed on the conceptual topology to meet any given effective elastic properties and conform to manufacturing requirements. This process differs from SIMP-based structural topology optimization by offering the user control of the creative part of the design, while offsetting the more tedious phase to a computational shape-size refinement process. With the conceptual feasible topology determined in the first phase, the computational expensiveness for the second phase drastically reduces, leading to an overall robust framework. The two phase process is not entirely a new concept and has been featured in the design of compliant or deformable mechanisms by Joo, Kota, and Kikuchi (2000) and Joo and Kota (2004). The insightful phase for topology generation has been accomplished by instant center kinematics in planar space by Kim, Kota, and Mo-Moon (2006) to more recently a screw-theory based projective geometry scheme in three-dimensional (3D) domain by Hopkins and Culpepper (2010) and Su, Dorozhkin, and Vance (2009). Several refinement-based algorithms have been proposed to tune the base topology to match several secondary considerations such as stiffness, strength and manufacturability (Hetrick and Kota 1999; Saxena and Ananthasuresh 2001; Krishnan, Kim, and Kota 2013a; Patiballa and Krishnan 2017a). Since the functionality of both compliant mechanisms and mechanical metamaterials rely on the elastic deformation of its constituent members, we believe that a two-phase insightful approach and its benefits must translate to metamaterial design as well.