- Complex Network Analysis Techniques
- Opinion Dynamics and Social Influence
- Nonlinear Dynamics and Pattern Formation
- Theoretical and Computational Physics
- Stochastic processes and statistical mechanics
- Evolutionary Game Theory and Cooperation
- Tactile and Sensory Interactions
- Smart Grid and Power Systems
- Power System Optimization and Stability
- Energy Load and Power Forecasting
- Neural Networks Stability and Synchronization
- Energy and Environmental Systems
- Power Systems and Technologies
- stochastic dynamics and bifurcation
- Evolution and Genetic Dynamics
- Teleoperation and Haptic Systems
- Complex Systems and Time Series Analysis
- Neural dynamics and brain function
- Block Copolymer Self-Assembly
- COVID-19 epidemiological studies
- Human Mobility and Location-Based Analysis
- Engineering Applied Research
- Distributed and Parallel Computing Systems
- Slime Mold and Myxomycetes Research
- Transportation Planning and Optimization
Hanyang University
2014-2024
Korea University
2023-2024
Asia Pacific Center for Theoretical Physics
2018-2023
Kongju National University
2023
Daegu Gyeongbuk Institute of Science and Technology
2021-2022
Gyeongsang National University
2022
Yonsei University
2022
University of Calgary
2010-2021
Samsung (South Korea)
2021
Korea Advanced Institute of Science and Technology
2002-2019
We consider percolation on interdependent locally treelike networks, recently introduced by Buldyrev et al., Nature 464, 1025 (2010), and demonstrate that the problem can be simplified conceptually deleting all references to cascades of failures. Such do exist, but their explicit treatment just complicates theory -- which is a straightforward extension usual epidemic spreading single network. Our method has added benefits it directly formulated in terms an order parameter its modular...
Abstract Hardware-based cryptography that exploits physical unclonable functions is required for the secure identification and authentication of devices in Internet Things. However, are typically based on anticounterfeit identifiers created from randomized microscale patterns or non-predictable fluctuations electrical response semiconductor devices, validation an encrypted signature relies a single-purpose method such as microscopy measurement. Here we report nanoscale function labels...
To identify communities in directed networks, we propose a generalized form of modularity networks by introducing new quantity LinkRank, which can be considered as the PageRank links. This generalization is consistent with original undirected and optimization methods developed for directly applied to optimizing our modularity. Also, model network, used benchmark network further community studies, proposed verify method. Our method supposed find effectively citation- or reference-based networks.
We study four Achlioptas type processes with "explosive" percolation transitions. All transitions are clearly continuous, but their finite size scaling functions not entire holomorphic. The distributions of the order parameter, relative $s_{\rm max}/N$ largest cluster, double-humped. But -- in contrast to first phase distance between two peaks decreases system $N$ as $N^{-\eta}$ $\eta > 0$. find different positive values $\beta$ (defined via $< s_{\rm max}/N \sim (p-p_c)^\beta$ for infinite...
Recent advance of high-power laser processing allows for rapid, continuous, area-selective material fabrication, typically represented by crystallization silicon or oxides display applications. Two-dimensional materials such as graphene exhibit remarkable physical properties and are under intensive development the manufacture flexible devices. Here we demonstrate an ultrafast nanofabrication method using low intensity infrared visible irradiation to direct self-assembly block copolymer films...
To isolate and identify antioomycete substances from Fusarium oxysporum EF119 against Phytophthora infestans to investigate their antimicrobial activities various plant pathogenic bacteria, oomycetes true fungi.Two were isolated liquid cultures of F. EF119, which shows a potent disease control efficacy tomato late blight caused by P. infestans. They identified as bikaverin fusaric acid mass nuclear magnetic resonance spectral analyses. inhibited the mycelial growth fungi. Fusaric also...
Aims: To isolate endophytic fungi from vegetable plants and examine their in vivo anti‐oomycete activity against Phytophthora infestans tomato plants. Methods Results: Endophytic were isolated surface‐sterilized plant tissues was measured by assay using seedlings. showing potent identified morphological characteristics nuclear ribosomal ITS1‐5.8S‐ITS2 sequence analysis. A total of 152 isolates obtained 66 healthy tissue samples cucumber, red pepper, tomato, pumpkin Chinese cabbage the...
We study a model for coupled networks introduced recently by Buldyrev et al., [Nature (London) 464, 1025 (2010)], where each node has to be connected others via two types of links viable. Removing critical fraction nodes leads percolation transition that been claimed more abrupt than uncoupled networks. Indeed, it was found discontinuous in all cases studied. Using an efficient new algorithm we verify the is Erdös-Rényi networks, but find continuous fully interdependent diluted lattices. In...
When a new facility like grocery store, school, or fire station is planned, its location should ideally be determined by the necessities of people who live nearby. Empirically, it has been found that there exists positive correlation between and population densities. In present work, we investigate ideal relation densities within framework an economic mechanism governing microdynamics. previous studies based on global optimization positions in minimizing overall travel distance facilities,...
Abstract In a system of heterogeneous (Abelian) Kuramoto oscillators with random or ‘frustrated’ interactions, transitions from states incoherence to partial synchronization were observed. These so-called volcano are characterized by change in the shape local field distribution and discussed connection an oscillator glass. this paper, we consider different class oscillators, namely (non-Abelian) SU(2)-Lohe that can also be defined on 3-sphere, i.e. is generalized as unit vector...
Abstract Here, spontaneous lamellar alignment in a thickness‐modulated block copolymer film is presented as facile, scalable, and general approach for creating highly aligned morphology. Thickness‐modulated films are prepared on neutral surfaces by various methods, such solution dropping, dewetting‐induced self‐organized patterning, thermal imprinting. Regardless of the preparation method, self‐assembled domains become spontaneously along thickness gradient after sufficient annealing....
Highly aligned metal nanowire arrays with feature sizes approaching 10 nm are fabricated. This is made possible by the self-assembly of block copolymers (BCPs) on graphene-wrinkle arrays. Thickness-modulated BCP films confined wrinkled reduced graphene oxide (rGO) surface promote strict alignment self-assembled lamellae in direction film thickness gradient. As a service to our authors and readers, this journal provides supporting information supplied authors. Such materials peer reviewed may...
Spreading processes on networks are ubiquitous in both human-made and natural systems. Understanding their behavior is of broad interest; from the control epidemics to understanding brain dynamics. While some cases there exists a clear separation time scales between propagation single spreading cascade initiation next -- such that can be modelled as directed percolation or branching process also for which this not case, zoonotic diseases spiking cascades neural networks. For large class...
A highly sensitive and flexible gas sensor that can detect a wide range of chemicals is crucial for wearable applications. However, conventional single resistance-based sensors face challenges in maintaining chemical sensitivity under mechanical stress be affected by interfering gases. This study presents versatile approach fabricating micropyramidal ion gel sensor, which accomplishes sub-ppm (<80 ppb) at room temperature discrimination capability between various analytes, including toluene,...
We investigate how we can improve the synchronizability of complex networks simply by changing link direction while conserving local weights and topology. Performing linear stability analysis synchronization numerical simulation Kuramoto model in directed networks, find that a random assignment directions generally weakens degree synchronization, properly organized directionality systematically enhance network synchronization. In this respect, suggest simple method according to larger...
We proposed a method called residual edge-betweenness gradient (REBG) to enhance synchronizability of networks by assignment link direction while keeping network topology and weight unchanged. Direction has been shown improve the undirected in general, but we find that some cases incommunicable components emerge fail synchronize. show REBG can effectively avoid synchronization failure ($R=\lambda_{2}^{r}/\lambda_{N}^{r}=0$) which occurs degree (RDG) Phys. Rev. Lett. 103, 228702 (2009)....
Network science enables us to improve the performance of complex systems such as traffic, communication, and power grids. To do so, it is necessary use a well-constructed flawless network dataset associated with system interest. In this study, we present Chilean grid. We harmonized data from three diverse sources generate unified dataset. Through an intensive review on raw data, filter out inconsistent errors unrealistic faults, making more trustworthy. contrast other for grids, especially...
Tactile sensation is essential for many exploration and manipulation tasks not only in a real environment but also virtual environment. We suggest the design of an integrated tactile display system that provides kinesthetic force, pressure distribution, vibration slip/stretch. The consists two parts: 2 DOF force feedback device displaying normal stimulation to skin Psychophysical experiments measure effects fingerpad selection, direction finger movements texture width on sensitivity....
Complex network analyses have provided clues to improve power-grid stability with the help of numerical models. The high computational cost simulations, however, has inhibited approach, especially when it deals dynamic properties power grids such as frequency synchronization. In this study, we investigate machine learning techniques estimate We test three different algorithms-random forest, support vector machine, and artificial neural network-training them two types synthetic consisting...
Knowledge distillation is an effective method for training lightweight models, but it introduces a significant amount of computational overhead to the cost, as requires acquiring teacher supervisions on samples. This additional cost -- called most pronounced when we employ large-scale models such vision transformers (ViTs). We present MaskedKD, simple yet strategy that can significantly reduce distilling ViTs without sacrificing prediction accuracy student model. Specifically, MaskedKD...