• Elastomers and Composites
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• v.39 no.3
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• pp.193-208
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• 2004

Morphology of injection molded polymer blend was investigated by experimental and theoretical approach. In experiments, the effects of injection speed and injection temperature on the morphology of injection molded MPPO/Nylon 6 blend were investigated. The morphology distribution across the part thickness was clearly observed in injection molded blend. We could observe several distinct regions across the thickness of molded part: skin layer, subskin layer and core region. The skin layer where the dispersed phase is fine and highly deformed to the flow direction is observed to be located near the part surface. The subskin layer located at inner region of the skin layer also observed. In the subskin layer, the dispersed phase is coarser than that of skin layer and deforms to the flow direction. Based on the experimental results, the calculation scheme to predict the morphology of injection molded polymer blend was suggested. The morphology of injection molded polymer blend could be predicted in corporation with the result of flow analysis obtained from commercial software for injection molding process and the theory of drop behavior under the flow. The suggested calculation scheme could predict the effect of injection conditions on the morphology of injection molded parts.

• Composites Research
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• v.30 no.5
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• pp.280-287
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• 2017

The complex deformation of the swept composite wing occurs due to the torsional load and bending load during the flight. Therefore, prediction for displacement of swept composite wing is required for structural health monitoring. Wing displacements can be predicted by using relationship between displacements and strains. The strain distributions on the fixed-end are complex due to the geometric shape of the swept wing. Because of those strain distribution, the wing displacement can be diversely predicted by the strain sensing locations. In this paper, displacements prediction of swept composite wing was performed by considering complex strain distributions. The predicted displacements under various loading condition were consistent with those calculated by FEA and verified through the bending test.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.933-936
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• 2008

An engineered cementitious composite (Engineered Cementitious Composite) had been developed in previous study. Theoretical prediction of the tensile stress-strain relation of ECC is important in providing the material constitutive relation necessary for designing structural members. But, few studies have been reported with regard to predicting the tensile stress-strain relation of ECC. Prediction of the tensile stress-strain relation of ECC accounting for actual bridging curve, such as fiber dispersion is needed. The present study extends the work as developed by Kanda et al., by modeling the bridging curve, accounting for fiber dispersion, the degree of matrix spalling, and fiber rupture to predict the tensile stress-strain relation of ECC. The role of material variation in the bridging curve, such as number of effective fiber actually involved in the bridging capacity and how it affects the multiple cracking process is discussed. The approach for formulating the tensile stress-strain relation is discussed next, where the procedure for obtaining the necessary parameters, such as the crack spacing, is presented. Finally, the predicted stress-strain relation will be validated with experimental tests results.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.62-70
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• 2023

We proposed a technique for predicting Stress-Life (S-N) curve or fatigue life using geometric features of a ply-overlap joint structure in which plies of two composite materials are partially or wholly laminated and bonded. Geometric features that could affect fatigue properties of a structure were selected as variables. By analyzing relationships between geometric variables and material constants of the Epaarachchi-Clausen model, a fatigue model for composites, relational expressions of these two factors were proposed. To verify the prediction accuracy of the proposed method, fatigue life of a CFRP/GFRP ply-overlap joint was predicted. Predicted life and life obtained by test data-based model were compared to actual life. High prediction accuracy was confirmed by calculating the coefficient of determination of the predicted S-N curve.

• Journal of the Korean Society of Radiology
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• v.18 no.5
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• pp.499-508
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• 2024

As a result of analyzing the spectrum using a ¹H-NMR spectrometer and a ¹H-NMR spectrum prediction program for Visipaque contrast agent, the molecular structure positions in the 2.18 ppm and 2.17 ppm regions were found to be different from each other. The 2.25 ppm and 2.34 ppm regions did not appear in the spectrum analysis using the spectrometer, but did appear in the analysis using the prediction program. In addition, the 2.58 ppm region appeared in the spectrum analysis using the spectrometer, but did not appear in the analysis using the prediction program. The 4.42 ppm region did not appear in the spectrum analysis using the spectrometer, but did appear in the analysis using the prediction program. In addition, the 5.61 ppm region appeared in the spectrum analysis using the spectrometer, but did not appear in the analysis using the prediction program. Based on this, it is thought that if we analyze it using the prediction program as a reference, we will be able to identify the chemical structure more clearly.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.153-156
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• 2000

본문에서는 예측형 회귀신경망과 HMM의 하이브리드 네트워크인 회귀신경망 예측 HMM을 구성하였다. 회귀신경망 예측 HMM은 예측형 회귀신경망을 HMM의 각 상태마다 예측기로 정의하여 일정치인 평균벡터 대신에 과거의 특징벡터의 영향을 받아 동적으로 변화하는 신경망에 의한 예측치를 이용하므로 학습패턴 설정자체가 시변성을 반영하는 동적 네트워크의 특성을 가진다. 따라서 음성과 같은 시계열 패턴의 인식에 유리하다. 회귀신경망 예측 HMM은 예측형 회귀신경망의 구조에 따라 Elman망 예측 HMM과 Jordan망 예측 HMM으로 구분하였다. 실험에서는 회귀신경망 예측 HMM의 상태수를 4, 5, 6으로 증가시켜 각 상태 수별로 예측차수 및 중간층 유니트 수의 변화에 따른 인식성능을 조사하였다. 실험결과 평가용. 데이터에 대하여 Elman망예측 HMM은 상태수가 6이고, 예측차수가 3차, 중간층 유니트의 수가 15차원일 때, Jordan망 예측 HMM의 경우 상태수가 5이고, 예측차수가 3차, 중간층 유니트의 수가 10차원일 때 각각 99.5%로 우수한 결과를 얻었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.519-526
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• 2018

In this study, an algorithm to predict evacuation routes in support of shipboard lifesaving activities is presented. As the first step of algorithm development, the feasibility and necessity of an evacuation route prediction algorithm are shown numerically. The proposed algorithm can be explained in brief as follows. This system continuously obtains and analyzes passenger movement data from the ship's monitoring system during non-disaster conditions. In case of a disaster, evacuation route prediction information is derived using the previously acquired data and a prediction tool, with the results provided to rescuers to minimize casualties. In this study, evacuation-related data obtained through fire evacuation trials was filtered and analyzed using a statistical method. In a simulation using the conventional evacuation prediction tool, it was found that reliable prediction results were obtained only in the SN1 trial because of the conceptual and structural nature of the tool itself. In order to verify the validity of the algorithm proposed in this study, an industrial engineering tool was adapted for evacuation characteristics prediction. When the proposed algorithm was implemented, the predicted values for average evacuation time and route were very similar to the measured values with error ranges of 0.6-6.9 % and 0.6-3.6 %, respectively. In the future, development of a high-performance evacuation route prediction algorithm is planned based on shipboard data monitoring and analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.331-334
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• 2009

본 논문에서는 계측을 통한 초고층 무량판 구조물의 횡강성 산정식의 유효성을 검정하였다. 초고층 건축물의 풍진동은 건축물의 사용성 평가에 중요한 구조설계요인 중 하나이다. 신뢰성 있는 풍하중 및 풍진동을 얻기위해서는 정확한 고유주기의 예측이 중요하며 고유주기 예측에 오차가 있을 경우 하중을 지나치게 과대평가하게 되는 문제를 유발하게 된다. 본 논문에서는 최근들어 국내에서 본격적으로 증가하고 있는 초고층 무량판 구조시스템의 건축물에 대한 해석 모델링과 실측을 통하여 추정된 무량판 초고층 건물의 동적특성을 바탕으로 구조해석과 동적거동의 계측을 통하여 내풍설계를 위한 횡강성 및 주기를 산정하는 연구를 수행하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.884-886
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• 2003

인간 지놈 프로젝트가 완료된 이후로 여러 지놈 프로젝트가 수행되었으며 이로 인해 데이터베이스에 수록되는 서열수가 기하급수적으로 증가하고 있다. 최근에는 단순한 서열 분석뿐만 아니라 이미 밟혀진 단백질 정보를 이용하여 새로운 단백질의 기능을 예측하는 연구가 보다 활발히 진행되고 있다. 단백질 기능은 단백질의 삼차구조에 의해 결정된다. 따라서 단백질의 서열을 분석하여 삼차구조를 알아내고 어떤 분류에 속하는지 알아낸다면 단백질의 기능을 예측할 수 있다. 본 논문에서는 단백질 서열 정렬을 통하여 보다 빠르고 효과적으로 단백질 구조 정보를 추출하는 기법에 대하여 기술한다. 개발된 단백질 구조 추출 기법은 Pfam 데이터베이스에서 제공하는 단백질 서열의 샘플링 결과를 기반으로 서열 정렬을 수행퇴고, 선정뭔 서열을 대상으로 SCOP 데이터베이스에서 단백질 구조 분류정보(family 및 fold)를 추출함으로써 구조 분류정보 추출 과정의 성능을 향상시키고자 한다.

• Computational Structural Engineering
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• v.11 no.3
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• pp.187-198
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• 1998

지하구조물의 건전성을 평가하기 위한 비파괴시험으로써 탄성응력파를 이용한 충격반향탐사법을 수치해석적인 방법을 통하여 수행하였다. 즉, 일면만으로 접근 가능한 터널 면에서의 충격가진과 동적응답의 측정으로 이질면을 포함한 내부의 상태를 예측할 수 있다. 연구의 수행은 탄성거동을 하는 매질 내부에서 전파되는 탄성응력파의 특성을 이해하고, 이를 동적 유한요소해석으로 모형화하여 충격반향탐사법을 수치해석적으로 수행한다. 이질재료가 2개의 층을 이루고 있는 경우 표면층의 두께를 쉽게 측정할 수 있었으며, 구조물의 병진운동, 휨운동과 구조물 내에서 다중반사되는 탄성응력파에 의한 복합적인 영향을 받는 터널과 같은 원통형 구조물에서 동적응답의 주파수 특성으로부터 터널라이닝 내부에 형성된 공동의 위치와 크기의 예측이 가능하였다. 수치해석적인 방법과 병행하여 다양한 형태의 경계조건을 가지는 구조물에 대한 충격반향탐사법의 실험을 수행할 경우 실제적인 문제에 적용, 건전성 평가의 지표를 마련할 수 있을 것으로 사료된다.