• 제목/요약/키워드: Model based

검색결과 59,709건 처리시간 0.072초

모델링 오차를 고려한 교량의 손상추정 (Damage Detection for Bridges Considering Modeling Errors)

  • 윤정방;이종재;이종원;정희영
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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    • pp.300-307
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    • 2002
  • Damage estimation methods are classified into two groups according to the dependence on the FE model : signal-based and model-based methods. Signal-based damage estimation methods are generally appropriate for detection of damage location, whereas not effective for estimation of damage severities. Model-based damage estimation methods are difficult to apply directly to the structures with a large number of the probable damaged members. It is difficult to obtain the exact model representing the real bridge behavior due to the modeling errors. The modeling errors even may exceed the modal sensitivity on damage. In this study, Model-based damage detection method which can effectively consider the modeling errors is suggested. Two numerical example analyses on a simple beam and a multi-girder bridge are presented to demonstrate the effectiveness of the presented method.

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Privacy Protection Model for Location-Based Services

  • Ni, Lihao;Liu, Yanshen;Liu, Yi
    • Journal of Information Processing Systems
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    • 제16권1호
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    • pp.96-112
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    • 2020
  • Solving the disclosure problem of sensitive information with the k-nearest neighbor query, location dummy technique, or interfering data in location-based services (LBSs) is a new research topic. Although they reduced security threats, previous studies will be ineffective in the case of sparse users or K-successive privacy, and additional calculations will deteriorate the performance of LBS application systems. Therefore, a model is proposed herein, which is based on geohash-encoding technology instead of latitude and longitude, memcached server cluster, encryption and decryption, and authentication. Simulation results based on PHP and MySQL show that the model offers approximately 10× speedup over the conventional approach. Two problems are solved using the model: sensitive information in LBS application is not disclosed, and the relationship between an individual and a track is not leaked.

Proper Noun Embedding Model for the Korean Dependency Parsing

  • Nam, Gyu-Hyeon;Lee, Hyun-Young;Kang, Seung-Shik
    • Journal of Multimedia Information System
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    • 제9권2호
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    • pp.93-102
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    • 2022
  • Dependency parsing is a decision problem of the syntactic relation between words in a sentence. Recently, deep learning models are used for dependency parsing based on the word representations in a continuous vector space. However, it causes a mislabeled tagging problem for the proper nouns that rarely appear in the training corpus because it is difficult to express out-of-vocabulary (OOV) words in a continuous vector space. To solve the OOV problem in dependency parsing, we explored the proper noun embedding method according to the embedding unit. Before representing words in a continuous vector space, we replace the proper nouns with a special token and train them for the contextual features by using the multi-layer bidirectional LSTM. Two models of the syllable-based and morpheme-based unit are proposed for proper noun embedding and the performance of the dependency parsing is more improved in the ensemble model than each syllable and morpheme embedding model. The experimental results showed that our ensemble model improved 1.69%p in UAS and 2.17%p in LAS than the same arc-eager approach-based Malt parser.

Design and Implementation of an LLM system to Improve Response Time for SMEs Technology Credit Evaluation

  • Sungwook Yoon
    • International journal of advanced smart convergence
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    • 제12권3호
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    • pp.51-60
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    • 2023
  • This study focuses on the design of a GPT-based system for relatively rapid technology credit assessment of SMEs. This system addresses the limitations of traditional time-consuming evaluation methods and proposes a GPT-based model to comprehensively evaluate the technological capabilities of SMEs. This model fine-tunes the GPT model to perform fast technical credit assessment on SME-specific text data. Also, It presents a system that automates technical credit evaluation of SMEs using GPT and LLM-based chatbot technology. This system relatively shortens the time required for technology credit evaluation of small and medium-sized enterprises compared to existing methods. This model quickly assesses the reliability of the technology in terms of usability of the base model.

작업준비시간이 없는 이종 병렬설비에서 총 소요 시간 최소화를 위한 미미틱 알고리즘 기반 일정계획에 관한 연구 (A Study on Memetic Algorithm-Based Scheduling for Minimizing Makespan in Unrelated Parallel Machines without Setup Time)

  • 이태희;유우식
    • 대한안전경영과학회지
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    • 제25권2호
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    • pp.1-8
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    • 2023
  • This paper is proposing a novel machine scheduling model for the unrelated parallel machine scheduling problem without setup times to minimize the total completion time, also known as "makespan". This problem is a NP-complete problem, and to date, most approaches for real-life situations are based on the operator's experience or simple heuristics. The new model based on the Memetic Algorithm, which was proposed by P. Moscato in 1989, is a hybrid algorithm that includes genetic algorithm and local search optimization. The new model is tested on randomly generated datasets, and is compared to optimal solution, and four scheduling models; three rule-based heuristic algorithms, and a genetic algorithm based scheduling model from literature; the test results show that the new model performed better than scheduling models from literature.

사회적 모델의 실현을 위한 장애정의 고찰: 현행 장애인차별금지법의 장애정의의 수정을 위하여 (Definitions of Disability to Realize Social Model of Disability : A Suggestion for Amendment of the Definition of Disability in Current Act)

  • 남찬섭
    • 한국사회복지학
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    • 제61권2호
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    • pp.161-187
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    • 2009
  • 장애인차별금지법은 사회적 모델을 실현하기 위한 제도적 틀로 간주되지만 사회적 모델은 장애인차별금지법의 제정과 시행으로 자동적으로 실현되는 것은 아니다. 특히 그 중에서도 장애정의는 사회적 모델의 실현에 매우 중요한 의미를 갖는다. 하지만 역설적이게도 사회적 모델이 주장하는 장애정의는 이것이 장애인차별금지법에 반영될 때에는 법률의 작동을 모순에 빠뜨리는 문제점을 안고 있다. 이 글에서는 이 문제점이 어디서 어떻게 발생하는지에 대해 살펴보았으며, 이를 바탕으로 문제해결을 위한 접근을 제시하였다. 문제해결을 위한 접근으로는 현행 장애정의를 유지한 상태에서의 접근과 현행 장애정의를 손상에 중점을 둔 특성중심적 장애정의로 전면 대체하는 접근을 생각할 수 있는데, 전자의 접근도 현실적이고 충분히 고려할 가치가 있으나 문제의 근본적인 해결로는 부족한 것으로 판단되었다. 따라서 현행 장애 정의를 전면 수정하는 후자의 접근이 문제를 근본적으로 해결하고 사회적 모델을 실현하는 데 더 유리한 것으로 판단되었다.

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Vibration Suppression Control for a Twin-Drive Geared Mechanical System with Backlash: Effects of Model-Based Control

  • Itoh, Masahiko
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1392-1397
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    • 2003
  • This paper deals with a control technique of eliminating the transient vibration of a twin-drive geared mechanical system. This technique is based on a model-based control in order to establish the damping effect at the driven machine part. The control model is composed of reduced-order electrical and mechanical parts. This control model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically and it is added to the velocity command to suppress the transient vibration generated at the load. This control technique is applied to a twin-drive geared system with backlash. In the previous work, the performance of this control method is examined by simulations. In this paper, the effectiveness of this control technique is verified by experiments. The settling time of the residual vibration generated at the loading inertia can be shortened down to about 1/2 of the uncompensated vibration level.

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Probabilistic Reliability Based Grid Expansion Planning of Power System Including Wind Turbine Generators

  • Cho, Kyeong-Hee;Park, Jeong-Je;Choi, Jae-Seok
    • Journal of Electrical Engineering and Technology
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    • 제7권5호
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    • pp.698-704
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    • 2012
  • This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

On the Local Identifiability of Load Model Parameters in Measurement-based Approach

  • Choi, Byoung-Kon;Chiang, Hsiao-Dong
    • Journal of Electrical Engineering and Technology
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    • 제4권2호
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    • pp.149-158
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    • 2009
  • It is important to derive reliable parameter values in the measurement-based load model development of electric power systems. However parameter estimation tasks, in practice, often face the parameter identifiability issue; whether or not the model parameters can be estimated with a given input-output data set in reliable manner. This paper introduces concepts and practical definitions of the local identifiability of model parameters. A posteriori local identifiability is defined in the sense of nonlinear least squares. As numerical examples, local identifiability of third-order induction motor (IM) model and a Z-induction motor (Z-IM) model is studied. It is shown that parameter ill-conditioning can significantly affect on reliable parameter estimation task. Numerical studies show that local identifiability can be quite sensitive to input data and a given local solution. Finally, several countermeasures are proposed to overcome ill-conditioning problem in measurement-based load modeling.

국내 아날로그와 디지털 이동전화 서비스 가입자 수 예측을 위한 선택 관점의 대체 확산 모형 (A Choice-Based Substitutive Diffusion Model for Forecasting Analog and Digital Mobile Telecommunication Service Subscribers in Korea)

  • 전덕빈;박윤서;김선경;박명환;박영선
    • 경영과학
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    • 제19권2호
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    • pp.125-137
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    • 2002
  • The telecommunications market is expanding rapidly and becoming more substitutive. In this environment, demand forecasting is very difficult, yet important for both practitioners and researchers. in this paper, we adopt the modeling approach proposed dy Jun and Park [6]. The basic premise is that demand patterns result from choice behavior, where customers choose a product to maximize their utility. We apply a choice-based substitutive diffusion model to the Korean mobile telecommunication service market where digital service has completely replaced analog service. In comparison with Bass-type multigeneration models. our model provides superior fitting and forecasting performance. The choice-based model is useful in that it enables the description of such complicated environments and provides the flexibility to include marketing mix variables such as price and advertising in the regression analysis.