• 제목/요약/키워드: Spatial Transformation

검색결과 489건 처리시간 0.028초

음장의 공간적 변환기법을 이용한 타이어 구조 진동 소음 측정 (Measurement of Tire Structural Vibration Noise Using Spatial Transformation of Sound Field Technique)

  • 김병삼
    • 한국음향학회지
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    • 제14권5호
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    • pp.11-19
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    • 1995
  • 본 논문에서는 불규칙한 노면이 설치된 섀시 동력계(chassis dynamometer)로 부터 가진된 타이어의 구조 진동 소음을 음장의 공간적 변환기법을 이용하여 측정하였다. 음장의 공간적 변환기법은 소음원으로 부터 원거리까지의 전파를 계산하는 기법이다. 즉, 한평면의 음향 측정으로 부터 측정 평면에서 멀리 떨어지거나 더 가까운 평면에서의 음장을 표현하는 변수들인 음압, 음향 인텐시티, 입자속도 등을 계산한다. 측정 평면에서 음원쪽으로 가까운 평면의 계산은 관접음장 홀로그래피를 적용하여 계산하고 먼 쪽은 헬름흘쓰 적분식을 적용한다 측정결과로 부터 타이어 구조 진동 소음의 방사형태와 소음원의 위치를 예측하였다.

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Temporal and Spatial Expression of Homeotic Genes Is Important for Segment-specific Neuroblast 6-4 Lineage Formation in Drosophila

  • Kang, Sun-Young;Kim, Su-Na;Kim, Sang Hee;Jeon, Sang-Hak
    • Molecules and Cells
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    • 제21권3호
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    • pp.436-442
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    • 2006
  • Different proliferation of neuroblast 6-4 (NB6-4) in the thorax and abdomen produces segmental specific expression pattern of several neuroblast marker genes. NB6-4 is divided to form four medialmost cell body glia (MM-CBG) per segment in thorax and two MM-CBG per segment in abdomen. As homeotic genes determine the identities of embryonic segments along the A/P axis, we investigated if temporal and specific expression of homeotic genes affects MM-CBG patterns in thorax and abdomen. A Ubx loss-of-function mutation was found to hardly affect MM-CBG formation, whereas abd-A and Abd-B caused the transformation of abdominal MM-CBG to their thoracic counterparts. On the other hand, gain-of-function mutants of Ubx, abd-A and Abd-B genes reduced the number of thoracic MM-CBG, indicating that thoracic MM-CBG resembled abdominal MM-CBG. However, mutations in Polycomb group (PcG) genes, which are negative transregulators of homeotic genes, did not cause the thoracic to abdominal MM-CBG pattern transformation although the number of MM-CBG in a few percent of embryos were partially reduced or abnormally patterned. Our results indicate that temporal and spatial expression of the homeotic genes is important to determine segmental-specificity of NB6-4 daughter cells along the anterior-posterior (A/P) axis.

Line Based Transformation Model (LBTM) for high-resolution satellite imagery rectification

  • Shaker, Ahmed;Shi, Wenzhong
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.225-227
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    • 2003
  • Traditional photogrammetry and satellite image rectification technique have been developed based on control-points for many decades. These techniques are driven from linked points in image space and the corresponding points in the object space in rigorous colinearity or coplanarity conditions. Recently, digital imagery facilitates the opportunity to use features as well as points for images rectification. These implementations were mainly based on rigorous models that incorporated geometric constraints into the bundle adjustment and could not be applied to the new high-resolution satellite imagery (HRSI) due to the absence of sensor calibration and satellite orbit information. This research is an attempt to establish a new Line Based Transformation Model (LBTM), which is based on linear features only or linear features with a number of ground control points instead of the traditional models that only use Ground Control Points (GCPs) for satellite imagery rectification. The new model does not require any further information about the sensor model or satellite ephemeris data. Synthetic as well as real data have been demonestrated to check the validity and fidelity of the new approach and the results showed that the LBTM can be used efficiently for rectifying HRSI.

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A Spatial Band Wavelet Video Coding

  • Kim, Eung-Tae;Park, Sang-Ju
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.603-606
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    • 2002
  • EZW, a wavelet transformation based compression algorithm, utilizes the correlations of the wavelet coefficients between subbands. Due to the reason that, it is based on Zero Tree's parent-descendant dependency of the subbands, subband coding is possible, but it is not efficient for applications, which require multi-resolution restorations. In this paper we compare and analyze the performance between spatial band coding, which apply the correlation between adjusting pixels, and EZW So as to prove that spatial band coding is superior to EZW in the sense that it exhibit higher PSNR values and that it is apt to molti-resolution restoration.

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자율 이동로봇의 경로추정을 위한 적응적 공간좌표 검출 기법 (Adaptive Spatial Coordinates Detection Scheme for Path-Planning of Autonomous Mobile Robot)

  • 이정석;고정환
    • 전기학회논문지P
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    • 제55권2호
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    • pp.103-109
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    • 2006
  • In this paper, the detection scheme of the spatial coordinates based on stereo camera for a intelligent path planning of an automatic mobile robot is proposed. In the proposed system, face area of a moving person is detected from a left image among the stereo image pairs by using the YCbCr color model and its center coordinates are computed by using the centroid method and then using these data, the stereo camera embedded on the mobile robot can be controlled for tracking the moving target in real-time. Moreover, using the disparity mad obtained from the left and right images captured by the tracking-controlled stereo camera system and the perspective transformation between a 3-D scene. and an image plane, depth information can be detected. Finally, based-on the analysis of these calculated coordinates, a mobile robot system is derived as a intelligent path planning and a estimation.

구아리노 구아리니 건축에 나타난 기하학적 표현에 관한 연구 - 그의 산 로렌쪼 성당의 공간형태 분석을 중심으로 - (A Study on the Geometrical Expression Shown in the Architecture of Guarino Guarini - Focusing on the Analysis of Spatial Form in Guarino Guarini's Church of San Lorenzo-)

  • 한명식
    • 한국실내디자인학회논문집
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    • 제14권3호
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    • pp.95-102
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    • 2005
  • Guarini's architectural contribution has simply focused on the dome structure that has been known to us; however, his geometric and spatial construction has been overlooked so far Through this study, it has been demonstrated that the dome structure was simply part of geometrical forms that Guarini wanted to express ultimately and it functioned as a geometrical element such as the network combined with the entire spatial structure. The purpose of this study is to reevaluate Guarini's architectural thought by means of investigating the ultimate principles of spatial composition appeared in the late Baroque architecture through the analysis of the principles of spatial composition and organized formal Idioms by Guarini's geometrical concepts. Besides, it has been assumed that such geometrical concepts by Guarini's mathematical proportion and his reiteration and change of diagrams could be clearly distinguished from the Classical geometry in the Renaissance and Guarini. suggested a way to create a new space through more active and amusing application and transformation. In this aspect, Guarini's principles of geometric composition will be one of the role models that need to be seriously reconsidered in chaotic reality of modern architecture.

공간적 파라텍스트로서의 모바일 혼합현실 스토리텔링 (Mobile Mixed Reality Storytelling as Spatial Paratexts)

  • 김여진;이윤재;남양희
    • 한국HCI학회논문지
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    • 제10권2호
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    • pp.57-64
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    • 2015
  • 본 논문은 문학비평에서 사용되는 파라텍스트라는 개념을 통해 모바일 혼합현실 기술의 가치와 의미, 속성을 새롭게 조명한다. 물리적 장소가 메인텍스트이자 고정된 체계인 '랑그(langue)'라면 일반 사용자들이 현장에 남기는 참여적 저작과 시공간적 흔적과 발화는 '빠롤(parole)'에 해당하며, 이들이 혼합된 모바일 혼합현실 스토리텔링을 파라텍스트로 보았다. 이에 대한 구현 가능한 방법과 미적 변용의 실험 및 응용들을 제시함으로써 모바일 혼합현실 공간의 파라텍스트 개념을 구체화했다.

디지털 트윈 구현을 위한 3차원 객체(건물) 갱신 및 구축 방안 연구 (Study on 3D Object (Building) Update and Construction Method for Digital Twin Implementation)

  • 곽병용;강병주
    • 산업경영시스템학회지
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    • 제44권4호
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    • pp.186-192
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    • 2021
  • Recently, the demand for more precise and demand-oriented customized spatial information is increasing due to the 4th industrial revolution. In particular, the use of 3D spatial information and digital twins which based on spatial information, and research for solving social problems in cities by using such information are continuously conducted. Globally, non-face-to-face services are increasing due to COVID-19, and the national policy direction is also rapidly progressing digital transformation, digitization and virtualization of the Korean version of the New Deal, which means that 3D spatial information has become an important factor to support it. In this study, physical objects for cities defined by world organizations such as ISO, OGC, and ITU were selected and the target of the 3D object model was limited to buildings. Based on CityGML2.0, the data collected using a drone suitable for building a 3D model of a small area is selected to be updated through road name address and building ledger, which are administrative information related to this, and LoD2.5 data is constructed and urban space. It was intended to suggest an object update method for a 3D building among data.

Conflicts and Resolutions due to the Expansion of Urban Heritage - Focusing on Historic Sites and Hanok Areas in Seoul -

  • Hyun Chul Youn;Seong Lyong Ryoo
    • Architectural research
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    • 제25권2호
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    • pp.29-40
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    • 2023
  • The purpose of this study is to analyze the conflicts caused by the spatial expansion in two types of urban heritage in Seoul. To explain the national and professional orientation found in each spatial transformation, the study brought the concept of 'historic state' and 'epitome,' thereby examining the operating system of the conflicts. Field observations and stakeholder interviews were performed based on literature and historical research. The study results are as follows. ①In the case of Gwanghwamun and Donuimun, the spatial expansion is to find the historic state of the sites. Gwanghwamun with high national status and substance, conflicts show a pattern that spreads to memory conflicts. Donuimun is relatively unknown and has no substance so that a flexible method of digital restoration was applied. ② In the case of Ikseon-dong and Bukchon hanok, they show heterogeneous spatial expansion. The conflicts in relation to this is caused by the epitome of hanok. In Ikseon-dong, illegal installation of structures(non-epitome) is prevalent, while in Bukchon, there was a process of transferring the new basement(non-epitome) as part of the hanok. ③Conflicts in Gwanghwamun can be coordinated by referring to the digital restoration of Donuimun, and conflicts in Ikseon-dong can be resolved by taking Bukchon as a precedent.

SMAT 알고리즘을 이용한 위상학적 모델 추출 방법 (The Research on Extraction of Topology Model Using Straight Medial Axis Transformation Algorithm)

  • 박소영;이지영
    • Spatial Information Research
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    • 제20권2호
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    • pp.117-127
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    • 2012
  • 본 연구는 실내 GIS 모델을 구축하기 위한 위상학적 모델이 객체의 기하학적 특징을 반영할 필요성에 의해, 기하적 정보를 갖는 위상학적 모델인 기하 네트워크 모델을 자동 구축하는 알고리즘을 개발하는 것을 목적으로 한다. GNM의 요소 중 기하 정보를 갖는 요소를 자동 추출하기 위한 중심 알고리즘으로서 직선 중심축 추출 알고리즘을 개발하였다. 개발된 SMAT 알고리즘은 기존의 S-MAT 알고리즘을 활용하여 일반화되었고, 해당되는 객체의 범위를 단순 폴리곤에서 내부 폐색 구역을 갖는 폴리곤으로 확장하였다. 자동 구축된 GNM은 타 시스템에서의 활용 및 용이한 접근을 위해 최종적으로 .csv 파일로 출력된다. GNM 자동 추출 알고리즘은 최단 경로 탐색, 위급 상황 발생 시 대피로 안내, 상황에 따른 차별적 분석 등 다양한 경우에 효율적으로 활용될 수 있다.