Dongho Kwak

• Sandanger, Tonje Viddal; Sivachandran, Annica; Eriksen, Roman Stenseth; Baselizadeh, Adel; Otterdijk, Maria van & Kwak, Dongho [Show all 7 contributors for this article] (2024). Users¡¯ perception and dynamic motion velocity matching in human-robot approach scenarios. In Harada, Kensuke; Demircan, Emel & Weiss, Astrid (Ed.), Proceedings of 2024 IEEE International Conference on Advanced Robotics and Its Social Impacts (ARSO 2024). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798350344646. p. 67¨C73. doi: 10.1109/ARSO60199.2024.10557976. Full text in Research Archive
• Kwak, Dongho; Baselizadeh, Adel; Otterdijk, Marieke van; Saplacan, Diana & T?rresen, Jim (2024). "Noisy" Matching of Motion Velocity of an Assistive Robot to the Users' Walking Velocity. ACM/IEEE International Conference on Human-Robot Interaction (HRI). ISSN 2167-2121. doi: 10.1145/3610978.3640546. Full text in Research Archive Show summary

  This study investigates the impact of dynamic matching of robot motion velocity to users' walking velocity in a human-robot approach scenario on three categories: perceived comfort, interactivity, and naturalness. Considering age diversity, participants were divided into two age groups. Young participants tended to rate higher for all three categories when the robot's approaching velocity was dynamically matched. In contrast, elderly participants preferred a steady and slow robot approach for comfort and predictability. These findings contribute to the ongoing effort to design assistive robots that effectively cater to diverse user groups, ultimately enhancing user satisfaction and acceptance. Taken together, this study highlights the importance of dynamically tailoring robot behaviors based on user demographics for positive Human-Robot Interactions.

• Kwak, Dongho; Combriat, Thomas Michel Daniel; Jensenius, Alexander Refsum & Olsen, Petter Angell (2023). Characterization of Mechanical and Cellular Effects of Rhythmic Vertical Vibrations on Adherent Cell Cultures. Bioengineering. 10(7), p. 1¨C19. doi: 10.3390/bioengineering10070811. Full text in Research Archive Show summary

  This paper presents an innovative experimental setup that employs the principles of audio technology to subject adherent cells to rhythmic vertical vibrations. We employ a novel approach that combines three-axis acceleration measurements and particle tracking velocimetry to evaluate the setup¡¯s performance. This allows us to estimate crucial parameters such as root mean square acceleration, fluid flow patterns, and shear stress generated within the cell culture wells when subjected to various vibration types. The experimental conditions consisted of four vibrational modes: No Vibration, Continuous Vibration, Regular Pulse, and Variable Pulse. To evaluate the effects on cells, we utilized fluorescence microscopy and a customized feature extraction algorithm to analyze the F-actin filament structures. Our findings indicate a consistent trend across all vibrated cell cultures, revealing a reduction in size and altered orientation (2D angle) of the filaments. Furthermore, we observed cell accumulations in the G1 cell cycle phase in cells treated with Continuous Vibration and Regular Pulse. Our results demonstrate a negative correlation between the magnitude of mechanical stimuli and the size of F-actin filaments, as well as a positive correlation with the accumulations of cells in the G1 phase of the cell cycle. By unraveling these analyses, this study paves the way for future investigations and provides a compelling framework for comprehending the intricate cellular responses to rhythmic mechanical stimulation.

• Kwak, Dongho; Combriat, Thomas Michel Daniel; Wang, Chencheng; Scholz, Hanne; Danielsen, Anne & Jensenius, Alexander Refsum (2022). Music for Cells? A Systematic Review of Studies Investigating the Effects of Audible Sound Played Through Speaker-Based Systems on Cell Cultures. Music & Science. 5. doi: 10.1177/20592043221080965. Full text in Research Archive Show summary

  There have been several studies investigating whether musical sound can be used as cell stimuli in recent years. We systematically searched publications to get an overview of studies that have used audible sound played through speaker-based systems to induce mechanical perturbation in cell cultures. A total of 12 studies were identified. We focused on the experimental setups, the sounds that were used as stimuli, and relevant biological outcomes. The studies are categorized into simple and complex sounds depending on the type of sound employed. Some of the promising effects reported were enhanced cell migration, proliferation, colony formation, and differentiation ability. However, there are significant differences in methodologies and cell type-specific outcomes, which made it difficult to find a systematic pattern in the results. We suggest that future experiments should consider using: (1) a more controlled acoustic environment, (2) standardized sound and noise measurement methods, and (3) a more comprehensive range of controlled sound parameters as cellular stimuli.

• Kwak, Dongho; Olsen, Petter Angell; Danielsen, Anne & Jensenius, Alexander Refsum (2022). A trio of biological rhythms and their relevance in rhythmic mechanical stimulation of cell cultures. Frontiers in Psychology. 13. doi: 10.3389/fpsyg.2022.867191. Full text in Research Archive Show summary

  The primary aim of this article is to provide a biological rhythm model based on previous theoretical and experimental findings to promote more comprehensive studies of rhythmic mechanical stimulation of cell cultures, which relates to tissue engineering and regenerative medicine fields. Through an interdisciplinary approach where different standpoints from biology and musicology are combined, we explore some of the core rhythmic features of biological and cellular rhythmic processes and present them as a trio model that aims to afford a basic but fundamental understanding of the connections between various biological rhythms. It is vital to highlight such links since rhythmic mechanical stimulation and its effect on cell cultures are vastly underexplored even though the cellular response to mechanical stimuli (mechanotransduction) has been studied widely and relevant experimental evidence suggests mechanotransduction processes are rhythmic.

• Kwak, Dongho; Krzyzaniak, Michael Joseph; Danielsen, Anne & Jensenius, Alexander Refsum (2022). A mini acoustic chamber for small-scale sound experiments. In Iber, Michael & Enge, Kajetan (Ed.), Audio Mostly 2022: What you hear is what you see? Perspectives on modalities in sound and music interaction. ACM Publications. ISSN 9781450397018. p. 143¨C146. doi: 10.1145/3561212.3561223. Full text in Research Archive Show summary

  This paper describes the design and construction of a mini acoustic chamber using low-cost materials. The primary purpose is to provide an acoustically treated environment for small-scale sound measurements and experiments using ¡Ü 10-inch speakers. Testing with different types of speakers showed frequency responses of <?10?dB peak-to-peak (except the ¡±boxiness¡± range below 900?Hz), and the acoustic insulation (soundproofing) of the chamber is highly efficient (approximately 20?dB?SPL in reduction). Therefore, it provides a significant advantage in conducting experiments requiring a small room with consistent frequency response and preventing unwanted noise and hearing damage. Additionally, using a cost-effective and compact acoustic chamber gives flexibility when characterizing a small-scale setup and sound stimuli used in experiments.

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• Kwak, Dongho; Baselizadeh, Adel; Otterdijk, Marieke van; Saplacan, Diana & Torresen, Jim (2024). "Noisy" Matching of Motion Velocity of an Assistive Robot to the Users' Walking Velocity. Full text in Research Archive
• Bishop, Laura & Kwak, Dongho (2024). Ignoring a noisy metronome during dyadic drumming. Full text in Research Archive
• Karlsen, Einar; T?rresen, Jim; Ellefsen, Kai Olav; Badescu, Claudia Andreea; Otterdijk, Marieke van & Watanabe, Shin [Show all 9 contributors for this article] (2023). M?te den nye helsearbeideren. [Journal]. Elektronikk. Full text in Research Archive
• T?rresen, Jim & Kwak, Dongho (2022). Tutorial: Rhythm in Development and Learning ¨C Similarities and Differences Between Humans and Technology. Full text in Research Archive
• Kwak, Dongho; Krzyzaniak, Michael Joseph; Danielsen, Anne & Jensenius, Alexander Refsum (2022). A mini acoustic chamber for small-scale sound experiments. Full text in Research Archive Show summary

  This paper describes the design and construction of a mini acoustic chamber using low-cost materials. The primary purpose is to provide an acoustically treated environment for small-scale sound measurements and experiments using ¡Ü 10-inch speakers. Testing with different types of speakers showed frequency responses of <?10?dB peak-to-peak (except the ¡±boxiness¡± range below 900?Hz), and the acoustic insulation (soundproofing) of the chamber is highly efficient (approximately 20?dB?SPL in reduction). Therefore, it provides a significant advantage in conducting experiments requiring a small room with consistent frequency response and preventing unwanted noise and hearing damage. Additionally, using a cost-effective and compact acoustic chamber gives flexibility when characterizing a small-scale setup and sound stimuli used in experiments.

• Kwak, Dongho Daniel (2021). Presentation at Oslo Life Science Conference event. Full text in Research Archive Show summary

  From the "Music for stem cells: Aiming to cure diabetes with sound waves" Oslo Life Science Conference event.

• Lan, Qichao & Kwak, Dongho Daniel (2021). Musical performance on GLICOL at Oslo Life Science Conference. Full text in Research Archive Show summary

  From the "Music for stem cells: Aiming to cure diabetes with sound waves" Oslo Life Science Conference event.

• Kwak, Dongho (2021). The human body as a rhythm machine. Full text in Research Archive Show summary

  "Rhythms are a basic phenomenon in all physiological systems¡±. Can we think of the human body as a rhythm machine? How does the body generate rhythms and process external rhythms? I have been involved in a research project where we are studying cellular responses to acoustic perturbation. It was noticeable that, in such mechanobiology research, the type of parameters used as sound stimuli are typically limited to frequency and amplitude. It seems necessary to expand the possibilities of controllable parameters to explore wider cellular properties that might have been overlooked. For this reason, musically and physiologically relevant features have been considered such as rhythm. Physiological rhythms are of particular interest which can be categorised into different time scales (ultradian, circadian, and infradian rhythms). They are typically found in vital parts of the body such as the cardiorespiratory system, or in patterns that are vital for the body such as sleep and wake cycles. Through a theoretical investigation of different levels of physiological rhythmicity, there are some indications of common essential elements (central, exterior, and reflex rhythms) that need to exist simultaneously to maintain homeostasis. In this Food & Paper session, I would like to share and have an open discussion on these essential rhythmic features of the body and some of the examples we can find on different rhythmic levels (cells, organs, and the whole body).

• Kwak, Dongho; Danielsen, Anne & Jensenius, Alexander Refsum (2021). Music for cells: The human body as a rhythm machine. Full text in Research Archive
• Kwak, Dongho Daniel (2020). Food & Paper: Music for cells?! Full text in Research Archive Show summary

  Music for cells. Is there such a thing? Why do we want to use sound to manipulate, regulate or change certain conditions in our body, and something even as small as human cells? The use of sound and music to provide beneficial effect on biological being or on human is not a novel idea. Ancient Greek and Romans have already recognized this fascinating relationship. In our modern days, there have been uprising interests in mechanobiology among the cell biologists. A favourable use of sound is evident in numerous experiments reporting the responses of biological cells to audio and music stimuli. The prospective medical benefits of investigating correlations between sound and cellular responses are promising for the life sciences. However, although a considerable amount of literature is available, many of them are case- and cell-specific and there is still a lack of comprehensive understanding of the relationship between employed sound stimuli and different responses of biological cells under examination.

• Kwak, Dongho Daniel (2020). HTH Enrichment Seminar: Introduction to data sonification. Full text in Research Archive
• Kwak, Dongho Daniel (2020). HTH Enrichment Seminar: Effect of mechanical vibration stress in cell culture on human induced pluripotent stem cells. Full text in Research Archive
• Kwak, Dongho; Jensenius, Alexander Refsum; Danielsen, Anne; Scholz, Hanne & Olsen, Petter Angell (2023). Music for cells? Rhythmic mechanical stimulations of cell cultures. Universitetet i Oslo. Full text in Research Archive Show summary

  This dissertation investigates how acoustic parameters and musical elements can be generated and manipulated to induce beneficial mechanical stimulations and alterations in cell cultures. The research has been conducted as part of a life science convergence environment, and the theoretical framework and experimental method in this dissertation are derived from three different disciplines: biology, music technology, and physics. The theoretical discussions centre around biological cell sensing mechanisms, the physical limitations and potentiality of audible sound to be used as mechano-acoustic cellular stimuli, and the concept of rhythm from biology and music technology perspectives. The methods include audio signal processing, physical characterisation of the experimental setup, various biological assays, and microscopic image feature extraction. Such a radically interdisciplinary approach culminated in laboratory experiments involving sound vibrations of human cell cultures using a vertical vibration system controlled by synthesized audio signals. The experimental variables included: No Vibration (NV, control), Continuous Vibration (CV), Regular Pulse (RP), and Variable Pulse (VP). The CV condition was categorised as non-rhythmic in this dissertation, while RP and VP were categorised as rhythmic conditions. The results demonstrate alterations in F-actin filament structure (length, thickness, angle) and the tendency of increased levels of cells in the G1-phase cell cycle in vibrated cell cultures. The ¡°effect¡± was more apparent under the non-rhythmic (CV) condition than rhythmic conditions (RP and VP). The results also show that F-actin filament structural properties are negatively correlated (r < -.9), and the number of cells in the G1-phase cycle is positively correlated (r > .9) in relation to the magnitudes of mechanical parameters (RMS acceleration and shear stress). Nevertheless, the biological mechanism(s) responsible for the observed effects has yet to be characterised. The results from this dissertation inspire further studies on the effects of rhythmic mechanoacoustic stimulation on cellular biological rhythms (e.g., regulation of CLOCK, PER, and CRY genes).

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