• Title/Summary/Keyword: Probabilistic modeling

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A Micromechanics-based Elastic Model for Particle-Reinforced Composites Containing Slightly Weakened Interfaces (미소한 손상경계면을 갖는 입자강화 복합재료의 미세역학 탄성 모델에 관한 연구)

  • Lee, Haeng-Ki;Pyo, Suk-Hoon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.441-444
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    • 2007
  • This paper presents a part of micormechanics-based elastic modeling (Lee and Pyo, 2007) of particle-reinforced composites containing slightly weakened interfaces. The Eshelby's tensor for a damaged ellipsoidal inclusion to model particles with slightly weakened interfaces is incorporated into a micormechanical formulation by Ju and Chen (1994). A damage model in accordance with the Weibull's probabilistic function is also developed to simulate the progression of weakened interface in the composites.

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Retrieve System for Performance support of Vocabulary Clustering Model In Continuous Vocabulary Recognition System (연속 어휘 인식 시스템에서 어휘 클러스터링 모델의 성능 지원을 위한 검색 시스템)

  • Oh, Sang Yeob
    • Journal of Digital Convergence
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    • v.10 no.9
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    • pp.339-344
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    • 2012
  • Established continuous vocabulary recognition system improved recognition rate by using decision tree based tying modeling method. However, since system model cannot support the retrieve of phoneme data, it is hard to secure the accuracy. In order to improve this problem, we remodeled a system that could retrieve probabilistic model from continuous vocabulary clustering model to phoneme unit. Therefore in this paper showed 95.88%of recognition rate in system performance.

Multi-level structural modeling of an offshore wind turbine

  • Petrini, Francesco;Gkoumas, Konstantinos;Zhou, Wensong;Li, Hui
    • Ocean Systems Engineering
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    • v.2 no.1
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    • pp.1-16
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    • 2012
  • Offshore wind turbines are complex structural and mechanical systems located in a highly demanding environment. This paper proposes a multi-level system approach for studying the structural behavior of the support structure of an offshore wind turbine. In accordance with this approach, a proper numerical modeling requires the adoption of a suitable technique in order to organize the qualitative and quantitative assessment in various sub-problems, which can be solved by means of sub-models at different levels of detail, both for the structural behavior and for the simulation of loads. Consequently, in a first place, the effects on the structural response induced by the uncertainty of the parameters used to describe the environmental actions and the finite element model of the structure are inquired. After that, a meso-level FEM model of the blade is adopted in order to obtain the detailed load stress on the blade/hub connection.

Probability-Based Prediction of Time to Corrosion Initiation of RC Structure Exposed to Salt Attack Environment Considering Uncertainties (불확실성을 고려한 RC구조물의 부식개시시기에 대한 확률 기반 예측)

  • Kim, Jin-Su;Do, Jeong-Yun;Hun, Seung;Soh, Seung-Young;Soh, Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.249-252
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    • 2005
  • Chloride ingress is a common cause of deterioration of reinforced concrete structures. Modeling the chloride ingress is an important basis for designing reinforced concrete structures and for assessing the reliability of an existing structure. The modelling is also needed for predicting the deterioration of a reinforced structure. This paper presents an approach for the probabilistic modeling of the chloride-induced corrosion of reinforcement steel in concrete structures that takes into account the uncertainties in the physical models. The parameters of the models are modeled as random variables and the distribution of the corrosion time and probability of corrosion are determined by using Monte Carlo simulation. The predictions of the proposed model is very effective to do the decision-making about initiation time and deterioration degree.

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Combination of Classifiers Decisions for Multilingual Speaker Identification

  • Nagaraja, B.G.;Jayanna, H.S.
    • Journal of Information Processing Systems
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    • v.13 no.4
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    • pp.928-940
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    • 2017
  • State-of-the-art speaker recognition systems may work better for the English language. However, if the same system is used for recognizing those who speak different languages, the systems may yield a poor performance. In this work, the decisions of a Gaussian mixture model-universal background model (GMM-UBM) and a learning vector quantization (LVQ) are combined to improve the recognition performance of a multilingual speaker identification system. The difference between these classifiers is in their modeling techniques. The former one is based on probabilistic approach and the latter one is based on the fine-tuning of neurons. Since the approaches are different, each modeling technique identifies different sets of speakers for the same database set. Therefore, the decisions of the classifiers may be used to improve the performance. In this study, multitaper mel-frequency cepstral coefficients (MFCCs) are used as the features and the monolingual and cross-lingual speaker identification studies are conducted using NIST-2003 and our own database. The experimental results show that the combined system improves the performance by nearly 10% compared with that of the individual classifier.

A Study of Statistical Analysis of Rock Joint Directional Data (암반 절리 방향성 자료의 통계적 분석 기법에 관한 연구)

  • 류동우;김영민;이희근
    • Tunnel and Underground Space
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    • v.12 no.1
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    • pp.19-30
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    • 2002
  • Rock joint orientation is one of important geometric attributes that have an influence on the stability of rock structures such as rock slopes and tunnels. Especially, statistical models of the geometric attributes of rock joints can provide a probabilistic approach of rock engineering problems. The result from probabilistic modeling relies on the choice of statistical model. Therefore, it is critical to define a representative statistical model for joint orientation data as well as joint size and intensity and build up a series of modeling procedure including analytical validation. In this paper, we have examined a theoretical methodology for the statistical estimate and hypothesis analysis based upon Fisher distribution and bivariate normal distribution. In addition, we have proposed the algorithms of random number generator which is applied to the simulation of rock joint networks and risk analysis.

Dynamic Bayesian Network Modeling and Reasoning Based on Ontology for Occluded Object Recognition of Service Robot (서비스 로봇의 가려진 물체 인식을 위한 온톨로지 기반 동적 베이지안 네트워크 모델링 및 추론)

  • Song, Youn-Suk;Cho, Sung-Bae
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.2
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    • pp.100-109
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    • 2007
  • Object recognition of service robots is very important for most of services such as delivery, and errand. Conventional methods are based on the geometric models in static industrial environments, but they have limitations in indoor environments where the condition is changable and the movement of service robots occur because the interesting object can be occluded or small in the image according to their location. For solving these uncertain situations, in this paper, we propose the method that exploits observed objects as context information for predicting interesting one. For this, we propose the method for modeling domain knowledge in probabilistic frame by adopting Bayesian networks and ontology together, and creating knowledge model dynamically to extend reasoning models. We verify the performance of our method through the experiments and show the merit of inductive reasoning in the probabilistic model

Development of Prediction Method for Highway Pavement Condition (포장상태 예측방법 개선에 관한 연구)

  • Park, Sang-Wook;Suh, Young-Chan;Chung, Chul-Gi
    • International Journal of Highway Engineering
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    • v.10 no.3
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    • pp.199-208
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    • 2008
  • Prediction the performance of pavement provides proper information to an agency on decision-making process; especially evaluating the pavement performance and prioritizing the work plan. To date, there are a number of approaches to predict the future deterioration of pavements. However, there are some limitation to proper prediction of the pavement service life. In this paper, pavement performance model and pavement condition prediction model are developed in order to improve pavement condition prediction method. The prediction model of pavement condition through the regression analysis of real pavement condition is based on the probability distribution of pavement condition, which set to 5%, 15%, 25% and 50%, by condition of the pavement and traffic volume. The pavement prediction model presented from the behavior of individual pavement condition which are set to 5%, 15%, 25% and 50% of probability distribution. The performance of the prediction model is evaluated from analyzing the average, standard deviation of HPCI, and the percentage of HPCI which is lower than 3.0 of comparable section. In this paper, we will suggest the more rational method to determine the future pavement conditions, including the probabilistic duration and deterministic modeling methods regarding the impact of traffic volume, age, and the type of the pavement.

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A Study on the Probabilistic Vulnerability Assessment of COTS O/S based I&C System (상용 OS기반 제어시스템 확률론적 취약점 평가 방안 연구)

  • Euom, Ieck-Chae
    • Journal of Convergence for Information Technology
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    • v.9 no.8
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    • pp.35-44
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    • 2019
  • The purpose of this study is to find out quantitative vulnerability assessment about COTS(Commercial Off The Shelf) O/S based I&C System. This paper analyzed vulnerability's lifecycle and it's impact. this paper is to develop a quantitative assessment of overall cyber security risks and vulnerabilities I&C System by studying the vulnerability analysis and prediction method. The probabilistic vulnerability assessment method proposed in this study suggests a modeling method that enables setting priority of patches, threshold setting of vulnerable size, and attack path in a commercial OS-based measurement control system that is difficult to patch an immediate vulnerability.

Assessment of modal parameters considering measurement and modeling errors

  • Huang, Qindan;Gardoni, Paolo;Hurlebaus, Stefan
    • Smart Structures and Systems
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    • v.15 no.3
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    • pp.717-733
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    • 2015
  • Modal parameters of a structure are commonly used quantities for system identification and damage detection. With a limited number of studies on the statistics assessment of modal parameters, this paper presents procedures to properly account for the uncertainties present in the process of extracting modal parameters. Particularly, this paper focuses on how to deal with the measurement error in an ambient vibration test and the modeling error resulting from a modal parameter extraction process. A bootstrap approach is adopted, when an ensemble of a limited number of noised time-history response recordings is available. To estimate the modeling error associated with the extraction process, a model prediction expansion approach is adopted where the modeling error is considered as an "adjustment" to the prediction obtained from the extraction process. The proposed procedures can be further incorporated into the probabilistic analysis of applications where the modal parameters are used. This study considers the effects of the measurement and modeling errors and can provide guidance in allocating resources to improve the estimation accuracy of the modal data. As an illustration, the proposed procedures are applied to extract the modal data of a damaged beam, and the extracted modal data are used to detect potential damage locations using a damage detection method. It is shown that the variability in the modal parameters can be considered to be quite low due to the measurement and modeling errors; however, this low variability has a significant impact on the damage detection results for the studied beam.