• Title/Summary/Keyword: multimodal structures

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Seismic design of irregular space steel frames using advanced methods of analysis

  • Vasilopoulos, A.A.;Bazeos, N.;Beskos, D.E.
    • Steel and Composite Structures
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    • v.8 no.1
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    • pp.53-83
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    • 2008
  • A rational and efficient seismic design methodology for irregular space steel frames using advanced methods of analysis in the framework of Eurocodes 8 and 3 is presented. This design methodology employs an advanced static or dynamic finite element method of analysis that takes into account geometrical and material non-linearities and member and frame imperfections. The inelastic static analysis (pushover) is employed with multimodal load along the height of the building combining the first few modes. The inelastic dynamic method in the time domain is employed with accelerograms taken from real earthquakes scaled so as to be compatible with the elastic design spectrum of Eurocode 8. The design procedure starts with assumed member sections, continues with the checking of the damage and ultimate limit states requirements, the serviceability requirements and ends with the adjustment of member sizes. Thus it can sufficiently capture the limit states of displacements, rotations, strength, stability and damage of the structure and its individual members so that separate member capacity checks through the interaction equations of Eurocode 3 or the usage of the conservative and crude q-factor suggested in Eurocode 8 are not required. Two numerical examples dealing with the seismic design of irregular space steel moment resisting frames are presented to illustrate the proposed method and demonstrate its advantages. The first considers a seven storey geometrically regular frame with in-plan eccentricities, while the second a six storey frame with a setback.

Synthesis of Core-Shell Silica Nanoparticles with Hierarchically Bimodal Pore Structures

  • Yun, Seok-Bon;Park, Dae-Geun;Yun, Wan-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.467-467
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    • 2011
  • Reflecting the growing importance of nanomaterials in science and technology, controlling the porosity combined with well-defined structural properties has been an ever-demanding pursuit in the related fields of frontier researches. A number of reports have focused on the synthesis of various nanoporous materials so far and, recently, the nanomaterials with multimodal porosity are getting an emerging importance due to their improved material properties compared with the mono porous materials. However, most of those materials are obtained in bulk phases while the spherical nanoparticles are one of the most practical platforms in a great number of applications. Here, we report on the synthesis of the core-shell silica nanoparticles with double mesoporous shells (DMSs). The DMS nsnoparticles are spherical and monodispersive and have two different mesoporous shells, i.e., the bimodal porosity. It is the first example of the core-shell silica nanoparticles with the different mesopores coexisting in the individual nanoparticles. Furthermore, the carbon and silica hollow capsules were also fabricated via a serial replication process.

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Multimode pushover analysis based on energy-equivalent SDOF systems

  • Manoukas, Grigorios E.;Athanatopoulou, Asimina M.;Avramidis, Ioannis E.
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.531-546
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    • 2014
  • In this paper the extension of a recently established energy-based pushover procedure in order to include the higher mode contributions to the seismic response of structures is presented and preliminary evaluated. The steps of the proposed methodology in its new formulation are quite similar to those of the well-known Modal Pushover Analysis. However, the determination of the properties of the 'modal' equivalent single-degree-of-freedom systems is achieved by a rationally founded energy-based concept. Firstly, the theoretical background and the assumptions of the proposed methodology are presented and briefly discussed. Secondly, the sequence of steps to be followed for its implementation along with the necessary equations is systematically presented. The accuracy of the methodology is evaluated by an extensive parametric study which shows that, in general, it provides better results compared to those produced by other similar procedures. In addition, the main shortcoming of the initial version of the methodology now seems to be mitigated to a large extent.

Seismic damage assessment of a large concrete gravity dam

  • Lounis Guechari;Abdelghani Seghir;Ouassila Kada;Abdelhamid Becheur
    • Earthquakes and Structures
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    • v.25 no.2
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    • pp.125-134
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    • 2023
  • In the present work, a new global damage index is proposed for the seismic performance and failure analysis of concrete gravity dams. Unlike the existing indices of concrete structures, this index doesn't need scaling with an ultimate or an upper value. For this purpose, the Beni-Haroun dam in north-eastern Algeria, is considered as a case study, for which an average seismic capacity curve is first evaluated by performing several incremental dynamic analyses. The seismic performance point of the dam is then determined using the N2 method, considering multiple modes and taking into account the stiffness degradation. The seismic demand is obtained from the design spectrum of the Algerian seismic regulations. A series of recorded and artificial accelerograms are used as dynamic loads to evaluate the nonlinear responses of the dam. The nonlinear behaviour of the concrete mass is modelled by using continuum damage mechanics, where material damage is represented by a scalar field damage variable. This modelling, which is suitable for cyclic loading, uses only a single damage parameter to describe the stiffness degradation of the concrete. The hydrodynamic and the sediment pressures are included in the analyses. The obtained results show that the proposed damage index faithfully describes the successive brittle failures of the dam which increase with increasing applied ground accelerations. It is found that minor damage can occur for ground accelerations less than 0.3 g, and complete failure can be caused by accelerations greater than 0.45 g.

Research on Effective Use of A Serious Bio-Game (기능성 Bio-Game의 활용 방안에 관한 연구)

  • Park, Sung-Jun;Lee, Jun;Kim, Jee-In
    • Journal of Korea Game Society
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    • v.9 no.1
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    • pp.93-103
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    • 2009
  • A Serious Game helps the learners to recognize the problems effectively, grasp and classify important information needed to solve the problems and convey the contents of what they have learned. Owing not only to this game-like fun but also to the educational effect, The Serious Game can be usefully applied to education and training in the areas of scientific technology and industrial technology. This study proposes the Serious Game that users can apply to biotechnology by using intuitive multi-modal interfaces. In this study, a stereoscopic monitor is used to make three dimensional molecular structures, and multi-modal interface is used to efficiently control. Based on a such system, this study easily solved the docking simulation function, which is one of the important experiments, by applying these game factors. For this, we suggested the level-up concept as a game factor that depends on numbers of objects and users. The proposed system was evaluated in performance comparison in result time of a new drug design process on AIDS virus with previous approach.

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Structural health monitoring of high-speed railway tracks using diffuse ultrasonic wave-based condition contrast: theory and validation

  • Wang, Kai;Cao, Wuxiong;Su, Zhongqing;Wang, Pengxiang;Zhang, Xiongjie;Chen, Lijun;Guan, Ruiqi;Lu, Ye
    • Smart Structures and Systems
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    • v.26 no.2
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    • pp.227-239
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    • 2020
  • Despite proven effectiveness and accuracy in laboratories, the existing damage assessment based on guided ultrasonic waves (GUWs) or acoustic emission (AE) confronts challenges when extended to real-world structural health monitoring (SHM) for railway tracks. Central to the concerns are the extremely complex signal appearance due to highly dispersive and multimodal wave features, restriction on transducer installations, and severe contaminations of ambient noise. It remains a critical yet unsolved problem along with recent attempts to implement SHM in bourgeoning high-speed railway (HSR). By leveraging authors' continued endeavours, an SHM framework, based on actively generated diffuse ultrasonic waves (DUWs) and a benchmark-free condition contrast algorithm, has been developed and deployed via an all-in-one SHM system. Miniaturized lead zirconate titanate (PZT) wafers are utilized to generate and acquire DUWs in long-range railway tracks. Fatigue cracks in the tracks show unique contact behaviours under different conditions of external loads and further disturb DUW propagation. By contrast DUW propagation traits, fatigue cracks in railway tracks can be characterised quantitatively and the holistic health status of the tracks can be evaluated in a real-time manner. Compared with GUW- or AE-based methods, the DUW-driven inspection philosophy exhibits immunity to ambient noise and measurement uncertainty, less dependence on baseline signals, use of significantly reduced number of transducers, and high robustness in atrocious engineering conditions. Conformance tests are performed on HSR tracks, in which the evolution of fatigue damage is monitored continuously and quantitatively, demonstrating effectiveness, adaptability, reliability and robustness of DUW-driven SHM towards HSR applications.

Statistical analysis and probabilistic modeling of WIM monitoring data of an instrumented arch bridge

  • Ye, X.W.;Su, Y.H.;Xi, P.S.;Chen, B.;Han, J.P.
    • Smart Structures and Systems
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    • v.17 no.6
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    • pp.1087-1105
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    • 2016
  • Traffic load and volume is one of the most important physical quantities for bridge safety evaluation and maintenance strategies formulation. This paper aims to conduct the statistical analysis of traffic volume information and the multimodal modeling of gross vehicle weight (GVW) based on the monitoring data obtained from the weigh-in-motion (WIM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. A genetic algorithm (GA)-based mixture parameter estimation approach is developed for derivation of the unknown mixture parameters in mixed distribution models. The statistical analysis of one-year WIM data is firstly performed according to the vehicle type, single axle weight, and GVW. The probability density function (PDF) and cumulative distribution function (CDF) of the GVW data of selected vehicle types are then formulated by use of three kinds of finite mixed distributions (normal, lognormal and Weibull). The mixture parameters are determined by use of the proposed GA-based method. The results indicate that the stochastic properties of the GVW data acquired from the field-instrumented WIM sensors are effectively characterized by the method of finite mixture distributions in conjunction with the proposed GA-based mixture parameter identification algorithm. Moreover, it is revealed that the Weibull mixture distribution is relatively superior in modeling of the WIM data on the basis of the calculated Akaike's information criterion (AIC) values.

Current Status and Direction of Generative Large Language Model Applications in Medicine - Focusing on East Asian Medicine - (생성형 거대언어모델의 의학 적용 현황과 방향 - 동아시아 의학을 중심으로 -)

  • Bongsu Kang;SangYeon Lee;Hyojin Bae;Chang-Eop Kim
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.38 no.2
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    • pp.49-58
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    • 2024
  • The rapid advancement of generative large language models has revolutionized various real-life domains, emphasizing the importance of exploring their applications in healthcare. This study aims to examine how generative large language models are implemented in the medical domain, with the specific objective of searching for the possibility and potential of integration between generative large language models and East Asian medicine. Through a comprehensive current state analysis, we identified limitations in the deployment of generative large language models within East Asian medicine and proposed directions for future research. Our findings highlight the essential need for accumulating and generating structured data to improve the capabilities of generative large language models in East Asian medicine. Additionally, we tackle the issue of hallucination and the necessity for a robust model evaluation framework. Despite these challenges, the application of generative large language models in East Asian medicine has demonstrated promising results. Techniques such as model augmentation, multimodal structures, and knowledge distillation have the potential to significantly enhance accuracy, efficiency, and accessibility. In conclusion, we expect generative large language models to play a pivotal role in facilitating precise diagnostics, personalized treatment in clinical fields, and fostering innovation in education and research within East Asian medicine.

A study on the AVI/AEI International standardization and development of the Korea standard (AVI/AEI 국제표준 동향과 국내표준 개발에 관한 연구)

  • Kim Woong-Yi;Kang Kyung-Woo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.2 no.1 s.2
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    • pp.1-13
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    • 2003
  • This International Standard establishes an AVI/AEI System based on radio frequency technologies. This system is intended for general application in ITS. Specially, It allows the transfer of the identification codes and further information about equipment and vehicles used in intermodal transport into such CVO and information systems related to Intermodal Transport processes. The aim of this standard is to define, describe and specify Architecture, System Parameters, Numbering/ Data structures and interface related to an AVI/AEI system to provide an enabling Standard, which, whilst allowing the system specifier to determine the performance levels and operating conditions, provides a framework for nominal interoperability. The Standard is to establish a common framework to achieve unambiguous identification in AVI/AEI applications. Thes is AVI/AEI is designed to be an 'enabling' structure to allow interoperability between different commercial systems, and not prescriptive in determining any one system. The ISO TC204 WG4 has eight active work items. A new WI on ERI is progressing quickly; three WIs for the road environment and four multimodal WIs are under development. All Work Items are joint between CEN TC278 and ISO TC204 according to the Vienna Agreement, with CEN in the lead. The work is progressing with some delay. For all the work items, the countries who have appointed experts we: Australia, Austria, Belgium, Canada, Czech, Denmark France, Germany, Japan, Korea, the Netherlands, Norway, Spain, Sweden, UK and USA. There are 30 registered experts. The study focus on the AVI/AEcl standardization and developing of the Korea standard

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A Bio-Edutainment System to Virus-Vaccine Discovery based on Collaborative Molecular in Real-Time with VR

  • Park, Sung-Jun
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.6
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    • pp.109-117
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    • 2020
  • An edutainment system aims to help learners to recognize problems effectively, grasp and classify important information needed to solve the problems and convey the contents of what they have learned. Edutainment contents can be usefully applied to education and training in the both scientific and industrial areas. Our present work proposes an edutainment system that can be applied to a drug discovery process including virtual screening by using intuitive multi-modal interfaces. In this system, a stereoscopic monitor is used to make three-dimensional (3D) macro-molecular images, with supporting multi-modal interfaces to manipulate 3D models of molecular structures effectively. In this paper, our system can easily solve a docking simulation function, which is one of important virtual drug screening methods, by applying gaming factors. The level-up concept is implemented to realize a bio-game approach, in which the gaming factor depends on number of objects and users. The quality of the proposed system is evaluated with performance comparison in terms of a finishing time of a drug docking process to screen new inhibitors against target proteins of human immunodeficiency virus (HIV) in an e-drug discovery process.