• Title/Summary/Keyword: Flight Phase

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Impact Point Prediction of the Ballistic Target Using a Flight Phase Discrimination (비행단계 식별 알고리즘을 이용한 초고속 표적의 탄착점 예측)

  • Jung, JaeKyung;Hwang, DongHwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.3
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    • pp.234-243
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    • 2015
  • It is required to have the capability to predict the impact point of the ballistic target in order to assign the firing unit with high engagement possibility for the interception in the ballistic target defense systems. In this paper, a novel method is proposed to predict the impact point of the ballistic target using a flight phase discrimination algorithm given the insufficient measurements on the partial trajectory. The flight of a ballistic target is composed of a boost phase and a ballistic phase with different dynamics. The flight phase is discriminated by using the normalized innovation distance between measurements and a priori estimated measurements. The threshold and tolerance in the flight phase discrimination are determined from the probabilistic characteristics of the estimation error. Monte Carlo simulations are performed to verify the proposed method.

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.

Kinematical analysis of Yurchenko Streched at Horse Vaulting (도마운동 유리첸코 몸 펴 공중돌기 동작의 운동학적 분석)

  • Yoon, Chang-Sun;Kim, Tae-Sam;Yoon, Hee-Joung
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.67-79
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    • 2003
  • The purpose of this study is to investigate the effective skill motion through the kinematic analysis of the Yurchenko Streched motion in new horse vaulting. The subjects in this study were 3 male gymnasts who were ranked as national athletes. After the 3D motion analysis, kinematic variables were analyzed to comparison with the difference between this study and the previous study(Yang, D. Y and Lee, C. S, 1999). As a result, the following conclusions was drawn; 1. In the board contact phase, this study showed a shorten contact time to maintain in condition highly extension of hip and hee angle than the previous study. 2. In the pre-flight phase, this study appeared more shortly flight duration time and horizontal flight displacement than the previous study. 3. In the horse contact phase, the contact duration time and horizontal displacement of COG shortened than the previous study, but appeared to the fast horizontal and vertical velocity and highly extension of shoulder an. 4. In the post-flight phase, a stable horse contact appeared to the increase of the flight duration time and the apex height during the post-flight. And it showed that these results have a stable and good landing.

Efficient Recognition Method for Ballistic Warheads by the Fusion of Feature Vectors Based on Flight Phase (비행 단계별 특성벡터 융합을 통한 효과적인 탄두 식별방법)

  • Choi, In-Oh;Kim, Si-Ho;Jung, Joo-Ho;Kim, Kyung-Tae;Park, Sang-Hong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.30 no.6
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    • pp.487-497
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    • 2019
  • It is very difficult to detect ballistic missiles because of small cross-sections of the radar and the high maneuverability of the missiles. In addition, it is very difficult to recognize and intercept warheads because of the existence of debris and decoy with similar motion parameters in each flight phase. Therefore, feature vectors based on the maneuver, the micro-motion according to flight phase are needed, and the two types of features must be fused for the efficient recognition of ballistic warhead regardless of the flight phase. In this paper, we introduce feature vectors appropriate for each flight phase and an effective method to fuse them at the feature vector-level and classifier-level. According to the classification simulations using the radar signals predicted by the CAD models, the closer the warhead was to the final destination, the more improved was the classification performance. This was achieved by the classifier-level fusion, regardless of the flight phase in a noisy environment.

Numerical Analysis on the Collision Behaviors of in-flight Droplets During Gas Atomization (가스 분무 시 비행 액적의 충돌 현상에 관한 수치적 고찰)

  • Seok, Hyun Kwang
    • Korean Journal of Metals and Materials
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    • v.46 no.8
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    • pp.506-515
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    • 2008
  • Recently, it is exceedingly required to produce metal powders with tailored shape and phase altogether in order to fabricate high performance functional parts such as magnetic core or electro-magnetic noise suppressor for high frequency usage. Therefore, the collision phenomena of in-flight droplets against chamber wall or neighboring in-flight droplets each other is investigated by a computational method in order to get useful information about how to design the atomizing system and how to tailor process parameters not to make irregular-shaped powders during gas atomization process. As a results, smaller powders, lower melt temperature are known to be favorable for droplets not to collide against chamber wall. In additions, powders of narrower size distribution range, lower droplet generation rate, lower melt temperature, lower gas velocity are desirable to prevent droplet-collisions against neighboring in-flight droplets.

The 2D/3D Time-of-Flight, Phase Contrast and Contrast Enhanced Magnetic Resonance Angiograph (2D/3D Time-of-Flight, Phase Contrast 그리고 Contrast Enhanced 자기 공명 혈관조영기법에 관한 연구)

  • Yi, Yun;Choi, Jung-Hwan;Park, Seung-Hun;Kim, Si-Seung;Chung, Sung-Taek
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.4
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    • pp.291-298
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    • 2003
  • It is important to visualize a lesion accurately in diagnosis of disease. Many diseases result in a change of lesion. Magnetic resonance angiography can visualize the morphological characteristics of blood vessel. The magnetic resonance angiography (MRA) can be categorized to time-of-flight, phase contrast, and contrast enhanced MRA. In this paper, we introduce a principle, sequence, and feature of angiography For better image quality we describe data processing methods and show several applications to human bodies

Exploratory Study on the Process and Checklist Items for Construction Safety Inspection Utilizing Drones

  • Jung, Jieun;Baek, Mina;Yu, Chaeyeon;Lee, Donghoon;Kim, Sungjin
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.3
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    • pp.327-336
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    • 2023
  • The focus of this research was to devise a conceptual methodology for drone usage and to assess the viability of safety checklist items specific to drone application in safety oversight. The appraisal was grounded in a focus group interview involving professionals from construction management and safety fields. The proposed process was segmented into four stages: 1) pre-flight phase for flight plan development, 2) drone flight phase for safety condition inspection utilizing checklist items, 3) post-flight phase for visual asset analysis, and 4) documentation and management phase. Furthermore, the research scrutinized the applicability of 32 distinct safety checklist items for drone operations. The primary aim of this investigation was to probe the possible deployment of drones as part of construction safety inspections at work sites. However, it bears mentioning that subsequent research should strive to gather a more extensive sample size through questionnaire surveys, thereby facilitating quantitative analysis. Administering such surveys would yield more comprehensive data compared to a focus group interview, which was constrained by a limited participant count. In summation, this study lays a foundational groundwork for understanding the potential advantages and challenges associated with integrating drones into construction safety management.

A Flight Mechanics-Centric Review of Bird-Scale Flapping Flight

  • Paranjape, Aditya A.;Dorothy, Michael R.;Chung, Soon-Jo;Lee, Ki-D.
    • International Journal of Aeronautical and Space Sciences
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    • v.13 no.3
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    • pp.267-281
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    • 2012
  • This paper reviews the flight mechanics and control of birds and bird-size aircraft. It is intended to fill a niche in the current survey literature which focuses primarily on the aerodynamics, flight dynamics and control of insect scale flight. We review the flight mechanics from first principles and summarize some recent results on the stability and control of birds and bird-scale aircraft. Birds spend a considerable portion of their flight in the gliding (i.e., non-flapping) phase. Therefore, we also review the stability and control of gliding flight, and particularly those aspects which are derived from the unique control features of birds.

An Overview of Flight Test Planning and Test Results for the Development of Korean Utility Helicopter (한국형 기동헬기 개발을 위한 비행시험 계획 및 시험결과 개요)

  • Kwon, Hyuk-Jun;Park, Jaeyoung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.3
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    • pp.268-276
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    • 2013
  • The objective of this paper is to give a general understanding for the development flight test of Korean Utility Helicopter(KUH). This paper contains the contents of detailed flight test plan, the type of flight test, an introduction to main flight test area, and the overview of flight test results. At the beginning, more than 8,500 test points were identified for airworthiness certification to show the compliance for the KUH development requirements. However, the number of flight test points were optimized to 7,800 at the end. To accomplish the test objectives, about 860 flight test sorties had been performed, and more than 1,000 test sorties were consumed for trouble shooting. This paper also describes some major issues faced during development flight test phase.

Flight Performance of a Dual One-Way Carrier Phase Ranging Instrument (이중단방향 반송파 거리측정기 비행성능 분석)

  • Kim, Jeong-Rae
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.17 no.1
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    • pp.52-57
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    • 2009
  • One of the error sources for microwave ranging is the instability of the oscillator that drives the microwave signals. Dual one-way ranging (DOWR) minimizes the oscillator effect by combining two one-way carrier phase signals from two transmitter/receiver instrument. The DOWR is first implemented in the GRACE (Gravity Recovery and Climate Experiment) satellites. Direct evaluation of the DOWR is not possible due to its extremely high accuracy. The flight performance of the GRACE DOWR is analyzed by applying several indirect methods. Comparison with the design noise level is discussed.

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