All-memristive neuromorphic computing with level-tuned neurons

In the new era of cognitive computing, systems will be able to learn and interact with the environment in ways that will drastically enhance the capabilities of current processors, especially in extracting knowledge from vast amount of data obtained from many sources. Brain-inspired neuromorphic computing systems increasingly attract research interest as an alternative to the classical von Neumann processor architecture, mainly because of the coexistence of memory and processing units. In these systems, the basic components are neurons interconnected by synapses. The neurons, based on their nonlinear dynamics, generate spikes that provide the main communication mechanism. The computational tasks are distributed across the neural network, where synapses implement both the memory and the computational units, by means of learning mechanisms such as spike-timing-dependent plasticity. In this work, we present an all-memristive neuromorphic architecture comprising neurons and synapses realized by using the physical properties and state dynamics of phase-change memristors. The architecture employs a novel concept of interconnecting the neurons in the same layer, resulting in level-tuned neuronal characteristics that preferentially process input information. We demonstrate the proposed architecture in the tasks of unsupervised learning and detection of multiple temporal correlations in parallel input streams. The efficiency of the neuromorphic architecture along with the homogenous neuro-synaptic dynamics implemented with nanoscale phase-change memristors represent a significant step towards the development of ultrahigh-density neuromorphic co-processors.

On the Symbiosis of People and Building

Sytse de Maat

Controversies continue to exist between architects and the public about what is a good building. High-style modern architecture is often disliked by the public. Moreover, in everyday life people blame the architect for everything they find impractical in a building. The non-operable window is emblematic of this controversy. The kernel of the problem lies in the lack of knowledge about how people relate to their buildings. This thesis investigates the relationship between people and their buildings, a topic that lies on the interface of architecture, psychology, and anthropology. In architecture, many have attempted to create buildings that feel alive, although much of what is built today feels alien to those who inhabit it. Environmental psychology has its focus on perception and meaning, whereas in anthropology, the habitat is often observed in a cultural perspective. This thesis aims at building theory that connects the insights of these disciplines. The importance of the topic lies in the increasing alienation of people from their buildings. Although many architects work on buildings that we can better relate to, alienation and disconnection continue to exist because, to mention one aspect, the built environment is made by more people than only architects. In the multidisciplinary world, improvement of the relationship of people and building would surely benefit from the introduction of a clear focal point and an adequate conceptual framework. From literature, insights were collected that explain the relationship in four perspectives: human aspects, properties of buildings, its relation to society, and abstract systems. Together they form a model that can serve as the focal point. Next, in order to identify what is changing in the relationship, the model was used as research tool in different contexts, ranging from vernacular to modern. Fieldwork research was conducted in traditional habitats, state-of-the-art modern buildings, and settings in between: primitive housing in urban slum or informal settlement. Detailed research methods for the survey of people's interaction with buildings were newly developed in the field and combined with existing sampling and coding techniques. Architects tools like sketches, scale models, and photography were used next to interviews and participatory observation. Results are presented in several reports ranging from slum dwellings to hi-tech. Besides architecture, they describe the practice of everyday life, logic and inconsistencies in building methods, and effects on the people-building relationship. From the findings, we concluded that what happened to the people-building relationship in the transition from vernacular to modern could be described in five trends. These trends explain the current disconnection as well as the difficulties we face in creating live buildings. Thus, together with the focal point, a conceptual framework is created holding the patterns typical of the people-building relationship. This knowledge can be used as both tool and theory by the profession. The research suggests that in order to create a strong people-building relationship, the whole process of building, dwelling, and daily operation must be focused on inclusion of the end-user. Today's technology and regulations favor exclusion and therefore contribute to a built environment that is not humanly sustainable.

EPFL2015

Conduit, Patio, Waste: Mapping Environmental Relations in Bairro da Malagueira

Bárbara Maçães E Costa

The ongoing ecological crisis is reframing the common binary opposition between architecture and nature and provoking us to ask what kinds of buildings we collectively want to create for the ecosystems that we inhabit. The environment is not a neutral background, a natural scenery, or a container of pre-social resources; and architecture is not a collection of objects floating in a vacuum. Buildings and landscapes constitute each other dialectically. The environmental question in Western architecture had a peak moment during the contextualism debates of the 1950s and 60s, in the UK and Italy. They equated context with ideas such as ecological urbanism and habitat, or preesistenze ambientali and continuita . But by the 1970âs there was a shift from a sort of socio-biological determinism towards a more culturalist approach. Context became synonymous with historical context, and site-specificity was to be achieved less through a dialectical interplay with material reality than through a referential, typo-morphological approach. Gradually, a rift emerged: ecology became a matter of natural fact to be technologically calculated, and context became a matter of cultural identity to be narrated and deconstructed. From this point onwards, and in tandem with the rise of neoliberal commodification and its correlate ideology of postmodernism, Western architecture lost the ability to tackle the environmental question beyond the narrow scope of the individual architectural object. Before this split, the modernist tradition had attempted to address the built environment, and housing projects in particular, as a socio-ecological totality. Backed by large-scale funding initiatives from social-democratic states, human and non-human life could be understood dialectically, with the neighbourhood scale functioning as a mediating unit between the individual and the social. Alvaro Siza's Bairro da Malagueira was one of the last projects of this generation. It emerged from the very particular conditions of the 1974/75 Carnation Revolution and the state-sponsored housing program SAAL, a dual power structure made up of construction technical brigades and neighbourhood committees. During this process, the SAAL-Norte produced a series of projects focused on reinventing the typology of the ilha, and Alvaro Siza wrote a text considering the hypothesis of the proletarian island as basic element of the urban tissue. What was taken from these islands was less their stylistic or typological configuration than the system of environmental relations that they fostered, predicated on a series of threshold spaces and open interiorities. From Bairro da Malagueira, this thesis proposes a method for mapping environmental relations in architecture. It does so by identifying a series of thresholds, namely the conduit, the patio, and the waste, understood as structures that convert space into bounded associations, mediating between inside and outside, foreground and background, architecture and nature. Each threshold acts as a time-space frame with a specific magnitude of approximation, and each internalizes sets of social relations, such as class, gender and race, with corresponding modes of environmental production, namely the hidden backgrounds of territory, domesticity, and wilderness. Bairro da Malagueira hence becomes a template through which this thesis explores a dialectical understanding of architecture as an agent of environmental history.

EPFL2021

Interpretable Social Anchors for Human Trajectory Forecasting in Crowds

Alexandre Massoud Alahi, Parth Ashit Kothari, Brian Alan Sifringer

Human trajectory forecasting in crowds, at its core, is a sequence prediction problem with specific challenges of capturing inter-sequence dependencies (social interactions) and consequently predicting socially-compliant multimodal distributions. In recent years, neural network-based methods have been shown to outperform hand-crafted methods on distance-based metrics. However, these data-driven methods still suffer from one crucial limitation: lack of interpretability. To overcome this limitation, we leverage the power of discrete choice models to learn interpretable rule-based intents, and subsequently utilise the expressibility of neural networks to model scene-specific residual. Extensive experimentation on the interaction-centric benchmark TrajNet++ demonstrates the effectiveness of our proposed architecture to explain its predictions without compromising the accuracy.