Published papers

User experience (UX) evaluation is critical for identifying user requirements and mitigating the risk of product failure during the development of interactive systems. This paper presents Dual-Track UX, a specialized UX evaluation method designed to address three key challenges in evaluating the UX of Business-to-Business (B2B) Software-as-a-Service (SaaS) products: (a) diversified user goals and operational patterns, (b) limited access to external users, and (c) the necessity for long-term evaluation. Dual-Track UX integrates heuristic evaluation, Goals-Signals-Metrics process, exploratory testing, and service design tools into a cohesive dual-track workflow. Track 1 identifies and prioritizes usability issues in the user interface, while Track 2 constructs UX metrics and monitors the effectiveness of user goal achievement over time. Preliminary validation through expert interviews highlighted the advantages, limitations, challenges in adoption, and opportunities for further refinement, paving the way for its broader application in B2B SaaS development.

This research explores how Service Dominant Logic (SDL) can be effectively integrated into Human-Computer Interaction (HCI) design processes. While service design has gained interest in HCI, it remains primarily limited to interaction-level dimensions rather than system-level concepts. Through two case studies in elderly care and healthcare facilities in Japan, we demonstrate practical methods for incorporating SDL's key concepts—actor networks, service exchange, resource integration, and institutions—into the Human-Centered Design process. Our findings show that mapping actor networks helps identify appropriate service providers, analyzing service exchanges informs value proposition decisions, understanding resource integration assesses actors' interaction capabilities, and identifying institutions ensures contextually appropriate services. The integration of SDL concepts enables more holistic service design that extends beyond interaction-level concerns to address collaborative networks and ecosystem dimensions. This approach contributes to developing more effective and sustainable service systems that better serve both providers and beneficiaries.

Robotic automation is expected to be applicable in various fields. The utilization of robots requires human-robot interaction (HRI) for prolonged direct manipulation or learning. Recently, numerous studies on HRI have been conducted in virtual space using virtual, augmented, and mixed reality (VAM-HRI). In the future, VAM-HRI applications are expected to involve users wearing head-mounted displays (HMDs). However, HMDs present various problems, such as vergence and accommodation conflict (VAC) caused by eye strain, and thus cannot be used for long periods. In this study, a remote robot operation interface is developed to solve this problem. Experiments are conducted from the viewpoint of ophthalmology to determine whether 'removal of VAC' and 'improvement of depth perception' by Light Field HMDs (LFHMD), and 'reduction of eye strain' by TransRay are feasible. The results reveal that the LFHMD is superior to the general HMDs for all items.

Designers for the BOP have to consider "field", "interest" and "sustainability." First, the fields at the BOP are totally different because a variety of macro and micro elements differ. Also, there is a high possibility that a product may collapse a balance that has been kept without the developed countries. The author adopted Structural-Constructivism as a theoretical framework to develop a framework. This design framework is composed of 4 original tools. "The Designers Interest Model" is a tool for designers to relativize their interests without the frame of thinking. "The Phenomena Map" is a tool for designers to visualize the phenomena in the field and to construct structures considering the interests of the locals. "The Abduction Model" is a tool for designers to design concepts of products that satisfy the interests of the locals. "The Sustainability Model" is a tool to design a system related to environmental, economic, and social sustainability centered on the prototypes of the products.