• Title/Summary/Keyword: memory reconstruction

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Experimental characterization of a smart material via DIC

  • Casciati, Sara;Bortoluzzi, Daniele;Faravelli, Lucia;Rosadini, Luca
    • Smart Structures and Systems
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    • v.30 no.3
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    • pp.255-261
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    • 2022
  • When no extensometer is available in a generic tensile-compression test carried out by a universal testing machine (for instance the model BIONIX from Material Testing Systems (MTS)), the test results only provide the relative displacement between the machine grips. The test does not provide any information on the local behaviour of the material. This contribution presents the potential of an application of Digital Image Correlation (DIC) toward the reconstruction of the behaviour along the specimen. In particular, the authors test a Ni-Ti shape memory alloys (SMA) specimen with emphasis on the coupling of the two measurement techniques.

An Efficient Polygonal Surface Reconstruction (효율적인 폴리곤 곡면 재건 알고리즘)

  • Park, Sangkun
    • Journal of Institute of Convergence Technology
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    • v.10 no.1
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    • pp.7-12
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    • 2020
  • We describe a efficient surface reconstruction method that reconstructs a 3D manifold polygonal mesh approximately passing through a set of 3D oriented points. Our algorithm includes 3D convex hull, octree data structure, signed distance function (SDF), and marching cubes. The 3D convex hull provides us with a fast computation of SDF, octree structure allows us to compute a minimal distance for SDF, and marching cubes lead to iso-surface generation with SDF. Our approach gives us flexibility in the choice of the resolution of the reconstructed surface, and it also enables to use on low-level PCs with minimal peak memory usage. Experimenting with publicly available scan data shows that we can reconstruct a polygonal mesh from point cloud of sizes varying from 10,000 ~ 1,000,000 in about 1~60 seconds.

Measurement of 3D Flow inside Micro-tube Using Digital Holographic PTV Technique (디지털 Holographic PTV기법을 이용한 미세튜브 내부 3차원 유동장 측정)

  • Kim, Seok;Kim, Ju-Hee;Lee, Sang-Joon
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.177-178
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    • 2006
  • Digital holographic particle tracking velocimetry (HPTV) is developed by single high-speed camera and single continuous laser with long coherent length. This system can directly capture 4000 hologram fringe images for 1 second through a camera computer memory. The 3D particle location is made of the reconstruction by using a computer hologram algorithm. This system can successfully be applied to instantaneous 3D velocity measurement in the water flow inside a micro-tube. The average of 100 instantaneous velocity vectors is obtained by reconstruction and tracking with the time of evolution of recorded fringes images. In the near future, we will apply this technique to measure 3D flow information inside various micro structures.

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Image-based Surfel Reconstruction by LDI Plane Sweeping (LDI 평면 이동에 의한 이미지 기반 Surfel 복원)

  • Lee, Jung;Kim, Chang-Hun
    • Journal of KIISE:Software and Applications
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    • v.36 no.11
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    • pp.947-954
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    • 2009
  • This paper proposes a novel method that reconstructs a surfel-based object by using visual hull from multiple images. The surfel is a point primitive that effectively approximates point-set surface. We create the surfel representation of an object from images by combining the LDC(Layered Depth Cube) surfel sampling with the concept of visual hull that represents the approximated shape from input images. Because the surfel representation requires relatively smaller memory resources than the polygonal one and its LDC resolution is freely changed, we can control the reconstruction quality of the target object and acquire the maximal quality on the given memory resource.

The General Plan of Reconstruction of Pyongyang and the Role of Kim Jung-hee: Myths and History (건축가 김정희와 평양시 복구 총 계획도: 신화와 역사)

  • Park, Dongmin
    • Journal of architectural history
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    • v.27 no.2
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    • pp.125-138
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    • 2018
  • During the 1950s, the North Koreans rebuilt their capital-Pyongyang-as a modern city under the principle of Soviet urban design. One North Korean architect, Kim Jung-hee, has been widely credited since the late 1980s as the master architect of the General Plan of the city's reconstruction. While Kim Jung-hee played a crucial role in its reconstruction, his heroic image as the founding architect of Pyongyang is considerably attributed to North Korea's mythical narratives rather than his historical activities. This paper argues that Pyongyang's postwar urban design was not a work made by a single actor, Kim Jung-hee; rather, it was a long-term collaborative project in which a team of North Korean architects and Soviet technical advisors took their respective roles. Beginning in the late 1980s, North Korea, which had been struggling with economic decline and an increasing sense of lagging behind in its rivalry with its Southern counterpart, used heroic narratives during the 1950s' postwar reconstruction period as an important propaganda tool for their regime. In this mythical narrative of Pyongyang's reconstruction, massive economic and technical aid from other communist countries has often disappeared, and the memory of the architects who contributed greatly to the reconstruction but later purged in North Korea have also completely vanished. Kim Jung-hee, meanwhile, remained in this epic as the founding architect who rebuilt the city in faithful accordance with the leadership of Kim Il Sung.

3D Point Cloud Reconstruction Technique from 2D Image Using Efficient Feature Map Extraction Network (효율적인 feature map 추출 네트워크를 이용한 2D 이미지에서의 3D 포인트 클라우드 재구축 기법)

  • Kim, Jeong-Yoon;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.26 no.3
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    • pp.408-415
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    • 2022
  • In this paper, we propose a 3D point cloud reconstruction technique from 2D images using efficient feature map extraction network. The originality of the method proposed in this paper is as follows. First, we use a new feature map extraction network that is about 27% efficient than existing techniques in terms of memory. The proposed network does not reduce the size to the middle of the deep learning network, so important information required for 3D point cloud reconstruction is not lost. We solved the memory increase problem caused by the non-reduced image size by reducing the number of channels and by efficiently configuring the deep learning network to be shallow. Second, by preserving the high-resolution features of the 2D image, the accuracy can be further improved than that of the conventional technique. The feature map extracted from the non-reduced image contains more detailed information than the existing method, which can further improve the reconstruction accuracy of the 3D point cloud. Third, we use a divergence loss that does not require shooting information. The fact that not only the 2D image but also the shooting angle is required for learning, the dataset must contain detailed information and it is a disadvantage that makes it difficult to construct the dataset. In this paper, the accuracy of the reconstruction of the 3D point cloud can be increased by increasing the diversity of information through randomness without additional shooting information. In order to objectively evaluate the performance of the proposed method, using the ShapeNet dataset and using the same method as in the comparative papers, the CD value of the method proposed in this paper is 5.87, the EMD value is 5.81, and the FLOPs value is 2.9G. It was calculated. On the other hand, the lower the CD and EMD values, the better the accuracy of the reconstructed 3D point cloud approaches the original. In addition, the lower the number of FLOPs, the less memory is required for the deep learning network. Therefore, the CD, EMD, and FLOPs performance evaluation results of the proposed method showed about 27% improvement in memory and 6.3% in terms of accuracy compared to the methods in other papers, demonstrating objective performance.

VLSI Architecture Design of Reconstruction Filter for Morphological Image Segmentation (형태학적 영상 분할을 위한 재구성 필터의 VLSI 구조 설계)

  • Lee, Sang-Yeol;Chung, Eui-Yoon;Lee, Ho-Young;Kim, Hee-Soo;Ha, Yeong-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.12
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    • pp.41-50
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    • 1999
  • In this paper, the new VLSI architecture of a reconstruction filter for morphological image segmentation is proposed. The filter, based on the $h_{max}$ operation, simplifies the interior of each region while preserving the boundary information. The proposed architecture adopts a partitioned memory structure and an efficient image scanning strategy to reduce the operations. The proposed memory partitioning scheme makes it possible that every data required for processing can be read from each memory at a time, resulting in parallel data processing. By the extended connectivity consideration, the operation is much decreased because more simplification is achieved in scanning stage. The selective raster scan strategy endows the satisfactory noise removal capability with negligible hardware complexity increase. The proposed architecture is designed using VHDL, and functional evaluation is performed by the CAD tool, Mentor. The experiment results show that the proposed architecture can simplify image profile with less than 18% operations of the conventional method.

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Is "Southern Literature" Alive?: Machine Dream's Incomplete Memories and Their Materiality (미국'남부문학'은 현존하는가?-『머쉰 드림』에 나타난 미완성의 기억과 기억의 물질성)

  • Yu, Jeboon
    • Journal of English Language & Literature
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    • v.59 no.4
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    • pp.545-567
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    • 2013
  • Keeping in mind the hybridity and plurality of Southern Literature, this paper discusses the traits of Southern literature in Jayne Ann Phillips's first novel, Machine Dream. The novel's frequent use of memory and oral reconstruction of a family history accompanied by the feeling of loss in the process of depicting the South's past typically signifies "The Southern" which reminds us of the works of William Faulkner, Katherine Ann Porter, and Eudora Welty. Nevertheless, Phillips's South is more fragmented and her narrative is more evasive and varied than any of her Southern predecessors. The South of the twentieth century from the period of Depression until 1972 is reconstructed differently depending on memories and desires of the four members of Hampson family in this novel, either as a place of nostalgia or as the place of trauma or as the place to survive only in memory. The oxymoronic title of the novel, "machine dreams" signifies that dream and memory of the South cannot remain independent in its epistemological entity but exist as a mixture of materiality of every day life in the modern South. The hybridity of this dream and of the South is what defines itself as Southern. Yet Phillips retains feeling of loss and lament enough to create a modern Southern novel rooted in Southern Literature. Thus, the title itself works an antinomic signifier of both the presence and absence of the dream of the South and of Southern Literature.

High-resolution 3D Object Reconstruction using Multiple Cameras (다수의 카메라를 활용한 고해상도 3차원 객체 복원 시스템)

  • Hwang, Sung Soo;Yoo, Jisung;Kim, Hee-Dong;Kim, Sujung;Paeng, Kyunghyun;Kim, Seong Dae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.10
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    • pp.150-161
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    • 2013
  • This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

An Efficient MBR Compression Technique for Main Memory Multi-dimensional Indexes (메인 메모리 다차원 인덱스를 위한 효율적인 MBR 압축 기법)

  • Kim, Joung-Joon;Kang, Hong-Koo;Kim, Dong-Oh;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.9 no.2
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    • pp.13-23
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    • 2007
  • Recently there is growing Interest in LBS(Location Based Service) requiring real-time services and the spatial main memory DBMS for efficient Telematics services. In order to optimize existing disk-based multi-dimensional Indexes of the spatial main memory DBMS in the main memory, multi-dimensional index structures have been proposed, which minimize failures in cache access by reducing the entry size. However, because the reduction of entry size requires compression based on the MBR of the parent node or the removal of redundant MBR, the cost of MBR reconstruction increases in index update and the efficiency of search is lowered in index search. Thus, to reduce the cost of MBR reconstruction, this paper proposed the RSMBR(Relative-Sized MBR) compression technique, which applies the base point of compression differently in case of broad distribution and narrow distribution. In case of broad distribution, compression is made based on the left-bottom point of the extended MBR of the parent node, and in case of narrow distribution, the whole MBR is divided into cells of the same size and compression is made based on the left-bottom point of each cell. In addition, MBR was compressed using a relative coordinate and size to reduce the cost of search in index search. Lastly, we evaluated the performance of the proposed RSMBR compression technique using real data, and proved its superiority.

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