• Title/Summary/Keyword: space object

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Improvement of Ortho Image Quality by Unmanned Aerial Vehicle (UAV에 의한 정사영상의 품질 개선 방안)

  • Um, Dae-Yong;Park, Joon-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.568-573
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    • 2018
  • UAV(Unmanned Aerial Vehicle) is widely used in space information construction, agriculture, fisheries, weather observation, communication, and entertainment fields because they are cheaper and easier to operate than manned aircraft. In particular, UAV have attracted much attention due to the speed and cost of data acquisition in the field of spatial information construction. However, ortho image images produced using UAVs are distorted in buildings and forests. It is necessary to solve these problems in order to utilize the geospatial information field. In this study, fixed wing, rotary wing, vertical take off and landing type UAV were used to detect distortions of ortho image of UAV under various conditions, and various object areas such as construction site, urban area, and forest area were captured and analysed. Through the research, it was found that the redundancy of the unmanned aerial vehicle image is the biggest factor of the distortion phenomenon, and the higher the flight altitude, the less the distortion phenomenon. We also proposed a method to reduce distortion of orthoimage by lowering the resolution of original image using DTM (Digital Terrain Model) to improve distortion. Future high-quality unmanned aerial vehicles without distortions will contribute greatly to the application of UAV in the field of precision surveying.

Performance Comparison of Matching Cost Functions for High-Quality Sea-Ice Surface Model Generation (고품질 해빙표면모델 생성을 위한 정합비용함수의 성능 비교 분석)

  • Kim, Jae-In;Kim, Hyun-Cheol
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1251-1260
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    • 2018
  • High-quality sea-ice surface models generated from aerial images can be used effectively as field data for developing satellite-based remote sensing methods but also as analysis data for understanding geometric variations of Arctic sea-ice. However, the lack of texture information on sea-ice surfaces can reduce the accuracy of image matching. In this paper, we analyze the performance of matching cost functions for homogeneous sea-ice surfaces as a part of high-quality sea-ice surface model generation. The matching cost functions include sum of squared differences (SSD), normalized cross-correlation (NCC), and zero-mean normalized cross-correlation (ZNCC) in image domain and phase correlation (PC), orientation correlation (OC), and gradient correlation (GC) in frequency domain. In order to analyze the matching performance for texture changes clearly and objectively, a new evaluation methodology based on the principle of object-space matching technique was introduced. Experimental results showed that it is possible to secure reliability and accuracy of image matching only when optimal search windows are variably applied to each matching point in textureless regions such as sea-ice surfaces. Among the matching cost functions, NCC and ZNCC showed the best performance for texture changes.

Accuracy Analysis of Low-cost UAV Photogrammetry for Road Sign Positioning (드론사진측량에 의한 도로표지 위치정보 정확도 평가)

  • Sung, Hongki;Chong, Kyusoo;Lee, Chang No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.4
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    • pp.243-251
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    • 2019
  • The road sign location information installed on national roads is continuously updated using MMS (Mobile Mapping System) technology. It is possible to map accurate road facilities by MMS, but the equipment is very expensive and requires specialized technology. Also, the accuracy of the position of the object greatly depends on the GPS (Global Positioning System) accuracy. In the case of road facility mapping, the advantage of drone is more remarkable than that of field survey or conventional aerial photogrammetry. In particular, it is more efficient than field surveying and it is possible to acquire high resolution images with low budget compared to conventional aerial photogrammetry. In this study, the accuracy of the location information measured by the existing MMS is compared with the GPS survey result and the accuracy analysis is performed by the drone aerial photogrammetry. In order to confirm the space accuracy that can be obtained when conducting drone aerial photogrammetry, the accuracy of the change in the number of ground control points and the degree of overlap was evaluated. As a result of the experiment, it was possible to obtain sufficient accuracy with two ground control points distributed at both ends of the road and 60% overlap.

Comparative Experiment of 2D and 3D DCT Point Cloud Compression (2D 및 3D DCT를 활용한 포인트 클라우드 압축 비교 실험)

  • Nam, Kwijung;Kim, Junsik;Han, Muhyen;Kim, Kyuheon;Hwang, Minkyu
    • Journal of Broadcast Engineering
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    • v.26 no.5
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    • pp.553-565
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    • 2021
  • Point cloud is a set of points for representing a 3D object, and consists of geometric information, which is 3D coordinate information, and attribute information, which is information representing color, reflectance, and the like. In this way of expressing, it has a vast amount of data compared to 2D images. Therefore, a process of compressing the point cloud data in order to transmit the point cloud data or use it in various fields is required. Unlike color information corresponding to all 2D geometric information constituting a 2D image, a point cloud represents a point cloud including attribute information such as color in only a part of the 3D space. Therefore, separate processing of geometric information is also required. Based on these characteristics of point clouds, MPEG under ISO/IEC standardizes V-PCC, which imitates point cloud images and compresses them into 2D DCT-based 2D image compression codecs, as a compression method for high-density point cloud data. This has limitations in accurately representing 3D spatial information to proceed with compression by converting 3D point clouds to 2D, and difficulty in processing non-existent points when utilizing 3D DCT. Therefore, in this paper, we present 3D Discrete Cosine Transform-based Point Cloud Compression (3DCT PCC), a method to compress point cloud data, which is a 3D image by utilizing 3D DCT, and confirm the efficiency of 3D DCT compared to V-PCC based on 2D DCT.

Indoor Positioning System using Geomagnetic Field with Recurrent Neural Network Model (순환신경망을 이용한 자기장 기반 실내측위시스템)

  • Bae, Han Jun;Choi, Lynn;Park, Byung Joon
    • The Journal of Korean Institute of Next Generation Computing
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    • v.14 no.6
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    • pp.57-65
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    • 2018
  • Conventional RF signal-based indoor localization techniques such as BLE or Wi-Fi based fingerprinting method show considerable localization errors even in small-scale indoor environments due to unstable received signal strength(RSS) of RF signals. Therefore, it is difficult to apply the existing RF-based fingerprinting techniques to large-scale indoor environments such as airports and department stores. In this paper, instead of RF signal we use the geomagnetic sensor signal for indoor localization, whose signal strength is more stable than RF RSS. Although similar geomagnetic field values exist in indoor space, an object movement would experience a unique sequence of the geomagnetic field signals as the movement continues. We use a deep neural network model called the recurrent neural network (RNN), which is effective in recognizing time-varying sequences of sensor data, to track the user's location and movement path. To evaluate the performance of the proposed geomagnetic field based indoor positioning system (IPS), we constructed a magnetic field map for a campus testbed of about $94m{\times}26$ dimension and trained RNN using various potential movement paths and their location data extracted from the magnetic field map. By adjusting various hyperparameters, we could achieve an average localization error of 1.20 meters in the testbed.

Development of IFC Standard for Securing Interoperability of BIM Data for Port Facilities (항만 BIM 데이터의 상호운용성 확보를 위한 IFC 표준 개발)

  • Moon, Hyoun-Seok;Won, Ji-Sun;Shin, Jae-Young
    • Journal of KIBIM
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    • v.10 no.1
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    • pp.9-22
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    • 2020
  • Recently, BIM has been extended to infrastructures such as roads and bridges, and the demand for BIM standard development for ports is increasing internationally. Due to the low level of utilization of classification system and drawing standards compared to other infrastructures, and the closed nature of national security facilities, ports have insufficient level of connection and sharing environment among external systems or users. In addition, since the standardization of data for port facilities is not made, it is still necessary to establish an independent DB for each system and to ensure interoperability of data between these systems since it does not have a shared environment among similar data. Therefore, the purpose of this study is to develop and verify IFC, the international standard for BIM, in order to cope with the BIM environment and to be commonly used in the design, construction, and maintenance of port facilities. To this end, we build a standard schema with port-specific Express Notation according to buildingSMART International's standard development methodology. First, domestic and international reference model standards were analyzed to derive components such as space and facilities of port facilities. Based on this, the components of the port facility were derived through the codification, categorization, and normalization process developed by the research team. This was extended based on the port BIM object classification system developed by the research team. Normalization results were verified by designers and associations. Then, IFC schema construction was based on Express-G data modeling based on IFC 4 * 2 Candidate, which is a bridge candidate standard based on IFC4 (ISO16739), and IFC 4 * 3 Draft, which is developed by buildingSMART International. The final schema was validated using the commercialized validation tool. In addition, in order to verify the structural verification of the port IFC schema, the transformation process was verified by converting the caisson model into a Part21 file. In the future, this result will not only be used as a delivery standard for port BIM products, but will also be applied as a linkage standard between systems and a common data format for port BIM platforms when BIM is used in the maintenance phase. In particular, it is expected to be used as a core standard for data exchange in the port maintenance stage.

Research on the Creative Style of DreamWorks' Animated Film Script (드림웍스 애니메이션 영화 시나리오의 창작 스타일에 관한 연구)

  • Yan, Liu
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.1
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    • pp.97-106
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    • 2020
  • The mainstream of cinema animated film in today's world is the animated film produced by film companies such as Disney, DreamWorks, and 20th Century Fox. These animated films are influenced by Hollywood blockbusters, high cost, and big-budget, which have brought a gorgeous and splendid audio-visual feast to the global audience. DreamWorks Studios founded in 1994 has become noted in just over ten years. It has produced many high-quality animated works which are well-known all over the world. This achievement is no doubt inseparable from its superior external animation industry environment, and benefited from the American animation industry which commercially operated for almost 100 years. However, in addition to these external environmental factors, DreamWorks' achievements have also come from the extraordinary and superior creation of the animated film scripts, strong narrative script ensures the logic and appeal of animated films. This article takes Kung Fu Panda series, Shrek series, The Prince of Egypt, The Croods, Chicken Run, Megamind and other representative films produced by DreamWorks as key analysis object, using Jean Baudrillard's simulation and imaging theory, Syd Field's screenwriting skills, and Hegel's aesthetic point of view, explores the Creative Style of DreamWorks' Animated Film Script which contains the following four aspects. The script is exaggerated and novel, and the subject matter is rich and targeted. The script creation is very imaginative and can fully express the visual beauty. The structure of the story is well controlled, the space comes from reality but full of imagination. The characters have distinctive personality and the dialogue is moderated but forceful.

KOMPSAT Image Processing and Application (다목적실용위성 영상처리 및 활용)

  • Lee, Kwang-Jae;Kim, Ye-Seul;Chae, Sung-Ho;Oh, Kwan-Young;Lee, Sun-Gu
    • Korean Journal of Remote Sensing
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    • v.38 no.6_4
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    • pp.1871-1877
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    • 2022
  • In the past, satellite development required enormous budget and time, so only some developed countries possessed satellites. However, with the recent emergence of low-budget satellites such as micro-satellites, many countries around the world are participating in satellite development. Low-orbit and geostationary-orbit satellites are used in various fields such as environment and weather monitoring, precise change detection, and disasters. Recently, it has been actively used for monitoring through deep learning-based object-of-interest detection. Until now, Korea has developed satellites for national demand according to the space development plan, and the satellite image obtained through this is used for various purpose in the public and private sectors. Interest in satellite image is continuously increasing in Korea, and various contests are being held to discover ideas for satellite image application and promote technology development. In this special issue, we would like to introduce the topics that participated in the recently held 2022 Satellite Information Application Contest and research on the processing and utilization of KOMPSAT image data.

A Comparison of Pre-Processing Techniques for Enhanced Identification of Paralichthys olivaceus Disease based on Deep Learning (딥러닝 기반 넙치 질병 식별 향상을 위한 전처리 기법 비교)

  • Kang, Ja Young;Son, Hyun Seung;Choi, Han Suk
    • The Journal of the Korea Contents Association
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    • v.22 no.3
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    • pp.71-80
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    • 2022
  • In the past, fish diseases were bacterial in aqua farms, but in recent years, the frequency of fish diseases has increased as they have become viral and mixed. Viral diseases in an enclosed space called a aqua farm have a high spread rate, so it is very likely to lead to mass death. Fast identification of fish diseases is important to prevent group death. However, diagnosis of fish diseases requires a high level of expertise and it is difficult to visually check the condition of fish every time. In order to prevent the spread of the disease, an automatic identification system of diseases or fish is needed. In this paper, in order to improve the performance of the disease identification system of Paralichthys olivaceus based on deep learning, the existing pre-processing method is compared and tested. Target diseases were selected from three most frequent diseases such as Scutica, Vibrio, and Lymphocystis in Paralichthys olivaceus. The RGB, HLS, HSV, LAB, LUV, XYZ, and YCRCV were used as image pre-processing methods. As a result of the experiment, HLS was able to get the best results than using general RGB. It is expected that the fish disease identification system can be advanced by improving the recognition rate of diseases in a simple way.

A study on coding mathematics curriculum and teaching methods that converges school mathematics and school informatics (수학교과와 정보교과를 융합하는 코딩수학 교육과정 및 교육방법 연구)

  • Kang, Ha Ram;Lim, Chae Lyeong;Cho, Han Hyuk
    • The Mathematical Education
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    • v.60 no.4
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    • pp.467-491
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    • 2021
  • This study is a study on the coding mathematics curriculum that converges elementary and middle school mathematics and information subjects and a minimum coding game-based education method for this. For the past 3 years, the coding mathematics curriculum and educational methods to effectively operate the curriculum were studied by applying them to 6th graders of elementary school and 1st graders of middle school. As a result of the first year of research, the coding mathematics curriculum was modified to a coding environment including the mathematical concept of a three-dimensional coordinate space, and the three-dimensional object was improved to be output as a real 3D print. As a result of the 2nd year study, it was improved so that even low-level students can build buildings by introducing different level commands for each component of the building so that self-directed learning is possible. As a result of the 3rd year study, a teaching-learning strategy based on a minimal coding game was designed to induce an increase in the level of computational thinking, and evaluation and feedback for diagnosing computational thinking were developed. Educational methods to promote self-directed learning and computing thinking ability, and researched coding mathematics curriculum are meaningful for the research and practice of the convergence education of school mathematics and informatics.