• Title/Summary/Keyword: structural inference

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A Study of Pre-trained Language Models for Korean Language Generation (한국어 자연어생성에 적합한 사전훈련 언어모델 특성 연구)

  • Song, Minchae;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.28 no.4
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    • pp.309-328
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    • 2022
  • This study empirically analyzed a Korean pre-trained language models (PLMs) designed for natural language generation. The performance of two PLMs - BART and GPT - at the task of abstractive text summarization was compared. To investigate how performance depends on the characteristics of the inference data, ten different document types, containing six types of informational content and creation content, were considered. It was found that BART (which can both generate and understand natural language) performed better than GPT (which can only generate). Upon more detailed examination of the effect of inference data characteristics, the performance of GPT was found to be proportional to the length of the input text. However, even for the longest documents (with optimal GPT performance), BART still out-performed GPT, suggesting that the greatest influence on downstream performance is not the size of the training data or PLMs parameters but the structural suitability of the PLMs for the applied downstream task. The performance of different PLMs was also compared through analyzing parts of speech (POS) shares. BART's performance was inversely related to the proportion of prefixes, adjectives, adverbs and verbs but positively related to that of nouns. This result emphasizes the importance of taking the inference data's characteristics into account when fine-tuning a PLMs for its intended downstream task.

Operational modal analysis of Canton Tower by a fast frequency domain Bayesian method

  • Zhang, Feng-Liang;Ni, Yi-Qing;Ni, Yan-Chun;Wang, You-Wu
    • Smart Structures and Systems
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    • v.17 no.2
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    • pp.209-230
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    • 2016
  • The Canton Tower is a high-rise slender structure with a height of 610 m. A structural health monitoring system has been instrumented on the structure, by which data is continuously monitored. This paper presents an investigation on the identified modal properties of the Canton Tower using ambient vibration data collected during a whole day (24 hours). A recently developed Fast Bayesian FFT method is utilized for operational modal analysis on the basis of the measured acceleration data. The approach views modal identification as an inference problem where probability is used as a measure for the relative plausibility of outcomes given a model of the structure and measured data. Focusing on the first several modes, the modal properties of this supertall slender structure are identified on non-overlapping time windows during the whole day under normal wind speed. With the identified modal parameters and the associated posterior uncertainty, the distribution of the modal parameters in the future is predicted and assessed. By defining the modal root-mean-square value in terms of the power spectral density of modal force identified, the identified natural frequencies and damping ratios versus the vibration amplitude are investigated with the associated posterior uncertainty considered. Meanwhile, the correlations between modal parameters and temperature, modal parameters and wind speed are studied. For comparison purpose, the frequency domain decomposition (FDD) method is also utilized to identify the modal parameters. The identified results obtained by the Bayesian method, the FDD method and a finite element model are compared and discussed.

An evolutionary fuzzy modelling approach and comparison of different methods for shear strength prediction of high-strength concrete beams without stirrups

  • Mohammadhassani, Mohammad;Nezamabadi-pour, Hossein;Suhatril, Meldi;shariati, Mahdi
    • Smart Structures and Systems
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    • v.14 no.5
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    • pp.785-809
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    • 2014
  • In this paper, an Adaptive nerou-based inference system (ANFIS) is being used for the prediction of shear strength of high strength concrete (HSC) beams without stirrups. The input parameters comprise of tensile reinforcement ratio, concrete compressive strength and shear span to depth ratio. Additionally, 122 experimental datasets were extracted from the literature review on the HSC beams with some comparable cross sectional dimensions and loading conditions. A comparative analysis has been carried out on the predicted shear strength of HSC beams without stirrups via the ANFIS method with those from the CEB-FIP Model Code (1990), AASHTO LRFD 1994 and CSA A23.3 - 94 codes of design. The shear strength prediction with ANFIS is discovered to be superior to CEB-FIP Model Code (1990), AASHTO LRFD 1994 and CSA A23.3 - 94. The predictions obtained from the ANFIS are harmonious with the test results not accounting for the shear span to depth ratio, tensile reinforcement ratio and concrete compressive strength; the data of the average, variance, correlation coefficient and coefficient of variation (CV) of the ratio between the shear strength predicted using the ANFIS method and the real shear strength are 0.995, 0.014, 0.969 and 11.97%, respectively. Taking a look at the CV index, the shear strength prediction shows better in nonlinear iterations such as the ANFIS for shear strength prediction of HSC beams without stirrups.

Control of Smart Base-isolated Benchmark Building using Fuzzy Supervisory Control (퍼지관리제어기법을 이용한 스마트 면진 벤치마크 건물의 제어)

  • Kim, Hyun-Su;Roschke P. N.
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.4 s.44
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    • pp.55-66
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    • 2005
  • The effectiveness of fuzzy supervisory control technique for the control of seismic responses of smart base isolation system is investigated in this study. To this end, first generation base isolated building benchmark problem is employed for the numerical simulation. The benchmark structure under consideration is an eight-story base isolated building having irregular plan and is equipped with low-damping elastometric bearings and magnetorheological (MR) dampers for seismic protection. Lower level fuzzy logic controllers (FLC) for far-fault or near-fault earthquakes are developed in order to effectively control base isolated building using multi-objective genetic algorithm. Four objectives, i.e. reduction of peak structural acceleration, peak base drift, RMS structural acceleration and RMS base drift, are used in multi-objective optimization process. When earthquakes are applied to benchmark building, each of low level FLCs provides different command voltage and supervisory fuzzy controller combines two command voltages io one based on fuzzy inference system in real time. Results from the numerical simulations demonstrate that base drift as well as superstructure responses can be effectively reduced using the proposed supervisory fuzzy control technique.

An Exploratory Study on the Structural Relationship of Brand Equity, Internal Brand, Conflict and Relationship Dissolution on Franchise System (프랜차이즈 시스템에서 브랜드 자산, 내부브랜드 활동, 갈등 및 관계해지의 구조적 관계에 관한 탐색적 연구)

  • Kim, Kyung-Min;Na, June-Hee;Lee, Young-Chan
    • Journal of Distribution Research
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    • v.12 no.1
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    • pp.65-84
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    • 2007
  • The relation between franchiser and franchisee participated the franchise system was studied focused on brand for the correlation of relationship dissolution. Basically the relation among brand equity, internal brand, conflict and relationship dissolution based on brand on franchise system were investigated. The study of external factor and internal one of brand recognized by franchisee was conducted. The questionnaire was carried out for franchisee participated of national franchise system. The results showed that the brand external factor of brand transaction cost, brand equity and brand communication had influence on brand dissolution by the affection of brand identification and conflict classified as brand internal factor. In addition, brand internal reinforcement factor affected brand dissolution also. The structural causal inference between internal factor and external one was examined. Finally, the theoretical and managerial insight were suggested on the brand role for the consecutive relation as well as the limit of the study and future suggestion were included.

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Geological Structural Lines and Hamdeok-Pyoseon Graben in Jeju Island (제주도의 지질구조선과 함덕-표선 지구대)

  • Booh Seong-An;Jeong Gyo-Cheol;Kim Hye-Bin;Kim Kyeong-Su;Woo Myoung-Ha;Lee Byoung-Ho
    • The Journal of Engineering Geology
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    • v.15 no.4 s.42
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    • pp.475-486
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    • 2005
  • According to the inference results of formation process of the tectonic lineament, totally four events of subsidence including two events after upheaval of granite body and two events after sedimentation of unconsolidated sedimentary layer formed the macroscopic tensional lineament. The subsidence was occurred by tensional stress oriented ENE-WSW direction and compressional stress oriented NNW-SSE direction. The deeper distribution of tuff and unconsolidated sedimentary layer as much as 70-140m and that of granite as much as 50-500m at Hamdeok and Shinheung than those of the eastern and the western area around Hamdeok and Shinheong is due to the Hamdeok-Pyoseon Graben by three events of differential subsidence from Hamdeok to Pyoseon including Shinheung.

Knowledge-based Expert System for the Preliminary Ship Structural Design (선체 구조설계를 위한 지식 베이스 전문가 시스템)

  • Y.S. Yang;Y.S. Yeon
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.1
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    • pp.1-13
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    • 1992
  • The objective of this study is to develop knowledge-based system for the preliminary design and midship section design of bulk carrier and to enhance the applicability of knowledge engineering in the field of Naval Architecture. First, expert system shell called E.1 is developed in C language. E.1 supports backward-chaining, automatic iteration procedure and reiterative inference mechanism for efficient application of knowledge-based system in structural design. Knowledge representation in E.1 includes IF-THEN rules, 'facts'and 'tables'. Second, knowledge bases for the principal particulars and midship section design are developed by experimental formula, design standard and experiential knowlege. Third, hybrid system combined this knowledge-based system with the optimization program of midship section is developed. Finally, the simplified design method utilizing the regression analysis of the optimum results of stiffened plate is developed for facilitating the design process. Using this knowledge-based system, the design process and results for Bulk carrier and stiffened plates are discussed. It is concluded that knowledge-based system is efficient for preliminary design and midship section design of the ship. It is expected that the performance of the CAD system would be enhanced if the better knowledge-base is accumulated in the E.1 tool.

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Integrity Assessment for Reinforced Concrete Structures Using Fuzzy Decision Making (퍼지의사결정을 이용한 RC구조물의 건전성평가)

  • 손용우;정영채;김종길
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.2
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    • pp.131-140
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    • 2004
  • It really needs fuzzy decision making of integrity assessment considering about both durability and load carrying capacity for maintenance and administration, such as repairing and reinforcing. This thesis shows efficient models about reinforced concrete structure using CART-ANFIS. It compares and analyzes decision trees parts of expert system, using the theory of fuzzy, and applying damage & diagnosis at reinforced concrete structure and decision trees of integrity assessment using established artificial neural. Decided the theory of reinforcement design for recovery of durability at damaged concrete & the theory of reinforcement design for increasing load carrying capacity keep stability of damage and detection. It is more efficient maintenance and administration at reinforced concrete for using integrity assessment model of this study and can carry out predicting cost of life cycle.

Experimental Validation of Crack Growth Prognosis under Variable Amplitude Loads (변동진폭하중 하에서 균열성장 예측의 실험적 검증)

  • Leem, Sang-Hyuck;An, Dawn;Lim, Che-Kyu;Hwang, Woongki;Choi, Joo-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.3
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    • pp.267-275
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    • 2012
  • In this study, crack growth in a center-cracked plate is predicted under mode I variable amplitude loading, and the result is validated by experiment. Huang's model is employed to describe crack growth with acceleration and retardation due to the variable loading effect. Experiment is conducted with Al6016-T6 plate, in which the load is applied, and crack length is measured periodically. Particle Filter algorithm, which is based on the Bayesian approach, is used to estimate model parameters from the experimental data, and predict the crack growth of the future in the probabilistic way. The prediction is validated by the run-to-failure results, from which it is observed that the method predicts well the unique behavior of crack retardation and the more data are used, the closer prediction we get to the actual run-to-failure data.

Target-free vision-based approach for vibration measurement and damage identification of truss bridges

  • Dong Tan;Zhenghao Ding;Jun Li;Hong Hao
    • Smart Structures and Systems
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    • v.31 no.4
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    • pp.421-436
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    • 2023
  • This paper presents a vibration displacement measurement and damage identification method for a space truss structure from its vibration videos. Features from Accelerated Segment Test (FAST) algorithm is combined with adaptive threshold strategy to detect the feature points of high quality within the Region of Interest (ROI), around each node of the truss structure. Then these points are tracked by Kanade-Lucas-Tomasi (KLT) algorithm along the video frame sequences to obtain the vibration displacement time histories. For some cases with the image plane not parallel to the truss structural plane, the scale factors cannot be applied directly. Therefore, these videos are processed with homography transformation. After scale factor adaptation, tracking results are expressed in physical units and compared with ground truth data. The main operational frequencies and the corresponding mode shapes are identified by using Subspace Stochastic Identification (SSI) from the obtained vibration displacement responses and compared with ground truth data. Structural damages are quantified by elemental stiffness reductions. A Bayesian inference-based objective function is constructed based on natural frequencies to identify the damage by model updating. The Success-History based Adaptive Differential Evolution with Linear Population Size Reduction (L-SHADE) is applied to minimise the objective function by tuning the damage parameter of each element. The locations and severities of damage in each case are then identified. The accuracy and effectiveness are verified by comparison of the identified results with the ground truth data.