• Title/Summary/Keyword: Transform-Space View

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Spatial Join based on the Transform-Space View (변환공간 뷰를 기반으로한 공간 조인)

  • 이민재;한욱신;황규영
    • Journal of KIISE:Databases
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    • v.30 no.5
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    • pp.438-450
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    • 2003
  • Spatial joins find pairs of objects that overlap with each other. In spatial joins using indexes, original-space indexes such as the R-tree are widely used. An original-space index is the one that indexes objects as represented in the original space. Since original-space indexes deal with sizes of objects, it is difficult to develop a formal algorithm without relying on heuristics. On the other hand, transform-space indexes, which transform objects in the original space into points in the transform space and index them, deal only with points but no sites. Thus, spatial join algorithms using these indexes are relatively simple and can be formally developed. However, the disadvantage of transform-space join algorithms is that they cannot be applied to original-space indexes such as the R-tree containing original-space objects. In this paper, we present a novel mechanism for achieving the best of these two types of algorithms. Specifically, we propose a new notion of the transform-space view and present the transform-space view join algorithm(TSVJ). A transform-space view is a virtual transform-space index based on an original-space index. It allows us to interpret on-the-fly a pre-built original-space index as a transform-space index without incurring any overhead and without actually modifying the structure of the original-space index or changing object representation. The experimental result shows that, compared to existing spatial join algorithms that use R-trees in the original space, the TSVJ improves the number of disk accesses by up to 43.1% The most important contribution of this paper is to show that we can use original-space indexes, such as the R-tree, in the transform space by interpreting them through the notion of the transform-space view. We believe that this new notion provides a framework for developing various new spatial query processing algorithms in the transform space.

Adaptive Row Major Order: a Performance Optimization Method of the Transform-space View Join (적응형 행 기준 순서: 변환공간 뷰 조인의 성능 최적화 방법)

  • Lee Min-Jae;Han Wook-Shin;Whang Kyu-Young
    • Journal of KIISE:Databases
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    • v.32 no.4
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    • pp.345-361
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    • 2005
  • A transform-space index indexes objects represented as points in the transform space An advantage of a transform-space index is that optimization of join algorithms using these indexes becomes relatively simple. However, the disadvantage is that these algorithms cannot be applied to original-space indexes such as the R-tree. As a way of overcoming this disadvantages, the authors earlier proposed the transform-space view join algorithm that joins two original- space indexes in the transform space through the notion of the transform-space view. A transform-space view is a virtual transform-space index that allows us to perform join in the transform space using original-space indexes. In a transform-space view join algorithm, the order of accessing disk pages -for which various space filling curves could be used -makes a significant impact on the performance of joins. In this paper, we Propose a new space filling curve called the adaptive row major order (ARM order). The ARM order adaptively controls the order of accessing pages and significantly reduces the one-pass buffer size (the minimum buffer size required for guaranteeing one disk access per page) and the number of disk accesses for a given buffer size. Through analysis and experiments, we verify the excellence of the ARM order when used with the transform-space view join. The transform-space view join with the ARM order always outperforms existing ones in terms of both measures used: the one-pass buffer size and the number of disk accesses for a given buffer size. Compared to other conventional space filling curves used with the transform-space view join, it reduces the one-pass buffer size by up to 21.3 times and the number of disk accesses by up to $74.6\%$. In addition, compared to existing spatial join algorithms that use R-trees in the original space, it reduces the one-pass buffer size by up to 15.7 times and the number of disk accesses by up to $65.3\%$.

A Study on Expressive Characteristics of the Corner in Space (공간에 있어 모서리의 조형적 표현특성에 관한 연구)

  • 김성일;김주연
    • Korean Institute of Interior Design Journal
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    • v.13 no.2
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    • pp.72-79
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    • 2004
  • First of all corner is an essential element to consist the space, but there is not much solid study and basic concept on the corner. The most important reason is the lack of the concept on the corner. The definition of corner by itself carries the term of space. Accordingly arguing the corner in space is to characterize the space. The corner is an important element to build up the space. The purpose of this study is to give a definition on the comer in space and suggest the way of practical use. The corner in space began to transform after Cubism. Therefore this study is bounded after Cubism era. The focus of study on plastical expression properties is on the view point by each era and constitutional point of view. In conclusion, the concept of corner has been switched from the concept of structure to concept of decoration. Also, study found that the concept of corner has the ideology, medium, and characteristics of boundary.

Grasp Stability Analysis in Dual-Space and Optimal Grasp Planning for Two-Fingered Robots in 2-D (듀얼 공간을 이용한 이차원 두 손가락 로봇의 파지 안정성 분석 및 최적 파지 계획)

  • Kook, Myung-Ho;Jang, Myeong-Eon;Lee, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1102-1110
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    • 2006
  • This paper addresses the problem of computing grasp stability of the object for two-fingered robots in two dimensions. The concepts of force-closure and dual space are introduced and discussed in novel point of view, and we transform friction cones in a robot work space to line segments in a dual space. We newly define a grasp stability index by calculating intersection condition between line segments in dual space. Moreover, we propose a method to find the optimal grasp points of the given object by comparing the defined grasp stability index. Its validity and effectiveness are investigated and verified by simulations for quadrangle object and elliptic objects.

A Study on the Iconological Approach of the Korean Traditional Space Design - Focusing on Regional Prototype and Creative Fantasy - (한국 전통공간디자인의 도상해석학적 접근에 관한 연구 - 지역적 원형과 창조적 환상의 개념을 중심으로 -)

  • Park, Kyung-Ae
    • Korean Institute of Interior Design Journal
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    • v.17 no.6
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    • pp.120-127
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    • 2008
  • Korean space design image is a kind of writing as well as one of the sign that dissembles itself as a direct transcript of what it represents. Moreover it is pictorial representation and notions such as mental and perceptual imaginary. Significance of Iconology lies in how we transform image and the imagination that produces it into power of trust and respect. From this point of view, the process of this study is illustrated as follows: At first, this study search out concept of archetype, collective unconsciousness and collective representation that found principles on basic theory for interpretation of korean space icon. Secondly, it mentions theoretical background of iconological contents and structure. And it clarifies Iconology as a method that is applicable logic for Korean space design. Finally, as an analysis of korean space design, this study analyse in three steps that are pre-iconological description, iconological analysis, iconological interpretation each in terms of modernization at regional korean space design. In the step of the pre-iconological description, it describe visual representative style based on era and place. In the step of the iconological analysis, the typical structure is classified in status, vernacular, ethnic, traditional. In the step of the iconological interpretation, connotation is categorized into allegory, multivalence, potential. Through this process, this study suggest that iconology is an appropriate analysis system of Korean space design images that represent symbols combined with our collective emotion.

Feature point extraction using scale-space filtering and Tracking algorithm based on comparing texturedness similarity (스케일-스페이스 필터링을 통한 특징점 추출 및 질감도 비교를 적용한 추적 알고리즘)

  • Park, Yong-Hee;Kwon, Oh-Seok
    • Journal of Internet Computing and Services
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    • v.6 no.5
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    • pp.85-95
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    • 2005
  • This study proposes a method of feature point extraction using scale-space filtering and a feature point tracking algorithm based on a texturedness similarity comparison, With well-defined operators one can select a scale parameter for feature point extraction; this affects the selection and localization of the feature points and also the performance of the tracking algorithm. This study suggests a feature extraction method using scale-space filtering, With a change in the camera's point of view or movement of an object in sequential images, the window of a feature point will have an affine transform. Traditionally, it is difficult to measure the similarity between correspondence points, and tracking errors often occur. This study also suggests a tracking algorithm that expands Shi-Tomasi-Kanade's tracking algorithm with texturedness similarity.

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Modern Control of Space and the British Empire's Management of Irish Territory (공간의 근대적 규율과 영국 제국의 아일랜드 영토 경영)

  • Lee, Sungbum
    • Journal of English Language & Literature
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    • v.57 no.4
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    • pp.553-580
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    • 2011
  • This article addresses how the British Empire administered the discipline of space in nineteenth century Ireland. Space control is a part of modern disciplinary practices. I approach this issue in light of the two modern mapping of space: the geometric mapping of space and the Romantic mapping of space. The former, as seen in map-making, is characterized by imposing a standardized, stratified grid on space by eliminating local characteristics of nature. On the other hand, the latter, as shown in picturesque landscaping, aims to balance a close-up observation of nature and a far-sighted view of it, with the result of creating an ironic tension of local diversity and perspectival totality. These modern disciplinary projects of space repeat themselves in the British management of the colonized Irish territory. As the British conquer other lands, they put to good use both geometric and Romantic disciplinary methods of space. Supervising the Ordnance Survey of Ireland from 1824 to 1846, Thomas Frederick Colby, British Director of Ordnance Survey, made a mathematically strict and scientific mapping of Ireland as a scale of six inches to one mile. Parallelled to this geometric colonization of space, the Romantic colonization of space is efficiently used for the Empire's management of Ireland as well. British tourists and pro-unionist Anglo-Irish landed gentries transform it into the nature of picturesque beauty; Ireland's wild boglands turn aesthetically into desolate but beautiful scenery. Picturesque landscape in England is reborn as an aesthetics of desolation in Ireland.

Performance Evaluation of the Generalized Hough Transform (일반화된 허프변환의 성능평가)

  • Chang, Ji-Young
    • Journal of Convergence for Information Technology
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    • v.7 no.6
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    • pp.143-151
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    • 2017
  • The generalized Hough transform(GHough) can be used effectively for detecting and extracting an arbitrary-shaped 2-D model in an input image. However, the main drawbacks of the GHough are both heavy computation and an excessive storage requirement. Thus, most of the researches so far have focused on reducing both the time and space requirement of the GHough. But it is still not clear how well their improved algorithms will perform under various noise in an input image. Thus, this paper proposes a new framework that can measure the performance of the GHough quantitatively. For this purpose, we view the GHough as a detector in signal detection theory and the ROC curve will be used to specify the performance of the GHough. Finally, we show that we can evaluate the GHough under various noise conditions in an input image.

Development of Localization using Artificial and Natural Landmark for Indoor Mobile Robots (실내 이동 로봇을 위한 자연 표식과 인공 표식을 혼합한 위치 추정 기법 개발)

  • Ahn, Joonwoo;Shin, Seho;Park, Jaeheung
    • The Journal of Korea Robotics Society
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    • v.11 no.4
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    • pp.205-216
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    • 2016
  • The localization of the robot is one of the most important factors of navigating mobile robots. The use of featured information of landmarks is one approach to estimate the location of the robot. This approach can be classified into two categories: the natural-landmark-based and artificial-landmark-based approach. Natural landmarks are suitable for any environment, but they may not be sufficient for localization in the less featured or dynamic environment. On the other hand, artificial landmarks may generate shaded areas due to space constraints. In order to improve these disadvantages, this paper presents a novel development of the localization system by using artificial and natural-landmarks-based approach on a topological map. The proposed localization system can recognize far or near landmarks without any distortion by using landmark tracking system based on top-view image transform. The camera is rotated by distance of landmark. The experiment shows a result of performing position recognition without shading section by applying the proposed system with a small number of artificial landmarks in the mobile robot.

3D Face Alignment and Normalization Based on Feature Detection Using Active Shape Models : Quantitative Analysis on Aligning Process (ASMs을 이용한 특징점 추출에 기반한 3D 얼굴데이터의 정렬 및 정규화 : 정렬 과정에 대한 정량적 분석)

  • Shin, Dong-Won;Park, Sang-Jun;Ko, Jae-Pil
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.6
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    • pp.403-411
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    • 2008
  • The alignment of facial images is crucial for 2D face recognition. This is the same to facial meshes for 3D face recognition. Most of the 3D face recognition methods refer to 3D alignment but do not describe their approaches in details. In this paper, we focus on describing an automatic 3D alignment in viewpoint of quantitative analysis. This paper presents a framework of 3D face alignment and normalization based on feature points obtained by Active Shape Models (ASMs). The positions of eyes and mouth can give possibility of aligning the 3D face exactly in three-dimension space. The rotational transform on each axis is defined with respect to the reference position. In aligning process, the rotational transform converts an input 3D faces with large pose variations to the reference frontal view. The part of face is flopped from the aligned face using the sphere region centered at the nose tip of 3D face. The cropped face is shifted and brought into the frame with specified size for normalizing. Subsequently, the interpolation is carried to the face for sampling at equal interval and filling holes. The color interpolation is also carried at the same interval. The outputs are normalized 2D and 3D face which can be used for face recognition. Finally, we carry two sets of experiments to measure aligning errors and evaluate the performance of suggested process.