• Title/Summary/Keyword: 3-D object modeling

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Design of an Effective Bump Mapping Hardware Architecture Using Angular Operation (각 연산을 이용한 효과적인 범프 매핑 하드웨어 구조 설계)

  • 이승기;박우찬;김상덕;한탁돈
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.11
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    • pp.663-674
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    • 2003
  • Bump mapping is a technique that represents the detailed parts of the object surface, such as a perturberance of the skin of a peanut, using the geometry mapping without complex modeling. However, the hardware implementation for bump mapping is considerable, because a large amount of per pixel computation, including the normal vector shading, is required. In this paper, we propose a new bump mapping algorithm using the polar coordinate system and its hardware architecture. Compared with other existing architectures, our approach performs bump mapping effectively by using a new vector rotation method for transformation into the reference space and minimizing illumination calculation. Consequently, our proposed architecture reduces a large amount of computation and hardware requirements.

Temperature Field and Thermal Stress Simulation of Solid Brake Disc Based on Three-dimensional Model (3차원 브레이크 디스크 모델의 온도 분포와 열응력 시뮬레이션에 관한 연구)

  • Hwang, Pyung;Seo, Hee-Chang;Wu, Xuan
    • Tribology and Lubricants
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    • v.26 no.1
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    • pp.31-36
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    • 2010
  • The brake system is an important part of the automobile safety system. The disc brake system is divided into two parts: a rotating axi-symmetrical disc, and the stationary pads. The frictional heat, which is generated on the interface of the disc and pads, can cause high temperatures during the braking process. The frictional heat source (the pads) is moving on the disc and the location is time-dependent. Our study applies a moving heat source, which is defined by the time and space variable on the frictional surface, in order to simulate the frictional heat behavior accurately during the braking process. The object of the present work is the determination of the temperature distribution and thermal stress in the solid disc by non-axisymmetric 3D modeling for repeated braking.

A Relative Depth Estimation Algorithm Using Focus Measure (초점정보를 이용한 패턴간의 상대적 깊이 추정알고리즘 개발)

  • Jeong, Ji-Seok;Lee, Dae-Jong;Shin, Yong-Nyuo;Chun, Myung-Geun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.6
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    • pp.527-532
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    • 2013
  • Depth estimation is an essential factor for robot vision, 3D scene modeling, and motion control. The depth estimation method is based on focusing values calculated in a series of images by a single camera at different distance between lens and object. In this paper, we proposed a relative depth estimation method using focus measure. The proposed method is implemented by focus value calculated for each image obtained at different lens position and then depth is finally estimated by considering relative distance of two patterns. We performed various experiments on the effective focus measures for depth estimation by using various patterns and their usefulness.

Automatic Building Extraction Using LIDAR and Aerial Image (LIDAR 데이터와 수치항공사진을 이용한 건물 자동추출)

  • Jeong, Jae-Wook;Jang, Hwi-Jeong;Kim, Yu-Seok;Cho, Woo-Sug
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.3 s.33
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    • pp.59-67
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    • 2005
  • Building information is primary source in many applications such as mapping, telecommunication, car navigation and virtual city modeling. While aerial CCD images which are captured by passive sensor(digital camera) provide horizontal positioning in high accuracy, it is far difficult to process them in automatic fashion due to their inherent properties such as perspective projection and occlusion. On the other hand, LIDAR system offers 3D information about each surface rapidly and accurately in the form of irregularly distributed point clouds. Contrary to the optical images, it is much difficult to obtain semantic information such as building boundary and object segmentation. Photogrammetry and LIDAR have their own major advantages and drawbacks for reconstructing earth surfaces. The purpose of this investigation is to automatically obtain spatial information of 3D buildings by fusing LIDAR data with aerial CCD image. The experimental results show that most of the complex buildings are efficiently extracted by the proposed method and signalize that fusing LIDAR data and aerial CCD image improves feasibility of the automatic detection and extraction of buildings in automatic fashion.

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Development of an Open BIM-Based Korean Traditional House Component Library Using an XML Parametric Information Approach

  • Kim, In-Han;Jin, Jin;Seo, Jong-Cheol;Kim, Kwan-Soo
    • Architectural research
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    • v.13 no.3
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    • pp.11-18
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    • 2011
  • With the rapid development of computer technology and ongoing destruction of traditional buildings, more and more attention is paid to digital methods for the design and preservation of traditional buildings. Unlike 2D methods, Building Information Modeling (BIM) provides an object-oriented and parametric digital representation way for traditional building components. However, one of the main limitations currently is that parametric information cannot be exchanged between BIM software packages. Therefore each kind of software must have their own parametric library which causes extensive works. In this research, the authors developed an open BIM-based library using an XML parametric approach to solve the above problems, represented traditional components according to an XML schema, and parametrically implemented these XML files in a browser which can be accessed by users for their easy component edit and selection. And then based on the XML file of one component, implemented an Add-on in ArchiCAD for users to parametrically edit and directly utilize. Thus based on these XML files, a browser for users' view and selection purpose and an add-on for users' application purpose were developed. Future research will focus on implementing these XML files in other BIM tools like Revit and Digital Project. If the whole library was to be completed based on this XML approach, an open BIM-based library would be established that all kinds of BIM software users could apply this parametric library for easy modeling of traditional houses.

Rubus fruticosus leaf extract inhibits vascular dementia-induced memory impairment and neuronal loss by attenuating neuroinflammation

  • Nak Song Sung;Sun Ho Uhm;Hyun Bae Kang;Nam Seob Lee;Young-Gil Jeong;Do Kyung Kim;Nak-Yun Sung;Dong-Sub Kim;Young Choon Yoo;Seung Yun Han
    • Anatomy and Cell Biology
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    • v.56 no.4
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    • pp.494-507
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    • 2023
  • Vascular dementia (VaD) is characterized by progressive memory impairment, which is associated with microglia-mediated neuroinflammation. Polyphenol-rich natural plants, which possess anti-inflammatory activities, have attracted scientific interest worldwide. This study investigated whether Rubus fruticosus leaf extract (RFLE) can attenuate VaD. Sprague-Dawley rats were separated into five groups: SO, sham-operated and treated with vehicle; OP, operated and treated with vehicle; RFLE-L, operated and treated with low dose (30 mg/kg) of RFLE; RFLE-M, operated and treated with medium dose (60 mg/kg) of RFLE; and RFLE-H, operated and treated with high dose (90 mg/kg) of RFLE. Bilateral common carotid artery and hypotension were used as a modeling procedure, and the RFLE were intraorally administered for 5 days (preoperative 2 and postoperative 3 days). The rats then underwent memory tests including the novel object recognition, Y-maze, Barnes maze, and passive avoidance tests, and neuronal viability and neuroinflammation were quantified in their hippocampi. The results showed that the OP group exhibited VaD-associated memory deficits, neuronal death, and microglial activation in hippocampi, while the RFLE-treated groups showed significant attenuation in all above parameters. Next, using BV-2 microglial cells challenged with lipopolysaccharide (LPS), we evaluated the effects of RFLE in dynamics of proinflammatory mediators and the upstream signaling pathway. RFLE pretreatment significantly inhibited the LPS-induced release of nitric oxide, TNF-α, and IL-6 and upregulation of the MAPKs/NF-κB/iNOS pathway. Collectively, we suggest that RFLE can attenuate the histologic alterations and memory deficits accompanied by VaD, and these roles are, partly due to the attenuation of microglial activation.

Orientation Analysis between UAV Video and Photos for 3D Measurement of Bridges (교량의 3차원 측정을 위한 UAV 비디오와 사진의 표정 분석)

  • Han, Dongyeob;Park, Jae Bong;Huh, Jungwon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.6
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    • pp.451-456
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    • 2018
  • UAVs (Unmanned Aerial Vehicles) are widely used for maintenance and monitoring of facilities. It is necessary to acquire a high-resolution image for evaluating the appearance state of the facility in safety inspection. In addition, it is essential to acquire the video data in order to acquire data over a wide area rapidly. In general, since video data does not include position information, it is difficult to analyze the actual size of the inspection object quantitatively. In this study, we evaluated the utilization of 3D point cloud data of bridges using a matching between video frames and reference photos. The drones were used to acquire video and photographs. And exterior orientations of the video frames were generated through feature point matching with reference photos. Experimental results showed that the accuracy of the video frame data is similar to that of the reference photos. Furthermore, the point cloud data generated by using video frames represented the shape and size of bridges with usable accuracy. If the stability of the product is verified through the matching test of various conditions in the future, it is expected that the video-based facility modeling and inspection will be effectively conducted.

Comparison Among Sensor Modeling Methods in High-Resolution Satellite Imagery (고해상도 위성영상의 센서모형과 방법 비교)

  • Kim, Eui Myoung;Lee, Suk Kun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6D
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    • pp.1025-1032
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    • 2006
  • Sensor modeling of high-resolution satellites is a prerequisite procedure for mapping and GIS applications. Sensor models, describing the geometric relationship between scene and object, are divided into two main categories, which are rigorous and approximate sensor models. A rigorous model is based on the actual geometry of the image formation process, involving internal and external characteristics of the implemented sensor. However, approximate models require neither a comprehensive understanding of imaging geometry nor the internal and external characteristics of the imaging sensor, which has gathered a great interest within photogrammetric communities. This paper described a comparison between rigorous and various approximate sensor models that have been used to determine three-dimensional positions, and proposed the appropriate sensor model in terms of the satellite imagery usage. Through the case study of using IKONOS satellite scenes, rigorous and approximate sensor models have been compared and evaluated for the positional accuracy in terms of acquirable number of ground controls. Bias compensated RFM(Rational Function Model) turned out to be the best among compared approximate sensor models, both modified parallel projection and parallel-perspective model were able to be modelled with a small number of controls. Also affine transformation, one of the approximate sensor models, can be used to determine the planimetric position of high-resolution satellites and perform image registration between scenes.

A Framework Integrating Cost and Schedule based on BIM using IFC (IFC활용 BIM기반 공정/원가 통합관리 프레임워크)

  • Lee, Jin-Gang;Lee, Hyun-Soo;Park, Moonseo;Jung, Minhyuk
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.3
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    • pp.53-64
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    • 2013
  • In building construction project, there are numerous information or data parts across many different software applications and professional specialists. BIM (Building Information Modeling), as a medium for managing information generated during construction project, it is intended to enhance the effectiveness of construction management and reap a lot of advantages such as, automatic quantity takeoff, error-free estimation, 4D(3D+Time), 5D(4D+Cost) simulation. Nevertheless, the overall and practical effectiveness of BIM utilization is difficult to justify at this stage. While helpful, there are some limitation when BIM applied to construction management due to the differences of data processing process between BIM and work in the field, limitations of information generated from BIM object and interoperability problem among BIM application. Therefore, this paper propose a framework integrating BIM with cost-schedule information using IFC. And we construct the system prototype based on the framework and performed case study to examine the framework. The proposed framework provides the information basis for BIM based cost-schedule integration. ultimately, the framework increase the utilization of BIM and work efficiency of construction industry by supporting an understanding of information.

Utilizing Airborne LiDAR Data for Building Extraction and Superstructure Analysis for Modeling (항공 LiDAR 데이터를 이용한 건물추출과 상부구조물 특성분석 및 모델링)

  • Jung, Hyung-Sup;Lim, Sae-Bom;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.3
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    • pp.227-239
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    • 2008
  • Processing LiDAR (Light Detection And Ranging) data obtained from ALS (Airborne Laser Scanning) systems mainly involves organization and segmentation of the data for 3D object modeling and mapping purposes. The ALS systems are viable and becoming more mature technology in various applications. ALS technology requires complex integration of optics, opto-mechanics and electronics in the multi-sensor components, Le. data captured from GPS, INS and laser scanner. In this study, digital image processing techniques mainly were implemented to gray level coded image of the LiDAR data for building extraction and superstructures segmentation. One of the advantages to use gray level image is easy to apply various existing digital image processing algorithms. Gridding and quantization of the raw LiDAR data into limited gray level might introduce smoothing effect and loss of the detail information. However, smoothed surface data that are more suitable for surface patch segmentation and modeling could be obtained by the quantization of the height values. The building boundaries were precisely extracted by the robust edge detection operator and regularized with shape constraints. As for segmentation of the roof structures, basically region growing based and gap filling segmentation methods were implemented. The results present that various image processing methods are applicable to extract buildings and to segment surface patches of the superstructures on the roofs. Finally, conceptual methodology for extracting characteristic information to reconstruct roof shapes was proposed. Statistical and geometric properties were utilized to segment and model superstructures. The simulation results show that segmentation of the roof surface patches and modeling were possible with the proposed method.