1 Introduction||2 Background and Motivation||3 A Method for Sensor-Based Activity Recognition in Missing Data Scenario||4 Activity Recognition Using LoRaWAN (Long Range Wide Area Network) for Nursing Care||5 Integrating Activity Recognition and Nursing Care Records||6 Exploring Human Activities Using eSense Earables||7 A Bayesian Approach for Quantifying Data Scarcity when Modeling Human Behavior via Inverse Reinforcement Learning||8 Discussion||9 Conclusion and Future Work, In this thesis, we proposed novel methods to analyze daily life activities of elderly people and quantifying data scarcity for modeling human behavior inside nursing care facilities in order to improve the overall care system. We addressed the existing challenges related to data collection, complex activity understanding and activity recognition by introducing different computational approaches that recover missing data and utilize spatial and temporal contexts of the data to achieve higher recognition accuracy in various modalities. As well as, in this thesis, we proposed a specific sample size determination method as a precursor to build more accurate models of human behavior. These proposed methods will be immensely helpful for the development of human activity recognition systems, mainly for elderly persons and nursing care facilities to improve human behavior understanding in real-life settings. The outline of the thesis is as follows: In chapter 1 and 2, we briefly introduce the thesis work and literature review. In chapter 3, we proposed a method which can improve activity recognition while having missing data without any data recovery. It is not explored or solved by others without any data imputation techniques. In our proposed approach, we explicitly induce different percentages of missing data randomly in the raw sensor data to train the model with missing data. Learning with missing data reinforces the model to regulate missing data during the classification of various activities that have missing data in the test module. This method can effectively improve the recognition accuracy from 80.8% to 97.5% in a developed synthetic dataset. Afterwards, we tested our approach with activities from two challenging benchmark datasets with a combination of 21 features. We achieved a better result of handling different levels of missing data in the dataset without any data imputation techniques. In chapter 4, we introduce activity recognition using LoRaWAN that aim to sustain connections among IoT devices over a long distance. We explored low-power wide-area network (LPWAN) technology for sensing experiment to know the possibility of using LoRaWAN protocol and network for activity recognition. As well as, investigate the number of sensor nodes connected with a single gateway which have an impact on the performance of sensors ultimate data sending capability in terms of data loss. For human activity recognition, we have achieved recognition accuracy of 94.44% by Linear Discriminant Analysis (LDA), 84.72% by Random Forest (RnF) and 98.61% by K-Nearest Neighbor (KNN) from collected data. Later, in a real nursing care setting experiment, 42 LoRaWAN sensors environmental sensors data is collected to know the data loss ratio. We observe 5% data loss happened by the sensors with a single gateway. In a simulated environment, we checked the activity recognition performance with 5%, 30%, 50% and 80% data loss environment and have found recognition accuracy of 81.94% LDA, 80.55% RnF and 91.66% by KNN while 5% data are lost. Through our proposed framework it can open a new opportunity to significantly increase the sensing range in nursing care center by LoRaWAN. In chapter 5, we assess the daily life activity data obtained during the 4-months experiments at a nursing care center. Through this work, we tried to know whether the daily life nursing care activity data are dependent on subject (e.g., staff or target resident), or date, and whether the obtained data are meaningful and informative for activity understanding. We collected 38,076 activity labels, 46,803 record details, and 2834 hours of sensor data during this experiment. From this data, we revealed the varieties and dependency of activities and care details which can be a measure of any healthcare outcome. These findings can be essential elements for activity recognition, having many intra-class relationships among activities in nursing care center. In chapter 6, we explore to recognize different types of head and mouth related activities of elderly people which can help to measure the health status. We propose an activity recognition framework to collect head and mouth related behavioral activities (e.g., head nodding, headshaking, eating and speaking) along with other regular activities. We have found that the accuracy is 93.34% by SVM, 91.92% by RnF, 91.64% by KNN, and 93.76% by CNN. In chapter 7, we proposed a sample size determination method based on uncertainty quantification (UQ) for a specific Inverse Reinforcement Learning (IRL) model of human behavior. The main insight behind our method is that the probability of model parameters given training data can be updated from prior to posterior through Bayesian inference. For illustration, we provided an example with a specific hypothetical cost scenario and decision-making rule for MS (Multiple Sclerosis) behavioral modeling, under which our method indicated 935 samples is optimal. Chapter 8 offers a brief discussion of the thesis. In Chapter 9, we conclude the thesis with conclusion and some future work issues. This thesis contribution can help to create various tools to aid stakeholders, such as domain experts and end users, in exploring human behavior understanding. This work will become particularly important with the rise of behavior-aware user interfaces that automatically reason and act in response to people’s behaviors in almost every aspect of their lives., 九州工業大学博士学位論文 学位記番号:工博甲第522号 学位授与年月日:令和3年3月25日, 令和2年度