• Title/Summary/Keyword: Uncertain Boundaries

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Nonlinear deflection responses of layered composite structure using uncertain fuzzified elastic properties

  • Patle, B.K.;Hirwani, Chetan K.;Panda, Subrata Kumar;Katariya, Pankaj V.;Dewangan, Hukum Chand;Sharma, Nitin
    • Steel and Composite Structures
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    • v.35 no.6
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    • pp.753-763
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    • 2020
  • In this article, the influence of fuzzified uncertain composite elastic properties on non-linear deformation behaviour of the composite structure is investigated under external mechanical loadings (uniform and sinusoidal distributed loading) including the different end boundaries. In this regard, the composite model has been derived considering the fuzzified elastic properties (through a triangular fuzzy function, α cut) and the large geometrical distortion (Green-Lagrange strain) in the framework of the higher-order mid-plane kinematics. The results are obtained using the fuzzified nonlinear finite element model via in-house developed computer code (MATLAB). Initially, the model accuracy has been established and explored later to show the dominating elastic parameter affect the deflection due to the inclusion of fuzzified properties by solving a set of new numerical examples.

Detecting Uncertain Boundary Algorithm using Constrained Delaunay Triangulation (제한된 델로네 삼각분할을 이용한 공간 불확실한 영역 탐색 기법)

  • Cho, Sunghwan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.2
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    • pp.87-93
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    • 2014
  • Cadastral parcel objects as polygons are fundamental dataset which represent land administration and management of the real world. Thus it is necessary to assure topological seamlessness of cadastral datasets which means no overlaps or gaps between adjacent parcels. However, the problem of overlaps or gaps are frequently found due to non-coinciding edges between adjacent parcels. These erroneous edges are called uncertain edges, and polygons containing at least one uncertain edge are called uncertain polygons. In this paper, we proposed a new algorithm to efficiently search parcels of uncertain polygons between two adjacent cadastral datasets. The algorithm first selects points and polylines around adjacent datasets. Then the Constrained Delaunay Triangulation (CDT) is applied to extract triangles. These triangles are tagged by the number of the original cadastral datasets which intersected with the triangles. If the tagging value is zero, the area of triangles mean gaps, meanwhile, the value is two, the area means overlaps. Merging these triangles with the same tagging values according to adjacency analysis, uncertain edges and uncertain polygons could be found. We have performed experimental application of this automated derivation of partitioned boundary from a real land-cadastral dataset.

Extracting The Prostate Boundary Using Direction Features of Prostate Boundary On Ultrasound Prostate Image

  • Park, Jae Heung;Seo, Yeong Geon
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.11
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    • pp.103-111
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    • 2016
  • Traditionally, in the hospital the doctors saw the TRUS images by their eyes and manually segmented the boundary between the prostate and nonprostate. But the manually segmenting process not only needed too much time but also had different boundaries according to the doctor. To cope the problems, some automatic segmentations of the prostate have been studied to generate the constant segmentation results and get the belief from patients. Besides, on detecting the boundary, the ones in the middle of all images are easy to find the boundary but the base and apex of the images are hard to do it since there are lots of uncertain boundary. Accurate detection of prostate boundaries is a challenging and difficult task due to weak prostate boundaries, speckle noises and the short range of gray levels. In this paper, we propose the method that extracts a prostate boundary using features of its directions on prostate image. As a result of our experiments, it shows that the boundary never falls short of the existing methods or human expert's segmentation. And also, its searching speed is too fast because the method searches a smaller area that other methods.

Physics-based modelling and validation of inter-granular helium behaviour in SCIANTIX

  • Giorgi, R.;Cechet, A.;Cognini, L.;Magni, A.;Pizzocri, D.;Zullo, G.;Schubert, A.;Van Uffelen, P.;Luzzi, L.
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2367-2375
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    • 2022
  • In this work, we propose a new mechanistic model for the treatment of helium behaviour at the grain boundaries in oxide nuclear fuel. The model provides a rate-theory description of helium inter-granular behaviour, considering diffusion towards grain edges, trapping in lenticular bubbles, and thermal resolution. It is paired with a rate-theory description of helium intra-granular behaviour that includes diffusion towards grain boundaries, trapping in spherical bubbles, and thermal re-solution. The proposed model has been implemented in the meso-scale software designed for coupling with fuel performance codes SCIANTIX. It is validated against thermal desorption experiments performed on doped UO2 samples annealed at different temperatures. The overall agreement of the new model with the experimental data is improved, both in terms of integral helium release and of the helium release rate. By considering the contribution of helium at the grain boundaries in the new model, it is possible to represent the kinetics of helium release rate at high temperature. Given the uncertainties involved in the initial conditions for the inter-granular part of the model and the uncertainties associated to some model parameters for which limited lower-length scale information is available, such as the helium diffusivity at the grain boundaries, the results are complemented by a dedicated uncertainty analysis. This assessment demonstrates that the initial conditions, chosen in a reasonable range, have limited impact on the results, and confirms that it is possible to achieve satisfying results using sound values for the uncertain physical parameters.

Cluster or Diversify? A Dilemma for Sustainable Local Techno-Economic Development

  • Phillips, Fred;Oh, Deog-Seong;Lee, Eung-Hyun
    • World Technopolis Review
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    • v.5 no.2
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    • pp.98-107
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    • 2016
  • By highlighting the efficiencies gained from regional specialization, the cluster concept has distracted economic development officials from their traditional role of diversifying regional and local economies. Clustering was a viable strategy for much of the 18 years following its original appearance in the literature. Now, two events cast doubt on the continued viability of cluster-based specialization. First, the digital convergence has blurred the boundaries that once separated one industry from another. An industry cluster strategy becomes difficult when the industry cannot be defined. Second, many cluster initiatives fail. Combining literature search with the system-theoretic notions of efficiency and redundancy, we find many factors moderate cluster success. This implies regions facing uncertain success in their cluster-building efforts should thoroughly understand their unique circumstances and build upon them. Regions with successful clusters are advised to aim for multiple related clusters or superclusters.

Construction of Allowable Load Set for Multi-body Systems and Application Cases (다물체 시스템에서의 허용하중 집합의 구현과 적용)

  • Kim, J.H.;Kwak, B.M.
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.758-763
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    • 2001
  • A concept called Allowable Load Set (ALS) is introduced and methods of finding its boundaries are developed. The resulting diagram allows an easy understanding of load and strength characteristics of a structure in relation to structural integrity under uncertain loading conditions. An allowable load diagram for an ALS visualizes the relation between a prescribed load and a degree of safety of the structure. During the application of the algorithms, critical areas of the structure are identified. A systematic method of finding the allowable load sets for multi-body mechanical systems is especially presented and applied to an excavator as a realistic case.

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Obstacle Avoidance using Power Potential Field for Stereo Vision based Mobile Robot (PPF를 이용한 4족 로봇의 장애물 회피)

  • 조경수;김동진;기창두
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.554-557
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    • 2002
  • This paper describes power potential field method for the collision-free path planning of stereo-vision based mobile robot. Area based stereo matching is performed for obstacle detection in uncertain environment. The repulsive potential is constructed by distributing source points discretely and evenly on the boundaries of obstacles and superposing the power potential which is defined so that the source potential will have more influence on the robot than the sink potential when the robot is near to source point. The mobile robot approaches the goal point by moving the robot directly in negative gradient direction of the main potential. We have investigated the possibility of power potential method for the collision-free path planning of mobile robot through various experiments.

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Using Fuzzy Logic for Event Detection in Soccer Video

  • Thanh Nguyen Ngoc;Giao Le Ngoc
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.119-121
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    • 2004
  • Video event detection has become an essential application in multimedia computing. For sports video, salient events are usually detected by analyzing video sequence by specific decision rules. However in many kinds of sports video (e.g. soccer), the game contains continuous actions, in which the boundaries of shots, scenes are uncertain. So the conventional analyzing methods using crisp decisions are not efficient. Fuzzy logic is a natural approach that can tackle this problem. In this paper, we present a new approach using fuzzy technique for event detection in soccer video. The experiment shows encouraging results for this method

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Protocol for testing of cold-formed steel wall in regions of low-moderate seismicity

  • Shahi, Rojit;Lam, Nelson;Gad, Emad;Wilson, John
    • Earthquakes and Structures
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    • v.4 no.6
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    • pp.629-647
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    • 2013
  • Loading protocols have been developed for quasi-static cyclic testing of structures and components. However, it is uncertain if protocols developed for conditions of intense ground shaking in regions of high seismicity would also be applicable to regions of low-moderate seismicity that are remote from the tectonic plate boundaries. This study presents a methodology for developing a quasi-static cyclic displacement loading protocol for experimental bracing evaluation of cold-formed steel stud shear walls. Simulations presented in the paper were based on conditions of moderate ground shaking (in Australia). The methodologies presented are generic in nature and can be applied to other regions of similar seismicity conditions (which include many parts of China, Korea, India and Malaysia). Numerous response time histories including both linear and nonlinear analyses have been generated for selected earthquake scenarios and site classes. Rain-flow cycle counting method has been used for determining the number of cycles at various ranges of normalized displacement amplitude. It is found that the number of displacement cycles of the loading protocol increases with increasing intensity of ground shaking (associated with a longer return period).

Delineating the Prostate Boundary on TRUS Image Using Predicting the Texture Features and its Boundary Distribution (TRUS 영상에서 질감 특징 예측과 경계 분포를 이용한 전립선 경계 분할)

  • Park, Sunhwa;Kim, Hoyong;Seo, Yeong Geon
    • Journal of Digital Contents Society
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    • v.17 no.6
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    • pp.603-611
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    • 2016
  • Generally, the doctors manually delineated the prostate boundary seeing the image by their eyes, but the manual method not only needed quite much time but also had different boundaries depending on doctors. To reduce the effort like them the automatic delineating methods are needed, but detecting the boundary is hard to do since there are lots of uncertain textures or speckle noises. There have been studied in SVM, SIFT, Gabor texture filter, snake-like contour, and average-shape model methods. Besides, there were lots of studies about 2 and 3 dimension images and CT and MRI. But no studies have been developed superior to human experts and they need additional studies. For this, this paper proposes a method that delineates the boundary predicting its texture features and its average distribution on the prostate image. As result, we got the similar boundary as the method of human experts.