• Title/Summary/Keyword: Bottom-up method

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A Bottom-up and Top-down Based Disparity Computation

  • Kim, Jung-Gu;hong Jeong
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.211-221
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    • 1998
  • It is becoming apparent that stereo matching algorithms need much information from high level cognitive processes. Otherwise, conventional algorithms based on bottom-up control alone are susceptible to local minima. We introduce a system that consists of two levels. A lower level, using a usual matching method, is based upon the local neighborhood and a second level, that can integrate the partial information, is aimed at contextual matching. Conceptually, the introduction of bottom-up and top-down feedback loop to the usual matching algorithm improves the overall performance. For this purpose, we model the image attributes using a Markov random field (MRF) and thereupon derive a maximum a posteriori (MAP) estimate. The energy equation, corresponding to the estimate, efficiently represents the natural constraints such as occlusion and the partial informations from the other levels. In addition to recognition, we derive a training method that can determine the system informations from the other levels. In addition to recognition, we derive a training method that can determine the system parameters automatically. As an experiment, we test the algorithms using random dot stereograms (RDS) as well as natural scenes. It is proven that the overall recognition error is drastically reduced by the introduction of contextual matching.

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Robust Face Detection Based on Knowledge-Directed Specification of Bottom-Up Saliency

  • Lee, Yu-Bu;Lee, Suk-Han
    • ETRI Journal
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    • v.33 no.4
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    • pp.600-610
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    • 2011
  • This paper presents a novel approach to face detection by localizing faces as the goal-specific saliencies in a scene, using the framework of selective visual attention of a human with a particular goal in mind. The proposed approach aims at achieving human-like robustness as well as efficiency in face detection under large scene variations. The key is to establish how the specific knowledge relevant to the goal interacts with the bottom-up process of external visual stimuli for saliency detection. We propose a direct incorporation of the goal-related knowledge into the specification and/or modification of the internal process of a general bottom-up saliency detection framework. More specifically, prior knowledge of the human face, such as its size, skin color, and shape, is directly set to the window size and color signature for computing the center of difference, as well as to modify the importance weight, as a means of transforming into a goal-specific saliency detection. The experimental evaluation shows that the proposed method reaches a detection rate of 93.4% with a false positive rate of 7.1%, indicating the robustness against a wide variation of scale and rotation.

A Study on Bottom-Up Update of TPR-Tree for Target Indexing in Naval Combat Systems (함정전투체계 표적 색인을 위한 TPR-Tree 상향식 갱신 기법)

  • Go, Youngkeun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.2
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    • pp.266-277
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    • 2019
  • In modern warfare, securing time for preemptive response is recognized as an important factor of victory. The naval combat system, the core of naval forces, also strives to increase the effectiveness of engagement by improving its real-time information processing capabilities. As part of that, it is considered to use the TPR-tree in the naval combat system's target indexing because spatio-temporal searches can be performed quickly even as the number of target information increases. However, because the TPR-tree is slow to process updates, there is a limitation to handling frequent updates. In this paper, we present a method for improving the update performance of TPR-tree by applying the bottom-up update scheme, previously proposed for R-tree, to the TPR-tree. In particular, we analyze the causes of overlaps occurring when applying the bottom-up updates and propose ways to limit the MBR expansion to solve it. Our experimental results show that the proposed technique improves the update performance of TPR-tree from 3.5 times to 12 times while maintaining search performance.

Behavior of Soft Ground Throughout Mock-up Test Using Low Self Weight Banking Method (경량성토 모형시험을 통한 연약지반상의 성토제체의 거동)

  • Kim, Sang Chel
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.85-91
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    • 2011
  • This study aims at evaluating feasibility of Bottom ash-mixed Foam Cement Banking(BFCB) Method on the enhancement of soft soil, which is developed to reduce self-weight of banking by applying bottom ash and foam. to cement slurry. In order to measure the behavior of soil when BFCB layer was covered to soft ground, a testing equipment for mock-up test was fabricated and phased loads were applied up to measurement of yielding and ultimate strengths as well as movement of ground particles. In addition, these measured values such as settlement and heaving were compared with ones of surface-hardening method prevailing on soil improvement. As the result through mock-up test, BFCB showed lower values of ground deformation, while wider range of deformation was observed in compare to the other method. And settlement and heaving were measured lower, which implies the method developed is very effective to applicability of soft ground.

Method to Enhance Color Gamut up to 89 % in Bottom Emission Active-Matrix Organic Light Emitting Device

  • Kim, Hwa-Kyung;Choi, Hong-Seok;Yoo, Dong-Hee;Kim, Woo-Chan;Yoon, Jong-Geun;Yang, Joong-Whan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.43-46
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    • 2007
  • Though bottom emission AM-OLED has advantages in respect of mass production, the bottom emission type is underrated due to its low aperture ratio and low color gamut, compared with top emission type. In this paper, we demonstrate that the color gamut up to 89 % can be simply achieved by depositing dielectric multilayers, whose thicknesses are determined using an optical simulation program, prior to formation of Si layer.

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A Study on the Bottom-up Long-run Incremental costing Methodology for the Korean Mobile Network (이동통신망 상호접속요금 산정을 위한 장기증분원가모형에 관한 연구)

  • Choe Seon-Mi;Hyeon Chang-Hui
    • Proceedings of the Korea Technology Innovation Society Conference
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    • 2004.05a
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    • pp.25-36
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    • 2004
  • The key objective of this paper is to suggest a pilot model for mobile network interconnection charge calculation by bottom-up long-run incremental costing methodology. Interconnection issues have lately attracted considerable attention by network operators and regulators. However there is no standard by all the network operators' agreement. The costing method is an acute problem because the interconnection charge is directly related to the network operators' revenue. Thus Korea has planned to launch the new interconnection policy based on the current traffic distribution and then we simulate the model in a sample area with virtual data. The results propose objective and reasonable guideline for the mobile network element cost calculation. It can be helpful for calculating price floor or bottom-up long run incremental interconnection charge by regulator.

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Linear Feature Extraction from Satellite Imagery using Discontinuity-Based Segmentation Algorithm

  • Niaraki, Abolghasem Sadeghi;Kim, Kye-Hyun;Shojaei, Asghar
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.643-646
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    • 2006
  • This paper addresses the approach to extract linear features from satellite imagery using an efficient segmentation method. The extraction of linear features from satellite images has been the main concern of many scientists. There is a need to develop a more capable and cost effective method for the Iranian map revision tasks. The conventional approaches for producing, maintaining, and updating GIS map are time consuming and costly process. Hence, this research is intended to investigate how to obtain linear features from SPOT satellite imagery. This was accomplished using a discontinuity-based segmentation technique that encompasses four stages: low level bottom-up, middle level bottom-up, edge thinning and accuracy assessment. The first step is geometric correction and noise removal using suitable operator. The second step includes choosing the appropriate edge detection method, finding its proper threshold and designing the built-up image. The next step is implementing edge thinning method using mathematical morphology technique. Lastly, the geometric accuracy assessment task for feature extraction as well as an assessment for the built-up result has been carried out. Overall, this approach has been applied successfully for linear feature extraction from SPOT image.

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EFFICIENT MARKER EXTRACTION ALGORITHM FOR INITIAL SEGMENTATION IN A BOTTOM-UP IMAGE SEGMENTATION SCHEME (상향식 영상분할 구조에서의 초기 영상분할을 위한 효율적인 마커 추출 알고리즘)

  • 박현상;나종범
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.895-898
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    • 1998
  • In this paper, we propose an efficient marker extraction algorithm for initial image segmentation in a bottom-up segmentation scheme. The proposed algorithm generates dense markers in visually complex areas and coarse markers in visually uniform areas. which conforms to the human perceptual system. Experimental results show that the proposed method achieves better subjective quality for fine initial image segmentation.

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Analysis of the Behaviors of Continuous parts in Continuous PSC Girders Bridges (PSC 연속 거더교의 연속화부 거동에 관한 해석적 연구)

  • 구민서;김훈희;정영도
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.404-411
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    • 2002
  • The PSC 2-span-continuous-bridge by Up-Down Method on construction process is used for this research. It is measured the strain of lower-steel-plate at continuous section on the active range of negative moment at the stage of introducing compressive stress to bottom-plate and compared with results of structural analysis. On the basis of these results, it is confirmed the introduced compressive stress tか bottom-plate. The object of this research is presenting the degree of continuity at the stage of lifting up process.

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Study on Fabricating Bead Mill for Manufacturing Nano Powders (나노 파우더 제조용 비드밀 제작에 관한 연구)

  • Son, Jae-Yub;Nam, Kwon-Sun;Kim, Byeong-Hee
    • Journal of Industrial Technology
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    • v.25 no.B
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    • pp.127-133
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    • 2005
  • Manufacturing methods of Nano particles can be distinguished by top-down technology as physical method and bottom-up technology as chemical synthetic method. Top-down technology is a kind of method for making microstructure as like carving after forming a macroscopic structure in advance and its typical methods are ball milling, gas condensation method and so on. Nano Particles synthesized by bottom-up method have got to do dispersing process for using them as actual nano particles because their viscosity are very strong and so easy to shape cohesive substances. Therefore, this study is about a particle separating device which separates a certain constant size of grains processed already in mill and mixer because we mostly use media agitating mill as a device of milling and dispersing and we necessarily use very slight balls as media for manufacturing nano particles in the machine. The centrifugal device has been designed for passing and separating below a certain type of grain size after final process of particles in the mill.

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