• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.163-177
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• 2019

As smartphones are getting widely used, human activity recognition (HAR) tasks for recognizing personal activities of smartphone users with multimodal data have been actively studied recently. The research area is expanding from the recognition of the simple body movement of an individual user to the recognition of low-level behavior and high-level behavior. However, HAR tasks for recognizing interaction behavior with other people, such as whether the user is accompanying or communicating with someone else, have gotten less attention so far. And previous research for recognizing interaction behavior has usually depended on audio, Bluetooth, and Wi-Fi sensors, which are vulnerable to privacy issues and require much time to collect enough data. Whereas physical sensors including accelerometer, magnetic field and gyroscope sensors are less vulnerable to privacy issues and can collect a large amount of data within a short time. In this paper, a method for detecting accompanying status based on deep learning model by only using multimodal physical sensor data, such as an accelerometer, magnetic field and gyroscope, was proposed. The accompanying status was defined as a redefinition of a part of the user interaction behavior, including whether the user is accompanying with an acquaintance at a close distance and the user is actively communicating with the acquaintance. A framework based on convolutional neural networks (CNN) and long short-term memory (LSTM) recurrent networks for classifying accompanying and conversation was proposed. First, a data preprocessing method which consists of time synchronization of multimodal data from different physical sensors, data normalization and sequence data generation was introduced. We applied the nearest interpolation to synchronize the time of collected data from different sensors. Normalization was performed for each x, y, z axis value of the sensor data, and the sequence data was generated according to the sliding window method. Then, the sequence data became the input for CNN, where feature maps representing local dependencies of the original sequence are extracted. The CNN consisted of 3 convolutional layers and did not have a pooling layer to maintain the temporal information of the sequence data. Next, LSTM recurrent networks received the feature maps, learned long-term dependencies from them and extracted features. The LSTM recurrent networks consisted of two layers, each with 128 cells. Finally, the extracted features were used for classification by softmax classifier. The loss function of the model was cross entropy function and the weights of the model were randomly initialized on a normal distribution with an average of 0 and a standard deviation of 0.1. The model was trained using adaptive moment estimation (ADAM) optimization algorithm and the mini batch size was set to 128. We applied dropout to input values of the LSTM recurrent networks to prevent overfitting. The initial learning rate was set to 0.001, and it decreased exponentially by 0.99 at the end of each epoch training. An Android smartphone application was developed and released to collect data. We collected smartphone data for a total of 18 subjects. Using the data, the model classified accompanying and conversation by 98.74% and 98.83% accuracy each. Both the F1 score and accuracy of the model were higher than the F1 score and accuracy of the majority vote classifier, support vector machine, and deep recurrent neural network. In the future research, we will focus on more rigorous multimodal sensor data synchronization methods that minimize the time stamp differences. In addition, we will further study transfer learning method that enables transfer of trained models tailored to the training data to the evaluation data that follows a different distribution. It is expected that a model capable of exhibiting robust recognition performance against changes in data that is not considered in the model learning stage will be obtained.

• Korean Journal of Psychosomatic Medicine
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• v.10 no.2
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• pp.110-119
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• 2002

Objectives : Numbers of patients who have chronic pain seem to be increasing in the psychiatric practice. Many investigators have used models of stress and coping to help explain the differences in adjustment found among persons who experience chronic pain. Coping strategies appear to be associated with adjustment in chronic pain patients. The objectives of this study were to develop a self-report questionnaire which is the most widely used measures of pain coping strategies, Coping Strategies Questionnaire (CSQ) into Korean version and to study the different coping strategies with which chronic pain patients frequently use when their pain reaches a moderate or greater level of intensity. Methods : One hundred twenty-eight individuals with chronic pain conditions and two hundred fifty-two normal controls were administered the Korean version-Coping Strategies Questionnaire(KCSQ) to assess the frequency of use and perceived effectiveness of a variety of cognitive and behavioral pain coping strategies. We also obtained their clinical features in chronic pain patients. Reliability of the questionnaire were analyzed and evaluated differences of coping strategies between two groups. Results : Data analysis revealed that the questionnaire was internally reliable. Chronic pain patients reported frequent use of a variety of pain coping strategies, such as coping self-statements, praying and hoping, catastrophizing, and increase behavior scales which were higher compared to the normal controls. Conclusion: K-CSQ revealed to be a reliable self-report questionnaire which is useful for the assessment of coping strategies in clinical setting on chronic pain. And analysis of pain coping strategies may be helpful in understanding pain for chronic pain patients. The individual K-CSQ may have greater utility in terms of examining coping, appraisals, and pain adjustment. A consideration of pain coping strategies may allow one to design pain coping skills training interventions so as to fit the individual chronic pain patient. Further research is needed to determine whether cognitive-behavioral intervention designed to decrease maladaptive coping strategies can reduce pain and improve the physical and psycho-social functioning of chronic patients.