Search

We extend Clarkson's framework by considering parameterized convex optimization problems over the unit simplex, that depend on one parameter. We provide a simple and efficient scheme for maintaining an e-approximate solution (and a corresponding e-coreset) along the entire parameter path. We prove correctness and optimality of the method. Practically relevant instances of the abstract parameterized optimization problem are for example regularization paths of support vector machines, multiple kernel learning, and minimum enclosing balls of moving points.

Monitoring of health parameters in non-clinical settings is one strategy to address the increasingly aging population and age-related disabilities and diseases. However, challenges exist when introducing self-monitoring activities in people's everyday life. An active lifestyle can challenge the appropriation of healthcare technologies and people with comorbidity may have diverse but co-existing monitoring needs. In this paper, we seek to understand home-based health monitoring practices to better design and integrate them into people's everyday life. We perform an analysis of socio-technical complexities in home-based healthcare technologies through three case studies of self-monitoring: 1) pre-eclampsia (i.e. pregnancy poisoning), 2) heart conditions, and 3) preventive care. Through the analysis seven themes emerged (people, resources, places, routines, knowledge, control and motivation) that can facilitate the understanding of home-based healthcare activities. We present three modes of self-monitoring use and provide a set of design recommendations for future Ubicomp designs of home-based healthcare technology. Monitoring of health parameters in non-clinical settings is one strategy to address the increasingly aging population and age-related disabilities and diseases. However, challenges exist when introducing self-monitoring activities in people’s everyday life. An active lifestyle can challenge the appropriation of healthcare technologies and people with comorbidity may have diverse but co-existing monitoring needs. In this paper, we seek to understand home-based health monitoring practices to better design and integrate them into people’s everyday life. We perform an analysis of socio-technical complexities in home-based healthcare technologies through three case studies of self-monitoring: 1) pre-eclampsia (i.e. pregnancy poisoning), 2) heart conditions, and 3) preventive care. Through the analysis seven themes emerged (people, resources, places, routines, knowledge, control and motivation) that can facilitate the understanding of home-based healthcare activities. We present three modes of self-monitoring use and provide a set of design recommendations for future Ubicomp designs of home-based healthcare technology.

In this paper we present Local Area Artworks, a system enabling collaborative art interpretation on-site deployed during an exhibition in a local art gallery. Through the system, we explore ways to re-connect people to the local place by making use of their personal mobile devices as interfaces to the shared physical space. We do this by re-emphasizing the local characteristics of wireless networks over the global connectivity to the Internet. With a collaborative writing system in a semi-public place, we encourage local art discussions and provide a platform for the public to actively participate in interpretations of individual artworks. Our preliminary findings suggest that people were (to our surprise) not questioning the inner workings of our system. Through engaging with the system, individuals felt being part of the exhibition. However, no coherent piece of text emerged during the runtime of the exhibition. In this paper we present Local Area Artworks, a system enabling collaborative art interpretation on-site deployed during an exhibition in a local art gallery. Through the system, we explore ways to re-connect people to the local place by making use of their personal mobile devices as interfaces to the shared physical space. We do this by re-emphasizing the local characteristics of wireless networks over the global connectivity to the Internet. With a collaborative writing system in a semi-public place, we encourage local art discussions and provide a platform for the public to actively participate in interpretations of individual artworks. Our preliminary findings suggest that people were (to our surprise) not questioning the inner workings of our system. Through engaging with the system, individuals felt being part of the exhibition. However, no coherent piece of text emerged during the runtime of the exhibition.

We devise a framework for computing an approximate solution path for an important class of parameterized semidefinite problems that is guaranteed to be e-close to the exact solution path. The problem of computing the entire regularization path for matrix factorization problems such as maximum-margin matrix factorization fits into this framework, as well as many other nuclear norm regularized convex optimization problems from machine learning. We show that the combinatorial complexity of the approximate path is independent of the size of the matrix. Furthermore, the whole solution path can be computed in near linear time in the size of the input matrix. The framework employs an approximative semidefinite program solver for a fixed parameter value. Here we use an algorithm that has recently been introduced by Hazan. We present a refined analysis of Hazan's algorithm that results in improved running time bounds for a single solution as well as for the whole solution path as a function of the approximation guarantee.