• Title/Summary/Keyword: Flight Height

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Measurement Method of Airburst Height Using the Approach Angle (비행체 진입각을 이용한 공중 폭발고도 계측 방법)

  • Kim, Jinho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.4
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    • pp.497-504
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    • 2017
  • This paper proposes a method to measure the airburst height by utilizing a high speed camera. This method might be applied to the test of which flight target is alive after the burst. The proposed method consists of four main steps. The first step is to compute the impact point using the sea surface height. The second step is to compute the height of burst (HOB) by using the distance from the camera to the impact point. This could be different from the real explosion height. That is because the distance from the camera to the burst point is not the same as it from the camera to the impact point. Therefore, the third step is to calculate the approach angle of the flight target with respect to the installed camera. Then, the last step is to compensate the computed height by using the approach angle. The result of the proposed method is compared with it from the triangulation. In this paper, the HOB error is also analyzed regarding the approach angle difference. Based on this analysis, the camera position might be suggested for error reduction.

Feasibility of a New Vault Technique through Kinematic Analysis of Yeo 2 and YANG Hak Seon Vaults

  • Song, Joo-Ho;Park, Jong-Hoon;Kim, Jin-Sun
    • Korean Journal of Applied Biomechanics
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    • v.28 no.2
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    • pp.69-78
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    • 2018
  • Objective: The purpose of this study was to investigate the feasibility of a new vault technique through a kinematic comparison of the YANG Hak Seon and Yeo 2 vaults. Method: The photographic images of the YANG Hak Seon and Yeo 2 vaults were collected using a high-speed camera, and their kinematic characteristics were analyzed using three-dimensional image analysis. Results: During the post-flight phase of the Yeo 2 and YANG Hak Seon vaults, the time of flight, height of flight, and flight distance were similar. At the peak of the post-flight phase, the trunk rotation angle of the YANG Hak Seon vault rotated $457^{\circ}$ more than did the Yeo 2 vault. During the post-flight descending period, the twist velocity of the trunk was much faster with the YANG Hak Seon vault ($1,278^{\circ}/s$) than with the Yeo 2 vault ($1,016^{\circ}/s$). Conclusion: To succeed in the new technique, the average twist velocity during post-flight must be maintained at $1,058^{\circ}/s$ and the twist velocity must be increased from the ascending phase.

Pattern Analysis and Determination of Body Dimension for Flight Suit Design (비행복 설계를 위한 패턴 분석 및 인체치수 설정)

  • Jeon, Eun-Jin;Park, Ji-Eun;Jeong, Jeong-Rim;Park, Sei-Kwon;Park, Jang-Un;You, Hee-Cheon;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.11 no.2
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    • pp.286-292
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    • 2009
  • The purpose of this study is to analyze the pattern of the present flight suit, to select variables of human body and key dimensions for making pattern of the flight suit, and to decide the most appropriate size of human body and rate of ease for designing an overall flight suit. For analyzing the pattern of flight suit, we used "M95Special" (men ; chest circumference 92-97 cm ; height : above 177 cm), which was indicated as the standard of the Ministry of National Defense. We analyzed general appearance and the actual dimensions of the pattern of the flight suit. As a result of analyzing the pattern, flight suit was front-opened overall style which had a flat collar with rounded edges, two-pieced sleeves with lower height of the sleeve's cap, 3cm-width belt on the waist and 8 pockets. To decide the most appropriate size of human body, we selected 20 variables of human body in the 359 variables of the Size Korea by referring the previous studies. The 20 variables of human body were 9 circumferences (chest, waist, hip, neck, armscye, wrist, thigh, knee, and ankle), 9 lengths (stature, back interscye fold, waist back, crotch height, crotch, body rise, arm, outside leg and total), and 2 breadths (biacromial and chest). We drew out the size of 20 variables from the Size Korea and US Army anthropometry data and decided the most appropriate values from the drawn data for applying to the pattern of flight suit.

Drone Image Quality Analysis According to Flight Plan

  • Park, Joon Kyu;Lee, Keun Wang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.2
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    • pp.81-91
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    • 2021
  • Drone related research has been increasing recently due to the development and distribution of commercial unmanned aerial vehicles. However, most of the previous studies focused on the accuracy and utility of drone surveying. For drones, the resolution of the result is determined according to the flight altitude, but since 70% of Korea is mountainous, it is necessary to analyze the quality of the drone image according to the flight plan. In this study, the quality of drone photogrammetry results according to flight plans was analyzed. The flight plan was established by fixed altitude and considering the height of the terrain. Images were acquired for both cases and data was processed to generate ortho images. As a result of evaluating the accuracy of the generated ortho image, the accuracy was found to be -0.07 ~ 0.09m. The accuracy of Case I and Case II did not show a significant difference, but for RMSE, Case I showed a good value. These results indicate that the drone flight plan affects the quality of the results. Also, when flying at a fixed altitude, II showed a lower value than the originally set overlap according to the altitude of the object. In future surveys using drones, flight planning taking into account the height of the object will contribute to the improvement of the quality of the results.

Implementation of Altitude Information for Flight Simulator in OpenSceneGraph (항공 시뮬레이터를 위한 OpenSceneGraph기반의 고도 정보 구현 방안)

  • Lee, ChungJae;Kim, JongBum;Kim, Ki-Il
    • IEMEK Journal of Embedded Systems and Applications
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    • v.9 no.1
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    • pp.11-16
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    • 2014
  • When it comes to develop flight simulator, HAT (Height Above Terrain) is required to provide altitude information to the pilot who learns how to control an airplane in landing and takeoff situation. However, there might be inconsistent problem between real terrain and simulation information since current implementation of HAT simply depends on center of gravity point on the airplane. To overcome mentioned problem, in this paper, we propose how to obtain more accurate altitude information than existing scheme by making use of HAT and HOT (Height Of Terrain) information of landing equipments according to movement of the airplane. Moreover, we demonstrate the accuracy of the proposed scheme through new flight simulator developed through OSG(OpenSceneGraph) by taking example of terrain information for domestic airport.

Effects of wind direction on the flight trajectories of roof sheathing panels under high winds

  • Kordi, Bahareh;Traczuk, Gabriel;Kopp, Gregory A.
    • Wind and Structures
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    • v.13 no.2
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    • pp.145-167
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    • 2010
  • By using the 'failure' model approach, the effects of wind direction on the flight of sheathing panels from the roof of a model house in extreme winds was investigated. A complex relationship between the initial conditions, failure velocities, flight trajectories and speeds was observed. It was found that the local flow field above the roof and in the wake of the house have important effects on the flight of the panels. For example, when the initial panel location is oblique to the wind direction and in the region of separated flow near the roof edge, the panels do not fly from the roof since the resultant aerodynamic forces are small, even though the pressure coefficients at failure are high. For panels that do fly, wake effects from the building are a source of significant variation of flight trajectories and speeds. It was observed that the horizontal velocities of the panels span a range of about 20% - 95% of the roof height gust speed at failure. Numerical calculations assuming uniform, smooth flow appear to be useful for determining panel speeds; in particular, using the mean roof height, 3 sec gust speed provides a useful upper bound for determining panel speeds for the configuration examined. However, there are significant challenges for estimating trajectories using this method.

A Development of the Program for Flight Suitability Distinction and Calculation of Available Sorties (비행 적합성 판별 및 소티수 산출 프로그램 개발)

  • Kim, Young-Rae;Lee, Sang-Chul;Lee, Jin-Sub;Ryu, Kwang-Su
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.19 no.4
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    • pp.105-110
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    • 2011
  • The flight test comes at the end of the aircraft development process and is an unique part. The purposes of the flight test are to evaluate the characteristics of the aircraft and validate its design in the real operating environment. Atmospheric considerations are key elements, when the planner of flight test establishes the flight test planning. The primary objective of atmospheric considerations is to ensure safety of the vehicle. The planning through atmospheric considerations can minimize flight cancellations caused by severe weather. In this paper, we present a program for flight suitability distinction, and develop a program for calculation of available sorties.

A Data Gathering Approach for Wireless Sensor Network with Quadrotor-based Mobile Sink Node

  • Chen, Jianxin;Chen, Yuanyuan;Zhou, Liang;Du, Yuelin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2529-2547
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    • 2012
  • In this paper, we use a quadrotor-based mobile sink to gather sensor data from the terrestrial deployed wireless sensor network. By analyzing the flight features of the mobile sink node, we theoretically study the flight constraints of height, velocity, and trajectory of the mobile sink node so as to communicate with the terrestrial wireless sensor network. Moreover, we analyze the data amount which the mobile sink can send when it satisfies these flight constraints. Based on these analysis results, we propose a data acquisition approach for the mobile sink node, which is discussed detailed in terms of network performance such as the transmission delay, packet loss rate, sojourning time and mobile trajectory when given the flying speed and height of the mobile sink node. Extensive simulation results validate the efficiency of the proposed scheme.

Parameter identification of the nonlinear stall motion from flight test data (비행시험을 통한 항공기의 비선형 실속 운동시의 매개변수 추정)

  • 전일환;황명신;이정훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.199-202
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    • 1996
  • In this paper, we used the maximum likelihood method for 2-point aerodynamic model to determine the parameters of the ChangGong-91. Since the estimation from the flight test of real aircraft is the most reliable, we performed the flight test of ChangGong-91 to get the parameters such as velocity, height, 3 axis acceleration, 3 axis angular rate, pitch angle, angle of attack, temperature and so on. We recorded the flight test data in S-VHS tapes and stored them to personal computer using A/D(analog to digital) converter. Flight test was done in stall motion, and the acquired data was be processed with parameter identification method.

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Simulation of the control force of the light aircraft using flight test data (비행시험 자료를 이용한 경항공기의 조종력 시뮬레이션)

  • 김정환;황명신;이정훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.203-206
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    • 1996
  • The purpose of this paper is to find how to determine the parameters of the basic control system design such as hinge moment coefficients and to display the controllability of the ChangCong-91. Since the estimation from the flight test of real aircraft is the most reliable, we performed the flight test of ChangGong-91 to get the various parameters such as velocity, height, control force, control surface deflection, 3 axis acceleration, 3 axis angular rate, pitch angle, angle of attack temperature and so on. We recorded the flight test data in VHS tapes and stored them to personal computer using A/D(analog to digital) converter. Flight test was done in various conditions, and the acquired data was processed with parameter identification method such as least square method. These data will be utilized for the development of Autopilot System design and Control Loading System design.

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