• Title/Summary/Keyword: time-of-flight

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Disaster Documentation through Oral History : Focus on Sinking of the MV Sewol (구술을 통한 재난 사고의 기록화 세월호 참사 관련 구술을 중심으로)

  • Song, Zoo Hyung
    • The Korean Journal of Archival Studies
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    • no.44
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    • pp.155-197
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    • 2015
  • Disaster of Sewol took place in one year. Meanwhile, the victim's family and the call time record academics have tried to record it. Ansan activists have moved to objectives such as civil records committee also pivotal. The citizens committee under the dictation recording oral history team has a diverse group of people associated with the time issue. bereaved families were collected from the oral as well as volunteers, religious personnel, activists, Ansan citizens and various people. Disasters around the world is also an important event to remember and honor the people together, and one of the most effective means to record There it is establishing an oral history archive. Does not leave a lot of nature history of sudden disasters that occur, as well as a tribute record dictation telling people of diverse perspectives on events helps a lot closer to the reality of the event. Erected in the National September 11 Memorial Museum to honor the Sept. 11 attacks and provide a variety of programs to chaerok dictation of the people involved with 9/11. To remember the 2013 Boston Marathon bombing 'Our Marathon' of crowdsourcing digital archive was built. In the archives of the local universities and institutions were created to collaborate actively and gathering oral history. Pan Am Flight 103 pieces terror has established an archive from Syracuse University. Here, neither graduates, faculty, and to the victim's family and friends gather and oral hitory. Disaster-related Sewol neither should be able to be used as in the case of foreign well, and it should continue to honor the victims of the collection. It also ought to occasion again to avoid this disaster on earth.

Individual Ortho-rectification of Coast Guard Aerial Images for Oil Spill Monitoring (유출유 모니터링을 위한 해경 항공 영상의 개별정사보정)

  • Oh, Youngon;Bui, An Ngoc;Choi, Kyoungah;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1479-1488
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    • 2022
  • Accidents in which oil spills occur intermittently in the ocean due to ship collisions and sinkings. In order to prepare prompt countermeasures when such an accident occurs, it is necessary to accurately identify the current status of spilled oil. To this end, the Coast Guard patrols the target area with a fixed-wing airplane or helicopter and checks it with the naked eye or video, but it was difficult to determine the area contaminated by the spilled oil and its exact location on the map. Accordingly, this study develops a technology for direct ortho-rectification by automatically geo-referencing aerial images collected by the Coast Guard without individual ground reference points to identify the current status of spilled oil. First, meta information required for georeferencing is extracted from a visualized screen of sensor information such as video by optical character recognition (OCR). Based on the extracted information, the external orientation parameters of the image are determined. Images are individually orthorectified using the determined the external orientation parameters. The accuracy of individual orthoimages generated through this method was evaluated to be about tens of meters up to 100 m. The accuracy level was reasonably acceptable considering the inherent errors of the position and attitude sensors, the inaccuracies in the internal orientation parameters such as camera focal length, without using no ground control points. It is judged to be an appropriate level for identifying the current status of spilled oil contaminated areas in the sea. In the future, if real-time transmission of images captured during flight becomes possible, individual orthoimages can be generated in real time through the proposed individual orthorectification technology. Based on this, it can be effectively used to quickly identify the current status of spilled oil contamination and establish countermeasures.

Performance Evaluation of Hydrogen Generation System using NaBH4 Hydrolysis for 200 W Fuel Cell Powered UAV (200 W급 연료전지 무인기를 위한 NaBH4 가수분해용 수소발생시스템의 성능평가)

  • Oh, Taek-Hyun;Kwon, Sejin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.4
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    • pp.296-303
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    • 2015
  • The concentration of solute in a $NaBH_4$ solution is limited due to the low solubility of $NaBO_2$. The performance of a hydrogen generation system was evaluated using various concentrations of $NaBH_4$ solution. First, a self-hydrolysis test and a hydrogen generation test for 30 min were performed. The composition of $NaBH_4$ solution was selected to be 1 wt% NaOH + 25 wt% $NaBH_4$+74wt% $H_2O$ by considering the amount of hydrogen loss, stability of hydrogen generation, $NaBO_2$ precipitation, conversion efficiency, and the purpose of its application. A hydrogen generation system for a 200 W fuel cell was evaluated for 3 h. Although hydrogen generation rate decreased with time due to $NaBO_2$ precipitation, hydrogen was produced for 3 h (conversion efficiency: 87.4%). The energy density of the 200 W fuel cell system was 263 Wh/kg. A small unmanned aerial vehicle with this fuel cell system can achieve 1.5 times longer flight time than one flying on batteries.

Evaluation of Possibility of Large-scale Digital Map through Precision Sensor Modeling of UAV (무인항공기 정밀 센서모델링을 통한 대축척 수치도화 가능성 평가)

  • Lim, Pyung-chae;Kim, Han-gyeol;Park, Jimin;Rhee, Sooahm
    • Korean Journal of Remote Sensing
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    • v.36 no.6_1
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    • pp.1393-1405
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    • 2020
  • UAV (Unmanned Aerial Vehicle) can acquire high-resolution images due to low-altitude flight, and it can be photographed at any time. Therefore, the UAV images can be updated at any time in map production. Due to these advantages, studies on the possibility of producing large-scale digital maps using UAV images are actively being conducted. Precise digital maps can be used as base data for digital twins or smart cites. For producing a precise digital map, precise sensor modeling using GCPs (Ground Control Points) must be preceded. In this study, geometric models of UAV images were established through a precision sensor modeling algorithm developed in house. Then, a digital map by stereo plotting was produced to evaluate the possibility of large-scale digital map. For this study, images and GCPs were acquired for Ganseok-dong, Incheon and Yeouido, Seoul. As a result of precision sensor modeling accuracy analysis, high accuracy was confirmed within 3 pixels of the average error of the checkpoints and 4 pixels of the RMSE was confirmed for the two study regions. As a result of the mapping accuracy analysis, it satisfied the 1:1,000 mapping accuracy announced by the NGII (National Geographic information Institute). Therefore, the precision sensor modeling technology suggested the possibility of producing a 1:1,000 large-scale digital map by UAV images.

A study on the development of surveillance system for multiple drones in school drone education sites (학내 드론 교육현장의 다중드론 감시시스템 개발에 관한 연구)

  • Jin-Taek Lim;Sung-goo Yoo
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.697-702
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    • 2023
  • Recently, with the introduction of drones, a core technology of the 4th industrial revolution, various convergence education using drones is being conducted in school education sites. In particular, drone theory and practice education is being conducted in connection with free semester classes and career exploration. The drone convergence education program has higher learner satisfaction than simple demonstration and practice education, and the learning effect is high due to direct practical experience. However, since practical education is being conducted for a large number of learners, it is impossible to restrict and control the flight of a large number of drones in a limited place. In this paper, we propose a monitoring system that allows the instructor to monitor multiple drones in real time and learners to recognize collisions between drones in advance when multiple drones are operated, focusing on education operated in schools. The communication module used in the experiment was equipped with GPS in Murata LoRa, and the server and client were configured to enable monitoring based on the location data received in real time. The performance of the proposed system was evaluated in an open space, and it was confirmed that the communication signal was good up to a distance of about 120m. In other words, it was confirmed that 25 educational drones can be controlled within a range of 240m and the instructor can monitor them.

Intraspecies Volatile Interactions Affect Growth Rates and Exometabolomes in Aspergillus oryzae KCCM 60345

  • Singh, Digar;Lee, Choong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.199-209
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    • 2018
  • Volatile organic compounds (VOCs) are increasingly been recognized as the chemical mediators of mold interactions, shaping their community dynamics, growth, and metabolism. Herein, we selectively examined the time-correlated (0 D-11 D, where D = incubation days) effects of intraspecies VOC-mediated interactions (VMI) on Aspergillus oryzae KCCM 60345 (S1), following co-cultivation with partner strain A. oryzae KACC 44967 (S2), in a specially designed twin plate assembly. The comparative evaluation of $S1_{VMI}$ (S1 subjected to VMI with S2) and its control ($S1_{Con}$) showed a notable disparity in their radial growth ($S1_{VMI}$ < $S1_{Con}$) at 5 D, protease activity ($S1_{VMI}$ > $S1_{Con}$) at 3-5 D, amylase activity ($S1_{VMI}$ < $S1_{Con}$) at 3-5 D, and antioxidant levels ($S1_{VMI}$ > $S1_{Con}$) at 3 D. Furthermore, we observed a distinct clustering pattern for gas chromatography-time of flight-mass spectrometry datasets from 5 D extracts of $S1_{VMI}$ and $S1_{Con}$ in principle component analysis (PC1: 30.85%; PC2: 10.31%) and partial least squares discriminant analysis (PLS-DA) (PLS1: 30.77; PLS2: 10.15%). Overall, 43 significantly discriminant metabolites were determined for engendering the metabolic variance based on the PLS-DA model (VIP > 0.7, p < 0.05). In general, a marked disparity in the relative abundance of amino acids ($S1_{VMI}$ > $S1_{Con}$) at 5 D, organic acids ($S1_{VMI}$ > $S1_{Con}$) at 5 D, and kojic acid ($S1_{VMI}$ < $S1_{Con}$) at 5-7 D were observed. Examining the headspace VOCs shared between S1 and S2 in the twin plate for 5 D incubated samples, we observed the relatively higher abundance of C-8 VOCs (1-octen-3-ol, (5Z)-octa-1,5-dien-3-ol, 3-octanone, 1-octen-3-ol acetate) having known semiochemical functions. The present study potentially illuminates the effects of VMI on commercially important A. oryzae's growth and biochemical phenotypes with subtle details of altered metabolomes.

GPU-only Terrain Rendering for Walk-through (Walk-through를 지원하는 GPU 기반 지형렌더링)

  • Park, Sun-Yong;Oh, Kyoung-Su;Cho, Sung-Hyun
    • Journal of Korea Game Society
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    • v.7 no.4
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    • pp.71-80
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    • 2007
  • In this paper, we introduce an efficient GPU-based real-time rendering technique applicable to every kind of game. Our method, without an extra geometry, can represent terrain just with a height map. It makes it possible to freely go around in the air or on the surface, so we can directly apply it to any computer games as well as a virtual reality. Since our method is not based on any geometrical structure, it doesn't need special LOD policy and the precision of geometrical representation and visual quality absolutely depend on the resolution of height map and color map. Moreover, GPU-only technique allows the general CPU to be dedicated to more general work, and as a result, enhances the overall performance of the computer. To date, there have been many researches related to the terrain representation, but most of them rely on CPU or confmed its applications to flight simulation, Improving existing displacement mapping techniques and applying it to our terrain rendering, we completely ruled out the problems, such as cracking, poping etc, which cause in polygon-based techniques, The most important contributions are to efficiently deal with arbitrary LOS(Line Of Sight) and dramatically improve visual quality during walk-through by reconstructing a height field with curved patches. We suggest a simple and useful method for calculating ray-patch intersections. We implemented all these on GPU 100%, and got tens to hundreds of framerates with height maps a variety of resolutions$(256{\times}256\;to\;4096{\times}4096)$.

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Application of neural network for airship take-off and landing mode by buoyancy control (기낭 부력 제어에 의한 비행선 이착륙의 인공신경망 적용)

  • Chang, Yong-Jin;Woo, Gui-Ae;Kim, Jong-Kwon;Lee, Dae-Woo;Cho, Kyeum-Rae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.2
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    • pp.84-91
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    • 2005
  • For long time, the takeoff and landing control of airship was worked by human handling. With the development of the autonomous control system, the exact controls during the takeoff and landing were required and lots of methods and algorithms were suggested. This paper presents the result of airship take-off and landing by buoyancy control using air ballonet volume change and performance control of pitch angle for stable flight within the desired altitude. For the complexity of airship's dynamics, firstly, simple PID controller was applied. Due to the various atmospheric conditions, this controller didn't give satisfactory results. Therefore, new control method was designed to reduce rapidly the error between designed trajectory and actual trajectory by learning algorithm using an artificial neural network. Generally, ANN has various weaknesses such as large training time, selection of neuron and hidden layer numbers required to deal with complex problem. To overcome these drawbacks, in this paper, the RBFN (radial basis function network) controller developed. The weight value of RBFN is acquired by learning which to reduce the error between desired input output through and airship dynamics to impress the disturbance. As a result of simulation, the controller using the RBFN is superior to PID controller which maximum error is 15M.

Comparative Analysis of Focal Length Bias for Three Different Line Scanners (초점거리 편의가 지상 정확도에 미치는 영향 비교 연구 - 세가지 라인 스캐너를 대상으로 -)

  • Kim, Changjae
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.4_1
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    • pp.363-371
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    • 2014
  • Most space-borne optical scanning systems adopt linear arrayconfigurations. The well-knownthree different types of space-borne sensors arealong-track line scanner, across-track linescanner, and three line scanner. To acquire accurate location information of an object on the ground withthose sensors, the exterior and interior orientation parameters are critical factors for both of space-borne and airborne missions. Since the imaging geometry of sensors mightchange time to time due to thermal influence, vibration, and wind, it is very important to analyze the Interior Orientation Parameters (IOP) effects on the ground. The experiments based on synthetic datasets arecarried out while the focal length biases are changing. Also, both high and low altitudes of the imagingsensor were applied. In case with the along-track line scanner, the focal length bias caused errors along the scanline direction. In the other case with the across-track one, the focal length bias caused errors alongthe scan line and vertical directions. Lastly, vertical errors were observed in the case ofthree-line scanner. Those results from this study will be able to provide the guideline for developing new linearsensors, so as for improving the accuracy of laboratory or in-flight sensor calibrations.

Improvement of Transfer Alignment Performance for Airborne EOTS (항공용 전자광학추적장비의 전달정렬 성능 개선)

  • Kim, Minsoo;Lee, Dogeun;Jeong, Chiun;Jeong, Jihee
    • Journal of Aerospace System Engineering
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    • v.16 no.4
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    • pp.60-67
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    • 2022
  • An Electro-Optical Tracking System (EOTS) is an electric optical system with EO/IR cameras, laser sensors, and an IMU. The EOTS calculates coordinates of targets, using attitude and acceleration measured by the IMU. In particular for an armed aircraft, the performance of the weapon system depends on how quickly and accurately it acquires the target coordinates. The IMU should be operated after alignment is complete, to meet the coordinate accuracy required by the weapon system so the initial stabilization time of the IMU should be reduced, by quickly measuring the attitude and acceleration. Alignment is the process of determining the initial attitude by resolving the attitude error of the IMU, and the IMU of mission equipment such as an airborne EOTS, uses velocity matching based on the velocity from GPS/INS for aircraft navigation. In this paper, a method is presented to improve the transfer alignment performance of the airborne EOTS, by maneuvering aircraft and the mission equipment. First, the performance factor of the alignment was identified, as a heading error through the velocity matching model and simulation results. Then acceleration maneuvers and attitude changes were necessary, to correct the error. As a result of flight tests applied to an EOTS on a OOO aircraft system, the transfer alignment performance was improved as the duration time was decreased, by more than five times when the aircraft accelerated by more than 0.2g and the EOTS was moving until 6.7deg/s.