2021 [1]

The Ergonomics of Couch Potatoes: A Study into Postures for Non-Desk Working Scenarios

Joon-Gi Shin, Daniel Saakes

IASDR '21 International Association of Societies of Design Research


In this study, we investigated how users work with a tablet in a non-desk setting. While portable computing devices have enabled ‘work anywhere’, few furniture and user interface has been designed for working in non-desk settings. In a co-exploration study, participants (n = 20) performed three tablet activities (video watching, typing, and drawing) on a configurable sofa. Using multiple cushions, the participants iteratively explored comfortable sitting as well as lying postures in diverse body orientations. The result showed a variety of postures and support configurations for the comfort of working in a non-desk setting. Unlike working a ta conventional desk setting, the body parts supported each other as well as a tablet, and preferred postures were unique to each activity. By systematically analyzing and categorizing postures, we uncovered new design opportunities for furniture and interactive systems that do not deal with a traditional desk setting.

2020 [2]

Foam Sheets as Material for Fabricating Large and Functional Soft Objects

Doheon Kim, Joon-Gi Shin, Daniel Saakes

DIS '20 Companion: Companion Publication of the 2020 ACM Designing Interactive Systems Conference


We report on our experiments to fabricate soft, functional and furniture size objects from PE foam sheets. This material is desirable because it is flexible, lightweight, widely available in a variety of thicknesses, and could be made out of sugar cane. We present a set of unique joining mechanisms that exploit the flexibility and do not use adhesive or fasteners. We show how to program softness in meta structures to avoid the use of multiple materials. Finally, we demonstrate a number of examples and discuss the applicability for prototyping as well as customization in deploying the design.

Body Follows Eye: Unobtrusive Posture Manipulation Through a Dynamic Content Position in Virtual Reality

Joon-Gi Shin, Doheon Kim, Chaehan So, Daniel Saakes

CHI '20: Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems

[DOI] [CHI 2020 Remote Presentation] [CHI 2020 video preview]

While virtual objects are likely to be a part of future interfaces, we lack knowledge of how the dynamic position of virtual objects influences users’ posture. In this study, we investigated users’ posture change following the unobtrusive and swift motions of a content window in virtual reality (VR). In two perception studies, we estimated the perception threshold on undetectable slow motions and displacement during an eye blink. In a formative study, we compared users’ performance, posture change as well as subjective responses on unobtrusive, swift, and no motions. Based on the result, we designed concept applications and explored potential design space of moving virtual content for unobtrusive posture change. With our study, we discuss the interfaces that control users and the initial design guidelines of unobtrusive posture manipulation.

2019 [2]

Towards large scale high fidelity collaborative augmented reality

Damien Constantine Rompapas, Christian Sandor, Alexander Plopski, Daniel Saakes, Joon-Gi Shin, Takafumi Taketomi, Hirokazu Kato

Computer & Graphics 2019


In recent years, there has been an increasing amount of Collaborative Augmented Reality (CAR) experiences, classifiable by the deployed scale and the fidelity of the experience. In this paper, we create HoloRoyale, the first large scale high fidelity (LSHF) CAR experience. We do this by first exploring the LSHF CAR design space, drawing on technical implementations and design aspects from AR and video games. We then create and implement a software architecture that improves the accuracy of synchronized poses between multiple users. Finally, we apply our target experience and technical implementation to the explored design space. A core design component of HoloRoyale is the use of visual repellers as crowd control elements to guide players away from undesired areas. To evaluate the effectiveness of the employed visual repellers in a LSHF CAR context we conducted a user study, deploying HoloRoyale in a 12.500 m2 area. The results from the user study suggest that visual repellers are effective crowd control elements that do not significantly impact the user’s overall immersion. Overall our main contribution is the exploration of a design space, discussing several means to address the challenges of LSHF CAR, the creation of a system capable of LSHF CAR interactions along with an experience that has been fitted to the design space, and an indepth study that verifies a key design aspect for LSHF CAR. As such, our work is the first to explore the domain of LSHF CAR and provides insight into designing experiences in other AR domains.

Slow Robots for Unobtrusive Posture Correction

Joon-Gi Shin, Eiji Onchi, Maria Jose Reyes, Junbong Song, Uichin Lee, Seung-Hee Lee, Daniel Saakes

CHI '19: Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems


Prolonged static and unbalanced sitting postures during computer usage contribute to musculoskeletal discomfort. In this paper, we investigated the use of a very slow moving monitor for unobtrusive posture correction. In a first study, we identified display velocities below the perception threshold and observed how users (without being aware) responded by gradually following the monitor's motion. From the result, we designed a robotic monitor that moves imperceptible to counterbalance unbalanced sitting postures and induces posture correction. In an evaluation study (n=12), we had participants work for four hours without and with our prototype (8 in total). Results showed that actuation increased the frequency of non-disruptive swift posture corrections and significantly reduced the duration of unbalanced sitting. Most users appreciated the monitor correcting their posture and reported less physical fatigue. With slow robots, we make the first step toward using actuated objects for unobtrusive behavioral changes.

2018 [5]

Interactive and Situated Guidelines to Help Users Design a Personal Desk that Fits Their Bodies

Bokyung Lee, Joon-Gi Shin, Hyoshin Bae, Daniel Saakes

DIS '18: Proceedings of the 2018 Designing Interactive Systems Conference


In this paper, we explored the application of human factor guidelines in personal fabrication. This is useful for several Do-It-Yourself (DIY) scenarios, including users adjusting workstation configurations or designing a desk to fit a single person. We identified a dependency map between the user's anthropometrics, ergonomic pose recommendations, and design dimensions. Based on this, we developed situated and interactive guidelines to assist users in design applications. We applied these guidelines in a Virtual Reality (VR) system that lets users customize their desk and provides real-time feedback and feedforward on pose and design. We evaluated the system with six participants, had each one design a personal desk, fabricated their desks, and let them work on their desks for four hours. The design and evaluation contribute to fabrication tools as it helped users be aware of their pose and ergonomic knowledge, and design for their bodies and needs.

Rolling Graphics: Create Graphics on the Cross Section of a Roll Cake

Joon-Gi Shin, Maria Jose Reyes, Su Ah Han, Moojin Joh, Daniel Saakes

CHI EA '18: Extended Abstracts of the 2018 CHI Conference on Human Factors in Computing Systems


Food fabrication offers a new dimension to home cooking. We see the design challenge not in automating cooking tasks, but in augmenting the tangible experience, skill building and enjoyment of baking. As an example of such augmentation, we present a novel concept for designing and fabricating roll cakes with custom cross-section graphics.

Roll cakes are made by rolling a flat piece of cake into a spiral. In our application, users draw the cross section image of their cake and we calculate a printable template as a guide to color the unrolled cake. Users mix colored batter and use a custom 3D printed nozzle to arrange the batter on the template.

After baking the batter in the oven, users simply roll it into a roll cake and magically their design is shown on the cross-section.

We identified and solved the key difficulties in making graphics such as a consistent layer thickness and aligning the graphics in the spiral. With Rolling Graphics, we expand the potential of food printing with custom graphics and potentially, custom tastes.

Actuating a Monitor for Posture Changes

Joon-Gi Shin, Woohyeok Choi, Uichin Lee, Daniel Saakes

CHI EA '18: Extended Abstracts of the 2018 CHI Conference on Human Factors in Computing Systems


The position and orientation of a monitor affects users' behavior at their desk. In this study, we explored and designed six types of interactions between an actuated monitor and users to induce posture changes. We built a virtual monitor that simulates the motions of an actuated monitor and slowly moved in the opposite direction of unbalanced sitting postures. We conducted an explorative study with eight participants. The study showed participants' responses and step by step posture changes toward balanced sitting postures. As contribution, we share considerations for designing monitor actuation that induce posture intervention.

Situated Game Level Editing in Augmented Reality

Gary Ng, Joon-Gi Shin, Daniel Saakes

TEI '18: Proceedings of the Twelfth International Conference on Tangible, Embedded, and Embodied Interaction


Level editors let end-users create custom levels and content within a given video game. In this paper, we explore the concept and design of Augmented reality game level editors. These new types of editors are not only spatial and embodied, but also situated, as they enable users to tailor games to the unique characteristics and emotional value of their own space.

We present the design and implementation of a prototype level editor that runs on the Microsoft HoloLens. The editor enables users to add virtual content in their homes and add interactions through spatial trigger-action game-logic programming. We had pairs of students create games with the prototype and play each other's games. They reported that games are fun to make, play, and watch others play. Based on the design and evaluation, we propose guidelines for Augmented reality game-authoring tools for end users.

Couples Designing their Living Room Together: a Study with Collaborative Handheld Augmented Reality

Joon-Gi Shin, Gary Ng, Daniel Saakes

AH '18: Proceedings of the 9th Augmented Human International Conference


In this paper, we investigate the use of Augmented Reality for users designing together. We present a design application that runs on multiple synchronized and spatially aware tablets to support couples making interior decisions in and for their future living room. Based on the prior art into collaborative design, we suggest a novel design interface that deals with situated design and supports virtual workspaces. We asked six couples to design together with our prototype and analyzed their design process, the roles they took, and how they communicated. The results suggest that the social practice of couples designing in and for their home differs from professional design teams and involves more than just positioning furniture in space. We use the design, the prototype and the study to discuss implications for spatial in-situ tools concerning intimacy, collaboration, and design process. The findings are useful for future applications that deal with collaborative applications for casual users.

2016 [2]