• 제목/요약/키워드: 증분성

Search Result 189, Processing Time 0.028 seconds

On the Study of System Reliability Analysis of Tension Leg Platforms (TLP 해양구조물의 시스템 신뢰성 해석에 관한 연구)

  • Joo-Sung,Lee
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.27 no.2
    • /
    • pp.55-62
    • /
    • 1990
  • In this paper, another method for system reliability analysis, called the extended incremental load method, is introduced. The method is an extension of the conventional incremental load method and has been developed aiming at evaluating the probability of system failure(or system reliability) of continuous structures such as floating offshore structures under the multiple loading condition, more realistically considering the post-ultimate behaviour of failed components and directly using the strength formulae of principle components in a structure with employing the modified safety margin equation proposed herein in the system analysis. The method has been applied to the Hutton TLP operated in the Hutton field in the North Sea and a certain variant of the design using the TLP Rule Case Committee type improved strength models. System failure probability and corresponding system reliability indices are derived for a more economical and efficient design. The redundancy characteristics are also addressed. The TLP forms are shown to possess high reserve strength and system safety.

  • PDF

Intermediate Depth Image Generation using Disparity Increment of Stereo Depth Images (스테레오 깊이영상의 변위증분을 이용한 중간시점 깊이영상 생성)

  • Koo, Ja-Myung;Seo, Young-Ho;Choi, Hyun-Jun;Yoo, Ji-Sang;Kim, Dong-Wook
    • Journal of Broadcast Engineering
    • /
    • v.17 no.2
    • /
    • pp.363-373
    • /
    • 2012
  • This paper proposes a method to generate a depth image at an arbitrary intermediate view-point, which is targeting a video service for free-view, auto-stereoscopy, holography, etc. It assumes that the leftmost and the rightmost depth images are given and they both have been camera-calibrated and image-rectified. This method calculates and uses a disparity increment per depth value. In this paper, it is obtained by stereo matching for the given two depth image by considering more general cases. The disparity increment is used to find the location in the intermediate view-point depth image (IVPD) for each depth in the given images. Thus, this paper finds two IVPDs, from left image and from right image. Noises are removed and holes are filled in each IVPDs and the two results are combined to get the final IVPD. The proposed method was implemented and applied to several test sequences. The results revealed that the quality of the generated IVPD corresponds to 33.84dB of PSNR in average and it takes about 1 second to generate a HD IVPD. We evaluate that this image quality is quite good by considering the low correspondency among the left images, intermediate images, and the right images in the test sequences. If the execution speed is improved, the proposed method can be a very useful method to generate an IVPD at an arbitrary view-point, we believe.

Design of Digit Recognition System Realized with the Aid of Fuzzy RBFNNs and Incremental-PCA (퍼지 RBFNNs와 증분형 주성분 분석법으로 실현된 숫자 인식 시스템의 설계)

  • Kim, Bong-Youn;Oh, Sung-Kwun;Kim, Jin-Yul
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.26 no.1
    • /
    • pp.56-63
    • /
    • 2016
  • In this study, we introduce a design of Fuzzy RBFNNs-based digit recognition system using the incremental-PCA in order to recognize the handwritten digits. The Principal Component Analysis (PCA) is a widely-adopted dimensional reduction algorithm, but it needs high computing overhead for feature extraction in case of using high dimensional images or a large amount of training data. To alleviate such problem, the incremental-PCA is proposed for the computationally efficient processing as well as the incremental learning of high dimensional data in the feature extraction stage. The architecture of Fuzzy Radial Basis Function Neural Networks (RBFNN) consists of three functional modules such as condition, conclusion, and inference part. In the condition part, the input space is partitioned with the use of fuzzy clustering realized by means of the Fuzzy C-Means (FCM) algorithm. Also, it is used instead of gaussian function to consider the characteristic of input data. In the conclusion part, connection weights are used as the extended diverse types in polynomial expression such as constant, linear, quadratic and modified quadratic. Experimental results conducted on the benchmarking MNIST handwritten digit database demonstrate the effectiveness and efficiency of the proposed digit recognition system when compared with other studies.

Comparison of Approximate Nonlinear Methods for Incremental Dynamic Analysis of Seismic Performance (내진성능의 증분동적해석을 위한 비선형 약산법의 비교 검토)

  • Bae, Kyeong-Geun;Yu, Myeong-Hwa;Kang, Pyeong-Doo;Kim, Jae-Ung
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.12 no.1
    • /
    • pp.79-87
    • /
    • 2008
  • Seismic performance evaluation of structure requires an estimation of the structural performance in terms of displacement demand imposed by earthquakes on the structure. Incremental Dynamic Analysis(IDA) is a analysis method that has recently emerged to estimate structural performance under earthquakes. This method can obtained the entire range of structural performance from the linear elastic stage to yielding and finally collapse by subjecting the structure to increasing levels of ground acceleration. Most structures are expected to deform beyond the limit of linearly elastic behavior when subjected to strong ground motion. The nonlinear response history analysis(NRHA) among various nonlinear analysis methods is the most accurate to compute seismic performance of structures, but it is time-consuming and necessitate more efforts. The nonlinear approximate methods, which is more practical and reliable tools for predicting seismic behavior of structures, are extensively studied. The uncoupled modal response history analysis(UMRHA) is a method which can find the nonlinear reponse of the structures for ESDF from the pushover curve using NRHA or response spectrum. The direct spectrum analysis(DSA) is approximate nonlinear method to evaluate nonlinear response of structures, without iterative computations, given by the structural linear vibration period and yield strength from the pushover analysis. In this study, the practicality and the reliability of seismic performance of approximate nonlinear methods for incremental dynamic analysis of mixed building structures are to be compared.

Novel 2-D FDTD Scheme with Isotropic Dispersion and Enhanced Stability (등방성 분산 특성과 개선된 시간 증분을 가지는 2차원 시간 영역 유한 차분법)

  • Koh Il-Suek;Kim Hyun;Yook Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.17 no.2 s.105
    • /
    • pp.165-170
    • /
    • 2006
  • A two dimensional(2-D) finite-difference time-domain(FDTD) method based on a novel finite difference scheme is developed to eliminate the numerical dispersion errors. In this paper, numerical dispersion and stability analysis of the new scheme are given, which show that the proposed method is nearly dispersionless, and stable for a larger time step than the standard FDTD method.

Redesigning of Island LRIC Model in Japan Telecommunication Network (LRIC방식을 도입한 일본의 도서통신 재설계 모형)

  • 김병관;민대홍
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.6 no.7
    • /
    • pp.1001-1005
    • /
    • 2002
  • In march 2002, Study Group on Long-Run Incremental Cost(LRIC) Model of Japan compiled its report. In this report shows there are three ways of inter-islands and island to land telecommunication service, radio communication, suboptic, communication satellite. Analysis of Japanese island network model is helpful in developing Korean island network model. The development of Korean island network model will make he useful costing of local loop unbundling, universal service fund and access charge.

Network Costing Model Alternatives for Reasonable Interconnection Charging Between Networks (합리적 접속료산정을 위한 통신망비용모형 수립방안)

  • 권수천
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.4 no.5
    • /
    • pp.907-917
    • /
    • 2000
  • In this paper the network costing model alternatives for reasonable interconnection charging are suggested. The current interconnection charge regimes is based on fully distributed costing method. Basically this method doesn't consider the common carrier's efficient network cost because it reflects the actual cost of network In this paper, 1 suggest the basic structure of the network costing model fur applications of incremental costing method that considers the efficient cost based on economics-prospective. And I classify network cost with capital cost and operating cost and analysis their reasonable costing methods.

  • PDF

Fragility Analysis of Staggered Wall Structures (격간벽 구조의 취약도 해석)

  • Beak, Donggirl;Kwon, Kwangho;Kim, Jinkoo
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.25 no.5
    • /
    • pp.397-404
    • /
    • 2012
  • Fragility curves show the probability of a system reaching a limit state as a function of some measure of seismic intensity. To obtain fragility curves of six and twelve story staggered wall structures with middle corridor, incremental dynamic analyses were carried out using twenty two pairs of earthquake records, and their failure probabilities for various intensity of seismic load were investigated. The performances of staggered wall structures with added columns along the central corridor and the structures with their first story walls replaced by columns were compared with those of the regular staggered wall structures. Based on the analysis results it was concluded that staggered wall structures with central columns have the largest safety margin for the same level of seismic load.

Redesignig of Island LRIC Model in Japan Telecommunication Network (LRIC방식을 도입한 일본의 도서통신 재설계 모형)

  • 김병관;민대홍
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2002.11a
    • /
    • pp.924-927
    • /
    • 2002
  • In (equation omitted) 2002, Study Croup on Long-Run Incremental Cost(LRIC) Model of Japan compiled its report. In this (equation omitted) shows there are three ways of inter-islands and island to land telecommunication service, radio communication, suboptical, communication satellite. Analysis of Japanese island network model is helpful in developing Korean island network model. The development of Korean island network model will make use of local loop unbundling, universal service fund and access charge.

  • PDF

Thermal load analysis in an incompressible linear visco-elastic cylinder bonded to an elastic shell (非壓縮 粘彈性 圓筒體의 熱荷重 解析)

  • 이영신;최용규
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.11 no.2
    • /
    • pp.205-213
    • /
    • 1987
  • A linear thermoviscoelastic material model, whose basis is on incremental constitutive equation that takes complete strain and temperature histories into account, is derived and computerized in the finite element code. The thermoviscoelastic F.E.M. code which is intended primarily to analyze the cylinder model during the cool-down period, embodies the assumption of linearly elastic bulk and visco-elastic shear responses, thermo-rheologically simple response to temperature change and isotropic thermal expansion. The verification of computer program is accomplished by first testing it against a closed form solution of A.M. Freudenthal & M. Shinozuka's. The stress and strain analyses of five cylindrical models are presented and compared with experimental results. Analytical results are good agreement with experimental results. Margins of safety are evaluated and its allowable ranges are presented.