Convolutional Filtering in Simplicial Complexes

This paper proposes convolutional filtering for data whose structure can be modeled by a simplicial complex (SC). SCs are mathematical tools that not only capture pairwise relationships as graphs but account also for higher-order network structures. These filters are built by following the shift-and-sum principle of the convolution operation and...

Bonding Process of Copper Foam-Silver Composite and Performance Characterization of the Joint

As a key heat-dissipating and electrical interconnecting component in high-temperature power modules, die-attach and substrate-attach layers play an important role in effectively reducing the thermal resistance and improving the long-term reliability. Traditional substrate-attach materials limit the high-temperature applications of packaging...

Markov Modulated Process to Model Human Mobility

We introduce a Markov Modulated Process (MMP) to describe human mobility. We represent the mobility process as a time-varying graph, where a link specifies a connection between two nodes (humans) at any discrete time step. Each state of the Markov chain encodes a certain modification to the original graph. We show that our MMP model...

Topological Volterra Filters

To deal with high-dimensional data, graph filters have shown their power in both graph signal processing and data science. However, graph filters process signals exploiting only pairwise interactions between the nodes, and they are not able to exploit more complicated topological structures. Graph Volterra models, on the other hand, are also...

Finite Impulse Response Filters for Simplicial Complexes

In this paper, we study linear filters to process signals defined on simplicial complexes, i.e., signals defined on nodes, edges, triangles, etc. of a simplicial complex, thereby generalizing filtering operations for graph signals. We propose a finite impulse response filter based on the Hodge Laplacian, and demonstrate how this filter can be...

Human activity classification with radar signal processing and machine learning

As the number of older adults increases worldwide, new paradigms for indoor activity monitoring are required to keep people living at home independently longer. Radar-based human activity recognition has been identified as a sensing modality of choice because it is privacy-preserving and does not require end-users compliance or manipulation. In...

Node varying regularization for graph signals

While regularization on graphs has been successful for signal reconstruction, strategies for controlling the bias-variance trade-off of such methods have not been completely explored. In this work, we put forth a node varying regularizer for graph signal reconstruction and develop a minmax approach to design the vector of regularization...

Visualised Frames: How Sketching Influences Framing Behaviour in Design Teams

Framing is a crucial skill for connecting problem and solution spaces in the creative design process, both for individuals and teams. Frames are implicit in individuals’ cognitive thinking, but the creation of shared frames plays a vital role in collaborative design. Many studies have attempted to describe the framing process, but little is...

Whole failure process analysis for jointed rock masses based on coupling method of DDA and FEM

The elastic-plastic mechanical behaviour is a typical characteristic of rock mass. The load action will bring on the local destruction, large deformation, even whole failure of rock mass with the discontinuous mediums (e.g. joint, crack and fault). It is a coupling process of the continuous deformation and the discontinuous deformation. The...