My role: project lead, system design/control/anaylsis, user experiment
Collaborator: Donghyeon Lee, Junyong Bang, Hyung Gon Shin
Advisor: Wan Kyun Chung, Seungmoon Choi, Keehoon Kim

Jinhyuk Yoon, Donghyeon Lee, Junyong Bang, Hyung Gon Shin, Wan Kyun Chung, Seungmoon Choi, and Keehoon Kim. Cable-Driven Haptic Interface with Movable Bases Achieving Maximum Workspace and Isotropic Force Exertion. IEEE Transactions on Haptics, vol. 16, no. 3, pp. 365-378, 2023.

Haptic interactions play an essential role in education to enhance learning efficiency; however, haptic information for virtual educational content remains lacking. This work proposes a planar cable-driven haptic interface with movable bases that can display isotropic force feedback with maximum workspace extension on a commercial screen display. A generalized kinematic and static analysis of the cable-driven mechanism is derived by considering movable pulleys. Based on the analyses, a system including movable bases is designed and controlled to maximize the workspace subject to isotropic force exertion for the target screen area. The proposed system is evaluated experimentally as a haptic interface represented by the workspace, isotropic force-feedback range, bandwidth, Z-width, and user experiment. The results indicate that the proposed system can maximize workspace to the target rectangular area and exert isotropic force up to 94.0% of the theoretical computed one within the workspace.

My role: hardware prototyping, sensing system design
Collaborator: Chaeyong park, Seungjae Oh
Advisor: Seungmoon Choi

Chaeyong Park, Jinhyuk Yoon, Seungjae Oh, and Seungmoon Choi. Augmenting Physical Buttons with Vibrotactile Feedback for Programmable Feels. In Proceedings of the ACM Symposium on User Interface Software and Technology (UIST), pp. 924-937, October 20-23, 2020 (Acceptance rate 21.6%).

Physical buttons provide clear haptic feedback when pressed and released, but their responses are unvarying. Physical buttons can be powered by force actuators to produce unlimited click sensations, but the cost is substantial. An alternative can be augmenting physical buttons with simple and inexpensive vibration actuators. When pushed, an augmented button generates a vibration overlayed on the button’s original kinesthetic response, under the general framework of haptic augmented reality. We explore the design space of augmented buttons while changing vibration frequency, amplitude, duration, and envelope. We then visualize the perceptual structure of augmented buttons by estimating a perceptual space for 7 physical buttons and 40 augmented buttons. Their sensations are also assessed against adjectives, and results are mapped into the perceptual space to identify meaningful perceptual dimensions. Our results contribute to understanding the benefts and limitations of programmable vibration-augmented physical buttons with emphasis on their feels.

My role: dynamic analysis, application development
Advisor: Geonhee Lee, Wangi Park, Junwon Seo, Yongsoo Kyong

Dynamic analysis of hinge takes important part on developing digital oven. Traditional method that uses a computational simulation software, however, takes complicated manipulation process. Hence, it cannot provide reverse engineering, which modifies dynaimc property such as torque and results in a desired hinge profile. Interactive Torque Designer solves these problems through dynamic analysis and web application which even enables interactive design with graphical modification.
Web application has universality and scalability. Any user can use this application only with internet browser and adapting additional function requires just simple programming. Using d3.js library, plotted data enables to reflect dynamic analysis result graphically. Consequently, user can get torque profile data only with manipulating visualized cam profile data and vice versa. Direct user experience feedbacks of field engineers according to iterative design process suggests multiple drag and other functions which make design process more easily. With the final version of Interactive Torque Designer, user can intuitively analyze torque and do the inverse engineering, which significantly simplifies mechanical design process of digital oven. Furthermore, it helps engineer to explain to other division members about mechanical phenomena through graphical expression.

My role: speaker, actor, content development

Based on the foundational business of Korea Foundation for the Advancement of Science & Creativity (KOFAC), science communication focuses on presenting science to the public with ease. I participated developing and performing contents such as talk, street performance, and play.
I mainly focused on delivering publich speech about mechanical engineering, such as robotics, bioengineering, control, machine learning, and science communication as visiting middle school, high school, library and science institution. Audience varies from elementary and middle school student to office worker, teacher, and public.
Speech material contains infographic, video, story and audience participation through game and science experiment for interaction. Audience survey shows that talk contains many unfamiliar and complex scientific knowledge but can be easily understood. List of the talk is shown below.

2020
12.05  Pohang Youngshin High School
11.14  Gyeongju Moonhwa High School
10.31  Andong Kyung-An High School
10.28  Pohang High School
09.25  Pohang Idong High School

2018
01.12  Daegu Suseong-gu Gosan Library

2017
12.28  KIST Science Station
12.27  Osan Sema High School
12.21  Andong Kyung An Middle School
12.20  Jeonbuk Imsil High School
12.15  Cheongju Geumcheon High School
12.14  Daegu Sungseo Middle School
11.26  Gwangju Ildong Middle School
11.24  Ilsan Deogi High School
11.17  Busan Youngnam Middle School
11.10  Ulsan Dongchun High School
11.03  Andong Middle School
11.02  Uljin Maehwa Middle School
10.31  Mokpo Jeongmyeong Girls' Middle School
10.30  Mokpo Hyein Girls High School
10.25  Incheon Hak Ik High School
10.23  Pyeongtaek High School
10.18  Gwangju Chosun University High School
10.17  Incheon Buil Girl's Middle School
10.16  Daejeon Hanbat Middle School
10.13  Wonju High School
08.31  KIST Science Station
06.12  Yongin Seongji Highschool
05.19  Busan Samsung Girl's High School
05.10  Yangsan Mulgeum High School

2016
12.02  Yeungchon High School
11.23  The 5th Integrated Science Leading Teacher Training
10.14  Pohang High School
09.06  Sunil Girls High School
09.03  National Youth Science Exploration Competition
07.22  The 13th Yeongcheon Bohyeonsan Starlight Festival

My role: contents development, performance directing
Collaborator: Yukung Jung

Art work at 2017 Artience Creation Challenge 30x30, 30 hours straight collaboration work with one artist. British Council Korea hosted and Daejeon Culture and Arts Foundation supported the challenge. To express challenge topic ageing, we chose entropy which measures disorder and indicates direction of time.
Video art work shows increase of entropy with getting aged person. Performer fills paint named life on white drawing paper named time, as being covered up with rope named disorder. Just as life, performer shows her agony as holding and dropping brush or trying to break the rope. However, inside of irrefutable and natural flow of entropy, she finally accepts disorder which fully covered up her body at ease.

Since competition started with zero-based, team had to find an idea to metaphor ageing through a compact communication. Conversation lasted about 6 hours as sharing knowledge, experience and technique of each other. Partner had majored ballet around 10 years. Using this strength facilitated expression of ageing through tangled rope and randomly painted drawing paper, which also resembled notion of entropy. Limitation in time and resources of the competition restricted shooting subject to non-professional, field, or daily products. Connecting two different backgrounds and overcoming difficulty of 30 hours straight work produced successful visual metaphor for concept of entropy and ageing through video art. This work described entrophy and ageing in intuitive manner to the judge and participant and won the Runners-Up of the competition.

My role: class planning, teaching
Collaborator: Aram Jang, Soyoung Kim, Younji Shin, Hyun Jo, and Ilhwan Hwang

Collaboration voluntary project with Korea National University of Arts students. Project aims enhancing elementary student's interest and understanding in science with picture book, drawing practice and making a toy.
During one month before the class, every member prepared his/her own class contents individually. As taking part of class planning, experience of science communication suggested making a toy which includes actual movement with motors and created explanation of basic concept of electromagnetism. After preparation, all members gathered and rehearsed class including drawing and hands-on activity. Team visited Charmsarang Regional Children's Center and Haemaji Regional Children's Center, where are located in Pohang. Each class took around 4 hours and team met about 40 children in total. Through class and activities, class delivered basic concept of electromagnetism such as current, voltage, resistance and electron to the children. Children filled the picture book and made a toy with diverse styles and movements. After the end of the class, children effectively linked their knowledge learned from the class to describe the movement of the toy.

My role: team building, sponsor and speaker contact, facilitating
Collaborator: Seewoo Lee, Jiwoo Kang, Beomsoo Lim, Jonggeon Lee, Sieun Park, Jaewon Yoo and Eunji Kwon

Pohang University of Science and Technology (POSTECH) has a difficulty in experiencing a variety of idea and people as located on Pohang. To overcome this difficulty, my team had gathered as the second organizer after 4 years of the first event. Directing includes giving each role and responsibility to organizers, contacting sponsor and speaker, and facilitating the event. Regular application was sold out in 50 seconds after open sign-ups and team invited professor, writer, and pop-singer as speaker.

Under theme 'question', event held in October 31, 2015 at POSCO International Conference Hall. POSTECH, Penta security system, A Twosome Place, Domino Pizza, Cafe Rio, PBS, Poapper, Ramen Beravo and Agit supported event as sponsors.

Human & Technology; Practicing Healthy Hybridity - Jintaek Kim
JinTaek Kim is a professor at POSTECH Department of Creative IT Engineering. He always reasons with body and sense and studies image, media arts and transhuman.
Disconnected Society, Connected People - Seoyoon Choi
SeoYoon Choi is editor of "Monthly Ingyeo" and participated as a writing staff in Hankyoreh 21, Sisa in Live, Hankook Newspaper, and Media Today.
How to Make Vision? - SeongJin Park
Seongjin Park is a professor at POSTECH department of Mechanical Engineering. He studies about micro manufacturing and multiscale simulation.
Why Human Seek for Unreachable Universe? - Jaechan Hwang
Jaechan Hwang is a professor at Kyeongpook National Universitiy department of Astronomy and Atmospheric Sciences. He has interest in cosmology, space biology and future of humanity
Can Science Conquer The Cancer? - Seungwoo Lee
SeungWoo Lee is a professor at POSTECH department of Integrative Biosciences and Biotechnology. He studies cancer treatment with human immune system.
Finding The Story Without Knowing The Words - Lena Park
Lena Park is a popular singer in Korea. She debuted at 1998 with her first album, 'piece', and released 8 albums after. She performs on various stages with her unique perspective and technique.