• Title/Summary/Keyword: feature generation

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The Generation of 3D Geospatial Data using Digital Photogrammetry System (수치사진측량시스템을 이용한 3차원 공간데이터 구축)

  • Noh, Myoung-Jong;Cho, Woo-Sug
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.11a
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    • pp.29-34
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    • 2005
  • Aerial photogrammetry, which is one of the most frequent used technology in mapping and surveying, has been appreciated for its work flow and accuracy to generate 2D and 3D geospatial data. In aerial photograrnrnetry, more than two photographs are taken over the same target area in different position with overlap. Using these photographs and minimum number of ground control points, 3D stereo model is so formed that the ground surface in reality is reconstructed through analogue/analytical plotter or digital photogrammetry system. In case of digital photogrammetry system, 3D geospatial data could be automatically extracted in partial. Recently, in the advent of aerial digital camera such as ADS40 and DMC, digital photogrammetry system will be in the frist place for generating 3D geospatial data. In this paper, we experimentally generated 3D geospatial data using digital photograrnrnetry system in the aspect of work flow.

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Generation of 3-Dimensional Landscape Map from Aerial Photos (항공사진을 이용한 3차원 경관도 제작)

  • Yeu, Bock-Mo;Jeong, Soo;Kim, Won-Dae
    • Journal of Korean Society for Geospatial Information Science
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    • v.3 no.1 s.5
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    • pp.105-113
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    • 1995
  • Three-dimensional landscape map is very useful in terrain analysis as it looks like real shape of terrain. When three-dimensional landscape map is needed, landscape photos achieved at a position of high elevation or by airplane are generally used. But, this approach can not fully satisfy the user's need to get pictures from various view points. In addition, because photos have some geometric displacement caused by the principle of central projection of camera, it is hard to get accurate locations from the photo. This paper aims to get three-dimensional landscape map similar to real terrain feature from vertical stereo aerial photos by digital photogrammetric techniques. This approach can provide a very useful data for three-dimensional terrain analysis as a function of Geo-Spatial Information System.

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Correlation of Jacques Lacan's Mirror Stage and the process of Remediation on Image Media (쟈크 라캉의 거울단계와 영상미디어의 매개과정과의 연관성)

  • Ahn, Sang-Hyuk
    • Archives of design research
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    • v.18 no.4 s.62
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    • pp.147-154
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    • 2005
  • In this paper, I am going to analyze a correlation of Jacques Lacan's Mirror Stage and the process of remediation on image media. It is because the remediation process of various digital media is letting people pass through one time of mirror stage again. Remediation for the Internet of traditional media, conflict with the virtual world and real world, identification that a virtual image changes a practical image is for it to be caused a remediation process by mutual link of various image media. The Narcissism which occurs in the relation a self with a idealized self searches a new own expression and forms a skillful mania culture. Reflexivity of active mania culture same as a Jacques Lacan's Mirror Stage is to be the possibility becoming the feature of media culture of today. However, if digital media culture generation spends extremely wasting time from the image media, these image media generations cannot grow into new future-type man. According to this, it is necessory to have a study on Visual Literacy that it is related to a Jacques Lacan's Mirror Stage.

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On Motion Planning for Human-Following of Mobile Robot in a Predictable Intelligent Space

  • Jin, Tae-Seok;Hashimoto, Hideki
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.1
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    • pp.101-110
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    • 2004
  • The robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, humans and robots need to be in close proximity to each other as much as possible. Moreover, it is necessary for their interactions to occur naturally. It is desirable for a robot to carry out human following, as one of the human-affinitive movements. The human-following robot requires several techniques: the recognition of the moving objects, the feature extraction and visual tracking, and the trajectory generation for following a human stably. In this research, a predictable intelligent space is used in order to achieve these goals. An intelligent space is a 3-D environment in which many sensors and intelligent devices are distributed. Mobile robots exist in this space as physical agents providing humans with services. A mobile robot is controlled to follow a walking human using distributed intelligent sensors as stably and precisely as possible. The moving objects is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Uncertainties in the position estimation caused by the point-object assumption are compensated using the Kalman filter. To generate the shortest time trajectory to follow the walking human, the linear and angular velocities are estimated and utilized. The computer simulation and experimental results of estimating and following of the walking human with the mobile robot are presented.

The Increase in Regression Rate due to Helical Grain in Solid Fuel of Hybrid Rocket (나선형 홈에 의한 하이브리드 로켓 고체연료의 연소율 증가 특성)

  • Hwang, Yeong-Chun;Lee, Chang-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.12
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    • pp.59-66
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    • 2006
  • To understand the role of helical geometry on the regression rate enhancement, two competing underlying mechanisms such as turbulence enhancement and swirling motion production were studied by numerical calculations. Experimental results showed that the enhancement of heat transfer rate has the very close relation to the increase in regression rate even though the percentage of increase in heat transfer rate is different from that in regression rate. This discrepancy is presumably due to the change of turbulent flow feature caused by so-called "blowing mass flux" from the fuel surface. In this regard, the results of RANS calculation show that the blowing velocity is responsible for the reduction of the swirl generation and the increase in the turbulent kinetic energy. And the dominancy of one of the mechanisms causes the increase in the regression rate. Meanwhile, the increase in turbulent kinetic energy due to the mixing of blowing flow and free stream flow does not contribute for the enhancement of the heat transfer rate to the surface because the blowing flow pushes boundary layer away from the solid surface.

LES for Turbulent Channel Flow with Blowing Velocity (분류유동이 있는 채널 난류유동의 LES 해석)

  • Na, Yang;Lee, Chang-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.8
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    • pp.699-705
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    • 2007
  • Recent experimental data shows that the noticeable feature of irregular roughened spots on the fuel surface occurs during the combustion test with PMMA/GOX in the hybrid rocket motor. The generation of these unexpected patterns is likely to be resulted from the disturbed boundary layer due caused by wall blowing which is intented to simulate the process of fuel vaporization. LES technique was implemented to investigate both the flow characteristics near fuel surface and the subsequent evolution of turbulence modified by the wall blowing. Simple channel geometry instead of circular grain configuration was used for the investigation without chemical reactions in order to allow for a focused examination on the near-wall behavior at the Reynolds number of 22,500. It was shown that the wall blowing pushed turbulent structures upwards making them tilted and this skewed displacement, in effect, left the foot prints of the structures on the surface. This change of kinematics may explain the formation of irregular isolated spots on the fuel surface observed in the experiment.

Digital Surface Model Generation using Aerial Lidar Data and Ground Control Point Acquisition (항공 라이다 데이터를 이용한 공간해상도별 수치표면모형 제작 및 지상기준점 획득 가능성 분석)

  • Kim Kam-Rae;Hwang Won-Soon;Lee Ho-Nam
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.485-490
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    • 2006
  • In this study, the Digital Surface Models of various spatial resolutions were constructed using LIDAR point data on Digital Photogrammetric System. Then, the accuracies of each DSM's were evaluated using GPS surveying data. And also, observable features were classified and their accuracies were evaluated to verify the availability for Ground Control Point. On Socet Set, Digial Photogrametric System 5 DSM's of which spatial resolutions were 0.15m, 0.5m, 1.0m, 2.5m and 5.0m were constructed and the accuracies of eahc DSM's evaluated in RMSE. The RMSE's of each DSM's were 0.03m, 0.05m, 0.08m, 0.12m and 0,19m. The building feature was observable in DSM's of which spatial resolutions were 0.15m, 0.30m and 0.50m. On the contrary, it could hardly be observed in those of other spatial resolutions. In comparison with the digital map at the scale of 1:1,000, the DSM at the spatial resolution of 0.lim was shifted horizaltally by 0.6m-0.7m of RMSE in each X, Y direction. Therefore, GCP of which horizontal RMSE is better than 1m can be obtained from the DSM at the spatial resolution of 0.15m, of which vertical RMSE is 0.03m-0.19m as the RMSE of DSM. This point cannot be used in aerial triangulation of cartography but can be used for GCP in modeling of satellite image at the moderate resolution.

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The Development and Application of the Quasi-dynamic Wetness Index and the Dynamic Wetness Index (유사 동력학적 습윤지수와 동력학적 습윤지수의 개발과 적용)

  • Han, Ji-Young;Kim, Sang-Hyun;Kim, Nam-Won;Kim, Hyun-Jun
    • Journal of Korea Water Resources Association
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    • v.36 no.6
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    • pp.961-969
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    • 2003
  • Formulation of quasi-dynamic wetness index was derived to predict the spatial and temporal distribution of the soil moisture. The algorithm of dynamic wetness index was developed through introducing the convolution integral with the rainfall input. The spatial and temporal behaviors of the wetness index of the Sulmachun Watershed was calculated using the digital elevation model(DEM) and the rainfall data for two years. The spatial distribution of the dynamic wetness index shows most dispersive feature of flow generation among the three assumptions of steady, quasi-dynamic and dynamic. The statistical distribution of the quasi-dynamic wetness index and the dynamic wetness index approximate to the steady state wetness index as the time step is increased. The dynamic wetness index shows mixed distribution of the normalized probability density function.

An Emergency Alert Message Broadcasting System using Null-Packet on Digital TV Broadcasting

  • Kim, Yoo-Won;Park, Seung-Bo;Hong, Myung-Duk;Jo, Geun-Sik
    • Journal of Korea Multimedia Society
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    • v.13 no.12
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    • pp.1767-1777
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    • 2010
  • In digital TV broadcasting, such as terrestrial, cable, satellite, and IPTV, the head-end of digital TV broadcasting has a more complicated transmission structure than that of analog TV broadcasting. Furthermore, digital TV broadcasting has a feature that supports multiplex models, such as Multiple Program Transport Stream (MPTS). Therefore, the purpose of our work was to design and examine a more efficient new system of emergency alert message transmission to support the digital TV broadcasting environments. Digital TV broadcasting is the IP generation or RF transmission of 8-VSB, QAM, and QPSK modulated through a multiplexer or re-multiplexer multiplexed stream as a MPEG-2 Transport Stream after content encoding. The new system proposed in this paper transmits an emergency alert message without scrambling after replacing the PID and payload of the -packet with the message prototype in the TS stream from the multiplexer. If we need to transmit an emergency alert message under digital TV broadcasting services, then the receiver first checks the PID of each packet in the TS stream for the emergency alert message. Next, if a packet is determined to be an emergency alert message, then the set-top box displays the message on the TV screen using its function of On Screen Display, or the PC based software displays the message on the monitor screen using its function of overlay with user interface if the packet is found to be an emergency alert message. We have designed an emergency alert message protocol and a system model. By experiments and analysis of the system, we concluded that the system achieved efficiency and the ability to send and receive emergency alert messages using the system under different digital TV broadcasting service environments.

Feature-Based Light and Shadow Estimation for Video Compositing and Editing (동영상 합성 및 편집을 위한 특징점 기반 조명 및 그림자 추정)

  • Hwang, Gyu-Hyun;Park, Sang-Hun
    • Journal of the Korea Computer Graphics Society
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    • v.18 no.1
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    • pp.1-9
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    • 2012
  • Video-based modeling / rendering developed to produce photo-realistic video contents have been one of the important research topics in computer graphics and computer visions. To smoothly combine original input video clips and 3D graphic models, geometrical information of light sources and cameras used to capture a scene in the real world is essentially required. In this paper, we present a simple technique to estimate the position and orientation of an optimal light source from the topology of objects and the silhouettes of shadows appeared in the original video clips. The technique supports functions to generate well matched shadows as well as to render the inserted models by applying the estimated light sources. Shadows are known as an important visual cue that empirically indicates the relative location of objects in the 3D space. Thus our method can enhance realism in the final composed videos through the proposed shadow generation and rendering algorithms in real-time.