The first ever World Happiness Report has been published recently by the United Nations, which reflects a new worldwide demand for more attention to happiness as a criterion for government policy. This also calls upon science and technology in both natural and social domains to be developed for promoting a happy and healthy lifestyle in the modern society. Therefore, research on human happiness becomes relatively important since recent developments of technologies and theories are closely related to human emotions.

In this special issue, we will focus on designing algorithms and systems for detecting and measuring the happiness of humans, especially how to enhance the experiences after users used them. Unlike other topics, which aim at detecting only human emotions, this special issue particularly concentrates on the happiness studies since happiness provides a positive direction for researchers to turn users’ negative emotions into positive ones based on recognized results.

User's behavior and biomedical signals are often used as reference information for capturing or recognizing the happiness states of humans. Such reference information includes facial expressions, emotional speech, language, body gestures, gaits, blood pressure, heartbeat rates, electroencephalograms (EEGs), electrocardiograms (ECGs), functional magnetic resonance imaging (fMRI), and so forth. This may help experts evaluate users’ emotional states and provide appropriate assistance to them in many applications. For example, an ideal affective and interactive dialogue system is capable of recognizing/measuring the happiness status of a user from his/her facial expressions, emotional speech, and language. After analysis, the system can output feedback to the user with a hearty-warmth voice or an action if this user is depressed.

This special issue hopes to bring together contributions from specialists in electrical engineering, computer science, psychological/physiological science, and medical science that will advance the state-of-the-art technology in happiness informatics. Potential topics include, but are not limited to:

• Methods for detection and measuring happiness from biomedical signals or user behavior
• Methods or human-machine interfaces for generating warming feedback to enhance human happiness status
• Research on devices, systems, or applications for happiness detection, measurement, and enhancement
• Neuroscience and cognitive research on the origin of happiness in human brains

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/tswj/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/tswj/signal.processing/dmeh/ according to the following timetable: