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Detecting changes in long-period site responses after the M_w 7.6 Chi-Chi earthquake, Taiwan, using strong motion records

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Earthquake Engineering and Engineering Vibration 2015年第2期14卷 217-228页

作者： Teng-To Yu Chi-shin Wu Youg-Sin Cheng Department of Resources Engineering Cheng Kung University (NCKU)

Temporal changes in site effects are obtained using the HVSR(horizontal-to-vertical spectral ratio) method and strong motion records after the M w 7.6 Chi-Chi earthquake, Taiwan. Seismic data recorded between 1995 and 2010 are used, comprising 3,708 data from 15 stations adjacent to the Chelungpu fault. Temporal fl uctuations are determined by analyzing the site effect variation using a time–frequency variation(TFV) diagram based on these seismic data. Stations adjacent to the fault show signifi cant disturbances in the resonance frequency at 16–26 Hz. Station TCU129 shows a 40% drop in fundamental frequency after the main shock, and a gradual return to the original state over nine years. For stations located farther from the fault zone, sudden changes in tectonic stress play a dominant role in temporal changes to the HVSR. An impact analysis of the directional factor confi rms our fi nding that the proximity of the fault to seismic stations has the most infl uence on data.

关键词： Chi-Chi earthquake horizontal-to-vertical spectral

Constructing confidence intervals of extreme rainfall quantiles using Bayesian,bootstrap,and profile likelihood approaches

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Science China(Technological Sciences) 2016年第4期59卷 573-585页

作者： CHEN Si LI YaXing shin JiYae KIM TaeWoong department of civil and environmental engineering hanyang universitySeoul 133-791Korea department of electronics&communication engineering hanyang universityAnsan 426-791Korea department of civil and environmental engineering hanyang universityAnsan 426-791Korea

Hydrological risk is highly dependent on the occurrence of extreme *** fact has led to a wide range of studies on the estimation and uncertainty analysis of the *** most cases,confidence intervals(CIs)are constructed to represent the uncertainty of the *** the accuracy of CIs depends on the asymptotic normality of the data and is questionable with limited observations in practice,a Bayesian highest posterior density(HPD)interval,bootstrap percentile interval,and profile likelihood(PL)interval have been introduced to analyze the uncertainty that does not depend on the normality ***,comparison studies to investigate their performances in terms of the accuracy and uncertainty of the estimates are *** addition,the strengths,weakness,and conditions necessary for performing each method also must be ***,in this study,test experiments with simulations from varying parent distributions and different sample sizes were ***,applications to the annual maximum rainfall(AMR)time series data in South Korea were *** districts with 38-year(1973–2010)AMR observations were fitted by the three aforementioned methods in the *** both the experimental and application results,the Bayesian method is found to provide the lowest uncertainty of the design level while the PL estimates generally have the highest accuracy but also the largest *** bootstrap estimates are usually inferior to the other two methods,but can perform adequately when the distribution model is not heavy-tailed and the sample size is *** distribution tail behavior and the sample size are clearly found to affect the estimation accuracy and *** study presents a comparative result,which can help researchers make decisions in the context of assessing extreme rainfall uncertainties.

关键词： Bayesian bootstrap profile likelihood confidence interval frequency analysis

Hyperreflective photonic crystals created by shearing colloidal dispersions at ultrahigh volume fraction

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Microsystems & Nanoengineering 2024年第1期10卷 161-173页

作者： Minji Kim Jong Bin Kim shin-Hyun Kim Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea

Colloidal crystallization serves as one of the most economic and scalable production methods for photonic ***,insufficient optical performance,nonuniformity and low reproducibility remain challenges for advanced high-value *** this study,we optimally formulate a photocurable dispersion of silica particles and apply shear flow to unify the orientation of the colloidal crystals,ensuring high optical performance and *** silica particles experience strong repulsion at ultrahigh volume fractions of 50%but demonstrate low mobility,leading to polycrystalline *** shear flow to the dispersions allows the silica particles to rearrange into larger crystalline domains with a unidirectional orientation along the *** shear-induced structural change produces absolute reflectivity at the stopband as high as 90%and a high transparency of 90%at off-resonant wavelengths with minimal diffusive ***,the strong interparticle repulsion ensures a uniform volume fraction of particles throughout the dispersion,reducing deviations in the optical *** intricately micropattern the photocurable dispersions using ***,the photonic films and patterns can be stacked to form multiple layers,displaying mixed structural colors and multiple reflectance peaks without sacrificing *** superior photonic materials hold promise for various optical applications,including optical components and anticounterfeiting patches.

关键词： properties. dispersion reflectivity

Formulation of corrosion rate of magnesium alloys using microstructural parameters

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Journal of Magnesium and Alloys 2020年第1期8卷 134-149页

作者： Ahmad Bahmani Srinivasan Arthanari Kwang Seon shin Magnesium Technology Innovation Center School of Materials Science and EngineeringSeoul National University1 Gwanak-roGwanak-guSeoul 08826Korea

Up to the date of writing this article,a quantitative analysis between corrosion rate and combined microstructural parameters including composition,grain size,and precipitations has not been ***,a literature review was carried out on these parameters to understand the quantitative effect of each one on the corrosion rate of Mg and Mg ***,using the available data in the literature and several experimental results,a new model was developed to predict the corrosion rate,through microstructural *** model suggests that by using ultra-fined grains,alloying compounds with low Volta-potential difference relative to the matrix and a low fraction of secondary phase,a very low corrosion rates of materials are achievable.

关键词： Corrosion rate Magnesium Grain size Volta-potential

Effects of Supercritical Environment on Hydrocarbon-fuel Injection

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Journal of Thermal Science 2017年第2期26卷 183-191页

作者： Bongchul shin Dohun Kim Min Son Jaye Koo Graduate School Korea Aerospace UniversityGoyangRepublic of Korea School of Aerospace and Mechanical Engineering Korea Aerospace UniversityGoyangRepublic of Korea

In this study, the effects of environment conditions on decane were investigated. Decane was injected in subcritical and supercritical ambient conditions. The visualization chamber was pressurized to 1.68 MPa by using nitrogen gas at a temperature of 653 K for subcritical ambient conditions. For supercritical ambient conditions, the visualization chamber was pressurized to 2.52 MPa by using helium at a temperature of 653 K. The decane injection in the pressurized chamber was visualized via a shadowgraph technique and gradient images were obtained by a post processing method. A large variation in density gradient was observed at jet interface in the case of subcritical injection in subcritical ambient conditions. Conversely, for supercritical injection in supercritical ambient conditions, a small density gradient was observed at the jet interface. In a manner similar to that observed in other cases, supercritical injection in subcritical ambient conditions differed from supercritical ambient conditions such as sphere shape liquid. Additionally, there were changes in the interface, and the supercritical injection core width was thicker than that in the subcritical injection. Furthermore, in cases with the same injection conditions, the change in the supercritical ambient normalized core width was smaller than the change in the subcritical ambient normalized core width owing to high specific heat at the supercritical injection and small phase change at the interface. Therefore, the interface was affected by the changing ambient condition. Given that the effect of changing the thermodynamic properties of propellants could be essential for a variable thrust rocket engine, the effects of the ambient conditions were investigated experimentally.

关键词： Decane Jet Subcritical Supercritical Visualization

Few-Shot Graph Classification with Structural-Enhanced Contrastive Learning for Graph Data Copyright Protection

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Tsinghua Science and Technology 2024年第2期29卷 605-616页

作者： Kainan Zhang DongMyung shin Daehee Seo Zhipeng Cai Department of Computer Science Georgia State UniversityAtlantaGA 30303USA LSWare Inc. Seoul 08504Republic of Korea College of Intelligence Information Engineering Sangmyung UniversitySeoul 03016Republic of Korea

Open-source licenses can promote the development of machine learning by allowing others to access,modify,and redistribute the training ***,not all open-source licenses may be appropriate for data sharing,as some may not provide adequate protections for sensitive or personal information such as social network ***,some data may be subject to legal or regulatory restrictions that limit its sharing,regardless of the licensing model ***,obtaining large amounts of labeled data can be difficult,time-consuming,or expensive in many real-world ***-shot graph classification,as one application of meta-learning in supervised graph learning,aims to classify unseen graph types by only using a small amount of labeled ***,the current graph neural network methods lack full usage of graph structures on molecular graphs and social network *** structural features are known to correlate with molecular properties in chemistry,structure information tends to be ignored with sufficient property information ***,the common binary classification task of chemical compounds is unsuitable in the few-shot setting requiring novel ***,this paper focuses on the graph classification tasks of a social network,whose complex topology has an uncertain relationship with its nodes'*** two multi-class graph datasets with large node-attribute dimensions constructed to facilitate the research,we propose a novel learning framework that integrates both meta-learning and contrastive learning to enhance the utilization of graph topological *** experiments demonstrate the competitive performance of our framework respective to other state-of-the-art methods.

关键词： few-shot learning contrastive learning data copyright protection

Holo-imprinting polarization optics with a reflective liquid crystal hologram template

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Light(Science & Applications) 2022年第3期11卷 127-135页

作者： Jianghao Xiong Qian Yang Yannanqi Li shin-Tson Wu College of Optics and Photonics University of Central FloridaOrlandoFL 32816USA

Liquid crystal polarization optics based on photoalignment technique has found pervasive applications in next-generation display platforms like virtual reality and augmented *** large-scale fabrication,however,remains a big challenge due to the high demands in small feature size,fast processing speed,and defects-free alignment quality during the photoalignment process,especially for large-angle reflective *** we propose a new concept of holo-imprinting based on non-contact replication of polarization pattern with a reflective liquid crystal hologram as a *** theoretical analysis and experimental results validate the possibility of generating a high-quality polarization pattern exploiting the self-interfering beams of reflective *** method can be extended to numerous devices,from transmissive to reflective,from small angle to large angle,and from grating,lens,to freeform *** widespread impact on the fabrication of liquid crystal polarization optics for advanced display and imaging systems is foreseeable.

关键词： optics crystal alignment

Enhancement of mechanical and tribological performance of Ti-6Al-4V alloy by laser surface alloying with Inconel 625 and SiC precursor materials

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Friction 2024年第9期12卷 2089-2107页

作者： Hao-Ran CHENG Ki-Hoon shin Hong Seok KIM Department of Mechanical Engineering Graduate School of Seoul National University of Science and TechnologySeoul 01811Republic of Korea Department of Mechanical and Automotive Engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea

This study focused on producing metal matrix composite(MMC)coatings on Ti–6Al–4V alloy through laser surface alloying using a novel combination of Inconel 625 and SiC precursor *** ratios of alloying powders were examined to evaluate surface properties such as microhardness,wear resistance,and friction coefficient,along with analyzing the phase composition and microstructure of the *** in situ synthesized MMC coatings exhibited the presence ofα-Ti,NiTi,NiTi_(2),and TiC ***,Ti_(5)Si_(3)andα-Ti/Ti_(5)Si_(3)eutectic structures were observed when the SiC content exceeded 20%.In comparison to the titanium substrate,the MMC coating significantly enhanced microhardness by over threefold and reduced wear by 95%.However,it was crucial to carefully select the appropriate combination of alloying powders to avoid a substantial decrease in friction performance and excessive formation of *** a comparative analysis of experimental results,the optimal precursor material composition was identified as 85%Inconel 625 and 15%*** study demonstrated the effective utilization of Inconel 625 and SiC alloying materials to enhance the surface properties of titanium alloys,thereby expanding their application in challenging environments.

关键词： titanium alloy Inconel 625 SiC ceramic laser surface alloying metal matrix composite(MMC)

Effects of Kampo medicine hangebyakujutsutemmato on persistent postural-perceptual dizziness:A retrospective pilot study

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World Journal of Clinical Cases 2022年第20期10卷 6811-6824页

作者： Toru Miwa shin-ichi Kanemaru Department of Otolaryngology-Head and Neck Surgery Osaka Metropolitan UniversityOsaka 5458585Japan Department of Otolaryngology-Head and Neck Surgery Tazuke Kofukai Medical Research InstituteKitano HospitalOsaka 5308480Japan Department of Otolaryngology-Head and Neck Surgery Kyoto UniversityKyoto 7507501Japan

BACKGROUND Persistent postural-perceptual dizziness(PPPD)is a functional disorder,typically preceded by acute vestibular *** is characterized by a shift in processing spatial orientation information,to favor visual over vestibular and somatosensory inputs,and a failure of higher cortical *** date,no therapies for PPPD have been *** medicine hangebyakujutsutemmato(HBT)has been reported to alleviate disturbances of *** hypothesized that HBT would be a beneficial treatment for *** To examine the efficacy of HBT for the treatment of *** Patients with PPPD were enrolled and divided into two groups:The HBT group(n=24)and the non-HBT group(n=14).The participants completed questionnaire surveys[Niigata PPPD questionnaire(NPQ),dizziness handicap inventory,hospital anxiety and depression scale(HADS),orthostatic dysregulation questionnaire,pittsburg sleep quality index(PSQI),and motion sickness scores]before and after HBT ***,to identify HBT responders,multivariate regression analysis was performed using the results of the ques-tionnaire surveys and equilibrium tests;including stabilometry,and caloric,vestibular evoked myogenic response,and head-up tilt *** Thirty-eight outpatients were included in this study,of which 14 patients(3 men,11 women;mean age,63.5±15.9 years)received treatment without HBT,and 24(1 man,23 women;mean age,58.2±18.7 years)received combination treatment with *** HBT treatment,NPQ scores decreased significantly(baseline 40.1±10.0 vs 2 mo 24.6±17.7,P<0.001).No statistically significant changes were observed in the NPQ scores in the non-HBT group(baseline 38.6±12.2 vs 2 mo 39.4±14.4,P=0.92).Multivariable regression analysis revealed that the results of stabilometry(P=0.02)and the caloric(P=0.03),and head-up tilt tests(P<0.001),HADS(P=0.003),and PSQI(P=0.01)were associated with HBT responsiveness in PPPD *** HBT may be an effective adjunct therapy fo

关键词： Hangebyakujutsutemmato Kampo medicine Persistent postural-perceptual dizziness Niigata persistent postural-perceptual dizziness questionnaire score Sensory reweighting Treatment responder