Using Topic Models to Mine Everyday Object Usage Routines Through Connected IoT Sensors

With the tremendous progress in sensing and IoT infrastructure, it is foreseeable that IoT systems will soon be available for commercial markets, such as in people's homes. In this paper, we present a deployment study using sensors attached to household objects to capture the resourcefulness of three individuals. The concept of resourcefulness highlights the ability of humans to repurpose objects spontaneously for a different use case than was initially intended. It is a crucial element for human health and wellbeing, which is of great interest for various aspects of HCI and design research. Traditionally, resourcefulness is captured through ethnographic practice. Ethnography can only provide sparse and often short duration observations of human experience, often relying on participants being aware of and remembering behaviours or thoughts they need to report on. Our hypothesis is that resourcefulness can also be captured through continuously monitoring objects being used in everyday life. We developed a system that can record object movement continuously and deployed them in homes of three elderly people for over two weeks. We explored the use of probabilistic topic models to analyze the collected data and identify common patterns

Short time dynamics of molecular junctions after projective measurement

In this work, we study the short time dynamics of a molecular junction described by Anderson-Holstein model using full-counting statistics after projective measurement. The coupling between the central quantum dot (QD) and two leads was turned on at remote past and the system is evolved to steady state at time $t=0$, when we perform the projective measurement in one of the lead. Generating function for the charge transfer is expressed as a Fredholm determinant in terms of Keldysh nonequilibrium Green's function in the time domain. It is found that the current is not constant at short times indicating that the measurement does perturb the system. We numerically compare the current behaviors after the projective measurement with those in the transient regime where the subsystems are connected at $t=0$. The universal scaling for high-order cumulants is observed for the case with zero QD occupation due to the unidirectional transport at short times. The influences of electron-phonon interaction on short time dynamics of electric current, shot noise and differential conductance are analyzed

A Tale of Three Galaxies: Anomalous Dust Properties in IRASF10398+1455, IRASF21013-0739 and SDSSJ0808+3948

On a galactic scale the 9.7um silicate emission is usually only seen in type 1 active galactic nuclei (AGNs). They usually also display a flat emission continuum at ~5--8um and the absence of polycyclic aromatic hydrocarbon (PAH) emission bands. In contrast, starburst galaxies, luminous infrared (IR) galaxies (LIRGs), and ultraluminous IR galaxies (ULIRGs) exhibit a red 5--8um emission continuum, strong 10um and 18um silicate absorption features, and strong PAH emission bands. Here we report the detection of anomalous dust properties by Spitzer/Infrared Spectrograph in three galaxies (IRASF10398+1455, IRASF21013-0739 and SDSSJ0808+3948) which are characterized by the simultaneous detection of a red 5--8um emission continuum, the 9.7 and 18um silicate emission features as well as strong PAH emission bands. These apparently contradictory dust IR emission properties are discussed in terms of iron-poor silicate composition, carbon dust deficit, small grain size and low dust temperature in the young AGN phase of these three galaxies.Comment: accepted for publication in ApJ