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A Miniaturized Crawler Design Based on an Origami-inspired and Geometrically Constrained Spherical Six-bar Linkage

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Journal of Bionic Engineering 2024年第1期21卷 166-176页

作者： Subin Chae Gwang-Pil jung Department of Mechanical and Automotive Engineering Seoul National University of Science and TechnologySeoul 01811South Korea

This paper focuses on a newly developed transmission for a milli-scale eight-legged crawling robot called *** transmission allows intuitive steering by directly changing the direction of the propulsion *** transmission is based on the constrained spherical six-bar *** constrained spherical six-bar linkage passes only reciprocating motion out of the motor’s rotating motion,allowing the crawling legs to kick the ground and obtain *** is achieved by adjusting the geometric constraints of the spherical six-bar using a servomotor,allowing the direction of propulsion to be *** a result,the OriSCO can move along the ground at a speed of 2.15 body lengths/s,and the robot is 60 mm long.

关键词： Bio-inspired robot Crawler:Crawling robot Direction change Spherical six-bar linkage

Design-space adaptation method for multiobjective and multidisciplinary optimization

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Chinese Journal of Aeronautics 2024年第8期37卷 166-189页

作者： Jongho jung Kwanjung YEE Shinkyu JEONG Department of Aerospace Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Mechanical Engineering Kyunghee UniversityYoungin 17104Republic of Korea

This paper developed a new method that adaptively adjusts a design space by considering the actual solution distribution of a problem to overcome the conventional design-space adaptation method that assumes the solutions distribution to be a normal distribution because the distributions of solutions are rarely normal distributions for real-world *** developed method was applied to nineteen multiobjective test functions that are widely used to evaluate the characteristics and performance of optimization *** results showed that this method adapted the design space to an appropriate design space where the solution existence probability was *** optimization performance achieved using the developed method was higher than that of the conventional ***,the developed method was applied to the conceptual design of an unmanned spacecraft to confirm its validity in real-world design and multidisciplinaryoptimization *** results showed that the Pareto solutions of the developed method were superior to those of conventional ***,the optimization efficiency with the developed method was improved by more than 1.4 times over that of the conventional *** this regard,the developed method has the potential to be applied to complicated real-world optimization problems to achieve better performance and efficiency.

关键词： Multiobjective optimization Multiobjective genetic algorithm Design-space adaptation Multidisciplinary optimization Hypersonic vehicle

Boron-10 stimulated helium production and accelerated radiation displacements for rapid development of fusion structural materials

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Journal of Materiomics 2024年第2期10卷 377-385页

作者： Yunsong jung Ju Li Department of Nuclear Science and Engineering and Department of Materials Science and Engineering Massachusetts Institute of TechnologyCambridgeMA02139USA Korea Institute of Fusion Energy Daejeon34133Republic of Korea

Boron doping,combined with neutron capture in fission reactors,has been used to simulate the helium effect on fusion structural ***,inhomogeneous helium bubble formation was often observed due to boron segregation to grain *** excess radiation displacements due to^(10)B(n,α)^(7)Li reaction,the high-energy lithium and helium ions,also were not accounted for,which can significantly accelerate the displacements-per-atom(dpa)accumulation alongside helium production(appm).Hereby an isotopically pure^(10)B doping approach is proposed to simulate the extreme envi-ronment inside fusion reactors with a high He appm-to-dpa ratio of about 10,which is about 10^(2)×larger than in fission *** modeling showed that~13%of total radiation displacement was induced by^(10)B(n,α)^(7)Li in the case of 1000 appm^(10)B doped Fe samples,which becomes even greater with increasing^(10)B *** homogenous radiation damage and helium generation are pre-dicted for grain sizes less than 1 mm,even if the boron partially formed precipitates or segregates on grain *** studies with various^(10)B doping(and^(235)U-codoping)levels in research reactors showed the estimated helium generation and radiation damage would significantly mimic fusion conditions and greatly expedite fusion materials testing,from many years down to months.

关键词： Fusion power reactor Helium transmutation He appm-to-dpa ratio Boron-10 doping Accelerated materials testing

A Transfer Function Design for Medical Volume Data Using a Knowledge Database Based on Deep Image and Primitive Intensity Profile Features Retrieval

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Journal of Computer Science & Technology 2024年第2期39卷 320-335页

作者： Younhyun jung Jim Kong 盛斌 Jinman Kim School of Computing Gachon UniversitySeongnam 13120Korea School of Computer Science The University of SydneySydney 2006Australia Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Direct volume rendering(DVR)is a technique that emphasizes structures of interest(SOIs)within a volume visually,while simultaneously depicting adjacent regional information,e.g.,the spatial location of a structure concerning its *** DVR,transfer function(TF)plays a key role by enabling accurate identification of SOIs interactively as well as ensuring appropriate visibility of *** generation typically involves non-intuitive trial-and-error optimization of rendering parameters,which is time-consuming and *** at mitigating this manual process have led to approaches that make use of a knowledge database consisting of pre-designed TFs by domain *** these approaches,a user navigates the knowledge database to find the most suitable pre-designed TF for their input volume to visualize the *** these approaches potentially reduce the workload to generate the TFs,they,however,require manual TF navigation of the knowledge database,as well as the likely fine tuning of the selected TF to suit the *** this work,we propose a TF design approach,CBR-TF,where we introduce a new content-based retrieval(CBR)method to automatically navigate the knowledge *** of pre-designed TFs,our knowledge database contains volumes with SOI *** an input volume,our CBR-TF approach retrieves relevant volumes(with SOI labels)from the knowledge database;the retrieved labels are then used to generate and optimize TFs of the *** approach largely reduces manual TF navigation and fine *** our CBR-TF approach,we introduce a novel volumetric image feature which includes both a local primitive intensity profile along the SOIs and regional spatial semantics available from the co-planar images to the *** the regional spatial semantics,we adopt a convolutional neural network to obtain high-level image feature *** the intensity profile,we extend the dynamic time warping technique to address subtle alignment

关键词： data retrieval direct volume rendering ray analysis transfer function

Comparison of a Spectral Bin and Two Multi-Moment Bulk Microphysics Schemes for Supercell Simulation:Investigation into Key Processes Responsible for Hydrometeor Distributions and Precipitation

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Advances in Atmospheric Sciences 2024年第5期41卷 784-800页

作者： Marcus JOHNSON Ming XUE Youngsun jung Center for Analysis and Prediction of Storms University of OklahomaNormanOK 73072USA School of Meteorology University of OklahomaNormanOK 73072USA Office of Science and Technology Integration National Weather ServiceSilver SpringMD 20910USA

There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical *** supercell simulations are produced using the WRF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)***-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain ***-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the *** limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the *** from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the *** HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice ***,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the ***,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral *** results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design.

关键词： precipitation spectral bin microphysics bulk microphysics parameterization microphysics processes WRF model supercell storm

Adverse effects of early-life stress:focus on the rodent neuroendocrine system

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Neural Regeneration Research 2024年第2期19卷 336-341页

作者： Seung Hyun Lee Eui-Man jung Department of Molecular Biology College of Natural SciencesPusan National UniversityBusanRepublic of Korea

Early-life stress is associated with a high prevalence of mental illnesses such as post-traumatic stress disorders,attention-deficit/hyperactivity disorder,schizophrenia,and anxiety or depressive behavior,which constitute major public health *** the early stages of brain development after birth,events such as synaptogenesis,neuron maturation,and glial differentiation occur in a highly orchestrated manner,and external stress can cause adverse long-term effects throughout *** body utilizes multifaceted mechanisms,including neuroendocrine and neurotransmitter signaling pathways,to appropriately process external *** individuals first exposed to early-life stress deploy neurogenesis as a stress-defense mechanism;however,in adulthood,early-life stress induces apoptosis of mature neurons,activation of immune responses,and reduction of neurotrophic factors,leading to anxiety,depression,and cognitive and memory *** process involves the hypothalamus-pituitary-adrenal axis and neurotransmitters secreted by the central nervous system,including norepinephrine,dopamine,and *** rodent early-life stress model is generally used to experimentally assess the effects of stress during *** paper reviews the use of the early-life stress model and stress response mechanisms of the body and discusses the experimental results regarding how early-life stress mediates stress-related pathways at a high vulnerability of psychiatric disorder in adulthood.

关键词： early-life stress hypothalamic-pituitary-adrenergic axis maternal separation mental illness neurodevelopmental disorder neuroendocrine system neurotransmitter

Empirical Wavelet Transform Based Method for Identification and Analysis of Sub-synchronous Oscillation Modes Using PMU Data

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 34-40页

作者： Joice G.Philip Jaesung jung Ahmet Onen the Department of Energy Systems Research Ajou UniversitySuwonSouth Korea the Department of Electrical and Electronic Engineering Abdullah Gul UniversityKayseri38080Turkey the Department of Electrical and Computer Engineering College of EngineeringSultan Qaboos UniversityAl-KhoudMuscatOman

This paper proposes an empirical wavelet transform(EWT)based method for identification and analysis of sub-synchronous oscillation(SSO)modes in the power system using phasor measurement unit(PMU)*** phasors from PMUs are preprocessed to check for the presence of *** the presence is established,the signal is decomposed using EWT and the parameters of the mono-components are estimated through Yoshida *** superiority of the proposed method is tested using test signals with known parameters and simulated using actual SSO signals from the Hami Power Grid in Northwest *** show the effectiveness of the proposed EWT-Yoshida method in detecting the SSO and estimating its parameters.

关键词： Empirical wavelet transform(EWT) sub-synchronous oscillation Prony-based method Yoshida algorithm variational mode decomposition phasor measurement unit(PMU)

Application of Thermodynamic Database to Corrosion of ZrO_(2) Containing Submerged Entry Nozzle in Steel Continuous Casting Process

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China's Refractories 2024年第2期33卷 10-15页

作者： In-Ho jung Department of Materials Science and Engineering Seoul National UniversitySeoul 08826South Korea Research Institute of Advanced Materials Seoul National UniversitySeoul 08826South Korea

The CALPHAD thermodynamic databases are very useful to analyze the complex chemical reactions happening in high temperature material *** FactSage thermodynamic database can be used to calculate complex phase diagrams and equilibrium phases involving refractories in industrial *** this study,the FactSage thermodynamic database relevant to ZrO_(2)-based refractories was reviewed and the application of the database to understanding the corrosion of continuous casting nozzle refractories in steelmaking was presented.

关键词： thermodynamic database ZrO_(2)containing submerged entry nozzle continous casting

Disordered Structure and Reversible Phase Transformation from K-Birnessite to Zn-Buserite Enable High-Performance Aqueous Zinc-lon Batteries

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Energy & Environmental Materials 2024年第3期7卷 100-111页

作者： Nibagani Naresh Suyoon Eom Sang Jun Lee Su Hwan Jeong Ji-Won jung Young Hwa jung Joo-Hyung Kim Department of Materials Engineering and Convergence Technology Gyeongsang National University(GNU)Jinju 52828South Korea School of Material Science and Engineering(Ceramic Engineering) Gyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering University of Ulsan(UOU)Ulsan 44776South Korea PLS-ⅡBeamline Division Pohang Accelerator Laboratory(PAL)Pohang 37673South Korea

The layeredδ-MnO_(2)(dMO)is an excellent cathode material for rechargeable aqueous zinc-ion batteries owing to its large interlayer distance(~0.7 nm),high capacity,and low cost;however,such cathodes suffer from structural degradation during the long-term cycling process,leading to capacity *** this study,a Co-doped dMO composite with reduced graphene oxide(GC-dMO)is developed using a simple cost-effective hydrothermal *** degree of disorderness increases owing to the hetero-atom doping and graphene oxide *** is demonstrated that layered dMO and GC-dMO undergo a structural transition from K-birnessite to the Zn-buserite phase upon the first discharge,which enhances the intercalation of Zn^(2+)ions,H_(2)O molecules in the layered *** GC-dMO cathode exhibits an excellent capacity of 302 mAh g^(-1)at a current density of 100 mAg^(-1)after 100 cycles as compared with the dMO cathode(159 mAhg^(-1)).The excellent electrochemical performance of the GC-dMO cathode owing to Co-doping and graphene oxide sheets enhances the interlayer gap and disorderness,and maintains structural stability,which facilitates the easy reverse intercalation and de-intercalation of Zn^(2+)ions and H_(2)O ***,GC-dMO is a promising cathode material for large-scale aqueous ZIBs.

关键词： aqueous zinc-ion batteries birnessite buserite disordered structure phase transformation