• 한국공작기계학회논문집
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• 제10권4호
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• pp.104-110
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• 2001

The objective of this study is structural analysis of continuous casting mold. A two-dimensional finite element model was developed to compute the temperature distribution, thermal stress and thermal strain behavior for continuous casting mold. Structural analysis was made using thermal analysis result, utilizing transient analysis of ANSYS. This structural analysis results, many variables such as casting speed, cooling condition film coefficient, convection and load condition are considered.

• Structural Engineering and Mechanics
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• 제33권2호
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• pp.179-191
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• 2009

This paper is aimed at combining wavelet multiresolution analysis and nonstationary Kanai-Tajimi model for the simulation of earthquake accelerograms. The proposed approach decomposes earthquake accelerograms using wavelet multiresolution analysis for the simulation of earthquake accelerograms. This study is on the basis of some Iranian earthquake records, namely Naghan 1977, Tabas 1978, Manjil 1990 and Bam 2003. The obtained results indicate that the simulated records preserve the significant properties of the actual accelerograms. In order to investigate the efficiency of the model, the spectral response curves obtained from the simulated accelerograms have been compared with those from the actual records. The results revealed that there is a good agreement between the response spectra of simulated and actual records.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.37-43
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• 2007

Recent technological developments in machine tools have been focused on high speed, low vibration machining and high precision machining. And the concern with multi-functional machining has been increased for the last several years. Multi-tasking machines are widely used in machine tool industries. Laser multi-tasking machine has been developed for high precision and fewer vibration machining. The purpose of this study is to evaluate the effects of structural reinforcement on Laser multi-tasking machine which is comprehensively combined turning center and laser machine. Up to date, for the structural stability evaluation of a multi-tasking machine, the analysis model has been considered only the weight of the upper parts. The positions of upper parts on multi-tasking machine have not been considered in the model. So, the results of the present FE model have revealed some difference with measurement data in case of multi-tasking machine. Design of the machine and structural analysis is carried out by FEM simulation using the commercial software CATIA V5. In the result of the structural analysis, effectiveness of reinforcement of the bed was confirmed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 춘계학술발표회 논문집
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• pp.120-127
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• 1998

It is very difficult to execute the vibration analysis of a huge strucutre, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.. The following can be found from this study. 1. The analytical results are generally coincident with each other. 2. The equivalent system of the superstructure model can be easily obtained using the sensitivity analysis metho and the optimum structural modification method. 3. The structural modification using the equivalent system can be obtained good results above 90% of object value.

• 대한원격탐사학회지
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• 제39권5_1호
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• pp.621-635
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• 2023

시설물 상태평가는 시설물의 사용성을 평가하고, 진단 주기를 결정하는 중요한 과정이다. 현재 수행되고 있는 인력 기반 방법은 안전, 효율, 객관성에 대한 문제를 안고 있어 이를 개선하기 위해 영상을 이용한 딥러닝(deep learning) 기반의 연구가 수행되고 있다. 그러나 시설물 손상 데이터는 발견하기 어려워 다량의 시설물 손상 학습 데이터를 구축하기 어렵고, 이는 딥러닝 기반 상태평가에 한계로 작용한다. 본 연구에서는 영상 기반 시설물 상태평가의 학습 데이터 부족으로 인한 어려움을 개선하기 위해 파운데이션 모델(foundation model) 기반 2-step 시설물 손상 분석을 제시한다. 시설물 상태평가의 요소를 객체화와 정량화로 세분화하고, 정량화 단계에서 영상 분할(segmentation) 파운데이션 모델을 적용하였다. 본 연구의 방법은 기존 영상 분할 방법 대비 10% 포인트 이상 높은 mean intersection over union을 나타냈고, 특히 철근 노출의 경우에는 40% 포인트 이상의 성능 개선을 보였다. 본 연구의 방법이 학습 데이터 구축이 어려운 도메인에 성능 개선을 가져올 것이라 기대한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.265-268
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• 2008

With application of IT convergence technique in AEC industry, it is currently conducted the research on the virtual construction system. This paper aims at the pilot study on the structural design based on BIM used in collaboration environment. The work scope of structural design includes the structural analysis model, structural detail model and analytic model and we focuse the research on the interoperability among them. It is partly utilized the transfer module supplied by software developer and partly developed here the interface module through API. This paper shows the interoperability process to pilot test and indicates the problems occurred in interface.

• Nutrition Research and Practice
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• 제8권4호
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• pp.432-438
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• 2014

BACKGROUND/OBJECTIVES: This research was conducted to develop a construct model regarding the dietary style, late night snacking choice attributes and health promotion behaviors of industrial workers. SUBJECTS/METHODS: The surveys were collected during the period between January and February 2013. A statistical analysis of 888 industrial workers was conducted using SPSS 12.0 for Windows and SEM (Structural Equation Model) using AMOS (Analysis of Moment Structure) 5.0 statistics package. RESULTS: The results of the correlations between all variables showed significant positive correlations (P < 0.05). Results of factors analysis on dietary styles were categorized into five factors and health promotion behaviors were categorized into four. The reliability of these findings was supported by a Cronbach's alpha coefficient of 0.6 and higher for all other factors. After obtaining the factors from processing an exploratory factor analysis and the end results supported the validity. In an attempt to study the late night snacking choice attributes in accordance to dietary styles and the health promotion behaviors of industrial workers, a structural equation model was constructed and analyzed. CONCLUSIONS: All tests proved the model satisfied the recommended levels of the goodness on fit index, and thus, the overall research model was proved to be appropriate.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.210-215
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• 1998

To design a space frame structure by the conventional method is not easy in practical sense since it is generally a three-dimensional complicated form, and stability and nonlinear problems are not easily checked in the design process. This paper describes two modules, the Model Generator which is based on PATRAN user interface that enables users to generate a complicated finite element model; the Optimum Design Module which analyzes output results of analysis program, and designs members of a space frame. The Model Generator is based on PCL while C++ language is used in the Optimum Design Module. Structural analysis is performed by using ABAQUS. All of these modules constitute Space Frame Integrated Design System. The Core of the system is PATRAN database, in which the Model Generator creates information of a finite element model. Then, PATRAN creates input files needed for the analysis program from the information of the finite element model in the database, and in turn, imports output results of analysis program to the database. Finally, the Optimum Design Module processes member grouping of a space frame based on the output results, and performs optimal member selection of a space frame. This process is repeated until the desired optimum structural members are obtained.

• Computers and Concrete
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• 제33권3호
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• pp.285-299
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• 2024

Recently, many engineering computations have realized their digital transformation to Machine Learning (ML)-based systems. Predicting the behavior of a structure, which is mainly computed with structural analysis software, is an essential step before construction for efficient structural analysis. Especially in the seismic-based design procedure of the structures, predicting the lateral load capacity of reinforced concrete (RC) columns is a vital factor. In this study, a novel ML-based model is proposed to predict the maximum lateral load capacity of RC columns under varying axial loads or cyclic loadings. The proposed model is generated with a Deep Neural Network (DNN) and compared with traditional ML techniques as well as a popular commercial structural analysis software. In the design and test phases of the proposed model, 319 columns with rectangular and square cross-sections are incorporated. In this study, 33 parameters are used to predict the maximum lateral load capacity of each RC column. While some traditional ML techniques perform better prediction than the compared commercial software, the proposed DNN model provides the best prediction results within the analysis. The experimental results reveal the fact that the performance of the proposed DNN model can definitely be used for other engineering purposes as well.

• Structural Monitoring and Maintenance
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• 제10권1호
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• pp.63-86
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• 2023

Structural health monitoring and damage detection are essential for assessing, maintaining, and rehabilitating structures. Most of the existing damage detection approaches compare the current state structural response with the undamaged vibrational structural response, which is unsuitable for old and existing structures where undamaged vibrational responses are absent. One of the approaches for existing structures, numerical model updating/inverse modelling, available in the literature, is limited to numerical studies with high-end software. In this study, an attempt is made to study the effectiveness of the model updating technique, simplify modelling complexity, and economize its usability. The optimization-based detection problem is addressed by using programmable open-sourced code, OpenSees^® and a derivative-free optimization code, NOMAD^®. Modal analysis is used for damage identification of beam-like structures with several damage scenarios. The performance of the proposed methodology is validated both numerically and experimentally. The proposed method performs satisfactorily in identifying both locations and intensity of damage in structures.