Sungkyunkwan University (Prof. Taesung kim) develops “Free-standing ferro-ionic memristor”
which can only operate with tip-induced shear strain
Mechanical Engineering KIM, TAESUNG Prof. · first author: Jin-Hyoung Lee, Gun-Hoo Woo
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Sungkyunkwan University (Prof. Taesung kim) develops “Free-standing ferro-ionic memristor”
Sungkyunkwan University announced that Professor Tae-sung Kim’s research group at the school of mechanical engineering (first author: Jin-Hyoung Lee, Gun-Hoo Woo) has developed a "Free-standing ferro-ionic memristor" that selectively controls ion migration using only a tip-induced shear strain. Memristor devices, which are attracting attention as the next generation of devices that can be used in next-generation non-Von Neumann structures, have various strengths compared to conventional semiconductor devices such as in-memory computing and weight storage at low power, but it is essential to secure the reliability of each memristor device to realize practical large-scale neural computing. However, the biggest limitation of memristor devices is the "randomness" of ion movement, and this stochastic ion behavior has traditionally prevented them from being commercially valuable due to the critical limitation that it reversibly affects the reliability and reproducibility of memristor devices. To address this stochastic limitation, this research team has focused at the flexoelectric effect, which occurs at the nanometer (nm) scale. In 2011, it was reported in the previous research that the flexoelectric field can be maximized when the lattice structure of a material is bended by an external force, generating the internal polarization and electric fields. However, in order to selectively activate phase change and ion migration at the desired location within flexoelectricity, much larger lattice bending is required than those in previous studies. Therefore, to spatially maximize the flexoelectric field beyond previous studies, they applied vertical shear stresses to free-standing 2D materials with an atomic force microscope (AFM) tip to selectively maximize the flexoelectric field and its corresponding downward polarization at the specific regions. Consequently, the research team successfully observed the selective growth of conductive filaments via localized flexoelectric field. Furthermore, they succeeded to reversibly control the phase transition threshold voltage by modulating the bottom ferroelectric polarization, enabling active spatial control of conductive filaments at the nanometer scale. Professor Tae-Sung Kim remarked, “This research overcomes the stochastic limitations of conventional ferro-ionic materials and offers a new perspective on ion movement based on the flexoelectric effect from a structural standpoint. It is expected to significantly enhance the performance and reliability of semiconductor devices in future studies by enabling precise spatial control of ions.” This research was supported by the National Research Foundation of Korea and the Korea Basic Science Institute. The research were published in the prestigious international journal “Nature Communications” on June 18. ※Title: Free-standing two-dimensional ferro-ionic memristor ※Author: Taesung Kim (corresponding author), Jinhyoung Lee, Gunhoo Woo (first author), Jinill Cho, Sihoon Son, Hyelim Shin, Hyunho Seok, Min-Jae Kim, Eungchul Kim, Ziyang Wang, Boseok Kang, Won-Jun Jang (co-author) ※Journal Link: https://www.nature.com/articles/s41467-024-48810-3 Next-generation freestanding memristor device platform implemented based on probe-guided substation
- No. 254
- 2024-07-02
- 372
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Protein tyrosine kinase 2 (PTK2) as a potential biomarker and therapeutic target in lung cancer
Lung cancer is one of the leading causes of cancer-related mortality worldwide, induced by genetic mutations and various external factors. Non-small cell lung cancer (NSCLC), which comprises the majority of lung cancer cases, is significantly driven by diverse genetic mutations. Consequently, genetic data from lung cancer patients are actively used to identify the causes and factors of lung cancer development and progression, as well as to propose treatment methods. Protein tyrosine kinase 2 (PTK2) is a non-receptor tyrosine kinase that plays a crucial role in cell migration, survival, proliferation, and interactions with the extracellular matrix. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that regulates cancer cell growth, differentiation, and survival, making it an important therapeutic target in NSCLC. EGFR mutations promote cell proliferation, and EGFR tyrosine kinase inhibitors (TKIs) are used as NSCLC treatments. However, resistance to EGFR TKIs can develop during cancer treatment. Toll-like receptors (TLRs) are essential components of the innate immune system, recognizing pathogen-associated molecular patterns (PAMPs) and promoting immune responses. In the tumor microenvironment, TLRs regulate interactions between immune cells and cancer cells, with some studies suggesting that TLRs can promote cancer cell survival and growth. Despite these findings, research on the regulatory interactions between PTK2, EGFR, and TLRs is limited, and the clinical implications of their expression and interactions on lung cancer patient survival remain unclear. Our research team utilized genetic data from lung cancer patient-derived tumor and normal tissues to confirm that PTK2 expression significantly impacts lung cancer cell proliferation and tumor formation. Additionally, through gene expression and clinical data analysis, we identified that PTK2 expression in lung cancer cells is associated with the expression of EGFR and TLRs, which correlates with patient survival. To provide scientific evidence for this association, we employed CRISPR-Cas9 gene editing, in vitro cancer progression assays, 3D tumor spheroid assays, and in vivo xenografted NSG mouse assays (Figure 1). The results confirmed that PTK2 regulates lung cancer development and formation mediated by EGFR and TLRs. Furthermore, we validated the efficacy of PTK2 inhibitors in modulating lung cancer development and formation mediated by these pathways. Our findings present a significant milestone for biomarker development targeting EGFR and TLR signaling in future lung cancer treatment strategies, potentially contributing to the establishment of new anticancer treatment strategies in the field of personalized precision medicine. This research was contributed by Ji-Young Kim (Integrated MS/PhD Program, School of Medicine, Sungkyunkwan University), Ji-Hye Shin (Integrated MS/PhD Program, School of Medicine, Sungkyunkwan University), and Dr. Mi-Jung Kim (School of Medicine, Sungkyunkwan University). The results were published in the renowned international journal "Biomarker Research" (IF: 11.1, JCR CATEGORY in MEDICINE top 7%) in the field of personalized medicine and biomarkers. This research was supported by the Mid-career Researcher Support Program and the Basic Research Laboratory Program. Article: Kim JY, Shin JH, Kim MJ, Choi B, Kang Y, Choi J, Kim SH, Kwan D, Kim DH, Chun E, Lee KY. PTK2 is a potential biomarker and therapeutic target for EGFR- or TLRs-induced lung cancer progression via the regulation of the cross-talk between EGFR- and TLRs-mediated signals. Biomark Res. 2024 May 31;12(1):52 논문명: PTK2 is a potential biomarker and therapeutic target for EGFR- or TLRs-induced lung cancer progression via the regulation of the cross-talk between EGFR- and TLRs-mediated signal. (Biomark Res. 2024 May 31;12(1):52) Figure 1. PTK2 is a potential biomarker and therapeutic target for EGFR- or TLRs-induced lung cancer progression
- No. 253
- 2024-06-21
- 507
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Why do we feel warmer in humid weather? Uncovering how sweat droplets regulate body temperature
Professor Byung Mook Weon of the School of Advanced Materials Science and Engineering led pioneer research that for the first time identified the incomplete evaporation of sweat droplets as the physical source of the 'Heat Index' that determines body temperature. As global warming has led to more hot and humid days, the deaths associated with heat waves have been rising in Europe and the United States. The body's feel temperature, which varies with air temperature and humidity, is determined by the ‘Heat Index’, used in weather forecasting all around the world. It is known that people experience higher temperatures on humid days compared to dry days. For example, a day with 32°C and 70% humidity has a ‘Heat Index’ of 41°C, meaning that the feeling temperature in the human body is much higher than the actual air temperature. Therefore, very moist and hot days can be life-threatening because of the high ‘Heat Index’ values, leading to difficulty in maintaining body temperature. However, little is known about the exact physical roots of the ‘Heat Index’. All we know is that hot and humid days are hard to endure. Our bodies maintain body temperature by releasing sweat and transferring heat as these sweat droplets evaporate, a phenomenon understood as evaporative cooling. Maintaining body temperature is a vital life-sustaining process. It is directly related to our health, whether it's in our daily lives or when we exercise. It is well known that sweating reduces body temperature. Still, there is a need to clarify how exactly the mechanism of thermoregulation by sweat relates to the ‘Heat Index’ depending on temperature and humidity conditions. Based on the fact that sweat droplets and pure water droplets have a compositional difference in salts of around 1%, Prof. Weon’s research team including Dr. Beigtan and Dr. Gonçalves, closely observed the evaporation of sweat droplets as a function of temperature and humidity. Their results report that, unlike pure water droplets, sweat droplets do not completely evaporate in hot and humid conditions, but instead undergo "incomplete evaporation" in which some water is retained. By measuring the heat transfer while sweat droplets undergo evaporation in different conditions, this team was the first to show that incomplete evaporation of sweat droplets is the physical source of high ‘Heat Index’ in humid environments. At low humidity, sweat droplets evaporate completely, leaving only sweat deposits, while at high humidity, both sweat deposits and moisture are retained. This is because at high humidity, sweat residue continuously absorbs moisture from the surrounding air. This incomplete evaporation reduces the efficiency of heat transfer by sweat evaporation, increasing the ‘Heat Index’ and reducing the body's ability to regulate its temperature via evaporative cooling. The understanding of how sweat droplets maintain body temperature, as revealed by this research, is expected to have far-reaching implications. It is crucial for human health, sports science, weather forecasting, and the development of functional materials, particularly in the context of the current climate crisis characterized by wet and hot weather, most recently called “global boiling”. The findings were published on April 16 as a cover story in Environmental Science & Technology, a prestigious journal in the field of environmental science by the American Chemical Society. This research was supported by Amorepacific's research grant. ※ Journal: Environmental Science & Technology (2024), Impact factor 11.4, JCR Top 6.7% in Environmental Science. ※ Paper title: Heat transfer by sweat droplet evaporation ※ DOI 10.1021/acs.est.4c00850 https://pubs.acs.org/doi/10.1021/acs.est.4c00850 ※ Co-first authors: Dr. Mohadese Beigtan and Dr. Marta Gonçalves ※ Corresponding author: Prof. Byung Mook Weon (Sungkyunkwan University - Department of Advanced Materials Science & Engineering) Research shows how incomplete evaporation of sweat droplets contributes to ‘Heat Index’ values. Cover paper, Published on April 16th
- No. 252
- 2024-06-13
- 621
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AI Influencer VS Human Influencer
Professor Hwang Se-rim's paper, which reveals the effectiveness of AI influencers, has been published in the May-June issue of Harvard Business Review (HBR), a prestigious business journal. Professor Hwang, along with Assistant Professor Shunyuan Zhang of Harvard University, Associate Professor Xiao Liu of New York University, and Professor Kannan Srinivasan of Carnegie Mellon University, analyzed over a million pieces of content over six years. Influencer marketing has been actively used due to its high marketing effect, but there have also been cases of backfires, and recently, there has been an increase in cases of brand marketing using AI influencers. The paper compared the effectiveness of human influencers and AI influencers in five aspects: engagement, reach, diversity, reputational risk, and cost. The study found that AI influencers were able to generate more engagement from people than human influencers. In particular, AI influencers were less likely to be exposed to scandals or bad reputations than human influencers, and they also cost less. This means that choosing AI influencers can be more cost-effective and also ensure high engagement from people. According to one survey, 52% of social media users in the United States already follow AI influencers, and this percentage is even higher worldwide. Among various industries, the fashion and beauty industries were more receptive to paid advertising posts by AI influencers, while people showed more resistance to paid advertising posts by human influencers. As the time spent consuming traditional media such as TV decreases, influencer marketing is expected to become even more important for brands. This study has proven that AI influencers have clear advantages over traditional human influencers. This means that brands should positively consider adopting AI influencers when introducing social media marketing. Paper: Harvard Business Review May–June 2024 Title: Should Your Brand Hire a Virtual Influencer? DOI: https://hbr.org/2024/05/should-your-brand-hire-a-virtual-influencer
- No. 251
- 2024-05-31
- 675
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Ontological Reflection on Hospital Spaces: Interpreting Hospitals through Heideggerian concept of Care and Dwelling
The significance of hospitals in contemporary human life continues to increase with advancements in scientific and medical technology. However, philosophical reflection on the fundamental existential meaning and role of hospital spaces is notably absent. Although hospitals have taken a central role in human existence, they are often perceived merely as technical treatment spaces focused on effectively treating illnesses and preventing infections. Hye Youn Park, a senior researcher at Hybrid Future Culture Institute and adjunct professor of philosophy, uses Descartes's concept of spatiality to critique the spatialization of disease in modern hospitals. Additionally, through Heidegger's discourse on technology, she offers fresh insight that the authentic mode of existence of hospitals is rooted in 'Care.' While 'care' has been used as a methodological concept to describe the practice of medicine or nursing, this study argues, through Heideggerian thought, that 'care' is the fundamental spatiality of the hospital. Furthermore, by connecting Heidegger's thoughts on dwellings with the spatiality of hospitals, this study critically examines the problems associated with hospital architecture and suggests new alternatives. "Through various discussions and critiques, I attempted to reflect on the ontology of contemporary hospital spaces and also laid academic and theoretical groundwork suggesting that hospital spaces, which possess distinct limitations regarding human existence, should be reconstructed," remarked Park regarding the study. "The significance of the study is that it is a theoretical discussion. It provides a catalyst for future interdisciplinary research on hospital spaces regarding architectural phenomenology while simultaneously proposing a new paradigm for hospital architecture that considers medical staff and patients," she added. Hye Youn Park is a member of the Hybrid Future Culture Institute, which conducts interdisciplinary research across the humanities to examine the issues facing our time and proposes practical alternatives. Hye Youn Park's findings have been published in the March 2024 issue of Medical Humanities, a scholarly journal in the field of Humanities, Multidisciplinary (IF 1.2, JCR top 1.8%), affiliated with the British Medical Journal. Additionally, an introduction to the study and its author, Hye-Youn Park, was also posted on the official blog of the journal. ※ Title: Hospital space interpreted according to Heidegger's concepts of care and dwelling ※ Journal: Medical Humanities ※ First & Corresponding author: Hye Youn Park (Hybrid Future Culture Institute and adjunct professor of philosophy) ※ DOI: 10.1136/medhum-2023-012696 ※Link to the journal's official blog: https://blogs.bmj.com/medical-humanities/2024/04/09/hospital-space-interpreted-according-to-heideggers-concepts-of-care-and-dwelling/
- No. 250
- 2024-05-21
- 963
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Development of fish skin-derived composite material-based bioinks and porous collagen bioinks
Bioprinting is a technology that produces artificial tissues/organs for medical purposes using bioinks containing cells and 3D printers, and is currently actively used in various regeneration, diagnosis, and emergency medical research, such as cancer mechanism research using artificial cancer models that simulate cancer tissues, as well as the production of artificial organs for transplantation. In particular, research is actively underway to improve the physical properties and biological properties of bioinks containing cells to produce the desired three-dimensional structure and/or to induce cell activity and differentiation. - Fabrication of cell structures for muscle regeneration using bioinks derived from fish skin and bidirectional photo-crosslinked bioprinting system Since bioinks are cell carriers and the basis for cell growth, they are mainly made of hydrogels, and in particular, bio-derived hydrogels such as collagen and decellularized extracellular matrix, which contain a lot of cell-active substances, should be used to promote cell activity and differentiation. In the case of currently used bio-derived hydrogels, most of them rely on collagen and decellularized extracellular matrix derived from mammals such as pigs. However, these mammalian-derived biomaterials have limitations such as high inflammatory response and low angiogenesis. In order to overcome these limitations, the research team (1st author: SeoYul Cho) led by Professor Geun Hyung Kim in School of Medicine has produced a composite bioink derived from fish skin using an extracellular matrix derived from seawater fish and an extracellular matrix derived from freshwater fish. Fish skin accounts for most of the by-products of fisheries generated during the processing process, and Professor Kim's research team used the discarded fish skin as a biomaterial to produce bioink for effective tissue regeneration. In particular, seawater fish contains abundant omega-3 fatty acids, which not only play an important role in promoting vascularization and anti-inflammatory responses, but also are known to enhance the expression of myogenic differentiation factors of stem cells in the process of myogenesis. However, extracellular matrix derived from seawater fish has a low denaturation temperature and low processability, so this research team produced a bioink that can be photo-crosslinked using an extracellular matrix derived from freshwater fish with a relatively higher denaturation temperature. In addition, the cells were contained in the bioinks and uniformly aligned to mimic the aligned structure of muscle tissue by inducing the shear stress in the printing nozzle using bidirectional photo-crosslinking during the printing process. As a result of applying the cell structure produced by applying a composite material-derived bioink to a bidirectional photo-crosslinked bioprinting system to an animal muscle damage model, it was confirmed that the efficacy of muscle tissue regeneration and muscle function recovery was improved compared to the existing mammalian-derived bioink, and the formation of neuromuscular junctions as well as blood vessels was also improved. On the other hand, the inflammatory response was found to be reduced. Prof. Kim said, "These fish-derived composite-based bioinks can complement the problems of existing mammalian-derived biomaterials and can be used as functional bioinks that can induce excellent angiogenesis and low inflammatory response, because they contain abundant omega-3 fatty acids. In addition, it has shown an excellent muscle regeneration effect through an animal muscle injury model, and it is expected that it can be used for the regeneration of various tissues such as skin or bone. In particular, the produced bioink can be applied to various systems using bioprinters, such as bidirectional photo-crosslinked bioprinting systems, and it is expected that it can be used for the regeneration of various complex tissues. In addition, it is expected that economic and environmental benefits can be derived from recycling fish skin, which was considered waste, into biomaterials.". Figure 1. Fish-derived composite-based bioink - Development of porous collagen bioink with improved shape processability and bioprinting platform for bone tissue regeneration that mimics the hierarchy of bone microenvironment Natural hydrogels such as collagen are limited in their application to bioprinting due to their lack of physical properties. In addition, for the smooth supply of oxygen and nutrients in artificial tissues containing cells, it is essential to have a porous structure that serves as a channel for the circulation of the culture medium containing nutrients and oxygen every 2~300 micrometers. To this end, hydrogel-based bioinks have been stacked in the form of a mesh using bioprinting technology, or air has been injected into the bioinks to have their own porous structures. However, most of the existing manufacturing methods have clear limitations, such as limited cell activity or reduced physical properties due to the injected air, and in particular, they are limited in properly mimicking the microstructure of living tissues such as bone hierarchy and vascularization. To overcome these limitations, the research team (1st author: YoungWon Koo) led by Professor GeunHyung Kim has developed a collagen-based bioink with a micro-porous structure that greatly improves three-dimensional shape processability. Professor Kim said, "The significance of this study is to overcome the limitations of bioinks in existing bioprinting technologies and to develop a new concept of bioink that balances the two most important properties of bioinks, namely processability and biological functions, and it is expected that it will be possible to depict the details of vascularized living organs and simulate their 3D structures, which were difficult in the past. In the future, it is also expected that it can be directly applied to various disease researches, including more various tissue regeneration studies and biochips that simulate the cancer development environment due to their excellent physical and biological properties.". Figure 2. Porous Collagen Bioink The results of the above research were supported by the Korea National Institute of Health research project and also supported by a grant from the Ministry of Trade, Industry & Energy (MOTIE, Korea) under Industrial Technology Innovation Program, and are scheduled to be published in an international journal, Applied Physics Reviews (1st author: SeoYul Cho, IF=15.0)*, and published online on February 28 in Advanced Functional Materials (1st author: YoungWon Koo, IF=19.0)**, respectively,. *Research title: Bioengineered Cell-constructs Using Decellularized Fish Skin-Based Composite Bioink for Regenerating Muscle Tissue **Research title: An Approach for Fabricating Hierarchically Porous Cell‐Laden Constructs Utilizing a Highly Porous Collagen‐Bioink
- No. 249
- 2024-05-09
- 980
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Development of MXene Hybrid Material with Stealth Function of Microwave Absorption
A research team led by Professor Chong Min Koo of the Department of Advanced Material Engineering at Sungkyunkwan University (President Yoo Ji-beom) announced on the 4th that they have developed an electromagnetic wave absorbing material that can be used in stealth* defense technology and electromagnetic wave shielding technology of high-intensity communication/electronic devices. * Stealth technology: A technology that absorbs electromagnetic waves and prevents them from appearing on radar images, making it difficult to detect aircraft and missiles early by radar. The development of an electromagnetic wave absorbing material is attracting a lot of attention as a stealth technology that disables radar detection and a technology essential for blocking and removing harmful electromagnetic waves from communication/electronic devices. Currently, domestic stealth fighter paint technology relies on foreign countries for a large part, so research and development are needed. In order to develop electromagnetic wave absorbing materials for high-density electronic devices, it is necessary to develop material that is light, thin, and excellent in coating processability. Accordingly, the research team led by Professor Chong Min Koo at Sungkyunkwan University developed a material with efficient stealth performance and electromagnetic absorption characteristics using a self-assembled structure of two-dimensional nanomaterial MXene and zeolitic imidazolate framework (ZIP). Using MXene's negative surface charge and ZIF' positive surface charge, the research team produced a material with self-assembled hybrid nanostructure originated from electrostatic interaction. This material has a very strong built-in electric field (BIEF) formed at the heterogeneous interface due to the opposite (negative and positive) surface charge characteristics of each nanomaterial. Strong dielectric loss induced by the internal electric field resulted in a 2.5mm thick stealth performance (RL) in the X-band (8-12 GHz) frequency and excellent electromagnetic absorption properties and stealth performance with 47.5 dB with an effective bandwidth of 6.3 GHz. The research team confirmed that the developed MXene nanomaterial exhibits excellent electromagnetic wave shielding and absorption performance in a wide range of frequencies from low-frequency radio waves (RF) to X-band, terahertz, and infrared rays. By utilizing this, it can be used not only for stealth applications but also for EMI shielding applications of communication/electronic devices, infrared stealth, and infrared counterfeiting prevention. Professor Chong Min Koo at Sungkyunkwan University explained, "MXene nanomaterials can be used as stealth materials for business of the domestic KF-21 stealth fighter production in the future. In addition, they can be used as electromagnetic wave absorbing materials for state-of-the-art, highly integrated electronic device and electric vehicles. This work was financially supported by National Research Foundation of Korea(NRF) grant, Nano·Material Technology Development Program, funded by the Ministry of Science, ICT and Future Planning, and POSCO's research project. This work was published in the journal of Advanced Materials (IF: 29.4) and Nature Reviews Electrical Engineering at the same time. 1. Zhenguo Gao, Aamir Iqbal, Tufail Hassan, Shengchong Hui, Hongjing Wu*, Chong Min Koo*, “Tailoring Built‐in Electric Field in a Self‐Assembled Zeolitic Imidazolate Framework/MXene Nanocomposites for Microwave Absorption”, Advanced Materials 2024, 2311411 (https://doi.org/10.1002/adma.202311411) 2. Aamir Iqbal, Tufail Hassan, Shabbir Madad Naqvi, Yury Gogotsi, Chong Min Koo*, "MXenes for multispectral electromagnetic shielding”, Nature Reviews Electrical Engineering 2024, 1, 180-198. [Figure 1] MXene two-dimensional nanomaterial structure and excellent electromagnetic wave shielding effect in a wide frequency range from radio waves to infrared rays. [Figure 2] Electrostatically self-assembled structure of MXene-ZIF nanocomposite with an artificial built-in electric field (BIEF) at its heterointerfaces. [Figure 3] The effect of internal electric field (BIEF) at the interface of MXene-ZIF hybrid and their excellent microwave absorbing (RL) performances.
- No. 248
- 2024-04-30
- 1044
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Development of two novel methodologies for efficient representation of complex 3D scenes
The research team led by professors Eunbyung Park and Jong Hwan Ko in the Department of Electronic and Electrical Engineering has proposed two innovative media representation methods that efficiently reconstruct complex 3D scenes using a new model structure based on neural fields. The first methodology integrates neural networks with the traditional grid-based representation method in a novel way, while the second involves representing scenes through compact 3D Gaussian representations. 1) Coordinate-Aware Modulation (CAM) To represent 3D images or videos, typical methods extract features from a grid and then process them through a neural network. On the other hand, the approach proposed in this work fuses the feature of the grid into each layer of the neural network through a modulation operation. While the conventional use of grids requires large storage, this method uses very small grids and efficiently represents high-frequency signals. [Figure 1] Architecture of the proposed CAM This novel method developed by the research team has demonstrated its high performance with a significantly smaller network size when applied to various media data such as images, videos, 3D models, and 3D videos. [Figure 2] Visualization of CAM on different domains [Figure 3] Performance evaluation on different domains 2) Compact 3D Gaussian Splatting (C3DGS) Recently, it became possible to achieve fast rendering speeds of over 100 FPS by representing 3D spaces as 3D Gaussian points. However, this scene representation technique requires a very large storage capacity. The research team successfully reduced the number of Gaussians used to represent space dramatically without decreasing rendering performance. Additionally, by introducing a new methodology for representing Gaussians, this method achieved not only high performance and fast rendering but also a very efficient reduction in storage space requirements. [Figure 4] Scene representation with 3D Gaussians and C3DGS In performance evaluations conducted with various real-world datasets, the method proposed by the research team resulted in more than a 25-fold decrease in storage requirements and an improvement in rendering speed, without compromising rendering quality. [Figure 5] Performance evaluation on various datasets Prof. Eunbyung Park remarked, "We have developed novel methodologies capable of representing complex 3D scenes efficiently through an innovative structure that moves away from conventional approaches. These methodologies hold significant potential for effective application in currently popular areas such as NeRF or generative models." The research team's first study was accepted for publication at ICLR 2024 (International Conference on Learning Representations), considered one of the top academic conferences in the machine learning field alongside NeurIPS and ICML. It was selected for the Spotlight, which represents the top 6% of submitted papers. Additionally, the second study was accepted for publication at CVPR 2024 (The IEEE/CVF Conference on Computer Vision and Pattern Recognition), which is recognized as the premier academic conference in the field of computer vision. This paper was selected as a Highlight, representing the top 3% of submissions. Paper title: Coordinate-Aware Modulation for Neural Fields Research homepage: https://maincold2.github.io/cam/ Authors: Joo Chan Lee (First author, integrated Master's and PhD program in Dept. of Artificial Intelligence), Daniel Rho (Master's graduate in Dept. of Artificial Intelligence, currently at KT), Seungtae Nam (PhD candidate in Dept. Artificial Intelligence), Jong Hwan Ko (Corresponding author, professor in the Dept. of Electronic and Electrical Engineering), Eunbyung Park (Corresponding author, professor in the Dept. of Electronic and Electrical Engineering) Paper title: Compact 3D Gaussian Representation for Radiance Field Research homepage: https://maincold2.github.io/c3dgs/ Authors: Joo Chan Lee (First author, integrated Master's and PhD program in Dept. of Artificial Intelligence), Daniel Rho (Master's graduate in Dept. of Artificial Intelligence, currently at KT), Xiangyu Sun (PhD candidate in Dept. of Electrical and Computer Engineering), Jong Hwan Ko (Corresponding author, professor in the Dept. of Electronic and Electrical Engineering), Eunbyung Park (Corresponding author, professor in the Dept. of Electronic and Electrical Engineering)
- No. 247
- 2024-04-24
- 1124
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Predicting and demonstrating of hidden metastable phase in transition metal oxide
Prof. Jaichan Lee, a professor in the School of Advanced Materials Science and Engineering at Sungkyunkwan University, theoretically predicted the hidden metastable phase in transition metal oxides and experimentally demonstrated it on thin film surfaces. This research predicts and demonstrates the charge-ordered phase, recognized as a fundamental stage for triggering novel functional properties such as superconductivity, colossal magnetoresistance, and multiferroicity. While charge ordering phase transitions have previously been reported in transition metal oxides with highly occupied d orbitals of transition metal cations, this study introduces a significant counterexample. Both theoretical predictions and experimental demonstration confirm the stable presence of charge-ordered phases on the surface of thin films, even within transition metal oxide have low electron occupancy in the d orbitals of transition metal cations. This research holds substantial scientific significance as it reveals that charge ordering can potentially manifest across the complete region of 3d transition metal oxides found on the periodic table. The material studied in this work, strontium titanate (SrTiO3), is a prototypical perovskite transition metal oxide that has been notable for significant novel functional properties, such as the first reported compound oxide superconductor. However, strontium titanate shows relatively weak electron-electron interactions and electrons-lattice coupling, owing to its lowest electron occupancy within the d orbitals of the transition metal titanium. This inherent characteristic of strontium titanate has consequently limited its application as a strongly correlated material for instigating novel functional properties. The researchers initially used the first-principles calculations, to theoretically predict the presence of the charge-ordered metastable phase in lanthanum-doped strontium titanate. Subsequently, they experimentally fabricated lanthanum-doped strontium titanate thin films with a atomically flat surface on strontium titanate (001) substrate, and validiated the stabilization of the metastable charge-ordered phase on the surface of the thin film. The surface triggered stabilization of the charge-ordered phase is both experimentally verified and theoretically predicted by first-principles calculations. Prof. Jaichan Lee explained that the research approach in this study to stabilize metastable phase using a thin film surface is expected to be a fundamental platform to investigate significant novel functional properties induced from charge ordering, such as superconductivity, colossal magnetoresistance, and multiferroicity. This work was supported by the National Research Foundation of Korea and KISTI Supercomputing Center. The research was published in the international multidisciplinary science journal Nature Communications on 8th February. ※Journal: Nature Communications ※Title: Surface triggered stabilization of metastable charge-ordered phase in SrTiO3 ※DOI: 10.1038/s41467-024-45342-8 ※Author list - Corresponding author: Prof. Jaichan Lee, Prof. Chang-Beom Eom - Co-first author: Prof. Kitae Eom, Bongwook Chung - Co-author: Sehoon Oh, Hua Zhou, Jinsol Seo, Sang Ho Oh, Jinhyuk Jang, Si-Young Choi, Minsu Choi, Ilwan Seo, Yun Sang Lee, Youngmin Kim, Hyungwoo Lee, Jung-Woo Lee, Kyoungjun Lee, Mark Rzchowski ▲The verification of the surface triggered charge-ordered phase on the lanthanum-doped strontium titanate thin film surface.
- No. 246
- 2024-04-11
- 1503
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Development of High-Performance Flexible Energy Storage Materials Based on Low-Temperature Plasma
Professor Taesung Kim's research team from the Department of Mechanical Engineering/Department of Nanoscience and Technology/Department of Semiconductor Convergence Engineering, along with Professor Jin Kon Kim's research team at POSTECH and Professor Hong Chul Moon's research team at University of Seoul, have announced the development of a new concept synthesis process technology for producing mesoporous transition metal oxides on flexible substrates by utilizing the synergy effect of low-temperature plasma and thermal processes. Mesoporous metal oxides (MMOs) possess highly advantageous properties such as high surface area and porosity, making them widely used in high-performance energy storage/conversion, sensors, catalysis, etc. However, the conventional synthesis methods require high-temperature sintering processes, making it impossible to synthesize directly on flexible substrates. The widely used soft-template method for MMO fabrication involves the self-assembly of organic support and inorganic precursor to form organic-inorganic composites, followed by the removal of the organic support and the reaction of the inorganic precursor, which traditionally necessitates high-temperature sintering. In this study, the use of low-temperature plasma was employed to lower the synthesis temperature, addressing these issues. The synergy effect between heat and plasma enabled rapid synthesis of various types of MMOs at temperatures of 150-200°C. Additionally, mesoporous vanadium pentoxide (V2O5) was synthesized on a polyimide substrate, realizing flexible energy storage devices. Professor Taesung Kim of Sungkyunkwan University, who developed the low-temperature plasma-based synthesis technology, stated, "The discovery of a method to directly synthesize on flexible substrates in this research will present a new paradigm in the field of smart energy storage/conversion devices." This research was supported by the Ministry of Science, ICT and Future Planning's Creative-Pioneering Researchers Program, Basic Research Program in the field of Science and Technology, and the Nano and Material Technology Development Program (Nano Convergence) and was published in the international journal Advanced Materials on January 19th. ※ Paper Title: Low-Temperature, Universal Synthetic Route for Mesoporous Metal Oxides by Exploiting Synergistic Effect of Thermal Activation and Plasma ※ Authors: Taesung Kim, Jin Kon Kim, Hong Chul Moon (Corresponding author), Geon Woo Kim, Hyun Ho Seok (Co-first authors) ※ DOI: 10.1002/adma.202311809 ■ Development of High-Performance Flexible Energy Storage Materials Based on Low-Temperature Plasma ■ The research was led by Professor Tae Sung Kim from the Department of Mechanical Engineering (corresponding author), and Hyun Ho Seok, a doctoral candidate (first author)
- No. 245
- 2024-04-02
- 1242
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Measuring the economic efficiency in Biotechnology
Prof. Woo Han Min, a professor in the Department of Food and Life Science at Sungkyunkwan University, has pioneered the development of an Experiment Price Index (EPI) that quantifies the economic efficiency of the biofoundry technology based on laboratory automation, which is a core manufacturing technique in synthetic biology. This groundbreaking index is the first of its kind globally. The biofoundry technology, akin to custom semiconductor production systems, allows for the design and automation of biological systems. It enables the rapid development of synthetic biology components and cell factories. The Experiment Price Index (EPI) considers research material costs, labor expenses, and the time required for experiments per sample, expressed as the geometric mean. Lower EPI values indicate greater efficiency. Prof. Woo Han Min’s work in quantifying the efficiency of biofoundry through the Experiment Price Index provides a foundation for economically designing and executing large-scale synthetic biology experiments using high-cost automated robots. According to experiments conducted at the Sungkyunkwan University biofoundry Research Center, when comparing 625 synthetic biology experiments (such as gene assembly) performed by human researchers and biofoundry research robots, the latter exhibited approximately twice the efficiency per sample compared to human researchers. Notably, biofoundry research robots reduced experiment time by more than three fold, ultimately demonstrating the capability equivalent to three or more human researchers. This achievement is expected to contribute to the economical establishment of biofoundry infrastructure, especially as biofoundry facilities continue to advance, leading to even higher efficiency Experiment Price Index values. Prof. Woo Han Min envisions that this index will play a crucial role in commercializing synthetic biology-based products by allowing cost-effective planning and execution of large-scale experiments. The research results were published in the online edition of Trends in Biotechnology, a prestigious journal in the field of biotechnology. ※ Journal: Trends in Biotechnology(2024), Impact factor 17.3 (2022), JCR(Journal Citation Reports) Top 1.6% Journals in the Fields of Biotechnology and Applied Microbiolgy ※ Title: Measuring the economic efficiency of laboratory automation in biotechnology ※ DOI: 10.1016/j.tibtech.2024.02.001 ※ 제1저자 및 교신저자: Prof. Woo Han Min(SKKU Synthetic Biology, BioFoundry, Metabolic Engineering) ▲ Measuring the economic efficiency in biotechnology
- No. 244
- 2024-03-27
- 1032
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Developed the AI-based tools for identification of virus-induced phosphorylation sites and 2OM sites in human RNA
The CBBL team led by Prof. Balachandran Manavalan at the Department of Integrative Biotechnology, developed two cutting-edge AI-based tools for identification of virus-induced phosphorylation sites and 2OM sites in human RNA. Their innovative approach was published in the top-tier journal Briefings in Bioinformatics (Impact factor 9.5 & JCR = 3). The two methods are as follows: 1. Identification of virus-induced phosphorylation sites using meta-learning approach The global spread of the coronavirus (SARS-CoV-2) has caused significant concern and challenges to global health. Phosphorylation is a common post-translational modification that affects many vital cellular functions and is closely associated with SARS-CoV-2 infection. Accurate identification of phosphorylation sites could provide more in-depth insight into the processes underlying SARS-CoV-2 infection and help alleviate the continuing COVID-19 crisis. However, currently available computational methods in predicting these sites lack accuracy and effectiveness. My team, in collaboration with departmental colleagues including Prof. Young-Jun Jeon, Prof. Minkyung Song, and Prof. Sukchan Lee, developed the novel MeL-STPhos predictor using a meta-learning approach (Figure 1). Specifically, my two PhD students, Nhat Truong Pham and Le Thi Phan created two cell-specific datasets and a generic one using data from Nature and Cell publications. We built a large-scale baseline model (~400) for each dataset, by exploring 29 feature descriptors and 14 different classifiers. The top-performing model from each descriptor was then combined and re-trained for the final prediction. Interestingly, MeL-STPhos generic model has the capability of identifying phosphorylation caused by other viruses, not only SARS-CoV2. Additionally, one cell-specific model accurately detects Threonine phosphorylation sites, showcasing the necessity of multiple models. MeL-STPhos significantly outperformed the best predictor on both datasets, demonstrating the importance of our systematic approach in exploiting different feature descriptors, classifiers, and meta-learning approach, which is responsible for such improved performance. Figure 1. Overview of MeL-STPhos framework. This computational framework includes four steps: Dataset preparation, meta-learning approach, identification of optimal features and classifiers, and web server development. This research was conducted with the support of the Korea Health Technology R&D Project grant through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HI23C0701); National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2021R1A2C1014338, RS-2023-00217881 and 2021R1C1C1007833) and the result was published in the Briefings in Bioinformatics (https://doi.org/10.1093/bib/bbad433) on December 06, 2023. 2. Identification of 2’-O-methylation sites in human RNA using hybrid deep learning framework 2’-O-methylation (2OM) is the most common post-transcriptional modification of RNA, which plays a crucial role in RNA splicing, RNA stability, and innate immunity. Despite advances in high-throughput detection, the chemical stability of 2OM makes it difficult to detect and map in messenger RNA. While a few bioinformatics tools have made significant advancements in this area, there is still a need for greater accuracy and improvement. My PhD student, Nhat Truong Pham, has developed H2Opred, a novel hybrid learning approach (Figure 2), for accurately identifying 2OM sites. H2Opred incorporated both stacked 1D convolutional neural network (1D-CNN) blocks and stacked attention-based bidirectional gated recurrent unit (Bi-GRU-Att) blocks. 1D-CNN blocks learned effective feature representations from 14 conventional descriptors, while Bi-GRU-Att blocks learned feature representations from five natural language processing-based embeddings extracted from RNA sequences. H2Opred integrated these feature representations to make the final prediction. Moreover, the generic model of H2Opred demonstrated a remarkable performance on both training and testing datasets, significantly outperforming the existing predictor and other four nucleotide specific H2Opred models. Figure 2. Overview of H2Opred framework. This computational framework includes three steps: Dataset preparation, feature extraction and model construction, and feature fusion and web server development. This research was conducted with the support of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2021R1A2C1014338 and 2021R1I1A1A01056363), and Korea Health Technology R&D Project grant through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HI23C0701) and the result was published online in the Briefings in Bioinformatics (https://doi.org/10.1093/bib/bbad476) on January 04, 2024. These approaches are not limited in identifying only 2OM or phosphorylation sites. They can also be applied to other research areas, including identification of peptide therapeutic functions and Alzheimer's disease (AD) prediction using gene expression data.
- No. 243
- 2024-03-13
- 4540
