Towards Learning Discrete Representations via Self-Supervision for Wearables-Based Human Activity Recognition

Human activity recognition (HAR) in wearable computing is typically based on direct processing of sensor data. Sensor readings are translated into representations, either derived through dedicated preprocessing, or integrated into end-to-end learning. Independent of their origin, for the vast majority of contemporary HAR, those representations are typically continuous in nature. That has not always been the case. In the early days of HAR, discretization approaches have been explored - primarily motivated by the desire to minimize computational requirements, but also with a view on applications beyond mere recognition, such as, activity discovery, fingerprinting, or large-scale search. Those traditional discretization approaches, however, suffer from substantial loss in precision and resolution in the resulting representations with detrimental effects on downstream tasks. Times have changed and in this paper we propose a return to discretized representations. We adopt and apply recent advancements in Vector Quantization (VQ) to wearables applications, which enables us to directly learn a mapping between short spans of sensor data and a codebook of vectors, resulting in recognition performance that is generally on par with their contemporary, continuous counterparts - sometimes surpassing them. Therefore, this work presents a proof-of-concept for demonstrating how effective discrete representations can be derived, enabling applications beyond mere activity classification but also opening up the field to advanced tools for the analysis of symbolic sequences, as they are known, for example, from domains such as natural language processing. Based on an extensive experimental evaluation on a suite of wearables-based benchmark HAR tasks, we demonstrate the potential of our learned discretization scheme and discuss how discretized sensor data analysis can lead to substantial changes in HAR

Tree diversity and species identity effects on soil fungi, protists and animals are context dependent

Plant species richness and the presence of certain influential species (sampling effect) drive the stability and functionality of ecosystems as well as primary production and biomass of consumers. However, little is known about these floristic effects on richness and community composition of soil biota in forest habitats owing to methodological constraints. We developed a DNA metabarcoding approach to identify the major eukaryote groups directly from soil with roughly species-level resolution. Using this method, we examined the effects of tree diversity and individual tree species on soil microbial biomass and taxonomic richness of soil biota in two experimental study systems in Finland and Estonia and accounted for edaphic variables and spatial autocorrelation. Our analyses revealed that the effects of tree diversity and individual species on soil biota are largely context dependent. Multiple regression and structural equation modelling suggested that biomass, soil pH, nutrients and tree species directly affect richness of different taxonomic groups. The community composition of most soil organisms was strongly correlated due to similar response to environmental predictors rather than causal relationships. On a local scale, soil resources and tree species have stronger effect on diversity of soil biota than tree species richness per se

Cultural Diversity & Adaptation: The Archaic, Anasazi, & Navajo Occupation of the Upper San Juan Basin

Recent work in the upper San Juan Basin has more than doubled the number of known, as well as excavated, sites. Without exception, this work has modified and expanded long-held views of the PaleoIndian, Archaic, Anasazi, and Navajo people who inhabited the area. The papers presented in this volume reflect these changes and represent the cutting edge of southwestern archaeology

Trust in client-service provider relationships

In the age of rapidly changing and competitive environments, companies are forced to build strong and long-lasting relationships with their customers. Over the last decades, marketing theory and practice developed a plethora of attempts to describe relevant factors, underlying correlations and complex constructs, explaining the relationship between buyer and seller. For several disciplines, which are part of, describe or influence the relationship between buyer and seller such as a) marketing, b) customer purchase behaviour and c) sales management and personal selling, it appears that trust has a strong impact and therefore is an important variable for building long-lasting relationships. Although there is an extensive source of literature available on appropriate response to trust and its influence on buyer seller relationships, few of these writings contain guidance specifically related to financial services. The objectives of this study are I) to determine general differences regarding the impact of trust in a finance and insurance advice setting, ii) to determine difference of the general importance of trust towards three dimensions, iii) to analyse through which antecedents client-trust is build towards these three dimensions and iv) to identify the role of trust in future interactions between a financial service company and its clients. To achieve these objectives, quantitative research was undertaken in Germany by conducting a mail survey to 1.394 existing clients of an independent financial advisory institution. The phases of research cover a broad literature review combined with informal background research to identify variables that build trustlinvoke the trust building process to examine differences and/or additional variables to the descriptions in the literature. Prospective clients seem to generally support variables provided by the literature findings. The main research phase involves a mail survey to 1.394 existing clients with 321 responses. It is aimed at identifying relevant answers to the issues i)-iv) as described above. The results of the mail survey suggest differences between different client segments according to e. g. their educational background as well as their stage on the life cycle of financial services. Additionally, to validate the empirical findings, interviews were performed with 20 independent financial advisors which are aimed at identifying relevant answers to the above mentioned issues ii)-iv) from an advisor's point of view. The results suggest differences within the group of advisors according to e. g. demographic criteria. The results indicate that trust seems to be an important factor for the relationship between client, advisor and financial service provider.N evertheless,d ifferencesc oncerningt he influenceo f trust on the interpersonal relationship between the client and the financial advisor as well as its influence on the organisational relationship between client and financial service organisation can be observed and have to be addressed in the future. Moreover, also the differences related to the relevance of trust for the internal relationship between the financial service advisor and its organisation needs further attention. A framework of three dimensions of relationship marketing activities is introduced which may assist financial service companies to Implement a trust based relationship marketing approach. This should cover 1) an internal relationship marketing dimension, ii) an external relationship marketing dimension and iii) an interactive relationship marketing dimension. As a result, the company should become more trustworthya nd further more be enabledt o build strongerr elationshipsw ith their clients.Finanzund Versicherungsmakler GmbH, MOnster Str. 111,48155 MOnster, German

Active Materials

What is an active material? This book aims to redefine perceptions of the materials that respond to their environment. Through the theory of the structure and functionality of materials found in nature a scientific approach to active materials is first identified. Further interviews with experts from the natural sciences and humanities then seeks to question and redefine this view of materials to create a new definition of active materials