• Title/Summary/Keyword: Data Inference

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Computer Program Development for Two Populations Inference

  • Choi, Hyun-Seok;Choi, Sung-Woo;Kim, Tae-Yoon
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.2
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    • pp.185-193
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    • 2005
  • This study develops and introduces the program for letting learners study statistics in a systematic and efficient way by using Excel tools such as VBA and Macro, when they study statistical inference at two populations. This study helps learners understand the steps on statistical inference at two populations by utilizing the systematic and visual techniques.

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Fault Diagnosis in Gas Turbine Engine Using Fuzzy Inference Logic (퍼지 로직 시스템을 이용한 항공기 가스터빈 엔진 오류 검출에 대한 연구)

  • Mo, Eun-Jong;Jie, Min-Seok;Kim, Chin-Su;Lee, Kang-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.1
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    • pp.49-53
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    • 2008
  • A fuzzy inference logic system is proposed for gas turbine engine fault isolation. The gas path measurements used for fault isolation are exhaust gas temperature, low and high rotor speed, and fuel flow. The fuzzy inference logic uses rules developed from a model of performance influence coefficients to isolate engine faults while accounting for uncertainty in gas path measurements. Inputs to the fuzzy inference logic system are measurement deviations of gas path parameters which are transferred directly from the ECM(Engine Control Monitoring) program and outputs are engine module faults. The proposed fuzzy inference logic system is tested using simulated data developed from the ECM trend plot reports and the results show that the proposed fuzzy inference logic system isolates module faults with high accuracy rate in the environment of high level of uncertainty.

Multiple Comparison for the One-Way ANOVA with the Power Prior

  • Bae, Re-Na;Kang, Yun-Hee;Hong, Min-Young;Kim, Seong-W.
    • Communications for Statistical Applications and Methods
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    • v.15 no.1
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    • pp.13-26
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    • 2008
  • Inference on the present data will be more reliable when the data arising from previous similar studies are available. The data arising from previous studies are referred as historical data. The power prior is defined by the likelihood function based on the historical data to the power $a_0$, where $0\;{\le}\;a_0\;{\le}\;1$. The power prior is a useful informative prior for Bayesian inference such as model selection and model comparison. We utilize the historical data to perform multiple comparison in the one-way ANOVA model. We demonstrate our results with some simulated datasets under a simple order restriction between the treatments.

A Study on the Fault Diagnosis System for Combustion System of Diesel Engines Using Knowledge Based Fuzzy Inference (지식기반 퍼지 추론을 이용한 디젤기관 연소계통의 고장진단 시스템에 관한 연구)

  • 유영호;천행춘
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.1
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    • pp.42-48
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    • 2003
  • In general many engineers can diagnose the fault condition using the abnormal ones among data monitored from a diesel engine, but they don't need the system modelling or identification for the work. They check the abnormal data and the relationship and then catch the fault condition of the engine. This paper proposes the construction of a fault diagnosis engine through malfunction data gained from the data fault detection system of neural networks for diesel generator engine, and the rule inference method to induce the rule for fuzzy inference from the malfunction data of diesel engine like a site engineer with a fuzzy system. The proposed fault diagnosis system is constructed in the sense of the Malfunction Diagnosis Engine(MDE) and Hierarchy of Malfunction Hypotheses(HMH). The system is concerned with the rule reduction method of knowledge base for related data among the various interactive data.

An Optimization Technique for RDFS Inference the Applied Order of RDF Schema Entailment Rules (RDF 스키마 함의 규칙 적용 순서를 이용한 RDFS 추론 엔진의 최적화)

  • Kim, Ki-Sung;Yoo, Sang-Won;Lee, Tae-Whi;Kim, Hyung-Joo
    • Journal of KIISE:Databases
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    • v.33 no.2
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    • pp.151-162
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    • 2006
  • RDF Semantics, one of W3C Recommendations, provides the RDFS entailment rules, which are used for the RDFS inference. Sesame, which is well known RDF repository, supports the RDBMS-based RDFS inference using the forward-chaining strategy. Since inferencing in the forward-chaining strategy is performed in the data loading time, the data loading time in Sesame is slow down be inferencing. In this paper, we propose the order scheme for applying the RDFS entailment rules to improve inference performance. The proposed application order makes the inference process terminate without repetition of the process for most cases and guarantees the completeness of inference result. Also the application order helps to reduce redundant results during the inference by predicting the results which were made already by previously applied rules. In this paper, we show that our approaches can improve the inference performance with comparisons to the original Sesame using several real-life RDF datasets.

A Label Inference Algorithm Considering Vertex Importance in Semi-Supervised Learning (준지도 학습에서 꼭지점 중요도를 고려한 레이블 추론)

  • Oh, Byonghwa;Yang, Jihoon;Lee, Hyun-Jin
    • Journal of KIISE
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    • v.42 no.12
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    • pp.1561-1567
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    • 2015
  • Abstract Semi-supervised learning is an area in machine learning that employs both labeled and unlabeled data in order to train a model and has the potential to improve prediction performance compared to supervised learning. Graph-based semi-supervised learning has recently come into focus with two phases: graph construction, which converts the input data into a graph, and label inference, which predicts the appropriate labels for unlabeled data using the constructed graph. The inference is based on the smoothness assumption feature of semi-supervised learning. In this study, we propose an enhanced label inference algorithm by incorporating the importance of each vertex. In addition, we prove the convergence of the suggested algorithm and verify its excellence.

A Study on the Adaptive Polynomial Neuro-Fuzzy Networks Architecture (적응 다항식 뉴로-퍼지 네트워크 구조에 관한 연구)

  • Oh, Sung-Kwun;Kim, Dong-Won
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.9
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    • pp.430-438
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    • 2001
  • In this study, we introduce the adaptive Polynomial Neuro-Fuzzy Networks(PNFN) architecture generated from the fusion of fuzzy inference system and PNN algorithm. The PNFN dwells on the ideas of fuzzy rule-based computing and neural networks. Fuzzy inference system is applied in the 1st layer of PNFN and PNN algorithm is employed in the 2nd layer or higher. From these the multilayer structure of the PNFN is constructed. In order words, in the Fuzzy Inference System(FIS) used in the nodes of the 1st layer of PNFN, either the simplified or regression polynomial inference method is utilized. And as the premise part of the rules, both triangular and Gaussian like membership function are studied. In the 2nd layer or higher, PNN based on GMDH and regression polynomial is generated in a dynamic way, unlike in the case of the popular multilayer perceptron structure. That is, the PNN is an analytic technique for identifying nonlinear relationships between system's inputs and outputs and is a flexible network structure constructed through the successive generation of layers from nodes represented in partial descriptions of I/O relatio of data. The experiment part of the study involves representative time series such as Box-Jenkins gas furnace data used across various neurofuzzy systems and a comparative analysis is included as well.

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A TSK fuzzy model optimization with meta-heuristic algorithms for seismic response prediction of nonlinear steel moment-resisting frames

  • Ebrahim Asadi;Reza Goli Ejlali;Seyyed Arash Mousavi Ghasemi;Siamak Talatahari
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.189-208
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    • 2024
  • Artificial intelligence is one of the efficient methods that can be developed to simulate nonlinear behavior and predict the response of building structures. In this regard, an adaptive method based on optimization algorithms is used to train the TSK model of the fuzzy inference system to estimate the seismic behavior of building structures based on analytical data. The optimization algorithm is implemented to determine the parameters of the TSK model based on the minimization of prediction error for the training data set. The adaptive training is designed on the feedback of the results of previous time steps, in which three training cases of 2, 5, and 10 previous time steps were used. The training data is collected from the results of nonlinear time history analysis under 100 ground motion records with different seismic properties. Also, 10 records were used to test the inference system. The performance of the proposed inference system is evaluated on two 3 and 20-story models of nonlinear steel moment frame. The results show that the inference system of the TSK model by combining the optimization method is an efficient computational method for predicting the response of nonlinear structures. Meanwhile, the multi-vers optimization (MVO) algorithm is more accurate in determining the optimal parameters of the TSK model. Also, the accuracy of the results increases significantly with increasing the number of previous steps.

Optimization of Fuzzy Systems by Means of GA and Weighting Factor (유전자 알고리즘과 하중값을 이용한 퍼지 시스템의 최적화)

  • Park, Byoung-Jun;Oh, Sung-Kwun;Ahn, Tae-Chon;Kim, Hyun-Ki
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.6
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    • pp.789-799
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    • 1999
  • In this paper, the optimization of fuzzy inference systems is proposed for fuzzy model of nonlinear systems. A fuzzy model needs to be identified and optimized by means of the definite and systematic methods, because a fuzzy model is primarily acquired by expert's experience. The proposed rule-based fuzzy model implements system structure and parameter identification using the HCM(Hard C-mean) clustering method, genetic algorithms and fuzzy inference method. Two types of inference methods of a fuzzy model are the simplified inference and linear inference. in this paper, nonlinear systems are expressed using the identification of structure such as input variables and the division of fuzzy input subspaces, and the identification of parameters of a fuzzy model. To identify premise parameters of fuzzy model, the genetic algorithms is used and the standard least square method with the gaussian elimination method is utilized for the identification of optimum consequence parameters of fuzzy model. Also, the performance index with weighting factor is proposed to achieve a balance between the performance results of fuzzy model produced for the training and testing data set, and it leads to enhance approximation and predictive performance of fuzzy system. Time series data for gas furnace and sewage treatment process are used to evaluate the performance of the proposed model.

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Performance analysis of local exit for distributed deep neural networks over cloud and edge computing

  • Lee, Changsik;Hong, Seungwoo;Hong, Sungback;Kim, Taeyeon
    • ETRI Journal
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    • v.42 no.5
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    • pp.658-668
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    • 2020
  • In edge computing, most procedures, including data collection, data processing, and service provision, are handled at edge nodes and not in the central cloud. This decreases the processing burden on the central cloud, enabling fast responses to end-device service requests in addition to reducing bandwidth consumption. However, edge nodes have restricted computing, storage, and energy resources to support computation-intensive tasks such as processing deep neural network (DNN) inference. In this study, we analyze the effect of models with single and multiple local exits on DNN inference in an edge-computing environment. Our test results show that a single-exit model performs better with respect to the number of local exited samples, inference accuracy, and inference latency than a multi-exit model at all exit points. These results signify that higher accuracy can be achieved with less computation when a single-exit model is adopted. In edge computing infrastructure, it is therefore more efficient to adopt a DNN model with only one or a few exit points to provide a fast and reliable inference service.