• 제목/요약/키워드: model tree technique

검색결과 199건 처리시간 0.03초

컴퓨터 그래픽스를 활용한 조경수목 형상자료의 가시화 - AccuRender의 수목 모델링 모듈 활용을 중심으로 - (Visualization of Landscape Tree Forms Using Computer Graphic Techniques: Using the Plant Editing Module in AccuRender)

  • 박시훈;조동범
    • 한국조경학회지
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    • 제27권4호
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    • pp.143-150
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    • 1999
  • The purpose of this research is to find som ways to model tree forms more efficiently in reference with surveying structural data and handling parameters in plant Editor of AccuRender, the AutoCAD-based rendering software adopting the procedural plant modeling technique. In case of modelling a new tree, because it is efficient to modify an existing tree data as a template, we attempted to classify 81 species' data from existing plant library including conifers and deciduous tree. According to the qualitative characteristics and quantitative parameters of geometrical and branching structure, 8 types of tree form were classified with factor and cluster analysis. Some critical aspects found in the distributions of standardized scores of parameters in each type were discussed for explaining the tree forms intuitively. For adaptability of the resulted classification and typical parameters, 10 species of tree were measured and modelled, and proved to be very similar to the real structures of tree forms. CG or CAD-based plant modelling technique would be recommended not only as a presentation tool but for planting design, landscape simulation and assessment.

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분산형 데이터마이닝 구현을 위한 의사결정나무 모델 전송 기술 (The Transfer Technique among Decision Tree Models for Distributed Data Mining)

  • 김충곤;우정근;백성욱
    • 디지털콘텐츠학회 논문지
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    • 제8권3호
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    • pp.309-314
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    • 2007
  • 분산형 데이터마이닝을 위해 의사결정나무 알고리즘은 분산형 협업 환경에 적합하도록 변환되어야 한다. 본 논문에서 제시된 분산형 데이터마이닝 시스템은 각각의 사이트에서 부분적인 데이터를 위한 데이터마이닝 작업을 수행할 수 있는 에이전트와 여러 에이전트들의 협업을 통해 최종적인 의사결정나무 모델을 완성할 수 있도록 에이전트들 간의 통신을 중재하는 미디에이터로 구성되어 있다. 분산형 데이터마이닝의 장점 중에 하나는 여러 사이트에 분산되어 있는 대량의 데이터를 분산 처리하므로 데이터마이닝의 소요시간을 현저하게 줄일 수 있다는 점이다. 그러나 각 사이트들에 존재하고 있는 에이전트들 간의 통신에 부하가 과도하게 걸린다면, 효율적인 시스템으로의 활용도가 낮아질 것 이다. 본 논문은 에이전트들 간에 의사결정나무 모델의 전송량을 최소로 할 수 있는 방법론에 초점을 맞추었다.

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Multicast Tree Generation using Meta Reinforcement Learning in SDN-based Smart Network Platforms

  • Chae, Jihun;Kim, Namgi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권9호
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    • pp.3138-3150
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    • 2021
  • Multimedia services on the Internet are continuously increasing. Accordingly, the demand for a technology for efficiently delivering multimedia traffic is also constantly increasing. The multicast technique, that delivers the same content to several destinations, is constantly being developed. This technique delivers a content from a source to all destinations through the multicast tree. The multicast tree with low cost increases the utilization of network resources. However, the finding of the optimal multicast tree that has the minimum link costs is very difficult and its calculation complexity is the same as the complexity of the Steiner tree calculation which is NP-complete. Therefore, we need an effective way to obtain a multicast tree with low cost and less calculation time on SDN-based smart network platforms. In this paper, we propose a new multicast tree generation algorithm which produces a multicast tree using an agent trained by model-based meta reinforcement learning. Experiments verified that the proposed algorithm generated multicast trees in less time compared with existing approximation algorithms. It produced multicast trees with low cost in a dynamic network environment compared with the previous DQN-based algorithm.

시뮬레이션을 이용한 통합전력시스템의 위험도 분석 (Simulation-Based Risk Analysis of Integrated Power System)

  • 이지영;한영진;윤원영;빈재구
    • 대한산업공학회지
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    • 제42권2호
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    • pp.151-164
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    • 2016
  • In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

A New Distance Measure for a Variable-Sized Acoustic Model Based on MDL Technique

  • Cho, Hoon-Young;Kim, Sang-Hun
    • ETRI Journal
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    • 제32권5호
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    • pp.795-800
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    • 2010
  • Embedding a large vocabulary speech recognition system in mobile devices requires a reduced acoustic model obtained by eliminating redundant model parameters. In conventional optimization methods based on the minimum description length (MDL) criterion, a binary Gaussian tree is built at each state of a hidden Markov model by iteratively finding and merging similar mixture components. An optimal subset of the tree nodes is then selected to generate a downsized acoustic model. To obtain a better binary Gaussian tree by improving the process of finding the most similar Gaussian components, this paper proposes a new distance measure that exploits the difference in likelihood values for cases before and after two components are combined. The mixture weight of Gaussian components is also introduced in the component merging step. Experimental results show that the proposed method outperforms MDL-based optimization using either a Kullback-Leibler (KL) divergence or weighted KL divergence measure. The proposed method could also reduce the acoustic model size by 50% with less than a 1.5% increase in error rate compared to a baseline system.

버퍼를 장착한 a$\times$b 스위치로 구성된 Fat-tree 망의 성능분석 (Analytical modeling of a Fat-tree Network with buffered a$\times$b switches)

  • 신태지;양명국
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.374-377
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    • 2003
  • In this paper, a performance evaluation model of the Fat-Tree network with the multiple-buffered crossbar switches is proposed and examined. Buffered switch technique is well known to solve the data collision problem in the switch network The proposed evaluation model is developed by investigating the transfer patterns of data packets in a switch with output-buffers. Steady state probability concept is used to simplify the analyzing processes. Two important parameters of the network performance, throughput and delay, are then evaluated. To validate the proposed analysis model, the simulation is carried out on the various sizes of Fat-tree networks that use the multiple a$\times$b buffered crossbar switches. It is observed that both analysis and simulation results are match closely.

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인공지능을 이용한 급성 뇌졸중 환자의 재원일수 예측모형 개발 (Development of Predictive Model for Length of Stay(LOS) in Acute Stroke Patients using Artificial Intelligence)

  • 최병관;함승우;김촉환;서정숙;박명화;강성홍
    • 디지털융복합연구
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    • 제16권1호
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    • pp.231-242
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    • 2018
  • 병원 재원일수의 효율적 관리는 병원의 수익과 환자의 진료비 절감을 위해 매우 중요한 요소이다. 이러한 재원일수의 효율적 관리를 위해서는 병원들이 재원일수에 대해서 벤치마킹을 할 수 있도록 지원이 필요하고 재원일수 절감의 구체적인 방향을 제시해 줄 수 있는 재원일수 예측모형의 개발이 필요하다. 본 연구에서는 2013년과 2014년도 퇴원손상환자자료 중 급성뇌졸중 환자를 추출하여 분석용 자료를 만들고 인공지능을 이용하여 급성뇌졸중 환자의 재원일수 예측모형을 개발하였다. 분석용 자료는 훈련용 60%, 평가용 40%로 분류하였다. 모형개발은 전통적 통계기법인 다중회귀분석기법과 인공지능기법인 대화식 의사결정나무기법, 신경망 기법, 그리고 이들을 모두 통합한 앙상블기법을 이용하였다. 모형평가는 Root ASE(Absolute error) 지표를 이용하였는데, 다중회귀분석은 23.7, 대화식결정나무 23.7, 신경망 분석은 22.7, 앙상블은 22.7로 나타났고 이를 통하여 재원일수 예측모형 개발에 인공지능기법의 유용성이 입증되었다. 앞으로 재원일수 예측모형개발에 인공지능 기법을 보다 효율적으로 활용할 수 있는 방안에 대해서 계속적인 연구가 이루어 질 필요가 있다.

상태 전이 모델 기반 결함 트리 분석 (Fault Tree Analysis based on State-Transition Model)

  • 정인상
    • 한국콘텐츠학회논문지
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    • 제11권10호
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    • pp.49-58
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    • 2011
  • 결함 트리 분석(Fault Tree Analysis)은 결함 트리를 구축하여 시스템의 안전성 분석을 수행한다. 그러나 결함 트리를 구성하는 작업은 대상 시스템의 도메인에 대한 지식과 경험을 필요로 하며 많은 시간과 노력을 소요한다. 이 논문에서는 시스템 설계 산출물인 상태 전이 모델을 기반으로 결함 트리를 체계적으로 구성하는 방법을 제안한다. 이를 위해 시스템 상태 전이 모델의 안정성 확보에 필요한 조건들을 식별하고 결함 트리를 구성할 수 있는 템플리트를 개발한다. 이 논문에서는 제안된 방법을 철도 건널목 제어 시스템에 적용한 결과도 기술한다.

동적 결함 트리 (Dynamic Fault Tree) 알고리즘을 이용한 시스템의 신뢰도 평가에 관한 연구 (A Study on System's Reliability Evaluation Using DFT Algorithm)

  • 김진수;양성현;이기서
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1998년도 추계학술대회 논문집
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    • pp.280-287
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    • 1998
  • In this paper, Dynamic Fault Tree algorithm(DFT algorithm) is presented. This new algorithm provides a concise representation of dynamic fault tolerance system structure with redundancy, dynamic redundancy management and complex fault & error recovery techniques. And it allows the modeler to define a dynamic fault tree model with the relative advantages of both fault tree and Markov models that captures the system structure and dynamic behavior. This algorithm applies to TMR and Dual-Duplex systems with the dynamic behavior and show that this algorithm captured the dynamic behavior in these systems with fault & error recovery technique, sequence-dependent failures and the use dynamic spare. The DFT algorithm for solving the problems of the systems is more effective than the Markov and Fault tree analysis model.

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철도사상 사고위험도 평가 모델 개발에 관한 연구 (Development of Risk Evaluation Models for Railway Casualty Accidents)

  • 박찬우;김민수;왕종배;최돈범
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1499-1504
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    • 2008
  • This study shows risk-based evaluation results of casualty accidents for passengers, railway staffs and MOP(Member of public) on the national railway in South Korea. To evaluate risk of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. A probability evaluation model for each hazardous event which was based on the accident appearance scenario was developed by using the Fault Tree Analysis (FTA) technique. The probability for each hazardous event was evaluated from the historical data and structured expert judgment. In addition, the severity assessment model utilized by the Event Tree Analysis (ETA) technique was composed of the accident progress scenarios. And the severity for the hazardous events was estimated using fatalities and weighted injuries. The risk assessment model developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.

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