Owing to the recent proliferation of smartphones and the SNS, a large number of images taken by smartphones at various places have been uploaded to SNSs. In addition, smartphones are equipped with various sensors such as Wi-Fi modules that enable us to generate an image associated with the sensory information that represents the context in which the image was captured. This study demonstrates the benefits of images associated with Wi-Fi signals in the automated construction of a Wi-Fi-based indoor logical location classifier that predicts a semantic location label of a user’s position for shopping complexes. In this study, a logical location class refers to the store class label in a shopping complex, such as Starbucks and H&M. Given a collection of images associated with Wi-Fi signals taken at a shopping complex and the complex’s floor plan, the proposed method first estimates the store label at which an image was taken by analyzing the image and crawled online images of branch stores. Then, the 2D coordinates of the images taken at branch stores on the floor coordinate system can be estimated using the floor plan. Subsequently, by using the Wi-Fi signals of the branch store images and their estimated 2D coordinates, we construct a transformation function that maps Wi-Fi signals onto the 2D coordinates, and we adopt this function to predict an indoor location class of an observed Wi-Fi scan from a smartphone possessed by an end user. The proposed transformation function comprises an ensemble of sub-functions designed based on CVAEs. Finally, we demonstrate the effectiveness of the proposed method for three actual shopping complexes.

This paper presents a new human activity recognition method that uses a camera mounted on a mobile robot. We assume that the robot's camera captures images of a person and recognizes his/her activities based on skeletal and visual features extracted from the images. A key issue encountered with this method for activity recognition is that it requires the robot to position itself so that it has an adequate field of view of the activities being conducted. For example, if the robot is directly behind a person while observing that person making tea, it will be difficult for the robot to distinguish that activity from other similar activities such as preparing a meal or washing dishes. Our method employs deep reinforcement learning to control the movements of the mobile robot that is observing the activities in order to maximize its recognition accuracy while minimizing its energy consumption related to its movement. We propose effective action- and state-space designs that can achieve early training convergence and highly accurate activity recognition by: (i) incorporating the confidence of the activity recognition output when evaluating the quality of the current state (position), (ii) incorporating the costs of subsequent actions when estimating values for those actions, and (iii) designing an effective action space that accelerates reinforcement learning by restricting the movement space of the robot to the circumference of a circle with a predefined radius centered on the person.

This paper presents a new method for evaluating tooth brushing performance using audio collected from a smartphone. To do this, we use hidden Markov models (HMMs) to recognize audio data that include various types of tooth brushing actions, such as brushing the outer surface of the front teeth and brushing the inner surface of the back teeth. We then use the output of the HMMs to build regression models to estimate tooth brushing performance scores, such as stroke quality of brushing for the back inner teeth and duration of brushing for the front teeth. The scores used to train these regression models are obtained from a dentist who specializes in dental care instruction, with the resulting regression models estimating performance scores that closely correspond to the scores assigned by the dentist.

Transdisciplinary research is a rapidly expanding part of science and engineering, demanding new methods for connecting results across fields. In biomedicine for example, modeling complex biological systems requires linking knowledge across multiple levels of science, from genes to disease. The move to multilevel research requires new strategies; in this paper we present path knowledge discovery, a novel methodology for linking published research findings. Path knowledge discovery consists of two integral tasks: 1) association path mining among concepts in a multipart lexicon that crosses disciplines, and 2) fine-granularity knowledge-based content retrieval along the path(s) to permit deeper analysis. Implementing this methodology has required development of innovative measures of association strength for pairwise associations, as well as the strength for sequences of associations, in addition to powerful lexicon-based association expansion to increase the scope of matching. In our discussions, we describe the validation of the methodology using a published heritability study from cognition research, and we obtain comparable results. We show how path knowledge discovery can greatly reduce a domain expert's time (by several orders of magnitude) when searching and gathering knowledge from the published literature, and can facilitate derivation of interpretable results.