• 제목/요약/키워드: operator domain

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Framework for Content-Based Image Identification with Standardized Multiview Features

  • Das, Rik;Thepade, Sudeep;Ghosh, Saurav
    • ETRI Journal
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    • 제38권1호
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    • pp.174-184
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    • 2016
  • Information identification with image data by means of low-level visual features has evolved as a challenging research domain. Conventional text-based mapping of image data has been gradually replaced by content-based techniques of image identification. Feature extraction from image content plays a crucial role in facilitating content-based detection processes. In this paper, the authors have proposed four different techniques for multiview feature extraction from images. The efficiency of extracted feature vectors for content-based image classification and retrieval is evaluated by means of fusion-based and data standardization-based techniques. It is observed that the latter surpasses the former. The proposed methods outclass state-of-the-art techniques for content-based image identification and show an average increase in precision of 17.71% and 22.78% for classification and retrieval, respectively. Three public datasets - Wang; Oliva and Torralba (OT-Scene); and Corel - are used for verification purposes. The research findings are statistically validated by conducting a paired t-test.

A Study on an Adaptive Membership Function for Fuzzy Inference System

  • Bang, Eun-Oh;Chae, Myong-Gi;Lee, Snag-Bae;Tack, Han-Ho;Kim, Il
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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    • pp.532-538
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    • 1998
  • In this paper, a new adaptive fuzzy inference method using neural network based fuzzy reasoning is proposed to make a fuzzy logic control system more adaptive and more effective. In most cases, the design of a fuzzy inference system rely on the method in which an expert or a skilled human operator would operate in that special domain. However, if he has not expert knowledge for any nonlinear environment, it is difficult to control in order to optimize. Thus, using the proposed adaptive structure for the fuzzy reasoning system can controled more adaptive and more effective in nonlinear environment for changing input membership functions and output membership functions. The proposed fuzzy inference algorithm is called adaptive neuro-fuzzy control(ANFC). ANFC can adapt a proper membership function for nonlinear plant, based upon a minimum number of rules and an initial approximate membership function. Nonlinear function approximation and rotary inverted pendulum control system ar employed to demonstrate the viability of the proposed ANFC.

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Eulerian-Lagrangian 농도 및 입자 결합모형에 의한 연안의 부유사 확산해석 (Suspended Solid Dispersion Analysis for Coastal Areas Using Hybrid Concept of Particle and Concentration of Eulerian-Lagrangian Model)

  • 서승원
    • 한국해안해양공학회지
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    • 제8권2호
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    • pp.185-192
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    • 1996
  • 연안에서의 효율적인 확산해석을 위해 연산자 분리기법에 의한 Eulerian-Lagrangian 농도모형과 random walk 방법이 결합된 모형이 수립되었다 수립한 입자추적모형은 특히 고농도 변화 지역에서 오차 없이 만족스럽게 해석할 수 있는 수단으로 판단된다. 모형실험결과 오염원 방류초기의 ▽C$\geq$0.005에서 거의 정확해와 일치하는 결과를 얻었고, ▽C$\leq$0.002에서는 만족스럽지 못한 결과가 유도되어 입자추적모형의 적용한계의 기준으로 제시되었다. 따라서 실제 해역에서의 적용에서 고농도의 오염원이 발생되는 근역에서는 입자추적모형을 적용하고 이후의 전역에 대해서는 농도모형을 이용하여 해석상의 능률 제고와 정도의 향상을 도모할 수 있었다.

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잠수함의 침수시 대응을 위한 지식기반시스템에 관한 연구 (A Study on Knowledge Based System for Submarines Leakages)

  • 이동곤;이재용;이재환;이경호
    • 대한조선학회논문집
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    • 제38권3호
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    • pp.107-116
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    • 2001
  • 잠수함은 수중 활동으로 인하여 압력선체에 항상 수압을 받고 있기 때문에, 손상시에는 수상함에 비하여 그 영향이 상대적으로 크며 대처 가능한 수단과 시간은 제한되어 있다. 수압으로 인하여 작은 파손에도 잠수함이 치명적인 손상을 받을 수 있으며, 이는 곧 함의 임무 수행능력의 손실뿐만 아니라 승조원의 안전에도 직결되는 상황을 초래할 수 있다. 본 연구에서는 잠수함의 손상시, 크게 압력선체 손상과 배관 계통이 손상된 경우만을 고려하여 두 경우 누수가 발생하였을 경우에 효과적으로 대응할 수 있는 지식기반시스템을 개발하였다. 잠수함의 설계 지침서와 설계 경험을 바탕으로 잠수함의 운용자로부터 위기 대응과 관련된 지식을 추출하여 분석, 정리하였고 도출된 지식들은 지식기반시스템 개발도구를 사용하여 규칙의 형태로 지식베이스에 저장하였으며, 후향 추론기법을 사용하여 상황대처에 대한 결과를 도출하였다.

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Improvement of inspection system for common crossings by track side monitoring and prognostics

  • Sysyn, Mykola;Nabochenko, Olga;Kovalchuk, Vitalii;Gruen, Dimitri;Pentsak, Andriy
    • Structural Monitoring and Maintenance
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    • 제6권3호
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    • pp.219-235
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    • 2019
  • Scheduled inspections of common crossings are one of the main cost drivers of railway maintenance. Prognostics and health management (PHM) approach and modern monitoring means offer many possibilities in the optimization of inspections and maintenance. The present paper deals with data driven prognosis of the common crossing remaining useful life (RUL) that is based on an inertial monitoring system. The problem of scheduled inspections system for common crossings is outlined and analysed. The proposed analysis of inertial signals with the maximal overlap discrete wavelet packet transform (MODWPT) and Shannon entropy (SE) estimates enable to extract the spectral features. The relevant features for the acceleration components are selected with application of Lasso (Least absolute shrinkage and selection operator) regularization. The features are fused with time domain information about the longitudinal position of wheels impact and train velocities by multivariate regression. The fused structural health (SH) indicator has a significant correlation to the lifetime of crossing. The RUL prognosis is performed on the linear degradation stochastic model with recursive Bayesian update. Prognosis testing metrics show the promising results for common crossing inspection scheduling improvement.

A modularized numerical framework for the process-based total system performance assessment of geological disposal systems

  • Kim, Jung-Woo;Jang, Hong;Lee, Dong Hyuk;Cho, Hyun Ho;Lee, Jaewon;Kim, Minjeong;Ju, Heejae
    • Nuclear Engineering and Technology
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    • 제54권8호
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    • pp.2828-2839
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    • 2022
  • This study developed a safety assessment tool for geological disposal systems called APro, a systemically integrated modeling system based on modularizing and coupling the processes which need to be considered in a geological disposal system. Thermal, hydraulic, chemical, canister failure, radionuclide release and transport processes were considered in the current version of APro. Each of the unit processes in APro consists of a single Default Module, and several Alternative Modules which can increase the flexibility of the model. As an initial stage of developing the modularization concept and modeling interface, the Default Modules of each unit process were described, with one Alternative Module of chemical process. The computation part of APro is mainly a MATLAB workspace controlling COMSOL and PHREEQC, which are coupled by an operator splitting scheme. The APro model domain is a stylized geological disposal system employing the Swedish disposal concept (KBS-3 type), but the repository layout can be freely adjusted. In order to show the applicability of APro to the total system performance assessment of geological disposal system, some sample simulations were conducted. From the results, it was confirmed that coupling of the thermal and hydraulic processes and coupling of the canister failure and the radionuclide release processes were well reflected in APro. In addition, the technical connectivity between COMSOL and PHREEQC was also confirmed.

Seismic capacity evaluation of fire-damaged cabinet facility in a nuclear power plant

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1331-1344
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    • 2021
  • This study is to evaluate the seismic capacity of the fire-damaged cabinet facility in a nuclear power plant (NPP). A prototype of an electrical cabinet is modeled using OpenSees for the numerical simulation. To capture the nonlinear behavior of the cabinet, the constitutive law of the material model under the fire environment is considered. The experimental record from the impact hammer test is extracted trough the frequency-domain decomposition (FDD) method, which is used to verify the effectiveness of the numerical model through modal assurance criteria (MAC). Assuming different temperatures, the nonlinear time history analysis is conducted using a set of fifty earthquakes and the seismic outputs are investigated by the fragility analysis. To get a threshold of intensity measure, the Monte Carlo Simulation (MCS) is adopted for uncertainty reduction purposes. Finally, a capacity estimation model has been proposed through the investigation, which will be helpful for the engineer or NPP operator to evaluate the fire-damaged cabinet strength under seismic excitation. This capacity model is presented in terms of the High Confidence of Low Probability of Failure (HCLPF) point. The results are validated by the proper judgment and can be used to analyze the influences of fire on the electrical cabinet.

IBN 기반: AI 기반 멀티 도메인 네트워크 슬라이싱 접근법 (IBN-based: AI-driven Multi-Domain e2e Network Orchestration Approach)

  • 칸 탈하 애흐마드;아팍 모하메드;기자르 아바쓰;송왕철
    • KNOM Review
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    • 제23권2호
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    • pp.29-41
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    • 2020
  • 네트워크는 빠르게 성장하여 다중 도메인 복잡성을 유발하고 있다. 네트워크 트래픽 및 서비스의 다양성, 다양성 및 동적 특성은 향상된 오케스트레이션 및 관리 접근 방식을 필요로한다. 많은 표준 오케스트레이터와 네트워크 운영자가 E2E 슬라이스 오케스트레이션을 처리하기 위한 복잡성이 증가하고 있다. 또한 액세스, 에지, 전송 및 코어 네트워크를 포함하여 E2E 슬라이스 오케스트레이션과 관련된 여러 도메인이 각각 특정 문제를 가지고 있다. 따라서 멀티 도메인, 멀티 플랫폼 및 멀티 오퍼레이터 기반 네트워킹 환경을 수동으로 처리하려면 특정 전문가가 필요하며 이 접근 방식을 사용하면 런타임에 네트워크의 동적 변경을 처리할 수 없다 또한 이러한 복잡성을 처리하기위한 수동 접근 방식은 항상 오류가 발생하기 쉽고 지루한 일이다. 따라서 본 연구에서는 의도 기반 접근법을 사용하여 E2E 슬라이스 오케스트레이션을 처리하기 위한 자동화되고 추상화된 솔루션을 제안한다. 운영자로부터 도메인을 추상화하고 높은 수준의 의도 형태로 오케스트레이션 의도를 제공 할 수 있다. 또한 조정 된 리소스를 적극적으로 모니터링하고 머신 러닝을 사용하여 현재 모니터링 통계를 기반으로 시스템 상태 업데이트를 위한 향후 리소스 활용도를 예측한다. Closed-loop 자동화 E2E 네트워크 오케스트레이션 및 관리 시스템이 생성된다.

잠수함 수동소나 시뮬레이터 알고리즘 (An Algorithm for Submarine Passive Sonar Simulator)

  • 정영철;김병욱;안상겸;성우제;이근화;한주영
    • 한국음향학회지
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    • 제32권6호
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    • pp.472-483
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    • 2013
  • 잠수함 소나 운용 요원의 능력을 향상시키기 위한 실제 해상 훈련은 많은 비용과 제약사항이 따른다. 소나 시뮬레이터는 이러한 문제점을 해결하고, 실제와 유사한 전장 환경을 모의함으로써 소나 운용 요원의 능력과 훈련 성과를 극대화시킨다. 본 연구에서는 수동 소나 시뮬레이터의 알고리즘을 제시하였으며, 알고리즘은 기동모듈, 소음원모듈, 소음 전달 모듈의 3가지 모듈로 나뉘었다. 기동모듈은 3차원 좌표계를 이용하여 함정의 기동을 구현하였으며, 시간 간격은 함정의 변침률에 따라 설정하였다. 소음원 모듈은 표적 소음, 해양 배경 소음, 자체소음으로 구성하였다. 표적 소음은 주파수 특성에 따라 비변조 협대역, 변조 협대역, 비변조 광대역, 변조 광대역 신호로 구분하였으며, 톤수와 속력에 의존하는 함정 방사소음 준위를 적용하였다. 해양 배경 소음은 음향도파관 효과가 고려된 바람 소음과 그외 배경 소음으로 모의하였으며, 자체소음은 유체소음과 소나돔 삽입 손실로 모의하였다. 소음 전달 모듈은 음선 기반의 모델을 이용하였으며, 기동 모듈의 각 시간에서 고유음선의 진폭, 위상, 시간지연을 합산하여 주파수 영역에서 표적 소음에 곱하였다. 최종적으로 시나리오에 따른 모의 결과 실제 해양에서 발생하는 소음과 유사한 경향을 확인할 수 있었다.

e-러닝 성과에 영향을 미치는 품질요인에 관한 연구 (What Quality Factors Affect to the e-Learning Performance)

  • 김성균;성행남;정대율
    • 한국정보시스템학회지:정보시스템연구
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    • 제16권1호
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    • pp.201-230
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    • 2007
  • Recently, the growth of e-Learning systems and its related information technology has presented a unique challenge for both schools and industry. It would make an extremely phenomenal paradigm shift in the educational method and practice. Methods of assessing the quality of e-teaming services and contents are critical issue in both practice and research. Moreover, many researchers are interested in what qualify factors more affect to the Performance of e-Learning service. Nevertheless, service quality is a construct that is difficult to define and measure. e-Learning services are composed of many factors, and they are more complicated than the traditional education services because they we performed on the distance basis and the many platforms of IT infrastructure. The purposes of our research are to classify the e-Learning service dimension and identify their factors, to develop the measurement of the factors, and finally to test empirically their relationship between the service factors and e-Learning service performance. For the development of the service factors we considered SERVQUAL model and SERVPERF model which were developed in the service marketing area. The SERVQUAL model was more fitted to the e-Learning services than the latter. From that we derived several factors that fit to our research domain, ie, tangibles, access, reliability, credibility, security, responsiveness, assurance, empathy. We combined three factors of them(reliability, credibility, security) into a factor, system stability for the semantic simplicity, and divided responsiveness factor into system operator responsiveness and teacher responsiveness as the entity based dimension classification. In the e-Learning services research, Most researcher are mentioned the quality factors of contents, so we added to two contents quality factors, ie, contents production method and richness of contents itself. We examined the relationship between the service quality factors and e-Learning performance(student satisfaction and service reuse intention). As result three quality factors(contents production method, teacher responsiveness, empathy) significantly affected student satisfaction. To the other performance variable, ie, service reuse intention, the teacher related quality factors(such as teacher responsiveness, assurance, empathy) affected only. In conclusion, even in the on-line distance teaming, the teacher's role md earnestness is as important as ever.

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