Docta Manus Drawing Structures, UE GC EPFL Lausanne

Drawing constitutes a very powerful and critical tool of conceptual design. Drawing constructs thought, it acts as a communication interface between the work and the mind and between different disciplines; it is the most powerful language of communication in the working together between architects and engineers. The UE ’Docta Manus - Drawing Structures’ introduces the basic drawing techniques: sketch, plan, section, elevation, axonometry, perspective. Based on these techniques, we further investigate analytical drawing methods capable of exploring structural concepts and their architectural solutions. Through hand drawing we analyze selected projects that embody an exemplary interplay of architecture and civil engineering, as e.g. the work of Mies van der Rohe, Luis Kahn / August Komendant, Jean Prouvé and Luigi Nervi. Our main focus lies on the load bearing structure and its tectonic and spatial articulation as common intersection between architecture and engineering. Through analysis, students enter into dialogue with construction in a direct way. They get a sense for the adequacy of tools and refinements of solutions. We investigate proportion, material innovation and tectonic articulation in relation to the structural idea and become aware of the importance of detail. Analysis takes apart and makes transparent the parameters and dependencies of the design process and opens the work into a condition of possibility. We draw by hand, as this is the most direct and immediate way of becoming aware of technique in relation to intention as it forces to take decisions. Drawing by hand is a cognitive process where the dynamic relation between doing and thinking is essential. That is why ‘the more you draw, the more you see’ and vice versa. The learning hand builds up tacit knowledge. The construction of points and lines on a sheet of paper sensitizes students to the notions of scale, size, proportion, transparency and composition; it makes them aware of the importance of detail as a key moment of construction, as a mediator relating a structure to the perceiving subject. This first publication shows a selection of 24 working drawings from an atelier of 30 students in civil engineering and architecture that took place during the autumn semester 2020 at EPFL. The students each analyzed one out of five selected projects of Mies van der Rohe, exploring adequate scales, drawing types and techniques to understand the project’s structure and construction principles. The drawings thus include dimensioning and fabrication notes up to catalogue of elements, mounting principles and sequence. The careful construction of layers of information by hand builds up into tactile working drawings that embody the spatial and tectonic ideas as well as the construction process of a structure. These ‘meta-drawings’ allow the observing eye to survey from one detail to another in a synchronous manner while integrating all information into a mental construction.

Structures that adapt to loads through large shape changes: design and optimization

Arka Prabhata Reksowardojo, Gennaro Senatore, Ian Smith

The construction industry is a major contributor to the consumption of mined material resources and to the global energy demand. It is thus important to consider energy and material efficiency criteria for the design of civil structures. Through sensing and actuation, structures can adapt their geometry and internal forces in order to maintain optimal performance during service life. Previous work has shown that well designed adaptive structures achieve substantial whole-life energy savings compared with passive structures. Whole-life energy consists of an embodied part in the material and an operational part for structural adaptation. This paper presents a new method to design structures that adapt to loads through large shape changes in order to redistribute stresses and thus to minimize material utilization. This method consists of two parts: (1) shape optimization is employed to obtain shapes that are optimal under each load case. This way extreme loads that typically have long return periods do not govern the design. (2) Stochastic search combined with the nonlinear force method (NFM) is employed to obtain an optimal actuation system that is able to control the structure into the target shapes obtained in (1). A 3D-truss roof structure is taken as a case study to illustrate the design process.

Taylor & Francis2019

Cognitive language engineering towards robust human-computer interaction

Vincenzo Pallotta

Intelligent information processing seems to be one of the most challenging task among those involved in human-computer interaction. A central issue is how to model the various types of interaction among artificial and natural entities at different levels of abstraction. On the one hand, models of interaction are required to better understand the communication phenomena. On the other, suitable languages and paradigms should provide powerful frameworks for developing computer-based applications. In this dissertation I focus on different aspects of the second problem, trying to develop a methodology for the design of interactive natural language applications (e.g. from question-answering to mixed-initiative dialogue). One of the main aspects I am concerned with in this work is the problem of their robustness. Several methods have been proposed for achieving robustness in natural language understanding, but these methods are sometimes hard to scale up or re-use in different applications. Moreover, they often concentrate on a single linguistic level of the processing rather than offering a global solution. I will set up a Language Engineering environment whose goal is to combine software engineering and cognitive aspects (e.g. aspects related to representation of a mental model of the speaker). Given its complexity, it is apparent that the problem can be solved only partially. I want to stress here that the main contribution of my work is a holistic perspective on the problem of natural language understanding. Rather than focusing on a particular aspect of natural language processing, I tried to benefit from the big amount of work that has been already done in Computational Linguistics and Computer Science merging different ideas and techniques. In the first part of the dissertation I explore the universe of Language Engineering in order to clarify how my contribution can be situated. After a survey on the state of the art on robust methods in analysis of natural language data, I focus on the role that Computational Logic plays in relating the syntactic and semantic analysis of natural language to its practical understanding within specific applications. Robustness is considered from two complementary perspectives, borrowing the terminology from modern software engineering: robustness "in the small" and robustness "in the large". The first perspective is discussed while presenting an application for the Interaction through Speech with Information Systems, where robust semantic parsing is used to extract queries from spoken natural language utterances.The second perspective is examplified by the re-engineering of an existing text analysis system using a new Language Engineering methodology: Agent-Oriented Language Engineering. In the second part of the thesis I discuss how cognitive aspects can be integrated into a Language Engineering environment leading to the notion of Cognitive Language Enginering. I tackle the difficult problem of robust dialogue management from both a cognitive and computational perspective. I propose two frameworks for the semantic representation and assimilation of information into the dialogue information state. The first framework allows us to represent and reason about the dynamic aspects of objects and events. The second framework is centered on the notion of mental space and it is used to build representations of the cognitive processing of information during communication.

EPFL2002

Integrally attached timber folded surface structures

Andrea Stitic

In structural engineering, folded surface structures present one of the concepts for construction of self supporting column free systems. They utilize structural benefits of folding to achieve material saving and improve structural efficiency. The folding principle can be simply described as stiffening a thin surface by placing its material further away from the axis of flexure. The application of folded surface structures in timber engineering is motivated by multiple advantages of relatively recently developed, high-performance engineered wood panel products. When used in folded systems, such panels can provide for a sustainable and lightweight solution with high load-bearing potential and high prefabrication possibilities. However, same as all timber products, these panels have limitations concerning the dimensions of the prefabricated units. These limitations are dictated by demands of transportation, assembly and, more stringently, by available manufacturing techniques. These factors influence the selection of timber structuresâ potential folded form, by constraining the dimensions of their discrete elements. Accordingly, structural forms with multiple elements along the span are needed for facilitating large spanning timber folded surface systems. Consisting of a large number of discrete plane elements, their realization requires proper edgewise connection details for ensuring an efficient load bearing system. For structures made of thin timber panels, this presents a great challenge when using the conventional joining techniques. For this reason, the use of timber folded structures for civil engineering applications has been very limited. However, recently, the re-discovery of integral mechanical attachments resulted in a new technical solution for edgewise joining of thin timber panels, which utilize digital prefabrication to integrate connectors through plate geometry. This thesis aims to facilitate the realization of large span timber folded surface structures which use one-degree-of-freedom multiple tab-and-slot joint integral mechanical attachment technique. Regarding the material, the presented work concentrates on certified Kerto-Q laminated veneer lumber panels. Taking into consideration the constraints of material, fabrication and chosen connection detail, various folded form topologies were examined for the considered application. Moreover, a relation was established between the structural form and the mentioned constraints, allowing for their implementation into the folded form design from the very start. The structural behaviour of folded systems was studied by performing extensive experimental tests. The innovative test setup developed for this purpose is presented. The results of this in-depth experimental analysis provide new insights regarding the substantial influence of the semi-rigid connection details on the global behaviour of timber folded surface structures. In addition, for analysing their feasibility, the tested structures are reviewed in terms of fabrication time, assembly and on-site construction. Furthermore, based on the experimental test results, a pertinent numerical model for predicting the load bearing behaviour of the regarded structures is provided. Using finite element method the semi-rigid structural behaviour of multiple tab-and-slot joints, as well as the entire timber folded system, was modelled with sufficient accuracy. Using the developed numerical models, a correlation is established...